对接触系统的再认识

目前人们已认识到接触系统在启动体内凝血方面所起的作用微乎其微，而接触系统蛋白的缺乏却可能是血栓形成的危险因素。研究表明活化的因子Ⅻ(FⅫa)和活化的因子Ⅺ(FⅪa)可裂解纤溶酶原；激肽释放酶能将前尿激酶活化为双链结构的尿激酶；高分子量激肽原和低分子量激肽原能选择性抑制凝血酶诱导的血小板活化；高分子量激肽原可通过置换粘附蛋白抑制细胞粘附，可通过抑制内皮细胞的迁移和增殖抑制血管新生；内毒素可激活接触系统，高分子量激肽原的下降和α2巨球蛋白．激肽释放酶复合物的上升与不可逆低血压的发生显著相关。总之，接触系统在促进纤维蛋白溶解、抗血栓、抗粘附、抑制新生血管形成、介导炎症反应等病理生理方面起着重要作用。     

Basophil histamine release and lymphocyte proliferation tests in latex contact urticaria

Basophil histamine release and lymphocyte proliferation tests were examined with latex allergen prepared from surgical gloves in 15 patients with latex contact urticaria. The basophil histamine release test (BHRT) yielded positive results in 13/14 (93%) patients, whereas commercial latex RAST was positive in only 9/15 (60%) patients. Lymphocyte proliferation test (LPT) was positive in 3/15 (20%) patients, suggesting that cell-mediated immune reactions may also occur in latex allergy. However, patch tests to latex were negative and neither were epidermal Langerhans cells able to present latex antigen to T lymphocytes in vitro.     

Another Look at the Relationship of Electrodermal Activity to Electrode Contact Area

The present study was undertaken lo reexamine the hypothesis that the relationship between skin conductance and electrode size is monotonic and linear. Skin conductance activity was recorded from 48 right-handed male subjects using 6 different sixes of electrode collars ranging in exposed surface area from .131 cm² to .786 cm². The dependent measures were skin conductance level (SCL); skin conductance response (SCR) amplitude to a series of 8 loud tones; latency, rise time, and recovery half-time of the first tone elicited response; (he largest self-generated SCR; and the number of nonspecific responses. The results indicated a significant linear relationship between contact area and SCL, stimulus and self-generated SCR amplitude, and the number of nonspecific responses. Latency was not affected by electrode size although the other time-based measures were. Differences in skin conductance activity were found among different palmar recording sites. The observed linear relationship between electrode size and electrodermal measures has implications for current models of electrodermal activity and for the comparison of results across studies in which different electrode contact areas are used.     

Specular microscopy of hard contact lens wearers

Wide-field specular microscopy, slit-lamp examination, and pachometry were performed on 22 successful hard contact lens wearers and 22 controls matched for age, race, sex, and refractive error. A minimum of 600 cells per control and 1200 per contact lens wearer were manually digitized from the specular photomicrographs. Frequency distributions of cell areas were compared between the two groups using the parameters of mean, median, standard deviation, coefficient of variation, skewness and kurtosis. Slit-lamp examination was normal and there was no significant difference in corneal thickness between the patient group and the control group. Comparison of mean, median, and standard deviation also revealed no significant difference, but skewness (P less than .001), kurtosis (P less than .001) and coefficient of variation (P less than .004) were greater in the hard contact lens wear group. Hard contact lens wearing time correlated with increasing pleomorphism (P less than .05). Specular microscopy also revealed morphologic changes including deep stromal striae, intra- and extracellular "blackout" areas, and clustering of extremely small and large cells. The possible relationship between endothelial hypoxia and structural stromal changes are discussed.     

Sleep Problems among Mothers of Youth Stopped by the Police

Police stops are the most common form of criminal justice exposure in the USA, and are particularly common among urban youth, with 23% of them reporting a stop by the age of 15. While recent work has begun to illuminate the health impacts of police stops for these youth, little is known about the health consequences of youth police contact for the mothers of youth stopped by the police. The current study employs data from the Fragile Families and Child Wellbeing Study (FFCWS), a sample of urban, at-risk youth and their families. Multivariate logistic regression models are conducted to examine the link between youth police stops and sleep difficulties among mothers. Additional analyses examine whether the features and consequences of police stops are associated with sleep difficulties among mothers. The findings indicate that mothers with youth who have experienced police stops are more than twice as likely to report both depression- and anxiety-related sleep difficulties compared to their counterparts. Furthermore, stops with certain features—including those characterized by intrusiveness, high trauma, and high stigma—emerged as consistently significant predictors of maternal sleep difficulties. The findings suggest that mothers who are vicariously exposed to police contact via their children are a vulnerable group. Given the non-random distribution of police contact across the population of youth, with police contact concentrated among children of color, the findings suggest that police contact may exacerbate racial inequalities in sleep, which may itself contribute to racial disparities in broader mental and physical health outcomes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11524-021-00518-1.     

Effectiveness of Preventive Therapy for Persons Exposed at Home to Drug-Resistant Tuberculosis,Karachi, Pakistan

In Karachi, Pakistan, a South Asian megacity with a high prevalence of tuberculosis (TB) and low HIV prevalence, we assessed the effectiveness of fluoroquinolone-based preventive therapy for drug-resistant (DR) TB exposure. During February 2016–March 2017, high-risk household contacts of DR TB patients began a 6-month course of preventive therapy with a fluoroquinolone-based, 2-drug regimen. We assessed effectiveness in this cohort by comparing the rate and risk for TB disease over 2 years to the rates and risks reported in the literature. Of 172 participants, TB occurred in 2 persons over 336 person-years of observation. TB disease incidence rate observed in the cohort was 6.0/1,000 person-years. The incidence rate ratio ranged from 0.29 (95% CI 0.04–1.3) to 0.50 (95% CI 0.06–2.8), with a pooled estimate of 0.35 (95% CI 0.14–0.87). Overall, fluoroquinolone-based preventive therapy for DR TB exposure reduced risk for TB disease by 65%.     

Sexual Contact as Risk Factor for Campylobacter Infection,Denmark

Campylobacteriosis is a disease of worldwide importance, but aspects of its transmission dynamics, particularly risk factors, are still poorly understood. We used data from a matched case-control study of 4,269 men who have sex with men (MSM) and 26,215 controls, combined with national surveillance data on Campylobacter spp., Salmonella spp., and Shigella spp., to calculate matched odds ratios (mORs) for infection among MSM and controls. MSM had higher odds of Campylobacter (mOR 14, 95% CI 10–21) and Shigella (mOR 74, 95% CI 27–203) infections, but not Salmonella (mOR 0.2, 95% CI 0–13), and were less likely than controls to have acquired Campylobacter infection abroad (χ² = 21; p<0.001). Our results confirm that sexual contact is a risk factor for campylobacteriosis and also suggest explanations for unique features of Campylobacter epidemiology. These findings provide a baseline for updating infection risk guidelines to the general population.