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Biomedical subjects

Z Xu

Publications and source records attributed to Z Xu.

At least 325 records · Page 18Linked to original sources
PubMed1998

[Risk of lung cancer among iron and steel workers in Anshan, China--case-control study].

A case-control interview study on 610 lung cancer patients and 959 controls was conducted among male workers in Anshan Iron-steel Complex. After adjusting for non-occupational risk factors, such as smoking, pulmonary disease, family history of cancer and the consumption of fruit, risks for lung cancer were significantly higher in workers engaged in smelting and rolling (OR = 1.5, 95% CI = 1.1-2.2), in the fire-resistant brick factory (OR = 2.9, 95% CI = 1.4-5.9), in general loading (OR = 2.5 95% CI = 1.0-6.1), and in coking (OR = 3.4, 95% CI = 1.4-8.5) for 15 or more years. Significant dose-response was observed for exposure to total dust and B[a]P, but not for specific chemical components of dust. The lung cancer risk increased 40% in iron and steel workers with long term occupational exposure.

Adult↗
PubMed1998

[Calculating method for the necessary lamps and sterile rate in a tube-shaped ultraviolet air washer].

It has much more advantage to use the cylindric ultraviolet air washer than to use the ordinary ultraviolet lamps. There was a calculation method for determining necessary lamps in a rectangled ultraviolet air washer, but it had a limiting condition. This paper developed two calculating methods for determining necessary lamps and its sterile rate in a tube-shaped ultraviolet air washer. The sterile rate can be extracted with any parameter. Necessary lamps can also be extracted with its sterile rate.

Air Microbiology↗
PubMed1998

[Supraglottic horizontal laryngectomy for supraglottic carcinoma].

OBJECTIVE: To evaluate the therapeutic results of supraglottic horizontal laryngectomy (SHL) for T1 and selected T2, T3 and T4 supraglottic carcinoma. METHODS: One hundred and seven patients undergone SHL during the period of 1979 through 1991 were reviewed retrospectively. All patients were followed up for at least 5 years. RESULTS: The 5 year-survival rate of 6 cases in stage I, 24 cases in stage II, 53 cases in stage III, and 24 cases in stage IV was 100.0%, 83.3%, 71.7% and 41.7%, respectively. Of the 102 patients, 92.2% were decannulated, and 91.6% of all patients achieved satisfactory recovery of phonation. CONCLUSION: SHL is a reliable surgical approach for selected supraglottic carcinoma, even for some advanced lesions, provided the tumor has not extended below the ventricle. The upper neck dissection can be used as an exploratory measure. For N0 neck patients with supraglottic cancer, comprehensive neck dissection is not invariably performed to avoid overtreatment.

Adult↗
PubMed1998

[Cervical lymph node metastasis: CT, ultrasound versus physical palpation].

OBJECTIVE: To evaluate the accuracy of CT, ultrasonography and manual palpation in the diagnosis of cervical lymph node metastasis and to identify the value of CT and ultrasound in the diagnosis of occult cervical lymph node metastasis. METHODS: Sixty patients (74 sides) were studied double-blindedly by CT and ultrasonography prior to cervical lymphadenectomy, and the results were correlated with histo-pathologic findings. RESULTS: According to histologic examination of the dissected specimens, in 56 of 74 sides there were cervical lymph node metastases, 46 of the 56 sides with metastatic nodes were diagnosed by manual palpation(sensitivity, 82.1%; specificity, 83.3%; accuracy, 82.4%). However, lymphnode metastases in 53 sides were revealed by CT(sensitivity, 94.6%; specificity, 94.4%; accuracy, 94.6%), i.e., CT discovered 70% of the occult metastatic nodes in this series. Lymph node metastases were diagnosed accurately in 51 sides by ultrasonography (sensitivity, 91.1%; specificity, 94.4%; accuracy, 91.9%), and 50% of the occult metastatic nodes were found by ultrasound. CONCLUSION: CT, ultrasound examinations are superior to physical palpation in ascertaining cervical lymph node metastasis, as 50%-70% of the occult cervical metastatic nodes can be diagnosed.

Adolescent↗
PubMed1998

[Immunogenicity and efficacy trials of live attenuated hepatitis A vaccines].

OBJECTIVE: To study two live vaccines, H2 and LA-1 strains, both attenuated in growth on human diploid cell culture at lower temperature (32 degrees C). METHODS: Randomized, controlled trials were performed among half million children. 135,340 children were divided into vaccine or control groups by individual and 360,012 by cluster. Those susceptibles with negative anti-HAV were bled at 2-6 months after the vaccination and blood test for anti-HAV. RESULTS: 37 hepatitis A cases were found in the control group. The protective efficacy of the two vaccines was 100%, and the 95% lower confidence limit (one sided) of combined efficacy of the two vaccines was 92.1%, that was comparable with the two inactivated vaccines produced by SmithKline beecham or Merck Sharp Dhome. CONCLUSION: The vaccines are safe, and the seroconversion to H2 strain (10(7.0) TCID50) and LA-1 strain (10(6.75) TCID50) is 94.87% and 83.16% respectively.

Child↗
PubMed1998

[Salvage surgery for nasopharyngeal carcinoma after irradiation failure].

OBJECTIVE: To study the salvage surgery for nasopharyngeal carcinoma after irradiation failure. METHODS: One hundred and twenty-one full-dose-irradiation-uncontrolled cases of nasopharyngeal carcinoma had undergone salvage surgery since 1965 till 1992, in which 41 had primary lesion and 80 neck lesion. All patients received radiation before surgery with the dose of 60Gy-145Gy. The patient selection for this report limited to those with recurrent tumors at the primary sites with no apparent bony involvement and no cranial nerve palsy, or cases with resectable neck recurrences. RESULTS: It showed that palatal fenestration was the best choice of approach for recurrent tumors located at the vault of the nasopharyngeal cavity. When the tumor invaded the parapharyngeal space or, owing to the after-effect of radiotherapy, the patient presented with severe occlusion of the mandible, we preferred the lateral approach through partial mandi-bulectomy. The lateral rhinotomy was only indicated for cases with tumor remnant at the posterior nares. Lymph node excision was performed for cases with single movable node on the neck, and RND for the cases with multiple nodes. The complication rate of after surgery was low (10%), considering the heavy dose of irradiation. The three- and five-year survival rate were 49% (59/121) and 38% (38/100) respectively. CONCLUSION: It suggests that the surgery should be considered as a salvage procedure for cases of nasopharyngeal cancer after irradiation failure. Because of high rate of distant metastasis (62 cases or 45% died after surgery), chemotherapy or other measures should be adopted after local treatment.

Adolescent↗
PubMed1998

[Analysis of constituents of essential oils from flos Magnoliae].

The constituents of essential oils from Magnolia biondii, M. denudata and M. sprengeri were analysed by GC-MS qualitatively and GC quantitatively. Ninety-one compounds of M. biondii, seventy-one compounds of M. denudata and eighty-eight compounds of M. sprengeri were identified at rates of 97.37%, 97.66% and 95.68% respectively.

Acyclic Monoterpenes↗
PubMed1998

[Effect of guchijianzhou decoction on antioxidation in aged mice].

OBJECTIVE: To observe the antioxidation effect of Guchijianzhou decoction in aged mice. METHODS: The Guchijianzhou decoction was given to aged mice by gastric intubation and compared with a group of young mice and a group of aged mice giving tape water. The LPO, SOD and CAT level were examined. RESULTS: There were significant differences as the experimental group was campared with the control groups. CONCLUSION: The results show that Guchijianzhou decoction is effective in antioxidation and against danage by free radical. It can reinforce antibacterial function and is benificial in the restoration of periodontal health.

Aging↗
PubMed1998

[Functional changes of forelegs of rats after C6 and C8 nerve roots resection: experimental study].

OBJECTIVE: To find new nerve roots as dynamic source, we observed the effect of C(6) and C(8) resection on the function of forelegs of roots. METHOD: Considering the relationship between C(6) and biceps brachii muscle, C(8) and flexor digitorum profundus muscle, we resected C(6) and C(8) nerve roots of right side as the experimental side and compared with the left side. The position, pace, appearance of ulcer were observed on the foot and the phenomena of self-injury were seen regularly. The EMG and tensile strength of biceps brachii and flexor digitorum profundus muscles were measured immediately at two weeks and four weeks after operation. RESULT: The position of two sides of the rats was symmetrical. There were no limp, ulceration and phenomena of self-injury. Normal wave figure in EMG was noted in the experimental side. There was no significant difference in t test in EMG wave amplitude, maximum tetanized systole tensile strength and duration of isometric contraction. CONCLUSION: C(6) and C(8) nerve roots resection has no obvious influence on function of the leg.

Animals↗
PubMed1998

[An experimental research of recombinant human epidermal growth factor on corneal wound healing].

OBJECTIVE: To investigate the effects of recombinant human epidermal growth factor (rhEGF) eye drops on corneal wound healing. METHODS: Twenty-four white rabbits were randomly divided into 4 groups, 6 rabbits 12 eyes each. Anterior keratectomy of 8 mm in diameter and 1/3 cornea in thickness was performed on each eye. Each of the following concentrations of rhEGF: 1, 10, 100 microg/ml eye drops or normal saline (control) was applied four times daily for a week respectively for one group. The wound area was determined by computer imaging analysis. RESULTS: The mean epithelial healing rate of rhEGF 1, 10, 100 microg/ml groups was 9.31, 9.96, 9.31 mm(2)/day respectively, significantly greater than 8.11 mm(2)/day of the control group. The action of rhEGF of 10 microg/ml was somewhat better than that of 1 or 100 microg/ml, and no significant difference was noticed among the three rhEGF groups. Moderate inflammation and corneal neovascularization were induced in the rhEGF 100 microg/ml treated group. CONCLUSION: rhEGF 1 - 10 microg/ml can accelerate corneal wound healing in the rabbit with no adverse side-effects. It may be used to treat serious corneal trauma and ulcer clinically.

Animals↗
PubMed1998

[The uptake characteristics of 5-fluorouracil in the Caco-2 model system].

The uptake characteristics of 5-fluorouracil in the Caco-2 model system were studied. The uptake of 5-fluorouracil was determined at different pH and concentrations, and in the presence of various inhibitors. The results indicated that the uptake of 5-fluorouracil was the best at pH 6.0. The rate of uptake was saturable with a Km of 24 mmol.L-1, and a Vmax of 20.9 nmol.min-1.mg-1 protein. The uptake was inhibited by noncompetitive inhibitors such as NaCN, ouabain, and dipyridamole. The uptake was also inhibited competitively by analogous compounds such as uracil, thymine, and uridine (but not by hypoxanthine). In conclusion, the evidence suggests that 5-fluorouracil was transported by uracil carrier in Caco-2 cells.

Antimetabolites, Antineoplastic↗
PubMed1998

[Experimental study on detection of Schistosoma japonicum 5D gene by using PCR].

AIM: To search for an effective method to diagnose the schistosomiasis and evaluate the effect of treatment. METHODS: A PCR protocol was designed to detect the Schistosoma japonicum 5D gene encoding an immunogenic miracidial antigen in cercariae, eggs and adult worms. RESULTS: Specific amplification of a 262 bp DNA fragment was achieved by using PCR and a 165 bp DNA fragment by using nest-PCR in cercariae, adult worms and eggs of Schistosoma japonicum. After 40 cycles by PCR, the product could be detected by agarose gel electrophoresis. This PCR protocol was able to detect as few as a single cercariae, a single egg or a pinpoint-sized tissue of adult S. japonicum. Nest-PCR and oligonucleotide probe hybridization could further increase the sensitivity. No specific PCR product was obtained with DNA from human leucocyte, Escherichia coli, Bacillus proteus vulgaris, Streptococcus faecalis and Salmonella typhi. CONCLUSION: The sensitivity and specificity of this PCR protocol are satisfactory.

Animals↗
PubMed1998

[Histological changes of Cysticercus cellulosae under the action of proteinase of Omphalia lapidescens in vitro].

AIM: For the purpose of finding an anthelmintic with high efficacy, low toxicity and low cost, especially from the Chinese traditional medicines. METHODS: Forty Cysticercus cellulosae were separately incubated with proteinase from artificially fermented Omphalia lapidescens for 2 h, 4 h and 8 h, and then examined for histological changes by light microscopy and compared with those of proteinase from natural dry Omphalia lapidescens after similar treatment. RESULTS: Cysticercus cellulosae were morphologically and structurally impaired after exposure to the action of proteinase of Omphalia lapidescens, and the degree of impairment was proportionally paralleled to the duration of treatment. CONCLUSION: The anti-cysticercus effect of proteinase of Omphalia lapidescens and the homogeneity of proteinases from artificially fermented and natural Omphalia lapidescens were confirmed.

Animals↗
PubMed1998

[Application of improved western blot method in diagnosis of cysticercosis].

AIM: To evaluate the diagnostic value of four specific antigens from cDNA of Cysticercus cellulosae. cC1, cC2, and cP1 and cH1 (28 kDa, 18 kDa, 14 kDa and 34 kDa), mixing in equal proportions for the diagnosis of cysticercosis. METHODS: Taking the FP (fusion proteins) as antigen to make IWB (improved Western blot) analysis basing on the detection of antibody responses against FP, and making ELISA/IHA-crude antigen(CA) analysis. They were evaluated comparatively while using 107 infected sera of cysticercosis cases, 40 infected sera of clonorchiasis cases, 24 infected sera of echinococcosis cases and 34 sera of healthy persons. The FP are encoded by cDNAs of beta-galactosidase-specific antigens of Cysticercus cellulosae isolated from the cDNA library. RESULTS: 94(87.9%) sera from 107 cysticercosis cases recognized FP in IWB and could not cross-react with the sera of echinococcosis cases, clonorchiasis cases and healthy persons, the specific rates were 100%, whereas ELISA, IHA using CA were 84.1% and 74.8%, respectively and could cross-react with the sera of echinococcosis cases, the false positive rates were 2.5% and 12.5% respectively; CA-ELISA/IHA could cross-react with the sera of clonorchiasis patients, the false positive rates were 8.3% and 16.7%, respectively; and they could also cross-react with the sera of healthy persons, the false positive rates were 8.8% and 11.8%, respectively. CONCLUSION: The recombinant FP used in the immunodiagnosis of cysticercosis is specific and sensitive.

Animals↗