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Biomedical subjects

L Wang

Publications and source records attributed to L Wang.

At least 1,333 records · Page 74Linked to original sources
PubMed1998

Cathepsin B on invasion and metastasis of gastric carcinoma.

OBJECTIVE: To investigate the expression of cathepsin B (CB) in human gastric carcinoma tissue. METHODS: The expression of CB in human gastric tissue was studied by using monospecific polyclonal rabbit antibody raised against human liver CB for immunohistochemistry, and full length cDNA of CB for in situ hybridization and dot blot. RESULTS: CB overexpression in gastric carcinoma was found when compared with non-neoplastic gastric tissue at both mRNA and protein levels. Diffuse cytoplasmic CB staining of mRNA and protein were identified in malignant cells of 53.3% and 69.1% of gastric adenocarcinoma respectively. The increased staining of CB in malignant cells was associated with the depth of the invasiveness and growth pattern as well as metastasis of lymph nodes, but not with the histological classification. It was also found that there were the expression of CB in stromal cells of the tumor and the expression localized mainly in the endothelial cells of the microvessels which correlated with angiogenesis. CONCLUSION: These results indicate that the expression of CB in gastric carcinoma is related to tumor progression, and leads to development of the invasive phenotype.

Adenocarcinoma↗
PubMed1998

[Analysis of the relations between Toynbee phenomenon and middle ear pressure].

This paper studied the relations between the middle ear pressure, the opening duration of eustachian tube (ET), and the duration of nasopharyngeal pressure phase during Toynbee maneuver by sonotubometry, tympanometry and nasopharynx manometry. The mucociliary clearance of ET in Toynbee maneuver was also studied by Saccharin method. The results showed that negative middle ear pressure induced by Toynbee maneuver was related to prolonged opening duration of ET and duration of negative pressure in nasopharynx and lower opening pressure of ET. This phenomenon was often shown on the patients with nasal obstruction, and reduced ET mucociliary clearance. The Toynbee phenomenon indicates a closing failure of the ET, clinically, this situation needs to be prevented and resolved in a timely manner.

Adolescent↗
PubMed1998

[Studies on the committed differentiation of CD34+ hematopoietic progenitor cells].

OBJECTIVE: To elucidate the capacity of different hematopoietic growth factors (HGFs) combinations for inducing CD34+ cells to proliferate and differentiate committedly to granulocytes, erythrocytes, megakaryocytes and dendritic cells (DC). METHODS: CD34+ cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system (MACS), and expanded with HGFs in a liquid culture system. Colony forming cells and antigen expression were studied by colony forming assays and FACS. RESULTS: Different combinations of HGFs, including SCF, IL-3, IL-6, GM-CSF, Epo and Tpo increased BFU-E, CFU-GM, CFU-MK and CD41a+ cells by 14.97 +/- 2.89 fold, 14.46 +/- 3.19 fold, 34.67 +/- 4.62 fold and 17.29 +/- 2.34 fold, respectively. Combination of HGFs allowed generation of a large number of DCs. Cultures of CD34+ cells with the combination of FLT-3 ligand + GM-CSF + IL-4 + TNF-alpha yielded 24.28% +/- 2.14% CD1a+ cells, while the control cultures did not. CONCLUSION: It is possible to induce CD34+ cells to proliferate and differentiate committedly to different lineage of hematopoietic cells and DC.

Antigens, CD34↗
PubMed1998

[Study on expression of Evi1 and MDS1-Evi1 genes in myelodysplastic syndromes].

OBJECTIVE: To investigate expression of Evi1 and MDS1-Evi1 genes in myelodysplastic syndromes (MDS) and its role in pathogenesis of MDS. METHODS: Expression of Evi1 and MDS1-Evi1 genes was examined in 31 MDS, 11 post MDS acute myeloid leukemia (post MDS AML) and 34 de novo AML patients by a semi-quantitative RT-PCR. RESULTS: Evi1 expression was not detected in 8 normal controls, but low MDS1-Evi1 expression levels (MDS1-Evi1/GAPDH < 0.1) detected in 3 of the 8 controls. Evi1 mRNA was expressed in 1 of 8 RA, 8 of 13 RAEB and 6 of 9 RAEB-t patients, and the percentage of Evi1 expression in RAEB(t) patients was higher than that in RA(P < 0.05). MDS1-Evi1 expression was detected in 5 of 8 RA, 9 of 13 RAEB and 5 of 9 RAEB-t patients, and MDS1-Evi1 expression levels (MDS1-Evi1/GAPDH > 0.1) in the patients were markedly higher than those in the controls. Evi1 expression was gradually increased in 4 of 5 RAEB-t patients with transformation from MDS to AML. The percentages of Evi-1 and MDS1-Evi1 expression in post MDS AML patients were higher than those in de novo AML (P < 0.01 and P < 0.05, respectively). The numbers of colony formation of progenitor cells in Evi1 and MDS1-Evi1-positive MDS patients were decreased as compared with Evi1 and MDS1-Evi1-negative patients. CONCLUSION: Abnormal expression of Evi1 and overexpression of MDS1-Evi1 might play a certain role in the pathogenesis or progression of MDS and post MDS AML.

Adult↗
PubMed1998

Glycophorin variants and contents of sialic acid and total sulfhydryl groups on erythrocyte membranes of residents in a malaria hyperendemic area.

OBJECTIVE: To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province. METHODS: GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS-PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively. RESULTS: Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group; while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72). The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P < 0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P < 0.05). CONCLUSIONS: The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.

Adolescent↗
PubMed1998

[Changes in distortion product otoacoustic emissions and hair cells after noise exposure in guinea pigs].

In order to observe the changes in distortion product otoacoustic emissions (DPOAE) and hair cells after noise exposure, sixteen healthy guinea pigs were used. The animals were divided into 3 groups. Group 1 was normal animals. Group 2 and 3 were animal right and 7 days after exposed to 115 dB SPL simulated submarine engine room noise for 4 hours, respectively. The DPOAE audiogram and I/O function were measured before and after exposure. The changes of hair cells were observed by light microscope and scanning electron microscope. The amplitudes of DPOAE disappeared right after noise exposure(P < 0.01) and recovered to normal at 7 days after exposure (P > 0.05). The light microscopy and scanning electron microscopy showed the stereocilia of the outer hair cells were disarrangement and some disappeared at 2,3,4 kHz regions of the cochlea. The results indicated that the normal outer cells can regulate and compensate the function of some damaged outer hair cells which result in a normal DPOAE in mild damaged cochlea.

Animals↗
PubMed1998

[Effect of WT1 gene expression on cell growth and proliferation in myeloid leukemia cell lines].

OBJECTIVE: To explore the effect of WT1 antisense oligonucleotide(AS-oligo) on cell proliferation and apoptosis in myeloid leukemia cell lines. METHODS: K562 and HL-60 cells were cultivated with WT1 AS-oligo. The cell proliferation, apoptosis, cell cycle and gene expression were examined by MTT colorimetry, FACS and RT-PCR. RESULTS: WT1 AS-oligo could inhibit the proliferation of K562 cell and induce apoptosis of K562 and HL-60 cells. On the contrary, the growth of HL-60 cells and the expression of WT1, mdm2 and bcl-2 genes were unaffected. CONCLUSION: WT1 gene is related to the proliferation and apoptosis of leukemic cells. WT1 gene could suppress cell apoptosis independent of status of p53 and bcl-2 genes. It might play an role in leukemogenesis.

Apoptosis↗
PubMed1998

[Study on gene expression of TGF beta 1 and its receptor in leukemia cells and the serum TGF beta 1 level in the patients with acute leukemia].

OBJECTIVE: To investigate the mechanism by which TGF beta 1 inhibits the growth of leukemic cells and the significance of serum TGF beta 1 level in acute leukemia(AL) patients. METHODS: RT-PCR was used to detect gene expression of cytokines including IL-1, IL-3, IL-6, TGF beta 1 and their receptors (R) in leukemic and normal cells. Leukemic colony assay was carried out to determine the effect of TGF beta 1 on the growth of leukemic cells and the serum TGF beta 1 level in 33 AL patients were measured by ELISA. RESULTS: TGF beta 1 was found to significantly inhibit the proliferation of leukemia cells of HL-60, K562 and DAMI cell lines. Furthermore, a variety of leukemia cell lines including HEL, HL-60, K562, U937, DAMI, MEG-01, HUT78 and CA were found to express mRNAs for TGF beta 1 and its receptor. In addition, TGF beta 1 was found to be able to evidently down-regulate the expression of mRNAs for IL-6, IL-6R, IL-3, GM-CSFR in DAMI cells and, interestingly, up-regulate TGF beta 1 gene expression in the cells per se before the cells showed DNA fragmentation, a molecular hallmark for cell apoptosis. It was shown that serum TGF beta 1 levels were significantly decreased in leukemic patients, restored to normal in the patients achieved complete remission, and tended to decrease again in the recurrent patients. CONCLUSION: 1. TGF beta 1 may act as an inhibitory autocrine factor in the proliferation of leukemia cells; 2. the mechanism by which TGF beta 1 inhibits the growth of leukemia cells involves its down-regulating expression of positive cytokines and receptors and up-regulating TGF beta 1 expression in leukemia cells per se; 3. serum TGF beta 1 is a valuable parameter in monitoring the prognosis of leukemia and weakened control of TGF beta 1 on leukemia cells may play an important role in the pathogenesis of AL.

Adult↗
PubMed1998

Experimental study on liver microcirculation disturbance following transplantation and the protective effect of prostaglandin E1 in the rat.

OBJECTIVE: To determine the effect of PGE1 on liver microcirculation disturbance following orthotopic liver transplantation in rats. METHODS: Forty male adult Wistar rats were divided randomly into 3 groups. Eight transplantations were established in both the experimental and control group, while in the sham group, the liver was dissected like in the experimental group, but no resection was performed. In the experimental group, PGE1(0.5 microgram/kg.min-1) was injected intravenously into the donor before the operation, and added (1 mg/L) to the flush and preservation fluid, while PGE1 was replaced by normal saline in the control group. Confocal laser scan microscopy, biochemical test, and optical and electronic microscopy were used. RESULTS: In the control group the reperfusion state was poor, leukocyte infiltration appeared in the center of lobule, and transaminase rose after transplantation. In the experimental group distinctive improvement was seen as compared with the control group (P < 0.05). Histological findings showed progressive degeneration and necrosis following transplantation in the control group, while in the experimental group the histological changes were improved to some degree by the use of PGE1. CONCLUSIONS: In liver transplantation, ischemic reperfusion damage may lead to hepatic microcirculation disturbance, which is the major cause of graft failure. Infusing PGE1 into the donor intravenously before ischemia and adding PGE1 to the cold storage fluid could improve hepatic microcirculation, and thus reducing ischemic reperfusion damage in liver transplantation.

Alprostadil↗
PubMed1998

[Detection of oncogenic mutations in sputum and its diagnostic value of lung cancer].

OBJECTIVE: To find a new method to molecular biological detection of lung cancer. METHOD: The sputum specimens from 96 cases of lung cancer and other lung patients were detected for K-ras and p53 mutations by using polymerase chain reaction(PCR) and restriction fragment length polymorphism and and immunohistochemistry (IHC) techniques. RESULT: 38 out of 62 sputum specimens of lung cancer patients were positive for cytology: Sensitivity was 61%. NPV (negative predictive value) was 59%; p53 was overexpressed in 48 cases: Sensitivity was 77%. NPV was 66%; k-ras was positive in 21 cases: Sensitivity was 34%, NPV 42%; The combination of conventional cytology and molecular screening(k-ras + p53) produced a sensitivity value of 92%(P < 0.05) with an NPV of 84%(P < 0.05); In 24 cases of patients whose cytology of sputum was false negative, 17 were found either p53 or k-ras positive of which 7 patients were identified to be lung cancer in the follow-up study. CONCLUSION: These results suggest that detection of oncogene mutation in sputum enhanced and added to the diagnostic value of conventional cytology. It is a promising approach to early lung cancer detection and massive screening in terms of its rapidity, economy and simplicity.

Adenocarcinoma↗
PubMed1998

[Effect of Tripterine on mRNA expression of c-myc and platelet derived growth factor of vascular smooth muscle cell in rats].

OBJECTIVE: To observe the effect of Tripterine on mRNA expression of c-myc and platelet derived growth factor (PDGF) in vascular smooth muscle cell (VSMC) of rats. METHODS: 5-10th passage culture of VSMC was used. Tripterine and 20% fetal calf serum were added into the medium of cultured VSMC in concentration of 0.1, 0.2 and 0.3 mg/L after free-serum cultivation for 24 hours. The general RNA was isolated from VSMC at 6 and 12 hours after the drug addition for detection of mRNA expression of c-myc and PDGF respectively by dot blot hybridization. The cDNA probes were labeled by digoxin. RESULTS: Tripterine inhibited the PDGF mRNA expression of VSMC and decreased c-myc mRNA expression in a dose-dependent manner, either vs. control. CONCLUSION: Tripterine could inhibit mRNA expression of c-myc and PDGF in VSMC, therefore, it would inhibit overproliferation of VSMC.

Animals↗
PubMed1998

[Effect of Sancai injection on red blood cell line in mice].

OBJECTIVE: To study the effective mechanism of Sancai Fensui Dan in mice. METHODS: Sancai injection (SCI) was given to normal or anemia mice and their hemoglobin (Hb), red blood cell (RBC), reticulocyte (Ret) of peripheral blood, mitosis index (MI) of red cells, bone marrow nucleated cell (BMC) were measured. And the cultured hemopoietic progenitor cells of burst forming unit-erythroid (BFU-E) and colony forming unit-erythroid (CFU-E) were used to observe the hemopoiesis effect of SCI. RESULTS: SCI could promote the increase of Hb, RBC, Ret, MI and BMC in anemia mice. At the presence of spleen cells or macrophages in peritoneal cavity, it could enhance the proliferation of BFU-E and CFU-E. CONCLUSION: SCI could promote hemopoiesis by activating the hemo-opsonin.

Anemia↗
PubMed1998

[Therapeutic effect of Shengmai injection on respiratory function in chronic obstructive pulmonary disease].

OBJECTIVE: To explore the therapeutic effect of Shengmai injection (SMI) on respiratory function in chronic obstructive pulmonary disease (COPD). METHODS: Twenty patients with COPD were continuously treated with SMI by intravenous drip in 14 days and examined the lung vital capacity (VC), forced vital capacity (FVC), forced vital capacity of the first second (FEV1), FEV1/FVC, maximum voluntary ventilation (MVV), maximum inspiratory pressure (MIP), load respiratory time (LT), 6 minute walk distance (6 MWD), arterial blood gas analysis, and Brog dyspnea scale before and after treatment respectively and compared with itself or control group. RESULTS: After treatment all parameters of the treatment group were better than those of control group or itself before treatment except for FVC and FEV1/FVC. There were significant difference (P < 0.05). CONCLUSION: SMI can improve respiratory function in COPD. So it is an effective rehabilitative measure in treating COPD.

Aged↗
PubMed1998

[Analysis of heart rate variability in Chinese healthy pilot].

Normal range of 24 h heart rate variability (HRV) and its application in healthy pilots of different age and sex were investigated. 24 h HRV data in 118 healthy male and female pilots and ground crew were measured. Comparing with male pilots, SDNN, HRVi, RMSSD, HF and ATP values in females are obviously higher (P < 0.05). For HRV comparison analysis, the pilots were divided into three age groups. The results show that SDNN value of male pilots in group A is obviously higher than those in group B and C (P < 0.01). In female pilot group, the RMSSD, HF and ATP values of group C, are obviously higher than those of A and B (P < 0.01). It demonstrates that many HRV parameters show significant difference between male and female pilots, the HRV parameters in female pilot are obviously higher than those in males, especially for such parameters which reflect vagal nerve activity. Age factor effect is apparent in pilot's HRV data. Some HRV parameters in different age groups show significant difference. Most 24 h HRV parameters in pilots flying different types of aircraft show no significant difference.

Adult↗
PubMed1998

[Analysis of time domain and frequency domain heart rate variability in fighter pilot before and after upright tilt].

Effects of upright tilt on mechanism of autonomic nervous regulation of cardiovascular system and characteristics of heart rate variability (HRV) were observed in sixty healthy male pilots. Relation between time domain and frequency domain indexes of short-time HRV (5 min) were analysed before and after upright tilt. The results showed that there are significant difference in short time HRV parameters before and after upright tilt. Significant relationship was formed between time domain and frequency domain indexes of HRV. It suggests that time domain and frequency domain HRV analysis is capable of revealing certain informations embedded in a short series of R-R intervals and can help to evaluate the status of autonomic regulation of cardiovascular function in pilots.

Adult↗