The Specificity of Secretion through the Alpha and Beta Type II Secretion Systems of Escherichia coli

The Type 2 Secretion System (T2SS) is a molecular apparatus that is found in many Gram negative bacteria. The T2SS system is used for the export of proteins from the cytosol to the extracellular space. A key element in secretion is the assembly of the secretin (GspD), during which monomeric GspD proteins must assemble into a multimeric structure in the outer membrane before secretion can occur. Escherichia coli possesses two different T2SS systems termed the alpha and the beta system. The beta T2SS system is normally active and has been shown to function in the secretion of heat-labile enterotoxin (LT) by Enterotoxigenic (ETEC) E. coli strains. The alpha T2SS system, present in both ETEC and K12 E. coli strains, is silenced during growth under standard laboratory conditions but has been used to study the secretion of LT when the T2SS system is overexpressed from plasmids. The goal of this study was to express the chromosomal copies of the cryptic alpha T2SS system of E. coli and to observe its function in the secretion of LT and Chitinase (ChiA). Mutant strains of E. coli K12 were created in strain BW25113, these mutations consisted of deletions of hns and stpA which are known gspα operon repressors. No expression of the GspDα secretin or secretion of LT or ChiA by the T2SS system were observed in the strains containing deletions in these genes. Additional mutant strains were created in E. coli K12 strain MG1655 in which the natural promoters of the gspα operons were replaced with inducible promoters, the lactosetryptophan fusion promoter (ptac) was used to control the gene expression of the gspABα operon while the arabinose promoter (paraBAD) was used to control the gene expression of the gspC-Oα operon. When the strains created were induced with IPTG and arabinose, expression and assembly of the secretin multimer was observed, but this did not result in the secretion of LT or ChiA. 4 The GspAB complex is required for the assembly of the secretin in Aeromonas hydrophila. The requirements for the GspAB complex in secretin assembly was investigated in E. coli K12 strain MG1655. Mutants were created with a kanamycin (kan) resistance cassette inserted into gspB, while the natural promoters of gspAB and gspC-O were replaced with the inducible promoters ptac and paraBAD, respectively. Induction of these strains showed that GspBα is not required for assembly of the secretin multimer

Racial differences in self‐reported healthcare seeking and treatment for urinary incontinence in community‐dwelling women from the EPI study

Aims Objectives of this study are: (1) to examine the prevalence of healthcare seeking among black and white women with self‐reported urinary incontinence (UI), (2) to investigate barriers to treatment for incontinence, and (3) To investigate commonly used therapeutic modalities for UI. Methods This is a planned secondary analysis of responses from 2,812 black and white community‐dwelling women living in southeastern Michigan, aged 35–64 years, who completed a telephone interview concerning UI, healthcare‐seeking behaviors and management strategies. The study population was 571 subjects (278 black, 293 white) who self‐identified as having urinary incontinence. Results Of these women with UI, 51% sought healthcare with no statistically significant difference between the two races (53% black, 50.6% white, P  = 0.64). In multivariate logistic regression analysis, a higher likelihood of seeking healthcare was associated with increased age, body mass index lower than 30 kg/m 2 , prior surgery for UI, having regular pelvic exams, having a doctor, and worsening severity of UI. There was no significant association between hypothesized barriers to care seeking and race. Almost 95% of the subjects identified lack of knowledge of available treatments as one barrier. Black and white women were similar in percentage use of medications and some self‐care strategies, for example, pad wearing and bathroom mapping, but black women were significantly more likely to restrict fluid intake than white women and marginally less likely to perform Kegels. Conclusions Black and white women seek healthcare for UI at similar, low rates. Improved patient‐doctor relationships and public education may foster healthcare seeking behavior. Neurourol. Urodynam. Neurourol. Urodynam. 30: 1442–1447, 2011. © 2011 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87061/1/21145_ftp.pd

Changes in insulin sensitivity over time and associated factors in HIV-infected adolescents

OBJECTIVE: To compare prevalence of insulin resistance between perinatally HIV-infected (PHIV+) and perinatally HIV-exposed, but uninfected adolescents (PHEU), determine incidence of and contributory factors to new and resolved cases of insulin resistance in PHIV+, and evaluate glucose metabolism. DESIGN: Cross-sectional design for comparison of prevalence among PHIV+ and PHEU. Longitudinal design for incidence and resolution of insulin resistance among PHIV+ at risk for these outcomes. METHODS: The source population was adolescents from pediatric HIV clinics in the United States and Puerto Rico participating in the Pediatric HIV/AIDS Cohort Study, an ongoing prospective cohort study designed to evaluate impact of HIV infection and its treatment on multiple domains in preadolescents and adolescents. Insulin resistance was assessed by homeostatic model assessment of insulin resistance. Those with incident insulin resistance underwent 2-h oral glucose tolerance test and HbA1c. Baseline demographic, metabolic, and HIV-specific variables were evaluated for association with incident or resolved insulin resistance. RESULTS: Unadjusted prevalence of insulin resistance in PHIV+ was 27.3 versus 34.1% in PHEU. After adjustment for Tanner stage, age, sex, and race/ethnicity, there was no significant difference between groups. Factors positively associated with developing insulin resistance included female sex, higher BMI z score, and higher waist circumference; those associated with resolving insulin resistance included male sex and lower BMI z score. CONCLUSION: Prevalence of insulin resistance in PHIV+ and PHEU was substantially higher than that reported in HIV-uninfected nonoverweight youth, but similar to that in HIV-uninfected obese youth. Factors associated with incident or resolved insulin resistance among PHIV+ were similar to those reported in HIV-negative obese youth. However, a contributory role of HIV infection and/or its treatment to the incident risk of insulin resistance cannot be excluded

Returning to an old question: What do television actors do when they act?

This article argues for acknowledging and exploring actors’ processes in critical considerations of television drama. Theatre Studies boasts a tradition of research privileging the actor, including a century’s worth of actor-training manuals, academic works observing rehearsals and performances, and actor accounts. However, such considerations within Television Studies are relatively nascent. Drawing upon continuing drama as a fertile case study for investigating the specificities of television acting, the article concludes that the only way to understand television acting is through the analysis of insights from actors themselves, in combination with the well-established practices of analysing the textual end-products of television acting

Domains of chronic low back pain and assessing treatment effectiveness : a clinical perspective

Nonspecific chronic low back pain (CLBP) is a common clinical condition that has impacts at both the individual and societal level. Pain intensity is a primary outcome used in clinical practice to quantify the severity of CLBP and the efficacy of its treatment; however, pain is a subjective experience that is impacted by a multitude of factors. Moreover, differences in effect sizes for pain intensity are not observed between common conservative treatments, such as spinal manipulative therapy, cognitive behavioral therapy, acupuncture, and exercise training. As pain science evolves, the biopsychosocial model is gaining interest in its application for CLBP management. The aim of this article is to discuss our current scientific understanding of pain and present why additional factors should be considered in conservative CLBP management. In addition to pain intensity, we recommend that clinicians should consider assessing the multidimensional nature of CLBP by including physical (disability, muscular strength and endurance, performance in activities of daily living, and body composition), psychological (kinesiophobia, fear-avoidance, pain catastrophizing, pain self-efficacy, depression, anxiety, and sleep quality), social (social functioning and work absenteeism), and health-related quality-of-life measures, depending on what is deemed relevant for each individual. This review also provides practical recommendations to clinicians for the assessment of outcomes beyond pain intensity, including information on how large a change must be for it to be considered "real" in an individual patient. This information can guide treatment selection when working with an individual with CLBP

International Public Health Research Involving Interpreters: a Case Study from Bangladesh

Background: Cross-cultural and international research are important components of public health research, but the challenges of language barriers and working with interpreters are often overlooked, particularly in the case of qualitative research. Methods: A case-study approach was used to explore experiences of working with an interpreter in Bangladesh as part of a research project investigating women's experiences of emergency obstetric care. The case study: Data from the researcher's field notes provided evidence of experiences in working with an interpreter and show how the model of interviewing was adapted over time to give a more active role to the interpreter. The advantages of a more active role were increased rapport and "flow" in interviews. The disadvantages included reduced control from the researcher's perspective. Some tensions between the researcher and interpreter remained hard to overcome, irrespective of the model used. Independent transcription and translation of the interviews also raised questions around accuracy in translation. Conclusion: The issues examined in this case study have broader implications for public health research. Further work is needed in three areas: 1) developing effective relationships with interpreters; 2) the impact of the interpreter on the research process; and 3) the accuracy of the translation and level of analysis needed in any specific public health research. Finally, this paper highlights the importance to authors of reflecting on the potential impact of translation and interpretation on the research process when disseminating their research

An algorithmic and information-theoretic approach to multimetric index construction

The use of multimetric indices (MMIs), such as the widely used index of biological integrity (IBI), to measure, track, summarize and infer the overall impact of human disturbance on biological communities has been steadily growing in recent years. Initially, MMIs were developed for aquatic communities using preselected biological metrics as indicators of system integrity. As interest in these bioassessment tools has grown, so have the types of biological systems to which they are applied. For many ecosystem types the appropriate biological metrics to use as measures of biological integrity are not known a priori. As a result, a variety of ad hoc protocols for selecting metrics empirically has developed. However, the assumptions made by proposed protocols have not be explicitly described or justified, causing many investigators to call for a clear, repeatable methodology for developing empirically derived metrics and indices that can be applied to any biological system. An issue of particular importance that has not been sufficiently addressed is the way that individual metrics combine to produce an MMI that is a sensitive composite indicator of human disturbance. In this paper, we present and demonstrate an algorithm for constructing MMIs given a set of candidate metrics and a measure of human disturbance. The algorithm uses each metric to inform a candidate MMI, and then uses information-theoretic principles to select MMIs that capture the information in the multidimensional system response from among possible MMIs. Such an approach can be used to create purely empirical (data-based) MMIs or can, optionally, be influenced by expert opinion or biological theory through the use of a weighting vector to create value-weighted MMIs. We demonstrate the algorithm with simulated data to demonstrate the predictive capacity of the final MMIs and with real data from wetlands from Acadia and Rocky Mountain National Parks. For the Acadia wetland data, the algorithm identified 4 metrics that combined to produce a −0.88 correlation with the human disturbance index. When compared to other methods, we find this algorithmic approach resulted in MMIs that were more predictive and comprise fewer metrics

Isospin Breaking and ω\omega->ππ\pi\pi Decay

We study $\omega\to\pi^+\pi^-$ decay up to including all orders of the chiral expansion and one-loop level of mesons in formlism of chiral constituent quark model. This G-parity forbidden decay is caused by $m_u\neq m_d$ and electromagnetic interaction of mesons. We illustrate that in the formlism both nonresonant contact interaction and $\rho$ resonance exchange contribute to this process, and the contribution from $\rho$ resonance exchange is dominant. We obtain that transition matrix element is $=[-(3956\pm 280)-(1697\pm 130)i]$MeV$^2$, and isospin breaking parameter is $m_d-m_u=3.9\pm 0.22$MeV at energy scale $\mu\sim m_\omega$.Comment: Revtex file, 16 pages, four eps figur

Overexpression of human wild-type FUS causes progressive motor neuron degeneration in an age- and dose-dependent fashion

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are relentlessly progressive neurodegenerative disorders with overlapping clinical, genetic and pathological features. Cytoplasmic inclusions of fused in sarcoma (FUS) are the hallmark of several forms of FTLD and ALS patients with mutations in the FUS gene. FUS is a multifunctional, predominantly nuclear, DNA and RNA binding protein. Here, we report that transgenic mice overexpressing wild-type human FUS develop an aggressive phenotype with an early onset tremor followed by progressive hind limb paralysis and death by 12 weeks in homozygous animals. Large motor neurons were lost from the spinal cord accompanied by neurophysiological evidence of denervation and focal muscle atrophy. Surviving motor neurons in the spinal cord had greatly increased cytoplasmic expression of FUS, with globular and skein-like FUS-positive and ubiquitin-negative inclusions associated with astroglial and microglial reactivity. Cytoplasmic FUS inclusions were also detected in the brain of transgenic mice without apparent neuronal loss and little astroglial or microglial activation. Hemizygous FUS overexpressing mice showed no evidence of a motor phenotype or pathology. These findings recapitulate several pathological features seen in human ALS and FTLD patients, and suggest that overexpression of wild-type FUS in vulnerable neurons may be one of the root causes of disease. Furthermore, these mice will provide a new model to study disease mechanism, and test therapies