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Y Huang

Publications and source records attributed to Y Huang.

At least 523 records · Page 29Linked to original sources
PubMed1999

Antitumor effects of an interferon-loaded silicone formulation in human renal cell carcinoma in nude mice.

Conventional therapy for renal cell carcinoma using interferon (IFN) has shown limited antitumor action. The IFN-loaded silicone formulation (IFN-SF) is a sustained-release formulation of human lymphoblastoid IFN, with a medical grade silicone elastomer used as the carrier material. We evaluated the antitumor effect of IFN-SF on human renal cell carcinoma cell line (KU-2) transplanted to nude mice. The treatment was started when the tumor nodules had grown 6 to 8 mm in diameter. IFN-SF, on an aqueous solution of IFN, was given by subcutaneous or peritumoral injection. Antitumor effects were evaluated according to tumor weights calculated as (long diameter) x (short diameter)2/2 in 7 groups consisting of 6 mice each. Serum IFN levels remained detectable up to 30 days after subcutaneous injection of IFN-SF. IFN-SF administered by the subcutaneous and peritumor route significantly inhibited growth of the tumor when compared with tumor growth in the untreated mice and mice treated with aqueous IFN solution. IFN-SF had equivalent inhibitory effects on tumor growth by peritumor and subcutaneous injection. Results indicated that the use of IFN-SF could reduce the frequency of injections and provide better treatment of patients with renal cell carcinoma because of its long-acting effect when it is used systemically.

Animals↗
PubMed1999

Integrin-linked kinase and associated proteins (review).

Integrin-linked kinase (ILK) is a recently identified cytoplasmic protein serine/threonine kinase implicated in integrin-, growth factor- and Wnt-signaling pathways. It contains several structurally conserved motifs including ankyrin repeats, pleckstrin-homology (PH) domain and protein kinase catalytic domain that are critical for signal transduction. Recent studies have documented that ILK plays important roles in bi-directional ( and ) transmembrane signaling pathways via integrins and other proteins, leading to regulation of cell adhesion, growth, survival, extracellular matrix deposition and potentially differentiation. Furthermore, ILK is implicated in tumorigenesis and ILK appears to be a useful diagnostic marker of certain human tumors. The identification of novel ILK-associated proteins will provide a better understanding of how ILK functions in intracellular signal transduction cascades and tumorigenesis.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Suppression of mitogenesis and regulation of cell cycle traverse by resveratrol in cultured smooth muscle cells.

Resveratrol (3,5,4'-trihydroxystilbene), a natural product derived from grapes, has been reported to exert a plethora of biological functions. Recent studies suggest that resveratrol could act as a cardioprotective agent by controlling the oxidation of low density lipoproteins, as well as the proliferation of endothelial cells. Since migration and proliferation of smooth muscle cells (SMCs) in the intima of susceptible vessels is also widely accepted as a requisite for atherogenesis, we investigated the effects of resveratrol on proliferation and cell cycle control of cultured smooth muscle cells. Results of these experiments are reported herein. Resveratrol reduces SMC proliferation in a dose-dependent manner, with 50-100 microM resveratrol resulting in 70-90% reduction of SMC proliferation induced by such diverse mitogens as serum, endothelin and PDGF. The anti-mitogenic effects of resveratrol are not mediated by the induction of apoptosis, but appear to relate to a G1-->S block in cell cycle traverse. These results give further support to the hypothesis that resveratrol holds promise as an anti-atherosclerotic agent.

Animals↗
PubMed1999

Allelic instability as a predictor of survival in Egyptian breast cancer patients.

This work was designed with the purpose of determining whether the presence of allelic imbalances (AI) such as microsatellite instability (MSI) and loss of heterozygosity (LOH) in chromosomes 2, 11, 13, and 17 in primary breast cancer could be used as prognostic indicators of patient survival. The DNA from breast cancers removed from 29 patients who were followed-up for up to five years was analyzed for MSI and LOH using a panel of 24 markers located at chromosome 2 (TPO, D2S131, D2S144, D2S171, D2S177, D2S119, D2S123, D2S147 and D2S136), chromosome 11 (C-RAS, Int-2, D11S940, D11S912), chromosome 13 (D13S289, D13S260, D13S267, D13S218, D13S263, D13S155, and D13S162), and chromosome 17 (D17S513, TP53, D17S855, and D17S785). The frequency of AI in the markers studied ranged from 30-55%, being highest for D11S912, D2S171, TP53 and D17S855. Univariate analysis showed association between overall survival rate and AI in 9 out of the 24 markers tested. Five of them were located at the area of the mismatch repair gene (MMR)-2 gene, two at 11p, one at 13q and one at 17p. Using multivariate analysis, it was observed that only pathological and clinical stage (defined as stage II or not) and AI at D2S171, D11S912, or D17STP53 generated significant predictive models for survival.

Adult↗
PubMed1999

[A comparative study of HLA-A locus in northern and southern Chinese bymeans of PCR/SSOP typing].

OBJECTIVE: To compare the HLA-A locus in a population selected from Beijing (northern group) with that in a population selected from Guangzhou (southern group). METHODS: HLA typing was performed by using PCR/SSOP method. A pair of primer and 54 probes were used. RESULTS: In 18 alleles identified, the differences in gene frequency between northern and southern Chinese were found. In northern group, A*0205, 0210 and 2901 were absent, and the frequencies of A*2601, 3001 and 3101 were higher than those of southern group; while in southern group, A*3103, 3201 and 6801 were absent, the frequencies of A*0203 and 1101 were higher than those of northern group; and in addition, six subtypes of A2 serological specificity, namely A*0201, 0203, 0205, 0206, 0207 and 0210, were found, in which A*0201 predominated. CONCLUSION: There are some differences in the genetic background of northern and southern Chinese. A2 subtypes have important implications for unrelated-donor transplantation.

Alleles↗
PubMed1999

[The relation between mitochondrial DNA mutation and aminogly- coside antibiotics-induced deafness].

OBJECTIVE: To nvestigate the relation between mitochondrial DNA mutation and aminoglycoside antibiotics-induced deafness. METHODS: Mitochondrial DNA (mtDNA) of peripheral blood from 48 sporadic cases was analysed using PCR-BsmAI digestion and PCR-direct DNA silver sequencing. RESULTS: Six of 48 sporadic patients had A to G mutation in 12S rRNA gene of mtDNA at nucleotide 1555. CONCLUSION: The results suggest that mtDNA 1555(G) mutation is related to the occurring of aminoglycoside antibiotics-induced deafness which can cause genetic susceptibility to aminoglycoside antibotics ototoxicity.

Adolescent↗
PubMed1999

Tubby-like protein 1 homozygous splice-site mutation causes early-onset severe retinal degeneration.

PURPOSE: To characterize the disease expression of an autosomal recessive human retinal degeneration associated with a mutation in TULP1 (tubby-like protein 1), a gene with currently unknown function. METHODS: Homozygotes and heterozygotes from an extended Dominican kindred with a TULP1 splice-site gene mutation (IVS14+1,G-->A) were studied clinically and with visual function tests. Sequence analysis of TULP1 was also performed in unrelated patients with severe retinal degeneration from a North American clinic population. RESULTS: Homozygotes had nystagmus, visual acuity of 20/200 or worse, color vision disturbances, bull's eye maculopathy, and peripheral pigmentary retinopathy. Younger patients had a relatively wide extent of kinetic visual fields; older patients had only peripheral islands. No rod function was measurable by psychophysics in any of the patients; markedly reduced cone function was detectable across the visual field of younger patients and in the remaining peripheral islands of older patients. Rod and cone electroretinograms (ERGs) were not detectable using standard methods; microvolt-level cone ERGs were present in some patients. Heterozygotes had normal visual function. No putative pathogenic sequence changes in TULP1 were observed in North American patients with comparably severe retinal phenotypes, mainly in the diagnostic category of Leber congenital amaurosis. CONCLUSIONS: This TULP1 splice-site mutation in homozygotes causes early-onset, severe retinal degeneration involving macular and peripheral cones and rods. The constellation of phenotypic findings suggests that the TULP1 gene product is critically important for normal photoreceptor function and may play a role in retinal development.

Adolescent↗
PubMed1999

Pathogenesis of type III hyperlipoproteinemia (dysbetalipoproteinemia). Questions, quandaries, and paradoxes.

Type III hyperlipoproteinemia (HLP) is a genetic disorder characterized by accumulation of remnant lipoproteins in the plasma and development of premature atherosclerosis. Although receptor binding-defective forms of apolipoprotein (apo) E are the common denominator in this disorder, a number of apparent paradoxes concerning its pathogenesis still exist. However, studies in transgenic animals are resolving the mechanisms underlying this disorder. PARADOX I: Defective apoE (commonly apoE2) is essential but not sufficient to cause overt type III HLP. In fact, most apoE2 homozygotes are hypolipidemic. Studies in apoE2 transgenic models have demonstrated the impact of other genes or hormones in converting the hypolipidemia to hyperlipidemia. PARADOX II: Among apoE2 homozygotes, men are more susceptible than women to type III HLP. Transgenic studies have shown that estrogen affects both LDL receptor expression and lipolytic processing, explaining the resistance of women to this disorder until after menopause. PARADOX III: ApoE deficiency is associated with hypercholesterolemia, whereas the type III HLP phenotype is characterized by both hypercholesterolemia and hypertriglyceridemia. The hypercholesterolemia is caused by impaired receptor-mediated clearance, whereas the hypertriglyceridemia is caused primarily by impaired lipolytic processing of remnants and increased VLDL production associated with increased levels of apoE. PARADOX IV: ApoE2 is associated with recessive inheritance of this disorder, whereas other defective apoE variants are associated with dominant inheritance. Determinants of the mode of inheritance are the differential binding of apoE variants to the LDL receptor versus the HSPG/LRP complex and the preference of certain apoE variants for specific lipoproteins. Thus, the pathogenesis of this sometimes mysterious disorder has been clarified.

Animals↗
PubMed1999

Age-related hippocampal changes in Bcl-2:Bax ratio, oxidative stress, redox-active iron and apoptosis associated with aluminum-induced neurodegeneration: increased susceptibility with aging.

We propose that aging is an important factor in the susceptibility of neurons to oxidative stress and to subsequent apoptosis. In the present report we demonstrate that aged rabbits treated intracisternally with aluminum maltolate exhibit intense intraneuronal silver positivity indicative of the formation of neurofilamentous aggregates, together with oxidative stress. These changes occur in the CA1 region of the hippocampus as well as in cerebral cortical areas. Apoptosis, measured by the TUNEL in situ technique, colocalizes with oxidative stress. Young animals treated with aluminum show few of these alterations, while age-matched controls are essentially negative. Further studies on the time course of these and related changes demonstrate that oxidative stress and redox-active iron accumulation in hippocampal neurons occur very rapidly, within a period of 3 hours, and increased in intensity at 72 hours. Changes suggestive of apoptosis are seen by 24 hours and are pronounced at 72 hours. In aged animals there is an initially intense immunopositivity at 3 hours for Bcl-2, with negative staining for Bax. By 72 hours, when apoptosis is strongly evident, Bcl-2 is negative and Bax strongly positive. In contrast to the aged rabbits, young animals treated similarly with aluminum exhibit much less oxidative stress with no apoptosis, and maintain Bcl-2 immunopositivity and negative Bax staining. Our findings strongly support the key role that oxidative damage plays in the process of neurodegeneration and in the increased vulnerability to aluminum-induced injury in the aged animal. These are novel observations which may have important implications for aiding in our understanding of the pathogenesis of neurodegeneration occurring in Alzheimer's disease.

Aging↗
PubMed1999

Prognostic significance of DNA image cytophotometry for osteosarcoma.

OBJECTIVE: To investigate the prognostic significance of DNA image cytophotometric data. STUDY DESIGN: Twenty-six osteosarcomas in patients without lung metastases were investigated for several cytophotometric data. In 24 cases, these data were correlated with the clinical course of the patients to assess the prognostic value of nuclear DNA content in osteosarcomas. RESULTS: Of all osteosarcomas, 96% showed aneuploid DNA content. Patients with tumors having a 2c deviation index (2cDI) of 12.00, DNA malignancy grade (DNA-MG) of 2.0, a mean DNA content (MDC) of 4.95 c, DNA index (DI) of 1.75 or mean nuclear area (MNA) of 130 microns 2 had a significantly lower overall survival rate as compared to those with lower values (P < .05). CONCLUSION: Image cytophotometric features, such as 2cDI, DNA-MG, MDC, DI and MNA, are of prognostic value in patients with osteosarcoma and free of lung metastases.

Adolescent↗
PubMed1999

Cytokine-induced macrophage differentiation: a tale of 2 genes.

Macrophages are versatile cells found in every tissue in the body. They must perform a number of diverse cellular functions that allow them to kill invading micro-organisms and neoplastic cells as well as produce growth factors involved in wound healing. Macrophages that develop these diverse functions arise from a common precursor. By a process of selective adaptation, the common precursor monocyte/macrophage differentiates into a distinctive macrophage with a different and specific phenotype, characterized by the expression of a specific set of gene products. The local environment plays a critical role in shaping or directing the pattern or pathway of macrophage differentiation. The authors have focused on 2 specific macrophage differentiation pathways in a murine bone marrow-derived macrophage model. One pathway is believed to play a role in wound repair and is characterized by the induction of insulin-like growth factor-1 (IGF-I). The second pathway is involved in macrophage cytocidal activation and is characterized by the induction of the inducible form of nitric oxide synthase (iNOS). The pleotropic cytokine tumour necrosis factor-alpha (TNF-alpha) appears to mediate macrophage differentiation along both of these pathways. Interferon-gamma (IFN-gamma), however, appears to act as a molecular switch. In the presence of IFN-gamma, stimulation of macrophages with TNF-alpha results in macrophage differentiation along a pathway in which iNOS is expressed, whereas, in the absence of IFN-gamma, stimulation of macrophages with TNF-alpha results in differentiation along a pathway in which IGF-I is expressed. The authors focus on some of the molecular events involved in TNF-alpha and IFN-gamma signal transduction and the regulation of iNOS and IGF-I genes in macrophages.

Animals↗
PubMed1999

Hirudin display on the surface of bacteriophage M13.

Hirudin was fused to the N terminus of M13 minor protein gp3 (197-406) through a linker GGGS by inserting both the hirudin gene and the gp8 signal sequence into the modified phagemid vector pCANTAB 5V to construct pCANTAB 5G8-Hir. The expressed fusion protein was directed by gp8 signal peptide into the periplasm and assembled to the phage particle to form the hirudin-phage. The fusion protein and fusion phage were detected with biotin-thrombin by Western blotting analysis. Antithrombin activity analysis confirmed that the hirudin portion in the fusion protein and fusion phage bear similar native conformation. The successful display of hirudin on the surface of M13 phage laid a sound foundation for the further study on directed evolution of antithrombotic proteins with altered properties.

Antithrombins↗
PubMed1999

Effects of acupuncture on the pituitary-thyroid axis in rabbits with fracture.

PURPOSE: To observe the effects of acupuncture on the pituitary-thyroid axis in rabbits with fracture. METHOD: 36 male rabbits with a 3-mm width experimental defect in the middle segment of the left radius were randomly divided into the treatment group and control group, and the changes in serum T3, T4 and TSH contents in different weeks were investigated. RESULTS: Serum T3, T4 and TSH contents in the treatment group all were higher than those in the control group, with statistically significant differences in the contents of T4 and TSH in the second week and T3 content in the fourth week (P < 0.01 or P < 0.05). CONCLUSION: The action of promoting union of fracture is possibly related with the pituitary-thyroid axis.

Animals↗
PubMed1999

Ca2+ sensitivity of contractile system and Ca2+ release from sarcoplasmic reticulum in skinned myocardium from rats with pressure overload LV hypertrophy and heart failure.

AIM: To explore the possible subcellular mechanisms underlying the decreased contractility of myocardium in left ventricle failured hearts caused by pressure overload. METHODS: Left ventricle pressure overload hypertrophy (LVH) and congestive heart failure (CHF) models were created in rats by ascending aortic banding. Left ventricle trabeculae skinned fibers were prepared by treatment with saponin 500 or 50 mg.L-1. Relative Ca(2+)-activated tensions (T6.0% and T5.6%) of saponin (500 mg.L-1)-skinned fibers were taken as the indices of Ca2+ sensitivity of contractile protein, caffeine-induced contracture of saponin 50 mg.L-1-skinned fibers was an index of Ca2+ release from sarcoplasmic reticulum (SR). RESULTS: 1) There was no significant difference in relative Ca2+ activated tensions among CHF, LVH, and Sham-operated group in basic situation (P > 0.05). After treatment with caffeine 10 mmol.L-1, the increase in value of delta T% were significantly higher in LVH and CHF compared with that in Sham-operated control (P < 0.01). 2) The amplitudes of caffeine (5 and 10 mmol.L-1)-induced contracture were (0.66 +/- 0.14) and (1.20 +/- 0.27) g/mm2 in control group, 19.8% and 25.8% lower in LVH (P < 0.05), 78.8% and 80.9% much more lower in CHF (P < 0.01). CONCLUSION: Decreased SR Ca2+ release was the main factor responsible for depressed contractility in failured myocardium while the Ca2+ sensitivity of contractile protein might not be involved.

Animals↗
PubMed1999

[Application of fluorescence insitu hybridization technique for prenatal diagnosis of chromosome abnormality in amniotic cells].

OBJECTIVE: To study the technique and diagnostic value of fluorescence in situ hybridization (FISH) in chromosome abnormality for prenatal diagnosis. METHODS: Amniocenteses were performed in 34 pregnant women of 16-23 gestational weeks with indications for prenatal diagnosis. The amniotic fluid samples were cultured in Chang's medium. The metaphase chromosomes were hybridized in situ with the human centromere probes, alpha-satellites DNA probes of X, Y, 13, 21, 18 chromosomes and all primer chromosome probes. These probes were conjugated by Biotin and Dioxin then. The treated slides were examined and taken photos under the fluoromicroscope. RESULTS: By FISH technique, normal karyotypes were shown in 31 cases: 16 cases of 46, XY, 15 cases of 46, XX. Abnormalities were found in 3 patients which were 47, XY + 21; 47, XY + 18 and 45, X/46, X, r (X) respectively. CONCLUSION: Using FISH technique to detect chromosome abnormalities in amniotic fluid for prenatal diagnosis is a reliable method which is rapid and accurate. It has higher sensitivity and specificity in finding chromosome structure abnormalities and marking chromosome DNA sequences.

Adult↗
PubMed1999

[Determination of 6-methoxy-2-naphthylacetic acid, a major metabolite of nabumetone, in human plasma by HPLC].

This paper reports a sensitive and rapid method for determining 6-methoxy-2-naphthylacetic acid (MNA), a major metabolite of nabumetone in human plasma using naproxen as the internal standard. High performance liquid chromatograph model 680 (Waters, USA) with a variable wavelength UV detector and reversed-phase YWG-C18 column (10 microns, 250 x 4.6 mm) was used. After the addition of acetate buffer(pH3.0), the plasma sample was extracted with methylene chloride. The mobile phase of methanol-pH3.0, 0.02 mol/L acetate buffer(74:26) was pumped at 1.0 ml/min through the column. The detector at 0.01AUFS was set at 270 nm. The retention times for MNA and naproxen were 3.98 min and 4.73 min respectively. Standard curve was linear in the concentration range of 0.5 to 64 mg/L. The detection limit in serum was 0.02 mg/L. Extraction recovery was 88%-94%; method recovery 96%-102%; withinday RSD less than 3.5%; inter-day RSD less than 5%.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

[Simultaneous determination of norepinephrine and epinephrime in plasma by using high performance liquid chromatograph].

A sensitive and rapid method was reported for the determination of nerepinephrine (NE) and epinephrine (E) in plasma by using high-performance liquid chromatography with an electrochemical detector (HPLC-EC) and YWG-C18 column(5u). 3,4-Dihydroxybenzylamine(DHBA) was used as an internal standard. The mobile phase of 0.05 mol/L actate buffer(pH3.0)-methanol-0.05 mol/L EDTA-Na2(78:20:2) with of 200 mg/L SDS solution was pumped through the column with a flow rate of 1.0 ml/min. The lengths of retention time for NE, E and DHBA(IS) was 7.3 min, 8.3 min and 10.4 min, respectively. The standard curve was linear within the concentration range of 31.25 to 4000 ng/L for NE and E (NE: r = 0.9999 E: r = 0.9996). The within day RSD (%) were less than 1.87% for NE and less than 2.07% for E, inter-day RSD(%) were less than 8.92% for NE and less than 9.65% for E respectively. The average extraction recovery(%) for NE and E were 93.5% +/- 5.50% and 91.3% +/- 1.77% respectively. This method has been applied to the diagnosis of pheochromocytoma and clinical research.

Adrenal Gland Neoplasms↗