Molecular Mechanisms Involved in Vascular Interactions of the Lyme Disease Pathogen in a Living Host

Hematogenous dissemination is important for infection by many bacterial pathogens, but is poorly understood because of the inability to directly observe this process in living hosts at the single cell level. All disseminating pathogens must tether to the host endothelium despite significant shear forces caused by blood flow. However, the molecules that mediate tethering interactions have not been identified for any bacterial pathogen except E. coli, which tethers to host cells via a specialized pillus structure that is not found in many pathogens. Furthermore, the mechanisms underlying tethering have never been examined in living hosts. We recently engineered a fluorescent strain of Borrelia burgdorferi, the Lyme disease pathogen, and visualized its dissemination from the microvasculature of living mice using intravital microscopy. We found that dissemination was a multistage process that included tethering, dragging, stationary adhesion and extravasation. In the study described here, we used quantitative real-time intravital microscopy to investigate the mechanistic features of the vascular interaction stage of B. burgdorferi dissemination. We found that tethering and dragging interactions were mechanistically distinct from stationary adhesion, and constituted the rate-limiting initiation step of microvascular interactions. Surprisingly, initiation was mediated by host Fn and GAGs, and the Fn- and GAG-interacting B. burgdorferi protein BBK32. Initiation was also strongly inhibited by the low molecular weight clinical heparin dalteparin. These findings indicate that the initiation of spirochete microvascular interactions is dependent on host ligands known to interact in vitro with numerous other bacterial pathogens. This conclusion raises the intriguing possibility that fibronectin and GAG interactions might be a general feature of hematogenous dissemination by other pathogens

PD-L1 expression in EBV-negative diffuse large B-cell lymphoma: clinicopathologic features and prognostic implications

Programmed cell death ligand 1 (PD-L1) is a cell surface glycoprotein that regulates the cellular immune response and serves as a targetable immune checkpoint molecule. PD-L1 is expressed on tumor cells and the immune microenvironment of several human malignancies, including a subset of aggressive lymphomas. We sought to investigate further the clinical and pathologic features of EBV-negative diffuse large B-cell lymphoma (DLBCL) cases that express PD-L1. Immunohistochemical staining using an anti-PD-L1 monoclonal antibody was performed on DLBCL cases from 86 patients. These patients received standard chemotherapy treatment and were followed for up to 175 months. Overall, 14 cases (16%) were considered positive for PD-L1 in tumor cells. In comparison with PD-L1 negative cases, PD-L1 positive cases had a higher rate of non-GCB type (71% vs. 30%, P=0.0060), and higher Ann Arbor stage (II-IV) (100% vs. 73%, P=0.0327). No significant differences were seen in the immunohistochemical expression of BCL2, MYC, or Ki67. Patients with tumors expressing PD-L1 demonstrated inferior overall survival (OS) upon long term follow up (P=0.0447). Both age/sex-adjusted and multivariate analyses identified PD-L1 as an independent predictor for OS (P=0.0101 and P=0.0424). There was no significant difference, however, in terms of remission rates after first treatment, relapse rates, and progression free survival between the groups. Identification of DLBCL cases that express PD-L1 may serve to select a subset of patients that could further benefit from targeted immunotherapy

Extranuclear structural components that mediate dynamic chromosome movements in yeast meiosis

Telomere-led rapid chromosome movements or rapid prophase movements direct fundamental meiotic processes required for successful haploidization of the genome. Critical components of the machinery that generates rapid prophase movements are unknown, and the mechanism underlying rapid prophase movements remains poorly understood. We identified S. cerevisiae Mps2 as the outer nuclear membrane protein that connects the LINC complex with the cytoskeleton. We also demonstrate that the motor Myo2 works together with Mps2 to couple the telomeres to the actin cytoskeleton. Further, we show that Csm4 interacts with Mps2 and is required for perinuclear localization of Myo2, implicating Csm4 as a regulator of the Mps2-Myo2 interaction. We propose a model in which the newly identified functions of Mps2 and Myo2 cooperate with Csm4 to drive chromosome movements in meiotic prophase by coupling telomeres to the actin cytoskeleton.Fil: Lee, Chih Ying. Oklahoma Medical Research Foundation; Estados UnidosFil: Bisig, Carlos Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Conrad, Michael M.. Oklahoma Medical Research Foundation; Estados UnidosFil: Ditamo, Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Previato de Almeida, Luciana. Oklahoma Medical Research Foundation; Estados UnidosFil: Dresser, Michael E.. Oklahoma Medical Research Foundation; Estados UnidosFil: Pezza, Roberto J.. Oklahoma Medical Research Foundation; Estados Unido

Sterilization of men with intellectual disabilities: whose best interest is it anyway?

This article examines the ethical and legal issues raised by the involuntary sterilization of men with intellectual disability. It traces how, after the demise of eugenic reasoning, social policies of normalization and care in the community provided new justifications for sterilizations. It also examines how, ironically, modern arguments about promoting male sexual freedom have come to be used as a justification to sterilize. Through examination of recent cases on the sterilization of men with intellectual disabilities, this article explores the legal framework of the ‘best interests’ test and the ‘least restrictive alternative’ provisions in the Mental Capacity Act 2005 and argues that sterilization is usually unnecessary, disproportionate and not the least restrictive option. It also argues that the least restrictive alternative provisions contained in the 2005 Act need to be more rigorously applied

Fulvestrant: pharmacokinetics and pharmacology

Fulvestrant is a new type of oestrogen receptor (ER) antagonist with no agonist activity and a novel pharmacological profile. Fulvestrant has been shown to significantly reduce cellular levels of the ER and progesterone receptor in both preclinical studies and in clinical trials of postmenopausal women with primary breast cancer. This paper reviews the pharmacokinetics and metabolism of fulvestrant, which support the rationale for drug delivery as a single, once-monthly intramuscular injection, and show that this agent has minimal potential to be the subject, or cause, of significant cytochrome p450-mediated drug interactions

Clarifying the importance of CYP2C19 and PON1 in the mechanism of clopidogrel bioactivation and in vivo antiplatelet response

AimsIt is thought that clopidogrel bioactivation and antiplatelet response are related to cytochrome P450 2C19 (CYP2C19). However, a recent study challenged this notion by proposing CYP2C19 as wholly irrelevant, while identifying paraoxonase-1 (PON1) and its Q192R polymorphism as the major driver of clopidogrel bioactivation and efficacy. The aim of this study was to systematically elucidate the mechanism and relative contribution of PON1 in comparison to CYP2C19 to clopidogrel bioactivation and antiplatelet response.Methods and resultsFirst, the influence of CYP2C19 and PON1 polymorphisms and plasma paraoxonase activity on clopidogrel active metabolite (H4) levels and antiplatelet response was assessed in a cohort of healthy subjects (n = 21) after administration of a single 75 mg dose of clopidogrel. There was a remarkably good correlation between H4 AUC (0-8 h) and antiplatelet response (r2 = 0.78). Furthermore, CYP2C19 but not PON1 genotype was predictive of H4 levels and antiplatelet response. There was no correlation between plasma paraoxonase activity and H4 levels. Secondly, metabolic profiling of clopidogrel in vitro confirmed the role of CYP2C19 in bioactivating clopidogrel to H4. However, heterologous expression of PON1 in cell-based systems revealed that PON1 cannot generate H4, but mediates the formation of another thiol metabolite, termed Endo. Importantly, Endo plasma levels in humans are nearly 20-fold lower than H4 and was not associated with any antiplatelet response.ConclusionOur results demonstrate that PON1 does not mediate clopidogrel active metabolite formation or antiplatelet action, while CYP2C19 activity and genotype remains a predictor of clopidogrel pharmacokinetics and antiplatelet response. © 2012 The Author

Transgenic Bcl-3 slows T cell proliferation

Immunological adjuvants, such as bacterial LPS, increase the mRNA levels of the IkB-related NF-κB transcriptional transactivator, Bcl-3, in activated T cells. Adjuvants also increase the life expectancy of activated T cells, as does over-expression of Bcl-3, suggesting that Bcl-3 is part of the pathway whereby adjuvants affect T cell lifespans. However, previous reports, confirmed here, show that adjuvants also increase the life expectancies of Bcl-3-deficient T cells, making Bcl-3’s role and effects in adjuvant-induced survival uncertain. To investigate the functions of Bcl-3 further, here we confirm the adjuvant-induced expression of Bcl-3 mRNA and show Bcl-3 induction at the protein level. Bcl-3 was expressed in mice via a transgene driven by the human CD2 promoter. Like other protective events, over-expression of Bcl-3 slows T cell activation very early in T cell responses to antigen, both in vitro and in vivo. This property was intrinsic to the T cells over-expressing the Bcl-3 and did not require Bcl-3 expression by other cells such as antigen-presenting cells

TGF-β in tolerance, development and regulation of immunity

AbstractThe TGF-β superfamily is an ancient metazoan protein class which cuts across cell and tissue differentiation, developmental biology and immunology. Its many members are regulated at multiple levels from intricate control of gene transcription, post-translational processing and activation, and signaling through overlapping receptor structures and downstream intracellular messengers. We have been interested in TGF-β homologues firstly as key players in the induction of immunological tolerance, the topic so closely associated with Ray Owen. Secondly, our interests in how parasites may manipulate the immune system of their host has also brought us to study the TGF-β pathway in infections with longlived, essentially tolerogenic, helminth parasites. Finally, within the spectrum of mammalian TGF-β proteins is an exquisitely tightly-regulated gene, anti-Müllerian hormone (AMH), whose role in sex determination underpins the phenotype of freemartin calves that formed the focus of Ray’s seminal work on immunological tolerance

The Effectiveness of Passive Physical Modalities for the Management of Soft Tissue Injuries and Neuropathies of the Wrist and Hand: A Systematic Review by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration

AbstractObjectiveThe purpose of this systematic review was to determine the effectiveness of passive physical modalities compared to other interventions, placebo/sham interventions, or no intervention in improving self-rated recovery, functional recovery, clinical outcomes and/or administrative outcomes (eg, time of disability benefits) in adults and/or children with soft tissue injuries and neuropathies of the wrist and hand.MethodsWe systematically searched MEDLINE, EMBASE, PsycINFO, and the Cochrane Central Register of Controlled Trials, accessed through Ovid Technologies, Inc, and CINAHL Plus with Full Text, accessed through EBSCO host, from 1990 to 2015. Our search strategies combined controlled vocabulary relevant to each database (eg, MeSH for MEDLINE) and text words relevant to our research question and the inclusion criteria. Randomized controlled trials, cohort studies, and case-control studies were eligible. Random pairs of independent reviewers screened studies for relevance and critically appraised relevant studies using the Scottish Intercollegiate Guidelines Network criteria. Studies with low risk of bias were synthesized following best evidence synthesis principles.ResultsWe screened 6618 articles and critically appraised 11 studies. Of those, 7 had low risk of bias: 5 addressed carpal tunnel syndrome (CTS) and 2 addressed de Quervain disease. We found evidence that various types of night splints lead to similar outcomes for the management of CTS. The evidence suggests that a night wrist splint is less effective than surgery in the short term but not in the long term. Furthermore, a night wrist splint and needle electroacupuncture lead to similar outcomes immediately postintervention. Finally, low-level laser therapy and placebo low-level laser therapy lead to similar outcomes. The evidence suggests that kinesio tape or a thumb spica cast offers short-term benefit for the management of de Quervain disease. Our search did not identify any low risk of bias studies examining the effectiveness of passive physical modalities for the management of other soft tissue injuries or neuropathies of the wrist and hand.ConclusionsDifferent night orthoses provided similar outcomes for CTS. Night orthoses offer similar outcomes to electroacupuncture but are less effective than surgery in the short term. This review suggests that kinesio tape or a thumb spica cast may offer short-term benefit for the management of de Quervain disease