Reflexiones sobre la etiología de la leucemia / Raminisence about leukemia etiology

Se ha detectado un agrupamiento de 52 casos de leucemia y 22 de linfoma no-Hodgkin en niños, calculado en 10 veces lo esperado, en el área de la planta nuclear de Sellafield en Inglaterra; se lo ha relacionado con la exposición sostenida a radiaciones de los padres de estos niños antes de la concepción. Estas observaciones me recordaron experimentos que hicimos en la década del '60 con 32p en ratones BALB/c. Con dosis superiores a 40 *Ci inoculadas a madres durante la preñez, la cría resultó ser estéril, por daño de las espermatogonias en los machos y luteinización del ovario en las hembras. Además, el 45% de los animales desarrollaron leucemia con una latencia de 18 meses. En experimentos posteriores se indujo leucemia con diversos procedimientos, incluyendo la inoculación intraesplénica de leucemia/linfoma humanos, la inmunización con Sarcoma 180, rayos X, etc. Todos los animales leucémicos expresaban el virus de Gross, detectado por anticuerpos anti-G. Experimentos más recientes con estimulación antigénica crónica sugieren la siguiente secuencia: alorreactividad, autoinmunidad, leucemia. La explicación del mecanismo involucrado permanece controvertida. Inicialmente se habló de la activación del virus de Gross, luego del oncogenes eran celulares y no virales, se los incriminó de diferentes maneras. Recientemente, con el descubrimiento de los anti-oncogenes o genes supresores de tumor, se habla de una cascada de eventos génicos, tanto efectores como supresores

Reflexiones sobre la etiología de la leucemia / Raminisence about leukemia etiology

Se ha detectado un agrupamiento de 52 casos de leucemia y 22 de linfoma no-Hodgkin en niños, calculado en 10 veces lo esperado, en el área de la planta nuclear de Sellafield en Inglaterra; se lo ha relacionado con la exposición sostenida a radiaciones de los padres de estos niños antes de la concepción. Estas observaciones me recordaron experimentos que hicimos en la década del 60 con 32p en ratones BALB/c. Con dosis superiores a 40 *Ci inoculadas a madres durante la preñez, la cría resultó ser estéril, por daño de las espermatogonias en los machos y luteinización del ovario en las hembras. Además, el 45% de los animales desarrollaron leucemia con una latencia de 18 meses. En experimentos posteriores se indujo leucemia con diversos procedimientos, incluyendo la inoculación intraesplénica de leucemia/linfoma humanos, la inmunización con Sarcoma 180, rayos X, etc. Todos los animales leucémicos expresaban el virus de Gross, detectado por anticuerpos anti-G. Experimentos más recientes con estimulación antigénica crónica sugieren la siguiente secuencia: alorreactividad, autoinmunidad, leucemia. La explicación del mecanismo involucrado permanece controvertida. Inicialmente se habló de la activación del virus de Gross, luego del oncogenes eran celulares y no virales, se los incriminó de diferentes maneras. Recientemente, con el descubrimiento de los anti-oncogenes o genes supresores de tumor, se habla de una cascada de eventos génicos, tanto efectores como supresores (AU)

Valoración del riesgo ocupacional por exposición a campos electromagnéticos en trabajadores que aplican el tratamiento con diatermia / Assessment of occupational risk due to exposure to electromagnetic fields in workers applying the diathermy treatment

Se midieron los valores de intensidad de los campos eléctricos y magnético, generados durante la aplicación diatermia a pacientes en las áreas de fisioterapia de 7 hospitales. Se hicieron observaciones y se realizó una revisión bibliográfica. A partir de esa información se hizo una valoración del riesgo ocupacional en esos puestos de trabajo. Son brindadas recomendaciones para disminuir el riesgo

Valoración del riesgo ocupacional por exposición a campos electromagnéticos en trabajadores que aplican el tratamiento con diatermia / Assessent of occupational risk due to exposure to electromagnetic fields in workers applying the diathermy treatment

Se midieron los valores de intensidad de los campos eléctricos y magnético, generados durante la aplicación diatermia a pacientes en las áreas de fisioterapia de 7 hospitales. Se hicieron observaciones y se realizó una revisión bibliográfica. A partir de esa información se hizo una valoración del riesgo ocupacional en esos puestos de trabajo. Son brindadas recomendaciones para disminuir el riesgo

Models and assumptions underlying genetic risk assessment.

Various methods employed for estimating the genetic risks of radiation are reviewed. With the doubling-dose method, genetic damage is expressed as an increase in cases of known genetic disease. The actual doubling dose is based on figures obtained with the mouse. There have been no recent data on induced mutation frequencies. Recent results suggest that the prevalence figure for multifactorial disease may be at least one order of magnitude higher than before. Various assumptions underlying the doubling-dose concept are discussed in the light of recent findings on: (1) spontaneous mutations resulting from insertion elements, and (2) the comparability between spontaneous and induced mutations. The so-called direct method makes use of figures for induction of dominant mutations affecting the skeleton and the lens of the eye in the mouse, and of translocation induction in monkeys. Induction rates are converted to overall rates of induced dominant effects in man by applying certain assumptions. The proportionality between dose and effect is the basis for all genetic risk assessments. The possible significance of data on human lymphocytes indicating a threshold below 4 rad and the induction of repair enzymes by low radiation doses is discussed. The parallelogram approach is based on the principle that estimates can be obtained on the amount of genetic damage that cannot always be assessed directly. Thus mutations in mouse germ cells can be predicted by using mutation frequencies in cultured mammalian cells and O6-ethylguanine adducts. Measurement of haemoglobin mutations in human and mouse erythrocytes, and of HPRT-deficient mutations in lymphocytes of man and mouse should make more precise estimates of mutation frequencies in human germ cells possible. The development of a database on mutations in somatic cells of the mouse, their induction frequencies and molecular nature are considered an important priority. Used in combination with mouse germ-cell mutation frequencies, they should enable more precise risk estimates on the basis of mutations in somatic cells of man.

An epidemiologic survey of senile cataract in China.

This paper is based on data obtained in blindness screening in 7 rural areas throughout China and presented at the Second National Conference of the Chinese Ophthalmologic Society in 1979. This comparative study of the incidence of senile cataract in relation to geographic and meteorologic factors, with special reference to solar radiation, indicates that cataract incidence increases with decrease in latitude or increase in altitude due to increased solar radiation. Zedang in Tibet, with the highest altitude and low latitude (29 degrees N) has the highest incidence (1.32%) of the areas surveyed, followed by Aleitai 0.25% and Zhongshan (0.23%), whereas the incidences in lowland areas are between 0.12 and 0.14%, the lowest surveyed being in Zhongmou (0.066%). The differences in cataract incidence are apparently associated with solar radiation. Yu and coworkers in their research demonstrated the evidence for the solar UV-induced lowering of sulfhydryl level in the Tibet human lens nucleus. Therefore, these findings furnish some evidence supporting the theory that sunlight enhances cataract formation.

The serotonin irritation syndrome--a new clinical entity?

The literature on the possible existence of a "serotonin irritation syndrome" is examined. This syndrome is an anxiety state occurring in the presence of elevated levels of atmospheric or ambient cations and is associated with elevated central and peripheral serotonin levels. Investigation of these cations' effects on microbes, insects, and mammals, including humans, shows a disruption of normal activity. It is suggested that clinicians become acquainted with the potential relationship between cation exposure and serotonin in their treatment of anxious patients. Further research exploring the etiology and diagnostic definition of this entity is urged.

Interference in pacemakers.

We attempt here to outline the different sources of interference and the methods of interference detection and protection with their advantages and disadvantages. A proposal is made as to how a better interference suppression could be established. A comparison of 16 pacemakers from ten manufacturers tested with different interference sources revealed a great variety, which does not allow one to generalize the problem of interference. As an example, an electric steel furnace with its magnetic field is described and how its influence on pacemakers can be estimated. Rules are given as to how pacemaker patients may be treated by electrotherapy. A test procedure for characterizing the specific interference behavior is proposed.

Effects of physical forces on the reproductive cycle. Council on Scientific Affairs.

The Council on Scientific Affairs is aware that physicians, as well as the public in general, have expressed increasing concerns regarding the possible adverse effects of various physical forces on the reproductive organs. Various channels of public communication report anecdotal episodes of suspected cause-and-effect relationships between various physical elements in the environment and harmful effects on reproduction. Many of these episodes have not been substantiated by acceptable scientific research. However, some reports have appeared in the scientific literature that do document adverse reproductive effects on humans and animals at certain levels of some physical forces. At levels above 3,636 m (12,000 ft), adverse reproductive effects have been observed in men and women, in the conceptus, and in certain species of animals. Hyperthermia in excess of 40 degrees C may affect the man and the conceptus, as well as the reproductive capacity of certain animals. However, adverse effects of hypothermia have been observed only in animals. Ionizing radiation can cause injury to the man, woman, and conceptus and to animals, depending on dose and duration of exposure. There have been no well-documented injurious effects to the human reproductive organs resulting from radiofrequency-microwave radiation, but there have been some reports in animals that attributed untoward reproductive limitations to thermal effects. To date, there have been no reports in the scientific literature to implicate electronic and magnetic fields, gravity and acceleration, noise, optical radiation (UV, visible, infrared, and lasers), ultrasound, or vibration as having harmful effects on reproduction in either humans or animals. There is need for more well-designed and controlled studies to be performed in all of these areas of exposure at maximum-tolerated levels to physical force before it can be determined with certainty that no ill effects will accrue to the reproductive cycle, especially in assessing harmful effects from low-level exposure during long periods of time.