Evaluation des modifications de conformation de la beta-lactoglobuline soumise a des traitements thermiques a pH neutre

SIGLEINIST T 76343 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Fermentation by lactic bacteria at two temperatures of pre-heated reconstituted milk. II - Dynamic approach of the gel construction

International audienceThe behaviour of heat-treated skim milk towards acidification by fermentation with lactic bacteria was studied at 30 °C and 42 °C. Rheological changes using dynamic oscillations and $^1$H-NMR relaxation time, T2, were studied with time and pH. Front-face intrinsic fluorescence measurements studied with principal component analysis were performed during fermentation. The gel was formed at 42 °C at a shorter time and a higher pH (5.53 $\pm$ 0.01) than at 30 °C (5.24 $\pm$ 0.13). The maximum in tan $\delta$ was higher at 42 °C than at 30 °C, but the G' values at pH 4.6 were the same at the two temperatures. The changes in T2 with pH were not greatly different at the two temperatures, but the dT2/dpH curves showed some differences with the temperature. The changes in T2 were due to the changes in the particle structure caused by the fermentation and were correlated with calcium solubilisation. Front-face fluorescence can detect a first shift of the maximal intensity toward lower wavelengths and a second shift toward longer wavelengths. These shifts were separated by the gel point and were due to changes in the environment of tryptophan residues in the protein chains. The discussion of these results and the comparison with GDL-induced gels take into account the limitation of the transfer of the acid and the protons from the aqueous to the colloidal phase and the subsequent heterogeneity of the gel.Fermentation de lait reconstitué et chauffé par des bactéries lactiques à deux températures. II. Approche dynamique de la construction du gel. Le comportement du lait écrémé traité thermiquement au cours de l'acidification par des bactéries lactiques est étudié à 30 et 42 °C. Les modifications rhéologiques par oscillations dynamiques et le temps de relaxation T2 en RMN du proton sont étudiés en fonction du temps et du pH. La fluorescence frontale intrinsèque étudiée conjointement avec l'analyse en composantes principales a été suivie au cours de la fermentation. La gélification du lait apparaît à un temps plus court et un pH plus élevé à 42 °C (5,53 $\pm$ 0,01) qu'à 30 °C (5,24 $\pm$ 0,13). Le pic de maximum de tan $\delta$ était plus marqué à 42 qu'à 30 °C, mais le G' à pH 4,6 avait la même valeur aux deux températures. Les changements de T2 au cours de l'acidification étaient peu différents aux deux températures étudiées, mais les courbes dT2/dpH montrent quelques différences entre 42 et 30 °C. Les changements de T2 sont dus à des changements de structure de la particule provoqués par la fermentation et sont corrélés à la solubilisation du calcium. La fluorescence frontale détecte un premier décalage des spectres vers des longueurs d'onde plus petites puis un décalage vers des longueurs d'onde plus grandes. Le point associé à l'inversion de l'environnement des tryptophanes des chaînes protéiques correspond au point de gel. Ces résultats et les différences avec des gels acides obtenus par l'addition de GDL sont discutés en terme de limitation des transferts d'acides et de protons de la phase aqueuse vers la phase colloïdale et de l'hétérogénéité du gel qui en découle

Cannabis Use Is Inversely Associated with Overweight and Obesity in Hepatitis B Virus-Infected Patients (ANRS CO22 Hepather Cohort)

International audienceBackground: Chronic hepatitis B virus (HBV) infection may evolve into cirrhosis and hepatocellular carcinoma, and this progression may be accelerated by specific risk factors, including overweight and obesity. Although evidence for a protective effect of cannabis use on elevated body weight has been found for other populations, no data are available for HBV-infected patients.Aims: We aimed to identify risk factors (including cannabis use) for overweight and obesity in patients with HBV chronic infection.Methods: Using baseline data from the French ANRS CO22 Hepather cohort, we performed two separate analyses, one using “central obesity” (based on waist circumference) and the other “overweight” and “obesity” (based on body mass index) as outcomes. Logistic and multinomial regressions were used to model central obesity and overweight/obesity, respectively.Results: Among the 3706 patients in the study population, 50.8% had central obesity, 34.7% overweight, and 14.4% obesity. After multivariable adjustment, current cannabis use was associated with a 59% lower risk of central obesity compared with no lifetime use (adjusted odds ratio [95% CI]: 0.41 [0.24 to 0.70]). It was also associated with a 54% and 84% lower risk of overweight (adjusted relative risk ratio [95% CI]: 0.46 [0.27 to 0.76]) and obesity (0.16 [0.04 to 0.67]), respectively.Conclusions: Cannabis use was associated with lower risks of overweight and obesity in patients with HBV chronic infection. Future studies should test whether these potential benefits of cannabis and cannabinoid use translate into reduced liver disease progression in this high-risk population

Cannabis Use Is Inversely Associated with Overweight and Obesity in Hepatitis B Virus-Infected Patients (ANRS CO22 Hepather Cohort)

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Cannabis use as a factor of lower corpulence in hepatitis C-infected patients: results from the ANRS CO22 Hepather cohort

International audienceBackground: Patients with chronic hepatitis C virus (HCV) infection are at greater risk of developing metabolic disorders. Obesity is a major risk factor for these disorders, and therefore, managing body weight is crucial. Cannabis use, which is common in these patients, has been associated with lower corpulence in various populations. However, this relationship has not yet been studied in persons with chronic HCV infection.Methods: Using baseline data from the French ANRS CO22 Hepather cohort, we used binary logistic and multinomial logistic regression models to test for an inverse relationship between cannabis use (former/current) and (i) central obesity (i.e., large waist circumference) and (ii) overweight and obesity (i.e., elevated body mass index (BMI)) in patients from the cohort who had chronic HCV infection. We also tested for relationships between cannabis use and both waist circumference and BMI as continuous variables, using linear regression models.Results: Among the 6348 participants in the study population, 55% had central obesity, 13.7% had obesity according to their BMI, and 12.4% were current cannabis users. After multivariable adjustment, current cannabis use was associated with lower risk of central obesity (adjusted odds ratio, aOR [95% confidence interval, CI]: 0.45 [0.37-0.55]), BMI-based obesity (adjusted relative risk ratio (aRRR) [95% CI]: 0.27 [0.19-0.39]), and overweight (aRRR [95% CI]: 0.47 [0.38-0.59]). This was also true for former use, but to a lesser extent. Former and current cannabis use were inversely associated with waist circumference and BMI.Conclusions: We found that former and, to a greater extent, current cannabis use were consistently associated with smaller waist circumference, lower BMI, and lower risks of overweight, obesity, and central obesity in patients with chronic HCV infection. Longitudinal studies are needed to confirm these relationships and to assess the effect of cannabis use on corpulence and liver outcomes after HCV cure.Trial registration: ClinicalTrials.gov identifier: NCT01953458

Similar 5-year HCC occurrence in Tenofovir- and Entecavir-treated HBV chronic infection in the French AFEF/ANRS CO22 Hepather cohort.

International audienceBackground: Chronic hepatitis B virus (HBV) infection results in a high risk of cirrhosis and its complications, cirrhosis decompensation (DC), hepatocellular carcinoma (HCC), liver transplantation (LT), death or any of these outcomes (composite endpoint [CE]). Nucleos(t)ide analogues (NUCs) such as tenofovir or entecavir are associated with a reduction in these complications.Aim: To compare the impact of tenofovir and entecavir on these outcomes in patients treated for HBV infection and included in the prospective Hepather cohort.Methods: All patients with HBV infection who had received tenofovir or entecavir for more than 6 months at or after entry in the ANRS CO22 cohort were selected. Patients with HDV and HCV co-infection or prior liver event were excluded. Incidence rates of events were compared using inverse probability of treatment weighting (IPW).Results: The cohort included 1800 patients (986 tenofovir and 814 entecavir). Median follow-up was 4.2 years. The incidences of HCC, DC, LT, ACD, LRD and CE were not different between tenofovir- (1.8 (0.9; 3.2), 0.6 (0.2; 1.6), 0.2 (0.0; 0.8), 1.7 (0.8; 3.0), 0.8 (0.2, 1.8) and 4.1 (3.0; 5.4) per 1000 person-years) and entecavir-treated patients (1.6 (0.7; 3.0), 0.7 (0.2; 1.8), 0.2 (0.0; 1.0), 3.0 (1.7, 4.8), 0.5 (0.1; 1.5) and 5.0 (3.3; 7.2)) per 1000 person-years, respectively.Conclusion: The risk of liver-related events or death was not different between tenofovir- and entecavir-treated patients in this large prospective cohort of predominantly non-cirrhotic French patients.Trial registration number: NCT019553458

Early Hepatocellular Carcinoma Detection Using Magnetic Resonance Imaging Is Cost-Effective in High-Risk Patients with Cirrhosis

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