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Biomedical subjects

A Moreau

Publications and source records attributed to A Moreau.

At least 163 records · Page 9Linked to original sources
PubMed1989

Cigarette smoking-induced changes in the number and differentiated state of pulmonary dendritic cells/Langerhans cells.

To evaluate the effect of cigarette smoking on the number, distribution, and differentiated state of dendritic cells (DC) and Langerhans cells (LC) in the human lung, we have quantitated the number of these cells present in the bronchioles and alveolar parenchyma of lung tissue from nonsmokers and cigarette smokers using anti-CD1 monoclonal antibodies which react preferentially with DC (M241) and LC (T6). M241+ DC were found in the bronchiolar submucosa and alveolar parenchyma of nonsmokers; T6+ LC were present within the bronchiolar epithelium. Cigarette smoking was associated with a twofold increase in the total number of cells of DC/LC lineage and a 30-fold increase in the number of T6+ cells, many of which contained Birbeck granules (LC), present in the alveolar parenchyma. Most LC found in the parenchyma of smokers were observed in close association with areas of alveolar type II pneumocyte hyperplasia. Cigarette smoking did not change the number of differentiated state of cells of DC/LC lineage within the bronchioles. Both DC and LC are present in the human lung. Cigarette smoking has an important effect on the number, distribution, and differentiated state of these cells, which may explain why most adult patients who develop Langerhans cell granulomatosis are smokers.

Adult↗
PubMed1989

Rapid detection of Streptococcus suis serotype 2 in weaned pigs.

A survey to detect Streptococcus suis serotype 2 in 1,716 weaned pigs was done in Quebec. Forty-nine sow herds were included in this survey: in 26 herds, S suis serotype 2 had been isolated during the preceding 12 months and in 23 herds (control), the organism had not been detected during a previous study. Swab specimens of the nasal cavity and tonsils of pigs were obtained for bacteriologic culture, and S suis serotype 2 was easily detected by the use of brain-heart infusion agar containing a Streptococcus-selective supplement and 5% goat antiserum raised against S suis serotype 2. After measurement of the diameter of the precipitation zone of 539 isolates, a slide agglutination test was performed to identify the S suis serotype 2 isolates. The mean precipitation zone diameter obtained for group S suis serotype 2 was larger (P less than 0.001) than that for the group designated as "others". With slide agglutination test results as reference and on the basis of discriminant analysis to stimulate detection of S suis serotype 2, 93.1% of all isolates were correctly classified, using the precipitation zone diameter as unique classification criterion. Relative specificity was 94.5% and relative sensitivity was 88.7%. Use of the precipitation zone diameter on a quantitative basis led to the proposal of a simple and reliable technique to screen swine herds for S suis serotype 2 in weaned pigs. Nasal and tonsillar swab specimens were obtained and analyzed concurrently for S suis serotype 2. The organism was found in both sites in only 20.4% of 103 carrier pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Agglutination Tests↗
PubMed1988

Analysis of hepatocyte plasma membrane polarity during rat azo dye hepatocarcinogenesis using monoclonal antibodies directed against domain-associated antigens.

While carcinogenesis is known to induce various alterations in epithelial cell polarity, little information is available about the fate of plasma membrane polarity during the neoplastic process. Using three monoclonal antibody-defined antigens as markers of the three plasma membrane domains of rat hepatocytes, the sinusoidal, the lateral, and the canalicular, we demonstrated by immunohistochemical techniques that changes in hepatocyte plasma membrane polarity occur at every stage of 3'-methyldimethylaminoazobenzene-induced hepatocarcinogenesis. At the preneoplastic stage, the division of hepatocyte plasma membrane into three distinct domains was retained despite rearrangements in hepatocytic architecture, characterized by the disorganization of hepatocytic plates and the formation of pseudoacinar structures. The most striking change was the distribution of the canalicular-associated antigen over the entire plasma membrane in disorganized plates. At the neoplastic stage, changes in plasma membrane polarity depended on the degree of morphological differentiation of neoplastic cells. Poorly differentiated cells inconstantly expressed the monoclonal antibody-defined antigens and showed no evidence of plasma membrane polarization. Differentiated cells constantly expressed the three antigens, and their plasma membrane was divided into antigenically distinct domains. The changes in hepatocyte plasma membrane polarity demonstrated in situ during 3'-methyldimethylaminoazobenzene hepatocarcinogenesis may therefore be compared with situations known to occur in vitro, in cultured epithelial cells presenting varying degrees of polarization. Our observations suggest that these alterations are of relevance to the in vivo biology of cancer.

Animals↗
PubMed1988

Analysis of hepatocyte plasma membrane domains during rat development using monoclonal antibodies.

The plasma membrane of adult rat hepatocyte consists of three domains, which have been identified by the monoclonal antibodies A39 and A59 as markers of the sinusoidal domain, B1 of the lateral, and B10 of the canalicular domains (Eur J Cell Biol 39:122, 1985). These monoclonal antibodies were used to study, by indirect immunocytochemistry, formation of the hepatocyte plasma membrane domains during development, from day 15 of gestation to day 35 post partum. The antigens defined by A39, B1, and B10 were detected, from day 15, over the major part of the hepatocyte plasma membrane except for the membranes of newly formed bile canaliculi, which were not labeled by B1 and only poorly labeled, if at all, by A39 and B10. As soon as fetuses were 16 days old, B1 labeled predominantly the lateral domain, as in the adult. Labeling with B10 progressively intensified on the membranes of bile canaliculi, but localization was not exclusively canalicular until day 21 post partum. A39 intensely labeled the canalicular membranes at 19-21 days of gestation, while at 35 days post partum it exhibited the predominantly sinusoidal labeling observed in adult hepatocytes. The antigen defined by A59 was not detected before birth and was found exclusively on the sinusoidal domain, as in the adult. These results show that the patterns of antigen distribution on different plasma membrane domains establish themselves at different rates. The marked differences observed between fetal or neonatal and adult hepatocytes might be responsible for immaturity of liver functions in the neonate.

Animals↗
PubMed1987

[Current aspects of bronchial tuberculosis].

The authors report a retrospective study of 34 cases of bronchial tuberculosis observed between 1981 and 1985 with precise endoscopic and histological data. Analysis of the population showed a male predominance (71 p. 100) and a high incidence of black Africans (54 p. 100), much higher than that observed in the general population of tuberculosis in our department (20 p. 100 of black Africans). Three groups of patients were identified with respect to age: group I, 23 patients aged 18 to 32 years; 22 of these patients were black Africans (98 p. 100) with primary tuberculosis; group II, 4 patients aged between 44 and 56: all were immunocompromised; group III, 7 patients over 65 years of age with reinfections: 6 of these 7 patients were French nationals. Apart from the specific problem of immunodepression observed in group II, two distinct features were identified: the primary lympho-bronchial infection of the young African and tuberculous bronchial reinfection of European women over of the age of 65.

Adult↗
PubMed1986

Inhibitory effect of the acute inflammatory reaction on liver regeneration after partial hepatectomy in the rat.

We evaluated the influence of an acute inflammatory reaction that triggers the synthesis of exportable proteins by hepatocytes on liver regeneration after partial hepatectomy, which induces the synthesis of proteins necessary for liver cell proliferation. In hepatectomized rats with a turpentine-induced acute inflammatory reaction, the first peaks of hepatic DNA synthesis and mitosis were significantly inhibited compared with pair-fed controls subjected to partial hepatectomy only, and the liver DNA concentration at various times after partial hepatectomy was significantly lower in the former than in the latter. Inhibition was not obtained when the acute inflammatory reaction was induced 12 h or more before partial hepatectomy, suggesting that the inhibitory effect of turpentine administration depended on early events in the acute inflammatory reaction. These data suggest that one possible mechanism responsible for inhibition of regeneration might be competition at the transcriptional or the translational level between liver syntheses of various proteins, and that, under certain conditions, liver-specific functions might take precedence over regenerative functions.

Acute Disease↗
PubMed1986

Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia.

Acute anticholinergic delirium has been reported to occur following ingestion of antidepressants, neuroleptics and antiparkinsonian drugs in toxic and therapeutic doses. A case is described of a chronic central anticholinergic syndrome in a patient receiving a combination of such drugs. This chronic anticholinergic toxicity was superimposed on manic depressive illness which resulted in incorrect diagnoses including schizophrenia and dementia and, accordingly, improper management. Diagnosis of central anticholinergic toxicity may be overlooked in psychiatric patients because the symptoms of toxicity can be incorrectly ascribed to psychiatric illness. It may also be overlooked in elderly patients who are prone to demonstrate confusion and problems with memory. The recognition of this syndrome in the patient reported, at least nine years after it developed, led to appropriate management which ultimately resulted in a dramatic change in her ability to function.

Aged↗
PubMed1986

[Evolution of the resistance of Streptococcus pneumoniae to erythromycin at the Pitié-Salpêtrière Hospital (1980-1984)].

From January 1980 to December 1984, 563 swabs for Streptococcus pneumoniae were isolated at the Pitié-Salpêtrière hospital in Paris, and of these 63 were resistant to erythromycin. The percentage of swabs resistant to erythromycin rose from 2.7% in 1980 to 19.6% in 1984 and was similar for cultures of blood, serous fluid, bronchial secretions, otolaryngological specimens and smears from the conjunction. For swabs resistant to erythromycin these belonged almost exclusively (57 out of 60 or 90%) to the serotypes 6, 14, 19 and 23; one may ask whether the rise in resistance of S. pneumoniae to erythromycin was due to a rise in the frequency of isolation of these serotypes? Between 1980 and 1984 such rise took place since the frequency of isolation of S. pneumoniae belonging to the serotypes 6, 14, 19 or 23 rose from 38% in 1980 to 50% in 1984, but the rise was not significant (p = 0.1). In fact S. pneumoniae serotypes 6, 14, 19 or 23 have become resistant is significant (p less than 0.05). Two factors should be taken into consideration when interpreting these facts. The first is the increased consumption of macrolide antibiotics which doubled overall between 1979 and 1983, both at the Pitié-Salpêtrière hospital and in the Public Assistance hospitals of Paris as well as provincial hospitals throughout France. The second factor is the strictly hospital nature of this study which may have led to an overestimation of the frequency of resistance of S. pneumoniae to erythromycin.

Cross Infection↗
PubMed1985

Liver perisinusoidal fibrosis in BB rats with or without overt diabetes.

Perisinusoidal fibrosis is a vascular lesion observed in the liver of type I diabetic patients. To investigate whether this liver lesion is secondary to hyperglycemia or whether it represents a separate collagen vascular disorder, the authors studied the structure of liver sinusoids in genetically susceptible BB rats in which a spontaneous diabetes develops similar to human type I diabetes. Seven diabetic insulin-treated BB rats, 7 nondiabetic BB rats, and 6 control non-BB rats were studied. Histologic abnormalities of the collagen network were detected on trichrome-stained sections. Perisinusoidal collagen fibers were quantified ultrastructurally by the point-counting method. All control non-BB rats had normal livers; 86% of the diabetic as well as 71% of the nondiabetic BB rats displayed localized sinusoidal thickening corresponding ultrastructurally to perisinusoidal fibrosis; in these abnormal rats the percentage of collagen fibers per sinusoid unit was significantly higher than that in controls. Fibrous septa (2 diabetic and 5 nondiabetic BB rats) and liver nodulation (3 diabetic and 1 nondiabetic BB rats) were also observed. Perisinusoidal fibrosis is a frequent liver vascular abnormality in a strain of rats genetically predisposed to the development of type I diabetes. The lesion is independent of the presence of diabetes. These observations suggest that liver perisinusoidal fibrosis in patients with type I diabetes might be linked to a genetic abnormality rather than to hyperglycemia per se.

Animals↗