18 research outputs found

    Etude de la régulation de l'expression des récepteurs du Tumor Necrosis Factor alpha (TNFalpha) au cours de l'infection par Toxoplasma gondii (modèle humain in vitro)

    No full text
    Toxoplasma gondii est un protozoaire opportuniste responsable de la toxoplasmose, affection pouvant entraîner des atteintes cliniques graves chez les immunodéprimés et en cas d'atteintes congénitales. Le TNF[alpha], cytokine pro-inflammatoire, a une importance primordiale dans le contrôle de l'infection toxoplasmique. Elle agit par l'intermédiaire de deux récepteurs membranaires :TNFR1 et TNFR2. Nous avons étudié l'expression des récepteurs du TNF[alpha] au cours de l'infection de cellules humaines fibroblastiques MRC5 et de cellules myélomonocutaires THP-1 par T. gondii. La modulation des TNFRs PAR T. gondii, in vitro, semble dépendre du type cellulaire utilisé. Nos résultats indiquent que l'infection de cellules d'origine macrophagique (THP-1) par les tachyzoïtes de la souche RH de T. gondii est responsable d'une baisse des TNFRs membranaires associée à une augmentation de la libération de TNFR1 solubles dans le milieu de culture. Nous montrons également qu'une pénétration active des parasites est nécessaire et que certains antigènes parasitaires thermosensibles semblent être impliqués. Ce mécanisme de régulation des TNFRs pourrait influencer le rôle du TNF[alpha] dans la toxoplasmose. En effet, ces formes solubles produites par clivage protéolytique des récepteurs membranaires sont capables de se fixer au TNF[alpha] et de réguler sa bio-activité.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

    Discrepancies between the Cockcroft-Gault and Chronic Kidney Disease Epidemiology (CKD-EPI) Equations: Implications for Refining Drug Dosage Adjustment Strategies

    No full text
    The dosages of many medications require adjustment for renal function. There is debate regarding which equation, the Chronic Kidney Disease Epidemiology (CKD-EPI) equation vs. the Cockcroft-Gault (CG) equation, should be recommended to estimate glomerular filtration rate.status: publishe

    Toxoplasma gondii infection can regulate the expression of tumour necorsis factor-alpha receptors on human cell in vitro

    No full text
    International audienceThe in vitro regulation of tumour necrosis factor (TNF)-α receptors during Toxoplasma gondii infection of human MRC5 fibroblasts and human myelomonocytic THP-1 cells was investigated. Cells were infected with the virulent RH of T. gondii. TNFR membrane receptors were analysed by flow cytometry with biotinylated TNF-α. Shedding of the soluble form of TNFR1 and TNFR2 in cell culture supernatants was measured by enzyme-linked immunosorbent assay, and expression of mRNA production of TNFR1 and TNFR2 was analysed by quantitative real-time ploymerase chain reaction, 1 h after infection. In the MRC5 cell line, T. gondii infection did not induce any up- or down-regulation of membrane TNFRs, soluble TNFRs or mRNA of TNFRs. However, THP-1 cell infection with living parasites induced a significant soluble TNFR1 release by THP-1 cells after 1 h. We detected an approximately 50% up-regulation (P < 0·01) of soluble TNFR1 in infected THP-1 cells compared to controls. No change in soluble TNFR2 levels was observed in the same conditions. Moreover, infection decreased the level of TNF membrane receptors, but had no effect on TNFR1 and TNFR2 mRNA levels. TNFR modulation by T. gondii infection, in vitro, depends on the cell type. Furthermore, our data suggest that living parasites control the shedding of the soluble form of TNFR1. This mechanism may influence the role of TNF-α in toxoplasmosis

    Estimating sodium intake from spot urine samples at population level: a validation and application study in French adults

    No full text
    The aim of this study was to assess the validity of the predictive INTERSALT equation using spot urine samples to estimate 24-h urinary Na (24-hUNa) excretion and daily Na intake among the French adult population. Among 193 French adults ('validation sample'), we assessed the validity by comparing predicted 24-hUNa excretion from spot urine and measured 24-hUNa excretion from 24-h urine collections. Spearman correlation coefficients and Bland-Altman plots were used and we calculated calibration coefficients. In a nationally representative sample of 1720 French adults ('application sample'), the calibrated predictive equation was then applied to the spot urine Na values to estimate 24-hUNa excretion and daily Na intake. In that sample, predicted Na intake was compared with that estimated from 24-h dietary recalls. Results were adjusted and corrected using calibration coefficients. In the validation sample, the measured 24-hUNa excretion was on average 14 % higher than the predicted 24-hUNa (+13 % for men and +16 % for women). Correlation between measured and predicted 24-hUNa excretion was moderate (Spearman r 0·42), and the Bland-Altman plots showed underestimation at lower excretion level and overestimation at higher level. In the application study, estimated daily salt intake was 8·0 g/d using dietary recalls, 8·1 g/d using predicted INTERSALT equation and 9·3 g/d after applying calibration coefficients calculated in the validation study. Despite overall underestimation of 24-hUNa excretion by spot urinary Na, the use of predictive INTERSALT equation remains an acceptable alternative in monitoring global Na intake/excreted in the French population but its use is not advised at the individual level. Na is an essential nutrient, mainly provided by the salt contained in foods and table salt used as condiment. Nevertheless, excessive Na consumption has adverse health outcomes, including high blood pressure and an increased risk of CVD and stroke (1-6). The average level of Na consumption has been estimated to be 3·95 g/d (equivalent to 10 g of salt) in sixty-six countries worldwide (7) , which is almost twice as much the amount recommended by the WHO (<2 g/d of Na) (8). Therefore, the reduction of population salt intake is a public health priority. However, quantification of discretionary salt (added by individuals) is particularly difficult in diet surveys (9) and accurate monitoring of salt intake can be challenging. As approximately 90 % of daily Na intake is excreted in the urine throughout the day (10) , 24-h urine collection is considered Abbreviations: 24-hUNa, 24-h urinary Na; ENNS, Etude Nationale Nutrition Santé
    corecore