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Biomedical subjects

C Simon

Publications and source records attributed to C Simon.

At least 469 records · Page 26Linked to original sources
PubMedDate not supplied

Prevalence and sociodemographic determinants of overweight in young French adolescents.

BACKGROUND: The prevalence of overweight in adults and in children is increasing in most industrialised countries. Our purpose is to estimate the prevalence of overweight and obesity in a population of 12-year-old French adolescents and to analyse its association with different sociodemographic factors. METHODS: A cross-sectional study was conducted in 2001 on a representative sample of sixth-grade adolescents (mean age 12.1 +/- 0.6 years) living in the Department of the Bas-Rhin (Eastern part of France). Height and weight were measured in 4326 adolescents. Overweight and obesity were defined as recommended by the International Obesity Task Force. Sociodemographic data were obtained for 3436 adolescents. RESULTS: The prevalence of overweight was 22.7% (17.5% of moderate overweight and 5.2% of obesity) and it was not different by gender or by size of the commune of residence. Overweight was more frequent in low economic zones (p < 10(-4) in girls, p < 10(-2) in boys) and in public schools than in private schools (p < 10(-3) in girls). The prevalence of overweight was inversely associated with family income tax (p < 10(-3) in girls, p = 0.012 in boys), mother's (p = 10(-4) in girls, p = 10(-3) in boys) and father's (p = 0.001 in girls, p = 0.004 in boys) educational level. Multiple logistic regression analysis indicated an independent association of being overweight with low family income tax (p = 0.2195) and poor mother's educational level (p = 0.0193). CONCLUSIONS: This study indicates that, as in other industrialised countries, much overweight and obesity are present in 12-year-old French adolescents. It suggests the existence of an influence of socio-economic factors with a predominant effect of the mother's educational level rather than the financial resources.

Adolescent↗
PubMedDate not supplied

In vitro comparison of fluid blood culture media.

Eight fluid blood culture media from different manufacturers were compared with regard to their ability to culture fastidious microorganisms. In turbidity measurements following inoculation with different bacteria, the media differed with respect to the duration of the lag phase and the log phase of bacterial growth. Similar differences were observed with small inocula in original blood culture bottles (commercially available). Fastidious microorganisms grew better in Supplemented Peptone Broth II (Becton-Dickinson), BHI Roche and BHI bioMérieux. Meningococci could only be cultured in four of the eight media tested, and pneumococci in seven of the eight media (with different velocities of growth). Haemophilus influenzae showed the best results after adding blood or IsoVitalex BBL.

Bacteria↗
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In vitro activity of ceftazidime in combination with other antibiotics.

189 bacterial strains were investigated for their in vitro sensitivity against ceftazidime (alone and in combination with another antibiotic). Moreover, the possibility to prevent development of secondary bacterial resistance as observed in subcultures at subinhibitory antibiotic concentrations, was studied using specific antibiotic combinations. Of 115 staphylococcal strains (91 strains of Staphylococcus aureus, 24 strains of Staphylococcus epidermidis), 2% were sensitive, 82% were moderately sensitive and 16% were resistant to ceftazidime. On combining ceftazidime with vancomycin, synergism was found in 61% of the strains, and secondary resistance to ceftazidime could be prevented with this combination. The combination of ceftazidime and clindamycin showed synergism in 26% and an additive effect in 48% of the strains. Secondary resistance to ceftazidime did not develop with this combination in subcultures at subinhibitory concentrations in which loss of activity was only minimal with clindamycin alone. Rifampicin and fusidic acid were highly active against staphylococci. In combination with ceftazidime, only weak synergism or additive effects were seen in most strains; no antagonism could be observed. In subcultures at subinhibitory concentrations, secondary resistance to rifampicin and fusidic acid developed rapidly and could be partially prevented by adding ceftazidime. Of 60 Pseudomonas aeruginosa strains, 84% were sensitive, 13% were moderately sensitive and 2% were resistant to ceftazidime. Synergism was most frequently observed when ceftazidime was combined with tobramycin. Using this combination, secondary resistance of Pseudomonas strains to ceftazidime did not develop. When ceftazidime was combined with piperacillin, synergism was observed in most strains, but the development of secondary resistance in vitro was not prevented.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
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Neonatal sepsis in an intensive care unit and results of treatment.

Incidence and fatality of neonatal sepsis in intensive care units have been relatively high despite progress in the management of very ill neonates and combined treatment of sepsis with antibiotics. Between 1985 and 1989 944 children (632 premature babies and 312 term babies) were treated in the intensive care unit of the University Children's Hospital of Kiel. The incidence of sepsis was 5% (congenital sepsis 4%, sepsis acquired after birth 1%). Pneumonia occurred in 4% (congenital pneumonia in 2%, postnatal pneumonia in 2%). Early diagnosis and treatment with piperacillin plus cefotaxime reduced the mortality rate of sepsis to 2%. Sepsis never developed under treatment with piperacillin plus cefotaxime. Early recognition of neonatal sepsis by a good blood culture technique and beginning of treatment on first suspicion of sepsis with cefotaxime and piperacillin can improve the results especially in intensive care patients.

Cefotaxime↗
PubMedDate not supplied

In vitro activity of flomoxef in comparison to other cephalosporins.

Flomoxef and cefazolin had nearly the same activity against staphylococci, which was stronger than that of other cephalosporins. Against Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus pneumoniae, cefotaxime and cefazolin were more active than flomoxef, but the other cephamycins were less active than flomoxef. In comparison to the other cephalosporins, latamoxef and flomoxef had higher activity against Branhamella catarrhalis, whereas cefotaxime, latamoxef and cefotetan were more active against Haemophilus influenzae. Flomoxef was the only drug exhibiting activity against Clostridium difficile. The activity of flomoxef and latamoxef against Bacteroides fragilis was stronger than that of the other cephalosporins, but Bacteroides bivius was resistant to each of these antibiotics.

Bacteria, Anaerobic↗
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In vitro activity of Ro 15-8074 and Ro 19-5247 in comparison to cefaclor and cefalexin.

805 clinical isolates were investigated for their in vitro sensitivity against Ro 15-8074 and Ro 19-5247 in comparison to cefaclor and cefalexin in a serial dilution test on solid medium. Ro 19-5247 had the strongest activity of all drugs tested against streptococci (except Streptococcus faecalis) and was as active as cefaclor and cefalexin against most strains of Staphylococcus aureus. Ro 19-5247 was the only oral cephalosporin active against Bordetella pertussis. It was on average 160 times more active than cefaclor against Haemophilus influenzae. In its activity against enterobacteria Ro 19-5247 was always superior to cefaclor and cefalexin. Only a few strains of Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Proteus vulgaris and Serratia marcescens were resistant to Ro 19-5247 as were all strains of Enterobacter agglomerans and Klebsiella ozaenae. Ro 15-8074 was inactive against staphylococci but ten times more active than cefaclor and cefalexin against Streptococcus pyogenes. There was no difference in the activity against Streptococcus pneumoniae and Streptococcus agalactiae. Against Haemophilus influenzae Ro 15-8074 acted 12 times stronger than cefaclor and 100 times stronger than cefalexin. The activity against enterobacteria corresponded to that of Ro 19-5247. Ro 15-8074 was also active against most strains of Enterobacter cloacae and Proteus vulgaris which were resistant to cefaclor and cefalexin.

Bacteria↗
PubMedDate not supplied

Nocturnal oscillations in plasma renin activity during sleep in hypertensive patients: the influence of perindopril.

In previous studies, we established a strong concordance between nocturnal oscillations in plasma renin activity (PRA) and REM-NREM sleep cycles. To determine whether this relation persists in the case of moderate essential hypertension and if it is influenced by antihypertensive therapies affecting renin release, six normal subjects and six hypertensive patients were studied. The normal subjects underwent one control night. The hypertensive patients were studied during a first night when a placebo was given. Four of them underwent a second night following a single dose of an angiotensin-converting enzyme (ACE) inhibitor, perindopril; and a third night, 45 days later, with the antihypertensive treatment. In addition, two of the patients underwent two night-studies, after a single and repeated doses of a beta-blocker, atenolol, to see whether preventing renin release modified the sleep structure. The relationship between the nocturnal PRA oscillations and the sleep stage patterns persisted in hypertensive patients receiving placebo. In patients who had low PRA levels, the increases associated with NREM sleep were small. However, the mean relative amplitude of the oscillations, expressed as a percentage of the nocturnal mean, was about 60%, which was similar to that in normotensive subjects. Active renin and PRA oscillations were closely coupled. ACE activity profiles displayed damped fluctuations and no systematic relationship with sleep stages.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Percolation on heterogeneous networks as a model for epidemics.

We consider a spatial model related to bond percolation for the spread of a disease that includes variation in the susceptibility to infection. We work on a lattice with random bond strengths and show that with strong heterogeneity, i.e. a wide range of variation of susceptibility, patchiness in the spread of the epidemic is very likely, and the criterion for epidemic outbreak depends strongly on the heterogeneity. These results are qualitatively different from those of standard models in epidemiology, but correspond to real effects. We suggest that heterogeneity in the epidemic will affect the phylogenetic distance distribution of the disease-causing organisms. We also investigate small world lattices, and show that the effects mentioned above are even stronger.

Disease Outbreaks↗
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Assisted reproduction in HIV and HCV infected men of serodiscordant couples.

In serodifferent couples, there is a significant risk of sexual transmission of HIV, while the risk of transmitting HCV is minor. That said, the whole of the ejaculate is not necessarily infected and, therefore, hazardous. A careful dissection of its components by which motile sperm is separated and subsequently analyzed to verify the absence of viral elements could allow these couples a safer access to the reproductive process. The development in the field of assisted reproduction of new laboratory techniques and reliable tests for confirming the presence of both viruses in semen have led to the achievement of pregnancies while avoiding the infection of the seronegative partner and offspring. The system of detection is often performed by means of RT-PCR methods. These protocols are sensitive, but the presence of polymerase inhibitors in semen interferes with the reactions, yielding a high number of false negatives or undetermined results. HIV affects sperm quality only in the most advanced stages of the disease, while the fertility of asymptomatic or mild symptomatic patients is not affected by the disease. This review explores the possibilities offered by assisted reproduction and molecular biology techniques to HIV and/or HCV serodiscordant couples by which they may conceive children with the minimum risk.

Female↗
PubMedDate not supplied

[Ultrasensitive determination of thyrotropin. Improvement in the performance and reduction of the cost of thyroid function tests].

The characteristics of an ultrasensitive thyrotropin (TSH) assay method using monoclonal antibodies (TSH-U) were determined in euthyroid subjects, either healthy or with extra-thyroid disease, in treated and untreated hyper-and hypothyroid subjects and in subjects under amiodarone. The thyroid function was evaluated by free thyroxine (FT4) and free triiodothyronine (FT3) assays and by TSH tests and TSH response to TRH. With a sensitivity of 1 and a specificity of 0.94, the TSH-U assay proved highly reliable to evaluate the thyroid function. Dysthyroidism can be excluded when TSH-U levels are normal (0.15 to 4.5 microU/ml). In case of low TSH-U level, measurements of FT4 and FT3 and, if required, thyroid gland scintigraphy are necessary to confirm a diagnosis of hyperthyroidism. In contrast, a high TSH-U level is sufficient for affirm diagnosis of hypothyroidism. The TSH-U assay makes the TRH test redundant and can differentiate between hyperthyroxinaemia with euthyroidism and with hyperthyroidism. It is an effective method to detect disorders in thyroid function and it calls for a re-evaluation of thyroid diagnostic strategy.

Adult↗
PubMedDate not supplied

[Anesthesia in resections and anastomoses of the trachea].

Resections and end-to-end anastomosis have been effective in correcting localized tracheal strictures. Important clinical considerations are the precise preoperative assessment of the lesion, careful planning of anesthetic management and choice of the appropriate decision. Surgical procedures involving sharing of the air way between the anaesthetist and the surgeon impose special problems on the anaesthetist. On the one hand, the surgeon requires unrestricted access to the operating site and on the other, the anaesthetist must ensure adequate anaesthesia, oxygenation and carbon dioxide elimination, preferably without contamination of the lung fields. The more commonly employed technique is the use of a tracheal tube so that anaesthesia can be maintained using conventional IPPV. In our experience, the majority of strictures in adults can be managed as well, or better, by using a conventional endotracheal tube.

Adult↗