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Biomedical subjects

M Vincent

Publications and source records attributed to M Vincent.

At least 307 records · Page 17Linked to original sources
PubMed1984

Central and peripheral catecholamine synthesizing enzymes during the development of two-kidney, one clip hypertension in rats.

The activities of the catecholamine synthesizing enzymes have been determined in discrete brain areas and in peripheral tissues of rats, at different times after clipping the left renal artery (two-kidney Goldblatt hypertension, 2KGH) and in sham operated animals. Three days after clipping the only enzymatic change was a slight decrease in plasma dopamine-beta-hydroxylase (DBH) activity. Ten days after clipping no change in enzymatic activity was found at the central level. However, the DBH and the phenylethanolamine-N-methyltransferase (PNMT) activities were increased in the adrenal medulla (+49.0%, P less than 0.001 and +36.6%, P less than 0.001, respectively) and DBH activity was also increased in the superior cervical ganglia (+22.8%, P less than 0.01). These data suggest that sympathetic hyperactivity is present in 2KGH rats when hypertension is established. In addition, as this type of hypertension does not alter the PNMT activity in brainstem areas, it seems that the alterations in PNMT activity reported for genetically hypertensive rats are unlikely to be secondary to the elevated blood pressure.

Adrenal Medulla↗
PubMed1984

Initial evaluation of the non-sulfhydryl-containing converting enzyme inhibitor MK-521 in hypertensive humans.

MK-521 is a new orally active, nonsulfhydryl angiotensin-converting enzyme (ACE) inhibitor. Single doses of 2.5, 5.0, 10.0, and 20.0 mg were administered to nine hypertensive patients alternating with placebo. All doses of MK-521 caused profound suppression of ACE activity for more than 24 h and decreased standing diastolic blood pressure for more than 12 h without changes in pulse rate. Although there was no further reduction in blood pressure with doses above 5.0 mg, the duration of action was prolonged for more than 24 h with the higher doses. Serum MK-521 concentrations increased with dosage, and ACE was inhibited maximally at concentrations above 10 ng/ml. In this initial study, MK-521 was well tolerated and proved to be a potent and long-acting antihypertensive agent.

Adult↗
PubMed1984

[Pulmonary mucormycosis. Apropos of a case with serologic confirmation].

We report a new case of primary pulmonary mucormycosis. The radiographic evidence and anatomopathological facts demonstrate an intra-cavitary mycetoma of Fowler associated with a chronic pneumonia in the left basal segment. The patient was not immunosuppressed but had undergone a left upper lobectomy 25 years before. This appears to be the first case in which a serological study has confirmed the diagnosis.

Humans↗
PubMed1984

[Alveolar cancer and localized parieto-alveolar fibrosis].

We report a case, cytologically diagnosed, of broncho-alveolar cancer associated with localised interstitial pulmonary fibrosis. This association of fibrosis with bronchiolo-alveolar cancer is classical and a pathogenic affiliation has been deduced by the majority of authors. We review the pathogenesis in relation to recent datas concerning the activation of successive oncogenes: the first stage of carcinogenesis may correspond to the activation of an oncogene coding for a fibroblastic growth factor leading to fibrosis.

Adenocarcinoma↗
PubMed1984

[Diffuse pulmonary carcinomatous lymphangitis. Study of respiratory function in 18 cases].

Respiratory function studies were carried out in 18 patients with diffuse and isolated pulmonary lymphangitis (LCP) diagnosed on radiological and cyto-histological grounds. Restrictive ventilatory defects were found in 17 out 18 cases CPT: 75,3% (DS = 5), CV: 56.7% (DS = 14,5). The Tiffeneau coefficient was less than 65% in 50% of cases but the DEM/CV was reduced in 77% of cases, evidence of the great frequency of airflow obstruction. The measure of the (formula; see text) was normal in 5 out of 17 cases, implying the absence of an alveolar neoplastic lesion or obliteration by arteritis or capillaritis in LCP. The alveolar-arterial oxygen gradient on hyperoxia was normal (less than 27 kPa) 14 times out of 18 and slightly increased in 4. Important hypoxaemia at rest was present 17 times out of 18; PaO2: 8 kPa (DS = 1). There was no patient with alveolar hyperventilation: PaCO2: 4.3 kPa (DS = 0.5). On exercise, hypoxaemia remained stable 4 times, improved 5 times and worsened 9 times. A pathophysiological interpretation was given for each disturbance of respiratory function. In conclusion, a characteristic respiratory function profile of LCP is proposed, with a restrictive ventilatory disturbance or moderate mixed picture, a DLCO/VA ratio generally normal, almost constant hypoxaemia at rest and improvement or worsening on exercise. CPT = Mean total lung capacity. CV = Mean vital capacity. DS = Standard deviation.

Aged↗
PubMed1984

[Interlobar pneumothorax].

The features of interlobar (intrafissural) pneumothorax are little known. Of the 4 cases reported here, 1 was associated with spontaneous pneumomediastinum and 3 were consecutive to pleurodesis for spontaneous pneumothorax. Interlobar pneumothorax does not occur unless pleural adhesion is present. The diagnosis is confirmed by radiography of the chest which shows an oblong air-clear area prolonged by a fissural line and corresponding, on lateral projection, to the normal fissure. This image should not be confused with that of pneumatocele, which also resolves spontaneously.

Adult↗
PubMed1983

A prospective randomized trial of methotrexate versus cisplatin in the treatment of recurrent squamous cell carcinoma of the head and neck.

A prospective randomized study was conducted to determine the relative effectiveness, toxicity and tolerance of methotrexate (MTX) versus cisplatin (DDP) in patients with recurrent head and neck squamous cell carcinoma. Forty-four patients were randomized to receive either MTX, 40 mg escalated to 60 mg/m2 IV push weekly, or DDP, 50 mg/m2 6 hour infusion days 1 and 8 every 4 weeks. All patients had objectively measurable disease and a performance status greater than 60% (Karnofsky scale). All had been treated with surgery and/or radiotherapy. No patients had prior chemotherapy. Prior treatment, performance status, and site of primary disease were comparable in both groups. Complete and partial objective responses were achieved in 23.5% of the MTX group and 28.6% of the DDP group (P = 0.51). Median duration of response was 84 days in the MTX group and 92 days in the DDP group. Median survival of patients was 6.1 months with MTX and 6.3 months with DDP. Mucositis was noted in 38% of patients in the MTX group (P = 0.001) compared to none in the DDP group. Vomiting occurred in 87% of patients in the DDP group (P less than .0001) compared to 10% of patients in the MTX group. This study demonstrates that in the treatment of recurrent head and neck squamous cell carcinoma, MTX and DDP are equally effective, although MTX appears to be better tolerated.

Carcinoma, Squamous Cell↗
PubMed1983

Steroid-lipid interactions in sonicated dipalmitoyl phosphatidyl choline vesicles: a steady-state and time-resolved fluorescence anisotropy study with all trans-1,6-diphenyl-1,3,5-hexatriene as probe.

The effect of steroid chemical structure on steroid-lipid interaction is studied in sonicated dipalmitoyl phosphatidylcholine vesicles by steady-state and time-resolved fluorescence anisotropy techniques using diphenylhexatriene as probe. A large number of cholesterol derivatives and steroids, some of them being precursors involved in corticosteroids biosynthesis, has been studied. Addition of a polar group on the side chain in carbon-20 or 22 position evokes considerable difference for the interaction with the bilayer. The carbon-22 position appears to be of critical importance. This observation may be relevant for the functioning of mitochondria from steroid producing tissues, where a stereospecific hydroxylation of cholesterol at the carbon-22R position is required for pregnenolone synthesis.

Adrenal Cortex↗
PubMed1983

Photochemical cross-linking of translation initiation factor 3 to Escherichia coli 50S ribosomal subunits.

Translation initiation factor 3 (IF-3) was bound noncovalently to Escherichia coli 50S ribosomal subunits. Irradiation of such complexes with near-ultraviolet light (greater than 285 nm) resulted in covalent attachment of initiation factor 3 to the 50S subunit. Photo-cross-linking attained its maximum level of 40% of that which was noncovalently bound after 90 min of irradiation. Cross-linking was abolished in the presence of either 0.5 M NH4C1 or 0.25 mM aurintricarboxylic acid, indicating that specific binding of initiation factor 3 to the ribosome was a prerequisite for subsequent covalent attachment. Further analysis showed that all the IF-3 was covalently bound to a small number of 50S subunit proteins. The major cross-linked proteins were identified as L2, L7/L12, L11, and L27 by immunochemical techniques. These results are discussed in light of the proposed mechanism for IF-3 function.

Bacterial Proteins↗
PubMed1983

Management of perforation due to colonoscopy.

Six patients who underwent emergency laparotomy for perforations secondary to colonoscopy or polypectomy are described. Three patients had the laceration closed primarily, two required colostomy, and one needed resection. When contamination is minimal and the colon is mechanically prepared, primary closure without diversion is the treatment of choice. Colostomy is rarely indicated and may lead to increased morbidity, in view of the need for closure. However, resection should be considered if suspicion of carcinoma is great. Factors that contribute to perforation include sedation, forceful introduction of the colonoscope, inadequate equipment for hemorrhage control, and prolonged application of electrocoagulation to the colonic wall.

Colonoscopy↗
PubMed1983

A cell surface determinant expressed early on migrating avian neural crest cells.

We have produced monoclonal antibodies against quail ciliary ganglion in an attempt to identify specific markers of this neural crest derivative. One of these antibodies, NC/1, recognizes supportive and neuronal cells of the peripheral nervous system and also most, if not all migrating neural crest cells. We report herein the use of NC/1 to identify crest cells during their migration to their site of final localization. In addition, this antibody may shed light on how the neural crest derived mesectoderm and the peripheral nervous system segregate from one another since the NC/1-defined antigen becomes restricted to the cells of the latter.

Animals↗
PubMed1983

Effect of PEEP ventilation on renal function, plasma renin, aldosterone, neurophysins and urinary ADH, and prostaglandins.

To explore the main factors which could be involved in the fluid retention induced by continuous positive pressure ventilation (CPPV), hemodynamics, renal, and hormonal parameters were measured in seven intensive care patients during three consecutive 60-min periods; one of intermittent positive pressure ventilation (IPPV), one of CPPV (PEEP 10 cmH2O), and finally one of IPPV. During CPPV, a 15% decrease in cardiac output was observed, without alteration in arterial pressure or right atrial transmural pressure. In addition, decreases were observed in urinary output by 34%, glomerular filtration rate by 19%, renal blood flow by 32%, sodium excretion by 33%, and potassium excretion by 26%. There was no change in the fractional excretion of sodium and free water. Institution of PEEP also led to a significant increase in plasma renin activity, plasma aldosterone, and urinary antidiuretic hormone, without significant variation in plasma neurophysins and urinary prostaglandins E and F alpha. All of the changes that occurred during CPPV were reversed when PEEP was withdrawn. It is concluded that the short-term antidiuretic effect of PEEP is mainly due to a hemodynamic impairment of renal function. The water- and sodium-retaining hormonal systems also are stimulated and could participate in the fluid retention during more prolonged respiratory support with PEEP.

Adolescent↗
PubMed1983

Expression of histone genes during heat shock and in arsenite-treated Drosophila Kc cells.

In Drosophila Kc cultured cell lines, heat shock induces an increased synthesis of one of the core histones, H2B. This is accompanied by a reduction in the rate of synthesis of H1 and the other core histones, suggesting a noncoordinated expression of histones during heat shock. Arsenite which has a heat-shock mimicking effect does not induce an increase in the synthesis of H2B. The increased expression of H2B during heat shock shows a temperature dependency similar to that of the low molecular weight heat-shock proteins being observed at temperatures higher than 33 degrees C. A full heat-shock response is observed after a short 15-min shock at 37 degrees C, suggesting a rapid transcriptional response of the H2B gene and possibly a decreased transcription of the other histones and (or) an accelerated decay of their corresponding mRNAs. This increased synthesis of H2B seems under transcriptional control since it can be inhibited, like the other major heat-shock proteins, by the addition of actinomycin D.

Animals↗
PubMed1983

[Embryonal carcinoma and vitelline tumor of the mediastinum. Diagnostic and prognostic value of alpha-fetoprotein levels. A propos of 5 cases].

Five cases are reported of embryonal carcinoma with a vitelline structure more or less predominating. The presentation was of an anterior mediastinal tumour occurring in young men and in three cases there was mediastinal obstruction. The clinical examination, in particular testicular examination, was negative. In each case the level of the alpha-fetoprotein was greater than 1,000 micrograms/l, even post-operatively. The alpha-fetoprotein and HCG-beta should be measured systematically in all cases of anterior mediastinal tumour occurring in young subjects, and would enable a more frequent identification of tumours with difficult histology. The serum levels reflected the changes noted clinically and radiologically. Polychemotherapy bases around cis platinum led to a significant but transitory regression of the tumours. Radiotherapy was ineffective. Surgery was never totally curative.

Adult↗
PubMed1983

[Structural modification of the erythrocyte membrane in genetically hypertensive rats of the Lyon strain].

The rotation activation energy of 16 nitroxystearate spin label inserted in the erythrocyte membrane of genetically hypertensive (LH) and normotensive (LN) Rats from the Lyon strain was measured as a function of the age. This parameter was found significantly increased in the LH Rats compared to their normotensive LN controls. The same phenomenon has been observed previously in the Japanese spontaneously hypertensive Rats.

Animals↗
PubMed1983

[Comparative effects of an alpha 1 and beta 1-2 blocker (labetalol) and a beta-1 blocker (atenolol) in the hypertensive patient].

The effects of a single oral dose and of an 8 week treatment with labetalol--an alpha 1- and beta 1-2-adrenoceptor blocking agent--and with atenolol--a beta 1-adrenoceptor blocking agent--were compared in 52 hypertensives. A single oral dose of atenolol induced a marked bradycardia without decrease in blood pressure. On the contrary labetalol lowered blood pressure but not resting heart rate. After an 8 week treatment both drugs exhibited a similar antihypertensive effect. However labetalol did not decrease heart rate and plasma renin activity as markedly as atenolol did. It was concluded that the alpha 1 blocking properties of labetalol were of importance in the development of the antihypertensive properties that this drug exhibits after a single or multiple administrations.

Adult↗