Biomedical subjects
Publications and source records attributed to N Di Ferrante.
Abnormally soluble collagen is synthesized in vitro not only by skin fibroblasts of Marfan patients but also by those of patients with Ehlers-Danlos type V and cutis laxa. The excessive solubility of collagen is corrected by the addition to the culture medium of a synthetic flavonoid, (+)- catechin.
Human N-acetylgalactosamine-6-sulfate sulfatase (6-sulfatase) activity is measured by using as a substrate a sulfated tetrasaccharide obtained by digesting purified chondroitin-6-sulfate (C-6-S) with testicular hyaluronidase. The amount of inorganic sulfate released is measured turbidimetrically. The enzyme from human kidney has a pH optimum of 4.8; its activity is augmented by low levels of NaCl and inhibited by phosphate and high levels of NaCl. Free glucuronate, acetylgalactosamine, inorganic sulfate, polymeric C-6-S, or tetrasaccharide obtained from chondroitin-4-sulfate do not affect the enzyme activity. The method may be used for the diagnosis of Morquio disease since extracts of Morquio fibroblasts are devoid of 6-sulfatase activity.
(+)--Cyanidanol, a water-soluble flavonoid, when added to cultured skin fibroblasts of a patient with I-cell disease raised the intracellular concentration of beta-galactosidase but did not affect the distribution of arylsulfatase. A, alpha-mannosidase or beta-glucuronidase. The elevated accumulation of 35SO4 by I-cell, Hunter and Maroteaux-Lamy fibroblasts was decreased by the addition of (+)--cyanidanol to the culture medium, but the degradation of previously labeled, intracellular glycosaminoglycans was not. It is concluded that (+)--cyanidanol does not produce a biochemical correction of the enzymic abnormalities existing in I-cell fibroblasts.
A compound, isolated from acid hydrolysates of urine samples from normal children, characterized as 3,6-anhydroglucosamine by chromatography on a cation exchange resin and by gas-liquid chromatography, could not be detected in hydrolyses of urine from Morquio patients.
Explore the source record for details and available documents.
The dodecasaccharide obtained by treating dermatan sulfate with testicular hyaluronidase, chondroitinase AC, and beta-glucuronidase was incubated with diluted, normal human serum at pH 4.5 or 7.0 followed by chondro-4-sulfatase at pH 7.0. Analyses of the reaction products indicate release of hexosamine but not further degradation of the substrate. It is concluded that normal human serum possesses an exo-beta-N-acetylhexosaminidase active on dermatan sulfate.
Two maternal cousins affected by the X-linked form of Ehlers-Danlos syndrome have been observed. Both had congenital heart disease, "floppy valve syndrome", hernias, short stature, stretchable skin and moderate joint hypermobility. Both excreted normal amounts of urinary glycosaminoglycans, almost entirely represented by dermatan sulfate, whose degradation appeared to be inadequate. They also excreted large amounts of hydroxylysine glycosides and L-valyl-proline, considered to be products of degradation of collagen and elastin, respectively. Cultured skin fibroblasts of the propositus synthesized excessively soluble collagen and had a low lysyl oxidase activity. These findings suggest that the increased degradation of structural proteins may be secondary to the defective cross-linking processes caused by the enzymic defect. Addition of (+) catechin, a flavonoid, to the propositus's cultured fibroblasts decreased the abnormal solubility of their collagen.
Explore the source record for details and available documents.
Skin fibroblasts from three obligated and one potential heterozygotes for the Hunter gene displayed abnormal metabolism of glycosaminoglycans four to six weeks after rapid freezing in liquid nitrogen. The technique seems to be useful for the identification of Hunter carriers, especially when the degradation of 35SO4-labeled, intracellular glycosaminoglycans, rather than the uptake of 35SO4, is measured.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effects of the administration of normal human plasma to patients affected by mucopolysaccharidoses I and II (Hurler's and Hunter's syndromes) have been evaluated. The infusion was followed by a decreased urinary excretion of relatively large molecular weight glycosaminoglycans and by an increased excretion of their products of degradation. Among the latter, products of the degradation of dermatan sulfate and heparan sulfate could be demonstrated. The results indicate that normal human plasma may contain those "factors" that are involved in the normal degradation of dermatan sulfate and heparan sulfate, that are missing in the diseased states.