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Biomedical subjects

Y Yue

Publications and source records attributed to Y Yue.

63 records · Page 4Linked to original sources
PubMed1994

[Detection of islet cell antibodies by using avidin-biotin-peroxidase complex technique].

Autoimmune mechanisms may be involved in the pathogenesis of insulin dependent diabetes mellitus (IDDM). Multiple autoantibodies have been detected in patients with IDDM. Islet cell antibodies (ICA), complent-fixing islet cell antibodies (CF-ICA) and antibodies to an islet cell protein 64000 M(r) (64K antibodies) have been regarded as immunological markers in IDDM. ICA detection with immunohistochemistry requires fresh normal human pancreas (blood group O) which provides an antigen for measuring ICA in serum samples. In the present study ICA detection was first carried out by using avidin-biotin-peroxidase complex technique (ABC) method and paraffin sections of human pancreas (blood group O), Serum samples were obtained from 17 patients with IDDM, 20 with NIDDM and 20 without diabetes mellitus. In patients with IDDM, ICA were detected in 9 of the 17 (52.94%) while none of the patients with NIDDM and without diabetes mellitus were ICA positive. In comparison with other methods, the present one is more reliable, sensitive, specific and simple. Therefore, it may be widely used for ICA detection in clinical practice.

Adolescent↗
PubMed1992

[Epilepsy and hypohaptoglobinemia].

The serum haptoglobin (Hp) of 24 patients with familial epilepsy and 21 relatives of them, as well as 21 patients with secondary epilepsy was determined by the method of linear concentration gradient (4-22%) polyacrylamide gel electrophoresis. The mean value of their serum Hp was significantly reduced to 54.83% (P less than 0.001), 76.48% (P less than 0.01) and 74.91% (P less than 0.01) of that of the control (109.63 mgHb/dl, n = 201) respectively. The possible pathophysiological mechanism of the epileptic seizures and reduced serum Hp level was discussed briefly.

Epilepsy↗
PubMed1990

Lipogenesis stimulatory and inhibitory activities of the insulin mediators.

Incubating plasma membranes prepared from pig liver with varying concentrations of insulin (50-1000 microU/ml) resulted in the release of at least two insulin chemical mediators. One of them was fraction 1 of insulin mediator (M. W. 3700-4000 daltons) which had a significant lipogenesis-stimulating activity. The other was fraction 2 of insulin mediator (M. W. about 1000 daltons) which exhibited a lipogenesis-inhibitory activity. The ratio of yield between the two mediators produced from the membranes was not only dependent on the concentration but also on the potency of insulin and its analogs added. The result showed that there was more production of fraction 2 than fraction 1 with the inducer at low concentration (100 microU/ml), while the production of fraction 1 from the plasma membranes incubated with high concentration of insulin (300 microU/ml) was higher than fraction 2. On the other hand, insulin and its analogs which have different biological activities and receptor binding activities have been used to induce the insulin mediators. The results obtained were similar to those mentioned above. This suggested that the generation of the mediators was dependent on the biological potences but not the binding activities.

Animals↗
PubMed1988

Adenylate cyclase-modulating mediators of insulin.

Plasma membranes prepared from pig liver incubated with insulin (50-300 microU/ml) resulted in the release of at least two insulin chemical mediators. They appeared to modulate the activity of adenylate cyclase in liver plasma membranes of pig. One of them was fraction 1 of insulin mediator (M. W. about 3700-4000 dalton) which markedly stimulated the activity of the enzyme, the other was fraction 2 of insulin mediator (M. W. about 1000 dalton) which inhibited the enzyme activity. The results showed that the inhibitor of fraction 2 generated was significantly higher than that of fraction 1 when the membranes were incubated with insulin of low concentration (50-100 microU/ml). On the other hand, the generation of stimulator of fraction 1 from plasma membranes incubated with insulin of high concentration (200 microU/ml) was higher than that of fraction 2. So the ratio of yield between two mediators produced from the membranes was dependent on the concentration of insulin added. The results also showed that the effect of fraction 1 of insulin mediator on adenylate cyclase activity in liver cell plasma membranes was biphasic while fraction 2 of insulin mediator showed an inhibitory effect only even though it was at very high concentration. The results that both mediators combined with Gpp(NH)p and forskolin to affect the enzyme activity show that the action of insulin mediators likely resides in the GTP regulatory component of adenylate cyclase.

Adenylyl Cyclases↗
PubMed1987

The role of insulin mediators in regulation of cAMP and lipogenesis as well as in diabetes.

Plasma membranes prepared from pig, mouse and rat liver incubated with insulin resulted in the release of at least two insulin chemical mediators. These mediators, identified as fractions 1 and 3, were found to inhibit cAMP level in response to lipolytic hormone and forskolin and to enhance lipogenesis in adipocytes of rat. Fractions 1 and 3 have been estimated to have molecular weights of 3700-4000 and 1000-1500 dalton, respectively. This initial report will focus on fraction 1. Interestingly, liver membranes from diabetic animals were found not to release mediators in the presence of insulin. However, following in vivo treatment of diabetic animals with insulin, the liver membranes appeared to restore its ability in generating chemical mediators in response to insulin.

Adipose Tissue↗
PubMedDate not supplied

Crosslinkage of collagen by polyglycidyl ethers.

Calcification is the principal cause of failure of glutaraldehyde treated bioprosthetic heart valves. This article reports the crosslinkage of several polyglycidyl ethers. Calcification of yak pericardium with polyglycidyl ethers was significantly decreased compared with that crosslinked with glutaraldehyde. The process of calcification of crosslinked yak pericardium was studied using 21 day subdermal implants in rats. The uptake of calcium with ethane diglycidyl ether was reduced (0.57 +/- 0.19 vs 4.28 +/- 1.62 micrograms/mg) over that with glutaraldehyde. Four polyglycidyl ethers were developed and compared. The best compound for raising the shrinkage temperature was the shortest chain compound without steric hindrance. In the polyglycidyl ether process, a suitable amount of alcohol was necessary to promote crosslinking; the catalyst, 2, 4, 6 -tris (dimethyl aminomethyl) phenol (TDAMP) and salicylic acid, were not favorable for long-term treatment of tissues because of the unnecessarily deep dyeing of the tissue, in addition to raising the shrinkage temperature. Unlike glutaraldehyde treatment, which reacts with lysine, polyglycidyl ether treated tissues maintained flexibility of the pericardial tissue, while binding amino acids such as lysine, methionine, tyrosine, aspartic acid and glutamic acid. The authors conclude that the ethane diglycidyl ether process combined with formaldehyde would further raise the shrinkage temperature from 78 degrees C to 87.5 degrees C and sustain it above 80 degrees C. Reverse treatment was not as effective. Compared with glutaraldehyde, polyglycidyl ether treatment renders tissue more flexible, increases the thermal stability of collagen, and decreases the incidence of calcification in vivo.

Amino Acids↗