Alpha-lipoic acid treatment ameliorates metabolic parameters, blood pressure, vascular reactivity and morphology of vessels already damaged by streptozotocin-diabetes

The present study investigated the effects of alpha-lipoic acid treatment (50 mg/kg/day) on the metabolism and vascular condition already damaged by streptozotocin (STZ)-diabetes in rats. Carbohydrate and lipid metabolism, oxidative stress and antioxidant status were assessed in non-diabetic controls, 12-week untreated diabetic and 12-week treated diabetic (untreated for 6 weeks and then treated with alpha-lipoic acid for the last 6 weeks) rats. Blood pressures of rats were measured by tail-cuff method. Vascular reactivity was evaluated in isolated aortic rings. Morphology of aorta was examined by electron microscopy technique. Alpha-lipoic acid treatment effectively reversed body weight, blood glucose, plasma insulin, cholesterol, triglycerides and lipid peroxidation levels of diabetic animals. STZ-diabetes resulted in increased blood pressure, which was partially improved by alpha-lipoic acid treatment. Although the superoxide dismutase (SOD) activity in aortic homogenates was not changed by diabetes or antioxidant treatment, catalase or glutathione peroxidase (GPx) activity significantly increased in untreated diabetic rats. Alpha-lipoic acid treatment improved catalase activity in diabetic aorta. The contractile effect of phenylephrine markedly increased in diabetic rings, which was completely reversed by alpha-lipoic acid treatment. The maximum vasorelaxant response of pre-contracted aortic rings exposed to cumulatively increased concentrations of acetylcholine was unaffected by diabetes or antioxidant treatment. Sodium nitroprusside-induced endothelium-independent relaxations were similar in all experimental groups. Various alterations caused by STZ-diabetes in aorta structure were partially ameliorated by alpha-lipoic acid treatment. The potency of alpha-lipoic acid on the reversal of hypertension by affecting vascular reactivity and morphology as well as general metabolism of diabetic rats confirms the importance of hyperglycemia-induced oxidative stress in the development of diabetes-induced vascular complications and suggests a potential therapeutic approach.     

The production of nitric oxide and TNF-alpha in peritoneal macrophages is inhibited by Dichroa febrifuga Lour

Nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) have been suggested to play an important role in endotoxin-mediated shock and inflammation. In this study, we investigated the effect of aqueous extract of Dichroa febrifuga Lour. (Saxifragaceae) roots, a traditional antimalarial drug, on the production of NO and TNF-alpha. The aqueous extract of D. febrifuga roots (AEDF) inhibited the secretion of NO and TNF-alpha in lipopolysaccharide (LPS) and/or interferon-gamma (IFN-gamma)-stimulated mouse peritoneal macrophages, without affecting cell viability. The protein level of inducible nitric oxide synthase (iNOS) in peritoneal macrophages was also decreased by AEDF. In addition, the serum level of NO was reduced by i.p. administration of AEDF. These results suggest that AEDF suppresses the endotoxin-induced inflammatory responses through inhibiting the production of NO and TNF-alpha, and could be used as an anti-inflammatory drug.     

Disrupted transforming growth factor-beta signaling and deregulated growth in human biliary tract cancer cells

Biliary tract carcinoma is a common neoplasm in Japan, and its treatment is difficult because it tends to promote fibrosis and easily invades surrounding tissues. To better characterize the biological features of this carcinoma, we investigated abnormalities in the transforming growth factor-beta (TGF-beta) signaling pathway in five human biliary tract cancer cell lines: RBE, KMBC, SK-ChA-1, Mz-ChA-1, and Mz-ChA-2. We stably transfected into these cells the luciferase reporter plasmid carrying promoter of the plasminogen activator inhibitor-1 gene, the expression of which is stimulated by TGF-beta1. Treating the KMBC and Mz-ChA-1 cells with TGF-beta1 neither inhibited cell growth nor stimulated luciferase activity. In contrast, the RBE and Mz-ChA-2 cells responded well to TGF-beta1 treatment. TGF-beta1-treated SK-ChA-1 cells exhibited attenuated luciferase activity and their growth was not inhibited. Smad4 mRNA was not detected in SK-ChA-1 and Mz-ChA-1 cells by Northern blot analysis. Genetic analysis disclosed a nonsense mutation in the Mad homologue 2a domain of the Smad4 gene in the SK-ChA-1 cells and a heterozygous deletion in the TGF-beta type II receptor gene in the KMBC cells. Expression of the exogenous Smad4 gene in the Mz-ChA-1 cells by transient transfection restored their luciferase activity. When these TGF-beta1-insensitive and less-TGF-beta1-sensitive cell lines were xenografted into nude mice, they developed tumors that had more prominent, intervening fibrosis (desmoplasia) than the tumors caused by TGF-beta1-sensitive cells. Thus, a tight correlation between disruption of the TGF-beta signaling pathway and deregulated growth of cancer cells has been demonstrated in biliary tract carcinoma. This seems to be a critical event in this carcinoma and may also be correlated with stromal cell reaction in cancer invasion.     

Effect of tetrandrine on experimental hepatic fibrosis induced by bile duct ligation and scission in rats

Tetrandrine, an alkaloid isolated from the Chinese medicinal herb Stephania tetrandra, has been shown to elicit antifibrotic effects in various cell types. In the present study, the effect of tetrandrine on liver fibrosis was investigated by using bile duct ligation and scission in rats as a model of hepatic fibrosis. Treatment with tetrandrine in fibrotic rats reduced serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels to 72%, 52% and 51% that of controls at 10 mg/kg/day, respectively. Liver hydroxyproline contents in tetrandrine-treated rats with bile duct ligation and scission were also reduced to 65% of that of control rats with bile duct ligation and scission at 10 mg/kg/day. The morphological characteristics of fibrotic liver, which appeared in control bile duct ligation and scission group, were improved in tetrandrine-treated bile duct ligation and scission group. We also examined the effect of tetrandrine on cultured rat hepatic stellate cells, which plays an important role in the pathogenesis of hepatic fibrosis, activation to investigate whether it could act mainly by direct action on rat hepatic fibroblastic cells. In cultured rat hepatic stellate cells, tetrandrine reduced DNA synthesis to 57% of control hepatic stellate cells at 10 microg/ml without affecting cell viability. Smooth muscle-alpha-actin expression, the phenotypic marker of activated hepatic stellate cells, was also decreased. We conclude that tetrandrine has an antifibrotic effect on liver fibrosis in rats induced by bile duct ligation and scission, indicating that it might exert a direct effect on rat hepatic stellate cells.     

Analysis of the pregnancy-related deaths within the last two decades: a university hospital-based study from Turkey

OBJECTIVE: To analyse the causes of pregnancy-related deaths at Ondokuz Mayis University Hospital. STUDY DESIGN: The death of a woman while pregnant or within 42 days of termination of pregnancy regardless of the cause of death, including accidental or incidental causes, was accepted as a 'pregnancy-related death'. Such deaths were evaluated in Ondokuz Mayls University Hospital in the years 1978-1997 inclusive. They were classified as direct obstetric, indirect obstetric, and accidental or incidental deaths. RESULTS: Eighty-seven pregnancy-related deaths were identified via hospital death records. Maternal mortality ratio was calculated to be 822.2 per 100,000 live births. Seventy seven percent of the deaths were due to direct obstetric causes; most commonly due to toxemia, infection and hemorrhage. CONCLUSION: Direct obstetric deaths, which are largely preventable with proper antenatal care and health services, are still problems in our country.     

Comparison of Etest with the broth microdilution method in susceptibility testing of yeast isolates against four antifungals

A comparative evaluation of the Etest and the broth microdilution methods for antifungal susceptibility testing of 102 clinical yeast isolates against amphotericin B, fluconazole, itraconazole, and ketoconazole was conducted. The agreements between the Etest and the broth microdilution methods were 93.1% for amphotericin B 85.2% for ketoconazole, 82.3% for itraconazole and 79.4% for fluconazole. These results suggest that the Etest approach to antifungal susceptibility testing may be a viable alternative to the NCCLS reference methods for testing yeasts, but that further evaluations are needed.     

Acid sphingomyelinase deficiency in Beckwith-Wiedemann syndrome

We report the association of Beckwith-Wiedemann syndrome (BWS) and a residual acid sphingomyelinase (ASM) activity of about 35% in a 23 months old Hungarian boy. Besides the classical triad of exomphalos, macroglossia and gigantism some other BWS-related features: polyhydramnios (known from the praenatal history), hemihypertrophy, craniofacial dysmorphy, a mild mental retardation, bilaterally undescended testes, cardiac anomalies and a terminally developed, fatal embryonal rhabdomyosarcoma were present in the patient. The decreased activity of the ASM was measured in the patient s skin fibroblasts. This result, with hepatomegaly, mental retardation, feeding problems, a failure to thrive and muscle-hypotony, partially resembled the ASM-deficient forms of Niemann-Pick disease (NPD). Morphological analysis of the bone-marrow cells gave normal results. There was no chromosomal alteration found by conventional karyotyping of the patient s lymphocytes.BWS-associated genes as well as the human ASM gene (SMPD1) are all located at 11p15. DNA-studies by region specific markers as well as mutational analysis for the most common NPD-mutations are planned in the future. This is the first report on the simultaneous occurrence of BWS and ASM-deficiency.