A blood-borne antigen induces rapid T-B cell contact: a potential mechanism for tolerance induction

Understanding the difference between the development of a productive T‐cell response and tolerance is central to discerning how the immune system functions. Intravenous injection of soluble protein is thought to mimic the presentation of self‐serum and orally introduced antigens. It is generally toleragenic. The current view is that this outcome reflects the failure of ‘immunogenic’ dendritic cells to relocate to the T‐cell zone of the secondary lymphoid tissues. Here, using a peptide/I‐E^k tetramer and antibodies to stain splenic sections, we showed that antigen‐specific T cells were activated in the spleen within hours of injection or feeding of protein. The activated T cells were found to be located at the T–B junction, the bridging zone and the B‐cell area, interacting directly with B cells. In addition, B cells gain the ability to present antigen. Our results suggest a way for T cells to be stimulated by blood‐borne antigen presented by naïve B cells, a potential mechanism of tolerance induction.     

Knowledge and Attitudes About Pre-Exposure Prophylaxis Among Young Adults Experiencing Homelessness in Seven U.S. Cities

Purpose

Evidence suggests that young adults experiencing homelessness (YEH) are at elevated risk of HIV compared to housed youth. Given the limited research on pre-exposure prophylaxis (PrEP) awareness among YEH, this study examined their PrEP knowledge and attitudes.

Mechanistic pathways for the degradation of SMX drug and floatation of degraded products using F–Pt co-doped TiO2 photocatalysts

This work presents smart pathways to enhance the photocatalytic activity of TiO₂via co-doping with fluorine (F) and platinum (Pt) to form F–Pt co-doped TiO₂ photocatalysts and investigates the unique and unusual fluorination of the floated products. Our investigations indicate that the crystalline structure of the photocatalysts was a mixture of anatase and brookite phases and that the nanoparticles of the synthesized nanocomposites had nanometric sizes (4–25 nm). The F–Pt co-doped TiO₂ nano-photocatalysts demonstrated degradation of sulfamethoxazole (SMX) drug of >93% within 90 min under direct solar light and 58% degradation within 360 min under a solar simulator. Thus, co-doping TiO₂ with F and Pt atoms to form F–Pt co-doped TiO₂ nanocomposite is an efficient pathway to achieve high photocatalytic performance escorted with the formation of floating metal-fluoropolymer, unlike pristine TiO₂ which has less photocatalytic degradation and no generation of a floating polymer. Our photocatalytic protocol demonstrates that the degradation of SMX started with redox reactions of oxygen and water absorbed on the surface of the prepared nanocomposites to form superoxide anions (O₂˙⁻) and hydroxy radicals (˙OH) which have oxidation superpower. The resultant products were subsequently fluorinated by fluoride radical ions and floated as metal-fluoropolymer.

This work presents smart pathways to enhance the photocatalytic activity of TiO₂via co-doping with fluorine (F) and platinum (Pt) to form F–Pt co-doped TiO₂ photocatalysts and investigates the unique and unusual fluorination of the floated products.     

Imaging of pediatric thyroid tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Pediatric thyroid cancer is rare in children; however, incidence is increasing. Papillary thyroid cancer and follicular thyroid cancer are the most common subtypes, comprising about 90% and 10% of cases, respectively. This paper provides consensus imaging recommendations for evaluation of pediatric patients with thyroid cancer at diagnosis and during follow-up.     

社会、经济与环境因素对老年健康和死亡的影响——基于中国22省份的抽样调查

基于全国22省市886个县15 973位老人2002—2005年跟踪调查数据,本文应用多水平多元logit模型,对社会、经济和环境因素对老年健康和死亡的影响进行了分析。结果表明,控制了个人层面相关变量后,空气污染显著增加了老人ADL（日常生活自理能力）残障、认知功能差与累计健康亏损指数上升的可能性。降雨量的增加则显著降低了老人ADL残障和认知功能差的风险。极低的气温显著增加了老人ADL残障的风险与死亡风险,而极高的气温显著增加了老人认知功能差和累计健康亏损指数上升的可能性。居住在山区的老人ADL残障风险较低,累计健康亏损指数亦较低。此外,人均GDP、15～64岁人口的劳动参与率以及文盲率对中国老年人的生理健康、心理健康、整体健康水平以及死亡风险有显著的、作用方向不同的影响。最后,得出如下结论：保护自然环境、改善社会经济状况的干预措施将有利于改善老人健康、降低老人死亡风险。     

Adaptation and implementation of local maternity dashboards in a Zimbabwean hospital to drive clinical improvement

Problem

The Commission on Information and Accountability for Women''s and Children''s Health of the World Health Organization (WHO) reported that national health outcome data were often of questionable quality and “not timely enough for practical use by health planners and administrators”. Delayed reporting of poor-quality data limits the ability of front-line staff to identify problems rapidly and make improvements.

Approach

Clinical “dashboards” based on locally available data offer a way of providing accurate and timely information. A dashboard is a simple computerized tool that presents a health facility’s clinical data graphically using a traffic-light coding system to alert front-line staff about changes in the frequency of clinical outcomes. It provides rapid feedback on local outcomes in an accessible form and enables problems to be detected early. Until now, dashboards have been used only in high-resource settings.

Local setting

An overview maternity dashboard and a maternal mortality dashboard were designed for, and introduced at, a public hospital in Zimbabwe. A midwife at the hospital was trained to collect and input data monthly.

Relevant changes

Implementation of the maternity dashboards was feasible and 28 months of clinical outcome data were summarized using common computer software. Presentation of these data to staff led to the rapid identification of adverse trends in outcomes and to suggestions for actions to improve health-care quality.

Lessons learnt

Implementation of maternity dashboards was feasible in a low-resource setting and resulted in actions that improved health-care quality locally. Active participation of hospital management and midwifery staff was crucial to their success.     

Overlap syndrome of autoimmune chronic liver diseases: MRI findings

Purpose:

To describe the MR findings of overlap syndromes of autoimmune chronic liver diseases.

Methods:

Review of clinical and radiological databases between March 2001 and July 2008 for patients with a clinical diagnosis and liver biopsy features compatible with overlap syndrome who had also undergone an abdominal MRI yielded 15 adult patients. MR features of overlap syndrome were reviewed by two radiologists by consensus. Two radiologists independently reviewed the studies in a blinded fashion for primary sclerosing cholangitis (PSC)‐type or non‐PSC‐type features to assess interobserver agreement.

Results:

PSC‐type and non‐PSC‐type overlap syndrome had distinctive MR features. In the consensus review, all 12 patients with PSC‐type overlap syndrome were correctly identified. Imaging findings included central macroregeneration (N = 9), peripheral atrophy (N = 7), biliary duct beading (N = 12), biliary dilation (N = 10), or a combination of all four findings (N = 7). The presence of any of the first three features had 100% specificity for a PSC‐type overlap syndrome. Patients with non‐PSC‐type overlap (N = 3) showed relatively normal liver morphology (N = 3) and minimal biliary ductal dilatation in one patient. There was good interobserver agreement (kappa = 0.76).

Conclusion:

Patients with serologic or pathologic evidence of AIH or PBC with imaging features of PSC may have PSC‐type overlap syndrome. J. Magn. Reson. Imaging 2010; 31: 383–389. © 2010 Wiley‐Liss, Inc.     

Prevalence of cryptosporidiosis in Dammam and Alkhobar, Saudi Arabia

This report presents results from a 6-month study over the period 16 November 1986 to 15 May 1987 which was designed to investigate the prevalence of cryptosporidiosis in Dammam and Alkhobar, Saudi Arabia. A total of 209 stool specimens from children and 112 from adults with diarrhoea were examined. Only two (1%) of the children, both aged 2 years, were positive for Cryptosporidium spp. Giardia lamblia was found in 13 (4%) cases and was found to be the most common protozoan parasite, whereas Salmonella spp. was seen in 19 (6%) cases. Stool specimens were examined for rotavirus from children under 2 years of age; 31 (41%) of the specimens were positive.