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Biomedical subjects

H B Nader

Publications and source records attributed to H B Nader.

At least 109 records · Page 6Linked to original sources
PubMed1982

Selective appearance of heparin in mammalian tissues during development.

The distribution of heparin in tissues of bovine and porcine fetuses of different ages as well as in the adult animals is reported. Heparin is present almost exclusively in the hematopoietic and lymphoid tissues of fetuses (spleen, liver, thymus and lymph nodes), whereas ileum, skin and lung besides lymph nodes and bovine thymus are the heparin-rich tissues in adult animals. The small amount of heparin in fetal tissues, its decrease in porcine liver and spleen, its appearance in skin, ileum and lung, tissues directly exposed to the environment after birth, its preferential localization at the maternal side of the placenta together with other data led to the suggestion that heparin may be involved with defense mechanisms.

Aging↗
PubMed1982

Pharmacological activities of heparins obtained from different tissues: enrichment of heparin fractions with high lipoprotein lipase, antihemolytic and anticoagulant activities by molecular sieving and antithrombin III affinity chromatography.

The pharmacological activities of 14 heparins prepared from bovine and hog tissues and heparin fractions obtained by molecular sieving on sephacryl S-200 and antithrombin III affinity chromatography are reported. Two groups of heparins can be distinguished regarding the lipoprotein lipase releasing activity (LPL) and the activated partial thromboplastin time (APTT). Heparins prepared from liver, lung, pancreas and thymus have a ratio of LPL/APTT of 3.6, whereas heparins prepared from placenta and intestine show a ratio of only 2.1. The heparin APTT, LPL, antihemolytic, antifactor Xa and anticoagulant activities were partially resolved by fractionation on Sephacryl S-200 chromatography and antithrombin III affinity chromatography. These results suggest the presence of a mixture of heparins with different pharmacological activities in a commercial preparation.

Animals↗
PubMed1982

Differences in sulfated glycosaminoglycans composition of the gastrointestinal mucosa.

Sulfated glycosaminoglycan (SGAG) composition of normal mucosa of esophagus, gastric body, antrum, duodenum, jejunum and rectum is reported. Each region examined may be defined by specific sulfated glycosaminoglycan distributions showing variations in relative proportions and total amount of heparan sulfate, dermatan sulfate and chondroitin 4, 6-sulfate. The results are discussed in the light of a recent proposal regarding the role of these compounds in cell-cell recognition and stimulation of cell division. The methodology made it possible to detect sulfated glycosaminoglycans from small amounts of tissue obtained by endoscopic biopsies.

Biopsy↗
PubMed1980

Glycosaminoglycans of some mouse mastocytomas.

The glycosaminoglycan fractions of four murine mastocytomas (AB-CBF1-MCT-1, AB-CXBG-MCT-1, AB-CXBI-MCT-1, and Furth), were isolated and characterized using microelectrophoresis, degradation with specific mucopolysaccharidases, paper chromatography and, in some instances, ion-exchange chromatography. Intramuscular and ascites tumors and tumors cultured in vitro were used. The glycosaminoglycans were labeled with [35S]sulfate and , in a few instances, with D-[6-3H]glucosamine. The glycosaminoglycan fraction obtained from the AB-CBF1-MCT-1 mastocytoma cultured in vitro consisted predominantly of dermatan sulfate-like material. On the other hand, the major components of the glycosaminoglycan fractions of the AB-CXBG-MCT-1 and AB-CXBI-MCT-1 and Furth tumors were observed to behave like heparin or heparan sulfate. In most of the mastocytoma samples examined, chondroitin 4-sulfate-like components were found to be present in smaller amounts, even in samples derived from tumor cells cultured in vitro. A component exhibiting a keratan sulfate-like behavior was detected in fractions obtained from the solid CXBG, CXBI and Furth tumors.

Animals↗
PubMed1980

Selective distribution of the heparin in mammals: conspicuous presence of heparin in lymphoid tissues.

The systematic study on the distribution of heparin in 12 tissues of eight mammalian species is reported. It is shown that heparin varies from 1 microgram/g of dry tissue in cat liver up to 1000 micrograms/g of dry tissue in bovine ileum. Heparin was present in relatively high amounts in lung, ileum and skin, of most of the species analysed. It was also observed that heparin was conspicuously present in high amounts in thymus and lymph nodes of all the species except for rabbits. Conversely, heparin was not detected in brains of all the species and also in none of the rabbit tissues. Based on this characteristic distribution the possible physiological role of heparin is discussed.

Animals↗
PubMed1979

Chemistry of heparitin sulfate and heparin from normal tissues and from patients with Hunter syndrome.

Some structural features of heparitin sulfate excreted by patients with Hunter syndrome are described. It is shown, with the aid of heparitinases and heparinase from Flavobacterium heparinum, that the Hunter heparitin sulfate is a very complex structure composed of nine different disaccharide units containing regions akin to normal heparitin sulfate and regions akin the heparin. Two-thirds of the iduronic acid residues of Hunter heparitin sulfate are devoid of sulfate, contrasting with heparin in which most of the iduronic acid residues are sulfated. The isolation and characterization of the non-reducing ends of heparin and of the heparitin sulfates is also described. Based on these results the specificity of the heparinase and heparitinases as well as the biosynthesis of iduronic acid-containing heparin-like compounds is discussed.

Chemical Phenomena↗
PubMed1976

On the structure of heparitin sulfates. Analyses of the products formed from heparitin sulfates by two heparitinases and a heparinase from Flavobacterium heparinum.

The analyses of the products formed from heparitin sulfates by the action of two heparitinases and a heparinase from Flavorbacterium heparinum is reported. Heparitin sulfates A and B are degraded by heparitinase I yielding two disaccharides, one of them composed of N-acetylucosamine and an unsaturated uronic, joined by alpha(1 lead to 4) linkage, and the other, with the same composition but with an O-sulfate at the hexosamine moiety. A third disaccharide is also formed from heparitin sulfate B, by the action of the same enzyme, composed of glucosamine N-sulfate and an unsaturated uronic acid joined probably by alpha(1 lead to 4) linkage. Besides these three disaccharides, heparitin sulfate B yields, by the action of heparitinase I, an oligosaccharide (with an average molecular weight of 6000) which is completely degraded by the heparitinase II yielding a disaccharide composed of glucosamine 2,6-disulfate and unsaturated uronic acid. All the disaccharides are further degraded by alpha-glycuronidase from Flavobacterium heparinum yielding the respective monosaccharides. Based on these and other analyses the possible structures of the heparitin sulfates are proposed.

Acetylglucosamine↗
PubMed1975

Electrofocusing of heparin: Presence of 21 monomeric and dimeric molecular species in heparin preparations.

Electrofocusing of heparins and subsequent polyacrylamide gel electrophoresis has shown that two types of heparins are present in different tissues. One of the types (from beef lung tissues) gives only a single band in agarose gel electrophoresis and 21 molecular species after electrofocusing and polyacrylamide gel electrophoresis. The other type of heparin (from pork intestinal mucosa) gives two bands in agarose gel electrophoresis and 42 molecular species after electrofocusing and polyacrylamide. Ascorbic acid treatment of the pork intestinal mucosa heparin reduced the number of molecular species to 21. A suggestion is made that some heparins exist as monomeric or dimeric molecular species forming single or double helixes.

Animals↗