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At least 1,171 records · Page 65Linked to original sources
PubMed1990

[The effect of chronic internal irradiation from incorporated radionuclides on liver function].

On chronic supply to the body of a mixture of nuclear division products lanthanum-140, barium-140, tellurium-132, neodymium-147, neptunium-239, zirconium-95, niobium-95, iodine-131, cerium-141, -144, cesium-134, -137, and ruthenium-103 are detectable in liver tissue within the first months. In the 2 to 4 years following the disaster, liver tissue primarily accumulates cerium-144, radium-226, thorium-228, -232, ruthenium-106, antimony-125, and europium-154. Within the first periods the liver radionuclide content was 19 to 31% higher than that in the blood, and in the following years it was 24 to 38% higher. The radionuclides indicated were actively excreted with the bile into the gastrointestinal lumen. Within the first months after the chronic internal radiation the functional liver disorders were detectable in 30 to 40% of the patients. Later on diverse acute and chronic diseases of the liver, gallbladder and pancreas were detectable in 20 to 30% of the patients. The radionuclide content in the body was found to be in parallel with functional liver disorders. Acceleration of radionuclide excretion from the body results in liver function improvement.

Bile↗
PubMedDate not supplied

[Evaluation of the exposure levels to radioactivity in the hot-spring environment of the Island of Ischia during a year].

It is known that the decay products of the U-238 are findable in nature in certain materials (such as tufa, limestone, etc.), therefore some populations are naturally exposed to radiations originated by building materials, houses and isotopes present in drinking-waters. It is evident that, for example, the residents of Campania or Lazio will be involved, on such conditions and during their whole life, in the action of natural radiations of decay products of Uranium and consequently of Radon, which is originated and, as gas, also findable in the air of those indoor areas, at a concentration inversely proportional to the relevant ventilation factors. Furthermore, it is known that this isotope is always found in thermal waters too and sometimes at levels which make them classify as radioactive and with therapeutic properties still subjects of studies and researches. Actually, presence of Radon in warm waters is particularly evident in some basins (the Baths of Badgastein in Austria) and is also findable in some italian thermal towns such as Merano Laurisia, Abano, Baths of Lucca or the island of Ischia itself. All underground waters and especially the warm ones, including, those of Ischia basins, hold radioactive isotopes, since their composition is related to the nature of the underground, which they come from, and is strongly influenced by the kind of rocks present in that area, by the granulometry of the geological strata or by existent fractures, by flow speed and finally by solubilization capacity. On such conditions it is evident that all waters, during their scouring, will be enriched by Radon 222 (a gaseous, therefore more soluble, element); just because of its physical state, it will be more present in external environment in case of warm waters such as those ones now examined. Consequently the environmental state from a radioecological point of view of the utilized waters has to be considered, as well as any other thermal resort, fundamentally due to Radon (Rn) and to the relevant decay products. As a matter of fact, whereas from the family of Uranium come Radon (Rn 222), Lead (Pb 210) and Polonium (Po 210), these last two, respectively with halving-times of 22.3 years and 138.4 days, from the family of Thorium (Th 232) originates Radon (Rn 220 in past times defined "Toron" according to its "forebear") and Lead (Pb 212 with a halving-time of 10.6 hours).(ABSTRACT TRUNCATED AT 400 WORDS)

Background Radiation↗
PubMedDate not supplied

[Determination of americium-241 in urine].

A technique has been developed for the determination of americium 241 in urine by a radiochemical purification of the nuclide from uranium (upon co-precipitation of americium 241 with calcium and lanthanum), plutonium, thorium, and polonium 210 (upon co-precipitation of these radionuclides with zirconium iodate). alpha-Radioactivity was measured either in a thick layer of the americium 241 precipitate with a nonisotope carrier or in thin-layer preparations after electrolytic precipitation of americium 241 on a cathode.

Americium↗
PubMed1987

[Basophil leukemia, development of a chronic myeloid leukemia. Apropos of a case and review of the literature].

Basophilic leukemia is a rare disease accounting for less than 2% of all hematopoietic malignancies and little is known about the best therapeutical approach. We report a case of basophilic leukemia occurring as an accelerated phase of chronic myelogenic leukemia in a 50 year old man with a past history of uranium and thorium exposure. He was successfully treated with intensive chemotherapy and total body irradiation followed by autologous peripheral stem cell transplantation. Such an approach has never been reported in this disease. However, the benefit on survival could not be evaluated because of a fatal opportunistic infection. The cases of basophilic leukemia reported in the literature are discussed.

Basophils↗
PubMed1985

Measurement of centripetal migration of normal corneal epithelial cells in the mouse.

Fine punctate marks were made in normal corneas of mice using a needle rotating in a mixture of India ink and thorium dioxide. After 7 days, the marker was visible in the stroma and also in epithelial cells which had moved away from the stromal marks and towards the center of the cornea. The mean distance between these labels at the end of 7 days was 94 microns +/- 14 (SEM). The median distance migrated was about 17 microns per day. This figure represents the distance through which superficial and wing cells had migrated; the distance migrated by basal cells was not determined.

Animals↗
PubMed1977

[Radiotoxicological surveillance of personnel occupationally exposed to the hazards of internal radiocontamination in a nuclear center].

At the Casaccia Nuclear Centre the personnel occupationally exposed to a risk of internal contamination from radioactive substances is controlled by means of periodic radiotoxicological analyses. About 30,000 analyses of natural uranium, enriched uranium, thorium, gamma emetters, plutonium, americium, etc. in urine have been carried out since 1962. In the case of accidental acute radiocontamination by inhalation, wound and ingestion, special control on urine, blood, feces, nasal swabs, etc. must be schedules. The results can be very useful to the medical staff in order to take the most suitable therapeutical measures or to calculate the body burden.

Air Pollutants, Radioactive↗
PubMed1981

Permeability of the midgut basal lamina in the mosquito, Culex tarsalis Coquillett (Insecta, Diptera).

The permeability of the basal lamina of the midgut of the mosquito, Culex tarsalis, was determined for engorged and unfed mosquito midguts both pre- and postfixed. A range of materials, with diameters from less than 2nm (lanthanum) through 90 nm, (polystyrene spheres), was examined. The permeability of the basal lamina was constant under all experimental conditions; 5--8 nm particles (colloidal thorium) were the largest to consistently permeate. The discussion is centered on the question of how a virus particle, often 10 times the diameter of the established permeability limits of the basal lamina, can traverse this structure. Possible explanations are: 1. The basal lamina is a dynamic, plastic structure that easily distorts under physical and/or biochemical stresses, 2. The virion may possess enzymatic activity that locally alters the structure of the basal lamina, or 3. The extracellular surfaces of the midgut epithelium or the basal lamina itself may possess enzymatic properties that alter the size or possibly the structure of the virion as it passes through.

Animals↗
PubMed1984

[Clinicopathological study on 100 Japanese patients with peritoneal mesothelioma in Japan].

We report a clinicopathological study on 100 japanese patients with peritoneal mesothelioma encountered between 1911 and 1982. Fifty-six were males and 44 were females, they ranged in age from 10 months to 83 years. As the inducement materials, asbestos was reported in 5 and thorium in 2 patients. Clinical symptoms were abdominal distension in 56 and abdominal pain in 50 patients. Thrombocytosis and hypoglycemia were observed in 7 and 3 patients, respectively. Macroscopically, the peritoneal mesothelioma was localized in 7, diffuse in 86 and not described in 7 patients. The pathological classification was benign in 5 and malignant in 77 cases. According to Stout's classification, the peritoneal mesothelioma was tubular in 43 mixed in 25 and fibrous type in 11 cases. Based on our findings we suggest that peritoneal mesotheliomas are on the increase in Japan.

Adult↗
PubMed1982

Hydrodynamic injury of the endothelium in acute aortic stenosis.

The acute effects of increased shear stress on the endothelium were studied by reducing the lumen of the rat aorta to 20-25% of normal by means of metal clips. Intimal damage in the stenotic area was assessed by light microscopy after perfusion with AgNo3 and study of the endothelium en face. Most of the endothelium was lost within 3 minutes; the extent of the damage was not increased after 1 hour. Electron-microscopic examination showed that some endothelial cells became permeable to tracers (thorium dioxide and horseradish peroxidase); platelets adhered to the exposed internal elastic membrane. Focal endothelial changes were represented by myelin figures of various kinds arising from the luminal surface and by "cellular ulcers," superficial erosions of the endothelial cells accompanied by localized cytoplasmic changes. These "ulcers" occurred more frequently over the nucleus and near junctions; they have not been described in other forms of arterial injury.

Animals↗
PubMed1995

Neutron activation study of the natural elementary composition of edible sea urchins (Paracentrotus lividus Lamarck) in the National Park of Port-Cros (Mediterranean, France).

Neutron activation study of elementary composition was performed on edible sea urchins Paracentrotus lividus from the National Park of Port-Cros. The analysis allows the identification and quantification of 22 elements: antimony, arsenic, baryum, bromine, cerium, chromium, cesium, cobalt, gold, iron, lanthane, potassium, sodium, rubidium, samarium, scandium, selenium, silver, strontium, thorium, uranium and zinc. The concentration levels were higher in the soft organic parts (alimentary canals and gonads) for all the elements, except for strontium, which developed a strong affinity with calcareous hard parts (tests, spines, masticating apparatus). We also found high rates of baryum, arsenic, zinc, bromine and iron. The hypothesis on the origin of these elements is discussed. The data obtained on this referential zone will soon be used to appreciate the perturbation of the elementary composition of urchins by pollution in various parts of the French seashore.

Animals↗
PubMed1995

[Hepatic angiosarcoma: a report of a case associated with treatment with arsenic salts and a review of the literature].

Hepatic angiosarcoma is an infrequent neoplasm representing 1-3% of all the primary liver cancers. One fourth of the cases have demonstrated a relation with chemical carcinogens with the most frequent being thorium dioxide (thorotrast) and vinyl chloride. The case of an hepatic angiosarcoma which presented as an intraperitoneal hemorrhage in a patient who had undergone treatment with Neosalvarsán (dioxidiaminoarsenobenzol) 46 years beforehand is reported. The previous published reports include 6 cases of hepatic angiosarcoma related with treatment with arsenic salts and 4 cases in whom exposure was environmental.

Arsenicals↗
PubMed1993

Primary angiosarcoma of the urinary bladder.

Angiosarcoma of the urinary bladder is an extremely rare neoplasm with only 5 cases having been reported in literature so far. The etiologic factors implicated in visceral angiosarcoma are exposure to thorium dioxide, arsenic, polyvinyl chloride, irradiation, chemotherapy and the presence of retained foreign body material. The histologic picture is characterised by irregular vascular channels showing anastomoses and lined by atypical endothelial cells. The prognosis of this neoplasm is uniformly poor. Herein we report a case of primary angiosarcoma of the bladder in a man who had no prior exposure to any of the etiologic factors and is disease free 8 months after treatment with partial cystectomy and adjuvant postoperative pelvic irradiation.

Hemangiosarcoma↗
PubMed1996

The role of lysosomes in the selective concentration of mineral elements. A microanalytical study.

The role of the lysosome during the intracellular concentration of diverse mineral elements has been evidenced by the electron probe X-ray microanalysis (EPMA). This highly sensitive technique allows an in situ chemical analysis of any chemical element with an atomic number greater than 11, present in ultra-thin tissue sections. Therefore, it has been demonstrated by using this EPMA that 21 out of the 92 elements of the periodic table, once injected in a soluble form, were selectively concentrated within lysosomes of several types of mammalian cells. Amongst these 21 elements, 15 are concentrated and precipitated in an insoluble from in association with phosphorus whereas the other 6 are precipitated in association with sulphur. Amongst the 15 elements which precipitate with phosphorus in lysosomes, there are: 3 group IIIB elements of the periodic system, (aluminium, gallium and indium); the rare-earth elements (cerium, gadolinium, lanthanum, thulium and samarium); 2 group IVA elements (hafnium and zirconium), two actinides (uranium and thorium) and elements such as chromium and niobium. The 6 elements which precipitate with sulphur comprise the 3 group VIII elements of the classification (nickel, palladium, platinum) and the 3 group IB elements (copper, silver and gold). The mechanisms responsible for this selective concentration involve enzymatic processes and predominantly acid phosphatases for elements precipitating as phosphates and arylsulfatases for elements precipitating with sulphur.

Cell Compartmentation↗
PubMed1996

[Ways to reduce radiation doses caused by radon during exploration of gas and oil fields in the North].

Analysis of literature data and the personal studies of oil and gas extraction enterprises proved that the radiation environment depends mainly on natural radionuclides (uranium-238, thorium-232, potassium-40) incorporated into soil, deposit water, oil, gas and construction materials. Radioactive barytic accumulations in compressor pump tubes appeared to b a possible cause for significant background gamma-irradiation (up to 3,000 microR/hr and more; Neftekoumsk town of Stavropol area). Major radiation dose received by personnel in such cases results mainly from radon-222 and its derivatives, that should be considered in placement of living area, location of industrial and special compartments, water extraction sites. The places with minimal rate of radon emission are recommended for such purposes. To decrease radiation doses associated with gas and oil extraction in the North, the authors suggested a scheme of radiation control and listed all the equipment necessary.

Air Pollutants, Radioactive↗
PubMed1996

[Henri Beckquerel's discovery of radioactivity, and history of nuclear medicine. 100 years in the shadow or on the shoulder of Röntgen].

In 1896 Henri Becquerel discovered that uranium emitted penetrating rays similar to X-rays. His finding started a series of discoveries that were rewarded with numerous Nobel prizes. Marie and Pierre Curie found that thorium was radioactive too, and discovered and described two new elements, polonium and radium. They also found that radioactive radiation could be separated into alpha, beta and gamma rays. In 1993 their daughter Irene Joliot-Curie and her husband Frederic Joliot managed to produce radioactivity artificially by bombarding atomic nuclei with alpha particles. Enrico Fermi did likewise, but bombarded the nuclei with neutrons. In the cyclotron invented by Ernest Lawrence, radioactive isotopes were produced by proton bombardment. The ability to produce radioisotopes of different elements initiated a variety of tracer studies in biology and medicine. The number of studies increased exponentially when the nuclear reactor in Oak Ridge, US, was opened for radionuclide production in 1946. This article summarises the history of the application of radionuclides in science and medicine internationally and in Norway until now.

History, 19th Century↗
PubMedDate not supplied

Factors affecting use of CR-39 surface monitor technology to estimate past exposure to indoor radon.

In an epidemiologic study investigating influences of life-style and environment on lung cancer risk, CR-39 alpha-particle detectors, identified here as surface monitors, were affixed to subjects' selected household glass, ceramic, or enameled objects to measure residual radioactivity form embedded radon (Rn) decay products. The purpose was to estimate past cumulative indoor Rn concentrations to which the object was exposed to infer past exposures of the subjects. This approach was used to supplement exposure information obtained by methods traditionally used in Rn epidemiologic studies. In addition, surface monitors were affixed to objects of selected study subjects with complete exposure information to evaluate whether surface monitors provided estimates of cumulative past residual Rn exposure comparable to estimates obtained from year-long, ambient alpha track-etch measurements in each present and previous residence. These ambient measurements were time-weighted to estimate integrated exposure of objects and were adjusted for decay and ingrowth so as to be comparable to surface monitor measurements. A regression relationship was estimated between the two estimates of cumulative RN exposure. Surface monitor measurements had a satisfactory correlation (0.63) with adjusted ambient Rn measurements for new, nonceramic objects. Although not included in the study design, factors that might affect use of the technology were also investigated. Regression relationships were compared in graduated smoking environment (as judged by the subjects) to investigate possible differential plate out of radon progeny. In addition, regression relationships for windows were compared with those for other objects to investigate whether there was a significant difference between windows and other objects. It has been suggested that windows may have a higher plate out rate because of locally increased air flow. Results suggested that surface monitor information was useful to fill time gaps in estimates of historical radon exposure data obtained by ambient measurements. Glass samples provided the best correlation. Ceramic materials sometimes provided excessively high radon estimates, probably due to glazes that contained significant uranium or thorium. Due to small sample sizes, investigations of other factors were inconclusive.

Air Pollutants, Radioactive↗
PubMed1998

Ocular neuromyotonia: three case reports with eye movement recordings.

The objective of this article was to evaluate the etiologies, findings, and treatment of ocular neuromyotonia (ONM) in three case reports. The etiologies of ONM were determined by the histories, neuroradiologic tests, or biopsies. Clinical observations, videotaping, and electronic eye movement recordings documented the eye movement abnormalities. Intermittent diplopia developed several years after myelography with thorium dioxide (Thorotrast), radiation treatment for a pituitary tumor, and radiotherapy for medulloblastoma of the posterior fossa. All of the patients had intermittent, variable tropias that occurred spontaneously or were induced by eccentric gaze. One patient had a partial third nerve palsy, and another had a unilateral internuclear ophthalmoplegia (INO). ONM involved the paretic third nerve, extraocular muscles, and ipsilateral lateral rectus muscle in one patient, the paretic medial rectus muscle (INO) in one patient, a lateral rectus muscle (INO) in one patient, and a lateral rectus muscle in the last patient. Eye movement recordings were consistent with spasms of the involved muscles. Carbamazepine (Tegretol) abolished the ONM in two patients. The other patient had been taking carbamazepine for seizures and developed ONM when the dose was decreased. Increasing the dose abolished the ONM. ONM is an unusual cause of intermittent diplopia and strabismus, but its distinctive history and signs identify it easily. Damage to the peripheral cranial nerves might produce segmental demyelination, axonal hyperexcitability, and a self-perpetuating, reverberating circuit that causes spasms of the extraocular muscles.

Aged↗