Levels of amino acids and related compounds in bronchoalveolar lavage fluids of asthmatic patients

The constituents of bronchoalveolar lavage (BAL) fluid have been shown to reflect the presence and possible etiology of several pulmonary diseases. Presently, although research studies have reported the concentrations of cytokines and compounds such as major basic protein in BAL fluids, only the cellular elements, total protein, albumin, and immunoglobulins have been well defined. We hypothesize that amino acids and related amino compounds, well known participants in physiologic and biochemical processes, are present in BAL fluid and may have involvement in asthma. Our objective was to extend knowledge of the total chemical profile and clinical value of BAL fluids in humans by measuring these amino compounds in normal control subjects and asthmatic patients. Analysis by high-pressure liquid chromatography revealed the presence of 25 compounds. A few compounds in control subjects and patients were found to have values > 1.0 nmol/ml, while the majority were present in comparatively low concentrations < 1.0 nmol/ml. Asparagine, phosphoethanolamine, and taurine were significantly increased in the asthmatic patients. We conclude that the present profile of amino acids and related amino compounds in BAL fluid serves as a potential diagnostic tool in the study of various pulmonary disorders. The significance of increased asparagine, phosphoethanolamine, and taurine in the asthmatic patients is discussed and deserves further study.

A profile of amino acid and catecholamine levels during endotoxin-induced acute lung injury in sheep: searching for potential markers of the acute respiratory distress syndrome

The identification of plasma markers of the course of the acute respiratory distress syndrome (ARDS) is needed to improve its treatment and to further advance the development of new therapeutic agents. The status of markers of lung injury in ARDS is reviewed and some new potential markers are proposed. This study focused on plasma amino acids, related amino compounds, and catecholamine levels during the acute phase of endotoxin-induced lung injury in 8 sheep characterized by the onset of pulmonary edema caused by increased microvascular permeability. A number of significant changes from baseline values were found. During the sixth hour of a 12-hour period of endotoxin infusion, norepinephrine, epinephrine, and alanine levels increased whereas the isoleucine level decreased. During the sixth hour of the immediate postendotoxin period, the taurine level increased while the levels of arginine, citrulline, glycine, isoleucine, methionine, ornithine, serine, threonine, and tryptophan decreased. These findings are compared with prior studies in human subjects detailing the amino acid profile characteristic of advanced sepsis. We conclude that the present profile of catecholamine and amino acid changes during endotoxemia in sheep deserves further study in human subjects to determine its significance as a marker of the early stage of ARDS.

The effects of arginine administration on the levels of arginine, other amino acids and related amino compounds in the plasma, heart, aorta, vena cava, bronchi and pancreas of the rat

Arginine (0.8g/kg, ip) or a vehicle was administered to rats and the levels of arginine and a large number of related amino compounds++ were measured in plasma, heart, aorta, vena cava, pancreas and bronchi at specified time intervals. Arginine levels (nmol/ml) increased in the plasma from 237 to 3172 at 15 min, 1236 at 30 min and 509 at 120 min. Peak concentrations (nmol/g) of arginine are reached in the tissues at 15 or 30 minutes with control and postinjection values of 500 and 1769 in the heart, 314 and 1563 in the aorta, 575 and 2976 in the vena cava, 760 and 1943 in the bronchi, and 234 and 3638 in the pancreas. Arginine injection also affects a number of amino acids and related compounds in the plasma and tissues most notably ornithine, isoleucine, phosphoserine, leucine and ethanolamine. However, plasma level changes do not predict tissue level changes which are highly specific for an individual compound and tissue. There was no general indication that arginine injection stimulates nitric oxide (NO) formation in any tissue. Thus, arginine is rapidly absorbed from the abdominal cavity into the blood stream, is quickly taken up by the tissues studied and disappears after about 2 to 3 hours. The effects seen after arginine administration could be caused by arginine per se and/or changes in one or more of the related amino compounds but not by NO.

Epidemiologists in industry. Past achievements, unexplored opportunities, and future needs

Epidemiologists in industry have achieved much in the past several years. In addition to conducting important research into known or suspected hazards in the workplace, they have taken the lead in developing a code of ethics for epidemiologists in industry, established guidelines for good epidemiology practices, and have been actively involved in the development of government regulations and the setting of standards. Yet the scope of their activities can be expanded even further. I have discussed some of these, such as environmental health studies, long-term evaluations of health promotion programs, and research into major chronic diseases. But to move into new areas of research and to continue their work in traditional areas, they need to overcome some important obstacles. Among these that I have discussed are: problems involved in getting comprehensive morbidity information into their data bases, restrictions imposed on access to data by privacy protection laws and regulations, and difficulties in publishing and disseminating the results of negative studies. To overcome these obstacles and to enable industry epidemiologists to expand their activities into new areas, they will need additional support from government regulators to ease restrictions on data acquisition, and from company management to provide their epidemiologists with the resources they need. I hope that such support will be forthcoming so that epidemiologic research in industry can achieve its full potential.

The nutritional status in advanced emphysema associated with chronic bronchitis. A study of amino acid and catecholamine levels

Advanced emphysema with bronchitis is associated with significant weight loss and malnutrition, the true cause of which has not been clearly identified. The purpose of this exploratory study was to compare plasma amino acids and related compounds and catecholamines in a group of patients with advanced end-stage emphysema with a control group of similar age and sex in an effort to further understand this malnourished state. Fasting blood samples were obtained by venipuncture after a rest period. Plasma amino acid levels were determined by ion exchange high pressure liquid chromatography with fluorometric detection. Plasma catecholamines were determined by radioenzymatic analysis. Anthropometric measurements, the usually accepted biochemical markers of nutrition, dietary analysis, pulmonary function tests, and a historical analysis of the state of health including drug use and smoking history in each subject were analyzed. Ages and heights were comparable, whereas weights were significantly decreased in the patients with emphysema. Total serum protein and serum albumin values were significantly lower in the patient group. Significant respiratory muscle weakness was indicated by reduced negative inspiratory force in these end-stage patients, contrasting with well-preserved muscle strength usually found in obstructive lung disease. The dietary caloric intake of the patients was comparable to that of the control subjects. We conclude that the fine balance of the amino acid pool in patients with bronchitis and emphysema is well preserved, except for significant elevations of aspartic acid, glutamine, and cystine, and a decreased level of leucine. In addition, norepinephrine levels were significantly increased. Weight loss in patients with emphysema and bronchitis is likely due to increased energy demands related to hypermetabolism.

Mortality surveillance in a large chemical company: the Union Carbide Corporation experience, 1974-1983

The mortality experience of 88,000 Union Carbide Corporation employees from 1974 to 1983 is presented using a population-based surveillance system. The study included many long-term employees, with most deaths contributed by those retired or terminated. The total population exhibited 30% lower mortality overall and 10% lower cancer mortality, as compared with the general U.S. population. Excesses of benign neoplasms and malignant melanoma of the skin were observed in both hourly and salaried males. Mortality rates for lymphosarcoma and reticulosarcoma were significantly elevated due to higher rates among hourly male employees and a cluster in one location. This same location also exhibited an excess of liver cancer associated with vinyl chloride operations. There were no other significant excesses in the hourly male workers and fewer deaths than expected due to brain cancer, respiratory cancer, and nonmalignant respiratory diseases. Salaried, and particularly hourly, women experienced favorable mortality, although for the women, time since hire was relatively short. Location-specific findings were similar to what had been observed in the company's previously conducted cohort studies. Future value lies in the development of a database that will have greater power to address possible effects of past exposures and outcomes related to more recent lower level exposures.

A case-control study of cancer among du pont employees with potential for exposure to dimethylformamide

This case-control study was undertaken to determine whether the risk of developing cancers of the buccal cavity and pharynx (N = 39), liver (N = 6), prostate (N = 43), testis (N = 11), or malignant melanoma of the skin (N = 39) is related to exposure to dimethylformamide (DMF). Case and control subjects were obtained from four Du Pont plants. DMF is produced at one plant and used at the other three. Cancer cases identified from the company Cancer Registry comprise those reported among active male employees at the study plants during 1956 to 1985. For each case, two control subjects were selected, matched on sex, payroll class (wage or salary), birth year, and plant. To determine whether an employee could have been exposed to DMF during his career at the plant, all jobs with potential for exposure to DMF were identified. Each job was assigned an exposure ranking based on DMF industrial hygiene air monitoring, DMF metabolite (measured as N-methylformamide in urine) monitoring, and knowledge of the evolution of manufacturing processes and workplace exposure controls. Each employee's DMF exposure pattern was then characterized as (a) ever v never having been exposed to DMF and (b) highest DMF exposure experienced. Summary analyses for all plants combined showed no statistically significant association between ever having been exposed to DMF and subsequent development of cancers of the buccal cavity and pharynx, liver, malignant melanoma, prostate, and testis. Examined by plant site, prostate cancer at one plant was significantly elevated, based on three case subjects exposed out of four.(ABSTRACT TRUNCATED AT 250 WORDS)

Cancer incidence of workers exposed to dimethylformamide and/or acrylonitrile

This study was to determine whether exposure to dimethylformamide (DMF) and acrylonitrile (ACN) separately or in combination, was associated with increased cancer incidence. Workers exposed to DMF and/or ACN were observed from 1956 through 1984 for cancer incidence. The workers exposed to DMF but not ACN showed significant excesses in incidence for buccal cavity and pharynx cancer and malignant melanoma. A significant excess of prostate cancer incidence was observed among workers exposed to DMF and ACN. No dose-response relationships were observed between DMF or ACN exposure and cancer incidence. The significant excesses in cancer incidence among employees exposed to DMF and/or ACN could be due to statistical chance or other factors, such as tobacco and alcohol consumption. Further studies are warranted.

Mortality study of workers exposed to dimethylformamide and/or acrylonitrile

Workers exposed to dimethylformamide (DMF) and/or acrylonitrile (ACN) were observed from 1950 through 1982 for mortality. The wage-roll workers exposed to DMF showed significant excess in total deaths attributable mainly to ischemic heart disease and external causes when compared with rates from E. I. Du Pont de Nemours & Co. However, there were no significant excesses in mortality when expected numbers were based on US or local statistics. No dose-response relationships were observed between DMF or ACN exposure and mortality. The significant excesses in mortality among employees exposed to DMF and/or ACN could be due to statistical chance or life-style factors

Cancer incidence and mortality in the Du Pont Company: an update

In a previous publication, Pell et al described the cancer epidemiologic surveillance program that was begun in the Du Pont Company in 1956 and presented standardized cancer incidence and mortality data through 1974 for Du Pont employees compared with such data for the US general population. This report provides the analysis of an additional 10 years of cancer incidence and mortality data, and examines time trends for specific cancer sites. Conoco, Inc, acquired in 1981, is not included in the analysis.

Cancer incidence and mortality among workers exposed to acrylonitrile

A cohort of 1,083 male employees who had potential for exposure to acrylonitrile between 1944 and 1970 at a Du Pont textile fibers plant were followed through 1981 for mortality and through 1983 for cancer incidence. In total, the 21 cancer deaths were fewer than expected based on either Du Pont or U.S. rates. No significant excesses were seen by primary site. In all, 37 cancer cases occurred as compared with 36.5 expected based on company rates. Five lung cancer cases were observed and 6.9 expected. There were 5 prostate cancer cases as compared with 1.9 expected. Of these, 4 occurred among wage employees during the 1975-1983 period, compared to 0.9 expected. This excess was statistically significant.

Epidemiologic study of workers exposed to acrylonitrile: an update

A previous report presented the cancer morbidity and mortality experience through 1976 of a cohort of 1,345 male employees with potential for exposure to acrylonitrile at a fibers-producing plant. This study has now been updated through 1983 for cancer incidence and through 1981 for mortality. Overall, 43 cancer cases have occurred, with 37.1 expected based on company rates. A previously reported excess number of cases of lung cancer remains, but is not as marked (10 observed, 7.2 expected). Prostate cancer cases were significantly in excess, with six cases observed and 1.8 expected. Mortality analyses revealed 36 cancer deaths, with 31.6 expected. Of these, 14 were from lung cancer, with 11.6 expected based on company rates. Only one death from prostate cancer occurred, with 1.0 expected. To our knowledge, prostate cancer excesses have not been reported in any other acrylonitrile studies, and hence their significance is currently difficult to assess.

Trends in the incidence of myocardial infarction and in associated mortality and morbidity in a large employed population, 1957-1983

We analyzed long-term trends in the incidence of a first acute myocardial infarction and in case-fatality rates among employees of the Du Pont Company from 1957 through 1983. A steady decline in incidence was observed among male employees. The annual age-adjusted rate in the 1957-1959 period was 3.19 per 1000, as compared with 2.29 per 1000 in the 1981-1983 period--a decline of 28.2 per cent. The rate of decline was higher among salaried (white-collar) employees than among production workers receiving hourly wages. No trend was seen among female employees, but the number of cases may have been to small to detect a decline. Beginning in 1969, the 24-hour case-fatality rate showed a moderate decline, but after 1975, there was a sharp drop in the 30-day case-fatality rate among persons who survived 24 hours after the attack. These declines did not begin until several years after the decline in incidence had begun. This study and others suggest that improved medical care probably made some contribution to the decline in mortality associated with coronary heart disease, but the major source of the decline has been a reduction in the incidence of the disease.

Brain cancer in the Du Pont Company

A study of brain cancer was conducted in the Du Pont Company to compare the Company's morbidity and mortality experience with that in the U. S. population. Incidence in the Company from 1956 through 1979 was compared to incidence reported in the Third National Cancer Survey, 1969-1971. Mortality from 1957 through 1979 was compared to U. S. mortality in 1968. The morbidity data were confined to active employees, whereas the mortality data included both active and retired employees. Neither data included former employees who left employment without a pension. During these study periods, there were 150 newly diagnosed brain cancer cases and 144 deaths from brain cancer. The data indicated that both morbidity and mortality in the company were essentially the same as in the general population. These results, however, do not preclude the possibility that there could be a group of workers in the company with an excess risk of brain cancer as a result of exposure to a carcinogen, although we are not aware of such a group. The identification of such a group, if it does exist, would have to be made by a case-control or prospective cohort study. Comparisons between male wage roll and salaried employees showed no difference in morbidity and no significant difference in mortality.

A retrospective cohort study of mortality and cancer incidence among chemist

This retrospective cohort study examines mortality and cancer incidence among 3,686 men and 75 women who were employed as chemists in 1959. During the period 1964 to 1977, the male chemists experienced lower overall mortality than other salaried employees of the chemical company (198 deaths observed, 241.0 expected, SMR = 82). Large deficits are seen in lung cancer and arteriosclerotic heart disease death. The chemist appear to be at slightly higher risk for death from malignancies of the colon (12 observed, 6.7 expected, SMR = 178) and from cerebrovascular disease (15 observed, 10.8 expected, SMR = 138). The low overall mortality resulted in a larger than expected proportion of deaths due to cancer. Fewer than expected cases were diagnosed of cancer of all sited combined (61 observed, 86.5 expected, SIR = 71) and of the lung (8 observed, 20.0 expected, SIR = 40). The incidence rates of melanoma and of cancer of the prostate are slightly higher than expected, relative to the Third National Cancer Survey and the experience of nonchemists, respectively. Among female chemists, deaths due to all causes and suicide occurred more frequently than expected. Possible explanations for the lack of anticipated excess risks and for the observed deficits are presented.

A retrospective cohort study of disability among chemists

This retrospective cohort study examines disability among 3,686 men and 75 women who were employed as chemists in 1959 and who were followed through 1977. Overall, the chemists experienced fewer absences of eight or more consecutive days than expected on the basis of the experience of other salaried employees of the chemical company. Among the men, fewer claims than expected were observed for absences due to benign and unspecified neoplasia, heart disease, and peptic ulcer, and to diseases of the urinary system, bones and joints, and skin. Also, the chemist had lower than expected incidence rates of first myocardial infarction (90 observed, 149.8 expected). The deficits may be attributable to exposure misclassification or to confounding by smoking or socioeconomic status. A slight excess was seen of absences due to mental disorders.

Epidemiological requirements for medical-environmental data management

In establishing a system to provide data for epidemiological research in occupational health, it should be recognized that such studies require more information than what usually becomes available routinely in occupational health programs. Additional types of data that may have to be put into the system include supplementary diagnostic information, level and duration of exposure to potentially hazardous substances, demographic information related to socioeconomic status and fertility, population census statistics for the entire company and various company installations, and follow-up-data on retired employees. The quality of the data is especially important for epidemiologic research. Therefore, data validation procedures need to be established whereby the information that goes into the system is reviewed for precision, completeness, and reliability.

Mortality of workers exposed to chloroprene

A study was undertaken to determine whether exposure to chloroprene increases the risk of lung cancer. Data were obtained from historical prospective mortality studies of two cohorts, one consisting of 270 men first exposed between 1931 and 1948, and the other of 1,576 men first exposed between 1942 and 1957. The number of lung cancer deaths in each cohort (three in the first and 16 in the second) were about the same as expected. Among maintenance mechanics in the second cohort, there were eight lung cancer cases (four living and four dead). A crude morbidity analysis suggested that this group may have had an excess incidence of lung cancer. However, the absence of excess lung cancer mortality in other high exposure occupational groups indicates that chloroprene exposure does not increase the risk of lung cancer.

Utilization of medical information systems in American occupational medicine. A committee report

In an attempt to define the nature of medical programs and the extent of utilization of information systems in occupational medicine, a questionnaire was directed to 230 corporate medical directors of the largest employers in the USA. Responses were received from 163 (nearly 70%) of those contacted. While industrial injury data and sickness absence statistics are the principal areas of present computer analysis, respondents indicated that future plans called for a shift in emphasis to the analysis and correlation of human medical data with work exposure data. Nearly three-quarters of the respondents are planning more extensive medical information systems. It is concluded that there is an apparent need for both trained personnel to develop appropriate systems and enhanced communication between the users and suppliers of the required computer technology.

Development of a medical center rape crisis intervention program

The Rape Crisis Intervention Program at Beth Israel Hospital utilizes volunteer multidisciplinary counseling teams drawn from psychiatry, social work, psychology, and nursing staffs. The premise of the program is that early crisis intervention can prevent later development of psychological disturbances in later development of psychological disturbances in victims. Counselors accompany victims throughout emergency room procedures: follow-up begins 48 hours after the initial contact and continues at regular intervals for at least a year. The authors discuss the problems of implementation, which include staff resistance, finding questions, and varying levels of counseling sophistication, and describe how these difficulties have been handled in their program. They note that this program is becoming a resource center for the community.