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Y L Sun

Publications and source records attributed to Y L Sun.

56 records · Page 4Linked to original sources

In vitro and in vivo evaluation of microencapsulated porcine islets.

To provide a plentiful supply of pancreatic islets for future clinical transplants into diabetic patients, the authors have developed a simple and consistent method of isolation of porcine islets. Both in vitro and in vivo studies demonstrated that the islets were viable and functional. Xenotransplants of 1.5 x 10(3) - 2.5 x 10(3) of microencapsulated porcine islets into diabetic mice resulted in restoration of normoglycemia in 13 of 18 experimental animals for up to 10 months. A xenograft of 50 x 10(3) microencapsulated porcine islets into a spontaneously diabetic monkey normalized hyperglycemia for more than 150 days. This experiment indicated that the transplantation of encapsulated porcine islets has great potential as a clinical treatment in diabetes mellitus.

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[The stress gene in hypertension].

Thermosensitivity has been demonstrated in hypertensive rats and mice, and hypertension is frequent in hyperthermia-susceptible pigs. We have demonstrated that thermosensitivity segregates with hypertension in mice as a recessive trait in a single locus termed Tms. Since thermosensitivity can be demonstrated in cells obtained from neonatal hypertensive animals and persists after several passages in culture, it was of interest to study its cellular determinants. We undertook studies of candidate genes of cellular thermosensitivity, hsp70 being the major heat stress gene. First, we have observed an enhanced hsp70 mRNA accumulation in the hypertensive rat, mouse and human after heat shock of the whole animal, of its isolated organs or cultured cells. This increased accumulation of hsp70 mRNA in hypertension is due to its increased transcriptional rate. A restriction fragment length polymorphism (RFLP) of hsp70 was documented in hypertensive rats, which allowed the study of the segregation of this locus with hypertension in recombinant inbred strains of rats. At least one copy of hsp70 has been localized in RT1, the major histocompatibility complex of the rat, with polymorphism demonstrated with BamHI outside of the coding region of hsp70. This polymorphism segregates with 15 mmHg of systolic blood pressure. More recently, our studies led us to identify a polymorphism in another heat stress gene, hsp27. This polymorphism has been identified by PCR SSCP and is located in the 3' region, close to the termination translation codon.(ABSTRACT TRUNCATED AT 250 WORDS)

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