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Biomedical subjects

B L Cohen

Publications and source records attributed to B L Cohen.

At least 109 records · Page 6Linked to original sources
PubMed1984

Treatment of prolactinomas with megavoltage radiotherapy.

The outcome of treatment of 36 women with prolactinomas using megavoltage radiotherapy combined with interim dopamine agonists (bromocriptine, lysuride, pergolide) was reviewed; 16 of the women showed radiological evidence of a macroadenoma. The most common presenting symptom was secondary amenorrhoea; 26 of the patients had galactorrhoea. In 29 patients who wished to conceive the ovulation rate (as indicated by circulating progesterone concentrations) was 97% and the successful fertility rate 86%. No patient had enlargement of the tumour during pregnancy and there were no complications of radiotherapy. No further tumour enlargement was detected in serial skull radiographs, and an improvement in size of the fossa was noted in 45% of those assessed. When medical treatment was withdrawn a mean of 4.2 years (range 1-11) after radiotherapy in the 27 patients who had completed their families the serum prolactin concentration had fallen appreciably in 26 of them and later became normal in eight. The incidence of growth hormone deficiency rose from 24% of the whole group before radiotherapy to 79% afterwards. Only one patient required thyroxine, and one was receiving gonadotrophin. No patient became deficient in adrenocorticotrophic hormone. A regimen of megavoltage radiotherapy and interim bromocriptine allows women with prolactinomas safely to undergo pregnancy and results in the long term prospect of tumour shrinkage and control of hyperprolactinaemia.

Adenoma↗
PubMed1984

Perspective on genetic effects of radiation.

The BEIR -III estimates of genetic effects of radiation are combined with current estimates of radiation from the nuclear-energy industry to derive estimates of the genetic effects of the latter, and the results are put into perspective. All nuclear electricity would have genetic effects equivalent to those of increasing average parental age by 2.6 days (average age of parents shifted by 1.8 yr between 1940-1960), or of men spending 8 hr more per year wearing pants . If 0.5% of the taxes paid by the nuclear industry were used to combat genetic disease by currently available methods, this would avert 160 cases of genetic disease for each case caused by the nuclear industry. Using this money for genetic research would be even more profitable, by a large factor. It is pointed out that the activities of our generation have numerous impacts, both favorable and unfavorable, on future generations that are enormously more important than the genetic effects of our radiation. It is shown that the genetic effects of radiation cannot destroy the human race or create new type monsters. Genetic risks to children of radiation workers and non-radiation workers in the present generation are also treated.

Abnormalities, Radiation-Induced↗
PubMed1984

Probability for human intake of an atom randomly released into ground, rivers, oceans and air.

Numerical estimates are developed for the probability of an atom randomly released in the top ground layers, in a river, or in the oceans to be ingested orally by a human, and for an atom emitted from an industrial source to be inhaled by a human. Estimates are obtained for both probability per year and for eventual probability. Results vary considerably for different elements, but typical values for total probabilities are: ground, 3 X 10(-3); oceans, 3 X 10(-4); rivers, 1.7 X 10(-4); and air, 5 X 10(-6). Probabilities per year are typically 1 X 10(-7) for releases into the ground and 5 X 10(-8) for releases into the oceans. These results indicate that for material with very long-lasting toxicity, it is important to include the pathways from the ground and from the oceans.

Aerosols↗
PubMed1984

Radon concentrations inside public and commercial buildings in the Pittsburgh area.

Radon concentrations in ambient air from numerous schools, stores and other public and commercial buildings in the Pittsburgh, PA, area were measured by grab sampling. This is more appropriate than using long-term integrating monitors because of the correlation between times of occupancy and Rn levels. Results indicate that Rn concentrations in these buildings are nearly an order of magnitude less than in homes, and not much higher than outdoors. Variations among sites is also much less than for homes, probably because there is less variability in ventilation and building maintenance practices. Colleges and universities have somewhat higher Rn levels and a larger degree of variability than commercial buildings or hospitals. There was no indication of higher Rn levels in cold weather than in warm weather, or of correlations with the age of the building.

Air Pollutants↗
PubMed1983

Theory and practice of radon monitoring with charcoal adsorption.

Because of interest in charcoal adsorption as an inexpensive radon monitoring technique that may be suitable for mass data collection, the theory of radon adsorption from air by a charcoal bed is developed, giving numerical estimates at all stages. The method is practical down to air concentrations of about 0.1 pCi/l. A simple charcoal bed is limited by the fact that its response is highly sensitive to the time interval before termination of the exposure, but two simple methods of avoiding this problem are developed. Simple methods for determining the diffusion constant for the charcoal being used, and for optimizing the depth of the charcoal bed, are presented.

Adsorption↗
PubMed1983

Discounting in assessment of future radiation effects.

There is a question as to whether cancer fatalities to be experienced in the distant future as a result of radioactivity produced today should be treated on a par with those experienced now, or whether there should be discounting in analogy with accounting principles for money to be spent in the future. It is shown that recent trends in cancer cure rates justify about an 0.7% per yr discounting. Other rationales for discounting are developed. Money can, and always will be usable for saving lives; setting up a trust fund for future generations to use for this purpose is much more cost-effective than spending money now to reduce their exposure to radiation. The history of interest rates over the past 5000 yr indicates that at least 3% real annual interest can be expected. It may not be necessary to actually set up a trust fund as its purpose is largely accomplished by the decrease in the public debt when money is not spent. The trust fund approach is mathematically equivalent to discounting lives lost in the far future at 3% per yr. As an alternative to the trust fund, money can be invested in biomedical research. It is shown that per dollar spent, this is usually far more beneficial to the health of future generations than protecting them from radiation as that art is currently practiced, and for purposes of cost-benefit analysis, it corresponds to discounting lives lost in the future by a factor of the order of the number of years before they are lost; e.g. the number of lives calculated to be lost 1000 yr from now should be divided by 1000. Implementation of the biomedical research alternative requires only that about 0.1% of taxes from nuclear plants and 0.1% of government support for biomedical research be re-defined as contributions from nuclear plants to this research.

Female↗
PubMed1982

Effects of ICRP Publication 30 and the 1980 BEIR Report in hazard assessments of high-level waste.

ICRP Publication 30 (ICRP30) gives the radiation dose to various body organs in Sv per Bq, which are readily translated into rad per curie ingested for various radioisotopes; the 1980 BEIR Report (BEIR III) gives the risk of fatal cancer per rad of dose to each body organ; the ORIGEN 2 Code gives the curies per tonne of initial uranium fuel in high level waste and in spent fuel. The product of these, Ci/tonne x rad/Ci x risk/rad gives the risk/tonne in terms of fatal cancer doses, if ingested, per tonne of uranium. When the resulting curves are compared with those calculated previously (based on ICRP Publication 2 and the 1972 BEIR Report), the hazard is less for the first century but much more thereafter. The principal sources of this greatly increased hazard is the 100-fold increase in absorption through the gut for 237Np in ICRP 30, plus the high cancer risk from radiation to liver in BEIR III. Some consequences of these changes and some scientific questions relevant to ascertaining their validity are discussed.

Humans↗
PubMed1982

Radon daughter exposure to uranium miners.

Radon exposures to U.S. uranium miners under present conditions average about 1.3 WLM per year approximately or equal to 60 WLM per full working lifetime. This is intermediate between (a) the lowest exposures for which there have been excess lung cancers reported among U.S. miners (120-240 WLM) and (b) average environmental radon exposures (16 WLM), so models based on these two situations are used to estimate expected effects on present uranium miners. In Model A, the loss of life expectancy is 45 days, the SMR (standardized mortality ratio) for lung cancer is 1.10, and the SMR for all causes between ages 18 and 65 is 1.013. In Model B these are 10 days, 1.03 and 1.002 respectively. It is shown that the radon exposures to miners are similar to those to millions of Americans from environmental exposure, and that miner health risks are comparable to those of other radiation workers. Their lung cancer risk from radon is 7-50 times less than their job-related accident mortality risk, and represents 0.7-4% of their total risk in mining. Miners suffer from many diseases with SMR very much larger than that for radon-induced lung cancer, and there are many other occupations and industries with far higher SMR for lung cancer than that from radon exposure to miners.

Adult↗
PubMed1982

Applications of ICRP 30, ICRP 23, and radioactive waste risk assessment techniques to chemical carcinogens.

Linear, no threshold dose-response relationships at low doses are now accepted by U.S. Government agencies for risk assessment of chemical carcinogens. By application of ICRP30 metabolic models, ICRP23 data on ingestion intake of elements, and radioactive waste risk assessment techniques, it is shown that this predicts large numbers of eventual fatalities because of the high probability for material in the ground to eventually be ingested by humans. For example, a detailed for material in the ground to eventually be ingested by humans. For example, a detailed calculation shows that the cadmium released in U.S. coal burning in one year will eventually cause 20,000 fatal cancers (1000/GWe-yr of electricity production), the imports of cadmium into the U.S. will eventually cause 130,000 fatalities for each year of importing at the current rate, and CdS photovoltaic cells will cause 400 fatalities/GWe-yr.

Cadmium↗
PubMed1981

Further studies on pituitary and ovarian function in women receiving hormonal contraception.

Pituitary and ovarian function was evaluated in women receiving 3 combined oral contraceptive preparations. Basal levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) and gonadotropic responses to gonadotropic releasing hormone (GnRH) were studied in 36 healthy, regularly ovulating women in the early follicular and mid-luteal phases of their menstrual cycle (non-treatment, control). These same women were then divided into 3 groups with 12 volunteers in each. Each group received an oral contraceptive preparation cyclically for 3 months. The preparations were: Nordette (30 microgram ethinyl estradiol and 150 microgram d-norgestrel), Nordiol (50 microgram ethinyl estradiol and 250 microgram d-norgestrel) and Biphasil (50 microgram ethinyl estradiol and 50 microgram d-norgestrel X 11 days and 125 microgram d-norgestrel X 10 days). In the third month of treatment, the tests were repeated on day 21, i.e. after 21 active pills, and on day 28, i.e. after 21 active and 7 inactive tablets. On active therapy, basal FSH and LH were similarly suppressed in the 3 groups. LH had varied responses to a bolus of GnRH, whilst the FSH responses were similar in the 3 groups. After 7 days of inactive tablets, basal FSH and LH had returned to pre-treatment, early follicular phase levels. However, the LH responses to a bolus of GnRH varied in the 3 groups, but again, no differences were noted in the FSH responses. Basal FSH, LH and E2 recovered earlier in the Nordette group during the 7 days of inactive tablets.

Contraceptives, Oral↗