Studies on tissue cultures of the genus Cinchona L. alkaloid production in cell suspension cultures

Initiation and culture of callus and cell suspensions of Cinchona ledgeriana and C. succirubra as well as the successful isolation and selection of a high-yielding alkaloid-forming strain derived from the leaf rachis of a C. succirubra plant are described. Results of feeding experiments with L-tryptophan using two different culture procedures are presented and discussed. Maximum alkaloid yields of up to 0.9% (based on dry weight) or 6.35 mg/l have been obtained.     

Characterization of messenger RNA for aldolase B in adult and fetal human liver

High molecular weight cellular RNA was isolated from adult and fetal human liver tissue by a procedure of ethanol precipitation in concentrated guanidine-HCl solutions. About 5 mg of RNA were obtained from one gram of liver. RNA was fractionated by sucrose gradient ultracentrifugation. Aldolase B neosynthesized in a reticulocyte lysate cell-free system under the direction of total or fractionated RNA was purified by immunoaffinity microchromatography. Messenger RNA specifying synthesis of aldolase B exhibited a sedimentation coefficient of 16 S both in adult and fetal liver. This enzyme represented 1.3 % of the total neosynthesized proteins in adult liver, 0.1 % in the liver of a 6-month-old fetus and less than 0.01 % in the liver of a 4.5 month-old fetus.     

Safety evaluation of nuclear polyhedrosis virus replication in pigs

To evaluate the hygienic risk involved in using baculoviruses for insect pest control, safety studies are required. Pigs were chosen as representative test animals of commercial and agricultural importance. The tests were aimed at detecting virus propagation, immune reactions, and signs of acute infection (changes in body temperature and hematology profile, swelling of lymph nodes). Four of five animals inoculated with nuclear polyhedrosis virus showed a slight temperature rise at day 2 postinfection. After day 4 postinfection, no differences between infected animals and controls were observed. In the bioassay, virus activity could be recovered from fecal samples; however, no activity was found in organ extracts. The data did not indicate hygienic risks involved in the application of nuclear polyhedrosis virus, especially that from Mamestra brassicae, in biological pest control.     

Proteolytic processing of human intestinal lactase-phlorizin hydrolase precursor is not a prerequisite for correct sorting in Madin Darby canine kidney (MDCK) cells.

Maturation of lactase-phlorizin hydrolase (LPH) (EC 3.2.1.23-62) requires proteolytic processing of precursor (pro-LPH) to mature microvillus membrane enzyme (m-LPH). Subcellular site and function of this processing are unknown. We studied the processing and sorting of human LPH expressed permanently in MDCK cells. LPH was inserted into the apical membrane and small amounts were found basolateral. Of the LPH immunoprecipitated from the apical membrane, 42% was in the mature, i.e. proteoytically processed form; on the basolateral membrane it was 20%. Thus, LPH-processing occurs after sorting and is not necessary for surface expression.     

Influence of the mode of reactor operation on the rate and yield of fermentation of the model solid substrate,wheat bran,by a microbial consortium under non-axenic anaerobic conditions

Summary Anaerobic fermentation of wheat bran, a model solid substrate, was conducted under non-axenic conditions, in two reactors operated under different modes, all other conditions being strictly identical. The first reactor was a completely-mixed batch reactor. The second reactor was a percolator into which the liquid phase was recirculated in closed loop through the solid substrate acting as a stationary bed. The final yield of fermentation was obtained after 27 days in the completely-mixed batch reactor, and after 14 days only in the percolator. Scanning electron microscopy revealed that numerous micro-organisms adhered to the solid substrate acting as a carrier in the percolator, whereas only very few micro-organisms adhered to the solid substrate in the completely-mixed batch reactor. The results show that obtaining a durable direct contact between micro-organisms and their solid substrate improves the rate of solids degradation.     

Selenium in the central nervous system of rats exposed to 75-Sel-selenomethionine and sodium selenite

The aim of the present study is to investigate the accumulation and retention of organic and inorganic selenium in the central nervous system (CNS) of the rat. Selenium accumulation was investigated after oral treatment (3.0 mg Se/L drinking water) or ip injection (1.7 mg Se/kg body wt) of rats exposed to 75-Se L-selenomethionine (SeMeth) or sodium selenite (NaSe). Significant higher concentrations were observed after exposure to organic compared to inorganic selenium after oral as well as ip administration. Highest concentrations in both experiments were observed in cerebellum followed by the nearly identical levels in the cerebral hemisphere and spinal cord independent of the chemical form of selenium or the route of administration. The difference in concentrations observed between the different parts of the CNS investigated in each group were, however, not significant. Retention of selenium in the CNS was investigated after a single ip injection (1.7 mg Se/kg body wt) of 75-Se SeMeth or NaSe. In both groups, we observed an initial fast excretion phase followed by a slower excretion phase resembling a first-order reaction. Organic selenium disappeared much slower from all parts of the central nervous system compared to NaSe after a single injection.     

Genetic and biochemical characterization of a new chymotrypsin isozyme of the house mouse,CTRA-1

Genetic variation of a codominantly inherited pancreas protease, designated CTRA-1, was discovered in the house mouse by isoelectric focusing in polyacrylamide gels. Phenotype CTRA-1A was found in MOLH/Fre and in the majority of common laboratory mouse strains. Phenotype CTRA-1B was found in PWD/Ph. It was characterized by the absence of a corresponding protease band. A third phenotype, CTRA-1C, was observed in IS/Cam and a fourth phenotype, CTRA-1D, was detected in SEG/1. CTRA-1 was found only in the pancreas and may represent the A form of chymotrypsin. The enzyme was shown to be controlled by the presumed structural locus Ctra-1 located on chromosome 8. From two backcross series, including a total of 274 animals, the gene order (Es-1, Es-9)-3.9 +/- 1.7%-Got-2-3.9 +/- 1.7%-(Es-2, Es-7, Es-23)-0.7 +/- 0.5%- Ctra-1-6.3 +/- 2.2%-Prt-2 was established.     

Sensory and secretory cells ofOphryotrocha puerilis (Polychaeta)

Summary As revealed by glyoxylic acid induced fluorescence, the protandric polychaeteOphryotrocha puerilis possesses different types of catecholaminergic primary bipolar sensory cells, the perikarya of which are located beneath the epidermis. About 20 of such receptors are situated in each segment but they are mostly found on antennae, palps, urites and parapodial cirri. The dendrites of these sensory neurones run to the cuticle and dilate to form receptive endings. Three different types of dendritic endings could be distinguished: (1) multiciliary receptors with 4–8 cilia and ciliary rootlets, (2) monociliary receptors with microvilli arranged like a funnel and electron-dense cuffs and (3) monociliary receptors of the collar-type with, constantly, ten microvilli surrounding one single central cilium. The latter type is also characterized by rootlet fragments. Dendrites and dilated receptive endings of all three types contain clear (putative secretory) vesicles, multivesicular bodies and mitochondria. Pharmacological treatment (dopamine, reserpine) does not affect the number of secretory vesicles of the receptor neurones. Extra vesicular storage of catecholamines is discussed. Secretory cells of unknown function containing large numbers of electron-dense vesicles are usually found in close association with sensory cells.Abbreviations CA catecholamines - DA dopamine - RE reserpine     

Cholesterol oxidase catalyzed oxidation of cholesterol in mixed lipid monolayers: effects of surface pressure and phospholipid composition on catalytic activity

The catalytic activity of cholesterol oxidase from Streptomyces sp. in mixed monolayers of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), N-oleoylsphingomyelin (O-SPM), and cholesterol (CHL) has been determined at lateral surface pressures between 10 and 30 mN/m. The highest cholesterol oxidase activity (determined at 37 degrees C) was observed at surface pressures around 20 mN/m in a POPC/CHL monolayer (50:50 mol %). Above and below this surface pressure, the enzyme activity decreased markedly. A similar optimal activity vs surface pressure relationship was observed also for an O-SPM/CHL monolayer (50:50 mol %). The activity of cholesterol oxidase toward cholesterol in the O-SPM/CHL monolayer was, however, less than in the corresponding POPC mixed monolayer. The surface activity of cholesterol oxidase decreased markedly when the temperature was lowered to 20 degrees C, and hardly any enzyme activity was observed in an O-SPM/CHL monolayer at 25 mN/m or above. With a monolayer containing POPC/O-SPM/CHL (42:18:40 mol %), maximal cholesterol oxidase activity was observed at the lowest surface pressure tested (i.e., 10 mN/m), and the catalytic activity decreased markedly with increasing lateral surface pressures in the monolayer. The results of this study show (i) that the activity of cholesterol oxidase in general is highly dependent on the lateral surface pressure in the substrate membranes and (ii) that sphingomyelin, by interacting tightly with cholesterol, can prevent or restrain the accessibility of cholesterol for oxidation by cholesterol oxidase.