Guaianolides from Saussurea affinis

Cynaropicrin, 11βH-11,13-dihydrodesacylcynaropicrin, aguerins A and B, isoamberboin and the new guaianolides saussureolide and 11βH-11,13-dihydrodesacylcynaropicrin 8-β-d-glucoside were isolated from Saussurea affinis.     

The α promoter regulator-ovalbumin chimeric gene resident in human cells is regulated like the authentic α 4 gene after infection with herpes simplex virus 1 mutants in α 4 gene

Human TK^? 143 cells were converted to TK⁺ phenotype with a plasmid containing the native herpes simplex virus 1 (HSV-1), thymidine kinase, a β gene, and a chimeric ovalbumin gene consisting of the coding sequences of the ovalbumin gene linked to the promoter-regulatory region of the HSV-1 α 4 gene. Comparison of the synthesis of ovalbumin and the α 4 gene product in the converted cells infected with ts mutants in α 4 gene and incubated at the permissive (33°C) and nonpermissive (39°C) temperatures revealed the following. (i) The synthesis of both ovalbumin and α 4 gene product was transiently induced at the permissive temperature but continued at elevated levels for many hours at the nonpermissive temperature. (ii) The synthesis of both ovalbumin and α 4 gene products resumed when the infected cells were shifted from permissive to nonpermissive temperature after the shut-off of α protein synthesis. (iii) Although both the β-TK and α 4-ovalbumin chimeric genes were covalently linked on the same plasmid, each was regulated independently. We conclude that α gene regulation is determined solely by (a) the inducer and (b) the induction sequence contained in the promoter-regulatory region and not by the location or the higher order structure of the immediate environment of the gene.     

Altered aggregational properties in a genetic variant of human glucose 6-phosphate dehydrogenase

The Tel Hashomer variant of human G6PD migrates as two prominent components during electrophoresis in several gel systems in which red cell G6PD from other males migrates predominantly as a single band. Since human males normally have but one X-chromosome, the extra band of this variant seemed an exception to earlier biochemical and genetic observations suggesting that human red cell G6PD is determined by a locus on the X chromosome. Results of the present studies indicate that the Tel Hashomer variant is unusually susceptible to the formation of a complex which has a higher molecular weight than normal G6PD and which represents the slow electrophoretic component. The conditions of formation and disruption of this complex in crude and purified Tel Hashomer preparations suggest that it results from the formation of disulfide bridges between molecules of Tel Hashomer G6PD.Supported by U.S. Public Health Service Research Grants AM-11065 and FR-5406 and Research Career Development Award 5 K3 AM 7992.     

Serum-dependent depression of alkaline phosphatase in HeLa cells

Reduction in alkaline phosphatase activity was observed when HeLa S3 cells were grown in Puck's medium containing high concentrations of human serum. This effect was not seen with the enzyme of Chang liver 8A cells. The induction of increased alkaline phosphatase in HeLa S3 by prednisolone or by osmolality changes was not prevented by serum. The concentration of serum in the culture medium had no influence on acid phosphatase activity.     

Intracerebral distribution pattern of radioactive morphine and morphine-like drugs after intraventricular and intrathecal injection

Summary The intracerebral distribution patterns of ¹⁴C-morphine, ³H-dihydromorphine, and ³H-fentanyl after intraventricular injection were studied autoradiographically in rats and rabbits. The extent of permeation into the ventricular wall was measured at different times after injection. The hydrophilic morphine and dihydromorphine could be demonstrated within the tissue up to 4 hours. They seemed to be retained within the gray matter and hindered in crossing fiber bundles. On the other hand, the lipophilic fentanyl was quickly removed from the brain but remained relatively longer demonstrable within the white matter. Also, after intrathecal injection of ¹⁴C-morphine a time dependent spread from the injection site was observed. The use of autoradiography in pharmacological experiments as described was found advantageous. Thus, it is possible to correlate directly, the time course of the pharmacological effect and the respective distribution pattern of the drug applied. This may lead to better information about the probable sites of drug action.     

Fractionation of native and denatured transforming deoxyribonucleic acid from Bacillus subtilis

1. Native DNA from Bacillus subtilis was fractionated by stepwise elution from methylated albumin, the transforming activity being confined to two out of four fractions. Partial separation of DNA active in transformation for the arginine marker from that showing activity for the histidine and tryptophan markers was achieved. 2. Partial denaturation of DNA at 90 degrees and 93.5 degrees resulted in the preferential destruction of transforming activity for the histidine and tryptophan markers. 3. Denaturation of DNA at 100 degrees followed by chromatography on methylated albumin yielded five fractions, two of which exhibited residual activity. Redenaturation at 100 degrees resulted in the interconversion of four out of the five fractions. Redenaturation of fractions labelled with (15)N and (2)H suggested the presence of a specific component that did not readily take part in the interconversions.     

Opioid Receptors of Neuroblastoma Cells Are in Two Domains of the Plasma Membrane that Differ in Content of G Proteins

Opioid receptors of NG 108-15 cell membranes are distributed in two membrane fractions sedimenting at 20,000 g (P2) and 200,000 g(P3). The number of receptors is identical in P2 and P3, but in P2 all sites are present in one high-affinity state (2 nM), whereas in P3 60% of these receptors display lower affinity (150 nM). Upon addition of GTP or pretreatment with pertussis toxin, 80% of the sites exist in low affinity in both P2 and P3. Therefore, the effect of GTP and pertussis toxin on agonist binding appears to be smaller in P2 than in P3. In contrast, sodium inhibits agonist binding in P2 and P3 to the same extent and with identical potency. Opioid-mediated stimulation of GTPase is much greater in P2 than in P3, whereas inhibition of adenylate cyclase does not differ in the two fractions. Using site-specific antibodies and pertussis toxin-catalyzed ADP-ribosylation, we found that the amount of G proteins in P3 is only 30-50% of that in P2. Treatment of intact cells with the hydrophilic protein-modifying agent sulfosuccinimido-biotin results in biotinylation of proteins from both fractions and in a similar reduction of opioid binding in P2 and P3. Likewise, exposure of intact cells to the alkylating opioid antagonist, chlornaltrexamine, produces identical degrees of receptor inactivation in P2 and P3. The rate of in vivo pertussis toxin-mediated modification of G proteins is not different in the two fractions.(ABSTRACT TRUNCATED AT 250 WORDS)