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Biomedical subjects

W Dong

Publications and source records attributed to W Dong.

At least 37 records · Page 2Linked to original sources
PubMed2001

[UV photolysis mechanism of CCl4 and CHCl3 in water].

The photolysis mechanism of CCl4 and CHCl3 in water was studied by using transient absorption spectra. The results showed that aqueous CCl4 was dissociated into CCl3 and Cl radicals by 248 nm laser, and CHCl3 was dissociated into CHCl2 and Cl radicals after adding C6H6. The radicals CCl3 and CHCl2 were able to react with O2 to form CCl3O2 and CHCl2O2 respectively, or to form C2Cl6 and C2H2Cl4 without O2. The rate coefficients of some reactions were obtained.

Carbon Tetrachloride↗
PubMed2001

[Preliminary assessment of articles reporting cancer diagnostic tests].

OBJECTIVE: To improve the quality of papers on clinical diagnostic tests. METHODS: Articles of diagnostic tests published in the Chinese Journal of Oncology in the year 1990 were surveyed by cluster sampling method. RESULTS: In the 23 articles surveyed, immunoassays constituted the largest category, accounting for 39.1% (9/23), followed by biochemical markers and radiological tests, accounting for 17.4% (4/23) and 13.0%(3/23), respectively. Of the 23 articles, 19 (82.6%) employed a well-defined "gold standard", 14 (60.9%) correctly calculated sensitivity and specificity. The interpretation of the test was stated to be "blind" in only 39.1%(9/32). In only one paper were all the seven methodologic criteria adhered. Less than 60% of the articles followed more than four of the seven methodologic criteria, and in 2 articles only one of the criteria was met with. CONCLUSION: Although due attention has been paid to the methodologic criteria of assessing diagnostic tests, the quality of the articles surveyed needs to be improved.

Diagnostic Tests, Routine↗
PubMed2001

[Superoxide dismutase and cytokines in otitis media with effusion].

OBJECTIVE: To study the role of superoxide dismutase (SOD) and cytokines in the pathogenesis of secretory otitis media(SOM). METHOD: The content of SOD, interleukin-6(IL-6), interleukin-8(IL-8) and tumor necrosis factor alpha (TNF-alpha) in blood plasma and middle ear effusion (MEE) were measured in 64 (90 ears) patients respectively. RESULT: SOD, IL-6, IL-8 and TNF-alpha were found in 88.9%, 86.8%, 81.5% and 74.6% of MEI respectively. SOD, IL-6, IL-8 and TNF-alpha of blood plasma in SOM group were higher than those in normal control group (P < 0.05). The concentration of SOD, IL-6, IL-8 and TNF-alpha MEE was remarkably higher than that in blood plasma (P < 0.01). It revealed that the shorter the course, the higher the concentration of IL-6 or IL-8 in MEE (P < 0.01, or P < 0.05), and the longer the course, the higher the concentration of SOD or TNF-alpha in MEE (P < 0.01, P < 0.05). IL-6 and IL-8 concentration of MEE in serous fluid group was remarkably higher than those in the mucous fluid group (P < 0.01, P < 0.05), and the concentration of SOD and TNF-alpha of MEE in the mucous fluid group was higher than that in the serous fluid group (P < 0.01, P < 0.05). SOD Level of MEE was positively correlated with TNF-alpha (r = 0.587, P < 0.01). CONCLUSION: SOD, IL-6, IL-8 and TNF-alpha might be important mediators in MEE secretion in SOM. IL-6 and IL-8 might participate in the defensive reaction of organism during the early stages of SOM. SOD and TNF-alpha might be closely related to the persistence of SOM, and might be mediators of mucin secretion in SOM.

Adolescent↗
PubMed2001

[Acoustic analysis in patients with trauma to unilateral cricoarytenoid joint by computer technique].

OBJECTIVE: To investigate the acoustic characteristics of unilateral cricoarytenoid joint trauma and evaluate the effect of acoustic analysis technique on the diagnosis and treatment of this disease. METHOD: The voice signals of sustained vowel [a] were measured using a micro-computer with Dr. Speech software in 50 healthy adults and 30 patients with unilateral cricoarytenoid joint trauma. The acoustic parameters (jitter, shimmer and NNE) and spectrographic characteristics (harmonic waves, formants and noise) were analyzed. The acoustic changes before and after the treatment of arytenoid motion were observed and compared. RESULT: All acoustic parameters were significantly increased in trauma of unilateral cricoarytenoid joint. The pathologic spectrograph showed decrease or loss of harmonic waves and formants, and increase of noise, in middle and high frequencies. There was a relationship between NNE and the position of the vocal cord. After the treatment of arytenoid motion, 33% patients were cured and had normal acoustic parameters and spectrograph. 47% were improved with reduced parameters and improved spectrograph. The acoustics in 20% cases didn't change at all after treatment. The acoustic parameters were significantly decreased after the treatment of arytenoid motion. CONCLUSION: The present study suggested that the acoustic parameters may estimating the degrees of voice lesion as objective standards and NNE may judge the degree of glottic closure. Both acoustic parameters and spectrograph are of value in the diagnosis, treatment effect and prognosis observation to cricoarytenoid joint trauma.

Adolescent↗
PubMed2001

[Experimental studies on antitumor effect by the new recombinant tumour necrosis factor and cyclophosphamide in nude mice bearing laryngeal carcinoma].

OBJECTIVE: We aimed at finding ideal biological treatment and regime for laryngeal carcinoma. METHOD: Nude mice model bearing laryngeal carcinoma were established using laryngeal carcinoma cell line (HEP-2). New recombinant human tumor necrosis factor (NrhTNF-alpha) and cyclophosphamide were administered locally or systemically, single or in combination. The microstructural and ultra-micro-structural changes of carcinoma after administration of NrhTNF-alpha were observed under light and electron microscopes. RESULT: 1. After treatment, the tumor showed hemorrhage, necrosis, regression, the survival time was prolonged. 2. More significant antitumor effect was observed when locally administered NrhTNF-alpha than intravenously administered of NrhTNF-alpha. 3. There is a notable synergistic antitumor effect by the combination use of NrhTNF-alpha and cyclophosphamide. 4. Microscopy showed that cell changes mostly took place in plasma especially in mitochondria and endoplasmic neticula. The mitochondria were highly bloated. Besides, some nuclei were condensed and fragmented resulted in cell death. CONCLUSION: These studies provide experimental basis for biological treatment of laryngeal carcinoma.

Administration, Topical↗
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

[Study on the coagulation state of laryngeal cancer patients before and after operation].

OBJECTIVE: To explore the coagulation state of laryngeal cancer patients before and after operation. METHOD: The eight parameters of coagulant system of 46 laryngeal cancer patients were examined before operation, 1 day and 10 days after operation, and compared with control group. RESULT: The result suggests, anticoagulant activity decreased and fibrinolytic activity increased in laryngeal cancer patients before operation. Laryngectomy trauma may worsen the abnormality. With the incision of tumors and recovery from operation trauma, anticoagulant activity and fibrinolytic activity of the patients gradually returned to normal level. CONCLUSION: Coagulation disorders in laryngeal cancer patients had existed in a way. With operation trauma, it may worsen the abnormality. So anticoagulant and fibrinolytic systems of these patients should be taken seriously to prevent thrombosis and bleeding.

Adult↗
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

[Therapeutic angiogenesis with the use of vascular endothelial growth factor 165 gene in the myocardium of miniature swine].

The purpose of the present study was to examine whether adenovirus-mediated vascular endothelial growth factor l65 (VEGFl65) can enhance collateral vessel formation of coronary artery and improve regional myocardial perfusion and function. Using a miniature swine model of chronic myocardial ischemia, the replication-deficient recombinant adenovirus vector containing complementary deoxyribonucleic acid (cDNA) for human VEGFl65 (Ad-VEGFl65) or for beta-galactosidase (Ad-Gal) was administered directly into the ischemic myocardium in the left circumflex (LCX) distribution. Myocardial perfusion and function were assessed by electrocardiogram-gated single photon emission computed tomography (SPECT) imaging and collateral vessel development of coronary artery was assessed by ex vivo coronary angiography (CAG). Four weeks after Ad-VEGF165 administration, SPECT imaging demonstrated a significant reduction in ischemic area (P<0.01) and ischemic severity (P<0.01), and a substantial improvement in left ventricular ejection fraction (P<0.01) and regional wall motion in the LCX distribution (P<0.05), as compared with that of control animals and that before administration of Ad-VEGFl65. Collateral vessel development with Rentrop Grading was also significantly greater in Ad-VEGF165 animals than in the Ad-Gal control animals (P<0.05). It's concluded that Ad-VEGFl65 can induce collateral vessel development in ischemic myocardium and result in significant improvement in myocardial perfusion and function.

Adenoviridae↗
PubMed2001

[Expression and significance of serum soluble tumor necrosis factor receptor-I in patients with head and neck neoplasm].

OBJECTIVE: To investigate the expression and significance of serum soluble tumor necrosis factor receptor-I (sTNFR-I) in patients with head and neck neoplasms. METHOD: The study was undertaken to detect serum sTNFR-I levels in 160 head neck cancer patients (including 12 cases of malignant lymphoma, 62 nasopharyngeal cancer, 56 laryngeal cancer, 22 hypopharyngeal cancer, 3 maxillary cancer and 5 thyrophyma), using Sandwich enzyme-linked immuno-sorbent assay. RESULTS: The sTNFR-I levels were significantly higher in patients with carcinoma than those of healthy controls (P < 0.01). The sTNFR-I levels of malignant lymphoma and nasopharyngeal carcinoma were the highest among patients with head and neck neoplasm. The correlations between the serum sTNFR-I levels and the stages of head and neck neoplasms and other laboratory parameters were also analyzed and discussed. CONCLUSION: The serum sTNFR-I levels may reflect the human immunity function, therefore it can be used as a helpful indicator to evaluate the therapeutic effect and monitor the relapses and metastasis of cancer.

Adolescent↗
PubMed2000

Enhanced allergic sensitization by residual oil fly ash particles is mediated by soluble metal constituents.

Epidemiological studies have demonstrated an association between elevated levels of particulate matter (PM) air pollutants and exacerbation of asthma symptoms. We have shown in a Brown Norway (BN) rat model of house dust mite (HDM) allergy that preexposure to residual oil fly ash (ROFA) particles enhanced the sensitization phase such that the secondary immune response and associated lung injury were increased after allergen challenge. To determine whether the metals present in ROFA mediated this effect, BN rats were intratracheally instilled with either ROFA (1000 microg) or acidified saline + NiSO(4) (105.12 microg), VSO(4) (98.2 microg), FeSO(4) (58.49 microg), or a mixture (Mix) of each metal. HDM-specific IgE was higher in the serum of the ROFA, Ni, V, and Mix groups than in the HDM group after challenge, and antigen-induced bronchoconstriction responses were increased in the Ni group. Lymphocyte proliferation to antigen was increased in the ROFA, Ni, and V groups compared to controls. Total protein and eosinophil peroxidase levels were elevated in the Fe group, and eosinophil numbers in the bronchoalveolar lavage fluid (BALF) were increased in the ROFA and Fe groups compared to HDM control. IL-5 and IL-13 mRNA expression was also increased in the lung tissue of all metal and ROFA-treated groups, while BALF IL-10 was elevated in the Fe and Mix groups, and IL-6 and TNF-alpha were elevated in the metal and ROFA-treated groups compared to controls. These results suggest that ROFA's metallic constituents mediate enhancement of sensitization to HDM and that pulmonary inflammation may play a role in this adjuvant effect.

Animals↗
PubMed2000

The relationship between activated protein C-resistance and recurrent abortion.

The activated protein C-resistance (APC-R) method based on APTT was used in 40 non-pregnant multiparas (control group) and 55 patients with abortion of unknown origin (experimental group) in order to explore the relationship between APC-R and recurrent abortion. A significant difference in APC-R-positive rate was found (P < 0.01) between control group and experimental group, with the rate being 5% in the controls and 25.5% in the experimental group. And the APC-R-positive rates in the patients with only twice abortions and the patients over-3-time abortions were 22.6% and 29.2%, respectively (P > 0.05). The APC-R-positive rate, which was 37.9% in the patients of late abortion, was much higher than that in the patients of early abortion. It is concluded that APC-R has something to do with recurrent abortion, and is closely related to late abortion, but bears no obvious relationship with times of abortions.

Abortion, Habitual↗
PubMed2000

Green fluorescence protein as a transcriptional reporter for the long terminal repeats of the human immunodeficiency virus type 1.

Using the enhanced green fluorescence protein (EGFP), a transient reporter expression system was established to assess the transcriptional activity of the long terminal repeats (LTR) of primary isolates of the human immunodeficiency virus type 1 (HIV-1). Consistent with the conventional chloramphenicol acetyl transferase (CAT) reporter, EGFP expression, under the direction of HIV-1 LTR, was readily detected in the transient transfection and was elevated by co-transfection of HIV-1 tat-expression vector. Comparing to CAT, however, EGFP expression system has two advantages: (i) Using a fluorescence activated cell sorter (FACS), it was possible to simultaneously measure transfection efficiency and fluorescence intensity of the transfected live cells without the necessity of co-transfection of a reference plasmid for comparing the transcriptional activity of two promoters; and (ii) EGFP expression was readily detected at a DNA concentration where CAT activity was not detectable possibly because the transfectants could be 'gated'. On the other hand, at a higher concentration of DNA, CAT signal became more prominent than that of EGFP, possibly because the enzymatic activity of CAT 'amplified' the signal. EGFP fluorescence detected by FACS was a direct measurement of the expressed chromophore. It is concluded that the system is rapid, reproducible, convenient and useful for quantitative analysis of transcription.

Chloramphenicol O-Acetyltransferase↗
PubMed2000

Sorption and desorption of Eu and Yb on alumina: mechanisms and effect of fulvic acid.

The effects of pH, ionic strength and FA (fulvic acid) on the sorption and desorption of Eu(III) and Yb(III) on alumina were respectively investigated by using batch technique and radiotracers 152 + 154Eu and 169Yb. The distribution coefficients for sorption and desorption of Eu on alumina at pH 4.4, 4.6 and 5.7 in 1 mol/l NaCl solutions as a function of solid phase concentration were determined in the presence or absence of FA. The effects of pH, FA and ionic strength on the distribution coefficients for sorption and desorption of Yb on alumina were determined in 0.01-2.0 mol/l NaNO3. It was found that pH and FA influenced the sorption of Eu(III) and Yb(III) on alumina greatly. A surface hydrolysis model can satisfactorily and qualitatively explain the observations on bare alumina. The competition among the complexations of surface free hydroxyl groups, soluble and sorbed fulvic acids can satisfactorily and qualitatively explain the observations on the coated alumina.

Adsorption↗
PubMed2000

Enantiomeric degradation of 2-(4-Sulfophenyl)Butyrate via 4-sulfocatechol in Delftia acidovorans SPB1.

Enrichment cultures with enantiomeric 2-(4-sulfophenyl)butyrate (SPB) as the sole added source(s) of carbon and energy for growth yielded a pure culture of a degradative bacterium, which was identified as Delftia acidovorans SPB1. The organism utilized the enantiomers sequentially. R-SPB was utilized first (specific growth rate [mu] = 0.28 h(-1)), with transient excretion of an unknown intermediate, which was identified as 4-sulfocatechol (4SC). Utilization of S-SPB was slower (mu = 0.016 h(-1)) and was initiated only after the first enantiomer was exhausted. Suspensions of cells grown in S-SPB excreted 4SC, so metabolism of the two enantiomers converged at 4SC. The latter was degraded by ortho cleavage via 3-sulfo-cis,cis-muconate. Strain SPB1 grew with 4SC and with 1-(4-sulfophenyl)octane (referred to herein as model LAS) but not with commercial linear alkylbenzenesulfonate (LAS) surfactant, which is subterminally substituted but nontoxic. It would appear that metabolism of the model LAS does not represent metabolism of commercial LAS.

Benzenesulfonates↗
PubMed2000

An alpha-proteobacterium converts linear alkylbenzenesulfonate surfactants into sulfophenylcarboxylates and linear alkyldiphenyletherdisulfonate surfactants into sulfodiphenylethercarboxylates.

The surfactant linear alkylbenzenesulfonate (LAS; 0.5 mM) or linear monoalkyldiphenyletherdisulfonate (LADPEDS; 0.5 mM) in salts medium was easily degraded in laboratory trickling filters, whereas carbon-limited, aerobic enrichment cultures in suspended culture with the same inocula did not grow. We took portions of the trickling filters which degraded LADPEDS, shook the organisms from the solid support (polyester), and found that growth in suspended culture in LADPEDS-salts medium occurred only in the presence of some solid support (polyester fleece or glass wool), though little biomass was immobilized on the support. The end products in suspended culture were identical with those from the trickling filters. There was low plating efficiency of LADPEDS-grown cultures on complex medium, and no picked colony or mixture of colonies grew in LADPEDS-salts-glass wool medium. However, selective plates containing LADPEDS-salts medium solidified with agarose yielded LADPEDS-dependent, pinpoint colonies which could be picked singly and subcultured in selective liquid medium. Isolate DS-1 was a bacterium which showed 93% sequence homology (16S ribosomal DNA) to its nearest phylogenetic neighbor, an alpha-proteobacterium. Strain DS-1 grew heterotrophically in LADPEDS-salts-glass wool medium and converted the set of aryl-substituted alkanes to the corresponding aryl-substituted carboxylic acids of shorter chain length. Similarly, strain DS-1 grew heterotrophically with commercial LAS, converting it to a set of sulfophenylcarboxylates. Growth with a single isomer of LAS [3-(4-sulfophenyl)dodecane] was concomitant with excretion of 4-(4-sulfophenyl)hexanoate, which was identified by matrix-assisted laser desorption ionization mass spectrometry. The growth yield (6.4 g of protein/mol of C) indicated mass balance, which, with the specific growth rate (0.05 h(-1)), indicated a specific utilization rate of LAS of 2.2 mkat/kg of protein.

Alphaproteobacteria↗