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Y Ju

Publications and source records attributed to Y Ju.

18 recordsLinked to original sources
PubMed2005

Greater capillary-fiber interface per fiber mitochondrial volume in skeletal muscles of old rats.

The objective was to examine whether muscle structural capacity for O2 flux (i.e., capillary-to-fiber surface ratio) relative to fiber mitochondrial volume deteriorates with the muscle atrophy of aging in predominantly slow- (soleus, S) and fast-twitch (extensor digitorum longus, EDL) muscles of old (24 mo) and very old (35 mo) F344BN rats compared with adult (12 mo old). Wet muscle mass decreased 29% (196 +/- 4 to 139 +/- 5 mg) in S and 22% (192 +/- 3 to 150 +/- 3 mg) in EDL between 12 and 35 mo of age, without decline in body mass. Capillary density increased 65% (1,387 +/- 54 to 2,291 +/- 238 mm(-2)) in S and 130% (964 +/- 95 to 2,216 +/- 311 mm(-2)) in EDL, because of the muscle fiber atrophy, whereas capillary per fiber number remained unchanged. Altered capillary geometry, i.e., lesser contribution of tortuosity and branching to capillary length, was found in S at 35 compared with 12 and 24 mo, and not in EDL. Accounting for capillary geometry revealed 55% (1,776 +/- 78 to 2,750 +/- 271 mm(-2)) and 113% (1,194 +/- 112 to 2,540 +/- 343 mm(-2)) increases in capillary length-to-fiber volume ratio between 12 and 35 mo of age in S and EDL, respectively. Fiber mitochondrial volume density was unchanged over the same period, causing mitochondrial volume per micrometer fiber length to decrease in proportion to the fiber atrophy in both muscles. As a result of the smaller fiber mitochondrial volume in the face of the unchanged capillary-to-fiber number ratio, capillary-to-fiber surface ratio relative to fiber mitochondrial volume not only did not deteriorate, but in fact increased twofold in both muscles between 12 and 35 mo of age, independent of their different fiber type.

Aging↗
PubMed2004

Synthesis, in vitro anticancer evaluation, and interference with cell cycle progression of N-phosphoamino acid esters of zidovudine and stavudine.

A series of N-diisopropylphosphoryl (DIPP) L-amino acid ester prodrugs of zidovudine (AZT) (3a-3e) and stavudine (d4T) (4a-4e) has been prepared. The activity of these compounds against MCF-7 cells (human pleural effusion breast adenocarcinoma cell line) and K562 cells (human chronic myeloid leukemia (CML) cell line) was evaluated. In difference from that of AZT amino acid phosphoramidates, the alophatic amino acid esters of AZT were found to be more cytotoxic than the aromatic analogues toward MCF-7 cell. Two DIPP-L-amino acid esters of d4T 4b (CC50 = 83 microM) and 4c (CC50 = 182 microM) were found to be more cytotoxic than the parent drug toward K562 cells. MCF-7 and K562 cell cycle disturbance was investigated showing detectable blockade in the S phase when exposed to biologically active AZT, 3a, 3b, 3c, 4b and 4c, indicating that they inhibit cell growth by blocking cell cycle progression. Together with previous reports, present findings suggest that anti-breast cancer activity of AZT may be due to hamper DNA synthesis.

Antineoplastic Agents↗
PubMed2001

Cytotoxic coumarins and lignans from extracts of the northern prickly ash (Zanthoxylum americanum).

Four pyranocoumarins; dipetaline, alloxanthoxyletin, xanthoxyletin and xanthyletin; and two lignans; sesamin and asarinin were isolated from the northern prickly ash, Zanthoxylum americanum. To varying degrees, all inhibited the incorporation of tritiated thymidine into human leukaemia (HL-60) cells. Dipetaline was the most active with an IC(50) of 0.68 ppm, followed by alloxanthoxyletin (1.31 ppm), sesamin (2.71 ppm), asarinin (4.12 ppm), xanthoxyletin (3.48 ppm) and xanthylletin (3.84 ppm).

Antineoplastic Agents↗
PubMed2001

Effects of two saponins extracted from the polygonatum Zanlanscianense pamp on the human leukemia (HL-60) cells.

Two saponins, methyl protodioscin and dioscin, were extracted from the root of Polygonatum Zanlanscianense Pamp. One of them, dioscin exerted significant inhibitory effects on the growth of the human leukemia cell HL-60, inducing differentiation and apoptosis. HL60 cells were induced mainly along the granulocytic lineage. In addition, we have found that dioscin affects many cancer cells. These studies may have important significance in treating related cancers.

Apoptosis↗
PubMed2001

Clinical features of diffuse axonal injury.

OBJECTIVE: To analyze the mechanism of diffuse axonal injury (DAI) and study the relationship between DAI and brain concussion, brain contusion, and primary brain stem injury. METHODS: The clinical data and iconographic characteristics of 56 patients with DAI were analyzed retrospectively. RESULTS: Traffic accidents were the main cause of DAI. Among t he 56 cases, 34 were injured for at least twice, and 71.43% of the patients were complicated with contusion. CONCLUSIONS: It is considered that DAI is a common pattern of primary brain injury, which is often underestimated. And DAI includes cerebral concussion and primary brain injury, and is often complicated by cerebral cortex contusion. Therefore, it is very simple and practical to divide primary brain injuries into local and diffuse injuries.

Adolescent↗
PubMed1996

Simultaneous formation of peptides and nucleotides from N-phosphothreonine.

An intramolecular mutual activation between a phosphoryl group and carboxyl group results in the simultaneous formation of nucleotides and peptides by the reaction of nucleosides with N-(O,O-diisopropyl)phosphothreonine in anhydrous pyridine. These results suggest pathways for the simultaneous prebiotic synthesis of peptides and oligonucleotides.

Chromatography, High Pressure Liquid↗
PubMed1994

Monocyte chemoattractant protein 1 (MCP-1) expression occurs in toxic rat liver injury and human liver disease.

Considerable evidence suggests that monocytes/macrophages play a crucial role in the process of liver injury and repair. Recent investigations have focused on the function of various macrophage-produced cytokines in liver disease. Much is still unknown, however, about the mechanism of macrophage recruitment and activation during liver disease. To further define this process, the gene expression of the monocyte chemoattractant monocyte chemoattractant protein 1 (MCP-1) was examined in animal and human liver disease. MCP-1 mRNA was not found in normal rat liver by Northern blot analysis. After single-dose treatments with the hepatotoxins carbon tetrachloride and galactosamine, MCP-1 mRNA was detectable beginning at 2 and 4 h after treatment, respectively, and was expressed continuously until 60-72 h. During chronic carbon tetrachloride administration, MCP-1 mRNA levels were elevated for the entire 10 weeks of treatment with peak levels of expression occurring early (weeks 1-3) and late (weeks 8-10) in this model. Isolated liver cell fractions from rats treated for 3 weeks with carbon tetrachloride revealed the major cellular source of MCP-1 mRNA to be fat-storing or Ito cells, with some expression occurring in the endothelial cell fraction. Studies of potential inducers of hepatic MCP-1 expression showed that lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-1 alpha and beta treatments all led to MCP-1 expression. Finally, studies of human liver samples revealed MCP-1 gene expression in nondiseased liver and greatly increased levels in livers from patients with fulminant hepatic failure. These data implicate MCP-1 from fat-storing cells as a modulator of the process of liver injury and further support a role for MCP-1 in the pathogenesis of human disease.

Animals↗
PubMed1994

Steroidal saponins from Smilax menispermoidea and S. lebrunii.

Three new (25S)spirost-5-en-3 beta,17 alpha,27-triol glycosides were isolated from the rhizomes and roots of Smilax menispermoidea and S. lebrunii. Their structures were elucidated by means of spectroscopic and chemical methods. Several known saponins were also isolated and identified.

Carbohydrate Sequence↗
PubMed1994

Facilitated nuclear transport of calmodulin in tissue culture cells.

Calmodulin (CaM) potentiates Ca(2+)-dependent signaling pathways in both the cytoplasm and nucleus. We have investigated the mechanism of CaM nuclear transport using tissue culture cell microinjection and a permeabilized cell import assay. The inhibition of CaM import by the translocation inhibitor wheat germ agglutinin (WGA) and by chilling, indicates that CaM import is facilitated, but because ATP depletion does not affect CaM import, the mechanism does not appear to be active. Chilling and WGA arrest persist in ATP-depleted cells, indicating that CaM is not retained in the cytoplasm by an ATP-dependent mechanism. In permeabilized cells, both Ca(2+)-CaM and Ca(2+)-free CaM are sensitive to extract-dependent WGA and chilling import inhibition. Titration experiments in microinjected and permeabilized cells indicate that a saturable cytosolic factor(s) mediates chilling and WGA arrest.

Adenosine Triphosphate↗
PubMed1994

Lipopolysaccharide-neutralizing antibody reduces hepatocyte injury from acute hepatotoxin administration.

Endogenous lipopolysaccharide has been implicated as a cofactor in the hepatocellular injury and death resulting from toxic liver injury. To prevent this lipopolysaccharide-induced injury and to further understand the mechanism of this effect, an anti-lipopolysaccharide antibody was administered to rats in which toxic hepatocellular injury was induced. Rats were given the hepatotoxin galactosamine together with an isotypic control antibody B55 or the anti-lipopolysaccharide antibody E5. E5 treatment resulted in reductions of serum AST levels of 43% at 36 hr (p < 0.02) and 60% at 48 hr (NS) after galactosamine administration. These decreases in AST values were accompanied by diminished histological evidence of injury and inflammation. In carbon tetrachloride-induced liver injury, E5 similarly reduced serum AST levels at 36 and 48 hr by 47% (p < 0.04) and 54% (p < 0.03), respectively. E5 treatment was equally effective in reducing AST levels 48 hr after administration of carbon tetrachloride, whether the initial dose of antibody was given 1 hr before or 3 or 6 hr after the administration of this toxin. To understand the mechanism of this E5 effect, the activation of the toxic cytokine tumor necrosis factor-alpha and the chemotactic cytokine monocyte chemoattractant protein 1 was examined by Northern-blot analysis of RNA from rat livers after galactosamine-induced injury and treatment with B55 or E5. Despite E5's efficacy in reducing hepatocellular damage, E5 treatment did not affect the timing or magnitude of tumor necrosis factor-alpha or monocyte chemoattractant protein 1 activation during galactosamine-induced injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Minor steroidal glycosides from the roots of Smilax lebrunii.

Three new minor steroidal saponins, (25R) 5 alpha-spirostan-3 beta-o1-6-one-3-O-[alpha-L-arabinopyranosyl(1-4)-beta-D- glucopyranoside, (25S) spirost-5-en-3 beta, 27-diol-3-O-[alpha-L-arabinopyranosyl (1-6)]-beta-D-glucopyranoside, and (25S) spirost-5-en-3 beta, 17 alpha, 27-triol-3-O-[alpha-L-arabinopyranosyl (1-6)]-beta-D-glaucopyranoside, were isolated from the root of Similax lebrunii, in addition to two known steroidal glycosides. Their structures were elucidated on the basis of chemical and spectral methods.

Carbohydrate Sequence↗
PubMed1992

Steroidal saponins from the rhizomes of Smilax menispermoidea.

Four steroidal saponins were isolated from the dried rhizomes of Smilax menispermoidea. One of them is new and its structure was established as (25S)spirost-5-en-3 beta,17 alpha-triol-3-O-[alpha-L-rhamnopyranosyl(1----2)] [alhpa-L-rhamnopyranosyl(1----4)]-beta-D-glucopyranoside using spectrometry and chemical methods, as well as comparison with three known steroidal saponins, dioscin, methyl protodioscin and pseudoprotodioscin.

Carbohydrate Sequence↗
PubMed1992

Steroidal saponins from Smilax lebrunii.

Two new steroidal saponins, (25 R)-spirostan-3 beta-ol-6-one-3-O-[alpha-L-arabinopyranosyl (1----6)]-beta-D-glucopyranoside and (25 R)-spirostan-3 beta-ol-6-one-3-O-[beta-D-glucopyranosyl(1---4)] [alpha-L-arabinopyranosyl(1----6)]-beta-glucopyranoside, were isolated from the rhizomes of Smilax lebrunii. Their structures have been established by chemical and spectral methods.

Carbohydrate Sequence↗
PubMed1990

Flavonoids as superoxide scavengers and antioxidants.

The superoxide anions scavenging activity and antioxidation of seven flavonoids--quercetin, rutin, morin, acacetin, hispidulin, hesperidin, and naringin--were studied. The superoxide anions were generated in a phenazin methosulphate-NADH system and were assayed by reduction of nitroblue tetrazolium. The scavenging activity ranked: rutin was the strongest, and quercetin and naringin the second, while morin and hispidulin were very weak. The concentration values yielding 50% inhibition of lipid peroxidation in mouse liver homogenate were in order of 10(-6) M for quercetin, rutin, and morin; and of 10(-5) M for acacetin and hispidulin, while naringin and hesperidin had no antioxidative action. In comparison with the antioxidative and scavenging activities of flavonoids, there are no correlations.

Animals↗