Dsi-1, a region with frequent proviral insertions in Moloney murine leukemia virus-induced rat thymomas.

Dsi-1 is a region of chromosomal DNA that underwent proviral insertion in 3 of 24 Moloney murine leukemia virus-induced rat thymomas. In one of these tumors, a provirus is also integrated adjacent to the proto-oncogene c-myc. The proviruses in Dsi-1 have been characterized and appear to be complete. The proviruses were located within a 2-kilobase region that contained four prominent DNase I-hypersensitive sites. These hypersensitive sites were observed in Moloney murine leukemia virus-induced thymomas but not in NRK cells. The region of Dsi-1 immediately 3' to the insertions cross-hybridized with human and chicken DNA, indicating that it contains highly conserved sequences. No evidence could be found for the expression of this highly conserved region. Dsi-1 was mapped to mouse chromosome 4. This location demonstrates that Dsi-1 is different from 16 of the known proto-oncogenes (c-abl, c-erbA c-erbB, c-ets-1, c-ets-2, c-fes, c-fos, c-myb, c-myc, c-raf, A-raf, c-Ha-ras, c-Ki-ras, N-ras, c-sis, and c-src) and 12 cellular regions of tumor-associated integrations in retrovirus-induced tumors (c-erbB, Fis-1, int-1, int-2, Mis-1/pvt-1, Mlvi-1, Mlvi-2, c-mos, c-myb, c-myc, Pim-1, and c-Ha-ras). Hybridization experiments indicated that Dsi-1 is probably different from five additional proto-oncogenes (c-fgr, c-fms, c-mos, neu, and c-yes) and from two additional frequent integration regions (lck and Mlvi-3).     

Transport to the cell surface of a peptide sequence attached to the truncated C terminus of an N-terminally anchored integral membrane protein.

Attempts to construct hybrid proteins that are transported to the plasma membrane are frequently unsuccessful because of perturbations in polypeptide folding. In seeking to minimize this problem, we have used the less common type of integral membrane protein, which has an uncleaved signal-anchor domain and an extracellular carboxyl portion, to transport a peptide sequence of interest to the cell surface. A set of plasmids was constructed that contained the gene encoding respiratory syncytial virus glycoprotein G (RSVG) interrupted immediately after one of several proline codons by a synthetic sequence containing unique restriction endonuclease sites and a stop codon. The shortened RSVG gene was flanked by vaccinia virus DNA to permit cloning and expression in a vaccinia virus vector. An open reading frame encoding four copies of the immunodominant repeating epitope of the circumsporozoite protein of Plasmodium falciparum was inserted into the tails of the truncated RSVG genes. Recombinant vaccinia viruses were isolated and shown to express hybrid proteins that reacted with a monoclonal antibody directed to the repeating circumsporozoite epitope. Moreover, immunofluorescence studies indicated that the peptide was on the external cell surface and available to react with antibodies. Expression of the hybrid protein also occurred in rabbits inoculated with the live recombinant vaccinia virus, as demonstrated by the generation of antibodies that bound to P. falciparum sporozoites in vitro.     

Abortion in Canada: religious and ideological dimension's of women's attitudes

This paper examines a number of demographic and sociocultural factors (e.g., age, marital status, family size, religion, religious assiduity, sex-role ideology) as predictors of women's attitudes toward abortion, using data from the Canadian Fertility Survey of 1984. The findings suggest that women's abortion attitudes are to a greater extent based on ideological positions. It appears that anti-abortion stance affects those women who are religious, presumably by increasing the relationship between their general sex-role ideological stances and abortion attitudes. Abortion attitudes also vary according to a woman's education, her size, and province/region of residence.     

Lignans from Piper cubeba

From the hot petrol extract of Piper cubeba ftuits, six lignans were isolated. Two of these, which have been obtained from a natural source for the first time, have been characterized as (2R,3R)-2-(3″,4″,5″-trimethoxybenzyl)-3-(3′,4′-methylenedioxybenzyl)-1,4-butanediol [(?)-dihydroclusin] and (3R,4R)-3,4-bis-(3,4,5-trimethoxybenzyl)tetra-hydro-2-furanol [(?)-cubebinin]. (?)Cubebin, (?)-hinokinin, (?)-clusin and (?)-dihydrocubebin were also found in this plant. Only (?)-cubebin has been reported so far from this source.     

Immobilization of dextranase on bentonite

Dextranase (1,6-α-d-glucan 6-glucanohydrolase, EC 3.2.1.11) from Penicillium aculeatum culture has been immobilized on a bentonite support. The matrix-bound enzyme could be stored as acetone-dried powder or as a suspension in acetate buffer, pH 5.6, for about three weeks at 4°C without any loss of activity. There was no change in the specific activity of the enzyme on immobilization and the enzyme yield was 0.1–0.6 mg/g bentonite matrix. In the presence of sucrose, thermal stability of the immobilized enzyme was high and the bound enzyme could be used for about six cycles.     

Direct fermentation of cassava starch to ethanol by mixed cultures of Endomycopsis fibuligera and Zymomonas mobilis: Synergism and limitations

Summary A mixed culture of Endomycopsis fibuligera NRRL 76 and Zymomonas mobilis ZM4 could directly and more efficiently ferment cassava starch (22.5% w/v) to ethanol (10.5% v/v) than the monocultures. The combination of culture filtrate of E.fibuligera containing amylases and Z.mobilis simultaneously saccharified and fermented the cassava starch to ethanol equally well. Glucoamylase (0.01%) added to the fermenting medium improved ethanol (13.2% v/v) production by the above mixed culture to almost the theoretical level (98%) indicating that this enzyme is a rate-limiting factor in E.fibuligera. Z. mobilis alone converted the enzymehydrolyzed starch only to almost theoretical level (98%).     

Comparison of murine B-cell proliferative response to bacterial lipopolysaccharide and DNP derivative ofMycobacterium tuberculosis antigens

The DNP derivative of sonicate antigens of the H37Ra strain ofMycobacterium tuberculosis (Ra-DNP) is known to induce marked B-cell proliferation. In order to understand whether B-cell proliferation in response to Ra-DNP was antigen driven or represented a non-specific mitogenic effect of Ra-DNP, the effect of Ra-DNP was compared with that of lipopolysaccharide a potent B-cell mitogen. Parameters used for comparison were (i) thymidine incorporation, (ii) viable cell counts, (iii) amount of lg secreted, (iv) isotype profile of Ig released and (v) cell cycling pattern of B-cells in culture. Overall the effect of Ra-DNP was found to be essentially similar to that of lipopolysaccharide for all parameters examined. Yet quantitatively, the effect of the former was always relatively poorer. At optimal doses, the effect of Ra-DNP ranged from 50 to 70% of the lipopolysaccharide effect in different assays. These results suggest that Ra-DNP may have a B-cell mitogenic effect similar to the effect of lipopolysaccharide, but all B-cells may not respond to Ra-DNP.     

Integration of hup Genes into the Genome of Chickpea-Rhizobium Through Site-Specific Recombination

The hup gene fragment of cosmid pHU52 was integrated into the genome of chickpea-Rhizobium Rcd301 via site-specific homologous recombination. Two small fragments of genomic DNA of strain Rcd301 itself were provided to flank cloned hup genes to facilitate the integration. The hup insert DNA of cosmid pHU52 was Isolated as an Intact 30.2 kb fragment using EcoRI, and cloned on partially restricted cosmid clone pSPSm3, which carries a DNA fragment of strain Rcd301 imparting streptomycin resistance. One of the recombinant cosmid clones, pBSL 12 thus obtained was conjugally transferred to the strain Rcd30₁. The integration of hup gene fragment into the genomic DNA through site-specific homologous recombination, was ensured by introducing an incompatible plasmid, pPH1 JI. The integration was confirmed by Southern hybridization. The integrated hup genes were found to express ex plants in two such constructs BSL 12–1 and BSL 12–3.     

Detection and identification of ferricrocin produced by ectendomycorrhizal fungi in the genusWilcoxina

The ectendomycorrhizal fungiWilcoxina mikolae isolates CSY-14 and RMD-947 andW. rehmii isolate CSY-85 were grown in pure culture under iron-limiting conditions. All three isolates tested positive for siderophore formation using both the ferric perchlorate assay and a sensitive HPLC iron-binding assay. A peptide siderophore was isolated from the culture medium by HPLC and shown to contain the amino acids serine, glycine and ornithine in a 1:2:3 ratio. This siderophore was identified as ferricrocin on the basis of electrospray mass spectroscopy and its co-chromatography in two different HPLC systems with ferricrocin isolated fromAspergillus fumigatus. Ferricrocin was the only siderophore isolated from theseWilcoxina cultures. This is the first report of siderophore formation by ectendomycorrhizal fungi.     

Prostaglandin H Synthetase-Mediated Metabolism of Dopamine: Implication for Parkinson's Disease

Abstract: Differences in prostaglandin H synthetase (PHS) activity in the substantia nigra of age- and post-mortem interval-matched parkinsonian, Alzheimer's, and normal control brain tissue were assessed. Prostaglandin E₂ (PGE₂, an index of PHS activity) was higher in substantia nigra of parkinsonian brain tissue than Alzheimer's or control tissue. Incubation of substantia nigra slices with arachidonic acid (AA) increased PGE₂ synthesis. Dopamine stimulated PHS synthesis of PGE₂. [³H]Dopamine was activated by PHS to electrophilic intermediate(s) that covalently bound to DNA, microtubulin protein, bovine serum albumin, and sulfhydryl reagents. When AA was replaced by hydrogen peroxide, PHS/H₂O₂-supported binding proceeded at rates similar to those observed with PHS/AA. Indomethacin and aspirin inhibited AA-mediated cooxidation of dopamine but not H₂O₂-mediated metabolism. PHS-mediated metabolism of dopamine was not affected by monoamine oxidase inhibitors. Substrate requirements and effects of specific inhibitors suggest cooxidation of dopamine is mediated by the hydroperoxidase activity of PHS. ³²P-postlabeling was used to detect dopamine-DNA adducts. PHS/AA activation of dopamine in the presence of DNA resulted in the formation of five dopamine-DNA adducts, i.e., 23, 43, 114, 70, and 270 amol/µg DNA. DNA adduct formation was PHS, AA, and dopamine dependent. PHS catalyzed cooxidation of dopamine in dopaminergic neuronal degeneration is discussed.