Effect of treatment with glutaraldehyde-fixed myelin basic protein-liposomes on active induction and passive transfer of experimental allergic encephalomyelitis in Lewis rats

Guinea pig myelin basic protein (MBP)-liposomes were prepared and fixed with 0.2% glutaraldehyde (GA). Lewis rats were treated with glutaraldehyde-fixed MBP-liposomes (MBP-L-GA) or with cytochrome-c-liposomes (CYC-L-GA), 7 days before and 7 days after challenge with MBP in CFA. Rats treated with MBP-L-GA, but not with CYC-L-GA, were very well protected against the clinical manifestations of EAE. The protection was better than that obtained after treatment with conventional MBP-liposomes (without glutaraldehyde). Furthermore, when grown in vitro for 72 hr in the presence of MBP, lymphocytes from rats treated with MBP-L-GA and challenged with MBP in CFA exhibited a marked decrease in their ability to transfer EAE to normal syngeneic recipients.     

Vernonia galamensis,Potential new crop source of epoxy acid

Vernonia galamensis is a good source of seed oil rich in epoxy acid, which can be used to manufacture plastic formulations, protective coatings, and other products. Seed from a natural stand in Ethiopia contained 31% epoxy acid. Under cultivation in Kenya, this unimproved germplasm produced a substantial yield of seed with 32% epoxy acid. This African species has good natural seed retention and is a promising new crop for semiarid tropical areas.     

Photolabeling of a O2-. generating protein in bovine polymorphonuclear neutrophils by an arylazido NADP+ analog

A plasma membrane fraction of bovine polymorphonuclear neutrophils enriched in NADPH-dependent, O2-. generating oxidase activity, and a number of fractions solubilized in detergent, recovered during the course of the purification of this oxidase have been tested for their ability to react with radiolabeled N-4-azido-2-nitrophenyl aminobutyryl NADP+ (arylazido NADP+ or NAP4-NADP+). In the dark, NAP4-NADP+ and its reduced form NAP4-NADPH, were found to inhibit competitively the NADPH-dependent O2-. generating oxidase activity of the plasma membrane fraction of bovine neutrophils activated by phorbol myristate acetate. The nitrene derivative formed upon photoirradiation of NAP4-NADP(H) bound covalently to different proteins of the plasma membrane. Photolabeling of these proteins was prevented by preincubation with an excess of NADPH. Photolabeling of a protein of 65,000 Mr was decreased by omission of phorbol myristate acetate as activating agent of the respiratory burst in neutrophils or by addition of micromolar amounts of Cibacron Blue and mersalyl which are known to inhibit the production of O2-. by the plasma membrane fraction. During the course of the purification procedure, the 65000 Mr protein emerged as the preferentially photolabeled protein. These data, in agreement with previous findings concerning the purification of an NADPH-dependent, O2-. generating oxidase protein of Mr 65000 from bovine neutrophils (Doussière, J. and Vignais, P.V. (1985) Biochemistry 24, 7231-7239), strongly suggest that a single protein of Mr 65000, located in the plasma membrane fraction of bovine neutrophils, is able to act both as an NADPH deshydrogenase and as an oxygen reductase to generate O2-.     

Pollen flow in Psiguria warscewiczii: a comparison of Heliconius butterflies and hummingbirds

Summary Pollen dispersal by male and female Heliconius butterflies and hermit hummingbirds was examined in a natural population of the tropical vine Psiguria warscewiczii. Fluorescent dyes were used to track flowers visited by individual pollinators. Mean distance of pollen dispersal was significantly higher by males than by female Heliconius. Butterflies dispersed pollen greater distances than did hummingbirds. There were no significant differences in dispersal distance among species of Heliconius. The number of flowers or plants to which dye was dispersed was greater for Heliconius than for hummingbirds.The home range behavior and site specificity exhibited by Heliconius, together with the preference by most Heliconius species in the study site for Psiguria led us to examine the relationship between the butterflies' home range and its daily foraging among Psiguria. A Heliconius mark-recapture program was conducted simultaneously with the dye program. This study showed that individual butterflies, for which extensive recaptures were made, visited an area of Psiguria plants on any one day that corresponded to the area in which those butterflies were caught or observed. The area over which a butterfly moved was termed its home range; within home ranges relative movement by butterflies was estimated as the mean distance between sequential captures. This estimate differed significantly among species of Heliconius; males of all species moving greater distances than females.     

Detection of gonadotrophic hormones on isolated thecal interstitial cells of the domestic hen, Gallus domesticus, by an immunohistochemical method

Summary An immunohistochemical method was used to demonstrate the presence of gonadotrophins in isolated ovarian interstitial cells. The cells were obtained by collagenase digestion of large ovarian follicles after removal of the yolk and the granulosa layer. Using a peroxidase-labelled anti-rabbit serum with anti-chicken follicle stimulating hormone (FSH) serum raised in rabbits, a strong positive reaction was obtained. Anti-human FSH serum also produced a positive result but the reaction was weaker. There was no apparent difference in the staining reaction of cells which had been preincubated with ovine FSH serum. Treatment with anti-ovine luteinizing hormone (LH) resulted in a faintly positive reaction.The viability of the cells was tested by the Trypan Blue method and they were identified as steroid-producing cells by the histochemical demonstration of their 3-hydroxysteroid dehydrogenase activity.     

Influence of δ-Opioid Receptors on Production of Labeled Methionine5-Enkephalin in Murine Neuroblastoma Cells

Synthesis of methionine5-enkephalin by intact cells of murine neuroblastoma clone N1E-115 has been demonstrated both immunocytochemically and biochemically. In addition, N1E-115 cells possess homogeneous enkephalin (delta) receptors which inhibit prostaglandin E1-induced intracellular cyclic AMP formation. An assay was developed for measuring de novo synthesis of methionine5-enkephalin by pulsing cells in culture with radioactive methionine and isolating this pentapeptide to radiochemical purity by a procedure that included immunoaffinity chromatography specific for oxidized methionine5-enkephalin. This assay indicated that production of radiolabeled-methionine5-enkephalin was increased upon lengthy exposure of intact N1E-115 cells in the late logarithmic phase of growth to a nonproteolyzable analog of methionine5-enkephalin. This increase in synthesis of intracellular methionine5-enkephalin relative to control cells was prevented by prior incubation of the clone with naloxone, indicating that the response was mediated by the delta receptor.     

Successful transfer of embryos recovered from a cow with chronic cervicitis of mixed aerobic and anaerobic bacterial aetiology a case report

An imported 13-year-old Simmentaler cow was presented with severe purulent cervicitis and endometritis from which Corynebacterium pyogenes , Fusobacterium necrophorum , Bacteroides melaninogenicus and an untyped Clostridium perfringens were isolated. The endometritis responded to treatment but the cervix did not and remained fibrous, continuously patent and purulent. Natural pregnancy was considered unlikely and the cow was prepared as an embryo transfer donor. Eight embryos were recovered and six transferred, resulting in five confirmed pregnancies and four live births.     

Antimicrobial activity of some alkyltrimethylammonium bromides

n-Alkyltrimethylammonium bromides (CnTAB) have been synthesized with n-alkyl chain lengths of between C₅ and C₂₂. Antimicrobial activity was assessed as growth inhibitory activity (MIC) towards seven representative strains of micro-organisms and as bacterial activity towards Staphylococcus aureus, Saccharomyces cerevisiae and Pseudomonas aeruginosa . These data indicated that whilst the level of activity was generally parabolically related to n-alkyl chain length, separate dependencies existed for short (n < 10) and long (n > 10) chain substituents, with disproportionately large increases in activity, in the order of three log cycles, occurring as substituent chain lengths increased from n = 10 to n = 12. This is interpreted in terms of distinct mechanisms of action, binding site and/or physicochemical properties for extreme members of the series.     

Mating behavior,egg deposition,incubation period,and hatching in the clearnose skate,Raja eglanteria

Synopsis Adult clearnose skates, Raja eglanteria, were captured during the winters of 1981 and 1983, and observed to mate in captivity. Mating and egg depositions take place on the central west coast of Florida from December through mid-May. During copulation the male holds the trailing edge of the female's right or left pectoral fin firmly in his mouth, swings his tail beneath hers and inserts one clasper into the distal end of her reproductive tract. Copulation may last one to four hours during which time sperm pass from the urogenital papilla of the male along the clasper groove to the female. Sperm move cranially to the upper portion of the shell gland where they are stored and remain viable for at least three months. The ovum is fertilized in the shell gland. The egg case bears a prominent projection or horn at each corner. The two posterior ones are shorter and bear tendrils which are covered with a sticky substance that insures attachment to the substrate when the egg is deposited. Fertilized eggs are laid in pairs at intervals ranging from 1 to 13 days (mean of 4.5 ± 2.2 days). As development proceeds within the egg case a plugged slit on the lateral side of each horn opens and permits seawater to wash the developing embryo. Incubation periods for eggs maintained between 20–22°C decrease in duration throughout the egg laying season, ranging from 94 days initially to 77 days for eggs laid later in the spring. At hatching, the anterior end of the egg case ruptures, and the skate emerges abruptly with its pectoral fins rolled dorsally.