The effect of insulin and exercise on c-Cbl protein abundance and phosphorylation in insulin-resistant skeletal muscle in lean and obese Zucker rats.

Aims/hypothesis: Recruitment of the protein c-Cbl to the insulin receptor (IR) and its tyrosine phosphorylation via a pathway that is independent from phosphatidylinositol 3prime-kinase is necessary for insulin-stimulated GLUT4 translocation in 3T3-L1 adipocytes. The activation of this pathway by insulin or exercise has yet to be reported in skeletal muscle. Methods: Lean and obese Zucker rats were randomly assigned to one of three treatment groups: (i) control, (ii) insulin-stimulated or (iii) acute, exhaustive exercise. Hind limb skeletal muscle was removed and the phosphorylation state of IR, Akt and c-Cbl measured.  Results:   Insulin receptor phosphorylation was increased 12-fold after insulin stimulation (p<0.0001) in lean rats and threefold in obese rats. Acute exercise had no effect on IR tyrosine phosphorylation. Similar results were found for serine phosphorylation of Akt. Exercise did not alter c-Cbl tyrosine phosphorylation in skeletal muscle of lean or obese rats. However, in contrast to previous studies in adipocytes, c-Cbl tyrosine phosphorylation was reduced after insulin treatment (p<0.001). Conclusions/interpretation: We also found that c-Cbl associating protein expression is relatively low in skeletal muscle of Zucker rats compared to 3T3-L1 adipocytes and this could account for the reduced c-Cbl tyrosine phosphorylation after insulin treatment. Interestingly, basal levels of c-Cbl tyrosine phosphorylation were higher in skeletal muscle from insulin-resistant Zucker rats (p<0.05), but the physiological relevance is not clear. We conclude that the regulation of c-Cbl phosphorylation in skeletal muscle differs from that previously reported in adipocytes.

Chemiluminescence from the reaction of tin(II) with tris(2,2'-bipyridyl)ruthenium(III)

Unlike many other metal and metalloid ions, tin(II) elicits intense, analytically useful chemiluminescence upon reaction with tris(2,2΄-bipyridyl)ruthenium(III) in acidic aqueous solution. This finding provides new insight into the nature of this widely used reagent and has enabled the first direct, selective determination of a metal ion with tris(2,2΄-bipyridyl)ruthenium(III).

Green chemiluminescence from a bis-cyclometalated iridium(III) complex with an ancillary bathophenanthroline disulfonate ligand

The reaction of a fluorinated iridium complex with cerium(IV) and organic reducing agents generates an intense emission with a significant hypsochromic shift compared to contemporary chemically-initiated luminescence from metal complexes.

A role for the DRD4 exon III VNTR in modifying the association between nicotine dependence and neuroticism

Introduction: Neurotic psychopathology has been extensively examined as a risk factor for nicotine dependence (ND). Genetic stratification may partially explain variability in risk estimates. Genetic variants that compromise dopaminergic neurotransmission may motivate exposure to dopamine-stimulating agents, including nicotine. The 7-repeat allele of a Variable Number Tandem Repeat (VNTR) polymorphism in DRD4 (and evolutionary derivatives 5, 6, and 8 repeats; 7R+) is associated with reduced dopamine receptor function. The purpose of this study was to examine association between both smoking initiation (SI) and progression to ND by young adulthood and (a) history of neuroticism during adolescence, (b) DRD4 7R+, and (c) interaction between neuroticism and DRD4 7R+.

Methods: Participants were drawn from the Victorian Adolescent Health Cohort Study, a longitudinal study of the health and well-being of young Australians across 8 waves (14–24 years). Neuroticism was measured at Waves 3 and 6 (mean 15.9 and 17.4 years). SI was defined as any smoking at any wave. ND was measured at Wave 8 (mean 24.1 years). Genotype data for the DRD4 VNTR were available for 839 participants.

Results: While adolescent neuroticism was associated with SI, evidence for association with progression to ND was weak. However, there was evidence of interaction between neuroticism and DRD4 7R+: The odds of progression to ND among those with a history of neuroticism were more than 3.5-fold higher among 7R+ carriers.

Conclusions: Without considering stratification by 7R+, the association between progression to ND and neuroticism would have been assumed barely significant. However, among those carrying DRD4 7R+, risk of progression was considerably intensified.

Elevated levels of triglyceride and triglyceride-rich lipoprotein triglyceride induced by a high-carbohydrate diet is associated with polymorphisms of AP0A5-1131T>C and AP0C3-482C> in chinese healthy young adults

Background/aims: Changes in lipid profiles have been shown to be associated with diet and apolipoprotein (APO) polymorphisms. Therefore, 2 polymorphisms, i.e. APOA5-1131T>C and APOC3-482C>T, and serum lipids were examined in a Chinese healthy young population with high-carbohydrate/low-fat (HC/LF) diet intervention.

Methods: After a wash-out diet for 7 days, 56 young adults (22.89 +/- 1.80 years) received the HC/LF diet for 6 days. Body mass index (BMI) and fasting serum lipid profiles at baseline, after the wash-out diet, and after the HC/LF diet were measured.

Results: APOA5-1131C carriers had higher triglyceride (TG) and TG-rich lipoprotein TG (TRL-TG) levels at baseline and after the HC/LF diet, though this mainly corresponded to the female cohort. APOC3-482T carriers had higher TRL-TG levels following the wash-out and HC/LF diets, but these were not directly attributable to a single gender.

Conclusions: Both polymorphisms may play an important role in the elevated TG and TRL-TG levels induced by the HC/LF diet, especially in females, thus indicating a potential dietary prevention of coronary heart disease in this Chinese cohort.

Effects of lipoprotein lipase gene variations, a high-carbohydrate low-fat diet, and gender on serum lipid profiles in healthy Chinese Han youth

A high-carbohydrate low-fat (HC/LF) diet and lipoprotein lipase gene (LPL) Ser447Stop and Hind III polymorphisms have separately been found to be associated with triacylglycerol (TG) and high density lipoprotein cholesterol (HDL-C). This study sought to test the effects of LPL polymorphisms and an HC/LF diet on the serum lipid profile of Chinese with a lower incidence of coronary artery disease (CAD) consuming a diet with less fat and more carbohydrates. Fifty-six healthy subjects (22.89 ± 1.80 years) were given a control diet of 30.1% fat and 54.1% carbohydrates for 7 days, followed by an HC/LF diet of 13.8% fat and 70.1% carbohydrate for 6 days; there were no changes in the fatty acid composition or restrictions on total energy. Serum lipid profiles at baseline, before and after the HC/LF diet, and LPL polymorphisms were analyzed. After 6 days of the HC/LF diet, TG and the homeostasis model assessment of insulin resistance (HOMAIR) index were found to increase only in females with S447S. No decrease in HDL-C was noted. In subjects with Hind III polymorphism, increased TG was found in all females but not in males. Increased HDL-C, together with apolipoprotein (apo) AI, was found in male H- carriers but not in males with H+/H+ and females. In conclusion, LPL Ser447Stop and Hind III polymorphisms modified the effects of an HC/LF diet on the serum lipid profiles of a young Chinese population in different ways. Effective strategies for dietary interventions targeted at younger populations should take into account the interplay between genetic polymorphisms, diet, and gender.

Investigation of the WISC-III and WASI in clinical child populations : a framework for further exploration

To promote efficient clinical practice, interest has been growing in brief assessment scales to replace full-scale versions in some circumstances. In nonclinical populations, the Wechsler Abbreviated Scale of Intelligence (WASI) has substituted for the Wechsler Intelligence Scale for Children—Third Edition (WISC-III). Agreement between these scales remains untested in clinical populations. Twenty-five children, aged 6 to 15 years old were assessed. A correlational and within-participant design was used. These scales were significantly correlated. Despite a fourth edition of the WISC now available, WASI administration alone would at times appear to be a quick and valid estimate of IQ. Replication with the WISC-IV seems necessary to clarify the verbal/ performance distance criterion discrepancy and also the meaning of some variability between the scale and subtests.

Characterization of zebrafish polymerase iii promoters for the expression of short hairpin RNA interference molecules

RNA interference (RNAi) is a powerful, sequence specific, and long-lasting method of gene knockdown, and can be elicited by the expression of short-hairpin RNA (shRNA) molecules driven via polymerase III type 3 promoters from a DNA vector or transgene. To further develop RNAi as a tool in zebrafish, we have characterized the zebrafish U6 and H1 snRNA promoters and compared the efficiency of each of the promoters to express an shRNA and silence a reporter gene, relative to previously characterized U6 promoters from pufferfish, chicken, and mouse. Our results show that the zebrafish polymerase III promoters were capable of effective gene silencing in the zebrafish ZF4 cell line, but were ineffective in mammalian Vero cells. In contrast, mouse and chicken promoters were active in Vero but not ZF4 cells, highlighting the importance of homologous promoters to achieve effective silencing.

Comparative analysis of type III interferon receptor and interferon-stimulated genes

The role of a new type of interferon, known as interferon lambda, involved in anti-viral immunity was investigated. The identification of this interferon and its receptor, and their associated stimulation of the antiviral genes, Viperin and ZAP, has important implications for preventing viral infections, such as avian influenza.

Bevacizumab for the treatment of high-grade glioma: an update after phase III trials.

Gliomas are highly vascular and rich in VEGF, which promotes angiogenesis. Bevacizumab is a monoclonal antibody against VEGF, inhibiting angiogenesis by preventing receptor activation. Early Phase II clinical trials using bevacizumab in both newly diagnosed and recurrent high-grade gliomas (HGG) showed promising results, but these have not been confirmed in recent Phase III trials. This review is an update including recently reported Phase II and III study results.