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Biomedical subjects

G Michel

Publications and source records attributed to G Michel.

At least 325 records · Page 18Linked to original sources
PubMed1990

[Characteristics of the occurrence of hematotoxic side effects of cytostatic drugs--results of a retrospective 10 year study of a district hospital].

From 1978 to 1988 in 77 patients of a district hospital, 58 females and 19 males, with malignant tumours or haemoblastoses a therapy with cytostatic agents was finished. A retrospective study analyses characteristics of haematotoxic side effects of cytostatic agents, which despite usual dosage according to the valid guide-lines have appeared in this patient population. According to this the granulocytopoiesis is injured most frequently and most severely. In one third of all patients under influence of cytostatic agents the number of the segment-nuclear granulocytes in the peripheral blood decreased deeper than 0.5 Gpt/l (severe neutropenia). In toxic influences on the thrombopoiesis slight and medium degrees of severity are dominating. Lesions of the erythropoiesis are apparently more infrequent, though they are more difficult to be proved. Further characteristics in the occurrence of severe neutropenias (date, dependence on age, pharmacological aspects) are demonstrated and discussed.

Aged↗
PubMed1990

[Treatment of invasive epithelioma of the uterine cervix: the experience at the Institut Gustave-Roussy].

The therapeutic protocole used at the Gustave Roussy Institute for invasive epithelioma of the uterine cervix rests, for limited forms (T1B-T2 proximal), on combined radiology and surgery. This include the recently introduced supraradical lymphadenectomy extended to the lumboarotic lymph nodes, first-line surgery in young women to preserve the ovarian function and postoperative chemotherapy for extra-pelvic N+ forms. In extensive forms (distal T2 and T3), the treatment of choice still is radiotherapy with external irradiation associated with curietherapy. T3 forms with urinary tract involvement now benefit from interventional radiology techniques. The basic treatment of T4 forms involving the bladder and/or rectum remains radiotherapy, but wide surgical resection (exenteration) is still indicated in some cases. The treatment of particular forms (post-hysterectomy cervix, uterine prolapse, pregnancy) relies on techniques that are suitable for each individual situation.

Cancer Care Facilities↗
PubMed1990

Identification of two types of neurophysins in Xenopus laevis neurointermediate pituitary homologous to mammalian MSEL- and VLDV-neurophysins.

UNLABELLED: Xenopus laevis neurophysins have been purified from neurointermediate pituitaries through high-pressure reverse-phase liquid chromatography and their N-terminal amino acid sequences have been determined by microsequencing. Two types of neurophysins, corresponding to mammalian MSEL- and VLDV-neurophysins, have been distinguished. A strong homology exists between neurophysins of Xenopus (Pipidae), frog (Ranidae) and toad (Bufonidae). Xenopus MSEL-neurophysin, as frog MSEL-neurophysin, has a high molecular mass suggesting that the C-terminal domain of the vasotocin precursor is not processed in contrast to the two-step processing observed for mammalian vasopressin precursor. ABBREVIATIONS: Mammalian neurophysins are termed MSEL- and VLDV-neurophysins according to the nature of residues in positions 2, 3, 6 and 7 (one-letter symbols for amino acids).

Amino Acid Sequence↗
PubMed1990

Antibacterial activity of the leaves of Phyllanthus discoideus.

The lyophilized aqueous extract (LWE) from the leaves of Phyllanthus discoideus was found to show an antibacterial activity. The alkaloid fraction obtained from LWE inhibited the growth of Escherichia coli and Enterococcus faecium (MIC = 1.6 mg/ml), Pseudomonas aeruginosa (MIC = 0.78 mg/ml), Staphylococcus aureus and Mycobacterium smegmatis (MIC = 0.2 mg/ml). Among the alkaloids identified, viroallosecurinine and securinine showed a high activity. Viroallosecurinine exhibited a MIC of 0.48 micrograms/ml for Ps. aeruginosa and Staph. aureus. This alkaloid is bactericidal since the yields of MIC/MBC were less than 1. The MIC of securinine was 0.500 mg/ml for E. coli, Staph. aureus and Myc. smegmatis. These effects of Phyllanthus discoideus leaf extracts support some of the local uses of the plant in traditional therapy.

Alkaloids↗
PubMed1990

[Cerebral infarction in pernicious malaria. Diagnostic value of computed tomography].

Case report of a severe form of neuropaludism, contracted in a territory with Plasmodium falciparum completely insensitive to chloroquine. CAT Scan views displayed a small brain infarction. Complete recovery was obtained with a treatment including quinine, tracheal intubation and ventilatory support, sedation with barbiturates. CAT Scan views demonstrated a complete regression of cerebral lesions.

Adult↗
PubMed1990

Non-mammalian "big" neurophysins--complete amino acid sequence of a two-domain MSEL-neurophysin from goose.

Vasotocin-associated neurophysin (MSEL-neurophysin) has been purified from goose neurohypophysis through molecular sieving and high-pressure reverse-phase liquid chromatography (HPLC). The protein has a molecular mass (measured by SDS-polyacrylamide gel electrophoresis) of 17 kDa in contrast to 10 kDa found for the mammalian MSEL-neurophysins. Complete amino acid sequence (131 residues) has been determined mainly through tryptic or staphylococcal proteinase peptides derived from carboxyamidomethylated neurophysin, isolated by HPLC and microsequenced. N- and C-terminal sequences have been established by Edman degradation or action of carboxypeptidase Y, respectively, applied on the native protein. Goose MSEL-neurophysin is homologous to the two-domain "big" MSEL-neurophysin previously identified in the frog. It appears that in non-mammalian tetrapods, namely birds and amphibians, the proteolytic processing of the pro-vasotocin involves only one cleavage, releasing the hormone moiety and a "big" neurophysin with two domains homologous to mammalian MSEL-neurophysin and copeptin, respectively. Comparison of the avian protein with its mammalian and amphibian counterparts reveals that the first half of the polypeptide chain is evolutionarily much less variable than the second and that the goose protein resembles the frog protein much more than the mammalian one.

Amino Acid Sequence↗
PubMed1990

Complete amino acid sequence of goose VLDV-neurophysin. Traces of a putative gene conversion between promesotocin and provasotocin genes.

Goose VLDV-neurophysin (mesotocin-associated neurophysin) has been purified from posterior pituitary glands through molecular sieving on Sephadex G-75 and high-pressure reverse-phase liquid chromatography on Nucleosil C-18 columns. Despite apparent molecular mass of unreduced VLDV-neurophysin measured by polyacrylamide gel electrophoresis with sodium dodecylsulfate appeared near 17 kDa, this value fell to 11 kDa after reduction with mercaptoethanol, suggesting the existence of a homodimer. Complete amino acid sequence (93 residues) of goose VLDV-neurophysin has been determined. N- and C-terminal sequences of the protein have been established by Edman degradation (microsequencing) and use of carboxypeptidase Y, respectively. Peptides derived from oxidized or carboxamidomethylated neurophysin by trypsin or staphylococcal proteinase hydrolyses have been isolated by high-pressure liquid chromatography and microsequenced, allowing determination of the complete sequence. Comparison within the vertebrate VLDV-neurophysin lineage, namely goose VLDV-neurophysin to mammalian VLDV-neurophysins and to deduced toad VLDV-neurophysin, reveals a residue insertion between positions 66 and 67 in the nonmammalian VLDV-neurophysins. When goose MSEL-neurophysin (vasotocin-associated neurophysin) and goose VLDV-neurophysin are compared to their bovine counterparts, identical substitutions are found in positions 17 (Asn in both goose neurophysins instead of Gly in both ox neurophysins), 18 (Arg instead of Lys), 35 (Tyr instead of Phe), and 41 (Thr instead of Ala). Identity of the sequences 10-74 in both ox neurophysins has been explained by partial gene conversion between oxytocin and vasopressin genes, and identical substitutions in both goose neurophysins might reveal a similar gene conversion between mesotocin and vasopressin genes in birds.

Alkylation↗
PubMed1990

Evaluation of the activity of four antimicrobial agents using an in vitro rapid micromethod against oral streptococci and various bacterial strains implicated in periodontitis.

The activity of various antibacterial agents (amoxicillin, josamycin, doxycycline and metronidazole) was established in vitro using a rapid micromethod. The activity of these agents, which are widely used in oral medicine, was evaluated against microorganisms responsible for periodontitis and bucco-dental infections. Their action against alpha-hemolytic streptococci (including pneumococci) which make up the majority of the indigenous oral flora was also tested. Amoxicillin was found to be effective against all the strains tested. Doxycycline was active against periodontal bacteria, but not against 50% of the streptococcal flora. Josamycin was found to be effective against streptococci, but appeared without effect on Eikenella corrodens and Actinobacillus actinomycetemcomitans. Metronidazole, inactive against streptococci, displayed greater activity towards the strict anaerobes. The use of these antibiotics for the treatment of bucco-dental infections, especially periodontitis, is discussed. For periodontitis and periodontal suppurations, antimicrobial agents present a valuable adjunct to local treatments such as scaling or rootplaning. This may prevent more serious infections such as endocarditis that can develop after tooth extraction.

Actinobacillus↗
PubMed1990

Specific inhibition of iturin biosynthesis by cerulenin.

Cerulenin, an inhibitor of fatty acid synthesis, inhibits the biosynthesis of iturin by Bacillus subtilis. With a cerulenin concentration of 2 micrograms/mL, 50% inhibition was achieved. At this concentration, cerulenin does not affect growth or total protein synthesis but does inhibit the incorporation of sodium [14C]acetate, [14C]myristic acid, and [14C]asparagine into iturin. Since cerulenin is known to block the condensation of malonyl-CoA subunits in the formation of fatty acids, the inhibition of iturin and beta-amino acid syntheses by cerulenin is discussed in relation with lipid synthesis.

Acetates↗
PubMed1990

Interaction of iturin A, a lipopeptide antibiotic, with Saccharomyces cerevisiae cells: influence of the sterol membrane composition.

The binding of the membrane-active lipopeptide antibiotic iturin A to yeast cells was studied using radioactive iturin A. Saccharomyces cerevisiae had a maximum binding capacity of 5.6 x 10(9) molecules per single cell. The Scatchard plot of binding showed a biphasic profile, with a lower dissociation constant for small concentrations of iturin A. The break of slope at 30 microM iturin A corresponds to the micellization of antibiotic in solution. The binding is also dependent on the nature of the sterol present in the membrane. A mutant yeast strain with a membrane containing cholesterol instead of ergosterol showed the highest affinity for iturin A and the highest sensitivity to this antibiotic, as measured by K+ ion release. In contrast the presence of stigmasterol increased the resistance of the cells to iturin A.

Anti-Bacterial Agents↗
PubMed1990

[Experimental udder infection with Escherichia coli. 1. The behavior of selected clinical, hematological and other parameters concerned with milk composition].

Four cows with clinically intact udders in high lactation were intracisternally infected by a pathogenic field strain of Escherichia coli. Infections were induced by quarters and with time intervals. Hence, when the animals were slaughtered six hours from beginning of the experiment, epithelial samples could be collected from cisternal walls and lactiferous ducts which, by the time of sampling, had been in contact with pathogens for one, four, and six hours. Highly acute mastitis began to develop two hours from experimental infection and exhibited typical clinical symptoms, including general disorders, unambiguous alterations to the white blood count, and changes in milk composition. These changes were typical of acute toxin action on the udder quarters. Concomitant reactions of non-infected control quarters, detectable by clinical manifestations or by laboratory diagnosis, were not observed.

Animals↗
PubMed1990

[Experimental udder infection with Escherichia coli. 2. Morphological changes of the epithelium in the area of the glands of the milk cistern and the large milk ducts].

Optical light, transmission, and scanning electron microscopy were used in investigations of epithelia in the glandular region of the milk cistern and greater lactiferous ducts and yielded the following findings, four and six hours from infection: degeneration and necrosis of epithelial cells, intraepithelial foreign cell infiltration (neutrophilic granulocytes, lymphocytes, macrophages), intra-epithelial oedema and locally delimited epithelial loss. The lesions differed by intensity in various regions, so that a distinction could be made among five froms of epithelial alterations. The epithelial cells revealed their capability of absorbing pathogenic material and storing it in cytoplasmic vacuoles. This was considered to reflect active involvement of epithelium in antibacterial defence, and consequently, to reflect the role played by epithelium as a defence barrier in the milk cistern and greater lactiferous ducts.

Animals↗
PubMed1990

[Experimental udder infection with Escherichia coli. 3. Morphological changes directly to subepithelially situated structures in the area of the glands of the milk cistern and the large milk ducts].

Alterations were recorded from capillaries and connective tissue by means of optical light and electron microscopy in investigations of subepithelial structures, following experimental Escherichia coli infection. These alterations led to an impairment of the blood-udder barrier and thus to increased extravasation of cells (especially neutrophilic granulocytes). They were found to accumulate in subepithelial connective tissue and, eventually, to penetrate in high quantity the epithelium proper, and, consequently, to be considerably involved in alterations to the latter.

Animals↗
PubMed1990

[Experimental udder infections with Escherichia coli. 4. Discussion of the pathogenesis of acute mastitis].

The correlations among findings obtained from experimental Escherichia coli udder infection and reported in the three previous communications are discussed in this paper. The defence capabilities elucidated included specific and unspecific activities of non-epithelial cells, primarily neutrophilic granulocytes, macrophages, lymphocytes, plasma cells, and mast cells, as well as the capability of epithelial cells proper of absorbing pathogenic material from lumens of lactiferous ducts and milk cisterns and of storing such material within intracytoplasmic vacuoles. Hence, alterations in the course of pathogenesis of acute coli mastitis were found to be of complex nature and could be properly followed up by their morphological patterns.

Acute Disease↗
PubMed1990

Mycosubtilins B and C: minor antibiotics from mycosubtilin-producer Bacillus subtilis.

Mycosubtilins B and C were isolated from the culture medium of Bacillus subtilis. The acid hydrolysates of these new antifungal antibiotics, like mycosubtilin, contain alpha-amino acids (Asp3, Glu1, Pro1, Ser1 and Tyr1) and a mixture of iso-C16, n-C16, iso-C17 and anteiso-C17 beta-amino acids. Mycosubtilins B and C differ by the presence of a carboxyl group and of a carboxymethyl group, respectively, instead of a carboxamide group in previously described mycosubtilin.

Amino Acid Sequence↗
PubMed1990

Coproduction of surfactin and iturin A, lipopeptides with surfactant and antifungal properties, by Bacillus subtilis.

Of the 13 strains of Bacillus subtilis tested for the coproduction of the lipopeptide surfactin and the antifungal lipopeptides of the iturin family, only 1 produced both lipopeptides with a high yield. The cultures were made in a synthetic medium. Several L-amino acids and various carbon sources were good substrates for the lipopeptide production. The maximum yield of surfactin was about 110 mg/liter and that of iturin A about 39 mg/liter/absorbance unit for the best strain, B. subtilis S 499.

Amino Acid Sequence↗
PubMed1990

[Acute lymphoblastic leukemia in children. Results of a protocol including bone marrow transplantation during the first remission in high-risk forms for relapse].

Ninety-two previously untreated children with ALL were admitted to the same institution between November 1984 and November 1988. According to early prognostic factors, patients were divided into 3 groups: group 1 at "low risk" for relapse (n = 18), group 2 at "intermediate risk" (n = 62) and group 3 at "high risk" (n = 12). Every patient received an 8 week-long induction chemotherapy; after CNS prophylaxis, groups 1 and 2 children received a consolidation chemotherapy and then a classical maintenance treatment. Group 3 patients were selected to receive a bone-marrow transplantation during their first remission because of the presence, at diagnosis, of at least one of the following criteria: hyperleukocytosis greater than 100,000 (7 cases), translocation t(1;19) and t(4;11) (2 cases), adolescents (2 cases), no remission at day 30 (2 cases). Ninety-one of 92 children achieved a complete remission and none died during induction therapy. Probability of leukemia-free survival at 4 years is 73 +/- 7% for the whole patient population and 95%, 71% and 60% for patients of groups 1, 2, and 3 respectively. Persistence or disappearance of leukaemic cells in bone marrow after the initial 15 days of chemotherapy appears to influence the probability of a leukemia-free survival.

Actuarial Analysis↗