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Biomedical subjects

Z Xu

Publications and source records attributed to Z Xu.

At least 271 records · Page 15Linked to original sources
PubMed1999

[Reconstitution and protection of murine hematopoiesis by second transplantation with bone marrow cells containing mutant human DHFR gene from primary generation murine].

OBJECTIVE: To observe the effect of donor murine bone marrow, which was transfected in vivo with mutant hDHFR gene, on the reconstitution and protection of hematopoiesis of lethally irradiated recipient mice. METHODS: Mice bone marrow transduced in vivo with mutant hDHFR gene were used for transplantation. After whole bodily irradiated (8.5-9.0 Gy) and then transplanted with the transduced marrow, the recipients were treated with methotrexate (4 mg/kg twice a week for the first week; and then 10 mg/kg twice a week). The survival rate and blood picture of the recipients as well as the integration and expression of hDHFR gene were studied by using PCR and Southern blotting. RESULTS: The hematopoiesis of the recipient mice could be reconstituted and protected from lethal toxicity of high dose methotrexate. It was confirmed that hDHFR gene was integrated into hematopoietic cell as well as some tissues genomic DNA and expressed successfully in the recipients. CONCLUSION: Donor mice bone marrow transfected with mutant hDHFR gene can effectively reconstitute and protect hematopoiesis in lethally irradiated recipient mice.

Animals↗
PubMed1999

[MAL gene is down-regulated substantially in human esophageal cancer].

OBJECTIVE: To investigate the status of expression of MAL gene in human esophageal cancer. METHODS: Expression of MAL gene was analyzed by Northern blot and/or RT-PCR in 41 pairs of human esophageal cancer tissues and matched adjacent normal mucosa, and three human esophageal cancer cell lines EC109, EC8712 and EC9706. MAL gene was analyzed by PCR in the three esophageal cancer cell lines. RESULTS: MAL gene expression was down-regulated substantially or barely detectable in 93% (38/41) of human esophageal cancer tissues while expressed at high level in all matched adjacent normal esophageal mucosa. In all 3 human esophageal cancer cell lines, expression of MAL gene was not detectable. PCR analysis showed that the MAL gene fragment analyzed was intact in the three esophageal cancer cell lines. CONCLUSION: Down-regulation of MAL gene expression is of frequent occurrence in human esophageal cancer.

Down-Regulation↗
PubMed1999

[The proper opportunity of surgery for rectal cancer after preoperative adjuvant chemotherapy].

OBJECTIVE: To discuss the proper opportunity of surgery for rectal cancer after preoperative intra-arterial chemotherapy. METHODS: Preoperative chemotherapy was performed on 27 rectal cancer cases at Dukes stage B and C. The therapy comprised of arterial infusion of 5-fluorouracil 600 mg/m(2), mitomycin 15 mg/m(2) and epirubicin 30 mg/m(2) for one course. Miles' or Dixon's operation was carried out 7 to 10 days later. The effects of chemotherapy were evaluated. Dynamic changes of proliferating cell nuclear antigen (PCNA) expression were studied by immunohistochemistry on paraffin-embedded sections. RESULTS: Hematochezia was remitted in 19 cases. Histologically, the effects of chemotherapy were considered as slight, moderate and marked in 9, 15 and 3 cases, respectively. Side effects were slight and recovered in 4 days. There was a high expression of PCNA in rectal cancer. On the 7th to the 10th day, proliferating index was significantly higher than that of before chemotherapy (46.48 +/- 10.62)%, P < 0.05. CONCLUSIONS: Preoperative adjuvant chemotherapy plays a role in the treatment of resectable rectal cancer. It is suggested that radical surgery should be carried out 5 to 6 days after intra-arterial chemotherapy.

Adult↗
PubMed1999

[Timing changes of apoptosis and proliferating cells nuclear antigen after intra-arterial infusion chemotherapy for rectal cancer].

OBJECTIVE: To investigate the timing changes of apoptosis (APO) and PCNA after intra-arterial infusion chemotherapy for rectal cancer. METHODS: Twelve patients were subjected to percutaneous arterial femoralis catheterization by Seldinger's technique and infusion of anti-cancer drugs: 5-fluorouracil (5-Fu) 600 mg/m(2), mitomycin (MMC) C5 mg/m(2) and epirubicin (EDR) 35 mg/m(2). The biopsy of rectal tumor tissues was done before chemotherapy, and 24, 48, 72 hours and 7-10 days after chemotherapy. Apoptotic cells were examined by terminal-deoxynucleotidyl-transferase (TdT)-mediated dUTP-fluorescein and labeling. The expression of proliferating cells nuclear antigen (PCNA) was detected by immunohistologic staining. RESULTS: The apoptosis index (AI) of rectal cancer cells before chemotherapy, and 24, 48, 72 hours, and 7-10 days after chemotherapy was 6.84 per thousand, 19.53 per thousand, 13.15 per thousand, 11.85 per thousand and 11.86 per thousand respectively. The PCNA index (PI) was 45.56%, 40.68%, 39. 87%, 51.28% and 63.75% before and 24, 48, 72 hours, and 7-10 days after chemotherapy. CONCLUSIONS: Intra-arterial infusion chemotherapy not only induced apoptosis effectively, but also inhibited temporarily tumor cells proliferation in patients. The curative surgical treatment should be performed as soon as possible after chemotherapy.

Adult↗
PubMed1999

[Relationship between insulin-like growth factor II and prognosis of colorectal cancer].

OBJECTIVE: To investigate the relationship between insulin-like growth factor II (IGF-II) and prognosis of colorectal cancer. METHODS: One hundred and forty-two colorectal cancer patients were enrolled. In colonoscopic biopsy specimens, the expression of IGF-II and PCNA were detected immunohistochemically, while TUNEL technique was used to detect apoptosis. All patients were followed up, and disease-free survival (DFS) and overall survival (OS) rate were calculated. RESULTS: The expression level of IGF-II was significantly higher in colorectal cancer than in normal colorectal mucosa. A correlation was observed between more IGF-II expression, high PCNA labeling index, and apoptotic index was demonstrated. Patients with lower expression level of IGF-II had higher DFS and OS. Multivariate analysis by means of the Cox proportional-hazards model revealed that the expression level of IGF-II was an independent prognostic predictor in colorectal cancer patients. CONCLUSION: The expression level of IGF-II is a new prognostic predictor for colorectal cancer.

Adenocarcinoma↗
PubMed1999

[An analysis of nutritional and harmful components of vegetables grown in plastic greenhouses].

OBJECTIVE: To study the changes in nutritional and harmful components of vegetables grown in plastic greenhouses. METHODS: In plastic greenhouses, microclimate and air concentrations of carbon monoxide, carbon dioxide, fluoride and respirable particulate were measured, and chlorophyll, total sugar, crude fiber, nitrite, fluoride, arsenic and some mineral elements in vegetables were determined as compared with those grown in the open-air fields. RESULTS: Greenhouse appeared a lower wind speed and darker illumination. Contents of chlorophyll a an b, total chlorophyll, reduced vitamin C, crude fiber in vegetables grown in greenhouse all were lower than those grown in open-air fields. Contents of potassium, calcium, magnesium, iron, zinc, copper and phosphorous were all lower in the vegetables grown in greenhouse than those grown in open-air fields. The contents of chlorophyll reducing Vitamin C. CONCLUSION: Lower wind speed and inadequate illumination in greenhouse affected photosynthesis and uptake of water in vegetables causing changes in their nutritional components. But, no contamination of burning coal was found in vegetables grown in greenhouse.

Air Pollutants↗
PubMed1999

[Comparison of subclinical infection rates between vaccinated group with type I inactivated vaccine against hemorrhagic fever and controls].

OBJECTIVE: To compare subclinical infection rate in the vaccinated group with type I inactivated vaccine against hemorrhagic fever with renal syndrome (HFRS) with that in the controls and to understand its enhancement. METHODS: A trial field was selected in Jiande County, Zhejiang Province during July 1974 to November 1997. Paired-sera before and after vaccination were collected from 401 vaccinee and 360 controls, respectively. Serum titer of indirect immunofluorescent IgG antibody (IFAT) against HFRS was detected for each of them, and its cut-off value depended on the distribution of serum antibody titer in the second determination in the controls, which could be used to evaluate subclinical infection before vaccination. RESULTS: There was no significant difference in subclinical infection between those with positive and negative IFAT before vaccination, with different cut-off values for identifying subclinical infection. In both vaccinated and control groups with negative IFA before vaccination, subclinical infection rate was 7.62% in the controls, and 2.17% and 1.63% in the vaccinated ones, with cut-off values of 1:160 and 1:320, respectively, significantly different from that in the former. Subclinical infection rate was 11.38% and 6.78% in the vaccinated ones, as cut-off values of 1:20 and 1:40, respectively, without significant difference from the controls. CONCLUSION: No increase in subclinical infection in the vaccinated group with type I inactivated vaccine against HFRS was found.

Adolescent↗
PubMed1999

[A study on immunogenicity and safety of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome].

OBJECTIVE: To study side effects and effectiveness of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome in population of a randomized controlled field trial. METHODS: Serum indirect immunofluorescent antibody in 167 persons and neutralization antibody (types I and II) in 69 persons, who received three-dose vaccine, were determined two weeks after immunization, and side effects in 657 vaccinees were observed within 72 houses after immunization. RESULTS: Serum positive conversion rate of indirect immunofluorescent antibody was 99.04% (166/167) with GMT of 24.51 +/- 2.06. Serum positive conversion rate of neutralization antibody was 100% (69/69), 91.30% (63/69) for types I and 88.41% (61/69) for type II, respectively. GMTs for type I and II neutralization antibody were 18.27 +/- 2.21 and 12.47 +/- 2.16, respectively. Side effects at local site vaccinated of the body and temperature rising could be seen in 1.48% and 0.36% of the vaccinees, respectively. No severe side effect and abnormal reaction was found in vaccinees on the field. CONCLUSION: Immune response to bivalent inactivated vaccine against hemorrhagic fever with renal syndrome was satisfactory with slight side effect.

Adolescent↗
PubMed1999

[The expression of integrin alpha5beta1 and transforming growth factor-beta in pulmonary fibrosis of rat].

OBJECTIVE: To study the roles of integrin alpha(5)beta(1) played in rat pulmonary fibrosis. METHODS: The dynamic changes of fibronectin (FN), FN receptor alpha(5)beta(1), and TGF-beta were analysed in bleomycin-induced rat pulmonary fibrosis by using immunohistochemical technique. Northern blot analysis and immunocytochemistry techniques were performed in order to detect the expression of alpha(5)beta(1), FN mRNA and their relevant proteins in cultured rat pulmonary fibroblasts (PFbs) after administration of TGF-beta1. RESULTS: (1) A strong positive reaction with anti-integrin alpha(5)beta(1) was seen in the pneumocytes, endothelial cells and proliferated mesenchymal cells on the 1st to 3rd day after bleomycin. The positive signals for integrin alpha(5)beta(1) were apparent mainly in those proliferated interstitial cells with fibroblast and myofibroblast differentiation 7 days after bleomycin treatment. Changes in FN were similar to that of the integrin alpha(5)beta(1). (2) Expression of alpha(5)beta(1), FN mRNAs and their relevant proteins was increased in rat PFbs after TGF-beta1 administration. CONCLUSIONS: Integrin alpha(5)beta(1) played a key role in inducing the activation, proliferation and differentiation of PFbs, causing an increase of extra-cellular matrix synthesis during pulmonary fibrogenesis.

Animals↗
PubMed1999

[Expression of vascular endothelial growth factor and tumor angiogenesis correlates with biological behaviors of nasopharyngeal carcinoma].

OBJECTIVE: To study the correlation between tumor angiogenesis and biological behaviors of nasopharyngeal carcinoma(NPC). METHOD: Angiogenesis was assessed by the microvessel dinsity(MVD) and expression of vascular endothelial growth factor(VEGF) was detected using immunohistochemical S-P method. Paraffin-embedded specimens from 65 patients with NPC and 15 with benign nasopharyngeal tumors, 15 with tumor-free nasopharyngeal mucosac were detected. RESULT: Expressions of VEGF and MVD in NPC group were higher than that of nonmetastic carcinoma group. The relationship between expressions of VEGF and MVD and the clinical staging present statistic significance. CONCLUSION: MVD and expression of VEGF are highly correlated with biological behaviors of NPC, which may serve as a parameter for determining tumor biological metastatic potential and prognosis. Angiogenesis inhibitors might be helpful in preventing NPC from metastasis.

Adult↗
PubMed1999

[Bilateral large vestibular aqueduct syndrome (7 cases reported)].

OBJECTIVE: To explore the CT features and the auditory threshold in patients with bilateral large vestibular aqueduct syndrome. METHOD: The diameter of vestibular aqueduct in CT and the auditory threshold in each ears of seven patients were measured. RESULT: Asymmetry of the enlarged vestibular aqueduct was found in all patients of whom the side the vestibular aqueduct enlarged was found having a greater hearing loss than the other side in the same patient (paried t-test; P < 0.05). CONCLUSION: The measurement of vestibular aqueduct may be useful in determining the prognosis of patients with large vestibular aqueduct syndrome.

Adolescent↗
PubMed1999

[Dynamic changes in the expression of type VI collagen in mice with schistosomal liver fibrosis].

AIM: To clarify the dynamic changes in type VI procollagen mRNA expression and collagen content in mice with schistosomal liver fibrosis. METHODS: Northern blot hybridization and immunohistochemical technique. RESULTS: The expression of alpha 1(VI) procollagen mRNA measured by Northern blot hybridization in the liver of schistosome infected mice was elevated significantly at 8 wk post infection, peaked at 10 wk pi, slightly decreased at 12-16 wk pi, and sustained at high levels until 20 wk pi. Immunohistochemical assay revealed that the staining pattern of type VI collagen first appeared in the walls of central veins and liver sinusoids at 8 wk pi, then extended gradually to the egg granuloma and the portal tract, within and surrounding the egg granuloma to form dense reticular septum at the 12, 16 and 20 wk pi, respectively. The VI collagen content as indicated by the intensity of stain peaked at 16 wk pi. CONCLUSION: Both the expression of alpha 1(VI) procollagen and the content of collagen VI were significantly increased in the liver of mice with early schistosomal fibrosis, suggesting that the type VI collagen detection might be of importance for evaluating the intensity of schistosomal liver fibrosis.

Animals↗
PubMed1999

[Effect of decompression of blood vessel on vascular compressive tinnitus].

OBJECTIVE: To evaluate the diagnosis and surgical indications of vascular compressive tinnitus. METHOD: We searched carefully the possible focus causing vascular compressive tinnitus around VIII cranial nerve in cerebellopontine angle via retrosigmoid sinus approach under microscope in 40 cases. The responsible blood vessels and synechia focus was separated and one piece of auto-musculomembrane was put between blood vessels and the nerve. RESULT: We had 38 cases of operation. All of them had artery compression on the surface of VIII cranial nerve, 6 of them had arachnoid synechia. After operation, the symptoms of tinnitus disappeared thoroughly. Of them 4 cases with vertigo recovered also. Recurrences were found in 2 cases in the follow-up survey which last 6 monthes to 7 years and 2 monthes. CONCLUSION: Surgical treatment of neurovascular decompression for vascular compressive tinnitus via retrosigmoid sinus approach has positive therapeutic effect as long as the diagnosis is correct.

Adult↗
PubMed1999

[Synthesis and distribution of type IV collagen in mice testes].

OBJECTIVE: The variations of the synthesis and distribution type IV collagen in the testes of young, adult, and old mice were studied. METHODS: Biotin-avidin DCS system indirect immunofluorescence technique and in situ hybridization method were used. RESULTS: Sertoli cell could synthesize type IV collagen. Type IV collagen was present in the basement membrane of seminiferous tubules in mouse testis. Type IV collagen mRNA signal was seen in the Sertoli cells. The content of type IV collagen and type IV collagen mRNA peaked at day 15, and then declined successively to adult value and the aged value. CONCLUSIONS: The results suggest that the extracellular matrix of testis might play an important role in the process of spermatogenesis.

Age Factors↗
PubMed1999

[Posterior sigmoid sinus approach glossopharyngcal neurotomy in the surgical treatment of glossopharyngeal neuralgia].

OBJECTIVE: To appraise the diagnotic criteria and surgical indications of glossopharyngeal neuralgia. METHODS: Under 2% lidocaine local infiltration anesthesia, retrosigmoid sinus approach was adopted to find the cerebellopontine angle. The possible focus causing glossopharyngeal neuralgia was searched carefully under the microscope and the glossopharyngeal nerve cut. RESULTS: Only 2 cases had artery compression on the surface of glossopharyngeal nerve during the operations. Besides, all of them had arachnoid synechia around the glossopharyngeal nerve. The symptoms of glossopharyngeal neuralgia disappeared thoroughly after operations. Three cases having histories of bradycardia, arrhythmia or hypotension recovered from their diseases postoperatively. Recurrent symptoms were not found in the follow-up survey which lasted 8 months to 6 years, with an average of 3.7 years. CONCLUSION: Glossopharyngeal neurotomy via retrosigmoid sinus approach has positive therapeutic effect as long as the diagnosis is correct.

Adult↗
PubMed1999

[SERS of bilirubin and its complexes].

SERS spectra of bilirubin and its complexes were determined in Ag sol by the technique of the connection between NIR-FT-Raman and SERS. The spectra showed that this kind of biological complexes, which is closely related to gallstones, differ in coordination pattens and adsorptive orientation as well. The reason why the black-pigment gallstone exhibits that peculiar dark color was also given from the coordination-chemistry point of view.

Bilirubin↗