196 research outputs found
Effects of maternal drinking, smoking, size, and parity on parent-offspring birth weight correlations
Parent-offspring birth weight correlations are presented by sex of parent and infant. They range from .14 to .16, except for the mother-daughter correlation, which is .32. This pattern of parent-offspring correlations varies when the parity of the infant, the size of the mother, and the mother's drinking and smoking status are considered. All parent-offspring correlations are higher when the infant is parity 2 or more. The mother-daughter correlations are significantly higher than mother-son correlations when the mother is above average in usual weight, height, or pregnancy weight gain. When the mother smoked before conception, all birth weight correlations except mother-daughter are essentially zero. The mother-son correlation is also very small if the mother was a regular drinker, independent of her smoking status. The complex relationships in this sample demonstrate that interactions with environmental variables must be taken into account in studies of familial aggregation of human birth weight.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38543/1/1310020206_ftp.pd
Maternal marijuana use during lactation and infant development at one year
Prenatal marijuana exposure is associated with adverse perinatal effects. Very little is known about the effect of postnatal marijuana exposure on infant development. Postnatal exposure can result from maternal use of marijuana during lactation. Delta-9-tetrahydrocannabinol (THC) transfers and concentrates in the mother's milk and is absorbed and metabolized by the nursing infant. The present study investigated the relationship between infant exposure to marijuana via the mother's milk and infant motor and mental development at one year of age. One hundred and thirty-six breast-fed infants were assessed at one year of age for motor and mental development. Sixty-eight infants were exposed to marijuana via the mother's milk. An additional 68 infants were matched to the marijuana-exposed infants on pre- and postpartum maternal alcohol and tobacco use. Marijuana exposure via the mother's milk during the first month postpartum appeared to be associated with a decrease in infant motor development at one year of age.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28699/1/0000519.pd
Chromium Tolerant Microbial Communities from the Chesapeake Bay Watershed
Chromium tolerant bacteria were enumerated from portions of the Chesapeake Bay watershed and examined for their potential to reduce Cr(VI). Water and sediment samples were collected from various locations in Baltimore Harbor and Bear Creek, as well as Sandy Point State Park in Maryland and the Anacostia River in Washington, DC. Samples were spread onto agar plates with CrO42- (5 ppm) as the sole terminal electron acceptor. Plates were incubated anaerobically and colony forming units (CFU) enumerated. CFU arising on minimal-CrO42- medium ranged from 103-104 mL-1 or g-1 and community estimates from sites in proximity to Baltimore City were approximately 6-30X higher than distal sites. Bacterial identification by BIOLOG™ or 16S rRNA sequencing indicated the presence of bacteria of the genera Klebsiella, Pseudomonas, Burkholderia, Kluyvera and others. Typical Cr(VI) reduction rates by these isolates were significantly lower than Shewanella oneidensis, a known metal-reducing bacterium. Results suggested that microbial communities in the Chesapeake Bay watershed, particularly in Baltimore Harbor and Bear Creek, had a high tolerance for Cr(VI) and/or could grow slowly with Cr(VI) as a terminal electron acceptor. However, the isolates did not rapidly degrade Cr(VI) in the laboratory
Erythrocyte acid phosphatase phenotype and gestational length: no relationship in a sample of 3001 births
Erythrocyte acid phosphatase (ACP1) phenotype was examined in 3001 Caucasian infants born at the University of Michigan Women's Hospital. Contrary to reports from other studies, there was no relationship between the ACP1 phenotype and risk of preterm birth in either the total sample or when the sample was subdivided by sex of infant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27696/1/0000082.pd
Alcohol, breastfeeding, and development at 18 months
the ALSPAC Study Team ‡ ABSTRACT. Objective. We aimed to replicate a previous study of 1-year-olds that reported a deficit in motor development associated with moderate alcohol use during lactation, using a different but comparable population. Methodology. The mental development of 915 18-month-old toddlers from a random sample of a longitudinal population-based study in the United Kingdom was measured using the Griffiths Developmental Scales. Frequent self-administered questionnaires during and after pregnancy provided maternal data. The dose of alcohol available to the lactating infant was obtained by multiplying the alcohol intake of the mother by the proportion of breast milk in the infant's diet. We compared this dose with the Griffiths Scales of Mental Development, taking into account potentially confounding variables. Result. Three of the Griffiths scales increased slightly but significantly with increasing infant alcohol exposure; there was no association in the remaining 2 or average of the scales. Discussion. We were unable to replicate the earlier deficit in motor skills associated with lactation alcohol use. One reason may be that the dose of alcohol reaching the lactating infant is small, and tests of infants and toddlers have limited ability to pick up small effects. Studies of older children may resolve the question of the safety of drinking while nursing. Pediatrics 2002;109(5). URL: http://www.pediatrics.org/cgi/content/full/109/5/ e72; alcohol, lactation, child development
Need for timely paediatric HIV treatment within primary health care in rural South Africa
<p>Background: In areas where adult HIV prevalence has reached hyperendemic levels, many infants remain at risk of acquiring HIV infection. Timely access to care and treatment for HIV-infected infants and young children remains an important challenge. We explore the extent to which public sector roll-out has met the estimated need for paediatric treatment in a rural South African setting.</p>
<p>Methods: Local facility and population-based data were used to compare the number of HIV infected children accessing HAART before 2008, with estimates of those in need of treatment from a deterministic modeling approach. The impact of programmatic improvements on estimated numbers of children in need of treatment was assessed in sensitivity analyses.</p>
<p>Findings: In the primary health care programme of HIV treatment 346 children <16 years of age initiated HAART by 2008; 245(70.8%) were aged 10 years or younger, and only 2(<1%) under one year of age. Deterministic modeling predicted 2,561 HIV infected children aged 10 or younger to be alive within the area, of whom at least 521(20.3%) would have required immediate treatment. Were extended PMTCT uptake to reach 100% coverage, the annual number of infected infants could be reduced by 49.2%.</p>
<p>Conclusion: Despite progress in delivering decentralized HIV services to a rural sub-district in South Africa, substantial unmet need for treatment remains. In a local setting, very few children were initiated on treatment under 1 year of age and steps have now been taken to successfully improve early diagnosis and referral of infected infants.</p>
A random cell motility gradient downstream of FGF controls elongation of amniote embryos
Vertebrate embryos are characterized by an elongated antero-posterior (AP) body axis, which forms by progressive cell deposition from a posterior growth zone in the embryo. Here, we used tissue ablation in the chicken embryo to demonstrate that the caudal presomitic mesoderm (PSM) has a key role in axis elongation. Using time-lapse microscopy, we analysed the movements of fluorescently labelled cells in the PSM during embryo elongation, which revealed a clear posterior-to-anterior gradient of cell motility and directionality in the PSM. We tracked the movement of the PSM extracellular matrix in parallel with the labelled cells and subtracted the extracellular matrix movement from the global motion of cells. After subtraction, cell motility remained graded but lacked directionality, indicating that the posterior cell movements associated with axis elongation in the PSM are not intrinsic but reflect tissue deformation. The gradient of cell motion along the PSM parallels the fibroblast growth factor (FGF)/mitogen-activated protein kinase (MAPK) gradient1, which has been implicated in the control of cell motility in this tissue2. Both FGF signalling gain- and loss-of-function experiments lead to disruption of the motility gradient and a slowing down of axis elongation. Furthermore, embryos treated with cell movement inhibitors (blebbistatin or RhoK inhibitor), but not cell cycle inhibitors, show a slower axis elongation rate. We propose that the gradient of random cell motility downstream of FGF signalling in the PSM controls posterior elongation in the amniote embryo. Our data indicate that tissue elongation is an emergent property that arises from the collective regulation of graded, random cell motion rather than by the regulation of directionality of individual cellular movements
Using Smartphones and Machine Learning to Quantify Parkinson Disease Severity:The Mobile Parkinson Disease Score
IMPORTANCE: Current Parkinson disease (PD) measures are subjective, rater-dependent, and assessed in clinic. Smartphones can measure PD features, yet no smartphone-derived rating score exists to assess motor symptom severity in real-world settings. OBJECTIVES: To develop an objective measure of PD severity and test construct validity by evaluating the ability of the measure to capture intraday symptom fluctuations, correlate with current standard PD outcome measures, and respond to dopaminergic therapy. DESIGN, SETTING, AND PARTICIPANTS: This observational study assessed individuals with PD who remotely completed 5 tasks (voice, finger tapping, gait, balance, and reaction time) on the smartphone application. We used a novel machine-learning-based approach to generate a mobile Parkinson disease score (mPDS) that objectively weighs features derived from each smartphone activity (eg, stride length from the gait activity) and is scaled from 0 to 100 (where higher scores indicate greater severity). Individuals with and without PD additionally completed standard in-person assessments of PD with smartphone assessments during a period of 6 months. MAIN OUTCOMES AND MEASURES: Ability of the mPDS to detect intraday symptom fluctuations, the correlation between the mPDS and standard measures, and the ability of the mPDS to respond to dopaminergic medication. RESULTS: The mPDS was derived from 6148 smartphone activity assessments from 129 individuals (mean [SD] age, 58.7 [8.6] years; 56 [43.4%] women). Gait features contributed most to the total mPDS (33.4%). In addition, 23 individuals with PD (mean [SD] age, 64.6 [11.5] years; 11 [48%] women) and 17 without PD (mean [SD] age 54.2 [16.5] years; 12 [71%] women) completed in-clinic assessments. The mPDS detected symptom fluctuations with a mean (SD) intraday change of 13.9 (10.3) points on a scale of 0 to 100. The measure correlated well with the Movement Disorder Society Unified Parkinson Disease's Rating Scale total (r = 0.81; P < .001) and part III only (r = 0.88; P < .001), the Timed Up and Go assessment (r = 0.72; P = .002), and the Hoehn and Yahr stage (r = 0.91; P < .001). The mPDS improved by a mean (SD) of 16.3 (5.6) points in response to dopaminergic therapy. CONCLUSIONS AND RELEVANCE: Using a novel machine-learning approach, we created and demonstrated construct validity of an objective PD severity score derived from smartphone assessments. This score complements standard PD measures by providing frequent, objective, real-world assessments that could enhance clinical care and evaluation of novel therapeutics
Fine-mapping identifies multiple prostate cancer risk loci at 5p15, one of which associates with TERT expression
Associations between single nucleotide polymorphisms (SNPs) at 5p15 and multiple cancer types have been reported. We have previously shown evidence for a strong association between prostate cancer (PrCa) risk and rs2242652 at 5p15, intronic in the telomerase reverse transcriptase (TERT) gene that encodes TERT. To comprehensively evaluate the association between genetic variation across this region and PrCa, we performed a fine-mapping analysis by genotyping 134 SNPs using a custom Illumina iSelect array or Sequenom MassArray iPlex, followed by imputation of 1094 SNPs in 22 301 PrCa cases and 22 320 controls in The PRACTICAL consortium. Multiple stepwise logistic regression analysis identified four signals in the promoter or intronic regions of TERT that independently associated with PrCa risk. Gene expression analysis of normal prostate tissue showed evidence that SNPs within one of these regions also associated with TERT expression, providing a potential mechanism for predisposition to disease
Plantations, outgrowers and commercial farming in Africa: agricultural commercialisation and implications for agrarian change
Whether or not investments in African agriculture can generate quality employment at scale,avoid dispossessing local people of their land,promote diversified and sustainable livelihoods, and catalyse more vibrant local economies depends on what farming model is pursued. In this Forum, we build on recent scholarship by discussing the key findings of our recent studies in Ghana, Kenya and Zambia. We examined cases of three models of agricultural commercialisation, characterised by different sets of institutional arrangements that link land, labour and capital. The three models are: plantations or estates with on-farm processing; contract farming and outgrower schemes; and medium-scale commercial farming areas. Building on core debates in the critical agrarian studies literature, we identify commercial farming areas and contract farming as producing the most local economic linkages, and plantations/estates as producing more jobs, although these are of low quality and mostly casual. We point to the gender and generational dynamics emerging in the three models, which reflect the changing demand for family and wage labour. Models of agricultural commercialisation do not always deliver what is expected of them in part because local conditions play a critical role in the unfolding outcomes for land relations, labour regimes, livelihoods and local economies
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