Prkd1 regulates the formation and repair of plasma membrane disruptions (PMD) in osteocytes.

We and others have seen that osteocytes sense high-impact osteogenic mechanical loading via transient plasma membrane disruptions (PMDs) which initiate downstream mechanotransduction. However, a PMD must be repaired for the cell to survive this wounding event. Previous work suggested that the protein Prkd1 (also known as PKCµ) may be a critical component of this PMD repair process, but the specific role of Prkd1 in osteocyte mechanobiology had not yet been tested. We treated MLO-Y4 osteocytes with Prkd1 inhibitors (Go6976, kbNB 142-70, staurosporine) and generated an osteocyte-targeted (Dmp1-Cre) Prkd1 conditional knockout (CKO) mouse. PMD repair rate was measured via laser wounding and FM1-43 dye uptake, PMD formation and post-wounding survival were assessed via fluid flow shear stress (50 dyn/cm2), and in vitro osteocyte mechanotransduction was assessed via measurement of calcium signaling. To test the role of osteocyte Prkd1 in vivo, Prkd1 CKO and their wildtype (WT) littermates were subjected to 2 weeks of unilateral axial tibial loading and loading-induced changes in cortical bone mineral density, geometry, and formation were measured. Prkd1 inhibition or genetic deletion slowed osteocyte PMD repair rate and impaired post-wounding cell survival. These effects could largely be rescued by treating osteocytes with the FDA-approved synthetic copolymer Poloxamer 188 (P188), which was previously shown to facilitate membrane resealing and improve efficiency in the repair rate of PMD in skeletal muscle myocytes. In vivo, while both WT and Prkd1 CKO mice demonstrated anabolic responses to tibial loading, the magnitude of loading-induced increases in tibial BMD, cortical thickness, and periosteal mineralizing surface were blunted in Prkd1 CKO as compared to WT mice. Prkd1 CKO mice also tended to show a smaller relative difference in the number of osteocyte PMD in loaded limbs and showed greater lacunar vacancy, suggestive of impaired post-wounding osteocyte survival. While P188 treatment rescued loading-induced increases in BMD in the Prkd1 CKO mice, it surprisingly further suppressed loading-induced increases in cortical bone thickness and cortical bone formation. Taken together, these data suggest that Prkd1 may play a pivotal role in the regulation and repair of the PMD response in osteocytes and support the idea that PMD repair processes can be pharmacologically targeted to modulate downstream responses, but suggest limited utility of PMD repair-promoting P188 in improving bone anabolic responses to loading.

Quality management system in forensic science: An African perspective.

Critical issues in forensic science quality management have emerged in recent decades. The debate on accrediting quality management systems of forensic laboratories is relevant to the African context. Neuteboom, Ross, Bugeja, Willis, Roux, and Lothridge (2022) have conducted a comprehensive survey exploring critical issues in their article "Quality Management in Forensic Science: A Closer Inspection." Their work is a crucial foundation for our discussion, urging the African forensic community to engage in more in-depth conversations. This letter briefly describes the survey, discussing embracing the Sydney Declaration (SD) for Forensic Sciences and issues of quality management systems comprising standards, accreditation, and potential regulation, and highlights the issue of cognitive competency from an African perspective. This underscores the urgent need for critical dialogue, emphasizing that the time for action is now, and urges practitioners, particularly in Africa, to enhance quality management systems to deliver superior forensic products.

Forensic training- bridging the gap between education and workplace.

Outreach initiatives involves mentoring students, university collaboration, and program creation to diversify roles between academia and forensic practitioners. Mixer exercises foster student-forensic scientist interaction. Emphasis is placed on improving understanding of forensic science, particularly in regions like Southern Africa, where media portrayals often distort perceptions. The outreach initiative aims to correct these misconceptions, promote evidence-based forensic education, and address research shortages through collaboration between forensic laboratories and universities. A permanent committee within the Southern Africa Regional Forensic Science Forum is proposed to facilitate cooperation and coordination. By fostering collaboration and encouraging participation in conferences and research publication, the initiative aims to meet the region's forensic scientist needs.

Contamination in complex healthcare trials: the falls in care homes (FinCH) study experience.

BACKGROUND: Trials are at risk of contamination bias which can occur when participants in the control group are inadvertently exposed to the intervention. This is a particular risk in rehabilitation studies where it is easy for trial interventions to be either intentionally or inadvertently adopted in control settings. The Falls in Care Homes (FinCH) trial is used in this paper as an example of a large randomised controlled trial of a complex intervention to explore the potential risks of contamination bias. We outline the FinCH trial design, present the potential risks from contamination bias, and the strategies used in the design of the trial to minimise or mitigate against this. The FinCH trial was a multi-centre randomised controlled trial, with embedded process evaluation, which evaluated whether systematic training in the use of the Guide to Action Tool for Care Homes reduced falls in care home residents. Data were collected from a number of sources to explore contamination in the FinCH trial. Where specific procedures were adopted to reduce risk of, or mitigate against, contamination, this was recorded. Data were collected from study e-mails, meetings with clinicians, research assistant and clinician network communications, and an embedded process evaluation in six intervention care homes. During the FinCH trial, there were six new falls prevention initiatives implemented outside the study which could have contaminated our intervention and findings. Methods used to minimise contamination were: cluster randomisation at the level of care home; engagement with the clinical community to highlight the risks of early adoption; establishing local collaborators in each site familiar with the local context; signing agreements with NHS falls specialists that they would maintain confidentiality regarding details of the intervention; opening additional research sites; and by raising awareness about the importance of contamination in research among participants. CONCLUSION: Complex rehabilitation trials are at risk of contamination bias. The potential for contamination bias in studies can be minimized by strengthening collaboration and dialogue with the clinical community. Researchers should recognise that clinicians may contaminate a study through lack of research expertise.

Outbreak of Escherichia coli O157 Phage Type 32 linked to the consumption of venison products.

In September 2015, an outbreak of Escherichia coli Phage Type 32 with an indistinguishable multi locus variable number tandem repeat analysis profile was identified in Scotland. Twelve cases were identified; nine primary cases, two secondary and one asymptomatic case. Extensive food history investigations identified venison products containing wild venison produced by a single food business operator as the most likely source of the outbreak. Of the nine primary cases, eight had consumed venison products, and one case had not eaten venison themselves but had handled and cooked raw venison in the household. This was the first reported outbreak of Shiga toxin-producing Escherichia coli (STEC) linked to venison products in the UK, and was also notable due to the implicated products being commercially produced and widely distributed. In contrast, previous venison outbreaks reported from other countries have tended to be smaller and related to individually prepared carcases. The outbreak has highlighted some important knowledge gaps in relation to STEC in venison that are currently been investigated via a number of research studies.

Measuring the migration of the components and polyethylene wear after total hip arthroplasty: beads and specialised radiographs are not necessary.

AIMS: This paper describes the methodology, validation and reliability of a new computer-assisted method which uses models of the patient's bones and the components to measure their migration and polyethylene wear from radiographs after total hip arthroplasty (THA). MATERIALS AND METHODS: Models of the patient's acetabular and femoral component obtained from the manufacturer and models of the patient's pelvis and femur built from a single computed tomography (CT) scan, are used by a computer program to measure the migration of the components and the penetration of the femoral head from anteroposterior and lateral radiographs taken at follow-up visits. The program simulates the radiographic setup and matches the position and orientation of the models to outlines of the pelvis, the acetabular and femoral component, and femur on radiographs. Changes in position and orientation reflect the migration of the components and the penetration of the femoral head. Validation was performed using radiographs of phantoms simulating known migration and penetration, and the clinical feasibility of measuring migration was assessed in two patients. RESULTS: Migration of the acetabular and femoral components can be measured with limits of agreement (LOA) of 0.37 mm and 0.33 mm, respectively. Penetration of the femoral head can be measured with LOA of 0.161 mm. CONCLUSION: The migration of components and polyethylene wear can be measured without needing specialised radiographs. Accurate measurement may allow earlier prediction of failure after THA. Cite this article: Bone Joint J 2017;99-B:1290-7.

Squamous cell carcinoma of the pinna: which histological features could be used to predict prognosis?

Squamous cell carcinoma (SCC) that originates in the pinna is thought to have a high risk of metastases (up to 16%) compared with under 5% for cutaneous SCC at any other site, and histological features of the primary tumour may provide evidence for further surveillance or treatment. To identify any association between histological features and the risk of metastases we made an electronic search of the histopathological records at the University Hospital Southampton NHS Foundation Trust for all patients who presented with auricular SCC from 2007-2012. Inclusion criteria included origin in the pinna, complete two-year follow up, and no history of immunosuppressive treatment. We looked for histopathological features that were thought to be relevant to metastases. We studied specimens from 192 patients, four of whom developed metastases (2%), each with involved lymph nodes. Perineural invasion and local recurrence were significantly associated with increased risk of metastases (p<0.001 and p=0.006). The overall metastatic rate was much lower than those reported in other studies, and factors other than histological features alone may explain the results. We suggest that although some histological features were significantly associated, they do not predict a high enough risk of metastatic disease to provide evidence for further surveillance or elective lymphadenopathy.

Noise from total hip replacements: a case-controlled study.

OBJECTIVES: Our study aimed to examine not only the incidence but also the impact of noise from two types of total hip replacement articulations: ceramic-on-ceramic and ceramic-on-polyethylene. METHODS: We performed a case-controlled study comparing subjective and objective questionnaire scores of patients receiving a ceramic-on-ceramic or a ceramic-on-polyethylene total hip replacement by a single surgeon. RESULTS: There was a threefold higher incidence of noise from patients in the ceramic-on-ceramic group compared with the control group. The impact of this noise was significant for patients both subjectively and objectively. CONCLUSIONS: This study reports a high patient impact of noise from ceramic-on-ceramic total hip replacements. This has led to a change in practice by the principal author. Cite this article: Bone Joint Res 2014;3:183-6.

A detailed description of an economical setup for electroporation of chick embryos in ovo.

One of the challenges of the postgenomic era is characterizing the function and regulation of specific genes. For various reasons, the early chick embryo can easily be adopted as an in vivo assay of gene function and regulation. The embryos are robust, accessible, easily manipulated, and maintained in the laboratory. Genomic resources centered on vertebrate organisms increase daily. As a consequence of optimization of gene transfer protocols by electroporation, the chick embryo will probably become increasingly popular for reverse genetic analysis. The challenge of establishing chick embryonic electroporation might seem insurmountable to those who are unfamiliar with experimental embryological methods. To minimize the cost, time, and effort required to establish a chick electroporation assay method, we describe and illustrate in great detail the procedures involved in building a low-cost electroporation setup and the basic steps of electroporation.

A detailed description of an economical setup for electroporation of chick embryos in ovo

One of the challenges of the postgenomic era is characterizing the function and regulation of specific genes. For various reasons, the early chick embryo can easily be adopted as an in vivo assay of gene function and regulation. The embryos are robust, accessible, easily manipulated, and maintained in the laboratory. Genomic resources centered on vertebrate organisms increase daily. As a consequence of optimization of gene transfer protocols by electroporation, the chick embryo will probably become increasingly popular for reverse genetic analysis. The challenge of establishing chick embryonic electroporation might seem insurmountable to those who are unfamiliar with experimental embryological methods. To minimize the cost, time, and effort required to establish a chick electroporation assay method, we describe and illustrate in great detail the procedures involved in building a low-cost electroporation setup and the basic steps of electroporation.

Sleep restriction and serving accuracy in performance tennis players, and effects of caffeine.

Athletes often lose sleep on the night before a competition. Whilst it is unlikely that sleep loss will impair sports mostly relying on strength and endurance, little is known about potential effects on sports involving psychomotor performance necessitating judgement and accuracy, rather than speed, as in tennis for example, and where caffeine is 'permitted'. Two studies were undertaken, on 5h sleep (33%) restriction versus normal sleep, on serving accuracy in semi-professional tennis players. Testing (14:00 h-16:00 h) comprised 40 serves into a (1.8 m×1.1 m) 'service box' diagonally, over the net. Study 1 (8 m; 8 f) was within-Ss, counterbalanced (normal versus sleep restriction). Study 2 (6m;6f -different Ss) comprised three conditions (Latin square), identical to Study 1, except for an extra sleep restriction condition with 80 mg caffeine vs placebo in a sugar-free drink, given (double blind), 30 min before testing. Both studies showed significant impairments to serving accuracy after sleep restriction. Caffeine at this dose had no beneficial effect. Study 1 also assessed gender differences, with women significantly poorer under all conditions, and non-significant indications that women were more impaired by sleep restriction (also seen in Study 2). We conclude that adequate sleep is essential for best performance of this type of skill in tennis players and that caffeine is no substitute for 'lost sleep'. 210.

Mobile- versus fixed-bearing modern total knee replacements- which is the more patella-friendly design?: The 11-year New Zealand Joint Registry study.

OBJECTIVES: Our study aimed to examine if a mobile-bearing total knee replacement (TKR) offered an advantage over fixed-bearing designs with respect to rates of secondary resurfacing of the patella in knees in which it was initially left unresurfaced. METHODS: We examined the 11-year report of the New Zealand Joint Registry and identified all primary TKR designs that had been implanted in > 500 knees without primary resurfacing of the patella. We examined how many of these were mobile-bearing, fixed-bearing cruciate-retaining and fixed-bearing posterior-stabilised designs. We assessed the rates of secondary resurfacing of the patella for each group and constructed Kaplan-Meier survival curves. RESULTS: Our study showed a significantly higher rate of revision for secondary resurfacing of the patella in the fixed-bearing posterior-stabilised TKR designs compared with either fixed-bearing cruciate-retaining or mobile-bearing designs (p = 0.001 and p = 0.036, respectively). CONCLUSIONS: This New Zealand Registry study shows that during the last 11 years, revision procedures to resurface an unresurfaced patella in primary TKR occurred at a higher rate in fixed-bearing posterior-stabilised designs.

Long-term panmixia in a cosmopolitan Indo-Pacific coral reef fish and a nebulous genetic boundary with its broadly sympatric sister species.

Phylogeographical studies have shown that some shallow-water marine organisms, such as certain coral reef fishes, lack spatial population structure at oceanic scales, despite vast distances of pelagic habitat between reefs and other dispersal barriers. However, whether these dispersive widespread taxa constitute long-term panmictic populations across their species ranges remains unknown. Conventional phylogeographical inferences frequently fail to distinguish between long-term panmixia and metapopulations connected by gene flow. Moreover, marine organisms have notoriously large effective population sizes that confound population structure detection. Therefore, at what spatial scale marine populations experience independent evolutionary trajectories and ultimately species divergence is still unclear. Here, we present a phylogeographical study of a cosmopolitan Indo-Pacific coral reef fish Naso hexacanthus and its sister species Naso caesius, using two mtDNA and two nDNA markers. The purpose of this study was two-fold: first, to test for broad-scale panmixia in N. hexacanthus by fitting the data to various phylogeographical models within a Bayesian statistical framework, and second, to explore patterns of genetic divergence between the two broadly sympatric species. We report that N. hexacanthus shows little population structure across the Indo-Pacific and a range-wide, long-term panmictic population model best fit the data. Hence, this species presently comprises a single evolutionary unit across much of the tropical Indian and Pacific Oceans. Naso hexacanthus and N. caesius were not reciprocally monophyletic in the mtDNA markers but showed varying degrees of population level divergence in the two nuclear introns. Overall, patterns are consistent with secondary introgression following a period of isolation, which may be attributed to oceanographic conditions of the mid to late Pleistocene, when these two species appear to have diverged.

Do joint registries report true rates of hip dislocation?

BACKGROUND: Despite advances in primary THA, dislocation remains a common complication. In New Zealand (NZ), dislocations are reported to the National Joint Registry (NJR) only when prosthetic components are revised in the treatment of a dislocation. Closed reductions of dislocated hips are not recorded by the NJR. QUESTIONS/PURPOSES: We compared the true dislocation rate for patients receiving primary THA in the Wellington region with the rate reported by the NZ NJR for the same group of patients. METHODS: The NZ NJR identified 570 patients undergoing primary THA from January 1, 2008, to December 31, 2009, with addresses in the Wellington region. The mean age was 67.5 years (range, 27-96 years). The minimum followup was 2 years (mean, 3 years; range, 2-4 years). RESULTS: Six patients required revision of at least one component for dislocation. There was 100% agreement between the hospital database and the NJR. Using the NJR criteria of revision of any component as an end point, the dislocation rate in the Wellington region after primary THA was 1.05%. The hospital database identified a further eight patients who presented with a dislocation of their primary THA and underwent a closed reduction. These patients were not recorded by the NJR. The true rate of all dislocations, which includes closed reductions, was 2.46%. CONCLUSIONS: This article documents the discrepancy between the NZ NJR reported rate of revision for dislocation and the true rate of dislocation in primary THA. We recommend documentation of all dislocations by NJR in their database to allow more accurate comparisons between centers and research outcomes. LEVEL OF EVIDENCE: Level IV, clinical research study. See Guidelines for Authors for a complete description of levels of evidence.

Multifrequency species classification of acoustic-trawl survey data using semi-supervised learning with class discovery.

Acoustic surveys often use multifrequency backscatter to estimate fish and plankton abundance. Direct samples are used to validate species classification of acoustic backscatter, but samples may be sparse or unavailable. A generalized Gaussian mixture model was developed to classify multifrequency acoustic backscatter when not all species classes are known. The classification, based on semi-supervised learning with class discovery, was applied to data collected in the eastern Bering Sea during summers 2004, 2007, and 2008. Walleye pollock, euphausiids, and two other major classes occurring in the upper water column were identified.

'Post-lunch' sleepiness during prolonged, monotonous driving - effects of meal size.

The 'post-lunch' dip is a bi-circadian phenomenon, largely unrelated to lunch, and worsened by a disturbed prior night's sleep. Despite anecdotal claims of adverse effects of larger lunches on afternoon driving ability, there is little actual driving data to support this belief. Although there have been various (non-driving) laboratory studies assessing meal size and micronutrient effects on psychological performance tests, findings are mixed. Moreover, most have not utilised heightened afternoon sleepiness after a shortened night's sleep, and few tested beyond 20 min. Using a real car interactive simulator having full size screen projection, we compared the effects on a 2h monotonous afternoon drive, of two very similar, palatable lunches ('light': 305 cal vs 'heavy': 922 cal [having 3× fat and 2× carbohydrate contents]), given double blind in a repeated measures counterbalanced design, to 12 young male drivers whose prior night's sleep had been restricted to 5h. Sleepiness-related lane drifting ('incidents'), subjective sleepiness and EEG (4-11 Hz power - indicative of sleepiness) were logged throughout. The heavy lunch caused significant increases to both incidents and EEG power, and a trend for greater subjective sleepiness. All three indices showed a significant worsening of sleepiness over the drive under both lunch conditions. Whilst there were no significant condition×time interactions, there was no difference between lunches for at least the first 30 min of the drive when, thereafter, the differences appeared. Ours was a realistic driving study, utilising typical lunches, following an unexceptional level of prior sleep loss, and where a heavy lunch exacerbated inherent sleepiness, to further impair monotonous driving.

Medium-term outcome of titanium uncemented stems in revision total hip arthroplasty.

PURPOSE: To assess the medium-term outcome of titanium uncemented modular tapered stems in revision total hip arthroplasty (THA). METHODS: A questionnaire was mailed to 421 patients who underwent revision THA using a titanium uncemented modular tapered stem. 66 of whom underwent re-revision THA. The questionnaire was composed to reveal the Charnley classification, the modified 12-item Oxford hip score, and the Devane patient activity level. RESULTS: 323 (77%) of the patients responded. The mean follow-up time was 6.6 years. 12 patients underwent bilateral revision THA. The mean Oxford hip score was 35.7, compared to 35.8 for all-component revision at postoperative month 6 in the New Zealand Joint Registry. The median Oxford hip scores for the subgroups of the stem-only revision (n=92), all-component revision (n=215), and re-revision (n=16) were 38, 39.9, and 30, respectively. The difference was significant between all-component revision and re-revision (adjusted p=0.003), and between stem-only revision and re-revision (adjusted p=0.037). Regarding patient distribution according to the Charnley class and the Devane patient activity level, the difference was significant between the mean Oxford hip scores of Charnley classes B and C (adjusted p=0.017), and between the Devane patient activity levels of Charnley classes A and C (adjusted p=0.043). CONCLUSION: The medium-term outcome of revision THA using a titanium uncemented modular tapered stem was comparable to that reported for other stems.

Obesity and short sleep: unlikely bedfellows?

The link between habitual short sleep and obesity is critically examined from a sleep perspective. Sleep estimates are confounded by 'time in bed', naps; the normal distribution of sleep duration. Wide categorizations of 'short sleep', with claims that <7 h sleep is associated with obesity and morbidity, stem from generalizations from 5 h sleepers (<8% of adults) and acute restriction studies involving unendurable sleepiness. Statistically significant epidemiological findings are of questionable clinical concern, even for 5 h sleepers, as any weight gains accumulate slowly over years; easily redressed by e.g. short exercise exposures, contrasting with huge accumulations of 'lost' sleep. Little evidence supports 'more sleep', alone, as an effective treatment for obesity. Impaired sleep quality and quantity are surrogates for many physical and psychological disorders, as can be obesity. Advocating more sleep, in these respects, could invoke unwarranted use of sleep aids including hypnotics. Inadequate sleep in obese children is usually symptomatic of problems not overcome by increasing sleep alone. Interestingly, neuropeptides regulating interactions between sleep, locomotion and energy balance in normal weight individuals, are an avenue for investigation in some obese short sleepers. The real danger of inadequate sleep lies with excessive daytime sleepiness, not obesity.

Highly crosslinked polyethylene reduces wear in total hip arthroplasty at 5 years.

BACKGROUND: Although hip arthroplasty reliably relieves pain and improves function, problems have arisen with wear and osteolysis. Highly crosslinked polyethylene has been developed to address this problem although at present there is limited clinical evidence it does so longer term. QUESTIONS/PURPOSES: We compared the in vivo wear of standard versus highly crosslinked polyethylene (HXLP) in primary total hip arthroplasty at a minimum of 5-year followup. METHODS: We enrolled 122 patients in a prospective, double-blinded, randomized trial and followed them annually to assess their progress. Annual radiographs were analyzed using previously validated edge detection software to assess for two-dimensional, three-dimensional, and volumetric wear. The mean follow up was 5.5 years (range, 4.1 to 7 years). RESULTS: The two-dimensional wear measurements for HXLP showed lower wear compared to the conventional group (0.05 mm/year versus 0.26 mm/year, respectively). Three-dimensional and volumetric wear were similarly lower in the HXLP group. CONCLUSIONS: Highly crosslinked polyethylene undergoes substantially less wear than conventional polyethylene at medium term. The effect of hip arthroplasty longevity will need to be assessed with longer-term studies, but this may lead to a decreased need for revision as a result of less wear and osteolysis.