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Biomedical subjects

G Michel

Publications and source records attributed to G Michel.

At least 397 records · Page 22Linked to original sources
PubMed1987

[Computed tomography of uterine and ovarian cancer].

The authors try to specify the place of Tomodensitometry in utero-ovarian cancers. The examination technique presents no particularities: at best, the interval and the depth of the cuts must be selected. In cervical cancers, the poor appreciation on TDM of adnexal and vaginal involvement renders this examination unsuitable for staging. On the contrary, it is absolutely necessary in order to make the diagnosis of recurrences. In cancers of the body of the uterus, almost always operated on, TDM presents very little interest for the initial work-up except for patients who are difficult to examine or are going to undergo irradiation. As for ovarian tumors, TDM may be useful to detect intra-hepatic metastases before the first operation, to monitor patients undergoing chemotherapy: peritoneal carcinosis is inconstantly detected and TDM cannot replace a second look.

Female↗
PubMed1987

Breast reconstruction without implant: experience of 52 cases.

Reconstruction of the breast (BR) after mastectomy without using a prosthetic implant has always presented a challenge for plastic surgeons, allowing them to avoid complications due to foreign body and to provide a more natural reconstructed breast. Out of 66 women who underwent BR using the rectus abdominis musculocutaneous flap, 52 received no implant. Ten upper rectus (ERF) and 42 lower rectus (TRAM) were the two procedures applied. The ERF has been abandoned due to the 9% rate of complete necrosis encountered among the total series of rectus flap regardless of the implant inclusion. Partial necrosis was also the most frequent complication of the TRAM (28% among those not having received an implant), but the reconstruction was nevertheless possible in all the cases. The TRAM technique produced abdominal sequelae in 45% of the no-implant cases, though it also improved the cosmetic aspect of the abdomen in an equal number of cases, particularly in obese women. Overall cosmetic results were also better for the TRAM without implant than for the ERF (72% good vs. 51%). Moreover the BR without implant could be performed in only 48% of the total ERF, as compared to 93% of the total TRAM. The major advantage of such BR without implant is that it provides a reconstructed breast which appears more symmetrical to the contralateral breast and which remains even after several years of follow-up.

Breast↗
PubMed1987

[Value of magnetic resonance imaging of cancers of the uterine cervix and corpus. Preliminary study apropos of 9 cases of cancer of the corpus and 20 cases of cancer of the cervix].

We studied nine cases of endometrial carcinoma and twenty of cervix carcinoma. Correlation with histology is made after curietherapy in 8 cases of endometrial carcinoma. Tumor is not always seen and particularly when there is no mass effect on macroscopic examination. Myometrial invasion is not seen with accuracy: the interruption of "junctional zone" is not a good sign. The cervix tumors are well seen on T2 sequences before any treatment. There extra uterine extension is difficult to appreciate. The best results of RMI were in the follow-up after radiotherapy. Therefore it appears actually to us the best indication of RMI.

Evaluation Studies as Topic↗
PubMed1986

Interactions of antibiotics of the iturin group with human erythrocytes.

The peptidolipid antibiotics, iturin A and bacillomycin L have a disrupting effect on erythrocyte membrane leading to a simultaneous release of K+ ions and hemoglobin. The formation of ghosts is accompanied by a partial solubilisation of lipid components. Binding experiments with radioactive antibiotics show that about 7 X 10(7) molecules of iturin A and 4 X 10(7) molecules of bacillomycin L are bound to one erythrocyte at the concentration giving 100% hemolysis. This concentration is reduced by about 20% after treatment of erythrocytes by phospholipase A2. Scatchard plots show that the affinity for erythrocyte membrane is higher with bacillomycin L than with iturin A. This difference is probably correlated to the differences in their peptide moieties. The substitution of tyrosyl residue leads to a ten-fold increase of the concentrations giving 100% hemolysis, probably due to a low distribution coefficient of derivatives between the membrane and the solvent. This result and the humped Scatchard curves obtained with both antibiotics may be related to the self-association of the compounds in aqueous solutions.

Anti-Bacterial Agents↗
PubMed1986

Precursors of mesotocin and vasotocin in birds: identification of VLDV- and MSEL- neurophysins in chicken, goose, and ostrich.

Precursors of neurohypophysial hormones are small proteins processed into nonapeptide hormones and neurophysins during axonal transport to the neurohypophysis. In mammals, oxytocin is associated with VLDV-neurophysin and vasopressin with MSEL-neurophysin. In birds, mesotocin and vasotocin are found instead of mammalian oxytocin and vasopressin. From goose, chicken and ostrich posterior pituitary glands, two types of neurophysins related to mammalian VLDV- and MSEL-neurophysins, respectively, have been identified by their N-terminal sequences. It is assumed that, as in mammals, hormonal peptide and the first 9 residues of the corresponding neurophysin are encoded by a common exon and that mesotocin and vasotocin, evolutionary predecessors of oxytocin and vasopressin, are associated in the precursors with VLDV-neurophysin and MSEL-neurophysin, respectively.

Amino Acid Sequence↗
PubMed1986

New treatment procedure for stage I endometrial adenocarcinoma.

A series of 80 Stage I adenocarcinomas of the endometrium is described. Treatment is based on a more frequent use of surgery and there is greater individualization of the treatment procedure, which combines vaginal or uterovaginal Curie therapy and surgery. Overall 5 year survival rates are 82%, compared with 91.5% for patients having been treated with Curie therapy plus surgery. The patient's age and the size of the uterus were found to be significant from the prognostic standpoint. However, other factors, such as histological type and grade, penetration into the myometrium, and lymph node involvement did not seem especially important. Treatment described here appears to give better results than that used previously; survival rates are higher and complications of treatment are negligible.

Adenocarcinoma↗
PubMed1986

Isolation and characterization of an O-methylglucose-containing lipopolysaccharide produced by Nocardia otitidis-caviarum.

The low-Mr lipopolysaccharide produced by Nocardia otitidis-cavirum is composed of 6-O-methyl-D-glucose (11 mol), D-glucose (8 mol) and 3-O-methyl-D-glucose (1 mol). Glyceric acid was also found as a constituent. Methylation and periodate oxidation analyses suggested that the backbone was formed by (1----4)-linked glucose and O-methylglucose residues. Glucose (1 mol) and 6-O-methylglucose (1 mol) served as branching points. Acetic acid was the major acyl substituent esterifying glucose residues. The lipopolysaccharide was isolated from the cytoplasmic fraction. Several other Nocardia strains were examined; all possessed the same lipopolysaccharide in their extracts.

3-O-Methylglucose↗
PubMed1986

Chemical composition of antigen 60 from Mycobacterium bovis BCG.

Antigen 60 (A60), the main thermostable immunogen of tuberculin and PPD, has been purified from Mycobacterium bovis BCG cytoplasm, and identified by crossed immunoelectrophoresis with anti-BCG polyclonal antiserum. Two A60 fractions, free lipids and lipid-conjugated compounds, have been recognized. The free lipids represented about 30% (dry weight), and consisted essentially of C16-C18 fatty acids, and of phosphatidyl-inositol-mannosides. Lipoconjugates, upon DEAE-cellulose chromatography and gel filtration, yielded two main fractions of neutral and polar components. Chromatography of delipidated and deproteinized A60 on Sephadex G-100 yielded: a high molecular weight fraction (Al, 18%, a lipoglucan of congruent to 10(6)), and a low molecular weight fraction (B, 10%, a lipopeptidoglycan of congruent to 10(4)) containing mannose, glucose, and small amounts of arabinose. The polysaccharide moieties of fractions Al and B were submitted to acetylation, methylation, and acid hydrolysis, and the structure of the hydrolysed polymer was deduced by combined gas chromatography/mass spectrometry analysis. The results indicated a branched structure involving 1,4-, 1,6-, and 1,4,6-linked D-gluco- or D-manno-pyranosyl residues. Glucan- and peptidoglycan-bound fatty acids were identified as saturated (C16-C18) and monounsaturated linear acids (C12-C18). Immunodiffusion on agarose gel indicated that delipidation and proteolysis did not suppress the ability of A60 to yield immunoprecipitates with anti-A60 antiserum. The high polymer fractions obtained by chromatography on DEAE cellulose and Sephadex G-100 were also reactive. It is concluded that A60 is made of free lipids and of lipopeptidoglycans of high molecular weights (10(6)-10(7)) endowed with immunogenic properties.

Antigens, Bacterial↗
PubMed1986

Noninvasive and quantitative 19F nuclear magnetic resonance study of flucytosine metabolism in Candida strains.

19F nuclear magnetic resonance was used for a noninvasive and quantitative study of flucytosine (FC; 5-fluorocytosine) metabolism in two strains of Candida albicans and one strain of Candida tropicalis with various susceptibilities to FC. Three intracellular fluorinated metabolites were detected in the highly susceptible strain, F-nucleotides (Fnt), F-nucleosides, and 5-fluorouracil (5FU). Fnt were partially converted into 5FU when the spectra of the yeasts were recorded at 37 degrees C without perfusion, but the intensities of the signals were not modified at 4 or 37 degrees C if the cells were perfused. In the acid extract, the Fnt signal was resolved into three distinct peaks; none of them was attributable to 5-fluoro-2'-deoxyuridine-5'-monophosphate. The same signals were detected in the partially resistant strain, but only 5FU was observed in the highly resistant strain; the resistance of the latter strain therefore was primarily due to a defect in UMP pyrophosphorylase. At the end of the incubation period, only FC and released 5FU were present in the culture media. The concentration of the intracellular fluorinated metabolites was increased if the strain was susceptible to FC. The total amount of metabolized FC was very similar for the highly susceptible and the partially resistant strains, but the percentage of Fnt was much higher in the former (38%) than in the latter (8%); the mild resistance of the partially resistant strain therefore was attributed to the decreased activity of UMP pyrophosphorylase.

Candida↗
PubMed1986

Effect of various growth conditions on spore formation and bacillomycin L production in Bacillus subtilis.

Bacillomycin L is produced by Bacillus subtilis NCIB 8872 in the stationary phase; it is excreted into the culture medium, without prior accumulation in the bacterial cells. The production of bacillomycin L is largely dependent on the composition of the culture medium. The action of specific inhibitors of sporulation, netropsin and diethyl malonate, on antibiotic synthesis is dependent on the composition of the culture medium. Although they occurred at the same time, there appears to be no direct correlation between sporulation and antibiotic synthesis.

Bacillus subtilis↗
PubMed1986

Nonparallel secretion of enzymes by the rabbit pancreas.

Since nonparallel secretion of enzymes by the exocrine pancreas has been demonstrated with several experimental models, we were interested in verifying a recent claim that enzyme secretion remained strictly proportional (parallel) upon stimulation of the in vivo rabbit pancreas. Pancreatic juice was collected by extraduodenal cannulation of the pancreatic duct, in two different protocols. In the first protocol the administration of pentobarbital induces a mild anesthesia. Under this condition, amylase and chymotrypsin secretion remained parallel after cholecystokinin stimulation. In a second protocol, a deeper and constant anesthesia was attained with Fluothane resulting in a lower basal protein output than in the first protocol. Pancreatic secretion was collected under intravenous secretin perfusion (4.5 clinical units X kg-1 X h-1). After stabilization and basal collection periods, pancreatic secretion was stimulated with an i.v. bolus injection of either cholecystokinin (2 Ivy dog units/kg), caerulein (0.1 micrograms/kg), or carbachol (6 micrograms/kg). Upon stimulation of the pancreas, protein output increased an average of 30-fold and there was a concomitant 20-25% decrease in the ratio of the specific activities of amylase to chymotrypsin which resulted from a greater increase in the specific activity of chymotrypsin in pancreatic juice after stimulation of secretion. Thus, under appropriate conditions, nonparallel secretion of enzymes by the exocrine pancreas can be demonstrated in yet another experimental model. Furthermore, the proportion of amylase and chymotrypsin activities in pancreatic juice are once more shown to be dependent, up to a threshold, upon the rate of protein output by this exocrine gland.

Amylases↗