Chronic pancreatitis: ultrasonic features

A retrospective analysis of 84 ultrasound examinations (in 77 patients) was performed to assess the frequency of sonographic findings in chronic pancreatitis. The findings included: inhomogeneously increased echogenicity in 53% of these examinations, focal or diffuse enlargement in 41%, focal dense echoes in 40%, pseudocyst formation in 21%, and a hypoechoic head mass in 7%. Thirteen per cent of our patients had a normal sonogram. Several presentations of chronic pancreatitis not previously described in the sonographic literature included: pancreatic or common bile duct enlargement or pseudocyst formation with otherwise normal-appearing glands. There was no direct relationship between the presence of focal high-intensity echoes within the pancreatic parenchyma and the presence of radiographic calcification. There was no difference in the frequency of ultrasonic abnormalities between patients with and without clinical evidence of pancreatic insufficiency. These results indicate that the sonographic findings in chronic pancreatitis are significantly more varied than previous reports would indicate.     

Prostate-specific antigen as a biomarker of condom failure: comparison of three laboratory assays and self-reported condom use problems in a randomized trial of female condom performance

BackgroundProstate-specific antigen (PSA), a biomarker for semen exposure, may provide a more objective measure of condom failure than subject self-reports. Methods for measuring PSA vary and their comparability with respect to assessing condom performance has not been adequately evaluated. This study compared results from three different PSA assays of vaginal samples collected by subjects in a randomized clinical trial which compared the performance of female condoms.Study DesignWe selected 30 pairs of pre- and post-coital vaginal samples from subjects who reported condom functionality problems or whose original PSA assay was positive. Samples were retested using three different PSA assays [quantitative enzyme-linked immunoassay (EIA), rocket immune-electrophoresis (RIE) and chromatographic immunoassay (CIA)]. We compared the proportion of condom uses where the post-coital PSA result indicated semen exposure for each of the three assays.ResultsDespite varying levels of sensitivity, the results from all three assays were remarkably consistent. Self-reported condom failures did not correlate well with positive PSA results, suggesting that exclusive reliance on either PSA or user self-report may be inadequate for assessing condom functionality.ConclusionIn combination with user self-report of condom failure, PSA testing provides a reliable, objective marker of condom functionality. Studies based on PSA testing may improve on conventional contraceptive clinical trials by offering a more direct assessment of a condom product's ability to prevent semen exposure.     

Condom type may influence sexual behavior and ejaculation and complicate the assessment of condom functionality

BackgroundStudies that evaluate condom effectiveness are affected by factors related to how the condom was used, and these factors may not be consistent between different types of condoms. Also, subjective assessments of the sexual act may be unreliable.Study DesignWe performed a secondary data analysis of a randomized crossover trial of male and female condoms among 108 couples.ResultsSelf-reported duration and activeness of coital acts were significantly different for uses of the male condom compared to uses of the female condom. Fewer individuals reported ejaculation occurring with the female condom. Reliability of self-reports of ejaculation compared to a biological marker of semen detected inside the used male and female condoms was not strong.ConclusionsWe found that sexual behaviors appear to differ by the type of condom used for the coital act. Studies should consider sexual behavior when evaluating condom effectiveness. Furthermore, studies would be strengthened by the use of a biological marker of semen to determine whether ejaculation, and therefore a true risk of exposure, occurred.     

Application of the case-crossover design to reduce unmeasured confounding in studies of condom effectiveness

This analysis examined how unmeasured confounding affects estimates of the effectiveness of condoms in preventing sexually transmitted infections. Data were analyzed from a prospective cohort study of 1,122 female sexually transmitted disease clinic patients in Alabama (1992-1995), wherein participants were evaluated for sexually transmitted infections at six 1-month intervals. Associations between condom use and incident gonorrhea and chlamydia infection were compared between case-crossover and cohort analyses. In a case-crossover analysis of 228 follow-up visits ending in gonorrhea/chlamydia ("case intervals") and 743 self-matched follow-up visits not ending in gonorrhea/chlamydia ("noncase intervals") (183 women), consistent condom use without breakage or slippage was associated with significantly reduced risk of infection relative to nonuse (adjusted risk odds ratio = 0.49, 95% confidence interval: 0.26, 0.92). Conversely, a cohort analysis of 245 case intervals and 3,896 noncase intervals (919 women) revealed no significant reduction in infection risk from consistent use of condoms (adjusted risk odds ratio = 0.79, 95% confidence interval: 0.53, 1.17). Dose-response relations between the number of unprotected sex acts and infection were stronger in the case-crossover analysis (p for trend = 0.009) than in the cohort analysis (p for trend = 0.18). These findings suggest that epidemiologic studies confounded by unmeasured differences between condom users and nonusers underestimate condom effectiveness against these infections. The case-crossover method provides an additional technique for reducing unmeasured confounding in studies of condom effectiveness.     

Participation and retention in a study of female condom use among women at high STD risk

PURPOSE: Differential participation and retention can bias the findings of a follow-up study. This problem was evaluated in a study of barrier contraception among women at high STD risk. The goal of this study was to identify predictors of participation and retention and determine whether they could influence study results. METHODS: Six-month follow-up study of women attending STD clinics. Determinants of participation and retention were evaluated using logistic and proportional hazards models. RESULTS: Agreement to participate was associated with young age, black race, low education and income, older age at first intercourse, the number of lifetime partners, and STD history. Early attrition was associated with young age, non-black race, higher income, lack of interest/commitment to using the female condom, high coital frequency, no STD history, not using a birth control method at baseline, and with inconsistent condom use, high coital frequency, and pregnancy during follow up. CONCLUSIONS: There was little evidence that differential participation influenced the validity of the study. Differential attrition may have biased behavioral measures of intervention effectiveness, but not necessarily measures of condom use effectiveness.     

An updated study of mortality among North American synthetic rubber industry workers

Aim: This study evaluated the mortality experience of workers from the styrene-butadiene industry. Methods: The authors added seven years of follow up to a previous investigation of mortality among 17 924 men employed in the North American synthetic rubber industry. Analyses used the standardised mortality ratios (SMRs) to compare styrene-butadiene rubber workers'' cause specific mortality (1943–98) with those of the United States and the Ontario general populations. Results: Overall, the observed/expected numbers of deaths were 6237/7242 for all causes (SMR = 86, 95% CI 84 to 88) and 1608/1741 for all cancers combined (SMR = 92, 95% CI 88 to 97), 71/61 for leukaemia, 53/53 for non-Hodgkin''s lymphoma, and 26/27 for multiple myeloma. The 16% leukaemia increase was concentrated in hourly paid subjects with 20–29 years since hire and 10 or more years of employment in the industry (19/7.4, SMR = 258, 95% CI 156 to 403) and in subjects employed in polymerisation (18/8.8, SMR = 204, 95% CI 121 to 322), maintenance labour (15/7.4, SMR = 326, 95% CI 178 to 456), and laboratory operations (14/4.3, SMR = 326, 95% CI 178–546). Conclusion: The study found that some subgroups of synthetic rubber workers had an excess of mortality from leukaemia that was not limited to a particular form of leukaemia. Uncertainty remains about the specific agent(s) that might be responsible for the observed excesses and about the role of unidentified confounding factors. The study did not find any clear relation between employment in the industry and other forms of lymphohaematopoietic cancer. Some subgroups of subjects had more than expected deaths from colorectal and prostate cancers. These increases did not appear to be related to occupational exposure in the industry.     

Homocysteinemia is Associated with a Lower Degree of PBMC LINE-1 Methylation and a Higher Risk of CIN 2C in the U.S. Post-Folic Acid Fortification Era

The primary aim of the study was to determine whether plasma concentrations of homocysteine (Hcy), a functional indicator of methyl donor nutrients, are associated with altered risk of higher grades of cervical intraepithelial neoplasia (CIN 2+) and the degree of methylation in long interspersed nucleotide elements (LINE-1s) of peripheral blood mononuclear cells, a potential biomarker of CIN 2+ in a population of women exposed to the United States folic acid fortification program. The secondary aim was to assess the determinants of plasma Hcy in the same population. The study included 457 women diagnosed with either CIN 2+ (cases, n = 132) or ≤ CIN 1 (non-cases, n = 325). Unconditional logistic regression models were used to test the associations after adjusting for relevant risk factors of cervical cancer. Women with higher Hcy concentrations were at a greater risk of being diagnosed with CIN 2+ [odds ratio (OR) = 1.86, P = 0.005]. Higher plasma folate concentrations were a significant determinant of lower Hcy (OR = 0.40, P = 0.0002). Women with higher Hcy concentrations were more likely to have a lower degree of LINE-1 methylation (OR = 2.30, P = 0.0007). These results suggested that further improvement in folate status in this population may be beneficial for lowering Hcy and improving the degree of LINE-1 methylation.     

用混合粘合剂碳糊电极测定丁螺环酮

用混合粘合剂碳糊电极测定丁螺环酮张正奇，曾鸽鸣，刘传桂，黎艳飞（湖南大学化学化工系，长沙４１００８２）碳糊电极无毒，制作方便，表面更新容易，应用电位范围广，在药物分析中已有应用［１～５］。我们在液体石腊中加入添加剂，组成混合粘合剂，可显著改善电极的检...