Thoracic Ultrasound Utility in Pulmonary Pathologies Following Blunt Chest Trauma: A Cross-Sectional Study From Barcelona, Venezuela.

Background The thoracic ultrasound (TUS) is a monitoring tool that has gained worldwide popularity in various scenarios, offering the opportunity for dynamic, bedside evaluations. Recent studies indicate that the use of TUS enables the diagnosis of pathologies resulting from blunt chest trauma (BCT), yielding favorable outcomes. This study aimed to compare the utility of TUS versus chest radiography (CXR) in diagnosing pulmonary pathologies resulting from closed-chest traumas. Methodology A prospective cross-sectional study was conducted with a sample of 58 patients diagnosed with BCT who sought emergency care at the "Dr. Luis Razetti" University Hospital in Barcelona, Venezuela, from November 2023 to January 2024. Results Of the patients, 75.9% (n = 44) were male, with an average age of 37.8 years (standard deviation = 18.4 years). Injuries were reported in 8.6% (n = 5) of the patients, including 60% (n = 3) pneumothorax and 40% (n = 2) hemothorax. Ultrasound results coincided with CXR in 94.8% (n = 55) of the cases, with a Cohen's kappa coefficient of 0.9 (95% confidence interval (CI) = 0.642-1.0). TUS demonstrated higher sensitivity than CXR (100% vs. 60%) for detecting hemothorax and pneumothorax in patients with BCT, with an area under the receiver operating characteristic curve of 0.991 (95% CI = 0.968-1.013). Conclusions BCT predominantly occurred in young males, resulting primarily in pneumothorax and hemothorax lesions, detectable with higher sensitivity through TUS compared to CXR. The use of TUS should be considered an essential component of the initial assessment for individuals with BCT.

Isolation and Annotation of Xitlalli, a Cluster EK1 Actinobacteriophage Isolated Using Microbacterium foliorum.

Xitlalli is an actinobacteriophage that was isolated from soil using Microbacterium foliorum. Based on gene content similarity to phages in the Actinobacteriophage Database, Xitlalli is assigned to cluster EK1. The genome is 53,929 bp long and contains 52 protein-coding genes, of which 26% could be assigned functions.

Migrating Type 2 Dendritic Cells Prime Mucosal Th17 Cells Specific to Small Intestinal Commensal Bacteria.

Dendritic cells (DCs) are professional APCs equipped with MHC-restricted Ags, costimulations, and cytokines that effectively prime and differentiate naive T cells into distinct functional subsets. The immune signals that DCs carry reflect the route of Ag uptake and the innate stimuli they received. In the mucosal tissues, owing to the great variety of foreign Ags and inflammatory cues, DCs are predominantly activated and migratory. In the small intestine, CD4 Th17 cells are abundant and have been shown to be regulated by DCs and macrophages. Using a mouse commensal bacteria experimental model, we identified that the early priming step of commensal-driven Th17 cells is controlled by bona fide Zbtb46-expressing DCs. CCR7-dependent migration of type 2 DCs (DC2s) from the small intestine to the mesenteric lymph nodes (MLNs) is essential for the activation of naive CD4 T cells. The migratory DC2 population in the MLNs is almost exclusively Esam+ cells. Single-cell RNA sequencing highlighted the abundance of costimulatory markers (CD40 and OX40) and chemokines (Ccl22 and Cxcl16) on MLN migratory DCs. Further resolution of MLN migratory DC2s revealed that the Th17-polarizing cytokine IL-6 colocalizes with DC2s expressing CD40, Ccl17, and Ccl22. Thus, early Th17 cell differentiation is initiated by a small subset of migratory DC2s in the gut-draining lymph nodes.

Keeping your coparent in mind: A longitudinal investigation of mindfulness in the family system.

Recent studies have increasingly focused on mindfulness as it relates to interpersonal processes. In particular, cross-sectional research has shown that parents' dispositional mindfulness is associated with increased mindful parenting and coparenting, as well as improved coparenting relationship quality. The current study replicates and extends such work, representing the first longitudinal investigation of mindful coparenting. A sample of 449 parents (60% mothers) of children between the ages of 3 and 17 years were recruited online through Amazon's Mechanical Turk (MTurk) as part of a larger study on the assessment of parenting. Parents reported on their dispositional mindfulness, mindful coparenting, and coparenting relationship quality at three time points across an 8-month period. Results from a cross-lagged panel model using maximum likelihood estimation suggested that higher levels of parental mindfulness at baseline were related with higher levels of mindful coparenting at 4 months, which, in turn, were related to higher quality coparenting relationship at 8 months. Support for this model was found for both mothers and fathers and across all examined child age groups (i.e., early childhood, middle childhood, and adolescence), highlighting the robust nature of these effects. Overall, findings suggest that increasing mindfulness at an individual level can promote meaningful change within a family system, specifically through improvements in coparenting and parent-child interactions.

Los estudios recientes se han centrado cada vez más en la conciencia plena en relación con los procesos interpersonales. En particular, las investigaciones transversales han demostrado que la conciencia plena disposicional de los padres está asociada con una crianza y una cocrianza más conscientes, así como con una mejor calidad de la relación de cocrianza. El presente estudio reproduce y amplía dicho trabajo, y representa la primera investigación longitudinal de cocrianza consciente. Se reunió virtualmente una muestra de 449 padres (el 60 % madres) de niños de entre 3 y 17 años mediante Amazon's Mechanical Turk (MTurk) como parte de un estudio más extenso sobre la evaluación de la crianza. Los padres informaron sobre su conciencia plena disposicional, la cocrianza consciente y la calidad de la relación de cocrianza en tres intervalos de tiempo durante un periodo de ocho meses. Los resultados de un modelo de panel de retardo cruzado utilizando la estimación por máxima verosimilitud indicaron que los niveles más altos de conciencia plena de los padres en el momento basal estuvieron relacionados con niveles más altos de cocrianza consciente a los cuatro meses, los cuales, a su vez, estuvieron relacionados con una relación de cocrianza de mayor calidad a los ocho meses. Se encontró respaldo para este modelo tanto en el caso de las madres como en el de los padres y entre todos los grupos etarios de los niños analizados (p. ej.: primera infancia, segunda infancia, adolescencia). Asimismo, se destacó la índole sólida de estos efectos. En general, los resultados indican que aumentar la conciencia plena a nivel individual puede promover un cambio significativo dentro de un sistema familiar, específicamente mediante mejoras en la cocrianza y en las interacciones entre padres e hijos.

Disruption of a key ligand-H-bond network drives dissociative properties in vamorolone for Duchenne muscular dystrophy treatment.

Duchenne muscular dystrophy is a genetic disorder that shows chronic and progressive damage to skeletal and cardiac muscle leading to premature death. Antiinflammatory corticosteroids targeting the glucocorticoid receptor (GR) are the current standard of care but drive adverse side effects such as deleterious bone loss. Through subtle modification to a steroidal backbone, a recently developed drug, vamorolone, appears to preserve beneficial efficacy but with significantly reduced side effects. We use combined structural, biophysical, and biochemical approaches to show that loss of a receptor-ligand hydrogen bond drives these remarkable therapeutic effects. Moreover, vamorolone uniformly weakens coactivator associations but not corepressor associations, implicating partial agonism as the main driver of its dissociative properties. Additionally, we identify a critical and evolutionarily conserved intramolecular network connecting the ligand to the coregulator binding surface. Interruption of this allosteric network by vamorolone selectively reduces GR-driven transactivation while leaving transrepression intact. Our results establish a mechanistic understanding of how vamorolone reduces side effects, guiding the future design of partial agonists as selective GR modulators with an improved therapeutic index.

Evaluation of Manualized Instruction to Train Staff to Implement a Token Economy.

All components of behavioral skills training may not be necessary to effectively train staff to implement behavior-analytic technologies with children with disabilities. This study evaluated manualized instruction to train inexperienced staff to implement a token economy with a confederate and collect data on learner responding. A nonconcurrent multiple-baseline design across staff trainees was used to evaluate the effectiveness of manualized instruction to increase the staff trainees' accurate implementation of a token economy. Additionally, a modified general case analysis was conducted to identify potential child behaviors. Multiple-exemplar training of these behaviors was presented in random order during sessions. Following the use of the manualized instruction, staff trainees' accurate implementation of a token economy and data collection on confederate responding increased, the skills generalized from a confederate to a child with autism spectrum disorder, and the skills maintained 1 month following training.

Cutting Edge: Targeting Thrombocytes to Rewire Anticancer Immunity in the Tumor Microenvironment and Potentiate Efficacy of PD-1 Blockade.

Aside from their roles in hemostasis and thrombosis, thrombocytes or platelets also promote tumor growth via immune suppression. However, the extent to which platelet activation shapes the immunosuppressive tumor microenvironment (TME) and whether platelet inhibition can be leveraged to improve checkpoint blockade are unknown. We show in this study that platelet function in mice mediates suppression of CD8+ T cell function within the TME but not in the draining lymph nodes. Tempering platelet activation genetically reduced TGF-ß signaling in both immune and nonimmune cells in the TME, enhanced T cell frequency and function, and decreased CD11b+ myeloid cell infiltration in the tumor. Targeting platelet function pharmacologically in tumor-bearing mice with aspirin and clopidogrel in combination with PD-1 blockade improved tumor control. These results suggest that platelet function represents a continuous, supplemental mechanism of immune evasion co-opted by tumors to evade antitumor immunity and offers an attractive target for combination with immunotherapy.

A Platform To Enhance Quantitative Single Molecule Localization Microscopy.

Quantitative single molecule localization microscopy (qSMLM) is a powerful approach to study in situ protein organization. However, uncertainty regarding the photophysical properties of fluorescent reporters can bias the interpretation of detected localizations and subsequent quantification. Furthermore, strategies to efficiently detect endogenous proteins are often constrained by label heterogeneity and reporter size. Here, a new surface assay for molecular isolation (SAMI) was developed for qSMLM and used to characterize photophysical properties of fluorescent proteins and dyes. SAMI-qSMLM afforded robust quantification. To efficiently detect endogenous proteins, we used fluorescent ligands that bind to a specific site on engineered antibody fragments. Both the density and nano-organization of membrane-bound epidermal growth factor receptors (EGFR, HER2, and HER3) were determined by a combination of SAMI, antibody engineering, and pair-correlation analysis. In breast cancer cell lines, we detected distinct differences in receptor density and nano-organization upon treatment with therapeutic agents. This new platform can improve molecular quantification and can be developed to study the local protein environment of intact cells.

Determinación de factores de adhesión asociados a la formación de biopelícula en aislamientos clínicos de Staphylococcus aureus y Staphylococcus epidermidis / Determination of adhesion factors associated with biofilm formation in clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis

Resumen Los factores de adhesión son determinantes de virulencia que se expresan en microorganismos que tienen la capacidad de formar biopelícula, contribuyendo a la gravedad de infecciones intrahospitalarias. Dentro de estos componentes de la superficie microbiana que reconocen moléculas de adhesión de matriz conocidas como MSCRAMMs, se incluyen el factor de unión a fibronectina A y B, (FnbA y B) factor de aglutinación A y B (ClfA y B) y factor de unión a fibrinógeno (Fib), que se han descrito en Staphylococcus aureus y reaccionan con proteínas de la matriz extracelular humana. El objetivo de este estudio fue determinar la presencia de estos factores de adhesión relacionados con la formación de biopelicula en Staphylococcus. Método. Se caracterizaron fenotípica y genotípicamente 30 aislamientos clínicos de Staphylococcus aureus y Staphylococcus epidermidis, provenientes de pacientes inmunocomprometidos en tres instituciones hospitalarias de Bogotá. La producción de Biopelícula se determinó mediante Rojo Congo y Cristal violeta y mediante PCR convencional y múltiplex se amplificaron los genes FnbA y B, ClfA y B y Fib, así como los genes del operón ica ADBC. Resultados. Todos los aislamientos clínicos fueron positivos genotípica y fenotípicamente para la producción de Biopelícula, encontrándose la presencia del operón completo en el 88.9%, los factores ClfA y ClfB en un 70%; Fib en un 60%, FnbB en un 23% y FnbA en el 17%. Conclusiones. En este estudio se evidenció la presencia de estos factores de virulencia en S. epidermidis, los cuáles hasta el momento se han reportado únicamente en S.aureus. Este hallazgo es importante ya que se sugiere la relación con transferencia horizontal de genes entre estas especies, siendo el S. epidermidis un importante reservorio genético, y un importante patobionte causal de infecciones nosocomiales, asociado con dispositivos médicos.

Abstract Adhesion factors are virulence determinants that are expressed in microorganisms with the ability to form biofilms, contributing to the severity of nosocomial infections. Among these microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), are fibronectin binding A and B (fnbA and B) clumping A and B (ClfA and B) and fibrinogen binding (Fib) factors. All of these have been described in Staphylococcus aureus and react with human extracellular matrix proteins. The goal of this study was to determine adhesion factors related to the biofilm formation in Staphylococcus. Method. For these purpose, 30 clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis, from immunocompromised patients in three hospitals in Bogotá were characterized both, genotypically and phenotypically. The biofilm formation was determined through Congo Red and Violet Crystal and the genes FnbA, B, ClfA, B, Fib and operon ica ADBC were amplified through conventional and multiplex PCR. Results. Every clinical isolate were genotypically and phenotypically positive for the biofilm formation, being found the presence of the whole ica ADBC operon in 88,9%. The ClfA and ClfB were found by 70%; Fib 60%, fnbB 23% and 17% offnbA. Conclusions. This study proved the presence of these virulence factors in S. epidermidis, which so far have only been reported in S. aureus. This finding is important because it suggestes the relationship with horizontal gene transfer between these species, being the S. epidermidis an important genetic reservoir and a causal patobiont of nosocomial infections associated with medical devices.

Human Neural Stem Cell Biodistribution and Predicted Tumor Coverage by a Diffusible Therapeutic in a Mouse Glioma Model.

Engineered neural stem cells (NSCs) intrinsically migrating to brain tumors offer a promising mechanism for local therapeutic delivery. However, difficulties in quantitative assessments of NSC migration and in estimates of tumor coverage by diffusible therapeutics have impeded development and refinement of NSC-based therapies. To address this need, we developed techniques by which conventional serial-sectioned formalin-fixed paraffin-embedded (FFPE) brains can be analyzed in their entirety across multiple test animals. We considered a conventional human glioblastoma model: U251 glioma cells orthotopically engrafted in immunodeficient mice receiving intracerebral (i.c.) or intravenous (i.v.) administrations of NSCs expressing a diffusible enzyme to locally catalyze chemotherapeutic formation. NSC migration to tumor sites was dose-dependent, reaching 50%-60% of total administered NSCs for the i.c route and 1.5% for the i.v. route. Curiously, the most efficient NSC homing was seen with smaller NSC doses, implying existence of rate-limiting process active during administration and/or migration. Predicted tumor exposure to a diffusing therapeutic (assuming a 50 µm radius of action) could reach greater than 50% of the entire tumor volume for i.c. and 25% for i.v. administration. Within individual sections, coverage of tumor area could be as high as 100% for i.c. and 70% for i.v. routes. Greater estimated therapeutic coverage was observed for larger tumors and for larger tumor regions in individual sections. Overall, we have demonstrated a framework within which investigators may rationally evaluate NSC migration to, and integration into, brain tumors, and therefore enhance understanding of mechanisms that both promote and limit this therapeutic modality. Stem Cells Translational Medicine 2017;6:1522-1532.

The toxicity of methotrexate in male fertility and paternal teratogenicity.

INTRODUCTION: There is a high prevalence of methotrexate (MTX) use in males of reproductive age. The scope of this paper reviews what is known regarding risks to fertility and partners' pregnancy outcomes with regard to MTX use in men. Areas covered: This paper reviews the evidence for current recommendations for MTX use and male fertility and aims to educate professionals regarding MTX use in reproducing males so that patients may be counseled appropriately. A literature search included peer-reviewed sources from PubMed searches and the literature referenced within. Expert opinion: There is a lack of evidence regarding effects of MTX on male fertility. The recommendation to stop MTX three months prior to conception is safe, but is not evidenced by an understanding of the impact of MTX on spermatogenesis or paternal-mediated teratogenicity but rather the timeframe of spermatogenesis. Given the unclear evidence, patients treated with MTX must be counseled on the likelihood of adverse effects of MTX and role of sperm cryopreservation. Future studies are needed to help elucidate the unclear evidence of MTX effects on male fertility and pregnancy outcomes.

Characterizing Primary Care Visit Activities at Veterans Health Administration Clinics.

Medical home models seek to increase efficiency and maximize the use of resources by ensuring that all care team members work at the top of their licenses. We sought to break down primary care office visits into measurable activities to better under stand how primary care providers (PCPs) currently spend visit time and to provide insight into potential opportunities for revision or redistribution of healthcare tasks. We videotaped 27 PCPs during office visits with 121 patients at four Veterans Health Administration medical centers. Based on patterns emerging from the data, we identified a taxonomy of 12 provider activity categories that enabled us to quantify the frequency and duration of activities occurring during routine primary care visits. We conducted descriptive and multivariate analyses to examine associations between visit characteristics and provider and clinic characteristics. We found that PCPs spent the greatest percentage of their visit time discussing existing conditions (20%), discussing new conditions (18%), record keeping (13%), and examining patients (13%). Providers spent the smallest percentage of time on preventive care and coordination of care. Mean visit length was 22.9 minutes (range 7.9-58.0 minutes). Site-level ratings of medical home implementation were not associated with differences in how visit time was spent. These data provide a window into how PCPs are spending face-to-face time with patients. The methodology and taxonomy presented here may prove useful for future quality improvement and research endeavors, particularly those focused on opportunities to increase nonappointment care and to ensure that team members work at the top of their skill level.

Rethinking primary care visits: how much can be eliminated, delegated or performed outside of the face-to-face visit?

RATIONALE, AIMS AND OBJECTIVES: Office visits represent the core component of primary care practice, but little is known about what percentage of primary care provider (PCP) visit time could be suitable for reassignment to another medical home team member or to a non-face-to-face modality (e.g. secure messaging) in order to optimize face-to-face PCP visit time. METHOD: We videotaped 121 PCP office visits at four Veterans Health Administration Medical Centers and divided visits into discrete activity segments. Two physicians reviewed each visit recording and provided independent clinical judgments regarding which segments might be suitable for reassignment. We examined the activity category distribution of visit time rated as needing face-to-face time with a PCP. RESULTS: Reviewers judged 53% of the 5398 minutes of rated visit time as suitable for reassignment to another team member or modality. The percentage of time rated as needing face-to-face PCP care varied greatly by activity category, from a high of 73.9% (for examining patients) to a low of 16.2% (for medication review). Rater agreement regarding tasks' suitability for reassignment varied across activity categories. CONCLUSIONS: These data offer an example of how face-to-face PCP visit time might be optimized as practices seek to shift components of patient care to other team members and other modalities. Given variations in provider preferences and judgments, successful redesign efforts will need to involve stakeholders in decisions about how to best utilize medical home resources.

In vitro analysis regarding the safety of components used in a film-based therapeutic system loaded with meglumine antimoniate and its activity toward Leishmania major experimental infections: a preliminary study.

Owing to its biocompatibility properties and its ability to promote the scar healing process, chitosan is employed in tissue engineering for the manufacture of formulations. To control the characteristic skin ulcers of cutaneous leishmaniasis (CL), the use of a biopolymeric system that favors the scar healing process and releases an active agent such as meglumine antimoniate may be a better option. For these reasons, here we analyzed the cytotoxic capabilities of excipients [medium molecular weight chitosan (MMWC), lactic acid (LA) and polyvinylpyrrolidone (PVP)], used for the formulation of a film-based therapeutic system that releases meglumine antimoniate and were evaluated on human macrophages [monocyte-derived macrophages (MDMs)], L929 fibroblasts and parasites (Leishmania major promastigotes and intracellular amastigotes). The ability of excipients to modulate the cytokines production involved in the scar healing process was compared with film-based therapeutic system. The efficiency of a film-based therapeutic system loaded with meglumine antimoniate was compared with conventional formulation (Albiventriz(®)). We found that MMWC was toxic for two parasite forms. In contrast, measurement of interleukin levels did not show any evidence of preferential secretion as a side effect of treating human macrophages with MMWC. Finally, the efficiency of a polymeric film-based therapeutic system that was loaded with meglumine antimoniate could not be determined due to the high degree of toxicity observed in infected MDMs; moreover, these compounds do not induce any apparent immunomodulatory effects. Our findings suggest that the final concentrations of each excipients (MMWC, LA and PVP) that were used in the polymeric film were suitable vehicles for active pharmaceutical compound delivery and did not selectively affect (enhancing or diminishing immune activity) macrophages.

Isolation and characterization of a psychropiezophilic alphaproteobacterium.

Cultivated psychropiezophilic (low-temperature- and high-pressure-adapted) bacteria are currently restricted to phylogenetically narrow groupings capable of growth under nutrient-replete conditions, limiting current knowledge of the extant functional attributes and evolutionary constraints of diverse microorganisms inhabiting the cold, deep ocean. This study documents the isolation of a deep-sea bacterium following dilution-to-extinction cultivation using a natural seawater medium at high hydrostatic pressure and low temperature. To our knowledge, this isolate, designated PRT1, is the slowest-growing (minimal doubling time, 36 h) and lowest cell density-producing (maximal densities of 5.0 × 106 cells ml⁻¹) piezophile yet obtained. Optimal growth was at 80 MPa, correlating with the depth of capture (8,350 m), and 10°C, with average cell sizes of 1.46 µm in length and 0.59 µm in width. Through detailed growth studies, we provide further evidence for the temperature-pressure dependence of the growth rate for deep-ocean bacteria. PRT1 was phylogenetically placed within the Roseobacter clade, a bacterial lineage known for widespread geographic distribution and assorted lifestyle strategies in the marine environment. Additionally, the gene transfer agent (GTA) g5 capsid protein gene was amplified from PRT1, indicating a potential mechanism for increased genetic diversification through horizontal gene transfer within the hadopelagic environment. This study provides a phylogenetically novel isolate for future investigations of high-pressure adaptation, expands the known physiological traits of cultivated members of the Roseobacter lineage, and demonstrates the feasibility of cultivating novel microbial members from the deep ocean using natural seawater.

Reliability and validity of diabetes specific Health Beliefs Model scales in patients with diabetes and serious mental illness.

AIMS: In this study we evaluate the reliability and validity of existing Health Beliefs Model (HBM) scales developed to assess HBM domains in a population of patients with both diabetes and serious mental illness (SMI). While diabetes medication adherence has frequently been evaluated through the lens of the HBM, it is unclear if developed scales are reliable and valid in patients with SMI. METHODS: We surveyed 152 veterans with diabetes and SMI. Domains of the HBM assessed included perceived benefits, side effects and barriers to diabetes medication taking, perceived susceptibility to and severity of diabetes, diabetes self-efficacy, diabetes locus of control, and perceived diabetes control. RESULTS: HBM scales showed good internal reliability within a SMI population, with Cronbach alphas ranging between 0.73 and 0.86 for all scales assessed except one. HBM scales also showed associations with self reported diabetes medication adherences in six of the ten domains. CONCLUSION: Scales assessing diabetes specific domains of the HBM exhibit both reliability and validity in patients with both diabetes and SMI.

Cell wall synthesis is necessary for membrane dynamics during sporulation of Bacillus subtilis.

During Bacillus subtilis sporulation, an endocytic-like process called engulfment results in one cell being entirely encased in the cytoplasm of another cell. The driving force underlying this process of membrane movement has remained unclear, although components of the machinery have been characterized. Here we provide evidence that synthesis of peptidoglycan, the rigid, strength bearing extracellular polymer of bacteria, is a key part of the missing force-generating mechanism for engulfment. We observed that sites of peptidoglycan synthesis initially coincide with the engulfing membrane and later with the site of engulfment membrane fission. Furthermore, compounds that block muropeptide synthesis or polymerization prevented membrane migration in cells lacking a component of the engulfment machinery (SpoIIQ), and blocked the membrane fission event at the completion of engulfment in all cells. In addition, these compounds inhibited bulge and vesicle formation that occur in spoIID mutant cells unable to initiate engulfment, as did genetic ablation of a protein that polymerizes muropeptides. This is the first report to our knowledge that peptidoglycan synthesis is necessary for membrane movements in bacterial cells and has implications for the mechanism of force generation during cytokinesis.

SpoIID-mediated peptidoglycan degradation is required throughout engulfment during Bacillus subtilis sporulation.

SpoIID is a membrane-anchored enzyme that degrades peptidoglycan and is essential for engulfment and sporulation in Bacillus subtilis. SpoIID is targeted to the sporulation septum, where it interacts with two other proteins required for engulfment: SpoIIP and SpoIIM. We changed conserved amino acids in SpoIID to alanine to determine whether there was a correlation between the effect of each substitution on the in vivo and in vitro activities of SpoIID. We identified one amino acid substitution, E88A, that eliminated peptidoglycan degradation activity and one, D210A, that reduced it, as well as two substitutions that destabilized the protein in B. subtilis (R106A and K203A). Using these mutants, we show that the peptidoglycan degradation activity of SpoIID is required for the first step of engulfment (septal thinning), as well as throughout membrane migration, and we show that SpoIID levels are substantially above the minimum required for engulfment. The inactive mutant E88A shows increased septal localization compared to the wild type, suggesting that the degradation cycle of the SpoIID/SpoIIP complex is accompanied by the activity-dependent release of SpoIID from the complex and subsequent rebinding. This mutant is also capable of moving SpoIIP across the sporulation septum, suggesting that SpoIID binding, but not peptidoglycan degradation activity, is needed for relocalization of SpoIIP. Finally, the mutant with reduced activity (D210A) causes uneven engulfment and time-lapse microscopy indicates that the fastest-moving membrane arm has greater concentrations of SpoIIP than the slower-moving arm, demonstrating a correlation between SpoIIP protein levels and the rate of membrane migration.

Racial differences in expectations of joint replacement surgery outcomes.

OBJECTIVE: Prior studies have indicated racial differences in patients' expectations for joint replacement surgery outcomes. The goal of this study was to measure these differences using a well-validated survey instrument and to determine if the differences could be explained by racial variation in disease severity, socioeconomic factors, literacy, or trust. METHODS: Detailed demographic, clinical, psychological, and social data were collected from 909 male patients (450 African American, 459 white) ages 50-79 years with moderate or severe osteoarthritis (OA) of the hip or knee receiving primary care at 2 veterans affairs medical centers. The previously validated Joint Replacement Expectations Survey was used to assess expectations for pain relief, functional improvement, and psychological well-being after joint replacement. RESULTS: Among knee OA patients (n = 627), the unadjusted mean expectation score (scale 0-76) for African American patients was 48.7 versus 53.6 for white patients (mean difference 4.9, P < 0.001). For hip OA patients (n = 282), the unadjusted mean expectation score (scale 0-72) for African Americans was 45.4 versus 51.5 for whites (mean difference 6.1, P < 0.001). Multivariable adjustment for disease severity, socioeconomic factors, education, social support, literacy, and trust reduced these racial differences to 3.8 points (95% confidence interval [95% CI] 1.2, 6.3) among knee OA patients and 4.2 points (95% CI 0.4, 8.0) among hip patients. CONCLUSION: Among potential candidates for joint replacement, African American patients have significantly lower expectations for surgical outcomes than white patients. This difference is not entirely explained by racial differences in demographics, disease severity, education, income, social support, or trust.

Dual localization pathways for the engulfment proteins during Bacillus subtilis sporulation.

Engulfment in Bacillus subtilis is mediated by two complementary systems, SpoIID, SpoIIM and SpoIIP (DMP), which are essential for engulfment, and the SpoIIQ-SpoIIIAGH (Q-AH) zipper, which provides a secondary engulfment mechanism and recruits other proteins to the septum. We here identify two mechanisms by which DMP localizes to the septum. The first depends on SpoIIB, which is recruited to the septum during division and provides a septal landmark for efficient DMP localization. However, sporangia lacking SpoIIB ultimately localize DMP and complete engulfment, suggesting a second mechanism for DMP localization. This secondary targeting pathway depends on SpoIVFA and SpoIVFB, which are recruited to the septum by the Q-AH zipper. The absence of a detectable localization phenotype in mutants lacking only SpoIVFAB (or Q-AH) suggests that SpoIIB provides the primary DMP localization pathway while SpoIVFAB provides a secondary pathway. In keeping with this hypothesis, the spoIIB spoIVFAB mutant strain has a synergistic engulfment defect at septal thinning (which requires DMP) and is completely defective in DMP localization. Thus, the Q-AH zipper both provides a compensatory mechanism for engulfment when DMP activity is reduced, and indirectly provides a compensatory mechanism for septal localization of DMP when its primary targeting pathway is disrupted.