Amino acid sequence of glutathione S-transferase rGSTM5* from rat testis

Glutathione S-transferase rGSTM5* was isolated from rat testis with a combination of glutathione affinity column and reverse-phase column chromatography. The protein was digested with Achromobacter protease I or endoproteinase Arg-C. The peptide fragments were isolated for electrospray MS and N-terminal peptide sequencing analyses. The primary amino acid sequence of rGSTM5* comprises 217 residues and has a calculated average molecular mass of 25495.3 Da. The result is identical to that obtained for rGSTM5* with liquid chromatography-MS from a mixture of rat testicular GSTs. Therefore, rGSTM5* has not been post-translationally modified.

Medical surveillance for hematological disorders among active and retired oil refinery workers

Ten-year (1985-1995) results of an expanded medical surveillance program of 2475 active employees and retirees of an oil refinery and petrochemical complex in Illinois are presented. At the end of the program, 116 participants with persistent abnormalities of complete blood cell count had been referred for hematologic evaluation, and most were found to have benign conditions. Fifteen of the 116 were referred for bone marrow and cytogenetic studies. All of the referred active employees (seven) were found to have completely normal bone marrows with no evidence of any myelopathic process. Among the eight retirees, two had normal bone marrows, one was diagnosed with Philadelphia chromosome-positive chronic myelogenous leukemia, one declined to participate, and four were diagnosed to have myelodysplastic syndrome (MDS) of various subtypes. A total of eight cases of MDS were identified, including six cases among program participants and two cases among nonparticipants. The MDS standardized incidence ratio of 1.26 (95% confidence interval = 0.54-2.47) was not statistically significant, and there was virtually no increase of MDS in persons less than 80 years of age (4 observed and 3.8 expected). This MDS increase was entirely from program participants, probably because of intensive follow-up and diagnostic screening. Routine surveillance of complete blood cell count information did not identify any new cases of leukemia or MDS in active employees. These findings suggest that the utility of expanded medical surveillance program in this population is very limited.

Illness absence at an oil refinery and petrochemical plant

Results from a prospective illness-absence surveillance of refinery and petrochemical workers from 1986 through 1994 are presented. Illness absence data for this study were extracted from the morbidity section of the Shell Oil Company's Health Surveillance System, which includes records of all illness absences in excess of 5 days. The majority of employees (59%) had no illness absence during the 9-year period studied. The 13% of the population who had three or more absences accounted for 63% of the total illness absence episodes and 62% of the total work days lost. Frequency rate and duration of absence increased with increasing age. The increased illness absence was associated with the presence of known health risk factors, such as smoking, elevated blood pressure, high cholesterol, and obesity. For example, obese women had a twofold increased illness absence rate compared with nonobese women and the rate for male smokers doubled that of nonsmoking men. These health risk factors are also more common among employees with three or more absences than those with fewer or no absences. The goal of this analysis is to quantify the impact of illness absence to develop disease prevention strategies to maximize good health in employees and to minimize both the frequency and duration of illness absence.

A mortality study of oil refinery and petrochemical employees

Results from a prospective mortality surveillance of 3803 refinery and petrochemical workers at a Shell Oil Company facility in Louisiana are presented. This report includes employees who worked more than 6 months before January 1, 1994 and pensioners who were alive as of January 1, 1973. Vital status was ascertained through 1993. Regardless of the comparison population used to calculate expected numbers (United States, Louisiana, or the surrounding tri-parish area), significantly fewer deaths were observed for all causes combined, all malignant neoplasms, heart disease, nonmalignant respiratory disease, and cirrhosis of the liver among male employees after 10 or more years' latency. With the United States as comparison, the all causes combined standardized mortality ratio (SMR) was 0.72 (95% confidence interval [CI] = 0.65 to 0.79), and the SMR for all cancer was 0.75 (95% CI = 0.61 to 0.92). The brain cancer rate for this group was nonsignificantly increased, with five observed deaths and three expected deaths, whereas mortality from leukemia was consistently lower than expected. The overall favorable mortality experienced by employees at this refinery and chemical plant is probably a result of a combination of factors, such as the healthy worker effect, relatively low risks related to the workplace, and the beneficial effects of continuing employment.

Mass spectrometric analysis of rat ovary and testis cytosolic glutathione S-transferases (GSTs): identification of a novel class-alpha GST, rGSTA6*, in rat testis

Cytosolic glutathione S-transferases (GSTs) from rat ovaries and testis were purified by a combination of GSH and S-hexylglutathione affinity chromatography. The isolated GSTs were subjected to reverse-phase HPLC, electrospray MS and N-terminal peptide sequencing analysis. The major GST isoenzymes expressed in ovaries are subunits A3, A4, M1, M2 and P1. Other isoenzymes detected are subunits A1, M3 and M6*. In rat testis, the major GST isoenzymes expressed are subunits A3, M1, M2, M3, M5* and M6*. Subunits A1, A4 and P1 are expressed in lesser amounts. We could not detect post-translational modifications of any GSTs with known cDNA sequence. The molecular masses of subunits M5* and M6*, two class-Mu GSTs that have not been cloned, were determined to be 25495 and 26538 Da respectively. An N-terminally modified protein from rat testis with molecular mass 25737 Da was isolated from the S-hexylglutathione column. Results from internal peptide sequencing analysis indicate that this is a novel class-Alpha GST that has not been previously reported. We designate this protein rGSTA6*.

Impact of HIV/AIDS on life expectancy in the United States

OBJECTIVES

The potential gains in life expectancy of the US population by the partial and total elimination of deaths from HIV/AIDS were compared with that of deaths from heart disease and malignant neoplasms.

METHODS

The data from the 1992 advanced mortality report and detailed information provided by the National Center for Health Statistics were analysed by using the partial multiple decrement life-table technique.

RESULTS

For the total population of the United States in 1992, the gains in future life expectancy through the elimination of deaths from HIV/AIDS, heart disease and malignant neoplasms were 0.34, 3.25 and 3.21 years, respectively. The gains in life expectancy in those of working age 15-64 years) through the elimination of deaths from these three causes of deaths were 0.20, 0.40 and 0.55 years, respectively. Race/sex-specific calculations indicate that the total elimination of deaths from HIV/AIDS, heart disease and malignant neoplasms in white men of working age resulted in increased life expectancy of 0.28, 0.54 and 0.53, respectively, whereas the corresponding figures for black men were 0.82, 0.90 and 0.76 years, respectively. Although the impact of the elimination of the other causes remained relatively stable from 1987 to 1992, the potential gains in life expectancy for black men of working age by eliminating HIV/AIDS rose from 0.36 years in 1987 to 0.82 years in 1992. For the total US population of working age, the elimination of HIV/AIDS deaths resulted in increased life expectancy similar to that observed for a 50% reduction of heart disease or malignant neoplasms, whereas among black men of working age, the increased years of life expectancy from the elimination of HIV/AIDS deaths were virtually the same as those observed for the elimination of heart disease or malignant neoplasms.

CONCLUSIONS

The potential gains in life expectancy by reduction of deaths from heart disease and malignant neoplasms are more heavily influenced by increasing years after the working ages (15-64 years), whereas the potential gains in life expectancy by reducing deaths from HIV/AIDS make a greater contribution to those of working age. Hence, in terms of the economic costs and benefits, these results indicate that in evaluating policy issues regarding allocation of research funds, studies of life expectancy are far more important than the simple approach which allocates funds on the basis of the number of deaths due to various diseases.

Managed care for workers' compensation: three years of experience in an "employee choice" state

Managed care techniques are becoming increasingly available to manage the medical indemnity losses associated with injuries paid for under the workers' compensation system. The authors describe 3 years' experience of identifying and abating workplace hazards and medically managing cases utilizing a preferred provider organization established solely for workers' compensation cases. In the model described, the occupational physician/nurse case-management team coordinates the entire process, from prevention of accidents to facilitated return to work. During the study period (1992 to 1995), per-capita losses were reduced by 23%, from $241 in fiscal year 1992 (the year before the managed care initiative), to $185 in fiscal year 1995. (Hereafter, each year referred to indicates that fiscal year.) In 1992, 22 lost-time cases per 1000 employees occurred, whereas the number of lost-time cases in the years 1993 to 1995 averaged 12 to 14 per 1000 employees. The rate of "medical only" cases dropped significantly from 155 per 1000 in 1992 to 96 per 1000 in 1995. The per-capita amount of monies spent on medical care decreased from $81 in 1992 to $63 in 1995. The most significant savings in medical costs related to claims associated with new occupational injuries, injuries that occurred during the fiscal year. In 1992, the per-capita loss on such cases was $23 and in 1995 it was $13, a 43% decrease. The number of temporary/total days dropped significantly from 163 per 100 employees in 1992 to 70 days in 1995. Concurrently, the per-capita loss for temporary total disability was reduced from $53 in 1992 to $26 in 1995. Per-capita administrative costs, as well as other indemnity losses (predominantly permanent partial disability), decreased only slightly over the study period ($58 to $54 and $60 to $51, respectively). We feel that these results indicate that environmental-risk management and medical-care management can be integrated to produce substantial savings. It also suggest that managed-care techniques, which are becoming more available to employers, can even be applied in status that do not have managed care legislation.

Enhancement of erythrocyte sedimentation rate by polymerized hemoglobin

Development of hemoglobin-based blood substitutes requires the scrutiny of blood rheological parameters that could be influenced by this class of molecules. Accordingly, we have examined the effects of glutaraldehyde-polymerized human hemoglobin on the erythrocyte sedimentation rate (ESR). For this purpose, human hemoglobin (Hb) was polymerized by glutaraldehyde, and its progress was monitored by gel permeation. ESR was measured by addition of hemoglobin or polymerized Hb (Poly-Hb) to citrated rat whole blood. The results indicate that, whereas Hb exerted minimal perturbation of ESR, Poly-Hb obtained under some polymerization conditions induced an over fifty-fold elevation of ESR. When polymerized Hb was fractionated by size, and different fractions were tested for their effects on ESR, a sharp dependence of ESR enhancement on molecular size of polymerized Hb was found. These observations suggest that ESR enhancement is mediated by macromolecular bridging formed by Poly-Hb of an adequate length between the surfaces of two stacking erythrocytes.

Mortality study of employees with potential exposure to epichlorohydrin: a 10 year update

OBJECTIVES

A 10 year extension of follow up (up to 1993) of 863 employees who had potential exposure to epichlorohydrin at two chemical plants between May 1948 and December 1965 was conducted to further evaluate the previously reported potential association between exposure to epichlorohydrin and heart disease.

METHODS

The mortality observed was compared with that expected from the death rates from the local male population where these chemical plants are located. Workers were assigned to one of five exposure categories based on their job with the highest level of potential exposure. Vital status was ascertained to the end of 1993.

RESULTS

Among diseases of particular interest, there were no excess deaths from heart disease (standardised mortality ratio (SMR) 63.3), lung cancer (SMR 63.8), or non-malignant respiratory disease (SMR 37.7) for employees with 20 or more years after first exposure. Based on the level of potential exposure to epichlorohydrin, mortality for heart disease was slightly higher (SMR 75.7, 95% confidence interval (95% CI) 51.8-106.7) in the moderate to heavy exposure group than in the none to light exposure group (SMR 59.5, 95% CI 37.7-89.3); this difference is well within the range of random variation. The SMR for heart disease was 90.4 among employees who had both probable exposure to allyl chloride and moderate to heavy exposure to epichlorohydrin, although it was 88.1 among employees who had moderate to heavy potential exposure to epichlorohydrin but no exposure to allyl chloride.

CONCLUSIONS

This study does not support an association between exposure to epichlorohydrin and heart disease or lung cancer. There were no additional deaths from leukaemia in this update; the raised SMR for leukaemia noted in the previous study has substantially decreased from 500.0 to 161.3 (95% CI 33.2-471.0) and is not significant. The overall mortality and cancer mortality of employees potentially exposed to epichlorohydrin continued to be lower than that of the local population.

Statistical analysis of the standardized mortality ratio and life expectancy

A new theoretical relation that does not require the constant age-specific mortality ratio assumption is established between the standardized mortality ratio (SMR) and the life expectancy. A set of regression equations is developed from the theoretical relation to derive estimates of the future expectation of life from estimates of the SMR. Curves are presented showing the changes in life expectancy that are associated with a given SMR for individuals aged 25, 45, and 65 years. These results will provide practical applications in estimating remaining life expectancy in epidemiologic studies in which the SMR is the summary statistic. An application is shown for studies in occupational health to develop and illustrate the method.

The 30 kDa protein co-purified with chick liver glutathione S-transferases is a carbonyl reductase

An unidentified 30 kDa protein was co-purified with chick liver glutathione S-transferases from S-hexylglutathione affinity column. The protein was isolated to apparent homogeneity with chromatofocusing. The molecular mass of the protein was determined to be 30 277 +/- 3 dalton by mass spectrometry. The protein was digested with Achromobacter proteinase I. Amino-acid sequence analyses of the resulting peptides show a high degree of identity with those of human carbonyl reductase. The protein is active with menadione as substrate. Thus, it is identified as chick liver carbonyl reductase.

Mortality among maintenance employees potentially exposed to asbestos in a refinery and petrochemical plant

This paper reports the mortality experience from 1948 to 1989 of 2,504 maintenance employees who had a minimum of one year of employment in jobs with potential exposure to asbestos at a Texas refinery and petrochemical plant. For the purposes of this study, "potential exposure" is equated with those jobs or crafts having the greatest direct potential proximity to, or which worked directly with, asbestos-containing materials, especially asbestos-containing thermal insulation. Approximately one-half of the study population had 10 years or longer potential exposure, and 80% had their first potential exposure before 1970. The total population exhibited significantly lower mortality for all causes, the standardized mortality ratio (SMR = 77); and for all cancer (SMR = 85), as compared to residents in the surrounding communities. Statistically significant deficits in mortality were also observed in a number of noncancerous diseases such as heart disease (SMR = 78; 95% CI = 69-88), nonmalignant respiratory disease (SMR = 70; 95% CI = 50-95), and cirrhosis of the liver (SMR = 44; 95% CI = 22-79). Mortality among employees who had 20 years or longer since their first potential exposure was also examined; the pattern of mortality was similar to that exhibited by the total cohort, with a slight increase in the SMR for most of the causes. The only statistically significant excess of mortality found was a fourfold increase in mesothelioma (5 observed and 1.2 expected deaths) the SMR was 428 (95% CI = 139-996) for the total cohort and was 469 (95% CI = 152-1093) for those who had 20 years or more since first potential exposure. In contrast to asbestos industry worker studies, mortality for lung cancer was substantially lower than the general population (SMR = 81; 95% CI = 63-103). The observed number of deaths for cancer of the larynx was virtually the same as expected (3 observed vs. 2.8 expected). This study also showed decreased mortality for cancers of gastrointestinal organs such as the esophagus (SMR = 78), stomach (SMR = 63), large intestine (SMR = 91), rectum (SMR = 55), or pancreas (SMR = 90)--cancers that have been reported to be elevated in studies of various industry workers directly exposed to asbestos.

Long-term follow-up mortality study of petroleum refinery and chemical plant employees

A previous report presented the 1948-1983 mortality patterns of the Shell Deer Park Manufacturing Complex employees who were employed for at least 3 months from 1948 through 1972. The present study updates the earlier investigation by extending the vital status follow-up through 1989 and by expanding the cohort to include employees hired after 1972. As in the previous study, the overall mortality and cancer mortality for both refinery and chemical employees were quite favorable compared to residents in the local population. Among refinery workers, cancers for which a suspicion of work-relatedness was raised in the previous study, i.e. leukemia and cancers of the central nervous system and biliary passage/liver, no supportive evidence was found in this update. For both refinery and chemical plant employees, the mortality rate due to cancers of all lymphopoietic tissue increased with increasing duration of employment; this finding was also noted by the original study. This was also evident for lymphoreticulosarcoma in refinery employees and for leukemia in chemical plant employees. However, elevations of cancers of all lymphatic and hematopoietic tissue are primarily confined to employees who started work at the complex before 1946. By contrast, deaths from cancer of all lymphatic and hematopoietic tissue for employees hired after 1945 were 22% lower than the comparison population. Seven deaths with mesothelioma mentioned on the death certificates were identified, with 3.2 deaths expected, resulting in a statistically nonsignificant SMR of 219.

Amino acid sequencing, molecular cloning and modelling of the chick liver class-theta glutathione S-transferase CL1

Glutathione S-transferase CL1-2 heterodimers purified from 1-day-old chick livers were digested with Achromobacter proteinase I. The resulting fragments were separated for amino acid sequence analysis. Oligonucleotide probes were constructed based on sequence similarity to class-Theta glutathione S-transferases for PCR using a chicken liver cDNA library as template. A full-length clone (1725 bp) encoding a polypeptide comprising 261 amino acids was isolated. Including conservative substitutions, this protein has 70-73% sequence similarity with other mammalian class-Theta glutathione S-transferases. Based on known X-ray crystal structures of class-Alpha, -Mu and -Pi glutathione S-transferases, a model is constructed for the N-terminal 232 residues of CL1.

A comprehensive initiative to manage the incidence and cost of occupational injury and illness. Report of an outcomes analysis

A comprehensive initiative utilizing an in-house preferred provider organization, medical case management, and application of ergonomic techniques was implemented in an effort to control the incidence and cost of workplace injuries. The program was evaluated utilizing OSHA 200 Logs to compare the incidence and lost time due to compensable injury and illnesses before and after beginning the program. After the introduction, there was a significant decrease in injuries and illnesses (53/1000 vs 27/1000, P<.01) and average days lost per event (10.4 vs 6.6 days, P<.01). A significant increase in restricted-duty days (.2 vs 1.5 days, P<.01) and an 18% reduction in medical and indemnity costs of the institution's workers' compensation expenditures were observed. This study demonstrates the initial effectiveness of an aggressive ergonomic and managed care approach to reducing the incidence, severity, and cost of occupationally related injury and illness. It also highlights the effectiveness of an outcomes analysis approach, using lost time as an end point, to measure the effectiveness of preventive and management strategies in the workers' compensation setting.

Mass spectrometric analysis of rat liver cytosolic glutathione S-transferases: modifications are limited to N-terminal processing

Cytosolic glutathione S-transferases (GSTs) from rat livers were purified using an S-hexylglutathione affinity column. The GST subunits were resolved by reverse-phase HPLC and their molecular masses were determined by electrospray mass spectrometry. The major hepatic GSTs detected were subunits 1, 1', 2, 3 and 4, with molecular mass of 25,520, 25,473, 25,188, 25,782 and 25,571 Da respectively. Subunits 6, 7 and 10 are minor components, with molecular mass of 25,551, 23,308 and 25,211 Da respectively. Alternatively, the hepatic GSTs were purified using a glutathione affinity column. Subunits 1, 1', 2, 8 and 10 were eluted from this column with GSSG, the oxidized form of glutathione. Subunit 8 has a molecular mass of 25,553 Da. The remaining proteins on the glutathione affinity column were removed with glutathione and S-hexylglutathione. Subunits 2, 3, 4 and 6 could be detected in the eluate. We could not detect any significant difference in molecular mass between GSTs isolated from male and female rat livers. Cytosolic GSTs were isolated from livers of buthionine sulphoximine-treated female rats for MS analysis. The molecular masses obtained were identical to those determined for the controls.

Cloning of AL-1, a ligand for an Eph-related tyrosine kinase receptor involved in axon bundle formation

REK7 is an Eph-related tyrosine kinase receptor expressed exclusively in the nervous system, predominantly in hippocampus and cortex. A soluble REK7-IgG fusion protein, produced to analyze the biological role of REK7, prevents axon bundling in cocultures of cortical neurons with astrocytes, a model of late stage nervous system development and differentiation. Using REK7-IgG as an affinity reagent, we purified and cloned a novel REK7 ligand called AL-1, a GPI-linked protein homologous to other members of an emerging ligand family. Membrane attachment of AL-1 appears necessary for receptor activation, since REK7 on cortical neurons is efficiently activated by transfected cells expressing GPI-linked AL-1, but not by soluble AL-1. Consistent with this, soluble AL-1 blocks axon bundling. Our findings, together with the observation that both molecules are expressed in the brain, suggest a role in the formation of neuronal pathways, a crucial feature of nervous system development and regeneration.

[Current clinical approaches and gene mutation study of beta-thalassemia major]

Forty-one cases of beta-thalassemia major were assessed for their clinical manifestations and gene mutation. The age distribution was from 1 to 18 years old. Patient's initial clinical symptoms began mostly before 2 years of age (90.2%). Patient's initial hematological data included mean hemoglobin value, 5.8 +/- 1.2 gm/dl, hemoglobin F value, 85.0 +/- 12.1%, hemoglobin A2 value 2.3 +/- 1.8%, reticulocyte count 9.2 +/- 9.0%. Eight different point mutations were characterized. Of these mutations, C to T substitution at nucleotide (nt) 654 of intervening sequence (IVS) 2, accounting for 46.3% of mutant beta-globin genes, is the most common mutation in our series, followed by frameshift codons 41/42 with a four nucleotides (TCTT) deletion for 31.7%; A to G substitution at position -28 of the promotor area for 8.5%; A to T substitution at codon 17 for 6.1%; frameshift codons 27/28 (insertion of C) for 2.4%; G to T substitution at nucleotide 1 of IVS-1 for 2.4%; frameshift codons 71/72 (insertion of A) and IVS-1 3' end TAG-->GAG for 1.2%. The first four mutations account for 92.6% of all beta-globin gene mutations in our series. As to mutations in each individual, the incidence of compound heterozygotes of two different mutations is much higher than homozygotes of a single mutation, 78.0% vs. 22.0%. Compound heterozygotes of C to T substitution at nt 654 of IVS-2 and frameshift codons 41/42 with a four nucleotides deletion is the most common pattern of beta-thalassemia mutation in our patients (41.5%). Patients with beta(0)/-28 beta(+) compound heterozygote mutation had much delayed initial symptoms than beta (0)/beta(0) homozygote mutation, but clinical manifestation may be aggravated when the mutation combined with glucose-6-phosphate dehydrogenase deficiency. Severity of iron overload was significantly correlated with total transfusion amount and patient's age in simple regression analysis (p < 0.001). Splenectomy may effectively prolong transfusion interval, maintain higher hemoglobin level before each transfusion and palliate clinical symptoms (p < 0.01). Iron-chelating agent therapy can effectively lower the total amount of serum ferritin. Higher severity of iron overload correlates with higher incidence of EKG and cardiac abnormalities in patients with beta-thalassemia major.

Modification of glutathione S-transferase 3-3 mutants with 2-(S-glutathionyl)-3,5,6-trichloro-1,4-benzoquinone. Identification of the C-terminal tryptic fragment as part of the H-site and evidence that 2-(S-glutathionyl)-3,5,6-trichloro-1,4-benzoquinone is not specific for cysteine labelling

A triple mutant of rat liver glutathione S-transferase 3-3 that has all three cysteine residues replaced with serine (CallS) and a quadruple mutant with a Tyr-115 to phenylalanine substitution on CallS (CallSY115F) were reacted with 2-(S-glutathionyl)-3,5,6-trichloro-1,4-benzoquinone (GS-1,4-TCBQ). The modified proteins were analysed on a triple-quadrupole mass spectrometer equipped with an electrospray ionization source. At an enzyme: GS-1,4-TCBQ ratio of 1:10, the enzymes were modified at multiple sites. Covalent attachment of a single inhibitor on to the protein was achieved by lowering the enzyme: GS-1,4-TCBQ ratio to 1:1. Results from m.s. analyses suggest that the inhibitor on the CallSY115F mutant exists as a glutathionyl dichlorobenzoquinone derivative. The modifiers of the CallS mutants are glutathionyl monochlorobenzoquinone derivatives. Therefore, GS-1,4-TCBQ reacts at a single site on CallSY115F, but probably cross-links two regions on wild-type and CallS mutant. To confirm our observation, CallS was modified with 1-chloro2,4-dinitrobenzene, which specifically labels Tyr-115, before reacting with GS-1,4-TCBQ. The inhibitor formed a glutathionyl dichlorobenzoquinone adduct on the dinitrophenyl-CallS mutant. In addition, the benzoquinone derivative on the protein can be partially removed by 1-chloro-2,4-dinitrobenzene. Peptide mapping and sequencing analysis of the GS-1,4-TCBQ-modified CallS mutant revealed that the C-terminal 16-amino-acid fragment is labelled. Molecular modelling suggests the C(5) and C(6) on the benzoquinone ring of the inhibitor interact with the oxygen atoms of Tyr-115 and Ser-209 respectively.

Mortality among employees at a plastics and resins research and development facility

OBJECTIVES

The study was undertaken to update a previous study of employees from a resins and plastics research and development facility and to further examine the mortality of these employees with particular emphasis on deaths due to pancreatic cancer.

METHODS

This retrospective cohort study examined mortality from 1962 to 1992 for 257 men who were employed for at least one year during a 14 year period from 1962 to 1975 at a plastics and resins research and development facility. During the operative period, the primary activities involved applications and process development for polypropylene, polystyrene, epoxy resins, and to a lesser extent high density polyethylene.

RESULTS

The cohort was young and was followed up for an average of 26 years. Although mortality for all causes among employees who worked at least one year at this facility was low (standardised mortality ratio (SMR) 0.74), the death rate from cancer was moderately higher than that of the general population (14 observed and 9.4 expected deaths). There were four observed and 0.5 expected deaths from pancreatic cancer among men who worked at this facility for at least one year, which resulted in a statistically increased SMR of 8.88 (95% confidence interval 2.42-22.74). All cases of pancreatic cancer had "laboratory" jobs, and their ages at death were relatively young compared with deaths in the general population from pancreatic cancer. Lung cancer mortality was high but not significant with seven observed and 3.5 expected deaths. There were no deaths due to non-malignant respiratory disease (1.9 expected).

CONCLUSIONS

The increased cancer mortality was entirely due to excess deaths from pancreatic and lung cancers. No causative agent or process for these cases of pancreatic cancer has been identified. This study shows no increased colorectal cancer mortality as was found among another group of workers involved in the manufacture of polypropylene.

The health impact of cigarette smoking in Taiwan

This study examined mortality attributed to active and passive smoking in Taiwan for the years 1981 and 1990. It was estimated that 19,283 deaths, representing 19% of the total number of deaths in 1990 (almost one out of five deaths in Taiwan), were smoking related. On an average day, 53 people died as a result of cigarette smoking, including 13 deaths from passive smoking. More men died (14,140 deaths) from smoking-related causes than from all cancer deaths combined (13,161 deaths); 91% of lung cancer and 30% of all cancers were due to smoking. In comparison, the smoking attributable mortality was much less for women, with 5,143 deaths. In addition, almost 5,000 deaths can be attributed to passive smoking every year in Taiwan with more deaths from women than from men. The overall prevalence rates for cigarette smoking has changed little in the last 20 years; approximately 60% for men and 4% for women although a consistent increase of one million new smokers was added every decade. Among younger people, the rate increased substantially, while it dropped 10-15% among middle-aged and older persons. Smoking is the largest single source of health risk in Taiwan. It is crucial that strategies to prevent smoking initiation among young people be developed so that the most vulnerable group can receive immediate attention. Despite the recent aggressive smoking cessation campaign by the Department of Health, much work remains. In order to facilitate this work, it is therefore recommended that the government commit to a goal of smoke-free nation by the year 2010.

Mortality, morbidity, and haematological results from a cohort of long-term workers involved in 1,3-butadiene monomer production

A retrospective mortality analysis and prospective morbidity and haematological analyses were performed for Shell Deer Park Manufacturing Complex (DPMC) male employees who worked in jobs with potential exposure to 1,3-butadiene from 1948 to 1989. 614 employees qualified for the mortality study (1948-89), 438 of those were still employed during the period of the morbidity study (1982-9), and 429 of those had haematological data available for analysis. Industrial hygiene data from 1979 to 1992 showed that most butadiene exposures did not exceed 10 ppm (eight-hour time weighted average (8 hour TWA)), and most were below 1 ppm, with an arithmetic mean of 3.5 ppm. 24 deaths occurred during the mortality study period. For all causes of death, the standardised mortality ratio (SMR) was 48 (95% confidence interval (95% CI) = 31-72), and the all cancer SMR was 34 (95% CI = 9-87). There were only two deaths due to lung cancer (SMR 42, 95% CI = 5-151) and none due to lymphohaematopoietic cancer (expected = 1.2). Morbidity (illness absence) events of six days or more for the 438 butadiene employees were compared with the rest of the complex. No cause of morbidity was in excess for this group; the all cause standardised morbidity ratio (SMbR) was 85 (95% CI = 77-93) and the all neoplasms SMbR was 51 (95% CI = 22-100). Haematological results for the 429 with laboratory data were compared with results for the rest of the complex. No significant differences occurred between the two groups and the distributions of results between butadiene and non-butadiene groups were virtually identical. These results suggest that butadiene exposures at concentrations common at DPMC in the past 10-20 years do not pose a health hazard to employees.

Reversible modification of rat liver glutathione S-transferase 3-3 with 1-chloro-2,4-dinitrobenzene: specific labelling of Tyr-115

Rat liver glutathione S-transferase 3-3 (GST, EC 2.5.1.18), a triple mutant with all three cysteine residues replaced with serine (CallS) and a quadruple mutant with a Tyr-115 to phenylalanine substitution on CallS (CallSY115F) were overexpressed in Escherichia coli under the control of a phoA promoter. Using this system, we obtained over 35 mg of fully active pure protein/litre of cell medium. GST 3-3 and CallS mutant were modified with 1-chloro-2,4-dinitrobenzene (CDNB), a model substrate for the enzyme, in the absence of GSH. Dinitrophenol, but not S-methylglutathione, inhibits this process. The dinitrophenyl groups are readily removed from the enzyme with GSH, but much more slowly with dithiothreitol. Results from peptide mapping and amino acid sequence analyses indicate that CDNB modifies the cysteine residues and Tyr-115 on wild-type GST 3-3, but only Tyr-115 on CallS. In addition, CDNB cannot modify the CallSY115F mutant. We propose that Tyr-115 is located at or near the H-site of GST 3-3.

A cohort mortality study of two California refinery and petrochemical plants

This study examined the 1973 to 1989 mortality experience of Shell's two California manufacturing locations' employees who worked more than 6 months before December 31, 1989 and pensioners who were alive as of January 1, 1973. Vital status of each employee as of December 31, 1989 was determined from various sources including company records, the National Death Index, and the Social Security Administration's Master Beneficiary Record file. The study included many long-term employees, with more than half (57%) of the total population working 20 years or longer. The total population exhibited 11% lower all causes mortality and 20% lower cancer mortality, as compared with the California general population. There were no significant excesses of any cause-specific mortality including cancer. Among total employees, mortality for several cancer sites showed a statistically nonsignificant increase, for example, cancer of the kidney (8 observed deaths and 6.02 expected), cancer of the bladder (11 observed deaths and 9.17 expected), and Hodgkin's disease (2 observed deaths and 1.01 expected). A review of these work histories revealed no predominant work area or job assignment. In contrast to the ecologic studies based on local county rates, lung cancer mortality in this study was significantly lower (Standardized Mortality ratio [SMR] = 0.73). In addition, statistically significant deficits in mortality were found for cirrhosis of the liver (SMR = 0.63) and all external causes of death (SMR = 0.74). This study also failed to show an increased mortality rate for cancers of the brain, stomach, and prostate--causes which have been reported to be elevated in other refinery and petrochemical employee studies.

Site-directed mutagenesis and chemical modification of cysteine residues of rat glutathione S-transferase 3-3

Rat liver glutathione S-transferase (GST) 3-3 is composed of two identical subunits, each containing three cysteine residues, Cys-86, Cys-114 and Cys-173. We have shown previously that Cys-86 is not involved in the enzymic activity of GST 3-3 [Hsieh, Huang, Chen, Lai & Tam (1991) Biochem, J. 278, 293-297]. At 50 degrees C, iodoacetamide can inactivate the enzyme by modifying Cys-86 and Cys-114. Cys-114 can be protected against iodoacetamide inhibition by S-(dinitrophenyl)glutathione. Site-directed mutagenesis was used to construct mutants in which serine replaced one (C114S and C173S) or all three (CallS) cysteine residues. These mutants were over-expressed in Spodoptera frugiperda cells in a baculovirus system and were found to be fully active. Replacing Cys-86 or Cys-114 with alanine (C86A and C114A) does not diminish the activity of the protein. The results suggest that cysteines are not involved in the enzymic mechanism, and Cys-114 is possibly located at the active site of GST 3-3.

Personal and job characteristics of musculoskeletal injuries in an industrial population

A cross-sectional study was conducted of 10,350 full-time regular employees who worked at Shell Oil Company's manufacturing facilities between 1987 and 1989. Two hundred seventy-five employees with low-back and 456 with nonlow-back musculoskeletal injuries were compared with 8295 employees who did not have musculoskeletal injuries during this period. Based on morbidity data collected from a prospective health surveillance system, this study shows that estimated relative risks (RRs) for low-back injuries are significantly higher among smokers (RR = 1.54, P less than .01) and overweight persons (RR = 1.42, P less than .01). This observation is also true for nonlow-back musculoskeletal injury (RR = 1.23, P = .05 for smokers and RR = 1.53, P less than .01 for overweight persons). In addition, persons in potentially more physically demanding jobs (primarily maintenance job titles) had an increased RR for both low-back and nonlow-back musculoskeletal injuries (RR = 1.57, P less than .01 and RR = 1.35, P = .02, respectively). The findings of this study suggest that it may be possible to reduce the impact of musculoskeletal injury through implementation of an integrated injury prevention program. Such programs would include not only the traditional elements of job factors evaluation and modifications, employee education and training, and an overall increased attention to ergonomics but also medical counseling and support for personal fitness programs, workplace smoking cessation programs, and weight-reduction programs.

The standardized mortality ratio and life expectancy

This paper develops a theoretical relation between the standardized mortality ratio (SMR) and the expected years of life and establishes a regression equation for easy conversion between these two statistics. The mathematical expression of the derived relation is an approximation, requiring an assumption of constant age-specific mortality ratios. It underestimates the "true" value calculated based on life table technique when the age-specific mortality ratios increase with age. This equation provides a conservative method to estimate the expected years of life for cohort mortality studies and facilitates an assessment of the impact of work-related factors on the length of life of the worker. It also allows one to convert the SMR to life expectancy in smaller studies whose sole objective is to determine the SMR in a working population. A 1% decrease (or increase) in the standardized mortality ratio will result in 0.1373 years increased (or decreased) life expectancy based on white male data for the US population. Furthermore, with data from 14 large oil refinery and chemical worker cohorts of white males, the "derived" expected years of life based on the regression equation closely predicts the corresponding value calculated using a standard life table technique. This statistical equation is expected to have practical applications when used in conjunction with the SMR to provide an approximate measure of life expectancy, a term and statistic familiar to most lay people.

Cloning and expression of a chick liver glutathione S-transferase CL 3 subunit with the use of a baculovirus expression system

Glutathione S-transferase CL 3 subunits purified from 1-day-old-chick livers were digested with Achromobacter proteinase I and the resulting fragments were isolated for amino acid sequence analysis. An oligonucleotide probe was constructed accordingly for cDNA library screening. A cDNA clone of 1342 bases, pGCL301, encoding a protein of 26209 Da was isolated and sequenced. Including conservative substitutions, this protein has 75-79% sequence similarity to other Alpha family glutathione S-transferases. The coding sequence of pGCL301 was inserted into a baculovirus vector for infection of Spodoptera frugiperda (SF9) cells. The expressed protein has a high relative activity with ethacrynic acid (47% of the specific activity with 1-chloro-2,4-dinitrobenzene). The enzyme has a subunit molecular mass of 25.2 +/- 1.2 kDa (by SDS/PAGE), a pI of 9.45 and an absorption coefficient A1%1cm of 13.0 +/- 0.5 at 280 nm.

Isolation, molecular cloning, and partial characterization of a novel carboxypeptidase B from human plasma

A novel plasminogen-binding protein has been isolated from human plasma utilizing plasminogen-Sepharose affinity chromatography. This protein copurified with alpha 2 antiplasmin when the plasminogen affinity column was eluted with high concentrations of epsilon-aminocaproic acid (greater than 20 mM). Analysis by sodium dodecyl sulfate suggests this protein has an apparent Mr of 60,000. The amino-terminal amino acid sequence showed no similarity to other protein sequences. Based on the amino-terminal amino acid sequence, oligonucleotide probes were designed for polymerase chain reaction primers, and an approximately 1,800 base pair cDNA was isolated that encodes this Mr 60,000 protein. The deduced amino acid sequence reveals a primary translation product of 423 amino acids that is very similar to carboxypeptidase A and B and consists of a 22-amino acid signal peptide, a 92-amino acid activation peptide, and a 309-amino acid catalytic domain. This protein shows 44 and 40% similarity to rat procarboxypeptidase B and human mast cell procarboxypeptidase A, respectively. The residues critical for catalysis and zinc and substrate binding of carboxypeptidase A and B are conserved in the Mr 60,000 plasminogen-binding protein. The presence of aspartic acid at position 257 of the catalytic domain suggests that this protein is a basic carboxypeptidase. When activated by trypsin, it hydrolyzes carboxypeptidase B substrates, hippuryl-Arg and hippuryl-Lys, but not carboxypeptidase A substrates, and it is inhibited by the specific carboxypeptidase B inhibitor (DL-5-guanidinoethyl)mercaptosuccinic acid. We propose that the Mr 60,000 plasminogen-binding protein isolated here is a novel human plasma carboxypeptidase B and that it be designated pCPB.

X/Y translocations resulting from recombination between homologous sequences on Xp and Yq

Several regions of sequence homology between the human X and Y chromosomes have been identified. These segments are thought to represent areas of these chromosomes that have engaged in meiotic recombination in relatively recent evolutionary times. Normally, the X and Y chromosomes pair during meiosis and exchange DNA only within the pseudoautosomal region at the distal short arms of both chromosomes. However, it has been suggested that aberrant recombination involving other segments of high homology could be responsible for the production of X/Y translocations. We have studied four X/Y translocation patients using molecular probes detecting homologous sequences on X and Y chromosomes. In one translocation the breakpoints have been isolated and sequenced. The mapping data are consistent with the hypothesis that X/Y translocations arise by homologous recombination. The sequencing data from one translocation demonstrate this directly.

Morbidity patterns among employees at a petroleum refinery

This study examined the morbidity experience of a prospective cohort of 2132 male employees who worked at a petroleum refinery from 1981 through 1988. The morbidity data included all illness-absence episodes in excess of 5 days during the study period. Standardized morbidity ratios (SMRs) of disease prevalence were calculated using data from all manufacturing employees of the Shell Oil Company as an internal comparison group. As such, there is no potential bias associated with the "healthy worker effect" in this type of study design. Morbidity for all causes combined was virtually the same as that for the comparison group with 2,311 observed and 2,318 expected disease prevalence events. However, there were statistically increased prevalence of musculoskeletal system disorders (SMR = 136) and injuries (SMR = 125) among staff employees and skin and subcutaneous tissue disorders (SMR = 138) among production employees. A review of the original morbidity reports for these skin conditions revealed that none were due to exposure to chemical products or solvents. The SMR for neoplasms of the lymphatic and hematopoietic tissue among production employees was slightly elevated but was based on only three cases (2.4 expected). Of the three cases, none was due to leukemia.

The relationship between work-related and non-work-related injuries

A case-control study of occupational injuries sustained by 914 male hourly workers employed in two Tenneco manufacturing divisions in 1987 was undertaken to examine the association between occupational and non-occupational injuries. Its aim was to evaluate whether employees who experienced a work-related injury were more likely to have sustained a previous non-work-related injury compared to individuals who did not experience a work-related injury. A statistically significant association between occupational injuries and past non-occupational injuries was seen when all workers compensation (WC) claims were analyzed (OR = 1.41) and when claims involving indemnity for lost time were analyzed (OR = 1.82). In addition, both workers who had occupational low-back injuries and workers who had occupational non-low-back injuries also had significantly higher risks of such injuries from a non-occupational origin (OR = 1.91 for low-back injuries and OR = 1.44 for non-low-back injuries). The findings suggest that elements other than workplace hazards (such as life-style and physical and psychological factors) may predispose an individual to both occupational and non-occupational injuries.

Health care utilization and costs for injury in a corporate setting

This article presents the incidence and costs for non-work-related injuries among 15,408 employees and their families based on health insurance claims data analysis. The treatment of injuries accounted for 11.3% of the plan's total health care costs ($31 million) for the 1986 policy year. For adults, women had a higher incidence rate than men; but for children, males had a higher incidence rate than females. A disproportionately high share of claims and charges for adults were attributed to low back disorders. Hospital admissions, length of stay and hospital days per 1,000 persons were similar for males and females, but much higher for adults than for children. This article provides an example of the utility of health insurance claims data as a source of morbidity information for disease surveillance and epidemiologic research. The analysis of claims data can be seen as a prerequisite to the development of preventive programs aimed at reducing injury rates and health care costs for injuries in a corporate setting.

Prospective morbidity surveillance of Shell refinery and petrochemical employees

Results for a prospective morbidity study of 14,170 refinery and chemical workers from 1981 through 1988 are presented. Illness/absence data for this study were extracted from the morbidity section of the Shell Health Surveillance System which includes records of all illness/absences in excess of five days. Age adjusted annual morbidity frequency rates and annual durations of absence are presented by age, sex, job, and work status. Generally, rates and durations of absence were highest for older age groups, women, and production workers. Increased risk was associated with the presence of known disease risk factors. Overall, 48% of the employees had at least one illness/absence in excess of five days during the eight year period. Twelve per cent of the employees had four or more absences, which accounted for 54% of the total number of absences and 52% of the total work days lost. Among men, the five most common conditions accounted for 72% of all illness/absences. In descending order they were injuries (25%), respiratory illnesses (17%), musculoskeletal disorders (14%), digestive illnesses (9%), and heart disease (7%). Similar patterns were noted among women. These findings may be useful in setting priorities and directing efforts such as health education programmes and other strategies for the prevention of disease.

Mortality trend in a rapidly developing economy in Taiwan. Part II: Life expectancy and "potential years of life lost"

Taiwan has made remarkable economic progress in the last 30 years. The life expectancy of its population improved steadily during this period. A male child born in 1983 could look forward to 70.4 years of life and a female child to 75.3 years, gains of 17.5 years and 19.0 years, respectively, since 1950. The potential gains in life expectancy of the Taiwan population are also examined if the five leading causes of death are reduced or eliminated. In addition, this paper discusses the concept of potential productive years of life lost (PYLL), examines the leading causes of premature death and shows how this measure can be used to target prevention programs and health care planning.

Morbidity prevalence study of workers with potential exposure to epichlorohydrin

This study examined the morbidity experience from 1981 to 1988 of two cohorts (Shell cohort and Enterline cohort) of workers who had potential exposure to epichlorohydrin (ECH). The morbidity prevalence data for this study were extracted from the morbidity section of the Shell health surveillance system which included all illness and absence records in excess of five days. For both cohorts, the standardised morbidity ratios (SMRs) for all causes and all neoplasms were similar to an internal comparison group. There were no increases in heart disease morbidity for the Shell cohort (SMR = 97) or the Enterline cohort (SMR = 90). The SMRs for heart disease in the lower exposure group of the Shell cohort were 101 and 93 for the corresponding Enterline cohort. They were 92 and 87, respectively, in the higher exposure group. The increased risk of heart disease mortality reported by Enterline et al in workers more heavily exposed to ECH was not confirmed in this morbidity study. Morbidity from skin and subcutaneous tissue disorders, however, was found to be increased significantly in the Shell cohort. The SMR was 98 for the lower exposure group and 195 for the higher exposure group. A review of the original morbidity reports for each case suggested that factors unrelated to exposure to ECH such as the physical demands of a particular job, amount of time outside--for example, exposure to poison ivy--and other underlying medical conditions may be of greater importance than exposure to ECH.

Frequent deletions of the human X chromosome distal short arm result from recombination between low copy repetitive elements

Substantial DNA deletions appear to be the molecular basis of several human genetic disorders but rarely account for the majority of observed mutations at any given locus. Exceptions in which deletions do account for the majority of observed abnormalities include the alpha-thalassemias, Duchenne muscular dystrophy, and steroid sulfatase deficiency. Variable deletion breakpoints have been recognized at the alpha-globin and dystrophin loci, but no information is available regarding STS deletions. We have found that these STS alterations usually involve breakpoints within highly similar sequence elements situated approximately 1.9 megabases apart on the X chromosome. It is surprising that these very large deletions produce such mild clinical abnormalities. These results may provide insight into the molecular mechanism of a number of human genetic defects.

Smoking and morbidity frequency in a working population

As part of Shell's health surveillance program, morbidity frequency and severity by smoking status (current smoker, exsmoker, nonsmoker) were compared for the 3-year period 1985 through 1987. Morbidity data for this study were extracted from the morbidity section of the Shell Health Surveillance System, which included all illness and absence events in excess of 5 days. Statistically significant positive associations were seen between smoking habits and overall morbidity, diseases of the circulatory system, and diseases of the respiratory system for both male and female employees. In addition, a significantly increased association between smoking and both non-motor vehicle accidents and motor vehicle accidents among current smokers was noted. Current smokers had a greater than 60% higher frequency rate (P less than .05) for non-motor vehicle accidents than nonsmokers for both men and women. Male smokers also had a 75% increased (P less than .05) motor vehicle accident rate. These results suggest that it may be possible to reduce overall illness and injury morbidity through implementation of successful smoking cessation programs.

Transformation in restriction-deficient Salmonella typhimurium LT2

Stable restriction-deficient, modification-proficient galE (JR501) and F'galE+ (JR502) strains of Salmonella typhimurium were constructed and the effects of restriction on transformation by plasmid pBR322 were tested. Several factors which affect transformation efficiency were systematically examined to determine optimum transformation conditions and a simplified method is presented.

Incidence and cost of injury in an industrial population

Using both occupational (workers' compensation) and non-occupational (group health insurance) data, the nature and magnitude of injuries were determined in a working population of 20,705. Approximately one third of the population sustained an injury in 1986 (the year of study). Men experienced a significantly higher injury rate than women (33.3 per 100 v 24.9 per 100) and hourly employees had significantly higher incidence rates than salaried employees (42.0 per 100 v 22.5 per 100). The majority of nonoccupational injury claims were for low back disorders, whereas most occupational injury claims were related to superficial wounds and contusions. Overall, the incidence of nonoccupational injuries (21.1 per 100) was twofold higher than that of occupational injuries (10.8 per 100). Total costs for occupational and nonoccupational injuries were $4.97 million. The per-capita costs were $120 for both nonoccupational and occupational injuries. However, if only health care expenses are included in this calculation, nonoccupational injury costs would be almost 3 times as high as occupational injury costs ($120 v $46). These findings argue for increasing the share of corporate resources for off-the-job injury prevention programs aimed at reducing injury incidence and resultant health care costs.

Mortality trends in a rapidly developing economy in Taiwan. Part I: Comparison with the USA and Japan 1976-1983

The mortality experience of Taiwan was examined for two time periods (1976 and 1983) to determine the magnitude and direction of change in age-adjusted mortality and to identify deviation from the expected progress by comparison with two industrialized nations, the USA and Japan. Between 1976 and 1983 the overall mortality showed an annual average of nearly 2% decrease, mostly contributed by the marked reduction in the number of young. Significant reductions were also observed for deaths from strokes, rheumatic heart disease, ill-defined conditions, cancer of the stomach, and infectious diseases such as tuberculosis. A disturbing increase in suicide as well as accidents primarily caused by motor vehicles was noted. In general, cancer increased, to an alarming degree for environmentally implicated cancers such as lung, pancreas, nasopharynx, brain and liver in men. When compared to that of the USA or Japan, the mortality experience of Taiwan showed the following increases: overall female mortality, accidental deaths, suicide among elderly women, deaths from strokes, ulcers, asthma, and liver, nasopharyngeal and cervical cancers. However, the overall cancer mortality rate was still much lower than that either in the USA or Japan. Despite marked reductions in infectious disease mortality, deaths from tuberculosis were nearly 40 times those of the USA. Although deaths from ill-defined conditions decreased by half during this study period, they were still high, particularly among elderly women (13% of all deaths and 22 times higher than the USA), which probably reflects inadequate medical services for women. The role of the Taiwanese government in the financing of health services was found to be far smaller than that of the USA or Japan. Expanding health care expenditure by the government is desirable if improvement in the maldistribution of medical services is to be achieved and the untoward health effects of rapid industrialization is to be reduced.

The human X-linked steroid sulfatase gene and a Y-encoded pseudogene: evidence for an inversion of the Y chromosome during primate evolution

The mammalian X and Y chromosomes are thought to have evolved from a common, nearly homologous chromosome pair. Although there is little sequence similarity between the mouse or the human X and Y, there are several regions in which moderate to extensive sequence homologies have been found, including, but not limited to, the so-called pseudoautosomal segment, in which X-Y pairing and recombination take place. The steroid sulfatase gene is in the pseudoautosomal region of the mouse, but not in man. We have cloned and characterized the human STS X-encoded locus and a pseudogene that is present on the long arm of the Y chromosome. Our data in humans and other primates suggest that there has been a pericentric inversion of the Y chromosome during primate evolution that has disrupted the former pseudoautosomal arrangement of these genes. These results provide additional insight into the evolution of the sex chromosomes and into the nature of this interesting portion of the human genome.

Participation in a periodic physical examination program and group health care utilization and costs

The authors identified 710 male employees of a multinational US corporation eligible to take periodic physical examinations for a consecutive 3-year period (1983 to 1985) and insured by one of the company's health insurers. Group health insurance claims rates and costs for the calendar year 1985 were studied among executives who did not take an examination during the study period, those who took it once or twice, and those who took it all 3 years. Health care utilization for those who did not participate in the program was significantly lower than both groups of participants. Average claim costs in 1985 among those who participated all 3 years ($1,039) was 1.77 times the cost of those who participated one or two times ($588) and 2.30 times the cost of those who did not participate ($452). We conclude that short-term health care utilization and costs are higher among participants than non-participants of a periodic physical examination program.

Obesity and morbidity prevalence in a working population

As part of ongoing medical surveillance, the morbidity prevalence for obese individuals (20% to 40% and greater than 40% overweight) was compared with non-obese corporate employees utilizing group health insurance claims data for 1985. The advantages of claims data as a potential source of morbidity data for disease surveillance and research are discussed herein. The expected finding of a positive association between hypertension (P less than .05) and obesity noted for both male and female employees reiterates the important role of work site weight control programs in reducing hypertension. The positive association between prevalence of mental health disorders and obesity demonstrates the need to address the adverse psychologic risks of obesity in addition to the adverse physical risks. This finding suggests that employee assistance programs emphasize counseling services for obese individuals.

Injury prevalence and associated costs among participants of an employee fitness program

The prevalence, cost, and type of injury among participants of an employee fitness program and nonexercising co-workers were studied over a 2-year period from 1984 to 1985. The purpose of the study was to determine whether participants of an employee fitness program (n = 2,871) experienced a greater risk of injury and resultant higher costs than nonparticipants (n = 3,233). Overall, there were no significant differences in the rate or cost of injuries among the various participation levels (from 0 to 3 or more times per week). However, the data indicated that individuals who occasionally participated in the fitness program experienced a greater, but nonsignificant, risk of injury (6.3 per 100 persons who exercised less than 1 session per week, and 7.7 per 100 persons who exercised 1-2 sessions per week) than nonparticipants (5.7 per 100 persons). Injury prevalence was lower among individuals who exercised 3 or more sessions per week (5.4 per 100 persons) as was the resultant per capita cost of injuries ($32 vs $42 for nonparticipants). We conclude the impact of exercise at an onsite health and fitness facility on overall injury rates and costs among employees is negligible.

Effect of curtailed insurance benefits on use of mental health care. The Tenneco health plan

This article presents the impact of a health insurance benefit redesign on utilization and costs for mental health care in a large corporation. The design change primarily limited coverage to 45 days of hospitalization and 20 outpatient visits. Group health insurance data before and after the benefit changes (effective January 1, 1984) were compared and analyzed. Per capita charges for mental health care between 1983 and 1985 decreased by 41%, from $89 to $53. Responses to the benefit modifications differed for inpatient and outpatient services. Inpatient costs and length of stay decreased dramatically, especially for dependents, while utilization rates remained about the same. Statistically significant increases occurred for outpatient care utilization and costs.

Health care utilization and costs for diseases of the circulatory system in a corporate setting

This article presents the health care utilization and costs for diseases of the circulatory system among 14,162 employees and their spouses based on medical insurance claims data analysis. Diseases of the circulatory system ranked first among insurance claims and costs accounting for 23% ($4.6 million) of the plan's total health care costs ($19.7 million) for the 1984 policy year. Overall, 57% of these expenditures were for hospital care, the proportion for hospital costs being as high as 64% for heart diseases and as low as 20% for hypertension. Male employees had higher utilization for both in-hospital and out-patient services than females. Utilization rates and costs dramatically increased for individuals 50 years or older. Costs for surgical and diagnostic procedures amounted to 8% of the total costs of circulatory system disorders. This article provides an example of the utility of claims analysis for morbidity surveillance. The analyses and parameters measured herein can be viewed as prerequisites to the development of health care management and health promotion strategies aimed at reducing health care cost for diseases of the circulatory system in a corporate setting.

Mental health care utilization and costs in a corporate setting

This article presents the mental health care utilization and costs among 14,162 employees and their families, covered under a major medical policy of a large multinational corporation for the 1984 policy year. Mental health care costs comprise a substantial portion of the total health care dollars expended (8.1%) for a relatively small fraction of the total number of claims (2.8%). The average hospital stay for mental disorders (20 days for employees; 15 days for spouses; 43 days for dependents) was significantly longer than for other illnesses (6.1 days for employees; 6.2 days for spouses; 4.4 days for dependents). Although the average daily hospital cost for mental disorders was less than that for non-mental conditions, total expenditures per admission were approximately three times higher due to the long lengths of stay. Case management, peer utilization review, and day treatment are recommended to reduce these costs.