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R Winkler

Publications and source records attributed to R Winkler.

At least 55 records · Page 3Linked to original sources
PubMed1998

Temporal and small-scale spatial variability of 222Rn gas in a soil with a high gravel content.

To quantify the small-scale spatial and long-term temporal variability of the 222Rn concentration in a typical soil with a high gravel content, we monitored this radionuclide every week for 1 year, at 0.5 m and 1.0 m depth at nine sampling positions in a 20 x 20-m field, and at the four corners of a 1 x 1-m plot within this field. The data show that the 222Rn soil gas concentrations exhibited a spatial variability which is characterised in the 20 x 20-m field by coefficients of variation from 20 to 30% at 0.5 m depth, and from 15 to 20% at 1.0 m depth. Within the 1 x 1-m plot, these values were at both depths only 5-10%. In the winter months, the 222Rn soil gas concentration was higher at 0.5 m depth compared to that at 1.0 m depth. However, in the summer months, the opposite behavior was observed. Time series analysis of the data showed that the 222Rn concentrations in the soil gas determined at a given position and depth is strongly correlated with the preceding observation at this point. In addition, strong cross-correlations are present between the 222Rn concentration time series observed at different positions and depths. The above results are used to calculate the probability for estimating, within a given deviation, the annual mean 222Rn soil gas concentration from a single measurement on an arbitrary day of a given month at a limited number of sampling positions only. Because the 222Rn concentration in the soil gas can vary considerably even within 1 month, 222Rn measurement obtained only once in a given month (especially in January and February) can not be used to obtain a good estimate of the mean annual radon concentration, even if a large number of samples in the field are taken.

Air Pollutants, Radioactive↗
PubMed1998

Temporal variation of thoron decay product concentration in the atmosphere and comparison with radon decay product concentration.

Seasonal and long-term variation of the airborne 212Pb concentration, representative of the equilibrium equivalent concentration of thoron decay products (EECRn220), was investigated from 1989 through 1996 at a semi-natural location in southern Germany. Continuous measurement yielded a long-term average concentration of 0.082 Bq m-3, while daily mean concentrations varied from < or = 0.01 to 0.34 Bq m-3. An average annual effective dose of 1.4 mSv due to outdoor thoron progeny concentration was estimated. This is about 2% of the dose due to the average short-lived radon progeny concentration (EECRn222) of 8.4 Bq m-3 measured for this location in the same period. In most years the seasonal pattern of 212Pb activity concentration in the atmosphere is characterized by two maxima: the first in May and the second one in September. Low concentrations are observed from November through February of each year. This is in contrast to the behaviour of the short-lived 222Rn progeny which exhibit enhanced concentrations exactly during these months. The most probable reason for the different temporal behaviour of 212Pb is the extremely reduced flux of thoron gas from the ground during the winter months.

Air Pollutants, Radioactive↗
PubMed1998

Treatment of the budding yeast Saccharomyces cerevisiae with the lipid peroxidation product 4-HNE provokes a temporary cell cycle arrest in G1 phase.

The effects of 4-hydroxy-2-nonenal (HNE) on the cell division cycle were investigated in the yeast Saccharomyces cerevisiae. A short treatment with HNE at a concentration in the range of the IC50 value in S. cerevisiae SP-4 cells induced a significant increase in the proportion of G0/G1 cells at the expense of S-phase cells. A similar delay in cell cycle progression upon treatment with HNE has recently been shown for HL-60 neoplastic cells. Long-term exposure in a synchronized yeast culture resulted in a pronounced dose-dependent block between G0G1- and S-phase, probably at or close to a point in the cell cycle that has been designated as "START." Incorporation of radioactively labeled precursors of macromolecules revealed that DNA synthesis was most susceptible to HNE in comparison to RNA and protein synthesis. Production of glutathione appeared to be required for the continuation of the cell cycle. HNE-treated yeast cells reentered the cell cycle when their glutathione content exceeded about twice the level of control cells. The release from the cell division cycle delay was followed by an enhanced growth to an extent that HNE-treated cells exceeded the number of control cells. These results indicate that HNE causes a biphasic modulation of cell proliferation. It was concluded that this effect was conserved during evolution from yeast to mammalian cells, emphasizing once more the usefulness of this unicellular organism as a model system for the investigation of the effects of free radical-derived products on the proliferation of eukaryotes.

Aldehydes↗
PubMed1998

Immunoadsorption--a new therapeutic possibility for multiple sclerosis?

A 46 year old woman suffers from chronic progressive multiple sclerosis. She was diagnosed in 1993. Because of many complications seen in conservative treatment, plasma exchange was started. The expanded disability status scale by Kurtzke could be improved but the interval between the treatments became shorter and shorter. It was therefore decided to commence protein A immunoadsorption treatment. With this treatment the patient shows good and stable improvement in neurological and functional status with an acceptable treatment frequency of once every 3 weeks.

Chronic Disease↗
PubMed1998

A new intermediate in the mineralization of 3,4-dichloroaniline by the white rot fungus Phanerochaete chrysosporium.

Phanerochaete chrysosporium ATCC 34541 has been reported to be unable to mineralize 3,4-dichloroaniline (DCA). However, high mineralization is now shown to occur when a fermentation temperature of 37 degrees and gassing with oxygen are used. Mineralization did not correlate with lignin peroxidase activity. The latter was high under C limitation and low under N limitation, whereas the reverse was true for mineralization. The kinetics of DCA metabolism was studied in low-N and low-C and C- and N-rich culture media by metabolite analysis and 14CO2 determination. In all cases, DCA disappeared within 2 days, and a novel highly polar conjugate termed DCAX accumulated in the growth medium. This metabolite was a dead-end product under C and N enrichment. In oxygenated low-C medium and in much higher yield in oxygenated low-N medium, DCAX was converted to DCA-succinimide and then mineralized. DCAX was purified by high-performance liquid chromatography and identified as N-(3,4-dichlorophenyl)-alpha-ketoglutaryl-delta-amide by high-performance liquid chromatography and mass spectroscopy, gas chromatography and mass spectroscopy, and nuclear magnetic resonance spectroscopy. The formation of conjugate intermediates is proposed to facilitate mineralization because the sensitive amino group of DCA needs protection so that ring cleavage rather than oligomerization can occur.

Aniline Compounds↗
PubMed1998

[Surgical management of anorectal complications in Crohn disease].

Anorectal manifestations can be expected in about 40% of all patients suffering from Crohn's disease. The frequency increases with extension of disease towards the anal canal. If the rectum is involved, they are obligatory present and contribute to the necessity of a stoma formation. Surgical indication is mostly given, especially in cases with putrid secretion. Primary aim of therapy is the control of peri-anorectal infection by excision of all the inflamed extramural tissue. Wether the underlying fistulas are excised too, depends on their topography to the sphincter system. Fistulas, running distal of the midth of the spincter, are radically excisebal and will definitely heal in over 90%. More than 60% of all fistulous anorectal manifestations belong to this type. Rectovaginal fistulas are provided with fistuloplasty, however healing conditions are problematous and healing will only be gained in about 50%. Fistulas in the upper third of the sphincter or above the sphincteric plane (rectal fistula) are managed by seton drainage of the transmural tract and complete excision of the infected tissue around, so that disease is reduced to its most simply condition. The further aim then is to derive it to cicatrous concretisation, so that infection will not expand again and patients will be free of pain. However this needs prolongation of seton drainage for at least 6 to 12 months.

Anal Canal↗
PubMed1998

[Important results of about 45 years balneo-medical research in Bad Hall].

It was tried to show the most essential results of a approximately 45 years' research activity on the field of iodine balneology from the Paracelsus Institute and--since 1993--from the Paracelsus-Gesellschaft Bad Hall. The papers were concerned with: basical studies about the chemistry of the iodine waters, generation of special analytic methods and techniques for iodine determinations and for investigations of the iodine metabolism, generation of new therapeutical iodine applications (for example: eye iontophoresis, electro-aerosol; preparation of the iodine water for a mineral water indoor swimming-bath and for special therapy solutions), investigation of the (favourable) iodine effects on the cardiac and circulation system, on blood rheology, thyroid function, lipid metabolism and on the antioxidant defence mechanisms (with special consequences for arteriosclerosis, diabetes mellitus and cataract), also on visual function and eye diseases (retina, color perception, contrast sensitiveness, cataract, dry eye) and respiratory diseases. Comparative studies on patients and on experimental animals as well as model experiments (e.g. on connective tissue: in vitro studies; tissue cultures) have been used to objectify many empirically observed cure effects. Possible side-effects of a cure with iodine brine (e.g. iodism) were mentioned.

Austria↗
PubMed1997

Radar detection of the nucleus and coma of comet hyakutake

Radar observations of comet Hyakutake (C/1996 B2) made at the Goldstone Deep Space Communications Complex in California have detected echoes from the nucleus and from large grains in the inner coma. The nucleus of this bright comet was estimated to be only 2 to 3 kilometers in diameter. Models of the coma echo indicate backscatter from porous, centimeter-size grains ejected anisotropically at velocities of tens of meters per second. The radar observations suggest that a comet's activity may be a poor indicator of its size and provide evidence that large grains constitute an important component of the mass loss from a typical active comet.

Journal Article↗
PubMed1997

Increased stress parameter synthesis in the yeast Saccharomyces cerevisiae after treatment with 4-hydroxy-2-nonenal.

The metabolism of glutathione (GSH), a marker of oxidative stress and trehalose, a rather general physiological stress marker, was examined in exponentially growing Saccharomyces cerevisiae cells after treatment with 4-hydroxynonenal (HNE). GSH was entirely depleted within a 2 h incubation with 250 microM HNE. After removal of the aldehyde it was replenished by de novo synthesis leading to an overshooting GSH level, which later decreased to the basal level. In addition, trehalose was elevated 4-fold in HNE-treated yeast cells compared to control cells. We conclude that increased GSH levels upon HNE treatment are a general phenomenon of eukaryotic cells to ensure protection and survival during further harsh conditions. Furthermore, we have discovered a new indication for the stress marker trehalose in S. cerevisiae.

Aldehydes↗
PubMed1997

Therapeutic management of grade IV aneurysm patients.

BACKGROUND: The timing of surgery in patients suffering from subarachnoid hemorrhage grade IV and V according to Hunt and Hess, is still controversial. Several authors advocate early surgery for patients in poor clinical condition. Improved outcome and decreased mortality rates were reported. Others exclude patients in poor condition from early aneurysm surgery. METHODS: Forty grade IV aneurysm patients were admitted to our department. After ventriculostomy and cerebral angiography, 28 of them were operated on within 72 hours. The postoperative treatment included hypertensive, hypervolemic, hemodilutional therapy (triple-H therapy) and intensive monitoring (intracerebral pressure, blood pressure, hemodynamic parameters). The mean follow-up time was 6 months. RESULTS: Out of the 28 patients who underwent early surgery, 64% were in good health, 11% in poor health, 25% died; there were no survivors in a vegetative state. Twelve patients were treated conservatively; 50% died from infarction and rebleeding, before the operation was performed. Six underwent delayed aneurysm surgery after clinical improvement. In this group, 25% had good clinical outcome. CONCLUSIONS: Our results favor an aggressive treatment of grade IV aneurysm patients by means of ventricular drainage, early surgery and triple-H therapy.

Critical Care↗
PubMed1997

PCBs and PCDD/Fs in lake sediments of Grosser Arbersee, Bavarian Forest, South Germany.

Despite their environmental importance, there are still relatively few historical studies of the environmental occurrence of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), especially in middle Europe. Trends in PCBs and PCDD/Fs were, therefore, assessed in lake sediments of the Grosser Arbersee over the past 130 years (1860-1990). Ballschmiter-PCB concentrations (congeners # 28, 52, 101, 138, 153, 180) increased between 1946 and 1972 from 4.2 to 32.0 microg kg(-1) dry wt, but have since decreased to 25.6 microg kg(-1) dry wt. High chlorinated PCB congeners reached their maxima earlier (1968-1972) than low chlorinated congeners (1985-1991). These trends were consistent with patterns expected from the production and use of PCBs and their precursors. PCDD/F concentrations increased between 1950 from 0.6 microg kg(-1) dry wt to 2.3 microg kg(-1) dry wt in 1977, falling to 1.7 microg kg(-1) dry wt by 1993. PCDF concentrations exceeded those of PCDD until 1968, but afterwards PCDDs (especially OCDD) were predominant. These patterns suggest that domestic heating and waste combustion were the most likely sources, but pollution from local industries, such as metal smelting and glass production, might also have been involved. The data provide a valuable case study from central Europe which confirms the overall declining trends of PCB and PCDD/F contamination shown elsewhere.

Journal Article↗
PubMed1997

Low-density lipoprotein receptor mRNA in human breast cancer cells: influence by PKC modulators.

It was reported previously that low-density lipoproteins (LDL) differentially stimulate cell growth of hormone-responsive (ER+) and hormone-unresponsive (ER-) mammary tumor cell lines. Here we examined the mRNA levels of the LDL-receptor (LDL-R) gene with RNAse protection analysis in ER- (MDA-MB-231 and HBL-100) and ER+ (MCF-7 and ZR75-1) cells, and compared them with the estrogen receptor (ER) status. Measurable amounts of ER mRNA were only found in ER+ cells as expected. LDL-R mRNA abundance was 3-5 fold higher in ER- cells as compared to ER+ cells. Incubation with phorbol-12-myristate-13-acetate led to a significant increase (p < 0.005) of LDL-R mRNA in ER+ cells, whereas in ER- cells LDL-R mRNA levels remained merely unchanged. Incubation of cells with dioctanoylglycerol, a synthetic homolog of diacylglycerol, increased LDL-R mRNA in ER+ but not in ER-. Inhibition of protein kinase C (PKC) by H7 resulted in a highly significant reduction of LDL-R mRNA both in ER+ and ER- cells. PKC seems to be an important regulator of LDL-R mRNA abundance in mammary tumor cells. It is hypothesized that in human-breast cancer the process of conversion from hormone-responsive to hormone-unresponsive status is accompanied by a change in PKC activity and PKC might exert cell specific differences on the regulation of LDL-R mRNA levels, which in turn influences the delivery of exogenous cholesterol to cancer cells.

Breast Neoplasms↗
PubMed1997

Characterization of the IGF system and analysis of the possible molecular mechanisms leading to IGF-II overexpression in a mesothelioma.

The expression of members of the IGF system in a mesothelioma from a patient suffering from hypoglycemia, in term placenta and HT29 colon adenocarcinoma cells were compared. Very high levels of IGF-II mRNA and protein were detected in the mesothelioma. Moreover, half of the IGF-II protein took the high-molecular-weight form. We also analyzed the parental imprinting status and the promoter usage of the IGF-II gene. Our results showed loss of imprinting (LOI) in the mesothelioma while the imprinting was maintained in HT29 cells, expressing moderate levels of the transcript. Promoter P4 was active in the three tissues we analyzed, whereas IGF-II mRNA transcription from promoter P3 was only detected in the mesothelioma and the placenta, expressing comparably high levels of the transcript. IGF-II gene structure was identical in the analyzed tissues and cells. The type-I receptor mRNA expression was very low in the tumor. IGFBP-2, -4 and -5 mRNAs were detected in the mesothelioma, while IGFBP-2, -3 and -5 transcripts were detected in the placenta. IGFBP-1 and -6 transcripts were not detected.

Aged↗
PubMed1997

[Development of surgery for breast carcinoma by Joseph Rotter].

Hundred years ago Joseph Rotter published his new method of operation for breast cancer, by which the rate of local recurrences significant was decreased. This radical mastectomy performed similarly by Halsted in Baltimore (USA) was the surgical standard of the breast cancer therapy for a long time and is still used in local advanced carcinoma until today.

Breast Neoplasms↗