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J Duval

Publications and source records attributed to J Duval.

At least 145 records · Page 8Linked to original sources
PubMed1984

Binding of estradiol and 5 alpha-androstane-3 beta-17 beta-diol by the male rat enriched gonadotrope cells.

Dispersed pituitary cells from 42-day old male rats were separated using centrifugal elutriation. Based on LH and PRL cellular contents, fractionated cells were pooled into two fractions: "Lactotrope++ population" and "gonadotrope++ population". Estradiol and 5 alpha-androstane-3 beta, 17 beta-diol binding was measured in these fractions. Results revealed that: (1) The steroid receptors are not destroyed by cell dispersion and elutriation. (2) The estradiol receptor content is higher in gonadotrope++ cells than in lactotrope++ cells. (3) The number of binding sites for the two steroids changes in the different fractions: whereas it is exactly similar in "lactotrope++ population", it is much higher for estradiol than for 5 alpha-androstane-3 beta, 17 beta-diol in "gonadotrope++ population". These results suggest two different species--or conformations--of receptor binding sites for estradiol in the male rat pituitary; the first one could link both steroids, the second one would be specific for estradiol.

Androstane-3,17-diol↗
PubMed1984

[Comparison of bacteriological and immunoenzyme methods for the serum determination of sisomicin. Pharmacokinetic application in the human].

A modification of the serum gentamicin immunoenzymatic method (Syva- Biom erieux kit) for sisomicin assay is proposed and compared to the bacteriological reference method. It shows a higher sensitivity (0.1 mg.l-1) with a shortened time of analysis (less than 1 hour) and a good reproducibility (range: 4.7% to 1.6% for concentrations between 0.5 mg.l-1 and 10 mg.l-1) but the concentrations are 15 p. cent lower as compared to the bacteriological method. A pharmacokinetic study, performed in five patients, enables us to demonstrate the praticability of this method for the adaptation of the dosage regimen in renal insufficiency.

Biological Assay↗
PubMed1984

[Antibacterial activity of lamoxactam in combination with penicillin, ampicillin and amoxicillin against clinical strains of Enterococci, group B Streptococci and Listeria].

The antibacterial activity of moxalactam-penicillin combinations was studied against clinical isolates of Enterococci (20 strains), group B Streptococci (10), Listeria (3) and Enterobacteriaceae (10), using a microtiter checkerboard (FIC index, FBC index). Combinations of moxalactam (MX) with penicillin G, ampicillin or amoxicillin were usually synergistic against Enterococci and Listeria but with high MX concentrations. Against group B Streptococci, penicillin-MX combinations were synergistic (40%) or additive (60%) with MX concentrations easily achievable in the CSF.

Amoxicillin↗
PubMed1984

[Effect of the amoxicillin-gentamicin combination in the presence of clavulanic acid on 8 strains of amoxicillin-resistant bacteria].

The in vitro inhibitory activity of a combination of amoxicillin and gentamicin was assayed by the microdilution technique in liquid medium on 8 amoxicillin-resistant strains, with the addition of clavulanic acid at a concentration of 4 micrograms/ml. A synergistic effect was demonstrated when clavulanic acid was added. The FIC index was particularly low for the 2 Staphylococcus aureus strains tested (0.19 and 0.25), and slightly higher for the 2 Escherichia coli (0.25 and 0.5) and 2 Proteus vulgaris (0.5 and 0.5) strains. Synergism was less apparent for the 2 Klebsiella pneumoniae strains tested (0.63 and 0.75). Without clavulanic acid, a synergistic effect was found on only three strains: one Staphylococcus aureus, one Klebsiella and one Proteus. However, the high levels of MICs at which these effects were observed preclude the clinical usefulness of the association. We conclude that the synergistic effect of the amoxicillin-gentamicin combination on susceptible strains is confirmed on amoxicillin-resistant strains when clavulanic acid is added.

Amoxicillin↗
PubMed1984

[Antibiotic sensitivity test. Comparative multicenter study of the gel diffusion and ATB methods].

The ATB method is a new method for antibiotic susceptibility testing. In a collaborative study, it was compared to a standard disc diffusion method. 23 strains were tested to determine reproducibility and 969 strains were used in the comparative study. Reproducibility of both methods is equivalent; differences due to strains were observed. Agreement between both methods is 87,9%, minor discrepancies are 8,7% and major discrepancies are 3,3%. Significant differences were found for carbenicillin and cefalotin and confirmed by MIC determination using the agar dilution method. Overall results show that the ATB method is reliable and comparable to disc diffusion for routine susceptibility testing.

Automation↗
PubMed1984

[In vitro activity of the amoxicillin-clavulanic acid combination on anaerobic bacteria. Comparison with amoxicillin, lamoxactam and metronidazole].

Minimal inhibitory concentrations (MIC) of the combination amoxicillin + clavulanic acid (AAC) (2/1 w/w) on 84 strains of obligate anaerobes were measured by the agar diffusion method and compared to those of amoxicillin (AMO), lamoxactam (LAM) and metronidazole (MET). For the 47 Bacteroides fragilis strains tested, the mode MIC was 0.5 microgram/ml with AAC, 1-2 with MET, 0.5-1 with LAM and 8-16 with AMO. A similar range of activity was found on the 16 other strains of Bacteroides sp.. AAC and AMO have a comparable activity on Clostridium perfringens (mode MIC 0.016-0.032 microgram/ml), superior to that of LAM (mode MIC 0.125) and MET (mode MIC 0.5). AAC and AMO have an almost identical activity on Peptococci and Peptostreptococci, the MIC for both drugs being less than 0.125 microgram/ml. A similar activity was found for LAM and MET.

Amoxicillin↗
PubMed1984

[Multicenter study in actual situations of the activity of an antiseptic in the surgical washing of hands].

Results of a collaborative study carried out in three different hospitals by nine surgeons are reported. Activity of a new scrub applied according to a standardized protocol was compared with that of the different scrubs and/or antiseptics customarily used by participating surgeons with their habitual method. Activity of products was evaluated by bacterial counts in gloves. Statistical analysis of results demonstrates the value of this trial design which compares scrubs under real conditions of use.

Anti-Infective Agents, Local↗
PubMed1984

[Multicenter study of the antibacterial activity of a new cephalosporin: CM 40874].

Minimal inhibitory concentrations (MIC) of CM were evaluated on 2 548 bacterial strains isolated in 8 hospitals. CM demonstrated high activity on Enterobacteriaceae, the MIC being less than or equal to 0.125 micrograms/ml for 71% of the 1 362 strains tested, less than or equal to 1 for 99.6%, and less than or equal to 4 for 99.9%. Mode MIC varies little among the different groups of Enterobacteriaceae (from 0.06 to 0.12 micrograms/ml), with the exception of Serratia sp. (mode MIC : 0.25) and Klebsiella oxytoca (mode MIC : 0.03). Most of Enterobacter, Serratia, and Citrobacter sp. strains not inhibited by cefotaxime are readily inhibited by CM at the same concentrations than susceptible strains. CM has less activity on P. aeruginosa (MIC 2-32 micrograms/ml) and Acinetobacter sp. (MIC 8-128). Staphylococci (MIC 32) and Enterococci are not susceptible. Variable activity is found against other Streptococci. CM inhibits Haemophilus sp. at MICs of 0.12 to 0.5 micrograms/ml and Gonococci at MICs of 0.03 to 0.5 (whether the strains produce beta-lactamase or not). Meningococci have a mode MIC of 0.03 micrograms/ml (range 0.008 to 0.25). Thus, CM 40874 is a new third generation cephalosporin with high activity on Enterobacteriaceae, including those strains not susceptible to cefotaxime and good activity on Haemophilus sp. and Neisseria sp. This additional activity is probably supported by enhanced resistance to enzymatic inactivation by beta-lactamases.

Bacteria↗
PubMed1984

Productivity management: a model for participative management in health care organizations.

The current cost of inflation in the health care industry, contributed to in part by the Medicare and Medicaid legislation, has created concerns for productivity that can no longer be ignored by health care administrators. Despite these concerns and in the face of increasingly scarce resources, many hospitals have not yet established productivity tracking systems or methods for measuring and analyzing potential areas for productivity improvement.

California↗
PubMed1983

[In vitro action of moxalactam on hospital bacteria. Results of a multicenter survey].

The high potency of Moxalactam on three major groups of bacteria, i.e. Enterobacteriae, Haemophilus and Bacteroïdes, predicted by previous studies, has been confirmed by the study of hospital strains in this multicenter investigation. Among these groups, the proportion of resistant strains is very low. However, Moxalactam is not superior to older agents on staphylococci, Streptococci and Listeria, and is less active than certain new agents on Pseudomonas. Moxalactam is one of the best "third generation" cephalosporins. It is remarkable by its potency against Bacteroides fragilis and its weak activity on Streptococci and Pneumococci. The unanswered question concerns the future of resistant strains: will they remain exceptional or will they multiply?

Bacteria↗
PubMed1983

Early increases in RNA polymerase I activity and 18S and 28S rRNA synthesis in the male rat pituitary after oestradiol treatment.

This article reports the effect of a single injection of 17 beta-oestradiol on RNA synthesis, in the male rat pituitary. An increase in RNA polymerase I activity, with a maximum effect between 10 and 15 hours, is described. No modification in RNA polymerase II activity was detected. These results were extended and confirmed, using in vitro double labelling of RNA, following in vivo oestrogen treatment. Polyacrylamide gel electrophoresis of nuclear and cytoplasmic RNA showed an increased incorporation of adenine into 28S and 18S rRNA, in the pituitaries of oestrogen-treated animals. The 5S rRNA was not modified by the hormonal treatment. These effects on RNA polymerase I activity and on 28S and 18S rRNA synthesis were closely correlated with the long-term nuclear retention of receptor-oestradiol complexes, in vivo. Taken together, these observations argue in favor of the nucleolus as a preferential target for receptor-bound oestradiol, in the cell nucleus of the male rat pituitary.

Animals↗
PubMed1983

[Calcium, modulator of the expression of gonadoliberin at the intracellular level].

GnRH has been entrapped in liposomes. Chromatographic studies and enzymatic peptidase treatments, show the efficiency of the encapsulation. A purification method on G75 Sephadex of the entrapped GnRH is described. This method prevents any dilution of the liposome fraction. A free GnRH contamination, lower than 0.4 per cent, has been observed. Superfused hypophyses respond to the message of the internalized GnRH only when calcium is present in the extracellular medium. The intensity of the answer depends on the duration of the entrapped GnRH infusion. The decrease observed in the response intensity after a long stay of the GnRH in the cytoplasm allows us to say that GnRH controls its own expression: The binding of GnRH to the membrane receptor during the early phase induces a calcium uptake necessary to the expression of the internalized GnRH, this being the late phase in LH release. A too low calcium concentration does not allow GnRH expression. As a consequence, GnRH is enzymatically degradated by the cytoplasmic peptidases. The LH release during the late phase is the result of a combined action of calcium and cytoplasmic peptidases. To support this idea we show: 1- that an extracellular calcium concentration around 0.5 or 0.6 mM is the best condition for the expression of the internalized GnRH. 2- that a GnRH agonist (D-Ala6-GnRH) known to be peptidase resistent induces a higher LH release in our experimental conditions.

Animals↗
PubMed1983

[Relation between cyclic AMP and phagocytosis in human monocytes].

The involvement of cyclic adenosine 3'-5' monophosphate (cAMP) in the regulation of human monocyte phagocytosis of staphylococcus aureus in vitro was demonstrated by assay of adenylate cyclase (AC) and cAMP phosphodiesterase (PDE). Phagocytosis was associated with diminished AC activity (p less than 0,05) and concurrently increased PDE activity (p less than 0,005). Transmission electron microscopy provided evidence that these changes coincide with peak phagocytic activity occuring 10-20 minutes after the start of phagocytosis.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1983

[In vitro activity of cefatiolene (RP 42,980) against hospital bacteria. Comparison with cefotaxime and lamoxactam. Results of a multicenter study].

This work reports a multicenter study of antibacterial activity of cefatiolene (RP 42 980), a new third generation cephalosporin, in comparison with cefotaxime and lamoxactam. On the basis of MIC, activity of the three products is similar or Gram negative rods, but cefotaxime is a little more active on Enterobacteriaceae. The activity against Staphylococci requires further studies, indeed the determination of IC 50 of some strains showed a better activity of cefatiolene, but this was not observed by determination of MIC. As cefotaxime and contrary to lamoxactam, cefatiolene is active at low concentrations on other Streptococci than Enterococci, but a little on Bacteroides.

Bacteria↗
PubMed1983

[In vitro study of combinations between third-generation cephalosporins and aminoglycosides on Enterobacteriaceae].

Four cephalosporins (cefotaxime, moxalactam, cefoperazone and ceftriaxone) were tested in combination with four aminoglycosides (gentamicin, tobramycin, netilmicin and amikacin). We examined 16 clinically isolates of Enterobacteriaceae of which 8 were resistant to newer cephalosporins. The synergy studies was evaluated with a microtiter checkerboard broth dilution. Studies of synergy revealed that cephalosporins in combination with amikacin were often synergistic against third generation cephalosporins resistant strains. These results suggest that amikacin may be facilitate the cephalosporin antibacterial activity.

Aminoglycosides↗
PubMed1983

[In vitro activity of azthreonam on hospital Gram-negative bacilli. Results of a multicenter study].

This work reports a multicenter study of antibacterial activity of azthreonam, a new antibacterial agent of the monobactam group, on Gram negative rods. Enterobacteriaceae are very sensitive to azthreonam (modal MIC: 0,06 micrograms/ml); some strains have higher MIC greater than or equal to 8 micrograms/ml, particularly among Enterobacter, Serratia and Citrobacter. Azthreonam has a good activity on Pseudomonas aeruginosa: 90% of the strains are inhibited by 8 micrograms/ml or less. Acinetobacter are less sensitive with a modal MIC of 32 micrograms/ml. Haemophilus are inhibited by low concentrations, 0,06 to 0,12 micrograms/ml usually.

Anti-Bacterial Agents↗
PubMed1983

[Multicenter study of the in vitro antibacterial activity of ceftazidime on gram-negative bacilli].

This work reports a multicenter study of antibacterial activity of ceftazidime, a new third generation cephalosporin, on hospital Gram negative rods. Enterobacteriaceae are very sensitive to ceftazidime with a maximum number of strains inhibited by 1 microgram/ml or less (modal MIC 0, 125 microgram/ml); some resistant strains are observed, particularly among Enterobacter and Citrobacter. Activity of ceftazidime on Pseudomonas aeruginosa is superior to other third generation cephalosporins; modal MIC is 1 microgram/ml and 88% of the strains are inhibited by 4 microgram/ml or less. Acinetobacter are less sensitive to ceftazidime, with a modal MIC of 8 microgram/ml.

Bacteria↗