Endocrine profiles and embryo quality in the PMSG-PGF2alpha treated cow

Plasma progesterone and LH concentrations around estrus were determined for both PMSG treated (experimental animals) and non-treated (control animals) dairy cows and heifers of the Holstein Friesian and Jersey breeds, and these hormone profiles were related to the embryo quality. Most experimental animals experienced an increase in progesterone concentrations following PMSG treatment and an abrupt decrease to values below 3 nmol/l after PG injection. The mean (+/-SE) intervals from prostaglandin treatment to estrus were 46.9+/-1.8 h and 64.5+/-4.8 h for experimental and control animals, respectively. At the onset of heat the progesterone concentration in experimental animals with optimal embryo quality (group I) was significantly lower (p<0.01) than in experimental animals which yielded unfertilized eggs (group II) (1.2+/-0.1 versus 3.9+/-0.8 nmol/l) and significantly higher than the level in the control group (0.6+/-0.1 nmol/l). Following estrus the progesterone profiles in all 3 groups were studied and the length of the superovulatory cycle was measured to 26.0+/-4.8 days. The preovulatory LH surge occurred sooner after prostaglandin injection in experimental (41 h) than in control animals (65 h). The LH surge in group I occurred within a narrow range and reached a higher average level than group II (24.2+/-2.2 ng/ml and 16.3+/-3.7 ng/ml, respectively). The control group attained an even higher LH surge (31.8+/-8.8 ng/ml) than did the experimental animals. The data presented in this experiment indicate that plasma levels of progesterone and LH in PMSG-PGF(2)alpha treated animals are related to embryo or egg quality.     

Ribosomal RNA sequence conservation and gene number in the larval brine shrimp

The haploid genome size of Artemia is determined to be about 0.9·10¹², as evidenced both by Feulgen microspectrophotometry of individual diploid class nuclei, which are but one of five polyploid classes present within the larvae, and by analysis of the reassociation kinetics of the isolated single copy DNA component. Polysomes isolated from 24-h incubation stage larvae contain an average of 10 ribosomes per messenger RNA molecule. Their rRNAs are found to have sedimentation coefficients of 18 S and 26 S, corresponding to molecular weights of 0.70·10⁶ and 1.40·10⁶, respectively, as determined by polyacrylamide electrophoresis and also by sucrose density centrifugation. Denaturation in glyoxal followed by agarose gel electrophoresis shows that unlike deuterostome rRNAs, Artemia 26 S rRNA contains a cryptic nick about midway in the molecule, which is not found in the 18 S molecule. Isolated rRNAs were labelled in vitro with ¹²⁵I and hybridized with filter-immobilized DNA to saturation, which occurred at 0.051% for Xenopus, and at 0.074% for Artemia. From these results, it is calculated that in the haploid Artemia genome there are about 320 copies of the (18 S + 26 S) ribosomal RNA genes. Reciprocal heterologous hybridizations between these two species show that they share about 30% homology between their rDNA coding sequences.     

Lipoxygenbase-derived products of arachidonic acid mediate stimulation of hexose uptake in human polymorphonuclear leukocytes

The titration of metal-freed bovine α-lactalbumin with Mg²⁺ ions causes a two-stepped decrease in the tryptophan fluorescence quantum yield and a pronounced spectral shift towards shorter wavelengths, which seems to be a result of the binding of two magnesium ions to the protein molecule. The magnesium binding constants evaluated from the fluorimetric Mg²⁺-titration are 2·10³ and 2·10² M^?1. Mg²⁺ ions in millimolar concentrations almost do not influence the binding of Ca²⁺ ions to the protein.     

Cyclic guanosine 3',5'-monophosphate and phosphodiesterase activity in mitogen-stimulated human lymphocytes.

The cyclic adenosine 3′,5′-monophosphate (cyclic AMP) phosphodiesterase from human leukemic lymphocytes differes from the normal cell enzyme in having a much higher activity and a loss of inhibition by cyclic guanosine 3′,5′-monophosphate (cyclic GMP). In an effort to determine the mechanism of these alterations, we have studied this enzyme in a model system, lectin-stimulated normal human lymphocytes. Following stimulation of cells with concanavalin A (con A) the enzyme activity gradually becomes altered, until it fully resembles the phosphodiesterase found in leukemic lymphocytes. The changes in the enzyme parallel cell proliferation as measured by increases in thymidine incorporation into DNA. The addition of a guanylate cyclase inhibitor preparation from the bitter melon prevents both the changes in the phosphodiesterase and the thymidine incorporation into DNA. This blockage can be partially reversed by addition of 8-bromo cyclic guanosine 3′,5′-monophosphate (8-bromo cyclic GMP) to the con A-stimulated normal lymphocytes. These results indicate a possible role of cyclic GMP in a growth related alteration of cyclic AMP phosphodiesterase.     

Simultaneous analysis of phenylglycols and phenylethanols in human urine by gas chromatography—mass spectrometry

A method is described for the determination of the neutral metabolites formed from catecholamines and various other structurally related phenylethylamines by using gas chromatography—chemical ionization—mass spectrometry. These metabolites (phenylglycols and phenylethanols) were extracted from urine specimens and converted to pentafluoropropionyl derivatives which were separated on either 3% OV-1, 3% SP-2250, or 3% QF-1 packed columns. Our results demonstrate the presence in human urine of p-hydroxyphenylglycol, a metabolite of octopamine. One patient excreted 13 and 91 μg/day of free and total (free + conjugated) p-hydroxyphenylglycol, respectively. Treatment with a monoamine oxidase inhibitor reduced the excretion of total p-hydroxyphenylglycol to 30% of baseline level.     

Two different gamma-glutamyltransferases during development of liver and small intestine: a fetal (sialo-) and an adult (asialo-) glycoprotein.

Depending on the developmental stage, the gamma-glutamyltransferase (E.C. 2.3.2.2) exists in two different types in the liver and in the small intestine: a sialic acid-rich fetal type and a sialic acid-poor adult type. The fetal type could be detected in the undifferentiated cryptal cells, in the fetal small intestine and in the fetal liver, and the adult type in the differentiated villous cells and in the adult liver. The separation of both types was performed using ConA-sepharose, which does not bind the fetal type but the adult type. Binding was reached by neuraminidase treatment.     

Cell shape changes and transmembrane receptor uncoupling induced by tertiary amine local anesthetics

Tertiary amine local anesthetics (dibucaine, Tetracaine, procaine, etc.) modify cell morphology, concanavalin A (Con A)-mediated agglutinability and redistribution of Con A receptors. Con A agglutination of untransformed mouse 3T3 cells was enhanced at low concentrations of local anesthetics, and the dynamics of fluorescent-Con A indicated that ligand-induced clustering was increased in the presence of the drugs. In contast, these drugs inhibited Con A-induced receptor capping on mouse spleen cells. These effects can be duplicated by combinations of vinblastine (or colchicine) and cytochalasin B suggesting that local anesthetics act on microtubule cell surface receptor mobility and distribution. It is proposed that tertiary amine local anesthetics displace plasma membrane-bond Ca²⁺, resulting in disengagement of microfilament systems from the plasma membrane and increased cellular Ca²⁺ concentration to levels which disrupt microtubular organization. The possible involvement of cellular Ca²⁺ in cytoskeletal destruction by local anesthetics was investigated utilizing Ca²⁺-specific ionophores A23187 and X537A. In media containing Ca²⁺ and cytochalasin B these ionophores caused effects similar to tertiary amine local anesthetics.     

Purification and chemical study of a Collocalia glycoprotein]

A glycoprotein was purified from the aqueous extract of "edible bird's nest" (Collocalia) using free flow preparative electrophoresis and represented the main fraction of Collocalia glycoproteins. This glycoprotein is homogeneous upon agarose electrophoresis and slightly polydisperse upon ultracentrifugation (S So 20w = 3,0). The carbohydrate moiety contains galactose, mannose, glucosamine, galactosamine and sialic acid, which is completely released by Clostridium perfringens or Diplococcus pneumoniae neuraminidases and has the same chromatographic behaviour as N-acetyl-neuraminic acid. The peptide part of the glycoprotein is rich in serine, threonine and proline. About 40 p. cent of the hydroxyaminoacids are involved in carbohydrate-peptide linkages.