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Biomedical subjects

W W Li

Publications and source records attributed to W W Li.

At least 109 records · Page 6Linked to original sources
PubMed1986

Effects of alpha-momorcharin, beta-momorcharin and alpha-trichosanthin on lipogenesis and testicular and adrenal steroidogenesis in vitro and plasma-glucose levels in vivo.

The effects of alpha-momorcharin, beta-momorcharin and alpha-trichosanthin on lipogenesis in isolated rat adipocytes were examined. None of the three abortifacient proteins possessed lipogenic activity. The plant proteins did not affect the plasma-glucose level in fasting mice nor did they affect luteinizing hormone-induced testosterone production in isolated rat Leydig cells or corticotropin-induced corticosterone production in isolated rat adrenal decapsular cells by the end of a 2-h incubation period. The results suggest that the functions of adipocytes, adrenal decapsular cells, Leydig cells and pancreatic beta cells were not greatly affected after short-term exposure to the abortifacient proteins.

Abortifacient Agents, Nonsteroidal↗
PubMed1986

A steryl glycoside fraction with hemolytic activity from tubers of Momordica cochinchinensis.

A hemolytic fraction has been obtained from fresh tubers of Momordica cochinchinensis. The fraction was strongly adsorbed on DEAE-Sepharose CL6B. It did not stain with Coomassie brilliant blue in SDS-polyacrylamide gel electrophoresis and it gave no immunoprecipitin arcs in immunoelectrophoresis. The hemolytic activity of the fraction was resistant to heat and proteolytic enzymes. The behavior of the fraction in thin-layer chromatography and its positive reaction in Liebermann-Burchard test indicated that the hemolytic activity of the fraction can be attributed to a steryl glycoside(s).

Chromatography, Ion Exchange↗
PubMed1986

Insulin-like molecules in Momordica charantia seeds.

Decorticated Momordica charantia seeds were extracted and processed by a method which was developed originally for the purification of insect and annelid insulins. Essentially, the method entailed HCl--ethanol extraction, neutralization with NH4OH, gel filtration on Sephadex G-50, ion exchange chromatography on CM Sepharose CL-6B and desalting on Sephadex G-10. Of the seven fractions collected, three fractions were obtained with antilipolytic and lipogenic activities in isolated adipocytes and one fraction with only lipogenic activity. The data indicate that molecules with insulin-like bioactivity are present in Momordica charantia seeds.

Adipose Tissue↗
PubMed1986

Chemical and biological characterization of the galactose binding lectins from Trichosanthes kirilowii root tubers.

Three galactose binding isolectins have been isolated from Trichosanthes kirilowii root tubers. Two of the isolectins, TK-I and TK-II, are similar in many aspects including molecular weight, amino acid composition, NH2-terminal amino acid residue, blood group and carbohydrate specificities, immunodiffusion and immunoelectrophoretic behavior, hemagglutinating and insulinomimetic activities, and in possessing subunits with different molecular weights. Compared to TK-I and TK-II, lectin TK-III has a larger molecular weight, subunits with the same molecular weight, a single and distinctive NH2-terminal amino acid residue, a different isoelectric point and lower hemagglutinating activity. The three lectins share common antigenic determinants in their structures. beta-Linked terminal oligosaccharides containing D-galactose inhibit hemagglutination induced by the lectins with a higher potency than alpha-linked oligosaccharides. The lectins are non-mitogenic and did not inhibit the concanavalin-A induced mitogenic response of lymphocytes.

Adipose Tissue↗
PubMed1986

Isolation and characterization of a galactose binding lectin with insulinomimetic activities. From the seeds of the bitter gourd Momordica charantia (Family Cucurbitaceae).

A galactose binding lectin was isolated from the seeds of the bitter gourd Momordica charantia by delipidation with petroleum ether, extraction with phosphate buffered saline, ammonium sulfate precipitation and affinity chromatography on lactogel. The lectin had a molecular weight of 124,000 and approximately 5% carbohydrate content. The molecular weights of the individual subunits were 37,000, 35,000 and 33,000. The lectin exhibited potent hemagglutinating activity. In addition, it demonstrated antilipolytic and lipogenic activities in isolated rat adipocytes although it did not possess intrinsic lipolytic activity. The antilipolytic activity was susceptible to destruction by heat, trypsin, chymotrypsin, glutathione and galactose, indicating that the integrity of the protein moiety, the disulfide linkages, and galactose, which is the sugar specifically bound by the lectin, all play an important role in interaction with the adipocyte leading to an expression of this insulin-like activity.

Adipose Tissue↗
PubMed1986

A steryl glycoside fraction from Momordica charantia seeds with an inhibitory action on lipid metabolism in vitro.

A saponin fraction was isolated from Momordica charantia seeds by delipidation, saline extraction, ammonium sulfate precipitation, and extraction of the resulting supernatant with n-butanol. Thin-layer chromatography, in the upper phase of the n-butanol--ethyl acetate--water (4:1:5, by volume) system on plastic sheets coated with silica gel 60 F254, revealed the presence of a single spot after spraying with 10% sulfuric acid. The lack of contamination of the saponin preparation with proteins was judged by the absence of protein bands in sodium dodecyl sulfate--polyacrylamide gel electrophoresis, agarose electrophoresis and agarose diffusion, and by the absence of an absorption maximum around 278 nm. The saponin acted as a noncompetitive inhibitor of corticotropin, glucagon, and epinephrine in lipolysis in isolated rat adipocytes, and it also antagonized dibutyryl cAMP induced lipolysis. The antilipolytic activity was resistant to heat, trypsin, chymotrypsin, pronase, and glutathione, in keeping with the chemical nature of saponin. Incorporation of [3-3H]glucose into lipid was inhibited. Adipocyte viability and ATP content were not affected by the saponin, suggesting that its inhibitory effects on lipolysis and lipogenesis were not due to an adverse effect on cell viability.

Adipose Tissue↗
PubMed1986

The functional activities of the pigment epithelium in aging.

The phagocytic ability of the pigment cells of the retinae of mice of different ages was studied in 2-, 5-, 7-, and 9-month-old animals. A decrease in activity was evident as the animals aged. There was also a difference in the response pattern of enzymes (as demonstrated in the case of alkaline phosphatase) in the first 35 h after latex bead injection.

Aging↗
PubMed1986

Early patterns of neuronal degeneration in the retina of the goldfish after optic nerve sectioning.

The early patterns of retinal degeneration were studied in the goldfish after optic nerve sectioning by l.m. and e.m. Beginning on the 2nd postsurgical day there was an initial degeneration of neurons in the ganglion cell and inner nuclear layers of the central retina. Massive ganglion cell degeneration in the whole retina (60%) as well as degeneration of neurons in inner and outer nuclear layer of the peripheral retina was evident around the 7th postsurgical day. The early degenerating cells appeared to be cones and cone bipolars.

Animals↗
PubMed1985

Horseshoe crab (Limulus polyphemus) lectin but not garden snail (Helix pomatia) lectin elicits insulin-like activities in vitro.

Lectins from the horseshoe crab (Limulus polyphemus) and the garden snail (Helix pomatia) were tested for insulinomimetic activities in isolated rat epididymal adipocytes. The sialic acid binding horseshoe crab lectin suppressed epinephrine-induced lipolysis and augmented lipogenesis from D-[3-3H]-glucose while the N-acetylgalactosamine binding snail lectin was inactive. The results suggest that the insulin receptor on rat adipocytes contains sialic acid in its carbohydrate moiety but does not possess non-reducing alpha-D-galactopyranosyl or 2-acetamido-2-deoxy-alpha-D-galactopyranosyl end groups.

Adipose Tissue↗
PubMed1985

Effect of Trichosanthes kirilowii lectin on lipolysis and lipogenesis in isolated rat and hamster adipocytes.

The galactose-binding lectin from the Chinese herb Trichosanthes kirilowii (Tianhuafen) stimulated the incorporation of D-[3-3H]glucose into lipids in isolated rat epididymal adipocytes. The lectin, however, did not inhibit lipolysis induced by either epinephrine or corticotropin in these adipocytes. Similarly, it did not suppress corticotropin-induced lipolysis in isolated hamster adipocytes. At a dose that did not stimulate lipolysis on its own, the lectin slightly potentiated the lipolytic effects of corticotropin and epinephrine. These findings are discussed in relation to previous observations on other galactose-binding lectins.

Adipose Tissue↗
PubMed1980

Intraocular invasion by papillary squamous cell carcinoma of the conjunctiva.

Two patients with incompletely excised invasive papillary squamous cell carcinoma of the corneoscleral limbal conjunctiva had subtle clinical signs suggesting incomplete transmural extension or localized intraocular tumor invasion. We attempted a wide en bloc resection procedure in each case. Histopathologic examination disclosed that the surgical margins were involved with tumor cells and the eyes were subsequently enucleated. The enucleated eyes disclosed more extensive microscopic intraocular involvement than had been anticipated.

Adult↗