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K Bendjelid

Publications and source records attributed to K Bendjelid.

14 recordsLinked to original sources

Role of glycolysis in the energy production for the non-mechanical myocardial work in isolated pig hearts.

BACKGROUND: The dissociation of mechanical from non-mechanical energy utilisation can be studied using BDM (2,3-butanedione monoxime), which inhibits the actin-myosin interaction without inhibiting Ca2+ transport. The objective of the present study was to establish if increasing the non-mechanical energy demand of perfused isolated pig hearts by dobutamine stimulation requires glycolysis with increased exogenous glucose uptake. METHODS: Five isolated pig hearts (CTRL) were perfused for 90 min at constant flow (1 ml g(-1) min(-1)) with non-recirculating blood containing 30 mM BDM and 26 MBq/l of fluorine-18 2-fluoro-2-deoxyglucose (IFDG). This was compared with five hearts (DOBU) subjected to the same protocol for the first 30 min and then to dobutamine (1.5 microM) for the following 30 min and dobutamine (4 microM) for the last 30 min. Five other isolated hearts were perfused as for the DOBU group but without BDM (CTRLDOBU). Using a clinical PET scanner, glucose uptake was assessed by estimating 18FDG uptake using linear regression. The slope variations were compared using a global test of coincidence. RESULTS: Heart rate was at 100 +/- 2 b.p.m. in the CTRL group and at 180 +/- 7 b.p.m. in the DOBU group. 18FDG uptake was homogeneous within the whole myocardium and we observed a linear and regular increase in both the CTRL and DOBU groups (p, NS). In the CTRLDOBU group, 18FDG uptake was also homogeneous within the whole myocardium, but slopes of 18FDG uptake during dobutamine perfusion were higher than without dobutamine. CONCLUSION: In blood-perfused isolated pig hearts, exogenous glucose is not necessarily required when non-mechanical energy is increased by dobutamine stimulation. These findings suggest that ATP derived from glycolysis is not necessary to preserve myocardial Ca2+ transport during beta-adrenergic stimulation.

Adrenergic beta-Agonists↗

Slaughterhouse blood as a perfusate for studying myocardial function under ischemic conditions.

Metabolic studies using the in vitro non-recirculating blood-perfused isolated heart model require large volumes of blood. The present study was designed to determine whether heterologous pig blood collected from a slaughterhouse can be used as perfusate for isolated pig hearts perfused under aerobic and constant reduced flow conditions. Eight isolated working pig hearts perfused for 90 min at a constant flow of 1.5 ml g(-1) min(-1) with non-recirculated blood diluted with Krebs-Henseleit bicarbonate buffer at a hematocrit of 23% were compared to eight hearts subjected to the same protocol but perfused only with Krebs-Henseleit bicarbonate buffer solution. Hearts were paced at 100 bpm and subjected to aerobic perfusion at 38 degrees C. Hearts were weighed before perfusion and at the end of the experiment and the results are reported as percent weight gain (mean +/- SD). Comparisons between groups were performed by the Student t-test (P<0.05). After 90 min of perfusion with modified Krebs-Henseleit, perfused hearts presented a larger weight gain than blood-perfused hearts (39.34 +/- 9.27 vs 23.13 +/- 5.42%, P = 0.003). Left ventricular end-diastolic pressure was higher in the modified Krebs-Henseleit-perfused group than in the blood group (2.8 +/- 0.4 vs 2.3 +/- 0.3 mmHg, respectively, P = 0.01). We conclude that heterologous blood perfusion, by preserving a more physiological myocardial water content, is a better perfusion fluid than modified Krebs-Henseleit solution for quantitative studies of myocardial metabolism and heart function under ischemic conditions.

Animals↗

[Cardiovascular manifestations of systemic elastorrhexis].

INTRODUCTION: Systemic elastorrhexis or Grönblad-Strandberg-Touraine syndrome is a rare inherited disease characterized by a generalized elastic tissue dysplasia and polymorphic clinical features, with the main tissues affected being cutaneous, ocular and arterial. CURRENT KNOWLEDGE AND KEY POINTS: Usual cardiovascular complications of this entity include ischemic heart disease, renovascular hypertension and atherosclerotic peripheral vascular disease. Some cases of restrictive cardiomyopathies and valvular disease have been reported. Coronary artery disease, often with early onset, is seen in approximately 20% of cases. FUTURE PROSPECTS AND PROJECTS: This review of the literature concerning a rare cause of cardiopathy underlines the need to search for underlying elastorrhexis in the clinical setting of early onset and severe coronary artery disease or arteriopathy, especially in the absence of vascular risk factors. This hereditary disease has been traced to chromosome 16p13.1 and may in the future be easily diagnosed, bypassing the need for cutaneous biopsy.

Cardiovascular Diseases↗

[Acute dissection of the ascending thoracic aorta complicated by myocardial infarct: an unavoidable diagnostic pitfall?].

BACKGROUND: Acute dissection of the aorta during myocardial infarction is exceptional. In such cases, fibrinolysis can be fatal. CASE REPORTS: A 63-year-old woman with a history of hypertension was referred to our intensive care unit with the diagnosis of early stage inferior myocardial infarction. Thrombolysis was instituted and the patient rapidly developed cardiovascular collapse with global heart failure. Coronarography was attempted to revascularize the occluded coronary artery but the coronary arteries could not be catheterized. An aortography was performed and gave the diagnosis of De Bakey type I dissection of the aorta. The patient died from cardiac arrest after a phase of low cardiac output. DISCUSSION: This case illustrates how myocardial infarction can complicate or mask acute dissection of the aorta. It also raises the question of transthoracic echocardiography prior to institution of fibrinolysis.

Aortic Dissection↗

[Mid-term prognostic value of plasma heavy-chain myosin in thrombolysed myocardial infarction].

Plasma myosin heavy chain assay, which can be easily performed during the acute phase of myocardial infarction, is a recent method allowing quantitative assessment of the extent of infarction. However, to our knowledge, its prognostic value has not been studied in contrast with serum myosin light chain assay. We monitored the state of health of 40 patients (including 37 men with a mean age of 56 years) for two years after a first myocardial infarction, thrombolized during the acute phase. Their survival (mortality) and the development of "cardiac events" (MI, angina, sudden death, etc.) were evaluated at 2 years. The results observed at 2 years were correlated with the initial plasma myosin assay results and other direct and indirect methods of assessment of the extent of infarction, performed during the acute phase of myocardial infarction (cardiac enzymes, contrast angiography). The main result of this study is the demonstration that an unusual plasma myosin release kinetic (complex appearance) is predictive for the medium-term development of heart failure (p = 0.04) and/or destabilization of coronary insufficiency (p = 0.02). These results need to be emphasized, as with only 5 serum myosin assays performed over a 10-day period, it seems possible to identify a group of patients at high risk of medium-term complications, who possess a complex release kinetic during the acute phase of myocardial infarction and a value for area under the curve greater than 10.470 microliters U/L (cut-off value, p = 0.043).

Acute Disease↗

[Anuric renal insufficiency caused by bilateral ureteral lithiasis].

A 73-year-old man was admitted to the ICU for anuria. He reported no history of urinary disease. The abdominal roentgenography and two echographies showed an empty urinary bladder, a right ureteral calculus without dilatation of the urinary tract. Computed tomography demonstrated the presence of a left ureteral stone. Bilateral retrograde ureteroscopy and drainage allowed a rapid recovery. When the abdominal roentgenography and echography cannot explain the occurrence of anuria, the computed tomography, or better the helical CT, can demonstrate the presence of otherwise unrecognized calculi.

Acute Kidney Injury↗

Design of an isolated pig heart preparation for positron emission tomography and magnetic resonance imaging.

RATIONALE AND OBJECTIVES: Validation of new positron emission tomography (PET) tracers or magnetic (MR) imaging contrast agents is based on isolated rodent heart preparations. The use of larger animals could provide a more direct validation using the devices used for humans. METHODS: An isolated pig heart preparation has been developed and adapted to the technical constraints of whole body PET and MR imaging. This preparation could be used either in the Langendorff or working mode after selective cannulation of both coronary arteries. RESULTS: The authors showed that quantification of regional kinetics of PET tracers was possible using this preparation by measuring fluorine-18-labeled deoxyglycose (18FDG) kinetics in remote and ischemic territories. Experiments using MR imaging contrast agents, for myocardial perfusion, demonstrated the ability of this preparation to accurately validate these contrast agents over a wide range of flow rates. CONCLUSIONS: An isolated pig heart preparation could be developed to fulfill the constraints of PET and MR imaging, and proved useful for the study of the distribution of different tracers or contrast media developed for functional cardiac imaging in humans.

Animals↗