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Biomedical subjects

J W Berg

Publications and source records attributed to J W Berg.

At least 37 records · Page 2Linked to original sources
PubMed1980

The effects of long-term ingestion of asbestos on the colon of F344 rats.

Weanling F344 rats, which were fed a diet containing 10% chrysotile (B), were studied over their life-time to determine the effects of ingested asbestos on the colon. Control groups consisted of rats fed a diet containing a 10% nonnutritive cellulose or a standard laboratory rat diet. The pathological findings in the colons of 501 rats (189 on asbestos diet, 197 on fiber control diet, and 115 on standard control diet), are reported here. Epithelial tumors of the colon (eight adenocarcinomas and one adenoma) were found in nine of the rats on study. Four of the tumors were in asbestos-fed rats, two tumors were found in the non-nutritive cellulose controls, and three tumors were found in the standard laboratory rat diet controls. The probability (based on actuarial analysis) of developing adenoma or adenocarcinomas during the 32 months of the study were 7.4% for the asbestos-fed group, 3.5% for the fiber control diet and 4.0% on the standard control diet. In addition, one malignant mesothelioma of the type induced by intraperitoneally administered asbestos was found in the asbestos-fed group. Non-neoplastic lesions of the colon were also evaluated. The cumulative risk for development of any colon-associated lesion (non-neoplastic plus neoplastic lesions) was greatest for asbestos-fed rats (17.9%), compared to 13.6% for those fed the fiber control diet and 8.2% for those fed the standard control diet. The colon tissue levels of adenosine, 3'-5'-cyclic monophosphate (cAMP) were significantly lower in the animals fed asbestos compared to the control diets. Chrysotile fibers were seen by electronmicroscopy (e.m.) in six of ten ashed colon specimens of rats fed the asbestos diet. Although the differences in numbers of tumors between the animals fed asbestos and the controls were not statistically significant at the 5% level, we felt that the combination of observations including 1) evidence of increased probability of asbestos-fed animals to develop colon lesions in general; 2) evidence of a special type of mesothelioma in rats fed asbestos; 3) evidence for a cell regulator defect (lowered cAMP levels) in colon tissues of animals fed asbestos; and 4) evidence for asbestos fiber penetration of the colonic mucosa (e.m. studies) suggest that ingested asbestos is not inert in the colon.

Adenocarcinoma↗
PubMed1980

Epidemiologic relationships of the bovine population and human leukemia in Iowa.

Data from the Third National Cancer Survey and data collected under the auspices of the National Cancer Institute's Surveillance, Epidemiologic and End Results (SEER) Program were used to perform a descriptive epidemiologic study of leukemia in Iowa. Data were also collected on livestock population patterns in the state, and a survey was performed to locate cases of lymphosarcoma within the cattle population. Ecologic relationships between human leukemia, livestock populations and bovine lymphosarcoma were investigated. Iowa has higher rates than the national average for human leukemias. The lymphoid leukemias make up the majority of the excess leukemias. Excessive acute lymphoid leukemia (ALL) is seen in the ages under 20 years and over 60 years. The excess ALL is in males living in rural counties. There is no sex difference for chronic lymphoid leukemia (CLL), but there is a slight urban-rural differential. There is a high positive correlation between ALL in males and cattle density. This relationship is greater for daily cattle than for beef cattle. There is an additional positive relationship between counties with excessive ALL and the presence of dairy herds affected with bovine lymphosarcoma.

Adolescent↗
PubMed1978

A retrospective epidemiologic study of pediatric fibrosarcomas.

One hundred eighty-two patients with histologically diagnosed fibrosarcoma below the age of 19 yr reported to the End Results Section of the National Cancer Institute before 1971 were analyzed. Race, sex, and age did not significantly affect prognosis. Site of the primary lesion and extent of disease at diagnosis did significantly affect prognosis. Overall 3-yr survival was 80%, and this remained constant over the next 5 yr. Survival of patients with upper extremity lesions exceeded 90%, whereas those with retroperitoneal primary sites had 17% survival. Patients with localized disease at diagnosis had 5-yr survival of 90%, but those with disseminated disease had a median survival of 6 mo, and 22% 1-yr and 5-yr survival.

Adolescent↗
PubMed1977

Economic status and survival of cancer patients.

The relation of economic status to survival was studied for 39 kinds of cancer representing all types for which 60 or more indigent patients were seen in University of Iowa Hospital for primary care during the years 1940-1969. For every type the indigent patients had poorer survival than non-indigent patients. Quality of care would be eliminated as a major variable since a second group of "ward" patients of higher economic status was available for comparison and the differences were substantially greater between the two groups of teaching patients than between the "clinic pay" and "private" patients. Age differences and differences in stage of disease accounted for less than half of the survival deficits in the indigents. The two important problems were high mortality from causes other than cancer and excess cancer mortality not accounted for by stage differences, particularly among patients who should have had 5-year survival rates between 40 and 70%. In these patients cancer recurred more often and earlier among the indigent. We postulate host differences associated with poverty that could also account for much of the observed Black-White differences as well as some international differences in cancer survival rates.

Adolescent↗
PubMed1977

Multiple primary cancers at Memorial Hospital 1949-1962.

The Memorial Hospital, New York, surveys of multiple primary cancer risks undertaken during 1965-1971 are summarized. After re-examination the methodological problems noted were: 1) that prospective studies tell us more than prevalence or retrospective studies; 2) that risks must be related to the observation period, patient's ages, etc.; 3) that hospital series probably are selected but that this may be overcome by internal comparisons; 4) that the search for explanatory variables is difficult, to the extent data on these variables were not explicitly collected; and 5) that computing multiple risk ratios for each of many cancer types guarantees a number of accidentally statistically significant results. It was also concluded that most cancer patients have excess risk for specific later cancers, depending on their original cancer type and that knowledge of these risks is of true clinical importance.

Epidemiologic Methods↗
PubMed1977

Selection of treatment regimens for women with potentially curable breast carcinoma.

Five-year survival rates for all Iowa breast cancer patients diagnosed in 1969 are substantially better than most published figures. Partly, this is because more Iowa patients came to treatment early before they developed diagnosable metastases. There also, however, were particularly good results for radical mastectomy compared to modified operations and when axillary metastases were present the results were much the best when supervoltage radiation followed the radical operation.

Breast Neoplasms↗
PubMed1975

Can nutrition explain the pattern of international epidemiology of hormone-dependent cancers?

International data on the distribution of hormone-dependent cancers suggest that they are cancers of affluence. Their occurrence parallels that of bowel cancer fairly closely in population and less closely with regard to individual patient risk. The most plausible hypothesis, although based on extremely incomplete knowledge, is that some components of the Western high-protein, high-fat diet acting in early life make individuals prone to develop these cancers.

Breast Neoplasms↗