Efficacy and safety of catheter-based radiofrequency renal denervation in stented renal arteries.

Science.gov (United States)

Mahfoud, Felix; Tunev, Stefan; Ruwart, Jennifer; Schulz-Jander, Daniel; Cremers, Bodo; Linz, Dominik; Zeller, Thomas; Bhatt, Deepak L; Rocha-Singh, Krishna; Böhm, Michael; Melder, Robert J

2014-12-01

In selected patients with hypertension, renal artery (RA) stenting is used to treat significant atherosclerotic stenoses. However, blood pressure often remains uncontrolled after the procedure. Although catheter-based renal denervation (RDN) can reduce blood pressure in certain patients with resistant hypertension, there are no data on the feasibility and safety of RDN in stented RA. We report marked blood pressure reduction after RDN in a patient with resistant hypertension who underwent previous stenting. Subsequently, radiofrequency ablation was investigated within the stented segment of porcine RA, distal to the stented segment, and in nonstented RA and compared with stent only and untreated controls. There were neither observations of thrombus nor gross or histological changes in the kidneys. After radiofrequency ablation of the nonstented RA, sympathetic nerves innervating the kidney were significantly reduced, as indicated by significant decreases in sympathetic terminal axons and reduction of norepinephrine in renal tissue. Similar denervation efficacy was found when RDN was performed distal to a renal stent. In contrast, when radiofrequency ablation was performed within the stented segment of the RA, significant sympathetic nerve ablation was not seen. Histological observation showed favorable healing in all arteries. Radiofrequency ablation of previously stented RA demonstrated that RDN provides equally safe experimental procedural outcomes in a porcine model whether the radiofrequency treatment is delivered within, adjacent, or without the stent struts being present in the RA. However, efficacious RDN is only achieved when radiofrequency ablation is delivered to the nonstented RA segment distal to the stent. © 2014 American Heart Association, Inc.

Review of the State of Renal Nerve Ablation for Patients with Severe and Resistant Hypertension

Science.gov (United States)

Gulati, Vinay; White, William B.

2013-01-01

Through modulation of renin secretion, glomerular filtration rate and renal absorption of sodium, the sympathetic innervation of the kidneys plays an important role in the pathogenesis of hypertension. Renal nerve ablation technology is being developed for treatment of drug-treatment resistant hypertension worldwide. Preliminary research with the use of radiofrequency based renal denervation systems have demonstrated encouraging results with significant reduction of blood pressure in patients inadequately controlled despite nearly maximal drug therapy regimens. From work done thus far, the renal denervation procedure has not been associated with serious adverse effects. Long term efficacy and safety still needs to be established for renal nerve ablation. This review focuses on the impact of the renal sympathetic system on blood pressure regulation, the clinical rationale for renal nerve ablation in severe and drug-treatment resistant hypertension and current evidence from the more advanced renal denervation devices. PMID:23953998

Renal denervation beyond the bifurcation : The effect of distal ablation placement on safety and blood pressure

NARCIS (Netherlands)

Beeftink, Martine M A; Spiering, Wilko; De Jong, Mark R.; Doevendans, Pieter A.; Blankestijn, Peter J.; Elvan, Arif; Heeg, Jan Evert; Bots, Michiel L.; Voskuil, Michiel

2017-01-01

Renal denervation may be more effective if performed distal in the renal artery because of smaller distances between the lumen and perivascular nerves. The authors reviewed the angiographic results of 97 patients and compared blood pressure reduction in relation to the location of the denervation.

Device-based approaches for renal nerve ablation for hypertension and beyond

Directory of Open Access Journals (Sweden)

Alicia Ann Thorp

2015-07-01

Full Text Available Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy’s efficacy. Disrupting renal afferent sympathetic signalling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic over-activity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of–concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic over-activity is also presented.

Device-based approaches for renal nerve ablation for hypertension and beyond

Science.gov (United States)

Thorp, Alicia A.; Schlaich, Markus P.

2015-01-01

Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy's efficacy. Disrupting renal afferent sympathetic signaling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic overactivity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of-concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic overactivity is also presented. PMID:26217232

Device-based approaches for renal nerve ablation for hypertension and beyond.

Science.gov (United States)

Thorp, Alicia A; Schlaich, Markus P

2015-01-01

Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy's efficacy. Disrupting renal afferent sympathetic signaling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic overactivity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of-concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic overactivity is also presented.

Catheter-based renal denervation for resistant hypertension: 12-month results of the EnligHTN I first-in-human study using a multielectrode ablation system.

Science.gov (United States)

Papademetriou, Vasilios; Tsioufis, Costas P; Sinhal, Ajay; Chew, Derek P; Meredith, Ian T; Malaiapan, Yuvi; Worthley, Matthew I; Worthley, Stephen G

2014-09-01

Renal denervation has emerged as a novel approach for the treatment of patients with drug-resistant hypertension. To date, only limited data have been published using multielectrode radiofrequency ablation systems. In this article, we present the 12-month data of EnligHTN I, a first-in-human study using a multielectrode ablation catheter. EnligHTN I enrolled 46 patients (average age, 60±10 years; on average 4.7±1.0 medications) with drug-resistant hypertension. Eligible patients were on ≥3 antihypertensive medications and had a systolic blood pressure (BP) ≥160 mm Hg (≥150 mm Hg for diabetics). Bilateral renal artery ablation was performed using a percutaneous femoral approach and standardized techniques. The average baseline office BP was 176/96 mm Hg, average 24-hour ambulatory BP was 150/83 mm Hg, and average home BP was 158/90 mm Hg. The average reductions (mm Hg) at 1, 3, 6, and 12 months were as follows: office: -28/-10, -27/-10, -26/-10, and -27/-11 mm Hg (Prenal function and no new serious or life-threatening adverse events. One patient with baseline nonocclusive renal artery stenosis progressed to 75% diameter stenosis, requiring renal artery stenting. The 12-month data continue to demonstrate safety and efficacy of the EnligHTN ablation system in patients with drug-resistant hypertension. Home BP measurements parallel measurements obtained with 24-hour ambulatory monitoring. © 2014 American Heart Association, Inc.

Renal denervation and hypertension.

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Schlaich, Markus P; Krum, Henry; Sobotka, Paul A; Esler, Murray D

2011-06-01

Essential hypertension remains one of the biggest challenges in medicine with an enormous impact on both individual and society levels. With the exception of relatively rare monogenetic forms of hypertension, there is now general agreement that the condition is multifactorial in nature and hence requires therapeutic approaches targeting several aspects of the underlying pathophysiology. Accordingly, all major guidelines promote a combination of lifestyle interventions and combination pharmacotherapy to reach target blood pressure (BP) levels in order to reduce overall cardiovascular risk in affected patients. Although this approach works for many, it fails in a considerable number of patients for various reasons including drug-intolerance, noncompliance, physician inertia, and others, leaving them at unacceptably high cardiovascular risk. The quest for additional therapeutic approaches to safely and effectively manage hypertension continues and expands to the reappraisal of older concepts such as renal denervation. Based on the robust preclinical and clinical data surrounding the role of renal sympathetic nerves in various aspects of BP control very recent efforts have led to the development of a novel catheter-based approach using radiofrequency (RF) energy to selectively target and disrupt the renal nerves. The available evidence from the limited number of uncontrolled hypertensive patients in whom renal denervation has been performed are auspicious and indicate that the procedure has a favorable safety profile and is associated with a substantial and presumably sustained BP reduction. Although promising, a myriad of questions are far from being conclusively answered and require our concerted research efforts to explore the full potential and possible risks of this approach. Here we briefly review the science surrounding renal denervation, summarize the current data on safety and efficacy of renal nerve ablation, and discuss some of the open questions that need

Blood Pressure Response to Main Renal Artery and Combined Main Renal Artery Plus Branch Renal Denervation in Patients With Resistant Hypertension.

Science.gov (United States)

Fengler, Karl; Ewen, Sebastian; Höllriegel, Robert; Rommel, Karl-Philipp; Kulenthiran, Saaraaken; Lauder, Lucas; Cremers, Bodo; Schuler, Gerhard; Linke, Axel; Böhm, Michael; Mahfoud, Felix; Lurz, Philipp

2017-08-10

Single-electrode ablation of the main renal artery for renal sympathetic denervation showed mixed blood pressure (BP)-lowering effects. Further improvement of the technique seems crucial to optimize effectiveness of the procedure. Because sympathetic nerve fibers are closer to the lumen in the distal part of the renal artery, treatment of the distal main artery and its branches has been shown to reduce variability in treatment effects in preclinical studies and a recent randomized trial. Whether this optimized technique improves clinical outcomes remains uncertain. We report a 2-center experience of main renal artery and combined main renal artery plus branches renal denervation in patients with resistant hypertension using a multielectrode catheter. Twenty-five patients with therapy-resistant hypertension underwent renal sympathetic denervation with combined main renal artery and renal branch ablation and were compared to matched controls undergoing an ablation of the main renal artery only. BP change was assessed by ambulatory measurement at baseline and after 3 months. At baseline, BP was balanced between the groups. After 3 months, BP changed significantly in the combined ablation group (systolic/diastolic 24-hour mean and daytime mean BP -8.5±9.8/-7.0±10.7 and -9.4±9.8/-7.1±13.5 mm Hg, P renal artery and branches appears to improve BP-lowering efficacy and should be further investigated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Renal sympathetic denervation using an externally irrigated radiofrequency ablation catheter for treatment of resistant hypertension - Acute safety and short term efficacy.

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Yalagudri, Sachin; Raju, Narayana; Das, Bharati; Daware, Ashwin; Maiya, Shreesha; Jothiraj, Kannan; Ravikishore, A G

2015-01-01

This study was conducted to assess the acute safety and short term efficacy of renal sympathetic denervation (RSDN) using solid tip radiofrequency ablation (RFA) catheter and saline irrigation through the renal guiding catheter to achieve effective denervation. RSDN using a specialized solid-tip RFA catheter has recently been demonstrated to safely reduce systemic blood pressure in patients with refractory hypertension, the limitation being inadequate power delivery in renal arteries. So, we used solid-tip RFA catheter along with saline irrigation for RSDN. Nine patients with resistant hypertension underwent CT and conventional renal angiography, followed by bilateral or unilateral RSDN using 5F RFA catheter with saline irrigation through renal guiding catheter. Repeat renal angiography was performed at the end of the procedure. In all patients, pre- and post-procedure serum creatinine was measured. Over 1-month period: 1) the systolic/diastolic blood pressure decreased by -57 ± 20/-25 ± 7.5 mm Hg; 2) all patients experienced a decrease in systolic blood pressure of at least -36 mm Hg (range 36-98 mm Hg); 3) there was no evidence of renal artery injury immediate post-procedure. There was no significant change in serum creatinine level. This data shows the acute procedural safety and short term efficacy of RSDN using modified externally irrigated solid tip RFA catheter. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Rationale and design of a large registry on renal denervation: the Global SYMPLICITY registry.

Science.gov (United States)

Böhm, Michael; Mahfoud, Felix; Ukena, Christian; Bauer, Axel; Fleck, Eckart; Hoppe, Uta C; Kintscher, Ulrich; Narkiewicz, Krzysztof; Negoita, Manuela; Ruilope, Luis; Rump, L Christian; Schlaich, Markus; Schmieder, Roland; Sievert, Horst; Weil, Joachim; Williams, Bryan; Zeymer, Uwe; Mancia, Giuseppe

2013-08-22

Hypertension is a global healthcare concern associated with a wide range of comorbidities. The recognition that elevated sympathetic drive plays an important role in the pathogenesis of hypertension led to the use of renal artery denervation to interrupt the efferent and afferent sympathetic nerves between the brain and kidneys to lower blood pressure. Clinical trials of the Symplicity™ renal denervation system have demonstrated that radiofrequency ablation of renal artery nerves is safe and significantly lowers blood pressure in patients with severe resistant (systolic BP >160 mmHg) hypertension. Smaller ancillary studies in hypertensive patients suggest a benefit from renal denervation in a variety of conditions such as chronic kidney disease, glucose intolerance, sleep apnoea and heart failure. The Global SYMPLICITY registry, which incorporates the GREAT SYMPLICITY registry initiated in Germany, is being conducted worldwide to evaluate the safety and efficacy of treatment with the Symplicity renal denervation system in real-world uncontrolled hypertensive patients, looking first at subjects with severe resistant hypertension to confirm the results of prior clinical trials, but then also subjects with a wider range of baseline blood pressure and coexisting comorbidities. The rationale, design and first baseline data from the Global SYMPLICITY registry are presented.

MRI appearance of muscle denervation

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Kamath, S. [University Hospital of Wales, Department of Radiology, Cardiff (United Kingdom); Venkatanarasimha, N.; Walsh, M.A.; Hughes, P.M. [Derriford Hospital, Department of Radiology, Plymouth (United Kingdom)

2008-05-15

Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation. (orig.)

Afferent Neural Feedback Overrides the Modulating Effects of Arousal, Hypercapnia and Hypoxemia on Neonatal Cardio-respiratory Control.

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Lumb, Kathleen J; Schneider, Jennifer M; Ibrahim, Thowfique; Rigaux, Anita; Hasan, Shabih U

2018-04-20

Evidence at whole animal, organ-system, and cellular and molecular levels suggests that afferent volume feedback is critical for establishment of adequate ventilation at birth. Due to the irreversible nature of vagal ablation studies to date, it was difficult to quantify the roles of afferent volume input, arousal and changes in blood gas tensions on neonatal respiratory control. During reversible perineural vagal block, profound apneas, and hypoxemia and hypercarbia were observed necessitating termination of perineural blockade. Respiratory depression and apneas were independent of the sleep states. We demonstrate that profound apneas and life-threatening respiratory failure in vagally denervated animals do not result from lack of arousal or hypoxemia. Change in sleep state and concomitant respiratory depression result from lack of afferent volume feedback, which appears to be critical for the maintenance of normal breathing patterns and adequate gas exchange during the early postnatal period. Afferent volume feedback plays a vital role in neonatal respiratory control. Mechanisms for the profound respiratory depression and life-threatening apneas observed in vagally denervated neonatal animals remain unclear. We investigated the roles of sleep states, hypoxic-hypercapnia and afferent volume feedback on respiratory depression using reversible perineural vagal block during early postnatal period. Seven lambs were instrumented during the first 48h of life to record/analyze sleep states, diaphragmatic electromyograph, arterial blood gas tensions, systemic arterial blood pressure and rectal temperature. Perineural cuffs were placed around the vagi to attain reversible blockade. Post-operatively, during the awake state, both vagi were blocked using 2% xylocaine for up to 30 minutes. Compared with baseline values, pHa, PaO 2 and SaO 2 decreased and PaCO 2 increased during perineural blockade (P Respiratory depression and apneas were independent of sleep states. This

Joint UK societies’ 2014 consensus statement on renal denervation for resistant hypertension

Science.gov (United States)

Lobo, Melvin D; de Belder, Mark A; Cleveland, Trevor; Collier, David; Dasgupta, Indranil; Deanfield, John; Kapil, Vikas; Knight, Charles; Matson, Matthew; Moss, Jonathan; Paton, Julian F R; Poulter, Neil; Simpson, Iain; Williams, Bryan; Caulfield, Mark J

2015-01-01

Resistant hypertension continues to pose a major challenge to clinicians worldwide and has serious implications for patients who are at increased risk of cardiovascular morbidity and mortality with this diagnosis. Pharmacological therapy for resistant hypertension follows guidelines-based regimens although there is surprisingly scant evidence for beneficial outcomes using additional drug treatment after three antihypertensives have failed to achieve target blood pressure. Recently there has been considerable interest in the use of endoluminal renal denervation as an interventional technique to achieve renal nerve ablation and lower blood pressure. Although initial clinical trials of renal denervation in patients with resistant hypertension demonstrated encouraging office blood pressure reduction, a large randomised control trial (Symplicity HTN-3) with a sham-control limb, failed to meet its primary efficacy end point. The trial however was subject to a number of flaws which must be taken into consideration in interpreting the final results. Moreover a substantial body of evidence from non-randomised smaller trials does suggest that renal denervation may have an important role in the management of hypertension and other disease states characterised by overactivation of the sympathetic nervous system. The Joint UK Societies does not recommend the use of renal denervation for treatment of resistant hypertension in routine clinical practice but remains committed to supporting research activity in this field. A number of research strategies are identified and much that can be improved upon to ensure better design and conduct of future randomised studies. PMID:25431461

Effects of renal denervation with a standard irrigated cardiac ablation catheter on blood pressure and renal function in patients with chronic kidney disease and resistant hypertension.

Science.gov (United States)

Kiuchi, Márcio Galindo; Maia, George Luiz Marques; de Queiroz Carreira, Maria Angela Magalhães; Kiuchi, Tetsuaki; Chen, Shaojie; Andrea, Bruno Rustum; Graciano, Miguel Luis; Lugon, Jocemir Ronaldo

2013-07-01

Evaluation of the safety and efficacy of renal denervation with a standard irrigated cardiac ablation catheter (SICAC) in chronic kidney disease (CKD) patients with refractory hypertension. Twenty-four patients were included and treated with a SICAC. Denervation was performed by a single operator following the standard technique. Patients included with CKD were on stages 2 (n = 16), 3 (n = 4), and 4 (n = 4). Data were obtained at baseline and monthly until 180th day of follow-up. Baseline values of blood pressure (mean ± SD) were 186 ± 19 mmHg/108 ± 13 mmHg in the office, and 151 ± 18 mmHg/92 ± 11 mmHg by 24 h ambulatory blood pressure monitoring (ABPM). Office blood pressure values at 180th day after the procedure were 135 ± 13 mmHg/88 ± 7 mmHg (P < 0.0001, for both comparisons). The mean ABPM decreased to 132 ± 15 mmHg/85 ± 11 mmHg at the 180th day after the procedure (P < 0.0001 for systolic and P = 0.0015 for diastolic). Estimated glomerular filtration (mean ± SD) increased from baseline (64.4 ± 23.9 mL/min/1.73 m(2)) to the 180th day (85.4 ± 34.9 mL/min/1.73 m(2), P < 0.0001) of follow-up. The median urine albumin:creatinine ratio decreased from baseline (48.5, IQR: 35.8-157.2 mg/g) to the 180th day after ablation (ACR = 15.7, IQR: 10.3-34.2 mg/g, P = 0.0017). No major complications were seen. The procedure using SICAC seemed to be feasible, effective, and safe resulting in a better control of BP, a short-term increase in estimated glomerular filtration rate, and reduced albuminuria. Although encouraging, our data are preliminary and need to be validated in the long term.

Radiofrequency Catheter Ablation for Atrial Fibrillation Elicited "Jackhammer Esophagus": A New Complication Due to Vagal Nerve Stimulation?

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Tolone, Salvatore; Savarino, Edoardo; Docimo, Ludovico

2015-10-01

Radiofrequency catheter ablation (RFCA) is a potentially curative method for treatment of highly symptomatic and drug-refractory atrial fibrillation (AF). However, this technique can provoke esophageal and nerve lesion, due to thermal injury. To our knowledge, there have been no reported cases of a newly described motor disorder, the Jackhammer esophagus (JE) after RFCA, independently of GERD. We report a case of JE diagnosed by high-resolution manometry (HRM), in whom esophageal symptoms developed 2 weeks after RFCA, in absence of objective evidence of GERD. A 65-year-old male with highly symptomatic, drug-refractory paroxysmal AF was candidate to complete electrical pulmonary vein isolation with RFCA. Prior the procedure, the patient underwent HRM and impedance-pH to rule out GERD or hiatal hernia presence. All HRM parameters, according to Chicago classification, were within normal limits. No significant gastroesophageal reflux was documented at impedance pH monitoring. Patient underwent RFCA with electrical disconnection of pulmonary vein. After two weeks, patient started to complain of dysphagia for solids, with acute chest-pain. The patient repeated HRM and impedance-pH monitoring 8 weeks after RFCA. HRM showed in all liquid swallows the typical spastic hypercontractile contractions consistent with the diagnosis of JE, whereas impedance-pH monitoring resulted again negative for GERD. Esophageal dysmotility can represent a possible complication of RFCA for AF, probably due to a vagal nerve injury, and dysphagia appearance after this procedure must be timely investigated by HRM.

Controlled circumferential renal sympathetic denervation with preservation of the renal arterial wall using intraluminal ultrasound: a next-generation approach for treating sympathetic overactivity.

Science.gov (United States)

Sakakura, Kenichi; Roth, Austin; Ladich, Elena; Shen, Kai; Coleman, Leslie; Joner, Michael; Virmani, Renu

2015-02-01

The Paradise Ultrasound Renal Denervation System is a next-generation catheter-based device which was used to investigate whether the target ablation area can be controlled by changing ultrasound energy and duration to optimise nerve injury while preventing damage to the arterial wall. Five ultrasound doses were tested in a thermal gel model. Catheter-based ultrasound denervation was performed in 15 swine (29 renal arteries) to evaluate five different doses in vivo, and animals were euthanised at seven days for histopathologic assessment. In the gel model, the peak temperature was highest in the low power-long duration (LP-LD) dose, followed by the mid-low power-mid duration (MLP-MD) dose and the mid-high power-short duration (MHP-SD) dose, and lowest in the mid power-short duration (MP-SD) dose and the high power-ultra short duration (HP-USD) dose. In the animal study, total ablation area was significantly greater in the LP-LD group, followed by the MLP-MD group, and it was least in the HP-USD, MP-SD and MHP-SD groups (p=0.02). Maximum distance was significantly greater in the LP-LD group, followed by the MLP-MD group, the MHP-SD group, and the HP-USD group, and shortest in the MP-SD group (p=0.007). The short spare distance was not different among the five groups (p=0.38). Renal artery damage was minimal, while preserving significant nerve damage in all groups. The Paradise Ultrasound Renal Denervation System is a controllable system where total ablation area and depth of ablation can be optimised by changing ultrasound power and duration while sparing renal arterial tissue damage but allowing sufficient peri-arterial nerve damage.

Withdrawal and restoration of central vagal afferents within the dorsal vagal complex following subdiaphragmatic vagotomy.

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Peters, James H; Gallaher, Zachary R; Ryu, Vitaly; Czaja, Krzysztof

2013-10-15

Vagotomy, a severing of the peripheral axons of the vagus nerve, has been extensively utilized to determine the role of vagal afferents in viscerosensory signaling. Vagotomy is also an unavoidable component of some bariatric surgeries. Although it is known that peripheral axons of the vagus nerve degenerate and then regenerate to a limited extent following vagotomy, very little is known about the response of central vagal afferents in the dorsal vagal complex to this type of damage. We tested the hypothesis that vagotomy results in the transient withdrawal of central vagal afferent terminals from their primary central target, the nucleus of the solitary tract (NTS). Sprague-Dawley rats underwent bilateral subdiaphragmatic vagotomy and were sacrificed 10, 30, or 60 days later. Plastic changes in vagal afferent fibers and synapses were investigated at the morphological and functional levels by using a combination of an anterograde tracer, synapse-specific markers, and patch-clamp electrophysiology in horizontal brain sections. Morphological data revealed that numbers of vagal afferent fibers and synapses in the NTS were significantly reduced 10 days following vagotomy and were restored to control levels by 30 days and 60 days, respectively. Electrophysiology revealed transient decreases in spontaneous glutamate release, glutamate release probability, and the number of primary afferent inputs. Our results demonstrate that subdiaphragmatic vagotomy triggers transient withdrawal and remodeling of central vagal afferent terminals in the NTS. The observed vagotomy-induced plasticity within this key feeding center of the brain may be partially responsible for the response of bariatric patients following gastric bypass surgery. Copyright © 2013 Wiley Periodicals, Inc.

Is the failure of SYMPLICITY HTN-3 trial to meet its efficacy endpoint the "end of the road" for renal denervation?

Science.gov (United States)

Epstein, Murray; de Marchena, Eduardo

2015-02-01

Resistant hypertension is a common medical problem that is increasing with the advent of an increasingly older and heavier population. The etiology of resistant hypertension is almost always multifactorial, but the results of numerous studies indicate that renal sympathetic activation is a particularly common cause of resistance to antihypertensive treatment. Consistent with the belief in a pivotal role of renal sympathetic stimulation, there has been a growing interest in renal denervation (RDN) treatment strategies. The long-awaited results of SYMPLICITY HTN-3 study disclosed that the reduction in blood pressure by the SYMPLICITY device did not differ from that in the sham-procedure arm of the study. In the present article, we identify several factors that explain why the study failed to demonstrate any benefit from the intervention. The reasons are multifactorial and include inadequate screening at entry and frequent medication changes during the study. Additional problems include the lack of experience of many operators with the SYMPLICITY device and procedure variability, as attested to by a diminished number of ablation "quadrants." Also a factor was the inability of the first generation Medtronic device to allow four ablations to be performed simultaneously. We recommend that future RDN studies adhere to more rigorous screening procedures, and utilize newer multi-site denervation systems that facilitate four ablations simultaneously. Drug optimization should be achieved by monitoring adherence throughout the study. Nevertheless, we are optimistic about a future role of RDN. To optimize chances of success, increased efforts are necessary to identify the appropriate patients for RDN and investigators must use second and third generation denervation devices and techniques. Copyright © 2015 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Myenteric denervation differentially reduces enteroendocrine serotonin cell population in rats during postnatal development.

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Hernandes, Luzmarina; Fernandes, Marilda da Cruz; Pereira, Lucieni Cristina Marques da Silva; Freitas, Priscila de; Gama, Patrícia; Alvares, Eliana Parisi

2006-05-01

The enteric nervous and enteroendocrine systems regulate different processes in the small intestine. Ablation of myenteric plexus with benzalkonium chloride (BAC) stimulates epithelial cell proliferation, whereas endocrine serotonin cells may inhibit the process. To evaluate the connection between the systems and the influence of myenteric plexus on serotoninergic cells in rats during postnatal development, the ileal plexus was partially removed with BAC. Rats were treated at 13 or 21 days and sacrificed after 15 days. The cell bodies of myenteric neurons were stained by beta NADH-diaphorase to detect the extension of denervation. The number of enteroendocrine cells in the ileum was estimated in crypts and villi in paraffin sections immunostained for serotonin. The number of neurons was reduced by 27.6 and 45% in rats treated on the 13th and 21st days, respectively. We tried to establish a correlation of denervation and the serotonin population according to the age of treatment. We observed a reduction of immunolabelled cells in the crypts of rats treated at 13 days, whereas this effect was seen in the villi of rats denervated at 21 days. These results suggest that the enteric nervous system might control the enteroendocrine cell population and this complex mechanism could be correlated to changes in cell proliferation.

Renal denervation: Results of a single-center cohort study; Renale Denervation. Ergebnisse einer Single-Center Kohortenstudie

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Luetkens, J.A.; Thomas, D.; Doerner, J.; Schild, H.H.; Naehle, C.P. [Bonn Univ. (Germany). Dept. of Radiology; Wilhelm, K. [Johanniter Hospital, Bonn (Germany). Dept. of Radiology; Duesing, R. [Hypertension Center, Bonn (Germany); Woitas, R.P.; Hundt, F. [Bonn Univ. (Germany). Dept. of Internal Medicine I

2015-01-15

To investigate the effect of renal denervation on office-based and 24-h ambulatory blood pressure measurements (ABPM) in a highly selective patient population with drug-resistant hypertension. Patients with drug resistant hypertension eligible for renal denervation were included in the study population. Office blood pressure and ABPM were assessed prior to and after renal denervation. To detect procedure related renal or renal artery damage, magnetic resonance imaging (MRI) and angiography (MRA) were performed pre-interventional, one day post-interventional, and one month after renal denervation. Mean follow-up time between renal denervation and blood pressure re-assessment was 9.5 ± 3.9 months. Between August 2011 and March 2013, 17 patients prospectively underwent renal denervation. Pre-interventional mean office blood pressure and ABPM were 177.3 ± 20.3/103.8 ± 20.4 mmHg and 155.2 ± 20.5/93.7 ± 14.5 mmHg, respectively. Post-interventional, office blood pressure was significantly reduced to 144.7 ± 14.9/89.5 ± 12.1 (p < 0.05). ABPM values remained unchanged (147.9 ± 20.3/90.3 ± 15.6, p > 0.05). The number of prescribed antihypertensive drugs was unchanged after renal denervation (4.7 ± 2.0 vs. 4.2 ± 1.2, p = 0.18). No renovascular complications were detected in follow-up MRI. After renal denervation, no significant decrease in ABPM was observed. These results may indicate a limited impact of renal denervation for drug resistant hypertension.

Insulin action in denervated skeletal muscle

International Nuclear Information System (INIS)

Smith, R.L.

1987-01-01

The goal of this study was to determine the mechanisms responsible for reduced insulin response in denervated muscle. Denervation for 3 days of rat muscles consisting of very different compositions of fiber types decreased insulin stimulated [U- 14 C]glucose incorporation into glycogen by 80%. Associated with the reduction in glycogen synthesis was a decreased activation of glycogen synthase. Denervation of hemidiaphragms for 1 day decreased both the basal and insulin stimulated activity ratios of glycogen synthase and the rate of insulin stimulated [U- 14 C[glucose incorporation into glycogen by 50%. Insulin stimulation of 2-deoxy[ 3 H]glucose uptake was not decreased until 3 days after denervation. Consistent with the effects on glucose transport,insulin did not increase the intracellular concentration of glucose-6-P in muscles 3 days after denervation. Furthermore, since the Ka for glucose-6-P activation of glycogen synthase was not decreased by insulin in denervated hemidiaphragms, the effects of denervation on glycogen synthase and glucose transport were synergistic resulting in the 80% decrease in glycogen synthesis rates

Denervation of nerve terminals in renal arteries: one-year follow-up of interventional treatment of arterial hypertension.

Science.gov (United States)

Bartuś, Krzysztof; Sadowski, Jerzy; Kapelak, Bogusław; Litwinowicz, Radosław; Zajdel, Wojciech; Godlewski, Jacek; Bartuś, Magdalena; Zmudka, Krzysztof; Chrapusta, Anna; Konstanty-Kalandyk, Janusz; Węgrzyn, Piotr; Sobotka, Paul A

2014-01-01

Arterial hypertension is the most common cardiovascular system disease, affecting nearly one billion people worldwide. Despite the widespread use of antihypertensive medications, in some groups of patients an optimal blood pressure (BP) cannot be achieved. To assess BP reduction in patients with resistant hypertension after a catheter-based renal sympathetic denervation procedure and to report vascular and kidney safety in one-year follow-up. Twenty eight patients with diagnosed resistant hypertension (median age 52.02 years, range 42-72) underwent percutaneous catheter-based renal denervation of nerve terminals in renal arteries. Arterial angiography and procedure of ablation was performed by Symplicity catheters and generator provided by Ardian (currently Medtronic Inc., USA). Mean BP value before ablation was [mm Hg]: systolic 176.6, diastolic 100.28 and pulse pressure 73.4. After the procedure, reductions in the value of BP were reported [mm Hg]: systolic 154.8/152.54; diastolic 90.2/89.8, pulse pressure 64.66/62.73, respectively in nine-month and one-year follow-up. All results were statistically significant. No complications during one year observation were observed. Percutaneous renal artery ablation procedure effectively reduces systolic BP, diastolic BP, and pulse pressure. No vascular or renal complications in any of the patients were observed. The results of a Polish research group showed no significant differences compared to the results obtained in the international studies Symplicity I and Symplicity II.

Joint UK societies' 2014 consensus statement on renal denervation for resistant hypertension.

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Lobo, Melvin D; de Belder, Mark A; Cleveland, Trevor; Collier, David; Dasgupta, Indranil; Deanfield, John; Kapil, Vikas; Knight, Charles; Matson, Matthew; Moss, Jonathan; Paton, Julian F R; Poulter, Neil; Simpson, Iain; Williams, Bryan; Caulfield, Mark J

2015-01-01

Resistant hypertension continues to pose a major challenge to clinicians worldwide and has serious implications for patients who are at increased risk of cardiovascular morbidity and mortality with this diagnosis. Pharmacological therapy for resistant hypertension follows guidelines-based regimens although there is surprisingly scant evidence for beneficial outcomes using additional drug treatment after three antihypertensives have failed to achieve target blood pressure. Recently there has been considerable interest in the use of endoluminal renal denervation as an interventional technique to achieve renal nerve ablation and lower blood pressure. Although initial clinical trials of renal denervation in patients with resistant hypertension demonstrated encouraging office blood pressure reduction, a large randomised control trial (Symplicity HTN-3) with a sham-control limb, failed to meet its primary efficacy end point. The trial however was subject to a number of flaws which must be taken into consideration in interpreting the final results. Moreover a substantial body of evidence from non-randomised smaller trials does suggest that renal denervation may have an important role in the management of hypertension and other disease states characterised by overactivation of the sympathetic nervous system. The Joint UK Societies does not recommend the use of renal denervation for treatment of resistant hypertension in routine clinical practice but remains committed to supporting research activity in this field. A number of research strategies are identified and much that can be improved upon to ensure better design and conduct of future randomised studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Renal sympathetic denervation for treatment of resistant hypertension: Egyptian experience.

Science.gov (United States)

Hamza, Mohamed; Khamis, Hazem

2014-08-01

Among the Egyptian population with essential hypertension, a minority are under control (systolic pressure renal artery radiofrequency (RF) ablation. To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension in Egyptian patients. Patients with essential hypertension unresponsive to at least 3 types of antihypertensive medical therapy (baseline office systolic blood pressure ≥160 mmHg) (n = 55) were enrolled between February 2012 and June 2013 and received percutaneous RF ablation. Patients were followed up for 6 months after treatment to detect any change in office-based measurement of blood pressure. Urine and blood samples were taken to evaluate the effects on renal function. A reduction of mean office blood pressure was seen from 174/103 ± 9/5 mmHg at baseline to 150/91 ± 8/5 mmHg at 6 months follow-up (P = 0.001). Also, we noted a significant decrease in plasma renin activity (3.66 ± 0.64 vs. 3.37 ± 0.47 ng/mL per hour; P = 0.003), and there were no periprocedural complications, no adverse events, and no change in renal function during the follow-up period. Also, no change was noted in the number of medications after 6 months (3.95 ± 1.64 vs. 3.67 ± 0.72; P = 0.27). In this observational study, catheter-based renal denervation causes sustained blood pressure reduction in patients with resistant hypertension, without serious adverse events. © 2014, Wiley Periodicals, Inc.

Vagal tone during infant contingency learning and its disruption.

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Sullivan, Margaret Wolan

2016-04-01

This study used contingency learning to examine changes in infants' vagal tone during learning and its disruption. The heart rate of 160 five-month-old infants was recorded continuously during the first of two training sessions as they experienced an audiovisual event contingent on their pulling. Maternal reports of infant temperament were also collected. Baseline vagal tone, a measure of parasympathetic regulation of the heart, was related to vagal levels during the infants' contingency learning session, but not to their learner status. Vagal tone levels did not vary significantly over session minutes. Instead, vagal tone levels were a function of both individual differences in learner status and infant soothability. Vagal levels of infants who learned in the initial session were similar regardless of their soothability; however, vagal levels of infants who learned in a subsequent session differed as a function of soothability. Additionally, vagal levels during contingency disruption were significantly higher among infants in this group who were more soothable as opposed to those who were less soothable. The results suggest that contingency learning and disruption is associated with stable vagal tone in the majority of infants, but that individual differences in attention processes and state associated with vagal tone may be most readily observed during the disruption phase. © 2015 Wiley Periodicals, Inc.

Renal Denervation: a Field in Flux.

Science.gov (United States)

Laffin, Luke J; Bakris, George L

2016-07-01

SYMPLICITY HTN-3 was a pivotal moment for renal denervation as a treatment option for resistant hypertension. Prior unblinded studies were called into question given the negative results of the first sham-controlled trial of renal denervation. Reevaluation of the renal denervation procedure demonstrated that a more precise approach was needed to adequately denervate the kidney. This new approach has been implemented in two ongoing clinical trials, one on and one off medications to assess the new procedure's efficacy and safety. These and other ongoing trials will be discussed in the context of older studies in this field. We focus on novel findings published following the release of SYMPLICITY HTN-3 data in early 2014 and look to the future of renal denervation in the treatment of primary hypertension.

Catheter-based renal denervation for resistant hypertension: Twenty-four month results of the EnligHTN I first-in-human study using a multi-electrode ablation system.

Science.gov (United States)

Tsioufis, Costas P; Papademetriou, Vasilios; Dimitriadis, Kyriakos S; Kasiakogias, Alexandros; Tsiachris, Dimitrios; Worthley, Matthew I; Sinhal, Ajay R; Chew, Derek P; Meredith, Ian T; Malaiapan, Yuvi; Thomopoulos, Costas; Kallikazaros, Ioannis; Tousoulis, Dimitrios; Worthley, Stephen G

2015-12-15

Long term safety and efficacy data of multi-electrode ablation system for renal denervation (RDN) in patients with drug resistant hypertension (dRHT) are limited. We studied 46 patients (age: 60 ± 10 years, 4.7 ± 1.0 antihypertensive drugs) with drug resistant hypertension (dRHT). Reduction in office BP at 24 months from baseline was -29/-13 mmHg, while the reduction in 24-hour ambulatory BP and in home BP at 24 months were -13/-7 mmHg and -11/-6 mmHg respectively (p<0.05 for all). A correlation analysis revealed that baseline office and ambulatory BP were related to the extent of office and ambulatory BP drop. Apart from higher body mass index (33.3 ± 4.7 vs 29.5 ± 6.2 kg/m(2), p<0.05), there were no differences in patients that were RDN responders defined as ≥10 mmHg decrease (74%, n=34) compared to non-responders. Stepwise logistic regression analysis revealed no prognosticators of RDN response (p=NS for all). At 24 months there were no new serious device or procedure related adverse events. The EnligHTN I study shows that the multi-electrode ablation system provides a safe method of RDN in dRHT accompanied by a clinically relevant and sustained BP reduction. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Catheter based radiofrequency ablation of renal nerves for the treatment of resistant hypertension

Directory of Open Access Journals (Sweden)

Markus P. Schlaich

2013-03-01

Full Text Available Introduction Resistant hypertension is a common and growing clinical problem characterized by the failure to attain target blood pressure levels despite adequate use of at least three antihypertensive agents. Objectives The aim of this article is to emphasize the role of novel approaches to treat resistant hypertension. Materials and methods After an excursus on the physiological role of renal nerves on kidney function, volume homeostasis and blood pressure control, this article describes the radiofrequency ablation technology to obtain kidneys denervation. Results Activation of the sympathetic nervous system plays a prominent role as a major regulator of circulatory and metabolic control. The kidneys have a particularly dense afferent sensory and efferent sympathetic innervation and are thereby strategically positioned to be origin as well as target of sympathetic activation. In this context, recent evidence suggests that a novel catheter-based approach to functionally denervate the human kidneys using radiofrequency ablation technology may provide a safe and effective treatment alternative for resistant hypertension and its adverse consequences. Conclusions Despite the availability of numerous safe and effective pharmacological therapies to treat elevated blood pressure, novel therapeutic approaches are warranted to improve the management and prognosis of patients with refractory hypertension. Several clinical trials are currently conducted and planned to further substantiate the blood pressure lowering efficacy of this novel renal denervation procedure.

Imaging of denervation in the head and neck

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Borges, Alexandra [Radiology Department, Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Rua Prof. Lima Basto, 1093 Lisboa (Portugal)], E-mail: borgalexandra@gmail.com

2010-05-15

Denervation changes maybe the first sign of a cranial nerve injury. Recognition of denervation patterns can be used to determine the site and extent of a lesion and to tailor imaging studies according to the most likely location of an insult along the course of the affected cranial nerve(s). In addition, the extent of denervation can be used to predict functional recovery after treatment. On imaging, signs of denervation can be misleading as they often mimic recurrent neoplasm or inflammatory conditions. Imaging can both depict denervation related changes and establish its cause. This article briefly reviews the anatomy of the extracranial course of motor cranial nerves with particular emphasis on the muscles supplied by each nerve, the imaging features of the various stages of denervation, the different patterns of denervation that maybe helpful in the topographic diagnosis of nerve lesions and the most common causes of cranial nerve injuries leading to denervation.

Imaging of denervation in the head and neck.

Science.gov (United States)

Borges, Alexandra

2010-05-01

Denervation changes maybe the first sign of a cranial nerve injury. Recognition of denervation patterns can be used to determine the site and extent of a lesion and to tailor imaging studies according to the most likely location of an insult along the course of the affected cranial nerve(s). In addition, the extent of denervation can be used to predict functional recovery after treatment. On imaging, signs of denervation can be misleading as they often mimic recurrent neoplasm or inflammatory conditions. Imaging can both depict denervation related changes and establish its cause. This article briefly reviews the anatomy of the extracranial course of motor cranial nerves with particular emphasis on the muscles supplied by each nerve, the imaging features of the various stages of denervation, the different patterns of denervation that maybe helpful in the topographic diagnosis of nerve lesions and the most common causes of cranial nerve injuries leading to denervation. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Imaging of denervation in the head and neck

International Nuclear Information System (INIS)

Borges, Alexandra

2010-01-01

Denervation changes maybe the first sign of a cranial nerve injury. Recognition of denervation patterns can be used to determine the site and extent of a lesion and to tailor imaging studies according to the most likely location of an insult along the course of the affected cranial nerve(s). In addition, the extent of denervation can be used to predict functional recovery after treatment. On imaging, signs of denervation can be misleading as they often mimic recurrent neoplasm or inflammatory conditions. Imaging can both depict denervation related changes and establish its cause. This article briefly reviews the anatomy of the extracranial course of motor cranial nerves with particular emphasis on the muscles supplied by each nerve, the imaging features of the various stages of denervation, the different patterns of denervation that maybe helpful in the topographic diagnosis of nerve lesions and the most common causes of cranial nerve injuries leading to denervation.

Vagal stimulation in heart failure.

Science.gov (United States)

De Ferrari, Gaetano M

2014-04-01

Heart failure (HF) is accompanied by an autonomic imbalance that is almost always characterized by both increased sympathetic activity and withdrawal of vagal activity. Experimentally, vagal stimulation has been shown to exert profound antiarrhythmic activity and to improve cardiac function and survival in HF models. A open-label pilot clinical study in 32 patients with chronic HF has shown safety and tolerability of chronic vagal stimulation associated with subjective (improved quality of life and 6-min walk test) and objective improvements (reduced left ventricular systolic volumes and improved left ventricular ejection fraction). Three larger clinical studies, including a phase III trial are currently ongoing and will evaluate the clinical role of this new approach.

Reinnervation following catheter-based radio-frequency renal denervation.

Science.gov (United States)

Booth, Lindsea C; Nishi, Erika E; Yao, Song T; Ramchandra, Rohit; Lambert, Gavin W; Schlaich, Markus P; May, Clive N

2015-04-20

What is the topic of this review? Does catheter-based renal denervation effectively denervate the afferent and efferent renal nerves and does reinnervation occur? What advances does it highlight? Following catheter-based renal denervation, the afferent and efferent responses to electrical stimulation were abolished, renal sympathetic nerve activity was absent, and levels of renal noradrenaline and immunohistochemistry for tyrosine hydroxylase and calcitonin gene-related peptide were significantly reduced. By 11 months after renal denervation, both the functional responses and anatomical markers of afferent and efferent renal nerves had returned to normal, indicating reinnervation. Renal denervation reduces blood pressure in animals with experimental hypertension and, recently, catheter-based renal denervation was shown to cause a prolonged decrease in blood pressure in patients with resistant hypertension. The randomized, sham-controlled Symplicity HTN-3 trial failed to meet its primary efficacy end-point, but there is evidence that renal denervation was incomplete in many patients. Currently, there is little information regarding the effectiveness of catheter-based renal denervation and the extent of reinnervation. We assessed the effectiveness of renal nerve denervation with the Symplicity Flex catheter and the functional and anatomical reinnervation at 5.5 and 11 months postdenervation. In anaesthetized, non-denervated sheep, there was a high level of renal sympathetic nerve activity, and electrical stimulation of the renal nerve increased blood pressure and reduced heart rate (afferent response) and caused renal vasoconstriction and reduced renal blood flow (efferent response). Immediately after renal denervation, renal sympathetic nerve activity and the responses to electrical stimulation were absent, indicating effective denervation. By 11 months after denervation, renal sympathetic nerve activity was present and the responses to electrical stimulation

Police work stressors and cardiac vagal control.

Science.gov (United States)

Andrew, Michael E; Violanti, John M; Gu, Ja K; Fekedulegn, Desta; Li, Shengqiao; Hartley, Tara A; Charles, Luenda E; Mnatsakanova, Anna; Miller, Diane B; Burchfiel, Cecil M

2017-09-10

This study examines relationships between the frequency and intensity of police work stressors and cardiac vagal control, estimated using the high frequency component of heart rate variability (HRV). This is a cross-sectional study of 360 officers from the Buffalo New York Police Department. Police stress was measured using the Spielberger police stress survey, which includes exposure indices created as the product of the self-evaluation of how stressful certain events were and the self-reported frequency with which they occurred. Vagal control was estimated using the high frequency component of resting HRV calculated in units of milliseconds squared and reported in natural log scale. Associations between police work stressors and vagal control were examined using linear regression for significance testing and analysis of covariance for descriptive purposes, stratified by gender, and adjusted for age and race/ethnicity. There were no significant associations between police work stressor exposure indices and vagal control among men. Among women, the inverse associations between the lack of support stressor exposure and vagal control were statistically significant in adjusted models for indices of exposure over the past year (lowest stressor quartile: M = 5.57, 95% CI 5.07 to 6.08, and highest stressor quartile: M = 5.02, 95% CI 4.54 to 5.51, test of association from continuous linear regression of vagal control on lack of support stressor β = -0.273, P = .04). This study supports an inverse association between lack of organizational support and vagal control among female but not male police officers. © 2017 Wiley Periodicals, Inc.

[Jejunal myenteric denervation induced by benzalkonium chloride].

Science.gov (United States)

Ramalho, F S; Santos, G C; Ramalho, L N; Kajiwara, J K; Zucoloto, S

1994-01-01

The effects of benzalkonium chloride (BAC) on the number of myenteric neurons, muscle thickness and external perimeter after acute (until 10 days after BAC application) and chronic (30 and 60 days after BAC application) denervation of the proximal jejunum were determined in rats. There was a significant reduction in the number of myenteric neurons of all segments treated with BAC. The extent of denervation varied along the time, and it was reduced in the denervated segments of the chronic group in comparison with the acute group. This may be due to the neuroplasticity phenomenon appearing during the chronic phase. Myenteric denervation increased the thickness of the propria muscle layer, especially in the longitudinal muscle layer, suggesting a higher sensitivity of this layer to myenteric denervation.

Renal denervation: unde venis et quo vadis?

Science.gov (United States)

Nähle, C P; Düsing, R; Schild, H

2015-04-01

Renal denervation is a minimally invasive, catheter-based option for the treatment of refractory hypertension. Indications and contraindications for renal denervation have been defined in an interdisciplinary manner. The efficacy and safety of the procedure were evaluated. Currently, indication for renal denervation is limited to patients with primary hypertension and a systolic blood pressure of ≥ 160 mm Hg (or ≥ 150 mm Hg in diabetes type 2) despite optimal medical therapy with ≥ 3 different antihypertensive drugs. In this specific patient population, an average blood pressure reduction of 32/14 mmHg was observed in non-randomized/-controlled trials after renal denervation. These results were not confirmed in the first randomized controlled trial with a non-significantly superior blood pressure reduction of 14.1 ± 23.9 mm Hg compared to controls (-11.74 ± 25.94 mm Hg, difference -2.39 mm Hg p = 0.26 for superiority with a margin of 5 mm Hg) who underwent a sham procedure. The efficacy and long-term effects of renal denervation need to be re-evaluated in light of the HTN3 study results. To date, renal denervation should not be performed outside of clinical trials. Future trials should also assess if renal denervation can be performed with sufficient safety and efficacy in patients with hypertension-associated diseases. The use of renal denervation as an alternative therapy (e. g. in patients with drug intolerance) can currently not be advocated. The indication for renal denervation should be assessed in an interdisciplinary fashion and according to current guidelines with a special focus on ruling out secondary causes for arterial hypertension. 5 - 10 % of patients with hypertension suffer from refractory hypertension, but only about 1 % of patients meet the criteria for a renal denervation. Renal denervation leads to a significant decrease in office blood pressure; however, the impact on 24-hour blood pressure

Transcatheter Alcohol-Mediated Perivascular Renal Denervation With the Peregrine System: First-in-Human Experience.

Science.gov (United States)

Fischell, Tim A; Ebner, Adrian; Gallo, Santiago; Ikeno, Fumiaki; Minarsch, Laura; Vega, Félix; Haratani, Nicole; Ghazarossian, Vartan E

2016-03-28

This study evaluated the first clinical use of a new endovascular approach to renal denervation, using chemical neurolysis, via periadventitial infusion of dehydrated alcohol (ethanol) to perform "perivascular" renal artery sympathetic denervation. Renal denervation remains a promising technology for the treatment of hypertension and other disorders. A novel 3-needle delivery device (Peregrine System Infusion Catheter, Ablative Solutions, Inc., Kalamazoo, Michigan) was introduced into the renal arteries of 18 subjects with refractory hypertension. Microdoses of alcohol were infused bilaterally via the 3 needles into to the adventitial space (0.30 ml/artery, 37 arteries). Renal artery angiography was performed at the time of the procedure and at 6 months (n = 16). The primary safety endpoints were complications associated with the catheter insertion and delivery of the neurolytic agent or any major vascular access complications. The secondary performance endpoint was a reduction in office-based systolic blood pressure at 6 months compared with baseline. Procedural success was achieved in 100% of subjects (N = 18) and arteries (N = 37). There were no study-related adverse clinical events at follow-up. One death of a subject was recorded but determined by the investigator and an independent medical monitor to be non-study related. There were no angiographic observations of renal artery stenosis, aneurysms, or other renal artery abnormalities at 6 months (32 renal arteries). Sixteen of the 18 subjects had a 6-month follow-up. The mean office systolic blood pressure decreased from 175 ± 17 mm Hg to 151 ± 26 mm Hg (-24 mm Hg). There was an average reduction of antihypertensive medications from 3.4 (baseline) to 2.0 per subject at 6 months. Chemical renal denervation using the infusion of very low doses of alcohol directly into the adventitial space appears to be feasible and safe. This approach may be a promising alternative approach to perform catheter-based renal

Moderate Baseline Vagal Tone Predicts Greater Prosociality in Children

Science.gov (United States)

Miller, Jonas G.; Kahle, Sarah; Hastings, Paul D.

2016-01-01

Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children’s baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic association (inverted U-shape curve) between baseline vagal tone and prosociality (Kogan et al., 2014). The present research examined whether this nonlinear association was evident in children. We found consistent evidence for a quadratic relation between vagal tone and prosociality across 3 samples of children using 6 different measures. Compared to low and high vagal tone, moderate vagal tone in early childhood concurrently predicted greater self-reported prosociality (Study 1), observed empathic concern in response to the distress of others and greater generosity toward less fortunate peers (Study 2), and longitudinally predicted greater self-, mother-, and teacher-reported prosociality 5.5 years later in middle childhood (Study 3). Taken together, our findings suggest that moderate vagal tone at rest represents a physiological preparedness or tendency to engage in different forms of prosociality across different contexts. Early moderate vagal tone may reflect an optimal balance of regulation and arousal that helps prepare children to sympathize, comfort, and share with others. PMID:27819463

Chemical renal denervation in the rat.

Science.gov (United States)

Consigny, Paul M; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, Deanne

2014-02-01

The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose-response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography-mass spectrometry. Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10(-5) M through 10(-2) M paclitaxel. We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

Renal denervation therapy for the treatment of resistant hypertension: a position statement by the Canadian Hypertension Education Program.

Science.gov (United States)

Khan, Nadia A; Herman, Robert J; Quinn, Robert R; Rabkin, Simon W; Ravani, Pietro; Tobe, Sheldon W; Feldman, Ross D; Wijeysundera, Harindra C; Padwal, Raj S

2014-01-01

Renal denervation is a novel catheter-based, percutaneous procedure using radiofrequency energy to ablate nerves within the renal arteries. This procedure might help to significantly lower blood pressure (BP) in patients with resistant hypertension, defined as BP > 140/90 mm Hg (> 130/80 mm Hg for those with diabetes) despite use of ≥ 3 optimally dosed antihypertensive agents, ideally including 1 diuretic agent. The Canadian Hypertension Education Program Recommendations Task Force reviewed the current evidence on safety and efficacy of this procedure. Eleven studies on renal denervation were examined and most of the evidence evaluating renal denervation was derived from the Symplicity studies. In patients with systolic BP ≥ 160 mm Hg (≥ 150 mm Hg for patients with type 2 diabetes) despite use of ≥ 3 antihypertensive agents, bilateral renal denervation was associated with significantly lower BP (-22/11 to -34/13 mm Hg) at 6 months with a low periprocedural complication rate. Few patients underwent 24-hour ambulatory BP monitoring and ambulatory BP monitoring showed more modest BP lowering (0 to -11/7 mm Hg). Although early results on short-term safety and blood pressure-lowering are encouraging, there are no long-term efficacy and safety data, or hard cardiovascular end point data. The discrepancy between office BP reductions and 24-hour ambulatory BP monitor reductions needs to be further investigated. Until more data are available, renal sympathetic denervation should be considered as a treatment option of last resort for patients with resistant hypertension who have exhausted all other available medical management options. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Eligibility for renal denervation

DEFF Research Database (Denmark)

Persu, Alexandre; Jin, Yu; Baelen, Marie

2014-01-01

-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according...... undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility...... (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered....

Twelve-month results of the rapid renal sympathetic denervation for resistant hypertension using the OneShotTM ablation system (RAPID) study.

Science.gov (United States)

Verheye, Stefan; Ormiston, John; Bergmann, Martin W; Sievert, Horst; Schwindt, Arne; Werner, Nikos; Vogel, Britta; Colombo, Antonio

2015-02-01

Renal denervation has emerged as a treatment option for patients with drug-resistant hypertension. This study was designed to assess the safety and effectiveness of the OneShotª Renal Denervation System. RAPID is a prospective, multicentre, single-arm study which enrolled 50 patients at 11 clinical sites in Europe and New Zealand. Eligible patients had an office systolic blood pressure (SBP) ≥160 mmHg and were on a stable regimen of ≥3 antihypertensive medications including a diuretic. The primary safety endpoints were acute procedural safety at discharge and chronic procedural safety at six months. The primary effectiveness endpoint was the rate of office SBP reduction ≥10 mmHg at six months compared to baseline. While not a predefined endpoint, change in 24-hour ambulatory BP was evaluated. The mean baseline office SBP and diastolic BP measurements were 181.6±20.8 and 95.5±15.5 mmHg, respectively. Patients were on a mean of 5.1 antihypertensive medications at baseline. The mean office BP decreased by -20/-8 mmHg (prenal artery injury or SAE/adverse device effects at six months. The results of the RAPID study demonstrate safe delivery of RF energy by the OneShot Renal Denervation System for renal sympathetic denervation and sustained efficacy, as evidenced by a significant reduction in office and 24-hour ABPM for six months, which was sustained up to 12 months. ClinicalTrials.gov Identifier: NCT01520506.

Chemical Renal Denervation in the Rat

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Consigny, Paul M., E-mail: paul.consigny@av.abbott.com; Davalian, Dariush, E-mail: dariush.davalian@av.abbott.com [Abbott Vascular, Innovation Incubator (United States); Donn, Rosy, E-mail: rosy.donn@av.abbott.com; Hu, Jie, E-mail: jie.hu@av.abbott.com [Abbott Vascular, Bioanalytical and Material Characterization (United States); Rieser, Matthew, E-mail: matthew.j.rieser@abbvie.com; Stolarik, DeAnne, E-mail: deanne.f.stolarik@abbvie.com [Abbvie, Analytical Pharmacology (United States)

2013-12-03

Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10{sup −5} M through 10{sup −2} M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

Chemical Renal Denervation in the Rat

International Nuclear Information System (INIS)

Consigny, Paul M.; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, DeAnne

2014-01-01

Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10 −5  M through 10 −2  M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel

Perivascular radiofrequency renal denervation lowers blood pressure and ameliorates cardiorenal fibrosis in spontaneously hypertensive rats

Science.gov (United States)

Zhang, Yan; Su, Linan; Zhang, Yunrong; Wang, Qiang; Yang, Dachun; Li, De; Yang, Yongjian; Ma, Shuangtao

2017-01-01

Background Catheter-based renal denervation (RDN) is a promising approach to treat hypertension, but innervation patterns limit the response to endovascular RDN and the post-procedural renal artery narrowing or stenosis questions the endovascular ablation strategy. This study was performed to investigate the anti-hypertensive and target organ protective effects of perivascular RDN in spontaneously hypertensive rats (SHR). Methods SHR and normotensive Wistar-Kyoto (WKY) rats were divided into sham group (n = 10), radiofrequency ablation group (n = 20) in which rats received bilateral perivascular ablation with radiofrequency energy (2 watts), and chemical (10% phenol in 95% ethanol) ablation group (n = 12). The tail-cuff blood pressure was measured before the ablation and on day 14 and day 28 after the procedure. The plasma levels of creatinine, urea nitrogen, and catecholamines, urinary excretion of electrolytes and protein, and myocardial and glomerular fibrosis were analyzed and compared among the groups on day 28 after the procedure. Results We identified that 2-watt is the optimal radiofrequency power for perivascular RDN in rats. Perivascular radiofrequency and chemical ablation achieved roughly comparable blood pressure reduction in SHR but not in WKY on day 14 and day 28 following the procedure. Radiofrequency-mediated ablation substantially destroyed the renal nerves surrounding the renal arteries of both SHR and WKY without damaging the renal arteries and diminished the expression of tyrosine hydroxylase, the enzyme marker for postganglionic sympathetic nerves. Additionally, perivascular radiofrequency ablation also decreased the plasma catecholamines of SHR. Interestingly, both radiofrequency and chemical ablation decreased the myocardial and glomerular fibrosis of SHR, while neither increased the plasma creatinine and blood urea nitrogen nor affected the urinary excretion of electrolytes and protein when compared to sham group. Conclusions Radiofrequency

Safety and performance of the second generation EnligHTN™ Renal Denervation System in patients with drug-resistant, uncontrolled hypertension.

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Worthley, Stephen G; Wilkins, Gerard T; Webster, Mark W; Montarello, Joseph K; Delacroix, Sinny; Whitbourn, Robert J; Warren, Roderic J

2017-07-01

Catheter-based renal denervation for the treatment of drug-resistant hypertension has been intensively investigated in recent years. To date, only limited data have been published using multi-electrode radiofrequency ablation systems that can deliver lesions with a pre-determined pattern. This study was designed to evaluate the safety and performance of the second generation EnligHTN™ Renal Denervation System. This first-in-human, prospective, multi-center, non-randomized study included 39 patients (62% male, mean age 63 years, and mean baseline office blood pressure 174/93 mmHg) with drug-resistant hypertension. The primary safety and performance objectives were to characterize, from baseline to 6 months post procedure, the rate of serious procedural and device related adverse events, as adjudicated by an independent Clinical Events Committee, and the reduction of office systolic blood pressure. Renal artery denervation, using the second generation EnligHTN multi-electrode system significantly reduced office blood pressure from baseline to 1, 3, 6, 12, 18 and 24 months by 19/7, 26/9, 25/7, 23/7, 25/8 and 27/9 mmHg, respectively (p ≤ 0.0005). No serious device or procedure related adverse events affecting the renal arteries or renal function occurred through 24 months of follow-up. Renal sympathetic denervation using the second generation EnligHTN Renal Denervation System resulted in safe, rapid, and significant mean office blood pressure reduction that was sustained through 24 months. Future studies will need to address the utility of this system against an appropriate sham based comparator. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Device-based approaches for renal nerve ablation for hypertension and beyond

OpenAIRE

Alicia Ann Thorp; Markus Peter Schlaich; Markus Peter Schlaich

2015-01-01

Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy...

RENAL DENERVATION IN RESISTANT ARTERIAL HYPERTENSION

OpenAIRE

V. A. Sulimov; A. V. Rodionov; A. A. Svetankova; I. E. Deneka

2015-01-01

A new method of non-drug treatment of resistant hypertension – renal denervation is considered. General information about resistant hypertension, method of renal denervation, the results of clinical studies on efficacy and safety, as well as own clinical case are presented.

Twenty-Four-Hour Blood Pressure Monitoring to Predict and Assess Impact of Renal Denervation: The DENERHTN Study (Renal Denervation for Hypertension).

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Gosse, Philippe; Cremer, Antoine; Pereira, Helena; Bobrie, Guillaume; Chatellier, Gilles; Chamontin, Bernard; Courand, Pierre-Yves; Delsart, Pascal; Denolle, Thierry; Dourmap, Caroline; Ferrari, Emile; Girerd, Xavier; Michel Halimi, Jean; Herpin, Daniel; Lantelme, Pierre; Monge, Matthieu; Mounier-Vehier, Claire; Mourad, Jean-Jacques; Ormezzano, Olivier; Ribstein, Jean; Rossignol, Patrick; Sapoval, Marc; Vaïsse, Bernard; Zannad, Faiez; Azizi, Michel

2017-03-01

The DENERHTN trial (Renal Denervation for Hypertension) confirmed the blood pressure (BP) lowering efficacy of renal denervation added to a standardized stepped-care antihypertensive treatment for resistant hypertension at 6 months. We report here the effect of denervation on 24-hour BP and its variability and look for parameters that predicted the BP response. Patients with resistant hypertension were randomly assigned to denervation plus stepped-care treatment or treatment alone (control). Average and standard deviation of 24-hour, daytime, and nighttime BP and the smoothness index were calculated on recordings performed at randomization and 6 months. Responders were defined as a 6-month 24-hour systolic BP reduction ≥20 mm Hg. Analyses were performed on the per-protocol population. The significantly greater BP reduction in the denervation group was associated with a higher smoothness index ( P =0.02). Variability of 24-hour, daytime, and nighttime BP did not change significantly from baseline to 6 months in both groups. The number of responders was greater in the denervation (20/44, 44.5%) than in the control group (11/53, 20.8%; P =0.01). In the discriminant analysis, baseline average nighttime systolic BP and standard deviation were significant predictors of the systolic BP response in the denervation group only, allowing adequate responder classification of 70% of the patients. Our results show that denervation lowers ambulatory BP homogeneously over 24 hours in patients with resistant hypertension and suggest that nighttime systolic BP and variability are predictors of the BP response to denervation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01570777. © 2017 American Heart Association, Inc.

RENAL DENERVATION IN RESISTANT ARTERIAL HYPERTENSION

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V. A. Sulimov

2013-01-01

Full Text Available A new method of non-drug treatment of resistant hypertension – renal denervation is considered. General information about resistant hypertension, method of renal denervation, the results of clinical studies on efficacy and safety, as well as own clinical case are presented.

RENAL DENERVATION IN RESISTANT ARTERIAL HYPERTENSION

Directory of Open Access Journals (Sweden)

V. A. Sulimov

2015-09-01

Full Text Available A new method of non-drug treatment of resistant hypertension – renal denervation is considered. General information about resistant hypertension, method of renal denervation, the results of clinical studies on efficacy and safety, as well as own clinical case are presented.

Renal denervation: Results of a single-center cohort study

International Nuclear Information System (INIS)

Luetkens, J.A.; Thomas, D.; Doerner, J.; Schild, H.H.; Naehle, C.P.; Woitas, R.P.; Hundt, F.

2015-01-01

To investigate the effect of renal denervation on office-based and 24-h ambulatory blood pressure measurements (ABPM) in a highly selective patient population with drug-resistant hypertension. Patients with drug resistant hypertension eligible for renal denervation were included in the study population. Office blood pressure and ABPM were assessed prior to and after renal denervation. To detect procedure related renal or renal artery damage, magnetic resonance imaging (MRI) and angiography (MRA) were performed pre-interventional, one day post-interventional, and one month after renal denervation. Mean follow-up time between renal denervation and blood pressure re-assessment was 9.5 ± 3.9 months. Between August 2011 and March 2013, 17 patients prospectively underwent renal denervation. Pre-interventional mean office blood pressure and ABPM were 177.3 ± 20.3/103.8 ± 20.4 mmHg and 155.2 ± 20.5/93.7 ± 14.5 mmHg, respectively. Post-interventional, office blood pressure was significantly reduced to 144.7 ± 14.9/89.5 ± 12.1 (p 0.05). The number of prescribed antihypertensive drugs was unchanged after renal denervation (4.7 ± 2.0 vs. 4.2 ± 1.2, p = 0.18). No renovascular complications were detected in follow-up MRI. After renal denervation, no significant decrease in ABPM was observed. These results may indicate a limited impact of renal denervation for drug resistant hypertension.

Feasibility of catheter ablation renal denervation in "mild" resistant hypertension.

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Chen, Shaojie; Kiuchi, Marcio Galindo; Acou, Willem-Jan; Derndorfer, Michael; Wang, Jiazhi; Li, Ruotian; Kollias, Georgios; Martinek, Martin; Kiuchi, Tetsuaki; Pürerfellner, Helmut; Liu, Shaowen

2017-04-01

Renal denervation (RDN) has been proposed as a novel interventional antihypertensive technique. However, existing evidence was mainly from patients with severe resistant hypertension. The authors aimed to evaluate the efficacy of RDN in patients with resistant hypertension with mildly elevated blood pressure (BP). Studies of RDN in patients with mild resistant hypertension (systolic office BP 140-160 mm Hg despite treatment with three antihypertensive drugs including one diuretic, or mean systolic BP by 24-hour ambulatory BP measurement [ABPM] 135-150 mm Hg) were included. Two observational and one randomized cohort were identified (109 patients in the RDN group and 36 patients in the control group). Overall, the mean age of patients was 62±10 years, and 69.7% were male. Before-after comparison showed that RDN significantly reduced ABPM as compared with the baseline systolic ABPM, from 146.3±13 mm Hg at baseline to 134.6±14.7 mm Hg at 6-month follow-up and diastolic ABPM from 80.8±9.4 mm Hg at baseline to 75.5±9.8 mm Hg at 6-month follow up (both Phypertension. ©2017 Wiley Periodicals, Inc.

Endpoint design for future renal denervation trials - Novel implications for a new definition of treatment response to renal denervation.

Science.gov (United States)

Lambert, Thomas; Nahler, Alexander; Rohla, Miklos; Reiter, Christian; Grund, Michael; Kammler, Jürgen; Blessberger, Hermann; Kypta, Alexander; Kellermair, Jörg; Schwarz, Stefan; Starnawski, Jennifer A; Lichtenauer, Michael; Weiss, Thomas W; Huber, Kurt; Steinwender, Clemens

2016-10-01

Defining an adequate endpoint for renal denervation trials represents a major challenge. A high inter-individual and intra-individual variability of blood pressure levels as well as a partial or total non-adherence on antihypertensive drugs hamper treatment evaluations after renal denervation. Blood pressure measurements at a single point in time as used as primary endpoint in most clinical trials on renal denervation, might not be sufficient to discriminate between patients who do or do not respond to renal denervation. We compared the traditional responder classification (defined as systolic 24-hour blood pressure reduction of -5mmHg six months after renal denervation) with a novel definition of an ideal respondership (based on a 24h blood pressure reduction at no point in time, one, or all follow-up timepoints). We were able to re-classify almost a quarter of patients. Blood pressure variability was substantial in patients traditionally defined as responders. On the other hand, our novel classification of an ideal respondership seems to be clinically superior in discriminating sustained from pseudo-response to renal denervation. Based on our observations, we recommend that the traditional response classification should be reconsidered and possibly strengthened by using a composite endpoint of 24h-BP reductions at different follow-up-visits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Renal denervation: a new therapeutic approach for resistant hypertension.

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Cao, Longxing; Fu, Qiang; Wang, Binghui; Li, Zhiliang

2014-01-01

To review the advances in studies on renal denervation. References concerning renal denervation and resistant hypertension cited in this review were collected from PubMed published in English and those of renal denervation devices from official websites of device manufacturers up to January 2014. Articles with keywords "renal denervation" and "resistant hypertension" were selected. Renal and systemic sympathetic overactivity plays an important role in pathology of hypertension as well as other diseases characterized by sympathetic overactivity. Renal denervation is a new, catheter based procedure to reduce renal and systemic sympathetic overactivity by disruption of renal sympathetic efferent and afferent nerves through radiofrequency or ultrasound energy delivered to the endoluminal surface of both renal arteries. Although several studies have shown the efficacy and safety of renal denervation in the treatment of resistant hypertension and the potential benefit of the procedure in other diseases, Symplicity HTN 3 study, the most rigorous clinical trial of renal denervation to date, failed to meet its primary endpoint. The procedure also has other limitations such as the lack of long term, efficacy and safety data and the lack of the predictors for the blood pressure lowering response and nonresponse to the procedure. An overview of current renal denervation devices holding Conformité Européenne mark is also included in this review. Renal denervation is a promising therapeutic approach in the management of resistant hypertension and other diseases characterized by sympathetic overactivity. In its early stage of clinical application, the efficacy of the procedure is still controversial. Large scale, blind, randomized, controlled clinical trials are still necessary to address the limitations of the procedure.

Vagal nerve stimulation therapy: what is being stimulated?

Science.gov (United States)

Kember, Guy; Ardell, Jeffrey L; Armour, John A; Zamir, Mair

2014-01-01

Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

Vagal nerve stimulation therapy: what is being stimulated?

Directory of Open Access Journals (Sweden)

Guy Kember

Full Text Available Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

Anatomical and procedural determinants of ambulatory blood pressure lowering following catheter-based renal denervation using radiofrequency.

Science.gov (United States)

Lauder, Lucas; Ewen, Sebastian; Tzafriri, Abraham R; Edelman, Elazer R; Cremers, Bodo; Kulenthiran, Saarraaken; Ukena, Christian; Linz, Dominik; Kindermann, Ingrid; Tsioufis, Costas; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2018-03-02

Catheter-based renal sympathetic denervation (RDN) has been introduced to lower blood pressure (BP) and sympathetic activity in patients with uncontrolled hypertension with at best equivocal results. It has been postulated that anatomic and procedural elements introduce unaccounted variability and yet little is known of the impact of renal anatomy and procedural parameters on BP response to RDN. Anatomical parameters such as length and diameter were analyzed by quantitative vascular analysis and the prevalence of accessory renal arteries and renal artery disease were documented in 150 patients with resistant hypertension undergoing bilateral RDN using a mono-electrode radiofrequency catheter (Symplicity Flex, Medtronic). Accessory renal arteries and renal artery disease were present in 56 (37%) and 14 patients (9%), respectively. At 6-months, 24 h-ambulatory BP was reduced by 11/6 mm Hg (p renal arteries (p = 0.543) or renal artery disease (p = 0.598). Patients with at least one main renal artery diameter ≤ 4 mm had a more pronounced reduction of 24 h-ambulatory SBP compared to patients where both arteries were >4 mm (-19 vs. -10 mmHg; p = 0.038). Neither the length of the renal artery nor the number of RF ablations influenced 24 h-ambulatory BP reduction at 6 months. 24 h-ambulatory BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, accessory arteries or renal artery disease. Further, there was no dose-response relationship observed with increasing number of ablations. Because little is known of the impact of renal anatomy and procedural parameters on blood pressure (BP) response to renal denervation (RDN), anatomical and procedural data were analyzed in 150 patients undergoing bilateral RDN. BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, the presence of renal artery disease or accessory renal

Renal denervation: What happened, and why?

Science.gov (United States)

Shishehbor, Mehdi H; Hammad, Tarek A; Thomas, George

2017-09-01

Despite promising results in initial trials, renal denervation failed to achieve its efficacy end points as a treatment for resistant hypertension in the SYMPLICITY HTN-3 trial, the largest trial of this treatment to date (N Engl J Med 2014; 370:1393-1401). Is renal denervation dead, or will future trials and newer technology revive it? Copyright © 2017 Cleveland Clinic.

Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale.

Science.gov (United States)

Böhm, Michael; Ewen, Sebastian; Mahfoud, Felix

2017-01-01

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome.

Functional Echomyography of the human denervated muscle: first results

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Riccardo Zanato

2011-03-01

Full Text Available In this study we followed with ultrasound three patients with permanent denervation to evaluate changes in morphology, thickness, contraction and vascularisation of muscles undergoing the home-based electrical stimulation program of the Rise2-Italy project. During a period of 1 year for the first subject, 6 months for the second subject and 3 months for the third subject we studied with ultrasound the denervated muscle comparing it (if possible to the contralateral normal muscle. We evaluated: 1. Changes in morphology and sonographic structure of the pathologic muscle; 2. Muscular thickness in response to the electrical stimulation therapy; 3. Short-term modifications in muscle perfusion and arterial flow patterns after stimulation; 4. Contraction-relaxation kinetic induced by volitional activity or electrical stimulation. Morphology and ultrasonographic structure of the denervated muscles changed during the period of stimulation from a pattern typical of complete muscular atrophy to a pattern which might be considered “normal” when detected in an old patient. Thickness improved significantly more in the middle third than in the proximal and distal third of the denervated muscle, reaching in the last measurements of the first subject approximately the same thickness as the contralateral normal muscle. In all the measurements done within this study, arterial flow of the denervated muscle showed at rest a low-resistance pattern with Doppler Ultra Sound (US, and a pulsed pattern after electrical stimulation. The stimulation- induced pattern is similar to the trifasic high-resistance pattern of the normal muscle. Contraction- relaxation kinetic, measured by recording the muscular movements during electrical stimulation, showed an abnormal behaviour of the denervated muscle during the relaxation phase, which resulted to be significantly longer than in normal muscle (880 msec in the denervated muscle vs 240 msec in the contralateral normal one

Symplicity multi-electrode radiofrequency renal denervation system feasibility study.

Science.gov (United States)

Whitbourn, Robert; Harding, Scott A; Walton, Antony

2015-05-01

The aim of this study was to test the safety and performance of the Symplicity™ multi-electrode radio-frequency renal denervation system which was designed to reduce procedure time during renal denervation. The multi-electrode radiofrequency renal denervation system feasibility study is a prospective, non-randomised, open label, feasibility study that enrolled 50 subjects with hypertension. The study utilises a new renal denervation catheter which contains an array of four electrodes mounted in a helical configuration at 90 degrees from each other to deliver radiofrequency energy simultaneously to all four renal artery quadrants for 60 seconds. The protocol specified one renal denervation treatment towards the distal end of each main renal artery with radiofrequency energy delivered for 60 seconds per treatment. Total treatment time for both renal arteries was two minutes. The 12-month change in office systolic blood pressure (SBP) and 24-hour SBP was -19.2±25.2 mmHg, prenal artery stenosis or hypertensive emergencies occurred. The Symplicity multi-electrode radiofrequency renal denervation system was associated with a significant reduction in SBP at 12 months and minimal complications whilst it also reduced procedure time. NCT01699529.

Renal Denervation for Chronic Heart Failure: Background and Pathophysiological Rationale

Science.gov (United States)

Ewen, Sebastian; Mahfoud, Felix

2017-01-01

The activation of the sympathetic nervous system is associated with cardiovascular hospitalizations and death in heart failure. Renal denervation has been shown to effectively reduce sympathetic overdrive in certain patients with uncontrolled hypertension. Pilot trials investigating renal denervation as a potential treatment approach for heart failure were initiated. Heart failure comorbidities like obstructive sleep apnea, metabolic syndrome and arrhythmias could also be targets for renal denervation, because these occurrences are also mediated by the activation of the sympathetic nervous system. Therefore, renal denervation in heart failure is worthy of further investigation, although its effectiveness still has to be proven. Herein, we describe the pathophysiological rationale and the effect of renal denervation on surrogates of the heart failure syndrome. PMID:28154583

EFFECTS OF VAGAL SENSORY INPUT ON THE BREATHING RHYTHM OF THE CARP

NARCIS (Netherlands)

DEGRAAF, PJF; ROBERTS, BL

Electrical stimulation of an epibranchial vagal ganglion, which innervates the gill region, had a marked influence on the respiratory rhythm of the carp Cyprinus carpio. Vagal input could initiate ventilation in fish displaying intermittent respiration. In fish breathing steadily, vagal stimuli

Renal denervation after Symplicity HTN-3: an update.

Science.gov (United States)

Persu, Alexandre; Jin, Yu; Fadl Elmula, Fadl Elmula Mohamed; Jacobs, Lotte; Renkin, Jean; Kjeldsen, Sverre

2014-08-01

After three years of excessive confidence, overoptimistic expectations and performance of 15 to 20,000 renal denervation procedures in Europe, the failure of a single well-designed US trial--Symplicity HTN-3--to meet its primary efficacy endpoint has cast doubt on renal denervation as a whole. The use of a sound methodology, including randomisation and blinded endpoint assessment was enough to see the typical 25-30 mmHg systolic blood pressure decrease observed after renal denervation melt down to less than 3 mmHg, the rest being likely explained by Hawthorne and placebo effects, attenuation of white coat effect, regression to the mean and other physician and patient-related biases. The modest blood pressure benefit directly assignable to renal denervation should be balanced with unresolved safety issues, such as potentially increased risk of renal artery stenosis after the procedure (more than ten cases reported up to now, most of them in 2014), unclear long-term impact on renal function and lack of morbidity-mortality data. Accordingly, there is no doubt that renal denervation is not ready for clinical use. Still, renal denervation is supported by a strong rationale and is occasionally followed by major blood pressure responses in at-risk patients who may otherwise have remained uncontrolled. Upcoming research programmes should focus on identification of those few patients with truly resistant hypertension who may derive a substantial benefit from the technique, within the context of well-designed randomised trials and independent registries. While electrical stimulation of baroreceptors and other interventional treatments of hypertension are already "knocking at the door", the premature and uncontrolled dissemination of renal denervation should remain an example of what should not be done, and trigger radical changes in evaluation processes of new devices by national and European health authorities.

Denervation-induced homeostatic dendritic plasticity in morphological granule cell models

Directory of Open Access Journals (Sweden)

Hermann Cuntz

2014-03-01

Full Text Available Neuronal death and subsequent denervation of target areas are major consequences of several neurological conditions such asischemia or neurodegeneration (Alzheimer's disease. The denervation-induced axonal loss results in reorganization of the dendritic tree of denervated neurons. The dendritic reorganization has been previously studied using entorhinal cortex lesion (ECL. ECL leads to shortening and loss of dendritic segments in the denervated outer molecular layer of the dentate gyrus. However, the functional importance of these long-term dendritic alterations is not yet understood and their impact on neuronal electrical properties remains unclear. Here we analyzed what happens to the electrotonic structure and excitability of dentate granule cells after lesion-induced alterations of their dendritic morphology, assuming all other parameters remain equal. We performed comparative electrotonic analysis in anatomically and biophysically realistic compartmental models of 3D-reconstructed healthy and denervated granule cells. Using the method of morphological modeling based on optimization principles minimizing the amount of wiring and maximizing synaptic democracy, we built artificial granule cells which replicate morphological features of their real counterparts. Our results show that somatofugal and somatopetal voltage attenuation in the passive cable model are strongly reduced in denervated granule cells. In line with these predictions, the attenuation both of simulated backpropagating action potentials and forward propagating EPSPs was significantly reduced in dendrites of denervated neurons. Intriguingly, the enhancement of action potential backpropagation occurred specifically in the denervated dendritic layers. Furthermore, simulations of synaptic f-I curves revealed a homeostatic increase of excitability in denervated granule cells. In summary, our morphological and compartmental modeling indicates that unless modified by changes of

Modulation of experimental arthritis by vagal sensory and central brain stimulation.

Science.gov (United States)

Bassi, Gabriel Shimizu; Dias, Daniel Penteado Martins; Franchin, Marcelo; Talbot, Jhimmy; Reis, Daniel Gustavo; Menezes, Gustavo Batista; Castania, Jaci Airton; Garcia-Cairasco, Norberto; Resstel, Leonardo Barbosa Moraes; Salgado, Helio Cesar; Cunha, Fernando Queiróz; Cunha, Thiago Mattar; Ulloa, Luis; Kanashiro, Alexandre

2017-08-01

Articular inflammation is a major clinical burden in multiple inflammatory diseases, especially in rheumatoid arthritis. Biological anti-rheumatic drug therapies are expensive and increase the risk of systemic immunosuppression, infections, and malignancies. Here, we report that vagus nerve stimulation controls arthritic joint inflammation by inducing local regulation of innate immune response. Most of the previous studies of neuromodulation focused on vagal regulation of inflammation via the efferent peripheral pathway toward the viscera. Here, we report that vagal stimulation modulates arthritic joint inflammation through a novel "afferent" pathway mediated by the locus coeruleus (LC) of the central nervous system. Afferent vagal stimulation activates two sympatho-excitatory brain areas: the paraventricular hypothalamic nucleus (PVN) and the LC. The integrity of the LC, but not that of the PVN, is critical for vagal control of arthritic joint inflammation. Afferent vagal stimulation suppresses articular inflammation in the ipsilateral, but not in the contralateral knee to the hemispheric LC lesion. Central stimulation is followed by subsequent activation of joint sympathetic nerve terminals inducing articular norepinephrine release. Selective adrenergic beta-blockers prevent the effects of articular norepinephrine and thereby abrogate vagal control of arthritic joint inflammation. These results reveals a novel neuro-immune brain map with afferent vagal signals controlling side-specific articular inflammation through specific inflammatory-processing brain centers and joint sympathetic innervations. Copyright © 2017 Elsevier Inc. All rights reserved.

High incidence of secondary hypertension in patients referred for renal denervation

DEFF Research Database (Denmark)

Olsen, Lene Kjær; Kamper, Anne-Lise; Svendsen, Jesper Hastrup

2014-01-01

. Thus, 91 patients were screened, and of those 51 were found to be candidates for renal denervation. Forty patients were not candidates, of which secondary hypertension was the most common cause (n = 10). Only 51% of patients referred for renal denervation were eligible for treatment. The prevalence...... of secondary hypertension was 10% of the referred population. Secondary hypertension should therefore be considered in the evaluation of candidates for renal denervation.......Percutaneous renal denervation is a new treatment option for patients with resistant hypertension and little is known about the eligibility of patients referred. 100 consecutive patients were referred for renal denervation from March 2011 through September 2012. Clinical data were prospectively...

Self-esteem fluctuations and cardiac vagal control in everyday life.

Science.gov (United States)

Schwerdtfeger, Andreas R; Scheel, Sophie-Marie

2012-03-01

It has been proposed that self-esteem buffers threat-responding. The same effect is ascribed to the vagus nerve, which is a primary nerve of the parasympathetic nervous system. Consequently, it has been suggested that self-esteem and cardiac vagal tone are interconnected on a trait, as well as on a state, level. In this study, we examined the relationship of vagal cardiac control and self-esteem fluctuations across a single day using ecological momentary assessment. Eighty-four participants were recruited, and self-esteem, negative affect, and vagal tone were recorded throughout a 22-hour period. Men provided higher self-esteem ratings than women, but the negative relationship between self-esteem and negative affect was stronger in women. Moreover, controlling for potential confounds (e.g., age, BMI, depressive symptoms, smoking status, regular physical activity), we observed that for men, self-esteem was significantly positively associated with cardiac vagal tone, whereas for women it was not. These findings suggest that the relationship between self-esteem and vagal innervation of the heart during daily life is sex-specific and might involve different central-autonomic pathways for men and women, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

Renal denervation for resistant hypertension using an irrigated radiofrequency balloon: 12-month results from the Renal Hypertension Ablation System (RHAS) trial.

Science.gov (United States)

Ormiston, John A; Watson, Timothy; van Pelt, Niels; Stewart, Ralph; Stewart, James T; White, Jonathon M; Doughty, Robert N; Stewart, Fiona; Macdonald, Rhona; Webster, Mark W I

2013-05-20

Renal denervation using the point-by-point application of radiofrequency energy delivered by the first-generation Symplicity system is effective in lowering office blood pressure but may be time-consuming. The OneShot Renal Denervation System with a balloon-mounted spiral electrode potentially shortens and simplifies the procedure. This study is a hypothesis-generating first-in-human study to assess feasibility, and to provide preliminary efficacy and safety data. Eligible patients had a baseline office systolic blood pressure ≥160 mmHg (or ≥150 mmHg for diabetics) and were on two or more antihypertensive medications. Nine patients were enrolled. The primary endpoint, the insertion of the OneShot balloon into each renal artery and the delivery of radiofrequency energy, was achieved in 8/9 (89%) of patients. The one failure (the first patient) was due to generator high-impedance safety shut-off threshold set too low for humans. Adverse events were minor. No patient developed renal artery stenosis. Baseline BP was 185.67 ± 18.7 mmHg and the reductions at 1, 3, 6 and 12 months were 30.1 ± 13.6 (p=0.0004), 34.2 ± 20.2 (p=0.002), 33.6 ± 32.2 (p=0.021) and 30.6 ± 22.0 (p=0.019). The OneShot renal denervation system successfully delivered radiofrequency energy to the renal arteries in a short and straightforward procedure. Australian New Zealand Clinical Trials Registry - URL: anzctr.org.au. Trial identification: ACTRN12611000987965.

Renal Sympathetic Denervation by CT-scan-Guided Periarterial Ethanol Injection in Sheep

Energy Technology Data Exchange (ETDEWEB)

Firouznia, Kavous, E-mail: k-firouznia@yahoo.com; Hosseininasab, Sayed jaber, E-mail: dr.hosseininasab@gmail.com [Tehran University of Medical Sciences (TMUS), Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Amanpour, Saeid, E-mail: saeidamanpour@yahoo.com [Tehran University of Medical Science, Cancer Models Research Center, Cancer Institute of Iran (Iran, Islamic Republic of); Haj-Mirzaian, Arya, E-mail: arya.mirzaian@gmail.com [Tehran University of Medical Science, Department of Radiology and Imaging, MIC, Imam Khomeini Hospital (Iran, Islamic Republic of); Miri, Roza, E-mail: rosa.miri@yahoo.com [Tehran University of Medical Science, Department of Pathology, Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Muhammadnejad, Ahad, E-mail: mohamadnejad@yahoo.com [Tehran University of Medical Science, Cancer Research Center, Cancer Institute of Iran (Iran, Islamic Republic of); Muhammadnejad, Samad, E-mail: s-muhammadnejad@sina.tums.ac.ir [Tehran University of Medical Sciences, Research Center for Molecular and Cellular Imaging (Iran, Islamic Republic of); Jalali, Amir H., E-mail: amirjalali51@yahoo.com [Tehran University of Medical Sciences (TMUS), Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Ahmadi, Farrokhlagha, E-mail: ahmadi@tums.ac.ir [Tehran University of Medical Sciences, Nephrology Research Center, Imam Khomeini Hospital Complex (Iran, Islamic Republic of); Rokni-Yazdi, Hadi, E-mail: rokniyaz@tums.ac.ir [Tehran University of Medical Sciences (TMUS), Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital Complex (Iran, Islamic Republic of)

2015-08-15

BackgroundRenal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD.AimTo evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection.MethodsEthanol (10 ml, 99.6 %) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury.ResultsThe right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40 %, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies.ConclusionEffective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension.

Renal Sympathetic Denervation by CT-scan-Guided Periarterial Ethanol Injection in Sheep

International Nuclear Information System (INIS)

Firouznia, Kavous; Hosseininasab, Sayed jaber; Amanpour, Saeid; Haj-Mirzaian, Arya; Miri, Roza; Muhammadnejad, Ahad; Muhammadnejad, Samad; Jalali, Amir H.; Ahmadi, Farrokhlagha; Rokni-Yazdi, Hadi

2015-01-01

BackgroundRenal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD.AimTo evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection.MethodsEthanol (10 ml, 99.6 %) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury.ResultsThe right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40 %, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies.ConclusionEffective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension

Breathing exercises with vagal biofeedback may benefit patients with functional dyspepsia.

Science.gov (United States)

Hjelland, Ina E; Svebak, Sven; Berstad, Arnold; Flatabø, Geir; Hausken, Trygve

2007-09-01

Many patients with functional dyspepsia (FD) have postprandial symptoms, impaired gastric accommodation and low vagal tone. The aim of this study was to improve vagal tone, and thereby also drinking capacity, intragastric volume and quality of life, using breathing exercises with vagal biofeedback. Forty FD patients were randomized to either a biofeedback group or a control group. The patients received similar information and care. Patients in the biofeedback group were trained in breathing exercises, 6 breaths/min, 5 min each day for 4 weeks, using specially designed software for vagal biofeedback. Effect variables included maximal drinking capacity using a drink test (Toro clear meat soup 100 ml/min), intragastric volume at maximal drinking capacity, respiratory sinus arrhythmia (RSA), skin conductance (SC) and dyspepsia-related quality of life scores. Drinking capacity and quality of life improved significantly more in the biofeedback group than in the control group (p=0.02 and p=0.01) without any significant change in baseline autonomic activity (RSA and SC) or intragastric volume. After the treatment period, RSA during breathing exercises was significantly correlated to drinking capacity (r=0.6, p=0.008). Breathing exercises with vagal biofeedback increased drinking capacity and improved quality of life in FD patients, but did not improve baseline vagal tone.

Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

International Nuclear Information System (INIS)

Liu, Xin-Hua; Yao, Shen; Qiao, Rui-Fang; Levine, Alice C.; Kirschenbaum, Alexander; Pan, Jiangping; Wu, Yong; Qin, Weiping; Bauman, William A.; Cardozo, Christopher P.

2011-01-01

Highlights: → Nerve transection increased Notch signaling in paralyzed muscle. → Nandrolone prevented denervation-induced Notch signaling. → Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. → Reduction of denervation-induced Notch signaling by nandrolone is likely through upregulation of Numb. -- Abstract: Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression

Energy Technology Data Exchange (ETDEWEB)

Liu, Xin-Hua [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Yao, Shen; Qiao, Rui-Fang; Levine, Alice C. [Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Kirschenbaum, Alexander [Department of Urology, Mount Sinai School of Medicine, New York, NY 10029 (United States); Pan, Jiangping; Wu, Yong [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Qin, Weiping [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Bauman, William A. [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Cardozo, Christopher P., E-mail: chris.cardozo@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States); Rehabilitation Medicine, Mount Sinai School of Medicine, New York, NY 10029 (United States)

2011-10-14

Highlights: {yields} Nerve transection increased Notch signaling in paralyzed muscle. {yields} Nandrolone prevented denervation-induced Notch signaling. {yields} Nandrolone induced the expression of an inhibitor of the Notch signaling, Numb. {yields} Reduction of denervation-induced Notch signaling by nandrolone is likely through upregulation of Numb. -- Abstract: Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

[Expert consensus statement on interventional renal sympathetic denervation for hypertension treatment].

Science.gov (United States)

Mahfoud, F; Vonend, O; Bruck, H; Clasen, W; Eckert, S; Frye, B; Haller, H; Hausberg, M; Hoppe, U C; Hoyer, J; Hahn, K; Keller, T; Krämer, B K; Kreutz, R; Potthoff, S A; Reinecke, H; Schmieder, R; Schwenger, V; Kintscher, U; Böhm, M; Rump, L C

2011-11-01

This commentary summarizes the expert consensus and recommendations of the working group 'Herz und Niere' of the German Society of Cardiology (DGK), the German Society of Nephrology (DGfN) and the German Hypertension League (DHL) on renal denervation for antihypertensive treatment. Renal denervation is a new, interventional approach to selectively denervate renal afferent and efferent sympathetic fibers. Renal denervation has been demonstrated to reduce office systolic and diastolic blood pressure in patients with resistant hypertension, defined as systolic office blood pressure ≥ 160 mm Hg and ≥ 150 mm Hg in patients with diabetes type 2, which should currently be used as blood pressure thresholds for undergoing the procedure. Exclusion of secondary hypertension causes and optimized antihypertensive drug treatment is mandatory in every patient with resistant hypertension. In order to exclude pseudoresistance, 24-hour blood pressure measurements should be performed. Preserved renal function was an inclusion criterion in the Symplicity studies, therefore, renal denervation should be only considered in patients with a glomerular filtration rate > 45 ml/min. Adequate centre qualification in both, treatment of hypertension and interventional expertise are essential to ensure correct patient selection and procedural safety. Long-term follow-up after renal denervation and participation in the German Renal Denervation (GREAT) Registry are recommended to assess safety and efficacy after renal denervation over time. © Georg Thieme Verlag KG Stuttgart · New York.

Renin angiotensin system and cardiac hypertrophy after sinoaortic denervation in rats

Directory of Open Access Journals (Sweden)

Aline Cristina Piratello

2010-01-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the role of angiotensin I, II and 1-7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation. METHODS: Ten weeks after sinoaortic denervation, hemodynamic and morphofunctional parameters were analyzed, and the left ventricle was dissected for biochemical analyses. RESULTS: Hypertensive groups (controls and denervated showed an increase on mean blood pressure compared with normotensive ones (controls and denervated. Blood pressure variability was higher in denervated groups than in their respective controls. Left ventricular mass and collagen content were increased in the normotensive denervated and in both spontaneously hypertensive groups compared with Wistar controls. Both hypertensive groups presented a higher concentration of angiotensin II than Wistar controls, whereas angiotensin 1-7 concentration was decreased in the hypertensive denervated group in relation to the Wistar groups. There was no difference in angiotensin I concentration among groups. CONCLUSION: Our results suggest that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1-7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.

Predictors of Renal Denervation Efficacy in the Treatment of Resistant Hypertension.

Science.gov (United States)

Ripp, Tatiana M; Mordovin, Victor F; Pekarskiy, Stanislav E; Ryabova, Tamara R; Zlobina, Marina V; Baev, Andrei E; Anfinogenova, Yana; Popov, Sergey V

2015-12-01

The aims of the study were to evaluate the effects of renal sympathetic denervation (RSD) on the heart and to identify the predictors of RSD efficacy in patients with resistant arterial hypertension. The study comprised 60 RSD patients (54.6 ± 9.5 years) who received full-dose antihypertensive therapy (4.1 drugs) including diuretics. Initially, 58.6% of patients had abnormal left ventricular (LV) diastolic function. All patients received echocardiography before and 24 weeks after RSD. Renal sympathetic denervation was achieved through the endovascular radiofrequency ablation (RFA) of the renal arteries. Drug therapy continued for the entire period of observation. After RSD, all patients were retrospectively assigned to two groups: group 1 comprised patients (n = 22; 36.7%) in whom the myocardial mass (MM) of the left ventricle decreased by more than 10 g after RSD; group 2 comprised patients (n = 38; 63.3%) in whom LV MM increased or decreased by less than 10 g. Anthropometry, arterial blood pressure, heart rate, therapy, and LV end-diastolic dimensions (EDD) were comparable in these groups. After RSD, the values of office blood pressure significantly decreased and MM regressed by more than 10 g in 36.7% of patients; LV diastolic function normalized in 31% of patients, and diastolic dysfunction improved in 14% of patients. The study found the associations between the initial LV wall dimensions and LV MM changes. Unlike LV EDD, arterial blood pressure, or heart rate, the initial values of LV wall thickness predicted LV MM regress. #NCT01499810 https://clinicaltrials.gov/ct2/show/NCT01499810.

Effect of salbutamol on innervated and denervated rat soleus muscle

Directory of Open Access Journals (Sweden)

?oic-Vranic T.

2005-01-01

Full Text Available The objective of the present investigation was to perform a 14-day time-course study of treatment with salbutamol, a ß2 adrenoceptor agonist, on rat soleus muscle in order to assess fiber type selectivity in the hypertrophic response and fiber type composition. Male Wistar rats were divided into four groups: control (N = 10, treated with salbutamol (N = 30, denervated (N = 30, and treated with salbutamol after denervation (N = 30. Salbutamol was injected intraperitoneally in the rats of the 2nd and 4th groups at a concentration of 0.3 mg/kg twice a day for 2 weeks. The muscles were denervated using the crush method with pean. The animals were sacrificed 3, 6, 9, 12, and 14 days after treatment. Frozen cross-sections of soleus muscle were stained for myosin ATPase, pH 9.4. Cross-sectional area and percent of muscle fibers were analyzed morphometrically by computerized image analysis. Treatment with salbutamol induced hypertrophy of all fiber types and a higher percentage of type II fibers (21% in the healthy rat soleus muscle. Denervation caused marked atrophy of all fibers and conversion from type I to type II muscle fibers. Denervated muscles treated with salbutamol showed a significantly larger cross-sectional area of type I muscle fibers, 28.2% compared to the denervated untreated muscle. Moreover, the number of type I fibers was increased. These results indicate that administration of salbutamol is able to induce changes in cross-sectional area and fiber type distribution in the early phase of treatment. Since denervation-induced atrophy and conversion from type I to type II fibers were improved by salbutamol treatment we propose that salbutamol, like other ß2 adrenoceptor agonists, may have a therapeutic potential in improving the condition of skeletal muscle after denervation.

Gut vagal afferents differentially modulate innate anxiety and learned fear.

Science.gov (United States)

Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

2014-05-21

Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior. Copyright © 2014 the authors 0270-6474/14/347067-10$15.00/0.

Renal sympathetic denervation: MDCT evaluation of the renal arteries.

LENUS (Irish Health Repository)

Hutchinson, Barry D

2013-08-01

Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

Vagal Blocking for Obesity Control

DEFF Research Database (Denmark)

Johannessen, Helene; Revesz, David; Kodama, Yosuke

2017-01-01

: VBLOC reduced body weight and food intake, which was associated with increased satiety but not with decreased hunger. Brain activities in response to VBLOC included increased gene expression of leptin and CCKb receptors, interleukin-1β, tumor necrosis factor, and transforming growth factor β1......BACKGROUND: Recently, the US FDA has approved "vagal blocking therapy or vBLoc® therapy" as a new treatment for obesity. The aim of the present study was to study the mechanism-of-action of "VBLOC" in rat models. METHODS: Rats were implanted with VBLOC, an intra-abdominal electrical device...... with leads placed around gastric vagal trunks through an abdominal incision and controlled by wireless device. Body weight, food intake, hunger/satiety, and metabolic parameters were monitored by a comprehensive laboratory animal monitoring system. Brain-gut responses were analyzed physiologically. RESULTS...

Intrapericardial Denervation: Responses to Water Immersion in Rhesus Monkeys

Science.gov (United States)

McKeever, Kenneth H.; Keil, Lanny C.; Sandler, Harold

1995-01-01

Eleven anesthetized rhesus monkeys were used to study cardiovascular, renal, and endocrine alterations associated with 120 min of head-out water immersion. Five animals underwent complete intrapericardial denervation using the Randall technique, while the remaining six monkeys served as intact controls. Each animal was chronically instrumented with an electromagnetic flow probe on the ascending aorta, a strain gauge pressure transducer implanted in the apex of the left ventricle (LV), and electrocardiogram leads anchored to the chest wall and LV. During immersion, LV end-diastolic pressure, urine flow, glomerular filtration rate, sodium excretion, and circulating atrial natriuretic peptide (ANP) each increased (P less than 0.05) for intact and denervated monkeys. There were no alterations in free water clearance in either group during immersion, yet fractional excretion of free water increased (P less than 0.05) in the intact monkeys. Plasma renin activity (PRA) decreased (P less than 0.05) during immersion in intact monkeys but not the denervated animals. Plasma vasopressin (PVP) concentration decreased (P less than 0.05) during the first 30 min of immersion in both groups but was not distinguishable from control by 60 min of immersion in denervated monkeys. These data demonstrate that complete cardiac denervation does not block the rise in plasma ANP or prevent the natriuresis associated with head-out water immersion. The suppression of PVP during the first minutes of immersion after complete cardiac denervation suggests that extracardiac sensing mechanisms associated with the induced fluid shifts may be responsible for the findings.

Evidence for a vagal pathophysiology for bulimia nervosa and the accompanying depressive symptoms.

Science.gov (United States)

Faris, Patricia L; Eckert, Elke D; Kim, Suck-Won; Meller, William H; Pardo, Jose V; Goodale, Robert L; Hartman, Boyd K

2006-05-01

The bilateral vagus nerves (Cranial X) provide both afferent and efferent connections between the viscera and the caudal medulla. The afferent branches increasingly are being recognized as providing significant input to the central nervous system for modulation of complex behaviors. In this paper, we review evidence from our laboratory that increases in vagal afferent activity are involved in perpetuating binge-eating and vomiting in bulimia nervosa. Preliminary findings are also presented which suggest that a subgroup of depressions may have a similar pathophysiology. Two main approaches were used to study the role of vagal afferents. Ondansetron (ONDAN), a 5-HT3 antagonist, was used as a pharmacological tool for inhibiting or reducing vagal afferent neurotransmission. Second, somatic pain detection thresholds were assessed for monitoring a physiological process known to be modulated by vagal afferents, including the gastric branches involved in meal termination and satiety. High levels of vagal activity result in an increase in pain detection thresholds. Depressive symptoms were assessed using the Beck Depression Inventory (BDI). Positron Emission Tomography (PET) was used to identify higher cortical brain areas activated by vagal stimulation produced by proximal gastric distention in normal eating subjects. Double-blind treatment of severe bulimia nervosa subjects with ONDAN resulted in a rapid and significant decrease in binge-eating and vomiting compared to placebo controls. The decrease in abnormal eating episodes was accompanied by a return of normal satiety. Pain detection thresholds measured weekly over the course of the treatment protocol were found to dynamically fluctuate in association with bulimic episodes. Thresholds were the most elevated during periods of short-term abstinence from the behaviors, suggesting that not engaging in a binge/vomit episode is accompanied by an increase in vagal activity. ONDAN also resulted in abolition of the

Modulation of the masseteric reflex by gastric vagal afferents.

Science.gov (United States)

Pettorossi, V E

1983-04-01

Several investigations have shown that the vagal nerve can affect the reflex responses of the masticatory muscles acting at level either of trigeminal motoneurons or of the mesencephalic trigeminal nucleus (MTN). The present experiments have been devoted to establish the origin of the vagal afferent fibres involved in modulating the masseteric reflex. In particular, the gastric vagal afferents were taken into consideration and selective stimulations of such fibres were performed in rabbit. Conditioning electrical stimulation of truncus vagalis ventralis (TVV) reduced the excitability of the MTN cells as shown by a decrease of the antidromic response recorded from the semilunar ganglion and elicited by MTN single-shock electrical stimulation. Sympathetic and cardiovascular influences were not involved in these responses. Mechanical stimulation of gastric receptors, by means of gastric distension, clearly diminished the amplitude of twitch tension of masseteric reflex and inhibited the discharge frequency of proprioceptive MTN units. The effect was phasic and depended upon the velocity of distension. Thus the sensory volleys originating from rapid adapting receptors reach the brain stem through vagal afferents and by means of a polysynaptic connection inhibits the masseteric reflex at level of MTN cells.

Next generation renal denervation: chemical “perivascular” renal denervation with alcohol using a novel drug infusion catheter

Energy Technology Data Exchange (ETDEWEB)

Fischell, Tim A. [Borgess Heart Institute, 1521 Gull Road, Kalamazoo, MI, 49008 (United States); Ablative Solutions, 801 Hermosa Way, Menlo Park, CA, 94025 (United States); Fischell, David R.; Ghazarossian, Vartan E. [Ablative Solutions, 801 Hermosa Way, Menlo Park, CA, 94025 (United States); Vega, Félix [Preclinical Consultation, San Francisco, CA (United States); Ebner, Adrian [Clinics, Ascension (Paraguay)

2015-06-15

Background/Purpose: We update the pre-clinical and early clinical results using a novel endovascular approach, to perform chemical renal denervation, via peri-adventitial injection of micro-doses of dehydrated alcohol (ethanol–EtOH). Methods/Materials: A novel, three-needle delivery device (Peregrine™) was used to denervate the renal arteries of adult swine (n = 17) and in a first-in-man feasibility study (n = 18). In the pre-clinical testing EtOH was infused bilaterally with one infusion per renal artery into to the perivascular space, using EtOH doses of 0.3 ml/artery (n = 8), and 0.6 ml/artery (n = 9), and with saline sham control (0.4 ml/artery n = 3). Renal parenchymal norepinephrine (NE) concentration (performed blindly), and safety were the primary endpoints. Data from the first-in-man study (n = 18) to evaluate device performance, safety and peri-procedural pain are reported. Results: In the pre-clinical testing renal function was unchanged at 3-month follow-up. Angiography at 90 days (n = 34 arteries) demonstrated normal appearing renal arteries, unchanged from baseline, and without stenosis or other abnormalities. The reductions in mean renal parenchymal NE reductions at 3 months were 68% and 88% at doses of 0.3 and 0.6 ml, respectively (p < 0.001 vs. controls). In the first-in-man study, there was 100% device success, no complications, a mean treatment time of 4.3 ± 3 minutes/artery, and minimal or no patient discomfort during treatment. Angiography at 6-months showed no evidence of renal artery stenosis, and evidence of a reduction of blood pressure from baseline. Conclusion: Perivascular RDN using micro-doses of alcohol is a promising alternative to energy-based systems to achieve dose-dependent, predictable, safe and essentially painless renal denervation. Further clinical evaluation is warranted. Summary: (For annotated table of contents) This paper describes the preclinical results, in a porcine model, and the early first-in-man results, using

Malignant vagal paraganglioma

DEFF Research Database (Denmark)

Carlsen, Camilla S; Godballe, Christian; Krogdahl, Annelise S

2003-01-01

Approximately 20 cases of malignant vagal paragangliomas (MVP)have been reported in English literature. Malignancy is based on the presence of metastases. A careful preoperative evaluation is necessary to detect multicentricity and/or significant production of catecholamines. A new case of MVP...... treated with embolization and surgery is presented and the literature discussed. It is concluded, that preoperative embolization followed by radical surgical resection is a rational treatment of patients with unilateral MVP....

Accurate Depth of Radiofrequency-Induced Lesions in Renal Sympathetic Denervation Based on a Fine Histological Sectioning Approach in a Porcine Model.

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Sakaoka, Atsushi; Terao, Hisako; Nakamura, Shintaro; Hagiwara, Hitomi; Furukawa, Toshihito; Matsumura, Kiyoshi; Sakakura, Kenichi

2018-02-01

Ablation lesion depth caused by radiofrequency-based renal denervation (RDN) was limited to radiofrequency-RDN cannot ablate a substantial percentage of renal sympathetic nerves. We aimed to define the true lesion depth achieved with radiofrequency-RDN using a fine sectioning method and to investigate biophysical parameters that could predict lesion depth. Radiofrequency was delivered to 87 sites in 14 renal arteries from 9 farm pigs at various ablation settings: 2, 4, 6, and 9 W for 60 seconds and 6 W for 120 seconds. Electric impedance and electrode temperature were recorded during ablation. At 7 days, 2470 histological sections were obtained from the treated arteries. Maximum lesion depth increased at 2 to 6 W, peaking at 6.53 (95% confidence interval, 4.27-8.78) mm under the 6 W/60 s condition. It was not augmented by greater power (9 W) or longer duration (120 seconds). There were statistically significant tendencies at 6 and 9 W, with higher injury scores in the media, nerves, arterioles, and fat. Maximum lesion depth was positively correlated with impedance reduction and peak electrode temperature (Pearson correlation coefficients were 0.59 and 0.53, respectively). Lesion depth was 6.5 mm for radiofrequency-RDN at 6 W/60 s. The impedance reduction and peak electrode temperature during ablation were closely associated with lesion depth. Hence, these biophysical parameters could provide prompt feedback during radiofrequency-RDN procedures in the clinical setting. © 2018 The Authors.

Selective peripheral denervation: comparison with pallidal stimulation and literature review

NARCIS (Netherlands)

Contarino, Maria Fiorella; van den Munckhof, Pepijn; Tijssen, Marina A. J.; de Bie, Rob M. A.; Bosch, D. Andries; Schuurman, P. Richard; Speelman, Johannes D.

2014-01-01

Patients with cervical dystonia who are non-responders to Botulinum toxin qualify for surgery. Selective peripheral denervation (Bertrand's procedure, SPD) and deep brain stimulation of the globus pallidus (GPi-DBS) are available surgical options. Although peripheral denervation has potential

Asystole Following Profound Vagal Stimulation During Hepatectomy

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Preeta John

2008-01-01

Full Text Available Asystole in a non laparoscopic upper abdominal surgery following intense vagal stimulation is a rare event. This case report highlights the need for awareness of such a complication when a thoracic epidural anaesthetic has been given in addition to a general anaesthetic for an upper abdominal procedure. A combined thoracic epidural and general anaesthetic was given. The anterior abdominal wall was retracted forty minutes after administration of the epidural bolus. This maneuver resulted in a profound vagal response with bradycardia and asystole. The patient was resuscitated successfully with a cardiac massage, atropine and adrenaline and the surgery was resumed. Surgery lasted eleven hours and was uneventful.

Adherence to Antihypertensive Treatment and the Blood Pressure-Lowering Effects of Renal Denervation in the Renal Denervation for Hypertension (DENERHTN) Trial.

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Azizi, Michel; Pereira, Helena; Hamdidouche, Idir; Gosse, Philippe; Monge, Matthieu; Bobrie, Guillaume; Delsart, Pascal; Mounier-Véhier, Claire; Courand, Pierre-Yves; Lantelme, Pierre; Denolle, Thierry; Dourmap-Collas, Caroline; Girerd, Xavier; Michel Halimi, Jean; Zannad, Faiez; Ormezzano, Olivier; Vaïsse, Bernard; Herpin, Daniel; Ribstein, Jean; Chamontin, Bernard; Mourad, Jean-Jacques; Ferrari, Emile; Plouin, Pierre-François; Jullien, Vincent; Sapoval, Marc; Chatellier, Gilles

2016-09-20

The DENERHTN trial (Renal Denervation for Hypertension) confirmed the blood pressure-lowering efficacy of renal denervation added to a standardized stepped-care antihypertensive treatment for resistant hypertension at 6 months. We report the influence of adherence to antihypertensive treatment on blood pressure control. One hundred six patients with hypertension resistant to 4 weeks of treatment with indapamide 1.5 mg/d, ramipril 10 mg/d (or irbesartan 300 mg/d), and amlodipine 10 mg/d were randomly assigned to renal denervation plus standardized stepped-care antihypertensive treatment, or the same antihypertensive treatment alone. For standardized stepped-care antihypertensive treatment, spironolactone 25 mg/d, bisoprolol 10 mg/d, prazosin 5 mg/d, and rilmenidine 1 mg/d were sequentially added at monthly visits if home blood pressure was ≥135/85 mm Hg after randomization. We assessed adherence to antihypertensive treatment at 6 months by drug screening in urine/plasma samples from 85 patients. The numbers of fully adherent (20/40 versus 21/45), partially nonadherent (13/40 versus 20/45), or completely nonadherent patients (7/40 versus 4/45) to antihypertensive treatment were not different in the renal denervation and the control groups, respectively (P=0.3605). The difference in the change in daytime ambulatory systolic blood pressure from baseline to 6 months between the 2 groups was -6.7 mm Hg (P=0.0461) in fully adherent and -7.8 mm Hg (P=0.0996) in nonadherent (partially nonadherent plus completely nonadherent) patients. The between-patient variability of daytime ambulatory systolic blood pressure was greater for nonadherent than for fully adherent patients. In the DENERHTN trial, the prevalence of nonadherence to antihypertensive drugs at 6 months was high (≈50%) but not different in the renal denervation and control groups. Regardless of adherence to treatment, renal denervation plus standardized stepped-care antihypertensive treatment resulted in

MR-guided Periarterial Ethanol Injection for Renal Sympathetic Denervation: A Feasibility Study in Pigs

International Nuclear Information System (INIS)

Streitparth, F.; Walter, A.; Stolzenburg, N.; Heckmann, L.; Breinl, J.; Rinnenthal, J. L.; Beck, A.; De Bucourt, M.; Schnorr, J.; Bernhardt, U.; Gebauer, B.; Hamm, B.; Günther, R. W.

2013-01-01

Purpose. To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation. Methods. Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served as a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury. Results. In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig. Conclusion. MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.

MR-guided Periarterial Ethanol Injection for Renal Sympathetic Denervation: A Feasibility Study in Pigs

Energy Technology Data Exchange (ETDEWEB)

Streitparth, F., E-mail: florian.streitparth@charite.de; Walter, A.; Stolzenburg, N.; Heckmann, L.; Breinl, J. [Charite, Humboldt University, Department of Radiology (Germany); Rinnenthal, J. L. [Charite, Humboldt University, Department of Neuropathology (Germany); Beck, A.; De Bucourt, M.; Schnorr, J. [Charite, Humboldt University, Department of Radiology (Germany); Bernhardt, U. [InnoRa GmbH (Germany); Gebauer, B.; Hamm, B.; Guenther, R. W. [Charite, Humboldt University, Department of Radiology (Germany)

2013-06-15

Purpose. To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation. Methods. Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served as a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury. Results. In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig. Conclusion. MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.

Transcutaneous cervical vagal nerve stimulation modulates cardiac vagal tone and tumor necrosis factor-alpha

DEFF Research Database (Denmark)

Brock, C; Brock, B; Aziz, Q

2017-01-01

-VNS, there was an increase in cardiac vagal tone and a reduction in tumor necrosis factor-α in comparison to baseline. No change was seen in blood pressure, cardiac sympathetic index or other cytokines. These preliminary data suggest that t-VNS exerts an autonomic and a subtle antitumor necrosis factor-α effect, which...

Communication between functional and denervated muscles using radiofrequency.

Science.gov (United States)

Jacob, Doreen K; Stefko, Susan Tonya; Hackworth, Steven A; Lovell, Michael R; Mickle, Marlin H

2006-05-01

This article focuses on establishing communication between a functional muscle and a denervated muscle using a radiofrequency communications link. The ultimate objective of the project is to restore the eye blink in patients with facial nerve paralysis. Two sets of experiments were conducted using the gastrocnemius leg muscles of Sprague-Dawley rats. In the initial tests, varying magnitudes of voltages ranging from 0.85 to 2.5 V were applied directly to a denervated muscle to determine the voltage required to produce visible contraction. The second set of experiments was then conducted to determine the voltage output from an in vivo muscle contraction that could be sensed and used to coordinate a signal for actuation of a muscle in a separate limb. After designing the appropriate external communication circuitry, a third experiment was performed to verify that a signal between a functional and a denervated muscle can be generated and used as a stimulus. Voltages below 2 V at a 10-millisecond pulse width elicited a gentle, controlled contraction of the denervated muscle in vivo. It was also observed that with longer pulse widths, higher stimulation voltages were required to produce sufficient contractions. It is possible to detect contraction of a muscle, use this to generate a signal to an external base station, and subsequently cause a separate, denervated muscle to contract in response to the signal. This demonstration in vivo of a signaling system for pacing of electrical stimulation of 1 muscle to spontaneous contraction of another, separate muscle, using radiofrequency communication without direct connection, may be used in numerous ways to overcome nerve damage.

Usefulness of muscle denervation as an MRI sign of peripheral nerve pathology

International Nuclear Information System (INIS)

Lisle, D. A.; Johnstone, S. A.

2007-01-01

Full text: Peripheral nerve disorders may be classified into compressive or entrapment neuropathies and non-compressive neuropathies. Muscle denervation recognized on MRI may be a useful sign in the diagnosis of peripheral nerve disorders. Acute or subacute denervation results in prolonged T 2 relaxation time, producing increased signal in skeletal muscle on short tau inversion-recovery and fat-suppressed T 2 -weighted images. Chronic denervation produces fatty atrophy of skeletal muscles, resulting in increased muscle signal on T 1 -weighted images. This review will outline and illustrate the various ways that muscle denervation as seen on MRI may assist in the diagnosis and localization of peripheral nerve disorders

Constitutive overexpression of muscarinic receptors leads to vagal hyperreactivity.

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Angelo Livolsi

Full Text Available BACKGROUND: Alterations in muscarinic receptor expression and acetylcholinesterase (AchE activity have been observed in tissues from Sudden Infant Death Syndrome (SIDS. Vagal overactivity has been proposed as a possible cause of SIDS as well as of vasovagal syncopes. The aim of the present study was to seek whether muscarinic receptor overexpression may be the underlying mechanism of vagal hyperreactivity. Rabbits with marked vagal pauses following injection of phenylephrine were selected and crossed to obtain a vagal hyperreactive strain. The density of cardiac muscarinic receptors and acetylcholinesterase (AchE gene expression were assessed. Blood markers of the observed cardiac abnormalities were also sought. METHODOLOGY/PRINCIPAL FINDINGS: Cardiac muscarinic M(2 and M(3 receptors were overexpressed in hyperreactive rabbits compared to control animals (2.3-fold and 2.5-fold, respectively and the severity of the phenylephrine-induced bradycardia was correlated with their densities. A similar overexpression of M(2 receptors was observed in peripheral mononuclear white blood cells, suggesting that cardiac M(2 receptor expression can be inferred with high confidence from measurements in blood cells. Sequencing of the coding fragment of the M(2 receptor gene revealed a single nucleotide mutation in 83% of hyperreactive animals, possibly contributing for the transcript overexpression. Significant increases in AchE expression and activity were also assessed (AchE mRNA amplification ratio of 3.6 versus normal rabbits. This phenomenon might represent a compensatory consequence of muscarinic receptors overexpression. Alterations in M(2 receptor and AchE expression occurred between the 5th and the 7th week of age, a critical period also characterized by a higher mortality rate of hyperreactive rabbits (52% in H rabbits versus 13% in normal rabbits and preceeded the appearance of functional disorders. CONCLUSIONS/SIGNIFICANCE: The results suggest that

Degradation rate of acetylcholine receptors inserted into denervated vertebrate neuromuscular junctions

International Nuclear Information System (INIS)

Shyng, S.L.; Salpeter, M.M.

1989-01-01

Many studies exist on the effect of denervation on the degradation of acetylcholine receptors (AChRs) at the vertebrate neuromuscular junction (nmj). These studies have described the behavior of either the total population of junctional receptors at different times after denervation, or of the receptors present at the time of denervation. No experimental studies yet exist on the degradation rate of the receptors newly inserted into denervated junctions. In the previous studies, the original receptors of mouse sternomastoid muscles were found to retain the slow degradation (t 1/2) of approximately 8-10 d of innervated junctional receptors for up to 10 d after denervation before accelerating to a t 1/2 of approximately 3 d. The total junctional receptors, on the other hand, showed a progressive increase in degradation rate from a t 1/2 of 8-10 d to a t 1/2 of 1 d. To reconcile these earlier observations, the present study examines the degradation of new receptors inserted into the nmj after denervation. To avoid possible contamination of the data with postdenervation extrajunctional receptors, we used transmission electron microscope autoradiography to study only receptors located at the postjunctional fold of the nmj. We established that the new receptors inserted into denervated junctions have a t 1/2 of approximately 1 d, considerably faster than that of the original receptors and equivalent to that of postdenervation extrajunctional receptors. Both original and new receptors are interspersed at the top of the junctional folds. Thus, until all the original receptors are degraded, the postjunctional membrane contains two populations of AChRs that maintain a total steady-state site density but degrade at different rates

Jugular and vagal paragangliomas: Systematic study of management with surgery and radiotherapy

NARCIS (Netherlands)

Suarez, C.; Rodrigo, J.P.; Bodeker, C.C.; Llorente, J.L.; Silver, C.E.; Jansen, J.C.; Takes, R.P.; Strojan, P.; Pellitteri, P.K.; Rinaldo, A.; Mendenhall, W.M.; Ferlito, A.

2013-01-01

BACKGROUND: The definitive treatment for head and neck paraganglioma (PG) is surgical excision. Unfortunately, surgery, particularly of vagal paraganglioma (VPG; "glomus vagale") and foramen jugulare ("glomus jugulare") tumors, may be complicated by injuries to the lower cranial nerves, a high price

Persistent muscle fiber regeneration in long term denervation. Past, present, future

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Ugo Carraro

2015-03-01

Full Text Available Despite the ravages of long term denervation there is structural and ultrastructural evidence for survival of muscle fibers in mammals, with some fibers surviving at least ten months in rodents and 3-6 years in humans. Further, in rodents there is evidence that muscle fibers may regenerate even after repeated damage in the absence of the nerve, and that this potential is maintained for several months after denervation. While in animal models permanently denervated muscle sooner or later loses the ability to contract, the muscles may maintain their size and ability to function if electrically stimulated soon after denervation. Whether in mammals, humans included, this is a result of persistent de novo formation of muscle fibers is an open issue we would like to explore in this review. During the past decade, we have studied muscle biopsies from the quadriceps muscle of Spinal Cord Injury (SCI patients suffering with Conus and Cauda Equina syndrome, a condition that fully and irreversibly disconnects skeletal muscle fibers from their damaged innervating motor neurons. We have demonstrated that human denervated muscle fibers survive years of denervation and can be rescued from severe atrophy by home-based Functional Electrical Stimulation (h-bFES. Using immunohistochemistry with both non-stimulated and the h-bFES stimulated human muscle biopsies, we have observed the persistent presence of muscle fibers which are positive to labeling by an antibody which specifically recognizes the embryonic myosin heavy chain (MHCemb. Relative to the total number of fibers present, only a small percentage of these MHCemb positive fibers are detected, suggesting that they are regenerating muscle fibers and not pre-existing myofibers re-expressing embryonic isoforms. Although embryonic isoforms of acetylcholine receptors are known to be re-expressed and to spread from the end-plate to the sarcolemma of muscle fibers in early phases of muscle denervation, we suggest

Renal Denervation to Modify Hypertension and the Heart Failure State.

Science.gov (United States)

Zhong, Ming; Kim, Luke K; Swaminathan, Rajesh V; Feldman, Dmitriy N

2017-07-01

Sympathetic overactivation of renal afferent and efferent nerves have been implicated in the development and maintenance of several cardiovascular disease states, including resistant hypertension and heart failure with both reduced and preserved systolic function. With the development of minimally invasive catheter-based techniques, percutaneous renal denervation has become a safe and effective method of attenuating sympathetic overactivation. Percutaneous renal denervation, therefore, has the potential to modify and treat hypertension and congestive heart failure. Although future randomized controlled studies are needed to definitively prove its efficacy, renal denervation has the potential to change the way we view and treat cardiovascular disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparative decline of the protein profiles of nebulin in response to denervation in skeletal muscle

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Wei, Jih-Hua [Department of Internal Medicine, Min-Sheng General Hospital, Taoyuan, Taiwan (China); Chang, Nen-Chung [Division of Cardiology, Department of Internal Medicine, College of Medicine, Taipei Medical University Hospital, Taipei, Taiwan (China); Chen, Sy-Ping [Department of Nursing, Chang Gung University of Science and Technology, Taoyuan, Taiwan (China); Geraldine, Pitchairaj [Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu (India); Jayakumar, Thanasekaran, E-mail: tjaya_2002@yahoo.co.in [Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Fong, Tsorng-Harn, E-mail: thfong@tmu.edu.tw [Department of Anatomy and Cell Biology, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)

2015-10-09

The sliding filament model of the sarcomere was developed more than half a century ago. This model, consisting only of thin and thick filaments, has been efficacious in elucidating many, but not all, features of skeletal muscle. Work during the 1980s revealed the existence of two additional filaments: the giant filamentous proteins titin and nebulin. Nebulin, a giant myofibrillar protein, acts as a protein ruler to maintain the lattice arrays of thin filaments and plays a role in signal transduction and contractile regulation. However, the change of nebulin and its effect on thin filaments in denervation-induced atrophic muscle remains unclear. The purpose of this study is to examine the content and pattern of nebulin, myosin heavy chain (MHC), actin, and titin in innervated and denervated tibialis anterior (TA) muscles of rats using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), densitometry and electron microscopic (EM) analyses. The results revealed that denervation induced muscle atrophy is accompanied by decreased nebulin content in a time-dependent manner. For instant, the levels of nebulin in denervated muscles were markedly (P < 0.05) decreased, about 24.6% and 40.2% in comparison with innervated muscle after denervation of 28 and 56 days, respectively. The nebulin/MHC, nebulin/actin, and nebulin/titin ratios were decreased, suggesting a concomitant reduction of nebulin in denervated muscle. Moreover, a western blotting assay proved that nebulin declined faster than titin on 28 and 56 days of denervated muscle. In addition, EM study revealed that the disturbed arrangements of myofilaments and a disorganized contractile apparatus were also observed in denervated muscle. Overall, the present study provides evidence that nebulin is more sensitive to the effect of denervation than MHC, actin, and titin. Nebulin decline indeed resulted in disintegrate of thin filaments and shortening of sarcomeres. - Highlights: • We successfully

Renal denervation decreases blood pressure and renal tyrosine hydroxylase but does not augment the effect of hypotensive drugs.

Science.gov (United States)

Skrzypecki, Janusz; Gawlak, Maciej; Huc, Tomasz; Szulczyk, Paweł; Ufnal, Marcin

2017-01-01

The effect of renal denervation on the efficacy of antihypertensive drugs has not yet been elucidated. Twenty-week-old spontaneously hypertensive rats were treated with metoprolol, losartan, indapamide, or saline (controls) and assigned to renal denervation or a sham procedure. Acute hemodynamic measurements were performed ten days later. Series showing a significant interaction between renal denervation and the drugs were repeated with chronic telemetry measurements. In the saline series, denervated rats showed a significantly lower mean arterial blood pressure (blood pressure) than the sham-operated rats. In contrast, in the metoprolol series denervated rats showed a significantly higher blood pressure than sham rats. There were no differences in blood pressure between denervated and sham rats in the losartan and indapamide series. In chronic studies, a 4-week treatment with metoprolol caused a decrease in blood pressure. Renal denervation and sham denervation performed 10 days after the onset of metoprolol treatment did not affect blood pressure. Denervated rats showed markedly reduced renal nerve tyrosine hydroxylase levels. In conclusion, renal denervation decreases blood pressure in hypertensive rats. The hypotensive action of metoprolol, indapamide, and losartan is not augmented by renal denervation, suggesting the absence of synergy between renal denervation and the drugs investigated in this study.

Vagal modulation of resting heart rate in rats: the role of stress, psychosocial factors and physical exercise

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Luca eCarnevali

2014-03-01

Full Text Available In humans, there are large individual differences in the levels of vagal modulation of resting heart rate. High levels are a recognized index of cardiac health, whereas low levels are considered an important risk factor for cardiovascular morbidity and mortality. Several factors are thought to contribute significantly to this inter-individual variability. While regular physical exercise seems to induce an increase in resting vagal tone, chronic life stress and psychosocial factors such as negative moods and personality traits appear associated with vagal withdrawal. Preclinical research has been attempting to clarify such relationships and to provide insights into the neurobiological mechanisms underlying vagal tone impairment/enhancement. This paper focuses on rat studies that have explored the effects of stress, psychosocial factors and physical exercise on vagal modulation of resting heart rate. Results are discussed with regard to: (i individual differences in resting vagal tone, cardiac stress reactivity and arrhythmia vulnerability; (ii elucidation of the neurobiological determinants of resting vagal tone.

Renal denervation

DEFF Research Database (Denmark)

Olsen, Lene Kjær; Kamper, Anne-Lise; Svendsen, Jesper Hastrup

2015-01-01

PURPOSE OF REVIEW: Renal denervation (RDN) has, within recent years, been suggested as a novel treatment option for patients with resistant hypertension. This review summarizes the current knowledge on this procedure as well as limitations and questions that remain to be answered. RECENT FINDINGS...... selection, anatomical and physiological effects of RDN as well as possible beneficial effects on other diseases with increased sympathetic activity. The long awaited Symplicity HTN-3 (2014) results illustrated that the RDN group and the sham-group had similar reductions in BP. SUMMARY: Initial studies...

Renal artery denervation for treating resistant hypertension : definition of the disease, patient selection and description of the procedure.

Science.gov (United States)

Volpe, Massimo; Rosei, Enrico Agabiti; Ambrosioni, Ettore; Cottone, Santina; Cuspidi, Cesare; Borghi, Claudio; De Luca, Nicola; Fallo, Francesco; Ferri, Claudio; Mancia, Giuseppe; Morganti, Alberto; Muiesan, Maria Lorenza; Sarzani, Riccardo; Sechi, Leonardo; Tocci, Giuliano; Virdis, Agostino

2012-12-01

Arterial hypertension is responsible for a significant burden of cardiovascular morbidity and mortality, worldwide. Although several rational and integrated pharmacological strategies are available, the control of high blood pressure still remains largely unsatisfactory. Failure to achieve effective blood pressure control in treated hypertensive patients may have a substantial impact on individual global cardiovascular risk, since it significantly increases the risk of developing hypertension-related macrovascular and microvascular complications. Arterial hypertension is arbitrarily defined as 'resistant' or 'refractory' when the recommended blood pressure goals (clinic blood pressure below 140/90 mmHg or below 130/80 mmHg in patients with type 2 diabetes mellitus or nephropathy) are not achieved in the presence of a therapeutic strategy that includes lifestyle changes and at least three classes of antihypertensive drugs, including a diuretic, at adequate doses. Recently, an innovative non-pharmacological option has become available for treating resistant hypertension. Sympathetic denervation of renal arteries is a minimally invasive procedure that is performed via percutaneous access from the femoral artery. It consists of radiofrequency ablation of the afferent and efferent nerves of the renal sympathetic nervous system, with consequent isolation of renal parenchymal and juxtaglomerular structures from abnormal stimulation of the efferent adrenergic system. The present position paper of the Italian Society of Hypertension (SIIA) offers a diagnostic and therapeutic approach for the proper identification and effective clinical management of patients with resistant hypertension, who are candidates for renal artery denervation. These indications may have important implications not only from a clinical point of view, but also from an economic point of view, since a proper identification of patients with true resistant hypertension and an accurate selection of patients

Does the presence of accessory renal arteries affect the efficacy of renal denervation?

Science.gov (United States)

Id, Dani; Kaltenbach, Benjamin; Bertog, Stefan C; Hornung, Marius; Hofmann, Ilona; Vaskelyte, Laura; Sievert, Horst

2013-10-01

This study sought to assess the efficacy of catheter-based renal sympathetic denervation in patients with accessory renal arteries and to compare the blood pressure (BP)-lowering effect with that observed in patients with bilateral single renal arteries after renal denervation. Catheter-based renal sympathetic denervation causes significant BP reductions in patients with resistant hypertension. Seventy-four patients were included in this study. Patients were assigned to 2 main groups: a bilateral single renal arteries group I (n = 54) and an accessory renal arteries group II (n = 20). Group II consisted of 9 patients whose accessory renal arteries were all denervated (group IIa), and 11 patients whose accessory renal arteries were not, or only incompletely, denervated (group IIb). The primary endpoint was the change in office systolic BP after 6 months. The procedure was successful in all patients. Group I: mean BP at baseline was 166.2/89.4 ± 20.5/14.6 mm Hg and decreased by -16.6 (p renal denervation in patients with accessory renal arteries is less pronounced than in patients with bilateral single renal arteries. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Dynamic changes in the mouse skeletal muscle proteome during denervation-induced atrophy

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Franziska Lang

2017-07-01

Full Text Available Loss of neuronal stimulation enhances protein breakdown and reduces protein synthesis, causing rapid loss of muscle mass. To elucidate the pathophysiological adaptations that occur in atrophying muscles, we used stable isotope labelling and mass spectrometry to quantify protein expression changes accurately during denervation-induced atrophy after sciatic nerve section in the mouse gastrocnemius muscle. Additionally, mice were fed a stable isotope labelling of amino acids in cell culture (SILAC diet containing 13C6-lysine for 4, 7 or 11 days to calculate relative levels of protein synthesis in denervated and control muscles. Ubiquitin remnant peptides (K-ε-GG were profiled by immunoaffinity enrichment to identify potential substrates of the ubiquitin-proteasomal pathway. Of the 4279 skeletal muscle proteins quantified, 850 were differentially expressed significantly within 2 weeks after denervation compared with control muscles. Moreover, pulse labelling identified Lys6 incorporation in 4786 proteins, of which 43 had differential Lys6 incorporation between control and denervated muscle. Enrichment of diglycine remnants identified 2100 endogenous ubiquitination sites and revealed a metabolic and myofibrillar protein diglycine signature, including myosin heavy chains, myomesins and titin, during denervation. Comparative analysis of these proteomic data sets with known atrogenes using a random forest approach identified 92 proteins subject to atrogene-like regulation that have not previously been associated directly with denervation-induced atrophy. Comparison of protein synthesis and proteomic data indicated that upregulation of specific proteins in response to denervation is mainly achieved by protein stabilization. This study provides the first integrated analysis of protein expression, synthesis and ubiquitin signatures during muscular atrophy in a living animal.

The effect of renal denervation in an experimental model of chronic renal insufficiency, The REmnant kidney Denervation In Pigs study (REDIP study

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Jean-Claude Lubanda

2017-10-01

Full Text Available Abstract Background Renal denervation (RDN is a promising therapeutic method in cardiology. Its currently most investigated indication is resistant hypertension. Other potential indications are atrial fibrillation, type 2 diabetes mellitus and chronic renal insufficiency among others. Previous trials showed conflicting but promising results, but the real benefits of RDN are still under investigation. Patients with renal insufficiency and resistant hypertension are proposed to be a good target for this therapy due to excessive activation of renal sympathetic drive. However, only limited number of studies showed benefits for these patients. We hypothesize that in our experimental model of chronic kidney disease (CKD due to ischemia with increased activity of the renin–angiotensin–aldosterone system (RAAS, renal denervation can have protective effects by slowing or blocking the progression of renal injury. Methods An experimental biomodel of chronic renal insufficiency induced by ischemia was developed using selective renal artery embolization (remnant kidney porcine model. 27 biomodels were assessed. Renal denervation was performed in 19 biomodels (denervated group, and the remaining were used as controls (n = 8. The extent of renal injury and reparative process between the two groups were compared and assessed using biochemical parameters and histological findings. Results Viable remnant kidney biomodels were achieved and maintained in 27 swine. There were no significant differences in biochemical parameters between the two groups at baseline. Histological assessment proved successful RDN procedure in all biomodels in the denervated group. Over the 7-week period, there were significant increases in serum urea, creatinine, and aldosterone concentration in both groups. The difference in urea and creatinine levels were not statistically significant between the two groups. However, the level of aldosterone in the denervated was significantly

Renal denervation for refractory hypertension. Technical aspects, complications and radiation exposure

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Scheurig-Muenkler, C.; Kroencke, T.J.; Powerski, M.J. [Charite Universitatesmedizin, Berlin (Germany). Radiologie; Weiss, W.; Toelle, M.; Giet, M. van der; Zidek, W. [Charite Universitatesmedizin, Berlin (Germany). Nephrologie; Foert, E. [DRK Klinikum Berlin Mitte, Berlin (Germany). Radiologie

2013-06-15

Purpose: To analyze procedural details, complications and radiation exposure in renal denervation (RDN) using the Medtronic Symplicity {sup registered} device in the treatment of refractory hypertension. Materials and Methods: Fifty three consecutive patients underwent RDN. The number of ablations per artery, peri-procedural complications, procedure time (PT), fluoroscopy time (FT), dose-area product (DAP) and procedure-related complications were documented. Additionally, the radiation dose was compared between obese (body mass index {>=} 30 kg/m{sup 2}) and non-obese patients. Results: Bilateral RDN was performed in 50/53 (94 %) cases and with a minimum of 4 ablations per artery in 33/50 (66 %), the mean count being 5.4 (range R: 2 - 13) on the right and 4.3 (R: 1 - 10) on the left. The FT and DAP decreased significantly over the first 12 procedures, reaching a steady state with a median FT of 11.2 min (R: 7.5 - 27) and a median DAP of 4796 cGy x cm{sup 2} (R: 1076 - 21 371), resulting in an effective dose of 15.7 mSv. The median PT was 57 min (R: 40 - 70). Obese patients had a 3.3-fold higher radiation dose (p < 0.001). We observed one severe spasm and one imminent respiratory depression, both resolved without sequelae. Conclusion: For an experienced interventionalist, RDN has a short learning curve with a low risk profile. The radiation dose does not exceed that of other renal artery interventions, but is explicitly higher in obese patients, who account for a large portion of patients with refractory hypertension. (orig.)

Diffusion-weighted MRI of denervated muscle: a clinical and experimental study

International Nuclear Information System (INIS)

Holl, Nathalie; Bierry, Guillaume; Moser, Thomas; Dietemann, Jean-Louis; Kremer, Stephane; Echaniz-Laguna, Andoni; Mohr, Michel; Loeffler, Jean-Philippe

2008-01-01

The aim of this study was to investigate skeletal muscle denervation using diffusion-weighted magnetic resonance imaging (DWMRI). Sciatic nerve axotomy was performed in a group of nine New Zealand White rabbits, and electromyographic (EMG), pathological, and DWMRI studies were conducted on ipsilateral hamstring muscles 1 and 8 days after axotomy. In addition, DWMRI studies were carried out on leg muscles of ten patients with acute and subacute lumbosacral radiculopathy. High intensity signals on short tau inversion recovery (STIR) magnetic resonance imaging and an increased apparent diffusion coefficient (ADC) were observed in denervated muscles of the animals 1 and 8 days after axotomy as well as in denervated muscles of the patients with radiculopathy. In the clinical study, ADC was 1.26±0.18 x 10 -9 m 2 /s in normal muscle and increased to 1.56±0.23 x 10 -9 m 2 /s in denervated muscles (p =0.0016). In animals, EMG and muscle pathological studies were normal 1 day after axotomy, and the muscles demonstrated spontaneous activity on EMG and neurogenic atrophy on histological studies 7 days later. This DWMRI study demonstrates that enlargement of extracellular fluid space in muscle denervation is an early phenomenon occurring several days before the appearance of EMG and histological abnormalities. (orig.)

Parental Socialization, Vagal Regulation, and Preschoolers' Anxious Difficulties: Direct Mothers and Moderated Fathers

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Hastings, Paul D.; Sullivan, Caroline; McShane, Kelly E.; Coplan, Robert J.; Utendale, William T.; Vyncke, Johanna D.

2008-01-01

Parental supportiveness and protective overcontrol and preschoolers' parasympathetic regulation were examined as predictors of temperamental inhibition, social wariness, and internalizing problems. Lower baseline vagal tone and weaker vagal suppression were expected to mark poorer dispositional self-regulatory capacity, leaving children more…

[Renal denervation as treatment option for hypertension].

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Blankestijn, P J; Bots, M L

2016-01-01

The rationale behind catheter-based renal denervation is that afferent and efferent renal nerves play a role in the pathogenesis and maintenance of high blood pressure, and that this can be prevented by blocking the function of the renal nerves. Since the introduction of catheter-based renal denervation, several observational and a small number of randomised controlled trials have been conducted. The available evidence does not allow for a definitive conclusion regarding its efficacy. There have been no serious side-effects reported. The development of this treatment concept has not been finalised; new trials have just commenced or will start in the near future.

Exacerbation of electrical storm subsequent to implantation of a right vagal stimulator.

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Shalaby, Alaa A; El-Saed, Aiman; Nemec, Jan; Moossy, John J; Balzer, Jeffrey R

2007-12-01

A patient with advanced ischemic cardiomyopathy underwent implantation of a vagal stimulator in an attempt to control recurrent drug refractory ventricular arrhythmia. Electrical storm was exacerbated after the implant and continued after neurostimulation was discontinued. The report aims to provide a cautionary note to application of vagal stimulation for control of cardiac arrhythmia.

Diagnostic signs of motor neuropathy in MR neurography: Nerve lesions and muscle denervation

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Schwarz, Daniel; Pham, Mirko; Bendszus, Martin; Baeumer, Philipp; Weiler, Markus; Heiland, Sabine

2015-01-01

To investigate the diagnostic contribution of T2-w nerve lesions and of muscle denervation in peripheral motor neuropathies by magnetic resonance neurography (MRN). Fifty-one patients with peripheral motor neuropathies underwent high-resolution MRN by large coverage axial T2-w sequences of the upper arm, elbow, and forearm. Images were evaluated by two blinded readers for T2-w signal alterations of median, ulnar, and radial nerves, and for denervation in respective target muscle groups. All 51 patients displayed nerve lesions in at least one of three nerves, and 43 out of 51 patients showed denervation in at least one target muscle group of these nerves. In 21 out of 51 patients, the number of affected nerves matched the number of affected target muscle groups. In the remaining 30 patients, T2-w lesions were encountered more frequently than target muscle group denervation. In 153 nerve-muscle pairs, 72 showed denervation, but only one had increased muscle signal without a lesion in the corresponding nerve. MRN-based diagnosis of peripheral motor neuropathies is more likely by visualization of peripheral nerve lesions than by denervation in corresponding target muscles. Increased muscular T2-w signal without concomitant nerve lesions should raise suspicion of an etiology other than peripheral neuropathy. (orig.)

Diagnostic signs of motor neuropathy in MR neurography: Nerve lesions and muscle denervation

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Schwarz, Daniel; Pham, Mirko; Bendszus, Martin; Baeumer, Philipp [Heidelberg University Hospital, Department of Neuroradiology, Heidelberg (Germany); Weiler, Markus [Heidelberg University Hospital, Department of Neurology, Heidelberg (Germany); German Cancer Research Center (DKFZ), Clinical Cooperation Unit Neurooncology, Heidelberg (Germany); Heiland, Sabine [Heidelberg University Hospital, Section of Experimental Radiology, Department of Neuroradiology, Heidelberg (Germany)

2015-05-01

To investigate the diagnostic contribution of T2-w nerve lesions and of muscle denervation in peripheral motor neuropathies by magnetic resonance neurography (MRN). Fifty-one patients with peripheral motor neuropathies underwent high-resolution MRN by large coverage axial T2-w sequences of the upper arm, elbow, and forearm. Images were evaluated by two blinded readers for T2-w signal alterations of median, ulnar, and radial nerves, and for denervation in respective target muscle groups. All 51 patients displayed nerve lesions in at least one of three nerves, and 43 out of 51 patients showed denervation in at least one target muscle group of these nerves. In 21 out of 51 patients, the number of affected nerves matched the number of affected target muscle groups. In the remaining 30 patients, T2-w lesions were encountered more frequently than target muscle group denervation. In 153 nerve-muscle pairs, 72 showed denervation, but only one had increased muscle signal without a lesion in the corresponding nerve. MRN-based diagnosis of peripheral motor neuropathies is more likely by visualization of peripheral nerve lesions than by denervation in corresponding target muscles. Increased muscular T2-w signal without concomitant nerve lesions should raise suspicion of an etiology other than peripheral neuropathy. (orig.)

Central vagal sensory and motor connections: human embryonic and fetal development.

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Cheng, Gang; Zhou, Xiangtian; Qu, Jia; Ashwell, Ken W S; Paxinos, G

2004-07-30

The embryonic and fetal development of the nuclear components and pathways of vagal sensorimotor circuits in the human has been studied using Nissl staining and carbocyanine dye tracing techniques. Eight fetal brains ranging from 8 to 28 weeks of development had DiI (1,1'-dioctadecyl-3,3,3',3' tetramethylindocarbocyanine perchlorate) inserted into either the thoracic vagus nerve at the level of the sternal angle (two specimens of 8 and 9 weeks of gestation) or into vagal rootlets at the surface of the medulla (at all other ages), while a further five were used for study of cytoarchitectural development. The first central labeling resulting from peripheral application of DiI to the thoracic vagus nerve was seen at 8 weeks. By 9 weeks, labeled bipolar cells at the ventricular surface around the sulcus limitans (sl) were seen after DiI application to the thoracic vagus nerve. Subnuclear organization as revealed by both Nissl staining and carbocyanine dye tracing was found to be advanced at a relatively early fetal age, with afferent segregation in the medial Sol apparent at 13 weeks and subnuclear organization of efferent magnocellular divisions of dorsal motor nucleus of vagus nerve noticeable at the same stage. The results of the present study also confirm that vagal afferents are distributed to the dorsomedial subnuclei of the human nucleus of the solitary tract, with particular concentrations of afferent axons in the gelatinosus subnucleus. These vagal afferents appeared to have a restricted zone of termination from quite early in development (13 weeks) suggesting that there is no initial exuberance in the termination field of vagal afferents in the developing human nucleus of the solitary tract. On the other hand, the first suggestion of afferents invading 10N from the medial Sol was not seen until 20 weeks and was not well developed until 24 weeks, suggesting that direct monosynaptic connections between the sensory and effector components of the vagal

Interaction of thyroid state and denervation on skeletal myosin heavy chain expression

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Haddad, F.; Arnold, C.; Zeng, M.; Baldwin, K.

1997-01-01

The goal of this study was to examine the effects of altered thyroid state and denervation (Den) on skeletal myosin heavy chain (MHC) expression in the plantaris and soleus muscles. Rats were subjected to unilateral denervation (Den) and randomly assigned to one of three groups: (1) euthyroid; (2) hyperthyroid; (3) and hypothyroid. Denervation caused severe muscle atrophy and muscle-type specific MHC transformation. Denervation transformed the soleus to a faster muscle, and its effects required the presence of circulating thyroid hormone. In contrast, denervation transformed the plantaris to a slower muscle independently of thyroid state. Furthermore, thyroid hormone effects did not depend upon innervation status in the soleus, while they required the presence of the nerve in the plantaris. Collectively, these findings suggest that both thyroid hormone and intact nerve (a) differentially affect MHC transformations in fast and slow muscle; and (b) are important factors in regulating the optimal expression of both type I and IIB MHC genes. This research suggests that for patients with nerve damage and/or paralysis, both muscle mass and biochemical properties can also be affected by the thyroid state.

Profiling of G protein-coupled receptors in vagal afferents reveals novel gut-to-brain sensing mechanisms.

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Egerod, Kristoffer L; Petersen, Natalia; Timshel, Pascal N; Rekling, Jens C; Wang, Yibing; Liu, Qinghua; Schwartz, Thue W; Gautron, Laurent

2018-06-01

G protein-coupled receptors (GPCRs) act as transmembrane molecular sensors of neurotransmitters, hormones, nutrients, and metabolites. Because unmyelinated vagal afferents richly innervate the gastrointestinal mucosa, gut-derived molecules may directly modulate the activity of vagal afferents through GPCRs. However, the types of GPCRs expressed in vagal afferents are largely unknown. Here, we determined the expression profile of all GPCRs expressed in vagal afferents of the mouse, with a special emphasis on those innervating the gastrointestinal tract. Using a combination of high-throughput quantitative PCR, RNA sequencing, and in situ hybridization, we systematically quantified GPCRs expressed in vagal unmyelinated Na v 1.8-expressing afferents. GPCRs for gut hormones that were the most enriched in Na v 1.8-expressing vagal unmyelinated afferents included NTSR1, NPY2R, CCK1R, and to a lesser extent, GLP1R, but not GHSR and GIPR. Interestingly, both GLP1R and NPY2R were coexpressed with CCK1R. In contrast, NTSR1 was coexpressed with GPR65, a marker preferentially enriched in intestinal mucosal afferents. Only few microbiome-derived metabolite sensors such as GPR35 and, to a lesser extent, GPR119 and CaSR were identified in the Na v 1.8-expressing vagal afferents. GPCRs involved in lipid sensing and inflammation (e.g. CB1R, CYSLTR2, PTGER4), and neurotransmitters signaling (CHRM4, DRD2, CRHR2) were also highly enriched in Na v 1.8-expressing neurons. Finally, we identified 21 orphan GPCRs with unknown functions in vagal afferents. Overall, this study provides a comprehensive description of GPCR-dependent sensing mechanisms in vagal afferents, including novel coexpression patterns, and conceivably coaction of key receptors for gut-derived molecules involved in gut-brain communication. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Renal denervation for resistant hypertension: yes.

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Boschetti, Enrico; Alrashdi, Yahya; Schillaci, Giuseppe

2016-06-01

Sympathetic overactivity may have a role in triggering and maintaining resistant hypertension, and catheter-based renal denervation (RDN) has emerged as a promising treatment in refractory hypertension. Recently, the results of the Symplicity HTN-3, the first randomized, sham-controlled trial, failed to confirm the previously reported BP-lowering effects of RDN, although definitive conclusions cannot be drawn due to a number of study limitations. Consequently, although some centers halted their RDN programs, research continues and both the concept of denervation and treatment strategies are being redefined. A new generation of sham-controlled trials is currently underway with the aim of detecting which patients are expected to achieve the most beneficial effect from RDN. In this article, we examine the current data on RDN and discuss some insights and future opportunities.

The antiarrhythmic effect of vagal stimulation after acute coronary occlusion: Role of the heart rate.

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Manati, Waheed; Pineau, Julien; Doñate Puertas, Rosa; Morel, Elodie; Quadiri, Timour; Bui-Xuan, Bernard; Chevalier, Philippe

2018-01-03

Strong evidence suggests a causal link between autonomic disturbances and ventricular arrhythmias. However, the mechanisms underlying the antiarrhythmic effect of vagal stimulation are poorly understood. The vagal antiarrhythmic effect might be modulated by a decrease in heart rate. the proximal anterior interventricular artery was occluded in 16 pigs by clamping under general anaesthesia. Group 1: heart rates remained spontaneous (n = 6; 12 occlusions); Group 2: heart rates were fixed at 190 beats per minute (bpm) with atrial electrical stimulation (n = 10; 20 occlusions). Each pig received two occlusions, 30 min apart, one without and one with vagal stimulation (10 Hz, 2 ms, 5-20 mA). The antiarrhythmic effect of vagal activation was defined as the time to the appearance of ventricular fibrillation (VF) after occlusion. In Group 1, vagal stimulation triggered a significant decrease in basal heart rate (132 ± 4 vs. 110 ± 17 bpm, p coronary occlusion (1102 ± 85 vs. 925 ± 41 s, p acute coronary occlusion.

Parasympathetic denervation increases responses to VIP in isolated rat parotid acini

International Nuclear Information System (INIS)

McMillian, M.K.; Talamo, B.R.

1989-01-01

Vasoactive intestinal peptide (VIP) is a putative neurotransmitter found in the salivary glands of many species, including the rat parotid gland. Parasympathetic denervation has been reported to deplete VIP in the rat parotid gland and to lead to supersensitivity to this peptide in vivo. We have compared the effects of VIP on acini isolated from parasympathetically denervated and unoperated parotid glands to examine possible supersensitivity to the peptide in vitro. VIP normally produced responses similar to those obtained with a low concentration of the beta adrenergic agonist isoproterenol (ISO), but strikingly different from the effects obtained with the muscarinic agonist carbachol (CARB). In parotid membrane preparations, VIP stimulated adenylate cyclase activity. Dissociated acini treated with VIP showed increases in cAMP accumulation and amylase release which were potentiated by forskolin and also by inhibition of phosphodiesterase. After parasympathetic denervation, maximal effects of VIP on adenylate cyclase, cAMP accumulation and amylase release in intact cells were increased two- to five-fold over contralateral control (or unoperated) parotid responses. The increase in adenylate cyclase-mediated responses after denervation was specific to VIP; there was no increased response nor increased sensitivity of any of these responses to ISO. Specific [125I]VIP binding to parotid acini increased two-fold per gland and three-fold per mg of protein after denervation; this probably explains the observed increases in the response to VIP

VERSATILE, HIGH-RESOLUTION ANTEROGRADE LABELING OF VAGAL EFFERENT PROJECTIONS WITH DEXTRAN AMINES

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Walter, Gary C.; Phillips, Robert J.; Baronowsky, Elizabeth A.; Powley, Terry L.

2009-01-01

None of the anterograde tracers used to label and investigate vagal preganglionic neurons projecting to the viscera has proved optimal for routine and extensive labeling of autonomic terminal fields. To identify an alternative tracer protocol, the present experiment evaluated whether dextran conjugates, which have produced superior results in the CNS, might yield widespread and effective labeling of long, fine-caliber vagal efferents in the peripheral nervous system. The dextran conjugates that were evaluated proved reliable and versatile for labeling the motor neuron pool in its entirety, for single- and multiple-labeling protocols, for both conventional and confocal fluorescence microscopy, and for permanent labeling protocols for brightfield microscopy of the projections to the gastrointestinal (GI) tract. Using a standard ABC kit followed by visualization with DAB as the chromagen, Golgi-like labeling of the vagal efferent terminal fields in the GI wall was achieved with the biotinylated dextrans. The definition of individual terminal varicosities was so sharp and detailed that it was routinely practical to examine the relationship of putative vagal efferent contacts (by the criteria of high magnification light microscopy) with the dendritic and somatic architecture of counterstained neurons in the myenteric plexus. Overall, dextran conjugates provide high-definition labeling of an extensive vagal motor pool in the GI tract, and offer considerable versatility when multiple-staining protocols are needed to elucidate the complexities of the innervation of the gut. PMID:19056424

Denervation of pulmonary artery during mitral valve surgery in patients with high pulmonary hypertension

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А. В. Богачев-Прокофьев

2016-01-01

Full Text Available Objective. Pulmonary hypertension impairs the mitral valve and often leads to more severe symptoms of heart failure, low exercise tolerance and thus higher rates of morbidity and mortality. The purpose of this study is to evaluate the safety and efficacy of simultaneous radiofrequency ablation of ganglionated plexi of the pulmonary artery in patients with high pulmonary hypertension during mitral valve surgery.Methods. The inclusion criteria were based on patients’ echocardiography/right heart catheterization data. The main criteria were mean pulmonary artery pressure ≥40 mm Hg at rest and a positive reactive test with nitric oxide inhalation. From January 2014 to May 2015, 14 patients underwent radiofrequency denervation of the pulmonary artery in addition to planned mitral valve surgery. Mean patient age was 53.4±7.8 years, with 57.1% of patients being females.Results. Mean cardiopulmonary bypass time was 116±12 minutes, mean cross-clamp time was 95±13 minutes, and mean ablation time amounted to 9.5±3.1 minutes. Pulmonary artery pressure decreased significantly from a mean of 56.5±9.8 mmHg to 32.0±7.3 mmHg immediately after the operation (p<0.001, and to 28.4±5.2 mmHg and 29.7±4.4 mmHg on the first and third days at ICU respectively. Mean ICU stay was 3.1±1.2 days. There were neither early deaths nor specific complications.Conclusions. Simultaneous radiofrequency ablation of pulmonary artery ganglionated plexi when performing mitral valve surgery in patients with pulmonary hypertension is a safe and effective procedure. Further research and long-term follow-up would help to determine whether a decrease in the mean pressure of the pulmonary artery can be interpreted as a clinical advantage.

Vagal activity is quadratically related to prosocial traits, prosocial emotions, and observer perceptions of prosociality.

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Kogan, Aleksandr; Oveis, Christopher; Carr, Evan W; Gruber, June; Mauss, Iris B; Shallcross, Amanda; Impett, Emily A; van der Lowe, Ilmo; Hui, Bryant; Cheng, Cecilia; Keltner, Dacher

2014-12-01

In the present article, we introduce the quadratic vagal activity-prosociality hypothesis, a theoretical framework for understanding the vagus nerve's involvement in prosociality. We argue that vagus nerve activity supports prosocial behavior by regulating physiological systems that enable emotional expression, empathy for others' mental and emotional states, the regulation of one's own distress, and the experience of positive emotions. However, we contend that extremely high levels of vagal activity can be detrimental to prosociality. We present 3 studies providing support for our model, finding consistent evidence of a quadratic relationship between respiratory sinus arrhythmia--the degree to which the vagus nerve modulates the heart rate--and prosociality. Individual differences in vagal activity were quadratically related to prosocial traits (Study 1), prosocial emotions (Study 2), and outside ratings of prosociality by complete strangers (Study 3). Thus, too much or too little vagal activity appears to be detrimental to prosociality. The present article provides the 1st theoretical and empirical account of the nonlinear relationship between vagal activity and prosociality.

Renal denervation in a patient with Alport syndrome and rejected renal allograft

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Narayana Raju

2015-12-01

Full Text Available Renal denervation is a new intervention to treat resistant hypertension. By applying radiofrequency (RF to renal arteries, sympathetic nerves in adventitia layer of vascular wall can be denervated. Sympathetic hyperactivity is an important contributory factor in hypertension of hemodialysis patients. Hyperactive sympathetic nervous system aggravates hypertension and it can cause complications like left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. Our report illustrates the use of renal denervation using conventional RF catheter for uncontrolled hypertension in a patient with Alport syndrome and rejected renal allograft. Progressive and sustained reduction of blood pressure was obtained post-procedure and at 24 months follow-up with antihypertensives decreased from 6 to 2 per day, thereby demonstrating the safety, feasibility, and efficacy of the procedure. There are some reports available on the usefulness of this technique in hemodialysis patients; however, there are no studies of renal denervation in patients with Alport syndrome and failed allograft situation.

Renal denervation in a patient with Alport syndrome and rejected renal allograft.

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Raju, Narayana; Lloyd, Vincent; Yalagudri, Sachin; Das, Bharati; Ravikishore, A G

2015-12-01

Renal denervation is a new intervention to treat resistant hypertension. By applying radiofrequency (RF) to renal arteries, sympathetic nerves in adventitia layer of vascular wall can be denervated. Sympathetic hyperactivity is an important contributory factor in hypertension of hemodialysis patients. Hyperactive sympathetic nervous system aggravates hypertension and it can cause complications like left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. Our report illustrates the use of renal denervation using conventional RF catheter for uncontrolled hypertension in a patient with Alport syndrome and rejected renal allograft. Progressive and sustained reduction of blood pressure was obtained post-procedure and at 24 months follow-up with antihypertensives decreased from 6 to 2 per day, thereby demonstrating the safety, feasibility, and efficacy of the procedure. There are some reports available on the usefulness of this technique in hemodialysis patients; however, there are no studies of renal denervation in patients with Alport syndrome and failed allograft situation. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Circumferential targeted renal sympathetic nerve denervation with preservation of the renal arterial wall using intra-luminal ultrasound

Science.gov (United States)

Roth, Austin; Coleman, Leslie; Sakakura, Kenichi; Ladich, Elena; Virmani, Renu

2015-03-01

An intra-luminal ultrasound catheter system (ReCor Medical's Paradise System) has been developed to provide circumferential denervation of the renal sympathetic nerves, while preserving the renal arterial intimal and medial layers, in order to treat hypertension. The Paradise System features a cylindrical non-focused ultrasound transducer centered within a balloon that circulates cooling fluid and that outputs a uniform circumferential energy pattern designed to ablate tissues located 1-6 mm from the arterial wall and protect tissues within 1 mm. RF power and cooling flow rate are controlled by the Paradise Generator which can energize transducers in the 8.5-9.5 MHz frequency range. Computer simulations and tissue-mimicking phantom models were used to develop the proper power, cooling flow rate and sonication duration settings to provide consistent tissue ablation for renal arteries ranging from 5-8 mm in diameter. The modulation of these three parameters allows for control over the near-field (border of lesion closest to arterial wall) and far-field (border of lesion farthest from arterial wall, consisting of the adventitial and peri-adventitial spaces) depths of the tissue lesion formed by the absorption of ultrasonic energy and conduction of heat. Porcine studies have confirmed the safety (protected intimal and medial layers) and effectiveness (ablation of 1-6 mm region) of the system and provided near-field and far-field depth data to correlate with bench and computer simulation models. The safety and effectiveness of the Paradise System, developed through computer model, bench and in vivo studies, has been demonstrated in human clinical studies.

Evaluation of cardiac denervation in patients with long-standing diabetes

International Nuclear Information System (INIS)

Khurram, M.; Khar, Hamama-tul-Bushra; Malik, M.F. Fazal-ur-Rehman; Javed, S.; Hassan, Z.; Minhas, Z.; Goraya, M.F.; Shakoor, A.

2002-01-01

Objective: Evaluation of cardiac autonomic dysfunction in long-standing diabetics, comparing patients treated with insulin and oral hypo glycemic agents. Design: Observational and comparative study between two treatment groups. Place and Duration of Study: At department of Medicine, Pakistan Institute of Medical Sciences, Islamabad, for 6 months. Subjects and Methods: Fifty diabetic patients of about 10 years illness were studied. Patients were divided into two groups, Group 1(13 males, 12 females; mean age 33.08 years) included those who received insulin, and Group II patients (12 males, 13 females; mean age 54.68 years) who received oral hypo glycemic agents for their diabetic illness. Evaluation of cardiac denervation in both the groups was done in terms of presence of resting tachycardia, loss of sinus arrhythmia and abnormalities of Valsava response. Results: At least some form of cardiac denervation was present in 62% of total subjects. 48% of Group I and 76 % of Group II patients. A significantly high number of patients treated with oral hypo glycemic agents had evidence of cardiac denervation when compared with patients who were treated with insulin (p < 0.05). Conclusion: Cardiac denervation is common in long-standing diabetics specifically in those treated with oral hypo glycemic agents. (author)

TRPV1 Channels and Gastric Vagal Afferent Signalling in Lean and High Fat Diet Induced Obese Mice.

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Stephen J Kentish

Full Text Available Within the gastrointestinal tract vagal afferents play a role in control of food intake and satiety signalling. Activation of mechanosensitive gastric vagal afferents induces satiety. However, gastric vagal afferent responses to mechanical stretch are reduced in high fat diet mice. Transient receptor potential vanilloid 1 channels (TRPV1 are expressed in vagal afferents and knockout of TRPV1 reduces gastro-oesophageal vagal afferent responses to stretch. We aimed to determine the role of TRPV1 on gastric vagal afferent mechanosensitivity and food intake in lean and HFD-induced obese mice.TRPV1+/+ and -/- mice were fed either a standard laboratory diet or high fat diet for 20wks. Gastric emptying of a solid meal and gastric vagal afferent mechanosensitivity was determined.Gastric emptying was delayed in high fat diet mice but there was no difference between TRPV1+/+ and -/- mice on either diet. TRPV1 mRNA expression in whole nodose ganglia of TRPV1+/+ mice was similar in both dietary groups. The TRPV1 agonist N-oleoyldopamine potentiated the response of tension receptors in standard laboratory diet but not high fat diet mice. Food intake was greater in the standard laboratory diet TRPV1-/- compared to TRPV1+/+ mice. This was associated with reduced response of tension receptors to stretch in standard laboratory diet TRPV1-/- mice. Tension receptor responses to stretch were decreased in high fat diet compared to standard laboratory diet TRPV1+/+ mice; an effect not observed in TRPV1-/- mice. Disruption of TRPV1 had no effect on the response of mucosal receptors to mucosal stroking in mice on either diet.TRPV1 channels selectively modulate gastric vagal afferent tension receptor mechanosensitivity and may mediate the reduction in gastric vagal afferent mechanosensitivity in high fat diet-induced obesity.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: cellular organization and neurotransmitters.

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Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E

2009-09-20

The sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca(++)-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (+/-)-alpha-amino-3-hydroxy- 5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish Cellular organization and neurotransmitters

Science.gov (United States)

Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E.

2009-01-01

The sense of taste is crucial in an animal’s determination as to what is edible and what is not. This gustatory function is especially important in goldfish who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons which have radially-directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)-α-amino-3-hydroxy-5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediates neurotransmission between reflex interneurons and vagal motoneurons. Thus the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. PMID:19598285

Beneficial Effects of Renal Denervation on Pulmonary Vascular Remodeling in Experimental Pulmonary Artery Hypertension.

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Qingyan, Zhao; Xuejun, Jiang; Yanhong, Tang; Zixuan, Dai; Xiaozhan, Wang; Xule, Wang; Zongwen, Guo; Wei, Hu; Shengbo, Yu; Congxin, Huang

2015-07-01

Activation of both the sympathetic nervous system and the renin-angiotensin-aldosterone system is closely associated with pulmonary arterial hypertension. We hypothesized that renal denervation decreases renin-angiotensin-aldosterone activity and inhibits the progression of pulmonary arterial hypertension. Twenty-two beagles were randomized into 3 groups. The dogs' pulmonary dynamics were measured before and 8 weeks after injection of 0.1mL/kg dimethylformamide (control dogs) or 2mg/kg dehydromonocrotaline (pulmonary arterial hypertension and pulmonary arterial hypertension + renal denervation dogs). Eight weeks after injection, neurohormone levels and pulmonary tissue morphology were measured. Levels of plasma angiotensin II and endothelin-1 were significantly increased after 8 weeks in the pulmonary arterial hypertension dogs and were higher in the lung tissues of these dogs than in those of the control and renal denervation dogs (mean [standard deviation] angiotensin II: 65 [9.8] vs 38 [6.7], 46 [8.1]; endothelin-1: 96 [10.3] vs 54 [6.2], 67 [9.4]; P < .01). Dehydromonocrotaline increased the mean pulmonary arterial pressure (16 [3.4] mmHg vs 33 [7.3] mmHg; P < .01), and renal denervation prevented this increase. Pulmonary smooth muscle cell proliferation was higher in the pulmonary arterial hypertension dogs than in the control and pulmonary arterial hypertension + renal denervation dogs. Renal denervation attenuates pulmonary vascular remodeling and decreases pulmonary arterial pressure in experimental pulmonary arterial hypertension. The effect of renal denervation may contribute to decreased neurohormone levels. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Denervation in murine fast-twitch muscle: short-term physiological changes and temporal expression profiling.

Science.gov (United States)

Raffaello, Anna; Laveder, Paolo; Romualdi, Chiara; Bean, Camilla; Toniolo, Luana; Germinario, Elena; Megighian, Aram; Danieli-Betto, Daniela; Reggiani, Carlo; Lanfranchi, Gerolamo

2006-03-13

Denervation deeply affects muscle structure and function, the alterations being different in slow and fast muscles. Because the effects of denervation on fast muscles are still controversial, and high-throughput studies on gene expression in denervated muscles are lacking, we studied gene expression during atrophy progression following denervation in mouse tibialis anterior (TA). The sciatic nerve was cut close to trochanter in adult CD1 mice. One, three, seven, and fourteen days after denervation, animals were killed and TA muscles were dissected out and utilized for physiological experiments and gene expression studies. Target cDNAs from TA muscles were hybridized on a dedicated cDNA microarray of muscle genes. Seventy-one genes were found differentially expressed. Microarray results were validated, and the expression of relevant genes not probed on our array was monitored by real-time quantitative PCR (RQ-PCR). Nuclear- and mitochondrial-encoded genes implicated in energy metabolism were consistently downregulated. Among genes implicated in muscle contraction (myofibrillar and sarcoplasmic reticulum), genes typical of fast fibers were downregulated, whereas those typical of slow fibers were upregulated. Electrophoresis and Western blot showed less pronounced changes in myofibrillar protein expression, partially confirming changes in gene expression. Isometric tension of skinned fibers was little affected by denervation, whereas calcium sensitivity decreased. Functional studies in mouse extensor digitorum longus muscle showed prolongation in twitch time parameters and shift to the left in force-frequency curves after denervation. We conclude that, if studied at the mRNA level, fast muscles appear not less responsive than slow muscles to the interruption of neural stimulation.

Externally Delivered Focused Ultrasound for Renal Denervation.

Science.gov (United States)

Neuzil, Petr; Ormiston, John; Brinton, Todd J; Starek, Zdenek; Esler, Murray; Dawood, Omar; Anderson, Thomas L; Gertner, Michael; Whitbourne, Rob; Schmieder, Roland E

2016-06-27

The aim of this study was to assess clinical safety and efficacy outcomes of renal denervation executed by an externally delivered, completely noninvasive focused therapeutic ultrasound device. Renal denervation has emerged as a potential treatment approach for resistant hypertension. Sixty-nine subjects received renal denervation with externally delivered focused ultrasound via the Kona Medical Surround Sound System. This approach was investigated across 3 consecutive studies to optimize targeting, tracking, and dosing. In the third study, treatments were performed in a completely noninvasive way using duplex ultrasound image guidance to target the therapy. Short- and long-term safety and efficacy were evaluated through use of clinical assessments, magnetic resonance imaging scans prior to and 3 and 24 weeks after renal denervation, and, in cases in which a targeting catheter was used to facilitate targeting, fluoroscopic angiography with contrast. All patients tolerated renal denervation using externally delivered focused ultrasound. Office blood pressure (BP) decreased by 24.6 ± 27.6/9.0 ± 15.0 mm Hg (from baseline BP of 180.0 ± 18.5/97.7 ± 13.7 mm Hg) in 69 patients after 6 months and 23.8 ± 24.1/10.3 ± 13.1 mm Hg in 64 patients with complete 1-year follow-up. The response rate (BP decrease >10 mm Hg) was 75% after 6 months and 77% after 1 year. The most common adverse event was post-treatment back pain, which was reported in 32 of 69 patients and resolved within 72 h in most cases. No intervention-related adverse events involving motor or sensory deficits were reported. Renal function was not altered, and vascular safety was established by magnetic resonance imaging (all patients), fluoroscopic angiography (n = 48), and optical coherence tomography (n = 5). Using externally delivered focused ultrasound and noninvasive duplex ultrasound, image-guided targeting was associated with substantial BP reduction without any major safety signals. Further

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions.

Science.gov (United States)

Rigoni, Daniele; Morganti, Francesca; Braibanti, Paride

2017-01-01

Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES) functioning on the ability to deal with a stressor. Participants ( n = 70) were grouped into a minimized social interaction condition (procedure administered through a PC) and a social interaction condition (procedure administered by an experimenter). The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised.

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions

Directory of Open Access Journals (Sweden)

Daniele Rigoni

2017-11-01

Full Text Available Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES functioning on the ability to deal with a stressor. Participants (n = 70 were grouped into a minimized social interaction condition (procedure administered through a PC and a social interaction condition (procedure administered by an experimenter. The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised.

Mothers' responses to children's negative emotions and child emotion regulation: the moderating role of vagal suppression.

Science.gov (United States)

Perry, Nicole B; Calkins, Susan D; Nelson, Jackie A; Leerkes, Esther M; Marcovitch, Stuart

2012-07-01

The current study examined the moderating effect of children's cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and nonsupportive responses) and children's emotion regulation behaviors. One hundred and ninety-seven 4-year-olds and their mothers participated. Mothers reported on their reactions to children's negative emotions and children's regulatory behaviors. Observed distraction, an adaptive self-regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children's vagal suppression moderated the association between mothers' nonsupportive emotion socialization and children's emotion regulation behaviors such that nonsupportive reactions to negative emotions predicted lower observed distraction and lower reported emotion regulation behaviors when children displayed lower levels of vagal suppression. No interaction was found between supportive maternal emotion socialization and vagal suppression for children's emotion regulation behaviors. Results suggest physiological regulation may serve as a buffer against nonsupportive emotion socialization. Copyright © 2011 Wiley Periodicals, Inc.

The modulatory effects of noradrenaline on vagal control of heart rate in the dogfish, Squalus acanthias.

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Agnisola, Claudio; Randall, David J; Taylor, Edwin W

2003-01-01

The possible interactions between inhibitory vagal control of the heart and circulating levels of catecholamines in dogfish (Squalus acanthias) were studied using an in situ preparation of the heart, which retained intact its innervation from centrally cut vagus nerves. The response to peripheral vagal stimulation typically consisted of an initial cardiac arrest, followed by an escape beat, leading to renewed beating at a mean heart rate lower than the prestimulation rate (partial recovery). Cessation of vagal stimulation led to a transient increase in heart rate, above the prestimulation rate. This whole response was completely abolished by 10(-4) M atropine (a muscarinic cholinergic antagonist). The degree of vagal inhibition was evaluated in terms of both the initial, maximal cardiac interval and the mean heart rate during partial recovery, both expressed as a percentage of the prestimulation heart rate. The mean prestimulation heart rate of this preparation (36+/-4 beats min(-1)) was not affected by noradrenaline but was significantly reduced by 10(-4) M nadolol (a beta-adrenergic receptor antagonist), suggesting the existence of a resting adrenergic tone arising from endogenous catecholamines. The degree of vagal inhibition of heart rate varied with the rate of stimulation and was increased by the presence of 10(-8) M noradrenaline (the normal in vivo level in routinely active fish), while 10(-7) M noradrenaline (the in vivo level measured in disturbed or deeply hypoxic fish) reduced the cardiac response to vagal stimulation. In the presence of 10(-7) M noradrenaline, 10(-4) M nadolol further reduced the vagal response, while 10(-4) M nadolol + 10(-4) M phentolamine had no effect, indicating a complex interaction between adrenoreceptors, possibly involving presynaptic modulation of vagal inhibition.

Vagal activation by sham feeding improves gastric motility in functional dyspepsia.

Science.gov (United States)

Lunding, J A; Nordström, L M; Haukelid, A-O; Gilja, O H; Berstad, A; Hausken, T

2008-06-01

Antral hypomotility and impaired gastric accommodation in patients with functional dyspepsia have been ascribed to vagal dysfunction. We investigated whether vagal stimulation by sham feeding would improve meal-induced gastric motor function in these patients. Fourteen healthy volunteers and 14 functional dyspepsia patients underwent a drink test twice, once with and once without simultaneous sham feeding. After ingesting 500 mL clear meat soup (20 kcal, 37 degrees C) in 4 min, sham feeding was performed for 10 min by chewing a sugar-containing chewing gum while spitting out saliva. Using two- and three-dimensional ultrasound, antral motility index (contraction amplitude x frequency) and intragastric volumes were estimated. Without sham feeding, functional dyspepsia patients had lower motility index than healthy volunteers (area under curve 8.0 +/- 1.2 vs 4.4 +/- 1.0 min(-1), P = 0.04). In functional dyspepsia patients, but not in healthy volunteers, motility index increased and intragastric volume tended to increase by sham feeding (P = 0.04 and P = 0.06 respectively). The change in motility index was negatively correlated to the change in pain score (r = -0.59, P = 0.007). In functional dyspepsia patients, vagal stimulation by sham feeding improves antral motility in response to a soup meal. The result supports the view that impaired vagal stimulation is implicated in the pathogenesis of gastric motility disturbances in functional dyspepsia.

Parenting Stressors and Young Adolescents’ Depressive Symptoms: Does High Vagal Suppression Offer Protection?

Science.gov (United States)

Fletcher, Anne C.; Buehler, Cheryl; Buchanan, Christy M.; Weymouth, Bridget B.

2017-01-01

Grounded in a dual-risk, biosocial perspective of developmental psychopathology, this study examined the role of higher vagal suppression in providing young adolescents protection from four parenting stressors. It was expected that lower vagal suppression would increase youth vulnerability to the deleterious effects of these parenting stressors. Depressive symptoms were examined as a central marker of socioemotional difficulties during early adolescence. The four parenting stressors examined were interparental hostility, maternal use of harsh discipline, maternal inconsistent discipline, and maternal psychological control. Participants were 68 young adolescents (Grade 6) and their mothers. Greater vagal suppression provided protection (i.e., lower depressive symptoms) from interparental hostility, harsh discipline, and maternal psychological control for boys but not for girls. PMID:27979628

Inhibition of reflex vagal bradycardia by a central action of 5-hydroxytryptophan.

OpenAIRE

Tadepalli, A. S.

1980-01-01

1 Vagally mediated reflex bradycardia was elicited in spinal cats with intravenous pressor doses of noradrenaline. Administration of 5-hydroxytryptophan (1.5 and 3 mg total dose) into the fourth cerebral ventricle reduced the reflex bradycardia. 2 Inhibition of central amino acid decarboxylase with R044602 prevented the effects of 5-hydroxytryptophan. After intravenous administration of 5-hydroxytryptophan, vagal reflex bradycardia was not affected. 3 Results suggest that 5-hydroxytryptophan ...

Regional sympathetic denervation after myocardial infarction in humans detected noninvasively using I-123-metaiodobenzylguanidine

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Stanton, M.S.; Tuli, M.M.; Radtke, N.L.; Heger, J.J.; Miles, W.M.; Mock, B.H.; Burt, R.W.; Wellman, H.N.; Zipes, D.P. (Indiana Univ. School of Medicine, IN (USA))

1989-11-15

Transmural myocardial infarction in dogs produces denervation of sympathetic nerves in viable myocardium apical to the infarct that may be arrhythmogenic. It is unknown whether sympathetic denervation occurs in humans. The purpose of this study was to use iodine-123-metaiodobenzylguanidine (MIBG), a radiolabeled guanethidine analog that is actively taken up by sympathetic nerve terminals, to image noninvasively the cardiac sympathetic nerves in patients with and without ventricular arrhythmias after myocardial infarction. Results showed that 10 of 12 patients with spontaneous ventricular tachyarrhythmias after myocardial infarction exhibited regions of thallium-201 uptake indicating viable perfused myocardium, with no MIBG uptake. Such a finding is consistent with sympathetic denervation. One patient had frequent episodes of nonsustained ventricular tachycardia induced at exercise testing that was eliminated by beta-adrenoceptor blockade. Eleven of the 12 patients had ventricular tachycardia induced at electrophysiologic study and metoprolol never prevented induction. Sympathetic denervation was also detected in two of seven postinfarction patients without ventricular arrhythmias. Normal control subjects had no regions lacking MIBG uptake. This study provides evidence that regional sympathetic denervation occurs in humans after myocardial infarction and can be detected noninvasively by comparing MIBG and thallium-201 images. Although the presence of sympathetic denervation may be related to the onset of spontaneous ventricular tachyarrhythmias in some patients, it does not appear to be related to sustained ventricular tachycardia induced at electrophysiologic study.

High incidence of secondary hypertension in patients referred for renal denervation--the Copenhagen experience.

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Olsen, Lene Kjær; Kamper, Anne-Lise; Svendsen, Jesper Hastrup; Bang, Lia Evi; Frimodt-Møller, Marie; Kelbæk, Henning; Sander, Mikael; Feldt-Rasmussen, Bo

2014-08-01

Percutaneous renal denervation is a new treatment option for patients with resistant hypertension and little is known about the eligibility of patients referred. 100 consecutive patients were referred for renal denervation from March 2011 through September 2012. Clinical data were prospectively extracted from letters and documents from referring clinics and from our physical examination. Of the 100 patients included, 68 were men and the mean age was 60 (± 12) years. Office blood pressure was 176 (± 28)/99 (± 19) mmHg and 24-h ambulatory blood pressure 156 (± 20)/88 (± 13) mmHg. The mean number of antihypertensive agents was 4.0 (± 1.6). Nearly four-fifths (82%) of the patients were categorized as having resistant hypertension based on the criteria stated by The American Heart Association's stated criteria. Nine patients declined interest in renal denervation before completing the clinical workup program. Thus, 91 patients were screened, and of those 51 were found to be candidates for renal denervation. Forty patients were not candidates, of which secondary hypertension was the most common cause (n = 10). Only 51% of patients referred for renal denervation were eligible for treatment. The prevalence of secondary hypertension was 10% of the referred population. Secondary hypertension should therefore be considered in the evaluation of candidates for renal denervation.

Effects of extracts of denervated muscles on the morphology of cultured muscle cells

NARCIS (Netherlands)

Hooisma, J.; Krijger, J.de; Groot, D.M.G. de

1981-01-01

Previously tropic effects of extracts from whole chick embryos and from innervated muscles on cultured muscle cells were described. The present study demonstrated similar effects of extracts from 10-days denervated chick muscles. Extracts from innervated as well as from denervated muscles

Renal artery anatomy affects the blood pressure response to renal denervation in patients with resistant hypertension.

Science.gov (United States)

Hering, Dagmara; Marusic, Petra; Walton, Antony S; Duval, Jacqueline; Lee, Rebecca; Sata, Yusuke; Krum, Henry; Lambert, Elisabeth; Peter, Karlheinz; Head, Geoff; Lambert, Gavin; Esler, Murray D; Schlaich, Markus P

2016-01-01

Renal denervation (RDN) has been shown to reduce blood pressure (BP), muscle sympathetic nerve activity (MSNA) and target organ damage in patients with resistant hypertension (RH) and bilateral single renal arteries. The safety and efficacy of RDN in patients with multiple renal arteries remains unclear. We measured office and 24-hour BP at baseline, 3 and 6 months following RDN in 91 patients with RH, including 65 patients with single renal arteries bilaterally (group 1), 16 patients with dual renal arteries on either one or both sides (group 2) and 10 patients with other anatomical constellations or structural abnormalities (group 3). Thirty nine out of 91 patients completed MSNA at baseline and follow-up. RDN significantly reduced office and daytime SBP in group 1 at both 3 and 6 months follow-up (Pkidney function in any group. While RDN can be performed safely irrespective of the underlying renal anatomy, the presence of single renal arteries with or without structural abnormalities is associated with a more pronounced BP and MSNA lowering effect than the presence of dual renal arteries in patients with RH. However, when patients with dual renal arteries received renal nerve ablation in all arteries there was trend towards a greater BP reduction. Insufficient renal sympathetic nerve ablation may account for these differences. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Direct optical activation of skeletal muscle fibres efficiently controls muscle contraction and attenuates denervation atrophy.

Science.gov (United States)

Magown, Philippe; Shettar, Basavaraj; Zhang, Ying; Rafuse, Victor F

2015-10-13

Neural prostheses can restore meaningful function to paralysed muscles by electrically stimulating innervating motor axons, but fail when muscles are completely denervated, as seen in amyotrophic lateral sclerosis, or after a peripheral nerve or spinal cord injury. Here we show that channelrhodopsin-2 is expressed within the sarcolemma and T-tubules of skeletal muscle fibres in transgenic mice. This expression pattern allows for optical control of muscle contraction with comparable forces to nerve stimulation. Force can be controlled by varying light pulse intensity, duration or frequency. Light-stimulated muscle fibres depolarize proportionally to light intensity and duration. Denervated triceps surae muscles transcutaneously stimulated optically on a daily basis for 10 days show a significant attenuation in atrophy resulting in significantly greater contractile forces compared with chronically denervated muscles. Together, this study shows that channelrhodopsin-2/H134R can be used to restore function to permanently denervated muscles and reduce pathophysiological changes associated with denervation pathologies.

Randomized sham-controlled trial of renal sympathetic denervation in mild resistant hypertension.

Science.gov (United States)

Desch, Steffen; Okon, Thomas; Heinemann, Diana; Kulle, Konrad; Röhnert, Karoline; Sonnabend, Melanie; Petzold, Martin; Müller, Ulrike; Schuler, Gerhard; Eitel, Ingo; Thiele, Holger; Lurz, Philipp

2015-06-01

Few data are available with regard to the effectiveness of renal sympathetic denervation in patients with resistant hypertension yet only mildly elevated blood pressure (BP). Patients with resistant hypertension and slightly elevated BP (day-time systolic pressure, 135-149 and diastolic pressure, 90-94 mm Hg on 24-hour ambulatory measurement) were randomized in a 1:1 ratio to renal sympathetic denervation with the Symplicity Flex Catheter (Medtronic) or an invasive sham procedure. The primary efficacy end point was the change in 24-hour systolic BP at 6 months between groups in the intention to treat population. A total of 71 patients underwent randomization. Baseline day-time systolic BP was 144.4±4.8 mm Hg in patients assigned to denervation and 143.0±4.7 mm Hg in patients randomized to the sham procedure. The mean change in 24-hour systolic BP in the intention to treat cohort at 6 months was -7.0 mm Hg (95% confidence interval, -10.8 to -3.2) for patients undergoing denervation and -3.5 mm Hg (95% confidence interval, -6.7 to -0.2) in the sham group (P=0.15). In the per protocol population, the change in 24-hour systolic BP at 6 months was -8.3 mm Hg (95% confidence interval, -11.7 to -5.0) for patients undergoing denervation and -3.5 mm Hg (95% confidence interval, -6.8 to -0.2) in the sham group (P=0.042). In patients with mild resistant hypertension, renal sympathetic denervation failed to show a significant reduction in the primary end point of 24-hour systolic BP at 6 months between groups in the intention to treat analysis. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01656096. © 2015 American Heart Association, Inc.

Subacute mandibular and hypoglossal nerve denervation causing oedema of the masticator space and tongue

International Nuclear Information System (INIS)

Ho, T.; Lee, K.; Lee, H.

2003-01-01

We report the MRI of five patients with denervation oedema in the head and neck. Four had denervation oedema in one masticator space caused by a skull-base tumour invading the ipsilateral foramen ovale. Another case had denervation oedema confined to the half of the tongue ipsilateral to oral reconstruction surgery which involved mandibulectomy, free flap repair and wide excision of a buccal mucosal carcinoma. Inversion-recovery and/or T2-weighted spin-echo images showed increased signal in the affected areas. Contrast-enhanced T1-weighted images revealed enhancement of the muscles. There was no evidence of tumour or infection in the masticator space or tongue. It is important to differentiate denervation oedema from other disease processes causing high signal on T2-weighted images, such as tumour infiltration and soft-tissue infection. (orig.)

Irradiation-induced motor disorder of the oesophagus

Energy Technology Data Exchange (ETDEWEB)

Thorpe, J.A.C.; Oakland, C.; Adams, I.P.; Matthews, H.R. (East Birmingham Hospital (UK); Birmingham General Hospital (UK))

1982-08-01

This case report describes the late development of an achalasia-like disturbance of oesophageal motility following irradiation to the neck for a pharyngeal lymphosarcoma. The radiological, manometric and endoscopic findings are recorded as well as laboratory investigations showing evidence of complete vagal denervation.

Parenting stressors and young adolescents' depressive symptoms: Does high vagal suppression offer protection?

Science.gov (United States)

Fletcher, Anne C; Buehler, Cheryl; Buchanan, Christy M; Weymouth, Bridget B

2017-03-01

Grounded in a dual-risk, biosocial perspective of developmental psychopathology, this study examined the role of higher vagal suppression in providing young adolescents protection from four parenting stressors. It was expected that lower vagal suppression would increase youth vulnerability to the deleterious effects of these parenting stressors. Depressive symptoms were examined as a central marker of socioemotional difficulties during early adolescence. The four parenting stressors examined were interparental hostility, maternal use of harsh discipline, maternal inconsistent discipline, and maternal psychological control. Participants were 68 young adolescents (Grade 6) and their mothers. Greater vagal suppression provided protection (i.e., lower depressive symptoms) from interparental hostility, harsh discipline, and maternal psychological control for boys but not for girls. Copyright © 2016 Elsevier Inc. All rights reserved.

Endocrine cells in the denervated intestine

Science.gov (United States)

Santos, Gilda C; Zucoloto, Sérgio; Garcia, Sérgio B

2000-01-01

This study deals with the effects of myenteric denervation of the proximal jejunum on endocrine cell population of the crypt-villus unit, 5 months after treatment with benzalkonium chloride (BAC). Male Wistar albino rats weighing on average 100 g were allocated to two groups: the BAC group − the proximal jejunal serosa was treated with 2 mm BAC for 30 min, and the control group − treated with saline solution (0,9% NaCl). There was a significant reduction in neurone number in the jejunal myenteric plexus of the BAC group and the endocrine cell population (serotoninergic and argyrophilic cells) was significantly increased in this intestine segment. In conclusion, the present findings provide further evidence that the myenteric denervation induced by BAC may lead to the development of a local imbalance of the neurotransmitters, with a consequent induction of enteroendocrine cell (argyrophilic and serotoninergic cells) hyperplasia in the crypt and villus. PMID:10971748

Renal Denervation: Intractable Hypertension and Beyond

Science.gov (United States)

Ariyanon, Wassawon; Mao, Huijuan; Adýbelli, Zelal; Romano, Silvia; Rodighiero, Mariapia; Reimers, Bernhard; La Vecchia, Luigi; Ronco, Claudio

2014-01-01

Background Hypertension continues to be a major burden of public health concern despite the recent advances and proven benefit of pharmacological therapy. A certain subset of patients has hypertension resistant to maximal medical therapy and appropriate lifestyle measures. A novel catheter-based technique for renal denervation (RDN) as a new therapeutic avenue has great promise for the treatment of refractory hypertension. Summary This review included the physiology of the renal sympathetic nervous system and the renal nerve anatomy. Furthermore, the RDN procedure, technology systems, and RDN clinical trials as well as findings besides antihypertensive effects were discussed. Findings on safety and efficacy seem to suggest that renal sympathetic denervation could be of therapeutic benefit in refractory hypertensive patients. Despite the fast pace of development in RDN therapies, only initial and very limited clinical data are available. Large gaps in knowledge concerning the long-term effects and consequences of RDN still exist, and solid, randomized data are warranted. PMID:24847331

miRNA targeted signaling pathway in the early stage of denervated fast and slow muscle atrophy

Directory of Open Access Journals (Sweden)

Gang Li

2016-01-01

Full Text Available Denervation often results in skeletal muscle atrophy. Different mechanisms seem to be involved in the determination between denervated slow and fast skeletal muscle atrophy. At the epigenetic level, miRNAs are thought to be highly involved in the pathophysiological progress of denervated muscles. We used miRNA microarrays to determine miRNA expression profiles from a typical slow muscle (soleus muscle and a typical fast muscle (tibialis anterior muscle at an early denervation stage in a rat model. Results showed that miR-206, miR-195, miR-23a, and miR-30e might be key factors in the transformation process from slow to fast muscle in denervated slow muscles. Additionally, certain miRNA molecules (miR-214, miR-221, miR-222, miR-152, miR-320, and Let-7e could be key regulatory factors in the denervated atrophy process involved in fast muscle. Analysis of signaling pathway networks revealed the miRNA molecules that were responsible for regulating certain signaling pathways, which were the final targets (e.g., p38 MAPK pathway; Pax3/Pax7 regulates Utrophin and follistatin by HDAC4; IGF1/PI3K/Akt/mTOR pathway regulates atrogin-1 and MuRF1 expression via FoxO phosphorylation. Our results provide a better understanding of the mechanisms of denervated skeletal muscle pathophysiology.

Renal denervation and hypertension - The need to investigate unintended effects and neural control of the human kidney.

Science.gov (United States)

Grisk, Olaf

2017-05-01

Increased renal sympathetic nerve activity (RSNA) is present in human and experimental forms of arterial hypertension. Experimental denervation studies showed that renal nerves contribute to the development of hypertension. Clinical trials provided equivocal results on the antihypertensive efficacy of renal denervation in patients spurring discussions on technical aspects of renal denervation and further research on the role of renal nerves for the regulation of kidney function as well as the pathophysiology of hypertension. This review summarizes recent findings on adrenoceptor expression and function in the human kidney, adrenoceptor-dependent regulation of sodium chloride transport in the distal nephron, experimental data on chronic RSNA and the development of high arterial pressure and consequences of renal denervation that may limit its antihypertensive efficacy. Future research needs to reduce the gap between our knowledge on neural control of renal function in animals vs. humans to facilitate translation of experimental animal data to humans. More experimental studies on the temporal relationship between RSNA and arterial pressure in the chronic setting are needed to better define the pathogenetic role of heightened RSNA in different forms of arterial hypertension in order to improve the rational basis for renal denervation in antihypertensive therapy. Finally, research on unintended consequences of renal denervation including but not limited to reinnervation and denervation supersensitivity needs to be intensified to further assess the potential of renal denervation to slow the progression of renal disease and hypertension. Copyright © 2016 Elsevier B.V. All rights reserved.

Glucose turnover during insulin-induced hypoglycemia in liver-denervated rats

DEFF Research Database (Denmark)

Mikines, K J; Sonne, B; Richter, Erik

1985-01-01

The role of hepatic autonomic nerves in glucose production during hypoglycemia was studied. Selective, surgical denervation of the liver was performed in rats, which reduced hepatic norepinephrine concentrations by 96%. Hypoglycemia was induced by 250 mU of insulin intra-arterially in anesthetized...... as well as in chronically catheterized, awake rats. Half of the anesthetized denervated or sham-operated rats had previously been adrenodemedullated. Glucose turnover was measured by primed, constant intravenous infusion of [3-3H]glucose. Before as well as during hypoglycemia the arterial glucose...

Expression of TGF-β1 and CTGF Is Associated with Fibrosis of Denervated Sternocleidomastoid Muscles in Mice.

Science.gov (United States)

Liu, Fei; Tang, Weifang; Chen, Donghui; Li, Meng; Gao, Yinna; Zheng, Hongliang; Chen, Shicai

2016-01-01

Injury to the recurrent laryngeal nerve often leads to permanent vocal cord paralysis, which has a significant negative impact on the quality of life. Long-term denervation can induce laryngeal muscle fibrosis, which obstructs the muscle recovery after laryngeal reinnervation. However, the mechanisms of fibrosis remain unclear. In this study, we aimed to analyze the changes in the expression of fibrosis-related factors, including transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), and α-smooth muscle actin (α-SMA) in denervated skeletal muscles using a mouse model of accessory nerve transection. Because of the small size, we used sternocleidomastoid muscles instead of laryngeal muscles for denervation experiments. Masson's trichrome staining showed that the grade of atrophy and fibrosis of muscles became more severe with time, but showed a plateau at 4 weeks after denervation, followed by a slow decrease. Quantitative assessment and immunohistochemistry showed that TGF-β1 expression peaked at 1 week after denervation (p muscle cells were detected at 1 week after denervation, peaked at 2 weeks (p muscle fibrosis. They may induce the differentiation of myoblasts into myofibroblasts, as characterized by the activation of α-SMA. These findings may provide insights on key pathological processes in denervated skeletal muscle fibrosis and develop novel therapeutic strategies.

Glucose-dependent trafficking of 5-HT3 receptors in rat gastrointestinal vagal afferent neurons

Science.gov (United States)

Babic, Tanja; Troy, Amanda E; Fortna, Samuel R; Browning, Kirsteen N

2012-01-01

Background Intestinal glucose induces gastric relaxation via vagally mediated sensory-motor reflexes. Glucose can alter the activity of gastrointestinal (GI) vagal afferent (sensory) neurons directly, via closure of ATP-sensitive potassium channels, as well as indirectly, via the release of 5-hydroxytryptamine (5-HT) from mucosal enteroendocrine cells. We hypothesized that glucose may also be able to modulate the ability of GI vagal afferent neurons to respond to the released 5-HT, via regulation of neuronal 5-HT3 receptors. Methods Whole cell patch clamp recordings were made from acutely dissociated GI-projecting vagal afferent neurons exposed to equiosmolar Krebs’ solution containing different concentrations of D-glucose (1.25–20mM) and the response to picospritz application of 5-HT assessed. The distribution of 5-HT3 receptors in neurons exposed to different glucose concentrations was also assessed immunohistochemically. Key Results Increasing or decreasing extracellular D-glucose concentration increased or decreased, respectively, the 5-HT-induced inward current as well as the proportion of 5-HT3 receptors associated with the neuronal membrane. These responses were blocked by the Golgi-disrupting agent Brefeldin-A (5µM) suggesting involvement of a protein trafficking pathway. Furthermore, L-glucose did not mimic the response of D-glucose implying that metabolic events downstream of neuronal glucose uptake are required in order to observe the modulation of 5-HT3 receptor mediated responses. Conclusions & Inferences These results suggest that, in addition to inducing the release of 5-HT from enterochromaffin cells, glucose may also increase the ability of GI vagal sensory neurons to respond to the released 5-HT, providing a means by which the vagal afferent signal can be amplified or prolonged. PMID:22845622

Impact of renal denervation on 24-hour ambulatory blood pressure: results from SYMPLICITY HTN-3.

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Bakris, George L; Townsend, Raymond R; Liu, Minglei; Cohen, Sidney A; D'Agostino, Ralph; Flack, John M; Kandzari, David E; Katzen, Barry T; Leon, Martin B; Mauri, Laura; Negoita, Manuela; O'Neill, William W; Oparil, Suzanne; Rocha-Singh, Krishna; Bhatt, Deepak L

2014-09-16

Prior studies of catheter-based renal artery denervation have not systematically performed ambulatory blood pressure monitoring (ABPM) to assess the efficacy of the procedure. SYMPLICITY HTN-3 (Renal Denervation in Patients With Uncontrolled Hypertension) was a prospective, blinded, randomized, sham-controlled trial. The current analysis details the effect of renal denervation or a sham procedure on ABPM measurements 6 months post-randomization. Patients with resistant hypertension were randomized 2:1 to renal denervation or sham control. Patients were on a stable antihypertensive regimen including maximally tolerated doses of at least 3 drugs including a diuretic before randomization. The powered secondary efficacy endpoint was a change in mean 24-h ambulatory systolic blood pressure (SBP). Nondipper to dipper (nighttime blood pressure [BP] 10% to 20% lower than daytime BP) conversion was calculated at 6 months. The 24-h ambulatory SBP changed -6.8 ± 15.1 mm Hg in the denervation group and -4.8 ± 17.3 mm Hg in the sham group: difference of -2.0 mm Hg (95% confidence interval [CI]: -5.0 to 1.1; p = 0.98 with a 2 mm Hg superiority margin). The daytime ambulatory SBP change difference between groups was -1.1 (95% CI: -4.3 to 2.2; p = 0.52). The nocturnal ambulatory SBP change difference between groups was -3.3 (95 CI: -6.7 to 0.1; p = 0.06). The percent of nondippers converted to dippers was 21.2% in the denervation group and 15.0% in the sham group (95% CI: -3.8% to 16.2%; p = 0.30). Change in 24-h heart rate was -1.4 ± 7.4 in the denervation group and -1.3 ± 7.3 in the sham group; (95% CI: -1.5 to 1.4; p = 0.94). This trial did not demonstrate a benefit of renal artery denervation on reduction in ambulatory BP in either the 24-h or day and night periods compared with sham (Renal Denervation in Patients With Uncontrolled Hypertension [SYMPLICITY HTN-3]; NCT01418261). Copyright © 2014 American College of Cardiology Foundation. Published by

Renal denervation in a patient with Alport syndrome and rejected renal allograft

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Raju, Narayana; Lloyd, Vincent; Yalagudri, Sachin; Das, Bharati; Ravikishore, A.G.

2015-01-01

Renal denervation is a new intervention to treat resistant hypertension. By applying radiofrequency (RF) to renal arteries, sympathetic nerves in adventitia layer of vascular wall can be denervated. Sympathetic hyperactivity is an important contributory factor in hypertension of hemodialysis patients. Hyperactive sympathetic nervous system aggravates hypertension and it can cause complications like left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. Our report illustra...

Irradiation-induced motor disorder of the oesophagus

International Nuclear Information System (INIS)

Thorpe, J.A.C.; Oakland, C.; Adams, I.P.; Matthews, H.R.

1982-01-01

This case report describes the late development of an achalasia-like disturbance of oesophageal motility following irradiation to the neck for a pharyngeal lymphosarcoma. The radiological, manometric and endoscopic findings are recorded as well as laboratory investigations showing evidence of complete vagal denervation. (author)

Clonidine, an alpha2-receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

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Philbin, Kerry E; Bateman, Ryan J; Mendelowitz, David

2010-08-06

In hypertension, there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Presympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these presympathetic neurons are catecholaminergic. In addition to their projection to the spinal cord, many of these presympathetic neurons have axon collaterals that arborize into neighboring cardiorespiratory locations and likely release norepinephrine onto nearby neurons. Activation of alpha(2)-adrenergic receptors in the central nervous system evokes a diverse range of physiological effects, including reducing blood pressure. This study tests whether clonidine, an alpha(2)-adrenergic receptor agonist, alters excitatory glutamatergic, and/or inhibitory GABAergic or glycinergic synaptic neurotransmission to cardiac vagal neurons in the nucleus ambiguus. Cardiac vagal neurons were identified in an in vitro brainstem slice preparation, and synaptic events were recording using whole cell voltage clamp methodologies. Clonidine significantly inhibited GABAergic neurotransmission but had no effect on glycinergic or glutamatergic pathways to cardiac vagal neurons. This diminished inhibitory GABAergic neurotransmission to cardiac vagal neurons would increase parasympathetic activity to the heart, decreasing heart rate and blood pressure. The results presented here provide a cellular substrate for the clinical use of clonidine as a treatment for hypertension as well as a role in alleviating posttraumatic stress disorder by evoking an increase in parasympathetic cardiac vagal activity, and a decrease in heart rate and blood pressure. Copyright 2010 Elsevier B.V. All rights reserved.

Cooled microwave ablation of thyroid nodules: Initial experience

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Korkusuz, Yücel [Department of Nuclear Medicine, University Hospital Frankfurt (Germany); Mader, Oscar Maximilian, E-mail: info@dzta.de [Department of Nuclear Medicine, University Hospital Frankfurt (Germany); Kromen, Wolfgang [Department of Neuro Radiology University Hospital (Germany); Happel, Christian [Department of Nuclear Medicine, University Hospital Frankfurt (Germany); German Centre for Thermoablation of Thyroid Nodules, University Hospital, Frankfurt (Germany); Ahmad, Shadi [Department of General and Visceral Surgery, Agaplesion Elisabethenstift, Darmstadt (Germany); Gröner, Daniel; Koca, Mithat; Mader, Alexander [Department of Nuclear Medicine, University Hospital Frankfurt (Germany); Grünwald, Frank; Korkusuz, Hüdayi [Department of Nuclear Medicine, University Hospital Frankfurt (Germany); German Centre for Thermoablation of Thyroid Nodules, University Hospital, Frankfurt (Germany)

2016-11-15

Highlights: • cMWA is a safe and effective treatment for thyroid nodules. • Ultrasound imaging allows guidance during microwave ablation. • Pain level during cMWA treatment is reduced in comparison to RFA. - Abstract: Objective: To evaluate if internally cooled microwave ablation (cMWA) is a safe and effective method for treatment of benign and malign thyroid nodules. Methods: 9 patients with 11 symptomatic cold benign thyroid nodules and 1 recurrent thyroid carcinoma ranging in volume from 9.1 to 197 ml (mean size 52 ±  57 ml) were treated with cMWA. The mean age of the patients was 59 years. Pain during the treatment was measured on a 10-point scale. Side effects revealed by ultrasound or patients’ complaints were documented. Periablative efficacy was measured 24 h after cMWA as change (Δ) in serum thyreoglobulin (Tg). Nodule elasticity was measured on a 4-point scale, blood circulation and echogenicity on a 3-point scale. Results: All patients tolerated cMWA well. Median pain intensity averaged 2.1 ± 0.8 (range: 1–3). Postablative hematoma was observed in all cases. In no cases ablation led to hoarseness, superficial burns, nodule ruptures, vagal reactions or dysphagia. cMWA lead to a significant decrease of blood circulation, nodule echogenicity and a significant increase of elasticity (Δ  =  1.1  ±  0.33; 0.8  ±  0.4 and 1.1  ±  0.6 points)(p < 0.05). An average increase of 4495 ng/ml Tg was measured (p < 0.05). Conclusions: cMWA is an effective and secure method for treatment of thyroid nodules.

Radiofrequency Denervation Improves Health-Related Quality of Life in Patients with Thoracic Zygapophyseal Joint Pain.

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Hambraeus, Johan; Hambraeus, Kjerstin S; Persson, Jan

2018-05-01

To describe a practical approach for the diagnosis and treatment of thoracic zygapophyseal joint pain and to present preliminary clinical data on the effects of this treatment approach on health-related quality of life. An observational study. Specialist outpatient pain clinic in northern Sweden. Patients with long-term thoracic pain. We describe a method of radiofrequency denervation of thoracic zygapophyseal joints. We compared health-related quality of life between patients who underwent radiofrequency denervation of thoracic zygapophyseal joints and patients who underwent radiofrequency denervation for lumbar and cervical zygapophyseal joint pain. Treatment according to the Spine Intervention Society Guidelines was performed on the lumbar region in 178 patients and in the cervical region in 55 patients. Another 82 patients were treated in the thoracic region with our proposed technique. A survival plot of improvements in health-related quality of life revealed that all three treatments were effective in 65% or more of patients. The improvement in health-related quality of life was maintained for 12 or more months after treatment in 47% to 51% of patients. Our results suggest that radiofrequency denervation of thoracic zygapophyseal joint pain is as effective as radiofrequency denervation, the standard treatment, for lumbar and cervical zygapophyseal joint pain. If these results can be confirmed by other centers, radiofrequency denervation is likely to become more widely available for the treatment of thoracic zygapophyseal joint pain.

Leucine minimizes denervation-induced skeletal muscle atrophy of rats through akt/mtor signaling pathways

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Carolina Barbosa Ribeiro

2015-03-01

Full Text Available The aim of the present study was to evaluate the effect of leucine treatment (0.30 mM on muscle weight and signaling of myoproteins related to synthesis and degradation pathways of soleus muscle following seven days of complete sciatic nerve lesion.Wistar rats (n=24 of 3 to 4 months of age (192 ± 23 g were used. The animals were randomly distributed into four experimental groups (n=6/group: control, treated with leucine (L, denervated (D and denervated treated with leucine (DL.Dependent measures were proteins levels of AKT, AMPK, mTOR, and ACC performed by Western blot. Leucine induced a reduction in the phosphorylation of AMPK (p<0.05 by 16% in the L and by 68% in the DL groups as compared with control group. Denervation increased AMPK by 24% in the D group as compared with the control group (p<0.05. AKT was also modulated by denervation and leucine treatment, highlighted by the elevation of AKT phosphorylation in the D (65%, L (98% and DL (146% groups as compared with the control group (p<0.05. AKT phosphorylation was 49% higher in the D group as compared with the DL group.Furthermore, denervation decreased mTOR phosphorylation by 29% in the D group as compared with the control group. However, leucine treatment induced an increase of 49% in the phosphorylation of mTOR in the L group as compared with the control group, and an increase of 154% in the DL as compared with the D group ( p<0.05. ACC phosphorylation was 20% greater in the D group than the control group. Furthermore, ACC in the soleus was 22% lower in the in the L group and 50% lower in the DL group than the respective control group (p<0.05.In conclusion, leucine treatment minimized the deleterious effects of denervation on rat soleus muscle by increasing anabolic (AKT and mTOR and decreasing catabolic (AMPK pathways. These results may be interesting for muscle recovery following acute denervation, which may contribute to musculoskeletal rehabilitation after denervation.

Relationship between vagal tone, cortisol, TNF-alpha, epinephrine and negative affects in Crohn's disease and irritable bowel syndrome.

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Pellissier, Sonia; Dantzer, Cécile; Mondillon, Laurie; Trocme, Candice; Gauchez, Anne-Sophie; Ducros, Véronique; Mathieu, Nicolas; Toussaint, Bertrand; Fournier, Alicia; Canini, Frédéric; Bonaz, Bruno

2014-01-01

Crohn's disease (CD) and irritable bowel syndrome (IBS) involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls). The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients). The day prior to the experiment, salivary cortisol was measured at 8:00 AM and 10:00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI) and depressive symptoms (CES-D). After 30 min of rest, ECG was recorded for heart rate variability (HRV) analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu) as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r =  -0.48; p<0.05) was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r =  -0.39; p<0.05). No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology) in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases.

Relationship between vagal tone, cortisol, TNF-alpha, epinephrine and negative affects in Crohn's disease and irritable bowel syndrome.

Directory of Open Access Journals (Sweden)

Sonia Pellissier

Full Text Available Crohn's disease (CD and irritable bowel syndrome (IBS involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls. The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients. The day prior to the experiment, salivary cortisol was measured at 8:00 AM and 10:00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI and depressive symptoms (CES-D. After 30 min of rest, ECG was recorded for heart rate variability (HRV analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r =  -0.48; p<0.05 was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r =  -0.39; p<0.05. No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases.

Renal denervation for the treatment of resistant hypertension: review and clinical perspective.

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Iliescu, Radu; Lohmeier, Thomas E; Tudorancea, Ionut; Laffin, Luke; Bakris, George L

2015-10-01

When introduced clinically 6 years ago, renal denervation was thought to be the solution for all patients whose blood pressure could not be controlled by medication. The initial two studies, SYMPLICITY HTN-1 and HTN-2, demonstrated great magnitudes of blood pressure reduction within 6 mo of the procedure and were based on a number of assumptions that may not have been true, including strict adherence to medication and absence of white-coat hypertension. The SYMPLICITY HTN-3 trial controlled for all possible factors believed to influence the outcome, including the addition of a sham arm, and ultimately proved the demise of the initial overly optimistic expectations. This trial yielded a much lower blood pressure reduction compared with the previous SYMPLICITY trials. Since its publication in 2014, there have been many analyses to try and understand what accounted for the differences. Of all the variables examined that could influence blood pressure outcomes, the extent of the denervation procedure was determined to be inadequate. Beyond this, the physiological mechanisms that account for the heterogeneous fall in arterial pressure following renal denervation remain unclear, and experimental studies indicate dependence on more than simply reduced renal sympathetic activity. These and other related issues are discussed in this paper. Our perspective is that renal denervation works if done properly and used in the appropriate patient population. New studies with new approaches and catheters and appropriate controls will be starting later this year to reassess the efficacy and safety of renal denervation in humans. Copyright © 2015 the American Physiological Society.

Renal Denervation for Treatment of Hypertension: a Second Start and New Challenges.

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Persu, Alexandre; Kjeldsen, Sverre; Staessen, Jan A; Azizi, Michel

2016-01-01

Following the publication of the randomized controlled but open-label trial Symplicity HTN-2, catheter-based renal sympathetic denervation was proposed as a novel treatment for drug-resistant hypertension. Thousands of procedures were routinely performed in Europe, Australia and Asia, and many observational studies were published. A sudden shift from overoptimistic views to radical scepticism occurred later, when the large US randomized sham-controlled trial Symplicity HTN-3 failed to meet its primary blood pressure lowering efficacy endpoint. Experts are divided on the reasons accounting for the large discrepancy between the results of initial studies and those of Symplicity HTN-3. Indeed, the blood pressure lowering effect associated with renal denervation was overestimated in initial trials due to various patient and physician-related biases, whereas it could have been underestimated in Symplicity HTN-3, which was well designed but not rigorously executed. Still, there is a large consensus on the need to further study catheter-based renal denervation in more controlled conditions, with particular emphasis on identification of predictors of blood pressure response. US and European experts have recently issued very similar recommendations on design of upcoming trials, procedural aspects, drug treatment, patient population and inclusion-exclusion criteria. Application of these new standards may represent a second chance for renal denervation to demonstrate--or not--its efficacy and safety in various patient populations. With its highly standardized treatment regimen, the French trial DENERHTN paved the way for this new approach and may inspire upcoming studies testing novel renal denervation systems in different populations.

Effects of nerve growth factor on the neurotization of denervated muscles.

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Menderes, Adnan; Yilmaz, Mustafa; Vayvada, Haluk; Ozer, Erdener; Barutçu, Ali

2002-04-01

Studies on surgical repair techniques of the peripheral nerve are still trying to improve the outcome. There are many studies on the effects of various neurotrophic factors on the transected peripheral nerve. Muscular neurotization, which is the direct implantation of the nerve to the target denervated skeletal muscle, is one of the techniques used when the primary repair of the peripheral nerves is not possible. The effects of nerve growth factor (NGF), which is one of the primary neurotrophic factors, on the reinnervation of denervated muscles by neurotization is investigated in this experimental study. The denervated soleus muscle was neurotized via peroneal nerve implantation (group 1), and NGF was administered to the neurotized muscle (group 2). All animals were evaluated at weeks 8, 10, and 12 using electromyography. Muscle contractility, muscle weight, and histological morphometric tests were performed at week 12. The experimental groups were compared with each other and normal control values. Electromyographically, group 2 (direct nerve implantation + NGF) demonstrated better reinnervation in all evaluations. The study of muscle weight showed that the muscle mass was 75% of the normal soleus muscle in group 1 and was 85% of the normal side in group 2 at the end of week 12. In group 1, the twitch force was 56% of the normal soleus muscle and was 71% in group 2. Tetanic force was 53% of the normal soleus muscle in group 1 and 68% in group 2. Histological morphometric studies revealed that there was a decrease in the density of the motor end plates in group 1, but there was no statistically significant difference between the normal soleus muscles and the NGF applied to group 2. The positive effects of NGF on the neurotization of denervated muscles seen in this study suggest that it may be useful for treating some difficult reconstructions caused by denervation.

Technical aspects of renal denervation in end-stage renal disease patients with challenging anatomy.

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Spinelli, Alessio; Da Ros, Valerio; Morosetti, Daniele; Onofrio, Silvia D; Rovella, Valentina; Di Daniele, Nicola; Simonetti, Giovanni

2014-01-01

We describe our preliminary experience with percutaneous renal denervation in end-stage renal disease patients with resistant hypertension and challenging anatomy, in terms of the feasibility, safety, and efficacy of this procedure. Four patients with end-stage renal disease patients with resistant hypertension (mean hemodialysis time, 2.3 years) who had been taking at least four antihypertensive medications underwent percutaneous renal denervation. Renal artery eligibility included the absence of prior renal artery interventions, vessel stenosis renal denervation is a feasible approach for end-stage renal disease patients with resistant hypertension with encouraging short-term preliminary results in terms of procedural efficacy and safety.

An Update on Renal Artery Denervation and Its Clinical Impact on Hypertensive Disease

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Aditya Bhat

2015-01-01

Full Text Available Hypertension is a globally prevalent condition, with a heavy clinical and economic burden. It is the predominant risk factor for premature cardiovascular and cerebrovascular disease, and is associated with a variety of clinical disorders including stroke, congestive cardiac failure, ischaemic heart disease, chronic renal failure, and peripheral arterial disease. A significant subset of hypertensive patients have resistant hypertensive disease. In this group of patients, catheter-based renal artery denervation has emerged as a potential therapy, with favourable clinical efficacy and safety in early trials. Additional benefits of this therapy are also being identified and include effects on left ventricular remodeling, cardiac performance, and symptom status in congestive cardiac failure. Utility of renal denervation for the management of resistant hypertension, however, has become controversial since the release of the Symplicity HTN-3 trial, the first large-scale blinded randomised study investigating the efficacy and safety of renal artery denervation. The aim of this paper is to evaluate the history, utility, and clinical efficacy of renal artery denervation technology, including an in-depth appraisal of the current literature and principal trials.

An Update on Renal Artery Denervation and Its Clinical Impact on Hypertensive Disease

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Kuang, Ye Min; Gan, Gary C. H.; Burgess, David; Denniss, Alan Robert

2015-01-01

Hypertension is a globally prevalent condition, with a heavy clinical and economic burden. It is the predominant risk factor for premature cardiovascular and cerebrovascular disease, and is associated with a variety of clinical disorders including stroke, congestive cardiac failure, ischaemic heart disease, chronic renal failure, and peripheral arterial disease. A significant subset of hypertensive patients have resistant hypertensive disease. In this group of patients, catheter-based renal artery denervation has emerged as a potential therapy, with favourable clinical efficacy and safety in early trials. Additional benefits of this therapy are also being identified and include effects on left ventricular remodeling, cardiac performance, and symptom status in congestive cardiac failure. Utility of renal denervation for the management of resistant hypertension, however, has become controversial since the release of the Symplicity HTN-3 trial, the first large-scale blinded randomised study investigating the efficacy and safety of renal artery denervation. The aim of this paper is to evaluate the history, utility, and clinical efficacy of renal artery denervation technology, including an in-depth appraisal of the current literature and principal trials. PMID:26495305

Denervation syndromes of the shoulder girdle: MR imaging with electrophysiologic correlation

International Nuclear Information System (INIS)

Bredella, M.A.; Wischer, T.K.; Stork, A.; Genant, H.K.; Tirman, P.F.J.; Fritz, R.C.

1999-01-01

Objective. To investigate the use of MR imaging in the characterization of denervated muscle of the shoulder correlated with electrophysiologic studies.Design and patients. We studied with MR imaging five patients who presented with shoulder weakness and pain and who underwent electrophysiologic studies. On MR imaging the distribution of muscle edema and fatty infiltration was recorded, as was the presence of masses impinging on a regional nerve.Results. Acute/subacute denervation was best seen on T2-weighted fast spin-echo images with fat saturation, showing increased SI related to neurogenic edema. Chronic denervation was best seen on T1-weighted spin-echo images, demonstrating loss of muscle bulk and diffuse areas of increased signal intensity within the muscle. Three patients showed MR imaging and electrophysiologic findings of Parsonage Turner syndrome. One patient demonstrated an arteriovenous malformation within the spinoglenoid notch, impinging on the suprascapular nerve with associated atrophy of the infraspinatus muscle. The fifth patient demonstrated fatty atrophy of the teres minor muscle caused by compression by a cyst of the axillary nerve and electrophysiologic findings of an incomplete axillary nerve block.Conclusion. MR imaging is useful in detecting and characterizing denervation atrophy and neurogenic edema in shoulder muscles. MR imaging can provide additional information to electrophysiologic studies by estimating the age (acute/chronic) and identifying morphologic causes for shoulder pain and atrophy. (orig.)

12-month blood pressure results of catheter-based renal artery denervation for resistant hypertension: the SYMPLICITY HTN-3 trial.

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Bakris, George L; Townsend, Raymond R; Flack, John M; Brar, Sandeep; Cohen, Sidney A; D'Agostino, Ralph; Kandzari, David E; Katzen, Barry T; Leon, Martin B; Mauri, Laura; Negoita, Manuela; O'Neill, William W; Oparil, Suzanne; Rocha-Singh, Krishna; Bhatt, Deepak L

2015-04-07

Results of the SYMPLICITY HTN-3 (Renal Denervation in Patients With Uncontrolled Hypertension) trial confirmed the safety but not the efficacy of renal denervation for treatment-resistant hypertension at 6 months post procedure. This study sought to analyze the 12-month SYMPLICITY HTN-3 results for the original denervation group, the sham subjects who underwent denervation after the 6-month endpoint (crossover group), and the sham subjects who did not undergo denervation after 6 months (non-crossover group). Eligible subjects were randomized 2:1 to denervation or sham procedure. Subjects were unblinded to their treatment group after the 6-month primary endpoint was ascertained; subjects in the sham group meeting eligibility requirements could undergo denervation. Change in blood pressure (BP) at 12 months post randomization (6 months for crossover subjects) was analyzed. The 12-month follow-up was available for 319 of 361 denervation subjects and 48 of 101 non-crossover subjects; 6-month denervation follow-up was available for 93 of 101 crossover subjects. In denervation subjects, the 12-month office systolic BP (SBP) change was greater than that observed at 6 months (-15.5 ± 24.1 mm Hg vs. -18.9 ± 25.4 mm Hg, respectively; p = 0.025), but the 24-h SBP change was not significantly different at 12 months (p = 0.229). The non-crossover group office SBP decreased by -32.9 ± 28.1 mm Hg at 6 months, but this response regressed to -21.4 ± 19.9 mm Hg (p = 0.01) at 12 months, increasing to 11.5 ± 29.8 mm Hg. These data support no further reduction in office or ambulatory BP after 1-year follow-up. Loss of BP reduction in the non-crossover group may reflect decreased medication adherence or other related factors. (Renal Denervation in Patients With Uncontrolled Hypertension [SYMPLICITY HTN-3]; NCT01418261). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

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Mukudai, Shigeyuki; Ichi Matsuda, Ken; Bando, Hideki; Takanami, Keiko; Nishio, Takeshi; Sugiyama, Yoichiro; Hisa, Yasuo; Kawata, Mitsuhiro

2016-01-01

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus

HDAC4 preserves skeletal muscle structure following long-term denervation by mediating distinct cellular responses.

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Pigna, Eva; Renzini, Alessandra; Greco, Emanuela; Simonazzi, Elena; Fulle, Stefania; Mancinelli, Rosa; Moresi, Viviana; Adamo, Sergio

2018-02-24

Denervation triggers numerous molecular responses in skeletal muscle, including the activation of catabolic pathways and oxidative stress, leading to progressive muscle atrophy. Histone deacetylase 4 (HDAC4) mediates skeletal muscle response to denervation, suggesting the use of HDAC inhibitors as a therapeutic approach to neurogenic muscle atrophy. However, the effects of HDAC4 inhibition in skeletal muscle in response to long-term denervation have not been described yet. To further study HDAC4 functions in response to denervation, we analyzed mutant mice in which HDAC4 is specifically deleted in skeletal muscle. After an initial phase of resistance to neurogenic muscle atrophy, skeletal muscle with a deletion of HDAC4 lost structural integrity after 4 weeks of denervation. Deletion of HDAC4 impaired the activation of the ubiquitin-proteasome system, delayed the autophagic response, and dampened the OS response in skeletal muscle. Inhibition of the ubiquitin-proteasome system or the autophagic response, if on the one hand, conferred resistance to neurogenic muscle atrophy; on the other hand, induced loss of muscle integrity and inflammation in mice lacking HDAC4 in skeletal muscle. Moreover, treatment with the antioxidant drug Trolox prevented loss of muscle integrity and inflammation in in mice lacking HDAC4 in skeletal muscle, despite the resistance to neurogenic muscle atrophy. These results reveal new functions of HDAC4 in mediating skeletal muscle response to denervation and lead us to propose the combined use of HDAC inhibitors and antioxidant drugs to treat neurogenic muscle atrophy.

Effects of vasoactive intestinal polypeptide on heart rate in relation to vagal cardioacceleration in conscious dogs

NARCIS (Netherlands)

Roossien, A; Brunstig, J.R; Nijmeijer, A; Zaagsma, Hans; Zijlstra, W.G

Objective: The vagal cardiac accelerator (VCA) system takes part in the nervous control of the heart rate. In the present study we tried to adduce evidence that vasoactive intestinal polypeptide (VLP) contributes to vagally induced cardioacceleration. Methods: The effect of VIP on heart rate and

A controlled trial of renal denervation for resistant hypertension.

Science.gov (United States)

Bhatt, Deepak L; Kandzari, David E; O'Neill, William W; D'Agostino, Ralph; Flack, John M; Katzen, Barry T; Leon, Martin B; Liu, Minglei; Mauri, Laura; Negoita, Manuela; Cohen, Sidney A; Oparil, Suzanne; Rocha-Singh, Krishna; Townsend, Raymond R; Bakris, George L

2014-04-10

Prior unblinded studies have suggested that catheter-based renal-artery denervation reduces blood pressure in patients with resistant hypertension. We designed a prospective, single-blind, randomized, sham-controlled trial. Patients with severe resistant hypertension were randomly assigned in a 2:1 ratio to undergo renal denervation or a sham procedure. Before randomization, patients were receiving a stable antihypertensive regimen involving maximally tolerated doses of at least three drugs, including a diuretic. The primary efficacy end point was the change in office systolic blood pressure at 6 months; a secondary efficacy end point was the change in mean 24-hour ambulatory systolic blood pressure. The primary safety end point was a composite of death, end-stage renal disease, embolic events resulting in end-organ damage, renovascular complications, or hypertensive crisis at 1 month or new renal-artery stenosis of more than 70% at 6 months. A total of 535 patients underwent randomization. The mean (±SD) change in systolic blood pressure at 6 months was -14.13±23.93 mm Hg in the denervation group as compared with -11.74±25.94 mm Hg in the sham-procedure group (Pdenervation group and -4.79±17.25 mm Hg in the sham-procedure group, for a difference of -1.96 mm Hg (95% CI, -4.97 to 1.06; P=0.98 for superiority with a margin of 2 mm Hg). There were no significant differences in safety between the two groups. This blinded trial did not show a significant reduction of systolic blood pressure in patients with resistant hypertension 6 months after renal-artery denervation as compared with a sham control. (Funded by Medtronic; SYMPLICITY HTN-3 ClinicalTrials.gov number, NCT01418261.).

Increased phencyclidine-induced hyperactivity following cortical cholinergic denervation.

Science.gov (United States)

Mattsson, Anna; Lindqvist, Eva; Ogren, Sven Ove; Olson, Lars

2005-11-07

Altered cholinergic function is considered as a potential contributing factor in the pathogenesis of schizophrenia. We hypothesize that cortical cholinergic denervation may result in changes in glutamatergic activity. Therefore, we lesioned the cholinergic corticopetal projections by local infusion of 192 IgG-saporin into the nucleus basalis magnocellularis of rats. Possible effects of this lesion on glutamatergic systems were examined by phencyclidine-induced locomotor activity, and also by N-methyl-D-aspartate receptor binding. We find that cholinergic lesioning of neocortex leads to enhanced sensitivity to phencyclidine in the form of a dramatic increase in horizontal activity. Further, N-methyl-D-aspartate receptor binding is unaffected in denervated rats. These results suggest that aberrations in cholinergic function might lead to glutamatergic dysfunctions, which might be of relevance for the pathophysiology for schizophrenia.

Cholecystokinin enhances visceral pain-related affective memory via vagal afferent pathway in rats

Directory of Open Access Journals (Sweden)

Cao Bing

2012-06-01

Full Text Available Abstract Background Pain contains both sensory and affective dimensions. Using a rodent visceral pain assay that combines the colorectal distension (CRD model with the conditioned place avoidance (CPA paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Progress has been made and suggested that activation of vagal afferents plays a role in the behavioral control nociception and memory storage processes. In human patients, electrical vagus nerve stimulation enhanced retention of verbal learning performance. Cholecystokinin-octapeptide (CCK, which is a gastrointestinal hormone released during feeding, has been shown to enhance memory retention. Mice access to food immediately after training session enhanced memory retention. It has been well demonstrated that CCK acting on vagal afferent fibers mediates various physiological functions. We hypothesize that CCK activation of vagal afferent enhances visceral pain-related affective memory. Results In the presented study, infusion of CCK-8 at physiological concentration combining with conditional training significantly increased the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, CCK had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593. The physiological implications were further strengthened by the similar effects observed in the rats with duodenal infusion of 5% peptone, which has been shown to induce increases in plasma CCK levels. CCK-8 receptor antagonist CR-1409 or perivagal application of capsaicin abolished the effect of CCK on aversive visceral pain memory, which was consistent with the notion that vagal afferent modulates affective aspects of visceral pain. CCK does not change

Cholecystokinin enhances visceral pain-related affective memory via vagal afferent pathway in rats.

Science.gov (United States)

Cao, Bing; Zhang, Xu; Yan, Ni; Chen, Shengliang; Li, Ying

2012-06-09

Pain contains both sensory and affective dimensions. Using a rodent visceral pain assay that combines the colorectal distension (CRD) model with the conditioned place avoidance (CPA) paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC) activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Progress has been made and suggested that activation of vagal afferents plays a role in the behavioral control nociception and memory storage processes.In human patients, electrical vagus nerve stimulation enhanced retention of verbal learning performance. Cholecystokinin-octapeptide (CCK), which is a gastrointestinal hormone released during feeding, has been shown to enhance memory retention. Mice access to food immediately after training session enhanced memory retention. It has been well demonstrated that CCK acting on vagal afferent fibers mediates various physiological functions. We hypothesize that CCK activation of vagal afferent enhances visceral pain-related affective memory. In the presented study, infusion of CCK-8 at physiological concentration combining with conditional training significantly increased the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, CCK had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593). The physiological implications were further strengthened by the similar effects observed in the rats with duodenal infusion of 5% peptone, which has been shown to induce increases in plasma CCK levels. CCK-8 receptor antagonist CR-1409 or perivagal application of capsaicin abolished the effect of CCK on aversive visceral pain memory, which was consistent with the notion that vagal afferent modulates affective aspects of visceral pain. CCK does not change the nociceptive response (visceral pain

Chemical denervation of the renal artery with vincristine for the treatment of resistant arterial hypertension: first-in-man application.

Science.gov (United States)

Stefanadis, Christodoulos; Toutouzas, Konstantinos; Vlachopoulos, Charalambos; Tsioufis, Costas; Synetos, Andreas; Pietri, Panagiota; Tousoulis, Dimitris; Tsiamis, Eleftherios

2013-01-01

Renal artery denervation has recently emerged as a novel therapy for patients with resistant hypertension. Clinical results from renal sympathetic denervation support the safety and efficacy of this method over a period of 18 months. However, several limitations have been reported. Previous studies have shown that chemical denervation by vincristine is safe and effective in an experimental model. We describe the first-in-man application of chemical denervation with vincristine in a 74-year-old male patient with resistant arterial hypertension.

Renal denervation in the management of resistant hypertension: current evidence and perspectives.

Science.gov (United States)

Jin, Yu; Persu, Alexandre; Staessen, Jan A

2013-09-01

Catheter-based renal denervation has emerged as a novel treatment modality for resistant hypertension. This review summarizes the current evidence on this procedure in treatment of resistant hypertension, limitations of available evidence and questions to be answered. The SYMPLICITY studies showed that renal denervation is feasible in treating resistant hypertension, but failed to provide conclusive evidence on the size and durability of the antihypertensive, renal and sympatholytic effects, as well as the long-term safety. The definition of resistant hypertension was loose in the SYMPLICITY studies and the management of resistant hypertension was suboptimal. Future studies should have a randomized design and enroll truly resistant hypertension patients by excluding secondary hypertension, white-coat hypertension and nonadherent patients. Questions to be addressed by the ongoing and future trials include the long-term efficacy and safety of this procedure, identification of responders and uncovering of the underlying mechanisms. Only well-designed, randomized clinical trials addressing the limitations of the SYMPLICITY studies will be able to demonstrate whether renal denervation is an efficacious treatment modality in resistant hypertension and in which patients. For now, renal denervation remains an experimental procedure and should only be offered to truly resistant hypertensive patients in a research context after careful selection.

Malignant Transformation of Vagal Nerve Schwannoma in to ...

African Journals Online (AJOL)

Vagal schwannomas are benign, rare peripheral nerve sheath tumors in the head and neck region. Some physicians opt to closely observe cases of schwannoma of the neck on an outpatient basis rather than to perform radical surgery. However, there is a possibility, albeit rare, of malignant transformation of a.

Sluggish vagal brake reactivity to physical exercise challenge in children with selective mutism.

Science.gov (United States)

Heilman, Keri J; Connolly, Sucheta D; Padilla, Wendy O; Wrzosek, Marika I; Graczyk, Patricia A; Porges, Stephen W

2012-02-01

Cardiovascular response patterns to laboratory-based social and physical exercise challenges were evaluated in 69 children and adolescents, 20 with selective mutism (SM), to identify possible neurophysiological mechanisms that may mediate the behavioral features of SM. Results suggest that SM is associated with a dampened response of the vagal brake to physical exercise that is manifested as reduced reactivity in heart rate and respiration. Polyvagal theory proposes that the regulation of the vagal brake is a neurophysiological component of an integrated social engagement system that includes the neural regulation of the laryngeal and pharyngeal muscles. Within this theoretical framework, sluggish vagal brake reactivity may parallel an inability to recruit efficiently the structures involved in speech. Thus, the findings suggest that dampened autonomic reactivity during mobilization behaviors may be a biomarker of SM that can be assessed independent of the social stimuli that elicit mutism.

Renal artery and parenchymal changes after renal denervation: assessment by magnetic resonance angiography

Energy Technology Data Exchange (ETDEWEB)

Sanders, Margreet F.; Vink, Eva E.; Blankestijn, Peter J. [University Medical Center Utrecht, Department of Nephrology and Hypertension, PO Box 85500, Utrecht (Netherlands); Doormaal, Pieter Jan van; Habets, Jesse; Vonken, Evert-Jan; Leiner, Tim [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Beeftink, Martine M.A.; Verloop, Willemien L.; Voskuil, Michiel [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Bots, Michiel L. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Fadl Elmula, Fadl Elmula M. [Oslo University Hospital, Department of Internal Medicine and Department of Cardiology, Ullevaal, Oslo (Norway); Hammer, Frank [Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Hoffmann, Pavel [Oslo University Hospital, Section for Interventional Cardiology, Department of Cardiology, Ullevaal, Oslo (Norway); Jacobs, Lotte; Staessen, Jan A. [University of Leuven, Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, Leuven (Belgium); Mark, Patrick B.; Taylor, Alison H. [University of Glasgow, Institute of Cardiovascular and Medical Sciences, Glasgow, Scotland (United Kingdom); Persu, Alexandre; Renkin, Jean [Universite Catholique de Louvain, Pole of Cardiovascular Research, Institut de Recherche Experimentale et Clinique, Brussels (Belgium); Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Cardiology Department, Brussels (Belgium); Roditi, Giles [Glasgow Royal Infirmary, Department of Radiology, Glasgow (United Kingdom); Spiering, Wilko [University Medical Centre Utrecht, Department of Vascular Medicine, Utrecht (Netherlands); Collaboration: on behalf of the European Network COordinating research on Renal Denervation (ENCOReD) Consortium

2017-09-15

Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated. This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma. MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable. We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients. (orig.)

Respiratory sinus arrhythmia in the denervated heart

Czech Academy of Sciences Publication Activity Database

Eisenberger, M.; Halámek, Josef; Jurák, Pavel; Vítovec, J.

2004-01-01

Roč. 105, č. 4 (2004), s. 145 ISSN 0006-9248. [Alpe Adria Cardiology Meeting /12./. 01.05.2004, Cividale del Fuiuli] R&D Projects: GA ČR(CZ) GA102/05/0402 Keywords : denervated heart * RSA * HRV Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

Peakonsul Jaanus Kirikmäe andis teenetemärgi praost Thomas Vagale / Airi Vaga ; foto: Harold Karu

Index Scriptorium Estoniae

Vaga, Airi, 1940-

2008-01-01

President Toomas Hendrik Ilves annetas iseseisvuspäeva puhul USA I praostkonna praostile Thomas Vagale Valgetähe IV klassi teenetemärgi. Teenetemärgi andis Thomas Vagale üle Eesti Vabariigi peakonsul Jaanus Kirikmäe

CT-guided percutaneous radiofrequency denervation of the sacroiliac joint

Energy Technology Data Exchange (ETDEWEB)

Gevargez, A.; Schirp, S.; Braun, M. [Department of Radiology and Microtherapy, University of Witten/Herdecke, Bochum (Germany); Groenemeyer, D. [Department of Radiology and Microtherapy, University of Witten/Herdecke, Bochum (Germany); EFMT Development and Research Center for Microtherapy, Bochum (Germany)

2002-06-01

Defining the origin of low back pain is a challenging task. Among a variety of factors the sacroiliac joint (SIJ) is a possible pain generator, although precise diagnosis is difficult. Joint blocks may reduce pain, but are, in cases, of only temporary effect. This study was conducted to evaluate CT-guided percutaneous radiofrequency denervation of the sacroiliac joint in patients with low back pain. The procedure was performed on 38 patients who only temporarily responded to CT-guided SIJ blocks. The denervation was carried out in the posterior interosseous sacroiliac ligaments and on the dorsal rami of the fifth spinal nerve. All interventions were carried out under CT guidance as out-patient therapies. Three months after the therapy, 13 patients (34.2%) were completely free of pain. Twelve patients (31.6%) reported on a substantial pain reduction, 7 patients (18.4%) had obtained a slight and 3 patients (7.9%) no pain reduction. The data of 3 patients (7.9%) was missing. There were no intra- or postoperative complications. Computed tomography-guided percutaneous radiofrequency denervation of the sacroiliac joint appears safe and effective. The procedure may be a useful therapeutic modality, especially in patients with chronic low back pain, who only temporarily respond to therapeutic blocks. (orig.)

CT-guided percutaneous radiofrequency denervation of the sacroiliac joint

International Nuclear Information System (INIS)

Gevargez, A.; Schirp, S.; Braun, M.; Groenemeyer, D.

2002-01-01

Defining the origin of low back pain is a challenging task. Among a variety of factors the sacroiliac joint (SIJ) is a possible pain generator, although precise diagnosis is difficult. Joint blocks may reduce pain, but are, in cases, of only temporary effect. This study was conducted to evaluate CT-guided percutaneous radiofrequency denervation of the sacroiliac joint in patients with low back pain. The procedure was performed on 38 patients who only temporarily responded to CT-guided SIJ blocks. The denervation was carried out in the posterior interosseous sacroiliac ligaments and on the dorsal rami of the fifth spinal nerve. All interventions were carried out under CT guidance as out-patient therapies. Three months after the therapy, 13 patients (34.2%) were completely free of pain. Twelve patients (31.6%) reported on a substantial pain reduction, 7 patients (18.4%) had obtained a slight and 3 patients (7.9%) no pain reduction. The data of 3 patients (7.9%) was missing. There were no intra- or postoperative complications. Computed tomography-guided percutaneous radiofrequency denervation of the sacroiliac joint appears safe and effective. The procedure may be a useful therapeutic modality, especially in patients with chronic low back pain, who only temporarily respond to therapeutic blocks. (orig.)

Relationship between Vagal Tone, Cortisol, TNF-Alpha, Epinephrine and Negative Affects in Crohn’s Disease and Irritable Bowel Syndrome

Science.gov (United States)

Pellissier, Sonia; Dantzer, Cécile; Mondillon, Laurie; Trocme, Candice; Gauchez, Anne-Sophie; Ducros, Véronique; Mathieu, Nicolas; Toussaint, Bertrand; Fournier, Alicia; Canini, Frédéric; Bonaz, Bruno

2014-01-01

Crohn’s disease (CD) and irritable bowel syndrome (IBS) involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls). The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients). The day prior to the experiment, salivary cortisol was measured at 8∶00 AM and 10∶00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI) and depressive symptoms (CES-D). After 30 min of rest, ECG was recorded for heart rate variability (HRV) analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu) as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r = −0.48; p<0.05) was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r = −0.39; p<0.05). No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology) in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases. PMID

Functional Echomyography: thickness, ecogenicity, contraction and perfusion of the LMN denervated human muscle before and during h-bFES

Directory of Open Access Journals (Sweden)

Riccardo Zanato

2010-03-01

Full Text Available Permanent denervated muscles were evaluated by ultrasound to monitor changes in morphology, thickness, contraction-relaxation kinetics and perfusion due to the electrical stimulation program of the Rise2-Italy project. In a case of monolateral lesion, morphology and ultrasonographic structure of the denervated muscles changed during the period of stimulation from a pattern typical of complete denervation-induced muscle atrophy to a pattern which might be considered “normal” when detected in an old patient. Thickness improved significantly more in the middle third of the denervated muscle, reaching the same value as the contralateral innervated muscle. Contraction-relaxation kinetics, measured by recording the muscle movements during electrical stimulation, showed an abnormal behavior of the chronically denervated muscle during the relaxation phase, which resulted to be significantly longer than in normal muscle. The long-term denervated muscles analyzed with Echo Doppler showed at rest a low resistance arterial flow that became pulsed during and after electrical stimulation. As expected, the ultra sound measured electrical stimulation-induced hyperemia lasted longer than the stimulation period. The higher than normal energy of the delivered electrical stimuli of the Vienna home-based Functional Electrical Stimulation strategy (h-b FES demonstrate that the explored muscles were still almost completely denervated during the one-year of training. In conclusion, this pilot study confirms the usefulness of Functional Echomyography in the follow-up and the positive effects of h-b FES of denervated muscles.

Excitation-contraction coupling and mechano-sensitivity in denervated skeletal muscles

Directory of Open Access Journals (Sweden)

Fabio Francini

2010-09-01

Full Text Available Skeletal muscle atrophy can be defined as a wasting or decrease in muscle mass and muscle force generation owing lack of use, ageing, injury or disease. Thus, the etiology of atrophy can be different. Atrophy in denervated muscle is a consequence of two factors: 1 the complete lack of motoneuron activity inducing the deficiency of neurotransmitter release and 2 the muscles disuse. The balance of the muscular functions depends on extra- and intra-muscular signals. In the balance are involved the excitation-contraction coupling (ECC, local growth factors, Ca2+-dependent and independent intracellular signals, mechano-sensitivity and mechano-transduction that activate Ca2+-dependent signaling proteins and cytoskeleton- nucleus pathways to the nucleus, that regulate the gene expression. Moreover, retrograde signal from intracellular compartments and cytoskeleton to the sarcolemma are additional factors that regulate the muscle function. Proteolytic systems that operate in atrophic muscles progressively reduce the muscle protein content and so the sarcolemma, ECC and the force generation. In this review we will focus on the more relevant changes of the sarcolemma, excitation-contraction coupling, ECC and mechano-transduction evaluated by electrophysiological methods and observed from early- to long-term denervated skeletal muscles. This review put in particular evidence that long-term denervated muscle maintain a sub-population of fibers with ECC and contractile machinery able to be activated, albeit in lesser amounts, by electrical and mechanical stimulation. Accordingly, this provides a potential molecular explanation of the muscle recovery that occurs in response to rehabilitation strategy as transcutaneous electrical stimulation and passive stretching of denervated muscles, which wre developed as a result of empirical clinical observations.

Magnetic resonance imaging patterns of mononeuropathic denervation in muscles with dual innervation

Energy Technology Data Exchange (ETDEWEB)

Sneag, Darryl B.; Lee, Susan C.; Melisaratus, Darius P. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Feinberg, Joseph H. [Physical Medicine and Rehabilitation, Hospital for Special Surgery, New York, NY (United States); Amber, Ian [MedStar Georgetown University Hospital, Department of Radiology, DC, Washington (United States)

2017-12-15

Magnetic resonance imaging (MRI) of mononeuropathy in muscles with dual innervation depicts geographic denervation corresponding to the affected nerve. Knowledge of the normal distribution of a muscle's neural supply is clinically relevant as partial muscle denervation represents a potential imaging pitfall that can be confused with other pathology, such as muscle strain. This article reviews the normal innervation pattern of extremity muscles with dual supply, providing illustrative examples of mononeuropathy affecting such muscles. (orig.)

Magnetic resonance imaging patterns of mononeuropathic denervation in muscles with dual innervation

International Nuclear Information System (INIS)

Sneag, Darryl B.; Lee, Susan C.; Melisaratus, Darius P.; Feinberg, Joseph H.; Amber, Ian

2017-01-01

Magnetic resonance imaging (MRI) of mononeuropathy in muscles with dual innervation depicts geographic denervation corresponding to the affected nerve. Knowledge of the normal distribution of a muscle's neural supply is clinically relevant as partial muscle denervation represents a potential imaging pitfall that can be confused with other pathology, such as muscle strain. This article reviews the normal innervation pattern of extremity muscles with dual supply, providing illustrative examples of mononeuropathy affecting such muscles. (orig.)

Cardiac vagal tone, a non-invasive measure of parasympathetic tone, is a clinically relevant tool in Type 1 diabetes mellitus

DEFF Research Database (Denmark)

Brock, C; Jessen, N; Brock, B

2017-01-01

AIMS: To compare a novel index of parasympathetic tone, cardiac vagal tone, with established autonomic variables and to test the hypotheses that (1) cardiac vagal tone would be associated with established time and frequency domain measures of heart rate and (2) cardiac vagal tone would be lower...... identification of people with Type 1 diabetes who should undergo formal autonomic function testing....

Dexmedetomidine decreases inhibitory but not excitatory neurotransmission to cardiac vagal neurons in the nucleus ambiguus.

Science.gov (United States)

Sharp, Douglas B; Wang, Xin; Mendelowitz, David

2014-07-29

Dexmedetomidine, an α2 adrenergic agonist, is a useful sedative but can also cause significant bradycardia. This decrease in heart rate may be due to decreased central sympathetic output as well as increased parasympathetic output from brainstem cardiac vagal neurons. In this study, using whole cell voltage clamp methodology, the actions of dexmedetomidine on excitatory glutamatergic and inhibitory GABAergic and glycinergic neurotransmission to parasympathetic cardiac vagal neurons in the rat nucleus ambiguus was determined. The results indicate that dexmedetomidine decreases both GABAergic and glycinergic inhibitory input to cardiac vagal neurons, with no significant effect on excitatory input. These results provide a mechanism for dexmedetomidine induced bradycardia and has implications for the management of this potentially harmful side effect. Copyright © 2014 Elsevier B.V. All rights reserved.

Advanced age-related denervation and fiber-type grouping in skeletal muscle of SOD1 knockout mice.

Science.gov (United States)

Kostrominova, Tatiana Y

2010-11-30

In this study skeletal muscles from 1.5- and 10-month-old Cu/Zn superoxide dismutase (SOD1) homozygous knockout (JLSod1(-/-)) mice obtained from The Jackson Laboratory (C57Bl6/129SvEv background) were compared with muscles from age- and sex-matched heterozygous (JLSod1(+/-)) littermates. The results of this study were compared with previously published data on two different strains of Sod1(-/-) mice: one from Dr. Epstein's laboratory (ELSod1(-/-); C57Bl6 background) and the other from Cephalon, Inc. (CSod1(-/-); 129/CD-1 background). Grouping of succinate dehydrogenase-positive fibers characterized muscles of Sod1(-/-) mice from all three strains. The 10-month-old Sod1(-/-)C and JL mice displayed pronounced denervation of the gastrocnemius muscle, whereas the ELSod1(-/-) mice displayed a small degree of denervation at this age, but developed accelerated age-related denervation later on. Denervation markers were up-regulated in skeletal muscle of 10-month-old JLSod1(-/-) mice. This study is the first to show that metallothionein mRNA and protein expression was up-regulated in the skeletal muscle of 10-month-old JLSod1(-/-) mice and was mostly localized to the small atrophic muscle fibers. In conclusion, all three strains of Sod1(-/-) mice develop accelerated age-related muscle denervation, but the genetic background has significant influence on the progress of denervation. Copyright © 2010 Elsevier Inc. All rights reserved.

MRI diagnosis of muscle denervation from herpes zoster with discordant distribution of the skin rash

Energy Technology Data Exchange (ETDEWEB)

Gupta, Amit; Sundaram, Murali [Cleveland Clinic, Section of Musculoskeletal Radiology, Imaging Institute, Cleveland, OH (United States); Winalski, Carl S. [Cleveland Clinic, Section of Musculoskeletal Radiology, Imaging Institute, Cleveland, OH (United States); Cleveland Clinic, Department of Biomedical Engineering, Lerner Research Institute, Cleveland, OH (United States)

2014-10-15

Herpes zoster is a common disorder characterized by a painful rash along a dermatome caused by reactivation of the varicella zoster virus (VZV). Muscle denervation injury from motor involvement is an uncommon phenomenon. Discordant distribution of the skin rash and motor nerve involvement, presenting as a skin rash in one body part and muscle weakness or pain from nerve involvement in another body part is an even more uncommonly reported finding. We present an unusual case of muscle denervation injury resulting from motor involvement of a peripheral nerve by VZV diagnosed by magnetic resonance imaging with cutaneous manifestations in a different dermatomal distribution. To the best of our knowledge, there has been no similar case reported in the English radiology literature. We suggest that whenever a radiologist notices MRI findings suggesting denervation injury and a cause not readily identified, VZV-related denervation injury should be included in the differential diagnosis, especially in an older immunocompromised patient. (orig.)

Renal denervation attenuates NADPH oxidase-mediated oxidative stress and hypertension in rats with hydronephrosis.

Science.gov (United States)

Peleli, Maria; Al-Mashhadi, Ammar; Yang, Ting; Larsson, Erik; Wåhlin, Nils; Jensen, Boye L; G Persson, A Erik; Carlström, Mattias

2016-01-01

Hydronephrosis is associated with the development of salt-sensitive hypertension. Studies have suggested that increased sympathetic nerve activity and oxidative stress play important roles in hypertension and the modulation of salt sensitivity. The present study primarily aimed to examine the role of renal sympathetic nerve activity in the development of hypertension in rats with hydronephrosis. In addition, we aimed to investigate if NADPH oxidase (NOX) function could be affected by renal denervation. Partial unilateral ureteral obstruction (PUUO) was created in 3-wk-old rats to induce hydronephrosis. Sham surgery or renal denervation was performed at the same time. Blood pressure was measured during normal, high-, and low-salt diets. The renal excretion pattern, NOX activity, and expression as well as components of the renin-angiotensin-aldosterone system were characterized after treatment with the normal salt diet. On the normal salt diet, rats in the PUUO group had elevated blood pressure compared with control rats (115 ± 3 vs. 87 ± 1 mmHg, P < 0.05) and displayed increased urine production and lower urine osmolality. The blood pressure change in response to salt loading (salt sensitivity) was more pronounced in the PUUO group compared with the control group (15 ± 2 vs. 5 ± 1 mmHg, P < 0.05). Renal denervation in PUUO rats attenuated both hypertension (97 ± 3 mmHg) and salt sensitivity (5 ± 1 mmHg, P < 0.05) and normalized the renal excretion pattern, whereas the degree of renal fibrosis and inflammation was not changed. NOX activity and expression as well as renin and ANG II type 1A receptor expression were increased in the renal cortex from PUUO rats and normalized by denervation. Plasma Na(+) and K(+) levels were elevated in PUUO rats and normalized after renal denervation. Finally, denervation in PUUO rats was also associated with reduced NOX expression, superoxide production, and fibrosis in the heart. In conclusion, renal denervation attenuates

Vagal withdrawal during endoscopic retrograde cholangiopancreatography

DEFF Research Database (Denmark)

Christensen, M; Rasmussen, Verner; Schulze, S

2000-01-01

BACKGROUND: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) are at risk of developing cardiorespiratory complications, but the mechanism is still unknown. Treatment with metoprolol 2 h before the endoscopy has been shown to decrease the incidence of myocardial ischaemia......: The existence of a defence-like reaction ('vagal withdrawal') during ERCP has been shown. Metoprolol given 2 h before the procedure did not affect the occurrence of this phenomenon. The interaction of other periendoscopic factors is still unclear and should be studied further....

Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

Science.gov (United States)

McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

2014-01-01

Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

Renal denervation in an animal model of diabetes and hypertension: Impact on the autonomic nervous system and nephropathy

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Machado Ubiratan F

2011-04-01

Full Text Available Abstract Background The effects of renal denervation on cardiovascular reflexes and markers of nephropathy in diabetic-hypertensive rats have not yet been explored. Methods Aim: To evaluate the effects of renal denervation on nephropathy development mechanisms (blood pressure, cardiovascular autonomic changes, renal GLUT2 in diabetic-hypertensive rats. Forty-one male spontaneously hypertensive rats (SHR ~250 g were injected with STZ or not; 30 days later, surgical renal denervation (RD or sham procedure was performed; 15 days later, glycemia and albuminuria (ELISA were evaluated. Catheters were implanted into the femoral artery to evaluate arterial pressure (AP and heart rate variability (spectral analysis one day later in conscious animals. Animals were killed, kidneys removed, and cortical renal GLUT2 quantified (Western blotting. Results Higher glycemia (p vs. nondiabetics (p vs. SHR. Conclusions Renal denervation in diabetic-hypertensive rats improved previously reduced heart rate variability. The GLUT2 equally overexpressed by diabetes and renal denervation may represent a maximal derangement effect of each condition.

A model-based approach for the evaluation of vagal and sympathetic activities in a newborn lamb.

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Le Rolle, Virginie; Ojeda, David; Beuchée, Alain; Praud, Jean-Paul; Pladys, Patrick; Hernández, Alfredo I

2013-01-01

This paper proposes a baroreflex model and a recursive identification method to estimate the time-varying vagal and sympathetic contributions to heart rate variability during autonomic maneuvers. The baroreflex model includes baroreceptors, cardiovascular control center, parasympathetic and sympathetic pathways. The gains of the global afferent sympathetic and vagal pathways are identified recursively. The method has been validated on data from newborn lambs, which have been acquired during the application of an autonomic maneuver, without medication and under beta-blockers. Results show a close match between experimental and simulated signals under both conditions. The vagal and sympathetic contributions have been simulated and, as expected, it is possible to observe different baroreflex responses under beta-blockers compared to baseline conditions.

Therapeutic effect of radiofrequency ablation on children with supraventricular tachycardia and the risk factors for postoperative recurrence.

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Li, Chunli; Jia, Libo; Wang, Zhenzhou; Niu, Ling; An, Xinjiang

2018-05-01

The present study investigated the therapeutic effect of radiofrequency ablation on children with supraventricular tachycardia (SVT), and explored the risk factors for postoperative recurrence. A total of 312 patients with pediatric SVT were selected in the Affiliated Children's Hospital of Xuzhou Medical University from April, 2011 to March, 2017. All the patients were subjected to radiofrequency ablation, and clinical data were retrospectively analyzed. Tilt table test was performed before and after treatment, and heart rate, systolic and diastolic blood pressure before and after treatment were compared. Plasma levels of D-dimer (D-D), platelet α-granule membrane protein (GMP-140) and thrombin-antithrombin III complex (TAT) were detected by enzyme-linked immunosorbent assay before treatment, immediately after radiofrequency oblation, and at 1, 3 and 7 days after treatment. Treatment outcomes were compared between the atrioventricular reentrant tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) groups. Risk factors for postoperative recurrence were analyzed. Supine position heart rate after treatment was not significantly different from that before treatment (P>0.05), while the upright position heart rate was significantly increased after treatment (P0.05). No significant difference in radiofrequency ablation rate, recurrence rate and incidence of complications were found between the AVRT and AVNRT groups (P>0.05). After radiofrequency, the levels of D-D, GMP-140 and TAT ablation showed an upward trend, but decreased at day 7 to reach preoperative levels. Logistic regression analysis revealed that residual slow pathway (OR=6.718, P=0.005) and inaccurate targeting (OR=2.815, P=0.007) were independent risk factors for postoperative recurrence (Pradiofrequency ablation can damage the cardiac vagal nerve, resulting in an increase in the heart rate after ablation during the course of the tilt table test and changed hemagglutination state

Ultra structure of the denervated vocal muscle mechanically in hogs (sus scrofa domestica

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Leão, Henrique Zaquia

2010-03-01

Full Text Available Introduction: The literature is not clear in the ultra-structural manifestations of the vocal wrinkles after neural wound. Objective: To verify the alterations that occur in a vocal fold mechanically denervated. Method: In this prospective study, it were utilized 15 hogs of commercial race (Sus scrofa domesticates, with age of 4 to 12 weeks. The animals were distributed in three groups, chosen at random. Everybody was submitted to the denervation of the right vocal fold, with surgical removal of a segment with three centimeters of the recurring right laryngeal nerve. After 45, 90 and 180 days of the operations, it was proceeded the biopsy of the vocal muscles, it was prosecuted the samples for transmission electron microscopy and, for the ultra-structural study, utilized the transmission electron microscopy Philips, model EM208S. Results: The biopsied groups with 45 and 90 days after operation of mechanical denervation, presented disorganization miofibrilar, only vestigial lines Z in many samples, as well like altered mithochondrions presenting limited sizes, and matrix mithocondrial rarefied with rare mithocondrial cristae present. The biopsied group with 180 days after operation of denervation, presented regular sarcomeres, mithocondrions with sizes and regular number with correct positioning between the sarcomerical units. Conclusion: The finds in the ultra-structure of the vocal muscles suggest to re enervation of the muscle being that the muscular mithochondrions were the most sensible structures to the denervated condition, successions by the cytoarchiteture of the miofibrilas; the finds in the ultra-structure of the vocal muscles suggests to reinervation of the muscle in the period of approximately six months.

Neonatal capsaicin causes compensatory adjustments to energy homeostasis in rats

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van de Wall, E. H. E. M.; Wielinga, P. Y.; Strubbe, J. H.; van Dijk, G.

2006-01-01

Several mechanisms involved in ingestive behavior and neuroendocrine activity rely on vagal afferent neuronal signaling. Seemingly contradictory to this idea are observations that vagal afferent neuronal ablation by neonatal capsaicin (CAP) treatment has relatively small effects on glucose

Renal denervation for resistant hypertension and beyond.

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Laffin, Luke J; Bakris, George L

2015-03-01

Despite the availability of more than 125 approved antihypertensive medications, 36 million (48%) of 75 million people with hypertension, including 16 million treated with antihypertensive medications in the United States, do not achieve guideline blood pressure goals known to reduce cardiovascular morbidity and mortality and progression of kidney disease; 3% to 6% of these 75 million hypertensive individuals are estimated to have resistant hypertension. A major contributing factor for poor blood pressure control, besides inadequate diuretic therapy, is failure of antihypertensive agents to inhibit the sympathetic nervous system effectively. Consequently, alternative device-driven approaches have been developed. Recent technical advances targeting renal sympathetic nerves, that is, renal denervation therapy, are the focus of more invasive therapies to treat resistant hypertension. Encouraging results from the SYMPLICITY HTN-2 trial, regarding efficacy and safety of renal denervation therapy, were countered by disappointing efficacy results of SYMPLICITY HTN-3. Reasons for these divergent results and the future of the field are discussed. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Cholecystokinin regulates satiation idependently of the abdominal vagal nerve in a pig model of total subdiaphragmatic vagotomy

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Ripken, D.; Wielen, van der N.; Meulen, van der J.; Schuurman, T.; Witkamp, R.F.; Hendriks, H.F.J.; Koopmans, S.J.

2015-01-01

The vagal nerve and gut hormones CCK and GLP-1 play important roles in the control of food intake. However, it is not clear to what extent CCK and GLP-1 increase satiation by stimulating receptors located on abdominal vagal nerve endings or via receptors located elsewhere. This study aimed to

Cholecystokinin regulates satiation independently of the abdominal vagal nerve in a pig model of total subdiaphragmatic vagotomy

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Ripken, D.; Wielen, N. van der; Meulen, J. van der; Schuurman, T.; Witkamp, R.F.; Hendriks, H.F.J.; Koopmans, S.J.

2015-01-01

The vagal nerve and gut hormones CCK and GLP-1 play important roles in the control of food intake. However, it is not clear to what extent CCK and GLP-1 increase satiation by stimulating receptors located on abdominal vagal nerve endings or via receptors located elsewhere. This study aimed to

[Renal denervation for the treatment of resistant hypertension: definition, patient selection and description of the procedure. 2012 Position paper of the Italian Society of Hypertension].

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Volpe, Massimo; Agabiti-Rosei, Enrico; Ambrosioni, Ettore; Cottone, Santina; Cuspidi, Cesare; Borghi, Claudio; De Luca, Nicola; Fallo, Francesco; Ferri, Claudio; Mancia, Giuseppe; Morganti, Alberto; Muiesan, Maria Lorenza; Sarzani, Riccardo; Sechi, Leonardo; Tocci, Giuliano; Virdis, Agostino

2012-12-01

Hypertension is responsible for a relevant burden of cardiovascular morbidity and mortality worldwide. Although several appropriate and integrated pharmacological strategies are available, blood pressure control still remains largely unsatisfactory. Failure to achieve effective blood pressure control in treated hypertensive patients may have a substantial impact on overall cardiovascular risk, since it significantly increases the risk of both macrovascular and microvascular complications. Hypertension is arbitrarily defined as "resistant" or "refractory" when recommended blood pressure goals (clinic blood pressure hypertension has recently become available. Renal sympathetic denervation is a minimally invasive procedure performed via femoral access that uses radiofrequency catheter ablation to disable renal sympathetic afferent and efferent nerves. It results in isolation of renal parenchymal and juxtaglomerular cells from the abnormal enhancement of renal adrenergic nerve activity. The present position paper of the Italian Society of Hypertension provides a diagnostic and therapeutic approach to the early identification and effective clinical management of patients with resistant hypertension, who may be candidates for renal denervation. These indications may have important implications not only from a clinical viewpoint but also from an economic perspective. The accurate identification of patients with resistant hypertension and the appropriate selection of patients eligible for this procedure may help improve blood pressure control and reduce the risk of cardiovascular and cerebrovascular complications in these patients.

Blood pressure response to catheter-based renal sympathetic denervation in severe resistant hypertension: data from the Greek Renal Denervation Registry.

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Tsioufis, C; Ziakas, A; Dimitriadis, K; Davlouros, P; Marketou, M; Kasiakogias, A; Thomopoulos, C; Petroglou, D; Tsiachris, D; Doumas, M; Skalidis, E; Karvounis, C; Alexopoulos, D; Vardas, P; Kallikazaros, I; Stefanadis, C; Papademetriou, V; Tousoulis, D

2017-05-01

The efficacy of catheter-based renal sympathetic denervation (RDN) in terms of blood pressure (BP) reduction has been questioned, while "real-world" data from registries are needed. In this study, we report the complete set of 12-month data on office and ambulatory BP changes as well as the predictors for BP response to RDN from a national registry. In 4 Greek hospital centers, 79 patients with severe drug-resistant hypertension (age 59 ± 10 years, 53 males, body mass index 33 ± 5 kg/m 2 ; office BP and 24-h ambulatory BP were 176 ± 15/95 ± 13 and 155 ± 14/90 ± 12 mmHg, respectively, 4.4 ± 0.9 antihypertensive drugs) underwent RDN and were followed-up for 12 months in the Greek Renal Denervation Registry. Bilateral RDN was performed using percutaneous femoral approach and standardized techniques. Reduction in office systolic/diastolic BP at 6 and 12 months from baseline was -30/-12 and -29/-12 mmHg, while the reduction in 24-h ambulatory BP was -16/-9 and -15/-9 mmHg, respectively (p renal function and any new serious device or procedure-related adverse events. In our "real-world" multicenter national registry, the efficacy of renal denervation in reducing BP as well as safety is confirmed during a 12-month follow-up. Moreover, younger age, obesity, and higher levels of baseline systolic BP are independently related to better BP response to RDN.

Improved sphincter contractility after allogenic muscle-derived progenitor cell injection into the denervated rat urethra.

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Cannon, Tracy W; Lee, Ji Youl; Somogyi, George; Pruchnic, Ryan; Smith, Christopher P; Huard, Johnny; Chancellor, Michael B

2003-11-01

To study the physiologic outcome of allogenic transplant of muscle-derived progenitor cells (MDPCs) in the denervated female rat urethra. MDPCs were isolated from muscle biopsies of normal 6-week-old Sprague-Dawley rats and purified using the preplate technique. Sciatic nerve-transected rats were used as a model of stress urinary incontinence. The experimental group was divided into three subgroups: control, denervated plus 20 microL saline injection, and denervated plus allogenic MDPCs (1 to 1.5 x 10(6) cells) injection. Two weeks after injection, urethral muscle strips were prepared and underwent electrical field stimulation. The pharmacologic effects of d-tubocurare, phentolamine, and tetrodotoxin on the urethral strips were assessed by contractions induced by electrical field stimulation. The urethral tissues also underwent immunohistochemical staining for fast myosin heavy chain and CD4-activated lymphocytes. Urethral denervation resulted in a significant decrease of the maximal fast-twitch muscle contraction amplitude to only 8.77% of the normal urethra and partial impairment of smooth muscle contractility. Injection of MDPCs into the denervated sphincter significantly improved the fast-twitch muscle contraction amplitude to 87.02% of normal animals. Immunohistochemistry revealed a large amount of new skeletal muscle fiber formation at the injection site of the urethra with minimal inflammation. CD4 staining showed minimal lymphocyte infiltration around the MDPC injection sites. Urethral denervation resulted in near-total abolishment of the skeletal muscle and partial impairment of smooth muscle contractility. Allogenic MDPCs survived 2 weeks in sciatic nerve-transected urethra with minimal inflammation. This is the first report of the restoration of deficient urethral sphincter function through muscle-derived progenitor cell tissue engineering. MDPC-mediated cellular urethral myoplasty warrants additional investigation as a new method to treat stress urinary

Roles for gut vagal sensory signals in determining energy availability and energy expenditure.

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Schwartz, Gary J

2018-08-15

The gut sensory vagus transmits a wide range of meal-related mechanical, chemical and gut peptide signals from gastrointestinal and hepatic tissues to the central nervous system at the level of the caudal brainstem. Results from studies using neurophysiological, behavioral physiological and metabolic approaches that challenge the integrity of this gut-brain axis support an important role for these gut signals in the negative feedback control of energy availability by limiting food intake during a meal. These experimental approaches have now been applied to identify important and unanticipated contributions of the vagal sensory gut-brain axis to the control of two additional effectors of overall energy balance: the feedback control of endogenous energy availability through hepatic glucose production and metabolism, and the control of energy expenditure through brown adipose tissue thermogenesis. Taken together, these studies reveal the pleiotropic influences of gut vagal meal-related signals on energy balance, and encourage experimental efforts aimed at understanding how the brainstem represents, organizes and coordinates gut vagal sensory signals with these three determinants of energy homeostasis. Copyright © 2018 Elsevier B.V. All rights reserved.

Renal Denervation for Treating Resistant Hypertension: Current Evidence and Future Insights from a Global Perspective

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Y. Castro Torres

2013-01-01

Full Text Available Adequate blood pressure control represents an important goal for all physicians due to the complications of hypertension which reduce patients' quality of life. A new interventional strategy to reduce blood pressure has been developed for patients with resistant hypertension. Catheter-based renal denervation has demonstrated excellent results in recent investigations associated with few side effects. With the growing diffusion of this technique worldwide, some medical societies have published consensus statements to guide physicians how to best apply this procedure. Questions remain to be answered such as the long-term durability of renal denervation, the efficacy in patients with other sympathetically mediated diseases, and whether renal denervation would benefit patients with stage 1 hypertension.

Muscular hypertrophy and atrophy in normal rats provoked by the administration of normal and denervated muscle extracts.

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Agüera, Eduardo; Castilla, Salvador; Luque, Evelio; Jimena, Ignacio; Leiva-Cepas, Fernando; Ruz-Caracuel, Ignacio; Peña, José

2016-12-01

This study was conducted to determine the effects of extracts obtained from both normal and denervated muscles on different muscle types. Wistar rats were used and were divided into a control group and four experimental groups. Each experimental group was treated intraperitoneally during 10 consecutive days with a different extract. These extracts were obtained from normal soleus muscle, denervated soleus, normal extensor digitorum longus, and denervated extensor digitorum longus. Following treatment, the soleus and extensor digitorum longus muscles were obtained for study under optic and transmission electron microscope; morphometric parameters and myogenic responses were also analyzed. The results demonstrated that the treatment with normal soleus muscle and denervated soleus muscle extracts provoked hypertrophy and increased myogenic activity. In contrast, treatment with extracts from the normal and denervated EDL had a different effect depending on the muscle analyzed. In the soleus muscle it provoked hypertrophy of type I fibers and increased myogenic activity, while in the extensor digitorum longus atrophy of the type II fibers was observed without changes in myogenic activity. This suggests that the muscular responses of atrophy and hypertrophy may depend on different factors related to the muscle type which could be related to innervation.

Meal parameters and vagal gastrointestinal afferents in mice that experienced early postnatal overnutrition.

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Biddinger, Jessica E; Fox, Edward A

2010-08-04

Early postnatal overnutrition results in a predisposition to develop obesity due in part to hypothalamic and sympathetic dysfunction. Potential involvement of another major regulatory system component--the vagus nerve--has not been examined. Moreover, feeding disturbances have rarely been investigated prior to development of obesity when confounds due to obesity are minimized. To examine these issues, litters were culled on the day of birth to create small litters (SL; overnutrition), or normal size litters (NL; normal nutrition). Body weight, fat pad weight, meal patterns, and vagal sensory duodenal innervation were compared between SL and NL adult mice prior to development of obesity. Meal patterns were studied 18 h/day for 3 weeks using a balanced diet. Then vagal mechanoreceptors were labeled using anterograde transport of wheatgerm agglutinin-horseradish peroxidase injected into the nodose ganglion and their density and morphology were examined. Between postnatal day 1 and weaning, body weight of SL mice was greater than for NL mice. By young adulthood it was similar in both groups, whereas SL fat pad weight was greater in males, suggesting postnatal overnutrition produced a predisposition to obesity. SL mice exhibited increased food intake, decreased satiety ratio, and increased first meal rate (following mild food deprivation) compared to NL mice, suggesting postnatal overnutrition disrupted satiety. The density and structure of intestinal IGLEs appeared similar in SL and NL mice. Thus, although a vagal role cannot be excluded, our meal parameter and anatomical findings provided no evidence for significant postnatal overnutrition effects on vagal gastrointestinal afferents. Copyright 2010 Elsevier Inc. All rights reserved.

Side-To-Side Nerve Bridges Support Donor Axon Regeneration Into Chronically Denervated Nerves and Are Associated With Characteristic Changes in Schwann Cell Phenotype.

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Hendry, J Michael; Alvarez-Veronesi, M Cecilia; Snyder-Warwick, Alison; Gordon, Tessa; Borschel, Gregory H

2015-11-01

Chronic denervation resulting from long nerve regeneration times and distances contributes greatly to suboptimal outcomes following nerve injuries. Recent studies showed that multiple nerve grafts inserted between an intact donor nerve and a denervated distal recipient nerve stump (termed "side-to-side nerve bridges") enhanced regeneration after delayed nerve repair. To examine the cellular aspects of axon growth across these bridges to explore the "protective" mechanism of donor axons on chronically denervated Schwann cells. In Sprague Dawley rats, 3 side-to-side nerve bridges were placed over a 10-mm distance between an intact donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) distal nerve stump. Green fluorescent protein-expressing TIB axons grew across the bridges and were counted in cross section after 4 weeks. Immunofluorescent axons and Schwann cells were imaged over a 4-month period. Denervated Schwann cells dedifferentiated to a proliferative, nonmyelinating phenotype within the bridges and the recipient denervated CP nerve stump. As donor TIB axons grew across the 3 side-to-side nerve bridges and into the denervated CP nerve, the Schwann cells redifferentiated to the myelinating phenotype. Bridge placement led to an increased mass of hind limb anterior compartment muscles after 4 months of denervation compared with muscles whose CP nerve was not "protected" by bridges. This study describes patterns of donor axon regeneration and myelination in the denervated recipient nerve stump and supports a mechanism where these donor axons sustain a proregenerative state to prevent deterioration in the face of chronic denervation.

Peripheral denervation participates in heterotopic ossification in a spinal cord injury model.

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Charlotte Debaud

Full Text Available We previously reported the development of a new acquired neurogenic HO (NHO mouse model, combining spinal cord transection (SCI and chemical muscle injury. Pathological mechanisms responsible for ectopic osteogenesis after central neurological damage are still to be elucidated. In this study, we first hypothesized that peripheral nervous system (PNS might convey pathological signals from injured spinal cord to muscles in NHO mouse model. Secondly, we sought to determine whether SCI could lead to intramuscular modifications of BMP2 signaling pathways. Twenty one C57Bl6 mice were included in this protocol. Bilateral cardiotoxin (CTX injection in hamstring muscles was associated with a two-stage surgical procedure, combining thoracic SCI with unilateral peripheral denervation. Volumes of HO (Bone Volume, BV were measured 28 days after surgery using micro-computed tomography imaging techniques and histological analyses were made to confirm intramuscular osteogenesis. Volume comparisons were conducted between right and left hind limb of each animal, using a Wilcoxon signed rank test. Quantitative polymerase chain reaction (qPCR was performed to explore intra muscular expression of BMP2, Alk3 and Id1. Nineteen mice survive the complete SCI and peripheral denervation procedure. When CTX injections were done right after surgery (n = 7, bilateral HO were detected in all animals after 28 days. Micro-CT measurements showed significantly increased BV in denervated paws (1.47 mm3 +/- 0.5 compared to contralateral sides (0.56 mm3 +/-0.4, p = 0.03. When peripheral denervation and CTX injections were performed after sham SCI surgery (n = 6, bilateral HO were present in three mice at day 28. Quantitative PCR analyses showed no changes in intra muscular BMP2 expression after SCI as compared to control mice (shamSCI. Peripheral denervation can be reliably added to spinal cord transection in NHO mouse model. This new experimental design confirms that neuro

Functional recovery of denervated skeletal muscle with sensory or mixed nerve protection: a pilot study.

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Qing Tian Li

Full Text Available Functional recovery is usually poor following peripheral nerve injury when reinnervation is delayed. Early innervation by sensory nerve has been indicated to prevent atrophy of the denervated muscle. It is hypothesized that early protection with sensory axons is adequate to improve functional recovery of skeletal muscle following prolonged denervation of mixed nerve injury. In this study, four groups of rats received surgical denervation of the tibial nerve. The proximal and distal stumps of the tibial nerve were ligated in all animals except for those in the immediate repair group. The experimental groups underwent denervation with nerve protection of peroneal nerve (mixed protection or sural nerve (sensory protection. The experimental and unprotected groups had a stage II surgery in which the trimmed proximal and distal tibial nerve stumps were sutured together. After 3 months of recovery, electrophysiological, histological and morphometric parameters were assessed. It was detected that the significant muscle atrophy and a good preserved structure of the muscle were observed in the unprotected and protective experimental groups, respectively. Significantly fewer numbers of regenerated myelinated axons were observed in the sensory-protected group. Enhanced recovery in the mixed protection group was indicated by the results of the muscle contraction force tests, regenerated myelinated fiber, and the results of the histological analysis. Our results suggest that early axons protection by mixed nerve may complement sensory axons which are required for promoting functional recovery of the denervated muscle natively innervated by mixed nerve.

Less Empathic and More Reactive: The Different Impact of Childhood Maltreatment on Facial Mimicry and Vagal Regulation.

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Martina Ardizzi

Full Text Available Facial mimicry and vagal regulation represent two crucial physiological responses to others' facial expressions of emotions. Facial mimicry, defined as the automatic, rapid and congruent electromyographic activation to others' facial expressions, is implicated in empathy, emotional reciprocity and emotions recognition. Vagal regulation, quantified by the computation of Respiratory Sinus Arrhythmia (RSA, exemplifies the autonomic adaptation to contingent social cues. Although it has been demonstrated that childhood maltreatment induces alterations in the processing of the facial expression of emotions, both at an explicit and implicit level, the effects of maltreatment on children's facial mimicry and vagal regulation in response to facial expressions of emotions remain unknown. The purpose of the present study was to fill this gap, involving 24 street-children (maltreated group and 20 age-matched controls (control group. We recorded their spontaneous facial electromyographic activations of corrugator and zygomaticus muscles and RSA responses during the visualization of the facial expressions of anger, fear, joy and sadness. Results demonstrated a different impact of childhood maltreatment on facial mimicry and vagal regulation. Maltreated children did not show the typical positive-negative modulation of corrugator mimicry. Furthermore, when only negative facial expressions were considered, maltreated children demonstrated lower corrugator mimicry than controls. With respect to vagal regulation, whereas maltreated children manifested the expected and functional inverse correlation between RSA value at rest and RSA response to angry facial expressions, controls did not. These results describe an early and divergent functional adaptation to hostile environment of the two investigated physiological mechanisms. On the one side, maltreatment leads to the suppression of the spontaneous facial mimicry normally concurring to empathic understanding of

Nikolaus Rüdinger (1832-1896), His Description of Joint Innervation in 1857, and the History of Surgical Joint Denervation.

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Gohritz, Andreas; Kaiser, Erich; Guggenheim, Merlin; Dellon, Arnold Lee

2018-01-01

 Selective joint denervation has become a reliable palliative treatment, especially for painful joints in the upper and lower extremity.  This article highlights the life and work of Nikolaus Rüdinger (1832-1896) who first described joint innervation which became the basis of later techniques of surgical joint denervation. The historical evolution of this method is outlined.  Rüdinger made a unique career from apprentice barber to military surgeon and anatomy professor in Munich, Germany. His first description of articular innervation of temporomandibular, shoulder, elbow, wrist, finger, sacroiliac, hip, knee, ankle, foot, and toe joints in 1857 stimulated the subsequent history of surgical joint denervation. Comparing his investigations with modern joint denervation methods, developed by pioneers like Albrecht Wilhelm or A. Lee Dellon, shows his great exactitude and anatomical correspondence despite different current terminology. Clinical series of modern surgical joint denervations reveal success rates of up to 80% with reliable long-term results.  The history of joint denervation with Rüdinger as its important protagonist offers inspiring insights into the evolution of surgical techniques and exemplifies the value of descriptive functional anatomy, even if surgical application may not have been realized until a century later. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Resection of cervical vagal schwannoma via a post-auricular approach.

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Roh, Jong-Lyel

2006-03-01

Cervical vagal schwannomas are extremely rare and gross total resection is the standard treatment modality. However, because the conventional cervical approach leaves an incision scar in a visible area, other approaches need to be developed for young women who want the postoperative scar to be invisible. A 28-year-old female underwent complete resection of a 4x4 cm tumor in her right upper neck via a post-auricular approach using an inverted V-shaped incision along the post-auricular sulcus and hairline. The tumor was a schwannoma originating from the right cervical vagus nerve. Postoperatively, right vocal cord paralysis developed despite careful dissection but completely recovered within 6 months after surgery. The patient was satisfied with an invisible external scar which was hidden by her auricle and hair. A cervical vagal schwannoma can be successfully removed by making an incision in a potentially invisible area.

Anatomical and procedural determinants of catheter-based renal denervation

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Ewen, Sebastian; Ukena, Christian; Lüscher, Thomas Felix; Bergmann, Martin; Blankestijn, Peter J; Blessing, Erwin; Cremers, Bodo; Dörr, Oliver; Hering, Dagmara; Kaiser, Lukas; Nef, Holger; Noory, Elias; Schlaich, Markus; Sharif, Faisal; Sudano, Isabella; Vogel, Britta; Voskuil, Michiel; Zeller, Thomas; Tzafriri, Abraham R; Edelman, Elazer R; Lauder, Lucas; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2016-01-01

BACKGROUND/PURPOSE: Catheter-based renal sympathetic denervation (RDN) can reduce blood pressure (BP) and sympathetic activity in certain patients with uncontrolled hypertension. Less is known about the impact of renal anatomy and procedural parameters on subsequent BP response. METHODS/MATERIALS: A

Cooled radiofrequency denervation for treatment of sacroiliac joint pain: two-year results from 20 cases

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Ho, Kok-Yuen; Hadi, Mohamed Abdul; Pasutharnchat, Koravee; Tan, Kian-Hian

2013-01-01

Background Sacroiliac joint pain is a common cause of chronic low back pain. Different techniques for radiofrequency denervation of the sacroiliac joint have been used to treat this condition. However, results have been inconsistent because the variable sensory supply to the sacroiliac joint is difficult to disrupt completely using conventional radiofrequency. Cooled radiofrequency is a novel technique that uses internally cooled radiofrequency probes to enlarge lesion size, thereby increasing the chance of completely denervating the sacroiliac joint. The objective of this study was to evaluate the efficacy of cooled radiofrequency denervation using the SInergy™ cooled radiofrequency system for sacroiliac joint pain. Methods The charts of 20 patients with chronic sacroiliac joint pain who had undergone denervation using the SInergy™ cooled radiofrequency system were reviewed at two years following the procedure. Outcome measures included the Numeric Rating Scale for pain intensity, Patient Global Impression of Change, and Global Perceived Effect for patient satisfaction. Results Fifteen of 20 patients showed a significant reduction in pain (a decrease of at least three points on the Numeric Rating Scale). Mean Numeric Rating Scale for pain decreased from 7.4 ± 1.4 to 3.1 ± 2.5, mean Patient Global Impression of Change was “improved” (1.4 ± 1.5), and Global Perceived Effect was reported to be positive in 16 patients at two years following the procedure. Conclusion Cooled radiofrequency denervation showed long-term efficacy for up to two years in the treatment of sacroiliac joint pain. PMID:23869175

Determining cardiac vagal threshold from short term heart rate complexity

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Hamdan Rami Abou

2016-09-01

Full Text Available Evaluating individual aerobic exercise capacity is fundamental in sports and exercise medicine but associated with organizational and instrumental effort. Here, we extract an index related to common performance markers, the aerobic and anaerobic thresholds enabling the estimation of exercise capacity from a conventional sports watch supporting beatwise heart rate tracking. Therefore, cardiac vagal threshold (CVT was determined in 19 male subjects performing an incremental maximum exercise test. CVT varied around the anaerobic threshold AnT with mean deviation of 7.9 ± 17.7 W. A high correspondence of the two thresholds was indicated by Bland-Altman plots with limits of agreement −27.5 W and 43.4 W. Additionally, CVT was strongly correlated AnT (rp = 0.86, p < 0.001 and reproduced this marker well (rc = 0.81. We conclude, that cardiac vagal threshold derived from compression entropy time course can be useful to assess physical fitness in an uncomplicated way.

Getting to the Heart of Masculinity Stressors: Masculinity Threats Induce Pronounced Vagal Withdrawal During a Speaking Task.

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Kramer, Brandon L; Himmelstein, Mary S; Springer, Kristen W

2017-12-01

Previous work has found that traditional masculinity ideals and behaviors play a crucial role in higher rates of morbidity and mortality for men. Some studies also suggest that threatening men's masculinity can be stressful. Over time, this stress can weigh on men's cardiovascular and metabolic systems, which may contribute to men's higher rates of cardiometabolic health issues. The purpose of this study is to explore how masculinity threats affect men's heart rate and heart rate variability reactivity (i.e., vagal withdrawal) to masculinity feedback on a social speaking task. Two hundred and eighty-five undergraduate males were randomly assigned to one of six conditions during a laboratory-based speech task. They received one of two feedback types (masculinity or control) and one of three feedback levels (low, high, or dropping) in order to assess whether masculinity threats influence heart rate reactivity and vagal withdrawal patterns during the speech task. Men who receive low masculinity feedback during the speech task experienced more pronounced vagal withdrawal relative to those who received the control. Masculinity threats can induce vagal withdrawal that may accumulate over the life course to contribute to men's relatively worse cardiometabolic health.

Is Tadpole Pupil in an Adolescent Girl Caused by Denervation Hypersensitivity?

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Hansen, Jonas Kjeldbjerg; Møller, Hans Ulrik

2017-06-01

Tadpole pupil is a rarely encountered phenomenon caused by episodic, segmental iris dilator muscle spasm of short duration (2-15 minutes), occurring in clusters without a known precipitating factor. It has most commonly been described in women aged 28 to 48 years. A few hypotheses on pathogenesis have been discussed but none has been proved. Here, we present an adolescent girl with bilateral tadpole pupil that appeared during physical exercise. This is the first pediatric case of tadpole pupil, not caused by preceding surgery, to be published. Based on (1) this case in which tadpole pupil developed when the norepinephrine level rose during exercise, (2) the high ratio of patients with tadpole pupil who concurrently have or later develop Horner syndrome, in which denervation hypersensitivity is well described, (3) a previous report of a patient with both tadpole pupil and Horner syndrome who had denervation hypersensitivity on pharmacological testing, (4) a 29-year-old man with unilateral tadpole pupil induced by exercise, and (5) a 19-year-old man with bilateral tadpole pupil and possible autonomic neuropathy, we suggest denervation hypersensitivity as a probable pathogenic mechanism causing tadpole pupil. In addition, a suggestion for investigations to be performed in future pediatric cases is provided. Georg Thieme Verlag KG Stuttgart · New York.

Electromyographic permutation entropy quantifies diaphragmatic denervation and reinnervation.

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Christopher Kramer

Full Text Available Spontaneous reinnervation after diaphragmatic paralysis due to trauma, surgery, tumors and spinal cord injuries is frequently observed. A possible explanation could be collateral reinnervation, since the diaphragm is commonly double-innervated by the (accessory phrenic nerve. Permutation entropy (PeEn, a complexity measure for time series, may reflect a functional state of neuromuscular transmission by quantifying the complexity of interactions across neural and muscular networks. In an established rat model, electromyographic signals of the diaphragm after phrenicotomy were analyzed using PeEn quantifying denervation and reinnervation. Thirty-three anesthetized rats were unilaterally phrenicotomized. After 1, 3, 9, 27 and 81 days, diaphragmatic electromyographic PeEn was analyzed in vivo from sternal, mid-costal and crural areas of both hemidiaphragms. After euthanasia of the animals, both hemidiaphragms were dissected for fiber type evaluation. The electromyographic incidence of an accessory phrenic nerve was 76%. At day 1 after phrenicotomy, PeEn (normalized values was significantly diminished in the sternal (median: 0.69; interquartile range: 0.66-0.75 and mid-costal area (0.68; 0.66-0.72 compared to the non-denervated side (0.84; 0.78-0.90 at threshold p<0.05. In the crural area, innervated by the accessory phrenic nerve, PeEn remained unchanged (0.79; 0.72-0.86. During reinnervation over 81 days, PeEn normalized in the mid-costal area (0.84; 0.77-0.86, whereas it remained reduced in the sternal area (0.77; 0.70-0.81. Fiber type grouping, a histological sign for reinnervation, was found in the mid-costal area in 20% after 27 days and in 80% after 81 days. Collateral reinnervation can restore diaphragm activity after phrenicotomy. Electromyographic PeEn represents a new, distinctive assessment characterizing intramuscular function following denervation and reinnervation.

Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis?

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Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J

2013-12-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.

Endovascular Renal Artery Denervation: Why, When, and How?

International Nuclear Information System (INIS)

Sapoval, Marc; Azizi, Michel; Bobrie, Guillaume; Cholley, Bernard; Pagny, Jean-Yves; Plouin, Pierre-François

2012-01-01

Endovascular renal artery denervation (ERAD) is a new procedure to reduce renal and systemic sympathetic overactivity in hypertensive patients. The role of sympathetic overactivity is recognized since a long time as being one the contributor of human hypertension. In support of this view, several studies in experimental models of hypertension in animal as well as hypertensive human subjects have demonstrated that sympathetic overactivity plays a central role in hypertension catheter based renal denervation is now possible, and this procedure may provide a useful adjunct for the management of patients with drug-resistant primary hypertension. Following a cohort study, the results of an open label randomized control trial have been published showing very encouraging results. The purpose of this paper is to help interventionalists to better understand the medical and technical issues related to this new intervention. It is most likely that as underlined in a recent editorial several other technical approaches may appear in the future, however because this is the only technique that is available today, we will focus on radiofrequency based technique.

Altered Satellite Cell Responsiveness and Denervation Implicated in Progression of Rotator-Cuff Injury.

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Deanna Gigliotti

Full Text Available Rotator-cuff injury (RCI is common and painful; even after surgery, joint stability and function may not recover. Relative contributions to atrophy from disuse, fibrosis, denervation, and satellite-cell responsiveness to activating stimuli are not known.Potential contributions of denervation and disrupted satellite cell responses to growth signals were examined in supraspinatus (SS and control (ipsilateral deltoid muscles biopsied from participants with RCI (N = 27. Biopsies were prepared for explant culture (to study satellite cell activity, immunostained to localize Pax7, BrdU, and Semaphorin 3A in satellite cells, sectioning to study blood vessel density, and western blotting to measure the fetal (γ subunit of acetylcholine receptor (γ-AchR. Principal component analysis (PCA for 35 parameters extracted components identified variables that contributed most to variability in the dataset. γ-AchR was higher in SS than control, indicating denervation. Satellite cells in SS had a low baseline level of activity (Pax7+ cells labelled in S-phase versus control; only satellite cells in SS showed increased proliferative activity after nitric oxide-donor treatment. Interestingly, satellite cell localization of Semaphorin 3A, a neuro-chemorepellent, was greater in SS (consistent with fiber denervation than control muscle at baseline. PCAs extracted components including fiber atrophy, satellite cell activity, fibrosis, atrogin-1, smoking status, vascular density, γAchR, and the time between symptoms and surgery. Use of deltoid as a control for SS was supported by PCA findings since "muscle" was not extracted as a variable in the first two principal components. SS muscle in RCI is therefore atrophic, denervated, and fibrotic, and has satellite cells that respond to activating stimuli.Since SS satellite cells can be activated in culture, a NO-donor drug combined with stretching could promote muscle growth and improve functional outcome after RCI. PCAs

Altered Satellite Cell Responsiveness and Denervation Implicated in Progression of Rotator-Cuff Injury.

Science.gov (United States)

Gigliotti, Deanna; Leiter, Jeff R S; MacDonald, Peter B; Peeler, Jason; Anderson, Judy E

Rotator-cuff injury (RCI) is common and painful; even after surgery, joint stability and function may not recover. Relative contributions to atrophy from disuse, fibrosis, denervation, and satellite-cell responsiveness to activating stimuli are not known. Potential contributions of denervation and disrupted satellite cell responses to growth signals were examined in supraspinatus (SS) and control (ipsilateral deltoid) muscles biopsied from participants with RCI (N = 27). Biopsies were prepared for explant culture (to study satellite cell activity), immunostained to localize Pax7, BrdU, and Semaphorin 3A in satellite cells, sectioning to study blood vessel density, and western blotting to measure the fetal (γ) subunit of acetylcholine receptor (γ-AchR). Principal component analysis (PCA) for 35 parameters extracted components identified variables that contributed most to variability in the dataset. γ-AchR was higher in SS than control, indicating denervation. Satellite cells in SS had a low baseline level of activity (Pax7+ cells labelled in S-phase) versus control; only satellite cells in SS showed increased proliferative activity after nitric oxide-donor treatment. Interestingly, satellite cell localization of Semaphorin 3A, a neuro-chemorepellent, was greater in SS (consistent with fiber denervation) than control muscle at baseline. PCAs extracted components including fiber atrophy, satellite cell activity, fibrosis, atrogin-1, smoking status, vascular density, γAchR, and the time between symptoms and surgery. Use of deltoid as a control for SS was supported by PCA findings since "muscle" was not extracted as a variable in the first two principal components. SS muscle in RCI is therefore atrophic, denervated, and fibrotic, and has satellite cells that respond to activating stimuli. Since SS satellite cells can be activated in culture, a NO-donor drug combined with stretching could promote muscle growth and improve functional outcome after RCI. PCAs suggest

Denervation atrophy is independent from Akt and mTOR activation and is not rescued by myostatin inhibition

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Elizabeth M. MacDonald

2014-04-01

Full Text Available The purpose of our study was to compare two acquired muscle atrophies and the use of myostatin inhibition for their treatment. Myostatin naturally inhibits skeletal muscle growth by binding to ActRIIB, a receptor on the cell surface of myofibers. Because blocking myostatin in an adult wild-type mouse induces profound muscle hypertrophy, we applied a soluble ActRIIB receptor to models of disuse (limb immobilization and denervation (sciatic nerve resection atrophy. We found that treatment of immobilized mice with ActRIIB prevented the loss of muscle mass observed in placebo-treated mice. Our results suggest that this protection from disuse atrophy is regulated by serum and glucocorticoid-induced kinase (SGK rather than by Akt. Denervation atrophy, however, was not protected by ActRIIB treatment, yet resulted in an upregulation of the pro-growth factors Akt, SGK and components of the mTOR pathway. We then treated the denervated mice with the mTOR inhibitor rapamycin and found that, despite a reduction in mTOR activation, there is no alteration of the atrophy phenotype. Additionally, rapamycin prevented the denervation-induced upregulation of the mTORC2 substrates Akt and SGK. Thus, our studies show that denervation atrophy is not only independent from Akt, SGK and mTOR activation but also has a different underlying pathophysiological mechanism than disuse atrophy.

Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity.

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Sen, Tanusree; Cawthon, Carolina R; Ihde, Benjamin Thomas; Hajnal, Andras; DiLorenzo, Patricia M; de La Serre, Claire B; Czaja, Krzysztof

2017-05-01

Obesity is one of the major health issues in the United States. Consumption of diets rich in energy, notably from fats and sugars (high-fat/high-sugar diet: HF/HSD) is linked to the development of obesity and a popular dietary approach for weight loss is to reduce fat intake. Obesity research traditionally uses low and high fat diets and there has been limited investigation of the potential detrimental effects of a low-fat/high-sugar diet (LF/HSD) on body fat accumulation and health. Therefore, in the present study, we investigated the effects of HF/HSD and LF/HSD on microbiota composition, gut inflammation, gut-brain vagal communication and body fat accumulation. Specifically, we tested the hypothesis that LF/HSD changes the gut microbiota, induces gut inflammation and alters vagal gut-brain communication, associated with increased body fat accumulation. Sprague-Dawley rats were fed an HF/HSD, LF/HSD or control low-fat/low-sugar diet (LF/LSD) for 4weeks. Body weight, caloric intake, and body composition were monitored daily and fecal samples were collected at baseline, 1, 6 and 27days after the dietary switch. After four weeks, blood and tissues (gut, brain, liver and nodose ganglia) were sampled. Both HF/HSD and LF/HSD-fed rats displayed significant increases in body weight and body fat compared to LF/LSD-fed rats. 16S rRNA sequencing showed that both HF/HSD and LF/HSD-fed animals exhibited gut microbiota dysbiosis characterized by an overall decrease in bacterial diversity and an increase in Firmicutes/Bacteriodetes ratio. Dysbiosis was typified by a bloom in Clostridia and Bacilli and a marked decrease in Lactobacillus spp. LF/HSD-fed animals showed a specific increase in Sutterella and Bilophila, both Proteobacteria, abundances of which have been associated with liver damage. Expression of pro-inflammatory cytokines, such as IL-6, IL-1β and TNFα, was upregulated in the cecum while levels of tight junction protein occludin were downregulated in both HF

Pellet ablation and ablation model development

International Nuclear Information System (INIS)

Houlberg, W.A.

1989-01-01

A broad survey of pellet ablation is given, based primarily on information presented at this meeting. The implications of various experimental observations for ablation theory are derived from qualitative arguments of the physics involved. The major elements of a more complete ablation theory are then outlined in terms of these observations. This is followed by a few suggestions on improving the connections between theory and experimental results through examination of ablation data. Although this is a rather aggressive undertaking for such a brief (and undoubtedly incomplete) assessment, some of the discussion may help us advance the understanding of pellet ablation. 17 refs

Vagal and sympathetic activity in burnouts during a mentally demanding workday

NARCIS (Netherlands)

Zanstra, Ydwine J.; Schellekens, Jan M. H.; Schaap, Cas; Kooistra, Libbe

2006-01-01

Objective: We study differences in task performance and related sympathetic-vagal reaction patterns between burnouts and controls during a mentally demanding workday. Method: Thirty-nine adults with burnout and 40 healthy controls performed mental tasks during a simulated workday. At pretest, just

Renal denervation in treatment-resistant essential hypertension. A randomized, SHAM-controlled, double-blinded 24-h blood pressure-based trial.

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Mathiassen, Ole N; Vase, Henrik; Bech, Jesper N; Christensen, Kent L; Buus, Niels H; Schroeder, Anne P; Lederballe, Ole; Rickers, Hans; Kampmann, Ulla; Poulsen, Per L; Hansen, Klavs W; Btker, Hans E; Peters, Christian D; Engholm, Morten; Bertelsen, Jannik B; Lassen, Jens F; Langfeldt, Sten; Andersen, Gratien; Pedersen, Erling B; Kaltoft, Anne

2016-08-01

Renal denervation (RDN), treating resistant hypertension, has, in open trial design, been shown to lower blood pressure (BP) dramatically, but this was primarily with respect to office BP. We conducted a SHAM-controlled, double-blind, randomized, single-center trial to establish efficacy data based on 24-h ambulatory BP measurements (ABPM). Inclusion criteria were daytime systolic ABPM at least 145 mmHg following 1 month of stable medication and 2 weeks of compliance registration. All RDN procedures were carried out by an experienced operator using the unipolar Medtronic Flex catheter (Medtronic, Santa Rosa, California, USA). We randomized 69 patients with treatment-resistant hypertension to RDN (n = 36) or SHAM (n = 33). Groups were well balanced at baseline. Mean baseline daytime systolic ABPM was 159 ± 12 mmHg (RDN) and 159 ± 14 mmHg (SHAM). Groups had similar reductions in daytime systolic ABPM compared with baseline at 3 months [-6.2 ± 18.8 mmHg (RDN) vs. -6.0 ± 13.5 mmHg (SHAM)] and at 6 months [-6.1 ± 18.9 mmHg (RDN) vs. -4.3 ± 15.1 mmHg (SHAM)]. Mean usage of antihypertensive medication (daily defined doses) at 3 months was equal [6.8 ± 2.7 (RDN) vs. 7.0 ± 2.5 (SHAM)].RDN performed at a single center and by a high-volume operator reduced ABPM to the same level as SHAM treatment and thus confirms the result of the HTN3 trial. Further, clinical use of RDN for treatment of resistant hypertension should await positive results from double-blinded, SHAM-controlled trials with multipolar ablation catheters or novel denervation techniques.

Exposure to a high fat diet during the perinatal period alters vagal motoneurone excitability, even in the absence of obesity.

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Bhagat, Ruchi; Fortna, Samuel R; Browning, Kirsteen N

2015-01-01

Obesity is recognized as being multifactorial in origin, involving both genetic and environmental factors. The perinatal period is known to be critically important in the development of neural circuits responsible for energy homeostasis and the integration of autonomic reflexes. Diet-induced obesity alters the biophysical, pharmacological and morphological properties of vagal neurocircuits regulating upper gastrointestinal tract functions, including satiety. Less information is available, however, regarding the effects of a high fat diet (HFD) itself on the properties of vagal neurocircuits. The present study was designed to test the hypothesis that exposure to a HFD during the perinatal period alters the electrophysiological, pharmacological and morphological properties of vagal efferent motoneurones innervating the stomach. Our data indicate that perinatal HFD decreases the excitability of gastric-projecting dorsal motor nucleus neurones and dysregulates neurotransmitter release from synaptic inputs and that these alterations occur prior to the development of obesity. These findings represent the first direct evidence that exposure to a HFD modulates the processing of central vagal neurocircuits even in the absence of obesity. The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin

Permanent LMN denervation of human skeletal muscle and recovery by h-b FES: management and monitoring

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Helmut Kern

2010-09-01

Full Text Available Denervation of a defined skeletal muscle is due to lower motor neuron (LMN or peripheral nerve lesions that have major consequences on the muscle tissue. After early atrophy, the mid- and late-phases presents two very contrasting myofibers populations: beside those severely atrophic with internalized groups of myonuclei, large fast-type muscle fibers continue to be present 4 to 6 years after Spinal Cord Injury (SCI. Recent results of rat experiments provides the rational basis for understanding the residual functional characteristics of the long-term denervated muscle and the molecular explanation of its ability to respond to home-base functional electrical stimulation (h-b FES using custom-designed electrodes and stimulators. Further outcomes of the Vienna-Padova ten-year collaboration are: 1. a world-unique Myo- Bank of muscle biopsies and 2. improved imaging procedures (Color Computer Tomography (CT scan and Functional Echomyography, all demonstrating that h-b FES induces improvements in muscle contractility, tissue composition and mass, despite permanent LMN denervation. The benefits of h-b FES could be extended from patents suffering with complete Conus-Cauda Syndrome to the numerous patients with incomplete LMN denervation of skeletal muscles to determine whether h-b FES reduces secondary complications related to disuse and impaired blood perfusion (reduction in bone density, risk of bone fracture, decubitus ulcers, and pulmonary thromboembolism. We are confident that translation of the results of a clinical experiment, the EU Project RISE, to the larger cohort of incomplete LMN denervated muscles will provide the wanted results.

Short-Term Motor Compensations to Denervation of Feline Soleus and Lateral Gastrocnemius Result in Preservation of Ankle Mechanical Output during Locomotion

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Prilutsky, Boris I.; Maas, Huub; Bulgakova, Margarita; Hodson-Tole, Emma F.; Gregor, Robert J.

2011-01-01

Denervation of selected ankle extensors in animals results in locomotor changes. These changes have been suggested to permit preservation of global kinematic characteristics of the hindlimb during stance. The peak ankle joint moment is also preserved immediately after denervation of several ankle extensors in the cat, suggesting that the animal's response to peripheral nerve injury may also be aimed at preserving ankle mechanical output. We tested this hypothesis by comparing joint moments and power patterns during walking before and after denervation of soleus and lateral gastrocnemius muscles. Hindlimb kinematics, ground reaction forces and electromyographic activity of selected muscles were recorded during level, downslope (−50%) and upslope (50%) walking before and 1–3 weeks after nerve denervation. Denervation resulted in increased activity of the intact medial gastrocnemius and plantaris muscles, greater ankle dorsiflexion, smaller knee flexion, and the preservation of the peak ankle moment during stance. Surprisingly, ankle positive power generated in the propulsion phase of stance was increased (up to 50%) after denervation in all walking conditions (p ankle. The additional mechanical energy generated at the ankle during propulsion can result, in part, from increased activity of intact synergists, the use of passive tissues around the ankle and by the tendon action of ankle two-joint muscles and crural fascia. PMID:21411965

IN VITRO EXAMINATION OF ONTOGENESIS OF DEVELOPING NEURONAL CELLS IN VAGAL NUCLEI IN MEDULLA OBLONGATA IN NEWBORNS

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Islami, Hilmi; Shabani, Ragip; Bexheti, Sadi; Behluli, Ibrahim; Šukalo, Aziz; Raka, Denis; Koliqi, Rozafa; Haliti, Naim; Dauti, Hilmi; Krasniqi, Shaip; Disha, Mentor

2008-01-01

The development of neuron cells in vagal nerve nuclei in medulla oblongata was studied in vitro in live newborns and stillborns from different cases. Morphological changes were studied in respiratory nuclei of dorsal motor centre (DMNV) and nucleus tractus solitarius (NTS) in medulla oblongata. The material from medulla oblongata was fixated in 10μ buffered formalin solution. Fixated material was cut in series of 10μ thickness, with starting point from obex in ± 4 mm thickness. Special histochemical and histoenzymatic methods for central nervous system were used: cresyl echt violet coloring, tolyidin blue, Sevier-Munger modification and Grimelius coloring. In immature newborns (abortions and immature) in dorsal motor nucleus of the vagus (DMNV) population stages S1, S2, S3 are dominant. In neuron population in vagal sensory nuclei (NTS) stages S1, S2 are dominant. In more advanced stages of development of newborns (premature), in DMNV stages S3 and S4 are seen and in NTS stages S2 and S3 are dominant. In mature phase of newborns (maturity) in vagal nucleus DMNV stages S5 and S6 are dominant, while in sensory nucleus NTS stages S4 and S5 are dominant. These data suggest that neuron population in dorsal motor nucleus of the vagus (DMNV) are more advanced in neuronal maturity in comparison with sensory neuron population of vagal sensory nucleus NTS. This occurrence shows that phylogenetic development of motor complex is more advanced than the sensory one, which is expected to take new information’s from the extra uterine life after birth (extra uterine vagal phenotype) PMID:19125713

Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure.

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Ichige, Marcelo H A; Santos, Carla R; Jordão, Camila P; Ceroni, Alexandre; Negrão, Carlos E; Michelini, Lisete C

2016-11-01

Heart Failure (HF) is accompanied by reduced ventricular function, activation of compensatory neurohormonal mechanisms and marked autonomic dysfunction characterized by exaggerated sympathoexcitation and reduced parasympathetic activity. With 6 weeks of exercise training, HF-related loss of choline acetyltransferase (ChAT)-positive vagal preganglionic neurones is avoided, restoring the parasympathetic tonus to the heart, and the immunoreactivity of dopamine β-hydroxylase-positive premotor neurones that drive sympathetic outflow to the heart is reduced. Training-induced correction of autonomic dysfunction occurs even with the persistence of abnormal ventricular function. Strong positive correlation between improved parasympathetic tonus to the heart and increased ChAT immunoreactivity in vagal preganglionic neurones after training indicates this is a crucial mechanism to restore autonomic function in heart failure. Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6 weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine β-hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative

Differential alterations in gene expression profiles contribute to time-dependent effects of nandrolone to prevent denervation atrophy

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Bauman William A

2010-10-01

Full Text Available Abstract Background Anabolic steroids, such as nandrolone, slow muscle atrophy, but the mechanisms responsible for this effect are largely unknown. Their effects on muscle size and gene expression depend upon time, and the cause of muscle atrophy. Administration of nandrolone for 7 days beginning either concomitantly with sciatic nerve transection (7 days or 29 days later (35 days attenuated denervation atrophy at 35 but not 7 days. We reasoned that this model could be used to identify genes that are regulated by nandrolone and slow denervation atrophy, as well as genes that might explain the time-dependence of nandrolone effects on such atrophy. Affymetrix microarrays were used to profile gene expression changes due to nandrolone at 7 and 35 days and to identify major gene expression changes in denervated muscle between 7 and 35 days. Results Nandrolone selectively altered expression of 124 genes at 7 days and 122 genes at 35 days, with only 20 genes being regulated at both time points. Marked differences in biological function of genes regulated by nandrolone at 7 and 35 days were observed. At 35, but not 7 days, nandrolone reduced mRNA and protein levels for FOXO1, the mTOR inhibitor REDD2, and the calcineurin inhibitor RCAN2 and increased those for ApoD. At 35 days, correlations between mRNA levels and the size of denervated muscle were negative for RCAN2, and positive for ApoD. Nandrolone also regulated genes for Wnt signaling molecules. Comparison of gene expression at 7 and 35 days after denervation revealed marked alterations in the expression of 9 transcriptional coregulators, including Ankrd1 and 2, and many transcription factors and kinases. Conclusions Genes regulated in denervated muscle after 7 days administration of nandrolone are almost entirely different at 7 versus 35 days. Alterations in levels of FOXO1, and of genes involved in signaling through calcineurin, mTOR and Wnt may be linked to the favorable action of nandrolone on

Clonidine, an α2 receptor agonist, diminishes GABAergic neurotransmission to cardiac vagal neurons in the nucleus ambiguus

OpenAIRE

Philbin, Kerry E.; Bateman, Ryan J.; Mendelowitz, David

2010-01-01

In hypertension there is an autonomic imbalance in which sympathetic activity dominates over parasympathetic control. Parasympathetic activity to the heart originates from cardiac vagal neurons located in the nucleus ambiguus. Pre-sympathetic neurons that project to sympathetic neurons in the spinal cord are located in the ventral brainstem in close proximity to cardiac vagal neurons, and many of these pre-sympathetic neurons are catecholaminergic. In addition to their projection to the spina...

Medical Devices; Neurological Devices; Classification of the External Vagal Nerve Stimulator for Headache. Final order.

Science.gov (United States)

2017-12-27

The Food and Drug Administration (FDA or we) is classifying the external vagal nerve stimulator for headache into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the external vagal nerve stimulator for headache's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

Food-intake dysregulation in type 2 diabetic Goto-Kakizaki rats: hypothesized role of dysfunctional brainstem thyrotropin-releasing hormone and impaired vagal output.

Science.gov (United States)

Zhao, K; Ao, Y; Harper, R M; Go, V L W; Yang, H

2013-09-05

Thyrotropin-releasing hormone (TRH), a neuropeptide contained in neural terminals innervating brainstem vagal motor neurons, enhances vagal outflow to modify multisystemic visceral functions and food intake. Type 2 diabetes (T2D) and obesity are accompanied by impaired vagal functioning. We examined the possibility that impaired brainstem TRH action may contribute to the vagal dysregulation of food intake in Goto-Kakizaki (GK) rats, a T2D model with hyperglycemia and impaired central vagal activation by TRH. Food intake induced by intracisternal injection of TRH analog was reduced significantly by 50% in GK rats, compared to Wistar rats. Similarly, natural food intake in the dark phase or food intake after an overnight fast was reduced by 56-81% in GK rats. Fasting (48h) and refeeding (2h)-associated changes in serum ghrelin, insulin, peptide YY, pancreatic polypeptide and leptin, and the concomitant changes in orexigenic or anorexigenic peptide expression in the brainstem and hypothalamus, all apparent in Wistar rats, were absent or markedly reduced in GK rats, with hormone release stimulated by vagal activation, such as ghrelin and pancreatic polypeptide, decreased substantially. Fasting-induced Fos expression accompanying endogenous brainstem TRH action decreased by 66% and 91%, respectively, in the nucleus tractus solitarius (NTS) and the dorsal motor nucleus of the vagus (DMV) in GK rats, compared to Wistar rats. Refeeding abolished fasting-induced Fos-expression in the NTS, while that in the DMV remained in Wistar but not GK rats. These findings indicate that dysfunctional brainstem TRH-elicited vagal impairment contributes to the disturbed food intake in T2D GK rats, and may provide a pathophysiological mechanism which prevents further weight gain in T2D and obesity. Published by Elsevier Ltd.

Does dysfunction of the autonomic nervous system affect success of renal denervation in reducing blood pressure?

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Fricke, Lisa; Petroff, David; Desch, Steffen; Lurz, Philipp; Reinhardt, Sebastian; Sonnabend, Melanie; Classen, Joseph; Baum, Petra

2017-01-01

Renal denervation is an interventional approach aiming to reduce high blood pressure. Its efficacy is subject of controversial debate. We analyzed autonomic function in patients undergoing renal denervation to identify responders. A total of 21 patients with treatment-resistant hypertension scheduled for renal denervation were included. Heart rate variability, pupillary function and sympathetic skin response were examined prior to intervention. Before and 1 or 3 months after intervention, 24-h ambulatory blood pressure readings were taken. Patients were stratified according to sympathetic nervous system function. Sympathetic activity was reduced in 12 participants (group 1) and normal or enhanced in nine patients (group 2). The mean of daytime systolic blood pressure decreased in groups 1 and 2 from 168 to 157 mmHg (95% confidence interval for difference, 1-21 mmHg, p = 0.035) and from 166 to 145 mmHg (8-34 mmHg, p = 0.005), respectively. In a linear model, blood pressure reduction was 11.3 mmHg (0.3-22 mmHg) greater in group 2 than in group 1 (p = 0.045). Patients with preexisting reduced activity of the sympathetic nervous system benefited less from renal denervation.

Does dysfunction of the autonomic nervous system affect success of renal denervation in reducing blood pressure?

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Lisa Fricke

2017-04-01

Full Text Available Objectives: Renal denervation is an interventional approach aiming to reduce high blood pressure. Its efficacy is subject of controversial debate. We analyzed autonomic function in patients undergoing renal denervation to identify responders. Methods: A total of 21 patients with treatment-resistant hypertension scheduled for renal denervation were included. Heart rate variability, pupillary function and sympathetic skin response were examined prior to intervention. Before and 1 or 3 months after intervention, 24-h ambulatory blood pressure readings were taken. Results: Patients were stratified according to sympathetic nervous system function. Sympathetic activity was reduced in 12 participants (group 1 and normal or enhanced in nine patients (group 2. The mean of daytime systolic blood pressure decreased in groups 1 and 2 from 168 to 157 mmHg (95% confidence interval for difference, 1–21 mmHg, p = 0.035 and from 166 to 145 mmHg (8–34 mmHg, p = 0.005, respectively. In a linear model, blood pressure reduction was 11.3 mmHg (0.3–22 mmHg greater in group 2 than in group 1 (p = 0.045. Conclusion: Patients with preexisting reduced activity of the sympathetic nervous system benefited less from renal denervation.

Sympathetic Response and Outcomes Following Renal Denervation in Patients With Chronic Heart Failure: 12-Month Outcomes From the Symplicity HF Feasibility Study.

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Hopper, Ingrid; Gronda, Edoardo; Hoppe, Uta C; Rundqvist, Bengt; Marwick, Thomas H; Shetty, Sharad; Hayward, Christopher; Lambert, Thomas; Hering, Dagmara; Esler, Murray; Schlaich, Markus; Walton, Antony; Airoldi, Flavio; Brandt, Mathias C; Cohen, Sidney A; Reiters, Pascalle; Krum, Henry

2017-09-01

Heart failure (HF) is associated with chronic sympathetic activation. Renal denervation (RDN) aims to reduce sympathetic activity by ablating the renal sympathetic nerves. We investigated the effect of RDN in patients with chronic HF and concurrent renal dysfunction in a prospective, multicenter, single-arm feasibility study. Thirty-nine patients with chronic systolic HF (left ventricular ejection fraction [LVEF] renal impairment (estimated glomerular filtration rate [eGFR; assessed with the use of the Modification of Diet in Renal Disease equation] renal artery occlusion that was possibly related to the denervation procedure. Statistically significant reductions in N-terminal pro-B-type natriuretic peptide (NT-proBNP; 1530 ± 1228 vs 1428 ± 1844 ng/mL; P = .006) and 120-minute glucose tolerance test (11.2 ± 5.1 vs 9.9 ± 3.6; P = .026) were seen at 12 months, but there was no significant change in LVEF (28 ± 9% vs 29 ± 11%; P= .536), 6-minute walk test (384 ± 96 vs 391 ± 97 m; P= .584), or eGFR (52.6 ± 15.3 vs 52.3 ± 18.5 mL • min -1  • 1.73 m -2 ; P= .700). RDN was associated with reductions in NT-proBNP and 120-minute glucose tolerance test in HF patients 12 months after RDN treatment. There was no deterioration in other indices of cardiac and renal function in this small feasibility study. Copyright © 2017 Elsevier Inc. All rights reserved.

Renal denervation for the management of resistant hypertension

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Patel HC

2015-12-01

Full Text Available Hitesh C Patel,1 Carl Hayward,1 Vassilis Vassiliou,1 Ketna Patel,2 James P Howard,3 Carlo Di Mario11NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK; 2Department of Cardiology, Royal Free Hospital, London, UK; 3National Heart and Lung Institute, Imperial College, London, UKAbstract: Renal sympathetic denervation (RSD as a therapy for patients with resistant hypertension has attracted great interest. The majority of studies in this field have demonstrated impressive reductions in blood pressure (BP. However, these trials were not randomized or sham-controlled and hence, the findings may have been overinflated due to trial biases. SYMPLICITY HTN-3 was the first randomized controlled trial to use a blinded sham-control and ambulatory BP monitoring. A surprise to many was that this study was neutral. Possible reasons for this neutrality include the fact that RSD may not be effective at lowering BP in man, RSD was not performed adequately due to limited operator experience, patients’ adherence with their antihypertensive drugs may have changed during the trial period, and perhaps the intervention only works in certain subgroups that are yet to be identified. Future studies seeking to demonstrate efficacy of RSD should be designed as randomized blinded sham-controlled trials. The efficacy of RSD is in doubt, but many feel that its safety has been established through the thousands of patients in whom the procedure has been performed. Over 90% of these data, however, are for the Symplicity™ system and rarely extend beyond 12 months of follow-up. Long-term safety cannot be assumed with RSD and nor should it be assumed that if one catheter system is safe then all are. We hope that in the near future, with the benefit of well-designed clinical trials, the role of renal denervation in the management of hypertension will be established.Keywords: resistant hypertension, renal denervation, sympathetic nervous system

Non-invasive Renal Denervation: Update on External Ultrasound Approaches.

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Schmieder, Roland E; Ott, Christian; Bramlage, Peter

2016-06-01

In the last decade, intravenous renal denervation (RDN) has emerged as an alternative to pharmacological treatment in patients with resistant hypertension, but currently involves an invasive and technically challenging procedure. The Surround Sound™ system utilises externally delivered ultrasound to achieve RDN using a completely non-invasive, automated real-time tracking system coupled with a therapeutic delivery module thereby addressing these limitations. A brief history, technical overview and summary of preclinical and clinical studies of the KonaMedical Surround Sound™ system are presented. A literature search using the terms "renal denervation", "resistant hypertension" and "external ultrasound" was performed using PubMed, and references retrieved were selected based on relevancy and year of publication (date range 1991-2015). The Surround Sound™ system appears to be a promising approach to RDN which eliminates several of the factors currently limiting the intravenous approach. So far, it has demonstrated efficacy for reducing blood pressure in resistant hypertension patients with minimal adverse effects. Several double-blind, sham-controlled clinical trials are currently underway to confirm the validity of these findings.

Antifibrillatory effects of renal denervation on ventricular fibrillation in a canine model of pacing-induced heart failure.

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Luo, Qingzhi; Jin, Qi; Zhang, Ning; Huang, Shangwei; Han, Yanxin; Lin, Changjian; Ling, Tianyou; Chen, Kang; Pan, Wenqi; Wu, Liqun

2018-01-01

What is the central question of this study? In the present study, we investigated the effects of renal denervation on the vulnerability to ventricular fibrillation and the ventricular electrical properties in a rapid pacing-induced heart failure canine model. What is the main finding and its importance? Renal denervation significantly attenuated the process of heart failure and improved left ventricular systolic dysfunction, stabilized ventricular electrophysiological properties and decreased the vulnerability of the heart to ventricular fibrillation during heart failure. Thus, renal denervation can attenuate ventricular electrical remodelling and exert a potential antifibrillatory action in a pacing-induced heart failure canine model. In this study, we investigated the effects of renal denervation (RDN) on the vulnerability to ventricular fibrillation (VF) and the ventricular electrical properties in a canine model of pacing-induced heart failure (HF). Eighteen beagles were divided into the following three groups: control (n = 6), HF (n = 6) and HF+RDN (n = 6). Heart failure was induced by rapid right ventricular pacing. Renal denervation was performed simultaneously with the pacemaker implantation in the HF+RDN group. A 64-unipolar basket catheter was used to perform global endocardial mapping of the left ventricle. The restitution properties and dispersion of refractoriness were estimated from the activation recovery intervals (ARIs) by a pacing protocol. The VF threshold (VFT) was defined as the maximal pacing cycle length required to induce VF using a specific pacing protocol. The defibrillation threshold (DFT) was measured by an up-down algorithm. Renal denervation partly restored left ventricular systolic function and attenuated the process of HF. Compared with the control group, the VFT in the HF group was decreased by 27% (106 ± 8.0 versus 135 ± 10 ms, P Renal denervation significantly flattened the ventricular ARI restitution curve by 15% (1

Improvement of Myocardial Function Following Catheter-Based Renal Denervation in Heart Failure

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Song-Yan Liao, MD

2017-06-01

Full Text Available Summary: Renal denervation (RD is a potential novel nonpharmacological therapy for heart failure (HF. We performed bilateral catheter-based RD in 10 adult pigs and compared them with 10 control subjects after induction of HF to investigate the long-term beneficial effects of RD on left ventricular (LV function and regional norepinephrine gradient after conventional HF pharmacological therapy. Compared with control subjects, animals treated with RD demonstrated an improvement in LV function and reduction of norepinephrine gradients over the myocardium and kidney at 10-week follow-up. Our results demonstrated that effective bilateral RD decrease regional norepinephrine gradients and improve LV contractile function compared with medical therapy alone. Key Words: heart failure, left ventricular function, norepinephrine, renal denervation

The anxiolytic effect of Bifidobacterium longum NCC3001 involves vagal pathways for gut-brain communication.

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Bercik, P; Park, A J; Sinclair, D; Khoshdel, A; Lu, J; Huang, X; Deng, Y; Blennerhassett, P A; Fahnestock, M; Moine, D; Berger, B; Huizinga, J D; Kunze, W; McLean, P G; Bergonzelli, G E; Collins, S M; Verdu, E F

2011-12-01

The probiotic Bifidobacterium longum NCC3001 normalizes anxiety-like behavior and hippocampal brain derived neurotrophic factor (BDNF) in mice with infectious colitis. Using a model of chemical colitis we test whether the anxiolytic effect of B. longum involves vagal integrity, and changes in neural cell function. Methods  Mice received dextran sodium sulfate (DSS, 3%) in drinking water during three 1-week cycles. Bifidobacterium longum or placebo were gavaged daily during the last cycle. Some mice underwent subdiaphragmatic vagotomy. Behavior was assessed by step-down test, inflammation by myeloperoxidase (MPO) activity and histology. BDNF mRNA was measured in neuroblastoma SH-SY5Y cells after incubation with sera from B. longum- or placebo-treated mice. The effect of B. longum on myenteric neuron excitability was measured using intracellular microelectrodes. Chronic colitis was associated with anxiety-like behavior, which was absent in previously vagotomized mice. B. longum normalized behavior but had no effect on MPO activity or histological scores. Its anxiolytic effect was absent in mice with established anxiety that were vagotomized before the third DSS cycle. B. longum metabolites did not affect BDNF mRNA expression in SH-SY5Y cells but decreased excitability of enteric neurons. In this colitis model, anxiety-like behavior is vagally mediated. The anxiolytic effect of B. longum requires vagal integrity but does not involve gut immuno-modulation or production of BDNF by neuronal cells. As B. longum decreases excitability of enteric neurons, it may signal to the central nervous system by activating vagal pathways at the level of the enteric nervous system. © 2011 Blackwell Publishing Ltd.

Cardiac vagal regulation in infancy predicts executive function and social competence in preschool: Indirect effects through language.

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Whedon, Margaret; Perry, Nicole B; Calkins, Susan D; Bell, Martha A

2018-05-21

Parasympathetic nervous system functioning in infancy may serve a foundational role in the development of cognitive and socioemotional skills (Calkins, 2007). In this study (N = 297), we investigated the potential indirect effects of cardiac vagal regulation in infancy on children's executive functioning and social competence in preschool via expressive and receptive language in toddlerhood. Vagal regulation was assessed at 10 months during two attention conditions (social, nonsocial) via task-related changes in respiratory sinus arrhythmia (RSA). A path analysis revealed that decreased RSA from baseline in the nonsocial condition and increased RSA in the social condition were related to larger vocabularies in toddlerhood. Additionally, children's vocabulary sizes were positively related to their executive function and social competence in preschool. Indirect effects from vagal regulation in both contexts to both 4-year outcomes were significant, suggesting that early advances in language may represent a mechanism through which biological functioning in infancy impacts social and cognitive functioning in childhood. © 2018 Wiley Periodicals, Inc.

Integrative Blood Pressure Response to Upright Tilt Post Renal Denervation

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Howden, Erin J.; East, Cara; Lawley, Justin S.; Stickford, Abigail S.L.; Verhees, Myrthe; Fu, Qi

2017-01-01

Abstract BACKGROUND Whether renal denervation (RDN) in patients with resistant hypertension normalizes blood pressure (BP) regulation in response to routine cardiovascular stimuli such as upright posture is unknown. We conducted an integrative study of BP regulation in patients with resistant hypertension who had received RDN to characterize autonomic circulatory control. METHODS Twelve patients (60 ± 9 [SD] years, n = 10 males) who participated in the Symplicity HTN-3 trial were studied and compared to 2 age-matched normotensive (Norm) and hypertensive (unmedicated, HTN) control groups. BP, heart rate (HR), cardiac output (Qc), muscle sympathetic nerve activity (MSNA), and neurohormonal variables were measured supine, and 30° (5 minutes) and 60° (20 minutes) head-up-tilt (HUT). Total peripheral resistance (TPR) was calculated from mean arterial pressure and Qc. RESULTS Despite treatment with RDN and 4.8 (range, 3–7) antihypertensive medications, the RDN had significantly higher supine systolic BP compared to Norm and HTN (149 ± 15 vs. 118 ± 6, 108 ± 8 mm Hg, P < 0.001). When supine, RDN had higher HR, TPR, MSNA, plasma norepinephrine, and effective arterial elastance compared to Norm. Plasma norepinephrine, Qc, and HR were also higher in the RDN vs. HTN. During HUT, BP remained higher in the RDN, due to increases in Qc, plasma norepinephrine, and aldosterone. CONCLUSION We provide evidence of a possible mechanism by which BP remains elevated post RDN, with the observation of increased Qc and arterial stiffness, as well as plasma norepinephrine and aldosterone levels at approximately 2 years post treatment. These findings may be the consequence of incomplete ablation of sympathetic renal nerves or be related to other factors. PMID:28338768

Renal sympathetic denervation for treatment of patients with heart failure: summary of the available evidence.

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Nammas, Wail; Koistinen, Juhani; Paana, Tuomas; Karjalainen, Pasi P

2017-08-01

Heart failure syndrome results from compensatory mechanisms that operate to restore - back to normal - the systemic perfusion pressure. Sympathetic overactivity plays a pivotal role in heart failure; norepinephrine contributes to maintenance of the systemic blood pressure and increasing preload. Cardiac norepinephrine spillover increases in patients with heart failure; norepinephrine exerts direct toxicity on cardiac myocytes resulting in a decrease of synthetic activity and/or viability. Importantly, cardiac norepinephrine spillover is a powerful predictor of mortality in patients with moderate to severe HF. This provided the rationale for trials that demonstrated survival benefit associated with the use of beta adrenergic blockers in heart failure with reduced ejection fraction. Nevertheless, the MOXCON trial demonstrated that rapid uptitration of moxonidine (inhibitor of central sympathetic outflow) in patients with heart failure was associated with excess mortality and morbidity, despite reduction of plasma norepinephrine. Interestingly, renal norepinephrine spillover was the only independent predictor of adverse outcome in patients with heart failure, in multivariable analysis. Recently, renal sympathetic denervation has emerged as a novel approach for control of blood pressure in patients with treatment-resistant hypertension. This article summarizes the available evidence for the effect of renal sympathetic denervation in the setting of heart failure. Key messages Experimental studies supported a beneficial effect of renal sympathetic denervation in heart failure with reduced ejection fraction. Clinical studies demonstrated improvement of symptoms, and left ventricular function. In heart failure and preserved ejection fraction, renal sympathetic denervation is associated with improvement of surrogate endpoints.

The effects of denervation, reinnervation, and muscle imbalance on functional muscle length and elbow flexion contracture following neonatal brachial plexus injury.

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Weekley, Holly; Nikolaou, Sia; Hu, Liangjun; Eismann, Emily; Wylie, Christopher; Cornwall, Roger

2012-08-01

The pathophysiology of paradoxical elbow flexion contractures following neonatal brachial plexus injury (NBPI) is incompletely understood. The current study tests the hypothesis that this contracture occurs by denervation-induced impairment of elbow flexor muscle growth. Unilateral forelimb paralysis was created in mice in four neonatal (5-day-old) BPI groups (C5-6 excision, C5-6 neurotomy, C5-6 neurotomy/repair, and C5-T1 global excision), one non-neonatal BPI group (28-day-old C5-6 excision), and two neonatal muscle imbalance groups (triceps tenotomy ± C5-6 excision). Four weeks post-operatively, motor function, elbow range of motion, and biceps/brachialis functional lengths were assessed. Musculocutaneous nerve (MCN) denervation and reinnervation were assessed immunohistochemically. Elbow flexion motor recovery and elbow flexion contractures varied inversely among the neonatal BPI groups. Contracture severity correlated with biceps/brachialis shortening and MCN denervation (relative axon loss), with no contractures occurring in mice with MCN reinnervation (presence of growth cones). No contractures or biceps/brachialis shortening occurred following non-neonatal BPI, regardless of denervation or reinnervation. Neonatal triceps tenotomy did not cause contractures or biceps/brachialis shortening, nor did it worsen those following neonatal C5-6 excision. Denervation-induced functional shortening of elbow flexor muscles leads to variable elbow flexion contractures depending on the degree, permanence, and timing of denervation, independent of muscle imbalance. Copyright © 2012 Orthopaedic Research Society.

Cardiac troponin T and fast skeletal muscle denervation in ageing.

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Xu, Zherong; Feng, Xin; Dong, Juan; Wang, Zhong-Min; Lee, Jingyun; Furdui, Cristina; Files, Daniel Clark; Beavers, Kristen M; Kritchevsky, Stephen; Milligan, Carolanne; Jin, Jian-Ping; Delbono, Osvaldo; Zhang, Tan

2017-10-01

Ageing skeletal muscle undergoes chronic denervation, and the neuromuscular junction (NMJ), the key structure that connects motor neuron nerves with muscle cells, shows increased defects with ageing. Previous studies in various species have shown that with ageing, type II fast-twitch skeletal muscle fibres show more atrophy and NMJ deterioration than type I slow-twitch fibres. However, how this process is regulated is largely unknown. A better understanding of the mechanisms regulating skeletal muscle fibre-type specific denervation at the NMJ could be critical to identifying novel treatments for sarcopenia. Cardiac troponin T (cTnT), the heart muscle-specific isoform of TnT, is a key component of the mechanisms of muscle contraction. It is expressed in skeletal muscle during early development, after acute sciatic nerve denervation, in various neuromuscular diseases and possibly in ageing muscle. Yet the subcellular localization and function of cTnT in skeletal muscle is largely unknown. Studies were carried out on isolated skeletal muscles from mice, vervet monkeys, and humans. Immunoblotting, immunoprecipitation, and mass spectrometry were used to analyse protein expression, real-time reverse transcription polymerase chain reaction was used to measure gene expression, immunofluorescence staining was performed for subcellular distribution assay of proteins, and electromyographic recording was used to analyse neurotransmission at the NMJ. Levels of cTnT expression in skeletal muscle increased with ageing in mice. In addition, cTnT was highly enriched at the NMJ region-but mainly in the fast-twitch, not the slow-twitch, muscle of old mice. We further found that the protein kinase A (PKA) RIα subunit was largely removed from, while PKA RIIα and RIIβ are enriched at, the NMJ-again, preferentially in fast-twitch but not slow-twitch muscle in old mice. Knocking down cTnT in fast skeletal muscle of old mice: (i) increased PKA RIα and reduced PKA RIIα at the NMJ; (ii

Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation.

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Okamura, Keisuke; Satou, Shunsuke; Setojima, Keita; Shono, Shinjiro; Miyajima, Shigero; Ishii, Tatsu; Shirai, Kazuyuki; Urata, Hidenori

2018-05-16

BACKGROUND Catheter-based renal sympathetic denervation has been reported to be effective for treatment resistance hypertension in Australia and Europe. However, in the blinded SYMPLICITY HTN-3 trial, renal denervation did not achieve a significant decrease in blood pressure (BP) in comparison to sham controls. There have been various discussions on the factors that influenced this result. CASE REPORT Two men on antihypertensive therapy underwent unilateral radical nephroureterectomy for cancer of the renal pelvis. When the renal artery adventitia was stripped and cauterized just before renal artery ligation, the measured BP of the 2 men increased after stripping adventitia and decreased gradually after cauterization of the renal artery. This was presumably due to removal of renal artery sympathetic nerves, similar to the mechanism of catheter-based renal sympathetic denervation, although anesthesia, fluid infusion, and/or mesenteric traction may have had an influence. CONCLUSIONS A similar strategy involving thoracolumbar sympathectomy was reported about 50 years ago. The clinically significant blood pressure reduction in these patients suggests renal denervation is effective.

The morphological substrate for Renal Denervation: Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study.

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van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

2016-03-01

Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of parasympathetic nerve fibers. To provide a description of the distribution patterns of the renal nerves in man, and, in addition, provide a detailed representation of the relative contribution of the sympathetic, parasympathetic and afferent divisions of the autonomic nervous system. Renal arteries of human cadavers were each divided into four longitudinal segments and immunohistochemically stained with specific markers for afferent, parasympathetic and sympathetic nerves. Nerve fibers were semi-automatically quantified by computerized image analysis, and expressed as cross-sectional area relative to the distance to the lumen. A total of 3372 nerve segments were identified in 8 arteries of 7 cadavers. Sympathetic, parasympathetic and afferent nerves contributed for 73.5% (95% CI: 65.4-81.5%), 17.9% (10.7-25.1%) and 8.7% (5.0-12.3%) of the total cross-sectional nerve area, respectively. Nerves are closer to the lumen in more distal segments and larger bundles that presumably innervate the kidney lie at 1-3.5mm distance from the lumen. The tissue-penetration depth of the ablation required to destroy 50% of the nerve fibers is 2.37 mm in the proximal segment and 1.78 mm in the most distal segments. Sympathetic, parasympathetic and afferent nerves exist in the vicinity of the renal artery. The results warrant further investigation of the role of the parasympathetic nervous system on renal physiology, and may contribute to refinement of the procedure by focusing the ablation on the most distal segment. Copyright © 2015 Elsevier GmbH. All rights reserved.

Effects of renal denervation on end organ damage in hypertensive patients

NARCIS (Netherlands)

Verloop, WL; Vink, Eva E.; Spiering, Wilko; Blankestijn, PJ; Doevendans, Pieter A.; Bots, Michiel L.; Vonken, EPA; Voskuil, Michiel; Leiner, Tim

Background: Renal denervation (RDN) is believed to reduce sympathetic nerve activity and is a potential treatment for resistant hypertension. The present study investigated the effects of RDN on end organ damage (EOD). Design: The present study was a prospective cohort study (registered as

Denervation-Induced Activation of the Ubiquitin-Proteasome System Reduces Skeletal Muscle Quantity Not Quality.

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Baumann, Cory W; Liu, Haiming M; Thompson, LaDora V

2016-01-01

It is well known that the ubiquitin-proteasome system is activated in response to skeletal muscle wasting and functions to degrade contractile proteins. The loss of these proteins inevitably reduces skeletal muscle size (i.e., quantity). However, it is currently unknown whether activation of this pathway also affects function by impairing the muscle's intrinsic ability to produce force (i.e., quality). Therefore, the purpose of this study was twofold, (1) document how the ubiquitin-proteasome system responds to denervation and (2) identify the physiological consequences of these changes. To induce soleus muscle atrophy, C57BL6 mice underwent tibial nerve transection of the left hindlimb for 7 or 14 days (n = 6-8 per group). At these time points, content of several proteins within the ubiquitin-proteasome system were determined via Western blot, while ex vivo whole muscle contractility was specifically analyzed at day 14. Denervation temporarily increased several key proteins within the ubiquitin-proteasome system, including the E3 ligase MuRF1 and the proteasome subunits 19S, α7 and β5. These changes were accompanied by reductions in absolute peak force and power, which were offset when expressed relative to physiological cross-sectional area. Contrary to peak force, absolute and relative forces at submaximal stimulation frequencies were significantly greater following 14 days of denervation. Taken together, these data represent two keys findings. First, activation of the ubiquitin-proteasome system is associated with reductions in skeletal muscle quantity rather than quality. Second, shortly after denervation, it appears the muscle remodels to compensate for the loss of neural activity via changes in Ca2+ handling.

Diffusion tensor imaging and T2 mapping in early denervated skeletal muscle in rats.

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Ha, Dong-Ho; Choi, Sunseob; Kang, Eun-Ju; Park, Hwan Tae

2015-09-01

To evaluate the temporal changes of diffusion tensor imaging (DTI) indices, T2 values, and visual signal intensity on various fat suppression techniques in the early state of denervated skeletal muscle in a rat model. Institutional Animal Care and Use Committee approval was obtained. Sciatic nerves of eight rats were transected for irreversible neurotmesis model. We examined normal lower leg and denervated muscles at 3 days, 1 week, and 2 weeks on a 3 Tesla MR. fractional anisotropy (FA), mean apparent diffusion coefficient (mADC), and T2 values were measured by using DTI and T2 mapping scan. We subjectively classified the signal intensity change on various fat suppression images into the following three grades: negative, suspicious, and definite change. Wilcoxon-sign rank test and Kruskal-Wallis test were used for the comparison of FA, mADC, T2 values. McNemar's test was used for comparing signal intensity change among fat suppression techniques. FA values of denervated muscles at 3 days (0.35 ± 0.06), 1 week (0.29 ± 0.04), and 2 weeks (0.34 ± 0.05) were significantly (P  0.05) change. T2 values were significantly increased at 1 week (38.11 ± 6.42 ms, P = 0.017) and markedly increased at 2 weeks (46.53 ± 5.17 ms, P = 0.012). The grade of visual signal intensity change on chemical shift selective fat saturation, STIR and IDEAL images were identical in all cases (P = 1.000). FA and T2 values can demonstrate the early temporal changes in denervated rat skeletal muscle. © 2014 Wiley Periodicals, Inc.

Mr 40,000 and Mr 39,000 pertussis toxin substrates are increased in surgically denervated dog ventricular myocardium

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Hershberger, R.E.; Feldman, A.M.; Anderson, F.L.; Kimball, J.A.; Wynn, J.R.; Bristow, M.R. (Univ. of Utah School of Medicine, Salt Lake City (USA))

1991-04-01

To test the general hypothesis that cardiac innervation may participate in myocardial G protein regulation, we examined the effects of complete intrapericardial surgical denervation or sham operation in dogs. In particulate fractions of dog left ventricular (LV) myocardium harvested 28-33 days after denervation or sham operation, Mr 40,000 and Mr 39,000 pertussis toxin-sensitive substrates (G proteins) were increased by 31% (1.31 +/- 0.084 vs 1.00 +/- 0.058 OD, arbitrary units, p less than 0.01) and 40% (1.40 +/- 0.117 vs. 1.000 +/- 0.084 OD, arbitrary units, p less than 0.02), respectively, as compared with sham-operated controls. The Mr 40,000 pertussis toxin-sensitive band comigrated with a pertussis toxin-sensitive substrate in human erythrocyte membranes known to contain an alpha Gi species. In these same preparations basal, GTP and GppNHp stimulated adenylate cyclase activities were decreased in denervated heart by 20, 26, and 19%, respectively, consistent with increased activity of an inhibitory G protein. In contrast, Gs function was not altered, because cyc(-) membranes reconstituted with membrane extracts and fluoride and beta-receptor-stimulated adenylate cyclase activity were not different between groups. Furthermore, adenylate cyclase catalytic subunit function as assessed with forskolin and manganese stimulation was not different between preparations of control and denervated heart. We conclude that in preparations of surgically denervated dog myocardium Mr 40,000 and Mr 39,000 pertussis toxin-sensitive G proteins are increased by 31 and 40%, respectively, and that functional alterations in adenylate cyclase activity exist, consistent with increased inhibitory G-protein function.

Mr 40,000 and Mr 39,000 pertussis toxin substrates are increased in surgically denervated dog ventricular myocardium

International Nuclear Information System (INIS)

Hershberger, R.E.; Feldman, A.M.; Anderson, F.L.; Kimball, J.A.; Wynn, J.R.; Bristow, M.R.

1991-01-01

To test the general hypothesis that cardiac innervation may participate in myocardial G protein regulation, we examined the effects of complete intrapericardial surgical denervation or sham operation in dogs. In particulate fractions of dog left ventricular (LV) myocardium harvested 28-33 days after denervation or sham operation, Mr 40,000 and Mr 39,000 pertussis toxin-sensitive substrates (G proteins) were increased by 31% (1.31 +/- 0.084 vs 1.00 +/- 0.058 OD, arbitrary units, p less than 0.01) and 40% (1.40 +/- 0.117 vs. 1.000 +/- 0.084 OD, arbitrary units, p less than 0.02), respectively, as compared with sham-operated controls. The Mr 40,000 pertussis toxin-sensitive band comigrated with a pertussis toxin-sensitive substrate in human erythrocyte membranes known to contain an alpha Gi species. In these same preparations basal, GTP and GppNHp stimulated adenylate cyclase activities were decreased in denervated heart by 20, 26, and 19%, respectively, consistent with increased activity of an inhibitory G protein. In contrast, Gs function was not altered, because cyc(-) membranes reconstituted with membrane extracts and fluoride and beta-receptor-stimulated adenylate cyclase activity were not different between groups. Furthermore, adenylate cyclase catalytic subunit function as assessed with forskolin and manganese stimulation was not different between preparations of control and denervated heart. We conclude that in preparations of surgically denervated dog myocardium Mr 40,000 and Mr 39,000 pertussis toxin-sensitive G proteins are increased by 31 and 40%, respectively, and that functional alterations in adenylate cyclase activity exist, consistent with increased inhibitory G-protein function

Renal denervation for improving outcomes of catheter ablation in patients with atrial fibrillation and hypertension: early experience.

Science.gov (United States)

Pokushalov, Evgeny; Romanov, Alexander; Katritsis, Demosthenes G; Artyomenko, Sergey; Bayramova, Sevda; Losik, Denis; Baranova, Vera; Karaskov, Alexander; Steinberg, Jonathan S

2014-07-01

The potential role of renal denervation (RD) in patients with AF and less severe hypertension is unknown. The purpose of this study was to assess the potential role of RD as an adjunct to pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) and moderate resistant or severe resistant hypertension. The data for this study were obtained from 2 different prospective randomized studies, analyzed by meta-analysis. Patients with paroxysmal AF or persistent AF and moderate resistant hypertension (office blood pressure BP ≥140/90 mm Hg and hypertension (≥160/100 mm Hg; second study; n = 38) were randomized to PVI or PVI with RD. At 12 months, 26 of the 41 PVI with RD patients (63%) were AF-free vs 16 of the 39 patients (41%) in the PVI-only group (P = .014). In patients with severe hypertension, 11 of the 18 PVI with RD patients (61%) vs 5 of the 18 PVI-only patients (28%) were AF-free (P = .03). For moderate hypertension, the differences were less dramatic: 11 of 21 (52%) vs 15 of 23 (65%) when RD added (P = .19). The superior efficacy of adding RD was most apparent in persistent AF and severe hypertension (hazard ratio 0.25, confidence interval 0.09-0.72, P = .01). Duration of the procedure and fluoroscopy were nonsignificantly longer in the RD group. RD may improve the results of PVI in patients with persistent AF and/or severe resistant hypertension. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Adrenergic receptors and gastric secretion in dogs. Is a "tonic balance" relationship between vagal and beta 2-adrenergic activity a possibility?

DEFF Research Database (Denmark)

Gottrup, F; Hovendal, C; Bech, K

1984-01-01

The relative influence of adrenergic receptors on gastric acid secretion in the dog stomach with different vagal activity or "tone" is almost unknown. beta-adrenoceptors seem to be most important for the direct effect of adrenergic stimulation on acid secretion. In this study the effects...... acid secretion was not influenced significantly by beta-blockade. Similar dose-response curves were found for non-vagotomized dogs with high beta 2-adrenergic tone and dogs with low vagal tone (vagotomy) after pentagastrin and histamine stimulated acid secretion. This study indicates...... that a counterbalance between beta 2-adrenergic and cholinergic vagal tone exists. A "tonic balance theory" is suggested and is probably involved in the resulting acid secretion after vagotomy....

Low to high frequency ratio of heart rate variability spectra fails to describe sympatho-vagal balance in cardiac patients.

Science.gov (United States)

Milicević, Goran

2005-06-01

Heart rate variability (HRV) reflects an influence of autonomic nervous system on heart work. In healthy subjects, ratio between low and high frequency components (LF/HF ratio) of HRV spectra represents a measure of sympatho-vagal balance. The ratio was defined by the authorities as an useful clinical tool, but it seems that it fails to summarise sympatho-vagal balance in a clinical setting. Value of the method was re-evaluated in several categories of cardiac patients. HRV was analysed from 24-hour Holter ECGs in 132 healthy subjects, and 2159 cardiac patients dichotomised by gender, median of age, diagnosis of myocardial infarction or coronary artery surgery, left ventricular systolic function and divided by overall HRV into several categories. In healthy subjects, LF/HF ratio correlated with overall HRV negatively, as expected. The paradoxical finding was obtained in cardiac patients; the lower the overall HRV and the time-domain indices of vagal modulation activity were the lower the LF/HF ratio was. If used as a measure of sympatho-vagal balance, long-term recordings of LF/HF ratio contradict to clinical finding and time-domain HRV indices in cardiac patients. The ratio cannot therefore be used as a reliable marker of autonomic activity in a clinical setting.

Renal denervation in moderate treatment-resistant hypertension.

Science.gov (United States)

Ott, Christian; Mahfoud, Felix; Schmid, Axel; Ditting, Tilmann; Sobotka, Paul A; Veelken, Roland; Spies, Aline; Ukena, Christian; Laufs, Ulrich; Uder, Michael; Böhm, Michael; Schmieder, Roland E

2013-11-12

This study sought to investigate the effect of renal denervation (RDN) in patients with treatment-resistant hypertension according to the established definition (Joint National Committee VII and European Society of Hypertension/European Society of Cardiology guidelines), that is, office blood pressure (BP) ≥140/90 mm Hg (with at least three antihypertensive drugs, including a diuretic, in adequate doses) and confirmed by 24-h ambulatory BP monitoring (ABPM). RDN emerged as an innovative interventional antihypertensive therapy. However, so far, only patients with severe hypertension (systolic BP ≥160 mm Hg or ≥150 mm Hg for patients with type 2 diabetes) have been investigated. In this study, there were 54 patients with moderate treatment-resistant hypertension (office BP ≥140/90 mm Hg and who underwent catheter-based RDN using the Symplicity catheter (Medtronic Inc., Mountain View, California). Patients were treated with 5.1 ± 1.4 antihypertensive drugs on average. Office BP was significantly reduced by 13/7 mm Hg 6 months after RDN (systolic: 151 ± 6 mm Hg vs. 138 ± 21 mm Hg, p who underwent ABPM 6 months after treatment, there was a reduction in average 24-h ABPM by 14/7 mm Hg (systolic: 150 ± 16 mm Hg vs. 136 ± 16 mm Hg, p hypertension. (Renal Denervation in Treatment Resistant Hypertension; NCT01687725). Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Electrically induced release of acetylcholine from denervated Schwann cells.

Science.gov (United States)

Dennis, M J; Miledi, R

1974-03-01

1. Focal electrical stimulation of Schwann cells at the end-plates of denervated frog muscles elicited slow depolarizations of up to 30 mV in the muscle fibres. This response is referred to as a Schwann-cell end-plate potential (Schwann-e.p.p.).2. Repeated stimulation sometimes evoked further Schwann-e.p.p.s, but they were never sustained for more than 30 pulses. Successive e.p.p.s varied in amplitude and time course independently of the stimulus.3. The Schwann-e.p.p.s were reversibly blocked by curare, suggesting that they result from a release of acetylcholine (ACh) by the Schwann cells.4. ACh release by electrical stimulation did not seem to occur in quantal form and was not dependent on the presence of calcium ions in the external medium; nor was it blocked by tetrodotoxin.5. Stimulation which caused release of ACh also resulted in extensive morphological disruption of the Schwann cells, as seen with both light and electron microscopy.6. It is concluded that electrical stimulation of denervated Schwann cells causes break-down of the cell membrane and releases ACh, presumably in molecular form.

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation

Energy Technology Data Exchange (ETDEWEB)

VonAchen, Paige [Minneapolis Heart Institute and Foundation at Abbott Northwestern Hospital, Minneapolis, MN (United States); Hamann, Jason [Boston Scientific Corporation, Maple Grove, MN (United States); Houghland, Thomas; Lesser, John R.; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F. [Minneapolis Heart Institute and Foundation at Abbott Northwestern Hospital, Minneapolis, MN (United States); Daniels, Mary [Vital Images/Toshiba, Minnetonka, MN (United States); Schwartz, Robert S., E-mail: rss@rsschwartz.com [Minneapolis Heart Institute and Foundation at Abbott Northwestern Hospital, Minneapolis, MN (United States)

2016-10-15

Objective: The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Background: Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Methods: Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Results: Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p = 0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p = 0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p = 0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Conclusions: Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation

International Nuclear Information System (INIS)

VonAchen, Paige; Hamann, Jason; Houghland, Thomas; Lesser, John R.; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F.; Daniels, Mary; Schwartz, Robert S.

2016-01-01

Objective: The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Background: Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Methods: Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Results: Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p = 0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p = 0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p = 0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Conclusions: Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in

Renal sympathetic denervation for resistant hypertension.

Science.gov (United States)

Froeschl, Michael; Hadziomerovic, Adnan; Ruzicka, Marcel

2013-05-01

Resistant hypertension is an increasingly prevalent health problem associated with important adverse cardiovascular outcomes. The pathophysiology that underlies this condition involves increased function of both the sympathetic nervous system and the renin-angiotensin II-aldosterone system. A crucial link between these 2 systems is the web of sympathetic fibres that course within the adventitia of the renal arteries. These nerves can be targeted by applying radiofrequency energy from the lumen of the renal arteries to renal artery walls (percutaneous renal sympathetic denervation [RSD]), an approach that has attracted great interest. This paper critically reviews the evidence supporting the use of RSD. Small studies suggest that RSD can produce dramatic blood pressure reductions: In the randomized Symplicity HTN-2 trial of 106 patients, the mean fall in blood pressure at 6 months in patients who received the treatment was 32/12 mm Hg. However, there are limitations to the evidence for RSD in the treatment of resistant hypertension. These include the small number of patients studied; the lack of any placebo-controlled evidence; the fact that blood pressure outcomes were based on office assessments, as opposed to 24-hour ambulatory monitoring; the lack of longer-term efficacy data; and the lack of long-term safety data. Some of these concerns are being addressed in the ongoing Renal Denervation in Patients With Uncontrolled Hypertension (Symplicity HTN-3) trial. The first percutaneous RSD system was approved by Health Canada in the spring of 2012. But until more and better-quality data are available, this procedure should generally be reserved for those patients whose resistant hypertension is truly uncontrolled. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Cholinergic denervation of the hippocampal formation does not produce long-term changes in glucose metabolism

International Nuclear Information System (INIS)

Harrell, L.E.; Davis, J.N.

1984-01-01

Decreased glucose metabolism is found in Alzheimer's disease associated with a loss of cholinergic neurons. The relationship between the chronic cholinergic denervation produced by medial septal lesions and glucose metabolism was studied using 2-deoxy-D-[ 3 H]glucose in the rat hippocampal formation. Hippocampal glucose metabolism was increased 1 week after medial septal lesions. Three weeks after lesions, glucose metabolism was profoundly suppressed in all regions. By 3 months, intraregional hippocampal glucose metabolism had returned to control values. Our results demonstrate that chronic cholinergic denervation of the hippocampal formation does not result in permanent alterations of metabolic activity

Effect of denervation and ischemia reperfusion injury on serum nitricoxide levels in rats

International Nuclear Information System (INIS)

Ozsoy, U.; Sindel, S.; Oygur, N.; Akbas, H.; Mutluay, R.

2008-01-01

Objective was to evaluate the effect of renal denervation and serumnitric oxide level with a different time course of renal ischemia-reperfusioninjury. Thirty-six male Wistar rats were randomized into 6 groups. All ratsunderwent right nephrectomy to create a single kidney model. Renal denervatedand innerved rats were subjected to renal clamping for 30-60 minutes. Thestudy was performed in the Department of Anatomy, Akdeniz University,Antalya, Turkey, between June and November 2005. Combined effects ofdenervation and ischemia may cause significant increase in serum nitric oxidelevels and decrease in glomerular filtration rates. Our results indicate thatkidney denervation did not cause any changes in renal functions, but withischemia it worsens the deleterious effect of ischemia-reperfusion injury andcauses a significant increase in serum nitric oxide levels. (author)

Research on alteration of neurons in vagal nuclei in medulla oblongata in newborns with respiratory distress.

Science.gov (United States)

Islami, Hilmi; Shabani, Ragip; Shabani, Driton; Dacaj, Ramadan; Manxhuka, Suzana; Azemi, Mehmedali; Krasniqi, Shaip; Kurtishi, Ilir

2011-01-01

Neuronal and axonal degenerative changes in motor vagal neurons (DMNV) and sensory vagal neurons (nTS) in the medulla oblongata in newborns were studied. Material was taken from the autopsies of newborns, live and dead newborns, in different gestational weeks (aborted, immature, premature and mature). 46 cases were studied. Material for research was taken from the medulla oblongata and lung tissue. Serial horizontal incisions were made in the medulla oblongata (± 4 mm), commencing from the obex, where the DMNV and nTS vagal nuclei were explored. Fixed cuttings in buffered formalin (10%) were used for histochemical staining. Serial cuttings were done with a microtome (7 µm). Pulmonary infections, being significant (p medulla oblongata in newborns in different gestational weeks are more emphasized in matures in comparison to aborted and immature (p < 0.05). Depending on the lifetime of dead newborns, neuronal morphological changes in vagus nerve nuclei are significant (p < 0.05). Therefore, it can be concluded that pulmonary infections are often caused due to dramatic respiratory distress in newborns, while hypoxaemic changes in the population of vagus nerve neurons in respiratory distress are more emphasized in matures.

Myostatin propeptide gene delivery by gene gun ameliorates muscle atrophy in a rat model of botulinum toxin-induced nerve denervation.

Science.gov (United States)

Tsai, Sen-Wei; Tung, Yu-Tang; Chen, Hsiao-Ling; Yang, Shang-Hsun; Liu, Chia-Yi; Lu, Michelle; Pai, Hui-Jing; Lin, Chi-Chen; Chen, Chuan-Mu

2016-02-01

Muscle atrophy is a common symptom after nerve denervation. Myostatin propeptide, a precursor of myostatin, has been documented to improve muscle growth. However, the mechanism underlying the muscle atrophy attenuation effects of myostatin propeptide in muscles and the changes in gene expression are not well established. We investigated the possible underlying mechanisms associated with myostatin propeptide gene delivery by gene gun in a rat denervation muscle atrophy model, and evaluated gene expression patterns. In a rat botulinum toxin-induced nerve denervation muscle atrophy model, we evaluated the effects of wild-type (MSPP) and mutant-type (MSPPD75A) of myostatin propeptide gene delivery, and observed changes in gene activation associated with the neuromuscular junction, muscle and nerve. Muscle mass and muscle fiber size was moderately increased in myostatin propeptide treated muscles (pmyostatin propeptide gene delivery, especially the mutant-type of MSPPD75A, attenuates muscle atrophy through myogenic regulatory factors and acetylcholine receptor regulation. Our data concluded that myostatin propeptide gene therapy may be a promising treatment for nerve denervation induced muscle atrophy. Copyright © 2016 Elsevier Inc. All rights reserved.

Lesion size in relation to ablation site during radiofrequency ablation

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, A

1998-01-01

This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation was perfor......This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation...... was performed during two different flow-velocities in a tissue bath, while electrode contact pressure and position were unchanged. Target temperature was 80 degrees C. Obtained tip temperature, power consumption and lesion dimensions were measured. In vivo lesion volume, depth and width were found significantly.......61 in vitro). We conclude that during temperature controlled radiofrequency ablation lesion size differs for septal and apical left ventricular applications. Differences in convective cooling might play an important role in this respect. This is supported by our in vitro experiments, where increased...

Renal Denervation Using an Irrigated Catheter in Patients with Resistant Hypertension: A Promising Strategy?

International Nuclear Information System (INIS)

Armaganijan, Luciana; Staico, Rodolfo; Moraes, Aline; Abizaid, Alexandre; Moreira, Dalmo; Amodeo, Celso; Sousa, Márcio; Borelli, Flávio; Armaganijan, Dikran; Sousa, J. Eduardo; Sousa, Amanda

2014-01-01

Systemic hypertension is an important public health problem and a significant cause of cardiovascular mortality. Its high prevalence and the low rates of blood pressure control have resulted in the search for alternative therapeutic strategies. Percutaneous renal sympathetic denervation emerged as a perspective in the treatment of patients with resistant hypertension. To evaluate the feasibility and safety of renal denervation using an irrigated catheter. Ten patients with resistant hypertension underwent the procedure. The primary endpoint was safety, as assessed by periprocedural adverse events, renal function and renal vascular abnormalities at 6 months. The secondary endpoints were changes in blood pressure levels (office and ambulatory monitoring) and in the number of antihypertensive drugs at 6 months. The mean age was 47.3 (± 12) years, and 90% of patients were women. In the first case, renal artery dissection occurred as a result of trauma due to the long sheath; no further cases were observed after technical adjustments, thus showing an effect of the learning curve. No cases of thrombosis/renal infarction or death were reported. Elevation of serum creatinine levels was not observed during follow-up. At 6 months, one case of significant renal artery stenosis with no clinical consequences was diagnosed. Renal denervation reduced office blood pressure levels by 14.6/6.6 mmHg, on average (p = 0.4 both for systolic and diastolic blood pressure). Blood pressure levels on ambulatory monitoring decreased by 28/17.6 mmHg (p = 0.02 and p = 0.07 for systolic and diastolic blood pressure, respectively). A mean reduction of 2.1 antihypertensive drugs was observed. Renal denervation is feasible and safe in the treatment of resistant systemic arterial hypertension. Larger studies are required to confirm our findings

Renal Denervation Using an Irrigated Catheter in Patients with Resistant Hypertension: A Promising Strategy?

Energy Technology Data Exchange (ETDEWEB)

Armaganijan, Luciana, E-mail: luciana-va@hotmail.com; Staico, Rodolfo; Moraes, Aline; Abizaid, Alexandre; Moreira, Dalmo; Amodeo, Celso; Sousa, Márcio; Borelli, Flávio; Armaganijan, Dikran; Sousa, J. Eduardo; Sousa, Amanda [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

2014-04-15

Systemic hypertension is an important public health problem and a significant cause of cardiovascular mortality. Its high prevalence and the low rates of blood pressure control have resulted in the search for alternative therapeutic strategies. Percutaneous renal sympathetic denervation emerged as a perspective in the treatment of patients with resistant hypertension. To evaluate the feasibility and safety of renal denervation using an irrigated catheter. Ten patients with resistant hypertension underwent the procedure. The primary endpoint was safety, as assessed by periprocedural adverse events, renal function and renal vascular abnormalities at 6 months. The secondary endpoints were changes in blood pressure levels (office and ambulatory monitoring) and in the number of antihypertensive drugs at 6 months. The mean age was 47.3 (± 12) years, and 90% of patients were women. In the first case, renal artery dissection occurred as a result of trauma due to the long sheath; no further cases were observed after technical adjustments, thus showing an effect of the learning curve. No cases of thrombosis/renal infarction or death were reported. Elevation of serum creatinine levels was not observed during follow-up. At 6 months, one case of significant renal artery stenosis with no clinical consequences was diagnosed. Renal denervation reduced office blood pressure levels by 14.6/6.6 mmHg, on average (p = 0.4 both for systolic and diastolic blood pressure). Blood pressure levels on ambulatory monitoring decreased by 28/17.6 mmHg (p = 0.02 and p = 0.07 for systolic and diastolic blood pressure, respectively). A mean reduction of 2.1 antihypertensive drugs was observed. Renal denervation is feasible and safe in the treatment of resistant systemic arterial hypertension. Larger studies are required to confirm our findings.

Cardiac ablation

Directory of Open Access Journals (Sweden)

Kelly Ratheal

2016-01-01

Full Text Available Cardiac ablation is a procedure that uses either radiofrequency or cryothermal energy to destroy cells in the heart to terminate and/or prevent arrhythmias. The indications for cardiac catheter ablation include refractory, symptomatic arrhythmias, with more specific guidelines for atrial fibrillation in particular. The ablation procedure itself involves mapping the arrhythmia and destruction of the aberrant pathway in an effort to permanently prevent the arrhythmia. There are many types of arrhythmias, and they require individualized approaches to ablation based on their innately different electrical pathways. Ablation of arrhythmias, such as Wolff-Parkinson-White syndrome, AV nodal reentrant tachycardia, and atrial-fibrillation, is discussed in this review. Ablation has a high success rate overall and minimal complication rates, leading to improved quality of life in many patients.

Percutaneous renal sympathetic nerve ablation for loin pain haematuria syndrome.

Science.gov (United States)

Gambaro, Giovanni; Fulignati, Pierluigi; Spinelli, Alessio; Rovella, Valentina; Di Daniele, Nicola

2013-09-01

Loin pain haematuria syndrome (LPHS) is a severe renal pain condition of uncertain origin and often resistant to treatment. Nephrectomy and renal autotrasplantation have occasionally been performed in very severe cases. Its pathogenesis is controversial. A 40-year-old hypertensive lady was diagnosed with LPHS after repeated diagnostic imaging procedures had ruled out any renal, abdominal or spinal conditions to justify pain. Notwithstanding treatment with three drugs, she had frequent hypertensive crises during which the loin pain was dramatically exacerbated. Vascular causes of the pain and hypertension were investigated and excluded. Her renal function was normal. The patient was referred to a multidisciplinary pain clinic, but had no significant improvement in her pain symptoms despite the use of non-steroidal anti-inflammatory drugs, adjuvant antidepressants and opioid-like agents. The pain and the discomfort were so severe that her quality of life was very poor, and her social and professional activities were compromised. Nephrectomy and renal autotransplantation have occasionally been performed in these cases. Since visceral pain signals flow through afferent sympathetic fibres, we felt that percutaneous catheter-based radiofrequency ablation of the renal sympathetic nerve fibres (recently introduced for the treatment of drug-resistant hypertension) could be valuable for pain relief. We treated the patient with radiofrequency ablation (Medtronic Symplicity Catheter) applied only to the right renal artery. After a 6-month follow-up, the patient is pain free and normotensive with all drugs withdrawn. She has experienced no hypertensive crises in the meantime. This observation suggests that percutaneous sympathetic denervation could prove to be an effective mini-invasive strategy for the treatment of chronic renal pain, and LPHS in particular.

Renal Denervation, Hope or Hype? : Studies on patient selection and mechanisms

NARCIS (Netherlands)

Vink, E.E.

2014-01-01

The general objective of this thesis was to determine which patients are most likely to benefit most from treatment with RDN and to study the effects of renal denervation (RDN). This thesis is subdivided into three parts. Part I focused on pathophysiologic studies on renal oxygenation and the

Single strip lesions radiofrequency denervation for treatment of sacroiliac joint pain: two years' results.

Science.gov (United States)

Bellini, Martina; Barbieri, Massimo

2016-01-01

Sacroiliac joint pain can be managed by intra-articular injections or radiofrequency of its innervation. Single strip lesions radiofrequency denervation is a new system. The objective of this study was to present one of the first utilizations of this innovative technique. 60 patients who met the diagnostic criteria for sacroiliac joint syndrome were enrolled in the study. In total, 102 single strip lesions radiofrequency denervations were performed. Pain intensity was measured with the Oswestry low back pain disability questionnaire and the Oswestry Disability Index whose scores were assessed at 1, 3, 6 and 12 months after the procedure. 91.8 % of the 102 radiofrequency treatments resulted in a reduction of more than 50% pain intensity relief at 1 month, 81.6% at 3 months and 59.16% at 6 months. In 35.7% of cases, the relief was continuative up to 1 year. No relief was observed in 12.24% of cases. The ODI scores improved significantly 1 month after the procedure, compared with the baseline scores. The ODI scores after 6 months improved very clearly compared with the baseline scores and with the 3-month scores. Single strip lesions radiofrequency denervation using the Simplicity III probe is a potential modality for intermediate term relief for patients with sacroiliac pain.

Therapeutic efficacy of percutaneous radiofrequency ablation versus microwave ablation for hepatocellular carcinoma.

Directory of Open Access Journals (Sweden)

Lei Zhang

Full Text Available The aim of this study was to investigate the therapeutic efficacy of percutaneous radiofrequency (RF ablation versus microwave (MW ablation for hepatocellular carcinoma (HCC measuring ≤ 5 cm in greatest diameter. From January 2006 to December 2006, 78 patients had undergone RF ablation whereas 77 had undergone MW ablation. Complete ablation (CA, local tumour progression (LTP and distant recurrence (DR were compared. The overall survival curves were calculated with the Kaplan-Meier technique and compared with the log-rank test. The CA rate was 83.4% (78/93 for RF ablation and 86.7%(91/105 for MW ablation. The LTP rate was 11.8% (11/93 for RF ablation and 10.5% (11/105 for MW ablation. DR was found in 51 (65.4% in the RF ablation and 62 (80.5% in the MW ablation. There was no significant difference in the 1-, 3-, and 5-year overall survival rates (P = 0.780 and the 1-, 3-, and 5-year disease-free survival rates (P = 0.123 between RF and MW ablation. At subgroup analyses, for patients with tumors ≤ 3.0 cm, there was no significant difference in the 1-, 3-, and 5-year overall survival rates (P = 0.067 and the corresponding disease-free survival rates(P = 0.849. For patients with tumor diameters of 3.1-5.0 cm, the 1-, 3-, and 5-year overall survival rates were 87.1%, 61.3%, and 40.1% for RF ablation and 85.4%, 36.6%, and 22% for MW ablation, with no significant difference (P = 0.068. The corresponding disease-free survival rates were 74.2%, 54.8%, and 45.2% for the RF ablation group and 53.3%, 26.8%, and 17.1% for the MW ablation group. The disease-free survival curve for the RF ablation group was significantly better than that for the MW ablation group (P = 0.018. RF ablation and MW ablation are both effective methods in treating hepatocellular carcinomas, with no significant differences in CA, LTP, DR, and overall survival.

Does sensory stimulation threshold affect lumbar facet radiofrequency denervation outcomes? A prospective clinical correlational study.

Science.gov (United States)

Cohen, Steven P; Strassels, Scott A; Kurihara, Connie; Lesnick, Ivan K; Hanling, Steven R; Griffith, Scott R; Buckenmaier, Chester C; Nguyen, Conner

2011-11-01

Radiofrequency facet denervation is one of the most frequently performed procedures for chronic low back pain. Although sensory stimulation is generally used as a surrogate measure to denote sufficient proximity of the electrode to the nerve, no study has examined whether stimulation threshold influences outcome. We prospectively recorded data in 61 consecutive patients undergoing lumbar facet radiofrequency denervation who experienced significant pain relief after medial branch blocks. For each nerve lesioned, multiple attempts were made to maximize sensory stimulation threshold (SST). Mean SST was calculated on the basis of the lowest stimulation perceived at 0.1-V increments for each medial branch. A positive outcome was defined as a ≥50% reduction in back pain coupled with a positive satisfaction score lasting ≥3 months. The relationship between mean SST and denervation outcomes was evaluated via a receiver's operating characteristic (ROC) curve, and stratifying outcomes on the basis of various cutoff values. No correlation was noted between mean SST and pain relief at rest (Pearson's r=-0.01, 95% confidence interval [CI]: -0.24 to 0.23, P=0.97), with activity (r=-0.17, 95% CI: -0.40 to 0.07, P=0.20), or a successful outcome. No optimal SST could be identified. There is no significant relationship between mean SST during lumbar facet radiofrequency denervation and treatment outcome, which may be due to differences in general sensory perception. Because stimulation threshold was optimized for each patient, these data cannot be interpreted to suggest that sensory testing should not be performed, or that high sensory stimulation thresholds obtained on the first attempt should be deemed acceptable.

Renal sympathetic nerve ablation for treatment-resistant hypertension

Science.gov (United States)

Krum, Henry; Schlaich, Markus; Sobotka, Paul

2013-01-01

Hypertension is a major risk factor for increased cardiovascular events with accelerated sympathetic nerve activity implicated in the pathogenesis and progression of disease. Blood pressure is not adequately controlled in many patients, despite the availability of effective pharmacotherapy. Novel procedure- as well as device-based strategies, such as percutaneous renal sympathetic nerve denervation, have been developed to improve blood pressure in these refractory patients. Renal sympathetic denervation not only reduces blood pressure but also renal as well as systemic sympathetic nerve activity in such patients. The reduction in blood pressure appears to be sustained over 3 years after the procedure, which suggests absence of re-innervation of renal sympathetic nerves. Safety appears to be adequate. This approach may also have potential in other disorders associated with enhanced sympathetic nerve activity such as congestive heart failure, chronic kidney disease and metabolic syndrome. This review will focus on the current status of percutaneous renal sympathetic nerve denervation, clinical efficacy and safety outcomes and prospects beyond refractory hypertension. PMID:23819768

Denervation of the lateral humeral epicondyle for treatment of chronic lateral epicondylitis.

Science.gov (United States)

Rose, Nicholas E; Forman, Scott K; Dellon, A Lee

2013-02-01

Chronic lateral epicondylitis remains a treatment challenge. Traditional surgical treatments for lateral epicondylitis involve variations of the classic Nirschl lateral release. Anatomic studies reveal that the posterior branch or branches of the posterior cutaneous nerve of the forearm consistently innervate the lateral humeral epicondyle. We undertook the present study to determine the effectiveness of denervation of the lateral humeral epicondyle in treating chronic lateral epicondylitis. An institutional review board-approved prospective study included 30 elbows in 26 patients. Inclusion criteria included failure to respond to nonoperative treatment for more than 6 months and improvement in grip strength and in visual analog pain scale after diagnostic nerve block of the posterior branches of the posterior cutaneous nerve of the forearm proximal to the lateral humeral epicondyle. We excluded patients who had undergone previous surgery for lateral epicondylitis. Outcome measures included visual analog pain scale and grip strength testing. Denervation surgery involved identification and transection of the posterior cutaneous nerve of the forearm branches with implantation into the triceps. The presence of radial tunnel syndrome was noted but did not affect inclusion criteria; if it was present, we did not correct it surgically. We used no postoperative splinting and permitted immediate return to activities of daily living. At a mean of 28 months of follow-up, the average visual analog scale score decreased from 7.9 to 1.9. Average grip strength with the elbow extended improved from 13 to 24 kg. A total of 80% of patients had good or excellent results, as defined by an improvement of 5 or more points on the visual analog scale for pain. Denervation of the lateral epicondyle was effective in relieving pain in 80% of patients with chronic lateral epicondylitis who had a positive response to a local anesthetic block of the posterior branches of the posterior

Impact of gonadectomy on sympatho-vagal balance in male and female normotensive rat

NARCIS (Netherlands)

Pijacka, Wioletta; Clifford, Bethan; Walas, Dawid; Tilburgs, Chantal; Joles, Jaap A; McMullen, Sarah; Langley-Evans, Simon C

OBJECTIVE: It is well established that autonomic nervous system and sympatho-vagal balance plays an important role in maintaining arterial blood pressure (ABP) (Salman IM., 2016) and that autonomic regulation of ABP differs between males and females (Hart EC et al., 2014). We hypothesised that sex

Vagal afferents contribute to exacerbated airway responses following ozone and allergen challenge.

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Schelegle, Edward S; Walby, William F

2012-05-31

Brown-Norway rats (n=113) sensitized and challenged with nDer f 1 allergen were used to examine the contribution of lung sensory nerves to ozone (O(3)) exacerbation of asthma. Prior to their third challenge rats inhaled 1.0ppm O(3) for 8h. There were three groups: (1) control; (2) vagus perineural capsaicin treatment (PCT) with or without hexamethonium; and (3) vagotomy. O(3) inhalation resulted in a significant increase in lung resistance (R(L)) and an exaggerated response to subsequent allergen challenge. PCT abolished the O(3)-induced increase in R(L) and significantly reduced the increase in R(L) induced by a subsequent allergen challenge, while hexamethonium treatment reestablished bronchoconstriction induced by allergen challenge. Vagotomy resulted in a significant increase in the bronchoconstriction induced by O(3) inhalation and subsequent challenge with allergen. In this model of O(3) exacerbation of asthma, vagal C-fibers initiate reflex bronchoconstriction, vagal myelinated fibers initiate reflex bronchodilation, and mediators released within the airway initiate bronchoconstriction. Copyright © 2012 Elsevier B.V. All rights reserved.

The Relationship between a New Biomarker of Vagal Neuroimmunomodulation and Survival in Two Fatal Cancers

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Y. Gidron

2018-01-01

Full Text Available Background. The vagus nerve may slow tumor progression because it inhibits inflammation. This study examined the relationship between a new vagal neuroimmunomodulation (NIM index and survival in fatal cancers. Method. We retroactively derived markers of vagal nerve activity indexed by heart rate variability (HRV, specifically the root mean square of successive differences (RMSSD, from patients’ electrocardiograms near diagnosis. The NIM index was the ratio of RMSSD to C-reactive protein levels (RMSSD/CRP. Sample 1 included 202 Belgian patients with advanced pancreatic cancer (PC, while sample 2 included 71 Belgian patients with non-small cell lung cancer (NSCLC. In both samples, we examined the overall survival, while in sample 2, we additionally examined the survival time in deceased patients. Results. In PC patients, in a multivariate Cox regression controlling for confounders, the NIM index had a protective relative risk (RR of 0.68 and 95% confidence interval (95% CI of 0.51–0.92. In NSCLC patients, the NIM index also had a protective RR of 0.53 and 95% CI of 0.32–0.88. Finally, in NSCLC, patients with a higher NIM index survived more days (475.2 than those with lower NIM (285.1 (p<0.05. Conclusions. The NIM index, reflecting vagal modulation of inflammation, may be a new independent prognostic biomarker in fatal cancers.

Electroacupuncture improves burn-induced impairment in gastric motility mediated via the vagal mechanism in rats.

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Song, J; Yin, J; Sallam, H S; Bai, T; Chen, Y; Chen, J D Z

2013-10-01

Delayed gastric emptying (GE) is common in patients with severe burns. This study was designed to investigate effects and mechanisms of electroacupuncture (EA) on gastric motility in rats with burns. Male rats (intact and vagotomized) were implanted with gastric electrodes, chest and abdominal wall electrodes for investigating the effects of EA at ST-36 (stomach-36 or Zusanli) on GE, gastric slow waves, autonomic functions, and plasma interleukin 6 (IL-6) 6 and 24 h post severe burns. (i) Burn delayed GE (P Electroacupuncture improved GE 6 and 24 h post burn (P Electroacupuncture improved burn-induced gastric dysrhythmia. The percentage of normal slow waves was increased with EA 6 and 24 h post burn (P = 0.02). (iii) Electroacupuncture increased vagal activity assessed by the spectral analysis of heart rate variability (HRV). The high-frequency component reflecting vagal component was increased with EA 6 (P = 0.004) and 24 h post burn (P = 0.03, vs sham-EA). (iv) Electroacupuncture attenuated burn-induced increase in plasma IL-6 at both 6 (P = 0.03) and 24 h post burn (P = 0.003). Electroacupuncture at ST-36 improves gastric dysrhythmia and accelerates GE in rats with burns. The improvement seems to be mediated via the vagal pathway involving the inflammatory cytokine IL-6. © 2013 John Wiley & Sons Ltd.

Renal denervation by intravascular ultrasound: Preliminary in vivo study

Science.gov (United States)

Sinelnikov, Yegor; McClain, Steve; Zou, Yong; Smith, David; Warnking, Reinhard

2012-10-01

Ultrasound denervation has recently become a subject of intense research in connection with the treatment of complex medical conditions including neurological conditions, development of pain management, reproduction of skin sensation, neuropathic pain and spasticity. The objective of this study is to investigate the use of intravascular ultrasound to produce nerve damage in renal sympathetic nerves without significant injury to the renal artery. This technique may potentially be used to treat various medical conditions, such as hypertension. The study was approved by the Institutional Animal Care and Use Committee. Ultrasound was applied to renal nerves of the swine model for histopathological evaluation. Therapeutic ultrasound energy was delivered circumferentially by an intravascular catheter maneuvered into the renal arteries. Fluoroscopic imaging was conducted pre-and post-ultrasound treatment. Animals were recovered and euthanized up to 30 hours post procedure, followed by necropsy and tissue sample collection. Histopathological examination showed evidence of extensive damage to renal nerves, characterized by nuclear pyknosis, hyalinization of stroma and multifocal hemorrhages, with little or no damage to renal arteries. This study demonstrates the feasibility of intravascular ultrasound as a minimally invasive renal denervation technique. Further studies are necessary to evaluate the long-term safety and efficacy of this technique and its related clinical significance.

Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation.

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Stiermaier, Thomas; Okon, Thomas; Fengler, Karl; Mueller, Ulrike; Hoellriegel, Robert; Schuler, Gerhard; Desch, Steffen; Lurz, Philipp

2016-06-12

Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients. A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (pmeasures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04. Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

Radiofrequency thermal ablation of malignant hepatic tumors: post-ablation syndrome

International Nuclear Information System (INIS)

Choi, Jung Bin; Rhim, Hyunchul; Kim, Yongsoo; Koh, Byung Hee; Cho, On Koo; Seo, Heung Suk; Lee, Seung Ro

2000-01-01

To evaluate post-ablation syndrome after radiofrequency thermal ablation of malignant hepatic tumors. Forty-two patients with primary (n=3D29) or secondary (n=3D13) hepatic tumors underwent radiofrequency thermal ablation. A total of 65 nodules ranging in size from 1.1 to 5.0 (mean, 3.1) cm were treated percutaneously using a 50W RF generator with 15G expandable needle electrodes. We retrospectively evaluated the spectrum of post-ablation syndrome including pain, fever (≥3D 38 deg C), nausea, vomiting, right shoulder pain, and chest discomfort according to frequency, intensity and duration, and the findings were correlated with tumor location and number of ablations. We also evaluated changes in pre-/post-ablation serum aminotransferase (ALT/AST) and prothrombin time, and correlated these findings with the number of ablations. Post-ablation syndrome was noted in 29 of 42 patients (69.0%), and most symptoms improved with conservative treatment. The most important of these were abdominal plan (n=3D20, 47.6%), fever (n=3D8, 19.0%), and nausea (n=3D7, 16.7%), and four of 42 (9.5%) patients complained of severe pain. The abdominal pain lasted from 3 hours to 5.5 days (mean; 20.4 hours), the fever from 6 hours to 5 days (mean; 63.0 hours). And the nausea from 1 hours to 4 days (mean; 21.0 hours). Other symptoms were right shoulder pain (n=3D6, 14.3%), chest discomfort (n=3D3, 7.1%), and headache (n=3D3, 7.1%). Seventeen of 20 patients (85%) with abdominal pain had subcapsular tumor of the liver. There was significant correlation between pain, location of the tumor, and a number of ablations. After ablation, ALT/AST was elevated more than two-fold in 52.6%/73.7% of patients, respectively but there was no significant correlation with the number of ablation. Post-ablation syndrome is a frequent and tolerable post-procedural process after radiofrequency thermal ablation. The spectrum of this syndrome provides a useful guideline for the post-ablation management. (author)

Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones.

Science.gov (United States)

Browning, Kirsteen N; Fortna, Samuel R; Hajnal, Andras

2013-05-01

Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12-14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal

At the heart of morality lies neuro-visceral integration: lower cardiac vagal tone predicts utilitarian moral judgment

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Kappes, Andreas; Rho, Yeojin; Van Bavel, Jay J.

2016-01-01

To not harm others is widely considered the most basic element of human morality. The aversion to harm others can be either rooted in the outcomes of an action (utilitarianism) or reactions to the action itself (deontology). We speculated that the human moral judgments rely on the integration of neural computations of harm and visceral reactions. The present research examined whether utilitarian or deontological aspects of moral judgment are associated with cardiac vagal tone, a physiological proxy for neuro-visceral integration. We investigated the relationship between cardiac vagal tone and moral judgment by using a mix of moral dilemmas, mathematical modeling and psychophysiological measures. An index of bipolar deontology-utilitarianism was correlated with resting heart rate variability (HRV)—an index of cardiac vagal tone—such that more utilitarian judgments were associated with lower HRV. Follow-up analyses using process dissociation, which independently quantifies utilitarian and deontological moral inclinations, provided further evidence that utilitarian (but not deontological) judgments were associated with lower HRV. Our results suggest that the functional integration of neural and visceral systems during moral judgments can restrict outcome-based, utilitarian moral preferences. Implications for theories of moral judgment are discussed. PMID:27317926

EFFECT OF LIVER DENERVATION ON GLUCOSE-PRODUCTION DURING RUNNING IN GUINEA-PIGS

NARCIS (Netherlands)

WIERSMA, MML; VISSING, J; MIKINES, KJ; STEFFENS, AB; GALBO, H

Activity in sympathetic liver nerves has been proposed to be important for glucose production in exercising humans. However, liver denervation does not influence the exercise-induced increase in glucose production in the rat and dog. These species have a poor sympathetic liver innervation in

Electrical Stimulation of Denervated Rat Skeletal Muscle Retards Capillary and Muscle Loss in Early Stages of Disuse Atrophy

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Kouki Nakagawa

2017-01-01

Full Text Available The purpose of the present study is to investigate the effects of low-frequency electrical muscle stimulation (ES on the decrease in muscle mass, fiber size, capillary supply, and matrix metalloproteinase (MMP immunoreactivity in the early stages of denervation-induced limb disuse. Direct ES was performed on the tibialis anterior muscle following denervation in seven-week-old male rats. The rats were divided into the following groups: control (CON, denervation (DN, and denervation with direct ES (DN + ES. Direct ES was performed at an intensity of 16 mA and a frequency of 10 Hz for 30 min per day, six days a week, for one week. We performed immunohistochemical staining to determine the expression of dystrophin, CD34, and MMP-2 in transverse sections of TA muscles. The weight, myofiber cross-sectional area (FCSA, and capillary-to-fiber (C/F ratio of the tibialis anterior (TA muscle were significantly reduced in the DN group compared to the control and DN + ES groups. The MMP-2 positive area was significantly greater in DN and DN + ES groups compared to the control group. These findings suggest beneficial effects of direct ES in reducing muscle atrophy and capillary regression without increasing MMP-2 immunoreactivity in the early stages of DN-induced muscle disuse in rat hind limbs.

Electrical Stimulation of Denervated Rat Skeletal Muscle Retards Capillary and Muscle Loss in Early Stages of Disuse Atrophy

Science.gov (United States)

Nakagawa, Kouki; Hayao, Keishi; Yotani, Kengo; Ogita, Futoshi; Yamamoto, Noriaki; Onishi, Hideaki

2017-01-01

The purpose of the present study is to investigate the effects of low-frequency electrical muscle stimulation (ES) on the decrease in muscle mass, fiber size, capillary supply, and matrix metalloproteinase (MMP) immunoreactivity in the early stages of denervation-induced limb disuse. Direct ES was performed on the tibialis anterior muscle following denervation in seven-week-old male rats. The rats were divided into the following groups: control (CON), denervation (DN), and denervation with direct ES (DN + ES). Direct ES was performed at an intensity of 16 mA and a frequency of 10 Hz for 30 min per day, six days a week, for one week. We performed immunohistochemical staining to determine the expression of dystrophin, CD34, and MMP-2 in transverse sections of TA muscles. The weight, myofiber cross-sectional area (FCSA), and capillary-to-fiber (C/F) ratio of the tibialis anterior (TA) muscle were significantly reduced in the DN group compared to the control and DN + ES groups. The MMP-2 positive area was significantly greater in DN and DN + ES groups compared to the control group. These findings suggest beneficial effects of direct ES in reducing muscle atrophy and capillary regression without increasing MMP-2 immunoreactivity in the early stages of DN-induced muscle disuse in rat hind limbs. PMID:28497057

Optimum and stepped care standardised antihypertensive treatment with or without renal denervation for resistant hypertension (DENERHTN): a multicentre, open-label, randomised controlled trial.

Science.gov (United States)

Azizi, Michel; Sapoval, Marc; Gosse, Philippe; Monge, Matthieu; Bobrie, Guillaume; Delsart, Pascal; Midulla, Marco; Mounier-Véhier, Claire; Courand, Pierre-Yves; Lantelme, Pierre; Denolle, Thierry; Dourmap-Collas, Caroline; Trillaud, Hervé; Pereira, Helena; Plouin, Pierre-François; Chatellier, Gilles

2015-05-16

Conflicting blood pressure-lowering effects of catheter-based renal artery denervation have been reported in patients with resistant hypertension. We compared the ambulatory blood pressure-lowering efficacy and safety of radiofrequency-based renal denervation added to a standardised stepped-care antihypertensive treatment (SSAHT) with the same SSAHT alone in patients with resistant hypertension. The Renal Denervation for Hypertension (DENERHTN) trial was a prospective, open-label randomised controlled trial with blinded endpoint evaluation in patients with resistant hypertension, done in 15 French tertiary care centres specialised in hypertension management. Eligible patients aged 18-75 years received indapamide 1·5 mg, ramipril 10 mg (or irbesartan 300 mg), and amlodipine 10 mg daily for 4 weeks to confirm treatment resistance by ambulatory blood pressure monitoring before randomisation. Patients were then randomly assigned (1:1) to receive either renal denervation plus an SSAHT regimen (renal denervation group) or the same SSAHT alone (control group). The randomisation sequence was generated by computer, and stratified by centres. For SSAHT, after randomisation, spironolactone 25 mg per day, bisoprolol 10 mg per day, prazosin 5 mg per day, and rilmenidine 1 mg per day were sequentially added from months two to five in both groups if home blood pressure was more than or equal to 135/85 mm Hg. The primary endpoint was the mean change in daytime systolic blood pressure from baseline to 6 months as assessed by ambulatory blood pressure monitoring. The primary endpoint was analysed blindly. The safety outcomes were the incidence of acute adverse events of the renal denervation procedure and the change in estimated glomerular filtration rate from baseline to 6 months. This trial is registered with ClinicalTrials.gov, number NCT01570777. Between May 22, 2012, and Oct 14, 2013, 1416 patients were screened for eligibility, 106 of those were randomly assigned to treatment

Critical Airway Compromise due to a Massive Vagal Schwannoma

LENUS (Irish Health Repository)

McDermott, AM

2016-05-01

We describe the case of a 37-year-old man with a slowly enlarging neck lump and compressive symptoms. He presented to a separate institution 10 years prior where an observational approach was advocated. Following preoperative investigations and embolization, an 11cm vagal schwannoma was excised and vagus nerve was sacrificed. Although conservative management is appropriate for a select patient population, surgical excision is treatment of choice for cervical neurogenic tumours and paraganglionomas and must be considered in young patients or rapidly expanding tumours to avoid compressive symptoms, as in this case.

The Effect of Patellar Denervation by Circumpatellar Electrocautery on Anterior Knee Pain Following Total Knee Replacement – An Experimental Study

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Balaji Zacharia

2017-07-01

Full Text Available ABSTRACT OBJECTIVES Anterior knee pain is a common problem in patients who have undergone TKR which causes dissatisfaction among them. There are Various methods for prevention of anterior knee pain following TKR .The  objective of this study is to determine the  effect of circumpatellar electrocautery on anterior knee pain following TKR and to compare the results with that of those patients who have undergone TKR without circumpatellar denervation. METHODS This is a cohort study conducted in Dept. of Orthopedics, Govt. Medical College, Kozhikode,kerala, 2014. Total sample size was 90.out of which 2 patients died during the study period. We lost follow up of 7 patients.  Among the remaining 81 patients 42 had undergone TKR with circumpatellar denervation using electocautery and 39 without circumpatellar denervation. They were kept under follow up. Patients were followed up postoperatively at 1 month, 3 months, 6 months and at one year. At all postoperative visits, a clinical score was determined using the Knee Society score and the clinical anterior knee pain rating system described by Waters and Bentley RESULTS There is no statistically significant difference in AKP score between both groups.There is a statistically significant difference in the knee society score at 1st month(p value <.001.  But there is no difference on further follow up visits . CONCLUSION There is no statistically significant difference between final outcome of patients who underwent patella denervation using circumpatellar electrocauterisation and those without denervation  with respect to anterior knee pain among patients who have undergone TKR.

Differential Activation of Medullary Vagal Nuclei Caused by Stimulation of Different Esophageal Mechanoreceptors

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Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

2010-01-01

Esophageal mechanorecptors, i.e. muscular slowly adapting tension receptors and mucosal rapidly adapting touch receptors, mediate different sets of reflexes. The aim of this study was to determine the medullary vagal nuclei involved in the reflex responses to activation of these receptors. Thirty-three cats were anesthetized with alpha-chloralose and the esophagus was stimulated by slow balloon or rapid air distension. The physiological effects of the stimuli (N=4) were identified by recording responses from the pharyngeal, laryngeal, and hyoid muscles, esophagus, and the lower esophageal sphincter (LES). The effects on the medullary vagal nuclei of the stimuli: slow distension (N=10), rapid distension (N=9), and in control animals (N=10) were identified using the immunohistochemical analysis of c-fos. The experimental groups were stimulated 3 times per minute for 3 hours. After the experiment, the brains were removed and processed for c-fos immunoreactivity or thioinin. We found that slow balloon distension activated the esophago-UES contractile reflex and esophago LES relaxation response, and rapid air injection activated the belch and its component reflexes. Slow balloon distension activated the NTSce, NTSdl, NTSvl, DMNc, DMNr and NAr; and rapid air injection primarily activated AP, NTScd, NTSim, NTSis, NTSdm, NTSvl, NAc and NAr. We concluded that different sets of medullary vagal nuclei mediate different reflexes of the esophagus activated from different sets of mechanoreceptors. The NTScd is the primary NTS subnucleus mediating reflexes from the mucosal rapidly adapting touch receptors, and the NTSce is the primary NTS subnucleus mediating reflexes from the muscular slowly adapting tension receptors. The AP may be involved in mediation of belching. PMID:20971087

In vitro receptor autoradiography reveals angiotensin IL (ANG II) binding associated with sensory and motor components of the vagus

International Nuclear Information System (INIS)

Diz, D.I.; Barnes, K.L.; Ferrario, C.M.

1986-01-01

Specific, high affinity Ang II binding in the dog's dorsal medulla is concentrated in the area postrema, nucleus tractus solitarii (nTS) and dorsal motor nucleus of the vagus (dmnX). More recently Ang II binding sites were observed where bundles of vagal afferent fibers enter the dorsal medulla 6 mm rostral to obex and in the nodose ganglia and peripheral vagal nerves. Since Ang II binding in the nTS and dmnX overlies the distribution of vagal afferent fibers and efferent neurons, the effects of nodose ganglionectomy and cervical vagotomy on Ang II binding in the dorsal medulla were studied in rats and dogs using autoradiography after incubation of 14 μm coronal sections with 0.4 nM 125 I-Ang II. Nonspecific binding was determined in the presence of 1 μm unlabeled Ang II. Two weeks after unilateral nodose ganglionectomy Ang II binding sites were absent ipsilaterally in the region where vagal afferent fibers enter the dorsal medulla. In the nTS and dmnX, binding near obex was reduced, while more rostrally these nuclei were almost completely devoid of Ang II binding on the denervated side. After cervical vagotomy, the loss of binding was restricted to the ipsilateral dmnX. These data are the first to reveal that Ang II binding in the dorsal medulla requires an intact vagal system

Avaliando a atividade vagal cardíaca na eletrocardiografia convencional Evaluating cardiac vagal activity on a conventional electrocardiogram

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Flávia P. Teixeira

2007-04-01

Full Text Available OBJETIVO: Determinar a viabilidade da utilização de traçado convencional de eletrocardiografia (ECG para avaliação da atividade vagal cardíaca (AVC. MÉTODOS: Foram analisados, retrospectivamente, 1.395 indivíduos (995 homens, na faixa de idade de 46 + 17,2 anos (média ± desvio padrão, com traçados de ECG convencional para medida do Delta RR, que representa a diferença, em ms, entre o maior e o menor intervalo RR, e com resultados da avaliação autonômica parassimpática, o teste de exercício de quatro segundos (T4s, que quantifica a AVC por meio do índice vagal cardíaco (IVC. Foram obtidas curvas ROC para determinar os valores de Delta RR com melhor relação entre sensibilidade e especificidade para os pontos de corte de baixa e alta AVC, respectivamente, de 1,20 e 1,95. RESULTADOS: Os valores de delta RR correlacionaram-se significativamente com os de IVC (r = 0,40; p 120 ms como os melhores pontos de corte para baixa e alta AVC, com sensibilidade de 75% e 57%, especificidade de 62% e 79% e áreas das curvas ROC de 0,76 e 0,74, respectivamente. CONCLUSÃO: A medida visual do delta RR em um traçado de ECG parece ser válida para a avaliação clínica preliminar e rápida da AVC, podendo ser útil em consultórios, emergências ou situações nas quais o uso de métodos mais sofisticados de avaliação autonômica não seja viável, oportuno ou conveniente.OBJECTIVE: To determine the viability of using a conventional electrocardiogram (ECG tracing for assessment of CVA. METHODS: We retrospectively analyzed 1395 individuals (995 males, aged 46 ± 17.2 years (mean ± standard deviation with conventional ECG tracings to measure the delta RR (which represents the difference in milliseconds (ms between the greatest and smallest RR interval and results of a second autonomic parasympathetic evaluation, the 4-second exercise test (T4s, that quantifies CVA by the cardiac vagal index (CVI. ROC curves were obtained to determine the

Therapeutic effects of selective atrioventricular node vagal stimulation in atrial fibrillation and heart failure.

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Zhang, Youhua; Popović, Zoran B; Kusunose, Kenya; Mazgalev, Todor N

2013-01-01

Atrial fibrillation (AF) and heart failure (HF) frequently coexist. We have previously demonstrated that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during AF. Due to withdrawal of vagal activity in HF, the therapeutic effects of AVN-VS may be compromised in the combined condition of AF and HF. Accordingly, this study was designed to evaluate the therapeutic effects of AVN-VS to control ventricular rate in AF and HF. A combined model of AF and HF was created by implanting a dual chamber pacemaker in 24 dogs. A newly designed bipolar electrode was inserted into the ganglionic AVN fat pad and connected to a nerve stimulator for delivering AVN-VS. In all dogs, HF was induced by high rate ventricular pacing at 220 bpm for 4 weeks. AF was then induced and maintained by rapid atrial pacing at 600 bpm after discontinuation of ventricular pacing. These HF + AF dogs were randomized into control (n = 9) and AVN-VS (n = 15) groups. In the latter group, vagal stimulation (310 μs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. Compared with the control, AVN-VS had a consistent effect on ventricular rate slowing (by >50 bpm, all P AVN-VS was well tolerated by the treated animals. AVN-VS achieved consistent rate slowing, which was associated with improved ventricular function in a canine AF and HF model. Thus, AVN-VS may be a novel, effective therapeutic option in the combined condition of AF and HF. © 2012 Wiley Periodicals, Inc.

Comparison of wet radiofrequency ablation with dry radiofrequency ablation and radiofrequency ablation using hypertonic saline preinjection: ex vivo bovine liver

International Nuclear Information System (INIS)

Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Lee, Jae Young; Park, Hee Sun; Hur, Hurn; Choi, Byung Ihn; Shin, Kyung Sook

2004-01-01

We wished to compare the in-vitro efficiency of wet radiofrequency (RF) ablation with the efficiency of dry RF ablation and RF ablation with preinjection of NaCl solutions using excised bovine liver. Radiofrequency was applied to excised bovine livers in a monopolar mode for 10 minutes using a 200 W generator and a perfused-cooled electrode with or without injection or slow infusion of NaCl solutions. After placing the perfused-cooled electrode in the explanted liver, 50 ablation zones were created with five different regimens: group A; standard dry RF ablation, group B; RF ablation with 11 mL of 5% NaCl solution preinjection, group C; RF ablation with infusion of 11 mL of 5% NaCl solution at a rate of 1 mL/min, group D; RFA with 6 mL of 36% NaCl solution preinjection, group E; RF ablation with infusion of 6 mL of 36% NaCl solution at a rate of 0.5 mL/min. In groups C and E, infusion of the NaCl solutions was started 1 min before RF ablation and then maintained during RF ablation (wet RF ablation). During RF ablation, we measured the tissue temperature at 15 mm from the electrode. The dimensions of the ablation zones and changes in impedance, current and liver temperature during RF ablation were then compared between the groups. With injection or infusion of NaCl solutions, the mean initial tissue impedance prior to RF ablation was significantly less in groups B, C, D, and E (43-75 Ω) than for group A (80 Ω) (ρ 3 in group A; 12.4 ± 3.8 cm 3 in group B; 80.9 ± 9.9 cm 3 in group C; 45.3 ± 11.3 cm 3 in group D and 81.6 ± 8.6 cm 3 in group E. The tissue temperature measured at 15 mm from the electrode was higher in groups C, D and E than other groups (ρ < 0.05): 53 ± 12 .deg. C in group A, 42 ± 2 .deg. C in group B, 93 ± 8 .deg. C in group C; 79 ± 12 .deg. C in group D and 83 ± 8 .deg.C in group E. Wet RF ablation with 5% or 36% NaCl solutions shows better efficiency in creating a large ablation zone than does dry RF ablation or RF ablation with

Neurogenic myopathies and imaging of muscle denervation; Neurogene Myopathien und Bildgebung der Muskeldenervation

Energy Technology Data Exchange (ETDEWEB)

Wolf, M. [Universitaetsklinikum Heidelberg, Abteilung fuer Neuroradiologie, Heidelberg (Germany); Wolf, C. [Reha-Zentrum Gernsbach, Neurologie, Gernsbach (Germany); Weber, M.A. [Universitaetsklinikum Heidelberg, Abteilung fuer Diagnostische und Interventionelle Radiologie, Heidelberg (Germany)

2017-12-15

Neurogenic myopathies are primary diseases of the nervous system, which secondarily result in denervation of the target musculature. The spectrum of potential causes is manifold ranging from acute traumatic injuries and chronic compression to neurodegenerative, inflammatory, metabolic and neoplastic processes. The medical history, clinical neurological examination, and electrophysiological tests including electromyography and nerve conduction studies are crucial in diagnosing neuropathic myopathies. Electromyography is the gold standard for diagnosing muscle denervation. Additional imaging methods and magnetic resonance imaging (MRI) in particular, are capable of contributing valuable information. The MRI examination of denervated musculature shows edema, an increase in the apparent diffusion coefficient (ADC) and hyperperfusion. Chronic denervation results in fatty degeneration and atrophy of affected muscles, which are also detectable by MRI. Although the MRI findings in muscle denervation are relatively unspecific, they show a high sensitivity, comparable to electromyography. Dedicated MR neurography may often visualize the underlying lesion(s) of the innervating nerve(s). Besides high sensitivity, comparable to electromyography, MRI is capable of evaluating muscles which are inaccessible for needle electromyography. Due to its non-invasive character, MRI is ideal for follow-up examinations. The use of MRI is often a meaningful addition to the diagnostics of neurogenic myopathies. The extent and distribution pattern of muscular alterations often provide information on the localization of the causative nerve damage. A correct diagnosis or at least a narrowing down of possible differential diagnoses can often be achieved using MRI. (orig.) [German] Neurogene Myopathien sind Erkrankungen des Nervensystems, die sekundaer zur Denervierung der Zielmuskulatur fuehren. Das Spektrum potenzieller Ursachen ist vielfaeltig und umfasst akute traumatische Verletzungen

Redo renal denervation using a multi-electrode radiofrequency system in patients with persistent therapy-resistant hypertension.

Science.gov (United States)

Daemen, J; Feyz, L; Van Zandvoort, L; Van Mieghem, N M

2017-06-01

Renal sympathetic denervation has been studied as a potential therapeutic option for patients with therapy-resistant hypertension; however, a significant proportion of patients do not show a significant reduction in blood pressure and are classified as non-responders. The objective of the present study was to assess whether a redo renal denervation procedure increases response rates. We present a case series of three consecutive renal denervation non-responders treated with the multi-electrode radiofrequency St. Jude EnligHTN catheter after an average of 22 months. Patients were followed for 6 months. Mean age was 66 years and two patients were male. Patients were previously treated using either ReCor's Paradise system, the Vessix V2 system or the Covidien OneShot system. Mean office blood pressure one year after the initial procedure was 187/102 mm Hg with a mean 24 h ambulatory blood pressure of 166/102 mm Hg. All patients underwent a successful redo procedure using the EnligHTN system because of persistent therapy-resistant hypertension. At 6 months a significant drop in both office and ambulatory blood pressure of -27/-6 mm Hg and -15/-13 mm Hg, respectively, was observed. No significant renal artery stenosis was observed at 6 months. In patients with therapy-resistant hypertension who do not respond to an initial renal denervation procedure, a redo procedure using the St. Jude EnligHTN system may help to significantly improve blood pressure control.

Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

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Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

2016-12-01

Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter 4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more proximal segments. These findings warrant further evaluation of the spatial innervation patterns of the renal artery in order to understand how it may enhance catheter-based renal arterial denervation procedural strategy and outcomes. The SYMPLICITY HTN-3 study dealt a blow to the idea of the catheter-based renal arterial sympathetic denervation. We investigated the location and patterns of periarterial renal nerves in cadaveric human renal arteries. To quantify the density of the

At the heart of morality lies neuro-visceral integration: lower cardiac vagal tone predicts utilitarian moral judgment.

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Park, Gewnhi; Kappes, Andreas; Rho, Yeojin; Van Bavel, Jay J

2016-10-01

To not harm others is widely considered the most basic element of human morality. The aversion to harm others can be either rooted in the outcomes of an action (utilitarianism) or reactions to the action itself (deontology). We speculated that the human moral judgments rely on the integration of neural computations of harm and visceral reactions. The present research examined whether utilitarian or deontological aspects of moral judgment are associated with cardiac vagal tone, a physiological proxy for neuro-visceral integration. We investigated the relationship between cardiac vagal tone and moral judgment by using a mix of moral dilemmas, mathematical modeling and psychophysiological measures. An index of bipolar deontology-utilitarianism was correlated with resting heart rate variability (HRV)-an index of cardiac vagal tone-such that more utilitarian judgments were associated with lower HRV. Follow-up analyses using process dissociation, which independently quantifies utilitarian and deontological moral inclinations, provided further evidence that utilitarian (but not deontological) judgments were associated with lower HRV. Our results suggest that the functional integration of neural and visceral systems during moral judgments can restrict outcome-based, utilitarian moral preferences. Implications for theories of moral judgment are discussed. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Distinct projection targets define subpopulations of mouse brainstem vagal neurons that express the autism-associated MET receptor tyrosine kinase.

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Kamitakahara, Anna; Wu, Hsiao-Huei; Levitt, Pat

2017-12-15

Detailed anatomical tracing and mapping of the viscerotopic organization of the vagal motor nuclei has provided insight into autonomic function in health and disease. To further define specific cellular identities, we paired information based on visceral connectivity with a cell-type specific marker of a subpopulation of neurons in the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (nAmb) that express the autism-associated MET receptor tyrosine kinase. As gastrointestinal disturbances are common in children with autism spectrum disorder (ASD), we sought to define the relationship between MET-expressing (MET+) neurons in the DMV and nAmb, and the gastrointestinal tract. Using wholemount tissue staining and clearing, or retrograde tracing in a MET EGFP transgenic mouse, we identify three novel subpopulations of EGFP+ vagal brainstem neurons: (a) EGFP+ neurons in the nAmb projecting to the esophagus or laryngeal muscles, (b) EGFP+ neurons in the medial DMV projecting to the stomach, and (b) EGFP+ neurons in the lateral DMV projecting to the cecum and/or proximal colon. Expression of the MET ligand, hepatocyte growth factor (HGF), by tissues innervated by vagal motor neurons during fetal development reveal potential sites of HGF-MET interaction. Furthermore, similar cellular expression patterns of MET in the brainstem of both the mouse and nonhuman primate suggests that MET expression at these sites is evolutionarily conserved. Together, the data suggest that MET+ neurons in the brainstem vagal motor nuclei are anatomically positioned to regulate distinct portions of the gastrointestinal tract, with implications for the pathophysiology of gastrointestinal comorbidities of ASD. © 2017 Wiley Periodicals, Inc.

The role of cardiac vagal tone and inhibitory control in pre-schoolers' listening comprehension.

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Scrimin, Sara; Patron, Elisabetta; Florit, Elena; Palomba, Daniela; Mason, Lucia

2017-12-01

This study investigated the role of basal cardiac activity and inhibitory control at the beginning of the school year in predicting oral comprehension at the end of the year in pre-schoolers. Forty-three, 4-year-olds participated in the study. At the beginning of the school year children's electrocardiogram at rest was registered followed by the assessment of inhibitory control as well as verbal working memory and verbal ability. At the end of the year all children were administered a listening comprehension ability measure. A stepwise regression showed a significant effect of basal cardiac vagal tone in predicting listening comprehension together with inhibitory control and verbal ability. These results are among the first to show the predictive role of basal cardiac vagal tone and inhibitory control in pre-schoolers' oral text comprehension, and offer new insight into the association between autonomic regulation of the heart, inhibitory control, and cognitive activity at a young age. © 2017 Wiley Periodicals, Inc.

An experimental study of simultaneous ablation with dual probes in radiofrequency thermal ablation

International Nuclear Information System (INIS)

Jang, Il Soo; Rhim, Hyun Chul; Koh, Byung Hee; Cho, On Koo; Seo, Heung Suk; Kim, Yong Soo; Kim, Young Sun; Heo, Jeong Nam

2003-01-01

To determine the differences between sequential ablation with a single probe and simultaneous ablation with dual probes. Using two 14-gauge expandable probes (nine internal prongs with 4-cm deployment), radiofrequency was applied sequentially (n=8) or simultaneously (n=8) to ten ex-vivo cow livers. Before starting ablation, two RF probes with an inter-probe space of 2 cm (n=8) or 3 cm (n=8) were inserted. In the sequential group, switching the connecting cable to an RF generator permitted ablation with the second probe just after ablation with the first probe had finished. In the simultaneous group, single ablation was performed only after connecting the shafts of both RF probes using a connection device. Each ablation lasted 7 minutes at a target temperature of 105-110 .deg. C. The size and shape of the ablated area, and total ablation time were then compared between the two groups. With 2-cm spacing, the group, mean length and overlapping width of ablated lesions were, respectively, 5.20 and 5.05 cm in the sequential group (n=4), and 5.81 and 5.65 cm in the simultaneous group (n=4). With 3-cm spacing, the corresponding figures were 4.99 and 5.60 cm in the sequential group (n=4), and 6.04 and 6.78 cm in the simultaneous group (n=4). With 2-cm spacing, the mean depth of the proximal waist was 0.58 cm in the sequential (group and 0.28 cm in the simultaneous group, while with 3-cm spacing, the corresponding figures were 1.65 and 1.48 cm. In neither group was there a distal waist. Mean total ablation time was 23.4 minutes in the sequential group and 14 minutes in the simultaneous group. In terms of ablation size and ablation time, simultaneous radiofrequency ablation with dual probes is superior to sequential ablation with a single probe. A simultaneous approach will enable an operator to overcome difficulty in probe repositioning during overlapping ablation, resulting in complete ablation with a successful safety margin

The Heart´s rhythm 'n' blues: Sex differences in circadian variation patterns of vagal activity vary by depressive symptoms in predominantly healthy employees.

Science.gov (United States)

Jarczok, Marc N; Aguilar-Raab, Corina; Koenig, Julian; Kaess, Michael; Borniger, Jeremy C; Nelson, Randy J; Hall, Martica; Ditzen, Beate; Thayer, Julian F; Fischer, Joachim E

2018-03-15

Successful regulation of emotional states is positively associated to mental health, while difficulties in regulating emotions are negatively associated to overall mental health and in particular associated with anxiety or depression symptoms. A key structure associated to socio-emotional regulatory processes is the central autonomic network. Activity in this structure is associated to vagal activity can be indexed noninvasively and simply by measures of peripheral cardiac autonomic modulations such as heart rate variability. Vagal activity exhibits a circadian variation pattern, with a maximum during nighttime. Depression is known to affect chronobiology. Also, depressive symptoms are known to be associated with decreased resting state vagal activity, but studies investigating the association between circadian variation pattern of vagal activity and depressive symptoms are scarce. We aim to examine these patterns in association to symptom severity of depression using chronobiologic methods. Data from the Manheim Industrial Cohort Studies (MICS) were used. A total of 3,030 predominantly healthy working adults underwent, among others, ambulatory 24-h hear rate-recordings, detailed health examination and online questionnaires and were available for this analysis. The root mean sum of successive differences (RMSSD) was used as an indicator of vagally mediated heart rate variability. Three individual-level cosine function parameters (MESOR, amplitude, acrophase) were estimated to quantify circadian variation pattern. Multivariate linear regression models including important covariates such as age, sex, and lifestyle factors as well as an interaction effect of sex with depressive symptoms were used to estimate the association of circadian variation pattern of vagal activity with depressive symptoms simultaneously. The analysis sample consisted of 20.2% females and an average age 41 with standard deviation of 11 years. Nonparametric bivariate analysis revealed

Renal denervation--hypes and hopes.

Science.gov (United States)

Lewek, Joanna; Kaczmarek, Krzysztof; Pokushalov, Evgeniy; Romanov, Alexandr; Cygankiewicz, Iwona; Ptaszynski, Pawel

2015-06-01

Catheter-based renal denervation (RDN) is a novel invasive approach in the treatment of resistant hypertension. It is considered a minimally invasive and safe procedure which, as shown by initial experimental and clinical trials, is able not only to reduce blood pressure but also to modify its risk factors by modulation of autonomic nervous system. Recently published results of a randomized Symplicity HTN-3 trial, which failed to demonstrate RDN-induced reduction of blood pressure at six months, decreased the initial enthusiasm regarding RDN and raised a question about real efficacy of this procedure. Nevertheless, still there are some other conditions characterized by increased sympathetic tone such as heart failure, atrial fibrillation, or ventricular arrhythmias that may benefit from RDN. Furthermore, novel therapeutical approach toward RDN using adapted electrophysiological or new specially designed electrodes may improve effectiveness of RDN procedure. © 2015 John Wiley & Sons Ltd.

Skeletal muscles of hibernating brown bears are unusually resistant to effects of denervation.

Science.gov (United States)

Lin, David C; Hershey, John D; Mattoon, John S; Robbins, Charles T

2012-06-15

Hibernating bears retain most of their skeletal muscle strength despite drastically reduced weight-bearing activity. Regular neural activation of muscles is a potential mechanism by which muscle atrophy could be limited. However, both mechanical loading and neural activity are usually necessary to maintain muscle size. An alternative mechanism is that the signaling pathways related to the regulation of muscle size could be altered so that neither mechanical nor neural inputs are needed for retaining strength. More specifically, we hypothesized that muscles in hibernating bears are resistant to a severe reduction in neural activation. To test this hypothesis, we unilaterally transected the common peroneal nerve, which innervates ankle flexor muscles, in hibernating and summer-active brown bears (Ursus arctos). In hibernating bears, the long digital extensor (LDE) and cranial tibial (CT) musculotendon masses on the denervated side decreased after 11 weeks post-surgery by 18 ± 11 and 25 ± 10%, respectively, compared with those in the intact side. In contrast, decreases in musculotendon masses of summer-active bears after denervation were 61 ± 4 and 58 ± 5% in the LDE and CT, respectively, and significantly different from those of hibernating bears. The decrease due to denervation in summer-active bears was comparable to that occurring in other mammals. Whole-muscle cross-sectional areas (CSAs) measured from ultrasound images and myofiber CSAs measured from biopsies decreased similarly to musculotendon mass. Thus, hibernating bears alter skeletal muscle catabolic pathways regulated by neural activity, and exploration of these pathways may offer potential solutions for disuse atrophy of muscles.

Ablation mass features in multi-pulses femtosecond laser ablate molybdenum target

Science.gov (United States)

Zhao, Dongye; Gierse, Niels; Wegner, Julian; Pretzler, Georg; Oelmann, Jannis; Brezinsek, Sebastijan; Liang, Yunfeng; Neubauer, Olaf; Rasinski, Marcin; Linsmeier, Christian; Ding, Hongbin

2018-03-01

In this study, the ablation mass features related to reflectivity of bulk Molybdenum (Mo) were investigated by a Ti: Sa 6 fs laser pulse at central wavelength 790 nm. The ablated mass removal was determined using Confocal Microscopy (CM) technique. The surface reflectivity was calibrated and measured by a Lambda 950 spectrophotometer as well as a CCD camera during laser ablation. The ablation mass loss per pulse increase with the increasing of laser shots, meanwhile the surface reflectivity decrease. The multi-pulses (100 shots) ablation threshold of Mo was determined to be 0.15 J/cm2. The incubation coefficient was estimated as 0.835. The reflectivity change of the Mo target surface following multi-pulses laser ablation were studied as a function of laser ablation shots at various laser fluences from 1.07 J/cm2 to 36.23 J/cm2. The results of measured reflectivity indicate that surface reflectivity of Mo target has a significant decline in the first 3-laser pulses at the various fluences. These results are important for developing a quantitative analysis model for laser induced ablation and laser induced breakdown spectroscopy for the first wall diagnosis of EAST tokamak.

Daith Piercing in a Case of Chronic Migraine: A Possible Vagal Modulation

Directory of Open Access Journals (Sweden)

Angelo Cascio Rizzo

2017-11-01

Full Text Available Daith piercing is an ear piercing located at the crus of the helix, bilaterally. It is getting great consent on social media as alternative treatment in chronic migraine. No data about its efficacy and action are available in scientific literature so far. We present the case of a 54-year-old male patient suffering from refractory chronic migraine with medication-overuse, who substantially improved after bilateral ear daith piercing. His migraine was refractory to symptomatic as well as prophylactic therapies. He used to treat headaches with up to five symptomatic drugs per attack and had attempted several pharmacological preventive therapies, including Onabotulinumtoxin A. He also underwent detoxification treatments with intravenous steroids and diazepam, without durable benefit. At the time of daith piercing, the headache-related disability measures showed a HIT-6 score of 64, a MIDAS-score of 70, and a 11-point Box scale of 5. On his own free will, he decided to get a “daith piercing.” After that, he experienced a reduction of migraine attacks, which became very rare, and infrequent, less disabling episodes of tension-type headache (HIT-6 score of 56; MIDAS score of 27, 11-point Box scale of 3. Painkiller assumption has much decreased: he takes only one tablet of indomethacin 50 mg to treat tensive headaches, about four times per month. Beyond a placebo effect, we can speculate a vagal modulation as the action mechanism of daith piercing: a nociceptive sensory stimulus applied to trigeminal and vagal areas of the ear can activate ear vagal afferents, which can modulate pain pathways by means of projections to the caudal trigeminal nucleus, to the locus coeruleus and to the nucleus raphe magnus. Currently, daith piercing cannot be recommended as migraine treatment because of the lack of scientific evidence, the unquantified rate of failure and the associated risks with insertion. However, given the increasing but anecdotal evidence, we

Renal denervation for the management of resistant hypertension

Science.gov (United States)

Patel, Hitesh C; Hayward, Carl; Vassiliou, Vassilis; Patel, Ketna; Howard, James P; Di Mario, Carlo

2015-01-01

Renal sympathetic denervation (RSD) as a therapy for patients with resistant hypertension has attracted great interest. The majority of studies in this field have demonstrated impressive reductions in blood pressure (BP). However, these trials were not randomized or sham-controlled and hence, the findings may have been overinflated due to trial biases. SYMPLICITY HTN-3 was the first randomized controlled trial to use a blinded sham-control and ambulatory BP monitoring. A surprise to many was that this study was neutral. Possible reasons for this neutrality include the fact that RSD may not be effective at lowering BP in man, RSD was not performed adequately due to limited operator experience, patients’ adherence with their anti-hypertensive drugs may have changed during the trial period, and perhaps the intervention only works in certain subgroups that are yet to be identified. Future studies seeking to demonstrate efficacy of RSD should be designed as randomized blinded sham-controlled trials. The efficacy of RSD is in doubt, but many feel that its safety has been established through the thousands of patients in whom the procedure has been performed. Over 90% of these data, however, are for the Symplicity™ system and rarely extend beyond 12 months of follow-up. Long-term safety cannot be assumed with RSD and nor should it be assumed that if one catheter system is safe then all are. We hope that in the near future, with the benefit of well-designed clinical trials, the role of renal denervation in the management of hypertension will be established. PMID:26672761

The effect of vagal nerve blockade using electrical impulses on glucose metabolism in nondiabetic subjects

Directory of Open Access Journals (Sweden)

Sathananthan M

2014-07-01

Full Text Available Matheni Sathananthan,1 Sayeed Ikramuddin,2 James M Swain,3,6 Meera Shah,1 Francesca Piccinini,4 Chiara Dalla Man,4 Claudio Cobelli,4 Robert A Rizza,1 Michael Camilleri,5 Adrian Vella1 1Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA; 2Division of General Surgery, University of Minnesota, Minneapolis, MN, USA; 3Division of General Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA; 4Department of Information Engineering, University of Padua, Padua, Italy; 5Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA; 6Scottsdale Healthcare Bariatric Center, Scottsdale, AZ, USA Purpose: Vagal interruption causes weight loss in humans and decreases endogenous glucose production in animals. However, it is unknown if this is due to a direct effect on glucose metabolism. We sought to determine if vagal blockade using electrical impulses alters glucose metabolism in humans. Patients and methods: We utilized a randomized, cross-over study design where participants were studied after 2 weeks of activation or inactivation of vagal nerve blockade (VNB. Seven obese subjects with impaired fasting glucose previously enrolled in a long-term study to examine the effect of VNB on weight took part. We used a standardized triple-tracer mixed meal to enable measurement of the rate of meal appearance, endogenous glucose production, and glucose disappearance. The 550 kcal meal was also labeled with 111In-diethylene triamine pentaacetic acid (DTPA to measure gastrointestinal transit. Insulin action and ß-cell responsivity indices were estimated using the minimal model. Results: Integrated glucose, insulin, and glucagon concentrations did not differ between study days. This was also reflected in a lack of effect on β-cell responsivity and insulin action. Furthermore, fasting and postprandial endogenous glucose production, integrated meal appearance, and glucose

Lipid-rich enteral nutrition regulates mucosal mast cell activation via the vagal anti-inflammatory reflex

NARCIS (Netherlands)

de Haan, Jacco J.; Hadfoune, M.'hamed; Lubbers, Tim; Hodin, Caroline; Lenaerts, Kaatje; Ito, Akihiko; Verbaeys, Isabelle; Skynner, Michael J.; Cailotto, Cathy; van der Vliet, Jan; de Jonge, Wouter J.; Greve, Jan-Willem M.; Buurman, Wim A.

2013-01-01

Nutritional stimulation of the cholecystokinin-1 receptor (CCK-1R) and nicotinic acetylcholine receptor (nAChR)-mediated vagal reflex was shown to reduce inflammation and preserve intestinal integrity. Mast cells are important early effectors of the innate immune response; therefore modulation of

Transcatheter renal denervation for the treatment of resistant arterial hypertension: the Swiss expert consensus.

Science.gov (United States)

Wuerzner, Gregoire; Muller, Olivier; Erne, Paul; Cook, Stéphane; Sudano, Isabella; Lüscher, Thomas F; Noll, Georg; Kaufmann, Urs; Rickli, Hans; Waeber, Bernard; Kaiser, Christophe; Sticherling, Christian; Pechère-Bertschi, Antoinette; Baumgartner, Iris; Jacob, Augustinus L; Burnier, Michel; Qanadli, Salah D

2014-03-20

Transcatheter (or percutaneous) renal denervation is a novel technique developed for the treatment of resistant hypertension. So far, only one randomised controlled trial has been published, which has shown a reduction of office blood pressure. The Swiss Society of Hypertension, the Swiss Society of Cardiology, The Swiss Society of Angiology and the Swiss Society of Interventional Radiology decided to establish recommendations to practicing physicians and specialists for good clinical practice. The eligibility of patients for transcatheter renal denervation needs (1.) confirmation of truly resistant hypertension, (2.) exclusion of secondary forms of hypertension, (3.) a multidisciplinary decision confirming the eligibility, (4.) facilities that guarantee procedural safety and (5.) a long-term follow-up of the patients, if possible in cooperation with a hypertension specialist. These steps are essential until long-term data on safety and efficacy are available.

Plasticity of the transverse tubules following denervation and subsequent reinnervation in rat slow and fast muscle fibres.

Science.gov (United States)

Takekura, Hiroaki; Tamaki, Hiroyuki; Nishizawa, Tomie; Kasuga, Norikatsu

2003-01-01

We have studied the effects of short term denervation followed by reinnervation on the ultrastructure of the membrane systems and on the content of and distribution of key proteins involved in calcium regulation of fast-twitch (FT) extensor digitorum longus (EDL) and slow-twitch (ST) soleus (SOL) muscle fibres. Ischiadic nerve freezing resulted in total lack of neuromuscular transmission for 3 days followed by a slow recovery, but no decline in twitch force elicited by direct stimulation. The latter measurements indicate no significant atrophy within this time frame. The membrane systems of skeletal muscle fibres were visualized using Ca92+)-K3Fe(CN)6-OsO4 techniques and observed using a high voltage electron microscope. [3H]nitrendipine binding was used to detect levels of dihydropyridine receptor (DHPR) expression. The Ca2+ pumping free sarcoplasmic reticulum domains were not affected by the denervation, but the Ca2+ release domains were dramatically increased, particularly in the FT-EDL muscle fibres. The increase is evidenced by a doubling up of the areas of contacts between SR and transverse (t-) tubules, so that in place of the normal triadic arrangement, pentadic and heptadic junctions, formed by multiple interacting layers of ST and t-tubules are seen. Frequency of pentads and heptads increases and declines in parallel to the denervation and reinnervation but with a delay. Immunofluorecence and electron microscopy observations show presence of DHPR and ryanodine receptor clusters at pentads and heptads junctions. A significant (P muscle fibres indicating that overexpression of DHPRs accompanies the build up extra junctional contacts. The results indicate that denervation reversibly affects the domains of the membrane systems involved in excitation-contraction coupling.

Sensory nerve cross-anastomosis and electrical muscle stimulation synergistically enhance functional recovery of chronically denervated muscle.

Science.gov (United States)

Willand, Michael P; Holmes, Michael; Bain, James R; de Bruin, Hubert; Fahnestock, Margaret

2014-11-01

Long-term muscle denervation leads to severe and irreversible atrophy coupled with loss of force and motor function. These factors contribute to poor functional recovery following delayed reinnervation. The authors' previous work demonstrated that temporarily suturing a sensory nerve to the distal motor stump (called sensory protection) significantly reduces muscle atrophy and improves function following reinnervation. The authors have also shown that 1 month of electrical stimulation of denervated muscle significantly improves function and reduces atrophy. In this study, the authors tested whether a combination of sensory protection and electrical stimulation would enhance functional recovery more than either treatment alone. Rat gastrocnemius muscles were denervated by cutting the tibial nerve. The peroneal nerve was then sutured to the distal tibial stump following 3 months of treatment (i.e., electrical stimulation, sensory protection, or both). Three months after peroneal repair, functional and histologic measurements were taken. All treatment groups had significantly higher muscle weight (pstimulation or sensory protection alone. The combined treatment also produced motor unit counts significantly greater than sensory protection alone (p<0.05). The combination treatment synergistically reduces atrophy and improves reinnervation and functional measures following delayed nerve repair, suggesting that these approaches work through different mechanisms. The authors' research supports the clinical use of both modalities together following peripheral nerve injury.

Duodenal activation of cAMP-dependent protein kinase induces vagal afferent firing and lowers glucose production in rats.

Science.gov (United States)

Rasmussen, Brittany A; Breen, Danna M; Luo, Ping; Cheung, Grace W C; Yang, Clair S; Sun, Biying; Kokorovic, Andrea; Rong, Weifang; Lam, Tony K T

2012-04-01

The duodenum senses nutrients to maintain energy and glucose homeostasis, but little is known about the signaling and neuronal mechanisms involved. We tested whether duodenal activation of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) is sufficient and necessary for cholecystokinin (CCK) signaling to trigger vagal afferent firing and regulate glucose production. In rats, we selectively activated duodenal PKA and evaluated changes in glucose kinetics during the pancreatic (basal insulin) pancreatic clamps and vagal afferent firing. The requirement of duodenal PKA signaling in glucose regulation was evaluated by inhibiting duodenal activation of PKA in the presence of infusion of the intraduodenal PKA agonist (Sp-cAMPS) or CCK1 receptor agonist (CCK-8). We also assessed the involvement of a neuronal network and the metabolic impact of duodenal PKA activation in rats placed on high-fat diets. Intraduodenal infusion of Sp-cAMPS activated duodenal PKA and lowered glucose production, in association with increased vagal afferent firing in control rats. The metabolic and neuronal effects of duodenal Sp-cAMPS were negated by coinfusion with either the PKA inhibitor H89 or Rp-CAMPS. The metabolic effect was also negated by coinfusion with tetracaine, molecular and pharmacologic inhibition of NR1-containing N-methyl-d-aspartate (NMDA) receptors within the dorsal vagal complex, or hepatic vagotomy in rats. Inhibition of duodenal PKA blocked the ability of duodenal CCK-8 to reduce glucose production in control rats, whereas duodenal Sp-cAMPS bypassed duodenal CCK resistance and activated duodenal PKA and lowered glucose production in rats on high-fat diets. We identified a neural glucoregulatory function of duodenal PKA signaling. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

Effect of Radiofrequency Denervation on Pain Intensity Among Patients With Chronic Low Back Pain: The Mint Randomized Clinical Trials.

Science.gov (United States)

Juch, Johan N S; Maas, Esther T; Ostelo, Raymond W J G; Groeneweg, J George; Kallewaard, Jan-Willem; Koes, Bart W; Verhagen, Arianne P; van Dongen, Johanna M; Huygen, Frank J P M; van Tulder, Maurits W

2017-07-04

Radiofrequency denervation is a commonly used treatment for chronic low back pain, but high-quality evidence for its effectiveness is lacking. To evaluate the effectiveness of radiofrequency denervation added to a standardized exercise program for patients with chronic low back pain. Three pragmatic multicenter, nonblinded randomized clinical trials on the effectiveness of minimal interventional treatments for participants with chronic low back pain (Mint study) were conducted in 16 multidisciplinary pain clinics in the Netherlands. Eligible participants were included between January 1, 2013, and October 24, 2014, and had chronic low back pain, a positive diagnostic block at the facet joints (facet joint trial, 251 participants), sacroiliac joints (sacroiliac joint trial, 228 participants), or a combination of facet joints, sacroiliac joints, or intervertebral disks (combination trial, 202 participants) and were unresponsive to conservative care. All participants received a 3-month standardized exercise program and psychological support if needed. Participants in the intervention group received radiofrequency denervation as well. This is usually a 1-time procedure, but the maximum number of treatments in the trial was 3. The primary outcome was pain intensity (numeric rating scale, 0-10; whereby 0 indicated no pain and 10 indicated worst pain imaginable) measured 3 months after the intervention. The prespecified minimal clinically important difference was defined as 2 points or more. Final follow-up was at 12 months, ending October 2015. Among 681 participants who were randomized (mean age, 52.2 years; 421 women [61.8%], mean baseline pain intensity, 7.1), 599 (88%) completed the 3-month follow-up, and 521 (77%) completed the 12-month follow-up. The mean difference in pain intensity between the radiofrequency denervation and control groups at 3 months was -0.18 (95% CI, -0.76 to 0.40) in the facet joint trial; -0.71 (95% CI, -1.35 to -0.06) in the sacroiliac joint

Radiofrequency Ablation of Lung Tumors

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Lung Tumors ... and Microwave Ablation of Lung Tumors? What are Radiofrequency and Microwave Ablation of Lung Tumors? Radiofrequency ablation, ...

Mid-Term Vascular Safety of Renal Denervation Assessed by Follow-up MR Imaging

Energy Technology Data Exchange (ETDEWEB)

Schmid, Axel, E-mail: axel.schmid@uk-erlangen.de; Schmieder, Raphael; Lell, Michael; Janka, Rolf [Friedrich-Alexander University Erlangen-Nuremberg, Department of Radiology (Germany); Veelken, Roland; Schmieder, Roland E. [Friedrich-Alexander University Erlangen-Nuremberg, Department of Nephrology and Hypertension (Germany); Uder, Michael [Friedrich-Alexander University Erlangen-Nuremberg, Department of Radiology (Germany); Ott, Christian [Friedrich-Alexander University Erlangen-Nuremberg, Department of Nephrology and Hypertension (Germany)

2016-03-15

Background/AimsRenal denervation (RDN) emerged as a treatment option for reducing blood pressure (BP) in patients with treatment-resistant hypertension (TRH). However, concerns have been raised regarding the incidence of late renal artery stenosis or thromboembolism after RDN. The goal of the current study was, therefore, to conduct a prospective clinical trial on the mid-term vascular integrity of the renal arteries and the perfusion of the renal parenchyma assessed by magnetic resonance imaging (MRI) in the follow-up after catheter-based RDN.MethodsIn our single-centre investigator initiated study, 51 patients with true TRH underwent catheter-based RDN using the Symplicity Flex{sup TM} catheter (Medtronic Inc., Palo Alto, CA). Follow-up MRI was performed at a median of 11 months (interquartile range 6–18 months) after RDN on a 1.5T MR unit. High-resolution MR angiography (MRA) and MRI results were compared to the baseline digital angiography of renal arteries obtained at time of RDN. In case of uncertainties (N = 2) catheter angiography was repeated.ResultsBoth office and 24-h ambulatory BP were significantly reduced 6 and 12 months after RDN. Renal function remained unchanged 6 and 12 months after RDN. In all patients, MRA excluded new or progression of pre-existing low grade renal artery stenosis as well as focal aneurysms at the sites of radiofrequency ablation. In none of the patients new segmental perfusion deficits in either kidney were detected on MRI.ConclusionsNo vascular or parenchymal complications after radiofrequency-based RDN were detected in 51 patients followed up by MRI.

Anterograde Tracing Method using DiI to Label Vagal Innervation of the Embryonic and Early Postnatal Mouse Gastrointestinal Tract

Science.gov (United States)

Murphy, Michelle C.; Fox, Edward A.

2007-01-01

The mouse is an extremely valuable model for studying vagal development in relation to strain differences, genetic variation, gene manipulations, or pharmacological manipulations. Therefore, a method using 1, 1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) was developed for labeling vagal innervation of the gastrointestinal (GI) tract in embryonic and postnatal mice. DiI labeling was adapted and optimized for this purpose by varying several facets of the method. For example, insertion and crushing of DiI crystals into the nerve led to faster DiI diffusion along vagal axons and diffusion over longer distances as compared with piercing the nerve with a micropipette tip coated with dried DiI oil. Moreover, inclusion of EDTA in the fixative reduced leakage of DiI out of nerve fibers that occurred with long incubations. Also, mounting labeled tissue in PBS was superior to glycerol with n-propyl gallate, which resulted in reduced clarity of DiI labeling that may have been due to DiI leaking out of fibers. Optical sectioning of flattened wholemounts permitted examination of individual tissue layers of the GI tract wall. This procedure aided identification of nerve ending types because in most instances each type innervates a different tissue layer. Between embryonic day 12.5 and postnatal day 8, growth of axons into the GI tract, formation and patterning of fiber bundles in the myenteric plexus and early formation of putative afferent and efferent nerve terminals were observed. Thus, the DiI tracing method developed here has opened up a window for investigation during an important phase of vagal development. PMID:17418900

Renal sympathetic denervation in the treatment of resistant hypertension.

Science.gov (United States)

Sánchez-Álvarez, Catalina; González-Vélez, Miguel; Stilp, Erik; Ward, Charisse; Mena-Hurtado, Carlos

2014-12-01

Arterial hypertension (HTN) is a major health problem worldwide. Treatment-resistant hypertension (trHTN) is defined as the failure to achieve target blood pressure despite the concomitant use of maximally tolerated doses of three different antihypertensive medications, including a diuretic. trHTN is associated with considerable morbidity and mortality. Renal sympathetic denervation (RDn) is available and implemented abroad as a strategy for the treatment of trHTN and is currently under clinical investigation in the United States. Selective renal sympathectomy via an endovascular approach effectively decreases renal sympathetic nerve hyperactivity leading to a decrease in blood pressure. The Symplicity catheter, currently under investigation in the United States, is a 6-French compatible system advanced under fluoroscopic guidance via percutaneous access of the common femoral artery to the distal lumen of each of the main renal arteries. Radiofrequency (RF) energy is then applied to the endoluminal surface of the renal arteries via an electrode located at the tip of the catheter. Two clinical trials (Symplicity HTN 1 and Symplicity HTN 2) have shown the efficacy of RDn with a post-procedure decline of 27/17 mmHg at 12 months and 32/12 mmHg at 6 months, respectively, with few minor adverse events. Symplicity HTN-3 study is a, multi-center, prospective, single-blind, randomized, controlled study currently under way and will provide further insights about the safety and efficacy of renal denervation in patients with trHTN.

The SPYRAL HTN Global Clinical Trial Program: Rationale and design for studies of renal denervation in the absence (SPYRAL HTN OFF-MED) and presence (SPYRAL HTN ON-MED) of antihypertensive medications.

Science.gov (United States)

Kandzari, David E; Kario, Kazuomi; Mahfoud, Felix; Cohen, Sidney A; Pilcher, Garrett; Pocock, Stuart; Townsend, Raymond; Weber, Michael A; Böhm, Michael

2016-01-01

Renal sympathetic activation plays a key role in the pathogenesis of hypertension, as demonstrated by high renal norepinephrine spillover into plasma of patients with essential hypertension. Renal denervation has demonstrated a significant reduction in blood pressure in unblinded studies of hypertensive patients. The SYMPLICITY HTN-3 trial, the first prospective, masked, randomized study of renal denervation versus sham control, failed its primary efficacy end point and raised important questions around potentially confounding factors, such as drug changes and adherence, study population, and procedural methods. The SPYRAL HTN Global Clinical Trial Program is designed to address limitations associated with predicate studies and provide insight into the impact of pharmacotherapy on renal denervation efficacy. The 2 initial trials of the program focus on the effect of renal denervation using the Symplicity Spyral multielectrode renal denervation catheter in hypertensive patients in the absence (SPYRAL HTN OFF-MED) and presence (SPYRAL HTN ON-MED) of antihypertensive medications. The SPYRAL HTN ON-MED study requires patients to be treated with a consistent triple therapy antihypertensive regimen, whereas the SPYRAL HTN OFF-MED study includes a 3- to 4-week drug washout period followed by a 3-month efficacy and safety end point in the absence of antihypertensive medications. The studies will randomize patients with combined systolic-diastolic hypertension to renal denervation or sham procedure. Both studies allow renal denervation treatments in renal artery branches and accessories. These studies will inform the design of the second pivotal phase of the program, which will more definitively analyze the antihypertensive effect of renal denervation. Copyright © 2015 Elsevier Inc. All rights reserved.

The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials.

Science.gov (United States)

Lee, Chang-Hyun; Chung, Chun Kee; Kim, Chi Heon

2017-11-01

Radiofrequency denervation is commonly used for the treatment of chronic facet joint pain that has been refractory to more conservative treatments, although the evidence supporting this treatment has been controversial. We aimed to elucidate the precise effects of radiofrequency denervation in patients with low back pain originating from the facet joints relative to those obtained using control treatments, with particular attention to consistency in the denervation protocol. A meta-analysis of randomized controlled trials was carried out. Adult patients undergoing radiofrequency denervation or control treatments (sham or epidural block) for facet joint disease of the lumbar spine comprised the patient sample. Visual analog scale (VAS) pain scores were measured and stratified by response of diagnostic block procedures. We searched PubMed, Embase, Web of Science, and the Cochrane Database for randomized controlled trials regarding radiofrequency denervation and control treatments for back pain. Changes in VAS pain scores of the radiofrequency group were compared with those of the control group as well as the minimal clinically important difference (MCID) for back pain VAS. Meta-regression model was developed to evaluate the effect of radiofrequency treatment according to responses of diagnostic block while controlling for other variables. We then calculated mean differences and 95% confidence intervals (CIs) using random-effects models. We included data from seven trials involving 454 patients who had undergone radiofrequency denervation (231 patients) and control treatments such as sham or epidural block procedures (223 patients). The radiofrequency group exhibited significantly greater improvements in back pain score when compared with the control group for 1-year follow-up. Although the average improvement in VAS scores exceeded the MCID, the lower limit of the 95% CI encompassed the MCID. A subgroup of patients who responded very well to diagnostic block

Electrical stimulation attenuates morphological alterations and prevents atrophy of the denervated cranial tibial muscle.

Science.gov (United States)

Bueno, Cleuber Rodrigo de Souza; Pereira, Mizael; Favaretto, Idvaldo Aparecido; Bortoluci, Carlos Henrique Fachin; Santos, Thais Caroline Pereira Dos; Dias, Daniel Ventura; Daré, Letícia Rossi; Rosa, Geraldo Marco

2017-01-01

To investigate if electrical stimulation through Russian current is able to maintain morphology of the cranial tibial muscle of experimentally denervated rats. Thirty-six Wistar rats were divided into four groups: the Initial Control Group, Final Control Group, Experimental Denervated and Treated Group, Experimental Denervated Group. The electrostimulation was performed with a protocol of Russian current applied three times per week, for 45 days. At the end, the animals were euthanized and histological and morphometric analyses were performed. Data were submitted to statistical analysis with a significance level of pprotocolo de corrente russa aplicada três vezes por semanas, durante 45 dias. Ao final, os animais foram eutanasiados e, em seguida, foram realizadas as análises histológica e morfométrica. Os dados foram submetidos à análise estatística, com nível de significância de p<0,05. Os Grupos Experimental Desnervado e o Grupo Experimental Desnervado Tratado apresentaram área de secção transversal da fibra menor quando comparados ao Grupo Controle Final. Entretanto, constatou-se diferença significativa entre o Grupo Experimental Desnervado e o Grupo Experimental Desnervado Tratado, mostrando que a estimulação elétrica minimizou atrofia muscular. Ainda, observou-se que o Grupo Experimental Desnervado Tratado apresentou resultados semelhantes ao Grupo Controle Inicial. A estimulação elétrica por meio da corrente russa foi favorável na manutenção da morfologia do músculo tibial cranial desnervado experimentalmente, minimizando a atrofia muscular.

Intracellular uptake and degradation of extracellular tracers in mouse skeletal muscle in vitro: the effect of denervation

International Nuclear Information System (INIS)

Libelius, R.; Lundquist, I.; Templeton, W.; Thesleff, S.

1978-01-01

Innervated and chronically denervated mouse skeletal muscles have been incubated under various conditions in a Ringer solution containing one of the three macromolecules [ 3 H] α-neurotoxin, [ 3 H]inulin and horseradish peroxidase. Following extensive wash-out for 4 h of the extracellular compartment, the amount of each macromolecule retained intracellularly was obtained. Intracellular uptake of a [ 3 H]monoacetylated α-neurotoxin in vitro at 37 C was found to be increased in denervated mouse extensor digitorum longus muscles compared to innervated control muscles. Similarly, the uptake in vitro at 37 C of [ 3 H] inulin and horseradish peroxidase was also increased in denervated muscles. At 4 C the uptake of [ 3 H]inulin and horseradish peroxidase was markedly reduced. Protamine was found to stimulate the uptake of [ 3 H]inulin at 37 C, but not at 4 C. Reduction in specific activity by addition of 50-fold excess of unlabelled inulin failed to affect the uptake of [ 3 H]inulin suggesting that this uptake process obeyed bulk kinetics. Furthermore, the endocytized [ 3 H]inulin was found to be strongly retained in the muscles since prolonged washing or addition of unlabelled inulin to the washing solution did not reduce the uptake. Characterization of [ 3 H]inulin taken up by the muscles was performed by gel chromatography on Sephadex G-25. Using a purified [ 3 H]inulin solution it was observed that about 45% of the total radioactivity remaining in the muscles was eluted as [ 3 H]inulin. Additional radioactivity consisted of lower molecular weight compounds. These degradation products of [ 3 H]inulin were only present in the muscle homogenate and were not detected in the incubation solution. The results suggest that intracellular uptake of different macromolecules by endocytosis in skeletal muscles increases following denervation, and that following uptake, degradation of the endocytized material may occur. (author)

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation.

Science.gov (United States)

VonAchen, Paige; Hamann, Jason; Houghland, Thomas; Lesser, John R; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F; Daniels, Mary; Schwartz, Robert S

The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p=0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p=0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p=0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in future clinical trials may improve RDN therapeutic efficacy

Vagal Nerve Stimulator Malfunction with Change in Neck Position: Case Report and Literature Review.

Science.gov (United States)

D'Agostino, Erin; Makler, Vyacheslav; Bauer, David F

2018-06-01

Vagal nerve stimulation is a safe and well-tolerated treatment for drug-resistant epilepsy. Complications and failure of the device can result from lead fracture, device malfunction, disconnection, or battery displacement and can result in a variety of symptoms. We present an interesting case of stimulator malfunction with increased impedance change seen only with a change in head position. The patient is a 25-year-old male with a vagal nerve stimulator (VNs) placed for medically refractory epilepsy who presented with neck pain and an electrical pulling sensation in his neck whenever he turned his head to the right. Initial interrogation of the VNs showed normal impedance. Subsequent interrogation with the patient's head turned found increased impedance only when the head was turned to the right. The patient had successful removal and replacement of the device with resolution of his preoperative complaints. Partial lead fracture was seen at explant. VNs malfunction can present in atypical ways. Positional maneuvers may help with its timely diagnosis. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of ablatant composition on the ablation of a fuelling pellet

International Nuclear Information System (INIS)

Chang, C.T.; Thomsen, K.; Piret, S.

1988-01-01

The single species neutral-shielding model for the ablation of a hydrogenic pellet is extended by considering the ablatant as a mixture of four species: molecular and atomic hydrogen, protons and electrons. Compared with the results of the frozen flow, (i.e. the single species molecular hydrogen gas model), results of the analysis showed that the presence of dissociation and ionization effects caused a marked difference of the ablatant state. The attenuations of the incoming electron energy and energy flux, however, are very much similar irrespective of whether the ablated flow is in a frozen or an equilibrium state. The scaling law of the pellet ablation rate with respect to the plasma state of Te, ne and the pellet radius remains the same; the ablation rate is reduced by approximately 15%. To examine the possible existence of a spherical shell around the pellet where most of the incoming electron energy is absorbed, acodmparison is made between the local electron collisional mean free path and the electron Larmor radius. A critical field at the ionization radius is evaluated. An effective spherical energyabsorbing region exists when the local field strength is below the critical value. For a plasma state of low Te and ne, (where the ablatant is hardly ionized), and for one near the thermonuclear condition (where a highly dense ablatant exists near the pellet), the effective energy absorption region is nearly spherical. 20 refs. (author)

Chronic intermittent hypoxia-hypercapnia blunts heart rate responses and alters neurotransmission to cardiac vagal neurons.

Science.gov (United States)

Dyavanapalli, Jhansi; Jameson, Heather; Dergacheva, Olga; Jain, Vivek; Alhusayyen, Mona; Mendelowitz, David

2014-07-01

Patients with obstructive sleep apnoea experience chronic intermittent hypoxia-hypercapnia (CIHH) during sleep that elicit sympathetic overactivity and diminished parasympathetic activity to the heart, leading to hypertension and depressed baroreflex sensitivity. The parasympathetic control of heart rate arises from pre-motor cardiac vagal neurons (CVNs) located in nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMNX). The mechanisms underlying diminished vagal control of heart rate were investigated by studying the changes in blood pressure, heart rate, and neurotransmission to CVNs evoked by acute hypoxia-hypercapnia (H-H) and CIHH. In vivo telemetry recordings of blood pressure and heart rate were obtained in adult rats during 4 weeks of CIHH exposure. Retrogradely labelled CVNs were identified in an in vitro brainstem slice preparation obtained from adult rats exposed either to air or CIHH for 4 weeks. Postsynaptic inhibitory or excitatory currents were recorded using whole cell voltage clamp techniques. Rats exposed to CIHH had increases in blood pressure, leading to hypertension, and blunted heart rate responses to acute H-H. CIHH induced an increase in GABAergic and glycinergic neurotransmission to CVNs in NA and DMNX, respectively; and a reduction in glutamatergic neurotransmission to CVNs in both nuclei. CIHH blunted the bradycardia evoked by acute H-H and abolished the acute H-H evoked inhibition of GABAergic transmission while enhancing glycinergic neurotransmission to CVNs in NA. These changes with CIHH inhibit CVNs and vagal outflow to the heart, both in acute and chronic exposures to H-H, resulting in diminished levels of cardioprotective parasympathetic activity to the heart as seen in OSA patients. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Effects of sympathetic denervation or chronic reserpine on potassium (42K) and chloride (36Cl) efflux from guinea-pig vas deferens

International Nuclear Information System (INIS)

Urquilla, P.R.; Jones, A.W.; Fleming, W.W.

1980-01-01

Potassium ( 42 K) or chloride ( 36 Cl) efflux curves were determined in guinea-pig vas deferens from control, reserpine-treated animals (1 mg/kg/day i.p. for 5 days), and from animals whose vas deferens had been sympathetically denervated 1 week before. Steady-state 42 K turnover in control tissues was 0.0052+-0.0002 min -1 ; neither reserpine treatment nor sympathetic denervation changed this parameter significantly. Control 36 Cl turnover was 0.058+-0.002 min -1 and it was unaffected by either procedure. Methoxamine (3x10 -6 to 10 -4 M) induced dose-related increases in the fractional exchange of 42 K and 36 Cl. These were of greater magnitude after sympathetic denervation or reserpine treatment. Furtrethonium also produced dose-dependent increases in 42 K efflux; its dose-response curve was shifted 2.6-fold to the left of the control curve by reserpine treatment. These results indicate that interruption of adrenergic transmission to the guinea-pig vas deferens is associated with increased changes in membrane permeability to Cl and possibly K in response to drug activation of α-adrenergic and cholinegic receptors. It is suggested that the supersensitivity phenomenon observed in the guinea-pig vas deferens after reserpine or sympathetic denervation is, in part, related to improved transduction of drug-receptor interaction into ionic permeability changes. (Auth.)

Current Status of Renal Denervation in Hypertension.

Science.gov (United States)

Briasoulis, Alexander; Bakris, George L

2016-11-01

Over the past 7 years, prospective cohorts and small randomized controlled studies showed that renal denervation therapy (RDN) in patients with resistant hypertension is safe but associated with variable effects on BP which are not substantially better than medical therapy alone. The failure of the most rigorously designed randomized sham-control study, SYMPLICITY HTN-3, to meet the efficacy endpoints has raised several methodological concerns. However, recently reported studies and ongoing trials with improved procedural characteristics, identification of patients with true treatment-resistant hypertension on appropriate antihypertensive regimens further explore potential benefits of RDN. The scope of this review is to summarize evidence from currently completed studies on RDN and discuss future perspectives of RDN therapy in patients with resistant hypertension.

Laser ablation principles and applications

CERN Document Server

1994-01-01

Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

Microwave Ablation Compared with Radiofrequency Ablation for Breast Tissue in an Ex Vivo Bovine Udder Model

International Nuclear Information System (INIS)

Tanaka, Toshihiro; Westphal, Saskia; Isfort, Peter; Braunschweig, Till; Penzkofer, Tobias; Bruners, Philipp; Kichikawa, Kimihiko; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2012-01-01

Purpose: To compare the effectiveness of microwave (MW) ablation with radiofrequency (RF) ablation for treating breast tissue in a nonperfused ex vivo model of healthy bovine udder tissue. Materials and Methods: MW ablations were performed at power outputs of 25W, 35W, and 45W using a 915-MHz frequency generator and a 2-cm active tip antenna. RF ablations were performed with a bipolar RF system with 2- and 3-cm active tip electrodes. Tissue temperatures were continuously monitored during ablation. Results: The mean short-axis diameters of the coagulation zones were 1.34 ± 0.14, 1.45 ± 0.13, and 1.74 ± 0.11 cm for MW ablation at outputs of 25W, 35W, and 45W. For RF ablation, the corresponding values were 1.16 ± 0.09 and 1.26 ± 0.14 cm with electrodes having 2- and 3-cm active tips, respectively. The mean coagulation volumes were 2.27 ± 0.65, 2.85 ± 0.72, and 4.45 ± 0.47 cm 3 for MW ablation at outputs of 25W, 35W, and 45W and 1.18 ± 0.30 and 2.29 ± 0.55 cm 3 got RF ablation with 2- and 3-cm electrodes, respectively. MW ablations at 35W and 45W achieved significantly longer short-axis diameters than RF ablations (P < 0.05). The highest tissue temperature was achieved with MW ablation at 45W (P < 0.05). On histological examination, the extent of the ablation zone in MW ablations was less affected by tissue heterogeneity than that in RF ablations. Conclusion: MW ablation appears to be advantageous with respect to the volume of ablation and the shape of the margin of necrosis compared with RF ablation in an ex vivo bovine udder.

Benign thyroid nodule unresponsive to radiofrequency ablation treated with laser ablation: a case report.

Science.gov (United States)

Oddo, Silvia; Balestra, Margherita; Vera, Lara; Giusti, Massimo

2018-05-11

Radiofrequency ablation and laser ablation are safe and effective techniques for reducing thyroid nodule volume, neck symptoms, and cosmetic complaints. Therapeutic success is defined as a nodule reduction > 50% between 6 and 12 months after the procedure, but a percentage of nodules inexplicably do not respond to thermal ablation. We describe the case of a young Caucasian woman with a solid benign thyroid nodule who refused surgery and who had undergone radiofrequency ablation in 2013. The nodule did not respond in terms of either volume reduction or improvement in neck symptoms. After 2 years, given the patient's continued refusal of thyroidectomy, we proposed laser ablation. The nodule displayed a significant volume reduction (- 50% from radiofrequency ablation baseline volume, - 57% from laser ablation baseline), and the patient reported a significant improvement in neck symptoms (from 6/10 to 1/10 on a visual analogue scale). We conjecture that some benign thyroid nodules may be intrinsically resistant to necrosis when one specific ablation technique is used, but may respond to another technique. To the best of our knowledge, this is the first description of the effect of performing a different percutaneous ablation technique in a nodule that does not respond to radiofrequency ablation.

How long does denervation take in poliomyelitis? Or is it a lifetime?”

Directory of Open Access Journals (Sweden)

Mehmet Guney Senol

2017-01-01

Full Text Available Background and Objective: This study aims to determine the period of reinnervation in patients with poliomyelitis. This research was conducted to identify the appearance of denervation potentials in patients with poliomyelitis as indicators for reinnervation. Materials and Methods: A total of 246 male patients with poliomyelitis were assessed electrophysiologically between 1988 and 2007. The mean age was 22.8 (18–42. It has been an average of 19.9 ± 4.9 years since the beginning of complaints from the patients. Results: The patients had no complaints of newly developing muscle weakness, fatigue, muscle and joint pain, and difficulties in breathing and swallowing. Neurological examinations revealed the absence of myotomal pain and sensory loss. Upon assessment of the patients' limbs, the following findings were revealed: two patients had left upper and lower limb involvement, two patients had left upper and right lower limb involvement, 6 patients had left upper limb involvement, 12 patients had both lower limb involvement, 105 patients had left lower limb involvement, 1 patient had both upper limb involvement, 2 patients had right lower and upper limb involvement, 12 patients had right upper limb involvement, 6 patients had both lower limb involvement, 95 patients had right lower limb involvement, and 3 had all the three extremities affected. The needle electromyography revealed the presence of denervation potentials in 25.2% (62 of the patients. Conclusion: When poliovirus attacks the motor neuron, this neuron may be completely destroyed, damaged, or unaffected. Reinnervation occurs when nearby functioning motor units send out terminal axon sprouts to reinnervate the damaged muscle fibers. As a consequence of poliomyelitis, several muscle fibers become atrophic and fibrotic, but others continue to survive. This study showed that patients with a history of poliomyelitis experienced denervation with subsequent reinnervation for many years.

Safety and long-term effects of renal denervation: Rationale and design of the Dutch registry

NARCIS (Netherlands)

Sanders, M.F.; Blankestijn, P.J.; Voskuil, M.; Spiering, W.; Vonken, E.J.; Rotmans, J.I.; Hoeven, B.L. van der; Daemen, J.; Meiracker, A.H. van den; Kroon, A.A.; Haan, M.W. de; Das, M.; Bax, M.; Meer, I.M. van der; Overhagen, H. van; Born, B.J. van den; Brussel, P.M. van; Valk, P.H. van der; Gregoor, P.J. Smak; Meuwissen, M.; Gomes, M.E.; Ophuis, T. Oude; Troe, E.; Tonino, W.A.; Konings, C.J.; Vries, P.A. de; Balen, A. van; Heeg, J.E.; Smit, J.J.; Elvan, A.; Steggerda, R.; Niamut, S.M.; Peels, J.O.; Swart, J.B. de; Wardeh, A.J.; Groeneveld, J.H.; Linden, E. van der; Hemmelder, M.H.; Folkeringa, R.; Stoel, M.G.; Kant, G.D.; Herrman, J.P.; Wissen, S. van; Deinum, J.; Westra, S.W.; Aengevaeren, W.R.; Parlevliet, K.J.; Schramm, A.; Jessurun, G.A.; Rensing, B.J.; Winkens, M.H.; Wierema, T.K.; Santegoets, E.; Lipsic, E.; Houwerzijl, E.; Kater, M.; Allaart, C.P.; Nap, A.; Bots, M.L.

2016-01-01

BACKGROUND: Percutaneous renal denervation (RDN) has recently been introduced as a treatment for therapyresistant hypertension. Also, it has been suggested that RDN may be beneficial for other conditions characterised by increased sympathetic nerve activity. There are still many uncertainties with

Safety and long-term effects of renal denervation : Rationale and design of the Dutch registry

NARCIS (Netherlands)

Sanders, M. F.; Blankestijn, P. J.; Voskuil, M.; Spiering, W.; Vonken, E. J.; Rotmans, J. I.; van der Hoeven, B. L.; Daemen, J.; van den Meiracker, A. H.; Kroon, A. A.; de Haan, M.W.; Das, M.; Bax, M.; van der Meer, I. M.; van Overhagen, H.; van den Born, B. J H; van Brussel, P. M.; van der Valk, P.H.M.; Smak Gregoor, P. J H; Meuwissen, M.; Gomes, M. E R; Oude Ophuis, T.; Troe, E.; Tonino, W. A L; Konings, C. J A M; de Vries, P. A M; van Balen, A.; Heeg, J. E.; Smit, J. J J; Elvan, A.; Steggerda, R.; Niamut, S. M L; Peels, J. O J; de Swart, J. B R M; Wardeh, A. J.; Groeneveld, J. H M; van der Linden, E.; Hemmelder, M. H.; Folkeringa, R.; Stoel, M. G.; Kant, G. D.; Herrman, J. P R; van Wissen, S.; Deinum, J.; Westra, S. W.; Aengevaeren, W. R M; Parlevliet, K. J.; Schramm, A.; Jessurun, G. A J; Rensing, B. J W M; Winkens, M. H M; Wierema, T. K A; Santegoets, E.; Lipsic, E.; Houwerzijl, E.; Kater, M.; Allaart, C. P.; Nap, A.; Bots, M. L.

BACKGROUND: Percutaneous renal denervation (RDN) has recently been introduced as a treatment for therapy-resistant hypertension. Also, it has been suggested that RDN may be beneficial for other conditions characterised by increased sympathetic nerve activity. There are still many uncertainties with

Safety and long-term effects of renal denervation : Rationale and design of the Dutch registry

NARCIS (Netherlands)

Sanders, M. F.; Blankestijn, P. J.; Voskuil, M.; Spiering, W.; Vonken, E. J.; Rotmans, J. I.; van der Hoeven, B. L.; Daemen, J.; van den Meiracker, A. H.; Kroon, A. A.; de Haan, M. W.; Das, M.; Bax, M.; van der Meer, I. M.; van Overhagen, H.; van den Born, B. J. H.; van Brussel, P. M.; van der Valk, P. H. M.; Gregoor, P. J. H. Smak; Meuwissen, M.; Gomes, M. E. R.; Ophuis, T. Oude; Troe, E.; Tonino, W. A. L.; Konings, C. J. A. M.; de Vries, P. A. M.; van Balen, A.; Heeg, J. E.; Smit, J. J. J.; Elvan, A.; Steggerda, R.; Niamut, S. M. L.; Peels, J. O. J.; de Swart, J. B. R. M.; Wardeh, A. J.; Groeneveld, J. H. M.; van der Linden, E.; Hemmelder, M. H.; Folkeringa, R.; Stoel, M. G.; Kant, G. D.; Herrman, J. P. R.; van Wissen, S.; Deinum, J.; Westra, S. W.; Aengevaeren, W. R. M.; Parlevliet, K. J.; Schramm, A.; Jessurun, G. A. J.; Rensing, B. J. W. M.; Winkens, M. H. M.; Wierema, T. K. A.; Santegoets, E.; Lipsic, E.; Houwerzijl, E.; Kater, M.; Allaart, C. P.; Nap, A.; Bots, M. L.

Background: Percutaneous renal denervation (RDN) has recently been introduced as a treatment for therapy-resistant hypertension. Also, it has been suggested that RDN may be beneficial for other conditions characterised by increased sympathetic nerve activity. There are still many uncertainties with

[Endovascular radiofrequency denervation of renal arteries as an innovation method of treatment of refractory arterial hypertension. First experience in Russia].

Science.gov (United States)

Danilov, N M; Matchin, Iu G; Chazova, I E

2012-01-01

Excessive activation of the sympathetic nervous system forms the basis of pathogenesis of essential arterial hypertension (AH). The present work was aimed at evaluating efficacy and safety of endovascular radiofrequency denervation of renal arteries in patients with AH refractory AH based on the initial first experience in with using this methodology in the Russian Federation. The interventions were carried out on December 14-15th, 2011 in the first five patients presenting with AH refractory to antihypertensive therapy consisting of three and more drugs in therapeutic doses, one of which was a diuretic. The selection criteria were systolic arterial pressure (SAP) ≥160 mm Hg or ≥150 mm Hg in the presence of type 2 diabetes mellitus. The obligatory conditions for selection were the preserved renal function [glomerular filtration rate (GFR) ≥45 ml/min] and the absence of the secondary form of AH. The procedure of denervation was performed in the conditions of roentgen-operating room using special Medtronic Ardian Simplicity Catheter System™. In all cases we managed to perform bilateral denervation of renal arteries with the radiofrequency effect in not less than 4 zones of each of vessels. Efficacy of each of the effect was registered with due regard for reaching certain temperature and values of impedance. The interventions were not accompanied by the development of any complications either in the area of manipulations or the site of puncture. Neither were there any complications from the side of the cardiovascular or excretory systems of the body. Diurnal monitoring of AP (DMAP) registered a significant decrease in SAP averagely from 174±12 to 145±10 mm Hg three days after the intervention. A persistent antihypertensive effect was confirmed by the DMAP findings one month after denervation - the SAP level averagely amounted to 131±6 mm Hg. Endovascular radiofrequency denervation of renal arteries is a safe and efficient method of treatment of AH resistant

Increase in Volume of Ablation Zones during Follow-up Is Highly Suggestive of Ablation Site Recurrence in Colorectal Liver Metastases Treated with Radiofrequency Ablation

NARCIS (Netherlands)

Kele, Petra G.; de Jong, Koert P.; van der Jagt, Eric J.

Purpose: To test the hypothesis that volume changes of ablation zones (AZs) on successive computed tomography (CT) scans could predict ablation site recurrences (ASRs) in patients with colorectal liver metastases treated by radiofrequency (RF) ablation. Materials and Methods: RF ablation was

Voltage and pace-capture mapping of linear ablation lesions overestimates chronic ablation gap size.

Science.gov (United States)

O'Neill, Louisa; Harrison, James; Chubb, Henry; Whitaker, John; Mukherjee, Rahul K; Bloch, Lars Ølgaard; Andersen, Niels Peter; Dam, Høgni; Jensen, Henrik K; Niederer, Steven; Wright, Matthew; O'Neill, Mark; Williams, Steven E

2018-04-26

Conducting gaps in lesion sets are a major reason for failure of ablation procedures. Voltage mapping and pace-capture have been proposed for intra-procedural identification of gaps. We aimed to compare gap size measured acutely and chronically post-ablation to macroscopic gap size in a porcine model. Intercaval linear ablation was performed in eight Göttingen minipigs with a deliberate gap of ∼5 mm left in the ablation line. Gap size was measured by interpolating ablation contact force values between ablation tags and thresholding at a low force cut-off of 5 g. Bipolar voltage mapping and pace-capture mapping along the length of the line were performed immediately, and at 2 months, post-ablation. Animals were euthanized and gap sizes were measured macroscopically. Voltage thresholds to define scar were determined by receiver operating characteristic analysis as voltage, pace-capture, and ablation contact force maps. All modalities overestimated chronic gap size, by 1.4 ± 2.0 mm (ablation contact force map), 5.1 ± 3.4 mm (pace-capture), and 9.5 ± 3.8 mm (voltage mapping). Error on ablation contact force map gap measurements were significantly less than for voltage mapping (P = 0.003, Tukey's multiple comparisons test). Chronically, voltage mapping and pace-capture mapping overestimated macroscopic gap size by 11.9 ± 3.7 and 9.8 ± 3.5 mm, respectively. Bipolar voltage and pace-capture mapping overestimate the size of chronic gap formation in linear ablation lesions. The most accurate estimation of chronic gap size was achieved by analysis of catheter-myocardium contact force during ablation.

An approach to contouring the dorsal vagal complex for radiotherapy planning

Energy Technology Data Exchange (ETDEWEB)

O' Steen, Lillie; Amdur, Robert J., E-mail: amdurr@shands.ufl.edu

2016-04-01

Multiple studies suggest that radiation dose to the area of the brainstem called the “dorsal vagal complex (DVC)” influences the frequency of nausea and vomiting during radiotherapy. The purpose of this didactic article is to describe the step-by-step process that we use to contour the general area of the DVC on axial computed tomography (CT) images as would be done for radiotherapy planning. The contouring procedure that we describe for contouring the area of the DVC is useful to medical dosimetrists and radiation oncologists.

Pulmonary ablation: a primer.

Science.gov (United States)

Roberton, Benjamin J; Liu, David; Power, Mark; Wan, John M C; Stuart, Sam; Klass, Darren; Yee, John

2014-05-01

Percutaneous image-guided thermal ablation is safe and efficacious in achieving local control and improving outcome in the treatment of both early stage non-small-cell lung cancer and pulmonary metastatic disease, in which surgical treatment is precluded by comorbidity, poor cardiorespiratory reserve, or unfavorable disease distribution. Radiofrequency ablation is the most established technology, but new thermal ablation technologies such as microwave ablation and cryoablation may offer some advantages. The use of advanced techniques, such as induced pneumothorax and the popsicle stick technique, or combining thermal ablation with radiotherapy, widens the treatment options available to the multidisciplinary team. The intent of this article is to provide the reader with a practical knowledge base of pulmonary ablation by concentrating on indications, techniques, and follow-up. Copyright © 2014 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Safety and long-term effects of renal denervation: Rationale and design of the Dutch registry

NARCIS (Netherlands)

Sanders, M. F.; Blankestijn, P. J.; Voskuil, M.; Spiering, W.; Vonken, E. J.; Rotmans, J. I.; van der Hoeven, B. L.; Daemen, J.; van den Meiracker, A. H.; Kroon, A. A.; de Haan, M. W.; Das, M.; Bax, M.; van der Meer, I. M.; van Overhagen, H.; van den Born, B. J. H.; van Brussel, P. M.; van der Valk, P. H. M.; Smak Gregoor, P. J. H.; Meuwissen, M.; Gomes, M. E. R.; Oude Ophuis, T.; Troe, E.; Tonino, W. A. L.; Konings, C. J. A. M.; de Vries, P. A. M.; van Balen, A.; Heeg, J. E.; Smit, J. J. J.; Elvan, A.; Steggerda, R.; Niamut, S. M. L.; Peels, J. O. J.; de Swart, J. B. R. M.; Wardeh, A. J.; Groeneveld, J. H. M.; van der Linden, E.; Hemmelder, M. H.; Folkeringa, R.; Stoel, M. G.; Kant, G. D.; Herrman, J. P. R.; van Wissen, S.; Deinum, J.; Westra, S. W.; Aengevaeren, W. R. M.; Parlevliet, K. J.; Schramm, A.; Jessurun, G. A. J.; Rensing, B. J. W. M.; Winkens, M. H. M.; Wierema, T. K. A.; Santegoets, E.; Lipsic, E.; Houwerzijl, E.; Kater, M.; Allaart, C. P.; Nap, A.; Bots, M. L.

2016-01-01

Percutaneous renal denervation (RDN) has recently been introduced as a treatment for therapy-resistant hypertension. Also, it has been suggested that RDN may be beneficial for other conditions characterised by increased sympathetic nerve activity. There are still many uncertainties with regard to

Improved neurological outcome by intramuscular injection of human amniotic fluid derived stem cells in a muscle denervation model.

Directory of Open Access Journals (Sweden)

Chun-Jung Chen

Full Text Available The skeletal muscle develops various degrees of atrophy and metabolic dysfunction following nerve injury. Neurotrophic factors are essential for muscle regeneration. Human amniotic fluid derived stem cells (AFS have the potential to secrete various neurotrophic factors necessary for nerve regeneration. In the present study, we assess the outcome of neurological function by intramuscular injection of AFS in a muscle denervation and nerve anastomosis model.Seventy two Sprague-Dawley rats weighing 200-250 gm were enrolled in this study. Muscle denervation model was conducted by transverse resection of a sciatic nerve with the proximal end sutured into the gluteal muscle. The nerve anastomosis model was performed by transverse resection of the sciatic nerve followed by four stitches reconnection. These animals were allocated to three groups: control, electrical muscle stimulation, and AFS groups.NT-3 (Neurotrophin 3, BDNF (Brain derived neurotrophic factor, CNTF (Ciliary neurotrophic factor, and GDNF (Glia cell line derived neurotrophic factor were highly expressed in AFS cells and supernatant of culture medium. Intra-muscular injection of AFS exerted significant expression of several neurotrophic factors over the distal end of nerve and denervated muscle. AFS caused high expression of Bcl-2 in denervated muscle with a reciprocal decrease of Bad and Bax. AFS preserved the muscle morphology with high expression of desmin and acetylcholine receptors. Up to two months, AFS produced significant improvement in electrophysiological study and neurological functions such as SFI (sciatic nerve function index and Catwalk gait analysis. There was also significant preservation of the number of anterior horn cells and increased nerve myelination as well as muscle morphology.Intramuscular injection of AFS can protect muscle apoptosis and likely does so through the secretion of various neurotrophic factors. This protection furthermore improves the nerve

Functional reinnervation of vocal folds after selective laryngeal adductor denervation-reinnervation surgery for spasmodic dysphonia.

Science.gov (United States)

DeConde, Adam S; Long, Jennifer L; Armin, Bob B; Berke, Gerald S

2012-09-01

Selective laryngeal adductor denervation-reinnervation surgery (SLAD-R) offers a viable surgical alternative for patients with adductor spasmodic dysphonia refractory to botulinum toxin injections. SLAD-R selectively denervates the symptomatic thyroarytenoid muscle by dividing the distal adductor branch of the recurrent laryngeal nerve (RLN), and preventing reinnervation, by the proximal RLN and maintaining vocal fold bulk and tone by reinnervating the distal RLN with the ansa cervicalis. We present a patient who had previously undergone successful SLAD-R but presented 10 years postoperatively with a new regional dystonia involving his strap muscles translocated to his reinnervated larynx by his previous ansa-RLN neurorraphy. The patient's symptomatic vocal fold adduction resolved completely on division of the ansa-RLN neurorraphy confirming successful selective functional reinnervation of vocal fold adductors by the ansa cervicalis. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

The effects of chronic consumption of heroin on basal and vagal electrical-stimulated gastric acid and pepsin secretion in rat.

Science.gov (United States)

Rafsanjani, Fatemeh N; Maghouli, Fatemeh; Vahedian, Jalal; Esmaeili, Farzaneh

2004-10-01

Addiction to opium and heroin is not only an important social and individual problem in the world but it also affects the human physiology and multiple systems. The aim of this study is to determine the effects of chronic heroin consumption on basal and vagus electrical-stimulated total gastric acid and pepsin secretion in rats. The study was carried out in the Department of Physiology, Kerman University of Medical Sciences, Iran from August 2002 to June 2003. Both male and female rats weighing 200-250 g were used. Rats received daily doses of heroin intraperitoneally starting from 0.2 mg/kg to 0.1 mg/kg/day up to the maintenance level of 0.7 mg/kg and continued until day 12. After anesthesia, tracheotomy and laparotomy, gastric effluents were collected by washout technique with a 15 minutes interval. The total titrable acid was measured by manual titrator, and the total pepsin content was measured by Anson's method. Vagal electrical stimulation was used to stimulate the secretion of acid and pepsin. Heroin results in a significant decrease in total basal acid and pepsin secretions (4.10 +/- 0.18 mmol/15 minutes versus 2.40 +/- 0.16 mmol/15 minutes for acid, pacid and pepsin secretions in vagotomized condition. Heroin also causes a significant decrease in vagal-electrically stimulated acid and pepsin secretions (14.70 +/- 0.54 mmol/15 minutes versus 4.30 +/- 0.21 mmol/15 minutes for acid, pacid and pepsin secretion, but not in vagotomized condition. Heroin may decrease acid secretion by inhibiting vagal release of acetylcholine within the gastric wall. Other probable mechanisms include: presynaptic inhibition of acetylcholine release or depressing the vagal center, inhibition of pentagastrin induced acid secretion, inhibitory effects via central mechanisms, probably mediated by the opiate receptors. Further studies are needed to recognize the actual mechanism.

Cost-effectiveness of renal denervation therapy for the treatment of resistant hypertension in the Netherlands

NARCIS (Netherlands)

Henry, Thea L.; De Brouwer, Bonnie F E; Van Keep, Marjolijn M L; Blankestijn, Peter J.; Bots, Michiel L.; Koffijberg, Hendrik

2015-01-01

Objectives: Safety and efficacy data for catheter-based renal denervation (RDN) in the treatment of resistant hypertension have been used to estimate the cost-effectiveness of this approach. However, there are no Dutch-specific analyses. This study examined the cost-effectiveness of RDN from the

Intraperitoneal injections of low doses of C75 elicit a behaviorally specific and vagal afferent-independent inhibition of eating in rats

Science.gov (United States)

Mansouri, Abdelhak; Aja, Susan; Moran, Timothy H.; Ronnett, Gabriele; Kuhajda, Francis P.; Arnold, Myrtha; Geary, Nori; Langhans, Wolfgang; Leonhardt, Monika

2008-01-01

Central and intraperitoneal C75, an inhibitor of fatty acid synthase and stimulator of carnitine palmitoyl-transferase-1, inhibits eating in mice and rats. Mechanisms involved in feeding inhibition after central C75 have been identified, but little is yet known about how systemic C75 might inhibit eating. One issue is whether intraperitoneal C75 reduces food intake in rats by influencing normal physiological controls of food intake or acts nonselectively, for example by eliciting illness or aversion. Another issue relates to whether intraperitoneal C75 acts centrally or, similar to some other peripheral metabolic controls of eating, activates abdominal vagal afferents to inhibit eating. To further address these questions, we investigated the effects of intraperitoneal C75 on spontaneous meal patterns and the formation of conditioned taste aversion (CTA). We also tested whether the eating inhibitory effect of intraperitoneal C75 is vagally mediated by testing rats after either total subdiaphragmatic vagotomy (TVX) or selective subdiaphragmatic vagal deafferentations (SDA). Intraperitoneal injection of 3.2 and 7.5 mg/kg of C75 significantly reduced food intake 3, 12, and 24 h after injection by reducing the number of meals without affecting meal size, whereas 15 mg/kg of C75 reduced both meal number and meal size. The two smaller doses of C75 failed to induce a CTA, but 15 mg/kg C75 did. The eating inhibitory effect of C75 was not diminished in either TVX or SDA rats. We conclude that intraperitoneal injections of low doses of C75 inhibit eating in a behaviorally specific manner and that this effect does not require abdominal vagal afferents. PMID:18667714

Ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma using microwave and radiofrequency ablation

Energy Technology Data Exchange (ETDEWEB)

Xu, H.-X.; Xie, X.-Y.; Lu, M.-D. E-mail: lumd@21cn.com; Chen, J.-W.; Yin, X.-Y.; Xu, Z.-F.; Liu, G.-J

2004-01-01

AIM: To investigate the therapeutic efficacy of thermal ablation for treatment of hepatocellular carcinoma (HCC) using microwave and radiofrequency (RF) energy application. MATERIALS AND METHODS: A total of 190 nodules in 97 patients (84 male, 13 female; mean age 53.4 years, range 24-74 years) with HCC were treated with microwave or RF ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours{<=}2.0, 2.1-3.9 and {>=}4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours{<=}2.0, 2.1-3.9 and {>=}4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child-Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up.

Ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma using microwave and radiofrequency ablation

International Nuclear Information System (INIS)

Xu, H.-X.; Xie, X.-Y.; Lu, M.-D.; Chen, J.-W.; Yin, X.-Y.; Xu, Z.-F.; Liu, G.-J.

2004-01-01

AIM: To investigate the therapeutic efficacy of thermal ablation for treatment of hepatocellular carcinoma (HCC) using microwave and radiofrequency (RF) energy application. MATERIALS AND METHODS: A total of 190 nodules in 97 patients (84 male, 13 female; mean age 53.4 years, range 24-74 years) with HCC were treated with microwave or RF ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours≤2.0, 2.1-3.9 and ≥4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours≤2.0, 2.1-3.9 and ≥4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child-Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up

Ablation threshold and ablation mechanism transition of polyoxymethylene irradiated by CO2 laser.

Science.gov (United States)

Li, Gan; Cheng, Mousen; Li, Xiaokang

2016-09-01

Polyoxymethylene (POM) decomposes gradually as it is heated up by the irradiation of CO2 laser; the long-chain molecules of POM are broken into short chains, which leads to the lowering of the melting point and the critical temperature of the ablation products. When the product temperature is above the melting point, ablation comes up in the way of vaporization; when the product temperature is higher than the critical temperature, all liquid products are transformed into gas instantly and the ablation mechanism is changed. The laser fluence at which significant ablation is observed is defined as the ablation threshold, and the fluence corresponding to the ablation mechanism changing is denoted as the flyover threshold. In this paper, random pyrolysis is adopted to describe the pyrolytic decomposition of POM, and consequently, the components of the pyrolysis products under different pyrolysis rates are acquired. The Group Contribution method is used to count the thermodynamic properties of the pyrolysis products, and the melting point and the critical temperature of the product mixture are obtained by the Mixing Law. The Knudsen layer relationship is employed to evaluate the ablation mass removal when the product temperature is below the critical temperature. The gas dynamics conservation laws associated with the Jouguet condition are used to calculate the mass removal when the product temperature is higher than the critical temperature. Based on the model, a set of simulations for various laser intensities and lengths are carried out to generalize the relationships between the thresholds and the laser parameters. Besides the ablated mass areal density, which fits the experimental data quite well, the ablation temperature, pyrolysis rate, and product components are also discussed for a better understanding of the ablation mechanism of POM.

Differential Activation of Medullary Vagal Nuclei Caused by Stimulation of Different Esophageal Mechanoreceptors

OpenAIRE

Lang, Ivan M.; Medda, Bidyut K.; Shaker, Reza

2010-01-01

Esophageal mechanorecptors, i.e. muscular slowly adapting tension receptors and mucosal rapidly adapting touch receptors, mediate different sets of reflexes. The aim of this study was to determine the medullary vagal nuclei involved in the reflex responses to activation of these receptors. Thirty-three cats were anesthetized with alpha-chloralose and the esophagus was stimulated by slow balloon or rapid air distension. The physiological effects of the stimuli (N=4) were identified by recordin...

Atrial fibrillation ablation using a closed irrigation radiofrequency ablation catheter.

Science.gov (United States)

Golden, Keith; Mounsey, John Paul; Chung, Eugene; Roomiani, Pahresah; Morse, Michael Andew; Patel, Ankit; Gehi, Anil

2012-05-01

Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open-irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed-irrigated RF catheters create equivalent lesions, but clinical outcomes are limited. A cohort of 195 sequential patients with symptomatic AF underwent stepwise AF ablation (AFA) using a closed-irrigation ablation catheter. Recurrence of AF was monitored and outcomes were evaluated using Kaplan-Meier survival analysis and Cox proportional hazards models. Mean age was 59.0 years, 74.9% were male, 56.4% of patients were paroxysmal and mean duration of AF was 5.4 years. Patients had multiple comorbidities including hypertension (76.4%), tobacco abuse (42.1%), diabetes (17.4%), and obesity (mean body mass index 30.8). The median follow-up was 55.8 weeks. Overall event-free survival was 73.6% with one ablation and 77.4% after reablation (reablation rate was 8.7%). Median time to recurrence was 26.9 weeks. AF was more likely to recur in patients being treated with antiarrhythmic therapy at the time of last follow-up (recurrence rate 30.3% with antiarrhythmic drugs, 13.2% without antiarrhythmic drugs; hazard ratio [HR] 2.2, 95% confidence interval [CI] 1.1-4.4, P = 0.024) and in those with a history of AF greater than 2 years duration (HR 2.7, 95% CI 1.1-6.9, P = 0.038). Our study represents the largest cohort of patients receiving AFA with closed-irrigation ablation catheters. We demonstrate comparable outcomes to those previously reported in studies of open-irrigation ablation catheters. Given the theoretical benefits of a closed-irrigation system, a large head-to-head comparison using this catheter is warranted. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Intracellular uptake and degradation of extracellular tracers in mouse skeletal muscle in vitro: the effect of denervation

Energy Technology Data Exchange (ETDEWEB)

Libelius, R; Lundquist, I; Templeton, W; Thesleff, S [Lund Univ. (Sweden)

1978-01-01

Innervated and chronically denervated mouse skeletal muscles have been incubated under various conditions in a Ringer solution containing one of the three macromolecules (/sup 3/H) ..cap alpha..-neurotoxin, (/sup 3/H)inulin and horseradish peroxidase. Following extensive wash-out for 4 h of the extracellular compartment, the amount of each macromolecule retained intracellularly was obtained. Intracellular uptake of a (/sup 3/H)monoacetylated ..cap alpha..-neurotoxin in vitro at 37 C was found to be increased in denervated mouse extensor digitorum longus muscles compared to innervated control muscles. Similarly, the uptake in vitro at 37 C of (/sup 3/H) inulin and horseradish peroxidase was also increased in denervated muscles. At 4 C the uptake of (/sup 3/H)inulin and horseradish peroxidase was markedly reduced. Protamine was found to stimulate the uptake of (/sup 3/H)inulin at 37 C, but not at 4 C. Reduction in specific activity by addition of 50-fold excess of unlabelled inulin failed to affect the uptake of (/sup 3/H)inulin suggesting that this uptake process obeyed bulk kinetics. Furthermore, the endocytized (/sup 3/H)inulin was found to be strongly retained in the muscles since prolonged washing or addition of unlabelled inulin to the washing solution did not reduce the uptake. Characterization of (/sup 3/H)inulin taken up by the muscles was performed by gel chromatography on Sephadex G-25. Using a purified (/sup 3/H)inulin solution it was observed that about 45% of the total radioactivity remaining in the muscles was eluted as (/sup 3/H)inulin. Additional radioactivity consisted of lower molecular weight compounds. Degradation products of (/sup 3/H)inulin were only present in the muscle homogenate and were not detected in the incubation solution. Results suggest that intracellular uptake of different macromolecules by endocytosis in skeletal muscles increases following denervation, and that following uptake, degradation of the endocytized material may occur.

Cutaneous collateral axonal sprouting re-innervates the skin component and restores sensation of denervated Swine osteomyocutaneous alloflaps.

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Zuhaib Ibrahim

Full Text Available Reconstructive transplantation such as extremity and face transplantation is a viable treatment option for select patients with devastating tissue loss. Sensorimotor recovery is a critical determinant of overall success of such transplants. Although motor function recovery has been extensively studied, mechanisms of sensory re-innervation are not well established. Recent clinical reports of face transplants confirm progressive sensory improvement even in cases where optimal repair of sensory nerves was not achieved. Two forms of sensory nerve regeneration are known. In regenerative sprouting, axonal outgrowth occurs from the transected nerve stump while in collateral sprouting, reinnervation of denervated tissue occurs through growth of uninjured axons into the denervated tissue. The latter mechanism may be more important in settings where transected sensory nerves cannot be re-apposed. In this study, denervated osteomyocutaneous alloflaps (hind- limb transplants from Major Histocompatibility Complex (MHC-defined MGH miniature swine were performed to specifically evaluate collateral axonal sprouting for cutaneous sensory re-innervation. The skin component of the flap was externalized and serial skin sections extending from native skin to the grafted flap were biopsied. In order to visualize regenerating axonal structures in the dermis and epidermis, 50 um frozen sections were immunostained against axonal and Schwann cell markers. In all alloflaps, collateral axonal sprouts from adjacent recipient skin extended into the denervated skin component along the dermal-epidermal junction from the periphery towards the center. On day 100 post-transplant, regenerating sprouts reached 0.5 cm into the flap centripetally. Eight months following transplant, epidermal fibers were visualized 1.5 cm from the margin (rate of regeneration 0.06 mm per day. All animals had pinprick sensation in the periphery of the transplanted skin within 3 months post

Structural remodeling of the heart and its premotor cardioinhibitory vagal neurons following T(5) spinal cord transection.

Science.gov (United States)

Lujan, Heidi L; Janbaih, Hussein; DiCarlo, Stephen E

2014-05-01

Midthoracic spinal cord injury (SCI) is associated with enhanced cardiac sympathetic activity and reduced cardiac parasympathetic activity. The enhanced cardiac sympathetic activity is associated with sympathetic structural plasticity within the stellate ganglia, spinal cord segments T1-T4, and heart. However, changes to cardiac parasympathetic centers rostral to an experimental SCI are relatively unknown. Importantly, reduced vagal activity is a predictor of high mortality. Furthermore, this autonomic dysregulation promotes progressive left ventricular (LV) structural remodeling. Accordingly, we hypothesized that midthoracic spinal cord injury is associated with structural plasticity in premotor (preganglionic parasympathetic neurons) cardioinhibitory vagal neurons located within the nucleus ambiguus as well as LV structural remodeling. To test this hypothesis, dendritic arborization and morphology (cholera toxin B immunohistochemistry and Sholl analysis) of cardiac projecting premotor cardioinhibitory vagal neurons located within the nucleus ambiguus were determined in intact (sham transected) and thoracic level 5 transected (T5X) rats. In addition, LV chamber size, wall thickness, and collagen content (Masson trichrome stain and structural analysis) were determined. Midthoracic SCI was associated with structural changes within the nucleus ambiguus and heart. Specifically, following T5 spinal cord transection, there was a significant increase in cardiac parasympathetic preganglionic neuron dendritic arborization, soma area, maximum dendritic length, and number of intersections/animal. This parasympathetic structural remodeling was associated with a profound LV structural remodeling. Specifically, T5 spinal cord transection increased LV chamber area, reduced LV wall thickness, and increased collagen content. Accordingly, results document a dynamic interaction between the heart and its parasympathetic innervation.

Safety and performance of the next generation EnligHTN™ renal denervation system in patients with drug-resistant, uncontrolled hypertension: The EnligHTN III first-in-human multicentre study

Directory of Open Access Journals (Sweden)

Stephen G. Worthley

2015-08-01

Conclusions: Renal sympathetic denervation using the next generation EnligHTN renal denervation system resulted in safe, rapid, and significant mean office blood pressure reduction that was sustained through 6 months. Future studies will need to address the utility of this system against an appropriate placebo based comparator.

Infant diet, gender and the development of vagal tone stability during the first two years of life

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Postnatal nutrition influences neurodevelopment, including autonomic nervous system components associated with cardiac control. In this study resting vagal tone (V) was measured quarterly during infancy and at 2 years in 146 breast-fed, 143 milk formula-fed, and 137 soy formula-fed infants. Stabilit...

Radiofrequency ablation of pulmonary tumors

Energy Technology Data Exchange (ETDEWEB)

Crocetti, Laura, E-mail: l.crocetti@med.unipi.i [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy); Lencioni, Riccardo [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy)

2010-07-15

The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of solid tumors. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma when liver transplantation or surgical resection are not suitable options and is considered as a viable alternate to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Recently, RF ablation has been demonstrated to be a safe and valuable treatment option for patients with unresectable or medically inoperable lung malignancies. Resection should remain the standard therapy for non-small cell lung cancer (NSCLC) but RF ablation may be better than conventional external-beam radiation for the treatment of the high-risk individual with NSCLC. Initial favourable outcomes encourage combining radiotherapy and RF ablation, especially for treating larger tumors. In the setting of colorectal cancer lung metastases, survival rates provided by RF ablation in selected patients, are substantially higher than those obtained with any chemotherapy regimens and provide indirect evidence that RF ablation therapy improves survival in patients with limited lung metastatic disease.

Impaired growth of denervated muscle contributes to contracture formation following neonatal brachial plexus injury.

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Nikolaou, Sia; Peterson, Elizabeth; Kim, Annie; Wylie, Christopher; Cornwall, Roger

2011-03-02

The etiology of shoulder and elbow contractures following neonatal brachial plexus injury is incompletely understood. With use of a mouse model, the current study tests the novel hypothesis that reduced growth of denervated muscle contributes to contractures following neonatal brachial plexus injury. Unilateral brachial plexus injuries were created in neonatal mice by supraclavicular C5-C6 nerve root excision. Shoulder and elbow range of motion was measured four weeks after injury. Fibrosis, cross-sectional area, and functional length of the biceps, brachialis, and subscapularis muscles were measured over four weeks following injury. Muscle satellite cells were cultured from denervated and control biceps muscles to assess myogenic capability. In a comparison group, shoulder motion and subscapularis length were assessed following surgical excision of external rotator muscles. Shoulder internal rotation and elbow flexion contractures developed on the involved side within four weeks following brachial plexus injury. Excision of the biceps and brachialis muscles relieved the elbow flexion contractures. The biceps muscles were histologically fibrotic, whereas fatty infiltration predominated in the brachialis and rotator cuff muscles. The biceps and brachialis muscles displayed reduced cross-sectional and longitudinal growth compared with the contralateral muscles. The upper subscapularis muscle similarly displayed reduced longitudinal growth, with the subscapularis shortening correlating with internal rotation contracture. However, excision of the external rotators without brachial plexus injury caused no contractures or subscapularis shortening. Myogenically capable satellite cells were present in denervated biceps muscles despite impaired muscle growth in vivo. Injury of the upper trunk of the brachial plexus leads to impaired growth of the biceps and brachialis muscles, which are responsible for elbow flexion contractures, and impaired growth of the subscapularis

Skin denervation does not alter cortical potentials to surface concentric electrode stimulation: A comparison with laser evoked potentials and contact heat evoked potentials.

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La Cesa, S; Di Stefano, G; Leone, C; Pepe, A; Galosi, E; Alu, F; Fasolino, A; Cruccu, G; Valeriani, M; Truini, A

2018-01-01

In the neurophysiological assessment of patients with neuropathic pain, laser evoked potentials (LEPs), contact heat evoked potentials (CHEPs) and the evoked potentials by the intraepidermal electrical stimulation via concentric needle electrode are widely agreed as nociceptive specific responses; conversely, the nociceptive specificity of evoked potentials by surface concentric electrode (SE-PREPs) is still debated. In this neurophysiological study we aimed at verifying the nociceptive specificity of SE-PREPs. We recorded LEPs, CHEPs and SE-PREPs in eleven healthy participants, before and after epidermal denervation produced by prolonged capsaicin application. We also used skin biopsy to verify the capsaicin-induced nociceptive nerve fibre loss in the epidermis. We found that whereas LEPs and CHEPs were suppressed after capsaicin-induced epidermal denervation, the surface concentric electrode stimulation of the same denervated skin area yielded unchanged SE-PREPs. The suppression of LEPs and CHEPs after nociceptive nerve fibre loss in the epidermis indicates that these techniques are selectively mediated by nociceptive system. Conversely, the lack of SE-PREP changes suggests that SE-PREPs do not provide selective information on nociceptive system function. Capsaicin-induced epidermal denervation abolishes laser evoked potentials (LEPs) and contact heat evoked potentials (CHEPs), but leaves unaffected pain-related evoked potentials by surface concentric electrode (SE-PREPs). These findings suggest that unlike LEPs and CHEPs, SE-PREPs are not selectively mediated by nociceptive system. © 2017 European Pain Federation - EFIC®.

Ablative skin resurfacing.

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Agrawal, Nidhi; Smith, Greg; Heffelfinger, Ryan

2014-02-01

Ablative laser resurfacing has evolved as a safe and effective treatment for skin rejuvenation. Although traditional lasers were associated with significant thermal damage and lengthy recovery, advances in laser technology have improved safety profiles and reduced social downtime. CO2 lasers remain the gold standard of treatment, and fractional ablative devices capable of achieving remarkable clinical improvement with fewer side effects and shorter recovery times have made it a more practical option for patients. Although ablative resurfacing has become safer, careful patient selection and choice of suitable laser parameters are essential to minimize complications and optimize outcomes. This article describes the current modalities used in ablative laser skin resurfacing and examines their efficacy, indications, and possible side effects. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Renal denervation prevents long-term sequelae of ischemic renal injury

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Kim, Jinu; Padanilam, Babu J.

2014-01-01

Signals that drive interstitial fibrogenesis after renal ischemia reperfusion injury remain undefined. Sympathetic activation is manifest even in the early clinical stages of chronic kidney disease and is directly related to disease severity. A role for renal nerves in renal interstitial fibrogenesis in the setting of ischemia reperfusion injury has not been studied. In male 129S1/SvImJ mice, ischemia reperfusion injury induced tubulointerstitial fibrosis as indicated by collagen deposition and profibrotic protein expression 4 to 16 days after the injury.. Leukocyte influx, proinflammatory protein expression, oxidative stress, apoptosis, and cell cycle arrest at G2/M phase were enhanced after ischemia reperfusion injury. Renal denervation at the time of injury or up to 1 day post-injury improved histology, decreased proinflammatory/profibrotic responses and apoptosis, and prevented G2/M cell cycle arrest in the kidney. Treatment with afferent nerve-derived calcitonin gene-related peptide (CGRP) or efferent nerve-derived norepinephrine in denervated and ischemia reperfusion injury-induced kidneys mimicked innervation, restored inflammation and fibrosis, induced G2/M arrest, and enhanced TGF-β1 activation. Blocking norepinephrine or CGRP function using respective receptor blockers prevented these effects. Consistent with the in vivo study, treatment with either norepinephrine or CGRP induced G2/M cell cycle arrest in HK-2 proximal tubule cells, whereas antagonists against their respective receptors prevented G2/M arrest. Thus, renal nerve stimulation is a primary mechanism and renal nerve-derived factors drive epithelial cell cycle arrest and the inflammatory cascade causing interstitial fibrogenesis after ischemia reperfusion injury. PMID:25207878

Vagally mediated effects of brain stem dopamine on gastric tone and phasic contractions of the rat.

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Anselmi, L; Toti, L; Bove, C; Travagli, R A

2017-11-01

Dopamine (DA)-containing fibers and neurons are embedded within the brain stem dorsal vagal complex (DVC); we have shown previously that DA modulates the membrane properties of neurons of the dorsal motor nucleus of the vagus (DMV) via DA1 and DA2 receptors. The vagally dependent modulation of gastric tone and phasic contractions, i.e., motility, by DA, however, has not been characterized. With the use of microinjections of DA in the DVC while recording gastric tone and motility, the aims of the present study were 1 ) assess the gastric effects of brain stem DA application, 2 ) identify the DA receptor subtype, and, 3 ) identify the postganglionic pathway(s) activated. Dopamine microinjection in the DVC decreased gastric tone and motility in both corpus and antrum in 29 of 34 rats, and the effects were abolished by ipsilateral vagotomy and fourth ventricular treatment with the selective DA2 receptor antagonist L741,626 but not by application of the selective DA1 receptor antagonist SCH 23390. Systemic administration of the cholinergic antagonist atropine attenuated the inhibition of corpus and antrum tone in response to DA microinjection in the DVC. Conversely, systemic administration of the nitric oxide synthase inhibitor nitro-l-arginine methyl ester did not alter the DA-induced decrease in gastric tone and motility. Our data provide evidence of a dopaminergic modulation of a brain stem vagal neurocircuit that controls gastric tone and motility. NEW & NOTEWORTHY Dopamine administration in the brain stem decreases gastric tone and phasic contractions. The gastric effects of dopamine are mediated via dopamine 2 receptors on neurons of the dorsal motor nucleus of the vagus. The inhibitory effects of dopamine are mediated via inhibition of the postganglionic cholinergic pathway. Copyright © 2017 the American Physiological Society.

Modulation of vagal tone enhances gastroduodenal motility and reduces somatic pain sensitivity

DEFF Research Database (Denmark)

Frøkjaer, J B; Bergmann, S; Brock, C

2016-01-01

algometry, conditioned pain modulation using a cold pressor test and a liquid meal ultrasonographic gastroduodenal motility test were performed. KEY RESULTS: Cardiac vagal tone increased during active treatment with t-VNS and DSB compared to sham (p = 0.009). In comparison to sham, thresholds to bone pain...... increased (p = 0.001), frequency of antral contractions increased (p = 0.004) and gastroduodenal motility index increased (p = 0.016) with active treatment. However, no effect on muscle pain thresholds and conditioned pain modulation was seen. CONCLUSIONS & INFERENCES: This experimental study suggests...

High-Resolution Manometry Evaluation of Pressures at the Pharyngo-upper Esophageal Area in Patients with Oropharyngeal Dysphagia Due to Vagal Paralysis.

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Pinna, Bruno Rezende; Herbella, Fernando A M; de Biase, Noemi; Vaiano, Thays C G; Patti, Marco G

2017-10-01

The motility of the pharynx, upper esophageal sphincter (UES), and proximal esophagus in patients with oropharyngeal dysphagia is still not entirely understood. High-resolution manometry (HRM) was recently added to the armamentarium for the study of this area. This study aims to describe HRM findings in patients with vagal paralysis. Sixteen patients (mean age 54 years, 69% females) with oropharyngeal dysphagia due to unilateral vagal paralysis were prospectively studied. All patients underwent HRM. Motility of the UES and at the topography of the velopharynx and epiglottis were recorded. (1) UES relaxation is compromised in a minority of patients, (2) epiglottis pressure does not follow a specific pattern, (3) vellum is hypotonic in half of the patients, (4) dysphagia is related to a low pharyngeal pressure, not to a flow obstruction at the level of the UES, and (5) aspiration is related to low pressures at the level of the UES and epiglottis and higher pressures at the level of the vellum. Pharyngeal motility is significantly impaired in patients with oropharyngeal dysphagia and unilateral vagal paralysis. In half of the cases, UES resting pressure is preserved due to unilateral innervation and relaxation is normal in most patients. Dysphagia therapy in these patients must be directed toward improvement in the oropharyngeal motility not at the UES.

Acute Vagal Nerve Stimulation Lowers α2 Adrenoceptor Availability

DEFF Research Database (Denmark)

Landau, Anne M.; Dyve, Suzan; Jakobsen, Steen

2015-01-01

Background Vagal nerve stimulation (VNS) emerged as an anti-epileptic therapy, and more recently as a potential antidepressant intervention. Objective/hypothesis We hypothesized that salutary effects of VNS are mediated, at least in part, by augmentation of the inhibitory effects of cortical...... monoaminergic neurotransmission at appropriate receptors, specifically adrenoceptors. Our objective was to measure the effect of acute VNS on α2 adrenoceptor binding. Methods Using positron emission tomography (PET), we measured changes in noradrenaline receptor binding associated with acute VNS stimulation...... electrode in minipigs before and within 30 min of the initiation of 1 mA stimulation. Kinetic analysis with the Logan graphical linearization generated tracer volumes of distribution for each condition. We used an averaged value of the distribution volume of non-displaceable ligand (VND), to calculate...

Urotensin II promotes vagal-mediated bradycardia by activating cardiac-projecting parasympathetic neurons of nucleus ambiguus.

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Brailoiu, Gabriela Cristina; Deliu, Elena; Rabinowitz, Joseph E; Tilley, Douglas G; Koch, Walter J; Brailoiu, Eugen

2014-05-01

Urotensin II (U-II) is a cyclic undecapeptide that regulates cardiovascular function at central and peripheral sites. The functional role of U-II nucleus ambiguus, a key site controlling cardiac tone, has not been established, despite the identification of U-II and its receptor at this level. We report here that U-II produces an increase in cytosolic Ca(2+) concentration in retrogradely labeled cardiac vagal neurons of nucleus ambiguus via two pathways: (i) Ca(2+) release from the endoplasmic reticulum via inositol 1,4,5-trisphosphate receptor; and (ii) Ca(2+) influx through P/Q-type Ca(2+) channels. In addition, U-II depolarizes cultured cardiac parasympathetic neurons. Microinjection of increasing concentrations of U-II into nucleus ambiguus elicits dose-dependent bradycardia in conscious rats, indicating the in vivo activation of the cholinergic pathway controlling the heart rate. Both the in vitro and in vivo effects were abolished by the urotensin receptor antagonist, urantide. Our findings suggest that, in addition, to the previously reported increase in sympathetic outflow, U-II activates cardiac vagal neurons of nucleus ambiguus, which may contribute to cardioprotection. © 2014 International Society for Neurochemistry.

Dynamic changes in parent affect and adolescent cardiac vagal regulation: a real-time analysis.

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Cui, Lixian; Morris, Amanda Sheffield; Harrist, Amanda W; Larzelere, Robert E; Criss, Michael M

2015-04-01

The current study explored the role of parents' negative and positive affect in adolescent respiratory sinus arrhythmia (RSA) reactivity during a parent-adolescent conflict discussion task and the moderating effects of adolescent sex and age. Questionnaire data were collected from 206 adolescents (10-18 years of age; M = 13.37 years) and their primary caregivers (83.3% biological mothers). Electrocardiogram and respiration data were collected from adolescents, and RSA variables were computed. Parent affect was coded during the conflict discussion task. Multilevel modeling was used to distinguish the between- and within-individual effects of parent affect on adolescent RSA. Results indicated that observed within-parent-teen dyad anger was negatively associated with adolescent RSA, controlling for previous-minute RSA level, particularly among adolescents 13 years and older. In addition, observed between-dyad positive affect was positively linked to RSA for both boys and girls when previous-minute RSA level was controlled. Within-dyad positive affect was positively related to girl's RSA only. These findings suggest that expressions of positive affect may be related to better vagal regulation (RSA increases), whereas expressions of anger may be related to poor vagal regulation (RSA decreases) during social engagement. (c) 2015 APA, all rights reserved).

The role of sympathetic nervous system in the progression of chronic kidney disease in the era of catheter based sympathetic renal denervation.

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Petras, Dimitrios; Koutroutsos, Konstantinos; Kordalis, Athanasios; Tsioufis, Costas; Stefanadis, Christodoulos

2013-08-01

The kidney has been shown to be critically involved as both trigger and target of sympathetic nervous system overactivity in both experimental and clinical studies. Renal injury and ischemia, activation of renin angiotensin system and dysfunction of nitric oxide system have been implicated in adrenergic activation from kidney. Conversely, several lines of evidence suggest that sympathetic overactivity, through functional and morphological alterations in renal physiology and structure, may contribute to kidney injury and chronic kidney disease progression. Pharmacologic modulation of sympathetic nervous system activity has been found to have a blood pressure independent renoprotective effect. The inadequate normalization of sympathoexcitation by pharmacologic treatment asks for novel treatment options. Catheter based renal denervation targets selectively both efferent and afferent renal nerves and functionally denervates the kidney providing blood pressure reduction in clinical trials and renoprotection in experimental models by ameliorating the effects of excessive renal sympathetic drive. This review will focus on the role of sympathetic overactivity in the pathogenesis of kidney injury and CKD progression and will speculate on the effect of renal denervation to these conditions.

Low vagally-mediated heart rate variability and increased susceptibility to ventricular arrhythmias in rats bred for high anxiety.

Science.gov (United States)

Carnevali, Luca; Trombini, Mimosa; Graiani, Gallia; Madeddu, Denise; Quaini, Federico; Landgraf, Rainer; Neumann, Inga D; Nalivaiko, Eugene; Sgoifo, Andrea

2014-04-10

In humans, there is a documented association between anxiety disorders and cardiovascular disease. Putative underlying mechanisms may include an impairment of the autonomic nervous system control of cardiac function. The primary objective of the present study was to characterize cardiac autonomic modulation and susceptibility to arrhythmias in genetic lines of rats that differ largely in their anxiety level. To reach this goal, electrocardiographic recordings were performed in high-anxiety behavior (HAB, n=10) and low-anxiety behavior (LAB, n=10) rats at rest, during stressful stimuli and under autonomic pharmacological manipulations, and analyzed by means of time- and frequency-domain indexes of heart rate variability. During resting conditions, HAB rats displayed a reduced heart rate variability, mostly in terms of lower parasympathetic (vagal) modulation compared to LAB rats. In HAB rats, this relatively low cardiac vagal control was associated with smaller heart rate responsiveness to acute stressors compared to LAB counterparts. In addition, beta-adrenergic pharmacological stimulation induced a larger incidence of ventricular tachyarrhythmias in HABs compared to LABs. At sacrifice, a moderate increase in heart-body weight ratio was observed in HAB rats. We conclude that high levels of anxiety-related behavior in rats are associated with signs of i) impaired autonomic modulation of heart rate (low vagally-mediated heart rate variability), ii) poor adaptive heart rate responsiveness to stressful stimuli, iii) increased arrhythmia susceptibility, and iv) cardiac hypertrophy. These results highlight the utility of the HAB/LAB model for investigating the mechanistic basis of the comorbidity between anxiety disorders and cardiovascular disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Ventricular tachyarrhythmia-related basal cardiomyopathy in rabbits with vagal stimulation--a novel experimental model for inverted Takotsubo-like cardiomyopathy.

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Takato, Tetsuya; Ashida, Terunao; Seko, Yoshinori; Fujii, Jun; Kawai, Sachio

2010-07-01

Electrical stimulation of the intact (unsectioned) cervical vagus in rabbits frequently provokes ventricular tachyarrhythmias that are often accompanied by mitral regurgitation. Unique pathological lesions often arise on the mitral valve, papillary muscles, and mitral annulus (mitral complex), the latter two of which become swollen and stiffened. These lesions are reversible in nature. Previous studies have essentially ignored the basal portion except for the mitral annulus. Therefore, the present study examined pathological lesions on the left ventricular basal portion in rabbits. The intact right vagal nerves of 20 anesthetized rabbits were repeatedly electrically stimulated under electrocardiographic monitoring. Colloidal carbon (lml) was injected intravenously immediately after the end of the stimulation and all animals were killed 1 week later. Pathological lesions were identified as carbon deposits visible at gross examination. Ventricular bigeminy was induced after vagal stimulation in 15 (75%) of the 20 rabbits. Pathological lesions were evident on the basal portion in 16 (80%) and on the mitral valve and papillary muscles of 15 (75%) of the 20 rabbits. Ventricular bigeminy was closely associated with the development of the pathological lesions, which were rarely observed on the ventricular apex. Cardiomyopathic lesions involving the basal portion and mitral complex were frequently induced in rabbits by vagal stimulation. These lesions bear a close similarity in distribution and reversibility to inverted Takotsubo cardiomyopathy. Copyright 2010 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Effects of renal sympathetic denervation on cardiac sympathetic activity and function in patients with therapy resistant hypertension

NARCIS (Netherlands)

van Brussel, Peter M.; Eeftinck Schattenkerk, Daan W.; Dobrowolski, Linn C.; de Winter, Robbert J.; Reekers, Jim A.; Verberne, Hein J.; Vogt, Liffert; van den Born, Bert-Jan H.

2016-01-01

Renal sympathetic denervation (RSD) is currently being investigated in multiple studies of sympathetically driven cardiovascular diseases such as heart failure and arrhythmias. Our aim was to assess systemic and cardiac sympatholytic effects of RSD by the measurement of cardiac sympathetic activity

First-in-Man Experience with a Novel Catheter-Based Renal Denervation System of Ultrasonic Ablation in Patients with Resistant Hypertension.

Science.gov (United States)

Chernin, Gil; Szwarcfiter, Iris; Scheinert, Dierk; Blessing, Erwin; Diehm, Nicolas; Dens, Jo; Walton, Antony; Verheye, Stefan; Shetty, Sharad; Jonas, Michael

2018-06-16

To report results of renal denervation (RDN) with the first catheter-based, non-balloon occlusion ultrasonic system in patients with resistant hypertension. In a multicenter, single-arm trial, 39 patients with resistant hypertension (defined as uncontrolled hypertension while taking ≥ 3 antihypertensive medications) were treated. The cohort consisted of 4 groups: severe resistant hypertension (office systolic blood pressure [OSBP] ≥ 160 mm Hg) treated with a unidirectional catheter (group 1; n = 14); severe resistant hypertension treated with a multidirectional catheter (group 2; n = 18); moderate resistant hypertension (OSBP 140-159 mm Hg) treated with a multidirectional catheter (group 3; n = 5); and recurrent severe resistant hypertension, after an initial response to RF RDN (group 4; n = 2). Blood pressure monitoring was performed for 6 months. Severe adverse events were not noted immediately after the procedure or during follow-up. Treatment time was longer with unidirectional than with multidirectional catheters (36.7 min ± 9.6 vs 11.9 min ± 5.8; P < .001). Mean reductions in office blood pressure (systolic/diastolic) at 1, 3, and 6 months were -26.1/-9.6 mm Hg, -28.0/-9.9 mm Hg, and -30.6/-14.1 mm Hg (P < .01 for all). Per-group analysis showed significant OSBP reduction for groups 1 and 2. Patients with isolated systolic hypertension had a significantly smaller reduction in OSBP after 6 months compared with patients with combined systolic/diastolic hypertension (-16.2 mm Hg ± 18.5 vs -9.9 mm Hg ± 33.4; P < .005). Use of the RDN system was feasible and safe in this phase I study. Significant blood pressure reductions were observed over 6 months, although less in patients with isolated systolic hypertension. Copyright © 2018 SIR. All rights reserved.

Percutaneous thermal ablation of renal neoplasms

International Nuclear Information System (INIS)

Tacke, J.; Mahnken, A.H.; Guenther, R.W.

2005-01-01

Due to modern examination techniques such as multidetector computed tomography and high-field magnetic resonance imaging, the detection rate of renal neoplasms is continually increasing. Even though tumors exceeding 4 cm in diameter rarely metastasize, all renal lesions that are possible neoplasms should be treated. Traditional treatment techniques include radical nephrectomy or nephron-sparing resection, which are increasingly performed laparoscopically. Modern thermal ablation techniques such as hyperthermal techniques like radiofrequency ablation RFA, laser induced thermal ablation LITT, focused ultrasound FUS and microwave therapy MW, as well as hypothermal techniques (cryotherapy) may be a useful treatment option for patients who are unfit for or refuse surgical resection. Cryotherapy is the oldest and best known thermal ablation technique and can be performed laparoscopically or percutaneously. Since subzero temperatures have no antistyptic effect, additional maneuvers must be performed to control bleeding. Percutaneous cryotherapy of renal tumors is a new and interesting method, but experience with it is still limited. Radiofrequency ablation is the most frequently used method. Modern probe design allows volumes between 2 and 5 cm in diameter to be ablated. Due to hyperthermal tract ablation, the procedure is deemed to be safe and has a low complication rate. Although there are no randomized comparative studies to open resection, the preliminary results for renal RFA are promising and show RFA to be superior to other thermal ablation techniques. Clinical success rates are over 90% for both, cryo- and radiofrequency ablation. Whereas laser induced thermal therapy is established in hepatic ablation, experience is minimal with respect to renal application. For lesions of more than 2 cm in diameter, additional cooling catheters are required. MR thermometry offers temperature control during ablation. Microwave ablation is characterized by small ablation volumes

Intrinsic denervation of the colon is associated with a decrease of some colonic preneoplastic markers in rats treated with a chemical carcinogen

Directory of Open Access Journals (Sweden)

M.V.O. Vespúcio

2008-04-01

Full Text Available Denervation of the colon is protective against the colon cancer; however, the mechanisms involved are unknown. We tested the hypothesis that the denervated colonic mucosa could be less responsive to the action of the chemical carcinogen dimethylhydrazine (DMH. Three groups of 32 male Wistar rats were treated as follows: group 1 (G1 had the colon denervated with 0.3 mL 1.5 mM benzyldimethyltetradecylammonium (benzalkonium chloride, BAC; G2 received a single ip injection of 125 mg/kg DMH; G3 was treated with BAC + the same dose and route of DMH. A control group (Sham, N = 32 did not receive any treatment. Each group was subdivided into four groups according to the sacrifice time (1, 2, 6, and 12 weeks after DMH. Crypt fission index, ß-catenin accumulated crypts, aberrant crypt foci, and cell proliferation were evaluated and analyzed by ANOVA and the Student t-test. G3 animals presented a small number of aberrant crypt foci and low crypt fission index compared to G2 animals after 2 and 12 weeks, respectively. From the second week on, the index of ß-catenin crypt in G3 animals increased slower than in G2 animals. From the 12th week on, G2 animals presented a significant increase in cell proliferation when compared to the other groups. Colonic denervation plays an anticarcinogenic role from early stages of colon cancer development. This finding can be of importance for the study of the role of the enteric nervous system in the carcinogenic process.

Laboratory Simulations of Micrometeoroid Ablation

Science.gov (United States)

Thomas, Evan Williamson

Each day, several tons of meteoric material enters Earth's atmosphere, the majority of which consist of small dust particles (micrometeoroids) that completely ablate at high altitudes. The dust input has been suggested to play a role in a variety of phenomena including: layers of metal atoms and ions, nucleation of noctilucent clouds, effects on stratospheric aerosols and ozone chemistry, and the fertilization of the ocean with bio-available iron. Furthermore, a correct understanding of the dust input to the Earth provides constraints on inner solar system dust models. Various methods are used to measure the dust input to the Earth including satellite detectors, radar, lidar, rocket-borne detectors, ice core and deep-sea sediment analysis. However, the best way to interpret each of these measurements is uncertain, which leads to large uncertainties in the total dust input. To better understand the ablation process, and thereby reduce uncertainties in micrometeoroid ablation measurements, a facility has been developed to simulate the ablation of micrometeoroids in laboratory conditions. An electrostatic dust accelerator is used to accelerate iron particles to relevant meteoric velocities (10-70 km/s). The particles are then introduced into a chamber pressurized with a target gas, and they partially or completely ablate over a short distance. An array of diagnostics then measure, with timing and spatial resolution, the charge and light that is generated in the ablation process. In this thesis, we present results from the newly developed ablation facility. The ionization coefficient, an important parameter for interpreting meteor radar measurements, is measured for various target gases. Furthermore, experimental ablation measurements are compared to predictions from commonly used ablation models. In light of these measurements, implications to the broader context of meteor ablation are discussed.

Foot reflexology can increase vagal modulation, decrease sympathetic modulation, and lower blood pressure in healthy subjects and patients with coronary artery disease.

Science.gov (United States)

Lu, Wan-An; Chen, Gau-Yang; Kuo, Cheng-Deng

2011-01-01

Complementary and alternative medicine (CAM) has long been used by people to postpone the aging process and to reverse disease progression. Reflexology is a CAM method that involves massage to reflex areas in the feet and hands. This study investigated the effect of foot reflexology (FR) on the autonomic nervous modulation in patients with coronary artery disease (CAD) by using heart rate variability analysis. Seventeen people with angiographically patent coronary arteries and 20 patients with CAD scheduled for coronary artery bypass graft surgery were recruited as the control and CAD groups, respectively. The normalized high-frequency power (nHFP) was used as the index of vagal modulation and the normalized very low-frequency power (nVLFP) as the index of vagal withdrawal and renin-angiotensin modulation. In both control and CAD groups, the nHFP was increased significantly whereas the nVLFP was decreased significantly 30 and 60 minutes after FR, as compared with those before FR. The systolic, diastolic, mean arterial, and pulse pressures were significantly decreased after FR in both groups of participants. In the CAD group, the percentage change in heart rate 30 and 60 minutes after FR was smaller than that in the control, and the percentage change in nVLFP 60 minutes after FR was smaller than that in the control. In conclusion, a higher vagal modulation, lower sympathetic modulation, and lower blood pressure can be observed following 60 minutes of FR in both controls and CAD patients. The magnitude of change in the autonomic nervous modulation in CAD patients was slightly smaller than that in the controls. FR may be used as an efficient adjunct to the therapeutic regimen to increase the vagal modulation and decrease blood pressure in both healthy people and CAD patients.

Abdominal Aortic Calcifications Influences the Systemic and Renal Hemodynamic Response to Renal Denervation in the DENERHTN (Renal Denervation for Hypertension) Trial.

Science.gov (United States)

Courand, Pierre-Yves; Pereira, Helena; Del Giudice, Costantino; Gosse, Philippe; Monge, Matthieu; Bobrie, Guillaume; Delsart, Pascal; Mounier-Vehier, Claire; Lantelme, Pierre; Denolle, Thierry; Dourmap, Caroline; Halimi, Jean Michel; Girerd, Xavier; Rossignol, Patrick; Zannad, Faiez; Ormezzano, Olivier; Vaisse, Bernard; Herpin, Daniel; Ribstein, Jean; Bouhanick, Beatrice; Mourad, Jean-Jacques; Ferrari, Emile; Chatellier, Gilles; Sapoval, Marc; Azarine, Arshid; Azizi, Michel

2017-10-10

The DENERHTN (Renal Denervation for Hypertension) trial confirmed the efficacy of renal denervation (RDN) in lowering daytime ambulatory systolic blood pressure when added to standardized stepped-care antihypertensive treatment (SSAHT) for resistant hypertension at 6 months. This post hoc exploratory analysis assessed the impact of abdominal aortic calcifications (AAC) on the hemodynamic and renal response to RDN at 6 months. In total, 106 patients with resistant hypertension were randomly assigned to RDN plus SSAHT or to the same SSAHT alone (control group). Total AAC volume was measured, with semiautomatic software and blind to randomization, from the aortic hiatus to the iliac bifurcation using the prerandomization noncontrast abdominal computed tomography scans of 90 patients. Measurements were expressed as tertiles. The baseline-adjusted difference in the change in daytime ambulatory systolic blood pressure from baseline to 6 months between the RDN and control groups was -10.1 mm Hg ( P =0.0462) in the lowest tertile and -2.5 mm Hg ( P =0.4987) in the 2 highest tertiles of AAC volume. Estimated glomerular filtration rate remained stable at 6 months for the patients in the lowest tertile of AAC volume who underwent RDN (+2.5 mL/min per 1.73 m 2 ) but decreased in the control group (-8.0 mL/min per 1.73 m 2 , P =0.0148). In the 2 highest tertiles of AAC volume, estimated glomerular filtration rate decreased similarly in the RDN and control groups ( P =0.2640). RDN plus SSAHT resulted in a larger decrease in daytime ambulatory systolic blood pressure than SSAHT alone in patients with a lower AAC burden than in those with a higher AAC burden. This larger decrease in daytime ambulatory systolic blood pressure was not associated with a decrease in estimated glomerular filtration rate. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01570777. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Neural control of left ventricular contractility in the dog heart: synaptic interactions of negative inotropic vagal preganglionic neurons in the nucleus ambiguus with tyrosine hydroxylase immunoreactive terminals.

Science.gov (United States)

Massari, V J; Dickerson, L W; Gray, A L; Lauenstein, J M; Blinder, K J; Newsome, J T; Rodak, D J; Fleming, T J; Gatti, P J; Gillis, R A

1998-08-17

Recent physiological evidence indicates that vagal postganglionic control of left ventricular contractility is mediated by neurons found in a ventricular epicardial fat pad ganglion. In the dog this region has been referred to as the cranial medial ventricular (CMV) ganglion [J.L. Ardell, Structure and function of mammalian intrinsic cardiac neurons, in: J.A. Armour, J.L. Ardell (Eds.). Neurocardiology, Oxford Univ. Press, New York, 1994, pp. 95-114; B.X. Yuan, J.L. Ardell, D.A. Hopkins, A.M. Losier, J.A. Armour, Gross and microscopic anatomy of the canine intrinsic cardiac nervous system, Anat. Rec., 239 (1994) 75-87]. Since activation of the vagal neuronal input to the CMV ganglion reduces left ventricular contractility without influencing cardiac rate or AV conduction, this ganglion contains a functionally selective pool of negative inotropic parasympathetic postganglionic neurons. In the present report we have defined the light microscopic distribution of preganglionic negative inotropic neurons in the CNS which are retrogradely labeled from the CMV ganglion. Some tissues were also processed for the simultaneous immunocytochemical visualization of tyrosine hydroxylase (TH: a marker for catecholaminergic neurons) and examined with both light microscopic and electron microscopic methods. Histochemically visualized neurons were observed in a long slender column in the ventrolateral nucleus ambiguus (NA-VL). The greatest number of retrogradely labeled neurons were observed just rostral to the level of the area postrema. TH perikarya and dendrites were commonly observed interspersed with vagal motoneurons in the NA-VL. TH nerve terminals formed axo-dendritic synapses upon negative inotropic vagal motoneurons, however the origin of these terminals remains to be determined. We conclude that synaptic interactions exist which would permit the parasympathetic preganglionic vagal control of left ventricular contractility to be modulated monosynaptically by

Ventricular fibrillation occurring after atrioventricular node ablation despite minimal difference between pre- and post-ablation heart rates.

Science.gov (United States)

Squara, F; Theodore, G; Scarlatti, D; Ferrari, E

2017-02-01

We report the case of an 82-year-old man presenting with ventricular fibrillation (VF) occurring acutely after atrioventricular node (AVN) ablation. This patient had severe valvular cardiomyopathy, chronic atrial fibrillation (AF), and underwent prior to the AVN ablation a biventricular implantable cardiac defibrillator positioning. The VF was successfully cardioverted with one external electrical shock. What makes this presentation original is that the pre-ablation spontaneous heart rate in AF was slow (84 bpm), and that VF occurred after ablation despite a minimal heart rate drop of only 14 bpm. VF is the most feared complication of AVN ablation, but it had previously only been described in case of acute heart rate drop after ablation of at least 30 bpm (and more frequently>50 bpm). This case report highlights the fact that VF may occur after AVN ablation regardless of the heart rate drop, rendering temporary fast ventricular pacing mandatory whatever the pre-ablation heart rate. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The morphological substrate for Renal Denervation : Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study

NARCIS (Netherlands)

van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

2015-01-01

BACKGROUND: Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of

Thermal Ablation of T1c Renal Cell Carcinoma: A Comparative Assessment of Technical Performance, Procedural Outcome, and Safety of Microwave Ablation, Radiofrequency Ablation, and Cryoablation.

Science.gov (United States)

Zhou, Wenhui; Arellano, Ronald S

2018-04-06

To evaluate perioperative outcomes of thermal ablation with microwave (MW), radiofrequency (RF), and cryoablation for stage T1c renal cell carcinoma (RCC). A retrospective analysis of 384 patients (mean age, 71 y; range, 22-88 y) was performed between October 2006 and October 2016. Mean radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines; preoperative aspects and dimensions used for anatomic classification; and centrality index scores were 6.3, 7.9, and 2.7, respectively. Assessment of pre- and postablation serum blood urea nitrogen, creatinine, and estimated glomerular filtration rate was performed to assess functional outcomes. Linear regression analyses were performed to compare sedation medication dosages among the three treatment cohorts. Univariable and multivariable logistic regression analyses were performed to compare rates of residual disease and complications among treatment modalities. A total of 437 clinical stage T1N0M0 biopsy-proven RCCs measuring 1.2-6.9 cm were treated with computed tomography (CT)-guided MW ablation (n = 44; 10%), RF ablation (n = 347; 79%), or cryoablation (n = 46; 11%). There were no significant differences in patient demographic or tumor characteristics among cohorts. Complication rates and immediate renal function changes were similar among the three ablation modalities (P = .46 and P = .08, respectively). MW ablation was associated with significantly decreased ablation time (P < .05), procedural time (P < .05), and dosage of sedative medication (P < .05) compared with RF ablation and cryoablation. CT-guided percutaneous MW ablation is comparable to RF ablation or cryoablation for the treatment of stage T1N0M0 RCC with regard to treatment response and is associated with shorter treatment times and less sedation than RF ablation or cryoablation. In addition, the safety profile of CT-guided MW ablation is noninferior to those of RF ablation or

[Comparison of efficacy between continuous positive airway pressure and renal artery sympathetic denervation by radiofrequency ablation in obstructive sleep apnea syndrome patients with hypertension].

Science.gov (United States)

Zhao, Meng-meng; Tan, Xue-xue; Ding, Ning; Zhang, Xi-long

2013-04-23

To compare the efficacy of renal arterial sympathetic denervation (RSD) and continuous positive airway pressure (CPAP) in patients with coexisting moderate-to-severe obstructive sleep apnea syndrome (OSAS) and hypertension. Retrospective analysis was conducted for patients with coexisting moderate to severe OSAS and hypertension for the efficacy of RSD (RSD group, n = 15) and CPAP (CPAP group, n = 16). Comparison was made for polysomnographic parameters and 24 hours ambulatory blood pressure (Bp) between two groups. There was no significant difference in age, gender, body mass index, nocturnal apnea hypopnea index (AHI), mean and minimal pulse oxygen saturation (mean SpO2 and mini SpO2) between two groups. Compared with those at pre-treatment, the following changes were observed at Day 30 post-treatment: in RSD group, the nocturnal AHI and T90 statistically decreased (27 ± 14 vs 32 ± 12, 8.7% ± 7.8% vs 13.8% ± 13.1%, all P 0.05); in CPAP group during treatment, nocturnal AHI and the ratio of duration SpO2 hypertension, both RSD and CPAP may improve sleep respiratory parameters and blood pressure to varying degrees. There is a more significant improvement of nocturnal AHI and SpO2 in CPAP group and more lower MSBp in RSD group.

Perioral Rejuvenation With Ablative Erbium Resurfacing.

Science.gov (United States)

Cohen, Joel L

2015-11-01

Since the introduction of the scanning full-field erbium laser, misconceptions regarding ablative erbium resurfacing have resulted in its being largely overshadowed by ablative fractional resurfacing. This case report illustrates the appropriateness of full-field erbium ablation for perioral resurfacing. A patient with profoundly severe perioral photodamage etched-in lines underwent full-field ablative perioral resurfacing with an erbium laser (Contour TRL, Sciton Inc., Palo Alto, CA) that allows separate control of ablation and coagulation. The pre-procedure consultations included evaluation of the severity of etched-in lines, and discussion of patient goals, expectations, and appropriate treatment options, as well as a review of patient photos and post-treatment care required. The author generally avoids full-field erbium ablation in patients with Fitzpatrick type IV and above. For each of 2 treatment sessions (separated by approximately 4 months), the patient received (12 cc plain 2% lidodaine) sulcus blocks before undergoing 4 passes with the erbium laser at 150 μ ablation, no coagulation, and then some very focal 30 μ ablation to areas of residual lines still visualized through the pinpoint bleeding. Similarly, full-field ablative resurfacing can be very reliable for significant wrinkles and creping in the lower eyelid skin--where often a single treatment of 80 μ ablation, 50 μ coagulation can lead to a nice improvement. Standardized digital imaging revealed significant improvement in deeply etched rhytides without significant adverse events. For appropriately selected patients requiring perioral (or periorbital) rejuvenation, full-field ablative erbium resurfacing is safe, efficacious and merits consideration.

Minimally Invasive Sacroiliac Joint Fusion, Radiofrequency Denervation, and Conservative Management for Sacroiliac Joint Pain: 6-Year Comparative Case Series.

Science.gov (United States)

Vanaclocha, Vicente; Herrera, Juan Manuel; Sáiz-Sapena, Nieves; Rivera-Paz, Marlon; Verdú-López, Francisco

2018-01-01

Sacroiliac joint (SIJ) pain is an under-recognized condition. Substantial information supports the safety and effectiveness of SIJ fusion (SIJF). Long-term follow-up after SIJF has not been reported. To determine responses to conservative management (CM), SIJ denervation, and SIJF in patients with SIJ pain unresponsive to CM. Retrospective study with long-term (up to 6 yr) follow-up of 137 patients with SIJ pain seen in an outpatient neurosurgery clinic who received either CM (n = 63), sacroiliac denervation (n = 47), or minimally invasive SIJF (n = 27). At each routine clinic visit, patients completed pain scores and Oswestry Disability Index. Additional data were extracted from medical charts. Patients treated with continued CM had no long-term improvement in pain (mean worsening of 1 point) or disability (mean Oswestry Disability Index worsened by 4-6 points), increased their use of opioids, and had poor long-term work status. SIJF patients had large improvements in SIJ pain (mean 6 points), large improvements in disability (mean 25 points), a decrease in opioid use, and good final work status. Sacroiliac denervation patients had intermediate responses (0-1 and 1-2 points, respectively). In patients with SIJ pain unresponsive to CM, SIJF resulted in excellent long-term clinical responses, with low opioid use and better work status compared to other treatments. Copyright © 2017 by the Congress of Neurological Surgeons

Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia.

Science.gov (United States)

Shin, Mi-Kyung; Yao, Qiaoling; Jun, Jonathan C; Bevans-Fonti, Shannon; Yoo, Doo-Young; Han, Woobum; Mesarwi, Omar; Richardson, Ria; Fu, Ya-Yuan; Pasricha, Pankaj J; Schwartz, Alan R; Shirahata, Machiko; Polotsky, Vsevolod Y

2014-10-01

Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.-9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity. Copyright © 2014 the American Physiological Society.

CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results

Energy Technology Data Exchange (ETDEWEB)

Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Lemm, G.; Hohenstein, E. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany); Bellemann, N.; Stampfl, U. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Goezen, A. S.; Rassweiler, J. [Clinic for Urology, SLK Kliniken Heilbronn GmbH (Germany); Kauczor, H. U.; Radeleff, B. A. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Pereira, P. L. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany)

2013-06-15

Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 {+-} 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 {+-} 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 {+-} 13.6 min and 43.7 {+-} 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 {+-} 8.8 months, local recurrence-free survival was 14.4 {+-} 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 {+-} 16.6 ml/min/1.73 m{sup 2} before RF ablation vs. 47.2 {+-} 11.9 ml/min/1.73 m{sup 2} after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Acute physiological and electrical accentuation of vagal tone has no effect on pain or gastrointestinal motility in chronic pancreatitis

DEFF Research Database (Denmark)

Juel, Jacob; Brock, Christina; Olesen, Soren S.

2017-01-01

derived parameters of autonomic tone, quantitative sensory testing of bone and muscle pain pressure, conditioned pain modulation (CPM) and assessments of gastroduodenal motility with ultrasound were performed. Results: In comparison to sham, t-VNS and DSB increased cardiac vagal tone (CVT) (P

Interactions Between Epinephrine, Ascending Vagal Fibers and Central Noradrenergic Systems in Modulating Memory for Emotionally Arousing Events.

Directory of Open Access Journals (Sweden)

Cedric L. Williams

2012-06-01

Full Text Available It is well established that exposure to emotionally laden events initiates secretion of the arousal related hormone epinephrine in the periphery. These neuroendocrine changes and the subsequent increase in peripheral physiological output play an integral role in modulating brain systems involved in memory formation. The impermeability of the blood brain barrier to epinephrine represents an important obstacle in understanding how peripheral hormones initiate neurochemical changes in the brain that lead to effective memory formation. This obstacle necessitated the identity of a putative pathway capable of conveying physiological changes produced by epinephrine to limbic structures that incorporate arousal and affect related information into memory. A major theme of the proposed studies is that ascending fibers of the vagus nerve may represent such a mechanism. This hypothesis was tested by evaluating the contribution of ascending vagal fibers in modulating memory for responses learned under behavioral conditions that produce emotional arousal by manipulating appetitive stimuli. A combination of electrophysiological recording of vagal afferent fibers and in vivo microdialysis was employed in a second study to simultaneously assess how elevations in peripheral levels of epinephrine affect vagal nerve discharge and the subsequent potentiation of norepinephrine release in the basolateral amygdala. The final study used double immunohistochemistry labeling of c-fos and dopamine beta hydroxylase, the enzyme for norepinephrine synthesis to determine if epinephrine administration alone or stimulation of the vagus nerve at an intensity identical to that which improved memory in Experiment 1 produces similar patterns of neuronal activity in brain areas involved in processing memory for emotional events. Findings emerging from this collection of studies establish the importance of ascending fibers of the vagus nerve as an essential pathway for conveying the

Water spray assisted ultrashort laser pulse ablation

International Nuclear Information System (INIS)

Silvennoinen, M.; Kaakkunen, J.J.J.; Paivasaari, K.; Vahimaa, P.

2013-01-01

Highlights: ► We show the novel method to use multibeam processing with ultrashort pulses efficiently. ► Sprayed thin water layer on ablation zone enhances ablation rate and quality. ► In some cases this method also enables ablation of the deeper and straighter holes compared to ones made without the water layer. ► Method also makes possible to directly write features without the self-organizing structures. - Abstract: We have studied femtosecond ablation under sprayed thin water film and its influence and benefits compared with ablation in the air atmosphere. These have been studied in case of the hole and the groove ablation using IR femtosecond laser. Water enhances the ablation rate and in some situations it makes possible to ablate the holes with a higher aspect ratio. While ablating the grooves, the water spray allows using the high fluences without the generation of the self-organized structures.

The effect of ethanol infusion on the size of the ablated lesion in radiofrequency thermal ablation: A pilot study

International Nuclear Information System (INIS)

Kim, Young Sun; Rhim, Hyun Chul; Koh, Byung Hee; Cho, On Koo; Seo, Heung Suk; Kim, Yong Soo; Joo, Kyoung Bin

2001-01-01

To assess the effect of ethanol infusion on the size of ablated lesion during radiofrequency (RF) thermal ablation. We performed an ex vivo experimental study using a total of 15 pig livers. Three groups were designed: 1)normal control (n=10), 2) saline infusion (n=10) 3) ethanol infusion (n=10). Two radiofrequency ablations were done using a 50 watt RF generator and a 15 guage expandable elections with four prongs in each liver. During ablation for 8 minutes, continuous infusion of fluid at a rate of 0.5 ml/min through the side arm of electrode was performed. We checked the frequency of the 'impeded-out' phenomenon due to abrupt increase of impedance during ablation. Size of ablated lesion was measured according to length, width, height, and subsequently volume after the ablations. The sizes of the ablated lesions were compared between the three groups. 'Impeded-out' phenomenon during ablation was noted 4 times in control group, although that never happened in saline or ethanol infusion groups. There were significant differences in the volumes of ablated lesions between control group (10.62 ± 1.45 cm 3 ) and saline infusion group (15.33 ± 2.47 cm 3 ), and saline infusion group and ethanol infusion group (18.78 ± 3.58 cm 3 ) (p<0.05). Fluid infusion during radiofrequency thermal ablation decrease a chance of charming and increase the volume of the ablated lesion. Ethanol infusion during ablation may induce larger volume of ablated lesion than saline infusion.

Imaging of muscular denervation secondary to motor cranial nerve dysfunction

International Nuclear Information System (INIS)

Connor, S.E.J.; Chaudhary, N.; Fareedi, S.; Woo, E.K.

2006-01-01

The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality

Imaging of muscular denervation secondary to motor cranial nerve dysfunction

Energy Technology Data Exchange (ETDEWEB)

Connor, S.E.J. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom)]. E-mail: sejconnor@tiscali.co.uk; Chaudhary, N. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Fareedi, S. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Woo, E.K. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom)

2006-08-15

The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality.

Neurotransmission to parasympathetic cardiac vagal neurons in the brain stem is altered with left ventricular hypertrophy-induced heart failure.

Science.gov (United States)

Cauley, Edmund; Wang, Xin; Dyavanapalli, Jhansi; Sun, Ke; Garrott, Kara; Kuzmiak-Glancy, Sarah; Kay, Matthew W; Mendelowitz, David

2015-10-01

Hypertension, cardiac hypertrophy, and heart failure (HF) are widespread and debilitating cardiovascular diseases that affect nearly 23 million people worldwide. A distinctive hallmark of these cardiovascular diseases is autonomic imbalance, with increased sympathetic activity and decreased parasympathetic vagal tone. Recent device-based approaches, such as implantable vagal stimulators that stimulate a multitude of visceral sensory and motor fibers in the vagus nerve, are being evaluated as new therapeutic approaches for these and other diseases. However, little is known about how parasympathetic activity to the heart is altered with these diseases, and this lack of knowledge is an obstacle in the goal of devising selective interventions that can target and selectively restore parasympathetic activity to the heart. To identify the changes that occur within the brain stem to diminish the parasympathetic cardiac activity, left ventricular hypertrophy was elicited in rats by aortic pressure overload using a transaortic constriction approach. Cardiac vagal neurons (CVNs) in the brain stem that generate parasympathetic activity to the heart were identified with a retrograde tracer and studied using patch-clamp electrophysiological recordings in vitro. Animals with left cardiac hypertrophy had diminished excitation of CVNs, which was mediated both by an augmented frequency of spontaneous inhibitory GABAergic neurotransmission (with no alteration of inhibitory glycinergic activity) as well as a diminished amplitude and frequency of excitatory neurotransmission to CVNs. Opportunities to alter these network pathways and neurotransmitter receptors provide future targets of intervention in the goal to restore parasympathetic activity and autonomic balance to the heart in cardiac hypertrophy and other cardiovascular diseases. Copyright © 2015 the American Physiological Society.

Bipolar Radiofrequency Facet Ablation of the Lumbar Facet Capsule: An Adjunct to Conventional Radiofrequency Ablation for Pain Management.

Science.gov (United States)

Jacobson, Robert E; Palea, Ovidiu; Granville, Michelle

2017-09-01

Radiofrequency facet ablation (RFA) has been performed using the same technique for over 50 years. Except for variations in electrode size, tip shape, and change in radiofrequency (RF) stimulation parameters, using standard, pulsed, and cooled RF wavelengths, the target points have remained absolutely unchanged from the original work describing RFA for lumbar pain control. Degenerative changes in the facet joint and capsule are the primary location for the majority of lumbar segmental pathology and pain. Multiple studies show that the degenerated facet joint is richly innervated as a result of the inflammatory overgrowth of the synovium. The primary provocative clinical test to justify an RFA is to perform an injection with local anesthetic into the facet joint and the posterior capsule and confirm pain relief. However, after a positive response, the radiofrequency lesion is made not to the facet joint but to the more proximal fine nerve branches that innervate the joint. The accepted target points for the recurrent sensory branch ignore the characteristic rich innervation of the pathologic lumbar facet capsule and assume that lesioning of these recurrent branches is sufficient to denervate the painful pathologic facet joint. This report describes the additional targets and technical steps for further coagulation points along the posterior capsule of the lumbar facet joint and the physiologic studies of the advantage of the bipolar radiofrequency current in this location. Bipolar RF to the facet capsule is a simple, extra step that easily creates a large thermo-coagulated lesion in this capsule region of the pathologic facet joint. Early studies demonstrate bipolar RF to the facet capsule can provide long-term pain relief when used alone for specific localized facet joint pain, to coagulate lumbar facet cysts to prevent recurrence, and to get more extensive pain control by combining it with traditional lumbar RFA, especially when RFA is repeated.

Ablation of Solid Hydrogen in a Plasma

DEFF Research Database (Denmark)

Jørgensen, L. W.; Sillesen, Alfred Hegaard

1979-01-01

Several hydrogen pellet ablation models based on the formation of a shielding neutral cloud have been reported by different authors. The predicted ablation rates are shown to follow almost the same scaling law and this is used to explain the authors' ablation experiment.......Several hydrogen pellet ablation models based on the formation of a shielding neutral cloud have been reported by different authors. The predicted ablation rates are shown to follow almost the same scaling law and this is used to explain the authors' ablation experiment....

CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results

International Nuclear Information System (INIS)

Sommer, C. M.; Lemm, G.; Hohenstein, E.; Bellemann, N.; Stampfl, U.; Goezen, A. S.; Rassweiler, J.; Kauczor, H. U.; Radeleff, B. A.; Pereira, P. L.

2013-01-01

Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 ± 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 ± 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 ± 13.6 min and 43.7 ± 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 ± 8.8 months, local recurrence-free survival was 14.4 ± 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 ± 16.6 ml/min/1.73 m 2 before RF ablation vs. 47.2 ± 11.9 ml/min/1.73 m 2 after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Influence of ablation wavelength and time on optical properties of laser ablated carbon dots

Science.gov (United States)

Isnaeni, Hanna, M. Yusrul; Pambudi, A. A.; Murdaka, F. H.

2017-01-01

Carbon dots, which are unique and applicable materials, have been produced using many techniques. In this work, we have fabricated carbon dots made of coconut fiber using laser ablation technique. The purpose of this work is to evaluate two ablation parameters, which are ablation wavelength and ablation time. We used pulsed laser from Nd:YAG laser with emit wavelength at 355 nm, 532 nm and 1064 nm. We varied ablation time one hour and two hours. Photoluminescence and time-resolved photoluminescence setup were used to study the optical properties of fabricated carbon dots. In general, fabricated carbon dots emit bluish green color emission upon excitation by blue laser. We found that carbon dots fabricated using 1064 nm laser produced the highest carbon dots emission among other samples. The peak wavelength of carbon dots emission is between 495 nm until 505 nm, which gives bluish green color emission. Two hours fabricated carbon dots gave four times higher emission than one hour fabricated carbon dot. More emission intensity of carbon dots means more carbon dots nanoparticles were fabricated during laser ablation process. In addition, we also measured electron dynamics of carbon dots using time-resolved photoluminescence. We found that sample with higher emission has longer electron decay time. Our finding gives optimum condition of carbon dots fabrication from coconut fiber using laser ablation technique. Moreover, fabricated carbon dots are non-toxic nanoparticles that can be applied for health, bio-tagging and medical applications.

Investigation of different liquid media and ablation times on pulsed laser ablation synthesis of aluminum nanoparticles

International Nuclear Information System (INIS)

Baladi, Arash; Sarraf Mamoory, Rasoul

2010-01-01

Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol, acetone, and ethylene glycol. Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM) images, Particle size distribution diagram from Laser Particle Size Analyzer (LPSA), UV-visible absorption spectra, and weight changes of targets were used for the characterization and comparison of products. The experiments demonstrated that ablation efficiency in ethylene glycol is too low, in ethanol is higher, and in acetone is highest. Comparison between ethanol and acetone clarified that acetone medium leads to finer nanoparticles (mean diameter of 30 nm) with narrower size distribution (from 10 to 100 nm). However, thin carbon layer coats some of them, which was not observed in ethanol medium. It was also revealed that higher ablation time resulted in higher ablated mass, but lower ablation rate. Finer nanoparticles, moreover, were synthesized in higher ablation times.

Investigation of different liquid media and ablation times on pulsed laser ablation synthesis of aluminum nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Baladi, Arash [Materials Engineering Department, Tarbiat Modares University, Jalal Al Ahmad, P.O. Box 14115-143, Tehran (Iran, Islamic Republic of); Sarraf Mamoory, Rasoul, E-mail: rsarrafm@modares.ac.ir [Materials Engineering Department, Tarbiat Modares University, Jalal Al Ahmad, P.O. Box 14115-143, Tehran (Iran, Islamic Republic of)

2010-10-01

Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol, acetone, and ethylene glycol. Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM) images, Particle size distribution diagram from Laser Particle Size Analyzer (LPSA), UV-visible absorption spectra, and weight changes of targets were used for the characterization and comparison of products. The experiments demonstrated that ablation efficiency in ethylene glycol is too low, in ethanol is higher, and in acetone is highest. Comparison between ethanol and acetone clarified that acetone medium leads to finer nanoparticles (mean diameter of 30 nm) with narrower size distribution (from 10 to 100 nm). However, thin carbon layer coats some of them, which was not observed in ethanol medium. It was also revealed that higher ablation time resulted in higher ablated mass, but lower ablation rate. Finer nanoparticles, moreover, were synthesized in higher ablation times.

Percutaneous Renal Tumor Ablation: Radiation Exposure During Cryoablation and Radiofrequency Ablation

Energy Technology Data Exchange (ETDEWEB)

McEachen, James C., E-mail: james.mceachen2@gmail.com [Mayo Clinic, Division of Preventive, Occupational, and Aerospace Medicine (United States); Leng, Shuai; Atwell, Thomas D. [Mayo Clinic, Department of Radiology (United States); Tollefson, Matthew K. [Mayo Clinic, Department of Urology (United States); Friese, Jeremy L. [Mayo Clinic, Department of Radiology (United States); Wang, Zhen; Murad, M. Hassan [Mayo Clinic, Division of Preventive, Occupational, and Aerospace Medicine (United States); Schmit, Grant D. [Mayo Clinic, Department of Radiology (United States)

2016-02-15

IntroductionOnce reserved solely for non-surgical cases, percutaneous ablation is becoming an increasingly popular treatment option for a wider array of patients with small renal masses and the radiation risk needs to be better defined as this transition continues.Materials and MethodsRetrospective review of our renal tumor ablation database revealed 425 patients who underwent percutaneous ablation for treatment of 455 renal tumors over a 5-year time period. Imparted radiation dose information was reviewed for each procedure and converted to effective patient dose and skin dose using established techniques. Statistical analysis was performed with each ablative technique.ResultsFor the 331 cryoablation procedures, the mean DLP was 6987 mGycm (SD = 2861) resulting in a mean effective dose of 104.7 mSv (SD = 43.5) and the mean CTDI{sub vol} was 558 mGy (SD = 439) resulting in a mean skin dose of 563.2 mGy (SD = 344.1). For the 124 RFA procedures, the mean DLP was 3485 mGycm (SD = 1630) resulting in a mean effective dose of 50.3 mSv (SD = 24.0) and the mean CTDI{sub vol} was 232 mGy (SD = 149) resulting in a mean skin dose of 233.2 mGy (SD = 117.4). The difference in patient radiation exposure between the two renal ablation techniques was statistically significant (p < 0.001).ConclusionBoth cryoablation and RFA imparted an average skin dose that was well below the 2 Gy deterministic threshold for appreciable sequela. Renal tumor cryoablation resulted in a mean skin and effective radiation dose more than twice that for RFA. The radiation exposure for both renal tumor ablation techniques was at the high end of the medical imaging radiation dose spectrum.

Implantable microencapsulated dopamine (DA): prolonged functional release of DA in denervated striatal tissue.

Science.gov (United States)

McRae, A; Hjorth, S; Mason, D; Dillon, L; Tice, T

1990-01-01

Biodegradable controlled-release microcapsule systems made with the biocompatible biodegradable polyester excipient poly [DL-lactide-co-gly-colide] constitute an exciting new technology for drug delivery to the central nervous system (CNS). The present study describes functional observations indicating that implantation of dopamine (DA) microcapsules encapsulated within two different polymer excipients into denervated striatal tissue assures a prolonged release of the transmitter in vivo. This technology has a considerable potential for basic and possibly clinical research.

[Renal denervation in resistant hypertension: proposal for a common multidisciplinary attitude].

Science.gov (United States)

Muller, Olivier; Qanadli, Salah D; Waeber, Bernard; Wuerzner, Grégoire

2012-05-30

The prevalence of resistant hypertension ranges between 5-30%. Patients with resistant hypertension are at increased risk of cardiovascular events. Radiofrequency renal denervation is a recent and promising technique that can be used in the setting of resistant hypertension. However, long-term safety and efficacy data are lacking and evidence to use this procedure outside the strict setting of resistant hypertension is missing. The aim of the article is to propose a common work-up for nephrologists, hypertensiologists, cardiologists and interventional radiologists in order to avoid inappropriate selection of patients and a possible misuse of this procedure.

Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

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Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

2014-08-28

Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

International Nuclear Information System (INIS)

Pua, Uei; Tan, Cher Heng; Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong

2015-01-01

Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

Efficacy and safety of renal denervation in elderly patients with resistant hypertension.

Science.gov (United States)

Ziegler, Ann-Kathrin; Bertog, Stefan; Kaltenbach, Benjamin; Id, Dani; Franke, Jennifer; Hofmann, Ilona; Vaskelyte, Laura; Sievert, Horst

2015-08-01

Catheter-based renal sympathetic denervation (RD) causes significant blood pressure (BP) reductions in patients with resistant hypertension (rHTN). However, hypertensive elderly patients reportedly have a lower sympathetic tone than younger patients and a BP lowering effect of RD in this population has not yet been demonstrated. The purpose of this study was to assess the efficacy and safety of RD in elderly patients. We reviewed all consecutive patients aged ≥ 75 years (mean: 78 years) with rHTN treated with RD. Twenty-four patients were included in this prospective study. Office and ambulatory BPs were assessed at baseline and 6-months follow-up. Primary endpoint was the change in office systolic BP at 6 months. Baseline mean office BP was 173/86 ± 21/13 mm Hg. Baseline 24-hr mean ambulatory BP, available in 22 patients, was 158/80 ± 20/13 mm Hg. Baseline creatinine was 1.0 ± 0.18 mg/dl and mean number of antihypertensive agents at baseline 4.3 ± 1.4. No device- or procedure-related adverse events occurred. At 6-months follow-up, the mean office BP decreased by 19/11 ± 29/16 mm Hg (P renal function was not impaired. According to our findings, a similar magnitude of BP reduction as reported in previous trials can be expected in elderly patients. Elderly patients with rHTN should not be excluded from renal denervation. © 2015 Wiley Periodicals, Inc.

Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomised, sham-controlled, proof-of-concept trial.

Science.gov (United States)

Townsend, Raymond R; Mahfoud, Felix; Kandzari, David E; Kario, Kazuomi; Pocock, Stuart; Weber, Michael A; Ewen, Sebastian; Tsioufis, Konstantinos; Tousoulis, Dimitrios; Sharp, Andrew S P; Watkinson, Anthony F; Schmieder, Roland E; Schmid, Axel; Choi, James W; East, Cara; Walton, Anthony; Hopper, Ingrid; Cohen, Debbie L; Wilensky, Robert; Lee, David P; Ma, Adrian; Devireddy, Chandan M; Lea, Janice P; Lurz, Philipp C; Fengler, Karl; Davies, Justin; Chapman, Neil; Cohen, Sidney A; DeBruin, Vanessa; Fahy, Martin; Jones, Denise E; Rothman, Martin; Böhm, Michael

2017-11-11

Previous randomised renal denervation studies did not show consistent efficacy in reducing blood pressure. The objective of our study was to evaluate the effect of renal denervation on blood pressure in the absence of antihypertensive medications. SPYRAL HTN-OFF MED was a multicentre, international, single-blind, randomised, sham-controlled, proof-of-concept trial. Patients were enrolled at 21 centres in the USA, Europe, Japan, and Australia. Eligible patients were drug-naive or discontinued their antihypertensive medications. Patients with an office systolic blood pressure (SBP) of 150 mm Hg or greater and less than 180 mm Hg, office diastolic blood pressure (DBP) of 90 mm Hg or greater, and a mean 24-h ambulatory SBP of 140 mm Hg or greater and less than 170 mm Hg at second screening underwent renal angiography and were randomly assigned to renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were blinded to randomisation assignments. The primary endpoint, change in 24-h blood pressure at 3 months, was compared between groups. Drug surveillance was done to ensure patient compliance with absence of antihypertensive medication. The primary analysis was done in the intention-to-treat population. Safety events were assessed at 3 months. This study is registered with ClinicalTrials.gov, number NCT02439749. Between June 25, 2015, and Jan 30, 2017, 353 patients were screened. 80 patients were randomly assigned to renal denervation (n=38) or sham control (n=42) and followed up for 3 months. Office and 24-h ambulatory blood pressure decreased significantly from baseline to 3 months in the renal denervation group: 24-h SBP -5·5 mm Hg (95% CI -9·1 to -2·0; p=0·0031), 24-h DBP -4·8 mm Hg (-7·0 to -2·6; prenal denervation for 3-month change in both office and 24-h blood pressure from baseline: 24-h SBP -5·0 mm Hg (95% CI -9·9 to -0·2; p=0·0414), 24-h DBP -4·4 mm Hg (-7·2 to -1·6; p=0·0024), office SBP -7·7 mm Hg (-14·0

Organ damage changes in patients with resistant hypertension randomized to renal denervation or spironolactone: The DENERVHTA (Denervación en Hipertensión Arterial) study.

Science.gov (United States)

Oliveras, Anna; Armario, Pedro; Sans, Laia; Clarà, Albert; Vázquez, Susana; Molina, Luis; Pareja, Júlia; de la Sierra, Alejandro; Pascual, Julio

2018-01-01

Renal denervation and spironolactone have both been proposed for the treatment of resistant hypertension, but their effects on preclinical target organ damage have not been compared. Twenty-four patients with 24-hour systolic blood pressure ≥140 mm Hg despite receiving three or more full-dose antihypertensive drugs, one a diuretic, were randomized to receive spironolactone or renal denervation. Changes in 24-hour blood pressure, urine albumin excretion, arterial stiffness, carotid intima-media thickness, and left ventricular mass index were evaluated at 6 months. Mean baseline-adjusted difference between the two groups (spironolactone vs renal denervation) at 6 months in 24-hour systolic blood pressure was -17.9 mm Hg (95% confidence interval [CI], -30.9 to -4.9; P = .01). Mean baseline-adjusted change in urine albumin excretion was -87.2 (95% CI, -164.5 to -9.9) and -23.8 (95% CI, -104.5 to 56.9), respectively (P = .028). Mean baseline-adjusted variation of 24-hour pulse pressure was -13.5 (95% CI, -18.8 to -8.2) and -2.1 (95% CI, -7.9 to 3.7), respectively (P = .006). The correlation of change in 24-hour systolic blood pressure with change in log-transformed urine albumin excretion was r = .713 (P < .001). At 6 months there was a reduction in albuminuria in patients with resistant hypertension treated with spironolactone as compared with renal denervation. ©2018 Wiley Periodicals, Inc.

Hydrodynamic instabilities in an ablation front

International Nuclear Information System (INIS)

Piriz, A R; Portugues, R F

2004-01-01

The hydrodynamic stability of an ablation front is studied for situations in which the wavelength of the perturbations is larger than the distance to the critical surface where the driving radiation is absorbed. An analytical model is presented, and it shows that under conditions in which the thermal flux is limited within the supercritical region of the ablative corona, the front may behave like a flame or like an ablation front, depending on the perturbation wavelength. For relatively long wavelengths the critical and ablation surfaces practically lump together into a unique surface and the front behaves like a flame, whereas for the shortest wavelengths the ablation front substructure is resolved

Hydrodynamic instabilities in an ablation front

Energy Technology Data Exchange (ETDEWEB)

Piriz, A R; Portugues, R F [E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

2004-06-01

The hydrodynamic stability of an ablation front is studied for situations in which the wavelength of the perturbations is larger than the distance to the critical surface where the driving radiation is absorbed. An analytical model is presented, and it shows that under conditions in which the thermal flux is limited within the supercritical region of the ablative corona, the front may behave like a flame or like an ablation front, depending on the perturbation wavelength. For relatively long wavelengths the critical and ablation surfaces practically lump together into a unique surface and the front behaves like a flame, whereas for the shortest wavelengths the ablation front substructure is resolved.

[Renal denervation in refractory hypertension: joint statement of the German hypertension league DHL eV and the German societies of cardiology, angiology, nephrology and radiology].

Science.gov (United States)

Vonend, Oliver; Böhm, Michael; Eckert, Siegfried; Hausberg, Martin; Rittger, Harald; Rump, Lars-Christian; Schmieder, Roland; Schulte, Karl-Ludwig; Schunkert, Heribert; Uder, Michael; Veelken, Roland; Vorwerk, Dierk; Weil, Joachim; Wenzel, Ulrich; Mahfoud, Felix

2015-03-01

Arterial hypertension is a major risk factor for cardiovascular mortality and remains insufficiently controlled in Germany. The sham controlled Symplicity HTN-3 trial did meet its primary safety endpoint but failed to meet its primary efficacy endpoint. Renal denervation can not replace established, well-proven therapies. It can only be used in selected truly resistant hypertensive patients as an additive approach and should be performed by specialized centers only. Randomized controlled trials are needed to further evaluate renal denervation. © Georg Thieme Verlag KG Stuttgart · New York.

Catheter ablation of epicardial ventricular tachycardia

Directory of Open Access Journals (Sweden)

Takumi Yamada, MD, PhD

2014-08-01

Full Text Available Ventricular tachycardias (VTs can usually be treated by endocardial catheter ablation. However, some VTs can arise from the epicardial surface, and their substrate can be altered only by epicardial catheter ablation. There are two approaches to epicardial catheter ablation: transvenous and transthoracic. The transvenous approach through the coronary venous system (CVS has been commonly used because it is easily accessible. However, this approach may be limited by the distribution of the CVS and insufficient radiofrequency energy delivery. Transthoracic epicardial catheter ablation has been developed to overcome these limitations of the transvenous approach. It is a useful supplemental or even preferred strategy to eliminate epicardial VTs in the electrophysiology laboratory. This technique has been applied for scar-related VTs secondary to often non-ischemic cardiomyopathy and sometimes ischemic cardiomyopathy, and idiopathic VTs as the epicardial substrates of these VTs have become increasingly recognized. When endocardial ablation and epicardial ablation through the CVS are unsuccessful, transthoracic epicardial ablation should be the next option. Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery or pericarditis. In such cases, a hybrid procedure involving surgical access with a subxiphoid pericardial window and a limited anterior or lateral thoracotomy might be a feasible and safe method of performing an epicardial catheter ablation in the electrophysiology laboratory. Potential complications associated with this technique include bleeding and collateral damage to the coronary arteries and phrenic nerve. Although the risk of these complications is low, electrophysiologists who attempt epicardial catheter ablation should know the complications associated with this technique, how to minimize their

Loss of vagal tone aggravates systemic inflammation and cardiac impairment in endotoxemic rats.

Science.gov (United States)

Schulte, Astrid; Lichtenstern, Christoph; Henrich, Michael; Weigand, Markus A; Uhle, Florian

2014-05-15

During the course of sepsis, often myocardial depression with hemodynamic impairment occurs. Acetylcholine, the main transmitter of the parasympathetic Nervus vagus, has been shown to be of importance for the transmission of signals within the immune system and also for a variety of other functions throughout the organism. Hypothesizing a potential correlation between this dysfunction and hemodynamic impairment, we wanted to assess the impact of vagal stimulation on myocardial inflammation and function in a rat model of lipopolysaccharide (LPS)-induced septic shock. As the myocardial tissue is (sparsely) innervated by the N. vagus, there might be an important anti-inflammatory effect in the heart, inhibiting proinflammatory gene expression in cardiomyocytes and improving cardiac function. We performed stimulation of the right cervical branch of the N. vagus in vagotomized, endotoxemic (1 mg/kg body weight LPS, intravenously) rats. Hemodynamic parameters were assessed over time using a left ventricular pressure-volume catheter. After the experiments, hearts and blood plasma were collected, and the expression of proinflammatory cytokines was measured using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. After vagotomy, the inflammatory response was aggravated, measurable by elevated cytokine levels in plasma and ventricular tissue. In concordance, cardiac impairment during septic shock was pronounced in these animals. To reverse both hemodynamic and immunologic effects of diminished vagal tone, even a brief stimulation of the N. vagus was enough during initial LPS infusion. Overall, the N. vagus might play a major role in maintaining hemodynamic stability and cardiac immune homeostasis during septic shock. Copyright © 2014 Elsevier Inc. All rights reserved.

Psychoactive bacteria Lactobacillus rhamnosus (JB-1) elicits rapid frequency facilitation in vagal afferents.

Science.gov (United States)

Perez-Burgos, Azucena; Wang, Bingxian; Mao, Yu-Kang; Mistry, Bhavik; McVey Neufeld, Karen-Anne; Bienenstock, John; Kunze, Wolfgang

2013-01-15

Mounting evidence supports the influence of the gut microbiome on the local enteric nervous system and its effects on brain chemistry and relevant behavior. Vagal afferents are involved in some of these effects. We previously showed that ingestion of the probiotic bacterium Lactobacillus rhamnosus (JB-1) caused extensive neurochemical changes in the brain and behavior that were abrogated by prior vagotomy. Because information can be transmitted to the brain via primary afferents encoded as neuronal spike trains, our goal was to record those induced by JB-1 in vagal afferents in the mesenteric nerve bundle and thus determine the nature of the signals sent to the brain. Male Swiss Webster mice jejunal segments were cannulated ex vivo, and serosal and luminal compartments were perfused separately. Bacteria were added intraluminally. We found no evidence for translocation of labeled bacteria across the epithelium during the experiment. We recorded extracellular multi- and single-unit neuronal activity with glass suction pipettes. Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective. JB-1 significantly augmented multiunit discharge responses to an intraluminal distension pressure of 31 hPa. Prior subdiaphragmatic vagotomy abolished all of the JB-1-evoked effects. This detailed exploration of the neuronal spike firing that encodes behavioral signaling to the brain may be useful to identify effective psychoactive bacteria and thereby offer an alternative new perspective in the field of psychiatry and comorbid conditions.

[Radiofrequency ablation of hepatocellular carcinoma].

Science.gov (United States)

Widmann, Gerlig; Schullian, Peter; Bale, Reto

2013-03-01

Percutaneous radiofrequency ablation (RFA) is well established in the treatment of hepatocellular carcinoma (HCC). Due to its curative potential, it is the method of choice for non resectable BCLC (Barcelona Liver Clinic) 0 and A. RFA challenges surgical resection for small HCC and is the method of choice in bridging for transplantation and recurrence after resection or transplantation. The technical feasibility of RFA depends on the size and location of the HCC and the availability of ablation techniques (one needle techniques, multi-needle techniques). More recently, stereotactic multi-needle techniques with 3D trajectory planning and guided needle placement substantially improve the spectrum of treatable lesions including large volume tumors. Treatment success depends on the realization of ablations with large intentional margins of tumor free tissue (A0 ablation in analogy to R0 resection), which has to be documented by fusion of post- with pre-ablation images, and confirmed during follow-up imaging.

A spectral analysis of ablating meteors

Science.gov (United States)

Bloxam, K.; Campbell-Brown, M.

2017-09-01

Meteor ablation features in the spectral lines occurring at 394, 436, 520, and 589 nm were observed using a four-camera spectral system between September and December 2015. In conjunction with this multi-camera system the Canadian Automated Meteor Observatory was used to observe the orbital parameters and fragmentation of these meteors. In total, 95 light curves with complete data in the 520 and 589 nm filters were analyzed; some also had partial or complete data in the 394 nm filter, but no usable data was collected with the 436 nm filter. Of the 95 events, 70 exhibited some degree of differential ablation, and in all except 3 of these 70 events the 589 nm filter started or ended sooner compared with the 520 nm filter, indicating early ablation at the 589 nm wavelength. In the majority of cases the meteor showed evidence of fragmentation regardless of the type of ablation (differential or uniform). A surprising result was the lack of correlation found concerning the KB parameter, linked to meteoroid strength, and differential ablation. In addition, 22 shower-associated meteors were observed; Geminids showed mainly slight differential ablation, while Taurids were more likely to ablate uniformly.

Hypocretin-1 (orexin A) prevents the effects of hypoxia/hypercapnia and enhances the GABAergic pathway from the lateral paragigantocellular nucleus to cardiac vagal neurons in the nucleus ambiguus.

Science.gov (United States)

Dergacheva, O; Philbin, K; Bateman, R; Mendelowitz, D

2011-02-23

Hypocretins (orexins) are hypothalamic neuropeptides that play a crucial role in regulating sleep/wake states and autonomic functions including parasympathetic cardiac activity. We have recently demonstrated stimulation of the lateral paragigantocellular nucleus (LPGi), the nucleus which is thought to play a role in rapid eye movement (REM) sleep control, activates an inhibitory pathway to preganglionic cardiac vagal neurons in the nucleus ambiguus (NA). In this study we test the hypothesis that hypocretin-1 modulates the inhibitory neurotransmission to cardiac vagal neurons evoked by stimulation of the LPGi using whole-cell patch-clamp recordings in an in vitro brain slice preparation from rats. Activation of hypocretin-1 receptors produced a dose-dependent and long-term facilitation of GABAergic postsynaptic currents evoked by electrical stimulation of the LPGi. Hypoxia/hypercapnia diminished LPGi-evoked GABAergic current in cardiac vagal neurons and this inhibition by hypoxia/hypercapnia was prevented by pre-application of hypocretin-1. The action of hypocretin-1 was blocked by the hypocretin-1 receptor antagonist SB-334867. Facilitation of LPGi-evoked GABAergic current in cardiac vagal neurons under both normal condition and during hypoxia/hypercapnia could be the mechanism by which hypocretin-1 affects parasympathetic cardiac function and heart rate during REM sleep. Furthermore, our findings indicate a new potential mechanism that might be involved in the cardiac arrhythmias, bradycardia, and sudden cardiac death that can occur during sleep. Copyright © 2011. Published by Elsevier Ltd.

CT-guided radiofrequency tumor ablation in children

International Nuclear Information System (INIS)

Botsa, Evanthia; Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas; Koutsogiannis, Ioannis; Ziakas, Panayiotis D.; Alexopoulou, Efthimia

2014-01-01

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

CT-guided radiofrequency tumor ablation in children

Energy Technology Data Exchange (ETDEWEB)

Botsa, Evanthia [National and Kapodistrian University of Athens, First Pediatric Clinic, Agia Sofia Children' s Hospital, Athens (Greece); Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas [Sotiria General Hospital for Chest Diseases, Department of Medical Imaging and Interventional Radiology, Athens (Greece); Koutsogiannis, Ioannis [General Military Hospital NIMTS, Department of Medical Imaging, Athens (Greece); Ziakas, Panayiotis D. [Warren Alpert Medical School of Brown University Rhode Island Hospital, Division of Infectious Diseases, Providence, RI (United States); Alexopoulou, Efthimia [Attikon University Hospital, Second Department of Radiology, Athens University School of Medicine, Athens (Greece)

2014-11-15

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

High job control enhances vagal recovery in media work.

Science.gov (United States)

Lindholm, Harri; Sinisalo, Juha; Ahlberg, Jari; Jahkola, Antti; Partinen, Markku; Hublin, Christer; Savolainen, Aslak

2009-12-01

Job strain has been linked to increased risk of cardiovascular diseases. In modern media work, time pressures, rapidly changing situations, computer work and irregular working hours are common. Heart rate variability (HRV) has been widely used to monitor sympathovagal balance. Autonomic imbalance may play an additive role in the development of cardiovascular diseases. To study the effects of work demands and job control on the autonomic nervous system recovery among the media personnel. From the cross-sectional postal survey of the employees in Finnish Broadcasting Company (n = 874), three age cohorts (n = 132) were randomly selected for an analysis of HRV in 24 h electrocardiography recordings. In the middle-aged group, those who experienced high job control had significantly better vagal recovery than those with low or moderate control (P work rather than low demands seemed to enhance autonomic recovery in middle-aged media workers. This was independent of poor health habits such as smoking, physical inactivity or alcohol consumption.

The vagal innervation of the gut and immune homeostasis.

Science.gov (United States)

Matteoli, Gianluca; Boeckxstaens, Guy E

2013-08-01

The central nervous system interacts dynamically with the immune system to modulate inflammation through humoral and neural pathways. Recently, in animal models of sepsis, the vagus nerve (VN) has been proposed to play a crucial role in the regulation of the immune response, also referred to as the cholinergic anti-inflammatory pathway. The VN, through release of acetylcholine, dampens immune cell activation by interacting with α-7 nicotinic acetylcholine receptors. Recent evidence suggests that the vagal innervation of the gastrointestinal tract also plays a major role controlling intestinal immune activation. Indeed, VN electrical stimulation potently reduces intestinal inflammation restoring intestinal homeostasis, whereas vagotomy has the reverse effect. In this review, we will discuss the current understanding concerning the mechanisms and effects involved in the cholinergic anti-inflammatory pathway in the gastrointestinal tract. Deeper investigation on this counter-regulatory neuroimmune mechanism will provide new insights in the cross-talk between the nervous and immune system leading to the identification of new therapeutic targets to treat intestinal immune disease.

Advances in laser ablation of materials

International Nuclear Information System (INIS)

Singh, R.K.; Lowndes, D.H.; Chrisey, D.B.; Fogarassy, E.; Narayan, J.

1998-01-01

The symposium, Advances in Laser Ablation of Materials, was held at the 1998 MRS Spring Meeting in San Francisco, California. The papers in this symposium illustrate the advances in pulsed laser ablation for a wide variety of applications involving semiconductors, superconductors, metals, ceramics, and polymers. In particular, advances in the deposition of oxides and related materials are featured. Papers dealing with both fundamentals and the applications of laser ablation are presented. Topical areas include: fundamentals of ablation and growth; in situ diagnostics and nanoscale synthesis advances in laser ablation techniques; laser surface processing; pulsed laser deposition of ferroelectric, magnetic, superconducting and optoelectronic thin films; and pulsed laser deposition of carbon-based and polymeric materials. Sixty papers have been processed separately for inclusion on the data base

Efficacy and Safety of Radiofrequency Ablation for Focal Hepatic Lesions Adjacent to Gallbladder: Reconfiguration of the Ablation Zone through Probe Relocation and Ablation Time Reduction.

Science.gov (United States)

Choi, In Young; Kim, Pyo Nyun; Lee, Sung Gu; Won, Hyung Jin; Shin, Yong Moon

2017-10-01

To evaluate the safety and efficacy of radiofrequency (RF) ablation for treatment of focal hepatic lesions adjacent to the gallbladder with electrode relocation and ablation time reduction. Thirty-nine patients who underwent RF ablation for focal hepatic lesions adjacent to the gallbladder (≤ 10 mm) were evaluated retrospectively from January 2011 to December 2014 (30 men and 9 women; age range, 51-85 y; mean age, 65 y). Of 36 patients with hepatocellular carcinoma, 3 had a second treatment for recurrence (mean tumor size, 15 mm ± 6). Patients were divided into 2 subgroups based on lesion distance from the gallbladder: nonabutting (> 5 mm; n = 19) and abutting (≤ 5 mm; n = 20). Electrodes were inserted parallel to the gallbladder through the center of a tumor in the nonabutting group and through the center of the expected ablation zone between a 5-mm safety zone on the liver side and the gallbladder in the abutting group. Ablation time was decreased in proportion to the transverse diameter of the expected ablation zone. Technical success and technical effectiveness rates were 89.7% and 97.4%, respectively, with no significant differences between groups (P = 1.00). Local tumor progression was observed in 3 patients (1 in the nonabutting group and 2 in the abutting group; P = 1.00). There were no major complications. The gallbladder was thickened in 10 patients, with no significant difference between groups (P = .72). Biloma occurred in 1 patient in the nonabutting group. RF ablation with electrode relocation and reduction of ablation time can be a safe and effective treatment for focal hepatic lesions adjacent to the gallbladder. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

3D Modelling and monitoring of denervated muscle under Functional Electrical Stimulation treatment and associated bone structural changes

Directory of Open Access Journals (Sweden)

Paolo Gargiulo

2011-03-01

Full Text Available A novel clinical rehabilitation method for patients who have permanent and non recoverable muscle denervation in the legs was developed in the frame of the European Project RISE. The technique is based on FES and the project results shows, in these severely disabled patients, restoration of muscle tissue and function. This study propose novel methods based on image processing technique and medical modelling to monitor growth in denervated muscle treated with FES. Geometrical and structural changes in muscle and bone are studied and modelled. Secondary effects on the bone mineral density produced by the stimulation treatment and due the elicited muscle contraction are also investigated. The restoration process in DDM is an important object of discussion since there isn’t yet a complete understanding of the mechanisms regulating growth in denervated muscle. This study approaches the problem from a macroscopic point of view, developing 3-dimensional models of the whole stimulated muscles and following changes in volume, geometry and density very accurately. The method is based on the acquisition of high resolution Spiral CT scans from patients who have long-term flaccid paraplegia and the use of special image processing tools allowing tissue discriminations and muscle segmentation. Three patients were measured at different points of time during 4 years of electrical stimulation treatment. In this study is quantitatively demonstrated the influences of FES treatment on the different quadriceps bellies. The rectus femoris muscle is positioned in the middle of the quadriceps and responds (in general better to stimulation. In a patient with abundant adipose tissue surrounding the quadriceps, rectus femoris almost doubled the volume during the FES treatment while in the other bellies the changes measured were minimal. The analysis of the density shows clearly a restoration of the muscular structure in the growing muscle. The remarkable increase of

Characterization of tracked radiofrequency ablation in phantom

International Nuclear Information System (INIS)

Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L.

2007-01-01

In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4±0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA

Infant diet, gender and the normative development of vagal tone and heart period during the first two years of life

Science.gov (United States)

Relationships between early postnatal diet and the development of cardiac regulation were studied using resting vagal tone and heart period measures obtained quarterly during infancy and at 2 years in 158 breast-fed, 159 milk formula-fed, and 148 soy formula-fed infants. Both measures increased acro...

Is pancreatic polypeptide response to food ingestion a reliable index of vagal function in type 1 diabetes?

DEFF Research Database (Denmark)

Damholt, M B; Arlien-Soeborg, P; Hilsted, L

2006-01-01

The diagnosis of autonomic neuropathy in diabetic patients is based on cardiovascular reflex tests. Since cardiac function may be affected by arteriosclerosis and cardiomyopathy in type 1 diabetes mellitus, alternative tests reflecting vagal nerve function, in other organ systems, are needed....... In this study the pancreatic polypeptide (PP) response to a mixed meal was evaluated in healthy subjects and in recently diagnosed type 1 diabetic patients....

Renal Sympathetic Denervation by CT-Guided Ethanol Injection: A Phase II Pilot Trial of a Novel Technique

International Nuclear Information System (INIS)

Ricke, J.; Seidensticker, M.; Becker, S.; Schiefer, J.; Adamchic, I.; Lohfink, K.; Kandulski, M.; Heller, A.; Mertens, P. R.

2016-01-01

ObjectivesCT-guided ethanol-mediated renal sympathetic denervation in treatment of therapy-resistant hypertension was performed to assess patient safety and collect preliminary data on treatment efficacy.Materials and MethodsEleven patients with therapy-resistant hypertension (blood pressure of >160 mmHg despite three different antihypertensive drugs including a diuretic) and following screening for secondary causes were enrolled in a phase II single arm open label pilot trial of CT-guided neurolysis of sympathetic renal innervation. Primary endpoint was safety, and secondary endpoint was a decrease of the mean office as well as 24-h systolic blood pressure in follow-up. Follow-up visits at 4 weeks, 3, and 6 months included 24-h blood pressure assessments, office blood pressure, laboratory values, as well as full clinical and quality of life assessments.ResultsNo toxicities ≥3° occurred. Three patients exhibited worsened kidney function in follow-up analyses. When accounting all patients, office systolic blood pressure decreased significantly at all follow-up visits (maximal mean decrease −41.2 mmHg at 3 months). The mean 24-h systolic blood pressure values decreased significantly at 3 months, but not at 6 months (mean: −9.7 and −6.3 mmHg, respectively). Exclusion of five patients who had failed catheter-based endovascular denervation and/or were incompliant for antihypertensive drug intake revealed a more pronounced decrease of 24-h systolic blood pressure (mean: −18.3 and −15.2 mmHg at 3 and 6 months, p = 0.03 and 0.06).ConclusionCT-guided sympathetic denervation proved to be safe and applicable under various anatomical conditions with more renal arteries and such of small diameter

Renal Sympathetic Denervation by CT-Guided Ethanol Injection: A Phase II Pilot Trial of a Novel Technique

Energy Technology Data Exchange (ETDEWEB)

Ricke, J., E-mail: jens.ricke@med.ovgu.de; Seidensticker, M.; Becker, S. [Otto-von-Guericke University Magdeburg, Department of Radiology and Nuclear Medicine, Universitätsklinikum Magdeburg AöR (Germany); Schiefer, J. [Universitätsklinikum Magdeburg AöR, Department of Nephrology and Hypertension, Diabetes and Endocrinology (Germany); Adamchic, I.; Lohfink, K. [Otto-von-Guericke University Magdeburg, Department of Radiology and Nuclear Medicine, Universitätsklinikum Magdeburg AöR (Germany); Kandulski, M.; Heller, A.; Mertens, P. R. [Universitätsklinikum Magdeburg AöR, Department of Nephrology and Hypertension, Diabetes and Endocrinology (Germany)

2016-02-15

ObjectivesCT-guided ethanol-mediated renal sympathetic denervation in treatment of therapy-resistant hypertension was performed to assess patient safety and collect preliminary data on treatment efficacy.Materials and MethodsEleven patients with therapy-resistant hypertension (blood pressure of >160 mmHg despite three different antihypertensive drugs including a diuretic) and following screening for secondary causes were enrolled in a phase II single arm open label pilot trial of CT-guided neurolysis of sympathetic renal innervation. Primary endpoint was safety, and secondary endpoint was a decrease of the mean office as well as 24-h systolic blood pressure in follow-up. Follow-up visits at 4 weeks, 3, and 6 months included 24-h blood pressure assessments, office blood pressure, laboratory values, as well as full clinical and quality of life assessments.ResultsNo toxicities ≥3° occurred. Three patients exhibited worsened kidney function in follow-up analyses. When accounting all patients, office systolic blood pressure decreased significantly at all follow-up visits (maximal mean decrease −41.2 mmHg at 3 months). The mean 24-h systolic blood pressure values decreased significantly at 3 months, but not at 6 months (mean: −9.7 and −6.3 mmHg, respectively). Exclusion of five patients who had failed catheter-based endovascular denervation and/or were incompliant for antihypertensive drug intake revealed a more pronounced decrease of 24-h systolic blood pressure (mean: −18.3 and −15.2 mmHg at 3 and 6 months, p = 0.03 and 0.06).ConclusionCT-guided sympathetic denervation proved to be safe and applicable under various anatomical conditions with more renal arteries and such of small diameter.

Simple spherical ablative-implosion model

International Nuclear Information System (INIS)

Mayer, F.J.; Steele, J.T.; Larsen, J.T.

1980-01-01

A simple model of the ablative implosion of a high-aspect-ratio (shell radius to shell thickness ratio) spherical shell is described. The model is similar in spirit to Rosenbluth's snowplow model. The scaling of the implosion time was determined in terms of the ablation pressure and the shell parameters such as diameter, wall thickness, and shell density, and compared these to complete hydrodynamic code calculations. The energy transfer efficiency from ablation pressure to shell implosion kinetic energy was examined and found to be very efficient. It may be possible to attach a simple heat-transport calculation to our implosion model to describe the laser-driven ablation-implosion process. The model may be useful for determining other energy driven (e.g., ion beam) implosion scaling

Field enhancement induced laser ablation

DEFF Research Database (Denmark)

Fiutowski, Jacek; Maibohm, Christian; Kjelstrup-Hansen, Jakob

Sub-diffraction spatially resolved, quantitative mapping of strongly localized field intensity enhancement on gold nanostructures via laser ablation of polymer thin films is reported. Illumination using a femtosecond laser scanning microscope excites surface plasmons in the nanostructures....... The accompanying field enhancement substantially lowers the ablation threshold of the polymer film and thus creates local ablation spots and corresponding topographic modifications of the polymer film. Such modifications are quantified straightforwardly via scanning electron and atomic force microscopy. Thickness...

Radiofrequency ablation in dermatology

Directory of Open Access Journals (Sweden)

Sachdeva Silonie

2007-01-01

Full Text Available Radiofreqeuency ablation is a versatile dermatosurgical procedure used for surgical management of skin lesions by using various forms of alternating current at an ultra high frequency. The major modalities in radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation in dermatosurgical practice has gained importance in recent years as it can be used to treat most of the skin lesions with ease in less time with clean surgical field due to adequate hemostasis and with minimal side effects and complications. This article focuses on the major tissue effects and factors influencing radiofrequency ablation and its application for various dermatological conditions.

Comparison between neurectomy and botulinum toxin A injection for denervated skeletal muscle.

Science.gov (United States)

Tsai, Feng-Chou; Hsieh, Ming-Shium; Chou, Chih-Ming

2010-08-01

Neurectomy and botulinum toxin A (BoNT-A) injection cause denervated muscle atrophy, but questions remain about their clinical utility. We investigated time-series alterations of rat muscle weight, functional deficits, signaling pathways, and microscopic structures, to gain an understanding of the clinical implications. Between 2008 and 2009, the maximal calf circumference of patients for calf reduction either by neurectomy or BoNT-A injections were recorded for study. A rat skeletal muscle model was established through repeated or dose-adjusted BoNT-A injections and neurectomy. The survival, apoptosis pathways, functional deficits, and microscopic structures were investigated using Western blot, sciatic functional index (SFI), and transmission electron microscopy (TEM), respectively. The rat muscle weight ratio of the BoNT-A group had recovered to 89.3 +/- 3.8% by week 58, but it never recovered in the neurectomy group. Muscle weight reduction by BoNT-A not only depended on the dose, but additive effects were also obtained through repeated injections. Rat SFI demonstrated rapid recovery in both groups. Molecular expressions showed a coherent and biphasic pattern. p-Akt and apoptosis-inducing factor (AIF) were upregulated significantly, with a peak at 8 weeks in the neurectomy group (p structure disruption and sarcomere discontinuity in the neurectomy and BoNT-A groups, respectively. We demonstrated that denervation induced lasting muscle weight and structural changes of different degrees. Muscle weight reduction by BoNT-A was related to frequency and dose. AIF-mediated caspase-independent apoptosis was significantly different for neurectomy and BoNT-A injection.

Percutaneous Microwave Ablation of Renal Angiomyolipomas

Energy Technology Data Exchange (ETDEWEB)

Cristescu, Mircea, E-mail: mcristescu@uwhealth.org [University of Wisconsin, Department of Radiology (United States); Abel, E. Jason, E-mail: abel@urology.wisc.edu [University of Wisconsin, Department of Urology (United States); Wells, Shane, E-mail: swells@uwhealth.org; Ziemlewicz, Timothy J., E-mail: tziemlewicz@uwhealth.org [University of Wisconsin, Department of Radiology (United States); Hedican, Sean P., E-mail: hedican@surgery.wisc.edu [University of Wisconsin, Department of Urology (United States); Lubner, Megan G., E-mail: mlubner@uwhealth.org; Hinshaw, J. Louis, E-mail: jhinshaw@uwhealth.org; Brace, Christopher L., E-mail: cbrace@uwhealth.org; Lee, Fred T., E-mail: flee@uwhealth.org [University of Wisconsin, Department of Radiology (United States)

2016-03-15

PurposeTo evaluate the safety and efficacy of US-guided percutaneous microwave (MW) ablation in the treatment of renal angiomyolipoma (AML).Materials and MethodsFrom January 2011 to April 2014, seven patients (5 females and 2 males; mean age 51.4) with 11 renal AMLs (9 sporadic type and 2 tuberous sclerosis associated) with a mean size of 3.4 ± 0.7 cm (range 2.4–4.9 cm) were treated with high-powered, gas-cooled percutaneous MW ablation under US guidance. Tumoral diameter, volume, and CT/MR enhancement were measured on pre-treatment, immediate post-ablation, and delayed post-ablation imaging. Clinical symptoms and creatinine were assessed on follow-up visits.ResultsAll ablations were technically successful and no major complications were encountered. Mean ablation parameters were ablation power of 65 W (range 60–70 W), using 456 mL of hydrodissection fluid per patient, over 4.7 min (range 3–8 min). Immediate post-ablation imaging demonstrated mean tumor diameter and volume decreases of 1.8 % (3.4–3.3 cm) and 1.7 % (27.5–26.3 cm{sup 3}), respectively. Delayed imaging follow-up obtained at a mean interval of 23.1 months (median 17.6; range 9–47) demonstrated mean tumor diameter and volume decreases of 29 % (3.4–2.4 cm) and 47 % (27.5–12.1 cm{sup 3}), respectively. Tumoral enhancement decreased on immediate post-procedure and delayed imaging by CT/MR parameters, indicating decreased tumor vascularity. No patients required additional intervention and no patients experienced spontaneous bleeding post-ablation.ConclusionOur early experience with high-powered, gas-cooled percutaneous MW ablation demonstrates it to be a safe and effective modality to devascularize and decrease the size of renal AMLs.

Renal Denervation for Treating Resistant Hypertension: Current Evidence and Future Insights from a Global Perspective

OpenAIRE

Castro Torres, Y.; Katholi, Richard E.

2013-01-01

Adequate blood pressure control represents an important goal for all physicians due to the complications of hypertension which reduce patients' quality of life. A new interventional strategy to reduce blood pressure has been developed for patients with resistant hypertension. Catheter-based renal denervation has demonstrated excellent results in recent investigations associated with few side effects. With the growing diffusion of this technique worldwide, some medical societies have published...

The outcome of I-131 ablation therapy for intermediate and high-risk differentiated thyroid cancer using a strict definition of successful ablation.

Science.gov (United States)

Watanabe, Ken; Uchiyama, Mayuki; Fukuda, Kunihiko

2017-09-01

This article examines the outcome of radioactive iodine ablation therapy for thyroid cancer in high-risk patients and investigates background factors influencing ablation failure. We included 91 patients in this retrospective analysis and evaluated the ablation success rate. Successful ablation was defined as the absence of visible iodine-131 (I-131) accumulation in the thyroid bed after whole-body scans and thyroglobulin levels sex, I-131 dose, pathology, resection stump findings, tumor T category and thyroglobulin levels, which could affect ablation outcome. Successful ablation was achieved in only 14 patients (15.4%). Pre-ablation serum thyroglobulin levels were significantly higher in the ablation failure group than in the success group (P 10 ng/ml were significantly related to ablation failure after multivariate analysis (odds ratio 27.2; 95% confidence interval 2.469-299.7; P = 0.007). The ablation success rate was very low because of high thyroglobulin levels, even with high-dose I-131. High-risk patients, especially those with high thyroglobulin levels (>10 ng/ml), are unlikely to reach levels low enough to meet successful ablation criteria.

Temperature-controlled irrigated tip radiofrequency catheter ablation

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, Adrian

1998-01-01

INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

Micrometeoroid ablation simulated in the laboratory

Science.gov (United States)

Sternovsky, Zoltan; Thomas, Evan W.; DeLuca, Michael; Horanyi, Mihaly; Janches, Diego; Munsat, Tobin L.; Plane, John M. C.

2016-04-01

A facility is developed to simulate the ablation of micrometeoroids in laboratory conditions, which also allows measuring the ionization probability of the ablated material. An electrostatic dust accelerator is used to generate iron and meteoric analog particles with velocities 10-50 km/s. The particles are then introduced into a cell filled with nitrogen, air or carbon dioxide gas with pressures adjustable in the 0.02 - 0.5 Torr range, where the partial or complete ablation of the particle occurs over a short distance. An array of biased electrodes is used to collect the ionized products with spatial resolution along the ablating particles' path, allowing thus the study of the temporal resolution of the process. A simple ablation model is used to match the observations. For completely ablated particles the total collected charge directly yields the ionization efficiency for. The measurements using iron particles in N2 and air are in relatively good agreement with earlier data. The measurements with CO2 and He gases, however, are significantly different from the expectations.

Adrenergic receptors are a fallible index of adrenergic denervation hypersensitivity

DEFF Research Database (Denmark)

Dejgaard, Anders; Liggett, S B; Christensen, N J

1991-01-01

In view of evidence that neither interindividual nor induced intra-individual variations of adrenergic receptor status are related to metabolic or haemodynamic sensitivity to adrenaline in vivo, we took an alternative approach to assessment of the relevance of adrenergic receptor measurement...... by measuring these in a group of subjects with well-documented adrenergic denervation hypersensitivity, patients with diabetic autonomic neuropathy. Mononuclear leukocyte beta 2-adrenergic receptor densities (and binding affinities), measured with 125I-labelled pindolol, and isoproterenol-stimulated cyclic AMP...... accumulation, in samples from patients with insulin-dependent diabetes mellitus (IDDM) with diabetic autonomic neuropathy (n = 8), were no different from those in samples from patients with IDDM without neuropathy (n = 8), or from non-diabetic subjects (n = 8). In addition, platelet alpha 2-adrenergic receptor...

The outcome of I-131 ablation therapy for intermediate and high-risk differentiated thyroid cancer using a strict definition of successful ablation