Protective effect of preconditioning and adenosine pretreatment in experimental skeletal muscle reperfusion injury.

Science.gov (United States)

Papanastasiou, S; Estdale, S E; Homer-Vanniasinkam, S; Mathie, R T

1999-07-01

Prolonged ischaemia followed by reperfusion (I/R) of skeletal muscle results in significant tissue injury. Ischaemic preconditioning (IPC), achieved by repeated brief periods of I/R before prolonged ischaemia or adenosine pretreatment, can prevent I/R injury in cardiac muscle. The aim of this study was to ascertain in a rodent model if damage to skeletal muscle due to global hindlimb tourniquet-induced I/R could be similarly attenuated. Anaesthetized rats were randomized (n = 6-10 per group) to five groups: sham-operated controls; I/R (4 h of ischaemia, 2 h of reperfusion); IPC (three cycles of 10 min of ischaemia/10 min of reperfusion) alone; IPC immediately preceding I/R; or adenosine 1000 microg/kg immediately before I/R. At the end of reperfusion, biopsies were taken from the left gastrocnemius muscle for measurement of myeloperoxidase (MPO) and reduced glutathione (GSH). Before ischaemia and at the end of reperfusion, blood samples were taken for measurement of nitric oxide metabolites, tumour necrosis factor (TNF) alpha and macrophage inflammatory protein (MIP) 2. IPC before I/R resulted in lower levels of MPO (P < 0.001) and TNF-alpha (P = 0.004), and higher levels of GSH (P < 0.001) and nitric oxide metabolites (P = 0.002) than I/R alone. Adenosine had effects comparable to IPC pretreatment (P < 0.001 for MPO, P = 0.002 for GSH, P = 0.02 for nitric oxide metabolites and P = 0.001 for TNF-alpha). There was no difference in the blood pressure or the MIP-2 concentration among the groups. IPC or pretreatment with adenosine ameliorates the I/R injury of skeletal muscle.

Multiple therapeutic effects of progranulin on experimental acute ischaemic stroke.

Science.gov (United States)

Kanazawa, Masato; Kawamura, Kunio; Takahashi, Tetsuya; Miura, Minami; Tanaka, Yoshinori; Koyama, Misaki; Toriyabe, Masafumi; Igarashi, Hironaka; Nakada, Tsutomu; Nishihara, Masugi; Nishizawa, Masatoyo; Shimohata, Takayoshi

2015-07-01

In the central nervous system, progranulin, a glycoprotein growth factor, plays a crucial role in maintaining physiological functions, and progranulin gene mutations cause TAR DNA-binding protein-43-positive frontotemporal lobar degeneration. Although several studies have reported that progranulin plays a protective role against ischaemic brain injury, little is known about temporal changes in the expression level, cellular localization, and glycosylation status of progranulin after acute focal cerebral ischaemia. In addition, the precise mechanisms by which progranulin exerts protective effects on ischaemic brain injury remains unknown. Furthermore, the therapeutic potential of progranulin against acute focal cerebral ischaemia, including combination treatment with tissue plasminogen activator, remains to be elucidated. In the present study, we aimed to determine temporal changes in the expression and localization of progranulin after ischaemia as well as the therapeutic effects of progranulin on ischaemic brain injury using in vitro and in vivo models. First, we demonstrated a dynamic change in progranulin expression in ischaemic Sprague-Dawley rats, including increased levels of progranulin expression in microglia within the ischaemic core, and increased levels of progranulin expression in viable neurons as well as induction of progranulin expression in endothelial cells within the ischaemic penumbra. We also demonstrated that the fully glycosylated mature secretory isoform of progranulin (∼88 kDa) decreased, whereas the glycosylated immature isoform of progranulin (58-68 kDa) markedly increased at 24 h and 72 h after reperfusion. In vitro experiments using primary cells from C57BL/6 mice revealed that the glycosylated immature isoform was secreted only from the microglia. Second, we demonstrated that progranulin could protect against acute focal cerebral ischaemia by a variety of mechanisms including attenuation of blood-brain barrier disruption

Hydroxychloroquine Protects against Cardiac Ischaemia/Reperfusion Injury In Vivo via Enhancement of ERK1/2 Phosphorylation.

Directory of Open Access Journals (Sweden)

Lauren Bourke

Full Text Available An increasing number of investigations including human studies demonstrate that pharmacological ischaemic preconditioning is a viable way to protect the heart from myocardial ischaemia/reperfusion (I/R injury. This study investigated the role of hydroxychloroquine (HCQ in the heart during I/R injury. In vitro and in vivo models of myocardial I/R injury were used to assess the effects of HCQ. It was found that HCQ was protective in neonatal rat cardiomyocytes through inhibition of apoptosis, measured by TUNEL and cleaved caspase-3. This protection in vitro was mediated through enhancement of ERK1/2 phosphorylation mediated by HCQ in a dose-dependent fashion. A decrease in infarct size was observed in an in vivo model of myocardial I/R injury in HCQ treated animals and furthermore this protection was blocked in the presence of the ERK1/2 inhibitor U0126. For the first time, we have shown that HCQ promotes a preconditioning like protection in an in vivo simulated rat myocardial I/R injury model. Moreover, it was shown that HCQ is protective via enhanced phosphorylation of the pro-survival kinase ERK1/2.

Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

International Nuclear Information System (INIS)

Muzzarelli, Stefano; Pfisterer, Matthias Emil; Zellweger, Michael Johannes; Mueller-Brand, Jan

2009-01-01

The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping (≥1 mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS-SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS ≥ 2. An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometry. (orig.)

Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

Energy Technology Data Exchange (ETDEWEB)

Muzzarelli, Stefano; Pfisterer, Matthias Emil; Zellweger, Michael Johannes [University Hospital Basel, Cardiology Department, Basel (Switzerland); Mueller-Brand, Jan [University Hospital Basel, Nuclear Medicine Department, Basel (Switzerland)

2009-11-15

The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping ({>=}1 mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS-SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS {>=} 2. An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometry. (orig.)

Improved GFR and renal plasma perfusion following remote ischaemic conditioning in a porcine kidney transplantation model

DEFF Research Database (Denmark)

Krogstrup, Nicoline V; Soendergaard, Peter; Secher, Niels G

2012-01-01

Delayed graft function (DGF) complicates approximately 25% of kidney allografts donated after brain death (DBD). Remote ischaemic conditioning (rIC) involves brief, repetitive, ischaemia in a distant tissue in connection with ischaemia/reperfusion in the target organ. rIC has been shown to induce...

Diagnosis of ischaemic heart disease with thallium-201

Energy Technology Data Exchange (ETDEWEB)

Human, G P [Pretoria Univ. (South Africa). Dept. of Internal Medicine; Dormehl, I [Atomic Energy Board, Pelindaba, Pretoria (South Africa). Life Sciences Div.

1981-04-04

Thallium-201 is very suitable for cardiac imaging because of its physical characteristics and biological behaviour. Perfusion defects caused by ischaemia, necrosis or fibrosis are represented by 'cold spots' on the myocardial scan. In this article we report our experience with this method in the diagnosis of ischaemic heart disease in 117 patients. Excellent correlation was found with clinical, electrocardiographic and angiographic parameters. Both sensitivity and specificity for the diagnosis of ischaemic heart disease were higher with /sup 201/Tl scintigraphy than with existing diagnostic methods.

Recent concepts concerning cerebral ischaemia in man and their implications in therapeutic evaluations

Energy Technology Data Exchange (ETDEWEB)

Depresseux, J C

1987-06-18

Recent concepts concerning focal cerebral ischaemia in man and resulting from the data obtained with positron emission tomography are reported. The evolutive steps in the ischaemic process are divided into: perfusion reserve; extraction reserve recruitment; ischaemic penumbra; lesional process and post-lesional developments. Circulatory and metabolic patterns corresponding to these evolutive steps are described and illustrated. The potentials of these data as guide-lines in therapeutic trial methodology are discussed.

Recent concepts concerning cerebral ischaemia in man and their implications in therapeutic evaluations

International Nuclear Information System (INIS)

Depresseux, J.C.

1987-01-01

Recent concepts concerning focal cerebral ischaemia in man and resulting from the data obtained with positron emission tomography are reported. The evolutive steps in the ischaemic process are divided into: perfusion reserve; extraction reserve recruitment; ischaemic penumbra; lesional process and post-lesional developments. Circulatory and metabolic patterns corresponding to these evolutive steps are described and illustrated. The potentials of these data as guide-lines in therapeutic trial methodology are discussed [fr

Reversible myocardial ischaemia or irreversible myocardial fibrosis

International Nuclear Information System (INIS)

Mathey, D.; Hanrath, P.; Kupper, W.; Bleifeld, W.; Montz, R.; Knop, J.; Stritzke, P.; Kroeger, E.; Bleese, N.

1978-01-01

The results of biphasis 201 thallium ( 201 Tl) scanning were compared with those of coronary arteriography, left ventricular angiography and stress ECG in 56 patients with coronary artery disease and six with no evidence of heart disease. There were 104 201 Tl defects, 50 of them reversible. The defects were always located in the area supplied by a critically stenotic coronary artery. Correlation of regional wall motion with 201 Tl activity demonstrated that in all forms of abnormal wall motion there was either ischaemia or fibrosis. The resting LV angiogram thus does not make it possible to distinguish between myocardial ischaemia and fibrosis. Taking the LV angiogram as a standard, the rate of false-positive 201 Tl scintigrams was 5%, that of false-negative ones 23%. The biphasic 201 Tl scintigram was more sensitive than the stress ECG in detecting myocardial ischaemia. It furthermore made it possible to localize the ischaemic (or fibrotic) region within the LV and to estimate its size. (orig.) [de

Tissue Doppler echocardiography reveals impaired cardiac function in patients with reversible ischaemia

DEFF Research Database (Denmark)

Hoffmann, Søren; Mogelvang, Rasmus; Sogaard, Peter

2011-01-01

AIMS: To determine if echocardiographic tissue Doppler imaging (TDI) performed at rest detects reduced myocardial function in patients with reversible ischaemia. METHODS AND RESULTS: Eighty-four patients with angina pectoris, no previous history of ischaemic heart disease and normal left ventricu...

Three-dimensional whole-brain perfused blood volume imaging with multimodal CT for evaluation of acute ischaemic stroke

International Nuclear Information System (INIS)

Lu, J.; Zhang, M.; Cao, Y.; Ma, Q.; Chen, J.; Ji, X.; Li, K.

2011-01-01

Aim: To determine the diagnostic value of integrating three-dimensional perfused blood volume (3D PBV) with multimodal computed tomography (CT) [non-enhanced CT (NECT), CT perfusion (CTP), and CT angiography (CTA)] in acute ischaemic stroke. Materials and methods: NECT, CTP, and CTA were performed in 25 acute ischaemic stroke patients. The ischaemia detection rate of 3D PBV was compared with the results of baseline NECT and CTP. The correlation of ischaemic lesion volume between 3D PBV, CTP images, and follow-up NECT were analysed. Results: NECT demonstrated ischaemic signs in 12 of 25 patients with proven infarction. CTP maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) all demonstrated perfusion deficits in 21 of 25 patients. However, 3D PBV demonstrated perfusion deficits in all of the 25 patients. Among the 25 patients, a strong correlation was found between PBV and the follow-up NECT infarct (r = 0.858). The correlation between CTP and the follow-up NECT infarct as following: CBF (r = 0.718), CBV (r = 0.785), and TTP (r = 0.569). In 14 thrombolytic patients, strong correlation was found between the ischaemic volume on 3D PBV and follow-up NECT (r = 0.798). Conclusion: In acute stroke patients, the combination of 3D PBV and multimodal CT (NECT, CTP, and CTA) can improve the detection rate of ischaemia and enable assessment of the full extent of ischaemia, which correlates well with follow-up NECT.

Prognostic significance of distal blood pressure measurements in patients with severe ischaemia

DEFF Research Database (Denmark)

Paaske, William; Tønnesen, K H

1980-01-01

The clinical course was followed and the ankle and toe blood pressures were measured with the strain gauge technique on 5 occasions during 2 years in 43 patients with pain at rest and/or ischaemic ulceration due to severe ischaemia of the legs on the basis of occlusive arterial disease. Although...

The natural history of prevalent ischaemic heart disease in middle-aged men.

Science.gov (United States)

Lampe, F C; Whincup, P H; Wannamethee, S G; Shaper, A G; Walker, M; Ebrahim, S

2000-07-01

To describe the long-term outcome of different forms of symptomatic and asymptomatic ischaemic heart disease in middle-aged men. 7735 men aged 40-59, randomly selected from 24 general practices in Britain were classified into one of seven ischaemic heart disease groups according to a questionnaire and electrocardiogram (ECG): I=diagnosed myocardial infarction; II=unrecognized myocardial infarction; III= diagnosed angina; IV=angina symptoms; V=possible myocardial infarction symptoms; VI=ECG ischaemia or possible myocardial infarction; VII=no evidence of ischaemic heart disease. The association of disease group with a range of fatal and non-fatal outcomes during 15 years of follow-up was assessed. At baseline 25% of men had evidence of ischaemic heart disease (groups I-VI). Risks of major ischaemic heart disease events, total and cardiovascular mortality, stroke, and major cardiovascular events tended to increase strongly from group VII to I. Diagnosed myocardial infarction was associated with a much poorer prognosis than all other groups (including unrecognized infarction) for all cardiovascular outcomes other than stroke. The relative risk associated with ischaemic heart disease at baseline declined dramatically over time. However, men with myocardial infarction who survived event-free for 10 years continued to experience a high excess risk in the subsequent 5 years, in contrast to event-free survivors of angina and other ischaemic heart disease. Adjusted to an average age of 50, the percentage of men surviving for 15 years free of a new major cardiovascular event was 44 for diagnosed myocardial infarction, 52 for unrecognized myocardial infarction, 66 for diagnosed angina, 68 for angina symptoms, 73 for possible myocardial infarction symptoms, 73 for ECG ischaemia, and 79 for no ischaemic heart disease. Comparison of outcome between prevalent and incident myocardial infarction illustrated the improved prognosis of men surviving the initial years after their event

Inhalation gases or gaseous mediators as neuroprotectants for cerebral ischaemia.

Science.gov (United States)

Sutherland, Brad A; Harrison, Joanne C; Nair, Shiva M; Sammut, Ivan A

2013-01-01

Ischaemic stroke is one of the leading causes of morbidity and mortality worldwide. While recombinant tissue plasminogen activator can be administered to produce thrombolysis and restore blood flow to the ischaemic brain, therapeutic benefit is only achieved in a fraction of the subset of patients eligible for fibrinolytic intervention. Neuroprotective therapies attempting to restrict the extent of brain injury following cerebral ischaemia have not been successfully translated into the clinic despite overwhelming pre-clinical evidence of neuroprotection. Therefore, an adequate treatment for the majority of acute ischaemic stroke patients remains elusive. In the stroke literature, the use of therapeutic gases has received relatively little attention. Gases such as hyperbaric and normobaric oxygen, xenon, hydrogen, helium and argon all possess biological effects that have shown to be neuroprotective in pre-clinical models of ischaemic stroke. There are significant advantages to using gases including their relative abundance, low cost and feasibility for administration, all of which make them ideal candidates for a translational therapy for stroke. In addition, modulating cellular gaseous mediators including nitric oxide, carbon monoxide, and hydrogen sulphide may be an attractive option for ischaemic stroke therapy. Inhalation of these gaseous mediators can also produce neuroprotection, but this strategy remains to be confirmed as a viable therapy for ischaemic stroke. This review highlights the neuroprotective potential of therapeutic gas therapy and modulation of gaseous mediators for ischaemic stroke. The therapeutic advantages of gaseous therapy offer new promising directions in breaking the translational barrier for ischaemic stroke.

Idarucizumab in Three Patients Needing Urgent Surgical Intervention and One Case of Intravenous Thrombolysis in Ischaemic Stroke

Directory of Open Access Journals (Sweden)

Fredrik Andreas von Wowern

2017-05-01

Full Text Available Objective: To describe the benefits of reversal of the anticoagulation effects of dabigatran etexilate in patients requiring urgent surgery or thrombolysis for ischaemic stroke. Materials and methods: Four patients, treated with dabigatran etexilate and presenting with cholecystitis, tibial fracture, lower limb ischaemia and ischaemic stroke, respectively. Results: Administration of idarucizumab normalized bleeding parameters and provided safe conditions for surgery and, in one case, successful thrombolysis of an ischaemic stroke. Conclusion: The introduction of an effective reversal agent for dabigatran etexilate allows physicians perform surgery under conditions of normal coagulation and permits thrombolysis in patients with ischaemic stroke despite being treated with dabigatran etexilate.

Women with dysmenorrhoea are hypersensitive to experimentally induced forearm ischaemia during painful menstruation and during the pain-free follicular phase.

Science.gov (United States)

Iacovides, S; Avidon, I; Baker, F C

2015-07-01

Monthly primary dysmenorrhoeic pain is associated with increased sensitivity to painful stimuli, particularly in deep tissue. We investigated whether women with dysmenorrhoea, compared with controls, have increased sensitivity to experimentally induced deep-tissue muscle ischaemia in a body area distant from that of referred menstrual pain. The sub-maximal effort tourniquet test was used to induce forearm ischaemia in 11 women with severe dysmenorrhoea and in nine control women both during menstruation and in the follicular phase of the menstrual cycle. Von Frey hair assessments confirmed the presence of experimental ischaemia. Women rated the intensity of menstrual and ischaemic pain on a 100-mm visual analogue scale. Women with dysmenorrhoea [mean (SD): 68 (20) mm] reported significantly greater menstrual pain compared with controls [mean (SD): 2 (6) mm; p = 0.0001] during the menstruation phase. They also rated their forearm ischaemic pain as significantly greater than the controls during the menstruation [dysmenorrhoeics vs. controls mean (SD): 58 (19) mm vs. 31 (21) mm, p menstruation phase and pain-free follicular phase. These findings suggest the presence of long-lasting changes in muscle pain sensitivity in women with dysmenorrhoea. Our findings that dysmenorrhoeic women are hyperalgesic to a clinically relevant, deep-muscle ischaemic pain in areas outside of referred menstrual pain confirm other studies showing long-lasting changes in pain sensitivity outside of the painful period during menstruation. © 2014 European Pain Federation - EFIC®

In vivo imaging of induction of heat-shock protein-70 gene expression with fluorescence reflectance imaging and intravital confocal microscopy following brain ischaemia in reporter mice.

Science.gov (United States)

de la Rosa, Xavier; Santalucía, Tomàs; Fortin, Pierre-Yves; Purroy, Jesús; Calvo, Maria; Salas-Perdomo, Angélica; Justicia, Carles; Couillaud, Franck; Planas, Anna M

2013-02-01

Stroke induces strong expression of the 72-kDa heat-shock protein (HSP-70) in the ischaemic brain, and neuronal expression of HSP-70 is associated with the ischaemic penumbra. The aim of this study was to image induction of Hsp-70 gene expression in vivo after brain ischaemia using reporter mice. A genomic DNA sequence of the Hspa1b promoter was used to generate an Hsp70-mPlum far-red fluorescence reporter vector. The construct was tested in cellular systems (NIH3T3 mouse fibroblast cell line) by transient transfection and examining mPlum and Hsp-70 induction under a challenge. After construct validation, mPlum transgenic mice were generated. Focal brain ischaemia was induced by transient intraluminal occlusion of the middle cerebral artery and the mice were imaged in vivo with fluorescence reflectance imaging (FRI) with an intact skull, and with confocal microscopy after opening a cranial window. Cells transfected with the Hsp70-mPlum construct showed mPlum fluorescence after stimulation. One day after induction of ischaemia, reporter mice showed a FRI signal located in the HSP-70-positive zone within the ipsilateral hemisphere, as validated by immunohistochemistry. Live confocal microscopy allowed brain tissue to be visualized at the cellular level. mPlum fluorescence was observed in vivo in the ipsilateral cortex 1 day after induction of ischaemia in neurons, where it is compatible with penumbra and neuronal viability, and in blood vessels in the core of the infarction. This study showed in vivo induction of Hsp-70 gene expression in ischaemic brain using reporter mice. The fluorescence signal showed in vivo the induction of Hsp-70 in penumbra neurons and in the vasculature within the ischaemic core.

In vivo bioimpedance measurement of healthy and ischaemic rat brain: implications for stroke imaging using electrical impedance tomography

International Nuclear Information System (INIS)

Dowrick, T; Blochet, C; Holder, D

2015-01-01

In order to facilitate the imaging of haemorrhagic and ischaemic stroke using frequency difference electrical impedance tomography (EIT), impedance measurements of normal and ischaemic brain, and clotted blood during haemorrhage, were gathered using a four-terminal technique in an in vivo animal model, a first for ischaemic measurements. Differences of 5–10% in impedance were seen between the frequency spectrums of healthy and ischaemic brain, over the frequency range 0–3 kHz, while the spectrum of blood was predominately uniform. The implications of imaging blood/ischaemia in the brain using electrical impedance tomography are discussed, supporting the notion that it will be possible to differentiate stroke from haemorrhage. (paper)

MRI in acute cerebral ischaemia: perfusion imaging with superparamagnetic iron oxide in a rat model

International Nuclear Information System (INIS)

Forsting, M.; Reith, W.; Doerfler, A.; Kummer, R. von; Hacke, W.; Sartor, K.

1994-01-01

An imaging technique capable of detecting ischaemic cerebral injury at an early stage could improve diagnosis in acute or transient cerebral ischaemia. We compared the ability of superparamagnetically contrast-enhanced MRI and conventional T2-weighted MRI to detect ischaemic injury early after unilateral occlusion of the middle cerebral artery in 12 male Wistar rats. Permanent vessel occlusion was achieved by a transvascular approach, which has the advantage of not requiring a craniectom. At 45-60 min after the procedure, the animals had conventional T2-weighted MRI before and after administration of a superparamagnetic contrast agent (iron oxide particles). Unenhanced images were normal in all animals. After administration of iron oxide particles, the presumed ischaemic area was clearly visible, as relatively increased signal, in all animals; this high signal area corresponded to the area of ischaemic brain infarction seen on histological studies. Our results suggest that superparamagnetic iron particles may significantly reduce the interval between an ischaemic insult and the appearance of parenchymal changes on MRI. (orig./UWA)

The effect of prolonged of warm ischaemic injury on renal function in an experimental ex vivo normothermic perfusion system.

Science.gov (United States)

Hosgood, Sarah A; Shah, K; Patel, M; Nicholson, M L

2015-06-30

Donation after circulatory death (DCD) kidney transplants inevitably sustain a degree of warm ischaemic injury, which is manifested clinically as delayed graft function. The aim of this study was to define the effects of prolonged periods of warm ischaemic injury on renal function in a normothermic haemoperfused kidney model. Porcine kidneys were subjected to 15, 60, 90 (n = 6 per group) and 120 min (n = 4) of in situ warm ischaemia (WI) and then retrieved, flushed with cold preservation fluid and stored in ice for 2 h. Kidneys then underwent 3 h of normothermic reperfusion with a whole blood-based perfusate using an ex vivo circuit developed from clinical grade cardiopulmonary bypass technology. Creatinine clearance, urine output and fractional excretion of sodium deteriorated sequentially with increasing warm time. Renal function was severely compromised after 90 or 120 min of WI but haemodynamic, metabolic and histological parameters demonstrated the viability of kidneys subjected to prolonged warm ischaemia. Isolated kidney perfusion using a warm, oxygenated, red cell-based perfusate allows an accurate ex vivo assessment of the potential for recovery from warm ischaemic injury. Prolonged renal warm ischaemic injury caused a severe decrement in renal function but was not associated with tissue necrosis.

Effects of transient global ischaemia on freezing behaviour and activity in a context-dependent fear conditioning task--implications for memory investigations.

Science.gov (United States)

Henrich-Noack, Petra; Krautwald, Karla; Reymann, Klaus G; Wetzel, Wolfram

2011-07-15

Transient global ischaemia induces cell death in the CA1 layer of the hippocampus. To evaluate the functional consequences, we performed context-dependent fear conditioning. Ischaemia was induced by 2-vessel-occlusion (2VO) in gerbils. On day 6 post ischaemia or sham procedures (in control group) gerbils were placed in a test chamber and after 3 min adaption time exposed to foot-shocks (training session). On the next day the animals were placed in the same test chamber without foot-shocks (test session). As a parameter for memory performance we used the standard method of measuring the total freezing time via a cumulative time-sampling procedure during the test session. We found a significant longer total freezing time in control animals than in ischaemic animals. In addition, however, we applied a more detailed analysis of (i) quantifying the number of freezing bouts, (ii) the average duration of single freezing bouts, (iii) the activity pattern during the training and test situation and (iv) we differentially evaluated all the single time segments of the experiment. These analyses revealed that although maintenance of freezing (duration of freezing bout) was significantly lower in ischaemic animals compared to controls, the initiation of freezing (number of freezing bouts) was not significantly different between the two groups during the test session. The activity scores of ischaemic and non-ischaemic gerbils were similar during the adaption time of the training session. The foot-shock, however, induced a significantly different pattern of behaviour in the ischaemic animals, which was selectively reproduced during the test session. In conclusion, ischaemic gerbils reacted to a fearsome thread with a behavioural pattern different from unlesioned animals and they revealed this specific foot-shock induced behaviour again during the test session. This indicated that CA1 hippocampal death did not interrupt memory performance but changed expression of fear. Therefore

Defibrotide reduces infarct size in a rabbit model of experimental myocardial ischaemia and reperfusion.

Science.gov (United States)

Thiemermann, C.; Thomas, G. R.; Vane, J. R.

1989-01-01

1. Defibrotide, a single-stranded polydeoxyribonucleotide obtained from bovine lungs, has significant anti-thrombotic, pro-fibrinolytic and prostacyclin-stimulating properties. 2. The present study was designed to evaluate the effects of defibrotide on infarct size and regional myocardial blood flow in a rabbit model of myocardial ischaemia and reperfusion. 3. Defibrotide (32 mg kg-1 bolus + 32 mg kg-1 h-1, i.v.) either with or without co-administration of indomethacin (5 mg kg-1 x 2, i.v.) was administered 5 min after occlusion of the left anterior-lateral coronary artery and continued during the 60 min occlusion and subsequent 3 h reperfusion periods. 4. Defibrotide significantly attenuated the ischaemia-induced ST-segment elevation and abolished the reperfusion-related changes (R-wave reduction and Q-wave development) in the electrocardiogram. In addition, defibrotide significantly improved myocardial blood flow in normal and in ischaemic, but not in infarcted sections of the heart. The improvement in blood flow in normal perfused myocardium, but not in the ischaemic area was prevented by indomethacin. 5. Although the area at risk was similar in all animal groups studied, defibrotide treatment resulted in a 51% reduction of infarct size. Indomethacin treatment abolished the reduction of infarct size seen with defibrotide alone. 6. The data demonstrate a considerable cardioprotective effect of defibrotide in the reperfused ischaemic rabbit myocardium. This effect may be related, at least in part, to a stimulation of endogenous prostaglandin formation. Other possible mechanisms are discussed. PMID:2758223

Functional neuroimaging in the assessment of cerebral ischaemia

International Nuclear Information System (INIS)

Sartor, K.; Heiland, S.

1997-01-01

Cerebral infarct causes over 170, 000 deaths per year in the United States. Recent developments in neuroimaging are providing an insight into focal cerebral ischaemia, including its pathophysiology and the area of brain at risk. Perfusion-weighted magnetic resonance (MR) allows evaluation of the blood supply to the ischaemic area, and diffusion-weighted MR permits assessment of tissue damage. Although both functional imaging techniques require some refinement, it is likely that they will soon become part of the normal clinical routine and allow accurate characterisation of pathology. It is expected that this may eventually lead to the development of new treatments. (orig.)

Physiologic ischaemic training induces endothelial progenitor cell mobilization and myocardial angiogenesis via endothelial nitric oxide synthase related pathway in rabbits.

Science.gov (United States)

Xiao, Mingyue; Lu, Xiao; Li, Jianan; Li, Ling; Li, Yongxue

2014-04-01

Ischaemia-induced angiogenesis promises to improve neovascularization by delivery of angiogenic factors or endothelial progenitor cells (EPCs) to cardiac ischaemic areas. In order to avoid the risk of excessive myocardial ischaemia, therefore, we hypothesized that physiological ischaemic training (PIT) of normal skeletal muscle might contribute to myocardial angiogenesis via nitric oxide mediated mobilization of EPCs from the bone marrow in the established rabbit model of controllable myocardial ischaemia. The rabbits were grouped by sham-operation, myocardial ischaemia without PIT, PIT and PIT with pretreatment with the endothelial nitric oxide synthase (eNOS) inhibitor L-nitroarginine methyl ester (L-NAME). Controlled myocardial ischaemia was modelled by a water balloon constrictor implanted on the left ventricular branch in a rabbit. The PIT procedure included three cycles of 3 min of cuff inflation followed by 5 min of deflation on hind limbs of the rabbits for 4 weeks. At the endpoints, circulating EPCs (CD34/Flk-1) were measured by fluorescence-activated cell sorter; capillary density, by immunohistochemistry; blood flow, by a microsphere technique; endothelial nitric oxide synthase (eNOS) mRNA and protein, by real-time reverse transcriptase (RT)-PCR and Western blotting. The mRNA levels of eNOS were significantly higher in the PIT and L-NAME groups than in the sham-operation group (P < 0.05). Phospho-eNOS protein expression was higher in the PIT group than in the sham-operation and myocardial ischaemia without PIT groups (P < 0.05), and the effect was inhibited by L-NAME pretreatment (P < 0.05). Compared with sham-operation and myocardial ischaemia without PIT groups, the PIT group had the highest EPC count (P < 0.001), and the increase of capillary density (P < 0.01) and collateral blood flow (P < 0.05) in the ischaemic myocardium was consistent with the finding of EPC count. These effects were also inhibited by pretreatment with

Involvement of protein kinase B and mitogen-activated protein kinases in experimental normothermic liver ischaemia-reperfusion injury.

Science.gov (United States)

Cursio, R; Filippa, N; Miele, C; Van Obberghen, E; Gugenheim, J

2006-06-01

This study evaluated the role of protein kinase B (PKB), phosphatidylinositol 3-kinase (PI3-K), Bcl-2-associated death protein (BAD) and mitogen-activated protein kinases (MAPKs) in normothermic ischaemia-reperfusion (IR)-induced apoptosis in rat liver. Rats were divided into two groups that received either phosphate-buffered saline (control) or the caspase inhibitor Z-Asp-2,6-dichorobenzoyloxymethylketone (Z-Asp-cmk), injected intravenously 2 min before the induction of 120 min of normothermic liver ischaemia. Liver apoptosis was assessed by the terminal deoxyribonucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) method. PI3-K, PKB, BAD and MAPK activities were measured in ischaemic and non-ischaemic lobes at various times after reperfusion. The number of TUNEL-positive cells was significantly decreased after pretreatment with Z-Asp-cmk. In controls, PI3-K and PKB activities and BAD phosphorylation were inhibited in ischaemic liver lobes. The MAPKs (extracellular signal-regulated kinases, c-Jun N-terminal kinase and p38) showed different patterns of activation during IR. PKB activity was not modified by pretreatment with Z-Asp-cmk. Induction of apoptosis during IR liver injury might be triggered by inactivation of the antiapoptotic PI3-K-PKB pathway and activation of the proapoptotic MAPKs. Copyright (c) 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Tat-antioxidant 1 protects against stress-induced hippocampal HT-22 cells death and attenuate ischaemic insult in animal model.

Science.gov (United States)

Kim, So Mi; Hwang, In Koo; Yoo, Dae Young; Eum, Won Sik; Kim, Dae Won; Shin, Min Jea; Ahn, Eun Hee; Jo, Hyo Sang; Ryu, Eun Ji; Yong, Ji In; Cho, Sung-Woo; Kwon, Oh-Shin; Lee, Keun Wook; Cho, Yoon Shin; Han, Kyu Hyung; Park, Jinseu; Choi, Soo Young

2015-06-01

Oxidative stress-induced reactive oxygen species (ROS) are responsible for various neuronal diseases. Antioxidant 1 (Atox1) regulates copper homoeostasis and promotes cellular antioxidant defence against toxins generated by ROS. The roles of Atox1 protein in ischaemia, however, remain unclear. In this study, we generated a protein transduction domain fused Tat-Atox1 and examined the roles of Tat-Atox1 in oxidative stress-induced hippocampal HT-22 cell death and an ischaemic injury animal model. Tat-Atox1 effectively transduced into HT-22 cells and it protected cells against the effects of hydrogen peroxide (H2O2)-induced toxicity including increasing of ROS levels and DNA fragmentation. At the same time, Tat-Atox1 regulated cellular survival signalling such as p53, Bad/Bcl-2, Akt and mitogen-activate protein kinases (MAPKs). In the animal ischaemia model, transduced Tat-Atox1 protected against neuronal cell death in the hippocampal CA1 region. In addition, Tat-Atox1 significantly decreased the activation of astrocytes and microglia as well as lipid peroxidation in the CA1 region after ischaemic insult. Taken together, these results indicate that transduced Tat-Atox1 protects against oxidative stress-induced HT-22 cell death and against neuronal damage in animal ischaemia model. Therefore, we suggest that Tat-Atox1 has potential as a therapeutic agent for the treatment of oxidative stress-induced ischaemic damage. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

99mTcO(BAT-NI), a novel nitroimidazole tracer: in vivo uptake studies in ischaemic myocardium

International Nuclear Information System (INIS)

Hoffend, J.; Linke, G.; Mohammed, A.; Haberkorn, U.; Tiefenbacher, C.P.; Eisenhut, M.

2003-01-01

Myocardial perfusion single-photon emission tomography (SPET) performed with cationic technetium-99m complexes indicates ischaemic areas as cold lesions. By contrast, nitroimidazole derivatives labelled with fluorine-18 or 99m Tc have recently shown promising results for hot spot imaging of ischaemic myocardium. This study evaluates 99m TcO(BAT-NI), a new 99m Tc complex comprising the nitroimidazole ligand, 2,10-dimercapto-2, 10-dimethyl-4, 8-diaza-6-[4-(2-nitroimidazolyl)butyl]undecane, in a low-flow in vivo model of myocardial ischaemia in thoracotomised rats. To elucidate the influence of the 2-nitroimidazole group on ischaemia-induced uptake, comparisons with ligand derivatives were performed where (a) the 2-nitro group was deleted [ 99m TcO(BAT-I)], (b) the 2-nitroimidazole functionality was replaced by a Br atom [ 99m TcO(BAT-Br)] and (c) the 99m TcO(BAT) moiety was replaced by an iodine-125 iodophenoxybutyl ligand ( 125 IP-NI). The radiolabelled compounds were i.v. injected 15 min after reducing resting myocardial blood flow by 50-60% and the uptake of radioactivity was assessed 90 min post injection. Autoradiography of left ventricular short-axis slices showed median uptake ratios of ischaemic/non-ischaemic myocardium (I/N) of 3.4, 4.5 and 3.4 for 99m TcO(BAT-NI), 99m TcO(BAT-I) and 99m TcO(BAT-Br), respectively. In contrast, 125 IP-NI was not preferentially taken up by ischaemic myocardium. Accumulation of 99m TcO(BAT-NI) in ischaemic heart regions was comparable to that in the liver. Biodistribution studies showed a median uptake of 0.65% ID/g of 99m TcO(BAT-NI) in ischaemic tissue and an I/N of 3.3. On planar images of the thorax and upper abdomen the ischaemic hearts were visualised faintly; the median heart to lung count ratio for 99m TcO(BAT-NI) was 1.7, and the median heart to liver count ratio was 1.0. We conclude that uptake of 99m TcO(BAT-NI) in ischaemic myocardium does not depend on the nitroimidazole moiety but is intrinsic to the BAT complex

Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

Energy Technology Data Exchange (ETDEWEB)

Clanet, M

1987-06-18

Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO/sub 2/), oxygen extraction (EO/sub 2/) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO/sub 2/ and often a decrease in CMRO/sub 2/, whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO/sub 2/, EO/sub 2/ and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis.

Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

International Nuclear Information System (INIS)

Clanet, M.

1987-01-01

Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO 2 ), oxygen extraction (EO 2 ) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO 2 and often a decrease in CMRO 2 , whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO 2 , EO 2 and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis [fr

Prevalence of risk factors for ischaemic stroke and their treatment among a cohort of stroke patients in Dublin.

LENUS (Irish Health Repository)

McDonnell, R

2000-10-01

The majority of strokes are due to ischaemia. Risk factors include atrial fibrillation, hypertension and smoking. The incidence can be reduced by addressing these risk factors. This study examines the prevalence of risk factors and their treatment in a cohort of patients with ischaemic stroke registered on a Dublin stroke database.

Ischaemia-induced (symptomatic) migraine attacks may be more frequent than migraine-induced ischaemic insults

DEFF Research Database (Denmark)

Olesen, Jes; Friberg, L; Olsen, T S

1993-01-01

deficits after the very first migraine attack, severe atherosclerosis, risk factors for stroke, high age and no family history of migraine. In these cases the evidence indicates that thromboembolic ischaemia had triggered an attack of migraine with aura (likely symptomatic migraine). Three young females...

Preventive Treatment with Ketamine Attenuates the Ischaemia-Reperfusion Response in a Chronic Postischaemia Pain Model

Directory of Open Access Journals (Sweden)

Suryamin Liman

2015-01-01

Full Text Available Ischemia and inflammation may be pathophysiological mechanisms of complex regional pain syndrome (CRPS. Ketamine has proposed anti-inflammatory effects and has been used for treating CRPS. This study aimed to evaluate anti-inflammatory and analgesic effects of ketamine after ischaemia-reperfusion injury in a chronic postischaemia pain (CPIP model of CRPS-I. Using this model, ischemia was induced in the hindlimbs of male Sprague-Dawley rats. Ketamine, methylprednisolone, or saline was administered immediately after reperfusion. Physical effects, (oedema, temperature, and mechanical and cold allodynia in the bilateral hindpaws, were assessed from 48 hours after reperfusion. Fewer (56% rats in the ketamine group developed CPIP at the 48th hour after reperfusion (nonsignificant. Ketamine treated rats showed a significantly lower temperature in the ischaemic hindpaw compared to saline (P<0.01 and methylprednisolone (P<0.05 groups. Mechanical and cold allodynia were significantly lower in the ischaemic side in the ketamine group (P<0.05. Proinflammatory cytokines TNF-α and IL-2 were significantly lower at the 48th hour after reperfusion in ketamine and methylprednisolone groups, compared to saline (all P<0.05. In conclusion, immediate administration of ketamine after an ischaemia-reperfusion injury can alleviate pain and inflammation in the CPIP model and has potential to treat postischaemic pain.

Bilirubin provides perforator flap protection from ischaemia-reperfusion injury in a rat model: a preliminary result.

Science.gov (United States)

Kim, Sung Young; Rah, Dong Kyun; Chong, Yosep; Lee, Song Hyun; Park, Tae Hwan

2016-10-01

The use of bilirubin, a well-known and powerful antioxidant, has gained popularity in recent years because of its role in the prevention of ischaemic heart disease in patients with Gilbert's syndrome. We investigate the effects of bilirubin on ischaemia-reperfusion (I/R) injury using a rat perforator flap model. Forty-eight rats were randomly divided into two groups: experimental (bilirubin) group (n = 24) and control group (n = 24). In each group, elevated bilateral deep inferior epigastric perforator (DIEP) flaps were created. The right (no ischaemia side) and left (ischaemia side) DIEP flaps were separated according to the presence of ischaemia induction. Ischaemia was induced in anaesthetised rats by perforator clamping for 15 or 30 minutes. After surgery, the flap survival was assessed daily on postoperative days 0 to 5, and overall histological changes of DIEP flaps above the perforator were analysed at postoperative day 5. The flap survival rate in the bilirubin group was significantly higher than that in the control group at the ischaemia side following perforator clamping for 15 or 30 minutes (93·42 ± 4·48% versus 89·63 ± 3·98%, P = 0·002; and 83·96 ± 4·23% versus 36·46 ± 6·38%, P bilirubin was found to alleviate perforator flap necrosis caused by I/R injury in this experimental rat model. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Effect of the non-NMDA receptor antagonist GYKI 52466 on the microdialysate and tissue concentrations of amino acids following transient forebrain ischaemia.

Science.gov (United States)

Arvin, B; Lekieffre, D; Graham, J L; Moncada, C; Chapman, A G; Meldrum, B S

1994-04-01

The effect of the non-N-methyl-D-aspartate (non-NMDA) receptor antagonist 1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI 52466) on ischaemia-induced changes in the microdialysate and tissue concentrations of glutamate, aspartate, and gamma-aminobutyric acid (GABA) was studied in rats. Twenty minutes of four-vessel occlusion resulted in a transient increase in microdialysate levels of glutamate, aspartate, and GABA in striatum, cortex, and hippocampus. Administration of GYKI 52466 (10 mg/kg bolus + 10 mg/kg/60 min intravenously starting 20 min before onset of ischaemia) inhibited ischaemia-induced increases in microdialysate glutamate and GABA in striatum without affecting the increases in hippocampus or cortex. Twenty minutes of four-vessel occlusion resulted in immediate small decreases and larger delayed (72 h) decreases in tissue levels of glutamate and aspartate. Transient increases in tissue levels of GABA were shown in all three structures at the end of the ischaemic period. At 72 h, after the ischaemic period, significantly reduced GABA levels were observed in striatum and hippocampus. GYKI 52466, given under identical conditions as above, augmented the ischaemia-induced decrease in striatal tissue levels of glutamate and aspartate, without significantly affecting the decreases in hippocampus and cortex. Twenty minutes of ischaemia resulted in a large increase in microdialysate dopamine in striatum. GYKI 52466 failed to inhibit this increase. Kainic acid (500 microM infused through the probe for 20 min) caused increases in microdialysate glutamate and aspartate in the striatum. GYKI 52466 (10 mg/kg bolus + 10 mg/kg/60 min) completely inhibited the kainic acid-induced glutamate release. In conclusion, the action of the non-NMDA antagonist, GYKI 52466, in the striatum is different from that in the cortex and hippocampus. The inhibition by GYKI 52466 of ischaemia-induced and kainate-induced increases in microdialysate

Sodium transport through the cerebral sodium-glucose transporter exacerbates neuron damage during cerebral ischaemia.

Science.gov (United States)

Yamazaki, Yui; Harada, Shinichi; Wada, Tetsuyuki; Yoshida, Shigeru; Tokuyama, Shogo

2016-07-01

We recently demonstrated that the cerebral sodium-glucose transporter (SGLT) is involved in postischaemic hyperglycaemia-induced exacerbation of cerebral ischaemia. However, the associated SGLT-mediated mechanisms remain unclear. Thus, we examined the involvement of cerebral SGLT-induced excessive sodium ion influx in the development of cerebral ischaemic neuronal damage. [Na+]i was estimated according to sodium-binding benzofuran isophthalate fluorescence. In the in vitro study, primary cortical neurons were prepared from fetuses of ddY mice. Primary cortical neurons were cultured for 5 days before each treatment with reagents, and these survival rates were assessed using biochemical assays. In in vivo study, a mouse model of focal ischaemia was generated using middle cerebral artery occlusion (MCAO). In these experiments, treatment with high concentrations of glucose induced increment in [Na+]i, and this phenomenon was suppressed by the SGLT-specific inhibitor phlorizin. SGLT-specific sodium ion influx was induced using a-methyl-D-glucopyranoside (a-MG) treatments, which led to significant concentration-dependent declines in neuronal survival rates and exacerbated hydrogen peroxide-induced neuronal cell death. Moreover, phlorizin ameliorated these effects. Finally, intracerebroventricular administration of a-MG exacerbated the development of neuronal damage induced by MCAO, and these effects were ameliorated by the administration of phlorizin. Hence, excessive influx of sodium ions into neuronal cells through cerebral SGLT may exacerbate the development of cerebral ischaemic neuronal damage. © 2016 Royal Pharmaceutical Society.

Ischaemic memory imaging using metabolic radiopharmaceuticals: overview of clinical settings and ongoing investigations.

Science.gov (United States)

Yoshinaga, Keiichiro; Naya, Masanao; Shiga, Tohru; Suzuki, Eriko; Tamaki, Nagara

2014-02-01

"Ischaemic memory" is defined as a prolonged functional and/or biochemical alteration remaining after a particular episode of severe myocardial ischaemia. The biochemical alteration has been reported as metabolic stunning. Metabolic imaging has been used to detect the footprint left by previous ischaemic episodes evident due to delayed recovery of myocardial metabolism (persistent dominant glucose utilization with suppression of fatty acid oxidation). β-Methyl-p-[(123)I]iodophenylpentadecanoic acid (BMIPP) is a single-photon emission computed tomography (SPECT) radiotracer widely used for metabolic imaging in clinical settings in Japan. In patients with suspected coronary artery disease but no previous myocardial infarction, BMIPP has shown acceptable diagnostic accuracy. In particular, BMIPP plays an important role in the identification of prior ischaemic insult in patients arriving at emergency departments with acute chest pain syndrome. Recent data also show the usefulness of (123)I-BMIPP SPECT for predicting cardiovascular events in patients undergoing haemodialysis. Similarly, SPECT or PET imaging with (18)F-FDG injected during peak exercise or after exercise under fasting conditions shows an increase in FDG uptake in postischaemic areas. This article will overview the roles of ischaemic memory imaging both under established indications and in ongoing investigations.

Ischaemic memory imaging using metabolic radiopharmaceuticals: overview of clinical settings and ongoing investigations

International Nuclear Information System (INIS)

Yoshinaga, Keiichiro; Naya, Masanao; Shiga, Tohru; Suzuki, Eriko; Tamaki, Nagara

2014-01-01

''Ischaemic memory'' is defined as a prolonged functional and/or biochemical alteration remaining after a particular episode of severe myocardial ischaemia. The biochemical alteration has been reported as metabolic stunning. Metabolic imaging has been used to detect the footprint left by previous ischaemic episodes evident due to delayed recovery of myocardial metabolism (persistent dominant glucose utilization with suppression of fatty acid oxidation). β-Methyl-p-[ 123 I]iodophenylpentadecanoic acid (BMIPP) is a single-photon emission computed tomography (SPECT) radiotracer widely used for metabolic imaging in clinical settings in Japan. In patients with suspected coronary artery disease but no previous myocardial infarction, BMIPP has shown acceptable diagnostic accuracy. In particular, BMIPP plays an important role in the identification of prior ischaemic insult in patients arriving at emergency departments with acute chest pain syndrome. Recent data also show the usefulness of 123 I-BMIPP SPECT for predicting cardiovascular events in patients undergoing haemodialysis. Similarly, SPECT or PET imaging with 18 F-FDG injected during peak exercise or after exercise under fasting conditions shows an increase in FDG uptake in postischaemic areas. This article will overview the roles of ischaemic memory imaging both under established indications and in ongoing investigations. (orig.)

Effects of defibrotide, a novel oligodeoxyribonucleotide, on ischaemia and reperfusion injury of the rat liver.

Science.gov (United States)

Kim, Kwang Joon; Shin, Yong Kyoo; Song, Jin Ho; Oh, Byung Kwon; Choi, Myung Sup; Sohn, Uy Dong

2002-02-01

1. The purpose of this study was to investigate the protective effects of defibrotide, a single-stranded polydeoxyribonucleotide, on ischaemia-reperfusion injury to the liver using a rat model. 2. Ischaemia of the left and median lobes was created by total inflow occlusion for 30 min followed by 60 min of reperfusion. Hepatic injury was assessed by the release of liver enzymes (alanine transferase, ALT and lactic dehydrogenase, LDH). Hepatic oxidant stress was measured by superoxide production, lipid peroxidation and nitrite/nitrate formation. Leukocyte-endothelium interaction and Kupffer cell mobilization were quantified by measuring hepatic myeloperoxidase (MPO), polymorphonuclear leukocyte adherence to superior mesenteric artery (SMA) and immunostaining of Kupffer cell. 3. Defibrotide treatment resulted in a significant inhibition of postreperfusion superoxide generation, lipid peroxidation, serum ALT activity, serum LDH activity, MPO activity, serum nitrite/nitrate level, leukocyte adherence to SMA, and Kupffer cell mobilization, indicating a significant attenuation of hepatic dysfunction. 4. A significant correlation existed between liver ischaemia/reperfusion and hepatic injury, suggesting that liver ischaemia/reperfusion injury is mediated predominantly by generation of oxygen free radicals and mobilization of Kupffer cells. 5. We conclude that defibrotide significantly protects the liver against liver ischaemia/reperfusion injury by interfering with Kupffer cell mobilization and formation of oxygen free radicals. This study provides strong evidence that defibrotide has important beneficial effects on acute inflammatory tissue injury such as that occurring in the reperfusion of the ischaemic liver.

Effects of salicylic acid on post-ischaemic ventricular function and purine efflux in isolated mouse hearts.

Science.gov (United States)

Farthing, Don; Gehr, Lynne; Karnes, H Thomas; Sica, Domenic; Gehr, Todd; Larus, Terri; Farthing, Christine; Xi, Lei

2007-01-01

Acetyl salicylic acid (aspirin) is one of the most widely used drugs in the world. Various plasma concentrations of aspirin and its predominant metabolite, salicylic acid, are required for its antiarthritic (1.5-2.5 mM), anti-inflammatory (0.5-5.0 mM) or antiplatelet (0.18-0.36 mM) actions. A recent study demonstrated the inhibitory effects of both aspirin and salicylic acid on oxidative phosphorylation and ATP synthesis in isolated rat cardiac mitochondria in a dose-dependent manner (0-10 mM concentration range). In this context, the present study was conducted to determine the effects of salicylic acid on inosine efflux (a potential biomarker of acute cardiac ischaemia) as well as cardiac contractile function in the isolated mouse heart following 20 min of zero-flow global ischaemia. Inosine efflux was found at significantly higher concentrations in ischaemic hearts perfused with Krebs buffer fortified with 1.0 mM salicylic acid compared with those without salicylic acid (12575+/-3319 vs. 1437+/-348 ng ml(-1) min(-1), mean+/-SEM, n=6 per group, psalicylic acid potentiates 8.8-fold ATP nucleotide purine catabolism into its metabolites (e.g. inosine, hypoxanthine). Salicylic acid (0.1 or 1.0 mM) did not appreciably inhibit purine nucleoside phosphorylase (the enzyme converts inosine to hypoxanthine) suggesting the augmented inosine efflux was due to the salicylic acid effect on upstream elements of cellular respiration. Whereas post-ischaemic cardiac function was further depressed by 1.0 mM salicylic acid, perfusion with 0.1 mM salicylic acid led to a remarkable functional improvement despite moderately increased inosine efflux (2.7-fold). We conclude that inosine is a sensitive biomarker for detecting cardiac ischaemia and salicylic acid-induced effects on cellular respiration. However, the inosine efflux level appears to be a poor predictor of the individual post-ischaemic cardiac functional recovery in this ex vivo model.

Prevalence of silent myocardial ischaemia during exercise stress testing. Its relation to effort tolerance and myocardial perfusion abnormalities.

Science.gov (United States)

Fragasso, G; Sciammarella, M G; Rossetti, E E; Xuereb, R G; Xuereb, M; Bonetti, F; Carandente, O M; Margonato, A; Chierchia, S L

1992-07-01

The number of underperfused myocardial segments, the extent of coronary artery disease and the severity of impairment of coronary flow reserve were compared in 147 consecutive patients exhibiting painful or painless ischaemic ST segment depression on exercise testing. Of 147 patients, only 61 (41%) experienced angina (group 1) whilst 86 (59%) did not (group 2). In the two groups coronary disease was comparable for both extent and distribution, and neither the location of transient perfusion defects nor their relation to areas of old myocardial necrosis appeared to influence the presence or absence of chest pain. However, exercise duration, exercise time and rate-pressure product at the beginning of ischaemia were lower in group 1. Furthermore, a greater proportion of asymptomatic patients had only one ischaemic segment on 99mTc-MIBI perfusion scintigraphy. We conclude that: (1) in patients with effort angina and coronary disease, the incidence of electrocardiographic silent ischaemic events induced by exercise is similar to that observed in studies based on continuous ECG monitoring. (2) Exertional angina is more frequently associated with greater ischaemic areas and with more severe degrees of impairment of residual coronary flow reserve. (3) The presence of an old myocardial infarction does not appear to influence the incidence of ischaemic cardiac pain.

Medium intensity oral anticoagulants versus aspirin after cerebral ischaemia of arterial origin (ESPRIT): a randomised controlled trial.

Science.gov (United States)

Halkes, P H A; van Gijn, J; Kappelle, L J; Koudstaal, P J; Algra, A

2007-02-01

Oral anticoagulants are better than aspirin for secondary prevention after myocardial infarction and after cerebral ischaemia in combination with non-rheumatic atrial fibrillation. The European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) aimed to determine whether oral anticoagulation with medium intensity is more effective than aspirin in preventing future vascular events in patients with transient ischaemic attack or minor stroke of presumed arterial origin. In this international, multicentre trial, patients were randomly assigned within 6 months after a transient ischaemic attack or minor stroke of presumed arterial origin either anticoagulants (target INR range 2.0-3.0; n=536) or aspirin (30-325 mg daily; n=532). The primary outcome was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever occurred first. In a post hoc analysis anticoagulants were compared with the combination of aspirin and dipyridamole (200 mg twice daily). Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with ClinicalTrials.gov (NCT00161070). The anticoagulants versus aspirin comparison of ESPRIT was prematurely ended because ESPRIT reported previously that the combination of aspirin and dipyridamole was more effective than aspirin alone. Mean follow-up was 4.6 years (SD 2.2). The mean achieved INR was 2.57 (SD 0.86). A primary outcome event occurred in 99 (19%) patients on anticoagulants and in 98 (18%) patients on aspirin (hazard ratio [HR] 1.02, 95% CI 0.77-1.35). The HR for ischaemic events was 0.73 (0.52-1.01) and for major bleeding complications 2.56 (1.48-4.43). The HR for the primary outcome event comparing anticoagulants with the combination treatment of aspirin and dipyridamole was 1.31 (0.98-1.75). Oral

The kinetics of {beta}-methyl-substituted labelled fatty acids in ischaemic myocardium: an analysis in man and with a blood-perfused isolated heart model

Energy Technology Data Exchange (ETDEWEB)

Marie, P.Y.; Ayalew, A.; Hassan, N.; Olivier, P.; Karcher, G.; Bertrand, A. [Dept. of Nuclear Medicine, UPRES EA, Nancy (France); Menu, P. [Dept. of Hematology and Physiology, University Henri Poincare, Nancy (France); Angioi, M.; Mertes, P.M.; Danchin, N. [Dept. of Cardiology, UPRES EA, Nancy (France); Fagret, D. [Dept. of Nuclear Medicine, Grenoble (France); Pasqualini, R. [CIS Bio International, Gif-sur-Yvette (France)

1999-05-01

{beta}-Methyl-substituted free fatty acids (FFAs) have been developed for myocardial single-photon emission tomography (SPET) imaging, but little is known about their kinetics in ischaemic conditions. The aim of this study was to determine the changes in the myocardial kinetics of a {beta}-methyl-branched FFA, [{sup 123}I]16-iodo-3-methyl-hexadecanoic acid (MIHA), under ischaemic conditions. The kinetics of MIHA were analysed: (a) using a blood-perfused isolated heart model subjected to moderate ischaemia (50% flow reduction) and (b) in patients who had an exercise thallium-201 SPET defect corresponding to either necrotic (n = 13) or chronically ischaemic and viable (n = 15) myocardium, and who underwent two consecutive SPET studies after MIHA injection. In animals, the myocardial early retention fraction of MIHA, but not its clearance rate, was dependent on coronary flow, the early retention fraction being higher in ischaemic than in normoxic conditions (0.24{+-}0.10 vs 0.14{+-}0.04, P = 0.004). In the patient SPET studies, the uptake of MIHA calculated in ischaemic and viable areas (G1: 74%{+-}9% of maximal left ventricular value) was different from that calculated in necrotic (G2: 59%{+-}7%, P<0.001) or normal (G3: 88{+-}6%, P<0.001) areas. By contrast, MIHA-clearance calculated between the two consecutive SPET studies was not different in G1, G2 and G3. Unlike in the case of other FFAs, the myocardial clearance of MIHA is not decreased by ischaemia. However, the early retention of MIHA is increased in the case of a moderate reduction in coronary flow, a property which might help in the detection of viability in chronically ischaemic myocardium. (orig.) With 5 figs., 3 tabs., 44 refs.

Case Report: Ischaemic appendicitis post mesenteric biopsy [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Marianna Zukiwskyj

2016-01-01

Full Text Available A common indication for laparoscopic mesenteric lymph node biopsy is to provide a tissue diagnosis in the absence of palpable peripheral nodes via a minimally invasive approach.  There are no reports to date of ischaemia to the appendix as a complication of this procedure.   We report the case of a 34-year-old lady who underwent a mesenteric biopsy for a lesion found incidentally on CT to investigate longstanding abdominal pain, and 2 days later required an appendicectomy for ischaemic appendicitis.

Ischaemic memory imaging using metabolic radiopharmaceuticals: overview of clinical settings and ongoing investigations

Energy Technology Data Exchange (ETDEWEB)

Yoshinaga, Keiichiro [Hokkaido University Graduate School of Medicine, Department of Molecular Imaging, Sapporo (Japan); Naya, Masanao [Hokkaido University Graduate School of Medicine, Department of Cardiology, Sapporo (Japan); Shiga, Tohru; Suzuki, Eriko; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan)

2014-02-15

''Ischaemic memory'' is defined as a prolonged functional and/or biochemical alteration remaining after a particular episode of severe myocardial ischaemia. The biochemical alteration has been reported as metabolic stunning. Metabolic imaging has been used to detect the footprint left by previous ischaemic episodes evident due to delayed recovery of myocardial metabolism (persistent dominant glucose utilization with suppression of fatty acid oxidation). β-Methyl-p-[{sup 123}I]iodophenylpentadecanoic acid (BMIPP) is a single-photon emission computed tomography (SPECT) radiotracer widely used for metabolic imaging in clinical settings in Japan. In patients with suspected coronary artery disease but no previous myocardial infarction, BMIPP has shown acceptable diagnostic accuracy. In particular, BMIPP plays an important role in the identification of prior ischaemic insult in patients arriving at emergency departments with acute chest pain syndrome. Recent data also show the usefulness of {sup 123}I-BMIPP SPECT for predicting cardiovascular events in patients undergoing haemodialysis. Similarly, SPECT or PET imaging with {sup 18}F-FDG injected during peak exercise or after exercise under fasting conditions shows an increase in FDG uptake in postischaemic areas. This article will overview the roles of ischaemic memory imaging both under established indications and in ongoing investigations. (orig.)

Role of peripheral sigma-1 receptors in ischaemic pain: Potential interactions with ASIC and P2X receptors.

Science.gov (United States)

Kwon, S G; Roh, D H; Yoon, S Y; Choi, S R; Choi, H S; Moon, J Y; Kang, S Y; Kim, H W; Han, H J; Beitz, A J; Oh, S B; Lee, J H

2016-04-01

The role of peripheral sigma-1 receptors (Sig-1Rs) in normal nociception and in pathologically induced pain conditions has not been thoroughly investigated. Since there is mounting evidence that Sig-1Rs modulate ischaemia-induced pathological conditions, we investigated the role of Sig-1Rs in ischaemia-induced mechanical allodynia (MA) and addressed their possible interaction with acid-sensing ion channels (ASICs) and P2X receptors at the ischaemic site. We used a rodent model of hindlimb thrombus-induced ischaemic pain (TIIP) to investigate their role. Western blot was performed to observe changes in Sig-1R expression in peripheral nervous tissues. MA was measured after intraplantar (i.pl.) injections of antagonists for the Sig-1, ASIC and P2X receptors in TIIP rats or agonists of each receptor in naïve rats. Sig-1R expression significantly increased in skin, sciatic nerve and dorsal root ganglia at 3 days post-TIIP surgery. I.pl. injections of the Sig-1R antagonist, BD-1047 on post-operative days 0-3 significantly attenuated the development of MA during the induction phase, but had no effect on MA when given during the maintenance phase (days 3-6 post-surgery). BD-1047 synergistically increased amiloride (an ASICs blocker)- and TNP-ATP (a P2X antagonist)-induced analgesic effects in TIIP rats. In naïve rats, i.pl. injection of Sig-1R agonist PRE-084 alone did not produce MA; but it did induce MA when co-administered with either an acidic pH solution or a sub-effective dose of αβmeATP. Peripheral Sig-1Rs contribute to the induction of ischaemia-induced MA via facilitation of ASICs and P2X receptors. Thus, peripheral Sig-1Rs represent a novel therapeutic target for the treatment of ischaemic pain. © 2015 European Pain Federation - EFIC®

Acute lower extremity ischaemia

African Journals Online (AJOL)

Acute lower extremity ischaemia. Acute lower limb ischaemia is a surgical emergency. ... is ~1.5 cases per 10 000 persons per year. Acute ischaemia ... Table 2. Clinical features discriminating embolic from thrombotic ALEXI. Clinical features.

Prevention of Renal Injury After Induction of Ozone Tolerance in Rats Submitted to Warm Ischaemia

Directory of Open Access Journals (Sweden)

E. Barber

1999-01-01

Full Text Available On the basis that ozone (O3 can upregulate cellular antioxidant enzymes, a morphological, biochemical and functional renal study was performed in rats undergoing a prolonged treatment with O3 before renal ischaemia. Rats were divided into four groups: (1 control, a medial abdominal incision was performed to expose the kidneys; (2 ischaemia, in animals undergoing a bilateral renal ischaemia (30 min, with subsequent reperfusion (3 h; (3 O3 + ischaemia, as group 2, but with previous treatment with O3 (0.5 mg/kg per day given in 2.5 ml O2 via rectal administration for 15 treatments; (4 O2 + ischaemia, as group 3, but using oxygen (O2 alone. Biochemical parameters as fructosamine level, phospholipase A, and superoxide dismutases (SOD activities, as well as renal plasma flow (RPF and glomerular filtration rate (GFR, were measured by means of plasma clearance of p-amino-hippurate and inulin, respectively. In comparison with groups 1 and 3, the RPF and GFR were significantly decreased in groups 2 and 4. Interestingly, renal homogenates of the latter groups yielded significantly higher values of phospholipase A activity and fructosamine level in comparison with either the control (1 and the O3 (3 treated groups. Moreover renal SOD activity showed a significant increase in group 3 without significant differences among groups 1, 2 and 4. Morphological alterations of the kidney were present in 100%, 88% and 30% of the animals in groups 2, 4 and 3, respectively. It is proposed that the O3 protective effect can be ascribed to the substantial possibility of upregulating the antioxidant defence system capable of counteracting the damaging effect of ischaemia. These findings suggest that, whenever possible, ozone preconditioning may represent a prophylactic approach for minimizing renal damage before transplantation.

Angiopoietin-2 impairs collateral artery growth associated with the suppression of the infiltration of macrophages in mouse hindlimb ischaemia

Directory of Open Access Journals (Sweden)

Xiaoyong Tan

2016-10-01

Full Text Available Abstract Background Angiopoietin-2 (Ang-2, a ligand of the Tie-2 receptor, plays an important role in maintaining endothelial cells and in destabilizing blood vessels. Collateral artery growth (arteriogenesis is a key adaptive response to arterial occlusion. It is unknown whether the destabilization of blood vessels by Ang-2 can affect arteriogenesis and modulate mononuclear cell function. This study aimed to investigate the effects of Ang-2 on collateral artery growth. Methods Hindlimb ischaemia model was produced in C57BL/6 mice by femoral artery ligation. Blood flow perfusion was measured using a laser Doppler perfusion imager quantitative RT-PCR analysis was applied to identify the level of angiogenic factors. Results After the induction of hindlimb ischaemia, blood flow recovery was impaired in mice treated with recombinant Ang-2 protein; this was accompanied by a reduction of peri-collateral macrophage infiltration. In addition, quantitative RT-PCR analysis revealed that Ang-2 treatment decreased monocyte chemotactic protein-1 (MCP-1, platelet-derived growth factor-BB (PDGF-BB mRNA levels in ischaemic adductor muscles. Ang-2 can lead to macrophage M1/M2 polarization shift inhibition in the ischaemic muscles. Furthermore, Ang-2 reduced the in vitro inflammatory response in macrophages and vascular cells involved in arteriogenesis. Conclusions Our results demonstrate that Ang-2 is essential for efficient arteriogenesis, which controls macrophage infiltration.

Myocardial metabolism of 123I-BMIPP during low-flow ischaemia in an experimental model: comparison with myocardial blood flow and 18F-FDG

International Nuclear Information System (INIS)

Hosokawa, Ryohei; Nohara, Ryuji; Hirai, Taku; Fujita, Masatoshi; Sasayama, Shigetake; Fujibayashi, Yasuhisa; Magata, Yasuhiro; Tadamura, Eiji; Konishi, Junji

2001-01-01

Risk stratification of coronary artery disease may provide a basis for selection of treatment to prevent myocardial events and to assist functional recovery. Iodine-123 (ρ-iodophenyl)-3-R,S-methylpentadecanoic acid ( 123 I-BMIPP) is a radioiodinated fatty acid analogue for single-photon emission tomographic (SPET) imaging, and several reports have demonstrated that the abnormal uptake of 123 I-BMIPP is associated with wall motion abnormality and severe coronary artery stenosis. Clarification of the contribution of fatty acids to myocardial metabolism would be highly valuable in recognising this critical condition. In this study, we investigated the myocardial uptake of 123 I-BMIPP under low-flow ischaemia, and compared it with the uptake of fluorine-18 fluorodeoxyglucose ( 18 F-FDG). Using open chest dogs, the flow of the left anterior descending coronary artery was controlled using a pneumatic occluder in order to maintain a 30%-40% reduction of Doppler flow. 123 I-BMIPP and 18 F-FDG were injected into the left atrium after 90 min of ischaemia (protocols 1 and 3). Canine hearts were excised after 120 min of ischaemia for the measurement of radioactivity. In protocol 2, 123 I-BMIPP alone was injected and hearts were excised 8 min after the injection. A time-course biopsy study was also performed at the same time (protocol 3). Wall thickening was evaluated using a wall tracker module. The uptake of 18 F-FDG increased significantly in the ischaemic region (232%±135% vs non-ischaemic, P 18 F-FDG did not correlate well with the severity of MBF. On the other hand, 123 I-BMIPP uptake decreased gradually (78.9%±23.6%, P 123 I-BMIPP was associated not only with wall motion abnormality but also with the severity of MBF. In the biopsy study (protocol 3), the radioactivity of either 123 I-BMIPP or 18 F-FDG correlated well with the MBF at the time of tracer injection and was similar to post-mortem analysis. It is concluded that 18 F-FDG is a valid tool for identifying

Epigenomic and transcriptomic approaches in the post-genomic era : Path to novel targets for diagnosis and therapy of the ischaemic heart? Position Paper of the European Society of Cardiology Working Group on Cellular Biology of the Heart

NARCIS (Netherlands)

Perrino, Cinzia; Barabási, Albert Laszló; Condorelli, Gianluigi; Davidson, Sean Michael; De Windt, Leon J.; Dimmeler, Stefanie; Engel, Felix Benedikt; Hausenloy, Derek John; Hill, Joseph Addison; Van Laake, Linda Wilhelmina; Lecour, Sandrine; Leor, Jonathan; Madonna, Rosalinda; Mayr, Manuel; Prunier, Fabrice; Sluijter, Joost Petrus Geradus; Schulz, Rainer; Thum, Thomas; Ytrehus, Kirsti; Ferdinandy, Péter

2017-01-01

Despite advances in myocardial reperfusion therapies, acute myocardial ischaemia/reperfusion injury and consequent ischaemic heart failure represent the number one cause of morbidity and mortality in industrialized societies. Although different therapeutic interventions have been shown beneficial in

Altered myocardial perfusion during dobutamine stress testing in silent versus symptomatic myocardial ischaemia assessed by quantitative MIBI SPET imaging

International Nuclear Information System (INIS)

Elhendy, A.; Geleijnse, M.L.; Roelandt, J.R.T.C.; Cornel, J.H.; Domburg, R.T van; Reijs, A.E.M.; Nierop, P.R.; Fioretti, P.M.

1996-01-01

The aim of the study was to compare the extent and severity of reversible underperfusion in silent versus painful myocardial ischaemia during the dobutamine stress test. A consecutive series of 85 patients with significant coronary artery disease and reversible perfusion defects on technetium-99m methoxyisobutylisonitrile single-photon emission tomography performed at rest and during high-dose dobutamine stress (up to 40 μg kg -1 min -1 ) were studied. The left ventricle was divided into six segments. An ischaemic perfusion score was derived quantitatively by subtracting the rest from the stress defect score. Patients with multivessel disease had a higher ischaemic score (610±762 vs 310±411, P<0.05) and a higher number of reversible perfusion defects (2.1±1.2 vs 1.1±0.8, P<0.01) than patients with single-vessel disease. Typical angina occurred in 37 patients (44%) during the test. There was no significant difference between patients with and patients without angina with respecft to age, gender, peak rate-pressure product, prevalence of previous myocardial infarction, diabetes mellitus, multivessel disease or number of stenotic coronary arteries. Stress, rest and ischaemic scores as well as the number and distribution of reversible defects were not different in patients with and patients without angina. Patients with angina more frequently had a history of typical angina before the test (43% vs 17%, P<0.01) and ST-segment depression during the test (54% vs 25%, P<0.01). It is concluded that in patients with coronary artery disease and ischaemia detected by dobutamine scintigraphy, the extent and severity of coronary artery disease and myocardial perfusion abnormalities are similar with or without angina during stess testing. (orig.)

Interventions to reduce tourniquet-related ischaemic damage in orthopaedic surgery

DEFF Research Database (Denmark)

Halladin, N L; Zahle, F V; Rosenberg, J

2014-01-01

-related oxidative damage in adults undergoing orthopaedic surgery, and the possible relationship between biochemical oxidative stress markers and postoperative clinical outcomes. Seventeen randomised controlled studies were included in the qualitative synthesis. Most trials were of low methodological quality...... and postoperative clinical outcomes should be further investigated in the future....... and only two studies reported postoperative clinical outcomes. Nine studies tested anaesthetics (propofol, dexmedetomidine, ketamine, and spinal anaesthesia); four studies tested antioxidants (N-acetyl-cysteine, vitamin C, and mannitol); and four studies tested ischaemic pre-conditioning. Fifteen studies...

Remote ischaemic conditioning before hospital admission, as a complement to angioplasty, and effect on myocardial salvage in patients with acute myocardial infarction: a randomised trial.

Science.gov (United States)

Bøtker, Hans Erik; Kharbanda, Rajesh; Schmidt, Michael R; Bøttcher, Morten; Kaltoft, Anne K; Terkelsen, Christian J; Munk, Kim; Andersen, Niels H; Hansen, Troels M; Trautner, Sven; Lassen, Jens Flensted; Christiansen, Evald Høj; Krusell, Lars R; Kristensen, Steen D; Thuesen, Leif; Nielsen, Søren S; Rehling, Michael; Sørensen, Henrik Toft; Redington, Andrew N; Nielsen, Torsten T

2010-02-27

Remote ischaemic preconditioning attenuates cardiac injury at elective surgery and angioplasty. We tested the hypothesis that remote ischaemic conditioning during evolving ST-elevation myocardial infarction, and done before primary percutaneous coronary intervention, increases myocardial salvage. 333 consecutive adult patients with a suspected first acute myocardial infarction were randomly assigned in a 1:1 ratio by computerised block randomisation to receive primary percutaneous coronary intervention with (n=166 patients) versus without (n=167) remote conditioning (intermittent arm ischaemia through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff). Allocation was concealed with opaque sealed envelopes. Patients received remote conditioning during transport to hospital, and primary percutaneous coronary intervention in hospital. The primary endpoint was myocardial salvage index at 30 days after primary percutaneous coronary intervention, measured by myocardial perfusion imaging as the proportion of the area at risk salvaged by treatment; analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00435266. 82 patients were excluded on arrival at hospital because they did not meet inclusion criteria, 32 were lost to follow-up, and 77 did not complete the follow-up with data for salvage index. Median salvage index was 0.75 (IQR 0.50-0.93, n=73) in the remote conditioning group versus 0.55 (0.35-0.88, n=69) in the control group, with median difference of 0.10 (95% CI 0.01-0.22; p=0.0333); mean salvage index was 0.69 (SD 0.27) versus 0.57 (0.26), with mean difference of 0.12 (95% CI 0.01-0.21; p=0.0333). Major adverse coronary events were death (n=3 per group), reinfarction (n=1 per group), and heart failure (n=3 per group). Remote ischaemic conditioning before hospital admission increases myocardial salvage, and has a favourable safety profile. Our findings merit a larger trial to establish the effect of remote

Does aetiology of neonatal encephalopathy and hypoxic-ischaemic encephalopathy influence the outcome of treatment?

Science.gov (United States)

Mcintyre, Sarah; Badawi, Nadia; Blair, Eve; Nelson, Karin B

2015-04-01

Neonatal encephalopathy, a clinical syndrome affecting term-born and late preterm newborn infants, increases the risk of perinatal death and long-term neurological morbidity, especially cerebral palsy. With the advent of therapeutic hypothermia, a treatment designed for hypoxic or ischaemic injury, associated mortality and morbidity rates have decreased. Unfortunately, only about one in eight neonates (95% confidence interval) who meet eligibility criteria for therapeutic cooling apparently benefit from the treatment. Studies of infants in representative populations indicate that neonatal encephalopathy is a potential result of a variety of antecedents and that asphyxial complications at birth account for only a small percentage of neonatal encephalopathy. In contrast, clinical case series suggest that a large proportion of neonatal encephalopathy is hypoxic or ischaemic, and trials of therapeutic hypothermia are specifically designed to include only infants exposed to hypoxia or ischaemia. This review addresses the differences, definitional and methodological, between infants studied and investigations undertaken, in population studies compared with cooling trials. It raises the question if there may be subgroups of infants with a clinical diagnosis of hypoxic-ischaemic encephalopathy (HIE) in whom the pathobiology of neonatal neurological depression is not fundamentally hypoxic or ischaemic and, therefore, for whom cooling may not be beneficial. In addition, it suggests approaches to future trials of cooling plus adjuvant therapy that may contribute to further improvement of care for these vulnerable neonates. © The Authors. Journal compilation © 2015 Mac Keith Press.

MicroRNA-150 protects the mouse heart from ischaemic injury by regulating cell death

Science.gov (United States)

Tang, Yaoping; Wang, Yongchao; Park, Kyoung-mi; Hu, Qiuping; Teoh, Jian-peng; Broskova, Zuzana; Ranganathan, Punithavathi; Jayakumar, Calpurnia; Li, Jie; Su, Huabo; Tang, Yaoliang; Ramesh, Ganesan; Kim, Il-man

2015-01-01

Aims Cardiac injury is accompanied by dynamic changes in the expression of microRNAs (miRs). For example, miR-150 is down-regulated in patients with acute myocardial infarction, atrial fibrillation, dilated and ischaemic cardiomyopathy as well as in various mouse heart failure (HF) models. Circulating miR-150 has been recently proposed as a better biomarker of HF than traditional clinical markers such as brain natriuretic peptide. We recently showed using the β-arrestin-biased β-blocker, carvedilol that β-arrestin1-biased β1-adrenergic receptor cardioprotective signalling stimulates the processing of miR-150 in the heart. However, the potential role of miR-150 in ischaemic injury and HF is unknown. Methods and results Here, we show that genetic deletion of miR-150 in mice causes abnormalities in cardiac structural and functional remodelling after MI. The cardioprotective roles of miR-150 during ischaemic injury were in part attributed to direct repression of the pro-apoptotic genes egr2 (zinc-binding transcription factor induced by ischaemia) and p2x7r (pro-inflammatory ATP receptor) in cardiomyocytes. Conclusion These findings reveal a pivotal role for miR-150 as a regulator of cardiomyocyte survival during cardiac injury. PMID:25824147

Perioperative ischaemia-induced liver injury and protection strategies: An expanding horizon for anaesthesiologists

Directory of Open Access Journals (Sweden)

Chandra Kant Pandey

2013-01-01

Full Text Available Liver resection is an effective modality of treatment in patients with primary liver tumour, metastases from colorectal cancers and selected benign hepatic diseases. Its aim is to resect the grossly visible tumour with clear margins and to ensure that the remnant liver mass has sufficient function which is adequate for survival. With the advent of better preoperative imaging, surgical techniques and perioperative management, there is an improvement in the outcome with decreased mortality. This decline in postoperative mortality after hepatic resection has encouraged surgeons for more radical liver resections, leaving behind smaller liver remnants in a bid to achieve curative surgeries. But despite advances in diagnostic, imaging and surgical techniques, postoperative liver dysfunction of varied severity including death due to liver failure is still a serious problem in such patients. Different surgical and non-surgical techniques like reducing perioperative blood loss and consequent decreased transfusions, vascular occlusion techniques (intermittent portal triad clamping and ischaemic preconditioning, administration of pharmacological agents (dextrose, intraoperative use of methylprednisolone, trimetazidine, ulinastatin and lignocaine and inhaled anaesthetic agents (sevoflurane and opioids (remifentanil have demonstrated the potential benefit and minimised the adverse effects of surgery. In this article, the authors reviewed the surgical and non-surgical measures that could be adopted to minimise the risk of postoperative liver failure following liver surgeries with special emphasis on ischaemic and pharmacological preconditioning which can be easily adapted clinically.

Plasticity in the Neonatal Brain following Hypoxic-Ischaemic Injury

Directory of Open Access Journals (Sweden)

Eridan Rocha-Ferreira

2016-01-01

Full Text Available Hypoxic-ischaemic damage to the developing brain is a leading cause of child death, with high mortality and morbidity, including cerebral palsy, epilepsy, and cognitive disabilities. The developmental stage of the brain and the severity of the insult influence the selective regional vulnerability and the subsequent clinical manifestations. The increased susceptibility to hypoxia-ischaemia (HI of periventricular white matter in preterm infants predisposes the immature brain to motor, cognitive, and sensory deficits, with cognitive impairment associated with earlier gestational age. In term infants HI causes selective damage to sensorimotor cortex, basal ganglia, thalamus, and brain stem. Even though the immature brain is more malleable to external stimuli compared to the adult one, a hypoxic-ischaemic event to the neonate interrupts the shaping of central motor pathways and can affect normal developmental plasticity through altering neurotransmission, changes in cellular signalling, neural connectivity and function, wrong targeted innervation, and interruption of developmental apoptosis. Models of neonatal HI demonstrate three morphologically different types of cell death, that is, apoptosis, necrosis, and autophagy, which crosstalk and can exist as a continuum in the same cell. In the present review we discuss the mechanisms of HI injury to the immature brain and the way they affect plasticity.

Detection of viable cortical neurons using benzodiazepine receptor imaging after reversible focal ischaemia in rats: comparison with regional cerebral blood flow

International Nuclear Information System (INIS)

Watanabe, Yoshiyuki; Nakano, Takayuki; Yutani, Kenji; Nishimura, Hiroshi; Nishimura, Tsunehiko; Kusuoka, Hideo; Nakamura, Hironobu

2000-01-01

To elucidate the utility of benzodiazepine receptor imaging for the detection of viable cortical neurons, dual-tracer autoradiography using iodine-125 iomazenil (IMZ) and iodine-123 N-isopropyl-4-iodoamphetamine (IMP) was performed in a model of reversible focal ischaemia during the acute and subacute phases. The right middle cerebral artery of anaesthetized rats was occluded for 60 min using an intraluminal filament and reperfused. In the acute phase study, 125 I-IMZ (370 kBq) was injected via the femoral vein at 2 h after reperfusion, and 123 I-IMP (37 MBq) was injected at 50 min post-injection. Rats were sacrificed 10 min after the injection of 123 I-IMP. In the subacute phase study, the same procedure was performed at 5 days after reperfusion. In the acute phase, the IMP uptake was significantly decreased in almost all areas of the lesioned hemisphere, an exception being the cerebellum; however, the IMZ uptake was significantly decreased only in ischaemic cores. The discrepancy between IMZ and IMP uptake was observed in the lateral neocortex and the lateral caudate putamen (CPu), which were most frequently damaged in this ischaemic model. In the subacute phase, the IMZ uptake in lesioned rats was significantly decreased only in the parietal lobe and hippocampus, though the IMP uptake was decreased in many regions of lesioned hemispheres (the frontal, parietal cortex, CPu, hippocampus and thalamus). Histopathological findings indicated that both the IMP and the IMZ uptake was markedly decreased in necrotic areas. Although the IMP uptake was significantly decreased in the ischaemic areas, the IMZ uptake was maintained in these areas. These results suggest that benzodiazepine receptor imaging is superior to regional cerebral blood flow imaging for the detection of viable cortical neurons in both the acute and subacute phases of ischaemia. (orig.)

Detection of viable cortical neurons using benzodiazepine receptor imaging after reversible focal ischaemia in rats: comparison with regional cerebral blood flow

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yoshiyuki [Dept. of Radiology, Osaka National Hospital (Japan); Nakano, Takayuki; Yutani, Kenji; Nishimura, Hiroshi; Nishimura, Tsunehiko [Div. of Tracer Kinetics, Osaka University Medical School (Japan); Kusuoka, Hideo [Clinical Research Institute, Osaka National Hospital (Japan); Nakamura, Hironobu [Dept. of Radiology, Osaka University Medical School (Japan)

2000-03-01

To elucidate the utility of benzodiazepine receptor imaging for the detection of viable cortical neurons, dual-tracer autoradiography using iodine-125 iomazenil (IMZ) and iodine-123 N-isopropyl-4-iodoamphetamine (IMP) was performed in a model of reversible focal ischaemia during the acute and subacute phases. The right middle cerebral artery of anaesthetized rats was occluded for 60 min using an intraluminal filament and reperfused. In the acute phase study, {sup 125}I-IMZ (370 kBq) was injected via the femoral vein at 2 h after reperfusion, and {sup 123}I-IMP (37 MBq) was injected at 50 min post-injection. Rats were sacrificed 10 min after the injection of {sup 123}I-IMP. In the subacute phase study, the same procedure was performed at 5 days after reperfusion. In the acute phase, the IMP uptake was significantly decreased in almost all areas of the lesioned hemisphere, an exception being the cerebellum; however, the IMZ uptake was significantly decreased only in ischaemic cores. The discrepancy between IMZ and IMP uptake was observed in the lateral neocortex and the lateral caudate putamen (CPu), which were most frequently damaged in this ischaemic model. In the subacute phase, the IMZ uptake in lesioned rats was significantly decreased only in the parietal lobe and hippocampus, though the IMP uptake was decreased in many regions of lesioned hemispheres (the frontal, parietal cortex, CPu, hippocampus and thalamus). Histopathological findings indicated that both the IMP and the IMZ uptake was markedly decreased in necrotic areas. Although the IMP uptake was significantly decreased in the ischaemic areas, the IMZ uptake was maintained in these areas. These results suggest that benzodiazepine receptor imaging is superior to regional cerebral blood flow imaging for the detection of viable cortical neurons in both the acute and subacute phases of ischaemia. (orig.)

Ischaemic tolerance in aged mouse myocardium: the role of adenosine and effects of A1 adenosine receptor overexpression

Science.gov (United States)

Headrick, John P; Willems, Laura; Ashton, Kevin J; Holmgren, Kirsten; Peart, Jason; Matherne, G Paul

2003-01-01

The genesis of the ischaemia intolerant phenotype in aged myocardium is poorly understood. We tested the hypothesis that impaired adenosine-mediated protection contributes to ischaemic intolerance, and examined whether this is countered by A1 adenosine receptor (A1AR) overexpression. Responses to 20 min ischaemia and 45 min reperfusion were assessed in perfused hearts from young (2–4 months) and moderately aged (16–18 months) mice. Post-ischaemic contractility was impaired by ageing with elevated ventricular diastolic (32 ± 2 vs. 18 ± 2 mmHg in young) and reduced developed (37 ± 3 vs. 83 ± 6 mmHg in young) pressures. Lactate dehydrogenase (LDH) loss was exaggerated (27 ± 2 vs. 16 ± 2 IU g−1in young) whereas the incidence of tachyarrhythmias was similar in young (15 ± 1 %) and aged hearts (16 ± 1 %). Functional analysis confirmed equipotent effects of 50 μm adenosine at A1 and A2 receptors in young and aged hearts. Nonetheless, while 50 μm adenosine improved diastolic (5 ± 1 mmHg) and developed pressures (134 ± 7 mmHg) and LDH loss (6 ± 2 IU g−1) in young hearts, it did not alter these variables in the aged group. Adenosine did attenuate arrhythmogenesis for both ages (to ∼10 %). In contrast to adenosine, 50 μm diazoxide reduced ischaemic damage and arrhythmogenesis for both ages. Contractile and anti-necrotic effects of adenosine were limited by 100 μm 5-hydroxydecanoate (5-HD) and 3 μm chelerythrine. Anti-arrhythmic effects were limited by 5-HD but not chelerythrine. Non-selective (100 μm 8-sulfophenyltheophylline) and A1-selective (150 nm 8-cyclopentyl-1,3-dipropylxanthine) adenosine receptor antagonism impaired ischaemic tolerance in young but not aged hearts. Quantitative real-time PCR and radioligand analysis indicated that impaired protection is unrelated to changes in A1AR mRNA transcription, or receptor density (∼8 fmol mg−1 protein in both age groups). However, A1AR overexpression improved tolerance for both ages, restoring

An unusual presentation of ischaemic mitral regurgitation as P2 prolapse.

Science.gov (United States)

Thompson, David S; Punjabi, Prakash P

2017-11-01

A 54-year-old gentleman presented with pulmonary oedema secondary to anterolateral papillary muscle (PPM) rupture and acute mitral regurgitation subsequent to myocardial ischaemia (MI). Angiography revealed complete occlusion of the first obtuse marginal (OM1) branch of the circumflex coronary artery and a 70% occlusion of the left anterior descending (LAD) coronary artery. Operatively, unusual anatomy was noted; an accessory head was attached superiorly to the anterior lateral PPM. This gave rise to chordae that were subsequently attached to the posterior second (P2) scallop. Additionally, the P2 scallop was deficient in chordae from the posteromedial PPM, thus, loss of this accessory head led to severe mitral regurgitation. We review the PPM anatomy and pathological context of PPM rupture and ischaemic mitral regurgitation.

Retinoic acid-loaded polymeric nanoparticles enhance vascular regulation of neural stem cell survival and differentiation after ischaemia

Science.gov (United States)

Ferreira, R.; Fonseca, M. C.; Santos, T.; Sargento-Freitas, J.; Tjeng, R.; Paiva, F.; Castelo-Branco, M.; Ferreira, L. S.; Bernardino, L.

2016-04-01

Stroke is one of the leading causes of death and disability worldwide. However, current therapies only reach a small percentage of patients and may cause serious side effects. We propose the therapeutic use of retinoic acid-loaded nanoparticles (RA-NP) to safely and efficiently repair the ischaemic brain by creating a favourable pro-angiogenic environment that enhances neurogenesis and neuronal restitution. Our data showed that RA-NP enhanced endothelial cell proliferation and tubule network formation and protected against ischaemia-induced death. To evaluate the effect of RA-NP on vascular regulation of neural stem cell (NSC) survival and differentiation, endothelial cell-conditioned media (EC-CM) were collected. EC-CM from healthy RA-NP-treated cells reduced NSC death and promoted proliferation while EC-CM from ischaemic RA-NP-treated cells decreased cell death, increased proliferation and neuronal differentiation. In parallel, human endothelial progenitor cells (hEPC), which are part of the endogenous repair response to vascular injury, were collected from ischaemic stroke patients. hEPC treated with RA-NP had significantly higher proliferation, which further highlights the therapeutic potential of this formulation. To conclude, RA-NP protected endothelial cells from ischaemic death and stimulated the release of pro-survival, proliferation-stimulating factors and differentiation cues for NSC. RA-NP were shown to be up to 83-fold more efficient than free RA and to enhance hEPC proliferation. These data serve as a stepping stone to use RA-NP as vasculotrophic and neurogenic agents for vascular disorders and neurodegenerative diseases with compromised vasculature.

Revascularization experience and results in ischaemic cerebrovascular disease: Moyamoya disease and carotid occlusion.

Science.gov (United States)

Arikan, Fuat; Rubiera, Marta; Serena, Joaquín; Rodríguez-Hernández, Ana; Gándara, Darío; Lorenzo-Bosquet, Carles; Tomasello, Alejandro; Chocrón, Ivette; Quintana-Corvalan, Maximiliano; Sahuquillo, Juan

2018-03-14

Cerebral revascularization techniques are an indispensable tool in the current armamentarium of vascular neurosurgeons. We present revascularization surgery experience and results in both moyamoya disease and occlusive cerebral ischaemia. Patients with ischaemic occlusive disease and moyamoya disease who underwent microsurgical revascularization between October 2014 and September 2017 were analysed. In the study period, 23 patients with occlusive ischaemic disease underwent microsurgical revascularization. Three patients presented with serious postoperative complications (2 intraparenchymal haemorrhages in the immediate postoperative period and one thrombosis of the femoral artery). All patients, except one, achieved normalization of the cerebral hemodynamic reserve (CHR) in the SPECT study. Twenty patients had a good neurological result, with no ischaemic recurrence of the revascularized territory. Among patients with moyamoya, 20 had moyamoya disease and 5 had moyamoya syndrome with unilateral involvement. Five patients were treated at paediatric age. Haemorrhagic onset occurred in 2 patients. The CHR study showed hemodynamic compromise in all patients. Cerebral SPECT at one year showed resolution of the hemodynamic failure in all patients. There have been 4 postoperative complications (acute subdural hematoma, two subdural collections and one dehiscence of the surgical wound). No patient presented with neurological worsening at 6 and 12months of follow-up. Cerebral revascularization through end-to-side anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery is an indisputable technique in the treatment of moyamoya disease and possibly in a subgroup of patients with symptomatic occlusive ischaemic cerebrovascular disease. Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

Effect of ginseng pretreatment on cerebral glucose metabolism in ischaemic rats using animal positron emission tomography (PET) and [18F]-FDG

Energy Technology Data Exchange (ETDEWEB)

Rye, Choi Seok; Magata, Y.; Saji, H.; Tajima, K.; Kitano, H.; Konishi, J.; Yokoyama, A. [Department of Radiopharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-01 (Japan)

1997-07-01

To investigate the effect of ginseng on damaged brain activity, we evaluated the cerebral metabolic rate of glucose (CMRglc) as a functional index in post-ischaemic rats and compared the results with those obtained after the administration of a ginseng extract. CMRglc was measured using high resolution animal positron emission tomography with {sup 18}F-2-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG). The rats subjected to a 30-min occlusion showed a significant reduction of k3, the rate constant for phosphorylation of {sup 18}F-FDG by hexokinase, compared with the normal value. The ginseng pretreatment prevented the reduction in k3 and CMRglc caused by ischaemia. Although further investigation is needed to elucidate the mechanism of action, ginseng may be useful for prevention and treatment of ischaemia. © 1997 John Wiley & Sons, Ltd.

Silent ischaemia and hypertension

NARCIS (Netherlands)

Boon, D.; Piek, J. J.; van Montfrans, G. A.

2000-01-01

For many years now, silent ischaemia has been recognized as a distinct clinical entity, and its relevance in different patient groups has been established. However, a number of basic questions have not been answered. In explaining the pathophysiology of silent ischaemia, factors affecting both the

Protective Effect of Creatine Elevation against Ischaemia Reperfusion Injury Is Retained in the Presence of Co-Morbidities and during Cardioplegia.

Directory of Open Access Journals (Sweden)

Hannah J Whittington

Full Text Available Ischaemic heart disease is most prevalent in the ageing population and often exists with other comorbidities; however the majority of laboratory research uses young, healthy animal models. Several recent workshops and focus meetings have highlighted the importance of using clinically relevant models to help aid translation to realistic patient populations. We have previously shown that mice over-expressing the creatine transporter (CrT-OE have elevated intracellular creatine levels and are protected against ischaemia-reperfusion injury. Here we test whether elevating intracellular creatine levels retains a cardioprotective effect in the presence of common comorbidities and whether it is additive to protection afforded by hypothermic cardioplegia.CrT-OE mice and wild-type controls were subjected to transverse aortic constriction for two weeks to induce compensated left ventricular hypertrophy (LVH. Hearts were retrogradely perfused in Langendorff mode for 15 minutes, followed by 20 minutes ischaemia and 30 minutes reperfusion. CrT-OE hearts exhibited significantly improved functional recovery (Rate pressure product during reperfusion compared to WT littermates (76% of baseline vs. 59%, respectively, P = 0.02. Aged CrT-OE mouse hearts (78±5 weeks also had enhanced recovery following 15 minutes ischaemia (104% of baseline vs. 67%, P = 0.0007. The cardioprotective effect of hypothermic high K+ cardioplegic arrest, as used during cardiac surgery and donor heart transplant, was further enhanced in prolonged ischaemia (90 minutes in CrT-OE Langendorff perfused mouse hearts (76% of baseline vs. 55% of baseline as seen in WT hearts, P = 0.02.These observations in clinically relevant models further support the development of modulators of intracellular creatine content as a translatable strategy for cardiac protection against ischaemia-reperfusion injury.

Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

Energy Technology Data Exchange (ETDEWEB)

Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

1999-10-01

Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

International Nuclear Information System (INIS)

Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

1999-01-01

Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

The pleiotropic effects of simvastatin on retinal microvascular endothelium has important implications for ischaemic retinopathies.

Directory of Open Access Journals (Sweden)

Reinhold J Medina

Full Text Available BACKGROUND: Current guidelines encourage the use of statins to reduce the risk of cardiovascular disease in diabetic patients; however the impact of these drugs on diabetic retinopathy is not well defined. Moreover, pleiotropic effects of statins on the highly specialised retinal microvascular endothelium remain largely unknown. The objective of this study was to investigate the effects of clinically relevant concentrations of simvastatin on retinal endothelium in vitro and in vivo. METHODS AND FINDINGS: Retinal microvascular endothelial cells (RMECs were treated with 0.01-10 microM simvastatin and a biphasic dose-related response was observed. Low concentrations enhanced microvascular repair with 0.1 microM simvastatin significantly increasing proliferation (p<0.05, and 0.01 microM simvastatin significantly promoting migration (p<0.05, sprouting (p<0.001, and tubulogenesis (p<0.001. High concentration of simvastatin (10 microM had the opposite effect, significantly inhibiting proliferation (p<0.01, migration (p<0.01, sprouting (p<0.001, and tubulogenesis (p<0.05. Furthermore, simvastatin concentrations higher than 1 microM induced cell death. The mouse model of oxygen-induced retinopathy was used to investigate the possible effects of simvastatin treatment on ischaemic retinopathy. Low dose simvastatin (0.2 mg/Kg promoted retinal microvascular repair in response to ischaemia by promoting intra-retinal re-vascularisation (p<0.01. By contrast, high dose simvastatin(20 mg/Kg significantly prevented re-vascularisation (p<0.01 and concomitantly increased pathological neovascularisation (p<0.01. We also demonstrated that the pro-vascular repair mechanism of simvastatin involves VEGF stimulation, Akt phosphorylation, and nitric oxide production; and the anti-vascular repair mechanism is driven by marked intracellular cholesterol depletion and related disorganisation of key intracellular structures. CONCLUSIONS: A beneficial effect of low

Benfotiamine accelerates the healing of ischaemic diabetic limbs in mice through protein kinase B/Akt-mediated potentiation of angiogenesis and inhibition of apoptosis.

Science.gov (United States)

Gadau, S; Emanueli, C; Van Linthout, S; Graiani, G; Todaro, M; Meloni, M; Campesi, I; Invernici, G; Spillmann, F; Ward, K; Madeddu, P

2006-02-01

Benfotiamine, a vitamin B1 analogue, reportedly prevents diabetic microangiopathy. The aim of this study was to evaluate whether benfotiamine is of benefit in reparative neovascularisation using a type I diabetes model of hindlimb ischaemia. We also investigated the involvement of protein kinase B (PKB)/Akt in the therapeutic effects of benfotiamine. Streptozotocin-induced diabetic mice, given oral benfotiamine or vehicle, were subjected to unilateral limb ischaemia. Reparative neovascularisation was analysed by histology. The expression of Nos3 and Casp3 was evaluated by real-time PCR, and the activation state of PKB/Akt was assessed by western blot analysis and immunohistochemistry. The functional importance of PKB/Akt in benfotiamine-induced effects was investigated using a dominant-negative construct. Diabetic muscles showed reduced transketolase activity, which was corrected by benfotiamine. Importantly, benfotiamine prevented ischaemia-induced toe necrosis, improved hindlimb perfusion and oxygenation, and restored endothelium-dependent vasodilation. Histological studies revealed the improvement of reparative neovascularisation and the inhibition of endothelial and skeletal muscle cell apoptosis. In addition, benfotiamine prevented the vascular accumulation of advanced glycation end products and the induction of pro-apoptotic caspase-3, while restoring proper expression of Nos3 and Akt in ischaemic muscles. The benefits of benfotiamine were nullified by dominant-negative PKB/Akt. In vitro, benfotiamine stimulated the proliferation of human EPCs, while inhibiting apoptosis induced by high glucose. In diabetic mice, the number of circulating EPCs was reduced, with the deficit being corrected by benfotiamine. We have demonstrated, for the first time, that benfotiamine aids the post-ischaemic healing of diabetic animals via PKB/Akt-mediated potentiation of angiogenesis and inhibition of apoptosis. In addition, benfotiamine combats the diabetes-induced deficit in

New evidence of neuroprotection by lactate after transient focal cerebral ischaemia: extended benefit after intracerebroventricular injection and efficacy of intravenous administration.

Science.gov (United States)

Berthet, Carole; Castillo, Ximena; Magistretti, Pierre J; Hirt, Lorenz

2012-01-01

Lactate protects mice against the ischaemic damage resulting from transient middle cerebral artery occlusion (MCAO) when administered intracerebroventricularly at reperfusion, yielding smaller lesion sizes and a better neurological outcome 48 h after ischaemia. We have now tested whether the beneficial effect of lactate is long-lasting and if lactate can be administered intravenously. Male ICR-CD1 mice were subjected to 15-min suture MCAO under xylazine + ketamine anaesthesia. Na L-lactate (2 µl of 100 mmol/l) or vehicle was administered intracerebroventricularly at reperfusion. The neurological deficit was evaluated using a composite deficit score based on the neurological score, the rotarod test and the beam walking test. Mice were sacrificed at 14 days. In a second set of experiments, Na L-lactate (1 µmol/g body weight) was administered intravenously into the tail vein at reperfusion. The neurological deficit and the lesion volume were measured at 48 h. Intracerebroventricularly injected lactate induced sustained neuroprotection shown by smaller neurological deficits at 7 days (median = 0, min = 0, max = 3, n = 7 vs. median = 2, min = 1, max = 4.5, n = 5, p mouse brain against ischaemic damage when supplied intracerebroventricularly during reperfusion with behavioural and histological benefits persisting 2 weeks after ischaemia. Importantly, lactate also protects after systemic intravenous administration, a more suitable route of administration in a clinical emergency setting. These findings provide further steps to bring this physiological, commonly available and inexpensive neuroprotectant closer to clinical translation for stroke. Copyright © 2012 S. Karger AG, Basel.

[No role for oral anticoagulants (target INR: 2.0-3.0) after transient ischaemic attack or cerebral infarction of arterial origin; the 'European/Australasian stroke prevention in reversible ischaemia trial' (ESPRIT)].

Science.gov (United States)

De Schryver, E L L M; Halkes, P H A

2008-02-23

The 'European/Australasian stroke prevention in reversible ischaemia trial' (ESPRIT) aimed to determine whether oral anticoagulation of moderate intensity (target international normalised ratio (INR): 2.0-3.0) is more effective than acetylsalicylic acid in preventing future vascular events in patients with transient ischaemic attack (TIA) or minor stroke of arterial origin. International, multicentre randomised clinical trial. Patients were randomised within 6 months of TIA or minor stroke of arterial origin to oral anticoagulants (target INR: 2.0-3.0; n = 536) or acetylsalicylic acid (30-325 mg daily; n = 532). The primary endpoint was a composite of vascular death, non-fatal stroke, non-fatal myocardial infarction or major bleeding complications. In a post hoc analysis, the efficacy of anticoagulants was compared with that of the combination of acetylsalicylic acid and dipyridamole (200 mg twice daily), a third arm of ESPRIT. Treatment was unblinded, but auditing of endpoints was blinded. Data were analysed on an intent-to-treat basis. The comparison of anticoagulants and acetylsalicylic acid was stopped prematurely because the combination of acetylsalicylic acid and dipyridamole was found to be more effective than acetylsalicylic acid alone. The mean duration of follow-up was 4.6 years (SD: 2.2). The mean INR was 2.57 (SD: 0.86; nearly 70% of the time within target range). The primary endpoint occurred in 99 patients (19%) in the anticoagulation group and 98 patients (18%) in the acetylsalicylic acid group (hazard ratio: 1.02; 95% CI: 0.77-1.35). The hazard ratio was 0.73 (95% CI: 0.52-1.01) for ischaemic events and 2.56 (95% CI: 1.48-4.43) for major bleeding complications. The hazard ratio for the primary outcome event comparing anticoagulants with the combination of acetylsalicylic acid and dipyridamole was 1.31 (95% CI: 0.98-1.75). Oral anticoagulants (target INR: 2.0-3.0) were not more effective than acetylsalicylic acid in the secondary prevention of

Riboflavin (vitamin B-2) reduces hepatocellular injury following liver ischaemia and reperfusion in mice.

Science.gov (United States)

Sanches, Sheila Cristina; Ramalho, Leandra Naira Z; Mendes-Braz, Mariana; Terra, Vânia Aparecida; Cecchini, Rubens; Augusto, Marlei Josiele; Ramalho, Fernando Silva

2014-05-01

Riboflavin has been shown to exhibit anti-inflammatory and antioxidant properties in the settings of experimental sepsis and ischaemia/reperfusion (I/R) injury. We investigated the effect of riboflavin on normothermic liver I/R injury. Mice were submitted to 60 min of ischaemia plus saline or riboflavin treatment (30 μmoles/kg BW) followed by 6 h of reperfusion. Hepatocellular injury was evaluated by aminotransferase levels, reduced glutathione (GSH) content and the histological damage score. Hepatic neutrophil accumulation was assessed using the naphthol method and by measuring myeloperoxidase activity. Hepatic oxidative/nitrosative stress was estimated by immunohistochemistry. Liver endothelial and inducible nitric oxide synthase (eNOS/iNOS) and nitric oxide (NO) amounts were assessed by immunoblotting and a chemiluminescence assay. Riboflavin significantly reduced serum and histological parameters of hepatocellular damage, neutrophil infiltration and oxidative/nitrosative stress. Furthermore, riboflavin infusion partially recovered hepatic GSH reserves and decreased the liver contents of eNOS/iNOS and NO. These data indicate that riboflavin exerts antioxidant and anti-inflammatory effects in the ischaemic liver, protecting hepatocytes against I/R injury. The mechanism of these effects appears to be related to the intrinsic antioxidant potential of riboflavin/dihydroriboflavin and to reduced hepatic expression of eNOS/iNOS and reduced NO levels, culminating in attenuation of oxidative/nitrosative stress and the acute inflammatory response. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of Androgen Receptor in Vascular Cells on Reperfusion following Hindlimb Ischaemia.

Directory of Open Access Journals (Sweden)

Junxi Wu

Full Text Available Studies in global androgen receptor knockout (G-ARKO and orchidectomised mice suggest that androgen accelerates reperfusion of the ischaemic hindlimb by stimulating angiogenesis. This investigation used novel, vascular cell-specific ARKO mice to address the hypothesis that the impaired hindlimb reperfusion in G-ARKO mice was due to loss of AR from cells in the vascular wall.Mice with selective deletion of AR (ARKO from vascular smooth muscle cells (SM-ARKO, endothelial cells (VE-ARKO, or both (SM/VE-ARKO were compared with wild type (WT controls. Hindlimb ischaemia was induced in these mice by ligation and removal of the femoral artery. Post-operative reperfusion was reduced in SM-ARKO and SM/VE-ARKO mice. Immunohistochemistry indicated that this was accompanied by a reduced density of smooth muscle actin-positive vessels but no change in the density of isolectin B4-positive vessels in the gastrocnemius muscle. Deletion of AR from the endothelium (VE-ARKO did not alter post-operative reperfusion or vessel density. In an ex vivo (aortic ring culture model of angiogenesis, AR was not detected in vascular outgrowths and angiogenesis was not altered by vascular ARKO or by exposure to dihydrotestosterone (DHT 10-10-10-7M; 6 days.These results suggest that loss of AR from vascular smooth muscle, but not from the endothelium, contributes to impaired reperfusion in the ischaemic hindlimb of G-ARKO. Impaired reperfusion was associated with reduced collateral formation rather than reduced angiogenesis.

Mild episodes of tourniquet-induced forearm ischaemia-reperfusion injury results in leukocyte activation and changes in inflammatory and coagulation markers

Directory of Open Access Journals (Sweden)

Bastawrous Salah S

2007-05-01

significance (p = 0.014, although similar trends were observed with neutrophils these did not reach statistical significance. CRP was measured to assess the inflammatory response following mild episodes of ischaemia-reperfusion injury and resulted in a significant increase in the CRP concentration (p = Conclusion Tourniquet induced forearm ischaemia-reperfusion injury results in increased adhesiveness, trapping and activation of leukocytes. We report that, even following a mild ischaemic insult, this leukocyte response is immediately followed by evidence of increased inflammatory response, coagulation activity and endothelial damage. These results may have important implications and this pilot study may lead to a series of trials that shed light on the mechanisms of ischaemia-reperfusion injury, including potential points of therapeutic intervention for pathophysiological conditions.

Neuroprotective Mechanisms of Glucagon-like Peptide-1-based Therapies in Ischaemic Stroke

DEFF Research Database (Denmark)

Marlet, Ida R; Ölmestig, Joakim N E; Vilsbøll, Tina

2018-01-01

Review was to systematically evaluate the proposed mechanism of action for GLP-1-based therapies in ischaemic brain damage in animals. We performed a literature search using MEDLINE, EMBASE and The Cochrane Library. GLP-1-based therapies administered before, during or after experimental stroke in diabetic and non......Glucagon-like peptide-1 (GLP-1)-based therapies, GLP-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 inhibitors (DPP-4Is) are widely used for the treatment of type 2 diabetes. Increasing evidence suggests that they may provide neuroprotection. The aim of this Mini......-diabetic animals were evaluated. We reviewed 27 studies comprised of 20 involving GLP-1RAs and seven involving DPP-4Is. Both GLP-1RAs and DPP-4Is affected the acute inflammatory response secondary to ischaemia by reducing inflammation, endothelial leakage and excitotoxicity. Both treatments also reduced oxidative...

Neuroprotective effect of electroacupuncture and upregulation of hypoxia-inducible factor-1α during acute ischaemic stroke in rats.

Science.gov (United States)

Li, Ce; Zhang, Tingting; Yu, Kewei; Xie, Hongyu; Bai, Yulong; Zhang, Li; Wu, Yi; Wang, Nianhong

2017-10-01

Acupuncture is a traditional method that has been widely used in various fields of medicine with therapeutic effect. However, evidence of effectiveness to support the application of electroacupuncture (EA) during the process of ischaemia is scarce. To investigate dynamic changes in hypoxia-inducible factor (HIF)-1α expression as well as its association with neurological status in rats subjected to acute ischaemic stroke and EA intervention. Forty adult male rats were randomly divided into three groups that received sham surgery (Control group, n=10) or underwent middle cerebral artery occlusion and EA (MCAO+EA group, n=15) or minimal acupuncture as a control treatment (MCAO+MA group, n=15). The rats in the MCAO+EA and MCAO+MA groups received EA or acupuncture without any electrical current, respectively, during 90 min of ischaemia. Rats in the Control group received the same surgical procedure but without MCAO. EA involved electrical stimulation of needles inserted into the quadriceps at 50 Hz frequency and 3 mA current intensity. Neurological status was evaluated on postoperative day 1, and cerebral infarction volume (IV) and HIF-1α expression 24 hours later. Neurological scores were improved and cerebral IV was decreased in the MCAO+EA group compared to the MCAO+MA group (both p<0.05). Moreover, HIF-1α expression was higher in the MCAO+EA group versus the MCAO+MA group (p<0.05). EA enhanced recovery of neurological function, decreased cerebral IV and increased HIF-1α expression in ischaemic rats. Further research is needed to determine whether EA is effective for stroke treatment through the stimulation of muscle contraction. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Cortical spreading ischaemia is a novel process involved in ischaemic damage in patients with aneurysmal subarachnoid haemorrhage

DEFF Research Database (Denmark)

Dreier, Jens P; Major, Sebastian; Manning, Andrew

2009-01-01

flow and electrocorticography were simultaneously recorded in 417 CSDs. Isolated CSDs occurred in 12 patients and were associated with either physiological, absent or inverse haemodynamic responses. Whereas the physiological haemodynamic response caused tissue hyperoxia, the inverse response led......, causing either transient hyperperfusion (physiological haemodynamic response) in healthy tissue; or hypoperfusion [inverse haemodynamic response = cortical spreading ischaemia (CSI)] in tissue at risk for progressive damage, which has so far only been shown experimentally. Here, we performed a prospective......, multicentre study in 13 patients with aneurysmal subarachnoid haemorrhage, using novel subdural opto-electrode technology for simultaneous laser-Doppler flowmetry (LDF) and direct current-electrocorticography, combined with measurements of tissue partial pressure of oxygen (ptiO(2)). Regional cerebral blood...

Enhanced Vascular Endothelial Growth Factor Gene Expression in Ischaemic Skin of Critical Limb Ischaemia Patients

Directory of Open Access Journals (Sweden)

Silvia Bleda

2012-01-01

Full Text Available Objectives. To perform a quantitative analysis of the vascular endothelial growth factor (VEGF gene transcription in the skin of ischemic legs and provide information for VEGF in the pathogenesis in critical limb ischemia (CLI. Methods. Skin biopsies were obtained from 40 patients with CLI. Control samples came from 44 patients with chronic venous disease. VEGF gene expression was analysed using quantitative polymerase chain reaction. Results. Patients with CLI had higher skin VEGF expression than control group (RQ: 1.3 ± 0.1 versus 1, P=0.04. Conclusions. We found an association between ischemic skin and an elevated VEGF expression in legs from patients with CLI. These data support that the mechanism for VEGF upregulation in hypoxia conditions is intact and acts appropriately in the ischaemic limbs from patients with CLI.

Validation of housekeeping genes for quantitative real-time PCR in in-vivo and in-vitro models of cerebral ischaemia

Directory of Open Access Journals (Sweden)

Serena Joaquín

2009-06-01

Full Text Available Abstract Background Studies of gene expression in experimental cerebral ischaemia models can contribute to understanding the pathophysiology of brain ischaemia and to identifying prognostic markers and potential therapeutic targets. The normalization of relative qRT-PCR data using a suitable reference gene is a crucial prerequisite for obtaining reliable conclusions. No validated housekeeping genes have been reported for the relative quantification of the mRNA expression profile activated in in-vitro ischaemic conditions, whereas for the in-vivo model different reference genes have been used. The present study aims to determine the expression stability of ten housekeeping genes (Gapdh, β2m, Hprt, Ppia, Rpl13a, Oaz1, 18S rRNA, Gusb, Ywhaz and Sdha to establish their suitability as control genes for in-vitro and in-vivo cerebral ischaemia models. Results The expression stability of the candidate reference genes was evaluated using the 2-ΔC'T method and ANOVA followed by Dunnett's test. For the in-vitro model using primary cultures of rat astrocytes, all genes analysed except for Rpl13a and Sdha were found to have significantly different levels of mRNA expression. These different levels were also found in the case of the in-vivo model of pMCAO in rats except for Hprt, Sdha and Ywhaz mRNA, where the expression did not vary. Sdha and Ywhaz were identified by geNorm and NormFinder as the two most stable genes. Conclusion We have validated endogenous control genes for qRT-PCR analysis of gene expression in in-vitro and in-vivo cerebral ischaemia models. For normalization purposes, Rpl13a and Sdha are found to be the most suitable genes for the in-vitro model and Sdha and Ywhaz for the in-vivo model. Genes previously used as housekeeping genes for the in-vivo model in the literature were not validated as good control genes in the present study, showing the need for careful evaluation for each new experimental setup.

Isoprostanes--markers of ischaemia reperfusion injury.

LENUS (Irish Health Repository)

Sakamoto, H

2012-02-03

Ischaemia reperfusion injury is a common and important phenomenon that occurs predictably in patients undergoing such procedures as cardiopulmonary bypass, thrombolysis, surgery under tourniquet, organ transplantation or embolectomy. Oxidative stress and the resulting lipid peroxidation play a major role in reperfusion injury. Membrane and cellular dysfunction result and, subsequently, organ injury or failure may ensue. Traditional methods of quantifying ischaemia reperfusion injury, including measurement of malondialdehyde, lack specificity and sensitivity. It was reported in 1990 that isoprostanes, a series of prostaglandin-like compounds, are produced by the free radical-catalyzed peroxidation of arachidonic acid. Measurement of the isoprostane concentration in urine or plasma provides the most reliable, non-invasive method currently available to assess oxidative stress in vivo. Serial measurement of isoprostanes in biological fluids has enhanced our understanding of the mechanisms underlying ischaemia reperfusion injury itself and its role in certain diseases. Furthermore, measurement of the isoprostane concentration provides a means to assess the effects of prophylactic and therapeutic interventions. In the future, the development of rapid, simple assays for isoprostanes offers the potential to assess prognosis during and after ischaemia reperfusion events.

The pre-ischaemic neuroprotective effect of a novel polyamine antagonist, N1-dansyl-spermine in a permanent focal cerebral ischaemia model in mice.

Science.gov (United States)

Li, Jun; Henman, Martin C; Doyle, Karen M; Strbian, Daniel; Kirby, Brian P; Tatlisumak, Turgut; Shaw, Graham G

2004-12-10

The polyamine sites on the NMDA receptor complex offer a therapeutic target for focal ischaemia, potentially devoid of most side effects associated with NMDA antagonists. In this study, we investigated the effect of a novel polyamine antagonist, N(1)-dansyl-spermine (0.5-10 mg kg(-1)) in a permanent focal cerebral ischaemia model in mice, and compared its effect to that of MK-801 (0.3-3 mg kg(-1)) following administration 30 min prior to ischaemia. A battery of histological and behavioural tests was employed following permanent middle cerebral artery occlusion to assess any neuroprotective effect. Following middle cerebral artery occlusion, N(1)-dansyl-spermine (1-5 mg kg(-1)) and MK-801 (1 or 3 mg kg(-1)) caused a comparable and significant reduction in the percentage hemisphere lesion volume. Similarly, both drugs significantly reduced oedema and neurological deficit score to a similar extent. Locomotor activity in MCAO mice was not significantly improved by MK-801 or N(1)-dansyl-spermine, although N(1)-dansyl-spermine induced a trend towards significant improvement. Significant improvement in rotarod performance was observed at neuroprotective doses with both drugs. Upon comparison of the profile of effects, N(1)-dansyl-spermine at least matched the effectiveness of MK-801 as a neuroprotective agent in this model. In addition, in sham-operated control mice, N(1)-dansyl-spermine was well tolerated, in contrast to the pronounced adverse effects of MK-801 on locomotor activity and rotarod performance. In conclusion, this study has shown that N(1)-dansyl-spermine is as effective a neuroprotective drug as MK-801 in this model. Moreover, in contrast to MK-801, N(1)-dansyl-spermine could be a promising therapeutic candidate for stroke as it is well tolerated at neuroprotective doses in sham-operated animals.

Evaluation of technetium-99m exametazime stabilised with cobalt chloride as a blood flow tracer in focal cerebral ischaemia

Energy Technology Data Exchange (ETDEWEB)

Gartshore, G [Wellcome Surgical Inst. and Hugh Fraser Neuroscience Labs., Glasgow Univ. (United Kingdom); Bannan, P [Wellcome Surgical Inst. and Hugh Fraser Neuroscience Labs., Glasgow Univ. (United Kingdom); Patterson, J [Wellcome Surgical Inst. and Hugh Fraser Neuroscience Labs., Glasgow Univ. (United Kingdom); Higley, B [Wellcome Surgical Inst. and Hugh Fraser Neuroscience Labs., Glasgow Univ. (United Kingdom); McCulloch, J [Wellcome Surgical Inst. and Hugh Fraser Neuroscience Labs., Glasgow Univ. (United Kingdom)

1994-09-01

A protocol has been devised to effectively extend the limited post-reconstitution shelf life of technetium-99m exametazime as a radiopharmaceutical for imaging cerebral blood flow (CBF) distribution. The potential of [sup 99m]Tc-exametazime stabilised with cobalt chloride for imaging CBF distribution as late as 4 h after reconstitution has been examined in ischaemic and non-ischaemic tissue in halothane-anaesthetised cats. Focal cerebral ischaemia was produced by permanent middle cerebral artery occlusion. The relationship between [sup 99m]Tc-exametazime uptake and retention and CBF (assessed with [[sup 14]C]iodoantipyrine 10 min after first radiopharmaceutical administration) was determined in the same tissue section with double label autoradiography. Over the CBF range 0 - 80 ml 100 g[sup -1] min[sup -1], the uptake of [sup 99m]Tc-exametazime (quantitatively and topographically) was linearly related to CBF irrespective of whether the [sup 99m]Tc-labelled tracer was unstabilised (and administered within 10 min of reconstitution) or was stabilised with cobalt chloride (and administered up to 240 min after reconstitution). For levels of CBF in excess of 80 ml 100 g[sup -1] min[sup -1] the excellent topographical relationship between [sup 99m]Tc-exametazime distribution and CBF is maintained but quantitatively, [sup 99m]Tc-exametazime underestimates CBF to a similar degree in animals receiving stabilised and unstabilised [sup 99m]Tc-exametazime. The presence of the stabiliser, cobalt chloride, extends greatly the period over which [sup 99m]Tc-exametazime can be used after reconstitution to generate images of CBF distribution in normal and ischaemic cerebral tissue. (orig.)

The imaging of ischaemic stroke

International Nuclear Information System (INIS)

Hoggard, Nigel; Wilkinson, Iain D.; Griffiths, Paul D.

2001-01-01

Stroke is a clinical syndrome of a rapidly developing focal neurological deficit that may be classified for practical purposes into ischaemic and haemorrhagic. The role of imaging is to exclude mimics of ischaemic stroke or intracranial haemorrhage and confirm the presence of an ischaemic stroke. Computed tomography (CT) remains the investigation of choice to exclude acute intracranial haemorrhage but diffusion weighted magnetic resonance (MR) has proved to be a sensitive method of detecting early ischaemic infarction. Perfusion weighted MR allows further assessment at the same examination that could help guide the clinician in the risk/benefit analysis of treatment with thrombolytics or neuroprotective agents under evaluation. This can also be achieved with CT. This review article discusses the imaging of ischaemic stroke, relating the pathophysiology of stroke to it. It deals separately in more detail with these newer MR techniques. Hoggard, N. et al. (2001)

A stromal cell-derived factor-1 releasing matrix enhances the progenitor cell response and blood vessel growth in ischaemic skeletal muscle

Directory of Open Access Journals (Sweden)

D Kuraitis

2011-09-01

Full Text Available Although many regenerative cell therapies are being developed to replace or regenerate ischaemic muscle, the lack of vasculature and poor persistence of the therapeutic cells represent major limiting factors to successful tissue restoration. In response to ischaemia, stromal cell-derived factor-1 (SDF-1 is up-regulated by the affected tissue to stimulate stem cell-mediated regenerative responses. Therefore, we encapsulated SDF-1 into alginate microspheres and further incorporated these into an injectable collagen-based matrix in order to improve local delivery. Microsphere-matrix impregnation reduced the time for matrix thermogelation, and also increased the viscosity reached. This double-incorporation prolonged the release of SDF-1, which maintained adhesive and migratory bioactivity, attributed to chemotaxis in response to SDF-1. In vivo, treatment of ischaemic hindlimb muscle with microsphere-matrix led to increased mobilisation of bone marrow-derived progenitor cells, and also improved recruitment of angiogenic cells expressing the SDF-1 receptor (CXCR4 from bone marrow and local tissues. Both matrix and SDF-1-releasing matrix were successful at restoring perfusion, but SDF-1 treatment appeared to play an earlier role, as evidenced by arterioles that are phenotypically older and by increased angiogenic cytokine production, stimulating the generation of a qualitative microenvironment for a rapid and therefore more efficient regeneration. These results support the release of implanted SDF-1 as a promising method for enhancing progenitor cell responses and restoring perfusion to ischaemic tissues via neovascularisation.

Renal blood flow and metabolism after cold ischaemia

DEFF Research Database (Denmark)

Henriksen, J H; Petersen, H K

1984-01-01

Peroperative measurements of renal blood flow (RBF), renal O2-uptake, and renal venous lactate/pyruvate (L/P) ratio were performed before and after a period of 30-71 min of hypothermic (10-15 degrees C) renal ischaemia in nine patients, undergoing surgery for renal calculi. Before ischaemia, RBF.......01) immediately after re-established perfusion and 36% (P less than 0.02) 30 min later. In one additional patient, who had a short warm ischaemia (8 min), the flow pattern was the same. As arterial pressure remained constant, the reduced RBF signifies an increased renal vascular resistance. Renal O2-uptake...... and renal venous L/P ratio were almost constant, indicating no significant anaerobic processes being involved in the flow response. None of the patients showed any signs of reactive hyperaemia. It is concluded that hypothermic renal ischaemia may be followed by an increased renal vascular resistance even...

Over-expression of mitochondrial creatine kinase in the murine heart improves functional recovery and protects against injury following ischaemia-reperfusion.

Science.gov (United States)

Whittington, Hannah J; Ostrowski, Philip J; McAndrew, Debra J; Cao, Fang; Shaw, Andrew; Eykyn, Thomas R; Lake, Hannah; Tyler, Jack; Schneider, Jurgen E; Neubauer, Stefan; Zervou, Sevasti; Lygate, Craig A

2018-03-02

Mitochondrial creatine kinase (MtCK) couples ATP production via oxidative phosphorylation to phosphocreatine in the cytosol, which acts as a mobile energy store available for regeneration of ATP at times of high demand. We hypothesised that elevating MtCK would be beneficial in ischaemia-reperfusion (I/R) injury. Mice were created overexpressing the sarcomeric MtCK gene with αMHC promoter at the Rosa26 locus (MtCK-OE) and compared with wild-type (WT) littermates. MtCK activity was 27% higher than WT, with no change in other CK isoenzymes or creatine levels. Electron microscopy confirmed normal mitochondrial cell density and mitochondrial localisation of transgenic protein. Respiration in isolated mitochondria was unaltered and metabolomic analysis by 1H-NMR suggests that cellular metabolism was not grossly affected by transgene expression. There were no significant differences in cardiac structure or function under baseline conditions by cine-MRI or LV haemodynamics. In Langendorff-perfused hearts subjected to 20min ischaemia and 30 min reperfusion, MtCK-OE exhibited less ischaemic contracture and improved functional recovery (Rate pressure product 58% above WT; P < 0.001). These hearts had reduced myocardial infarct size, which was confirmed in vivo: 55±4% in WT vs 29±4% in MtCK-OE; P < 0.0001). Isolated cardiomyocytes from MtCK-OE hearts exhibited delayed opening of the mitochondrial permeability transition pore (mPTP) compared to WT, which was confirmed by reduced mitochondrial swelling in response to calcium. There was no detectable change in the structural integrity of the mitochondrial membrane. Modest elevation of MtCK activity in the heart does not adversely affect cellular metabolism, mitochondrial or in vivo cardiac function, but modifies mPTP opening to protect against I/R injury and improve functional recovery. Our findings support MtCK as a prime therapeutic target in myocardial ischaemia.

Intestinal Ischaemia Associated with Carcinoid Tumor: A Case Report with Review of the Pathogenesis

Directory of Open Access Journals (Sweden)

Oktay Yener

2013-01-01

Full Text Available Carcinoid tumors are rare, slow-growing neuroendocrine neoplasms that are often indolent and may not become clinically apparent until there is a metastatic spread or evidence of carcinoid syndrome.  A 44-year-old man presented to our clinic department with a history of previous left colon cancer operation, chronic crampy left lower quadrant pain, mass and severe anemia.  A MR scan was obtained which demonstrated a calcified mesenteric mass 12×8×10 cm diameter with surrounding left colon mesenteric infiltration. The liver was normal. A case of ischaemic ileal necrosis is reported. It was associated with elastic vascular sclerosis produced by mesenteric metastases of an ileal carcinoid tumor. It is postulated that intestinal ischaemia may be of more importance in the production of abdominal pain by carcinoid tumors than has been generally accepted, and that it is the result of functional and structural changes in and around the mesenteric blood vessels, caused by substances secreted by the carcinoid tumor.

Ischaemic heart disease

International Nuclear Information System (INIS)

Ruttley, M.

1985-01-01

Radiology has an important role in the diagnosis and management of ischaemic heart disease, notably in the investigation of angina pectoris, the monitoring of acute myocardial infarction and the assessment of its non-fatal complications; recent application of catheter techniques to the treatment of ischaemic heart disease has been a progression from Dotter's original work on peripheral arterial dilation made possible by Gruntzig's development of a suitable dilating catheter for coronary stenosis

Differences in autonomic nerve function in patients with silent and symptomatic myocardial ischaemia.

Science.gov (United States)

Shakespeare, C. F.; Katritsis, D.; Crowther, A.; Cooper, I. C.; Coltart, J. D.; Webb-Peploe, M. W.

1994-01-01

BACKGROUND--Autonomic neuropathy provides a mechanism for the absence of symptoms in silent myocardial ischaemia, but characterisation of the type of neuropathy is lacking. AIM--To characterise and compare autonomic nerve function in patients with silent and symptomatic myocardial ischaemia. METHODS AND RESULTS--The Valsalva manoeuvre, heart rate variation (HRV) in response to deep breathing and standing, lower body negative pressure, isometric handgrip, and the cold pressor test were performed by patients with silent (n = 25) and symptomatic (n = 25) ambulatory ischaemia and by controls (n = 21). No difference in parasympathetic efferent function between patients with silent and symptomatic ischaemia was recorded, but both had significantly less HRV in response to standing than the controls (p < 0.005 for silent and p < 0.01 for symptomatic). Patients with silent ischaemia showed an increased propensity for peripheral vasodilatation compared with symptomatic patients (p < 0.02) and controls (p < 0.04). Impaired sympathetic function was found in patients with pure silent ischaemia (n = 4) compared with the remaining patients with silent ischaemia whose pain pathways were presumed to be intact. CONCLUSIONS--Patients with silent ischaemia and pain pathways presumed to be intact have an enhanced peripheral vasodilator response, and if this applied to the coronary vasculature it could provide a mechanism for limiting ischaemia to below the pain threshold. Patients with pure silent ischaemia have evidence of sympathetic autonomic dysfunction. Images PMID:8297687

In vivo effect of the D-(-) isomer or natural form of 3-hydroxybutyrate on initial release of lactate dehydrogenase from the acutely ischaemic myocardium.

Science.gov (United States)

Lammerant, J; Huynh-Thu, T; Kolanowski, J

1986-07-01

D-(-)-3-hydroxybutyrate, the isomer found in the circulation and in the urine of diabetic patients, generally is believed to be the physiologically important form of 3-hydroxybutyrate [10]. Little is known concerning the effects of an elevated plasma level of the D-(-) isomer of 3-hydroxybutyrate upon the acutely ischaemic heart. Using anaesthetized intact dogs with a balloon catheter inserted into the proximal part of the left anterior descending coronary artery (LAD), we have recently demonstrated that a 1 mM ketonaemia induced with the arginine salt of D-(-)-3-hydroxybutyric acid reduces the uptake of non-esterified fatty acids (NEFA) in the myocardial area distal to the inflated balloon [4]. The question arises as to whether the concomitant increase in ketone uptake in this area could be detrimental to the acutely ischaemic myocardium. Indeed, a previous study on isolated coronary ligated hearts from normal rats has shown that the rate of release of lactate dehydrogenase (LDH) during the first 90 min of ischaemia can be enhanced by replacing glucose (11 mM) in the perfusion fluid with either albumin-bound palmitate (0.9 mM) or sodium DL-3-hydroxybutyrate (10 mM) as the sole energy substrate [11]. This would suggest that the ketone might be as deleterious as its metabolic precursors for membrane integrity in the acutely ischaemic myocardium. In the present report, we examine the effect of arginine D-(-)-3-hydroxybutyrate on LDH release from ischaemic myocardium in our in vivo preparation. The dogs were treated with lidocaine in order to minimize the frequency and, hence, the adverse metabolic effects of ectopic beats.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioiodinated diacylglycerol analogue: a potential imaging agent for single-photon emission tomographic investigations of cerebral ischaemia

Energy Technology Data Exchange (ETDEWEB)

Ohmori, Y. [Department of Neurosurgery, Kyoto Prefectural University of Medicine, Kyoto (Japan); Imahori, Y. [Department of Neurosurgery, Kyoto Prefectural University of Medicine, Kyoto (Japan); Ueda, S. [Department of Neurosurgery, Kyoto Prefectural University of Medicine, Kyoto (Japan); Fujii, R. [Nishijin Hospital, Kyoto (Japan); Wakita, K. [Nishijin Hospital, Kyoto (Japan); Inoue, M. [Daiichi Radioisotope Laboratories, Chiba (Japan); Tazawa, S. [Daiichi Radioisotope Laboratories, Chiba (Japan)

1996-03-01

Phospholipid metabolism is closely related to membrane perturbation in cerebral ischaemia. We investigated in vivo topographical lipid metabolism using an iodine-123-labelled diacylglycerol analogue, (1-(15-(4-iodine-123-iodophenyl)-pentadecanoyl)-2-stearoyl-rac-glycerol) ({sup 123}I-labelled DAG), in a middle cerebral artery (MCA) occlusion model with the aim of positive imaging of ischaemic insult. Sprague-Dawley rats underwent coagulation of the MCA to induce permanent occlusion. MCA occlusion times prior to injection of {sup 123}I-labelled DAG ranged from 15 min to 14 days. Each rat was injected with 11-37 MBq of {sup 123}I-labelled DAG. After 30 min, in vivo autoradiographs were reconstructed. Scanning of the living rat brain in this MCA occlusion model was performed. Cerebral infarctions were recognized in the frontal cortex, the parietal cortex and the lateral portion of the caudate-putamen by 2, 3, 5-triphenyltetrazolium hydrochloride staining. In infarcted regions (region 1), {sup 123}I-labelled DAG incorporation showed a decrease up to 12 h; it then increased up to 6 days and decreased thereafter. In peri-infarcted regions (region 2), the incorporation showed almost no change up to 12 h, then increased up to 5-6 days and decreased thereafter. In other regions (region 3), the incorporation showed no change. Lipid analysis showed that {sup 123}I-labelled DAG was metabolized to 15-(4-iodine-123-iodophenyl)-pentadecanoic acid by DAG lipase and to {sup 123}I-labelled phosphatidylcholine. Scanning of the ischaemic region showed higher accumulation than on the non-lesioned side. We established a method to visualize ischaemic foci as positive images. The early changes in {sup 123}I-labelled DAG incorporation were related to DAG lipase, which degraded the accumulated intrinsic DAG, and increased {sup 123}I-labelled DAG incorporation in the chronic stage involves several aspects of neural destruction in the process of autolysis.

Radioiodinated diacylglycerol analogue: a potential imaging agent for single-photon emission tomographic investigations of cerebral ischaemia

International Nuclear Information System (INIS)

Ohmori, Y.; Imahori, Y.; Ueda, S.; Fujii, R.; Wakita, K.; Inoue, M.; Tazawa, S.

1996-01-01

Phospholipid metabolism is closely related to membrane perturbation in cerebral ischaemia. We investigated in vivo topographical lipid metabolism using an iodine-123-labelled diacylglycerol analogue, (1-(15-(4-iodine-123-iodophenyl)-pentadecanoyl)-2-stearoyl-rac-glycerol) ( 123 I-labelled DAG), in a middle cerebral artery (MCA) occlusion model with the aim of positive imaging of ischaemic insult. Sprague-Dawley rats underwent coagulation of the MCA to induce permanent occlusion. MCA occlusion times prior to injection of 123 I-labelled DAG ranged from 15 min to 14 days. Each rat was injected with 11-37 MBq of 123 I-labelled DAG via a tail vein. After 30 min, in vivo autoradiographs were reconstructed. Scanning of the living rat brain in this MCA occlusion model was performed using a gamma camera with a pinhole collimator. Cerebral infarctions were recognized in the frontal cortex, the parietal cortex and the lateral portion of the caudate-putamen by 2, 3, 5-triphenyltetrazolium hydrochloride staining. In infarcted regions (region 1), 123 I-labelled DAG incorporation showed a slight decrease up to 12 h; it then increased up to 6 days and decreased thereafter. In peri-infarcted regions (region 2), the incorporation showed almost no change up to 12 h, then increased up to 5-6 days and decreased thereafter. In other regions (region 3), the incorporation showed no change. Lipid analysis showed that 123 I-labelled DAG was metabolized to 15-(4-iodine-123-iodophenyl)-pentadecanoic acid by DAG lipase and to 123 I-labelled phosphatidylcholine. Scanning of the ischaemic region showed higher accumulation than on the non-lesioned side. We established a method to visualize ischaemic foci as positive images. The early changes in 123 I-labelled DAG incorporation were closely related to DAG lipase, which degraded the accumulated intrinsic DAG, and increased 123 I-labelled DAG incorporation in the chronic stage involves several aspects of neural destruction in the process of

Liposome-based vascular endothelial growth factor-165 transfection with skeletal myoblast for treatment of ischaemic limb disease.

Science.gov (United States)

Ye, Lei; Haider, Husnain Kh; Esa, Wahidah Bte; Su, Liping; Law, Peter K; Zhang, Wei; Lim, Yeanteng; Poh, Kian Keong; Sim, Eugene K W

2010-01-01

The study aims to use cholesterol (Chol) + DOTAP liposome (CD liposome) based human vascular endothelial growth factor-165 (VEGF(165)) gene transfer into skeletal myoblasts (SkMs) for treatment of acute hind limb ischaemia in a rabbit model. The feasibility and efficacy of CD liposome mediated gene transfer with rabbit SkMs were characterized using plasmid carrying enhanced green fluorescent protein (pEGFP) and assessed by flow cytometry. After optimization, SkMs were transfected with CD lipoplexes carrying plasmid-VEGF(165) (CD-pVEGF(165)) and transplanted into rabbit ischaemic limb. Animals were randomized to receive intramuscular injection of Medium199 (M199; group 1), non-transfected SkM (group 2) or CD-pVEGF(165) transfected SkM (group 3). Flow cytometry revealed that up to 16% rabbit SkMs were successfully transfected with pEGFP. Based on the optimized transfection condition, transfected rabbit SkM expressed VEGF(165) up to day 18 with peak at day 2. SkMs were observed in all cell-transplanted groups, as visualized with 6-diamidino-2-phenylindole and bromodeoxyuridine. Angiographic blood vessel score revealed increased collateral vessel development in group 3 (39.7 +/- 2.0) compared with group 2 (21.6 +/- 1.1%, P limb and may serve as a safe and new therapeutic modality for the repair of acute ischaemic limb disease.

Monitoring of glycolytic activity secondary to ischaemia in knee replacement surgery.

Science.gov (United States)

León-Muñoz, V J; Lisón-Almagro, A J; Hernández-García, C H; López-López, M

2018-04-17

To non-invasively assess tissue lesion secondary to ischaemia applied during knee replacement surgery. Secondary objectives: to assess whether this lesion correlates with the duration of ischaemia and whether instrumental and gender variables influence it. Prospective cohort study. Pre and postoperative serum lactate levels have been determined as an indicator of glycolytic activity secondary to ischaemia in 88 patients. Serum lactate determination was performed by reactive strips of enzymatic-amperometric detection on capillary blood. Preoperative serum lactate levels (mean and SD): 2.467±1.036 mmol/L. Postoperative serum lactate levels: 3.938±2.018 mmol/L. Ischaemia time 102.98±18.25minutes. Postoperative serum lactate levels were significantly higher than preoperative lactate levels. There are no statistical differences according to the time that the ischaemia was prolonged, gender or type of instrumentation used. In our study, postoperative serum lactate values were significantly higher than preoperative lactate values, with no correlation to the duration of ischaemia during knee replacement surgery. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

The Difficult Diagnosis of Ischaemic Papillary Muscle Rupture; Case report from an urban emergency department

Directory of Open Access Journals (Sweden)

Christian T. Braun

2016-05-01

Full Text Available We present a rare case of severe ischaemic papillary muscle rupture in a 67-year-old male patient who was admitted to the Emergency Department of the University Hospital Bern, Switzerland, in November 2013 with acute chest pain. On admission, the patient’s blood pressure was 60/40 mm/Hg, his pulse was 110 beats per minute and his respiratory rate was 20 breaths per minute. An electrocardiogram was normal and focused assessment with sonography in trauma was negative. Transthoracic echocardiography showed possible thickening of the mitral valve leaflet with no indications of severe mitral insufficiency or wall motion abnormalities. Triple-ruleout computed tomography angiography revealed no pulmonary emboli or aortic dissection, although coronary atherosclerosis was present. Finally, severe insufficiency of the mitral valve with rupture of the papillary muscle, likely due to ischaemia, was observed via transoesophageal echocardiography. The patient underwent a successful surgical intervention and was discharged 10 days later in stable condition.

Spontaneous ischaemic stroke lesions in a dog brain

DEFF Research Database (Denmark)

Thomsen, Barbara Blicher; Gredal, Hanne; Nielsen, Martin Wirenfeldt

2017-01-01

Background Dogs develop spontaneous ischaemic stroke with a clinical picture closely resembling human ischaemic stroke patients. Animal stroke models have been developed, but it has proved difficult to translate results obtained from such models into successful therapeutic strategies in human...... stroke patients. In order to face this apparent translational gap within stroke research, dogs with ischaemic stroke constitute an opportunity to study the neuropathology of ischaemic stroke in an animal species. Case presentation A 7 years and 8 months old female neutered Rottweiler dog suffered....../macrophages and astrocytes. Conclusions The neuropathological changes reported in the present study were similar to findings in human patients with ischaemic stroke. The dog with spontaneous ischaemic stroke is of interest as a complementary spontaneous animal model for further neuropathological studies....

Changes in intestinal electrical activity during ischaemia correlate to ...

African Journals Online (AJOL)

To study this, the electrical activity of the ileum in 14 adult male rabbits was recorded during ischaemia. At baseline, 60, 120 and 210 minutes of ischaemia, segments of bowel were resected for histopathologic evaluation. The BER frequency was determined using the Fast Fourier Transformation (FFT) spectral analysis.

Pre-ischemic mitochondrial substrate constraint by inhibition of malate-aspartate shuttle preserves mitochondrial function after ischemia-reperfusion

DEFF Research Database (Denmark)

Jespersen, Nichlas Riise; Yokota, Takashi; Støttrup, Nicolaj Brejnholt

2017-01-01

KEY POINTS: Pre-ischaemic administration of aminooxiacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against ischaemia-reperfusion injury. The underlying mechanism remains unknown. We examined whether transient inhibition of the MAS during ischaemia......, but not IPC, reduced the myocardial interstitial concentration of tricarboxylic acid cycle intermediates at the onset of reperfusion. The results obtained in the present study demonstrate that metabolic regulation by inhibition of the MAS at the onset of reperfusion may be beneficial for the preservation...... of mitochondrial function during late reperfusion in an IR-injured heart. ABSTRACT: Mitochondrial dysfunction plays a central role in ischaemia-reperfusion (IR) injury. Pre-ischaemic administration of aminooxyacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against IR...

Protective effects of repetitive transcranial magnetic stimulation in a rat model of transient cerebral ischaemia: a microPET study

International Nuclear Information System (INIS)

Gao, Feng; Wang, Shuang; Guo, Yi; Lou, Min; Wu, Jimin; Ding, Meiping; Wang, Jing; Zhang, Hong; Tian, Mei

2010-01-01

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method to excite neurons in the brain. However, the underlying mechanism of its therapeutic effects in stroke remains unclear. The aim of this study was to investigate the neuroprotective effect of high-frequency rTMS in a rat model of transient cerebral ischaemia using positron emission tomography (PET). Sprague-Dawley rats (n=30) were anaesthetized with chloral hydrate and subjected to 90 min of intraluminal middle cerebral artery occlusion (MCAO) with subsequent reperfusion in three groups: control (n=10), rTMS (n=10), or sham-rTMS groups (n=10). In the rTMS group, rTMS was given 1 h after ischaemia and every 24 h for 7 days after MCAO. In all three groups, small-animal PET (microPET) imaging with 18 F-FDG was used to evaluate brain glucose metabolism. Apoptotic molecules were measured in the infarct margin using immunohistochemical staining. The neurological scores of the rats in the rTMS group were higher than in those of the control group over the whole 7-day observation period. The total, cortical and striatal infarct volumes were significantly less in the rTMS group than in the control group, as measured by 2,3,5-triphenyltetrazolium chloride staining. 18 F-FDG microPET images showed significantly higher standardized uptake values in the cortex and striatum in the rTMS group than in the control group in the affected hemisphere. The number of cells positive for caspase-3 was significantly lower in the rTMS group than in the control group, while the Bcl-2/Bax ratio was significantly higher in the rTMS group than in the control group. rTMS therapy increased glucose metabolism and inhibited apoptosis in the ischaemic hemisphere. 18 F-FDG PET could be used to monitor rTMS therapy in transient cerebral ischaemia in animal studies and in future clinical trials. (orig.)

Protective effects of repetitive transcranial magnetic stimulation in a rat model of transient cerebral ischaemia: a microPET study

Energy Technology Data Exchange (ETDEWEB)

Gao, Feng [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Neurology, Hangzhou, Zhejiang (China); Zhejiang University Medical PET Center, Hangzhou, Zhejiang (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, Zhejiang (China); Wang, Shuang; Guo, Yi; Lou, Min; Wu, Jimin; Ding, Meiping [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Neurology, Hangzhou, Zhejiang (China); Wang, Jing; Zhang, Hong [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Zhejiang University Medical PET Center, Hangzhou, Zhejiang (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, Zhejiang (China); Tian, Mei [The University of Texas M.D. Anderson Cancer Center, Department of Experimental Diagnostic Imaging, Houston, TX (United States)

2010-05-15

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method to excite neurons in the brain. However, the underlying mechanism of its therapeutic effects in stroke remains unclear. The aim of this study was to investigate the neuroprotective effect of high-frequency rTMS in a rat model of transient cerebral ischaemia using positron emission tomography (PET). Sprague-Dawley rats (n=30) were anaesthetized with chloral hydrate and subjected to 90 min of intraluminal middle cerebral artery occlusion (MCAO) with subsequent reperfusion in three groups: control (n=10), rTMS (n=10), or sham-rTMS groups (n=10). In the rTMS group, rTMS was given 1 h after ischaemia and every 24 h for 7 days after MCAO. In all three groups, small-animal PET (microPET) imaging with {sup 18}F-FDG was used to evaluate brain glucose metabolism. Apoptotic molecules were measured in the infarct margin using immunohistochemical staining. The neurological scores of the rats in the rTMS group were higher than in those of the control group over the whole 7-day observation period. The total, cortical and striatal infarct volumes were significantly less in the rTMS group than in the control group, as measured by 2,3,5-triphenyltetrazolium chloride staining. {sup 18}F-FDG microPET images showed significantly higher standardized uptake values in the cortex and striatum in the rTMS group than in the control group in the affected hemisphere. The number of cells positive for caspase-3 was significantly lower in the rTMS group than in the control group, while the Bcl-2/Bax ratio was significantly higher in the rTMS group than in the control group. rTMS therapy increased glucose metabolism and inhibited apoptosis in the ischaemic hemisphere. {sup 18}F-FDG PET could be used to monitor rTMS therapy in transient cerebral ischaemia in animal studies and in future clinical trials. (orig.)

Post-infarctus, ischémie myocardique: importance clinique et facteur de risque

DEFF Research Database (Denmark)

Jespersen, C

1995-01-01

disease surviving out of hospital cardiac arrest - improves the prognosis, indicates that transient ischaemic attacks might be the trigger of malignant ventricular arrhythmias in patients with prior myocardial infarction. Patients with large infarct scars (heart failure) have an increased incidence...... and the release of abnormal automatic responses of the partially repolarised cells. The mechanism(s) by which complex ventricular arrhythmias is/are transformed into malignant arrhythmias has/have not yet been definitely proven. The observation that coronary revascularization - in patients with ischaemic heart......, indicating that residual ischaemia might be the major risk variable in patients with heart failure. Ischaemia is one of several risk markers for transient supraventricular arrhythmias in patients recovering from an acute myocardial infarction (AMI). In addition, anti-ischaemic intervention in patients...

Cardioprotective effect of L-glutamate in obese type 2 diabetic Zucker fatty rats

DEFF Research Database (Denmark)

Povlsen, Jonas Agerlund; Løfgren, Bo; Rasmussen, Lars Ege

2009-01-01

(Wistar-Kyoto) and diabetic (Zucker diabetic fatty (ZDF)) rats, studied at 16 weeks of age. The infarct size (IS)/area-at-risk (AAR) ratio was the primary end-point. Expression of L-glutamate excitatory amino acid transporter (EAAT) 1 (mitochondrial) and EAAT3 (sarcolemmal) was determined by quantitative......1. Because diabetic hearts have an increased threshold for cardioprotection by ischaemic preconditioning (IPC), we hypothesized that protection by L-glutamate during reperfusion is restricted in Type 2 diabetic hearts. Previously, we found that L-glutamate-mediated postischaemic cardioprotection...... mimics IPC. 2. Rat hearts were studied in a Langendorff preparation perfused with Krebs'-Henseleit solution and subjected to 40 min global no-flow ischaemia, followed by 120 min reperfusion. L-Glutamate (0, 15 and 30 mmol/L) was added to the perfusate during reperfusion of hearts from non-diabetic...

Spontaneous ischaemic stroke lesions in a dog brain: neuropathological characterisation and comparison to human ischaemic stroke

DEFF Research Database (Denmark)

Thomsen, Barbara Blicher; Gredal, Hanne; Wirenfeldt, Martin

2017-01-01

Background Dogs develop spontaneous ischaemic stroke with a clinical picture closely resembling human ischaemic stroke patients. Animal stroke models have been developed, but it has proved difficult to translate results obtained from such models into successful therapeutic strategies in human str...

Evolving changes in fetal heart rate variability and brain injury after hypoxia-ischaemia in preterm fetal sheep.

Science.gov (United States)

Yamaguchi, Kyohei; Lear, Christopher A; Beacom, Michael J; Ikeda, Tomoaki; Gunn, Alistair J; Bennet, Laura

2018-01-08

Fetal heart rate variability is a critical index of fetal wellbeing. Suppression of heart rate variability may provide prognostic information on the risk of hypoxic-ischaemic brain injury after birth. In the present study, we report the evolution of fetal heart rate variability after both mild and severe hypoxia-ischaemia. Both mild and severe hypoxia-ischaemia were associated with an initial, brief suppression of multiple measures of heart rate variability. This was followed by normal or increased levels of heart rate variability during the latent phase of injury. Severe hypoxia-ischaemia was subsequently associated with the prolonged suppression of measures of heart rate variability during the secondary phase of injury, which is the period of time when brain injury is no longer treatable. These findings suggest that a biphasic pattern of heart rate variability may be an early marker of brain injury when treatment or intervention is probably most effective. Hypoxia-ischaemia (HI) is a major contributor to preterm brain injury, although there are currently no reliable biomarkers for identifying infants who are at risk. We tested the hypothesis that fetal heart rate (FHR) and FHR variability (FHRV) would identify evolving brain injury after HI. Fetal sheep at 0.7 of gestation were subjected to either 15 (n = 10) or 25 min (n = 17) of complete umbilical cord occlusion or sham occlusion (n = 12). FHR and four measures of FHRV [short-term variation, long-term variation, standard deviation of normal to normal R-R intervals (SDNN), root mean square of successive differences) were assessed until 72 h after HI. All measures of FHRV were suppressed for the first 3-4 h in the 15 min group and 1-2 h in the 25 min group. Measures of FHRV recovered to control levels by 4 h in the 15 min group, whereas the 25 min group showed tachycardia and an increase in short-term variation and SDNN from 4 to 6 h after occlusion. The measures of FHRV then progressively

99Tcm-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease

International Nuclear Information System (INIS)

Sciammarella, M.G.; Fragasso, G.; Gerundini, P.; Maffioli, L.; Cappelletti, A.; Margonato, A.; Savi, A.; Chierchia, S.

1992-01-01

The ability of 99 Tc m -methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients with clinically recognised ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise 90 min after injection of 99 Tc m -MIBI. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities. In conclusion, MIBI SPET is a highly reliable technique for assessing the presence and location of myocardial ischaemia and necrosis. (Author)

Role of gap junctional coupling in astrocytic networks in the determination of global ischaemia-induced oxidative stress and hippocampal damage.

Science.gov (United States)

Perez Velazquez, Jose L; Kokarovtseva, Larisa; Sarbaziha, Raheleh; Jeyapalan, Zina; Leshchenko, Yevgen

2006-01-01

While there is evidence that gap junctions play important roles in the determination of cell injuries, there is not much known about mechanisms by which gap junctional communication may exert these functions. Using a global model of transient ischaemia in rats, we found that pretreatment with the gap junctional blockers carbenoxolone, 18alpha-glycyrrhetinic acid and endothelin, applied via cannulae implanted into the hippocampus in one hemisphere, resulted in decreased numbers of TUNEL-positive neurons, as compared with the contralateral hippocampus that received saline injection. Post-treatment with carbenoxolone for up to 30 min after the stroke injury still resulted in decreased cell death, but post-treatment at 90 min after the ischaemic insult did not result in differences in cell death. However, quinine, an inhibitor of Cx36-mediated gap junctional coupling, did not result in appreciable neuroprotection. Searching for a possible mechanism for the observed protective effects, possible actions of the gap junctional blockers in the electrical activity of the hippocampus during the ischaemic insult were assessed using intracerebral recordings, with no differences observed between the saline-injected and the contralateral drug-injected hippocampus. However, a significant reduction in lipid peroxides, a measure of free radical formation, in the hippocampus treated with carbenoxolone, revealed that the actions of gap junctional coupling during injuries may be causally related to oxidative stress. These observations suggest that coupling in glial networks may be functionally important in determining neuronal vulnerability to oxidative injuries.

Calcinosis is associated with digital ischaemia in systemic sclerosis—a longitudinal study

Science.gov (United States)

Pope, Janet; Robinson, David; Jones, Niall; Khalidi, Nader; Docherty, Peter; Kaminska, Elzbieta; Masetto, Ariel; Sutton, Evelyn; Mathieu, Jean-Pierre; Ligier, Sophie; Grodzicky, Tamara; LeClercq, Sharon; Thorne, Carter; Gyger, Geneviève; Smith, Douglas; Fortin, Paul R.; Larché, Maggie; Abu-Hakima, Maysan; Rodriguez-Reyna, Tatiana S.; Cabral-Castaneda, Antonio R.; Fritzler, Marvin J.; Wang, Mianbo; Hudson, Marie

2016-01-01

Objective. To determine if ischaemia is a causal factor in the development of calcinosis in SSc. Methods. Patients with SSc were assessed yearly. Physicians reported the presence of calcinosis, digital ischaemia (digital ulcers, digital necrosis/gangrene, loss of digital pulp on any digits and/or auto- or surgical digital amputation) and nailfold capillary dropout assessed using a dermatoscope. The number of digits with digital ischaemia was used as an assessment of the severity of digital ischaemia. SSc specific antibodies were detected with a line immunoassay. Multiple logistic regression and Cox proportional hazards models were generated to determine associations between calcinosis, digital ischaemia and capillary dropout. Results. One thousand three hundred and five patients were included in this study, of whom 300 (23.0%) had calcinosis at study entry. In a cross-sectional multivariate analysis, at baseline, calcinosis was associated with digital ischaemia (odds ratio (OR) = 2.37, 95% CI: 1.66, 3.39), severity of ischaemia (OR = 1.12, 95% CI: 1.06, 1.18), capillary dropout (OR = 1.41, 95% CI: 1.05, 1.89), ACAs (OR = 1.68, 95% CI: 1.17, 2.43) and anti-RNA polymerase III antibodies (OR = 1.77, 95% CI: 1.08, 2.89). Current use of calcium channel blockers was inversely associated with the presence of calcinosis (OR = 0.70, 95% CI: 0.52, 0.96). Of the 805 patients with no calcinosis at study entry and at least one follow-up visit, 215 (26.7%) developed calcinosis during follow-up. Significant baseline predictors of the development of calcinosis in follow-up were digital ischaemia (hazard ratio (HR) = 1.82, 95% CI: 1.30, 2.54), capillary dropout (HR = 1.46, 95% CI: 1.08, 1.99), dcSSc (HR = 1.57, 95% CI: 1.11, 2.21), ACA (HR = 2.18, 95% CI: 1.50, 3.17) and anti-RNA polymerase III antibodies (HR = 2.58, 95% CI: 1.65, 4.04). Conclusion. Ischaemia may play a role in the development of calcinosis in SSc. PMID:27593964

Lentiviral vector mediated modification of mesenchymal stem cells & enhanced survival in an in vitro model of ischaemia.

LENUS (Irish Health Repository)

McGinley, Lisa

2012-01-31

INTRODUCTION: A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. METHODS: Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-alpha-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. RESULTS: The second generation lentiviral vector rHIV-pWPT-EF1-alpha-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. CONCLUSIONS: Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

Lentiviral vector mediated modification of mesenchymal stem cells & enhanced survival in an in vitro model of ischaemia

LENUS (Irish Health Repository)

McGinley, Lisa

2011-03-07

Abstract Introduction A combination of gene and cell therapies has the potential to significantly enhance the therapeutic value of mesenchymal stem cells (MSCs). The development of efficient gene delivery methods is essential if MSCs are to be of benefit using such an approach. Achieving high levels of transgene expression for the required period of time, without adversely affecting cell viability and differentiation capacity, is crucial. In the present study, we investigate lentiviral vector-mediated genetic modification of rat bone-marrow derived MSCs and examine any functional effect of such genetic modification in an in vitro model of ischaemia. Methods Transduction efficiency and transgene persistence of second and third generation rHIV-1 based lentiviral vectors were tested using reporter gene constructs. Use of the rHIV-pWPT-EF1-α-GFP-W vector was optimised in terms of dose, toxicity, cell species, and storage. The in vivo condition of ischaemia was modelled in vitro by separation into its associated constituent parts i.e. hypoxia, serum and glucose deprivation, in which the effect of therapeutic gene over-expression on MSC survival was investigated. Results The second generation lentiviral vector rHIV-pWPT-EF1-α-GFP-W, was the most efficient and provided the most durable transgene expression of the vectors tested. Transduction with this vector did not adversely affect MSC morphology, viability or differentiation potential, and transgene expression levels were unaffected by cryopreservation of transduced cells. Over-expression of HSP70 resulted in enhanced MSC survival and increased resistance to apoptosis in conditions of hypoxia and ischaemia. MSC differentiation capacity was significantly reduced after oxygen deprivation, but was preserved with HSP70 over-expression. Conclusions Collectively, these data validate the use of lentiviral vectors for efficient in vitro gene delivery to MSCs and suggest that lentiviral vector transduction can facilitate

Topical application of recombinant platelet-derived growth factor increases the rate of healing and the level of proteins that regulate this response.

Science.gov (United States)

Gowda, Santosh; Weinstein, David A; Blalock, Timothy D; Gandhi, Kavita; Mast, Bruce A; Chin, Gloria; Schultz, Gregory S

2015-10-01

A bipedicle ischaemic rat skin flap model was used to study the effects of daily topical applications of platelet-derived growth factor (PDGF) on the healing of ischaemic wounds. Levels of tumour necrosis factor-alpha (TNFA), interleukin 1-beta (IL1B) and both the latent and active forms of matrix metalloproteinase 2 (MMP2) and 9 (MMP9) were measured. Full-thickness wounds were made on a total of 72 adult male Sprague-Dawley rats. Each group of 18 rats with normal and ischaemic wounds received either vehicle or 0·01% recombinant PDGF-BB. Additional applications were made on the wounds on a daily basis. Wound areas were measured at 0, 1, 3, 5, 7 9 and 13 days after wounding. Ischaemia caused a delay in wound healing as well as an increase in TNFA, IL1B and both the pro and active forms of MMP2 and MMP9. PDGF accelerated the rate of wound healing in both normal and ischaemic wounds and negated the effect of ischaemia. PDGF reduced the TNFA concentration in both normal and ischaemic wounds, and the rate of wound healing closely resembled the pattern of TNFA protein expression. PDGF also reduced both the magnitude and duration of the increases in IL1B and both the pro and active forms of MMP2 and MMP9 induced by ischaemia. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

1,8-Cineole ameliorates oxygen-glucose deprivation/reoxygenation-induced ischaemic injury by reducing oxidative stress in rat cortical neuron/glia.

Science.gov (United States)

Ryu, Sangwoo; Park, Hyeon; Seol, Geun Hee; Choi, In-Young

2014-12-01

1,8-Cineole, the main monoterpene in many essential oils, has been used as an ingredient in flavourings and medicine. 1,8-Cineole has been shown to possess pharmacological properties, including anti-oxidative, anti-inflammatory and anti-nociceptive actions. However, to date, no studies have examined the potential of 1,8-cineole to protect against cerebral ischaemic injury. In this study, we investigated the neuroprotective effects of 1,8-cineole against cortical neuronal/glial cell injury caused by oxygen-glucose deprivation/reoxygenation (OGD/R) in an in-vitro model of ischaemia. 1,8-Cineole significantly attenuated OGD/R-induced cortical cell injury, as well as reduced n-methyl-d-aspartate (NMDA)-induced cell injury. However, it did not inhibit NMDA-induced cytosolic calcium overload. Nevertheless, 1,8-cineole significantly reduced the OGD/R- and NMDA-induced overproduction of reactive oxygen species (ROS). These results indicate that 1,8-cineole exerts neuroprotection through its anti-oxidative rather than its anti-excitotoxic, properties. The decrease in OGD/R-induced intracellular superoxide in 1,8-cineole-treated cortical cells was associated with the upregulation of superoxide dismutase activity. Moreover, 1,8-cineole showed direct ROS scavenging activity in an assay of oxygen radical absorbance capacity. Collectively, these results suggest 1,8-cineole as a potentially effective neuroprotective and anti-oxidative candidate for the treatment of patients with ischaemic stroke. © 2014 Royal Pharmaceutical Society.

Management of renal dysfunction following term perinatal hypoxia-ischaemia.

LENUS (Irish Health Repository)

Sweetman, Deirdre U

2013-03-01

Acute kidney injury frequently develops following the term perinatal hypoxia-ischaemia. Quantifying the degree of acute kidney injury is difficult, however, as the methods currently in use are suboptimal. Acute kidney injury management is largely supportive with little evidence basis for many interventions. This review discusses management strategies and novel biomarkers that may improve diagnosis and management of renal injury following perinatal hypoxia-ischaemia.

Calcinosis is associated with digital ischaemia in systemic sclerosis-a longitudinal study.

Science.gov (United States)

Baron, Murray; Pope, Janet; Robinson, David; Jones, Niall; Khalidi, Nader; Docherty, Peter; Kaminska, Elzbieta; Masetto, Ariel; Sutton, Evelyn; Mathieu, Jean-Pierre; Ligier, Sophie; Grodzicky, Tamara; LeClercq, Sharon; Thorne, Carter; Gyger, Geneviève; Smith, Douglas; Fortin, Paul R; Larché, Maggie; Abu-Hakima, Maysan; Rodriguez-Reyna, Tatiana S; Cabral-Castaneda, Antonio R; Fritzler, Marvin J; Wang, Mianbo; Hudson, Marie

2016-12-01

To determine if ischaemia is a causal factor in the development of calcinosis in SSc. Patients with SSc were assessed yearly. Physicians reported the presence of calcinosis, digital ischaemia (digital ulcers, digital necrosis/gangrene, loss of digital pulp on any digits and/or auto- or surgical digital amputation) and nailfold capillary dropout assessed using a dermatoscope. The number of digits with digital ischaemia was used as an assessment of the severity of digital ischaemia. SSc specific antibodies were detected with a line immunoassay. Multiple logistic regression and Cox proportional hazards models were generated to determine associations between calcinosis, digital ischaemia and capillary dropout. One thousand three hundred and five patients were included in this study, of whom 300 (23.0%) had calcinosis at study entry. In a cross-sectional multivariate analysis, at baseline, calcinosis was associated with digital ischaemia (odds ratio (OR) = 2.37, 95% CI: 1.66, 3.39), severity of ischaemia (OR = 1.12, 95% CI: 1.06, 1.18), capillary dropout (OR = 1.41, 95% CI: 1.05, 1.89), ACAs (OR = 1.68, 95% CI: 1.17, 2.43) and anti-RNA polymerase III antibodies (OR = 1.77, 95% CI: 1.08, 2.89). Current use of calcium channel blockers was inversely associated with the presence of calcinosis (OR = 0.70, 95% CI: 0.52, 0.96). Of the 805 patients with no calcinosis at study entry and at least one follow-up visit, 215 (26.7%) developed calcinosis during follow-up. Significant baseline predictors of the development of calcinosis in follow-up were digital ischaemia (hazard ratio (HR) = 1.82, 95% CI: 1.30, 2.54), capillary dropout (HR = 1.46, 95% CI: 1.08, 1.99), dcSSc (HR = 1.57, 95% CI: 1.11, 2.21), ACA (HR = 2.18, 95% CI: 1.50, 3.17) and anti-RNA polymerase III antibodies (HR = 2.58, 95% CI: 1.65, 4.04). Ischaemia may play a role in the development of calcinosis in SSc. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology

Modelling far field pacing for terminating spiral waves pinned to ischaemic heterogeneities in cardiac tissue

Science.gov (United States)

Boccia, E.; Luther, S.

2017-01-01

In cardiac tissue, electrical spiral waves pinned to a heterogeneity can be unpinned (and eventually terminated) using electric far field pulses and recruiting the heterogeneity as a virtual electrode. While for isotropic media the process of unpinning is much better understood, the case of an anisotropic substrate with different conductivities in different directions still needs intensive investigation. To study the impact of anisotropy on the unpinning process, we present numerical simulations based on the bidomain formulation of the phase I of the Luo and Rudy action potential model modified due to the occurrence of acute myocardial ischaemia. Simulating a rotating spiral wave pinned to an ischaemic heterogeneity, we compare the success of sequences of far field pulses in the isotropic and the anisotropic case for spirals still in transient or in steady rotation states. Our results clearly indicate that the range of pacing parameters resulting in successful termination of pinned spiral waves is larger in anisotropic tissue than in an isotropic medium. This article is part of the themed issue ‘Mathematical methods in medicine: neuroscience, cardiology and pathology’. PMID:28507234

Spinal cord stimulation for chronic pain of neuropathic or ischaemic origin: systematic review and economic evaluation.

Science.gov (United States)

Simpson, E L; Duenas, A; Holmes, M W; Papaioannou, D; Chilcott, J

2009-03-01

This report addressed the question 'What is the clinical and cost-effectiveness of spinal cord stimulation (SCS) in the management of chronic neuropathic or ischaemic pain?' Thirteen electronic databases [including MEDLINE (1950-2007), EMBASE (1980-2007) and the Cochrane Library (1991-2007)] were searched from inception; relevant journals were hand-searched; and appropriate websites for specific conditions causing chronic neuropathic/ischaemic pain were browsed. Literature searches were conducted from August 2007 to September 2007. A systematic review of the literature sought clinical and cost-effectiveness data for SCS in adults with chronic neuropathic or ischaemic pain with inadequate response to medical or surgical treatment other than SCS. Economic analyses were performed to model the cost-effectiveness and cost-utility of SCS in patients with neuropathic or ischaemic pain. From approximately 6000 citations identified, 11 randomised controlled trials (RCTs) were included in the clinical effectiveness review: three of neuropathic pain and eight of ischaemic pain. Trials were available for the neuropathic conditions failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS) type I, and they suggested that SCS was more effective than conventional medical management (CMM) or reoperation in reducing pain. The ischaemic pain trials had small sample sizes, meaning that most may not have been adequately powered to detect clinically meaningful differences. Trial evidence failed to demonstrate that pain relief in critical limb ischaemia (CLI) was better for SCS than for CMM; however, it suggested that SCS was effective in delaying refractory angina pain onset during exercise at short-term follow-up, although not more so than coronary artery bypass grafting (CABG) for those patients eligible for that surgery. The results for the neuropathic pain model suggested that the cost-effectiveness estimates for SCS in patients with FBSS who had inadequate

40 CFR 80.52 - Vehicle preconditioning.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Vehicle preconditioning. 80.52 Section...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.52 Vehicle preconditioning. (a) Initial vehicle preconditioning and preconditioning between tests with different fuels shall be performed in...

HIF-1alpha and HIF-2alpha are differentially activated in distinct cell populations in retinal ischaemia.

Directory of Open Access Journals (Sweden)

Freya M Mowat

2010-06-01

Full Text Available Hypoxia plays a key role in ischaemic and neovascular disorders of the retina. Cellular responses to oxygen are mediated by hypoxia-inducible transcription factors (HIFs that are stabilised in hypoxia and induce the expression of a diverse range of genes. The purpose of this study was to define the cellular specificities of HIF-1alpha and HIF-2alpha in retinal ischaemia, and to determine their correlation with the pattern of retinal hypoxia and the expression profiles of induced molecular mediators.We investigated the tissue distribution of retinal hypoxia during oxygen-induced retinopathy (OIR in mice using the bio-reductive drug pimonidazole. We measured the levels of HIF-1alpha and HIF-2alpha proteins by Western blotting and determined their cellular distribution by immunohistochemistry during the development of OIR. We measured the temporal expression profiles of two downstream mediators, vascular endothelial growth factor (VEGF and erythropoietin (Epo by ELISA. Pimonidazole labelling was evident specifically in the inner retina. Labelling peaked at 2 hours after the onset of hypoxia and gradually declined thereafter. Marked binding to Müller glia was evident during the early hypoxic stages of OIR. Both HIF-1alpha and HIF-2alpha protein levels were significantly increased during retinal hypoxia but were evident in distinct cellular distributions; HIF-1alpha stabilisation was evident in neuronal cells throughout the inner retinal layers whereas HIF-2alpha was restricted to Müller glia and astrocytes. Hypoxia and HIF-alpha stabilisation in the retina were closely followed by upregulated expression of the downstream mediators VEGF and EPO.Both HIF-1alpha and HIF-2alpha are activated in close correlation with retinal hypoxia but have contrasting cell specificities, consistent with differential roles in retinal ischaemia. Our findings suggest that HIF-2alpha activation plays a key role in regulating the response of Müller glia to hypoxia.

Acute mesenteric ischemia and duodenal ulcer perforation: a unique double pathology

Directory of Open Access Journals (Sweden)

Haruna Lois

2012-10-01

Full Text Available Abstract Background Acute mesenteric ischaemia and duodenal perforation are surgical emergencies with serious consequences. Patients presenting with acute mesenteric ischaemia alone face a high mortality rate as high as 60% whereas those presenting with peptic ulcer perforation the mortality rates range from 6-14%. There are very few reported cases of patients presenting with this dual pathology. Case presentation We report a unique case of a 53 year old Italian lady who presented with acute mesenteric ischaemia and duodenal perforation. This is the first report of massive bowel ischaemia and duodenal perforation with no apparent underlying common pathophysiology leading to this presentation. Conclusion Early management in the intensive care unit and appropriate surgical intervention maximised the patient’s chances of survival despite the poor prognosis associated with her dual pathology. The rare pathology of the patient described can be explained by two possible hypotheses: peptic ulcer disease causing duodenal ulceration, which precipitated ischaemic infarction of the small bowel. The second hypothesis is the patient developed a stress related ulcer following ischaemic bowel infarction secondary to arterial thrombosis.

Acute upper arm ischaemia: a rare presentation of non-Hodgkin's lymphoma.

LENUS (Irish Health Repository)

Daruwalla, Z J

2010-12-01

Digital ischaemia has been sparsely reported in current literature. Its association with lymphomatous conditions has been described in even more exceptional occurrences. We present the first case of upper arm ischaemia associated with non-Hodgkin\\'s lymphoma. A brief literature review of this rare phenomenon is also accompanied with it.

[sup 99]Tc[sup m]-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease

Energy Technology Data Exchange (ETDEWEB)

Sciammarella, M.G.; Fragasso, G.; Gerundini, P.; Maffioli, L.; Cappelletti, A.; Margonato, A.; Savi, A.; Chierchia, S. (Istituto Scientifico H San Raffaele, Milan (Italy). Dept. of Nuclear Medicine)

1992-12-01

The ability of [sup 99]Tc[sup m]-methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients with clinically recognised ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise 90 min after injection of [sup 99]Tc[sup m]-MIBI. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities. In conclusion, MIBI SPET is a highly reliable technique for assessing the presence and location of myocardial ischaemia and necrosis. (Author).

Spontaneous ischaemic stroke in dogs

DEFF Research Database (Denmark)

Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

2013-01-01

Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

Cardioprotective effects of benazepril, an angiotensin-converting enzyme inhibitor, in an ischaemia-reperfusion model of myocardial infarction in rats.

Science.gov (United States)

Charan Sahoo, Kanhei; Arora, Sachin; Goyal, Sameer; Kishore, Kamal; Ray, Ruma; Chandra Nag, Tapas; Singh Arya, Dharamvir

2009-12-01

The present study evaluated the effects of benazepril, an angiotensin-converting enzyme inhibitor on haemodynamic, biochemical, and immunohistochemical (Bax and Bcl-2 protein) indices in ischaemia and reperfusion (IR) injury. Male Wistar albino rats were divided into three groups and were orally administered saline once daily (IR-sham and IR-control) or benazepril (30 mg/kg/day; IR-benazepril) for 14 days. On the 15(th) day, in the IR-control and IR-benazepril groups, rats were subjected to left anterior descending coronary artery occlusion for 45 minutes followed by a one-hour reperfusion. Haemodynamic parameters were recorded and rats were sacrificed; hearts were isolated for biochemical estimation and immunohistochemistry. In the IR-control group, significant ventricular dysfunctions (pBenazepril pretreatment significantly improved mean arterial pressure (pbenazepril treatment significantly decreased the level of thiobarbituric acid reactive substances and restored the activity of lactate dehydrogenase towards normal value (pbenazepril upregulated Bcl-2 protein and decreased Bax protein expression, thus exhibiting anti-apoptotic effects. These beneficial effects of benazepril will have an important implication in the therapeutic use of benazepril in ischaemic heart disease.

Trombolyse og akut myokardieinfarkt. Mindre restiskoemi ved førstegangs akut myokardieinfarkt

DEFF Research Database (Denmark)

Mickley, H F; Pless, P; Nielsen, J R

1994-01-01

% in reperfused patients versus 62% in controls. During 36-hour ambulatory ST-segment monitoring, however, the duration of myocardial ischaemia was significantly reduced in thrombolyzed patients: 322 minutes versus 1144 minutes in controls (p work capacity...... in thrombolyzed patients compared with controls: 160 +/- 41 versus 139 +/- 34 W (p reduces residual myocardial ischaemia. The reduced ischaemic burden is assumed...

Honey improves spermatogenesis and hormone secretion in testicular ischaemia-reperfusion-induced injury in rats.

Science.gov (United States)

Gholami, M; Abbaszadeh, A; Khanipour Khayat, Z; Anbari, K; Baharvand, P; Gharravi, A M

2018-02-01

This study was conducted to survey the protective effect of pre-treatment with Persian honey during post-ischaemia reperfusion on ischaemia-reperfusion (IR)-induced testis injury. Animals were divided into four groups of IR, honey + ischaemia- reperfusion (HIR), vitamin C + ischaemia- reperfusion (VIR) and carbohydrates + ischaemia- reperfusion (CIR). The testes were examined for spermatogenesis index. Detection of single- and double-stranded DNA breaks at the early stages of apoptosis was performed. Total serum concentration of FSH, LH and testosterone was measured using ELISA. All data were expressed as mean ± SD in each group, and significance was set at p ≤ .05. Spermatogenesis index was significant in the HIR group (p honey decreases the cellular damage and apoptosis during testicular I/R injury, with significant protective effects on reproductive hormone production. © 2017 Blackwell Verlag GmbH.

Expanding concepts in ischaemic heart disease: implications for clinical practice and research

International Nuclear Information System (INIS)

Maseri, A.; Pasceri, V.; Giordano, A.; Trani, C.

1996-01-01

In the late Eighties, a series of observations from several institutions around the world has dramatically revolutionized the traditional notion that the occurrence of myocardial infarction was related most of the time to the development of critical flow-limiting coronary stenosis. All these studies showed that the infarct-related artery had only minimal or mild stenosis in about two thirds of the cases. Therefore, contrary to our previous beliefs, in clinical practice the detection of coronary stenosis has a lesser role in the prognostic assessment of patients with ischaemic heart disease, unless associated with extensive ischemia or with phases of instability. In fact, the major determinants of prognosis are represented by age, left ventricular function, effort tolerance and especially by the clinical stability or instability of angina. According to the Bayesian an theorem, in low risk patients any diagnostic test has a very low predictive accuracy, unless very high specificity criteria are used. The value of diagnostic tests in the assessment of patients' prognosis should be evaluated in intermediate risk groups. The emphasis of clinical research has, therefore, shifted from the detection of flow-limiting stenosis to the study of the multiple and varied dynamic causes of stable and unstable ischaemia, where the possibilities of making new, seminal observations are greater

Noble gases as cardioprotectants - translatability and mechanism

NARCIS (Netherlands)

Smit, Kirsten F.; Weber, Nina C.; Hollmann, Markus W.; Preckel, Benedikt

2015-01-01

Several noble gases, although classified as inert substances, exert a tissue-protective effect in different experimental models when applied before organ ischaemia as an early or late preconditioning stimulus, after ischaemia as a post-conditioning stimulus or when given in combination before,

Mice Lacking the β2 Adrenergic Receptor Have a Unique Genetic Profile before and after Focal Brain Ischaemia

Directory of Open Access Journals (Sweden)

Robin E White

2012-08-01

Full Text Available The role of the β2AR (β2 adrenergic receptor after stroke is unclear as pharmacological manipulations of the β2AR have produced contradictory results. We previously showed that mice deficient in the β2AR (β2KO had smaller infarcts compared with WT (wild-type mice (FVB after MCAO (middle cerebral artery occlusion, a model of stroke. To elucidate mechanisms of this neuroprotection, we evaluated changes in gene expression using microarrays comparing differences before and after MCAO, and differences between genotypes. Genes associated with inflammation and cell deaths were enriched after MCAO in both genotypes, and we identified several genes not previously shown to increase following ischaemia (Ccl9, Gem and Prg4. In addition to networks that were similar between genotypes, one network with a central core of GPCR (G-protein-coupled receptor and including biological functions such as carbohydrate metabolism, small molecule biochemistry and inflammation was identified in FVB mice but not in β2KO mice. Analysis of differences between genotypes revealed 11 genes differentially expressed by genotype both before and after ischaemia. We demonstrate greater Glo1 protein levels and lower Pmaip/Noxa mRNA levels in β2KO mice in both sham and MCAO conditions. As both genes are implicated in NF-κB (nuclear factor κB signalling, we measured p65 activity and TNFα (tumour necrosis factor α levels 24 h after MCAO. MCAO-induced p65 activation and post-ischaemic TNFα production were both greater in FVB compared with β2KO mice. These results suggest that loss of β2AR signaling results in a neuroprotective phenotype in part due to decreased NF-κB signalling, decreased inflammation and decreased apoptotic signalling in the brain.

Phobic anxiety and ischaemic heart disease.

Science.gov (United States)

Haines, A P; Imeson, J D; Meade, T W

1987-08-01

A prospective study of the relation between scores on the six subscales of the Crown-Crisp experiential index and subsequent incidence of ischaemic heart disease was undertaken among participants in the Northwick Park heart study. Results from 1457 white men aged 40-64 at recruitment showed that phobic anxiety was strongly related to subsequent major ischaemic heart disease (fatal and non-fatal events combined) when other associated variables were taken into account. The phobic anxiety score alone remained significantly associated with ischaemic heart disease when scores on all the subscales were included in the analysis. Phobic anxiety seemed to be particularly associated with fatal ischaemic heart disease but was not associated with deaths from other causes and was no higher in those with a pre-existing myocardial infarction at recruitment than in those without. There was a consistent increase in risk of fatal ischaemic heart disease with score on the phobic anxiety subscale. The relative risk for those whose score was 5 and above was 3.77 (95% confidence interval 1.64 to 8.64) compared with those whose score was 0 or 1. The 49 participants with evidence of myocardial infarction at recruitment had higher scores on the subscales for free floating anxiety and functional somatic complaint. The Crown-Crisp experiential index is simple to fill out and acceptable to patients. When the results are combined with other known risk factors it may be of use in defining high risk subjects and in planning strategies for prevention.

Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

International Nuclear Information System (INIS)

Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E.; El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria; Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke; Kroft, Lucia J.; Younis, Imad Al; Reiber, Johan H.; Scholte, Arthur J.

2013-01-01

Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 ± 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS ≥2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p 2 = 20.7) and lesion length (χ 2 = 26.0) to the clinical variables and the visual assessment (χ 2 = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have incremental value over baseline variables and visually assessed significant stenosis. Potentially, QCT can refine assessment of CAD, which may be of potential use for identification of patients with myocardial ischaemia. (orig.)

The structure of the polynomials in preconditioned BiCG algorithms and the switching direction of preconditioned systems

OpenAIRE

Itoh, Shoji; Sugihara, Masaaki

2016-01-01

We present a theorem that defines the direction of a preconditioned system for the bi-conjugate gradient (BiCG) method, and we extend it to preconditioned bi-Lanczos-type algorithms. We show that the direction of a preconditioned system is switched by construction and by the settings of the initial shadow residual vector. We analyze and compare the polynomial structures of four preconditioned BiCG algorithms.

NAD+ depletion or PAR polymer formation: which plays the role of executioner in ischaemic cell death?

Science.gov (United States)

Siegel, C; McCullough, L D

2011-09-01

Multiple cell death pathways are activated in cerebral ischaemia. Much of the initial injury, especially in the core of the infarct where cerebral blood flow is severely reduced, is necrotic and secondary to severe energy failure. However, there is considerable evidence that delayed cell death continues for several days, primarily in the penumbral region. As reperfusion therapies grow in number and effectiveness, restoration of blood flow early after injury may lead to a shift towards apoptosis. It is important to elucidate what are the key mediators of apoptotic cell death after stroke, as inhibition of apoptosis may have therapeutic implications. There are two well described pathways that lead to apoptotic cell death; the caspase pathway and the more recently described caspase-independent pathway triggered by poly-ADP-ribose polymers (PARP) activation. Caspase-induced cell death is initiated by release of mitochondrial cytochrome c, formation of the cytosolic apoptosome, and activation of endonucleases leading to a multitude of small randomly cleaved DNA fragments. In contrast caspase-independent cell death is secondary to activation of apoptosis inducing factor (AIF). Mitochondrial AIF translocates to the nucleus, where it induces peripheral chromatin condensation, as well as characteristic high-molecular-weight (50 kbp) DNA fragmentation. Although caspase-independent cell death has been recognized for some time and is known to contribute to ischaemic injury, the upstream triggering events leading to activation of this pathway remain unclear. The two major theories are that ischaemia leads to nicotinamide adenine dinucleotide (NAD+) depletion and subsequent energy failure, or alternatively that cell death is directly triggered by a pro-apoptotic factor produced by activation of the DNA repair enzyme PARP. PARP activation is robust in the ischaemic brain producing variable lengths of poly-ADP-ribose (PAR) polymers as byproducts of PARP activation. PAR polymers

Scintigraphy of the heart using thallium-201 and its clinical implications

International Nuclear Information System (INIS)

Jambroes, G.; Rijk, P.P. van; Graaf, C.N. de; Berg, C.J.M. van de

1975-01-01

Primary results are presented of myocardial scintigraphy using thallium-201. It is shown that myocardial infarction can be traced with this method in recent infarctions as well in healed myocardial injury. Ischaemic areas in the myocardium cannot be distinguished from infarction if occurring at rest. Ischaemia at exercise however is demonstrable if ischaemic ST-T changes occur

Reversible non-ischaemic cardiomyopathy and left ventricular dysfunction after liver transplantation: a single-centre experience.

Science.gov (United States)

Yataco, Maria L; Difato, Thomas; Bargehr, Johannes; Rosser, Barry G; Patel, Tushar; Trejo-Gutierrez, Jorge F; Pungpapong, Surakit; Taner, C Burcin; Aranda-Michel, Jaime

2014-07-01

Non-ischaemic cardiomyopathy (NIC) is an early complication of liver transplantation (LT). Our aims were to define the prevalence, associated clinical factors, and prognosis of this condition. A retrospective study was performed on patients undergoing LT at our institution from January 2005 to December 2012. Patients who developed NIC were identified. Data collected included demographic and clinical data. A total 1460 transplants were performed in this period and seventeen patients developed NIC. Pretransplant median QTc interval was 459 (range, 405-530), and median E/A ratio was 1 (range, 0.71-1.67). Fourteen patients (82%) were severely malnourished and required nutritional support. Thirteen patients (76%) had renal insufficiency. Median time to onset was 2 days post-transplant (range, 0-20). Echocardiograms showed global left ventricular hypokinesis and a decrease in ejection fraction (EF) from a median of 65% (range, 50-81) pretransplant to a median of 21% (range, 15-32). Median raw model for end-stage liver disease (MELD) score was 29 in patients with NIC vs. 18 in patients without cardiomyopathy (P = 0.01). There was no significant difference between recipients with NIC vs. recipients without cardiomyopathy regarding donor age, donor risk index, and cold and warm ischaemia time. Recovery of cardiac function occurred in 16 patients, with a median EF of 44% (range, 25-65%) at the time of discharge. The last echocardiogram available showed a median EF of 59% (range, 49-73%). One-year survival of NIC patients was 94.1%. Non-ischaemic cardiomyopathy is a rare complication after LT. Patients with NIC are critically ill, with high MELD score, and severe malnutrition. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Acute Ischaemic Colitis- A Case Report

Directory of Open Access Journals (Sweden)

M Basra

2012-03-01

Full Text Available Acute ischaemic colitis (AIC is being increasingly recognised as an uncommon cause of abdominal pain associated with fresh bleeding per rectum. It is paramount to maintain a high index of suspicion and adopt appropriate management strategies to avoid complications and inappropriate interventions. In this paper, we describe a case of AIC and review literature pertinent to the management of this condition. Keywords: Ischaemic colitis, acute abdomen, management.

Intestinal Ischaemia-Reperfusion Injury and Semen Characteristics ...

African Journals Online (AJOL)

olayemitoyin

Nigeria. Summary: Increasing production of goats takes their reproductive ... of testicular damage and infertility and is a form of ischaemia-reperfusion injury. ... concentration, percentage of normal sperm cells, abnormal sperm cells and ...

Ischaemic heart disease

DEFF Research Database (Denmark)

Houlberg Hansen, Louise; Mikkelsen, Søren

2013-01-01

Purpose. Correct prehospital diagnosis of ischaemic heart disease (IHD) may accelerate and improve the treatment. We sought to evaluate the accuracy of prehospital diagnoses of ischemic heart diseases assigned by physicians. Methods. The Mobile Emergency Care Unit (MECU) in Odense, Denmark...

Protective effects of Rosmarinic acid against renal ischaemia/reperfusion injury in rats

International Nuclear Information System (INIS)

Ozturk, H.; Ozturk, H.; Terzi, E.H.

2014-01-01

Objective: To investigate the potential protective effects of Rosmarinic acid (RA) on rats exposed to ischaemia/reperfusion renal injury. Methods: The prospective study was conducted at Abant Izzet Baysal University, Turkey, and comprised 21 male Spraque Dawley rats weighing 250-270g each. They were divided into three equal groups. Unilaterally nephrectomised rats were subjected to 60 minutes of left renal ischaemia followed by 60 minutes of reperfusion. Group 1 had shamoperated animals; group 2 had ischaemia/reperfusion untreated animals; and group 3 had ischaemia/reperfusion animals treated with rosmarinic acid. Serum creatinine, blood urea nitrogen, tissue malondialdehyde, glutathione peroxidase, superoxide dismutase and myeloperoxidase (MPO) activities, and light microscopic findings were evaluated. SPSS 17 was used for statistical analysis. Results: Treatment of rats with rosmarinic acid produced a reduction in the serum levels of creatinine and blood urea nitrogen compared to the other groups. However, no statistically significant difference was found. The levels of malondialdehyde and myeloperoxidase were decreased in the renal tissue of group 3, while glutathione peroxidose and superoxide dismutase levels remained unchanged. The injury score decreased in the treatment group rats compared to the untreated group. Rosmarinic acid significantly decreased focal glomerular necrosis, dilatation of Bowman's capsule, degeneration of tubular epithelium, necrosis in tubular epithelium, and tubular dilatation. Conclusions: Rosmarinic acid prevented ischaemia/reperfusion injury in the kidneys by decreasing oxidative stress. (author)

Measurement of ischaemia-reperfusion in patients with intermittent claudication using NMR-based metabonomics.

NARCIS (Netherlands)

Coolen, S.A.; Daykin, C.A.; Duynhoven, J.P. van; Dorsten, F.A. van; Wulfert, F.; Mathot, J.; Scheltinga, M.R.M.; Stroosma, O.; Vader, H.L.; Wijnen, M.H.W.A.

2008-01-01

Intermittent claudication has proved to be a good in vivo model for ischaemia-reperfusion. For assessment of ischaemia-reperfusion damage, the known biochemical markers all have disadvantages with respect to sensitivity and interference with other physiological events. In this work, we studied the

The detection of brain ischaemia in rats by inductive phase shift spectroscopy

International Nuclear Information System (INIS)

González, C A; Villanueva, C; Vera, C; Flores, O; Reyes, R D; Rubinsky, B

2009-01-01

Ischaemia in the brain is an important clinical problem that is often monitored and studied with expensive devices such as MRI and PET, which are not readily available in low economical resource parts of the world. We have developed a new less expensive tool for non-invasive monitoring of ischaemia in the brain. This is a first feasibility study describing the concept. The system is based on the hypothesis that electromagnetic properties of the tissue change during ischaemia and that measuring the electromagnetic properties of the bulk of the brain with non-contact means can detect these changes. The apparatus we have built and whose design we describe here consists of two electromagnetic coils placed around the head. The system measures the bulk change in time of the phase difference between the electromagnetic signal on the two coils in a range of frequencies. A mathematical model simulating the device and the measurement is also introduced. Ischaemia was induced in the brain of rats by occlusion of the right cerebral and carotid arteries. Experimental subjects were monitored for 24 h. Inductive phase shift measurements were made at five frequencies in the range of 0.1–50 MHz eight times during the observation period. An ex vivo estimation of the percentage of necrosis in the ischemic subjects at t = 24 h was done. The mathematical model was also applied to the experimental tested situation. The results of both experiments and theory show significant phase shifts increase as a function of frequency and ischaemia time. The theoretical and experimental results suggest that the tested technique has the potential to detect the processes and level of ischaemia in the brain by non-invasive, continuous, bulk volumetric monitoring with a simple and inexpensive apparatus

Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

Energy Technology Data Exchange (ETDEWEB)

Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of The Netherlands, Utrecht (Netherlands); El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Kroft, Lucia J. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Younis, Imad Al [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Reiber, Johan H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical imaging systems B.V., Leiden (Netherlands); Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

2013-08-15

Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 {+-} 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS {>=}2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p < 0.001, and OR 1.07, 95 % CI 1.00-1.45, p = 0.032, respectively) after correcting for clinical variables and visually assessed significant stenosis. The addition of quantitatively assessed significant stenosis ({chi} {sup 2} = 20.7) and lesion length ({chi} {sup 2} = 26.0) to the clinical variables and the visual assessment ({chi} {sup 2} = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have

Application of streptokinase and PTA in lower limb chronic ischaemia

International Nuclear Information System (INIS)

Syberyjski, R.; Domanski, Z.; Cyrylowski, L.

1994-01-01

In 14 patients with chronic ischaemia of lower limbs, local fibrynolysis with streptokinase followed by PTA was performed in occluded arteries. The procedure was successful in 10 patients. An adverse reaction was observed in 1 patient (gingivorrhea), and a complication was noticed in another one (acute ischaemia due a trombosis). These results suggest that the method may appear as a safe alternative to a surgery treatment, and encourage to evaluate an effectiveness of the procedure in a large group of patients. (author)

Phobic anxiety and ischaemic heart disease.

OpenAIRE

Haines, A P; Imeson, J D; Meade, T W

1987-01-01

A prospective study of the relation between scores on the six subscales of the Crown-Crisp experiential index and subsequent incidence of ischaemic heart disease was undertaken among participants in the Northwick Park heart study. Results from 1457 white men aged 40-64 at recruitment showed that phobic anxiety was strongly related to subsequent major ischaemic heart disease (fatal and non-fatal events combined) when other associated variables were taken into account. The phobic anxiety score ...

Acute myeloid leukaemia as a cause of acute ischaemic heart disease

NARCIS (Netherlands)

van Haelst, P.L.; Schot, Bart; Hoendermis, E.S.; van den Berg, M.P.

2006-01-01

Ischaemic heart disease is almost invariably the result of atherosclerotic degeneration of the coronary arteries. However, other causes of ischaemic heart disease should always be considered. Here we describe two patients with a classic presentation of ischaemic heart disease resulting from acute

Effect of 5-aminosalicylic acid on myocardial capillary permeability following ischaemia and reperfusion

DEFF Research Database (Denmark)

Hansen, P R; Svendsen, Jesper Hastrup; Høst, N B

1992-01-01

The aim was to evaluate the effect of 5-aminosalicylic acid on myocardial capillary permeability for small hydrophilic molecules after ischaemia and reperfusion.......The aim was to evaluate the effect of 5-aminosalicylic acid on myocardial capillary permeability for small hydrophilic molecules after ischaemia and reperfusion....

Ischemic preconditioning protects against ischemic brain injury

Directory of Open Access Journals (Sweden)

Xiao-meng Ma

2016-01-01

Full Text Available In this study, we hypothesized that an increase in integrin αv ß 3 and its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αv ß 3, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αv ß 3 and vascular endothelial growth factor levels in the brain following ischemia.

Cooling for newborns with hypoxic ischaemic encephalopathy.

Science.gov (United States)

Jacobs, Susan E; Berg, Marie; Hunt, Rod; Tarnow-Mordi, William O; Inder, Terrie E; Davis, Peter G

2013-01-31

Newborn animal studies and pilot studies in humans suggest that mild hypothermia following peripartum hypoxia-ischaemia in newborn infants may reduce neurological sequelae without adverse effects. To determine the effect of therapeutic hypothermia in encephalopathic asphyxiated newborn infants on mortality, long-term neurodevelopmental disability and clinically important side effects. We used the standard search strategy of the Cochrane Neonatal Review Group as outlined in The Cochrane Library (Issue 2, 2007). Randomised controlled trials evaluating therapeutic hypothermia in term and late preterm newborns with hypoxic ischaemic encephalopathy were identified by searching the Oxford Database of Perinatal Trials, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2007, Issue 2), MEDLINE (1966 to June 2007), previous reviews including cross-references, abstracts, conferences, symposia proceedings, expert informants and journal handsearching. We updated this search in May 2012. We included randomised controlled trials comparing the use of therapeutic hypothermia with standard care in encephalopathic term or late preterm infants with evidence of peripartum asphyxia and without recognisable major congenital anomalies. The primary outcome measure was death or long-term major neurodevelopmental disability. Other outcomes included adverse effects of cooling and 'early' indicators of neurodevelopmental outcome. Four review authors independently selected, assessed the quality of and extracted data from the included studies. Study authors were contacted for further information. Meta-analyses were performed using risk ratios (RR) and risk differences (RD) for dichotomous data, and weighted mean difference for continuous data with 95% confidence intervals (CI). We included 11 randomised controlled trials in this updated review, comprising 1505 term and late preterm infants with moderate/severe encephalopathy and evidence of intrapartum asphyxia

Abdominal symptoms during physical exercise and the role of gastrointestinal ischaemia: a study in 12 symptomatic athletes.

Science.gov (United States)

ter Steege, Rinze W F; Geelkerken, Robert H; Huisman, Ad B; Kolkman, Jeroen J

2012-10-01

Gastrointestinal (GI) symptoms during exercise may be caused by GI ischaemia. The authors report their experience with the diagnostic protocol and management of athletes with symptomatic exercise-induced GI ischaemia. The value of prolonged exercise tonometry in the diagnostic protocol of these patients was evaluated. Patients referred for GI symptoms during physical exercise underwent a standardised diagnostic protocol, including prolonged exercise tonometry. Indicators of GI ischaemia, as measured by tonometry, were related to the presence of symptoms during the exercise test (S+ and S- tests) and exercise intensity. 12 athletes were specifically referred for GI symptoms during exercise (five males and seven females; median age 29 years (range 15-46 years)). Type of sport was cycling, long-distance running and triathlon. Median duration of symptoms was 32 months (range 7-240 months). Splanchnic artery stenosis was found in one athlete. GI ischaemia was found in six athletes during submaximal exercise. All athletes had gastric and jejunal ischaemia during maximum intensity exercise. No significant difference was found in gastric and jejunal Pco(2) or gradients between S+ and S- tests during any phase of the exercise protocol. In S+ tests, but not in S- tests, a significant correlation between lactate and gastric gradient was found. In S+ tests, the regression coefficients of gradients were higher than those in S- tests. Treatment advice aimed at limiting GI ischaemia were successful in reducing complaints in the majority of the athletes. GI ischaemia was present in all athletes during maximum intensity exercise and in 50% during submaximal exercise. Athletes with GI symptoms had higher gastric gradients per mmol/l increase in lactate, suggesting an increased susceptibility for the development of ischaemia during exercise. Treatment advice aimed at limiting GI ischaemia helped the majority of the referred athletes to reduce their complaints. Our results suggest an

Limb remote-preconditioning protects against focal ischemia in rats and contradicts the dogma of therapeutic time windows for preconditioning

Science.gov (United States)

Ren, Chuancheng; Gao, Xuwen; Steinberg, Gary K.; Zhao, Heng

2009-01-01

Remote ischemic preconditioning is an emerging concept for stroke treatment, but its protection against focal stroke has not been established. We tested whether remote preconditioning, performed in the ipsilateral hind limb, protects against focal stroke and explored its protective parameters. Stroke was generated by a permanent occlusion of the left distal middle cerebral artery (MCA) combined with a 30 minute occlusion of the bilateral common carotid arteries (CCA) in male rats. Limb preconditioning was generated by 5 or 15 minute occlusion followed with the same period of reperfusion of the left hind femoral artery, and repeated for 2 or 3 cycles. Infarct was measured 2 days later. The results showed that rapid preconditioning with 3 cycles of 15 minutes performed immediately before stroke reduced infarct size from 47.7±7.6% of control ischemia to 9.8±8.6%; at 2 cycles of 15 minutes, infarct was reduced to 24.7±7.3%; at 2 cycles of 5 minutes, infarct was not reduced. Delayed preconditioning with 3 cycles of 15 minutes conducted 2 days before stroke also reduced infarct to 23.0 ±10.9%, but with 2 cycles of 15 minutes it offered no protection. The protective effects at these two therapeutic time windows of remote preconditioning are consistent with those of conventional preconditioning, in which the preconditioning ischemia is induced in the brain itself. Unexpectedly, intermediate preconditioning with 3 cycles of 15 minutes performed 12 hours before stroke also reduced infarct to 24.7±4.7%, which contradicts the current dogma for therapeutic time windows for the conventional preconditioning that has no protection at this time point. In conclusion, remote preconditioning performed in one limb protected against ischemic damage after focal cerebral ischemia. PMID:18201834

Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial.

Science.gov (United States)

Halkes, P H A; van Gijn, J; Kappelle, L J; Koudstaal, P J; Algra, A

2006-05-20

Results of trials of aspirin and dipyridamole combined versus aspirin alone for the secondary prevention of vascular events after ischaemic stroke of presumed arterial origin are inconsistent. Our aim was to resolve this uncertainty. We did a randomised controlled trial in which we assigned patients to aspirin (30-325 mg daily) with (n=1363) or without (n=1376) dipyridamole (200 mg twice daily) within 6 months of a transient ischaemic attack or minor stroke of presumed arterial origin. Our primary outcome event was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever happened first. Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with (NCT00161070). Mean follow-up was 3.5 years (SD 2.0). Median aspirin dose was 75 mg in both treatment groups (range 30-325); extended-release dipyridamole was used by 83% (n=1131) of patients on the combination regimen. Primary outcome events arose in 173 (13%) patients on aspirin and dipyridamole and in 216 (16%) on aspirin alone (hazard ratio 0.80, 95% CI 0.66-0.98; absolute risk reduction 1.0% per year, 95% CI 0.1-1.8). Addition of the ESPRIT data to the meta-analysis of previous trials resulted in an overall risk ratio for the composite of vascular death, stroke, or myocardial infarction of 0.82 (95% CI 0.74-0.91). Patients on aspirin and dipyridamole discontinued trial medication more often than those on aspirin alone (470 vs 184), mainly because of headache. The ESPRIT results, combined with the results of previous trials, provide sufficient evidence to prefer the combination regimen of aspirin plus dipyridamole over aspirin alone as antithrombotic therapy after cerebral ischaemia of arterial origin.

Ischaemic colitis associated with carcinoma of the colon

International Nuclear Information System (INIS)

Reeders, J.W.A.; Rosenbusch, B.; Tytgat, G.N.J.

1982-01-01

In a retrospective study of one hundred and seventy patients with ischaemic colitis, we found eight patients with partially obstructive carcinoma of the colon located distally, seven located in the sigmoid and one in the splenic flexure. The frequency of this association (1-4.7% in the literature and 5.3% in our series) requires careful examination by radiologist and surgeon. The radiologist should be alert to the association of ischaemic damage proximal to an obstructive colorectal cancer. The surgeon must examine any colonic segment removed for carcinoma in order to exclude an ischaemic process in the area of the anastomosis and prevent leakage at the anastomosis or stricture formation. (orig.)

Renal blood flow and metabolism after cold ischaemia: peroperative measurements in patients with calculi

DEFF Research Database (Denmark)

Petersen, H K; Henriksen, Jens Henrik Sahl

1984-01-01

Peroperative measurements of renal blood flow (RBF), renal O2-uptake, and renal venous lactate/pyruvate (L/P) ratio were performed before and after a period of 30-71 min of hypothermic (10-15 degrees C) renal ischaemia in nine patients, undergoing surgery for renal calculi. Before ischaemia, RBF.......01) immediately after re-established perfusion and 36% (P less than 0.02) 30 min later. In one additional patient, who had a short warm ischaemia (8 min), the flow pattern was the same. As arterial pressure remained constant, the reduced RBF signifies an increased renal vascular resistance. Renal O2-uptake...... and renal venous L/P ratio were almost constant, indicating no significant anaerobic processes being involved in the flow response. None of the patients showed any signs of reactive hyperaemia. It is concluded that hypothermic renal ischaemia may be followed by an increased renal vascular resistance even...

Automatic classification of transient ischaemic and transient non-ischaemic heart-rate related ST segment deviation episodes in ambulatory ECG records

International Nuclear Information System (INIS)

Faganeli, J; Jager, F

2010-01-01

In ambulatory ECG records, besides transient ischaemic ST segment deviation episodes, there are also transient non-ischaemic heart-rate related ST segment deviation episodes present, which appear only due to a change in heart rate and thus complicate automatic detection of true ischaemic episodes. The goal of this work was to automatically classify these two types of episodes. The tested features to classify the ST segment deviation episodes were changes of heart rate, changes of the Mahalanobis distance of the first five Karhunen–Loève transform (KLT) coefficients of the QRS complex, changes of time-domain morphologic parameters of the ST segment and changes of the Legendre orthonormal polynomial coefficients of the ST segment. We chose Legendre basis functions because they best fit typical shapes of the ST segment morphology, thus allowing direct insight into the ST segment morphology changes through the feature space. The classification was performed with the help of decision trees. We tested the classification method using all records of the Long-Term ST Database on all ischaemic and all non-ischaemic heart-rate related deviation episodes according to annotation protocol B. In order to predict the real-world performance of the classification we used second-order aggregate statistics, gross and average statistics, and the bootstrap method. We obtained the best performance when we combined the heart-rate features, the Mahalanobis distance and the Legendre orthonormal polynomial coefficient features, with average sensitivity of 98.1% and average specificity of 85.2%

Potassium channels in brain mitochondria.

Science.gov (United States)

Bednarczyk, Piotr

2009-01-01

Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

Platelet degranulation and monocyte-platelet complex formation are increased in the acute and convalescent phases after ischaemic stroke or transient ischaemic attack.

LENUS (Irish Health Repository)

McCabe, Dominick J H

2004-06-01

Flow cytometric studies suggest that platelets are activated in ischaemic stroke or transient ischaemic attack (TIA). However, few studies have measured circulating leucocyte-platelet complexes in this patient population. Whole blood flow cytometry was used to quantify the expression of CD62P-, CD63-, and PAC1-binding, and the percentages of leucocyte-platelet complexes in acute (1-27 d, n = 79) and convalescent (79-725 d, n = 70) ischaemic cerebrovascular disease (CVD) patients compared with controls without CVD (n = 27). We performed a full blood count, and measured plasma levels of soluble P-selectin, soluble E-selectin, and von Willebrand factor antigen (VWF:Ag) as additional markers of platelet and\\/or endothelial cell activation. The median percentage CD62P expression and the median percentage monocyte-platelet complexes were higher in both acute and convalescent CVD patients than controls (P <\\/= 0.02). The mean white cell count and mean VWF:Ag levels were significantly elevated in the acute and convalescent phases after ischaemic stroke or TIA (P <\\/= 0.02). Otherwise, there was no significant increase in any other marker of platelet or endothelial activation in CVD patients. There was a positive correlation between the percentage expression of CD62P and the percentages of both neutrophil-platelet and monocyte-platelet complexes in the acute phase, and the percentages of all leucocyte-platelet complexes in the convalescent phase after ischaemic CVD. This study provides evidence for ongoing excessive platelet and\\/or endothelial activation in ischaemic CVD patients despite treatment with antithrombotic therapy.

Lower limb ischaemia and reperfusion injury in healthy volunteers measured by oxidative and inflammatory biomarkers

DEFF Research Database (Denmark)

Halladin, N. L.; Busch, Sarah Victoria Ekeløf; Alamili, M.

2015-01-01

OBJECTIVE: Ischaemia-reperfusion (IR) injury is partly caused by the release of reactive oxygen species and cytokines and may result in remote organ injury. Surgical patients are exposed to surgical stress and anaesthesia, both of which can influence the IR response. An IR model without these int......OBJECTIVE: Ischaemia-reperfusion (IR) injury is partly caused by the release of reactive oxygen species and cytokines and may result in remote organ injury. Surgical patients are exposed to surgical stress and anaesthesia, both of which can influence the IR response. An IR model without...... at any sampling time. CONCLUSION: Twenty minutes of lower limb ischaemia does not result in an ischaemia-reperfusion injury in healthy volunteers, measurable by oxidative and pro- and anti-inflammatory biomarkers in muscle biopsies and in the systemic circulation....

Electrocardiogram ST-Segment Morphology Delineation Method Using Orthogonal Transformations.

Directory of Open Access Journals (Sweden)

Miha Amon

Full Text Available Differentiation between ischaemic and non-ischaemic transient ST segment events of long term ambulatory electrocardiograms is a persisting weakness in present ischaemia detection systems. Traditional ST segment level measuring is not a sufficiently precise technique due to the single point of measurement and severe noise which is often present. We developed a robust noise resistant orthogonal-transformation based delineation method, which allows tracing the shape of transient ST segment morphology changes from the entire ST segment in terms of diagnostic and morphologic feature-vector time series, and also allows further analysis. For these purposes, we developed a new Legendre Polynomials based Transformation (LPT of ST segment. Its basis functions have similar shapes to typical transient changes of ST segment morphology categories during myocardial ischaemia (level, slope and scooping, thus providing direct insight into the types of time domain morphology changes through the LPT feature-vector space. We also generated new Karhunen and Lo ève Transformation (KLT ST segment basis functions using a robust covariance matrix constructed from the ST segment pattern vectors derived from the Long Term ST Database (LTST DB. As for the delineation of significant transient ischaemic and non-ischaemic ST segment episodes, we present a study on the representation of transient ST segment morphology categories, and an evaluation study on the classification power of the KLT- and LPT-based feature vectors to classify between ischaemic and non-ischaemic ST segment episodes of the LTST DB. Classification accuracy using the KLT and LPT feature vectors was 90% and 82%, respectively, when using the k-Nearest Neighbors (k = 3 classifier and 10-fold cross-validation. New sets of feature-vector time series for both transformations were derived for the records of the LTST DB which is freely available on the PhysioNet website and were contributed to the LTST DB. The

Induction of interleukin-1β mRNA after focal cerebral ischaemia in the rat

NARCIS (Netherlands)

Buttini, M.; Sauter, A.; Boddeke, H.W.G.M.

1994-01-01

The expression of interleukin-1β (IL-1β) mRNA in the brain in response to cerebral ischaemia in rats was examined using in situ hybridization histochemistry. Focal cerebral ischaemia was induced in spontaneously hypertensive rats by permanent occlusion of the left middle cerebral artery (MCAO).

Ischaemia and insulin, but not ischaemia and contraction, act synergistically in stimulating muscle glucose uptake in vivo in humans.

NARCIS (Netherlands)

Bosselaar, M.; Smits, P.; Tack, C.J.J.

2009-01-01

Ischaemia, like muscle contraction, has been reported to induce skeletal muscle glucose uptake in in vitro models. This stimulating effect appears independent of insulin and is probably mediated by activation of AMPK (AMP-activated protein kinase). In the present study, we hypothesized that in vivo

An integrative review of health-related quality of life in patients with critical limb ischaemia.

Science.gov (United States)

Monaro, Susan; West, Sandra; Gullick, Janice

2017-10-01

To examine the domains and the domain-specific characteristics within a peripheral arterial disease health-related quality of life framework for their usefulness in defining critical limb ischaemia health-related quality of life. Critical Limb Ischaemia presents a highly individualised set of personal and health circumstances. Treatment options include conservative management, revascularisation or amputation. However, the links between treatment decisions and quality of life require further investigation. The framework for this integrative review was the peripheral arterial disease-specific health-related quality of life domains identified by Treat-Jacobson et al. The literature expanded and refined Treat-Jacobson's framework by modifying the characteristics to better describe health-related quality of life in critical limb ischaemia. Given that critical limb ischaemia is a highly individualised situation with powerful health-related quality of life implications, further research focusing on patient and family-centred decision-making relating to therapeutic options and advanced care planning is required. A critical limb ischaemia-specific, health-related quality of life tool is required to capture both the unique characteristics of this disorder, and the outcomes for active or conservative care among this complex group of patients. © 2016 John Wiley & Sons Ltd.

Preconditioning, postconditioning and their application to clinical cardiology.

Science.gov (United States)

Kloner, Robert A; Rezkalla, Shereif H

2006-05-01

Ischemic preconditioning is a well-established phenomenon first described in experimental preparations in which brief episodes of ischemia/reperfusion applied prior to a longer coronary artery occlusion reduce myocardial infarct size. There are ample correlates of ischemic preconditioning in the clinical realm. Preconditioning mimetic agents that stimulate the biochemical pathways of ischemic preconditioning and protect the heart without inducing ischemia have been examined in numerous experimental studies. However, despite the effectiveness of ischemic preconditioning and preconditioning mimetics for protecting ischemic myocardium, there are no preconditioning-based therapies that are routinely used in clinical medicine at the current time. Part of the problem is the need to administer therapy prior to the known ischemic event. Other issues are that percutaneous coronary intervention technology has advanced so far (with the development of stents and drug-eluting stents) that ischemic preconditioning or preconditioning mimetics have not been needed in most interventional cases. Recent clinical trials such as AMISTAD I and II (Acute Myocardial Infarction STudy of ADenosine) suggest that some preconditioning mimetics may reduce myocardial infarct size when given along with reperfusion or, as in the IONA trial, have benefit on clinical events when administered chronically in patients with known coronary artery disease. It is possible that some of the benefit described for adenosine in the AMISTAD 1 and 2 trials represents a manifestation of the recently described postconditioning phenomenon. It is probable that postconditioning--in which reperfusion is interrupted with brief coronary occlusions and reperfusion sequences--is more likely than preconditioning to be feasible as a clinical application to patients undergoing percutaneous coronary intervention for acute myocardial infarction.

Ischaemia-reperfusion injury: a major protagonist in kidney transplantation.

Science.gov (United States)

Ponticelli, Claudio

2014-06-01

Ischaemia-reperfusion injury (IRI) is a frequent event in kidney transplantation, particularly when the kidney comes from a deceased donor. The brain death is usually associated with generalized ischaemia due to a hyperactivity of the sympathetic system. In spite of this, most donors have profound hypotension and require administration of vasoconstrictor agents. Warm ischaemia after kidney vessels clamping and the cold ischaemia after refrigeration also reduce oxygen and nutrients supply to tissues. The reperfusion further aggravates the state of oxidation and inflammation created by ischaemia. IRI first attacks endothelial cells and tubular epithelial cells. The lesions may be so severe that they lead to acute kidney injury (AKI) and delayed graft function (DGF), which can impair the graft survival. The unfavourable impact of DGF is worse when DGF is associated with acute rejection. Another consequence of IRI is the activation of the innate immunity. Danger signals released by dying cells alarm Toll-like receptors that, through adapter molecules and a chain of kinases, transmit the signal to transcription factors which encode the genes regulating inflammatory cells and mediators. In the inflammatory environment, dendritic cells (DCs) intercept the antigen, migrate to lymph nodes and present the antigen to immunocompetent cells, so activating the adaptive immunity and favouring rejection. Attempts to prevent IRI include optimal management of donor and recipient. Calcium-channel blockers, l-arginine and N-acetylcysteine could obtain a small reduction in the incidence of post-transplant DGF. Fenoldopam, Atrial Natriuretic Peptide, Brain Natriuretic Peptide and Dopamine proved to be helpful in reducing the risk of AKI in experimental models, but there is no controlled evidence that these agents may be of benefit in preventing DGF in kidney transplant recipients. Other antioxidants have been successfully used in experimental models of AKI but only a few studies of poor

Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

International Nuclear Information System (INIS)

Depresseux, J.C.; Franck, G.; Van Cauwenberge, H.

1987-01-01

Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple [fr

Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Depresseux, J C; Franck, G., Van Cauwenberge, H.

1987-06-18

Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple.

A nested mechanistic sub-study into the effect of tranexamic acid versus placebo on intracranial haemorrhage and cerebral ischaemia in isolated traumatic brain injury: study protocol for a randomised controlled trial (CRASH-3 Trial Intracranial Bleeding Mechanistic Sub-Study [CRASH-3 IBMS]).

Science.gov (United States)

Mahmood, Abda; Roberts, Ian; Shakur, Haleema

2017-07-17

Tranexamic acid prevents blood clots from breaking down and reduces bleeding. However, it is uncertain whether tranexamic acid is effective in traumatic brain injury. The CRASH-3 trial is a randomised controlled trial that will examine the effect of tranexamic acid (versus placebo) on death and disability in 13,000 patients with traumatic brain injury. The CRASH-3 trial hypothesizes that tranexamic acid will reduce intracranial haemorrhage, which will reduce the risk of death. Although it is possible that tranexamic acid will reduce intracranial bleeding, there is also a potential for harm. In particular, tranexamic acid may increase the risk of cerebral thrombosis and ischaemia. The protocol detailed here is for a mechanistic sub-study nested within the CRASH-3 trial. This mechanistic sub-study aims to examine the effect of tranexamic acid (versus placebo) on intracranial bleeding and cerebral ischaemia. The CRASH-3 Intracranial Bleeding Mechanistic Sub-Study (CRASH-3 IBMS) is nested within a prospective, double-blind, multi-centre, parallel-arm randomised trial called the CRASH-3 trial. The CRASH-3 IBMS will be conducted in a cohort of approximately 1000 isolated traumatic brain injury patients enrolled in the CRASH-3 trial. In the CRASH-3 IBMS, brain scans acquired before and after randomisation are examined, using validated methods, for evidence of intracranial bleeding and cerebral ischaemia. The primary outcome is the total volume of intracranial bleeding measured on computed tomography after randomisation, adjusting for baseline bleeding volume. Secondary outcomes include progression of intracranial haemorrhage (from pre- to post-randomisation scans), new intracranial haemorrhage (seen on post- but not pre-randomisation scans), intracranial haemorrhage following neurosurgery, and new focal ischaemic lesions (seen on post-but not pre-randomisation scans). A linear regression model will examine whether receipt of the trial treatment can predict haemorrhage

Preconditioned iterations to calculate extreme eigenvalues

Energy Technology Data Exchange (ETDEWEB)

Brand, C.W.; Petrova, S. [Institut fuer Angewandte Mathematik, Leoben (Austria)

1994-12-31

Common iterative algorithms to calculate a few extreme eigenvalues of a large, sparse matrix are Lanczos methods or power iterations. They converge at a rate proportional to the separation of the extreme eigenvalues from the rest of the spectrum. Appropriate preconditioning improves the separation of the eigenvalues. Davidson`s method and its generalizations exploit this fact. The authors examine a preconditioned iteration that resembles a truncated version of Davidson`s method with a different preconditioning strategy.

Coronary plaque quantification and fractional flow reserve by coronary computed tomography angiography identify ischaemia-causing lesions

DEFF Research Database (Denmark)

Gaur, Sara; Øvrehus, Kristian Altern; Dey, Damini

2016-01-01

AIMS: Coronary plaque characteristics are associated with ischaemia. Differences in plaque volumes and composition may explain the discordance between coronary stenosis severity and ischaemia. We evaluated the association between coronary stenosis severity, plaque characteristics, coronary computed...... tomography angiography (CTA)-derived fractional flow reserve (FFRCT), and lesion-specific ischaemia identified by FFR in a substudy of the NXT trial (Analysis of Coronary Blood Flow Using CT Angiography: Next Steps). METHODS AND RESULTS: Coronary CTA stenosis, plaque volumes, FFRCT, and FFR were assessed...

Short communication:Intestinal Ischaemia-Reperfusion Injury and ...

African Journals Online (AJOL)

This study investigates the effect of intestinal ischaemia-reperfusion (IIR) injury on semen characteristics in WAD bucks. Six healthy adult male ... Many of the abnormalities involved midpiece and tail abnormalities which are very vital to propulsion and may cause an inability of the sperm cells to fertilize. This hitherto silent ...

Milrinone and levosimendan during porcine myocardial ischemia -- no effects on calcium overload and metabolism.

Science.gov (United States)

Axelsson, B; Johansson, G; Abrahamsson, P; Gupta, A; Tydén, H; Wouters, P; Haney, M

2013-07-01

Although inotropic stimulation is considered harmful in the presence of myocardial ischaemia, both calcium sensitisers and phosphodiesterase inhibitors may offer cardioprotection. We hypothesise that these cardioprotective effects are related to an acute alteration of myocardial metabolism. We studied in vivo effects of milrinone and levosimendan on calcium overload and ischaemic markers using left ventricular microdialysis in pigs with acute myocardial ischaemia. Anaesthetised juvenile pigs, average weight 36 kg, were randomised to one of three intravenous treatment groups: milrinone 50 μg/kg bolus plus infusion 0.5 μg/kg/min (n = 7), levosimendan 24 μg/kg plus infusion 0.2 μg/kg/min (n = 7), or placebo (n = 6) for 60 min prior to and during a 45 min acute regional coronary occlusion. Systemic and myocardial haemodynamics were assessed, and microdialysis was performed with catheters positioned in the left ventricular wall. (45) Ca(2+) was included in the microperfusate in order to assess local calcium uptake into myocardial cells. The microdialysate was analysed for glucose, lactate, pyruvate, glycerol, and for (45) Ca(2+) recovery. During ischaemia, there were no differences in microdialysate-measured parameters between control animals and milrinone- or levosimendan-treated groups. In the pre-ischaemic period, arterial blood pressure decreased in all groups while myocardial oxygen consumption remained stable. These findings reject the hypothesis of an immediate energy-conserving effect of milrinone and levosimendan during acute myocardial ischaemia. On the other hand, the data show that inotropic support with milrinone and levosimendan does not worsen the metabolic parameters that were measured in the ischaemic myocardium. © 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Myocardial perfusion imaging in hyperthrophic cardiomyopathy

International Nuclear Information System (INIS)

Moorin, B.

1998-01-01

Full text: Patients with Hyperthrophic Cardiomyopathy (HCM) frequently suffer from syncope and cardiac arrest which may lead to sudden death. This is most often caused by ventricular arrhythmia's in adults, however in young patients the mechanisms are thought to be different. Ischaemia may play a significant role even in young asymptomatic HCM patients. The mechanisms of ischaemic development in HCM differ from those in the 'normal' myocardium (Due to intramural small vessel abnormalities and abnormal myocellular architecture). In HCM the coronary microcirculation is most often affected and massive hypertrophy means more energy is required to promote contraction thus increasing oxygen demand and compounding the effects of any ischaemic changes. A case of a 12 year old HCM patient is presented who has symptoms of syncope associated with exercise whose mother died suddenly of cardiac arrest developed from HCM. A myocardial perfusion rest/stress study was undertaken to detect any underlying myocardial ischaemia. Myocardial perfusion scintigraphy demonstrates any reduction in the microcirculation in addition to that present in the macrocirculation, unlike angiography which will only detect the latter. In this case the scan clearly showed evidence of ischaemia in the lateral wall and this may be an explanation for her episodes of syncope. We suggest an algorithm or the routine work-up of young patients with HCM which makes aggressive use of myocardial perfusion imaging to detect ischaemic changes. This may identify patients who are at higher risk and will assist with treatment decisions. We feel myocardial perfusion scintigraphy is a sensitive non-invasive accurate method of detecting microcirculatory ischaemia and is thus invaluable in HCM patients

Modulation of ASIC channels in rat cerebellar purkinje neurons by ischaemia-related signals

Science.gov (United States)

Allen, Nicola J; Attwell, David

2002-01-01

Acid-sensing ion channels (ASICs), activated by a decrease of extracellular pH, are found in neurons throughout the nervous system. They have an amino acid sequence similar to that of ion channels activated by membrane stretch, and have been implicated in touch sensation. Here we characterize the pH-dependent activation of ASICs in cerebellar Purkinje cells and investigate how they are modulated by factors released in ischaemia. Lowering the external pH from 7.4 activated an inward current at −66 mV, carried largely by Na+ ions, which was half-maximal for a step to pH 6.4 and was blocked by amiloride and gadolinium. The H+-gated current desensitized within a few seconds, but approximately 30% of cells showed a sustained inward current (11% of the peak current) in response to the maintained presence of pH 6 solution. The peak H+-evoked current was potentiated by membrane stretch (which occurs in ischaemia when [K+]o rises) and by arachidonic acid (which is released when [Ca2+]i rises in ischaemia). Arachidonic acid increased to 77% the fraction of cells showing a sustained current evoked by acid pH. The ASIC currents were also potentiated by lactate (which is released when metabolism becomes anaerobic in ischaemia) and by FMRFamide (which may mimic the action of related mammalian RFamide transmitters). These data reinforce suggestions of a mechanosensory aspect to ASIC channel function, and show that the activation of ASICs reflects the integration of multiple signals which are present during ischaemia. PMID:12205186

[Cold ischaemia time and outcome of renal transplantation].

NARCIS (Netherlands)

Warle, M.C.; Cheung, C.L.; Teerenstra, S.; Hoitsma, A.J.; Vliet, J.A. van der

2010-01-01

OBJECTIVE: To determine the effect of cold ischaemia time (CIT) on the outcome of cadaveric renal transplantation in the Netherlands. DESIGN: Retrospective, comparative. METHODS: We studied data from the Netherlands organ transplant registry of cadaveric renal transplants from 1990-2007. Results :

ST depression and left ventricular haemodynamics during exercise in patients with angina pectoris.

Science.gov (United States)

Carlens, P; Holmgren, A; Jonasson, R; Landou, C; Orinius, E

1983-01-01

The mechanism of ischaemic ST depression and the cause of its low sensitivity to coronary artery stenosis are not well understood. Of 30 patients with severe stable effort angina, 19 (63%) showed ischaemic ST depressions after exercise (the STAE group) and 11 did not. The highest load during the symptom-limited exercise test and the heart rate on that load did not differ between the two groups. The clinical characteristics and angiographic findings were also similar, but the findings at heart catheterization differed during exercise (in supine). Although the load was similar, the stroke index was significantly lower (38 vs. 53 ml/m2 BSA) and the left ventricular end-diastolic pressure rose to a significantly higher value in the STAE group (40 vs. 32 mmHg). When STAE occurred, they were exclusively or concomitantly present in chest lead 5. These findings suggest that ischaemic STAE may not reflect regional ischaemia but the consequent left ventricular dysfunction. The mechanism may, for example, be that a sufficiently elevated left ventricular diastolic pressure causes a global subendocardial ischaemia.

Prevention of reperfusion lung injury by lidocaine in isolated rat lung ventilated with higher oxygen levels.

Directory of Open Access Journals (Sweden)

Das K

2003-01-01

Full Text Available BACKGROUND: Lidocaine, an antiarrhythmic drug has been shown to be effective against post-ischaemic reperfusion injury in heart. However, its effect on pulmonary reperfusion injury has not been investigated. AIMS: We investigated the effects of lidocaine on a postischaemic reperfused rat lung model. MATERIALS AND METHODS: Lungs were isolated and perfused at constant flow with Krebs-Henseilet buffer containing 4% bovine serum albumin, and ventilated with 95% oxygen mixed with 5% CO2. Lungs were subjected to ischaemia by stopping perfusion for 60 minutes followed by reperfusion for 10 minutes. Ischaemia was induced in normothermic conditions. RESULTS: Postischaemic reperfusion caused significant (p < 0.0001 higher wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure compared to control lungs. Lidocaine, at a dose of 5mg/Kg b.w. was found to significantly (p < 0.0001 attenuate the increase in the wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure observed in post-ischaemic lungs. CONCLUSION: Lidocaine is effective in preventing post-ischaemic reperfusion injury in isolated, perfused rat lung.

Aerosolized PGE1, PGI2 and nitroprusside protect against vascular leakage in lung ischaemia-reperfusion.

Science.gov (United States)

Schütte, H; Löckinger, A; Seeger, W; Grimminger, F

2001-07-01

High permeability oedema is an important feature in lung injury secondary to ischaemia-reperfusion. This study investigated the influence of aerosolized prostaglandin E1 (PGE1), prostaglandin I2 (PCI2) and the nitric oxide (NO)-donor, sodium nitroprusside (SNP) on microvascular barrier function in pulmonary ischaemia-reperfusion. Buffer-perfused rabbit lungs were exposed to 180 or 210 min of warm ischaemia while maintaining anoxic ventilation and a positive intravascular pressure. Reperfusion provoked a transient, mostly precapillary elevation of vascular resistance, followed by a severe increase of the capillary filtration coefficient (Kfc) versus nonischaemic controls (3.17+/-0.34 versus 0.85+/-0.05 cm3 x s(-1) cmH2O(-1) x g(-1) x 10(-4) after 30 min of reperfusion), and progressive oedema formation. Short-term aerosolization of SNP, PGE1 or PGI2 at the beginning of ischaemia largely suppressed the Kfc increase (1.36+/-0.22, 1.32+/-0.23 and 1.32+/-0.22 cm3 x s(-1) x cmH2O(-1) x g(-1) x 10(-4), respectively) and oedema formation. In contrast, application prior to reperfusion was much less effective, with some reduction of Kfc increase by PGI2 and SNP and no effect of PGE, (1.79+/-0.31, 2.2+/-0.53 and 3.2+/-0.05 cm3 x s(-1) x cmH2O(-1) x g(-1) x 10(-4), respectively). Haemodynamics, including microvascular pressure, were only marginally affected by the chosen doses of aerosolized vasodilators. It is concluded that short-term aerosolization of prostaglandin E1, prostaglandin I2 and sodium nitroprusside at the onset of ischaemia is highly effective in maintaining endothelial barrier properties in pulmonary ischaemia-reperfusion. This effect is apparently attributable to nonvasodilatory mechanisms exerted by these agents. Alveolar deposition of prostaglandins and/or nitric oxide donors by the aerosol technique may offer pulmonary protection in ischaemia-reperfusion injury.

MR tomography in myocardial ischaemia: present state of the art

International Nuclear Information System (INIS)

Szolar, D.H.; Saeed, M.; Higgins, C.B.

1996-01-01

Recent developments in MR imaging have opened up new avenues in the investigation of ischaemic heart disease. Conventional unenhanced spin-echo sequences have been used to detect and quantify myocardial infarction. Along with the technical advances aimed at reducing motion artifacts and imaging time, the advent of contrast media for MR imaging has further strengthened its diagnostic capacities. The applications of MR contrast media are increasing, and they are becoming more specific, to enable differentiation of occlusive and reperfused myocardial infarctions and to discriminate between reversible and irreversible myocardial injury. Previous studies have also indicated that dual administration of both relaxivity-based and susceptibility-based contrast media can be used to determine whether viable myocardium is present in the reperfused ischaemic area. Magnetic susceptibility MR contrast media have the potential to demonstrate a region of the ischaemically injured myocardium in which myocardial necrosis is present. A cornestone in the MR assessment of ischaemic heart disease has been achieved with the advent of fast MR imaging techniques. Ultrafast gradient-recalled-echo sequences or echoplanar imaging allow to monitor the first passage of the contrast medium through the heart. With the aid of MR contrast media, these techniques may be useful in estimating regional myocardial perfusion and blood volume. Experimental and clinical perfusion studies indicate that perfusion-sensitive MR imaging, particularly in concert with coronary vasodilators, can detect compromised myocardium. Combining myocardial perfusion imaging with the anatomic and functional information provided by other MR imaging techniques such as cine and velocity-encoded sequences could make MR imaging a comprehensive noninvasive diagnostic tool for the assessment of ischaemic heart disease. (orig.) [de

Radial optic neurotomy for ischaemic central vein occlusion

Science.gov (United States)

Martínez-Jardón, C S; Meza-de Regil, A; Dalma-Weiszhausz, J; Leizaola-Fernández, C; Morales-Cantón, V; Guerrero-Naranjo, J L; Quiroz-Mercado, H

2005-01-01

Background/aims: Ischaemic central retinal vein occlusion (CRVO) accounts for 20–50% of all CRVO. No treatment has been proved to be effective. The efficacy of radial optic neurotomy (RON) was evaluated in eyes with ischaemic CRVO. Methods: 10 patients with ischaemic CRVO underwent RON. After pars plana vitrectomy, a microvitreoretinal blade was used to incise the scleral ring, cribriform plate, and adjacent sclera at the nasal edge of the optic disc. Best corrected visual acuity (BCVA), intraocular pressure (IOP), fluorescein angiography (FA), multifocal electroretinography (mfERG), and optical coherence tomography (OCT) were measured preoperatively and at 1, 3, and 6 months postoperatively. Results: No visual improvement was noted in the eyes that underwent RON. FA and mfERG showed no increase in retinal perfusion or retinal function postoperatively. Mean macular central thickness changed from 841 (SD 170) μm preoperatively to 162 (SD 34) μm at the sixth postoperative month. One patient had retinal central artery perforation intraoperatively. One patient developed neovascular glaucoma. Conclusion: RON in ischaemic CRVO did not improve visual function (by mfERG) or visual acuity although macular thickness did improve. This technique may be associated with potential risks. Randomised studies are needed to corroborate these results. PMID:15834084

[Follow-up of newborns with hypoxic-ischaemic encephalopathy].

Science.gov (United States)

Martínez-Biarge, M; Blanco, D; García-Alix, A; Salas, S

2014-07-01

Hypothermia treatment for newborn infants with hypoxic-ischemic encephalopathy reduces the number of neonates who die or have permanent neurological deficits. Although this therapy is now standard of care, neonatal hypoxic-ischaemic encephalopathy still has a significant impact on the child's neurodevelopment and quality of life. Infants with hypoxic-ischaemic encephalopathy should be enrolled in multidisciplinary follow-up programs in order to detect impairments, to initiate early intervention, and to provide counselling and support for families. This article describes the main neurodevelopmental outcomes after term neonatal hypoxic-ischaemic encephalopathy. We offer recommendations for follow-up based on the infant's clinical condition and other prognostic indicators, mainly neonatal neuroimaging. Other aspects, such as palliative care and medico-legal issues, are also briefly discussed. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Quantification of coronary flow reserve in patients with ischaemic and non-ischaemic cardiomyopathy and its association with clinical outcomes.

Science.gov (United States)

Majmudar, Maulik D; Murthy, Venkatesh L; Shah, Ravi V; Kolli, Swathy; Mousavi, Negareh; Foster, Courtney R; Hainer, Jon; Blankstein, Ron; Dorbala, Sharmila; Sitek, Arkadiusz; Stevenson, Lynne W; Mehra, Mandeep R; Di Carli, Marcelo F

2015-08-01

Patients with left ventricular systolic dysfunction frequently show abnormal coronary vascular function, even in the absence of overt coronary artery disease. Moreover, the severity of vascular dysfunction might be related to the aetiology of cardiomyopathy.We sought to determine the incremental value of assessing coronary vascular dysfunction among patients with ischaemic (ICM) and non-ischaemic (NICM) cardiomyopathy at risk for adverse cardiovascular outcomes. Coronary flow reserve (CFR, stress/rest myocardial blood flow) was quantified in 510 consecutive patients with rest left ventricular ejection fraction (LVEF) ≤45% referred for rest/stress myocardial perfusion PET imaging. The primary end point was a composite of major adverse cardiovascular events (MACE) including cardiac death, heart failure hospitalization, late revascularization, and aborted sudden cardiac death.Median follow-up was 8.2 months. Cox proportional hazards model was used to adjust for clinical variables. The annualized MACE rate was 26.3%. Patients in the lowest two tertiles of CFR (CFR ≤ 1.65) experienced higher MACE rates than those in the highest tertile (32.6 vs. 15.5% per year, respectively, P = 0.004), irrespective of aetiology of cardiomyopathy. Impaired coronary vascular function, as assessed by reduced CFR by PET imaging, is common in patients with both ischaemic and non-ischaemic cardiomyopathy and is associated with MACE. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Neuroprotective effects of andrographolide in a rat model of permanent cerebral ischaemia

Science.gov (United States)

Chan, Su Jing; Wong, WS Fred; Wong, Peter TH; Bian, Jin-Song

2010-01-01

BACKGROUND AND PURPOSE Andrographolide is a diterpenoid lactone isolated from a traditional medicinal herb, Andrographis paniculata. It possesses potent anti-inflammatory activity. The present study examined potential therapeutic effects of andrographolide on cerebral ischaemia using a rat model with permanent middle cerebral artery occlusion (pMCAO). EXPERIMENTAL APPROACH The MCA in rats was permanently occluded (by cautery), and 24 h later neurological effects were assessed with behavioural scores. Infarct volume and microglial activation were determined histologically. The p65 form of the transcription factor, nuclear factor-κB (NF-κB), was measured by Western blot, and cytokines by immunoassay of brain extracts. KEY RESULTS Andrographolide, given i.p. 1 h after pMCAO, reduced infarct volume with a maximum reduction of approximately 50% obtained at 0.1 mg·kg−1. Neurological deficits were also reduced by andrographolide, reflecting a correlation between infarct volume and neurological deficits. pMCAO was found to induce activation of microglia and elevate tumour necrosis factor (TNF)-α, interleukin (IL)-1β and prostaglandin (PG)E2 in the ischaemic brain areas. Andrographolide (0.1 mg·kg−1) significantly attenuated or abolished these effects. In addition, andrographolide suppressed the translocation of p65 from cytosol to nucleus, indicating reduced NF-κB activation. CONCLUSIONS AND IMPLICATIONS Andrographolide exhibited neuroprotective effects, with accompanying suppression of NF-κB and microglial activation, and reduction in the production of cytokines including TNF-α and IL-1β, and pro-inflammatory factors such as PGE2. Our findings suggest that andrographolide may have therapeutic value in the treatment of stroke. PMID:20880404

Effects of aspirin on risk and severity of early recurrent stroke after transient ischaemic attack and ischaemic stroke : time-course analysis of randomised trials

NARCIS (Netherlands)

Rothwell, Peter M; Algra, Ale; Chen, Zhengming; Diener, Hans-Christoph; Norrving, Bo; Mehta, Ziyah

2016-01-01

BACKGROUND: Aspirin is recommended for secondary prevention after transient ischaemic attack (TIA) or ischaemic stroke on the basis of trials showing a 13% reduction in long-term risk of recurrent stroke. However, the risk of major stroke is very high for only the first few days after TIA and minor

Dexmedetomidine protects from post-myocardial ischaemia reperfusion lung damage in diabetic rats

Science.gov (United States)

Kip, Gülay; Çelik, Ali; Bilge, Mustafa; Alkan, Metin; Kiraz, Hasan Ali; Özer, Abdullah; Şıvgın, Volkan; Erdem, Özlem; Arslan, Mustafa; Kavutçu, Mustafa

2015-01-01

Objective Diabetic complications and lipid peroxidation are known to have a close association. Lipid peroxidation commonly occurs at sites exposed to ischaemia, but distant organs and tissues also get damaged during ischaemia/reperfusion (I/R). Some of these targets are vital organs, such as the lung, liver, and kidney; the lung is the most frequently affected. The aim of our study was to investigate the effects of dexmedetomidine on I/R damage in lung tissue and on the oxidant/anti-oxidant system in diabetic rats. Material and methods Diabetes was induced with streptozotocin (55 mg/kg) in 18 Wistar Albino rats, which were then randomly divided into three groups (diabetes control (DC), diabetes plus ischaemia-reperfusion (DIR), and diabetes plus dexmedetomidine-ischaemia/reperfusion (DIRD)) after the effects of diabetes were clearly evident. The rats underwent a left thoracotomy and then ischaemia was produced in the myocardium muscle by a left anterior descending artery ligation for 30 min in the DIR and DIRD groups. I/R was performed for 120 min. The DIRD group received a single intraperitoneal dose of dexmedetomidine (100 µg/kg); the DIR group received no dexmedetomidine. Group DC was evaluated as the diabetic control group and also included six rats (C group) in which diabetes was not induced. These mice underwent only left thoracotomy and were closed without undergoing myocardial ischaemia. Histopathological changes, activities of catalase (CAT) and glutathione-S-transferase anti-oxidant enzymes, and malondialdehyde (MDA) levels were evaluated in the lung tissues of all rats. Results Neutrophil infiltration/aggregation was higher in the DIR group than in the C, DC, and DIRD groups (p=0.001, p=0.013, and p=0.042, respectively). The lung injury score was significantly higher in the DIR group than in the C and DC groups (p<0.0001 and p=0.024, respectively). The levels of MDA were significantly higher in the DIR group than in the C and DIRD groups. CAT activity

Dexmedetomidine protects from post-myocardial ischaemia reperfusion lung damage in diabetic rats

Directory of Open Access Journals (Sweden)

Gülay Kip

2015-09-01

Full Text Available Objective: Diabetic complications and lipid peroxidation are known to have a close association. Lipid peroxidation commonly occurs at sites exposed to ischaemia, but distant organs and tissues also get damaged during ischaemia/reperfusion (I/R. Some of these targets are vital organs, such as the lung, liver, and kidney; the lung is the most frequently affected. The aim of our study was to investigate the effects of dexmedetomidine on I/R damage in lung tissue and on the oxidant/anti-oxidant system in diabetic rats. Material and methods: Diabetes was induced with streptozotocin (55 mg/kg in 18 Wistar Albino rats, which were then randomly divided into three groups (diabetes control (DC, diabetes plus ischaemia-reperfusion (DIR, and diabetes plus dexmedetomidine-ischaemia/reperfusion (DIRD after the effects of diabetes were clearly evident. The rats underwent a left thoracotomy and then ischaemia was produced in the myocardium muscle by a left anterior descending artery ligation for 30 min in the DIR and DIRD groups. I/R was performed for 120 min. The DIRD group received a single intraperitoneal dose of dexmedetomidine (100 µg/kg; the DIR group received no dexmedetomidine. Group DC was evaluated as the diabetic control group and also included six rats (C group in which diabetes was not induced. These mice underwent only left thoracotomy and were closed without undergoing myocardial ischaemia. Histopathological changes, activities of catalase (CAT and glutathione-S-transferase anti-oxidant enzymes, and malondialdehyde (MDA levels were evaluated in the lung tissues of all rats. Results: Neutrophil infiltration/aggregation was higher in the DIR group than in the C, DC, and DIRD groups (p=0.001, p=0.013, and p=0.042, respectively. The lung injury score was significantly higher in the DIR group than in the C and DC groups (p<0.0001 and p=0.024, respectively. The levels of MDA were significantly higher in the DIR group than in the C and DIRD groups. CAT

Genetically elevated bilirubin and risk of ischaemic heart disease

DEFF Research Database (Denmark)

Stender, Stefan; Frikke-Schmidt, R; Nordestgaard, B G

2013-01-01

Elevated plasma levels of bilirubin, an endogenous antioxidant, have been associated with reduced risk of ischaemic heart disease (IHD) and myocardial infarction (MI). Whether this is a causal relationship remains unclear.......Elevated plasma levels of bilirubin, an endogenous antioxidant, have been associated with reduced risk of ischaemic heart disease (IHD) and myocardial infarction (MI). Whether this is a causal relationship remains unclear....

Screening and risk evaluation for sudden cardiac death in ischaemic and non-ischaemic cardiomyopathy

DEFF Research Database (Denmark)

Proclemer, Alessandro; Lewalter, Thorsten; Bongiorni, Maria Grazia

2013-01-01

The purpose of this EHRA survey was to examine the current clinical practice of screening and risk evaluation for sudden cardiac death in ischaemic and non-ischaemic cardiomyopathy with a focus on selection of candidates for implantable cardioverter-defibrillator (ICD) therapy, timing of ICD...... implantation, and use of non-invasive and invasive diagnostic tests across Europe. A systematic screening programme for sudden cardiac death existed in 19 out of 31 centres (61.3%). Implantation of ICDs according to the inclusion criteria of MADIT-II and SCD-HeFT trials was reported in 30 and 29% of centres......, respectively, followed by MADIT-CRT (18%), COMPANION (16%), and combined MADIT and MUSTT (7%) indications. In patients with severe renal impairment, ICD implantation for primary prevention of sudden death was always avoided in 8 centres (33.3%), was not used only if creatinine level was >2.5 mg/dL in 10...

Comparison of serum lipid profile in ischaemic and haemorrhagic stroke

International Nuclear Information System (INIS)

Mehmood, A.; Sharif, M.A.

2010-01-01

To compare serum lipid profile between patients of ischaemic and haemorrhagic strokes. Study Design: Cross sectional, comparative study. Place and Duration of Study: Military Hospital, Rawalpindi, from August 2004 to February 2005. Methodology: Patients with diagnosis of stroke comprising 100 consecutive patients each of ischaemic and haemorrhagic strokes were included in the study while patients on lipid lowering therapy were excluded from study. To determine the subtype of stroke, clinical examination followed by CT scan of brain was done. A serum sample after 8 hours of overnight fasting was taken on the next day of admission for both groups of patients. Total serum cholesterol, triglycerides, LDL cholesterol, VLDL-cholesterol and HDL-cholesterol was determined, using enzymatic colorimetric method. Statistical analysis was done by comparison of lipid profile in two subgroups, using proportion test for any significant difference. Results: The mean age at presentation of patients with stroke was 64.2+-12 years with a male to female ratio of 3.6:1. In 100 ischaemic stroke patients, raised serum total cholesterol was seen in 42, triglyceride in 04, LDL-cholesterol in 05 and VLDL-cholesterol in 07 patients. Serum HDL-cholesterol was below the normal reference in 31 cases. On the other hand, serum total cholesterol and triglycerides was raised in 05 patients each, LDL-cholesterol in 09 and VLDL-cholesterol in 03 patients of haemorrhagic stroke. Serum HDL-cholesterol was below normal in 04 patients of haemorrhagic stroke. On comparison, there were significantly greater number of patients with raised serum cholesterol and low HDL-cholesterol in ischaemic stroke than haemorrhagic stroke (p < 0.05). No statistical significance was found on comparing serum values of ischaemic and haemorrhagic stroke for triglycerides, LDL-cholesterol and VLDL-cholesterol. Conclusion: Ischaemic stroke patients had high serum total cholesterol and lower HDL-cholesterol levels as compared to

Medium intensity oral anticoagulants versus aspirin after cerebral ischaemia of arterial origin (ESPRIT) : a randomised controlled trial

NARCIS (Netherlands)

Halkes, P H A; van Gijn, J; Kappelle, L J; Algra, A; Koudstaal, P J

BACKGROUND: Oral anticoagulants are better than aspirin for secondary prevention after myocardial infarction and after cerebral ischaemia in combination with non-rheumatic atrial fibrillation. The European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) aimed to determine

Medium intensity oral anticoagulants versus aspirin after cerebral ischaemia of arterial origin (ESPRIT): a randomised controlled trial

NARCIS (Netherlands)

Halkes, P. H. A.; van Gijn, J.; Kappelle, L. J.; Koudstaal, P. J.; Algra, A.; Banga, J. D.; Boiten, J.; van der Bom, J. G.; Boon, A. E.; Dippel, D. W. J.; Donders, R. C. J. M.; Eefting, F. D.; Franke, C. L.; Frenken, C. W. G. M.; Frijns, C. J. M.; van Gemert, H. M. A.; de Jaegere, P. P. Th; Kamp, O.; Kwa, V. I. H.; de Leeuw, F.-E.; Linn, F. H. H.; van der Meer, W. K.; Mosterd, A.; Pop, G. A. M.; Raaymakers, T. W. M.; van Schooneveld, M. J.; Stam, J.; Verheugt, F. W. A.; van der Worp, H. B.; Zijlstra, F.; Boekweit, M. P.; van Buuren, M.; Greebe, P.; Mooibroek, G. E.; Slabbers, D. C. V.; Beijer, I. S.; van den Bergh, W. M.; Biessels, G. J.; de Schryver, E. L. L. M.; van Dijk, G. W.; Dorhout-Mees, S. M.; Ferrier, C. H.; Gorter, J. W.; Hofmeijer, J.; Hop, J. W.; Klijn, C. J. M.; Manschot, S. M.; Vermeulen, M.; Foncke, E.; Lucas, C.

2007-01-01

BACKGROUND: Oral anticoagulants are better than aspirin for secondary prevention after myocardial infarction and after cerebral ischaemia in combination with non-rheumatic atrial fibrillation. The European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) aimed to determine

Dobutamine stress magnetic resonance imaging suffices for the demonstration of myocardial ischaemia and viability.

Science.gov (United States)

Lamers, F P L; van Dijkman, P R M; Kuijpers, Th J A; van Herpen, G

2003-02-01

We report three patients in whom dobutamine stress magnetic imaging (DS-MRI) was essential in assessing myocardial ischaemia. Two patients were referred to the cardiologist because of chest pain. Patient A had typical exertional angina and a normal resting electrocardiogram (ECG). Patient B had typical exercise-induced angina and had recently experienced an attack of severe chest pain at rest for 15 minutes. The ECG showed a complete left bundle branch block (LBBB). Patient C was referred for heart failure of unknown origin. There were no symptoms of chest pain during rest or exercise. Echocardiography in this patient demonstrated global left ventricular (LV) dilatation, systolic dysfunction and a small dyskinetic segment in the inferior wall. In all these patients exercise stress testing had failed to demonstrate myocardial ischaemia. Patients A and C produced normal findings whereas in patient B the abnormal repolarisation due to pre-existent LBBB precluded a diagnosis of ischaemia. Breath-hold DS-MRI was performed to study LV wall motion and wall thickening at rest through increasing doses of dobutamine. A test was considered positive for myocardial ischaemia if wall motion abnormalities developed at high-dose levels of the drug (20 μg/kg/min or more with a maximum of 40 μg/kg/min) in previously normal vascular territories or worsened in a segment that was normal at baseline. Recovery of wall thickening in a previously hypokinetic or akinetic segment at a low dose of dobutamine (5-10 μg/kg/min) was taken as proof of viability. Patients A and B developed hypokinesia progressing into akinesia at high-dose dobutamine in the anteroseptal area of the LV indicative of ischaemia. These findings were corroborated by coronary angiography demonstrating severe coronary artery disease which led to coronary artery bypass grafting (CABG) in patient A and balloon angioplasty in patient B. In patient C global recovery of LV contractions during low-dose dobutamine was

Self-reported symptoms and risk factors for digital ischaemia among international world-class beach volleyball players

NARCIS (Netherlands)

van de Pol, Daan; Alaeikhanehshir, Sena; Maas, Mario; Kuijer, P. Paul F. M.

2016-01-01

The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and

Mesenteric ischaemia after endovascular coiling of ruptured cerebral aneurysms.

LENUS (Irish Health Repository)

Kamel, M H

2012-02-03

Three patients were referred to a national neurosurgical centre following CT evidence of subarachnoid haemorrhage. The three patients, who were referred from different institutions within a seven week period, were Fisher grade 3 and WFNS Grade I at all times. Angiography showed a PCOM aneurysm in one case, a ruptured Basilar tip aneurysm and an unruptured ACOM aneurysm in another case, and an ACOM aneurysm in the third case. It was decided that the aneurysms were suitable for endovascular coiling. These patients had unremarkable intraoperative catheterizations and coiling but subsequently deteriorated post-operatively due to mesenteric ischaemia. Two patients required colectomy for mesenteric ischaemia, and the third arrested secondary to sepsis from bowel perforation. We discuss the various causes that may explain this association, and we alert the neurosurgical community for this complication which has not been reported before.

Polysensory response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia.

Science.gov (United States)

Huang, M H; Horackova, M; Negoescu, R M; Wolf, S; Armour, J A

1996-09-01

To determine the response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia. Extracellular recordings were made from 54 spontaneously active and 5 normally quiescent dorsal root ganglion neurones (T2-T5) in 22 anaesthetized open-chest dogs under control conditions and during epicardial mechanical or chemical stimulation and myocardial ischaemia. The activity of 78% of spontaneously active and all quiescent neurones with left ventricular sensory fields was modified by left ventricular ischaemia. Forty-six spontaneously active neurones (85%) were polysensory with respect to mechanical and chemical stimuli. The 5 quiescent neurones responded only to chemical stimuli. Spontaneously active neurones associated with left ventricular mechanosensory endings (37 neurones) generated four different activity patterns in response to similar mechanical stimuli (high or low pressure active, high-low pressure active, high-low pressure inactive). A fifth group generated activity which was not related to chamber dynamics. Adenosine, adenosine 5'-triphosphate, substance P and bradykinin modified 72, 61, 65 and 63% of the spontaneously active neurones, respectively. Maximum local mechanical or chemical stimuli enhanced activity to similar degrees, as did ischaemia. Each ischaemia-sensitive neurone displayed unique activity patterns in response to similar mechanical or chemical stimuli. Most myocardial ischemia-sensitive dorsal root ganglion neurones associated with epicardial neurites sense mechanical and multiple chemical stimuli, a small population sensing only mechanical or chemical stimuli. Activity patterns generated by these neurones depend on their primary sensory characteristics or those of other neurones that may converge on them, as well as the type and magnitude of the stimuli that impinge upon their sensory fields, both normally and during ischaemia.

Ischemic Preconditioning of One Forearm Enhances Static and Dynamic Apnea

DEFF Research Database (Denmark)

Kjeld, Thomas; Rasmussen, Mads Reinholdt; Jattu, Timo

2014-01-01

INTRODUCTION: Ischemic preconditioning enhances ergometer cycling and swimming performance. We evaluated whether ischemic preconditioning of one forearm (four times for 5 min) also affects static breath hold and underwater swimming, whereas the effect of similar preconditioning on ergometer rowing...... preconditioning reduced the forearm oxygen saturation from 65% ± 7% to 19% ± 7% (mean ± SD; P right thigh.......05). CONCLUSIONS: We conclude that while the effect of ischemic preconditioning (of one forearm) on ergometer rowing was minimal, probably because of reduced muscle oxygenation during the warm-up, ischemic preconditioning does enhance both static and dynamic apnea, supporting that muscle ischemia is an important...

Heritability of young- and old-onset ischaemic stroke.

Science.gov (United States)

Bluher, A; Devan, W J; Holliday, E G; Nalls, M; Parolo, S; Bione, S; Giese, A K; Boncoraglio, G B; Maguire, J M; Müller-Nurasyid, M; Gieger, C; Meschia, J F; Rosand, J; Rolfs, A; Kittner, S J; Mitchell, B D; O'Connell, J R; Cheng, Y C

2015-11-01

Although the genetic contribution to stroke risk is well known, it remains unclear if young-onset stroke has a stronger genetic contribution than old-onset stroke. This study aims to compare the heritability of ischaemic stroke risk between young and old, using common genetic variants from whole-genome array data in population-based samples. This analysis included 4050 ischaemic stroke cases and 5765 controls from six study populations of European ancestry; 47% of cases were young-onset stroke (age stroke risk in these unrelated individuals, the pairwise genetic relatedness was estimated between individuals based on their whole-genome array data using a mixed linear model. Heritability was estimated separately for young-onset stroke and old-onset stroke (age ≥ 55 years). Heritabilities for young-onset stroke and old-onset stroke were estimated at 42% (±8%, P genetic contribution to the risk of stroke may be higher in young-onset ischaemic stroke, although the difference was not statistically significant. © 2015 EAN.

Abdominal symptoms during physical exercise and the role of gastrointestinal ischaemia : a study in 12 symptomatic athletes

NARCIS (Netherlands)

ter Steege, Rinze W. F.; Geelkerken, Robert H.; Huisman, Ad B.; Kolkman, Jeroen J.

2012-01-01

Background Gastrointestinal (GI) symptoms during exercise may be caused by GI ischaemia. The authors report their experience with the diagnostic protocol and management of athletes with symptomatic exercise-induced GI ischaemia. The value of prolonged exercise tonometry in the diagnostic protocol of

EFFECTIVENESS OF PROSTAGLANDIN E1 IN THE PAIN MANAGEMENT OF PATIENTS WITH CRITICAL LIMB ISCHAEMIA- A PROSPECTIVE OBSERVATIONAL STUDY

Directory of Open Access Journals (Sweden)

John Sajan Kurien

2017-08-01

Full Text Available BACKGROUND Critical Limb Ischaemia (CLI was defined for the first time in 1982 by P. R. F. Bell as a manifestation of peripheral artery disease, which describes patient with typical chronic ischaemic rest pain or ischaemic skin ulcers or gangrene.1 This term of CLI should only be used in patients with chronic ischaemic disease defined as presence of recurring rest pain that persists for more than two weeks requiring regular analgesics and with ulceration or gangrene of the foot or toes. These criteria correspond to stage 3 and 4 of Fontaine’s classification of POVD. Observational studies have shown that one year after diagnosis of CLI, 25% of patients experience a major amputation, 25% had died and only 50% survived without requiring a major amputation, though some have rest pain, ulcer or gangrene persisting. The primary goals in treating CLI are to relieve claudication pain and rest pain, to heal the ulcer, to prevent amputation of limbs, to improve quality of life and to prolong survival. The aim of the study is to study the improvement of claudication pain, rest pain and improvement of the level of amputation in patients with diffuse peripheral arterial disease (CLI after administration of PGE1. MATERIALS AND METHODS From June 2013 to November 2014, a total of 45 patients having advanced CLI (Fontaine’s grade III and IV not suitable for angioplasty and stenting or bypass procedures received different courses of PGE1. 20 patients (44.44% received 6 full courses of PGE1,3 patients (6.66% received 5 courses, 5 patients (11.11% received 4 courses, 4 patients (8.8% received 3 courses, 4 patients (8.8% received 2 courses and 9 patients (20% received one course. PGE1 was administered through intravenous infusion (alprostadil 100mcg over 10 hours a day for 5 days in one month (1course. The reduction in claudication and rest pain, improvement in level of amputation and complications were assessed. RESULTS In all cases, there was reduction in pain

Preconditioned Krylov subspace methods for eigenvalue problems

Energy Technology Data Exchange (ETDEWEB)

Wu, Kesheng; Saad, Y.; Stathopoulos, A. [Univ. of Minnesota, Minneapolis, MN (United States)

1996-12-31

Lanczos algorithm is a commonly used method for finding a few extreme eigenvalues of symmetric matrices. It is effective if the wanted eigenvalues have large relative separations. If separations are small, several alternatives are often used, including the shift-invert Lanczos method, the preconditioned Lanczos method, and Davidson method. The shift-invert Lanczos method requires direct factorization of the matrix, which is often impractical if the matrix is large. In these cases preconditioned schemes are preferred. Many applications require solution of hundreds or thousands of eigenvalues of large sparse matrices, which pose serious challenges for both iterative eigenvalue solver and preconditioner. In this paper we will explore several preconditioned eigenvalue solvers and identify the ones suited for finding large number of eigenvalues. Methods discussed in this paper make up the core of a preconditioned eigenvalue toolkit under construction.

Neurological signs in 23 dogs with suspected rostral cerebellar ischaemic stroke

DEFF Research Database (Denmark)

Thomsen, Barbara Blicher; Garosi, Laurent; Skerritt, Geoff

2016-01-01

Background: In dogs with ischaemic stroke, a very common site of infarction is the cerebellum. The aim of this study was to characterise neurological signs in relation to infarct topography in dogs with suspected cerebellar ischaemic stroke and to report short-term outcome confined to the hospita...

Isoflurane preconditions myocardium against infarction via release of free radicals

NARCIS (Netherlands)

Müllenheim, Jost; Ebel, Dirk; Frässdorf, Jan; Preckel, Benedikt; Thämer, Volker; Schlack, Wolfgang

2002-01-01

BACKGROUND: Isoflurane exerts cardioprotective effects that mimic the ischemic preconditioning phenomenon. Generation of free radicals is implicated in ischemic preconditioning. The authors investigated whether isoflurane-induced preconditioning may involve release of free radicals. METHODS:

Secondary prevention after cerebral ischaemia of presumed arterial origin: is aspirin still the touchstone?

NARCIS (Netherlands)

A. Algra (Ale); P.J. Koudstaal (Peter Jan); J. van Gijn (Jan)

1999-01-01

textabstractPatients who have had a transient ischaemic attack or nondisabling ischaemic stroke of presumed arterial origin have an annual risk of death from all vascular causes, non-fatal stroke, or non-fatal myocardial infarction that ranges between 4% and 11% without treatment. In the

Transcranial Doppler for detection of cerebral ischaemia during carotid endarterectomy

DEFF Research Database (Denmark)

Jørgensen, L G; Schroeder, T V

1992-01-01

We evaluated transcranial Doppler sonography (TCD) for the detection of cerebral ischaemia during carotid endarterectomy in 30 male and 14 female patients with ipsilateral focal cerebro-vascular symptoms. Surgery was performed during halothane-nitrous oxide anaesthesia with moderate hypocapnia...

The concept of anaesthetic-induced cardioprotection: mechanisms of action

NARCIS (Netherlands)

Weber, Nina C.; Schlack, Wolfgang

2005-01-01

The mechanisms by which ischaemia reperfusion injury can be influenced have been the subject of extensive research in the last decades. Early restoration of arterial blood flow and surgical measures to improve the ischaemic tolerance of the tissue are the main therapeutic options currently in

40 CFR 86.532-78 - Vehicle preconditioning.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Vehicle preconditioning. 86.532-78... (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.532-78 Vehicle preconditioning. (a) The vehicle...

Projection preconditioning for Lanczos-type methods

Energy Technology Data Exchange (ETDEWEB)

Bielawski, S.S.; Mulyarchik, S.G.; Popov, A.V. [Belarusian State Univ., Minsk (Belarus)

1996-12-31

We show how auxiliary subspaces and related projectors may be used for preconditioning nonsymmetric system of linear equations. It is shown that preconditioned in such a way (or projected) system is better conditioned than original system (at least if the coefficient matrix of the system to be solved is symmetrizable). Two approaches for solving projected system are outlined. The first one implies straightforward computation of the projected matrix and consequent using some direct or iterative method. The second approach is the projection preconditioning of conjugate gradient-type solver. The latter approach is developed here in context with biconjugate gradient iteration and some related Lanczos-type algorithms. Some possible particular choices of auxiliary subspaces are discussed. It is shown that one of them is equivalent to using colorings. Some results of numerical experiments are reported.

Treatment of severe foot ischaemia by defibrination with ancrod

DEFF Research Database (Denmark)

Tønnesen, K H; Sager, P; Gormsen, J

1978-01-01

factors which could affect the degree of ischaemia. Objective measurements showed a significant rise in ankle and toe systolic blood pressure in the ancrod group lasting for 3 months. There was no rise in distal blood pressure in the control group. In the ancrod treated group the toe and ankle systolic...

Ischaemic stroke in children secondary to post varicella angiopathy.

LENUS (Irish Health Repository)

Hayes, B

2007-01-01

Varicella in childhood is a self-limiting disease, which usually follows a benign course. However, complications, although rare, may have serious consequences. Ischaemic stroke secondary to post varicella angiopathy is a well-described complication and is estimated to account for up to a third of all strokes in infants. We present three previously healthy children who presented to our centre with ischaemic cerebrovascular infarction due to varicella angiopathy. All three children first presented within six weeks after onset of varicella infection and had MRI changes characteristic of ischaemic stroke secondary to post varicella angiopathy. While one child made an excellent recovery being left with only a minor deficit, the remaining two children were left with considerable morbidity severely affecting quality of life. The varicella vaccine has been proven to be well tolerated, safe and effective. We conclude that varicella vaccination should be considered for inclusion in the vaccination schedule to prevent serious complications which while rare may have devastating consequences.

The protective effect of ischemic preconditioning on rat testis

Directory of Open Access Journals (Sweden)

Ciralik Harun

2007-12-01

Full Text Available Abstract Background It has been demonstrated that brief episodes of sublethal ischemia-reperfusion, so-called ischemic preconditioning, provide powerful tissue protection in different tissues such as heart, brain, skeletal muscle, lung, liver, intestine, kidney, retina, and endothelial cells. Although a recent study has claimed that there are no protective effects of ischemic preconditioning in rat testis, the protective effects of ischemic preconditioning on testicular tissue have not been investigated adequately. The present study was thus planned to investigate whether ischemic preconditioning has a protective effect on testicular tissue. Methods Rats were divided into seven groups that each contained seven rats. In group 1 (control group, only unilateral testicular ischemia was performed by creating a testicular torsion by a 720 degree clockwise rotation for 180 min. In group 2, group 3, group 4, group 5, group 6, and group 7, unilateral testicular ischemia was performed for 180 min following different periods of ischemic preconditioning. The ischemic preconditioning periods were as follows: 10 minutes of ischemia with 10 minutes of reperfusion in group 2; 20 minutes of ischemia with 10 minutes of reperfusion in group 3; 30 minutes of ischemia with 10 minutes of reperfusion in group 4; multiple preconditioning periods were used (3 × 10 min early phase transient ischemia with 10 min reperfusion in all episodes in group 5; multiple preconditioning periods were used (5, 10, and 15 min early phase transient ischemia with 10 min reperfusion in all episodes in group 6; and, multiple preconditioning periods were used (10, 20, and 30 min early phase transient ischemia with 10 min reperfusion in all episodes in group 7. After the ischemic protocols were carried out, animals were sacrificed by cervical dislocation and testicular tissue samples were taken for biochemical measurements (protein, malondialdehyde, nitric oxide and histological examination

Coronary artery angioplasty for treatment of peri-operative myocardial ischaemia

NARCIS (Netherlands)

Obal, D.; Kindgen-Milles, D.; Schoebel, F.; Schlack, W.

2005-01-01

Increasing numbers of elderly patients with severe co-existing medical diseases undergo major surgery. With these patients there is also an accompanying risk of age-related cardiovascular complications such as life-threatening myocardial ischaemia. We present a patient who suffered a myocardial

Surgical manipulation compromises leukocyte mobilisation responses and inflammation after experimental cerebral ischaemia in mice

Directory of Open Access Journals (Sweden)

Adam eDenes

2014-01-01

Full Text Available Acute brain injury results in peripheral inflammatory changes, although the impact of these processes on neuronal death and neuroinflammation is currently unclear. To facilitate the translation of experimental studies to clinical benefit, it is vital to characterize the mechanisms by which acute brain injury induces peripheral inflammatory changes, and how these are affected by surgical manipulation in experimental models. Here we show that in mice, even mild surgical manipulation of extracranial tissues induced marked granulocyte mobilisation (300% and systemic induction of cytokines. However, intracranial changes induced by craniotomy, or subsequent induction of focal cerebral ischaemia were required to induce egress of CXCR2-positive granulocytes from the bone marrow. CXCR2 blockade resulted in reduced mobilisation of granulocytes from the bone marrow, caused an unexpected increase in circulating granulocytes, but failed to effect brain injury induced by cerebral ischaemia. We also demonstrate that isoflurane anaesthesia interferes with circulating leukocyte responses, which could contribute to the reported vascular and neuroprotective effects of isoflurane. In addition, no immunosuppression develops in the bone marrow after experimental stroke. Thus, experimental models of cerebral ischaemia are compromised by surgery and anaesthesia in proportion to the severity of surgical stress and overall tissue injury. Understanding the inherent confounding effects of surgical manipulation and development of new models of cerebral ischaemia with minimal surgical intervention could facilitate better understanding of interactions between inflammation and brain injury.

The diagnostic performance of CT-derived fractional flow reserve for evaluation of myocardial ischaemia confirmed by invasive fractional flow reserve: a meta-analysis.

Science.gov (United States)

Li, S; Tang, X; Peng, L; Luo, Y; Dong, R; Liu, J

2015-05-01

To review the literature on the diagnostic accuracy of CT-derived fractional flow reserve (FFRCT) for the evaluation of myocardial ischaemia in patients with suspected or known coronary artery disease, with invasive fractional flow reserve (FFR) as the reference standard. A PubMed, EMBASE, and Cochrane cross-search was performed. The pooled diagnostic accuracy of FFRCT, with FFR as the reference standard, was primarily analysed, and then compared with that of CT angiography (CTA). The thresholds to diagnose ischaemia were FFR ≤0.80 or CTA ≥50% stenosis. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Three multicentre studies (NXT Trial, DISCOVER-FLOW study and DeFACTO study) were included, examining 609 patients and 1050 vessels. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) for FFRCT were 89% (85-93%), 71% (65-75%), 70% (65-75%), 90% (85-93%), 3.31 (1.79-6.14), 0.16 (0.11-0.23), and 21.21 (9.15-49.15) at the patient-level, and 83% (78-63%), 78% (75-81%), 61% (56-65%), 92% (89-90%), 4.02 (1.84-8.80), 0.22 (0.13-0.35), and 19.15 (5.73-63.93) at the vessel-level. At per-patient analysis, FFRCT has similar sensitivity but improved specificity, PPV, NPV, LR+, LR-, and DOR versus those of CTA. At per-vessel analysis, FFRCT had a slightly lower sensitivity, similar NPV, but improved specificity, PPV, LR+, LR-, and DOR compared with those of CTA. The area under the summary receiver operating characteristic curves for FFRCT was 0.8909 at patient-level and 0.8865 at vessel-level, versus 0.7402 for CTA at patient-level. FFRCT, which was associated with improved diagnostic accuracy versus CTA, is a viable alternative to FFR for detecting coronary ischaemic lesions. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Endothelin-1 and endothelin-3 regulate endothelin receptor expression in rat coronary arteries

DEFF Research Database (Denmark)

Skovsted, Gry Freja; Kilic, Semsi; Edvinsson, Lars

2015-01-01

In ischaemic hearts, endothelin (ET) levels are increased, and vasoconstrictor responses to ET-1 are greatly enhanced. We previously reported that ETB receptors are up-regulated in the smooth muscle layer of coronary arteries after myocardial ischaemia-reperfusion and that the MEK-ERK1/2 signalli...

Complications impaired endothelial progenitor cell function in Type 2 diabetic patients with or without critical leg ischaemia: implication for impaired neovascularization in diabetes.

Science.gov (United States)

Chen, M-C; Sheu, J-J; Wang, P-W; Chen, C-Y; Kuo, M-C; Hsieh, C-J; Chen, J-F; Chang, H-W

2009-02-01

This study tested the hypothesis that migratory function of endothelial progenitor cells (EPCs) is impaired in Type 2 diabetic patients with or without critical leg ischaemia. Seventy-four patients were classified into four groups: Type 2 diabetic (n = 21) and non-diabetic patients (n = 10) with critical leg ischaemia and Type 2 diabetic patients without lower extremity vascular disease (n = 30) and healthy subjects (n = 13). The number and functional activity of circulating and cultured EPCs were determined. The migratory function of cultured EPCs was significantly impaired in diabetic patients without (median, 48, interquartile range, 46, 49 count/view/well) and with (median, 51, interquartile range, 46, 60 count/view/well) critical leg ischaemia and non-diabetic patients with critical leg ischaemia (median, 49, interquartile range, 47, 55 count/view/well) compared with healthy subjects (median, 63, interquartile range, 57, 65 count/view/well) (P interquartile range, 1600, 6600/10(6) cytometric events) than Type 2 diabetic patients with critical leg ischaemia (median, 5300, interquartile range, 2400, 11,100/10(6) cytometric events), non-diabetic patients with critical leg ischaemia (median, 5550, interquartile range, 2000, 32,100/10(6) cytometric events) and healthy subjects (median, 5400, interquartile range, 2700, 8700/10(6) cytometric events) (P = 0.413). The migratory function of EPCs is impaired in patients with Type 2 diabetes, even in those without critical leg ischaemia. These findings present an important new insight into the pathogenesis of impaired neovascularization and critical limb ischaemia in diabetic patients and provide avenues of future clinical study.

Xenon preconditioning: molecular mechanisms and biological effects

Directory of Open Access Journals (Sweden)

Liu Wenwu

2013-01-01

Full Text Available Abstract Xenon is one of noble gases and has been recognized as an anesthetic for more than 50 years. Xenon possesses many of the characteristics of an ideal anesthetic, but it is not widely applied in clinical practice mainly because of its high cost. In recent years, numerous studies have demonstrated that xenon as an anesthetic can exert neuroprotective and cardioprotective effects in different models. Moreover, xenon has been applied in the preconditioning, and the neuroprotective and cardioprotective effects of xenon preconditioning have been investigated in a lot of studies in which some mechanisms related to these protections are proposed. In this review, we summarized these mechanisms and the biological effects of xenon preconditioning.

Chronic Cerebral Ischaemia Forms New Cholinergic Mechanisms of Learning and Memory

Directory of Open Access Journals (Sweden)

E. I. Zakharova

2010-01-01

Full Text Available The purpose of this research was a comparative analysis of cholinergic synaptic organization following learning and memory in normal and chronic cerebral ischaemic rats in the Morris water maze model. Choline acetyltransferase and protein content were determined in subpopulations of presynapses of “light” and “heavy” synaptosomal fractions of the cortex and the hippocampus, and the cholinergic projective and intrinsic systems of the brain structures were taken into consideration. We found a strong involvement of cholinergic systems, both projective and intrinsic, in all forms of cognition. Each form of cognition had an individual cholinergic molecular profile and the cholinergic synaptic compositions in the ischaemic rat brains differed significantly from normal ones. Our data demonstrated that under ischaemic conditions, instead of damaged connections new key synaptic relationships, which were stable against pathological influences and able to restore damaged cognitive functions, arose. The plasticity of neurochemical links in the individual organization of certain types of cognition gave a new input into brain pathology and can be used in the future for alternative corrections of vascular and other degenerative dementias.

Helium induces preconditioning in human endothelium in vivo

NARCIS (Netherlands)

Smit, Kirsten F.; Oei, Gezina T. M. L.; Brevoord, Daniel; Stroes, Erik S.; Nieuwland, Rienk; Schlack, Wolfgang S.; Hollmann, Markus W.; Weber, Nina C.; Preckel, Benedikt

2013-01-01

Helium protects myocardium by inducing preconditioning in animals. We investigated whether human endothelium is preconditioned by helium inhalation in vivo. Forearm ischemia-reperfusion (I/R) in healthy volunteers (each group n = 10) was performed by inflating a blood pressure cuff for 20 min.

Neurorehabilitation after Stroke

Directory of Open Access Journals (Sweden)

Rüdiger J. Seitz

2013-08-01

Full Text Available Recovery from ischaemic stroke is determined in the acute phase by the lesion impact of ischaemia and subsequently, by functional and structural network changes in the spared brain tissue. Neurorehabilitation supports the restitution of function using repetitive, learning-based and, more recently, technology-based training strategies.

Ischemic preconditioning protects against gap junctional uncoupling in cardiac myofibroblasts.

Science.gov (United States)

Sundset, Rune; Cooper, Marie; Mikalsen, Svein-Ole; Ytrehus, Kirsti

2004-01-01

Ischemic preconditioning increases the heart's tolerance to a subsequent longer ischemic period. The purpose of this study was to investigate the role of gap junction communication in simulated preconditioning in cultured neonatal rat cardiac myofibroblasts. Gap junctional intercellular communication was assessed by Lucifer yellow dye transfer. Preconditioning preserved intercellular coupling after prolonged ischemia. An initial reduction in coupling in response to the preconditioning stimulus was also observed. This may protect neighboring cells from damaging substances produced during subsequent regional ischemia in vivo, and may preserve gap junctional communication required for enhanced functional recovery during subsequent reperfusion.

Survival and clinical outcome of dogs with ischaemic stroke.

Science.gov (United States)

Gredal, H; Toft, N; Westrup, U; Motta, L; Gideon, P; Arlien-Søborg, P; Skerritt, G C; Berendt, M

2013-06-01

The objectives of the present study were to investigate survival time, possible predictors of survival and clinical outcome in dogs with ischaemic stroke. A retrospective study of dogs with a previous diagnosis of ischaemic stroke diagnosed by magnetic resonance imaging (MRI) was performed. The association between survival and the hypothesised risk factors was examined using univariable exact logistic regression. Survival was examined using Kaplan-Meier and Cox regression. Twenty-two dogs were identified. Five dogs (23%) died within the first 30days of the stroke event. Median survival in 30-day survivors was 505days. Four dogs (18%) were still alive by the end of the study. Right-sided lesions posed a significantly increased risk of mortality with a median survival time in dogs with right-sided lesions of 24days vs. 602days in dogs with left sided lesions (P=0.006). Clinical outcome was considered excellent in seven of 17 (41%) 30-day survivors. Another seven 30-day survivors experienced new acute neurological signs within 6-17months of the initial stroke event; in two of those cases a new ischaemic stroke was confirmed by MRI. In conclusion, dogs with ischaemic stroke have a fair to good prognosis in terms of survival and clinical outcome. However, owners should be informed of the risk of acute death within 30days and of the possibility of new neurological events in survivors. Mortality was increased in dogs with right-sided lesions in this study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Atrial fibrillation, ischaemic heart disease, and the risk of death in patients with heart failure

DEFF Research Database (Denmark)

Pedersen, Ole Dyg; Søndergaard, Peter; Nielsen, Tonny

2006-01-01

AIMS: Atrial fibrillation (AF) is a risk factor for death in patients with a myocardial infarction, but highly variable results are reported in patients with heart failure. We studied the prognostic impact of AF in heart failure patients with and without ischaemic heart disease. METHODS AND RESULTS......), 1.02-1.23, P=0.018]. There was a significant interaction between the importance of AF and the presence of ischaemic heart disease (P=0.034). In patients with AF at the time of discharge and ischaemic heart disease, HR was 1.25 (95% CI: 1.09-1.42) and P... and without ischaemic heart disease, HR was 1.01 (95% CI: 0.88-1.16) and P=0.88. CONCLUSION: AF is associated with increased risk of death only in patients with ischaemic heart disease. This finding may explain the variable results of studies of the prognosis associated with AF in heart failure....

Kronecker Products on Preconditioning

KAUST Repository

Gao, Longfei

2013-01-01

techniques have become increasingly popular due to their great potential on large scale computation. In this work, we present preconditioning techniques for linear systems built with tensor product basis functions. Efficient algorithms are designed

More than meets the eye: infant presenting with hypoxic ischaemic encephalopathy.

Science.gov (United States)

Sen, Kuntal; Agarwal, Rajkumar

2018-04-05

We report a newborn infant who presented with poor Apgar scores and umbilical artery acidosis leading to the diagnosis of hypoxic ischaemic encephalopathy. During the course of the infant's hospitalisation, subsequent workup revealed an underlying genetic cause that masqueraded as hypoxic ischaemic encephalopathy. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Tourniquet-induced ischaemia-reperfusion injury: the comparison of antioxidative effects of small-dose propofol and ketamine

Directory of Open Access Journals (Sweden)

Karaca Omer

Full Text Available Abstract Objectives: The aim of the present study was to investigate the preventive effects of propofol and ketamine as small dose sedation during spinal anaesthesia on tourniquet-induced ischaemia-reperfusion injury. Methods: 30 patients were randomly assigned into two groups of 15 patients. In the propofol group, sedation was performed with propofol 0.2 mg·kg-1 followed by infusion at a rate of 2 mg·kg-1·h-1. In the ketamine group, a continuous infusion of ketamine 0.5 mg·kg-1·h-1 was used until the end of surgery. Intravenous administration of midazolam was not used in any patients. Ramsay sedation scale was used for assessing the sedation level. Venous blood samples were obtained before propofol and ketamine infusion (T1, at 30 minutes (min of tourniquet ischaemia (T2, and 5 min after tourniquet deflation (T3 for malondialdehyde (MDA measurements. Results: No differences were noted between the groups in haemodynamic (p > 0.05 and demographic data (p > 0.05. There was no statistically significant difference between the two groups in terms of T1, T2 and T3 periods (p > 0.05. There was a statistically increase observed in MDA values respectively both in Group P and Group K between the reperfusion period (1.95 ± 0.59, 2.31 ± 0.48 and pre-ischaemia (1.41 ± 0.38, 1.54 ± 0.45, and ischaemia (1.76 ± 0.70, 1.71 ± 0.38 (µmoL-1 periods (p < 0.05. Conclusions: Small-dose propofol and ketamine has similar potential to reduce the oxidative stress caused by tourniquet-induced ischaemia-reperfusion injury in patients undergoing arthroscopic knee surgery under spinal anaesthesia.

Association of plasma uric acid with ischaemic heart disease and blood pressure

DEFF Research Database (Denmark)

Palmer, Tom M; Nordestgaard, Børge G; Benn, Marianne

2013-01-01

To assess the associations between both uric acid levels and hyperuricaemia, with ischaemic heart disease and blood pressure, and to explore the potentially confounding role of body mass index.......To assess the associations between both uric acid levels and hyperuricaemia, with ischaemic heart disease and blood pressure, and to explore the potentially confounding role of body mass index....

Frequency of hyper-homocysteinaemia in ischaemic stroke patients of Karachi

International Nuclear Information System (INIS)

Sadiq, M.

2014-01-01

Objective: To find out the frequency of hyper-homocysteinaemia in ischaemic stroke patients and its relation with other risk factors. Methods: The cross-sectional study based on convenience sampling was conducted at the Civil Hospital, Karachi, from May to July 2012. It comprised ischaemic stroke patients selected from the Out Patient Department and Emergency Department. An overnight 8-hour fasting venous blood sample (4 ml in ethylenediamminetetraacetate) was drawn for analysis. Rest of the data was collected through a structured proforma and was analysed using SPSS 17.0. Results: The mean age of the 96 patients in the study was 64.9+-10.9 years (range: 40-85).Overall, 56(58.3%) cases had hyper-homocysteinemia. The frequency was significantly high in the age 60-79 age group (p<0.007). Conclusion: Hyper-homocysteinaemia, a modifiable risk factor, is associated with a high number of ischaemic stroke patients. Hence, steps should be taken to minimise this risk factor by screening and early intervention. (author)

Matrix preconditioning: a robust operation for optical linear algebra processors.

Science.gov (United States)

Ghosh, A; Paparao, P

1987-07-15

Analog electrooptical processors are best suited for applications demanding high computational throughput with tolerance for inaccuracies. Matrix preconditioning is one such application. Matrix preconditioning is a preprocessing step for reducing the condition number of a matrix and is used extensively with gradient algorithms for increasing the rate of convergence and improving the accuracy of the solution. In this paper, we describe a simple parallel algorithm for matrix preconditioning, which can be implemented efficiently on a pipelined optical linear algebra processor. From the results of our numerical experiments we show that the efficacy of the preconditioning algorithm is affected very little by the errors of the optical system.

Preconditioned iterative methods for space-time fractional advection-diffusion equations

Science.gov (United States)

Zhao, Zhi; Jin, Xiao-Qing; Lin, Matthew M.

2016-08-01

In this paper, we propose practical numerical methods for solving a class of initial-boundary value problems of space-time fractional advection-diffusion equations. First, we propose an implicit method based on two-sided Grünwald formulae and discuss its stability and consistency. Then, we develop the preconditioned generalized minimal residual (preconditioned GMRES) method and preconditioned conjugate gradient normal residual (preconditioned CGNR) method with easily constructed preconditioners. Importantly, because resulting systems are Toeplitz-like, fast Fourier transform can be applied to significantly reduce the computational cost. We perform numerical experiments to demonstrate the efficiency of our preconditioners, even in cases with variable coefficients.

Effect of hypothermic renal ischaemia on renin secretion rate in man

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl; Petersen, H K; Giese, J

1985-01-01

Plasma renin concentration (PRC), renal blood flow (RBF) and renin secretion rate (RSR = renal veno-arterial PRC difference multiplied by renal plasma flow) were measured before and after a period of hypothermic renal ischaemia in seven patients undergoing surgery for renal calculi. After...

Atrophy of the corpus callosum correlates with white matter lesions in patients with cerebral ischaemia

International Nuclear Information System (INIS)

Meguro, K.; Yamadori, A.; Constans, J.M.; Courtheoux, P.; Theron, J.; Viader, F.

2000-01-01

Many studies of white matter high signal (WMHS) on T2-weighted MRI have disclosed that it is related to cerebral ischaemia and to brain atrophy. Atrophy of the corpus callosum (CC) has also been studied in relation to ischaemia. Our objective was to test the hypothesis that CC atrophy could be due to ischaemia. We therefore assessed CC, WMHS and brain atrophy in patients with risk factors without strokes (the risk factor group) and in those with infarcts (the infarct group), to investigate the relationships between these factors. We studied 30 patients in the infarct group, 14 in the risk factor group, and 29 normal subjects. Using axial T1-weighted MRI, cortical atrophy and ventricular enlargement (brain atrophy) were visually rated. Using axial T2-weighted MRI, WMHS was assessed in three categories: periventricular symmetrical, periventricular asymmetrical and subcortical. Using the mid-sagittal T1-weighted image, the CC was measured in its anterior, posterior, midanterior and midposterior portions. In the normal group, no correlations were noted between parameters. In the infarct group, there were significant correlations between CC and brain atrophy, and between CC atrophy and WMHS. After removing the effects of age, gender and brain atrophy, significant correlations were noted between some CC measures and subcortical WMHS. In the risk factor group, there were significant correlations between CC and brain atrophy and between CC atrophy and WMHS. After allowance for age, gender and brain atrophy, significant correlations between some CC measures and periventricular WMHS remained. The hypothesis that CC atrophy could be due to cerebral ischaemia was supported by other analyses. Namely, for correlations between the extent of infarcts and partial CC atrophy in patients with anterior middle cerebral artery (MCA) and with posterior MCA infarcts, there were significant correlations between the extent of infarct and midanterior CC atrophy in the former, and posterior

Atrophy of the corpus callosum correlates with white matter lesions in patients with cerebral ischaemia

Energy Technology Data Exchange (ETDEWEB)

Meguro, K.; Yamadori, A. [Section of Neuropsychology, Division of Disability Science, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, 980-8575 Sendai (Japan); Constans, J.M.; Courtheoux, P.; Theron, J. [MR Unit, University of Caen School of Medicine, Caen (France); Viader, F. [Department of Neuroradiology, University of Caen School of Medicine, Caen (France)

2000-06-01

Many studies of white matter high signal (WMHS) on T2-weighted MRI have disclosed that it is related to cerebral ischaemia and to brain atrophy. Atrophy of the corpus callosum (CC) has also been studied in relation to ischaemia. Our objective was to test the hypothesis that CC atrophy could be due to ischaemia. We therefore assessed CC, WMHS and brain atrophy in patients with risk factors without strokes (the risk factor group) and in those with infarcts (the infarct group), to investigate the relationships between these factors. We studied 30 patients in the infarct group, 14 in the risk factor group, and 29 normal subjects. Using axial T1-weighted MRI, cortical atrophy and ventricular enlargement (brain atrophy) were visually rated. Using axial T2-weighted MRI, WMHS was assessed in three categories: periventricular symmetrical, periventricular asymmetrical and subcortical. Using the mid-sagittal T1-weighted image, the CC was measured in its anterior, posterior, midanterior and midposterior portions. In the normal group, no correlations were noted between parameters. In the infarct group, there were significant correlations between CC and brain atrophy, and between CC atrophy and WMHS. After removing the effects of age, gender and brain atrophy, significant correlations were noted between some CC measures and subcortical WMHS. In the risk factor group, there were significant correlations between CC and brain atrophy and between CC atrophy and WMHS. After allowance for age, gender and brain atrophy, significant correlations between some CC measures and periventricular WMHS remained. The hypothesis that CC atrophy could be due to cerebral ischaemia was supported by other analyses. Namely, for correlations between the extent of infarcts and partial CC atrophy in patients with anterior middle cerebral artery (MCA) and with posterior MCA infarcts, there were significant correlations between the extent of infarct and midanterior CC atrophy in the former, and posterior

Dobutamine stress echocardiography related sustained ventricular tachycardia in a patient with ischaemic cardiomyopathy

Directory of Open Access Journals (Sweden)

Amrit S Lota

2014-01-01

Full Text Available A 66 year-old Asian man; with a complex history of ischaemic heart disease presented with cardiac and troponin negative chest pain. His ECG showed sinus bradycardia with old left bundle branch block. The transthoracic echocardiography showed severely impaired left ventricular systolic function (EF 30-35%. The patient had had coronary artery bypass grafting at age of 42 years and remained asymptomatic until age of 56 years when he presented with incessant ventricular tachycardia requiring amiodarone, lidocaine and electrical cardioversion. Coronary angiography at that time showed occluded vein grafts to the circumflex and diagonal arteries. The right coronary artery (RCA was small and received collaterals from the left system. A myocardial perfusion scan showed extensive inferolateral infarction but no evidence for reversible ischaemia. An implantable cardiac defibrillator (ICD was thus inserted. Over the following years, the patient underwent multiple PCI procedures with rotational atherectomy to the native LAD and associated vein graft, but subsequently developed in-stent restenosis. He also had PCI to the native RCA. He declined a minimally invasive grafting of the left internal mammary artery (LIMA to the LAD and re-implantation of a new ICD after ex-plantation of the original one due to sepsis. His coronary artery disease remained stable following a recent admission with Troponin positive event which was confirmed by a repeat angiogram, therefore, had up-titrated anti-anginal medications. A low dose beta-blockade was discontinued due to documented sinus pauses up to 3 seconds. Following the recent admission, a joint cardiology-cardiothoracic meeting discussion recommended a stress echocardiogram with highdose dobutamine to guide towards considering re-do bypass grafting.

Theophylline as an add-on to thrombolytic therapy in acute ischaemic stroke (TEA-Stroke)

DEFF Research Database (Denmark)

Modrau, Boris; Hjort, Niels; Østergaard, Leif

2016-01-01

the collateral supply in acute ischaemic brain tissue and thus facilitate reperfusion despite proximal vessel occlusion. The primary study objective is to evaluate whether theophylline is safe and efficient in acute ischaemic stroke patients as an add-on to thrombolytic therapy.MethodsThe TEA-Stroke Trial...... models, clinical case series and randomized clinical trials are controversial. A Cochrane analysis from 2004 concluded that there was not enough evidence to assess whether theophylline is safe and improves outcomes in patients with acute ischaemic stroke. The TEA-Stroke Trial will clarify whether...

Genetic risk factors for ischaemic stroke and its subtypes (the METASTROKE collaboration)

DEFF Research Database (Denmark)

Traylor, Matthew; Farrall, Martin; Holliday, Elizabeth G

2012-01-01

Various genome-wide association studies (GWAS) have been done in ischaemic stroke, identifying a few loci associated with the disease, but sample sizes have been 3500 cases or less. We established the METASTROKE collaboration with the aim of validating associations from previous GWAS...... and identifying novel genetic associations through meta-analysis of GWAS datasets for ischaemic stroke and its subtypes....

ELECTROCARDIOGRAPHIC CHANGES OBSERVED IN HAEMORRHAGIC AND ISCHAEMIC CEREBROVASCULAR DISEASES

Directory of Open Access Journals (Sweden)

Channappa

2016-03-01

Full Text Available INTRODUCTION Cardiac abnormalities are relatively common after acute neurologic injury. Disturbances can vary in severity from transient ECG abnormalities to profound myocardial injury and dysfunction. CNS is involved in the generation of cardiac arrhythmias and dysfunction even in an otherwise normal myocardium. AIM To find out proportion of ECG changes observed in ischaemic and haemorrhagic stroke. MATERIALS AND METHODS The Electrocardiographs of 100 patients with acute stroke were studied to find out the types of ECG abnormalities among different types of stroke. RESULTS In our study, the most common ECG abnormalities associated with stroke were prolonged QTc interval, ST-T segment abnormalities, prominent U wave and arrhythmias. Trop-I was positive in 12.8% patients with ECG changes. Statistical significance was found in association with Trop-I positivity and ST depression. CONCLUSION Usually patients with heart disease present with arrhythmias and Ischaemic like ECG changes. But these changes are also seen most often in the patients with presenting with stroke who didn’t have any past history of heart disease. This shows that arrhythmias and ischaemic ECG abnormalities are primarily evolved due to central nervous system disorders.

Gastric mucosal electrical potential difference, pH, blood flow, and morphology during hypoxia and selective gastric ischaemia with and without allopurinol pretreatment in anaesthetized dogs

DEFF Research Database (Denmark)

Højgaard, L; Bülow, J B; Madsen, J

1990-01-01

Ischaemia has been implicated in the pathogenesis of gastric mucosal disorders. The aim of this investigation was to study the gastric mucosal electrical potential difference (PD), pH, blood flow and morphology during hypoxia, gastric ischaemia, and gastric ischaemia following inhibition of free...... radical formation with allopurinol. PD and pH were measured simultaneously with an intragastric microelectrode, and the PD values were corrected for the liquid junction potentials created by the intragastric pH variation. Blood flow was measured by the radiolabelled microsphere technique in 18...... anaesthetized dogs. Short general hypoxia and short ischaemia caused reversible declines in PD, increases in pH, and no morphological damage. Ischaemia for 1 h caused a significant decline in PD persistent after reperfusion, an increase in pH, and morphological PD, but after reperfusion PD was normalized. Gross...

Operator-Based Preconditioning of Stiff Hyperbolic Systems

International Nuclear Information System (INIS)

Reynolds, Daniel R.; Samtaney, Ravi; Woodward, Carol S.

2009-01-01

We introduce an operator-based scheme for preconditioning stiff components encountered in implicit methods for hyperbolic systems of partial differential equations posed on regular grids. The method is based on a directional splitting of the implicit operator, followed by a characteristic decomposition of the resulting directional parts. This approach allows for solution to any number of characteristic components, from the entire system to only the fastest, stiffness-inducing waves. We apply the preconditioning method to stiff hyperbolic systems arising in magnetohydro- dynamics and gas dynamics. We then present numerical results showing that this preconditioning scheme works well on problems where the underlying stiffness results from the interaction of fast transient waves with slowly-evolving dynamics, scales well to large problem sizes and numbers of processors, and allows for additional customization based on the specific problems under study

Minimal residual method stronger than polynomial preconditioning

Energy Technology Data Exchange (ETDEWEB)

Faber, V.; Joubert, W.; Knill, E. [Los Alamos National Lab., NM (United States)] [and others

1994-12-31

Two popular methods for solving symmetric and nonsymmetric systems of equations are the minimal residual method, implemented by algorithms such as GMRES, and polynomial preconditioning methods. In this study results are given on the convergence rates of these methods for various classes of matrices. It is shown that for some matrices, such as normal matrices, the convergence rates for GMRES and for the optimal polynomial preconditioning are the same, and for other matrices such as the upper triangular Toeplitz matrices, it is at least assured that if one method converges then the other must converge. On the other hand, it is shown that matrices exist for which restarted GMRES always converges but any polynomial preconditioning of corresponding degree makes no progress toward the solution for some initial error. The implications of these results for these and other iterative methods are discussed.

Quantification of structural changes in the corpus callosumin children with profound hypoxic-ischaemic brain injury

Energy Technology Data Exchange (ETDEWEB)

Stivaros, Stavros M. [Manchester Academic Health Science Centre, Academic Unit of Paediatric Radiology, Royal Manchester Children' s Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester (United Kingdom); University of Manchester, Centre for Imaging Sciences, Institute of Population Health, Manchester (United Kingdom); Radon, Mark R. [The Walton Centre NHS Foundation Trust, Department of Neuroradiology, Liverpool (United Kingdom); Mileva, Reneta; Gledson, Ann; Keane, John A. [University of Manchester, School of Computer Science, Manchester (United Kingdom); Connolly, Daniel J.A.; Batty, Ruth [Sheffield Children' s Hospital NHS Foundation Trust, Department of Neuroradiology, Sheffield (United Kingdom); Cowell, Patricia E. [University of Sheffield, Department of Human Communication Sciences, Sheffield (United Kingdom); Hoggard, Nigel; Griffiths, Paul D. [University of Sheffield, Academic Unit of Radiology, Sheffield (United Kingdom); Wright, Neville B.; Tang, Vivian [Manchester Academic Health Science Centre, Academic Unit of Paediatric Radiology, Royal Manchester Children' s Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester (United Kingdom)

2016-01-15

Birth-related acute profound hypoxic-ischaemic brain injury has specific patterns of damage including the paracentral lobules. To test the hypothesis that there is anatomically coherent regional volume loss of the corpus callosum as a result of this hemispheric abnormality. Study subjects included 13 children with proven acute profound hypoxic-ischaemic brain injury and 13 children with developmental delay but no brain abnormalities. A computerised system divided the corpus callosum into 100 segments, measuring each width. Principal component analysis grouped the widths into contiguous anatomical regions. We conducted analysis of variance of corpus callosum widths as well as support vector machine stratification into patient groups. There was statistically significant narrowing of the mid-posterior body and genu of the corpus callosum in children with hypoxic-ischaemic brain injury. Support vector machine analysis yielded over 95% accuracy in patient group stratification using the corpus callosum centile widths. Focal volume loss is seen in the corpus callosum of children with hypoxic-ischaemic brain injury secondary to loss of commissural fibres arising in the paracentral lobules. Support vector machine stratification into the hypoxic-ischaemic brain injury group or the control group on the basis of corpus callosum width is highly accurate and points towards rapid clinical translation of this technique as a potential biomarker of hypoxic-ischaemic brain injury. (orig.)

Quantification of structural changes in the corpus callosumin children with profound hypoxic-ischaemic brain injury

International Nuclear Information System (INIS)

Stivaros, Stavros M.; Radon, Mark R.; Mileva, Reneta; Gledson, Ann; Keane, John A.; Connolly, Daniel J.A.; Batty, Ruth; Cowell, Patricia E.; Hoggard, Nigel; Griffiths, Paul D.; Wright, Neville B.; Tang, Vivian

2016-01-01

Birth-related acute profound hypoxic-ischaemic brain injury has specific patterns of damage including the paracentral lobules. To test the hypothesis that there is anatomically coherent regional volume loss of the corpus callosum as a result of this hemispheric abnormality. Study subjects included 13 children with proven acute profound hypoxic-ischaemic brain injury and 13 children with developmental delay but no brain abnormalities. A computerised system divided the corpus callosum into 100 segments, measuring each width. Principal component analysis grouped the widths into contiguous anatomical regions. We conducted analysis of variance of corpus callosum widths as well as support vector machine stratification into patient groups. There was statistically significant narrowing of the mid-posterior body and genu of the corpus callosum in children with hypoxic-ischaemic brain injury. Support vector machine analysis yielded over 95% accuracy in patient group stratification using the corpus callosum centile widths. Focal volume loss is seen in the corpus callosum of children with hypoxic-ischaemic brain injury secondary to loss of commissural fibres arising in the paracentral lobules. Support vector machine stratification into the hypoxic-ischaemic brain injury group or the control group on the basis of corpus callosum width is highly accurate and points towards rapid clinical translation of this technique as a potential biomarker of hypoxic-ischaemic brain injury. (orig.)

Mobilisation of satellite cells following ischaemia and reperfusion in ...

African Journals Online (AJOL)

Objective. To describe the morphological and morphometric features of activated skeletal muscle satellite cells in primates, using an ischaemic reperfusion model. Setting. The study was undertaken at the Biomedical Resource Centre and the Electron Microscopy Unit of the University of KwaZulu-Natal. Interventions.

MR imaging of term infants with hypoxic-ischaemic encephalopathy as a predictor of neurodevelopmental outcome and late MRI appearances

International Nuclear Information System (INIS)

Twomey, Eilish; Ryan, Stephanie; Twomey, Anne; Murphy, John; Donoghue, Veronica B.

2010-01-01

Morbidity attributable to hypoxic-ischaemic injury (HIE) in the perinatal period remains problematic, and timely and accurate assessment of the degree of injury is required for clinical management and prognosis. Conventional MR sequences typically appear normal in the first 48 h post HIE. While diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps register the injury earlier, perhaps within the first 24 h, it has been suggested that there may be a propensity at that early stage to underestimate the lesion severity or extent. To assess whether MR imaging that included DWI, measured ADC values and T1- and T2-weighted sequences ultimately correlated with either neurodevelopmental outcome or with late MR imaging at 2 years of age. In addition, we wished to compare the performance of MR imaging with cranial US imaging. All infants presenting with HIE who had an MRI within 10 days of life were eligible for enrollment and subsequently underwent a full neurodevelopmental assessment at 2 years of age. All children underwent repeat MRI at this time. All neonates had at least one cranial US study. The US findings were categorized as normal, abnormalities confined to the cerebral cortex and subcortical white matter, isolated central grey matter hyperechogenicity, and central hyperechogenicity combined with cerebral cortical/subcortical changes. All MRI studies were retrospectively reviewed by three radiologists. The patterns of injury on the early DWI and ADC maps and early T1- and T2-W studies were recorded as diffuse, central, watershed or atypical. The patterns of signal abnormality were assessed using a scoring system that yielded four separate scores [basal ganglia (BG), watershed (W), BG/W and summation (S)] for the three sets of images, a total of 12 scores in all. The appearance of the posterior limb of the internal capsule (PLIC) on T1-W inversion recovery sequences and of the corpus callosum on all sequences was also documented. After

MR imaging of term infants with hypoxic-ischaemic encephalopathy as a predictor of neurodevelopmental outcome and late MRI appearances

Energy Technology Data Exchange (ETDEWEB)

Twomey, Eilish; Ryan, Stephanie [Children' s University Hospital, Department of Radiology, Dublin (Ireland); Twomey, Anne; Murphy, John [National Maternity Hospital, Department of Neonatology, Dublin (Ireland); Donoghue, Veronica B. [National Maternity Hospital, Department of Radiology, Dublin (Ireland); Children' s University Hospital, Department of Radiology, Dublin (Ireland)

2010-09-15

Morbidity attributable to hypoxic-ischaemic injury (HIE) in the perinatal period remains problematic, and timely and accurate assessment of the degree of injury is required for clinical management and prognosis. Conventional MR sequences typically appear normal in the first 48 h post HIE. While diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps register the injury earlier, perhaps within the first 24 h, it has been suggested that there may be a propensity at that early stage to underestimate the lesion severity or extent. To assess whether MR imaging that included DWI, measured ADC values and T1- and T2-weighted sequences ultimately correlated with either neurodevelopmental outcome or with late MR imaging at 2 years of age. In addition, we wished to compare the performance of MR imaging with cranial US imaging. All infants presenting with HIE who had an MRI within 10 days of life were eligible for enrollment and subsequently underwent a full neurodevelopmental assessment at 2 years of age. All children underwent repeat MRI at this time. All neonates had at least one cranial US study. The US findings were categorized as normal, abnormalities confined to the cerebral cortex and subcortical white matter, isolated central grey matter hyperechogenicity, and central hyperechogenicity combined with cerebral cortical/subcortical changes. All MRI studies were retrospectively reviewed by three radiologists. The patterns of injury on the early DWI and ADC maps and early T1- and T2-W studies were recorded as diffuse, central, watershed or atypical. The patterns of signal abnormality were assessed using a scoring system that yielded four separate scores [basal ganglia (BG), watershed (W), BG/W and summation (S)] for the three sets of images, a total of 12 scores in all. The appearance of the posterior limb of the internal capsule (PLIC) on T1-W inversion recovery sequences and of the corpus callosum on all sequences was also documented. After

Self-reported symptoms and risk factors for digital ischaemia among international world-class beach volleyball players.

Science.gov (United States)

Van De Pol, Daan; Alaeikhanehshir, Sena; Maas, Mario; Kuijer, P Paul F M

2016-01-01

The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30-15.07) and sex (female) (OR 4.62, 90% CI 1.15-18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.

Bilateral Non-arteritic Anterior Ischaemic Optic Neuropathy as the Presentation of Systemic Amyloidosis.

Science.gov (United States)

Kanaan, M Z; Lorenzi, A R; Thampy, N; Pandit, R; Dayan, Margaret

2017-12-01

A 75-year-old hypertensive female with stable idiopathic intermediate uveitis presented with bilateral sequential optic neuropathy with optic disc swelling. The optic neuropathy in the first affected eye (right) was thought to be due to non-arteritic anterior ischaemic optic neuropathy (NAION). Asymptomatic left optic disc swelling was found at routine review 2 months later, and a diagnosis of giant cell arteritis (GCA) was sought. Temporal artery duplex ultrasound showed the "halo sign," but a subsequent temporal artery biopsy showed light-chain (AL) amyloidosis with no signs of giant cell arteritis. In this case, bilateral sequential ischaemic optic neuropathy mimicking non-arteritic anterior ischaemic optic neuropathy was the presenting sign of systemic amyloidosis involving the temporal arteries.

A preconditioning nerve lesion inhibits mechanical pain hypersensitivity following subsequent neuropathic injury

Directory of Open Access Journals (Sweden)

Wu Ann

2011-01-01

Full Text Available Abstract Background A preconditioning stimulus can trigger a neuroprotective phenotype in the nervous system - a preconditioning nerve lesion causes a significant increase in axonal regeneration, and cerebral preconditioning protects against subsequent ischemia. We hypothesized that a preconditioning nerve lesion induces gene/protein modifications, neuronal changes, and immune activation that may affect pain sensation following subsequent nerve injury. We examined whether a preconditioning lesion affects neuropathic pain and neuroinflammation after peripheral nerve injury. Results We found that a preconditioning crush injury to a terminal branch of the sciatic nerve seven days before partial ligation of the sciatic nerve (PSNL; a model of neuropathic pain induced a significant attenuation of pain hypersensitivity, particularly mechanical allodynia. A preconditioning lesion of the tibial nerve induced a long-term significant increase in paw-withdrawal threshold to mechanical stimuli and paw-withdrawal latency to thermal stimuli, after PSNL. A preconditioning lesion of the common peroneal induced a smaller but significant short-term increase in paw-withdrawal threshold to mechanical stimuli, after PSNL. There was no difference between preconditioned and unconditioned animals in neuronal damage and macrophage and T-cell infiltration into the dorsal root ganglia (DRGs or in astrocyte and microglia activation in the spinal dorsal and ventral horns. Conclusions These results suggest that prior exposure to a mild nerve lesion protects against adverse effects of subsequent neuropathic injury, and that this conditioning-induced inhibition of pain hypersensitivity is not dependent on neuroinflammation in DRGs and spinal cord. Identifying the underlying mechanisms may have important implications for the understanding of neuropathic pain due to nerve injury.

Super-low dose endotoxin pre-conditioning exacerbates sepsis mortality.

Science.gov (United States)

Chen, Keqiang; Geng, Shuo; Yuan, Ruoxi; Diao, Na; Upchurch, Zachary; Li, Liwu

2015-04-01

Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditionings with super-low or low dose endotoxin lipopolysaccharide (LPS) cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP). This is in opposite to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET) in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a novel mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

Super-low Dose Endotoxin Pre-conditioning Exacerbates Sepsis Mortality

Directory of Open Access Journals (Sweden)

Keqiang Chen

2015-04-01

Full Text Available Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditioning with super-low or low dose endotoxin lipopolysaccharide (LPS cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP. This is in contrast to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

Exercise-induced stunning continues for at least one hour: evaluation with quantitative gated single-photon emission tomography

Energy Technology Data Exchange (ETDEWEB)

Paul, A.K.; Hasegawa, Shinji; Yoshioka, Jun; Tsujimura, Eiichiro; Yamaguchi, Hitoshi; Tokita, Naoki; Maruyama, Atsushi; Xiuli, Mu; Nishimura, Tsunehiko [Division of Tracer Kinetics, Biomedical Research Center, Osaka University Medical School, Suita, Osaka (Japan)

1999-04-29

To elucidate the after-effect of exercise on left ventricular (LV) function, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were evaluated at 1 h after exercise and at rest by technetium-99m tetrofosmin gated myocardial single-photon emission tomography (SPET) using an automated program in 53 subjects. The subjects were grouped as follows: normal scan (n = 16), ischaemia (n = 19) and infarction (n = 18), based on the interpretation of perfusion images. Postexercise LVEF did not differ from resting LVEF in the groups with normal scan and infarction. In patients with ischaemia, postexercise EDV (90{+-}17 ml, mean {+-}SD) and ESV (44{+-}15 ml) were significantly higher than EDV (84{+-}15 ml, P = 0.001) and ESV (36{+-}14 ml, P<0.0005) at rest. LVEF was significantly depressed 1 h after exercise (53%{+-}9% vs 58%{+-}9%, P<0.0001). In ischaemic patients with depressed postexercise LVEF, LVEF difference between rest and postexercise showed a significant correlation with the sum of defect scores, which were reversible from exercise to rest perfusion images (r = 0.92, P<0.0001). These results indicate that exercise-induced LV dysfunction (myocardial stunning) continues for at least 1 h in ischaemic patients and that the extent of LVEF depression is determined by the severity of ischaemia. (orig.) With 7 figs., 19 refs.

Exercise-induced stunning continues for at least one hour: evaluation with quantitative gated single-photon emission tomography

International Nuclear Information System (INIS)

Paul, A.K.; Hasegawa, Shinji; Yoshioka, Jun; Tsujimura, Eiichiro; Yamaguchi, Hitoshi; Tokita, Naoki; Maruyama, Atsushi; Xiuli, Mu; Nishimura, Tsunehiko

1999-01-01

To elucidate the after-effect of exercise on left ventricular (LV) function, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were evaluated at 1 h after exercise and at rest by technetium-99m tetrofosmin gated myocardial single-photon emission tomography (SPET) using an automated program in 53 subjects. The subjects were grouped as follows: normal scan (n = 16), ischaemia (n = 19) and infarction (n = 18), based on the interpretation of perfusion images. Postexercise LVEF did not differ from resting LVEF in the groups with normal scan and infarction. In patients with ischaemia, postexercise EDV (90±17 ml, mean ±SD) and ESV (44±15 ml) were significantly higher than EDV (84±15 ml, P = 0.001) and ESV (36±14 ml, P<0.0005) at rest. LVEF was significantly depressed 1 h after exercise (53%±9% vs 58%±9%, P<0.0001). In ischaemic patients with depressed postexercise LVEF, LVEF difference between rest and postexercise showed a significant correlation with the sum of defect scores, which were reversible from exercise to rest perfusion images (r = 0.92, P<0.0001). These results indicate that exercise-induced LV dysfunction (myocardial stunning) continues for at least 1 h in ischaemic patients and that the extent of LVEF depression is determined by the severity of ischaemia. (orig.)

Corticotropin-releasing factor: effect on cerebral blood flow in physiologic and ischaemic conditions.

Science.gov (United States)

De Michele, Manuela; Touzani, Omar; Foster, Alan C; Fieschi, Cesare; Sette, Giuliano; McCulloch, James

2005-09-01

The expression of corticotrophin-releasing factor (CRF) receptors in cerebral arteries and arterioles suggests that CRF may modulate cerebral blood flow (CBF). In the present study, the effects of CRF, CRF-like peptides and the CRF broad spectrum antagonist DPhe-CRF on CBF have been investigated under normal physiologic conditions and in the margins of focal ischaemic insult. The experiments were carried out in anaesthetised and ventilated rats. Changes in CBF after subarachnoid microapplication of CRF and related peptides were assessed with a laser-Doppler flowmetry (LDF) probe. In the ischaemic animals, agents were injected approximately 60 minutes after permanent middle cerebral artery occlusion (MCAo). Microapplication of CRF and related peptides in normal rats into the subarachnoid space produced sustained concentration-dependent increases in CBF. This effect was attenuated by co-application with DPhe-CRF, which did not alter CBF itself. A second microapplication of CRF 30 min after the first failed to produce increases in CBF in normal animals. Microapplication of CRF in the subarachnoid space overlying the ischaemic cortex effected minor increases in CBF whereas D-Phe-CRF had no significant effect on CBF. Activation of the CRF peptidergic system increases CBF in the rat. Repeated activation of CRF receptors results in tachyphylaxis of the vasodilator response. CRF vasodilator response is still present after MCAo in the ischaemic penumbra, suggesting that the CRF peptidergic system may modulate CBF in ischaemic stroke.

Tranexamic Acid Does Not Influence Cardioprotection by Ischemic Preconditioning and Remote Ischemic Preconditioning

NARCIS (Netherlands)

van Caster, Patrick; Eiling, Sandra; Boekholt, Yvonne; Behmenburg, Friederike; Dorsch, Marianne; Heinen, André; Hollmann, Markus W.; Huhn, Ragnar

2018-01-01

Prior studies have suggested that the antifibrinolytic drug aprotinin increases the infarct size after ischemia and reperfusion (I/R) and attenuates the effect of ischemic preconditioning (IPC). Aprotinin was replaced by tranexamic acid (TXA) in clinical practice. Here, we investigated whether TXA

Leucocyte depletion attenuates the early increase in myocardial capillary permeability to small hydrophilic solutes following ischaemia and reperfusion

DEFF Research Database (Denmark)

Svendsen, Jesper Hastrup; Hansen, P R; Ali, S

1993-01-01

The aim was to assess the significance of polymorphonuclear leucocytes on the myocardial capillary permeability to a small hydrophilic indicator, on the vascular tone of the resistance vessels, and on contractile function following ischaemia and reperfusion.......The aim was to assess the significance of polymorphonuclear leucocytes on the myocardial capillary permeability to a small hydrophilic indicator, on the vascular tone of the resistance vessels, and on contractile function following ischaemia and reperfusion....

Roles of thioredoxin in nitric oxide-dependent preconditioning-induced tolerance against MPTP neurotoxin

International Nuclear Information System (INIS)

Chiueh, C.C.; Andoh, Tsugunobu; Chock, P. Boon

2005-01-01

Hormesis, a stress tolerance, can be induced by ischemic preconditioning stress. In addition to preconditioning, it may be induced by other means, such as gas anesthetics. Preconditioning mechanisms, which may be mediated by reprogramming survival genes and proteins, are obscure. A known neurotoxicant, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), causes less neurotoxicity in the mice that are preconditioned. Pharmacological evidences suggest that the signaling pathway of ·NO-cGMP-PKG (protein kinase G) may mediate preconditioning phenomenon. We developed a human SH-SY5Y cell model for investigating · NO-mediated signaling pathway, gene regulation, and protein expression following a sublethal preconditioning stress caused by a brief 2-h serum deprivation. Preconditioned human SH-SY5Y cells are more resistant against severe oxidative stress and apoptosis caused by lethal serum deprivation and 1-mehtyl-4-phenylpyridinium (MPP + ). Both sublethal and lethal oxidative stress caused by serum withdrawal increased neuronal nitric oxide synthase (nNOS/NOS1) expression and · NO levels to a similar extent. In addition to free radical scavengers, inhibition of nNOS, guanylyl cyclase, and PKG blocks hormesis induced by preconditioning. S-nitrosothiols and 6-Br-cGMP produce a cytoprotection mimicking the action of preconditioning tolerance. There are two distinct cGMP-mediated survival pathways: (i) the up-regulation of a redox protein thioredoxin (Trx) for elevating mitochondrial levels of antioxidant protein Mn superoxide dismutase (MnSOD) and antiapoptotic protein Bcl-2, and (ii) the activation of mitochondrial ATP-sensitive potassium channels [K(ATP)]. Preconditioning induction of Trx increased tolerance against MPP + , which was blocked by Trx mRNA antisense oligonucleotide and Trx reductase inhibitor. It is concluded that Trx plays a pivotal role in · NO-dependent preconditioning hormesis against MPTP/MPP +

Macro-elementwise preconditioning methods

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe

2012-01-01

Roč. 82, č. 10 (2012), s. 1952-1963 ISSN 0378-4754 Institutional research plan: CEZ:AV0Z30860518 Keywords : heterogeniety * elementwise preconditioning * block matrix partitioning * macro-elements Subject RIV: BA - General Mathematics Impact factor: 0.836, year: 2012 http://www.sciencedirect.com/science/journal/03784754

Retinal oximetry in patients with ischaemic retinal diseases

DEFF Research Database (Denmark)

Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

2017-01-01

The retinal oximeter is a new tool for non-invasive measurement of retinal oxygen saturation in humans. Several studies have investigated the associations between retinal oxygen saturation and retinal diseases. In the present systematic review, we examine whether there are associations between...... retinal oxygen saturation and retinal ischaemic diseases. We used PubMed and Embase to search for retinal oxygen saturation and retinal ischaemic diseases. Three separate searches identified a total of 79 publications. After two levels of manual screening, 10 studies were included: six about diabetic...... retinopathy (DR) and four about retinal vein occlusion. No studies about retinal artery occlusion were included. In diabetes, all studies found that increases in retinal venous oxygen saturation (rvSatO2 ) were associated with present as well as increasing levels of DR. Four of six studies also found...

Mean platelet volume as a risk stratification tool in the Emergency Department for evaluating patients with ischaemic stroke and TIA

International Nuclear Information System (INIS)

Dogan, N.O.; Karakurt, K.

2013-01-01

Objective: To investigate the variations of mean platelet volume in patients with ischaemic cerebrovascular complaints, and to find out its diagnostic utility in an acute setting to help risk stratification in patients with ischaemic stroke and transient ischaemic attacks. Methods: The prospective cross-sectional study was conducted at the Gazi University Hospital, Ankara, Turkey, from November 2009 to June 2010. It comprised 143 consecutive patients of acute ischaemic stroke, 39 patients of transient ischaemic attacks and 60 healthy volunteers. SPSS 13 was used for statistical analysis, and so were t-test, one-way analysis of variance test and correlation analysis. Statistical significance was accepted at p <0.05. Results: Mean platelet volume results were significantly higher in patients with cortical infarction and transient ischaemic attack compared to the control group (p <0.001 and p <0.002). A statistically significant increase was also noted in hospitalised patients when compared with discharged patients from the emergency department (p <0.036). A weak positive correlation was identified between the National Institute of Health Stroke Scores and mean platelet volume levels (r=0.207; p <0.001). A significant relationship was identified between mean platelet volume levels and previous stroke (p <0.005). Conclusion: The measurement of mean platelet volume levels may provide useful diagnostic and prognostic information to emergency physicians caring for patients with transient ischaemic attack and ischaemic stroke. In patients with suspected neurological ischaemic symptoms, high levels may be considered as an atherosclerotic risk factor. (author)

Atrial myxoma-related embolism resulting in acute limb ischaemia in ...

African Journals Online (AJOL)

Although atrial myxomas are uncommon, a thorough investigation of patients presenting with acute peripheral ischaemic .... reported.[9] Large left atrial tumours impairing intracardiac blood flow can ... In the case described here, obstruction of the mitral valve by the myxoma ... operation, preventing histological confirmation.

Bone marrow-derived mesenchymal stromal cell treatment in patients with severe ischaemic heart failure

DEFF Research Database (Denmark)

Mathiasen, Anders Bruun; Qayyum, Abbas Ali; Jørgensen, Erik

2015-01-01

AIMS: Regenerative treatment with mesenchymal stromal cells (MSCs) has been promising in patients with ischaemic heart failure but needs confirmation in larger randomized trials. We aimed to study effects of intra-myocardial autologous bone marrow-derived MSC treatment in patients with severe isc...... identified. CONCLUSION: Intra-myocardial injections of autologous culture expanded MSCs were safe and improved myocardial function in patients with severe ischaemic heart failure. STUDY REGISTRATION NUMBER: NCT00644410 (ClinicalTrials.gov)....... ischaemic heart failure. METHODS AND RESULTS: The MSC-HF trial is a randomized, double-blind, placebo-controlled trial. Patients were randomized 2 : 1 to intra-myocardial injections of MSC or placebo, respectively. The primary endpoint was change in left ventricular end-systolic volume (LVESV), measured...

The value of non-invasive techniques for the assessment of critical limb ischaemia

NARCIS (Netherlands)

Ubbink, D. T.; Tulevski, I. I.; den Hartog, D.; Koelemay, M. J.; Legemate, D. A.; Jacobs, M. J.

1997-01-01

OBJECTIVE: The European Consensus Document (ECD) defines critical ischaemia (CI) according to clinical (Fontaine) and blood pressure parameters. However, clinical symptoms may be non-specific and CI may exist without severely reduced blood pressures. This study prospectively investigated the

Osteoprotegerin concentrations and prognosis in acute ischaemic stroke

DEFF Research Database (Denmark)

Jensen, Jesper Khédri; Ueland, T; Gullestad, L

2010-01-01

Abstract. Jensen JK, Ueland T, Atar D, Gullestad L, Mickley H, Aukrust P, Januzzi JL (Odense University Hospital, Denmark; Rikshospitalet, Oslo, Norway; Massachusetts General Hospital, USA). Osteoprotegerin concentrations and prognosis in acute ischaemic stroke. J Intern Med 2009; doi: 10.1111/j...

Xanthelasmata, arcus corneae, and ischaemic vascular disease and death in general population: prospective cohort study

DEFF Research Database (Denmark)

Christoffersen, Mette; Frikke-Schmidt, Ruth; Schnohr, Peter

2011-01-01

To test the hypothesis that xanthelasmata and arcus corneae, individually and combined, predict risk of ischaemic vascular disease and death in the general population.......To test the hypothesis that xanthelasmata and arcus corneae, individually and combined, predict risk of ischaemic vascular disease and death in the general population....

{sup 18}F-FDG PET/CT imaging factors that predict ischaemic stroke in cancer patients

Energy Technology Data Exchange (ETDEWEB)

Kim, Jahae; Song, Ho-Chun [Chonnam National University Hospital, Department of Nuclear Medicine, Gwangju (Korea, Republic of); Choi, Kang-Ho [Chonnam National University Hospital, Cerebrovascular Center, Gwangju (Korea, Republic of); Chonnam National University Hwasun Hospital, Department of Neurology, Hwasun-gun, Jeollanam-do (Korea, Republic of); Kim, Joon-Tae; Park, Man-Seok; Cho, Ki-Hyun [Chonnam National University Hospital, Cerebrovascular Center, Gwangju (Korea, Republic of)

2016-11-15

{sup 18}F-FDG PET/CT can acquire both anatomical and functional images in a single session. We investigated which factors of {sup 18}F-FDG PET/CT imaging have potential as biomarkers for an increased risk of ischaemic stroke in cancer patients. From among cancer patients presenting with various neurological symptoms and hemiparesis, 134 were selected as eligible for this retrospective analysis. A new infarct lesion on brain MRI within 1 year of FDG PET/CT defined future ischaemic stroke. The target-to-background ratio (TBR) of each arterial segment was used to define arterial inflammation on PET imaging. Abdominal obesity was defined in terms of the area and proportion of visceral adipose tissue (VAT), subcutaneous adipose tissue and total adipose tissue (TAT) on a single CT slice at the umbilical level. Ischaemic stroke confirmed by MRI occurred in 30 patients. Patients with stroke had higher TBRs in the carotid arteries and abdominal aorta (P < 0.001) and a higher VAT proportion (P = 0.021) and TAT proportion (P = 0.041) than patients without stroke. Multiple logistic regression analysis showed that TBRs of the carotid arteries and abdominal aorta, VAT and TAT proportions, and the presence of a metabolically active tumour were significantly associated with future ischaemic stroke. Combining PET and CT variables improved the power for predicting future ischaemic stroke. Our findings suggest that arterial FDG uptake and hypermetabolic malignancy on PET and the VAT proportion on CT could be independent predictors of future ischaemic stroke in patients with cancer and could identify those patients who would benefit from medical treatment. (orig.)

Radiographers' preconditions for evidence-based radiography

International Nuclear Information System (INIS)

Ahonen, Sanna-Mari; Liikanen, Eeva

2010-01-01

Evidence-based practice (EBP) is essential in today's health care, but its establishment requires several preconditions from individuals and organizations (e.g. knowledge, understanding, attitudes, abilities, self-confidence, support, and resources). Previous studies suggest that radiographers do generate and use evidence in their work, but evidence-based radiography (EBR) is not yet used routinely as established practice, especially in terms of research utilization. This paper aims to describe radiographers' preconditions for EBR, and their participation in research activities. Main focus is on research utilization. Using an electronic questionnaire developed for this study, a survey was conducted: data collected from Finnish radiographers and radiotherapists (N = 438) were analysed both statistically and qualitatively. The final response rate was 39%. The results suggest radiographers' preconditions for EBR to consist of knowledge of research, significance of research activities, research-orientated way of working, and support. In addition, adequate resourcing is essential. Reading scientific journals, participation in research activities, a higher degree of education, and senior post seem to be significant promoters of EBR and research utilization. The results support the notion that EBR, and especially research utilization, are not yet well-established in Finland, and radiographers' viewpoints concerning the role and significance of research evidence and research activities still seem to vary.

Selective impairments in spatial memory after ischaemic stroke

NARCIS (Netherlands)

Kessels, RPC; de Haan, EHF; Kappelle, LJ; Postma, A

2002-01-01

There is evidence that object-location memory consists of three separate processes, that is, positional memory, binding of objects to locations, and a possible integration mechanism. A group of 26 patients with lesions following ischaemic stroke was studied to find evidence for selective impairments

Ischaemic stroke in hyperthyroidism without cardiac arrhythmia - A ...

African Journals Online (AJOL)

BACKGROUND: The relationship between hyperthyroidism and stroke is well established in the setting of atrial fibrillation. However there is limited literature for ischaemic stroke occurring in hyperthyroidism without cardiac arrhythmia. No such case had been described in South East Nigeria. METHOD: This report highlights ...

Plasma renin activity in patients with ischaemic heart disease

International Nuclear Information System (INIS)

Urbanek, J.; Hofman, O.; Reisenauer, R.; Slaby, A.

1977-01-01

Plasma renin activity (PRA) stimulated by upright posture was measured in 300 men aged 45-64 years using a radioimmunoassay of angiotensin-I. The examined subjects were normotensive or patients with benign essential hypertension and were divided into 6 groups according to the absence of manifest atherosclerosis, the presence of definite angina pectoris or a history of myocardial infarction. Each group contained 50 unselected subjects, with a comparable mean age. Significant differences in mean PRA were found between corresponding groups of hypertensives and normotensives, the values in hypertensives being lower. The percentage of low renin values was higher in hypertensives with ischaemic heart disease than in other groups. It is suggested that this finding might be explained by functional disturbances in the kidneys in hypertensives with ischaemic heart disease. (orig.) [de

Plasma renin activity in patients with ischaemic heart disease

Energy Technology Data Exchange (ETDEWEB)

Urbanek, J; Hofman, O; Reisenauer, R; Slaby, A [Karlova Universita, Prague (Czechoslovakia). Inst. of Biophysics and Nuclear Medicine; Karlova Universita, Prague (Czechoslovakia). IV. Dept. of Internal Medicine; Vyzkumny Ustav Endokrinologicky, Prague [Czechoslovakia

1977-04-01

Plasma renin activity (PRA) stimulated by upright posture was measured in 300 men aged 45 to 64 years using a radioimmunoassay of angiotensin-I. The examined subjects were normotensive or patients with benign essential hypertension and were divided into 6 groups according to the absence of manifest atherosclerosis, the presence of definite angina pectoris or a history of myocardial infarction. Each group contained 50 unselected subjects, with a comparable mean age. Significant differences in mean PRA were found between corresponding groups of hypertensives and normotensives, the values in hypertensives being lower. The percentage of low renin values was higher in hypertensives with ischaemic heart disease than in other groups. It is suggested that this finding might be explained by functional disturbances in the kidneys in hypertensives with ischaemic heart disease.

Orderings for conjugate gradient preconditionings

Science.gov (United States)

Ortega, James M.

1991-01-01

The effect of orderings on the rate of convergence of the conjugate gradient method with SSOR or incomplete Cholesky preconditioning is examined. Some results also are presented that help to explain why red/black ordering gives an inferior rate of convergence.

Kronecker Products on Preconditioning

KAUST Repository

Gao, Longfei

2013-08-01

Numerical techniques for linear systems arising from discretization of partial differential equations are nowadays essential for understanding the physical world. Among these techniques, iterative methods and the accompanying preconditioning techniques have become increasingly popular due to their great potential on large scale computation. In this work, we present preconditioning techniques for linear systems built with tensor product basis functions. Efficient algorithms are designed for various problems by exploiting the Kronecker product structure in the matrices, inherited from tensor product basis functions. Specifically, we design preconditioners for mass matrices to remove the complexity from the basis functions used in isogeometric analysis, obtaining numerical performance independent of mesh size, polynomial order and continuity order; we also present a compound iteration preconditioner for stiffness matrices in two dimensions, obtaining fast convergence speed; lastly, for the Helmholtz problem, we present a strategy to `hide\\' its indefiniteness from Krylov subspace methods by eliminating the part of initial error that corresponds to those negative generalized eigenvalues. For all three cases, the Kronecker product structure in the matrices is exploited to achieve high computational efficiency.

Decentralisation in developing countries: preconditions for successful implementation

Directory of Open Access Journals (Sweden)

Yasin Olum

2014-07-01

Full Text Available Decentralisation has been implemented and is being implemented in many developing countries without much success. Although several unique factors inhibit the implementation of decentralisation in individual countries, the paper argues that there are six pre-conditions that these countries should fulfill before decentralisation can be successfully implemented. These preconditions are: institutional mechanisms; creation of spaces for participation; political will and civil will; capacity development at the local level; careful implementation; and democratic governance.

Patterns of neonatal hypoxic-ischaemic brain injury

International Nuclear Information System (INIS)

Vries, Linda S. de; Groenendaal, Floris

2010-01-01

Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome. (orig.)

Patterns of neonatal hypoxic-ischaemic brain injury

Energy Technology Data Exchange (ETDEWEB)

Vries, Linda S. de [University Medical Centre, Department of Neonatology, Wilhelmina Children' s Hospital, Utrecht (Netherlands); Wilhelmina Children' s Hospital, University Medical Centre, Department of Neonatology, KE 04.123.1, P.O. Box 85090, Utrecht (Netherlands); Groenendaal, Floris [University Medical Centre, Department of Neonatology, Wilhelmina Children' s Hospital, Utrecht (Netherlands)

2010-06-15

Enormous progress has been made in assessing the neonatal brain, using magnetic resonance imaging (MRI). In this review, we will describe the use of MRI and proton magnetic resonance spectroscopy in detecting different patterns of brain injury in (full-term) human neonates following hypoxic-ischaemic brain injury and indicate the relevance of these findings in predicting neurodevelopmental outcome. (orig.)

Magnetic resonance imaging assessment of intraventricular dyssynchrony and delayed enhancement as predictors of response to cardiac resynchronization therapy in patients with heart failure of ischaemic and non-ischaemic etiologies

International Nuclear Information System (INIS)

Petryka, Joanna; Miśko, Jolanta; Przybylski, Andrzej; Śpiewak, Mateusz; Małek, Łukasz A.; Werys, Konrad; Mazurkiewicz, Łukasz; Gepner, Katarzyna; Croisille, Pierre; Demkow, Marcin; Rużyłło, Witold

2012-01-01

Purpose: To assess the value of dyssynchrony and myocardial viability assessment by cardiac magnetic resonance (CMR) in prediction of response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) of both ischaemic and non-ischaemic etiologies. Materials and methods: Patients scheduled for CRT in NYHA class II–IV, left ventricular ejection fraction <35%, QRS ≥ 120 ms were included. Tagged cine and late gadolinium enhancement (LGE) images were performed. Dyssynchrony was assessed with inTag toolbox and LGE was quantified using cutoff value at half of maximal signal in the scar. Cardiopulmonary exercise test, echocardiography and blood testing for NT-proBNP levels were done at baseline and 6 months after CRT. Results: 52 patients (age 60.3 ± 13 years) were included. 26 patients (50%) met response criteria. The ischaemic etiology of HF was more frequent (69% vs. 31%, p = 0.002), the percent of LGE was higher (7.7% [0–13.5%] vs. 19.0% (0–31.9%], p = 0.013), regional vector of circumferential strain variance (RVV) was lower (0.27 ± 0.08 vs. 0.34 ± 0.09, p = 0.009) and uniformity of radial strain was higher (0.72 ± 0.25 vs. 0.56 ± 0.29, p = 0.046) in non-responders vs. responders. Multivariate logistic regression showed that RVV predicted response to CRT (HR 2.3, 95% CI 1.02–5.02, p = 0.0430) independently of LGE and the etiology of heart failure. In the subgroup of patients with ischaemic HF the extend of transmural scar within myocardium was higher in non-responders vs. responders (26.3% vs. 15.0% respectively, p = 0.01) and was a predictor of response to CRT in univariable analysis (HR 0.87, 95% CI 0.77–0.98, p = 0.025) providing the sensitivity of 76% and specificity of 75% at the cutoff point of 18% in the prediction of poor response to CRT. In patients with non-ischaemic HF QRS was wider (162 ms vs. 140 ms, p = 0.04), regional vector of strain variance (RVV) was higher (0.39 vs. 0.25, p = 0.002) and uniformity of radial

Magnetic resonance imaging assessment of intraventricular dyssynchrony and delayed enhancement as predictors of response to cardiac resynchronization therapy in patients with heart failure of ischaemic and non-ischaemic etiologies

Energy Technology Data Exchange (ETDEWEB)

Petryka, Joanna, E-mail: joannapetryka@hotmail.com [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Miśko, Jolanta [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Przybylski, Andrzej [Department of Arrhythmia, Institute of Cardiology, Warsaw (Poland); Śpiewak, Mateusz [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Małek, Łukasz A. [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiology and Interventional Angiology, Institute of Cardiology, Warsaw (Poland); Werys, Konrad [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Mazurkiewicz, Łukasz [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiomyopathy, Institute of Cardiology, Warsaw (Poland); Gepner, Katarzyna [Department of Coronary Artery Disease, Institute of Cardiology, Warsaw (Poland); Croisille, Pierre [Creatis Laboratory, UMR CNRS 5515, INSERM, U1044, CHU Saint-Etienne, Universite de Lyon (France); Demkow, Marcin [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Rużyłło, Witold [Institute of Cardiology, Warsaw (Poland)

2012-10-15

Purpose: To assess the value of dyssynchrony and myocardial viability assessment by cardiac magnetic resonance (CMR) in prediction of response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) of both ischaemic and non-ischaemic etiologies. Materials and methods: Patients scheduled for CRT in NYHA class II–IV, left ventricular ejection fraction <35%, QRS ≥ 120 ms were included. Tagged cine and late gadolinium enhancement (LGE) images were performed. Dyssynchrony was assessed with inTag toolbox and LGE was quantified using cutoff value at half of maximal signal in the scar. Cardiopulmonary exercise test, echocardiography and blood testing for NT-proBNP levels were done at baseline and 6 months after CRT. Results: 52 patients (age 60.3 ± 13 years) were included. 26 patients (50%) met response criteria. The ischaemic etiology of HF was more frequent (69% vs. 31%, p = 0.002), the percent of LGE was higher (7.7% [0–13.5%] vs. 19.0% (0–31.9%], p = 0.013), regional vector of circumferential strain variance (RVV) was lower (0.27 ± 0.08 vs. 0.34 ± 0.09, p = 0.009) and uniformity of radial strain was higher (0.72 ± 0.25 vs. 0.56 ± 0.29, p = 0.046) in non-responders vs. responders. Multivariate logistic regression showed that RVV predicted response to CRT (HR 2.3, 95% CI 1.02–5.02, p = 0.0430) independently of LGE and the etiology of heart failure. In the subgroup of patients with ischaemic HF the extend of transmural scar within myocardium was higher in non-responders vs. responders (26.3% vs. 15.0% respectively, p = 0.01) and was a predictor of response to CRT in univariable analysis (HR 0.87, 95% CI 0.77–0.98, p = 0.025) providing the sensitivity of 76% and specificity of 75% at the cutoff point of 18% in the prediction of poor response to CRT. In patients with non-ischaemic HF QRS was wider (162 ms vs. 140 ms, p = 0.04), regional vector of strain variance (RVV) was higher (0.39 vs. 0.25, p = 0.002) and uniformity of radial

Management of Preconditioned Calves and Impacts of Preconditioning.

Science.gov (United States)

Hilton, W Mark

2015-07-01

When studying the practice of preconditioning (PC) calves, many factors need to be examined to determine if cow-calf producers should make this investment. Factors such as average daily gain, feed efficiency, available labor, length of the PC period, genetics, and marketing options must be analyzed. The health sales price advantage is an additional benefit in producing and selling PC calves but not the sole determinant of PC's financially feasibility. Studies show that a substantial advantage of PC is the selling of additional pounds at a cost of gain well below the marginal return of producing those additional pounds. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of transoesophageal echocardiography on therapy and prognosis in young patients with TIA or ischaemic stroke

NARCIS (Netherlands)

Rettig, T. C. D.; Bouma, B. J.; van den Brink, R. B. A.

2009-01-01

Objective. To determine the influence of transoesophageal echocardiography (TEE) on therapy and prognosis in patients with cryptogenic transient ischaemic attack (TIA) or ischaemic stroke under the age of 50 years.Methods and results. We evaluated all patients aged 50 and under who were referred to

ABO blood group distribution and ischaemic heart disease

International Nuclear Information System (INIS)

Lutfullah, A.; Bhatti, T.A.; Hanif, A.; Shaikh, S.H.

2011-01-01

To study the association of ABO blood groups with ischaemic heart disease (IHD) in our setting. Analytic comparative study. Department of Cardiology, Mayo hospital, Lahore over a period of two years from January 2008 to December 2009. The study group included 907 patients of IHD. The distribution of ABO blood groups in IHD patients was compared with the control group of 907 non-IHD individuals. Data was analyzed using SPSS 16. Chi-square test for significance was used. P-value less than 0.05 was taken as significant. In this study, the following pattern of ABO blood groups was observed in IHD patients and non-IHD patients respectively : Blood group A 251 (27.67%) and 248 (27.34%); Blood group B 329 (36.27%) and 358 (39.47%); Blood group O 235 (25.90%) and 240 (24.46%); Blood group AB 92 (10.14%) and 61 (6.72%), P-value = 0.06. There is no association of ABO blood groups and ischaemic heart disease. (author)

Nonlinear Multiplicative Schwarz Preconditioning in Natural Convection Cavity Flow

KAUST Repository

Liu, Lulu

2017-03-17

A natural convection cavity flow problem is solved using nonlinear multiplicative Schwarz preconditioners, as a Gauss-Seidel-like variant of additive Schwarz preconditioned inexact Newton (ASPIN). The nonlinear preconditioning extends the domain of convergence of Newton’s method to high Rayleigh numbers. Convergence performance varies widely with respect to different groupings of the fields of this multicomponent problem, and with respect to different orderings of the groupings.

Nonlinear Multiplicative Schwarz Preconditioning in Natural Convection Cavity Flow

KAUST Repository

Liu, Lulu; Zhang, Wei; Keyes, David E.

2017-01-01

A natural convection cavity flow problem is solved using nonlinear multiplicative Schwarz preconditioners, as a Gauss-Seidel-like variant of additive Schwarz preconditioned inexact Newton (ASPIN). The nonlinear preconditioning extends the domain of convergence of Newton’s method to high Rayleigh numbers. Convergence performance varies widely with respect to different groupings of the fields of this multicomponent problem, and with respect to different orderings of the groupings.

Ischaemic heart disease in Aminu Kano Teaching Hospital, Kano ...

African Journals Online (AJOL)

Ischaemic heart disease in Aminu Kano Teaching Hospital, Kano, Nigeria: a 5 ... Nigerian Journal of Medicine ... Open Access DOWNLOAD FULL TEXT ... it a prevalence of 0.9% of medical conditions and 3.4% of all cardiovascular cases.

The association between early menopause and risk of ischaemic heart disease: Influence of Hormone Therapy

DEFF Research Database (Denmark)

Løkkegaard, Ellen Christine Leth; Andersen, Zorana Jovanovic; Heitmann, Berit Lilienthal

2006-01-01

Randomised clinical trials find no protection against development of ischaemic heart disease by use of Hormone Therapy (HT) after the age of 50 years. Observational studies suggest that early menopause is a risk factor for ischaemic heart disease. Yet, a clinical very relevant question is whether...... HT reduces this risk associated with early menopause....

Hyperbaric oxygen preconditioning protects against traumatic brain injury at high altitude.

Science.gov (United States)

Hu, S L; Hu, R; Li, F; Liu, Z; Xia, Y Z; Cui, G Y; Feng, H

2008-01-01

Recent studies have shown that preconditioning with hyperbaric oxygen (HBO) can reduce ischemic and hemorrhagic brain injury. We investigated effects of HBO preconditioning on traumatic brain injury (TBI) at high altitude and examined the role of matrix metalloproteinase-9 (MMP-9) in such protection. Rats were randomly divided into 3 groups: HBO preconditioning group (HBOP; n = 13), high-altitude group (HA; n = 13), and high-altitude sham operation group (HASO; n = 13). All groups were subjected to head trauma by weight-drop device, except for HASO group. HBOP rats received 5 sessions of HBO preconditioning (2.5 ATA, 100% oxygen, 1 h daily) and then were kept in hypobaric chamber at 0.6 ATA (to simulate pressure at 4000m altitude) for 3 days before operation. HA rats received control pretreatment (1 ATA, room air, 1 h daily), then followed the same procedures as HBOP group. HASO rats were subjected to skull opening only without brain injury. Twenty-four hours after TBI, 7 rats from each group were examined for neurological function and brain water content; 6 rats from each group were killed for analysis by H&E staining and immunohistochemistry. Neurological outcome in HBOP group (0.71 +/- 0.49) was better than HA group (1.57 +/- 0.53; p < 0.05). Preconditioning with HBO significantly reduced percentage of brain water content (86.24 +/- 0.52 vs. 84.60 +/- 0.37; p < 0.01). Brain morphology and structure seen by light microscopy was diminished in HA group, while fewer pathological injuries occurred in HBOP group. Compared to HA group, pretreatment with HBO significantly reduced the number of MMP-9-positive cells (92.25 +/- 8.85 vs. 74.42 +/- 6.27; p < 0.01). HBO preconditioning attenuates TBI in rats at high altitude. Decline in MMP-9 expression may contribute to HBO preconditioning-induced protection of brain tissue against TBI.

Dehydration is an independent predictor of discharge outcome and admission cost in acute ischaemic stroke.

Science.gov (United States)

Liu, C-H; Lin, S-C; Lin, J-R; Yang, J-T; Chang, Y-J; Chang, C-H; Chang, T-Y; Huang, K-L; Ryu, S-J; Lee, T-H

2014-09-01

Our aim was to investigate the influence of admission dehydration on the discharge outcome in acute ischaemic and hemorrhagic stroke. Between January 2009 and December 2011, 4311 ischaemic and 1371 hemorrhagic stroke patients from the stroke registry of Chang Gung healthcare system were analyzed. The eligible patients were identified according to inclusion/exclusion criteria. In total, 2570 acute ischaemic and 573 acute hemorrhagic stroke patients were finally recruited. According to the blood urea nitrogen (BUN) to creatinine (Cr) ratio (BUN/Cr), these patients were divided into dehydrated (BUN/Cr ≥ 15) and non-dehydrated (BUN/Cr dehydration had higher infection rates (P = 0.006), worse discharge BI (62.8 ± 37.4 vs. 73.4 ± 32.4, P dehydration. However, acute hemorrhagic stroke with or without admission dehydration showd no difference in admission costs (P = 0.618) and discharge outcomes (BI, P = 0.058; mRS, P = 0.058). Admission dehydration is associated with worse discharge outcomes and higher admission costs in acute ischaemic stroke but not in hemorrhagic stroke. © 2014 The Author(s) European Journal of Neurology © 2014 EAN.

INFLAMMATORY MARKERS IN ACUTE ISCHAEMIC STROKE IN RELATION TO CLINICAL SEVERITY AND EARLY OUTCOME

Directory of Open Access Journals (Sweden)

S. Gopi

2018-01-01

Full Text Available BACKGROUND Biochemical markers of inflammation could be useful to predict severity of stroke in acute phase. Stroke is the third cause of mortality and the first cause of disability. Recent literature have demonstrated that inflammation contributes to all phases of atherosclerosis. The results of researchers suggest that atherosclerosis is an inflammatory disease. The aim of the study is to assess the1. Level of peripheral inflammatory markers in acute ischaemic stroke and their relation to severity of acute stroke. 2. Value of inflammatory markers in predicting the short-term outcome and disability at the end of six months. MATERIALS AND METHODS This is a prospective case control study for 6 months done from September 2014 to August 2016 in 100 patients of acute ischaemic stroke within first 5 days of symptom onset in comparison >18 years of age with 50 age and sex matched controls. Blood samples for all cases and controls were sent for erythrocyte sedimentation rate, Neutrophil-to-Lymphocyte Ratio (NLR, hs-C-reactive protein, mean platelet volume, serum ferritin, serum albumin and S. gamma-glutamyl transferase at admission. RESULTS The mean values of ESR, NLR, hs-CRP in all the cases are higher when compared to the controls and are statistically significant, whereas the mean values of MPV, S. ferritin, S. albumin and GGT in cases are lower when compared to controls, but are within normal range and difference is statistically significant except ferritin. ESR, hs-CRP has significant correlation with severity of acute ischaemic stroke. The mean values of these markers increased with increase in severity. Serum albumin has significant correlation with severity of acute ischaemic stroke with mean values of these markers decreasing with increase in severity of stroke. There is no significant correlation of the inflammatory markers in present study with the short-term outcome. CONCLUSION Inflammation plays an important role in the pathogenesis of non

Expression of tumor necrosis factor alpha after focal cerebral ischaemia in the rat

NARCIS (Netherlands)

Buttini, M; Appel, K; Sauter, A; GebickeHaerter, PJ; Boddeke, HWGM

Induction of tumor necrosis factor alpha was studied in the brain of rats after focal cerebral ischaemia by occlusion of the left middle cerebral artery. Using a specific antisense riboprobe for in situ hybridization histochemistry, cells positive for tumor necrosis factor alpha messenger RNA were

Preconditioned alternating direction method of multipliers for inverse problems with constraints

International Nuclear Information System (INIS)

Jiao, Yuling; Jin, Qinian; Lu, Xiliang; Wang, Weijie

2017-01-01

We propose a preconditioned alternating direction method of multipliers (ADMM) to solve linear inverse problems in Hilbert spaces with constraints, where the feature of the sought solution under a linear transformation is captured by a possibly non-smooth convex function. During each iteration step, our method avoids solving large linear systems by choosing a suitable preconditioning operator. In case the data is given exactly, we prove the convergence of our preconditioned ADMM without assuming the existence of a Lagrange multiplier. In case the data is corrupted by noise, we propose a stopping rule using information on noise level and show that our preconditioned ADMM is a regularization method; we also propose a heuristic rule when the information on noise level is unavailable or unreliable and give its detailed analysis. Numerical examples are presented to test the performance of the proposed method. (paper)

Rapamycin preconditioning attenuates transient focal cerebral ischemia/reperfusion injury in mice.

Science.gov (United States)

Yin, Lele; Ye, Shasha; Chen, Zhen; Zeng, Yaoying

2012-12-01

Rapamycin, an mTOR inhibitor and immunosuppressive agent in clinic, has protective effects on traumatic brain injury and neurodegenerative diseases. But, its effects on transient focal ischemia/reperfusion disease are not very clear. In this study, we examined the effects of rapamycin preconditioning on mice treated with middle cerebral artery occlusion/reperfusion operation (MCAO/R). We found that the rapamycin preconditioning by intrahippocampal injection 20 hr before MCAO/R significantly improved the survival rate and longevity of mice. It also decreased the neurological deficit score, infracted areas and brain edema. In addition, rapamycin preconditioning decreased the production of NF-κB, TNF-α, and Bax, but not Bcl-2, an antiapoptotic protein in the ischemic area. From these results, we may conclude that rapamycin preconditioning attenuate transient focal cerebral ischemia/reperfusion injury and inhibits apoptosis induced by MCAO/R in mice.

The risk of ischaemic stroke in primary antiphospholipid syndrome patients

DEFF Research Database (Denmark)

Radin, M; Schreiber, K; Cecchi, I

2018-01-01

BACKGROUND AND PURPOSE: The most common neurological manifestation of antiphospholipid syndrome (APS) is ischaemic stroke. Identifying patients with APS at high risk for developing any thrombotic event remains a major challenge. In this study, the aim was to identify predictive factors of ischaemic...... thrombosis and were receiving vitamin K antagonist (VKA), with international normalized ratio target 2-3; one patient had a history of a previous arterial event receiving treatment with VKA target international normalized ratio 2-3 plus low dose aspirin; and one patient had a history of previous pregnancy...... morbidity receiving only low dose aspirin. Time in the therapeutic range for patients receiving VKA was 77.7% (SD 6.6%). Hypercholesterolaemia was significantly higher in patients with confirmed stroke compared to those without (P

ExStroke Pilot Trial of the effect of repeated instructions to improve physical activity after ischaemic stroke

DEFF Research Database (Denmark)

Boysen, Gudrun; Krarup, Lars-Henrik; Zeng, Xianrong

2009-01-01

To investigate if repeated verbal instructions about physical activity to patients with ischaemic stroke could increase long term physical activity.......To investigate if repeated verbal instructions about physical activity to patients with ischaemic stroke could increase long term physical activity....

The Role of Ionospheric Outflow Preconditioning in Determining Storm Geoeffectiveness

Science.gov (United States)

Welling, D. T.; Liemohn, M. W.; Ridley, A. J.

2012-12-01

It is now well accepted that ionospheric outflow plays an important role in the development of the plasma sheet and ring current during geomagnetic storms. Furthermore, even during quiet times, ionospheric plasma populates the magnetospheric lobes, producing a reservoir of hydrogen and oxygen ions. When the Interplanetary Magnetic Field (IMF) turns southward, this reservoir is connected to the plasma sheet and ring current through magnetospheric convection. Hence, the conditions of the ionosphere and magnetospheric lobes leading up to magnetospheric storm onset have important implications for storm development. Despite this, there has been little research on this preconditioning; most global simulations begin just before storm onset, neglecting preconditioning altogether. This work explores the role of preconditioning in determining the geoeffectiveness of storms using a coupled global model system. A model of ionospheric outflow (the Polar Wind Outflow Model, PWOM) is two-way coupled to a global magnetohydrodynamic model (the Block-Adaptive Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), which in turn drives a ring current model (the Ring current Atmosphere interactions Model, RAM). This unique setup is used to simulate an idealized storm. The model is started at many different times, from 1 hour before storm onset to 12 hours before. The effects of storm preconditioning are examined by investigating the total ionospheric plasma content in the lobes just before onset, the total ionospheric contribution in the ring current just after onset, and the effects on Dst, magnetic elevation angle at geosynchronous, and total ring current energy density. This experiment is repeated for different solar activity levels as set by F10.7 flux. Finally, a synthetic double-dip storm is constructed to see how two closely spaced storms affect each other by changing the preconditioning environment. It is found that preconditioning of the magnetospheric lobes via ionospheric

Rural water-supply and sanitation planning: The use of socioeconomic preconditions in project identification

Science.gov (United States)

Warner, Dennis B.

1984-02-01

Recognition of the socioeconomic preconditions for successful rural water-supply and sanitation projects in developing countries is the key to identifying a new project. Preconditions are the social, economic and technical characteristics defining the project environment. There are two basic types of preconditions: those existing at the time of the initial investigation and those induced by subsequent project activities. Successful project identification is dependent upon an accurate recognition of existing constraints and a carefully tailored package of complementary investments intended to overcome the constraints. This paper discusses the socioeconomic aspects of preconditions in the context of a five-step procedure for project identification. The procedure includes: (1) problem identification; (2) determination of socioeconomic status; (3) technology selection; (4) utilization of support conditions; and (5) benefit estimation. Although the establishment of specific preconditions should be based upon the types of projects likely to be implemented, the paper outlines a number of general relationships regarding favourable preconditions in water and sanitation planning. These relationships are used within the above five-step procedure to develop a set of general guidelines for the application of preconditions in the identification of rural water-supply and sanitation projects.

SAJS SAJS

African Journals Online (AJOL)

Yellon DM, Baxter GF, Garcia-Dorado D, Heusch G, Sumeray MS. Ischae- mic preconditioning: present position and future directions. Cardiovasc Res. 1998 ... Lloris-Carsi JM, Cejalvo D, Toledo-Pereyra LH, Calvo MA, Suzuki S. Pre- conditioning: effect upon lesion modulation in warm ischaemia. Transplant. Proc 1993; 25: ...

Evolution of DWI signal abnormalities after transient ischemic attack and minor ischaemic stroke

LENUS (Irish Health Repository)

Merwick, A

2011-05-01

Background: Diffusion weighted imaging (DWI) signal abnormality after transient ischaemic attack (TIA) predicts early stroke, independently of other risk markers included in the ABCD3-I score. Early stroke recurrence detected on follow-up DWI after the acute-phase DWI may identify patients at high risk for subsequent clinicalstrokesstroke, cognitive impairment, and seizures. We aimed to determine the evolution of acute DWI lesions and rate of new ischaemic lesion (NIL) occurrence on follow-up DWI after TIA and minor stroke.\\r\

[The relationship between ischemic preconditioning-induced infarction size limitation and duration of test myocardial ischemia].

Science.gov (United States)

Blokhin, I O; Galagudza, M M; Vlasov, T D; Nifontov, E M; Petrishchev, N N

2008-07-01

Traditionally infarction size reduction by ischemic preconditioning is estimated in duration of test ischemia. This approach limits the understanding of real antiischemic efficacy of ischemic preconditioning. Present study was performed in the in vivo rat model of regional myocardial ischemia-reperfusion and showed that protective effect afforded by ischemic preconditioning progressively decreased with prolongation of test ischemia. There were no statistically significant differences in infarction size between control and preconditioned animals when the duration of test ischemia was increased up to 1 hour. Preconditioning ensured maximal infarction-limiting effect in duration of test ischemia varying from 20 to 40 minutes.

Saliva/serum ghrelin, obestatin and homocysteine levels in patients with ischaemic heart disease

Science.gov (United States)

Kilic, Nermin; Dagli, Necati; Aydin, Suleyman; Erman, Fazilet; Bek, Yuksel; Akin, Okhan; Kilic, SS; Erdemli, Haci Kemal; Alacam, Hasan

2017-01-01

Summary Background: We aimed to compare ghrelin, obestatin, homocysteine (Hcy), vitamin B12 and folate levels in the serum and saliva of ischaemic heart disease patients. Methods: Serum and saliva were collected from 33 ischaemic heart disease (IHD) patients and 28 age- and body mass index-matched healthy individuals. Levels of acylated and desacylated ghrelin, obestatin and Hcy were determined using the ELISA method. Results: Acylated ghrelin, desacylated ghrelin and obestatin levels in the saliva were found to be higher than those in the serum of the control group, while acylated and desacylated ghrelin levels in the saliva were significantly lower than those in the serum. Obestatin levels were higher in IHD patients (p = 0.001). Saliva and serum vitamin B12 and folate levels in IHD patients were significantly lower than in the control group (p = 0.001). Conclusions: It was determined that serum ghrelin levels increased in ischaemic heart disease patients, while serum levels of obestatin decreased. PMID:28759087

Fourier analysis of finite element preconditioned collocation schemes

Science.gov (United States)

Deville, Michel O.; Mund, Ernest H.

1990-01-01

The spectrum of the iteration operator of some finite element preconditioned Fourier collocation schemes is investigated. The first part of the paper analyses one-dimensional elliptic and hyperbolic model problems and the advection-diffusion equation. Analytical expressions of the eigenvalues are obtained with use of symbolic computation. The second part of the paper considers the set of one-dimensional differential equations resulting from Fourier analysis (in the tranverse direction) of the 2-D Stokes problem. All results agree with previous conclusions on the numerical efficiency of finite element preconditioning schemes.

The role of atrial fibrillation on mortality and morbidity in patients with ischaemic stroke.

Science.gov (United States)

Cögen, Etem Emre; Tombul, Temel; Yildirim, Gökhan; Odabas, Faruk Omer; Sayin, Refah

2013-12-01

To investigate the impact of atrial fibrillation on mortality and morbidity in ischaemic stroke patients. The retrospective study was conducted at the Neurology Clinic, Faculty of Medicine, Yuzuncu Yil University, Van, Turkey, and comprised records of ischaemic stroke patients hospitalised between January 2006 and September 2009. SPSS 13 was used for statistical analysis. Of the 404 patients in the study, 69 (17.1%) had atrial fibrilation. The mean age of such patients was 66.78 +/- 12.23 years compared to 61.01 +/- 15.11 years for the rest. Besides 47 (68.1%) of these patients were females. According to the modified Rankin Scale scores, the degree of disability was significantly higher at the time of arrival and discharge, and mortality rates were significantly higher also (p Atrial fibrillation affected the prognosis of ischaemic stroke adversely in terms of mortality and morbidity.

Brain Injury Lesion Imaging Using Preconditioned Quantitative Susceptibility Mapping without Skull Stripping.

Science.gov (United States)

Soman, S; Liu, Z; Kim, G; Nemec, U; Holdsworth, S J; Main, K; Lee, B; Kolakowsky-Hayner, S; Selim, M; Furst, A J; Massaband, P; Yesavage, J; Adamson, M M; Spincemallie, P; Moseley, M; Wang, Y

2018-04-01

Identifying cerebral microhemorrhage burden can aid in the diagnosis and management of traumatic brain injury, stroke, hypertension, and cerebral amyloid angiopathy. MR imaging susceptibility-based methods are more sensitive than CT for detecting cerebral microhemorrhage, but methods other than quantitative susceptibility mapping provide results that vary with field strength and TE, require additional phase maps to distinguish blood from calcification, and depict cerebral microhemorrhages as bloom artifacts. Quantitative susceptibility mapping provides universal quantification of tissue magnetic property without these constraints but traditionally requires a mask generated by skull-stripping, which can pose challenges at tissue interphases. We evaluated the preconditioned quantitative susceptibility mapping MR imaging method, which does not require skull-stripping, for improved depiction of brain parenchyma and pathology. Fifty-six subjects underwent brain MR imaging with a 3D multiecho gradient recalled echo acquisition. Mask-based quantitative susceptibility mapping images were created using a commonly used mask-based quantitative susceptibility mapping method, and preconditioned quantitative susceptibility images were made using precondition-based total field inversion. All images were reviewed by a neuroradiologist and a radiology resident. Ten subjects (18%), all with traumatic brain injury, demonstrated blood products on 3D gradient recalled echo imaging. All lesions were visible on preconditioned quantitative susceptibility mapping, while 6 were not visible on mask-based quantitative susceptibility mapping. Thirty-one subjects (55%) demonstrated brain parenchyma and/or lesions that were visible on preconditioned quantitative susceptibility mapping but not on mask-based quantitative susceptibility mapping. Six subjects (11%) demonstrated pons artifacts on preconditioned quantitative susceptibility mapping and mask-based quantitative susceptibility mapping

Survival and clinical outcome of dogs with ischaemic stroke

DEFF Research Database (Denmark)

Gredal, Hanne Birgit; Toft, Nils; Westrup, Ulrik

2013-01-01

The objectives of the present study were to investigate survival time, possible predictors of survival and clinical outcome in dogs with ischaemic stroke. A retrospective study of dogs with a previous diagnosis of ischaemic stroke diagnosed by magnetic resonance imaging (MRI) was performed....... The association between survival and the hypothesised risk factors was examined using univariable exact logistic regression. Survival was examined using Kaplan-Meier and Cox regression. Twenty-two dogs were identified. Five dogs (23%) died within the first 30days of the stroke event. Median survival in 30-day...... survivors was 505days. Four dogs (18%) were still alive by the end of the study. Right-sided lesions posed a significantly increased risk of mortality with a median survival time in dogs with right-sided lesions of 24days vs. 602days in dogs with left sided lesions (P=0.006). Clinical outcome was considered...

Thrombolytic therapy for the treatment of acute ischaemic stroke in adults with homozygous sickle cell disease.

Science.gov (United States)

Majhadi, Loubna; Calvet, David; Rosso, Charlotte; Bartolucci, Pablo

2017-07-28

Stroke is a significant cause of morbidity and mortality in patients with homozygous sickle cell disease (SCD). A specific large-vessel vasculopathy is often responsible for both haemorrhagic and ischaemic strokes in patients with SCD. Although intravenous thrombolysis has been considered as a therapeutic option for acute ischaemic strokes in SCD, its use remains debated because of an increased risk of spontaneous intracranial haemorrhage reported in this disease. This risk of haemorrhage is mainly supported by the presence of a Moyamoya syndrome often associated with the specific vasculopathy in patients with homozygous SCD. We report two cases of patients with homozygous SCD treated with intravenous thrombolysis for an acute ischaemic stroke without haemorrhagic transformation. Our cases suggest that reperfusion strategy in acute ischaemic stroke in patients with homozygous SCD can be considered once associated Moyamoya syndrome has been ruled out. An international registry would be of interest as these situations are rare. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Use of a preconditioned Bi-conjugate gradient method for hybrid plasma stability analysis

International Nuclear Information System (INIS)

Mikic, Z.; Morse, E.C.

1985-01-01

The numerical stability analysis of compact toroidal plasmas using implicit time differencing requires the solution of a set of coupled, 2-dimensional, elliptic partial differential equations for the field quantities at every timestep. When the equations are spatially finite-differenced and written in matrix form, the resulting matrix is large, sparse, complex, non-Hermitian, and indefinite. The use of the preconditioned bi-conjugate gradient method for solving these equations is discussed. The effect of block-diagonal preconditioning and incomplete block-LU preconditionig on the convergence of the method is investigated. For typical matrices arising in our studies, the eigenvalue spectra of the original and preconditioned matrices are calculated as an illustration of the effectiveness of the preconditioning. We show that the preconditioned bi-conjugate gradient method coverages more rapidly than the conjugate gradient method applied to the normal equations, and that it is an effective iterative method for the class of non-Hermitian, indefinite problems of interest

Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring

DEFF Research Database (Denmark)

Horn, J; Naylor, A R; Laman, D M

2005-01-01

Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated.......Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated....

Peripheral ischaemic retinopathy and neovascularisation in a patient with subacute streptococcus mitis-induced bacterial endocarditis.

Science.gov (United States)

Leysen, Laura S; Kreps, Elke O; De Schryver, Ilse; Hoornaert, Kristien P; Smith, Vanessa; De Zaeytijd, Julie

2017-01-01

Objective: To describe a patient with peripheral retinal ischaemia and neovascularisation who was diagnosed with streptococcus mitis-induced bacterial endocarditis. Methods: Retrospective analysis of case report. A 57-year-old man presented with a history of a rapidly progressive, bilateral, painless visual loss. He also suffered from pain in the neck and lower back and a weight loss of 10 kg. He underwent a full ophthalmologic work-up, laboratory investigations, and imaging of the spine. Results: BCVA was reduced to 20/40 in the right eye and 20/32 in the left eye. Fundoscopy showed rare intra-retinal haemorrhages including few Roth spots and cotton wool lesions. Fluorescein angiography demonstrated large areas of peripheral retinal ischaemia and neovascularisation. Imaging of the spine showed spondylodiscitis on several levels. Further imaging and blood cultures confirmed bacterial endocarditis of the mitral valve. Streptococcus mitis was subsequently identified as the causative organism. Conclusion: Peripheral retinal ischaemia and neovascularisation were previously unrecognised as a feature of infectious endocarditis. Therefore, their presence, apart from the classic Roth spots, should prompt the consideration of infectious endocarditis in the etiologic work-up.

Peripheral ischaemic retinopathy and neovascularisation in a patient with subacute streptococcus mitis-induced bacterial endocarditis

Directory of Open Access Journals (Sweden)

Leysen, Laura S.

2017-09-01

Full Text Available Objective: To describe a patient with peripheral retinal ischaemia and neovascularisation who was diagnosed with streptococcus mitis-induced bacterial endocarditis. Methods: Retrospective analysis of case report. A 57-year-old man presented with a history of a rapidly progressive, bilateral, painless visual loss. He also suffered from pain in the neck and lower back and a weight loss of 10 kg. He underwent a full ophthalmologic work-up, laboratory investigations, and imaging of the spine.Results: BCVA was reduced to 20/40 in the right eye and 20/32 in the left eye. Fundoscopy showed rare intra-retinal haemorrhages including few Roth spots and cotton wool lesions. Fluorescein angiography demonstrated large areas of peripheral retinal ischaemia and neovascularisation. Imaging of the spine showed spondylodiscitis on several levels. Further imaging and blood cultures confirmed bacterial endocarditis of the mitral valve. Streptococcus mitis was subsequently identified as the causative organism. Conclusion: Peripheral retinal ischaemia and neovascularisation were previously unrecognised as a feature of infectious endocarditis. Therefore, their presence, apart from the classic Roth spots, should prompt the consideration of infectious endocarditis in the etiologic work-up.

The role of atrial fibrillation on mortality and morbidity in patients with ischaemic stroke

International Nuclear Information System (INIS)

Cogen, E.E.; Tombul, T.; Yildirim, G.; Odabas, F.O.; Sayin, R.

2013-01-01

Objective: To investigate the impact of atrial fibrillation on mortality and morbidity in ischaemic stroke patients. Methods: The retrospective study was conducted at the Neurology Clinic, Faculty of Medicine, Yuzuncu Yil University, Van, Turkey, and comprised records of ischaemic stroke patients hospitalised between January 2006 and September 2009. SPSS 13 was used for statistical analysis. Results: Of the 404 patients in the study, 69 (17.1%) had atrial fibrilation. The mean age of such patients was 66.78+9-12.23 years compared to 61.01+-15.11 years for the rest. Besides 47 (68.1%) of these patients were females. According to the modified Rankin Scale scores, the degree of disability was significantly higher at the time of arrival and discharge, and mortality rates were significantly higher also (p<0.01). Conclusion: Atrial fibrillation affected the prognosis of ischaemic stroke adversely in terms of mortality and morbidity. (author)

The role of atrial fibrillation on mortality and morbidity in patients with ischaemic stroke

International Nuclear Information System (INIS)

Cogen, E.E.; Tmbul, T.; Yildirim, G.; Sayin, R.

2013-01-01

To investigate the impact of atrial fibrillation on mortality and morbidity in ischaemic stroke patients. Methods: The retrospective study was conducted at the Neurology Clinic, Faculty of Medicine, Yuzuncu Yil University, Van, Turkey, and comprised records of ischaemic stroke patients hospitalised between January 2006 and September 2009. SPSS 13 was used for statistical analysis. Results: Of the 404 patients in the study, 69 (17.1%) had atrial fibrilation. The mean age of such patients was 66.78+-12.23 years compared to 61.01+-15.11 years for the rest. Besides 47 (68.1%) of these patients were females. According to the modified Rankin Scale scores, the degree of disability was significantly higher at the time of arrival and discharge, and mortality rates were significantly higher also (p<0.01). Conclusion: Atrial fibrillation affected the prognosis of ischaemic stroke adversely in terms of mortality and morbidity. (author)

effect of dl-carnitine on tissue content of ad eno ine triphospha te

African Journals Online (AJOL)

BSN

values of 16.2 ± 5.2µ mols lg dry weight for ATP and I 1.7± 2.5 ~11nols/g dry weight for CP in normal (non ischaem1c) myocardial tissue. Continuous perfusion of the heans "ith perfusate contaming 4.9µmols/ml. DL-Carnitine appeared to prevent the lowermg of ATP and CP levels as a result of induction of ischaemia.

The diagnostic performance of CT-derived fractional flow reserve for evaluation of myocardial ischaemia confirmed by invasive fractional flow reserve: a meta-analysis

International Nuclear Information System (INIS)

Li, S.; Tang, X.; Peng, L.; Luo, Y.; Dong, R.; Liu, J.

2015-01-01

Aim: To review the literature on the diagnostic accuracy of CT-derived fractional flow reserve (FFR CT ) for the evaluation of myocardial ischaemia in patients with suspected or known coronary artery disease, with invasive fractional flow reserve (FFR) as the reference standard. Materials and methods: A PubMed, EMBASE, and Cochrane cross-search was performed. The pooled diagnostic accuracy of FFR CT , with FFR as the reference standard, was primarily analysed, and then compared with that of CT angiography (CTA). The thresholds to diagnose ischaemia were FFR ≤0.80 or CTA ≥50% stenosis. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Results: Three multicentre studies (NXT Trial, DISCOVER-FLOW study and DeFACTO study) were included, examining 609 patients and 1050 vessels. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR−), and diagnostic odds ratio (DOR) for FFR CT were 89% (85–93%), 71% (65–75%), 70% (65–75%), 90% (85–93%), 3.31 (1.79–6.14), 0.16 (0.11–0.23), and 21.21 (9.15–49.15) at the patient-level, and 83% (78–63%), 78% (75–81%), 61% (56–65%), 92% (89–90%), 4.02 (1.84–8.80), 0.22 (0.13–0.35), and 19.15 (5.73–63.93) at the vessel-level. At per-patient analysis, FFR CT has similar sensitivity but improved specificity, PPV, NPV, LR+, LR−, and DOR versus those of CTA. At per-vessel analysis, FFR CT had a slightly lower sensitivity, similar NPV, but improved specificity, PPV, LR+, LR−, and DOR compared with those of CTA. The area under the summary receiver operating characteristic curves for FFR CT was 0.8909 at patient-level and 0.8865 at vessel-level, versus 0.7402 for CTA at patient-level. Conclusions: FFR CT , which was associated with improved diagnostic accuracy versus CTA, is a viable alternative to FFR for detecting coronary ischaemic lesions

Protective effects of dexrazoxane against acute ischaemia/reperfusion injury of rat hearts

Czech Academy of Sciences Publication Activity Database

Neckář, Jan; Boudíková, Adéla; Mandíková, Petra; Štěrba, M.; Popelová, O.; Mikšík, Ivan; Dabrowská, L.; Mráz, J.; Geršl, V.; Kolář, František

2012-01-01

Roč. 90, č. 9 (2012), s. 1303-1310 ISSN 0008-4212 R&D Projects: GA AV ČR(CZ) IAAX01110901; GA ČR(CZ) GA305/09/0416 Institutional research plan: CEZ:AV0Z50110509 Keywords : heart * dexrazoxane * ischaemia * reperfusion * infarct size * arrhythmias * cardioprotection * reactive oxygen species Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 1.556, year: 2012

Application of streptokinase and PTA in lower limb chronic ischaemia; Zastosowanie streptokinazy i przezskornej angioplastyki w przewleklym niedokrwieniu konczyn dolnych

Energy Technology Data Exchange (ETDEWEB)

Syberyjski, R.; Domanski, Z.; Cyrylowski, L. [Pomorska Akademia Medyczna, Szczecin (Poland)

1994-12-31

In 14 patients with chronic ischaemia of lower limbs, local fibrynolysis with streptokinase followed by PTA was performed in occluded arteries. The procedure was successful in 10 patients. An adverse reaction was observed in 1 patient (gingivorrhea), and a complication was noticed in another one (acute ischaemia due a trombosis). These results suggest that the method may appear as a safe alternative to a surgery treatment, and encourage to evaluate an effectiveness of the procedure in a large group of patients. (author). 6 refs, 3 figs.

The evaluation of cerebral oxygenation by oximetry in patients with ischaemic stroke.

Directory of Open Access Journals (Sweden)

Demet G

2000-04-01

Full Text Available AIMS: To evaluate the clinical significance of estimation of the regional cerebral oxygen saturation (rSO2 in the patients with ischaemic stroke by the cerebral oximetry during acute, sub-acute and chronic phases. SUBJECTS AND METHODS: In this prospective study, 24 patients with ischaemic stroke in the middle cerebral artery territory were included. A detailed clinical examination and appropriate laboratory investigations were carried out. The rSO2 was determined by oximetery (INVOS 3100-SD bilaterally on the first, third, seventh, and fifteenth days. The blood pressure, the peripheral capillary oxygen saturation and the arterial blood gas values were noted too. the changes were evaluated along with Glasgow coma scale (GCS using unpaired student t-test and one way ANOVA test. RESULTS: There were significant differences between the rSO2 values in acute, subacute and chronic phases on the side of the lesion (p value < 0.05. The values of oxygen saturation gradually increased throughout the chronic phase. These values showed a positive correlation with GCS, but the results were not significant statistically. The rSO2 values were also significantly higher on the non-lesional side than those on the lesion side in the acute phase (p= 0.0034, the discrepancy disappeared during the sub-acute and chronic phases. CONCLUSION: Cerebral oximetry can be used as a measure to evaluate the cerebral oxygenation during the various phases of ischaemic stroke. It has a potential to serve as a useful marker for detection of cerebral oxygenation imbalances, to judge the effectiveness of the management and for the follow-up of patients with ischaemic stroke.

The concept of anaesthetic-induced cardioprotection: clinical relevance

NARCIS (Netherlands)

de Hert, Stefan G.

2005-01-01

Experimental evidence has clearly demonstrated that volatile anaesthetic agents have direct protective properties against reversible and irreversible ischaemic myocardial damage. These properties have been related to a direct preconditioning effect but also to an effect on the extent of reperfusion

Sensory Preconditioning in Newborn Rabbits: From Common to Distinct Odor Memories

Science.gov (United States)

Coureaud, Gerard; Tourat, Audrey; Ferreira, Guillaume

2013-01-01

This study evaluated whether olfactory preconditioning is functional in newborn rabbits and based on joined or independent memory of odorants. First, after exposure to odorants A+B, the conditioning of A led to high responsiveness to odorant B. Second, responsiveness to B persisted after amnesia of A. Third, preconditioning was also functional…

Is clopidogrel superior to aspirin in secondary prevention of vascular disease?

Directory of Open Access Journals (Sweden)

Algra Ale

2000-11-01

Full Text Available Abstract The cornerstone in clinical evidence of the relative efficacy of thienopyridines (clopidogrel, ticlopidine versus aspirin in the secondary prevention of vascular disease is the Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events trial. This trial showed a modest benefit in the reduction of vascular events by clopidogrel. The results differed according to qualifying disorder: myocardial infarction, -3.7%; ischaemic stroke, +7.3%; and peripheral arterial disease, +23.8% (P = 0.042. Similar results were found for ticlopidine after brain ischaemia. The safety of clopidogrel appears to be similar to that of aspirin and better than that of ticlopidine. However, the recent report of thrombotic thrombocytopenic purpura in association with clopidogrel causes concern.

Extended normothermic extracorporeal perfusion of isolated human liver after warm ischaemia: a preliminary report.

Science.gov (United States)

Bellomo, Rinaldo; Marino, Bruno; Starkey, Graeme; Fink, Michael; Wang, Bao Zhong; Eastwood, Glenn M; Peck, Leah; Young, Helen; Houston, Shane; Skene, Alison; Opdam, Helen; Jones, Robert

2014-09-01

Donation after circulatory death (DCD) livers are at markedly increased risk of primary graft dysfunction and biliary tract ischaemia. Normothermic extracorporeal liver perfusion (NELP) may increase the ability to transplant DCD livers and may allow their use for artificial extracorporeal liver support of patients with fulminant liver failure. We conducted two proof-of-concept experiments using human livers after DCD to assess the feasibility and functional efficacy of NELP over an extended period. We applied extracorporeal membrane oxygenation, parenteral nutrition, separate hepatic artery and portal vein perfusion and physiological perfusion pressures to two livers obtained after DCD. We achieved NELP and evidence of liver function (bile production, paracetamol removal and maintenance of normal lactate levels) in both livers; one for 24 hours and the other for 43 hours. Histological examination showed areas of patchy ischaemia but preserved biliary ducts and canaliculi. Our experiments justify further investigations of the feasibility and efficacy of extended DCD liver preservation by ex-vivo perfusion.

High spatial resolution free-breathing 3D late gadolinium enhancement cardiac magnetic resonance imaging in ischaemic and non-ischaemic cardiomyopathy: quantitative assessment of scar mass and image quality.

Science.gov (United States)

Bizino, Maurice B; Tao, Qian; Amersfoort, Jacob; Siebelink, Hans-Marc J; van den Bogaard, Pieter J; van der Geest, Rob J; Lamb, Hildo J

2018-04-06

To compare breath-hold (BH) with navigated free-breathing (FB) 3D late gadolinium enhancement cardiac MRI (LGE-CMR) MATERIALS AND METHODS: Fifty-one patients were retrospectively included (34 ischaemic cardiomyopathy, 14 non-ischaemic cardiomyopathy, three discarded). BH and FB 3D phase sensitive inversion recovery sequences were performed at 3T. FB datasets were reformatted into normal resolution (FB-NR, 1.46x1.46x10mm) and high resolution (FB-HR, isotropic 0.91-mm voxels). Scar mass, scar edge sharpness (SES), SNR and CNR were compared using paired-samples t-test, Pearson correlation and Bland-Altman analysis. Scar mass was similar in BH and FB-NR (mean ± SD: 15.5±18.0 g vs. 15.5±16.9 g, p=0.997), with good correlation (r=0.953), and no bias (mean difference ± SD: 0.00±5.47 g). FB-NR significantly overestimated scar mass compared with FB-HR (15.5±16.9 g vs 14.4±15.6 g; p=0.007). FB-NR and FB-HR correlated well (r=0.988), but Bland-Altman demonstrated systematic bias (1.15±2.84 g). SES was similar in BH and FB-NR (p=0.947), but significantly higher in FB-HR than FB-NR (pFB-NR (pFB-HR than FB-NR (p<0.01). Navigated free-breathing 3D LGE-CMR allows reliable scar mass quantification comparable to breath-hold. During free-breathing, spatial resolution can be increased resulting in improved sharpness and reduced scar mass. • Navigated free-breathing 3D late gadolinium enhancement is reliable for myocardial scar quantification. • High-resolution 3D late gadolinium enhancement increases scar sharpness • Ischaemic and non-ischaemic cardiomyopathy patients can be imaged using free-breathing LGE CMR.

The value of serum mean platelet volume in ischaemic stroke patient

International Nuclear Information System (INIS)

Tamer, F.; Fevzi, Y.; Deniz, A.E.; Cemil, K.; Cihat, Y.; Muhittin, Y.; Serkan, Y.M.; Ali, C.M.; Faith, B.

2013-01-01

Objective: To investigate the value of serum Mean Platelet Volume in acute ischaemic stroke patients. Method: The retrospective case-control study was conducted at Ankara Numune Training and Research Hospital in Turkey and comprised record of patients of acute ischaemic stroke admitted to the Emergency Department between June 2010 and January 2012. The two groups were statistically compared using SPSS 18.0. Result: Overall, there were 482 stroke patients (Group 1) and 315 subjects as controls (Group 2). The median value in Group 1 was 9.0 (2.1) (fL), while in Group 2 it was 8.80 (2.4) (fL). The difference was statistically significant (Z=-2.80; p<0.05). Conclusion: Mean Platelet Volume increased in the stroke patients. (author)

Two-level preconditioned conjugate gradient methods with applications to bubbly flow problems

NARCIS (Netherlands)

Tang, J.M.

2008-01-01

The Preconditioned Conjugate Gradient (PCG) method is one of the most popular iterative methods for solving large linear systems with a symmetric and positive semi-definite coefficient matrix. However, if the preconditioned coefficient matrix is ill-conditioned, the convergence of the PCG method

Long term results of polytetrafluoroethylene in above knee femoropopliteal bypass for critical ischaemia.

LENUS (Irish Health Repository)

Kavanagh, E G

2012-02-03

Ninety-six consecutive above-knee femoropopliteal bypasses, using polytetrafluoroethylene (PTFE) preferentially, were performed for limb-threatening ischaemia. Cumulative primary graft patency was 68 per cent, 49 per cent and 36 per cent and limb salvage 93 per cent, 85 per cent and 75 per cent at 1, 3 and 5 yr respectively. As a result of poor long term survival (51 per cent at 5 yr), and the healing of remedial lesions before graft occlusion, 68 patients (72 per cent) required no further intervention. Eighteen secondary bypasses were undertaken, 12 using ipsilateral saphenous vein. In this group of elderly patients with poor life expectancy, where a limited operation is desirable, the use of PTFE provided excellent limb salvage with low morbidity. Although we can no longer justify our continued use of PTFE in every case of critical ischaemia because of its inferior patency to autogenous vein, we continue to use it preferentially in patients whose lifespan is likely to be short and in cases where a remedial lesion is present.

The diagnosis and treatment of non-occlusive gut ischaemia

International Nuclear Information System (INIS)

Schindler, G.; Bruch, H.P.; Wuerzburg Univ.

1991-01-01

Non-occlusive gut ischaemia is a disease of advanced age. Its causes are reduced cardiac output or shock, facilitated by digitalis, adrenaline, ergotamine and diuretics. The persisting microcirculation and development of gut necrois leads to an increase in certain serum enzymes, such as lactate, LDH and CK-NB. The early application of mesenteric angiography using a DSA technique reveals four grades of under-perfusion. Early and correct diagnosis of the disease should lead to intra-arterial treatment with prostaglandin. In 10 out of 42 cases, conservative therapy led to re-perfusion of the gut. (orig.) [de

Nitroglycerine and sodium trioxodinitrate: from the discovery to the preconditioning effect.

Science.gov (United States)

Pagliaro, Pasquale; Gattullo, Donatella; Penna, Claudia

2013-10-01

The history began in the 19th century with Ascanio Sobrero (1812-1888), the discoverer of glycerol trinitrate (nitroglycerine, NTG), and with Angelo Angeli (1864-1931), the discoverer of sodium trioxodinitrate (Angeli's salt). It is likely that Angeli and Sobrero never met, but their two histories will join each other more than a century later. In fact, it has been discovered that both NTG and Angeli's salt are able to induce a preconditioning effect. As NTG has a long history as an antianginal drug its newly discovered property as a preconditioning agent has also been tested in humans. Angeli's salt properties as a preconditioning and inotropic agent have only been tested in animals so far.

Exercise, stress or what. The non-invasive detection of latent coronary artery disease

International Nuclear Information System (INIS)

Coltart, J.; Robinson, P.S.

1978-01-01

This communication discusses the methods of detecting latent coronary artery disease in an entirely asymptomatic individual with no previous symptoms or signs suggestive of coronary artery disease. Isotope techniques are being increasingly employed in the detection and assessment of coronary artery disease in that they may enable the confirmation of the presence of ischaemia, the extent and location of the underlying coronary artery disease and the effect of ischaemia on overall and regional left ventricular function. Three groups of techniques are commonly employed: 1. assessment of myocardial perfusion; 2. labelling of acute myocardial infarction; 3. overall and regional left ventricular function studies. Isotopes of potassium were initially studied, and, despite technical problems with imaging, 43 K has proved a useful agent in that over a range of coronary flow rates from normal to severely reduced flow, myocardial uptake parallels myocardial blood flow. Myocardial perfusion imaging should enhance the sensitivity and specificity of exercise testing in the symptomatic population and should also be helpful in the asymptomatic population although data on such populations are as yet extremely limited. Acute infarct labelling has little relevance to the very early detection of coronary artery disease. Assessment of overall and regional left ventricular function using gated blood pool scanning at rest and possibly also during exercise has potentially very wide applications in ischaemic heart disease and in combination with myocardial perfusion scanning in the assessment of symptomatic ischaemic heart disease and the detection of ischaemia and coronary artery disease in the asymptomatic population. (Auth.)

123I-BMIPP fatty acid analogue imaging is a novel diagnostic and prognostic approach following acute myocardial infarction.

Science.gov (United States)

Biswas, S K; Sarai, M; Hishida, H; Ozaki, Y

2009-10-01

Fatty acid oxidation is the most efficient mode of myocardial energy production which requires a large amount of oxygen. Thus, alteration of fatty acid oxidation is considered to be a sensitive marker of ischaemia and myocardial damage. (123)I-BMIPP ([123]I-beta-methyl-p-iodophenylpentadecanoic acid) is a newly-investigated single-photon branching free fatty acid radiopharmaceutical with slow metabolism; thus, it is well-suited for single-photon emission computed tomography (SPECT). Assessment of fatty acid metabolism by radionuclide techniques has a potential role for the early detection of myocardial ischaemia and the assessment of the severity of ischaemic heart disease. Although stable patients with a healed myocardial infarction may have a relatively good prognosis, risk stratification in the predischarge period should be valuable for deciding upon appropriate management. In this respect, the presence of discordant BMIPP uptake relative to (201)Tl perfusion appears to be the best predictor of future cardiac events among all other cardiovascular imaging modalities. Since discordant BMIPP uptake correlates well with redistribution on stress (201)Tl imaging and perfusion-metabolism mismatch on positron emission tomography, it is considered that such BMIPP and (201)Tl discordance may identify a high-risk subgroup among patients with acute myocardial infarction. A BMIPP scan may reflect prior severe ischaemia after recovery of perfusion, the so-called "ischaemic memory". Gated BMIPP SPECT has been recently introduced for simultaneous assessment of myocardial metabolism and ventricular function. Such a new technique seems to be valuable for a better understanding of the pathophysiological state of heart failure and cardiomyopathy.

Priming of the Cells: Hypoxic Preconditioning for Stem Cell Therapy.

Science.gov (United States)

Wei, Zheng Z; Zhu, Yan-Bing; Zhang, James Y; McCrary, Myles R; Wang, Song; Zhang, Yong-Bo; Yu, Shan-Ping; Wei, Ling

2017-10-05

Stem cell-based therapies are promising in regenerative medicine for protecting and repairing damaged brain tissues after injury or in the context of chronic diseases. Hypoxia can induce physiological and pathological responses. A hypoxic insult might act as a double-edged sword, it induces cell death and brain damage, but on the other hand, sublethal hypoxia can trigger an adaptation response called hypoxic preconditioning or hypoxic tolerance that is of immense importance for the survival of cells and tissues. This review was based on articles published in PubMed databases up to August 16, 2017, with the following keywords: "stem cells," "hypoxic preconditioning," "ischemic preconditioning," and "cell transplantation." Original articles and critical reviews on the topics were selected. Hypoxic preconditioning has been investigated as a primary endogenous protective mechanism and possible treatment against ischemic injuries. Many cellular and molecular mechanisms underlying the protective effects of hypoxic preconditioning have been identified. In cell transplantation therapy, hypoxic pretreatment of stem cells and neural progenitors markedly increases the survival and regenerative capabilities of these cells in the host environment, leading to enhanced therapeutic effects in various disease models. Regenerative treatments can mobilize endogenous stem cells for neurogenesis and angiogenesis in the adult brain. Furthermore, transplantation of stem cells/neural progenitors achieves therapeutic benefits via cell replacement and/or increased trophic support. Combinatorial approaches of cell-based therapy with additional strategies such as neuroprotective protocols, anti-inflammatory treatment, and rehabilitation therapy can significantly improve therapeutic benefits. In this review, we will discuss the recent progress regarding cell types and applications in regenerative medicine as well as future applications.

Pharmacological preconditioning with GYKI 52466: a prophylactic approach to neuroprotection

Directory of Open Access Journals (Sweden)

Chelsea S Goulton

2010-08-01

Full Text Available Some toxins and drugs can trigger lasting neuroprotective mechanisms that enable neurons to resist a subsequent severe insult. This ‘pharmacological preconditioning’ has far-reaching implications for conditions in which blood flow to the brain is interrupted. We have previously shown that in vitro preconditioning with the AMPA receptor antagonist GYKI 52466 induces tolerance to kainic acid (KA toxicity in hippocampus. This effect persists well after washout of the drug and may be mediated via inverse agonism of G protein linked receptors. Given the amplifying nature of metabotropic modulation, we hypothesised that GYKI 52466 may be effective in reducing seizure severity at doses well below those normally associated with adverse side effects. Here we report that pharmacological preconditioning with low-dose GYKI imparts a significant protection against KA-induced seizures in vivo. GYKI (3 mg/kg, s.c., 90 to 180 min. prior to high-dose KA, markedly reduced seizure scores, virtually abolished all level 3 and level 4 seizures, and completely suppressed KA-induced hippocampal cFOS expression. In addition, preconditioned animals exhibited significant reductions in high frequency/high amplitude spiking and ECoG power in the delta, theta, alpha and beta bands during KA. Adverse behaviours often associated with higher doses of GYKI were not evident during preconditioning. The fact that GYKI is effective at doses well-below, and at pre-administration intervals well-beyond previous studies, suggests that a classical blockade of ionotropic AMPA receptors does not underlie anticonvulsant effects. Low-dose GYKI preconditioning may represent a novel, prophylactic strategy for neuroprotection in a field almost completely devoid of effective pharmaceuticals.

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

Energy Technology Data Exchange (ETDEWEB)

Bakkal, B.H. [Department of Radiation Oncology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Gultekin, F.A. [Department of General Surgery, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Guven, B. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Turkcu, U.O. [Mugla School of Health Sciences, Mugla Sitki Kocman University, Mugla (Turkey); Bektas, S. [Department of Pathology, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey); Can, M. [Department of Biochemistry, School of Medicine, Bulent Ecevit University, Kozlu, Zonguldak (Turkey)

2013-09-27

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage.

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

International Nuclear Information System (INIS)

Bakkal, B.H.; Gultekin, F.A.; Guven, B.; Turkcu, U.O.; Bektas, S.; Can, M.

2013-01-01

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage

The effects of levosimendan on brain metabolism during initial recovery from global transient ischaemia/hypoxia

Directory of Open Access Journals (Sweden)

Roehl Anna B

2012-08-01

Full Text Available Abstract Backround Neuroprotective strategies after cardiopulmonary resuscitation are currently the focus of experimental and clinical research. Levosimendan has been proposed as a promising drug candidate because of its cardioprotective properties, improved haemodynamic effects in vivo and reduced traumatic brain injury in vitro. The effects of levosimendan on brain metabolism during and after ischaemia/hypoxia are unknown. Methods Transient cerebral ischaemia/hypoxia was induced in 30 male Wistar rats by bilateral common carotid artery clamping for 15 min and concomitant ventilation with 6% O2 during general anaesthesia with urethane. After 10 min of global ischaemia/hypoxia, the rats were treated with an i.v. bolus of 24 μg kg-1 levosimendan followed by a continuous infusion of 0.2 μg kg-1 min-1. The changes in the energy-related metabolites lactate, the lactate/pyruvate ratio, glucose and glutamate were monitored by microdialysis. In addition, the effects on global haemodynamics, cerebral perfusion and autoregulation, oedema and expression of proinflammatory genes in the neocortex were assessed. Results Levosimendan reduced blood pressure during initial reperfusion (72 ± 14 vs. 109 ± 2 mmHg, p = 0.03 and delayed flow maximum by 5 minutes (p = 0.002. Whereas no effects on time course of lactate, glucose, pyruvate and glutamate concentrations in the dialysate could be observed, the lactate/pyruvate ratio during initial reperfusion (144 ± 31 vs. 77 ± 8, p = 0.017 and the glutamate release during 90 minutes of reperfusion (75 ± 19 vs. 24 ± 28 μmol·L-1 were higher in the levosimendan group. The increased expression of IL-6, IL-1ß TNFα and ICAM-1, extend of cerebral edema and cerebral autoregulation was not influenced by levosimendan. Conclusion Although levosimendan has neuroprotective actions in vitro and on the spinal cord in vivo and has been shown to cross the blood–brain barrier, the present

A subspace preconditioning algorithm for eigenvector/eigenvalue computation

Energy Technology Data Exchange (ETDEWEB)

Bramble, J.H.; Knyazev, A.V.; Pasciak, J.E.

1996-12-31

We consider the problem of computing a modest number of the smallest eigenvalues along with orthogonal bases for the corresponding eigen-spaces of a symmetric positive definite matrix. In our applications, the dimension of a matrix is large and the cost of its inverting is prohibitive. In this paper, we shall develop an effective parallelizable technique for computing these eigenvalues and eigenvectors utilizing subspace iteration and preconditioning. Estimates will be provided which show that the preconditioned method converges linearly and uniformly in the matrix dimension when used with a uniform preconditioner under the assumption that the approximating subspace is close enough to the span of desired eigenvectors.

Effects of vacuum compression therapy on skin microcirculation in patients suffering from lower limb ischaemia

NARCIS (Netherlands)

Ubbink, D. T.; van der Oord, B. M.; Sobotka, M. R.; Jacobs, M. J.

2000-01-01

We investigated the short-term effect of vacuum compression (VC) treatment on skin microcirculatory perfusion in the foot of patients with lower limb ischaemia and healthy controls. Ten patients with intermittent claudication or rest pain and 5 healthy controls underwent vacuum-compression treatment

An integrative literature review to examine the provision of self-management support following transient ischaemic attack.

Science.gov (United States)

Kessler, Dorothy; Liddy, Clare

2017-11-01

To identify the types of self-management support that have been provided to persons with transient ischaemic attack and the evidence for the effectiveness of these programmes. Self-management is a key element for the effective management of chronic conditions. For persons with transient ischaemic attack, secondary stroke prevention is a recognised standard of care. Best practice guidelines indicate that persons who have experienced transient ischaemic attack should be supported to develop self-management skills. However, it is not clear how best to support the development of these skills. An integrative literature review was conducted. A search was conducted using Medline, Embase, HealthSTAR, CINAHL and PsycINFO. Published quantitative and qualitative studies, abstracts or dissertations describing the provision, experience or outcomes of self-management interventions for people with transient ischaemic attack, and published in English before March 2016, were included. Articles were selected and rated separately by two reviewers. The American Academy for Cerebral Palsy and Developmental Medicine Level of Evidence and Conduct Rating tools were used for rating. Interventions were described and compared, and evidence was presented using the traffic lighting system. Sixteen interventions representing a variety of group- and individual-based interventions were identified. Interventions differed in target population, content, structure, duration and outcomes. Only four interventions were specifically designed for persons with transient ischaemic attack. While evidence to support self-management interventions is promising, there is limited evidence to support any one intervention. However, one good-quality randomised controlled trial supports the provision of a group self-management programme for improving blood pressure control. There are numerous interventions to support self-management by persons with transient ischaemic attack. More research is needed to determine

Time-domain full waveform inversion using the gradient preconditioning based on transmitted waves energy

KAUST Repository

Zhang, Xiao-bo

2017-06-01

The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge storage consumption in the gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI), but the accuracy is affected by the energy of reflected waves when strong reflectors are present in velocity model. To address this problem, we propose a gradient preconditioning method, which scales the gradient based on the energy of the “approximated transmitted wavefield” simulated by the nonreflecting acoustic wave equation. The method does not require computing or storing the Hessian matrix or its inverse. Furthermore, it can effectively eliminate the effects caused by geometric diffusion and non-uniformity illumination on gradient. The results of model experiments confirm that the time-domain FWI using the gradient preconditioning based on transmitted waves energy can achieve higher inversion precision for high-velocity body and the deep strata below when compared with using the gradient preconditioning based on seismic waves energy.

Multi-modal assessment of neurovascular coupling during cerebral ischaemia and reperfusion using remote middle cerebral artery occlusion

DEFF Research Database (Denmark)

Sutherland, Brad A; Fordsmann, Jonas C; Martin, Chris

2017-01-01

. Male Wistar rats were subjected to remote middle cerebral artery occlusion, where a long filament was advanced intraluminally through a guide cannula in the common carotid artery. Transcallosal stimulation evoked increases in blood flow, tissue oxygenation and neuronal activity, which were diminished...... that neurovascular dysfunction was not sustained. These data show for the first time that the rat remote middle cerebral artery occlusion model coupled with transcallosal stimulation provides a novel method for continuous assessment of hyperacute neurovascular coupling changes during ischaemia and reperfusion......Hyperacute changes in cerebral blood flow during cerebral ischaemia and reperfusion are important determinants of injury. Cerebral blood flow is regulated by neurovascular coupling, and disruption of neurovascular coupling contributes to brain plasticity and repair problems. However, it is unknown...

Reperfusion Strategies in the Management of Extremity Vascular Injury with Ischaemia

Science.gov (United States)

2012-01-01

28: 1026–1031. 45 Gürke L, Marx A, Sutter PM, Stierli P, Harder F, Heberer M. Function of fast - and slow - twitch rat skeletal muscle following ischemia...influence muscle necrosis, including temperature, muscle fibre type, muscle location and residual blood flow15,16. The earliest effects of limb...Crawford et al.11 reported that in a murine model of limb ischaemia ethyl pyruvate pretreatment resulted in a lower percentage of injured muscle fibres

Effect of sodium nitrite on ischaemia and reperfusion-induced arrhythmias in anaesthetized dogs: is protein S-nitrosylation involved?

Directory of Open Access Journals (Sweden)

Mária Kovács

Full Text Available To provide evidence for the protective role of inorganic nitrite against acute ischaemia and reperfusion-induced ventricular arrhythmias in a large animal model.Dogs, anaesthetized with chloralose and urethane, were administered intravenously with sodium nitrite (0.2 µmol kg(-1 min(-1 in two protocols. In protocol 1 nitrite was infused 10 min prior to and during a 25 min occlusion of the left anterior descending (LAD coronary artery (NaNO2-PO; n = 14, whereas in protocol 2 the infusion was started 10 min prior to reperfusion of the occluded vessel (NaNO2-PR; n = 12. Control dogs (n = 15 were infused with saline and subjected to the same period of ischaemia and reperfusion. Severities of ischaemia and ventricular arrhythmias, as well as changes in plasma nitrate/nitrite (NOx levels in the coronary sinus blood, were assessed throughout the experiment. Myocardial superoxide and nitrotyrosine (NT levels were determined during reperfusion. Changes in protein S-nitrosylation (SNO and S-glutathionylation were also examined.Compared with controls, sodium nitrite administered either pre-occlusion or pre-reperfusion markedly suppressed the number and severity of ventricular arrhythmias during occlusion and increased survival (0% vs. 50 and 92% upon reperfusion. There were also significant decreases in superoxide and NT levels in the nitrite treated dogs. Compared with controls, increased SNO was found only in NaNO2-PR dogs, whereas S-glutathionylation occurred primarily in NaNO2-PO dogs.Intravenous infusion of nitrite profoundly reduced the severity of ventricular arrhythmias resulting from acute ischaemia and reperfusion in anaesthetized dogs. This effect, among several others, may result from an NO-mediated reduction in oxidative stress, perhaps through protein SNO and/or S-glutathionylation.

Effects of Ischemic Preconditioning of Different Intraoperative Ischemic Times of Vascularized Bone Graft Rabbit Models

Directory of Open Access Journals (Sweden)

Ahmad Sukari Halim

2013-11-01

Full Text Available BackgroundIschemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published.MethodsSixteen rabbits were divided into four groups with ischemic times of 2, 6, 14, and 18 hours. Half of the rabbits in each group underwent ischemic preconditioning. The osteomyocutaneous flaps consisted of the tibia bone, from which the overlying muscle and skin were raised. The technique of ischemic preconditioning involved applying a vascular clamp to the pedicle for 3 cycles of 10 minutes each. The rabbits then underwent serial plain radiography and computed tomography imaging on the first, second, fourth, and sixth postoperative weeks. Following this, all of the rabbits were sacrificed and histological examinations were performed.ResultsThe results showed that for clinical analysis of the skin flaps and bone grafts, the preconditioned groups showed better survivability. In the plain radiographs, except for two non-preconditioned rabbits with intraoperative ischemic times of 6 hours, all began to show early callus formation at the fourth week. The computed tomography findings showed more callus formation in the preconditioned groups for all of the ischemic times except for the 18-hour group. The histological findings correlated with the radiological findings. There was no statistical significance in the difference between the two groups.ConclusionsIn conclusion, ischemic preconditioning improved the survivability of skin flaps and increased callus formation during the healing process of vascularized bone grafts.

Predicting the effect of prevention of ischaemic heart disease

DEFF Research Database (Denmark)

Brønnum-Hansen, Henrik

2002-01-01

Priority setting in public health policy must be based on information on the effectiveness of alternative preventive and therapeutic interventions. The purpose of this study is to predict the effect on mortality from ischaemic heart disease (IHD) in Denmark of reduced exposure to the risk factors...... hypertension, hypercholesterolaemia, cigarette smoking, and physical inactivity....

Equivalent operator preconditioning for elliptic problems

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe; Karátson, J.

2009-01-01

Roč. 50, č. 3 (2009), s. 297-380 ISSN 1017-1398 Institutional research plan: CEZ:AV0Z30860518 Keywords : Elliptic problem * Conjugate gradient method * preconditioning * equivalent operators * compact operators Subject RIV: BA - General Mathematics Impact factor: 0.716, year: 2009 http://en.scientificcommons.org/42514649

99Tcm-MIBI single photon emission tomography (SPET) for detecting myocardial ischaemia and necrosis in patients with significant coronary artery disease.

Science.gov (United States)

Sciammarella, M G; Fragasso, G; Gerundini, P; Maffioli, L; Cappelletti, A; Margonato, A; Savi, A; Chierchia, S

1992-12-01

The ability of 99Tcm-methoxyisobutylisonitrile (MIBI) single photon emission tomography (SPET) to detect myocardial ischaemia and necrosis was assessed in 56 patients (45 male, 11 female, aged 55 +/- 5 years), with clinically recognized ischaemic heart disease (IHD). All underwent coronary angiography (CA) and left ventriculography (LV). SPET images were obtained at rest and at peak exercise (Modified Bruce) 90 min after injection of 99Tcm-MIBI (650-850 MBq). Data were acquired in 30 min over 180 degrees (from 45 degrees RAO to 45 degrees LPO) with no correction for attenuation, using a 64 x 64 matrix. The presence of persistent (P) or reversible (R) perfusion defects (PD) was then correlated to the resting and exercise ECG and to the results of CA and LV. Of the 56 patients, 34 had reversible underperfusion (RPD), 46 persistent underperfusion (PPD) and 31 had both. The occurrence of RPD correlated well with the occurrence of exercise-induced ST segment depression and/or angina (27 patients of 34 patients, 79%) and with the presence of significant coronary artery disease (CAD) (33 of 44, 73%). In 45 of 46 patients (98%) PPD corresponded to akinetic or severely hypokinetic segments (LV) usually explored by ECG leads exhibiting diagnostic Q waves (42 of 46 patients, 91%). The scan was normal both at rest and after stress in four of 11 patients with no CAD, and in two of 45 patients with CAD. Finally, an abnormal resting scan was seen in seven of 11 patients with normal coronary arteries, of whom six had regional wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchogenic adenocarcinoma presenting as a synchronous solitary lytic skull lesion with ischaemic stroke--case report and literature review.

LENUS (Irish Health Repository)

O'Connell, David

2011-01-01

The authors describe a rare case of metastatic bronchogenic adenocarcinoma in a 55-year-old man presenting with concomittant solitary lytic skull lesion and ischaemic stroke. Metastatic bronchogenic carcinoma is known to present as lytic skull lesions. Primary brain tumours are also known to cause ischaemic brain injury. An underlying stroke risk may be exagerated by cranial tumour surgery. Patients with brain tumours are well known to be predisposed to an increased risk of developing thromboembolic disease. It is unusual to see metastatic bronchogenic adenocarcinoma presenting as ischaemic stroke with a background of concomittant cerebral metastasis. The aetio-pathogenesis of this rare occurrence is discussed with a review of literature.

Interleukin-6 is increased in plasma and cerebrospinal fluid of community-dwelling domestic dogs with acute ischaemic stroke

DEFF Research Database (Denmark)

Gredal, Hanne; Thomsen, Barbara B; Boza-Serrano, Antonio

2017-01-01

and cerebrospinal fluid (CSF) in dogs with acute ischaemic stroke and to search for correlations between infarct volume and cytokine concentrations. Blood and CSF were collected from dogs less than 72 h after a spontaneous ischaemic stroke. Infarct volumes were estimated on MRIs. Interleukin (IL)-2, IL-6, IL-8, IL...

Activated protein C attenuates acute ischaemia reperfusion injury in skeletal muscle.

LENUS (Irish Health Repository)

Dillon, J P

2012-02-03

Activated protein C (APC) is an endogenous anti-coagulant with anti-inflammatory properties. The purpose of the present study was to evaluate the effects of activated protein C in the setting of skeletal muscle ischaemia reperfusion injury (IRI). IRI was induced in rats by applying rubber bands above the levels of the greater trochanters bilaterally for a period of 2h followed by 12h reperfusion. Treatment groups received either equal volumes of normal saline or activated protein C prior to tourniquet release. Following 12h reperfusion, muscle function was assessed electrophysiologically by electrical field stimulation. The animals were then sacrificed and skeletal muscle harvested for evaluation. Activated protein C significantly attenuated skeletal muscle reperfusion injury as shown by reduced myeloperoxidase content, wet to dry ratio and electrical properties of skeletal muscle. Further in vitro work was carried out on neutrophils isolated from healthy volunteers to determine the direct effect of APC on neutrophil function. The effects of APC on TNF-alpha stimulated neutrophils were examined by measuring CD18 expression as well as reactive oxygen species generation. The in vitro work demonstrated a reduction in CD18 expression and reactive oxygen species generation. We conclude that activated protein C may have a protective role in the setting of skeletal muscle ischaemia reperfusion injury and that this is in part mediated by a direct inhibitory effect on neutrophil activation.

Preconditioning the modified conjugate gradient method ...

African Journals Online (AJOL)

In this paper, the convergence analysis of the conventional conjugate Gradient method was reviewed. And the convergence analysis of the modified conjugate Gradient method was analysed with our extension on preconditioning the algorithm. Convergence of the algorithm is a function of the condition number of M-1A.

The role of adenosine in preconditioning by brief pressure overload in rats.

Science.gov (United States)

Huang, Cheng-Hsiung; Tsai, Shen-Kou; Chiang, Shu-Chiung; Lai, Chang-Chi; Weng, Zen-Chung

2015-08-01

Brief pressure overload of the left ventricle reduced myocardial infarct (MI) size in rabbits has been previously reported. Its effects in other species are not known. This study investigates effects of pressure overload and the role of adenosine in rats in this study. MI was induced by 40-minute occlusion of the left anterior descending coronary artery followed by 3-hour reperfusion. MI size was determined by triphenyl tetrazolium chloride staining. Brief pressure overload was induced by two 10-minute episodes of partial snaring of the ascending aorta. Systolic left ventricular pressure was raised 50% above the baseline value. Ischemic preconditioning was elicited by two 10-minute coronary artery occlusions. The MI size (mean ± standard deviation), expressed as percentage of area at risk, was significantly reduced in the pressure overload group as well as in the ischemic preconditioning group (17.4 ± 3.0% and 18.2 ± 1.5% vs. 26.6 ± 2.4% in the control group, p overload and ischemic preconditioning (18.3 ± 1.5% and 18.2 ± 2.0%, respectively, p overload of the left ventricle preconditioned rat myocardium against infarction. Because SPT did not significantly alter MI size reduction, our results did not support a role of adenosine in preconditioning by pressure overload in rats. Copyright © 2013. Published by Elsevier B.V.

Ketamine, but not S(+)-ketamine, blocks ischemic preconditioning in rabbit hearts in vivo

NARCIS (Netherlands)

Müllenheim, J.; Frässdorf, J.; Preckel, B.; Thämer, V.; Schlack, W.

2001-01-01

BACKGROUND: Ketamine blocks KATP channels in isolated cells and abolishes the cardioprotective effect of ischemic preconditioning in vitro. The authors investigated the effects of ketamine and S(+)-ketamine on ischemic preconditioning in the rabbit heart in vivo. METHODS: In 46

Correlation between homocysteine and dyslipidemia in ischaemic stroke patients with and without hypertension

Science.gov (United States)

Aria Arina, Cut; Amir, Darwin; Siregar, Yahwardiah; Sembiring, Rosita J.

2018-03-01

Almost 80% of strokes are ischaemic and stroke is the third most common cause of death in developed countries, . The treatment of stroke still limited, the best approach to reduce mortality and morbidity is primary prevention through modification of acquired risk factors. Hypertension and dyslipidemia are one of the major risk factor for stroke while homocysteine is a less well-documented risk factor. The purpose of this study was to know the correlation between homocysteine and dyslipidemia in ischaemic stroke patients with and without hypertension. This study is a cross sectional study; the sample were taken consecutively. All sample matched with inclusion and exclusion criteria, demography data and blood sample were taken. Demography data was analyzed using descriptive statistic, to analyze the relation, we used Chi-Square test. p value dyslipidemia was found in 60 patients. There is a significant relation between homocysteine and dyslipidemia in ischaemic stroke patients with hypertension, p value = 0,009. A significant correlation between homocysteine and dyslipidemia might be because both of them have an important role in the acceleration of the atherosclerotic formation by activation platelet and thrombus, but we still need further study to get more explanation about the relation.

Protective agents used as additives in University of Wisconsin solution to promote protection against ischaemia-reperfusion injury in rat lung.

Science.gov (United States)

Chiang, C H; Wu, K; Yu, C P; Perng, W C; Yan, H C; Wu, C P; Chang, D M; Hsu, K

1998-09-01

1. An intervention to reduce ischaemia-reperfusion lung injury will be an important advance in transplant medicine. Although the mechanisms associated with producing ischaemia-reperfusion endothelial injury have not been completely elucidated, many of the injury mediators have been studied in detail. While no single pharmacological therapy is likely to be totally effective in eliminating this complex injury, we have developed a mixture of agents that are known to block pathways involved in producing ischaemia-reperfusion-associated lung vascular injury.2. The present study modified University of Wisconsin solution (UW) by adding one of the protective agents prostaglandin E1 (PGE1), dexamethasone (Dex) or dibutyryl cAMP (Bt2-cAMP), or a combination of these, to the perfusate of rat lungs exposed to 4 h of cold ischaemia followed by 1 h of reperfusion. Nine modified UW solutions were studied: (1) UW+Dex, (2) UW+PGE1, (3) UW+Bt2-cAMP, (4) UW+Dexx3, (5) UW+PGE1x3, (6) UW+Bt2-cAMPx3, (7) UW+Dex+PGE1, (8) UW+Dex+Bt2-cAMP, (9) UW+PGE1+Bt2-cAMP. These solutions were utilized in individual experiments to assess haemodynamic changes, lung weight gain, the capillary filtration coefficient (Kfc) and pathology in all lungs.3. The results indicate that lung weight gain and Kfc values were significantly lower than with UW alone in groups 1, 2 and 3, which contained only one additional protective agent. In groups 4, 5 and 6, which contain three times the concentration of each protective agent, both Kfc and lung weight gain were similar to those measured in groups 1, 2 and 3, i.e. lungs were protected but the protection was not dose dependent. In groups 7, 8 and 9, which contained two protective agents, lung weight gain and Kfc were greatly reduced compared with UW alone. Histopathological studies showed similar decreases in the injury profiles of lungs.4. Although UW contains several antioxidant protective agents such as allopurinol and glutathione, it did not provide effective

Combined incomplete LU and strongly implicit procedure preconditioning

Energy Technology Data Exchange (ETDEWEB)

Meese, E.A. [Univ. of Trondheim (Norway)

1996-12-31

For the solution of large sparse linear systems of equations, the Krylov-subspace methods have gained great merit. Their efficiency are, however, largely dependent upon preconditioning of the equation-system. A family of matrix factorisations often used for preconditioning, is obtained from a truncated Gaussian elimination, ILU(p). Less common, supposedly due to it`s restriction to certain sparsity patterns, is factorisations generated by the strongly implicit procedure (SIP). The ideas from ILU(p) and SIP are used in this paper to construct a generalized strongly implicit procedure, applicable to matrices with any sparsity pattern. The new algorithm has been run on some test equations, and efficiency improvements over ILU(p) was found.

Mast cells, peptides and cardioprotection - an unlikely marriage?

LENUS (Irish Health Repository)

Walsh, S K

2012-01-31

1 Mast cells have classically been regarded as the \\'bad guys\\' in the setting of acute myocardial ischaemia, where their released contents are believed to contribute both to tissue injury and electrical disturbances resulting from ischaemia. Recent evidence suggests, however, that if mast cell degranulation occurs in advance of ischaemia onset, this may be cardioprotective by virtue of the depletion of mast cell contents that can no longer act as instruments of injury when the tissue becomes ischaemic. 2 Many peptides, such as ET-1, adrenomedullin, relaxin and atrial natriuretic peptide, have been demonstrated to be cardioprotective when given prior to the onset of myocardial ischaemia, although their physiological functions are varied and the mechanisms of their cardioprotective actions appear to be diverse and often ill defined. However, one common denominator that is emerging is the ability of these peptides to modulate mast cell degranulation, raising the possibility that peptide-induced mast cell degranulation or stabilization may hold the key to a common mechanism of their cardioprotection. 3 The aim of this review was to consolidate the evidence implying that mast cell degranulation could play both a detrimental and protective role in myocardial ischaemia, depending upon when it occurs, and that this may underlie the cardioprotective effects of a range of diverse peptides that exerts physiological effects within the cardiovascular system.

S2SA preconditioning for the Sn equations with strictly non negative spatial discretization

International Nuclear Information System (INIS)

Bruss, D. E.; Morel, J. E.; Ragusa, J. C.

2013-01-01

Preconditioners based upon sweeps and diffusion-synthetic acceleration have been constructed and applied to the zeroth and first spatial moments of the 1-D S n transport equation using a strictly non negative nonlinear spatial closure. Linear and nonlinear preconditioners have been analyzed. The effectiveness of various combinations of these preconditioners are compared. In one dimension, nonlinear sweep preconditioning is shown to be superior to linear sweep preconditioning, and DSA preconditioning using nonlinear sweeps in conjunction with a linear diffusion equation is found to be essentially equivalent to nonlinear sweeps in conjunction with a nonlinear diffusion equation. The ability to use a linear diffusion equation has important implications for preconditioning the S n equations with a strictly non negative spatial discretization in multiple dimensions. (authors)

Reducing Haemorrhagic Transformation after Thrombolysis for Stroke: A Strategy Utilising Minocycline

Directory of Open Access Journals (Sweden)

David J. Blacker

2013-01-01

Full Text Available Haemorrhagic transformation (HT of recently ischaemic brain is a feared complication of thrombolytic therapy that may be caused or compounded by ischaemia-induced activation of matrix metalloproteinases (MMPs. The tetracycline antibiotic minocycline inhibits matrix MMPs and reduces macroscopic HT in rodents with stroke treated with tissue plasminogen activator (tPA. The West Australian Intravenous Minocycline and TPA Stroke Study (WAIMATSS aims to determine the safety and efficacy of adding minocycline to tPA in acute ischaemic stroke. The WAIMATSS is a multicentre, prospective, and randomised pilot study of intravenous minocycline, 200 mg 12 hourly for 5 doses, compared with standard care, in patients with ischaemic stroke treated with intravenous tPA. The primary endpoint is HT diagnosed by brain CT and MRI. Secondary endpoints include clinical outcome measures. Some illustrative cases from the early recruitment phase of this study will be presented, and future perspectives will be discussed.

Performance of highly sensitive cardiac troponin T assay to detect ischaemia at PET-CT in low-risk patients with acute coronary syndrome: a prospective observational study.

Science.gov (United States)

Morawiec, Beata; Fournier, Stephane; Tapponnier, Maxime; Prior, John O; Monney, Pierre; Dunet, Vincent; Lauriers, Nathalie; Recordon, Frederique; Trana, Catalina; Iglesias, Juan-Fernando; Kawecki, Damian; Boulat, Olivier; Bardy, Daniel; Lamsidri, Sabine; Eeckhout, Eric; Hugli, Olivier; Muller, Olivier

2017-07-10

Highly sensitive troponin T (hs-TnT) assay has improved clinical decision-making for patients admitted with chest pain. However, this assay's performance in detecting myocardial ischaemia in a lowrisk population has been poorly documented. To assess hs-TnT assay's performance to detect myocardial ischaemia at positron emission tomography/CT (PET-CT) in low-risk patients admitted with chest pain. Patients admitted for chest pain with a nonconclusive ECG and negative standard cardiac troponin T results at admission and after 6 hours were prospectively enrolled. Their hs-TnT samples were at T0, T2 and T6. Physicians were blinded to hs-TnT results. All patients underwent a PET-CT at rest and during adenosine-induced stress. All patients with a positive PET-CT result underwent a coronary angiography. Forty-eight patients were included. Six had ischaemia at PET-CT. All of them had ≥1 significant stenosis at coronary angiography. Areas under the curve (95% CI) for predicting significant ischaemia at PET-CT using hs-TnT were 0.764 (0.515 to 1.000) at T0, 0.812(0.616 to 1.000) at T2 and 0.813(0.638 to 0.989) at T6. The receiver operating characteristicbased optimal cut-off value for hs-TnT at T0, T2 and T6 needed to exclude significant ischaemia at PET-CT was <4 ng/L. Using this value, sensitivity, specificity, positive and negative predictive values of hs-TnT to predict significant ischaemia were 83%/38%/16%/94% at T0, 100%/40%/19%/100% at T2 and 100%/43%/20%/100% at T6, respectively. Our findings suggest that in low-risk patients, using the hs-TnT assay with a cut-off value of 4 ng/L demonstrates excellent negative predictive value to exclude myocardial ischaemia detection at PET-CT, at the expense of weak specificity and positive predictive value. ClinicalTrials.gov Identifier: NCT01374607. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly

Stress induced right ventricular dysfunction: An indication of reversible right ventricular ischaemia

International Nuclear Information System (INIS)

Underwood, S.R.; Walton, S.; Emanuel, R.W.; Swanton, R.H.; Campos Costa, D.; Laming, P.J.; Ell, P.J.

1987-01-01

Stress induced changes in left ventricular ejection fraction are widely used in the detection and assessment of coronary artery disease. This study demonstrates that right ventricular dysfunction may also occur, and assesses its significance in terms of coronary artery anatomy. This study involved 14 normal subjects and 26 with coronary artery disease investigated by equilibrium radionuclide ventriculography, at rest and during maximal dynamic exercise. Mean normal resting right ventricular ejection fraction (RVEF) was 0.40 (SD 0.118), and all normal subjects increased RVEF with stress (mean ΔRVEF+0.13 SD 0.099). Mean ΔRVEF in the subjects with coronary artery disease was significantly lower at 0.00 (SD 0.080), but there was overlap between the two groups. The largest falls in RVEF were seen if the right coronary artery was occluded without retrograde filling. In this subgroup with the most severely compromised right ventricular perfusion (nine subjects), RVEF always fell with stress, and mean ΔRVEF was -0.08 (SD 0.050). There was no significant correlation between ΔLVEF and ΔRVEF, implying that the right ventricular dysfunction was due to right ventricular ischaemia, rather than secondary to left ventricular dysfunction. Stress induced right ventricular ischaemia can therefore be detected readily by radionuclide ventriculography. (orig.)

Digital ischaemia during cooling is independently related to nailfold capillaroscopic pattern in patients with Raynaud's phenomenon

NARCIS (Netherlands)

van Roon, Anniek M.; Smit, Andries J.; van Roon, Arie M.; Bootsma, Hendrika; Mulder, Douwe J.

Objective. The aim of the study was to assess the association between plethysmographically measured vasospasms during stepwise cooling and recovery, as an index for digital ischaemia, and nailfold capillaroscopic pattern (NCP) severity in patients with primary or secondary RP, including SSc.

Nuclear medicine methods in the field of studying the mechanisms of delayed phase of myocardial preconditioning

International Nuclear Information System (INIS)

Wang Shuxia

2001-01-01

Ischemic preconditioning is the intrinsic and most potently myocardial protection. Its mechanism is the foundation of rational therapeutic application. Nowadays there are some theories about delayed phase of preconditioning such as nitric oxide hypothesis, free radical mechanisms, protective protein synthesis and opening of ATP-sensitive potassium channels. By incorporation 3 H-leucine, using liquid scintillation counter, the authors know there was protective protein synthesis during preconditioning. SPECT could study the characteristics of preconditioned myocardium in vivo, and PET might further show the metabolism, energy consumption and its relationship to myocardium dysfunction

Intracerebral haemorrhage risk in microbleed-positive ischaemic stroke patients with atrial fibrillation: Preliminary meta-analysis of cohorts and anticoagulation decision schema.

Science.gov (United States)

Charidimou, Andreas; Boulouis, Gregoire; Shams, Sara; Calvet, David; Shoamanesh, Ashkan

2017-07-15

Whether ischaemic stroke patients with atrial fibrillation (AF) and cerebral microbleeds (CMBs) on MRI can be safely anticoagulated is a hotly debated topic. We performed a systematic review and meta-analysis of published aggregate data, to investigate the risk of subsequent intracerebral haemorrhage (ICH) based on CMBs presence in this stroke population, generally considered for oral anticoagulation. We also suggest a decision-making schema for anticoagulation use in this setting. We searched PubMed for relevant observational studies. Random effects models with DerSimonian-Laird weights were used to investigated the association between CMBs presence at baseline MRI and ICH or ischaemic stroke during follow-up. Four studies, with slightly heterogeneous design, including 990 ischaemic stroke patients were pooled in a meta-analysis (crude CMBs prevalence: 25%; 95%CI: 17%-33%). The median follow-up ranged between 17 and 37months. The future symptomatic ICH rate was 1.6% (16/990), while recurrent ischaemic stroke rate was 5.9% (58/990). Baseline CMB presence was associated with increased risk of symptomatic ICH during follow-up compared to patients without CMBs (OR: 4.16; 95%CI: 1.54-11.25; p=0.005). There was no association between CMBs presence and recurrent ischaemic stroke risk. We have shown that the presence of CMBs in cohorts of ischaemic stroke patients, most with AF on warfarin, is associated with a 4-fold increase in subsequent ICH (but not ischaemic stroke) risk (Class III evidence). These pooled estimates are useful for future trials design. We propose a simple data-driven anticoagulation schema which awaits validation and refinement as new prospective data are accumulated. Copyright © 2017 Elsevier B.V. All rights reserved.

Deteriorating ischaemic stroke. cytokines, soluble cytokine receptors, ferritin, systemic blood pressure, body temperature, blood glucose, diabetes, stroke severity, and CT infarction-volume as predictors of deteriorating ischaemic stroke

DEFF Research Database (Denmark)

Christensen, Hanne; Boysen, Gudrun; Johannesen, Helle Hjorth

2002-01-01

Although the causes of neurological deterioration in acute cerebral infarction have not yet been identified, many variables have been associated with deterioration. The aim of this study was to investigate deteriorating ischaemic stroke....

A Hybrid Parallel Preconditioning Algorithm For CFD

Science.gov (United States)

Barth,Timothy J.; Tang, Wei-Pai; Kwak, Dochan (Technical Monitor)

1995-01-01

A new hybrid preconditioning algorithm will be presented which combines the favorable attributes of incomplete lower-upper (ILU) factorization with the favorable attributes of the approximate inverse method recently advocated by numerous researchers. The quality of the preconditioner is adjustable and can be increased at the cost of additional computation while at the same time the storage required is roughly constant and approximately equal to the storage required for the original matrix. In addition, the preconditioning algorithm suggests an efficient and natural parallel implementation with reduced communication. Sample calculations will be presented for the numerical solution of multi-dimensional advection-diffusion equations. The matrix solver has also been embedded into a Newton algorithm for solving the nonlinear Euler and Navier-Stokes equations governing compressible flow. The full paper will show numerous examples in CFD to demonstrate the efficiency and robustness of the method.

Modern treatment of infection and ischaemia to reduce major amputation in the diabetic foot.

Science.gov (United States)

Edmonds, Michael

2013-01-01

Diabetic patients suffer a high rate of amputation. There are two main reasons; infection which can spread rapidly leading to overwhelming tissue destruction and severe peripheral arterial disease. Studies that have stratified patients according to the presence or absence of both peripheral arterial disease and infection have shown significantly worse outcomes in patients with both peripheral arterial disease and infection. There have been two crucial significant advances in diabetic foot care to improve the outlook of these diabetic patients. First, there has been the realisation that diabetic foot patients experience repeated crises from the rapid onset infection and need a special form of easily accessible care within a multidisciplinary diabetic foot service to provide prompt treatment of infection before it progresses to necrosis. Secondly, within such a service, prompt diagnosis of ischaemia and urgent revascularisation has been established as a further important aspect of successful management. The critical factor in saving limbs is making a rapid diagnosis of infection and ischaemia and administering the appropriate treatment early. In this way speedy healing can be achieved and this can prevent patients from needing amputations.

[Management of coronary artery disease in diabetic patients with lower limb critical ischaemia: assessment of operational risk, drug therapy and indications for interventions].

Science.gov (United States)

Dedov, I I; Kalashnikov, V Iu; Terekhin, S A; Melkozerov, K V

2012-01-01

Despite obvious progress in management of diabetes mellitus, the DM-related complications rate remains inadmissibly high. Macroangiopathy is known to rank first amongst complications of diabetes mellitus, and coronary artery disease remains to be the major cause of death. Analysed herein are peculiarities of the clinical course in diabetic patients presenting with coronary artery disease and lower limb critical ischaemia, followed by discussing the issues concerning drug therapy, preoperative examination, and methods of diagnosis in this cohort of patients prior to vascular operations, assessment of the preoperative risk, indications for coronarography and myocardial revascularization. Also presented are the results of the main clinical trials dedicated to preoperative myocardial revascularization, including those in diabetic patients with limb critical ischaemia, and finally highlighting current importance of optimizing approaches to managing and working out algorithms of treatment policy for diabetic patients with a combination of coronary artery disease, diabetes mellitus, and critical limb ischaemia.

Residual myocardial ischaemia in first non-Q versus Q wave infarction: maximal exercise testing and ambulatory ST-segment monitoring

DEFF Research Database (Denmark)

Mickley, H; Pless, P; Nielsen, J R

1993-01-01

the infarction. The prevalence of exercise-induced ischaemic manifestations in the infarct types was similar: chest pain 14% vs 16% and ST-segment depression 54% vs 54%. The ischaemic threshold did not differ either (heart rate at 1 mm of ST-segment depression 120 +/- 27 vs 119 +/- 25 beats.min-1). During early...... in non-Q wave infarction (51%) as compared to Q wave infarction (31%) (P depression on ambulatory recording and exercise testing significantly predicted the development of future angina pectoris, whereas patients at increased risk for subsequent......In a prospective study of 123 consecutive survivors of a first myocardial infarction (43 non-Q wave, 80 Q wave), we determined the total residual ischaemic burden by use of pre-discharge maximal exercise testing and post-discharge 36 h ambulatory ST-segment monitoring initiated 11 +/- 5 days after...

Achieved serum magnesium concentrations and occurrence of delayed cerebral ischaemia and poor outcome in aneurysmal subarachnoid haemorrhage

NARCIS (Netherlands)

Dorhout Mees, Sanne M.; van den Bergh, Walter M.; Algra, Ale; Rinkel, Gabriel J. E.

2007-01-01

BACKGROUND: Magnesium therapy probably reduces the frequency of delayed cerebral ischaemia (DCI) in subarachnoid haemorrhage (SAH) but uncertainty remains about the optimal serum magnesium concentration. We assessed the relationship between serum magnesium concentrations achieved with magnesium

Time-domain full waveform inversion using the gradient preconditioning based on transmitted waves energy

KAUST Repository

Zhang, Xiao-bo; Tan, Jun; Song, Peng; Li, Jin-shan; Xia, Dong-ming; Liu, Zhao-lun

2017-01-01

The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge storage consumption in the gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI), but the accuracy

Research on the Changes to the Lipid/Polymer Membrane Used in the Acidic Bitterness Sensor Caused by Preconditioning

Directory of Open Access Journals (Sweden)

Yuhei Harada

2016-02-01

Full Text Available A taste sensor that uses lipid/polymer membranes can evaluate aftertastes felt by humans using Change in membrane Potential caused by Adsorption (CPA measurements. The sensor membrane for evaluating bitterness, which is caused by acidic bitter substances such as iso-alpha acid contained in beer, needs an immersion process in monosodium glutamate (MSG solution, called “MSG preconditioning”. However, what happens to the lipid/polymer membrane during MSG preconditioning is not clear. Therefore, we carried out three experiments to investigate the changes in the lipid/polymer membrane caused by the MSG preconditioning, i.e., measurements of the taste sensor, measurements of the amount of the bitterness substance adsorbed onto the membrane and measurements of the contact angle of the membrane surface. The CPA values increased as the preconditioning process progressed, and became stable after 3 d of preconditioning. The response potentials to the reference solution showed the same tendency of the CPA value change during the preconditioning period. The contact angle of the lipid/polymer membrane surface decreased after 7 d of MSG preconditioning; in short, the surface of the lipid/polymer membrane became hydrophilic during MSG preconditioning. The amount of adsorbed iso-alpha acid was increased until 5 d preconditioning, and then it decreased. In this study, we revealed that the CPA values increased with the progress of MSG preconditioning in spite of the decrease of the amount of iso-alpha acid adsorbed onto the lipid/polymer membrane, and it was indicated that the CPA values increase because the sensor sensitivity was improved by the MSG preconditioning.

Predictors for major cardiovascular outcomes in stable ischaemic heart disease (PREMAC)

DEFF Research Database (Denmark)

Winkel, Per; Jakobsen, Janus Christian; Hilden, Jørgen

2017-01-01

The purpose of the predictors for major cardiovascular outcomes in stable ischaemic Heart disease (PREMAC) study is exploratory and hypothesis generating. We want to identify biochemical quantities which—conditionally on the values of available standard demographic, anamnestic, and biochemical data...

Exogenous Gene Transmission of Isocitrate Dehydrogenase 2 Mimics Ischemic Preconditioning Protection.

Science.gov (United States)

Kolb, Alexander L; Corridon, Peter R; Zhang, Shijun; Xu, Weimin; Witzmann, Frank A; Collett, Jason A; Rhodes, George J; Winfree, Seth; Bready, Devin; Pfeffenberger, Zechariah J; Pomerantz, Jeremy M; Hato, Takashi; Nagami, Glenn T; Molitoris, Bruce A; Basile, David P; Atkinson, Simon J; Bacallao, Robert L

2018-04-01

Ischemic preconditioning confers organ-wide protection against subsequent ischemic stress. A substantial body of evidence underscores the importance of mitochondria adaptation as a critical component of cell protection from ischemia. To identify changes in mitochondria protein expression in response to ischemic preconditioning, we isolated mitochondria from ischemic preconditioned kidneys and sham-treated kidneys as a basis for comparison. The proteomic screen identified highly upregulated proteins, including NADP+-dependent isocitrate dehydrogenase 2 (IDH2), and we confirmed the ability of this protein to confer cellular protection from injury in murine S3 proximal tubule cells subjected to hypoxia. To further evaluate the role of IDH2 in cell protection, we performed detailed analysis of the effects of Idh2 gene delivery on kidney susceptibility to ischemia-reperfusion injury. Gene delivery of IDH2 before injury attenuated the injury-induced rise in serum creatinine ( P <0.05) observed in controls and increased the mitochondria membrane potential ( P <0.05), maximal respiratory capacity ( P <0.05), and intracellular ATP levels ( P <0.05) above those in controls. This communication shows that gene delivery of Idh2 can confer organ-wide protection against subsequent ischemia-reperfusion injury and mimics ischemic preconditioning. Copyright © 2018 by the American Society of Nephrology.

Muscle ischaemia associated with NXP2 autoantibodies: a severe subtype of juvenile dermatomyositis.

Science.gov (United States)

Aouizerate, Jessie; De Antonio, Marie; Bader-Meunier, Brigitte; Barnerias, Christine; Bodemer, Christine; Isapof, Arnaud; Quartier, Pierre; Melki, Isabelle; Charuel, Jean-Luc; Bassez, Guillaume; Desguerre, Isabelle; Gherardi, Romain K; Authier, François-Jérôme; Gitiaux, Cyril

2018-05-01

Myositis-specific autoantibodies (MSAs) are increasingly used to delineate distinct subgroups of JDM. The aim of our study was to explore without a priori hypotheses whether MSAs are associated with distinct clinical-pathological changes and severity in a monocentric JDM cohort. Clinical, biological and histological findings from 23 JDM patients were assessed. Twenty-six histopathological parameters were subjected to multivariate analysis. Autoantibodies included anti-NXP2 (9/23), anti-TIF1γ (4/23), anti-MDA5 (2/23), no MSAs (8/23). Multivariate analysis yielded two histopathological clusters. Cluster 1 (n = 11) showed a more severe and ischaemic pattern than cluster 2 (n = 12) assessed by: total score severity ⩾ 20 (100.0% vs 25.0%); visual analogic score ⩾6 (100.0% vs 25.0%); the vascular domain score >1 (100.0% vs 41.7%); microinfarcts (100% vs 58.3%); ischaemic myofibrillary loss (focal punched-out vacuoles) (90.9 vs 25%); and obvious capillary loss (81.8% vs 16.7). Compared with cluster 2, patients in cluster 1 had strikingly more often anti-NXP2 antibodies (7/11 vs 2/12), more pronounced muscle weakness, more gastrointestinal involvement and required more aggressive treatment. Furthermore, patients with anti-NXP2 antibodies, mostly assigned in the first cluster, also displayed more severe muscular disease, requiring more aggressive treatment and having a lower remission rate during the follow-up period. Marked muscle ischaemic involvement and the presence of anti-NXP2 autoantibodies are associated with more severe forms of JDM.

Preconditioned conjugate gradient technique for the analysis of symmetric anisotropic structures

Science.gov (United States)

Noor, Ahmed K.; Peters, Jeanne M.

1987-01-01

An efficient preconditioned conjugate gradient (PCG) technique and a computational procedure are presented for the analysis of symmetric anisotropic structures. The technique is based on selecting the preconditioning matrix as the orthotropic part of the global stiffness matrix of the structure, with all the nonorthotropic terms set equal to zero. This particular choice of the preconditioning matrix results in reducing the size of the analysis model of the anisotropic structure to that of the corresponding orthotropic structure. The similarities between the proposed PCG technique and a reduction technique previously presented by the authors are identified and exploited to generate from the PCG technique direct measures for the sensitivity of the different response quantities to the nonorthotropic (anisotropic) material coefficients of the structure. The effectiveness of the PCG technique is demonstrated by means of a numerical example of an anisotropic cylindrical panel.

Effects of ketamine and its isomers on ischemic preconditioning in the isolated rat heart

NARCIS (Netherlands)

Molojavyi, A.; Preckel, B.; Comfère, T.; Müllenheim, J.; Thämer, V.; Schlack, W.

2001-01-01

BACKGROUND: Ischemic preconditioning protects the heart against subsequent ischemia. Opening of the adenosine triphosphate-sensitive potassium (KATP) channel is a key mechanism of preconditioning. Ketamine blocks KATP channels of isolated cardiomyocytes. The authors investigated the effects of

Field-Split Preconditioned Inexact Newton Algorithms

KAUST Repository

Liu, Lulu

2015-06-02

The multiplicative Schwarz preconditioned inexact Newton (MSPIN) algorithm is presented as a complement to additive Schwarz preconditioned inexact Newton (ASPIN). At an algebraic level, ASPIN and MSPIN are variants of the same strategy to improve the convergence of systems with unbalanced nonlinearities; however, they have natural complementarity in practice. MSPIN is naturally based on partitioning of degrees of freedom in a nonlinear PDE system by field type rather than by subdomain, where a modest factor of concurrency can be sacrificed for physically motivated convergence robustness. ASPIN, originally introduced for decompositions into subdomains, is natural for high concurrency and reduction of global synchronization. We consider both types of inexact Newton algorithms in the field-split context, and we augment the classical convergence theory of ASPIN for the multiplicative case. Numerical experiments show that MSPIN can be significantly more robust than Newton methods based on global linearizations, and that MSPIN can be more robust than ASPIN and maintain fast convergence even for challenging problems, such as high Reynolds number Navier--Stokes equations.

Field-Split Preconditioned Inexact Newton Algorithms

KAUST Repository

Liu, Lulu; Keyes, David E.

2015-01-01

The multiplicative Schwarz preconditioned inexact Newton (MSPIN) algorithm is presented as a complement to additive Schwarz preconditioned inexact Newton (ASPIN). At an algebraic level, ASPIN and MSPIN are variants of the same strategy to improve the convergence of systems with unbalanced nonlinearities; however, they have natural complementarity in practice. MSPIN is naturally based on partitioning of degrees of freedom in a nonlinear PDE system by field type rather than by subdomain, where a modest factor of concurrency can be sacrificed for physically motivated convergence robustness. ASPIN, originally introduced for decompositions into subdomains, is natural for high concurrency and reduction of global synchronization. We consider both types of inexact Newton algorithms in the field-split context, and we augment the classical convergence theory of ASPIN for the multiplicative case. Numerical experiments show that MSPIN can be significantly more robust than Newton methods based on global linearizations, and that MSPIN can be more robust than ASPIN and maintain fast convergence even for challenging problems, such as high Reynolds number Navier--Stokes equations.

The multigrid preconditioned conjugate gradient method

Science.gov (United States)

Tatebe, Osamu

1993-01-01

A multigrid preconditioned conjugate gradient method (MGCG method), which uses the multigrid method as a preconditioner of the PCG method, is proposed. The multigrid method has inherent high parallelism and improves convergence of long wavelength components, which is important in iterative methods. By using this method as a preconditioner of the PCG method, an efficient method with high parallelism and fast convergence is obtained. First, it is considered a necessary condition of the multigrid preconditioner in order to satisfy requirements of a preconditioner of the PCG method. Next numerical experiments show a behavior of the MGCG method and that the MGCG method is superior to both the ICCG method and the multigrid method in point of fast convergence and high parallelism. This fast convergence is understood in terms of the eigenvalue analysis of the preconditioned matrix. From this observation of the multigrid preconditioner, it is realized that the MGCG method converges in very few iterations and the multigrid preconditioner is a desirable preconditioner of the conjugate gradient method.

Preconditioning of iterative methods - theory and applications

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe; Blaheta, Radim; Neytcheva, M.; Pultarová, I.

2015-01-01

Roč. 22, č. 6 (2015), s. 901-902 ISSN 1070-5325 Institutional support: RVO:68145535 Keywords : preconditioning * iterative methods * applications Subject RIV: BA - General Mathematics Impact factor: 1.431, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/nla.2016/epdf

Aldosterone, mortality, and acute ischaemic events in coronary artery disease patients outside the setting of acute myocardial infarction or heart failure.

Science.gov (United States)

Ivanes, Fabrice; Susen, Sophie; Mouquet, Frédéric; Pigny, Pascal; Cuilleret, François; Sautière, Karine; Collet, Jean-Philippe; Beygui, Farzin; Hennache, Bernadette; Ennezat, Pierre Vladimir; Juthier, Françis; Richard, Florence; Dallongeville, Jean; Hillaert, Marieke A; Doevendans, Pieter A; Jude, Brigitte; Bertrand, Michel; Montalescot, Gilles; Van Belle, Eric

2012-01-01

Recent studies have demonstrated that aldosterone levels measured in patients with heart failure or acute myocardial infarction (MI) are associated with long-term mortality, but the association with aldosterone levels in patients with coronary artery disease (CAD) outside these specific settings remains unknown. In addition, no clear mechanism has been elucidated to explain these observations. The present study was designed to evaluate the relationship between the level of aldosterone and the risk of death and acute ischaemic events in CAD patients with a preserved left ventricular (LV) function and no acute MI. In 799 consecutive CAD patients referred for elective coronary angioplasty measurements were obtained before the procedure for: aldosterone (median = 25 pg/mL), brain natriuretic peptide (BNP) (median = 35 pg/mL), hsC-reactive protein (median = 4.17 mg/L), and left ventricular ejection fraction (mean = 58%). Patients with acute MI or coronary syndrome (ACS) who required urgent revascularization were not included in the study. The primary endpoint, cardiovascular death, occurred in 41 patients during a median follow-up period of 14.9 months. Secondary endpoints-total mortality, acute ischaemic events (acute MI or ischaemic stroke), and the composite of death and acute ischaemic events-were observed in 52, 54, and 94 patients, respectively. Plasma aldosterone was found to be related to BMI, hypertension and NYHA class, and inversely related to age, creatinine clearance, and use of beta-blockers. Multivariate Cox model analysis demonstrated that aldosterone was independently associated with cardiovascular mortality (P = 0.001), total mortality (P = 0.001), acute ischaemic events (P = 0.01), and the composite of death and acute ischaemic events (P = 0.004). Reclassification analysis, using integrated discrimination improvement (IDI) and net reclassification improvement (NRI), demonstrated incremental predictive value of aldosterone (P acute MI, the level of

The terminal complement complex is generated in chronic leg ulcers in the absence of protectin (CD59)

DEFF Research Database (Denmark)

Balslev, E; Thomsen, H K; Danielsen, L

1999-01-01

Loss of membrane complement regulators accompanied by complement activation is suggested to be involved in the pathophysiological processes leading to tissue damage in myocardial ischaemia. In the present study we have investigated whether the same phenomenon may occur in ischaemic and/or venous...... results suggest that loss of CD59 may enhance deposition of TCC and that complement-dependent inflammation may be an important factor in the tissue-damaging processes seen in chronic leg ulcers....

EFFECT OF HEAT PRECONDITIONING BY MICROWAVE HYPERTHERMIA ON HUMAN SKELETAL MUSCLE AFTER ECCENTRIC EXERCISE

Directory of Open Access Journals (Sweden)

Norio Saga

2008-03-01

Full Text Available The purpose of this study was to clarify whether heat preconditioning results in less eccentric exercise-induced muscle damage and muscle soreness, and whether the repeated bout effect is enhanced by heat preconditioning prior to eccentric exercise. Nine untrained male volunteers aged 23 ± 3 years participated in this study. Heat preconditioning included treatment with a microwave hyperthermia unit (150 W, 20 min that was randomly applied to one of the subject's arms (MW; the other arm was used as a control (CON. One day after heat preconditioning, the subjects performed 24 maximal isokinetic eccentric contractions of the elbow flexors at 30°·s-1 (ECC1. One week after ECC1, the subjects repeated the procedure (ECC2. After each bout of exercise, maximal voluntary contraction (MVC, range of motion (ROM of the elbow joint, upper arm circumference, blood creatine kinase (CK activity and muscle soreness were measured. The subjects experienced both conditions at an interval of 3 weeks. MVC and ROM in the MW were significantly higher than those in the CON (p < 0.05 for ECC1; however, the heat preconditioning had no significant effect on upper arm circumference, blood CK activity, or muscle soreness following ECC1 and ECC2. Heat preconditioning may protect human skeletal muscle from eccentric exercise-induced muscle damage after a single bout of eccentric exercise but does not appear to promote the repeated bout effect after a second bout of eccentric exercise

Predictors of early neurological deterioration after ischaemic stroke: a case-control study.

Science.gov (United States)

Barber, Mark; Wright, Fiona; Stott, David J; Langhorne, Peter

2004-01-01

Early neurological deterioration after ischaemic stroke (stroke in progression) is reported to be common and associated with poor outcome or death. The causes of progressing stroke are, however, uncertain. To determine whether prior drug treatment (with anticoagulant or antiplatelet agents) or early adverse physiological features (pyrexia, hypoxia, dehydration or hyperglycaemia) are associated with progressing ischaemic stroke. The study used a case-control design. From a database of 873 consecutive acute stroke admissions, 196 cases of progressing ischaemic stroke (defined by point deterioration in components of the Scandinavian Stroke Scale or death over the first 72 h after hospital admission) were matched to 196 controls on the basis of age and stroke type. Univariate and conditional logistic regression techniques were used to explore predictors of progressing stroke. Cases and controls were well matched for baseline stroke severity. Warfarin use prior to admission was associated with a reduced risk of progressing stroke [odds ratio (OR) 0.10, p = 0.005]. Prior antiplatelet use was not related. A previous history of diabetes (OR 2.11, p = 0.039) and elevated systolic blood pressure on admission (OR 1.01 for each 1 mm Hg rise, p = 0.017) predicted progressing stroke. Although there were no differences in time to presentation or to brain imaging, a visible causative lesion on CT scanning was more common in the progressing stroke group (OR 2.30, p = 0.022). We found no evidence that adverse physiological features were associated with progressing stroke. Outcomes were worse in the progressing stroke group with 70% being dead or dependent by 30 days compared to 55% in the control group (p = 0.002). Prior warfarin use may be protective against progressing ischaemic stroke. A previous history of diabetes along with elevated admission systolic blood pressure predict deterioration. We found no evidence for an association between adverse physiological features and

Sensitivity of different types of fibres in rabbit skeletal muscle to pneumatic compression by tourniquet and to ischaemia.

Science.gov (United States)

Fridén, J; Pedowitz, R A; Thornell, L E

1994-06-01

Morphometric properties (distribution of types of fibre and fibre areas) in the non-necrotic regions of four different rabbit muscles (superficial portions of semimembranosus, biceps femoris, tibialis anterior, and soleus muscles) were measured 48 hours after a tourniquet had been applied around the thigh for two hours at either 125 or 350 mmHg. There was an considerable increase of the relative numbers of both large and small fibres as well as changes in the proportions of the types of fibre. The most dramatic percentage change in type of fibre was in the semimembranosus when compressed at 350 mmHg, which showed an increase of the relative frequency of fibres with type 2AB staining characteristics from 10.2% to 18.0% (p < 0.001). Extreme changes in fibre area were found exclusively in semimembranosus and biceps femoris. Most fibres of abnormal size were of type 2, type 2B fibre areas being the most affected. This study shows that morphometry is a valuable tool in the assessment of the more subtle indications of injury. Compression and ischaemia together have a more dramatic effect on muscle morphology and morphometric properties in the non-necrotic regions than ischaemia alone. These data also show that muscles are differentially sensitive to compression and ischaemia. This information may be useful into the understanding of more complex functional deficits observed after the use of tourniquet.

A Preconditioning Technique for First-Order Primal-Dual Splitting Method in Convex Optimization

Directory of Open Access Journals (Sweden)

Meng Wen

2017-01-01

Full Text Available We introduce a preconditioning technique for the first-order primal-dual splitting method. The primal-dual splitting method offers a very general framework for solving a large class of optimization problems arising in image processing. The key idea of the preconditioning technique is that the constant iterative parameters are updated self-adaptively in the iteration process. We also give a simple and easy way to choose the diagonal preconditioners while the convergence of the iterative algorithm is maintained. The efficiency of the proposed method is demonstrated on an image denoising problem. Numerical results show that the preconditioned iterative algorithm performs better than the original one.

Endomorphins potentiate acid-sensing ion channel currents and enhance the lactic acid-mediated increase in arterial blood pressure: effects amplified in hindlimb ischaemia.

Science.gov (United States)

Farrag, Mohamed; Drobish, Julie K; Puhl, Henry L; Kim, Joyce S; Herold, Paul B; Kaufman, Marc P; Ruiz-Velasco, Victor

2017-12-01

Chronic limb ischaemia, characterized by inflammatory mediator release and a low extracellular pH, leads to acid-sensing ion channel (ASIC) activation and reflexively increases mean arterial pressure; endomorphin release is also increased under inflammatory conditions. We examined the modulation of ASIC currents by endomorphins in sensory neurons from rats with freely perfused and ligated femoral arteries: peripheral artery disease (PAD) model. Endomorphins potentiated sustained ASIC currents in both groups of dorsal root ganglion neurons, independent of mu opioid receptor stimulation or G protein activation. Intra-arterial administration of lactic acid (to simulate exercising muscle and evoke a pressor reflex), endomorphin-2 and naloxone resulted in a significantly greater pressor response than lactic acid alone, while administration of APETx2 inhibited endomorphin's enhancing effect in both groups. These results suggest a novel role for endomorphins in modulating ASIC function to effect lactic acid-mediated reflex increase in arterial pressure in patients with PAD. Chronic muscle ischaemia leads to accumulation of lactic acid and other inflammatory mediators with a subsequent drop in interstitial pH. Acid-sensing ion channels (ASICs), expressed in thin muscle afferents, sense the decrease in pH and evoke a pressor reflex known to increase mean arterial pressure. The naturally occurring endomorphins are also released by primary afferents under ischaemic conditions. We examined whether high affinity mu opioid receptor (MOR) agonists, endomorphin-1 (E-1) and -2 (E-2), modulate ASIC currents and the lactic acid-mediated pressor reflex. In rat dorsal root ganglion (DRG) neurons, exposure to E-2 in acidic solutions significantly potentiated ASIC currents when compared to acidic solutions alone. The potentiation was significantly greater in DRG neurons isolated from rats whose femoral arteries were ligated for 72 h. Sustained ASIC current potentiation was also observed

Cost-effectiveness of remote ischaemic conditioning as an adjunct to primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction

DEFF Research Database (Denmark)

Sloth, Astrid D; Schmidt, Michael R; Munk, Kim

2016-01-01

AIMS: Remote ischaemic conditioning seems to improve long-term clinical outcomes in patients undergoing primary percutaneous coronary intervention. Remote ischaemic conditioning can be applied with cycles of alternating inflation and deflation of a blood-pressure cuff. We evaluated the cost...

Impact of remote ischemic preconditioning on wound healing in small bowel anastomoses

Science.gov (United States)

Holzner, Philipp Anton; Kulemann, Birte; Kuesters, Simon; Timme, Sylvia; Hoeppner, Jens; Hopt, Ulrich Theodor; Marjanovic, Goran

2011-01-01

AIM: To investigate the influence of remote ischemic preconditioning (RIPC) on anastomotic integrity. METHODS: Sixty male Wistar rats were randomized to six groups. The control group (n = 10) had an end-to-end ileal anastomosis without RIPC. The preconditioned groups (n = 34) varied in time of ischemia and time of reperfusion. One group received the amino acid L-arginine before constructing the anastomosis (n = 9). On postoperative day 4, the rats were re-laparotomized, and bursting pressure, hydroxyproline concentration, intra-abdominal adhesions, and a histological score concerning the mucosal ischemic injury were collected. The data are given as median (range). RESULTS: On postoperative day 4, median bursting pressure was 124 mmHg (60-146 mmHg) in the control group. The experimental groups did not show a statistically significant difference (P > 0.05). Regarding the hydroxyproline concentration, we did not find any significant variation in the experimental groups. We detected significantly less mucosal injury in the RIPC groups. Furthermore, we assessed more extensive intra-abdominal adhesions in the preconditioned groups than in the control group. CONCLUSION: RIPC directly before performing small bowel anastomosis does not affect anastomotic stability in the early period, as seen in ischemic preconditioning. PMID:21455330

Streptococcus thermophilus bacteraemia in a patient with transient bowel ischaemia secondary to polycythaemia

OpenAIRE

Stephens, Joanna; Turner, David P.J.

2015-01-01

Introduction: The ability of Streptococcus thermophilus to convert lactose into lactic acid has long been utilised by the dairy industry. A seemingly low-pathogenicity organism, there have been no previously published reports linking the consumption of foodstuffs to bacteraemia with this bacterium.\\ud Case Presentation: Here we present a case of a regular consumer of Activia yoghurt who developed S. thermophilus bacteraemia probably due to transient bowel ischaemia secondary to polycythaemia....

Targeting hexokinase II to mitochondria to modulate energy metabolism and reduce ischaemia-reperfusion injury in heart

NARCIS (Netherlands)

Nederlof, Rianne; Eerbeek, Otto; Hollmann, Markus W.; Southworth, Richard; Zuurbier, Coert J.

2014-01-01

Mitochondrially bound hexokinase II (mtHKII) has long been known to confer cancer cells with their resilience against cell death. More recently, mtHKII has emerged as a powerful protector against cardiac cell death. mtHKII protects against ischaemia-reperfusion (IR) injury in skeletal muscle and

Effects of a heat shock protein inducer on the atrial fibrillation substrate caused by acute atrial ischaemia

NARCIS (Netherlands)

Sakabe, Masao; Shiroshita-Takeshita, Akiko; Maguy, Ange; Brundel, Bianca J. J. M.; Fujiki, Akira; Inoue, Hiroshi; Nattel, Stanley

2008-01-01

Aims Heat shock proteins (HSPs) are a set of endogenous cytoprotective factors activated by various pathological conditions. This study addressed the effects of geranylgeranylacetone (GGA), an orally active HSP inducer, on the atrial fibrillation (AF) substrate associated with acute atria( ischaemia

Diffusion-weighted imaging of brain metastases: their potential to be misinterpreted as focal ischaemic lesions

Energy Technology Data Exchange (ETDEWEB)

Geijer, B. [Department of Radiology, University Hospital, Lund (Sweden); Holtaas, S. [Department of Diagnostic Imaging, King Fahd Hospital, Riyadh (Saudi Arabia)

2002-07-01

Small focal ischaemic brain lesions are said to be easy to identify in the acute stage and to differentiate from older lesions using diffusion-weighted imaging (DWI). Brain metastases are common and the aim of this study was to evaluate the risk of misinterpretation as ischaemic lesions in a standard MRI protocol for clinical stroke. Of 26 patients investigated with MRI for possible metastases, 12 did have metastatic brain lesions, including most of the common tumours. On a 1.5 tesla imager, we obtained DWI, plus T2- and T1-weighted images, the latter before and after triple-dose contrast medium. Well-circumscribed brain lesions with a decreased apparent diffusion coefficient and a slightly or moderately increased signal on T2-weighted images were found in patients with metastases from a small-cell bronchial carcinoma and a pulmonary adenocarcinoma. The same features were also found in metastases from a breast carcinoma but the lesions were surrounded by oedema. With a standard DWI protocol, the features of common brain metastases may overlap with those of small acute and subacute ischaemic lesions. (orig.)

201thallium myocardial scintigraphy. A non-invasive method for diagnosis of ischaemic heart disease

International Nuclear Information System (INIS)

Kyst Madsen, J.; Utne, H.E.

1982-01-01

Myocardial perfusion scintigraphy with the isotope 201 thallium is a new non-invasive technique for the diagnosis of ischaemic heart disease. This article presents the results of scintigraphy in four persons with presumably healthy hearts and 12 with ischaemic heart disease. In addition, some foreign works are reviewed. The method possesses only slightly greater nosographical sensitivity than the exercise ECG alone but can be employed to advantage if the results of the exercise ECG are inconclusive e.g. on account of bundle branch block, digoxin therapy etc. Another, although somewhat more special indication, is employment prior to and after coronary artery by-pass operation with subsequent control of the result. (authors)

Only a fraction of patients with ischaemic diseases or diabetes are treated to recommended target values for plasma lipids

DEFF Research Database (Denmark)

Siggaard-Andersen, Niels; Freiberg, Jacob J; Nordestgaard, Børge G

2012-01-01

We tested the hypothesis that individuals in the general population with and without ischaemic cardiovascular disease, or with diabetes, are treated to recommended target values for plasma lipids.......We tested the hypothesis that individuals in the general population with and without ischaemic cardiovascular disease, or with diabetes, are treated to recommended target values for plasma lipids....

Impact of pre-conditioning on the qualification of safety-related equipment

International Nuclear Information System (INIS)

Isgro, J.R.

1982-01-01

This paper shares some recent experiences on the effects of preconditioning on the qualification of safety-related equipment not located in a harsh environment. Environmental and seismic qualification testing programs were conducted following the guidelines of IEEE 323-1974, IEEE 344-1975 and appropriate IEEE daughter standards, where available. The examples that follow will illustrate the degree of pre-conditioning of safety-related equipment qualified to the requirements of IEEE-323-1974, and its effect on the outcome of the qualification program

Integrity of Cerebellar Fastigial Nucleus Intrinsic Neurons Is Critical for the Global Ischemic Preconditioning

Directory of Open Access Journals (Sweden)

Eugene V. Golanov

2017-09-01

Full Text Available Excitation of intrinsic neurons of cerebellar fastigial nucleus (FN renders brain tolerant to local and global ischemia. This effect reaches a maximum 72 h after the stimulation and lasts over 10 days. Comparable neuroprotection is observed following sublethal global brain ischemia, a phenomenon known as preconditioning. We hypothesized that FN may participate in the mechanisms of ischemic preconditioning as a part of the intrinsic neuroprotective mechanism. To explore potential significance of FN neurons in brain ischemic tolerance we lesioned intrinsic FN neurons with excitotoxin ibotenic acid five days before exposure to 20 min four-vessel occlusion (4-VO global ischemia while analyzing neuronal damage in Cornu Ammoni area 1 (CA1 hippocampal area one week later. In FN-lesioned animals, loss of CA1 cells was higher by 22% compared to control (phosphate buffered saline (PBS-injected animals. Moreover, lesion of FN neurons increased morbidity following global ischemia by 50%. Ablation of FN neurons also reversed salvaging effects of five-minute ischemic preconditioning on CA1 neurons and morbidity, while ablation of cerebellar dentate nucleus neurons did not change effect of ischemic preconditioning. We conclude that FN is an important part of intrinsic neuroprotective system, which participates in ischemic preconditioning and may participate in naturally occurring neuroprotection, such as “diving response”.

Is Remodelling of Corticospinal Tract Terminations Originating in the Intact Hemisphere Associated with Recovery following Transient Ischaemic Stroke in the Rat?

Directory of Open Access Journals (Sweden)

Emma J Mitchell

Full Text Available Following large strokes that encompass the cerebral cortex, it has been suggested that the corticospinal tract originating from the non-ischaemic hemisphere reorganises its pattern of terminal arborisation within the spinal cord to compensate for loss of function. However many strokes in humans predominantly affect subcortical structures with minimal involvement of the cerebral cortex. The aim of the present study was to determine whether remodelling of corticospinal terminals arising from the non-ischaemic hemisphere was associated with spontaneous recovery in rats with subcortical infarcts. Rats were subjected to transient middle cerebral artery occlusion or sham surgery and 28 days later, when animals exhibited functional recovery, cholera toxin b subunit was injected into the contralesional, intact forelimb motor cortex in order to anterogradely label terminals within cervical spinal cord segments. Infarcts were limited to subcortical structures and resulted in partial loss of corticospinal tract axons from the ischaemic hemisphere. Quantitative analysis revealed there was no significant difference in the numbers of terminals on the contralesional side of the spinal grey matter between ischaemic and sham rats. The results indicate that significant remodelling of the corticospinal tract from the non-ischaemic hemisphere is not associated with functional recovery in animals with subcortical infarcts.

[Moyamoya disease as a rare cause of ischaemic stroke--case report].

Science.gov (United States)

Kułakowska, Alina; Kapica-Topczewska, Katarzyna; Borowik, Helena; Drozdowski, Wiesław

2009-10-01

Moyamoya disease is a rare, progressive disease of the vessels diagnosed according to characteristic abnormalities of brain arteries in the angiography. The incidence of moyamoya disease in Europe is lower than in Asia and its clinical course in European population is probably different from Asiatic (older age of onset and rare incidence of hemorrhagic strokes). Two young patients were diagnosed as moyamoya disease on the basis of clinical symptoms (ischaemic stroke) and results of brain vessels' angiography, which documented an occlusion of both internal carotid arteries above branching-off the ocular arteries in the first patient and stenosis of distal internal carotid arteries and proximal medial and anterior cerebral arteries in the second one. Both patients are under control of the Neurological Outpatient Department and their neurological state is stable. Despite that moyamoya disease is a rare cause of ischaemic stroke, it should be always considered as one of etiologic factors, especially in young patients.

Rethinking The Going Concern Assumption As A Pre-Condition For Accounting Measurement

OpenAIRE

Saratiel Wedzerai Musvoto; Daan G Gouws

2011-01-01

This study compares the principles of the going concern concept against the principles of representational measurement to determine if it is possible to establish foundations of accounting measurement with the going concern concept as a precondition. Representational measurement theory is a theory that establishes measurement in social scientific disciplines such as accounting. The going concern assumption is prescribed as one of the preconditions for measuring the attributes of the elements ...

Diffusion-weighted MR imaging in transient ischaemic attacks

Energy Technology Data Exchange (ETDEWEB)

Lamy, C.; Calvet, D.; Domigo, V.; Mas, J. [de l' Hopital Sainte-Anne, Service de Neurologie, Paris Cedex 14 (France); Oppenheim, C.; Naggara, O.; Meder, J.F. [Hoepital Sainte-Anne, Departement d' Imagere Morphologique et Fonchonnille, Paris (France)

2006-05-15

The purpose of this study was to determine frequency and the characteristics of diffusion-weighted imaging (DWI) abnormalities in patients with transient ischaemic attack (TIA). We analysed data of 98 consecutive patients (mean age: 60.6{+-}15.4 years, 56 men) admitted between January 2003 and April 2004 for TIA. Age, gender, symptom type and duration, delay from onset to magnetic resonance imaging (MRI), probable or possible TIA and cause of TIA were compared in patients with (DWI+) and without (DWI-) lesions on DWI. Volume and apparent diffusion coefficient (ADC) values of DWI lesions were computed. DWI revealed ischaemic lesions in 34 patients (34.7%). Lesions were small (mean volume: 1.9 cm{sup 3}{+-}3.3), and ADC was moderately decreased (mean ADC ratio: 79.5%). The diagnosis of TIA was considered as probable in all DWI+ patients. A multiple logistic regression model demonstrated that TIA duration greater than or equal to 60 min (OR, 7.6; 95% CI, 2.3-25.7), aphasia (OR, 9.2; 95% CI, 2.7-31.4) and motor deficit (OR, 5.1; 95% CI, 1.5-17.8) were independent predictors of DWI lesions. Prolonged TIA duration, aphasia and motor deficits are associated with DWI lesions. More than half of TIA patients with symptoms lasting more than 60 min have DWI lesions. (orig.)

Diffusion-weighted MR imaging in transient ischaemic attacks

International Nuclear Information System (INIS)

Lamy, C.; Calvet, D.; Domigo, V.; Mas, J.; Oppenheim, C.; Naggara, O.; Meder, J.F.

2006-01-01

The purpose of this study was to determine frequency and the characteristics of diffusion-weighted imaging (DWI) abnormalities in patients with transient ischaemic attack (TIA). We analysed data of 98 consecutive patients (mean age: 60.6±15.4 years, 56 men) admitted between January 2003 and April 2004 for TIA. Age, gender, symptom type and duration, delay from onset to magnetic resonance imaging (MRI), probable or possible TIA and cause of TIA were compared in patients with (DWI+) and without (DWI-) lesions on DWI. Volume and apparent diffusion coefficient (ADC) values of DWI lesions were computed. DWI revealed ischaemic lesions in 34 patients (34.7%). Lesions were small (mean volume: 1.9 cm 3 ±3.3), and ADC was moderately decreased (mean ADC ratio: 79.5%). The diagnosis of TIA was considered as probable in all DWI+ patients. A multiple logistic regression model demonstrated that TIA duration greater than or equal to 60 min (OR, 7.6; 95% CI, 2.3-25.7), aphasia (OR, 9.2; 95% CI, 2.7-31.4) and motor deficit (OR, 5.1; 95% CI, 1.5-17.8) were independent predictors of DWI lesions. Prolonged TIA duration, aphasia and motor deficits are associated with DWI lesions. More than half of TIA patients with symptoms lasting more than 60 min have DWI lesions. (orig.)

The effect of preconditioning cells under osmotic stress on high alcohol production

Directory of Open Access Journals (Sweden)

Logotetis Stilijanos

2013-01-01

Full Text Available This paper focuses on the research into the influence of salt on physiology of the yeast, Saccharomyces cerevisiae. Specifically, the work focused on how NaCl affected the growth, viability and fermentation performance of this yeast in laboratory-scale experiments. One of the main findings of the research presented involved the influ­ence of salt “preconditioning” of yeasts which represents a method of pre-culturing of cells in the presence of salt in an attempt to improve subsequent fermentation performance. Such an approach resulted in preconditioned yeasts having an improved capability to ferment high-sugar containing media (up to 60% w/v of glucose with increased cell viability and with increased levels of produced ethanol (higher than 20% in vol.. Salt-preconditioning was most likely influencing the stress-tolerance of yeasts by inducing the synthesis of key metabolites such as trehalose and glycerol which act to improve cells’ ability to withstand osmostress and ethanol toxicity. The industrial-scale trials using salt-preconditioned yeasts verified the benefit of the physiological engineering approach to practical fermentations. Overall, this research has demonstrated that a relatively simple method designed to adapt yeast cells physiologically - by salt-preconditioning - can have distinct advantages for al­cohol fermentation processes.

Hypoxic preconditioning induces neuroprotective stanniocalcin-1 in brain via IL-6 signaling

DEFF Research Database (Denmark)

Westberg, Johan A; Serlachius, Martina; Lankila, Petri

2007-01-01

BACKGROUND AND PURPOSE: Exposure of animals for a few hours to moderate hypoxia confers relative protection against subsequent ischemic brain damage. This phenomenon, known as hypoxic preconditioning, depends on new RNA and protein synthesis, but its molecular mechanisms are poorly understood...... originally reported expression of mammalian STC-1 in brain neurons and showed that STC-1 guards neurons against hypercalcemic and hypoxic damage. METHODS: We treated neural Paju cells with IL-6 and measured the induction of STC-1 mRNA. In addition, we quantified the effect of hypoxic preconditioning on Stc-1...... mRNA levels in brains of wild-type and IL-6 deficient mice. Furthermore, we monitored the Stc-1 response in brains of wild-type and transgenic mice, overexpressing IL-6 in the astroglia, before and after induced brain injury. RESULTS: Hypoxic preconditioning induced an upregulated expression of Stc...

40 CFR 86.232-94 - Vehicle preconditioning.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Vehicle preconditioning. 86.232-94... (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1994 and Later Model Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium...

Galilean-invariant preconditioned central-moment lattice Boltzmann method without cubic velocity errors for efficient steady flow simulations

Science.gov (United States)

Hajabdollahi, Farzaneh; Premnath, Kannan N.

2018-05-01

Lattice Boltzmann (LB) models used for the computation of fluid flows represented by the Navier-Stokes (NS) equations on standard lattices can lead to non-Galilean-invariant (GI) viscous stress involving cubic velocity errors. This arises from the dependence of their third-order diagonal moments on the first-order moments for standard lattices, and strategies have recently been introduced to restore Galilean invariance without such errors using a modified collision operator involving corrections to either the relaxation times or the moment equilibria. Convergence acceleration in the simulation of steady flows can be achieved by solving the preconditioned NS equations, which contain a preconditioning parameter that can be used to tune the effective sound speed, and thereby alleviating the numerical stiffness. In the present paper, we present a GI formulation of the preconditioned cascaded central-moment LB method used to solve the preconditioned NS equations, which is free of cubic velocity errors on a standard lattice, for steady flows. A Chapman-Enskog analysis reveals the structure of the spurious non-GI defect terms and it is demonstrated that the anisotropy of the resulting viscous stress is dependent on the preconditioning parameter, in addition to the fluid velocity. It is shown that partial correction to eliminate the cubic velocity defects is achieved by scaling the cubic velocity terms in the off-diagonal third-order moment equilibria with the square of the preconditioning parameter. Furthermore, we develop additional corrections based on the extended moment equilibria involving gradient terms with coefficients dependent locally on the fluid velocity and the preconditioning parameter. Such parameter dependent corrections eliminate the remaining truncation errors arising from the degeneracy of the diagonal third-order moments and fully restore Galilean invariance without cubic defects for the preconditioned LB scheme on a standard lattice. Several

Interleukin-6 is increased in plasma and cerebrospinal fluid of community-dwelling domestic dogs with acute ischaemic stroke

DEFF Research Database (Denmark)

Gredal, Hanne; Thomsen, Barbara B; Boza-Serrano, Antonio

2017-01-01

itself contributes towards the cytokine response. Community-dwelling domestic dogs suffer from spontaneous ischaemic stroke, and therefore, offer the opportunity to study the cytokine response in a noninvasive set-up. The aims of this study were to investigate cytokine concentrations in plasma...... and cerebrospinal fluid (CSF) in dogs with acute ischaemic stroke and to search for correlations between infarct volume and cytokine concentrations. Blood and CSF were collected from dogs less than 72 h after a spontaneous ischaemic stroke. Infarct volumes were estimated on MRIs. Interleukin (IL)-2, IL-6, IL-8, IL......-10 and tumour necrosis factor in the plasma, CSF and brain homogenates were measured using a canine-specific multiplex immunoassay. IL-6 was significantly increased in plasma (P = 0.04) and CSF (P = 0.04) in stroke dogs compared with healthy controls. The concentrations of other cytokines...

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS)

DEFF Research Database (Denmark)

Bath, Philip M; Woodhouse, Lisa J; Appleton, Jason P

2018-01-01

, and dipyridamole) with that of guideline-based antiplatelet therapy. METHODS: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using...... was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using...... therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did...

Error Estimation in Preconditioned Conjugate Gradients

Czech Academy of Sciences Publication Activity Database

Strakoš, Zdeněk; Tichý, Petr

2005-01-01

Roč. 45, - (2005), s. 789-817 ISSN 0006-3835 R&D Projects: GA AV ČR 1ET400300415; GA AV ČR KJB1030306 Institutional research plan: CEZ:AV0Z10300504 Keywords : preconditioned conjugate gradient method * error bounds * stopping criteria * evaluation of convergence * numerical stability * finite precision arithmetic * rounding errors Subject RIV: BA - General Mathematics Impact factor: 0.509, year: 2005

M-step preconditioned conjugate gradient methods

Science.gov (United States)

Adams, L.

1983-01-01

Preconditioned conjugate gradient methods for solving sparse symmetric and positive finite systems of linear equations are described. Necessary and sufficient conditions are given for when these preconditioners can be used and an analysis of their effectiveness is given. Efficient computer implementations of these methods are discussed and results on the CYBER 203 and the Finite Element Machine under construction at NASA Langley Research Center are included.

Postmortem MR quantification of the heart for characterization and differentiation of ischaemic myocardial lesions

International Nuclear Information System (INIS)

Zech, Wolf-Dieter; Schwendener, Nicole; Jackowski, Christian; Persson, Anders; Warntjes, Marcel J.

2015-01-01

Recently, an MRI quantification sequence has been developed which can be used to acquire T1- and T2-relaxation times as well as proton density (PD) values. Those three quantitative values can be used to describe soft tissue in an objective manner. The purpose of this study was to investigate the applicability of quantitative cardiac MRI for characterization and differentiation of ischaemic myocardial lesions of different age. Fifty post-mortem short axis cardiac 3 T MR examinations have been quantified using a quantification sequence. Myocardial lesions were identified according to histology and appearance in MRI images. Ischaemic lesions were assessed for mean T1-, T2- and proton density values. Quantitative values were plotted in a 3D-coordinate system to investigate the clustering of ischaemic myocardial lesions. A total of 16 myocardial lesions detected in MRI images were histologically characterized as acute lesions (n = 8) with perifocal oedema (n = 8), subacute lesions (n = 6) and chronic lesions (n = 2). In a 3D plot comprising the combined quantitative values of T1, T2 and PD, the clusters of all investigated lesions could be well differentiated from each other. Post-mortem quantitative cardiac MRI is feasible for characterization and discrimination of different age stages of myocardial infarction. (orig.)

Postmortem MR quantification of the heart for characterization and differentiation of ischaemic myocardial lesions

Energy Technology Data Exchange (ETDEWEB)

Zech, Wolf-Dieter; Schwendener, Nicole; Jackowski, Christian [University of Bern, Institute of Forensic Medicine, Bern (Switzerland); Persson, Anders; Warntjes, Marcel J. [University of Linkoeping, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden)

2015-07-15

Recently, an MRI quantification sequence has been developed which can be used to acquire T1- and T2-relaxation times as well as proton density (PD) values. Those three quantitative values can be used to describe soft tissue in an objective manner. The purpose of this study was to investigate the applicability of quantitative cardiac MRI for characterization and differentiation of ischaemic myocardial lesions of different age. Fifty post-mortem short axis cardiac 3 T MR examinations have been quantified using a quantification sequence. Myocardial lesions were identified according to histology and appearance in MRI images. Ischaemic lesions were assessed for mean T1-, T2- and proton density values. Quantitative values were plotted in a 3D-coordinate system to investigate the clustering of ischaemic myocardial lesions. A total of 16 myocardial lesions detected in MRI images were histologically characterized as acute lesions (n = 8) with perifocal oedema (n = 8), subacute lesions (n = 6) and chronic lesions (n = 2). In a 3D plot comprising the combined quantitative values of T1, T2 and PD, the clusters of all investigated lesions could be well differentiated from each other. Post-mortem quantitative cardiac MRI is feasible for characterization and discrimination of different age stages of myocardial infarction. (orig.)

ECG-manifest and ECG-silent dipyridamole technetium-99m sestamibi SPET perfusion defects in patients with ischaemic heart disease

International Nuclear Information System (INIS)

Galli, M.; Marcassa, C.; Bosimini, E.; Zoccarato, O.; Comazzi, F.; Giannuzzi, P.

1997-01-01

To investigate the relationship between ECG changes and perfusion abnormalities, body surface maps were recorded during dipyridamole infusion in 55 subjects (11 normals and 44 patients with ischaemic heart disease) undergoing dipyridamole technetium-99m sestamibi single-photon emission tomography (SPET). All had a normal resting ECG. The extent and severity of the sestamibi defect were quantified. New negative areas in the isointegral maps and rest-dipyridamole map differences >2 SD from normal limits were considered abnormal. After dipyridamole in normals, neither perfusion defects nor ≥1 mm ST segment depression on 12-lead ECG nor new negative areas in isointegral maps occurred. In patients, dipyridamole induced new perfusion defects in 35 (80%) but ST segment depression in only 18 (41%, P<0.001). Of the 35 patients with perfusion defects, 17 (49%, group 1) showed ST segment depression, while the other 18 (51%, group 2) did not. Abnormal body surface maps were found in 100% of group 1 and 88% of group 2 patients (NS). In group 1, the provoked hypoperfusion was of greater extent (P=0.007) and severity (P=0.01) and the onset of map abnormalities was significantly earlier (P<0.001) than in group 2; time to map abnormalities was also significantly shorter than time to ST segment depression (P=0.01). In the 35 patients with complete scintigraphic, body map and angiographic data, the severity of reversible perfusion defect proved to be the strongest correlate of ST segment depression upon logistic regression analysis. Thus, sestamibi SPET abnormalities after dipyridamole are almost always associated with electrical changes on body surface maps, suggesting myocardial ischaemia as their cause. The much less common 12-lead ECG changes are slower to appear and reflect a more severe hypoperfusion. (orig./MG). With 5 figs., 4 tabs

40 CFR 86.132-00 - Vehicle preconditioning.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Vehicle preconditioning. 86.132-00... (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles and New Light-Duty Trucks and New Otto-Cycle Complete...

High-Order Calderón Preconditioned Time Domain Integral Equation Solvers

KAUST Repository

Valdes, Felipe; Ghaffari-Miab, Mohsen; Andriulli, Francesco P.; Cools, Kristof; Michielssen,

2013-01-01

Two high-order accurate Calderón preconditioned time domain electric field integral equation (TDEFIE) solvers are presented. In contrast to existing Calderón preconditioned time domain solvers, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of fully-localized high-order div-and quasi curl-conforming (DQCC) basis functions. Numerical results demonstrate that the linear systems of equations obtained using the proposed basis functions converge rapidly, regardless of the mesh density and of the order of the current expansion. © 1963-2012 IEEE.

High-Order Calderón Preconditioned Time Domain Integral Equation Solvers

KAUST Repository

Valdes, Felipe

2013-05-01

Two high-order accurate Calderón preconditioned time domain electric field integral equation (TDEFIE) solvers are presented. In contrast to existing Calderón preconditioned time domain solvers, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of fully-localized high-order div-and quasi curl-conforming (DQCC) basis functions. Numerical results demonstrate that the linear systems of equations obtained using the proposed basis functions converge rapidly, regardless of the mesh density and of the order of the current expansion. © 1963-2012 IEEE.

PRECONDITIONED BI-CONJUGATE GRADIENT METHOD FOR RADIATIVE TRANSFER IN SPHERICAL MEDIA

International Nuclear Information System (INIS)

Anusha, L. S.; Nagendra, K. N.; Paletou, F.; Leger, L.

2009-01-01

A robust numerical method called the Preconditioned Bi-Conjugate Gradient (Pre-BiCG) method is proposed for the solution of the radiative transfer equation in spherical geometry. A variant of this method called Stabilized Preconditioned Bi-Conjugate Gradient (Pre-BiCG-STAB) is also presented. These are iterative methods based on the construction of a set of bi-orthogonal vectors. The application of the Pre-BiCG method in some benchmark tests shows that the method is quite versatile, and can handle difficult problems that may arise in astrophysical radiative transfer theory.

PRECONDITIONED CONJUGATE-GRADIENT 2 (PCG2), a computer program for solving ground-water flow equations

Science.gov (United States)

Hill, Mary C.

1990-01-01

This report documents PCG2 : a numerical code to be used with the U.S. Geological Survey modular three-dimensional, finite-difference, ground-water flow model . PCG2 uses the preconditioned conjugate-gradient method to solve the equations produced by the model for hydraulic head. Linear or nonlinear flow conditions may be simulated. PCG2 includes two reconditioning options : modified incomplete Cholesky preconditioning, which is efficient on scalar computers; and polynomial preconditioning, which requires less computer storage and, with modifications that depend on the computer used, is most efficient on vector computers . Convergence of the solver is determined using both head-change and residual criteria. Nonlinear problems are solved using Picard iterations. This documentation provides a description of the preconditioned conjugate gradient method and the two preconditioners, detailed instructions for linking PCG2 to the modular model, sample data inputs, a brief description of PCG2, and a FORTRAN listing.

Association of ABO blood groups and major ischaemic heart disease risk factors

International Nuclear Information System (INIS)

Lutf-Ullah, L.; Akhtar, B.; Noor-Us-Saba; Hanif, A.; Khan, B.Z.; Bukhshi, I.M.

2010-01-01

To study the association of ABO blood groups with major ischaemic heart disease risk factors. Setting: Department of Cardiology, Mayo hospital, Lahore over a period of two years from January 2008 to December 2009. Study Design: Analytic comparative study. Subjects and Methods: The study group included 907 patients of ischaemic heart disease (IHD). The distribution of ABO blood groups in IHD patients was compared for presence or absence of major IHD risk factors. Data was analyzed using SPSS 16. ANOVA and Chi-square tests for significance were used. P-value less than 0.05 was taken as significant. Results: In this study, the following pattern of ABO blood groups was observed in IHD patients : blood group A 251 (27.67%); blood group B 329 (36.27%); blood group O 235 (25.91%); blood group AB 92 (10.14%). We found no relation-ship of ABO blood groups with age (p-value = 0.234), gender (p-value = 0.093), hypertension (p-value = 0.230), diabetes mellitus (p-value = 0.801), family history of IHD (p-value = 0.277), transverse ear lobe crease (p-value = 0.231), total cholesterol (p-value = 0.797), triglycerides (p-value = 0.351), low density lipoprotein (p-value = 0.078), high density lipoprotein (p-value = 0.114). Similarly no relationship was found of smoking, weight, height and body mass index with ABO blood groups, p-values 0.428, 0.528, 0.908 and 0.455 respectively. Conclusion: There is no association of ABO blood groups and major ischaemic heart disease risk factors. (author)

Epilepsy in Hemiplegic Cerebral Palsy Due to Perinatal Arterial Ischaemic Stroke

Science.gov (United States)

Wanigasinghe, Jithangi; Reid, Susan M.; Mackay, Mark T.; Reddihough, Dinah S.; Harvey, A. Simon; Freeman, Jeremy L.

2010-01-01

Aim: The aim of this study was to describe the frequency, risk factors, manifestations, and outcome of epilepsy in children with hemiplegic cerebral palsy (CP) due to perinatal arterial ischaemic stroke (AIS). Method: The study group comprised 63 participants (41 males, 22 females) from a population-based CP register whose brain imaging showed…

Guidelines for the preventive treatment of ischaemic stroke and TIA (I). Update on risk factors and life style.

Science.gov (United States)

Fuentes, B; Gállego, J; Gil-Nuñez, A; Morales, A; Purroy, F; Roquer, J; Segura, T; Tejada, J; Lago, A; Díez-Tejedor, E; Alonso de Leciñana, M; Alvarez-Sabin, J; Arenillas, J; Calleja, S; Casado, I; Castellanos, M; Castillo, J; Dávalos, A; Díaz-Otero, F; Egido, J A; López-Fernández, J C; Freijo, M; García Pastor, A; Gilo, F; Irimia, P; Maestre, J; Masjuan, J; Martí-Fábregas, J; Martínez-Sánchez, P; Martínez-Vila, E; Molina, C; Nombela, F; Ribó, M; Rodríguez-Yañez, M; Rubio, F; Serena, J; Simal, P; Vivancos, J

2012-01-01

To update the ad hoc Committee of the Cerebrovascular Diseases Study Group of The Spanish Neurological Society guidelines on prevention of ischaemic stroke (IS) and transient ischaemic attack (TIA). We reviewed available evidence on risk factors and means of modifying them to prevent ischaemic stroke and TIA. Levels of evidence and recommendation grades are based on the classification of the Centre for Evidence-Based Medicine. This first section summarises the recommendations for action on the following factors: blood pressure, diabetes, lipids, tobacco and alcohol consumption, diet and physical activity, cardio-embolic diseases, asymptomatic carotid stenosis, hormone replacement therapy and contraceptives, hyperhomocysteinemia, prothrombotic states and sleep apnea syndrome. Changes in lifestyle and pharmacological treatment for hypertension, diabetes mellitus and dyslipidemia, according to criteria of primary and secondary prevention, are recommended for preventing ischemic stroke. © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Curved reformat of the paediatric brain MRI into a 'flat-earth map' - standardised method for demonstrating cortical surface atrophy resulting from hypoxic-ischaemic encephalopathy.

Science.gov (United States)

Simpson, Ewan; Andronikou, Savvas; Vedajallam, Schadie; Chacko, Anith; Thai, Ngoc Jade

2016-09-01

Hypoxic-ischaemic encephalopathy is optimally imaged with brain MRI in the neonatal period. However neuroimaging is often also performed later in childhood (e.g., when parents seek compensation in cases of alleged birth asphyxia). We describe a standardised technique for creating two curved reconstructions of the cortical surface to show the characteristic surface changes of hypoxic-ischaemic encephalopathy in children imaged after the neonatal period. The technique was applied for 10 cases of hypoxic-ischaemic encephalopathy and also for age-matched healthy children to assess the visibility of characteristic features of hypoxic-ischaemic encephalopathy. In the abnormal brains, fissural or sulcal widening was seen in all cases and ulegyria was identifiable in 7/10. These images could be used as a visual aid for communicating MRI findings to clinicians and other interested parties.

Use of the preconditioned conjugate gradient algorithm as a generic solver for mixed-model equations in animal breeding applications.

Science.gov (United States)

Tsuruta, S; Misztal, I; Strandén, I

2001-05-01

Utility of the preconditioned conjugate gradient algorithm with a diagonal preconditioner for solving mixed-model equations in animal breeding applications was evaluated with 16 test problems. The problems included single- and multiple-trait analyses, with data on beef, dairy, and swine ranging from small examples to national data sets. Multiple-trait models considered low and high genetic correlations. Convergence was based on relative differences between left- and right-hand sides. The ordering of equations was fixed effects followed by random effects, with no special ordering within random effects. The preconditioned conjugate gradient program implemented with double precision converged for all models. However, when implemented in single precision, the preconditioned conjugate gradient algorithm did not converge for seven large models. The preconditioned conjugate gradient and successive overrelaxation algorithms were subsequently compared for 13 of the test problems. The preconditioned conjugate gradient algorithm was easy to implement with the iteration on data for general models. However, successive overrelaxation requires specific programming for each set of models. On average, the preconditioned conjugate gradient algorithm converged in three times fewer rounds of iteration than successive overrelaxation. With straightforward implementations, programs using the preconditioned conjugate gradient algorithm may be two or more times faster than those using successive overrelaxation. However, programs using the preconditioned conjugate gradient algorithm would use more memory than would comparable implementations using successive overrelaxation. Extensive optimization of either algorithm can influence rankings. The preconditioned conjugate gradient implemented with iteration on data, a diagonal preconditioner, and in double precision may be the algorithm of choice for solving mixed-model equations when sufficient memory is available and ease of implementation is

The clinical profile of women with stable ischaemic heart disease in Spain. More effort is needed in secondary prevention. SIRENA study.

Science.gov (United States)

Gámez, J M; Ripoll, T; Barrios, V; Anguita, M; Pedreira, M; Madariaga, I

2016-01-01

Cardiovascular diseases are the leading cause of death for women, especially ischaemic heart disease, which is still considered a man's disease. In Spain, there are various registries on ischaemic heart disease, although none are exclusively for women. The objectives of the SIRENA study were to describe the clinical profile of women with ischaemic heart disease treated in cardiology consultations, to estimate its prevalence of cardiovascular risk factors and understand its clinical management. A multicentre observational study was conducted with a sample of 631 women with stable ischaemic heart disease, consecutively included during cardiology consultations. Forty-one researchers from all over Spain participated in the study. The mean age was 68.5 years. The clinical presentation was in the form of acute coronary syndrome in up to 67.2% of the patients. The prevalence of cardiovascular risk factors was high (77.7% of the patients had hypertension, 40.7% had diabetes and 68% had dyslipidaemia), with 30.7% having uncontrolled hypertension, 78.4% having LDL-cholesterol levels higher than 70mg/dL and 49.2% having HbA1c levels greater than 7%. The considerable majority of the patients underwent optimal medical treatment with antiplatelet agents, beta-blockers, renin-angiotensin-aldosterone system blockers and hypolipidaemic agents. Coronary angiography was performed for 88.3% of the patients, and 63.4% underwent percutaneous coronary intervention. Women with stable ischaemic heart disease in Spain initially present some form of acute coronary syndrome and a high prevalence of inadequately controlled cardiovascular risk factors, despite undergoing optimal medical therapy. A high percentage of these women undergo coronary revascularisation. Increased efforts are required for secondary prevention in women with stable ischaemic heart disease. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Ischemic preconditioning enhances integrity of coronary endothelial tight junctions

International Nuclear Information System (INIS)

Li, Zhao; Jin, Zhu-Qiu

2012-01-01

Highlights: ► Cardiac tight junctions are present between coronary endothelial cells. ► Ischemic preconditioning preserves the structural and functional integrity of tight junctions. ► Myocardial edema is prevented in hearts subjected to ischemic preconditioning. ► Ischemic preconditioning enhances translocation of ZO-2 from cytosol to cytoskeleton. -- Abstract: Ischemic preconditioning (IPC) is one of the most effective procedures known to protect hearts against ischemia/reperfusion (IR) injury. Tight junction (TJ) barriers occur between coronary endothelial cells. TJs provide barrier function to maintain the homeostasis of the inner environment of tissues. However, the effect of IPC on the structure and function of cardiac TJs remains unknown. We tested the hypothesis that myocardial IR injury ruptures the structure of TJs and impairs endothelial permeability whereas IPC preserves the structural and functional integrity of TJs in the blood–heart barrier. Langendorff hearts from C57BL/6J mice were prepared and perfused with Krebs–Henseleit buffer. Cardiac function, creatine kinase release, and myocardial edema were measured. Cardiac TJ function was evaluated by measuring Evans blue-conjugated albumin (EBA) content in the extravascular compartment of hearts. Expression and translocation of zonula occludens (ZO)-2 in IR and IPC hearts were detected with Western blot. A subset of hearts was processed for the observation of ultra-structure of cardiac TJs with transmission electron microscopy. There were clear TJs between coronary endothelial cells of mouse hearts. IR caused the collapse of TJs whereas IPC sustained the structure of TJs. IR increased extravascular EBA content in the heart and myocardial edema but decreased the expression of ZO-2 in the cytoskeleton. IPC maintained the structure of TJs. Cardiac EBA content and edema were reduced in IPC hearts. IPC enhanced the translocation of ZO-2 from cytosol to cytoskeleton. In conclusion, TJs occur in

Ischemic preconditioning enhances integrity of coronary endothelial tight junctions

Energy Technology Data Exchange (ETDEWEB)

Li, Zhao [Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, SD 57007 (United States); Jin, Zhu-Qiu, E-mail: zhu-qiu.jin@sdstate.edu [Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, SD 57007 (United States)

2012-08-31

Highlights: Black-Right-Pointing-Pointer Cardiac tight junctions are present between coronary endothelial cells. Black-Right-Pointing-Pointer Ischemic preconditioning preserves the structural and functional integrity of tight junctions. Black-Right-Pointing-Pointer Myocardial edema is prevented in hearts subjected to ischemic preconditioning. Black-Right-Pointing-Pointer Ischemic preconditioning enhances translocation of ZO-2 from cytosol to cytoskeleton. -- Abstract: Ischemic preconditioning (IPC) is one of the most effective procedures known to protect hearts against ischemia/reperfusion (IR) injury. Tight junction (TJ) barriers occur between coronary endothelial cells. TJs provide barrier function to maintain the homeostasis of the inner environment of tissues. However, the effect of IPC on the structure and function of cardiac TJs remains unknown. We tested the hypothesis that myocardial IR injury ruptures the structure of TJs and impairs endothelial permeability whereas IPC preserves the structural and functional integrity of TJs in the blood-heart barrier. Langendorff hearts from C57BL/6J mice were prepared and perfused with Krebs-Henseleit buffer. Cardiac function, creatine kinase release, and myocardial edema were measured. Cardiac TJ function was evaluated by measuring Evans blue-conjugated albumin (EBA) content in the extravascular compartment of hearts. Expression and translocation of zonula occludens (ZO)-2 in IR and IPC hearts were detected with Western blot. A subset of hearts was processed for the observation of ultra-structure of cardiac TJs with transmission electron microscopy. There were clear TJs between coronary endothelial cells of mouse hearts. IR caused the collapse of TJs whereas IPC sustained the structure of TJs. IR increased extravascular EBA content in the heart and myocardial edema but decreased the expression of ZO-2 in the cytoskeleton. IPC maintained the structure of TJs. Cardiac EBA content and edema were reduced in IPC hearts. IPC

Doxorubicin induced myocardial injury is exacerbated following ischaemic stress via opening of the mitochondrial permeability transition pore

Energy Technology Data Exchange (ETDEWEB)

Gharanei, M.; Hussain, A. [Department of Biomolecular and Sport Sciences, Coventry University, Cox Street, Coventry, CV1 5FB (United Kingdom); Janneh, O. [Department of Biomolecular and Sport Sciences, Coventry University, Cox Street, Coventry, CV1 5FB (United Kingdom); Pharmacology Research Laboratories, 70, Pembroke Place, The University of Liverpool, Liverpool. L69 3GF (United Kingdom); Maddock, H.L., E-mail: h.maddock@coventry.ac.uk [Department of Biomolecular and Sport Sciences, Coventry University, Cox Street, Coventry, CV1 5FB (United Kingdom)

2013-04-15

Chemotherapeutic agents such as doxorubicin are known to cause or exacerbate cardiovascular cell death when an underlying heart condition is present. However, the mechanism of doxorubicin-induced cardiotoxicity is unclear. Here we assess the cardiotoxic effects of doxorubicin in conditions of myocardial ischaemia reperfusion and the mechanistic basis of protection, in particular the role of the mitochondrial permeability transition pore (mPTP) in such protection. The effects of doxorubicin (1 μM) ± cyclosporine A (CsA, 0.2 μM; inhibits mPTP) were investigated in isolated male Sprague–Dawley rats using Langendorff heart and papillary muscle contraction models subjected to simulated ischaemia and reperfusion injury. Isolated rat cardiac myocytes were used in an oxidative stress model to study the effects of drug treatment on mPTP by confocal microscopy. Western blot analysis evaluated the effects of drug treatment on p-Akt and p-Erk 1/2 levels. Langendorff and the isometric contraction models showed a detrimental effect of doxorubicin throughout reperfusion/reoxygenation as well as increased p-Akt and p-Erk levels. Interestingly, CsA not only reversed the detrimental effects of doxorubicin, but also reduced p-Akt and p-Erk levels. In the sustained oxidative stress assay to study mPTP opening, doxorubicin decreased the time taken to depolarization and hypercontracture, but these effects were delayed in the presence of CsA. Collectively, our data suggest for the first that doxorubicin exacerbates myocardial injury in an ischaemia reperfusion model. If the inhibition of mPTP ameliorates the cardiotoxic effects of doxorubicin, then more selective inhibitors of mPTP should be further investigated for their utility in patients receiving doxorubicin. - Highlights: ► Doxorubicin exacerbates myocardial ischaemia reperfusion injury. ► Co-treatment with CsA protects against doxorubicin induced myocardial injury. ► CsA delays doxorubicin induced mPTP opening in laser

Doxorubicin induced myocardial injury is exacerbated following ischaemic stress via opening of the mitochondrial permeability transition pore

International Nuclear Information System (INIS)

Gharanei, M.; Hussain, A.; Janneh, O.; Maddock, H.L.

2013-01-01

Chemotherapeutic agents such as doxorubicin are known to cause or exacerbate cardiovascular cell death when an underlying heart condition is present. However, the mechanism of doxorubicin-induced cardiotoxicity is unclear. Here we assess the cardiotoxic effects of doxorubicin in conditions of myocardial ischaemia reperfusion and the mechanistic basis of protection, in particular the role of the mitochondrial permeability transition pore (mPTP) in such protection. The effects of doxorubicin (1 μM) ± cyclosporine A (CsA, 0.2 μM; inhibits mPTP) were investigated in isolated male Sprague–Dawley rats using Langendorff heart and papillary muscle contraction models subjected to simulated ischaemia and reperfusion injury. Isolated rat cardiac myocytes were used in an oxidative stress model to study the effects of drug treatment on mPTP by confocal microscopy. Western blot analysis evaluated the effects of drug treatment on p-Akt and p-Erk 1/2 levels. Langendorff and the isometric contraction models showed a detrimental effect of doxorubicin throughout reperfusion/reoxygenation as well as increased p-Akt and p-Erk levels. Interestingly, CsA not only reversed the detrimental effects of doxorubicin, but also reduced p-Akt and p-Erk levels. In the sustained oxidative stress assay to study mPTP opening, doxorubicin decreased the time taken to depolarization and hypercontracture, but these effects were delayed in the presence of CsA. Collectively, our data suggest for the first that doxorubicin exacerbates myocardial injury in an ischaemia reperfusion model. If the inhibition of mPTP ameliorates the cardiotoxic effects of doxorubicin, then more selective inhibitors of mPTP should be further investigated for their utility in patients receiving doxorubicin. - Highlights: ► Doxorubicin exacerbates myocardial ischaemia reperfusion injury. ► Co-treatment with CsA protects against doxorubicin induced myocardial injury. ► CsA delays doxorubicin induced mPTP opening in laser

Fourier domain preconditioned conjugate gradient algorithm for atmospheric tomography.

Science.gov (United States)

Yang, Qiang; Vogel, Curtis R; Ellerbroek, Brent L

2006-07-20

By 'atmospheric tomography' we mean the estimation of a layered atmospheric turbulence profile from measurements of the pupil-plane phase (or phase gradients) corresponding to several different guide star directions. We introduce what we believe to be a new Fourier domain preconditioned conjugate gradient (FD-PCG) algorithm for atmospheric tomography, and we compare its performance against an existing multigrid preconditioned conjugate gradient (MG-PCG) approach. Numerical results indicate that on conventional serial computers, FD-PCG is as accurate and robust as MG-PCG, but it is from one to two orders of magnitude faster for atmospheric tomography on 30 m class telescopes. Simulations are carried out for both natural guide stars and for a combination of finite-altitude laser guide stars and natural guide stars to resolve tip-tilt uncertainty.

High serum uric acid levels are a protective factor against unfavourable neurological functional outcome in patients with ischaemic stroke.

Science.gov (United States)

Wang, Yu-Fang; Li, Jiao-Xing; Sun, Xun-Sha; Lai, Rong; Sheng, Wen-Li

2018-05-01

Objective We aimed to evaluate the association between serum uric acid levels at the onset and prognostic outcome in patients with acute ischaemic stroke. Methods We retrospectively analysed the outcomes of 1166 patients with ischaemic stroke who were hospitalized in our centre during August 2008 to November 2012. Correlations of serum uric acid levels and prognostic outcomes were analysed. Results Men had higher serum uric acid levels and better neurological functional outcomes compared with women. There was a strong negative correlation between serum uric acid levels and unfavourable neurological functional outcomes. Generalized estimated equation analysis showed that a higher serum uric acid level (>237 µmol/L) was a protective factor for neurological functional outcome in male, but not female, patients. Among five trial of ORG 10172 in acute stroke treatment classification subtypes, only patients with the large-artery atherosclerosis subtype had a significant protective effect of serum uric acid levels on neurological outcome. Conclusions Our study shows that high serum uric acid levels are a significant protective factor in men and in the large-artery atherosclerosis subtype in patients with ischaemic stroke. This is helpful for determining the prognostic value of serum uric acid levels for neurological outcome of acute ischaemic stroke.

Gene expression analysis to identify molecular correlates of pre- and post-conditioning derived neuroprotection.

Science.gov (United States)

Prasad, Shiv S; Russell, Marsha; Nowakowska, Margeryta; Williams, Andrew; Yauk, Carole

2012-06-01

Mild ischaemic exposures before or after severe injurious ischaemia that elicit neuroprotective responses are referred to as preconditioning and post-conditioning. The corresponding molecular mechanisms of neuroprotection are not completely understood. Identification of the genes and associated pathways of corresponding neuroprotection would provide insight into neuronal survival, potential therapeutic approaches and assessments of therapies for stroke. The objectives of this study were to use global gene expression approach to infer the molecular mechanisms in pre- and post-conditioning-derived neuroprotection in cortical neurons following oxygen and glucose deprivation (OGD) in vitro and then to apply these findings to predict corresponding functional pathways. To this end, microarray analysis was applied to rat cortical neurons with or without the pre- and post-conditioning treatments at 3-h post-reperfusion, and differentially expressed transcripts were subjected to statistical, hierarchical clustering and pathway analyses. The expression patterns of 3,431 genes altered under all conditions of ischaemia (with and without pre- or post-conditioning). We identified 1,595 genes that were commonly regulated within both the pre- and post-conditioning treatments. Cluster analysis revealed that transcription profiles clustered tightly within controls, non-conditioned OGD and neuroprotected groups. Two clusters defining neuroprotective conditions associated with up- and downregulated genes were evident. The five most upregulated genes within the neuroprotective clusters were Tagln, Nes, Ptrf, Vim and Adamts9, and the five most downregulated genes were Slc7a3, Bex1, Brunol4, Nrxn3 and Cpne4. Pathway analysis revealed that the intracellular and second messenger signalling pathways in addition to cell death were predominantly associated with downregulated pre- and post-conditioning associated genes, suggesting that modulation of cell death and signal transduction pathways

Preconditioned characteristic boundary conditions based on artificial compressibility method for solution of incompressible flows

Science.gov (United States)

Hejranfar, Kazem; Parseh, Kaveh

2017-09-01

The preconditioned characteristic boundary conditions based on the artificial compressibility (AC) method are implemented at artificial boundaries for the solution of two- and three-dimensional incompressible viscous flows in the generalized curvilinear coordinates. The compatibility equations and the corresponding characteristic variables (or the Riemann invariants) are mathematically derived and then applied as suitable boundary conditions in a high-order accurate incompressible flow solver. The spatial discretization of the resulting system of equations is carried out by the fourth-order compact finite-difference (FD) scheme. In the preconditioning applied here, the value of AC parameter in the flow field and also at the far-field boundary is automatically calculated based on the local flow conditions to enhance the robustness and performance of the solution algorithm. The code is fully parallelized using the Concurrency Runtime standard and Parallel Patterns Library (PPL) and its performance on a multi-core CPU is analyzed. The incompressible viscous flows around a 2-D circular cylinder, a 2-D NACA0012 airfoil and also a 3-D wavy cylinder are simulated and the accuracy and performance of the preconditioned characteristic boundary conditions applied at the far-field boundaries are evaluated in comparison to the simplified boundary conditions and the non-preconditioned characteristic boundary conditions. It is indicated that the preconditioned characteristic boundary conditions considerably improve the convergence rate of the solution of incompressible flows compared to the other boundary conditions and the computational costs are significantly decreased.

Effects of surgery on ischaemic mitral regurgitation: a prospective multicentre registry (SIMRAM registry)

DEFF Research Database (Denmark)

Lancellotti, P.; Donal, E.; Cosyns, B.

2008-01-01

at rest. Exercise echocardiography may help identify a subset of patients at higher risk of cardiovascular events by revealing the dynamic component of IMR. METHODS: A large prospective, multicentre, non-randomized registry is designed to evaluate the effects of surgery on IMR at rest and on its dynamic......AIMS: Functional ischaemic mitral regurgitation (IMR) is common in patients with ischaemic left ventricular dysfunction undergoing coronary artery bypass surgery. Although the presence of IMR negatively affects prognosis, the additional benefit of valve repair is debated, particularly with mild IMR...... component at exercise (z). SIMRAM will enrol approximately 550 patients with IMR in up to 17 centres with clinical and exercise follow-up for 1 year. Three sets of outcomes will be prospectively assessed and several hypotheses will be tested including determinants of adverse outcome and progressive left...

Early blood glucose profile and neurodevelopmental outcome at two years in neonatal hypoxic-ischaemic encephalopathy.

LENUS (Irish Health Repository)

Nadeem, Montasser

2012-01-31

BACKGROUND: To examine the blood glucose profile and the relationship between blood glucose levels and neurodevelopmental outcome in term infants with hypoxic-ischaemic encephalopathy. METHODS: Blood glucose values within 72 hours of birth were collected from 52 term infants with hypoxic-ischaemic encephalopathy. Hypoglycaemia [< 46.8 mg\\/dL (2.6 mmol\\/L)] and hyperglycaemia [> 150 mg\\/dL (8.3 mmol\\/L)] were correlated to neurodevelopmental outcome at 24 months of age. RESULTS: Four fifths of the 468 blood samples were in the normoglycaemic range (392\\/468:83.8%). Of the remaining 76 samples, 51.3% were in the hypoglycaemic range and (48.7%) were hyperglycaemic. A quarter of the hypoglycaemic samples (28.2%:11\\/39) and a third of the hyperglycaemic samples (32.4%:12\\/37) were recorded within the first 30 minutes of life. Mean (SD) blood glucose values did not differ between infants with normal and abnormal outcomes [4.89(2.28) mmol\\/L and 5.02(2.35) mmol\\/L, p value = 0.15] respectively. In term infants with hypoxic-ischaemic encephalopathy, early hypoglycaemia (between 0-6 hours of life) was associated with adverse outcome at 24 months of age [OR = 5.8, CI = 1.04-32)]. On multivariate analysis to adjust for grade of HIE this association was not statistically significant. Late hypoglycaemia (6-72 hours of life) was not associated with abnormal outcome [OR = 0.22, CI (0.04-1.14)]. The occurrence of hyperglycaemia was not associated with adverse outcome. CONCLUSION: During the first 72 hours of life, blood glucose profile in infants with hypoxic-ischaemic encephalopathy varies widely despite a management protocol. Early hypoglycaemia (0-6 hours of life) was associated with severe HIE, and thereby; adverse outcome.

Early blood glucose profile and neurodevelopmental outcome at two years in neonatal hypoxic-ischaemic encephalopathy

LENUS (Irish Health Repository)

Nadeem, Montasser

2011-02-04

Abstract Background To examine the blood glucose profile and the relationship between blood glucose levels and neurodevelopmental outcome in term infants with hypoxic-ischaemic encephalopathy. Methods Blood glucose values within 72 hours of birth were collected from 52 term infants with hypoxic-ischaemic encephalopathy. Hypoglycaemia [< 46.8 mg\\/dL (2.6 mmol\\/L)] and hyperglycaemia [> 150 mg\\/dL (8.3 mmol\\/L)] were correlated to neurodevelopmental outcome at 24 months of age. Results Four fifths of the 468 blood samples were in the normoglycaemic range (392\\/468:83.8%). Of the remaining 76 samples, 51.3% were in the hypoglycaemic range and (48.7%) were hyperglycaemic. A quarter of the hypoglycaemic samples (28.2%:11\\/39) and a third of the hyperglycaemic samples (32.4%:12\\/37) were recorded within the first 30 minutes of life. Mean (SD) blood glucose values did not differ between infants with normal and abnormal outcomes [4.89(2.28) mmol\\/L and 5.02(2.35) mmol\\/L, p value = 0.15] respectively. In term infants with hypoxic-ischaemic encephalopathy, early hypoglycaemia (between 0-6 hours of life) was associated with adverse outcome at 24 months of age [OR = 5.8, CI = 1.04-32)]. On multivariate analysis to adjust for grade of HIE this association was not statistically significant. Late hypoglycaemia (6-72 hours of life) was not associated with abnormal outcome [OR = 0.22, CI (0.04-1.14)]. The occurrence of hyperglycaemia was not associated with adverse outcome. Conclusion During the first 72 hours of life, blood glucose profile in infants with hypoxic-ischaemic encephalopathy varies widely despite a management protocol. Early hypoglycaemia (0-6 hours of life) was associated with severe HIE, and thereby; adverse outcome.

PRECONDITIONS AND DETERMINING CAUSES OF THE SHADOW ECONOMY IN UKRAINE

Directory of Open Access Journals (Sweden)

Z. Varnalii

2014-03-01

Full Text Available The article analyzes the main processes that led to the high level of the economy shadowing. The historical aspects of the formation of the shadow economy in Ukraine are highlighted. The socio-economic aspects of the shadow economy of Ukraine causality are discussed. The theoretical contribution of foreign and domestic researchers on the preconditions of formation of the shadow economy in transition economies is studied. Theoretical perspective on the factors of the shadowing processes in the economy of Ukraine from the standpoint of modern scientific researches is analyzed. The paper also provides scientific vectors for further development of researches aimed at studying the causes and preconditions of the shadow economy.

GlyT1 Inhibitor NFPS Exerts Neuroprotection via GlyR Alpha1 Subunit in the Rat Model of Transient Focal Cerebral Ischaemia and Reperfusion

Directory of Open Access Journals (Sweden)

Baosheng Huang

2016-05-01

Full Text Available Background/Aims: Glycine is a strychnine-sensitive inhibitory neurotransmitter in the central nervous system (CNS, especially in the spinal cord, brainstem, and retina. The objective of the present study was to investigate the potential neuroprotective effects of GlyT1 inhibitor N [3-(4'-fluorophenyl-3-(4'-phenylphenoxy propyl] sarcosine (NFPS in the rat model of experimental stroke. Methods: In vivo ischaemia was induced by transient middle cerebral artery occlusion (tMCAO. The methods of Western Blotting, Nissl Staining and Morris water maze methods were applied to analyze the anti-ischaemia mechanism. Results: The results showed that high dose of NFPS (H-NFPS significantly reduced infarct volume, neuronal injury and the expression of cleaved caspase-3, enhanced Bcl-2/Bax, and improved spatial learning deficits which were administered three hours after transient middle cerebral artery occlusion (tMCAO induction in rats, while, low dose of NFPS (L-NFPS exacerbated the injury of ischaemia. These findings suggested that low and high dose of NFPS produced opposite effects. Importantly, it was demonstrated that H-NFPS-dependent neuronal protection was inverted by salicylate (Sal, a specific GlyR ɑ1 antagonist. Such effects could probably be attributed to the enhanced glycine level in both synaptic and extrasynaptic clefts and the subsequently altered extrasynaptic GlyRs and their subtypes. Conclusions: These data imply that GlyT1 inhibitor NFPS may be a novel target for clinical treatment of transient focal cerebral ischaemia and reperfusion which are associated with altered GlyR alpha 1 subunits.

A review of methods for assessment of coronary microvascular disease in both clinical and experimental settings

DEFF Research Database (Denmark)

Pries, A.R.; Habazettl, H.; Ambrosio, G.

2008-01-01

-will certainly result in more rational diagnostic and therapeutic interventions for patients with ischaemic heart disease. Specifically targeted research based on improved assessment modalities is needed to improve the diagnosis of CMD and to translate current molecular, cellular, and physiological knowledge......Obstructive disease of the large coronary arteries is the prominent cause for angina pectoris. However, angina may also occur in the absence of significant coronary atherosclerosis or coronary artery spasm, especially in women. Myocardial ischaemia in these patients is often associated...

Parallelizable approximate solvers for recursions arising in preconditioning

Energy Technology Data Exchange (ETDEWEB)

Shapira, Y. [Israel Inst. of Technology, Haifa (Israel)

1996-12-31

For the recursions used in the Modified Incomplete LU (MILU) preconditioner, namely, the incomplete decomposition, forward elimination and back substitution processes, a parallelizable approximate solver is presented. The present analysis shows that the solutions of the recursions depend only weakly on their initial conditions and may be interpreted to indicate that the inexact solution is close, in some sense, to the exact one. The method is based on a domain decomposition approach, suitable for parallel implementations with message passing architectures. It requires a fixed number of communication steps per preconditioned iteration, independently of the number of subdomains or the size of the problem. The overlapping subdomains are either cubes (suitable for mesh-connected arrays of processors) or constructed by the data-flow rule of the recursions (suitable for line-connected arrays with possibly SIMD or vector processors). Numerical examples show that, in both cases, the overhead in the number of iterations required for convergence of the preconditioned iteration is small relatively to the speed-up gained.

Cerebellar cytokine expression in a rat model for fetal asphyctic preconditioning and perinatal asphyxia

DEFF Research Database (Denmark)

Vlassaks, Evi; Brudek, Tomasz; Pakkenberg, Bente

2014-01-01

the effects of perinatal asphyxia and fetal asphyctic preconditioning on the inflammatory cytokine response in the cerebellum. Fetal asphyxia was induced at embryonic day 17 by clamping the uterine vasculature for 30 min. At term birth, global perinatal asphyxia was induced by placing the uterine horns...... was decreased 96 h postfetal asphyxia. When applied as preconditioning stimulus, fetal asphyxia attenuates the cerebellar cytokine response. These results indicate that sublethal fetal asphyxia may protect the cerebellum from perinatal asphyxia-induced damage via inhibition of inflammation.......Asphyctic brain injury is a major cause of neuronal inflammation in the perinatal period. Fetal asphyctic preconditioning has been shown to modulate the cerebral inflammatory cytokine response, hereby protecting the brain against asphyctic injury at birth. This study was designated to examine...

Liver fat content, non-alcoholic fatty liver disease, and ischaemic heart disease

DEFF Research Database (Denmark)

Lauridsen, Bo Kobberø; Stender, Stefan; Kristensen, Thomas Skårup

2018-01-01

Aims: In observational studies, non-alcoholic fatty liver disease (NAFLD) is associated with high risk of ischaemic heart disease (IHD). We tested the hypothesis that a high liver fat content or a diagnosis of NAFLD is a causal risk factor for IHD. Methods and results: In a cohort study...

Protein supplementation may enhance the spontaneous recovery of neurological alterations in patients with ischaemic stroke.

Science.gov (United States)

Aquilani, Roberto; Scocchi, Marco; Iadarola, Paolo; Franciscone, Piero; Verri, Manuela; Boschi, Federica; Pasini, Evasio; Viglio, Simona

2008-12-01

To determine whether protein supplementation could enhance neurological recovery in subacute patients with ischaemic stroke. Alimentation-independent patients with ischaemic stroke were randomly allocated to either 21 days of protein supplementation (protein-supplemented group; n=20) or to a spontaneous diet only (control group; n=21) in order to investigate the recovery of neurological changes (measured using the National Institute of Health (NIH) Stroke Scale). Tertiary care rehabilitation in Italy. Forty-two patients (27 male and 15 female; 66.4 +/- 11 years) 16 +/-2 days after the acute event. Supplementation with a hyperproteic nutritional formula (10% protein). NIH Stroke Scale and protein intake. At admission to rehabilitation, both groups of patients were homogeneous for demographic, clinical and functional characteristics. After 21 days from the start of the protocol, the NIH Stroke Scale was found to be enhanced in the group with supplemental proteins (-4.4 +/- 1.5 score versus -3 +/- 1.4 of control group; P<0.01). When expressed as difference (triangle up) between baseline and 21 days, the NIH Stroke Scale correlated negatively with change in protein intake (g/day) (r=-0.50, P= 0.001) and positively with change in carbohydrate/protein ratio (r = +0.40, P=0.01) Protein supplementation may enhance neurological recovery in subacute patients with ischaemic stroke.

Preserved cardiac mitochondrial function and reduced ischaemia/reperfusion injury afforded by chronic continuous hypoxia: Role of opioid receptors

Czech Academy of Sciences Publication Activity Database

Maslov, L. N.; Naryzhnaya, N. V.; Prokudina, E. S.; Kolář, František; Gorbunov, A. S.; Zhang, Y.; Wang, H.; Tsibulnikov, S.Yu.; Portnichenko, A. G.; Lasukova, T. V.; Lishmanov, Yu. B.

2015-01-01

Roč. 42, č. 5 (2015), s. 496-501 ISSN 1440-1681 R&D Projects: GA ČR(CZ) GAP303/12/1162 Institutional support: RVO:67985823 Keywords : cardioprotection * chronic hypoxia * ischaemia/reperfusion * mitochondrial function * opioid receptors Subject RIV: ED - Physiology Impact factor: 2.004, year: 2015

Ischaemic stroke management at Al-Shifa Hospital in the Gaza Strip: a clinical audit.

Science.gov (United States)

Abukaresh, Amir; Al-Abadlah, Rami; Böttcher, Bettina; El-Essi, Khamis

2018-02-21

In the 2014 Palestinian annual health report, cerebrovascular accident was ranked as the third leading cause of death in the occupied Palestinian territory. Cerebrovascular accident is also one the most common causes of disability worldwide. Good management decreases mortality and morbidity. The aim of this study was to assess the current management of patients with ischaemic stroke at the Al-Shifa Hospital and to compare this with international guidelines. For this clinical audit, we used simple random sampling to select files of patients admitted with the diagnosis of ischaemic stroke to the Al-Shifa Hospital. Data collection sheets were completed, and clinical practice was compared with the 2013 American Stroke Association guidelines. Between January and June, 2016, 254 patients were admitted with ischaemic stroke, haemorrhagic stroke, or transient ischaemic attack. We selected 55 patient files. The International Classification of Diseases coding for cerebral infarction in patient files was relatively good, with 92% of files correctly coded. However, we found a substantial weakness in the documentation of duration, progression of symptoms (documented in 20% of files only), and physiotherapy assessment. Most essential acute investigations were done on time (for all [100%] patients needing blood count, renal function tests, and CT scan and for 42 [76%] patients needing ECG). However, thrombolytic drugs were not used because they were not available. Long-term antiplatelet therapy was provided properly to 51 (92%) patients discharged from hospital. However, the initial doses of antiplatelet therapy were generally lower than the international recommendations. Findings also showed a marked inconformity of blood pressure management, especially with respect to the treatment decision and the choice of antihypertensive drug. No local guidelines exist. Furthermore, the lack of availability of thrombolysis medication and the poor deviation in blood pressure management show

Preconditioned conjugate-gradient methods for low-speed flow calculations

Science.gov (United States)

Ajmani, Kumud; Ng, Wing-Fai; Liou, Meng-Sing

1993-01-01

An investigation is conducted into the viability of using a generalized Conjugate Gradient-like method as an iterative solver to obtain steady-state solutions of very low-speed fluid flow problems. Low-speed flow at Mach 0.1 over a backward-facing step is chosen as a representative test problem. The unsteady form of the two dimensional, compressible Navier-Stokes equations is integrated in time using discrete time-steps. The Navier-Stokes equations are cast in an implicit, upwind finite-volume, flux split formulation. The new iterative solver is used to solve a linear system of equations at each step of the time-integration. Preconditioning techniques are used with the new solver to enhance the stability and convergence rate of the solver and are found to be critical to the overall success of the solver. A study of various preconditioners reveals that a preconditioner based on the Lower-Upper Successive Symmetric Over-Relaxation iterative scheme is more efficient than a preconditioner based on Incomplete L-U factorizations of the iteration matrix. The performance of the new preconditioned solver is compared with a conventional Line Gauss-Seidel Relaxation (LGSR) solver. Overall speed-up factors of 28 (in terms of global time-steps required to converge to a steady-state solution) and 20 (in terms of total CPU time on one processor of a CRAY-YMP) are found in favor of the new preconditioned solver, when compared with the LGSR solver.

Preconditioned Conjugate Gradient methods for low speed flow calculations

Science.gov (United States)

Ajmani, Kumud; Ng, Wing-Fai; Liou, Meng-Sing

1993-01-01

An investigation is conducted into the viability of using a generalized Conjugate Gradient-like method as an iterative solver to obtain steady-state solutions of very low-speed fluid flow problems. Low-speed flow at Mach 0.1 over a backward-facing step is chosen as a representative test problem. The unsteady form of the two dimensional, compressible Navier-Stokes equations are integrated in time using discrete time-steps. The Navier-Stokes equations are cast in an implicit, upwind finite-volume, flux split formulation. The new iterative solver is used to solve a linear system of equations at each step of the time-integration. Preconditioning techniques are used with the new solver to enhance the stability and the convergence rate of the solver and are found to be critical to the overall success of the solver. A study of various preconditioners reveals that a preconditioner based on the lower-upper (L-U)-successive symmetric over-relaxation iterative scheme is more efficient than a preconditioner based on incomplete L-U factorizations of the iteration matrix. The performance of the new preconditioned solver is compared with a conventional line Gauss-Seidel relaxation (LGSR) solver. Overall speed-up factors of 28 (in terms of global time-steps required to converge to a steady-state solution) and 20 (in terms of total CPU time on one processor of a CRAY-YMP) are found in favor of the new preconditioned solver, when compared with the LGSR solver.

Preconditioned conjugate gradient methods for the Navier-Stokes equations

Science.gov (United States)

Ajmani, Kumud; Ng, Wing-Fai; Liou, Meng-Sing

1994-01-01

A preconditioned Krylov subspace method (GMRES) is used to solve the linear systems of equations formed at each time-integration step of the unsteady, two-dimensional, compressible Navier-Stokes equations of fluid flow. The Navier-Stokes equations are cast in an implicit, upwind finite-volume, flux-split formulation. Several preconditioning techniques are investigated to enhance the efficiency and convergence rate of the implicit solver based on the GMRES algorithm. The superiority of the new solver is established by comparisons with a conventional implicit solver, namely line Gauss-Seidel relaxation (LGSR). Computational test results for low-speed (incompressible flow over a backward-facing step at Mach 0.1), transonic flow (trailing edge flow in a transonic turbine cascade), and hypersonic flow (shock-on-shock interactions on a cylindrical leading edge at Mach 6.0) are presented. For the Mach 0.1 case, overall speedup factors of up to 17 (in terms of time-steps) and 15 (in terms of CPU time on a CRAY-YMP/8) are found in favor of the preconditioned GMRES solver, when compared with the LGSR solver. The corresponding speedup factors for the transonic flow case are 17 and 23, respectively. The hypersonic flow case shows slightly lower speedup factors of 9 and 13, respectively. The study of preconditioners conducted in this research reveals that a new LUSGS-type preconditioner is much more efficient than a conventional incomplete LU-type preconditioner.

l-arginine and l-NMMA for assessing cerebral endothelial dysfunction in ischaemic cerebrovascular disease

DEFF Research Database (Denmark)

Karlsson, William K; Sørensen, Caspar G; Kruuse, Christina

2017-01-01

Endothelial dysfunction (ED), in particular cerebral ED, may be an essential biomarker for ischaemic cerebrovascular disease. However, there is no consensus on methods to best estimate cerebral ED. In this systematic review, we evaluate the use of l-arginine and NG -monomethyl-l-arginine (l......-NMMA) for assessment of cerebral ED. A systematic search of PubMed, EMBASE and the Cochrane Library was done. We included studies investigating cerebrovascular response to l-arginine or l-NMMA in human subjects with vascular risk factors or ischaemic cerebrovascular disease. Seven studies (315 subjects) were eligible...... cerebrovascular disease. Inconsistencies in results were most likely due to variations in methods and included subject populations. In order to use cerebral ED as a prognostic marker, further studies are required to evaluate the association to cerebrovascular disease....

Association of Exercise Preconditioning With Immediate Cardioprotection: A Review.

NARCIS (Netherlands)

Thijssen, D.H.J.; Redington, A.; George, K.P.; Hopman, M.T.E.; Jones, H.

2018-01-01

Importance: Exercise reduces the risk of cardiovascular events, including through an underrecognized, clinically useful form of acute cardioprotection accessible after a single episode of exercise, which is called cardiovascular preconditioning. Observations: Preclinical evidence shows that 1 to 3

Using Chebyshev polynomials and approximate inverse triangular factorizations for preconditioning the conjugate gradient method

Science.gov (United States)

Kaporin, I. E.

2012-02-01

In order to precondition a sparse symmetric positive definite matrix, its approximate inverse is examined, which is represented as the product of two sparse mutually adjoint triangular matrices. In this way, the solution of the corresponding system of linear algebraic equations (SLAE) by applying the preconditioned conjugate gradient method (CGM) is reduced to performing only elementary vector operations and calculating sparse matrix-vector products. A method for constructing the above preconditioner is described and analyzed. The triangular factor has a fixed sparsity pattern and is optimal in the sense that the preconditioned matrix has a minimum K-condition number. The use of polynomial preconditioning based on Chebyshev polynomials makes it possible to considerably reduce the amount of scalar product operations (at the cost of an insignificant increase in the total number of arithmetic operations). The possibility of an efficient massively parallel implementation of the resulting method for solving SLAEs is discussed. For a sequential version of this method, the results obtained by solving 56 test problems from the Florida sparse matrix collection (which are large-scale and ill-conditioned) are presented. These results show that the method is highly reliable and has low computational costs.

Comparison of the mass preconditioned HMC and the DD-HMC algorithm for two-flavour QCD

CERN Document Server

Marinkovic, Marina

2010-01-01

Mass preconditioned HMC and DD-HMC are among the most popular algorithms to simulate Wilson fermions. We present a comparison of the performance of the two algorithms for realistic quark masses and lattice sizes. In particular, we use the locally deflated solver of the DD-HMC environment also for the mass preconditioned simulations.

A meta-analysis of intraoperative factors associated with ...

African Journals Online (AJOL)

... 95% 1.9-26), new onset atrial fibrillation (OR 6.6, 95% CI 2.5-20), hypothermia (OR 2.2, 95% CI 1.1-5) and remote ischaemic preconditioning (OR 0.22, 95% CI 0.07-0.67). None of these studies controlled for blood transfusion. Conclusion: Both surgical and haemodynamic intraoperative events significantly increased the ...

Develop and implement preconditioning techniques to control face ejection rockbursts for safer mining in seismically hazardous areas

CSIR Research Space (South Africa)

Toper, AZ

1998-01-01

Full Text Available This research report discusses the development of preconditioning techniques to control face bursts, for safer mining in seismically hazardous areas. Preconditioning involves regularly setting off carefully tailored blasts in the fractured rock...

Flow motion waves with high and low frequency in severe ischaemia before and after percutaneous transluminal angioplasty.

Science.gov (United States)

Hoffmann, U; Schneider, E; Bollinger, A

1990-09-01

STUDY OF OBJECTIVE: The aim was to evaluate skin flux and prevalence of low and high frequency flow motion waves in patients with severe ischaemia due to peripheral arterial occlusive disease before and after percutaneous transluminal angioplasty (PTA) with and without local thrombolysis. Flow motion was recorded by the laser Doppler technique at the dorsum of the foot before, one day, and one month after PTA. The results were separately analysed in patients with successful and unsuccessful treatment. 18 patients with rest pain or incipient gangrene were included. Mean pretreatment systolic ankle pressure was 55.8(SD 25.5) mm Hg, and mean transcutaneous PO2 at 43 degrees C was 5.2(9.4) mm Hg. Arteriography revealed relevant stenoses or occlusions of the femoropopliteal and calf arteries. Before treatment two patterns of flow motion with characteristic frequency ranges were observed at the foot dorsum and at a probe temperature of 32 degrees C: low frequency (LF) waves with a mean frequency of 2.2(0.5) cycles.min-1 and a mean amplitude of 0.73(0.42) arbitrary units (AU) and high frequency (HF) waves with a mean frequency of 22.6(4.2) cycles.min-1 and a mean amplitude of 0.39(0.33) AU. PTA was successful in 11 of the 18 patients. After successful treatment, prevalence of HF waves decreased from 10/11 to 4/11 cases (p less than 0.001), but remained nearly unchanged after failed procedure. Prevalence of LF waves before and after PTA did not differ significantly. Our data support the hypothesis that HF waves represent a reaction of skin microcirculation to severe ischaemia. With reference to animal studies it is proposed that HF waves originate from terminal arterioles. They may function as a compensatory mechanism of flow regulation involved in pathophysiology of ischaemia.

MRI assessment of cerebral blood volume in patients with brain infarcts

International Nuclear Information System (INIS)

Wu, R.H.; Bruening, R.; Berchtenbreiter, C.; Weber, J.; Peller, M.; Penzkofer, H.; Reiser, M.; Steiger, H.J.

1998-01-01

MRI perfusion studies have focussed mainly on acute ischaemia and characterisation in ischaemia. Our purpose was to analyse regional brain haemodynamic information in acute, subacute, and chronic ischaemia. We performed 16 examinations of 11 patients on a 1.5 T MR images. Conventional and dynamic contrast-enhanced imaging were employed in all examinations. For the dynamic susceptibility sequences, a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. Reconstructed regional relative cerebral blood volume (rCBV) maps, bolus maps, and conventional images were analysed by consensus reading. In all examinations decreases in rCBV were observed in the lesions. The distribution of regional rCBV in lesions was heterogeneous. The rCBV of the periphery of the lesions was higher than that at their center. There was a correlation between the time since onset and abnormalities on the rCBV map and T2-weighted images (T2WI). In the early stage of acute stroke, the abnormalities tended to be larger on the rCBV than on T2WI. Many patterns of bolus passage were observed in ischaemic regions. rCBV maps provide additional haemodynamic information in patients with brain infarcts. (orig.)

Hypoperfusion Induced by Preconditioning Treadmill Training in Hyper-Early Reperfusion After Cerebral Ischemia: A Laser Speckle Imaging Study.

Science.gov (United States)

He, Zhijie; Lu, Hongyang; Yang, Xiaojiao; Zhang, Li; Wu, Yi; Niu, Wenxiu; Ding, Li; Wang, Guili; Tong, Shanbao; Jia, Jie

2018-01-01

Exercise preconditioning induces neuroprotective effects during cerebral ischemia and reperfusion, which involves the recovery of cerebral blood flow (CBF). Mechanisms underlying the neuroprotective effects of re-established CBF following ischemia and reperfusion are unclear. The present study investigated CBF in hyper-early stage of reperfusion by laser speckle contrast imaging, a full-field high-resolution optical imaging technique. Rats with or without treadmill training were subjected to middle cerebral artery occlusion followed by reperfusion. CBF in arteries, veins, and capillaries in hyper-early stage of reperfusion (1, 2, and 3 h after reperfusion) and in subacute stage (24 h after reperfusion) were measured. Neurological scoring and 2,3,5-triphenyltetrazolium chloride staining were further applied to determine the neuroprotective effects of exercise preconditioning. In hyper-early stage of reperfusion, CBF in the rats with exercise preconditioning was reduced significantly in arteries and veins, respectively, compared to rats with no exercise preconditioning. Capillary CBF remained stable in the hyper-early stage of reperfusion, though it increased significantly 24 h after reperfusion in the rats with exercise preconditioning. As a neuroprotective strategy, exercise preconditioning reduced the blood perfusion of arteries and veins in the hyper-early stage of reperfusion, which indicated intervention-induced neuroprotective hypoperfusion after reperfusion onset.

Manipulation in political stock markets: Preconditions and evidence

OpenAIRE

Hansen, Jan; Schmidt, Carsten; Strobel, Martin

2001-01-01

Political stock markets (PSM) are sometimes seen as substitutes for opinion polls. On the bases of a behavioral model, specific preconditions were drawn out under which manipulation in PSM can weaken this argument. Evidence for manipulation is reported from the data of two separate PSM during the Berlin 99 state elections.

HMC algorithm with multiple time scale integration and mass preconditioning

Science.gov (United States)

Urbach, C.; Jansen, K.; Shindler, A.; Wenger, U.

2006-01-01

We present a variant of the HMC algorithm with mass preconditioning (Hasenbusch acceleration) and multiple time scale integration. We have tested this variant for standard Wilson fermions at β=5.6 and at pion masses ranging from 380 to 680 MeV. We show that in this situation its performance is comparable to the recently proposed HMC variant with domain decomposition as preconditioner. We give an update of the "Berlin Wall" figure, comparing the performance of our variant of the HMC algorithm to other published performance data. Advantages of the HMC algorithm with mass preconditioning and multiple time scale integration are that it is straightforward to implement and can be used in combination with a wide variety of lattice Dirac operators.

Comparison of the effects of isobutylmethylxanthine and milrinone on ischaemia-induced arrhythmias and platelet aggregation in anaesthetized rabbits.

Science.gov (United States)

Holbrook, M.; Coker, S. J.

1989-01-01

1. The aim of this study was to compare the effects of the non-selective phosphodiesterase (PDE) inhibitor, isobutylmethylxanthine (IBMX) and the selective PDE III inhibitor, milrinone, in a rabbit model of acute myocardial ischaemia. 2. Coronary artery occlusion caused changes in the ST-segment of the ECG and ectopic activity in all control rabbits. Ventricular fibrillation occurred in 10 out of 14 (71%) of these animals. Pretreatment with IBMX 100 micrograms kg-1 plus 10 micrograms kg-1 min-1, starting 10 min before coronary artery occlusion, reduced ischaemia-induced ST-segment changes and ventricular fibrillation occurred in only 10% of this group (n = 10). A similar dose of milrinone had no antiarrhythmic activity, whereas with a lower dose of milrinone, 30 micrograms kg-1 plus 3 micrograms kg-1 min-1 (n = 10), only 30% of rabbits fibrillated and ST-segment changes were attenuated. 3. Acute administration of both IBMX and milrinone reduced arterial blood pressure. With the higher dose of milrinone a significant effect was still present after 10 min of drug infusion. A greater hypotensive response to the higher dose of milrinone was observed in the rabbits which subsequently fibrillated during ischaemia. A marked tachycardia was also observed after administration of the higher dose of milrinone. 4. At the end of the experiment platelet aggregation was studied ex vivo. ADP-induced aggregation was reduced by pretreatment of the rabbits with milrinone but not IBMX. Both PDE inhibitors enhanced the ability of isoprenaline to inhibit ADP-induced platelet aggregation but milrinone was more effective, particularly at the higher dose.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2478245

Clinical patterns and outcomes of ischaemic colitis: results of the Working Group for the Study of Ischaemic Colitis in Spain (CIE study).

Science.gov (United States)

Montoro, Miguel A; Brandt, Lawrence J; Santolaria, Santos; Gomollon, Fernando; Sánchez Puértolas, Belén; Vera, Jesús; Bujanda, Luis; Cosme, Angel; Cabriada, José Luis; Durán, Margarita; Mata, Laura; Santamaría, Ana; Ceña, Gloria; Blas, Jose Manuel; Ponce, Julio; Ponce, Marta; Rodrigo, Luis; Ortiz, Jacobo; Muñoz, Carmen; Arozena, Gloria; Ginard, Daniel; López-Serrano, Antonio; Castro, Manuel; Sans, Miquel; Campo, Rafael; Casalots, Alex; Orive, Víctor; Loizate, Alberto; Titó, Lluçia; Portabella, Eva; Otazua, Pedro; Calvo, M; Botella, Maria Teresa; Thomson, Concepción; Mundi, Jose Luis; Quintero, Enrique; Nicolás, David; Borda, Fernando; Martinez, Benito; Gisbert, Javier P; Chaparro, María; Jimenez Bernadó, Alfredo; Gómez-Camacho, Federico; Cerezo, Antonio; Casal Nuñez, Enrique

2011-02-01

There is a lack of prospective studies evaluating the natural history of colonic ischaemia (CI). We performed such a study to evaluate the clinical presentation, outcome, and mortality as well as clinical variables associated with poor prognosis. An open, prospective, and multicentre study was conducted in 24 Spanish hospitals serving a population of 3.5 million people. The study included only patients who met criteria for definitive or probable CI. A website (www.colitisisquemica.org) provided logistical support. A total of 364 patients met criteria for inclusion. CI was suspected clinically in only 24.2% of cases. The distribution of clinical patterns was as follows: reversible colopathy (26.1%), transient colitis (43.7%), gangrenous colitis (9.9%), fulminant pancolitis (2.5%), and chronic segmental colitis (17.9%). A total of 47 patients (12.9%) had an unfavorable outcome as defined by mortality and/or the need for surgery. Multivariate analysis identified the following signs as independent risk factors for an unfavorable outcome: abdominal pain without rectal bleeding [odds ratio (OR) 3.9; 95% confidence interval (CI) = 1.6-9.3], non-bloody diarrhoea (OR 10; 95% CI = 3.7-27.4), and peritoneal signs (OR 7.3; 95% CI = 2.7-19.6). Unfavorable outcomes also were more frequent in isolated right colon ischaemia (IRCI) compared with non-IRCI (40.9 vs. 10.3%, respectively; p < 0.0001). The overall mortality rate was 7.7%. The clinical presentation of CI is very heterogeneous, perhaps explaining why clinical suspicion of this disease is so low. The presence of IRCI, and occurrence of peritoneal signs or onset of CI as severe abdominal pain without bleeding, should alert the physician to a potentially unfavorable course.

Morphine Preconditioning Downregulates MicroRNA-134 Expression Against Oxygen-Glucose Deprivation Injuries in Cultured Neurons of Mice.

Science.gov (United States)

Meng, Fanjun; Li, Yan; Chi, Wenying; Li, Junfa

2016-07-01

Brain protection by narcotics such as morphine is clinically relevant due to the extensive use of narcotics in the perioperative period. Morphine preconditioning induces neuroprotection in neurons, but it remains uncertain whether microRNA-134 (miR-134) is involved in morphine preconditioning against oxygen-glucose deprivation-induced injuries in primary cortical neurons of mice. The present study examined this issue. After cortical neurons of mice were cultured in vitro for 6 days, the neurons were transfected by respective virus vector, such as lentiviral vector (LV)-miR-control-GFP, LV-pre-miR-134-GFP, LV-pre-miR-134-inhibitor-GFP for 24 hours; after being normally cultured for 3 days again, morphine preconditioning was performed by incubating the transfected primary neurons with morphine (3 μM) for 1 hour, and then neuronal cells were exposed to oxygen-glucose deprivation (OGD) for 1 hour and oxygen-glucose recovery for 12 hours. The neuronal cells survival rate and the amount of apoptotic neurons were determined by MTT assay or TUNEL staining at designated time; and the expression levels of miR-134 were detected using real-time reverse transcription polymerase chain reaction at the same time. The neuronal cell survival rate was significantly higher, and the amount of apoptotic neurons was significantly decreased in neurons preconditioned with morphine before OGD than that of OGD alone. The neuroprotection induced by morphine preconditioning was partially blocked by upregulating miR-134 expression, and was enhanced by downregulating miR-134 expression. The expression of miR-134 was significantly decreased in morphine-preconditioned neurons alone without transfection. By downregulating miR-134 expression, morphine preconditioning protects primary cortical neurons of mice against injuries induced by OGD.

Enhanced ex vivo inhibition of platelet function following addition of dipyridamole to aspirin after transient ischaemic attack or ischaemic stroke: first results from the TRinity AntiPlatelet responsiveness (TrAP) study.

LENUS (Irish Health Repository)

Tobin, William Oliver

2012-02-01

Ex vivo dipyridamole \\'non-responsiveness\\' has not been extensively studied in ischaemic cerebrovascular disease. Platelet surface marker expression, leucocyte-platelet complex formation and inhibition of platelet function at high shear stress as detected by the PFA-100(R) Collagen-Adenosine-diphosphate (C-ADP) and Collagen-Epinephrine cartridges was assessed in 52 patients within 4 weeks of transient ischaemic attack (TIA) or ischaemic stroke on aspirin, and then 14 d (14 d) and >90 d (90 d) after adding dipyridamole. A novel definition of \\'Dipyridamole non-responsiveness\\' was used. The median C-ADP closure time increased following addition of dipyridamole, remained elevated at 90 d (P <\\/= 0.03), and was unaffected by aspirin dose. 59% at 14 d and 56% at 90 d were \\'dipyridamole non-responders\\' on the PFA-100. The proportion of non-responders at 14 and 90 d was similar (P= 0.9). Compared with baseline (4.6%), median monocyte-platelet complexes increased at 14 d (5.0%, P= 0.03) and 90 d (4.9%, P= 0.04). Low C-ADP closure times were associated with increased monocyte-platelet complexes at 14 d (r= -0.32, P= 0.02) and 90 d (r= -0.33, P = 0.02). Monocyte-platelet complexes increased in the subgroup of dipyridamole non-responders on the PFA-100 (P<\\/= 0.045), but not in responders (P >\\/= 0.5), at 14 and 90 d versus baseline. Additional inhibition of platelet function has been detected with the PFA-100 when dipyridamole is added to aspirin. Elevated monocyte-platelet complexes may contribute to ex vivo dipyridamole non-responsiveness.

Nonarteritic anterior ischaemic optic neuropathy in Addison's disease.

Science.gov (United States)

Ross, A H; Haider, S; Bailey, C C

2010-10-01

To report three cases of Nonarteritic anterior ischaemic optic neuropathy (NAAION) in patients with Addison's disease. We present a retrospective review of patients presenting with NAAION with underlying Addison's disease. Three eyes of two young patients presented with NAAION. Both patients had underlying Addison's disease with episodes of prolonged hypotension. To our knowledge, this is the first published report of NAAION associated with Addison's disease. As hypotension may be one of the few situations, in which NAAION may be treatable and the visual loss reversible, it is important to recognize and treat sustained episodes of hypotension in these individuals.

Psychological preconditions of game activity development in the early childhood

OpenAIRE

Valeriya Spitsyna; Ekaterina Saraykina

2013-01-01

The article is devoted for detection the psychological preconditions of game activity development at early age and interrelation of game formation with the development of subject actions, informative activity and procedural game.

Curved reformat of the paediatric brain MRI into a 'flat-earth map' - standardised method for demonstrating cortical surface atrophy resulting from hypoxic-ischaemic encephalopathy

International Nuclear Information System (INIS)

Simpson, Ewan; Andronikou, Savvas; Vedajallam, Schadie; Chacko, Anith; Thai, Ngoc Jade

2016-01-01

Hypoxic-ischaemic encephalopathy is optimally imaged with brain MRI in the neonatal period. However neuroimaging is often also performed later in childhood (e.g., when parents seek compensation in cases of alleged birth asphyxia). We describe a standardised technique for creating two curved reconstructions of the cortical surface to show the characteristic surface changes of hypoxic-ischaemic encephalopathy in children imaged after the neonatal period. The technique was applied for 10 cases of hypoxic-ischaemic encephalopathy and also for age-matched healthy children to assess the visibility of characteristic features of hypoxic-ischaemic encephalopathy. In the abnormal brains, fissural or sulcal widening was seen in all cases and ulegyria was identifiable in 7/10. These images could be used as a visual aid for communicating MRI findings to clinicians and other interested parties. (orig.)

Curved reformat of the paediatric brain MRI into a 'flat-earth map' - standardised method for demonstrating cortical surface atrophy resulting from hypoxic-ischaemic encephalopathy

Energy Technology Data Exchange (ETDEWEB)

Simpson, Ewan [Bristol Royal Hospital for Children, Department of Pediatric Radiology, Bristol (United Kingdom); Andronikou, Savvas [Bristol Royal Hospital for Children, Department of Pediatric Radiology, Bristol (United Kingdom); University of Bristol, CRICBristol, Bristol (United Kingdom); Vedajallam, Schadie; Chacko, Anith; Thai, Ngoc Jade [University of Bristol, CRICBristol, Bristol (United Kingdom)

2016-09-15

Hypoxic-ischaemic encephalopathy is optimally imaged with brain MRI in the neonatal period. However neuroimaging is often also performed later in childhood (e.g., when parents seek compensation in cases of alleged birth asphyxia). We describe a standardised technique for creating two curved reconstructions of the cortical surface to show the characteristic surface changes of hypoxic-ischaemic encephalopathy in children imaged after the neonatal period. The technique was applied for 10 cases of hypoxic-ischaemic encephalopathy and also for age-matched healthy children to assess the visibility of characteristic features of hypoxic-ischaemic encephalopathy. In the abnormal brains, fissural or sulcal widening was seen in all cases and ulegyria was identifiable in 7/10. These images could be used as a visual aid for communicating MRI findings to clinicians and other interested parties. (orig.)

Health care in patients 1 year post-stroke in general practice : research on the utilisation of the Dutch Transmural Protocol transient ischaemic attack/cerebrovascular accident

NARCIS (Netherlands)

de Weerd, L.; Rutgers, A.W.F.; Groenier, K.H.; van der Meer, K.

2012-01-01

This study evaluates the kind of aftercare that ischaemic stroke patients receive and the extent that aftercare fulfils the criteria of the 'Dutch Transmural Protocol transient ischaemic attack/cerebrovascular accident'. Fifty-seven patients were interviewed 1 year post-stroke about secondary

Suboptimal lipid management before and after ischaemic stroke and TIA-the North Dublin Population Stroke Study.

Science.gov (United States)

Ní Chróinín, Danielle; Ní Chróinín, Chantelle; Akijian, Layan; Callaly, Elizabeth L; Hannon, Niamh; Kelly, Lisa; Marnane, Michael; Merwick, Áine; Sheehan, Órla; Horgan, Gillian; Duggan, Joseph; Kyne, Lorraine; Dolan, Eamon; Murphy, Seán; Williams, David; Kelly, Peter J

2018-01-24

Few population-based studies have assessed lipid adherence to international guidelines for primary and secondary prevention in stroke/transient ischaemic attack (TIA) patients. This study aims to evaluate adherence to lipid-lowering therapy (LLT) guidelines amongst patients with ischaemic stroke/TIA. Using hot and cold pursuit methods from multiple hospital/community sources, all stroke and TIA cases in North Dublin City were prospectively ascertained over a 1-year period. Adherence to National Cholesterol Education Programme (NCEP) III guidelines, before and after index ischaemic stroke/TIA, was assessed. Amongst 616 patients (428 ischaemic stroke, 188 TIA), total cholesterol was measured following the qualifying event in 76.5% (471/616) and low-density lipoprotein (LDL) in 60.1% (370/616). At initial stroke/TIA presentation, 54.1% (200/370) met NCEP III LDL goals. Compliance was associated with prior stroke (odds ratio [OR] 2.19, p = 0.02), diabetes (OR 1.91, p = 0.04), hypertension (OR 1.57, p = 0.03), atrial fibrillation (OR 1.78, p = 0.01), pre-event LLT (OR 2.85, p TIA onset, 32.7% (195/596) was on LLT. Nonetheless, LDL exceeded individual NCEP goal in 29.2% (56/192); 21.6% (53/245) warranting LLT was not on treatment prior to stroke/TIA onset. After index stroke/TIA, 75.9% (422/556) was on LLT; 15.3% (30/196) meeting NCEP III criteria was not prescribed a statin as recommended. By 2 years, actuarial survival was 72.8% and 11.9% (59/497) experienced stroke recurrence. No association was observed between initial post-event target adherence and 2-year outcomes. In this population-based study, LLT recommended by international guidelines was under-used, before and after index stroke/TIA. Strategies to improve adherence are needed.

Multimodal predictor of neurodevelopmental outcome in newborns with hypoxic-ischaemic encephalopathy.

Science.gov (United States)

Temko, Andriy; Doyle, Orla; Murray, Deirdre; Lightbody, Gordon; Boylan, Geraldine; Marnane, William

2015-08-01

Automated multimodal prediction of outcome in newborns with hypoxic-ischaemic encephalopathy is investigated in this work. Routine clinical measures and 1h EEG and ECG recordings 24h after birth were obtained from 38 newborns with different grades of HIE. Each newborn was reassessed at 24 months to establish their neurodevelopmental outcome. A set of multimodal features is extracted from the clinical, heart rate and EEG measures and is fed into a support vector machine classifier. The performance is reported with the statistically most unbiased leave-one-patient-out performance assessment routine. A subset of informative features, whose rankings are consistent across all patients, is identified. The best performance is obtained using a subset of 9 EEG, 2h and 1 clinical feature, leading to an area under the ROC curve of 87% and accuracy of 84% which compares favourably to the EEG-based clinical outcome prediction, previously reported on the same data. The work presents a promising step towards the use of multimodal data in building an objective decision support tool for clinical prediction of neurodevelopmental outcome in newborns with hypoxic-ischaemic encephalopathy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intraabdominal knoglenydannelse – heterotop mesenteriel ossifikation

DEFF Research Database (Denmark)

Nerup, Nikolaj; Hansen, Philip; Gocht-Jensen, Peter

2014-01-01

Calcified bowel mesentery – heterotopic mesenteric ossification A 64-year-old man suffered blunt abdominal trauma. He developed ischaemic colon and had a colectomy with primary anastomosis, complicated with anastomotic leakage. A temporary stoma was created. Six months later when the stoma...... was to be reversed, the bowel mesentery was found to be extensively calcified. Heterotopic mesenteric ossification is an extremely rare condition. The pathogenesis is unknown but associated with mesenteric ischaemia, generalised peritonitis or abdominal trauma. Treatment should be as conservative as possible...

Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring

DEFF Research Database (Denmark)

Horn, J; Naylor, A R; Laman, D M

2005-01-01

Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated....

Myocardial ischaemia following cocaine and adrenaline exposure in a child during an ophthalmological procedure.

LENUS (Irish Health Repository)

McGovern, E

2015-03-01

We report a 23-month old girl who presented with bilateral epiphora who underwent bilateral lacrimal probing and syringing, during which a cocaine adrenaline solution was used. Two hours after the procedure she developed acute pulmonary oedema secondary to myocardial ischaemia. The patient was treated with intravenous glyceryltrinitrate and milrinone infusions; cardiac enzymes and left ventricular function normalised over the subsequent 72 hours. Topical administration of cocaine and adrenaline solution may have dangerous systemic cardiac effects and should always be used judiciously.

Analysis of a Lipid/Polymer Membrane for Bitterness Sensing with a Preconditioning Process

Directory of Open Access Journals (Sweden)

Rui Yatabe

2015-09-01

Full Text Available It is possible to evaluate the taste of foods or medicines using a taste sensor. The taste sensor converts information on taste into an electrical signal using several lipid/polymer membranes. A lipid/polymer membrane for bitterness sensing can evaluate aftertaste after immersion in monosodium glutamate (MSG, which is called “preconditioning”. However, we have not yet analyzed the change in the surface structure of the membrane as a result of preconditioning. Thus, we analyzed the change in the surface by performing contact angle and surface zeta potential measurements, Fourier transform infrared spectroscopy (FTIR, X-ray photon spectroscopy (XPS and gas cluster ion beam time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS. After preconditioning, the concentrations of MSG and tetradodecylammonium bromide (TDAB, contained in the lipid membrane were found to be higher in the surface region than in the bulk region. The effect of preconditioning was revealed by the above analysis methods.

Preconditions for Emergence of Lithuanian Clusters: from Informal Cooperation to Its Legitimation

Directory of Open Access Journals (Sweden)

Grumadaitė Kristina

2017-06-01

Full Text Available This paper reveals preconditions for the emergence of clusters as self-organisation based industrial systems in a context, in which cooperation traditions are insufficiently developed. These preconditions reflect the principles of the emergence of self-organising complex adaptive systems that are analysed in the complexity theory. Those principles are based on the initiation of non-equilibrium and its purposeful direction into the creation of a new order. This paper highlights the main external and internal tensions that influence informal or formal clustering of enterprises, while various change agents perform different roles making self-organising processes to occur.

Hormesis in Cholestatic Liver Disease; Preconditioning with Low Bile Acid Concentrations Protects against Bile Acid-Induced Toxicity.

Directory of Open Access Journals (Sweden)

Esther M Verhaag

Full Text Available Cholestasis is characterized by accumulation of bile acids and inflammation, causing hepatocellular damage. Still, liver damage markers are highest in acute cholestasis and drop when this condition becomes chronic, indicating that hepatocytes adapt towards the hostile environment. This may be explained by a hormetic response in hepatocytes that limits cell death during cholestasis.To investigate the mechanisms that underlie the hormetic response that protect hepatocytes against experimental cholestatic conditions.HepG2.rNtcp cells were preconditioned (24 h with sub-apoptotic concentrations (0.1-50 μM of various bile acids, the superoxide donor menadione, TNF-α or the Farsenoid X Receptor agonist GW4064, followed by a challenge with the apoptosis-inducing bile acid glycochenodeoxycholic acid (GCDCA; 200 μM for 4 h, menadione (50 μM, 6 h or cytokine mixture (CM; 6 h. Levels of apoptotic and necrotic cell death, mRNA expression of the bile salt export pump (ABCB11 and bile acid sensors, as well as intracellular GCDCA levels were analyzed.Preconditioning with the pro-apoptotic bile acids GCDCA, taurocholic acid, or the protective bile acids (tauroursodeoxycholic acid reduced GCDCA-induced caspase-3/7 activity in HepG2.rNtcp cells. Bile acid preconditioning did not induce significant levels of necrosis in GCDCA-challenged HepG2.rNtcp cells. In contrast, preconditioning with cholic acid, menadione or TNF-α potentiated GCDCA-induced apoptosis. GCDCA preconditioning specifically reduced GCDCA-induced cell death and not CM- or menadione-induced apoptosis. The hormetic effect of GCDCA preconditioning was concentration- and time-dependent. GCDCA-, CDCA- and GW4064- preconditioning enhanced ABCB11 mRNA levels, but in contrast to the bile acids, GW4064 did not significantly reduce GCDCA-induced caspase-3/7 activity. The GCDCA challenge strongly increased intracellular levels of this bile acid, which was not lowered by GCDCA-preconditioning

Lipopolysaccharide preconditioning protects hepatocytes from ischemia/reperfusion injury (IRI through inhibiting ATF4-CHOP pathway in mice.

Directory of Open Access Journals (Sweden)

Jianhua Rao

Full Text Available BACKGROUND: Low-dose lipopolysaccharide (LPS preconditioning-induced liver protection has been demonstrated during ischemia-reperfusion injury (IRI in several organs but has not been sufficiently elucidated underlying causal mechanism. This study investigated the role of low-dose LPS preconditioning on ATF4-CHOP pathway as well as the effects of the pathway on tissue injury and inflammation in a mouse model of liver partial-warm IRI. METHODS: LPS (100 µg/kg/d was injected intraperitoneally two days before ischemia. Hepatic injury was evaluated based on serum alanine aminotransferase levels, histopathology, and caspase-3 activity. The ATF4-CHOP pathway and its related apoptotic molecules were investigated after reperfusion. The role of LPS preconditioning on apoptosis and ATF4-CHOP pathway was examined in vitro. Moreover, the effects of the ATF4-CHOP pathway on apoptosis, Caspase-12, and Caspase-3 were determined with ATF4 small interfering RNA (siRNA. Inflammatory cytokine expression was also checked after reperfusion. Inflammatory cytokines and related signaling pathways were analyzed in vitro in macrophages treated by LPS preconditioning or ATF4 siRNA. RESULTS: LPS preconditioning significantly attenuated liver injury after IRI. As demonstrated by in vitro experiments, LPS preconditioning significantly reduced the upregulation of the ATF4-CHOP pathway and inhibited Caspase-12 and Caspase-3 activation after IRI. Later experiments showed that ATF4 knockdown significantly suppressed CHOP, cleaved caspase-12 and caspase-3 expression, as well as inhibited hepatocellular apoptosis. In addition, in mice pretreated with LPS, TNF-α and IL-6 were inhibited after reperfusion, whereas IL-10 was upregulated. Similarly, low-dose LPS significantly inhibited TNF-α, IL-6, ATF4-CHOP pathway, NF-κB pathway, and ERK1/2 in high-dose LPS-stimulated macrophages, whereas IL-10 and cytokine signaling (SOCS-3 suppressor were induced. Importantly, ATF4 siRNA is

Preconditioned stochastic gradient descent optimisation for monomodal image registration

NARCIS (Netherlands)

Klein, S.; Staring, M.; Andersson, J.P.; Pluim, J.P.W.; Fichtinger, G.; Martel, A.; Peters, T.

2011-01-01

We present a stochastic optimisation method for intensity-based monomodal image registration. The method is based on a Robbins-Monro stochastic gradient descent method with adaptive step size estimation, and adds a preconditioning matrix. The derivation of the pre-conditioner is based on the

Preconditions for Citizen Journalism: A Sociological Assessment

OpenAIRE

Hayley Watson

2011-01-01

The rise of the citizen journalist and increased attention to this phenomenon requires a sociological assessment that seeks to develop an understanding of how citizen journalism has emerged in contemporary society. This article makes a distinction between two different subcategories of citizen journalism, that is independent and dependent citizen journalism. The purpose of this article is to present four preconditions for citizen journalism to emerge in contemporary society: advanced technolo...

Exploratory study of plasma total homocysteine and its relationship to short-term outcome in acute ischaemic stroke in Nigerians

Directory of Open Access Journals (Sweden)

Awosanya Gbolahan O

2008-07-01

Full Text Available Abstract Background Hyperhomocysteinemia is a potentially modifiable risk factor for stroke, and may have a negative impact on the course of ischaemic stroke. The role of hyperhomocysteinemia as it relates to stroke in Africans is still uncertain. The objective of this study was to determine the prevalence and short-term impact of hyperhomocysteinemia in Nigerians with acute ischaemic stroke. We hypothesized that Hcy levels are significantly higher than in normal controls, worsen stroke severity, and increase short-term case fatality rates following acute ischaemic stroke. Methods The study employed both a case-control and prospective follow-up design to study hospitalized adults with first – ever acute ischaemic stroke presenting within 48 hours of onset. Clinical histories, neurological evaluation (including National Institutes of Health Stroke Scale (NIHSS scores on admission were documented. Total plasma Hcy was determined on fasting samples drawn from controls and stroke cases (within 24 hours of hospitalization. Outcome at 4 weeks was assessed in stroke patients using the Glasgow Outcome Scale (GOS. Results We evaluated 155 persons (69 acute ischaemic stroke and 86 healthy controls. The mean age ± SD of the cases was 58.8 ± 9.8 years, comparable to that of controls which was 58.3 ± 9.9 years (T = 0.32; P = 0.75. The mean duration of stroke (SD prior to hospitalization was 43.5 ± 38.8 hours, and mean admission NIHSS score was 10.1 ± 7.7. Total fasting Hcy in stroke patients was 10.2 ± 4.6 umol/L and did not differ significantly from controls (10.1 ± 3.6 umol/L; P = 0.88. Hyperhomocysteinemia, defined by plasma Hcy levels > 90th percentile of controls (>14.2 umol/L in women and >14.6 umol/L in men, was present in 7 (10.1% stroke cases and 11 (12.8% controls (odds ratio 0.86, 95% confidence interval 0.31 – 2.39; P > 0.05. In multiple regression analysis admission NIHSS score (but not plasma Hcy was a significant determinant of 4

Preconditioning mesenchymal stem cells with the mood stabilizers lithium and valproic acid enhances therapeutic efficacy in a mouse model of Huntington's disease.

Science.gov (United States)

Linares, Gabriel R; Chiu, Chi-Tso; Scheuing, Lisa; Leng, Yan; Liao, Hsiao-Mei; Maric, Dragan; Chuang, De-Maw

2016-07-01

Huntington's disease (HD) is a fatal neurodegenerative disorder caused by CAG repeat expansions in the huntingtin gene. Although, stem cell-based therapy has emerged as a potential treatment for neurodegenerative diseases, limitations remain, including optimizing delivery to the brain and donor cell loss after transplantation. One strategy to boost cell survival and efficacy is to precondition cells before transplantation. Because the neuroprotective actions of the mood stabilizers lithium and valproic acid (VPA) induce multiple pro-survival signaling pathways, we hypothesized that preconditioning bone marrow-derived mesenchymal stem cells (MSCs) with lithium and VPA prior to intranasal delivery to the brain would enhance their therapeutic efficacy, and thereby facilitate functional recovery in N171-82Q HD transgenic mice. MSCs were treated in the presence or absence of combined lithium and VPA, and were then delivered by brain-targeted single intranasal administration to eight-week old HD mice. Histological analysis confirmed the presence of MSCs in the brain. Open-field test revealed that ambulatory distance and mean velocity were significantly improved in HD mice that received preconditioned MSCs, compared to HD vehicle-control and HD mice transplanted with non-preconditioned MSCs. Greater benefits on motor function were observed in HD mice given preconditioned MSCs, while HD mice treated with non-preconditioned MSCs showed no functional benefits. Moreover, preconditioned MSCs reduced striatal neuronal loss and huntingtin aggregates in HD mice. Gene expression profiling of preconditioned MSCs revealed a robust increase in expression of genes involved in trophic effects, antioxidant, anti-apoptosis, cytokine/chemokine receptor, migration, mitochondrial energy metabolism, and stress response signaling pathways. Consistent with this finding, preconditioned MSCs demonstrated increased survival after transplantation into the brain compared to non-preconditioned cells

Effect of screening and lifestyle counselling on incidence of ischaemic heart disease in general population

DEFF Research Database (Denmark)

Jørgensen, Torben; Jacobsen, Rikke Kart; Toft, Ulla

2014-01-01

of Copenhagen, Denmark. PARTICIPANTS: 59,616 people aged 30-60 years randomised with different age and sex randomisation ratios to an intervention group (n = 11,629) and a control group (n = 47,987). INTERVENTION: The intervention group was invited for screening, risk assessment, and lifestyle counselling up...... sessions of group based lifestyle counselling on smoking cessation, diet, and physical activity. After five years all were invited for a final counselling session. Participants were referred to their general practitioner for medical treatment, if relevant. The control group was not invited for screening......OBJECTIVE: To investigate the effect of systematic screening for risk factors for ischaemic heart disease followed by repeated lifestyle counselling on the 10 year development of ischaemic heart disease at a population level. DESIGN: Randomised controlled community based trial. SETTING: Suburbs...

Alterations of the outer retina in non-arteritic anterior ischaemic optic neuropathy detected using spectral-domain optical coherence tomography.

Science.gov (United States)

Ackermann, Philipp; Brachert, Maike; Albrecht, Philipp; Ringelstein, Marius; Finis, David; Geerling, Gerd; Aktas, Orhan; Guthoff, Rainer

2017-07-01

A characteristic disease pattern may be reflected by retinal layer thickness changes in non-arteritic anterior ischaemic optic neuropathy measured using spectraldomain optical coherence tomography. Retinal layer segmentation is enabled by advanced software. In this study, retinal layer thicknesses in acute and chronic non-arteritic anterior ischaemic optic neuropathy were compared. A single-centre cross-sectional analysis was used. A total of 27 patients (20 age-matched healthy eyes) were included: 14 with acute (optic neuropathy. Macular volume and 12° peripapillary ring optical coherence tomography scans were used. The peripapillary thicknesses of the following layers were determined by manual segmentation: retinal nerve fibres, ganglion cells + inner plexiform layer, inner nuclear layer + outer plexiform layer, outer nuclear layer + inner segments of the photoreceptors and outer segments of the photoreceptors to Bruch's membrane. Macular retinal layer thicknesses were automatically determined in volume cubes centred on the fovea. Peripapillary retinal swelling in acute nonarteritic anterior ischaemic optic neuropathy was attributable to retinal nerve fibre layer, ganglion cell layer/inner plexiform layer and outer nuclear layer/segments of the photoreceptors thickening. In chronic cases, peripapillary retinal nerve fibre layer, macular ganglion cell layer and inner plexiform layer thinning were observed. In acute non-arteritic anterior ischaemic optic neuropathy, the inner and outer peripapillary retinal layers are affected by thickness changes. In chronic cases, atrophy of the ganglion cells and their axons and dendrites is evident by inner retinal layer thinning. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

Effects of nitrous oxide on the rat heart in vivo: another inhalational anesthetic that preconditions the heart?

NARCIS (Netherlands)

Weber, Nina C.; Toma, Octavian; Awan, Saqib; Frässdorf, Jan; Preckel, Benedikt; Schlack, Wolfgang

2005-01-01

BACKGROUND: For nitrous oxide, a preconditioning effect on the heart has yet not been investigated. This is important because nitrous oxide is commonly used in combination with volatile anesthetics, which are known to precondition the heart. The authors aimed to clarify (1) whether nitrous oxide

The effect of the phytoestrogen genistein on myocardial protection, preconditioning and oxidative stress.

Science.gov (United States)

Sbarouni, Eftihia; Iliodromitis, Efstathios K; Zoga, Anastasia; Vlachou, Georgia; Andreadou, Ioanna; Kremastinos, Dimitrios Th

2006-08-01

We have previously shown that estrogen administered in ovariectomized female rabbits significantly reduce myocardial infarct size. We now investigated whether the phytoestrogen genistein similarly protects ischemic myocardium and whether this is associated with its antioxidant properties. In addition, we examined whether genistein abolishes preconditioning, since at high doses, it inhibits tyrosine kinase. We studied five groups of New Zealand white female rabbits. Group A (n = 12) were normal controls, group B (n = 14) were ovariectomized 4 weeks prior to the experiment, group C (n = 10) were ovariectomized and treated with genistein (0.2 mg kg(-1) day(-1) subcutaneously) for 4 weeks before the experiment, group D (n = 12) had intact gonads and were treated with genistein (0.2 mg kg(-1) day(-1) subcutaneously) for 4 weeks before the experiment and group E (n = 8) were ovariectomized 4 weeks prior to the experiment and treated with a single dose of genistein (0.2 mg kg(-1) day(-1) subcutaneously) just prior to the experiment. All animals underwent 30 min of heart ischemia and 120 min of reperfusion, with (subgroup I) or without (subgroup II) preconditioning. Malondialdehyde (MDA) concentration just before the experiment was determined. We found significant differences between the groups-p protect ischemic myocardium in either ovariectomized or non-ovariectomized animals-BII vs CII and AII vs DII, p = NS. There was no significant difference between the preconditioned animals, with intact gonads or ovariectomized (AI vs BI, p = NS), ovariectomized with or without genistein (BI vs CI, p = NS) and non-ovariectomized whether treated with genistein or not (AI vs DI, p = NS). A single dose of genistein did not offer any protection (EII vs BII, p = NS), nor did it modify the preconditioning effect (EI vs BI, p = NS). We found no significant difference in MDA plasma levels between the groups. Genistein, at this dose, does not reduce infarct size per se nor abolishes the

Dramatic response to levetiracetam in post-ischaemic Holmes’ tremor

Science.gov (United States)

Striano, P; Elefante, Andrea; Coppola, Antonietta; Tortora, Fabio; Zara, Federico; Minetti, Carlo

2009-01-01

Holmes’ tremor refers to an unusual combination of rest, postural and kinetic tremor of extremities. Common causes of Holmes’ tremor include stroke, trauma, vascular malformations and multiple sclerosis, with lesions involving the thalamus, brain stem or cerebellum. Although some drugs (eg, levodopa and dopaminergic drugs, clonazepam and propranolol) have been occasionally reported to give some benefit, medical treatment of Holmes’ tremor is unsatisfactory, and many patients require thalamic surgery to achieve satisfactory control. We report a patient in whom post-ischaemic Holmes’ tremor dramatically responded to levetiracetam treatment. PMID:21686707

Hemorrhagic transformation in patients with acute ischaemic stroke and an indication for anticoagulation.

Science.gov (United States)

Marsh, E B; Llinas, R H; Hillis, A E; Gottesman, R F

2013-06-01

Intracerebral hemorrhage (ICH) can occur in patients following acute ischaemic stroke in the form of hemorrhagic transformation, and results in significant long-term morbidity and mortality. Anticoagulation theoretically increases risk. We evaluated stroke patients with an indication for anticoagulation to determine the factors associated with hemorrhagic transformation. Three-hundred and forty-five patients with ICD-9 codes indicating: (i) acute ischaemic stroke; and (ii) an indication for anticoagulation were screened. One-hundred and twenty-three met inclusion criteria. Data were collected retrospectively. Neuroimaging was reviewed for infarct volume and evidence of ICH. Hemorrhages were classified as: hemorrhagic conversion (petechiae) versus intracerebral hematoma (a space occupying lesion); symptomatic versus asymptomatic. Using multivariable logistic regression, we determined the hypothesized factors associated with intracerebral bleeding. Age [odds ratio (OR) = 1.50 per 10-year increment, 95% confidence interval (CI) 1.07-2.08], infarct volume (OR = 1.10 per 10 ccs, 95% CI 1.06-1.18) and worsening category of renal impairment by estimated glomerular filtration rate (eGFR; OR = 1.95, 95% CI 1.04-3.66) were predictors of hemorrhagic transformation. Ninety- nine out of 123 patients were anticoagulated. Hemorrhage rates of patients on and off anticoagulation did not differ (25.3% vs. 20.8%; P = 0.79); however, all intracerebral hematomas (n = 7) and symptomatic bleeds (n = 8) occurred in the anticoagulated group. The risk of hemorrhagic transformation in patients with acute ischaemic stroke and an indication for anticoagulation is multifactorial, and most closely associated with an individual's age, infarct volume and eGFR. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Solving large test-day models by iteration on data and preconditioned conjugate gradient.

Science.gov (United States)

Lidauer, M; Strandén, I; Mäntysaari, E A; Pösö, J; Kettunen, A

1999-12-01

A preconditioned conjugate gradient method was implemented into an iteration on a program for data estimation of breeding values, and its convergence characteristics were studied. An algorithm was used as a reference in which one fixed effect was solved by Gauss-Seidel method, and other effects were solved by a second-order Jacobi method. Implementation of the preconditioned conjugate gradient required storing four vectors (size equal to number of unknowns in the mixed model equations) in random access memory and reading the data at each round of iteration. The preconditioner comprised diagonal blocks of the coefficient matrix. Comparison of algorithms was based on solutions of mixed model equations obtained by a single-trait animal model and a single-trait, random regression test-day model. Data sets for both models used milk yield records of primiparous Finnish dairy cows. Animal model data comprised 665,629 lactation milk yields and random regression test-day model data of 6,732,765 test-day milk yields. Both models included pedigree information of 1,099,622 animals. The animal model ¿random regression test-day model¿ required 122 ¿305¿ rounds of iteration to converge with the reference algorithm, but only 88 ¿149¿ were required with the preconditioned conjugate gradient. To solve the random regression test-day model with the preconditioned conjugate gradient required 237 megabytes of random access memory and took 14% of the computation time needed by the reference algorithm.