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Biomedical subjects

D Moreau

Publications and source records attributed to D Moreau.

At least 55 records · Page 3Linked to original sources
PubMed1996

Myocardial ischemia and in vitro mitochondrial metabolic efficiency.

The purpose of this study was to evaluate the oxidative capacities and the rate of energy synthesis in isolated mitochondria extracted from normal and post-ischemic myocardium. Isolated rat hearts were perfused according to the working mode with a Krebs Heinseleit buffer containing glucose (11 mM), insulin (10 IU/l) and caprylic acid (25 microM). After a 15 min perfusion in normoxic conditions, the hearts were subjected to a 20 min local zero-flow ischemia followed by a 20 min reperfusion. During the perfusion, the aortic and coronary flows, the aortic pressure and the electrocardiogram were monitored. At the end of the reperfusion period, the non-ischemic and ischemic zones (NIZ and IZ, respectively) were separated and the mitochondria were harvested from each zone. The oxygen uptake and the rate of energy production of the NIZ and IZ mitochondria were then assessed with palmitoylcarnitine as substrate in 2 buffers differing in their free calcium concentration (0.041 and 0.150 microM). Ischemia provoked a 50% reduction of coronary and aortic flows. The reperfusion of the IZ allowed the partial recovery of coronary flow, but the aortic flow decreased beneath its ischemic value because of the occurrence of severe arrhythmias, stunning and probably hibernation. The IZ mitochondria displayed a lower rate of oxygen consumption, whatever the buffer free calcium concentration. Conversely, their rate of energy production was increased, indicating that their metabolic efficiency was improved as compared to NIZ mitochondria. This might be due to the mitochondrial calcium overload persisting during reperfusion, to the activation of the inner membrane Na+/Ca2+ exchange and to a significant mitochondrial swelling. On the other hand, the presence of an elevated free calcium concentration in the respiration buffer provoked some energy wasting characterized by a constant AMP production. This was attributed to some accumulation of acetate and the activation of the energy-consuming acetylCoA synthetase. In conclusion, ischemia and reperfusion did not alter the membrane integrity of the mitochondria but improved their metabolic efficiency. Nevertheless, these in vitro results can not reflect the mitochondrial function in the reperfused myocardium. The mitochondrial calcium overload reported to last during reperfusion in the cardiomyocytes might mimic the free calcium-induced reduction of metabolic efficiency observed in vitro in the present study. The resulting energy wasting might be responsible for the contractile abnormalities noticed in the reperfused myocardium.

Adenosine Triphosphate↗
PubMed1996

Psychiatric diagnosis in child and adolescent suicide.

BACKGROUND: The age, sex, and ethnic distribution of adolescents who commit suicide is significantly different from that of the general population. The present study was designed to examine psychiatric risk factors and the relationship between them and demographic variables. METHODS: A case-control, psychologic autopsy study of 120 of 170 consecutive subjects (age, <20 years) who committed suicide and 147 community age-, sex-, and ethnic-matched control subjects who had lived in the Greater New York (NY) area. RESULTS: By using parent informants only, 59% of subjects who committed suicide and 23% of control subjects who met DSM-III criteria for a psychiatric diagnosis, 49% and 26%, respectively, had had symptoms for more than 3 years, and 46% and 29%, respectively, had had previous contact with a mental health professional. Best-estimate rates, based on multiple informants for these parameters, for suicides only, were 91%, 52%, and 46%, respectively. Previous attempts and mood disorder were major risks factors for both sexes; substance and/or alcohol abuse was a risk factor for males only. Mood disorder was more common in females, substance and/or alcohol abuse occurred exclusively in males (62% of 18- to 19-year-old suicides). The prevalence of a psychiatric diagnosis and, in particular, substance and/or alcohol abuse increased with age. CONCLUSION: A limited range of diagnoses--most commonly a mood disorder alone or in combination with conduct disorder and/or substance abuse--characterizes most suicides among teenagers.

Adolescent↗
PubMed1996

Unusual presentation of a tuberculous peritonitis in a patient with concomitant AIDS and liver cirrhosis.

We report a case of tuberculous peritonitis in a patient with concomitant HIV infection and liver cirrhosis. A 50-year-old man with viral B and delta liver cirrhosis and AIDS was diagnosed with spontaneous Escherichia coli peritonitis and successfully treated with beta-lactamins. Three months later, ascites reappeared and Mycobacterium tuberculosis was identified in peritoneal fluid cultures. The triple antituberculosis regimen was adjusted to his level of liver failure but the patient died of hepatic encephalopathy. Concomitant HIV infection and liver cirrhosis favour tuberculous peritonitis but they also make its diagnosis extremely difficult. Considering the poor prognosis of this infection when untreated, tuberculous peritonitis should be systematically suspected in such patients.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Effects of aldosterone and spironolactone on the isolated perfused rat heart.

Aldosterone antagonists are used in the treatment of hypertension. However, the cardiac influences of aldosterone and its antagonists have not been thoroughly investigated. In the present study, we investigated the effects of aldosterone and spironolactone on an isolated rat working heart model. Aldosterone (10(-8) mol/l) decreased the coronary flow and increased aortic flow and cardiac output. Spironolactone (10(-5) mol/l) inhibited these effects. These results suggest that aldosterone directly influences the cardiac function. Spironolactone appears able to inhibit the adverse cardiac effects of aldosterone. The exact mechanisms remain to be elucidated, but the early effects of aldosterone under our experimental conditions on the functional parameters of the heart suggest a nongenomic response including activation of receptors different from those transmitting genomic steroid actions.

Aldosterone↗
PubMed1996

Vitamin status of healthy subjects in Burgundy (France).

A nutrition survey was conducted in Burgundy (France) with a population sample of 337 middle-aged and healthy subjects (157 males and 180 females) recruited at a health examination center in 1985-1986. The status of beta-carotene, thiamin, riboflavin, folate, vitamin B6, B12, C, A, D, and E was assessed by means of 7-day food records and biochemical studies. Results were compared with two other recent nutritional surveys conducted in France: ESVITAF (control group only) and Val de Marne surveys. The dietary information collected for each subject was compared to the 1992 French Recommended Dietary Allowances (FRDA). Dietary vitamin intakes were higher in males than in females. Low vitamin intakes (< 1/2 FRDA) were found in 5% of males and 7% of females for thiamin, in 11% of males and 28% of females for vitamin B6, in 6% of males and 3% of females for vitamin C, in 87% of males and 91% of females for vitamin D, and in 8% of males and 13% of females for vitamin E. No subject had a vitamin intake < 1/2 FRDA for riboflavin, folate, vitamins A and B12. ESVITAF and Val de Marne studies also show low vitamin intakes for vitamin B6, thiamin, riboflavin, vitamins D and E. Biochemical status was examined using erythrocyte enzyme function and blood vitamin levels. The percent of subjects with deficient biochemical values was high for vitamin B6 (15% of all males and 20% of all females), and vitamin D (13% of all males, and 15% of all females). With regard to thiamin, riboflavin, vitamin C, folate, vitamin B12, vitamin A, and vitamin E, < 5% of subjects had values in the range of major vitamin deficiency. However, in both genders, except for vitamin C and vitamin A (only for females), low values corresponding to a moderate risk of vitamin deficiency was high for most vitamins. The incidence of a severe deficient vitamin status for thiamin and riboflavin was higher in Val de Marne than in Burgundy, or ESVITAF. In Val de Marne, the probability of a moderate risk of vitamin deficiency was high for thiamin, riboflavin, vitamin B6, vitamin A and vitamin E. Our results (as other studies performed in France and in other industrialized countries) raise the issue of the health significance of marginally deficient vitamin status.

Adolescent↗
PubMed1996

Workflow computing. Improving management and efficiency of pathology diagnostic services.

Traditionally, information technology in health care has helped practitioners to collect, store, and present information and also to add a degree of automation to simple tasks (instrument interfaces supporting result entry, for example). Thus commercially available information systems do little to support the need to model, execute, monitor, coordinate, and revise the various complex clinical processes required to support health-care delivery. Workflow computing, which is already implemented and improving the efficiency of operations in several nonmedical industries, can address the need to manage complex clinical processes. Workflow computing not only provides a means to define and manage the events, roles, and information integral to health-care delivery but also supports the explicit implementation of policy or rules appropriate to the process. This article explains how workflow computing may be applied to health-care and the inherent advantages of the technology, and it defines workflow system requirements for use in health-care delivery with special reference to diagnostic pathology.

Ambulatory Care↗
PubMed1995

Effects of electromyostimulation and strength training on muscle soreness, muscle damage and sympathetic activation.

Electromyostimulation (EMS) is known to develop muscular strength and hypertrophy. The aim of this study was to compare EMS exercise-induced damage with concentric (CONC) exercise-induced damage. Twelve male athletes were randomly assigned to concentric exercise (five sets of 6 voluntary contractions) or to EMS (30 contractions of 6 s duration, 20 s rest between contractions) on day 0 (D0). The load was 80% of the maximal isometric force. Criterion measures of plasma creatine kinase (CK) activity and lactate dehydrogenase (LDH) activity, and subjective ratings of muscle soreness and urinary catecholamines, were assessed 1 day before and for 3 days after exercise. Among the members of the EMS group, there were significant increases in catecholamine urinary excretion, especially adrenaline (on days D+2 and D+3), plasma CK activity (on day D+2) and plasma LDH activity (on days D+1 and D+2). The changes among the members of the CONC group were smaller and no significant difference was noted. Muscular soreness was greatest in the EMS group, with the peak occurring on day D+2. Comparisons of enzyme release, muscular soreness and urinary catecholamines suggest that EMS induces myofibre membrane damage and a significant increase in sympathetic nervous activity.

Adult↗
PubMed1995

Can penicillins and other beta-lactam antibiotics be used to treat tuberculosis?

An increase in the number of tuberculosis cases caused by multiple-drug-resistant strains of Mycobacterium tuberculosis has stimulated search for new antituberculous agents. Beta-lactam antibiotics, traditionally regarded as ineffective against tuberculosis, merit consideration. Four major penicillin-binding proteins (PBPs) with approximate molecular sizes of 94, 82, 52, and 37 kDa were detected by fluorography of [3H]penicillin-radiolabeled membrane proteins prepared from M. tuberculosis H37Ra. The presence of membrane-associated beta-lactamase precluded the use of membranes for assaying the binding affinities of beta-lactam antibiotics. Therefore, ampicillin affinity chromatography was used to purify these four PBPs from crude membranes in order to assay the binding affinities of beta-lactam antibiotics. Ampicillin, amoxicillin, and imipenem, beta-lactam antibiotics previously reported to be active in vitro against M. tuberculosis, bound to M. tuberculosis PBPs at therapeutically achievable concentrations. Binding of the 94-, 82-, and 52-kDa PBPs, but not the 37-kDa PBP, was associated with antibacterial activity, suggesting that these PBPs are the critical targets. Studies of mycobacterial cell wall permeability, which was assayed with a panel of reference cephalosporins and penicillins with different charge positivities, indicated that the rate of penetration of beta-lactam antibiotics to the target PBPs could not account for resistance. Resistance could be reversed with the beta-lactamase inhibitors clavulanate or sulbactam or could be circumvented by the use of a beta-lactamase-stable drug, imipenem, indicating that mycobacterial beta-lactamase, probably in conjunction with slow penetration, is a major determinant of M. tuberculosis resistance to beta-lactam antibiotics. These findings confirm in vitro data that M. tuberculosis is susceptible to some beta-lactam antibiotics. Further evaluation of these drugs for the treatment of tuberculosis in animal models and in clinical trials is warranted.

Animals↗
PubMed1995

The architecture of a distributed medical dictionary.

Exploiting high-speed computer networks to provide a national medical information infrastructure is a goal for medical informatics. The Distributed Medical Dictionary under development at Baylor College of Medicine is a model for an architecture that supports collaborative development of a distributed online medical terminology knowledge-base. A prototype is described that illustrates the concept. Issues that must be addressed by such a system include high availability, acceptable response time, support for local idiom, and control of vocabulary.

Artificial Intelligence↗
PubMed1994

Influence of the phospholipid n-6/n-3 polyunsaturated fatty acid ratio on the mitochondrial oxidative metabolism before and after myocardial ischemia.

The influence of dietary n-6 and n-3 polyunsaturated fatty acids (PUFA) on heart pump function and mitochondrial energy metabolism was investigated before and after ischemia. Weanling male Wistar rats were fed for 8 weeks a diet containing either 10% of sunflower seed oil (SSO group) or 10% of a 1:1 (w/w) mixture of fish oil and sunflower seed oil (FO group). The hearts were perfused according to the working mode for 15 min with a Krebs-Henseleit medium containing glucose (11 mM), insulin (10 IU/L) and caprylic acid (25 microM). They were then either maintained in normoxic conditions (70 min) or subjected to a global no-flow normothermic ischemia (20 min) followed by reperfusion (50 min). The aortic and coronary flows were monitored at 5-min intervals. The lactate dehydrogenase (LDH) release in the coronary effluent was evaluated in the control hearts and during ischemia/reperfusion. At the end of the perfusion, two subpopulations of mitochondria were prepared from each heart, by either mechanical or enzyme extraction (ME and EE mitochondria, respectively). The succinate dehydrogenase (SDH) activity was evaluated. Furthermore, the respiration parameters were assessed with either glutamate (20 mM) or palmitoylcarnitine (25 microM) as substrate. Substituting sunflower seed oil by fish oil in the diet provoked a large decrease in the n-6/n-3 PUFA ratio of cardiac phospholipids. The n-3 PUFA enrichment did not alter the coronary and aortic flows nor the LDH release in physiological conditions. Conversely, during post-ischemic reperfusion, the increased amount of n-3 PUFA improved the recovery of aortic flow and decreased the LDH release, without affecting significantly the coronary flow. In ME and EE mitochondria, the phospholipid n-6/n-3 PUFA ratio was similarly modified by the dietary manipulations. The analysis of total cardiac SDH activity suggested an ischemia-induced oedema, of similar magnitude in the two dietary groups. However, neither dietary manipulations nor ischemia influenced the mitochondrial extraction. Similarly, the parameters of glutamate oxidation were also unaffected. Conversely, with palmitoylcarnitine, post-ischemic reperfusion induced a decrease in both state III respiration rate and energy production which were more important in the EE mitochondria of the SSO group. These results suggest that the recovery of mitochondrial energy metabolism and myocardial pump function during reperfusion may be improved in n-3 PUFA-rich hearts. This could be related to a lower injury in n-3 PUFA-rich membranes. Since cardiac function in physiological conditions was not affected by the diet, fish oil could be considered as a beneficial factor to limit heart injury during ischemia and reperfusion.

Animals↗
PubMed1994

Modification of interpersonal psychotherapy with depressed adolescents (IPT-A): phase I and II studies.

OBJECTIVE: To test the acceptability and efficacy of interpersonal psychotherapy for depressed adolescents (IPT-A). METHOD: In phase I, therapeutic methods were explored and refined in a small sample of depressed adolescents (n = 5). In phase II, 14 depressed adolescents entered a 12-week open clinical trial of IPT-A; after independent evaluation. Subjects were assessed using a semistructured diagnostic interview, self-report, and clinician-administered instruments, at six time points: evaluation week, and weeks 0, 2, 4, 8, and 12. RESULTS: In phase I, treatment was modified to meet the needs of an adolescent population and was standardized in a treatment manual. The results of phase II indicated a significant decrease in adolescents' depressive symptomatology and symptoms of psychological and physical distress, as well as a significant improvement in functioning over the course of treatment. At termination, none of the subjects met DSM-III-R criteria for any depressive disorder. CONCLUSIONS: IPT-A appears to be a promising therapy for depressed adolescents. However, because of the limitations of the current study, a larger randomized controlled clinical trial is still needed to test its efficacy.

Adolescent↗