5-HT3 Receptors on Mitochondria Influence Mitochondrial Function.

The 5-hydroxytryptamine 3 (5-HT3) receptor belongs to the pentameric ligand-gated cation channel superfamily. Humans have five different 5-HT3 receptor subunits: A to E. The 5-HT3 receptors are located on the cell membrane, but a previous study suggested that mitochondria could also contain A subunits. In this article, we explored the distribution of 5-HT3 receptor subunits in intracellular and cell-free mitochondria. Organelle prediction software supported the localization of the A and E subunits on the inner membrane of the mitochondria. We transiently transfected HEK293T cells that do not natively express the 5-HT3 receptor with an epitope and fluorescent protein-tagged 5HT3A and 5HT3E subunits. Fluorescence microscopy and cell fractionation indicated that both subunits, A and E, localized to the mitochondria, while transmission electron microscopy revealed the location of the subunits on the mitochondrial inner membrane, where they could form heteromeric complexes. Cell-free mitochondria isolated from cell culture media colocalized with the fluorescent signal for A subunits. The presence of A and E subunits influenced changes in the membrane potential and mitochondrial oxygen consumption rates upon exposure to serotonin; this was inhibited by pre-treatment with ondansetron. Therefore, it is likely that the 5-HT3 receptors present on mitochondria directly impact mitochondrial function and that this may have therapeutic implications.

Tapping into 5-HT3 Receptors to Modify Metabolic and Immune Responses.

5-hydroxytryptamine type 3 (5-HT3) receptors are ligand gated ion channels, which clearly distinguish their mode of action from the other G-protein coupled 5-HT or serotonin receptors. 5-HT3 receptors are well established targets for emesis and gastrointestinal mobility and are used as adjunct targets in treating schizophrenia. However, the distribution of these receptors is wider than the nervous system and there is potential that these additional sites can be targeted to modulate inflammatory and/or metabolic conditions. Recent progress in structural biology and pharmacology of 5-HT3 receptors have provided profound insights into mechanisms of their action. These advances, combined with insights into clinical relevance of mutations in genes encoding 5-HT3 subunits and increasing understanding of their implications in patient's predisposition to diseases and response to the treatment, open new avenues for personalized precision medicine. In this review, we recap on the current status of 5-HT3 receptor-based therapies using a biochemical and physiological perspective. We assess the potential for targeting 5-HT3 receptors in conditions involving metabolic or inflammatory disorders based on recent findings, underscoring the challenges and limitations of this approach.

The difference between a clinical technician and clinical practitioner is in the scope of practice: the need for a bioscience understanding in paramedicine.

"Only teach me what I need to know!" This commonly heard refrain is often spoken by allied health students while studying preclinical sciences (physiology, anatomy, pharmacology). Here we use a clinical scenario undertaken by second-year Bachelor of Paramedic Practice students of acute coronary syndrome to demonstrate the difference in clinical decision making when using a clinical reasoning approach to treatment rather than relying exclusively on a practice guidelines approach. We hope to demonstrate that understanding basic bioscience concepts, such as the Frank-Starling mechanism and the anatomy and physiology of the autonomic nervous system, are key to providing good clinical care in response to ambiguous patient symptoms. Students who understand these concepts underlying their patient care guideline will make better clinical decisions and better provide quality of care than students who follow the guideline exclusively. We aim this as a practical demonstration of the value of detailed understanding of human bioscience in allied health education. As health care providers transition from "technician" to "practitioner," the key distinguishing feature of the role is the ability to practice independently, using "best judgment" rather than clinical guidelines (alone). Evidence suggests that complex case management requires detailed bioscience understanding.

Omega 3 polyunsaturated fatty acids and the treatment of depression.

Depression is a common, recurrent, and debilitating illness that has become more prevalent over the past 100 years. This report reviews the etiology and pathophysiology of depression, and explores the role of omega 3 polyunsaturated fatty acids (n-3 PUFA) as a possible treatment. In seeking to understand depression, genetic factors and environmental influences have been extensively investigated. Research has led to several hypotheses for the pathophysiological basis of depression but a definitive pathogenic mechanism, or group thereof, has hitherto remained equivocal. To date, treatment has been based on the monoamine hypothesis and hence, selective serotonin reuptake inhibitors have been the most widely used class of medication. In the last decade, there has been considerable interest in n-3 PUFAs and their role in depression. These fatty acids are critical for development and function of the central nervous system. Increasing evidence from epidemiological, laboratory, and randomized placebo-controlled trials suggests deficiency of dietary n-3 PUFAs may contribute to development of mood disorders, and supplementation with n-3 PUFAs may provide a new treatment option. Conclusions based on systematic reviews and meta-analyses of published trials to date vary. Research into the effects of n-3 PUFAs on depressed mood is limited. Furthermore, results from such have led to conflicting conclusions regarding the efficacy of n-3 PUFAs in affecting reduction in symptoms of depression. PUFAs are generally well tolerated by adults and children although mild gastrointestinal effects are reported. There is mounting evidence to suggest that n-3 PUFAs play a role in depression and deserve greater research efforts.

An obstetric sphincter injury risk identification system (OSIRIS): is this a clinically useful tool?

INTRODUCTION AND HYPOTHESIS: To establish the contribution of maternal, fetal and intrapartum factors to the risk of incidence of obstetric anal sphincter injuries (OASIS) and assess the feasibility of an OASIS risk prediction model based on variables available to clinicians prior to birth. METHODS: This was a population-based, retrospective cohort study using single-site data from the birth database of Aarhus University Hospital, Denmark. The participants were all women who had a singleton vaginal birth during the period 1989 to 2006. Univariate and multivariate logistic regression analyses were performed using multiple imputations for missing data and internally validated using bootstrap methods. The main outcome measures were the contributions of maternal, fetal and intrapartum events to the incidence of OASIS. RESULTS: A total of 71,469 women met the inclusion criteria, of whom 1,754 (2.45 %) sustained OASIS. In the multivariate analysis of variables known prior to birth, maternal age 20 - 30 years (OR 1.65, 95 % CI 1.44 - 1.89) and ≥30 years (OR 1.60, 95 % CI 1.39 - 1.85), occipitoposterior fetal position (OR 1.34, 95 % CI 1.06 - 1.70), induction/augmentation of labour (OR 1.46, 95 % CI 1.32 - 1.62), and suspected macrosomia (OR 2.20, 95 % CI 1.97 - 2.45) were independent significant predictors of OASIS, with increasing parity conferring a significant protective effect. The 'prebirth variable' model showed a 95 % sensitivity and a 24 % specificity in predicting OASIS with 1 % probability, and a 3 % sensitivity and a 99 % specificity in predicting OASIS with a 10 % probability. CONCLUSIONS: Our model identified several significant OASIS risk factors that are known prior to actual birth. The prognostic model shows potential for ruling out OASIS (high sensitivity with a low risk cut-off value), but is not useful for ruling in the event.

"A patchwork of services"--caring for women who sustain severe perineal trauma in New South Wales--from the perspective of women and midwives.

BACKGROUND: Current research into severe perineal trauma (3rd and 4th degree) focuses upon identification of risk factors, preventative practices and methods of repair, with little focus on women's experiences of, and interactions with, health professionals following severe perineal trauma (SPT). The aim of this study is to describe current health services provided to women in New South Wales (NSW) who have experienced SPT from the perspective of Clinical Midwifery Consultants (CMC) and women. METHODS: This study used a descriptive qualitative design and reports on the findings of a component of a larger mixed methods study. Data were collected through a semi-structured discussion group using a variety of non-directive, open-ended questions leading CMCs of NSW. A survey was distributed prior to the discussion group to collect further information and enable a more comprehensive understanding of services provided. Data from individual interviews with twelve women who had experienced SPT during vaginal birth is used to provide greater insight into their interactions with, and ease of access to, health service providers in NSW. An integrative approach was undertaken in reporting the findings which involved comparing and analysing findings from the three sets of data. RESULTS: One overarching theme was identified: A Patchwork of Policy and Process which identified that current health services operate in a 'patchwork' manner when caring for women who sustain SPT. They are characterised by lack of consistency in practice and standardisation of care. Within the overarching theme, four subthemes were identified: Falling through the gaps; Qualifications, skills and attitudes of health professionals; Caring for women who have sustained SPT; and Gold standard care: how would it look? CONCLUSION: The findings from this study suggest that current health services in NSW represent a 'patchwork' of service provision for women who have sustained SPT. It appeared that women seek compassionate and supportive care based upon a clear exchange of information, and this should be considered when reflecting upon health service design. This study highlights the benefits of establishing multi-disciplinary collaborative specialist clinics to support women who experience SPT and associated morbidities, with the aim of providing comprehensive physiological and psychological support.

Perineal Assessment and Repair Longitudinal Study (PEARLS): a matched-pair cluster randomized trial.

BACKGROUND: Perineal trauma during childbirth affects millions of women worldwide every year. The aim of the Perineal Assessment and Repair Longitudinal Study (PEARLS) was to improve maternal clinical outcomes following childbirth through an enhanced cascaded multiprofessional training program to support implementation of evidence-based perineal management. METHODS: This was a pragmatic matched-pair cluster randomized controlled trial (RCT) that enrolled women (n = 3681) sustaining a second-degree perineal tear in one of 22 UK maternity units (clusters), organized in 11 matched pairs. Units in each matched pair were randomized to receive the training intervention either early (group A) or late (group B). Outcomes within each cluster were assessed prior to any training intervention (phase 1), and then after the training intervention was given to group A (phase 2) and group B (phase 3). Focusing on phase 2, the primary outcome was the percentage of women who had pain on sitting or walking at 10 to 12 days post-natal. Secondary outcomes included use of pain relief at 10 to 12 days post-natal, need for suture removal, uptake and duration of exclusive breastfeeding, and perineal wound infection. Practice-based measures included implementation of evidence into practice to promote effective clinical management of perineal trauma. Cluster-level paired t-tests were used to compare groups A and B. RESULTS: There was no significant difference between the clusters in phase 2 of the study in the average percentage of women reporting perineal pain on sitting and walking at 10 to 12 days (mean difference 0.7%; 95% CI -10.1% to 11.4%; P = 0.89). The intervention significantly improved overall use of evidence-based practice in the clinical management of perineal trauma. Following the training intervention, group A clusters had a significant reduction in mean percentages of women reporting perineal wound infections and of women needing sutures removed. CONCLUSION: PEARLS is the first RCT to assess the effects of a 'training package on implementation of evidence-based perineal trauma management. The intervention did not significantly improve the primary outcome but did significantly improve evidence-based practice and some of the relevant secondary clinical outcomes for women. TRIAL REGISTRATIONS: ISRCTN28960026 NIHR UKCRN portfolio no: 4785.

Secondary suturing compared to non-suturing for broken down perineal wounds following childbirth.

BACKGROUND: Each year approximately 350,000 women in the United Kingdom and millions more worldwide, experience perineal suturing following childbirth. The postpartum management of perineal trauma is a core component of routine maternity care. However, for those women whose perineal wound dehisces (breaks down), the management varies depending on individual practitioners preferences as there is limited scientific evidence and no clear guidelines to inform best practice. For most women the wound will be managed expectantly whereas, others may be offered secondary suturing. OBJECTIVES: To evaluate the therapeutic effectiveness of secondary suturing of dehisced perineal wounds compared to non-suturing (healing by secondary intention, expectancy). SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2013) and reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials of secondary suturing of dehisced perineal wounds (second-, third- or fourth-degree tear or episiotomy), following wound debridement and the removal of any remaining suture material within the first six weeks following childbirth compared with non-suturing. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for inclusion. Two review authors independently assessed trial quality and extracted data. Data were checked for accuracy. MAIN RESULTS: Two small studies of poor methodological quality including 52 women with a dehisced and/or infected episiotomy wound at point of entry have been included.Only one small study presented data in relation to wound healing at less than four weeks, (the primary outcome measure for this review), although no reference was made to demonstrate how healing was measured. There was a trend to favour this outcome in the resuturing group, however, this difference was not statistically significant (risk ratio (RR) 1.69, 95% confidence interval (CI) 0.73 to 3.88, one study, 17 women).Similarly, only one trial reported on rates of dyspareunia (a secondary outcome measure for this review) at two months and six months with no statistically significant difference between both groups; two months, (RR 0.44, 95% CI 0.18 to 1.11, one study, 26 women) and six months, (RR 0.39, 95% CI 0.04 to 3.87, one study 32 women). This trial also included data on the numbers of women who resumed sexual intercourse by two months and six months. Significantly more women in the secondary suturing group had resumed intercourse by two months (RR 1.78, 95% CI 1.10 to 2.89, one study, 35 women), although by six months there was no significant difference between the two groups (RR 1.08, 95% CI, 0.91 to 1.28).Neither of the trials included data in relation to the following prespecified secondary outcome measures: pain at any time interval; the woman's satisfaction with the aesthetic results of the perineal wound; exclusive breastfeeding; maternal anxiety or depression. AUTHORS' CONCLUSIONS: Based on this review, there is currently insufficient evidence available to either support or refute secondary suturing for the management of broken down perineal wounds following childbirth. There is an urgent need for a robust randomised controlled trial to evaluate fully the comparative effects of both treatment options.

Methods of repair for obstetric anal sphincter injury.

BACKGROUND: Anal sphincter injury during childbirth - obstetric anal sphincter injuries (OASIS) - are associated with significant maternal morbidity including perineal pain, dyspareunia (painful sexual intercourse) and anal incontinence, which can lead to psychological and physical sequelae. Many women do not seek medical attention because of embarrassment. The two recognised methods for the repair of damaged external anal sphincter (EAS) are end-to-end (approximation) repair and overlap repair. OBJECTIVES: To compare the effectiveness of overlap repair versus end-to-end repair following OASIS in reducing subsequent anal incontinence, perineal pain, dyspareunia and improving quality of life. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2013) and reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials comparing different techniques of immediate primary repair of EAS following OASIS. DATA COLLECTION AND ANALYSIS: Trial quality was assessed independently by all authors. MAIN RESULTS: Six eligible trials, of variable quality, involving 588 women, were included. There was considerable heterogeneity in the outcome measures, time points and reported results. Meta-analyses showed that there was no statistically significant difference in perineal pain (risk ratio (RR) 0.08, 95% confidence interval (CI) 0.00 to 1.45, one trial, 52 women), dyspareunia (average RR 0.77, 95% CI 0.48 to 1.24, two trials, 151 women), flatus incontinence (average RR 1.14, 95% CI 0.58 to 2.23, three trials, 256 women) between the two repair techniques at 12 months. However, it showed a statistically significant lower incidence of faecal urgency (RR 0.12, 95% CI 0.02 to 0.86, one trial, 52 women), and lower anal incontinence score (standardised mean difference (SMD) -0.70, 95% CI -1.26 to -0.14, one trial, 52 women) in the overlap group. The overlap technique was also associated with a statistically significant lower risk of deterioration of anal incontinence symptoms over 12 months (RR 0.26, 95% CI 0.09 to 0.79, one trial, 41 women). There was no significant difference in quality of life. At 36 months follow-up, there was no difference in flatus incontinence (average RR 1.12, 95% CI 0.63 to 1.99, one trial, 68 women) or faecal incontinence (average RR 1.01, 95% CI 0.34 to 2.98, one trial, 68 women). AUTHORS' CONCLUSIONS: The data available show that at one-year follow-up, immediate primary overlap repair of the external anal sphincter compared with immediate primary end-to-end repair appears to be associated with lower risks of developing faecal urgency and anal incontinence symptoms. At the end of 36 months there appears to be no difference in flatus or faecal incontinence between the two techniques. However, since this evidence is based on only two small trials, more research evidence is needed in order to confirm or refute these findings.

Risk of recurrence, subsequent mode of birth and morbidity for women who experienced severe perineal trauma in a first birth in New South Wales between 2000-2008: a population based data linkage study.

BACKGROUND: Severe perineal trauma occurs in 0.5-10% of vaginal births and can result in significant morbidity including pain, dyspareunia and faecal incontinence. The aim of this study is to determine the risk of recurrence, subsequent mode of birth and morbidity for women who experienced severe perineal trauma during their first birth in New South Wales (NSW) between 2000 - 2008. METHOD: All singleton births recorded in the NSW Midwives Data Collection between 2000-2008 (n=510,006) linked to Admitted Patient Data were analysed. Determination of morbidity was based upon readmission to hospital within a 12 month time period following birth for a surgical procedure falling within four categories: 1. Vaginal repair, 2. Fistula repair, 3. Faecal and urinary incontinence repair, and 4. Rectal/anal repair. Women who experienced severe perineal trauma during their first birth were compared to women who did not. RESULTS: 2,784 (1.6%) primiparous women experienced severe perineal trauma during this period. Primiparous women experiencing severe perineal trauma were less likely to have a subsequent birth (56% vs 53%) compared to those not who did not (OR 0.9; CI 0.81-0.99), however there was no difference in the subsequent rate of elective caesarean section (OR 1.2; 0.95-1.54), vaginal birth (including instrumental birth) (OR 1.0; CI 0.81-1.17) or normal vaginal birth (excluding instrumental birth) (OR 1.0; CI 0.85-1.17). Women were no more likely to have a severe perineal tear in the second birth if they experienced this in the first (OR 0.9; CI 0.67-1.34). Women who had a severe perineal tear in their first birth were significantly more likely to have an 'associated surgical procedure' within the ≤12 months following birth (vaginal repair following primary repair, rectal/anal repair following primary repair, fistula repair and urinary/faecal incontinence repair) (OR 7.6; CI 6.21-9.22). Women who gave birth in a private hospital compared to a public hospital were more likely to have an 'associated surgical procedure' in the 12 months following the birth (OR 1.8; CI 1.54-1.97), regardless of parity, birth type and perineal status. CONCLUSION: Primiparous women who experience severe perineal trauma are less likely to have a subsequent baby, more likely to have a related surgical procedure in the 12 months following the birth and no more likely to have an operative birth or another severe perineal tear in a subsequent birth. Women giving birth in a private hospital are more likely to have an associated surgical procedure in the 12 months following birth.

The development and validation of an internet-based training package for the management of perineal trauma following childbirth: MaternityPEARLS.

BACKGROUND: Birth-related perineal trauma has a major impact on women's health. Appropriate management of perineal injuries requires clinical knowledge and skill. At present, there is no agreement as to what constitutes an effective clinical training programme, despite the presence of sufficient evidence to support standardised perineal repair techniques. To address this deficiency, we developed and validated an interactive distance learning multi-professional training package called MaternityPEARLS. METHOD: MaternityPEARLS was developed as a comprehensive e-learning package in 2010. The main aim of the MaternityPEARLS project was to develop, refine and validate this multi-professional e-learning tool. The effect of MaternityPEARLS in improving clinical skills and knowledge was compared with two other training models; traditional training (lectures + model-based hands on training) and offline computer lab-based training. Midwives and obstetricians were recruited for each training modality from three maternity units. An analysis of covariance was done to assess the effects of clinical profession and years of experience on scoring within each group. Feedback on MaternityPEARLS was also collected from participants. The project started in January 2010 and was completed in December 2010. RESULTS: Thirty-eight participants were included in the study. Pretraining and post-training scores in each group showed considerable improvement in skill scores (p<0.001 in all groups). Mean changes were similar across all three groups for knowledge (3.24 (SD 5.38), 3.00 (SD 3.74), 3.30 (SD 3.73)) and skill (25.34 (SD 8.96), 22.82 (SD 9.24), 20.7 (SD 9.76)) in the traditional, offline computer lab-based and e-learning groups, respectively. There was no evidence of any effect of clinical experience and baseline knowledge on outcomes. CONCLUSIONS: MaternityPEARLS is the first validated perineal trauma management e-learning package. It provides a level of improvement in skill and knowledge comparable to traditional methods of training. However, as an e-learning system, it has the advantage of ensuring the delivery of a standardised, continuously updated curriculum that has global accessibility.

Using a Combination of Indirect Calorimetry, Infrared Thermography, and Blood Glucose Levels to Measure Brown Adipose Tissue Thermogenesis in Humans.

In mammals, brown adipose tissue (BAT) is activated rapidly in response to cold in order to maintain body temperature. Although BAT has been studied greatly in small animals, it is difficult to measure the activity of BAT in humans. Therefore, little is known about the heat-generating capacity and physiological significance of BAT in humans, including the degree to which components of the diet can activate BAT. This is due to the limitations in the currently most used method to assess the activation of BAT-radiolabeled glucose (fluorodeoxyglucose or 18FDG) measured by positron emission tomography-computerized tomography (PET-CT). This method is usually performed in fasted subjects, as feeding induces glucose uptake by the muscles, which can mask the glucose uptake into the BAT. This paper describes a detailed protocol for quantifying total-body human energy expenditure and substrate utilization from BAT thermogenesis by combining indirect calorimetry, infrared thermography, and blood glucose monitoring in carbohydrate-loaded adult males. To characterize the physiological significance of BAT, measures of the impact of BAT activity on human health are critical. We demonstrate a protocol to achieve this by combining carbohydrate loading and indirect calorimetry with measurements of supraclavicular changes in temperature. This novel approach will help to understand the physiology and pharmacology of BAT thermogenesis in humans.

Continuous and interrupted suturing techniques for repair of episiotomy or second-degree tears.

BACKGROUND: Millions of women worldwide undergo perineal suturing after childbirth and the type of repair may have an impact on pain and healing. For more than 70 years, researchers have been suggesting that continuous non-locking suture techniques for repair of the vagina, perineal muscles and skin are associated with less perineal pain than traditional interrupted methods. OBJECTIVES: To assess the effects of continuous versus interrupted absorbable sutures for repair of episiotomy and second-degree perineal tears following childbirth. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 January 2012). SELECTION CRITERIA: Randomised trials examining continuous and interrupted suturing techniques for repair of episiotomy and second-degree tears after vaginal delivery. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trial quality. Two of the three authors independently extracted data and a third review author checked them. We contacted study authors for additional information. MAIN RESULTS: Sixteen studies, involving 8184 women at point of entry, from eight countries, were included. The trials were heterogeneous in respect of operator skill and training. Meta-analysis showed that continuous suture techniques compared with interrupted sutures for perineal closure (all layers or perineal skin only) are associated with less pain for up to 10 days' postpartum (risk ratio (RR) 0.76; 95% confidence interval (CI) 0.66 to 0.88, nine trials). There was an overall reduction in analgesia use associated with the continuous subcutaneous technique versus interrupted stitches for repair of perineal skin (RR 0.70; 95% CI 0.59 to 0.84). There was also a reduction in suture removal in the continuous suturing groups versus interrupted (RR 0.56; 95% CI 0.32 to 0.98), but no significant differences were seen in the need for re-suturing of wounds or long-term pain. AUTHORS' CONCLUSIONS: The continuous suturing techniques for perineal closure, compared with interrupted methods, are associated with less short-term pain, need for analgesia and suture removal. Furthermore, there is also some evidence that the continuous techniques used less suture material as compared with the interrupted methods (one packet compared to two or three packets, respectively).

How good are we at implementing evidence to support the management of birth related perineal trauma? A UK wide survey of midwifery practice.

BACKGROUND: The accurate assessment and appropriate repair of birth related perineal trauma require high levels of skill and competency, with evidence based guideline recommendations available to inform UK midwifery practice. Implementation of guideline recommendations could reduce maternal morbidity associated with perineal trauma, which is commonly reported and persistent, with potential to deter women from a future vaginal birth. Despite evidence, limited attention is paid to this important aspect of midwifery practice. We wished to identify how midwives in the UK assessed and repaired perineal trauma and the extent to which practice reflected evidence based guidance. Findings would be used to inform the content of a large intervention study. METHODS: A descriptive cross sectional study was completed. One thousand randomly selected midwives were accessed via the Royal College of Midwives (RCM) and sent a questionnaire. Study inclusion criteria included that the midwives were in clinical practice and undertook perineal assessment and management within their current role. Quantitative and qualitative data were collated. Associations between midwife characteristics and implementation of evidence based recommendations for perineal assessment and management were examined using chi-square tests of association. RESULTS: 405 midwives (40.5%) returned a questionnaire, 338 (83.5%) of whom met inclusion criteria. The majority worked in a consultant led unit (235, 69.5%) and over a third had been qualified for 20 years or longer (129, 38.2%). Compliance with evidence was poor. Few (6%) midwives used evidence based suturing methods to repair all layers of perineal trauma and only 58 (17.3%) performed rectal examination as part of routine perineal trauma assessment. Over half (192, 58.0%) did not suture all second degree tears. Feeling confident to assess perineal trauma all of the time was only reported by 116 (34.3%) midwives, with even fewer (73, 21.6%) feeling confident to perform perineal repair all of the time. Two thirds of midwives (63.5%) felt confident to perform an episiotomy. Midwives qualified for 20 years or longer and those on more senior clinical grades were most likely to implement evidence based recommendations and feel confident about perineal management. CONCLUSIONS: There are considerable gaps with implementation of evidence to support management of perineal trauma.

A review on various explanations of Ponzo-like illusions.

This article reviews theoretical and empirical arguments for and against various theories that explain the classic Ponzo illusion and its variants from two different viewpoints concerning the role of perceived depth in size distortions. The first viewpoint argues that all Ponzo-like illusions are driven by perceived depth. The second viewpoint argues that the classic Ponzo illusion is unrelated to depth perception. This review will give special focus to the first viewpoint and consists of three sections. In the first section, the role of the number of pictorial depth cues and previous experience in the strength of all Ponzo-like illusions are discussed. In the second section, we contrast the first viewpoint against the theories that explain the classic Ponzo illusion with mechanisms that are unrelated to depth perception. In the last section, we propose a Bayesian-motivated reconceptualization of Richard Gregory's misapplied size constancy theory that explains Ponzo-variant illusions in terms of prior information and prediction errors. The new account explains why some studies have provided inconsistent evidence for misapplied size constancy theory.

A novel movement system screen for primary care providers: a multisite, observational study.

CONTEXT: Movement of the human body is essential for the interaction of an individual within their environment and contributes to both physical and emotional quality of life. Movement system disorders (MSDs) are kinesiopathologic conditions that result from either altered movement patterns, trauma, or pathology. A screening tool may facilitate earlier diagnosis and treatment of acute MSDs. This tool could prevent progression to chronic conditions, leading to better patient outcomes and quality of life. OBJECTIVES: Our study evaluated whether a screening tool would be able to accurately screen individuals for MSDs, explore comorbidities that may predict the prevalence of MSDs, and identify why people do not discuss these problems with their primary care provider (PCP). METHODS: A multisite, observational study in a primary care setting. Data were analyzed to determine the psychometric properties of the screening question. Logistic regression was performed to explore the relationship of comorbidities with MSDs. Thematic analysis was performed to explore why patients do not discuss these issues with their PCP. RESULTS: The point prevalence of MSDs was determined to be 78%. The sensitivity of the screening question was determined to be good (70%). Arthritis, obesity, sleep disorders, and gastroesophageal reflux disease (GERD) were significant predictors for an MSD. Thematic analysis regarding why patients do not discuss the MSD with their physician revealed: (1) the perceived lack of importance of the problem; (2) the lack of access to healthcare, and (3) the acuity of the problem. CONCLUSIONS: Screening for an MSD and associated comorbidities could prevent the transition of acute conditions to chronic conditions. If PCPs can identify predictors and factors associated with an MSD, they may be able to screen for MSDs more effectively. Earlier identification of MSDs may facilitate earlier treatment and prevent costs associated with resulting chronic disorders and persistent pain and disability.

Corrigendum: Both caffeine and Capsicum annuum fruit powder lower blood glucose levels and increase brown adipose tissue temperature in healthy adult males.

[This corrects the article DOI: 10.3389/fphys.2022.870154.].

Both caffeine and Capsicum annuum fruit powder lower blood glucose levels and increase brown adipose tissue temperature in healthy adult males.

Using a combination of respiratory gas exchange, infrared thermography, and blood glucose (BGL) analysis, we have investigated the impact of Capsicum annuum (C. annuum) fruit powder (475 mg) or caffeine (100 mg) on metabolic activity in a placebo controlled (lactose, 100 mg) double-blinded three-way cross-over-design experiment. Metabolic measurements were made on day 1 and day 7 of supplementation in eight adult male participants (22.2 ± 2 years of age, BMI 23 ± 2 kg/m2, x̅ ± SD). Participants arrived fasted overnight and were fed a high carbohydrate meal (90 g glucose), raising BGL from fasting baseline (4.4 ± 0.3 mmol/L) to peak BGL (8.5 ± 0.3 mmol/L) 45 min after the meal. Participants consumed the supplement 45 min after the meal, and both caffeine and C. annuum fruit powder restored BGL (F (8,178) = 2.2, p = 0.02) to near fasting levels within 15 min of supplementation compared to placebo (120 min). In parallel both supplements increased energy expenditure (F (2, 21) = 175.6, p < 0.001) over the 120-min test period (caffeine = 50.74 ± 2 kcal/kg/min, C. annuum fruit = 50.95 ± 1 kcal/kg/min, placebo = 29.34 ± 1 kcal/kg/min). Both caffeine and C. annuum fruit powder increased supraclavicular fossa temperature (F (2,42) = 32, p < 0.001) on both day 1 and day 7 of testing over the 120-min test period. No statistical difference in core temperature or reference point temperature, mean arterial pressure or heart rate was observed due to supplementation nor was any statistical difference seen between day 1 and day 7 of intervention. This is important for implementing dietary ingredients as potential metabolism increasing supplements. Together the results imply that through dietary supplements such as caffeine and C. annuum, mechanisms for increasing metabolism can be potentially targeted to improve metabolic homeostasis in people.

The conceptual understanding of depth rather than the low-level processing of spatial frequencies drives the corridor illusion.

Our objective was to determine how different spatial frequencies affect the perceptual size rescaling of stimuli in the corridor illusion. Two experiments were performed using the method of constant stimuli. In experiment 1, the task required participants to compare the size of comparison and standard rings displayed over the same background image. ANOVA on the points of subject equality (PSEs) revealed that the perceived size of the top and bottom standard rings changed as a function of the availability of the high, medium, and low spatial frequency information. In experiment 2, the task required participants to compare the size of a comparison ring presented outside of the background image with a standard ring presented inside it. ANOVA on the PSEs revealed that the apparent size of the top and not the bottom standard ring changed depending on the availability of medium spatial frequency information. Eye-tracking revealed that the spatial frequency range of the background image in the periphery affected participants' eye positioning, which may explain why the effects of different spatial frequencies fluctuated across experiments. Nonetheless, when we consider these findings together, we propose that the conceptual understanding of depth plays a more important role in explaining the corridor illusion than the low-level processing of depth information extracted from different spatial frequencies along separate channels.

Interocular transfer effects of linear perspective cues and texture gradients in the perceptual rescaling of size.

Our objective was to determine whether the influence of linear perspective cues and texture gradients in the perceptual rescaling of stimulus size transfers from one eye to the other. In experiment 1, we systematically added linear perspective cues and texture gradients in a background image of the corridor illusion. To determine whether perceptual size rescaling takes place at earlier or later stages, we tested how the perceived size of top and bottom rings changed under binocular (rings and background presented to both eyes), monocular (rings and background presented to the dominant eye only), and dichoptic (rings and background presented separately to the dominant and nondominant eyes, respectively) viewing conditions. We found differences between viewing conditions in the perceived size of the rings when linear perspective cues, but not texture gradients, were presented. Specifically, linear perspective cues produced a stronger illusion under the monocular compared to the dichoptic viewing condition. Hence, there was partial interocular transfer from the linear perspective cues, suggesting a dominant role of monocular neural populations in mediating the corridor illusion. In experiment 2, we repeated similar procedures with a more traditional Ponzo illusion background. Contrary to findings from experiment 1, there was a full interocular transfer with the presence of the converging lines, suggesting a dominant role of binocular neural populations. We conclude that higher order visual areas, which contain binocular neural populations, are more involved in the perceptual rescaling of size evoked by linear perspective cues in the Ponzo compared to the corridor illusion.