Chloride/proton antiporters ClC3 and ClC5 support bone formation in mice.

Acid transport is required for bone synthesis by osteoblasts. The osteoblast basolateral surface extrudes acid by Na+/H+ exchange, but apical proton uptake is undefined. We found high expression of the Cl-/H+ exchanger ClC3 at the bone apical surface. In mammals ClC3 functions in intracellular vesicular chloride transport, but when we found Cl- dependency of H+ transport in osteoblast membranes, we queried whether ClC3 Cl-/H+ exchange functions in bone formation. We used ClC3 knockout animals, and closely-related ClC5 knockout animals: In vitro studies suggested that both ClC3 and ClC5 might support bone formation. Genotypes were confirmed by total exon sequences. Expression of ClC3, and to a lesser extent of ClC5, at osteoblast apical membranes was demonstrated by fluorescent antibody labeling and electron microscopy with nanometer gold labeling. Animals with ClC3 or ClC5 knockouts were viable. In ClC3 or ClC5 knockouts, bone formation decreased ~40 % by calcein and xylenol orange labeling in vivo. In very sensitive micro-computed tomography, ClC5 knockout reduced bone relative to wild type, consistent with effects of ClC3 knockout, but varied with specific histological parameters. Regrettably, ClC5-ClC3 double knockouts are not viable, suggesting that ClC3 or ClC5 activity are essential to life. We conclude that ClC3 has a direct role in bone formation with overlapping but probably slightly smaller effects of ClC5. The mechanism in mineral formation might include ClC H+ uptake, in contrast to ClC3 and ClC5 function in cell vesicles or other organs.

Epithelial-like transport of mineral distinguishes bone formation from other connective tissues.

We review unique properties of bone formation including current understanding of mechanisms of bone mineral transport. We focus on formation only; mechanism of bone degradation is a separate topic not considered. Bone matrix is compared to other connective tissues composed mainly of the same proteins, but without the specialized mechanism for continuous transport and deposition of mineral. Indeed other connective tissues add mechanisms to prevent mineral formation. We start with the epithelial-like surfaces that mediate transport of phosphate to be incorporated into hydroxyapatite in bone, or in its ancestral tissue, the tooth. These include several phosphate producing or phosphate transport-related proteins with special expression in large quantities in bone, particularly in the bone-surface osteoblasts. In all connective tissues including bone, the proteins that constitute the protein matrix are mainly type I collagen and γ-carboxylate-containing small proteins in similar molar quantities to collagen. Specialized proteins that regulate connective tissue structure and formation are surprisingly similar in mineralized and non-mineralized tissues. While serum calcium and phosphate are adequate to precipitate mineral, specialized mechanisms normally prevent mineral formation except in bone, where continuous transport and deposition of mineral occurs.

Current challenges and future directions for engineering extracellular vesicles for heart, lung, blood and sleep diseases.

Extracellular vesicles (EVs) carry diverse bioactive components including nucleic acids, proteins, lipids and metabolites that play versatile roles in intercellular and interorgan communication. The capability to modulate their stability, tissue-specific targeting and cargo render EVs as promising nanotherapeutics for treating heart, lung, blood and sleep (HLBS) diseases. However, current limitations in large-scale manufacturing of therapeutic-grade EVs, and knowledge gaps in EV biogenesis and heterogeneity pose significant challenges in their clinical application as diagnostics or therapeutics for HLBS diseases. To address these challenges, a strategic workshop with multidisciplinary experts in EV biology and U.S. Food and Drug Administration (USFDA) officials was convened by the National Heart, Lung and Blood Institute. The presentations and discussions were focused on summarizing the current state of science and technology for engineering therapeutic EVs for HLBS diseases, identifying critical knowledge gaps and regulatory challenges and suggesting potential solutions to promulgate translation of therapeutic EVs to the clinic. Benchmarks to meet the critical quality attributes set by the USFDA for other cell-based therapeutics were discussed. Development of novel strategies and approaches for scaling-up EV production and the quality control/quality analysis (QC/QA) of EV-based therapeutics were recognized as the necessary milestones for future investigations.

Phagosomal chloride dynamics in the alveolar macrophage.

Acidification in intracellular organelles is tightly linked to the influx of Cl- counteracting proton translocation by the electrogenic V-ATPase. We quantified the dynamics of Cl- transfer accompanying cargo incorporation into single phagosomes in alveolar macrophages (AMs). Phagosomal Cl- concentration and acidification magnitude were followed in real time with maximal acidification achieved at levels of approximately 200 mM. Live cell confocal microscopy verified that phagosomal Cl- influx utilized predominantly the Cl- channel CFTR. Relative levels of elemental chlorine (Cl) in hard X-ray fluorescence microprobe (XFM) analysis within single phagosomes validated the increase in Cl- content. XFM revealed the complex interplay between elemental K content inside the phagosome and changes in Cl- during phagosomal particle uptake. Cl- -dependent changes in phagosomal membrane potential were obtained using second harmonic generation (SHG) microscopy. These studies provide a mechanistic insight for screening studies in drug development targeting pulmonary inflammatory disease.

Real time imaging of single extracellular vesicle pH regulation in a microfluidic cross-flow filtration platform.

Extracellular vesicles (EVs) are cell-derived membranous structures carrying transmembrane proteins and luminal cargo. Their complex cargo requires pH stability in EVs while traversing diverse body fluids. We used a filtration-based platform to capture and stabilize EVs based on their size and studied their pH regulation at the single EV level. Dead-end filtration facilitated EV capture in the pores of an ultrathin (100 nm thick) and nanoporous silicon nitride (NPN) membrane within a custom microfluidic device. Immobilized EVs were rapidly exposed to test solution changes driven across the backside of the membrane using tangential flow without exposing the EVs to fluid shear forces. The epithelial sodium-hydrogen exchanger, NHE1, is a ubiquitous plasma membrane protein tasked with the maintenance of cytoplasmic pH at neutrality. We show that NHE1 identified on the membrane of EVs is functional in the maintenance of pH neutrality within single vesicles. This is the first mechanistic description of EV function on the single vesicle level.

Support and attitudes of Qatar mental health professionals to a proposed mental health inpatient smoking ban: Results of a cross-sectional survey.

WHAT IS KNOWN ON THE SUBJECT?: Smoking is more common among people with serious mental illness, and it contributes to a reduced life expectancy. Several Western countries have successfully introduced smoke-free policies in inpatient mental health units. There is virtually no information about attitudes to smoking bans in mental health units from countries in the Middle East and North Africa region. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: We surveyed mental health professionals working in Qatar's main mental health service to determine support for and attitudes towards a proposed total smoking ban in psychiatric wards. Most staff who completed the survey supported an inpatient smoking ban. However, further analysis, both quantitative and qualitative, showed markedly ambivalent attitudes, that is staff simultaneously held attitudes that supported and opposed a smoking ban. Professionals who did not support a ban were more likely to have not received smoking cessation training in the last 5 years, to be a psychiatrist rather than a nurse or allied mental health professional, to be current smokers and to be a Middle Eastern and North African national. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Further staff training is necessary to achieve more consistent attitudes that support a total smoking ban and increase the likelihood of successful implementation. The attitudes in this study showed similarities and differences to those reported for mental health professionals in Western countries. This highlights that local research is necessary to help shape training and successfully implement smoke-free policies. ABSTRACT: Introduction Despite the fact that patients with serious mental illness (SMI) have high rates of smoking and an increased standardized mortality, there is virtually no information about attitudes to smoking bans in mental health units from countries in the Middle East and North Africa region. Aim To assess support for, and attitudes towards, a proposed total smoking ban in psychiatric wards among mental health clinicians in Qatar. Method Cross-sectional survey of mental health professionals working in Qatar's primary mental health service. Results The response rate was 68% (353/520). Support for a ban was assessed with a single-item question; 73% of respondents supported a ban with opposition significantly (p < .05) associated with being a current smoker, a Middle Eastern and North African (MENA) national, a psychiatrist versus a mental health nurse or allied health professional and not receiving smoking cessation training in the last 5 years. A 21-item questionnaire assessed attitudes to a total smoking ban. It showed marked ambivalence with multiple linear regression identifying MENA nationality, male gender and current smoking status as independent variables influencing attitudes. The most strongly held attitude supporting a ban was concern about passive smoking and against a ban was concern it may increase patient agitation. Qualitative data confirmed ambivalent views. Discussion The results show similarities and differences to research from other countries suggesting that cultural factors influence some attitudes to smoke-free policies. Implications for Practice Staff support and smoking cessation education are necessary to achieve more consistent staff attitudes to support smoke-free policies.

Psychiatric inpatients' views of their mental health, and their experience of social change, during the pandemic: A report from Qatar.

WHAT IS KNOWN ON THE SUBJECT?: There is only limited information on how the COVID-19 pandemic has affected people diagnosed with mental health disorders, especially people admitted to psychiatric wards. We surveyed the views of inpatients at Qatar's only psychiatric hospital regarding how the pandemic had affected their mental health and social changes they had experienced during the pandemic. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: Nearly half (43%) of those who completed the survey reported that the pandemic had led to a deterioration in their mental health. Those who reported deterioration in their mental health during the pandemic were significantly more likely to have experienced negative social changes during the pandemic. Examples included increased stress from the home and reduced ability to discuss emotions/feelings with family members. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Mental health services need to ensure ongoing support for patients during and after the pandemic. Mental health nurses have a pivotal role including identifying early warning signs of relapse of mental disorders, delivering talking treatments and providing practical advice and COVID-19-related education. Further work is needed to assess the views of people diagnosed with mental health problems in different countries and at a different time point during the pandemic. ABSTRACT: Introduction The impact of the COVID-19 pandemic on people under the care of mental health services has received relatively little attention in the scientific literature. Aim To assess psychiatric inpatients' views regarding their mental health and experience of social change during the pandemic. Method Cross-sectional survey of consecutive patients admitted to Qatar's only psychiatric hospital between mid-June and mid-October 2020. Results Data were analysed for 114/284 (40%) patients admitted during the study period. 8 (7%) reported a history of COVID-19. 43% reported that the pandemic had led to deterioration in their mental health, 11% to an improvement and 39% that there had been no attributable change. Those reporting worsened mental health, attributable to the pandemic, were significantly more likely to report having experienced four negative social changes during the pandemic, namely reduced ability to discuss emotions/feelings with family members, decreased time spent exercising, decreased time spent relaxing and increased stress from the home. Demographic factors did not distinguish those reporting worsened mental health from those whose mental health was improved or unchanged. Discussion A large proportion of psychiatric inpatients reported negative social and mental health changes during the pandemic. However, the study cannot determine causality. Implications for practice Mental health services should consider the psychological and social aspects of people's lives, including their interactions with family, friends and the community. This is especially relevant during the COVID-19 pandemic due to its wide impact on society. Interventions for people diagnosed with mental health disorders should address their psychological and social needs.

Growth and mineralization of osteoblasts from mesenchymal stem cells on microporous membranes: Epithelial-like growth with transmembrane resistance and pH gradient.

Osteoblasts in vivo form an epithelial-like layer with tight junctions between cells. Bone formation involves mineral transport into the matrix and acid transport to balance pH levels. To study the importance of the pH gradient in vitro, we used Transwell inserts composed of polyethylene terephthalate (PET) membranes with 0.4 µm pores at a density of (2 ± 0.4) x 106 pores per cm2. Mesenchymal stem cells (MSCs) prepared from murine bone marrow were used to investigate alternative conditions whereby osteoblast differentiation would better emulate in vivo bone development. MSCs were characterized by flow cytometry with more than 90% CD44 and 75% Sca-1 labeling. Mineralization was validated with paracellular alkaline phosphatase activity, collagen birefringence, and mineral deposition confirming MSCs identity. We demonstrate that MSCs cultured and differentiated on PET inserts form an epithelial-like layer while mineralizing. Measurement of the transepithelial resistance was ∼1400 Ω•cm2 at three weeks of differentiation. The pH value of the media above and under the cells were measured while cells were in proliferation and differentiation. In mineralizing cells, a difference of 0.145 pH unit was observed between the medium above and under the cells indicating a transepithelial gradient. A significant difference in pH units was observed between the medium above and below the cells in proliferation compared to differentiation. Data on pH below membranes were confirmed by pH-dependent SNARF1 fluorescence. Control cells in proliferative medium did not form an epithelial-like layer, displayed low transepithelial resistance, and there was no significant pH gradient. By transmission electron microscopy, membrane attached osteoblasts in vitro had abundant mitochondria consistent with active transport that occurs in vivo by surface osteoblasts. In keeping with osteoblastic differentiation, scanning electron microscopy identified deposition of extracellular collagen surrounded by hydroxyapatite. This in vitro model is a major advancement in modeling bone in vivo for understanding of osteoblast bone matrix production.

Psychological impact of the COVID-19 pandemic within institutional quarantine and isolation centres and its sociodemographic correlates in Qatar: a cross-sectional study.

SETTING: The State of Qatar has had one of the highest COVID-19 infection rates globally and has used state-managed quarantine and isolation centres to limit the spread of infection. Quarantine and isolation have been shown to negatively affect the mental health of individuals. Qatar has a unique population, with around 90% of the population being economic migrants and a majority being blue-collar workers and labourers. OBJECTIVES: This study was carried out to evaluate the psychological impact of institutional isolation and quarantine during the COVID-19 pandemic outbreak in Qatar. The study also explored the sociodemographic correlates of this psychological impact. DESIGN, PARTICIPANTS AND INTERVENTION: A cross-sectional study involving 748 consenting individuals in institutional quarantine and isolation in Qatar during the months of June and July 2020 was carried out. Relevant sociodemographic data along with depressive and anxiety symptomatology scores were collected from consenting adults at these facilities. RESULTS: 37.4% (n=270) of respondents reported depressive symptoms and 25.9% (n=189) reported anxiety symptoms. The scores were higher for individuals in isolation facilities and higher for migrants from poor socioeconomic group (p<0.001 for both). Within this group, although worries about infection were widely reported, lack of contact with the family was cited as one of the most important sources of distress. Respondents reported that contact with the family and reliable information were important factors that helped during the duration of isolation and quarantine. CONCLUSIONS: Our study reported significantly elevated scores for depression and anxiety during institutional quarantine, which is in keeping with emerging evidence. However, in contrast to other studies reporting mostly from native populations, this study of a population with an overwhelming majority of immigrants highlights the special mental health needs of this specific group and can inform future healthcare policies.

Gender Differences in Authorship in Urology: a Five-year Review of Publications in Five High-impact Journals.

OBJECTIVE: To describe the proportions of peer-reviewed manuscripts authored by women in 5 high-impact, widely available urology journals, and to compare these to the proportion of women in urology. About 9% of attending urologists and 25% of urology residents are women. We hypothesized that women comprised fewer than 25% of first authors and fewer than 10% of last/senior authors. METHODS: We searched peer-reviewed original manuscripts in the Journal of Urology, Journal of Pediatric Urology, Neurourology and Urodynamics, Urology, and Urologic Oncology from January 2014 to June 2019. First and last author gender identity was recorded. Observed and expected proportions and temporal trends were compared, with findings considered statistically significant at P < .05. RESULTS: Of 8653 multiple-author papers, 2275 (26.3%) had women as first authors, paralleling the current proportion of women in training (P = .98). Women were senior/last authors in 1255 (14.5%) papers; this was higher than the current proportion of female urologists in practice (P < .0001) for all journals but NAU (P = .59). Only 527 (6.1%) of multiple-author papers had both female first and last authors whereas 5640 (65.3%) of papers had both male first and last authors. The first author was more likely female when the senior author was female (OR = 2.34, 95% CI: 2.06-2.65); most female-first and -last authored manuscripts were published in subspecialty journals and those utilizing double-blind peer review. CONCLUSION: The proportion of female first- and senior-authored manuscripts is significantly higher than the proportion of women in urology, and may reflect differential subspecialty choices and mentorship opportunities for women.

Kinetic Separation of Oxidative and Non-oxidative Metabolism in Single Phagosomes from Alveolar Macrophages: Impact on Bacterial Killing.

The relative contribution of the two phagosomal catabolic processes, oxidative and metabolic, was assessed in the killing of Pseudomonas aeruginosa in phagosomes of alveolar macrophages (AMs) from wild-type (p47-phox +/+ ) or NOX-defective (p47-phox -/- ) mice. Free radical release and degradative acidification within AM phagosomes is sequential and separable. The initial NOX activity, identifiable as a transient alkalinization, leads to fast bacterial wall permeabilization by ROS. This is followed by V-ATPase-induced acidification and enzymatic bacterial degradation contributed through phagosomal-lysosomal fusion. The alkalinization/acidification ratio was variable among phagosomes within single cells of a given genotype and not as a function of macrophage M1 or M2 classification, possibly owing to uneven distribution of phagosomal transporter proteins. Irregular, excessive NOX activity prevents phago-lysosomal fusion, and the lack of V-ATPase-induced acidification leads to bacterial stasis in the phagosome. Thus, efficient phagosomal bacterial killing is a result of tightly balanced activity between two processes.

Phylogeny and chemistry of biological mineral transport.

Three physiologically mineralizing tissues - teeth, cartilage and bone - have critical common elements and important evolutionary relationships. Phylogenetically the most ancient densely mineralized tissue is teeth. In jawless fishes without skeletons, tooth formation included epithelial transport of phosphates, a process echoed later in bone physiology. Cartilage and mineralized cartilage are skeletal elements separate from bone, but with metabolic features common to bone. Cartilage mineralization is coordinated with high expression of tissue nonspecific alkaline phosphatase and PHOSPHO1 to harvest available phosphate esters and support mineralization of collagen secreted locally. Mineralization in true bone results from stochastic nucleation of hydroxyapatite crystals within the cross-linked collagen fibrils. Mineral accumulation in dense collagen is, at least in major part, mediated by amorphous aggregates - often called Posner clusters - of calcium and phosphate that are small enough to diffuse into collagen fibrils. Mineral accumulation in membrane vesicles is widely suggested, but does not correlate with a definitive stage of mineralization. Conversely mineral deposition at non-physiologic sites where calcium and phosphate are adequate has been shown to be regulated in large part by pyrophosphate. All of these elements are present in vertebrate bone metabolism. A key biological element of bone formation is an epithelial-like cellular organization which allows control of phosphate, calcium and pH during mineralization.

Assessment of Health Care Exposures and Outcomes in Adult Patients With Sepsis and Septic Shock.

Importance: Current information on the characteristics of patients who develop sepsis may help in identifying opportunities to improve outcomes. Most recent studies of sepsis epidemiology have focused on changes in incidence or have used administrative data sets that provided limited patient-level data. Objective: To describe sepsis epidemiology in adults. Design, Setting, and Participants: This retrospective cohort study reviewed the medical records, death certificates, and hospital discharge data of adult patients with sepsis or septic shock who were discharged from the hospital between October 1, 2014, and September 30, 2015. The convenience sample was obtained from hospitals in the Centers for Disease Control and Prevention Emerging Infections Program in 10 states (California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee). Patients 18 years and older with discharge diagnosis codes for severe sepsis or septic shock were randomly selected. Data were analyzed between May 1, 2018, and January 31, 2019. Main Outcomes and Measures: The population's demographic characteristics, health care exposures, and sepsis-associated infections and pathogens were described, and risk factors for death within 30 days after sepsis diagnosis were assessed. Results: Among 1078 adult patients with sepsis (569 men [52.8%]; median age, 64 years [interquartile range, 53-75 years]), 973 patients (90.3%) were classified as having community-onset sepsis (ie, sepsis diagnosed within 3 days of hospital admission). In total, 654 patients (60.7%) had health care exposures before their hospital admission for sepsis; 260 patients (24.1%) had outpatient encounters in the 7 days before admission, and 447 patients (41.5%) received medical treatment, including antimicrobial drugs, chemotherapy, wound care, dialysis, or surgery, in the 30 days before admission. A pathogen associated with sepsis was found in 613 patients (56.9%); the most common pathogens identified were Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Clostridioides difficile. After controlling for other factors, an association was found between underlying comorbidities, such as cirrhosis (odds ratio, 3.59; 95% CI, 2.03-6.32), immunosuppression (odds ratio, 2.52; 95% CI, 1.81-3.52), vascular disease (odds ratio, 1.54; 95% CI, 1.10-2.15), and 30-day mortality. Conclusions and Relevance: Most adults experienced sepsis onset outside of the hospital and had recent encounters with the health care system. A sepsis-associated pathogen was identified in more than half of patients. Future efforts to improve sepsis outcomes may benefit from examination of health maintenance practices and recent health care exposures as potential opportunities among high-risk patients.

Cellular and extracellular matrix of bone, with principles of synthesis and dependency of mineral deposition on cell membrane transport.

Bone differs from other connective tissues; it is isolated by a layer of osteoblasts that are connected by tight and gap junctions. This allows bone to create dense lamellar type I collagen, control pH, mineral deposition, and regulate water content forming a compact and strong structure. New woven bone formed after degradation of mineralized cartilage is rapidly degraded and resynthesized to impart structural order for local bone strength. Ossification is regulated by thickness of bone units and by patterning via bone morphogenetic receptors including activin, other bone morphogenetic protein receptors, transforming growth factor-ß receptors, all part of a receptor superfamily. This superfamily interacts with receptors for additional signals in bone differentiation. Important features of the osteoblast environment were established using recent tools including osteoblast differentiation in vitro. Osteoblasts deposit matrix protein, over 90% type I collagen, in lamellae with orientation alternating parallel or orthogonal to the main stress axis of the bone. Into this organic matrix, mineral is deposited as hydroxyapatite. Mineral matrix matures from amorphous to crystalline hydroxyapatite. This process includes at least two-phase changes of the calcium-phosphate mineral as well as intermediates involving tropocollagen fibrils to form the bone composite. Beginning with initiation of mineral deposition, there is uncertainty regarding cardinal processes, but the driving force is not merely exceeding the calcium-phosphate solubility product. It occurs behind a epithelial-like layer of osteoblasts, which generate phosphate and remove protons liberated during calcium-phosphate salt deposition. The forming bone matrix is discontinuous from the general extracellular fluid. Required adjustment of ionic concentrations and water removal from bone matrix are important details remaining to be addressed.

Estimating Risk to Responders Exposed to Avian Influenza A H5 and H7 Viruses in Poultry, United States, 2014-2017.

In the United States, outbreaks of avian influenza H5 and H7 virus infections in poultry have raised concern about the risk for infections in humans. We reviewed the data collected during 2014-2017 and found no human infections among 4,555 exposed responders who were wearing protection.

Toxin Enzyme Immunoassays Detect Clostridioides difficile Infection With Greater Severity and Higher Recurrence Rates.

BACKGROUND: Few data suggest that Clostridioides difficile infections (CDIs) detected by toxin enzyme immunoassay (EIA) are more severe and have worse outcomes than those detected by nucleic acid amplification tests (NAATs) only. We compared toxin- positive and NAAT-positive-only CDI across geographically diverse sites. METHODS: A case was defined as a positive C. difficile test in a person ≥1 year old with no positive tests in the prior 8 weeks. Cases were detected during 2014-2015 by a testing algorithm (specimens initially tested by glutamate dehydrogenase and toxin EIA; if discordant results, specimens were reflexed to NAAT) and classified as toxin positive or NAAT positive only. Medical charts were reviewed. Multivariable logistic regression models were used to compare CDI-related complications, recurrence, and 30-day mortality between the 2 groups. RESULTS: Of 4878 cases, 2160 (44.3%) were toxin positive and 2718 (55.7%) were NAAT positive only. More toxin-positive than NAAT-positive-only cases were aged ≥65 years (48.2% vs 38.0%; P < .0001), had ≥3 unformed stools for ≥1 day (43.9% vs 36.6%; P < .0001), and had white blood cell counts ≥15 000 cells/µL (31.4% vs 21.4%; P < .0001). In multivariable analysis, toxin positivity was associated with recurrence (adjusted odds ratio [aOR], 1.89; 95% confidence interval [CI], 1.61-2.23), but not with CDI-related complications (aOR, 0.91; 95% CI, .67-1.23) or 30-day mortality (aOR, 0.95; 95% CI, .73-1.24). CONCLUSIONS: Toxin-positive CDI is more severe, but there were no differences in adjusted CDI-related complication and mortality rates between toxin-positive and NAAT-positive-only CDI that were detected by an algorithm that utilized an initial glutamate dehydrogenase screening test.

Predictors of decreased libido in women during the late reproductive years.

OBJECTIVE: To identify risk factors for decreased libido among women in the late reproductive years. DESIGN: Prospective cohort. Women aged 35 to 47 years identified through random digit dialing were prospectively followed for 4 years with serial hormone assays and standardized questionnaires. Mean hormone values, hormone trends over 4 years, and fluctuation in hormone levels were compared among women with and without a decrease in libido at the last assessment period. Total testosterone, dihydroepiandrosterone sulfate, estradiol, follicle-stimulating hormone, luteinizing hormone, body mass index, psychosocial, and socioeconomic variables were evaluated using multivariable logistic regression. RESULTS: Of 326 women, 87 (27%) reported a decreased libido, whereas 239 (73%) did not. Participant-specific means for all hormone levels over the study period were similar among both groups. However, total testosterone fluctuation over the study was significantly different between groups. Women whose testosterone levels fluctuated from 3.8 to 21.5 ng/dL around a mean value of 9 ng/dL were four times more likely to report decreased libido compared with women with little fluctuation in testosterone [odds ratio (OR) 4.0; 95% CI, 1.6-10.0]. Depression (OR 3.4; 95%CI, 1.9-6.1), vaginal dryness (OR 3.5; 95%CI, 1.8-6.6), and children living at home (OR 1.4; 95%CI, 1.1-1.7) were also independently associated with decreased libido. CONCLUSIONS: Decreased libido in the late reproductive years is associated with a pronounced fluctuation in total testosterone over time. Other independent risk factors for decreased libido include vaginal dryness, depression, and living with children. Sexual dysfunction is a complex disorder, related to physiological and psychosocial factors, requiring further investigation.

Identification of Approaches to Improve Patient Trust in Health Systems: A Group Concept Mapping Study.

EXECUTIVE SUMMARY: Higher levels of institutional trust have been associated with increased preventive healthcare use, greater adherence to treatment plans, and improved overall self-rated health status. However, little attention has been paid to understanding approaches to improve patient institutional trust. This study used group concept mapping to elicit patient perspectives on ways to improve patient trust. Eighteen insured individuals living in Delaware County, Pennsylvania, participated in the concept mapping sessions. Participants first brainstormed in a group setting to develop a list of ideas about how systems could improve trust, then each participant sorted the ideas into thematic domains and rated the statements based on both importance and feasibility. Four primary domains for improving institutional trust emerged: privacy, patient-provider relationship, respect for patients, and health system guidelines. Multiple action items to improve patient trust of the system were provided for each domain, and participants rated the "privacy" domain as the most feasible and important to address.We suggest that future local efforts to build institutional trust implement processes to improve the protection of patient privacy, support patient-provider relationships, and engender respect for patients, and that institutions develop system-level guidelines to support these principles. Next steps involve exploring the importance of these domains across other populations and developing and testing targeted interventions.

Support of bone mineral deposition by regulation of pH.

Osteoblasts secrete collagen and isolate bone matrix from extracellular space. In the matrix, alkaline phosphatase generates phosphate that combines with calcium to form mineral, liberating 8 H+ per 10 Ca+2 deposited. However, pH-dependent hydroxyapatite deposition on bone collagen had not been shown. We studied the dependency of hydroxyapatite deposition on type I collagen on pH and phosphate by surface plasmon resonance in 0-5 mM phosphate at pH 6.8-7.4. Mineral deposition saturated at <1 mM Ca2+ but was sensitive to phosphate. Mineral deposition was reversible, consistent with amorphous precipitation; stable deposition requiring EDTA removal appeared with time. At pH 6.8, little hydroxyapatite deposited on collagen; mineral accumulation increased 10-fold at pH 7.4. Previously, we showed high expression Na+/H+ exchanger (NHE) and ClC transporters in osteoblasts. We hypothesized that, in combination, these move protons across osteoblasts to the general extracellular space. We made osteoblast membrane vesicles by nitrogen cavitation and used acridine orange quenching to characterize proton transport. We found H+ transport dependent on gradients of chloride or sodium, consistent with apical osteoblast ClC family Cl-,H+ antiporters and basolateral osteoblast NHE family Na+/H+ exchangers. Little, if any, active H+ transport, supported by ATP, occurred. Major transporters include cariporide-sensitive NHE1 in basolateral membranes and ClC3 and ClC5 in apical osteoblast membranes. The mineralization inhibitor levamisole reduced bone formation and expression of alkaline phosphatase, NHE1, and ClC5. We conclude that mineral deposition in bone collagen is pH-dependent, in keeping with H+ removal by Cl-,H+ antiporters and Na+/H+-exchangers. Periodic orientation hydroxyapatite is organized on type I collagen-coiled coils.