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Biomedical subjects

S Chen

Publications and source records attributed to S Chen.

At least 613 records · Page 34Linked to original sources
PubMed1999

[Antisense oligonucleotides inhibit c-myc and PCNA expression in the vascular smooth muscle cells].

OBJECTIVE: To study the methods for prevention and treatment of vascular restenosis. METHODS: We used two factors which result in hyperplasia of vascular smooth muscle cells (VSMCs) and applied antisense c-myc, PCNA oligonucleotides to attenuate the expression of their related gene. The sense, antisense, and mismatched oligomers for c-myc or PCNA were designed and synthesized. They were individually delivered to the cultured VSMCs after the oligomers were stable in culture medium for 5 days and could cross the plasma membranes into the cells. Using RT-PCR and the image analysis system, we observed the changes of both c-myc and PCNA gene expression in the VSMCs. RESULTS: Antisense c-myc and PCNA at a concentration of 10 mumol/L were able to inhibit the expression of c-myc and PCNA gene in VSMCs (P < 0.05), whereas the sense and the mismatched ones couldn't inhibit the expression (P > 0.05). CONCLUSION: The antisense technique is an effective method for the inhibition of VSMCs proliferation.

Animals↗
PubMed1999

Three-dimensional electron beam CT angiography in the diagnosis of intracranial aneurysms.

OBJECTIVE: To assess the accuracy of three-dimensional electron beam CT angiography (3D-EBCTA) in the detection of intracranial aneurysms. METHODS: 31 patients with suspected cerebral aneurysms (including 3 post-operative patients) were examined by 3D-EBCTA. Those receiving angiography or surgery acted as controls. Maximum intensity projection (MIP) and shaded surface display (SSD) reconstruction ways were selected. RESULTS: 24 aneurysms were found in 23 patients. Of the 31 patients, false positive was noted in 1 patient, and false negative in 2 on 3D-EBCTA. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 92.0%, 88.9%, 91.2%, 95.8% and 80.0% respectively. CONCLUSION: 3D-EBCTA is an noninvasive, rapid, valuable method in diagnosis and screening of patients with suspected aneurysms. The reconstruction modes such as MIP and SSD should be used together to optimise the visualization.

Adult↗
PubMed1999

[The feature of T cell clonality with polycythemia vera].

OBJECTIVE: To investigate the expression and clonality of TCR V beta subfamily genes in the T cells in polycythemia vera. METHODS: The 24 genes of the TCR V beta subfamily were amplified with peripheral blood mononuclear cells from 3 cases of polycythemia vera(PV) by RT-PCR, then the PCR products were further analyzed by genescan technique to evaluating the clonality of the detectable TCR V beta T cells. RESULTS: Only 4-14 of the 24 V beta subfamily T cells were found in the 3 PV cases, the commonly expressed V beta subfamily genes were V beta 2, V beta 3, V beta 16, V beta 21 and V beta 23. Two clonal T cells of V beta 3 and V beta 23 were identified in 2 cases. CONCLUSIONS: The skew distribution and clonal expansion of TCR V beta subfamily T cells in patients with polycythemia vera might be a feature of the immune response for malignant cells.

Cloning, Molecular↗
PubMed1999

Expression of leukocyte adhesion molecules CD11b, L-selectin and CD45 during hemodialysis.

OBJECTIVE: To examine the gene and protein expression of CD11b, L-selectin and CD45, and the relationship between their expression and leukocytopenia during a hemodialysis session. METHODS: Ten maintenance hemodialysis patients, 20 uremic non-dialysis patients and 10 healthy volunteers were included in this study. The mRNA expression of CD11b, L-selectin and CD45 in peripheral blood mononuclear cells was detected by RT-PCR, while cell surface expression of these molecules on monocytes was detected by flow cytometry and leukocyte number was counted manually. RESULTS: After the start of dialysis, both mRNA expression and cell surface expression of CD11b increased rapidly, while those of L-selectin and leukocyte number fell. The mRNA expression of CD45 first decreased and the cell surface expression increased, followed by a return to pre-dialysis levels, by the end of dialysis. CONCLUSIONS: Hemodialysis using a cuprophane membrane can induce rapid upregulation of CD11b and down-regulation of L-selectin, which might influence the normal adhesion and anti-inflammatory response of leukocytes. In this process CD45 may play a role in regulating and/or transducing activation signal.

Adult↗
PubMed1999

Differentiation therapy for acute promyelocytic leukemia with all-trans retinoic acid: 10-year experience of its clinical application.

PURPOSE: To summarize the experiences in using all-trans retinoic acid (ATRA) for the differentiation therapy for acute promyelocytic leukemia (APL) since our introduction of its use in clinic in 1986. DATA RESOURCES: Data resources came from Chinese Journal of Hematology, English-language literature using MEDLINE (1988-1998), book entitled "Treatment of Malignancies by Inducing Differentiation and Apoptosis" published by Shanghai Publishing House on Sciences and Technology, and our recent data to be published. STUDY SELECTION: Thirty-five articles related to the purpose of this review were reviewed. DATA EXTRACTION: Data were checked for their quality, reliance and originality. RESULTS: ATRA combined with chemotherapy can decrease the incidence of retinoic acid syndrome and produce a very high remission rate (90%-95%). Post-remission treatment should include chemotherapy and ATRA, the 5-year survival probability was able to attain 0.71 +/- 0.06. The main problem in the treatment is early tolerance to ATRA and relapse of the disease. The most effective treatments for relapsed APL is to use arsenic trioxide. CONCLUSION: The combination of ATRA, chemotherapy and arsenic oxide in the treatment of APL for elevating the remission rate and prolonging survival time deserves further study.

Antineoplastic Agents↗
PubMed1999

[Combination therapy of murine liver cancer with IL-12 gene and HSV-TK gene].

OBJECTIVE: To investigate the synergistic antitumor effects of murine IL-12 gene and HSV-TK gene therapy in mice bearing liver cancer. METHODS: Mouse liver cancer MM45T. Li (H-2d) cells were transfected with retroviral vector containing IL-12 gene or HSV/TK gene insert. Gene-modified liver cancer cells, MM45T. Li/IL-12 and MM45T. Li/TK, with stable expression of IL-12 and TK were obtained. Balb/c mice were inoculated subcutaneously with 2 x 10(5) MM45T. Li Cells. When the tumor reached a size of 0.5-1.0 cm, a mixture of MM45T. Li/TK cells and 60Co-irradiated MM45T. Li/IL-12 cell were injected intratumoraly. Ganciclovir (GCV) was injected i.p. (40 mg.kg-1.d-1) for 10 days. Intratumoral injection of 60Co-irradiated MM45T. Li/IL-12 cells was repeated twice in one week apart. Mice with distant tumors were treated according to the same protocol. CTL activity of spleen cells was measured by 51Cr-release assay and phenotype of tumor infiltrating lymphocytes by immunohistochemical staining. RESULTS: In mice treated with MM45T. Li/IL-12 or MM45T. Li/TK + GCV individually led to moderate reduction in tumor growth, but neither could eradicate the tumor completely, while in 60% of mice treated with a mixture of MM45T. Li/IL-12 and MM45T. Li/TK cells plus GCV, complete tumor regression was observed, with no tumor recurrence for two months. The growth of distant tumor was also inhibited significanty in mice similarly treated. Most of the mice received combined gene therapy plus GCV had abundant CD4+, CD8+ T lymphocyte infiltration. Their CTL activity was significantly higher than in mice received single gene therapy. CONCLUSION: Combination therapy with IL-12 gene and HSV-TK gene + GCV is effective for mouse liver cancer.

Animals↗
PubMed1999

[Experimental study on the effect of yiyuan shengxue capsule on gamma-interferon and tumor necrosis factor-alpha in patients with chronic aplastic anemia].

OBJECTIVE: To explore the effect of Yiyuan Shengxue capsule (YYSXC) on peripheral gamma-interferon (gamma-IFN) and tumor necrosis factor-alpha (TNF-alpha) in patients with chronic aplastic anemia (CAA). METHODS: Applying the assay of microcell lesion inhibitory and L595 cytotoxicity test to detect gamma-IFN and TNF-alpha level 36 thirty-six cases with CAA before and after treatment with YYSXC. RESULTS: To compare the test group with the normal group, the difference was significant before treatment (P < 0.05, P < 0.01), but after treatment, the difference was insignificant between these two groups (P < 0.05). To compare the group of Kidney Yin Deficiency with Kidney Yang Deficiency, both the difference of before and after treatment were significant. For the therapeutic effective rate, the group of Kidney Yang Deficiency was higher than that of Kidney Yin Deficiency. CONCLUSION: YYSXC could treat CAA through reducing the level of peripheral gamma-IFN and TNF-alpha of CAA patients, and the effect was through regulating the dysfunctional immune state.

Adolescent↗
PubMed1999

[Effects of kidney nourishing and spleen invigorating recipes on glucocorticoid receptors of pulmonary tissue and plasma corticosterone in asthmatic rats].

OBJECTIVE: To observe the effects of Guiqi San (GQS, a Chinese herbal preparation with effect of Kidney Nourishing and Spleen Invigorating), Bushen Dingchuan Tang (BSDCT, with effects of Kidney Nourishing) and Liujunzi Tang (LJZT, with effect of Spleen Invigorating) on glucocorticoid receptor (GCR) and plasma corticosterone (PCC) in asthmatic rats. METHODS: The asthmatic model of rats made by intraperitoneal injection of ovalbumin two weeks before, and the asthma consecutively challenged daily with spray inhalation of 1% ovalbumin for 7 days. The asthmatic rat treated with above-mentioned three recipes (per os) and Beclomethasone dipropionate (BDP) were taken as treated groups and the asthmatic rat as control group. GCR density of the pulmonary tissue and PCC were determined by radioligand-binding assay and competitive protein radio-binding assay. RESULTS: The RT value of GCR reduced gradually and PCC lowered also after asthma being developed. On day 7th, the three recipes could markedly up-regulate the RT of GCR and PCC. There was significant difference statistically as compared the pulmonary tissue GCR density and PCC of GQS (P < 0.01, P < 0.05), BSDCT (P < 0.05, P < 0.05) and LJZT (P < 0.05, P < 0.05) groups with those of control (asthmatic group) on the 7th day. CONCLUSION: GQS, BSDCT and LJZT played an up-regulate role of GCR density and improvement of adrenocortical function in asthmatic rats in the management of asthma attacks.

Animals↗
PubMed1999

[Clinical study on acute upper respiratory tract infection treated with qingkailing injection].

OBJECTIVE: To explore the effect of Qingkailing injection (QKLI) in treating acute fever. METHODS: Four hundred cases of acute upper respiratory tract infection were divided into three groups treated with QKLI 120 ml/d, 160 ml/d and 200 ml/d respectively, and compared with a control group treated with lincomycin 1.8 g/d. RESULTS: The markedly effective rate of QKLI was 84.14% which was better than that of lincomycin (75.83%). The mean initial time of QKLI (12.6 h) was shorter than that of lincomycin (17.6 h). Effect of QKLI on patients with disease course within one day was better than that within 3 days. No significant difference revealed between effects in groups treated with different dosage of QKLI. The effect of QKLI in lowering white blood cell count was similar to that of lincomycin. For patients with positive throat swab culture of pathogenic bacteria, QKLI displayed good antibacterial action in vivo. CONCLUSION: QKLI is a highly effective with rapid action drug for treatment of acute respiratory infection.

Adult↗
PubMed1999

[Origin and progress of myelodysplastic syndrome with hypoplasia].

OBJECTIVE: To study the origin and progress of myelodysplastic syndrome (MDS) with hypoplasia. METHODS: The data of twenty-five cases of hypomyeloplastic MDS diagnosed by our department in the last ten years were analyzed. 17 of the 25 cases were followed up for a long time. RESULTS: (1) The percentage of hypomyeloplastic MDS was 11.4% of the total 219 MDS patients. The median age of the 25 cases was (44.8 +/- 14.7) years. (2) FAB subtype: There were 11 cases of RA and 14 of RAEB. (3) Hypomyeloplastic MDS seems to be a developmental phase in the clinical course in some of the patients and not a special type of MDS. Hyper- and hypo-myeloplasia could be transformed from one to another. The transformation of myelodysplasia could occur either in the same or and different FAB subtype. (4) Seven of the seventeen cases transformed to acute leukemia (41.2%), 6 cases were AML and 1 was ALL. 3 of the 7 cases transformed to hypomyeloplastic leukemia and the remaining 4 transformed to hypermyeloplastic leukemia. (5) The median time from the diagnosis of RAEB to leukemia transformation, was 27 months in 7 cases with hypoplastic RAEB. (6) No relationship was found between therapeutic medicines and development of hypomyeloplastic MDS. CONCLUSION: It is suggested that hypomyeloplastic MDS is probably a developmental phase in the clinical course of MDS, but not a special type.

Adult↗
PubMed1999

[Ankylosing spondylitis in Shantou: clinical experience in fifteen years].

OBJECTIVE: To evaluate the clinical features of ankylosing spondylitis (AS) in Shantou area and improve the diagnostic level and therapeutic effect. METHODS: Clinical and laboratory data, and the methods and effects of therapy were analyzed. Some patients were followed up. RESULTS: 94% of the cases had an insidious onset. Low back pain or discomfort, peripheral arthritis, positive "4" test and pressing tenderness over the sacroiliac joints and lumbar spine were the frequent symptoms and signs. The degree of sacroiliitis and involvement of hip and spine were related to the disease duration. However, hip joint involvement in juvenile onset AS did not relate to the disease duration. Some cases with disease duration as long as 16 years still remained at II of degree sacroiliitis. Clinical improvement was more obvious in the first two years of treatment. Although some patients came to a standstill condition after this period, yet the disease activity might still relapse with withdrawal of the treatment. The rate of adhering to the treatment for 1, 2, and over 5 years was 34.6%, 28.4%, and 10.3% respectively. The radiological changes frequently did not parallel with the clinical manifestations. CONCLUSION: Early diagnosis is of importance in improving the prognosis of AS and adherence to slow-acting anti-rheumatic drug therapy is beneficial in disease controlling. A follow up of more than 3 years is necessary to estimate the therapeutic efficacy, and the radiological change is the key indicator. AS is a heterogenic disease and the risk factors for prognosis should be further studied.

Adolescent↗
PubMed1999

[The etiology of impotence in 327 diabetic male adults].

OBJECTIVE: To investigate the etiology of impotence in diabetic male adults. METHODS: 327 diabetic men aged 20 - 70 years were interviewed; 129 (39.6%) of them complained of impotence. All the 129 patients were initially evaluated by diabetologists and then underwent psychosexual assessment by psychiatrists. In addition, evaluation for retinopathy, neuropathy, vascular disease and sex hormone level was carried out. RESULTS: The 327 diabetic patients were divided into four age ranges 25 - 34, 35 - 44, 45 - 54, and 55 - 70. The frequency of diabetic impotence in these groups was 9.7%, 34.2%, 48.0%, 62.7% respectively. Neuropathy was found in 79 (61.2%), psychogenic factor contributed in 66 (51.2%), vascular factor was present in 31 (24.0%), leakage of penile venous cavernosa occurred in 5 (3.9%), and treatment with impotence- related medications was the contributing factor in 2 (1.6%). There are significant differences of glycosylated hemoglobin, peripheral neuropathy, autonomic neuropathy, and proliferative retinopathy between impotent and potent diabetic patients. The degree of psychological problem is more serious in the diabetic impotent patients than in potent patients according to Minnesota multiphasic personality inventory (MMPI) test. No significant difference was found in smoking, alcohol and plasma testosterone level. CONCLUSION: The etiology of diabetic impotence is multifactorial. Neuropathy is the main cause, but vascular and psychological factors also contribute to it significantly.

Adult↗
PubMed1999

[Direct intramuscular injection of pSV-VEGF(165) augments capillaries formation in a rabbit model of hindlimb ischemia].

OBJECTIVE: To investigate an easier and safer clinical method of gene therapy for treating arterial ischemic diseases in the lower extremity. METHODS: Recombinant plasmid pSV-VEGF(165) constructed in vitro was directly injected into the ischemic hindlimb muscles in rabbit models. 30 days after gene transfer, the capillary density and the capillary to muscle fiber ratio were determined histochemically in the resected samples. RESULTS: The capillary density and the capillary to muscle fiber ratio were significantly higher for pSV-VEGF(165) transfected group than for control group, particularly increased in the shank of the hindlimbs. CONCLUSIONS: Direct intramuscular injection of pSV-VEGF(165) was an easier and efficient gene therapy method, and it significantly augmented the capillary formation in ischemic limbs.

Animals↗
PubMed1999

[Correlation between gene expression of CCK-A receptor and gallbladder emptying in gallstone patients].

OBJECTIVE: To investigate the expression of CCK-A receptor and its relation with gallbladder hypomotility in patients with gallstone. METHODS: 20 patients with gallstone and 10 normal subjects were studied and gallbladder emptying function was measured by B ultrasonography. The other 8 patients without gallstone who died of accident were selected as controls for measuring mRNA expression of CCK-A receptor of gallbladder; RT-PCR was used to explore gene expression of CCK-A receptor of gallbladder. RESULTS: The gallbladder motility was significantly impaired in gallstone patients. The patients had lower mRNA expression of CCK-A receptor than control subjects (0.633 +/- 0.167 vs. 0.944 +/- 0.230, P < 0.01), and so did patients with impaired gallbladder motility then those with normal motility (0.544 +/- 0.124 vs. 0.768 +/- 0.131, P < 0.05). Furthermore, the change of expression of CCK-A receptors was markedly correlated with gallbladder emptying (r = 0.925, P < 0.01). CONCLUSIONS: mRNA expression of CCK-A receptor in gallstone patients decreases, which was related to gallbladder hypomotility. The down-regulation of gene expression of CCK-A receptor plays an important role in gallbladder hypomotility in patients with gallstone.

Cholecystolithiasis↗
PubMed1999

[Retroviral-mediated transfer of a hygromycin phosphotransferase-thymidine kinase fusion gene into human bladder carcinoma cell].

OBJECTIVE: To evaluate the therapeutic efficacy of retroviral-mediated hygromycin phosphotransferase-thymidine kinase fusion gene (HyTK)/GCV on human bladder carcinoma cell. METHODS: A retroviral expression vector pL (HyTK) SN was constructed. By using FuGENE 6-mediated transfection and "ping-pong effect" technique, high-titer of retroviral supernatant was obtained and HyTK gene was transferred into EJ cells. A retroviral vector encoding, enhanced green fluorescent protein, EGFP was used to rapidly detect the transduction efficiency. Antitumor effects were observed after GCV treatment. RESULTS: In vitro experiments demonstrated the EJ cells transferred by HyTK gene were killed in the GCV treatment. Non-transduced parental cells were not sensitive to GCV, but they were dead by the bystander killing of neighboring cells when mixed with EJ/HyTK cells at various ratios. In addition, this not only affect wild-type EJ cells but also cells from different bladder carcinoma cell lines. CONCLUSIONS: Retroviral-mediated HyTK/GCV systems were a promising suicide gene therapy for bladder carcinoma. EGFP may act as a convenient and rapid reporter to monitor retroviral-mediated gene transfer and expression in bladder carcinoma cells.

Antiviral Agents↗
PubMed1999

[Atypical pheochromocytoma].

OBJECTIVE: To improve the diagnosis and treatment of atypical pheochromocytoma. METHODS: 51 cases of pheochromocytoma were treated from July 1985 to August 1998. RESULTS: Of the 51 cases, 19 were atypical, and were characterized by silent tumor, pheochromocytoma in pregnancy, bilateral tumor, extraadrenal tumor, malignant tumor, and recurrent tumor. Open operation was performed for all kinds of cases in accordance with their special characteristics. CONCLUSIONS: Surgical extirpation is the only means for the treatment of atypical pheochromocytoma and meticulous perioperative management is essential.

Adrenal Gland Neoplasms↗
PubMed1999

[Gene expression of TGF-beta1 and its type II receptor in hepatocellular carcinoma].

OBJECTIVE: To investigate the gene expression of transforming growth factor-beta1 (TGF-beta(1)) and its type II receptor (TGF-beta R II) in hepatocellular carcinoma. METHODS: The expression of TGF-beta(1) and TGF-beta R II at mRNA level and protein level in 30 cases of HCC was separately detected using reverse transcription-PCR and immunohistochemistry technique. RESULTS: There was no difference in the expression of TGF-beta(1) at mRNA level between HCC tissue (24/30) and surrounding liver tissue (26/30). At the protein level, however, the expression of TGF-beta(1) decreased in HCC tissue compared with that in the surrounding liver tissue (P < 0.01). The expression of TGF-beta R II mRNA decreased significantly in HCC tissue (11/30) compared with that in the surrounding liver tissue (23/30) (P < 0.01). The less HCC expressed TGF-beta R II mRNA, the poorer the tumoral hepatocytes differentiated (P < 0.01) and the more likely the portal vein metastasis and cancer embolus appeared (P < 0.05). CONCLUSIONS: In the negative growth regulation of tumoral hepatocytes by TGF-beta(1), two defects take place: the expression of TGF-beta(1) at the protein level and the expression of TGF-beta R II at the mRNA level.

Adult↗