183 research outputs found
A Chlamydia trachomatis strain with a chemically generated amino acid substitution (P370L) in the cthtrA gene shows reduced elementary body production Microbial genetics, genomics and proteomics
© 2015 Marsh et al. Background: Chlamydia (C.) trachomatis is the most prevalent bacterial sexually transmitted infection worldwide and the leading cause of preventable blindness. Genetic approaches to investigate C. trachomatis have been only recently developed due to the organism's intracellular developmental cycle. HtrA is a critical stress response serine protease and chaperone for many bacteria and in C. trachomatis has been previously shown to be important for heat stress and the replicative phase of development using a chemical inhibitor of the CtHtrA activity. In this study, chemically-induced SNVs in the cthtrA gene that resulted in amino acid substitutions (A240V, G475E, and P370L) were identified and characterized. Methods: SNVs were initially biochemically characterized in vitro using recombinant protein techniques to confirm a functional impact on proteolysis. The C. trachomatis strains containing the SNVs with marked reductions in proteolysis were investigated in cell culture to identify phenotypes that could be linked to CtHtrA function. Results: The strain harboring the SNV with the most marked impact on proteolysis (cthtrA P370L) was detected to have a significant reduction in the production of infectious elementary bodies. Conclusions: This provides genetic evidence that CtHtrA is critical for the C. trachomatis developmental cycle
A retrospective pilot study to determine whether the reproductive tract microbiota differs between women with a history of infertility and fertile women
© 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists Background: We know very little about the microbiota inhabiting the upper female reproductive tract and how it impacts on fertility. Aims: This pilot study aimed to examine the vaginal, cervical and endometrial microbiota for women with a history of infertility compared to women with a history of fertility. Materials and methods: Using a retrospective case–control study design, women were recruited for collection of vaginal, cervical and endometrial samples. The microbiota composition was analysed by 16S ribosomal RNA (rRNA) gene amplification and endometrial expression of selected human genes by quantitative reverse transcription polymerase chain reaction. Results: Sixty-five specimens from the reproductive tract of 31 women were successfully analysed using 16S rRNA gene amplicon sequencing (16 controls and 15 cases). The dominant microbial community members were consistent in the vagina and cervix, and generally consistent with the endometrium although the relative proportions varied. We detected three major microbiota clusters that did not group by tissue location or case–control status. There was a trend that infertile women more often had Ureaplasma in the vagina and Gardnerella in the cervix. Testing for the expression of selected genes in the endometrium did not show evidence of correlation with case–control status, or with microbial community composition, although Tenascin-C expression correlated with a history of miscarriage. Conclusions: There is a need for further exploration of the endometrial microbiota, and how the microbiota members or profile interplays with fertility or assisted reproductive technologies
Prevalence and duration of non-motor symptoms in prodromal Parkinson's Disease
Background and purpose: The prevalence and duration of non-motor symptoms (NMS) in prodromal Parkinson\u27s disease (PD) has not been extensively studied. The aim of this study was to determine the prevalence and duration of prodromal NMS (pNMS) in a cohort of patients with recently diagnosed PD.
Methods: We evaluated the prevalence and duration of pNMS in patients with early PD (n = 154). NMS were screened for using the Non-Motor Symptom Questionnaire (NMSQuest). We subtracted the duration of the presence of each individual NMS reported from the duration of the earliest motor symptom. NMS whose duration preceded the duration of motor symptoms were considered a pNMS. Individual pNMS were then grouped into relevant pNMS clusters based on the NMSQuest domains. Motor subtypes were defined as tremor dominant, postural instability gait difficulty (PIGD) and indeterminate type according to the Movement Disorder Society Unified Parkinson\u27s Disease Rating Scale revision.
Results: Prodromal NMS were experienced by 90.3% of patients with PD and the median number experienced was 4 (interquartile range, 2-7). A gender difference existed in the pNMS experienced, with males reporting more sexual dysfunction, forgetfulness and dream re-enactment, whereas females reported more unexplained weight change and anxiety. There was a significant association between any prodromal gastrointestinal symptoms [odds ratio (OR), 2.30; 95% confidence interval (CI), 1.08-4.89, P = 0.03] and urinary symptoms (OR, 2.54; 95% CI, 1.19-5.35, P = 0.016) and the PIGD phenotype. Further analysis revealed that total pNMS were not significantly associated with the PIGD phenotype (OR, 1.10; 95% CI, 0.99-1.21, P = 0.068).
Conclusions: Prodromal NMS are common and a gender difference in pNMS experienced in prodromal PD may exist. The PIGD phenotype had a higher prevalence of prodromal gastrointestinal and urinary tract symptoms
Knowledge, attitudes, and preventive practices about colorectal cancer among adults in an area of Southern Italy
<p>Abstract</p> <p>Background</p> <p>Colorectal cancer (CRC) is the second most commonly diagnosed cancer for both sexes in developed countries. This study assessed the knowledge, attitudes, and preventive practices regarding CRC of adults in Italy.</p> <p>Methods</p> <p>A random sample of 1165 adults received a self-administered questionnaire on socio-demographic characteristics; knowledge regarding definition, risk factors, and screening; attitudes regarding perceived risk of contracting CRC and utility of screening tests; health-related behaviors and health care use; source of information.</p> <p>Results</p> <p>Only 18.5% knew the two main modifiable risk factors (low physical activity, high caloric intake from fat) and this knowledge was significantly associated with higher educational level, performing physical activity, modification of dietary habits and physical activity for fear of contracting CRC, and lower risk perception of contracting CRC. Half of respondents identified fecal occult blood testing (FOBT) as main test for CRC prevention and were more knowledgeable those unmarried, more educated, who knew the main risk factors of CRC, and have received advice by physician of performing FOBT. Personal opinion that screening is useful for CRC prevention was high with a mean score of 8.3 and it was predicted by respondents' lower education, beliefs that CRC can be prevented, higher personal perceived risk of contracting CRC, and information received by physician about CRC. An appropriate behavior of performing FOBT if eligible or not performing if not eligible was significantly higher in female, younger, more educated, in those who have been recommended by physician for undergo or not undergo FOBT, and who have not personal history of precancerous lesions and familial history of precancerous lesions or CRC.</p> <p>Conclusion</p> <p>Linkages between health care and educational systems are needed to improve the levels of knowledge and to raise CRC screening adherence.</p
Sensorineural hearing loss after concurrent chemoradiotherapy in nasopharyngeal cancer patients
<p>Abstract</p> <p>Background</p> <p>Sensorineural hearing loss (SNHL) is one of the major long term side effects from radiation therapy (RT) in nasopharyngeal cancer (NPC) patients. This study aims to review the incidences of SNHL when treating with different radiation techniques. The additional objective is to determine the relationship of the SNHL with the radiation doses delivered to the inner ear.</p> <p>Methods</p> <p>A retrospective cohort study of 134 individual ears from 68 NPC patients, treated with conventional RT and IMRT in combination with chemotherapy from 2004-2008 was performed. Dosimetric data of the cochlea were analyzed. Significant SNHL was defined as > 15 dB increase in bone conduction threshold at 4 kHz and PTA (pure tone average of 0.5, 1, 2 kHz). Relative risk (RR) was used to determine the associated factors with the hearing threshold changes at 4 kHz and PTA.</p> <p>Results</p> <p>Median audiological follow up time was 14 months. The incidence of high frequency (4 kHz) SNHL was 44% for the whole group (48.75% in the conventional RT, 37% with IMRT). Internal auditory canal mean dose of > 50 Gy had shown a trend to increase the risk of high frequency SNHL (RR 2.02 with 95% CI 1.01-4.03, p = 0.047).</p> <p>Conclusion</p> <p>IMRT and radiation dose limitation to the inner ear appeared to decrease SNHL.</p
Peritoneal dialysis prescription in children: bedside principles for optimal practice
There is no unique optimal peritoneal dialysis prescription for all children, although the goals of ultrafiltration and blood purification are universal. In turn, a better understanding of the physiology of the peritoneal membrane, as a dynamic dialysis membrane with an exchange surface area recruitment capacity and unique permeability characteristics, results in the transition from an empirical prescription process based on clinical experience alone to the potential for a personalized prescription with individually adapted fill volumes and dwell times. In all cases, the prescribed exchange fill volume should be scaled for body surface area (ml/m2), and volume enhancement should be conducted based on clinical tolerance and intraperitoneal pressure measurements (IPP; cmH2O). The exchange dwell times should be determined individually and adapted to the needs of the patient, with particular attention to phosphate clearance and ultrafiltration capacity. The evolution of residual kidney function and the availability of new, more physiologic, peritoneal dialysis fluids (PDFs) also influence the prescription process. An understanding of all of these principles is integral to the provision of clinically optimal PD
Two-Year Longitudinal Analysis of a Cluster Randomized Trial of Physical Activity Promotion by General Practitioners
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Body fatness during childhood and adolescence and incidence of breast cancer in premenopausal women: a prospective cohort study
INTRODUCTION: Body mass index (BMI) during adulthood is inversely related to the incidence of premenopausal breast cancer, but the role of body fatness earlier in life is less clear. We examined prospectively the relation between body fatness during childhood and adolescence and the incidence of breast cancer in premenopausal women. METHODS: Participants were 109,267 premenopausal women in the Nurses' Health Study II who recalled their body fatness at ages 5, 10 and 20 years using a validated 9-level figure drawing. Over 12 years of follow up, 1318 incident cases of breast cancer were identified. Cox proportional hazards regression was used to compute relative risks (RRs) and 95% confidence intervals (CIs) for body fatness at each age and for average childhood (ages 5–10 years) and adolescent (ages 10–20 years) fatness. RESULTS: Body fatness at each age was inversely associated with premenopausal breast cancer incidence; the multivariate RRs were 0.48 (95% CI 0.35–0.55) and 0.57 (95% CI 0.39–0.83) for the most overweight compared with the most lean in childhood and adolescence, respectively (P for trend < 0.0001). The association for childhood body fatness was only slightly attenuated after adjustment for later BMI, with a multivariate RR of 0.52 (95% CI 0.38–0.71) for the most overweight compared with the most lean (P for trend = 0.001). Adjustment for menstrual cycle characteristics had little impact on the association. CONCLUSION: Greater body fatness during childhood and adolescence is associated with reduced incidence of premenopausal breast cancer, independent of adult BMI and menstrual cycle characteristics
Conducting High-Value Secondary Dataset Analysis: An Introductory Guide and Resources
Secondary analyses of large datasets provide a mechanism for researchers to address high impact questions that would otherwise be prohibitively expensive and time-consuming to study. This paper presents a guide to assist investigators interested in conducting secondary data analysis, including advice on the process of successful secondary data analysis as well as a brief summary of high-value datasets and online resources for researchers, including the SGIM dataset compendium (www.sgim.org/go/datasets). The same basic research principles that apply to primary data analysis apply to secondary data analysis, including the development of a clear and clinically relevant research question, study sample, appropriate measures, and a thoughtful analytic approach. A real-world case description illustrates key steps: (1) define your research topic and question; (2) select a dataset; (3) get to know your dataset; and (4) structure your analysis and presentation of findings in a way that is clinically meaningful. Secondary dataset analysis is a well-established methodology. Secondary analysis is particularly valuable for junior investigators, who have limited time and resources to demonstrate expertise and productivity
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