Two-pore channels regulate endomembrane tension to enable remodeling and resolution of phagolysosomes.

Phagocytes promptly resolve ingested targets to replenish lysosomes and maintain their responsiveness. The resolution process requires that degradative hydrolases, solute transporters, and proteins involved in lipid traffic are delivered and made active in phagolysosomes. It also involves extensive membrane remodeling. We report that cation channels that localize to phagolysosomes were essential for resolution. Specifically, the conductance of Na+ by two-pore channels (TPCs) and the presence of a Na+ gradient between the phagolysosome lumen and the cytosol were critical for the controlled release of membrane tension that permits deformation of the limiting phagolysosome membrane. In turn, membrane deformation was a necessary step to efficiently transport the cholesterol extracted from cellular targets, permeabilizing them to hydrolases. These results place TPCs as regulators of endomembrane remodeling events that precede target degradation in cases when the target is bound by a cholesterol-containing membrane. The findings may help to explain lipid metabolism dysfunction and autophagic flux impairment reported in TPC KO mice and establish stepwise regulation to the resolution process that begins with lysis of the target.

Comparative UK Cross-sectional Study of Breast Cancer Patient-Reported Outcomes for Breast-Conserving Surgery and Immediate Reconstruction, Including Contribution to an International Collaborative Pilot Study.

INTRODUCTION: Breast-conserving surgery (BCS) with adjuvant radiotherapy is oncologically comparable to mastectomy with immediate breast reconstruction (IBR) in treating breast cancer. This tertiary UK centre cross-sectional study compared BCS patient-reported outcomes with those of immediate implant-based (IBR) and free flap reconstruction (FFR), and included a contribution to a pilot international collaboration co-ordinated through the Organisation for Economic Cooperation and Development (OECD). METHODS: Validated BREAST-Q™ 'satisfaction with breasts' modules were administered to 271 consecutive patients for six months after unilateral BCS, IBR, or FFR were conducted between June and October 2018. Risk adjustment data were collected on age, body mass index, smoking, radiotherapy, specimen weight, and tumour burden. RESULTS: A total of 190 women returned completed questionnaires (131 BCS, 42 IBR, 17 FFR; 70% response rate). BCS scores (mean 68, standard deviation (SD) 23) were higher than those for IR overall (62, SD 23, p=0.04) and IBR (61, 24, p=0.03) but equivalent to those for FFR (66, SD 23, p=0.33). There was no significant difference in Q-Scores between the IBR and FFR groups (p=0.77). Scores were only minimally changed by risk adjustment and comparable to OECD mean international scores for IBR (61) and FFR (66). CONCLUSIONS: This is the first study to compare BCS and IR outcomes using a validated scale. BREAST-Q™ 'satisfaction with breasts' scores were comparable between BCS and FFR but significantly lower following IBR.

From the inside out: Ion fluxes at the centre of endocytic traffic.

Endocytic traffic is a complex and elegant operation involving cargo sorting, membrane budding and tubulation, generation of force, and the formation of organellar contacts. The role of specific proteins and lipids in these processes has been studied extensively. By comparison, precious little is understood about the contribution of the endocytic fluid to these events, despite much evidence that alteration of the contents can severely affect membrane traffic along the endocytic pathway. In particular, it has long been appreciated that dissipation of ionic gradients arrests endosome-to-lysosome maturation. How cells sense inorganic ions and transmit this information have remained largely enigmatic. Herein, we review the experimental findings that reveal an intimate association between luminal ions, their transport, and endocytic traffic. We then discuss the ionic sensors and the mechanisms proposed to convert ion concentrations into protein-based trafficking events, highlighting the current paucity of convincing explanations.

Solute Transport Controls Membrane Tension and Organellar Volume.

The regulation of cellular volume in response to osmotic change has largely been studied at the whole cell level. Such regulation occurs by the inhibition or activation of ionic and organic solute transport pathways at the cell surface and is coincident with remodelling of the plasma membrane. However, it is only in rare instances that osmotic insults are experienced by cells and tissues. By contrast, the relatively minute luminal volumes of membrane-bound organelles are constantly subject to shifts in their solute concentrations as exemplified in the endocytic pathway where these evolve alongside with maturation. In this review, we summarize recent evidence that suggests trafficking events are in fact orchestrated by the solute fluxes of organelles that briefly impose osmotic gradients. We first describe how hydrostatic pressure and the resultant tension on endomembranes can be readily dissipated by controlled solute efflux since water is obliged to exit. In such cases, the relief of tension on the limiting membrane of the organelle can promote its remodelling by coat proteins, ESCRT machinery, and motors. Second, and reciprocally, we propose that osmotic gradients between organellar lumens and the cytosol may persist or be created. Such gradients impose osmotic pressure and tension on the endomembrane that prevent its remodelling. The control of endomembrane tension is dysregulated in lysosomal storage disorders and can be usurped by pathogens in endolysosomes. Since trafficking and signaling pathways conceivably sense and respond to endomembrane tension, we anticipate that understanding how cells control organellar volumes and the movement of endocytic fluid in particular will be an exciting new area of research.

Aging and Sexual Health: A Cross-Sectional Survey of Patients in a Canadian Urban Academic Family Health Team.

Primary care physicians are in a position to recognize sexuality as a core component of health. Data examining the sexual behaviours of Canadians over the age of 50 and the role of primary care in this domain is lacking. A cross-sectional survey was administered to patients over the age of 50, which assessed the importance of sexual activity, problems, and preferences in discussing sexual health with their primary care providers. A total of 39 per cent of patients indicated ongoing sexual activity and 52% of male participants reported current sexual activity compared with 25 per cent of females (p < 0.01). More males reported sexual activity as important than did females (69% vs. 45%, p < 0.01). Participants identifying sexual health concerns discussed physical dysfunctions more than emotional, social, or global health concerns (p < 0.01). More male participants discussed sexual health concerns with their family physician than did females (p < 0.01). The results of our study indicate that many individuals over the age of 50 continue to be sexually active, and that physical and non-physical concerns directly impact participation in sexual activity.

A functional unfolded protein response is required for chronological aging in Saccharomyces cerevisiae.

Progressive impairment of proteostasis and accumulation of toxic misfolded proteins are associated with the cellular aging process. Here, we employed chronologically aged yeast cells to investigate how activation of the unfolded protein response (UPR) upon accumulation of misfolded proteins in the endoplasmic reticulum (ER) affects lifespan. We found that cells lacking a functional UPR display a significantly reduced chronological lifespan, which contrasts previous findings in models of replicative aging. We find exacerbated UPR activation in aged cells, indicating an increase in misfolded protein burden in the ER during the course of aging. We also observed that caloric restriction, which promotes longevity in various model organisms, extends lifespan of UPR-deficient strains. Similarly, aging in pH-buffered media extends lifespan, albeit independently of the UPR. Thus, our data support a role for caloric restriction and reduced acid stress in improving ER homeostasis during aging. Finally, we show that UPR-mediated upregulation of the ER chaperone Kar2 and functional ER-associated degradation (ERAD) are essential for proper aging. Our work documents the central role of secretory protein homeostasis in chronological aging in yeast and highlights that the requirement for a functional UPR can differ between post-mitotic and actively dividing eukaryotic cells.

Endoplasmic Reticulum Stress Coping Mechanisms and Lifespan Regulation in Health and Diseases.

Multiple factors lead to proteostatic perturbations, often resulting in the aberrant accumulation of toxic misfolded proteins. Cells, from yeast to humans, can respond to sudden accumulation of secretory proteins within the endoplasmic reticulum (ER) through pathways such as the Unfolded Protein Response (UPR). The ability of cells to adapt the ER folding environment to the misfolded protein burden ultimately dictates cell fate. The aging process is a particularly important modifier of the proteostasis network; as cells age, both their ability to maintain this balance in protein folding/degradation and their ability to respond to insults in these pathways can break down, a common element of age-related diseases (including neurodegenerative diseases). ER stress coping mechanisms are central to lifespan regulation under both normal and disease states. In this review, we give a brief overview of the role of ER stress response pathways in age-dependent neurodegeneration.

Partial thickness wound: Does mechanism of injury influence healing?

Wound healing is a complex multistep process which is temporally and spatially controlled. In partial thickness wounds, regeneration is possible from the stem cells in the edges of the wound and from the remnants of the epidermal appendages (such as hair follicles and sebaceous glands). This study examines whether the mechanism of injury influences healing of wounds of similar depth. Burn and excisional wounds were created on the back of Hampshire pigs and harvested at 7, 14, 28, 44, 57 and 70days after injury and processed for histology and immunohistochemistry. Quantitative analysis of re-epithelialisation, inflammatory response and thickness of the scar and semi-quantitative analyses of the architecture of the resultant scar were performed and subjected to statistical analysis. Results demonstrated a higher number of neutrophils, macrophages and lymphocytes present in the burn on day 7 compared to the excisional wounds. The inflammatory profile of burn wounds was higher than that of excisional wounds for the first month after injury albeit less marked than on day 7 after injury. Re-epithelialisation was markedly advanced in excisional wounds compared to burn wounds at day 7 after injury, corresponding to the higher number of hair follicles in the underlying dermis of excisional wounds at this time point. The thickness of the neo-epidermis increased with time and at day 70 after wounding, the neo-epidermis of the burn was significantly thicker than the neo-epidermis of the excisional scar. Interestingly, following partial thickness excision of skin, there was neo-dermal reformation albeit with an altered architecture, lacking the normal basket-weave pattern of collagen. The thickness of the dermis of partial thickness excisional scar was greater than that of the adjacent unwounded skin. The neo-dermis of the burn scar was even thicker, with the collagen arranged more compactly and disorganised compared to excisional scar and normal skin. This study provides evidence that the mechanism of injury does influence wound healing and the resultant scarring.

Endoplasmic reticulum stress: The cause and solution to Huntington's disease?

Accumulation of misfolded proteins is a hallmark of many human diseases, including several incurable neurological disorders, such as Huntington's disease (HD). In HD, expansion of a polyglutamine stretch within the first exon of the Huntingtin protein (Htt) leads to Htt misfolding, aberrant protein aggregation, and progressive appearance of disease symptoms. Several studies in various organisms (from yeast to humans) have identified the accumulation of misfolded secretory proteins in the endoplasmic reticulum (ER stress) as a crucial determinant of cellular toxicity in HD. In this review, we highlight the recent research linking HD to ER stress. We also discuss how the modulation of signaling pathways responsible for coping with misfolded protein accumulation in the ER may constitute attractive methods to reduce toxicity and identify new therapeutic targets for treatment of HD. This article is part of a Special Issue entitled SI:ER stress.

A Toolbox for Rapid Quantitative Assessment of Chronological Lifespan and Survival in Saccharomyces cerevisiae.

Saccharomyces cerevisiae is a well-established model organism to study the mechanisms of longevity. One of the two aging paradigms studied in yeast is termed chronological lifespan (CLS). CLS is defined by the amount of time non-dividing yeast cells can survive at stationary phase. Here, we propose new approaches that allow rapid and efficient quantification of survival rates in aging yeast cultures using either a fluorescent cell counter or microplate imaging. We have generated a software called analysr (Analytical Algorithm for Yeast Survival Rates) that allows automated and highly reproducible analysis of cell survival in aging yeast cultures using fluorescent data. To demonstrate the efficiency of our new experimental tools, we tested the previously characterized ability of caloric restriction to extend lifespan. Interestingly, we found that this process is independent of the expression of three central yeast heat shock proteins (Hsp26, Hsp42, Hsp104). Finally, our new assay is easily adaptable to other types of toxicity studies. Here, we assessed the toxicity of various concentrations of acetic acid, a known contributor of yeast chronological aging. These assays provide researchers with cost-effective, low- and high-content assays that can serve as an efficient complement to the time-consuming colony forming unit assay usually used in CLS studies.

Pseudoseptic arthritis resulting in joint destruction.

Pseudoseptic arthritis is an increasingly recognised entity. It is an inflammatory arthritis that mimics septic arthritis; however, Gram stain and cultures are persistently negative. It is a diagnosis of exclusion. We present the first case, to date, in which pseudoseptic arthritis led to such severe joint degeneration that joint replacement surgery was required. A 54-year-old truck driver with rheumatoid arthritis, on immunosuppressive therapy, presented with acute onset severe left hip pain. He was given a clinical diagnosis of septic arthritis and treated with two prolonged courses of antibiotics despite persistently negative synovial fluid cultures. He experienced progressive joint destruction necessitating a two-stage total hip replacement. A retrospective diagnosis of pseudoseptic arthritis was made. This case demonstrates the difficulties inherent in differentiating between septic and pseudoseptic arthritis. This case also highlights the importance of accurate diagnosis and treatment for pseudoseptic arthritis to avoid accelerated joint destruction.

Paediatric post-burn scar management in the UK: a national survey.

Thermal injuries affect 250,000 people annually in the United Kingdom. As burn survival improves, good scar management is paramount to help individuals living with the resultant scars lead a life without restrictions. Post-burn hypertrophic scars can limit growth in children, interfere with function and cause psychological problems. In the current literature there is great variation in post-burn scar management across the world and in the evidence available for the efficacy of these management modalities. The aim of this study was to investigate the variances if any, in the management of post-burn scarring in children across the UK. A telephone survey of UK paediatric burn services was conducted to obtain information on post-burn scar management and advice given to patients/carers. Of the 19 burn services that participated, all advised moisturising of scars but with variable emphasis on massaging. Silicones and pressure therapy were used by 18 services but commencement of use varied from soon after healing to onset of hypertrophic scarring. Laser therapy, ultrasound therapy and steroid therapy were used sporadically. This study highlights the common modalities of post-burn scar management in children across the UK. However, there is marked variation in timing and selection of the commonly used modalities. Although this study did not investigate the outcomes of scar management, it clearly identifies the need for a well-designed multi-centred study to establish evidence-based best practice in the management of post-burn scarring in children as these modalities are time consuming and not without potential complications. Evidence based practice could potentially lead to significant financial savings to the health service.

Comparison of infant vitamin D supplement use among Canadian-born, immigrant, and refugee mothers.

PURPOSE: This study compares knowledge and practice of infant vitamin D supplementation among immigrant, refugee, and Canadian-born mothers. METHOD: Focus group discussions with 94 mothers of children aged 0 to 3 years recruited from early childhood centers and a refugee health clinic. FINDINGS: Both immigrant and Canadian-born mothers indicated good knowledge and use of infant vitamin D supplementation. In contrast, Canadian government-assisted refugees were less likely to supplement with vitamin D. The main source of information about vitamin D was public health prenatal classes. Many mothers reported inconsistent guidance from health care providers. DISCUSSION AND CONCLUSIONS: Exclusively breastfed infants of refugees may be more at risk of vitamin D deficiency. All mothers require clear recommendations, both in clinical and public health settings. IMPLICATIONS FOR PRACTICE: Mothers, both new Canadian and Canadian-born, require clear and consistent messaging from health professionals. Refugee mothers, however, require more educational support to promote infant vitamin D supplementation.

Repigmentation of cutaneous scars depends on original wound type.

Cutaneous scarring is currently an inevitable outcome following skin injury. Abnormal pigmentation within scars makes them more noticeable, causing distress for patients, particularly as there is no reliable and effective treatment available to date. The Duroc pig, known to scar badly, was used to investigate repigmentation of scars resulting from three different wound types: incisional, partial thickness excisional and full thickness excisional. Wounds were created on the backs of Duroc pigs and the resulting scars harvested at days 35, 56, 70 and 90 days post-injury. Scars were processed for histology and immunohistochemistry, quantitatively analysed using image analysis software and subjected to statistical analysis. Photographs of the macroscopic appearance of scars were scored for pigmentation using a visual analogue scale. Results demonstrated temporal and spatial differences in melanocyte repopulation and function within scars from different wound types. The microscopic pigment deposition did not correlate with macroscopic appearances in mature scars. Pigmentation of scars is dependent on the width and depth of wounds. This study has provided important information on which we can base future studies to investigate factors controlling the repigmentation of scars.

Tattoos: ancient body art may assist in medical emergencies.

Tattooing, like medicine, is an ancient art form. However, in the UK, tattooing of minors is illegal except when performed for medical reasons. We present a 15-year-old type I diabetic, who being prone to hypoglycaemic attacks, had a permanent medical alert tattoo on his forearm, with his parents' consent, whilst on holiday abroad. Tattooing to convey a medical message is employed by many adults for reasons as diverse as anaphylaxis to do not resuscitate orders. We present the patient and propose that clinicians may wish to consider supporting tattooing to convey a medical alert in young people, particularly those at risk of life-threatening complications, such as hypoglycaemia.

Abnormal pigmentation within cutaneous scars: A complication of wound healing.

Abnormally pigmented scars are an undesirable consequence of cutaneous wound healing and are a complication every single individual worldwide is at risk of. They present a challenge for clinicians, as there are currently no definitive treatment options available, and render scars much more noticeable making them highly distressing for patients. Despite extensive research into both wound healing and the pigment cell, there remains a scarcity of knowledge surrounding the repigmentation of cutaneous scars. Pigment production is complex and under the control of many extrinsic and intrinsic factors and patterns of scar repigmentation are unpredictable. This article gives an overview of human skin pigmentation, repigmentation following wounding and current treatment options.

The prevalence of traumatic brain injury in the homeless community in a UK city.

PRIMARY OBJECTIVE: The main aim of the study was to investigate the prevalence of traumatic brain injury in a sample of homeless individuals. RESEARCH DESIGN: The researchers employed a cross-sectional survey design and contacted 12 organizations providing services for homeless individuals across a city in the UK. METHODS AND PROCEDURES: The sample included 100 homeless participants (75 males and 25 females) who met the inclusion criteria. A matched control group (n = 100) of individuals who were not homeless was also recruited. A questionnaire was administered to all participants to elicit information relating to history of possible traumatic brain injury. MAIN OUTCOMES AND RESULTS: Results indicated that a significantly higher number of homeless participants (48%) reported a history of traumatic brain injury than control participants (21%). Of those homeless participants, 90% indicated they had sustained their first traumatic brain injury before they were homeless. CONCLUSIONS: These findings suggest that rates of traumatic brain injury are much higher among the homeless population than in the general population and that sustaining a traumatic brain injury may be a risk factor for homelessness.