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At least 1,423 records · Page 79Linked to original sources
PubMed2005

Prognostic factors and outcome of human herpesvirus 8-associated primary effusion lymphoma in patients with AIDS.

PURPOSE: Primary effusion lymphoma (PEL) is a rare high-grade B-cell non-Hodgkin's lymphoma associated with Kaposi sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) infection, and is mostly observed in the course of HIV infection. The prognosis is poor, with reported median survival time shorter than 6 months. To date, no prognostic factor has been identified in this subset of lymphoma. PATIENTS AND METHODS: We describe here a large series of HIV-infected patients with PEL, including 28 cases diagnosed in six centers during an 11-year time period. Prognosis analysis was performed using a Cox proportional hazard regression model. Statistically significant covariates were further analyzed in a forward, stepwise multivariate model. RESULTS: After a median follow-up of 3.8 years (range, 10 months to 10.8 years), nine patients (32%) were still alive, and eight of them remained progression free. The median survival was 6.2 months, and the 1-year overall survival rate was 39.3%. Fourteen patients (50%) achieved complete remission, with a 1-year disease-free survival rate at 78.6%. In a multivariate analysis, only a performance status more than 2 (hazard ratio, 5.84; 95% CI, 1.76 to 19.33) and the absence of highly active antiretroviral therapy (HAART) before PEL diagnosis (hazard ratio, 3.26; 95% CI, 1.14 to 9.34) were found to be independent predictors for shorter survival. CONCLUSION: Based on a retrospective series of 28 patients, two prognostic factors were identified as being independently associated with impaired clinical outcome in HIV-related PEL--(1) a poor performance status and (2) the absence of HAART before PEL diagnosis.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Attenuation of mild hyperandrogenic activity in postpubertal acne by a triphasic oral contraceptive containing low doses of ethynyl estradiol and d,l-norgestrel.

The effect of a low dose triphasic oral contraceptive (OC) was evaluated during a 6-month treatment period in 41 patients (mean age, 25.4 +/- 0.7 yr) who had grade I-IV postpubertal acne and normal menses. The OC contained three dose levels of ethynyl estradiol and dl-norgestrel. Acne lesions were assessed, and serum androgen levels were measured during a control cycle and between days 17-21 of treatment cycles 1, 2, 3, and 6. Four patients dropped out after 3 months of treatment. Acne was significantly improved after the first OC cycle. After six cycles, the number of comedones had decreased by 79.6 +/- 3.2% (range, 50-100%) in 69.4% of the patients. Mean baseline levels of testosterone, 17-hydroxyprogesterone, and dehydroepiandrosterone sulfate were in the upper third of the normal range, with elevated individual values in 18.9%, 36.5%, and 26.8% of the women, respectively. Mean baseline levels of androstenedione, free testosterone (T), and 3 alpha-androstanediol glucuronide (3 alpha-diol-G) were above the normal range, with elevated individual values in 51.2%, 75.0%, and 85.4% of the patients, respectively. Sex hormone-binding globulin (SHBG) levels were below the normal range in 26.8% of the cases. At the end of the first OC cycle, there was a significant (P less than 0.01) decrease in all androgen precursors and a 2-fold increase in SHBG. Androstenedione and free T decreased into the normal range during OC intake. Serum 3 alpha-diol-G levels remained elevated, but had decreased by 34.5% at cycle 6 (P less than 0.05). These results show that the triphasic OC has significantly improved acne in postpubertal women for whom acne was the main manifestation of mild hyperandrogenic activity. The improvement in acne corresponded to a decrease in adrenal/ovarian androgens and free T, which led to a decreased metabolism to 3 alpha-diol-G, presumably by the sebaceous glands. The increase in SHBG is considered an estrogenic effect, and the triphasic formulation containing low dose dl-norgestrel is not androgenic but, rather, an estrogen-dominant formulation; as such, this product is recommended in women requiring contraception who also have idiopathic acne.

Acne Vulgaris↗
PubMed2001

Acute exposure to environmental tobacco smoke and heart rate variability.

Environmental tobacco smoke (ETS) has been associated with cardiovascular mortality. Pathophysiologic pathways leading from ETS exposure to cardiopulmonary disease are still being explored. Reduced cardiac autonomic function, as measured by heart rate variability (HRV), has been associated with cardiac vulnerability and may represent an important pathophysiologic mechanism linking ETS and risk of cardiac mortality. In this study we evaluated acute ETS exposure in a commercial airport with changes in HRV in 16 adult nonsmokers. We conducted ambulatory electrocardiographic (ECG) monitoring for 8-hr periods while participants alternated 2 hr in nonsmoking and smoking areas. Nicotine and respirable suspended particle concentrations and participants' blood oxygen saturation were also monitored. We calculated time and frequency domain measures of HRV for periods in and out of the smoking area, and we evaluated associations with ETS using comparative statistics and regression modeling. ETS exposure was negatively associated with all measures of HRV. During exposure periods, we observed an average decrement of approximately 12% in the standard deviation of all normal-to-normal heart beat intervals (an estimate of overall HRV). ETS exposures were not associated with mean heart rate or blood oxygen saturation. Altered cardiac autonomic function, assessed by decrements in HRV, is associated with acute exposure to ETS and may be part of the pathophysiologic mechanisms linking ETS exposure and increased cardiac vulnerability.

Adult↗
PubMed1994

Design and analysis of multilevel analytic studies with applications to a study of air pollution.

We discuss a hybrid epidemiologic design that aims to combine two approaches to studying exposure-disease associations. The analytic approach is based on comparisons between individuals, e.g., case-control and cohort studies, and the ecologic approach is based on comparisons between groups. The analytic approach generally provides a stronger basis for inference, in part because of freedom from between-group confounding and better quality data, but the ecologic approach is less susceptible to attenuation bias from measurement error and may provide greater variability in exposure. The design we propose entails selection of a number of groups and enrollment of individuals within each group. Exposures, outcomes, confounders, and modifiers would be assessed on each individual; but additional exposure data might be available on the groups. The analysis would then combine the individual-level and the group-level comparisons, with appropriate adjustments for exposure measurement errors, and would test for compatibility between the two levels of analysis, e.g., to determine whether the associations at the individual level can account for the differences in disease rates between groups. Trade-offs between numbers of groups, numbers of individuals, and the extent of the individual and group measurement protocols are discussed in terms of design efficiency. These issues are illustrated in the context of an on-going study of the health effects of air pollution in southern California, in which 12 communities with different levels and types of pollution have been selected and 3500 school children are being enrolled in a ten-year cohort study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Studies on the factors affecting the recording of somatosensory evoked potentials induced by tibial nerve stimulation in dogs.

Since spinal cord abnormalities are often associated with lesion in the thoracic or lumber vertebrae, examination of Somatosensory evoked potential (SEP) induced by hind limb nerve stimulation will be useful. In the experiment, scalp recorded SEP in dogs by tibial nerve stimulation was studied on the distribution, the change of latency by body size and the influence of experimental compression to the spinal cord. Greatest response was got at Fz, and shorter latencies for SEP recorded on the ipsilateral stimulation side than from the contralateral side. The equation describing the regression line of the latency with the distance to the recording site from stimulating site was Y = 0.072X+13.23 and the regression was statistically significant. In the experimental study of compression to spinal cord, dorsal compression tended to be sensitive compared to the ventral compression. This study suggested that not only increase of latency but also reduction of amplitude could occur as a result of spinal cord disorders.

Animals↗
PubMed2003

The joint effects of marriage partners' socioeconomic positions on the risk of divorce.

This study investigated the joint effects of spouses' socioeconomic positions on the risk of divorce in Finland. For couples in which both partners were at the lowest educational level, the risk of divorce was lower than could be expected on the basis of the previously documented overall inverse association between each spouse's education and the risk of divorce. Women who were employed or were homemakers, and who had employed husbands, had comparatively stable marriages; couples in which the husband, the wife, or both partners were unemployed had an elevated risk of divorce. A husband's high income decreased the risk of divorce, and a wife's high income increased the risk at all levels of the other spouse's income, but especially when the wife's income exceeded the husband's.

Adolescent↗
PubMed2001

One hundred years of growth: the evolution of height, mass, and body composition in Australian children, 1899-1999.

This paper summarizes 41 reports on the height and mass of Australian children aged between 5.00 and 16.99 years between 1899 and 1999. In all, data on 644,613 children were collated, including individual data on 68,196 children. After primary data treatment to correct for methodological and statistical artifacts, regressions were calculated to quantify the rate of change of height and mass over time. Distributional analysis was used to probe for changes in skewness of mass values, indicative of differentially greater increases at higher percentiles. In addition, studies reporting skin fold measurements were analyzed to assess changes in subcutaneous adiposity since 1976. The results show that height has been increasing at a rate of about 1.02 cm.decade(-1), and mass at a rate of about 0.99 kg.decade(-1). The height and mass of children continue to increase, after a slowing down in the rate of increase between 1950 and 1980. Increases in mass at the higher percentiles have been much greater than at lower percentiles, particularly since the mid-1980s, suggesting that the incidence of obesity is increasing in Australian children. Furthermore, a steady linear increase in subcutaneous skin fold thicknesses since 1976 suggests that the overall level of fatness is increasing in Australian children. These findings indicate that Australian children are following trends becoming evident elsewhere in the developed world, and that we may see an increasingly large subset of increasingly obese children in the early years of the 21st century.

Adolescent↗
PubMed2002

Affinities among Melanesians, Micronesians, and Polynesians: a neutral biparental genetic perspective.

The human colonization of Remote Oceania, the vast Pacific region including Micronesia, Polynesia, and Melanesia beyond the northern Solomon Islands, ranks as one of the greatest achievements of prehistory. Many aspects of human diversity have been examined in an effort to reconstruct this late Holocene expansion. Archaeolinguistic analyses describe a rapid expansion of Austronesian-speaking "Lapita people" from Taiwan out into the Pacific. Analyses of biological markers, however, indicate genetic contributions from Pleistocene-settled Near Oceania into Micronesia and Polynesia, and genetic continuity across Melanesia. Thus, conflicts between archaeolinguistic and biological patterns suggest either linguistic diffusion or gene flow across linguistic barriers throughout Melanesia. To evaluate these hypotheses and the general utility of linguistic patterns for conceptualizing Pacific prehistory, we analyzed 14 neutral, biparental genetic (short tandem repeat) loci from 965 individuals representing 27 island Southeast Asian, Melanesian, Micronesian, and Polynesian populations. Population bottlenecks during the colonization of Remote Oceania are indicated by a statistically significant regression of loss of heterozygosity on migration distance from island Southeast Asia (r = 0.78, p < 0.001). Genetic and geographic distances were consistently correlated (r > 0.35, p < 0.006), indicating extensive gene flow primarily focused among neighboring populations. Significant correlations between linguistic and geographic patterns and between genetic and linguistic patterns depended upon the inclusion of Papuan speakers in the analyses. These results are consistent with an expansion of Austronesian-speaking populations out of island Southeast Asia and into Remote Oceania, followed by substantial gene flow from Near Oceanic populations. Although linguistic and genetic distinctions correspond at times, particularly between Western and Central-Eastern Micronesia, gene flow has reduced the utility of linguistic data within Melanesia. Overall, geographic proximity is a better predictor of biparental genetic relationships than linguistic affinities.

Alleles↗
PubMed2002

Thermodynamic product retrieval methodology and validation for NAST-I.

The National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed (NAST) consists of two passive collocated cross-track scanning instruments, an infrared interferometer (NAST-I) and a microwave radiometer (NAST-M), that fly onboard high-altitude aircraft such as the NASA ER-2 at an altitude near 20 km. NAST-I provides relatively high spectral resolution (0.25-cm(-1)) measurements in the 645-2700-cm(-1) spectral region with moderate spatial resolution (a linear resolution equal to 13% of the aircraft altitude at nadir) cross-track scanning. We report the methodology for retrieval of atmospheric temperature and composition profiles from NAST-I radiance spectra. The profiles were determined by use of a statistical eigenvector regression algorithm and improved, as needed, by use of a nonlinear physical retrieval algorithm. Several field campaigns conducted under varied meteorological conditions have provided the data needed to verify the accuracy of the spectral radiance, the retrieval algorithm, and the scanning capabilities of this instrumentation. Retrieval examples are presented to demonstrate the ability to reveal fine-scale horizontal features with relatively high vertical resolution.

Journal Article↗
PubMed2005

Tropospheric CO observed with the NAST-I retrieval methodology, analyses, and first results.

High-resolution infrared spectra from aircraft and space-based observations contain information about tropospheric carbon monoxide (CO) as well as other trace species. A methodology for retrieving tropospheric CO from such remotely sensed spectral data has been developed for the National Polar-Orbiting Operational Environmental Satellite System's Airborne Sounder Testbed-Interferometer (NAST-I). CO profiles of the troposphere, together with its thermodynamic properties, are determined by use of a three-stage retrieval approach that combines the algorithms of physically based statistical eigenvector regression, simultaneous and iterative matrix inversion, and single-variable error-minimization CO profile matrix inverse retrieval. The NAST-I is collecting data while it is aboard high-altitude aircraft throughout many field campaigns. Detailed retrieval analyses based on the NAST-I instrument system along with retrieval results from several recent field campaigns are presented to demonstrate NAST-I CO retrieval capability.

Journal Article↗
PubMed2005

Maximum entropy deconvolution of infrared spectra: use of a novel entropy expression without sign restriction.

Absorbance and difference infrared spectra are often acquired aiming to characterize protein structure and structural changes of proteins upon ligand binding, as well as for many other chemical and biochemical studies. Their analysis requires as a first step the identification of the component bands (number, position, and area) and as a second step their assignment. The first step of the analysis is challenged by the habitually strong band overlap in infrared spectra. Therefore, it is useful to make use of a mathematical method able to narrow the component bands to the extent to eliminate, or at least reduce, the band overlap. Additionally, to be of general applicability this method should permit negative values for the solution. We present a maximum entropy deconvolution approach for the band-narrowing of absorbance and difference spectra showing the required characteristics, which uses the generalized negative Burg-entropy (Itakura-Saito discrepancy) generalized for difference spectra. We present results on synthetic noisy absorbance and difference spectra, as well as on experimental infrared spectra from the membrane protein bacteriorhodopsin.

Algorithms↗
PubMedDate not supplied

Factors associated with toilet training in the 1990s.

CONTEXT: Few studies have systematically evaluated the factors influencing toilet training in children with normal development. OBJECTIVES: To determine those child, parent, and environmental factors associated with toilet training completion, focusing on the influence of the child's temperament and development. DESIGN AND SETTING: Cross-sectional descriptive study of normal children, ages 15-42 months, attending 1 of 4 pediatric clinics in Milwaukee in 1995 and 1996. METHODS: Demographics for child, parents, and household were surveyed. Temperament was assessed using the Toddler Temperament Scale and the Behavioral Style Questionnaire. Child development was measured using the Bayley Scales of Infant Development II. MAIN OUTCOME MEASURE: Toilet training status was by parental report and was categorized as not trained, not currently training, in training, or training complete. RESULTS: The study population included 496 children, comprising 219 that had not started training, 70 that were not currently training, 148 that were in training, and 59 that were completely trained. The ages at which 50% of the children were predicted to be toilet trained were 35 and 39 months for girls and boys, respectively. In the multivariate regression model, statistically significant factors best predicting toilet training completion were older age, non-Caucasian race, female gender, and single parenthood. Temperament, development, maternal employment, or use of day care were not statistically significant factors. CONCLUSION: Innate factors such as older age, non-Caucasian race, and female gender are the best predictors of completing toilet training (rather than a child's temperament and developmental stage). Day care and maternal employment appear to be unimportant variables. Parents should not be discouraged, because children are completing toilet training at older ages. Research is needed to discover why single parents are more successful at toilet training.

Age Factors↗
PubMedDate not supplied

Compliance with vision-screening guidelines among a national sample of pediatricians.

OBJECTIVE: The American Academy of Pediatrics (AAP) recommends vision screening from birth through adolescence, with visual acuity testing and binocular screening to begin at age 3 years. The 1996 AAP guidelines advised referral for visual acuity worse than 20/40 for children aged 3 to 5 years and worse than 20/30 for children aged 6 years and older. Our objective was to describe vision-screening and referral practices in a national sample of primary care pediatricians. METHODS: We mailed a survey to a random sample of US pediatricians. Initial nonresponders were mailed up to 3 additional surveys. All mailings occurred between May and October 1998. Analyses focused on primary care pediatricians and consisted of descriptive statistics and regression analyses. The main outcome measure was compliance with 1996 AAP recommendations for vision screening. RESULTS: Of the 1491 surveys mailed, 888 (60%) were returned, including 576 (65%) from primary care pediatricians. Vision-screening methods included visual acuity testing (92%), cover test (64%), red reflex test (95%), fundoscopic examinations (65%), and stereopsis testing (32%). Respondents routinely performed visual acuity testing at 3 years (37%), 4 years (79%), 5 years (91%), 6 years (80%), 7-12 years (82%), and 13-18 years (80%). Visual acuity thresholds for referring 3- and 4-year-olds were 20/40 (47%, 51%), 20/50 (36%, 32%), or worse than 20/50 (14%, 12%). The majority of pediatricians referred children aged 5 years and older at 20/40, although thresholds worse than 20/40 were reported commonly (18%-33%). Logistic regressions were done to identify factors associated with higher likelihood of performing specific screening tests. Although no factor was consistently associated with use of all screening tests, size of the practice was significant in several regression models. CONCLUSIONS: Many pediatricians do not follow AAP guidelines for vision screening and referral, especially in younger children. Two thirds of pediatricians do not begin visual acuity testing at age 3 years as recommended, and about one fifth do not test until age 5 years. In addition, one fourth do not perform cover tests or stereopsis testing at any age.

Adolescent↗
PubMed2024

Assessing the causal link between liver function and acute pancreatitis: A Mendelian randomisation study.

A correlation has been reported to exist between exposure factors (e.g. liver function) and acute pancreatitis. However, the specific causal relationship remains unclear. This study aimed to infer the causal relationship between liver function and acute pancreatitis using the Mendelian randomisation method. We employed summary data from a genome-wide association study involving individuals of European ancestry from the UK Biobank and FinnGen. Single-nucleotide polymorphisms (SCNPs), closely associated with liver function, served as instrumental variables. We used five regression models for causality assessment: MR-Egger regression, the random-effect inverse variance weighting method (IVW), the weighted median method (WME), the weighted model, and the simple model. We assessed the heterogeneity of the SNPs using Cochran's Q test. Multi-effect analysis was performed using the intercept term of the MR-Egger method and leave-one-out detection. Odds ratios (ORs) were used to evaluate the causal relationship between liver function and acute pancreatitis risk. A total of 641 SNPs were incorporated as instrumental variables. The MR-IVW method indicated a causal effect of gamma-glutamyltransferase (GGT) on acute pancreatitis (OR = 1.180, 95%CI [confidence interval]: 1.021-1.365, P = 0.025), suggesting that GGT may influence the incidence of acute pancreatitis. Conversely, the results for alkaline phosphatase (ALP) (OR = 0.997, 95%CI: 0.992-1.002, P = 0.197) and aspartate aminotransferase (AST) (OR = 0.939, 95%CI: 0.794-1.111, P = 0.464) did not show a causal effect on acute pancreatitis. Additionally, neither the intercept term nor the zero difference in the MR-Egger regression attained statistical significance (P = 0.257), and there were no observable gene effects. This study suggests that GGT levels are a potential risk factor for acute pancreatitis and may increase the associated risk. In contrast, ALP and AST levels did not affect the risk of acute pancreatitis.

Humans↗
PubMed2004

Chromium, iron, selenium, and zinc levels in serum from preschool children in central Taiwan.

The elemental levels of chromium, iron, selenium, and zinc in the sera from 81 preschool children (3-6 yr old) who lived in central Taiwan were determined. One-half of them, at 12 kindergartens in two metropolitan precincts, lived in the Taichung city (TCPC) and the rest lived in 10 urban townships (TUTPC), which had been randomly selected. A blood sample was collected from each subject; sera were freeze-dried, and chromium, iron, selenium, and zinc were measured using instrumental neutron activation analysis (INAA). Results were considered in relation to environmental conditions and the sex and age of the preschool children. The mean concentrations of zinc serum in the TCPC group were statistically significantly higher than those of TUTPC group (p<0.01). The iron sera from girls are higher than those of boys, in both TCPC and TUTPC groups, and show a statistically significant difference (p<0.05) in the TUTPC group. In the TCPC group, Cr contents were positively correlated with age. Elemental concentrations of sera were compared across ages and country.

Child↗
PubMed2004

Assessing differences in hours worked between male and female dentists: an analysis of cross-sectional national survey data from 1979 through 1999.

BACKGROUND: Women are increasingly entering the dental work force. This study examines the impact of sex, age and other demographic characteristics on dentists' work force participation and on hours worked from 1979 through 1999. METHODS: The study drew on cross-sectional data on dentists (4,209 men and 354 women) from national population surveys conducted by the U.S. Bureau of Labor Statistics from 1979 through 1999. The authors used descriptive statistics and regression analyses to examine sex differences in work force participation and in hours worked across age, as well as other factors. RESULTS: Work force participation was high for both men and women. Men worked more hours and worked part time less frequently; they worked more than 42 hours per week more frequently. Older dentists worked fewer hours, with a larger impact of age seen among men. Having children had a significantly greater effect on the number of hours worked per week among female dentists than among male dentists. CONCLUSIONS: There were significant differences in dentists' hours worked by sex and by age. The consistency of the results with past studies suggests these differences will hold in the near future. PRACTICE IMPLICATIONS: Women's entry into the dental work force has been significant and has helped maintain the supply of dentists. Sex differences in the work force should be considered in evaluating the supply of dentists and related work force policy.

Adult↗
PubMed1975

A method for quantitative detection of tricuspid regurgitation with double injection--single sampling dye-dilution technique.

A method for quantitative detection of tricuspid regurgitation is proposed. In cases without tricuspid insufficiency or intracardiac shunt, 1/slope (ts-fv) of the earpiece dye-dilution curve after injection of dye into the femoreal vein (fv curve) was significantly correlated with that (ts-pa) of the curve after injection into the pulmonary artery (PA curve) within each range of right heart blood volume (rbv) calculated as a product of cardiac output and mean transit time difference between FV curve and PA curve. The relationship among the 3 parameters was expressed as a statistically significant regression equation; log (tsfv) equals 0.9858 log (ts-pa) plus 0.2980 log (RBV) minus 0.6418 (p small than 0.005, sd of predicted ts-fv equals plus or minus 0.591). The assumption was made that tricuspid regurgitation caused prolongation ot ts-fv without any changes in ts-pa or RBV, being based on the concepts of the indicator dispersion and of the path-length distribution. The ratio of tricuspid regurgitation to cardiac output was calculated from (observed ts-fv-predicted ts-fv)/predicted ts-fv, in which predicted ts-fv is the value calculated from ts-pa and RBV using the equation shown above. In 2 patients who manifested clinical tricuspid insufficiency, large amount of tricuspid regurgitant fraction was determined by this method. It is suggested that the present method utilizing double injections--single sampling dye-dilution technique is useful for clinical quantitation of tricuspid regurgitation.

Adolescent↗