860 research outputs found
MCL-1 is essential for survival but dispensable for metabolic fitness of FOXP3+ regulatory T cells
FOXP3+ regulatory T (Treg) cells are essential for maintaining immunological tolerance. Given their importance in immune-related diseases, cancer and obesity, there is increasing interest in targeting the Treg cell compartment therapeutically. New pharmacological inhibitors that specifically target the prosurvival protein MCL-1 may provide this opportunity, as Treg cells are particularly reliant upon this protein. However, there are two distinct isoforms of MCL-1; one located at the outer mitochondrial membrane (OMM) that is required to antagonize apoptosis, and another at the inner mitochondrial membrane (IMM) that is reported to maintain IMM structure and metabolism via ATP production during oxidative phosphorylation. We set out to elucidate the relative importance of these distinct biological functions of MCL-1 in Treg cells to assess whether MCL-1 inhibition might impact upon the metabolism of cells able to resist apoptosis. Conditional deletion of Mcl1 in FOXP3+ Treg cells resulted in a lethal multiorgan autoimmunity due to the depletion of the Treg cell compartment. This striking phenotype was completely rescued by concomitant deletion of the apoptotic effector proteins BAK and BAX, indicating that apoptosis plays a pivotal role in the homeostasis of Treg cells. Notably, MCL-1-deficient Treg cells rescued from apoptosis displayed normal metabolic capacity. Moreover, pharmacological inhibition of MCL-1 in Treg cells resistant to apoptosis did not perturb their metabolic function. We conclude that Treg cells require MCL-1 only to antagonize apoptosis and not for metabolism. Therefore, MCL-1 inhibition could be used to manipulate Treg cell survival for clinical benefit without affecting the metabolic fitness of cells resisting apoptosis
Access Impediments to Health Care and Social Services Between Anglophone and Francophone African Immigrants Living in Philadelphia with Respect to HIV/AIDS
Objectives To describe the social and cultural differences between Anglophone and Francophone African immigrants which define the impediments that Francophone African immigrants face trying to access health and human services in Philadelphia, Pennsylvania. Methods Surveys and personal interviews were administered to participants in social events, community meetings, and health centers. A Chi-squared analysis was used to contrast the communities. Results Francophone Africans demonstrated less acculturation, education, English fluency, and more legal documentation problems, and thus face greater challenges accessing health care. Anglophone Africans had a higher level of acculturation, fewer language problems, and perceived fewer barriers in accessing health care than Francophone Africans. Conclusions Educating new immigrants, through a more culturally sensitive infectious disease treatment and prevention program, is integral to achieving a higher access and utilization rates of available services; especially in recent Francophone immigrants. A larger study is needed to extend the findings to other cities where immigrants with similar backgrounds or acculturation issues reside
Appointing Women to Boards: Is There a Cultural Bias?
Companies that are serious about corporate governance and business ethics are turning their attention to gender diversity at the most senior levels of business (Institute of Business Ethics, Business Ethics Briefing 21:1, 2011). Board gender diversity has been the subject of several studies carried out by international organizations such as Catalyst (Increasing gender diversity on boards: Current index of formal approaches, 2012), the World Economic Forum (Hausmann et al., The global gender gap report, 2010), and the European Board Diversity Analysis (Is it getting easier to find women on European boards? 2010). They all lead to reports confirming the overall relatively low proportion of women on boards and the slow pace at which more women are being appointed. Furthermore, the proportion of women on corporate boards varies much across countries. Based on institutional theory, this study hypothesizes and tests whether this variation can be attributed to differences in cultural settings across countries. Our analysis of the representation of women on boards for 32 countries during 2010 reveals that two cultural characteristics are indeed associated with the observed differences. We use the cultural dimensions proposed by Hofstede (Culture’s consequences: International differences in work-related values, 1980) to measure this construct. Results show that countries which have the greatest tolerance for inequalities in the distribution of power and those that tend to value the role of men generally exhibit lower representations of women on boards
Inhibition of IFN-γ-dependent antiviral airway epithelial defense by cigarette smoke
<p>Abstract</p> <p>Background</p> <p>Although individuals exposed to cigarette smoke are more susceptible to respiratory infection, the effects of cigarette smoke on lung defense are incompletely understood. Because airway epithelial cell responses to type II interferon (IFN) are critical in regulation of defense against many respiratory viral infections, we hypothesized that cigarette smoke has inhibitory effects on IFN-γ-dependent antiviral mechanisms in epithelial cells in the airway.</p> <p>Methods</p> <p>Primary human tracheobronchial epithelial cells were first treated with cigarette smoke extract (CSE) followed by exposure to both CSE and IFN-γ. Epithelial cell cytotoxicity and IFN-γ-induced signaling, gene expression, and antiviral effects against respiratory syncytial virus (RSV) were tested without and with CSE exposure.</p> <p>Results</p> <p>CSE inhibited IFN-γ-dependent gene expression in airway epithelial cells, and these effects were not due to cell loss or cytotoxicity. CSE markedly inhibited IFN-γ-induced Stat1 phosphorylation, indicating that CSE altered type II interferon signal transduction and providing a mechanism for CSE effects. A period of CSE exposure combined with an interval of epithelial cell exposure to both CSE and IFN-γ was required to inhibit IFN-γ-induced cell signaling. CSE also decreased the inhibitory effect of IFN-γ on RSV mRNA and protein expression, confirming effects on viral infection. CSE effects on IFN-γ-induced Stat1 activation, antiviral protein expression, and inhibition of RSV infection were decreased by glutathione augmentation of epithelial cells using N-acetylcysteine or glutathione monoethyl ester, providing one strategy to alter cigarette smoke effects.</p> <p>Conclusions</p> <p>The results indicate that CSE inhibits the antiviral effects of IFN-γ, thereby presenting one explanation for increased susceptibility to respiratory viral infection in individuals exposed to cigarette smoke.</p
Computer simulation of breast reduction surgery
Background: Plastic surgery of the breast, particularly breast reduction, is considered difficult. It can become a challenge for a less experienced surgeon to understand
exactly what to do when facing a particular type of breast
and how to avoid unsatisfactory results.
Methods: The goal of this study was to create a computer
model of the breast that provides a basis for the simulation
of breast surgery, particularly breast reduction. The
reconstruction of elastic parameters is based on observations of the breast with the patient in different positions.
Results: It is shown that several measurements with the
patient in different positions allow one to choose the
parameters of the model and determine the elastic coefficients of the breast and the skin. The geometry of the breast before and after surgery is simulated. A qualitative study of the incision parameters’ influence on the final geometry of the breast is presented.
Conclusion: The developed methodology and software
allow one to estimate the form of the breast after the surgery by knowing its form before surgery and taking into
consideration the parameters of incision applied by the
surgeon at the time of surgery. The described approach can be used for the qualitative and quantitative study of breast reduction surgery with a satisfactory result.
Level of Evidence: V (This journal requires that authors
assign a level of evidence to each article. For a full
description of these Evidence-Based Medicine ratings,
please refer to the Table of Contents or the online
Instructions to Authors http://www.springer.com/00266.
Molecular characterisation of protist parasites in human-habituated mountain gorillas (Gorilla beringei beringei), humans and livestock, from Bwindi impenetrable National Park, Uganda
Over 60 % of human emerging infectious diseases are zoonotic, and there is growing evidence of the zooanthroponotic transmission of diseases from humans to livestock and wildlife species, with major implications for public health, economics, and conservation. Zooanthroponoses are of relevance to critically endangered species; amongst these is the mountain gorilla (Gorilla beringei beringei) of Uganda. Here, we assess the occurrence of Cryptosporidium, Cyclospora, Giardia, and Entamoeba infecting mountain gorillas in the Bwindi Impenetrable National Park (BINP), Uganda, using molecular methods. We also assess the occurrence of these parasites in humans and livestock species living in overlapping/adjacent geographical regions
Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain
The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn^(2+) into the prefrontal cortex indicated that DAT KO mice have a truncated Mn^(2+) distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn^(2+) transport into more posterior midbrain nuclei and contralateral mesolimbic structures at 26 hr post-injection. Thus, DAT KO mice appear, at this level of anatomic resolution, to have preserved cortico-striatal-thalamic connectivity but diminished robustness of reward-modulating circuitry distal to the thalamus. This is in contradistinction to the state of this circuitry in serotonin transporter KO mice where we observed more robust connectivity in more posterior brain regions using methods identical to those employed here
Association between subclinical thyroid dysfunction and change in bone mineral density in prospective cohorts
Background Subclinical hyperthyroidism (SHyper) has been associated with increased risk of hip and other fractures, but the linking mechanisms remain unclear. Objective To investigate the association between subclinical thyroid dysfunction and bone loss. Methods Individual participant data analysis was performed after a systematic literature search in MEDLINE/EMBASE (1946–2016). Two reviewers independently screened and selected prospective cohorts providing baseline thyroid status and serial bone mineral density (BMD) measurements. We classified thyroid status as euthyroidism (thyroid-stimulating hormone [TSH] 0.45–4.49 mIU/L), SHyper (TSH < 0.45 mIU/L) and subclinical hypothyroidism (SHypo, TSH ≥ 4.50–19.99 mIU/L) both with normal free thyroxine levels. Our primary outcome was annualized percentage BMD change (%ΔBMD) from serial dual X-ray absorptiometry scans of the femoral neck, total hip and lumbar spine, obtained from multivariable regression in a random-effects two-step approach. Results Amongst 5458 individuals (median age 72 years, 49.1% women) from six prospective cohorts, 451 (8.3%) had SHypo and 284 (5.2%) had SHyper. During 36 569 person-years of follow-up, those with SHyper had a greater annual bone loss at the femoral neck versus euthyroidism: %ΔBMD = −0.18 (95% CI: −0.34, −0.02; I2 = 0%), with a nonstatistically significant pattern at the total hip: %ΔBMD = −0.14 (95% CI: −0.38, 0.10; I2 = 53%), but not at the lumbar spine: %ΔBMD = 0.03 (95% CI: −0.30, 0.36; I2 = 25%); especially participants with TSH < 0.10 mIU/L showed an increased bone loss in the femoral neck (%Δ BMD = −0.59; [95% CI: −0.99, −0.19]) and total hip region (%ΔBMD = −0.46 [95% CI: −1.05, −0.13]). In contrast, SHypo was not associated with bone loss at any site. Conclusion Amongst adults, SHyper was associated with increased femoral neck bone loss, potentially contributing to the increased fracture risk
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