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Biomedical subjects

Y Yu

Publications and source records attributed to Y Yu.

At least 145 records · Page 8Linked to original sources
PubMed2001

Molecular cloning and characterization of NAG-7: a novel gene downregulated in human nasopharyngeal carcinoma.

OBJECTIVE: To identify novel tumor suppressor genes at chromosome 3p24-26 in human nasopharyngeal carcinoma (NPC). METHODS: Twenty epithelial-derived expressed sequence tags (EST) were selected from chromosome 3p24-26. RT-PCR and Northern blot were used to detect the expression of the ESTs in NPC cell line, HNE-1, and primary cultures of normal nasopharyngeal epithelial cells. One EST, which was substantially downregulated in the HNE-1 cell line, was detected in 19 NPC biopsy samples. cDNA library screening was used to get its full sequence and the sequence of this novel gene was analyzed. RESULTS: A novel gene located at chromosome 3p25.3 was obtained and named NAG-7. It was downregulated in 26.3% (5/19) of NPC biopsy samples. Its 1677 bp full length cDNA had a potential open reading frame predicting a 94 amino acid protein with a molecular weight of 11,023.87 Dalton. Analysis of the NAG-7 gene showed that it was a transmembrane protein containing a protein kinase C phosphorylation site and a myristyl site. It has no significant homology to any reported genes in the database of GenBank. CONCLUSION: NAG-7 is a novel gene downregulated in NPC, suggesting that it may be involved in the development of NPC.

Amino Acid Sequence↗
PubMed2001

[Study on the intestinal microbial colonization resistance in patients with chronic severe hepatitis].

OBJECTIVE: To investigate the changes of microbial colonization resistance of the bowel in patients with chronic severe hepatitis. METHODS: The fecal flora bifidobacteria, enterobacteriaceae, enterococci, and yeasts of subjects (chronic severe hepatitis, chronic hepatitis, and healthy volunteers) were quantitatively and qualitatively analyzed by Mitsuoka's methods. While the ratio of bifidobacterium to enterobacteriaceae ( B/E ratio ) was calculated. RESULTS: The number of bifidobacteria and the B/E ratio in chronic severe hepatitis group was significantly deceased compared with that of the control group (P<0.001). The number of enterobacteriaceae and yeasts was significantly increased compared with that of control group (P<0.001 and P<0.01, respectively). CONCLUSIONS: The results suggest that the intestinal microbial colonization resistance in patients with chronic severe hepatitis is seriously impaired.

Bifidobacterium↗
PubMed2001

Treatment of aplastic anemia by the kidney-tonifying and mediating method.

In this series of 65 cases of aplastic anemia, 26 cases were treated by the kidney-tonifying and mediating method, 19 cases by western drugs, and the remaining 20 cases only by tonifying the kidney as controls. The results showed that the kidney-tonifying and mediating method was significantly superior in the total effective rate to the method of western drugs and that of tonifying the kidney alone (P < 0.01), and it was also superior in the improvement of symptoms, myelogram, and peripheral blood count to the other two methods.

Adolescent↗
PubMed2001

[The determination of p53 protein in maxillary sinus carcinoma and its prognosis value].

OBJECTIVE: To determine whether p53 protein overexpression correlated with early tumor recurrence in carcinoma of maxillary sinus. METHOD: Forty-five patients with T2N0M0 squamous cell carcinoma of maxillary sinus were treated with operation and/or radiotherapy. The median follow up time was 3 years. The ratio of local control was 62.2% (28 patients), as control group; The ratio of local recurrence and/or metastasis was 37.8% (17 patients), as experiment group. Cancer specimens were obtained before treatment. p53 protein overexpression, which indicated a mutated p53 gene, was analyzed by immunohistochemistry, using the mouse monoclonal antibody DO-7. RESULT: Approximately 88.2% of the carcinoma that recurred locally overexpressed p53 protein, compared with only 28.6% of those with local control (P < 0.01). No significant relation was noted between p53 protein overexpression and pathohistologic grade. Intensity of staining did not predict tumor recurrence. CONCLUSION: The study demonstrated that the p53 protein is an important prognostic marker on gene level for maxillary sinus carcinoma.

Carcinoma, Squamous Cell↗
PubMed2001

[Audiological findings of the aging across the urban and rural of Suzhou].

OBJECTIVE: To determine the epidemiological characteristics of old people's hearing. METHOD: Questionnaires, physical examination, audiometry and bio-chemical tests were performed on the elders above 60 years old in part of the urban and rural area of Suzhou with random sample survey. RESULT: A total of 1,040 individuals was investigated, among which 505 were from urban, and 535 were from rural. 33 of 505 senior citizen (6.53%) were nososacusis, 282 (55.84%) were presbycusis and 21 (4.16%) were noise-induced deafness; In the rural area, 35 of 535 (6.54%) were nososacusis, 232 (43.36%) were presbycusis, and 4 (0.75%) were noise deafness. There was significant difference of the incidence of presbycusis between urban and rural. The audiometric thresholds chart manifested that the threshold elevated with age increasing especially in high-frequency. CONCLUSION: The etiology of hearing loss of elders was mainly due to presbycusis. The higher incidence of psychotic disorder in urban probably caused a correspondingly higher incidence of presbycusis. So the prevention and cure of some age-induced diseased (e.g. hypertension, arteriosclerosis and diabetes) may be helpful to release and improve presbycusis.

Aged↗
PubMed2001

[The preliminary research of maxillary sinus cancer on oncogene level].

OBJECTIVE: To determine the oncogene c-myc, bcl-2' product expression in the maxillary sinus cancer and to investigate its clinical significance. METHOD: In 46 maxillary sinus cancer and 56 normal nasal mucous membrane, immunochemical method was adopted to determine oncogene c-myc and bcl-2' product. RESULT: In the normal nasal mucous membrane, the positive rates of oncogene c-myc and bcl-2' product were 0; in the maxillary sinus cancer, the positive rates of c-myc and bcl-2' product were 73.91 (34/46), 60.87 (28/46) respectively. The positive rate of c-myc' product in the relapse group(91.67%, 11/12) was significantly higher than that in the non-relapse group(67.65%, 23/34), P < 0.01; the positive rate of bcl-2' product in the relapse group(50%, 6/12) was significantly lower than that in the non-relapse group(64.71%, 22/34), P < 0.05; the positive rate of c-myc' product in the stage IV (88.89%, 8/9) was significantly higher than that in the stage II (63.64%, 7/11), P < 0.05; the positive rate of bcl-2' product in the stage II (72.73%, 8/11) was significantly higher than that in the stage IV (55.56%, 5/9), P < 0.05; the positive rate of bcl-2' product was in the negative correlation to the pathological grade of primary carcinoma. CONCLUSION: The oncogene c-myc and bcl-2 take part in the genesis and advancing course of maxillary sinus cancer. Their products were the important oncogology indexes, which might be useful to determine illness condition and predict relapse.

Carcinoma, Squamous Cell↗
PubMed2001

[The cluster analysis of trace elements in fructus cnidii from different region].

The contents of trace elements in Fructus Cnidii from different region were assayed by atom absorption spectrum and analyzed by cluster analysis methods. The results showed the contents of trace elements from different regions were different, which had some relativity with habitats, but should be further studied.

Cluster Analysis↗
PubMed2001

[Rapid construction of directional cDNA library from human nasopharynx].

OBJECTIVE: To construct a directional cDNA library from human adult nasopharynx by SMART (switching mechanism at 5' end of RNA transcript) technique. METHODS: The total RNA was separated from human adult nasopharynx epithelial tissue and the first-strand cDNA was synthesized through reverse transcription by a modified oligo(dT) primer(contained sfi IB site) while the SMART oligonucleotide(contained sfi IA site) was utilized as a template so that the first-strand cDNA could be extended over the 5' end of mRNA. The double-strand cDNA was amplified by LD-PCR(long-distance PCR) with the above two primers and then digested by sfi I (IA & IB) restriction enzyme. After cDNA size fractionation through CHROMA SPIN column, the double-strand cDNA was ligated into the sfi I-digested lambda TripIEx2 vector and then the recombinant DNA was packaged in vitro. RESULTS: The unamplified human adult nasopharynx cDNA library consists of 1.5 x 10(6) independent clones in which the percentage of recombinant clones is about 100%. The titer of the amplified cDNA library is 3.8 x 10(9) pfu/ml and the average exogenous inserts of the recombinants is 1.5 kb. CONCLUSION: These results shows that the human adult nasopharynx cDNA library has an excellent quality and lays solid foundation for screening and cloning new tumor suppressor genes of nasopharyngeal carcinoma(NPC) and tissue-specific genes of human nasopharynx.

Adult↗
PubMed2001

Gut barrier function damage following multiple firearm injuries in a porcine model.

OBJECTIVE: To study the characteristics and pathogenesis of gut barrier damage following multiple firearm injuries in a porcine model. METHODS: Twenty-four small pigs were divided into 4 groups: control group (n = 6, group C), group H (n = 6, gunshot-induced tangential fracture of parietal bone), group L (n = 6, gunshot-induced comminuted fracture of bilateral femora) and group M (n = 6, combined group H + L). Gastric intramucosal pH (pHi), plasma endotoxin levels in portal vein, and plasma D-lactate levels were measured and blood samples were cultured at different intervals after trauma. The animals were sacrificed at 72 h following trauma and intestinal tissues were harvested for pathological examination and diamine oxidase (DAO) activity measurement. RESULTS: In group M at 72 h, pHi was significantly lower than that of group H and L ( P < 0.01), and plasma endotoxin level was significantly higher than that of group H (P < 0.01) and group L (P < 0.05). Simultaneously, in group M, D-lactate level was markedly higher than that of group H ( P < 0.01), and incidence of positive blood culture was much higher than that of group H and L ( P < 0.05). Necrosis and exfoliation were revealed at ileum villus top in all trauma groups, especially in group M, in which ileum DAO activity declined most significantly as well. CONCLUSION: Multiple trauma is prone to cause gastrointestinal ischemia even without hemorrhagic shock. The damage of gut barrier in multiple trauma appears to be more severe than that in one-site trauma, thereby promoting gut-derived endotoxemia and bacterial translocation and contributing to the development of endogenous infection.

Amine Oxidase (Copper-Containing)↗
PubMed2001

[Clinical evaluation of pulpotomy in the treatment of deciduous teeth with deep dentine caries].

OBJECTIVE: To study the curative effect of pulpotomy in the treatment of deciduous teeth with deep caries. METHODS: 45 deciduous molars with deep caries from 3 8 years old children were selected at random. Pulpotomy was performed on these treated teeth. Clinical examination and X-ray films for the treated teeth were taken to follow up all the teeth at 6 months, one year and two years respectively after treatment. RESULTS: At one year after treatment, 45 cases were followed up, the rate of success in clinical examination and in X-ray photographs both were 100%. While at two years after treatment, 42 cases were followed up and 3 cases were lost, the rate of success in clinical examination was 95% and the rate of success in X-ray photographs was 88%. The reasons of the failure were internal absorption and pulpitis followed by fracture and exfoliation of the obturators in the treated teeth. CONCLUSION: Pulpotomy in deciduous teeth with deep caries was a reliable and effective method. It is necessary to follow up the treated teeth by X-ray at regular intervals after treatment.

English Abstract↗
PubMed2001

[A clinical trial of oxymatrine in treating chronic viral hepatitis type B].

OBJECTIVE: To investigate the therapeutic effect of oxymatrine on chronic viral hepatitis type B. METHODS: 303 patients were randomly allocated either to a treatment group or a control group. The treatment group consisted of 253 patients treated with intravenous or intra-muscular injection of oxymatrine and oral oxymatrine capsule. Oral tiopronin was used in the control group. RESULTS: At the end of treatment, the rate of normal ALT was similar among the different groups. The rate of normal ALT was 53.3% - 58.3% in the three oxymatrine groups six months after the end of treatment. It was higher than that of the tiopronin group (P < 0.05). After a follow up of six months, the rate of negative HBeAg was 30.0% - 40.9% in the three oxymatrine groups. It was higher than that of the tiopronin group (16.7%). The rate of negative HBV DNA was 39.2% - 49.5% in the three oxymatrine groups. It was also higher than that of the tiopronin group. CONCLUSION: Oxymatrine can improve the liver function and increase the negative rate of HBeAg and HBV DNA in the patients with chronic hepatitis B. The therapeutic effect of oxymatrine will persist after the cessation of administration.

Adolescent↗
PubMed2000

Sds3 (suppressor of defective silencing 3) is an integral component of the yeast Sin3[middle dot]Rpd3 histone deacetylase complex and is required for histone deacetylase activity.

SDS3 (suppressor of defective silencing 3) was originally identified in a screen for mutations that cause increased silencing of a crippled HMR silencer in a rap1 mutant background. In addition, sds3 mutants have phenotypes very similar to those seen in sin3 and rpd3 mutants, suggesting that it functions in the same genetic pathway. In this manuscript we demonstrate that Sds3p is an integral subunit of a previously identified high molecular weight Rpd3p.Sin3p containing yeast histone deacetylase complex. By analyzing an sds3Delta strain we show that, in the absence of Sds3p, Sin3p can be chromatographically separated from Rpd3p, indicating that Sds3p promotes the integrity of the complex. Moreover, the remaining Rpd3p complex in the sds3Delta strain had little or no histone deacetylase activity. Thus, Sds3p plays important roles in the integrity and catalytic activity of the Rpd3p.Sin3p complex.

Fungal Proteins↗
PubMed2000

[Effect of baicalin and dexamethasone on cytokines in brain tissue of infectious brain edema].

OBJECTIVE: To explore the effect of baicalin(BC) and dexamethasone(DXM) on interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha(TNF-alpha) in brain tissues of infectious brain edema. METHODS: The infectious brain edema model induced by pertussis bacilli(PB) was used. Brain water content(WC), content of Na+ and the levels of IL-1 beta, TNF-alpha were determined, and the morphological changes were observed under the light microscope. RESULTS: The results showed that the levels of WC, Na+, IL-1 beta and TNF-alpha in group PB were higher than those in group of normal saline(NS) (P < 0.01). And they were lower in groups BC and DXM than those in group PB(P < 0.05). In groups BC and DXM, there were no significant difference in the contents of water, Na+, IL-1 beta and TNF-alpha(P > 0.05). The water contents were positive linar correlated with IL-1 beta or TNF-alpha(P > 0.05). The water contents were positive linear correlated with IL-1 beta or TNF-alpha contents(r = 0.9381, 0.8349, P < 0.01). The structure of brain tissues in group NS was normal. In group PB, there were severe edema in brain tissues. In groups BC and DXM, the edema of brain tissues was reduced. CONCLUSIONS: The results suggest that the protective effect of BC and DXM against infectious brain edema were similar, the mechanism may be associated with the reduction of TNF-alpha and IL-1 beta.

Animals↗
PubMed2000

Functional evidence for an ovarian cancer tumor suppressor gene on chromosome 22 by microcell-mediated chromosome transfer.

The identity of many tumor suppressor genes important in epithelial ovarian cancer tumorigenesis remains unknown. In an effort to localize a novel tumor suppressor on chromosome 22, a psv2neo tagged human chromosome 22 was transferred into the malignant epithelial ovarian cancer cell line, SKOv-3, by microcell-mediated chromosome transfer. Complete suppression of the transformed phenotype was observed in 16 of 18 individual microcell hybrid clones as evidenced by the complete abrogation of cell growth under anchorage-independent conditions. In vitro doubling times were also dramatically reduced, as was the ability to form subcutaneous tumors in CD1 nu/nu mice. Only one polymorphic marker, D22S429, segregated with decreased transformation and tumorigenic potential, suggesting that an unrecognized tumor suppressor may localize to chromosome 22q11-q12. These data provide functional support for the presence of a novel tumor suppressor locus (or loci) on chromosome 22 that is important in ovarian cancer tumorigenesis.

Animals↗
PubMed2000

Ssn6-Tup1 interacts with class I histone deacetylases required for repression.

Ssn6-Tup1 regulates multiple genes in yeast, providing a paradigm for corepressor functions. Tup1 interacts directly with histones H3 and H4, and mutation of these histones synergistically compromises Ssn6-Tup1-mediated repression. In vitro, Tup1 interacts preferentially with underacetylated isoforms of H3 and H4, suggesting that histone acetylation may modulate Tup1 functions in vivo. Here we report that histone hyperacetylation caused by combined mutations in genes encoding the histone deacetylases (HDACs) Rpd3, Hos1, and Hos2 abolishes Ssn6-Tup1 repression. Unlike HDAC mutations that do not affect repression, this combination of mutations causes concomitant hyperacetylation of both H3 and H4. Strikingly, two of these class I HDACs interact physically with Ssn6-Tup1. These findings suggest that Ssn6-Tup1 actively recruits deacetylase activities to deacetylate adjacent nucleosomes and promote Tup1-histone interactions.

Acetylation↗
PubMed2000

Synthesis of 2',3'-dideoxy-2'-trifluoromethylnucleosides from alpha-trifluoromethyl-alpha,beta-unsaturated ester.

The treatment of alpha-bromo-alpha,beta-unsaturated esters 2 with FSO(2)CF(2)CO(2)Me and CuI in DMF/HMPA constitutes a new synthetic scheme for the preparation of alpha-trifluoromethyl-alpha, beta-unsaturated esters 3. The trifluoromethylation of (Z)/(E)-ethyl 3-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]-2-bromo-2-propenoate (2e), which is derived from 1-(R)-glyceraldehyde acetonide, yields the key intermediate alpha-trifluoromethyl-alpha,beta-unsaturated esters 3e. This is transformed into anomeric acetates 8a and 8b and is used for the synthesis of a number of 2', 3'-dideoxy-2'-trifluoromethylnucleosides.

Acrylates↗
PubMed2000

Striatal extracts promote the survival and phenotypic expression of rat fetal dopaminergic neurons in vitro.

To begin to identify novel protein(s) that acts on nigral dopaminergic (DA) neurons, we characterized trophic effects of DA-depleted striatum on survival of fetal DA neurons in the present study. Treatment of ventral mesencephalic cultures with the striatal extracts delayed DA cell death in a dose-dependent manner. This effect was partially dependent on brain-derived neurotrophic factor (BDNF), but not glial cell line-derived neurotrophic factor (GDNF), present in the extracts. Furthermore, we addressed the hypothesis that the striatum-derived substances can elicit DA phenotypic expression of striatal cells in cultures. The striatal extract was found to be able to induce expression of tyrosine hydroxylase in cultured striatal cells in the presence of dopamine. These data suggest that denervation of the striatum resulted in production of neurotrophic factors, including BDNF and as-yet-unidentified trophic substances, which may be responsible for the increased survival and DA phenotype expression in DA neurons.

Animals↗