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Biomedical subjects

P Pekow

Publications and source records attributed to P Pekow.

9 recordsLinked to original sources

Soil ingestion in adults--results of a second pilot study.

Soil ingestion was evaluated in 10 adults as part of a larger study to evaluate soil ingestion in children. Each adult was followed for 4 weeks in a mass-balance study that was designed to evaluate the detection limit for soil ingestion in a similarly designed, concurrent children's study. After a baseline week, during Weeks 2 through 4, adults received daily soil capsules containing 20, 100, and 500 mg of soil, respectively. A 1-week period separated each study week. Based on the first 3 weeks of observation after subtracting the capsule ingestion amounts, the median, 75th percentile, and 95th percentile soil ingestion estimates were 1, 49, and 331 mg/day, with estimates calculated as the median of the three trace elements Al, Si, and Y. The average estimate of soil ingestion was 10 mg/day (SD = 94 mg/day). These findings augment sparse empirical data on adult soil ingestion, and suggest lower levels of soil ingestion in adults than previous studies.

Adult↗

Soil ingestion estimates for children residing on a superfund site.

Soil ingestion estimates were obtained from a stratified, simple random sample of 64 children aged 1-4 years residing on a superfund site in Montana. The study was conducted during the month of September for 7 consecutive days. The study utilized a mass-balance methodology in which eight naturally occurring soil tracers (Al, Si, Ti, Ce, Nd, La, Y, and Zr) believed to be poorly absorbed by the gastrointestinal tract were employed to provide soil ingestion estimates. Food and fecal samples were analyzed on a daily basis. Soil/dust samples representative of where the children played during the study period were obtained. Very high compliance among the participants was maintained throughout the study. The identical methodology employed in the childrens' study was used in an adult study of tracer recovery in 10 subjects over 28 days of observation to provide validation that soil ingestion over the range of 20 to 500 mg/day could be detected. Soil ingestion was estimated by each soil tracer via traditional methods as well as by an improved approach using five trace elements (Al, Si, Ti, Y, and Zr), called the Best Tracer Method (BTM), which substantially corrects for error due to misalignment of tracer input and output as well as error occurring from ingestion of tracers from nonfood, nonsoil sources, while being insensitive to the particle size of the soil/dust ingested. According to the BTM, the median soil ingestion was less than 1 mg/day while the upper 95% was 160 mg/day. No significant age (1 year vs 2, vs 3) or sex-related differences in soil ingestion were observed. These estimates are lower than estimates observed in another study in Massachusetts during September and October. Significant methodological improvements in this study as compared to previously conducted soil ingestion studies include the selection of a representative sample of children, longer study duration, inclusion of dietary recommendations to reduce food tracer input and variability, use of the BTM, and a stronger adult validation study with respect to number of subjects, and duration and range of possible soil ingestion rates. Despite these methodological improvements, evidence exists that this study displays a net residual negative error, suggesting that the above estimates are below the true soil ingestion. The magnitude of this residual negative error cannot be quantified with the BTM but is likely to not affect the median by more than 40 mg/day, while the impact of such an error on the upper end of the distribution is more uncertain.

Adult↗

Smoking cessation and severity of disease: the Coronary Artery Smoking Intervention Study.

We tested the effectiveness of an individually delivered behavioral multicomponent smoking intervention (SI) against offering advice only (AO) to 267 patients after coronary arteriography. After 6 months, 51% of AO patients and 62% of SI patients reported abstinence. Validated rates were 34% and 45% for AO and SI patients, respectively. Logistic regression analyses, controlling for severity of illness, stage of change, and self-efficacy, among other variables, showed that, at 6 months, the SI had the most effect for patients with more severe coronary artery disease (CAD) who had been admitted with a myocardial infarction (95% confidence interval = 2.05, 124.85). At 12 months, only severity of disease mediated SI effects (95% confidence interval = 3.10, 58.00). Similar results were seen for cotinine-validated cessation. This study confirms the effectiveness of individually administered SI for more seriously ill patients with CAD and raises questions as to how to better intervene with those individuals with less severe disease.

Attitude to Health↗

Effect of normothermic blood cardioplegia on postoperative conduction abnormalities and supraventricular arrhythmias.

BACKGROUND: Conduction defects and supraventricular tachycardia (SVT) are common after myocardial revascularization using current methods of cold hyperkalemic blood or crystalloid cardioplegia. The current retrospective study was undertaken to assess the influence of normothermic blood cardioplegia on conduction defects and SVT. METHODS AND RESULTS: The initial 92 patients underwent cardiopulmonary bypass (CPB) at 28 degrees C and blood cardioplegia at 6-8 degrees C. The subsequent 120 patients underwent CPB and blood cardioplegia at 37 degrees C. In all patients, cardioplegia was initially given by a combined antegrade/retrograde technique. The incidence of new postoperative conduction disturbances was significantly less in the normothermic group (p < 0.001): 27.5% versus 57.6% immediately after surgery; 9.2% versus 41.3% 1 day after surgery; 4.2% versus 32.6% 2 days after surgery; 1.7% versus 19.6% on hospital discharge; and 1.7% versus 17.4% on late follow-up. The incidence of supraventricular arrhythmias was not statistically different: 40.0% warm versus 42.4% cold. The groups were identical except that mean cross-clamp times were significantly longer (73.8 versus 60.1 minutes), mean number of grafts were significantly higher (3.7 versus 3.4), and mean cardioplegia volume was significantly greater (5,627 versus 3,710 ml) in the warm group (p < 0.05). In addition, the warm group had a higher incidence of prior transmural anterior myocardial infarctions (35% versus 9.8%, p < 0.001) and emergency operation (16.7% versus 6.5%, p < 0.05). Creatine kinase (CK) MB release was significantly less in the warm group immediately after operation (24.9 versus 60.9 units/l) and on POD1 (19.2 versus 46.5 units/l) (p < 0.001). CONCLUSIONS: Normothermic cardioplegia is associated with a marked decrease in new and permanent conduction disturbances and postoperative CK-MB release. This suggests that a significant factor in the pathogenesis of conduction blocks is cold-related injury. Supraventricular arrhythmias were not affected by the type of cardioplegia given.

Blood↗

A study of spirometry in children from Mexico City.

A study was conducted in two elementary schools in Mexico City to determine values for pulmonary function tests in school-aged residents of Mexico City. The schools were located in Xalostoc, a highly industrialized area of Mexico City, and San Lorenzo, a suburban area of the city. Although data regarding atmospheric pollution were not available, there is an acknowledged higher level of macroenvironmental air pollution in Xalostoc. Pulmonary function tests were performed on 468 children in San Lorenzo and 405 children in Xalostoc. No differences between residents of the two communities for acute or chronic respiratory conditions were detected by questionnaire. The pulmonary function data demonstrate that boys have larger forced vital capacities (FVC) and forced expiratory flows over the middle half of the FVC (FEF25-75) than girls. Slopes of regression lines for FVC but not for FEF25-75 are greater in boys and girls from Xalostoc than in boys and girls from San Lorenzo. This suggests that young children from Xalostoc may experience ill effects of air pollution but develop catch-up growth later. There were no important community or gender effects on slopes of regression lines for height and weight on age. In general, the regression lines for FVC and FEF25-75 were below regression lines reported for children of Mexican ancestry living at sea level.

Adolescent↗

Comparison of ThinPrep preparations with conventional cervicovaginal smears. Practical considerations.

This study compared cytologic quality, diagnostic accuracy, detection of endocervical and endometrial cells and yeast, screening times and costs for 128 ThinPrep preparations (TP) to the corresponding conventional cervicovaginal cytologic smears (CCVS). Final diagnoses agreed in 114 (89%) cases. There were four discrepancies between atypical squamous cells of undetermined significance and low grade squamous intraepithelial lesion. The number of abnormal cells was lower in TP than in CCVS. Endocervical and endometrial cells were detected less frequently in TP than in CCVS. Yeast forms were seen rarely but were identified in both CCVS and TP. Inflammation and blood were less prominent on TP. While some CCVS showed artifacts related to fixation, cell preservation was optimal in all TP. Screening times were significantly shorter for TP than for CCVS. The combined cost of reagents, preparation and screening for an average TP was $1.78 higher than for a CCVS. We conclude that the use of TP for cervicovaginal smears reduces screening time and produces better cytologic preparations. However, cost-benefit analyses, readjustments in criteria for diagnosis of dysplasia and improvements in the recovery of glandular cells may be necessary before this method is used instead of CCVS.

Adenocarcinoma↗