Mucinous cystadenoma in the lung of a captive-born moustached tamarin (Saguinus mystax).

A 2-year-old, captive-born, male moustached tamarin was subjected to necropsy examination after a fatal head trauma. A solitary, circumscribed, subpleural mass (0.6 cm diameter) was found in the right caudal lung lobe. The mass was diagnosed as a mucinous cystadenoma. Histochemical and immunohistochemical tests were performed to further characterize the tumour. Surfactant proteins A, B, C and D were not found in the neoplastic cells, suggesting that the tumour arose from a non-surfactant-producing alveolar lining cell. Pulmonary mucinous cystadenomas are uncommon benign tumours in man and have not been reported previously in animals.

Spontaneous pulmonary alveolar proteinosis in captive "moustached tamarins" (Saguinus mystax).

Pulmonary alveolar proteinosis is a rare human disease characterized by accumulation of surfactant in alveoli without generating an inflammatory response. Lung lesions resembling pulmonary alveolar proteinosis were observed in 7 adult tamarins (5 males and 2 females). Gross lesions were characterized by areas of discoloration, slight bulging over the lung parenchyma, and occasional consolidation. Histologic examination of tamarin lung samples revealed intra-alveolar accumulation of amorphous, amphophilic, periodic acid-Schiff-positive, finely granular to dense material. In some cases, type II pneumocyte hypertrophy and hyperplasia were observed with pleural and septal thickening and fibrosis. Large numbers of intra-alveolar foamy macrophages were noted surrounding and/or in the vicinity of the lesions. Immunohistochemical analysis of the lung lesions using polyclonal (surfactant proteins A, B, and C) and monoclonal (surfactant protein D) antibodies revealed the granular material to be composed largely of surfactant protein B, followed by surfactant protein A. Surfactant proteins C and D were present in lesser quantities, with the latter observed surrounding the lipoproteinaceous deposits. Transmission electron microscopy of the affected lungs showed numerous, irregularly shaped osmiophilic lamellar bodies in type II pneumocytes. The cytoplasm in alveolar macrophages was expanded, containing ingested surfactant with swollen mitochondria and rough endoplasmic reticulum. Thoracic radiographs, available in 1 animal, depicted the lesions as small multifocal opacities randomly distributed in cranial and diaphragmatic lung lobes. This is, to the authors' knowledge, the first report of spontaneous pulmonary alveolar proteinosis in nonhuman primates.

Attributable risk of alcohol and other drugs for crashes in the transit industry.

OBJECTIVE: To estimate the impact of employee alcohol and drug use on crashes in the transit industry from 1995-2000. DESIGN: Secondary analysis of federally mandated post crash and random alcohol and drug testing results. SETTING: The US transit industry. SUBJECTS: Transit industry employees. MAIN OUTCOME MEASURES: Relative risk (RR), population attributable risk (PAR), and population attributable risk percentage (PAR%). RESULTS: For alcohol testing, the estimated PAR% ranged from 0.02% (1999) to 0.03% (1995). For drug testing, the estimated PAR% ranged from 0.38% (1998) to 0.67% (1997). Based on these calculations, the estimated number of crashes per 1000 crashes attributable to alcohol was less than one during 1995-2000, and the number attributable to drugs ranged from about four to about six. The number of crashes attributable to either alcohol or drugs did not vary greatly from 1995-2000. Estimated rates of crashes attributable to alcohol or drugs were substantially lower in 1995, the first year of testing, than had been projected based on previous estimates, and did not show substantial change from 1995-2000. CONCLUSIONS: Approaches to transit safety based on reducing employee use of alcohol and other drugs have modest potential for reducing number of fatalities, injuries, and crashes.

Anger expression and hypertension in transit workers.

One hypothesis in the literature on anger and hypertension is that a chronic tendency to suppress anger is an etiological factor in the development of hypertension. The present study assessed the relationship between anger expression and hypertension in a multicultural sample of 1,407 San Francisco bus drivers. Simple and multiple regression analyses revealed no significant differences between suppressed or expressed anger and hypertension. Thus, the results of this study do not support the hypothesis that suppressed anger is an etiological factor in hypertension.

Limiting comorbid conditions and breast cancer stage at diagnosis.

BACKGROUND: Contrasting hypotheses exist regarding the relationship between comorbidity and breast cancer stage at diagnosis. One suggestion is that disabling comorbid conditions would result in a later stage diagnosis of breast cancer because such conditions would limit mobility and thus access to medical care. This article examines this hypothesis by building a comorbidity summary measure of functionally limiting comorbid conditions and by testing the effectiveness of this measure in predicting the stage at which breast cancer is diagnosed. METHODS: Cases with newly diagnosed breast cancer were identified through the population-based Metropolitan Detroit Cancer Surveillance System, a participant of the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. Of 1191 eligible cases, 1011 (85%) were interviewed 2-4 months following diagnosis. The analyses for this study were limited to 731 cases for which there were complete data on all variables. Five individual comorbid conditions that predicted functional limitation were combined into a comorbidity summary measure: arthritis, eye conditions, gastrointestinal conditions, kidney conditions, and respiratory conditions. Breast cancer stage was categorized in relation to whether women had local or advanced (regional or remote) disease. RESULTS: Women with two or more of these five functionally limiting conditions were about half as likely as those with none of these conditions to receive an advanced stage diagnosis of breast cancer (odds ratio [OR] = 0.49, 95% confidence interval [CI] 0.28-0.86, p = .01). CONCLUSIONS: These findings do not support the suggestion that the presence of disabling comorbid conditions results in later stage breast cancer. The five conditions summarized by this measure, although functionally limiting, may also require greater medical monitoring due to associated symptoms and/or treatment requirements and thus lead to increased opportunities for cancer screening.

Injuries in child care centers: gender-environment interactions.

OBJECTIVES: To examine child characteristics (age, gender) and child care center environments (socioemotional quality, physical safety) that jointly predict injuries for preschool children. METHODS: A two year prospective study of 360 preschool children, ages 2-6 years, was conducted in four urban child care centers. Composite scores for center quality and physical safety were derived from on-site observations, and injury rates were based on teacher reports. Poisson regression analyses examined age, gender, center quality, center safety, and the interactions of gender with quality and safety as predictors of injury incidence over one child year. RESULTS: Age was significantly associated with injury rates, with younger children sustaining higher rates. An interaction between gender and center quality also significantly predicted injury incidence: girls in low quality centers experienced more injuries, while girls in high quality centers sustained fewer injuries than their male peers. Finally, an interaction between gender and center safety showed that girls in high safety centers sustained more injuries than boys, while girls in low safety centers sustained fewer injuries. CONCLUSIONS: Injuries occur even in relatively safe environments, suggesting that in child care settings, the socioemotional context may contribute, along with physical safety, to the incidence of injury events. Further, gender specific differences in susceptibility to environmental influences may also affect children's vulnerability and risks of injuries. The prevention of injuries among preschool children may thus require attention to and modifications of both the physical and socioemotional environments of child care.

Occupational stress factors and alcohol-related behavior in urban transit operators.

BACKGROUND: If alcohol consumption mitigates psychological and physiological aspects of the response to stressors, then alcohol consumption might be elevated for individuals exposed to high occupational stressors. Frequency of work stressors and reaction to those stressors were studied in relation to several alcohol-related outcomes. METHODS: During the period 1993-1995, 1979 transit operators underwent medical examinations for commercial driver's license renewal. Questionnaire and interview data concerning occupational stress factors and alcohol-related outcomes were available for 1386 (70.2%) of the operators. RESULTS: A positive association was found between the two job stressor-related measures and each of six alcohol-related outcomes. Of these 12 associations, ten were statistically significant. Individuals experiencing high self-reported frequency of job stressors and a higher perceived severity of those job stressors were more likely to drink and more likely to be heavy drinkers. They reported more consequences of alcohol consumption, reported increased consumption since beginning work as transit drivers, and were more likely to report drinking to deal with work stress. They also drank more, but this effect was not significant for either job stress measure. There was virtually no association between either stressor-related measure and alcohol dependency (CAGE). CONCLUSIONS: Together with other published findings, these results suggest increased alcohol-related outcomes in the presence of work stressors. This conclusion has potential implications for worksite health promotion and job design. Because our findings are cross-sectional, further research is needed to clarify the causal nature of the work stressor-alcohol association. Further research also is needed to clarify the role of individual differences and context.

Racial discrimination and alcohol-related behavior in urban transit operators: findings from the San Francisco Muni Health and Safety Study.

OBJECTIVE: A growing body of literature is documenting the health effects of racial discrimination. The authors investigated the association between racial discrimination and alcohol-related behavior in a sample of urban transit operators. METHODS: Using data from a 1993-1995 cross-sectional study of transit operators in San Francisco, California, the authors analyzed responses to two sets of questions about racial discrimination; the first set focused on reaction to unfair treatment and the second on arenas, or domains, of discrimination. Alcohol-related variables were: number of drinks per month, heavy drinking, alcohol dependence, and negative consequences of alcohol consumption. RESULTS: Operators who reported five or more domains of discrimination drank an average of 13.4 more drinks per month than those who reported no domains of discrimination (P = 0.01). Similarly, they were more likely to be heavy drinkers (adjusted odds ratio [OR] = 2.16; 95% confidence interval [CI] 1.14, 4.09) and dependent on alcohol (adjusted OR = 2.02; 95% CI 1.08, 3.79) than operators who reported no domains of discrimination. The number of domains in which operators reported having experienced discrimination was not related to sex, age, household income, job seniority, or marital status, but varied significantly by educational level and race/ethnicity. CONCLUSIONS: Data from a sample of urban transit operators showed an association between the number of domains of discrimination and some alcohol-related outcomes, but not others.

The epidemiology of injuries in 4 child care centers.

OBJECTIVES: (1) To describe the pattern of injury in preschool-aged children in 4 child care centers as compared with the results of other studies; (2) to compare injury rates by sex, age, and child care center; and (3) to examine environmental and child factors contributing to injury severity. DESIGN: A 2-year cohort study of 362 preschool-aged children attending 4 urban child care centers. Teachers completed standardized injury forms on the type of injury, body location, site of injury, and contributing factors. RESULTS: During the 2 years of the study, 1886 injuries were reported. The mean and median child injury rate was 6 and 4 injuries per 2000 exposure hours (equivalent to 1 full-time child care year), respectively. The majority of injuries (87%) were minor, occurred during free play (81%) and on the playground (74%), and were precipitated by child-related factors (59%), such as being pushed. Boys had significantly higher median injury rates than girls. Age-adjusted injury rates for each child care center were significantly different by center (F3 = 61, P<.001). While moderate to severe injuries were more often precipitated by combinations of child and environmental factors (chi2(4) = 20, P<.001), minor injuries were usually precipitated by child-related factors. CONCLUSIONS: Injury data from child care centers are important for identifying common risk factors for frequent or severe injury events and for designing injury prevention programs. More research is needed to identify factors contributing to injuries, such as children's behavior and the child care centers' physical and socioemotional environments.

Workplace discrimination and alcohol consumption: findings from the San Francisco Muni Health and Safety Study.

OBJECTIVE: There is evidence of an association between occupational stress and alcohol consumption. This study investigates the association between workplace racial discrimination and alcohol consumption in a sample of urban transit operators. METHODS: During 1993-1995, after undergoing a medical exam, 1,542 transit operators completed an interview. Depending on the outcome, we used logistic or linear regression models to examine the cross-sectional relationship between discrimination experience and alcohol consumption. RESULTS: Operators who reported discrimination in at least one situation, out of a possible four, were more likely to have had negative life consequences as a result of drinking (adjusted OR = 1.97; 95% CI, 1.20-3.83) and were more likely to be classified as having an alcohol disorder (OR = 1.56 [0.96-2.54]), compared to those who reported no instances of workplace discrimination. Results adjusted simultaneously for age, sex, race/ethnicity, education, income, marital status, and seniority. There was no association between workplace discrimination and heavy drinking or drinks per month. CONCLUSIONS: Cross-sectional data from a sample of urban transit operators indicates an association between workplace racial discrimination and some measures of alcohol consumption.

Psychosocial job factors, physical workload, and incidence of work-related spinal injury: a 5-year prospective study of urban transit operators.

STUDY DESIGN: Five-year prospective cohort study of 1449 transit operators. OBJECTIVES: To investigate psychosocial job factors as predictors of work-related spinal injuries, controlling for current and past physical workload. SUMMARY OF BACKGROUND DATA: The association between psychosocial job factors and spinal disorders may be confounded by physical workload. A 1991 prospective study of Boeing workers found psychosocial but not physical factors to be associated with spinal injuries. However, data on physical workload were limited. Recent cross-sectional studies of transit drivers showed both physical and psychosocial factors to be independently associated with back and neck pain. This study was designed to test these findings prospectively. METHODS: Spinal injuries were ascertained from workers' compensation records, employment history from company records, and psychosocial factors from questionnaires. Logistic regression models adjusted for age, gender, height, weight, vehicle type, and current and past physical workload. RESULTS: During follow-up, 320 drivers reported a first spinal injury. Spinal injury was predicted by psychological job demands (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.33-1.95); job dissatisfaction (OR, 1.56; 95% CI, 1.09-2.23); and the frequency of job problems (OR, 1.52; 95% CI, 1.02-2.26). Marginally significant associations were found for low supervisor support (OR, 1.30; 95% CI, 0.99-1.72) and female gender (OR, 1.49; 95% CI, 0.95-2.32). Compared with full-time work, part-time work was associated with a 2.7-fold reduced risk for spinal injury (OR, 0.37; 95% CI, 0.15-0.93). Cable car crews performing the heaviest physical labor had a threefold increased risk of spinal injury compared with bus drivers (OR, 3.04; 95% CI, 1.85-5.00). CONCLUSIONS: Physical workload and psychosocial job factors both independently predict spinal injury in transit vehicle operators.

Disease and injury in California with projections to the year 2007. Implications for medical education.

In this article, as part of an evaluation of the future of medical education in California, we characterize the distribution of disease and injury in California; identify major factors that affect the epidemiology of disease and injury in California, and project the burden of disease and injury for California's population to the year 2007. Our goal is to elucidate the major causes of illness and disability at present and in the near future in order to focus state resources on the interventions likely to have the greatest impact. Data from various governmental agencies were utilized; the base year, 1993, is the most recent year with sufficient information available when this report was prepared. Several major risk factors have decreased, including smoking (30% decline from 1984 to 1993) and drinking and driving. However, hypertension prevalence has not changed, and overweight has increased dramatically. Poverty continues to burden about 15% of Californians, with poverty highest among children. During 1993, 220,271 Californians died, with 3 major causes accounting for 61% of these deaths: coronary heart disease (31%), cancer (23%), and stroke (7%). In terms of potential years of life lost (years lost before age 65), the most important causes of death in 1993 were unintentional injury (756 years lost/100,000 population), cancer (632 years), and the acquired immunodeficiency syndrome (AIDS; 491 years). Mortality rates were highest among blacks and lowest among Asians. Overall mortality in California has been declining for decades; in just 1 decade, from 1980 to 1991, mortality declined from 780 to 680 deaths per 100,000 population. Several major causes of death have declined, including coronary heart disease, stroke, unintentional injury, cirrhosis, and suicide, while others have increased, for example, chronic obstructive lung disease and diabetes mellitus. Death from AIDS increased dramatically in the past decade, but is leveling off, and death from cancer is beginning to decline. Rates for overall mortality and morbidity, and for most specific conditions, should continue to decline. A projected 28% population increase by 2007 will yield a corresponding increase in the absolute level of disease cases and death; a disproportionate increase in younger and older groups will yield increased conditions affecting young (unintentional injury, AIDS) and older (heart disease, cancer, stroke, diabetes mellitus) people. Californians should experience overall improved health in coming years, reaping benefits of reduced environmental and behavioral risk factors as well as improved medical treatment and rehabilitation. Coordinated strategies for health promotion, disease prevention, delivery of medical treatment, and rehabilitation are needed to maintain and improve present levels of health across the life span.

Objective stress factors, accidents, and absenteeism in transit operators: a theoretical framework and empirical evidence.

The authors used observational job analysis as a conceptually based technique to measure stress factors unbiased by worker appraisal with 81 transit driving tasks on 27 transit lines. Stressor dimensions included work barriers that interfere with task performance due to poor technical-organizational design, time pressure, time binding (autonomy over time management), and monotonous conditions. Line-specific average stressor values were assigned to 308 transit operators who mainly worked the particular line. Logistic regression analyses showed associations for high work barriers and sickness absences (odds ratio [OR] = 3.8, p = .05). There were elevated risks for work accidents for high time pressure operators (OR = 4.0, p = .04) and for the medium time-binding group (OR = 3.3, p = .04) and significant (alpha = .20) unadjusted interaction terms for barriers and time pressure in predicting accidents and absences, and barriers and time binding in predicting absences. Findings suggest guaranteed rest breaks and flexible timing for accident prevention and removal of work barriers for reducing absenteeism.

Studies of health outcomes in transit operators: policy implications of the current scientific database.

Urban transit operators' medical symptoms and conditions exceed other occupational groups, resulting partly from working conditions. Medical outcomes among operators have an impact on the transit system, including on performance, work attendance, and medical costs. This is exacerbated by external economic and political pressures in which expected service often exceeds the system's capacity in a congested, chaotic urban environment. A vicious cycle of poor working environment, reduced health and well-being among operators, and lowered efficiency and increased costs often results. Operator-health policies focusing solely on individuals are not sufficient to address these problems. A broader approach is needed, acknowledging the relationship between health of the system and health of employees, including redesigning the interface between transit systems and the urban environment and organizational change within companies. This comprehensive approach recognizes the dynamic reciprocity among the transit operators, the transit system, and the larger community.

Physical workload and ergonomic factors associated with prevalence of back and neck pain in urban transit operators.

STUDY DESIGN: Back and neck pain was studied cross-sectionally in 1,449 urban transit drivers by linking medical data, self-reported ergonomic factors, and company records on job history. OBJECTIVES: The goal was to examine the relation between physical workload, ergonomic factors, and the prevalence of back and neck pain. SUMMARY OF BACKGROUND DATA: Researchers, to date, have not found an independent effect of ergonomic factors on back and neck pain while accounting for the effects of past and current physical workload. METHODS: Self-reported ergonomic factors, vehicle type, physical workload (measured as duration of driving), height, weight, age, and gender were analyzed in relation to back and neck pain, using multivariable logistic regression models. RESULTS: Physical workload showed a positive dose-response relation with back and neck pain after controlling for vehicle type, height, weight, age, and gender. The odds ratio for 10 years of driving was 3.43. Additional adjustment for ergonomic factors decreased this odds ratio to 2.55. Six out of seven ergonomic factors were significantly related to the prevalence of back and neck pain after adjustment for age, gender, height, weight, and physical workload. Problems with adjusting the seat had the largest effect (odds ratio = 3.52). Women had back and neck pain twice as frequently as men. CONCLUSION: The results support the hypothesis of a causal role of physical workload for the development of back and neck pain. Ergonomic factors partially mediated the risk of back and neck pain associated with driving, suggesting a potential for prevention of back and neck pain by ergonomic redesign of transit vehicles. Elevated risks for back and neck pain for female drivers were not explained by anthropometric and ergonomic factors.

Psychosocial job factors associated with back and neck pain in public transit operators.

OBJECTIVES: This cross-sectional study examined associations between psychosocial job factors and the prevalence of nondisabling back and neck pain in professional drivers after physical work load was taken into account. METHODS: A total of 1449 transit vehicle operators completed a medical examination and a questionnaire yielding information on demographic and anthropometric variables, health status, and physical and psychosocial job factors. Company records were used to supplement information on employment history. Physical work load was measured in life-time years and current weekly hours of professional driving. The relation of psychosocial factors with back or neck pain was analyzed by logistic regression models adjusted for past and current physical work load, vehicle type, age, gender, body height, and weight. RESULTS: The main result of this study was that both physical work load and psychosocial factors were simultaneously and independently associated with back or neck pain. Psychosocial factors associated with back or neck pain included extended uninterrupted driving driving periods, frequency of job problems, high psychosocial demands, high job dissatisfaction, and low supervisory support. An analysis of specific job problems is provided which may be useful in setting priorities for research and intervention efforts in this high risk occupation. CONCLUSION: The results provide support for the role of psychosocial job characteristics in the etiology of back or neck pain in occupational settings.

Social dominance and 22-year all-cause mortality in men.

OBJECTIVE: Research findings suggest that, in addition to hostility, social dominance-related variables may be related to morbidity and mortality. The purposes of the present study were to evaluate a) whether pressured social dominance (defined as a pattern of structured-interview-defined characteristics of verbal competition, immediateness of response, and fast speaking rate) was related to long-term health outcomes, namely, all-cause mortality, and b) whether individuals characterized by other patterns of structured-interview-derived characteristics also varied in terms of mortality. METHOD: The present study represents an analysis of the data from the 22-year mortality follow-up of 750 men from the Western Collaborative Group Study. Cluster analytic techniques were used to classify individuals according to their speech and behavioral characteristics during a structured interview. Cox proportional hazards models were used to test the association between the behavioral characteristics and the risk of all-cause mortality. RESULTS: The pattern of characteristics reflecting pressured social dominance was found to be positively related to mortality (RR = 1.6, 95% CI = 1.1-2.4, p < .02); this relation held after controlling for diastolic blood pressure, total cholesterol, and smoking status at study entry, and also after controlling for hostility. In addition, the pattern of characteristics in which hostility was salient was found to be positively related to mortality (RR = 1.5, 95% CI = 1.1-2.2, p < .02). Finally, a pattern of characteristics that suggests placid individuals who are neither hostile nor socially dominant was found to be significantly negatively related to mortality (RR = .638, 95% CI = .419-.974, p < .04). CONCLUSIONS: These results suggest that, in future research concerning psychosocial factors and long-term survival, attention should be given to social dominance as well as to hostility.

Hypertension and years of driving in transit vehicle operators.

In this study, data from transit vehicle operators of the San Francisco Municipal Railway (Muni), and a control group of individuals newly hired but not yet working as operators, were used to investigate prevalence of hypertension as a function of exposure to bus driving (years of driving), controlling for alcohol consumption and body mass index. Data were collected from transit vehicle operators in the course of their regular biennial examination during the period November 1983 to October 1985. Groups working as operators fewer than 10 years (n = 1137), from 10 to 20 years (n = 493), and more than 20 years (n = 196) were compared to each other and to a group of individuals with no prior exposure, but who were given a medical examination just before beginning their jobs as transit vehicle operators (n = 226). For hypertension (defined as systolic blood pressure > or = 140, or diastolic blood pressure > or = 90, or taking hypertension medication), the prevalence, adjusted for age, race, and gender, increased in a stepwise fashion from 28.8 percent in the group with no exposure to 38.9 percent in the group of drivers with more than 20 years on the job. A similar pattern was found for moderate to severe hypertension (systolic blood pressure > or = 160, or diastolic blood pressure > or = 95, or hypertension medication). These patterns were diminished, but not eliminated, when body mass index and alcohol consumption were considered. Higher rates of separation from employment for hypertensive operators suggested that the effect of years of employment may be underestimated by this cross-sectional comparison. Prolonged exposure to operating a transit vehicle may be associated with increased hypertension; increased alcohol consumption and body mass index with increased years of driving may account for at least some of the increased hypertension.

Objective measurement of occupational stress factors--an example with San Francisco urban transit operators.

Eighty-one observational work analyses were conducted to measure stressors independently of worker appraisal in the San Francisco transit system. On the basis of action regulation theory, stress factors were defined as hindrances for task performance due to poor work organization or technological design. Stressors included (a) work barriers, defined as obstacles that cause extra work or unsafe behavior; (b) time pressure; (c) monotonous conditions; and (d) time binding, defined as control over timing. Reliability, measured as interrater agreement, ranged between 80 and 97%, with kappas of .46-.70. Validity analyses were done with 71 transit operators who participated in the observations and 177 operators who were assigned mean line-specific observational stressor measures. High odds ratios (ORs) were found for barriers and psychosomatic complaints (OR = 3.8, p = .00), time pressure and relaxation time needed after work (OR = 3.1, p = .05), and barriers and smoking to cope (OR = 3.8, p = .02). Using observational data in conjunction with self-report data can reduce confounding and improve interpretability of stress and health studies.