Transformations of acetates of citronellol,geraniol, and linalool by Aspergillus niger: regiospecific hydroxylation of citronellol by a cell-free system

Summary Incubation of acetates of geraniol, citronellol and linalool with Aspergillus niger resulted in their hydrolysis to corresponding alcohols which were further hydroxylated to their respective 8-hydroxy derivatives. In the case of linalyl acetate, besides linalool and 8-hydroxylinalool, small amounts of geraniol and -terpineol were also formed. Microsomes (105 000xg sediment) prepared from induced cells of A. niger were found to convert (1-³H)citronellol to 8-hydroxy citronellol in the presence of NADPH and O₂. The pH optimum for the hydroxylase was found to be 7.6.     

Aggravation of cholesterol induced hyperlipidemia by chronic vitamin C deficiency: experimental study in guinea pigs

Chronic vitamin C deficiency was induced in guinea pigs by restricting their vitamin C intake to 0.5 mg daily. This was just sufficient to prevent rapidly fatal scurvy and 55 per cent of the animals survived. In 16 weeks their serum ascorbic acid (SAA) fell to 0.16 +/- 0.06 mg/dl as compared to 0.73 +/- 0.11 in control animals receiving 5 mg vitamin C daily. There was a marked increase in serum cholesterol, LDL-cholesterol, VLDL-cholesterol, triglycerides and total lipids. HDL-cholesterol was, however, decreased resulting in a shift of the LDL/HDL ratio from 1.13 +/- 0.16 in the control to 5.91 +/- 1.70 in the low vitamin C group. Cholesterol feeding (100 mg/day) by itself lowered the SAA significantly, besides producing hyperlipidemia. When the vitamin C intake was reduced to only 0.5 mg/day, the effects of cholesterol feeding were exaggerated; the magnitude of hyperlipidemia was now significantly greater than with simple cholesterol feeding. The LDL/HDL ratio rose to 19.02 +/- 3.32 from 1.13 +/- 0.16 in the normal guinea pigs. Chronic vitamin C deficiency seems to affect the blood lipid profile unfavourably which could promote atherogenesis.     

Effect of Maternal Alcohol Consumption on the Lipid Composition of CNS in the Offspring

Maternal alcohol consumption at a level that does not affect calorie intake increases cholesterol concentration and content as well as incorporation of labeled glucose into cholesterol in the brain and spinal cord of newborn rat pups. Continued consumption of alcohol during lactation also affects the galactolipid concentration in the brain and spinal cord of pups at 21 days of age, and this increase seems mainly to be due to an increase in content of myelin lipids. Analysis of myelin shows that the concentration of phospholipids also increases in this fraction. The increase in incorporation of labeled glucose into these membrane lipids suggests an increase in the synthesis of these lipids, which prevents fluidization of the membrane by alcohol. That in the brainstem the increase in levels of cholesterol and galactolipids is higher than in other regions and that there is also an increase in content of sphingomyelin, phosphatidylcholine, and phosphatidylethanolamine suggest that the brainstem needs better protection against fluidization.     

Sister-chromatid exchanges induced by triethylenemelamine: in vivo and in vivo/in vitro studies in mouse and Chinese hamster bone marrow and spleen cells

This study was designed to obtain sister-chromatid exchange (SCE) frequencies in bone marrow and spleen cells of mice and Chinese hamsters under in vivo and in vivo/in vitro systems following treatment of animals with varying doses (15-405 micrograms/kg) of triethylenemelamine (TEM). A dose-related SCE response was found in both species, tissues, and systems analyzed following TEM treatment. In vivo, similar responses were noted for both tissues in both species. However, in vivo/in vitro, the response was lower than in vivo and it varied with the tissue. The spleen cells were more sensitive and gave higher numbers of SCEs than bone marrow of both species at the two highest doses tested (135 and 405 micrograms/kg). These differences may be attributed to cell-culturing effects, type of cells analyzed, species and tissue specificities, and pharmacokinetic properties of the chemical. This study lends support to recently established in vivo/in vitro cell culture methodologies employing mice and Chinese hamsters for comparative cytogenetic analysis.     

Yolk proteins from nematodes, chickens, and frogs bind strongly and preferentially to left-handed Z-DNA

Yolk proteins purified from the nematode Caenorhabditis elegans, from the frog Xenopus laevis, and from chicken eggs all have the unexpected property of binding strongly and preferentially to a left-handed Z-DNA probe, brominated poly(dG-dC). We estimate that the nematode proteins bind to Z-DNA with an association constant of at least 10(4) (M-1) and that this association constant is at least 40-50-fold higher than the association constant to B-DNA. Thus, yolk proteins have a higher Z-DNA specificity than most of the Z-DNA binding proteins previously isolated from other sources. Although yolk protein binding to Z-DNA is poorly competed by a wide variety of nucleic acids, the interaction is strongly competed by the phospholipids cardiolipin and phosphatidic acid (500-1000-fold better than by the same mass of B-DNA). We suggest that Z-DNA interacts with the yolk protein phospholipid binding site. In general, our results emphasize the danger of using physical properties to infer biological function. In particular, our results should raise serious questions about the biological relevance of previously isolated Z-DNA binding proteins.     

A new case of Robertsonian translocation in cattle

A new Robertsonian translocation was found in several animals of the Blonde d'Aquitaine breed. The fused chromosome analyzed by G- and R-banding results from the fusion of chromosomes 21 and 27. C-banding suggests that the fused chromosome is dicentric.     

X-linkage of malic enzyme in Anopheles culicifacies species B

A survey for malic enzyme (Me) in laboratory strains of species A and species B of Anopheles culicifacies had uncovered two electrophoretic variants, slow and fast, in two strains of species B. Genetic analysis revealed the two variants to be codominant alleles segregating at a locus, Me, which is sex linked. Because of the XX-XY sex determining mechanism, in F1 females, two electromorphs, viz., slow and fast, were observed, whereas in males only one electromorph of maternal origin was seen. Linkage experiments with another X-linked mutant, white eye (w), indicated the map distance between the two loci to be 9.52 +/- 0.86.     

Active human tissue plasminogen activator secreted from insect cells using a baculovirus vector

A baculovirus expression vector was constructed with the tissue plasminogen activator (TPA) cDNA under the control of the viral polyhedrin promoter. After infection of insect cells with the recombinant baculovirus, active TPA was secreted into the medium in which these cells were grown. TPA was isolated from the conditioned media using metal chelate affinity chromatography followed by immunoaffinity purification using mouse monoclonal anti-human TPA coupled to Sepharose. Sodium dodecyl sulfate-gel electrophoresis under reducing conditions and sequence analysis of recombinant human TPA have revealed a two-chain form of the enzyme. The N-terminal amino acid was identified to be serine, indicating that it was processed at its N-terminus by the insect cell culture in a manner similar to that observed for mammalian cells. The relative specific activity of recombinant TPA from insect cells is comparable to that of Bowes melanoma TPA standard. Its activity is stimulated in the presence of fibrinogen fragments, but by a factor about 2.3-fold lower than the Bowes melanoma TPA. The apparent molecular weight of recombinant TPA from insect cells was about 60K by fibrin agar activity gels, suggesting less complex glycosylation than recombinant TPA from mammalian cells.     

Distribution of FMRFamide-like immunoreactivity in the forebrain of the catfish, Clarias batrachus (Linn.).

The anatomical distribution of FMRFamide-like immunoreactivity in the forebrain and pituitary of the catfish, Clarias batrachus, was investigated. Immunoreactive cells were observed in the ganglion cells of the nervus terminalis (NT) and in the medial olfactory tracts. In the preoptic area, FMRFamide-containing perikarya were restricted to the lateral preoptic area, paraventricular subdivision of the nucleus preopticus, nucleus suprachiasmaticus and nucleus preopticus periventricularis posterior. In the postoptic area, some cells of the nucleus postopticus lateralis and nucleus of the horizontal commissure showed moderate immunoreactivity. In the tuberal area, immunoreactivity was observed in few cells of the nucleus hypothalamicus ventralis and nucleus arcuatus hypothalamicus (NAH). Nucleus ventromedialis thalami was the only thalamic nucleus with FMRFamide immunoreactivity. Immunoreactive processes were traceable from the NT through the medial as well as lateral olfactory tracts into the telencephalon and the area ventralis telencephali pars supracommissuralis (Vs). Further caudally, the immunoreactive fibers could be traced into discrete areas, including habenular and posterior commissures, neurohypophysis and pituitary; isolated fibers were also observed in the pineal stalk. A loose network of immunoreactive processes was observed in the olfactory bulbs and the entire telencephalon, with higher densities in some areas, including Vs. A dense plexus of immunoreactive fibers was seen in the pre- and postoptic areas and around the paraventricular organ, while relatively few were observed in the thalamus. A high concentration of fiber terminals was found in the caudal tuberal area.