Faculty Bibliography

OBJECTIVES/OBJECTIVE:To review James Jackson's analysis of bloodletting among pneumonitis patients at the newly founded Massachusetts General Hospital, in which he implemented the numerical method advocated by Pierre-Charles-Alexandre Louis. STUDY DESIGN AND SETTING/METHODS:The study sample included 34 cases of clinically diagnosed pneumonitis admitted to Massachusetts General Hospital between April 19, 1825, and May 10, 1835, and discharged alive. Patient data were extracted from meticulously kept case books. Jackson calculated mean number of venesections, ounces of blood taken, and days of convalescence within groups stratified by day of the disease when first bloodletting occurred. He also calculated average convalescence within groups stratified by age, sex, prior health, vesication, and day of the disease when the patients were admitted to the hospital. RESULTS:To Jackson's surprise, it "seemed to be of less importance, whether our patients were bled or not, than whether they entered the hospital early or late" after the onset of the pneumonitis. Bloodletting was ineffective. Our multivariate reanalysis of his data confirms his conclusion. Outstandingly for his time, Jackson ruled out unwarranted effects of covariates by tabulating their numerical relations to the duration of pneumonia. CONCLUSION/CONCLUSIONS:Using novel gathering of patient clinical data from hospital records and quantitative analytical methods, Jackson contributed results that challenged conventional wisdom and bridged French therapeutic epistemology and American medical pragmatism.

BACKGROUND:Although maternal hypothyroidism increases the risk of adverse neonatal and obstetric outcomes as well as lower IQ in children, the environmental determinants of maternal thyroid dysfunction have yet to be fully explored. OBJECTIVES/OBJECTIVE:We aimed to examine associations between mid-pregnancy blood lead (BPb) and concomitant measures of thyroid function among participants in the Yugoslavia Prospective Study of Environmental Lead Exposure. METHODS:As part of a population-based prospective study of two towns in Kosovo-one with high levels of environmental lead and one with low-women were recruited during the second trimester of pregnancy, at which time blood samples and questionnaire data were collected. We measured concentrations of BPb, free thyroxine (FT4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibodies (TPOAb) in archived serum samples. RESULTS:Compared with women from the unexposed town, women from the exposed town had lower mean FT4 (0.91 ± 0.17 vs. 1.03 ± 0.16 ng/dL), higher mean TPOAb (15.45 ± 33.08 vs. 5.12 ± 6.38 IU/mL), and higher mean BPb (20.00 ± 6.99 vs. 5.57 ± 2.01 μg/dL). No differences in TSH levels were found. After adjustment for potential confounders, for each natural log unit increase in BPb, FT4 decreased by 0.074 ng/dL (95% CI: -0.10, -0.046 ng/dL), and the odds ratio for testing positive to TPOAb was 2.41 (95% CI: 1.53, 3.82). We found no association between BPb and TSH. CONCLUSIONS:Prolonged lead exposure may contribute to maternal thyroid dysfunction by stimulating autoimmunity to the thyroid gland.

OBJECTIVE:To evaluate associations between work-related stress, stressful life events, and perceived stress and semen quality. DESIGN/METHODS:Cross-sectional analysis. SETTING/METHODS:Northern California. PATIENT(S)/METHODS:193 men from the Child Health and Development Studies evaluated between 2005-2008. INTERVENTION(S)/METHODS:None. MAIN OUTCOME MEASURE(S)/METHODS:Measures of stress including job strain, perceived stress, and stressful life events; outcome measures of sperm concentration, percentage of motile sperm, and percentage of morphologically normal sperm. RESULT(S)/RESULTS:We found an inverse association between perceived stress score and sperm concentration (estimated coefficient b=-0.09×10(3)/mL; 95% confidence interval [CI]=-0.18, -0.01), motility (b=-0.39; 95% CI=-0.79, 0.01), and morphology (b=-0.14; 95% CI, -0.25, -0.04) in covariate-adjusted linear regression analyses. Men who experienced two or more stressful life events in the past year compared with no stressful events had a lower percentage of motile sperm (b=-8.22; 95% CI, -14.31, -2.13) and a lower percentage of morphologically normal sperm (b=-1.66; 95% CI, -3.35, 0.03) but a similar sperm concentration. Job strain was not associated with semen parameters. CONCLUSION(S)/CONCLUSIONS:In this first study to examine all three domains of stress, perceived stress and stressful life events but not work-related stress were associated with semen quality.

Prenatal exposure to chlorpyrifos (CPF), an organophosphorus insecticide, has long been associated with delayed neurocognitive development and most recently with decrements in working memory at age 7. In the current paper, we expanded the previous work on CPF to investigate how additional biological and social environmental factors might create or explain differential neurodevelopmental susceptibility, focusing on main and moderating effects of the quality of the home environment (HOME) and child sex. We evaluate how the quality of the home environment (specifically, parental nurturance and environmental stimulation) and child sex interact with the adverse effects of prenatal CPF exposure on working memory at child age 7years. We did not observe a remediating effect of a high quality home environment (either parental nurturance or environmental stimulation) on the adverse effects of prenatal CPF exposure on working memory. However, we detected a borderline significant interaction between prenatal exposure to CPF and child sex (B (95% CI) for interaction term=-1.714 (-3.753 to 0.326)) suggesting males experience a greater decrement in working memory than females following prenatal CPF exposure. In addition, we detected a borderline interaction between parental nurturance and child sex (B (95% CI) for interaction term=1.490 (-0.518 to 3.499)) suggesting that, in terms of working memory, males benefit more from a nurturing environment than females. To our knowledge, this is the first investigation into factors that may inform an intervention strategy to reduce or reverse the cognitive deficits resulting from prenatal CPF exposure.