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Objective To present a brief historical review of treatment options for pelvic organ prolapse with a focus on anterior vaginal wall defects and highlight changing practice patterns in the era of synthetic mesh controversy. Methods A MEDLINE and PubMed search was performed using the keywords pelvic organ prolapse, anterior colporrhaphy, and cystocele followed by a manual search of bibliographies. Results Ancient treatments included Hippocratic succession, local astringent, and use of pomegranates as crude pessaries. More sophisticated surgical techniques evolved in the 19th century with further refinement in the early 20th century. Numerous native tissue apposition techniques were popularized by Kelly, Kennedy, Burch, and Raz. Due to poor durability, surgeons sought alternate approaches including biologic and synthetic grafts. Synthetic transvaginal mesh (TVM) initially included use of Tantalum and Marlex to repair anterior wall defects. Both were eventually abandoned due to complications. TVM was re-designed, re-marketed, and re-introduced. Type 1 polypropylene monofilament TVM use became ubiquitous in female pelvic surgery peaking between 2004 and 2008. Initial promising outcomes were soon eclipsed by a surge of adverse events leading to multiple FDA warnings, reclassification to Class III, high-risk medical device, and ultimately a complete recall in 2019. Conclusion The bidirectional pendulum swing on use of synthetic TVM has been occurring since its introduction 50 years ago. In the current era of mesh controversy, more practitioners are now revisiting previously described native tissue and biologic graft techniques. It appears that history has repeated itself.

Phenotypic screening is a neoclassical approach for drug discovery. We conducted phenotypic screening for insulin secretion enhancing agents using INS-1E insulinoma cells as a model system for pancreatic beta-cells. A principal regulator of insulin secretion in beta-cells is the metabolically regulated potassium channel Kir6.2/SUR1 complex. To characterize hit compounds, we developed an assay to quantify endogenous potassium channel activity in INS-1E cells. We quantified ligand-regulated potassium channel activity in INS-1E cells using fluorescence imaging and thallium flux. Potassium channel activity was metabolically regulated and coupled to insulin secretion. The pharmacology of channel opening agents (diazoxide) and closing agents (sulfonylureas) was used to validate the applicability of the assay. A precise high-throughput assay was enabled, and phenotypic screening hits were triaged to enable a higher likelihood of discovering chemical matter with novel and useful mechanisms of action.

Inflammatory breast cancer (IBC), a rare form of breast cancer associated with increased angiogenesis and metastasis, is largely driven by tumor-stromal interactions with the vasculature and the extracellular matrix (ECM). However, there is currently a lack of understanding of the role these interactions play in initiation and progression of the disease. In this study, we developed the first three-dimensional, in vitro, vascularized, microfluidic IBC platform to quantify the spatial and temporal dynamics of tumor-vasculature and tumor-ECM interactions specific to IBC. Platforms consisting of collagen type 1 ECM with an endothelialized blood vessel were cultured with IBC cells, MDA-IBC3 (HER2+) or SUM149 (triple negative), and for comparison to non-IBC cells, MDA-MB-231 (triple negative). Acellular collagen platforms with endothelialized blood vessels served as controls. SUM149 and MDA-MB-231 platforms exhibited a significantly (p < .05) higher vessel permeability and decreased endothelial coverage of the vessel lumen compared to the control. Both IBC platforms, MDA-IBC3 and SUM149, expressed higher levels of vascular endothelial growth factor (p < .05) and increased collagen ECM porosity compared to non-IBCMDA-MB-231 (p < .05) and control (p < .01) platforms. Additionally, unique to the MDA-IBC3 platform, we observed progressive sprouting of the endothelium over time resulting in viable vessels with lumen. The newly sprouted vessels encircled clusters of MDA-IBC3 cells replicating a key feature of in vivo IBC. The IBC in vitro vascularized platforms introduced in this study model well-described in vivo and clinical IBC phenotypes and provide an adaptable, high throughput tool for systematically and quantitatively investigating tumor-stromal mechanisms and dynamics of tumor progression.

Background Therapy targeted to the human epidermal growth factor receptor type 2 (HER2) is used in combination with cytotoxic therapy in treatment of HER2+ breast cancer. Trastuzumab, a monoclonal antibody that targets HER2, has been shown pre-clinically to induce vascular changes that can increase delivery of chemotherapy. To quantify the role of immune modulation in treatment-induced vascular changes, this study identifies temporal changes in myeloid cell infiltration with corresponding vascular alterations in a preclinical model of HER2+ breast cancer following trastuzumab treatment. Methods HER2+ tumor-bearing mice (N = 46) were treated with trastuzumab or saline. After extraction, half of each tumor was analyzed by immunophenotyping using flow cytometry. The other half was quantified by immunohistochemistry to characterize macrophage infiltration (F4/80), vascularity (CD31 and α-SMA), proliferation (Ki67) and cellularity (H&E). Additional mice (N = 10) were used to quantify differences in tumor cytokines between control and treated groups. Results Immunophenotyping showed an increase in macrophage infiltration 24 h after trastuzumab treatment (P ≤ 0.05). With continued trastuzumab treatment, the M1 macrophage population increased (P = 0.02). Increases in vessel maturation index (i.e., the ratio of α-SMA to CD31) positively correlated with increases in tumor infiltrating M1 macrophages (R = 0.33, P = 0.04). Decreases in VEGF-A and increases in inflammatory cytokines (TNF-α, IL-1β, CCL21, CCL7, and CXCL10) were observed with continued trastuzumab treatment (P ≤ 0.05). Conclusions Preliminary results from this study in a murine model of HER2+ breast cancer show correlations between immune modulation and vascular changes, and reveals the potential for anti-HER2 therapy to reprogram immunosuppressive components of the tumor microenvironment. The quantification of immune modulation in HER2+ breast cancer, as well as the mechanistic insight of vascular alterations after anti-HER2 treatment, represent novel contributions and warrant further assessment for potential clinical translation.

ObjectivesTo survey on the availability and use of primary care services in slum populations.DesignRetrospective, cross-sectional, household, individual and healthcare provider surveys.SettingSeven slum sites in four countries (Nigeria, Kenya, Pakistan and Bangladesh).ParticipantsResidents of slums and informal settlements.Primary and secondary outcome measuresPrimary care consultation rates by type of provider and facility.ResultsWe completed 7692 household, 7451 individual adult and 2633 individual child surveys across seven sites. The majority of consultations were to doctors/nurses (in clinics or hospitals) and pharmacies rather than single-handed providers or traditional healers. Consultation rates with a doctor or nurse varied from 0.2 to 1.5 visits per person-year, which was higher than visit rates to any other type of provider in all sites except Bangladesh, where pharmacies predominated. Approximately half the doctor/nurse visits were in hospital outpatient departments and most of the remainder were to clinics. Over 90% of visits across all sites were for acute symptoms rather than chronic disease. Median travel times were between 15 and 45 min and the median cost per visit was between 2% and 10% of a household’s monthly total expenditure. Medicines comprised most of the cost. More respondents reported proximity (54%–78%) and service quality (31%–95%) being a reason for choosing a provider than fees (23%–43%). Demand was relatively inelastic with respect to both price of consultation and travel time.ConclusionsPeople in slums tend to live sufficiently close to formal doctor/nurse facilities for their health-seeking behaviour to be influenced by preference for provider type over distance and cost. However, costs, especially for medicines are high in relation to income and use rates remain significantly below those of high-income countries.

Type 2 diabetes (T2D) is associated with defective insulin secretion and reduced β cell mass. Available treatments provide a temporary reprieve, but secondary failure rates are high, making insulin supplementation necessary. Reversibility of β cell failure is a key translational question. Here, we reverse engineered and interrogated pancreatic islet–specific regulatory networks to discover T2D-specific subpopulations characterized by metabolic inflexibility and endocrine progenitor/stem cell features. Single-cell gain- and loss-of-function and glucose-induced Ca(2+) flux analyses of top candidate master regulatory (MR) proteins in islet cells validated transcription factor BACH2 and associated epigenetic effectors as key drivers of T2D cell states. BACH2 knockout in T2D islets reversed cellular features of the disease, restoring a nondiabetic phenotype. BACH2-immunoreactive islet cells increased approximately 4-fold in diabetic patients, confirming the algorithmic prediction of clinically relevant subpopulations. Treatment with a BACH inhibitor lowered glycemia and increased plasma insulin levels in diabetic mice, and restored insulin secretion in diabetic mice and human islets. The findings suggest that T2D-specific populations of failing β cells can be reversed and indicate pathways for pharmacological intervention, including via BACH2 inhibition.

Due to the continued spread of COVID-19 and the emergence of novel mutated viral variants, families all over the world are experiencing wide-ranging stressors that threaten not only their financial well-being but also their physical and mental health. The present study assessed the association between excessive electronic media exposure of pandemic-related news and mental health of the residents of Ha'il Province, Saudi Arabia. The present study also assessed the prevalence of perceived stress, fear of COVID-19, anxiety, depression, and loneliness due to COVID-19-related restrictions in the same population.A total of 490 residents of Ha'il Province participated in a cross-sectional online survey during a two-month period (March to April 2021). A validated 38-item self-report survey was used to collect the data.Significant associations were reported between excessive electronic media exposure and the prevalence of perceived stress (χ2=140.56; p.001), generalized anxiety (χ2=74.55; p.001), depression (χ2=71.58; p.001), COVID-19-related fear (χ2=24.54; p.001), and loneliness (χ2=11.46; p.001). It was also found that participants without depressive symptoms were 0.28 times less likely to have been exposed to excessive electronic media exposure (AOR: 0.28; C.I. 0.16-0.48; p.001). Similarly, participants with no stress/mild stress were 0.32 times less likely to have been exposed to excessive electronic media exposure (AOR: 0.32; C.I. 0.19-0.52; p.001).The findings of the present study suggest an urgent need for educational resilience programs (online and in-person) for susceptible individuals (females, unemployed, urban residents, etc.). Such programs would help them to develop skills to cope with the psychological impact of the COVID-19 pandemic.

Objective GPR142 agonists are being pursued as novel diabetes therapies by virtue of their insulin secretagogue effects. But it is undetermined whether GPR142's functions in pancreatic islets are limited to regulating insulin secretion. The current study expands research on its action. Methods and Results We demonstrated by in situ hybridization and immunostaining that GPR142 is expressed not only in β cells but also in a subset of α cells. Stimulation of GPR142 by a selective agonist increased glucagon secretion in both human and mouse islets. More importantly, the GPR142 agonist also potentiated glucagon-like peptide-1 (GLP-1) production and its release from islets through a mechanism that involves upregulation of prohormone convertase 1/3 expression. Strikingly, stimulation of insulin secretion and increase in insulin content via GPR142 engagement requires intact GLP-1 receptor signaling. Furthermore, GPR142 agonist increased β cell proliferation and protected both mouse and human islets against stress-induced apoptosis. Conclusions Collectively, we provide here evidence that local GLP-1 release from α cells defines GPR142's beneficial effects on improving β cell function and mass, and we propose that GPR142 agonism may have translatable and durable efficacy for the treatment of type 2 diabetes., Graphical abstract, Highlights • GPR142 is expressed in both α cells and β cells in pancreatic islets. • Stimulation of GPR142 by a selective agonist increases glucagon secretion. • GPR142 agonism promotes glucagon-like peptide-1 release from islets by upregulating prohormone convertase 1/3. • Increases in insulin secretion and content via GPR142 engagement require intact GLP-1 receptor signaling.

Incretin and insulin responses to nutrient loads are suppressed in persons with diabetes, resulting in decreased glycemic control. Agents including sulfonylureas and dipeptidyl peptidase-4 inhibitors (DPP4i) partially reverse these effects and provide therapeutic benefit; however, their modes of action limit efficacy. Because somatostatin (SST) has been shown to suppress insulin and glucagonlike peptide-1 (GLP-1) secretion through the Gi-coupled SST receptor 5 (SSTR5) isoform in vitro, antagonism of SSTR5 may improve glycemic control via intervention in both pathways. Here, we show that a potent and selective SSTR5 antagonist reverses the blunting effects of SST on insulin secretion from isolated human islets, and demonstrate that SSTR5 antagonism affords increased levels of systemic GLP-1 in vivo. Knocking out Sstr5 in mice provided a similar increase in systemic GLP-1 levels, which were not increased further by treatment with the antagonist. Treatment of mice with the SSTR5 antagonist in combination with a DPP4i resulted in increases in systemic GLP-1 levels that were more than additive and resulted in greater glycemic control compared with either agent alone. In isolated human islets, the SSTR5 antagonist completely reversed the inhibitory effect of exogenous SST-14 on insulin secretion. Taken together, these data suggest that SSTR5 antagonism should increase circulating GLP-1 levels and stimulate insulin secretion (directly and via GLP-1) in humans, improving glycemic control in patients with diabetes.

Many biological cells/tissues sense the mechanical properties of their local environments via mechanoreceptors, proteins that can respond to forces like pressure or mechanical perturbations. Mechanoreceptors detect their stimuli and transmit signals via a great diversity of mechanisms. Some of the most common roles for mechanoreceptors are in neuronal responses, like touch and pain, or hair cells which function in balance and hearing. Mechanosensation is also important for cell types which are regularly exposed to shear stress such as endothelial cells, which line blood vessels, or blood cells which experience shear in normal circulation. Viscometers are devices that detect the viscosity of fluids. Rotational viscometers may also be used to apply a known shear force to fluids. The ability of these instruments to introduce uniform shear to fluids has been exploited to study many biological fluids including blood and plasma. Viscometry may also be used to apply shear to the cells in a solution, and to test the effects of shear on specific ligand-receptor pairs. Here, we utilize cone-plate viscometry to test the effects of endogenous levels of shear stress on platelets treated with antibodies against the platelet mechanosensory receptor complex GPIb-IX.

In nanoscale communication, diffusion-based molecular communication (DBMC) in which information is encoded into molecule patterns by a transmitter nanomachine, has emerged as a promising communication system, particularly for biomedical and healthcare applications. Although, numerous studies have been conducted to evaluate and analyze DBMC systems, investigation on DBMC system through a multilayer channel has received less attention. The aims of this paper are to formulate channel characteristics and to evaluate the performance of multilayer DBMC channel in terms of delay spread and capacity. In this paper, the propagation of molecules over an $n-$ layer channel is assumed to follow the Brownian motion and subjected to Fick’s law of diffusion. Fourier transform is used to convert time to frequency domain functions. Besides, the multilayer channel is considered as a linear and deterministic channel. For the performance evaluation, the air-water-blood plasma medium representing the simplified multilayer diffusion model in the respiratory system was chosen. It was found that a high channel capacity can be achieved with wide transmission bandwidth, short transmission distance, and high averaged transmitted power. In addition, the findings showed that channel delay spread increases as both the transmission distance, and the pulse duration increased. By setting the symbol duration greater than the pulse duration or delay spread, an inter-symbol interference problem due to previous molecules transmission can be mitigated. These findings can be used as a guide in the development and fabrication of future artificial nanocommunication and nanonetworks systems involving multilayer transmission medium.

UNLABELLED ESSENTIALS: Many anti-glycoprotein (GP)Ibα antibodies induce platelet clearance in a dimer-dependent manner. Characterization of monoclonal antibodies that bind the mechanosensitive domain (MSD) of GPIbα. An anti-MSD antibody binds two copies of GPIbα in platelets but does not induce platelet clearance. The prevailing clustering model of GPIbα signaling is incorrect or needs revision. BACKGROUND The mechanism of platelet clearance is not clear. Many antibodies binding the membrane-distal ligand-binding domain of glycoprotein (GP)Ibα induce rapid clearance of platelets and acute thrombocytopenia, which requires the bifurcated antibody structure. It was thought that binding of these antibodies induced lateral dimerization or clustering of GPIbα in the plasma membrane, which leads to downstream signaling and platelet clearance. However, many antibodies targeting GPIbβ and GPIX, which are associated with GPIbα in the GPIb-IX complex, do not induce platelet clearance, which is in contradiction to the clustering model. OBJECTIVES To test whether dimerization or clustering of GPIbα is sufficient to transmit the signal that leads to platelet clearance. METHODS We have recently raised several mAbs targeting the mechanosensitive domain (MSD) of GPIbα. Binding of these anti-MSD antibodies was characterized with biochemical methods. Their ability to stimulate platelets and induce platelet clearance in mice was assessed. RESULTS AND CONCLUSION Infusion of anti-MSD antibodies does not cause thrombocytopenia in mice. These antibodies show no detectable effects on platelet activation and aggregation in vitro. Further biochemical investigation showed that the anti-MSD antibody 3D1 binds two copies of GPIbα on the platelet surface. Therefore, lateral dimerization of GPIbα induced by antibody binding is not sufficient to initiate GPIb-IX signaling and induce platelet clearance. Our results suggest that a factor other than or in addition to clustering of GPIbα is required to induce platelet clearance.

Estrogen hormones play an important role in controlling glucose homeostasis and pancreatic β-cell function. Despite the significance of estrogen hormones for regulation of glucose metabolism, little is known about the roles of endogenous estrogen metabolites in modulating pancreatic β-cell function. In this study, we evaluated the effects of major natural estrogen metabolites, catechol estrogens, on insulin secretion in pancreatic β-cells. We show that catechol estrogens, hydroxylated at positions C2 and C4 of the steroid A ring, rapidly potentiated glucose-induced insulin secretion via a nongenomic mechanism. 2-Hydroxyestrone, the most abundant endogenous estrogen metabolite, was more efficacious in stimulating insulin secretion than any other tested catechol estrogens. In insulin-secreting cells, catechol estrogens produced rapid activation of calcium influx and elevation in cytosolic free calcium. Catechol estrogens also generated sustained elevations in cytosolic free calcium and evoked inward ion current in HEK293 cells expressing the transient receptor potential A1 (TRPA1) cation channel. Calcium influx and insulin secretion stimulated by estrogen metabolites were dependent on the TRPA1 activity and inhibited with the channel-specific pharmacological antagonists or the siRNA. Our results suggest the role of estrogen metabolism in a direct regulation of TRPA1 activity with potential implications for metabolic diseases.

The purpose of this study is to investigate imaging and histology-based measurements of intratumoral heterogeneity to evaluate early treatment response to targeted therapy in a murine model of HER2+ breast cancer. BT474 tumor-bearing mice (N = 30) were treated with trastuzumab or saline and imaged longitudinally with either dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) or 18F-fluoromisonidazole (FMISO) positron emission tomography (PET). At the imaging study end point (day 4 for MRI or 7 for PET), each tumor was excised for immunohistochemistry analysis. Voxel-based histogram analysis was performed on imaging-derived parametric maps (i.e., Ktrans and ve from DCE-MRI, SUV from 18F-FMISO-PET) of the tumor region of interest to measure heterogeneity. Image processing and histogram analysis of whole tumor slice immunohistochemistry data were performed to validate the in vivo imaging findings. Trastuzumab-treated tumors had increased heterogeneity in quantitative imaging measures of cellularity (ve), with a mean Kolmogorov-Smirnov (K-S) distance of 0.32 (P = .05) between baseline and end point distributions. Trastuzumab-treated tumors had increased vascular heterogeneity (Ktrans) and decreased hypoxic heterogeneity (SUV), with a mean K-S distance of 0.42 (P < .01) and 0.46 (P = .047), respectively, between baseline and study end points. These observations were validated by whole-slice immunohistochemistry analysis with mean interquartile range of CD31 distributions of 1.72 for treated and 0.95 for control groups (P = .02). Quantitative longitudinal changes in tumor cellular and vascular heterogeneity in response to therapy may provide evidence for early prediction of response and guide therapy for patients with HER2+ breast cancer.

Objective To discuss standard-of-care and emerging imaging techniques employed for screening and detection, diagnosis and staging, monitoring response to therapy, and guiding cancer treatments. Data Sources Published journal articles indexed in the National Library of Medicine database and relevant websites. Conclusion Imaging plays a fundamental role in the care of cancer patients and specifically, breast cancer patients in the neoadjuvant setting, providing an excellent opportunity for interprofessional collaboration between oncologists, researchers, radiologists, and oncology nurses. Quantitative imaging strategies to assess cellular, molecular, and vascular characteristics within the tumor is needed to better evaluate initial diagnosis and treatment response. Implications for Nursing Practice Nurses caring for patients in all settings must continue to seek education on emerging imaging techniques. Oncology nurses provide education about the test, ensure the patient has appropriate pre-testing instructions, and manage patient expectations about timing of results availability.

Conventional methods for histopathologic tissue diagnosis are labor- and time-intensive and can delay decision-making during diagnostic and therapeutic procedures. We report the development of an automated and biocompatible handheld mass spectrometry device for rapid and nondestructive diagnosis of human cancer tissues. The device, named MasSpec Pen, enables controlled and automated delivery of a discrete water droplet to a tissue surface for efficient extraction of biomolecules. We used the MasSpec Pen for ex vivo molecular analysis of 20 human cancer thin tissue sections and 253 human patient tissue samples including normal and cancerous tissues from breast, lung, thyroid, and ovary. The mass spectra obtained presented rich molecular profiles characterized by a variety of potential cancer biomarkers identified as metabolites, lipids, and proteins. Statistical classifiers built from the histologically validated molecular database allowed cancer prediction with high sensitivity (96.4%), specificity (96.2%), and overall accuracy (96.3%), as well as prediction of benign and malignant thyroid tumors and different histologic subtypes of lung cancer. Notably, our classifier allowed accurate diagnosis of cancer in marginal tumor regions presenting mixed histologic composition. Last, we demonstrate that the MasSpec Pen is suited for in vivo cancer diagnosis during surgery performed in tumor-bearing mouse models, without causing any observable tissue harm or stress to the animal. Our results provide evidence that the MasSpec Pen could potentially be used as a clinical and intraoperative technology for ex vivo and in vivo cancer diagnosis.

Summary Objective We investigated whether pain at rest and pain on activity were differentially associated with neuropathic pain scores in individuals with end-stage hip and knee OA. Design Study participants were 843 patients with hip or knee OA scheduled for total joint arthroplasty. In pre-surgery questionnaires, measures of socio-demographics, health status, medication use, neuropathic pain (painDETECT), pain at rest and pain on activity (WOMAC pain items), depression (HADS) and pain catastrophizing (PCS) were collected. Multivariable linear regression models were estimated for men and women separately to examine the association between neuropathic pain scores (outcome) and study measures, entered in blocks. Results Sample mean age was 65.1 years (SD: 9.6); 57.1% were women. Mean painDETECT scores were significantly higher ( P ≤ 0.001) for women (11.2 ± 6.6 out of 38) than men (9.3 ± 7.0), with 35.6% of women and 27.7% of men meeting cut-offs for possible or likely neuropathic pain. In the final regression model for women, the coefficients for both types of pain were statistically significant, although the coefficient for pain at rest was 1.6 times greater than that for pain on activity. For men, only pain at rest was significantly associated with neuropathic pain scores. Conclusions Findings support that possible neuropathic pain is experienced by a notable proportion of patients with end-stage hip and knee OA and is more strongly associated with pain at rest than pain on activity, particularly in men. Clinical presentation of pain at rest may warrant more thorough evaluation for potential neuropathic pain and have implications for appropriate pain management.

Immune thrombocytopenia (ITP) is a prevalent autoimmune disease characterized by autoantibody-induced platelet clearance. Some ITP patients are refractory to standard immunosuppressive treatments such as intravenous immunoglobulin (IVIg). These patients often have autoantibodies that target the ligand-binding domain (LBD) of glycoprotein Ibα (GPIbα), a major subunit of the platelet mechanoreceptor complex GPIb-IX. However, the molecular mechanism of this Fc-independent platelet clearance is not clear. Here, we report that many anti-LBD monoclonal antibodies such as 6B4, but not AK2, activated GPIb-IX in a shear-dependent manner and induced IVIg-resistant platelet clearance in mice. Single-molecule optical tweezer measurements of antibodies pulling on full-length GPIb-IX demonstrated that the unbinding force needed to dissociate 6B4 from the LBD far exceeds the force required to unfold the juxtamembrane mechanosensory domain (MSD) in GPIbα, unlike the AK2-LBD unbinding force. Binding of 6B4, not AK2, induced shear-dependent unfolding of the MSD on the platelet, as evidenced by increased exposure of a linear sequence therein. Imaging flow cytometry and aggregometry measurements of platelets and LBD-coated platelet-mimetic beads revealed that 6B4 can sustain crosslinking of platelets under shear, whereas 6B4 Fab and AK2 cannot. These results suggest a novel mechanism by which anti-LBD antibodies can exert a pulling force on GPIb-IX via platelet crosslinking, activating GPIb-IX by unfolding its MSD and inducing Fc-independent platelet clearance.

Essentials The mechanism for the auto-inhibition of von Willebrand factor (VWF) remains unclear. Hydrogen exchange of two VWF A1 fragments with disparate activities was measured and compared. Discontinuous residues flanking A1 form a structural module that blocks A1 binding to the platelet. Our results suggest a potentially unified model of VWF activation. Click to hear an ISTH Academy presentation on the domain architecture of VWF and activation by elongational flow by Dr Springer SUMMARY: Background How von Willebrand factor (VWF) senses and responds to shear flow remains unclear. In the absence of shear flow, VWF or its fragments can be induced to bind spontaneously to platelet GPIbα. Objectives To elucidate the auto-inhibition mechanism of VWF. Methods Hydrogen-deuterium exchange (HDX) of two recombinant VWF fragments expressed from baby hamster kidney cells were measured and compared. Results The shortA1 protein contains VWF residues 1261-1472 and binds GPIbα with a significantly higher affinity than the longA1 protein that contains VWF residues 1238-1472. Both proteins contain the VWF A1 domain (residues 1272-1458). Many residues in longA1, particularly those in the N- and C-terminal sequences flanking the A1 domain, and in helix α1, loops α1β2 and β3α2, demonstrated markedly reduced HDX compared with their counterparts in shortA1. The HDX-protected region in longA1 overlaps with the GPIbα-binding interface and is clustered with type 2B von Willebrand disease (VWD) mutations. Additional comparison with the HDX of denatured longA1 and ristocetin-bound longA1 indicates the N- and C-terminal sequences flanking the A1 domain form cooperatively an integrated autoinhibitory module (AIM) that interacts with the HDX-protected region. Binding of ristocetin to the C-terminal part of the AIM desorbs the AIM from A1 and enables longA1 binding to GPIbα. Conclusion The discontinuous AIM binds the A1 domain and prevents it from binding to GPIbα, which has significant implications for the pathogenesis of type 2B VWD and the shear-induced activation of VWF activity.

We asked if the use of antibiotic-laden bone cement (ALBC) decreased the deep infection rate after primary total knee arthroplasty as compared to plain bone cement. We surveyed 1625 consecutive patients for relevant covariates. Joint pain and function were assessed at baseline and at 1 year of follow-up with the Western Ontario McMaster University Osteoarthritis Index scores. The incidence of deep infection at 1-year follow-up was recorded. There were no differences in baseline covariates between groups (P > .05). We found a deep infection rate of 2.2% in the ALBC group and 3.1% in the plain bone cement group (P = .27). Adjusted analysis showed that ALBC was not predictive of a lower infection rate at 1 year (P = .84). Antibiotic-laden bone cement did not reduce the incidence of deep infection following primary total knee arthroplasty at 1-year follow-up.

Administration of activated protein C (APC) protects from renal dysfunction, but the underlying mechanism is unknown. APC exerts both antithrombotic and cytoprotective properties, the latter via modulation of protease-activated receptor-1 (PAR-1) signaling. We generated APC variants to study the relative importance of the two functions of APC in a model of LPS-induced renal microvascular dysfunction. Compared with wild-type APC, the K193E variant exhibited impaired anticoagulant activity but retained the ability to mediate PAR-1-dependent signaling. In contrast, the L8W variant retained anticoagulant activity but lost its ability to modulate PAR-1. By administering wild-type APC or these mutants in a rat model of LPS-induced injury, we found that the PAR-1 agonism, but not the anticoagulant function of APC, reversed LPS-induced systemic hypotension. In contrast, both functions of APC played a role in reversing LPS-induced decreases in renal blood flow and volume, although the effects on PAR-1-dependent signaling were more potent. Regarding potential mechanisms for these findings, APC-mediated PAR-1 agonism suppressed LPS-induced increases in the vasoactive peptide adrenomedullin and infiltration of iNOS-positive leukocytes into renal tissue. However, the anticoagulant function of APC was responsible for suppressing LPS-induced stimulation of the proinflammatory mediators ACE-1, IL-6, and IL-18, perhaps accounting for its ability to modulate renal hemodynamics. Both variants reduced active caspase-3 and abrogated LPS-induced renal dysfunction and pathology. We conclude that although PAR-1 agonism is solely responsible for APC-mediated improvement in systemic hemodynamics, both functions of APC play distinct roles in attenuating the response to injury in the kidney.

Recently, the use of metal-on-metal articulations in total hip arthroplasty (THA) has led to an increase in adverse events owing to local soft-tissue reactions from metal ions and wear debris. While the majority of these implants perform well, it has been increasingly recognised that a small proportion of patients may develop complications secondary to systemic cobalt toxicity when these implants fail. However, distinguishing true toxicity from benign elevations in cobalt ion levels can be challenging.The purpose of this two part series is to review the use of cobalt alloys in THA and to highlight the following related topics of interest: mechanisms of cobalt ion release and their measurement, definitions of pathological cobalt ion levels, and the pathophysiology, risk factors and treatment of cobalt toxicity. Historically, these metal-on-metal arthroplasties are composed of a chromium-cobalt articulation.The release of cobalt is due to the mechanical and oxidative stresses placed on the prosthetic joint. It exerts its pathological effects through direct cellular toxicity.This manuscript will highlight the pathophysiology of cobalt toxicity in patients with metal-on-metal hip arthroplasties.Take home message: Patients with new or evolving hip symptoms with a prior history of THA warrant orthopaedic surgical evaluation. Increased awareness of the range of systemic symptoms associated with cobalt toxicity, coupled with prompt orthopaedic intervention, may forestall the development of further complications.Cite this article: Bone Joint J 2016;98-B:6–13.

As adverse events related to metal on metal hip arthroplasty have been better understood, there has been increased interest in toxicity related to the high circulating levels of cobalt ions. However, distinguishing true toxicity from benign elevations in cobalt levels can be challenging. The purpose of this review is to examine the use of cobalt alloys in total hip arthroplasty, to review the methods of measuring circulating cobalt levels, to define a level of cobalt which is considered pathological and to review the pathophysiology, risk factors and treatment of cobalt toxicity. To the best of our knowledge, there are 18 published cases where cobalt metal ion toxicity has been attributed to the use of cobalt-chromium alloys in hip arthroplasty. Of these cases, the great majority reported systemic toxic reactions at serum cobalt levels more than 100 μg/L. This review highlights some of the clinical features of cobalt toxicity, with the goal that early awareness may decrease the risk factors for the development of cobalt toxicity and/or reduce its severity. Take home message: Severe adverse events can arise from the release of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic surgeons should not only be aware of the presenting problems, but also have the knowledge to treat appropriately. Cite this article: Bone Joint J 2016;98-B:14–20.

Activated protein C (APC) is an important modulator of vascular function that has antithrombotic and anti-inflammatory properties. Studies in humans have shown modulation of endotoxin-induced hypotension by recombinant human APC, drotrecogin alfa (activated), however, the mechanism for this effect is unclear. We have found that APC suppresses the induction of the potent vasoactive peptide adrenomedullin (ADM) and could downregulate lipopolysaccharide (LPS)-induced ADM messenger RNA (mRNA) and nitrite levels in cell culture. This effect was dependent on signaling through protease-activated receptor 1. Addition of 1400W, an irreversible inducible nitric oxide synthase (iNOS) inhibitor, inhibited LPS-induced ADM mRNA, suggesting that ADM induction is NO mediated. Furthermore, in a rat model of endotoxemia, APC (100 microg/kg, i.v.) prevented LPS (10 mg/kg, i.v.)-induced hypotension, and suppressed ADM mRNA and protein expression. APC also inhibited iNOS mRNA and protein levels along with reduction in NO by-products (NOx). We also observed a significant reduction in iNOS-positive leukocytes adhering to vascular endothelium after APC treatment. Moreover, we found that APC inhibited the expression of interferon-gamma (IFN-gamma), a potent activator of iNOS. In a human study of LPS-induced hypotension, APC reduced the upregulation of plasma ADM levels, coincident with protection against the hypotensive response. Overall, we demonstrate that APC blocks the induction of ADM, likely mediated by IFN-gamma and iNOS, and suggests a mechanism that may account for ameliorating LPS-induced hypotension. Furthermore, our data provide a new understanding for the role of APC in modulating vascular response to insult.

Background: Improving health-related quality of life (HRQoL) necessitates an understanding of the influence of patient characteristics on, and interrelationship among, HRQoL domains. In osteoarthritis (OA), these associations have predominantly been examined in hip/knee populations. We investigated whether there were differences in these associations between foot/ankle and knee OA samples. Methods: Individuals seeking orthopedic care for foot/ankle or knee OA completed a questionnaire pre-consultation, including HRQoL domains (bodily pain [BP], physical [PF] and social functioning [SF], and mental [MH] and general health [GH]), obesity, comorbidity, and sociodemographic characteristics. Associations were examined via stratified path analysis (foot/ankle vs knee). Foot/ankle: n = 180, mean age = 55 (range: 25 to 82), 52% female. Knee: n = 253, mean age = 62 (range: 26 to 92), 51% female. Results: The interrelationship among HRQoL domains was generally similar between groups. However, the influence of patient characteristics differed. Low educational status was associated with worse scores for GH, MH, and SF in the foot/ankle group, whereas no significant effects were found in the knee group. Obesity was associated with worse scores for SF, BP, and GH in the foot/ankle compared to the knee group. Patient characteristics explained considerably more of the variation in domain scores in the foot/ankle group. Conclusion: There are significant differences in the impact of patient characteristics on HRQoL domains in foot/ankle versus knee OA patients. Therefore, a universal approach to patient education/intervention to improve HRQoL in lower-extremity OA is not likely to achieve optimal results. Based on these findings, we recommend joint-specific patient education, with a particular emphasis on patient characteristics among the foot/ankle OA population. Level of Evidence: Level III, retrospective comparative study.

Staphylococcus aureus virulence is coordinated through the Agr quorum-sensing system to produce an array of secreted molecules. One important class of secreted virulence factors is the phenol-soluble modulins (PSMs). PSMs are small-peptide toxins that have recently been characterized for their roles in infection, biofilm development, and subversion of the host immune system. In this work, we demonstrate that the signal peptide of the S. aureus quorum-sensing signal, AgrD, shares structural and functional similarities with the PSM family of toxins. The efficacy of this peptide (termed N-AgrD) beyond AgrD propeptide trafficking has never been described before. We observe that N-AgrD, like the PSMs, is found in the amyloid fibrils of S. aureus biofilms and is capable of forming and seeding amyloid fibrils in vitro . N-AgrD displays cytolytic and proinflammatory properties that are abrogated after fibril formation. These data suggest that the N-AgrD leader peptide affects S. aureus biology in a manner similar to that described previously for the PSM peptide toxins. Taken together, our findings suggest that peptide cleavage products can affect cellular function beyond their canonical roles and may represent a class of virulence factors warranting further exploration.

The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization., IMPORTANCE Triclosan has been used as a biocide for over 40 years, but the broader effects that it has on the human microbiome have not been investigated. We demonstrate that triclosan is present in nasal secretions of a large portion of a test population and its presence correlates with Staphylococcus aureus nasal colonization. Triclosan also promotes the binding of S. aureus to human proteins and increases the susceptibility of rats to nasal colonization by S. aureus. These findings are significant because S. aureus colonization is a known risk factor for the development of several types of infections. Our data demonstrate the unintended consequences of unregulated triclosan use and contribute to the growing body of research demonstrating inadvertent effects of triclosan on the environment and human health.

The mechanism of action of 2-chlorpromazine (2-chloro-10-(3-dimethylaminopropyl)-phenothiazine) as a reversal agent for P-glycoprotein-mediated multidrug resistance was investigated using inside out-orientated membrane vesicles prepared from vinblastine-resistant human CCRF-CEM leukaemia cells (VBL1000). 2-Chlorpromazine (10 microM) completely inhibited ATP-dependent P-glycoprotein-mediated vinblastine accumulation in the vesicles. Whereas in the absence of added ligands VBL transport was described by a hyperbolic function of vinblastine concentration, in the presence of 2-chlorpromazine vinblastine transport was a sigmoidal function. 2-Chlorpromazine was shown previously [Syed SK, Christopherson RI and Roufogalis BD (1996) Biochem Mol Biol Int 39: 687-696] to be actively transported into vesicles from multidrug-resistant cells. Colchicine (10 microM) and phenoxybenzamine (10 microM) blocked vinblastine transport but had no effect on 2-chlorpromazine transport into vesicles. The results were consistent with a two-state concerted model in which P-glycoprotein exists in two conformational states, P(A) and P(B), where 2-chlorpromazine is transported by the conformer, P(A), and vinblastine by the conformer, P(B). In the presence of 2-chlorpromazine, the conformer P(A) predominates and vinblastine transport is inhibited. Addition of 2-chlorpromazine during the steady state of vinblastine accumulation blocked uptake and resulted in enhanced vinblastine efflux from the vesicles. The findings were similar when vinblastine was added at the steady state of 2-chlorpromazine transport. We propose a minimal kinetic model whereby in these preloaded vesicles the complex VV.P(A).CC is formed, where two internal binding sites of P-glycoprotein (P(A)) are occupied by vinblastine (V) and the two external sites are occupied by 2-chlorpromazine (C). When the two binding sites on both the inside and outside of P-glycoprotein are saturated with ligands vinblastine is effluxed at a very rapid rate, and vice versa when vesicles are preloaded with 2-chlorpromazine and vinblastine is added outside. These unexpected observations and the concerted model developed provide an alternative mechanism of action for reversal agents that sensitize multidrug-resistant cancer cells to anti-cancer drugs.

Extracellular ATP released from pancreatic β-cells acts as a potent insulinotropic agent through activation of P2 purinergic receptors. Ectonucleotidases, a family of membrane-bound nucleotide-metabolizing enzymes, regulate extracellular ATP levels by degrading ATP and related nucleotides. Ectonucleotidase activity affects the relative proportion of ATP and its metabolites, which in turn will impact the level of purinergic receptor stimulation exerted by extracellular ATP. Therefore, we investigated the expression and role of ectonucleotidases in pancreatic β-cells. Of the ectonucleotidases studied, only ENTPD3 (gene encoding the NTPDase3 enzyme) mRNA was detected at fairly abundant levels in human and mouse pancreatic islets as well as in insulin-secreting MIN6 cells. ARL67156, a selective ectonucleotidase inhibitor, blocked degradation of extracellular ATP that was added to MIN6 cells. The compound also decreased degradation of endogenous ATP released from cells. Measurements of insulin secretion in MIN6 cells as well as in mouse and human pancreatic islets demonstrated that ARL67156 potentiated glucose-dependent insulin secretion. Downregulation of NTPDase3 expression in MIN6 cells with the specific siRNA replicated the effects of ARL67156 on extracellular ATP hydrolysis and insulin secretion. Our results demonstrate that NTPDase3 is the major ectonucleotidase in pancreatic β-cells in multiple species and that it modulates insulin secretion by controlling activation of purinergic receptors.

This is our initial report on the first 4 cases of infra-renal abdominal aortic aneurysms undergoing Endovascular Aneurysm Repair (EVAR) with local anaesthesia, controlled sedation and monitoring by an anaesthetist. All 4 patients were males with a mean age of 66.7 years. Only one (1) required ICU stay of 2 days for cardiac monitoring due to bradycardia and transient hypotension post procedure. No mortality or major post operative morbidity was recorded and the mean hospital stay post procedure was 3.5 days (range 2-5 days).

The mechanism by which chlorpromazine (2-chloro-10-(3-dimethylaminopropyl)-phenothiazine) reverses P-glycoprotein (P-gp2) mediated multidrug resistance was investigated using membrane vesicles prepared from human CCRF-CEM leukaemia cells. Chlorpromazine was transported in an ATP-dependent manner into membrane vesicles prepared from vinblastine resistant (VBL1000) cells but not from drug-sensitive cells. The chlorpromazine uptake was sensitive to osmotic pressure, indicating true transport into the vesicle lumen. The ATP-dependent chlorpromazine uptake was inhibited about 30% by the addition of ammonium chloride, indicating that a pH or electrical gradient could not account for the majority of ATP-dependent chlorpromazine uptake. The results of this study show that chlorpromazine is actively transported my P-glycoprotein and that chemosensitization by phenothiazines may occur by competition of these agents for active transport of anticancer agents by P-glycoprotein.

Symptomatic cobalt toxicity from a failed total hip replacement is a rare but devastating complication. It has been reported following revision of fractured ceramic components, as well as in patients with failed metal-on-metal articulations. Potential clinical findings include fatigue, weakness, hypothyroidism, cardiomyopathy, polycythaemia, visual and hearing impairment, cognitive dysfunction, and neuropathy. We report a case of an otherwise healthy 46-year-old patient, who developed progressively worsening symptoms of cobalt toxicity beginning approximately six months following synovectomy and revision of a fractured ceramic-on-ceramic total hip replacement to a metal-on-polyethylene bearing. The whole blood cobalt levels peaked at 6521 µg/l. The patient died from cobalt-induced cardiomyopathy. Implant retrieval analysis confirmed a loss of 28.3 g mass of the cobalt–chromium femoral head as a result of severe abrasive wear by ceramic particles embedded in the revision polyethylene liner. Autopsy findings were consistent with heavy metal-induced cardiomyopathy. We recommend using new ceramics at revision to minimise the risk of wear-related cobalt toxicity following breakage of ceramic components. Cite this article: Bone Joint J 2013;95-B:31–7.

The GPR119 receptor plays an important role in the secretion of incretin hormones in response to nutrient consumption. We have studied the ability of an array of naturally occurring endocannabinoid-like lipids to activate GPR119 and have identified several lipid receptor agonists. The most potent receptor agonists identified were three N-acylethanolamines: oleoylethanolamine (OEA), palmitoleoylethanolamine, and linoleylethanolamine (LEA), all of which displayed similar potency in activating GPR119. Another lipid, 2-oleoylglycerol (2-OG), also activated GPR119 receptor but with significantly lower potency. Endogenous levels of endocannabinoid-like lipids were measured in intestine in fasted and refed mice. Of the lipid GPR119 agonists studied, the intestinal levels of only OEA, LEA, and 2-OG increased significantly upon refeeding. Intestinal levels of OEA and LEA in the fasted mice were low. In the fed state, OEA levels only moderately increased, whereas LEA levels rose drastically. 2-OG was the most abundant of the three GPR119 agonists in intestine, and its levels were radically elevated in fed mice. Our data suggest that, in lean mice, 2-OG and LEA may serve as physiologically relevant endogenous GPR119 agonists that mediate receptor activation upon nutrient uptake.

This study was conducted to evaluate the accuracy of magnetic resonance imaging (MRI) in diagnosing meniscal tears in patients with anterior cruciate ligament (ACL) tears and to determine the frequency of missed meniscal tears on MRI. This prospective comparative study was conducted from 2009 to 2012. Patients with ACL injuries who underwent knee arthroscopy and MRI were included in the study. Two radiologists who were blinded to the clinical history and arthroscopic findings reviewed the pre-arthroscopic MR images. The presence and type of meniscal tears on MRI and arthroscopy were recorded. Arthroscopic findings were used as the reference standard. The accuracy, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of MRI in the evaluation of meniscal tears were calculated. A total of 65 patients (66 knees) were included. The sensitivity, specificity, accuracy, PPV, and NPV for the MRI diagnosis of lateral meniscal tears in our patients were 83, 97, 92, 96, and 90 %, respectively, whereas those for medial meniscus tears were 82, 92, 88, 82, and 88 %, respectively. There were five false-negative diagnoses of medial meniscus tears and four false-negative diagnoses of lateral meniscus tears. The majority of missed meniscus tears on MRI affected the peripheral posterior horns. The sensitivity for diagnosing a meniscal tear was significantly higher when the tear involved more than one-third of the meniscus or the anterior horn. The sensitivity was significantly lower for tears located in the posterior horn and for vertically oriented tears. Therefore, special attention should be given to the peripheral posterior horns of the meniscus, which are common sites of injury that could be easily missed on MRI. The high NPVs obtained in this study suggest that MRI is a valuable tool prior to arthroscopy. IV.

In this study the ability of five novel anti-oestrogens [4-iodotamoxifen, pyrrolidino-4-iodotamoxifen, ethyl bromide tamoxifen (EBTx), ICI 164,384 (ICI 164) and ICI 182,780] to alter drug toxicity to multidrug resistant cell lines have been compared. The effect of these compounds on ATP-dependent vinblastine (VBL) transport was also tested using inside-out vesicles (IOV) prepared from highly P-glycoprotein (Pgp)-expressing CCRF-CEM/VBL1000 cells. The pure anti-oestrogen ICI 164 was most effective, enhancing doxorubicin and VBL toxicity to MCF-7Adr cells 25- and 35-fold, respectively, and was also the best inhibitor of ATP-dependent [3H]VBL accumulation by IOV. Pure anti-oestrogens, tamoxifen and iodotamoxifens completely reversed VBL resistance in the mdr1 transfected lung cancer cell line, S1 1.1 , where resistance relative to wild-type cells was mediated solely by Pgp. The membrane impermeant tamoxifen derivative EBTx did not modify drug resistance, yet was as effective an inhibitor of VBL accumulation by inside-out Pgp-positive vesicles as tamoxifen. This indicates an intracellular role for tamoxifen and its derivatives in the modulation of Pgp-mediated drug resistance.

Objective.To examine differences in genes involved in fat metabolism, energy homeostasis, adipogenesis, and inflammation between endstage and early-stage knee osteoarthritis (OA) infrapatellar fat pads (IFP).Methods.Twenty-nine endstage and 5 early-stage primary OA IFP were harvested at knee surgery. Total RNA was extracted, labeled, and hybridized to whole-genome expression arrays. Unsupervised analysis of all samples using principal components analysis or 2-way hierarchical clustering showed groupings based on tissue source and disease. Statistical testing identified sets of genes that displayed differences between the 2 fat types. Western blot analysis was performed for protein expression of an identified gene of interest.Results.The 29 IFP demonstrated an elevation in the expression of adipokines such as adiponectin and leptin. A statistically significant increased expression was seen for genes of adipogenesis, such as peroxisome proliferator-activated receptor-γ (PPAR-γ), diacylglycerol acyltransferase 2 (DGAT2), cluster of differentiation (CD36), and thyroid hormone responsive spot (THRSP) in the severe OA fat pads as compared to the controls. A subset of 5 patients in the endstage OA group were consistently similar in gene expression to early OA tissue. Protein expression of PPAR-γ2 was 5.4-fold and PPAR-γ1 was 1.4-fold greater in endstage versus early OA tissue.Conclusion.Endstage OA fat pads demonstrated a significant upregulation of genes for fat metabolism and energy homeostasis and a mixed result for inflammatory cytokines.

The mechanical behavior of human femurs has been described in the literature with regard to torsion and tension but only as independent measurements. However, in this study, human femurs were subjected to torsion to determine if a simultaneous axial tensile load was generated. Fresh frozen human femurs (n=25) were harvested and stripped of soft tissue. Each femur was mounted rigidly in a specially designed test jig and remained at a fixed axial length during all experiments. Femurs were subjected to external and internal rotation applied at a constant angulation rate of 0.1 deg/s to a maximum torque of 12 N m. Applied torque and generated axial tension were monitored simultaneously. Outcome measurements were extracted from torsion-versus-tension graphs. There was a strong relationship between applied torsion and the resulting tension for external rotation tests (torsion/ tension ratio = 551.7 ± 283.8 mm, R 2 = 0.83 ± 0.20, n=25), internal rotation tests (torsion/tension ratio =495.3 ± 233.1 mm, R 2 = 0.87 ± 0.17, n = 24), left femurs (torsion/tension ratio =542.2 ±262.4 mm, R 2 =0.88 ± 0.13, n =24), and right femurs (torsion/tension ratio = 506.7 ± 260.0 mm, R 2 = 0.82 ± 0.22, n = 25). No statistically significant differences were found for external versus internal rotation groups or for left versus right femurs when comparing torsion/tension ratios (p = 0.85) or R 2 values (p =0.54). A strongly coupled linear relationship between torsion and tension for human femurs was exhibited. This suggests an interplay between these two factors during activities of daily living and injury processes.

Background: Topical application of tranexamic acid to bleeding wound surfaces reduces blood loss in patients undergoing some major surgeries, without systemic complications. The objective of the present trial was to assess the efficacy and safety of the topical application of tranexamic acid on postoperative blood loss in patients undergoing primary unilateral total knee arthroplasty with cement. Methods: In a prospective, double-blind, placebo-controlled trial, 124 patients were randomized to receive 1.5 or 3.0 g of tranexamic acid in 100 mL of normal saline solution or an equivalent volume of placebo (normal saline solution) applied into the joint for five minutes at the end of surgery. The primary outcome was blood loss calculated from the difference between the preoperative hemoglobin level and the corresponding lowest postoperative value or hemoglobin level prior to transfusion. The safety outcomes included Doppler ultrasound in all patients and measurement of plasma levels of tranexamic acid one hour after release of the tourniquet. Results: Twenty-five patients were withdrawn for various reasons; therefore, ninety-nine patients were included in the intention-to-treat analysis. The postoperative blood loss was reduced in the 1.5 and 3-g tranexamic acid groups (1295 mL [95% confidence interval, 1167 to 1422 mL] and 1208 mL [95% confidence interval, 1078 to 1339 mL], respectively) in comparison with the placebo group (1610 mL [95% confidence interval, 1480 to 1738 mL]) (p < 0.017). The postoperative hemoglobin levels were higher in the 1.5 and 3.0-g tranexamic acid groups (10.0 g/dL [95% confidence interval, 9.5 to 10.4 g/dL] and 10.1 g/dL [95% confidence interval, 9.8 to 10.5 g/dL], respectively) in comparison with the placebo group (8.6 g/dL [95% confidence interval, 8.2 to 9 g/dL]) (p < 0.017). With the numbers studied, there was no difference in the rates of deep-vein thrombosis or pulmonary embolism between the three groups. Minimal systemic absorption of tranexamic acid was observed. Conclusions: At the conclusion of a total knee arthroplasty with cement, topical application of tranexamic acid directly into the surgical wound reduced postoperative bleeding by 20% to 25%, or 300 to 400 mL, resulting in 16% to 17% higher postoperative hemoglobin levels compared with placebo, with no clinically important increase in complications being identified in the treatment groups. Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Objectives: The aim of the present study was to examine biomechanically 5 different construct combinations for fixation of ipsilateral intertrochanteric and femoral shaft fractures. Methods: Twenty-five fresh-frozen adult human femora (age range = 58-91 years, average age = 75.4 years) were tested in physiological bending and in torsion to characterize initial bending and torsional stiffness and stiffness following fixation of combined intertrochanteric and femoral shaft fractures. Five fracture fixation device constructs were assessed-construct A: long dynamic hip screw (long DHS); construct B: reconstruction nail; construct C: DHS plus low-contact dynamic compression plate; construct D: DHS plus retrograde intramedullary nail; and construct E: long intramedullary hip screw. Axial stiffness, torsional stiffness, and axial load-to-failure were the main measurements recorded. Results: There were no differences between constructs in terms of axial stiffness (P = 0.41), external rotation stiffness (P = 0.13), and axial load-to-failure (P = 0.16). However, there was a borderline statistically significant difference in internal rotation stiffness between the constructs (P = 0.048). Specifically, construct C was significantly stiffer than construct E (P = 0.04). Conclusions: All constructs showed no statistical differences when compared with one another, with the exception of construct E, which provided the least torsional stiffness. However, the current in vitro model did not simulate fracture healing or support offered by soft tissues, both of which would affect the stiffness and load-to-failure levels reached.

Background: Home-based rehabilitation is increasingly utilized to reduce health-care costs; however, with a shorter hospital stay, the possibility arises for an increase in adverse clinical outcomes. We evaluated the effectiveness and cost of care of home-based compared with inpatient rehabilitation following primary total hip or knee joint replacement. Methods: We randomized 234 patients, using block randomization techniques, to either home-based or inpatient rehabilitation following total joint replacement. All patients followed standardized care pathways and were evaluated, with use of validated outcome measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Short Form-36, and patient satisfaction), prior to surgery and at three and twelve months following surgery. The primary outcome was the WOMAC function score at three months after surgery. Results: The mean length of stay (and standard deviation) in the acute care hospital was 6.3 ± 2.5 days for the group designated for inpatient rehabilitation prior to transfer to that facility compared with 7.0 ± 3.0 days for the home-based rehabilitation group prior to discharge home (p = 0.06). The mean length of stay in inpatient rehabilitation was 17.7 ± 8.6 days. The mean number of postoperative home-based rehabilitation visits was eight. The prevalence of postoperative complications up to twelve months postoperatively was similar in both groups, which each had a 2% rate of dislocation and a 3% rate of clinically important deep venous thrombosis. The prevalence of infection was 0% in the home-based group and 2% in the inpatient group. None of these differences was clinically important. Both groups showed substantial improvements at three and twelve months, with no significant differences between the groups with respect to WOMAC, Short Form-36, or patient satisfaction scores (p > 0.05). The total episode-of-care costs (in Canadian dollars) for the inpatient rehabilitation and home-based rehabilitation arms were $14,532 and $11,082, respectively (p < 0.01). Conclusions: Despite concerns about early hospital discharge, there was no difference in pain, functional outcomes, or patient satisfaction between the group that received home-based rehabilitation and the group that had inpatient rehabilitation. On the basis of our findings, we recommend the use of a home-based rehabilitation protocol following elective primary total hip or knee replacement as it is the more cost-effective strategy. Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Staphylococcus aureus is a human commensal that colonizes the skin. While it is normally innocuous, it has strong associations with atopic dermatitis pathogenesis and has become the leading cause of skin and soft tissue infections in the United States. The factors that dictate the role of S. aureus in disease are still being determined. In this work, we utilized primary keratinocyte culture and an epidermal murine colonization model to investigate the role of S. aureus phenol-soluble modulins (PSMs) in proinflammatory cytokine release and inflammation induction. We demonstrated that many species of Staphylococcus are capable of causing release of interleukin 18 (IL-18) from keratinocytes and that S. aureus PSMs are necessary and sufficient to stimulate IL-18 release from keratinocytes independently of caspase 1. Further, after 7 days of epicutaneous exposure to wild-type S. aureus, but not S. aureus Δpsm, we saw dramatic changes in gross pathology, as well as systemic release of proinflammatory cytokines. This work demonstrates the importance of PSM peptides in S. aureus-mediated inflammatory cytokine release from keratinocytes in vitro and in vivo and further implicates PSMs as important contributors to pathogenesis.

This article reports the details of delayed hemolytic transfusion reactions in four patients with sickle cell disease. These cases demonstrate the characteristics of the reactions, the significant risks involved, and the principles useful in diagnosis and treatment. Patients with sickle cell disease are at particular risk for delayed hemolytic transfusion reactions because they may be transfused at intervals over many years; they frequently form alloantibodies because of antigenic differences from the donor population; and they may receive emergency care in different hospitals where transfusion records are not available. In addition, exchange transfusions, which are often used for patients with sickle cell disease and which were given in three of these cases, raise the risks through increased exposure to foreign erythrocyte antigens and through an increased volume of erythrocytes susceptible to hemolysis. It was concluded that the hazards of these transfusion reactions justify preventive measures, such as extended erythrocyte phenotyping of patients with sickle cell disease and extended phenotypic matching of transfused cells.

Inside-out membrane vesicles prepared from multidrug resistant human leukemic cells (CEM/VBL1000), but not from sensitive cells, transported [3H]-labelled vinblastine (VBL) in an ATP-dependent manner, reaching a plateau level by 15 min. The transport occurred with an apparent Km of 60 +/- 20nM. Verapamil (10 microM), and taxol (IC50 = 1 microM) prevented VBL uptake and evoked VBL diffusion from vesicles when added after VBL uptake had reached steady state. The channel forming agent alamethicin prevented net uptake of VBL and addition of alamethicin to the vesicles after the steady-state had been reached resulted in the rapid efflux of [3H]VBL. Very low concentrations of Triton X-100 (0.01 % v/v) also prevented net uptake of VBL, whilst addition of Triton X-100 and making the medium hypo-osmotic after the steady state had been reached caused the [3H]VBL to rapidly diffuse out of the vesicles. These observations indicate that VBL is actively transported into the lumen of inside-out vesicles from multidrug resistant leukaemia cells.

The case is described of a patient with complete small bowel obstruction 13 days after swallowing a condom containing hashish. Treatment by enzymatic dissolution was obviously impossible. The small bowel was emptied preoperatively by a Dennis long-tube, and the impacted bolus was removed by enterotomy.

Evidence is presented which indicates that blood leaving side branches of an internal mammary artery implanted into the anterior wall of the right ventricle flows from the tunnel in which it lies through myocardial sinusoidal spaces of the anterior right ventricular wall across the midline to fill corresponding spaces in the anterior wall of the left ventricle and thence is carried to the left coronary sinus. The myocardial sinusoidal spaces of right and left ventricles have been well outlined, using injections of polyvinyl acetate and the technique of digestion casts. We have been able to show that there is no barrier between the myocardial sinusoids of the right circulation and those related to the anterior descending branch of the left coronary artery. In structure, these myocardial sinusoidal spaces are quite different from the intramyocardial coronary arteriolar zones which, in 93% of human hearts, are separated from one another without collateral communication.The continuity of the right and left ventricular myocardial sinusoids explains why implantation of a right internal mammary artery into the anterior wall of the right ventricle combined with a corresponding left implant, epicardiectomy and free omental graft, has been so effective in our hands in the treatment of far-advanced human coronary artery insufficiency.