Biomedical subjects

M Delorme

Publications and source records attributed to M Delorme.

15 recordsLinked to original sources

PubMed1996

Nitrogen and energy requirements of the short-tailed fruit bat (Carollia perspicillata): fruit bats are not nitrogen constrained.

Nitrogen (N) and energy (E) requirements were measured in adult Carollia perspicillata which were fed on four experimental diets. Bats ate 1.3-1.8 times their body mass.day-1 and ingested 1339.5-1941.4 kJ.kg-0.75.day-1. Despite a rapid transit time, dry matter digestibility and metabolizable E coefficient were high (83.3% and 82.4%, respectively), but true N digestibility was low (67.0%). Mass change was not correlated with E intake, indicating that bats adjusted their metabolic rate to maintain constant mass. Bats were able to maintain constant mass with digestible E intake as low as 1168.7 kJ.kg-0.75.day-1 or 58.6 kJ.. Metabolic fecal N and endogenous urinary N losses were 0.87 mg N.g-1 dry matter intake and 172.5 mg N.kg-0.75.day-1, respectively, and bats required 442 mg N.kg-0.75.day-1 (total nitrogen) or 292.8 mg N.kg-0.75.day-1 (truly digestible nitrogen) for N balance. Based on E and N requirements and digestibilities, it was calculated that non-reproductive fruit bats were able to meet their N requirements without resorting to folivory and without over-ingesting energy. It was demonstrated that low metabolic fecal requirements allowed bats to survive on low-N diets.

Animals↗

PubMed1995

alpha 2-Macroglobulin remains as important as antithrombin III for thrombin regulation in cord plasma in the presence of endothelial cell surfaces.

Infants and children rarely develop thrombotic complications compared with adults, suggesting that there are protective mechanisms in place for the young. Because endothelial cell surfaces regulate thrombin formation and inhibition, we compared thrombin regulation by human umbilical vein endothelial cell surfaces exposed to defibrinated cord and adult plasmas. After activation by either 10% activated partial thromboplastin reagent (strong activator) or coagulant phospholipids (weak activator) the following were measured: free thrombin, thrombin bound to antithrombin III (ATIII), heparin cofactor II, alpha 2-macroglobulin (alpha 2M), and prothrombin concentration. Free thrombin activity was expressed as remaining activity, after subtraction of thrombin-alpha 2M activity. After 10% activated partial thromboplastin reagent, 100% of prothrombin was consumed and significant amounts of thrombin generated by 2 min. Cord plasma generated significantly less thrombin than adult plasma, reflecting the lower initial plasma concentration of prothrombin. correspondingly, concentrations of thrombin inhibitor complexes were significantly greater in adult plasma than in cord plasma. After coagulant phospholipids, 50% of prothrombin was consumed and negligible thrombin activity measured for both adult and cord plasma. Similar amounts of thrombin inhibitor complexes were formed. ATIII was the predominant inhibitor of thrombin in adult plasma, whereas alpha 2M was as important as ATIII in cord plasma for both activators. When cord plasma concentrations of ATIII were increased to adult values, the proportion complexed to alpha 2M decreased. We conclude that on human umbilical vein endothelial cells, the capacity to generate thrombin is decreased in adult and cord plasmas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Inhibition of thrombin by antithrombin III and heparin cofactor II in vivo.

The critical role of thrombin in the pathogenesis of venous and arterial thrombosis, and the effectiveness of glycosaminoglycans as antithrombotic drugs are well known. Antithrombin III is a major inhibitor of thrombin and augmentation of its inhibitory actions by heparin is the basis for the clinical uses of heparin. Recent clinical and experimental studies have demonstrated that another glycosaminoglycan, dermatan sulfate, is an effective antithrombotic drug. Dermatan sulfate catalyses the inhibition of thrombin by heparin cofactor II. The concentrations of heparin cofactor II are higher in the plasmas of individuals with congenital antithrombin III deficiency and pregnant women than controls. The role of heparin cofactor II as a physiologic thrombin inhibitor is unknown. Enzyme-linked immunosorbent assays were used to quantify thrombin-heparin cofactor II and thrombin-antithrombin III endogenous to the plasmas of adult antithrombin III-Hamilton deficient subjects, their siblings with normal antithrombin III levels, pregnant women at term and 3 to 5 days after delivery. Both thrombin-antithrombin III and thrombin-heparin cofactor II complexed with vitronectin were detected in all the plasmas. Significantly, the concentrations of thrombin-heparin cofactor II-vitronectin were higher in the plasmas of congenital antithrombin III deficient subjects and in pre- and post-delivery plasmas than those of normal subjects. In addition, the concentrations of thrombin-heparin cofactor II decreased 3 to 5 days after delivery, reflecting the disappearance of the catalytically active dermatan sulfate elaborated by the placenta. Thus, heparin cofactor II normally inactivates thrombin in vivo, with its role increasing in conditions associated with high levels of heparin cofactor II and/or dermatan sulfate.

Adult↗

PubMed1995

[Latex hypersensitivity: a foreseeable accident?].

This paper describes another case of severe anaphylactic reaction due to allergy to natural rubber during anaesthesia in a child without known risk factors. The day after surgery the child reported that he experienced a few months ago an impressive skin reaction of both face and lips after inflating a latex balloon. It is suggested to try to detect latex allergy during the preoperative visit in all patients by including questions about latex sensitivity such as previous skin reactions or respiratory symptoms after wearing latex gloves or after inflating toy balloons. Patients in whom latex sensitivity is suspected should be tested appropriately in order to perform the planned surgery in a latex-free environment.

Adolescent↗

PubMed1995

Circulating dermatan sulfate and heparan sulfate/heparin proteoglycans in children undergoing liver transplantation.

The liver produces dermatan sulfate (DS), heparan sulfate (HS) and heparin glycosaminoglycans (GAG) and in the presence of hepatic disease, tissue levels of the DS GAG increase dramatically. We hypothesized that in children undergoing liver transplantation plasma levels of DS would be increased. Plasma from children undergoing liver transplantation were tested preoperative, intra operative and post operative at 24-48 h, and 1-3 weeks. Fluctuating levels of DS, HS and heparin anticoagulant activity were detected at all timepoints. The anticoagulant activity was purified and gel chromatography of the material displayed a mean Mr 110,000 D. Reductive elimination decreased the mean Mr 24,000 D indicating the activity resides on a proteoglycan (PG). The purified material was subjected to further chromatography and two peaks of anticoagulant activity resolved, compatible with at least two separate PGs, one with DS GAG chains and the additional PG(s) with HS and heparin GAG chains.

Adolescent↗

PubMed1994

[The impact of suicide on the caregiver].

Suicide ("the killing of one's self") raises one crucial question: what does the manifest desire of death bring out in oneself and in others? For those providing care and support who are confronted with the voluntary death of a client or patient, the question is particularly difficult to address. Using the story of a suicide in an institution, the authors reveal the nature of defense mechanisms at play within the group of caregivers. Whether it be a traumatic daze, denial, guilt or depression, these individual and collective reactions to the event hinder the mourning process and threaten cohesion within the institution. Members of an "institution in crisis" must try to relieve their tensions by refraining from withdrawal, banalities, being haunted by suicide and implementing pseudo-solutions. The purpose of such an exercise is especially to avoid the cancellation or displacement of necessary thought process about the origins, implications and consequences of a suicide taking place within an institution. The authors discuss the founding principles and guidelines for group exploration of these phenomena. Without this coming-to-terms with the crisis, the authors point out that the institution could find itself in a rut where discussion focuses only on when and where things went wrong, and how it turned its back on a suffering patient.

Adult↗

PubMed1993

[Anesthesia in the management of pyloric stenosis. Evaluation of the combination of propofol-halogenated anesthetics].

This study was aimed at evaluating haemodynamic changes during an anaesthetic sequence for full stomach, using propofol as induction agent and volatile anaesthetics for maintenance of anaesthesia in infants scheduled for surgical cure of hypertrophic pyloric stenosis. After correction of preoperative blood electrolyte and metabolic disturbances with appropriate i.v. hydrating solutions, anaesthesia was induced with propofol and suxamethonium. Infants were divided in two groups according to the volatile anaesthetic agent used for maintenance of anaesthesia after tracheal intubation: halothane (n = 16) or isoflurane (n = 15). The two groups were identical regarding weight (4.28 +/- 0.6 vs 4.14 +/- 0.76 kg), age (1.6 +/- 0.9 vs 1.5 +/- 0.6 months), preinduction heart rate (155 +/- 22 vs 151 +/- 22 b.min-1) and systolic-diastolic arterial pressure (96 +/- 18/58 +/- 12 vs 105 +/- 16/67 +/- 15 mmHg). Propofol and suxamethonium doses were identical, 3.9 +/- 1 mg.kg-1 and 1.3 +/- 0.6 mg.kg-1 respectively in halothane group, vs 4.3 +/- 0.8 mg.kg-1 and 1.3 +/- 0.4 mg.kg-1 in isoflurane group. Heart rate did not change after induction of anaesthesia, while arterial blood pressure decreased significantly (p < 0.001). However, blood pressure remained within the normal range for age throughout the procedure. Mean duration of surgery was shorter in halothane group (64 +/- 16 vs 79 +/- 17 min, p < 0.05), however time-interval from the end of surgery to tracheal extubation (12 +/- 6 vs 15 +/- 8 min) was short and identical in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗

PubMed1992

An anticoagulant dermatan sulfate proteoglycan circulates in the pregnant woman and her fetus.

Investigation of the in vitro ability of plasma from pregnant women to inhibit exogenous thrombin (25 nM) demonstrated that heparin cofactor II inhibited more thrombin (3.0 +/- 0.7 nM, mean +/- SD) than plasma from women 3-5 d postpartum (1.9 +/- 0.5 nM) or plasma from nonpregnant adults (1.5 +/- 0.4 nM). Levels of heparin cofactor II were only slightly increased over normal in both pregnant and postpartum women and did not account for the observed increase in thrombin bound to heparin cofactor II. Assay of pregnancy plasma for dermatan sulfate anticoagulant activity demonstrated the presence of activity equivalent to 0.23 +/- 0.02 micrograms/ml of porcine mucosal dermatan sulfate. This activity could not be demonstrated in normal adult plasma or plasma from women on the contraceptive pill. The mass of dermatan sulfate in pregnancy and umbilical cord plasmas was increased over adult control plasma by 0.20 micrograms/ml (53%) and 0.29 micrograms/ml (76%), respectively. The glycosaminoglycan-containing fraction of plasma was isolated and an assay for anticoagulant dermatan sulfate confirmed its presence in both pregnancy and cord plasmas but minimal activity in adult plasma. Gel chromatography of isolated fractions from both pregnancy and cord plasmas revealed a polydisperse, active species with apparent Mr 150,000 D. Reductive elimination decreased the apparent Mr of the active species on gel chromatography to 31,000 D for cord and 21,000 D for pregnancy products. This confirmed the presence of an anticoagulant active dermatan sulfate proteoglycan circulating in the plasmas of pregnant women at term and fetuses at delivery.

Anticoagulants↗

PubMed1984

[Early treatment of labiopalatine clefts. Their management and anesthetic problems].

The authors review a new therapeutic chronology for cleft lip and palate developed by R. Malek and J. Psaume. This involves very early treatment requiring orthopaedic or surgical procedures in small infants aged one to three months. These have been made possible by progress in techniques and equipment from both a surgical and orthopaedic standpoint as well as in anaesthesia. They describe the organisation of anaesthesia and analyse their results, showing that this is a simple anaesthetic, free of risk. The postoperative course is simple. The child is fed normally and is discharged on the 2nd or 3rd postoperative day.

Anesthesia↗

PubMed1983

A simple classification of the risk in cardiac surgery.

A new risk classification for patients undergoing cardiac surgery has been used for the last two years by the anaesthesiologists of the Montreal Heart Institute. The following factors known to be associated with a greater operative morbidity and mortality were selected: (1) poor left ventricular function, (2) congestive heart failure, (3) unstable angina or recent (less than 6 weeks) myocardial infarction, (4) age over 65 years, (5) severe obesity (Body Mass Index greater than 30), (6) reoperation, (7) emergency surgery, (8) other significant or uncontrolled systemic disturbances. Patients with none of the above factors were classified as normal risks; those presenting with one of those selected factors were classified as increased risks, and those with more than one factor were said to carry a high risk. In a prospective study of 500 consecutive open-heart surgery patients classified according to this method, we found that the operated population at normal risk (50 per cent of cases) had a mortality of 0.4 per cent, the patient group with increased risk (32 per cent of cases) had a mortality of 3.1 per cent, and the high risk group (18 per cent of cases) had a 12.2 per cent mortality. Furthermore, 50 deaths following open-heart surgery were assessed retrospectively using the classification; 58 per cent of these patients were classified as high risk, 34 per cent had an increased risk, and only eight per cent were found to be in the normal risk group. Thus, this new risk classification has proven to be a reliable and useful tool for preoperative assessment of patients undergoing open-heart surgery and for teaching purposes.

Age Factors↗

PubMed1983