Illuminating the life of GPCRs

The investigation of biological systems highly depends on the possibilities that allow scientists to visualize and quantify biomolecules and their related activities in real-time and non-invasively. G-protein coupled receptors represent a family of very dynamic and highly regulated transmembrane proteins that are involved in various important physiological processes. Since their localization is not confined to the cell surface they have been a very attractive "moving target" and the understanding of their intracellular pathways as well as the identified protein-protein-interactions has had implications for therapeutic interventions. Recent and ongoing advances in both the establishment of a variety of labeling methods and the improvement of measuring and analyzing instrumentation, have made fluorescence techniques to an indispensable tool for GPCR imaging. The illumination of their complex life cycle, which includes receptor biosynthesis, membrane targeting, ligand binding, signaling, internalization, recycling and degradation, will provide new insights into the relationship between spatial receptor distribution and function. This review covers the existing technologies to track GPCRs in living cells. Fluorescent ligands, antibodies, auto-fluorescent proteins as well as the evolving technologies for chemical labeling with peptide- and protein-tags are described and their major applications concerning the GPCR life cycle are presented

Risk factors for hepatitis C virus infection in male adults in Rawalpindi-Islamabad, Pakistan

Objective: To identify risk factors associated with HCV infection in Islamabad-Rawalpindi.Methods: Fifty-seven cases and 180 controls were enrolled from various departments of the nine major hospitals of the Rawalpindi-Islamabad during July-September 1998. Cases were enzyme-linked immunosorbent assay (ELISA) positive for antibodies to HCV (anti-HCV), aged 20-70 years, and residents of Islamabad or Rawalpindi division. Controls were anti-HCV ELISA negatives of the same age range and from the same area. A structured questionnaire was used to collect data on demographic variables and potential risk factors, which was analysed by logistic regression to calculate crude and adjusted odds ratios (OR) and corresponding 95% confidence intervals (CI) for risk factors.Results: The final multivariate logistic regression model revealed that after adjusting for age, cases were more likely to have received therapeutic injections in the past 10 years (1-10 vs. 0 therapeutic injections; adjusted OR=2.8, 95% CI: 1.1-7.1; \u3e 10 vs. 0 therapeutic injections; adjusted OR=3.1, 95% CI: 1.2-7.9) and were significantly more likely to have daily face (adjusted OR=5.1, 95% CI: 1.5-17.0) and armpit shaves (adjusted OR=2.9, 95% CI: 1.3-6.5) by a barber.CONCLUSION: HCV control and prevention programs in this region should include safe injection practices and educate men about the risk of HCV infection from contaminated instruments used by barbers