Evaluation of Pulmonary Perfusion Scan in Heart Disease

Energy Technology Data Exchange (ETDEWEB)

Lee, J T; Kim, C K; Park, C Y; Choi, B S [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1973-09-15

Pulmonary perfusion scan with radioactive {sup 113m}In-iron hydroxide particle was performed in the 25 cases of heart disease which had been diagnosed by cardiac catheterization prior to surgery from July, 1972 to July, 1973 at the Department of Radiology and Nuclear Medicine, Yonsei Medical College. It consists of 7 mitral stenosis, 2 mitral insufficiency, 1 aortic insufficiency, 3 atrial septal defect, 5 ventricular septal defect, 2 patent ductus arteriosus, 1 transposition of great vessel and 4 Tetralogy of Fallot. Findings of pulmonary perfusion scan in relation to hemodynamic data of cardiac catheterization were examined. 1) Out of 10 cases of acquired valvular heart disease, In 6 cases of stenosis and 1 case of aortic insufficiency, radioactivity was increased at both upper lung. This finding is noted when pulmonary wedge or venous pressure was elevated above 22 mmHg and arterial systolic pressure above 33 mmHg. 2) Out of 15 cases of congenital heart disease. In almost all cases of artial septal defect and ventricular septal defect except 2 cases, radioactivity was even at both entire lung. In 2 cases of patent ductras arteriosus, radioactivity was decreased especially at the left lung. It is observed that in acyanotic congenital heart disease, radioactivity of lung is not related with pulmonary arterial pressure. In 3 cases of Tetralogy of Fallot, radioactivity was even at both entire lung and in 2 of them, extrapulmonary radioactivity of liver or kidney which depends on size of defect and volume of right to left shunt reversible, was noted.

Evaluation of Pulmonary Perfusion Scan in Heart Disease

International Nuclear Information System (INIS)

Lee, J. T.; Kim, C. K.; Park, C. Y.; Choi, B. S.

1973-01-01

Pulmonary perfusion scan with radioactive 113m In-iron hydroxide particle was performed in the 25 cases of heart disease which had been diagnosed by cardiac catheterization prior to surgery from July, 1972 to July, 1973 at the Department of Radiology and Nuclear Medicine, Yonsei Medical College. It consists of 7 mitral stenosis, 2 mitral insufficiency, 1 aortic insufficiency, 3 atrial septal defect, 5 ventricular septal defect, 2 patent ductus arteriosus, 1 transposition of great vessel and 4 Tetralogy of Fallot. Findings of pulmonary perfusion scan in relation to hemodynamic data of cardiac catheterization were examined. 1) Out of 10 cases of acquired valvular heart disease, In 6 cases of stenosis and 1 case of aortic insufficiency, radioactivity was increased at both upper lung. This finding is noted when pulmonary wedge or venous pressure was elevated above 22 mmHg and arterial systolic pressure above 33 mmHg. 2) Out of 15 cases of congenital heart disease. In almost all cases of artial septal defect and ventricular septal defect except 2 cases, radioactivity was even at both entire lung. In 2 cases of patent ductras arteriosus, radioactivity was decreased especially at the left lung. It is observed that in acyanotic congenital heart disease, radioactivity of lung is not related with pulmonary arterial pressure. In 3 cases of Tetralogy of Fallot, radioactivity was even at both entire lung and in 2 of them, extrapulmonary radioactivity of liver or kidney which depends on size of defect and volume of right to left shunt reversible, was noted.

Ordered synthesis and mobilization of glycogen in the perfused heart

International Nuclear Information System (INIS)

Brainard, J.R.; Hutson, J.Y.; Hoekenga, D.E.; Lenhoff, R.

1989-01-01

The molecular order of synthesis and mobilization of glycogen in the perfused heart was studied by 13 C NMR. By varying the glucose isotopomer ([1- 13 C]glucose or [2- 13 C]glucose) supplied to the heart, glycogen synthesized at different times during the perfusion was labeled at different carbon sites. Subsequently, the in situ mobilization of glycogen during ischemia was observed by detection of labeled lactate derived from glycolysis of the glucosyl monomers. When [1- 13 C]glucose was given initially in the perfusion and [2- 13 C]glucose was given second, [2- 13 C]lactate was detected first during ischemia and [3- 13 C]lactate second. This result, and the equivalent result when the glucose labels were given in the reverse order, demonstrates that glycogen synthesis and mobilization are ordered in the heart, where glycogen is found morphologically only as β particles. Previous studies of glycogen synthesis and mobilization in liver and adipocytes have suggested that the organization of β particles into α particles was partially responsible for ordered synthesis and mobilization. The observations reported here for cardiac glycogen suggest that another mechanism is responsible. In addition to examine the ordered synthesis and mobilization of cardiac glycogen, the authors have selectively monitored the NMR properties of 13 C-labeled glycogen synthesized early in the perfusion during further glycogen synthesis from a second, differently labeled substrate. During synthesis from the second labeled glucose monomer, the glycogen resonance from the first label decreased in integrated intensity and increased in line width. These results suggest either that there is significant isotopic exchange of glucosyl monomers in glycogen during net synthesis or that glucosyl residues incorporated into glycogen undergo motional restrictions as further glycogen synthesis occurs

Effects of perfusion pressure and insulin on (3H) cytochalasin B (CB) binding to control and diabetic rat hearts

International Nuclear Information System (INIS)

Pleta, M.; Chan, T.

1987-01-01

Using ( 3 H) CB, they attempted to quantitate the changes in the amount of glucose transporters in the plasma membrane (PM) and intracellular membranes (HSP) prepared from rat hearts perfused with insulin, under low and high pressure. Membranes isolated from non-perfused hearts showed a PM/HSP ratio of (0.593). Hearts perfused with low pressure showed a lower ratio of (0.474). Perfusion with insulin increased the ratio to (1.8), almost a 3-4 fold increase from low perfusion pressure. These data correlate with insulin effects in glucose transport and CB binding in the fat cells. High pressure perfusion increased the PM/HSP ratio by 1-2 fold. ( 3 H) 2-DG transport indicates a comparable increase in glucose uptake with high pressure, but with insulin only a 1.5 fold increase was observed. Initial data obtained from streptozotocin (STZ) injected diabetic rats indicate low CB binding in the PM fraction. Only insulin, but not high perfusion pressure increased PM/HSP ratio in the STZ-diabetic hearts. Their data imply that while both caused apparent translocation of glucose transporters, influences on cardiac glucose metabolism by work load are different. Furthermore, STZ induced diabetes affected only the high perfusion pressure-induced and not the insulin-stimulated change in CB binding

The evaluation of dobutamine 99mTc-MIBI myocardial perfusion imaging in the diagnosis of coronary heart disease

International Nuclear Information System (INIS)

He Qing; Qu Wanying; Gong Junhui; Zhou Ying

1996-01-01

The method and the clinical value of dobutamine stress test as a substitute for exercise test in 99m Tc-MIBI myocardial perfusion imaging was investigated. 40 Patients were intravenously infused with dobutamine through IVAC syringe pumps by incremental doses, and 99m Tc-MIBI was injected at the peak dobutamine heart rate. The myocardial imaging was then performed. The rest myocardial imaging was done after 48 hours. 30 of the 31 patients with coronary heart disease showed reversible perfusion defects in dobutamine 99m Tc-MIBI myocardial perfusion images and 7 of the 9 patients without coronary heart disease showed normal images. The sensitivity of this test was 96.8% and the specificity 77.8%. None of the studies was discontinued due to dobutamine side effect. Dobutamine 99m Tc-MIBI myocardial perfusion imaging is a safe and sensitive method in the diagnosis of coronary heart disease

Persufflation (gaseous oxygen perfusion) as a method of heart preservation.

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Suszynski, Thomas M; Rizzari, Michael D; Scott, William E; Eckman, Peter M; Fonger, James D; John, Ranjit; Chronos, Nicolas; Tempelman, Linda A; Sutherland, David E R; Papas, Klearchos K

2013-04-22

Persufflation (PSF; gaseous oxygen perfusion) is an organ preservation technique with a potential for use in donor heart preservation. Improved heart preservation with PSF may improve outcomes by maintaining cardiac tissue quality in the setting of longer cold ischemia times and possibly increasing the number of donor hearts available for allotransplant. Published data suggests that PSF is able to extend the cold storage times for porcine hearts up to 14 hours without compromising viability and function, and has been shown to resuscitate porcine hearts following donation after cardiac death. This review summarizes key published work on heart PSF, including prospective implications and future directions for PSF in heart transplantation. We emphasize the potential impact of extending preservation times and expanding donor selection criteria in heart allotransplant. Additionally, the key issues that need to be addressed before PSF were to become a widely utilized preservation strategy prior to clinical heart transplantation are summarized and discussed.

A novel combination technique of cold crystalloid perfusion but not cold storage facilitates transplantation of canine hearts donated after circulatory death.

Science.gov (United States)

Rosenfeldt, Franklin; Ou, Ruchong; Salamonsen, Robert; Marasco, Silvana; Zimmet, Adam; Byrne, Joshua; Cosic, Filip; Saxena, Pankaj; Esmore, Donald

2016-11-01

Donation after circulatory death (DCD) represents a potential new source of hearts to increase the donor pool. We showed previously that DCD hearts in Greyhound dogs could be resuscitated and preserved by continuous cold crystalloid perfusion but not by cold static storage and could demonstrate excellent contractile and metabolic function on an in vitro system. In the current study, we demonstrate that resuscitated DCD hearts are transplantable. Donor Greyhound dogs (n = 12) were divided into perfusion (n = 8) and cold static storage (n = 4) groups. General anesthesia was induced and ventilation ceased for 30 minutes to achieve circulatory death. Donor cardiectomy was performed, and for 4 hours the heart was preserved by controlled reperfusion, followed by continuous cold perfusion with an oxygenated crystalloid perfusate or by static cold storage, after which orthotopic heart transplantation was performed. Recovery was assessed over 4 hours by hemodynamic monitoring. During cold perfusion, hearts showed continuous oxygen consumption and low lactate levels, indicating aerobic metabolism. The 8 dogs in the perfusion group were weaned off bypass, and 4 hours after bypass produced cardiac output of 4.73 ± 0.51 liters/min, left ventricular power of 7.63 ± 1.32 J/s, right ventricular power of 1.40 ± 0.43 J/s, and left ventricular fractional area shortening of 39.1% ± 5.2%, all comparable to pre-transplant values. In the cold storage group, 3 of 4 animals could not be weaned from cardiopulmonary bypass, and the fourth exhibited low-level function. Cold crystalloid perfusion, but not cold static storage, can resuscitate and preserve the DCD donor heart in a canine model of heart transplantation, thus rendering it transplantable. Controlled reperfusion and cold crystalloid perfusion have potential for clinical application in DCD transplantation. Copyright © 2016. Published by Elsevier Inc.

Lung perfusion scintigraphy in congenital heart disease

International Nuclear Information System (INIS)

Sugimura, Hiroshi; Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Oonishi, Takashi; Futami, Shigemi; Watanabe, Katsushi

1990-01-01

Lung perfusion scintigrams were reviewed retrospectively in 28 patients with congenital heart disease, whose ages ranged from the first year to 16 years with an average age of 5 years and 6 months. Seventy four MBq (2 mCi), 111 MBq (2 mCi), and 185 MBq (5 mCi) of Tc-99m macroaggregated albumin were iv injected in the age groups of 0-3, 4-11, and more than 11 years, respectively. Five minutes later, images were obtained in six projections. Abnormal findings on lung perfusion scintigrams were observed in 13 patients (46%). Of these patients, 8 (29%) had a partially decreased blood flow and 5 (17%) had a decreased blood flow in the unilateral lung. No significant difference in the occurrence of abnormal findings was observed among the age groups, although they tended to occur in younger patients. Sex, underlying conditions, and hemodynamics were also independent of scintigraphically abnormal findings. Even when classifying the patients as having either cyanotic or non-cyanotic heart disease, no significant difference in hemodynamics was observed between the group of abnormal findings and the group of normal findings. Pulmonary arteriography available in all patients failed to reveal abnormal findings, with the exception of pulmonary artery stenosis in 2 patients that corresponded to a decreased blood flow in the unilateral lung. Pulmonary artery stenosis seemed to be responsible for abnormal pulmonary blood flow, although other causes remained uncertain. (N.K.)

Epicardial excitation pattern as observed in the isolated revived and perfused fetal human heart

NARCIS (Netherlands)

Durrer, D.; Büller, J.; Graaff, P.; Lo, G.I.; Meijler, F.L.

1961-01-01

The resuscitated fetal human heart can be used as an experimental tooI for the investigation of the excitatory process in the human heart. During perfusion the configuration of the epicardial electrocardiograms does not change appreciably. For accurate recording permitting a detailed analysis, the

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

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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.)

Myocardial Creatine Levels Do Not Influence Response to Acute Oxidative Stress in Isolated Perfused Heart

Science.gov (United States)

Aksentijević, Dunja; Zervou, Sevasti; Faller, Kiterie M. E.; McAndrew, Debra J.; Schneider, Jurgen E.; Neubauer, Stefan; Lygate, Craig A.

2014-01-01

Background Multiple studies suggest creatine mediates anti-oxidant activity in addition to its established role in cellular energy metabolism. The functional significance for the heart has yet to be established, but antioxidant activity could contribute to the cardioprotective effect of creatine in ischaemia/reperfusion injury. Objectives To determine whether intracellular creatine levels influence responses to acute reactive oxygen species (ROS) exposure in the intact beating heart. We hypothesised that mice with elevated creatine due to over-expression of the creatine transporter (CrT-OE) would be relatively protected, while mice with creatine-deficiency (GAMT KO) would fare worse. Methods and Results CrT-OE mice were pre-selected for creatine levels 20–100% above wild-type using in vivo 1H–MRS. Hearts were perfused in isovolumic Langendorff mode and cardiac function monitored throughout. After 20 min equilibration, hearts were perfused with either H2O2 0.5 µM (30 min), or the anti-neoplastic drug doxorubicin 15 µM (100 min). Protein carbonylation, creatine kinase isoenzyme activities and phospho-PKCδ expression were quantified in perfused hearts as markers of oxidative damage and apoptotic signalling. Wild-type hearts responded to ROS challenge with a profound decline in contractile function that was ameliorated by co-administration of catalase or dexrazoxane as positive controls. In contrast, the functional deterioration in CrT-OE and GAMT KO hearts was indistinguishable from wild-type controls, as was the extent of oxidative damage and apoptosis. Exogenous creatine supplementation also failed to protect hearts from doxorubicin-induced dysfunction. Conclusions Intracellular creatine levels do not influence the response to acute ROS challenge in the intact beating heart, arguing against creatine exerting (patho-)physiologically relevant anti-oxidant activity. PMID:25272153

Effect of milrinone therapy on splanchnic perfusion after heart transplantation.

Science.gov (United States)

Urbanowicz, Tomasz; Ligowski, Marcin; Camacho, Estillita; Walczak, Maciej; Straburzyńska-Migaj, Ewa; Tomczyk, Jadwiga; Jemielity, Marek

2014-09-23

Milrinone is a selective inhibitor of the cAMP-specific phosphodiesterase III isoenzyme in myocardium and vascular smooth muscle. Milrinone administration following heart transplantation is routine practice. The purpose of this study was to evaluate the influence of milrinone therapy on splanchnic perfusion following heart transplantation. There were 12 patients (10 males and 2 females) with a mean age of 42 ± 12 who underwent heart transplantation. Milrinone parenteral following surgery was started after surgery and continued for the next 67 ± 4 h. Repeated Swann-Ganz measurements and control transthoracic echocardiography were performed. Blood samples were taken to estimate level of lactic acid (LA), liver transaminases, serum amylase, and GFR ratio. The mean time of milrinone administration was 67 ± 4 h. The serum LA increase following milrinone discontinuation was 1.7 ± 0.7 mmol/dm(3) vs. 3.8 ± 0.9 mmol/dm(3), (pmilrinone discontinuation was 79 ± 30 IU/L vs. 135 ± 55 IU/L, pmilrinone withdrawn. There was a progressive increase in serum amylase levels after milrinone was withdrawn (80.6 ± 29 IU/L vs. 134 ± 45 IU/L, pMilrinone withdrawal during the postoperative period was associated with deterioration of splanchnic perfusion, as shown by a transient increase in lactic acid and serum increase of aminotransferases (ALT/ASP) concentration and amylase activity. The study results show the extracardiac effects of milrinone therapy.

Uptake of perfusion imaging agents by transplanted hearts: an experimental study in rats

International Nuclear Information System (INIS)

Bergsland, J.; Carr, E.A. Jr.; Carroll, M.; Feldman, M.J.; Kung, H.; Wright, J.R.

1989-01-01

There is a need for a reliable noninvasive marker of rejection in transplanted hearts. Endomyocardial biopsy is now the universally accepted diagnostic method of choice, but the invasiveness of the procedure and the limited size of the sample obtained makes this method far from ideal. As coronary blood flow may be expected to decrease during acute rejection, there has been interest in thallium-201 chloride (T1), a perfusion marker, as an imaging agent for diagnosing cardiac rejection. Hexakis(t-butylisonitrile)-technetium (Tc-TBI) is a representative of a new class of radiopharmaceuticals proposed as perfusion markers. We have compared the uptake of these imaging agents in a rat model of cardiac transplantation. Uptake of Tc-TBI as well as of T1 was significantly lower in rejecting than in nonrejecting hearts. This change was found in both left (LV) and right (RV) ventricles. Allografts in animals treated with cyclosporine (CyA) showed less severe rejection and higher uptakes of both imaging agents as compared to unmodified rejection. Our results suggest that perfusion imaging with these radionuclides is a potentially useful approach to the problem of detecting allograft rejection

Evaluation of heart perfusion in patients with acute myocardial infarction using dynamic contrast-enhanced magnetic resonance imaging

DEFF Research Database (Denmark)

Nielsen, Gitte; Fritz-Hansen, Thomas; Dirks, Christina G

2004-01-01

with acute transmural myocardial infarction were studied using a Turbo-fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five......PURPOSE: To investigate the diagnostic ability of quantitative magnetic resonance imaging (MRI) heart perfusion in acute heart patients, a fast, multislice dynamic contrast-enhanced MRI sequence was applied to patients with acute myocardial infarction. MATERIALS AND METHODS: Seven patients...

Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy

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Goo, Hyun Woo; Park, Sang Hyub [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

2017-11-15

Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy. (orig.)

Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy

International Nuclear Information System (INIS)

Goo, Hyun Woo; Park, Sang Hyub

2017-01-01

Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy. (orig.)

Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy.

Science.gov (United States)

Goo, Hyun Woo; Park, Sang Hyub

2017-11-01

Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy.

Myocardial perfusion imaging for the detection of coronary heart disease

International Nuclear Information System (INIS)

Strauss, H.W.; Cook, D.J.; Bailey, I.; Rouleau, J.; Pitt, B.

1976-01-01

A method of myocardial perfusion imaging using 201 Tl is described. Thallium is able to substitute for potassium in biological systems including transport by the sodium--potassium ATP-ase system. The high extraction efficiency of the heart for 201 Tl offers a method whereby a tracer may be administered intravenously and is concentrated to a significant degree by the heart. However, only about 3 to 4 percent of the dose administered lodges in the myocardium. Experiments with dogs indicated that the regional distribution of Tl in the heart reflects the regional distribution of blood flow. The goal is to develop a procedure that can detect those patients with significant disease prior to the onset of a catastrophic event and studies are being undertaken to improve the sensitivity of the method for the detection of smaller lesions in the myocardium

Chamber-specific effects of hypokalaemia on ventricular arrhythmogenicity in isolated, perfused guinea-pig heart

DEFF Research Database (Denmark)

Osadchii, Oleg E; Bentzen, Bo Hjorth; Olesen, Søren-Peter

2009-01-01

of hypokalaemic perfusion (2.5 mm K(+) for 30 min) were assessed in isolated guinea-pig heart preparations using simultaneous recordings of volume-conducted electrocardiogram and monophasic action potentials from six ventricular epicardial sites. Effective refractory periods, ventricular fibrillation thresholds...... for re-entrant tachyarrhythmias. Taken together, these findings suggest that proarrhythmic effects of hypokalaemia are mostly attributed to increased LV arrhythmogenicity in the guinea-pig heart....

Volume of myocardium perfused by coronary artery branches as estimated from 3D micro-CT images of rat hearts

Science.gov (United States)

Lund, Patricia E.; Naessens, Lauren C.; Seaman, Catherine A.; Reyes, Denise A.; Ritman, Erik L.

2000-04-01

Average myocardial perfusion is remarkably consistent throughout the heart wall under resting conditions and the velocity of blood flow is fairly reproducible from artery to artery. Based on these observations, and the fact that flow through an artery is the product of arterial cross-sectional area and blood flow velocity, we would expect the volume of myocardium perfused to be proportional to the cross-sectional area of the coronary artery perfusing that volume of myocardium. This relationship has been confirmed by others in pigs, dogs and humans. To test the body size-dependence of this relationship we used the hearts from rats, 3 through 25 weeks of age. The coronary arteries were infused with radiopaque microfil polymer and the hearts scanned in a micro- CT scanner. Using these 3D images we measured the volume of myocardium and the arterial cross-sectional area of the artery that perfused that volume of myocardium. The average constant of proportionality was found to be 0.15 +/- 0.08 cm3/mm2. Our data showed no statistically different estimates of the constant of proportionality in the rat hearts of different ages nor between the left and right coronary arteries. This constant is smaller than that observed in large animals and humans, but this difference is consistent with the body mass-dependence on metabolic rate.

The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

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Dian Ratri Wulandari

2013-04-01

Full Text Available Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus, it requires the construction of new various facilities to support its huge activities. Extensive construction can be destructive even damaging to the habitat of frog, which potentially threats the frog’s life, if it does not take the environmental impact into careful consideration. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in 1995. Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in 1995; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota. This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

Association between left ventricular perfusion defects and myocardial deformation indexes in heart transplantation recipients.

Science.gov (United States)

D'Andrea, Antonello; De Rimini, Maria Luisa; America, Raffaella; Cirillo, Chiara; Riegler, Lucia; Limongelli, Giuseppe; D'Alto, Michele; Salerno, Gemma; Maiello, Ciro; Muto, Pietro; Russo, Maria Giovanna; Calabrò, Raffaele; Bossone, Eduardo; Pacileo, Giuseppe

2017-10-01

The aim of the study was to analyze possible correlations between strain echocardiography (STE) and PET myocardial perfusion in a population of heart transplantation (HTx) recipients showing preserved left ventricular (LV) ejection fraction. By STE, LV global longitudinal strain (LV GLS) was lower in HTx. PET showed no transient or chronic ischemia in 83 of 115 HTx (73%). Fixed perfusion defects were observed in 17% of HTx and reversible ischemia in 10%. Significant coronary stenosis was observed only in 10 cases. GLS was independently associated with age at HTx and fixed perfusion defects (HR 0.41; P<.001). Such relationships underline STE ability to early identify HTx pts with subclinical myocardial dysfunction during long-term follow-up. © 2017, Wiley Periodicals, Inc.

Myocardial perfusion imaging with thalium 201 during and after exercise in patients with coronary heart

Energy Technology Data Exchange (ETDEWEB)

Bravo, P B; Villacorta, E V; Monzon, O P; Torres, Jr, J F; Guzman, S V

1977-07-01

A unique, non-invasive technique for the evaluation of the regional myocardial perfusion of patients with coronary heart disease has been developed. This entails the use of radionuclide, like thallium (Tl-201), which concentrates in the normal myocardium, leaving areas of ischemia or scarring or ''cold'' perfusion defects. Myocardial perfusion imaging in conjunction with graded exercise testing significantly increases the positivity of the stress test alone among patients with classic angina from 80% to 95%. It gives invaluable information as to the site and extent of the lesion and its reversibility. Among the patients with ECG Q waves indicative of previous infarction, image defects were detected in 93.7%; reversible ischemia co-existing with the infarction was also demonstrated.

Evaluation of multi-gated myocardial perfusion imaging in various heart diseases

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Uehara, Toshitake; Kozuka, Takahiro

1980-01-01

Multi-gated myocardial perfusion imaging were studied in a hundred cases of various heart diseases. In normal cases, ED ES images showed thinning and thickening of wall motion respectively to compare with static images. In the myocardial infarction cases, the dynamic changes of wall motion was decreased at infarcted areas in all cases. In congestive cardiomyopathy, the change of wall motion is smaller than normal cases in all cases, while in hypertrophic cardiomyopathy, the change is not so hyperdynamic to compare with normal cases and by multi-gated images, asymmetric hypertrophy was clearly detected in HCM than static images. In conclusion, these methods were useful to detect the myocardial contraction stage in various heart diseases. (author)

Large-Animal Biventricular Working Heart Perfusion System with Low Priming Volume-Comparison between in vivo and ex vivo Cardiac Function.

Science.gov (United States)

Abicht, Jan-Michael; Mayr, Tanja Axinja Jelena; Jauch, Judith; Guethoff, Sonja; Buchholz, Stefan; Reichart, Bruno; Bauer, Andreas

2018-01-01

Existing large-animal, ex vivo, cardiac perfusion models are restricted in their ability to establish an ischemia/reperfusion condition as seen in cardiac surgery or transplantation. Other working heart systems only challenge one ventricle or require a substantially larger priming volume. We describe a novel biventricular cardiac perfusion system with reduced priming volume. Juvenile pig hearts were cardiopleged, explanted, and reperfused ex vivo after 150 minutes of cold ischemia. Autologous whole blood was used as perfusate (minimal priming volume 350 mL). After 15 minutes of Langendorff perfusion (LM), the system was switched into a biventricular working mode (WM) and studied for 3 hours. During reperfusion, complete unloading of both ventricles and constant-pressure coronary perfusion was achieved. During working mode perfusion, the preload and afterload pressure of both ventricles was controlled within the targeted physiologic range. Functional parameters such as left ventricular work index were reduced in ex vivo working mode (in vivo: 787 ± 186 vs. 1 h WM 498 ± 66 mm Hg·mL/g·min; p  hours while functional and blood parameters are easily accessible. Moreover, because of the minimal priming volume, the novel ex vivo cardiac perfusion circuit allows for autologous perfusion, using the limited amount of blood available from the organ donating animal. Georg Thieme Verlag KG Stuttgart · New York.

Polarographic measurement of ascorbate washout in isolated perfused rabbit hearts

International Nuclear Information System (INIS)

Arts, T.; Kuikka, J.T.; Reneman, R.S.; Bassingthwaighte, J.B.

1985-01-01

To study the myocardial washout of ascorbate, the applicability of polarographic detection of ascorbate ions by a platinum electrode (sensitive area 0.03 mm2) was investigated, in both a calibration setup (sampling flow along the electrode: 100 microliter X s-1) and isolated, retrogradely perfused rabbit hearts. In the calibration setup at pH 7.4, the sensitivity of the electrode was 70 microA/mol. This sensitivity increased moderately with increasing pH (13%/unit pH) and increasing sampling flow rate (14% at an increase from 100 to 150 microliter X s-1). In the isolated hearts, ascorbate infused into the aorta was detected in a right ventricular drain by the electrode as well as by the use of 14 C-labeled ascorbate. Both recorded time courses were similar except for a scaling factor dependent on flow velocity. During continuous infusion the arteriovenous difference of ascorbate was 2 +/- 2% (SD), indicating a relatively low consumption of ascorbate by the isolated heart. The authors conclude that polarographic measurement of ascorbate in the coronary effluent of an isolated rabbit heart can be performed on-line and relatively easily

The influence of Poly-Vinyl-Chloride tubing on the isolated perfused rat´s heart.

NARCIS (Netherlands)

Meijler, F.L.; Durrer, D.

1950-01-01

There are types of poly-vinyl-chloride tubing sold and used for medical and biological purposes which deteriorate heart action in a few minutes. A simple method for testing P.V.C. tubing can be found in the isolated rat's he art perfused according to Langendorff.

Estimation of pulmonary hypertension in lung and valvular heart diseases by perfusion lung scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Fujii, Tadashige [Shinshu Univ., Matsumoto, Nagano (Japan). School of Allied Medical Sciences; Tanaka, Masao; Yazaki, Yoshikazu; Kitabayashi, Hirosi; Koizumi, Tomonori; Kubo, Keisi; Sekiguchi, Morie; Yano, Kesato

1999-06-01

To estimate pulmonary hypertension, we measured postural differences in pulmonary blood flow for the lateral decubitus positions on perfusion lung scintigrams with Tc-99 m macro-aggregated albumin, applying the method devised by Tanaka et al (Eur J Nucl Med 17: 320-326, 1990). Utilizing a scintillation camera coupled to a minicomputer system, changes in the distribution of pulmonary blood flow caused by gravitational effects, namely, changes in the total count ratios for the right lung versus the left lung in the right and left lateral decubitus positions (R/L), were obtained for 44 patients with lung disease, 95 patients with valvular heart disease, and 23 normal subjects. Mean standard deviation in the R/L ratios was 3.09{+-}1.28 for the normal subjects, 1.97{+-}0.89 for the patients with lung disease, and 1.59{+-}0.59 for the patients with valvular heart disease. The R/L ratios correlated with mean pulmonary arterial pressure and cardio-thoracic ratios in the lung disease and valvular heart disease groups, with pulmonary arteriolar resistance in the former, and with pulmonary capillary wedge pressure in the latter. Defining pulmonary hypertension (>20 mmHg) as an R/L ratio of less than 1.81, which is the mean-1 standard deviation for normal subjects, the sensitivity and the specificity of the R/L ratio for the diagnosis of pulmonary hypertension were 62.9% and 76.2%, respectively, for the lung disease patients, and 80.3% and 61.8%, respectively, for the valvular heart disease patients. This method seems to be useful for the pathophysiologic evaluation of pulmonary perfusion in cases of lung disease and valvular heart disease. (author)

Estimation of pulmonary hypertension in lung and valvular heart diseases by perfusion lung scintigraphy

International Nuclear Information System (INIS)

Fujii, Tadashige; Tanaka, Masao; Yazaki, Yoshikazu; Kitabayashi, Hirosi; Koizumi, Tomonori; Kubo, Keisi; Sekiguchi, Morie; Yano, Kesato

1999-01-01

To estimate pulmonary hypertension, we measured postural differences in pulmonary blood flow for the lateral decubitus positions on perfusion lung scintigrams with Tc-99 m macro-aggregated albumin, applying the method devised by Tanaka et al (Eur J Nucl Med 17: 320-326, 1990). Utilizing a scintillation camera coupled to a minicomputer system, changes in the distribution of pulmonary blood flow caused by gravitational effects, namely, changes in the total count ratios for the right lung versus the left lung in the right and left lateral decubitus positions (R/L), were obtained for 44 patients with lung disease, 95 patients with valvular heart disease, and 23 normal subjects. Mean standard deviation in the R/L ratios was 3.09±1.28 for the normal subjects, 1.97±0.89 for the patients with lung disease, and 1.59±0.59 for the patients with valvular heart disease. The R/L ratios correlated with mean pulmonary arterial pressure and cardio-thoracic ratios in the lung disease and valvular heart disease groups, with pulmonary arteriolar resistance in the former, and with pulmonary capillary wedge pressure in the latter. Defining pulmonary hypertension (>20 mmHg) as an R/L ratio of less than 1.81, which is the mean-1 standard deviation for normal subjects, the sensitivity and the specificity of the R/L ratio for the diagnosis of pulmonary hypertension were 62.9% and 76.2%, respectively, for the lung disease patients, and 80.3% and 61.8%, respectively, for the valvular heart disease patients. This method seems to be useful for the pathophysiologic evaluation of pulmonary perfusion in cases of lung disease and valvular heart disease. (author)

Frog eat frog: exploring variables influencing anurophagy

OpenAIRE

Measey, G. John; Vimercati, Giovanni; de Villiers, F. Andr?; Mokhatla, Mohlamatsane M.; Davies, Sarah J.; Edwards, Shelley; Altwegg, Res

2015-01-01

Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet ...

Confluence of depression and acute psychological stress among patients with stable coronary heart disease: effects on myocardial perfusion.

Science.gov (United States)

Burg, Matthew M; Meadows, Judith; Shimbo, Daichi; Davidson, Karina W; Schwartz, Joseph E; Soufer, Robert

2014-10-30

Depression is prevalent in coronary heart disease (CHD) patients and increases risk for acute coronary syndrome (ACS) recurrence and mortality despite optimal medical care. The pathways underlying this risk remain elusive. Psychological stress (PS) can provoke impairment in myocardial perfusion and trigger ACS. A confluence of acute PS with depression might reveal coronary vascular mechanisms of risk. We tested whether depression increased risk for impaired myocardial perfusion during acute PS among patients with stable CHD. Patients (N=146) completed the Beck Depression Inventory-I (BDI-I), a measure of depression linked to recurrent ACS and post-ACS mortality, and underwent single-photon emission computed tomography myocardial perfusion imaging at rest and during acute PS. The likelihood of new/worsening impairment in myocardial perfusion from baseline to PS as a function of depression severity was tested. On the BDI-I, 41 patients scored in the normal range, 48 in the high normal range, and 57 in the depressed range previously linked to CHD prognosis. A BDI-I score in the depressed range was associated with a significantly greater likelihood of new/worsening impairment in myocardial perfusion from baseline to PS (odds ratio =2.89, 95% CI: 1.26 to 6.63, P=0.012). This remained significant in models controlling ACS recurrence/mortality risk factors and medications. There was no effect for selective serotonin reuptake inhibitor medications. Depressed patients with CHD are particularly susceptible to impairment in myocardial perfusion during PS. The confluence of PS with depression may contribute to a better understanding of the depression-associated risk for ACS recurrence and mortality. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

In situ Raman study of redox state changes of mitochondrial cytochromes in a perfused rat heart

DEFF Research Database (Denmark)

Brazhe, Nadezda; Treiman, Marek; Faricelli, Barbara

2013-01-01

We developed a Raman spectroscopy-based approach for simultaneous study of redox changes in c-and b-type cytochromes and for a semiquantitative estimation of the amount of oxygenated myoglobin in a perfused rat heart. Excitation at 532 nm was used to obtain Raman scattering of the myocardial...... surface of the isolated heart at normal and hypoxic conditions. Raman spectra of the heart under normal pO2 demonstrate unique peaks attributable to reduced c-and b-type cytochromes and oxymyoglobin (oMb). The cytochrome peaks decreased in intensity upon FCCP treatment, as predicted from uncoupling...

1H nuclear magnetic resonance studies of sarcoplasmic oxygenation in the red cell-perfused rat heart

OpenAIRE

Jelicks, L.A.; Wittenberg, B.A.

1995-01-01

The proximal histidine N delta H proton of deoxymyoglobin experiences a large hyperfine shift resulting in its 1H nuclear magnetic resonance (NMR) signal appearing at approximately 76 ppm (at 35 degrees C), downfield of the diamagnetic spectral region. 1H NMR of this proton is used to monitor sarcoplasmic oxygen pressure in isolated perfused rat heart. This method monitors intracellular oxygenation in the whole heart and does not reflect oxygenation in a limited region. The deoxymyoglobin res...

Frog eat frog: exploring variables influencing anurophagy.

Science.gov (United States)

Measey, G John; Vimercati, Giovanni; de Villiers, F André; Mokhatla, Mohlamatsane M; Davies, Sarah J; Edwards, Shelley; Altwegg, Res

2015-01-01

Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet. Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

Frog eat frog: exploring variables influencing anurophagy

Directory of Open Access Journals (Sweden)

G. John Measey

2015-08-01

Full Text Available Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested.Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis.Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet.Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

The effect of adrenaline and high Ca2+ on the mechanical performance and oxygen consumption of the isolated perfused trout (Oncorhynchus mykiss) heart

DEFF Research Database (Denmark)

Rytter, Dorte; Gesser, Hans

2007-01-01

In heart muscle from mammals, catecholamines frequently evoke an oxygen waste and reduce efficiency. It was examined if this also applies to fish in which heart muscle activity is often restricted by oxygen availability. In the isolated perfused heart from rainbow trout, adrenaline (0.5 micro...

Prognostic study of risk stratification among Japanese patients with ischemic heart disease using gated myocardial perfusion SPECT: J-ACCESS study

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Nakajima, Kenichi; Kusuoka, Hideo; Yamashina, Akira; Nishimura, Shigeyuki

2008-01-01

Although the prognostic value of myocardial perfusion imaging using gated single photon emission computed tomography (SPECT) for predicting major cardiac events has been evaluated, little is known about the relevance of this procedure to the Japanese population. A total of 4,031 consecutive Japanese patients with suspected or confirmed ischemic heart diseases were registered at 117 hospitals in the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT investigation. Gated stress/rest myocardial perfusion SPECT was performed and the patients were followed up for 3 years. Segmental perfusion scores and quantitative gated SPECT results were calculated. Major cardiac events were defined as cardiac death, nonfatal myocardial infarction, and severe heart failure. During the 3-year follow-up, cardiac death (n = 57) and nonfatal myocardial infarction (n = 39) occurred in 96 patients (2.4%/3 years) when hard events were the endpoints. When severe heart failure was included as an endpoint, major cardiac events that developed in 175 patients (4.3%/3 years) comprised cardiac death (n = 45), nonfatal myocardial infarction (n = 37), and severe heart failure (n = 93). Normal and severely abnormal summed stress score values were associated with low (2.31%/3 years) and high (9.21%/3 years) rates of major cardiac events, respectively. Rates of major cardiac events were significantly higher in patients with ejection fraction (EF) <45% than in those with EF 45% or higher (16.55 vs 2.94%/3 years; P < 0.001). The incidence of major cardiac events within 3 years was also significantly higher among patients with high end-systolic volumes. The major event rates were similar among nondiabetic patients with and diabetic patients without prior myocardial infarction at 5.06% and 5.73%/3 years, respectively. Cardiac event rates were significantly lower in the Japanese than in the USA and European populations. However, large myocardial perfusion defects and

Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

Directory of Open Access Journals (Sweden)

H. Rodriguez-Angulo

2013-01-01

Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

Skin perfusion pressure as an indicator of tissue perfusion in valvular heart surgery: Preliminary results from a prospective, observational study.

Directory of Open Access Journals (Sweden)

Young Song

Full Text Available Hemodynamic management aims to provide adequate tissue perfusion, which is often altered during cardiac surgery with cardiopulmonary bypass (CPB. We evaluated whether skin perfusion pressure (SPP can be used for monitoring of adequacy of tissue perfusion in patients undergoing valvular heart surgery. Seventy-two patients undergoing valve replacement were enrolled. SPP and serum lactate level were assessed after anaesthesia induction (baseline, during CPB, after CPB-off, end of surgery, arrival at intensive care unit, and postoperative 6 h. Lactate was further measured until postoperative 48 h. Association of SPP with lactate and 30-day morbidity comprising myocardial infarction, acute kidney injury, stroke, prolonged intubation, sternal infection, reoperation, and mortality was assessed. Among the lactate levels, postoperative 6 h peak value was most closely linked to composite of 30-day morbidity. The SPP value during CPB and its % change from the baseline value were significantly associated with the postoperative 6 h peak lactate (r = -0.26, P = 0.030 and r = 0.47, P = 0.001, respectively. Optimal cut-off of % decrease in SPP during CPB from baseline value for the postoperative 6 h hyperlactatemia was 48% (area under curve, 0.808; 95% confidence interval (CI, 0.652-0.963; P = 0.001. Decrease in SPP >48% during CPB from baseline value was associated with a 12.8-fold increased risk of composite endpoint of 30-day morbidity (95% CI, 1.48-111.42; P = 0.021 on multivariate logistic regression. Large decrease in SPP during CPB predicts postoperative 6 h hyperlactatemia and 30-day morbidity, which implicates a promising role of SPP monitoring in the achievement of optimal perfusion during CPB.

Skin perfusion pressure as an indicator of tissue perfusion in valvular heart surgery: Preliminary results from a prospective, observational study.

Science.gov (United States)

Song, Young; Soh, Sarah; Shim, Jae-Kwang; Park, Kyoung-Un; Kwak, Young-Lan

2017-01-01

Hemodynamic management aims to provide adequate tissue perfusion, which is often altered during cardiac surgery with cardiopulmonary bypass (CPB). We evaluated whether skin perfusion pressure (SPP) can be used for monitoring of adequacy of tissue perfusion in patients undergoing valvular heart surgery. Seventy-two patients undergoing valve replacement were enrolled. SPP and serum lactate level were assessed after anaesthesia induction (baseline), during CPB, after CPB-off, end of surgery, arrival at intensive care unit, and postoperative 6 h. Lactate was further measured until postoperative 48 h. Association of SPP with lactate and 30-day morbidity comprising myocardial infarction, acute kidney injury, stroke, prolonged intubation, sternal infection, reoperation, and mortality was assessed. Among the lactate levels, postoperative 6 h peak value was most closely linked to composite of 30-day morbidity. The SPP value during CPB and its % change from the baseline value were significantly associated with the postoperative 6 h peak lactate (r = -0.26, P = 0.030 and r = 0.47, P = 0.001, respectively). Optimal cut-off of % decrease in SPP during CPB from baseline value for the postoperative 6 h hyperlactatemia was 48% (area under curve, 0.808; 95% confidence interval (CI), 0.652-0.963; P = 0.001). Decrease in SPP >48% during CPB from baseline value was associated with a 12.8-fold increased risk of composite endpoint of 30-day morbidity (95% CI, 1.48-111.42; P = 0.021) on multivariate logistic regression. Large decrease in SPP during CPB predicts postoperative 6 h hyperlactatemia and 30-day morbidity, which implicates a promising role of SPP monitoring in the achievement of optimal perfusion during CPB.

Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic heart disease

International Nuclear Information System (INIS)

Takeishi, Yasuchika; Chiba, Junya; Abe, Shinya

1992-01-01

Thallium-201 ( 201 Tl) myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201 Tl was administered in a separate vein at the end of third minutes of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and spical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201 Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314±2377 vs. 10360±2148, p 201 Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease. (author)

MYOCARDIAL PERFUSION ASSESSMENT IN FORECASTING EFFECT OF CORONARY ANGIOPLASTY IN PATIENTS WITH ISCHEMIC CHRONIC HEART FAILURE

Directory of Open Access Journals (Sweden)

A. B. Mironkov

2015-01-01

Full Text Available Aim. To define influence of the left ventricle (LV perfusion defects on the clinical status dynamics after coronary angioplasty in patients with the expressed myocardium dysfunction of ischemic etiology. Materials and methods. Examined 86 patients (81 men and 5 women aged from 46 to 73 years before and in 2–3 days after percutaneous coronary intervention with diagnosis: CAD, CHF with NYHA class III–IV, echocardiography parameters of LV: ejection fraction less than 40%, end-diastolic volume is more than 200 ml. Perfusion defects of myocardium estimated with use of ECG-gated single photon emission computed tomography. Predictors were defined: perfusion defects on LV apex (in score, perfusion defects in the area of LAD, LCx and RCA (%, the LV global perfusion defects (in score and %. Results. In 42% of cases 6-minute walk test increased to 3 times; The NYHA class decreased by 2 classes (group 1. In 28 cases 6-minute walk test increased to 2 times and the NYHA class decreased on 1 class. In 22 patients 6-minute walk test increased less than 50% of reference values and there was no dynamics NYHA class (50 patients of the group 2. Initial extent of LV global perfusion defects in group 1 – 41,2 ± 4,0%, in group 2 – 58,3 ± 2,4% (р = 0,0004. Similar values are received for perfusion indicators in the area of LAD and the LV apex. Prevalence of myocardial perfusion defects at rest reflects prevalence of a cardiosclerosis in a cardiac muscle. Conclusion. Degree of LV myocardial perfusion defects in patients with the expressed heart failure of ischemic etiology is the key indicator influencing clinical efficiency of coronary angioplasty. Critical size for definition of the favorable forecast of revascularization are 60% and more perfusion defects testifying that in a cardiac muscle the focal cardiosclerosis prevails over the functioning myocardium. 

Dosimetry in myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

2011-07-01

This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

Dosimetry in myocardial perfusion imaging

International Nuclear Information System (INIS)

Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C.

2011-01-01

This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

31P nuclear magnetic resonance surface coil study of ischemic preconditioned isolated perfused rat heart

International Nuclear Information System (INIS)

Yan Yongbin; Luo Xuechun; Zhang Riqing; Wang Xiaoyin; Zuo Lin; Liu Wei

2000-01-01

ischemic preconditioning (IPC) will protect the heart from the damage caused by a subsequent long ischemia period. 31 P spectra of isolated perfused rat heart measured by the nuclear magnetic resonance (NMR) surface coil technique can be used to continually, dynamically and noninvasively obtain metabolism information. This paper explores the IPC mechanisms by NMR. This study shows that IPC has no effect on enhancing the ATP and PCr levels during reperfusion but makes significantly slows and smooths the changes of intracellular pH and ATP during ischemia periods. The ATP and PCr recovery rate of the IPC group after ischemia is significantly higher than that of the control group. In conclusion, the above results support that IPC can protect the rat heart by reducing damage during the ischemia period

Compartment analysis of 125I-labelled albumin washout from coronary vessels of isolated perfused hearts

International Nuclear Information System (INIS)

Cheng Eap Ng; Seh-Hoon Song

1978-01-01

Albumin labelled with 125 I was used as a tracer to investigate the washout kinetics of plasma from the coronary circulation of isolated perfused feline hearts. Compartmentalization with experimental results showed at least two compartments. The model was compared with a three-compartment model found previously for red blood cells. The results indicate that there is a separation of plasma and RBC in the coronary microcirculation. (author)

Absolute concentration determination of phosphorus metabolites in the Langendorff-perfused rabbit heart by phosphorus-31 nuclear magnetic resonance

International Nuclear Information System (INIS)

Gard, J.K.

1984-01-01

The concentrations of mobile high energy phosphorus metabolites and intracellular pH of Langendorff-perfused rabbit heart have been determined under control and reduced flow conditions. Absolute concentration determination was accomplished by Lorentzian lineshape analysis after development of hexachlorocyclotriphosphazene as an external intensity standard. Hearts were demonstrated to be biochemically and physiologically competent during control perfusion periods and compromised during reduced flow conditions by independent hemodynamic and metabolic measurements coincident with the NMR experiment. Reduction in perfusate flow from 20 mL/min to 5.0 mL/min (25% flow) or 2.5 mL/min (12.5% flow) demonstrated a fall in phosphocreatine and adenosine triphosphate concentrations, a rise in cytosolic inorganic phosphate concentrations, and drops in pH. Subsequent recovery upon reflow was observed. The derived values for the free concentration of ADP were very close to the reported values of the Michaelis constant for respiratory stimulation, implicating a regulatory role for this molecule in cellular respiration. Strong evidence that the creating kinase reaction was in equilibrium in the 25% flow study was seen. The NMR observable correlated closely with myocardial performance and biochemical indices of metabolic function, and supported the use of phosphocreatine as an indicator of current metabolic integrity

A new clinical tool for the quantification of myocardial CT perfusion imaging in patients with suspected Ischemic Heart Disease

Energy Technology Data Exchange (ETDEWEB)

Ruiz Muñoz, A.; Dux-Santoy Hurtado, L.; Rodriguez Palomares, J.L.; Piella Fenoy, G.

2016-07-01

In the clinical practice, the evaluation of myocardial perfusion by using Computed Tomography (CT) Imaging is usually performed visually or semi-quantitatively. The scarcity of quantitative perfusion data not always allows a proper diagnose of patients which are suspected of suffering from some diseases, such as Ischemic Heart Disease (IHD). In this work, a clinical tool for the automatic quantification of myocardial perfusion in patients with suspected IHD is proposed. Myocardial perfusion is assessed based on a combined diagnosis protocol (CT/CTP protocol) which involves the acquisition of two contrastenhanced CT images, one obtained at rest and another acquired under pharmacological stress. The clinical tool allows the automatic quantification of perfusion in different myocardial segments defined according to the 16-AHA-segmentation model of the left ventricle, by providing the mean of Hounsfield Units in those regions. Based on this analysis, the clinicians can compare the values at baseline and at hyperemia, and they can better determine hypoperfusion defects in patients with IHD. The validation of the clinical tool was performed by comparing automatic and manual perfusion measurements of 10 patients with suspected IHD who were previously assessed with Single Photon Emission Computed Tomography (SPECT) for perfusion analysis. A strong linear correlation was found between the automatic and manual results. Afterwards, perfusion defects obtained from CT/CTP protocol were compared to perfusion defects from SPECT, to assess the applicability of this clinical tool for the diagnosis of IHD. (Author)

Perfusion-induced changes in cardiac contractility depend on capillary perfusion.

Science.gov (United States)

Dijkman, M A; Heslinga, J W; Sipkema, P; Westerhof, N

1998-02-01

The perfusion-induced increase in cardiac contractility (Gregg phenomenon) is especially found in heart preparations that lack adequate coronary autoregulation and thus protection of changes in capillary pressure. We determined in the isolated perfused papillary muscle of the rat whether cardiac muscle contractility is related to capillary perfusion. Oxygen availability of this muscle is independent of internal perfusion, and perfusion may be varied or even stopped without loss of function. Muscles contracted isometrically at 27 degrees C (n = 7). During the control state stepwise increases in perfusion pressure resulted in all muscles in a significant increase in active tension. Muscle diameter always increased with increased perfusion pressure, but muscle segment length was unaffected. Capillary perfusion was then obstructed by plastic microspheres (15 microns). Flow, at a perfusion pressure of 66.6 +/- 26.2 cmH2O, reduced from 17.6 +/- 5.4 microliters/min in the control state to 3.2 +/- 1.3 microliters/min after microspheres. Active tension developed by the muscle in the unperfused condition before microspheres and after microspheres did not differ significantly (-12.8 +/- 29.4% change). After microspheres similar perfusion pressure steps as in control never resulted in an increase in active tension. Even at the two highest perfusion pressures (89.1 +/- 28.4 and 106.5 +/- 31.7 cmH2O) that were applied a significant decrease in active tension was found. We conclude that the Gregg phenomenon is related to capillary perfusion.

Patient-specific coronary blood supply territories for quantitative perfusion analysis

Science.gov (United States)

Zakkaroff, Constantine; Biglands, John D.; Greenwood, John P.; Plein, Sven; Boyle, Roger D.; Radjenovic, Aleksandra; Magee, Derek R.

2018-01-01

Abstract Myocardial perfusion imaging, coupled with quantitative perfusion analysis, provides an important diagnostic tool for the identification of ischaemic heart disease caused by coronary stenoses. The accurate mapping between coronary anatomy and under-perfused areas of the myocardium is important for diagnosis and treatment. However, in the absence of the actual coronary anatomy during the reporting of perfusion images, areas of ischaemia are allocated to a coronary territory based on a population-derived 17-segment (American Heart Association) AHA model of coronary blood supply. This work presents a solution for the fusion of 2D Magnetic Resonance (MR) myocardial perfusion images and 3D MR angiography data with the aim to improve the detection of ischaemic heart disease. The key contribution of this work is a novel method for the mediated spatiotemporal registration of perfusion and angiography data and a novel method for the calculation of patient-specific coronary supply territories. The registration method uses 4D cardiac MR cine series spanning the complete cardiac cycle in order to overcome the under-constrained nature of non-rigid slice-to-volume perfusion-to-angiography registration. This is achieved by separating out the deformable registration problem and solving it through phase-to-phase registration of the cine series. The use of patient-specific blood supply territories in quantitative perfusion analysis (instead of the population-based model of coronary blood supply) has the potential of increasing the accuracy of perfusion analysis. Quantitative perfusion analysis diagnostic accuracy evaluation with patient-specific territories against the AHA model demonstrates the value of the mediated spatiotemporal registration in the context of ischaemic heart disease diagnosis. PMID:29392098

[Biological testing of water with different structural states in rats and frogs].

Science.gov (United States)

Farashchuk, N F; Mikhaylova, R I; Telenkova, O G

2014-01-01

The effect of water samples with different structural states on some physiological indices of white laboratory rats, 5 groups of 10 animals (5 females and 5 males) and frogs has been studied. The investigation was performed for 1 month. For the determination of the content of liquid crystal associates (LCA) in water samples there was used the dilatometric method, the performance of experimental animals was studied by the swimming test (up to total fatigue). The performed experiment on growing rats with the use of water with varying degrees of structuredness showed that according to the weight gain there were optimal water "Lekor" and tap water, treated with Bioptron (the content of the structured fraction is 5.06 +/- 0.09% and 6.9 +/- 0.23%, respectively). On physical performance the best indices were in animals consumed water treated with the Bioptron lamp. In performance of experiments on frogs it was found that cardiac function in animals under experimental conditions over time weakens spontaneously: heart rate and cardiac output decline. Therefore, the effect of different water samples on the cardiac function was assessed on the intensity of its decrease for 15 minutes. In the experimental study of the effect of water with different content of LCA on heart rate and cardiac output of the frog it was found that the optimum level of structuredness of water is within the range of 5.06 +/- 0.09% (in water "Lekor") - 6.9 +/- 0.23% (tap water treated with Bioptron). All the other water samples, the content of nanocrystals in which was below or above this range, has a pronounced inhibitory effect on the heart performance of the frog.

Comparative study of adenosine and exercise 201Tl myocardial perfusion tomographic imaging for detection of coronary heart disease

International Nuclear Information System (INIS)

Wang Xiong

1997-01-01

To compare diagnostic accuracy of adenosine and exercise 201 Tl myocardial perfusion tomographic imaging for detection of coronary heart disease (CHD) in patients with a normal rest ECG and no history of myocardial infarction, 81 patients with CHD and 10 normal control subjects underwent adenosine myocardial perfusion imaging, exercise nuclide myocardial perfusion imaging was performed in 117 patients with CHD and 16 normal control subjects, two groups also had coronary arteriography. Both exercise and adenosine testing parameters were analysed. It is shown: 1) The sensitivity and specificity for detection of CHD were 79% vs 80% for adenosine group and 81% vs 81% for exercise myocardial perfusion imaging group respectively. There was no significant difference in comparison with two matched groups (χ 2 = 1.13, χ 2 = 0.18, χ 2 = 0.12, P>0.05). 2) Side effects induced by adenosine accounted for 89% of patients, all symptoms were mild and disappeared quickly after the termination of the study except in 2 cases withdrawal of infusion needed because of severe angina pectoris. Adenosine myocardial perfusion imaging is a safe and sensitive method for detection of CHD. The diagnostic value of adenosine test is similar to that of exercise myocardial perfusion imaging and particularly useful in evaluating patients unable to perform exercise test or achieve adequate level of exercise

Scintigraphy of the heart using sup(99m)Tc diphosphonate in combination with selective coronary perfusion scintigraphy and coronaroangiography

International Nuclear Information System (INIS)

Neumann, G.; Trenckmann, H.; Duck, H.J.; Katzschmann, R.; Neugebauerova, A.; Schneider, G.; Gottschild, D.

1980-01-01

In 45 patients with ischemic heart disease the results obtained by myocardial scintigraphy using technetium-99m diphosphonate (Tc-99m-DP) were compared with those obtained at selective coronary angiography and selective coronary perfusion scintigraphy. The cumulation of activity in the heart muscle was seen in twelve patients. This group is analyzed in the present paper in more detail. The ventriculographic examination of the left ventricle showed disturbed motility of the wall in six patients, of whom five had a positive myocardial scintigram. In view of this, myocardial scintigraphy using Tc-99m-DP may be considered a complementary, non-invasive method for proving significant disturbances of the motility of the heart wall. Positive myocardial scintigrams were also found in angna pectoris, in a patient after aorto-coronary bypass, in cardiomyopathy and myocarditis. In view of the fact that myocardial scintigraphy using Tc-99m-DP is capable of proving disturbances of cells of the heart muscle taking place at the moment, conclusions can be drawn as to the activity in the heart muscle. It further follows that myocardial scintigraphy may be significant in indicating the aorto-coronary bypass. We failed to prove an unequivocal correlation between myocardial scintigraphy, the number of sclerotically changed coronary vessels and the degree of their narrowing. An immediate relationship could not be proved between the extent of perfusion disturbance and the results of myocardial scintigraphy

Post ischemic reperfusion and anoxic perfusion in the isolated heart: alteration in distribution of radionuclides and in protein synthesis

Energy Technology Data Exchange (ETDEWEB)

Schreiber, S S; Oratz, M; Rothschild, M A [Veterans Administration Hospital, New York (USA)

1980-12-01

Reperfusion after ischemia and perfusion with total anoxia were studied in the isolated guinea pig heart model, Deprivation of oxygen in both situations resulted in a marked shift of circulation from the left to the right ventricle, with markedly increased spaces of distribution of sup(99m)Tc radionuclides and albumin in the latter. In view of the complexities of measuring protein synthesis during ischemia, continuous anoxic perfusion was used to evaluate this parameter in anoxic induced arrest. There was a profound fall in protein synthesis associated with this arrest, accompanied by a fall in ATP, creatine phosphate, glycogen, potassium, and a rise in lactate production. The fall in protein synthesis was more marked in the left ventricle. The changes in synthesis were almost completely prevented by initiating cardiac arrest with high K/sup +/ (16 meq/l) at the same time as anoxia; energy metabolism remained near normal, and recovery of contractility was nearly complete. The studies demonstrated the differences in vascular distribution between the ventricles after ischemia or with perfusion anoxia, the possible difference in availability of substrate to the two ventricles under these conditions, as well as the difference in protein synthetic response, and further support the protective effect of potassium induced arrest on the hypoxic heart.

Distribution, structure and projections of the frog intracardiac neurons.

Science.gov (United States)

Batulevicius, Darius; Skripkiene, Gertruda; Batuleviciene, Vaida; Skripka, Valdas; Dabuzinskiene, Anita; Pauza, Dainius H

2012-05-21

Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 μm. Average total length of processes from soma and hillock was less, 118 ± 27 μm and 109 ± 24 μm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

Goal-directed-perfusion in neonatal aortic arch surgery.

Science.gov (United States)

Cesnjevar, Robert Anton; Purbojo, Ariawan; Muench, Frank; Juengert, Joerg; Rueffer, André

2016-07-01

Reduction of mortality and morbidity in congenital cardiac surgery has always been and remains a major target for the complete team involved. As operative techniques are more and more standardized and refined, surgical risk and associated complication rates have constantly been reduced to an acceptable level but are both still present. Aortic arch surgery in neonates seems to be of particular interest, because perfusion techniques differ widely among institutions and an ideal form of a so called "total body perfusion (TBP)" is somewhat difficult to achieve. Thus concepts of deep hypothermic circulatory arrest (DHCA), regional cerebral perfusion (RCP/with cardioplegic cardiac arrest or on the perfused beating heart) and TBP exist in parallel and all carry an individual risk for organ damage related to perfusion management, chosen core temperature and time on bypass. Patient safety relies more and more on adequate end organ perfusion on cardiopulmonary bypass, especially sensitive organs like the brain, heart, kidney, liver and the gut, whereby on adequate tissue protection, temperature management and oxygen delivery should be visualized and monitored.

Variation in Perfusion Strategies for Neonatal and Infant Aortic Arch Repair: Contemporary Practice in the STS Congenital Heart Surgery Database.

Science.gov (United States)

Meyer, David B; Jacobs, Jeffrey P; Hill, Kevin; Wallace, Amelia S; Bateson, Brian; Jacobs, Marshall L

2016-09-01

Regional cerebral perfusion (RCP) is used as an adjunct or alternative to deep hypothermic circulatory arrest (DHCA) for neonates and infants undergoing aortic arch repair. Clinical studies have not demonstrated clear superiority of either strategy, and multicenter data regarding current use of these strategies are lacking. We sought to describe the variability in contemporary practice patterns for use of these techniques. The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2013) was queried to identify neonates and infants whose index operation involved aortic arch repair with cardiopulmonary bypass. Perfusion strategy was classified as isolated DHCA, RCP (with less than or equal to ten minutes of DHCA), or mixed (RCP with more than ten minutes of DHCA). Data were analyzed for the entire cohort and stratified by operation subgroups. Overall, 4,523 patients (105 centers) were identified; median age seven days (interquartile range: 5.0-13.0). The most prevalent perfusion strategy was RCP (43%). Deep hypothermic circulatory arrest and mixed perfusion accounted for 32% and 16% of cases, respectively. In all, 59% of operations involved some period of RCP. Regional cerebral perfusion was the most prevalent perfusion strategy for each operation subgroup. Neither age nor weight was associated with perfusion strategy, but reoperations were less likely to use RCP (31% vs 45%, P RCP and DHCA in the RCP group was longer than the DHCA time in the DHCA group (45 vs 36 minutes, P neonates and infants. In contemporary practice, RCP is the most prevalent perfusion strategy for these procedures. Use of DHCA is also common. Further investigation is warranted to ascertain possible relative merits of the various perfusion techniques. © The Author(s) 2016.

The Effect of Heart Rate on Exposure Window and Best Phase for Stress Perfusion Computed Tomography: Lessons From the CORE320 Study.

Science.gov (United States)

Steveson, Chloe; Schuijf, Joanne D; Vavere, Andrea L; Mather, Richard T; Caton, Teresa; Mehra, Vishal; Betoko, Aisha; Cox, Christopher; Lima, Joao Ac; George, Richard T

The aim of this study is to evaluate the effect of heart rate on exposure window, best phase, and image quality for stress computed tomography perfusion (CTP) in the CORE320 study. The CTP data sets were analyzed to determine the best phase for perfusion analysis. A predefined exposure window covering 75% to 95% of the R-R cycle was used. Of the 368 patients included in the analysis, 93% received oral β blockade before the rest scan. The median heart rate during the stress acquisition was 69 bpm (interquartile range [IQR], 60-77). The median best phase was 81% (IQR, 76-90), and length of exposure window was 22% (IQR, 19-24). The best phase was significantly later in the cardiac cycle with higher heart rates (P stress scan was 5.3 mSv (IQR, 3.8-6.1). Stress myocardial CTP imaging can be performed using prospective electrocardiography triggering, an exposure window of 75% to 95%, and β-blockade resulting in good or excellent image quality in the majority (80%) of patients while maintaining a low effective radiation dose.

A comparative study of contractility of the heart ventricle in some ectothermic vertebrates

Directory of Open Access Journals (Sweden)

Sergey Kharin

2009-07-01

Full Text Available The purpose of this study was to analyze contractility of the heart ventricle in selected reptilian and amphibian species having the same ventricular excitation pattern. Systolic time intervals and indices of contractility of the heart ventricle were measured in anaesthetized frogs, snakes, and tortoises by use of polycardiography. The electromechanical delay was significantly shorter in tortoises compared with the other two species. The isovolumetric contraction time in frogs was approximately twofold longer than in reptiles. The pre-ejection period was the longest in frogs and the shortest in tortoises, whereas snakes were intermediate. The ejection time was slightly longer in tortoises compared with the other two species. The greatest isovolumetric contraction index and the smallest myocardial tension index corresponded to the frog and tortoise heart ventricle, respectively. The intrasystolic index in tortoises was significantly greater than in frogs, whereas quite similar to that in snakes. The frog ventricle had lower contractility compared with the reptilian one. Although ventricular contractility tended to be lower in snakes compared with tortoises, this difference was not statistically significant. Possible causes for these differences are discussed. We suppose a large variety in ventricular contractility among amphibian and reptilian species having the same ventricular activation pattern. This variety may be conditioned by heart anatomy, intracardiac shunting, lifestyles, and habitats. It can only be hypothesized that on the average, ventricular contractility is higher in reptiles compared with amphibians and in chelonians compared with snakes.

Role of myocardial perfusion single photon emission computed tomography in pediatric cardiology practice

Directory of Open Access Journals (Sweden)

Sundaram P

2009-01-01

Full Text Available Diagnostic and prognostic power of myocardial perfusion imaging in patients with coronary artery disease has been demonstrated with planar imaging which was further improvised with addition of gated SPECT and newer Technetium labeled myocardial perfusion tracers like SestaMIBI, Tetrofosmin. Myocardial perfusion abnormalities at rest and after stress are considered to be the best predictors of cardiac event-free survival in adults with ischemic heart disease. This article highlights various myocardial perfusion imaging (MPIradiopharmaceuticals, exercise procedures, pharmacological stress protocols, indications for MPI and myocardial perfusion patterns in children with some of the common congenital and acquired heart diseases.

Fusion of CT coronary angiography and whole-heart dynamic 3D cardiac MR perfusion: building a framework for comprehensive cardiac imaging.

Science.gov (United States)

von Spiczak, Jochen; Manka, Robert; Gotschy, Alexander; Oebel, Sabrina; Kozerke, Sebastian; Hamada, Sandra; Alkadhi, Hatem

2018-04-01

The purpose of this work was to develop a framework for 3D fusion of CT coronary angiography (CTCA) and whole-heart dynamic 3D cardiac magnetic resonance perfusion (3D-CMR-Perf) image data-correlating coronary artery stenoses to stress-induced myocardial perfusion deficits for the assessment of coronary artery disease (CAD). Twenty-three patients who underwent CTCA and 3D-CMR-Perf for various indications were included retrospectively. For CTCA, image quality and coronary diameter stenoses > 50% were documented. For 3D-CMR-Perf, image quality and stress-induced perfusion deficits were noted. A software framework was developed to allow for 3D image fusion of both datasets. Computation steps included: (1) fully automated segmentation of coronary arteries and heart contours from CT; (2) manual segmentation of the left ventricle in 3D-CMR-Perf images; (3) semi-automatic co-registration of CT/CMR datasets; (4) projection of the 3D-CMR-Perf values on the CT left ventricle. 3D fusion analysis was compared to separate inspection of CTCA and 3D-CMR-Perf data. CT and CMR scans resulted in an image quality being rated as good to excellent (mean scores 3.5 ± 0.5 and 3.7 ± 0.4, respectively, scale 1-4). 3D-fusion was feasible in all 23 patients, and perfusion deficits could be correlated to culprit coronary lesions in all but one case (22/23 = 96%). Compared to separate analysis of CT and CMR data, coronary supply territories of 3D-CMR-Perf perfusion deficits were refined in two cases (2/23 = 9%), and the relevance of stenoses in CTCA was re-judged in four cases (4/23 = 17%). In conclusion, 3D fusion of CTCA/3D-CMR-Perf facilitates anatomic correlation of coronary lesions and stress-induced myocardial perfusion deficits thereby helping to refine diagnostic assessment of CAD.

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

Energy Technology Data Exchange (ETDEWEB)

Dowdle, S.C.; Human, D.G.; Mann, M.D. (Univ. of Cape Town (South Africa))

1990-08-01

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis.

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

International Nuclear Information System (INIS)

Dowdle, S.C.; Human, D.G.; Mann, M.D.

1990-01-01

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis

Ex-vivo perfusion of donor hearts for human heart transplantation (PROCEED II): a prospective, open-label, multicentre, randomised non-inferiority trial.

Science.gov (United States)

Ardehali, Abbas; Esmailian, Fardad; Deng, Mario; Soltesz, Edward; Hsich, Eileen; Naka, Yoshifumi; Mancini, Donna; Camacho, Margarita; Zucker, Mark; Leprince, Pascal; Padera, Robert; Kobashigawa, Jon

2015-06-27

The Organ Care System is the only clinical platform for ex-vivo perfusion of human donor hearts. The system preserves the donor heart in a warm beating state during transport from the donor hospital to the recipient hospital. We aimed to assess the clinical outcomes of the Organ Care System compared with standard cold storage of human donor hearts for transplantation. We did this prospective, open-label, multicentre, randomised non-inferiority trial at ten heart-transplant centres in the USA and Europe. Eligible heart-transplant candidates (aged >18 years) were randomly assigned (1:1) to receive donor hearts preserved with either the Organ Care System or standard cold storage. Participants, investigators, and medical staff were not masked to group assignment. The primary endpoint was 30 day patient and graft survival, with a 10% non-inferiority margin. We did analyses in the intention-to-treat, as-treated, and per-protocol populations. This trial is registered with ClinicalTrials.gov, number NCT00855712. Between June 29, 2010, and Sept 16, 2013, we randomly assigned 130 patients to the Organ Care System group (n=67) or the standard cold storage group (n=63). 30 day patient and graft survival rates were 94% (n=63) in the Organ Care System group and 97% (n=61) in the standard cold storage group (difference 2·8%, one-sided 95% upper confidence bound 8·8; p=0·45). Eight (13%) patients in the Organ Care System group and nine (14%) patients in the standard cold storage group had cardiac-related serious adverse events. Heart transplantation using donor hearts adequately preserved with the Organ Care System or with standard cold storage yield similar short-term clinical outcomes. The metabolic assessment capability of the Organ Care System needs further study. TransMedics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Visualization of myocardial perfusion derived from coronary anatomy

NARCIS (Netherlands)

Termeer, M.A.; Bescos, J.O.; Breeuwer, M.; Vilanova, A.; Gerritsen, F.A.; Gröller, M.E.; Nagel, Eike

2008-01-01

Visually assessing the effect of the coronary artery anatomy on the perfusion of the heart muscle in patients with coronary artery disease remains a challenging task. We explore the feasibility of visualizing this effect on perfusion using a numerical approach. We perform a computational simulation

Improvements in the technique of vascular perfusion-fixation employing a fluorocarbon-containing perfusate and a peristaltic pump controlled by pressure feedback

DEFF Research Database (Denmark)

Rostgaard, J; Qvortrup, Klaus; Poulsen, Steen Seier

1993-01-01

A new improved technique for whole-body perfusion-fixation of rats and other small animals is described. The driving force is a peristaltic pump which is feedback regulated by a pressure transducer that monitors the blood-perfusion pressure in the left ventricle of the heart. The primary perfusate...... to cannulate the heart; the outer and inner barrels of the cannula are connected to the peristaltic pump and to the pressure transducer, respectively. The tissue oxygen tension in the rat is monitored by a subcutaneous oxygen electrode. Measurements showed that tissue hypoxia/anoxia did not develop before......-fixative is composed of a blood substitute--13.3% oxygenated fluorocarbon FC-75--in 0.05 M cacodylate buffer (pH 7.4) with a 2% glutaraldehyde. The secondary perfusate-fixative is composed of 2% glutaraldehyde in 0.05 M cacodylate buffer (pH 7.4) with 20 mM CaCl2. A double-barrelled, self-holding cannula is used...

Dependence of Ca outflow and depression of frog myocardium contraction on ryodipine concentration.

Science.gov (United States)

Narusevicius, E; Gendviliene, V; Macianskiene, R; Hmelj-Dunai, G; Velena, A; Duburs, G

1988-02-01

The effect of ryodipine on calcium outflow from tissues, on contraction force, the duration of action potentials and the relaxation phase time-constant in the contraction cycles of myocardial strips was studied using frog heart preparations. It was found that calcium outflow (delta Ca) as a function on ryodipine concentration can be represented as: (formula; see text) A linear correlation exists between Ca2+, contraction blocking and the shortening of the action potential in the presence of various ryodipine concentrations. Ryodipine (10(-5) mol/l) decreased the relaxation time-constant by about 20% as compared to controls. It was concluded that calcium outflow from myocardial tissues in response to ryodipine is due to blockade of calcium entry into the cells and their output through the Na+--Ca2+ exchange system. Frog heart myocardial contractions are essentially under the control of calcium entry through sarcolemmal calcium channels.

Frog Statistics

Science.gov (United States)

Whole Frog Project and Virtual Frog Dissection Statistics wwwstats output for January 1 through duplicate or extraneous accesses. For example, in these statistics, while a POST requesting an image is as well. Note that this under-represents the bytes requested. Starting date for following statistics

Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

Science.gov (United States)

Rittman, S.E.; Muths, E.; Green, D.E.

2003-01-01

The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

Adipose-Derived Cell Construct Stabilizes Heart Function and Increases Microvascular Perfusion in an Established Infarct

Science.gov (United States)

Nguyen, Quang T.; Touroo, Jeremy S.; Aird, Allison L.; Chang, Raymond C.; Ng, Chin K.; Hoying, James B.; Williams, Stuart K.

2013-01-01

We have previously shown that myocardial infarction (MI) immediately treated with an epicardial construct containing stromal vascular fraction (SVF) from adipose tissue preserved microvascular function and left ventricle contractile mechanisms. In order to evaluate a more clinically relevant condition, we investigated the cardiac recovery potential of an SVF construct implanted onto an established infarct. SVF cells were isolated from rat adipose tissue, plated on Vicryl, and cultured for 14 days. Fischer-344 rats were separated into MI groups: (a) 6-week MI (MI), (b) 6-week MI treated with an SVF construct at 2 weeks (MI SVF), (c) 6-week MI with Vicryl construct at 2 weeks (MI Vicryl), and (d) MI 2wk (time point of intervention). Emax, an indicator of systolic performance and contractile function, was lower in the MI and MI Vicryl versus MI SVF. Positron emission tomography imaging (18F-fluorodeoxyglucose) revealed a decreased percentage of relative infarct volume in the MI SVF versus MI and MI Vicryl. Total vessel count and percentage of perfusion assessed via immunohistochemistry were both increased in the infarct region of MI SVF versus MI and MI Vicryl. Overall cardiac function, percentage of relative infarct, and percentage of perfusion were similar between MI SVF and MI 2wk; however, total vessel count increased after SVF treatment. These data suggest that SVF treatment of an established infarct stabilizes the heart at the time point of intervention by preventing a worsening of cardiac performance and infarcted volume, and is associated with increased microvessel perfusion in the area of established infarct. PMID:24106337

Effects of smoking on lung uptake of 201Tl during exercise myocardial perfusion imaging

International Nuclear Information System (INIS)

Ouyang Wei; He Guorong; Liu Jinhua

2004-01-01

Objective: To investigate the influence of smoking on lung uptake of 201 Tl during myocardial perfusion imaging. Methods: Ninety-two healthy subjects, with normal 201 Tl myocardial perfusion imaging findings but no evidence of left ventricular hypertrophy and pulmonary disease, were divided into three groups, smoker, nonsmoker and quitted smoker groups. Exercise/delay 201 Tl myocardial perfusion imaging was performed on all subjects included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: Both the lung/heart ratios during exercise in smoker (0.40 ± 0.07, F=10.635, P 201 Tl lung/heart ratios in smokers are higher than in nonsmokers and this must be kept in mind when 201 Tl lung/heart ratios are used clinically, even in quitted smokers

Tc99m-sestamibi dosimetry in myocardial perfusion imaging

International Nuclear Information System (INIS)

Toledo, Janine M.; Trindade, Bruno M.; Campos, Tarcisio P.R.

2015-01-01

This paper addressed myocardial perfusion imaging providing a spatial dosimetric investigation of the 99m Tc-radiopharmaceutical dose distribution at the myocardium. Radiological data manipulation was performed in order to create a computational voxel model of the heart. A set of images obtained by thoracic angiotomography and abdominal aorta was set up providing anatomic and functional information for heart modeling in SISCODES code. A homogeneous distribution of 99m Tc was assumed into the cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissues were performed on the MCNP - Monte Carlo Code. The spatial dose distribution in the heart model is displayed as well as the dose versus volume histogram of the heart muscle. The present computational tools can generate spatial doses distribution in myocardial perfusion imaging. Specially, the dosimetry performed elucidates imparted dose distribution in the myocardial muscle per unit of injected 99m Tc activity, which can contribute to future deterministic effect investigations. (author)

Regulation of cardiac C-protein phosphorylation

International Nuclear Information System (INIS)

Titus, F.L.

1985-01-01

Molecular mechanisms of cardiac sympathetic and parasympathetic responses were addressed by studying subcellular changes in protein phosphorylation, cAMP-dependent protein kinase activity and protein phosphatase activity in frog hearts. B-adrenergic agonists increased and muscarinic cholinergic agonists decreased [ 32 P]phosphate incorporation into C-protein, a thick filament component. Regulation of protein phosphatase activity by Iso and methacholine (MCh) was assayed using extracts of drug treated frog hearts and [ 32 P]phospho-C-protein as substrate. Total phosphatase activity decreased 21% in extracts from hearts perfused with 0.1 μM Iso and 17% in hearts exposed to Iso plus 1 μM methacholine. This decrease reflected decreased phosphatase-2A activity. No changes in total phosphatase activity were measurable in broken cells treated with Iso or MCh. The results suggest adrenergic stimulation changes contractile activity in frog hearts by activating cAMP-dependent protein kinase associated with particulate cellular elements and inactivating soluble protein phosphatase-2A. This is the first demonstration of coordinated regulation of these enzymes by B-adrenergic agonists favoring phosphorylation of effector proteins. Coordinated regulation by methacholine in the presence of Iso was not observed

Dietary red palm oil supplementation reduces myocardial infarct size in an isolated perfused rat heart model

Directory of Open Access Journals (Sweden)

Esterhuyse Adriaan J

2010-06-01

Full Text Available Abstract Background and Aims Recent studies have shown that dietary red palm oil (RPO supplementation improves functional recovery following ischaemia/reperfusion in isolated hearts. The main aim of this study was to investigate the effects of dietary RPO supplementation on myocardial infarct size after ischaemia/reperfusion injury. The effects of dietary RPO supplementation on matrix metalloproteinase-2 (MMP2 activation and PKB/Akt phosphorylation were also investigated. Materials and methods Male Wistar rats were divided into three groups and fed a standard rat chow diet (SRC, a SRC supplemented with RPO, or a SRC supplemented with sunflower oil (SFO, for a five week period, respectively. After the feeding period, hearts were excised and perfused on a Langendorff perfusion apparatus. Hearts were subjected to thirty minutes of normothermic global ischaemia and two hours of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining. Coronary effluent was collected for the first ten minutes of reperfusion in order to measure MMP2 activity by gelatin zymography. Results Dietary RPO-supplementation decreased myocardial infarct size significantly when compared to the SRC-group and the SFO-supplemented group (9.1 ± 1.0% versus 30.2 ± 3.9% and 27.1 ± 2.4% respectively. Both dietary RPO- and SFO-supplementation were able to decrease MMP2 activity when compared to the SRC fed group. PKB/Akt phosphorylation (Thr 308 was found to be significantly higher in the dietary RPO supplemented group when compared to the SFO supplemented group at 10 minutes into reperfusion. There was, however, no significant changes observed in ERK phosphorylation. Conclusions Dietary RPO-supplementation was found to be more effective than SFO-supplementation in reducing myocardial infarct size after ischaemia/reperfusion injury. Both dietary RPO and SFO were able to reduce MMP2 activity, which suggests that MMP2 activity does not play a major role in

Optimization of perfusion studies using Atropine

International Nuclear Information System (INIS)

Alvarado, A.N.; Valle, V.M.; Montoya, M.J.; Eskenazi, E.S.; Montiel, M.L.; Cueto, C.C.

2002-01-01

The studies of myocardial perfusion require an adequate stress; exercise or pharmacological. Every day, more pharmacological studies are performed, specially in some group of patients (women, AMI, etc). There some drugs that are used for this purpose, as adenosine and dobutamine. However, their cost and the lack of availability and infrastructure in our country do not allow there routinely use. We performed dipyridamol as a pharmacological stress, however in some patients there is a doubt regarding if the pharmacological effect was adequate. Atropine is a drug that is frequently used for different purpose and it is well know its tachycardic response. We present and alternative technique, using dipyridamol-atropine as a protocol of stress perfusion study. Our goal was to correlate the standard dipyridamol -thallium perfusion study and the dipyridamol -atropine-perfusion in patients with chronic coronary disease. We evaluated 6 patients (5 males) with stable angina and chronic coronary disease. A standard dipyridamol-thallium study was performed in all of them. Dipyridamole was administered intravenously at a rate of 0.14 mg/kg/min over 6 min for a total of 0.84 mg/kg body weight. Blood pressure, heart rate, EKG and symptoms were monitored before, during and after the pharmacological infusion. Two minutes after the infusion was completed, the radiotracer was injected intravenously. In the next 6 months, without any modification of the clinical situation (symptoms and therapy) a new dipyridamol study was performed, using 1 mg of atropine after the administration of dipyridamol. There were no differences in the collateral effects and we observed and average increase of 30% in the heart rate in relation with the study using dipyridamol alone. The addition of atropine to the standard dipyridamol perfusion study is safe, cheaper and improved the detection of perfusion defects in patients with coronary artery disease

Respiratory control in the glucose perfused heart. A /sup 31/P NMR and NADH fluorescence study

Energy Technology Data Exchange (ETDEWEB)

Katz, L A; Koretsky, A P; Balaban, R S

1987-09-14

The phosphate metabolites, adenosine diphosphate (ADP), inorganic phosphate (P/sub i/), and adenosine triphosphate (ATP), are potentially important regulators of mitochondrial respiration in vivo. However, previous studies on the heart in vivo and in vitro have not consistently demonstrated an appropriate correlation between the concentration of these phosphate metabolites and moderate changes in work and respiration. Recently, mitochondrial NAD(P)H levels have been proposed as a potential regulator of cardiac respiration during alterations in work output. In order to understand better the mechanism of respiratory control under these conditions, we investigated the relationship between the phosphate metabolites, the NAD(P)H levels, and oxygen consumption (Q/sub O(sub 2)/) in the isovolumic perfused rat heart during alterations in work output with pacing. ATP, creatine phosphate (CrP), P/sub i/ and intracellular pH were measured using /sup 31/P NMR. Mitochondrial NAD(P)H levels were monitored using spectrofluorometric techniques. 33 refs.; 3 figs.; 2 tabs.

A Unifying model of perfusion and motion applied to reconstruction of sparsely sampled free-breathing myocardial perfusion MRI

DEFF Research Database (Denmark)

Pedersen, Henrik; Ólafsdóttir, Hildur; Larsen, Rasmus

2010-01-01

The clinical potential of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is currently limited by respiratory induced motion of the heart. This paper presents a unifying model of perfusion and motion in which respiratory motion becomes an integral part of myocardial perfusion...... quantification. Hence, the need for tedious manual motion correction prior to perfusion quantification is avoided. In addition, we demonstrate that the proposed framework facilitates the process of reconstructing DCEMRI from sparsely sampled data in the presence of respiratory motion. The paper focuses primarily...... on the underlying theory of the proposed framework, but shows in vivo results of respiratory motion correction and simulation results of reconstructing sparsely sampled data....

The SLE heart in scintigraphic diagnostics

International Nuclear Information System (INIS)

Rottensteiner, J.

2001-01-01

Investigation of SLE-heart of 14 patients with 201Ti-SPECT and 18 FDG-SPECT and comparison with clinical and laboratory parameters. Results: SLE-patients with unspecific heart symptoms show in spite of sufficiently perfusion in 201Ti-SPECT considerable defects in 18-FDG. Interpretation: cause of the defects in FDG in a disturbed glucose metabolism independent of perfusion. (boteke)

A capillary-based perfusion phantom for simulation of brain perfusion for MRI

International Nuclear Information System (INIS)

Maciak, A.; Kronfeld, A.; Mueller-Forell, W.; Wille, C.; Kempski, O.; Stoeter, P.

2010-01-01

Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

Predictors of abnormal heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT

International Nuclear Information System (INIS)

De Souza Leao Lima, R.; Machado, L.; Azevedo, A.B.; De Lorenzo, A.

2011-01-01

The objective of this study was to identify predictors of abnormal HR response to dipyridamole (DIP) in patients undergoing myocardial perfusion SPECT (MPS). Patients with a reduced heart rate (HR) response to DIP have higher cardiac mortality, but the mechanism is unknown. We studied 432 patients who underwent dual-isotope gated MPS. DIP (0.56 mg/kg) was infused over 4 min, and Tc-99m tetrofosmin was injected 3 min after the end of the infusion. MPS was semiquantitatively interpreted. Left ventricular ejection fraction (LVEF) and volumes were automatically calculated. The population was categorized into quartiles according to HR ratio, and characteristics in each quartile were compared. Logistic regression analysis was performed to identify predictors of abnormal HR response, using the lowest quartile as the independent variable. Patients with abnormal HR response were more frequently without chest pain, with a history of chronic renal failure and taking digoxin. Baseline HR was higher and had fewer symptoms during stress. The stress and rest perfusion defects were greater, but reversibility was not; in addition, LVEF was lower. Multivariable logistic regression analysis demonstrated that the independent predictors of abnormal HR response were baseline HR and low LVEF. LV dysfunction is an independent predictor of abnormal HR response to DIP, and the association between low LVEF and low HR ratio may explain the link between abnormal HR ratio and increased mortality. (author)

Altered carnitine transport in pressure-overload hypertrophied rat hearts

International Nuclear Information System (INIS)

O'Rourke, B.; Foster, K.; Reibel, D.K.

1986-01-01

The authors have previously observed reduced carnitine levels in hypertrophied hearts of rats subjected to aortic constriction. In an attempt to determine the mechanism for reduced myocardial carnitine content, carnitine transport was examined in isolated perfused hearts. Hearts were excised from sham-operated and aortic-constricted rats 3 weeks following surgery and perfused at 60 mm Hg aortic pressure with buffer containing various concentrations of L- 14 C-carnitine. Carnitine uptake by control and hypertrophied hearts was linear throughout 30 minutes of perfusion with 40 μM carnitine. Total carnitine uptake was significantly reduced by 25% in hypertrophied hearts at each time point examined. The reduction in uptake by hypertrophied hearts was also evident when hearts were perfused with 100 or 200 μM carnitine. When 0.05 mM mersalyl acid was included in the buffer to inhibit the carrier-mediated component of transport, no difference in carnitine uptake was observed indicating that the transport of carnitine by diffusion was unaltered in the hypertrophied myocardium. Carrier-mediated carnitine uptake (total uptake - uptake by diffusion) was significantly reduced by approximately 40% in hypertrophied hearts at all concentrations examined. Thus, the reduction in carnitine content in the pressure-overload hypertrophied rat heart appears to be due to a reduction in carrier-mediated carnitine uptake by the heart

Myocardial stress perfusion magnetic resonance: initial experience in a pediatric and young adult population using regadenoson

International Nuclear Information System (INIS)

Noel, Cory V.; Krishnamurthy, Ramkumar; Krishnamurthy, Rajesh; Moffett, Brady

2017-01-01

Dipyridamole and adenosine are traditional pharmacological stressors for myocardial perfusion. Regadenoson, a selective adenosine A2A agonist, has a lower side effect profile with lower incidence of bronchospasm and bradycardia. There is a growing need for myocardial perfusion assessment within pediatrics. There is no report on the utility of regadenoson as a stress agent in children. To observe the safety and feasibility of regadenoson as a pharmacologic stressor for perfusion cardiac MR in a pilot cohort of pediatric patients weighing more than 40 kg who have congenital heart disease and pediatric acquired heart disease. We reviewed our initial experience with regadenoson stress cardiac MR in 31 pediatric patients 15.8 ± 1.7 years (range 12-22 years) with congenital heart disease and acquired heart disease. Mean patient weight was 60 ± 15 kg (range of 40-93 kg). All patients underwent cardiac MR because of concern for ischemia. The cohort included a heterogeneous group of patients at a pediatric institution with potential risk for ischemia. Subjects' heart rate and blood pressure were monitored and pharmacologic stress was induced by injection of 400 mcg of regadenoson. We evaluated their hemodynamic response and adverse effects using changes in vital signs and onset of symptoms. A pediatric cardiologist and radiologist qualitatively assessed myocardial perfusion and viability images. One child was unable to complete the stress perfusion portion of the examination, but did complete the remaining portion of the CMR. Resting heart rate was 72 ± 14 beats per minute (bpm) and rose to peak of 124 ± 17 bpm (95 ± 50% increase, P < 0.005) with regadenoson. Image quality was considered good or diagnostic in all cases. Three patients had irreversible perfusion defects. Four patients had reversible perfusion defects. Nine of the patients underwent cardiac catheterization with angiography and the findings showed excellent agreement. Regadenoson might be a safe and

Myocardial stress perfusion magnetic resonance: initial experience in a pediatric and young adult population using regadenoson

Energy Technology Data Exchange (ETDEWEB)

Noel, Cory V. [Baylor College of Medicine, Department of Pediatric Cardiology, Houston, TX (United States); Texas Children' s Hospital, Department of Pediatric Cardiology, Houston, TX (United States); Krishnamurthy, Ramkumar; Krishnamurthy, Rajesh [Texas Children' s Hospital, Department of Radiology, Houston, TX (United States); Moffett, Brady [Texas Children' s Hospital, Department of Pharmacology, Houston, TX (United States)

2017-03-15

Dipyridamole and adenosine are traditional pharmacological stressors for myocardial perfusion. Regadenoson, a selective adenosine A2A agonist, has a lower side effect profile with lower incidence of bronchospasm and bradycardia. There is a growing need for myocardial perfusion assessment within pediatrics. There is no report on the utility of regadenoson as a stress agent in children. To observe the safety and feasibility of regadenoson as a pharmacologic stressor for perfusion cardiac MR in a pilot cohort of pediatric patients weighing more than 40 kg who have congenital heart disease and pediatric acquired heart disease. We reviewed our initial experience with regadenoson stress cardiac MR in 31 pediatric patients 15.8 ± 1.7 years (range 12-22 years) with congenital heart disease and acquired heart disease. Mean patient weight was 60 ± 15 kg (range of 40-93 kg). All patients underwent cardiac MR because of concern for ischemia. The cohort included a heterogeneous group of patients at a pediatric institution with potential risk for ischemia. Subjects' heart rate and blood pressure were monitored and pharmacologic stress was induced by injection of 400 mcg of regadenoson. We evaluated their hemodynamic response and adverse effects using changes in vital signs and onset of symptoms. A pediatric cardiologist and radiologist qualitatively assessed myocardial perfusion and viability images. One child was unable to complete the stress perfusion portion of the examination, but did complete the remaining portion of the CMR. Resting heart rate was 72 ± 14 beats per minute (bpm) and rose to peak of 124 ± 17 bpm (95 ± 50% increase, P < 0.005) with regadenoson. Image quality was considered good or diagnostic in all cases. Three patients had irreversible perfusion defects. Four patients had reversible perfusion defects. Nine of the patients underwent cardiac catheterization with angiography and the findings showed excellent agreement. Regadenoson might be a safe and

From frog integument to human skin: dermatological perspectives from frog skin biology

NARCIS (Netherlands)

Haslam, I.S.; Roubos, E.W.; Mangoni, M.L.; Yoshizato, K.; Vaudry, H.; Kloepper, J.E.; Pattwell, D.M.; Maderson, P.F.A.; Paus, R.

2014-01-01

For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a

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

Internal pigment cells respond to external UV radiation in frogs.

Science.gov (United States)

Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

2016-05-01

Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

Role of glycolysis in maintenance of the action potential duration and contractile activity in isolated perfused rat heart.

Science.gov (United States)

Opie, L H; Tuschmidt, R; Bricknell, O; Girardier, L

1980-01-01

1. Changing substrates from glucose to pyruvate in paced isolated rat hearts, perfused by the Langendorff technique at 65 cm H2O with a Krebs-Henseleit bicarbonate buffer, produced effects which are opposite to those of ouabain treatment: negative inotropy, decreased work efficiency, hyperpolarization, increased maximum rate of rise and amplitude of the action potential, increased conduction velocity. 2. All the effects resulting from perfusion with pyruvate can be reversed by adding ouabain at a concentration of 100 microM. 3. The correlation between various tissue metabolises and change in contractile force (delta F), rate of tension development [maximum + (dF/dt)] and rate of relaxation [maximum -(dF/dt)] was studied by multiple linear regression. No significant correlation was found with either glycogen content and tissue lactate or with cAMP and cGMP. A weak negative correlation was found with ATP and phosphocreatine. The strongest correlation was found 76 to 807 nM/g in passing from glucose- to pyruvate-containing perfusion solution. 4. In vitro tests performed with a solution containing high energy phosphates and magnesium at concentrations equal to their calculated values in the cytosol (pH 7.0) showed that a significant negative correlation exists between citrate concentration (range: 1 and 1500 M) and free calcium concentration in the micromole range. 5. It is concluded that the effects of pyruvate (non glucose substrate) perfusion could be mediated by a decrease in cytosolic-free calcium resulting from an increase in intracellular citrate. The observation that all these effects can be reversed by ouabain is taken as a circumstantial evidence of a common mechanism.

Dynamic CT myocardial perfusion imaging

International Nuclear Information System (INIS)

Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

2016-01-01

Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

Dynamic CT myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

2016-10-15

Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

Radioisotope heart examination during exercise to diagnose ischemic heart disease

International Nuclear Information System (INIS)

Farsky, S.

1986-01-01

The radioisotope exercise test is discussed and its benefits characterized for the diagnosis of ischemic heart disease, namely the use of 99m Tc in scintiscanning heart ventricles and of 201 Tl in scintiscanning myocardial perfusion. The exercise ventricular function and perfusion scintigraphies are compared with the common exercise ECG examination, and their superior sensitivity and specificity emphasized. Considering the constraints of scintigraphic imaging, indications are outlined for patients including those with suspect serious ischemic heart disease in whom the exercise ECG test has been negative or inconclusive, patients with the so-called nondiagnostic ECG, patients with atypical symptoms, and healthy individuals for whom the exercise ECG test indicated with respect to their occupation has been positive. Both radionuclide imaging techniques are complementary and are shown to be valuable not only in improving the diagnosis of ischemic heart disease but also in identifying the high-risk patients in whom cardiac surgery is to be considered. (L.O.)

Changes in perfusion and fatty acid metabolism of rat heart with autoimmune myocarditis

Energy Technology Data Exchange (ETDEWEB)

Tsujimura, Eiichiro; Kusuoka, Hideo; Fukuchi, Kazuki; Hasegawa, Shinji; Yutani, Kenji; Nishimura, Tsunehiko [Osaka Univ., Suita (Japan). Biomedical Research Center; Hori, Masatsugu; Hirono, Satoru; Izumi, Tohru

2000-10-01

To elucidate the change in perfusion and aerobic metabolism in myocarditis, tissue counting and dual tracer ex vivo autoradiography with Tl-201 and free fatty acid analog, I-123- or I-125-labeled (p-iodophenyl)-methyl-pentadecanoic acid (BMIPP), were performed in rats with myocarditis induced by immunization with cardiac myosin. Inflammatory damage was classified histologically. At the acute stage (2-4 weeks after the antigen-injection), total heart uptakes of Tl and BMIPP and the ratio (BMIPP/Tl) were significantly reduced in myocarditis rats (N=15) compared with the controls (N=12). Myocardial distribution of Tl and BMIPP was not homogeneous. Relative uptake of Tl and BMIPP (N=9, 128 regions) was gradually decreased with the extent of inflammation, and the regional BMIPP/Tl was smaller than the control. At the subacute stage (7 weeks after the antigen-injection), total Tl uptake in myocarditis rats (N=5) recovered to the control level (N=4), but that of BMIPP was still significantly lower than the control. BMIPP/Tl was still significantly lower in myocarditis. Myocardial distribution of Tl and BMIPP recovered to be more homogeneous. Relative uptake of Tl and BMIPP (N=6, 78 regions) still gradually but significantly decreased with the extent of inflammation. Regional BMIPP/Tl was still depressed in myocarditis. These results indicate that myocardial perfusion and aerobic metabolism were discrepant and heterogeneously suppressed with severe inflammation during the acute stages, but the difference decreases with time. Examination with Tl-201 and BMIPP may provide information about the severity of myocarditis. (author)

Myocardial perfusion scintigraphy with thallium-201 - principle and method

International Nuclear Information System (INIS)

Dressler, J.

1981-01-01

Since from the cardiological and cardio-surgical aspects non-invasive methods practicable in the diagnostics of regional myocardial blood perfusion are claiming priority, the myocardial perfusion scintigraphy with thallium 201 has gained more and more importance in the diagnostics of coronary heart diseases. Although radiothallium because of its nucleo-physical characteristics is not regarded as ideal radiopharmaceutical, it is at present, because of its potassium-analogue biokinetics the best radiopharmaceutical to represent the regional coronary perfusion distribution, the vitality and configuration of the heart muscle non-invasively. With careful clinical indication and under consideration of the physico-technical limitations, the informative value provided by the serial scintigraphy with thallium 201 is greater than that provided by the excercise ECG. Various possibilities for solving the problem of quantitative analysis of the myocardial scintigrams have been given. Up to the present day a standardised evaluation procedure corresponding to that of the visual scintigram interpretation has not yet found general acceptance. (orig.) [de

Comparison of adenosine stress and exercise stress 201Tl myocardial perfusion imaging for diagnosis of coronary heart disease

International Nuclear Information System (INIS)

Chen Guibing; Wu Hua; Jiang Ningyi; Liu Sheng; Lu Xianping; Liang Jiugen; Zhang Hong

2007-01-01

Objective: The aim of this study was to compare the diagnostic values of adenosine and exercise stress 201 Tl myocardial perfusion imaging for detecting coronary heart disease (CHD). Methods: 41 patients with suspected CHD were randomly divided into two groups. In one group adenosine stress was submitted, the exercise stress myocardial SPECT was performed in another. Coronary angiography (CAG) was performed in each patient within 2 weeks before or after SPECT. The result of CAG was taken as 'gold standard of CHD. They compared the diagnostic value of two methods. Results: In adenosine group, the sensitivity, specificity, positive predictive value, negative predictive value, accuracy are 92.86%, 57.14%, 81.25%, 80.00%, 80.95% respectively. In exercise stress group, are 100%, 60.0%, 71.43%, 100%, 80.00% respectively. Detection rates of coronary artery lesions were 66.67% and 72.22% in two groups respectively. Conclusion Adenosine stress testing and exercise stress testing 201 Tl myocardial perfusion imaging may provide similar value for detection of CHD. (authors)

Evaluating optimal superficial limb perfusion at different angles using non-invasive micro-lightguide spectrophotometry.

Science.gov (United States)

Darmanin, Geraldine; Jaggard, Matthew; Hettiaratchy, Shehan; Nanchahal, Jagdeep; Jain, Abhilash

2013-06-01

It is common practice to elevate the limbs postoperatively to reduce oedema and hence optimise perfusion and facilitate rehabilitation. However, elevation may be counterproductive as it reduces the mean perfusion pressure. There are no clear data on the optimal position of the limbs even in normal subjects. The optimal position of limbs was investigated in 25 healthy subjects using a non-invasive micro-lightguide spectrophotometry system "O2C", which indirectly measures skin and superficial tissue perfusion through blood flow, oxygen saturation and relative haemoglobin concentration. We found a reduction in skin and superficial tissue blood flow of 17% (p=0.0001) on arm elevation (180° shoulder flexion) as compared to heart level and an increase in skin and superficial tissue blood flow of 25% (p=0.02) on forearm elevation of 45°. Lower limb skin and superficial tissue blood flow decreased by 15% (p=0.004) on elevation to 47 cm and by 70% on dependency (p=0.0001) compared to heart level. However, on elevation of the lower limb there was also a 28% reduction in superficial venous pooling (p=0.0001) compared to heart level. In the normal limb, the position for optimal superficial perfusion of the upper limb is with the arm placed at heart level and forearm at 45°. In the lower limb the optimal position for superficial perfusion would be at heart level. However, some degree of elevation may be useful if there is an element of venous congestion. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Isolated working heart: description of models relevant to radioisotopic and pharmacological assessments

International Nuclear Information System (INIS)

Depre, Christophe

1998-01-01

Isolated heart preparations are used to study physiological and metabolic parameters of the heart independently of its environment. Several preparations of isolated perfused heart are currently used, mainly the retrograde perfusion system and the working heart model. Both models allow investigations of the metabolic regulation of the heart in various physiological conditions (changes in workload, hormonal influences, substrate competition). These systems may also reproduce different pathological conditions, such as ischemia, reperfusion and hypoxia. Quantitation of metabolic activity can be performed with specific radioactive tracers. Finally, the effects of various drugs on cardiac performance and resistance to ischemia can be studied as well. Heart perfusion also revealed efficient methods to determine the tracer/tracee relation for radioisotopic analogues used with Positron Emission Tomography

Prey specialization and diet of frogs in Borneo

OpenAIRE

Ahlm, Kristoffer

2015-01-01

Earlier studies of the diet of frogs indicate that most adult frogs are mainly insectivorous. Overall, frogs are viewed more as generalists than specialists in terms of their diet. However, despite earlier studies, there are still gaps in our knowledge regarding what frogs tend to eat and the degree of specialization. The aim of this study was to investigate the diet choice of frogs in a tropical ecosystem. The present study was conducted in a well-known hotspot for frogs with 66 of the 156 k...

Tale of 2 cities: heart transplant progress

International Nuclear Information System (INIS)

Iturralde, M.P.; Novitzky, D.

1986-01-01

Heart transplantation, today an accepted modality in managing selected terminal heart disease patients, still suffers from the major complications of acute rejection and infection. Joint research at Pretoria and Cape Town shows that the use of radionuclide techniques allows non-invasive, reliable and rapid quantification of ventricular function and myocardial perfusion for the diagnosis and management of heart transplant patients. Blood pool scintigraphy, using the in vivo labelling with sup(99m) Tc, was used to measure left ventricular volumes. Myocardial perfusion scintigraphy using Tl 201 was also performed in some patients

Taking radionuclides to heart

International Nuclear Information System (INIS)

Kleynhans, P.H.T.; Lotter, M.G.; Van Aswegen, A.; Minnaar, P.C.; Iturralde, M.; Herbst, C.P.; Marx, D.

1980-01-01

Ischaemic heart disease is a main cause of death in South Africa. Non-invasive ECG gated radionuclide bloodpool imaging plays an increasingly useful role in the evalution of the function of the heart as a pump, and the extent of heart muscle perfusion defects is further pinpointed by invasive krypton-81m studies to improve patient management

The Effect of Milrinone on Splanchnic and Cerebral Perfusion in Infants With Congenital Heart Disease Prior to Surgery: An Observational Study.

Science.gov (United States)

Bianchi, Maria Otilia; Cheung, Po-Yin; Phillipos, Ernest; Aranha-Netto, Abimael; Joynt, Chloe

2015-08-01

Despite the advancement in the postoperative care of neonates with congenital heart disease (CHD), there is little information on preoperative management of systemic and regional hemodynamics, which may be related to outcomes. We aimed to determine the preoperative effect of milrinone, a phosphodiesterase III inhibitor, on cardiac output and splanchnic and cerebral perfusion in neonates with CHD. Neonates with CHD requiring cardiac surgery were enrolled in a prospective, single-blinded study once a clinical decision of starting milrinone (0.75 μg/kg per minute intravenously) using institutional criteria was made. Demographic and clinical variables and outcomes were recorded. Combined cardiac output and measures of splanchnic (superior mesenteric and celiac arteries) and cerebral (anterior and middle cerebral arteries) perfusion were determined by Doppler studies at 0, 6, 24, and 48 h after milrinone infusion. Investigators were unaware of intervention time points and patients in analyzing blood flow measurements. Seventeen term (39.2 ± 1.3 weeks) neonates were included with hypoplastic left-sided heart syndrome (78.5%) as the most common diagnosis. Combined cardiac output increased by 28% within 48 h (613 ± 154 vs. 479 ± 147 mL/kg per minute at baseline, P milrinone infusion (P milrinone infusion (P milrinone infusion. Milrinone increases cardiac output with concurrent effects on splanchnic and cerebral blood flows during the short-term preoperative use in neonates with CHD.

Effect of etorphine on the spontaneous and field stimulation-mediated release of norepinephrine and total tritium from perfused guinea pig hearts

International Nuclear Information System (INIS)

Anon.

1986-01-01

Isolated guinea pig hearts were prelabeled with 3 H-norepinephrine ( 3 H-NE) and perfused with modified Krebs-bicarbonate solution at 37 0 C. Spontaneous release of total 3 H and field stimulation-mediated (supramax. V., 1 Hz, 2 msec duration for a total of 60 pulses) overflow of NE and 3 H-NE were measured in the absence or presence of etorphine. Etorphine (0.1 - 100 μM) was added to the perfusion fluid 15 min. before the stimulation. To study the effect of etorphine on spontaneous release of total 3 H, etorphine was added cumulatively without stimulation. Etorphine (1.0 - 100 μM) caused a significant decrease in the stimulation-mediated overflow of NE and the inhibition was dose-related. The overflow of NE was 5.1 +/- 0.3 ng in the absence and 4.0 +/- 0.2 ng in the presence of etorphine (1.0 μM). Low concentrations of etorphine (0.1 - 1.0 μM) had no effect on the spontaneous release of total 3 H while 10 μM and 100 μM caused a 3 and 6-fold increase respectively. The results show that etorphine inhibited neuronal release of NE at a dose which had no effect on spontaneous release. It is suggested that opiate receptors might be involved in the prejunctional modulation of the release of NE in the guinea pig heart

Reduced intrinsic heart rate is associated with reduced arrhythmic susceptibility in guinea-pig heart.

Science.gov (United States)

Osadchii, Oleg E

2014-12-01

In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration.

Use of atropine in patients with submaximal heart rate during exercise myocardial perfusion SPECT.

Science.gov (United States)

De Lorenzo, Andrea; Foerster, James; Sciammarella, Maria G; Suey, Cathy; Hayes, Sean W; Friedman, John D; Berman, Daniel S

2003-01-01

Failure to reach 85% of maximal predicted heart rate (MPHR) during exercise may render a myocardial perfusion single photon emission computed tomography (MPS) study nondiagnostic for ischemia detection. Although commonly used to increase heart rate (HR) during dobutamine stress, the administration of atropine for patients failing to achieve 85% of MPHR during exercise performed for MPS is still infrequent. Patients undergoing dual-isotope MPS were considered candidates for the study when, during exercise treadmill testing, they had less than 85% of MPHR and were unable to continue because of fatigue, without an ischemic response. Forty-seven patients (aged 65.3 +/- 12.5 years, 78.7% men) received atropine (0.6-1.2 mg). Maximal HR achieved before and after atropine was 118.0 +/- 14.8 beats/min (76.3% +/- 6.2% of MPHR) and 146.4 +/- 12.6 beats/min (94.4% +/- 8.1% of MPHR), respectively (P < .001). Of patients, 44 (93.6%) reached at least 85% of MPHR after atropine and had diagnostic MPS studies. After atropine, arrhythmias occurred in 14 patients (29.8%) and other minor side effects in 1 (2.1%). Atropine allows patients initially failing to achieve 85% of MPHR during exercise to increase HR and have a diagnostic MPS study, without major complications. It may provide an alternative to pharmacologic stress for patients with a blunted HR response to exercise.

Diagnostic Value of Myocardial Perfusion SPECT with Dipyridamole in a Female Population

International Nuclear Information System (INIS)

Perez-Iruela, Juan; Pastor, Purificacion; Lumbreras, Luis; Martin, Ana M.; Ruiz, Francisco J.; Posadas, A.; Puentes, Carmen

2009-01-01

Background: Exercise stress scintigraphy is a safe procedure widely used for the diagnosis of ischemic heart disease. Pharmacologic stress testing is an important alternative. The delayed presentation of ischemic heart disease in women, together with a lower diagnostic accuracy of exercise stress testing in this population, has generated interest in the potential benefits provided by myocardial perfusion imaging tests. Objective: To determine the diagnostic value of myocardial perfusion images with 99m Tc-tetrofosmin in a one day protocol after a pharmacologic stress with dipyridamole in a female population, and the relation with the coronary territories using coronary angiography as a reference technique. Material and Methods: In total, 149 clinical charts of women with suspected ischemic heart disease undergoing myocardial perfusion imaging tests and coronary angiography were retrospectively analyzed. Results: Sensitivity and specificity were 94% (93.47%-94.53%) and 82% (80.94%-83.06%), respectively. Values of sensitivity and specificity according to coronary territories were 71.62% (70.88%-72.36%) and 76% (75.27%-76.73%) for the left anterior descending (LAD) artery, 69.09% (68.11%-70.07%) and 76.84% (76.26%-77.42%) for the left circumflex (LCx) coronary artery, and 87.23% (86.11%-88.36%) and 74.51% (73.97%-75.05%) for the right coronary artery (RCA), respectively. Conclusion: Myocardial perfusion scintigraphy with 99m Tc-tetrofosmin and dipyridamole using a one day stress-rest protocol has high sensitivity and specificity for the diagnosis of ischemic heart disease in women. (authors) [es

Leukocyte filtration and miniature perfusion during arrested heart CABG on a Jehovah's Witness patient.

Science.gov (United States)

Sutton, Steven W; Duncan, Michael A; Chase, Virginia A; Cheung, Edson H; Hamman, B L

2004-11-01

Bloodless surgery and a reduction in the use of allogeneic blood products has long been the standard of care in medicine. Many individuals in our communities have demanded this form of surgical treatment for personal and religious reasons. On 6 December 2002, a 72-year-old male patient was admitted to our institution as a critical air flight transfer. The patient's height was 190.5 cm and weight was 59.3 kg (body surface area 1.83 m2). His preliminary diagnosis was chest pain with myocardial infarction as evidenced by elevated blood cardiac isoenzymes. His principle diagnosis was subendocardial infarction with paroxysmal ventricular tachycardia. Cardiac catheterization was performed and demonstrated severe triple vessel disease with an ejection fraction of 30%. He was evaluated and accepted as a candidate for coronary artery bypass grafting. Multidisciplinary consultation concluded that a safe and effective method of perioperative treatment would involve the use of arrested heart support with cold blood cardioplegia using a low prime miniature perfusion circuit as no blood products would be considered for use. Additionally, the combined modalities of perfusion interventions to minimize hemodilution consisted of intraoperative autologous blood collection totaling 500 mL and rapid autologous priming of the miniature perfusion circuit. The miniature perfusion system was a low prime Cardiovention (Santa Clara, CA) CORx device which includes a hollow-fiber oxygenator and integral centrifugal pump with a surface area of 1.2 m2. This system also incorporates an air sensing solenoid which triggers rapid air evacuation in a bolus range of 1 mL or greater. Kinetic venous drainage is another feature of this device as the centrifugal pump is integrated into the oxygenator. We believed that a miniature extracorporeal circuit would enhance the desired clinical outcome as opposed to the risk of: (1) off-pump coronary artery bypass (OPCAB) approach and the concern of emergent

Interactions of the heart and the liver

DEFF Research Database (Denmark)

Møller, Søren; Bernardi, Mauro

2013-01-01

There is a mutual interaction between the function of the heart and the liver and a broad spectrum of acute and chronic entities that affect both the heart and the liver. These can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting...... the heart and the liver at the same time. In chronic and acute cardiac hepatopathy, owing to cardiac failure, a combination of reduced arterial perfusion and passive congestion leads to cardiac cirrhosis and cardiogenic hypoxic hepatitis. These conditions may impair the liver function and treatment should...... be directed towards the primary heart disease and seek to secure perfusion of vital organs. In patients with advanced cirrhosis, physical and/or pharmacological stress may reveal a reduced cardiac performance with systolic and diastolic dysfunction and electrophysical abnormalities termed cirrhotic...

Beneficial effects of hyperosmotic perfusion in the myocardium after ischemia/reperfusion injury in isolated rat hearts Efeitos benéficos da perfusão hiperosmótica no miocárdio após lesão isquemia/reperfusão em corações isolados de ratos

Directory of Open Access Journals (Sweden)

Yong Cao

2013-03-01

Full Text Available OBJECTIVE: A simple method to reduce the ischemia/reperfusion injury that can accompany cardiac surgery would have great clinical value. This study was to investigate the effect of hyperosmotic perfusion on ischemia/reperfusion injury in isolated perfused rat hearts. METHOD: Forty male Sprague-Dawley rats were randomly divided either to have their isolated hearts perfused with normal osmotic buffer or buffer made hyperosmotic by addition of glucose. Hearts were then subjected to 30 min ischemia followed by 30 min reperfusion. Coronary flow, time to ischemic arrest, reperfusion arrhythmia, and ventricular function were recorded. Creatine phosphokinase leakage into the coronary artery, and myocardial content and activity of superoxide dismutase and catalase were also examined. RESULTS: Rat hearts with hyperosmotic perfusion showed higher coronary flow, a prolonged time to ischemic arrest (10.60 vs. 5.63 min, POBJETIVO: Um método simples para reduzir a lesão de isquemia/reperfusão que pode acompanhar a cirurgia cardíaca teria grande valor clínico. O objetivo deste estudo foi investigar o efeito da perfusão hiperosmótica na isquemia/reperfusão em corações isolados de ratos perfundidos. MÉTODOS: Quarenta ratos machos Sprague-Dawley foram divididos aleatoriamente e tiveram os seus corações isolados perfundidos com tampão osmótico normal ou tampão hiperosmótico com a adição de glucose. Os corações foram então submetidos a 30 minutos de isquemia, seguida de 30 min de reperfusão. O fluxo coronariano, tempo de parada isquêmica, arritmia de reperfusão e da função ventricular foram registrados. Vazamento creatinofosfoquinase na artéria coronária, o miocárdio e atividade de superóxido dismutase e catalase foram também examinados. RESULTADOS: Crações de ratos com perfusão hiperosmótica apresentaram maior fluxo coronariano, tempo prolongado de parada isquêmica (10,60 vs. 5,63 min, P<0,005, menor pontuação de reperfus

Assmentment of myocardial perfusion by magnetic resonance imaging: on the way to clinical application

International Nuclear Information System (INIS)

Fischer, S.E.; Lorenz, C.H.

1997-01-01

Magnetic resonance imaging detects the flow of contrast - enhanced blood and even allows the quantitative assessment of myocardial perfusion. The clinical application of this method is being held back by the difficulties in image evaluation and the limitation of standard techniques to the acquisition of a single slice per heart beat cycle. Recent developments in scanner hardware as well as in image acquisition techniques open up the possibility of assessing myocardial perfusion over the entire heart with a spatial resolution in the range of 2 mm. As an example of such a new scanning strategy, a segmented gradient-echo recalled echo planar imaging sequence with preceding saturation is discussed and results in a patient with an infarction are presented. The clinical use of perfusion assessment covering the entire heart for the diagnosis of coronary artery disease is enhanced by the flexibility of magnetic resonance imaging for the assessment of functional cardiac parameters. (orig.) [de

Texas Heart Institute

Science.gov (United States)

... of seminars and conferences. Resources Texas Heart Institute Journal Scientific Publications Library & Learning Resources Resources for Physicians Fellowships & Residencies School of Perfusion Technology THI Spotlight Check out the ...

Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123

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Reske, S.N.; Schoen, S.; Schmitt, W.; Knopp, R.; Winkler, C.; Machulla, H.J.

1986-08-01

The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid /sup 14/C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides.

Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123

International Nuclear Information System (INIS)

Reske, S.N.; Schoen, S.; Schmitt, W.; Knopp, R.; Winkler, C.; Machulla, H.J.

1986-01-01

The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid 14 C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides. (orig.)

Isolated heart models: cardiovascular system studies and technological advances.

Science.gov (United States)

Olejnickova, Veronika; Novakova, Marie; Provaznik, Ivo

2015-07-01

Isolated heart model is a relevant tool for cardiovascular system studies. It represents a highly reproducible model for studying broad spectrum of biochemical, physiological, morphological, and pharmaceutical parameters, including analysis of intrinsic heart mechanics, metabolism, and coronary vascular response. Results obtained in this model are under no influence of other organ systems, plasma concentration of hormones or ions and influence of autonomic nervous system. The review describes various isolated heart models, the modes of heart perfusion, and advantages and limitations of various experimental setups. It reports the improvements of perfusion setup according to Langendorff introduced by the authors.

Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

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Jeong, Hwanjeong; Choi, Sehun; Han, Yeonhee [Research Institute of Chonbuk National Univ. Medical School and Hospitial, Jeonju (Korea, Republic of); Lee, Dong Soo; Lee, Hoyoung; Chung, Junekey [Seoul National Univ., Seoul (Korea, Republic of)

2013-09-15

This study aimed at identifying the predictive parameters on quantitative gated myocardial perfusion single-photon emission computed tomography (QG-SPECT) in diabetic patients with normal perfusion but impaired function. Methods Among the 533 consecutive diabetic patients, 379 patients with normal perfusion on rest Tl-201/dipyridamole-stress Tc-{sup 99m} sestamibi Gated SPECT were enrolled. Patients were grouped into those with normal post-stress left ventricular function (Group I) and those with impaired function (EF <50 or impaired regional wall motion, Group II). We investigated cardiac events and cause of death by chart review and telephone interview. Survival analysis and Cox proportional hazard model analysis were performed. Between the Group I and II, cardiac events as well as chest pain symptoms, smoking, diabetic complications were significantly different (P<0.05). On survival analysis, event free survival rate in Group II was significantly lower than in Group I (P=0.016). In univariate Cox proportional hazard analysis on overall cardiac event, Group (II over I), diabetic nephropathy, summed motion score (SMS), summed systolic thickening score (STS), numbers of abnormal segmental wall motion and systolic thickening predicted more cardiac events (P<0.05). Multivariate analysis showed that STS was the only independent predictor cardiac event. The functional parameter, especially summed systolic thickening score on QG-SPECT had prognostic values, despite normal perfusion, in predicting cardiac events in diabetic patients, and QG-SPECT provides clinically useful risk stratification in diabetic patients with normal perfusion.

Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands.

Science.gov (United States)

Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal; Gröne, Andrea; Kik, Marja J L

2017-08-31

Frog virus 3 was isolated from a strawberry poison frog ( Oophaga pumilio ) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op /2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the reference Frog virus 3 isolate. Copyright © 2017 Saucedo et al.

Mouse myocardial first-pass perfusion MR imaging

NARCIS (Netherlands)

Coolen, Bram F.; Moonen, Rik P. M.; Paulis, Leonie E. M.; Geelen, Tessa; Nicolay, Klaas; Strijkers, Gustav J.

2010-01-01

A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300-400 msec. The method was

Establishing Early Functional Perfusion and Structure in Tissue Engineered Cardiac Constructs.

Science.gov (United States)

Wang, Bo; Patnaik, Sourav S; Brazile, Bryn; Butler, J Ryan; Claude, Andrew; Zhang, Ge; Guan, Jianjun; Hong, Yi; Liao, Jun

2015-01-01

Myocardial infarction (MI) causes massive heart muscle death and remains a leading cause of death in the world. Cardiac tissue engineering aims to replace the infarcted tissues with functional engineered heart muscles or revitalize the infarcted heart by delivering cells, bioactive factors, and/or biomaterials. One major challenge of cardiac tissue engineering and regeneration is the establishment of functional perfusion and structure to achieve timely angiogenesis and effective vascularization, which are essential to the survival of thick implants and the integration of repaired tissue with host heart. In this paper, we review four major approaches to promoting angiogenesis and vascularization in cardiac tissue engineering and regeneration: delivery of pro-angiogenic factors/molecules, direct cell implantation/cell sheet grafting, fabrication of prevascularized cardiac constructs, and the use of bioreactors to promote angiogenesis and vascularization. We further provide a detailed review and discussion on the early perfusion design in nature-derived biomaterials, synthetic biodegradable polymers, tissue-derived acellular scaffolds/whole hearts, and hydrogel derived from extracellular matrix. A better understanding of the current approaches and their advantages, limitations, and hurdles could be useful for developing better materials for future clinical applications.

Basal hyperaemia is the primary abnormality of perfusion in Takotsubo cardiomyopathy

DEFF Research Database (Denmark)

Christensen, Thomas Emil; Ahtarovski, Kiril Aleksov; Bang, Lia Evi

2015-01-01

AIMS: Takotsubo cardiomyopathy (TTC) is characterized by acute completely reversible regional left ventricle (LV) akinesia and decreased tracer uptake in the akinetic region on semi-quantitative perfusion imaging. The latter may be due to normoperfusion of the akinetic mid/apical area and basal...... hyperperfusion. Our aim was to examine abnormalities of perfusion in TTC, and we hypothesized that basal hyperperfusion is the primary perfusion abnormality in the acute state. METHOD AND RESULTS: Twenty-five patients were diagnosed with TTC due to (i) acute onset of symptoms, (ii) typical apical ballooning......-on follow-up. Patients initially had severe heart failure, mid/apical oedema but no infarction, and a rise in cardiac biomarkers. On initial perfusion PET imaging, eight patients appeared to have normal, whereas 17 patients had impaired LV perfusion. In the latter, flow in the basal region was increased...

Mouse myocardial first-pass perfusion MR imaging

NARCIS (Netherlands)

Coolen, B.F.; Moonen, R.P.M.; Paulis, L.E.M.; Geelen, T.; Nicolay, K.; Strijkers, G.J.

2010-01-01

A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300–400 msec. The method was

Cloning of Interleukin-10 from African Clawed Frog (Xenopus tropicalis, with the Finding of IL-19/20 Homologue in the IL-10 Locus

Directory of Open Access Journals (Sweden)

Zhitao Qi

2015-01-01

Full Text Available Interleukin-10 (IL-10 is a pleiotropic cytokine that plays an important role in immune system. In the present study, the IL-10 gene of African clawed frog (Xenopus tropicalis was first cloned, and its expression pattern and 3D structure were also analyzed. The frog IL-10 mRNA encoded 172 amino acids which possessed several conserved features found in IL-10s from other species, including five-exon/four-intron genomic structure, conserved four cysteine residues, IL-10 family motif, and six α-helices. Real-time PCR showed that frog IL-10 mRNA was ubiquitous expressed in all examined tissues, highly in some immune related tissues including kidney, spleen, and intestine and lowly in heart, stomach, and liver. The frog IL-10 mRNA was upregulated at 24 h after LPS stimulation, indicating that it plays a part in the host immune response to bacterial infection. Another IL, termed as IL-20, was identified from the frog IL-10 locus, which might be the homologue of mammalian IL-19/20 according to the analysis results of the phylogenetic tree and the sequence identities.

Fatty acid utilization in pressure-overload hypertrophied rat hearts

International Nuclear Information System (INIS)

Reibel, D.K.; O'Rourke, B.

1986-01-01

The authors have previously shown that the levels of total tissue coenzyme A and carnitine are reduced in hypertrophied hearts of rats subjected to aortic constriction. It was therefore of interest to determine if these changes were associated with alterations in fatty acid oxidation by the hypertrophied myocardium. Hearts were excised from sham-operated and aortic-constricted rats and perfused at 10 cm H 2 O left atrial filling pressure with a ventricular afterload of 80 cm of H 2 O with buffer containing 1.2 mM 14 C-linoleate. Heart rate and peak systolic pressure were not different in control and hypertrophied hearts. 14 CO 2 production was linear in both groups of hearts between 10 and 30 minutes of perfusion. The rate of fatty acid oxidation determined by 14 CO 2 production during this time was 0.728 +/- 0.06 μmoles/min/g dry in control hearts and 0.710 +/- 0.02 μmoles/min/g dry in hypertrophied hearts. Comparable rates of fatty acid oxidation were associated with comparable rates of O 2 consumption in the two groups of hearts (39.06 +/- 3.50 and 36.78 +/- 2.39 μmoles/g dry/min for control and hypertrophied hearts, respectively). The data indicate that the ability of the hypertrophied heart to oxidize fatty acids under these perfusion conditions is not impaired in spite of significant reductions in tissue levels of coenzyme A and carnitine

31P-NMR studies on perfused mouse liver

International Nuclear Information System (INIS)

McLaughlin, A.C.; Takeda, H.; Chance, B.

1978-01-01

From a metabolic viewpoint, the most important organ in the body is the liver. In contrast to more specialized organs such as heart and kidney which perform only one major function, the liver performs a number of major metabolic functions. Two of the most important functions are the catabolism and storage of foodstuffs (in the form of glycogen) and the control of most of the constituents of the blood (in particular, the blood glucose level). Most of these functions are localized within a single type of cell. One way that the liver is able to regulate these diverse reactions is by the control of the ATP level in the cell. Encouraged by the recent success of many groups in using 31 P-NMR to provide a continuous and non-destructive monitor of ATP levels in isolated cells, skeletal muscle, and perfused organs such as heart and kidney, 31 P-NMR was used to investigate ATP levels in perfused liver of mice

Pulmonary MR angiography and perfusion imaging—A review of methods and applications

Energy Technology Data Exchange (ETDEWEB)

Johns, Christopher S.; Swift, Andrew J.; Hughes, Paul J.C. [University of Sheffield (United Kingdom); Ohno, Yoshiharu [Division of Functional and Diagnostic Imaging Research, Department of Radiology, KobeUniversity Graduate School of Medicine, Kobe, Hyogo (Japan); Schiebler, Mark [UW-Madison School of Medicine and Public Health, Madison, WI (United States); Wild, Jim M., E-mail: j.m.wild@sheffield.ac.uk [University of Sheffield (United Kingdom)

2017-01-15

Highlights: • This article represents an overview of the methodology and clinical applications of pulmonary MRA and perfusion imaging. • Both contrast enhanced and non-contrast enhanced metholodology for MRA and perfusion are covered. • The current clinical uses and future directions of MRA and MR perfusion are discussed. - Abstract: The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology. In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.

Pulmonary MR angiography and perfusion imaging—A review of methods and applications

International Nuclear Information System (INIS)

Johns, Christopher S.; Swift, Andrew J.; Hughes, Paul J.C.; Ohno, Yoshiharu; Schiebler, Mark; Wild, Jim M.

2017-01-01

Highlights: • This article represents an overview of the methodology and clinical applications of pulmonary MRA and perfusion imaging. • Both contrast enhanced and non-contrast enhanced metholodology for MRA and perfusion are covered. • The current clinical uses and future directions of MRA and MR perfusion are discussed. - Abstract: The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology. In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.

Cellular cardiomyoplasty for a patient with heart failure

International Nuclear Information System (INIS)

Zhang Fumin; Chen Yijiang; Yang Zhijian; Gao Xiang; Ma Wenzhu; Li Chuanfu; Kao, Race L.

2003-01-01

Background: A 73-year-old man with a history of myocardial infarction and hypertension for 5 years suffered heart failure (NYHA III-IV). Methods: 2D echo indicated hypokinesia at septal, left ventricular anterior wall and apical regions. Coronary angiograms demonstrated 60% stenosis in distal left main and 99% stenosis in proximal and distal left anterior descending coronary arteries (LAD). Both proximal artery and middle left circumflex coronary artery (LC) had 90% stenosis, and diffuse stenosis of right coronary artery (RC) was found. Myocardial perfusion imaging using 99m Tc-MIBI indicated defective perfusion of left ventricular apex, anterior wall and septal region and severe reduced perfusion of posterior inferior wall. Myocardial metabolic activities ( 18 F-deoxyglucose) also showed comparable reductions. After exposing the heart, LAD, LC, and RC were all completely occluded and bypass procedure could not be completed. Autologous satellite cells were implanted without any complication and the patient had an uneventful recovery. Results: During the first 2 months, he remained in heart failure, and by the third month, he gradually improved and reached NYHA II. At fifth month after the procedure, significant increased ejection fraction (37.1-48.6%) and wall movement with modest reduction of left ventricular systolic diameter (48-45 mm) were observed. Imaging with 18 F-deoxyglucose showed dramatic improvement in myocardial metabolic activity with similar improvement in myocardial perfusion ( 99m Tc-MIBI). Conclusion: This is the first successful case of cellular cardiomyoplasty without any conjunctional procedure for patient with severe coronary heart disease and heart failure

Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands

NARCIS (Netherlands)

Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal A; Gröne, Andrea; Kik, Marja J L

2017-01-01

Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

Complete genome sequence of frog virus 3, isolated from a strawberry poison frog (Oophaga pumilio) imported from nicaragua into the Netherlands

NARCIS (Netherlands)

Saucedo, Bernardo; Hughes, Joseph; Beurden, van Steven J.; Suárez, Nicolás M.; Haenen, Olga L.M.; Voorbergen-Laarman, Michal; Gröne, Andrea; Kika, Marja J.L.

2017-01-01

Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

Spatio-temporal analysis of blood perfusion by imaging photoplethysmography

Science.gov (United States)

Zaunseder, Sebastian; Trumpp, Alexander; Ernst, Hannes; Förster, Michael; Malberg, Hagen

2018-02-01

Imaging photoplethysmography (iPPG) has attracted much attention over the last years. The vast majority of works focuses on methods to reliably extract the heart rate from videos. Only a few works addressed iPPGs ability to exploit spatio-temporal perfusion pattern to derive further diagnostic statements. This work directs at the spatio-temporal analysis of blood perfusion from videos. We present a novel algorithm that bases on the two-dimensional representation of the blood pulsation (perfusion map). The basic idea behind the proposed algorithm consists of a pairwise estimation of time delays between photoplethysmographic signals of spatially separated regions. The probabilistic approach yields a parameter denoted as perfusion speed. We compare the perfusion speed versus two parameters, which assess the strength of blood pulsation (perfusion strength and signal to noise ratio). Preliminary results using video data with different physiological stimuli (cold pressure test, cold face test) show that all measures are influenced by those stimuli (some of them with statistical certainty). The perfusion speed turned out to be more sensitive than the other measures in some cases. However, our results also show that the intraindividual stability and interindividual comparability of all used measures remain critical points. This work proves the general feasibility of employing the perfusion speed as novel iPPG quantity. Future studies will address open points like the handling of ballistocardiographic effects and will try to deepen the understanding of the predominant physiological mechanisms and their relation to the algorithmic performance.

Pemanfaatan kulit kodok (bull frog

Directory of Open Access Journals (Sweden)

Muchtar Lutfie

1995-06-01

Full Text Available The objective of this study was to measure the tensile strength and the elongation of finished leather made from Bull Frog skin, so that the utilization of that leather can be specified. The samples used were twenty pieces of wet salted Bull Frog skin from East Java which have been processed to finished leather using chromosal B. and Irgatan LV as the tanning agents. Laboratory tests shawed that the average tensile strength was 177,675 Kg/Cm2 and the average elongation was 89,9%. Based on those results, it can be concluded that Bull Frog leather was suitable for leather goods such as bag, wallet, etc. so it can be used as substitute for Glace leather.

Functionality of albumin-derived perfluorocarbon-based artificial oxygen carriers in the Langendorff-heart †.

Science.gov (United States)

Wrobeln, Anna; Schlüter, Klaus D; Linders, Jürgen; Zähres, Manfred; Mayer, Christian; Kirsch, Michael; Ferenz, Katja B

2017-06-01

The aim of this study was to prove whether albumin-derived perfluorocarbon-based nanoparticles (capsules) can operate as a novel artificial oxygen carrier in a rat Langendorff-heart perfusion model. Hearts perfused with capsules showed increased left ventricular pressure and rate pressure product compared to hearts perfused with pure Krebs-Henseleit (KH)-buffer. The capsules prevented the myocardium from functional fail when in their absence a noxious ischemia was observed. Capsules did not change rheological properties of KH-buffer and could repeatedly reload with oxygen. This albumin-derived perfluorocarbon-based artificial oxygen carrier preserved the function of rat hearts due to the transport of oxygen in a satisfactory manner. Because of these positive results, the functionality of the applied capsules should be verified in living animals.

Pulmonary O2 transfer during pulsatile and non-pulsatile perfusion.

Science.gov (United States)

Hauge, A; Nicolaysen, G

1980-07-01

The importance of the perfusion pattern for the oxygen transfer has been examined in isolated rabbit lungs perfused with plasma at constant volume inflow. The lungs were ventilated with constant tidal volume and constant end-expiratory pressure. Following a standardized rise in FIO2 the rate of rise in pulmonary venous PO2 (delta PO2/delta t) was measured during alternately pulsatile and non-pulsatile perfusion in normal lungs and in lungs made edematous by elevation of left atrial pressure. In normal lungs there was no difference in delta PO2/delta t when the two modes of perfusion were compared. In edematous lungs delta PO/delta t was statistically higher during pulsatile perfusion, indicating a beneficial effect of flow- and pressure pulsations, e.g. a better distribution of V/Q ratios throughout the lungs. In a separate series of expts. the advancement of a high O2 front through the airways was measured, and the two perfusion patterns compared. Since no difference was found, we suggest that the phenomenon of "cardiogenic gas mixing" in the airways in vivo is a result of a direct action of the heart on the lungs rather than arterial pulsations.

Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis

International Nuclear Information System (INIS)

Kahan, A.; Devaux, J.Y.; Amor, B.

1986-01-01

Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined

Efficacy of ivermectin as an anthelmintic in leopard frogs.

Science.gov (United States)

Letcher, J; Glade, M

1992-02-15

Ivermectin administered cutaneously at dosages of 2 mg/kg of body weight eliminated nematode infections in leopard frogs. Three clinical trials were conducted. In the first trial, 5 groups of 11 frogs were given ivermectin IM at dosages of 0, 0.2, 0.4, 2, or 20 mg/kg. All frogs given ivermectin IM at dosages of 2.0 mg/kg or greater died. In trial 2, 44 frogs, allotted to 5 groups, were given ivermectin cutaneously at 0, 0.2, 2, or 20 mg/kg. Cutaneously administered ivermectin was not toxic at dosages up to 20 mg/kg. In trial 3, nematode infections were eliminated in all 10 frogs treated cutaneously with ivermectin at 2.0 mg/kg.

Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

Directory of Open Access Journals (Sweden)

Kiuru Aaro

2003-01-01

Full Text Available The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion analysis. According to perfusion properties, we first devise a novel mathematical function to form a perfusion model. A simple yet accurate approach is further introduced to extract cardiac systolic and diastolic phases from the heart, so that this cardiac information may be utilized to accelerate the perfusion analysis and improve its sensitivity in detecting pulmonary perfusion abnormalities. This makes perfusion analysis not only fast but also robust in computation; consequently, perfusion analysis becomes computationally feasible without using contrast media. Our clinical case studies with 52 patients show that this technique is effective for pulmonary embolism even without using contrast media, demonstrating consistent correlations with computed tomography (CT and nuclear medicine (NM studies. This fluoroscopical examination takes only about 2 seconds for perfusion study with only low radiation dose to patient, involving no preparation, no radioactive isotopes, and no contrast media.

Correlation of the myocardial perfusion corrected by attenuation with the coronariography. Preliminary results; Correlacion de la perfusion miocardica corregida por atenuacion con la coronariografia

Energy Technology Data Exchange (ETDEWEB)

Garcia C, S.E.; Garcia O, R. [Servicio de Medicina Nuclear, Centro Medico ABC, Campis Observatorio, IAP (Mexico)

2005-07-01

The attenuation that suffers the radiation in the soft tissues of the hinders the appropriate interpretation of the myocardial perfusion studies, for what have been implemented attenuation correction systems to reduce the attenuation for soft tissues and to provide myocardial perfusion images more accurate in the diagnosis of coronary illness. The objective was to evaluate the utility of an attenuation correction system (with source of Gadolinium 153) to minimize the devices that look like true defects of myocardial perfusion, caused by soft tissues (mammary tissue, thoracic wall, abdomen, left hemi diaphragm), and to compare those interpretations of the studies with the interpretations of the corresponding coronariographies. The method consists of 95 electronic files which were revised with the concept of heart catheterization, being identified 20 patients from the masculine sex to those that underwent coronariography among May 1999 and December 2002, and that they had study of myocardial perfusion in a maximum period of 3 months foresaw to the invasive procedure. (Author)

From monster to twin reversed arterial perfusion: a history of acardiac twins.

Science.gov (United States)

Obladen, Michael

2010-05-01

A human being born without heart and head, i.e., the acardius/acranius malformation, has been described since antiquity. Superstition and fear made it a mystical disorder, a sign of God's wrath. The inquisition ruled that acranic infants should not be baptized and located the soul in the brain. Acardia was not associated with twin gestation until the reports of Mery in 1720 and Winslow in 1740. In 1850, Meckel identified the pathogenetic mechanism as reversed perfusion due to large arterio-arterial and veno-venous anastomoses; he believed the heart would fail to develop or arrest during development, and the acardiac fetus would be maintained by arterial perfusion from the pump twin. In 1859, Claudius articulated that after normal initial development, the heart degenerates when reversed flow in the aorta leads to thrombosis. Today, it is assumed that both mechanisms may exist. With the advent of prenatal ultrasound diagnosis and radiofrequency ablation of the acardiac twin's circulation, it became possible to save the pump twin.

Xenopus: An Emerging Model for Studying Congenital Heart Disease

Science.gov (United States)

Kaltenbrun, Erin; Tandon, Panna; Amin, Nirav M.; Waldron, Lauren; Showell, Chris; Conlon, Frank L.

2011-01-01

Congenital heart defects affect nearly 1% of all newborns and are a significant cause of infant death. Clinical studies have identified a number of congenital heart syndromes associated with mutations in genes that are involved in the complex process of cardiogenesis. The African clawed frog, Xenopus, has been instrumental in studies of vertebrate heart development and provides a valuable tool to investigate the molecular mechanisms underlying human congenital heart diseases. In this review, we discuss the methodologies that make Xenopus an ideal model system to investigate heart development and disease. We also outline congenital heart conditions linked to cardiac genes that have been well-studied in Xenopus and describe some emerging technologies that will further aid in the study of these complex syndromes. PMID:21538812

Metabolic variations of fatty acid in isolated rat heart reperfused after a transient global ischemia

International Nuclear Information System (INIS)

Huang Gang; Michel Comet; Zhao Huiyang; Zhu Cuiying; Yuan Jimin

1998-01-01

Purpose: The fatty acid metabolism and the effect of glucose on it were studied in isolated and reperfused rat heat. Methods: 32 isolated working rat hearts were perfused in Langengdorff device with modified Krebs and were divided into normal and ischemia-reperfused group. Each group was also classified into two subgroups, modified krebs with or without glucose subgroup. 131 I-HA was injected into aorta of isolated working rat heart and then the radio-residue curves were acquired. Results: When the isolated rat hearts were perfused with krebs plus glucose, the catabolism of fatty acid was significantly decreased in normal group, but a remarkable increase of fatty acid catabolism was found in ischemia-reperfused group. While the isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat heart was less than that in normal group. Conclusions: Transient ischemia damages the catabolism of myocardial fatty acid in mitochondria in some degree. In normal isolated working rat heart, the principal energy source is glucose. However, the major energy source is switched to catabolism of fatty acid in ischemia-reperfused isolated rat heart. This phenomenon may be related to compensative increase of fatty acid catabolism for replenishing the loss of energy during ischemia

Acute heart failure

OpenAIRE

Sénior Sánchez, Juan Manuel; Gándara Ricardo, Jairo Alfonso

2015-01-01

We describe the clinical case of a 26 year-old woman who came to Hospital Universitario San Vicente Fundación (Medellín, Colombia) with symptoms and signs of acute heart failure. She had been previously diagnosed with chronic heart failure with reduced ejection fraction without clear origin, pulmonary thromboembolism and ischemic stroke, without optimal neurohormonal modulation. She was admitted with clinical findings of fluid overload and low tissue perfusion, with inotropic support requirem...

Stress perfusion magnetic resonance imaging to detect coronary artery lesions in children.

Science.gov (United States)

Vijarnsorn, Chodchanok; Noga, Michelle; Schantz, Daryl; Pepelassis, Dion; Tham, Edythe B

2017-05-01

Stress perfusion cardiovascular magnetic resonance (CMR) is used widely in adult ischemic heart disease, but data in children is limited. We sought to evaluate feasibility, accuracy and prognostic value of stress CMR in children with suspected coronary artery disease (CAD). Stress CMR was reviewed from two pediatric centers over 5 years using a standard pharmacologic protocol. Wall motion abnormalities, perfusion deficits and late enhancement were correlated with coronary angiogram (CAG) when available, and clinical status at 1 year follow-up for major adverse cardiovascular events (MACE; coronary revascularization, non-fatal myocardial infarction and death due to CAD) was recorded. Sixty-four stress perfusion CMR studies in 48 children (10.9 ± 4.8 years) using adenosine; 59 (92%) and dipyridamole; 5 (8%), were reviewed. Indications were Kawasaki disease (39%), post arterial switch operation (12.5%), post heart transplantation (12.5%), post anomalous coronary artery repair (11%), chest pain (11%), suspected myocarditis or CAD (3%), post coronary revascularization (3%), and others (8%). Twenty-six studies were performed under sedation. Of all studies performed, 66% showed no evidence of ischemia or infarction, 28% had perfusion deficits and 6% had late gadolinium enhancement (LGE) without perfusion deficit. Compared to CAG, the positive predictive value (PPV) of stress CMR was 80% with negative predictive value (NPV) of 88%. At 1 year clinical follow-up, the PPV and NPV of stress CMR to predict MACE were 78 and 98%. Stress-perfusion CMR, in combination with LGE and wall motion-analysis is a feasible and an accurate method of diagnosing CAD in children. In difficult cases, it also helps guide clinical intervention by complementing conventional CAG with functional information.

CARE AND FEEDING OF FROGS

International Nuclear Information System (INIS)

Pan, Margaret; Chiang, Eugene

2012-01-01

'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Blériot', appear consistent with a sinusoid of period ∼4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t delay , the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t delay exceeds the frog libration period P lib , and if damping from Lindblad torques balances driving from co-orbital torques. If t delay ib , then the libration amplitude damps to zero. In the case of Blériot, the frog resonance model can reproduce the observed libration period P lib ≅ 4 yr. However, our simple feedback prescription suggests that Blériot's t delay ∼ 0.01P lib , which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

3D whole-heart myocardial tissue analysis

NARCIS (Netherlands)

van den Broek, HT; de Jong, Leon; Doevendans, Pieter A.; Chamuleau, Steven A.J.; van Slochteren, Frebus J.; Van Es, René

2017-01-01

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other biologicals that enhance angio- or vasculogenesis into the infarct border zone (IBZ), tissue perfusion is improved, and the myocardium can be protected

Substantial species differences in relation to formation and degradation of N-acyl-ethanolamine phospholipids in heart tissue

DEFF Research Database (Denmark)

Moesgaard, B.; Petersen, G.; Hansen, Harald S.

2002-01-01

beneficial effects on the heart, but in the literature there are indications of species differences in the activity of these enzymes. We have examined heart microsomes from rats, mice, guinea pigs, rabbits, frogs, cows, dogs, cats, mini pigs and human beings for activities of these two enzymes. N......-Acyl-transferase activity was very high in dogs and cats (>13 pmol/min/mg protein) whereas it was very low to barely detectable in the other species (45 pmol/min/mg protein) whereas it was 9 pmol/min/mg protein in frogs and below that in the other species. The ratio of activity between the two enzymes varied from 0.......002 to 15 in the investigated species. The activity of the two enzymes in rat hearts as opposed to rat brain did not change during development. These results indicate that there may be substantial species differences in the generation of anandamide and other NAEs as well as NAPEs in heart tissues....

Preliminary studies of pulmonary perfusion scanning in patients with pulmonary hypertension

International Nuclear Information System (INIS)

Shi Rongfang; Liu Xiujie; Wang Yanqun

1986-01-01

A comparative analysis of pulmonary perfusion scanning through cardiac catheterization of 57 patients including 32 patients with congenital heart disease, 8 patients with chronic pulmonary thromboembolism and 7 patients with primary pulmonary hypertension is reported. The lung scintigram obtained with In-113m or Tc-99m-MAA represents the distribution of pulmonary blood. It has been found that the lung scintigram was abnormal in patients of congenital heart disease with pulmonary hypertension (i. e. pulmonary artery pressure between 41-80 mmHg) and the extent of radoiactive regional defects is proportional to the level of pulmonary hypertension. The results of the analysis indicated that pulmonary perfusion scanning being a noninvasive technique would be a useful method in evaluating the level of pulmonary hypertension in patients with left to right shunt before and after surgical operation

Large intestine bacterial flora of nonhibernating and hibernating leopard frogs (Rana pipiens).

OpenAIRE

Gossling, J; Loesche, W J; Nace, G W

1982-01-01

The bacteria in the large intestines of 10 northern leopard frogs (Rana pipiens) were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10(10) bacteria per g (wet weight) of intestinal contents and about 10(9) bacteria per g (wet weight) of mucosal scraping, although the counts from the winter frogs wer...

THE MOCHE BOTANICAL FROG (La rana botánica mochica)

OpenAIRE

Donna McClelland †

2011-01-01

Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog perform...

Perfusion MR imaging of the heart with TrueFISP

International Nuclear Information System (INIS)

Schreiber, W.G.; Schmitt, M.; Kalden, P.; Mohrs, O.; Kreitner, K.F.; Thelen, M.; Horstick, G.; Gumbrich, T.; Petersen, S.; Voigtlaender, T.

2001-01-01

Objective: Development and test of a saturation-recovery TrueFISP (SR-Trufi) pulse sequence for myocardial perfusion MR imaging (MRI) using improved gradient hardware. Material and methods: Measurements were performed on a 1.5 T scanner with prototype gradients (50 mT/m, minimum rise time 300 μs). T 1 -weighted first-pass MRI of Gd-DTPA (0.025 μmol/kg) kinetics in the myocardium was performed using an SR-Trufi pulse sequence (T R /T E /α=2.6 ms/1.4 ms/55 ) with a saturation preparation of TD-30 ms before the TrueFISP readout. Measurements were performed in volunteers (n=4) and in a pig model of chronic ischemia (n=1). Results: In phantoms, the signal intensity was linear with contrast concentration up to 0.9 mmol/kg Gd-DTPA. MR images obtained with SR-Trufi had a good image quality and high spatial resolution of 2.1 mmx2.1 mm. Differences of the contrast agent's kinetics between a subendocardial perfusion deficit and neighboring myocardium were well visible on both MR images and signal-time curves derived from the region-of-interest analysis. Conclusion: SR-Trufi appears to be an interesting new technique for the assessment of myocardial microcirculation using dedicated cardiovascular MR systems. (orig.) [de

Mechanisms for altered carnitine content in hypertrophied rat hearts

International Nuclear Information System (INIS)

Reibel, D.K.; O'Rourke, B.; Foster, K.A.

1987-01-01

Carnitine levels are reduced in hypertrophied hearts of rats subjected to aortic constriction (banding) and evaluated in hypertrophied hearts of spontaneously hypertensive rats (SHR). In an attempt to determine the mechanisms for these alterations, L-[ 14 C]carnitine transport was examined in isolated perfused hearts. Total carnitine uptake was significantly reduced by ∼20% in hypertrophied hearts of banded rats at all perfusate carnitine concentrations employed. The reduction in total uptake was due to a 40% reduction in carrier-mediated carnitine uptake with no difference in uptake by diffusion. In contrast, carnitine uptake was not altered in isolated hypertrophied hearts of SHR. However, serum carnitine levels were elevated in SHR, which could result in increased myocardial carnitine uptake in vivo. The data suggest that altered carnitine content in hypertrophied hearts of aortic-banded rats is due to an alteration in the carrier-mediated carnitine transport system in the myocardium. However, altered carnitine content in hypertrophied hearts of SHR is not due to a change in the carnitine transport system per se but may rather be due to a change in serum carnitine levels

Assessment by three-dimensional power Doppler ultrasound of cerebral blood flow perfusion in fetuses with congenital heart disease.

Science.gov (United States)

Zeng, S; Zhou, J; Peng, Q; Tian, L; Xu, G; Zhao, Y; Wang, T; Zhou, Q

2015-06-01

To use three-dimensional (3D) power Doppler ultrasound to investigate cerebral blood flow perfusion in fetuses with congenital heart disease (CHD). The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) in the total intracranial volume and the main arterial territories (middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA)) were evaluated prospectively and compared in 112 fetuses with CHD and 112 normal fetuses using 3D power Doppler. Correlations between the 3D power Doppler indices and neurodevelopment scores at 12 months of age were assessed in a subset of the CHD group, and values were compared with those of controls. Compared with the controls, the VI, FI and VFI of the total intracranial volume and the three main arteries were significantly higher in fetuses with hypoplastic left heart syndrome and left-sided obstructive lesions (P power Doppler values in the ACA territory were significantly higher in fetuses with transposition of the great arteries (P power Doppler ultrasound might help to identify cases of brain vasodilatation earlier and inform parental counseling. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Intact nitric oxide production is obligatory for the sustained flow response during hypercapnic acidosis in guinea pig heart.

Science.gov (United States)

Heintz, Anke; Koch, Thea; Deussen, Andreas

2005-04-01

The mechanisms underlying hypercapnic coronary dilation remain unsettled. This study tests the hypothesis that flow dependent NO production is obligatory for the hypercapnic flow response. In isolated, constant pressure (CP) perfused guinea pig hearts a step change of arterial pCO(2) from 38.6 to 61.4 mm Hg induced a bi-phasic flow response with an early transient (maximum 60 s) and a consecutive persisting flow rise (121.6+/-6.6 (S.D.) % after 10 min). In contrast, when perfused with constant flow (CF), perfusion pressure only transiently (2 min) fell by 7.4+/-4.8 % following the step change of arterial pCO(2). In CP perfused hearts L-NAME (100 micromol/l) specifically abolished the delayed flow rise during hypercapnic acidosis (102.37+/-2.9% after 10 min), whereas the inhibitor had no effect on perfusion pressure response in CF perfused hearts. Under CP perfusion arterial hypercapnia resulted in a transient rise of coronary cGMP release (from 0.69+/-0.35 to 1.12+/-0.68 pmol/ml), which was abolished after L-NAME. Surprisingly, the K(+)ATP channel blocker glibenclamide did not have any significant effect on the hypercapnic flow response but largely blunted reactive hyperemia after a 20 s flow stop. The delayed steady state hypercapnic flow response in guinea pig heart requires intact NO production. The absence of a persisting decrease in coronary resistance under CF perfusion points to an important role of shear stress dependent NO production.

Positron emission tomography of the heart

International Nuclear Information System (INIS)

Budinger, T.F.; Yano, Y.; Moyer, B.R.; Mathis, C.A.; Ganz, E.; Huesman, R.H.; Derenzo, S.E.

1982-01-01

Positron emission tomography (PET) of the heart can measure blood perfusion, metabolism of fatty acids, metabolism of sugars, uptake of amino acids and can quantitate infarction volume. The principles which are basic to PET instrumentation and procedures for quantitative studies of the heart muscle with examples of measurements of myocardial flow and metabolism, are reviewed

Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure

Science.gov (United States)

Shojaeifard, Maryam; Ghaedian, Tahereh; Yaghoobi, Nahid; Malek, Hadi; Firoozabadi, Hasan; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amin, Ahmad; Azizian, Nasrin; Rastgou, Feridoon

2015-01-01

Background: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. Objectives: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. Patients and Methods: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. Results: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. Conclusions: Gated SPECT MPI has a good correlation with echocardiography for the measurement of left ventricular EF, EDV, and ESV in patients with severe heart failure. However, the absolute values of these functional parameters from echocardiography and gated

Peatlands and green frogs: A relationship regulated by acidity?

Science.gov (United States)

Mazerolle, M.J.

2005-01-01

The effects of site acidification on amphibian populations have been thoroughly addressed in the last decades. However, amphibians in naturally acidic environments, such as peatlands facing pressure from the peat mining industry, have received little attention. Through two field studies and an experiment, I assessed the use of bog habitats by the green frog (Rana clamitans melanota), a species sensitive to various forestry and peat mining disturbances. First, I compared the occurrence and breeding patterns of frogs in bog and upland ponds. I then evaluated frog movements between forest and bog habitats to determine whether they corresponded to breeding or postbreeding movements. Finally, I investigated, through a field experiment, the value of bogs as rehydrating areas for amphibians by offering living Sphagnum moss and two media associated with uplands (i.e., water with pH ca 6.5 and water-saturated soil) to acutely dehydrated frogs. Green frog reproduction at bog ponds was a rare event, and no net movements occurred between forest and bog habitats. However, acutely dehydrated frogs did not avoid Sphagnum. Results show that although green frogs rarely breed in bogs and do not move en masse between forest and bog habitats, they do not avoid bog substrates for rehydrating, despite their acidity. Thus, bogs offer viable summering habitat to amphibians, which highlights the value of these threatened environments in terrestrial amphibian ecology.

Effects of Scirpusin B, a polyphenol in passion fruit seeds, on the coronary circulation of the isolated perfused rat heart

Directory of Open Access Journals (Sweden)

Yutaka Matsumoto, Nozomi Gotoh, Shoko Sano, Kenkichi Sugiyama, Tatsuhiko Ito, Yohei Abe, Yumi Katano, Akira Ishihata

2014-07-01

Full Text Available Objective: Piceatannol, a polyphenol which is contained in passion fruits seed, is a derivative of resveratrol and is known to have antioxidant, anti-inflammatory and vasorelaxing activities. Passion fruits seed also contains a dimer of Piceatannol, Scirpusin B. The aim of this study was to investigate the effect of Scirpusin B on the coronary circulation of the isolated rat heart. Methods: Hearts were isolated from male Fischer 344 rats (5 – 6 months old, and perfused with modified Krebs-Henseleit solution aerated with 95% O2 and 5% CO2 (37 °C at constant pressure (75 cmH2O by Langendorff’s method. Piceatannol or Scirpusin B (10, 30 and 100 μM was injected as a bolus into the aortic cannula and coronary flow (CF was continuously measured by the electromagnetic flow meter. In some experiments, rat hearts were pretreated with L-NAME (an inhibitor of nitric oxide synthase or Diclofenac (an inhibitor of cyclooxygenase to reveal the possible involvement of nitric oxide (NO and vasodilating prostanoids in the effect of Scirpusin B. Results: Scirpusin B increased CF up to 108.2 % of the initial value, while Piceatannol did not increase CF. In addition; Scirpusin B increased CF concentration-dependently. Pretreatment with L-NAME or Diclofenac significantly attenuated the Scirpusin B-induced coronary vasodilatation. Scirpusin B did not change the heart rate either left ventricular pressure. Conclusion: This study shows that Scirpusin B could increase CF via production of NO and vasodilating prostanoids.

Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

Science.gov (United States)

Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

2015-09-01

In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

Courtship in Frogs

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 12. Courtship in Frogs Role of Acoustic Communication in Amphibian Courtship Behaviour. Debjani Roy. General Article Volume 1 Issue 12 December 1996 pp 39-48 ...

Polydeoxyribonucleotides and nitric oxide release from guinea-pig hearts during ischaemia and reperfusion.

Science.gov (United States)

Masini, E.; Lupini, M.; Mugnai, L.; Raspanti, S.; Mannaioni, P. F.

1995-01-01

1. Two polydeoxyribonucleotides, produced by the controlled hydrolysis of DNA of mammalian lung (defibrotide and its lower molecular weight fraction, P.O. 085 DV), were studied for their ability to modify the release of nitrite and the coronary flow in perfusates collected from isolated, normally perfused hearts of guinea-pigs and from hearts subjected to regional ischaemia and reperfusion. 2. In guinea-pig normally perfused hearts, both defibrotide (DFT) and its fraction, P.O. 085 DV, increase the amount of nitrite appearing in perfusates in a concentration-dependent fashion. At the highest concentration studied (10(-6) M), P.O. 085 DV was more effective than DFT. A concomitant increase in the coronary flow was observed. 3. The increase in nitrite in perfusates and the increase in coronary flow induced by both DFT and P.O. 085 DV were significantly reduced by NG-monomethyl-L-arginine (L-NMMA, 10(-4) M), an inhibitor of nitric oxide synthase (NOS). 4. The endothelium-dependent vasodilator, acetylcholine (ACh), enhances the formation of nitrite and the coronary flow. Both the increase in coronary flow and in the formation of nitrite were significantly reduced by L-NMMA (10(-4) M). 5. In guinea-pig hearts subjected to ischaemia and reperfusion, the effect of both compounds in increasing the amount of nitrite in perfusates was more evident and more pronounced with P.O. 085 DV. 6. Reperfusion-induced arrhythmias were significantly reduced by both compounds to the extent of complete protection afforded by compound P.O. 085 DV. 7. The cardioprotective and antiarrhythmic effects of DFT and P.O. 085 DV are discussed. PMID:7582482

Do thallium myocardial perfusion scan abnormalities predict survival in sarcoid patients without cardiac symptoms

International Nuclear Information System (INIS)

Kinney, E.L.; Caldwell, J.W.

1990-01-01

Whereas the total mortality rate for sarcoidosis is 0.2 per 100,000, the prognosis, when the heart is involved, is very much worse. The authors used the difference in mortality rate to infer whether thallium 201 myocardial perfusion scan abnormalities correspond to myocardial sarcoid by making the simplifying assumption that if they do, then patients with abnormal scans will be found to have a death rate similar to patients with sarcoid heart disease. The authors therefore analyzed complete survival data on 52 sarcoid patients without cardiac symptoms an average of eighty-nine months after they had been scanned as part of a protocol. By use of survival analysis (the Cox proportional hazards model), the only variable that was significantly associated with survival was age. The patients' scan pattern, treatment status, gender, and race were not significantly related to survival. The authors conclude that thallium myocardial perfusion scans cannot reliably be used to diagnose sarcoid heart disease in sarcoid patients without cardiac symptoms

Simultaneous detection of landmarks and key-frame in cardiac perfusion MRI using a joint spatial-temporal context model

Science.gov (United States)

Lu, Xiaoguang; Xue, Hui; Jolly, Marie-Pierre; Guetter, Christoph; Kellman, Peter; Hsu, Li-Yueh; Arai, Andrew; Zuehlsdorff, Sven; Littmann, Arne; Georgescu, Bogdan; Guehring, Jens

2011-03-01

Cardiac perfusion magnetic resonance imaging (MRI) has proven clinical significance in diagnosis of heart diseases. However, analysis of perfusion data is time-consuming, where automatic detection of anatomic landmarks and key-frames from perfusion MR sequences is helpful for anchoring structures and functional analysis of the heart, leading toward fully automated perfusion analysis. Learning-based object detection methods have demonstrated their capabilities to handle large variations of the object by exploring a local region, i.e., context. Conventional 2D approaches take into account spatial context only. Temporal signals in perfusion data present a strong cue for anchoring. We propose a joint context model to encode both spatial and temporal evidence. In addition, our spatial context is constructed not only based on the landmark of interest, but also the landmarks that are correlated in the neighboring anatomies. A discriminative model is learned through a probabilistic boosting tree. A marginal space learning strategy is applied to efficiently learn and search in a high dimensional parameter space. A fully automatic system is developed to simultaneously detect anatomic landmarks and key frames in both RV and LV from perfusion sequences. The proposed approach was evaluated on a database of 373 cardiac perfusion MRI sequences from 77 patients. Experimental results of a 4-fold cross validation show superior landmark detection accuracies of the proposed joint spatial-temporal approach to the 2D approach that is based on spatial context only. The key-frame identification results are promising.

Electrophysiologic effects of the IK1 inhibitor PA-6 are modulated by extracellular potassium in isolated guinea pig hearts

DEFF Research Database (Denmark)

Hoeker, Gregory S; Skarsfeldt, Mark A; Jespersen, Thomas

2017-01-01

in Langendorff-perfused guinea pig hearts. PA-6 (200 nm) or vehicle was perfused into ex-vivo guinea pig hearts for 60 min. Hearts were optically mapped with di-4-ANEPPS to quantify CV and APD at 90% repolarization (APD90). Ventricular APD90was significantly prolonged in hearts treated with PA-6 (115 ± 2...... APD90to a lesser degree, but profoundly increased CV Thus, in intact guinea pig hearts, the electrophysiologic effects of the IK1inhibitor, PA-6, are [K+]o-dependent....

Prognostic value of myocardial perfusion SPECT images in combination with the maximal heart rate at exercise testing in Japanese patients with suspected ischemic heart disease. A sub-analysis of J-ACCESS

International Nuclear Information System (INIS)

Ueshima, Kenji; Usami, Satoru; Yasuno, Shinji; Nakao, Kazuwa; Yamashina, Akira; Nishiyama, Osamu; Yamazaki, Takuya; Nishimura, Tsunehiko

2009-01-01

We assessed whether a combination of summed stress scores (SSS) using exercise myocardial perfusion single photon emission computed tomography (SPECT) (Ex-SPECT) and maximal heart rate accurately predicts cardiac events through a sub-analysis of J-ACCESS (Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT) which was conducted to evaluate the prognosis of Japanese patients with suspected ischemic heart disease. In J-ACCESS, 2,373 patients with suspected coronary artery disease not receiving beta-blocker treatment underwent Ex-SPECT. These patients were categorized into the following four groups: Group A [achieved target heart rate (THR) and SSS<4: n=631], B (did not achieve THR and SSS<4: n=612), C (achieved THR and SSS≥4: n=570), and D (did not achieve THR and SSS≥4: n=560). We evaluated the incidence rate of cardiac events including cardiac death, myocardial infarction, and heart failure requiring hospital admission during a 3-year period. In Group A, B, C, and D, 9 of 631 (1.4%), 15 of 612 (2.4%), 23 of 570 (4.0%) and 30 of 560 (5.4%) patients experienced cardiac events, respectively. Although the hazard ratio of the SSS≥4 was 2.45 (p<0.001) and that of the attained THR was 0.69 (p=0.10) in the multiple Cox regression analysis, Kaplan-Meier curves showed that the cardiac events rate was lower in the order of A, B, C, and D (p<0.001). The combination of SSS using Ex-SPECT and the maximal heart rate is a useful predictor of cardiac events in patients with suspected coronary artery disease. (author)

Positron emission tomography of the heart

International Nuclear Information System (INIS)

Budinger, T.F.; Yano, Y.; Mathis, C.A.; Moyer, B.R.; Huesman, R.H.; Derenzo, S.E.

1983-01-01

Positron emission tomography (PET) offers the opportunity to noninvasively measure heart muscle blood perfusion, oxygen utilization, metabolism of fatty acids, sugars and amino acids. This paper reviews physiological principles which are basic to PET instrumentation for imaging the heart and gives examples of the application of positron emission tomography for measuring myocardial flow and metabolism. 33 references, 11 figures, 1 table

Biosynthesis of plasmenylcholine in guinea pig heart

International Nuclear Information System (INIS)

Wientzek, M.; Choy, P.C.

1986-01-01

In some mammalian hearts, up to 40% of the choline phosphoglyceride (CPG) exists as plasmenylcholine (1-alkenyl-2-acyl-glycero-3-phosphocholine). Although the majority of diacylphosphatidylcholine (PC) in mammalian hearts is synthesized from choline via the CDP-choline pathway, the formation of plasmenylcholine from choline was not known. In this study, they investigated the biosynthesis of plasmenyl-choline in the isolated guinea pig heart by perfusion with [ 3 H]choline. Labelled choline containing metabolites and labelled plasmenylcholine were isolated and determined at different perfusion time points. Significant amounts of labelling were found only in choline, phosphocholine, CDP-choline, plasmenyl-choline and PC. In addition, a precursor-product relationship was observed between the labelling of CDP-choline and plasmenylcholine. Such a relationship was not observed between choline and plasmenylcholine. Hence, they postulate that the incorporation of choline into plasmenylcholine is via the CDP-choline pathway and not via base exchange. The ability to condense 1-alkenyl-2-acyl-glycerol with CDP-choline was also demonstrated in vitro with guinea pig heart microsomes

Bull's-eye map of myocardial perfusion MR imaging. Comparison with SPECT

International Nuclear Information System (INIS)

Nomura, Yukihiro; Nanjo, Shuji; Yamazaki, Junichi; Yoshikawa, Kohki; Inoue, Yusuke

2003-01-01

When diagnosing heart disease, chest roentgenograms, ultrasonography, single-photon emission computed tomography (SPECT), and coronary arteriography are usually performed. Magnetic resonance (MR) imaging is not widely used for evaluating heart disease. Recent technological progress has allowed high quality images of the heart to be reliably obtained. A routine MR study taking about 30-40 minutes can provide a large amount of diagnostic information, such as cardiac structure, function, perfusion, and myocardial viability. The analysis software that can offer Bull's-eye maps from myocardial perfusion images has recently become commercially available. In this study, the characteristics of Bull's-eye mapping of MR imaging is compared with that of Bull's-eye mapping of SPECT using the same heart phantom. The difference in the image quality of the Bull's-eye maps was evaluated among the receiver coils of MR imaging. On Bull's-eye maps from both MR imaging and SPECT, decreased signal intensity was noted in the posterolateral wall. The degree of decrease in the signal of the MR imaging was more prominent than of SPECT. The decrease was severe for the general-purpose receive-only flexible (GPFLEX) coil, moderate for the cardiac and TORSO coil, and slight for the body coil. In the selection of a coil, it is necessary to take into consideration the trade-off between the distribution of signal intensity and the signal-to-noise ratio (SNR). (author)

Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia commercialized in France

Directory of Open Access Journals (Sweden)

Annemarie Ohler

2017-02-01

Full Text Available Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

Ovarian hyperstimulation syndrome in gonadotropin-treated laboratory South African clawed frogs (Xenopus laevis).

Science.gov (United States)

Green, Sherril L; Parker, John; Davis, Corrine; Bouley, Donna M

2007-05-01

Ovarian hyperstimulation syndrome (OHS) is a rare but sometimes fatal iatrogenic complication of ovarian stimulation associated with the administration of exogenous gonadotropins to women undergoing treatment for infertility. Laboratory Xenopus spp are commonly treated with human chorionic gonadotropin (hCG) to stimulate ovulation and optimize the number of oocytes harvested for use in biomedical research. Here we report cases of OHS in 2 gonadotropin-treated laboratory Xenopus laevis. After receiving hCG, the frogs developed severe subcutaneous accumulation of fluid, coelomic distention, and whole-body edema and were unable to dive, although they continued to eat and swim. At postmortem examination, extensive subcutaneous edema was present; ascites and massive numbers of free-floating eggs were found in the coelomic cavity and in aberrant locations: around the heart-sac and adhered to the liver capsule. Whole-body edema, gross enlargement of the ovaries, ascites, and abdominal distention are findings comparable to those observed in women with OHS. The pathophysiology of OHS is thought to be related to hormonally induced disturbances of vasoactive mediators, one of which may be vascular endothelial growth factor secreted by theca and granulosa cells. We know of no other report describing OHSlike symptoms in gonadotropin-treated frogs, and the cases described here are 2 of the 3 we have observed at our respective institutions over the last 6 y. According to these results, OHS appears to be rare in gonadotropin-treated laboratory Xenopus. However, the condition should be included in the differential diagnosis for the bloated frog.

Effect of forced-air heaters on perfusion and temperature distribution during and after open-heart surgery

NARCIS (Netherlands)

Severens, Natascha M. W.; van Marken Lichtenbelt, Wouter D.; van Leeuwen, Gerard M. J.; Frijns, Arjan J. H.; van Steenhoven, Anton A.; de Mol, Bas A. J. M.; van Wezel, Harry B.; Veldman, Dirk J.

2007-01-01

OBJECTIVES: After cardiopulmonary bypass, patients often show redistribution hypothermia, also called afterdrop. Forced-air blankets help to reduce afterdrop. This study explores the effect of forced-air blankets on temperature distribution and peripheral perfusion. The blood perfusion data is used

Radiation-induced damage of the Wistar Rat heart

International Nuclear Information System (INIS)

Cilliers, G.D.; Lochner, A.

1993-01-01

A time sequence study was performed on Wistar rats to investigate the early effects of radiation on the mechanical function and energy metabolism of the heart. Two series of rats were exposed to 20 Gy electron irradiation to a field including the heart and approximately a third of the lungs. The hearts were excised at varying time intervals (8-180 days) post irradiation. In one series of hearts the mechanical function was measured using the isolated perfused working rat heart model. At the end of the perfusion the hearts were freeze-clamped for analysis of the high energy phosphate contents (ATP, ADP, AMP and creatine phosphate). In the second series, mitochondria were isolated and the oxidative phosphorylation function measured polarographically (substrate: glutamate). Maximal depression of mechanical function was observed at 60 days post irradiation. Thereafter the work performance of these hearts improved significantly, almost reaching control levels after 180 days. The mitochondrial oxidative phosphorylation function (as measured on the total mitochondrial population) was significantly depressed 30-120 days post irradiation. As in the case of the mechanical changes, the depression was transient and after 180 days post irradiation, values similar to those of controls were obtained. Myocardial high energy phosphates remained unaltered throughout the experiment. (author)

Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

DEFF Research Database (Denmark)

Seifert, Thomas; Fisher, James P; Young, Colin N

2010-01-01

Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebral......(mean) during ergometer cycling (n = 8). Separate, randomized and counterbalanced trials were performed in control (no drug) conditions and following muscarinic cholinergic receptor blockade by glycopyrrolate. Glycopyrrolate increased resting heart rate from approximately 60 to approximately 110 beats min(-1...... abolished by glycopyrrolate (P important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen....

Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria)

OpenAIRE

Strong, Becky; Halsall, Crispin James; Ferenčík, Martin; Jones, Kevin Christopher; Shore, Richard Francis; Martin, Francis Luke

2016-01-01

Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpol...

IgE antibodies of fish allergic patients cross-react with frog parvalbumin.

Science.gov (United States)

Hilger, C; Thill, L; Grigioni, F; Lehners, C; Falagiani, P; Ferrara, A; Romano, C; Stevens, W; Hentges, F

2004-06-01

The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross-recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin alpha has been found to be responsible for a case of IgE-mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross-react with frog parvalbumin and to appreciate its clinical relevance. The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE-immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin alpha and beta from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca(2+) depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross-reactive pattern. Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with alpha parvalbumin and 11 of 12 reacted with beta parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin. Cod parvalbumin, a major cross-reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross-reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross-reactive allergens.

The value of gated myocardial perfusion imaging for the evaluation of early treatment effectiveness of ischemic heart disease using Ad-HGF myocardial injection

International Nuclear Information System (INIS)

Feng Jianlin; Cheng Xu; Li Jianhua; Xu Zhaoqiang; Li Dianfu; Yuan Biao; Zhang Yourong; Cao Kejiang; Huang Jun

2008-01-01

Objective: Hepatocyte growth factor (HGF) has multipotent actions mediated by c- Mesenchymal epithelial transition factor (Met) receptor. Preclinical studies in animal models of myocardial ischemia demonstrated that treatment with HGF could benefit myocardial perfusion, cardiac remodeling, angiogenesis and myocardial function. This study used gated 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging (G-MPI) to assess the early treatment effectiveness of adenovirus HGF (Ad-HGF) directly administered in ischemic heart disease (IHD) patients. Methods: Eighteen patients with IHD were divided into 3 groups receiving low dose [5 x 10 8 plaque forming unit (PFU)/site], medium (1.5 x 10 9 PFU/site) and high dose (5 x l0 9 PFU/site) of Ad-HGF. And the Ad-HGF was injected at 10 sites in each patient. Rest G-MPI was performed before and after treatment for myocardial perfusion and left ventricular function measurement. Stata 7.0 was used to analyse the data. Results: (1) After Ad-HGF, myocardial perfusion was improved in 3/6, 5/6 and 6/6 patients in low, medium and high dosage groups. The dosage of AD-HGF was closely correlated with the improvement of myocardial perfusion (χ 2 =4.34, P<0.05). (2) Left ventricular ejection fraction (LVEF) was significantly increased [(50.1 ± 6.4)% vs (58.7 ± 5.6)%, t=6.1, P<0.01], end-diastolic volume [EDV, (137.7 ± 33.2) ml vs (123.7 ± 32.7) ml] and end-systolic volume [ESV, (70.2 ± 22.4) ml vs (51.9 ± 14.9) ml] were significantly reduced. (3) The LVEFs were increased in all groups, and the LVEF improvement in the high dosage group [(8.6 ± 5.9)%] was significantly greater than the other two groups [(4.3 ± l.2)%, (6.8 ± 5.7)%]. The difference of post-treatment improvement on LVEF between the low and medium dosage groups was not significant. The dosage of Ad-HGF was closely correlated with the improvement of LVEF (r=0.67, P< 0.01). Conclusion: G-MPI is a reliable method for evaluating the early effectiveness of

SEA0400 fails to alter the magnitude of intracellular Ca2+ transients and contractions in Langendorff-perfused guinea pig heart.

Science.gov (United States)

Szentandrássy, Norbert; Birinyi, Péter; Szigeti, Gyula; Farkas, Attila; Magyar, János; Tóth, András; Csernoch, László; Varró, András; Nánási, Péter P

2008-07-01

SEA0400 is a recently developed inhibitor of the Na+/Ca2+ exchanger (NCX) shown to suppress both forward and reverse mode operation of NCX. Present experiments were designed to study the effect of partial blockade of NCX on Ca handling and contractility in Langendorff-perfused guinea pig hearts loaded with the fluorescent Ca-sensitive dye fura-2. Left ventricular pressure and intracellular calcium concentration ([Ca2+]i) were synchronously recorded before and after cumulative superfusion with 0.3 and 1 muM SEA0400. SEA0400 caused no significant change in the systolic and diastolic values of left ventricular pressure and [Ca2+]i. Accordingly, pulse pressure and amplitude of the [Ca2+]i transient also remained unchanged in the presence of SEA0400. SEA0400 had no influence either on the time required to reach peak values of pressure and [Ca2+)]i or on half relaxation time. On the other hand, both 0.3 and 1 microM SEA0400 significantly increased the decay time constant of [Ca2+]i transients, obtained by fitting its descending limb between 30% and 90% of relaxation, from 127 +/- 7 to 165 +/- 7 and 177 +/- 14 ms, respectively (P hearts, rat hearts responded to SEA0400 treatment with increased [Ca2+]i transients and contractility. These interspecies differences observed in the effect of SEA0400 can be explained by the known differences in calcium handling between the two species.

Local experience on radionuclide myocardial imaging in the Philippines at the Philippine Heart Center for Asia

International Nuclear Information System (INIS)

Villacorta, E.V.

1977-01-01

The Nuclear Medicine Department of the Philippine Heart Center has introduced the detection of coronary heart disease through myocardiac perfusion imaging. The cardiovascular procedures are availed of free-of-charge to registered PHCA patients excepting for the costly TI-201 imaging. In summary, coronary perfusion in imaging should be an integral part of coronary arteriography. Barring the expensive cost of TI-120, myocardial perfusion imaging is ideal for detection of coronary heart disease. Experience shows better sensitivity of TI-201 than exercise ECG for detection of ischemia. Another non-invasive procedure for the detection of acute infarction is the radionuclide imaging using a bone radiopharmaceutical Tc99m prophosphate. In conclusion, acute infarct imaging is a valuable adjunct to ECG and enzyme studies. (RTD)

Evaluation of myocardial involvement in Duchenne's progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

International Nuclear Information System (INIS)

Kawai, Naoki; Sotobata, Iwao; Okada, Mitsuhiro

1985-01-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. A qualitative analysis was performed from five projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in the LV posterolateral or posterior wall (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle involvements or thoracic deformities assessed by transmission computed tomography. Extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. Progression of the myocardial scintigraphic abnormalities were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies over 2 to 3 years. It was concluded that thallium myocardial perfusion imaging is a useful clinical technique to assess myocardial involvement in Duchenne's progressive muscular dystrophy. (author)

Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

Science.gov (United States)

McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

2016-06-01

Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey.

Stabilization of mitochondrial membrane potential prevents doxorubicin-induced cardiotoxicity in isolated rat heart

International Nuclear Information System (INIS)

Montaigne, David; Marechal, Xavier; Baccouch, Riadh; Modine, Thomas; Preau, Sebastien; Zannis, Konstantinos; Marchetti, Philippe; Lancel, Steve; Neviere, Remi

2010-01-01

The present study was undertaken to examine the effects of doxorubicin on left ventricular function and cellular energy state in intact isolated hearts, and, to test whether inhibition of mitochondrial membrane potential dissipation would prevent doxorubicin-induced mitochondrial and myocardial dysfunction. Myocardial contractile performance and mitochondrial respiration were evaluated by left ventricular tension and its first derivatives and cardiac fiber respirometry, respectively. NADH levels, mitochondrial membrane potential and glucose uptake were monitored non-invasively via epicardial imaging of the left ventricular wall of Langendorff-perfused rat hearts. Heart performance was reduced in a time-dependent manner in isolated rat hearts perfused with Krebs-Henseleit solution containing 1 μM doxorubicin. Compared with controls, doxorubicin induced acute myocardial dysfunction (dF/dt max of 105 ± 8 mN/s in control hearts vs. 49 ± 7 mN/s in doxorubicin-treated hearts; *p < 0.05). In cardiac fibers prepared from perfused hearts, doxorubicin induced depression of mitochondrial respiration (respiratory control ratio of 4.0 ± 0.2 in control hearts vs. 2.2 ± 0.2 in doxorubicin-treated hearts; *p < 0.05) and cytochrome c oxidase kinetic activity (24 ± 1 μM cytochrome c/min/mg in control hearts vs. 14 ± 3 μM cytochrome c/min/mg in doxorubicin-treated hearts; *p < 0.05). Acute cardiotoxicity induced by doxorubicin was accompanied by NADH redox state, mitochondrial membrane potential, and glucose uptake reduction. Inhibition of mitochondrial permeability transition pore opening by cyclosporine A largely prevented mitochondrial membrane potential dissipation, cardiac energy state and dysfunction. These results suggest that in intact hearts an impairment of mitochondrial metabolism is involved in the development of doxorubicin cardiotoxicity.

Frogs Call at a Higher Pitch in Traffic Noise

Directory of Open Access Journals (Sweden)

Kirsten M. Parris

2009-06-01

Full Text Available Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call at a higher pitch or frequency in urban noise, decreasing acoustic interference from low-frequency noise. Using Bayesian linear regression, we investigated the effect of traffic noise on the pitch of advertisement calls in two species of frogs, the southern brown tree frog (Litoria ewingii and the common eastern froglet (Crinia signifera. We found evidence that L. ewingii calls at a higher pitch in traffic noise, with an average increase in dominant frequency of 4.1 Hz/dB of traffic noise, and a total effect size of 123 Hz. This frequency shift is smaller than that observed in birds, but is still large enough to be detected by conspecific frogs and confer a significant benefit to the caller. Mathematical modelling predicted a 24% increase in the active distance of a L. ewingii call in traffic noise with a frequency shift of this size. Crinia signifera may also call at a higher pitch in traffic noise, but more data are required to be confident of this effect. Because frog calls are innate rather than learned, the frequency shift demonstrated by L. ewingii may represent an evolutionary adaptation to noisy conditions. The phenomenon of frogs calling at a higher pitch in traffic noise could therefore constitute an intriguing trade-off between audibility and attractiveness to potential mates.

Elastic modulus of tree frog adhesive toe pads.

Science.gov (United States)

Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

2011-10-01

Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

Panamanian frog species host unique skin bacterial communities

Directory of Open Access Journals (Sweden)

Lisa K. Belden

2015-10-01

Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

OpenAIRE

Edward C. Netherlands; Courtney A. Cook; Donnavan J.D. Kruger; Louis H. du Preez; Nico J. Smit

2015-01-01

Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracell...

A capillary-based perfusion phantom for simulation of brain perfusion for MRI; Ein kapillarbasiertes Phantom zur Simulation der Gehirnperfusion mit der Magnet-Resonanz-Tomografie

Energy Technology Data Exchange (ETDEWEB)

Maciak, A.; Kronfeld, A.; Mueller-Forell, W. [Universitaetsklinikum Mainz (Germany). Inst. fuer Neuroradiologie; Wille, C. [Fachhochschule Bingen (Germany). Inst. fuer Informatik; Kempski, O. [Universitaetsklinikum Mainz (Germany). Inst. fuer Neurochirurgische Pathophysiologie; Stoeter, P. [CEDIMAT, Santo Domingo (Dominican Republic). Inst. of Neuroradiology

2010-10-15

Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

Aid in the detection of myocardial perfusion abnormality utilizing SPECT atlas and images registration: preliminary results

International Nuclear Information System (INIS)

Padua, Rodrigo Donizete Santana de; Oliveira, Lucas Ferrari de; Marques, Paulo Mazzoncini de Azevedo; Groote, Jean-Jacques Georges Soares de; Castro, Adelson Antonio de; Ana, Lauro Wichert; Simoes, Marcus Vinicius

2008-01-01

To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observe. The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended. (author)

Aid in the detection of myocardial perfusion abnormality utilizing SPECT atlas and images registration: preliminary results

Energy Technology Data Exchange (ETDEWEB)

Padua, Rodrigo Donizete Santana de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Div. de Cardiologia]. E-mail: rodrigo_dsp@hcrp.fmrp.usp.br; Oliveira, Lucas Ferrari de [Universidade Federal de Pelotas (UFPel), RS (Brazil). Inst. de Fisica e Matematica. Dept. de Tecnologia da Informacao; Marques, Paulo Mazzoncini de Azevedo [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Groote, Jean-Jacques Georges Soares de [Instituto de Ensino Superior COC, Ribeirao Preto, SP (Brazil). Lab. of Artifical Intelligence and Applications; Castro, Adelson Antonio de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina; Ana, Lauro Wichert [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Simoes, Marcus Vinicius [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina. Divisao de Cardiologia

2008-11-15

To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observe. The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended. (author)

Hepatic perfusion during hepatic artery infusion chemotherapy: Evaluation with perfusion CT and perfusion scintigraphy

International Nuclear Information System (INIS)

Miller, D.L.; Carrasquillo, J.A.; Lutz, R.J.; Chang, A.E.

1989-01-01

The standard method for the evaluation of hepatic perfusion during hepatic artery infusion (HAI) chemotherapy is planar hepatic artery perfusion scintigraphy (HAPS). Planar HAPS was performed with 2 mCi of [99mTc] macroaggregated albumin infused at 1 ml/min and compared with single photon emission CT (SPECT) HAPS and with a new study, CT performed during the slow injection of contrast material through the HAI catheter (HAI-CT). Thirteen patients underwent 16 HAI-CT studies, 14 planar HAPS studies, and 9 SPECT HAPS studies. In 13 of 14 studies (93%) HAI-CT and planar HAPS were in complete agreement as to the perfusion pattern of intrahepatic metastases and normal liver. In nine studies where all modalities were performed, the findings identified by HAI-CT and planar HAPS agreed in all cases, whereas the results of two SPECT scans disagreed with the other studies. With respect to perfusion of individual metastases, 14 of 14 HAI-CT studies, 12 of 13 planar HAPS studies, and 9 of 9 SPECT HAPS studies correctly demonstrated the perfusion status of individual lesions as indicated by the pattern of changes in tumor size determined on CT obtained before and after the perfusion studies. Hepatic artery infusion CT was superior for delineation of individual metastases, particularly small lesions, and for the evaluation of nonperfused portions of the liver. Planar HAPS detected extrahepatic perfusion in four patients, and this was not detected by HAI-CT. We conclude that HAI-CT and scintigraphy are complementary techniques. Hepatic artery infusion CT has advantages for the evaluation of intrahepatic perfusion, and planar HAPS is superior to HAI-CT for the detection of extrahepatic perfusion

COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

Science.gov (United States)

The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

Estimation of pulmonary hypertension of congenital heart diseases in children by lung perfusion scintigraphy

International Nuclear Information System (INIS)

Zheng Jinghao; Zhang Shantong; Zeng Jiye; Jia Hongli; Ji Zhiying; Chen Siyi

1993-01-01

The authors report that changes in the distribution of pulmonary perfusion caused by gravitation effect, namely, changes in the total count ratios of the right against the left lung between right and left lateral decubitus positions (rt/lt) could estimate pulmonary hypertension using lung perfusion scintigraphy with 99m Tc-labelled macroaggregated albumin. The results showed: rt/lt was inversely related to mean pulmonary arterial pressure. It is concluded that the method is simple, safe, reproducible, unaffected by cardiac structural abnormality and valuable as a noninvasive approach for the estimation of pulmonary hypertension

Tourism and the Conservation of Critically Endangered Frogs

Science.gov (United States)

Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

2012-01-01

Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia) commercialized in France

OpenAIRE

Ohler, Annemarie; Nicolas, Violaine

2017-01-01

International audience; Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya ca...

New in vitro model for proarrhythmia safety screening: IKs inhibition potentiates the QTc prolonging effect of IKr inhibitors in isolated guinea pig hearts.

Science.gov (United States)

Kui, Péter; Orosz, Szabolcs; Takács, Hedvig; Sarusi, Annamária; Csík, Norbert; Rárosi, Ferenc; Csekő, Csongor; Varró, András; Papp, Julius Gy; Forster, Tamás; Farkas, Attila S; Farkas, András

2016-01-01

Preclinical in vivo QT measurement as a proarrhythmia essay is expensive and not reliable enough. The aim of the present study was to develop a sensitive, cost-effective, Langendorff perfused guinea pig heart model for proarrhythmia safety screening. Low concentrations of dofetilide and cisapride (inhibitors of the rapid delayed rectifier potassium current, IKr) were tested alone and co-perfused with HMR-1556 (inhibitor of the slow delayed rectifier potassium current, IKs) in Langendorff perfused guinea pig hearts. The electrocardiographic rate corrected QT (QTc) interval, the Tpeak-Tend interval and the beat-to-beat variability and instability (BVI) of the QT interval were determined in sinus rhythm. Dofetilide and HMR-1556 alone or co-perfused, prolonged the QTc interval by 20±2%, 10±1% and 55±10%, respectively. Similarly, cisapride and HMR-1556 alone or co-perfused, prolonged the QTc interval by 11±3%, 11±4% and 38±6%, respectively. Catecholamine-induced fast heart rate abolished the QTc prolonging effects of the IKr inhibitors, but augmented the QTc prolongation during IKs inhibition. None of the drug perfusions increased significantly the Tpeak-Tend interval and the sinus BVI of the QT interval. IKs inhibition increased the QTc prolonging effect of IKr inhibitors in a super-additive (synergistic) manner, and the QTc interval was superior to other proarrhythmia biomarkers measured in sinus rhythm in isolated guinea pig hearts. The effect of catecholamines on the QTc facilitated differentiation between IKr and IKs inhibitors. Thus, QTc measurement in Langendorff perfused guinea pig hearts with pharmacologically attenuated repolarization reserve and periodic catecholamine perfusion seems to be suitable for preclinical proarrhythmia screening. Copyright © 2016 Elsevier Inc. All rights reserved.

NMR-tomography of the heart

International Nuclear Information System (INIS)

Weikl, A.; Bachmann, K.

1987-01-01

The NMR-tomography as a non-invasive imaging process is examined regarding to the value to answer clinical issues. This method allows an evaluation of qualitative, quantitative, morphological and functional parameters. The diagnostic use on the heart shows early myocardial changes, thrombosis, changes in the dynamics of the left ventricle (EDV, ESV, EF), the quantitative wall movement and the blood flow in a shunt defect. The placed value of echocardiography, myocardial scintigraphy and coronary angiography in the diagnosis of acquired valvular heart disease, myocardial perfusion and coronary heart disease is not lowered by the above mentioned method. (orig.) [de

NMR-tomography of the heart

Energy Technology Data Exchange (ETDEWEB)

Weikl, A.; Bachmann, K.

1987-04-03

The NMR-tomography as a non-invasive imaging process is examined regarding to the value to answer clinical issues. This method allows an evaluation of qualitative, quantitative, morphological and functional parameters. The diagnostic use on the heart shows early myocardial changes, thrombosis, changes in the dynamics of the left ventricle (EDV, ESV, EF), the quantitative wall movement and the blood flow in a shunt defect. The placed value of echocardiography, myocardial scintigraphy and coronary angiography in the diagnosis of acquired valvular heart disease, myocardial perfusion and coronary heart disease is not lowered by the above mentioned method.

Heart and brain interaction in patients with heart failure: overview and proposal for a taxonomy. A position paper from the Study Group on Heart and Brain Interaction of the Heart Failure Association.

Science.gov (United States)

Doehner, Wolfram; Ural, Dilek; Haeusler, Karl Georg; Čelutkienė, Jelena; Bestetti, Reinaldo; Cavusoglu, Yuksel; Peña-Duque, Marco A; Glavas, Duska; Iacoviello, Massimo; Laufs, Ulrich; Alvear, Ricardo Marmol; Mbakwem, Amam; Piepoli, Massimo F; Rosen, Stuart D; Tsivgoulis, Georgios; Vitale, Cristiana; Yilmaz, M Birhan; Anker, Stefan D; Filippatos, Gerasimos; Seferovic, Petar; Coats, Andrew J S; Ruschitzka, Frank

2018-02-01

Heart failure (HF) is a complex clinical syndrome with multiple interactions between the failing myocardium and cerebral (dys-)functions. Bi-directional feedback interactions between the heart and the brain are inherent in the pathophysiology of HF: (i) the impaired cardiac function affects cerebral structure and functional capacity, and (ii) neuronal signals impact on the cardiovascular continuum. These interactions contribute to the symptomatic presentation of HF patients and affect many co-morbidities of HF. Moreover, neuro-cardiac feedback signals significantly promote aggravation and further progression of HF and are causal in the poor prognosis of HF. The diversity and complexity of heart and brain interactions make it difficult to develop a comprehensive overview. In this paper a systematic approach is proposed to develop a comprehensive atlas of related conditions, signals and disease mechanisms of the interactions between the heart and the brain in HF. The proposed taxonomy is based on pathophysiological principles. Impaired perfusion of the brain may represent one major category, with acute (cardio-embolic) or chronic (haemodynamic failure) low perfusion being sub-categories with mostly different consequences (i.e. ischaemic stroke or cognitive impairment, respectively). Further categories include impairment of higher cortical function (mood, cognition), of brain stem function (sympathetic over-activation, neuro-cardiac reflexes). Treatment-related interactions could be categorized as medical, interventional and device-related interactions. Also interactions due to specific diseases are categorized. A methodical approach to categorize the interdependency of heart and brain may help to integrate individual research areas into an overall picture. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.

Neuromuscular control of prey capture in frogs.

OpenAIRE

Nishikawa, K C

1999-01-01

While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control. In this paper, I address the following three questions. (1) How do frog tongues differ biomechanically? (2) What anatomical and physiological differences are responsible? (3) How is biomechanics related to mechanisms of neuromuscular cont...

Correlation of the myocardial perfusion corrected by attenuation with the coronariography. Preliminary results

International Nuclear Information System (INIS)

Garcia C, S.E.; Garcia O, R.

2005-01-01

The attenuation that suffers the radiation in the soft tissues of the hinders the appropriate interpretation of the myocardial perfusion studies, for what have been implemented attenuation correction systems to reduce the attenuation for soft tissues and to provide myocardial perfusion images more accurate in the diagnosis of coronary illness. The objective was to evaluate the utility of an attenuation correction system (with source of Gadolinium 153) to minimize the devices that look like true defects of myocardial perfusion, caused by soft tissues (mammary tissue, thoracic wall, abdomen, left hemi diaphragm), and to compare those interpretations of the studies with the interpretations of the corresponding coronariographies. The method consists of 95 electronic files which were revised with the concept of heart catheterization, being identified 20 patients from the masculine sex to those that underwent coronariography among May 1999 and December 2002, and that they had study of myocardial perfusion in a maximum period of 3 months foresaw to the invasive procedure. (Author)

Metabolic fate of rat heart endothelial lipoprotein lipase

International Nuclear Information System (INIS)

Chajek-Shaul, T.; Bengtsson-Olivecrona, G.; Peterson, J.; Olivecrona, T.

1988-01-01

When isolated rat hearts were perfused with medium containing 125I-labeled bovine lipoprotein lipase (LPL), they bound both lipase activity and radioactivity. More than 80% of the bound lipase could be rapidly released by heparin. Low concentrations of bovine LPL displaced 50-60% of the endogeneous, endothelial-bound LPL. Higher concentrations caused additional binding. Both binding and exchange were rapid processes. The hearts continuously released endogenous LPL into the medium. An antiserum that inhibited bovine but not rat LPL was used to differentiate endogeneous and exogeneous LPL activity. When the pool of endothelial LPL was labeled with bovine 125I-labeled LPL and then chased with unlabeled bovine LPL, approximately 50% of the labeled lipase was rapidly displaced. During chase perfusion with medium only, catalytically active bovine LPL appeared in the perfusate. The rate of release was similar to that observed for endogeneous LPL activity and amounted to 10-13% of the heparin-releasable fraction in the first 5 min of perfusion. There was little or no degradation of bovine 125I-labeled LPL to fragments or acid-soluble products. These results indicate that endothelial LPL is accessible for exchange with exogeneous LPL and that detachment rather than degradation may be the pathway for catabolism of endothelial LPL

Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

Science.gov (United States)

Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

2017-05-01

Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

Myocardial perfusion imaging by digital subtraction angiography

International Nuclear Information System (INIS)

Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

1986-01-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

A Method for Mechanism Analysis of Frog Swimming Based on Motion Observation Experiments

Directory of Open Access Journals (Sweden)

Wei Zhang

2014-05-01

Full Text Available For understanding the mechanism of frog swimming under water and designing a frog-inspired swimming robot, kinematics of the frog body and trajectories of joints should be obtained. In this paper, an aquatic frog, Xenopus laevis, was chosen for analysis of swimming motions which were recorded by a high speed camera, and kinematic data were processed in a swimming data extraction platform. According to the shape features of the frog, we propose a method that the frog eyes are set as the natural data extraction markers for body motion, and kinematic data of joint trajectories are calculated by the contour points on the limbs. For the data processing, a pinhole camera model was built to transform the pixel coordinate system to world coordinate system, and the errors caused by the water refraction were analyzed and corrected. Finally, from the developed data extraction platform, the kinematic data for the analysis of swimming mechanism and design of frog-inspired robot were obtained.

Effect of forced-air heaters on perfusion and and temperature distribution during and after open-heart surgery

NARCIS (Netherlands)

Severens, N.M.W.; Marken Lichtenbelt, van W.; Leeuwen, van G.M.J.; Frijns, A.J.H.; Steenhoven, van A.A.; Mol, de B.A.J.M.; Wezel, H.B.; Veldman, D.J.

2007-01-01

Objectives: After cardiopulmonary bypass, patients often show redistribution hypothermia, also called afterdrop. Forced-air blankets help to reduce afterdrop. This study explores the effect of forced-air blankets on temperature distribution and peripheral perfusion. The blood perfusion data is used

Evaluation of pulmonary hypertension and surgical therapeutic efficacy using first-pass radionuclide pulmonary perfusion imaging in patients with pulmonary hypertension of valvular heart disease

International Nuclear Information System (INIS)

Wang Xuemei; Shi Rongfang; Fang Wei; Wang Daoyu; Zhou Baogui; Wang Qi; Pan Shiwei

2004-01-01

Objective: To evaluate pulmonary hypertension (PH) and surgical therapeutic efficacy using first-pass radionuclide pulmonary perfusion imaging (FPPPI) and pulmonary perfusion imaging (PPI) in patients with PH of valvular heart disease. Methods: One hundred and sixteen patients with valvular disease were included in the study. Swan-Ganz catheterization, echocardiography, FPPPI and PPI were performed on all patients before surgery. The patients were divided into four groups. Results: 1) Correlation coefficients were 0.856, 0.503 and 0.572 (P<0.01) between lung equilibrium time (LET) by FPPPI, superior lung/low lung ratio (S/L) by PPI , systolic pulmonary arterial pressure (SPAP) from echocardiography and SPAP from the catheter manometer. 2)The sensitivity, specificity and accuracy of PAP using FPPPI measuring were 94.7%, 68.3% and 85.3%, respectively. The sensitivity, specificity and accuracy of PAP using PPI measuring were 78.8%, 52.8% and 70.7%, respectively. The sensitivity, specificity and accuracy of PAP using FPPPI plus PPI measuring were 96.4%, 72.7% and 89.7%, respectively. 3)LET by FPPPI before surgery and 5-14 d after surgery were (27.71 ± 10.85) and (20.96 ± 6.25) s, respectively (P<0.001). SPL by PPI were 1.43 ± 0.41 and 1.30 ± 0.35, respectively (P<0.001). 4) Complete improvement rates of LET in the PAP slightly risen group, moderately risen group and weightily risen group were 47.6%, 34.5% and 1/4, respectively; part improvement rates of LET for corresponding groups were 40.5%, 62.1% and 3/4, respectively (P<0.001). Complete improvement rates of SPL were 31.0%, 34.5% and 0/4, respectively; part improvement rates of SPL were 35.7%, 55.2% and 3/4, respectively (P<0.05). Complete improvement rates of LET + SPL were 57.1%, 58.6% and 1/4; part improvement rates of LET+SPL were 38.1%, 41.4% and 3/4, respectively (P<0.01). Conclusions: 1)FPPPI is better than PPI and echocardiography for evaluating PH in valvular heart disease. 2)Combined FPPPI and PPI can

General concepts of ventricular function, Myocardial perfusion, and exercise physiology relevant to nuclear cardiology

International Nuclear Information System (INIS)

Kronenberg, M.W.; Becker, L.C.

1988-01-01

Knowledge of ventricular mechanics, the physiology of the coronary circulation, and exercise physiology is necessary for the accurate interpretation of radionuclide ventriculographic and myocardial perfusion images. This chapter outlines these important basic concepts as applied to the whole heart

FROG: The Fast And Realistic OpenGL Event Displayer

CERN Document Server

Quertenmont, Loic

2009-01-01

FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL [3] and GLUT [4] libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

Courtship in Frogs

Indian Academy of Sciences (India)

well-defined physical characteristics and a clear biological meaning. ... men t most successfully were the frogs and toads (hereafter referred ... Sound Pressure Level (SPL) in decibels = 20 loglOPt/Pr where,. Pt is the .... R.erythraea (left) and mean spectrum and sonagram of the female ... and egg laying activities initiated. 5.

Fast Doppler as a novel bedside measure of cerebral perfusion in preterm infants.

Science.gov (United States)

Peeples, Eric S; Mehic, Edin; Mourad, Pierre D; Juul, Sandra E

2016-02-01

Altered cerebral perfusion from impaired autoregulation may contribute to the morbidity and mortality associated with premature birth. We hypothesized that fast Doppler imaging could provide a reproducible bedside estimation of cerebral perfusion and autoregulation in preterm infants. This is a prospective pilot study using fast Doppler ultrasound to assess blood flow velocity in the basal ganglia of 19 subjects born at 26-32 wk gestation. Intraclass correlation provided a measure of test-retest reliability, and linear regression of cerebral blood flow velocity and heart rate or blood pressure allowed for estimations of autoregulatory ability. The intraclass correlation when imaging in the first 48 h of life was 0.634. We found significant and independent correlations between the systolic blood flow velocity and both systolic blood pressure and heart rate (P = 0.015 and 0.012 respectively) only in the 26-28 wk gestational age infants in the first 48 h of life. Our results suggest that fast Doppler provides reliable bedside measurements of cerebral blood flow velocity at the tissue level in premature infants, acting as a proxy for cerebral tissue perfusion. Additionally, autoregulation appears to be impaired in the extremely preterm infants, even within a normal range of blood pressures.

Low-Cost Optical Mapping Systems for Panoramic Imaging of Complex Arrhythmias and Drug-Action in Translational Heart Models

Science.gov (United States)

Lee, Peter; Calvo, Conrado J.; Alfonso-Almazán, José M.; Quintanilla, Jorge G.; Chorro, Francisco J.; Yan, Ping; Loew, Leslie M.; Filgueiras-Rama, David; Millet, José

2017-02-01

Panoramic optical mapping is the primary method for imaging electrophysiological activity from the entire outer surface of Langendorff-perfused hearts. To date, it is the only method of simultaneously measuring multiple key electrophysiological parameters, such as transmembrane voltage and intracellular free calcium, at high spatial and temporal resolution. Despite the impact it has already had on the fields of cardiac arrhythmias and whole-heart computational modeling, present-day system designs precludes its adoption by the broader cardiovascular research community because of their high costs. Taking advantage of recent technological advances, we developed and validated low-cost optical mapping systems for panoramic imaging using Langendorff-perfused pig hearts, a clinically-relevant model in basic research and bioengineering. By significantly lowering financial thresholds, this powerful cardiac electrophysiology imaging modality may gain wider use in research and, even, teaching laboratories, which we substantiated using the lower-cost Langendorff-perfused rabbit heart model.

Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

Science.gov (United States)

Zhang, Dian; Cui, Jianguo; Tang, Yezhong

2012-01-01

In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs) evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

Acute effects of nandrolone decanoate on oxidative stress in isolated rat heart

Directory of Open Access Journals (Sweden)

Jevđević Maja

2015-01-01

Full Text Available Abuse of anabolic-androgenic steroids (AAS produces side effects in different tissues, with oxidative stress linked to their pathophysiology, being involved in fibrosis, cellular proliferation, and tumorigenesis. The aim of this study was to examine the acute effects of nandrolone decanoate (ND on oxidative stress in isolated rat heart. The hearts of male Wistar albino were excised and perfused according to the Langendorff technique at gradually increasing coronary perfusion pressures (40-120 cmH2O. The hearts were perfused with ND at doses of 1, 10 and 100 μM. Oxidative stress markers, including the index of lipid peroxidation (thiobarbituric acid reactive substances (TBARS, nitric oxide (nitrites; NO2-, the superoxide anion radical (O2- and hydrogen peroxide (H2O2 were measured in the coronary venous effluent. Our results showed that acute effects of ND do not promote the production of reactive oxygen species (ROS. Our finding pointed out that the highest concentration of ND may even possess some anti-oxidative potential, which should be examined further.

The regulation of glucose transport in the heart of control and diabetic rats: With special emphasis on the glucose transporter

International Nuclear Information System (INIS)

Pleta, M. de Leoz.

1989-01-01

Glucose transport regulation with insulin and high perfusion pressure in the perfused rat hearts from control and diabetic rat hearts was investigated. [ 3 H]-cytochalasin B binding assay was used to study the distribution of glucose transporters within the subcellular membranes fractionated by linear sucrose density gradient centrifugation. In the present study, insulin increased glucose uptake in the perfused heart of control and diabetic animals. This coincided with an increase of glucose transporters on the plasma membrane. The increase in glucose transporters on the plasma membrane could not be accounted for by a decrease of glucose transporters from the microsomal membranes. High perfusion pressure did not change the number of glucose transporters on the plasma membrane compared to basal in the control and diabetic animals, though it increased glucose uptake above that observed for insulin in the control. Instead, high perfusion pressure altered the distribution of glucose transporters within the subcellular membranes in reverse to that with insulin, increasing an intermediate membrane pool believed to reside between the plasma membrane and microsomal membranes as well as the intracellular membrane pool

Regional cerebral perfusion in cardiovascular reflex syncope

International Nuclear Information System (INIS)

Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.

1997-01-01

Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

Poison frog colors are honest signals of toxicity, particularly for bird predators.

Science.gov (United States)

Maan, Martine E; Cummings, Molly E

2012-01-01

Antipredator defenses and warning signals typically evolve in concert. However, the extensive variation across taxa in both these components of predator deterrence and the relationship between them are poorly understood. Here we test whether there is a predictive relationship between visual conspicuousness and toxicity levels across 10 populations of the color-polymorphic strawberry poison frog, Dendrobates pumilio. Using a mouse-based toxicity assay, we find extreme variation in toxicity between frog populations. This variation is significantly positively correlated with frog coloration brightness, a viewer-independent measure of visual conspicuousness (i.e., total reflectance flux). We also examine conspicuousness from the view of three potential predator taxa, as well as conspecific frogs, using taxon-specific visual detection models and three natural background substrates. We find very strong positive relationships between frog toxicity and conspicuousness for bird-specific perceptual models. Weaker but still positive correlations are found for crab and D. pumilio conspecific visual perception, while frog coloration as viewed by snakes is not related to toxicity. These results suggest that poison frog colors can be honest signals of prey unpalatability to predators and that birds in particular may exert selection on aposematic signal design. © 2011 by The University of Chicago.

Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

Science.gov (United States)

Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

2008-02-01

We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

Myocardial perfusion MRI with sliding-window conjugate-gradient HYPR.

Science.gov (United States)

Ge, Lan; Kino, Aya; Griswold, Mark; Mistretta, Charles; Carr, James C; Li, Debiao

2009-10-01

First-pass perfusion MRI is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, signal-to-noise ratio (SNR), and cardiac motion-related image artifacts. In this study we investigated the feasibility of using a method that combines sliding window and CG-HYPR methods (SW-CG-HYPR) to reduce the acquisition window for each slice while maintaining the temporal resolution of one frame per heartbeat in myocardial perfusion MRI. This method allows an increased number of slices, reduced motion artifacts, and preserves the relatively high SNR and spatial resolution of the "composite images." Results from eight volunteers demonstrate the feasibility of SW-CG-HYPR for accelerated myocardial perfusion imaging with accurate signal intensity changes of left ventricle blood pool and myocardium. Using this method the acquisition time per cardiac cycle was reduced by a factor of 4 and the number of slices was increased from 3 to 8 as compared to the conventional technique. The SNR of the myocardium at peak enhancement with SW-CG-HYPR (13.83 +/- 2.60) was significantly higher (P < 0.05) than the conventional turbo-FLASH protocol (8.40 +/- 1.62). Also, the spatial resolution of the myocardial perfection images was significantly improved. SW-CG-HYPR is a promising technique for myocardial perfusion MRI. (c) 2009 Wiley-Liss, Inc.

Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

Science.gov (United States)

Kjørstad, Åsmund; Corteville, Dominique M R; Fischer, Andre; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

2014-08-01

To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation- and perfusion-related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow-ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method. The standard FD perfusion images are quantified by comparing the partially blood-filled pixels in the lung parenchyma with the fully blood-filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced-MRI. All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF-FD = 150 mL/min/100 mL, mean PBF-SEEPAGE = 151 mL/min/100 mL). The Bland-Altman plot shows a good spread of values, indicating no systematic bias between the methods. Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Copyright © 2013 Wiley Periodicals, Inc.

Nuclear medicine in the management of patients with heart failure: guidance from an expert panel of the International Atomic Energy Agency (IAEA).

Science.gov (United States)

Peix, Amalia; Mesquita, Claudio Tinoco; Paez, Diana; Pereira, Carlos Cunha; Felix, Renata; Gutierrez, Claudia; Jaimovich, Rodrigo; Ianni, Barbara Maria; Soares, Jose; Olaya, Pastor; Rodriguez, Ma Victoria; Flotats, Albert; Giubbini, Raffaele; Travin, Mark; Garcia, Ernest V

2014-08-01

Heart failure is increasing worldwide at epidemic proportions, resulting in considerable disability, mortality, and increase in healthcare costs. Gated myocardial perfusion single photon emission computed tomography or PET imaging is the most prominent imaging modality capable of providing information on global and regional ventricular function, the presence of intraventricular synchronism, myocardial perfusion, and viability on the same test. In addition, I-mIBG scintigraphy is the only imaging technique approved by various regulatory agencies able to provide information regarding the adrenergic function of the heart. Therefore, both myocardial perfusion and adrenergic imaging are useful tools in the workup and management of heart failure patients. This guide is intended to reinforce the information on the use of nuclear cardiology techniques for the assessment of heart failure and associated myocardial disease.

Modeling potential river management conflicts between frogs and salmonids

Science.gov (United States)

Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

2016-01-01

Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

Directory of Open Access Journals (Sweden)

Dian Zhang

Full Text Available In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

Renal perfusion scintiscan

Science.gov (United States)

... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

Cardiac MRI in ischemic heart disease

International Nuclear Information System (INIS)

Ishida, Masaki; Kato, Shingo; Sakuma, Hajime

2009-01-01

Considerable progress has been made in cardiac magnetic resonance imaging (MRI). Cine MRI is recognized as the most accurate method for evaluating ventricular function. Late gadolinium-enhanced MRI can clearly delineate subendocardial infarction, and the assessment of transmural extent of infarction on MRI is widely useful for predicting myocardial viability. Stress myocardial perfusion MRI allows for detection of subendocardial myocardial ischemia, and the diagnostic accuracy of stress perfusion MRI is superior to stress perfusion single-photon emission computed tomography in patients with multivessel coronary artery disease (CAD). In recent years, image quality, volume coverage, acquisition speed and arterial contrast of 3-dimensional coronary magnetic resonance angiography (MRA) have been substantially improved with use of steady-state free precession sequences and parallel imaging techniques, permitting the acquisition of high-quality, whole-heart coronary MRA within a reasonably short imaging time. It is now widely recognized that cardiac MRI has tremendous potential for the evaluation of ischemic heart disease. However, cardiac MRI is technically complicated and its use in clinical practice is relatively limited. With further improvements in education and training, as well as standardization of appropriate study protocols, cardiac MRI will play a central role in managing patients with CAD. (author)

Frog sound identification using extended k-nearest neighbor classifier

Science.gov (United States)

Mukahar, Nordiana; Affendi Rosdi, Bakhtiar; Athiar Ramli, Dzati; Jaafar, Haryati

2017-09-01

Frog sound identification based on the vocalization becomes important for biological research and environmental monitoring. As a result, different types of feature extractions and classifiers have been employed to evaluate the accuracy of frog sound identification. This paper presents a frog sound identification with Extended k-Nearest Neighbor (EKNN) classifier. The EKNN classifier integrates the nearest neighbors and mutual sharing of neighborhood concepts, with the aims of improving the classification performance. It makes a prediction based on who are the nearest neighbors of the testing sample and who consider the testing sample as their nearest neighbors. In order to evaluate the classification performance in frog sound identification, the EKNN classifier is compared with competing classifier, k -Nearest Neighbor (KNN), Fuzzy k -Nearest Neighbor (FKNN) k - General Nearest Neighbor (KGNN)and Mutual k -Nearest Neighbor (MKNN) on the recorded sounds of 15 frog species obtained in Malaysia forest. The recorded sounds have been segmented using Short Time Energy and Short Time Average Zero Crossing Rate (STE+STAZCR), sinusoidal modeling (SM), manual and the combination of Energy (E) and Zero Crossing Rate (ZCR) (E+ZCR) while the features are extracted by Mel Frequency Cepstrum Coefficient (MFCC). The experimental results have shown that the EKNCN classifier exhibits the best performance in terms of accuracy compared to the competing classifiers, KNN, FKNN, GKNN and MKNN for all cases.

Evaluation of myocardial involvement in Duchenne progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

International Nuclear Information System (INIS)

Kawai, Naoki; Yamamoto, Shuhei; Okada, Mitsuhiro

1983-01-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. The qualitative analysis was performed in anterior, 3 left anterior oblique and left lateral projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in LV posterolateral or posterior walls (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle changes or thoracic deformities assessed by transmission computed tomography. Slightly increased thallium-201 activity in RV free wall and lungs was shown in nine and one patient, respectively. The extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. The myocardial scintigraphic changes were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies in 2 to 3 years. It was concluded that the thallium myocardial perfusion imaging was a useful clinical technique to evaluate the cardiomyopathy in Duchenne progressive muscular dystrophy. (author)

Evaluation of myocardial involvement in Duchenne progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

Kawai, Naoki; Yamamoto, Shuhei; Okada, Mitsuhiro (Nagoya Univ. (Japan). Faculty of Medicine)

1983-12-01

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. The qualitative analysis was performed in anterior, 3 left anterior oblique and left lateral projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in LV posterolateral or posterior walls (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle changes or thoracic deformities assessed by transmission computed tomography. Slightly increased thallium-201 activity in RV free wall and lungs was shown in nine and one patient, respectively. The extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. The myocardial scintigraphic changes were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies in 2 to 3 years. It was concluded that the thallium myocardial perfusion imaging was a useful clinical technique to evaluate the cardiomyopathy in Duchenne progressive muscular dystrophy.

Sodium addition and/or oxygen saturation of iohexol during normal and reduced perfusion pressure

International Nuclear Information System (INIS)

Baath, L.

1990-01-01

The influence on contractile force (CF) and the propensity for ventricular fibrillation (VF) from infusing the non-ionic contrast medium iohexol during normal (75 cm H 2 O) and reduced perfusion pressure (35 cm H 2 O) were investigated in the isolated rabbit heart. Both during normal and reduced perfusion pressure iohexol (150 mg I/ml) with oxygen saturation caused a smaller reduction of CF than iohexol without oxygen. During reduced pressure iohexol with sodium addition (28 mM NaCl) caused less depression of CF than iohexol without sodium. The combination of sodium addition and oxygen saturation had the least influence on CF. Iohexol (350 mg I/ml) without sodium had a similar fibrillatory propensity during both normal and reduced pressure. Enriching iohexol with 28 mM NaCl decreased the risk of VF. The decrease was similar during both normal and reduced pressure. The risk of VF from oxygen saturation of iohexol (350 mg I/ml, without sodium) was similar during both normal and reduced pressure. It is concluded that a small addition of sodium and/or oxygen saturation of a non-ionic monomeric contrast medium have beneficial effects on the heart both during normal perfusion pressure and during ischemia. (orig.)

Biogeographic patterns of Colombian frogs and toads

International Nuclear Information System (INIS)

Lynch, John D.; Ruiz Carranza, Pedro M; Ardila Robayo, Maria Cristina

1997-01-01

Using the data provided in Ruiz-Carranza et al. (1996) the distributions of the 540 species of frogs and toads are partitioned among ten ecogeographic units of Colombia defined on the basis of precipitation and elevation. Some lowlands areas (pacific lowlands, Amazonian) exhibit high diversity (85-94 species) but lowlands areas in general are impoverished (30-52 species), especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and 121 species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rain forests. When biological endemicity is separated from political endemicity, five areas of high endemicity remain (the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the pacific lowlands). We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattern of diversification is by means of horizontal diversification (allopatric speciation) with a minor contribution from vertical diversification

Parasites of the mink frog (rana septentrionalis) from Minnesota, U.S.A.

Science.gov (United States)

Schotthoefer, Anna M.; Bolek, M.G.; Cole, Rebecca A.; Beasley, Val R.

2009-01-01

Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

Myocardial perfusion alterations observed months after radiotherapy are related to the cellular damage

Energy Technology Data Exchange (ETDEWEB)

Dogan, I.; Sonmez, B. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Nuclear Medicine; Sezen, O.; Zengin, A.Y.; Bahat, Z. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Radiation Oncology; Yenilmez, E.; Yulug, E. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Histology and Embryology; Abidin, I. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Biophysics

2010-07-01

Myocardial perfusion scintigraphy (MPS) is one of the widely used tools to follow developing radiation-induced heart disease (RIHD). But the clinical significance of MPS defects has not been fully understood. We have investigated the biodistribution alterations related to perfusion defects following radiotherapy (RT) and showed coexisting morphological changes. Animals, methods: A total of 18 Wistar rats were divided into three groups (1 control and 2 irradiated groups). A single cardiac 20 Gy radiation dose was used to induce long term cardiac defects. Biodistribution studies with technetium ({sup 99m}Tc) sestamibi and histological evaluations were performed 4 and 6 months after irradiation. The percent radioactivity (%ID/g) was calculated for each heart. For determination of the myocardial damage, positive apoptotic cardiomyocytes, myocardial cell degeneration, myocardial fibrosis, vascular damage and ultrastructural structures were evaluated. Results: Six months after treatment, a significant drop of myocardial uptake was observed (p < 0.05). Irradiation-induced apoptosis rose within the first 4 months after radiation treatment and were stayed elevated until the end of the observation period (p < 0.05). Also, the irradiation has induced myocardial degeneration, perivascular and interstitial fibrosis in the heart at the end of six and four months (p < 0.01). The severity and extent of myocardial injury has became more evident at the end of six month (p < 0.05). At ultrastructural level, prominent changes have been observed in the capillary endothelial and myocardial cells. Conclusion: Our findings suggest that the reduced rest myocardial perfusion, occuring months after the radiation, indicates a serious myocard tissue damage which is characterized by myocardial degeneration and fibrosis. (orig.)

Myocardial perfusion alterations observed months after radiotherapy are related to the cellular damage

International Nuclear Information System (INIS)

Dogan, I.; Sonmez, B.; Sezen, O.; Zengin, A.Y.; Bahat, Z.; Yenilmez, E.; Yulug, E.; Abidin, I.

2010-01-01

Myocardial perfusion scintigraphy (MPS) is one of the widely used tools to follow developing radiation-induced heart disease (RIHD). But the clinical significance of MPS defects has not been fully understood. We have investigated the biodistribution alterations related to perfusion defects following radiotherapy (RT) and showed coexisting morphological changes. Animals, methods: A total of 18 Wistar rats were divided into three groups (1 control and 2 irradiated groups). A single cardiac 20 Gy radiation dose was used to induce long term cardiac defects. Biodistribution studies with technetium ( 99m Tc) sestamibi and histological evaluations were performed 4 and 6 months after irradiation. The percent radioactivity (%ID/g) was calculated for each heart. For determination of the myocardial damage, positive apoptotic cardiomyocytes, myocardial cell degeneration, myocardial fibrosis, vascular damage and ultrastructural structures were evaluated. Results: Six months after treatment, a significant drop of myocardial uptake was observed (p < 0.05). Irradiation-induced apoptosis rose within the first 4 months after radiation treatment and were stayed elevated until the end of the observation period (p < 0.05). Also, the irradiation has induced myocardial degeneration, perivascular and interstitial fibrosis in the heart at the end of six and four months (p < 0.01). The severity and extent of myocardial injury has became more evident at the end of six month (p < 0.05). At ultrastructural level, prominent changes have been observed in the capillary endothelial and myocardial cells. Conclusion: Our findings suggest that the reduced rest myocardial perfusion, occuring months after the radiation, indicates a serious myocard tissue damage which is characterized by myocardial degeneration and fibrosis. (orig.)

The effect of rigor mortis on the passage of erythrocytes and fluid through the myocardium of isolated dog hearts.

Science.gov (United States)

Nevalainen, T J; Gavin, J B; Seelye, R N; Whitehouse, S; Donnell, M

1978-07-01

The effect of normal and artificially induced rigor mortis on the vascular passage of erythrocytes and fluid through isolated dog hearts was studied. Increased rigidity of 6-mm thick transmural sections through the centre of the posterior papillary muscle was used as an indication of rigor. The perfusibility of the myocardium was tested by injecting 10 ml of 1% sodium fluorescein in Hanks solution into the circumflex branch of the left coronary artery. In prerigor hearts (20 minute incubation) fluorescein perfused the myocardium evenly whether or not it was preceded by an injection of 10 ml of heparinized dog blood. Rigor mortis developed in all hearts after 90 minutes incubation or within 20 minutes of perfusing the heart with 50 ml of 5 mM iodoacetate in Hanks solution. Fluorescein injected into hearts in rigor did not enter the posterior papillary muscle and adjacent subendocardium whether or not it was preceded by heparinized blood. Thus the vascular occlusion caused by rigor in the dog heart appears to be so effective that it prevents flow into the subendocardium of small soluble ions such as fluorescein.

Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus

DEFF Research Database (Denmark)

Afzelius, P; Bergmann, A; Henriksen, J H

2015-01-01

/Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially......It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V...

Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats

Directory of Open Access Journals (Sweden)

CFD. Rocha

Full Text Available We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí, Espírito Santo (Praia das Neves and Setiba and Bahia (Prado and Trancoso. We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species, followed by Grussaí and Trancoso (eight species in each. The commonest species in the restingas was Scinax alter (found in eight restingas, followed by Aparasphenodon brunoi (seven areas. Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13°; p = 0.007. Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

Propulsive efficiency of frog swimming with different feet and swimming patterns

Directory of Open Access Journals (Sweden)

Fan Jizhuang

2017-04-01

Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

Simple motion correction strategy reduces respiratory-induced motion artifacts for k-t accelerated and compressed-sensing cardiovascular magnetic resonance perfusion imaging.

Science.gov (United States)

Zhou, Ruixi; Huang, Wei; Yang, Yang; Chen, Xiao; Weller, Daniel S; Kramer, Christopher M; Kozerke, Sebastian; Salerno, Michael

2018-02-01

Cardiovascular magnetic resonance (CMR) stress perfusion imaging provides important diagnostic and prognostic information in coronary artery disease (CAD). Current clinical sequences have limited temporal and/or spatial resolution, and incomplete heart coverage. Techniques such as k-t principal component analysis (PCA) or k-t sparcity and low rank structure (SLR), which rely on the high degree of spatiotemporal correlation in first-pass perfusion data, can significantly accelerate image acquisition mitigating these problems. However, in the presence of respiratory motion, these techniques can suffer from significant degradation of image quality. A number of techniques based on non-rigid registration have been developed. However, to first approximation, breathing motion predominantly results in rigid motion of the heart. To this end, a simple robust motion correction strategy is proposed for k-t accelerated and compressed sensing (CS) perfusion imaging. A simple respiratory motion compensation (MC) strategy for k-t accelerated and compressed-sensing CMR perfusion imaging to selectively correct respiratory motion of the heart was implemented based on linear k-space phase shifts derived from rigid motion registration of a region-of-interest (ROI) encompassing the heart. A variable density Poisson disk acquisition strategy was used to minimize coherent aliasing in the presence of respiratory motion, and images were reconstructed using k-t PCA and k-t SLR with or without motion correction. The strategy was evaluated in a CMR-extended cardiac torso digital (XCAT) phantom and in prospectively acquired first-pass perfusion studies in 12 subjects undergoing clinically ordered CMR studies. Phantom studies were assessed using the Structural Similarity Index (SSIM) and Root Mean Square Error (RMSE). In patient studies, image quality was scored in a blinded fashion by two experienced cardiologists. In the phantom experiments, images reconstructed with the MC strategy had higher

Nuclear cardiology and heart failure

International Nuclear Information System (INIS)

Giubbini, Raffaele; Bertagna, Francesco; Milan, Elisa; Mut, Fernando; Dondi, Maurizio; Metra, Marco; Rodella, Carlo

2009-01-01

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

Nuclear cardiology and heart failure

Energy Technology Data Exchange (ETDEWEB)

Giubbini, Raffaele; Bertagna, Francesco [University of Brescia, Department of Nuclear Medicine, Brescia (Italy); Milan, Elisa [Ospedale Di Castelfranco Veneto, Nuclear Medicine Unit, Castelfranco Veneto (Italy); Mut, Fernando; Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Metra, Marco [University of Brescia, Department of Cardiology, Brescia (Italy); Rodella, Carlo [Health Physics Department, Spedali Civili di Brescia, Brescia (Italy)

2009-12-15

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

Introducing the Forensic Research/Reference on Genetics knowledge base, FROG-kb.

Science.gov (United States)

Rajeevan, Haseena; Soundararajan, Usha; Pakstis, Andrew J; Kidd, Kenneth K

2012-09-01

Online tools and databases based on multi-allelic short tandem repeat polymorphisms (STRPs) are actively used in forensic teaching, research, and investigations. The Fst value of each CODIS marker tends to be low across the populations of the world and most populations typically have all the common STRP alleles present diminishing the ability of these systems to discriminate ethnicity. Recently, considerable research is being conducted on single nucleotide polymorphisms (SNPs) to be considered for human identification and description. However, online tools and databases that can be used for forensic research and investigation are limited. The back end DBMS (Database Management System) for FROG-kb is Oracle version 10. The front end is implemented with specific code using technologies such as Java, Java Servlet, JSP, JQuery, and GoogleCharts. We present an open access web application, FROG-kb (Forensic Research/Reference on Genetics-knowledge base, http://frog.med.yale.edu), that is useful for teaching and research relevant to forensics and can serve as a tool facilitating forensic practice. The underlying data for FROG-kb are provided by the already extensively used and referenced ALlele FREquency Database, ALFRED (http://alfred.med.yale.edu). In addition to displaying data in an organized manner, computational tools that use the underlying allele frequencies with user-provided data are implemented in FROG-kb. These tools are organized by the different published SNP/marker panels available. This web tool currently has implemented general functions possible for two types of SNP panels, individual identification and ancestry inference, and a prediction function specific to a phenotype informative panel for eye color. The current online version of FROG-kb already provides new and useful functionality. We expect FROG-kb to grow and expand in capabilities and welcome input from the forensic community in identifying datasets and functionalities that will be most helpful

Birds and frogs in mathematics and physics

Energy Technology Data Exchange (ETDEWEB)

Dyson, Freeman J [Institute for Advanced Study, Princeton, NJ (United States)

2010-11-15

Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

Birds and frogs in mathematics and physics

International Nuclear Information System (INIS)

Dyson, Freeman J

2010-01-01

Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

Enhanced preservation of the isolated rat heart after hypothermic storage by pinacidil pretreatment and storage in lazaroid U74500A

International Nuclear Information System (INIS)

Hicks, M.; Du, Z.Y.; Spratt, P.; Macdonald, P.

1998-01-01

The aim of the present study was to compare 3 protocols incorporating these approaches on the preservation of haemodynamic function in the isolated working rat heart after hypothermic storage. These protocols were: 1) pretreatment of the heart with 200 μM pinacidil, an ATP-sensitive potassium channel opener; 2) storage in cardioplegic solution containing the lipid soluble lazaroid antioxidant U74500A (30 μM); 3) A combination of protocols 1 and 2. Methods: Hearts from Wistar rats (250 to 330g body weight) were perfused on a Langendorff apparatus. Each heart was ligated to an aortic cannula and perfused retrogradely, with oxygenated Krebs solution at a hydrostatic pressure of 100 cm H 2 O. The system was then converted to 'working mode' by switching the perfusate from aorta to a left atrial cannula (filling pressure 15 cm H 2 O). After stabilisation, the following pre-arrest indices of cardiac function were recorded: heart rate (HR), coronary flow (CF), aortic flow (AF) and cardiac output (CO). Hearts were then randomised to protocols 1-3, untreated controls or vehicle treated controls (n=6 animals/ group). Hearts were stored in an extracellular-based preservation solution for 12 hours at 2-3degC, remounted on the perfusion apparatus and stabilised as before. Haemodynamic measurements were then repeated. Conclusions: Combined pharmacological activation of ATP-sensitive potassium channels before cardioplegia and the addition of U74500A to the preservation solution is associated with a significantly enhanced haemodynamic function in the rat heart after 12 hours of hypothermic storage. These data suggest a novel use for these agents in the transplantation context

Enhanced preservation of the isolated rat heart after hypothermic storage by pinacidil pretreatment and storage in lazaroid U74500A

Energy Technology Data Exchange (ETDEWEB)

Hicks, M. [St Vincent`s Hospital, Darlinghurst, NSW (Australia). Division of Clinical Pharmacology and Toxicology; Du, Z.Y.; Spratt, P.; Macdonald, P. [St Vincent`s Hospital, Darlinghurst, NSW (Australia). Cardiopulmonary Transplant Unit

1998-12-31

The aim of the present study was to compare 3 protocols incorporating these approaches on the preservation of haemodynamic function in the isolated working rat heart after hypothermic storage. These protocols were: 1) pretreatment of the heart with 200 {mu}M pinacidil, an ATP-sensitive potassium channel opener; 2) storage in cardioplegic solution containing the lipid soluble lazaroid antioxidant U74500A (30 {mu}M); 3) A combination of protocols 1 and 2. Methods: Hearts from Wistar rats (250 to 330g body weight) were perfused on a Langendorff apparatus. Each heart was ligated to an aortic cannula and perfused retrogradely, with oxygenated Krebs solution at a hydrostatic pressure of 100 cm H{sub 2}O. The system was then converted to `working mode` by switching the perfusate from aorta to a left atrial cannula (filling pressure 15 cm H{sub 2}O). After stabilisation, the following pre-arrest indices of cardiac function were recorded: heart rate (HR), coronary flow (CF), aortic flow (AF) and cardiac output (CO). Hearts were then randomised to protocols 1-3, untreated controls or vehicle treated controls (n=6 animals/ group). Hearts were stored in an extracellular-based preservation solution for 12 hours at 2-3degC, remounted on the perfusion apparatus and stabilised as before. Haemodynamic measurements were then repeated. Conclusions: Combined pharmacological activation of ATP-sensitive potassium channels before cardioplegia and the addition of U74500A to the preservation solution is associated with a significantly enhanced haemodynamic function in the rat heart after 12 hours of hypothermic storage. These data suggest a novel use for these agents in the transplantation context Truncated abstract. 1 tab.

Resting cardiointegram: correlation with stress thallium perfusion studies

International Nuclear Information System (INIS)

Gould, L.A.; Betzu, R.; Judge, D.; Lee, J.; Taddeo, M.; Yang, D.

1988-01-01

The cardiointegram is a noninvasive technique for the analysis of the electrical signals of the heart obtained by a transformation of the voltage versus time format by a series of integrations. The stress thallium perfusion study is a widely used test for the detection of coronary artery disease. In order to evaluate the correlation between the resting cardiointegram and the stress thallium 201 perfusion study, 20 patients with normal resting electrocardiograms underwent stress thallium tests and resting cardiointegrams. The cardiointegram was determined on two resting complexes of leads I, II, V4, V5, and V6 and called abnormal if five of ten complexes deviated outside a normalized template. There was concordance of the cardiointegram and the thallium study in 16 of 20 patients (80%). The sensitivity for the detection of coronary artery disease was 71%, and the specificity was 80%. The overall accuracy was 74%. Thus in patients with normal electrocardiograms, the cardiointegram is a useful noninvasive test for the detection of coronary artery disease

Use of femur bone density to segregate wild from farmed Dybowski's frog (Rana dybowskii).

Science.gov (United States)

Yang, Shu Hui; Huang, Xiao Ming; Xia, Rui; Xu, Yan Chun; Dahmer, Thomas D

2011-04-15

Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Sex- and age-related differences of myocardial perfusion at rest assessed with multidetector computed tomography

DEFF Research Database (Denmark)

Byrne, Christina; Kühl, J Tobias; Zacho, Mette

2013-01-01

The clinical presentation of ischemic heart disease in women differs from men, which could reflect sex-related differences of normal physiology. Cardiac CT angiography provides a noninvasive method to assess both regional and transmural myocardial perfusion in addition to coronary atherosclerosis....

Effects of a novel multimodal group intervention on myocardial perfusion in patients with coronary heart disease (CHD)

International Nuclear Information System (INIS)

Theissen, P.; Schicha, H.; Albus, C.; Koehle, K.; Griebenow, R.; Son, P.

2002-01-01

Full text: Recently, it could be shown that a multimodal intervention can promote health behavior in patients with CHD. Purpose of the actual study was to evaluate the effects on somatic endpoints, e.g. myocardial perfusion. We randomly assigned 77 patients (age 54 ± 6.9 y, male 87 %) with angiographically documented CHD to a multimodal group intervention plus standardized cardiological care (INT n=39) or standardized cardiological care only (CO n = 38). The intervention, for out-patients only, consisted of 77.5 hours of group-psychotherapy, relaxation and exercise training, and teaching lessons for one year. A Thallium myocardial perfusion scintigraphy (MyoSc) (after bicycle exercise test and at rest; 70 - 110 MBq Thallium-201, SPECT-technique, quantitative wash-out (w.-o.) analysis derived from polar maps) was performed at baseline, after 2 years, and 3 years, respectively: A w.-o. increase res. decrease by 5 % or more indicated an improved / a diminished myocardial perfusion within the affected coronary artery territory. Results were analyzed on an intention to treat basis. 70/77 patients (91 %) completed the study (drop-outs CO n=4, INT n=3). After 2 years (1st interval), there was no significant difference between groups. After 3 years (2nd interval) 36/39 patients (92.3 %) of INT showed a stable or improved myocardial perfusion, compared to 18/38 patients (47.4 %) of CO (p= 0.008). The recent data analysis demonstrates the extra benefit of a multimodal intervention, compared to standardized cardiological care alone, on myocardial perfusion in CHD patients. (author)

Determination of age, longevity and age at reproduction of the frog ...

Indian Academy of Sciences (India)

Unknown

separately in plastic bags and placed in 5 different aquaria. Each frog was anaesthetized (using anaesthetic ether), the body mass ... bone of each frog, were measured using an ocular .... One of the problems generally associated with skeleto-.

Preliminary study of single contrast enhanced dual energy heart imaging using dual-source CT

International Nuclear Information System (INIS)

Peng Jin; Zhang Longjiang; Zhou Changsheng; Lu Guangming; Ma Yan; Gu Haifeng

2009-01-01

Objective: To evaluate the feasibility and preliminary applications of single contrast enhanced dual energy heart imaging using dual-source CT (DSCT). Methods: Thirty patients underwent dual energy heart imaging with DSCT, of which 6 cases underwent SPECT or DSA within one week. Two experienced radiologists assessed image quality of coronary arteries and iodine map of myocardium. and correlated the coronary artery stenosis with the perfusion distribution of iodine map. Results: l00% (300/300) segments reached diagnostic standards. The mean score of image for all patients was 4.68±0.57. Mural coronary artery was present in 10 segments in S cases, atherosclerotic plaques in 32 segments in 12 cases, of which 20 segments having ≥50% stenosis, 12 segments ≤50% stenosis; dual energy CT coronary angiography was consistent with the DSA in 3 patients. 37 segmental perfusion abnormalities on iodine map were found in 15 cases, including 28 coronary blood supply segment narrow segment and 9 no coronary stenosis (including three negative segments in SPECD. Conclusion: Single contrast enhanced dual energy heart imaging can provide good coronary artery and myocardium perfusion images in the patients with appropriate heart rate, which has a potential to be used in the clinic and further studies are needed. (authors)

Female preferences for aposematic signal components in a polymorphic poison frog

NARCIS (Netherlands)

Maan, Martine E.; Cummings, Molly E.

Aposematic signals may be subject to conflicting selective pressures from predators and conspecifics. We studied female preferences for different components of aposematic coloration in the polymorphic poison frog Oophaga pumilio across several phenotypically distinct populations. This frog shows

Antimicrobial peptides from the skins of North American frogs.

Science.gov (United States)

Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

2009-08-01

North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

Selective cerebro-myocardial perfusion in complex congenital aortic arch pathology: a novel technique.

Science.gov (United States)

De Rita, Fabrizio; Lucchese, Gianluca; Barozzi, Luca; Menon, Tiziano; Faggian, Giuseppe; Mazzucco, Alessandro; Luciani, Giovanni Battista

2011-11-01

Simultaneous cerebro-myocardial perfusion has been described in neonatal and infant arch surgery, suggesting a reduction in cardiac morbidity. Here reported is a novel technique for selective cerebral perfusion combined with controlled and independent myocardial perfusion during surgery for complex or recurrent aortic arch lesions. From April 2008 to April 2011, 10 patients with arch pathology underwent surgery (two hypoplastic left heart syndrome [HLHS], four recurrent arch obstruction, two aortic arch hypoplasia + ventricular septal defect [VSD], one single ventricle + transposition of the great arteries + arch hypoplasia, one interrupted aortic arch type B + VSD). Median age was 63 days (6 days-36 years) and median weight 4.0 kg (1.6-52). Via midline sternotomy, an arterial cannula (6 or 8 Fr for infants) was directly inserted into the innominate artery or through a polytetrafluoroethylene (PTFE) graft (for neonates cerebro-myocardial perfusion was 39 ± 18 min (17-69). Weaning from cardiopulmonary bypass was achieved without inotropic support in three and with low dose in seven patients. One patient required veno-arterial extracorporeal membrane oxygenation. Four patients, body weight cerebro-myocardial perfusion is feasible in patients with complex or recurrent aortic arch disease, starting from premature newborn less than 2.0 kg of body weight to adults. The technique is as safe as previously reported methods of cerebro-myocardial perfusion and possibly more versatile. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Environmental and Host Effects on Skin Bacterial Community Composition in Panamanian Frogs

Directory of Open Access Journals (Sweden)

Brandon J. Varela

2018-02-01

Full Text Available Research on the amphibian skin microbiota has focused on identifying bacterial taxa that deter a pathogenic chytrid fungus, and on describing patterns of microbiota variation. However, it remains unclear how environmental variation affects amphibian skin bacterial communities, and whether the overall functional diversity of the amphibian skin microbiota is associated to such variation. We sampled skin microbial communities from one dendrobatoid frog species across an environmental gradient along the Panama Canal, and from three dendrobatoid frog species before and after the onset of the wet season in one site. We found frog skin microbial alpha diversity to be highest in frogs from sites with low soil pH, but no clear effect of the onset of the wet season. However, we found frog skin microbial community structure to be affected by soil pH and the onset of the wet season, which also resulted in a decrease in between-sample variation. Across the sampled frog species, bacterial functional groups changed with the onset of the wet season, with certain bacterial functional groups entirely disappearing and others differing in their relative abundances. In particular, we found the proportion of Bd-inhibitory bacteria to correlate with mean soil pH, and to increase in two of the frog species with the onset of the wet season. Taken together, our results suggest that structure and predicted function of amphibian bacterial skin communities may be influenced by environmental variables such as pH and precipitation, site effects, and host effects.

Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834

Directory of Open Access Journals (Sweden)

Achariya Sailasuta

2011-01-01

Full Text Available One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834, were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140 were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia.

Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834)

Science.gov (United States)

Sailasuta, Achariya; Satetasit, Jetjun; Chutmongkonkul, Malinee

2011-01-01

One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834), were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140) were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs) surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia. PMID:21918731

The relationship between ventilatory lung motion and pulmonary perfusion shown by ventilatory lung motion imaging

International Nuclear Information System (INIS)

Fujii, Tadashige; Tanaka, Masao; Nakatsuka, Tatsuya; Yoshimura, Kazuhiko; Hirose, Yoshiki; Hirayama, Jiro; Kobayashi, Toshio; Handa, Kenjiro

1991-01-01

Using ventilatory lung motion imaging, which was obtained from two perfusion lung scintigrams with 99m Tc-macroaggregated albumin taken in maximal inspiration and maximal expiration, the lung motion (E-I/I) of the each unilateral lung was studied in various cardiopulmonary diseases. The sum of (E-I)/I(+) of the unilateral lung was decreased in the diseased lung for localized pleuropulmonary diseases, including primary lung cancer and pleural thickening, and in both lungs for heart diseases, and diffuse pulmonary diseases including diffuse interstitial pneumonia and diffuse panbronchiolitis. The sum of (E-I)/I(+) of the both lungs, which correlated with vital capacity and PaO 2 , was decreased in diffuse interstitial pneumonia, pulmonary emphysema, diffuse panbronchiolitis, primary lung cancer, pleural diseases and so on. (E-I)/I(+), correlated with pulmonary perfusion (n=49, r=0.51, p 81m Kr or 133 Xe (n=49, r=0.61, p<0.001) than pulmonary perfusion. The ventilatory lung motion imaging, which demonstrates the motion of the intra-pulmonary areas and lung edges, appears useful for estimating pulmonary ventilation of the perfused area as well as pulmonary perfusion. (author)

Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

Science.gov (United States)

de Sá, Fábio P; Zina, Juliana; Haddad, Célio F B

2016-01-01

Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

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Fábio P de Sá

Full Text Available Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids, we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

THE MOCHE BOTANICAL FROG (La rana botánica mochica

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Donna McClelland †

2011-06-01

Full Text Available Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog performing as part of a ritual involving other animals and cultivated crops, suggesting that the Botanical Frog was associated with agriculture. ESPAÑOL: El arte de la cultura mochica de la costa norte del Perú presenta plantas y animales mostrando rasgos sobrenaturales. Uno de los animales es una rana con elementos felinos y asociada con tubérculos, ramas y plantas de yuca. La Rana Botánica probablemente tiene su origen en Leptodactylus pentadactylus, una rana carnívora de la selva amazónica. La Rana Botánica copula con felinos y, en vasijas pintadas con líneas finas o con escenarios representados en bajorrelieve, toma parte en ceremonias involucrando a otros animales y cosechas domésticas. Parece ser que la Rana Botánica era un ser sobrenatural asociado con la agricultura.

Biodistribution and stability studies of [18F]Fluoroethylrhodamine B, a potential PET myocardial perfusion agent

International Nuclear Information System (INIS)

Gottumukkala, Vijay; Heinrich, Tobias K.; Baker, Amanda; Dunning, Patricia; Fahey, Frederic H.; Treves, S. Ted; Packard, Alan B.

2010-01-01

Introduction: Fluorine-18-labeled rhodamine B was developed as a potential positron emission tomography (PET) tracer for the evaluation of myocardial perfusion, but preliminary studies in mice showed no accumulation in the heart suggesting that it was rapidly hydrolyzed in vivo in mice. A study was therefore undertaken to further evaluate this hypothesis. Methods: [ 18 F]Fluoroethylrhodamine B was equilibrated for 2 h at 37 deg. C in human, rat and mouse serum and in phosphate-buffered saline. Samples were removed periodically and assayed by high-performance liquid chromatography. Based on the results of the stability study, microPET imaging and a biodistribution study were carried out in rats. Results: In vitro stability studies demonstrated that [ 18 F]fluoroethylrhodamine B much more stable in rat and human sera than in mouse serum. After 2 h, the compound was >80% intact in rat serum but 18 F-labeled rhodamines should accumulate in the heart. Conclusions: [ 18 F]Fluoroethylrhodamine B is more stable in rat and human sera than it is in mouse serum. This improved stability is demonstrated by the high uptake of the tracer in the rat heart in comparison to the absence of visible uptake in the mouse heart. These observations suggest that 18 F-labeled rhodamines are promising candidates for more extensive evaluation as PET tracers for the evaluation of myocardial perfusion.

Pomegranate Extract Enhances Endothelium-Dependent Coronary Relaxation in Isolated Perfused Hearts from Spontaneously Hypertensive Ovariectomized Rats

Science.gov (United States)

Delgado, Nathalie T. B.; Rouver, Wender do N.; Freitas-Lima, Leandro C.; de Paula, Tiago D.-C.; Duarte, Andressa; Silva, Josiane F.; Lemos, Virgínia S.; Santos, Alexandre M. C.; Mauad, Helder; Santos, Roger L.; Moysés, Margareth R.

2017-01-01

Decline in estrogen levels promotes endothelial dysfunction and, consequently, the most prevalent cardiovascular diseases in menopausal women. The use of natural therapies such as pomegranate can change these results. Pomegranate [Punica granatum L. (Punicaceae)] is widely used as a phytotherapeutic agent worldwide, including in Brazil. We hypothesized that treatment with pomegranate hydroalcoholic extract (PHE) would improve coronary vascular reactivity and cardiovascular parameters. At the beginning of treatment, spontaneously hypertensive female rats were divided into Sham and ovariectomized (OVX) groups, which received pomegranate extract (PHE) (250 mg/kg) or filtered water (V) for 30 days by gavage. Systolic blood pressure was measured by tail plethysmography. After euthanasia, the heart was removed and coronary vascular reactivity was assessed by Langendorff retrograde perfusion technique. A dose-response curve for bradykinin was performed, followed by L-NAME inhibition. The protein expression of p-eNOS Ser1177, p-eNOS Thr495, total eNOS, p-AKT Ser473, total AKT, SOD-2, and catalase was quantified by Western blotting. The detection of coronary superoxide was performed using the protocol of dihydroethidium (DHE) staining Plasma nitrite measurement was analyzed by Griess method. Systolic blood pressure increased in both Sham-V and OVX-V groups, whereas it was reduced after treatment in Sham-PHE and OVX-PHE groups. The baseline coronary perfusion pressure was reduced in the Sham-PHE group. The relaxation was significantly higher in the treated group, and L-NAME attenuated the relaxation in all groups. The treatment has not changed p-eNOS (Ser1177), total eNOS, p-AKT (Ser473) and total AKT in any groups. However, in Sham and OVX group the treatment reduced the p-eNOS (Thr495) and SOD-2. The ovariectomy promoted an increasing in the superoxide anion levels and the treatment was able to prevent this elevation and reducing oxidative stress. Moreover, the treatment

Development of 99Tcm-Q3 as a new type myocardial perfusion imaging agent

International Nuclear Information System (INIS)

Li Yunchun; Tan Tianzhi; Fan Chengzhong; Zhao Keqing; Wei Xihe; Li Quan

1999-01-01

Objective: To develop 99 Tc m -N,N'-ethylene-bis (acetylacetone iminato) bis [tris (3-methoxy-1-propyl) phosphine] ( 99 Tc m -Q 3 ) as a new type of myocardial perfusion imaging agent. Methods: After N,N'-ethylene-bis (acetylacetone iminato) and tris (3-methoxy-1-propyl) phosphine were made, N,N'-ethylene-bis (acetylacetone iminato) was labelled using reduced 99 Tc m O 4 - by SnCl 2 ·2H 2 O under the presence of alkali, then tris (3-methoxy-1-propyl) phosphine was added and reacted for ten minutes, 99 Tc m -Q 3 was obtained at the end. Biodistribution in mice, in vitro stability and acute toxicity of 99 Tc m -Q 3 were examined. Results: 99 Tc m -Q 3 was taken up rapidly by the heart, and the uptake rate was very high, by 5 minutes post injection, 24.66% of the injected dose was taken up in per gram heart, and no significant washout was shown up by 4 hours. But 99 Tc m -Q 3 was cleaned out rapidly from blood, lung and liver. No poisonousness and adverse effects were observed, and its stability lasted more than 6 hours. Conclusions: 99 Tc m -Q 3 is a fairly good myocardial perfusion imaging agent for improving the quality of myocardial perfusion imaging

Field guide to malformations of frogs and toads: with radiographic interpretations

Science.gov (United States)

Meteyer, Carol U.

2000-01-01

In 1995, students found numerous malformed frogs on a field trip to a Minnesota pond. Since that time, reports of malformed frogs have increased dramatically. Malformed frogs have now been reported in 44 states in 38 species of frogs, and 19 species of toads. Estimates as high as 60% of the newly metamorphosed frog populations have had malformations at some ponds (NARCAM, ’99). The wide geographic distribution of malformed frogs and the variety of malformations are a concern to resource managers, research scientists and public health officials. The potential for malformations to serve as a signal of ecosystem disruption, and the affect this potential disruption might have on other organisms that share those ecosystems, has not been resolved. Malformations represent an error that occurred early in development. The event that caused the developmental error is temporally distant from the malformation we see in the fully developed animal. Knowledge of normal developmental principles is necessary to design thoughtful investigations that will define the events involved in abnormal development in wild frog populations.Development begins at the time an egg is fertilized and progresses by chemical communication between cells and cell layers. This communication is programmed through gene expression. Malformations represent primary errors in development, errors in chemical communication or translation of genetic information. Deformations arise later in development and usually result from the influence of mechanical factors (such as amputation) that alter shape or anatomy of a structure that has developed normally. The occurrence and the type of malformations are influenced by the type of error or insult as well as the timing of the error (the developmental stage at which the error occurred). The appearance of the malformation can therefore provide clues that suggest when the error may have occurred. If the malformation is an incomplete organ, such as an incomplete limb, the

Nitric oxide fails to confer endogenous antiarrhythmic cardioprotection in the primate heart in vitro.

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Pabla, R; Curtis, M J

2007-04-01

The role of nitric oxide (NO) in cardiac pathophysiology remains controversial. According to data from several studies using rat and rabbit isolated hearts, NO is an endogenous cardioprotectant against reperfusion-induced ventricular fibrillation (VF). Thus, if cardiac NO production is abolished by perfusion with L-N(G)-nitro-L-arginine methylester (L-NAME) (100 microM) there is a concomittant increase in the incidence of reperfusion-induced VF, with L-NAME's effects on NO and VF prevented by L- (but not D-) arginine co-perfusion. To make a better estimate of the clinical relevance of these findings, 100 microM L-NAME was tested in primate hearts under similar conditions. Marmoset (Callithrix jaccus) hearts, isolated and perfused, were subjected to 60 min left regional ischaemia followed by 10 min reperfusion in vitro. The ECG was recorded and NO in coronary effluent measured by chemiluminescence. L-NAME (100 micro M) decreased NO in coronary effluent throughout ischaemia and reperfusion (e.g. from 3720+/-777 pmol min(-1) g(-1) in controls to 699+/-98 pmol min(-1) g(-1) after 5 min of ischaemia) and, during ischaemia, lowered coronary flow and reduced heart rate, actions identical to those seen in rat and rabbit hearts. However, the incidence of reperfusion-induced VF was unchanged (20%, with or without L-NAME). A species difference exists in the effectiveness of endogenous NO to protect hearts against reperfusion-induced VF. The present primate data, which presumably take precedence over rat and rabbit data, cast doubt on the clinical relevance of NO as an endogenous, antiarrhythmic, cardioprotectant.

The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae: incipient gigantism?

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Marcio Mageski

2015-10-01

Full Text Available ABSTRACT The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824, is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espírito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.

Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs.

Science.gov (United States)

Bernal, Ximena E; Pinto, C Miguel

2016-04-01

Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria ...

African Journals Online (AJOL)

Frogs are among the most threatened species of wildlife in IUCN red list. Its utilisation in Ibadan, a major depot in western Nigeria was therefore conducted with the aim of assessing the forms and trend of use; and amongst others, reasons for frog meat consumption. Data for the study were collected through questionnaire, ...

Significance of myoglobin as an oxygen store and oxygen transporter in the intermittently perfused human heart: a model study.

Science.gov (United States)

Endeward, Volker; Gros, Gerolf; Jürgens, Klaus D

2010-07-01

The mechanisms by which the left ventricular wall escapes anoxia during the systolic phase of low blood perfusion are investigated, especially the role of myoglobin (Mb), which can (i) store oxygen and (ii) facilitate intracellular oxygen transport. The quantitative role of these two Mb functions is studied in the maximally working human heart. Because discrimination between Mb functions has not been achieved experimentally, we use a Krogh cylinder model here. At a heart rate of 200 beats/min and a 1:1 ratio of diastole/systole, the systole lasts for 150 ms. The basic model assumption is that, with mobile Mb, the oxygen stored in the end-diastolic left ventricle wall exactly meets the demand during the 150 ms of systolic cessation of blood flow. The coronary blood flow necessary to achieve this agrees with literature data. By considering Mb immobile or setting its concentration to zero, respectively, we find that, depending on Mb concentration, Mb-facilitated O(2) transport maintains O(2) supply to the left ventricle wall during 22-34 of the 150 ms, while Mb storage function accounts for a further 12-17 ms. When Mb is completely absent, anoxia begins to develop after 116-99 ms. While Mb plays no significant role during diastole, it supplies O(2) to the left ventricular wall for < or = 50 ms of the 150 ms systole, whereas capillary haemoglobin is responsible for approximately 80 ms. Slight increases in haemoglobin concentration, blood flow, or capillary density can compensate the absence of Mb, a finding which agrees well with the observations using Mb knockout mice.

The redesigned Forensic Research/Reference on Genetics-knowledge base, FROG-kb.

Science.gov (United States)

Kidd, Kenneth K; Soundararajan, Usha; Rajeevan, Haseena; Pakstis, Andrew J; Moore, Katherine N; Ropero-Miller, Jeri D

2018-03-01

The Forensic Resource/Reference on Genetics-knowledge base (FROG-kb) web site was introduced in 2011 and in the five years since the previous publication ongoing research into how the database can better serve forensics has resulted in extensive redesign of the database interface and functionality. Originally designed as a prototype to support forensic use of single nucleotide polymorphisms (SNPs), FROG-kb provides a freely accessible web interface that facilitates forensic practice and can be useful for teaching and research. Based on knowledge gained through its use, the web interface has been redesigned for easier navigation through the multiple components. The site also has functional enhancements, extensive new documentation, and new reference panels of SNPs with new curated data. FROG-kb focuses on single nucleotide polymorphisms (SNPs) and provides reference population data for several published panels of individual identification SNPs (IISNPs) and several published panels of ancestry inference SNPs (AISNPs). For each of the various marker panels with reference population data, FROG-kb calculates random match probabilities (RMP) and relative likelihoods of ancestry for a user-entered genotype profile (either completely or partially specified). Example genotype profiles are available and the User's Manual presents interpretation guidelines for the calculations. The extensive documentation along with ongoing updates makes FROG-kb a comprehensive tool in facilitating use of SNPs in forensic practice and education. An overview of the new FROG-kb with examples and material explaining the results of its use are presented here. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Propulsive force calculations in swimming frogs I. A momentum-impulse approach

NARCIS (Netherlands)

Nauwelaerts, S; Stamhuis, EJ; Aerts, P

Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we

Consecutive Isoproterenol and Adenosine Treatment Confers Marked Protection against Reperfusion Injury in Adult but Not in Immature Heart: A Role for Glycogen

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Martin Lewis

2018-02-01

Full Text Available Consecutive treatment of adult rat heart with isoproterenol and adenosine (Iso/Aden, known to consecutively activate PKA/PKC signaling, is cardioprotective against ischemia and reperfusion (I/R. Whether this is cardioprotective in an immature heart is unknown. Langendorff–perfused hearts from adult and immature (60 and 14 days old male Wistar rats were exposed to 30 min ischemia and 120 min reperfusion, with or without prior perfusion with 5 nM Iso for 3 min followed by 30 μM Aden for 5 min. Changes in hemodynamics (developed pressure and coronary flow and cardiac injury (Lactate Dehydrogenase (LDH release and infarct size were measured. Additional hearts were used to measure glycogen content. Iso induced a similar inotropic response in both age groups. Treatment with Iso/Aden resulted in a significant reduction in time to the onset of ischemic contracture in both age groups whilst time to peak contracture was significantly shorter only in immature hearts. Upon reperfusion, the intervention reduced cardiac injury and functional impairment in adults with no protection of immature heart. Immature hearts have significantly less glycogen content compared to adult. This work shows that Iso/Aden perfusion confers protection in an adult heart but not in an immature heart. It is likely that metabolic differences including glycogen content contribute to this difference.

Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

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Mark-Oliver Rödel

Full Text Available Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus. The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.

Myocardial images in nonacute coronary and noncoronary heart diseases

International Nuclear Information System (INIS)

Poe, N.D.; Eber, L.M.; Norman, A.S.; Selin, C.E.; Terao, E.N.

1977-01-01

To determine the variables that might affect interpretability of myocardial perfusion images in patients with acute myocardial infarctions, images obtained following intravenous administration of potassium-43 or cesium-129 were evaluated in 68 patients with nonacute coronary or noncoronary heart diseases, who were undergoing cardiac catheterization. Severe coronary arterial disease usually produces no distinctive perfusion defects in the resting state. Remote infarcts likewise tend to remain undetectable unless accompanied by wall-motion disturbances that can be detected by ventriculography. Left ventricular hypertrophy or cardiac dilatation can produce perfusion patterns indistinguishable from the ischemic defects of infarction. Right ventricular hypertrophy can cause image alterations that mimic infarcts in the left ventricle. In patients with acute myocardial infarction, sequential imaging studies with perfusion indicators should be of value in determining the effects of various therapeutic maneuvers on regional myocardial perfusion, but variations caused by conditions other than acute vascular occlusion limit the usefulness of perfusion imaging for diagnosing acute infarction. In suspected acute infarction, perfusion imaging will be used most effectively in conjunction with other imaging or nonimaging procedures that show the presence of damaged or necrotic myocardium. The information derived from this study should be generally applicable to the interpretation of imaging results obtained with the newer indicators of myocardial perfusion now in use or under development

Guinea Worm in a Frog

Centers for Disease Control (CDC) Podcasts

2017-03-09

Dr. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.  Created: 3/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/9/2017.

Metabolism in the isolated rat heart: comparison of 125I-BMIPP with 125I-IPPA

International Nuclear Information System (INIS)

Chen Shaoliang; Cheng Aiping; Xu Lanwen; Qiao Weiwei

2008-01-01

Objective: The fatty acid metabolism in myocardium is recently one of the most interesting subjects in nuclear cardiology. The purpose of this study was to clarify the metabolic fate of 125 I-labeled 15-(p-iodophenyl)-3-(R, S)-methyl-pentadecanoic acid ( 125 I-BMIPP) and 15-(p-[ 125 I] iodophenyl) pentadecanoic acid ( 125 I-IPPA) by means of isolated rat hearts. Methods: Ten isolated rat hearts were prepared and perfused with 125 I-BMIPP (5 rats) or 125 I-IPPA (5 rats) for 3 h following a basic perfusion of 30 min. After perfusion, the radioactivity in the recirculated buffer was measured. The metabolites in the buffer were then extracted and analyzed using high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Results: At the beginning (5 rain) of 125 I-BMIPP perfusion, the main radioactive peak appeared on HPLC at 37 min, which remained after 3 h perfusion. Several small peaks eluting were found before the parent peak at 30, 26, 21, 16, 12 and 9 min, respectively. At the beginning (5 min) of 125 I-IPPA perfusion, the main peak appeared on HPLC at 33 min, which disappeared after 3 h. Conclusions: 125 I-BMIPP strongly inhibited beta-oxidation, therefore appeared suitable for myocardial metabolic imaging. 125 I-IPPA was metabolized rapidly. (authors)

Positron emission tomography of the heart

International Nuclear Information System (INIS)

Budinger, T.F.; Yano, Y.; Huesman, R.H.; Derenzo, S.E.; Moyer, B.R.; Mathis, C.A.; Ganz, E.; Knittel, B.

1983-01-01

Positron emission tomography (PET) of the heart can measure blood perfusion, metabolism of fatty acids, metabolism of sugars, uptake of amino acids and can quantitate infarction volume. The principles are reviewed which are basic to PET instrumentation and procedures for quantitative studies of human physiology with examples of measurements of myocardial flow and metabolism

Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles.

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S D Biju

Full Text Available Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae, this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.

Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens.

Science.gov (United States)

Hovey, Kyle J; Seiter, Emily M; Johnson, Erin E; Saporito, Ralph A

2018-03-01

Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

BIOMETRIC STUDY TO RANA RIDIBUNDA FROG SPECIES NEARNESS TO TIMISOARA LOCALITY

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M. BURA

2007-10-01

Full Text Available Speciality literature provides little informations regarding Rana ridibunda frogbiometry. For supply this gap we studied the size and weight of 54 frogs sampled fromnearby Timişoara area ponds.The mean body lenght was 8,08 ± 0,54 cm for the females and respectively 6,17 ± 0,45cm for the males. Before evisceration on a par females weighted 62,28 ± 12,87 g andthe males 22,46 ± 5,3 g whereas after this action the carcase weighted 43,89 ± 8,91 gin the case of females and respectively 18,45 ± 4,42 g in the case of male lake frog. Themean leg lenght measured 12,59 ± 0,68 cm for female frogs and 9,78 ± 0,66 cm in thecase of male frogs. The hind stylopodium was estimated on a par as 13,23 ± 2,57 g forfemales and 5,33 ± 1,26 g for the males.

Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

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Ximena E. Bernal

2016-04-01

Full Text Available Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus, a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp., were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%. This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

Hematophagous insects as vectors for frog trypanosomes.

Science.gov (United States)

Ramos, B; Urdaneta-Morales, S

1977-12-01

Experimental infections of three hematophagous arthropods (Rhodnius prolixus, Aedes aegypti, and Culex pipiens) with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A. aegypti is a good host for the flagellate; the course of development in the intestinal tract of the mosquito is described from 15 minutes to 168 hours. C. pipiens showed only low intestinal infections and R. prolixus did not permit development of the parasite. It is postulated that, in addition to the transmission of T. rotatorium by leeches, batrachophilic mosquitoes may transmit the parasite to frogs of more terrestrial habits by being ingested by these anurans.

Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

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Rohit Naniwadekar

2014-08-01

Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

Clinical use of nuclear cardiology in the assessment of heart failure

International Nuclear Information System (INIS)

Han Lei; Shi Hongcheng

2011-01-01

Nuclear cardiology is the most commonly performed non-invasive cardiac imaging test in patients with heart failure, and it plays an important role in their assessment and management. Quantitative gated single positron emission computed tomography is used to assess quantitatively cardiac volume, left ventricular ejection fraction, stroke volume, and cardiac diastolic function. Resting and stress myocardial perfusion imaging can not only identify nonischemic heart failure and ischemic heart failure, but also demonstrate myocardial viability. Diastolic heart failure also termed as heart failure with a preserved left ventricular ejection fraction is readily identified by nuclear cardiology techniques and can accurately be estimated by peak filling rate and time to peak filling rate. With newer techniques such as three-dimensional, quantitative gated single positron emission computed tomography can assess movement of the left ventricle, and wall thickening evaluation aids its assessment. Myocardial perfusion imaging is also commonly used to identify candidates for implantable cardiac defibrillator and cardiac resynchronization therapies. Neurotransmitter imaging using 123 I-metaiodobenzylguanidine offers prognostic information in patients with heart failure. Metabolism and function in the heart are closely related, and energy substrate metabolism is a potential target of medical therapies to improve cardiac function in patients with heart failure. Cardiac metabolic imaging using 123 I-15-(p-iodophenyl) 3-R, S-methylpentadecacoic acid is a commonly used tracer in clinical studies to diagnose metabolic heart failure. Nuclear cardiology tests, including neurotransmitter imaging and metabolic imaging, are now easily preformed with new tracers to improve heart failure diagnosis. Nuclear cardiology techniques contribute significantly to identifying patients with heart failure and to guiding their management decisions. (authors)

Autonomic Function Impairment and Brain Perfusion Deficit in Parkinson’s Disease

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Wei-Che Lin

2017-06-01

Full Text Available IntroductionAutonomic disorders have been recognized as important Parkinson’s disease (PD components. Some vulnerable structures are related to the central autonomic network and have also been linked to autonomic function alterations. The aims of the study are to evaluate the severity of the autonomic dysfunction and the cortical hypoperfusion using arterial spin labeling (ASL MRI. And then, possible relationships of significant between-group differences in perfusion pattern to clinical variables and autonomic functions were examined to determine the pharmaceutical effects of dopaminergic treatment on cerebral blood flow (CBF in patients with PD.MethodsBrain ASL MRI was carried out in 20 patients with PD (6 men and 14 women, mean age: 63.3 ± 6.4 years and 22 sex- and age-matched healthy volunteers to assess whole-brain CBF and the effects of dopaminergic therapy on perfusion. All subjects underwent a standardized evaluation of cardiovagal and adrenergic function including a deep breathing, Valsalva maneuver, and 5-min head-up tilt test. Perfusion MRI data were acquired on a 3.0 T scanner with a pulsed continuous ASL technique. The CBF, autonomic parameters, and clinical data were analyzed after adjusting for age and sex.ResultsPatients exhibited a decline in autonomic function (rapid heart rate in response to deep breathing, low baroreflex sensitivity, high systolic and diastolic pressure, and altered tilting test response, widespread low CBF, and robust response to dopaminergic therapy. Lower perfusion in the middle frontal gyrus was associated with increased clinical disease severity (Unified Parkinson’s Disease Rating Scale I score, P < 0.001. Lower perfusion in autonomic control areas, such as the frontal lobe and insula, were significantly associated with autonomic impairment (P < 0.001.ConclusionsOur study indicates that PD is a progressive neurodegenerative disorder that changes the perfusion of central nervous system

Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

Science.gov (United States)

Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

2012-04-01

Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

Nuclear cardiology. I - Radionuclide angiographic assessment of left ventricular contraction: uses, limitations and future directions. II - The role of myocardial perfusion imaging using thallium-201 in diagnosis of coronary heart disease

International Nuclear Information System (INIS)

Bodenheimer, M.M.; Banka, V.S.; Helfant, R.H.; Pennsylvania, University, Philadelphia, PA)

1980-01-01

The current status of radionuclide angiography is reviewed. First pass and gated equilibrium methods for determining left ventricular contraction are compared. Some clinical applications of radionuclide angiography are then examined, including the detection of discrete versus diffuse asynergy and the assessment of myocardial infarction. The second part of this work reviews the uses and limitations of thallium-201 perfusion imaging in the diagnosis of the acute and chronic manifestations of coronary heart disease. Theoretical and technical considerations of thallium-201 imaging are reviewed along with the clinical implications of the technique

Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

International Nuclear Information System (INIS)

Boll, Daniel T.; Lewin, Jonathan S.; Young, Philip; Gilkeson, Robert C.; Siwik, Ernest S.

2005-01-01

The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries. (orig.)

First report of Hepatozoon sp. in the Oregon spotted frog, Rana pretiosa.

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Stenberg, Patricia L; Bowerman, William J

2010-07-01

From 2005 through 2008, we screened 650 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon, USA, for hemoparasites. A Hepatozoon sp., not previously reported in R. pretiosa, was found in one population of frogs, mostly as intracellular gamonts at a prevalence of 10.5% with parasitemias ranging from 0.02% to greater than 42% of erythrocytes within individual frogs. Intra-and extracellular merozoites were present, but rare. A potential vector, the mosquito Culex boharti, was common throughout the habitat of the population carrying Hepatozoon sp.

Bacterial flora on Cascades frogs in the Klamath Mountains of California

Science.gov (United States)

Karen Pope

2013-01-01

Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

Salmonella Infection and Water Frogs

Centers for Disease Control (CDC) Podcasts

2010-01-12

This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

Natural disturbance reduces disease risk in endangered rainforest frog populations.

Science.gov (United States)

Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

2015-08-21

Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11-28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

Eleutherodactylus frog introductions to Hawaii

Science.gov (United States)

Kraus, Fred; Campbell, Earl W.; Allison, Allen; Pratt, Thane K.

1999-01-01

As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately 1500 years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half (McKeown 1996). The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers (Gibbons 1985; Dye and Steadman 1990), In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional. Several frog species were released for biocontrol of insects (e.g., Dendrobates auratus, Bufo marinus, Rana rugosa, Bryan 1932; Oliver and Shaw 1953), and most of the remaining species are released or escaped pets (e.g., Phelsuma spp., Chamaeleo jacksonii, Iguana iguana, McKeown 1996), Government-approved releases have not occurred for many years, but the rate of establishment of new species has increased in the past few decades because of the importation and subsequent release of pets.

Study of a new method for the evaluation of portal vein pressure by hepatic perfusion imaging

International Nuclear Information System (INIS)

Cheng Muhua; Ling Yunbiao; Pan Zhiheng; Zhang Feng; Chen Weizhen

2002-01-01

To study a new method for predication of portal vein pressure (PVP) by hepatic perfusion imaging. 25 hepato-cirrhotic cases and 13 normal controls were performed the hepatic perfusion imaging. According to two compartmental model the values of portal vein indexes (PVI) was calculated using curve slope, area and hepatic heart perfusion ratio methods etc. The relationship of PVI with different method to PVP was also observed. All PVI by three methods in hepatocirrhosis were higher than those in normal controls (P<0.01), and also positively correlated with the PVP, their correlated coefficients was 0.79, 0.60, 0.68 respectively. Among them the slope method was most markedly significant than normal control and closely correlated with PVP. PVI can sensitively reflect the changes of portal vein blood flow. And it was an atraumatic, simple method for the evaluation of PVP

Quantification of the effect of water exchange in dynamic contrast MRI perfusion measurements in the brain and heart

DEFF Research Database (Denmark)

Larsson, H B; Rosenbaum, S; Fritz-Hansen, T

2001-01-01

Measurement of myocardial and brain perfusion when using exogenous contrast agents (CAs) such as gadolinium-DTPA (Gd-DTPA) and MRI is affected by the diffusion of water between compartments. This water exchange may have an impact on signal enhancement, or, equivalently, on the longitudinal...... exchange can have a significant effect on perfusion estimation (F) in the brain when using Gd-DTPA, where it acts as an intravascular contrast agent....

Dry-season retreat and dietary shift of the dart-poison frog Dendrobates tinctorius (Anura: Dendrobatidae

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Marga Born

2010-07-01

Full Text Available Seasonal rainfall affects tropical forest dynamics and behaviorof species that are part of these ecosystems. The positive correlation between amphibian activity patterns and rainfall has been demonstrated repeatedly. Members of Dendrobatidae, a clade of Neotropical dart-poison frogs, are well known for their habitat use and behavior during the rainy season, but their behavior during the dry season has received little attention. We studied habitat use and diet of the dendrobatid frog Dendrobates tinctorius in French Guiana during the rainy and dry seasons. Unlike many other dendrobatid frogs, D. tinctorius does not maintain territories for the entire rainy season. Both sexes colonize recently formed canopy-gaps and stay in these forest patches for only a few weeks. The frogs inthese patches consume a great diversity of prey, consisting of ants, beetles, wasps, insect larvae, and mites. During the dry season, frogs move to retreat sites in mature forest, such as palm bracts and tree holes. The frogs are less active and consume fewer prey items in the dry season, and they consume fewer wasps and insect larvae, but more termites. Ants are the most common prey items during both the wet and dry seasons. We discuss the effects of shifts in seasonal habitat use on the territorial behavior of dendrobatid frogs.

Synthesis of no carrier added F-18 16-fluorohexadecanoic acid (FHDA) and investigation of its labeled metabolites and its kinetics in the heart

International Nuclear Information System (INIS)

DeGrado, T.R.; Bernstein, D.R.; Gatley, S.J.; Ng, C.K.; Holden, J.E.

1984-01-01

No carrier added FHDA was prepared via saponification of the product of silver oxide assisted reaction of near-anhydrous tetraethylammonium fluoride with methyl 16-iodohexadecanoate. The labeled fatty acid was injected into isolated perfused rat hearts. Coronary perfusate was collected for 4-9 minutes, when hearts were chilled and homogenized. F-18 in perfusate was analysed by HPLC (NH column; 50mM amm. acetate in 50% acetonitrile). Material with the same retention time as F-18 fluoroacetate (prepared by F-for-I exchange with ethyl iodoacetate) was found. Some F-18 stuck permanently to the column and was assigned as fluoride since the same fraction of label in perfusate was retained on alumina columns eluted with water. Anion exchange HPLC (SAX column; 20mM pot. phosphate, pH 7) of homogenates gave peaks corresponding to fluoroacetate plus fluoride and minor peaks which could be fluoroacetylCoA and fluorocitrate. The authors interpret their data as follows. Beta-oxidation of FHDA results in fluoroacetylCoA which either undergoes ''lethal synthesis'' to fluorocitrate or is hydrolysed to fluoroacetate which diffuses out of the heart. The source of the fluoride is not yet clear, but could complicate interpretation of FHDA kinetics measured in vivo with positron tomography. Clearance of label from FHDA in isolated perfused hearts was faster than for labeled 16-iodohexadecanoic acid, indicating that the F-18 tracer may be a more sensitive probe of myocardial fatty acid metabolism

Archaeobatrachian paraphyly and pangaean diversification of crown-group frogs.

Science.gov (United States)

Roelants, Kim; Bossuyt, Franky

2005-02-01

Current models for the early diversification of living frogs inferred from morphological, ontogenetic, or DNA sequence data invoke very different scenarios of character evolution and biogeography. To explore central controversies on the phylogeny of Anura, we analyzed nearly 4000 base pairs of mitochondrial and nuclear DNA for the major frog lineages. Likelihood-based analyses of this data set are congruent with morphological evidence in supporting a paraphyletic arrangement of archaeobatrachian frogs, with an (Ascaphus + Leiopelma) clade as the sister-group of all other living anurans. The stability of this outcome is reinforced by screening for phylogenetic bias resulting from site-specific rate variation, homoplasy, or the obligatory use of distantly related outgroups. Twenty-one alternative branching and rooting hypotheses were evaluated using a nonparametric multicomparison test and parametric bootstrapping. Relaxed molecular clock estimates situate the emergence of crown-group anurans in the Triassic, approximately 55 million years prior to their first appearance in the fossil record. The existence of at least four extant frog lineages on the supercontinent Pangaea before its breakup gains support from the estimation that three early splits between Laurasia- and Gondwana-associated families coincide with the initial rifting of these landmasses. This observation outlines the potential significance of this breakup event in the formation of separate Mesozoic faunal assemblages in both hemispheres.

Regulation of ribonucleic acid synthesis by polyamines. Reversal by spermine of inhibition by methylglyoxal bis(guanylhydrazone) of ribonucleic acid synthesis and histone acetylation in rabbit heart.

Science.gov (United States)

Caldarera, C M; Casti, A; Guarnier, C; Moruzzi, G

1975-10-01

The relationship between polyamines and RNA synthesis was studied by considering the action of spermine on histone acetylation in perfused heart. In addition, the effect of methylglyoxal bis(guanylhydrazone), inhibitor of putrescine-activated S-adenosylmethionine decarboxylase activity, on RNA and polyamine specific radioactivity and on acetylation of histone fractions was also investigated in perfused heart. Different concentrations of spermine and/or methylglyoxas bis(guanylhydrazone) were injected into the heart, 15 min after beginning the perfusion. The results demonstrate that spermine stimulates the specific radioactivity of RNA of subcellular fractions. Acetylation of the arginine-rich histone fractions, involved in the regulation of RNA transcription, is enhanced by spermine. The perfusion with methylglyoxal bis(guanylhydrazone) causes a decrease in the specific radioactivity of polyamines and RNA, and in acetylation of histone fractions. However, spermine is able to reverse the methylglyoxal bis(guanylhydrazone) inhibition when injected simultaneously. From these results we may assume a possible role for spermine in the regulation of RNA transcription.

[Myocardial perfusion imaging by digital subtraction angiography].

Science.gov (United States)

Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

1986-03-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Semaphoring in an earless frog: the origin of a novel visual signal.

Science.gov (United States)

Lindquist, E D; Hetherington, T E

1998-10-01

Social communication in anuran amphibians (frogs and toads) is mediated predominantly by acoustic signals. Unlike most anurans, the Panamanian golden frog, Atelopus zeteki, lacks a standard tympanic middle ear and appears to have augmented its communicatory repertoire to include rotational limb motions as visual signals, referred to here as semaphores. The communicatory nature of semaphoring was inferred from experimental manipulations using mirrored self-image presentations and nonresident introductions. Male frogs semaphored significantly more when presented with a mirrored self-image than with a nonreflective control. Novel encounters between resident males and nonresident frogs demonstrated that semaphores were used directionally and were displayed toward target individuals. Females semaphored frequently and this observation represents a rare case of signaling by females in a typically male-biased communicatory regime. Semaphore actions were clearly linked to a locomotory gait pattern and appear to have originated as an elaboration of a standard stepping motion.

Using a pulse oximeter to determine clinical depth of anesthesia-investigation of the utility of the perfusion index.

Science.gov (United States)

Krishnamohan, Anirudh; Siriwardana, Viraj; Skowno, Justin J

2016-11-01

Peripheral vasodilation is a well-recognized side effect of general anesthesia, and induces changes in the amplitude of the pulse plethysmograph (PPG) waveform. This can be continuously quantitaed using the Perfusion Index (PI), a ratio of the pulsatile to nonpulsatile signal amplitude in the PPG waveform. We hypothesized that the perfusion index would rise with the induction of anesthesia in children, and fall with emergence, and performed a prospective, observational study to test this. Our primary aim was to test whether the different clinical stages of anesthesia were associated with changes in the perfusion index, and the secondary aim was to test the correlation between the normalized perfusion index and the MAC value. Twenty-one patients between the ages of 1 and 18 undergoing minor procedures with no anticipated painful stimuli were recruited. Patients with significant illnesses were excluded. Data collection commenced with a preinduction baseline, and data were collected continuously, with event marking, until completion of the anesthesia and removal of the pulse oximeter. Data collected included perfusion index, heart rate, and anesthetic gas concentration values. A normalized perfusion index was calculated by subtracting the initial baseline perfusion index value from all perfusion index values, allowing changes, from a standardized initial baseline value of zero, to be analyzed. During induction, the mean normalized perfusion index rose from 0.0 to 4.2, and then declined to 0.470 when the patients returned to consciousness. P < 0.001 using repeated measures anova test. The normalized perfusion index was correlated with MAC values (r 2 = 0.33, 95% CI 0.18-0.47, P < 0.01). The perfusion index changed significantly during different stages of anesthesia. There is a significant correlation between the perfusion index, measured by pulse oximetry, and the MAC value, in pediatric patients undergoing minor procedures. © 2016 John Wiley & Sons Ltd.

Near infrared spectroscopy for controlling the quality of distal leg perfusion in remote access cardiopulmonary bypass.

Science.gov (United States)

Schachner, Thomas; Bonaros, Nikolaos; Bonatti, Johannes; Kolbitsch, Christian

2008-12-01

The prevention of leg ischemia is necessary in all patients undergoing femoral artery cannulation for extracorporeal circulation. Near infrared spectroscopy (NIRS) is an established non-invasive method for measuring tissue oxygen saturation. Ten patients underwent robotically assisted endoscopic coronary surgery or ASD repair on the arrested heart using aortic endo-occlusion catheters. They were monitored by transcutaneous NIRS (placed on both lower legs) for quality control of distal leg perfusion during femoral access cardiopulmonary bypass. The baseline NIRS values were 61 (52-80) on the cannulated side versus 70 (53-80) on the contralateral leg (p=n.s.). During clamping of the femoral artery for installation of the remote access perfusion system the tissue oxygen saturation dropped to 38 (18-58) (p=0.001 vs baseline) while it remained stable on the contralateral leg. After successful implantation of the distal leg perfusion the NIRS values normalized to similar amounts on both legs. We conclude that transcutaneous NIRS of the lower legs might be a useful non-invasive tool for monitoring leg perfusion in patients undergoing extracorporeal circulation via the femoral vessels.

Characteristics of myocardial perfusion imaging and coronary artery angiography in patients of NIDDM complicated with AMI

International Nuclear Information System (INIS)

Zhao Peiqin; Zhao Jinhua; Qin Mingzhao; Dai HaoJie; Zhang Runwu; Xiao Fen

2001-01-01

Objective: To investigate the characteristic changes of myocardial perfusion imaging and coronary artery angiography in patients of acute myocardial infarction (AMI) with underlined type 2 diabetes mellitus. Methods: 25 type 2 diabetes mellitus patients were enrolled for having clinical manifestation of AMI. Ten inpatients with AMI of simple coronary heart disease origin were served as controls. All subjects underwent both myocardial perfusion imagings (resting and nitroglycerine invention) and coronary artery angiography. Results: Compared to controls (40%), type 2 diabetes mellitus + AMI group had higher rate of multivessel disease (60%). For type 2 diabetes mellitus + AMI patients, 129/400 segments (32.25%) showed fixed defect, 25/160 segments (15.62%) in controls. Conclusions: For type 2 diabetes mellitus + AMI group, myocardial perfusion defects are widely distributed and multivessel or severe stenosis is more often presented. Good correlation exists between abnormal segments and angiographic lesions in both the number of segments involved and the severity of the lesions. Radionuclide myocardial perfusion is therefore considered a useful screening test not inferior to angiography, especially for those who are not tolerant enough to undergoing angiography

Assessment of the myocardial perfusion pattern in patients with multivessel coronary artery disease

International Nuclear Information System (INIS)

Iskandrian, A.S.; Hakki, A.H.; Segal, B.L.; Kane, S.A.; Amenta, A.

1983-01-01

A total of 42 symptomatic patients with coronary artery disease involving two or three vessels were studied using exercise thallium-201 myocardial scintigraphy. Qualitative analysis of the images predicted multivessel disease in 75% of the patients with two-vessel disease and in 82% of the patients with three-vessel disease. Quantitative analysis of the size of the perfusion defect indicated that approximately 40% of the left ventricular perimeter showed abnormal perfusion pattern during stress in these patients, and there was no significant difference in the size of the defect in patients with two-vessel disease or three-vessel disease (41 +/- 17% vs 42 +/- 14%, respectively, mean +/- SD). The exercise heart rate, exercise ECG response, and severity of narrowing did not correlate with the size of the perfusion defect. Patients with anterior infarction had larger defects in the distribution of the left anterior descending artery than those without infarction. Collaterals offered partial protection during exercise only when they were not jeopardized. This study confirms the value of qualitative analysis of exercise thallium-201 imaging in predicting multivessel disease, and describes a simple method of assessing the extent of perfusion abnormalities during stress in patients with multivessel disease. The results may be important in patient management and prognosis

Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa.

Science.gov (United States)

Netherlands, Edward C; Cook, Courtney A; Kruger, Donnavan J D; du Preez, Louis H; Smit, Nico J

2015-04-01

Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

Laser doppler perfusion imaging

International Nuclear Information System (INIS)

Waardell, K.

1992-01-01

Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

Diagnostic value of stress-rest myocardial perfusion imaging in detection of coronary disease in elderly patients

International Nuclear Information System (INIS)

Han Pingping; Tian Yueqin; Fang Wei; Shen Rui; Yang Minfu; Wei Hongxing; Guo Xinhua; He Zuoxiang

2009-01-01

Objective: Coronary artery disease is one of the most common causes of death in elderly people. Yet, definite diagnosis is a dilemma due to the variety of symptoms and signs. The aim of this study was to evaluate the diagnostic value of nuclear stress-rest myocardial perfusion imaging(MPI) in detection of coronary disease in the elderly. Methods: Two hundred and five elderly subjects (≥60 years old, average of 67 ± 5) who were suspected to have coronary disease, underwent both stress-rest myocardial perfusion imaging (185 with exercise stress and 20 with adenosine stress) and coronary angiography (CAG). All had no pereutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Coronary angiography was used as a 'golden standard' to evaluate the sensitivity, specificity and accuracy of the stress-rest myocardial perfusion imaging. χ 2 -test was used in data analysis with SPSS 15.0. Results: Among 205 patients. there were 57 patients with an abnormal CAG result and 148 patients with a normal result. Of the 57 patients, there were 30 one-, 19 two-, and 8 three-vessel stenosis. Fifteen were mild-, 17 were moderate-, 17 were severe stenosis, and 8 were totally occluded.About 63% (36/57) had positive stress-rest MPI. Of the 148 subjects who had a normal CAG, 135 had negative MPL. The sensitivity.specificity and accuracy of stress MPI were 63% (36/57), 91% (135/148) and 83% (171/205) in patient level.respectively. The di-agnostic sensitivities of stress-rest MPI for detection of one-, two-, and three-vessel stenosis were 57%(17/30), 58% (11/19) and 8/8, respectively. All 185 patients who underwent exemise stress MPI were divided into 2 groups according to whether the patients reached the target heart rate or not at the peak of the test. And 53 patients (29%) were group 1 (reached the target heart rate)and 132 patients (71%) were group 2 (did not reach the target heart rate). The sensitivity of group 1 wag higher than that of group 2, but with no

Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

DEFF Research Database (Denmark)

Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

1995-01-01

Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

Sexual differences in prevalence of a new species of trypanosome infecting t?ngara frogs

OpenAIRE

Bernal, Ximena E.; Pinto, C. Miguel

2016-01-01

Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypa...

Pharmacological characterization of Tc-99m(CN-t-butyl)/sub 6//sup +/: A potential heart agent

International Nuclear Information System (INIS)

Pendleton, D.B.; Delano, M.L.; Sands, H.; Gallagher, B.M.; Liteplo, M.P.; Camin, L.L.; Subramanyam, V.

1984-01-01

The authors have investigated the pharmacological behavior of hexakis (t-butylisonitrile)Tc(I) and evaluated it as a potential myocardial perfusion radiopharmaceutical. This complex produces good to excellent heart images in rats, guinea pigs, rabbits, cats, dogs, pigs and baboons. Good heart uptake in guinea pigs, cats and pigs may be predictive of good myocardial imaging in man, since the hearts of these three species extract Tl-201, but not Tc-99m(dmpe)/sub 2/-Cl/sub 2//sup +/ (similar to man, but unlike other animal species). Biodistribution studies reveal initial heart uptake of 1.3 to 2.2% of the injected activity. Imaging and biodistribution show significant initial lung activity which clears substantially during the first hour after injection. Little or no myocardial washout is observed. In rabbits with ischemia induced by coronary artery ligation, the complex distributes as a function of blood flow. Simultaneous injection of Tl-201 and Tc-99m (CN-t-butyl)/sub 6//sup +/ with subsequent dual isotope imaging shows that their initial distribution is a similar. The complex is extracted 100% by isolated rabbit and guinea pig hearts perfused with buffer. When human blood is mixed and co-injected with the complex, myocardial extraction is reduced, but remains high (73-75%). Uptake of the complex by rat myocytes in culture is not inhibited by either ouabain or K/sup +/. These results suggest that this complex may be a promising myocardial perfusion agent and should be tested in man

The effect of relaxing music on heart rate and heart rate variability during ECG GATED-myocardial perfusion scintigraphy.

Science.gov (United States)

Tan, Yusuf Ziya; Ozdemir, Semra; Temiz, Ahmet; Celik, Fatmanur

2015-05-01

The positive changes in human behavior caused by relaxing music demonstrate the psychological effect of music on human body. A meta-analytical study has shown that relaxing music affects blood pressure and heart rate in coronary heart patients and cancer patients. The aim of our study is to research whether there is a significant effect on heart rate and heart rate variability due to listening to relaxing music during ECG GATED MPS imaging under gamma camera. The music group (n = 50 patients) could choose from 15 different musical types including folk music (no lyric). The other 50 patients were placed in a "no music group" and did not get headphones or any music. There was a statistically significant reduction in the heart rate of patients in the music group compared to those in the control group. Relaxing music provides great benefits to both patient and clinician. There is close relationship between relaxing music and health procedure, can use every area of the health noninvasiv, safe, cheap and is a method don't have side effect. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lung perfusion scintigraphy in the diagnosis of peripheral pulmonary stenosis in patients after repair of Fallot tetralogy

International Nuclear Information System (INIS)

Sabiniewicz, R.; Chojnicki, M.; Alszewicz-Baranowska, J.; Erecinski, J.; Romanowicz, G.; Lass, P.; Bandurski, T.

2002-01-01

The frequency of peripheral pulmonary artery stenosis in patients after surgical repair of tetralogy of Fallot (TOF) ranges from 20 to 40%. This can be either primary or secondary to the surgical intervention. The influence of resulting lung perfusion alterations on the life quality of patients is difficult to predict. The aim of this study was to compare the utility of the diagnostic procedures in this group of patients, with particular focus on lung perfusion scintigraphy. This study comprised 104 patients who underwent repair of TOF at ages from 5 months to 25 years. The patients have been followed up for from 4.2 to 25 years. On the basis of chest X-ray peripheral pulmonary artery stenosis was suspected in 11 patients, in 12 on the basis of echocardiography examination. Lung perfusion scintigraphy has been performed on 87 patients. The disturbances in lung perfusion (mostly in the left lung) were show by means of lung perfusion scintigraphy in 43 (49%) of patients. In 27 of them heart catheterisation has been performed. Angiography revealed stenosis of the lung artery branch in 15/43 (34.9%) patients with abnormal perfusion lung scan and in 4/44 (9%) in patients with normal perfusion lung scan. Intervention procedures were carried out on 10 patients. Lung perfusion scintigraphy may prove a valuable, non-invasive screening tool in the assessment of patients after TOF repair, although both false-negative and false positive results may happen. Therefore, it should play an auxiliary role together with other diagnostic modalities. (author)

Detecting fish parvalbumin with commercial mouse monoclonal anti-frog parvalbumin IgG.

Science.gov (United States)

Chen, Lingyun; Hefle, Sue L; Taylor, Steve L; Swoboda, Ines; Goodman, Richard E

2006-07-26

Parvalbumin is a calcium-binding muscle protein that is highly conserved across fish species and amphibians. It is the major cross-reactive allergen associated with both fish and frog allergy. We used two-dimensional electrophoretic and immunoblotting techniques to investigate the utility of a commercial monoclonal anti-frog parvalbumin IgG for detecting parvalbumin present in some commonly consumed fish species. The 2D electrophoresis and immunoblots revealed species-specific differences in proteins that appear to represent various numbers of isoforms of parvalbumin in carp (5), catfish (3), cod (1) and tilapia (2). No parvalbumin was detected in yellowfin tuna. Based on minor differences in relative intensities of protein staining and immunodetection, parvalbumin isoforms may have slight differences in the epitope region recognized by the anti-frog parvalbumin antibody. These results suggest that the frog anti-parvalbumin antibody can be used as a valuable tool to detect parvalbumins from the fish tested in this study, except yellowfin tuna.

Transcapillary permeability and subendothelial distribution of endothelial and amniotic fluid insulin-like growth factor binding proteins in the rat heart

International Nuclear Information System (INIS)

Bar, R.S.; Clemmons, D.R.; Boes, M.; Busby, W.H.; Booth, B.A.; Dake, B.L.; Sandra, A.

1990-01-01

Insulin-like growth factor (IGF) binding proteins (IGFBP) were purified from conditioned media of cultured bovine endothelial cells (ECBP) and from human amniotic fluid (IGFBP-1), and then labeled by radioiodination. 125I-ECBP and 125I-IGFBP-1 were perfused through isolated beating rat hearts for 1 and 5 min, and the hearts fixed and analyzed for 125I-BP content and distribution. One to 4% of the perfused 125I-ECBP and 125I-IGFBP-1 crossed the capillary boundary. The ECBPs predominantly localized as intact 125I-BP in connective tissue elements of the heart with less 125I-BP in cardiac muscle. The ratio of 125I-ECBP in connective tissue: muscle (normalized to percent vol of these compartments) was greater than or equal to 10:1. In contrast, the IGFBP-1 had a greater affinity for cardiac muscle with ratios of 125I-IGFBP-1 in connective tissue:muscle of approximately 1:2. When 125I-IGF-I, in the absence of any BPs, was perfused through the hearts approximately 3-5% left the microcirculation and was found in subendothelial tissues. 125I-IGF-I localized primarily to cardiac muscle with a distribution of connective tissue:cardiac muscle of about 1:3. The findings in the isolated perfused heart were confirmed in intact animals. After 125I-IGFBP-1 was injected into anesthetized rats and allowed to circulate for 5 min, substantial radioactivity was associated with the heart. As in the isolated heart, the IGFBP-1 preferentially localized to cardiac muscle with a connective tissue:cardiac muscle ratio of 1:3. We conclude that IGFBPs produced by endothelial cells and the IGFBP-1 contained in amniotic fluid can cross the capillary boundaries of the rat heart, and that the ECBPs preferentially localize in connective tissue elements of the myocardium, whereas IGFBP-1 predominantly localizes in cardiac muscle

Electromechanical effects of bepridil on rabbit isolated hearts.

OpenAIRE

Anno, T.; Furuta, T.; Itoh, M.; Kodama, I.; Toyama, J.; Yamada, K.

1984-01-01

Electromechanical effects of a new antianginal agent, bepridil, on Langendorff-perfused rabbit hearts were compared with those of verapamil and lidocaine. Bepridil at concentrations above 2 X 10(-7)M caused a dose-related decrease in heart rate (HR), a prolongation of the atrio-His bundle conduction time (A-H interval) and a prolongation of the functional refractory period (FRP) of the atrioventricular (A-V) node. Similar changes in HR, A-H interval and the FRP of the A-V node were observed w...

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.

Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

Science.gov (United States)

Stephen F. Hale; Philip C. Rosen; James L. Jarchow; Gregory A. Bradley

2005-01-01

We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and...

Comparison of adenosine and exercise stress 201Tl myocardial perfusion imaging for diagnosing coronary heart disease in women

International Nuclear Information System (INIS)

Li Jiangjin; Ma Shuren; Meng Tao; Bao Zhi; Cui Jianhe

2011-01-01

Objective: To compare the diagnostic value of adenosine and exercise stress myocardial perfusion imaging (MPI) for detecting coronary heart disease (CHD) in women. Methods: One hundred and thirty-eight patients with CHD were randomly divided into two groups: adenosine stress group (n=69)and exercise stress group (n=69). All patients underwent myocardial SPECT evaluation. Coronary angiography (CAG), referred as 'gold standard' , was performed in each patient within 1 week before or after MPI. The diagnostic value of the two stress MPI was compared with χ 2 test or Fisher's exact test. Results: In adenosine stress group, the sensitivity, negative predictive value and accuracy were 88.2% (45/51), 72.7% (16/22), 88.4% (61/69), respectively, which were not significantly different from those of the exercise stress group (91.7% (44/48), 66.7% (8/12), 81.2% (52/64); χ 2 =0.571, 0.714, 0.249, P>0.05). However, the false positive rate of adenosine stress (11.1%, 2/18) was significantly lower than that of exercise stress (50.0%, 8/16), P=0.023. Conclusions: Adenosine and exercise stress MPI have similar value for CHD diagnosis in women, however, adenosine stress MPI may have an advantage of low false positive rate. (authors)

Dietary alkaloid sequestration in a poison frog: an experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae).

Science.gov (United States)

Hantak, Maggie M; Grant, Taran; Reinsch, Sherri; McGinnity, Dale; Loring, Marjorie; Toyooka, Naoki; Saporito, Ralph A

2013-12-01

Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained alkaloids, whereas those of all control frogs lacked alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary

Evaluation of Tl-201 lung uptake and impairment of pulmonary perfusion on scintigraphies in pulmonary tuberculosis

International Nuclear Information System (INIS)

Fujii, Tadashige; Tanaka, Masao; Koizumi, Tomonori; Kubo, Keishi

2000-01-01

Tl-201 lung uptake in 74 patients (85 lesions) and pulmonary perfusion in 105 patients were studied to evaluate clinical usefulness of Tl-201 lung uptake and perfusion lung scintigraphy in pulmonary tuberculosis, using a scintillation camera with a mini-computer system. As indices of Tl-201 lung uptake, lung (lesion) to upper mediastinum uptake ratio (L/M) and visual grading were used. L/M in pulmonary tuberculosis was 1.96±0.66, which was significantly larger than 1.04±0.24 in healthy controls and lower than that in heart diseases with left heart failure and idiopathic interstitial pneumonia, and showed no significant differences with that in acute pneumonia, pyothorax, primary lung cancer and malignant mediastinal tumor. L/M in pulmonary tuberculosis did not correlate with CRP, erythrocyte sedimentation rate, Gaffky number of sputum and body temperature. It correlated with the type of pulmonary tuberculosis according to the Gakken Classification reflecting the disease activity. It was larger in the exudative type, caseo-infiltrative one, disseminated one, one with cavity in infiltrative lesion than the fibro-caseous one. On perfusion lung scintigram, impairment of pulmonary perfusion larger than area of the entire unilateral lung was observed in 68 cases (64.8%). Area of hypoperfused lung field, which correlated with % vital capacity (r=0.60, p=0.0002) and PaO 2 (r=0.39,p=0.0024), was significantly larger in patients with silicosis and those with bilateral pleural involvements such as pleural callosity than in those with type III according to the Gakkai Classification. Most of the patients showed decreased pulmonary perfusion and Tl-201 accumulation of which grade reflects the disease activity in active tuberculous lesion. Patients with miliary tuberculosis and those with silicotuberculosis showed diffuse Tl-201 accumulation in the both lungs. Tl-201 lung scintigraphy seems to be useful for visualizing active tuberculous lesions, particularly the ones that

Abnormal ankle brachial indices may predict cardiovascular disease among diabetic patients without known heart disease.

Science.gov (United States)

Fine, Jeffrey J; Hopkins, Christie B; Hall, Patrick Ax

2005-07-01

Cardiovascular disease remains the primary cause of diabetes-associated morbidity and mortality. Previous studies have failed to provide accurate, inexpensive, screening techniques to detect cardiovascular disease in diabetics. Ankle brachial indices (ABI) testing may be an effective screening technique for diabetics. The aim of this 100-subject clinical study was to determine cardiovascular disease prevalence, via perfusion stress testing, in diabetic patients having abnormal ABI (<0.90) and without known heart disease who were referred to the South Carolina Heart Center, Columbia, SC for nuclear perfusion stress testing. Study data were analyzed using frequency and descriptive statistics and 2-sample T-testing. Mean subject age was 62+/-11 years, ABI 0.76+/-13, and ejection fraction 60+/-12%. Perfusion stress testing detected 49 abnormal electrocardiograms, 36 subjects with coronary ischemia, 20 with diminished left ventricular function, and 26 subjects having significant thinning of the myocardium. There were 71 subjects who tested positive for at least one form of cardiovascular disease. The sole predictive variable reaching significance for the presence of cardiovascular disease was an ABI score <0.90 (p< or =0.0001). Cardiovascular disease may be predicted among diabetic patients via ABI scores and confirmed by nuclear perfusion testing.

Differentiation of frog fats from vegetable and marine oils by Fourier Transform Infrared Spectroscopy and chemometric analysis

Directory of Open Access Journals (Sweden)

A. N. Nina Naquiah

2015-01-01

Full Text Available The agro-based production and consumption of frogs coupled with world-wide trading have been increased in the recent years giving rise to the risk of frog fat adulteration in expensive vegetable and marine oils. For the first time, we profiled here frog fats using Fourier Transform Infrared (FTIR Spectroscopy coupled with multivariate principal component analysis (PCA. The comparison of the FTIR spectral absorbance intensities demonstrated linkage of frog fats to other edible fats and oils. Three commercially available marine oils and three vegetables oils were studied with frog fats and clear pattern of clusters with distinctive identifiable features were obtained through PCA modeling. PCA analysis identified 2922.21 cm-1, 2852.88 cm-1, 1745.45 cm-1, 1158.29 cm-1 and 721.51 cm-1 FTIR-frequencies as the most discriminating variables influencing the group separation into different clusters. This fundamental study has clear implications in the identification of frog fat from its marine and vegetable counterparts for the potential detection of frog fat adulteration in various fat and oils.

Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

Directory of Open Access Journals (Sweden)

Edward C. Netherlands

2015-04-01

Full Text Available Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01 in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively. Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

Evaluation of use of tiletamine/zolazepam for anesthesia of bullfrogs and leopard frogs.

Science.gov (United States)

Letcher, J; Durante, R

1995-07-01

Use of tiletamine hydrochloride and zolazepam hydrochloride (1:1 fixed ratio combination) as an anesthetic agent in 2 anuran species was studied. A dosage of 5 mg/kg of body weight, administered IM, resulted in variable weak tranquilization. Intramuscular administration at dosages of 10 and 20 mg/kg induced variable states of tranquilization or anesthesia in leopard frogs (Rana pipiens) and bullfrogs (R catesbeiana). The dosages of 50 mg/kg induced anesthesia with greater consistency than lower dosages in bullfrogs, but resulted in mortalities. The same dosage was uniformly fatal in leopard frogs. Neither gross nor histologic lesions were identified in the frogs that died. Depth and duration of anesthesia was dosage related. At the 20 and 50 mg/kg dosages, leopard frogs attained a greater depth of anesthesia and remained anesthetized for a significantly greater duration than did bullfrogs; however, at the 5 and 10 mg/kg dosages, bullfrogs developed greater tranquilization for longer periods than did leopard frogs. Results of this study revealed profound intraspecies variation in depth and duration of effect of tiletamine/zolazepam; therefore, the drug does not appear to be a suitable injectable anesthetic in anurans.

Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

International Nuclear Information System (INIS)

Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae

2005-01-01

Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 ± 8.5%, range:3 ∼ 35%) and mild to moderate severity (-71 ± 42.7%, range:-217 ∼ -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome

Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

Energy Technology Data Exchange (ETDEWEB)

Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae [Donga University College of Medicine, Busan (Korea, Republic of)

2005-02-15

Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 {+-} 8.5%, range:3 {approx} 35%) and mild to moderate severity (-71 {+-} 42.7%, range:-217 {approx} -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

Directory of Open Access Journals (Sweden)

Phalen David N

2010-06-01

Full Text Available Abstract Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea found in gallbladders of the invasive cane toad (Bufo marinus was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935. Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115 prior to the cane toad invasion (1879-1935. The green and golden bell frog (Litoria aurea, the Peron's tree frog (Litoria peronii, the green tree frog (Litoria caerulea and the striped marsh frog (Limnodynastes peronii were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5% at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29 of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112 frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be

Technical Note: Evaluation of a 160-mm/256-row CT scanner for whole-heart quantitative myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

So, Aaron, E-mail: aso@robarts.ca [Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2 (Canada); Imai, Yasuhiro; Nett, Brian; Jackson, John; Nett, Liz; Hsieh, Jiang [CT Engineering, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Wisenberg, Gerald; Teefy, Patrick; Yadegari, Andrew [Cardiology, University Hospital, London Health Sciences Centre, London, Ontario N6A 5A5 (Canada); Islam, Ali [Radiology, St. Joseph’s Hospital London, Ontario N6A 4V2 (Canada); Lee, Ting-Yim [Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada and Imaging Research Laboratories, Robarts Research Institute, London, Ontario N6A 5K8 (Canada)

2016-08-15

Purpose: The authors investigated the performance of a recently introduced 160-mm/256-row CT system for low dose quantitative myocardial perfusion (MP) imaging of the whole heart. This platform is equipped with a gantry capable of rotating at 280 ms per full cycle, a second generation of adaptive statistical iterative reconstruction (ASiR-V) to correct for image noise arising from low tube voltage potential/tube current dynamic scanning, and image reconstruction algorithms to tackle beam-hardening, cone-beam, and partial-scan effects. Methods: Phantom studies were performed to investigate the effectiveness of image noise and artifact reduction with a GE Healthcare Revolution CT system for three acquisition protocols used in quantitative CT MP imaging: 100, 120, and 140 kVp/25 mAs. The heart chambers of an anthropomorphic chest phantom were filled with iodinated contrast solution at different concentrations (contrast levels) to simulate the circulation of contrast through the heart in quantitative CT MP imaging. To evaluate beam-hardening correction, the phantom was scanned at each contrast level to measure the changes in CT number (in Hounsfield unit or HU) in the water-filled region surrounding the heart chambers with respect to baseline. To evaluate cone-beam artifact correction, differences in mean water HU between the central and peripheral slices were compared. Partial-scan artifact correction was evaluated from the fluctuation of mean water HU in successive partial scans. To evaluate image noise reduction, a small hollow region adjacent to the heart chambers was filled with diluted contrast, and contrast-to-noise ratio in the region before and after noise correction with ASiR-V was compared. The quality of MP maps acquired with the CT system was also evaluated in porcine CT MP studies. Myocardial infarct was induced in a farm pig from a transient occlusion of the distal left anterior descending (LAD) artery with a catheter-based interventional procedure. MP

Technical Note: Evaluation of a 160-mm/256-row CT scanner for whole-heart quantitative myocardial perfusion imaging

International Nuclear Information System (INIS)

So, Aaron; Imai, Yasuhiro; Nett, Brian; Jackson, John; Nett, Liz; Hsieh, Jiang; Wisenberg, Gerald; Teefy, Patrick; Yadegari, Andrew; Islam, Ali; Lee, Ting-Yim

2016-01-01

Purpose: The authors investigated the performance of a recently introduced 160-mm/256-row CT system for low dose quantitative myocardial perfusion (MP) imaging of the whole heart. This platform is equipped with a gantry capable of rotating at 280 ms per full cycle, a second generation of adaptive statistical iterative reconstruction (ASiR-V) to correct for image noise arising from low tube voltage potential/tube current dynamic scanning, and image reconstruction algorithms to tackle beam-hardening, cone-beam, and partial-scan effects. Methods: Phantom studies were performed to investigate the effectiveness of image noise and artifact reduction with a GE Healthcare Revolution CT system for three acquisition protocols used in quantitative CT MP imaging: 100, 120, and 140 kVp/25 mAs. The heart chambers of an anthropomorphic chest phantom were filled with iodinated contrast solution at different concentrations (contrast levels) to simulate the circulation of contrast through the heart in quantitative CT MP imaging. To evaluate beam-hardening correction, the phantom was scanned at each contrast level to measure the changes in CT number (in Hounsfield unit or HU) in the water-filled region surrounding the heart chambers with respect to baseline. To evaluate cone-beam artifact correction, differences in mean water HU between the central and peripheral slices were compared. Partial-scan artifact correction was evaluated from the fluctuation of mean water HU in successive partial scans. To evaluate image noise reduction, a small hollow region adjacent to the heart chambers was filled with diluted contrast, and contrast-to-noise ratio in the region before and after noise correction with ASiR-V was compared. The quality of MP maps acquired with the CT system was also evaluated in porcine CT MP studies. Myocardial infarct was induced in a farm pig from a transient occlusion of the distal left anterior descending (LAD) artery with a catheter-based interventional procedure. MP

Technical Note: Evaluation of a 160-mm/256-row CT scanner for whole-heart quantitative myocardial perfusion imaging.

Science.gov (United States)

So, Aaron; Imai, Yasuhiro; Nett, Brian; Jackson, John; Nett, Liz; Hsieh, Jiang; Wisenberg, Gerald; Teefy, Patrick; Yadegari, Andrew; Islam, Ali; Lee, Ting-Yim

2016-08-01

The authors investigated the performance of a recently introduced 160-mm/256-row CT system for low dose quantitative myocardial perfusion (MP) imaging of the whole heart. This platform is equipped with a gantry capable of rotating at 280 ms per full cycle, a second generation of adaptive statistical iterative reconstruction (ASiR-V) to correct for image noise arising from low tube voltage potential/tube current dynamic scanning, and image reconstruction algorithms to tackle beam-hardening, cone-beam, and partial-scan effects. Phantom studies were performed to investigate the effectiveness of image noise and artifact reduction with a GE Healthcare Revolution CT system for three acquisition protocols used in quantitative CT MP imaging: 100, 120, and 140 kVp/25 mAs. The heart chambers of an anthropomorphic chest phantom were filled with iodinated contrast solution at different concentrations (contrast levels) to simulate the circulation of contrast through the heart in quantitative CT MP imaging. To evaluate beam-hardening correction, the phantom was scanned at each contrast level to measure the changes in CT number (in Hounsfield unit or HU) in the water-filled region surrounding the heart chambers with respect to baseline. To evaluate cone-beam artifact correction, differences in mean water HU between the central and peripheral slices were compared. Partial-scan artifact correction was evaluated from the fluctuation of mean water HU in successive partial scans. To evaluate image noise reduction, a small hollow region adjacent to the heart chambers was filled with diluted contrast, and contrast-to-noise ratio in the region before and after noise correction with ASiR-V was compared. The quality of MP maps acquired with the CT system was also evaluated in porcine CT MP studies. Myocardial infarct was induced in a farm pig from a transient occlusion of the distal left anterior descending (LAD) artery with a catheter-based interventional procedure. MP maps were generated

Tl-201 myocardial perfusion scanning in patients with right bundle branch block coronary artery disease

International Nuclear Information System (INIS)

Shirani, J.; Malpani, A.R.; Blend, M.J.; Bekerman, C.

1990-01-01

This paper evaluates the specificity of stress T1-201 myocardial perfusion studies (T1-201 MPS) for coronary artery disease (CAD) in patients with right bundle branch block (RBBB). Twenty-four patients with RBBB and atypical chest pain with ECG findings limited to RBBB, adequate stress test (ie, >85% of maximal heart rate for age), and no clinical, hemodynamic, or ECG evidence of ischemia during exercise underwent T1-201 MPS. These perfusion patterns were compared with an equal number of age- and gender-matched controls with a normal ECG who met all other criteria mentioned above. Patients with RBBB showed a significantly higher frequency of reversible inferoposterior T1-201 defects (62.5% vs 20.8%)

Habitat selection, movement patterns, and hazards encountered by northern leopard frogs (Lithobates pipiens) in an agricultural landscape

Science.gov (United States)

Knutson, Melinda G.; Herner-Thogmartin, Jennifer H.; Thogmartin, Wayne E.; Kapfer, Joshua M.; Nelson, John

2018-01-01

Telemetry data for 59 Northern Leopard Frogs (Lithobates pipiens) breeding in ponds in Houston and Winona Counties, MN; 2001-2002. Agricultural intensification is causing declines in many wildlife species, including Northern Leopard Frogs (Lithobates pipiens). Specific information about frog movements, habitat selection, and sources of mortality can be used to inform conservation-focused land management and acquisition. We studied Northern Leopard Frogs in southeastern Minnesota, part of the Driftless Area ecoregion, characterized by hills and valleys and a mix of agriculture, forests, small towns and farmsteads. In this area, small farm ponds, originally built to control soil erosion are used by the species for breeding and wintering in addition to riparian wetlands. But, this agricultural landscape may be hazardous for frogs moving between breeding, feeding, and wintering habitats. We surgically implanted transmitters into the peritoneal cavity of 59 Northern Leopard Frogs and tracked them from May to October 2001-2002. The total distance traveled by radio-tagged frogs ranged from 12 to 3316 m, the 95% home range averaged 5.3 ± 1.2 (SE) ha, and the 50% core area averaged 1.05 ± 0.3 (SE) ha. As expected, Northern Leopard Frogs selected wetlands over all other land cover classes and row crops were generally avoided at all levels of selection. Only a few tracked frogs were successful at dispersing (n = 6). Most frogs attempting to disperse (n =31) ended up missing (n = 14), died due to mowing (n = 8), or were recorded as transmitter failure (n = 2) or unknown mortalities (n = 1). For the conservation of Northern Leopard Frogs in this agricultural setting, we must consider both the aquatic and the terrestrial needs of this species. Conservation agencies that restore, manage, and acquire wetlands should consider the hazards posed by land uses adjacent to frog breeding and wintering sites and plan for movement corridors between these locations. For example

A frog's-eye view of the landscape : quantifying connectivity for fragmented amphibian populations

NARCIS (Netherlands)

Vos, C.C.

1999-01-01

The spatial habitat requirements are studied for two amphibian species: the tree frog ( Hyla arborea ) and the moor frog ( Rana arvalis ). Fragmentation, the destruction of suitable habitat, results in small fragments that are separated by

Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy.

Science.gov (United States)

Eftekhari, Mohammad; Anbiaei, Robabeh; Zamani, Hanie; Fallahi, Babak; Beiki, Davood; Ameri, Ahmad; Emami-Ardekani, Alireza; Fard-Esfahani, Armaghan; Gholamrezanezhad, Ali; Seid Ratki, Kazem Razavi; Roknabadi, Alireza Momen

2015-01-01

Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right-sided cancer. To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring) were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT) to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions) over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol) was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed) and 36 patients with right-sided cancer (controls)] were enrolled. Dose-volume histogram (DVH) [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46). In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03) and anterolateral (17.1% versus 2.8%, P=0.049) walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS) of>3 was observed in twelve cases (34.3%), while in five of the controls (13.9%),(Odds ratio=1.3). There was no significant difference between the groups regarding left ventricular ejection fraction. The risk of radiation induced myocardial perfusion abnormality in patients treated with CRT on the

Pharmacological effects of Eugenia uniflora (Myrtaceae) aqueous crude extract on rat's heart.

Science.gov (United States)

Consolini, Alicia E; Sarubbio, Marisol Gracía

2002-06-01

The effect of aqueous crude extract (ACE) of Eugenia uniflora L. (Myrtaceae) was studied on rat's perfused ventricles. This plant is used in South American traditional medicine as an antihypertensive and we already demonstrated previously its hypotensive properties. In this paper, maximal left intraventriclular pressure (P) of rat's hearts beating at 0.2 Hz firstly increased to 162.1+/-11.1% of basal value during 1-3 min of perfusing ACE 0.6%. Maximum rate of contraction (+P) also increased to duplicating +P/P ratio. Both types of effect were significantly decreased by either propranolol 0.35 microM, and pre-treatment with reserpine (5 mg/kg), suggesting that they were caused by a compound that releases cathecolamines with beta-adrenergic action. Nevertheless, after 20 min of perfusing ACE, ventricles decreased P to about 50% of their basal value, suggesting a negative-inotropic compound present in the extract. The perfusion of 1.2% ACE decreased P in a pressure-[Ca](o) curve (0.5-2 mM) in a non-competitive manner, suggesting that an irreversible Ca-blocking compound is also present in the extract. In summary, E. uniflora ACE has a dual effect on the heart related to its hypotensive action and is probably responsible for the therapeutic or adverse effects in patients under cardiac risk.

Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest.

Energy Technology Data Exchange (ETDEWEB)

Horn, Scott; Hanula, James L.; Ulyshen, Michael D.; Kilgo, John C.

2005-01-01

Horn, Scott, James L. Hanula, Michael D. Ulyshen, and John C. Kilgo. 2005. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest. Am. Midl. Nat. 153:321-326. Abstract: We found more green tree frogs (Hyla cinerea) in canopy gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD

DEFF Research Database (Denmark)

Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas

2016-01-01

INTRODUCTION: Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. METHODS: 90...... perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation. TRIAL REGISTRATION NUMBER...

Reverse ventilation--perfusion mismatch

International Nuclear Information System (INIS)

Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

1984-01-01

Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve

International Nuclear Information System (INIS)

Salem, A.; Hafedh, A.; Mohsen, S.

2004-01-01

Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve. Design: The combined effect of magnetic field and cadmium (1.5mg/kg; in lymphatic sac) were studied in frog sciatic nerves (Rana Esculenta). Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma (ICP) ionic composition. Setting: Frogs (Rana Esculenta) were reared in swimming-pool (Faculte des Sciences de Bizerte, Tunisia). Frogs were cared for under the Tunisian Code of Practice for the Care and Use of Animals for Scientific purpose and the Experimental Protocols were approved by the Ethics Committee. Subjects: Treated and control groups (n=6) weighing 50-100g at the time of experiments were housed in the same condition three weeks before the beginning of the experiments. Results: Acute exposure to magnetic field increased significantly the calcium (+298%, p<0.05) and iron (+50%, p<0.05) contents of frog sciatic nerve, whereas magnesium and copper contents remained unchanged. The association between magnetic field and cadmium, induced marked increase of calcium (+360%, p<0.05), whereas magnesium content remained stable. Conclusions: Magnetic field exposure alters the ionic composition in the frog sciatic nerve, especially calcium and iron. Magnetic field magnifies the effect of cadmium on calcium homeostasis. (author)

Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

Science.gov (United States)

Swanson, Jennifer E; Bailey, Larissa L.; Muths, Erin L.; Funk, W. Chris

2013-01-01

The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer and photo identification. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphosed individuals and as a result little is known about this life-history phase for most amphibians. Our focus was to explore survival probabilities, mark retention, and mark migration in postmetamorphic Boreal Chorus Frogs (Psuedacris maculata) in a laboratory setting. One hundred forty-seven individuals were assigned randomly to two treatment groups or a control group. Frogs in the first treatment group were marked with visual implant elastomer, while frogs in the second treatment group were toe clipped. Growth and mortality were recorded for one year and resulting data were analyzed using known-fate models in Program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. We found that frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in other treatments, but individuals can be marked by clipping a single toe on two different feet without any mark loss or negative survival effects. Individuals treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6%, and also showed very little negative survival impacts relative to control individuals.

The life history of Hepatozoon leptodactyli (Lesage, 1908 Pessoa, 1970: a parasite of the common laboratory animal: the frog of the genus Leptodactylus

Directory of Open Access Journals (Sweden)

Sylvio Celso Goncalves da Costa

1973-01-01

Full Text Available The main object of the present paper is to furnish a brief account to the knowledgement of Protozoa parasitic in common Brazilian frog of the genus Leptodactylus for general students in Zoology and for investigators that use this frog as a laboratory animal. Hepatozoon leptodactyli (Haemogregarina leptodactyli was found in two species of frogs - Leptodactylus ocellatus and L. pentadactylus - in which develop schizogony whereas sporogony occurs in the leech Haementeria lutzi as was obtainded in experimental conditions. Intracellular forms have been found in peripheral circulation, chiefly in erythrocytes, but we have found them in leukocytes too. Tissue stages were found in frog, liver, lungs, spleen, gut, brain and heart. The occurence of hemogregarine in the Central Nervous System was recorded by Costa & al,(13 and Ball (2. Some cytochemical methods were employed in attempt to differentiate gametocytes from trophozoites in the peripheral blood and to characterize the cystic membrane as well. The speorogonic cycle was developed in only one specie of leech. A brief description of the parasite is given.Os autores apresentam uma revisão da hemogregarina parasita de rãs do gênero Leptodactylus. A posisção sistemática sob o ponto de vista genérico fica definida com os estudos do ciclo no vetor Haementeria lutzi, publicados em nota preliminar por um dos autores (Pessoa 24 quando utilizou rãs L. petadactylus em trabalho experimental. Este trabalho experimental continua sendo desenvolvido no Laboratório de Protozoologia do Instituto Oswaldo Cruz, utilizando a rã L. ocellatus e as sanguessugas Haementeria vizuttoi e Haementeria gracilis. Algumas técnicas citoquímicas foram empregadas para melhor caracterização dos esquizontes e das granulações do citoplasma das formas sanguíneas.

An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

Science.gov (United States)

Dreher, Corinna E; Cummings, Molly E; Pröhl, Heike

2015-01-01

Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

Comparison of parathyroid hormone and G-CSF treatment after myocardial infarction on perfusion and stem cell homing.

Science.gov (United States)

Huber, Bruno C; Fischer, Rebekka; Brunner, Stefan; Groebner, Michael; Rischpler, Christoph; Segeth, Alexander; Zaruba, Marc M; Wollenweber, Tim; Hacker, Marcus; Franz, Wolfgang-Michael

2010-05-01

Mobilization of stem cells by granulocyte colony-stimulating factor (G-CSF) was shown to have protective effects after myocardial infarction (MI); however, clinical trials failed to be effective. In search for alternative cytokines, parathyroid hormone (PTH) was recently shown to promote cardiac repair by enhanced neovascularization and cell survival. To compare the impact of the two cytokines G-CSF and PTH on myocardial perfusion, mice were noninvasively and repetitively investigated by pinhole single-photon emission computed tomography (SPECT) after MI. Mobilization and homing of bone marrow-derived stem cells (BMCs) was analyzed by fluorescence-activated cell sorter (FACS) analysis. Mice (C57BL/6J) were infarcted by left anterior descending artery ligation. PTH (80 mug/kg) and G-CSF (100 mug/kg) were injected for 5 days. Perfusion defects were determined by (99m)Tc-sestamibi SPECT at days 6 and 30 after MI. The number of BMCs characterized by Lin(-)/Sca-1(+)/c-kit(+) cells in peripheral blood and heart was analyzed by FACS. Both G-CSF and PTH treatment resulted in an augmented mobilization of BMCs in the peripheral blood. Contrary to G-CSF and controls, PTH and the combination showed significant migration of BMCs in ischemic myocardium associated with a significant reduction of perfusion defects from day 6 to day 30. A combination of both cytokines had no additional effects on migration and perfusion. In our preclinical model, SPECT analyses revealed the functional potential of PTH reducing size of infarction together with an enhanced homing of BMCs to the myocardium in contrast to G-CSF. A combination of both cytokines did not improve the functional outcome, suggesting clinical applications of PTH in ischemic heart diseases.

Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

Science.gov (United States)

Netherlands, Edward C.; Cook, Courtney A.; Kruger, Donnavan J.D.; du Preez, Louis H.; Smit, Nico J.

2015-01-01

Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity. PMID:25830113

Diversity within diversity: Parasite species richness in poison frogs assessed by transcriptomics.

Science.gov (United States)

Santos, Juan C; Tarvin, Rebecca D; O'Connell, Lauren A; Blackburn, David C; Coloma, Luis A

2018-08-01

Symbionts (e.g., endoparasites and commensals) play an integral role in their host's ecology, yet in many cases their diversity is likely underestimated. Although endoparasites are traditionally characterized using morphology, sequences of conserved genes, and shotgun metagenomics, host transcriptomes constitute an underused resource to identify these organisms' diversity. By isolating non-host transcripts from host transcriptomes, individual host tissues can now simultaneously reveal their endoparasite species richness (i.e., number of different taxa) and provide insights into parasite gene expression. These approaches can be used in host taxa whose endoparasites are mostly unknown, such as those of tropical amphibians. Here, we focus on the poison frogs (Dendrobatidae) as hosts, which are a Neotropical clade known for their bright coloration and defensive alkaloids. These toxins are an effective protection against vertebrate predators (e.g., snakes and birds), bacteria, and skin-biting ectoparasites (e.g., mosquitoes); however, little is known about their deterrence against eukaryotic endoparasites. With de novo transcriptomes of dendrobatids, we developed a bioinformatics pipeline for endoparasite identification that uses host annotated RNA-seq data and set of a priori parasite taxonomic terms, which are used to mine for specific endoparasites. We found a large community of helminths and protozoans that were mostly restricted to the digestive tract and a few systemic parasites (e.g., Trypanosoma). Contrary to our expectations, all dendrobatid frogs regardless of the presence of alkaloid defenses have endoparasites, with their highest species richness located in the frog digestive tract. Some of these organisms (e.g., roundworms) might prove to be generalists, as they were not found to be co-diversifying with their frog hosts. We propose that endoparasites may escape poison frogs' chemical defenses by colonizing tissues with fewer alkaloids than the frog's skin

Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.

Science.gov (United States)

Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

2011-06-23

Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.

Systematic review of cost-effectiveness of myocardial perfusion scintigraphy in patients with ischaemic heart disease

NARCIS (Netherlands)

Tragardh, Elin; Tan, Siok Swan; Bucerius, Jan; Gimelli, Alessia; Gaemperli, Oliver; Lindner, Oliver; Agostini, Denis; Uebleis, Christopher; Sciagra, Roberto; Slart, Riemer H.; Underwood, S. Richard; Hyafil, Fabien; Hacker, Marcus; Verberne, Hein J.

2017-01-01

Coronary artery disease (CAD) is a major cause of death and disability. Several diagnostic tests, such as myocardial perfusion scintigraphy (MPS), are accurate for the detection of CAD, as well as having prognostic value for the prediction of cardiovascular events. Nevertheless, the diagnostic and

Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

Energy Technology Data Exchange (ETDEWEB)

Horn, Scott; Hanula, James, L.; Ulyshen, Michael D.; Kilgo, John, C.

2005-04-01

ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

CTGF/CCN2 Postconditioning Increases Tolerance of Murine Hearts towards Ischemia-Reperfusion Injury.

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Ole Jørgen Kaasbøll

Full Text Available Previous studies of ischemia-reperfusion injury (IRI in hearts from mice with cardiac-restricted overexpression of CCN2 have shown that CCN2 increases tolerance towards IRI. The objectives of this study were to investigate to what extent post-ischemic administration of recombinant human CCN2 (rhCCN2 would limit infarct size and improve functional recovery and what signaling pathways are involved.Isolated mice hearts were perfused ad modum Langendorff, subjected to no-flow, global ischemia, and subsequently, exposed to mammalian cell derived, full-length (38-40kDa rhCCN2 (250 nM or vehicle during the first 15 min of a 60 min reperfusion period.Post-ischemic administration of rhCCN2 resulted in attenuation of infarct size from 58 ± 4% to 34 ± 2% (p < 0.001 which was abrogated by concomitant administration of the PI3 kinase inhibitor LY294002 (45 ± 3% vs. 50 ± 3%, ns. In congruence with reduction of infarct size rhCCN2 also improved recovery of left ventricular developed pressure (p < 0.05. Western blot analyses of extracts of ex vivo-perfused murine hearts also revealed that rhCCN2 evoked concentration-dependent increase of cardiac phospho-GSK3β (serine-9 contents.We demonstrate that post-ischemic administration of rhCCN2 increases the tolerance of ex vivo-perfused murine hearts to IRI. Mechanistically, this postconditioning effect of rhCCN2 appeared to be mediated by activation of the reperfusion injury salvage kinase pathway as demonstrated by sensitivity to PI3 kinase inhibition and increased CCN2-induced phosphorylation of GSK3β (Ser-9. Thus, the rationale for testing rhCCN2-mediated post-ischemic conditioning of the heart in more complex models is established.

Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia

Directory of Open Access Journals (Sweden)

Leandro Talione Sabagh

2012-02-01

Full Text Available We studied the feeding habits and similarities in the diet of two sympatric and syntopic Amazonian frog species, Anomaloglossus stepheni (Aromobatidae and Leptodactylus andreae (Leptodactylidae in a forested area in Central Amazonia. The breadth of the trophic niche of these species was 5.89 and 3.75, respectively, and approximately 85% of their diets were similar. Ants were main food item in the diets of both frog species. The coexistence between these frog species may be facilitated by the significant differences in the size of their mouths. This difference allows them to consume preys items of different sizes.

The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

Science.gov (United States)

Del Pino, Eugenia M

2018-01-03

The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

Value of T1-201 myocardial perfusion scan for predicting prognosis in patients with acute myocardial infarction

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Yutaka; Tomoda, Haruo [Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine; Sugihara, Masami

1983-05-01

The extent of Tl-201 perfusion defects was determined in three views by the average ratio of perfusion defects to that of the left ventricle. As the percent Tl-201 defect index increased, the peak value of creatine phosphokinase, the grade of Peel index, incidence of congestion on the initial chest X-ray, and pulmonary artery end-diastolic pressure all gradually increased. In 48 patients followed for 23 months on the average after discharge, the incidence of congestive heart failure and ventricular premature beat also increased. The prognosis was particulary poor in patients who had the percent Tl-201 defect index greater than 40%.

High-resolution MRI for the quantitative evaluation of subendocardial and subepicardial perfusion under pharmalogical stress and at rest

International Nuclear Information System (INIS)

Ritter, C.O.; Savio, K. del; Brackertz, A.; Beer, M.; Hahn, D.; Koestler, H.

2007-01-01

Purpose: MR stress perfusion imaging of the heart allows the quantification of myocardial perfusion and the evaluation of myocardial perfusion reserve (MPR) and the ratio of subendocardial to subepicardial perfusion at rest and under adenosine stress. The aim of this study was to evaluate a high-resolution GRAPPA sequence for quantitative MR first pass perfusion imaging in healthy volunteers. Materials and Methods: First pass stress and rest perfusion studies were performed on 10 healthy volunteers using a 1.5 T MR scanner with a multislice SR-TrueFISP first pass perfusion sequence with a GRAPPA algorithm (acceleration factor 3) in prebolus technique and an image resolution of 1.8 x 1.8 mm. For the comparison group, we examined 12 different healthy volunteers with a standard first pass perfusion SR-TrueFISP sequence using a resolution of 2.7 x 3.3 mm. Myocardial contours were manually delineated followed by an automatic division of the myocardium into two rings with an equal thickness for the subendo- and subepicardial layer. Eight sectors per slice were evaluated using contamination and baseline correction. Results: Using the GRAPPA sequence, the ratio of subendo- to subepimyocardial perfusion was 1.18 ± 0.32 for the examination at rest. Under pharmacologically induced stress, the ratio was 1.08 ± 0.27. For the standard sequence the ratio was 1.15 ± 0.28 at rest and 1.11 ± 0.33 under stress. For the high resolution sequence higher mean values for the subendo- to subepimyocardial ratio were obtained with comparable standard deviations. The difference between the sequences was not significant. Conclusion: The evaluation of subendomyocardial and subepimyocardial perfusion is feasible with a high-resolution first pass perfusion sequence. The use of a higher resolution to avoid systematic error leads to increased image noise. However, no relevant reduction in the quantitative perfusion values under stress and at rest was able to be depicted. (orig.)

Research on moving object detection based on frog's eyes

Science.gov (United States)

Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

2008-12-01

On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

Outcome of patients with reduced ankle brachial index undergoing open heart surgery with cardiopulmonary bypass.

Science.gov (United States)

Meyborg, Matthias; Abdi-Tabari, Zila; Hoffmeier, Andreas; Engelbertz, Christiane; Lüders, Florian; Freisinger, Eva; Malyar, Nasser M; Martens, Sven; Reinecke, Holger

2016-05-01

In open heart surgery using cardiopulmonary bypass, perfusion of the lower extremities is markedly reduced which may induce critical ischaemia in patients with pre-existing peripheral artery disease. Whether these patients have an increased risk for amputation and should better undergo peripheral revascularization prior to surgery remains unclear. From 1 January 2009 to 31 December 2010, 785 consecutive patients undergoing open heart surgery were retrospectively included. In 443 of these patients, preoperative ankle brachial index (ABI) measurements were available. The cohort was divided into four groups: (i) ABI heart surgery showed more wound-healing disturbances, and higher long-term mortality compared with those with normal ABIs. However, no perioperative ischaemia requiring amputation occurred. Thus, reduced ABIs were not associated with increased peripheral risks in open heart surgery but ABI may be helpful in selecting the site for saphenectomy to potentially avoid delayed healing of related wounds in legs with severely impaired arterial perfusion. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Of volcanoes, saints, trash, and frogs

DEFF Research Database (Denmark)

Andersen, Astrid Oberborbeck

, at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

Perfusion dyssynchrony analysis

NARCIS (Netherlands)

Chiribiri, A.; Villa, A.D.M.; Sammut, E.; Breeuwer, M.; Nagel, E.

2015-01-01

AIMS: We sought to describe perfusion dyssynchrony analysis specifically to exploit the high temporal resolution of stress perfusion CMR. This novel approach detects differences in the temporal distribution of the wash-in of contrast agent across the left ventricular wall. METHODS AND RESULTS:

Brain perfusion: computed tomography applications

International Nuclear Information System (INIS)

Miles, K.A.

2004-01-01

Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

Standardization of an isolated pig heart preparation with parabiotic circulation: methodological considerations

Directory of Open Access Journals (Sweden)

Petrucci Júnior O.

2003-01-01

Full Text Available In the present study we standardized an experimental model of parabiotic circulation of isolated pig heart. The isolated heart was perfused with arterial blood from a second animal as support and submitted to regional ischemia for 30 min, followed by total ischemia for 90 min and reperfusion for 90 min. Parameters for measurement of ventricular performance using different indices measured directly or indirectly from intraventricular pressure were defined as: maximum peak pressure, final diastolic pressure, pressure developed, first derivative of maximum pressure (dP/dt max, first derivative of minimum pressure (dP/dt min, systolic stress of the left ventricle (sigmas, and maximum elastance of the left ventricle. Isolated hearts subjected to regional and global ischemia presented significant worsening of all measured parameters. Less discriminative parameters were dP/dt max and dP/dt min. Elastance was the most sensitive parameter during the reperfusion period, demonstrating an early loss of ventricular function during reperfusion. The model proved to be stable and reproducible and permitted the study of several variables in the isolated heart, such as ischemia and reperfusion phenomena, the effects of different drugs, surgical interventions, etc. The model introduces an advantage over the classical models which use crystalloid solutions as perfusate, because parabiotic circulation mimics heart surgery with extracorporeal circulation.

Reduced ischemia-reperfusion injury with isoproterenol in non-heart-beating donor lungs.

Science.gov (United States)

Jones, D R; Hoffmann, S C; Sellars, M; Egan, T M

1997-05-01

Transplantation of lungs retrieved from non-heart-beating donors could expand the donor pool. Recent studies suggest that the ischemia-reperfusion injury (IRI) to the lung can be attenuated by increasing intracellular cAMP concentrations. The purpose of this study was to determine the effect of IRI on capillary permeability, as measured by Kfc, in lungs retrieved from non-heart-beating donors and reperfused with or without isoproterenol (iso). Using an in situ isolated perfused lung model, lungs were retrieved from non-heart-beating donor rats ventilated with O2 or not at varying intervals after death. The lungs were reperfused with or without iso (10 microM). Kfc, lung viability, and pulmonary hemodynamics were measured, and tissue levels of adenine nucleotides and cAMP were measured by HPLC. Iso-reperfusion decreased Kfc significantly (P Kfc in non-iso-reperfused (r = 0.65) and iso-perfused (r = 0.84) lungs. cAMP levels increased significantly with iso-reperfusion. cAMP levels correlated with Kfc (r = 0.87) in iso-reperfused lungs. Iso-reperfusion of lungs retrieved from non-heart-beating donor rats results in decreased capillary permeability and increased lung tissue cAMP levels. Pharmacologic augmentation of tissue TAN and cAMP levels may further ameliorate the increased capillary permeability seen in lungs retrieved from non-heart-beating donors.

An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

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Corinna E Dreher

Full Text Available Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and

Control of ribosome formation in rat heart

International Nuclear Information System (INIS)

Russo, L.A.

1987-01-01

Diabetes of 9 days duration produced a 17% diminution in the rate of total protein synthesis in rat hearts perfused as Langendorff preparations supplied with glucose, plasma levels of amino acids, and 400 μU/ml insulin. This reduction was attributable to a decrease in efficiency of protein synthesis and total RNA content. Total messenger RNA content decreased in diabetic hearts in proportion to the reduction in total RNA. Diabetes also resulted in diminished ribosome content as reflected by the induction in total RNA. Ribosome production was investigated by monitoring incorporation of [ 3 H]phenylalanine into the proteins of cytoplasmic ribosomes. Rates of ribosome formation in diabetic hearts were as fast as control rates in the presence of insulin, and were faster than control rates in the absence of the hormone. These results indicated that ribosome content fell in diabetic hearts despite unchanged or faster rates of ribosome formation

The usefulness of treatment evaluation of severe heart failure by ECG-gated myocardial SPECT

International Nuclear Information System (INIS)

Ohkoshi, Nobuyuki; Watanabe, Shingo; Matsumoto, Tooru

2011-01-01

Our purpose of study was to investigate the usefulness of treatment evaluation of severe heart failure by Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT). We evaluated the cardiac function in the case of severe heart failure by gated SPECT and compared it with the cardiac function obtained by left ventriculography (LVG), echocardiography, cardiac MRI, and B-type natriuretic peptide (BNP) values. We investigated the correlation of ejection fraction (EF), time lag of wall motion between the septal and lateral walls of the left ventricle for cardiac resynchronization therapy (CRT) and wall thickening (WT). We classified the left ventricular (LV) into basal, middle and apical areas for comparison of WT. We investigated the effect of a perfusion defect score in these comparisons. The gated SPECT results were correlated with comparative subjects in EF. The results were correlated with MRI on the middle area of the LV in the comparison of WT. We thought it was possible that there was an effect from a perfusion defect score in a time lag comparison of wall motion. Treatment evaluation of severe heart failure by gated SPECT is useful, because it is able to obtain three-dimensional cardiac function analysis, and it offers objectivity and reproducible quantitative evaluation. At the same time, perfusion SPECT is helpful for CRT and LV-plasty. (author)

Myocardial viability in cases with persistent perfusion defects on the dipyridamole thallium-201 scintigram. A comparative study with autopsy findings

International Nuclear Information System (INIS)

Nakayama, Masafumi; Mashima, Saburo; Ohkawa, Shin-ichiro; Tanno, Munehiko; Yamada, Hideo.

1996-01-01

The aim of this study was to assess the incidence of myocardial infarction among persistent perfusion defects in dipyridamole-stress thallium scintigraphy by inspecting autopsied hearts and to evaluate whether the regional thallium activity of a scintigraphic defect can predict the presence of infarction. Autopsied hearts were compared with dipyridamole myocardial scintigrams undertaken during life in 27 patients (mean age 85±8 years). The time interval from stress testing until death was 428±351 days. Regional thallium uptake of delayed perfusion defect was calculated on the short axis images. The grade of regional myocardial fibrosis in autopsy specimens was also quantified to correlate with the corresponding regional thallium uptake. In 6 of 15 (40%) regions with persistent defects on the scintigram, myocardial infarction was not found at autopsy. Regional thallium-201 uptake of delayed defects < 50% diagnosed infarction with a sensitivity of 82% and a specificity of 80%. A linear correlation (r=-0.67) was observed between percent thallium-201 uptake and the degree of myocardial fibrosis. In conclusion, perfusion defects at 4-hour imaging in dipyridamole-stress testing may overestimate the presence of myocardial infarction and regional thallium-201 activity is helpful in distinguishing between defects with and without infarction. (author)

Perfusion CT in acute stroke

International Nuclear Information System (INIS)

Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

2015-01-01

Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

GATED SPECT TO EVALUATE LEFT VENTRICULAR MYOCARDIAL PERFUSION, FUNCTION AND DYSSYNCHRONY FOR RESYNCHRONIZATION THERAPY

Directory of Open Access Journals (Sweden)

E.N. Ostroumov

2009-01-01

Full Text Available The study included 15 consecutive patients with heart failure and substantial LV dyssynchrony undergoing CRT. Clinical and phase analysis of gated myocardial perfusion SPECT assessed at baseline, after 2–3 days and after 3–4 months of CRT. The results demonstrated inversely relationship between the response to CRT and the nonviable myocardium. Evaluation of myocardial viability is necessary to considered in the selection process for CRT.

Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

Energy Technology Data Exchange (ETDEWEB)

Shi, Xuanhua; Luo, Xuan; Liang, Junling; Zhao, Peng; Di, Sheng; He, Bingsheng; Jin, Hai

2018-01-01

GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weight asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications and

Roselle Polyphenols Exert Potent Negative Inotropic Effects via Modulation of Intracellular Calcium Regulatory Channels in Isolated Rat Heart.

Science.gov (United States)

Lim, Yi-Cheng; Budin, Siti Balkis; Othman, Faizah; Latip, Jalifah; Zainalabidin, Satirah

2017-07-01

Roselle (Hibiscus sabdariffa Linn.) calyces have demonstrated propitious cardioprotective effects in animal and clinical studies; however, little is known about its action on cardiac mechanical function. This study was undertaken to investigate direct action of roselle polyphenols (RP) on cardiac function in Langendorff-perfused rat hearts. We utilized RP extract which consists of 12 flavonoids and seven phenolic acids (as shown by HPLC profiling) and has a safe concentration range between 125 and 500 μg/ml in this study. Direct perfusion of RP in concentration-dependent manner lowered systolic function of the heart as shown by lowered LVDP and dP/dt max , suggesting a negative inotropic effect. RP also reduced heart rate (negative chronotropic action) while simultaneously increasing maximal velocity of relaxation (positive lusitropic action). Conversely, RP perfusion increased coronary pressure, an indicator for improvement in coronary blood flow. Inotropic responses elicited by pharmacological agonists for L-type Ca 2+ channel [(±)-Bay K 8644], ryanodine receptor (4-chloro-m-cresol), β-adrenergic receptor (isoproterenol) and SERCA blocker (thapsigargin) were all abolished by RP. In conclusion, RP elicits negative inotropic, negative chronotropic and positive lusitropic responses by possibly modulating calcium entry, release and reuptake in the heart. Our findings have shown the potential use of RP as a therapeutic agent to treat conditions like arrhythmia.

Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

Energy Technology Data Exchange (ETDEWEB)

Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

2016-08-15

In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

Water Frogs, Aquariums, and Salmonella -- Oh My!

Centers for Disease Control (CDC) Podcasts

2009-12-09

This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs.

Science.gov (United States)

Knutie, Sarah A; Shea, Lauren A; Kupselaitis, Marinna; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

2017-10-01

Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against

Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous–Paleogene boundary

Science.gov (United States)

Feng, Yan-Jie; Liang, Dan; Hillis, David M.; Cannatella, David C.; Zhang, Peng

2017-01-01

Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous–Paleogene (K–Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K–Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation. PMID:28673970

Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary.

Science.gov (United States)

Feng, Yan-Jie; Blackburn, David C; Liang, Dan; Hillis, David M; Wake, David B; Cannatella, David C; Zhang, Peng

2017-07-18

Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous-Paleogene (K-Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K-Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation.

The effect of methyl-lidocaine on the biosynthesis of phospholipids de novo in the isolated hamster heart.

OpenAIRE

Tardi, P G; Man, R Y; Choy, P C

1992-01-01

Methyl-lidocaine is an amphiphilic agent which has been used as an experimental anti-arrhythmic drug. When hamster hearts were perfused with labelled glycerol, the presence of methyl-lidocaine in the perfusate was found to enhance the labelling in phosphatidylserine, phosphatidylinositol, diacylglycerol and triacylglycerol. However, the labelling of phosphatidylcholine and phosphatidylethanolamine was not significantly changed by methyl-lidocaine treatment. Assays in vitro for the enzymes inv...

A success model and implementation on examining teacher’s attitude in using frog virtual learning environment

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Wan Rozaini Sheik Osman

2017-12-01

Full Text Available The Frog Virtual Learning Environment (Frog VLE together with school administrators, teachers, students and parents has formed the concept of a virtual community within the school environment. The research uses a qualitative approach that involves interviewing four selected teachers in a primary school located in the district of Baling/ Sik, Kedah. The study employs a structured questionnaire as an interview protocol instrument. The questionnaires were also distributed to sixteen other teachers to compare the responses. The findings showed that teachers were using Frog VLE application and it helps in teaching and learning. Frog VLE also motivates teachers to teach better. However, not all teachers are comfortable using it because there are many obstacles and constraints that teachers face when applying them. The analysis of result from the teacher’s attitude indicated that there was an important relationship between the teacher’s basic knowledge of ICT and the skills in accessing the Frog VLE.

COMPARATIVE ACTIVITY OF CECROPIN A AND POLYMYXIN B AGAINST FROG BACTERIAL PATHOGENS

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Ermin Schadich

2013-03-01

Full Text Available The antimicrobial activity of two antimicrobial peptides, cecropin A and polymyxin B against different bacterial pathogens associated with bacterial dermatosepticemia, a fatal bacterial infectious disease of frogs was investigated. The peptides were tested in serial of concentrations (100-0.19 µg/ml for growth inhibition of seven pathogens: Aeromonas hydrophila, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Serratia liquefaciens. Their antimicrobial activity was compared with that of two antimicrobial peptides from frog skin, magainin 2 and aurein 2.1. Both cecropin A and polymyxin B, completely inhibited the growth of three pathogens: C. freundii, K. pneumoniae and P. aeruginosa at a concentration some sixteen times less than two skin peptides. Furthermore, cecropin A inhibited the growth of three pathogens resistant to the two skin peptides, A. hydrophila, C. meningosepticum and P. mirabilis. Polymyxin B also inhibited the growth of three pathogens resistant to the skin peptides, A. hydrophila, C. meningosepticum and S. liquefaciens. Cecropin A and polymyxin B have marked antibacterial activity against different frog bacterial pathogens indicating potential for therapeutic measures.Keywords: frogs, antimicrobial, bacteria, cecropin, polymyxin, resistance

Biodistribution of radioactive organocations and cationic technetium complexes - implications to the uptake mechanism of potential heart-affine radiopharmaceuticals

International Nuclear Information System (INIS)

Muenze, R.; Shyre, R.; Seifert, S.; Guethert, I.; Kretschmar, M.; Kampf, G.; Knop, G.; Mohnike, W.; Schmidt, J.

1986-01-01

The biodistribution of various 14 C labeled organocations (ammonium, phosphonium) and cationic technetium complexes (TcCl 2 DMPE 2 ,TcDMPE 3 + ) was studied in rats to find potential relations between the chemical composition, structure, molecular size, lipophilicity and heart uptake. All of the radioactive cations were distributed in a similar manner, but with different biokinetics. Molecules containing several electronegative atoms in their ligand structure, e.g. nitrogen or oxygen which enhance polarity, were rapidly accumulated, but washed out again with resultant transient and diminished heart uptake. More highly lipophilic materials, by contrast, showed more extensive accumulation and persistent retention in the heart. The effect of human serum albumin on heart uptake was studied in a perfused heart model. Strong albumin binding prevented extensive heart uptake. This undesirable effect was neutralized by adding detergents to the perfusion bath. Evidence from these animal experiments was considered in the development of a new heart-seeking technetium compound (Tc-DPO), which is characterized by rapid accumulation in the human heart and substantially delayed washout. Heart images with minimal overlap of the inferoposterior wall and the right liver lobe were available in no more than 10 minutes p.i. in both planar and SPECT modes. A deficit in the inferior region was much more clearly defined than on the corresponding Thallium image. (Author)

Diagnostic value of perfusion 201Tl scintigraphy of the myocardium in assessing right ventricular hypertrophy

International Nuclear Information System (INIS)

Jandova, R.; Bakos, K.; Fridl, P.

1986-01-01

Perfusion scintigraphy of the heart muscle with Tl 201 was tested in the diagnosis of overloading of the right ventricle in a group of 24 patients with chronic pulmonary disease and in a group of 26 patients with mitral stenosis only. The results of scintigraphy of the heart muscle and ECG examination were compared with results of the examination of haemodynamics of the lesser circulation, blood gases and spirometric examination. The study shows that thallium scintigraphy is a fairly sensitive method for noninvasive diagnosis of pulmonary arterial hypertension. It is an auxiliary method and its validity increases when combined with other noninvasive methods. (author)

Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

Science.gov (United States)

Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

2008-09-01

Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

The potential effects of climate change on the status of Seychelles frogs (Anura: Sooglossidae

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J. Gerlach

2011-11-01

Full Text Available The status of the Seychelles frogs of the family Sooglossidae was investigated, using monitoring data from 1993-2010, climate data from 1998-2010 and studies of populations and local climate effects. Climate monitoring at each plot covered rainfall and temperature, with leaf wetness and soil moisture being monitored additionally at one site. Analysis of the data and ecological modelling of the distribution identify geographical patterns in climate which explain the present distribution of the different sooglossid species. In addition it identifies a drying trend in the first quarter of the year which corresponds to frog population declines in mid-altitude forests. This is interpreted as evidence of an ongoing deterioration in the suitability of habitats for the frogs, with declines recorded in areas of marginal suitability. By extension it is assumed that currently optimal frog habitat is also undergoing a decline in suitability, due to early year decreases in moisture. Projected changes in climate were used to predict changes in ranges of the sooglossids over the next 90 years. This predicts significant declines, with the possible extinction of the palm frog Sooglossus pipilodryas by 2100. Accordingly all four sooglossid species should be categorised as Endangered, rather than their current status of Vulnerable. Captive assurance colonies have not been successfully established to date. Captive groups have been maintained with a high degree of success but breeding has not been recorded so far. Further work needed for the conservation of the frogs is outlined: development of a reliable method of monitoring the cryptic S. thomasseti and development of captive breeding techniques.

Standardized perfusion value of the esophageal carcinoma and its correlation with quantitative CT perfusion parameter values

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Djuric-Stefanovic, A., E-mail: avstefan@eunet.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Saranovic, Dj., E-mail: crvzve4@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Sobic-Saranovic, D., E-mail: dsobic2@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia); Masulovic, D., E-mail: draganmasulovic@yahoo.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Artiko, V., E-mail: veraart@beotel.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia)

2015-03-15

Purpose: Standardized perfusion value (SPV) is a universal indicator of tissue perfusion, normalized to the whole-body perfusion, which was proposed to simplify, unify and allow the interchangeability among the perfusion measurements and comparison between the tumor perfusion and metabolism. The aims of our study were to assess the standardized perfusion value (SPV) of the esophageal carcinoma, and its correlation with quantitative CT perfusion measurements: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) of the same tumor volume samples, which were obtained by deconvolution-based CT perfusion analysis. Methods: Forty CT perfusion studies of the esophageal cancer were analyzed, using the commercial deconvolution-based CT perfusion software (Perfusion 3.0, GE Healthcare). The SPV of the esophageal tumor and neighboring skeletal muscle were correlated with the corresponding mean tumor and muscle quantitative CT perfusion parameter values, using Spearman's rank correlation coefficient (r{sub S}). Results: Median SPV of the esophageal carcinoma (7.1; range: 2.8–13.4) significantly differed from the SPV of the skeletal muscle (median: 1.0; range: 0.4–2.4), (Z = −5.511, p < 0.001). The cut-off value of the SPV of 2.5 enabled discrimination of esophageal cancer from the skeletal muscle with sensitivity and specificity of 100%. SPV of the esophageal carcinoma significantly correlated with corresponding tumor BF (r{sub S} = 0.484, p = 0.002), BV (r{sub S} = 0.637, p < 0.001) and PS (r{sub S} = 0.432, p = 0.005), and SPV of the skeletal muscle significantly correlated with corresponding muscle BF (r{sub S} = 0.573, p < 0.001), BV (r{sub S} = 0.849, p < 0.001) and PS (r{sub S} = 0.761, p < 0.001). Conclusions: We presented a database of the SPV for the esophageal cancer and proved that SPV of the esophageal neoplasm significantly differs from the SPV of the skeletal muscle, which represented a sample of healthy

Normal myocardial perfusion imaging in the presence of significant coronary artery stenosis

International Nuclear Information System (INIS)

Tian Yueqin; He Zuoxiang; Fang Wei; Yang Minfu; Shen Rui

2007-01-01

Objective: The aim of this study was to investigate the factors which might result in normal myocardial perfusion imaging in the presence of significant coronary artery stenosis. Methods: One hundred and thirty-three patients [mean age of (59±10) years, 98 men, 35 women] who underwent coronary angiography and myocardial perfusion SPECT were retrospectively analyzed. Results: Forty-six (35%) patients performed adequate bicycle exercise testing and achieved more than 85% of their predicted maximal heart rates; while 87 (65%) patients did not. Eighty-four (63%) patients had single coronary stenosis, 31(23%) two-vessel and 17(13%) three-vessel diseases. The difference in stenosis severity among the vessels in 13 (76%) cases with three-vessel diseases was not more than 20%. There were totally 202 coronary artery stenosis: 93 (46%) in left anterior descending coronary artery (LAD), 52 (26%) left circumflex coronary artery (LCX), 52(26% ) right coronary artery (RCA) and 5 (2%) left main coronary artery (LM) disease. Eighty-six(43%) vessels had 50%-70% stenosis, 100 (49%) >70%-90% and 16(8% )more than 90%. Conclusion: Normal myocardial perfusion imaging with significant coronary artery stenosis can probably due to inadequate exercise, single vessel disease and mild to moderate stenotic lesion. (authors)

Vasoactive mediators and splanchnic perfusion.

Science.gov (United States)

Reilly, P M; Bulkley, G B

1993-02-01

To provide an overview of the splanchnic hemodynamic response to circulatory shock. Previous studies performed in our own laboratory, as well as a computer-assisted search of the English language literature (MEDLINE, 1966 to 1991), followed by a selective review of pertinent articles. Studies were selected that demonstrated relevance to the splanchnic hemodynamic response to circulatory shock, either by investigating the pathophysiology or documenting the sequelae. Article selection included clinical studies as well as studies in appropriate animal models. Pertinent data were abstracted from the cited articles. The splanchnic hemodynamic response to circulatory shock is characterized by a selective vasoconstriction of the mesenteric vasculature mediated largely by the renin-angiotensin axis. This vasospasm, while providing a natural selective advantage to the organism in mild-to-moderate shock (preserving relative perfusion of the heart, kidneys, and brain), may, in more severe shock, cause consequent loss of the gut epithelial barrier, or even hemorrhagic gastritis, ischemic colitis, or ischemic hepatitis. From a physiologic standpoint, nonpulsatile cardiopulmonary bypass, a controlled form of circulatory shock, has been found experimentally to significantly increase circulating levels of angiotensin II, the hormone responsible for this selective splanchnic vasoconstriction. While angiotensin II has been viewed primarily as the mediator responsible for the increased total vascular resistance seen during (and after) cardiopulmonary bypass, it may also cause the disproportionate decrease in mesenteric perfusion, as measured in human subjects by intraluminal gastric tonometry and galactose clearance by the liver, as well as the consequent development of the multiple organ failure syndrome seen in 1% to 5% of patients after cardiac surgery.

Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

DEFF Research Database (Denmark)

Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

2007-01-01

arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...

Protection of Ischemic and Reperfused Rat Heart by Aqueous Extract of Urtica Dioica

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D Shackebaei

2010-09-01

Full Text Available Background: Urtica dioica (U.D has widely been used in traditional medicine for its hypotensive and vasodilatory effects. The objective of this study was to clarify the effects of aqueous extract of Urtica dioica on isolated ischemia- reperfused heart.Methods: The heart of male wistar rats were isolated and perfused according to langendorff method. In the control group (n = 13 the hearts were subjected to three steps of stabilization (30 min, normothermic global ischemia (40 min and reperfusion (45 min. In addition, before and after ischemia, the aqueous extract of U.D (200 mg/ml was added to perfusion solution in the test group (n=14. Different cardiac variables including left ventricular pressure, heart rate and coronary flow were measured and rate pressure product was calculated.Results: Results showed that left ventricular pressure (59.11±4.7 and rate pressure product (13680±1136 in 45th minute of reperfusion in the test group were significantly (P=0.0187 and 0.0321 respectively greater than the control group (39.1±6.0, 9480±1480 respectively. These findings indicated decreased cardiac damage following ischemia in the test group, compared with that of control group.Conclusion: Results of the present study showed that the aqueous extract of U.D, increased the tolerance of isolated rat hearts against ischemic damage. This effect can be explained by potent antioxidant activity of the U.D extract, suggesting its clinical use in ischemic heart disease.

Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture

Science.gov (United States)

Smalling, Kelly L.; Reeves, Rebecca; Muths, Erin L.; Vandever, Mark W.; Battaglin, William A.; Hladik, Michelle; Pierce, Clay L.

2015-01-01

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and

Nuclear magnetic resonance of perfused tissue

International Nuclear Information System (INIS)

Harpen, M.D.; Allison, R.C.

1986-01-01

The effect of perfusion on the NMR signal observed in NMR imaging is studied in a phantom and in two isolated perfused canine lungs. It is observed that perfusion in tissue has little effect on longitudinal relaxation times. Transverse relaxation rates are observed to correlate linearly with rates of perfusion, in accordance with a model presented. (author)

Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

NARCIS (Netherlands)

Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

2016-01-01

Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

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Brett R. Scheffers

2014-12-01

Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats. Keywords: Climate change, Functionality, Microhabitat, Refuge, Ectotherm, Precipitation

Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy

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Mohammad Eftekhari

2015-01-01

Full Text Available Objective(s: Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right–sided cancer. Methods: To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. Results: A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed and 36 patients with right-sided cancer (controls] were enrolled. Dose-volume histogram (DVH [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46. In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03 and anterolateral (17.1% versus 2.8%, P=0.049 walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS of>3 was observed in twelve cases (34.3%, while in five of the controls (13.9%,(Odds ratio=1.3. There was no significant difference between the groups regarding left ventricular ejection fraction. Conclusion: The risk of radiation induced myocardial

Methodology for ventilation/perfusion SPECT

DEFF Research Database (Denmark)

Bajc, Marika; Neilly, Brian; Miniati, Massimo

2010-01-01

radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

Use of corrosion casting techniques to evaluate coronary collateral vessels and anastomoses in hearts of canine cadavers.

Science.gov (United States)

Noestelthaller, Arne; Probst, Alexander; Koenig, Horst E

2005-10-01

To study and investigate branching patterns of the canine coronary arteries and collateral circulation by use of corrosion casting techniques. 31 hearts obtained from cadavers of clinically normal dogs of various ages and breeds and of either sex. 3-dimensional reproduction of coronary arteries was achieved by postmortem injection and perfusion with casting materials into the aortic sinus via the ascending aorta. Perfused hearts were macerated and carefully irrigated; the air-dried specimens were examined macroscopically and with a magnifying headset. Collateral arteries and inter- and intra-arterial anastomoses were successfully detected in 8 corrosion cast specimens. In total, 9 coronary collateral arteries and 3 interarterial anastomoses were found. Our finding of coronary collateral arteries in canine hearts is in agreement with recent findings in coronary flow study. On the basis of our results, vasodilation treatment to improve collateral vessel remodeling in dogs with myocardial dysfunction may be warranted.

ICE on the road to auditory sensitivity reduction and sound localization in the frog.

Science.gov (United States)

Narins, Peter M

2016-10-01

Frogs and toads are capable of producing calls at potentially damaging levels that exceed 110 dB SPL at 50 cm. Most frog species have internally coupled ears (ICE) in which the tympanic membranes (TyMs) communicate directly via the large, permanently open Eustachian tubes, resulting in an inherently directional asymmetrical pressure-difference receiver. One active mechanism for auditory sensitivity reduction involves the pressure increase during vocalization that distends the TyM, reducing its low-frequency airborne sound sensitivity. Moreover, if sounds generated by the vocal folds arrive at both surfaces of the TyM with nearly equal amplitudes and phases, the net motion of the eardrum would be greatly attenuated. Both of these processes appear to reduce the motion of the frog's TyM during vocalizations. The implications of ICE in amphibians with respect to sound localizations are discussed, and the particularly interesting case of frogs that use ultrasound for communication yet exhibit exquisitely small localization jump errors is brought to light.

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

Science.gov (United States)

Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

2016-04-01

Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Direct comparison of cardioprotective effects of necroptosis inhibitors against global ischemia-reperfusion in the isolated rat heart

Directory of Open Access Journals (Sweden)

Yu. V. Dmitriev

2017-01-01

Full Text Available The study was aimed at comparative assessment of cardioprotective properties of various necroptosis inhibitors in the isolated perfused rat heart subjected to global ischemia-reperfusion.Materials and Methods. The study was performed on 38 male Wistar rats weighting 250–300 g. The following necroptosis inhibitors were tested: necrostatin-1 (Nec-1, necrostatin-5 (Nec-5, necrostatin-1s (Nec1s, and necrosulfonamide (NSA. All tested substances were administered intraperitoneally (i.p. 1 hour prior to heart perfusion. Control animals were treated either with the vehicle (dimethyl sulfoxide, DMSO or with 0,9% sodium chloride solution (Controls. The dose of necroptosis inhibitors was calculated on the basis of effective concentration (EC50 data. One hour after i.p. injection, the animals were anesthetized, the hearts were rapidly excised, the aorta was cannulated and retrogradely perfused according to Langendorff. After stabilization, the perfusion was stopped for 35 minutes, which was followed by 2 hours of reperfusion. Prior to stabilization, fluid-filled polyethylene balloon was placed into the left ventricle for left ventricular pressure registration. Coronary flow was measured at baseline and during reperfusion by means of perfusate collection. The volume of necrotic myocardium was expressed as a percentage of triphenyltetrazolium chloride-negative tissue relative to the entire heart volume.Results. The volume of myocardial necrosis and functional heart parameters were not different between Controls and DMSO group. All tested necroptosis inhibitors demonstrated infarct-limiting effect. However, there were no differences between the groups. The volume of necrotic myocardium was (50,5 ± 7,82%, (29,9 ± 3,42%, (27,7 ± 3,42%, (30,6 ± 3,82%, and (34,7 ± 5,82% in DMSO, Nec-1, Nec-5, Nec-1s, and NSA groups, respectively (p < 0,01 vs. DMSO group.Nec-1s and NSA were shown to improve functional recovery of the heart after ischemia. In particular, left

Hydrostatic determinants of cerebral perfusion

International Nuclear Information System (INIS)

Wagner, E.M.; Traystman, R.J.

1986-01-01

We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure

FROG ASSEMBLAGE ASSOCIATED WITH BROMELIADS IN A SANDY COASTAL PLAIN IN THE STATE OF ESPÍRITO SANTO, SOUTHEASTERN BRAZIL

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MARCIO MARQUES MAGESKI

Full Text Available ABSTRACT Amphibians may use bromeliads for reproduction (i.e., bromeligenous species or only for refuge and foraging (i.e., bromelicolous species. The partition of bromeliad resources is essential to maintain the coexistence of the associated assemblages. We sampled 913 bromeliads in a sandy coastal plain (i.e., restinga habitat in southeastern Brazil and found 234 frogs belonging to seven species. One of the frog species was bromeligenous and the other six were facultative bromelicolous. The bromeliads of the genus Aechmea were the most frequently used by frogs. The low degree of frog occupancy of bromeliads (26% suggests habitat segregation. Our study highlights the importance of maintenance of bromeliad species for conservation of the associated frog assemblages.

Transplantation of Hearts Donated after Circulatory Death

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Christopher W. White

2018-02-01

Full Text Available Cardiac transplantation has become limited by a critical shortage of suitable organs from brain-dead donors. Reports describing the successful clinical transplantation of hearts donated after circulatory death (DCD have recently emerged. Hearts from DCD donors suffer significant ischemic injury prior to organ procurement; therefore, the traditional approach to the transplantation of hearts from brain-dead donors is not applicable to the DCD context. Advances in our understanding of ischemic post-conditioning have facilitated the development of DCD heart resuscitation strategies that can be used to minimize ischemia-reperfusion injury at the time of organ procurement. The availability of a clinically approved ex situ heart perfusion device now allows DCD heart preservation in a normothermic beating state and minimizes exposure to incremental cold ischemia. This technology also facilitates assessments of organ viability to be undertaken prior to transplantation, thereby minimizing the risk of primary graft dysfunction. The application of a tailored approach to DCD heart transplantation that focuses on organ resuscitation at the time of procurement, ex situ preservation, and pre-transplant assessments of organ viability has facilitated the successful clinical application of DCD heart transplantation. The transplantation of hearts from DCD donors is now a clinical reality. Investigating ways to optimize the resuscitation, preservation, evaluation, and long-term outcomes is vital to ensure a broader application of DCD heart transplantation in the future.

Normothermic versus hypothermic cardiopulmonary bypass in children undergoing open heart surgery (thermic-2): study protocol for a randomized controlled trial.

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Baos, Sarah; Sheehan, Karen; Culliford, Lucy; Pike, Katie; Ellis, Lucy; Parry, Andrew J; Stoica, Serban; Ghorbel, Mohamed T; Caputo, Massimo; Rogers, Chris A

2015-05-25

During open heart surgery, patients are connected to a heart-lung bypass machine that pumps blood around the body ("perfusion") while the heart is stopped. Typically the blood is cooled during this procedure ("hypothermia") and warmed to normal body temperature once the operation has been completed. The main rationale for "whole body cooling" is to protect organs such as the brain, kidneys, lungs, and heart from injury during bypass by reducing the body's metabolic rate and decreasing oxygen consumption. However, hypothermic perfusion also has disadvantages that can contribute toward an extended postoperative hospital stay. Research in adults and small randomized controlled trials in children suggest some benefits to keeping the blood at normal body temperature throughout surgery ("normothermia"). However, the two techniques have not been extensively compared in children. The Thermic-2 study will test the hypothesis that the whole body inflammatory response to the nonphysiological bypass and its detrimental effects on different organ functions may be attenuated by maintaining the body at 35°C-37°C (normothermic) rather than 28°C (hypothermic) during pediatric complex open heart surgery. This is a single-center, randomized controlled trial comparing the effectiveness and acceptability of normothermic versus hypothermic bypass in 141 children with congenital heart disease undergoing open heart surgery. Children having scheduled surgery to repair a heart defect not requiring deep hypothermic circulatory arrest represent the target study population. The co-primary clinical outcomes are duration of inotropic support, intubation time, and postoperative hospital stay. Secondary outcomes are in-hospital mortality and morbidity, blood loss and transfusion requirements, pre- and post-operative echocardiographic findings, routine blood gas and blood test results, renal function, cerebral function, regional oxygen saturation of blood in the cerebral cortex, assessment of

Rest thallium-201 myocardial perfusion imaging in a patient with leukaemic infiltration of the heart

International Nuclear Information System (INIS)

Civelek, A.C.; Camargo, E.E.; Links, J.M.; Brinker, J.A.; Wagner, H.N. Jr.

1992-01-01

Despite the high incidence of leukaemic infiltration of the heart, only 8 cases of atrioventricular block due to leukemia have been reported in the literature. Improvement in the heart block associated with disappearance of the leukaemic infiltrate has not been reported. A rest thallium-201 study was used in a 65-year-old man to demonstrate leukaemic infiltration of the heart which was associated with complete heart block. After chemotherapy, when the tumour burden was reduced and the leukaemia in remission, his heart block resolved, and a follow-up thallium scan was normal. (orig.)

Utility of Deep Inspiration Breath Hold for Left-Sided Breast Radiation Therapy in Preventing Early Cardiac Perfusion Defects: A Prospective Study

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Zagar, Timothy M., E-mail: zagar@med.unc.edu [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Kaidar-Person, Orit [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Tang, Xiaoli [Memorial Sloan Kettering Cancer Center, West Harrison, New York (United States); Jones, Ellen E.; Matney, Jason; Das, Shiva K.; Green, Rebecca L. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Sheikh, Arif [Department of Radiology, Columbia University, New York, New York (United States); Khandani, Amir H.; McCartney, William H.; Oldan, Jorge Daniel; Wong, Terence Z. [Department of Radiology, University of North Carolina, Chapel Hill, North Carolina (United States); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States)

2017-04-01

Purpose: To evaluate early cardiac single photon computed tomography (SPECT) findings after left breast/chest wall postoperative radiation therapy (RT) in the setting of deep inspiration breath hold (DIBH). Methods and Materials: We performed a prospective single-institution single-arm study of patients who were planned for tangential RT with DIBH to the left breast/chest wall (± internal mammary nodes). The DIBH was done by use of a controlled surface monitoring technique (AlignRT, Vision RT Ltd, London, UK). The RT was given with tangential fields and a heart block. Radiation-induced cardiac perfusion and wall motion changes were assessed by pre-RT and 6-month post-RT SPECT scans. A cumulative SPECT summed-rest score was used to quantify perfusion in predefined left ventricle segments. The incidence of wall motion abnormalities was assessed in each of these same segments. Results: A total of 20 patients with normal pre-RT scans were studied; their median age was 56 years (range, 39-72 years). Seven (35%) patients also received irradiation to the left internal mammary chain, and 5 (25%) received an additional RT field to supraclavicular nodes. The median heart dose was 94 cGy (range, 56-200 cGy), and the median V25{sub Gy} was zero (range, 0-0.1). None of the patients had post-RT perfusion or wall motion abnormalities. Conclusions: Our results suggest that DIBH and conformal cardiac blocking for patients receiving tangential RT for left-sided breast cancer is an effective means to avoid early RT-associated cardiac perfusion defects.

Cerebral Perfusion and the Risk of Dementia: A Population-Based Study.

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Wolters, Frank J; Zonneveld, Hazel I; Hofman, Albert; van der Lugt, Aad; Koudstaal, Peter J; Vernooij, Meike W; Ikram, M Arfan

2017-08-22

Cerebral hypoperfusion has previously been associated with mild cognitive impairment and dementia in various cross-sectional studies, but whether hypoperfusion precedes neurodegeneration is unknown. We prospectively determined the association of cerebral perfusion with subsequent cognitive decline and development of dementia. Between 2005 and 2012, we measured cerebral blood flow by 2-dimensional phase-contrast magnetic resonance imaging in participants of the population-based Rotterdam Study without dementia. We determined the association of cerebral perfusion (mL/100mL/min) with risk of dementia (until 2015) using a Cox model, adjusting for age, sex, demographics, cardiovascular risk factors, and apolipoprotein E genotype. We repeated analyses for Alzheimer disease and accounting for stroke. We used linear regression to determine change in cognitive performance during 2 consecutive examination rounds in relation to perfusion. Finally, we investigated whether associations were modified by baseline severity of white matter hyperintensities. Of 4759 participants (median age 61.3 years, 55.2% women) with a median follow-up of 6.9 years, 123 participants developed dementia (97 Alzheimer disease). Lower cerebral perfusion was associated with higher risk of dementia (adjusted hazard ratio, 1.31; 95% confidence interval per standard deviation decrease, 1.07-1.61), similar for Alzheimer disease only, and unaltered by accounting for stroke. Risk of dementia with hypoperfusion was higher with increasing severity of white matter hyperintensities (with severe white matter hyperintensities; hazard ratio, 1.54; 95% confidence interval, 1.11-2.14). At cognitive reexamination after on average 5.7 years, lower baseline perfusion was associated with accelerated decline in cognition (global cognition: β=-0.029, P =0.003), which was similar after excluding those with incident dementia, and again most profound in individuals with higher volume of white matter hyperintensities ( P

Effect of nicorandil on the myocardial tissue perfusion and myocardial cell injury in patients with diabetes after PCI

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Xue-Li Ren1

2017-04-01

Full Text Available Objective: To study the effect of nicorandil on the myocardial tissue perfusion and myocardial cell damage in patients with diabetes after percutaneous coronary intervention (PCI. Methods: 68 patients with coronary heart disease and type 2 diabetes mellitus who received PCI in our hospital between May 2011 and September 2015 were collected and then divided into observation group and control group (n=34 according to the single-blind randomized control method. Control group of patients received PCI alone, and the observation group of patients received nicorandil therapy after PCI. After treatment, real-time myocardial ultrasound contrast was used to evaluate the myocardial perfusion of two groups of patients; blood biochemical analyzer was used to detect the contents of peripheral blood myocardial enzyme spectrum indexes; the ELISA method was used to detect the contents of serum oxidative stress indicators; RIA method was used to detect the contents of serum apoptosis molecules. Results: After treatment, the myocardial tissue perfusion parameters plateau peak intensity (A, slope rate of curve (β and myocardial blood flow (A×β levels of observation group were significantly higher than those of control group (P<0.05; peripheral blood myocardial enzyme spectrum indexes creatine kinase (CK, lactate dehydrogenase (LDH, troponin I (cTnI and glutamic oxalacetic transaminase (GOT contents of observation group were significantly lower than those of control group (P<0.05; serum vitamin E (VitE and vitamin C (VitC contents of observation group were significantly higher than those of control group while malondialdehyde (MDA, advanced oxidation protein products (AOPPs, soluble apoptosis-associated factor (sFas and soluble apoptosis-associated factor ligand (sFasL contents were lower than those of control group (P<0.05. Conclusion: Adjuvant nicorandil therapy can improve the myocardial perfusion and reduce the myocardial cell injury in patients with coronary

Acute Toxicity of a Heavy Metal Cadmium to an Anuran, the Indian Skipper Frog Rana cyanophlyctis

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Ajai Kumar Srivastav

2016-08-01

Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis. Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of cadmium chloride (15, 20, 25, 30, 35, 40, 45 and 50 mg/L. At different exposure periods (24, 48, 72 and 96 h, the mortality of the frog was subjected to Probit analysis with the POLO-PC software (LeOra Software to calculate the LC50 and 95% confidence level. Results: The LC50 values of cadmium chloride for the frog R. cyanophlyctis at 24, 48, 72, and 96 h are 32.586, 29.994, 27.219 and 23.048 mg/L, respectively. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish. Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals.

Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

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Mark A Lum

Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA and intravenous (IV T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA dural, internal carotid artery (ICA dural, or pial. MR perfusion data regions of interest (ROIs were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM, relative cerebral blood flow (rCBF, relative cerebral blood volume (rCBV, and mean transit time (MTT. Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling.18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11, ICA dural (n = 4, or pial (n = 3. FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs

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Todd G. Smith

2012-04-01

Full Text Available The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.

Discovery of alien water frogs (gen. Pelophylax in Umbria, with first report of P. shqipericus for Italy

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Dario Domeneghetti

2013-12-01

Full Text Available Allochthonous water frogs (gen. Pelophylax have been repeatedly introduced in several European countries, causing dramatic consequences for the conservation of indigenous taxa. In Italy, invasive populations are known for northern regions, where they were introduced mainly for edible and scientific purposes. Here, we report the first detection of an alien population of water frogs in Central Italy, along the Resina valley (Umbria. Genetic analysis of the mitochondrial ND3 gene polymorphism assigned some specimens to two different Pelophylax ridibundus clades widespread in Central and Eastern Europe. By contrast, two samples matched the mitochondrial DNA (mtDNA sequence of Pelophylax lessonae bergeri, an autochthonous taxon widespread in Central Italy, suggesting possible hybridization between alien and indigenous frogs. Finally, the specific haplotype of Pelophylax shqipericus, the Albanian Pool Frog, was also identified according to mtDNA polymorphism. This record, firstly reported for Italy, poses concerns for the conservation of this cryptic taxon, suggesting that international water frog trade may involve also particularly endangered species.

Pulmonary perfusion ''without ventilation''

International Nuclear Information System (INIS)

Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

1983-01-01

An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

Effects Of The Direct Renin Inhibitor Aliskiren On Oxidative Stress In Isolated Rat Heart

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Plecevic Sasa

2015-09-01

Full Text Available Increased activity of the renin-angiotensin-aldosterone system (RAAS plays a significant role in the development and progression of various cardio-metabolic diseases, such as hypertension, atherosclerosis and heart failure. Aliskiren is the newest antihypertensive drug and the first orally active direct renin inhibitor to become available for clinical use. This study investigated the acute and direct effects of Aliskiren on different parameters of oxidative stress on isolated rat heart. The hearts of male Wistar albino rats (n = 24, 8 per experimental group, age 8 weeks, body mass 180–200 g, were excised and retrogradely perfused according to the Langendorfftechnique at a gradually increasing perfusion pressure (40-120 cmH2O. Markers of oxidative stress (NO2−, TBARS, H2O2 and O2− were measured spectrophotometrically after perfusion with three different concentrations of Aliskiren (0.1 μM, 1 μM, and 10 μM. The results demonstrated possible dose-dependent cardioprotective properties of Aliskiren, particularly with higher CPP. Lipid peroxidation (TBARS levels decreased with the highest dose of Aliskiren and higher CPP, and the same trend was observed in nitrite (NO2− and hydrogen peroxide (H2O2 levels. These findings indicate that the acute effects of Aliskiren do not likely promote the production of reactive oxygen species upon higher pressure with the highest dose. Aliskiren may exert beneficial effects on oxidative stress biomarkers.

Glycogen accumulation in normal and irradiated minced muscle autografts on frog gastrocnemius

International Nuclear Information System (INIS)

Malhotra, R.K.; Kaul, R.; Malhotra, N.

1989-01-01

Alterations induced in glycogen content and phosphorylase activity have been studied in normal and irradiated minced muscle autografts on frog gastrocnemius at days 1, 3, 5, 7, 10, 15 and 30 postgrafting. The changes observed in the glycogen content and phosphorylase activity conform to the degeneration and regeneration phases of muscle repair. An attempt has been made to explain the altered glycogen utilizing capacities of the frog skeletal muscle during its repair and regeneration. (author)

Impaired glymphatic perfusion after strokes revealed by contrast-enhanced MRI: a new target for fibrinolysis?

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Gaberel, Thomas; Gakuba, Clement; Goulay, Romain; Martinez De Lizarrondo, Sara; Hanouz, Jean-Luc; Emery, Evelyne; Touze, Emmanuel; Vivien, Denis; Gauberti, Maxime

2014-10-01

The aim of the present study was to investigate the impact of different stroke subtypes on the glymphatic system using MRI. We first improved and characterized an in vivo protocol to measure the perfusion of the glymphatic system using MRI after minimally invasive injection of a gadolinium chelate within the cisterna magna. Then, the integrity of the glymphatic system was evaluated in 4 stroke models in mice including subarachnoid hemorrhage (SAH), intracerebral hemorrhage, carotid ligature, and embolic ischemic stroke. We were able to reliably evaluate the glymphatic system function using MRI. Moreover, we provided evidence that the glymphatic system was severely impaired after SAH and in the acute phase of ischemic stroke, but was not altered after carotid ligature or in case of intracerebral hemorrhage. Notably, this alteration in glymphatic perfusion reduced brain clearance rate of low-molecular-weight compounds. Interestingly, glymphatic perfusion after SAH can be improved by intracerebroventricular injection of tissue-type plasminogen activator. Moreover, spontaneous arterial recanalization was associated with restoration of the glymphatic function after embolic ischemic stroke. SAH and acute ischemic stroke significantly impair the glymphatic system perfusion. In these contexts, injection of tissue-type plasminogen activator either intracerebroventricularly to clear perivascular spaces (for SAH) or intravenously to restore arterial patency (for ischemic stroke) may improve glymphatic function. © 2014 American Heart Association, Inc.

Ichthyophonus sp. (Ichthyophonae, Ichthyophonida) infection in a South American amphibian, the hylid frog Hypsiboas pulchellus.

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Borteiro, Claudio; Verdes, José Manuel; Cruz, Juan Carlos; Sabalsagaray, María Jesús; Kolenc, Francisco; Martínez Debat, Claudio; Ubilla, Martín

2015-04-01

We report infection by Ichthyophonus sp. in a South American amphibian, the hylid frog Hypsiboas pulchellus in Uruguay. This frog had a large subcutaneous mass over the urostyle and dorsal musculature comprised of parasitic cysts with mild granulomatous inflammation but otherwise appeared healthy.

Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

International Nuclear Information System (INIS)

Tutcu, Semra; Serter, Selim; Kaya, Yavuz; Kara, Eray; Nese, Nalan; Pekindil, Goekhan; Coskun, Teoman

2010-01-01

Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

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Tutcu, Semra [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Serter, Selim, E-mail: serterselim@gmail.co [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Kaya, Yavuz; Kara, Eray [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Nese, Nalan [Department of Pathology, Celal Bayar University, School of Medicine, Manisa (Turkey); Pekindil, Goekhan [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Coskun, Teoman [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey)

2010-08-15

Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

Myocardial 99mTc-sestamibi extraction and washout in hypertensive heart failure using an isolated rat heart

International Nuclear Information System (INIS)

Fukushima, Kenji; Momose, Mitsuru; Kondo, Chisato; Higuchi, Takahiro; Kusakabe, Kiyoko; Hagiwara, Nobuhisa

2010-01-01

Purpose: Myocardial mitochondria are the primary part of energy production for healthy cardiac contraction. And mitochondrial dysfunction would play an important role in progressive heart failure. In the recent years, myocardial washout of 99m Tc-sestamibi [( 99m Tc-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI)] has been introduced to be a potential marker in patients with heart failure. The objective of this study was to clarify MIBI extraction and washout kinetics using isolated perfusion system in hypertension induced model of myocardial dysfunction. Methods: Six-week-old Dahl-salt sensitive rats, allotted to 4 groups; a 5-week high-salt group (5wk-HS), 12-week high-salt group (12wk-HS) and two age-matched, low-salt diet control groups (5wk-LS and 12wk-LS). The rats in 5wk-HS and 12wk-HS groups were fed a high-salt diet (containing 8% NaCl). Cardiac function was examined by echocardiography before removing heart. Hearts were perfused according to the Langendorff method at a constant flow rate, in which 20-min MIBI washin was conducted followed by 25-min MIBI washout. Whole heart radioactivity was collected every sec by an external gamma detector. The myocardial extraction, K 1 (ml/min) and washout rate, k 2 (min -1 ) were generated. Results: High-salt diet groups showed significant high-blood pressure. Echocardiography revealed thickened LV walls in 5wk-HS, and reduced cardiac function in 12wk-HS, compared to each age-matched control group. K 1 showed no significant difference among all groups (5wk-HS: 2.36±1.07, 5wk-control: 2.59±0.28, 12wk-HS: 1.91±0.90, and 12wk-control: 2.84±0.57). k 2 in 5wk-HS was comparable to that in the age matched control group (0.00030±0.00039 vs -0.000010±0.00044), but it was increased remarkably in 18wk-HS compared to the age matched control group (0.0025±0.0011 vs 0.000025±0.000041, P<.01), and 5wk-HS (P<.01). Conclusion: In the course of hypertensive heart disease, MIBI washout was increased in the transitional state

The pathophysiology of heart failure.

Science.gov (United States)

Kemp, Clinton D; Conte, John V

2012-01-01

Heart failure is a clinical syndrome that results when the heart is unable to provide sufficient blood flow to meet metabolic requirements or accommodate systemic venous return. This common condition affects over 5 million people in the United States at a cost of $10-38 billion per year. Heart failure results from injury to the myocardium from a variety of causes including ischemic heart disease, hypertension, and diabetes. Less common etiologies include cardiomyopathies, valvular disease, myocarditis, infections, systemic toxins, and cardiotoxic drugs. As the heart fails, patients develop symptoms which include dyspnea from pulmonary congestion, and peripheral edema and ascites from impaired venous return. Constitutional symptoms such as nausea, lack of appetite, and fatigue are also common. There are several compensatory mechanisms that occur as the failing heart attempts to maintain adequate function. These include increasing cardiac output via the Frank-Starling mechanism, increasing ventricular volume and wall thickness through ventricular remodeling, and maintaining tissue perfusion with augmented mean arterial pressure through activation of neurohormonal systems. Although initially beneficial in the early stages of heart failure, all of these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Treatment strategies have been developed based upon the understanding of these compensatory mechanisms. Medical therapy includes diuresis, suppression of the overactive neurohormonal systems, and augmentation of contractility. Surgical options include ventricular resynchronization therapy, surgical ventricular remodeling, ventricular assist device implantation, and heart transplantation. Despite significant understanding of the underlying pathophysiological mechanisms in heart failure, this disease causes significant morbidity and carries a 50% 5-year mortality. Copyright © 2012 Elsevier Inc. All rights reserved.

Use of olfactory cues by newly metamorphosed wood frogs (Lithobates sylvaticus) during emigration

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Zydlewski, Joseph D.; Popescu, Viorel D.; Brodie, Bekka S.; Hunter, Malcom L.

2012-01-01

Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs (Lithobates sylvaticus) to investigate: (1) the existence of innate (i.e., inherited) directionality, and (2) the use of olfactory cues, specifically forested wetland and natal pond cues during emigration. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction (suggested by previous studies) when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. Animals reared in semi-natural conditions (1500 l cattle tanks) showed a strong avoidance of forested wetland cues in two different experimental settings, although they had not been previously exposed to such cues. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond (cattle tank) water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

Modeling Sexual Selection in Túngara Frog and Rationality of Mate Choice.

Science.gov (United States)

Vargas Bernal, Esteban; Sanabria Malagon, Camilo

2017-12-01

The males of the species of frogs Engystomops pustulosus produce simple and complex calls to lure females, as a way of intersexual selection. Complex calls lead males to a greater reproductive success than what simple calls do. However, the complex calls are also more attractive to their main predator, the bat Trachops cirrhosus. Therefore, as M. Ryan suggests in (The túngara frog: a study in sexual selection and communication. University of Chicago Press, Chicago, 1985), the complexity of the calls lets the frogs keep a trade-off between reproductive success and predation. In this paper, we verify this trade-off from the perspective of game theory. We first model the proportion of simple calls as a symmetric game of two strategies. We also model the effect of adding a third strategy, males that keep quiet and intercept females, which would play a role of intrasexual selection. Under the assumption that the decision of the males takes into account this trade-off between reproductive success and predation, our model reproduces the observed behavior reported in the literature with minimal assumption on the parameters. From the model with three strategies, we verify that the quiet strategy could only coexists with the simple and complex strategies if the rate at which quiet males intercept females is high, which explains the rarity of the quiet strategy. We conclude that the reproductive strategy of the male frog E. pustulosus is rational.

Flecainide attenuates rate adaptation of ventricular repolarization in guinea-pig heart