Biomedical subjects

Z Chen

Publications and source records attributed to Z Chen.

At least 685 records · Page 38Linked to original sources

PubMed1999

[The effects of lipopolysaccharide and anti-inflammatory drugs on nuclear factor-kappa B in pulmonary intravascular macrophage].

OBJECTIVE: To investigate activation of nuclear factor-kappa B(NF-kappa B) in pulmonary intravascular macrophage (PIM) stimulated with lipopolysaccharide (LPS) and effects of anti-inflammatory drugs dexamethasone (DEX) and aspirin (ASA) on the process. METHODS: PIMs isolated from three healthy pigs were cultured and divided into four groups: Control group; LPS- stimulated group; DEX- or ASA-treated group. The NF-kappa B activity of nuclear protein extract from the PIMs and the concentration of tumor necrosis factor alpha (TNF-alpha) in the supernatant were measured by electrophoretic mobility shift assay (EMSA) and radioimmunoassay (RIA), respectively. RESULTS: The activity of NF-kappa B significantly increased from 0.5 hr to 4 hr after LPS stimulation (P < 0.01); The level of TNF-alpha in the supernatant elevated markedly from 1 hr to 2 hr after LPS stimulation (P < 0.01); positive correlation was found between the NF-kappa B activity and the TNF-alpha concentration at 1 hr after LPS stimulation (r = 0.991, P < 0.01). Compared with LPS-stimulated group, both NF-kappa B activity and TNF-alpha concentration were significantly lowered in DEX- or ASA-treated groups (P < 0.01). CONCLUSIONS: LPS might activate NF-kappa B in the PIMs, and induce the increase of transcription and expression of TNF-alpha gene; Both DEX and ASA could inhibit the activation of NF-kappa B and reduce the release of TNF-alpha.

Animals↗

PubMed1999

[A preliminary study on the markers of pulmonary vascular endothelial cells in patients with ARDS].

OBJECTIVE: To explore the changes of the markers of pulmonary vascular endothelial cell (PVEC) in patients with ARDS. METHODS: The levels of plasma circulating endothelial cell(CEC), granule membrane protein-140(GMP-140), endothelin-1(ET-1) and von Willebrand factor (vWF) were determined respectively in 13cases of ARDS. The vWF on the surface of the PVEC were stained in 5 cases of ARDS. RESULTS: Circulating CEC, GMP-140, ET-1 and vWF levels were increased significantly (P < 0.01) but scores of vWF expression on the PVEC became weak (P < 0.01) in ARDS samples. The level of plasma GMP-140 elevated dramatically in 2nd day( > 4 times). CONCLUSIONS: PVEC are severely impaired during ARDS. GMP-140 released from PVEC might be a satisfactory criteria for early surveillance and for evaluation of prognosis of ARDS in clinical practice.

Adult↗

PubMed1999

[Infiltration of monocytes/macrophages and expression of monocyte chemoattractant protein-1 in gingival tissues from patients with rapidly progressive periodontitis].

OBJECTIVE: To find if there was any difference in monocytes/macrophages infiltration and monocyte chemoattractant protein-1(MCP-1) expression between rapidly progressive periodontitis (RPP) and adult periodontitis (AP) tissues. METHODS: Inflamed gingival specimens (20) were obtained from RPP(14) and AP(6) patients, and specimens from clinically healthy subjects (H,6) as control. The monocytes/macrophages and MCP-1 expression were detected by immuno-histochemistry SP assay with antibodies against CD14 and CD68, and rabbit anti-MCP-1 antibody. RESULTS: There were no differences in the mean counts (+/- SD) of monocytes/macrophages and MCP-1 positive cells between RPP and AP groups. CONCLUSION: Though rapid and severe periodontal destruction occurs in RPP, there is no differences in monocytes/macrophages infiltration and MCP-1 expression in gingival tissues between rapidly progressive periodontitis and adult periodontitis patients.

Adult↗

PubMed1999

[Apoptosis in the developing tooth of postnatal rat].

OBJECTIVE: To study apoptosis in the developing tooth of postnatal rat. METHODS: Transferase-mediated, dUTP-biotin nick end labeling(TUNEL) method was utilized to label the paraffin sections of the lower and upper jaws taken from 3 days and 9 days of postnatal rats. RESULTS: Positive stains for the presence of apoptosis were observed in ameloblasts, especially in cervical loop region, and stellate reticulum cells. Odontoblasts at the tip of developing molars in which physiological osteodentin was forming were strongly positive. A few dental pulp cells were labeled. CONCLUSION: Apotosis is a biological process, which play an important role in the formation of teeth. Apoptosis may take place in epithelial derived cells as well as mesenchymal-derived cells.

Animals↗

PubMed1999

[Study on early application of Chinese medicinal herbs after total gastrectomy].

OBJECTIVE: To evaluate the effect of Chinese medicinal herbs on digestive function, nutritional status, immune function and complication rate in patients after total gastrectomy. METHODS: Thirty-nine patients of gastrectomy were divided into two groups and were intubated into small intestine for administering postoperatively. Twenty-one of them belonged to the treated group and were dripped with Chinese medicinal herbs intraluminally during the early postoperative stage, while 18 cases of the control group were dripped with 0.9% sodium chloride. RESULTS: The digestive function of the treated group recovered rapidly, and the nutritional status and immune function improved markedly as compared with those of the control group (P < 0.001-0.05). CONCLUSION: Early application of Chinese medicinal herbs after total gastrectomy could promote the digestive function to recover to normal, the nutritional status and immune function to improve. The occurrence of complication was reduced.

Administration, Rectal↗

PubMed1999

[Clinical comparative observation on duodongning and Ritalin in treating child hyperkinetic syndrome].

OBJECTIVE: To study the effect and side-effect of Duodongining (DDN), a Chinese herbal preparation, in treating child hyperkinetic syndrome. METHODS: Double blind method was used in observation on effect of DDN and compared with that of Ritalin. RESULTS: In the 37 patients treated with DDN, 17 (45.9%) were markedly effective and 16 (43.2%) were effective. In the 33 Patients treated with Ritalin, the respective case numbers were 15 (45.5%) and 14 (42.4%). The Conners Hyperactive Index of the DDN group before treatment was 2.01 +/- 0.83, and after treatment 1.17 +/- 0.76, while that of the Ritalin group was 2.07 +/- 0.91 before treatment and 1.47 +/- 0.79 respectively after treatment. There were no significant difference between the two groups both in effect and in Conner Index, P > 0.05. The main side-effect was lack of appetite, it revealed in 3 cases of the DDN group and 7 cases of the Ritalin group, and was severer in the latter. CONCLUSION: The effect of DDN and Ritalin were not different significantly, but the side-effect of Ritalin was severer than that of DDN.

Attention Deficit Disorder with Hyperactivity↗

PubMed1999

[Reversal of multidrug resistance of leukemia cell line in vitro by antisense phosphorothioate oligonucleotide].

OBJECTIVE: To investigate the effectiveness of 14 mer antisense phosphorothioate oligonucleotide (AS-SODN) complementary to the published multidrug resistance gene (mdr(1) gene) sequence to reverse multidrug resistance of leukemia cell line. METHODS: 50% inhibitory concentration (IC(50)) of K562 cell line resistant to adriamycin (K562/ADM cell line) was determined by the tetrazolium dye, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, the concentration of daunorubicin (DNR) in the cell by flow cytometry, the level of P170 by immunohistochemical staining technique and the level of mdr(1)-mRNA by half-quantitative RT-PCR (the ratio of mdr(1)/beta(2)-MG). RESULTS: Treatment of K562/ADM cell line with 2 micromol/L AS-SODN reduced the level of both the mdr(1)-mRNA and P170. The ratio of mdr(1)/beta(2)-MG reduced from (2.07 +/- 0.16) to (1.57 +/- 0.14), and positive rate of P170 expression decreased from (98.26 +/- 1.35)% to (18.30 +/- 6.50)%. Accordingly, the concentration of DNR in cell increased. With these findings, IC(50) to ADM reduced from 25.72 mg/L to 6.97 mg/L and relative efficiency of modulation was 73.01%. CONCLUSION: Antisense oligonucleotide targeting mdr(1) gene can reduce md(1)-mRNA, block P170 expression so as to increase the sensitivity of K562/ADM cell line to chemotherapy drugs.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed1999

[Experimental study of immunization of mice with hepatitis C virus genetic vaccine constructs].

OBJECTIVE: To inquire into the immune responses to expression protein in mice immunized with genetic vaccine of hepatitis C virus (HCV) and lay a foundation for HCV genetic vaccine development in future. METHODS: The gene fragments coding C and most E regions of HCV-II type were inserted into pCD-SRalpha(1) of eukaryotic expression vector and formed genetic vaccine constructs of pCD-HCV(1) and then was injected into the quadriceps muscles of Balb/c mice. The serum anti-HCV level of mice was tested by ELISA and peripheral blood mononuclear cell (PBMC) proliferative responses to HCV antigens were detected by (3)H-TdR incorporation method (cpm). RESULTS: The serum antibody level reached to 0.71 +/- 0.08 - 0.77 +/- 0.06 (A value, the same below) after genetic vaccine pCD-HCV(1) (100 microg/mouse) were inoculated into the mice (n = 12) three or four times while blank vector pCD-SRalpha(1) could not induce the mice (n = 8) to generate antibody response in same way. After the antibody levels in mice (n = 8) immunized by pCD-HCV(1) had ascended to peak value (0.71), there was no trend of descending during the following 18 weeks of detection (0.68 +/- 0.06 - 0.75 +/- 0.07). Specific fragment of HCV cDNA identified by polymerase chain reaction (PCR) from DNA extracted from the muscles of the mice after pCD-HCV(1) had been inoculated three months. PBMC proliferative responses to HCV synthetic peptides CP(9) and gene recombinant antigens C, E(1) in the mice immunized with pCD-HCV(1) were detected and its stimulation indexes (SI) were 4.07 +/- 1.58, 3.88 +/- 0.70 and 3.69 +/- 1.13 respectively and there was a significant difference (P < 0.001) as compared with that of PBMC in mice immunized with pCD-SRalpha(1). CONCLUSION: These investigations demonstrated that genetic vaccine constructs made of HCV structural region can induce Balb/c mice to generate antibody and PBMC proliferative responses to HCV antigens via DNA immunization.

Animals↗

PubMed1999

[Expression and significance of MXR7 mRNA in human hepatocellular carcinoma].

OBJECTIVE: To find out the expression and significance of MXR7 mRNA in human hepatocellular carcinoma. METHODS: The (32)P labeled and purified PCR product of MXR7 cDNA was taken as probe. MXR7 mRNA expression was detected by Northern blot analysis in 30 samples of preoperatively untreated HCC and corresponding surrounding non-cancerous hepatic tissue, and 12 normal liver tissues confirmed pathologically. RESULTS: The frequency of MXR7 mRNA expression in HCC, the corresponding surrounding noncancerous hepatic, and normal liver tissues was 76.6%, 13.3% and 0, respectively. The frequency of MXR7 mRNA expression in HCC without serum AFP elevation and in HCC < 5 cm was 9/10 and 5/6 respectively. CONCLUSIONS: MXR7 mRNA over-expression in human HCC is common and MXR7 mRNA may be expressed at early stage of HCC and can serve as tumor biomarker for HCC. The detection of MXR7 mRNA expression in liver puncture tissues may find small HCC without serum AFP elevation in the subclinical stage.

Adult↗

PubMed1999

[Effect of dietary arginine supplementation on wound healing and the relationship between dose and response in burn rats].

OBJECTIVE: To examine the dose-effect of dietary L-arginine supplementation on burn wound healing. METHODS: The effect of dietary L-arginine supplementation was studied in rats with deep thickness burn (10% TBSA). The time for epithelization of burn wound was determined. Photography of burn wound was taken for measuring percentage of burn wound healing area. Biopsies of burn wound were taken for measuring the content of hydroxyproline, the ratio between type I and type III collagen, and dermal cell cycle. RESULTS: Supplemental dietary L-arginine after burn in rats shortened the time for epithelization of burn wound, increased the content of hydroxyproline, decreased the ratio between type I and type III collagen, elevated the DNA content of dermis. Supplemental dietary L-arginine in the dose of 200 mg x kg(-1) x d(-1) was more effective than any other, 50 mg x kg(-1) x d(-1) and 800 mg kg(-1) x d(-1) showed no beneficial effect on the healing of burn wound. CONCLUSIONS: Suitable L-arginine supplementation can enhance burn wound healing in rats.

Animals↗

PubMed1999

[Long term effect of thymectomy for patients with myasthenia gravis].

OBJECTIVE: To evaluate the long term effect of thymectomy for patients with myasthenia gravis. METHODS: Patients with myasthenia gravis 4 - 54 months after thymectomy were followed up. RESULTS: 124 patients with myasthenia gravis were treated by thymectomy from April 1990 to August 1994. The mean age at the time of surgery was 29.2. According to the modified Osserman classification. 29 patients were type I, 23 type II a, 41 type II b and 11 type III. After thymectomy 82.7% patients had good response to the operation. 13.5% had no response and 1.9% were even worse. Of 104 patients followed up, no early death was found and late death occurred in 2. Type II patients and those with shorter preoperative course responded better. CONCLUSIONS: The surgical outcome is related to clinical classification of myasthenia gravis and the duration of preoperative period. Sex and pathologic type of thymus lesion seem to be irrelevant factors to the surgical outcome. To perform thymectomy or not should be very carefully weighed for patients younger than 10 years of age.

Adolescent↗

PubMed1999

[A scanning method for detecting colorectal tumors].

OBJECTIVE: To develop a method for survey of colorectal tumors. METHODS: Mucus obtained by digital rectal examination was smeared on a slice to react with peanut agglutinin labeled by Horseradish-peroxidase. RESULTS: Brown color was noted in positive reaction. In detecting colorectal tumors, the sensitivity and specificity of the method was 88.2% and 92.5% respectively. CONCLUSION: The method is effective in detecting colorectal tumors in humans.

Adult↗

PubMed1999

[A study on ocular anterior segment structure after scleral buckling surgery for retinal detachment].

OBJECTIVE: To study the changes of the ocular anterior segment structure and the mechanism of angle-closure glaucoma after scleral buckling surgery. METHOD: 30 patients (33 eyes) who suffered from rhegmatogenous retinal detachment had been observed before and 3 - 7 days after the surgery. The quantitative measurement of the ocular anterior segment structure in vivo had been done by ultrasound biomicroscopy (UBM). The results were statistically analyzed. RESULTS: There was one eye with split-like ciliary body detachment before the surgery, there were 11 eyes with ciliary body detachment (33.3%) and the ciliary body was thickened and edematous after surgery. Before the surgery the thickness of the ciliary body was (821.32 +/- 64.21) microm and after the surgery it was (945.27 +/- 104.16) microm, the difference being statistically significant, P < 0.05. Parameters reflecting the changes of the anterior chamber angle before and after surgery were as follows: the anterior chamber angle became narrower, the angle open distance 500 decreased, the trabecular-iris angle decreased in degree, the angle of the scleral lateral side and iris long axis decreased, and all these differences were statistically significant, P < 0.05, but the depth of the central anterior chamber had no obvious change, and the difference was not statistically significant, P > 0.05. CONCLUSIONS: Ciliary body detachment and edema are often found after scleral buckling surgery, and post-operatively the central anterior chamber depth has no obvious change; ciliary body detachment and edema perhaps are related to the angle-closure glaucoma after the surgery.

Adolescent↗

PubMed1999

[Optical coherence tomography of macular holes].

OBJECTIVE: To study the characteristics and clinical application value of the optical coherence tomography (OCT) of macular holes. METHOD: A total of 35 patients with the clinical diagnosis of macular hole were examined with OCT between September and December 1998. OCT imaging was conducted through a dilated pupil, and the OCT images were analyzed and measured. RESULTS: Of the 35 patients examined with OCT, there were pseudohole and epimacular membrane in one eye, vitreofoveal traction in one eye, macular holes in 36 eyes, and 3 patients had macular hole in bilateral eyes. In 4 eyes, there were partial-thickness macular holes, and the defect of partial thickness of neural epithelium in the fovea without halo of retinal detachment was shown in the OCT image. In 32 eyes, there were full-thickness holes; the OCT displayed complete losing of the whole thickness of the neural epithelium in the fovea, sharp edge of the hole and the halo of retinal detachment around the hole. Sometimes nonreflective cavities could be seen within the retina, and the retinal thickness around the hole was increased. According to Gass stage classification of macular hole, there were 2 eyes with impending hole, 3 eyes in stage 2, 15 eyes in stage 3 and 6 eyes in stage 4. 4 eyes underwent vitrectomy. The OCT imaging after the surgery demonstrated the closure of hole and the disappearance of halo surrounding the hole. Through quantitative measurement, the diameter of the hole was (565.88 +/- 40.35) microm, the diameter of the halo was (1,338.76 +/- 147.57) microm, and the retinal thickness surrounding the hole was (391.87 +/- 18.97) microm. The sizes of the hole and the halo and the retinal thickness around the hole were correlated with the vision. CONCLUSION: OCT is a novel noninvasive, noncontact imaging technique. It is helpful in the diagnosis and differential diagnosis of the macular hole; the progress of the hole can be quantitatively estimated, and it is also helpful in selection of operation and assessment of operative therapeutic effects.

Adult↗

PubMed1999

[Ocular pharmacokinetics of pilocarpine micron emulsion in rabbits].

OBJECTIVE: To compare the pharmacokinetics of pilocarpine micron emulsion with generic pilocarpine solution in the aqueous humor. METHODS: 60 albino rabbits were used and were divided into 20 groups, each consisting of 3 animals. 10 groups received 2% generic pilocarpine 50 microl as controls; 10 groups received 50 microl of 2% pilocarpine micron emulsion in the conjunctival sac. The aqueous humor was withdrawn at 5, 10, 30, 40, 60, 90, 120, 180, 240 and 360 min. after instillation. The drug was extracted from aqueous humor with dichloromethane. The drug was analyzed by reversed phase high pressure liquid chromatography (HPLC). RESULTS: Pilocarpine micron emulsion therapy gave higher aqueous humor concentration of the drug than drops at all time periods tested except 5 min. time point (P = 0.0003 - 0.042). The area under curve of micron emulsion was 3 times as much as that of drops. There was a two-fold increase in ocular bioavailability of pilocarpine due to the therapy with micron emulsion. Measurable amounts of drug following 2% micron emulsion were still observed at 360 min. while drug levels at 180 min. following 2% drop therapy were nil. CONCLUSION: Our study results demonstrated significantly increase in ocular bioavailability of pilocarpine due to the therapy with micron emulsion. Our finding indicates that a novel topical preparation of pilocarpine incorporated in micron emulsion might serve as a long acting antiglaucoma agent, and less frequent applications are necessary with it than with conventional drops.

Animals↗

PubMed1999

[Studies on appropriate methods for dust scrubbing from dust-laden gas in shaft kilns of small-sized cement plants].

OBJECTIVE: To study an appropriate method for dust scrubbing from dust-laden gas in the shaft kilns of small-sized cement plants. METHODS: Characteristics of dust-laden gas, including its temperature, dew point, dust concentration, diameters of dust particles and their distribution, as well as fractional dust collection efficiencies of the dust precipitator settling chamber, cyclone, impinging scrubber, impinging-spray scrubber, were measured according to the National Standards for Measurement of Particulate in Exhaust Gas Emitted from the Stationary Pollution Sources and Sampling Methods of Gaseous Pollutants (GB/T16157 - 1996), with a WY-1 In-stack 7-Stage Cascade Impactor for fractional dust collection. RESULTS: The fractional dust collection efficiency of the settling chamber for the particles greater than 12 microm was 72%, while that of the cyclone for the particles of 2 microm, 5 microm and 10 microm were 40.0%, 72.5% and 88.9%, respectively, and that of impinging scrubber was 55.0%, 91.0% and 98.9%, respectively; and that of impinging-spray scrubber were 96.0%, 99.2% and 99.6%, respectively. Results showed that 81% of the dust (by weight) from the shaft kilns were greater than 10 microm, so the settling chamber was effective for the removal of this fraction of dust. But dust particles behind the settling chamber were finer, and about 59% - 69% of them were less than 2 microm in diameters. In that case, the cyclone, impinging scrubber and impinging-spray scrubber could give an overall collection efficiency of 54%, 57% and 96%, respectively. Based on this, the following combination of dust collectors were adopted to meet the national standards for exhaust emission: a settling chamber plus an electrostatic precipitator, a settling chamber plus an impinging-spray scrubber and a settling chamber plus an impinging scrubber. The cement plants could select appropriate dust collectors according to their technical and economical conditions. CONCLUSION: Based on the results of the studies, appropriate dust collectors used to treat dust-laden gas from shaft kilns to meet the national standards for exhaust emission were recommended.

Air Pollutants, Occupational↗

PubMed1999

[Expression of angiogenic factors and cell cycle regulation factors in human glioblastoma cell line SHG-44].

OBJECTIVE: To investigate the biological features and immunophenotypes of human glioblastoma cell line SHG-44 after long term passage. METHODS: Immunohistochemistry and in situ hybridization were used to study the proliferative activity, intermediate filament protein coexistence, expressions of oncoprotein, angiogenic factors and cell cycle regulation factors. RESULTS: After 130 to 150 passages, SHG-44 cells were weakly positive for glial fibrillary acidic protein (GFAP), but strongly positive for vimentin. The labeling index of Ki-67 and PCNA were 83.5% +/- 10.2% and 70.0% +/- 18.7% respectively. Overexpression of p21 ras, c-erbB-2, epidermal growth factor (EGF) and EGF receptor were obtained. Basic fibroblast growth factor (bFGF), FGF receptor, vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) were also up-regulated in this cell line. p16, p53, cdk4 and cyclin D1 could be detected in the cells and their indices were 43.1% +/- 11.2%, 20.7% +/- 6.6%, 33.1% +/- 11.4% and 29.2% +/- 4.7% respectively. CONCLUSION: Expressive abnormalities of these growth factors, their receptors and the above oncoproteins as well as disorders of cell cycle regulation contribute to the rapid growth and high degree of malignancy of this cell line.

Angiogenesis Inducing Agents↗

PubMed1999

[Construction of three transgenic vectors carrying the latent membrane protein gene of Epstein-Barr virus].

In order to produce transgenic mice carrying the latent membrane protein(LMP) gene of Epstein-Barr virus(EBV) and to study the oncogenic role of LMP gene in vivo, three different transgenic vectors carrying the LMP gene were constructed. In pBR322-MT-LMP vector, the promoter of LMP gene is the regulation region of mouse metallothionein-I gene. In pMci3-LMP shuttle vector, the promoter of LMP gene is the replication origin(oriP) of EBV. In pMV-LMP-c-myc retroviral vector, the long terminal repeat (LTR) of mouse sarcomavirus serves as the promoter of LMP gene. The characterization and usefulness of these three transgenic vectors are also discussed.

Animals↗