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The authors evaluated determinants of response to Internet-based surveys in a sample (n = 5600) of Texas healthcare professionals. Participants were given the option of responding by mail or over the Web (response, 66%). Internet respondents were younger (p < .001), had worked fewer years in healthcare (p < .001), and were more likely to be male (p < .001) and to work in a hospital (p = .007). Missing questionnaire items were significantly higher among Web responders with regard to age, sex, race, body mass index, and smoking (p < .001). In the final multivariate logistic regression, only male gender (odds ratio [OR] = 2.09, 95% CI = 1.56-2.80) and younger age remained significantly associated with response over the Internet. Age quartile and responding electronically were inversely associated. Taken together with a priori knowledge of the demographic and professional profile of a study population, these findings can be useful in planning and implementation of surveys among healthcare workers. [ABSTRACT FROM AUTHOR]

Presents a research describing employer compliance with pesticide safety training and field sanitation among migrant farm worker mothers from Starr County, Texas. Significance of safety standards to limit the exposure of farm workers to potentially hazardous agricultural pesticides; Areas covered by the pesticide safety training required by the Worker Protection Standard; Recommendation of increased enforcement and an alternate delivery of pesticide training despite low level of employer compliance to safety standards.

Objectives: Potential gains in life expectancy (PGLEs) that give proper consideration to competing risks are an effective indicator for measuring the impact of multiple causes of death on a defined population. This study aimed to assess PGLE by hypothetically reducing the major causes of death in the USA from 2001 to 2008. Study design: PGLEs due to the reduction and elimination of heart disease, cancer, Alzheimer's disease, kidney disease or human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) were calculated by age, gender and race. Methods: Age-specific mortality rates for the above diseases from the National Center for Health Statistics were used, and multiple decremental life tables were constructed to compute the corresponding PGLEs. Results: PGLEs due to the elimination of heart disease, cancer or HIV/AIDS decreased from 2001 to 2008, but PGLEs due to the elimination of Alzheimer's disease or kidney disease increased over time. For heart disease, PGLE in 2001-2008 for all races was 2.78-2.15 for females vs 2.41-2.06 for males. For cancer, PGLE in 2001-2008 for all races was 2.97-2.81 for females vs 3.02-2.85 for males. HIV/AIDS has a greater impact on people of working age, whereas Ahheimer's disease has a greater impact on the elderly population. To compare the impacts of these diseases on life expectancy, partial multiple decremental life tables were constructed, and PGLEs were computed by a partial reduction or complete elimination of various causes of death for the entire life span as well as for certain working ages. Conclusion: This study outlined a picture of how each category of diseases could affect life expectancy in the US population by age, race or sex. The findings may assist in evaluating current public health improvements, and also provide useful information for directing future research and disease control programmes. [ABSTRACT FROM AUTHOR]

SHOX2 is a homeobox transcription factor associated with atrial fibrillation (AF) and sinus node dysfunction. Here, we generated two homozygous SHOX2 knock-out hiPSC lines from a healthy control line and a corrected AF patient line (disease-specific SHOX2 mutation corrected to WT) using CRISPR/Cas9. These cell lines maintained pluripotency, an ability to differentiate into all three germlayers and a normal karyotype, presenting a valuable tool to investigate the impact of a full SHOX2 knock-out with respect to arrhythmogenic diseases on a cellular level., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Shoulder dysfunction is common in persons with spinal cord injury (SCI) with an incidence of up to 63%. Dysfunction is a result of muscle imbalances, specifically denervated rotator cuff muscles that are repetitively used during manual wheelchair propulsion., Objective: To determine which arm stroke technique, pump (P) or semicircular (SC), is most energy efficient for long periods of propulsion., Design: A randomized study with repeated measures observations., Setting: The study was performed at an institutional gait analysis laboratory., Participants: 18 able-bodied (AB) male participants were studied and randomized into one of 2 conditions, SC or P., Methods: Shoulder muscle fatigue was measured by changes in Borg CR10 Rate of Perceived Exertion (Borg RPE) and upper extremity strength via a handheld dynamometer. Participants were studied and assigned into one of 2 conditions of wheelchair arm propulsion patterns, SC or P group, and propelled on a wheelchair treadmill for 10 minutes., Main Outcome Measures: The primary outcomes included recordings of Borg RPE scale during continuous wheelchair propulsion and pre- and post-test dynamometer testing means for bilateral elbow and shoulder extension. Analysis of covariance, t-tests, and Kruskal-Wallis tests were used in analyzing data., Results: Although not significant (P = .23), the Borg RPE scores for the SC condition were consistently higher than the scores for the P condition. In addition, the dynamometer pre- and post-test readings demonstrated a larger decrease for the SC condition participants than for the P condition participants, but were not statistically significant., Conclusions: These data demonstrate that the SC wheelchair propulsion pattern appears to be more fatiguing to shoulder muscles than the P propulsion pattern. However, more data would need to be collected to find a significant difference., Level of Evidence: II., (Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.)

Complete uniparental isodisomy (iUPD)-the presence of two identical chromosomes in an individual that originate from only a single parental homolog-is an underestimated cause of recessive Mendelian disease in humans. Correctly identifying iUPD in an index patient is of enormous consequence to correctly counseling the family/couple, as the recurrence risk for siblings is reduced from 25% to usually <1%. In medium/large-scale NGS analyses, we found that complete iUPD can be rapidly and straightforwardly inferred from a singleton dataset (index patient only) through a simple chromosome- and genotype-filtering step in <1 min. We discuss the opportunities of iUPD detection in medium/large-scale NGS analyses by example of a case of CHRNG-associated multiple pterygium syndrome due to complete maternal iUPD. Using computer simulations for several detection thresholds, we validate and estimate sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of the proposed screening method for reliable detection of complete iUPD. When screening for complete iUPD, our models suggest that a >85% proportion of homozygous calls on a single chromosome with ≥30 sufficiently interspaced called variants results in a sensitivity of 97.9% and specificity of 99.7%. The PPV is 95.1%, the NPV 99.9%. When this threshold is exceeded for a chromosome on which a patient harbors an apparently homozygous disease-associated variant, it should be sufficient cause to discuss iUPD as a plausible or probable mechanism of disease in the genetic analysis report, even when parental segregation has not (yet) been performed.

In mammals, there is an underlying mechanism that dictates the organism's biological functions and daily activity schedule, known as circadian rhythms, which play a major role in maintaining steady metabolism, homeostasis, and immunity. Limited research has been done investigating the effects of continuous opiate administration on the circadian rhythm activity pattern. A change in circadian activity pattern is suggested as an experimental model to demonstrate long-term effect of the drug. The objective of this study was to investigate the effects of morphine treatment on the long term activity (24 h) of the animal as well as the activity after abrupt removal, since prescribed medication containing morphine is widely used and abused and its long term effects are not known. Male Sprague-Dawley rats were contained in stable conditions with a standard light/dark cycle recordings taken before, during and after morphine pellet implantation. Cosinor analysis was used to fit a 24-hour curve to the activity pattern. Results indicate that morphine pellet administration alters the mesor, amplitude, the day-time and night-time activity levels, and demonstrates a remarkable change in the maximal circadian rhythm timing during the withdrawal period. The question whether morphine changes the circadian rhythm or a change in circadian rhythm results in tolerance and withdrawal is discussed., (Published by Elsevier Inc.)

Background: Failure to include participants of diverse race and ethnicity (i.e. those other than European Caucasian, non-Hispanic) in clinical trials impedes the safe development of new therapies given the potential for racial/ethnicity-related variations in treatment response. Increasing diversity is problematic for low prevalence diseases, where most community-based approaches do not reach those with the disease., Purpose: Increase racial/ethnic diversity of participants in a Parkinson's disease therapeutic trial., Methods: We incorporated a randomized Ancillary Trial into the multisite National Institute of Neurologic Disorders and Stroke Exploratory Trials in Parkinson's Disease Long-Term Study 1. Movement disorders clinics already participating in long-term trial 1 were eligible and were the unit of randomization and analysis. At least 14% of adult residents over age 55 and living within 30 miles of the eligible site were from a diverse population, or there was a near-by zip code with a highly diverse population. Eligible sites also agreed to be randomized. The intervention was designed to increase community physicians' trust in long-term trial 1 investigators and address recruitment barriers in diverse populations. Primary outcomes included percentage of participants from diverse racial/ethnic groups enrolled in long-term trial 1, and qualitative findings from key informant interviews of the Ancillary Trial investigators and coordinators at the end of the trial., Results: The Ancillary Trial stopped early for lack of efficacy, conditional power less than 1%. The 17 intervention sites had 12.6% diverse participants compared to 15.6% in 15 control clinics; odds ratio 0.82 (95% confidence interval = 0.32-2.16). In key informant interviews, high enrollers of diverse participants reported more use of existing physician relationships, untargeted community outreach, and extensive efforts to overcome participants' barriers. Low enrollers reported more use of patients in their practices and placed more responsibility for low enrollment on prospective participants., Limitations: The Ancillary Trial included only those with Parkinson's disease. Whether our findings generalize to trials in other low prevalence diseases is unknown., Conclusions: Increasing diversity in Parkinson's disease clinical trials requires new paradigms for trial investigator and coordinator interactions with community physicians and prospective trial participants.

Circadian pattern of activity regulates many aspects of mammalian physiology and behavior to particular times of the day by entraining the circadian clocks to external environmental signals. Since circadian rhythms are sensitive to many pharmacological agents, it is important to understand if the repetitive use of psychostimulants such as amphetamine will alter the circadian rhythm behavioral activity pattern. The present study uses male Sprague-Dawley rats to study the long-term effects of amphetamine on the locomotor circadian rhythm activity pattern. Rats were randomly assigned to a testing cage that recorded their locomotor activity nonstop for eleven days using the open field assay, as follows: one day of baseline activity was recorded and then the experimental group was injected with amphetamine (0.6mg/kg) for 6days, no treatment for 3days (i.e., washout days) and then re-challenged with amphetamine for one more day while the control group was treated similarly with saline. The Cosine Curve Statistical Analysis (CCSA) test was used to fit a 24-hour curve to activity pattern. Results indicate that repetitive daily amphetamine injections cause behavioral sensitization and a significant change of circadian rhythm of locomotor activity pattern, and elicit behavioral expectation to receive the drug or expression of withdrawal during the washout days. The results suggest that either changes in circadian rhythm caused sensitization and withdrawal or sensitization and withdrawal caused the change in circadian rhythm activity., (Published by Elsevier B.V.)

To determine the risk of cardiotoxicities in association with trastuzumab with/without anthracycline-containing chemotherapy in a large nationwide population-based cohort of patients with breast cancer. We studied 47,806 women with breast cancer ages ≥ 65 in 1998-2005 from 16 cancer registries in the Surveillance, Epidemiology and End Results (SEER)-Medicare data and 16,092 cases matched with equal number of controls on the propensity of receiving chemotherapy or trastuzumab. Cumulative incidence of congestive heart failure in year-1 was 5.5% for patients receiving anthracycline and trastuzumab and 3.2% for those receiving anthracycline without trastuzumab. The cumulative incidence of congestive heart failure in year-5 was 15.5 and 9.1%, respectively. Compared to those without chemotherapy and trastuzumab, patients treated with anthracycline-containing chemotherapy and no trastuzumab were 19% significantly more likely to develop congestive heart failure (hazard ratio = 1.19, 95% CI = 1.05-1.34), whereas those receiving trastuzumab without anthracycline and those receiving both trastuzumab and anthracycline were 1.97 and 2.37 times more likely to develop congestive heart failure after adjusting for patient and tumor characteristics. Concurrent or sequential use of anthracycline and trastuzumab was associated with a greater risk of congestive heart failure and cardiomyopathy. Carefully monitoring cardiac functions in patients receiving anthracycline and trastuzumab is warranted.

Alcohol has many effects throughout the body. The effect on circadian rhythms and the correlation of these effects to withdrawal effects of alcohol present interesting findings. By measuring 3 planes of activity of female Sprague-Dawley rats during alcohol usage and continuing study through the first 2 days following withdrawal of alcohol allow for the observation of a drastic modulation of the circadian pattern of activity., (2010 Elsevier Inc. All rights reserved.)

There is little information on chemotherapy-induced peripheral neuropathy (PN) for community-dwelling patients with cancer. We studied 65,316 patients with breast cancer, 9242 with ovarian cancer, and 86,278 with non-small cell lung cancer from 1991 through 2002 identified from the 16 areas of Surveillance, Epidemiology and End Results. The incidence density of PN was 15.3, 21.5, and 18.3 per 1000 person-years for patients with breast, ovarian, and lung cancer who received platinum-taxane combination chemotherapy, respectively. Patients with breast, ovarian, and lung cancer receiving taxanes were more than twice as likely to develop PN compared with those not receiving chemotherapy (adjusted hazard ratio = 2.22, 95% confidence interval = 1.85-2.66 in patients with breast cancer), whereas patients who received platinum-taxane combination chemotherapy were more than 3 times as likely to develop PN compared with women who did not receive chemotherapy (adjusted hazard ratio = 3.33, 95% confidence interval = 2.05-5.05). In patients with ovarian or lung cancer receiving taxanes or platinum-taxane combination therapy, the risk of PN was increased with increasing number of chemotherapy cycles. These findings remained similar after adjusting for the history of preexisting PN or diabetes. Close monitoring for PN in patients receiving taxanes alone or in combination with platinum compounds may be warranted.

Background: Racial differences have been demonstrated in patients who receive treatment for colorectal cancer. However, little is known about whether these disparities have changed over time. The objective of this study was to determine whether racial disparities in receiving standard therapy have declined between 1991 and 2002., Methods: The study population consisted of 59,803 Caucasians and African Americans aged > or =65 years who were diagnosed with colorectal cancer (American Joint Committee on Cancer stages I, II, and III) between 1991 and 2002 and were identified from the Surveillance, Epidemiology, and End Results Program/Medicare-linked database. Standard therapy for colorectal cancer was defined based on the Physician Data Query guidelines from the National Cancer Institute. The crude and age- and sex-adjusted percentages and the odds ratios (ORs) of receiving standard therapy were reported., Results: From 1991 to 2002, the percentage of patients who did not receive standard therapy for colorectal cancer decreased for both Caucasians (from 24.5% to 22.4%) and African Americans (from 30.4% to 26.4%). Overall, African Americans were 16% less likely to receive standard therapy for colorectal cancer (OR, 0.84; 95% confidence interval [CI], 0.78-0.90) than Caucasians, but the difference was not significant after the analysis was adjusted for other factors (OR, 0.96; 95% CI, 0.88-1.05). The gap for not receiving standard therapy was relatively stable, peaked in 1997 (7.2%), and decreased from 1999 to 2002 (from 7.1% to 4%)., Conclusions: The percentage of patients receiving standard therapy for colorectal cancer increased over time, but disparities remained and decreased in recent years. Future studies should include other ethnic groups and should incorporate provider and system factors that may contribute to treatment disparities.

Background: Lead and copper are potentially toxic metals. The objective of our work was to test the water from the drinking fountains of a large public access office complex in southwest Houston, Texas, for the presence of lead, copper, and microbiologic contamination. The data for the water fountains were compared with what we found in the local municipal drinking water supplies., Methods: Samples were collected as the first draw at the beginning of the work week. These samples were acidified to prevent the precipitation of heavy metals and analyzed using United States Environmental Protection Agency (USEPA) approved procedures and quality control., Results: Traces of lead were detected in 37.5% and copper in 100% of the tested water fountains. In two buildings, concentrations in some fountains exceeded the USEPA action level for lead (by up to 12-fold) and for copper (by up to 3.9 fold). One sample was positive for total coliform and Escherichia coli bacteria. Comparison with samples from the local municipal drinking water supplies indicated that both metals and bacteria were the result of secondary contamination at the water fountain sites., Conclusions: This study showed that drinking water fountains can be an unexpected and unappreciated source of intake of metal and bacterial contaminants.

Background: To the authors' knowledge, few studies to date have addressed the patterns of how chemotherapy was administered (administration modes) over time. In the current study, the goal of the authors was to describe how chemotherapy for breast carcinoma was administered and to determine whether chemotherapy administration modes were associated with toxicity in a community-based large cohort., Methods: The authors studied 5256 women who were diagnosed with breast carcinoma at age 65 years or older between 1992-1999 and received chemotherapy. The patients were identified from the Surveillance, Epidemiology, and End Results (SEER)Program-Medicare linked databases. Chemotherapy drugs and modes of administration were determined through procedure codes in Medicare claims., Results: Of the 5256 patients who received chemotherapy, 33% received it through an intravenous infusion for less than 1 hour; 39% through an intravenous infusion lasting 1-8 hours; 15% through an intravenous infusion lasting longer than 8 hours and requiring a pump; 12% through an intravenous push technique; and 1% through a subcutaneous, intramuscular, or intralesional injection. These modes varied substantially across the 11 SEER areas. The risks of hospitalization for chemotherapy-related toxicities (neutropenia, fever, thrombocytopenia, and adverse effects of systemic therapy) were not found to be significantly associated with different modes of chemotherapy after adjusting for other factors. Compared with patients receiving 5-flurouracil using an intravenous infusion for longer than 8 hours, the risk of toxicity was determined to be 0.96 (95% confidence interval [95% CI], 0.63-1.47) for patients treated with an intravenous infusion lasting 1-8 hours; 0.94 (95% CI, 0.62-1.41) for patients treated with an intravenous infusion lasting less than 1 hour; and 0.66 (95% CI, 0.38-1.08) for patients treated with subcutaneous, intramuscular, or intralesional injection or an intravenous push technique., Conclusions: There were substantial geographic variations noted in the modes of administering chemotherapy; however, these variations did not appear to be associated with the risk of toxicities (neutropenia, fever, thrombocytopenia, and adverse effects of systemic therapy).

A total of 2,828,068 State of Texas singleton conceptions, estimated from the date of the first day of the last menstrual period, were assessed for annual periodicity by multiple-component (1-yr fundamental plus the 6- and 3-month harmonics) Cosinor analysis. An annual pattern (p < 0.001) of conception was detected with a December peak, end of July-beginning of August trough and modest amplitude (total peak-to-trough variation) equal to 13.3% of the yearly mean. Annual patterns (p < 0.005) of generally comparable peak and trough times were also documented for conceptions categorized by maternal marital status, age, ethnicity, years of education, birthplace, and county (Texas-Mexico border vs. non-border) of residence. The amplitude, a measure of the prominence of the annual pattern, varied by race (two-fold greater for non-Hispanic Blacks and Hispanics than non-Hispanic Whites), age (50-60% greater for the 19-year-old and younger group than the 20-29 and 30-44-year-old groups) and maternal education (two-fold greater for those with 0-8 than 13 or more years of schooling). Annual patterns (p < 0.001) in conceptions, generally with December peak and end of July-beginning of August trough, were also detected for neonatal variables categorized by birth weight, birth order, gestational age, and gender. The amplitude of the annual pattern in conceptions varied directly with gestational age and inversely with birth weight class.

Background: Migrant and seasonal farmworkers have a high potential for pesticide exposures, yet are rarely included in epidemiologic studies. This study examined the feasibility of assessing prenatal exposures to pesticides and other compounds in pregnant Hispanic farmworkers., Methods: Nine women completed a survey about work experiences during pregnancy. Maternal urine, cord blood, and placenta samples were obtained at delivery for analysis of 51 analytes, including 6 phenoxy acid or triazine herbicides, 21 organochlorine insecticides, 10 PCBs, and 14 volatile organic compounds., Results: Seven of 51 analytes were found in the biological samples. DDE, DDT, dichlorbenzene, toluene, trimethylbenzene, and endosulfan sulfate were detected in cord blood samples, and 2,4-D in urine from one or more women., Conclusions: We documented the feasibility of following farmworkers to assess in utero exposure to pesticides and other contaminants, and demonstrated exposure to these compounds. Difficulties in measuring pesticides with short half lives were noted., (Copyright 2001 Wiley-Liss, Inc.)

Background: Specialized methods are necessary to collect data from migrant farmworkers for epidemiologic research., Methods: We developed a questionnaire that collected lifetime occupational histories and other lifestyle risk factors via a life events/icon calendar, and administered the questionnaire to a convenience sample of 162 migrant farmworkers in nine areas of the U.S., Results: The average duration of the interviews was about 1 h 30 min, with an average of 45 min for the work history section. The occupational histories covered a median of 27.6 years per person for men and 20.8 years per person for women. The median number of years spent in farm jobs was 11.3 for men and 5.8 for women. The median number of farm jobs (crop/task combination) per person was 59 among men and 27 among women. Many farmworkers performed the same crop/task combinations at multiple times throughout their lives, yielding a median of 13 unique farm jobs and 8 unique crops among men and 7 jobs and 5 crops among women., Conclusions: The project demonstrated that it is feasible to collect detailed work histories and other risk factor data from farmworkers, documented the complexity of work histories encountered among farmworkers, and yielded recommendations for refining a questionnaire that will facilitate future epidemiologic research on farmworkers., (Copyright 2001 Wiley-Liss, Inc.)

Background: In response to The National Cancer Institute (NCI) concerns about the ability to conduct studies among migrant farmworkers, this study evaluated the feasibility of identifying migrant farmworkers in their home state and tracing them over an extended period of time., Methods: In 1995, a group of 196 persons who had classified themselves as "migrant farmworkers" in two earlier chronic disease studies was identified. The primary objective of the current study was to determine the proportion of these farmworkers who could be located in 1995-1996., Results: Of these farmworkers, 163 were located and were living (83.2%), 15 had died (7.6%), and 18 (9.2%) were lost to follow-up., Conclusions: The excellent follow-up rate was due in part to the high participation rates among persons contacted for information, stability of the farmworkers' permanent homes, predictable timing of migration, and a longstanding health research program with established community contacts., (Copyright 2001 Wiley-Liss, Inc.)

Sick Building Syndrome remains a prevalent problem with patient complaints similar to typical allergy symptoms. Unlike household allergens typically found in domestic reservoirs, the allergen from a common fungus like Aspergillus fumigatus (i.e., Asp f 1) is conceivably widespread in the work environment. This project surveyed airborne levels of the Asp f 1 allergen in office and non-industrial occupational environments, as well as the dust reservoirs of A. fumigatus believed to be responsible for those levels. Airborne and bulk dust samples were collected, extracted, and assayed for Asp f 1. Concurrently, bulk dusts collected from the same locations were selectively cultured for A. fumigatus, and mesophilic fungi and bacteria. Samples were collected during both wet and dry climatological conditions from paired wet and dry building locations to examine the possibility of Asp f 1 increases due to fungal growth blooms. Very low levels of Asp f 1 were detected but only in the airborne samples (2/120 positive samples, with 3.6 ng/m3 and 1.8 ng/m3; LOD < 1.2 ng/m3). No dust samples showed even detectable traces of the allergen (LOD = 5 ng/g dust). Although A. fumigatus counts from dusts fluctuated significantly with exterior moisture events, analysis of wet versus dry period samples showed no differences in Asp f 1 levels. These results indicate that even in the presence of measurable fungal concentrations, background levels of Asp f 1 are low. Nonindustrial office buildings devoid of indoor air quality issues were not observed to have significant levels of the Asp f 1 allergen in the geographical region studied.

The identification of host factors that are predictors of changes in serum polyhalogenated biphenyl contaminants over time has been a difficult challenge in epidemiologic studies of exposed individuals. Of particular concern are age at exposure, reproductive and lactational histories, and changes in body mass index. Using both cross-sectional and longitudinal approaches, this study examined factors related to high initial serum PBB and PCB levels and changes in these levels over time among women of varying ages at exposure (n=1772; age range<1 to 45 years). In 1973, PBB exposure occurred through consumption of farm products contaminated with PBB added to cattle feed. Exposures to PCBs began in 1941 through PCB-contaminated silo sealant deteriorating into animal feed. The Michigan Department of Public Health began enrolling participants in 1977 and has continued to follow them through annual updates. At enrollment, questionnaires were administered to obtain demographic, lifestyle, and anthropometric measurements, medical/reproductive and occupational histories, and contaminated food consumption patterns. Blood samples were collected for PBB and PCB analysis at enrollment for all participants; additional serum tests were done on a subset of the population during follow-up. Median serum levels at enrollment were 2.0 ppb PBB and 5.0 ppb PCB. A decline in serum PBB level over an interval that ranged from 1 to 146 months (median=31) was observed for 44.6% of the women (median=1.0 ppb), while 12.2% showed an increase (median=1.0 ppb). PCB levels declined in 50.3% of the women (median=3.0 ppb) while 12.2% increased (median=2.0 ppb). Relative to women whose contaminant levels were stable, higher initial serum level was a predictor of decline for both PBB and PCB (OR=1.66, 95% CI 1.52-1.82; OR=3.26, 95% CI 2.58-4.12, respectively); a yearly increase in interval between tests was related to declining PCBs (OR=1.65, 95% CI 1.46-1.87). In addition, age< or =10 years at exposure (OR=1.72, 95% CI 1.03-2.86) and residence on a quarantined farm (OR=1.40, 95- CI 1.03-1.90) were predictors of a decrease in PBBs. Factors related to an increase in PBB levels were age< or =10 years at exposure (OR=0.30, 95% CI 0.10-0.96) and initial PBB level (OR=1.24, 95% CI 1.15-1.33); and for PCBs, high initial level (OR=1.34, 95% CI 1.17-1.53) and body mass index (OR=1.07, 95% CI 1.01-1.13). One or more live births during the interval between tests were not related to changing levels of either contaminant; breastfeeding data were not available for examination. Early age at exposure appears to be an important predictor of changes in serum PBB levels over time., (Copyright 2001 Academic Press.)

In response to growing concern for occupational health and safety in the public hospital system in Costa Rica, a cross-sectional survey of 1,000 hospital-based health care workers was conducted in 1997 to collect baseline data that are being used to develop worker training programs in occupational health in Costa Rica. The objectives of this survey were to: 1) describe the safety climate within the national hospital system, 2) identify factors associated with safety, and 3) evaluate the relationship between safety climate and workplace injuries and safety practices of employees. The safety climate was found to be very poor. The two most significant predictors of safety climate were training and administrative support for safety. Safety climate was a statistically significant predictor of workplace injuries and safety practices, respectively, and there was an underreporting rate of 71% of workplace injuries. These findings underscore the need for improvement of the safety climate in the public hospital system in Costa Rica.

The purpose of this study was to determine whether the occurrence of accidental blood-borne pathogen exposure incidents in medical students and residents in training varies during the 24 h. A retrospective review of reported exposures was conducted in a large urban teaching institution--the University of Texas Health Science Center in Houston--between November 1993 and July 1998. Professional level (year of student or level of resident), time of exposure, means/route of exposure (needle stick, laceration, or splash), and type of medical service were recorded. Analysis of the clock time of the 745 reported blood-borne pathogen exposures showed they occurred more frequently during the day than night. Over the nearly 5-year span, 531 incidents took place between 06:00 and 17:59 in comparison to only 214 between 18:00 and 05:59. To account for the day-night difference in medical student and resident hospital staffing, the data were reexpressed as exposure rates, that is, in terms of the number of events per hour per 1000 medical students and residents. Based on the total number of reported exposures over the almost 5-year span of data collection, the average rate was 40 accidents per hour per 1000 doctors in training during the 12 h daytime span (6:00-17:59). It was 50% greater at night (18:00-05:59), with 60 incidents per hour per 1000 doctors in training. The day-night difference in rate of exposures was statistically significant (p < .04). The relative risk ratio for residents and students when working during the day shift compared to working the night shift was 0.67. This means that doctors in training are at a 1.50 higher risk of sustaining a blood-borne pathogen exposure when working nights than when working days.

Background: A comprehensive surveillance system for occupational injuries to adolescents does not exist in Texas, as in most states. Therefore, the magnitude, severity, nature, and source of injuries to working adolescents have not been well described in Texas., Methods: The investigators used three data sources to investigate work-related injuries and deaths in Texas: (1) Texas Workers' Compensation Commission (TWCC) claims data from 1991 through April 1996; (2) 1993 TWCC/Bureau of Labor Statistics (BLS) Annual Survey of Occupational Injuries and Illnesses; and (3) work-related fatalities identified from Texas death certificates from 1990-1995., Results: There were 9,027 injuries reported to the TWCC for adolescents 14-17 years of age during slightly more than 5 years. Injuries for which indemnity payments were made (more than 7 days out of work) occurred among 21.7% of the adolescents. Based on BLS data in 1993, of 992 non-fatal injuries involving days away from work, 35% were caused by contact with objects, 27% by bodily reaction, and 24% by falls. Two-thirds of these injuries occurred while working in eating and drinking places and grocery stores. Three-quarters of the 30 deaths from 1990-1995 were accounted for equally by motor vehicle and homicide., Conclusions: In conclusion, a substantial number of adolescents are injured or killed in the workplace each year in Texas. Although improved population-based surveillance is needed, sufficient knowledge exists to begin prevention efforts now.

The long-term health effects of human exposure to polybrominated biphenyls are not known. In this nested case-control study, we evaluated the association between site-specific cancer risk and serum polybrominated biphenyl levels among a Michigan cohort accidentally exposed to polybrominated biphenyls in 1973. The Michigan Department of Public Health has followed 3,899 people through 1993, among whom 195 primary cancers were identified in 187 persons. Controls were 696 randomly selected cancer-free individuals who were frequency matched to cases by sex and age (in 5-year strata). Baseline serum polybrominated biphenyl levels were measured using standard methods. We found an increasing dose-response relation for digestive system cancer risk with higher serum polybrominated biphenyl category [4-20 parts per billion (ppb), 21-50 ppb, and > 50 ppb] after adjustment for age, family cancer history, cigarette smoking, alcohol drinking, and baseline serum polychlorinated biphenyl level. Adjusted odds ratios (ORs) for each category were 8.23 [95% confidence interval (CI) = 1.27-53.3], 12.3 (95% CI = 0.80-191), and 22.9 (95% CI = 1.34-392), respectively. Univariate analysis for polybrominated biphenyl level and lymphoma risk also showed a dose-response relation, with corresponding ORs of 3.24 (95% CI = 0.24-95.9), 20.5 (95% CI = 1.51-608), and 32.6 (95% CI = 3.33-861).

A method is presented which links on-site electromagnetic field monitoring data with pre-existing work history data. The linkage is used to estimate cumulative and average annualized magnetic field exposure for a case-control study. On-site electromagnetic field monitoring data for 1,966 volunteer utility employees, at 59 sites in the United States and three other countries, were obtained from a large project (the EMDEX project) designed to collect, analyze, and document 60-Hz electric and magnetic field exposures for a diverse population. These data represent 9 primary work environments, and 16 job classification categories, amounting to 144 unique job categories which were consolidated using the job-exposure matrix presented into 282 three-digit Dictionary of Occupational Title (DOT) codes. The DOT code categories were then linked to lifetime occupational histories from a case-control study of leukemia. The method may be extended to link additional job titles with monitoring information. Job titles linked with electromagnetic field monitoring information provide more specific estimates of exposure intensity than previous ordinal estimates of exposure. Therefore, estimates of cumulative electromagnetic field exposure are achievable, as well as high and low level exposure estimates.

This study assessed the risk of cancer mortality and incidence among 2559 employees exposed to acrylonitrile in the production of Orlon at 2 plants in 1944-1991. Latency, duration of exposure, highest level of exposure ever experienced, and cumulative exposure were used as indicators of exposure. The average duration of exposure for the workers was 7.6 years with an average cumulative exposure of 57.6 ppm-years. Overall mortality was lower than expected in a comparison with the United States population and all DuPont employees [454 deaths, standardized mortality ratios (SMR) of 69 and 91, respectively)]. All the cancer death ratios were lower than expected in a similar comparison. The SMR values for specific sites did not differ significantly from the expected values. Mortality from all cancers and from prostate, respiratory, and digestive cancer did not show any significantly associated increases or a consistent pattern suggestive of a dose-response. The cancer morbidity patterns were similarly unremarkable.

Epidemiologic historical cohort studies of petroleum refinery and chemical manufacturing workers in Texas were reviewed to examine their cancer mortality in comparison to the U.S. and to assess the possible impact of cancer mortality among these workers on the State of Texas as a whole. Summary standardized mortality ratios and 95% confidence intervals were calculated for 20 cancer types, taking into account the heterogeneity of individual studies. There were 4314 cancer deaths among the 92,318 workers employed in 10 independent plant populations. Overall, there was a significant deficit in cancer mortality among petrochemical workers compared with the general U.S. population (SMR = 88, 95% CI = 80 to 96). Only the summary SMRs for brain cancer (SMR = 113, 95% CI = 96 to 133) and leukemias (SMR = 112, 95% CI = 94 to 130) approached statistical significance. Lung and liver cancer mortality excesses, noted for Texas as a whole, were decreased in these workers. Additional follow-up of these cohorts, their expansion to include minority and female workers, and additional study of possible occupational contributions to leukemia and brain cancer are recommended.

An autopsy study was conducted to investigate whether there is transplacental transfer of asbestos in humans. The asbestos burden of lung, liver, skeletal muscle, and placenta digests of 40 stillborn infants was determined using a bleach digestion method. The fibers detected in the tissue digests were characterized as to the type of asbestos, using electron microscopy, energy-dispersive x-ray analysis, and selected-area diffraction analysis. Placental digests of 45 full-term, liveborn infants were similarly processed as controls. Low levels of small, thin, uncoated asbestos fibers were detected in the placentas and organs of 37.5% of the stillborn infants (15 of 40). The fiber sizes ranged from 0.05 to 5.0 microns in length and 0.03 to 0.3 micron in width, with a mean length of 1.15 microns and a mean width of 0.069 micron. Maximum numbers of fibers were found in the lungs (mean 235,400 fibers/g; n = 10), followed by liver (mean 212,833 fibers/g; n = 6), placenta (mean 164,500 fibers/g; n = 4), and skeletal muscle (80,000 fibers/g; n = 1). The fibers were detected at all stages of gestation and showed no association with gestational age. A significant association was found between fiber presence and working mothers, and positive but nonsignificant associations were found with maternal history of drug abuse, previous abortions, and fetal maceration. No association was found between premature rupture of membranes and fiber presence. No fibers were detected in the 45 placentas of the liveborn control infants. There was a highly significant difference in the asbestos fiber counts of the placentas of the stillborn and liveborn infants (P < .001). Our studies demonstrate the presence of short and thin asbestos fibers in stillborn infants and their positive association with working mothers.