Assessing the interruption of the transmission of human helminths with mass drug administration alone: optimizing the design of cluster randomized trials

BACKGROUND

A method is outlined for the use of an individual-based stochastic model of parasite transmission dynamics to assess different designs for a cluster randomized trial in which mass drug administration (MDA) is employed in attempts to eliminate the transmission of soil-transmitted helminths (STH) in defined geographic locations. The hypothesis to be tested is: Can MDA alone interrupt the transmission of STH species in defined settings? Clustering is at a village level and the choice of clusters of villages is stratified by transmission intensity (low, medium and high) and parasite species mix (either Ascaris, Trichuris or hookworm dominant).

RESULTS

The methodological approach first uses an age-structured deterministic model to predict the MDA coverage required for treating pre-school aged children (Pre-SAC), school aged children (SAC) and adults (Adults) to eliminate transmission (crossing the breakpoint in transmission created by sexual mating in dioecious helminths) with 3 rounds of annual MDA. Stochastic individual-based models are then used to calculate the positive and negative predictive values (PPV and NPV, respectively, for observing elimination or the bounce back of infection) for a defined prevalence of infection 2 years post the cessation of MDA. For the arm only involving the treatment of Pre-SAC and SAC, the failure rate is predicted to be very high (particularly for hookworm-infected villages) unless transmission intensity is very low (R0, or the effective reproductive number R, just above unity in value).

CONCLUSIONS

The calculations are designed to consider various trial arms and stratifications; namely, community-based treatment and Pre-SAC and SAC only treatment (the two arms of the trial), different STH transmission settings of low, medium and high, and different STH species mixes. Results are considered in the light of the complications introduced by the choice of statistic to define success or failure, varying adherence to treatment, migration and parameter uncertainty.

Employers' Viewpoint on Clinical Education

ISSUE

This qualitative study gathered the opinions of healthcare employers to better understand the importance, benefits, obstacles, and evolving issues related to allied health (AH) clinical education from the employers' perspective, with the goal to identify opportunities to strengthen and improve clinical-educational partnerships.

METHOD

Member deans of the Association of Schools of Allied Health Professions (ASAHP) provided names and contact information of employers that routinely educate their students. Interviews were scheduled with employers who responded to Clinical Education Task Force (CETF) invitation. Twenty-one interviews were conducted by CETF members in early 2016 and analyzed utilizing qualitative software.

OUTCOMES

Themes included benefits of working with students and hiring trainees, and obstacles of time and effort required to host students. A trend was noted in gaps between educational preparation and clinical performance. Recent changes highlighted increased technology and regulation, while anticipated changes included more focus on learning on site, longer clinical experiences, and payment for clinical education.

CONCLUSION

Collaboration between educators and employers is essential to ensure that curriculum and outcomes match the needs of the field and effectively prepare students as entry-level clinicians.

Identifying Competency Indicators of Teachers of the Severely Handicapped

This article describes a research effort designed to identify indicators of competencies of teachers of the severely handicapped. Two indicators of competency (amount of instruction time, percentage of curriculum materials task analyzed) were identified as contributing to 78% of the variance for all variables. A training model was described for teaching these competencies to teachers, and subsequent student performance data were reported which demonstrate that the students of teachers trained under this model perform significantly better than students of teachers not trained. The implications of this study for teacher-training institutions are also addressed.

Identification of the free and conjugated sterol in a non-photosynthetic diatom,Nitzschia alba, as 24-methylene cholesterol

Previous studies on the sterol fraction of the nonphotosynthetic marine diatom,Nitszchia alba, indicated the major sterol to be either brassicasterol (24R-methylcholesta-5,22-dien-3β-ol) or 22-dehydrocampesterol (24S-methylcholesta-5,22-dien-3β-ol) on the basis only of gas chromatographymass spectral analysis. The present studies using nuclear magnetic resonance, infrared, and gas chromatography-mass spectrometry on the free and bound sterol fractions isolated by preparative thin layer chromatography showed the presence in both fractions of a single sterol, with spectral and chromatographic properties identical with those reported for 24-methylenecholesterol (ergosta-5,24(28)-dien-3β-ol). This sterol may be the precursor of 24-methyl sterols found in diatoms. The bound sterol fraction was found to consist of a single compound identified as 24-methylenecholesterol sulfate. No sterol esters or sterol glycosides were detected.

Expressive visual text-to-speech as an assistive technology for individuals with autism spectrum conditions

Adults with Autism Spectrum Conditions (ASC) experience marked difficulties in recognising the emotions of others and responding appropriately. The clinical characteristics of ASC mean that face to face or group interventions may not be appropriate for this clinical group. This article explores the potential of a new interactive technology, converting text to emotionally expressive speech, to improve emotion processing ability and attention to faces in adults with ASC. We demonstrate a method for generating a near-videorealistic avatar (XpressiveTalk), which can produce a video of a face uttering inputted text, in a large variety of emotional tones. We then demonstrate that general population adults can correctly recognize the emotions portrayed by XpressiveTalk. Adults with ASC are significantly less accurate than controls, but still above chance levels for inferring emotions from XpressiveTalk. Both groups are significantly more accurate when inferring sad emotions from XpressiveTalk compared to the original actress, and rate these expressions as significantly more preferred and realistic. The potential applications for XpressiveTalk as an assistive technology for adults with ASC is discussed.

Pneumolysin activates neutrophil extracellular trap formation

The primary objective of the current study was to investigate the potential of the pneumococcal toxin, pneumolysin (Ply), to activate neutrophil extracellular trap (NET) formation in vitro. Isolated human blood neutrophils were exposed to recombinant Ply (5-20 ng ml(-1) ) for 30-90 min at 37°C and NET formation measured using the following procedures to detect extracellular DNA: (i) flow cytometry using Vybrant® DyeCycle™ Ruby; (ii) spectrofluorimetry using the fluorophore, Sytox(®) Orange (5 μM); and (iii) NanoDrop(®) technology. These procedures were complemented by fluorescence microscopy using 4', 6-diamino-2-phenylindole (DAPI) (nuclear stain) in combination with anti-citrullinated histone monoclonal antibodies to visualize nets. Exposure of neutrophils to Ply resulted in relatively rapid (detected within 30-60 min), statistically significant (P < 0·05) dose- and time-related increases in the release of cellular DNA impregnated with both citrullinated histone and myeloperoxidase. Microscopy revealed that NETosis appeared to be restricted to a subpopulation of neutrophils, the numbers of NET-forming cells in the control and Ply-treated systems (10 and 20 ng ml(-1) ) were 4·3 (4·2), 14.3 (9·9) and 16·5 (7·5), respectively (n = 4, P < 0·0001 for comparison of the control with both Ply-treated systems). Ply-induced NETosis occurred in the setting of retention of cell viability, and apparent lack of involvement of reactive oxygen species and Toll-like receptor 4. In conclusion, Ply induces vital NETosis in human neutrophils, a process which may either contribute to host defence or worsen disease severity, depending on the intensity of the inflammatory response during pneumococcal infection.

Highly Compliant Vascular Grafts with Gelatin-Sheathed Coaxially Structured Nanofibers

We have developed three types of materials composed of polyurethane-gelatin, polycaprolactone-gelatin, or polylactic acid-gelatin nanofibers by coaxially electrospinning the hydrophobic core and gelatin sheath with a ratio of 1:5 at fixed concentrations. Results from attenuated total reflection-Fourier transformed infrared spectroscopy demonstrated the gelatin coating around nanofibers in all of the materials. Transmission electron microscopy images further displayed the core-sheath structures showing the core-to-sheath thickness ratio varied greatly with the highest ratio found in polyurethane-gelatin nanofibers. Scanning electron microscopy images revealed similar, uniform fibrous structures in all of the materials, which changed with genipin cross-linking due to interfiber interactions. Thermal analyses revealed varied interactions between the hydrophilic sheath and hydrophobic core among the three materials, which likely caused different core-sheath structures, and thus physicomechanical properties. The addition of gelatin around the hydrophobic polymer and their interactions led to the formation of graft scaffolds with tissue-like viscoelasticity, high compliance, excellent swelling capability, and absence of water permeability while maintaining competent tensile modulus, burst pressure, and suture retention. The hydrogel-like characteristics are advantageous for vascular grafting use, because of the capability of bypassing preclotting prior to implantation, retaining vascular fluid volume, and facilitating molecular transport across the graft wall, as shown by coculturing vascular cells sandwiched over a thick-wall scaffold. Varied core-sheath interactions within scaffolding nanofibers led to differences in graft functional properties such as water swelling ratio, compliance, and supporting growth of cocultured vascular cells. The PCL-gelatin scaffold with thick gelatin-sheathed nanofibers demonstrated a more compliant structure, elastic mechanics, and high water swelling property. Our results demonstrate a feasible approach to produce new hybrid, biodegradable nanofibrous scaffold biomaterials with interactive core-sheath structure, good biocompatibility, and tissue-like viscoelasticity, which may reduce potential problems with the use of individual polymers for vascular grafts.

Implementing health promotion programmes in schools: a realist systematic review of research and experience in the United Kingdom

Background

Schools have long been viewed as a good setting in which to encourage healthy lifestyles amongst children, and schools in many countries aspire to more comprehensive, integrated approaches to health promotion. Recent reviews have identified evidence of the effects of school health promotion on children’s and young people’s health. However, understanding of how such programmes can be implemented in schools is more limited.

Methods

We conducted a realist review to identify the conditions and actions which lead to the successful implementation of health promotion programmes in schools. We used the international literature to develop programme theories which were then tested using evaluations of school health promotion programmes conducted in the United Kingdom (UK). Iterative searching and screening was conducted to identify sources and clear criteria applied for appraisal of included sources. A review advisory group comprising educational and public health practitioners, commissioners, and academics was established at the outset.

Results

In consultation with the review advisory group, we developed four programme theories (preparing for implementation, initial implementation, embedding into routine practice, adaptation and evolution); these were then refined using the UK evaluations in the review. This enabled us to identify transferable mechanisms and enabling and constraining contexts and investigate how the operation of mechanisms differed in different contexts. We also identified steps that should be taken at a senior level in relation to preparing for implementation (which revolved around negotiation about programme delivery) and initial implementation (which centred on facilitation, support, and reciprocity—the latter for both programme deliverers and pupils). However, the depth and rigour of evidence concerning embedding into routine practice and adaptation and evolution was limited.

Conclusions

Our findings provide guidance for the design, implementation, and evaluation of health promotion in schools and identify the areas where further research is needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s13012-015-0338-6) contains supplementary material, which is available to authorized users.