Quantitative Doppler tissue imaging as a correlate of left ventricular contractility

Doppler tissue imaging is a new noninvasive imaging modality that allows quantitation of the low intensity, high amplitude Doppler shifts in the range of myocardial tissue motion. This study was performed to test the hypothesis that Doppler tissue imaging may provide unique information reflecting left ventricular systolic function, and to test the relationship between myocardial tissue velocity and noninvasive measures of ventricular contractility. Nine patients with mild or moderate mitral insufficiency and no regional wall motion abnormality were studied during dobutamine stress echocardiography. Left ventricular ejection fraction and peak systolic velocity of the sub- endocardial left ventricular posterior wall were quantified at baseline and at peak stress and compared with estimated peak dP/dt. During dobutamine infusion, ejection fraction increased from 41.7±22.2 (range 14 to 70) % to 56.6±27.9 (range 17 to 84) % (p=0.001), peak systolic velocity increased from 22.7±4.2 (range 18 to 28) mm/sec to 35.3±10.1 (range 20 to 47) mm/sec (p=0.004), and dP/dt increased from 1050±322 (range 613 to 1574) mm Hg/sec to 1766±768 (range 936 to 3000) mm Hg/sec (p=0.01). Although there were good correlations between left ventricular dP/dt and both ejection fraction (R=0.75) and peak systolic velocity (R=0.81), the correlation between change in dP/dt and change in myocardial velocity (R=0.75) was better than that between change in dP/dt and change in ejection fraction (R=0.36). These data support the hypothesis that myocardial velocity determined with Doppler tissue imaging reflects myocardial contractility, and that catecholamine- induced alteration in contractility is better reflected by changes in myocardial velocity than by changes in ejection fraction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42539/1/10554_2005_Article_BF01806222.pd

Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis

Background More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+)to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.Methods In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.Findings We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+.After 5\u20138 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0\ub717, 95% CI 0\ub711\u20130\ub725) among girls aged 13\u201319 years, and decreased significantly by 66% (RR 0\ub734, 95% CI 0\ub723\u20130\ub749) among women aged 20\u201324 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0\ub746, 95% CI 0\ub733\u20130\ub766) among girls aged 13\u201319 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0\ub733, 95% CI 0\ub724\u20130\ub746) among girls aged 15\u201319 years, decreased significantly by 54% (RR 0\ub746, 95% CI 0.36\u20130.60) among women aged 20\u201324 years, and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub753\u20130\ub789) among women aged 25\u201329 years. Among boys aged 15\u201319 years anogenital wart diagnoses decreased significantly by 48% (RR 0\ub752, 95% CI 0\ub737\u20130\ub775) and among men aged 20\u201324 years they decreased significantly by 32% (RR 0\ub768, 95% CI 0\ub747\u20130\ub798). After 5\u20139 years of vaccination, CIN2+ decreased significantly by 51% (RR 0\ub749, 95% CI 0\ub742\u20130\ub758) among screened girls aged 15\u201319 years and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub757\u20130\ub784) among women aged 20\u201324 years.Interpretation This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects

Learning to mark: a qualitative study of the experiences and concerns of medical markers

BACKGROUND: Although there is published research on the methods markers use in marking various types of assessment, there is relatively little information on the processes markers use in approaching a marking exercise. This qualitative paper describes the preparation and experiences of general practice (GP) teachers who undertake marking a written assessment in an undergraduate medical course. METHODS: Semi-structured interviews were conducted with seven of the 16 GP tutors on an undergraduate course. The purposive sample comprised two new markers, two who had marked for a couple of years and three experienced markers. Each respondent was interviewed twice, once following a formative assessment of a written case study, and again after a summative assessment. All interviews were audio-taped and analysed for emerging themes. A respondent validation exercise was conducted with all 16 GP tutors. RESULTS: Markers had internal concerns about their ability to mark fairly and made considerable efforts to calibrate their marking. They needed guidance and coaching when marking for the first time and adopted a variety of marking styles, reaching a decision through a number of routes. Dealing with pass/fail borderline scripts and the consequences of the mark on the student were particular concerns. Even experienced markers felt the need to calibrate their marks both internally and externally CONCLUSION: Previous experience of marking appears to improve markers' confidence and is a factor in determining the role which markers adopt. Confidence can be improved by giving clear instructions, along with examples of marking. The authors propose that one method of providing this support and coaching could be by a process of peer review of a selection of papers prior to the main marking. New markers in particular would benefit from further guidance, however they are influenced by others early on in their marking career and course organisers should be mindful of this when arranging double marking

Adolescent Binge Drinking Leads to Changes in Alcohol Drinking, Anxiety, and Amygdalar Corticotropin Releasing Factor Cells in Adulthood in Male Rats

Heavy episodic drinking early in adolescence is associated with increased risk of addiction and other stress-related disorders later in life. This suggests that adolescent alcohol abuse is an early marker of innate vulnerability and/or binge exposure impacts the developing brain to increase vulnerability to these disorders in adulthood. Animal models are ideal for clarifying the relationship between adolescent and adult alcohol abuse, but we show that methods of involuntary alcohol exposure are not effective. We describe an operant model that uses multiple bouts of intermittent access to sweetened alcohol to elicit voluntary binge alcohol drinking early in adolescence (∼postnatal days 28–42) in genetically heterogeneous male Wistar rats. We next examined the effects of adolescent binge drinking on alcohol drinking and anxiety-like behavior in dependent and non-dependent adult rats, and counted corticotropin-releasing factor (CRF) cell in the lateral portion of the central amygdala (CeA), a region that contributes to regulation of anxiety- and alcohol-related behaviors. Adolescent binge drinking did not alter alcohol drinking under baseline drinking conditions in adulthood. However, alcohol-dependent and non-dependent adult rats with a history of adolescent alcohol binge drinking did exhibit increased alcohol drinking when access to alcohol was intermittent. Adult rats that binged alcohol during adolescence exhibited increased exploration on the open arms of the elevated plus maze (possibly indicating either decreased anxiety or increased impulsivity), an effect that was reversed by a history of alcohol dependence during adulthood. Finally, CRF cell counts were reduced in the lateral CeA of rats with adolescent alcohol binge history, suggesting semi-permanent changes in the limbic stress peptide system with this treatment. These data suggest that voluntary binge drinking during early adolescence produces long-lasting neural and behavioral effects with implications for anxiety and alcohol use disorders

D-Cbl Binding to Drk Leads to Dose-Dependent Down-Regulation of EGFR Signaling and Increases Receptor-Ligand Endocytosis

Proper control of Epidermal Growth Factor Receptor (EGFR) signaling is critical for normal development and regulated cell behaviors. Abnormal EGFR signaling is associated with tumorigenic process of various cancers. Complicated feedback networks control EGFR signaling through ligand production, and internalization-mediated destruction of ligand-receptor complexes. Previously, we found that two isoforms of D-Cbl, D-CblS and D-CblL, regulate EGFR signaling through distinct mechanisms. While D-CblL plays a crucial role in dose-dependent down-regulation of EGFR signaling, D-CblS acts in normal restriction of EGFR signaling and does not display dosage effect. Here, we determined the underlying molecular mechanism, and found that Drk facilitates the dose-dependent regulation of EGFR signaling through binding to the proline-rich motif of D-CblL, PR. Furthermore, the RING finger domain of D-CblL is essential for promoting endocytosis of the ligand-receptor complex. Interestingly, a fusion protein of the two essential domains of D-CblL, RING- PR, is sufficient to down-regulate EGFR signal in a dose-dependent manner by promoting internalization of the ligand, Gurken. Besides, RING-SH2Drk, a fusion protein of the RING finger domain of D-Cbl and the SH2 domain of Drk, also effectively down-regulates EGFR signaling in Drosophila follicle cells, and suppresses the effects of constitutively activated EGFR. The RING-SH2Drk suppresses EGFR signaling by promoting the endosomal trafficking of ligand-receptor complexes, suggesting that Drk plays a negative role in EGFR signaling by enhancing receptor endocytosis through cooperating with the RING domain of D-Cbl. Interfering the recruitment of signal transducer, Drk, to the receptor by the RING-SH2Drk might further reduces EGFR signaling. The fusion proteins we developed may provide alternative strategies for therapy of cancers caused by hyper-activation of EGFR signaling

Efficacy of interventions to increase the uptake of chlamydia screening in primary care: a systematic review

<p>Abstract</p> <p>Background</p> <p>As most genital chlamydia infections are asymptomatic, screening is the main way to detect and cases for treatment. We undertook a systematic review of studies assessing the efficacy of interventions for increasing the uptake of chlamydia screening in primary care.</p> <p>Methods</p> <p>We reviewed studies which compared chlamydia screening in the presence and the absence of an intervention. The primary endpoints were screening rate or total tests.</p> <p>Results</p> <p>We identified 16 intervention strategies; 11 were randomised controlled trials and five observational studies, 10 targeted females only, five both males and females, and one males only. Of the 15 interventions among females, six were associated with significant increases in screening rates at the 0.05 level including a multifaceted quality improvement program that involved provision of a urine jar to patients at registration (44% in intervention clinics vs. 16% in the control clinic); linking screening to routine Pap smears (6.9% vs. 4.5%), computer alerts for doctors (12.2% vs. 10.6%); education workshops for clinic staff; internet-based continuing medical education (15.5% vs. 12.4%); and free sexual health consultations (16.8% vs. 13.2%). Of the six interventions targeting males, two found significant increases including the multifaceted quality improvement program in which urine jars were provided to patients at registration (45% vs. 15%); and the offering by doctors of a test to all presenting young male clients, prior to consultation (29 vs. 4%).</p> <p>Conclusions</p> <p>Interventions that promoted the universal offer of a chlamydia test in young people had the greatest impact on increasing screening in primary care.</p

A quantitative analysis of transmission efficiency versus intensity for malaria

The relationship between malaria transmission intensity and efficiency is important for malaria epidemiology, for the design of randomized control trials that measure transmission or incidence as end points, and for measuring and modelling malaria transmission and control. Five kinds of studies published over the past century were assembled and reanalysed to quantify malaria transmission efficiency and describe its relation to transmission intensity, to understand the causes of inefficient transmission and to identify functions suitable for modelling mosquito-borne disease transmission. In this study, we show that these studies trace a strongly nonlinear relationship between malaria transmission intensity and efficiency that is parsimoniously described by a model of heterogeneous biting. When many infectious bites are concentrated on a few people, infections and parasite population structure will be highly aggregated affecting the immunoepidemiology of malaria, the evolutionary ecology of parasite life history traits and the measurement and stratification of transmission for control using entomological and epidemiological data

Neural Stem Cells Achieve and Maintain Pluripotency without Feeder Cells

Background: Differentiated cells can be reprogrammed into pluripotency by transduction of four defined transcription factors. Induced pluripotent stem cells (iPS cells) are expected to be useful for regenerative medicine as well as basic research. Recently, the report showed that mouse embryonic fibroblasts (MEF) cells are not essential for reprogramming. However, in using fibroblasts as donor cells for reprogramming, individual fibroblasts that had failed to reprogram could function as feeder cells. Methodology/Principal Finding: Here, we show that adult mouse neural stem cells (NSCs), which are not functional feeder cells, can be reprogrammed into iPS cells using defined four factors (Oct4, Sox2, Klf4, and c-Myc) under feeder-free conditions. The iPS cells, generated from NSCs expressing the Oct4-GFP reporter gene, could proliferate for more than two months (passage 20). Generated and maintained without feeder cells, these iPS cells expressed pluripotency markers (Oct4 and Nanog), the promoter regions of Oct4 and Nanog were hypomethylated, could differentiated into to all three germ layers in vitro, and formed a germline chimera. These data indicate that NSCs can achieve and maintain pluripotency under feeder-free conditions. Conclusion/Significance: This study suggested that factors secreted by feeder cells are not essential in the initial/early stages of reprogramming and for pluripotency maintenance. This technology might be useful for a human system, as

Seroprevalence and factors associated with herpes simplex virus type 2 among HIV-negative high-risk men who have sex with men from Rio de Janeiro, Brazil: a cross-sectional study

Submitted by Frederico Azevedo ([email protected]) on 2010-11-04T17:19:23Z No. of bitstreams: 1 seroprevalence_and_factors.pdf: 273577 bytes, checksum: 742e51b14ff9ef765bf31b52f3fc8f1a (MD5)Made available in DSpace on 2010-11-04T17:19:23Z (GMT). No. of bitstreams: 1 seroprevalence_and_factors.pdf: 273577 bytes, checksum: 742e51b14ff9ef765bf31b52f3fc8f1a (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Comunicação e Informação Científica e Tecnológica em Saúde. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Background: Herpes simplex virus type 2 (HSV-2) is the leading cause of genital ulcer disease in developing countries, including Brazil, and is especially prevalent among men who have sex with men (MSM). HSV-2 infection represents a risk factor for the acquisition and transmission of other sexually transmitted diseases. The goal of the present cross-sectional study was to estimate HSV- 2 seroprevalence and to determine the factors associated with HSV-2 seropositivity in HIVnegative high-risk MSM from Rio de Janeiro, Brazil. Methods: Stored sera were tested to estimate HSV-2 seroprevalence, while socio-demographic and sexual behavior data were used to measure associations between risk factors and HSV-2 seropositivity. Using the Poisson regression model with robust variance, prevalence ratios (PR) were used to estimate de degree of association between risk factors and HSV-2 seropositivity in bivariate and multivariate analyses. Results: Seroprevalence of HSV-2 was of 45.7% (184 out of 403). Factors independently associated with HSV-2 seroprevalence in the multivariate model were: older age (≥ 26 years, PR: 1.41 95% Confidence Interval: 1.11–1.78), non-white race (PR: 1.32 95%CI: 1.06–1.64), positive serology for syphilis (PR: 1.65 95%CI: 1.33–2.05), positive serology for hepatitis B (PR: 1.25 95%CI: 0.99–1.57), stable male partner in the past 6 months (PR: 1.42 95%CI: 1.12–1.79), and unprotected anal sex with a stable female partner (PR: 1.46 95%CI: 1.05–2.04) in the 6 months preceding the crosssectional assessment. Conclusion: The present study made evident a high prevalence of HSV-2 infection in a sample of HIV-negative high-risk MSM from Rio de Janeiro. This finding indicates the need and urgency for implementing integrated programs for the prevention of HSV-2 and other sexually transmitted diseases, and, in particular, programs targeting high-risk MSM