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Biomedical subjects

Y Xu

Publications and source records attributed to Y Xu.

At least 451 records · Page 25Linked to original sources
PubMed2000

[A 1:2 matched case-control study on the risk factors of uterine myomas].

OBJECTIVE: To investigate the risk factors and their association with Uterine myomas. METHODS: A 1:2 matched case-control study was carried out in Guangzhou including 211 cases and 422 controls. Data were analyzed with conditional logistic regression. RESULTS: Results showed that Pelvic inflammatory, Erosion of Cervix, Menopathy, Adnexitis and family history of Uterine myomas were identified as risk factors, with odds ratios of 3.101, 2.904, 3.942, 7.742 and 2.426 respectively while delayed menstruation was proved to be a preventive factor, with odds ratios of 0.841. CONCLUSION: Uterine myomas seemed to be related to Pelvic inflammatory, Erosion of Cervix, Adnexitis, Menopathy and family history of Uterine myomas.

Adult↗
PubMed2000

[A cross-sectional study on injuries in the residents of Shijiazhuang city].

OBJECTIVE: To comprehend current status of injury in the residents of Shijiazhuang city and to lay a foundation for prevention from injury. METHODS: A retrospective study on injury in the 21,544 residents of two and six rural villages was conducted by multi-stage stratified sampling. RESULTS: Standardized incidence rate of injury was 4.21% in Shijiazhuang city, higher in the rural than in the urban areas and higher in men than in women. The top three causes of injuries were traffic accidents, falls and poisoning. Traffic accidents and poisoning ranked the first place in the urban areas and in the rural areas, respectively. Falls occurred mostly in those aged less than 14 years and more than 60 years. Gas poisoning and traffic accidents occurred more often in those aged 15 - 34 years and traffic accidents ranked the first in the age group of 35 - 59 years old. Standardized mortality rate of injury was 48.78 per 100,000, higher in the rural than in the urban areas. Standardized mortality rate of suicide was the highest with 23.21 per 100,000 in the countryside and that of traffic accidents ranked the next. In average, 22 years of potential life lost, 17 work years of potential life lost and nine valued years of potential life lost for each death were caused by injury. Disability rate caused by injury was 1.1 percent. Direct economic loss for each case with injury cost 679.98 RMB yuan. Incidence rate for traffic accidents ranked the highest and the most severe in all injuries. CONCLUSION: Injury has become an important public health problem harmful to the people's health.

Accidental Falls↗
PubMed2000

[Telomerase activity in human non-small cell lung cancer (NSCLC)].

OBJECTIVE: To investigate the activity of telomerase in human non-small cell lung cancer (NSCLC) and the correlation of telomerase activity with the cancer development. METHODS: Totally 48 cases of NSCLC tissues were studied accompanied with 7 cases of normal lung tissues and 12 samples of lung tissues adjacent to the tumor. The telomerase activity was detected using Telomerase PCR ELISA kit. Statistics study included chi(2)-test and the exact probabilities. The significance level chosen was P value less than 0.05 (P < 0.05), and all tests were two-sided. RESULTS: 75% (36/48) of NSCLC tissues possessed the expression of telomerase activity and only 8.33% (1/12) of tissues adjacent to tumor and none of the normal lung tissue enabled to express telomerase activity. The statistical difference was significant (P < 0.05). No significant difference was found between different histological types of NSCLC, however, the frequency of telomerase expression differed significantly between tumors of well/mordeately differentiated and poorly differentiated; stage I and stage II/III. CONCLUSION: Telomerase activity might be a good marker in estimating the occurrence, development and diagnosis of NSCLC.

Adenocarcinoma↗
PubMed2000

[The toxicity of busulphan and cyclophosphamide as the preparative regimen for allogeneic peripheral blood stem cell transplantation].

OBJECTIVE: To analyse the treatment-related complications of busulphan and cyclophosphamide (BU-CY) as the conditioning regimen for allogeneic peripheral blood stem cell transplantation (allo-PBSCT). METHODS: The clinical data of 40 leukemia patients undergoing allo-PBSCT between June 1997 and May 1999 in our BMT center were retrospectively analysed. RESULTS: Recovery of neutrophil and platelet was achieved at a median of day +13 (9 - 28) and day +12 (7 - 60) respectively. Acute GVHD occurred in 17 of 40 patients (42.5%) with grade II-IV in 10 patients (25%). Chronic GVHD developed in 21 out of 30 evaluable patients (70%). Mild to severe mucositis occurred in 30 patients (75%), and 4 of them had severe esophagitis with bleeding. Haemorrhagic cystitis developed in 8/40 (20%) patients, the median time of its onset was day +100 (+7 to +165). Six of 40 patients (15%) developed interstitial pneumonia (IP), 5 of them were due to cytomegalovirus infection, and the remaining one due to pneumocystis carinii infection. No hepatic veno-occlusive disease was observed and no seizure occurred. During the median follow-up of 480 (300 - 1000) days, 4 (10%) patients relapsed and 8 (20%) patients died of the transplant-related complications. The 3 year leukemia-free survival rate was 70%. CONCLUSION: BU (domestic busulfan)-CY regimen is relatively easy to administer and well tolerated, with low extramedullary toxicities.

Acute Disease↗
PubMed2000

Experimental study on apoptosis of HL-60 cell induced by arsenic trioxide.

OBJECTIVE: To explore the mechanism of arsenic (arsenic trioxide, AS2O3) in treating leukemia. METHODS: The in vitro effect of arsenic trioxide on HL-60 model double-labelled with PI/AnnexinV-FITC was studied ith flow cytometry. Function on telomerase activity was also observed. RESULTS: After the effect of arsenic on HL-60 cell line, PI negative/AnnexinV-FITC positive cells increased, it mainly acts at the G2-M phase that suggests the apoptosis takes place, mild inhibition on telomerase was also found 48 hours later. CONCLUSION: Apoptosis induced by arsenic trioxide was the main mechanism in killing or inhibiting leukemic cells.

Apoptosis↗
PubMed2000

[Determination of ochratoxin A by ELISA].

The determination of ochratoxin A by Enzyme-linked immunosorbent assay (ELISA), including the method of preparation of antigen and antibody, and the promising of ELISA in mycotoin determinations was introduced.

Enzyme-Linked Immunosorbent Assay↗
PubMed2000

[Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in C. I. violet 23 dyes and chloranils].

A simple method for the extraction and analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in dyes and chloranils has been developed. Five chloranil samples and a dye sample (C.I. Violet 23) were dissolved and dispersed in sulfuric acid, followed by extracting with toluene. After the clean-up by alumina, silica and Florisil columns, the PCDD/F extracts were analysed by high resolution gas chromatograph/high resolution mass spectrometry (HRGC/HRMS). It was found that the dye and its raw material contained octachlorinated dibenzodioxin/furans (OCDD/F) at 1 to 100 micrograms/g level and hexa-, hepta-congeners ng/g levels. The toxic equivalencies (TEQ) of the samples were all beyond the dangerous level. They are found to be one of the important sources of dioxins in textile fabrics. Further investigations were performed to identify their real source.

Benzofurans↗
PubMed2000

[Treatment of cancer of the nasal cavity in 128 cases].

OBJECTIVE: To investigate the credibility of combined radiotherapy and surgery for cancer of the nasal cavity and their prognostic factors. METHODS: One hundred and twenty-eight patients were treated from Mar. 1977 to Aug. 1993 receiving either radiotherapy alone (R group, 89), radiotherapy plus surgery (R + S group, 21), surgery plus radiotherapy (S + R group, 13), or surgery alone (S group, 5). RESULTS: The overall 5-year survival rate was 42.2%. The 5-year survival rates of R, R + S and S + R groups were 33.7%, 57.1% and 61.5%, respectively. The 5-year survival rate of combined therapy for squamous cell carcinoma and low differentiated cancer were higher than that of radiotherapy alone, and the effect of radiotherapy alone for undifferentiated carcinoma was better. In early stage, the 5-year survival rate of the radiotherapy alone and combined therapy did not differ significantly. For III and IV stages, the 5-year survival rate of R + S combined therapy was higher than those with radiotherapy alone (P < 0.01). CONCLUSIONS: For early lesions(Stage I and II), R alone or R + S give better results. For advanced lesions(Stage III and IV), combined radiotherapy and surgery is preferred. Radiotherapy alone is indicated for poorly differentiated cancers. Combined radiotherapy plus surgery is preferred for squamous cell carcinoma.

Adult↗
PubMed2000

[Intracytoplasmic injection with sperm from ejaculation, epididymis and testis in treating different male infertility with oligo-asthenozoospermia or azoospermia ].

OBJECTIVE: To retrospectively study 400 intracytoplasmic sperm injection (ICSI) cycles by using three different sources of sperm. METHOD: Different male infertility with oligo-asthenozoospermia or azoospermia was treated by ICSI using sperm from ejaculation, epididymis and testis. RESULTS: In the ejaculation group (n = 277), the fertilization rate was 69.6% and the clinical pregnancy rate 28.9%. In the 104 cycles using epididymal sperm, the fertilization and clinical pregnancy rate was 65.9% and 37.5% respectively. And the fertilization and clinical pregnancy of testis sperm (n = 19) was 65.7% and 21.1%. The difference of fertilization and clinical pregnancy rate among the three groups were not significant. CONCLUSIONS: Male infertility of different causes can be treated by ICSI. The outcome has nothing to do with the common parameter of semen except that the sperm motility is 0, but the effectiveness of ICSI should be studied by long-term observation.

Adult↗
PubMed2000

[Changes of p16 gene, cyclin D1 gene, and pRb protein in human pancreatic adenocarcinoma cell lines].

OBJECTIVE: To investigate the abnormalities of the relative factors of pRb-p16 cell regulatory pathway in pancreatic adenocarcinoma. METHODS: Five strains of human pancreatic adenocarcinoma cell lines were analysed by PCR and single-strand conformation polymorphism (SSCP) for homozygous deletion and mutation of the p16 gene, respectively. The gene amplification of cyclin D1 was detected by Southern blot analysis and the protein expression of pRb gene was examined by Western blot analysis. RESULTS: Homozygous deletion of exon 1 were found in two cell lines and no mutation was found within exon 1 and exon 2 in five cell lines. Cyclin D1 gene amplification was observed in one cell line and all of the five cell lines showed hyper-phosphorylated pRb protein. CONCLUSION: These findings have demonstrated that there are abnormalities of pRb-p16 regulatory pathway in pancreatic adenocarcinoma cell lines, revealing the alteration of the p16 and cyclin D1 genes.

Adenocarcinoma↗
PubMed2000

[Effect of sodium azide on mitochondrial membrane potential in SH-SY5Y human neuroblastoma cells].

OBJECTIVE: To study the role of mitochondrial deficiency in the pathogenesis of neurodegenerative disease by investigating the energy metabolism in a sodium azide inhibited cytochrome-c oxidase SH-SY5Y Cell model. METHODS: Human neuroblastoma SH-SY5Y Cells were exposed to sodium azide, then mitochondrial complex IV activity was assayed by microassay method; cell viability was measured by Thiazolyl blue(MTT) method; mitochondrial membrane potential (MMP) was detected by confocal microscopy and flow cytometry. RESULTS: Cultured SH-SY5Y cells were exposed to 16-64 mmol/L sodium azide for 1 hour, the mitochondrial complex IV activity decreased dose-dependently. MTT absorbance decreased does- and time-dependently in cultured nerve cells treated by 16-128 mmol/L sodium azide for 1-8 hours. After the treatment of 16 mmol/L sodium azide for 1 hour, both the fluorescence intensity of MMP and normal cell events reduced. Decrease of MMP was significant especially in cell processes. CONCLUSION: Sodium azide induced the impairment of mitochondrial energy synthesis in the cultured nerve cells which is an important cause in cell death.

Cell Death↗
PubMed2000

[FT-Raman spectroscopic investigation on stomach cancer].

FT-Raman spectroscopy was used to investigate 40 normal and malignant tissues from stomach. Statistic analysis shows that the bands related to OH, NH, C=O stretching and H-O-H bending are stronger in malignant tissues. This phenomenon suggests that the hydrogen bonding systems among water and protein vary in malignant tissues.

Humans↗
PubMed2000

[Orientation of H-bonds revealed by cryogenic FTIR spectroscopy].

We propose a new way to reveal structural arrangement of hydrogen bond network using FTIR spectroscopy. When KBr pellet and fluorolube mull methods are used to prepare samples for IR measurements, the resultant spectra sometimes show significant differences, sometimes not. The reason is unknown. We use cryogenic FTIR spectra to prove pressure effect accounts for spectral variation in different sampling process. The sensitivity of the FTIR spectra to external pressure is related to the three-dimensional arrangement of hydrogen bonding network in the sample. When hydrogen bonds are in one plane, they can not resist external pressure applied perpendicular to that plane. Consequently, large differences appear between the spectra obtained using KBr pellet and fluorolube mull methods. On the other hand, when hydrogen bonds orientate towards various directions, the hydrogen bonding system can resist pressure from any directions. Thus, the FTIR spectra exhibit little variation using different sampling methods. We propose that the spectral variation obtained using above methods is a criterion to judge whether the hyrogen bonds orientate toward various directions in three-dimensional space or not.

Cholesterol↗
PubMed2000

[The determination of Niphensamide by UV spectrophotometry].

In this paper Uv spectrophotometry was used to determine Niphensamide. In this method, 372 +/- 1 nm was selected as a criterion for quantitative determination, and the absorptivity. E1 cm 1% = 556. The results indicated that a better linear-relationship between the absorbance and the concentration of the sample. When the concentration was ranged from 0.5 mg.L-1 to 40 mg.L-1, the correlation coefficient was 0.9999, and the mean rate of recovery reached 99.8%.

Molluscacides↗
PubMed1999

Time-resolved fluorescence immunoassay of thyroxine in serum: immobilized antigen approach.

With T(4)-bovine IgG as a solid-phase antigen, we have developed a direct competitive-type immunoassay for serum total thyroxine (TT(4)), which depends on the competitive distribution of europium-labeled anti-T(4) monoclonal antibody between solid-phase-bound T(4) and the T(4) in the sample or standard. The captured fraction of the tracer was measured after a dissociation-enhancement step. Four different T(4) protein conjugates were synthesized, of which T(4)-bovine IgG was selected as the most favorable for the preparation of solid-phase antigen. The sensitivity was 3.5 ng/ml with a sample volume of 20 microl. T(4) values obtained by this procedure agreed well with those obtained by RIA (r = 0.967, n = 38) and EG&G Wallac TRFIA (r = 0.926, n = 64). All other quality criteria was also fulfilled with respect to precision, accuracy, and dynamic range.

Animals↗