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Biomedical subjects

P Brunner

Publications and source records attributed to P Brunner.

At least 37 records · Page 2Linked to original sources
PubMed1995

Mitigation of indoor radon in an area with unusually high radon concentrations.

In an area of unusually high indoor radon concentrations of up to 270,000 Bq m-3, four houses were selected for mitigation of indoor radon. Methods used were basement sealing, soil depressurization, a mechanical intake and outlet ventilation system with heat exchanger in the basement, and a multilayer floor construction using a fan to suck radon from a layer between bottom slab and floor. Basement sealing proved unsuccessful, the radon concentration remained unchanged after the mitigation attempt. The most successful remedial measure was soil depressurization using two fans and loops of drainage tubes to withdraw radon from the region under the floor and outside the walls of the basement and from soil under the part of the house without a basement. This method reduced the basement radon level in winter by about a factor of 200, i.e., from 100,000 Bq m-3 to 500 Bq m-3, and the ground-floor level by about a factor of 400. As regards the mechanical intake and outlet ventilation system with heat exchanger in the basement, it is essential to ensure that ventilation provides increased air pressure in the basement compared to outdoors. Unbalanced mechanical intake and outlet ventilation may decrease the air pressure indoors compared to outdoors, leading to increased radon concentrations. Optimization of this method reduced radon concentrations from 200,000 Bq m-3 to 2,000-3,000 Bq m-3 in winter. In one house with only a very small basement, a multilayer floor construction using a fan to suck radon from a layer between the bottom slab and floor was found to reduce radon concentrations on the ground floor from 25,000 Bq m-3 to about 1,700 Bq m-3 in winter. The results show that even in areas with extremely high radon concentrations, effective mitigation of indoor radon can be accomplished if suitable techniques are used. The evaluation of the different mitigation methods shows good coincidence with the ICRP 65 report.

Air Pollutants, Radioactive↗
PubMed1995

[Giant bronchopyocele. General and radiological characteristics. Apropos of a case].

A case of giant bronchocele is reported. This lesion is due to a mucus and pus filled dilatation of the bronchial tree proximal to a stenosis. The latter can be either congenital or acquired, or in the context of a diffuse bronchopathy, which can be responsible for a functional stenosis. Both plain radiography and computed tomography findings are diagnostic. The etiology of the abnormality however represents an important problem to be solved. Further, a thoractomy is often necessary, except in those case arising in the context of a diffuse bronchopathy, which usually resolve either spontaneously or following medical treatment.

Bronchi↗
PubMed1994

Unusually high indoor radon concentrations from a giant rock slide.

In a village in western Tyrol, Austria (Umhausen, approximately 2600 inhabitants) unusually high indoor radon concentrations were measured. The medians were found to be 3750 Bq/m3 (basements) and 1160 Bq/m3 (ground floors) in winter, and 361 Bq/m3 (basements) and 210 Bq/m3 (ground floors) in summer. Maximum radon concentrations of up to 274,000 Bq/m3 were registered. The unusually high radon concentrations are due to the geology of the locality. The part of Umhausen with the highest radon concentrations is built on an alluvial fan of a giant rock slide (granitic gneiss). Measurements of the radon exhalation rate from soil showed a median of 0.4 Bq/m2/s, measurements of the radium content of rock samples yielded a median of 125 Bq/kg. The material of the rock slide is heavily fractured so that an elevated emanating power and an increased diffusion coefficient for radon in soil must be assumed. Given a diffusion coefficient of 8 x 10(-6) m2/s and an emanating power of 0.3, the median exhalation rate of 0.4 Bq/m2/s is obtained at a radium concentration of 125 Bq/kg. The rock slide is therefore considered to be the main source of radon. The abnormally high radon concentrations in Umhausen coincide with a statistically significant increase in lung cancer mortality (age and sex standardized mortality rate = 3.9, 95% C.I.: 2.9-5.1); the control population is the population of the entire Tyrol (630,000 inhabitants).

Air Pollution, Indoor↗
PubMed1994

Magnetic resonance imaging of von Meyenburg complexes: report of a pathologically documented case.

Von Meyenburg complexes (VMC) are rare malformations of the bile ducts. They are usually associated with adult dominant polycystic disease (ADPCD). Although generally benign, they may give rise to cholangiocarcinomas. Herein, we report the third MR documented case of VMC. The comparative diagnostic value of ultrasound (US), computed tomography (CT), and magnetic resonance (MR) examinations is discussed.

Aged↗
PubMed1994

High indoor radon concentrations in an Alpine region of western Tyrol.

In a village in western Tyrol, Austria (Umhausen, 2,600 inhabitants), unusually high indoor radon concentrations were measured, and the lung cancer mortality rate was found to be higher than that of the total population of Tyrol (620,000 inhabitants). Annual means of radon concentrations were found to be particularly high in the area between the two rivers Otztaler Ache and Hairlachbach, geologically an alluvial fan of a giant rock slide of granitic gneisses (area A, median of annual means on the ground floors: 1,868 Bq m-3); radon concentrations were comparatively low in the rest of the village (area B, median of annual means on the ground floors: 182 Bq m-3). On the basis of these medians, the annual exposures were calculated according to the ICRP model (area A: 58.8 x 10(5) Bq h m-3; area B: 5.7 x 10(5) Bq h m-3). Data taken from the Cancer Registry of Tyrol were used to determine the age- and sex-standardized lung cancer mortality rate (area A: 6.17; area B: 1.43).

Air Pollution, Indoor↗
PubMed1992

Increased radon concentrations in classrooms used for pottery workshops.

In a pilot study of nine schools the radon (Rn) concentrations were measured systematically. The mean radon concentrations in the classrooms on the ground-floor and on higher floors was 52 Bq/m3, which is equivalent to the mean values in Central Europe. Several of the basement rooms used for handicraft lessons had significantly increased Rn levels with a mean concentration of 617 Bq/m3. In all other parts of the basement Rn levels were clearly lower with a mean concentration of 136 Bq/m3. In the rooms used for handicraft lessons numerous articles of pottery were on display. After removing these the Rn in air concentration was reduced to a mean value of 83 Bq/m3.

Air Pollution, Indoor↗
PubMed1992

[Adherence of pacemaker electrodes to the endomyocardium--a postmortem study].

The weight of extraction of a pacemaker electrode from the endomyocardium was evaluated in 29 hearts (31 pacemakers). The maximum weight of extraction was 2375 g, the mean being 760 g. The weight of extraction depends on the duration of the implantation of the pacemaker, and on the thickness of the right ventricle, but there is no relationship to the shape of the pacemaker electrode, nor to the site of insertion in the right ventricular endomyocardium. In half the cases, pieces of endomyocardium adhered to the extracted electrode, the largest piece being 5 cm x 0.5 cm x 0.5 cm. The epicardium was not injured in any of these cases. It was often noticed that scarred adhesions existed between the cable of the pacemaker and the endocardium and/or the intima of the blood vessels. During traction in vivo, strangulation of the right heart and the blood vessels may occur.

Aged↗
PubMed1991

Beneficial effect of liposome-encapsulated muramyl tripeptide in experimental septicemia in a porcine model.

In a porcine model of pneumococcal septicemia, animals were pretreated with 1 mg of liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (MTP-PE) or with liposomes alone. After 24 h each animal received an injection of either 10(9) or 10(10) pneumococcal serotype 6B cells. MTP-PE pretreatment resulted in less pronounced leukocytopenia, with a nadir of 6,700 (versus 4,100) leukocytes per mm3 after injection of 10(9) bacteria and a nadir of 4,400 (versus 3,800) leukocytes per mm3 after injection of 10(10) bacteria. At the same time bacterial clearance was substantially improved by MTP-PE pretreatment. Finally, pretreatment with MTP-PE dramatically reduced mortality; the average death rates for both series of animals used were 55% for liposome-pretreated animals and 3% for animals pretreated with MTP-PE-containing liposomes. These results in a preclinical model suggest that treatment with MTP-PE-containing liposomes might be beneficial in controlling septicemia in patients at risk.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

Chernobyl fallout on Alpine glaciers.

Measurements of the gross beta activity of snow samples from four Alpine glaciers contaminated by radioactive fallout from the Chernobyl nuclear accident and a gamma-spectrum analysis of selected samples are reported. The results are discussed with respect to possible risks to the population from using meltwater from these glaciers as drinking water.

Accidents↗
PubMed1989

Radiation sensitivity of Down's syndrome fibroblasts might be due to overexpressed Cu/Zn-superoxide dismutase (EC 1.15.1.1).

Trisomy 21 (Down's syndrome, DS) is the most frequent chromosomal aberration. Triplication of a small region of chromosome 21, the fragment 21q22 is sufficient to cause the DS phenotype including immunodeficiency, premature aging, neurodegenerations, mental retardation and an increased risk of leukemia. Chromosomal aberrations caused by X-ray irradiation were observed in DS lymphocytes and DS fibroblasts, but the correlation to cell death or repair deficiency was not clear. We approached this problem and report here on a profound X-ray repair deficiency of DS cells. With a colorimetric viability assay we observed an UV sensitivity of DS fibroblasts at doses beyond 14 Jm-2 but no significant X-ray sensitivity. By the nucleoid sedimentation technique, a deficient restoration of nucleoids in DS cells after X-ray irradiation was demonstrated. The same features apply for cells, which contain an overexpressed Cu/Zn-superoxide dismutase (SOD-1) gene. Radiation sensitivity of DS cells and SOD-1 overexpressing cells resemble those of ataxia telangiectasia (AT) fibroblasts. Additionally, DS and AT cells exert lack of inhibition of DNA synthesis after X-ray irradiation.

Cell Line↗
PubMed1988

Displacement of Chernobyl fallout in snow layers of temperate Alpine glaciers.

Measurements of the gross-beta-activity and a gamma-spectrum analysis of radioactive fallout from Chernobyl distributed in vertical snow profiles on an Alpine glacier were carried out. Samples were collected in summer 1986 and in summer 1987. A displacement of isotopes to depths of approximately 6 m was observed. The mean activity per unit area amounts to 10.4 and 6.6 kBq m-2 for samples from 1986 and 1987, respectively, both values corrected to 1 May 1987. Isotopes with half-lives shorter than 110m Ag (250 days) could no longer be detected in 1987.

Accidents↗