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Biomedical subjects

C Benoit

Publications and source records attributed to C Benoit.

At least 19 recordsLinked to original sources
PubMed2006

Vasoreactivity of chorionic plate arteries in response to vasoconstrictors produced by preeclamptic placentas.

Inadequate blood flow and increased vasoconstriction of the placenta contribute to pregnancy associated disorders such as preeclampsia (PE). Because placental vessels lack autonomic innervation, humoral effects of the placenta must play critical roles in regulation of fetal-placental vascular contractility. In this study, we examined the nature of humoral factors produced by PE trophoblasts on placental vessel contractility using an organ bath perfusion model. Vasomotor responses were studied in vitro using placental chorionic plate arteries. Vessel rings from third branch chorionic plate arteries were dissected from human placentas following normal or PE delivery. The arterial rings were equilibrated in Krebs Henseleit buffer and exposed to placental conditioned medium, which was prepared by culture of villous tissue from PE placentas. Receptor antagonists for angiotensin II (ANG II), thromboxane (TX), and endothelin (ET) were used to determine which humoral factor produced by placental tissue (trophoblasts) was more effective in promoting vasoconstriction. The role of angiotensin converting enzyme (ACE) and non-ACE ANG II generating enzymes in regulation of placental vasomotor tone were also investigated. A total of 80 arterial rings from 48 placentas were studied. Our results showed: 1) enhanced vasomotor tone in arteries from PE placentas compared to those from normal placentas; 2) PE-CM induced vaso-constrictive activity could be partially attenuated by receptor antagonists for TX, ANG II and ET, respectively; and 3) chymostatin (a chymase inhibitor) produced a stronger inhibitory effect than captopril (ACE inhibitor) on PE conditioned medium induced vasoconstriction. Our data demonstrate increased vasocontractility in PE placentas and suggest that the non-ACE pathway is probably a major source of ANG II produced in the human placenta.

Arteries↗
PubMed2006

Development and preliminary experience with an ease of extractability rating system for prescription opioids.

One important factor in the abuse potential of an opioid product is the ease with which active drug can be extracted. There are currently no standards for testing or reporting extractability. This article describes the development of an Extractability Rating System for use by the pharmaceutical industry and regulators. Despite several limitations, this effort serves as a call for standardized testing and reporting so that products can be accurately rated, and should help establish goals for drug developers who wish to develop "abuse-resistant" opioid products.

Algorithms↗
PubMed2004

[Epidemiology and antimicrobial resistance of Streptococcus pneumoniae strains isolated in Ile de France area during 2001].

OBJECTIVE: The authors wanted to assess the level of Streptococcus pneumoniae antibiotic resistance in Ile de France. METHOD: In 2001, 637 clinical strains of S. pneumoniae were prospectively collected from 32 microbiology laboratories. RESULTS: Fifty one percent of strains were isolated from children under 15 years of age and 49% from adults. In children, 76% of strains came from otitis media, 20% from blood culture, in adults most strains (92%) came from blood culture. The overall prevalence of non-susceptible penicillin pneumococci was 61% higher in children (73%) than in adults (50%). Among the non-susceptible penicillin pneumococci 21.8% were resistant (CMI > 1 mg/l). Strains with decreased susceptibility to amoxicillin and cefotaxime were 38% and 17% respectively. Resistant strains to these two drugs (CMI > 2 mg/l) were rare 2.6% and 0.4% respectively. Among other antimicrobial agents, rate of resistance was 63% to erythromycin, 47% to cotrimoxazole, 40% to tetracycline, and 23% to chloramphenicol. The most frequent serogroups were serogroups 19 and 14, respectively 23% and 18%. Serotypes included in heptavalent vaccine covered 90% of children strains under 2 years of age. CONCLUSIONS: The prevalence of resistance to penicillin was high in children particularly in otitis media pus (76%).

Adult↗
PubMed2002

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE) in Northern France: a five-year multicentre incidence study.

In order to measure the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and of Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE), and to evaluate the impact of the national guidelines for multidrug-resistant bacteria (MDRB) prevention in hospitals of Northern France, a multicentre study was conducted for three months every year starting in 1996, in volunteer hospital laboratories. All clinical specimens positive for MRSA and ESBLE were prospectively surveyed. During the five-year surveillance period, the overall proportion of MRSA was 38.4% in the 28,534 strains of S. aureus, and that of ESBLE was 11.4% in the 6121 strains of Klebsiella pneumoniae and 47.7% in the 2353 strains of Enterobacter aerogenes. The overall incidence rates of clinical specimens positive for MRSA, ESBL-K. pneumoniae and E. aerogenes were 0.84. 0.05 and 0.12/1000 hospital-days (HD), respectively. In the 23 hospitals that participated in the survey every year, the proportion and incidence of ESBLE decreased. Hence, despite recommendations as for isolation precautions, MRSA remains poorly controlled and requires more effective measures.

Anti-Bacterial Agents↗
PubMed2001

Venous access port--related bacteremia in patients with acquired immunodeficiency syndrome or cancer: the reservoir as a diagnostic and therapeutic tool.

To describe the rate of response to an antibiotic-lock technique (ALT) in the treatment of venous access port (VAP)--related bacteremia and to analyze the role of the reservoir in the persistence of infection, we reported the data from 12 human immunodeficiency virus--infected and 8 oncologic patients with VAP-related bacteremia. The ALT consisted of intracatheter delivery of antibiotics and was associated with a systemic antibiotic infusion. We monitored clinical manifestations and performed qualitative and quantitative blood cultures during and at the end of the treatment. Four patients had catheters removed before antibiotic treatment. Of the 16 patients who were treated with the ALT, 5 (31%) were cured, as determined by negative cultures of blood and of samples from the catheter; 2 (12.5%) were cured but had recurrent infection with another microorganism; and 9 (56%) had persistent positive cultures of blood and of samples from the tip, reservoir, or both of the VAP. Limited efficacy of the ALT might be explained by the presence of deposits of fibrin that include clusters of bacteria inside the reservoir of the port.

AIDS-Related Opportunistic Infections↗
PubMed2001

Definite streptococcus bovis endocarditis: characteristics in 20 patients.

OBJECTIVE: To determine the specific characteristics of Streptococcus bovis infective endocarditis (IE) by reviewing our own experience of S. bovis IE. METHODS: Twenty episodes of definite S. bovis IE were reviewed in 20 patients hospitalized from 1980 to 1996. RESULTS: The mean age was 62 +/- 14 years, and 14 (70%) patients had no known predisposing cardiac condition. The principal antimicrobials used were penicillin G (N = 10) and amoxycillin (N = 8). Surgery was required in four (20%) patients. Neurologic complications occurred in eight (40%) patients, after initiation of therapy in six (75%) (mean time: 14 days). An unfavorable outcome was observed in four of 20 patients and tended to be more frequent in patients who had had neurologic complications (P = 0.10). Colonic tumors were present in 11 of 16 (69%) patients. CONCLUSIONS: Advanced age, occurrence of IE on presumably normal valves, high rate of neurologic complications, associated gastrointestinal diseases and low mortality rate during initial follow-up are characteristic features of S. bovis IE observed in this study.

Adult↗
PubMed2001

EETs relax airway smooth muscle via an EpDHF effect: BK(Ca) channel activation and hyperpolarization.

Epoxyeicosatrienoic acids (EETs) are produced from arachidonic acid via the cytochrome P-450 epoxygenase pathway. EETs are able to modulate smooth muscle tone by increasing K(+) conductance, hence generating hyperpolarization of the tissues. However, the molecular mechanisms by which EETs induce smooth muscle relaxation are not fully understood. In the present study, the effects of EETs on airway smooth muscle (ASM) were investigated using three electrophysiological techniques. 8,9-EET and 14,15-EET induced concentration-dependent relaxations of the ASM precontracted with a muscarinc agonist (carbamylcholine chloride), and these relaxations were partly inhibited by 10 nM iberiotoxin (IbTX), a specific large-conductance Ca(2+)-activated K(+) (BK(Ca)) channel blocker. Moreover, 3 microM 8,9- or 14,15-EET induced hyperpolarizations of -12 +/- 3.5 and -16 +/- 3 mV, with EC(50) values of 0.13 and 0.14 microM, respectively, which were either reversed or blocked on addition of 10 nM IbTX. These results indicate that BK(Ca) channels are involved in hyperpolarization and participate in the relaxation of ASM. In addition, complementary experiments demonstrated that 8,9- and 14,15-EET activate reconstituted BK(Ca) channels at low free Ca(2+) concentrations without affecting their unitary conductance. These increases in channel activity were IbTX sensitive and correlated well with the IbTX-sensitive hyperpolarization and relaxation of ASM. Together these results support the view that, in ASM, the EETs act through an epithelium-derived hyperpolarizing factorlike effect.

8,11,14-Eicosatrienoic Acid↗
PubMed2000

Variability and immunogenicity of caprine arthritis-encephalitis virus surface glycoprotein.

The complete surface glycoprotein (SU) nucleotide sequences of three French isolates of caprine arthritis-encephalitis virus (CAEV) were determined and compared with those of previously described isolates: three American isolates and one French isolate. Phylogenetic analyses revealed the existence of four distinct and roughly equidistant evolutionary CAEV subtypes. Four conserved and five variable domains were identified in the SU. The fine specificities of antibodies produced against these domains during natural infection were examined using a pepscan analysis. Nine immunogenic segments were delineated throughout the conserved and variable domains of SU, two of them corresponding to conserved immunodominant epitopes. Antigenic determinants which may be involved in the immunopathogenic process induced by CAEV were identified. These results also provide sensitive and specific antigen peptides for the serological detection and differentiation of CAEV and visna/maedi virus infections.

Amino Acid Sequence↗
PubMed1999

Levofloxacin: serum bactericidal activity against methicillin-resistant Staphylococcus aureus isolates.

The aim of this study was to assess the serum bactericidal activity (SBA) of levofloxacin compared with that of ofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) isolates. Serum from 10 healthy volunteers (seven females, three males) was collected after a single oral dose of either levofloxacin (500 mg) or ofloxacin (400 mg). Subjects were allocated randomly to treatment after at least a 1 week interval between antibiotic regimens. Three well-defined MRSA strains were tested, each susceptible to levofloxacin and ofloxacin, with different levels of resistance to methicillin (HBD 456, HBD 3 and HBD 2; class 1, 2 and 3 Tomasz heterogeneous resistance, respectively) together with a methicillin-susceptible (MSSA) reference strain (S. aureus ATCC 25,923). SBA was tested in vitro by a microtitration method 15 min before dosing and at 1, 4, 8 and 12 h after drug absorption. Levofloxacin was significantly more bactericidal than ofloxacin against all strains of S. aureus tested (SBA > or = 1:2). An SBA was recorded for only a short period with ofloxacin, and thereafter only bacteriostatic activity remained. This study, therefore, confirms the superior activity of levofloxacin over that of ofloxacin against MSSA and MRSA.

Anti-Infective Agents↗
PubMed1999

[Plasma homocysteine is not a predictive factor of restenosis after coronary angioplasty].

Hyper-homocysteinaemia is a cardiovascular risk factor. In parallel, anatomopathological studies of post-angioplasty coronary restenosis show histological appearances similar to those observed in patients with severe hyper-homocysteinaemia. Based on these histological observations, the authors tried to assess the predictive value of raised plasma homocysteine levels for coronary restenosis after angioplasty. Two hundred and twenty-two patients treated by coronary angioplasty were followed up clinically for 6 months. Thallium 201 myocardial scintigraphy was performed in 179 patients and coronary angiography in 74 patients. Seventy-nine patients had coronary restenosis diagnosed by coronary angiography in 55 cases, by myocardial scintigraphy in 23 cases and strongly suspected clinically in only one patient. No significant differences in homocysteine levels were observed between patients with multiple restenosis or requiring revascularisation, and those without restenosis and not requiring revascularisation. Plasma homocysteine does not therefore seem to be a predictive factor of post-angioplasty coronary restenosis.

Aged↗
PubMed1998

Women's health care work in comparative perspective: Canada, Sweden and Czechoslovakia/Czech Republic as case examples.

This paper contends that there is no single definition of caring work, that it holds no intrinsic meaning in and of itself. While in every human society there are work tasks that involve caring for others unable to adequately care for themselves, such caring work is almost always assigned in accordance with the overriding gender systems. However, different economic structures and gender ideologies, supported by different types of state formations, tend to organize caring work in a multiplicity of ways. Drawing on data from primary and secondary research on the related health care occupations of midwifery, obstetrical nursing, and general nursing in three societal locations - Canada, Sweden and Czechoslovakia/Czech Republic - the authors suggest that the social organization of women's health caring work is the product of a complex interweaving of factors. The formation of the state, and the specific social construction of the "public" and "private" spheres of society, play consequential roles in this process.

Canada↗
PubMed1998

Phenotypic and genotypic characterization of virulent yersinia enterocolitica strains unable to ferment sucrose.

Several atypical sucrose-negative Yersinia strains, isolated from clinical samples and sometimes associated with symptoms, proved to have full virulence potential in in vitro and in vivo testings. DNA-relatedness studies revealed that they were authentic Yersinia enterocolitica strains. Therefore, atypical sucrose-negative Yersinia isolates should be analyzed for their virulence potential.

Adult↗
PubMed1997

North American and French caprine arthritis-encephalitis viruses emerge from ovine maedi-visna viruses.

The full extent of genetic diversity among small ruminant lentiviruses (SRLVs), i.e., caprine arthritis encephalitis viruses (CAEVs) and maedi-visna viruses (MVVs), remains unknown. This is due in part to the fact that few sequences of CAEV are available. To contribute to this knowledge, gag, pol, and env nucleotide sequences from an SRLV named CA680 originating from a goat from western France were determined. This analysis revealed that this virus is closely related to the Cork and 63 CAEV American isolates. Mismatched amino acids between the CA680 virus and prototype CAEVs ranged from 6.7, 0. 7, and 17.5% for gag, pol, and SU sequences, respectively. The differences between the CA680 virus and MVV prototypes ranged from 16.5, 12.5, and 32.3% for the protein sequences, respectively. A screening using a heteroduplex mobility assay (HMA) adapted to SRLVs revealed that 6 of 10 caprine virus field isolates were closely related to CA680, indicating that this latter isolate was a prototype of CAEVs common in the west of France. Phylogenetic trees drawn using CA, RT, or SU sequences of numerous SRLVs and rooted with EIAV sequences revealed that CA680 and CAEV prototypes, all infectious for goat, clustered in one group. From these HMA and phylogenetic analyses, it appears that U.S. and French caprine SRLVs form a clade that had emerged from a much more diverse group containing all SRLVs infectious for sheep. These ovine SRLVs form a more ancient group in which the EIAV is rooted.

Amino Acid Sequence↗
PubMed1996

[Serodiagnosis of human pathogenic Yersinia infections].

OBJECTIVES: The test classically used for the serological diagnosis of yersiniosis is based on the technique of agglutination of killed bacteria. The sensitivity of this technique is low and numerous cross reactions are observed. The aim of this work was to develop a new serological test based on the ELISA method and to compare the results obtained by this method and by agglutination. METHODS: The antigens used for the ELISA test were the virulence plasmid-encoded proteins present in all pathogenic Yersinia and specific for this bacterial genera. The background of this technique was determined using 30 normal human sera. Validation of the ELISA method was performed with human sera negative (23) or positive (72) by the agglutination technique. The sensitivity of the ELISA test was compared with that of agglutination using 10 patients' sera which remained negative by the agglutination test despite the isolation of a pathogenic Yersinia. Finally, the ELISA specificity was determined with the sera of patients suffering from tuberculosis (20), typhoid fever (6), suspected or confirmed brucellosis (5) and suspected yersiniosis but having a positive Wright reaction (13). RESULTS: We show here that, in addition to the advantages inherent in the ELISA technique, this test is more sensitive and specific than the agglutination test. Furthermore, the ELISA test can be used for all pathogenic Yersinia, whatever their serotype and biotype. CONCLUSION: The use of the ELISA test should significantly improve the serodiagnosis of yersiniosis.

Adult↗
PubMed1996

[Increase of sialic acid concentration in the plasma of patients with coronary disease].

OBJECTIVES: Plasma levels of sialic acid are elevated in patients with coronary heart disease. We evaluated the specificity of this increase and attempted to correlate it with the severity of coronary lesions. METHODS: Total plasma sialic acid levels measured in 60 control subjects were compared with that in 135 patients with heart disease requiring coronarography. RESULTS: Plasma levels of sialic acid were significantly higher in patients (664 +/- 146 mg/l) than in controls (584 +/- 100 mg/l). In the group of patients, sialic acid level was only increased in those with coronary lesions - infarcts (738 +/- 166 mg/l) and angina (664 +/- 121 mg/l) - but was not raised above normal levels in those with other heart diseases (cardiomyopathy, valve failure, etc.). There was a positive correlation (p < 0.001) between raised sialic acid level and the severity of the coronary lesions as measured on coronarography. CONCLUSIONS: The elevated level of sialic acid in patients with coronary heart disease could be related to disorders in cell adhesion.

Adult↗
PubMed1996

Aspartame's effects on behavioral thermoregulation in albino rats.

Aspartame (L-aspartyl-L-phenylalanine methyl ester) was administered intraperitoneally to 9 Sprague-Dawley rats partitioned into 2 studies (4 in Study 1 and 5 for a replication in Study 2) over a two-year period using a within-subjects, repeated-measures reversal design. Behavioral thermoregulation was assessed in a cold Skinner Box using 5-sec. exposures of microwave radiation [Specific Absorption Rate = 0.34 Watts/kg/(mW/cm2)] as reinforcing stimuli under a fixed-interval 2-min. schedule of positive reinforcement. Two factorial analyses of variance [5 (doses) x 8 (hours)] indicated that the main effect for the doses of aspartame (2, 4, 8, 16 mg/kg, and saline control) was not significant; yet, the interaction (dose x hours) was significant (p < .05). Tentatively, aspartame should not cause an uncomfortable rise in body temperature (as sugar can do) when consumed in common substances such as soft drinks, yogurt, tea, coffee, etc., in doses commensurate with "hedonic" sweetness.

Animals↗