Germ-Line Mutations in the von Hippel–Lindau Tumor-Suppressor Gene Are Similar to Somatic von Hippel–Lindau Aberrations in Sporadic Renal Cell Carcinoma

von Hippel–Lindau (VHL) disease is a hereditary tumor syndrome predisposing to multifocal bilateral renal cell carcinomas (RCCs), pheochromocytomas, and pancreatic tumors, as well as angiomas and hemangioblastomas of the CNS. A candidate gene for VHL was recently identified, which led to the isolation of a partial cDNA clone with extended open reading frame, without significant homology to known genes or obvious functional motifs, except for an acidic pentamer repeat domain. To further characterize the functional domains of the VHL gene and assess its involvement in hereditary and nonhereditary tumors, we performed mutation analyses and studied its expression in normal and tumor tissue. We identified germ-line mutations in 39% of VHL disease families. Moreover, 33% of sporadic RCCs and all (6/6) sporadic RCC cell lines analyzed showed mutations within the VHL gene. Both germ-line and somatic mutations included deletions, insertions, splice-site mutations, and missense and nonsense mutations, all of which clustered at the 3' end of the corresponding partial VHL cDNA open reading frame, including an alternatively spliced exon 123 nt in length, suggesting functionally important domains encoded by the VHL gene in this region. Over 180 sporadic tumors of other types have shown no detectable base changes within the presumed coding sequence of the VHL gene to date. We conclude that the gene causing VHL has an important and specific role in the etiology of sporadic RCCs, acts as a recessive tumor-suppressor gene, and appears to encode important functional domains within the 3' end of the known open reading frame.     

1,1-Organoboration of tri-1-alkynyltin compounds: novel triorganotin cations, stannoles, 3-stannolenes and 1-stanna-4-bora-2,5-cyclohexadienes

Tri-1-alkynyltin compounds [R²Sn(CCR¹)₃ (1), R² = Me, R¹ = Me (a), ⁿBu (b), ^tBu (c), Me₃Si (d), 1-(1-cyclohexenyl) (e); R² = Et, R¹ = Me (a(Et)), ⁿBu (b(Et)), ^tBu (c(Et)), SiMe₃ (d(Et)); R² = ⁿBu, R¹ = Me (a(Bu)), ⁿBu (b(Bu))] were prepared, and their reactivity towards trialkylboranes Et₃B (2) and ⁱPr₃B (3) in 1,1-organoboration reactions was studied. The first step in each reaction is an intermolecular 1,1-alkytoboration. Afterwards, intramolecular 1,1-vinyloboration or 1,1-alkyloboration compete with further intermolecular 1,1-alkyloboration. Various triorganotin cations (4-7), stabilized by intramolecular side-on coordination to the CC bond of an alkynylborate moiety, were detected as highly fluxional intermediates prior to rearrangement into heterocyclic systems such as stannoles (9-11), 1-stanna-4-bora-2, 5-cyclohexadienes (8, 12). The reactions between 1a or 1a(Bu) and an excess of Et₃B (2) afford the tris(alkenyl)tin compounds 13 via threefold intermolecular 1, 1-ethyloboration. 13 rearrange to the 3-stannolenes (14a or 14a(Bu)). The intermediates and final products were characterized by multinuclear one- and two-dimensional ¹H, ¹¹B, ¹³C, ²⁹Si and ¹¹⁹Sn NMR.     

Determination of platinum by neutron activation analysis in nerve tissue from rats treated with cisplatin

Biological Trace Element Research - The analytical method used for the determination of traces of platinum and gold in different tissues of Wistar rats is based on neutron activation analysis with...     

Carbon allocation in developing spruce needles. Enzymes and intermediates of sucrose metabolism

In lyophilized needles of Norway spruce ( Picea abies [L.] Karsten) and starting from bud break, we determined enzyme activities (sucrose phosphate synthase [SPS; EC 2.4,1.14]. sucrose synthase [SS; EC 2.4,1.13]. acid invertase [AI; EC 3.2,1.26]) and intermediates (starch, sucrose, glucose, fructose; fructose 6-phosphate, fructose 2.6-bisphosphate [F26BP]) of carbohydrate metabolism together with needle weight, shoot length, chlorophyll and protein. For up to 110 days after bud break, samples were taken twice a week from about 25-year-old trees under field conditions. At least three periods can be distinguished during needle maturation. During the first period (up to 45 days after bud break) Al showed the highest extractable activity. This coincided with very high levels of F26BP (up to 11 pmol [mg dry weight]⁻¹) and a transient increase of starch in parallel to a decrease of sucrose. The interval between 45 and 70 days after bud break was characterized by high SS activity (ratio of fructose/glucose >1), much decreased levels of F26BP (down to below 1 pmol [mg dry weight]⁻¹), and a pronounced increase in the dry weight/fresh weight ratio. In parallel, starch declined and soluble carbohydrates increased. Finally, needle maturation was characterized by decreasing SS and continuously increasing SPS activities, so that the ratio of SPS/SS increased more than 6-fold. AI. however, did not decline with maturation. Changes in pool sizes of metabolites and enzyme activities (AI. SPS) are consistent with current concepts on sink/source transition. SS is obviously important with regard to the synthesis of structural polysaccharides.     

Technique for isolating plasmids from exopolysaccharide producing Lactobacillus spp.

Summary A large scale plasmid isolation technique is described for the isolation of plasmids from exopolysaccharide producing strains of Lactobacillus spp. Plasmids of 1.9 to 56 kb were isolated which were pure enough to be used for restriction analysis and cloning experiments.     

Cloning and expression analysis of an ADP-ribosylation factor from Solanum tuberosum L.

Summary A cDNA clone encoding an ADP-ribosylation factor from potato (Solanum tuberosum L.) was isolated. The nucleotide and deduced amino acid sequences show high homology to known ADP-ribosylation factor sequences from Arabidopsis, yeast, cow and man. In northern blot experiments, all tissues analysed showed expression of the corresponding mRNA. Strongest expression was found, however, in potato tubers.Abbreviations ARF, ADP ribosylation factor - BSA bovine serum albumin - EDTA ethylenediaminetetraacetic acid - SDS sodium dodecyl sulfate - SSC sodium saline citrate     

Synergism of Trichoderma reesei cellulases while degrading different celluloses

Summary The synergistic action of purified cellulases from Trichoderma reesei in hydrolysis of cellulose decreased with increasing substrate concentration, depended strongly on the the type of cellulose used, and was maximal on crystalline cellulose. Contrarily, the activity of the individual cellulases was highest on amorphous cellulose. The binary combinations CBH I/EG III and CBH I/CBH II exhibited the greatest degree of synergism on crystalline cellulose.     

A complex experimental assessment for objective description of hierarchical psychophysiological behavior as human regulatory phenotype

For the objective and valid identification of different human regulatory phenotypes it should be useful to analyze the behavior of different regulatory subsystems (Anochin 1976) in one multivariate design. Therefore in a DARA supported project a fully computerized and reliable laboratory assessment was developed and tested. We used a set of electrophysiological parameters that should indicate the activity of different functional regulation systems on different "behavioral levels". Skin conductance, skin temperature and voice pitch were used as indicators of sympathico-parasympathical activity. Breathing, heart rate variability and bloodpressure should indicate cardiovascular activity and electromyogram and mimic variablity were thought as indicators of locomotional external behavioral activity. To identify physiological reactions which are influenced by emotional stress we used voice stress measures. Even in the field of aviation and space medicine there exist data about the correlation of voice pitch with emotional excitation (Hecker et. al. 1968, Williams et.al. 1969, Friedrich, Vaic 1978, Vaic et.al. 1981,1982, Griffin, Williams 1987). In our former study (MOSAIC-study, Johannes 1990) the voice pitch and its variation range correlated with perceived emotional excitation but were independent of real bloodpressure variations. Two different types of pitch reaction to this experimental design were correlated to psychological personality scales and assigned subjects to "sensitizers" and "suppressors".