Human renal clear cell carcinoma: Establishment and characterization of a new cell line (G-2101)

Summary A human cell line has been established from a renal adenocarcinoma rib metastasis of a 58-y-old male. This cell line has been maintained in continuous culture for 20 mo. through more than 50 passages. It displays simulataneous expression of the intermediate filaments cytokeratin and vimentin. Flow cytometric analysis of DNA content reveals a major hyperdiploid population. This work was supported in part by a grant from Triton Biosciences, Inc.     

Electrochemical Characteristics of Nitro-Heterocyclic Compounds of Biological Interest: I. The Influence of Solvent

The electrochemical properties of three nitroimidazoles, a nitropyrazole, a nitrofuran and three nitroben-zenoid compounds have been extensively investigated in a range of solvents. The reduction pathway for the nitro group is independent of the cyclic function to which it is attached, but is strongly influenced by the nature of the solvent. In aqueous media, generally, a single, irreversible 4-electron reduction occurs to give the hydroxylamine. In aprotic media (dimethylformamide, methylene chloride or dimethylsulphoxide), a reversible one-electron reduction takes place to form a stable nitro radical anion. At more negative values, a further 3-electron reduction occurs, irreversibly to give the hydroxylamine. In mixed aqueous-organic systems, intermediate behaviour is found, with the reversibility of the RNO₂/RNO₂^- couple increasing with addition of organic medium. The control of the reduction pathway, by changing the electrolytic medium is discussed in relation to the biological activities of the drugs and identification of the short-lived reduction intermediate responsible for DNA damage.     

Homosexual behaviour in wild white-handed gibbons (Hylobates lar)

Homosexual mounting in apes and prosimians is rare. Male-male mounting was observed between an adult male white-handed gibbon and an adolescent male in the same group. The behaviour is discussed in terms of the gibbon group's social structure and the development of the adolescent. It is suggested that this behaviour provides reassurance for the adolescent gibbon.     

Pea lectin is correctly processed,stable and active in leaves of transgenic potato plants

A gene encoding the preproprotein of the pea (Pisum sativum) lectin was expressed in transgenic potato plants using a cauliflower mosaic virus (CaMV) 35S promoter or a tobacco ribulose bisphosphate carboxylase small subunit (ssRubisco) promoter. Presence of the pea lectin to levels greater than 1% of total soluble leaf protein was detected by radioimmunoassay (RIA). The pattern of expression derived from the two promoters was established using both RIA and a squash-blot immunolocalisation technique. Western blotting demonstrated that the preproprotein was correctly processed, generating and subunits that assembled to give an isolectin form observed in pea seeds and roots. It was also found that the haemagglutination activity and specificity of pea lectin synthesised in transgenic potato leaves was comparable to purified lectin from pea cotyledons.     

Relative importance of size versus territorial residency in intraspecific aggression by symbiotic male water mites (Acari: Unionicolidae)

Body size plays an important role in the outcome of aggressive encounters between males of the symbiotic freshwater miteUnionicola formosa. Since intruding males displace resident males as often as resident males successfully defend their territory (mantle cavity of a mussel), resident males do not hold a competitive advantage during male-male aggressive encounters. Larger male size probably enhances a male's success when competing for receptive females.     

Frequencies of chromosomal aberrations induced in human blood lymphocytes by low doses of X-rays

The dose-response for radiation-induced chromosome aberrations in human lymphocytes is usually fitted to the quadratic model. This assumes that the slope is essentially linear at low doses. Empirical observations of linearity at less than 200 mGy are, however, sparse. Some data have been published indicating a non-linear (threshold) response and these are reviewed. In particular one study with X-rays showed a plateau in response up to 50 mGy and with a significant dip below the control level at 4 mGy. The mechanism proposed to explain non-linearity is that low doses stimulate the enzymic repair capability of lymphocytes. Preliminary data are presented from a large experiment by six laboratories in which the low dose-response for X-rays has been re-examined. The plateau in the dose-response relationship, if it exists, does not extend to doses above approximately 10 mGy. No irradiated cells yielded aberration levels significantly below the control. Over the range 0-300 mGy the response can be fitted to a linear regression. There are, however, variations in sensitivity between cells from different donors. An unexpected finding was that some lymphocytes contained greater than 1 exchange aberrations. This may indicate a small subset of cells that are especially susceptible to the induction of aberrations by low doses.     

Isolation and identification of seven metabolites of 25-hydroxydihydrotachysterol3 formed in the isolated perfused rat kidney: a model for the study of side-chain metabolism of vitamin D

The in vivo metabolism of dihydrotachysterol3, an analogue of vitamin D3 and a potent calcemic factor, has been studied in the rat. This in vivo metabolism is compared to the in vitro metabolism of 25-hydroxydihydrotachysterol3 in the perfused rat kidney. Using mass spectrometry and ultraviolet spectroscopy, we have identified seven novel metabolites derived from 25-hydroxydihydrotachysterol3. The seven compounds represent intermediates on two renal pathways (24-oxidation and 26,23-lactone formation) also observed for 25-hydroxyvitamin D3. No evidence was found for the renal synthesis of a 1-hydroxylated metabolite of 25-hydroxydihydrotachysterol3 analogous to the hormone 1,25-dihydroxyvitamin D3. Two of the compounds formed in vitro, 24,25-dihydroxydihydrotachysterol3 and 25-hydroxydihydrotachysterol 26,23-lactone, were also formed in vivo. In vivo studies also revealed the formation of two other unidentified metabolites which are presumed to be formed nonrenally and may be calcemic factors. This work shows that dihydrotachysterol3 metabolism is complex and probably utilizes the same side-chain enzymes as vitamin D3. In addition, our work also confirms that intermediates postulated to lie on pathways to 26,23-lactone in the vitamin D3 series are also formed for the side chain in dihydrotachysterol3.