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Biomedical subjects

P Schulte

Publications and source records attributed to P Schulte.

At least 19 recordsLinked to original sources
PubMed1991

Drake Chemical Workers' Health Registry Study: I. Notification and medical surveillance of a group of workers at high risk of developing bladder cancer.

A medical surveillance program and epidemiologic study of 408 former workers of the Drake Chemical Company (now a Superfund waste site) was established in 1986. The Drake Health Registry Study was initiated because these workers had probable past exposures to beta-naphthylamine (BNA), a potent bladder carcinogen. The registry is widely viewed as a model for notification of workers at high risk of disease due to past occupational exposures. By the 40th month, 90% of the 366 living workers had been notified of the existence of the registry; 262 had been enrolled in the annual or semi-annual screening for bladder cancer. Among these, 27 persons have had abnormal screening results indicating moderate to high risk of bladder cancer and have been made eligible for further diagnostic tests. While no invasive bladder tumors were found among 18 persons completing the extended diagnostic evaluation, two diagnoses of moderate to severe dysplasia have been made. The registry has also identified three living and three deceased cases of bladder cancer in the cohort; a mortality analysis showed a 20- to 30-fold excess of bladder cancer. An incidence projection, based on the six identified cases, reveals that between six and ten new bladder cancer cases are likely to occur among the Drake cohort over the next 20 year period.

2-Naphthylamine↗
PubMed1991

Validation of biological markers for quantitative risk assessment.

The evaluation of biological markers is recognized as necessary to the future of toxicology, epidemiology, and quantitative risk assessment. For biological markers to become widely accepted, their validity must be ascertained. This paper explores the range of considerations that compose the concept of validity as it applies to the evaluation of biological markers. Three broad categories of validity (measurement, internal study, and external) are discussed in the context of evaluating data for use in quantitative risk assessment. Particular attention is given to the importance of measurement validity in the consideration of whether to use biological markers in epidemiologic studies. The concepts developed in this presentation are applied to examples derived from the occupational environment. In the first example, measurement of bromine release as a marker of ethylene dibromide toxicity is shown to be of limited use in constructing an accurate quantitative assessment of the risk of developing cancer as a result of long-term, low-level exposure. This example is compared to data obtained from studies of ethylene oxide, in which hemoglobin alkylation is shown to be a valid marker of both exposure and effect.

Biomarkers↗
PubMed1991

[Compartment syndrome after femoral contusion. Case report and review of the literature].

Compartment syndromes of the lower arm and lower leg are quite well known by now and have been often described in the literature. Those of the upper arm and thigh are rarer and those after pure closed lesion of the soft parts of the thigh are the subject of only sporadic reports in the literature. A recently observed case of this kind prompted the present case report and review of the literature.

Adult↗
PubMed1990

Dioxygenolytic cleavage of aryl ether bonds: 1,2-dihydro-1,2-dihydroxy-4-carboxybenzophenone as evidence for initial 1,2-dioxygenation in 3- and 4-carboxy biphenyl ether degradation.

A bacterial strain, Pseudomonas sp. POB 310, was enriched with 4-carboxy biphenyl ether as sole source of carbon and energy. Resting cells of POB 310 co-oxidize a substrate analogue, 4-carboxybenzophenone, yielding 1,2-dihydro-1,2-dihydroxy-4-carboxy-benzophenone. The ether bond of 3- and 4-carboxy biphenyl ether is cleaved analogously by initial 1,2-dioxygenation, yielding a hemiacetal which is hydrolysed to protocatechuate and phenol. These intermediates are degraded via an ortho and meta pathway, respectively. Alternative 2,3- and 3,4-dioxygenation can be ruled out as triggering steps in carboxy biphenyl ether degradation.

Benzoates↗
PubMed1990

Screening workers exposed to 4,4'-methylenebis(2-chloroaniline) for bladder cancer by cystoscopy.

A bladder cancer incidence study was conducted among 540 workers exposed to the potential bladder carcinogen 4,4'-methylenebis(2-chloroaniline) from 1969 to 1979. Among the 385 workers who participated in a urine screening examination, none had suspicious or positive cytology. Twenty-one workers had at least one reading of atypia and 60 had either a positive dipstick for heme or greater than five red blood cells per low power field. The study protocol initially involved referral to private physicians for follow-up of any suspicious laboratory results. However, the diagnosis by cystoscopy of a bladder tumor in a nonsmoking man less than 30 years old with low-level hematuria prompted us to offer cystoscopy to all members of the cohort. A total of three tumors were identified in 200 persons who received cystoscopy. All were low-grade, papillary tumors and two occurred in men with completely normal urine screening results. These findings suggest that cystoscopy of asymptomatic persons should be considered in designing bladder cancer screening programs in high-risk cohorts.

Adult↗
PubMed1989

Degradation of 2-bromo-, 2-chloro- and 2-fluorobenzoate by Pseudomonas putida CLB 250.

Pseudomonas putida strain CLB 250 (DSM 5232) utilized 2-bromo-, 2-chloro- and 2-fluorobenzoate as sole source of carbon and energy. Degradation is suggested to be initiated by a dioxygenase liberating halide in the first catabolic step. After decarboxylation and rearomatization catechol is produced as a central metabolite which is degraded via the ortho-pathway. After inhibition of ring cleavage activities with 3-chlorocatechol, 2-chlorobenzoate was transformed to catechol in nearly stoichiometric amounts. Other ortho-substituted benzoates like anthranilate and 2-methoxybenzoate seem to be metabolized via the same route.

Benzoates↗
PubMed1989

Cohort and case-control analyses of workers exposed to vinyl chloride: an update.

The mortality in a cohort of workers at a vinyl chloride polymerization plant has been updated, extending the period of observation in the original study from 1974 to 1986. Workers at this plant may have been exposed to vinyl chloride monomer and/or polyvinyl chloride dust, or may have had no exposure to either substance. Seventy-six percent of the work force worked in jobs with potential exposure to vinyl chloride monomer. Among the total cohort, statistically significant excess risks were observed for liver, lung, and brain cancer. For the subcohort of workers exposed to vinyl chloride monomer, the standardized mortality ratio (SMR) for liver cancer was 333 (90% confidence interval (CI) 202 to 521). However, there were no significant excesses of either brain (SMR = 145, 90% CI 78 to 249) or lung cancer (SMR = 115, 90% CI 96 to 141). To investigate dose response, nested case-control studies for liver, brain, and lung cancer were conducted among the total cohort (including the nonexposed). For these studies there were two exposure variables, cumulative dose of vinyl chloride monomer and cumulative dose of polyvinyl chloride dust. Cumulative dose was defined as the product of level and duration of exposure. The only significant association between disease risk and cumulative dose was for liver cancer and cumulative dose of vinyl chloride monomer. Further division of the liver cancers into angiosarcoma (n = 12) and other liver cancers (n = 7), based on review of death certificates and medical records, showed that the dose response existed only for angiosarcomas.

Brain Neoplasms↗
PubMed1988

Bladder tumors in two young males occupationally exposed to MBOCA.

MBOCA (4,4' methylenebis (2-chloroaniline) is a structural analogue of benzidine and is carcinogenic in mice, rats, and dogs. MBOCA has not yet been demonstrated to be carcinogenic in humans and is not regulated as an occupational carcinogen in the United States. We report two noninvasive papillary tumors of the bladder identified in a screening study of 540 workers exposed to MBOCA during its production at a Michigan chemical plant from 1968 to 1979. Both tumors occurred in men under 30 years old who had never smoked. Although the prevalence of grade 1-2 tumors among asymptomatic males in this age group is unknown, the incidence of clinically apparent tumors on U.S. males aged 25-29 is only 1 per 100,000 per year. The detection of the two tumors in young, nonsmoking males is consistent with the hypothesis that MBOCA induces bladder neoplasms in humans.

Adult↗
PubMed1986

Interventions in high-risk occupational cohorts: a cross-sectional demonstration project.

In 1980, the Workers' Institute for Safety and Health began a demonstration project designed to develop a model program of community-based intervention in three cohorts with different workplace exposures and target cancer sites. Program components included identification, notification, medical surveillance, education, social support services (eg, psychosocial, legal, financial, etc), and evaluation. The three cohorts included the Augusta cohort, a group at risk for bladder cancer due to workplace exposure to beta-naphthylamine; the Port Allegany cohort, a group at high risk of cancer associated with a workplace exposure to asbestos; and the Pattern Makers cohort, a group shown to be at increased risk of colorectal cancer. Together, these three projects give a cross-sectional view of possible approaches to educational and medical intervention strategies in diverse situations.

Asbestosis↗
PubMed1982

The Kentucky elderly need assessment: concurrent validity of different measures of unmet need.

The purpose was to examine the concurrent criterion-based validity of different measures used in a statewide in-home need assessment survey of a representative sample of 570 older persons. Need was measured and defined in four different ways in six problem areas. The criterion measure was a life satisfaction scale. The set of four need measures yielded a significant multiple R, indicating that the set would generally be related to life satisfaction in older persons. Individually, three of the four need measures made significant contributions. The set of six problem areas also yielded a significant multiple R, with four (Mental Health, Health, Income, Nutrition) making significant individual contributions. Implications for need assessment measurement included: that problem-focused measures are strongly and generally related to need satisfaction, whereas service-focused measures have problems; that both evaluative and descriptive measures appear to be related to need satisfaction; and the clear value of a multineed conception for measurement and for application to program planning and resource allocation. Suggestions for improvement in measures were made and cross-validation called for.

Aged↗
PubMed1980

Measuring citizen evaluations of services amidst community change.

Citizen surveys are increasingly being used by communities to evaluate services; however, previous work suggests that such evaluations of specific services may be influenced by generalization from other attitudes. Surveys repeated annually for 4 years allowed an examination of such possible "contagion" effects since they were done before, during, and after a highly visible, extensive change--court-ordered busing--which engendered intense negative attitudes. Evaluations of busing-related services underwent a significant decline during the onset of busing; evaluations of nonbusing services declined but not significantly, indicating that a contagion effect was not a strong factor. There were also no significant contagion effects on nonbusing services in city and suburban subsamples, nor on neighborhood or community-wide delivery levels. Neighborhood-level services were evaluated significantly more positively than community-wide services each of the 4 years. Rank order evaluations remained stable during the change. It was concluded that citizens do discriminate among services on citizen surveys even in the face of strong attitudes toward community changes, that their evaluations are generally stable over time, and that these are sensitive to at least highly visible program changes.

Adolescent↗