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Biomedical subjects

X Liu

Publications and source records attributed to X Liu.

At least 865 records · Page 48Linked to original sources
PubMed1999

[The change in bacterial flora and antibiotic resistance of bacteria of burn patients in our hospital during 1986-1996].

OBJECTIVE: In this article we investigated and analyzed the pathogenetic bacteria of burn infection and their drug resistance in recent 5 years from 1991. METHODS: The patients are divided into 2 groups. The 1st group is from June 1986 to May 1991, and the 2nd group is from June 1991 to June 1996. Blood culture and burn wound bacteria culture were done, and bacteria and their drug sensitivity were analyzed. RESULTS: In blood culture, Micrococcus had risen to rank the top (21.6%), while Staphylococcus aureus fell to rank the third. Among these G+ cocci comprised 56.5%, and G- bacilli 30.1%. In burn wound culture, Pseudomonas aeruginosa with rate of 18.1% was still in the 1st place. Enterobacter cloacae was in the 2nd place with the rate of 13.1%. Among these G- bacilli comprised 58.6%, G+ cocci 35.3%. Micrococcus enterobacter cloacae, Pseudomonas maltophilia, fecal Staphylococcus and candida albicans increased remarkably. CONCLUSION: The changes of pathogenetic bacteria of burn infection and bacteria drug resistance have certain relations with the wide usage of broad spectrum antibiotics such as cefazidime and imipenem.

Actinomycetales Infections↗
PubMed1999

[A clinicopathological study of nodular lymphocyte predominance Hodgkin's disease].

OBJECTIVE: To investigate the clinicopathological characteristics of nodular lymphocyte predominance Hodgkin's disease. METHODS: Eleven samples of paraffin embedded lymph node and one of frozen lymph node from nodular lymphocyte predominance Hodgkin's disease patients were studied. HE staining, immunohistochemistry for CD3, CD19, CD20, CD30, CD45RB, kappa and lambda light chain and single L&H cell polymerase chain reaction (PCR) were performed. RESULTS: The diagnosis of nodular lymphocyte predominance Hodgkin's disease was established by the identification of characteristic L&H cells in the nodular small lymphocytes and histiocytes background. L&H cells expressed CD19(10/12), CD20(12/12), CD45RB(12/12) and kappa light chain (11/12). IgH and V kappa 4 family gene rearrangements were detected in the single L&H cell. Eight of the patients survived more than 5 years. CONCLUSION: Nodular lymphocyte predominance Hodgkin's disease has a very slow disease course and a better prognosis. It is a malignant lymphoma derived from B cells.

Adolescent↗
PubMed1999

Is endothelin-1 an aggravating factor in the development of acute pancreatitis?

OBJECTIVE: We have reported previously that cerulein-induced edematous pancreatitis would transform into hemorrhagic pancreatitis by administration of endothelin-1 in rats. In the present study, we tried to protect rat model from developing into hemorrhagic pancreatitis with BQ123 (an ETA receptor antagonist). METHODS: The rat model was made by 5-hour restraint water-immersion stress and two intraperitoneal injections of cerulein (40 micrograms/kg) at hourly interval. BQ123 (3 or 6 mg/kg) was administered intravenously 30 minutes before and 2 hours after the first cerulein injection. RESULTS: Acute hemorrhagic pancreatitis was induced in all rats treated with cerulin + stress. The score for pancreatic hemorrhage was 2.4 +/- 0.2 in this group. In the rats pretreated with BQ123, the score was reduced to 1.0 +/- 0.0, pancreas wet weight and serum amylase activity were significantly reduced, and histologic alterations in the pancreas lightened, also the local pancreatic blood flow improved without affecting the systemic blood pressure. CONCLUSIONS: These results suggest that endothelin-1 should play a role in aggravating the development of acute hemorrhagic pancreatitis, through its action on the pancreatic microcirculation.

Acute Disease↗
PubMed1999

[The role of mitogen-activated protein kinases family in ischemic preconditioning of rat heart].

OBJECTIVE: To investigate the cardioprotective effect of mitogen-activated protein kinases (MAPKs) of ischemic preconditioning (IPC) in rat heart. METHODS: In the model of ischemia/reperfusion (I/R) of isolated perfused SD rat heart, the effect of IPC on I/R injury was observed. The activities of MAPK family members, ERKs, p38 and SAPK, and their relationship with IPC phenomenon were also observed. RESULTS: IPC significantly improved myocardial functions in heart subjected to I/R injury, and attenuated leakage of myocardial creatine kinase and depletion of ATP. IPC activated ERK and p38 kinase. Their activities were increaed by 73% (P < 0.01) and 69% (P < 0.01) respectively. However, IPC showed no effect on myocardial SAPK activity. Preparation with genistein (an inhibitor of tyrosine kinase) and PD098059 (an inhibitor of ERK) abolished IPC cardioprotection, while p38 kinase inhibitor SB202190 had no effect on IPC. CONCLUSIONS: ERKs, but not p38 and SAPK of MAPK, mediates the IPC cardioprotective effect.

Animals↗
PubMed1999

Expression of heat shock protein 90 beta in human gastric cancer tissue and SGC7901/VCR of MDR-type gastric cancer cell line.

OBJECTIVE: To examine the expression of heat shock protein (HSP) 90 beta in human gastric cancer tissue and SGC7901/VCR of MDR-type gastric cancer cell line. METHODS: Immunohistochemical staining and in situ hybridization methods. RESULTS: Heat shock protein 90 beta was mainly located in the cell cytoplasma and weakly expressed in non-cancerous gastric mucosa. The expression rates of HSP90 beta in normal gastric mucosa, gastritis and paracancer tissues were 11.76%, 13.04% and 11.42% respectively, and there were no significant differences between them (P > 0.05). The expression of HSP90 beta was increased in gastric cancer. The positive rate of HSP90 beta in gastric cancer tissue was 30.00%, and was higher than non-cancerous gastric mucosa (P < 0.05). The expression rates of HSP90 beta in well differentiated, moderately differentiated, poorly differentiated gastric cancer and mucinous carcinoma were 15.38%, 31.25%, 33.33%, and 42.85% respectively. The expression of HSP90 beta in SGC7901/VCR of MDR-type gastric cell line was higher than in its parental cell line SGC7901. In situ hybridization showed that the positive signal of HSP90 beta was mainly located in the cell cytoplasma. CONCLUSIONS: The expression of HSP90 beta was higher in gastric cancer tissue than in non-cancerous gastric mucosa. In gastric cancer tissue, the expression of HSP90 beta was greater in poorly differentiated cancer tissue, and in SGC7901/VCR of MDR-type gastric cancer cell line the expression of HSP90 beta was higher than that in its parental cell line SGC7901.

Adenocarcinoma, Mucinous↗
PubMed1999

Cloning and sequencing of the fragment of angiostatin K (1-3) gene.

OBJECTIVE: To secure anti-endotheliocyte hyperplasia functional fragment of human angiostatin K (1-3) gene. METHODS: As the template of leukocytotic cDNA, functional fragment of human angiostatin K (1-3) cDNA was amplified by PCR, cloned into the vector pGEM-3Zf, and sequenced according to Dye primer sequencing kit. RESULTS: The functional fragment of angiostatin K (1-3) cDNA (859 bp) was obtained by PCR and determined by sequencing. CONCLUSION: The angiostatin K (1-3) gene has been cloned. The gene is of great significance in tumor-antiangiogenesis therapy.

Angiogenesis Inhibitors↗
PubMed1999

[The changes of protein kinase C activity in peripheral blood lymphocytes in asthmatic patients].

OBJECTIVE: To investigate changes of protein kinase C (PKC) activities in peripheral blood lymphocytes (PBL) and the relationship between PKC activities and level of the air flow limitation in asthmatic patients. METHODS: PKC from cytosolic and membrane fractions of PBL was isolated and purified, then its activities were determined. RESULTS: (1) The total PKC activities in PBL in asthmatic subjects (n = 18) were significantly increased as compared to those in normal subjects (n = 6, P < 0.01). More over, the membrane PKC activities and their percentages in the total PKC activities were higher in asthmatics than in normals (P < 0.05). In vitro it suggested that methacholine(n = 5) or histamine (n = 5) could significantly increase translocation of PKC from cytosol to membrane (P < 0.05) and, by doing so, activate the PKC in PBL. (2) The total PKC activities were significantly correlated with FEV1% (r = -0.73, P < 0.001, n = 18), PEF(r = -0.62, P < 0.01, n = 18) and V50 (r = -0.63, P < 0.01, n = 18). (3) The total PKC activities in PBL were significantly correlated with the levels of sIL-2R in serum in the asthmatics (r = 0.58, P < 0.05, n = 18). CONCLUSIONS: (1) The total activities and the level of translocation of PKC were significantly increased in PBL in asthmatics as compared to normals. This abnormal activation state of PKC in PBL may be related with the increased levels of inflammatory mediators. (2) Highly significant correlations existed between the total PKC activities and the level of air flow limitation in asthmatics. (3) PKC signal pathway may be implicated in the activation of T-lymphocytes in asthma. It is suggested that the role of PKC signal pathway may be important in the pathogenisis of asthma.

Adult↗
PubMed1999

[Expression and clinical significance of telomerase catalytic subunit gene in lung cancer and its correlations with genes related to drug resistance and apoptosis].

OBJECTIVE: To investigate mRNA expression and prognostic significance of telomerase catalytic subunit (hTRT/hEST2) and its relations to apoptosis, proliferation and drug resistance in patients with lung cancer. METHODS: Telomerase repeat amplification protocol-PCR(TRAP-PCR) and in situ hybridization were used to detect telomerase activity and expression of hTRT/hEST2 mRNA, respectively. The expression of bcl-2, c-myc, MRP, Neu, MDR1 at mRNA and protein levels was measured by means of RT-PCR and immunohistochemisty. In situ end labeling(ISEL) assay was used to evaluate apoptotic cells. RESULTS: hTRT/hEST2 mRNA was detected in 41 of 56 NSCLC(73.2%) and 17 of 20 SCLC(85.0%), but it was not expressed in lung tissues adjacent to the tumor. Telomerase activity was postively correlated with the expression of hTRT/hEST2. In NSCLC, hTRT/hEST2 mRNA was positively correlated with bcl-2(r = 0.7327, P = 0.015), c-myc(r = 0.8263, P = 0.001), MRP(r = 0.3971, P = 0.003) and neu(r = 0.3208, P = 0.017), but not with MDR1 (r = 0.2415, P = 0.672). In SCLC, positive correlation was only found between hTRT/hEST2 and bcl-2 (r = 0.5663, P = 0.024). Correlation was positive between hTRT/hEST2 mRNA and Ki-67 expression but negative between hTRT/hEST2 and apoptosis both in NSCLC and SCLC. Multivariate Cox regression analysis showed that telomerase catalytic subunit hTRT/hEST2 and number of apoptotic cells were of prognostic significance in NSCLC. CONCLUSION: As telomerase catalytic subunit expression shows correlations with MDR- and apoptosis-related genes and is of prognostic significance, telomerase in relation to multiple drug resistance deserves in-depth study.

Adolescent↗
PubMed1999

[Arterial infusion chemotherapy combined with concurrent radiotherapy for local advanced pancreatic cancer].

OBJECTIVE: To analyze the treatment results of un-resectable local pancreatic cancer by arterial infusion chemotherapy plus concurrent radiotherapy or radiotherapy alone. METHODS: A total of 50 patients with local advanced pancreatic cancer from January 1992 through October 1995 were treated either by arterial infusion chemotherapy (C) plus concurrent radiotherapy (R) (22 cases) or by radiotherapy alone (28 cases). Radiation given was the same in the two groups of patients (50-60 Gy in 5 to 6 weeks, 1.8-2 Gy/Fx, 5 Fx/wk). Infusion chemotherapy was performed once every 4 weeks, consisting of 5-fluorouracil 1.0 g, mitomycin C 10 mg, cisplatin 60 mg. An average of 2.3 cycles was given to each patient. RESULTS: Although the remission rate of jaundice and pain did not show significant difference between the two groups, patients in C + R treatment group had longer period of symptomatic remission (P < 0.05). The response rate (CR + PR) was 68.2% in C + R treatment group and 35.7% in R treatment group, respectively. The 1-, 2-, and 3-year survival rate was 75.3%, 36.8%, 25.4% in C + R treatment group, and 51.3%, 22.6%, 8.7% in R treatment group, respectively. CONCLUSION: Arterial infusion chemotherapy combined with concurrent radiotherapy is a treatment of choice for patients with local unresectable cancer of the pancreas.

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

[Microvessel quantitation and expression of VEGF in colorectal tumors].

OBJECTIVE: To evaluate angiogenesis in colorectal tumorigenesis and to assess the prognostic significance of microvessel quantitation and VEGF status. METHODS: Thirty two colorectal carcinomas, 5 adenomas and 10 normal mucosa were studied immunohistochemically for microvessels and expression of VEGF. RESULTS: The mean vascular density (MVD) was 11 +/- 4 in normal mucosa, 28 +/- 11 in adenomas, and 50 +/- 22 in carcinomas (normal versus adenomas P > 0.05; normal versus carcinomas P < 0.01; adenomas versus carcinomas P < 0.05). MVD varied with tumor cell differentiation and tumor stage, but the differences were not significant. The expression of VEGF is closely associated with angiogenesis. Both MVD and VEGF expression were associated with prognosis. CONCLUSION: VEGF status and MVD are of prognostic significance in colorectal cancer patients.

Colorectal Neoplasms↗
PubMed1999

[Short-term effect of navelbine on non-small cell lung cancer in 48 cases].

OBJECTIVE: To evaluate effect of navelbine on non-small cell lung cancer (NSCLC). METHODS: Forty eight cases of cytologically and pathologically confirmed advanced NSCLC were treated with combined chemotherapy including navelbine as the cardinal drug from May, 1995 to January, 1988. They were randomly divided into two groups. One group of 20 cases was treated with NP regimen (NVB + PDD); the other group of 28 cases was treated with NI regimen (NVB + IFO). All patients received no previous treatment. RESULTS: There was no complete response in patients treated with either regimen. Partial response was observed in 8 of 20 NP-treated patients(40.0%) and in 12 of 28 NI-treated patients (42.8%). There was no statistical difference in response rate between these 2 groups of NSCLC patients. However, in both groups of patients, the therapeutic effect was better in adenocarcinoma than in sequamous-cell carcinoma patients. NP regimen seemed effective in the control of bone metastases and pains. Side effects were mainly myelo-suppression and digestive tract reaction. CONCLUSION: Combined chemotherapy including NVB is worthy of use in the treatment of advanced NSCLC especially for those with bone metastasis.

Aged↗
PubMed1999

[Clinical significance of multidrug resistance-associated protein(MRP) gene expression in non-small cell lung cancer].

OBJECTIVE: To investigate expression of multidrug resistance-associated protein (MRP) in non-small cell lung cancer and its relation to histological type, TNM staging and prognosis. METHODS: In situ hybridization was used to examine mRNA expression of MRP. RESULTS: The overall positive rate of MRP expression was 74.1%, with 73.3% and 72.0% in adenocarcinoma and squamous-cell carcinoma, respectively. The expression of MRP was not related to histological subtypes, TNM staging and cell differentiation. In 47 patients who received chemotherapy, 35 patients with positive MRP expression(+(-)++) showed worse prognosis than in those with negative expression (P < 0.05). The median survival time was 8.7 months and 21 months in patients with positive and negative MRP expession, respectively. In patients with squamous-cell carcinoma, the survival rate was significantly lower in patients (n = 12) with positive MRP expression than in those (n = 7) with negative MRP expression (P < 0.05). Their median survival time was 6 months and 19.5 months, respectively (P < 0.05). CONCLUSION: The expression of MRP gene is negatively correlated with survival of patients with squamous-cell carcinoma, but not adenocarcinoma, who received chemotherapy.

Adult↗
PubMed1999

[Type IV collagen and C-erbB-2 expression in oral candidal leukoplakia].

OBJECTIVE: To investigate type IV collagen and C-erbB-2 expression in oral candidal leukoplakia. METHODS: 27 cases of oral candidal leukoplakia were studied by immunohistochemistry. RESULTS: In normal and simple hyperplastic epithelia type IV collagen was noted as brown linear staining along the basement membrane. The most obvious change in the staining pattern was that the linear staining became very thin or discontinued in dysplastic epithelia. C-erbB-2 was demonstrated in 25 cases(78%). The positive staining, as a reticular pattern, was located at cell membrane, and not correlated with epithelial dysplasia. CONCLUSION: The results indicate that type IV collagen expression changed in candidal leukoplakia with epithelial dysplasia. This kind of change may be related to basement membrane destruction. The immunohistochemically expression of C-erbB-2 has no correlation with epithelial dysplasia.

Candidiasis, Oral↗
PubMed1999

[A rat model of tongue mucosa squamous cell carcinoma induced by oral administration of 4NQO in drinking water].

OBJECTIVE: To establish a more realistic animal model for oral carcinogenesis which reveals histological and immunological characteristics similar to the human counterpart. METHODS: 0.002% 4-nitroquinoline 1-oxide (4NQO) in drinking water was administered orally to SD rats for 9-32 weeks. Then the rats were killed and their tongues were removed for histological assessment. RESULTS: Gross changes included leukoplakia, erosion, ulcer and papillary appearance on the dorsum of the posterior tongue were present during carcinogenesis. Their corresponding histopathological findings ranged from hyperplasia (HP), mild-moderate dysplasia (mmDP), severe dysplasia (sDP) and in situ carcinoma (ISC) to well-differentiated invasive squamous cell carcinoma (SCC). The severity of lesions corresponded to the duration of administration. The tongues in rats treated with 4NQO for 9 weeks showed HP (80.0%) and mmDP (20.0%); those for 13 weeks showed mmDP (66.6%) and sDP (33.3%); those for 16 weeks showed sDP (55.5%) and ISC (44.4%); and those for 32 weeks showed sDP (12.5%), ISC (12.5%) and SCC (75.0%). The incidence of tongue cancer in rats treated with 4NQO for 9 weeks, 13 weeks, 16 weeks and then observed for 32 weeks was 50.0%, 62.5%, and 77.8%, respectively. No metastases were found. CONCLUSION: 4NQO reliably produced preneoplastic and neoplastic tongue mucosa lesions, which morphologically and histologically mimic human oral carcinogenesis. The rat tongue, a target organ of 4NQO, is not an immunologically privileged site like the hamster buccal pouch. Thus, the model should be appropriate to study molecular mechanism of neoplastic transformation and to assess new treatment modalities of premalignant and malignant lesions of the human oral cavity.

4-Nitroquinoline-1-oxide↗
PubMed1999

[Experimental study on the effect of restorative dentin formation with human dentin phosphoprotein in immature permanent teeth of minipig].

OBJECTIVE: To investigate the function of human dentin phosphoprotein(DPP) on dentine mineralization in vivo. METHODS: Pulp capping with human DPP was made in the permanent teeth of minipigs with calcium hydroxide and zinc oxide eugenol cement as controls. The minipigs were sacrificed at intervals of 14, 30, 90 days respectively after operation. RESULTS: The histopathological results revealed that pulp cells had developed into odontoblastoid cells around the major restorative dentin body after two weeks. There was complete restorative dentin bridge a month later. The bridge became thick and dense, and mainly was tubular dentin in 3 month. There were well developed odontoblasts under the bridge. In the calcium hydroxide capping group, inflammatory cytonecrosis zone was found in the surface of dental pulp and only a little calcial bodies formed in two weeks. Complete restorative dentin bridge was formed in 1 to 3 months, the speed of dentin bridge formation was not as quick as that of DPP group. CONCLUSION: DPP can induce pulp cells to develop into odontoblasts and formation of dentin bridge with little stimulation to the dental pulp. This study suggests that DPP plays an important role in the biomineralization of dentin development and restoration.

Animals↗
PubMed1999

[Clinical observation on effect of yiqi huoxue decoction in comprehensive treatment on advanced stage of esophageal cancer].

OBJECTIVE: To observe the effect of Yiqi Huoxue (Replenishing Qi and activating blood circulation, YQHX) decoction in patients with advanced stage esophageal cancer treated with radiotherapy (RT) and intervention chemotherapy (ICT). METHODS: In comparing 31 patients who were treated with RT and ICT (Group A), and 31 patients treated with RT and ICT plus YQHX decoction (Group B). RESULTS: Immediate effective rate were 48.4% in Group A and 64.5% in Group B (P > 0.05). The function of bone marrow in Group B was obviously higher than that in Group A. The 1 year metastasis rate in Group A was higher than that in Group B, but the long-term survival rate of Group B was obviously higher than that in Group A (P < 0.05). CONCLUSION: YQHX decoction could reduce the inhibition of bone marrow caused by radiotherapy and intervention chemotherapy, lower the metastasis rate, prolong the long-term survival rate and improve the quality of life.

Adult↗