Zinc deficiency is common in cirrhosis and may be involved in the alteration of ammonia metabolism. Rats with carbon tetrachloride-induced cirrhosis have high plasma ammonia and low serum and tissue zinc levels. We used this model to examine the effects of oral zinc supplementation on activities of plasma ammonia and liver ornithine transcarbamylase (a key enzyme in the urea cycle). These parameters were examined in two consecutive experiments. Each experiment included two groups of rats treated with carbon tetrachloride; one group received zinc in the drinking water during the induction of cirrhosis, and another served as a control group. Regardless of zinc supplementation, all carbon tetrachloride-treated rats exhibited similar micronodular cirrhosis, with similar histological appearance and liver function impairment. Cirrhotic rats without zinc supplementation showed high plasma ammonia and low serum and hepatic zinc levels and reduced liver ornithine transcarbamylase activity. Serum, hepatic zinc and liver ornithine transcarbamylase activity increased significantly in the zinc-supplemented group, and these rats' plasma ammonia levels became normal. Plasma ammonia level was significantly inversely correlated with liver ornithine transcarbamylase activity and positively correlated with serum and hepatic zinc content. Our results suggest that zinc deficiency may modify hepatic ornithine transcarbamylase activity and, therefore, ammonia disposal.

The aim of this study was to identify risk factors associated with osteoporosis in urban midlife Malaysian women and to assess the effectiveness of lifestyle intervention in bone loss prevention with hormone replacement therapy (HRT) as a positive control. A total of 514 disease-free, uterus-intact, non-HRT-using women aged 45 years and older were recruited into the study. After initial bone mineral density (BMD) assessments, they were randomized into three groups: GI (control), G2 (lifestyle intervention), and G3 (lifestyle intervention with HRT). The study group was composed of 67.5% Chinese, 27.8% Malay, and 4.2% Indians with a mean age of 51.07+/-5.28 years. Two-fifths were postmenopausal, and the prevalence of osteoporosis was 24.1%, seen predominantly at the hip. Postmenopausal women had significantly lower mean BMD and a higher incidence of osteoporosis compared with the premenopausal women, 42.1% vs. 11.1% (p<0.0005). A lower incidence of osteoporosis was found in women who took calcium supplementation regularly as opposed to those who do not, 18.7% vs. 29.3% (p=0.036). Age and a greater postmenopausal duration showed a significant negative association with BMD, whereas higher family income, weight, body mass index, and waist and hip circumference were positively correlated. After 18-20 months, the effect of intervention was assessed based on BMD values of 279 women at baseline and after intervention. Lifestyle intervention alone was effective in premenopausal women, preventing over 90% of spinal bone loss compared with the controls, who lost 11.6% (0.046 g/cm2) bone mass with similar losses of hip bone, 2.0% (0.026 g/cm2) vs. 1.5% (0.020 g/cm2). Premenopausal women on HRT also showed a substantial decrease in spine and hip BMD, 18.6% (0.081 g/cm2) and 9.0% (0.122 g/cm2), respectively. The lifestyle intervention program retarded postmenopausal bone loss by 21% and 37% compared with controls, who lost 9.6% (0.141 g/cm2) and 6.0% (0.138 g/cm2) bone mass at the spine and hip. In comparison, lifestyle intervention with HRT increased postmenopausal BMD by 12.7% (0.216 g/cm2) at the spine and 1.9% (0.042 g/cm2) at the hip. The changes in hip BMD were influenced by current age, ethnicity, and income, while intervention had the strongest effect on spine BMD changes. In conclusion, lifestyle intervention prevented spinal bone loss in premenopausal women and retarded postmenopausal spine and hip bone loss compared with controls. The benefits of physical activity on spine and hip BMD highlight its potential as a safe and cost-effective alternative to HRT, which is not advocated because of its potential adverse effects.

The goal of this study was to evaluate the presence of extrahepatic damage and the uniformity and reversibility of the histological findings in CCl4.induced liver cirrhosis in the rat. To verify these findings rats were sacrificed 2 and 10 weeks after a treatment consisting of ten intragastric doses of CCl4, administered weekly. All treated rats developed an irreversible micronodular cirrhosis with no damage to the brain, kidney and pancreas. Moreover, rats sacrificed 2 weeks after the last CCl4 dose showed a number of functional alterations usually observed in man. In particular, low branched chain/aromatic amino acids (BCAA/AAA) plasma ratio, high ammonia, low zinc and high insulin with normal blood glucose were obtained.

The present study has been finalized to perform the content of Zn, Cu, Cr, Se, Mn, F, Mo, Ni, and B in the preterm human milk over 21 d of lactation. Trace element (TE) contents were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-MS), and median concentrations of Zn, Cu, Cr, Se, Mn, and F observed in preterm milk did not demonstrate significant differences in comparison to levels shown in term milk. A statistical significant difference (p < 0.05) has been found among Mo, Ni, and B content in preterm milk for every stage of lactation. TE content of infant blood founded concentrations of Mo in preterm babies significantly (p < 0.01) lower than in term offsprings. Similar values of other TE content were obtained in blood of preterm and term newborns. These findings point to the need for a considerable reassessment of the existing dietary recommendation for Mo content in infant feeding.

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