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Biomedical subjects

N Blumenkrantz

Publications and source records attributed to N Blumenkrantz.

At least 37 records · Page 2Linked to original sources
PubMed1978

Hydroxyproline to hydroxylysine molar ratio indicates collagen type.

By using the molar ratio Hyp to Hyl, types I and II of collagen can be differentiated in 0.5 to 10 mg of dried, defatted tissue. Analyses on human skin, tendon, bone, aorta, cartilage, as well as nucleus pulposus, and annulus fibrosus of intervertebral discs are reported. Analyses of collagen of mesenchymal tissues of other vertebrates are also reported. From amino acid analysis of purified collagen samples published in the literature, the molar ratio Hyp/Hyl was calculated. Type I and type III collagen were differentiated from type II, and the latter was differentiated from type IV collagen. The molar ratios obtained with our analyses followed closely the values from previously reported amino acid analyses on purified collagen.

Amino Acids↗
PubMed1978

Subhydroxylated collagen in scleroderma.

In sclerodermal skin, the values for proline (Pro), hydroxyproline (Hyp) and hydroxylsine (Hyl) are lower than in normal skin. The molar ratio Hyp to Hyl is lowered. The molar ratio Pro to Hyp was found to be elevated, while that of Pro to Hyl was like that of normal skin. It was concluded that in slceroderma the hydroxylation of Pro to Hyp is incomplete, resulting in an abnormal collagen.

Collagen↗
PubMed1976

Micromethod for fractionation of acid mucopolysaccharides.

A new micromethod for fractionation of acid mucopolysaccharides based upon the use of different concentrations of HC1 to separate the complex of CPC with non-sulphated, monosulphated and polysulphated acid mucopolysaccharides (glycosaminoglycans) is presented. The method utilizes the different binding of the anionic macromolecules to the cationic compound cetyl pyridinium chloride. The method is simple and reproducible. The use of HC1 as eluent allows the exclusion of some steps required when salts are used for elution. Hexuronic acids are determined on the eluents.

Chondroitinases and Chondroitin Lyases↗
PubMed1976

Simplified method for determination of protocollagen proline hydroxylase.

Preparation of (14C) Pro labeled protocollagen and requirements for its hydroxylation by PPH was investigated. Protocollagen can be prepared by centrifugation of the biological material at 15.000 X g. Substances in current use, viz catalase, bovine serum albumin and dithiothreitol were found unnecessary under the hydroxylation conditions used. A decrease in PPH in the testis and skin of rats with increasing age was demonstrated.

Animals↗
PubMed1976

An assay for total hexosamine and a differential assay for glucosamine and galactosamine.

Two new procedures are presented for quantitative determination of glucosamine and galactosamine. One, which is proposed for total hexosamine, yields chromogens of equal intensity with equal concentration of glucosamine and galactosamine. There is addition of the correspondent chromogens when they are present in mixtures. The procedure is presented as a manual as well as an automated assay. The other procedure is a differential assay which allows the detection of galactosamine without interference by glucosamine. By the two procedures, the hexosamines present in acid mucopolysaccharides and/or glycoproteins can be determined.

Acetylgalactosamine↗
PubMed1976

Cortisol effect on collagen biosynthesis in embryonic explants and in vitro hydroxylation of protocollagen.

The effect of increasing doses of hydrocortisone acetate, hydrocortisone phosphoric acid complex, and hydrocortisone sodium succinate on collagen biosynthesis was assayed in two different systems. I. Explants of chicken embryo tibiae showed decreased biosynthesis of [14C]hydroxyproline and total and glycosylated [14C]hydroxylysine under the influence of high doses of hydrocortisone. With the lower doses of hydrocortisone acetate, no effect was noticed. The total uptake of the precursor amino acids followed patterns similar to those of collagen biosynthesis. II. Hydroxylation of [14C]proline labelled protocollagen by protocollagen proline hydroxylase was inhibited by high doses of hydrocortisone acetate, hydrocortisone phosphoric acid complex, and hydrocortisone sodium succinate. III. A decreased diffusion of collagen to the medium with increasing doses of hydrocortisone acetate, hydrocortisone phosphoric acid, and hydrocortisone sodium succinate was noticed. IV. No further hydroxylation of new-synthesized collagen was obtained under the influence of hydrocortisone phosphoric acid and hydrocortisone sodium succinate, when the undialyzable material was used as a substrate for protocollagen proline hydroxylase.

Animals↗
PubMed1976

Parallel studies on collagen hydroxyproline and hydroxylysine in human skin biopsies.

Studies on hydroxyproline and hydroxylysine, the two amino acids characteristic of collagen and related glycoproteins, were undertaken on biopsies of pathologic and clinically normal human skin. No statistically significant differences between clinically normal skin of mamma, thorax, axilla, femur, hip and sacral area were found. A decreased collagen content was seen in chronic pemphigus (bullous pemphigoid), amyloidosis, scleromyxedema and the edge of a leg ulcer. Determination of both amino acids is considered necessary to characterize alterations of collagen.

Adult↗
PubMed1975

A selective stain for mast cells.

A selective stain for mast cells in tissue sections is presented. The procedure is based on the resistance to destaining with absolute ethanol-acetic acid of the complex acid mucopolysaccharide-Toluidine Blue reinforced with ferrioxamine B.

Acetates↗