Association of HPC2/ELAC2 polymorphisms with risk of prostate cancer in a population-based study.

Genetic polymorphism in HPC2/ELAC2 was recently associated with risk of sporadic prostate cancer. To determine the contribution of two HPC2/ELAC2 missense variants (Ser217Leu and Ala541Thr) to the risk of developing prostate cancer, we conducted a population-based case-control study of middle-aged men (40-64 years). Cases (n=591) were ascertained from the Seattle-Puget Sound Surveillance, Epidemiology, and End Results Cancer Registry and Controls (n=538) from the same general population were identified through random-digit dialing. Subjects were residents of King County, Washington, and were frequency matched on age. Cases (32%) had a slightly higher frequency of the Leu217 variant compared with controls (29%), but there were no differences in the frequency of the Thr541 allele (4%). When considering joint genotypes, white men homozygous for the Leu217 variant on an Ala541/Ala541 background had an increased risk of prostate cancer [odds ratio (OR)=1.84; 95% confidence interval (CI), 1.11-3.06]. Different risk profiles were also observed when cases were stratified by disease aggressiveness. Men with at least one Leu217 allele had an elevated risk (OR=1.34; 95% CI, 1.02-1.76) of less aggressive prostate cancer (localized stage and Gleason score < or = 7), with a stronger association among men with two Leu217 alleles (OR=1.73; 95% CI, 1.08-2.77). The Ala541Thr polymorphism was not associated with risk, and neither variant was associated with more aggressive prostate cancer phenotypes. We estimate that the Ser217Leu genotype may account for approximately 14% of less aggressive prostate cancer cases and 9% of all sporadic cases in the general United States population of white men 相似文献   

Comprehensive mutational scanning of the p53 coding region by two- dimensional gene scanning

A comprehensive mutational scanning test for the p53 coding region based on multiplex PCR and two-dimensional DNA electrophoresis was designed and evaluated. In a 2-step multiplex PCR, the p53 coding region (exons 2-11) was amplified as a single 8646-bp fragment by long- distance PCR in step one. This fragment served as a template for the subsequent co-amplification of the individual exons in two multiplex groups in step two. The multiplex products were then separated, first on the basis of size in non-denaturant polyacrylamide gels and then on the basis of sequence by denaturing gradient gel electrophoresis (DGGE). Primers for optimal PCR, melting behavior and 2-D gel distribution were designed using a recently developed computer program. The resulting two-dimensional gene scanning (TDGS) test was evaluated by screening, in a blinded fashion, 29 coded DNA samples from Li- Fraumeni syndrome patients with previously identified germline mutations. All mutations were correctly detected. This assay provides an accurate, cost-effective and non-radioactive method for simultaneous mutational scanning of all p53 coding exons.      

Associations between both genetic and environmental biomarkers and lung cancer: evidence of a greater risk of lung cancer in women smokers

This molecular epidemiologic case-control study of lung cancer incorporated three complementary biomarkers: the glutathione S- transferase M1 (GSTM1) null genotype, a potential marker of susceptibility, and polycyclic aromatic hydrocarbon-DNA adducts (PAH- DNA) and sister chromatid exchanges (SCE), both indicators of environmentally induced genetic damage. Associations between biomarkers and lung cancer were investigated, as were possible gene-environment interactions between the GSTM1 null genotype and tobacco smoke exposure. Subjects included 136 primary non-small cell lung cancer surgical patients and 115 controls at the Columbia Presbyterian Medical Center. Questionnaire and Tumor Registry data, pre-treatment blood samples and biomarker measurements on blood were obtained. Overall, GSTM1 null genotype was significantly associated with lung cancer [odds ratio (OR) = 2.04, 95% confidence interval (CI) = 1.13-3.68]. ORs for GSTM1 and lung cancer were significant in females (2.50, 1.09-5.72) and smokers (2.25, 1.11-4.54) and not significant in males (1.4, 0.58-3.38) and non-smokers (0.88, 0.18-4.33). However, ORs for males versus females and smokers versus non-smokers did not differ significantly. The OR for GSTM1 and lung cancer in female smokers was 3.03 (1.09- 8.40), compared with 1.42 (0.53-4.06) in male smokers. In contrast to PAH-DNA adducts in leukocytes, SCE did not differ between cases and controls. Neither biomarker differed significantly between the two GSTM1 genotypes. The combined effect of elevated PAH-DNA adducts and GSTM1 genotype on case-control status (16.19, 1.2-115) appeared multiplicative. Results suggest that the effect of the GSTM1 null genotype is greatest in female smokers, which is consistent with other evidence that indicates that women are at higher risk of lung cancer than males, given equal smoking. Persons with both the GSTM1 deletion and elevated PAH-DNA adducts may represent a sensitive subpopulation with respect to carcinogens in tobacco smoke and other environmental media.      

Nonoperative treatment of rotator cuff tears

Rotator cuff tears and subacromial impingement are second only to acromioclavicular joint disorders as the most common causes of shoulder pain. Although most orthopedic surgeons are willing to initially treat shoulder impingement syndrome conservatively, they are reluctant to manage rotator cuff tears-especially full-thickness tears-nonoperatively. The purpose of this article is to explain the biomechanical rationale of nonoperative treatment, review the literature pertaining to nonoperative treatment of full-thickness rotator cuff tears, and describe a nonoperative treatment program.     

Causal effect of disconnection lesions on interhemispheric functional connectivity in rhesus monkeys

In the absence of external stimuli or task demands, correlations in spontaneous brain activity (functional connectivity) reflect patterns of anatomical connectivity. Hence, resting-state functional connectivity has been used as a proxy measure for structural connectivity and as a biomarker for brain changes in disease. To relate changes in functional connectivity to physiological changes in the brain, it is important to understand how correlations in functional connectivity depend on the physical integrity of brain tissue. The causal nature of this relationship has been called into question by patient data suggesting that decreased structural connectivity does not necessarily lead to decreased functional connectivity. Here we provide evidence for a causal but complex relationship between structural connectivity and functional connectivity: we tested interhemispheric functional connectivity before and after corpus callosum section in rhesus monkeys. We found that forebrain commissurotomy severely reduced interhemispheric functional connectivity, but surprisingly, this effect was greatly mitigated if the anterior commissure was left intact. Furthermore, intact structural connections increased their functional connectivity in line with the hypothesis that the inputs to each node are normalized. We conclude that functional connectivity is likely driven by corticocortical white matter connections but with complex network interactions such that a near-normal pattern of functional connectivity can be maintained by just a few indirect structural connections. These surprising results highlight the importance of network-level interactions in functional connectivity and may cast light on various paradoxical findings concerning changes in functional connectivity in disease states.     

Incomplete and delayed bioavailability of sublingual nitroglycerin

Eight healthy male volunteers received 16 doses of sublingual nitroglycerin tablets (0.4 mg). After 8 minutes, each subject rinsed out his mouth to halt the drug absorption process. The mouth rinses were assayed by high-performance liquid chromatography for residual nitroglycerin content. Each subject also received intravenous infusions of nitroglycerin so that the absolute bioavailability could be evaluated. Plasma nitroglycerin concentrations were determined using a specific and sensitive capillary gas chromatographic method capable of quantifying 25 pg/ml of nitroglycerin. The mean bioavailability (+/- standard deviation) of sublingual nitroglycerin, estimated from plasma concentrations, was 36.2 +/- 24.9% (range 2.6 to 113%). The amount of drug not absorbed after 8 minutes, as determined from the analysis of the mouth rinses, varied from 2.7 to 65.8% (mean 31.4 +/- 18.9%) of the administered sublingual dose. Mean nitroglycerin peak concentrations of 1.89 +/- 1.64 ng/ml were obtained at a mean peak time of 5.3 +/- 2.3 minutes. Thus, sublingual absorption is not instantaneous and can be relatively slow, with peak times of as long as 10 minutes. These data indicate that nitroglycerin pharmacokinetic values should not be estimated only from sublingual doses. Additionally, attempts to correlate pharmacodynamic measurements to sublingual doses must take into account the low and variable bioavailability and the potentially long peak times after sublingual nitroglycerin administration to patients.