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Biomedical subjects

C Bertrand

Publications and source records attributed to C Bertrand.

At least 127 records · Page 7Linked to original sources
PubMed1992

Purification of electron transfer flavoprotein from pig liver mitochondria and its application to the diagnosis of deficiencies of acyl-CoA dehydrogenases in human fibroblasts.

Medium chain acyl-CoA dehydrogenase (MCAD) and long chain acyl-CoA dehydrogenase (LCAD) deficiency are defects of mitochondrial beta-oxidation. The method of choice to measure specifically acyl-CoA dehydrogenase activity in human tissues uses purified electron transfer flavoprotein (ETF). We describe a simple and optimized method of purification allowing isolation of ETF with a degree of purity never reported so far. An assay for acyl-CoA dehydrogenase activity in cultured skin fibroblasts was developed using microquantities of electron transfer flavoprotein and substrate. MCAD deficiency was demonstrated in fibroblasts from nine patients and LCAD deficiency in fibroblasts from two patients.

Acyl-CoA Dehydrogenase↗
PubMed1992

Endopeptidase 24.15 modulates bradykinin-induced contraction in guinea-pig trachea.

Guinea-pig tracheal strips were contracted with cumulative concentrations of bradykinin or substance P in the presence of thiorphan, an inhibitor of endopeptidase 24.11 and of angiotensin-converting enzyme, or in the presence of N-[1-(R,S)-carboxy-3-phenylpropyl]Ala-Ala-Phe-para-aminobenzoate (cFP-AAF-pAB), a selective inhibitor of endopeptidase 24.15. The concentration-effect curve of bradykinin was shifted to the left in the presence of each inhibitor whereas the curve of substance P was sensitive to thiorphan but not to cFP-AAF-pAB. These results show that endopeptidase 24.15 may modulate the contractile effect of bradykinin but not that of substance P in the guinea-pig trachea.

Amino Acid Sequence↗
PubMed1992

Release of sensory CGRP by hypertonic NaCl is not blocked by tetrodotoxin, omega-conotoxin, nifedipine and ruthenium red.

Hypertonic NaCl (160 mM added to the physiological salt solution) releases CGRP in a Ca(2+)-dependent manner from capsaicin-sensitive sensory nerves of the rat urinary bladder. The NaCl (160 mM)-evoked CGRP release was not affected by tetrodotoxin (0.3 microM), nifedipine (1 microM), omega-conotoxin (0.1 microM) and ruthenium red (10 microM). NaCl (160 mM)-evokes release of sensory neuropeptides without the involvement of axon reflexes, and by promoting Ca2+ influx via a dihydropyridine omega-conotoxin and ruthenium red insensitive pathway.

Animals↗
PubMed1992

Comparison of MRC-5 and continuous cell lines for detection of cytomegalovirus in centrifugation cultures.

Continuous cell lines were assessed for use for rapid human cytomegalovirus (HCMV) detection procedures combining tissue culture, centrifugation, and immediate early antigen (IEA) immunostaining. Human cells (MRC-5 embryonic fibroblasts, U-373MG astrocytoma cells, differentiated teratocarcinoma (Tera-2) cells), murine cells (BALB/c-3T3 and Y-1 cells), BHK21 hamster cells, and mink lung (ML) cells were first inoculated with HCMV laboratory strain. IEA synthesizing cells were detected by immunoperoxidase assay using a monoclonal antibody. ML cells and differentiated Tera-2 cells exhibited more positive cells than MRC-5 cells. BHK21, and MRC-5 cells were equivalent in sensitivity whereas U-373MG, BALB/c-3T3, and Y-1 cells had only reduced IEA positive cells. When 63 urine specimens were inoculated onto MRC-5, ML and differentiated Tera-2 cells, 20 (31.7%) were positive in MRC-5 cells versus 18 (28.5%) in ML or Tera-2 cells. Moreover, greater numbers of infected cells were detected in MRC-5 cells than in these two cell lines. MRC-5 cells were superior for detection of HCMV in clinical samples by centrifugation cultures.

Animals↗
PubMed1992

Another view to blood and body substance precaution: 1988-91.

Occupational transmission of human immunodeficiency virus (HIV) in hospitals can be prevented with the use of 'blood and body substance precaution'. At the Royal Victoria Hospital, an infection control objective is to get employees automatically to use blood and body substance precaution with all patients--without relying on isolation signs. The concept of blood and body substance precaution was introduced in 1988 and simultaneously used with disease-specific signs. It was observed that disease-specific signs were mostly used to identify HIV-positive patients; this was verified under documented surveillance from July 7 to August 8, 1990, when 60 patients (14 HIV-positive and 46 whose HIV etiology was unknown) were observed. All 14 known HIV-positive patients were isolated with signs, while only four of 46 unknown HIV-positive patients (8.6%) had signs. The views of individual employees were subsequently studied via a questionnaire and results from this survey showed there was preference for isolating HIV-positive patients and identifying them with a sign.

Attitude of Health Personnel↗
PubMed1992

Appendiceal mucoceles and pseudomyxoma peritonei.

Mucoceles of the appendix and associated pseudomyxoma peritonei are a heterogeneous group comprising various histopathologic lesions with differing prognoses. Between 1983 and 1990, we treated eight patients with appendiceal mucocele, three cystadenomas and five cystadenocarcinomas, three of which had accompanying pseudomyxoma peritonei. All patients were more than 50 years of age. Women outnumbered men by seven to one. Preoperative diagnosis was acute appendicitis or appendiceal abscess in all instances of mucocele unaccompanied by pseudomyxoma peritonei. Ultrasound of the abdomen, together with paracentesis, diagnosed pseudomyxoma peritonei in two of three patients. Elevated carcinoembryonic antigen levels were found in six of the eight patients and monitoring of this parameter was useful in the early detection of the two recurrences observed. The three patients with cystadenomas remain free of disease after appendectomy. Of the five patients treated for cystadenocarcinoma by right colectomy, two underwent reoperation after recurrence of disease. One patient died 41 months later of intestinal obstruction caused by pseudomyxoma peritonei. Pseudomyxoma peritonei significantly decreases survival of patients with appendiceal mucocele. In these patients, aggressive initial surgical management, repeated if need be, is indicated.

Aged↗
PubMed1991

Constant-flow insufflation prevents arterial oxygen desaturation during endotracheal suctioning.

In mechanically ventilated patients, disconnection from the ventilator and endotracheal suctioning can induce major arterial oxygen desaturation resulting from apnea, changes in inspired oxygen fraction, and decrease in lung volume. The aim of this study was to test the efficacy of a simple method of delivering oxygen and maintaining lung volume during this process. Our study was conducted in two parts. In the first part, constant-flow insufflation of oxygen (CFI) was used in seven patients ventilated for acute respiratory failure (PaO2/FlO2 = 347 +/- 33 mm Hg) as a means of maintaining arterial oxygenation during apnea and disconnection from the ventilator. CFI was administered via a modified endotracheal tube in which small capillaries allowed delivery of a high-velocity jet flow near the tracheal end of the tube during disconnection from the ventilator. In comparison to apnea alone, CFI prevented a fall in arterial oxygen tension (16 +/- 7 mm Hg during CFI versus 117 +/- 27 during apnea, after 90 s of disconnection in the two situations, p less than 0.001), whereas it did not reduce the development of hypercapnia. The efficacy of CFI resulted both from the injection of oxygen into the trachea and from the maintenance of positive alveolar pressure induced by air entrainment (mean 10.4 +/- 1.1 cm H2O), preventing a fall in lung volume usually occurring after disconnection (+338 +/- 88 ml during CFI versus -344 +/- 64 ml during apnea, p less than 0.01). In the second part of the study CFI was used to prevent arterial oxygen desaturation induced by endotracheal suctioning.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Modulation of respiratory smooth muscle reactivity by epithelial factors].

The epithelium of the pulmonary airways plays a complex role in the modulation of bronchial smooth muscle reactivity thanks to the metabolic properties and the mobilisation of contractant and relaxant factors which may issue directly from the epithelial cells or surrounding cells. The expression of these epithelial factors varies along the length of the tracheo-bronchial tree and with the species of animal being considered. Neuronal cells and inflammatory cells may equally intervene and interfere with relaxant and contractant factors depending on the epithelium. But the greatest difficulty in characterising these epithelial factors residues in the functional antagonism between relaxant and contractant factors when they are jointly expressed. Amongst factors depending on the respiratory epithelium prostaglandin E2 would be one of the relaxing factors and Calcitonin Gene-Related Peptide (CGRP), one of the contracting factors.

Animals↗
PubMed1990

Selective implication of thromboxane A2 and PAF-acether in two guinea pig anaphylactic models.

In an IgE and an IgG model of anaphylaxis in the guinea pig, we investigated the role of prostanoids and PAF-acether in the tracheal response in vitro to immunochallenge. Indomethacin (10(-6) M) potentiated the antigen-induced contraction in both models suggesting the synthesis of relaxant prostaglandins during the anaphylactic phenomenon. UK-38,485 (10(-5) M), a thromboxane (TxA2) synthetase inhibitor, did not modify the tracheal response in the IgE model. In the IgG model, this drug reduced the response of the tracheal strips to antigen. Ro 19-3704 (10(-6) M) and BN 52021 (10(-5) M), two potent PAF antagonists, reduced antigen-induced contraction of the tracheal strips in the IgE model. These two drugs did not modify the contractile response in the IgG model. These results indicate that PAF-acether and TxA2 play a role in the IgE and IgG model of anaphylaxis, respectively.

Anaphylaxis↗
PubMed1990

Evidence for the involvement of calcitonin gene-related peptide in the epithelium-dependent contraction of guinea-pig trachea in response to capsaicin.

Capsaicin (10(-9) to 10(-5) M) contracted guinea-pig tracheal strips. Epithelium-containing tracheal strips developed a maximum active tension which was significantly higher than that observed in epithelium-free strips. Anti-CGRP (calcitonin gene-related peptide) serum blocked the epithelium-dependent potentiation of the capsaicin-induced contraction in the intact tracheal strips, without affecting the response of the epithelium-free strips. This result suggests the occurrence of an epithelium-dependent release of CGRP. This same serum markedly reduced the contraction induced by exogenous rat CGRP in both intact and epithelium-free tracheal strips. In epithelium-free tracheal strips, capsaicin-induced contraction was abolished by spantide (10(-6) and 10(-5) M), a substance P antagonist, but, in intact tracheal strips, spantide did not abolish the capsaicin-induced contraction, showing that both CGRP and substance P release are directly induced by capsaicin. Moreover, the contractile responses to rat CGRP of intact tracheal strips from guinea pig suggest that CGRP itself might be able to release a contracting factor from the airway epithelium. Therefore, CGRP originating from the airway epithelium may play a major role in the control of airway smooth muscle tone.

Animals↗
PubMed1990

The sensitivity to Zn2+ discriminates between typical and atypical mast cells.

The effects of zinc gluconate have been studied on rat peritoneal mast cells and rat basophilic leukemia cells (RBL 2H3) stimulated by various secretagogues. The IC50's of zinc gluconate on peritoneal cells were (microM): 1.6, 1.9, 5.4 and 18 for ionophore A23187, phorbol 12-myristate 13-acetate, substance P and immunoglobulin E-antigen, respectively. Higher concentrations of zinc gluconate were required to inhibit histamine secretion from RBL 2H3 cells, i.e. 12 microM (ionophore A23187) and 140 microM (immunoglobulin E-antigen). Zinc gluconate (10(-4) to 10(-3) M) also inhibited the IgE-dependent contraction of guinea pig trachea but was unable to affect that induced by exogenous histamine. These results suggest that zinc gluconate acts intracellularly and is selective of "typical" or "connective tissue" mast cells.

Animals↗
PubMed1990

Calcium-induced gelation of low methoxy pectin solutions--thermodynamic and rheological considerations.

Rheological changes occurring during the gelation of low methoxy pectins in the presence of calcium ions were investigated. The onset of gelation was found to correspond to the same macroscopic rheology (i.e. value of G') whatever the gelling conditions. Sol-gel diagrams for calcium pectin systems were mapped out in terms of calcium level, temperature and pectin concentration. The thermodynamic parameters for the cross-linking process were derived.

Calcium↗
PubMed1990

Protective effect of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced acute pancreatitis in rats.

This study was performed to assess the effects of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced pancreatitis. Per group of 10 each, male Wistar rats received either cerulein (2.5 micrograms/kg/h subcutaneously), cerulein and misoprostol (500 micrograms/kg intraperitoneally at 0 and 4 h), or saline. Rats were killed 6 h after the first injection. Misoprostol treatment significantly reduced interstitial edema and acinar cell lesions induced by hyperstimulation. Pancreatic amylase and chymotrypsin contents were increased by cerulein and returned towards control levels in the misoprostol-treated group. The lysosomal volume density and the pancreatic beta-D-glucuronidase activity were significantly increased after hyperstimulation. The two parameters were significantly reduced by misoprostol. A protective effect of misoprostol against lesions induced by cerulein hyperstimulation would be a consequence of a lysosomal stabilizating effect.

Acid Phosphatase↗
PubMed1990

Mediastinal chondrosarcoma. Case report.

A 34-year-old man and a 71-year-old woman underwent radical removal of mediastinally sited chondrosarcoma, presumably originating in the periosteum of the vertebral body. The man (with mesenchymal chondrosarcoma) died of remote metastasis 6 years postoperatively. The woman (poorly differentiated chondrosarcoma, grade 2-3) is still alive 2 years after the operation.

Adult↗