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Biomedical subjects

I D Bross

Publications and source records attributed to I D Bross.

At least 19 recordsLinked to original sources

Assessment of myelotoxic effects of chemotherapy from early leukopenic response: application of a mathematical model for granulopoiesis.

A recently developed model of the human granulpoietic system had been used to analyze the toxic effects of 5-fluorouracil administered to cancer patients. From this analysis there appeared to be a relationship between the level of the early leukopenic depression and the rate at which the drug kills cells in the marrow. In particular, it may be possible to estimate this kill rate from the extent of the maximal depression in the white blood count during the second or third week after treatment begins. This estimate may be useful when planning modifications in treatment in order to prevent the onset of hematologic crises.

Antineoplastic Agents

A dosage response curve for the one rad range: adult risks from diagnostic radiation.

Most exposure to low-level ionizing radiation, both diagnostic x-rays and nuclear radiation, occur in the range between 100 milirads and 10 rads--the "one rad range". In the past, the estimates of hazards in this range have been obtained by linear extrapolation from data on persons who were exposed to much higher dosages, generally in the centirad range used in radiotherapy of non-malignant disease. This article presents the first dosage response curve for the one rad range ever to be developed directly from data on men exposed to ordinary diagnostic radiation. The findings are based on approximately 220 men with non-lymphatic leukemia and more than 270 random-sample controls from the Tri-State Survey. The new findings suggest that the estimates previously obtained by extrapolation from high dosage levels to low dose levels underestimate the actual hazards by an order of magnitude. The new dosage response curves indicate that linear extrapolation fails because it disregards the subgroups in the general population that are particularly vulnerable to x-ray. There are immediate implications concerning the use of medical x-rays in screening or for routine purposes. The past risk-benefit calculations are based on extrapolative estimates and require drastic revision. Uses of x-ray which were previously marginal are now clearly counterindicated.

Adolescent

An autopsy study of the metastatic patterns of human leukemias.

This paper analyses the distribution of metastases at every site of the human body in acute lymphoblastic, chronic lymphocytic, acute myeblastic and chronic myelocytic leukemias in patients that come to autopsy. It appeared that the 4 types of leukemia had a similar seeding frequency of the skin, breast, trachea, diaphragm and all other muscles. The highest incidence of metastases was found in the lymphatic system (i.e. all lymph-nodes and spleen). Acute lymphoblastic leukemia showed an excess of metastases in the major blood vessels, pleura, large intestines, extrahepatic biliary tract, ureters, prostate, cervix uteri, central nervous system, thymus, ovaries and pituitary. The excess of metastases at specific sites did not cluster either in topographical areas or in anatomical systems, with the exception of metastases in the central nervous and endocrine systems (acute lymphoblastic leukemia). Chronic lymphocytic leukemia showed an excess of metastases in all lymph nodes, kidney, adrenals and heart. A lymphatic route of dissemination, as opposed to a blood-borne spread of malignant cells, was hypothesised to account for the excess of metastases in the above mentioned organs in patients affected with chronic lymphocytic leukemia. Soil specificity with the degree of anaplasia of leukemic cells may account for the higher than expected occurrence of metastases in a given organ, for a specific leukemia. This remark holds true particularly for acute lymphoblastic leukemia.

Autopsy

Preliminary report on radiation and heart disease.

Using data from the Tri-State and a mathematical model, the hypothesis that low levels of diagnostic radiation can produce both leukemia and heart disease has been tested. The range of radiation considered is within a factor of 10 of 5 rads (0.5-50 rads). Even at the lowest levels, an estimated 5% of the persons exposed suffer damage to the DNA which is subsequently expressed as heart disease or leukemia. The risk of heart disease in an affected group is roughly tripled and there is a 10-fold increase in the risk of leukemia according to preliminary estimates.

Aged

Genetic damage from diagnostic radiation.

Using the data from the Tri-State Leukemia Survey and a mathematical model, the hypothesis that low levels of diagnostic radiation produce severe genetic damage that is expressed in the child of the exposed person as leukemia and other diseases is tested. It is estimated that for about 1% of the exposed persons who are affected by radiation, there is a 50-fold increase in the risk of leukemia and a five-fold increase in certain other diseases.

Adolescent