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Biomedical subjects

W Sun

Publications and source records attributed to W Sun.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Wet FGD process on rotating-stream-tray tower with magnesium-enhanced lime].

Wet flue gas desulfurization(FGD) process with magnesium-enhanced lime slurry was conducted on a rotating-stream-tray tower. Changes of SO2 removal efficiency and slurry pH with time were experimentally determined. Effects of magnesium sulfate concentration were investigated and the lime utilization was calculated according to experimental data. In comparison with lime FGD process, adding magnesium sulfate could effectively enhance SO2 removal efficiency; when the adequate magnesium sulfate concentration was 0.2 mol/L, the removal efficiency was more than 60% with two rotating-stream-trays, while the removal efficiency of lime process was only 45%. To achieve higher SO2 removal efficiency, the slurry pH should be controlled between 6.0 and 7.5. Magnesium sulfate could also promote lime dissolution, slow down descent of slurry pH and increase lime utilization; when magnesium sulfate concentration was 0.2 mol/L, lime utilization could be increased by more than 5 percentage point under adequate conditions.

Calcium Compounds↗
PubMed2001

[Effect of pH on copper sorption by the loess and its species].

To study the effect of pH on copper sorption and species, loess was taken as sorbent in this research, and control experiments were conducted with quartz. All the curves of sorption amount-pH showed three regions, namely, sorption amount increased slowly at low pH, then increased quickly with the rise of pH, and reached the maximum amount at high pH. Copper of sorbed, exchangeable and bound to carbonate decreased with the increase in sediment concentration at constant Cu concentration, and increased with the increase in Cu concentration at constant sediment concentration. The MINTEQA2 model results showed that the proportions of precipitates and their compositions were different for loess and quartz, and the proportions of precipitates decreased with the concentrations of loess.

Adsorption↗
PubMed2001

Adjuvant chemotherapy for muscle-invasive bladder cancer.

The curability of bladder cancer is directly related to the pathologic stage of the primary tumor. If extravesical extension or lymph-node metastases are present, the risk of metastatic progression is significant. Adjuvant chemotherapy has been proposed for these patients in an attempt to reduce the probability of relapse and to improve survival. Although improved survival with cisplatin-based adjuvant chemotherapy is suggested in some studies, the actual benefit of the treatment after radical cystectomy for patients with muscle-invasive bladder cancer is still controversial due to the absence of sufficiently powered prospective randomized clinical trials. Ongoing and future trials should further define the role of adjuvant chemotherapy in bladder cancer treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

[Combined gene therapy for murine liver cancer with interleukin-18 and cytosine deaminase genes].

OBJECTIVE: To investigate the synergistic antitumor effects of murine IL-18 and CD/5FC gene therapy on mice bearing liver cancer. METHODS: A retrovirus vector pGCEN/IL-18 containing murine interleukin-18 gene was constructed. The retrovirus carrying IL-18 gene was used to infect murine liver cancer cell MM45T.Li, and proved to secret biological active IL-18. In mice bearing liver cancer, (60)Co-irradiated MM45T.Li/IL-18 vaccine was inoculated subcutaneously once a week for two weeks, and/or AdCD was injected intratumorally with 5FC injected i.p. for 8 days. RESULTS: Thirty days from the treatment, the tumor volume of control group was 1580 approximately 1625 mm(3), MM45T.Li/IL-18 vaccine group was 366 +/- 159 mm(3), AdCD/5FC group was 438 +/- 65 mm(3), and combined IL-18 and AdCD/ 5FC therapy group was 15 +/- 7 mm(3) (P<0.05). The tumor volume in single gene therapy group reduced to the smallest after three-week treatment, but grew large again, while the tumor volume in combined therapy group still remained small. The median survival time in control group was 50.0 approximately 51.5 days, MM45T.Li/IL-18 group was 65 days, AdCD/5FC group was 57 days versus 75 days for combined gene therapy group (P<0.05), and with more abundant infiltration of CD4+ and CD8+ lymphocytes around the tumor in combined gene therapy group. CONCLUSIONS: Combined gene therapy with IL-18 and CD/5FC can reduce the tumor volume and elicit the antitumor immunity of the host, which is superior to the single gene therapy for murine liver cancer.

Animals↗
PubMed2001

[Study on anti-HBV effects by antisense oligodeoxynucleotides in vitro].

OBJECTIVE: To study the inhibition effect of anti-HIV oligodeoxy-nucleotides on HBV X gene. METHODS: Three antisense phosphorothioate oligodeoxy-nucleotides(AsON) complementary to the initiator of X, DR2, EN II respectively, were synthesized and tested for their anti-HBV activity on HepG2.2.15 cells with ELISA methods. RESULTS: When the best effect concentration of AsON was 10 mumol/L, the inhibition rates on HBsAg of three AsON were 57%, 60% and 52% respectively, and on HBeAg were 56%, 45% and 56% respectively. There were two inhibition peaks at different times. There was no inhibition effect treated by random control (< 12%). Using the 3-(4,5-dimethythiazol-xyl)-2,5-diphnyl tetrazolium bromide method, there was no cytotoxicity at 40 mumol/L of AsON. CONCLUSION: AsONs on three key region of X gene were effective drugs to inhibit the expression of HBV.

Antiviral Agents↗
PubMed2001

[Change of prolactin in SD rats with experimental autoimmune thyroiditis].

OBJECTIVE: To verify the effect of prolactin (PRL) on the development and progression of experimental autoimmune thyroiditis (EAT) in SD rats and the inhibitive effect of bromocriptine (BRC) on the development of EAT. METHODS: SD rats were injected with BRC to inhibit the development of EAT and the change of PRL were observed. RESULTS: High level of serum PRL was found in the EAT rats [(8.70 +/- 0.42) microg/L, P < 0.01 vs. control (6.46 +/- 0.67) microg/L], and there was also high levels of thyroid autoantibodies (thyroglobulin antibody, thyroid peroxidase antibody). However, in rats receiving BRC, the levels of thyroid autoantibodies decreased as the PRL level declined (5.30 +/- 0.81) microg/L and the thyroid lesions were mild. CONCLUSION: Hyperprolactinemia plays a role in the development of EAT and control of the hyperprolactinemia with BRC may afford therapeutic benefit.

Animals↗
PubMed2001

[Adipocytes differentiation of NIH3T3 cells induced by peroxisome proliferator activation receptor gamma 2 expression].

OBJECTIVE: To express the mouse peroxisome proliferator activated receptor gamma 2(mPPAR gamma 2) in NIH3T3 cells mediated by the recombinant retrovirus and study its function. METHODS: mPPAR gamma 2 gene digested from the recombinant plasmid pcDNA3/mPPAR gamma 2 and confirmed to contain the target gene segment with fluorescence-sequencing was subcloned into retrovirus vector pGCEN to generate the recombinant retrovirus pGCEN/mPPAR gamma 2. The recombinant retrovirus pGCEN/mPPAR gamma 2 and pGCEN were packaged with PA317 cells and anti-G418 clones of PA317 cells were selected. Viral supernatants were collected and used to infect NIH3T3 cells. Peroxisome proliferator activated receptor gamma 2 (PPAR gamma 2)-expressing NIH3T3 cells cultured in the differentiation media containing PPAR gamma activator ETYA were induced into adipocytes. RESULTS: The recombinant retrovirus pGCEN/mPPAR gamma 2 was constructed, 5 x 10(4) CFU/ml of the viral supernatants containing pGCEN/mPPAR gamma 2 and 6 x 10(5) CFU/ml of the viral supernatants containing pGCEN were obtained. mPPAR gamma 2 was expressed in NIH3T3 cells mediated by the recombinant retrovirus. Lipid accumulation obviously existed in PPAR gamma 2-expressing NIH3T3 cells at 10 days postdifferentiation and the lipid-containing cells morphologically resembled the mature adipocytes in vivo. CONCLUSION: An adipocyte differentiation model in vitro was established. The work is the basis for further researches on the molecular mechanism of adipocyte differentiation induced by PPAR gamma 2.

3T3 Cells↗
PubMed2001

[A clinical analysis of 798 cases of M protein positive patients].

OBJECTIVE: To improve the understanding of the diseases with positive M protein by analyzing 798 cases, so as to reduce the failure and error of diagnosis. METHODS: The relations of diseases with the types of the disease and age and sex of the patients were analyzed. The presenting symptoms of multiple myeloma(MM) and non-MM were compared. The difference of Ig content among each type of MM and the characteristics of M protein in non-MM were also studied. RESULTS: In 798 cases with positive M protein, there were 648 cases of MM (81.2%) and 34 cases of Waldenstrom's macroglobulinemia (WM) (4.3%). The remaining 116 cases (14.5%) were benign or secondary monoclonal gammopathies. The average age of the patients was 58.3 years, and there was no difference of disease incidence between men and women. There was a marked difference between MM and non-MM in the presenting symptoms which were mainly lumbago and bone pain in MM but fever, weight loss and fatigue in non-MM. 648 cases of MM included 290 cases of IgG type (44.8%), 143 of IgA type (22.1%), 138 of light chain type (21.3%), 45 of IgD type (6.9%), 30 of non-secretion type (4.6%) and 2 of double-clonal type (0.3%). There was no marked distinction between kappa and lambda chain except in IgD type. The average M protein content of 116 cases of benign or secondary monoclonal gammopathies was (11.3 +/- 6.5) g/L. 55 of the 116 cases were monoclonal gammopathy of undetermined significance (MGUS), which accounted for 6.9% of all the cases. 35 cases were non-Hodgkin's lymphoma (NHL) (4.4%). CONCLUSION: M protein was mainly discovered in MM; it may also be discovered in MGUS, NHL, WM and other diseases. It is essential to have a better understanding of these diseases.

Adult↗
PubMed2001

[The effects of nifedipine on proliferation and DNA synthesis of gingival fibroblasts].

OBJECTIVE: To investigate the effects of nifedipine, a calcium channel blocker, on cellular proliferation in gingival fibroblasts in vitro. METHODS: Gingival fibroblasts were cultured and incubated with various concentrations of nifedipine (1,200.0, 360.0, 108.0 and 32.4 micrograms/L) for up to 7 days. H-TdR incorporation assay in vitro taken was used to evaluate the amount of DNA synthesis. RESULTS: Cell numbers were significantly different among these groups on sixth and seventh day, especially higher in 1,200.0 micrograms/L and 360.0 micrograms/L groups. The incorporation percentage in high concentration groups were significantly higher than those in others. CONCLUSION: Nifedipine can influent proliferation of gingival fibroblasts in high concentration.

Adolescent↗
PubMed2001

Ocular histopathological changes after eyeball enucleation induced by corneal trauma.

OBJECTIVE: To observe the ocular histopathological changes after eyeball enucleation induced by corneal trauma. METHODS: Light microscopic examination was done on 117 eyeball specimens enucleated after corneal trauma (18 with corneal fissure and 99 with corneal perforating trauma). RESULTS: Acute, subacute or chronic inflammatory changes, and fibrous membrane formation were observed in well-closed corneal wounds, whereas inflammation, atrophy and scar were observed in the focal tissues. But at the late period, secondary glaucoma, retinal detachment, endophthalmitis and eyeball atrophy resulted in blindness. Corneal fistula was observed in those with inadequate cure of wounds caused by ingrowth of corneal epithelium, embedment of iris and vitreous body, and large area of centrally located tissue deficiency of the corneal. A high incidence of endophthalmitis was noted due to the presence of corneal fistula. Severe inflammation was observed in the anterior segmental tissues with fibrous infiltration in the anterior chamber, which might result in rapid destruction of the eyeballs. CONCLUSIONS: Ocular pathology varies with the difference of the position, form, size and closing conditions of the corneal laceration after trauma.

Adolescent↗
PubMed2001

[A pathological study of lens subcapsular epithelial proliferation].

OBJECTIVE: To observe the histopathological changes of lens subcapsular epithelial proliferation and analyze their etiology. METHODS: Sixty-four enucleated eyes with lens subcapsular epithelial proliferation were observed with light microscopy and analyzed retrospectively. Among all the cases of lens subcapsular epithelial proliferation, there were 36 ones enucleated because of trauma, 10 absolute glaucoma, 6 corneoscleral staphyloma, 5 intraocular tumor, 2 after cataract extraction, 4 endophthalmitis, 1 cataract combined with ocular atrophy (diabetes type II). RESULTS: Proliferated lens subcapsular epithelial cells were atypical, irregularly arranged, and extended to the posterior subcapsule. In cases with lens capsular rupture or partial absence, there were subcapsular fibro-connective tissue metaplasia, scar tissue formation, cortical collapse, local liquefaction and calcification. CONCLUSION: Lens subcapsular epithelial proliferation is caused by some intraocular pathological conditions. In cases with endophthalmitis and ocular trauma, its severity is the most serious.

Adolescent↗
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

[Nasal cavity dimensions in the infants measured with acoustic rhinometry].

OBJECTIVE: To investigate the range of normal value of minimal cross-sectional area (MCA) of the nasal cavity, distance of minimal cross-sectional area from the nostril (DCA), total nasal cavity volume(NV) and total nasopharyngeal cavity volume (NPV) of healthy infants. METHOD: One hundred and seventy-five healthy infants and one hundred and eight infants suffered from acute upper respiratory tract infection were measured with acoustic rhinometry. RESULT: The range of total MCA of healthy infants was 0.2-0.5 (cm)2, DCA was 1.93-2.47 cm, NV was 2.69-4.75 cm3 and NPV was 3.83-8.92 cm3. Comparing healthy infants with infants suffered from acute upper respiratory tract infection, there all were significant differences in MCA, DCA and NV. CONCLUSION: Acoustic rhinometry suit objective assessment of the nasal airways in infants. It is demonstrated that these data can provide available information for the study of nasal physiology and pathophysiology, well as for the diagnosis and judgement of therapeutic effectiveness of nasal diseases.

Child, Preschool↗
PubMed2000

Structure, sequence, and promoter analysis of human disabled-2 gene (DAB2).

Disabled-2 (DAB2 for human and Dab2 for other species) is one of two mammalian orthologues of Drosophila Disabled. DAB2 exhibits properties of a tumor suppressor gene: the expression of DAB2 is eliminated in 85-95% of breast and ovarian tumors; homozygous deletions of the gene have been found in some of these tumors; and reintroduction of DAB2 expression suppresses tumorigenicity of carcinoma cells. To study the mechanisms of loss of expression and to detect possible mutations in tumors, we have investigated the genomic structure of the DAB2 gene. The complete DAB2 gene was identified and sequenced from four overlapping BAC clones found to contain the gene. Complement factor 9 (C9) gene was localized next to the DAB2 gene at the 3'-end of the BAC DNA fragments. The human DAB2 gene is about 35 kb in size and consists of 15 exons and 14 introns, producing an approximately 4-kb message. A spliced variant corresponding to mouse Dab2 p93 and a 3'-end spliced variant were also identified. The translation initiation site resides in the second exon, and the noncoding first exon is separated from the second exon by a 14-kb intron. The 420-bp sequence 5' of exon 1 contains a CpG island (39 CpG sites). This 420-bp putative promoter was found to contain the site for transcription initiation, identified by RNase protection assay, and is sufficient for active transcription in epithelial cells. The information about the gene structure of DAB2 will enable us to analyze possible mutations and the mechanisms of loss of DAB2 expression in tumors.

Adaptor Proteins, Signal Transducing↗
PubMed2000

MEKK2 associates with the adapter protein Lad/RIBP and regulates the MEK5-BMK1/ERK5 pathway.

MEKK2 and MEKK3 are two closely related mitogen-activated protein kinase (MAPK) kinase kinases. The kinase domains of MEKK2 and MEKK3 are nearly identical, although their N-terminal regulatory domains are significantly divergent. By yeast two-hybrid library screening, we have identified MEK5, the MAPK kinase in the big mitogen-activated protein kinase 1 (BMK1)/ERK5 pathway, as a binding partner for MEKK2. MEKK2 expression stimulates BMK1/ERK5 activity, the downstream substrate for MEK5. Compared with MEKK3, MEKK2 activated BMK1/ERK5 to a greater extent, which might correlate with a higher affinity MEKK2-MEK5 interaction. A dominant negative form of MEK5 blocked the activation of BMK1/ERK5 by MEKK2, whereas activation of c-Jun N-terminal kinase (JNK) was unaffected, showing that MEK5 is a specific downstream effector of MEKK2 in the BMK1/ERK5 pathway. Activation of BMK1/ERK5 by epidermal growth factor and H2O2 in Cos7 and HEK293 cells was completely blocked by a kinase-inactive MEKK3 (MEKK3kin(-)), whereas MEKK2kin(-) had no effect. However, in D10 T cells, expression of MEKK2kin(-) but not MEKK3kin(-) inhibited BMK1/ERK5 activity. Two-hybrid screening also identified Lck-associated adapter/Rlk- and Itk-binding protein (Lad/RIBP), a T cell adapter protein, as a binding partner for MEKK2. MEKK2 and Lad/RIBP colocalize at the T cell contact site with antigen-loaded presenting cells, demonstrating cotranslocation of MEKK2 and Lad/RIBP during T cell activation. MEKK3 neither binds Lad/RIBP nor is recruited to the T cell contact with antigen presenting cell. MEKK2 and MEKK3 are differentially associated with signaling from specific upstream receptor systems, whereas both activate the MEK5-BMK1/ERK5 pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2000

MEKK2 gene disruption causes loss of cytokine production in response to IgE and c-Kit ligand stimulation of ES cell-derived mast cells.

Ligation of the high-affinity IgE receptor (FcepsilonRI) or of c-Kit stimulates cytokine production in mast cells. We show that MEK kinase 2 (MEKK2), a MAPK kinase kinase (MAP3K) that regulates the JNK and ERK5 pathways, is required for cytokine production in embryonic stem (ES) cell-derived mast cells (ESMC). Targeted disruption of the MEKK2 or MEKK1 gene was used to abolish expression of the respective kinases in ESMC. Transcription of specific cytokines in response to IgE or c-Kit ligand was markedly reduced in MEKK2(-/-) ESMC relative to wild-type ESMC. Cytokine production in MEKK1(-/-) ESMC was similar to that of wild-type ESMC, demonstrating the specificity of MEKK2 in signaling cytokine gene regulation. MEKK2(-/-) ESMC also lost receptor-mediated stimulation of JNK. In contrast, JNK activation in response to UV irradiation was normal, showing that MEKK2 is required for receptor signaling but not for cellular stress responses. MEKK2 is the first MAP3K shown to be required for mast cell tyrosine kinase receptor signaling controlling cytokine gene expression.

Animals↗