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Biomedical subjects

A Le Faou

Publications and source records attributed to A Le Faou.

At least 19 recordsLinked to original sources

Hepatitis C after renal transplantation: histopathological correlations.

This study evaluates the correlations between liver histology, cytolysis, cryoglobulinaemia, co-infection with hepatitis B virus, and immunosuppressive treatment in renal transplant patients with HCV infection. Forty-five of 378 kidney recipients (January 1973-September 1993) had anti-HCV antibodies (prevalence = 11.9%) detected by second generation ELISA (Abbott Pasteur). Viral RNA was detected in those patients by RT-PCR in serum and liver. HCV-positive patients underwent liver biopsy to assess their liver tissue lesions according to Knodell's score. Patients were also screened for Hbs, Hbc and Hbe antigens (ELISA, Abbott) and cryoglobulins (immunobinding, SEBIA). Of the 45 HCV+ patients, 38 (84.4%) had persistent viral replication in the serum and 29 of the 30 patients having undergone liver biopsy had PCR-positive liver tissue. The liver biopsies revealed no active hepatitis lesion in 14 patients (46.6%, Group CAH-), 16 (53.3%) had chronic active hepatitis (Group CAH+) and 3 (10%) had signs of cirrhosis. Comparing groups CH+ and CH- showed that viral replication was detected in all 16 patients with chronic active hepatitis, versus 10/14 patients in the CAH- group (P < 0.05). Patients were more frequently treated with azathioprine in the CH+ group (12/16 vs 8/14; P < 0.05). The duration of renal transplantation was significantly longer in patients with a Knodell score > 5 (58 +/- 56 months vs 35 +/- 29 months, P < 0.001). Incidence of co-infection with HBV was similar in both groups. The mean values of alanine aminotransferase correlated with the Knodell score (r = 0.4, P = 0.03). Mixed cryoglobulinaemia was more common in the replicant forms of HVC infection (12/38 vs 1/7, P < 0.0001). This study shows that liver histological lesions are correlated with HCV viral replication, are more frequent in patients treated with azathioprine and are more severe as the duration of transplant is longer.

Alanine Transaminase

Use of cryomicrotomy to study gastric diffusion of amoxicillin in guinea pigs.

Cryomicrotomy has been used as a new technique for removing gastric mucosae from adult guinea pigs for the study of amoxicillin secretion across gastric mucosae. This method allowed a very regular thickness of the removed surface layer of mucosa to be obtained with good reproducibility. Gastric superficial mucosa concentrations and gastric juice concentrations of amoxicillin were determined 1, 2, and 4 h after intramuscular administration (50 mg/kg) in 21 guinea pigs by a microbiological method. No antibiotic was detected in gastric samples at 4 h, except for a low-level mucosal concentration in one animal, thus indicating the short time that amoxicillin is present in gastric samples.

Amoxicillin

Determination of amplification level of the c-erbB-2 proto-oncogene in human breast carcinomas: a comparative study between non-radioactive and radioactive labelling.

A quantitative method of polymerase chain reaction (PCR) using both digoxigenin and radioactive labelled probes has been used for the detection of the c-erbB-2 proto-oncogene amplification in breast carcinomas with formalin-fixed paraffin-embedded tissue sections. c-erbB-2 proto-oncogene amplification has been demonstrated in 14 infiltrating ductal carcinomas. The technique consisted of the co-amplification of c-erbB-2 and IFN-gamma (interferon-gamma) genes. The latter was considered as a single copy gene per genome-equivalent. The aim of this study was to compare two quantitative PCR techniques based on the incorporation of either digoxigenin-11-dUTP or 32P-dCTP, during amplification. For the colorigenic method, using the Dig system, after electrophoresis and transfer, the specific bands were revealed with a chromogenic substrate of phosphatase. Their intensity estimated by scanning photometry following blot transparisation. After electrophoresis, the radioactive gel was submitted to radioautography and the band intensities evaluated by scanning spectrophotometry. For the 14 samples, a good agreement between both methods was noted. The colorigenic method is a valuable alternative to radiolabelling due to: i) time saving, ii) reagent conservation, iii) safe manipulation and iv) sensitivity of the same order for both methods.

Base Sequence

[Electron microscopic studies of the action of erythromycin, doxycycline and ofloxacin on the growth cycle of Chlamydia trachomatis].

The aim of this work is to realise an ultra structural study of the action of antibiotics (doxycycline, erythromycin and ofloxacin) on the intracellular growth cycle of chlamydia. All assays were done on McCoy cells. Antibiotics were added to the culture medium two hours after inoculation with C. trachomatis. 24 and 48 hours, cells were removed and treated by standard procedure for transmission electron microscopy. No difference between control-cells and cells treated with doxycycline, erythromycin (0.015 mg/l) and ofloxacin (0.15 mg/l), was observed in the inclusions (number and size). However 48 hours, the quantity of elementary bodies (E.B.) was lower in treated culture. The organisms were not morphologically different from those seen in untreated culture. At higher concentrations of doxycycline and erythromycin (0.03 mg/l - 0.06 mg/l), the inclusions were smaller. Reticulate bodies (RB) were each in separate inclusion indicating that no fission has taken place. At 48 hours, no infectious forms (EB) were observed. Small or large RBs appeared with an apparent normal cytoplasmic membrane within an inflated cell wall. With ofloxacin (0.3 - 0.6 mg/l), inclusions contained enlarged and sometimes empty bacterial cells. Doxycycline and erythromycin (0.03 mg/l) inhibit the division of RBs and there maturation to EBs Ofloxacin (0.3 mg/l) induces the production of large abnormal forms which may not be able to revert towards viable bacteria.

Cell Division

[Multicenter study of the in vitro sensitivity of genital mycoplasmas to antibiotics].

The in vitro susceptibility of Ureaplasma urealyticum (Uu) and Mycoplasma hominis (Mh) was evaluated in a multicentric study performed in seven hospitals from different geographic areas in France. During a three month period, 324 Uu and 72 Mh clinical isolates were tested using a system ready for use, SIR Mycoplasma (Sanofi Diagnostics Pasteur). For Uu, the percentage of strains intermediate (I) or resistant (R) was as follows: doxycycline (3), minocycline (2.5), lymecycline (6.7), erythromycin (72, most I), josamycin (0.9), clindamycin (88), pristinamycin (0.3), ofloxacin (34, most I). For Mh, the percentage of strains I or R was respectively: doxycycline (2.7), minocycline (5.5), lymecycline (15.2), erythromycin (100), clindamycin (1.4), ofloxacin (2.7), josamycin (0) and pristinamycin (0). Comparable results were observed in the different geographic areas. The frequency of acquired resistances does not justify modifications in the usual treatment of genital mycoplasma infections but leads to monitor their susceptibility to antibiotics.

Clindamycin

Multiresistant corynebacteria in bacteriuria: a comparative study of the role of Corynebacterium group D2 and Corynebacterium jeikeium.

During an 11-month prospective study, urine cultures were performed on 5685 samples obtained in three hospital units. The use of a selective medium improved the recovery of antibiotic-multiresistant corynebacteria (AMC): 703 isolates (12.4%) compared with 88 isolates (1.6%) on sheep blood agar. Corynebacterium group D2 (CGD2) was isolated in 80.5% of urines yielding greater than or equal to 10(5) AMC ml-1 whereas Corynebacterium jeikeium represented 80.2% of isolates with less than 10(5) AMC ml-1. Among 16 patients with greater than or equal to 10(5) ml-1 C. jeikeium none had signs of urinary tract infection. In contrast, among 56 patients with greater than or equal to 10(5) CGD2, 40 (71%) had abnormal urinary sediment (mainly apatite or struvite crystals) and 29 (52%) had clinical signs of urinary tract infections sometimes complicated by lithiasis (seven cases) and alkaline-encrusted cystitis (two cases).

Anti-Infective Agents, Urinary

Thiosulfate, polythionates and elemental sulfur assimilation and reduction in the bacterial world.

Among sulfur compounds, thiosulfate and polythionates are present at least transiently in many environments. These compounds have a similar chemical structure and their metabolism appears closely related. They are commonly used as energy sources for photoautotrophic or chemolithotrophic microorganisms, but their assimilation has been seldom studied and their importance in bacterial physiology is not well understood. Almost all bacterial strains are able to cleave these compounds since they possess thiosulfate sulfur transferase, thiosulfate reductase or S-sulfocysteine synthase activities. However, the role of these enzymes in the assimilation of thiosulfate or polythionates has not always been clearly established. Elemental sulfur is, on the contrary, very common in the environment. It is an energy source for sulfur-reducing eubacteria and archaebacteria and many sulfur-oxidizing archaebacteria. A phenomenon still not well understood is the 'excessive assimilatory sulfur metabolism' as observed in methanogens which perform a sulfur reduction which exceeds their anabolic needs without any apparent benefit. In heterotrophs, assimilation of elemental sulfur is seldom described and it is uncertain whether this process actually has a physiological significance. Thus, reduction of thiosulfate and elemental sulfur is a common but incompletely understood feature among bacteria. These activities could give bacteria a selective advantage, but further investigations are needed to clarify this possibility. Presence of thiosulfate, polythionates and sulfur reductase activities does not imply obligatorily that these activities play a role in thiosulfate, polythionates or sulfur assimilation as these compounds could be merely intermediates in bacterial metabolism. The possibility also exists that the assimilation of these sulfur compounds is just a side effect of an enzymatic activity with a completely different function. As long as these questions remain unanswered, our understanding of sulfur and thiosulfate metabolism will remain incomplete.

Archaea

Value of a novel antibiotic association for the study of sperm motility in vitro.

An association of mezlocillin and amikacin was compared to the commonly used penicillin and streptomycin for ridding of bacterial flora in 31 contaminated semen, when sperm motility after 24 hour incubation was checked. The former association proved efficient in 30 cases and the latter in only 19. Thus the mezlocillin/amikacin association might be of interest when semen is manipulated.

Amikacin

Characterization of the major iron-regulated protein of Neisseria gonorrhoeae and Neisseria meningitidis.

The major iron-regulated protein (MIRP) was purified, from both Neisseria gonorrhoeae and N. meningitidis by selective extraction with cetyltrimethylammonium bromide followed by ion-exchange and moleculair-seive chromatography. Solutions of the purified proteins had a characteristic pink color. The overall amino acid composition of these proteins was similar, although differences were noted in the number of serine, threonine, and lysine residues. Nevertheless, the N-terminal amino acid sequence was identical through 47 residues for both the meningococcal and gonococcal MIRP. Plasma emission spectrophotometry revealed that the meningococcal 37K protein contained ca. 1 mole Fe/mole protein.

Amino Acid Sequence

[Confusional form of Chlamydia psittaci encephalitis. Diagnostic value of microimmunofluorescence. A case].

A rare case of Chlamydia psittaci encephalitis is reported. The disease started with anxiety, agitation and fever (38.5 degrees C) accompanied with hallucinations and regressed within 48 hours, but a confusional syndrome persisted for 9 days. Alterations in the blood-brain barrier with low CSF protein levels and signs of lateralization could be demonstrated. The inflammatory syndrome remained discrete. The cause of the disease was disclosed by serology and epidemiological investigations. The spontaneous outcome was favourable, thus confirming that neurological forms of psittacosis are benign. This case shows that microimmunofluorescence is more sensitive than the complement fixation test and that significant levels of antibodies directed against Chlamydia psittaci may persist for almost one year in the absence of treatment.

Adult

[Branhamella catarrhalis in infectious pathology of the respiratory tract].

Branhamella catarrhalis has long been considered as a commensal of the upper respiratory tract. However, since 1972 several studies have shown that it can be responsible for respiratory tract infections. By isolating this micro-organism in sputum or nasal smear of 44 hospital patients we were able to confirm this finding, while delineating some of the clinical features of the infections observed. In all 44 patients these were mild infections, yet treatment appeared to be necessary in view of the risk of severe infection (B. catarrhalis septicaemia) in subjects with poor general condition. The germ is usually sensitive to antibiotics other than beta-lactam antibiotics (58% of the strains isolated were found to produce a beta-lactamase).

Adult