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Biomedical subjects

M Wu

Publications and source records attributed to M Wu.

At least 217 records · Page 12Linked to original sources
PubMed1999

Lack of human papillomavirus types 16 and 18 DNA in esophageal squamous carcinoma cell lines.

OBJECTIVE: To assess the role of human papillomavirus (HPV) in the carcinogenesis of the esophageal carcinomas in a high-incidence geographical area in Northern China. METHODS: The presence of HPV types 16 and 18 DNA in the three esophageal carcinoma cell lines was examined by type-specific polymerase chain reaction (PCR). RESULTS: No HPV type 16 and 18 DNA was found in any of the three esophageal carcinoma cell lines. CONCLUSION: The results suggest that the role of HPV in human esophageal carcinogenesis in a high-incidence geographical area remains to be elucidated.

Adult↗
PubMed1999

[Expression and reversion of drug resistance- and apoptosis-related genes of a DDP-resistant lung adenocarcinoma cell line A549DDP].

OBJECTIVE: To study the expression of drug resistance- and apoptosis-related genes of A549DDP cells as compared to the parental cell line A549, and its reversion by antisense s-oligodeoxynucleotide (S-ODN) of the differentially expressed genes. METHODS: Sense and antisense S-ODN were transferred into A549DDP cells by lipofectin. Expression of genes related to drug resistance and apoptosis was examined by RT-PCR, immunocytochemistry and flow cytometry. Apoptosis was identified by DNA electrophoresis and TUNEL, and cell growth by MTT uptake. RESULTS: The expression of bcl-2 was positive and that of MRP at mRNA and protein levels was increased in A549DDP cells compared to A549 cells. MDR1, c-myc and TOPO II were similarly expressed in the two cell lines. Both cell lines were negative for c-erbB-2 expression. In A549DDP cells, the expression of bcl-2 and MRP was significantly inhibited by respective antisense S-ODN. Antisense S-ODN could also significantly inhibit proliferation of A549DDP cells, and promote cell apoptosis by reducing its resistance to cisplatin. CONCLUSION: Bcl-2 and MRP genes are responsible for the induced resistance of A549DDP cells to cisplatin.

Adenocarcinoma↗
PubMed1999

[Significance of TNM clasification in prognostic evaluation of hepatocelluar carcinoma following surgical resection].

OBJECTIVE: To investigate correlation between TNM classification of HCC and local-regional cancer-free survival time after hepatectomy. METHODS: A retrospective survey was carried out in 1,725 cases with hepatocellular carcinoma (HCC) receiving radical or relatively radical operation from Jan. 1, 1990 through Dec. 31, 1995. The follow-up rate was 84.46%. The factors under consideration were analysed using Cox proportional hazards survival model and Kaplan-Meier estimation. RESULTS: Univariate analysis showed that 13 clinical and pathologic factors, including clinical stage, age, portalvein tumor thrombus, tumor number found before and/or during operation, radical or relatively radical resection, size of tumor, growing pattern, encapsulation of tumor, daughter nodules (including microscopic nodules), vascular invasion, TNM stage, AFP level after hepatectomy and so on, might all influence local-regional cancer-free survival time. Multivariate analysis revealed four significant prognostic factors: tumor number found before operation, tumor size, daughter nodules and vascular invasion. These four factors were encompassed in TNM staging. By Kaplan-Meier estimation, tumor-free survival rate at 0.5, 1, 3, and 5 years was as follows: at stage I 90.7%, 79.1%, 45.8%, 24.6%; at stage II 86.6%, 75.5%, 51.8%, 38.4%; at stage III 62.6%, 41.5%, 20.6%, 15.9; at stage IV a 33.0%, 18.6%, 8.0%, 5.3%; at stage IVb 42.3%, 35.3%. The mean tumor-free survival time of stage I to IVb was 34.36, 38.25, 10.01, 4.06 and 4.26 months, respectively. There was no significant difference in tumor-free survival rate btween stage I and II. CONCLUSION: TNM stage is one of the most significant prognostic factors determining tumor-free survival after HCC resection.

Adolescent↗
PubMed1999

[The effect of preoperative transcatheter hepatic arterial chemoembolization on disease-free survival after hepatectomy for hepatocellular carcinoma].

OBJECTIVE: To analyse the effect of preoperative transcatheter hepatic arterial chemoembolization(TACE) on disease-free survival rate after surgical excision for hepatocellular carcinoma(HCC), in order to evaluate its therapeutic significance. METHODS: The history of 1,457 cases of HCC with long term follow-up who received curative or relatively curative tumor resection was reviewed. Among these patients, 120 received preoperative TACE. Factors of prognostic significance were analysed using Cox proportional hazards survival mode, and the disease-free survival was analysed by Kaplan-Meier estimation. RESULTS: Multivariate analysis revealed that the factors of prognostic significance were number and size of tumor mass and its gross type, number and efficacy of TACE treatment, presence of tumor thrombus, satellite nodules, vascular invasion, and postoperative AFP level. The 5-year disease-free survival rate following surgery of patients who received TACE twice or more was 51.0%, while that of patients who received TACE once and none was 35.5% and 21.4%, respectively. The mean disease-free suvival time in these 3 groups of patients was 66.4, 22.5 and 12.5 months, respectively. For patients whose TACE treatment was effective, the 5-year disease-free survival rate was 56.8%, with a mean disease-free suvival time of 90.1 months. CONCLUSION: Preoperative TACE is so far the most feasible approach to improve disease-free survival of HCC patients.

Adolescent↗
PubMed1999

[Frequent loss of fragile histidine triad gene transcripts in lung cancer].

OBJECTIVE: To investigate the significance of the fragile histidine triad (FHIT) gene in evaluation of early diagnosis and metastasis in lung cancer. METHODS: 47 lung cancer samples and 16 matched metastatic hilar lymph nodes of lung cancer patients were examined for abnormalities of the gene by using RT-PCR and RT-PCR-SSCP. RESULTS: 32 of 47 (68%) lung cancer samples and 15 of 16 metastatic hilar lymph nodes showed loss of FHIT gene transcripts (exon5-9 or exon1-4). RT-PCR-SSCP reveal no variants. CONCLUSIONS: These data indicate that loss of FHIT gene transcript is frequent in lung cancer and may be an early event in lung tumorigenesis and FRA3B may be involved in the development and progression of the lung cancer.

Acid Anhydride Hydrolases↗
PubMed1999

[Management of retrohepatic inferior vena cava injuries in hepatectomy for neoplasm].

OBJECTIVE: To evaluate the management of injured retrohepatic inferior vena cava during hepatectomy for neoplasm. METHODS: Step-by-step hepatic vascular exclusion, finger pressing, finger pinching, and surface-to-surface sewing up were used in the management of injured retrohepatic inferior vena cava in 16 cases of hepatic resection. RESULTS: In all cases, bleeding was stopped immediately after the procedure without any death and rebleeding. All cases survived after 6 - 18 month follow-up. CONCLUSIONS: The methods mentioned above are simple, useful, time-saving, safe and effective.

Adult↗
PubMed1999

[The relationship between tumor necrosis factor and injuries of liver graft and lung after orthotopic liver transplantation in rats].

OBJECTIVE: To study the relationship between tumor necrosis factor alpha (TNFalpha) levels and ischemia-reperfusion injury of liver graft and lung after different cold-storage time during the early stage after orthotopic liver transplantation in rats. METHODS: Orthotopic liver transplantation was performed in SD rats. The survival rates, the pathology of liver graft and lung and the peripheral seral ALT levels were observed and the bile secretion volume and TNFalpha activities of post-hepatic blood were examined at regular intervals. The animals were divided into 3 groups: control, 4 h cold-storage group, and 6 h cold-storage group (4 degrees C Ringer's solution). RESULTS: All the animals in the control and the 4 h group survived over 60 days, and none survived over 3 days in the 6 h group. The bile secretion volumes were larger in the control and the 4 h group than in the 6 h group (P < 0.05), and the ALT levels were lower in the control and 4 h group than in 6 h group (P < 0.05). The TNFalpha activity was not detected in the control but elevated significantly in the 6 h group, peaked, 2 h after the operation, and only slightly elevated in the 4 h group at the same time (P < 0.05). There were significant focal necrosis of liver graft and alveolar edema and leukocyte infiltration in the lungs in the 6 h group but no obvious injuries were observed in the 4 h group and the control. CONCLUSIONS: TNFalpha may contribute to the pathogenesis of ischemia-reperfusion injury of liver graft and pulmonary complications during the early stage after orthotopic liver transplantation. TNFalpha possibly originates from Kupffer cells of liver graft.

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

[IL-12 gene treatment of hepatocellular carcinoma: experimental study].

OBJECTIVE: To investigate the inhibitory effects of retrovirus vector containing IL-12 gene on hepatoma growth in vivo and to explore a new approach of gene therapy to hepatocellular carcinoma (HCC). METHODS: Retrovirus vector containing IL-12 gene was constructed and transfected into packaged cell PA317. Positive PA317 was injected into the rat which suffered from experimental HCC and its anti-tumor effects and immunity changes were recorded. RESULTS: The packaged cell PA317 containing IL-12 gene could inhibit the proliferation of hepatocellular cell line CBRH3. The rats injected at day 1 or 3 can survive permanently, while those injected at day 5 or 7 can survive longer than those not injected. However, tumor generated in rats injected with blank control or package cells containing retroviral vector without IL-12 gene (P < 0.01). CONCLUSIONS: Package cells transfected with retroviral vector containing IL-12 either injected to the hepatoma tissue locally or given splenic exercises anti-hepatoma effects efficiently. The direct intrasplenic injection route is new, safe and effective.

Animals↗
PubMed1999

[Clinical application of expandable metal stent for palliation of malignant biliary obstruction].

OBJECTIVE: To investigated the long-term result of expandable metallic biliary stent implantation and evaluated preliminarily the factors that might impact the therapeutic effectiveness. METHODS: 134 patients with malignant choledochal stenosis were treated with metallic endo-prosthesis (128 transpapillary endoscopically and 6 transhepatic percutaneously). The follow-up results were compared with those of 97 patients with conventional plastic stents during the same period. RESULTS: The success rate was 95.7%, and the procedure related complications were found in 6.4% of patients. The jaundice was eliminated completely in 85.6% patients. During long-term follow-up, the metal stents were shown patent for a mean duration of 300 days, which was significantly longer than 80 days of polyethylene endoprostheses (P < 0.01). The mean survival was 210 days. From classified data assessment, the stent patency in primary bile duct neoplasm group was almost similar to that in metastatic group, but the median survival of the former was slightly longer than that of the latter. There were flow differences in patancy and survival rates between the hilar obstruction group and the middle and low obstruction group. CONCLUSIONS: The median patancy of expandable metal stents was significantly longer than that of conventional plastic prostheses. To get the highest benefit, however, the indication should be strictly selected.

Adult↗
PubMed1999

[The diagnostic value of perforin and granzyme B genes mRNA expression in acute rejection after hamster to rat orthotopic liver transplantation].

OBJECTIVE: To explore the mRNA expression of perforin and granzyme B genes activated by cytotoxic T lymphocytes (CTL) for monitoring early acute rejection after liver transplantation. METHODS: The mRNA expression of perforin and granzyme B genes in grafts after gold hamster to rat liver transplantation was examined by reverse transcriptase polymerase chain reaction. Histological findings were studied comparatively, and isogenic rat liver transplantation was the control. RESULTS: The mRNA expression of perforin and granzyme B genes began to be up-regulated on the day 3 after transplantation, when no histologic evidence of rejection was found. Levels of expression significantly increased after day 4 and persisted through the whole course of rejection. In contrast, the control group showed no expression of mRNA for perforin and granzyme B. CONCLUSIONS: The determination of mRNA expression of perforin and granzyme B genes are useful to early diagnosis of acute rejection of liver transplantation.

Acute Disease↗
PubMed1999

[Surgical treatment of truncus arteriosus in children].

OBJECTIVE: To summarize the surgical results of truncus arteriosus in children. METHODS: Five patients with persistent truncus arteriosus underwent complete repair of truncus arteriosus. Type I was found in 2 patients, type II in 2 and type IV in 1 according to Collett and Edwards. Their ages ranged from 3 to 12 years (mean 6.3 years). The time of pulmonary circulation and evacuation of the pulmonary artery was not significantly prolonged. Complete repair was via a median sternotomy utilizing hypothemia with cardiopulmonary bypass, entailing separation of the pulmonary arteries from the truncus, repair of the resultant defect in the aorta, ventricular septal defect (VSD) closure with a patch in which the interrupted pledget-supported suture was placed in the truncal valve annulus of the superior border of VSD, and restoration of right ventricular outflow tract (RVOT) continuity utilizing extra cardiac conduits, of which autologous pericardial valved dacron conduit was used in 4 patients and homograft conduit in 1. RESULTS: Postoperative mean pulmonary pressure decreased significantly in all patients (P < 0.01) and the pressure gradient across conduit was 7 - 35 mm Hg. Two patients died immediately after the operation, which was not associated with pulmonary vascular lesion. Among 3 survivors, I had low cardiac output and respiratory dysfunction after operation and the others recuperated uneventfully. Survivors were followed up for a period of 114, 96 and 34 months respectively, and were all in NYHA functional class I. One died of occlusion of conduit 8 years after operation. CONCLUSIONS: Children with truncus arteriosus are still indicated for complete correction. Autologous pericardial valved dacron conduit has excellent long-term outcomes. Correcting truncal valve insufficiency, repairing VSD, avoiding large pressure gradient across conduit and shortening CPB time are keys to improve the survival rate of patients and achieve excellent long-term outcome.

Bioprosthesis↗
PubMed1999

Effect of liposome-encapsulated total alkaloid of harmaline on rabbit lens epithelial cells: experimental study on the prevention of posterior capsule opacification.

PURPOSE: To investigate whether liposome encapsulated total alkaloid of Harmaline (TAH) as a therapeutic agent is beneficial to prevention of posterior capsular opacification (PCO). METHODS: Liposome-encapsulated TAH was prepared by modified freeze-thawing method. 0.1 ml of liposome-encapsulated TAH (0.2 mg/ml) was injected into the capsular bag during extracapsular lens extraction (ECLE) of each eye in total 10 rabbit eyes. Blank liposome or balance salt solution (BSS) was used as control. Slit-lamp examination and histopathological examination was used to evaluated capsule opacification. Intraocular pressure (IOP), density and morphology of corneal endothelia cells, the amplitude and latency of b wave of ERG were measured. RESULTS: The inflammatory response was mild both in TAH treated and the control group. PCO formation occurred in the control group 2 weeks postoperatively, but the posterior capsule was clear in TAH treated eyes. 4 weeks and 8 weeks after operation, PCO occurred both in TAH treated and control eyes. However, it was milder in the TAH treated eyes. IOP remained at the normal level in all eyes. There was no difference in the density of corneal endothelial cells, and the amplitude and latency of b wave of ERG between TAH treated and control eyes. Histopathological study revealed that lens epithelial proliferation occurred 4 weeks and the Soemmerings ring developed 8 weeks postoperatively in the control eyes. However, only mild vacuolization and pkynotic changes of lens epithelial cells were found in TAH treated eyes. Transmmission electronic microscopy demonstrated that there were mild cytoplasm vacuolization and mitochondria swelling of lens epithelial cells in TAH treated eyes. CONCLUSION: The results suggest that liposome encapsulated TAH can inhibit metaplasia and proliferation of lens epithelial cells in the rabbit eye without obvious toxicity to the eye tissue. It may be used as a potential agent to prevent the development of PCO.

Alkaloids↗
PubMed1998

Effects of lipophilic ions on outer hair cell membrane capacitance and motility.

The outer hair cell (OHC) from the mammalian organ of Corti possesses a bell-shaped voltage-dependent capacitance function. The nonlinear capacitance reflects the activity of membrane bound voltage sensors associated with membrane motors that control OHC length. We have studied the effects of the lipophilic ions, tetraphenylborate (TPB-) and tetraphenylphosphonium (TPP+), on nonlinear capacitance and motility of isolated guinea-pig OHCs. Effects on supporting cells were also investigated. TPB- produced an increase in the peak capacitance (Cmpk) and shifted the voltage at peak capacitance (VpkCm) to hyperpolarized levels. Washout reversed the effects. Perfusion of 0.4 micrometer TPB- caused an average increase in Cmpk of 16.3 pF and VpkCm shift of 13.6 mV. TPP+, on the other hand, only shifted VpkCm in the positive direction, with no change in Cmpk. The contributions from native OHC and TPB--induced capacitance were dissected by a double Boltzmann fitting paradigm, and by blocking native OHC capacitance. While mechanical response studies indicate little effect of TPB- on the motility of OHCs which were in normal condition or treated with salicylate or gadolinium, the voltage at maximum mechanical gain (VdeltaLmax) was shifted in correspondence with native VpkCm, and both changed in a concentration-dependent manner. Both TPB--induced changes in Cmpk and VpkCm were affected by voltage prepulses and intracellular turgor pressure. TPB- induced a voltage-dependent capacitance in supporting cells whose characteristics were similar to those of the OHC, but no indication of mechanical responses was noted. Our results indicate that OHC mechanical responses are not simply related to quantity of nonspecific nonlinear charge moved within the membrane, but to the effects of motility voltage-sensor charge movement functionally coupled to a mechanical effector.

Animals↗
PubMed1998

MTO1 codes for a mitochondrial protein required for respiration in paromomycin-resistant mutants of Saccharomyces cerevisiae.

Mutations in MTO1 express a respiratory defect only in the context of a mitochondrial genome with a paromomycin-resistance allele. This phenotype is similar to that described previously for mss1 mutants by Decoster, E., Vassal, A., and Faye, G. (1993) J. Mol. Biol. 232, 79-88. We present evidence that Mto1p and Mss1p are mitochondrial proteins and that they form a heterodimer complex. In a paromomycin-resistant background, mss1 and mto1 mutants are inefficient in processing the mitochondrial COX1 transcript for subunit 1 of cytochrome oxidase. The mutants also fail to synthesize subunit 1 and show a pleiotropic absence of cytochromes a, a3, and b. In vivo pulse labeling of an mto1 mutant, however, indicate increased rates of synthesis of other mitochondrial translation products. The respiratory defective phenotype of mto1 and mss1 mutants is not seen in a paromomycin-sensitive genetic background. The visible absorption spectra of such strains indicate a higher ratio of cytochromes b/a and elevated NADH- and succinate-cytochrome c reductase activities. To explain these phenotypic characteristics, we proposed that the Mto1p.Mss1p complex plays a role in optimizing mitochondrial protein synthesis in yeast, possibly by a proofreading mechanism.

Anti-Bacterial Agents↗
PubMed1998

[Loss of heterozygosity microsatellite DNA on chromosome loci 3, 5, 7, 9 and 18 in human pancreatic cancer].

OBJECTIVE: Detecting the loss of heterozygosity in paraffin-embedded pancreatic cancer tissues. METHODS: Analysing loss of heterzygosity (LOH) of microsatellite DNA on chromosome loci 3,5,7,9 and 18 with PCR-SSLP-silver stain method in pancreatic cancer. RESULTS: In 45 sporadic pancreatic cancer samples and their paired control tissue, LOH was detected on site for D18S46( 18q21.1,31.0%), D18S474 (18q21.1, 20.0%), D9S176 (9q22-31,20.0%), D3S1234 (3p14.2,17.5%),D 3S1289 (3p21.1, 15.7%), D3S1481 (3p14.2,4.9%), D7S486 (7q22,3.6%), D5S365 (5q32, 3.2%) and D3S587 (3p24-26, 2.6%). CONCLUSION: Different percentages of loss of heterzygosity on specific chromosomal regions were found, and the meaning of the results was discussed. Some key genes may play a role in the pathogenesis of pancreatic cancer.

Adult↗
PubMed1998

Inhibition of cancer cell growth by all-trans retinoic acid and its analog N-(4-hydroxyphenyl) retinamide: a possible mechanism of action via regulation of retinoid receptors expression.

In order to better understand the mechanisms that underlie the antiproliferative effect of retinoids, we have examined the response of human carcinoma cell lines to all-trans retinoic acid (RA) and N-(4-hydroxyphenyl) retinamide (4HPR) in terms of cell growth, apoptosis and regulation of retinoic acid receptors (RARs) and retinoid X receptors (RXRs) mRNA. GLC82 (lung adenocarcinoma), BGC823 (stomach adenocarcinoma) and EC109 (esophageal squamous carcinoma) cells were treated with 10 microM of RA or 4HPR for various length of time and analyzed. The results show that growth inhibition by RA and 4HPR in GLC82 and BGC823 cells correlates with the induction of RARbeta2 gene, whereas RA resistance in EC109 cells parallels loss of RARbeta2 induction. Exogenous RARbeta2 expression did not restore RA responsiveness in EC109 cells, but potentiated 4HPR-induced growth inhibition, suggesting that 4HPR acts at least in part via the RARbeta receptor. We speculate that the loss of RARbeta2 inducibility in EC109 cells may be due to an unknown repressor.

Adenocarcinoma↗