1,917 research outputs found

    Effects of intra-animal nephron heterogeneity on studies of glomerular dynamics

    Get PDF
    Effects of intra-animal nephron heterogeneity on studies of glomerular dynamics. Quintuplicate determinations of the parameters measured in studies of glomerular dynamics revealed that the intra-animal coefficients of variation for Bowman's space and star vessel pressures, nephron filtration rate, and filtration fractions were 54 to 72% larger than the corresponding interanimal coefficients of variation; those for glomerular capillary pressure were more nearly equal. With a net efferent filtration pressure (ΔPE) of 10.6 ± SEM 1.92mm Hg, the rats were far from filtration pressure equilibrium and the calculated ultrafiltration coefficient (Kf) of 2.1 ± SEM 0.2 nl/min ·2mm Hg was lower than in many other studies. Statistical analysis revealed that the precision of estimates of both the measured and the derived parameters in glomerular dynamic studies is affected appreciably by ignoring the intra-animal effect. The importance of the intra-animal variance in glomerular dynamic studies is greatest when only one or two samples of each measured parameter are obtained in every rat (k = 1 or 2) and least when k is large. Triplicate sampling provides combined SEMS that are not greatly larger than those obtained with k = 5, however, and offers the greatest economy in studies of glomerular dynamics. The number of animals required to provide values with ΔPE and Kf that are within ± 20% of the “true” values is rather large.Effets de l'hétérogénéité néphronique intra-animale sur les études de la dynamique glomérulaire. Des déterminations en quintuple des paramètres mesurés dans les études de la dynamique glomérulaire ont révélé que les coefficients de variation intra-animale pour les pressions dans l'espace de Bowman et les vaisseaux étoilés, le débit de filtration glomérulaire et les fractions de filtration étaient 54 à 74% plus grandes que les coefficients de variation inter-animale correspondants; ceux de la pression capillaire glomérulaire étaient plus proches. Avec une pression de filtration effèrente nette (ΔPE) de 10,6 ± SEM 1,92mm Hg, les rats étaient loin d'une pression de filtration en équilibre, et le coefficient d'ultrafiltration calculé (Kf) de 2,1 ± SEM 0,2 nl/min ·2mm Hg était plus faible que lors de nombreuses autres études. L'analyse statistique a révélé que la précision des paramètres mesurés et déduits des études de la dynamique glomérulaire est affectée de façon appréciable en ignorant l'effet intra-animal. L'importance de la variance intra-animale dans les études de la dynamique glomérulaire est très grande lorsque seulement un ou deux échantillons de chaque paramètre mesuré sont obtenus chez chaque rat (k = 1 ou 2), et moindre lorsque k est élevé. Un échantillon-age triple offre cependant des SEM combinés qui ne sont pas beaucoup plus grands que ceux obtenus pour k = 5, cependant, et offre la plus forte économie lors des mesures de la dynamique glomérulaire. Le nombre d'animaux nécessaires pour obtenir des valeurs avec ΔE et Kf entre ± 20% des valeurs “vraies” est assez grand

    Maternal corticotropin-releasing hormone is associated with LEP DNA methylation at birth and in childhood: an epigenome-wide study in Project Viva

    Get PDF
    BackgroundCorticotropin-releasing hormone (CRH) plays a central role in regulating the secretion of cortisol which controls a wide range of biological processes. Fetuses overexposed to cortisol have increased risks of disease in later life. DNA methylation may be the underlying association between prenatal cortisol exposure and health effects. We investigated associations between maternal CRH levels and epigenome-wide DNA methylation of cord blood in offsprings and evaluated whether these associations persisted into mid-childhood.MethodsWe investigated mother-child pairs enrolled in the prospective Project Viva pre-birth cohort. We measured DNA methylation in 257 umbilical cord blood samples using the HumanMethylation450 Bead Chip. We tested associations of maternal CRH concentration with cord blood cells DNA methylation, adjusting the model for maternal age at enrollment, education, maternal race/ethnicity, maternal smoking status, pre-pregnancy body mass index, parity, gestational age at delivery, child sex, and cell-type composition in cord blood. We further examined the persistence of associations between maternal CRH levels and DNA methylation in children's blood cells collected at mid-childhood (n = 239, age: 6.7-10.3 years) additionally adjusting for the children's age at blood drawn.ResultsMaternal CRH levels are associated with DNA methylation variability in cord blood cells at 96 individual CpG sites (False Discovery Rate <0.05). Among the 96 CpG sites, we identified 3 CpGs located near the LEP gene. Regional analyses confirmed the association between maternal CRH and DNA methylation near LEP. Moreover, higher maternal CRH levels were associated with higher blood-cell DNA methylation of the promoter region of LEP in mid-childhood (P < 0.05, β = 0.64, SE = 0.30).ConclusionIn our cohort, maternal CRH was associated with DNA methylation levels in newborns at multiple loci, notably in the LEP gene promoter. The association between maternal CRH and LEP DNA methylation levels persisted into mid-childhood

    Residential Proximity to Major Roadways at Birth, DNA Methylation at Birth and Midchildhood, and Childhood Cognitive Test Scores: Project Viva(Massachusetts, USA).

    Get PDF
    BackgroundEpigenetic variability is hypothesized as a regulatory pathway through which prenatal exposures may influence child development and health.ObjectiveWe sought to examine the associations of residential proximity to roadways at birth and epigenome-wide DNA methylation. We also assessed associations of differential methylation with child cognitive outcomes.MethodsWe estimated residential proximity to roadways at birth using a geographic information system (GIS) and cord blood methylation using Illumina's HumanMethylation450-array in 482 mother-child pairs in Project Viva. We identified individual CpGs associated with residential-proximity-to-roadways at birth using robust linear regression [[Formula: see text]]. We also estimated association between proximity-to-roadways at birth and methylation of the same sites in blood samples collected at age 7-11 y ([Formula: see text]). We ran the same analyses in the Generation R Study for replication ([Formula: see text]). In Project Viva, we investigated associations of differential methylation at birth with midchildhood cognition using linear regression.ResultsLiving closer to major roadways at birth was associated with higher cord blood (and-more weakly-midchildhood blood) methylation of four sites in LAMB2. For each halving of residential-proximity-to-major-roadways, we observed a 0.82% increase in DNA methylation at cg05654765 [95% confidence interval (CI): (0.54%, 1.10%)], 0.88% at cg14099457 [95% CI: (0.56%, 1.19%)], 0.19% at cg03732535 [95% CI: (0.11%, 0.28)], and 1.08% at cg02954987 [95% CI: (0.65%, 1.51%)]. Higher cord blood methylation of these sites was associated with lower midchildhood nonverbal cognitive scores. Our results did not replicate in the Generation R Study.ConclusionsOur discovery results must be interpreted with caution, given that they were not replicated in a separate cohort. However, living close to major roadways at birth was associated with cord blood methylation of sites in LAMB2-a gene known to be linked to axonal development-in our U.S. cohort. Higher methylation of these sites associated with lower nonverbal cognitive scores at age 7-11 y in the same children. https://doi.org/10.1289/EHP2034

    Association of Vitamin E Intake at Early Childhood with Alanine Aminotransferase Levels at Mid-Childhood

    Get PDF
    The extent to which vitamin E (alpha-tocopherol) intake early in childhood is associated with alanine aminotransferase (ALT) level later in childhood is unknown. The objective of this research is to test the hypothesis that higher alpha-tocopherol intake during early childhood is associated with lower odds of elevated ALT levels during mid-childhood, and to examine how body mass index (BMI) influences these relationships. We studied 528 children in Project Viva. Mothers reported child dietary intake at early childhood visits (median 3.1 years) using a validated food frequency questionnaire. At mid-childhood (median 7.6 years), we collected child blood and anthropometric data. The main outcome was elevated sex-specific mid-childhood ALT level (≥ 22.1 units/liter for females and ≥ 25.8 units/liter for males). In multivariable logistic regression models, we assessed the association of energy-adjusted alpha-tocopherol intake with ALT levels, adjusting for child age, sex, race/ethnicity, diet, and age-adjusted, sex-specific BMIz at mid-childhood. Among children in this study, 48% were female, 63% were non-Hispanic white, 19% were non-Hispanic black, and 4% Hispanic/Latino. Mean alpha-tocopherol intake was 3.7±1.0 mg/day (range 1.4-9.2) at early childhood. At mid-childhood, mean BMIz was 0.41±1.0 units and 22% had an elevated ALT level. In multivariable-adjusted logistic regression models, children with higher early childhood vitamin E intake had lower odds of elevated mid-childhood ALT [adjusted odds ratio (AOR) 0.62 (95% CI: 0.39-0.99)] for quartiles 2-4 compared with the lowest quartile of intake. Findings persisted after accounting for early childhood diet [0.62 (0.36, 1.08)] and were strengthened after additionally accounting for mid-childhood BMIz [0.56 (0.32, 0.99)]. Conclusion: In this cohort, higher early childhood intake of alpha-tocopherol was associated with lower odds of elevated mid-childhood ALT level

    Familial Associations of Adiposity: Findings from a Cross-Sectional Study of 12,181 Parental-Offspring Trios from Belarus

    Get PDF
    It is suggested that maternal adiposity has a stronger association with offspring adiposity than does paternal adiposity. Furthermore, a recent small study reported gender assortment in parental-offspring adiposity associations. We aimed to examine these associations in one of the largest studies to date using data from a low-middle income country that has recently undergone a major political and economic transition.In a cross-sectional study of 12,181 parental-offspring trios from Belarus (mean age (SD) of mothers 31.7 (4.9), fathers 34.1 (5.1) and children 6.6 (0.3) at time of assessment), we found positive graded associations of mother's and father's BMI with offspring adiposity. There was no evidence that these associations differed between mothers and fathers. For example, the odds ratio of offspring overweight or obesity (based on BMI) comparing obese and overweight mothers to normal weight mothers was 2.03 (95%CI 1.77, 2.31) in fully adjusted models; the equivalent result for father's overweight/obesity was 1.81 (1.58, 2.07). Equivalent results for offspring being in the top 10% waist circumference were 1.91 (1.67, 2.18) comparing obese/overweight to normal weight mothers and 1.72 (1.53, 1.95) comparing obese/overweight to normal weight fathers. Similarly, results for offspring being in the top 10% of percent fat mass were 1.58 (1.36, 1.84) and 1.76 (1.49, 2.07), for mother's and father's obese/overweight exposures respectively. There was no strong or consistent evidence of gender assortment--i.e. associations of maternal adiposity exposures with offspring outcomes were similar in magnitude for their daughters compared to equivalent associations in their sons and paternal associations were also similar in sons and daughters.These findings suggest that genetic and/or shared familial environment explain family clustering of adiposity. Interventions aimed at changing overall family lifestyle are likely to be important for population level obesity prevention

    Street-view greenspace exposure and objective sleep characteristics among children

    Get PDF
    Greenspace may benefit sleep by enhancing physical activity, reducing stress or air pollution exposure. Studies on greenspace and children's sleep are limited, and most use satellite-derived measures that do not capture ground-level exposures that may be important for sleep. We examined associations of street view imagery (SVI)-based greenspace with sleep in Project Viva, a Massachusetts pre-birth cohort. We used deep learning algorithms to derive novel metrics of greenspace (e.g., %trees, %grass) from SVI within 250m of participant residential addresses during 2007–2010 (mid-childhood, mean age 7.9 years) and 2012–2016 (early adolescence, 13.2y) (N = 533). In early adolescence, participants completed >5 days of wrist actigraphy. Sleep duration, efficiency, and time awake after sleep onset (WASO) were derived from actigraph data. We used linear regression to examine cross-sectional and prospective associations of mid-childhood and early adolescence greenspace exposure with early adolescence sleep, adjusting for confounders. We compared associations with satellite-based greenspace (Normalized Difference Vegetation Index, NDVI). In unadjusted models, mid-childhood SVI-based total greenspace and %trees (per interquartile range) were associated with longer sleep duration at early adolescence (9.4 min/day; 95%CI:3.2,15.7; 8.1; 95%CI:1.7,14.6 respectively). However, in fully adjusted models, only the association between %grass at mid-childhood and WASO was observed (4.1; 95%CI:0.2,7.9). No associations were observed between greenspace and sleep efficiency, nor in cross-sectional early adolescence models. The association between greenspace and sleep differed by racial and socioeconomic subgroups. For example, among Black participants, higher NDVI was associated with better sleep, in neighborhoods with low socio-economic status (SES), higher %grass was associated with worse sleep, and in neighborhoods with high SES, higher total greenspace and %grass were associated with better sleep time. SVI metrics may have the potential to identify specific features of greenspace that affect sleep

    Characteristics and outcome of patients with newly diagnosed advanced or metastatic lung cancer admitted to intensive care units (ICUs)

    Get PDF
    BACKGROUND: Although patients with advanced or metastatic lung cancer have poor prognosis, admission to the ICU for management of life-threatening complications has increased over the years. Patients with newly diagnosed lung cancer appear as good candidates for ICU admission, but more robust information to assist decisions is lacking. The aim of our study was to evaluate the prognosis of newly diagnosed unresectable lung cancer patients. METHODS: A retrospective multicentric study analyzed the outcome of patients admitted to the ICU with a newly diagnosed lung cancer (diagnosis within the month) between 2010 and 2013. RESULTS: Out of the 100 patients, 30 had small cell lung cancer (SCLC) and 70 had non-small cell lung cancer. (Thirty patients had already been treated with oncologic treatments.) Mechanical ventilation (MV) was performed for 81 patients. Seventeen patients received emergency chemotherapy during their ICU stay. ICU, hospital, 3- and 6-month mortality were, respectively, 47, 60, 67 and 71%. Hospital mortality was 60% when invasive MV was used alone, 71% when MV and vasopressors were needed and 83% when MV, vasopressors and hemodialysis were required. In multivariate analysis, hospital mortality was associated with metastatic disease (OR 4.22 [1.4-12.4]; p = 0.008), need for invasive MV (OR 4.20 [1.11-16.2]; p = 0.030), while chemotherapy in ICU was associated with survival (OR 0.23, [0.07-0.81]; p = 0.020). CONCLUSION: This study shows that ICU management can be appropriate for selected newly diagnosed patients with advanced lung cancer, and chemotherapy might improve outcome for patients with SCLC admitted for cancer-related complications. Nevertheless, tumors' characteristics, numbers and types of organ dysfunction should be taken into account in the decisional process before admitting these patients in ICU.Peer reviewe
    corecore