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.     

Calcium and magnesium levels in isolated cardiac mitochondria from mice injected with isoproterenol

Summary Calcium (Ca) and Magnesium (Mg) are determined by atomic absorption flame spectrometry in isolated cardiac mitochondria from mice receiving subcutaneous injections of DL-isoproterenol HC1 (ISO), and in mitochondria of untreated controls. In the controls, mitochondria were isolated in the presence or absence of ruthenium red. On the absence of ruthenium red in the isolation medium, mitochondrial Ca levels increase by about 300%, while levels of Mg remain unchanged. Focal myocardial necrosis following a single ISO-injection is shown by electron microscopy. Ca and Mg levels are largely unaffected by a single dose of ISO until 24 h after the injection. A slight increase in Ca occurs in the 48 h samples. When multiple injections of ISO are given every 12th hour for 48 h, 72 h and 96 h, respectively, endogenous Ca and Mg increase significantly. It is suggested that this increase might be associated with ISO-induced cardiac hypertrophy rather than with the pharmacological effects of ISO per se.This work was supported by grants from The Norwegian Council on Cardiovascular Disease and from The Norwegian Research Council for Science and the Humanities     

Psoralen/UVA treatment and chromosomes

Summary Treatment of human lymphocytes in vitro with trimethylpsoralen or 8-methoxypsoralen and UVA irradiation (PUVA) induced chromosome damage, mainly constrictions and gaps, but also breaks and exchanges, and increased the frequency of sister chromatid exchange (SCE). The localization of the chromosome aberrations was nonrandom. The coincidence of many PUVA hits with mercaptoenthanol hits suggests that PUVA may have other targets in the cell than the DNA, perhaps the folding proteins of the chromosomes and the nuclear membrane/chromatin attachment organelles.Caffeine increased in a synergistic way the chromosome aberration yield if added after PUVA treatment, but there was no effect when caffeine was present before and during PUVA treatment. The SCE frequency was increased in the presence of caffeine.     

Absolute configuration of heteroxanthin and diadinoxanthin

The absolute configurations of heteroxanthin ((3S,5S,6S,3′R)- 7′,8′-didehydro-5,6-dihydro-β,β-carotene-3,5,3′,6′-tetrol) ex Euglena gracilis and of diadinoxanthin ((3S,5R,6S,3′R)-5,6-epoxy-7′,8′-didehydro-5,6-dihydro-β,β-carotene-3,3′-diol) from the same source have been established by chemical reactions, hydrogen bonding studies, ¹H NMR and CD. Two previously unknown carotenoids (artefacts?) from Trollius europaeus, assigned the structures (3S,5S,6S,3′S,5′R,6′R)-6,7-didehydro-5,6,5′,6′-tetrahydro-β,β -carotene-3,5,6,3′,5′-pentol and its 5R epimer, served as useful models.     

Fucose-containing polysaccharides in the brown algae Ascophyllum nodosum and Fucus vesiculosus

The fucose-containing, sulfated polysaccharides from Ascophyllum nodosum and Fucus vesiculosus were isolated by extraction with water adjusted to pH 2. Pure fractions were carefully separated by fractional precipitation with ethanol from aqueous solutions containing magnesium or calcium chloride. Progress in the fractionation efforts and purity of the fractions isolated were established by free-boundary and cellulose acetate clectrophoresis. Ascophyllan, two “complexes”, and a galactofucan were isolated from A. nodosum. An ascophyllan-like fraction, and a “complex” were isolated from F. vesiculosus. Mild, acid hydrolysis (0.02m hydrochloric acid, 1 h, 80°) converted each of the “complexes” into an electrophoretically faster-moving and a slower-moving component. The “complex” from F. vesiculosus comprised a greater proportion of the extract than did the two “complexes” from A. nodosum. In addition, the Fucus “complex” was richer in fucose*. However, the data suggest that neither species contains a pure fucan sulfate in the native state.     

Ontogenetic Development of Creatine Phosphokinase in Skeletal Muscles and Heart from Pigs

Creatine Phosphokinase (CPK) in striated muscles shows only small changes in activity before birth. After birth and during the first month of extrauterine life the activity increases rapidly. The largest increase is seen in muscles with a glycolytic energy metabolism (m. long, dorsi) and the smallest in muscles with an oxydative energy metabolism (m. flexor dig. ped. sup.). The differences between these groups of muscles are statistically significant. In heart tissue the increase in CPK activity is lower, the levels amounting to 40 to 47 % of those in striated muscles. Early in fetal life only the BB isoenzyme is found in striated muscles. Synthesis of M subunits of GPK starts between day 76 and 65 before birth and increases rapidly after this time leading to disappearance of the BB isoenzyme 24 days prior to birth and of the MB isoenzyme at birth. In muscles with an oxydative as well as in muscles with a glycolytic metabolism all GPK activity after birth is caused by the MM isoenzyme. All three isoenzymes are present in heart tissue at the earliest prenatal stage investigated, the pattern being dominated by the BB isoenzyme. During further differentiation the MM isoenzyme increases and the BB isoenzyme decreases. The development is completed during the first month after birth with a final isoenzyme composition of 81 % MM and 19 % MB isoenzyme. kw|Keywords|k]pigs; k]ontogenesis; k]creatine phosphokinase; k]activity; k]isoenzymes     

Receptors for the complement C3d component and the Epstein-Barr virus are quantitatively coexpressed on a series of B-cell lines and their derived somatic cell hybrids

Various human Burkitt lymphoma and LCL lines established in vitro and their derived somatic cell hybrids were tested for their comparative EBV receptor levels in a virus binding assay. Their graded C3b and C3d complement receptor expression was estimated simultaneously by means of isotope labeled rosette marker cells. The receptor concentration of each cell line was related to Raji as the standard of comparison, K 562, P3HR-1, and YACUT were used as negative controls. In general, the charging curves for EBV and C3d receptors parallelled each other (r = 0.97) while C3b receptor charging showed no correlation (r < 0.60). In the Raji hybrids between the C3b receptor positive Raji parent and various patents that were negative for this receptor, C3b receptor expression was low or negative. In contrast, the C3d negative P3HR-1 line gave rise to hybrids, after fusion with receptor-positive cells, that were intermediate with regard to their C3d receptor expression. The host range restriction of the Epstein-Barr virus is determined at the receptor level. The close relationship between the EBV receptor and the C3d receptor, a B-lymphocyte-specific moiety, suggests that the moderate interaction with EBV with the B lymphocytes may have had a selective advantage, favoring the presence of EBV. Since EBV causes lytic infections after artificial introduction into nonnatural host cells, it may represent a B-lymphocyte-specific host range mutant, derived from an originally lytic herpesvirus with a much broader target cell range.     

Thermal Rearrangement of 4-Alkyl-1,2,4-triazoles. Rearrangements in the Crystalline State

Studies of the thermolyses of 4-alkyl substituted 1,2,4-triazoles was reviewed. They were observed to rearrange at 200–350 °C to the corresponding 1-alkylated triazoles. When substituted in the 4-position with aryl- or vinylic substituents the triazoles were inert to thermolysis, contrary to what was observed for the 4-alkyl- and 4-allyl substituted systems. The mechanisms for the reactions were elucidated, e.g., by studies of substituents effects and by kinetic measurements in solution as well as for the neat samples. Reactions in solutions were slow. The rearrangements in melts of the neat triazoles readily proceeded to the products, and were proposed to take place via a series of nucleophilic displacement steps. X-ray crystallographic measurements of selected structures, showed that the interatomic distances and angles between the relevant atoms in these structures, to a large degree resembled the geometry expected for the S_N2-type transition states proposed for the rearrangement mechanism. Thus, thermolyses of a series of triazole structures at temperatures below their melting points, confirmed that rearrangements actually did take place. The “kinetics” of the reactions in the crystalline state were investigated and rate constants and thermodynamic data were correlated with the structural characteristics of the crystals.