32 research outputs found
Population Genomic Structure and Recent Evolution of Plasmodium knowlesi, Peninsular Malaysia.
Most malaria in Malaysia is caused by Plasmodium knowlesi parasites through zoonotic infection from macaque reservoir hosts. We obtained genome sequences from 28 clinical infections in Peninsular Malaysia to clarify the emerging parasite population structure and test for evidence of recent adaptation. The parasites all belonged to a major genetic population of P. knowlesi (cluster 3) with high genomewide divergence from populations occurring in Borneo (clusters 1 and 2). We also observed unexpected local genetic subdivision; most parasites belonged to 2 subpopulations sharing a high level of diversity except at particular genomic regions, the largest being a region of chromosome 12, which showed evidence of recent directional selection. Surprisingly, we observed a third subpopulation comprising P. knowlesi infections that were almost identical to each other throughout much of the genome, indicating separately maintained transmission and recent genetic isolation. Each subpopulation could evolve and present a broader health challenge in Asia
Schizont transcriptome variation among clinical isolates and laboratory-adapted clones of the malaria parasite Plasmodium falciparum
Background:
Malaria parasites are genetically polymorphic and phenotypically plastic. In studying transcriptome variation among parasites from different infections, it is challenging to overcome potentially confounding technical and biological variation between samples. We investigate variation in the major human parasite Plasmodium falciparum, generating RNA-seq data on multiple independent replicate sample preparations of merozoite-containing intra-erythrocytic schizonts from a panel of clinical isolates and from long-term laboratory-adapted clones, with a goal of robustly identifying differentially expressed genes.
Results:
Analysis of biological sample replicates shows that increased numbers improve the true discovery rate of differentially expressed genes, and that six independent replicates of each parasite line allowed identification of most differences that could be detected with larger numbers. For highly expressed genes, focusing on the top quartile at schizont stages, there was more power to detect differences. Comparing cultured clinical isolates and laboratory-adapted clones, genes more highly expressed in the laboratory-adapted clones include those encoding an AP2 transcription factor (PF3D7_0420300), a ubiquitin-binding protein and two putative methyl transferases. In contrast, higher expression in clinical isolates was seen for the merozoite surface protein gene dblmsp2, proposed to be a marker of schizonts forming merozoites committed to sexual differentiation. Variable expression was extremely strongly, but not exclusively, associated with genes known to be targeted by Heterochromatin Protein 1. Clinical isolates show variable expression of several known merozoite invasion ligands, as well as other genes for which new RT-qPCR assays validate the quantitation and allow characterisation in samples with more limited material. Expression levels of these genes vary among schizont preparations of different clinical isolates in the first ex vivo cycle in patient erythrocytes, but mean levels are similar to those in continuously cultured clinical isolates.
Conclusions:
Analysis of multiple biological sample replicates greatly improves identification of genes variably expressed between different cultured parasite lines. Clinical isolates recently established in culture show differences from long-term adapted clones in transcript levels of particular genes, and are suitable for analyses requiring biological replicates to understand parasite phenotypes and variable expression likely to be relevant in nature
Highly Variable Expression of Merozoite Surface Protein MSPDBL2 in Diverse Plasmodium falciparum Clinical Isolates and Transcriptome Scans for Correlating Genes.
The merozoite surface protein MSPDBL2 of Plasmodium falciparum is under strong balancing selection and is a target of naturally acquired antibodies. Remarkably, MSPDBL2 is expressed in only a minority of mature schizonts of any cultured parasite line, and mspdbl2 gene transcription increases in response to overexpression of the gametocyte development inducer GDV1, so it is important to understand its natural expression. Here, MSPDBL2 in mature schizonts was analyzed in the first ex vivo culture cycle of 96 clinical isolates from 4 populations with various levels of infection endemicity in different West African countries, by immunofluorescence microscopy with antibodies against a conserved region of the protein. In most isolates, less than 1% of mature schizonts were positive for MSPDBL2, but the frequency distribution was highly skewed, as nine isolates had more than 3% schizonts positive and one had 73% positive. To investigate whether the expression of other gene loci correlated with MSPDBL2 expression, whole-transcriptome sequencing was performed on schizont-enriched material from 17 of the isolates with a wide range of proportions of schizonts positive. Transcripts of particular genes were highly significantly positively correlated with MSPDBL2 positivity in schizonts as well as with mspdbl2 gene transcript levels, showing overrepresentation of genes implicated previously as involved in gametocytogenesis but not including the gametocytogenesis master regulator ap2-g. Single-cell transcriptome analysis of a laboratory-adapted clone showed that most individual parasites expressing mspdbl2 did not express ap2-g, consistent with MSPDBL2 marking a developmental subpopulation that is distinct but likely to co-occur alongside sexual commitment. IMPORTANCE These findings contribute to understanding malaria parasite antigenic and developmental variation, focusing on the merozoite surface protein encoded by the single locus under strongest balancing selection. Analyzing the initial ex vivo generation of parasites grown from a wide sample of clinical infections, we show a unique and highly skewed pattern of natural expression frequencies of MSPDBL2, distinct from that of any other antigen. Bulk transcriptome analysis of a range of clinical isolates showed significant overrepresentation of sexual development genes among those positively correlated with MSPDBL2 protein and mspdbl2 gene expression, indicating the MSPDBL2-positive subpopulation to be often coincident with parasites developing sexually in preparation for transmission. Single-cell transcriptome data confirm the absence of a direct correlation with the ap2-g master regulator of sexual development, indicating that the MSPDBL2-positive subpopulation has a separate function in asexual survival and replication under conditions that promote terminal sexual differentiation
Young pregnant women's views on the acceptability of screening for chlamydia as part of routine antenatal care
<p>Abstract</p> <p>Background</p> <p>In pregnancy, untreated chlamydia infection has been associated with adverse outcomes for both mother and infant. Like most women, pregnant women infected with chlamydia do not report genital symptoms, and are therefore unlikely to be aware of their infection. The aim of this study was to determine the acceptability of screening pregnant women aged 16-25 years for chlamydia as part of routine antenatal care.</p> <p>Methods</p> <p>As part of a larger prospective, cross-sectional study of pregnant women aged 16-25 years attending antenatal services across Melbourne, Australia, 100 women were invited to participate in a face-to-face, semi structured interview on the acceptability of screening for chlamydia during pregnancy. Women infected with chlamydia were oversampled (n = 31).</p> <p>Results</p> <p>Women had low levels of awareness of chlamydia before the test, retained relatively little knowledge after the test and commonly had misconceptions around chlamydia transmission, testing and sequelae. Women indicated a high level of acceptance and support for chlamydia screening, expressing their willingness to undertake whatever care was necessary to ensure the health of their baby. There was a strong preference for urine testing over other methods of specimen collection. Women questioned why testing was not already conducted alongside other antenatal STI screening tests, particularly in view of the risks chlamydia poses to the baby. Women who tested positive for chlamydia had mixed reactions, however, most felt relief and gratitude at having had chlamydia detected and reported high levels of partner support.</p> <p>Conclusions</p> <p>Chlamydia screening as part of routine antenatal care was considered highly acceptable among young pregnant women who recognized the benefits of screening and strongly supported its implementation as part of routine antenatal care. The acceptability of screening is important to the uptake of chlamydia screening in future antenatal screening strategies.</p
Bacterial Vaginosis (BV) Candidate Bacteria: Associations with BV and Behavioural Practices in Sexually-Experienced and Inexperienced Women
BACKGROUND: In recent years several new fastidious bacteria have been identified that display a high specificity for BV; however no previous studies have comprehensively assessed the behavioural risk associations of these bacterial vaginosis-candidate organisms (BV-COs). METHODS: We examined the associations between 8 key previously described BV-COs and BV status established by Nugent's score (NS). We also examined the sexual practices associated with each BV-CO. We incorporated 2 study populations: 193 from a sexually-inexperienced university population and 146 from a highly sexually-active clinic population. Detailed behavioural data was collected by questionnaire and vaginal smears were scored by the Nugent method. Stored samples were tested by quantitative PCR assays for the 8 BV-COs: Atopobium vaginae, Gardnerella vaginalis, Leptotrichia spp., Megasphaera type I, Sneathia spp., and the Clostridia-like bacteria BVAB1, BVAB2 and BVAB3. Associations between BV-COs and BV and behaviours were examined by univariate and multivariable analyses. RESULTS: On univariate analysis, all BV-COs were more common in BV compared to normal flora. However, only Megasphaera type I, BVAB2, A. vaginae and G. vaginalis were significantly independently associated with BV by multivariable analysis. Six of the eight BV-COs (Megasphaera type I, BVAB2, BVAB3, Sneathia, Leptotrichia and G. vaginalis) were rare or absent in sexually-unexposed women, and demonstrated increasing odds of detection with increasing levels of sexual activity and/or numbers of lifetime sexual partners. Only G. vaginalis and A. vaginae were commonly detected in sexually-unexposed women. Megasphaera type I was independently associated with women-who-have-sex-with women (WSW) and lifetime sexual partner numbers, while unprotected penile-vaginal-sex was associated with BVAB2 detection by multivariate analysis. CONCLUSIONS: Four of eight key BV-COs were significantly associated with BV after adjusting for the presence of other BV-COs. The majority of BV-COs were absent or rare in sexually-unexposed women, and associated with increasing sexual exposure, suggesting potential sexual transmission of BV-COs
A global action agenda for turning the tide on fatty liver disease
Background and Aims:
Fatty liver disease is a major public health threat due to its very high prevalence and related morbidity and mortality. Focused and dedicated interventions are urgently needed to target disease prevention, treatment, and care.
Approach and Results:
We developed an aligned, prioritized action agenda for the global fatty liver disease community of practice. Following a Delphi methodology over 2 rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the action priorities using Qualtrics XM, indicating agreement using a 4-point Likert-scale and providing written feedback. Priorities were revised between rounds, and in R2, panelists also ranked the priorities within 6 domains: epidemiology, treatment and care, models of care, education and awareness, patient and community perspectives, and leadership and public health policy. The consensus fatty liver disease action agenda encompasses 29 priorities. In R2, the mean percentage of “agree” responses was 82.4%, with all individual priorities having at least a super-majority of agreement (> 66.7% “agree”). The highest-ranked action priorities included collaboration between liver specialists and primary care doctors on early diagnosis, action to address the needs of people living with multiple morbidities, and the incorporation of fatty liver disease into relevant non-communicable disease strategies and guidance.
Conclusions:
This consensus-driven multidisciplinary fatty liver disease action agenda developed by care providers, clinical researchers, and public health and policy experts provides a path to reduce the prevalence of fatty liver disease and improve health outcomes. To implement this agenda, concerted efforts will be needed at the global, regional, and national levels.publishedVersio
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Selected abstracts from the Breastfeeding and Feminism International Conference 2016
Table of contents A1. Infant feeding and poverty: a public health perspective in a global context Lisa H. Amir A2. Mothers’ experiences with galactagogues for lactation: an exploratory cross sectional study Alessandra Bazzano, Shelley Thibeau, Katherine P. Theall A3. The motherhood journey and breastfeeding: from self-efficacy to resilience and social stigma Anna Blair, Karin Cadwell A4. Breastfeeding as an evolutionary adaptive behavior Emily A. Bronson A5. Conflict-of-interest in public health policy: as real as that logo on your website Elizabeth C. Brooks A6. Co-opting sisterhood and motherhood: behind the scenes of Similac’s aggressive social media campaigns Jodine Chase A7. The exclusion of women from the definition of exclusive breastfeeding Ellen Chetwynd, Rebecca Costello, Kathryn Wouk A8. Healthy maternity policies in the workplace: a state health department’s experience with the “Bring Your Infant to Work” program Lindsey Dermid-Gray A9. Implications for a paradigm shift: factors related to breastfeeding among African American women Stephanie Devane-Johnson, Cheryl Woods Giscombe, Miriam Labbok A10. Social experiences of breastfeeding: building bridges between research and policy: an ESRC-funded seminar series in the UK Sally Dowling A11. Manager’s perspectives of lactation breaks Melanie Fraser A12. The challenging second night: a dialogue from two perspectives Jane Grassley, Deborah McCarter-Spaulding, Becky Spencer A13. The role of lactation consultants in two council breastfeeding services in Melbourne, Australia – some preliminary impressions Jennifer Hocking, Pranee Liamputtong A14. Integrating social marketing and community engagement concepts in community breastfeeding programs Sheree H. Keitt, Harumi Reis-Reilly A15. What happens before and after the maternity stay? Creating a community-wide Ten Steps approach Miriam Labbok A16. #RVABREASTFEEDS: cultivating a breastfeeding-friendly community Leslie Lytle A17. Public health vs. free trade: a longitudinal analysis of a global policy to protect breastfeeding Mary Ann Merz A18. Legislative advocacy and grassroots organizing for improved breastfeeding laws in Virginia Kate Noon A19. Breastfeeding and the rights of incarcerated women Krista M Olson A20. Barriers and support for Puerto Rican breastfeeding working mothers Ana M. Parrilla-Rodríguez, José J. Gorrín-Peralta Melissa Pellicier, Zeleida M. Vázquez-Rivera A21. Pumping at work: a daily struggle for Puerto Rican breastfeeding mothers in spite of the law Melissa Pellicier A22. “I saw a wrong and I wanted to stand up for what I thought was right:” a narrative study on becoming a breastfeeding activist Jennifer L. Pemberton A23. Peer breastfeeding support: advocacy and action Catherine McEvilly Pestl A24. Good intentions: a study of breastfeeding intention and postpartum realities among first-time Central Brooklyn mothers Jennifer Pierre, Philip Noyes, Khushbu Srivastava, Sharon Marshall-Taylor A25. Women describing the infant feeding choice: the impact of the WIC breastfeeding classes on infant feeding practices in Ionia, Michigan Jennifer Proto, Sarah Hyland Laurie Brinks A26. Local and state programs and national partnership to reduce disparities through community breastfeeding support Harumi Reis-Reilly, Martelle Esposito, Megan Phillippi A27. Beyond black breastfeeding week: instagram image content analysis for #blackwomendobreastfeed/#bwdbf Cynthia L. Sears, Delores James, Cedric Harville, Kristina Carswell A28. Stakeholder views of breastfeeding education in the K-12 environment: a review of the literature Nicola Singletary, L. Suzanne Goodell, April Fogleman A29. “The Breastfeeding Transition”: a framework for explaining changes in global breastfeeding rates as related to large-scale forces shaping the status of women Paige Hall Smith A30. Breastfeeding, contraception, and ethics, oh my! Advocacy and informed decision-making in the post-partum period Alison M. Stuebe, Amy G. Bryant, Anne Drapkin Lyerly A31. A hard day’s night: juggling nighttime breastfeeding, sleep, and work Cecilia Tomori A32. Empowering change in Indian country through breastfeeding education Amanda L. Watkins, Joan E. Dodgson A33. Servants and “Little Mothers” take charge: work, class, and breastfeeding rates in the early 20th-century U.S. Jacqueline H. Wol
Sixteen new lung function signals identified through 1000 Genomes Project reference panel imputation
Lung function measures are used in the diagnosis of chronic obstructive pulmonary disease. In 38,199 European ancestry individuals, we studied genome-wide association of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC with 1000 Genomes Project (phase 1)-imputed genotypes and followed up top associations in 54,550 Europeans. We identify 14 novel loci (P <5 x 10(-8)) in or near ENSA, RNU5F-1, KCNS3, AK097794, ASTN2, LHX3, CCDC91, TBX3, TRIP11, RIN3, TEKT5, LTBP4, MN1 and AP1S2, and two novel signals at known loci NPNT and GPR126, providing a basis for new understanding of the genetic determinants of these traits and pulmonary diseases in which they are altered.Peer reviewe