Lipid mobilisation and oxidative stress as metabolic adaptation processes in dairy heifers during transition period.

The objective of this study was to evaluate metabolic disorders and oxidative stress in dairy heifers during the transition period. Possible relationships between lipid mobilisation indicators and oxidative stress markers were investigated as well. Nineteen dairy heifers were included in the study. Blood samples were collected at the time of estrus synchronisation in heifers, at insemination, three weeks after insemination, one week before calving, at calving and 1, 2, 4 and 8 weeks postpartum. Common metabolic parameters, beta-hydroxybutyrate (BHB), free fatty acids (FFA), paraoxonase-1 (PON1) activity and total antioxidative status (TAS) were analysed. Around insemination, no significant difference was observed in the majority of tested parameters (P>0.05). However, the transition period markedly affected the concentration of triglycerides, total cholesterol, HDL-C, BHB, FFA, TAS and PON1activity. Positive correlations between PON1 activity and total cholesterol, HDL-C and triglycerides were noted but inverse correlations with FFA, BHB and bilirubin were found indicating that PON1 activity changed with lipid metabolism and was influenced by negative energy balance. These findings suggest that lipid mobilisation and oxidative stress are part of a complex metabolic adaptation to low energy balance which reaches equilibrium later in advanced lactation.

[Etiology and outcome of liver granulomatosis: a retrospective study of 21 cases]. / Etiologies et évolution des hépatites granulomateuses : étude rétrospective de 21 cas consécutifs.

PURPOSE: To assess the etiologies and outcome of liver granulomatosis. METHODS: We analyzed all consecutive liver granulomatosis diagnosed in our internal medicine department from 2000 to 2008. RESULTS: Among 471 liver biopsies, 21 disclosed evidence of liver granulomatosis (4.5%), in sixteen women (76%) and five men, with a median age of 41years. Thirteen were caucasians (62%). At the time of diagnosis, six (28.5%) had isolated abnormal liver function tests, and fifteen (71.4%) presented with clinical manifestations. The underlying cause was identified in 18 cases (85.7%). Eleven (52.3%) were systemic diseases: five (23.8%) primary biliary cirrhosis, two (9.5%) primary sclerosing cholangitis, two (9.5%) common variable immunodeficiency, one (4.7%) Sjögren's syndrome, and one (4.7%) Behçet's disease. Two (9.5%) patients had sarcoidosis. Three (14.3%) liver granulomatosis were of infectious origin (tuberculosis, schistosomiasis, and hepatitis C virus), two (9.5%) were neoplastic (Hodgkin's lymphoma and liver cell adenoma), and three (14.3%) were idiopathic. With a median of 38 months of follow-up, four patients (19%, two common variable immunodeficiency and two sarcoidosis) developed portal hypertension, independently of cirrhosis. One patient died of cryptococcosis. CONCLUSION: In accordance with other European studies, systemic diseases are the main causes of hepatic granulomas. Liver granulomatosis related to common variable immunodeficiency and sarcoidosis are at risk of portal hypertension.

Transient elastography accurately predicts presence of significant portal hypertension in patients with chronic liver disease.

BACKGROUND: Hepatic venous pressure gradient (HVPG) is a prognostic marker in patients with cirrhosis. Transient elastography measures liver stiffness (LS). AIM: To assess the correlation between LS and HVPG and to investigate the performance of transient elastography for the diagnosis of significant portal hypertension (PHT). METHODS: Liver stiffness was measured by Fibroscan in 150 consecutive patients who underwent a liver biopsy with haemodynamic measurements. Usual clinical and biological data were collected. Significant PHT was defined as a HVPG > or = 10 mmHg. RESULTS: Hepatic venous pressure gradient was found to be > or = 10 mmHg in 76 patients. Cirrhosis was diagnosed in 89 patients. HVPG was found to be correlated with: LS (rho = 0.858; P < 0.001) and inversely correlated with prothrombin index (rho = -0.718; P < 0.001). Regarding significant PHT, AUROC for LS and prothrombin index were 0.945 [0.904-0.987] and 0.892 [0.837-0.947] respectively. The cut-off value of 21 kPa accurately predicted significant PHT in 92% of the 144 patients for whom LS was successful. CONCLUSION: Liver stiffness measurement is correlated with HVPG and transient elastography identifies patients with significant PHT.

Serum paraoxonase activity in dairy cows during pregnancy.

Preparturient dairy cows are at high risk of metabolic and reproductive disorders and oxidative stress is considered to be involved in these events. We investigated the serum paraoxonase activity in dairy cows during pregnancy and alterations in lipid and lipoprotein patterns in this period. The relation between paraoxonase activity and HDL-cholesterol concentration was also compared. The study was carried out on 76 pregnant lactating and 26 pregnant dry Holstein dairy cows. The serum paraoxonase activity was determined by the method of hydrolysing of paraoxon, while triglyceride, cholesterol and HDL-cholesterol concentrations were measured by the enzymatic kit methods. A significantly higher serum triglyceride concentration (P<0.001) was observed in dry cows compared to lactating cows. The total cholesterol and HDL-cholesterol concentrations were significantly lower (P<0.001) in dry cows than in lactating ones. In dry cows, paraoxonase activity was significantly lower than in those lactating (P<0.001). There was no significant difference in paraoxonase/HDL-cholesterol ratio between the investigated groups. It seems that the lower HDL concentration could be one of the causes of reduced paraoxonase activity considering the role of HDL as a carrier of most paraoxonase molecules in the blood. A decreased serum paraoxonase activity could diminish the effectiveness and total capacity of the whole antioxidative system during prepartum period in dairy cattle.