Rapid detection of hypoxanthine-guanine phosphoribosyltransferase on cellogel

Zusammenfassung 541 Serumproben von nichtverwandten Deutschen aus dem Kölner Raum wurden auf ihre Pt- und C3-Typen untersucht. Bei 537 Seren fand sich eine Überein-stimmung der Pt A-Typen mit den C3 F-Typen, der Pt AB-Typen mit den C3 FS-Typen und der Pt B-Typen mit C3 S-Typen. Die C3-Varianten F0.65S, F0.6S, F0.5S wurden als Pt AB bestimmt, die C3-Variante F0.55S wurde als Pt B bestimmt. Die Frage der Vergleichbarkeit der Systeme sowie die Untersuchungsmethoden werden diskutiert.

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Comparative studies on posttransferrin (Pt) and C3 in the polymorphism of the third component of human complement

Summary Sera of 541 unrelated Germans from the Cologne area were examined for their Pt and C3 types. There was correspondence between Pt A and C3 F, Pt AB and C3 FS, and Pt B and C3 S in 537 sera. C3 variants F0.65S, F0.6S, F0.5S were determined as Pt AB, C3 F0.55S was determined as Pt B. The question of possible identity and the methods used are discussed.

     

Naphthalene oxygenase fromCorynebacterium renale: Characterisation and mechanism of oxygenation

The formation ofcis-l,2,-dihydroxy-l,2,-dihydronaphthalene from naphthalene by naphthalene oxygenase, purified fromCorynebacterium renale ATCC 15075, was demonstrated to involve oxidation of a mol NADH and consumption of one mol oxygen. The enzyme contains one g-atom Fe²⁺ and one FAD. Catalase inhibited product formation and H2O2 could substitute for NADH in the reaction. Superoxide dismutase inhibited enzyme activity when either NADH or H₂O₂ was present; the generation of superoxide anion on addition of NADH to the enzyme, in the absence of naphthalene, was detected by the nitro blue tetrazolium reduction method. Hydroxyl radical scavengers, ethanol, mannitol and sodium benzoate, inhibited product formation when either NADH or H₂O₂ was present. Electron spin resonance studies, under aerobic conditions, indicated that iron of the enzyme underwent valence changes during the course of the reaction     

Inactivation by chloroquine of alpha-galactosidase in cultured human skin fibroblasts

When human skin fibroblasts are cultured in the presence of chloroquine or NH₄Cl there is a decrease in the intracellular level of lysosomal hydrolases and a concomitant increase in the extracellular activity as compared with cells grown in the absence of a base (cf [18]). In a medium with 25 μM chloroquine or 5 mM NH₄Cl, the decrease in the intracellular activity of β-hexosaminidase, arylsulphatase and β-glucuronidase is 10–40% after 1 day. A similar decrease in α-galactosidase activity is observed in cells grown in the presence of 5 mM NH₄Cl. However, in the presence of 25 μM chloroquine, the intracellular activity of α-galactosidase decreases by 80–90% within 6 h. The inactivation is irreversible. After removal of the chloroquine and further culture of the cells in chloroquine-free medium, α-galactosidase activity gradually increases due to de novo synthesis. The turnover time of α-galactosidase was calculated to be 1.9 days. Inactivation of α-galactosidase also occurs when homogenates are incubated with chloroquine, but the concentration of the base required for maximum inactivation is at least three orders of magnitude higher than that which must be present in the medium of intact cells to obtain the same effect.     

Human α-globin maps to pter-p13.3 in chromosome 16 distal to PGP

Summary Fibroblasts from a fetus with an unbalanced karyotype 46(XY),-16,+(16qter-16p13.3::4q31.1-4qter) were found to possess only one allele at the 3 hypervariable region (3HVR) close to the -globin locus and two alleles at the PGP locus. This places the -globin locus at the very tip of 16p, distal to PGP.     

A 4-base-pair deletion polymorphism in man

Partial nucleotide sequencing of C11p11, a probe mapping close to the gene determining familial adenomatous polyposis (FAP) on human chromosome 5, in 4 unrelated persons has revealed a 4-base-pair deletion variant designated DELI at an arbitrary DNA locus D5S71. For screening the deletion variants that may frequently occur in the non-coding DNA sequences, we set up a non-invasive procedure which involves DNA amplification by PCR, simple polyacrylamide gel electrophoresis and direct visualisation of alleles under long wave ultraviolet light by ethidium bromide staining.     

Micro-indentation hardness studies on human bones.

Bones from different portions of human skeleton are polished and cut to suitable sizes and then subjected to micro-indentation at various loads using Vicker's diamond pyramidal indenter. The Vicker's hardness number is found to differ slightly from portion to portion of the skeleton. Interferometric studies of the indentation reveal that the applied stress of indentation causes a 'pile-up' of material near the corners of the pyramidal indents.     

Assignment of human transcobalamin II (TC2) to chromosome 22 using somatic cell hybrids and monosomic meningioma cells

Summary Human transcobalamin II (TC2), a vitamin B12 binding serum protein, is synthesized and secreted into the medium by cells growing in vitro. Mouse-man somatic cell hybrids were analyzed in order to map the locus of TC2. The presence of human TC2 in the culture media was correlated with the results of genetic marker and chromosome analysis of the hybrid cells. Chromosome 22 showed 100% concordancy. However, chromosome 6 (90% concordancy) and chromosome 7 (96% concordancy) were not completely excluded. Meningioma cells obtained from patients heterozygous for TC2 showed a concomitant loss of one chromosome 22 and one of the TC2 alleles, strongly supporting the assignment to chromosome 22.