North American journal of medicine & science最新文献

Hepatitis C virus (HCV) infection is a major public health problem and a leading cause of chronic liver disease. Chronic HCV infection often follows a progressive course over years and can result in cirrhosis, hepatocellular carcinoma, and need for liver transplantation. In the United States alone, the estimated prevalence of HCV infection is up to 5.1 million persons. The optimal approach to detecting HCV infection is to screen persons for possible history of risks of exposure to virus and to test those selected individuals with risk factors. Both host and viral factors may be important contributors to the natural history of HCV. Currently, effective pharmacologic therapy are available to induce sustained virologic response (SVR) or virologic "cure," which results in improved morbidity and mortality. Patient education before treatment is essential and should include a full discussion of potential side effects. It is important to work collaboratively and closely with patients to ensure early recognition of adverse events and to effectively manage them in order to ensure treatment compliance. This paper provides a thorough overview on screening for the diagnosis, clinical management, and treatment indications and contraindications for chronic hepatitis C.

Inorganic nitrate has emerged as a therapeutic agent for cardiovascular disease; however, nitrate can also metabolize to carcinogenic nitrosamines under pathologic conditions. Few large epidemiologic studies have examined circulating levels of nitrate in relation to cardiovascular disease and cancer. Data on the validity of nitrate measurement in blood samples collected in typical epidemiologic settings are needed before nitrate can be evaluated as an exposure in large epidemiologic studies. We measured plasma levels of nitrate in three pilot studies to evaluate its laboratory variability, stability with delayed processing, and reproducibility over time among women from the Nurses' Health Study and healthy female volunteers. Laboratory variability of nitrate levels was fairly low, with a coefficient variation (CV) of 7%. Plasma nitrate levels in samples stored as whole blood on ice for up to 48 hrs before processing were very stable; the overall intra-class correlation (ICC) from 0 to 48 hours was 0.89 (95%CI, 0.70-0.97). The within-person reproducibility over a one-year period was modest, with an ICC of 0.49 (95% CI, 0.33- 0.94). Our results indicate that measurement of nitrate in plasma is reliable and stable in blood samples with delayed processing up to 48 hours. Within-person reproducibility was modest but data from this study can be used for measurement error correction in subsequent analyses. The measurement of nitrate cannot be widely used in epidemiologic research without the documentation of its stability and reproducibility.

Breast cancer incidence and the number of breast cancer survivors have been rapidly increasing among Chinese and Korean women in the United States. However, few data are available regarding quality of life in Asian American breast cancer survivors. This qualitative study aims to describe Asian American women's perceptions of quality of life and their breast cancer experiences. In-depth interviews with four Chinese and five Korean American breast cancer survivors and three oncologists were conducted in Chinese, Korean, or English. Interviews were recorded and transcripts were translated into English. Qualitative analyses were performed by two independent coders and then discussed and agreed upon by the research team. The respondents reported that the breast cancer experience had affected various domains of quality of life, but women reported having limited resources with which to cope effectively. Depression, anxiety, and stress were commonly reported, but women rarely discussed these issues with family and friends or sought professional help. As immigrants, women's loneliness and a lack of social support and culturally relevant resources seemed to be major barriers to maintaining good quality of life. Women also expressed interest in learning more about alternative therapies and relaxation skills. These findings can be used to help inform the development of a culturally appropriate intervention for Asian American breast cancer survivors. Future programs may provide information in women's native languages to teach skills to cope with stress and anxiety, increase women's self-efficacy within the context of their cultural background, and enhance social support among women from the same ethnic group.

Autism spectrum disorders (ASD) are neurodevelopmental disorders which are currently diagnosed solely on the basis of abnormal stereotyped behavior as well as observable deficits in communication and social functioning. Although a variety of candidate genes have been identified on the basis of genetic analyses and up to 20% of ASD cases can be collectively associated with a genetic abnormality, no single gene or genetic variant is applicable to more than 1-2 percent of the general ASD population. In this report, we apply class prediction algorithms to gene expression profiles of lymphoblastoid cell lines (LCL) from several phenotypic subgroups of idiopathic autism defined by cluster analyses of behavioral severity scores on the Autism Diagnostic Interview-Revised diagnostic instrument for ASD. We further demonstrate that individuals from these ASD subgroups can be distinguished from nonautistic controls on the basis of limited sets of differentially expressed genes with a predicted classification accuracy of up to 94% and sensitivities and specificities of ~90% or better, based on support vector machine analyses with leave-one-out validation. Validation of a subset of the "classifier" genes by high-throughput quantitative nuclease protection assays with a new set of LCL samples derived from individuals in one of the phenotypic subgroups and from a new set of controls resulted in an overall class prediction accuracy of ~82%, with ~90% sensitivity and 75% specificity. Although additional validation with a larger cohort is needed, and effective clinical translation must include confirmation of the differentially expressed genes in primary cells from cases earlier in development, we suggest that such panels of genes, based on expression analyses of phenotypically more homogeneous subgroups of individuals with ASD, may be useful biomarkers for diagnosis of subtypes of idiopathic autism.