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PubMed2026

Branching plasticity and candidate gene-hormone networks associated with shade responses in soybean under relay strip intercropping.

BACKGROUND: Branching is a key determinant of high-yield plant architecture in soybean, particularly in maize- soybean relay strip intercropping where plants experience an "initially shaded-then fully illuminated" light regime. However, the genetic regulation of branching responses to shading remains poorly understood. METHODS: We evaluated 11 branching-related traits across 202 soybean accessions grown under monoculture (SS) and relay strip intercropping (RI). Branch number (BN), branching incidence (BI), and total branch length (TBL) were assessed together with stress tolerance indices (STI) and relative distance plasticity index (RDPI). Genome-wide association studies (GWAS) using mixed linear model (MLM) and three-variance-component MLM (3VmrMLM) were combined with haplotype and protein structural analyses to refine candidate genes. RESULTS: Based on Pearson correlation analysis of all 11 traits, BN, BI, and TBL measured before maize harvest showed the strongest and most consistent associations with branch seed weight within the corresponding cropping system (BSW_SS under SS and BSW_RI under RI), whereas other traits showed weaker or environment-dependent associations. Higher STI values calculated from these traits during the co-growth phase were negatively associated with BSW_RI, suggesting weaker compensatory recovery after light restoration in genotypes with more stable early branching patterns between SS and RI. In contrast, mediation analysis indicated that RDPI was positively associated with BSW_RI mainly through improved mature branching architecture (MB_index), which accounted for approximately 70% of the total positive effect. GWAS identified 57 and 74 significant QTNs using MLM and 3VmrMLM, respectively, and LD-window genes were filtered for exonic nonsynonymous or premature stop-codon variants, yielding 883 genes with putative functional variants. Two high-confidence genes emerged: Glyma.02G058600 (PP2C55), exhibiting shading-specific haplotype effects likely linked to GA-mediated branch-stem balance, and Glyma.02G059900 (DA1-related protein), showing stable effects across environments and implicated in ABA-mediated suppression of axillary meristems. CONCLUSIONS: These results provide insight into the genetic and physiological basis of soybean branching responses under relay strip intercropping, clarify that branching plasticity and relative shade tolerance represent distinct response dimensions in this system, and identify putative loci that may be useful for breeding soybean cultivars with improved shade adaptation and yield stability.

Glycine max↗
PubMed2025

VEGFA sex-specific signature is associated to long COVID symptom persistence.

BACKGROUND: Long COVID involves persistent symptoms after COVID-19 recovery, affecting multiple organ systems for months or years. Risk factors include female sex, prior chronic conditions, severe SARS-CoV-2 infection, reinfections, and lack of vaccination. As a major public health concern, ongoing research continues to investigate its causes, mechanisms, and long-term effects. METHODS: Proteomic expression analysis of 171 individuals, in two time points, with confirmed SARS-CoV-2 infection, including 133 long COVID patients from the deeply characterized COVICAT cohort, assessed 1395 protein biomarkers using Olink® technology. Statistical analyses with linear mixed models examined protein expression changes, long COVID status, and sex-specific differences. Functional analysis included gene set enrichment analysis and protein-protein interaction networks. RESULTS: Findings revealed VEGFA overexpression in long COVID patients (effect size 0.322, SE = 0.098, p = 0.0013), along with sex-specific expression patterns and the influence of sex-hormonal status in females, with significant overexpression of circulating VEGFA levels specifically in postmenopausal women (Mann-Whitney U test p value = 8.55 × 10-3). Network analysis identified 109 nodes and 274 edges, with VEGFA ranking highest in centrality. Dysregulated chemokine signaling, complement activation, and viral reactivation were also confirmed, consistent with prior studies. CONCLUSIONS: Using high-throughput proteomic profiling in a population-based cohort, we observed that vascular dysfunction, particularly involving VEGFA, is a key feature of long COVID, especially in milder cases, with significant overexpression of VEGFA in postmenopausal women. Sex-specific proteomic patterns suggest distinct recovery mechanisms, highlighting the need to consider sex, vascular health, and disease severity in the pathogenesis and management of long COVID.

Humans↗
PubMed2006

Does clinic-measured gait speed differ from gait speed measured in the community in people with stroke?

OBJECTIVE: To compare the extent to which gait speed measured in the clinic setting differs from that measured in the community. DESIGN: Participants completed the 10-m walk test at a self-selected speed in a clinic SETTING. Following this they completed a 300-m community-based walking circuit that covered a variety of environmental conditions. Gait velocity was sampled at different points in the circuit. The same circuit and sampling points were used for all participants. Clinic gait velocity was compared to gait velocity measured on five occasions during the community-based circuit. SETTING: Physiotherapy clinic and local shopping mall. PARTICIPANTS: Twenty-eight chronic stroke patients who regularly accessed the community divided into two groups based on their gait velocity in the clinic. MAIN OUTCOME MEASURES: Walking velocity. RESULTS: Spearman rank correlation coefficient indicated that there was a strong correlation between the total time taken to walk the 300-m course and the clinic-based gait velocity (r = -0.88, P < 0.0001). A linear mixed model with repeated measures analysis revealed significant interaction between community measures for group A versus group B (F4,26 = 4.49, P = 0.0068) and significant differences across community conditions (F4,26 = 7.12, P = 0.0005). CONCLUSION: The clinic-based 10-m walk test is able to predict walking velocity in a community setting in chronic stroke patients who score 0.8 m/s or faster. However, for those who score less than 0.8 m/s in the clinic test, gait velocity in the community may be overestimated.

Aged↗
PubMed1998

Age at onset and outcome in schizophrenia are related to the degree of familial loading.

BACKGROUND: Recent research suggests that high familial loading is associated with early onset of schizophrenia. Results concerning outcome have been controversial. METHOD: We assessed the relationship between familial loading, age at onset and outcome in all Finnish patients with schizophrenia born between 1950 and 1969. Patients and their first-degree relatives were identified using nationwide registers. Familial loading scores were calculated for schizophrenia and for combined psychotic disorders, and patients were accordingly classified into three groups: high (n = 761), intermediate (n = 14,247), and low familial loading (n = 725). Linear mixed models and the Cox proportional hazard model were used in the analyses. RESULTS: Onset was earliest, hospitalisation longest and risk of retirement in receipt of a disability pension highest in the group with high familial loading, with opposite extremes found in the group with low familial loading. CONCLUSIONS: High familial loading for schizophrenia is associated with early onset and poor outcome of schizophrenia.

Adult↗
PubMed2004

Using patients as their own controls for cost evaluation of phase I clinical trials.

PURPOSE: Little is known about the cost of phase I trials in cancer patients compared with that of standard treatments, yet the former is often assumed to be greater than the latter. Our objective was to utilize a new approach, using patients as their own controls, to compare in a pilot study the costs of care for patients on phase I trials with those incurred for standard treatment. PATIENTS AND METHODS: We retrospectively assessed the direct medical costs (DMCs) of 59 patients participating in one of two phase I trials (TRIAL) in solid tumors conducted at Memorial Hospital (MH): (1). perillyl alcohol, and (2). flavopiridol with paclitaxel. Paired-control DMCs were those accrued by the same patient while receiving standard chemotherapy regimens just before (PRE; n = 41) or after (POST; n = 29) the trial at MH, averaged per day. RESULTS: For the 41 PRE patients, the median and mean DMCs per day for the clinical trial versus standard treatment were (US dollars) US dollars 123 v US dollars 133 and US dollars 219 v US dollars 267, respectively. For the 29 POST patients, the median and mean DMCs for the clinical trial versus standard treatment were US dollars 157 v US dollars 152 and US dollars 226 v US dollars 226, respectively. Using a linear mixed model, there was no significant difference between TRIAL and standard treatment DMCs (P =.54). CONCLUSION: Using patients as their own controls represents a new, efficient method for evaluating the cost of phase I trials, and it warrants further study. The results of our pilot study do not suggest that phase I trials always cost payers more than standard treatment.

Adult↗
PubMed2006

High protein pre-term infant formula: effect on nutrient balance, metabolic status and growth.

Several lines of evidence suggest that formula with protein content of 3.0 g/100 kcal does not fully meet the protein needs of very-low-birth weight infants. Our purpose was to compare nitrogen balance, metabolic status and growth in infants fed a standard (3.0 g/100 kcal; RegPro) and high (3.6 g/100 kcal; HiPro) protein infant formula. Infants were fed both formulas, each formula for one week in balanced cross-over design. Metabolic status was monitored throughout. Nutrient balance and plasma amino acids were determined at the end of each week. Data were analysed using a linear mixed model. Eighteen infants were studied. Nine infants received the RegPro and nine received HiPro formula first. Nitrogen intake, absorption and retention were greater with the HiPro formula. None of the infants developed uremia or metabolic acidosis but retinol-binding-protein and weight gain were greater with the HiPro formula. Increased protein accretion paralleled by better weight gain without evidence of metabolic stress indicates that a formula with a protein content of 3.6 g/100 kcal better meets protein needs in these rapidly-growing infants. Further studies are needed to determine whether these short-term outcomes will be translated into long-term benefits.

Cross-Over Studies↗
PubMed2006

Religious service attendance and decline in pulmonary function in a high-functioning elderly cohort.

BACKGROUND: Pulmonary function is an important indicator of respiratory and overall health, yet little is known about the psychosocial factors that predict pulmonary function itself. At the same time, religious activity is emerging as a potential health promoting factor, especially among the elderly. Whether there is a connection between religious activity and pulmonary function is unknown. PURPOSE: In this study, we sought to examine the association between religious attendance and rate of decline in pulmonary function. METHODS: The sample consisted of 1,174 healthy elderly persons enrolled in the MacArthur Study of Successful Aging who were followed for an average of 4.6 years. Information on frequency of religious service attendance and peak expiratory flow rate (PEFR) was collected over 3 waves. A linear mixed model with repeated measures was used to compare rate of decline in PEFR between those who attended religious services regularly and those who did not. RESULTS: Regular religious service attendance was associated with a slower pulmonary function decline among men (by 3.71 L/min per year, p = .02) and women (by 3.27 L/min per year, p = .02), compared to those who never attend services. The findings could not be explained by differences in smoking or physical activity. CONCLUSIONS: Overall findings support the hypothesis that religious activity may play a protective role in maintaining pulmonary health among the elderly.

Aged↗
PubMed2024

Epigenome-wide Association Study Shows Differential DNA Methylation of MDC1, KLF9, and CUTA in Autoimmune Thyroid Disease.

CONTEXT: Autoimmune thyroid disease (AITD) includes Graves disease (GD) and Hashimoto disease (HD), which often run in the same family. AITD etiology is incompletely understood: Genetic factors may account for up to 75% of phenotypic variance, whereas epigenetic effects (including DNA methylation [DNAm]) may contribute to the remaining variance (eg, why some individuals develop GD and others HD). OBJECTIVE: This work aimed to identify differentially methylated positions (DMPs) and differentially methylated regions (DMRs) comparing GD to HD. METHODS: Whole-blood DNAm was measured across the genome using the Infinium MethylationEPIC array in 32 Australian patients with GD and 30 with HD (discovery cohort) and 32 Danish patients with GD and 32 with HD (replication cohort). Linear mixed models were used to test for differences in quantile-normalized &#x3b2; values of DNAm between GD and HD and data were later meta-analyzed. Comb-p software was used to identify DMRs. RESULTS: We identified epigenome-wide significant differences (P < 9E-8) and replicated (P < .05) 2 DMPs between GD and HD (cg06315208 within MDC1 and cg00049440 within KLF9). We identified and replicated a DMR within CUTA (5 CpGs at 6p21.32). We also identified 64 DMPs and 137 DMRs in the meta-analysis. CONCLUSION: Our study reveals differences in DNAm between GD and HD, which may help explain why some people develop GD and others HD and provide a link to environmental risk factors. Additional research is needed to advance understanding of the role of DNAm in AITD and investigate its prognostic and therapeutic potential.

Humans↗
PubMed2006

Sex hormone status may modulate rate of expansion of proximal femur diameter in older women alongside other skeletal regulators.

CONTEXT: Little is known of associations between hip geometry and skeletal regulators. This is important because geometry is a determinant of both hip function and resistance to fracture. OBJECTIVE: We aimed to determine the effects of sex hormone status and other candidate regulators on hip geometry and strength. SUBJECTS AND METHODS: A random sample of 351 women aged 67-79 had two to four hip dual-energy x-ray absorptiometry scans performed over 8 yr of follow-up. Hip structural analysis software was used to measure subperiosteal diameter (PD) and the distance from the center of mass to the lateral cortical margin (d-lat) on three 5-mm-thick cross-sectional regions: narrow neck, intertrochanter, and shaft. Section modulus (Z), bone mineral density (grams per centimeter squared), and an index of bone mineral content (cross-sectional area) were calculated as estimators of bone strength. Serum analytes measured at baseline included SHBG, estradiol, PTH, creatinine, albumin, vitamin D metabolites, and glutamate- and gamma-carboxyglutamate-osteocalcin (OC). A linear mixed model was used to model associations with predictor variables, including testing whether the predictors significantly modified the effect of aging. RESULTS: Aging was associated with increasing PD and d-lat, and higher baseline SHBG significantly modified this effect, in the case of PD, increasing the rates of change at the narrow neck region by 19% for SHBG level 2 sd higher than population mean (P = 0.026). Higher baseline creatinine was independently associated with faster increases in PD and d-lat with aging (P < 0.041). Z declined faster with aging if baseline PTH was higher, and higher albumin had a contrary effect. Z was positively associated with free estradiol and inversely associated with SHBG and glutamate-OC. CONCLUSION: These results show large effects of SHBG on the regulation of proximal femur expansion and bending resistance, probably acting as a surrogate for low bioavailable estrogen. Potentially important effects for fracture resistance in old age were also revealed for PTH, markers related to renal function and the nutritional markers albumin and undercarboxylated OC.

Aged↗
PubMed2002

Genetic and environmental factors affect bone density variances of families of men and women with osteoporosis.

Our aim was to assess the relative impacts of genetics and environment in the families of osteoporotic patients and identify the best subgroup of patients to investigate the genes associated with osteoporosis. We recruited 36 men and 47 women with osteoporosis (probands), median age of 52 and 68 yr, and all their siblings (90) and offspring (83). The families were classified as young or old on the basis of the median age of the probands. We measured the bone mineral density at the femoral neck (FN) and lumbar spine (LS) adjusted for age and weight and standardized (Z-score). Physical activity, nutritional calcium, and alcohol and tobacco consumption were investigated. We compared the mean Z-score using linear mixed model and assessed the familial resemblance using intraclass correlation. The mean Z-scores of the families of osteoporotic patients were significantly negative at FN and LS, with no intergeneration or intergender differences. At FN, but not at LS, the mean Z-score was independently lower in the families of male probands (mean +/- SD: -0.57 +/- 0.96, female: -0.18 +/- 0.85, P = 0.012) and in young families (-0.58 +/- 0.94, old families: -0.11 +/- 0.83, P = 0.006). This suggested that the lower Z-score in the families of men with osteoporosis was related to their younger age. There was significant phenotypic resemblance among members in the families. In the families of female probands, the correlation between the probands and her siblings was weak and disappeared after adjustment on environment, and a resemblance appeared within their children (FN: r = 0.61) suggesting that different environment had masked the resemblance in this subgroup. In the families of male probands, a strong resemblance persisted after adjusting for environment, (proband-offspring at FN: r = 0.46 and within offspring at FN: r = 0.66, at LS: r = 0.61). This showed that resemblance was independent of a common measurable environment in these families of men with osteoporosis. In conclusion, mainly young osteoporotic patients, most of whom were male in our study, are affected by the genetic component.

Adult↗
PubMed2005

Generalized atherosclerosis, cognitive decline, and depressive symptoms in old age.

BACKGROUND: Atherosclerosis may be linked to cognitive decline and depression in old age. METHODS: The Leiden 85-Plus Study is a prospective population-based study of 599 subjects from age 85 onward. The generalized atherosclerotic burden was rated by the number of cardiovascular pathologies at baseline, as assessed by history taking from treating physicians and EKG. Cardiovascular pathologies included myocardial infarction, angina pectoris or myocardial ischemia, claudicatio intermittens, and arterial surgery. Global cognitive function (Mini-Mental State Examination), attention (Stroop Test), processing speed (Letter Digit Coding Test), immediate recall memory (Word Learning Test-Immediate Recall), delayed recall memory (Word Learning Test-Delayed Recall), and depressive symptoms (15-item Geriatric Depression Scale) were assessed each year from ages 85 through 90. The prospective associations between both the generalized atherosclerosis rating and stroke with cognitive function and depressive symptoms were analyzed by linear mixed models adjusted for sex and level of education. RESULTS: During follow-up, there was a significant cognitive decline and a significant increase of depressive symptoms. At baseline, a history of stroke was correlated with lower global cognitive function, slower processing speed, impaired immediate and delayed recall memory, and more depressive symptoms. In addition, a higher generalized atherosclerosis rating was correlated with impaired global cognitive function, lower attention, and a slower processing speed at baseline. During follow-up, a higher generalized atherosclerosis rating was associated with an accelerated decline of immediate recall memory and delayed recall memory. In contrast, there was no relation between the generalized atherosclerosis rating and depressive symptoms, either in the cross-sectional analysis or in the prospective analysis. CONCLUSION: In the population at large, generalized atherosclerosis contributes to cognitive decline in old age but not to depression.

Aged, 80 and over↗
PubMed2007

Education and Alzheimer disease without dementia: support for the cognitive reserve hypothesis.

BACKGROUND: Individuals with no cognitive impairment during life but with neuropathologic Alzheimer disease (AD) may represent cases of presymptomatic, or unrecognized early symptomatic, AD. The cognitive reserve hypothesis suggests that at a particular level of AD pathology, highly educated individuals are less likely to manifest clinical symptoms of dementia vs less-educated individuals. OBJECTIVE: To investigate whether education can help explain a clinical diagnosis of no dementia within 1 year of death among individuals with neuropathologic diagnoses of AD. METHODS: Samples of participants (age 65+ years at last clinical assessment) meeting each of three neuropathologic criteria for AD were constructed using data from the National Alzheimer's Coordinating Center Minimum and Neuropathology Data Sets. Generalized linear mixed models (using the logit link function) were used in each sample to examine whether years of education was associated with dementia within 1 year of death, adjusting for other relevant variables. RESULTS: Twelve percent of individuals meeting Khachaturian (122/1,009), 19% meeting low, intermediate, or high likelihood for National Institute on Aging/Reagan Institute (320/1,704), and 14% meeting possible, probable, or definite Consortium to Establish a Registry for Alzheimer's Disease (265/1,835) neuropathologic criteria for AD were nondemented at their final clinical assessment. Persons with more education were less likely to have a dementia diagnosis in each sample. CONCLUSIONS: Regardless of the neuropathologic criteria used, education is predictive of dementia status among individuals with neuropathologic Alzheimer disease. These results support the theory that individuals with greater cognitive reserve, as reflected in years of education, are better able to cope with AD brain pathology without observable deficits in cognition.

Aged↗
PubMed2005

Changes in athlete burnout and motivation over a 12-week league tournament.

INTRODUCTION: To date, empirical reports of an association between motivation and athlete burnout have been exclusively based on cross-sectional research. Conclusions regarding the nature of the relationship between motivation and burnout are limited because they do not provide longitudinal information. PURPOSE: To examine the relationship between burnout and motivation across a 12-wk league tournament (pretournament, midtournament, and end of tournament). METHOD: Data were collected on using the Athlete Burnout Questionnaire and Sport Motivation Scale from 102 adult professional male rugby players at three different times during a 12-wk league tournament. RESULTS: Linear mixed modeling was used to explore hypothesized relationships between individual key characteristics of burnout and factors/covariates across time. Within the models, amotivation, the least self-determined type of motivation, had a large positive association with key characteristics of burnout. Self-determined forms of motivation (i.e., intrinsic motivation) exhibited significant negative associations with burnout. Extrinsic motivation, proposed to exist between intrinsic and amotivation on the self-determination continuum, was negatively associated with sport devaluation and reduced accomplishment as well as positively associated with physical and emotional exhaustion. Other factors related to burnout within the analysis included time (pretournament, in tournament, and end of tournament), team membership, number of injuries, years of national domestic league experience, and win/loss history. CONCLUSIONS: Overall, the results reflect the burnout experience may vary over time and support the potential utility of a self-determination theory explanation of burnout.

Adult↗
PubMed2026

Evaluating a Genome-Wide Polygenic Score for Handgrip Strength and Its Interplay with Leisure-Time Physical Activity Across the IGEMS Twin Cohorts.

PURPOSE: Polygenic scores (PGSs) may help assess genetic predisposition to multifactorial traits. We examined whether age, sex, and leisure-time physical activity (LTPA) modify the association between a PGS for handgrip strength (HGS) and measured HGS in older adults. METHODS: PGS for HGS (PGS hgs) , based on Pan-UK Biobank genome-wide association study data, was calculated for 5103 participants (aged 40-96; 44% women) from eight twin cohorts in Denmark, Sweden, Australia, the United States, and Finland within the IGEMS consortium. Sex-standardized HGS and self-reported LTPA were assessed cross-sectionally. Linear mixed models estimated associations between PGS hgs and HGS, including interactions with age, country, and LTPA, as well as an association between PGS hgs and LTPA. Fixed-effect within-pair models were conducted to assess environmental contributions. RESULTS: Higher PGS hgs was associated with greater HGS (&#x3b2; = 2.14, SE = 0.15, P < 0.001), explaining 4.6% of HGS variance overall, with modest variation across countries. In sex-stratified models, PGS hgs explained 5.2% of the variance in females and 4.3% in males. No statistically significant interaction with age was found. A significant PGS hgs &#xd7; LTPA interaction (&#x3b2; = -0.034, P = 0.013) indicated that the association between LTPA and HGS was more pronounced among individuals with lower PGS hgs . The within-pair models offered limited support for the independent environmental impact of LTPA. CONCLUSIONS: The PGS hgs was associated with measured HGS in the meta-analysis, highlighting the potential of PGSs to capture individual differences in strength-related traits across populations. The association of PGS hgs with HGS was moderated by LTPA, such that the beneficial impact of LTPA on HGS was greater among individuals with a lower genetic propensity for HGS.

Humans↗
PubMed2002

A recursive procedure to compute the gametic relationship matrix and its inverse for marked QTL clusters.

Recently, a variety of mixed linear models have been proposed for marker-assisted prediction of the effects of quantitative trait loci (QTLs) in outbred populations of animals. One of them addresses the effects of a cluster of linked QTLs, or those of a particular chromosomal segment, marked by DNA marker(s) and requires that the inverse of the corresponding gametic relationship matrix whose elements are the conditional expected values of the identity-by-descent (IBD) proportions between gametes for individuals be evaluated. Here, for a model of this type, utilizing the property of the IBD set and using the information on the joint gametogenesis processes at the flanking marker loci, we present a recursive method to systematically calculate the elements of the gametic relationship matrix and its inverse. A numerical example is given to illustrate the proposed computing procedure.

Algorithms↗
PubMed2004

Association of FEV1 in asthmatic children with personal and microenvironmental exposure to airborne particulate matter.

Exposure to particulate matter (PM) air pollution has been shown to exacerbate children's asthma, but the exposure sources and temporal characteristics are still under study. Children's exposure to PM is likely to involve both combustion-related ambient PM and PM related to a child's activity in various indoor and outdoor microenvironments. Among 19 children with asthma, 9-17 years of age, we examined the relationship of temporal changes in percent predicted forced expiratory volume in 1 sec (FEV1) to personal continuous PM exposure and to 24-hr average gravimetric PM mass measured at home and central sites. Subjects were followed for 2 weeks during either the fall of 1999 or the spring of 2000, in a southern California region affected by transported air pollution. FEV(subscript)1(/subscript) was measured by subjects in the morning, afternoon, and evening. Exposure measurements included continuous PM using a passive nephelometer carried by subjects; indoor, outdoor home, and central-site 24-hr gravimetric PM2.5 (PM of aerodynamic diameter < 2.5 microm) and PM10; and central-site hourly PM10, nitrogen dioxide, and ozone. Data were analyzed with linear mixed models controlling for within-subject autocorrelation, FEV1 maneuver time, and exposure period. We found inverse associations of FEV1 with increasing PM exposure during the 24 hr before the FEV1 maneuver and with increasing multiday PM averages. Deficits in percent predicted FEV1 (95% confidence interval) for given PM interquartile ranges measured during the preceding 24-hr were as follows: 128 microg/m3 1-hr maximum personal PM, -6.0% (-10.5 to -1.4); 30 microg/m3 24-hr average personal PM, -5.9% (-10.8 to -1.0); 6.7 microg/m3 indoor home PM2.5, -1.6% (-2.8 to -0.4); 16 microg/m3 indoor home PM10, -2.1% (-3.7 to -0.4); 7.1 microg/m3 outdoor home PM2.5, -1.1% (-2.4 to 0.1); and 7.5 microg/m3 central-site PM2.5, -0.7% (-1.9 to 0.4). Stronger associations were found for multiday moving averages of PM for both personal and stationary-site PM. Stronger associations with personal PM were found in boys allergic to indoor allergens. FEV1 was weakly associated with NO2 but not with O3. Results suggest mixed respiratory effects of PM in asthmatic children from both ambient background exposures and personal exposures in various microenvironments.

Adolescent↗
PubMed2004

Urinary 8-hydroxy-2'-deoxyguanosine as a biomarker of oxidative DNA damage in workers exposed to fine particulates.

Residual oil fly ash (ROFA) is a chemically complex mixture of compounds, including metals that are potentially carcinogenic because of their ability to cause oxidative injury. In this study, we investigated the association between exposure to particulate matter with an aerodynamic mass median diameter <or= 2.5 micro m (PM2.5) and oxidative DNA damage and repair, as indicated by urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations, in a group of boilermakers exposed to ROFA and metal fumes. Twenty workers (50% smokers) were monitored for 5 days during an overhaul of oil-fired boilers. The median occupational PM2.5 8-hr time-weighted average was 0.44 mg/m3 (25th-75th percentile, 0.29-0.76). The mean +/- SE creatinine-adjusted 8-OHdG levels were 13.26 +/- 1.04 micro g/g in urine samples collected pre-workshift and 15.22 +/- 0.99 micro g/g in the post-workshift samples. The urinary 8-OHdG levels were significantly greater in the post-workshift samples than in the pre-workshift samples (p = 0.02), after adjusting for urinary cotinine levels, chronic bronchitis status, and age. Linear mixed models indicated a significant exposure-response association between PM2.5 exposure and urinary 8-OHdG levels (p = 0.03). Each 1-mg/m3 incremental increase in PM2.5 exposure was associated with an increase of 1.67 micro g/g (95% confidence interval, 0.21-3.14) in 8-OHdG levels. PM2.5 vanadium, manganese, nickel, and lead exposures also were positively associated with 8-OHdG levels (p <or= 0.05). This study suggests that a relatively young and healthy cohort of boilermakers may experience an increased risk of developing oxidative DNA injury after exposure to high levels of metal-containing particulate matter.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2006

Low blood lead levels do not appear to be further reduced by dietary supplements.

OBJECTIVE: Our objective was to evaluate the association of dietary intakes of selected micronutrients and blood lead (PbB) concentrations in female adults and in children. DESIGN: With longitudinal monitoring, we measured daily intakes of the micronutrients calcium, magnesium, sodium, potassium, barium, strontium, phosphorus, zinc, iron (limited data), and copper from 6-day duplicate diets (2-13 collections per individual) and PbB concentrations. Participants were three groups of females of child-bearing age (one cohort consisting of 21 pregnant subjects and 15 nonpregnant controls, a second cohort of nine pregnant migrants), and one group of 10 children 6-11 years of age. RESULTS: Mean PbB concentrations were <5 microg/dL. A mixed linear model that included only group and time accounted for 5.9% of the variance of the PbB measurements; neither the effect of time nor the effect of group was significant. The model containing all of the micronutrients (except iron, for which there was a great deal of missing data), along with time and group, accounted for approximately 9.2% of the variance of PbB; this increase was not statistically significant. There was, however, a significant association of PbB with phosphorus, magnesium, and copper when all micronutrients were included in the statistical analysis, perhaps reflecting a synergistic effect. CONCLUSIONS: In contrast to most previous studies, we found no statistically significant relationships between the PbB concentrations and micronutrient intake. In adults and older children with low PbB concentrations and minimal exposure to Pb, micronutrient supplementation is probably unnecessary.

Adult↗