Post-translational heterogeneity of the human vitamin D-binding protein (group-specific component)

The vitamin D-binding protein in human serum (the group-specific component) is an alpha 2-globulin which is genetically polymorphic in all populations studied. Previous work (J. Svasti and B. H. Bowman (1978) J. Biol. Chem. 253, 5188-5194, and J. Svasti, A. Kurosky, A. Bennett, and B. H. Bowman (1979) Biochemistry 18, 1611-1617) has shown that the electrophoretic variations of the proteins controlled by two allelic genes, Gc1 and Gc2, are due to at least three amino acid substitutions between Gc1 and Gc2 (Svasti et al. (1979] and to heterogeneity in the Gc1 phenotype arising from carbohydrate dissimilarities. Gc1 migrates electrophoretically as two protein bands, while Gc2 migrates cathodally as a single band. This study demonstrates a post-translational glycosylation difference occurring in a single area of the Gc1 sequence which accounts for the heterogeneity observed previously. The glycosylation site, a threonine residue, appears to be in a sequence which differs between Gc1 and Gc2. The O-glycosidic bond, which is typical of mucins, is rare in plasma proteins. The cyanogen bromide fragment containing the galactosamine-containing carbohydrate in Gc1 was partially sequenced through 20 residues from the amino terminus. No detectable galactosamine could be found in the homologous cyanogen bromide fragment in Gc2. A new purification procedure for the vitamin D-binding protein in human plasma has been developed. Three chromatographic steps provide purified protein.     

Kinetics of histone H10 accumulation and commitment to differentiation in murine erythroleukemia cells

The accumulation of histone H10 (also denoted IP 25) in murine erythroleukemia cells, induced to differentiate with hexamethylene bis-acetamide, was shown to precede by 15-20 h the appearance in the culture of cells irreversibly committed to differentiate. In addition the rates of accumulation of H10 and of committed cells vary in a similar manner with the HMBA concentration. Flow microfluorimetric analysis demonstrated that the accumulation of H10 did not occur simultaneously in all the cells. This accumulation of histone H10 was initiated first in cell in the G2 phase of the cell cycle and subsequently in the cells situated in all the phases of the cell cycle.     

Tolerance induction by the peroral administration of protein antigens

The possibility of inducing systemic tolerance in animals by feeding them with ovalbumin and human serum was studied on mice, rats and rabbits. Antibodies to ovalbumin, human serum albumin and immunoglobulins (IgG, IgA, IgM) were determined by the passive hemagglutination test in the sera of the test and control animals after the second immunization made through a parenteral route. Tolerance to all the antigens under study was obtained in mice and rats, while in rabbits such feeding was found to produce the priming effect. The degree of tolerance was the greater, the more was the dose of the antigen and the longer was the period of feeding. Different proteins showed varying tolerogenic activity; the same degree of tolerance in mice was obtained by feeding them with IgG in a dose of 0.3-0.5 mg and with ovalbumin or human serum albumin in a dose of 6-12 mg (per gram of body weight). Tolerance was determined on day 3 after the course of feeding was over; in 3 weeks tolerance essentially decreased, and in 1.5-2 months it was replaced by normal reactiveness. Tolerance induced by the oral administration of antigens proved to be immunologically specific.     

Cyclic AMP, the hyperresponsiveness factor from hog kidney

The isolation and identification of a material present in the plasma of hypertensive dogs and hypertensive human patients has been under study since 1972. The earliest experiments in relation to this work, noted that plasma from hypertensive dogs cause a hyperresponse to norepinephrine when both were administered by way of the vein. Employing a rat assay system that consisted of an anesthetized rat with polyethylene catheters in the vein for giving norepinephrine and the test fractions and a catheter in the artery for blood pressure monitoring, fractions from hog kidney were tested for hyperresponsiveness activity. The active material is very comparable to cyclic AMP in molecular weight, ultraviolet spectrum, paper chromatography, Enzyme hydrolysis and activity in the anesthetized rat system. This evidence indicates that the hyperresponsiveness factor of renal origin is cyclic AMP.     

Determination of the heat resistance of spores using a solid heating block system

A simple and accurate technique for the determination of the heat resistance of spores is described. The technique combines a modified capillary tube method with a solid heating block. The come-up time of spore suspensions was found to be short and simple and accurate technique is suggested for the correction of the come-up times. Experimental results are presented for the destruction of spores of Bacillus stearothermophilus at 120 which indicates the accuracy and reproducibility of the new method.     

Some dermatoglyphic traits in breast carcinoma

The finger and palmar prints of 60 women with breast carcinoma were studied. The results were compared with two groups of healthy women, the first consisted of old women and the second of young women. The dermatoglyphics seem to be of little use in the diagnosis of cancers of ectodermic origin. Supported by M.P.I. 60%, 1983     

Segregation Distortion of Marker Nuclear Genes in Alloplasmic and Isoplasmic Lines of Barley

Inheritance of barley nuclear genes responsible for various morphological marker traits was studied in hybrid populations F₂ and F_a. Nine marker genes showed deviation from Mendelian monogenic inheritance depending on the cross direction and maternal cytoplasm. Segregation biases to both recessive mutant and dominant normal phenotypes were observed. Mechanisms of the segregation bias related to cytoplasm substitution in iso- and alloplasmic lines are discussed.