PubMed Health⌕ Search

Biomedical subjects

J Duval

Publications and source records attributed to J Duval.

At least 55 records · Page 3Linked to original sources
PubMed1995

Influence of hepatitis C virus (HCV) genotypes on HCV recombinant immunoblot assay patterns.

Ninety-six patients with chronic hepatitis C were studied. A second-generation recombinant immunoblot assay detected anti-NS4 antibodies significantly more often in patients infected by hepatitis C virus genotype 1 than in patients infected by other types. By a third-generation recombinant immunoblot assay, the prevalences of the four antibodies measured did not differ according to the hepatitis C virus genotype.

Antigens, Viral↗
PubMed1995

Early detection of secretogranin-II (SgII) in the human fetal pituitary: immunocytochemical study using an antiserum raised against a human recombinant SgII.

Secretogranin-II (SgII) is a protein contained within secretory granules of mainly gonadotrophs. The purpose of this study was to determine whether SgII immunoreactivity (SgII-IR) in the human fetal pituitary was temporally related to gonadotropin immunoreactivity. A specific antihuman SgII antiserum was thus required. A complementary DNA clone with an open reading frame for human (h) SgII was synthesized by reverse transcription-polymerase chain reaction from pituitary total RNA. This clone was used to obtain the SgII polypeptide (-9 to 152) as a fusion protein, in a heterologous expression prokaryotic system. Antisera against the fusion protein were raised in rabbits and checked for specificity and sensitivity through Western blotting. Human fetal pituitaries from week 6 of gestation onward were used for immunocytochemical studies. Consecutive semithin sections were treated with the specific antisera against hSgII, beta-endorphin, and hPRL and with monoclonal antibodies to hCG alpha, hLH, and hFSH. SgII immunoreactivity appeared at week 8 and was restricted to pituitary cells expressing beta-endorphin (100% colocalization). At week 9, FSH-positive cells did not contain SgII. From week 10, gonadotrophs progressively exhibited SgII-IR, up to 50% of that in FSH-containing cells at week 26. The granin was never found in PRL cells whatever the stage of development. The present data demonstrate that SgII-IR is detected very early in fetal life; however, the positive cells are not gonadotrophs, but corticotrophs. Within gonadotrophs, SgII appears subsequent to hormones. At birth, more than 90% of SgII-IR cells are represented by corticotrophs and gonadotrophs.

Adrenal Glands↗
PubMed1995

[Bactericidal activity of combinations of ticarcillin-clavulanic acid or other beta-lactams (amoxicillin, piperacillin-tazobactam, ticarcillin) with gentamicin against Enterococcus faecalis and E. faecium].

MICs of amoxicillin, piperacillin-tazobactam, ticarcillin and ticarcillin-clavulanic acid were determined against 52 clinical strains of E. faecalis and E. faecium. Modal MICs (mg/l) of these antibiotics were 1, 4, 64 and 64, respectively. Bactericidal activity of the beta-lactams was tested at two concentrations (1/2 MIC and 100 mg/l) alone or combined with gentamicin (4 mg/l) against 10 clinical strains of Enterococcus spp. Activity of ticarcillin was not modified by the addition of clavulanic acid (4 mg/l). Time-kill curves showed that all beta-lactams at 100 mg/l were bactericidal after 18 h of incubation (decrease in bacterial counts > or = 3 log10 CFU/ml) against 6 strains of E. faecalis, with MICs of amoxicillin at 1 mg/l and 2 strains of E. faecium with MICs of amoxicillin at 1 and 2 mg/l. Addition of gentamicin resulted in a bactericidal effect at 3 or 6 hours for the great majority of the combinations studied, except against the two strains highly resistant to gentamicin. Combination of every beta-lactam at 1/2 MIC with gentamicin was synergistic (except in case of high level resistance to gentamicin) and prevented bacterial growth but was not bactericidal. Against two strains of E. faecium with high MICs of amoxicillin (8 mg/l), piperacillin-tazobactam (64 mg/l) and ticarcillin-clavulanic acid (512 mg/l), only combinations of amoxicillin 100 mg/l and gentamicin were always bactericidal. In conclusion, against E. faecalis strains, ticarcillin-clavulanic acid tested at 100 micrograms/ml had a bactericidal activity similar to that of the other beta-lactams tested, alone or combined with gentamicin.(ABSTRACT TRUNCATED AT 250 WORDS)

Amoxicillin↗
PubMed1994

Construction of a gyrA plasmid for genetic characterization of fluoroquinolone-resistant Staphylococcus aureus.

We have constructed a gyrA trans-complementation plasmid, pAT512, by cloning the wild-type gyrA gene of Staphylococcus aureus into the expression vector pAT392. Introduction by electrotransformation of pAT512 into a high-level fluoroquinolone resistant mutant of S. aureus (ciprofloxacin MIC = 16 micrograms ml-1) having a gyrA mutation which results in a Ser-84 to Leu substitution, reduced the MICs of norfloxacin and ciprofloxacin for the host of four- and eight-fold, respectively.

Anti-Infective Agents↗
PubMed1994

In vivo activities and penetration of the two components of the streptogramin RP 59500 in cardiac vegetations of experimental endocarditis.

We evaluated the in vivo activity and the diffusion of radiolabelled RP 57669 (RPI) and RP 54476 (RPII), the two components of the injectable streptogramin RP 59500, alone or in combination, in aortic vegetations from experimental endocarditis in rabbits. RPI and RPII demonstrated in vitro bacteriostatic and bactericidal synergy against a clinical strain of Staphylococcus aureus resistant to methicillin and susceptible to erythromycin. In experimental staphylococcal endocarditis, RP 59500 was as effective as vancomycin and significantly more effective than RPI (P < 0.01) and RPII (P < 0.05). Autoradiography studies showed different patterns of distribution into cardiac vegetations infected with Streptococcus sanguis for [14C]RPI and [14C]RPII. [14C]RPI was homogeneously distributed throughout the vegetations whereas [14C]RPII showed a decreasing gradient of concentration between the periphery and the core of the vegetation, with an approximately 2:1 ratio. [14C]RPI diffused approximately 2 to 4 times more than [14C]RPII into the core of the vegetations. Since the injected ratio of RPI and RPII is 30:70 in RP 59500, the actual RPI:RPII ratio in the core of the vegetation may range from 0.8 to 1.7, a ratio which remains compatible with the in vivo synergism demonstrated between the two components.

Animals↗
PubMed1994

In vivo selection during pefloxacin therapy of a mutant of Staphylococcus aureus with two mechanisms of fluoroquinolone resistance.

Staphylococcus aureus BM4626 (ciprofloxacin MIC, 0.5 microgram/ml) and BM4627 (ciprofloxacin MIC, 32 microgram/ml) were isolated from the same patient before and during pefloxcin therapy for septic tibial nonunion, respectively. The two strains had similar serotypes and indistinguishable phage types and SmaI-generated restriction fragment length polymorphisms. Portions of the gyrA (codons 60 to 120) and the gyrB (codons 420 to 480) genes of each clinical isolate were amplified by PCR and sequenced. Strain BM4627 had a serine-to-leucine substitution resulting from a cytosine-to-thymidine mutation at codon 84 of gyrA relative to the sequence of the gyrA gene of BM4626. Norfloxacin accumulation, measured in a whole-cell uptake assay, was significantly lower in BM4627 than BM4626. These data indicate that double mutants can be selected in vivo under fluoroquinolone therapy.

Anti-Infective Agents↗
PubMed1994

Characterization of a hospital outbreak of imipenem-resistant Acinetobacter baumannii by phenotypic and genotypic typing methods.

During a 13-month period, 31 patients hospitalized primarily in two intensive care units (ICUs) were either colonized or infected by imipenem-resistant Acinetobacter baumannii. Typing of the isolates by three methods (antibiotyping, biotyping, and pulsed-field gel electrophoresis) revealed that two distinct strains were involved in the first 9 cases of the outbreak and that one of these strains, which had acquired a higher level of imipenem resistance as well as resistance to all aminoglycosides, accounted for 21 of 22 cases in the second part of the outbreak. ICU environmental contamination was recognized as an important reservoir of this epidemic strain. The outbreak ceased only after the ICUs were closed for complete cleaning and disinfection.

Acinetobacter↗
PubMed1994

Significance of highly positive c22-3 "indeterminate" second-generation hepatitis C virus (HCV) recombinant immunoblot assay (RIBA) and resolution by third-generation HCV RIBA.

Second-generation recombinant immunoblot assay (RIBA) is widely used for the validation of anti-hepatitis C virus (HCV) antibody detection. The aims of this work were (i) to determine, in terms of liver disease and HCV replication, the significance of a peculiar "indeterminate" second-generation RIBA pattern characterized by the presence of high titers of antibodies directed to c22-3, a protein bearing core epitopes and (ii) to determine whether a more advanced version of the same strip assay, namely a third-generation RIBA, may solve the problem of such indeterminate patterns. Sixty patients for which c22-3 indeterminate second-generation RIBAs were highly positive were studied. Forty-two of them (70%) were immunocompromised. Serum transaminases were increased in 46 cases (77%), and HCV RNA was detected by PCR in 50 cases (83%). Third-generation RIBA remained highly positive c22 indeterminate for 9 patients (15%) but was positive for 51 (85%), mostly because of increased sensitivity for the detection of both anti-c100 and anti-c33c antibodies. These results suggest that third-generation RIBA may achieve resolution of most of these cases but that highly positive c22 indeterminate third-generation RIBA may persist when used with some patients with very low titers of anti-HCV nonstructural protein antibodies.

Adolescent↗
PubMed1994

[In vitro antibacterial activity of cefpirome: a new cephalosporin; results of a multicenter study].

The in vitro activity of cefpirome, a new injectable cephalosporin was studied against 1,082 clinical isolates in a multicentre study. Minimum inhibitory concentrations were determined using an agar dilution method. Cefpirome was active against Enterobacteriaceae. On naturally non-producing beta-lactamase species, cefpirome was active on most of the strains with MICs < or = 0.5 mg/l, including strains producing an acquired penicillinase: E. coli 0.03-0.06, P. mirabilis 0.06-0.12, Salmonella spp. 0.06-0.06, Shigella spp. 0.016-0.03. MICs of K. pneumoniae (0.06-4) ranged from 0.016 to 32:MICs were high against expanded-spectrum betalactamase producers strains. Against species producing cephalosporinase, cefpirome was also active on most of the strains with MICs < or = 0.5: E. cloacae 0.06-2, Citrobacter spp. 0.03-1, S. marcescens 0.06-0.5, P. indol + 0.06-0.25, P. stuartii 0.12-0.5. Cefpirome was less active on Pseudomonas aeruginosa, (8-32) and on A. baumanii (16-32). MICs of cefpirome were low against Haemophilus spp. betalactamase producing or not (0.01-0.03) and M. catarrhalis (0.6-4). Activity of cefpirome on methicillin-sensitive staphylococci, was higher than other third generation cephalosporins (0.25-2) comparable to that of cephalotin and cefamandol. Methicillin-resistant strains should be considered as resistant. Pneumococci (0.01-0.03), except for penicillin-R strains, and streptococci A, B, C, G (0.01-0.06) were very susceptible. Enterococci were of low sensitivity or resistant. Among anaerobes, C. perfringens appeared often susceptible, and Bacteroides spp. resistant.

Cephalosporins↗
PubMed1994

Immunological disorders in C virus chronic active hepatitis: a prospective case-control study.

Hepatitis C virus-related chronic hepatitis may be associated with various immunological disorders. The aim of this study was to determine prospectively the prevalence of the clinical, biochemical and pathological immunological abnormalities in a series of 61 consecutive patients with chronic hepatitis C, compared with those in 61 age- and sex-matched control subjects without markers of hepatitis C virus and hepatitis B virus infections and with those in 61 patients with chronic hepatitis B. The following investigations were systematically performed before any treatment: detection of serum cryoglobulinemia and rheumatoid factor, detection of a large variety of serum anti-tissue antibodies, biopsy of labial salivary glands, ophthalmological examination, dosage of thyroid-stimulating hormone and in vivo capillary microscopy. Cryoglobulinemia was found in 36% of the hepatitis C virus patients, four of whom had dermatological and/or neurological manifestations of vasculitis, and rheumatoid factor was present in 70%. Serum anti-tissue antibodies were detected in 41% of cases, mostly antinuclear and anti-smooth muscle antibodies. Liver-kidney microsomal and antithyroid antibodies were rare. Salivary gland lesions were found in 49% of the patients: all had lymphocytic capillaritis, sometimes associated with lymphocytic sialadenitis resembling that of Sjögren's syndrome, but without features of sicca syndrome and Ro/SSA antibodies. Five percent of the patients had lichen planus. The prevalences of cryoglobulinemia, rheumatoid factor and anti-tissue antibodies were significantly higher than those in the control group and patients with chronic hepatitis B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Lichen planus and hepatitis C virus--related chronic active hepatitis.

BACKGROUND AND DESIGN: An increased prevalence of chronic liver disease has been reported in patients with lichen planus (LP). We report six cases of LP associated with chronic active hepatitis and actively replicating hepatitis C virus (HCV). RESULTS: We studied six patients (three men and three women; mean age, 61 years; age range, 47 to 70 years) with various forms (cutaneous and/or mucosal) of LP and abnormal liver test results. Four patients had severe mucosal lesions. Cutaneous and mucosal lesions had a long-term evolution. Liver disease was discovered 2 to 6 years before LP in three cases and was diagnosed at the same time as LP in the three other cases. Liver biopsy performed in five patients showed chronic active hepatitis without cirrhosis in all five cases. Anti-HCV antibodies were detected in all cases by second-generation enzyme-linked immunosorbent assay and confirmed by second-generation recombinant immunoblot assay. Hepatitis C virus RNA was evidenced by means of polymerase chain reaction in the serum samples from the six patients, proving active viral replication. CONCLUSIONS: Lichen planus may be associated with HCV-related chronic active hepatitis. As interferon treatment may induce viral inactivation in some patients with HCV-related chronic liver disease, a search for HCV infection should be systematically performed in patients with chronic LP.

Aged↗
PubMed1993

In-vitro antibacterial activity of cefepime: a multicentre study.

The antimicrobial activity of cefepime, a new broad-spectrum parenteral cephalosporin, was evaluated in vitro against 1757 recent clinical Gram-positive and Gram-negative isolates. Cefepime was active at low concentrations (MIC50 values < or = 0.06 mg/L and MIC90 values < or = 0.12 mg/L) against non-cephalosporinase-producing Enterobacteriaceae (Escherichia coli, Proteus mirabilis, Salmonella spp. and Shigella spp.). For Klebsiella pneumoniae, MICs were between 0.016 and 16 mg/L; the highest MIC values were observed for extended-spectrum beta-lactamase-producing strains. Against Enterobacteriaceae, such as cephalosporinase producing Enterobacter cloacae, MICs were < or = 0.5 mg/L, but MICs against cephalosporinase hyperproducing strains were generally higher. Ticarcillin-sensitive strains of Pseudomonas aeruginosa were inhibited by cefepime concentrations of 0.5-16 mg/L, while cefepime MICs were 8-64 mg/L for strains resistant to ticarcillin. The cefepime MIC50 value for Haemophilus spp. including many resistant to amoxycillin, was 0.03 mg/L. Against methicillin-sensitive strains of Staphylococcus aureus, cefepime MICs were 0.5-16 mg/L; MICs against methicillin-resistant staphylococci were 16- > 128 mg/L). Against methicillin-sensitive coagulase-negative staphylococci, cefepime MIC values were 0.03-16 mg/L; corresponding values for methicillin-resistant strains were 2-128 mg/L. Streptococci (Groups A, C and G) were sensitive to cefepime with MICs ranging from < or = 0.008-2 mg/L (MIC50, 0.03 mg/L; MIC90, 0.25 mg/L). The activity of cefepime against Group B streptococci and pneumococci were comparable, with MIC50 values of 0.12 and 0.25 mg/L, respectively, and MIC90 values of 0.03 and 0.25 mg/L, respectively. Most enterococci and all Listeria monocytogenes strains had MICs > or = 32 mg/L.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗