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PubMed1997

Apoptosis.

LEARNING OBJECTIVES: Reading this article will introduce the reader to the basic concept of physiologic cell death referred to as apoptosis. In addition, the role of apoptosis in immune function as well as its contribution to various clinical disorders will be developed. DATA SOURCE: The author's experience with recently described patients who have a unique autoimmune syndrome associated with a defect in apoptosis. In addition, recent reviews on the subject of apoptosis in health and disease served as informational outlines. STUDY SELECTION: Data source included pertinent reviews and articles meeting the educational objectives and these were critically reviewed. RESULTS: Apoptosis is a critical process in cellular homeostasis that only recently has been appreciated. Its role in both immune development and the control of immune responses as well as in T cell cytotoxic effector function has been established. Information is accumulating that diseases such as cancer can be linked to underlying defects in the apoptosis pathway allowing cells that normally would have been eliminated to live. The role of alterations in apoptosis in other chronic diseases, including autoimmune and neurodegenerative disorders, is beginning to emerge. CONCLUSIONS: Apoptosis plays a central part in normal tissue homeostasis as well as having a role in a variety of clinical diseases that are characterized by either increased or decreased cell survival.

Apoptosis↗
PubMedDate not supplied

Concordance between respondent self-reports and medical records for chronic conditions: experience from the Veterans Health Study.

Researchers have frequently relied on case identification using clinician-based screening as the standard. This study evaluates a self-administered screening questionnaire developed for use in the Veterans Health Study. We compared concordance between elderly patients' reports of selected chronic illnesses and the medical record. The purpose of this study was to determine the feasibility of using a self-report screening questionnaire for case identification in an outcomes study of elderly respondents. Reports of the presence of selected chronic illnesses were compared in a sample of patients (N=402) receiving outpatient care between 2 data sources, patient self-report and medical record, to determine overall concordance in 5 common chronic conditions (hypertension, adult-onset diabetes mellitus, chronic low-back pain, osteoarthritis of the knee, and chronic lung disease). Discordance between the 2 data sources varied by condition. Differences in reporting were small for diabetes and hypertension, intermediate for chronic lung disease, and larger for osteoarthritis of the knee and chronic low-back pain, where the chart did not identify substantial proportions of cases reported in the questionnaire. Use of patient-reported screening questionnaires, which are self-administered, is a valid, cost-efficient method to identify some chronic illnesses. Using medical records alone may result in underestimation of some symptom-based conditions.

Adult↗
PubMed2005

Toward a predictive model of patient satisfaction with nurse practitioner care.

PURPOSE: (a) To determine if caring behaviors of nurse practitioners (NPs), gender of NPs, setting (urban or rural), and age, gender, ethnicity, education, and income of patients were predictors of patient satisfaction; (b) to determine which of these characteristics was the best predictor(s) of patient satisfaction; and (c) begin to develop a conceptual model for explaining patient satisfaction with NP care. DATA SOURCES: Responses to the Caring Behaviors Inventory (CBI) and a demographic inquiry by 348 NPs in Louisiana and completion of the Di'Tomasso-Willard Patient Satisfaction Questionnaire (DWPSQ) and a demographic inquiry from 817 patients in Louisiana served as data sources. A predictive modeling design explored which variable(s) is the best predictor of patient satisfaction, and multiple regression was used to determine the equation for the best-fitting line and the optimal model for the best predictor(s) of patient satisfaction. CONCLUSIONS: CBI mean scores were high for all NPs. No statistically significant difference was found between male NPs' and female NPs' total mean CBI scores and between urban or rural total mean CBI scores. DWPSQ mean scores and subscale scores indicated high satisfaction with NP care. No statistically significant relationships were found between the NPs' CBI mean scores and the patients' DWPSQ mean scores. There were significant relationships between the DWPSQ subscales, including Wait Time and Patient Management. Stepwise linear regression revealed that patients' age group was a predictor of DWPSQ total mean scores. IMPLICATIONS FOR PRACTICE: NPs need to be aware of developmental differences in all age groups and the differences in perceptions of care. There are many variables to consider when determining patient satisfaction with care, including the patients' sociodemographic and health variables, the healthcare system, and characteristics of the healthcare providers. Awareness of these variables may affect how NPs deliver care and ensure quality care with which the patients are satisfied.

Adolescent↗
PubMed2006

A regression-based K nearest neighbor algorithm for gene function prediction from heterogeneous data.

BACKGROUND: As a variety of functional genomic and proteomic techniques become available, there is an increasing need for functional analysis methodologies that integrate heterogeneous data sources. METHODS: In this paper, we address this issue by proposing a general framework for gene function prediction based on the k-nearest-neighbor (KNN) algorithm. The choice of KNN is motivated by its simplicity, flexibility to incorporate different data types and adaptability to irregular feature spaces. A weakness of traditional KNN methods, especially when handling heterogeneous data, is that performance is subject to the often ad hoc choice of similarity metric. To address this weakness, we apply regression methods to infer a similarity metric as a weighted combination of a set of base similarity measures, which helps to locate the neighbors that are most likely to be in the same class as the target gene. We also suggest a novel voting scheme to generate confidence scores that estimate the accuracy of predictions. The method gracefully extends to multi-way classification problems. RESULTS: We apply this technique to gene function prediction according to three well-known Escherichia coli classification schemes suggested by biologists, using information derived from microarray and genome sequencing data. We demonstrate that our algorithm dramatically outperforms the naive KNN methods and is competitive with support vector machine (SVM) algorithms for integrating heterogenous data. We also show that by combining different data sources, prediction accuracy can improve significantly CONCLUSION: Our extension of KNN with automatic feature weighting, multi-class prediction, and probabilistic inference, enhance prediction accuracy significantly while remaining efficient, intuitive and flexible. This general framework can also be applied to similar classification problems involving heterogeneous datasets.

Algorithms↗
PubMed1991

Temporal changes in the occurrence of hemorrhoids in the United States and England.

Although numerous etiologic risk factors have been proposed, the pathogenesis of hemorrhoids remains unknown. The present investigation assesses the temporal distribution of hemorrhoids as depicted by physician visits, hospital discharges, and surgical procedures to provide further insight into potential etiologic risk factors. The analysis was based on five data sources: from the United States, the National Disease and Therapeutic Index (NDTI), the National Hospital Discharge Survey (NHDS), and the Commission on Professional Hospital Activities (CPHA); from England and Wales, the Morbidity Statistics from General Practice (MSGP) and the Hospital In-patient Enquiry (HIPE). Results demonstrated a consistent decline in all data sources from the United States. The decrease occurred in males and females similarly and was most striking in those aged 45-64 years. Physician visits and hospital discharges for hemorrhoids in England and Wales likewise declined although the decrease was not as dramatic. The consistency of the temporal distributions among the two countries, as well as among the different sources, suggests that the observed decline may, in fact, reflect an overall decrease in the occurrence of hemorrhoidal disease.

Adolescent↗
PubMed1984

Measurement and replication: evaluating the consistency of eight U. S. fertility surveys.

This paper addresses the comparability of data from eight national fertility surveys conducted in the United States between 1955 and 1980. We examine the extent to which substantive conclusions about the levels and correlates of the timing of first birth vary across these data sources by comparing samples of women who were eligible to be included in more than one study. Results obtained from Ordinary Least Squares (OLS) and logistic regression analyses of several measures of timing indicate few study effects. Thus findings based on data from one survey can be replicated with comparable data from another. One notable exception is the relationship between contraceptive use prior to the first birth and the timing of that birth. The contraceptive variable appears to be poorly measured, leading to unstable estimates of the relationship. In general, our results suggest: (1) the feasibility of pooling data from the various surveys when modeling delayed childbearing; and (2) reasonable accuracy in assessing trends in the timing of first birth from multiple data sources.

Adolescent↗
PubMedDate not supplied

Potential nontraditional applications of statins.

OBJECTIVE: To review the current evidence for use of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) in nontraditional lipid-related applications, including acute coronary syndromes, peripheral arterial disease, stroke, and renal disease, and to describe ongoing trials evaluating the role of statins in these conditions. DATA SOURCES: Clinical literature was identified by a MEDLINE search (1990-November 2002) using >/=1 of the following search terms: acute coronary syndrome(s), angina pectoris, atherosclerosis, atorvastatin, clinical trials, diabetes mellitus, end-stage renal disease, fluvastatin, lovastatin, myocardial infarction, peripheral arterial disease, pravastatin, simvastatin, statins, and stroke. Treatment guidelines issued by professional and governmental organizations, such as the American Diabetes Association, American Heart Association, National Cholesterol Education Program, National Kidney Foundation, and National Stroke Foundation, were reviewed. STUDY SELECTION AND DATA EXTRACTION: Articles identified from the data sources were included if they pertained to the conditions described in the objectives and provided unique information concerning use of statins. DATA SYNTHESIS: Substantial evidence exists for the use of statins in acute coronary syndromes. Meta-analyses of data from major clinical trials indicate that statins prevent first and recurrent stroke, and large-scale trials are underway to evaluate the efficacy of statins in this setting. Accumulating evidence suggests that statins may be beneficial in reducing the morbidity and mortality associated with peripheral arterial disease and end-stage renal disease, and results from ongoing trials may confirm these benefits. Statins may also have a future role in amelioration of other conditions associated with atherosclerosis, such as diabetes mellitus. CONCLUSIONS: A large body of evidence supports the evaluation of statins in clinical settings beyond primary and secondary prevention of morbidity and mortality associated with coronary atherosclerosis.

Arterial Occlusive Diseases↗
PubMed2002

Physician gender effects in medical communication: a meta-analytic review.

CONTEXT: Physician gender has been viewed as a possible source of variation in the interpersonal aspects of medical practice, with speculation that female physicians facilitate more open and equal exchange and a different therapeutic milieu from that of male physicians. However, studies in this area are generally based on small samples, with conflicting results. OBJECTIVE: To systematically review and quantify the effect of physician gender on communication during medical visits. DATA SOURCES: Online database searches of English-language abstracts for the years 1967 to 2001 (MEDLINE, AIDSLINE, PsycINFO, and Bioethics); a hand search was conducted of reprint files and the reference sections of review articles and other publications. STUDY SELECTION: Studies using a communication data source, such as audiotape, videotape, or direct observation, and large national or regional studies in which physician report was used to establish length of visit, were identified through bibliographic and computerized searches. Twenty-three observational studies and 3 large physician-report studies reported in 29 publications met inclusion criteria and were rated. DATA EXTRACTION: The Cohen d was computed based on 2 reviewers' (J.A.H. and Y.A.) independent extraction of quantitative information from the publications. Study heterogeneity was tested using Q statistics and pooled effect sizes were computed using the appropriate effects model. The characteristics of the study populations were also extracted. DATA SYNTHESIS: Female physicians engage in significantly more active partnership behaviors, positive talk, psychosocial counseling, psychosocial question asking, and emotionally focused talk. There were no gender differences evident in the amount, quality, or manner of biomedical information giving or social conversation. Medical visits with female physicians are, on average, 2 minutes (10%) longer than those with male physicians. Obstetrics and gynecology may present a different pattern than that of primary care, with male physicians demonstrating higher levels of emotionally focused talk than their female colleagues. CONCLUSIONS: Female primary care physicians engage in more communication that can be considered patient centered and have longer visits than their male colleagues. Limited studies exist outside of primary care, and gender-related practice patterns in some subspecialties may differ from those evident in primary care.

Communication↗
PubMed2001

Nateglinide therapy for type 2 diabetes mellitus.

OBJECTIVE: To review the pharmacology, pharmacokinetics, dosing guidelines, adverse effects, drug interactions, and clinical efficacy of nateglinide. DATA SOURCES: Primary and review articles regarding nateglinide were identified by MEDLINE search (from 1966 to January 2001); abstracts were identified through the Institute for Scientific Information Web of Science (from 1995 to January 2001) and the American Diabetes Association; additional information was obtained from the nateglinide product information. STUDY SELECTION/DATA EXTRACTION: All articles and meeting abstracts identified from the data sources were evaluated and all information deemed relevant was included in this review. Much of the information was from abstracts or the product labeling, since few clinical studies have been published in the medical literature. DATA SYNTHESIS: Nateglinide is a novel nonsulfonylurea oral antidiabetic agent that stimulates insulin secretion from the pancreas. It has a rapid onset and short duration of action, allowing administration before a meal to reduce postprandial hyperglycemia. Improvement in glycemic control with nateglinide monotherapy has been demonstrated in patients not previously treated with antidiabetic medications. Greater improvement in glycemic control was observed when nateglinide was administered in combination with metformin. CONCLUSIONS: Nateglinide is similar to repaglinide, but has a quicker onset of action, quicker reversal, and does not usually require dosage titration. Based on the pharmacodynamics of nateglinide and repaglinide, nateglinide produces a more rapid postprandial increase in insulin secretion, and its duration of response is shorter than that of repaglinide. The risk of postabsorptive hypoglycemia should be lower than with either sulfonylureas or repaglinide.

Animals↗
PubMed2006

781 Mbit/s photon-counting optical communications using a superconducting nanowire detector.

We demonstrate 1550 nm photon-counting optical communications with a NbN-nanowire superconducting single-photon detector. Source data are encoded with a rate-1/2 forward-error correcting code and transmitted by use of 32-ary pulse-position modulation at 5 and 10 GHz slot rates. Error-free performance is obtained with -0.5 detected photon per source bit at a source data rate of 781 Mbits/s. To the best of our knowledge, this is the highest reported data rate for a photon-counting receiver.

Journal Article↗
PubMed1992

Manipulation in close relationships: five personality factors in interactional context.

This research had three basic goals: (a) to identify manipulation tactics used in close relationships; (b) to document empirically the degree of generality and specificity of tactical deployment across relationship types (mates, friends, parents); and (c) to identify links between five major personality dimensions and the usage of manipulation tactics. Twelve manipulation tactics were identified through separate factor analyses of two instruments based on different data sources: Charm, Reason, Coercion, Silent Treatment, Debasement, and Regression (replicating Buss et al., 1987), and Responsibility Invocation, Reciprocity, Monetary Reward, Pleasure Induction, Social Comparison, and Hardball (an amalgam of threats, lies, and violence). The Big Five personality factors were assessed through three separate data sources: self-report, spouse report, and two independent interviewers. Personality factors showed coherent links with tactics, including Surgency (Coercion, Responsibility, Invocation), Desurgency (Debasement), Agreeableness (Pleasure Induction), Disagreeableness (Coercion), Conscientiousness (Reason), Emotional Instability (Regression), and Intellect-Openness (Reason). Discussion focuses on the consequences of the five personality factors for social interaction in close relationships.

Adolescent↗
PubMed2006

Monitoring the scale-up of antiretroviral therapy programmes: methods to estimate coverage.

This paper reviews the data sources and methods used to estimate the number of people on, and coverage of, antiretroviral therapy (ART) programmes in low- and middle-income countries and to monitor the progress towards the "3 by 5" target set by WHO and UNAIDS. We include a review of the data sources used to estimate the coverage of ART programmes as well as the efforts made to avoid double counting and over-reporting. The methods used to estimate the number of people in need of ART are described and expanded with estimates of treatment needs for children, both for ART and for cotrimoxazole prophylaxis. An estimated 6.5 million people were in need of treatment in low- and middle-income countries by the end of 2004, including 660,000 children under age 15 years. The mid-2005 estimate of 970,000 people receiving ART in low- and middle-income countries (with an uncertainty range 840,000-1,100,000) corresponds to a coverage of 15% of people in need of treatment.

Adolescent↗
PubMed1999

Estimation of spatially resolved road transport emissions for air quality management applications in the north west region of England

Spatially resolved estimates of combustion and non-combustion related emissions of CO, NOx, VOCs and PM from road transport sources have been made for the North West region of England in 1994. These have been generated using detailed emissions models for combustion related emissions of CO, NOx, VOCs and PM which take into account the different emissions profiles associated with particular vehicle groups, different road types and journeys under cold start conditions. Emissions estimates have been generated for a 1 x 1 km grid covering the region's urban and industrial zones and a 5 x 5 km grid for the whole study area. Emissions models have been generated and applied within a Geographical Information System (GIS) environment. Areas of uncertainty in the estimation procedure have been examined and the results compared with alternative data sources. Although the work centres upon the North West region of England, as far as possible the methods and data sources used are intended to be generic, particularly in respect to other administrative areas of the UK. In this way, this work can be considered to be of wider interest than at the local level alone.

Journal Article↗
PubMed2004

Driver's licenses as a source of data on height and weight.

We investigated the feasibility of using driver's license records to obtain height and weight data of individuals. First, we linked Washington State driver's license records (DOL) to the state birth files to assess how well driver's licenses can be linked to a public health database. We were able to match 78.4% of mothers and 71.7% of fathers on birth records to driver's license records. Then we assessed the accuracy of DOL height and weight data by comparing them to heights and weights measured on control women enrolled in a cancer etiology study (CES). There is a close relation between CES and DOL heights, but not a close relation between weights. Our results suggest that driver's license files are a good source of information for women's heights, but are not as good for women's weights.

Automobile Driving↗
PubMedDate not supplied

Steady-state pharmacokinetics of phenytoin from routinely collected patient data.

Previously reported routine phenytoin clinical pharmacokinetic data from Japan, England, and Germany were analysed to estimate population pharmacokinetic parameters. There were 780 steady-state phenytoin concentrations and associated dosage rates (mg/day) from 322 patients. The patient group spanned paediatric and adult ages, mean age being 18.4 +/- 17.3 (SD) years; 53% were males. The data were analysed using NONMEM, a computer programme designed for population pharmacokinetic analysis. Estimates of the influence of age, gender, data source, height and weight on the maximum elimination rate (Vm) and Michaelis-Menten constant (Km) were obtained. The Vm and Km of a 70 kg adult male European were estimated to be 415 mg/day and 5.7 mg/L, respectively. Vm is not influenced by gender, age or data source. The parameters of a power function of height and weight were estimated to adjust Vm for body size. The best function adjusts Vm in proportion to weight to the 0.6 power; height contains no useful information. Km is not influenced by gender. The Km for patients less than 15 years old is 43% less than that of older patients. The Km of Japanese patients appears to be 23% less than that for European patients. Even after adjustments for age, etc., apparent Vm and Km vary unpredictably among individuals with a coefficient of variation between 10 to 20% and approximately 50% respectively.

Adolescent↗
PubMed2026

An introductory practical guide to secondary data analysis in pediatric urology.

INTRODUCTION: Secondary data analysis (SDA) has become an increasingly important approach in pediatric urology, enabling the study of long-term outcomes, care variation, and disparities in populations with chronic or congenital urologic conditions. With the growing availability of large datasets, a structured approach to designing and conducting SDA studies is increasingly relevant. OBJECTIVES: To provide an introductory, practical guide to SDA in pediatric urology by (1) summarizing commonly used data sources with representative studies, (2) outlining a stepwise approach to designing and executing SDA studies, and (3) highlighting key methodological considerations, limitations, and opportunities for future work. STUDY DESIGN: Narrative review of existing literature and commonly used datasets relevant to pediatric urology, including administrative claims, hospital encounter databases, clinical registries, electronic health record networks, and population-based surveys. RESULTS: Data sources differ in scope, clinical granularity, longitudinal follow-up, and representativeness, and each is suited to specific research questions. We present a practical workflow for SDA, including dataset selection, cohort definition, and analytic planning. Linkage across datasets can provide a more comprehensive view of care patterns and outcomes, although feasibility is influenced by legal, technical, and data-quality constraints. DISCUSSION: SDA enables population-level analyses and the study of rare conditions that are challenging to evaluate through single-center or prospective designs. However, careful cohort definition, feasibility assessment, and awareness of data limitations are essential to ensure validity and interpretability. CONCLUSION: SDA provides a scalable, cost-efficient framework for generating meaningful evidence in pediatric urology. Continued efforts to harmonize data elements, improve linkage infrastructure, and support cross-institution collaboration will enhance the quality and impact of future research. This article provides a practical framework and examples to support the design and execution of SDA studies.

Humans↗
PubMed2000

Chorioamnionitis as a risk factor for cerebral palsy: A meta-analysis.

CONTEXT: Chorioamnionitis has been implicated in the pathogenesis of cerebral palsy, but most studies have not reported a significant association. Cystic periventricular leukomalacia (cPVL) is believed to be a precursor of cerebral palsy in preterm infants. OBJECTIVES: To determine whether chorioamnionitis is associated with cerebral palsy or cPVL and to examine factors that may explain differences in study results. DATA SOURCES: Searches of MEDLINE (1966-1999), Index Medicus (1960-1965), Doctoral Dissertation Abstracts On-Line (1861-1999), bibliographies, and online conference proceedings (1999) were performed for English-language studies with titles or abstracts that discussed prenatal risk factors for cerebral palsy or cPVL. STUDY SELECTION: Of 229 initially identified publications, meta-analyses were performed on studies that addressed the association between clinical (n = 19) or histologic (n = 7) chorioamnionitis and cerebral palsy or cPVL in both preterm and full-term infants. Inclusion criteria were: presence of appropriate exposure and outcome measures, case-control or cohort study design, and provision of sufficient data to calculate relative risks (RRs) or odds ratios with 95% confidence intervals (CIs). Studies evaluating risk of cerebral palsy following maternal fever, urinary tract infection, or other maternal infection were collected, but not included in the meta-analysis. DATA EXTRACTION: Information from individual studies was abstracted using standardized forms by 2 independent observers blinded to authors' names, journal titles, and funding sources. DATA SYNTHESIS: Using a random effects model, clinical chorioamnionitis was significantly associated with both cerebral palsy (RR, 1.9; 95% CI, 1.4-2.5) and cPVL (RR, 3.0; 95% CI, 2.2-4.0) in preterm infants. The RR of histologic chorioamnionitis and cerebral palsy was 1.6 (95% CI, 0.9-2.7) in preterm infants, and histologic chorioamnionitis was significantly associated with cPVL (RR, 2.1; 95% CI, 1.5-2.9). Among full-term infants, a positive association was found between clinical chorioamnionitis and cerebral palsy (RR, 4.7; 95% CI, 1.3-16.2). Factors explaining differences in study results included varying definitions of clinical chorioamnionitis, extent of blinding in determining exposure status, and whether individual studies adjusted for potential confounders. CONCLUSION: Our meta-analysis indicates that chorioamnionitis is a risk factor for both cerebral palsy and cPVL. JAMA. 2000;284:1417-1424.

Cerebral Palsy↗
PubMed2004

Safety of calcium dobesilate in chronic venous disease, diabetic retinopathy and haemorrhoids.

The aim of the present review is to consider the adverse effects and the safety profile of calcium dobesilate. Calcium dobesilate (Doxium) is a veno-tonic drug, which is widely prescribed in more than 60 countries from Europe, Latin America, Asia and the Middle East for three main indications: chronic venous disease, diabetic retinopathy and the symptoms of haemorrhoidal attack. Data sources used for this review comprise the international literature (1970-2003), a postmarketing surveillance (PMS) report for calcium dobesilate from OM Pharma (Geneva, Switzerland) covering the period 1974-1998, and periodic safety update reports (PSUR) covering the period 1995-2003 from the French Regulatory authorities pharmacovigilance database and OM Pharma. Data from the PMS report for 1974-1998 indicated that adverse events with calcium dobesilate did not occur very frequently and had the following distribution in terms of frequency: fever (26%), gastrointestinal disorders (12.5%), skin reactions (8.2%), arthralgia (4.3%), and agranulocytosis (4.3%). No deaths were attributed to calcium dobesilate in the PMS report. Using data on product use in the Swiss Compendium we estimated the prevalence of agranulocytosis to be 0.32 cases/million treated patients, i.e. ten times less than the calculated prevalence of agranulocytosis in the general population. Most adverse events are type B, i.e. rare and unrelated to the pharmacological properties of calcium dobesilate. This review concludes that the risk of an adverse effect with calcium dobesilate 500-1500 mg/day is low and constant over time. The recently raised problem of agranulocytosis (a total of 13 known cases drawn from all data sources) appears to be related to methodological bias. Such a review reinforces the need for a strong international pharmacovigilance organisation using similar methods to detect and analyse the adverse effects of drugs.

Animals↗