Immunological markers predicting outcome in patients with hepatitis C treated with interferon-alpha and ribavirin

Type 1 (T1) cytokine responses are required for the clearance of hepatitis C virus by cytotoxic T lymphocytes, but can promote liver damage. Interferon-alpha (IFN alpha) can be expected to promote T1 cytokine responses, so treatment outcome may depend on the T1/T2 cytokine environment and levels of immune activation at baseline. This model was tested by monitoring immunological markers in a pilot study of treatment na?ve patients given IFN alpha 2b and ribavirin, with the aim of finding markers that predict virological outcome. Soluble (s) CD26/dipeptidyl peptidase IV enzyme activity and levels of sCD30, bioavailable IL-6, sTNF-RI, IL-1ra and nitrite/nitrate (NO(2)(-)/NO(3)(-)) were measured. Levels of IL-1ra and bioavailable IL-6 were lower in patients than controls and did not change with therapy. Treatment decreased sCD26/dipeptidyl peptidase IV enzyme activities and sCD30 levels and increased NO(2)(-)/NO(3)(-) levels. High baseline sCD30 levels predicted an early (P = 0.008) and sustained (P = 0.03) virological response to therapy, suggesting treatment may be more effective in patients with a predominant T2 profile.     

Maintaining connexin43 gap junctional communication in v-Src cells does not alter growth properties associated with the transformed phenotype

Loss of connexin expression and/or gap junctional communication (GJC) has been correlated with increased rates of cell growth in tumor cells compared to their normal communication-competent counterparts. Conversely, reduced rates of cell growth have been observed in tumor cells that are induced to express exogenous connexins and re-establish GJC. It is not clear how this putative growth-suppressive effect of the connexin proteins is mediated and some data has suggested that this function may be independent of GJC. In mammalian cells that express v-Src, connexin43 (Cx43) is phosphorylated on Tyr247 and Tyr265 and this results in a dramatic disruption of GJC. Cells that express a Cx43 mutant with phenylalanine mutations at these tyrosine sites form functional gap junctions that, unlike junctions formed by wild type Cx43, remain functional in cells that co-express v-Src. These cells still appear transformed; however, it is not known whether their ability to maintain GJC prevents the loss of growth restraints that confine "normal" cells, such as the inability to grow in an anchorage-independent manner or to form foci. In these studies, we have examined some of the growth properties of cells with Cx43 gap junctions that remain communication-competent in the presence of the co-expressed v-Src oncoprotein.     

The effects of amino acid supplementation on muscular performance during resistance training overreaching

The purpose of this study was to examine the effects of amino acid supplementation on muscular strength, power, and high-intensity endurance during short-term resistance training overreaching. Seventeen resistance-trained men were randomly assigned to either an amino acid (AA) or placebo (P) group and underwent 4 weeks of total-body resistance training consisting of two 2-week phases of overreaching (phase 1: 3 x 8-12 repetitions maximum [RM], 8 exercises; phase 2: 5 x 3-5 RM, 5 exercises). Muscle strength, power, and high-intensity endurance were determined before (T1) and at the end of each training week (T2-T5). One repetition maximum squat and bench press decreased at T2 in P (5.2 and 3.4 kg, respectively) but not in AA, and significant increases in 1 RM squat and bench press were observed at T3-T5 in both groups. A decrease in the ballistic bench press peak power was observed at T3 in P but not AA. The fatigue index during the 20-repetition jump squat assessment did not change in the P group at T3 and T5 (fatigue index = 18.6 and 18.3%, respectively) whereas a trend for reduction was observed in the AA group (p = 0.06) at T3 (12.8%) but not T5 (15.2%; p = 0.12). These results indicate that the initial impact of high-volume resistance training overreaching reduces muscle strength and power, and it appears that these reductions are attenuated with amino acid supplementation. In addition, an initial high-volume, moderate-intensity phase of overreaching followed by a higher intensity, moderate-volume phase appears to be very effective for enhancing muscle strength in resistance-trained men.     

Molecular expression of myostatin and MyoD is greater in double-muscled than normal-muscled cattle fetuses

Excessive muscling in double-muscled cattle arises from mutations in the myostatin gene, but the role of myostatin in normal muscle development is unclear. The aim of this study was to measure the temporal relationship of myostatin and myogenic regulatory factors during muscle development in normal (NM)- and double-muscled (DM) cattle to determine the timing and possible targets of myostatin action in vivo. Myostatin mRNA peaked at the onset of secondary fiber formation (P < 0.001) and was greater in DM (P < 0.001) than in NM. MyoD expression was also elevated throughout primary and secondary fiber formation (P < 0.001) and greater in DM (P < 0.05). Expression of myogenin peaked later than MyoD (P < 0.05); however, it did not differ between NM and DM. These data show that myostatin and MyoD increase coincidentally during formation of muscle fibers, indicating a coordinated role in the terminal differentiation and/or fusion of myoblasts. Myostatin mRNA is also consistently higher in DM than NM, suggesting that a feedback loop of regulation is also disrupted in the myostatin-deficient condition.     

Biological monitoring of eutrophication in rivers

There is an increasing awareness of the need to assess the impact of nutrient enrichment on river ecosystems separately from the impacts of organic effluents. A range of methods have been proposed and some have moved from the development stage to practical use by water management organizations. The methods can be applied to broad surveys or provide baseline information to assess possible future change. In the latter case it is recommended that several different methods are used, especially where it is important to get reliable information on the long-term impact of improvements in effluent quality. Estimates of biomass measured as chlorophyll a have often been used for phytoplankton and sometimes also for benthic communities. However, a lot of care is needed in applying this method, because of the range of factors besides nutrient concentration which can influence values. Approaches based on the whole community have been developed by a number of research groups, usually involving semiquantitative estimates of abundance. There has also been a rapid increase in the use of indices based on the relative proportions of epilithic diatom species. The methodologies used by a number of research groups in Europe are broadly similar, making it possible to compare results between different regions. The development of indices based on macrophyte floristic composition in relation to river nutrient status is also under development, especially in France and UK. However, interpretation of the results is complicated where long-term changes are taking place in nutrient concentrations in the water, because of the varying contributions of sediment and water to different species of rooted plant. Bioassays can be especially helpful where it is desired to establish whether either N or P is limiting for a population of community.     

572. BERGENIA EMEIENSIS

Summary.  Bergenia emeiensis C.Y. Wu ex J.T. Pan is illustrated and described. Its relationship to other Himalayan species is discussed, and instructions for its cultivation are given.     

580. FRITILLARIA KARELINII

Summary.  Fritillaria karelinii Fisch. ex D.Don ( Liliaceae ) is illustrated. Its relationships with other species and the position of subgenus Rhinopetalum are discussed. Instructions for its cultivation are given.