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Biomedical subjects

N Blumenkrantz

Publications and source records attributed to N Blumenkrantz.

At least 19 recordsLinked to original sources
PubMed1979

Effect of hydralazine and dihydralazine on connective tissue and binding to serum protein.

Hydralazine and dihydralazine, chelators of Fe2+, Fe3+ and Mn2+ ions, inhibited collagen biosynthesis in organ culture of chicken embryo tibiae. Both substances inhibited the in vitro hydroxylation of [14C]Pro-labelled protocollagen by protocollagen proline hydroxylase. A decreased incorporation of [14C]-D-glucosamine into glyco- and/or muco-proteins was found under the effect of the two drugs. Dihydralazine, a cationic compound, was bound to DNA and acid mucopolysaccharides (glycosaminoglycans), forming an insoluble complex. Both substances were bound to serum alpha 2-globulin. Subcutaneous injections of dihydralazine in rats produced a local as well as a general toxic effect.

Animals↗
PubMed1979

Urinary proline to hydroxyproline ratio varies with age.

Urinary excretion of proline and hydroxyproline was studied in five groups of subjects, viz. controls, pituitary dwarfs, familial dwarfs, patients with fibrodysplasia ossificans progressive and patients with generalized scleroderma. The ratio Pro/Hyp in the urinary fraction precipitated with 5 parts of acetone (1 + 5 fraction) was close to one in children and youngsters in all the groups, while in adults it was higher than two. Total Pro/Hyp does not give an accurate index of age.

Adolescent↗
PubMed1978

Fibrodysplasia ossificans progressiva. Biochemical changes in blood serum, urine, skin, bone, and ectopic ossification.

Increased urinary output of total hydroxyproline, hydroxylysine and uronic acid was found in two patients suffering from fibrodysplasia ossificans progressiva. Before treatment of one of the patients, the high molecular weight peptide fraction deriving from newly synthesised collagen was particularly increased. Treatment with disodium etidronate (diphosphonate) reduced the values. The urinary values of sodium, potassium and calcium were also depressed during treatment, and, in both patients, serum phosphate was high, while serum calcium was normal. The hydroxyproline and hydroxylysine contents in skin and bone of FOP patients did not differ from controls, while ectopic ossifications showed a considerable increase in hydroxylysine in relation to normal bone.

Adolescent↗
PubMed1978

Effects of some connective-tissue active drugs on protocollagen proline hydroxylase activity.

The effect on protocollagen proline hydroxylase of drugs reported to be capable of inducing the lupus erythematosus syndrome and in some way acting on connective tissue and inflammation was studied in an in vitro system for the hydroxylation of 14C-Pro-labelled protocollagen. Some derivatives were also studied. It was found that benzoic acid and phenothiazine derivatives, hydroxyphenols, (+)catechin, beta-amino propionitrile, certain B vitamins, dihydrazinophthalazine, cysteine and dimethylcysteine were inhibitors of PPH. The chelation of Fe2+ions by the compounds mentioned is suggested to be essential.

Animals↗
PubMed1978

Effect of (+)catechin on connective tissue.

The effect of (+)catechin on connective tissue was studied in organ cultures of chick embryo tibiae and after in vivo injection in rats and mice. Collagen biosynthesis and hydroxylation of 14C-Pro-labelled protocollagen in vitro by protocollagen proline hydroxylase (PPH) were inhibited. In vivo, a slight decrease in the biosynthesis of collagen and in the PPH activity in skin of rats and mice was noticed as an effect of (+)catechin. No effect of the drug was observed on the incorporation of 14C-D-glucosamine by chick embryo tibiae. Increased urinary excretion of acid mucopolysaccharide metabolites by the mice injected with (+)catechin was observed.

Aminopropionitrile↗
PubMed1978

Abnormal skin collagen in scleroderma.

A significant decrease in the content of hydroxyproline and hydroxylysine was found in the skin of patients with generalized scleroderma (acrosclerosis), the lowering of Hyp being more marked than that of Hyl. The production of an abnormal collagen or a change from one collagen type to another is suggested to take place.

Collagen↗
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↗