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.     

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.     

Cerebral vessel laminins and IFN-gamma define Trypanosoma brucei brucei penetration of the blood-brain barrier

Subspecies of Trypanosoma brucei cause severe brain diseases after penetration of the blood-brain barrier. We investigated whether cytokines that modulate inflammatory cell infiltration into the brain also influence T. brucei neuroinvasion. Migration of a rodent pathogenic T. brucei strain from the cerebral blood vessels into the brain parenchyma was impeded in IFN-gamma(-/-), IFN-gamma receptor(-/-) (IFN-gammaR(-/-)), IL-12p40(-/-), and recombinant activating gene-1(-/-) (RAG-1(-/-)) mice as compared with their WT littermates despite higher levels of parasitemia in the mutant strains. Parasites accumulated in the perivascular compartment, confined between the endothelial and the parenchymal basement membranes, in certain areas of the brains of IFN-gamma(-/-), IFN-gammaR(-/-), and RAG-1(-/-) mice. This accumulation occurred around endothelial basement membranes containing the laminin alpha4 chain, while blood vessels showing robust laminin alpha5 chain immunostaining were not associated with parasite infiltration. The number of CD4+ and CD8+ T cells infiltrating the brain parenchyma was also reduced in the IFN-gamma(-/-) and IFN-gammaR(-/-) mice. Our findings suggest that lymphocyte-derived IFN-gamma facilitates trypanosome penetration across cerebral blood vessels and that the site of penetration is determined by the composition of the basement membranes of these vessels.     

Implementation of a prospective pregnancy registry for antiretroviral based HIV prevention trials

Background: Safety data on pregnancy and fetal outcomes among women in HIV prevention trials are urgently needed to inform use of effective antiretroviral agents for HIV prevention. We describe an effective, efficient, and novel method to prospectively collect perinatal safety data concurrent with on-going parent clinical trials.

Methods: The Microbicide Trials Network (MTN)-016 study is a multinational prospective pregnancy exposure registry designed to capture pregnancy and neonatal outcomes. Studies currently contributing data to this registry included phase I and II safety trials with planned exposures to candidate HIV prevention agents, as well as phase IIB and III efficacy trials capturing data on pregnancy and infant outcomes following inadvertent fetal exposure during study participation.

Results: To date, participants from two phase I studies and two effectiveness trials have participated in MTN-016, resulting in 420 pregnant women and 381 infants enrolled. Infant retention has been high, with 329 of 381 (86%) infants completing the 12-month follow-up visit.

Conclusion: In a research setting context, it is feasible to establish and implement a prospective, multinational HIV chemoprophylaxis pregnancy registry that will generate pregnancy exposure data in a robust fashion.     

Misreporting of contraceptive hormone use in clinical research participants

Objective

Researchers traditionally rely on participant self-report for contraceptive use. We hypothesized that self-reported contraceptive use by clinical research participants may disagree with objectively measured hormonal status.

Complex decisions: correlates of injectable contraceptive discontinuation following HIV-1 seroconversion in an HIV prevention trial

Contraceptive adherence during acute and recent HIV-1 infection is important to maternal and child health given the elevated risk of vertical HIV-1 transmission and additional complications of pregnancy. Injectable contraception (IC) is the most common non-barrier modern contraception method used in sub-Saharan Africa (SSA). Adherence to IC after HIV-1 seroconversion is not well understood. We examined factors associated with IC discontinuation among women in SSA diagnosed with HIV-1 infection while participating in a clinical trial of biomedical HIV-1 prevention. After diagnosis with HIV-1 infection in the VOICE trial, 255 women from South Africa, Uganda, and Zimbabwe enrolled in a longitudinal observational study (MTN-015). Contraceptive method was assessed at MTN-015 baseline and at 3, 12, and 24 months post-seroconversion. Correlates of IC discontinuation were examined by Cox proportional hazard modeling. IC use was reported at baseline by 78% of women enrolled (198/255), of which 92% (182/198) completed at least one follow-up visit. Two-thirds of women (66%, 121/182) continued on IC during the follow-up period (median 24 months). Lower rates of IC discontinuation were observed in women who reported having had at least one child (HR 0.39, 95% CI 0.20–0.82) or earning a personal income (HR 0.51, 95% CI 0.30–0.87) at baseline. These findings suggest that many women with HIV-1 infection face complex decision-making regarding family planning in the years that follow seroconversion and highlight that some women may discontinue IC use despite on-site provision of family planning services. Understanding the broader context of family planning choices in recently seroconverted women may be key to more effective linkages between family planning services and HIV-1 testing and care.     

Epidemiology of Serotype 1 Invasive Pneumococcal Disease,South Africa, 2003–2013

In South Africa, 7-valent pneumococcal conjugate vaccine (PCV) was introduced in April 2009 and replaced with 13-valent PCV in April 2011. We describe the epidemiology of serotype 1 Streptococcus pneumoniae disease during the pre- and post-PCV eras (2003–2013). Using laboratory-based invasive pneumococcal disease (IPD) surveillance, we calculated annual incidences, identified IPD clusters, and determined serotype 1–associated factors. Of 46,483 IPD cases, 4,544 (10%) were caused by serotype 1. Two clusters of serotype 1 infection were detected during 2003–2004 and 2008–2012, but incidence decreased after 2011. Among children <5 years of age, those who had non–serotype 1 IPD had shorter hospital stays, fewer cases of penicillin-nonsusceptible disease, and lower HIV prevalence and in-hospital death rates than did those with serotype 1 IPD; similar factors were noted for older patients. Serotype 1 IPD had distinctive clinical features in South Africa, and annual incidences fluctuated, with decreases noted after the introduction of PCV13.