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W Lutz

Publications and source records attributed to W Lutz.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Tissue polypeptide antigen and carcinoembryonic antigen in bladder neoplasms].

The study was designed to evaluate the effect of acetilation phenotype and smoking on the concentration of tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) in serum of patients with neoplasm of bladder. The study covered a group of 76 patients suffering from neoplasm of bladder and a control group composed of 46 persons. Acetylation phenotype as well as TPA and CEA concentrations in serum were determined. In addition, data on smoking habit were collected. The study indicated significant difference in TPA values in both group while there was no difference in regard to CEA values. It was found that in patients with neoplasm of bladder both acetylation phenotype and smoking affect significantly TPA concentration in serum.

Acetylation↗
PubMed1994

Current radiosurgery practice: results of an ASTRO survey. Task Force on Stereotactic Radiosurgery, American Society for Therapeutic Radiology and Oncology.

PURPOSE: Although there is increasing interest in radiosurgery, little quantitative data regarding current patterns of radiosurgery practice are available. We developed a radiosurgery questionnaire to obtain information on radiosurgery practice. METHODS AND MATERIALS: We distributed the questionnaire to the entire membership of the American Society of Therapeutic Radiology and Oncology in early 1993. Responses were obtained from 74 facilities that practice radiosurgery, corresponding to over 6000 treatments carried out since 1983 by 135 radiation oncologists and 130 physicists. RESULTS: Most respondents were found to work within a multidisciplinary team, consisting of the following specialists (average hours devoted per patient on day of treatment in parentheses): radiation oncologist (3.8), neurosurgeon (3.2), physicist (6.1), radiologist (0.7), nurse (2.7), other (3.0). On average, neurosurgeons and nurses who perform Gamma Knife radiosurgery devote significantly more time-per-patient on the day of treatment than their peers who perform linac radiosurgery. On average, less experienced radiation oncologists and physicists (< or = 24 months experience, or < or = 50 patients treated) devote significantly more time-per-patient on the day of treatment than their more experienced peers. Although there are many more linac radiosurgery facilities than Gamma Knife facilities, on average the number of patients treated per month per facility is significantly larger at the latter. On average, follow-up responsibilities are nearly equally shared by radiation oncologists and neurosurgeons, except at Gamma Knife facilities, where neurosurgeons assume a larger percentage of follow-up responsibility. The percentages of patients treated at linac facilities for metastases or primary CNS malignancy are larger than the corresponding percentages at Gamma Knife facilities; the opposite is true for arteriovenous malformation, acoustic neuroma, and meningioma. CONCLUSION: Current radiosurgery practice usually involves a team approach, with participation of specialists from radiation oncology, neurosurgery, physics, radiology, and nursing. The average number of M.D. and Ph.D. hours required per treatment on the day of radiosurgery is high.

Canada↗
PubMed1994

[The carbohydrate theory].

We can get the full range of our health only if our genome and our environment are compatible. After we had adapted through millions of years to the diet of scavengers and hunters we could not--up to now--adapt to the farming (to the carbohydrates) in a small fraction of this time. The author sees in this the cause of our "Western" diseases. Evidence can be gathered from the rates for cancer and myocardial infarctions in areas where farming came late (Scotland, Scandinavia, Ireland), and from the good results of a return to the (low carbohydrate) Paleolithic diet in many of our civilization diseases. The genetic substratum for this incomplete adaptation to carbohydrates can be seen in the so called gene polymorphism, incomplete genes for ACE etc, which are more frequent in areas where farming came later.

Adaptation, Biological↗
PubMed1994

[N-acetylation polymorphism versus differentiation of organic susceptibility to carcinogenic effect of homo- and heterocyclic aromatic amines].

Smoking and consumption of fried and smoked meat play, besides occupational exposure, a significant role in the etiology of neoplasm induced by chemical carcinogens. Homo- and heterocyclic aromatic amines which are present in tobacco smoke and generate during meat processing are of special concern. Homocyclic aromatic amines are mainly responsible for inducing neoplasm of bladder while heterocyclic amines induce neoplasm of colon. Acetyltransferase is essential in transformation of cells in both groups of aromatic amines. The studies carried out so far indicate that persons displaying low cellular activity of acetyltransferase, so called slow acetylators, are more susceptible to neoplasm of bladder under condition of exposure than those displaying high acetyltransferase activity (fast acetylators). However, under exposure to heterocyclic aromatic amines fast acetylators are more susceptible to neoplasm of colon than slow acetylators. The distinction between fast and slow acetylators as for as susceptibility to neoplasms of bladder and colon is concerned results from different nature of metabolism homo- and heterocyclic aromatic amines undergo in the liver.

Acetyltransferases↗
PubMed1994

[Intracellular receptors of polyaromatic hydrocarbons].

Molecular aspects of the expression of genes responsible for coding the proteins which participate in the oxidative metabolism of polyaromatic hydrocarbons (PAH) have been discussed. Particular attention has been paid to the expression of the gene for the intracellular PAH-binding AHR protein receptor. Possible relationship between genetically-conditioned polymorphism of PAH oxidative metabolism and individual susceptibility to lung cancer has been presented. Methods for assessment of the affinity of AHR protein to PAH which make it possible to assess human susceptibility to carcinogens have been reviewed.

Animals↗
PubMed1993

Vasopressin receptor-mediated endocytosis in cells transfected with V1-type vasopressin receptors.

We examined the process of receptor-mediated endocytosis in A-9 lung fibroblast and chinese hamster ovary (CHO) cells transfected with the recently cloned vasopressin V1a receptor (51). We used a fluorescent labeled vasopressin analog (rhodamine-mercaptopropionic acid lysine vasopressin) and radiolabeled vasopressin to examine this process in the two transfected cell lines. Both A-9 and CHO cells internalize vasopressin in a manner consistent with receptor-mediated endocytosis. A-9 cells internalize vasopressin more rapidly than CHO cells. The process is inhibited by vasopressin and by specific vasopressin V1 receptor antagonists but not by specific V2 receptor antagonists. Hypertonic sucrose inhibits endocytosis in both cell types suggesting a role of clathrin coated pits in the endocytosis of receptor in these cells. These cells are excellent models in which to examine the effect of receptor mutations on vasopressin receptor-mediated endocytosis.

Animals↗
PubMed1993

Hypertonic sucrose treatment enhances second messenger accumulation in vasopressin-sensitive cells.

When we treated vasopressin-sensitive vascular smooth muscle cells (A10 cells) and kidney cells (LLC-PK1 cells) with hypertonic sucrose and vasopressin, we observed a decrease in the internalization of radiolabeled vasopressin into these cells and an increase in the amount of second messenger present in these cells following vasopressin stimulation. In A10 cells exposed to hypertonic sucrose, there was an increase in the amount of cellular inositol phosphates accumulated in response to vasopressin compared with cells not exposed to hypertonic sucrose. Similarly, in hypertonic sucrose-treated LLC-PK1 cells, vasopressin increased the amount of adenosine 3',5'-cyclic monophosphate (cAMP) present within the cells compared with LLC-PK1 cells not exposed to hypertonic sucrose. Hypertonic sucrose treatment inhibited receptor-mediated endocytosis in both these cell lines. Hypertonic sucrose alone did not increase the basal amounts of inositol phosphates or cAMP present in A10 or LLC-PK1 cells, respectively. Hypertonic sucrose treatment inhibits receptor endocytosis and increases second messenger concentrations in vasopressin-sensitive cells.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Population: the dynamics of change.

"This introductory contribution will attempt to give an overview of the demographic analysis of population change under a global perspective and with a long time horizon. Obviously in this context it can only provide some selected highlights which will be grouped around three themes: population growth and the concept of demographic transitions; components of population dynamics; and possible future population trends in major world regions."

Demography↗
PubMed1993

Oncoproteins as biomarkers of a preclinical form of cancer of the respiratory tract induced by environmental carcinogens.

Experimental data and clinical observations indicate that an increased expression of oncogenes or their point mutations play an essential role in the process of carcinogenesis. It was important to find out that environmental and occupational carcinogens activate cellular oncogenes and contribute to increased amounts or occurrence of mutated oncoproteins. The latter are responsible for activating mechanisms which further the neoplastic transformation of cells. The researches are mainly concerned about two oncoproteins: oncoprotein coded by the ras oncogene--called p21 protein and oncoprotein coded by the erbB-2 oncogene--called p185 protein. Investigations performed on neoplastic cells show that the neoplastic transformation process involves not only the afore-said oncogenes and their oncoproteins but also other oncogenes, and that the process itself required activating of more than one oncogene. At present, it is possible to use measurements of oncoproteins in the biological material which is easily available. Due to this fact, a number of works in which measurements of oncoproteins in blood serum were used to assess cancer risk in persons exposed to carcinogens present at the work place, have been published.

Biomarkers, Tumor↗
PubMed1993

[Hormesis and stress responses of human cells to chemical and physical hazards present at work places].

Such a phenomenon when very low doses of harmful chemical or physical agent make the cell "ready" to remain completely indifferent to higher doses of this agent is called hormesis, and factors which evoke this phenomenon--hormetic factors. The majority of hormetic factors are also stress to cells. This suggests that cell mechanisms evoked by hormetic and stress factors are similar. Among occurrence which accompany the cell hormesis and stress, polypeptides called "stress" and "shock" proteins play an important role. Proteins synthesized in conditions of thermal shock, so called proteins of thermal shock (Hsp) are especially well known. Proteins of Hsp70 and Hsp90 families as well as ubiquitin belong to the same group. Proteins of thermal shock are indispensable for protecting cells against a destructive effect of exogenous chemical and physical agents. Understanding of mechanisms associated with cell hormesis and stress is of great importance for occupational medicine. It has been found out that exposure, especially to low doses of harmful factor, does not always produce adverse health effects in an exposed organism.

Biological Factors↗
PubMed1993

Biological markers of early health effects in the assessment of the risk of cancer in people exposed to environmental carcinogens.

Biomarkers of early health effects represent the intermediate stages of the carcinogenesis process, between the initiation and conversion stage and the clinically overt neoplastic disease. The cellular processes indicated by those markers correspond, therefore, to the promotion process. Detection of those cellular processes is extremely important, as the promotion process lasts for many years and bears some signs of being reversible. The promotion process, consisting of a range of consecutive cellular changes involves, among others, activation of proto-oncogens and their transformation into oncogens, and inactivation of the suppressor genes. Therefore, the possibility of observing the trends of those changes by monitoring protein products of the oncogens and suppressor genes in the easily available material (blood, urine) is very useful. Inhibition of intercellular communication seems to play an extremely important role in the complex mechanism of transformation of a normal cell into a neoplastic one. During the carcinogenic process promotion stage, the inhibition is associated with the proteins which form the intercellular junctions and participate in cellular adhesion. That group of proteins includes carcinoembryonal antigen (CEA) and tissue polypeptide antigen (TPA), the tumour antigens which have been known for years. The possible relationship between increased TPA and CEA concentrations is supported not only by the data from the oncology but also by the data from the studies on populations exposed to agents known to increase the risk of neoplastic disease.

Biomarkers, Tumor↗
PubMed1993

[Preliminary studies of the effect of diseases and environmental pollution on the population dynamics of wild rabbits (Oryctolagus cuniculus Linnaeus, 1758) in the federal state of North Rhine-Westphalia (Germany)].

A survey was conducted of wild rabbits (Oryctolagus cuniculus) shot in all districts of the Federal State of North Rhine-Westphalia (Germany). A total of 104 rabbits were examined during 1988 and 1989. Attempts to isolate myxoma virus and other viruses were unsuccessful. Two serum samples neutralised myxoma virus. In 1990, 210 rabbits were examined; 57 animals were subjected to tests for the presence of the virus of viral haemorrhagic disease of rabbits and 42 were tested for specific antibody. No virus was isolated. Antibody titres were judged to be significant in 5% of the rabbits tested. Bacteriological, histological and virological tests showed no evidence of ill health in these animals. With the exception of abnormal cadmium content of tissues, detailed examination of ovaries and testes and lead assays failed to reveal reduced fertility as a reason for the fall in population.

Animals↗
PubMed1992

A vasopressin analog that binds but does not activate V1 or V2 vasopressin receptors is not internalized into cells that express V1 or V2 receptors.

To assess whether receptor binding is sufficient to initiate vasopressin receptor endocytosis in cells expressing the vasopressin V1 or V2 receptors, we synthesized a novel fluorescent-labeled vasopressin analog, [1-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid), 2-(O-ethyl)-D-tyrosine, 4-valine, 8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-CLVP), that binds to vasopressin receptors but does not activate intracellular events such as the mobilization of intracellular calcium or the activation of adenylate cyclase. We compared the manner in which this analog was endocytosed in cells expressing V1 (A-10, rat smooth muscle cells) or V2 (LLC-PK1, porcine kidney cells) receptors with that of a full agonist, [1-(beta-mercaptopropionic acid), 8-lysine-N6-carboxytetramethylrhodamine] vasopressin (R-MLVP) [Lutz et al. (1990) J. Biol. Chem. 265, 4657-4663; Lutz et al. (1990) Proc. Natl. Acad. Sci. U.S.A. 87,6507-6511]. We showed that R-CLVP bound to both types of receptors with good affinity. It failed to increase cyclic AMP concentrations in LLC-PK1 cells and did not increase the mobilization of intracellular calcium in A-10 cells. It bound to the surface of both these cell types in a diffuse manner and it did not undergo receptor endocytosis in either cell type. In contrast, R-MLVP, an agonist that bound to both receptor subtypes and elicited changes in intracellular cyclic AMP and calcium, bound to the surface of these cells in a diffuse manner at early times after exposure, and rapidly underwent endocytosis. We conclude that binding of vasopressin to its receptors alone is insufficient to cause receptor endocytosis, and other events distal to the receptor are required to initiate endocytosis. R-CLVP should be a useful analog in determining the factors responsible for initiating receptor endocytosis.

Amino Acid Sequence↗
PubMed1992

What difference do alternative immigration and integration levels make to Western Europe?

The authors examine the effects of migration and migrant assimilation on population dynamics in Western Europe. "Alternative multi-state population projections to 2050 based on six scenarios show that (1) in the case of no further immigration the total population of Western Europe will start to decline after 2010; (2) the rate of integration influences the future size of the non-European population much more than alternative levels of immigration; (3) in the long run the Eastern Europeans will be quantitatively insignificant; (4) the Western European population is bound to significant population aging no matter what happens with immigration; and (5) in the short to medium run immigrants contribute to the alleviation of the pension burden." (SUMMARY IN FRE)

Acculturation↗