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Biomedical subjects

E J Stanek

Publications and source records attributed to E J Stanek.

At least 37 records · Page 2Linked to original sources
PubMed1997

Treatment patterns for heart failure in a primary care environment.

Little published information regarding current pharmacotherapeutic treatment patterns for congestive heart failure (CHF) in nonacademic, ambulatory care settings is available. We sought to assess, in a nonacademic primary care environment, pharmacotherapeutic treatment patterns for CHF with respect to consistency with clinical trial evidence and published treatment guideline recommendations. Over an 18-month period, we examined CHF pharmacotherapy using a computerized, integrated clinical diagnoses and prescription database from an outpatient community healthcare center without academic affiliations. We identified adult patients meeting contact criteria and with diagnosis of CHF by International Classification of Diseases (ICD-9-CM) coding and assessed prescribed therapy as well as select comorbid conditions. Drugs of interest included those with known or suspected benefit or detriment and those with unproven benefit. An eligible group of 14,983 patients was identified, from which a cohort of 148 patients with CHF was selected. Forty-one percent of these 148 patients were prescribed an angiotensin converting enzyme (ACE) inhibitor, 34% digoxin, 12% diuretic, 12% hydralazine + nitrate, 20% inhaled beta-agonists, and 66% warfarin. Only 5% of patients were prescribed the combination of an ACE inhibitor, digoxin, and diuretic. Thirty-one percent had a comorbid diagnosis of atrial fibrillation, of whom 44% were prescribed digoxin, 22% diltiazem, 15% beta-blockers, 15% digoxin and diltiazem, 7% digoxin and a beta-blocker, and 33% warfarin. In general, recommended therapies for CHF appeared underutilized in this cohort, whereas those of unclear benefit and potential detriment appeared overutilized. Although these results may not be readily generalized to the entire healthcare system, they do suggest a need for additional analysis and potential intervention.

Adolescent↗
PubMed1996

Unilateral vs. bilateral carpal tunnel: challenges and approaches.

Conditions affecting either or both extremities offer unique opportunities and challenges for investigators and clinicians. When the condition is purely unilateral, observations on the unaffected extremity may be used as a within-patient control, and thereby strengthen the ability to identify changes in the affected limb. However, such use presumes that the condition will not subsequently develop in the unaffected extremity. Bilateral presentations or subsequent development of disease in the unaffected extremity is common in conditions such as the carpal tunnel syndrome (CTS). Treatment of one extremity may lead to development or aggravation of CTS in the other extremity. Since both extremities may be necessary to perform certain activities, it can be difficult to clearly identify treatment effects when looking at functional outcomes. In an effort to avoid these complexities, investigators have used one of two approaches in studying CTS: either selecting only those patients with unilateral disease, or analyzing results by extremity, often avoiding any outcome measures that might depend upon both extremities (such as driving). We illustrate some of the shortcomings of this approach, such as loss of patients and data, with preliminary information from our ongoing prospective study of carpal tunnel surgery outcomes. We develop a dynamic model that incorporates etiologic factors and treatment effects to describe changes in CTS over time. This model accounts for extremity-specific and systemic factors, as well as possible interaction of the disease process in both hands. The advantages of this model include a more rational approach to research and care of extremity disorders, and research strategies which address a wider scope of patients and outcomes; however, its application is limited by the need for more extensive data collection.

Carpal Tunnel Syndrome↗
PubMed1996

Methodology to estimate the amount and particle size of soil ingested by children: implications for exposure assessment at waste sites.

Despite considerable efforts to improve the design of soil ingestion studies, substantial variability in daily soil ingestion rates based on different tracer estimates exists in the same subjects. The present study assessed the hypothesis that one of the unexplored causes of this intertracer variation in soil ingestion estimation was related to differences in soil tracer concentration by particle size. The study analyzed the tracer concentration in soil for children in the Anaconda, Montana soil ingestion study for the particle size fraction less than 250 microm [corrected] in diameter. Soil ingestion estimates for these children were recalculated based on the new soil concentration values and compared to previous findings (E. J. Calabrese, E. J. Stanek, P. Pekow, and R. M. Barnes, submitted, 1996) when the soil concentrations were determined for soil particle size diameter of <2 mm. The results indicated that five tracers (Al, Si, Ti, Y, and Zr) did not have their soil concentrations changed by particle size. However, for three tracers (La, Ce, and Nd) the concentration increased by two- to fourfold with the smaller particle size. Recalculation of soil ingestion estimates indicates that the soil ingestion estimates of the five tracers not varying by particle size did not change while those of the remaining three tracers were decreased by approximately 60%. The revised calculations provide a substantial improvement in intertracer estimates of soil ingestion and suggest that the children ingested soil of small particle size. These findings are of significance since they (1) identify an important potential cause of intertracer variability in soil ingestion estimates, (2) establish a new criterion for soil tracer selection, and (3) develop a method for not only providing improved soil ingestion estimates but also determining the particle size of the ingested soil. These findings offer important potential applications for risk assessment practices at contaminated sites since soil ingestion is frequently the dominant route of estimated contaminant exposure in children.

Child↗
PubMed1996

A prospective study of early pregnancy loss.

The New York State Early Pregnancy Detection Study was a prospective study of early pregnancy loss, between implantation and menses, in 217 women attempting to become pregnant during 1989-1992. Women collected urine samples on three consecutive mornings during the late luteal phase of their menstrual cycle, for up to 12 cycles, contributing samples for 1253 menstrual cycles. Urinary human chorionic gonadotrophin (HCG), measured using an immunoradiometric assay, was the biomarker for pregnancy. We observed a range of early pregnancy loss (EPL) rates, from a low estimate of 11.0% to a high estimate of 26.9%, depending on the definition used and the subgroup analysed. Based on a definition of 3 days of HCG concentration > or = 4.00 pmol/l, 2 days > or = 5.33 pmol/l or the last day of HCG > or = 6.67 pmol/l, we identified 115 positive cycles; 95 cycles were clinically confirmed pregnancies and 20 cycles were EPL, giving an EPL rate of 17.4% [95% confidence interval (CI) 11.0-25.6]. In addition, we observed an EPL rate of 19.5% (95% CI 11.3-30.1) for samples collected within a 15 day window around menses, and a rate of 20.3% (95% CI 11.3-32.2) for samples limited to the first three menstrual cycles. Because studies use urine collection schemes other than daily sampling, the definition of pregnancy will be crucial in defining EPL.

Abortion, Spontaneous↗
PubMed1995

A dog's tale: soil ingestion by a canine.

A single Irish Setter pet dog had its soil ingestion behavior quantitatively estimated on 3 consecutive days via a soil tracer-based mass-balance methodology. The results indicated a high agreement among the eight tracers (Al, Si, Ti, Y, Zr, La, Ce, and Nd) employed to estimate soil ingestion. The estimated daily soil ingestion rate ranged from approximately 10 to 20 g/day depending on the tracer. This represents a value far exceeding soil ingestion reported by an "average" child (ranging from 30 to 50 mg/day). The several hundred-fold higher soil ingestion rate in this dog compared to soil ingestion by an average child suggests the need to evaluate more fully soil and dust ingestion in domestic animals and wildlife especially with respect to potential exposure to contaminants in soil.

Animals↗
PubMed1995

Work-related upper-extremity disorders and work disability: clinical and psychosocial presentation.

Work-related upper-extremity disorders (WRUEDs) are an increasingly common cause of work-related symptoms and disability. Although most upper-extremity disorders are acute and self-limited, a small percentage of workers with symptoms go on to permanent disability and account for the majority of costs associated with these conditions. Little is known, however, about this progression from symptoms to disability and how it might be prevented. In this study, we evaluate the demographic, vocational, medical, and psychosocial characteristics of patients with WRUEDs and examine several hypotheses regarding the differences between working and work-disabled patients. One hundred twenty-four consecutive patients were evaluated in a clinic specializing in occupational upper-extremity disorders. Patients currently working (n = 55) and work-disabled patients (n = 59) were similar with regard to age, gender, and reported job demands. The work-disabled group reported less time on the job, more surgeries, a higher frequency of acute antecedent trauma, and more commonly had "indeterminate" musculoskeletal diagnoses. They also reported higher pain levels, more anger with their employer, and a greater psychological response or reactivity to pain. These findings, though cross-sectional in nature, suggest that, in addition to medical management, more aggressive approaches to pain control, prevention of unnecessary surgery, directed efforts to improve patients' abilities to manage residual pain and distress, and attention to employer-employee conflicts may be important in preventing the development of prolonged work disability in this population.

Adult↗
PubMed1995

Xanthine interference with dipyridamole-thallium-201 myocardial imaging.

Both theophylline and caffeine have been shown to antagonize adenosine and are associated with false-negative test results with dipyridamole-T1-201 imaging. This has led to recommendations for theophylline and caffeine abstinence for at least 24 hours prior to dipyridamole-T1-201 imaging. Because pentoxifylline and its metabolites are structurally similar to theophylline and caffeine, and pentoxifylline has adenosine antagonistic properties, one might presume that pentoxifylline may also attenuate the diagnostic yield of dipyridamole-T1-201 imaging. To the best of our knowledge, the pharmacodynamic interaction between pentoxifylline and dipyridamole and its effects on dipyridamole-T1-201 imaging in patients have never been studied adequately. However, a single study in 7 dogs does suggest that there may be no significant interaction. In addition, we must also consider the nonacute nature of the clinical use of pentoxifylline in peripheral vascular disease and the critical need for accurate dipyridamole-T1-201 imaging results and the cost associated with this procedure. Until such information is available in humans, it would be prudent to discontinue pentoxifylline, in addition to caffeinated foods, caffeine-containing drug products, and theophylline, at least 24 hours prior to dipyridamole-T1-201 imaging.

Adenosine↗
PubMed1995

Activated clotting time versus activated partial thromboplastin time for therapeutic monitoring of heparin.

OBJECTIVE: To compare and contrast the activated partial thromboplastin time (aPTT) and the activated clotting time (ACT) for the therapeutic monitoring of heparin therapy. DATA SOURCES: Relevant articles were identified through an English-language MEDLINE search from 1966 to 1995. Additional sources were identified from the reference lists of these articles. STUDY SELECTION: Studies that investigated the use and limitations of the individual assays and those offering direct comparisons were chosen for review. DATA EXTRACTION: Features demonstrating clinical applications and limitations of the aPTT and the ACT were extracted. Where possible, data suggesting preferential application of either assay also were extracted. DATA SYNTHESIS: Both the aPTT and ACT are clinically useful for the monitoring of heparin therapy. The aPTT is used more frequently for routine monitoring; the ACT is used in specialized situations requiring large heparin doses. The ACT is typically performed at bedside and is capable of yielding results rapidly and perhaps at a lower cost than an aPTT performed by a central laboratory. Most practitioners are familiar with the central laboratory aPTT. A bedside aPTT device is available, but is not yet in widespread clinical use. Both assay techniques are subject to various limitations. CONCLUSIONS: The ACT is theoretically equally as useful as the aPTT for the routine monitoring of heparin therapy, but has not been well-studied. The ACT appears more useful in situations in which high serum concentrations of heparin are required. Further cost-effectiveness and clinical outcome studies directly comparing the ACT and the aPTT is specific clinical situations are needed.

Anticoagulants↗
PubMed1995

Daily estimates of soil ingestion in children.

Soil ingestion estimates play an important role in risk assessment of contaminated sites, and estimates of soil ingestion in children are of special interest. Current estimates of soil ingestion are trace-element specific and vary widely among elements. Although expressed as daily estimates, the actual estimates have been constructed by averaging soil ingestion over a study period of several days. The wide variability has resulted in uncertainty as to which method of estimation of soil ingestion is best. We developed a methodology for calculating a single estimate of soil ingestion for each subject for each day. Because the daily soil ingestion estimate represents the median estimate of eligible daily trace-element-specific soil ingestion estimates for each child, this median estimate is not trace-element specific. Summary estimates for individuals and weeks are calculated using these daily estimates. Using this methodology, the median daily soil ingestion estimate for 64 children participating in the 1989 Amherst soil ingestion study is 13 mg/day or less for 50% of the children and 138 mg/day or less for 95% of the children. Mean soil ingestion estimates (for up to an 8-day period) were 45 mg/day or less for 50% of the children, whereas 95% of the children reported a mean soil ingestion of 208 mg/day or less. Daily soil ingestion estimates were used subsequently to estimate the mean and variance in soil ingestion for each child and to extrapolate a soil ingestion distribution over a year, assuming that soil ingestion followed a log-normal distribution.

Child, Preschool↗
PubMed1995

Resolving intertracer inconsistencies in soil ingestion estimation.

In this article we explore sources and magnitude of positive and negative error in soil ingestion estimates for children on a subject-week and trace element basis. Errors varied among trace elements. Yttrium and zirconium displayed predominantly negative error; titanium and vanadium usually displayed positive error. These factors lead to underestimation of soil ingestion estimates by yttrium and zirconium and a large overestimation by vanadium. The most reliable tracers for soil ingestion estimates were aluminum, silicon, and yttrium. However, the most reliable trace element for a specific subject-day (or week) would be the element with the least error during that time period. The present analysis replaces our previous recommendations that zirconium and titanium are the most reliable trace elements in estimating soil ingestion by children. This report identifies limitations in applying the biostatistical model based on data for adults to data for children. The adult-based model used data less susceptible to negative bias and more susceptible to source error (positive bias) for titanium and vanadium than the data for children. These factors contributed significantly to inconsistencies in model predictions of soil ingestion rates for children. Correction for error at the subject-day level provides a foundation for generation of subject-specific daily soil ingestion distributions and for linking behavior to soil ingestion.

Adult↗
PubMed1994

Arterial oxygen saturation in chronic congestive heart failure.

Continuous, 24-hour, ambulatory pulse oximetry was used in 10 subjects with New York Heart Association functional class II to III heart failure and in 5 age-matched controls to test the prevailing view that arterial oxygen saturation is preserved during wakefulness in chronic mild to moderate heart failure. Subjects with heart failure were stabilized on digitalis and diuretics at the time of the study. All subjects maintained time-activity logs, with an emphasis on self-reported sleep and wakefulness. A desaturation event was defined as a decrease in arterial oxygen saturation > or = 4% from baseline lasting > 5 seconds. Variables assessed included total desaturation events, decrease in arterial oxygen saturation duration/event, nadir of arterial oxygen saturation/event, and desaturation index ([cumulative desaturation time/total monitoring time] x 100). The ratio of self-reported wakefulness:sleep desaturation time was 47:53% for subjects with heart failure versus 64:36% for controls (p = NS). Mean (+/- SEM) time of arterial oxygen saturation < 90% was 123 +/- 67 minutes for subjects with heart failure versus 22 +/- 25 minutes for controls (p < 0.01). Total desaturations were 220 +/- 63 and 76 +/- 35 (p = NS) for the heart failure and control groups, respectively. The heart failure group had a statistically, significantly greater decrease in arterial oxygen saturation, and a longer duration and deeper nadir of the desaturation event than did the age-matched control group. The desaturation index was 21 +/- 3% and 4 +/- 1% for the heart failure and control groups, respectively (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Characteristics related to the incidence and prevalence of acute respiratory tract infection in young children in Kenya.

Acute respiratory tract infection (ARI) in children is a prevalent condition that results in substantial morbidity and consumes large portions of health care resources in developing countries. We examined factors associated with the reported incidence and prevalence of ARI in a 3-year longitudinal study of 485 children < 5 years of age in rural Kenya. A large number of environmental factors, household and family characteristics, and child-specific factors were examined with use of multivariable methods. Few variables that may play a role in the incidence and prevalence of ARI (e.g., household tobacco use and weight z-score) were found to be related to such rates. Several factors related to ARI incidence and prevalence (e.g., mother's age, number of children, and community) were found to be associated with only mild ARI episodes. Evidence is presented to support the hypothesis that these factors are related to differential reporting of mild ARI episodes. The impact of such differential reporting on health care utilization and health education is discussed.

Child, Preschool↗
PubMed1992

The interactive effects of dietary quality on the growth and attained size of young Mexican children.

Predictors of attained size at 30 mo and growth rate between 18 and 30 mo (eg, diet, maternal size, morbidity, age at weaning, and selected environmental factors) were investigated by using longitudinal data from 67 Mexican children aged 18-30 mo. These children were small because of growth stunting in early infancy. Between 18 and 30 mo they grew on average at the 50th percentile of National Center for Health Statistics references values for weight, and the 25th for length. Size at 30 mo and growth rates were unrelated to energy or protein intakes during the previous year, but positively related to consumption of animal-origin foods. Maternal weight predicted size and growth only for children with larger intakes of animal products. Individual rates of weight and length growth were uncorrelated on average, correlated negatively when animal-product intake was low, and positively only when more animal products were consumed. Integrated weight and length growth, and the influence of maternal size on growth, may be disrupted by poor dietary quality. Different children would be identified as malnourished depending on whether weight or length growth was measured.

Analysis of Variance↗
PubMed1991

Estimating prediction equations in repeated measures designs.

Experimental designs with repeated measures allow response patterns over time (or dose) to be modelled and compared between different homogeneous groups. Issues in data analysis often focus on the pattern of variation of the repeated measures, the appropriateness of a univariate or multivariate analysis, and the shape of the response pattern. An aspect of analysis that is often of equal importance is the development of a regression model for response once the pattern has been characterized. Analysis of variance or multivariate growth curve results often do not include easily interpretable regression equation estimates that can be used for prediction. We present methods and tables that permit simple construction of such predictive equations for repeated measures designs when response is modelled as a polynomial over time with univariate or multivariate analyses.

Exercise↗
PubMed1991

A guide to interpreting soil ingestion studies. I. Development of a model to estimate the soil ingestion detection level of soil ingestion studies.

This paper provides a model with which to predict soil ingestion recovery values in soil ingestion studies either retrospectively or prospectively. The predictive equations generated from the model can be used to estimate minimum soil ingestion detection levels from soil ingestion studies which use mass-balance methods. The model is derived from data assessing soil recovery efficiencies in adults using eight different predictive tracer elements. The results constitute a methodology for determining minimum detection levels of soil ingestion and hence have important regulatory significance.

Humans↗
PubMed1991

A guide to interpreting soil ingestion studies. II. Qualitative and quantitative evidence of soil ingestion.

Four major studies have attempted to qualitatively and quantitatively assess the extent of soil ingestion in children using the soil tracer methodology. The validity of the estimates of soil ingestion in each study was reevaluated in light of the inherent strengths and limitations of study design and/or execution, as well as via a novel methodology for estimating the soil recovery variance for each tracer, which then led to the estimation of soil ingestion detection limits for each tracer for studies performing mass-balance analyses. Based on these analyses it is concluded that the Binder et al. (1986, Arch. Environ. Health 41, 341-345) and Van Wijnen et al. (1990, Environ. Res. 51, 147-162) studies provide no convincing evidence to support qualitative and quantitative estimates of soil ingestion due to inherent limitations in their respective study designs. The Davis et al. (1990, Arch. Environ. Health 45, 112-122) and Calabrese et al. (1989, Regul. Toxicol. Pharmacol. 10, 123) studies displayed convincing qualitative evidence of soil ingestion. However, the results indicate that the median soil ingestion estimates of Davis et al. were less reliable than those of Calabrese et al. The range of detection limits vary according to the tracer and the assumption of acceptable precision in recovery estimation. The minimum detection level of soil ingestion in children in the Calabrese et al. study, with a variance in recovery of 100% +/- 20%, was 21 mg/day based on Zr.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Evidence of soil-pica behaviour and quantification of soil ingested.

A previously published report on soil ingestion in children, revealed evidence that one of the subjects, a 3.5-year-old female, displayed soil-pica behaviour. Soil ingestion estimates for this child ranged from approximately 5 to 7 g d-1 for seven of eight soil tracers employed. The present paper revealed that the soil-pica behaviour occurred only in the second of the two weeks of observation, during which daily soil ingestion rates ranged from 10 to 13 g d-1. Tracer recovery studies displayed acceptable precision (i.e. 100% less than +/- 30%) for six of the eight tracers during the soil-pica episode (week 2). Evaluation of the weekly soil ingestion values of the remaining 63 subjects indicated no convincing evidence of soil-pica behaviour in this group of children aged 1-4.

Child Behavior↗