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M J Reilly

Publications and source records attributed to M J Reilly.

At least 19 recordsLinked to original sources
PubMed2001

What is the most cost-effective way to identify silica problem worksites?

BACKGROUND: State based surveillance systems to identify cases of silicosis have been developed over the past 18 years to target worksite interventions to reduce the incidence of silicosis. Using data from the Michigan silicosis surveillance system, we conducted an analysis to determine the most cost-effective way to identify problem worksites. METHODS: The initial reporting source of all 470 confirmed cases of silicosis reported to the Michigan surveillance system from 1989 to 1995 was identified. The cost of identifying confirmed cases, worksites, problem worksites, silica problem worksites, and the number of current silica-exposed workers was determined for four reporting sources: hospitals; physicians; workers' compensations; and death certificates. RESULTS: Hospital reports were the first to identify 67% of the confirmed cases, 74% of the worksites, and 58% of the problem worksites. Physician reports initially identified 17% of confirmed cases, 15% of worksites, and 26% of problem worksites. Workers' compensation records initially identified 11% of confirmed cases, 4% of worksites, and 8% of problem worksites. Death certificates initially identified 5% of confirmed cases, 7% of worksites, and 8% of problem worksites. Hospital reports were the most cost-effective way to identify cases (US$ 143), worksites (US$ 313), and problem worksites (US$ 454). CONCLUSIONS: Hospital discharge records identified the greatest number of confirmed cases and problem worksites and was the most cost-effective approach to identify both individuals with silicosis and worksites with problems.

Cost-Benefit Analysis↗
PubMed2000

Human osteoblast-like cells and osteosarcoma cell lines synthesize macrophage inhibitory protein 1alpha in response to interleukin 1beta and tumour necrosis factor alpha stimulation in vitro.

Recent investigations have demonstrated that macrophage inhibitory protein 1alpha (MIP-1alpha) plays a critical role in haematopoiesis. In part, MIP-1alpha limits the differentiation of early haematopoietic cells, thereby ensuring that sufficient quantities of blood precursors are available to meet haematopoietic demands. MIP-1alpha is produced by cells of the marrow microenvironment (marrow stromal cells) in response to a variety of stimuli, including interleukin 1beta (IL-1beta) and tumour necrosis factor alpha (TNF-alpha). Our recent investigations demonstrated that normal human osteoblast-like cells (HOBs) maintain the early phenotype of haematopoietic precursors, like other members of the bone marrow stroma. Although the precise molecular mechanisms for these observations have not been determined, the production of MIP-1alpha remains one such possibility. In the present study, we investigated whether cells of the osteoblast lineage under basal, IL-1beta and/or TNF-alpha stimulation produce MIP-1alpha. We observed that IL-1beta and TNF-alpha stimulated HOBs and human osteosarcoma cells to rapidly express MIP-1alpha mRNA and to secrete large quantities of the protein. MIP-1alpha mRNA and protein was not, however, detected under basal conditions. Perhaps more importantly, enriched human CD34+ bone marrow cells in co-culture may be capable of stimulating the expression of MIP-1alpha mRNA by HOBs in vitro. These findings suggest that human osteoblast-like cells may produce MIP-1alpha in vivo to support haematopoiesis at sites where osteoblasts and haematopoietic cells are closely associated.

Bone Neoplasms↗
PubMed2000

Caged ATP - an internal calibration method for ATP bioluminescence assays.

ATP bioluminescence, based on the firefly luciferase system, is used for the rapid determination of hygienic practices in the food industry. This study has demonstrated the use of caged ATP as an internal ATP standard and quantified the effects of industrial cleansing solutions, alcoholic beverages and pH on firefly luciferase activity. The light signal was quenched 6-47% by five cleansing solutions at standard working concentrations. Ethanol at 1% (v/v) inhibited bioluminescence by 15% (w/v) whereas concentrations above 4% enhanced the light output. The light signal was quenched by 20-25% at pH values below pH 4 and above pH 10.

Adenosine Triphosphate↗
PubMed2000

Why most workers with occupational repetitive trauma do not file for workers' compensation.

Despite the availability of no fault insurance for wage replacement and medical care costs, the majority of workers diagnosed with an occupational disease do not apply for workers' compensation. The objective of the study was to determine the reasons why workers diagnosed with work-related musculoskeletal disease did not apply for workers' compensation benefits. A cross-sectional study of 1598 individuals diagnosed with neck, upper extremity, and low back work-related musculoskeletal disease from April to June 1996 was performed. All individuals were interviewed over the telephone using a standardized questionnaire. The questionnaire included questions about the precipitating event; demographics; health limitations; mood; pain level; and attitudes toward their health care provider, fellow workers, management, work environment, and filing for workers' compensation. Whenever possible, standardized questions from previous surveys were used. The interviewed individuals with work-related musculoskeletal disease were reported by health care practitioners as required by the state of Michigan's occupational disease reporting law. Workers reported during 12 weeks in the spring of 1996 by a Michigan health care professional as having a neck, back, or upper extremity musculoskeletal disorder were eligible to participate. Among the 2703 reports received, 490 individuals could not be reached, 22 did not speak English, 12 had died or were too incapacitated by other medical conditions, and 581 refused. We interviewed 59% of all eligible workers and 73% of all workers who were reachable and capable of responding in English. Only 25% of workers diagnosed with musculoskeletal disease filed a workers' compensation claim. The factors significantly associated with filing a claim were (1) increased length of employment (> 21 years: odds ratio [OR], 3.01, 95% confidence interval [CI], 1.31 to 6.90); 11 to 20 years: OR, 2.34, 95% CI, 1.01 to 5.47; 6 to 10 years: OR, 1.76, 95% CI, 0.73 to 4.25; 1 to 5 years: OR, 2.36, 95% CI, 1.03 to 5.42; < 1 year: OR, 1.00; (2) lower annual income (< $40,000: OR, 1.75, 95% CI, 1.06 to 2.88 vs > or = $80,000: OR, 1.00); (3) workers' dissatisfaction with coworkers (OR, 1.76, 95% CI, 1.01 to 3.06); (4) physician restrictions on activity (OR, 2.16, 95% CI, 1.55 to 3.00); (5) type of physician providing treatment (specialist, including surgeon or orthopedist: OR, 3.63, 95% CI, 2.37 to 5.55); physical and occupational therapist: OR, 2.15, 95% CI, 1.35 to 3.43); family practitioner: OR, 1.33, 95% CI = 0.89 to 2.01; company physician: OR = 1.00); (6) off work > or = 7 days (OR, 14.85, 95% CI, 10.57 to 20.85); (7) decreased current health status (OR, 0.82, 95% CI, 0.70 to 0.96); and (8) increased severity of illness (OR, 1.24, 95% CI, 1.06 to 20.88). This study showed that only 25% of workers with a work-related musculoskeletal condition filed for workers' compensation and refutes the common perception that an individual with a work-related problem is likely to file a workers' compensation claim. The strongest predictors of who would file were those factors associated with the severity of the condition. Other factors were increasing length of employment, lower annual income, and worker dissatisfaction with coworkers. Our study population consisted mainly of unionized autoworkers, and our findings may not be generalizable to the total workforce.

Adolescent↗
PubMed2000

Kidney disease and silicosis.

AIM: To determine the prevalence of kidney disease in a cohort of individuals with silicosis. METHODS: Review of medical records and questionnaires from patients reported to a state surveillance system for silicosis. Reporting of individuals with silicosis is required by state law. All individuals with silicosis reported as required by law to the State of Michigan. Individuals included in this article were reported from 1987 to 1995. Cases were reported by hospitals, physicians, the state workers' compensation bureau, or from death certificates. Only individuals who met the criteria for silicosis developed by the National Institute for Occupational Safety and Health (NIOSH) were included. RESULTS: Medical records were reviewed of 583 individuals with confirmed silicosis. This was mainly a population of elderly men. Ten percent of the 583 silicotics were found to have some mention of chronic kidney disease, and 33% of the 283 silicotics who we had laboratory tests on had a serum creatinine level >1.5 mg/dl. An association between kidney disease and age and between kidney disease and race was found among this cohort of 583 silicotics. Individuals with silicosis were more likely to have a serum creatinine level >1.5 mg/dl than age- and race-matched controls. However, no relationship between duration of exposure to silica or profusion of scarring on chest X-ray and prevalence of kidney disease or elevated creatinine levels was found. CONCLUSIONS: This study confirms previous case reports and epidemiologic studies of end-stage renal disease that found an association between kidney disease and exposure to silica. The epidemiologic data are conflicting on the mechanism by which silica causes kidney disease and are compatible with silica being able to cause kidney disease by both an autoimmune and direct nephrotoxic effect. Chronic kidney disease should be considered as a complication of silicosis.

Aged↗
PubMed1999

Surveillance of work-related asthma in selected U.S. states using surveillance guidelines for state health departments--California, Massachusetts, Michigan, and New Jersey, 1993-1995.

PROBLEM/CONDITION: Cases of work-related asthma (WRA) are sentinel health events that indicate the need for preventive intervention. WRA includes new-onset asthma caused by workplace exposure to sensitizers or irritants and preexisting asthma exacerbated by workplace exposures. REPORTING PERIOD: This report reviews cases of WRA identified by state health departments from January 1, 1993, through December 31, 1995, as well as follow-up investigations of cases and associated workplaces conducted through June 30, 1998. DESCRIPTION OF THE SYSTEMS: State-based surveillance and intervention programs for WRA are conducted in California, Massachusetts, Michigan, and New Jersey as part of the Sentinel Event Notification Systems for Occupational Risks (SENSOR) cooperative agreement program, initiated by CDC's National Institute for Occupational Safety and Health (NIOSH). RESULTS: From 1993 through 1995, a total of 1,101 cases of WRA were identified by SENSOR surveillance staff members in California, Massachusetts, Michigan, and New Jersey. Of these 1,101 cases, 19.1% were classified as work-aggravated asthma, and 80.9% were classified as new-onset asthma. Objective evidence substantiating asthma work-relatedness was documented in the medical records of 3.4% of WRA cases identified in the two states (Michigan and New Jersey) where medical records are routinely reviewed for this information. Indoor air pollutants, dusts, cleaning materials, lubricants (e.g., metalworking fluids), and diisocyanates were among the most frequently reported causes of WRA. In addition, a well-recognized cause of occupational asthma - natural rubber latex - was identified in a new setting, the healthcare industry. The most common industries associated with WRA cases included transportation equipment manufacturing (19.3%), health services (14.2%), and educational services (8.7%). Air sampling for agents known to induce occupational asthma was performed in Michigan for comparison with established federal time-weighted average exposure limits. Sixteen (13.4%) of 119 workplaces tested had airborne concentrations exceeding NIOSH recommended exposure limits (RELs); 11 (9.1%) of 121 workplaces had concentrations exceeding permissible exposure limits (PELs) of the Michigan Occupational Safety and Health Act (MIOSHA) program. INTERPRETATION: The surveillance data findings confirm well-recognized causes of asthma and have identified new putative causes (e.g., cleaning materials and metalworking fluids). Because the surveillance program depends on physicians' recognizing asthma work-relatedness and reporting diagnosed cases, the data are considered an underestimate of the magnitude of the WRA problem. The data also indicate that physicians are not commonly performing objective physiologic tests to substantiate a WRA diagnosis. Workplace findings suggest a need to evaluate existing exposure standards for specific agents known to induce occupational asthma (e.g., diisocyanates). Case-based surveillance can help improve the recognition, control, and prevention of WRA. The SENSOR model also provides a mechanism for workers and physicians to request workplace investigations aimed at primary prevention for other workers. PUBLIC HEALTH ACTION: NIOSH and state health department representatives are working to establish a long-term agenda for state-based surveillance of work-related conditions and hazards. The results from the SENSOR WRA programs described in this report support inclusion of WRA as a priority condition warranting surveillance at the state level.

Asthma↗
PubMed1999

Connective tissue disease and silicosis.

BACKGROUND: To determine the prevalence of connective tissue disease in a cohort of individuals with silicosis, we reviewed the medical records and questionnaires from individuals reported from 1987 to 1995 to a state surveillance system for silicosis. Reporting of individuals with silicosis is required by state law. Cases were reported by hospitals, physicians, the state workers' compensation bureau, or from death certificates. Only individuals who met the criteria for silicosis developed by the National Institute for Occupational Safety and Health (NIOSH) were included in the analysis. RESULTS: A questionnaire was completed for all 583 cases. Medical records were available for 463. There were 24 people with rheumatoid arthritis, one with scleroderma, and one with systemic lupus erythematosus. All were men. The prevalence of rheumatoid arthritis was 5.2% (relative risk (RR) 2.73, 95% confidence limit (CL) 1.75-4.06). The prevalence of scleroderma was 0.2% (RR 15.65, 95% CL 0.21-87.03) and the prevalence of systemic lupus erythematosus was 0.2% (RR 11.37, 95% CL 0.15-63.23). This is an approximately 2.5-15-fold increased risk for these connective tissue diseases compared to estimated prevalences in the general population. Individuals with silicosis and connective tissue disease did not differ from individuals with silicosis but without connective tissue disease by race, age, type of industry where exposed to silica, history of tuberculosis, whether or not they had applied for workers' compensation, and whether or not they had progressive massive fibrosis on chest x-ray. CONCLUSION: Although the association between scleroderma and silicosis has been more widely reported in the literature, the prevalence of rheumatoid arthritis was greater than the prevalence of scleroderma or systemic lupus erythematosus among a cohort of individuals with silicosis.

Arthritis, Rheumatoid↗
PubMed1998

Asbestos-related x-ray changes in foundry workers.

Michigan has a statewide mandatory occupational disease reporting system. As part of that system, reports are received from hospital, physicians, death certificates, the worker's compensation bureau, and company medical departments. Based on this reporting, the State of Michigan has a special emphasis program for the surveillance of silicosis, a known disease outcome among foundry workers. From 1985-1996, 115 cases reported to the State Surveillance System as silicosis, pneumoconiosis not specified, or pulmonary fibrosis were reclassified as having asbestos related x-ray changes after a B-reader interpretation of each case's chest x-ray. During this same period there were an additional 697 reports confirmed as silicosis and 6,724 cases reported to the surveillance system as asbestosis. Among the 115 reports reclassified as having asbestos-related x-ray changes without evidence of silicosis-related x-ray changes, 54 had worked in foundries. Only 7 (14.8%) of these individuals had their primary work in maintenance in the foundry; 40 (85.1%) had their primary foundry work in a production job; and for 10 individuals the occupation was not known. Asbestos has been used in foundries on pipe laggings, boiler coverings, as insulation in fan housings, in gloves, aprons and curtains, as insulation in cupolas, and in ladles and insulation in sand molds. Clinicians caring for foundry workers need to be aware that asbestos-related x-ray changes are not uncommon in this population and asbestos exposure should be considered as one of the carcinogens contributing to the known increased risk of lung cancer among foundry workers.

Aged↗
PubMed1998

Occupational noise-induced hearing loss surveillance in Michigan.

Occupational noise-induced hearing loss (NIHL) is an important yet often overlooked illness that can affect an individual's safety and performance at work. This article describes a state-based surveillance system for occupational NIHL. The Michigan surveillance system enables us to describe the magnitude of occupational NIHL among Michigan workers and direct public health interventions in the form of enforcement workplace inspections. The data presented are based on interviews of individuals with occupational NIHL reported to the Michigan Department of Consumer and Industry Services (MDCIS) by Michigan's audiologists and otolaryngologists from 1992-1997. From 1992-1997, 1378 individuals with occupational NIHL were reported to the MDCIS and interviewed about their exposures to noise at work. Over 70% of the workplace noise exposure were in manufacturing. At the most recent company where these individuals were exposed to noise, approximately 46% were not provided regular hearing testing. Regular hearing testing was more likely to occur in the larger companies and in industries covered by regulations requiring such testing to be performed. There were improvements over time in the percentages of companies providing regular hearing testing and hearing protection. Construction workers are employees among a group of industries that are not adequately protected from excessive noise exposures by occupational regulations. Regular hearing testing was not provided for over 90% of construction jobs, although hearing protection such as earplugs or earmuffs was provided for approximately half of these jobs. Forty-three state enforcement inspections were conducted at the companies reported by the patients interviewed, because these companies were reported to provide no regular hearing testing or no hearing protection despite exposures to excessive levels of noise. During the 43 inspections, 23 companies had noise levels above dBA, and 17 of those had either no hearing conservation program (HCP) or had one that was cited as being incomplete. The inspections potentially protected 758 similarly exposed workers in the companies with the high noise levels that lacked an HCP or that had a deficient HCP. The number of patients with occupational NIHL is likely a gross underestimate of the true magnitude of the disease. However, the surveillance system has identified workplaces with hazardous levels of noise and no HCP, thereby protecting similarly exposed coworkers of the index patients from further exposures to noise and hearing loss.

Ear Protective Devices↗
PubMed1997

Augmented production of interleukin-6 by normal human osteoblasts in response to CD34+ hematopoietic bone marrow cells in vitro.

Based on anatomic and developmental findings characterizing hematopoietic cells in close approximation with endosteal cells, we have begun an analysis of osteoblast/hematopoietic cell interactions. We explore here the functional interdependence between these two cell types from the standpoint of de novo cytokine secretion. We determined that, over a 96-hour period, CD34+ bone marrow cells had no significant effect on osteoblast secretion of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, or transforming growth factor-beta1, but in some experiments minor increases in leukemia inhibitory factor levels were observed. However, when CD34+ bone marrow cells were cocultured in direct contact with osteoblasts, a 222% +/- 55% (range, 153% to 288%) augmentation in interleukin-6 (IL-6) synthesis was observed. The accumulation of IL-6 protein was most rapid during the initial 24-hour period, accounting for nearly 55% of the total IL-6 produced by osteoblasts in the absence of blood cells and 77% of the total in the presence of the CD34+ cells. Cell-to-cell contact does not appear to be required for this activity, as determined by coculturing the two cell types separated by porous micromembranes. The identity of the soluble activity produced by the CD34+ cells remains unknown, but is not likely due to IL-1beta or tumor necrosis factor-alpha, as determined with neutralizing antibodies. To our knowledge, these data represent the first demonstration that early hematopoietic cells induce the production of molecules required for the function of normal bone marrow microenvironments, in this case through the induction of hematopoietic cytokine (IL-6) secretion by osteoblasts.

Biological Factors↗
PubMed1997

Surveillance for silicosis, 1993--Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin.

PROBLEM/CONDITION: Silicosis is an occupational respiratory disease caused by the inhalation of respirable dust containing crystalline silica. Public health surveillance programs to identify workers at risk for silicosis and target workplace-specific and other prevention efforts are currently being field-tested in seven U.S. states. REPORTING PERIOD COVERED: Confirmed cases ascertained by state health departments during the period January 1, 1993, through December 31, 1993; the cases and associated workplaces were followed through December 1994. DESCRIPTION OF SYSTEMS: As part of the Sentinel Event Notification System for Occupational Risks (SENSOR) program initiated by CDC's National Institute for Occupational Safety and Health (NIOSH), development of state-based surveillance and intervention programs for silicosis was initiated in 1987 in Michigan, New Jersey, Ohio, and Wisconsin and in 1992 in Illinois, North Carolina, and Texas. RESULTS: From January 1, 1993, through December 2, 1994, the SENSOR silicosis programs in Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin confirmed 256 cases of silicosis that were initially ascertained in 1993. Overall, 185 (72%) were initially identified through review of hospital discharge data or through hospital reports of silicosis diagnoses; 188 (73%) were associated with silica exposure in manufacturing industries (e.g., foundries; stone, clay, glass, and concrete manufacturers; and industrial and commercial machinery manufacture). Overall, 42 (16%) cases were associated with silica exposure from sandblasting operations. Among the 193 confirmed cases for which information was available about duration of employment in jobs with potential exposure to silica, 37 (19%) were employed < or = 10 years in such jobs and 156 (81%) were employed > or = 11 years. A total of 192 primary workplaces associated with potentially hazardous silica exposures were identified for the 256 confirmed silicosis cases. Of these, nine (5%) workplaces were inspected by state health department (SHD) industrial hygienists, 19 (10%) were referred to the Occupational Safety and Health Administration (OSHA) for follow-up, and seven (4%) were routinely monitored by the Mine Safety and Health Administration. Of the 157 (82%) remaining workplaces, follow-up activities determined that 82 were no longer in operation, eight were no longer using silica, 18 were assigned a lower priority for follow-up, six were associated with building trades and could not be inspected because of the transient nature of work in the construction industry, and 43 workplaces were not inspected for other reasons. Fourteen (7%) of the 192 workplaces were inspected. At 10 of the 14 workplaces, airborne levels of crystalline silica were measured; in nine, silica levels exceeded the NIOSH-recommended exposure level of 0.05 mg/m, and in six, airborne silica levels also exceeded federal permissible exposure limits. ACTIONS TAKEN: Employee-specific and other preventive interventions have been initiated in response to reported cases. In addition, special silicosis prevention projects have been initiated in Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin. To facilitate the implementation of silicosis surveillance by other states, efforts are ongoing to identify and standardize core data needed by surveillance programs to describe cases and the workplaces where exposure occurred. These core variables will be incorporated into a user-friendly software system that states can use for data collection and reporting.

Female↗
PubMed1997

Work-related asthma and respiratory symptoms among workers exposed to metal-working fluids.

The objective of this work was to determine whether the prevalence of respiratory symptoms differed among workers exposed to different types of metal-working fluids. As part of a mandatory surveillance system for occupational illness, from 1988-1994, the Michigan Department of Public Health received, 86 occupational disease reports of work-related asthma secondary to exposure to metal-working fluids. As part of a public health program, follow-up industrial hygiene inspections, including medical interviews of the workforce, were performed at companies where the reported cases had become ill. Metal-working fluids were the second most common cause of work-related asthma reported in the state. Most of the reports were from the automobile industry. Follow-up inspections were conducted at 37 facilities where the individuals with work-related asthma had worked. Seven hundred and fifty-five workers at these facilities were interviewed. Only one facility was above the allowable oil mist standard. Despite the exposure levels being within the legal limits, approximately 20% of the fellow workers of the reported cases had daily or weekly respiratory symptoms suggestive of work-related asthma. Workers exposed to emulsified, semisynthetic, or synthetic machining coolants were more likely to have chronic bronchitis; to have visited a doctor for shortness of breath; to have visited a doctor for a sinus problem; to be bothered at work by nasal stuffiness, runny nose, or sore throat; and to have an increased prevalence of respiratory symptoms consistent with work-related asthma, compared to workers exposed to mineral oil metal-working fluids. These findings were found in individuals who currently smoked, had never smoked or were ex-cigarette smokers. Further research to determine the chemical components or microbial contaminants responsible for these findings is needed.

Air Pollutants, Occupational↗
PubMed1997

Human osteosarcomas inhibit hematopoietic colony formation: partial reversal by antibody to transforming growth factor-beta 1.

Recently we found that primary human osteoblast-like cells (HOBs) support hematopoietic progenitor cells (assayed by colony formation in methylcellulose) and long-term culture initiating (LTC-IC) activity in vitro. In the present investigation, we evaluate whether human osteosarcoma cells share in these activities. We observed that relative to controls, significantly fewer hematopoietic colonies were formed in the presence of HOS TE85, MG-63, SaOS-2, or U2-OS human osteosarcomas. In addition, neither MG-63 or SaOS-2 cells supported hematopoietic progenitor cell activity or LTC-IC activity in vitro. We established that the suppressive activity produced by the osteosarcomas is soluble, correlated with osteosarcoma cell number and is partially neutralized with antibody to TGF-beta 1,2,3. While it is clear that the osteosarcomas express several phenotypic characteristics of primary human osteoblasts, these data suggest that they may be functionally disregulated with regard to their ability to support normal hematopoiesis. For these reasons, caution should be exercised when evaluating osteoblastic and hematopoietic cell interactions based purely on the use of osteosarcoma cell lines.

Antibodies↗
PubMed1997

Infection and replication of human cytomegalovirus in bone marrow stromal cells: effects on the production of IL-6, MIP-1alpha, and TGF-beta1.

We have investigated the mechanisms by which hematopoiesis is suppressed in patients suffering from human cytomegalovirus (HCMV) infections. Mixed populations of human bone marrow stromal and hematopoietic progenitor cells were inoculated with the Towne strain of HCMV to determine whether these populations could be infected and support HCMV replication. We found that the Towne strain of HCMV was capable of infecting and replicating in a mixed population of bone marrow stromal cells. We observed no significant alterations in bone marrow stromal cell proliferation or the production of IL-6, GM-CSF, soluble c-kit ligand and TNF-alpha following HCMV replication in either stimulated lipopolysaccharide (LPS) or unstimulated conditions. In samples of culture supernatants from LPS-stimulated HCMV-infected stromal cells, significant elevations in MIP-1alpha were observed. TGF-beta1 levels on the other hand exhibited two patterns following HCMV exposure; either TGF-beta1 levels decreased regardless of LPS stimulation or there was no effect. In addition, we observed that exposure to the Towne strain of HCMV resulted in significant inhibition of both granulocytic and erythrocytic colony formation in methylcellulose progenitor assays. Thus, both the direct effect of HCMV on hematopoietic progenitors as well as altered cytokine production by bone marrow stromal cells (including MIP-1alpha and TGF-beta1, but not IL-6) could contribute to hematopoietic failure during HCMV infection.

Adipose Tissue↗
PubMed1997

A state-based surveillance system for work-related asthma.

The current national surveillance system for occupational illnesses underestimates the incidence of work-related asthma. This article describes a state-based surveillance system for work-related asthma. The Michigan surveillance system enables us to estimate the incidence of work-related asthma, describe the characteristics of affected individuals, and facilitate public health interventions in the form of workplace inspections. The data presented are based on interviews with a case-series of individuals with work-related asthma reported to the Michigan Department of Public Health (MDPH) from 1988 to 1994. We also present cross-sectional data on coworkers of the index cases, who were interviewed during the workplace investigations, and exposure measurements from those investigations. Potential cases were reported by physicians, hospitals, or the Michigan Department of Labor. Case eligibility was based on the criteria for work-related asthma developed by the National Institute for Occupational Safety and Health (NIOSH). Between 1988 and 1994, 725 people who met the NIOSH criteria for work-related asthma were reported to the MDPH. Seventy-six percent of the reports were from physicians, 17.1% were from hospitals, 7.3% were from workers' compensation records, and 3.5% were from other health professionals. Eighty-three percent of the reports were for individuals with the onset of newly diagnosed asthma after a period of symptomless exposure, 7.3% were for aggravation of preexisting asthma, and 9.5% were for reactive airway dysfunction syndrome (RADS). The overall annual average incidence rate of work-related asthma in Michigan was 2.9 cases per 100,000 workers. Rates were 0.8/100,000 in the service industry and 8.5/100,000 in manufacturing. Isocyanates and machining coolants were the two most common causes of asthma among workers reported to the surveillance system. Demographics of the individuals reported are described. During workplace follow-up investigations, 861 fellow workers were identified as having possible work-related asthma. Another 151 coworkers were identified from the company-maintained injury and illness logs as having possible work-related asthma. In addition, the investigations identified two new causes of work-related asthma. The primary limitations of the surveillance system include a lack of objective testing to confirm the diagnosis of work-related asthma and underreporting of cases. Despite these limitations, this state-based surveillance system has proven successful in identifying new cause of asthma and identifying workplaces with a high prevalence of workers with respiratory symptoms who may benefit from public health interventions.

Adult↗
PubMed1997

Silicosis in the 1990s.

OBJECTIVE: To describe state-based surveillance for silicosis that estimates prevalence of this condition, describes characteristics of affected individuals, and targets public health interventions. DESIGN: The data presented are a case series of patients with silicosis reported to a state health department. Patients were interviewed using a standardized questionnaire, chest radiographs interpreted by a "B-reader," pulmonary function tests obtained from medical records, and follow-back investigations conducted at the worksites where the cases had been exposed to silica. SETTING: All individuals with silicosis in the state of Michigan reported to the Michigan Department of Public Health (MDPH). SUBJECTS: Individuals included in this article were reported from 1987 through 1995. Cases were reported by hospitals, physicians, the state workers' compensation bureau, or from death certificates. Only data on individuals who met the criteria for silicosis developed by the National Institute for Occupational Safety and Health (NIOSH) are included. RESULTS: Between 1987 and 1995, 577 people were reported to MDPH who met the NIOSH criteria for silicosis. About 60% of the reports came from hospitals. The disease is occurring mainly among men born before 1940 who began working in a Michigan ferrous foundry in the 1930s or 1940s and worked there > 20 years. Over 40% of the patients are black. The overall annual average incidence rate of silicosis among black men (14.3 cases per 100,000) is seven times higher than among white men (2.1 cases per 100,000). The individuals identified with silicosis generally have severe disease. Almost 30% have progressive massive fibrosis and another 31.7% have advanced simple silicosis. Only about a third of all patients have normal results of breathing tests. Thirteen percent had been told they had tuberculosis (includes both clinical disease and a positive skin test). They have an increase of over 300% in the likelihood of dying of nonmalignant respiratory disease, both restrictive and obstructive, and an 80% increase in the likelihood of dying of lung cancer. Despite the severity of disease, over 45% of the individuals had not applied for workers' compensation. Although silicosis typically occurs after a long duration of exposure to silica, some individuals developed silicosis after a relatively short time. Three people developed silicosis who began working with silica in the 1980s, 18 in the 1970s, and 66 in the 1960s. Initial industrial hygiene follow-up inspections where the individuals had worked showed ongoing exposure above recommended and/or legal levels. Repeated inspections to these same facilities have subsequently shown reductions in silica exposure. CONCLUSION: This state-based surveillance system has proved useful in characterizing individuals with silicosis, estimating its prevalence, increasing the medical community's awareness of the condition, and targeting effective public health interventions.

Aged↗
PubMed1996

Silicosis among foundry workers. Implication for the need to revise the OSHA standard.

To evaluate the risk of pneumoconiosis among workers in a Midwestern automotive foundry, medical records and silica sand exposure data were analyzed for 1,072 current and retired employees with at least 5 years of employment as of June 1991. Approximately half of these employees had worked at the foundry for 20 or more years. Sixty workers were found to have radiographic evidence of pneumoconiosis. Twenty-eight workers had radiographs consistent with silicosis, of which 25 were consistent with simple silicosis and three with progressive massive fibrosis. The prevalence of radiographic changes consistent with silicosis increased with: number of years worked at the foundry (6% for 20-29 years and 12% for 30 or more years); cigarette smoking (12.2% among smokers with high silica exposure vs. 4.4% among never smokers with high silica exposure); work area within the foundry (cleaning room, core room, mold area, core knockout); and quantitative silica exposure (0.3-2.7% of workers at the current Occupational Safety and Health Administration (OSHA) standard and 4.9-9.9% of workers above the OSHA standard). In addition, the odds of developing radiographic changes consistent with silicosis were increased for African Americans (odds ratio = 2.14, 95% confidence interval 0.85-5.60) in comparison with whites. (The risk was similar when silica exposure was equal, but African-American workers on average had greater exposure to silica, despite having a similar duration of work as white workers.) Another eight workers had radiographic evidence of asbestosis, and 24 had pleural plaques. These asbestos-related changes were not associated with increasing exposure to silica but rather were associated with being in the maintenance department and performing repair work. After controlling for cigarette smoking, race, and exposure to silica at another job besides the foundry, the authors found a 1.45 increased risk of developing a radiograph consistent with silicosis after 20 years of work at the current OSHA standard, and a 2.10 increased risk after 40 years of work at the current OSHA standard. On the basis of these findings, the authors recommend maintaining silica air levels no higher than the exposure level of 0.05 mg/m3 recommended by the National Institute for Occupational Safety and Health.

Black People↗