Search PubMed⌕ Search

Biomedical subjects

M Gilbert

Publications and source records attributed to M Gilbert.

At least 163 records · Page 9Linked to original sources
PubMed1990

The effects of phenylbutazone on the morphology and prostaglandin concentrations of the pyloric mucosa of the equine stomach.

Phenylbutazone, a nonsteroidal anti-inflammatory drug known to produce gastric ulcers, was administered intravenously (13.46 mg/kg body weight) daily to 12 horses. Horses were euthanatized daily after 24, 48, 72, and 96 hours following the initial injection. Eight untreated horses served as controls. Small multifocal pyloric erosions were seen after 24 hours and then progressed in severity over time. The erosions were characterized by sloughing of the surface epithelium, subepithelial bleb formation, necrosis of the lamina propria, degeneration of the walls of subsurface capillaries, and microthrombosis of the capillaries of the pyloric mucosa. Large numbers of neutrophils with abundant fibrin and cellular debris were present at the erosion sites. Eroded pyloric mucosa and adjacent macroscopically intact mucosa were examined ultrastructurally. In both the macroscopically eroded mucosa and multifocally in the adjacent macroscopically uneroded mucosa, there was cellular swelling of the endothelium, pericytes, and smooth muscle cells of arterioles. In capillaries and post-capillary venules, the endothelium ranged from swollen to lysed and necrotic. Extensive extravasation of erythrocytes and edema were seen. These lesions were not seen in the control horses. Phenylbutazone produces a microvascular injury that is associated with the formation of pyloric erosions in horses. The pyloric mucosa of six horses was assayed for prostacyclin and prostaglandin E2 at 48 and 96 hours following the initial injection. There was no statistically significant difference between prostaglandin concentrations in the mucosa of control and treated horses. It was concluded that there was little correlation between pyloric mucosal prostaglandin concentrations and pyloric erosions after 48 hours.

Animals↗
PubMed1989

Computer control of anticoagulant dose for therapeutic management.

OBJECTIVE: To improve the standard of managing anticoagulant treatment and provide a basis for therapeutic quality control. DESIGN: Implementation of a comprehensive computerised system for decision support. SETTING: Three anticoagulation clinics in South Warwickshire. SUBJECTS: Patients in South Warwickshire receiving anticoagulant treatment from September 1988 to March 1989. MAIN OUTCOME MEASURE: International normalised ratio was measured and recorded at each visit. RESULTS: 688 Patients' visits were analysed statistically, and a 38% improvement was achieved in the results of international normalised ratios falling within the recommended therapeutic ranges of the British Society for Haematology. CONCLUSIONS: The implementation of a computerised anticoagulation support system resulted in better management of patients. The system provides a basis for uniform management of treatment and a common platform for national or international trials.

Drug Therapy, Computer-Assisted↗
PubMed1989

[A snow avalanche in Vassdalen. Medical experiences].

Of 31 soldiers caught by an avalanche in Northern Norway, one was not buried, 13 were partly buried and 17 were completely buried by the mass of snow. Only one of the completely buried soldiers survived. On admission to hospital after being buried by snow for three hours he had moderate hypothermia. The cause of death in the other 16 was most probably general compression of the body with acute respiratory and circulatory failure. Five of the 13 partly buried had physical traumas. None of the nine attempts at resuscitation succeeded. Self-rescue and rescue by friends were most important to the soldiers who survived. We discuss aspects of the organized rescue operation.

Accidents↗
PubMed1989

Mechanism of death in avalanche victims.

The autopsies of 12 victims from two snow avalanches in North-Norway are reported. Supportive evidence from non-autopsied and surviving victims is included. Consistent autopsy findings were prominent lung oedema, moderate cerebral oedema, extreme contraction of the left ventricle, petechiae in the superior vena cava drainage area, and acute congestion in lungs and kidneys. In four cases in whom no resuscitation was attempted, aortic oxygen pressure was in the range expected in pure asphyxial-type deaths in one and in pure cardiac-type deaths in three. No air pocket was seen in front of the mouth and nose in any of the fatal cases. Three fatal cases had fractures. It is concluded that the immediate cause of death in most cases was general body compression with acute respiratory and circulatory failure.

Adolescent↗
PubMed1989

Topical 2% mupirocin versus 2% fusidic acid ointment in the treatment of primary and secondary skin infections.

The efficacy and side effects of topical mupirocin (Bactroban) and fusidic acid (Fucidin) ointment were compared in a double-blind, randomized trial in 70 patients who came to the Dermatologic Clinic of L'Enfant Jésus Hospital with primary or secondary (or both) skin infections. Thirty-five patients were treated with mupirocin and 35 patients were treated with fusidic acid three times a day for seven days. Clinical and bacteriologic assessments were conducted before and after treatment. The efficacy of mupirocin, in terms of resolution and improvement of clinical signs and symptoms of infection, as well as of the elimination of infecting organisms, was similar to that of fusidic acid. Of 34 patients (1 could not be evaluated) treated with mupirocin, a clinical cure was achieved in 18, and significant improvement was demonstrated in 15. Similarly, of 35 patients treated with fusidic acid, a clinical cure was achieved in 18 and improvement occurred in 15. Bacteriologic cure rates were 97% (30 of 31 patients evaluated) in the mupirocin-treated group, compared with 87% (27 of 31 patients evaluated) in the fusidic acid-treated group. No side effects were observed in either treatment group. Because topical 2% mupirocin has little or no potential for irritation, systemic side effects, or cross-resistance with other antibiotics, its efficacy is likely to make this new compound a useful agent for the treatment of superficial skin infections.

Administration, Topical↗
PubMed1989

Two murine natural polyreactive autoantibodies are encoded by nonmutated germ-line genes.

Two monoclonal IgM natural autoantibodies (E7 and D23) obtained from the fusion of normal, nonimmunized, BALB/c mouse spleen cells and nonsecreting myeloma cells were selected on the basis of their polyreactivity with auto- and xenoantigens and chemical haptens. Nucleotide sequence analysis of the variable and constant regions of the heavy and light chains showed the following. (i) The antibodies arise from different genetic elements with very low or no homology--E7 from a heavy-chain variable region (VH) of family 36-60 and kappa light-chain variable region (V kappa) from a group 19--whereas D23 derives from a VH of family Q52 and V kappa derives from group 8. (ii) E7 and D23 are probably of germ-line origin, as suggested by high homology with VH genes from the unrearranged genome. Compared with the germ-line VH 1210.7 gene, E7 has a single nucleotide difference leading to a silent mutation at position 15, whereas D23 seems to be encoded by germ-line VH 101 with one nucleotide difference causing replacement of Ser-84 by Ala. (iii) The genetic V kappa and VH elements for E7 and D23 also give rise to different responses to phenyloxazolone, dinitrophenyl, 5-(dimethylamino)naphthalene-1-sulfonyl, arsonate, phosphocholine, and influenza virus hemagglutinin. Antibodies from normal and autoimmune mice with rheumatoid factor-like activity are also homologous to E7 and D23. These results indicate that polyreactive autoantibodies are encoded by germ-line genes and that, starting with the preimmune poly- and autoreactive repertoire, mutated forms of antibodies recognizing exogenous antigens can be obtained and selected.

Amino Acid Sequence↗
PubMed1989

Short-term group therapy with depressed adolescent outpatients.

A selected review of the literature about short-term therapy and social skills as they may apply to depressed adolescents is presented. Two forms of group therapy are described. These are social skills and a traditional discussion group format. Some of the difficulties in establishing and evaluating a group therapy program are outlined.

Adolescent↗
PubMed1989

Hemodynamic dose-responses to halothane and isoflurane are different in swine with and without critical coronary artery stenosis.

This study examined global hemodynamic responses to increasing concentrations of halothane and isoflurane in pigs with an acute critical coronary stenosis (CCS) on the left anterior descending coronary artery (LAD). The CCS was caused by graded inflation of an hydraulic occluder to the point where no hyperemic response was observed following a 10 sec. total LAD-occlusion. A minute, piezoelectric epicardial Doppler probe applied without dissection was used to monitor the stenosis. Previously reported minimum alveolar concentrations (MAC) were used as endtidal concentrations ([ Et]). The [Et] was increased stepwise until each animal died. Recordings obtained in this study were compared to recordings obtained during similar stepwise increments of these anesthetics in pig preparations without CCS. Isoflurane had a significantly less depressant effect on global hemodynamics compared to halothane and caused death at higher MAC than halothane in either case. A critical LAD-stenosis caused no major changes in the general dose-response pattern of isoflurane but further aggravated the depression of cardiac output and stroke volume induced by increasing concentrations of halothane.

Animals↗
PubMed1988

Preventing percutaneous absorption of industrial chemicals: the "skin" denotation.

Percutaneous absorption has received comparatively little attention in occupational health, although this route of entry has repeatedly caused occupation-related intoxications. In practice, the evaluation of skin penetration rates is far from simple. Much evidence has been obtained from studies of chemicals used for cosmetics and topical therapeutics, but the information available on compounds encountered in occupational health is limited. The data obtained from experimental studies have confirmed that the concentration, type of vehicle, skin area, skin condition, and extent of occlusion are important factors in determining the degree of percutaneous absorption, but no general model has been developed. Also, too little is known about the basic chemical properties governing the rate of penetration. Thus, prediction is difficult and bound to be rather inaccurate. Current preventive practice follows the procedure used by ACGIH and is mainly based on a "skin" denotation in official listings of chemicals to which exposure limits have been allocated. The number of substances and groups of chemicals which have received skin denotation in 17 selected countries varies between 24 and 179 and a total of 275 are listed as a skin hazard in one or more countries; ACGIH lists 143. Thus, the denotation practice varies. As an unfortunate result of these discrepancies and the dichotomy of skin denotation, the absence of skin denotation may erroneously indicate that efforts to protect the skin are unnecessary. Thus, an evaluation of skin penetration potentials should be incorporated in occupational health practice as a supplement to the official denotations.

Humans↗
PubMed1988

Effects of pregnancy and fasting on muscle glucose utilization in the rabbit.

The effects of fasting on maternal glucose metabolism were investigated in nonpregnant and 29-day pregnant conscious rabbits. Pregnancy decreased the glucose metabolic index by 60% in maternal red postural muscles. Fasting induced similar modifications in nonpregnant rabbits and exaggerated the changes observed in fed pregnant animals. These data suggest that the decreased glucose utilization by maternal red muscles observed during pregnancy and fasting is related to the increase in circulating fat-derived substrates, because the fall in plasma insulin concentration is a specific adaptation to fasting.

Adipose Tissue↗
PubMed1988

Glucose utilization by fetal muscles during maternal fasting.

In utero, glucose utilization by fetal muscles (heart and hindlimb) displays important interspecies differences. In the fed state, it is 5-fold higher in rat than in rabbit fetal muscles. Maternal fasting induces a decrease in glucose utilization in fetal muscles of the rat but not of the rabbit.

Animals↗
PubMed1988

Comparative coronary vascular reactivity and hemodynamics during halothane and isoflurane anesthesia in swine.

To assess the dose-response effects of isoflurane and halothane anesthesia on hemodynamics and coronary artery reactivity, the authors studied myocardial hyperemic responses following brief single artery flow arrests in 21 open chest, isocapnic swine in which arterial blood pressures and cardiac outputs were recorded. A specially designed Doppler probe was used to measure the peak and time course of coronary blood flow velocity in the left anterior descending coronary artery (LAD) after 15-s LAD occlusions. The ratio of peak velocity of blood flow to resting velocity (coronary reserve), relative repayment of flow debt, and duration of hyperemic responses were studied. Surgery was performed at MAC end-tidal concentrations ([Et]isoflurane = 1.45%. [Et]halothane = 1.25%) of isoflurane (n = 7) or halothane (n = 7), and recordings were made after 15-min steady state [Et]agent at 0.5, 1, 1.25, 1.5, 1.75, 2 MAC, and further 0.5 MAC increments until the demise of each animal. To compare coronary reactivity at similar coronary pressures, an aortic snare was used to elevate arterial pressures in a third group of halothane anesthesized pigs (n = 7) to those in the previously studied isoflurane group at each MAC level. There were three major differences between halothane and isoflurane. First, cardiac depression (reduction in arterial pressure, cardiac output, and stroke volume) was less with isoflurane compared with halothane anesthesia. Second, with halothane anesthesia, there was a marked decrease in coronary reactivity independent of coronary perfusion pressures with marked, dose-dependent reductions in both coronary reserve and relative flow repayment. During isoflurane anesthesia, coronary reactivity and coronary reserve was well preserved within physiologic limits up to 1.75 MAC [Et]. Third, halothane anesthesized pigs died in cardiac collapse at much lower agent concentrations than with isoflurane (no animals survived 1.75 MAC halothane, whereas all animals survived 2.5 MAC isoflurane). Therefore, pigs anesthesized with isoflurane had greater coronary reserve, better preserved cardiac function, and greater tolerance to increasing agent concentration than pigs anesthesized with halothane.

Anesthesia, Inhalation↗
PubMed1988

Glucose utilization by the placenta and fetal tissues in fed and fasted pregnant rabbits.

Glucose utilization by the placenta and individual fetal tissues was studied in vivo in conscious pregnant rabbits at 29 days of gestation. In the fed state, the rate of glucose utilization was similar in the placenta and the gravid uterus, suggesting that the rate of fetal glucose utilization was approximately 40 nmol/min/g. A 96-h maternal fast induced a significant decrease in glucose utilization by the myoendometrium and in the glucose utilization index by fetal liver and brown adipose tissue. No modification was observed in other fetal tissues. These results indicate that glucose utilization by the placenta and the whole fetus from 96-h fasted rabbits does not decrease despite profound changes in endocrine and metabolic maternal parameters.

Adipose Tissue, Brown↗
PubMed1988

In vivo metabolism of calcitriol in the pregnant rabbit doe.

The production rate, the disappearance rate and the half life of calcitriol in gravid rabbit does at 24 days of gestation were compared, under unstressed steady state conditions, to those of nonpregnant animals. The contribution of the fetoplacental unit to the circulating levels of fetal calcitriol was also assessed. The calcitriol levels (139.6 +/- 19.9 vs 55.3 +/- 8.8 pmol/l and production rates (113.9 +/- 8.8 vs 59.2 +/- 9.2 pmol/min/Kg) were higher in pregnant than in nonpregnant animals (P less than 0.01). However, clearance rates (1.07 +/- 0.18 vs 1.12 +/- 0.20 ml/min/Kg and circulating half life (442 +/- 49 vs 368 +/- 35 min; NS) were similar in both groups of animals. Fetal levels (62.3 +/- 1.6 pmol/l) and specific activity (11166 +/- 864 dpm/pmol) of calcitriol were lower than those of the respective mothers (P less than 0.005). Taken together these data suggest that, calcitriol is transported through the placenta; and that the fetoplacental unit contributes to the fetal and perhaps to the maternal calcitriol levels.

Animals↗