[Occupational and non-occupational risk factors in bladder cancer patients in an industrialized area located in former East-Germany]. / Berufliche und ausserberufliche Risikofaktoren für das Harnblasenkarzinom in einem ehemaligen Industriegebiet der neuen Bundesländer.

PURPOSE: Several occupational carcinogens are metabolized by polymorphic enzymes. The distribution of the polymorphic enzymes N-acetyltransferase 2 (NAT2; substrates: aromatic amines), glutathione S-transferase M1 (GSTM1; substrates: e. g., reactive metabolites of polycyclic aromatic hydrocarbons), and glutathione S-transferase T1 (GSTT1; substrates: small molecules with 1 - 2 carbon atoms) were investigated. MATERIAL AND METHODS: At the urological department in Lutherstadt Wittenberg, 136 patients with a histologically proven transitional cell cancer of the urinary bladder were investigated for all occupations performed for more than 6 months. Several occupational and non-occupational risk factors were asked. The genotypes of NAT2, GSTM1, and GSTT1 were determined from leucocyte DNA by PCR. RESULTS: Compared to the general population in Middle Europe, the percentage of GSTT1 negative persons (22.1 %) was ordinary; the percentage of slow acetylators (59.6 %) was in the upper normal range, while the percentage of GSTM1 negative persons (58.8 %) was elevated in the entire group. Shifts in the distribution of the genotypes were observed in subgroups who had been exposed to asbestos (6/6 GSTM1 negative, 5/6 slow acetylators), rubber manufacturing (8/10 GSTM1 negative), and chlorinated solvents (9/15 GSTM1 negative). CONCLUSIONS: The overrepresentation of GSTM1 negative bladder cancer patients also in this industrialized area and more pronounced in several occupationally exposed subgroups points to an impact of the GSTM1 negative genotype in bladder carcinogenesis.

Polyvinyl alcohol particle size and suspension characteristics.

PURPOSE: To evaluate the size and shape of commercially available polyvinyl alcohol (PVA) particles and to determine whether they change in size when suspended in nonionic contrast and in a solution of nonionic contrast and absolute alcohol. METHODS: The two-dimensional area and the long and short axis of PVA particles from several different vendors were measured using a light microscope attached to a video system and an image-processing software program. Particles were measured as packaged (dry or suspended in saline), suspended in ioversol, and suspended in ioversol containing 30% alcohol. RESULTS: All brands of dry particles had similar microscopic appearances. The saline-suspended particles had fewer and finer perforations. After suspension in contrast, all sizes and brands of dry particles significantly increased in size. The particles packaged in saline did not expand. The addition of alcohol to the contrast did not consistently change particle size. Particle aggregation was similar in both contrast suspensions for all groups of particles. Particles less than 50 microns in size were rarely observed in any PVA preparation after suspension. CONCLUSIONS: The three dry PVA preparations seem to be similar. All increase significantly in size when suspended in nonionic contrast or contrast-alcohol solutions. The saline-packaged PVA particles were different from the dry variety and did not enlarge in contrast or contrast-alcohol solutions. Alcohol did not change the size or suspension characteristics of PVA particles. Particles less than 50 microns in size were rarely identified.

Stereoselective metabolism of the monoterpene carvone by rat and human liver microsomes.

The large amounts of carvone enantiomers consumed as food additives and in dental formulations justifies the evaluation of their biotransformation pathway. The in-vitro metabolism of R-(-)- and S-(+)-carvone was studied in rat and human liver microsomes using chiral gas chromatography. Stereoselective biotransformation was observed when each enantiomer was incubated separately with liver microsomes. 4R, 6S-(-)-Carveol was NADPH-dependently formed from R-(-)-carvone, whereas 4S, 6S-(+)-carveol was produced from S-(+)-carvone. Metabolite formation followed Michaelis-Menten kinetics exhibiting a significant lower apparent Km (Michaelis-Menten Constant) for 4R, 6S-(-)-carveol compared with 4S, 6S-(+)-carveol in rat and human liver microsomes (28.4+/-10.6 microM and 69.4+/-10.3 microM vs 33.6+/-8-55 microM and 98.3+/-22.4 microM). The maximal formation rate (Vmax) determined in the same microsomal preparations yielded 30.2+/-5.0 and 32.3+/-3.9 pmol (mg protein)(-1) min(-1) in rat liver and 55.3+/-5.7 and 65.2+/-4.3 pmol (mg protein)(-1) min(-1) in human liver microsomes. Phase II conjugation of the carveol isomers by rat and human liver microsomes in the presence of UDPGA (uridine S'-diphosphogluaronic acid) only revealed glucuronidation of 4R, 6S-(-)-carveol. Vmax for glucuronide formation was more than 4-fold higher in the rat liver compared with human liver preparations (185.9+/-34.5 and 42.6+/-7.1 pmol (mg protein)(-1) min(-1), respectively). Km values, however, showed no species-related difference (13.9+/-4.1 microM and 10.2+/-2.2 microM). This study demonstrated stereoselectivity in phase-I and phase-II metabolism for R-(-)- and S-(+)-carvone and might be predictive for carvone biotransformation in man.

Computed tomography-anatomy of the normal feline nasolacrimal drainage system.

Computed tomography (CT) of the nasolacrimal drainage system with and without contrast medium (barium sulfate) was used to create an anatomic basis for clinical evaluation in domestic cats. To evaluate and compare the anatomical findings, three casts were carried out and were followed by CT examinations. These CT series were also used for a three-dimensional (3D) reconstruction of the nasolacrimal drainage system within surrounding structures. In noncontrast CT images, osseous structures limiting the nasolacrimal drainage system are easily recognizable. In most cats, this allows the identification of the nasolacrimal drainage system even without contrast enhancement. A distal part of the lacrimal sac adjoins directly to the respiratory mucosa of the nasal cavity without an osseous protection. Thus, this may represent a predilection site for infiltration of adjacent pathologic processes from the nasal cavity onto the lacrimal sac. The nasolacrimal duct begins on level with the maxillary third premolar tooth. The apex of the root of the canine tooth is situated very close to the nasolacrimal duct. This close topographic relation may lead to problems with the nasolacrimal drainage system. In domestic cats the nasolacrimal drainage system consists of a descending and a horizontal part, which form an angle of approximately 90 degrees for unhindered drainage of the lacrimal fluid.

Measurement of hydraulic conductivity in isolated arterioles of rat brain cortex.

We have developed a new method for quantification of arteriolar hydraulic conductivity (Lp) from isolated rat brain vessels. The volume flux of water per unit surface area across the arteriole wall (Jv/S) was assessed from measurements of silicon oil drop movement within an occluded vessel at two to three pressures (between 20 and 70 mmHg); the Lp was derived from the slope of the relationship between Jv/S and applied pressure. Lp was measured in isolated cerebral arterioles 1) at room temperature (22 degrees C) without spontaneous vessel tone (control Lp; n = 11), 2) at room temperature with 10(-4) M adenosine (n = 5), and 3) at 37 degrees C with vessels dilated submaximally with 10(-4) M adenosine (n = 6). Lp at 22 degrees C without adenosine was 13.2 +/- 4.2 x 10(-9) (+/- SE) cm.s-1.cmH2O-1 for all vessels studied. Lp values ranged from 1.2 to 44.1 x 10(-9) cm.s-1.cmH2O-1 with a median value that was 5.9 x 10(-9) cm.s-1.cmH2O-1. Lp increased significantly (on average, 2.6-fold) with adenosine at 37 degrees C but not with adenosine at 22 degrees C. Control Lp bore no relationship to either the development of spontaneous tone or the diameter response to pH change, two recognized indicators of vessel viability.

Sclerotherapy of a bleeding duodenal varix.

A case of successful treatment of a bleeding duodenal varix in a patient with portal hypertension and compensated cryptogenic cirrhosis (Child A) is reported. The 42-year-old man had a history of recurrent gastrointestinal hemorrhage over 14 years. In 1966 he underwent a portocaval shunt operation. Angiography in 1968 revealed a thrombosis of the shunt as well as of the splenic vein. Splenectomy was performed because of hypersplenism. In 1980 bleeding from esophageal varices occurred and was treated by sclerotherapy. Seven weeks after sclerotherapy massive bleeding from a duodenal varix occurred. Sclerotherapy of the duodenal varix via a flexible endoscope proved successful. Since then, during a follow-up period of 15 months, the patient has had no further bleeding episodes.

Characterization of the ZAT1p zinc transporter from Arabidopsis thaliana in microbial model organisms and reconstituted proteoliposomes.

The ZAT1p zinc transporter from Arabidopsis thaliana (L.) Heynh. is a member of the cation diffusion facilitator (CDF) protein family. When heterologously expressed in Escherichia coli, ZAT1p bound zinc in a metal blot. Binding of zinc occurred mainly to the hydrophilic amino acid region from H182 to H232. A ZAT1p/ZAT1p*Delta(M1-I25) protein mixture was purified and reconstituted into proteoliposomes. Uptake of zinc into the proteoliposomes did not require a proton gradient across the liposomal membrane. ZAT1p did not transport cobalt, and transported cadmium at only 1% of the zinc transport rate. ZAT1p functioned as an uptake system for 65Zn2+ in two strains of the Gram-negative bacterium Ralstonia metallidurans, which were different in their content of zinc-efflux systems. The ZAT1 gene did not rescue increased zinc sensitivity of a Delta ZRC1single-mutant strain or of a Delta ZRC1 Delta COT1 double-mutant strain of Saccharomyces cerevisiae, but ZAT1 complemented this phenotype in a Delta SpZRC1 mutant strain of Schizosaccharomyces pombe.

Characterization of the 101-kilobase-pair megaplasmid pKB1, isolated from the rubber-degrading bacterium Gordonia westfalica Kb1.

The complete sequence of the circular 101,016-bp megaplasmid pKB1 from the cis-1,4-polyisoprene-degrading bacterium Gordonia westfalica Kb1, which represents the first described extrachromosomal DNA of a member of this genus, was determined. Plasmid pKB1 harbors 105 open reading frames. The predicted products of 46 of these are significantly related to proteins of known function. Plasmid pKB1 is organized into three functional regions that are flanked by insertion sequence (IS) elements: (i) a replication and putative partitioning region, (ii) a putative metabolic region, and (iii) a large putative conjugative transfer region, which is interrupted by an additional IS element. Southern hybridization experiments revealed the presence of another copy of this conjugational transfer region on the bacterial chromosome. The origin of replication (oriV) of pKB1 was identified and used for construction of Escherichia coli-Gordonia shuttle vectors, which was also suitable for several other Gordonia species and related genera. The metabolic region included the heavy-metal resistance gene cadA, encoding a P-type ATPase. Expression of cadA in E. coli mediated resistance to cadmium, but not to zinc, and decreased the cellular content of cadmium in this host. When G. westfalica strain Kb1 was cured of plasmid pKB1, the resulting derivative strains exhibited slightly decreased cadmium resistance. Furthermore, they had lost the ability to use isoprene rubber as a sole source of carbon and energy, suggesting that genes essential for rubber degradation are encoded by pKB1.

Camelysin is a novel surface metalloproteinase from Bacillus cereus.

Bacillus cereus frequently causes food poisoning or nosocomial diseases. Vegetative cells express the novel surface metalloproteinase camelysin (casein-cleaving metalloproteinase) during exponential growth on complex, peptide-rich media. Camelysin is strongly bound to the cell surface and can be solubilized only by detergents or butanol. Camelysin spontaneously migrates from the surface of intact bacterial cells to preformed liposomes. The complete sequence of the camelysin-encoding gene, calY, was determined by reverse PCR on the basis of the N-terminal sequence and some internal tryptic cleavage peptides. The calY gene codes for a polypeptide of 21.569 kDa with a putative signal peptide of 27 amino acids (2.513 kDa) preceding the mature protein (19.056 kDa). Although the predicted amino acid sequence of CalY does not exhibit a typical metalloprotease consensus sequence, high-pressure liquid chromatography-purified camelysin contains one zinc ion per protein molecule. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and tryptic peptide mass fingerprinting confirmed the identity of this zinc-binding protein as CalY. Disruption of the calY gene results in a strong decrease in the cell-bound proteolytic activity on various substrates.