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Biomedical subjects

C Bertrand

Publications and source records attributed to C Bertrand.

At least 145 records · Page 8Linked to original sources
PubMed1989

Contractile activity of the N-acylated C-terminal part of substance P7-11 in guinea pig trachea. Effect of epithelium removal.

Substance P, neurokinin A, neurokinin B, and N-acylated pentapeptide X-Phe-Phe-Gly-Leu-Met-NH2 analogs of substance P7-11 were tested for their spasmogenic activities in intact or in epithelium-denuded tracheal strips from guinea pig. Epithelium removal enhanced the efficacies and potencies relative to substance P of all the peptides tested in guinea pig trachea. In epithelium-containing preparations, the presence of a cyclic substituent (o-hydroxyphenyl-acetyl, p-hydroxyphenyl-acetyl, pyroglutamyl) in Phe7 greatly enhanced the potency and efficacy compared to substance P. These substitutions were twice as active as neurokinin A itself. The presence of an aliphatic chain (non-protected and t-butyloxycarbonyl-protected aminopropyl and aminocaproyl) in Phe7 also improved the potency and the efficacy of the synthetic peptides. The aliphatic substituents could favour an increase in local concentration of the peptides in the vicinity of the receptor(s) allowing a more effective ligand-receptor interaction. Thus, lipophilicity could be determinant in the potency of the peptides in intact guinea pig trachea. In epithelium-denuded tracheal strips from guinea pig, all the synthetic peptides were more effective than substance P but less active than neurokinin A which probably reflects the presence of the NK2 receptor subtype, which may be predominant in this type of epithelium-denuded preparation. Our results suggest that hydrophobicity plays a strong role in the interaction of the peptides, namely substance P and its analogues with the membrane and possibly the receptors themselves.

Animals↗
PubMed1989

Protective effect of misoprostol, a synthetic prostaglandin E1 analog, on experimental pancreatitis induced by pancreatic duct ligation in rat.

This study was performed to assess the effects of misoprostol (M), a synthetic prostaglandin E1 analog, on experimental pancreatitis in rat. Pancreatitis was induced by ligation of the main pancreatic duct of 3-month-old male Wistar rats. Pancreatic lesions were observed at 6, 12, 24, 48, and 96 h after pancreatic duct ligation (PDL). A time of 48 h was chosen to evaluate M treatment. M was injected intraperitoneally (500 micrograms/kg every 4 h) between time 0 and 48 h after PDL. Stereological analysis was performed on light and electron microscopy. Total pancreatic amylase and chymotrypsin concentrations were determined. Four groups of five rats were studied: sham operated (SO), M without PDL (PG), duct ligation without M (DL), and duct ligation with M (DLPG). Edema, dedifferentiation of pancreatic acinar cells, and heterogeneous distribution of zymogen granule diameters observed after PDL were significantly decreased by M in the DLPG group. Enzyme concentrations were also decreased by M in the DLPG group. Enzyme concentrations were also decreased by M both in normal (PG) and duct ligated rats (DL). M has protective effects against pancreatic lesions induced by PDL. In this model, the protective effect of M may be due to a blockade of the autodigestive secretions of the pancreatic acinar cells.

Alprostadil↗
PubMed1989

Nedocromil sodium inhibits IgE- and IgG-related antigen-induced contraction in guinea-pig trachea.

The effects of nedrocromil sodium and disodium cromoglycate were studied on the anaphylactic contraction of guinea-pig trachea in two models of active sensitization (IgE and IgG models). The influence of epithelial removal on the effects of nedocromil sodium and disodium cromoglycate was examined because several studies have shown that the epithelial layer can modulate agonist- or antigen-induced contractile responses. Disodium cromoglycate (10(-4) M) and nedocromil sodium (10(-4) M) provided significant protection against antigen-induced contractions of guinea-pig tracheal smooth muscle in the IgG model. But only nedocromil sodium had an effect at this concentration in the IgG model and was also effective at 10(-5) M in the epithelium-denuded tracheal strips. At this concentration, disodium cromoglycate lost its protective effect. Comparison with the results obtained with FPL-55712, AA-861 and mepyramine suggested that these drugs affect histamine and particularly leukotriene synthesis and/or release by mast cells or other immunocompetent cells. These findings indicate that nedocromil sodium inhibits the IgE- and IgG-related antigen-induced contraction in guinea-pig airways, whereas disodium cromoglycate inhibits only the IgG-related processes. This study supports the hypothesis that these drugs modulate antigen-induced mediator synthesis and/or release from immunocompetent cells.

Airway Resistance↗
PubMed1989

Effect of long-term intraluminal perfusion of pentagastrin on rat small-intestinal mucosa.

Mucosal changes occurring during long-term intraluminal perfusion of pentagastrin in the duodenum of conscious adult rats (100 micrograms/24 h/kg, 6 days) were studied. Significant increases of labelling and of mitotic indices were noted in the whole small intestine, with an enlargement of the crypt epithelial proliferative compartment. Differential kinetic variations were observed between upper and lower parts of the small intestine when labelling indices were measured in accordance with the cell position in the crypts. Kinetic variations were correlated to the increases of villous and microvillous area. Alkaline phosphatase and leucine-aminopeptidase-specific activities were significantly increased, suggesting modifications of synthesis and/or maturation of these enzymes. The ileal Paneth cell number was also significantly increased in the ileum. Pharmacologic doses of pentagastrin intraluminally perfused have a trophic effect at all levels of the small-intestinal mucosa.

Alkaline Phosphatase↗
PubMed1989

Characterization of muscarinic receptors in human, guinea pig and rat lung.

Muscarinic receptor subtypes in human, guinea pig and rat lung tissue were characterized by radioligand binding, and functional studies were carried out on guinea pig and rat tissues. Control binding experiments were performed with membranes from human tissues rich in M1 (hippocampus), M2 (pons-medulla) and M3 (salivary gland) receptor subtypes. Competitive binding experiments with atropine and 4-diphenylacetoxy-N-methylpiperidine methobromide did not reveal any tissue selectivity of these ligands. Pirenzepine, a selective M1 antagonist with 11-2[[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]-5, 11-dihydro-6H-pyrido[2,3-b] [1,4]-benzodiazepine-6-one (AF-DX116), a selective M2 antagonist, made it possible to characterize muscarinic subtypes. In hearts from the three species, the low affinity for pirenzepine and the high affinity for AF-DX116 were related to M2 receptors. In rat lung, the high affinity for AF-DX116 and the intermediate affinity for pirenzepine indicate M2 and M3 subtypes. Guinea pig and human lung tissues contain 48 and 67%, respectively, of muscarinic binding sites with high affinity for pirenzepine (M1). The second muscarinic receptor population in human lung might be classified as M3 in view of the cardioselectivity of AF-DX116, but the occurrence of M2 cardiac-type receptors could not be excluded. In guinea pig lung, both M2 and M3 subtypes might occur in addition to M1 receptors. Muscarinic stimulation led to the contraction of guinea pig and rat lung strips but did not significantly affect human lung strips. We suggest that presynaptic M2-muscarinic receptors modulated the M3-induced contraction in the guinea pig lung smooth muscle.

Animals↗
PubMed1988

Membrane phospholipid polar heads influence the coupling of M2 muscarinic receptors to G proteins.

Treating membranes from rat heart with phospholipase C (phosphatidylcholine choline phosphohydrolase) from Clostridium perfringens increased the affinity of muscarinic acetylcholine receptors (M2) for the agonists carbachol and oxotremorine. The affinity for antagonists was not affected. Phospholipase C activity, i.e., the cleavage of polar heads of membrane phospholipids, led to the disappearance of the guanine nucleotide-dependent rightward shift of the isotherm for agonist binding. The treatment of tracheal smooth muscle with phospholipase C led to a decrease in the maximum contractile effect of muscarinic (M2) stimulation with no modification of the agonist EC50, i.e., to the uncoupling of the stimulation-contraction process. These results demonstrate that when phospholipid polar heads are hydrolysed by phospholipase C, M2 receptors are uncoupled from G proteins, which enhances their affinity for agonists but prevents information transfer.

Animals↗
PubMed1988

Silent human pancreatic glucagonoma and "A" nesidioblastosis.

Surgical fragments of healthy and tumor-bearing pancreas from a patient with pancreatic tumor were studied by electron or light microscopy, histochemistry, and immunocytochemistry (human insulin, glucagon, somatostatin, gastrin, and bovine pancreatic polypeptide). Histological results were compared to those obtained by radioimmunoassay, both in tumor and serum. The tumor was identified as a glucagonoma because reactions for Grimelius' silver impregnation and immunoreaction with an antiserum against glucagon were positive and because a very high level of glucagon in the tumor was observed. Insulin, somatostatin, and gastrin levels remained normal, both in tumor and serum, but the glucagon level was normal in serum. Associated with this silent glucagonoma, an uncommon nesidioblastosis was also diagnosed with many A cells irregularly mixed with acinar cells, isolated or clustered in small groups. Acinar "intermediate" cells of "A" type were also observed. Such associative histopathological processes evoked possible development of an endocrine tumor from nesidioblastic-like tissue. Its embryogenic origin remained uncertain.

Adenoma, Islet Cell↗
PubMed1988

Pharmacokinetics and human tissue penetration of flurithromycin.

The relationship between concentrations in serum and levels in tissue of flurithromycin, a new fluorinated macrolide, was determined in patients undergoing maxillofacial surgery and thoracotomy. All patients received 500 mg of flurithromycin orally every 8 h. Drug levels in serum, bone, soft tissue, lung, and pericardial fluid were determined microbiologically. The total amount of antibiotic per gram of tissue was calculated on the basis of the concentration in the supernatant of the homogenate. From the parallel course between free concentrations in serum and calculated contents in interstitial fluid tissue, it was concluded that the tissues examined were easily accessible by flurithromycin; penetration values measured by the ratio of areas under the curve were 8.3 for lung, 3.6 for bone, and 0.8 for soft tissue. The results of the pharmacokinetic study suggest that accumulation of the drug during repetitive multiple doses is predictable. Mean residence times were 10.2 and 8.3 h in groups 1 and 2, respectively. For bacteriostatic drugs such as macrolides, not only very high but also prolonged concentrations in tissue lead to favorable therapeutic result.

Adult↗
PubMed1988

[Spontaneous rupture of the esophagus (presentation of a case)].

The authors describe the case of a 67-year-old patient with spontaneous rupture of the middle third of the oesophagus, occurring apparently without any involvement of intraluminal hypertension. The surgical treatment consisted in the execution of an aspiration drainage of the left pleural cavity, followed by a right thoracotomy with exploration of the mediastinum. A gastrostomy according to Witzel was also performed. Total parenteral nutrition was instituted in the post-operative period. Healing of the oesophageal lesion was confirmed radiologically 2 months after admission to our department.

Aged↗
PubMed1988

Bronchopulmonary carcinoids: report of nine surgically treated cases.

Nine cases of bronchial carcinoids treated by surgery are reported. Six of them were females and three males. Their ages ranged from 37 to 68 years (median 52.8 years). Lobectomy was carried out in four instances (bilobectomy in one) and pneumonectomy in three. Based on preoperative histology two conservative operations were performed: one patient underwent segmental resection of the right upper lobe for a peripheral carcinoid and the other sleeve resection of the bronchus. The operations were complicated only in one case in which a broncho-pleural fistula appeared postoperatively and was successfully treated by thorachoplasty. There was no postoperative death. The only patient with an atypical carcinoid died one year after pneumonectomy. The other eight patients, with typical carcinoids are alive and without recurrent disease at 6 months to 8 years from surgery. Lymph node and parenchymal infiltration, observed in 3 patients, were not fatal. It is concluded that carcinoids should now be considered malignancies; typical carcinoids carry a more favorable prognosis than atypical ones and can be managed by conservative operations without affecting the survival rate. The spreading of the tumor to lymph nodes and surrounding tissues was not associated with an increased mortality in the reported cases.

Adult↗
PubMed1987

Imipenem kinetics in serum, lung tissue and pericardial fluid in patients undergoing thoracotomy.

Imipenem serum pharmacokinetics, lung tissue and pericardial fluid concentrations were measured in 10 patients undergoing thoracotomy, following a 1 g intravenous infusion of imipenem-cilastatin. The serum concentrations of imipenem 0.5 h and 4 h after the end of the 40 min infusion were 53.3 (+/- 16.7) and 2.0 (+/- 0.3) mg/l, respectively. The concentration of imipenem in lung tissue at 1 h was lower than in pericardial fluid and at 2.25 h the mean concentration of imipenem in pericardial fluid was 10.5 mg/l, vs. 0.28 mg/kg of lung tissue. Imipenem concentrations in pericardial fluid remained above 5 mg/l, well above the MIC for most pathogens, for 1 h whereas in pericardial fluid the concentration was 10.5 mg/l at 2.25 h.

Body Fluids↗
PubMed1987

Observations and analysis of results in 131 cases of spasmodic torticollis after selective denervation.

In 131 patients treated exclusively by selective denervation during the past 10 years, all or almost all the abnormal movements of spasmodic torticollis were suppressed in 115 (88%) while preserving posture and mobility. This approach was also used in certain forms of adult-onset dystonia. An appreciable amount of abnormal movements remained in the other patients, either due to residual innervation or because of limitation of denervation necessary to preserve normal movements (laterocollis) or neck stability (retrocollis). A medio-lateral approach to the posterior cervical region in the sitting position using stimulation under light anaesthesia is recommended.

Humans↗
PubMed1987

[Early detection of cytomegaloviruses from pathological matter and feces].

CMV can be isolated within 24 or 48 h post-infection of human diploid fibroblasts cells cultures by detection of immediate early antigen with immunological techniques using E13 monoclonal antibody. Optimal enhancement of CMV detection is obtained by centrifugation at 4,000 g for 45 minutes of specimen inoculum onto cell culture monolayers. Rapid immunodiagnosis can be applied to cells from clinical specimens faster than with culture but it is less sensitive. This rapid diagnosis of CMV infection enables early prescription of appropriate antiviral chemotherapy.

Antigens, Viral↗
PubMed1987

[Value of the detection of serum anti-cytomegalovirus antibodies applied to the diagnosis of recent infection].

Cytomegalovirus (CMV) infection is a major cause of morbidity in immunodepressed patients: the diagnosis is based on the demonstration of CMV viraemia and/or specific IgM and/or a significant rise in antibody titres. This study was undertaken to compare the diagnostic value of these parameters. Eighteen patients with the AIDS and CMV infection were investigated; CMV viraemia was demonstrated in 87 p. 100 and specific IgM in 23 p. 100 of cases; in 24 patients followed up for 4 months after bone marrow transplantation viraemia was demonstrated in 70 p. 100 and IgM in 54 p. 100 of cases; however, the detection of IgM was often late. In contrast, specific IgM is frequently detected in CMV infection of non-immunodepressed patients.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Serological methods proposed for the determination of immune status with regard to cytomegaloviruses].

The detection of CMV antibodies is the only routine method available for differentiating seronegative donors who cannot transmit CMV infection from seropositive donors who are latent carriers and who may transmit the infection by blood transfusion or transplant operations. The validity of this selection depends on the sensitivity and specificity of the method used. We compared the results of 46 serums by the following five tests known for their sensitivity: the indirect haemagglutination test, the latex agglutination test (CMV Scan, Becton-Dickinson); two ELISA tests (Enzygnost anti-Cytomegalovirus-Behring; the Abbott CMV total AB EIA), and the IgG CMV Immunocapture Wellcome. The causes of the discrepancies observed in 7 sera are discussed.

Agglutination Tests↗
PubMed1987

Conservation and map location of human cytomegalovirus strain Ad-169 transforming sequences in the DNA of clinical isolates.

All DNAs from human cytomegalovirus studied (57 fresh isolates, 3 reference strains) showed hybridization under stringent conditions to a plasmid containing strain Ad-169 transforming sequences. Analysis of hybridization patterns obtained with DNAs digested by three different enzymes allowed construction of a global map for this highly conserved area of the genome.

Cell Transformation, Neoplastic↗