2,357 research outputs found
Feasibility of self-collection of fecal specimens by randomly sampled women for health-related studies of the gut microbiome
BACKGROUND: The field of microbiome research is growing rapidly. We developed a method for self-collection of fecal specimens that can be used in population-based studies of the gut microbiome. We conducted a pilot study to test the feasibility of our methods among a random sample of healthy, postmenopausal women who are members of Kaiser Permanente Colorado (KPCO). We aimed to collect questionnaire data, fecal and urine specimens from 60 women, aged 55–69, who recently had a normal screening mammogram. We designed the study such that all questionnaire data and specimens could be collected at home. RESULTS: We mailed an invitation packet, consent form and opt-out postcard to 300 women, then recruited by telephone women who did not opt-out. Verbally consented women were mailed an enrollment package including a risk factor questionnaire, link to an online diet questionnaire, specimen collection kit, and instructions for collecting stool and urine. Specimens were shipped overnight to the biorepository. Of the 300 women mailed an invitation packet, 58 (19%) returned the opt-out postcard. Up to 3 attempts were made to telephone the remaining women, of whom 130 (43%) could not be contacted, 23 (8%) refused, and 12 (4%) were ineligible. Enrollment packages were mailed to 77 women, of whom 59 returned the risk factor questionnaire and specimens. We found no statistically significant differences between enrolled women and those who refused participation or could not be contacted. CONCLUSIONS: We demonstrated that a representative sample of women can be successfully recruited for a gut microbiome study; however, significant personal contact and carefully timed follow-up from the study personnel are required. The methods employed by our study could successfully be applied to analytic studies of a wide range of clinical conditions that have been postulated to be influenced by the gut microbial population
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Risk Prediction for Breast, Endometrial, and Ovarian Cancer in White Women Aged 50 y or Older: Derivation and Validation from Population-Based Cohort Studies
Background: Breast, endometrial, and ovarian cancers share some hormonal and epidemiologic risk factors. While several models predict absolute risk of breast cancer, there are few models for ovarian cancer in the general population, and none for endometrial cancer. Methods and Findings: Using data on white, non-Hispanic women aged 50+ y from two large population-based cohorts (the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial [PLCO] and the National Institutes of Health–AARP Diet and Health Study [NIH-AARP]), we estimated relative and attributable risks and combined them with age-specific US-population incidence and competing mortality rates. All models included parity. The breast cancer model additionally included estrogen and progestin menopausal hormone therapy (MHT) use, other MHT use, age at first live birth, menopausal status, age at menopause, family history of breast or ovarian cancer, benign breast disease/biopsies, alcohol consumption, and body mass index (BMI); the endometrial model included menopausal status, age at menopause, BMI, smoking, oral contraceptive use, MHT use, and an interaction term between BMI and MHT use; the ovarian model included oral contraceptive use, MHT use, and family history or breast or ovarian cancer. In independent validation data (Nurses' Health Study cohort) the breast and ovarian cancer models were well calibrated; expected to observed cancer ratios were 1.00 (95% confidence interval [CI]: 0.96–1.04) for breast cancer and 1.08 (95% CI: 0.97–1.19) for ovarian cancer. The number of endometrial cancers was significantly overestimated, expected/observed = 1.20 (95% CI: 1.11–1.29). The areas under the receiver operating characteristic curves (AUCs; discriminatory power) were 0.58 (95% CI: 0.57–0.59), 0.59 (95% CI: 0.56–0.63), and 0.68 (95% CI: 0.66–0.70) for the breast, ovarian, and endometrial models, respectively. Conclusions: These models predict absolute risks for breast, endometrial, and ovarian cancers from easily obtainable risk factors and may assist in clinical decision-making. Limitations are the modest discriminatory ability of the breast and ovarian models and that these models may not generalize to women of other races. Please see later in the article for the Editors' Summar
Fecal microbiota diversity in survivors of adolescent/young adult Hodgkin lymphoma: A study of twins
BACKGROUND: Adolescent/young adult Hodgkin lymphoma (AYAHL) survivors report fewer exposures to infections during childhood compared with controls, and they have functional lymphocyte aberrations. The gut microbiota plays a central role in immunity. METHODS: We investigated whether fecal microbial diversity differed between 13 AYAHL survivors and their unaffected co-twin controls. Pyrosequencing of fecal bacterial 16S rRNA amplicons yielded 252 943 edited reads that were assigned to species-level operational taxonomic units (OTUs) and standardised for sequencing depth by random sampling. Microbial diversity was compared within vs between twin pairs and by case–control status. RESULTS: The number of unique OTUs was more similar within twin pairs compared with randomly paired participants (P=0.0004). The AYAHL cases had fewer unique OTUs compared with their co-twin controls (338 vs 369, P=0.015); this difference was not significant (169 vs 183, P=0.10) when restricted to abundant OTUs. CONCLUSION: In this small study, AYAHL survivors appear to have a deficit of rare gut microbes. Further work is needed to determine if reduced microbial diversity is a consequence of the disease, its treatment, or a particularly hygienic environment
Design choices for observational studies of the effect of exposure on disease incidence.
The purpose of this paper is to help readers choose an appropriate observational study design for measuring an association between an exposure and disease incidence. We discuss cohort studies, sub-samples from cohorts (case-cohort and nested case-control designs), and population-based or hospital-based case-control studies. Appropriate study design is the foundation of a scientifically valid observational study. Mistakes in design are often irremediable. Key steps are understanding the scientific aims of the study and what is required to achieve them. Some designs will not yield the information required to realise the aims. The choice of design also depends on the availability of source populations and resources. Choosing an appropriate design requires balancing the pros and cons of various designs in view of study aims and practical constraints. We compare various cohort and case-control designs to estimate the effect of an exposure on disease incidence and mention how certain design features can reduce threats to study validity
Maximising the Potential of Longitudinal Cohorts for Research in Neurodegenerative Diseases: A Community Perspective
Despite a wealth of activity across the globe in the area of longitudinal population cohorts, surprisingly little information is available on the natural biomedical history of a number of age-related neurodegenerative diseases (ND), and the scope for intervention studies based on these cohorts is only just beginning to be explored. The Joint Programming Initiative on Neurodegenerative Disease Research (JPND) recently developed a novel funding mechanism to rapidly mobilise scientists to address these issues from a broad, international community perspective. Ten expert Working Groups, bringing together a diverse range of community members and covering a wide ND landscape (Alzheimer’s, Parkinson’s, frontotemporal degeneration, amyotrophic lateral sclerosis, Lewy-body and vascular dementia) were formed to discuss and propose potential approaches to better exploiting and coordinating cohort studies. The purpose of this work is to highlight the novel funding process along with a broad overview of the guidelines and recommendations generated by the ten groups, which include investigations into multiple methodologies such as cognition/functional assessment, biomarkers and biobanking, imaging, health and social outcomes, and pre-symptomatic ND. All of these were published in reports that are now publicly available online.The EU Joint Programming Initiative on Neurodegenerative Disease Research (JPND) supported the ten Working Groups described in this manuscript with funding from the following: The Canadian Institutes of Health Research (CIHR), French National Research Agency (ANR), German Federal Ministry of Education and Research (BMBF), Innovation Fund Denmark, Italian Ministry of Health (IT-MOH), Luxembourg National Research Fund (FNR), Netherlands Organisation for Health Research and Development (ZonMw), Research Council of Norway, Swedish Research Council for Health, Working Life and Welfare, and UK Medical Research Council (MRC)
Outbreak of Mycobacterium chelonae Infection Associated with Tattoo Ink
Background
In January 2012, on the basis of an initial report from a dermatologist, we began to investigate an outbreak of tattoo-associated Mycobacterium chelonae skin and softtissue infections in Rochester, New York. The main goals were to identify the extent, cause, and form of transmission of the outbreak and to prevent further cases of infection.
Methods
We analyzed data from structured interviews with the patients, histopathological testing of skin-biopsy specimens, acid-fast bacilli smears, and microbial cultures and antimicrobial susceptibility testing. We also performed DNA sequencing, pulsed-field gel electrophoresis (PFGE), cultures of the ink and ingredients used in the preparation and packaging of the ink, assessment of source water and faucets at tattoo parlors, and investigation of the ink manufacturer.
Results
Between October and December 2011, a persistent, raised, erythematous rash in the tattoo area developed in 19 persons (13 men and 6 women) within 3 weeks after they received a tattoo from a single artist who used premixed gray ink; the highest occurrence of tattooing and rash onset was in November (accounting for 15 and 12 patients, respectively). The average age of the patients was 35 years (range, 18 to 48). Skin-biopsy specimens, obtained from 17 patients, showed abnormalities in all 17, with M. chelonae isolated from 14 and confirmed by means of DNA sequencing. PFGE analysis showed indistinguishable patterns in 11 clinical isolates and one of three unopened bottles of premixed ink. Eighteen of the 19 patients were treated with appropriate antibiotics, and their condition improved.
Conclusions
The premixed ink was the common source of infection in this outbreak. These findings led to a recall by the manufacturer
Association of Fecal Microbial Diversity and Taxonomy with Selected Enzymatic Functions
Few microbial functions have been compared to a comprehensive survey of the human fecal microbiome. We evaluated determinants of fecal microbial β-glucuronidase and β-glucosidase activities, focusing especially on associations with microbial alpha and beta diversity and taxonomy. We enrolled 51 healthy volunteers (26 female, mean age 39) who provided questionnaire data and multiple aliquots of a stool, from which proteins were extracted to quantify β-glucuronidase and β-glucosidase activities, and DNA was extracted to amplify and pyrosequence 16S rRNA gene sequences to classify and quantify microbiome diversity and taxonomy. Fecal β-glucuronidase was elevated with weight loss of at least 5 lb. (P = 0.03), whereas β-glucosidase was marginally reduced in the four vegetarians (P = 0.06). Both enzymes were correlated directly with microbiome richness and alpha diversity measures, directly with the abundance of four Firmicutes Clostridia genera, and inversely with the abundance of two other genera (Firmicutes Lactobacillales Streptococcus and Bacteroidetes Rikenellaceae Alistipes) (all P = 0.05–0.0001). Beta diversity reflected the taxonomic associations. These observations suggest that these enzymatic functions are performed by particular taxa and that diversity indices may serve as surrogates of bacterial functions. Independent validation and deeper understanding of these associations are needed, particularly to characterize functions and pathways that may be amenable to manipulation
A Prospective Study of Risk-Reducing Salpingo-oophorectomy and Longitudinal CA-125 Screening among Women at Increased Genetic Risk of Ovarian Cancer: Design and Baseline Characteristics: A Gynecologic Oncology Group Study
Women who are genetically predisposed to ovarian cancer are at very high risk of developing this disease. Although risk-reducing salpingo-oophorectomy (RRSO) and various screening regimens are currently recommended to reduce ovarian cancer risk, the optimal management strategy has not been established nor have multiple additional issues been adequately addressed. We developed a collaboration among the Clinical Genetics Branch (National Cancer Institute’s Intramural Research Program), the Gynecologic Oncology Group (GOG), and the Cancer Genetics Network to address these issues
Tolerability of breast ductal lavage in women from families at high genetic risk of breast cancer
<p>Abstract</p> <p>Background</p> <p>Ductal lavage (DL) has been proposed as a minimally-invasive, well-tolerated tool for obtaining breast epithelial cells for cytological evaluation of breast cancer risk. We report DL tolerability in <it>BRCA1/2 </it>mutation-positive and -negative women from an IRB-approved research study.</p> <p>Methods</p> <p>165 <it>BRCA1/2 </it>mutation-positive, 26 mutation-negative and 3 mutation unknown women underwent mammography, breast MRI and DL. Psychological well-being and perceptions of pain were obtained before and after DL, and compared with pain experienced during other screening procedures.</p> <p>Results</p> <p>The average <b><it>anticipated </it></b>and <b><it>experienced </it></b>discomfort rating for DL, 47 and 48 (0–100), were significantly higher (<it>p </it>< 0.01) than the <b><it>anticipated </it></b>and <b><it>experienced </it></b>discomfort of mammogram (38 and 34), MRI (36 and 25) or nipple aspiration (42 and 27). Women with greater pre-existing emotional distress experienced more DL-related discomfort than they anticipated. Women reporting DL-related pain as worse than expected were nearly three times more likely to refuse subsequent DL than those reporting it as the same or better than expected. Twenty-five percent of participants refused repeat DL at first annual follow-up.</p> <p>Conclusion</p> <p>DL was anticipated to be and experienced as <b>more </b>uncomfortable than other procedures used in breast cancer screening. Higher underlying psychological distress was associated with decreased DL tolerability.</p
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