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Biomedical subjects

R D Bass

Publications and source records attributed to R D Bass.

At least 19 recordsLinked to original sources
PubMed2001

Pathology of autoimmune myelofibrosis. A report of three cases and a review of the literature.

We identified 3 patients with autoimmune myelofibrosis (AM) lacking American Rheumatism Association criteria for systemic lupus erythematosus (SLE). They had 1 or 2 cytopenias and lacked serologic evidence for SLE. Autoimmune features included psoriatic arthritis and positive direct Coombs test (DCT) result, DCT-positive autoimmune hemolytic anemia, and synovitis with polyclonal hypergammaglobulinemia. Bone marrow biopsy specimens from each patient were evaluated by routine morphologic and immunohistochemical examination. They demonstrated marked hypercellularity (2 cases) or hypocellularity (1 case), moderate erythroid hyperplasia (all cases) with left-shifted maturation (2 cases), intrasinusoidal hematopoiesis (all cases), slightly to moderately increased megakaryocytes (2 cases), and grade 3 to 4 reticulin fibrosis (all cases). All lacked basophilia, eosinophilia, bizarre megakaryocytes, clusters of megakaryocytes, and osteosclerosis. Mild to moderate bone marrow lymphocytosis was noted in all cases. In 2 cases, increased small T cells and B cells formed nonparatrabecular, loose aggregates. AM is a clinicopathologic entity that may lack features of SLE. Loose aggregates of bone marrow T and B lymphocytes and the absence of morphologic and clinical features of myeloproliferative disease or low-grade lymphoproliferative disease are clues that distinguish AM from better known causes of bone marrow fibrosis.

Adult↗
PubMed1993

Benzene toxicity and risk assessment, 1972-1992: implications for future regulation.

Acute and chronic exposure to benzene vapors poses a number of health hazards to humans. To evaluate the probability that a specific degree of exposure will produce an adverse effect, risk assessment methods must be used. This paper reviews much of the published information and evaluates the various risk assessments for benzene that have been conducted over the past 20 years. There is sufficient evidence that chronic exposure to relatively high concentrations of benzene can produce an increased incidence of acute myelogenous leukemia (AML). Some studies have indicated that benzene may cause other leukemias, but due to the inconsistency of results, the evidence is not conclusive. To predict the leukemogenic risk for humans exposed to much lower doses of benzene than those observed in most epidemiology studies, a model must be used. Although several models could yield plausible results, to date most risk assessments have used the linear-quadratic or conditional logistic models. These appear to be the most appropriate ones for providing the cancer risk for airborne concentrations of 1 ppb to 10 ppm, the range most often observed in the community and workplace. Of the seven major epidemiology studies that have been conducted, there is a consensus that the Pliofilm cohort (rubber workers) is the best one for estimating the cancer potency because it is the only one with good exposure and incidence of disease data. The current EPA, OSHA, and ACGIH cancer potency estimates for benzene are based largely on this cohort. A retrospective exposure assessment and an analysis of the incidence of disease in these workers were completed in 1991. All of these issues are discussed and the implications evaluated in this paper. The range of benzene exposures to which Americans are commonly exposed and the current regulatory criteria are also presented.

Animals↗
PubMed1992

Reevaluation of benzene exposure for the Pliofilm (rubberworker) cohort (1936-1976).

The Pliofilm cohort is the most intensely studied group of workers chronically exposed to benzene. Information on this cohort has been the basis for regulations and/or guidelines for occupational and environmental exposure to benzene. Rinsky et al. (1986, 1987) and Crump and Allen (1984) developed different approaches for reconstructing the exposure history of each member of the group. The predicted levels of exposure, combined with the data on the incidence of disease, have been used to estimate benzene's carcinogenic potency. In this paper, recent information from worker interviews and historical records from the National Archives and elsewhere were used to evaluate the accuracy of prior exposure estimates and to develop better ones for the cohort. The following factors were accounted for: (1) uptake of benzene due to short-term, high-level exposure to vapors, (2) uptake due to background concentrations in the manufacturing building, (3) uptake due to contact with the skin, (4) morbidity and mortality data on workers in the Pliofilm process, (5) the installation of industrial hygiene engineering controls, (6) extraordinarily long work weeks during the 1940s, (7) data indicating that airborne concentrations of benzene were underestimated due to inaccurate monitoring devices and the lack of adequate field calibration mated due to inaccurate monitoring devices and the lack of adequate field calibration of these devices, and (8) likely effectiveness of respirators and gloves. Our estimates suggest that Crump and Allen (1984) overestimated the exposure of workers in some job classifications and underestimated others, and that Rinsky et al. (1981, 1986) almost certainly underestimated the exposure of nearly all workers. Airborne concentrations of benzene at the St. Marys facility during the years of its operation were found (on average) to be about half those of the two Akron facilities. Our analysis indicates that short-term, high-level exposure to benzene vapors and dermal exposure significantly increased (by about 25-50%) the total absorbed dose of benzene for some workers. One of the key findings was that, unlike prior analyses, the three facilities probably had significantly different airborne concentrations of benzene, especially during the 1940s and 1950s.

Air Pollutants, Occupational↗
PubMed1987

The impact of federally funded CMHCs on local mental health service systems. Community Mental Health Centers.

To measure how much federally funded community mental health centers increased the quantity and range of mental health services, 63 catchment areas in which CMHCs began to receive federal funding in 1974-75 were matched individually with catchment areas that never received federal CMHC funding. The two groups of catchment areas were compared to determine average increases from 1973 to 1980 in amounts of services, mental health staff, expenditures, and accessibility and availability of services. Results showed that establishment of local CMHCs had a clear impact on the quantity and the availability and accessibility of services in the catchment area. The effect sizes resulting merely from the passage of time and from CMHC funding were compared.

Catchment Area, Health↗
PubMed1985

The contrasting careers of two structural types of CMHCs.

Changes in funding, clientele, and services from 1971 to 1980 were examined cross sectionally and with cohorts for two types of CMHCs that differ in their structure for providing inpatient service. Inpatient provider CMHCs grew in revenues and shifted from reliance on federal funds to revenues from services and states. Inpatient-affiliated CMHCs fell in revenues (in constant dollars) and changed little in their proportional reliance on federal dollars. Inpatient provider CMHCs averaged more additions and episodes of care than inpatient-affiliated CMHCs. Inpatient-affiliated CMHCs grew more from 1971 to 1976, but from 1976 to 1980 inpatient provider CMHCs grew, while inpatient-affiliated CMHCs dropped or grew less. The relatively poor final showing of inpatient-affiliated CMHCs parallels findings with total revenues.

Adult↗
PubMed1985

Federally funded CMHCs: the effects of period of initial funding and hospital affiliation.

Previous research on federally funded community mental health centers has largely failed to recognize fundamental differences among different types of centers. Here we show that such basic factors as the arrangement for providing inpatient services and the period of initial federal funding have large effects on the development and organization of a center. Although the centers joining the federal program from 1965-1970 are the largest, those facilities funded between 1971-1975 are generally smaller than those funded later. The arrangement for providing inpatient services has an important effect on staffing. This work suggests the national norms may not be the most useful data for evaluating past performance or planning the future of a specific center.

Budgets↗
PubMed1984

Changing staffing patterns in community mental health centers.

During the last 15 years, there have been apparently contradictory criticisms of staffing patterns, and hence of care provided, in community mental health centers (CMHCs). To test their hypothesis that heterogeneity among CMHCs is responsible for the variety of criticisms, the authors examined staffing patterns in CMHCs between 1973 and 1981, dividing the centers into groups by organizational type. They found major differences in staffing between different types of centers, and between groups of centers added to the CMHC program during different time periods. The authors discuss the criticisms leveled at CMHCs in view of their findings, and suggest the research that is needed to clarify the differences between various types of CMHCs.

Community Mental Health Centers↗
PubMed1982

Fifty years of psychiatric services: 1940-1990.

Using data from the National Institute of Mental Health and the Census Bureau, the authors examine trends in the delivery of mental health services over the past 40 years as they relate to number and types of facilities, utilization of services, diagnosis, and maintenance expenditures. The data show that during this period access to psychiatric services has been broadened, and there has been increasing use of outpatient and community-based services. More recently there has been increasing reliance on the private sector to provide services, with the help of third-party reimbursement. In addition, the types of facilities have become more varied, providing a broader range of options for mental health care. The authors consider the future of mental health services in light of these trends.

Community Mental Health Services↗
PubMed1980

Community mental health centers and the treatment of severe mental disorder.

Between 1970 and 1975 the number and rate of admissions to community mental health centers of people given a diagnosis of schizophrenia increased dramatically. However, the proportion of patients with schizophrenia admitted to community mental health centers declined because the increase in the rate of admissions of patients with schizophrenia was diluted by the large increase in the rate of admissions of patients with other diagnoses. The authors review the data on trends in admissions of patients with a diagnosis of schizophrenia in the context of an expanding system of mental health services characterized by changes in the locus of care.

Acute Disease↗
PubMed1979

Community mental health centers and the "seed money" concept: effects of terminating federal funds.

What happens to community mental health centers when federal funding ends? Analysis of the funding patterns of a cohort of "graduate" community mental health centers indicates that these centers remained fiscally viable subsequent to termination of basic federal grants. However, further analysis revealed two distinct funding patterns within the cohort. One group relied primarily on increased third-party reimbursements to offset the end of basic federal grants. The other sought more state funds and additional federal grants available through the Community Mental Health Center Amendments of 1975. As more centers "graduate," federal "floor funding" may be necessary to insure the survival of some of them.

Community Mental Health Centers↗
PubMedDate not supplied

The National Reporting Program for Mental Health Statistics: history and findings.

The National Reporting Program for Mental Health Statistics had its origins in the decennial U.S. census, with enumeration of the "insane and idiotic" in 1840. A series of special censuses of the insane and feebleminded in public and private hospitals and other institutions began in 1904, and annual censuses of patients in mental institutions were conducted from 1926 to 1946. The National Institute of Mental Health of the Public Health Service took over responsibility for the annual census of patients in mental institutions in 1947. Coverage and content remained the same until the mid-1960s, when only State and county mental hospitals were included in the census. Because the annual census could not provide the data needed, separate programs were begun for inpatient and outpatient service. These were integrated into the National Reporting Program in 1966. Trend data for the last 40 years describe how the specialty mental health sector has developed. Non-Federal general hospitals with separate psychiatric services increased dramatically, from 81 in 1940 to 1,531 in 1982, as did community mental health centers, from 125 in 1965 to 691 in 1980. There was generally less emphasis on inpatient care and more on outpatient care. Full-time equivalent staff in specialty mental health facilities increased from about 325,000 in 1970 to about 432,000 in 1982. Expenditures by facilities also increased dramatically.

Community Mental Health Centers↗