Colliding Hadrons as Cosmic Membranes and Possible Signatures of Lost Momentum

We argue that in the TeV-gravity scenario high energy hadrons colliding on the 3-brane embedded in D=4+n-dimensional spacetime, with n dimensions smaller than the hadron size, can be considered as cosmic membranes. In the 5-dimensional case these cosmic membranes produce effects similar to cosmic strings in the 4-dimensional world. We calculate the corrections to the eikonal approximation for the gravitational scattering of partons due to the presence of effective hadron cosmic membranes. Cosmic membranes dominate the momentum lost in the longitudinal direction for colliding particles that opens new channels for particle decays.Comment: 15 pages, Late

Could Public Restrooms Be an Environment for Bacterial Resistomes?

PMCID: PMC3547874This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Low Spigelian hernia in a 6-year-old boy presenting as an incarcerated inguinal hernia: a case report

<p>Abstract</p> <p>Introduction</p> <p>Lower Spigelian hernia is a very rare entity. The clinical findings are similar to those of inguinal hernias and in many cases may be misdiagnosed. In the literature, only a few references to this entity have been reported in children. To the best of our knowledge, this is the first case report of a lower Spigelian hernia in a child who presented with an acute painful scrotum.</p> <p>Case presentation</p> <p>We discuss the case of a 6-year-old Greek boy who presented to our emergency department complaining of severe pain in the left inguinal area and scrotum. The acute painful swelling started suddenly, without any obvious cause. The initial diagnosis was incarcerated inguinal hernia which was reduced with difficulty. Five days later, the patient still experienced mild pain during palpation and he was operated on. During the operation, a large lower Spigelian hernia was revealed and reconstructed.</p> <p>Conclusion</p> <p>Although Spigelian hernias are rare in children and difficult to diagnose, physicians should be aware of them and include them in the differential diagnosis.</p

Pneumococcal carriage in sub-Saharan Africa--a systematic review.

BACKGROUND: Pneumococcal epidemiology varies geographically and few data are available from the African continent. We assess pneumococcal carriage from studies conducted in sub-Saharan Africa (sSA) before and after the pneumococcal conjugate vaccine (PCV) era. METHODS: A search for pneumococcal carriage studies published before 2012 was conducted to describe carriage in sSA. The review also describes pneumococcal serotypes and assesses the impact of vaccination on carriage in this region. RESULTS: Fifty-seven studies were included in this review with the majority (40.3%) from South Africa. There was considerable variability in the prevalence of carriage between studies (I-squared statistic = 99%). Carriage was higher in children and decreased with increasing age, 63.2% (95% CI: 55.6-70.8) in children less than 5 years, 42.6% (95% CI: 29.9-55.4) in children 5-15 years and 28.0% (95% CI: 19.0-37.0) in adults older than 15 years. There was no difference in the prevalence of carriage between males and females in 9/11 studies. Serotypes 19F, 6B, 6A, 14 and 23F were the five most common isolates. A meta-analysis of four randomized trials of PCV vaccination in children aged 9-24 months showed that carriage of vaccine type (VT) serotypes decreased with PCV vaccination; however, overall carriage remained the same because of a concomitant increase in non-vaccine type (NVT) serotypes. CONCLUSION: Pneumococcal carriage is generally high in the African continent, particularly in young children. The five most common serotypes in sSA are among the top seven serotypes that cause invasive pneumococcal disease in children globally. These serotypes are covered by the two PCVs recommended for routine childhood immunization by the WHO. The distribution of serotypes found in the nasopharynx is altered by PCV vaccination

Subcoronary versus supracoronary aortic stenosis. an experimental evaluation

<p>Abstract</p> <p>Background</p> <p>Valvular aortic stenosis is the most common cause of left ventricular hypertrophy due to gradually increasing pressure work. As the stenosis develop the left ventricular hypertrophy may lead to congestive heart failure, increased risk of perioperative complications and also increased risk of sudden death. A functional porcine model imitating the pathophysiological nature of valvular aortic stenosis is very much sought after in order to study the geometrical and pathophysiological changes of the left ventricle, timing of surgery and also pharmacological therapy in this patient group.</p> <p>Earlier we developed a porcine model for aortic stenosis based on supracoronary aortic banding, this model may not completely imitate the pathophysiological changes that occurs when valvular aortic stenosis is present including the coronary blood flow. It would therefore be desirable to optimize this model according to the localization of the stenosis.</p> <p>Methods</p> <p>In 20 kg pigs subcoronary (n = 8), supracoronary aortic banding (n = 8) or sham operation (n = 4) was preformed via a left lateral thoracotomy. The primary endpoint was left ventricular wall thickness; secondary endpoints were heart/body weight ratio and the systolic/diastolic blood flow ratio in the left anterior descending coronary. Statistical evaluation by oneway anova and unpaired t-test.</p> <p>Results</p> <p>Sub- and supracoronary banding induce an equal degree of left ventricular hypertrophy compared with the control group. The coronary blood flow ratio was slightly but not significantly higher in the supracoronary group (ratio = 0.45) compared with the two other groups (subcoronary ratio = 0.36, control ratio = 0.34).</p> <p>Conclusions</p> <p>A human pathophysiologically compatible porcine model for valvular aortic stenosis was developed by performing subcoronary aortic banding. Sub- and supracoronary aortic banding induce an equal degree of left ventricular hypertrophy. This model may be valid for experimental investigations of aortic valve stenosis but studies of left ventricular hypertrophy can be studied equally well by graduated constriction of the ascending aorta.</p

Blood pressure reduction and clinical outcomes with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers: protocol for a systematic review and meta-regression analysis

Background Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs) efficaciously reduce systolic blood pressure (BP), a well-established risk factor for myocardial infarction (MI). Both inhibit the renin-angiotensin system, albeit through different mechanisms, and produce similar reductions in BP. However, in parallel meta-analyses of ACEi and ARB trials, ACEis reduce risk of MI whereas ARBs do not—a phenomenon described as the ‘ARB-MI paradox’. In addition, ACEis reduce all-cause mortality, whereas ARBs do not, which appears to be independent of BP lowering. The divergent cardiovascular effects of ACE inhibitors and ARBs, despite similar BP reductions, are counter-intuitive. This systematic review aims to ascertain the extent to which clinical outcomes in randomised trials of ACEi and ARBs are attributable to reductions in systolic BP. Methods A comprehensive search of bibliographic databases will be performed to identify all randomised studies of agents of the ACEi and ARB class. Placebo and active comparator-controlled studies that report clinical outcomes, with greater than 500 person-years of follow-up in each study arm, will be included. Two independent reviewers will screen study records against a priori-defined eligibility criteria and perform data extraction. The Cochrane Risk of Bias Tool will be applied to all included studies. Studies retracted subsequent to initial publication will be excluded. Primary outcomes of interest include MI and all-cause mortality; secondary outcomes include stroke, heart failure, revascularisation and cardiovascular mortality. Meta-regression will be performed, evaluating the relationship between attained reduction in systolic BP and relative risk of each outcome, stratified by drug class. Where a BP-dependent effect exists (two-tailed p value < 0.05), relative risks, standardised per 10 mmHg difference in BP, will be reported for each study outcome. Publication bias will be examined using Funnel plots, and calculation of Egger’s statistic. Discussion This systematic review will provide a detailed synthesis of evidence regarding the relationship between BP reduction and clinical outcomes with ACEi and ARBs. Greater understanding of the dependency of the effect of each class on BP reduction will advance insight into the nature of the ARB-MI paradox and guide the future usage of these agents. Systematic review registration PROSPERO CRD4201707298

Teaching clinical informatics to third-year medical students: negative results from two controlled trials

BACKGROUND: Prior educational interventions to increase seeking evidence by medical students have been unsuccessful. METHODS: We report two quasirandomized controlled trials to increase seeking of medical evidence by third-year medical students. In the first trial (1997–1998), we placed computers in clinical locations and taught their use in a 6-hour course. Based on negative results, we created SUMSearch(TM), an Internet site that automates searching for medical evidence by simultaneous meta-searching of MEDLINE and other sites. In the second trial (1999–2000), we taught SUMSearch's use in a 5½-hour course. Both courses were taught during the medicine clerkship. For each trial, we surveyed the entire third-year class at 6 months, after half of the students had taken the course (intervention group). The students who had not received the intervention were the control group. We measured self-report of search frequency and satisfaction with search quality and speed. RESULTS: The proportion of all students who reported searching at least weekly for medical evidence significantly increased from 19% (1997–1998) to 42% (1999–2000). The proportion of all students who were satisfied with their search results increased significantly between study years. However, in neither study year did the interventions increase searching or satisfaction with results. Satisfaction with the speed of searching was 27% in 1999–2000. This did not increase between studies years and was not changed by the interventions. CONCLUSION: None of our interventions affected searching habits. Even with automated searching, students report low satisfaction with search speed. We are concerned that students using current strategies for seeking medical evidence will be less likely to seek and appraise original studies when they enter medical practice and have less time

Low pH immobilizes and kills human leukocytes and prevents transmission of cell-associated HIV in a mouse model

BACKGROUND: Both cell-associated and cell-free HIV virions are present in semen and cervical secretions of HIV-infected individuals. Thus, topical microbicides may need to inactivate both cell-associated and cell-free HIV to prevent sexual transmission of HIV/AIDS. To determine if the mild acidity of the healthy vagina and acid buffering microbicides would prevent transmission by HIV-infected leukocytes, we measured the effect of pH on leukocyte motility, viability and intracellular pH and tested the ability of an acidic buffering microbicide (BufferGel(®)) to prevent the transmission of cell-associated HIV in a HuPBL-SCID mouse model. METHODS: Human lymphocyte, monocyte, and macrophage motilities were measured as a function of time and pH using various acidifying agents. Lymphocyte and macrophage motilities were measured using video microscopy. Monocyte motility was measured using video microscopy and chemotactic chambers. Peripheral blood mononuclear cell (PBMC) viability and intracellular pH were determined as a function of time and pH using fluorescent dyes. HuPBL-SCID mice were pretreated with BufferGel, saline, or a control gel and challenged with HIV-1-infected human PBMCs. RESULTS: Progressive motility was completely abolished in all cell types between pH 5.5 and 6.0. Concomitantly, at and below pH 5.5, the intracellular pH of PBMCs dropped precipitously to match the extracellular medium and did not recover. After acidification with hydrochloric acid to pH 4.5 for 60 min, although completely immotile, 58% of PBMCs excluded ethidium homodimer-1 (dead-cell dye). In contrast, when acidified to this pH with BufferGel, a microbicide designed to maintain vaginal acidity in the presence of semen, only 4% excluded dye at 10 min and none excluded dye after 30 min. BufferGel significantly reduced transmission of HIV-1 in HuPBL-SCID mice (1 of 12 infected) compared to saline (12 of 12 infected) and a control gel (5 of 7 infected). CONCLUSION: These results suggest that physiologic or microbicide-induced acid immobilization and killing of infected white blood cells may be effective in preventing sexual transmission of cell-associated HIV

Retinal glycoprotein enrichment by concanavalin a enabled identification of novel membrane autoantigen synaptotagmin-1 in equine recurrent uveitis.

Complete knowledge of autoantigen spectra is crucial for understanding pathomechanisms of autoimmune diseases like equine recurrent uveitis (ERU), a spontaneous model for human autoimmune uveitis. While several ERU autoantigens were identified previously, no membrane protein was found so far. As there is a great overlap between glycoproteins and membrane proteins, the aim of this study was to test whether pre-enrichment of retinal glycoproteins by ConA affinity is an effective tool to detect autoantigen candidates among membrane proteins. In 1D Western blots, the glycoprotein preparation allowed detection of IgG reactions to low abundant proteins in sera of ERU patients. Synaptotagmin-1, a Ca2+-sensing protein in synaptic vesicles, was identified as autoantigen candidate from the pre-enriched glycoprotein fraction by mass spectrometry and was validated as a highly prevalent autoantigen by enzyme-linked immunosorbent assay. Analysis of Syt1 expression in retinas of ERU cases showed a downregulation in the majority of ERU affected retinas to 24%. Results pointed to a dysregulation of retinal neurotransmitter release in ERU. Identification of synaptotagmin-1, the first cell membrane associated autoantigen in this spontaneous autoimmune disease, demonstrated that examination of tissue fractions can lead to the discovery of previously undetected novel autoantigens. Further experiments will address its role in ERU pathology