Purification to apparent homogeneity of a thymocyte specific growth factor from calf thymus

A thymic peptide previously found to recruit thymocytes from G1 into S phase has been purified from a crude thymic extract by subsequent steps of gel exclusion chromatography and reverse phase high performance liquid chromatography (HPLC). The purified material, which appeared homogeneous on thin-layer chromatography and HPLC, stimulated the DNA synthesis of cultured guinea pig thymocytes in a nanomolar concentration range. The amino acid composition revealed a high content of acidic amino acids and no apparent homology to previously defined growth factors and thymus differentiation hormones.     

Homeostatic responses to water deprivation or hemorrhage in lactating and non-lactating Bedouin goats

Three lactating and three non-lactating black Bedouin goats were subjected to four days of water deprivation or to hemorrhage. Four days of water deprivation caused body wt losses of 32 and 23% and plasma volume losses of 30 and 34% in lactating and non-lactating goats respectively. Plasma osmolality increased 17 and 15% in lactating and non-lactating goats. Plasma arginine vasopressin concentration rose from about 5 pg/ml to a mean of 36 pg/ml. Plasma renin activity increased from about 0.7 ng/ml/hr to a mean of 3.45 ng/ml/hr in lactating and to 3.15 ng/ml/hr in non-lactating goats. At 4.5 hr post-rehydration plasma osmolality and plasma vasopressin concentration were back to normal in non-lactating, but still elevated in lactating goats. Plasma renin activity increased after rehydration. Rapid blood volume loss of 21-28% increased plasma vasopressin concentration to 16-35 pg/ml in non-lactating and to 70 or greater than 500 pg/ml in lactating goats. It is concluded that black Bedouin goats are well adapted to endure severe dehydration and rapid rehydration, but that they (especially lactating animals) react strongly to rapid volume depletion.     

Elastases from human and canine granulocytes, II. Interaction with protease inhibitors of animal, plant, and microbial origin.

Inhibitors of animal, plant, and microbial origin were tested against human and canine granulocytic elastases. The trypsin-chymotrypsin inhibitors from dog submandibular glands, from soybeans (Bowman-Birk) and from chickpeas show strong interaction with these proteases (Ki = 10(-8) - 10(-9)M). The trypsin-kallikrein inactivator of bovine organs (Trasylol) is not active against granulocytic elastases or against human granulocytic cathepsin G. Elastatinal, a specific inhibitor of elastases, isolated from actinomycetes (Streptomyces griseoruber), forms stable complexes with elastase from human (Ki = 6.2 X 10(-6)M) and canine granulocytes (Ki = 1.1 X 10(-6)M). A possible therapeutic application of these inhibitors for the inactivation of granulocytic proteases, which are able to degrade connective tissue in different pathological states, is discussed.     

Purification of human granulocyte catalase in chronic myeloid leukemia.

Human granulocyte catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase, EC 1.11.1.6) was purified from chronic myeloid leukemia cells. The purification procedure included heat precipitation, ammonium sulphate fractionation, DEAE-Sephadex chromatography, gel chromatography on Sephadex G-200 and isoelectric focusing with an approximate yield of 30% and a 1000-fold purification. The molecular weight of the subunit obtained by sodium dodecyl sulphate electrophoresis was 65 800. So20,w was 11.6 +/- 0.24. The pH-optimum was 6.6-6.7 and the spectrum showed a major peak at 405 nm and shoulders at 500, 540 and 625 nm typical for catalase. The electrophoretic mobility was towards the anode at pH 8.6 and identical to normal granulocyte and erythrocyte catalase. These three species of catalase gave the reaction of identity on immunodiffusion and crossed immunoelectrophoresis. The content of catalase and its activity of isolated granulocytes were approximately identical in normal and chronic myeloid leukemia granulocytes while the specific activity of leukemic catalase was higher than normal. No difference in catalase content was found between mature and immature leukemic granulocytes.     

Leukotriene A: stereochemistry and enzymatic conversion to leukotriene B

Leukotriene A was assigned the structure 5(S)-$\text{trans}$-5,6-oxido-7,9-$\text{trans}\text{-11,14-}\text{cis}$-eicosatetraenoic acid by the enzymatic conversion of a synthetic product of known stereochemistry into the naturally occurring isomer of 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid in human polymorphonuclear leukocytes.     

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.     

Overwintering of benthic macroinvertebrates in ice and frozen sediment in a North Swedish river

In winter the water freezes into the substrate within considerable areas of unregulated northern rivers due to low temperature combined with a lowering of the water level. Living individuals of Nematoda, Gastropoda, Sphaeriidae, Oligochaeta, Hirudinea, Isopoda, Trichoptera and Chironomidae were found in samples of ice and frozen sediment from the bottom frozen hydrolittoral zone of the north Swedish river Vindelälven. All abundant species in the frozen substratum, except Asellus aquaticus , seemed to be well adapted to withstand overwintering in this special habitat free from predation. Generally, between 80 and l00% of enclosed animals survived thawing. Cysts or other kinds of resting stage constructions, similar to those found during drought, were common in several enclosed species. Specimens of Gyraulus acronicus, Pisidium ssp., Molanna albicans and Chironomidae survived exposure to −4°C for five month in a freezing experiment. Extracellular freezing of the invertebrates overwintering in the ice is probable, as the ambient temperature was below the true freezing point of most animals. The composition of the substratum may effect the survival of animals enclosed in ice.     

Isolation and characterization of the dut gene of Escherichia coli. II. Restriction enzyme mapping and analysis of polypeptide products

Restriction endonuclease mapping of previously constructed dut plasmids has been carried out using the enzymes PvuI, PvuII and SacI. Various dut plasmids were also tested in the "maxicell" protein-synthesizing system. They all show two protein bands in common, one of Mr 16000 in agreement with the size previously reported for the purified dUTPase subunit (Shlomai and Kornberg, 1978). With the information obtained the structural gene for dUTPase can be assigned to a 950-bp SacI-PvuII fragment of the E. coli genome. Studies, described in the preceding paper, on the overproduction of dUTPase by bacterial strains carrying different dut plasmids strongly suggest that the dut gene is transcribed in the direction from the SacI site towards the PvuII site and that the SacI site is located within the dut control region. The second protein band observed in the "maxicell" experiments has an Mr of 23500. Its identity is unknown but it may represent a precursor of dUTPase or the product of a separate gene located between dut and pyrE.     

Ig H chain variable and C region genes in common variable immunodeficiency. Characterization of two new deletion haplotypes.

Common variable immunodeficiency, a disorder characterized by diminished antibody production, manifests clinically as an increased susceptibility to bacterial infections. We have investigated the Ig H chain V and C region gene segments in 33 patients with common variable immunodeficiency, to identify the possible role these genes may have in the molecular basis of the defect. No major deletions were recognized for the VH gene segments of the VH2, VH5, and VH6 families, nor were there any differences in the RFLP patterns of mu- or alpha- switch regions or of C gamma genes. Two new deletion haplotypes were identified for the C region genes, the first encompassing C gamma 1 on a different haplotype from the C gamma 1 deletion described previously, and the second a novel deletion encompassing both C gamma 2 and C gamma 4. Based on these and previously described deletions in the IGHC region, we postulate that homologous regions are involved in the deletion process and that other new deletions likely exist in the population.