Biomedical subjects
Publications and source records attributed to G Michel.
Clear cell adenocarcinoma (CCA) of the vagina and the cervix is a rare tumour. Since 1971 its increased incidence has been ascribed to intrauterine exposure to diethylstilboestrol (DES) and as a consequence the US Food and Drug Administration has banned the use of all DES-type medications during pregnancy. We report a case of CCA demonstrated by magnetic resonance imaging.
Dithranol is highly effective in the treatment of psoriasis, but the exact mechanism of action is not known. Since persistent expression of epidermal growth factor (EGF) receptors in psoriatic epidermis is assumed to have pathogenetic significance, we have studied the effects of dithranol on EGF binding to the human epidermal cell line SCL-II. After treatment of cells with dithranol or its therapeutically inactive oxidation product, danthrone, radioligand binding assays were performed with 125I-EGF. In therapeutically active concentrations (0.25-1 micrograms/ml) dithranol induced a decrease in EGF binding in a dose dependent manner. Danthrone was inactive. The inhibition occurred after a latency period of 6 h and reached its maximum at 24 h. At the concentration of 1 microgram/ml, the drug led to approximately a 70% decrease in the number of specific high-affinity EGF receptors (Bmax), whereas receptor affinity (Kd) showed no change. The down-regulation of EGF receptors on epidermal cells by dithranol may contribute to its antipsoriatic action.
The Cancer Registries have been operational in the South Pacific since 1958 (Papua New Guinea), Fiji (1965) and New Caledonia (1977) and complete cancer incidence rates are available, based on histologic data. We studied 97 melanomas, histologically confirmed, which were diagnosed in New Caledonia from 1973 to 1991. New Caledonia is located in the same latitude as Queensland in Australia, known for having the highest incidence of melanoma in the world. Standardised incidence rates (world population) were 9.82 and 7.65/100,000/year for European males and females, compared to 1.65 and 1.05 for Melanesian and Polynesian males and females. The European population is exposed and Melanesians/Polynesians are relatively protected as are black Americans or Africans. The mixed populations are protected, but no study is available as to the exact proportion of mixed people (20%?) in the entire population. For Europeans, among males, the main areas in which melanomas occur are the trunk (45%) the arm (13%) and the leg (13%). Among females, the main areas are the leg (27%), the trunk (20%) and the head (18%). Screening for melanoma has been more effective in the last 6 years, a period in which we diagnosed half the total cases and generally at earlier stages. Prognosis was poor for this period (1973-1991): the five year survival rates were 64% +/- 8%, not as good as in Europe or Australia, but these lesions were diagnosed between 1973 and 1985 and were generally more invasive. A better prognosis will probably be observed in a few years, and another evaluation of melanoma screening should be made in the future as well the study of precursors and early lesions.
The effect of exposure of human epidermal keratinocytes to ionizing radiation, both in vivo and in vitro, on the expression of the epidermal growth factor receptor (EGF-R) was studied on the protein, mRNA, and functional levels. Quantitative fluorometry of short-term organ cultures incubated with a monoclonal antibody against human EGF-R revealed a dose-dependent increase of EGF-R expression 24 h after irradiation with 4 and 6 Gy, with an additional increase after 48 h. In biopsy specimens from patients undergoing radiation therapy a markedly increased expression could be determined by quantitative fluorometry during radiation therapy which wa still considerably above the baseline level 4 weeks after termination of treatment. Radioligand binding assays demonstrated a 50% increase in 125I-EGF binding to primary keratinocytes and A431 cells, at doses of 1 Gy, with a further increase after 72 and 96 h. Northern blots were performed with total RNA from two human epidermal cell lines (SCLII and A431). In A431 cells, increased EGF-R transcript levels could be detected 48 h after irradiation. In cells of the SCLII cell line, EGF-R expression was not affected by irradiation. These results were confirmed by semiquantitative polymerase chain reaction of primary cultured keratinocytes, demonstrating an increase of transcripts of EGF-R 24 h after irradiation with single doses of 6 Gy. Thus exposure to ionizing radiation leads to an increased expression of functionally intact EGF-R in human keratinocytes, at the protein and mRNA levels, both in vitro and in vivo; we hypothesize that this effect is part of a stress program of epidermal cells in response to ionizing radiation, ensuring rapid repopulation of irradiated areas.
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The interaction type of chlorhexidine digluconate/chlorocresol association (foaming solution DC 102/1, Laboratoires Pierre Fabre Médicament) have been studied according to the chess-board method, on microplate, by determining MBC (Minimal Bactericidal Concentrations) (or MFC (Minimal Fungicidal Concentrations)) adjusted to T 72-150 AFNOR norm (dilution-neutralization, contact 5 mn) and computation of FBC (or FFC) Index. Trials were carried out against 18 hospital strains (Staphylococcus epidermidis, Staphylococcus aureus, Propionibacterium acnes, Candida albicans) and against 4 strains of the AF-NOR norm. MBC of chlorhexidine, against Staphylococci were included between 6.25 and 25 micrograms/ml, and between 25 and 200 micrograms/ml against the others strains. MBC of chlorocresol were included between 800 and 3,200 micrograms/ml. Against the 22 tested strains, 18 synergistic interactions (FBC Index < or = 0.75) were observed, with 4 to 8 reducing factor for chlorhexidine, and > or = 2 for chlorocresol. No antagonism was noted (maximal FBC Index = 1).
The nervous supply of the teat and udder skin of the bovine was examined by means of the AChE-reaction. In comparison to the silver impregnation method, a rich subepidermal fibre-network with intra-epithelial nerve endings and, especially, a strongly developed nerve fibre meshwork associated with muscle fibres was seen.
The effect of six representative cell wall-active antibiotics upon the membrane proteins of Staphylococcus aureus CIP 65-25 was studied. The profiles of whole membrane proteins and of penicillin-binding proteins of strain CIP 65-25 grown on an antibiotic-free medium were analysed and compared with those of nine other S. aureus strains. Both profiles were found to be very similar for all strains examined. Cell wall-active antibiotics brought about definite changes dealing with a few membrane proteins of strain CIP 65-25. Some polypeptide bands of the control profiles decreased or vanished after exposure to antibiotics whereas others rose only in antibiotic-treated bacteria. None of these modified polypeptides was a penicillin-binding protein. Their possible involvement in the antibacterial effects of antibiotics or in the determinism of bacterial resistance to antibiotics is discussed.
From 4 cases recently seen at the Institut Gustave-Roussy, this report describes the pathological and evolutive features of benign glandular inclusions in inguinal, pelvic or abdominal lymph nodes. These lesions are defined by the presence of tubular formations in lymph nodes, lined by a single layer of epithelium which is cuboidal or columnar and resembled that of tubal epithelium with ciliated, secretory and intercalary cells. In most cases, benign glandular inclusions in lymph nodes still quiescent. In rare instances, they may proliferate and become papillary. The association of proliferating glandular inclusions in lymph nodes with borderline tumor of the ovary raises the problem of their primary or metastatic origin. However, their pathological features argues for a primary origin in lymph nodes. Thus, we think that a metastatic potential of borderline tumors of the ovary is not supported by any convincing argument.
The authors report the successive occurrence of an interdigitating-cell sarcoma and a lymphoblastic lymphoma in an 8-year old child. The observation is documented by immunophenotype and genotype. The link between the two malignancies is discussed.
The biosynthesis of bacillomycin D, an antibiotic containing a beta-amino fatty acid and a peptide moiety with asparagine, glutamic acid, serine, proline, threonine, and tyrosine, was studied by incubating the Bacillus subtilis producer with various 14C-labelled precursors. Sodium acetate was incorporated into beta-amino fatty acids of bacillomycin D, and asparagine was the best precursor of the peptidic moiety. The kinetics of the incorporation of radioactive substrates into bacillomycin D and into beta-amino fatty acids show that the lipid and the peptide moieties of the antibiotic were synthesized at the same stage of growth of the bacteria. Comparing the effects of different inhibitors on the incorporation of radioactive precursors, the bacillomycin D and beta-amino fatty acids biosyntheses are discussed in relation to the biosyntheses of proteins, lipids and with sporulation.
Fifteen S/S children with severe SCD were transplanted with marrow from HLA identical siblings. All developed frequent (> 3/y) vaso-occlusive crises (VOC) associated with recurrent acute chest syndrome episodes (n = 10), osteitis (n = 3), osteonecrosis (n = 3), strokes (n = 3) or frequent massive deglobulisation (n = 2). Two children undergone splenectomy, two were chelated and two had an erythroid allo-immunization. Ethnic origins were from various countries in Africa (n = 11), North-Africa (n = 3) or West Indies (n = 1). At BMT, they were 2y 3m to 14y 9m old (mean: 8y 7m). Donors were AS (n = 11) or AA (n = 4). At first, various conditioning regimens were used consisting of busulfan (BU) plus Cyclophosphamide (CY) at different doses: CY:200 mg/kg (n = 13) or 260 mg/kg (n = 2); BU: 14 mg/kg (n = 1), 16 mg/kg (n = 9), > 16 mg/kg (n = 5); one patient received also TLI and the last two anti-thymoglobulin (ATG): 20 mg/kg. GVHD prophylaxis was CSA alone (n = 4) or CSA plus short-term MTX (n = 11). Median follow-up is 28 months (5 m to 53 m). All patients had an engraftment (d12 to d32) with a stable total chimerism in 10/14 patients. In the 4 others, partial chimerism was observed: one patient had a early and progressive rejection of his graft but is doing very well (35 m follow-up) without any manifestation of SCD, with a high stable 22% Hb F level.(ABSTRACT TRUNCATED AT 250 WORDS)
Fourteen S/S children with severe SCD were transplanted with marrow from HLA identical siblings. All developed frequent (> 4/y) vasoocclusive crises (VOC) and recurrent acute chest syndrome episodes (n:10), osteitis (n:3), osteonecrosis (n:3), strokes (n:3) or frequent massive deglobulisation (n:2). Two children undergone splenectomy, 2 were chelated and 2 had erythroid allo-immunization. Ethnic origins were from various countries in Africa (n:10), North-Africa (n:3) or West Indies (n:1). At BMT, they were 2y 3m to 14y 9m old (mean:8y 7m). Donors were AS (n:11) or AA (n:3). At first, various conditioning regimens were used consisting of busulfan (BU) plus Cyclophosphamide (CY) at different doses: CY:200 mg/kg (n:12) or 260 mg/kg (n:2); BU:14 mg/kg (n:1), 16 mg/kg (n:9), > 16 mg/kg (n:4); 1 patient received also TLI and one other antithymoglobulin (ATG): 20 mg/kg. GVHD prophylaxis was CSA alone (n:4) or CSA plus short-term MTX (n:10). Median follow-up was 23 months (8 m. to 48 m.). All patients had an engraftment (d13 to d32) with a stable total chimerism in 10/14 patients who are cured. In the 4 others, partial chimerism was observed: one patient had a early and progressive rejection of his graft but is doing very well (28 m. follow-up) without any manifestation of SCD, with a high stable 22% Hb F level. One patient developed an aplastic anaemia 15 m after BMT: a second BMT was achieved 21 m after the first one with engraftment and total chimerism. Two patients have a relatively stable partial chimerism with still undergoing CSA therapy (11 m. and 23 m. follow-up).(ABSTRACT TRUNCATED AT 250 WORDS)
In a double-blind study, 198 patients experiencing recurrent herpes orofacialis were randomly assigned to treatment with either tromantadine hydrochloride (ViruMerz Serol, CAS 53783-83-8) or aciclovir. All patients performed an up to 5-day course of topical treatment beginning on average within 2 h after the first signs of recurrence. The herpes efflorescences and symptoms were assessed daily by the same physician for 14 days, except on weekends, and by the patients each day during the whole observation time. Rapid healing was achieved with both medications. Efficacy was assessed by rating the course of vesicle eruptions, duration until beginning of incrustation and the clinical course of the symptoms (burning, tension, pain). Equivalence between the medication groups was shown by comparative analysis of all evaluation criteria. The global efficacy and tolerability of both medications was rated by the physician as well as by the patients as "good" or "very good" in more than 80% of the cases. The results of this trial show equivalence of both medications in the treatment of recurrent herpes orofacialis, and confirm the good dermal tolerability of the drugs.
Mesenteric Cystic Lymphangiomas is a rare benign tumor. The first case was described after an autopsy in 1507 by Benivieni, an anatomist from Florence. In 1880 by Tillaux. Since then many cases have been described. None of these cases is associated with a non specific necrosis due to Bauhins' valvula compression; in the following lines we are going to describe this exceptional case.
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The effects of fosfomycin on penicillin-binding proteins (PBPs) were studied on the methicillin-resistant Staphylococcus aureus strain CIP (Collection de l'Institut Pasteur, Paris, France) 65-25 and on a methicillin-susceptible S. aureus strain CIP 65-6. The combinations of fosfomycin and oxacillin were synergistic, additive or antagonistic, depending on antibiotic concentrations. Fosfomycin induced modifications of the PBP profile of the two strains studied. In particular, it increased the expression of PBP2. This suggested that this protein is inducible; the only PBP not affected by fosfomycin was PBP3.
Bacillomycin D is an antifungal lipopeptide produced by B. subtilis. The formation of the peptidyl bonds of bacillomycin D occurs non-ribosomally, as demonstrated by the use of chloramphenicol, an inhibitor of protein biosynthesis. Amino acid-activating enzymes were found in B. subtilis cell lysates purified by affinity chromatography on a gel containing L-Pro, an amino acid of bacillomycin D. Presence of ATP during this purification increases the binding of enzymatic proteins and their activity. An enzyme, with an apparent molecular weight of 230 kDa, catalyzed ATP-PPi exchange reactions, which were mediated by specific amino acids, corresponding to a partial sequence of bacillomycin D.