Dictyocaulus viviparus: Migration in agar of larvae subjected to a variety of physicochemical exposures

Dictyocaulus viviparus larvae were exposed to ox bile and CO₂ at intervals during their cultivation to the infective stage. Preinfective and young infective larvae were stimulated by CO₂. Bile slightly inhibited preinfective larvae, but stimulated the infective stage. Old coiled, resting infective larvae were stimulated by bile down to a concentration of 10 ppm of bile dry matter, by vertebrate biles of pig, sheep, newborn calf, cow, guinea pig, dog, and chicken, as well as by defatted bile dry matter and by glyco-, tauro-, glycodeoxy-, and taurodeoxycholates. Continuous bile exposure appeared necessary to maintain high larval activity. A high pCO₂ as well as a low redox potential potentiated the effect of bile, but had no effect alone. Exposure to pepsin-HCl and to trypsin had only a minor stimulatory effect.     

Bromine oxidation of 1,2-O-isopropylidene-α-d-Glucofuranose and sucrose

Sucrose and $\text{1,2-O-}\text{isopropylidene-α-}\text{d}\text{-glucofuranose}$ (1) were oxidised with bromine in aqueous solution at pH 7 and room temperature. The resulting keto derivatives were converted into their more-stable O-methyloximes, which were characterised by spectroscopic and chromatographic methods. Oxidation of 1 occurred at C-3 and C-5, with a preference for C-5. In the sucrose derivatives isolated after oxidation, those having a keto group in the glucopyranosyl moiety preponderated. The axial fructofuranosyl aglycon protects position 3 in the glucopyranosyl group and oxidation occurs only at C-2 and C-4. Small amounts of sucrose oxidised at C-3 in the fructofuranosyl moiety were also found.     

Oxygen affinities of maternal and fetal hemoglobins of the viviparous seaperch,Embiotoca lateralis

Summary The striped seaperch,Embiotoca lateralis, is a viviparous teleost. The hemoglobins of adult and fetal seaperch are both tetrameric proteins which in their native state appear to be indistinguishable from one another by electrophoresis. However, differences in the subunit structure of maternal versus fetal seaperch hemoglobins can be detected by electrophoresis in urea with a reducing agent, amino acid analyses and peptide maps of the respective proteins. Furthermore, stripped adult and fetal hemoglobins have different oxygen binding affinities at all pH's tested between pH 6.8 and 8.0. Mid-gestation fetal hemoglobin has a higher oxygen affinity than late-gestation fetal hemoglobin which in turn has a higher affinity than that of the adult hemoglobin. All three stripped hemoglobins show a similar Bohr effect (=–0.9). These data suggest that a difference in oxygen affinities exists in vivo between the adult and fetal blood of the seaperchEmbiotoca lateralis and that it can be explained in part by the presence of a structurally unique fetal hemoglobin. This report is the first to provide evidence for a mechanism of maternal-fetal oxygen transfer in a teleost fish.Abbreviations A adult - LF late-gestation fetal - MF mid-gestation fetal (hemoglobins)     

Vascular reactions to horseradish peroxidase in the guinea pig

Summary Albino guinea pigs were given intradermal injections of the protein tracer horseradish peroxidase. In a 0.1 mM concentration the tracer did not increase vascular permeability to Evans blue-labelled plasma proteins. In a 1 mM concentration, however, the peroxidase induced a local vascular leakage. This leakage was almost totally inhibited by pretreating the animals with acetylsalicylic acid, while antihistamine had only a weak inhibitory effect. We therefore believe that prostaglandins are important mediators in this HRP-induced vascular reaction.     

Dipeptidyl peptidase IV inhibits the polymerization of fibrin monomers

A highly purified dipeptidyl peptidase IV from human placenta cleaves glycylproline from the N-terminal end of the fibrin α chain and inhibits the clotting of fibrin monomers. This result underlines the importance of the amino terminus of the fibrin α chain as an aggregation site masked by fibrinopeptide A. We speculate that the peptidase may hinder blood coagulation in intact vessels in vivo, because it is located on the surface of the capillary endothelium.     

Hyperostotic fish bones (“Tilly bones”) from presumably Pliocene phosphorites of the Lake Manyara area,northern Tanzania

PalZ - Hyperostotic fish bones from the presumable Pliocene phosphate-bearing deposits along Lake Manyara, Tanzania, are described. In contrast to marine occurrences of this kind, the pathological...     

Helospectin-like immunoreactivity in the esophagus

Helospectin I and II are two non-amidated, VIP-like peptides, isolated from the salivary gland venom of the lizard Heloderma horridum. The lower esophagus of cat, sheep and man was analyzed for helospectin-like immunoreactivity.

Immunocytochemistry revealed helospectin-immunoreactive nerve fibers in the muscle layers, submucosa and mucosa of all species studied. In myenteric ganglia helospectin-immunoreactive nerve fibers and nerve cell bodies could be seen. Double immunostaining for helospectin and vasoactive intestinal peptide (VIP) revealed their coexistence in nerve fibers and cell bodies throughout the lower esophagus of all species tested. Double immunostaining for helospectin and neuropeptide Y revealed their coexistence in nerve fibres surrounding vascular and non-vascular smooth muscle. In the cat and sheep (but not in man) a subpopulation of the helospectin/VIP-containing fibers stored, in addition, substance P.

The helospectin-immunoreactive material in the esophagus probably constitutes a novel neuropeptide. The distribution of the VIP/helospectin-immunoreactive neurons and fibers indicates their possible involvement in the regulation of motor and secretory activities.     

The xylanase introns from Cryptococcus albidus are accurately spliced in transgenic tobacco plants

The xylanase gene from Cryptococcus albidus contains seven introns. Genomic and cDNA clones under the control of the CaMV 35S promoter were transferred into tobacco plants using Agrobacterium-mediated cell transformation. The genes were transcribed and the mRNAs were amplified by the polymerase chain reaction using primers on each side of the intron region. About 90% of the amplification products from plants transformed with the genomic clone corresponded to the size of the pre-mRNA (1.2 kb) and 10% represented the spliced product (0.85 kb). The 0.85 kb fragment was cloned and sequenced and the result indicated that the introns from the xylanase gene were accurately spliced by the plant cells.     

Purification and some properties of an extracellular l-amino acid oxidase from Cellulomonas cellulans AM8 isolated from soil

Summary The soil isolate Cellulomonas cellulans AM8 produces an extracellular l-amino acid oxidase (L-AAO) with broad substrate specificity. The strain produced up to 0.35 unit (U)/ml of the extracellular L-AAO in a simple medium containing glycerol and yeast extract. The enzyme was easily purified up to 30 U/mg protein using Phenyl-Sepharose fast flow. The purified enzyme migrated as single band on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) with a molecular mass of 55 kDa. On native PAGE the molecular mass was approx. 300 000 kDa, which may be due to aggregation. With the exception of glycine, proline, and threonine, all the amino acids normally constituting proteins were oxidized. The V _max values from 0.7 to 35.2 U/mg for aspartic acid and lysine, respectively, and the K _m values from 0.007 to 7.1 mm for cysteine and valine, respectively, were obtained at 25° C and pH 7.0 in oxygen-saturated solutions. The L-AAO had a pH optimum of 6.5–7.5. It was stable for several months at — 30° C and for some days at 35° C. Ferricyanide served as an electron acceptor with a V _max of 50 U/mg and K _m for 0.3 mm with phenylalanine as the substrate. Correspondence to: R. D. Schmid