Integration, effectiveness and costs of different models of primary health care provision for people who are homeless: an evaluation study.

Background: There is a high prevalence of health problems among single people who are homeless. Specialist primary health care services for this population have been developed in several locations across England; however, there have been very few evaluations of these services. Objectives: This study evaluated the work of different models of primary health care provision in England to determine their effectiveness in engaging people who are homeless in health care and in providing continuity of care for long-term conditions. It concerned single people (not families or couples with dependent children) staying in hostels, other temporary accommodation or on the streets. The influence on outcomes of contextual factors and mechanisms (service delivery factors), including integration with other services, were examined. Data from medical records were collated on participants' use of health care and social care services over 12 months, and costs were calculated. Design and setting: The evaluation involved four existing Health Service Models: (1) health centres primarily for people who are homeless (Dedicated Centres), (2) Mobile Teams providing health care in hostels and day centres, (3) Specialist GPs providing some services exclusively for patients who are homeless and (4) Usual Care GPs providing no special services for people who are homeless (as a comparison). Two Case Study Sites were recruited for each of the specialist models, and four for the Usual Care GP model. Participants: People who had been homeless during the previous 12 months were recruited as 'case study participants'; they were interviewed at baseline and at 4 and 8 months, and information was collected about their circumstances and their health and service use in the preceding 4 months. Overall, 363 participants were recruited; medical records were obtained for 349 participants. Interviews were conducted with 65 Case Study Site staff and sessional workers, and 81 service providers and stakeholders. Results: The primary outcome was the extent of health screening for body mass index, mental health, alcohol use, tuberculosis, smoking and hepatitis A among participants, and evidence of an intervention if a problem was identified. There were no overall differences in screening between the models apart from Mobile Teams, which scored considerably lower. Dedicated Centres and Specialist GPs were more successful in providing continuity of care for participants with depression and alcohol and drug problems. Service use and costs were significantly higher for Dedicated Centre participants and lower for Usual Care GP participants. Participants and staff welcomed flexible and tailored approaches to care, and related services being available in the same building. Across all models, dental needs were unaddressed and staff reported poor availability of mental health services. Limitations: There were difficulties recruiting mainstream general practices for the Usual Care GP model. Medical records could not be accessed for 14 participants of this model. Conclusions: Participant characteristics, contextual factors and mechanisms were influential in determining outcomes. Overall, outcomes for Dedicated Centres and for one of the Specialist GP sites were relatively favourable. They had dedicated staff for patients who were homeless, 'drop-in' services, on-site mental health and substance misuse services, and worked closely with hospitals and homelessness sector services. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (HSDR 13/156/03) and will be published in full in Health and Social Care Delivery Research; Vol. 11, No. 16. See the NIHR Journals Library website for further project information.

Health problems are common among single people who are homeless, but there is little evidence of the best ways to deliver primary health care to them. This study evaluated four types of services (models) that are in existence: (1) health centres primarily for people who are homeless (Dedicated Centres); (2) Mobile Teams that provide health care in hostels and day centres; (3) Specialist GPs that have some services exclusively for patients who are homeless; and (4) Usual Care GPs providing health care to all patients, with no special services for people who are homeless. The study concentrated on single people (not homeless families or couples with dependent children) staying in hostels, other temporary accommodation and on the streets. Overall, 363 patients at these practices who had been homeless in the previous 12 months participated, and information was collected from them over a 12-month period. We examined the extent to which screening for different health conditions was undertaken, and to which treatment and follow-up care were provided for participants with chronic respiratory problems, depression, alcohol problems and drug problems. Information was gathered from their medical records about use of health and social care services over 12 months. Overall, outcomes for Dedicated Centres and for one of the Specialist GP sites were more favourable. They had staff working specifically with patients who were homeless; provided flexible 'drop-in' services instead of requiring patients to book appointments; and worked closely with mental health, alcohol and drug services, and with hostels, day centres and street outreach teams. Participants were also more satisfied with the health care they received from the specialist models, and were more likely to say that they had confidence and trust in doctors and nurses at these sites. Across all models, dental needs were unaddressed and staff reported poor availability of mental health services.

How do people who use drugs experience treatment? A qualitative analysis of views about opioid substitution treatment in primary care (iCARE study).

OBJECTIVE: To understand the most significant aspects of care experienced by people in opioid substitution treatment (OST) in primary care settings. DESIGN: Semistructured individual interviews were conducted, following the critical incidents technique. Interview transcripts were analysed following a thematic analysis approach. PARTICIPANTS: Adults aged 18 years or older, receiving OST in UK-based primary care services. RESULTS: Twenty-four people in OST were interviewed between January and March 2019. Participants reported several aspects which were significant for their treatment, when engaging with the primary care service. These were grouped into 10 major themes: (1) humanised care; (2) individual bond/connection with the professional; (3) professionals' experience and knowledge; (4) having holistic care; (5) familiarity; (6) professionals' commitment and availability to help; (7) anonymity; (8) location; (9) collaborative teamwork; and (10) flexibility and changes around the treatment plan. CONCLUSIONS: This study included first-hand accounts of people who use drugs about what supports them in their recovery journey. The key lessons learnt from our findings indicate that people who use drugs value receiving treatment in humanised and destigmatised environments. We also learnt that a good relationship with primary care professionals supports their recovery journey, and that treatment plans should be flexible, tailor-made and collaboratively designed with patients.

Rifampin Resistance Mutations Are Associated with Broad Chemical Remodeling of Mycobacterium tuberculosis.

Global control of tuberculosis has become increasingly complicated with the emergence of multidrug-resistant strains of Mycobacterium tuberculosis First-line treatments are anchored by two antibiotics, rifampin and isoniazid. Most rifampin resistance occurs through the acquisition of missense mutations in the rifampin resistance-determining region, an 81-base pair region encoding the rifampin binding site on the ß subunit of RNA polymerase (rpoB). Although these mutations confer a survival advantage in the presence of rifampin, they may alter the normal process of transcription, thereby imposing significant fitness costs. Because the downstream biochemical consequences of the rpoB mutations are unknown, we used an organism-wide screen to identify the number and types of lipids changed after rpoB mutation. A new mass spectrometry-based profiling platform systematically compared ∼10,000 cell wall lipids in a panel of rifampin-resistant mutants within two genetically distinct strains, CDC1551and W-Beijing. This unbiased lipidomic survey detected quantitative alterations (>2-fold, p < 0.05) in more than 100 lipids in each mutant. By focusing on molecular events that change among most mutants and in both genetic backgrounds, we found that rifampin resistance mutations lead to altered concentrations of mycobactin siderophores and acylated sulfoglycolipids. These findings validate a new organism-wide lipidomic analysis platform for drug-resistant mycobacteria and provide direct evidence for characteristic remodeling of cell wall lipids in rifampin-resistant strains of M. tuberculosis The specific links between rifampin resistance and named lipid factors provide diagnostic and therapeutic targets that may be exploited to address the problem of drug resistance.

Pull-out strength comparison of a novel expanding fastener against an orthopaedic screw in an ovine vertebral body: an ex-vivo study.

The purpose of this study was to mechanically test a novel Unthreaded Expandable Fastener (UEF), manufactured using Selective Laser Melting, which was designed for fixation in the cervical lateral mass. The pull-out strength and stiffness of the prototype UEFs was evaluated in a non-osteoporotic ovine bone model against equivalent screws. The prototype UEF demonstrated a 41% increase in failure force and a 60% reduction in failure force standard deviation compared to the screws. All bone samples were micro CT-scanned and no significant differences in bone microstructural properties was found between the screw and UEF sample sets, indicating that the UEFs may be less sensitive to bone quality variation. This increased performance can potentially translate into improved surgical outcome and reduced surgical risk for lateral mass fixation. With further design optimisation, additional improvement in performance over screws may be possible in future studies.

Analysis of mechanical contrast in optical coherence elastography.

Optical coherence elastography (OCE) maps the mechanical properties of tissue microstructure and has potential applications in both fundamental investigations of biomechanics and clinical medicine. We report the first analysis of contrast in OCE, including evaluation of the accuracy with which OCE images (elastograms) represent mechanical properties and the sensitivity of OCE to mechanical contrast within a sample. Using phase-sensitive compression OCE, we generate elastograms of tissue-mimicking phantoms with known mechanical properties and identify limitations on contrast imposed by sample mechanics and the imaging system, including signal-processing parameters. We also generate simulated elastograms using finite element models to perform mechanical analysis in the absence of imaging system noise. In both experiments and simulations, we illustrate artifacts that degrade elastogram accuracy, depending on sample geometry, elasticity contrast between features, and surface conditions. We experimentally demonstrate sensitivity to features with elasticity contrast as small as 1.1∶1 and calculate, based on our imaging system parameters, a theoretical maximum sensitivity to elasticity contrast of 1.002∶1. The results highlight the microstrain sensitivity of compression OCE, at a spatial resolution of tens of micrometers, suggesting its potential for the detection of minute changes in elasticity within heterogeneous tissue.

Mycobacterium tuberculosis--heterogeneity revealed through whole genome sequencing.

The emergence of whole genome sequencing (WGS) technologies as primary research tools has allowed for the detection of genetic diversity in Mycobacterium tuberculosis (Mtb) with unprecedented resolution. WGS has been used to address a broad range of topics, including the dynamics of evolution, transmission and treatment. Here, we have analyzed 55 publically available genomes to reconstruct the phylogeny of Mtb, and we have addressed complications that arise during the analysis of publically available WGS data. Additionally, we have reviewed the application of WGS to the study of Mtb and discuss those areas still to be addressed, moving from global (phylogeography), to local (transmission chains and circulating strain diversity), to the single patient (clonal heterogeneity) and to the bacterium itself (evolutionary studies). Finally, we discuss the current WGS approaches, their strengths and limitations.

Fracture susceptibility of worn teeth.

An experimental simulation study is made to determine the effects of occlusal wear on the capacity of teeth to resist fracture. Tests are carried out on model dome structures, using glass shells to represent enamel and epoxy filler to represent dentin. The top of the domes are ground and polished to produce flat surfaces of prescribed depths relative to shell thickness. The worn surfaces are then loaded axially with a hard sphere, or a hard or soft flat indenter, to represent extremes of food contacts. The loads required to drive longitudinal cracks around the side walls of the enamel to failure are measured as a function of relative wear depth. It is shown that increased wear can inhibit or enhance load-bearing capacity, depending on the nature of the contact. The results are discussed in the context of biological evolutionary pressures.

'Talking of Sex': developing and piloting a sexual health communication tool for use in primary care.

OBJECTIVE: To develop and pilot a communication aid aimed at increasing the frequency with which sexual health issues are raised proactively with young people in primary care. METHODS: Group interviews among primary health care professionals to guide development of the tool, simulated consultations to pre-test it, and a pilot study to assess effectiveness. RESULTS: We developed an electronic consultation aid: Talking of Sex and piloted it in eight general practices across the UK. 188 patients and 58 practitioners completed questionnaires pre-intervention, and 92 patients and 45 practitioners post-intervention. There was a modest increase in the proportion of consultations in which sexual health was raised, from 28.1% pre-intervention to 32.6% post-intervention. In consultations with nurses the rise was more marked. More patients reported discussing preventive practices such as condom use post-intervention. Patients unanimously welcomed the opportunity to discuss sexual health matters with their practitioner. CONCLUSION: The tool has capacity to increase the frequency with which sexual health is raised in primary care, particularly by nurses, to influence the topics discussed, and to improve patient satisfaction. PRACTICE IMPLICATIONS: The tool has potential in increasing the proportion of young people whose sexual health needs are addressed in general practice.

Communication between female tract and sperm: Saying NO* when you mean yes.

Signaling through [Ca(2+)](i) is central to regulation of sperm activity and is likely to be the mechanism that transduces signals from the female reproductive tract to regulate sperm motility. In a recent paper1 we showed that exposure of sperm to nitric oxide mobilizes stored Ca(2+) in human sperm, an effect that occurs through nitrosylation of protein thiols. Not only did we find that NO* production by cells of the human female tract would be sufficient to elicit this effect, but progesterone, which is also present in the female tract and is synthesized by the oocyte vestments, acted synergistically with NO* to mobilize Ca(2+) and enhance flagellar beating. Here we argue that a Ca(2+) store at the junction of the sperm head and flagellum is subject to regulation by both progesterone and NO* and that ryanodine receptors at the store may be the point at which coincidence detection and synergistic interaction occurs.

Effect of wear on stress distributions and potential fracture in teeth.

Finite element analysis is conducted on a tooth model with different degrees of wear. The model is taken as a hemispherical shell (enamel) on a compliant interior (dentin). Occlusal loading is simulated by contact with a flat or curved, hard or soft, indenter. Stress redistributions indicate that development of a wear facet may enhance some near-contact fracture modes (cone-ring cracks, radial-median cracks, edge-chipping), but have little effect on far-field modes (margin cracks). Contacts on worn surfaces with small, hard food objects are likely to be most deleterious, generating local stress concentrations and thereby accelerating the wear process. More typical contacts with larger-scale soft foods are unlikely to have such adverse effects. Implications concerning dietary habits of animals is an adjunct consideration in this work.

Margin failures in crown-like brittle structures: off-axis loading.

The effect of off-axis loading of compliant indenters on the initiation of cracks at the margins of dental crown-like dome structures consisting of glass shells back-filled with an epoxy resin is examined. As in previous studies on similar structures but with strictly axial loading, cracks can be made to initiate and propagate from the margins around the dome faces into a "semi-lunar" fracture pattern characteristic of some all-ceramic crown failures. In this study, balsa wood and teflon disk indenters are used to provide the off-axis loading, at 45 degrees to the dome axis. The soft indenters, considered representative of food bolus, spread the contact at the top surface, suppressing otherwise dominant radial cracks that ordinarily initiate at the dome undersurface directly along the load axis beneath harder indenters. Finite element modeling is used to show that off-axis loading dramatically increases the tensile stresses at the near-side dome margin, strongly diminishing the loads required to generate the lunar fracture mode.

The role of skirt geometry of dental crowns on the mechanics of failure: experimental and numerical study.

Dental crown structures were modelled using a curved bi-layer system consisting of a brittle glass coating on a compliant polymeric substrate, to illustrate the role of skirt geometry on the mechanics of failure evolution. The geometries of the samples were varied by tapering the skirts of the glass shells in different lengths and thicknesses. The failure of these samples was investigated under single-cycle axial loading tests using an indenter of low elastic modulus. The onset of fracture was observed in situ using a video camera. A relationship between the height and thickness of the taper and the critical load required for a crack to appear in the sample was observed. Margin cracks were observed to propagate from flaws near the margins. Experimental trends suggested that critical loads increased with increasing taper thickness, and decreased with increasing taper length. Finite element modelling was also used to evaluate the stress distribution in the glass coating. Peak maximum principal stresses at the margins decreased with increasing taper thickness, and increased with increasing taper length, consistent with the experimentally determined critical loads. It is concluded that long, narrow tapers should be avoided in order to maximise the load bearing capacity of dental crowns.

Genes involved in Sec-independent membrane targeting of hydrogenase in Azotobacter chroococcum.

Sec-independent translocation systems have been characterised in Escherichia coli and other bacteria and differ from the Sec-dependent system by transporting fully folded proteins using the transmembrane proton electrochemical gradient. Proteins transported by this system bear a twin-arginine motif (tat) in the N-terminal signal peptide and include several cofactor-containing proteins. Azotobacter chroococcum strain (MCD124) has a soluble hydrogenase, which exhibited low O(2)-dependent H(2) uptake, and a shift in the pH of the culture to a more alkaline range during growth. We show that the DNA region capable of complementing this strain contains the tatABC genes and that mutations in the tatA gene reproduced the soluble hydrogenase and the culture pH shift phenotypes. We also show that insertional mutation in the tatC gene at a position corresponding to its C-terminal region had no effect on hydrogenase activity, but induced the pH shift of the culture. Sequence and mutagenesis analyses of this genomic region suggest that these genes form an operon that does not contain a tatD-like gene. A mutation in hupZ of the main hup gene region, coding for a possible b-type cytochrome also yielded a soluble hydrogenase, but not the pH-shift phenotype.

Margin failures in brittle dome structures: relevance to failure of dental crowns.

Margin cracks in loaded brittle dome structures are investigated. Dome structures consisting of glass shells filled with polymer resin, simulating the essential features of brittle crowns on tooth dentin, provide model test specimens. Disk indenters of diminishing elastic modulus are used to apply axisymmetric loading to the apex of the domes. Previous studies using hard indenters have focused on fractures initiating in the near-contact region of such specimens, including radial cracks at the glass undersurface directly below the contact axis. Here, we focus on fractures initiating at the remote support margins. Margin cracks can become dominant when loading forces are distributed over broad contact areas, as in biting on soft matter, here simulated by balsa wood disks. Cracks preinitiated at the dome edges during the specimen preparation propagate under load around the dome side into segmented, semilunar configurations reminiscent of some all-ceramic crown failures. Finite element analysis is used to determine the basic stress states within the dome structures, and to confirm a shift in maximum tensile stress from the near-contact area to the dome sides with more compliant indenters.