Biomedical subjects

Li Wang

Publications and source records attributed to Li Wang.

At least 163 records · Page 9Linked to original sources

PubMed2006

[Clinical studies on level of N-terminal portion of brain natriuretic in the treatment and prognosis of Chinese patients with chronic left heart failure].

OBJECTIVE: To study the relationship of the level of N-terminal portion of brain natriuretic (NT-ProBNP) with the treatment and prognosis of patients with acute attack of chronic left heart failure. METHODS: Patients (age range 18-80 years) with decompensated heart failure treated in the emergency department in Fuwai Hospital were included in this study. Dynamic changes of plasma levels of NT-ProBNP, angiotensin (AO), renin activity (PRA), angiotensin II (AT II) and aldosterone (ALD) were detected by enzyme linked immunoadsorbent assay (ELISA) before anti-cardiac failure treatment and 3-5, 5-7 days after the treatment. All enrolled patients were followed up for 2 years after leaving hospital, and cardiovascular events such as death, myocardial infarction, worsening of heart failure, severe arrhythmia or delayed discharge from hospital were recorded. RESULTS: Compared with baseline level at admission, plasma NT-ProBNP levels were lowered on 3rd -5th day and 5th-7th day after admission and treatment (both P<0.05) in 44 patients with chronic left heart failure, but there was no difference in NT-ProBNP levels between the 3rd-5th and 5th -7th day after treatment. The levels of plasma NT-ProBNP increased much higher at all observation times in patients with cardiovascular events than without the events (all P<0.05), but the changes in AO, PRA, ATII and ALD showed no significant difference between two groups (all P>0.05). CONCLUSION: During acute onset, plasma NT-ProBNP levels in patients with chronic left heart failure can be lowered at 3-7 days after admission and treatment. Higher baseline levels of plasma NT-ProBNP may have certain predictive values for long term prognosis in patients with chronic left heart failure.

Adolescent↗

PubMed2006

[Advances in researches on genetic epidemiology of pancreatic cancer].

Pancreatic cancer is an extremely life-threatening neoplasm with a case-fatality rate approaching 100%. Smoking is the major known risk factor for this cancer, explaining 19% of all cases. The nutrition and food consumption patterns play other important roles in the etiology of pancreatic cancer, explaining 35% of all cases. Epidemiological evidences on the relationship between nutrition and pancreatic cancer found consistently positive associations between the intakes of meat, carbohydrates, and dietary cholesterol and pancreatic cancer. Consistent inverse relationships with fruit and vegetable intakes and, in particular, with fiber and vitamin C, have also been noted. Many inherited germline mutations increase the risk of pancreatic cancer. In addition, several common polymorphisms in genes that associated with metabolism of environmental carcinogens, DNA repair and folate metabolism may alter the risk of pancreatic cancer. Interaction between genes and environmental factors may contribute to the risk of pancreatic cancer.

Diet↗

PubMed2006

[Study on the relations between genetic polymorphisms in methylenetetrahydrofolate reductase, methionine synthase and the risk of pancreatic cancer].

OBJECTIVE: To determine whether genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MS A2756G) were associated with the risks of pancreatic cancer. METHODS: A hospital-based, case-control study consisting of 101 incident pancreatic cancer cases and 337 controls matched on age, sex and race was conducted to investigate the association between polymorphism in MTHFR and MS, and susceptibility to pancreatic cancer. Genotypes of MTHFR C677T, A1298C and MS A2756G were analyzed by polymerase chain reasction-restriction fragment length polymorphism methods. RESULTS: It was found that multivariate-adjusted odds ratio (ORs; 95% confidence interval) for MTHFR-677CT and 677TT compared with 677CC were 2.17 (1.26 - 3.85) and 3.53 (1.85 - 6.84) respectively, which was in a manner of allele-dose relationship. However, no significant association between the A1298C genotype alone and the risk of cancer was observed which seemed that this polymorphism had a combined effect with the C677T polymorphism. A significant gene-environment interaction was observed between C677T polymorphism and cigarette smoking or alcohol intake. Subjects with variant genotypes who smoked > 17 pack-years had highest risk for developing the cancer, with the OR of 5.58 (2.53 - 12.30). Similarly, the OR (3.27, 1.51 - 7.23) for subjects with variant genotypes of alcohol drinker was significantly higher than that for subjects either having the variant genotype or being drinkers. No association was found between MS A2756G polymorphism and risk of pancreatic cancer in the study. CONCLUSION: These findings supported the hypothesis that genetic polymorphisms in MTHFR C677T might contribute to the risk of developing pancreatic cancer.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed2006

[Rapid detection of toxic substances in water with ToxY-PAM].

A new type of dual-channel PAM fluorometer (ToxY-PAM) was developed for highly sensitive detection of toxic substances in water samples. In conjunction with suspension of unicellular algae as the biotest material, the ToxY-PAM provided a highly rapid and sensitive bioassay test system for the detection of toxic substances in water samples, which could directly or indirectly produce the inhibition of photosynthetic activity in algae. The development process of the detection of toxic substances in water with fluorescence technique, the basic principle and operation of the ToxY-PAM were reviewed in this paper.

Biosensing Techniques↗

PubMed2006

[Evaluation of diffuse lamellar keratitis after LASIK with confocal microscopy].

OBJECTIVE: To investigate the clinical pathologic characteristics and the pathogenesis of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK). METHODS: On 30 patients with 39 eyes being diagnosed with DLK (grade I-grade IV) after LASIK, slit-lamp examinations were performed 1, 3, 5, 7 and 30 days postoperatively, and scanning slit confocal microscope in vivo were performed 3, 7 and 30 days postoperatively. RESULTS: Typical characteristics of grade I and grade II DLK by confocal microscope examination showed up at 3 days postoperatively. We found that the epithelium, the posterior stroma and the endothelium were normal. In the lamella in front of the incision, many round or oval-shaped cells with diameter of approximately 12 approximately 20 microm were detected. These cells had eccentric, highly reflective nuclei and less reflective intracellular structures. They were most likely to be mononuclear cells. These cells distributed diffusely or arranged in line shape. In the lamella, clusters and lines of small, highly reflective, irregular shaped cells 8 to 10 microm in diameter were seen. They were similar to granulocytes or lymphocytes. Seven days postoperatively, these cells almost disappeared. Grade III DLK appeared from 3 to 5 days postoperatively, with more dense infiltration and more highly reflective irregular shape materials in the lamella. Grade IV DLK appeared 5 to 7 days postoperatively. Anterior stroma structure became unclear, with highly reflective and folded corneal flap. Numerous highly reflective scarring formed late. CONCLUSIONS: DLK after LASIK is a inflammatory response in corneal lamella, its typical pathologic characteristic is inflammatory cells infiltration in the lamella. Several factors work together to cause DLK through endogenous and exogenous mechanisms.

Cornea↗

PubMed2006

[Correlations of CpG island methylator phenotype and OPCML gene methylation to carcinogenesis of hepatocellular carcinoma].

BACKGROUND & OBJECTIVE: CpG island methylator phenotype (CIMP) is cancer-specific and involves in the promoter hypermethylation of multiple genes. It is correlated to the genesis or prognosis of various tumors, but it has rarely been reported in hepatocellular carcinoma (HCC). OPCML (opioid-binding protein/cell adhesion molecule-like) gene has been studied mainly in epithelial ovarian cancer, and is thought to be a candidate tumor suppressor gene in epithelial ovarian cancer. This study was to explore the correlations of CIMP and OPCML gene expression to the carcinogenesis of HCC. METHODS: The methylation status of OPCML, p15, SOCS-1, GST-p, RAR-b, p16, p73, p14, MGMT, hMLH1 in 50 specimens of HCC and pericancer tissues was detected using methylation-specific polymerase chain reaction (MSP). RESULTS: The hypermethylation rates of genes were higher in HCC than in pericancer tissues [OPCML (70.0% vs. 64.6%), p15 (58.0% vs. 50.0%), SOCS-1 (78.0% vs. 50.0%), GST-p (56.0% vs. 27.1%), RAR-b (30.0% vs. 6.3%), p16 (26.0% vs. 14.6%), p73 (16.0% vs. 0%), p14 (36.0 vs. 27.1%), MGMT (16.0% vs. 10.4%), and hMLH1 (18.0% vs. 4.2%)]. The methylation rates of SOCS-1, GST-p, RAR-b, p16 and p73 were significantly higher in HCC than in adjacent non-neoplastic tissues (P<0.05). The recurrence occurred earlier in CIMP-positive group (> or =3 methylated genes) than in CIMP-negative group (<3 methylated genes)(P<0.05). The 1-year disease-freely survival rate was significantly lower in CIMP-positive group than in CIMP-negative group (18.2% vs. 75.0%, P<0.05). CONCLUSIONS: CIMP exists in HCC, and may be a prognostic factor of HCC. Promoter methylation of OPCML gene may play an important role in hepatocarcinogenesis.

Adult↗

PubMed2006

[Clinicopathologic study of metaplastic thymoma].

OBJECTIVE: To study the clinicopathologic characteristics of metaplastic thymoma. METHODS: Resection specimens of 3 cases of metaplastic thymoma were studied by light microscopy, immunohistochemistry and electron microscopy. RESULTS: All the 3 patients were females and aged 33, 58 and 45 years respectively. Histologically, a biphasic growth pattern, consisting of intimate admixture of epithelial cells and spindle cells, was noted. The epithelial cells showed mild cytologic atypia, sometimes nuclear grooves and pseudonuclear cytoplasmic inclusions. These cells were arranged in nests and anastomosing cords. Mitotic figures were rarely seen. On the other hand, the spindle cells were bland-looking, mitotically inactive and arranged in fascicles. Immunohistochemical study showed that the epithelial cells strongly expressed cytokeratin (AE1/AE3) but not vimentin or CD5. The proliferation index, as demonstrated by Ki-67 immunostaining, was about 3% to 5%. In contrast, the spindle cells were diffusely positive for vimentin and epithelial membrane antigen. Staining for CD5 and CD20 was negative. The background lymphocytes were positive for CD3, but not for TdT and CD99. Ultrastructurally, well-formed desmosomes or hemidesmosomes were identified in the epithelial element. They were not detected within the spindle cells. CONCLUSION: Metaplastic thymoma is a rarely encountered indolent or low-grade thymic tumor and may represent a distinct clinicopathologic entity.

Adult↗

PubMed2006

[Determination of water-soluble glucose, fructose and sucrose in flue-cured tobacco by high performance anion exchange chromatography coupled with pulsed amperometric detection].

The quantitative determination of water-soluble sugars such as glucose, fructose and sucrose in flue-cured tobacco by high performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) was developed. The method was used to determine flue-cured tobacco samples containing large amounts of carbohydrates after pretreatment by water-leaching and membrane filtration. The separation was performed on a Dionex CarboPac PA-1 anion exchange column with 0.2 mol/L NaOH solution as the eluent at a flow rate of 1.0 mL/min. The injection volume was 20 microL. Good linearities were obtained for glucose, fructose and sucrose within the range of 0.5-100 mg/L (r2 > 0.997). The detection limits (S/N = 3) were 0.1 mg/L, 0.1 mg/L and 0.2 mg/L, and the average recoveries were 97.3%, 101.4% and 98.9% with good reproducibility for glucose, fructose and sucrose, respectively.

English Abstract↗

PubMed2006

[Investigation of CXCR4 in oral squamous cell carcinoma and its influence on proliferation of tumor cells in vitro].

OBJECTIVE: To evaluate the expression of CXCR4 in oral squamous cell carcinoma (OSCC) and its influence on the proliferation of OSCC cells. METHODS: The expression of CXCR4 was evaluated by immunohistochemical study in 91 surgically resected oral squamous cell carcinoma, and the relation between the staining and clinicopathological features was examined. Flow cytometry was used to detect CXCR4 expression in oral squamous cell carcinoma cell line. MTT assay was used to evaluate the SDF-1/CXCR4 influence on proliferation of tumor cells. RESULTS: The expression of CXCR4 in OSCC was 62.6% and there was a significant association between the expression of CXCR4 and lymph node metastases (P < 0.05), tumor size (P < 0.01) and tumor histology grade (P < 0.01). In flow cytometry, a significant shift in fluorescent staining was seen in cells. In MTT assay, recombinant SDF-1 stimulated proliferation of OSCC cell and CXCR4 neutralization by monoclonal antibodies decreased proliferation. CONCLUSIONS: The expression of CXCR4 was significantly correlated with the clinicopathological features and tumor proliferation. CXCR4 might be a valuable biomarker to predict the progression of OSCC.

Adult↗

PubMed2006

[Initial research for effects of vasoactive intestinal polypeptide (VIP) on differentiation of human umbilical cord blood derived CD34+ cells into hepatic related cells].

OBJECTIVE: To investigate the effect of vasoactive intestinal polypeptide (VIP) on differentiation of hematopoietic stem cells (HSC) into hepatic related cells and probe into the possibility that VIP affects HSC transdifferentiation. METHODS: Mini MACS assay was used to purify human CD34+ cells from mononuclear cell (MNC), the purity of the CD34+ cells was evaluated by flow cytometry. Alpha fetal proteins(AFP) in cultured CD34+ cells and their supernatant were measured with ELISA assay. Liver tissue markers on CD34+ cells, AFP, albumin (ALB) and CK-19, were measured by immunohistochemistry. Western blot assay was used to detect the expression of ALB on CD34+ cells. Nest RT-PCR was used to measure the expression of AFP mRNA and ALB mRNA on CD34+ cells, the product of ALB was chosen to measure the sequence. RESULTS: Immunohistochemistry showed that human CD34+ cell contained AFP and albumin but no CK-19 protein. When human CD34+ cells were cultured with VIP for 14 days, the concentration of AFP within CD34+ cells was decreased from (270.00 +/- 11.37) pg/mL to (165.00 +/- 8.51) pg/mL (P < 0.05). Western blot revealed that albumin in CD34+ cells treated with VIP faded, compared to that of control. Both human cord blood MNC and CD34+ cells expressed AFP mRNA and albumin mRNA; the sequence of the product of nest RT-PCR for albumin matched completely with the sequence of albumin in GenBank. CONCLUSION: Human cord blood CD34+ cells have been note to express hepatocyte related markers such as AFP and albumin, although there is no evidence of CK-19 expression. These findings suggests the possibility that human HSC could be transdifferentiated into hepatocyte. The expressions of AFP and albumin on human CD34+ cells depressed by VIP indicate that VIP might inhibit the transdifferentiation of HSC.

Albumins↗

PubMed2006

[Degradation of endocrine disruptor atrazine in drinking water by UV radiation].

The degradation of atrazine with low concentration in drinking water by UV radiation was studied. The main influencing factors and degradation mechanism of this technology were discussed. Experimental results show that the photolytic degradation of atrazine by UV radiation alone is very efficient. Under 205 microW/cm2 irradiation intensity, atrazine removal ratio is 92.38% after 120 minutes. The rate of photodecomposition in aqueous solution follows first-order kinetics. The removal ratio of atrazine can be greatly enhanced by increasing the intensity of UV radiation. The initial concentration of atrazine has no effect on the oxidation reaction. The organic matter and various ion in tap water will decrease the degradation rate. The primary degradation pathway is dechlorination. The reaction rate is high. The hydroxylated compound is the major intermediate product. Hydroyatrazine can be further decomposed by UV radiation and form dealkylated derivatives. But the rate of dealkylated reaction is very low. There is intimate relationship between the change of pH in the solution and the formation of intermediate products.

Atrazine↗

PubMed2006

[Roles of bile and gastrin in the pathogenesis of childhood gastroesophageal reflux disease].

OBJECTIVE: To explore the incidence of acid and bile reflux in children with gastroesophageal reflux disease (GERD) and to study the roles of bile and gastrin in the pathogenesis of childhood GERD. METHODS: Forty-two cases of GERD were divided into two groups according to endoscopic findings: reflux esophagitis (RE) and non-erosive reflux disease (NERD). The patients underwent 24-hr ambulatory esophageal pH and bilirubin monitoring. The serum concentration of gastrin was detected by radioimmunoassay. Thirteen children without gastroesophageal reflux symptoms, digestive tract disease and severe systemic organic disease served as the Control group. RESULTS: Of the 42 cases of GERD, 24 cases were confirmed with RE, with esophageal mucosal lesions, and 18 were NERD without esophageal mucosal lesions by endoscopy. Both acid and bile reflux parameters, including the percentage of total time with pH < 4 and bilirubin absorbance >/= 0.14, the total number of reflux episodes and the number of bile reflux episodes lasting longer than 5 minutes, were significantly higher in the GERD patients than those in the Control group (P < 0.05). The time of esophageal acid exposure (pH < 4) and the percentage of total time with bilirubin absorbance >/= 0.14 increased significantly in the RE group compared with in the NERD group (P < 0.05). Sixteen RE patients had a mixed reflux of bile and acid (66.7%) but only 6 NERD patients (33.3%) had (P < 0.01). The serum concentration of gastrin in the RE group (125.12 +/- 45.06 pg/mL) and the NERD group (98.22 +/- 27.92 pg/mL) was significantly higher than that of the Control group (74.22 +/- 20.34 pg/mL) (P < 0.01, P < 0.05 respectively). A significant difference was noted in the serum concentration of gastrin between the RE and the NERD groups (P < 0.05). CONCLUSIONS: Mixed reflux of bile and acid are common in children with GERD. Bile reflux may play a role in the development of GERD. Gastrin parasecretion may participate in the development of GERD. Gastrin and bile reflux may have synergistic effects on the development of childhood GERD.

Adolescent↗

PubMed2006

[Reflux of bile induces esophageal mucosal inflammation and apoptosis in rats].

OBJECTIVE: To investigate the esophageal mucosal inflammation and apoptosis induced by reflux of different duodenal or bile in rats. METHODS: Esophagus division in esophagogastric junction and then esophagoduodenostomy were performed on rats to make the models of duodenogastroesophageal reflux (DGER). Three kinds of reflux model, DGER (Group A), duodenoesophageal reflux without gastric juice (Group B) and DGER without bile (Group C) were made by adjusting the DGER models. 9 weeks after operation, the esophageal mucosal inflammation was examined under microscope, and the esophageal apoptosis was tested by DNA fragmentation in situ using TdT-mediated dUTP biotin nick end labling (TUNEL). Immunohistochemical method was used to detect the status of esophageal Fas protein (CD95) associated apoptosis. RESULTS: Evidences of reflux esophagitis were seen in all rats with different reflux models. Esophageal inflammation was most severe in group A, then in group B, and the slightest in group C. Barrett's esophagus was seen in group A and group B but not in group C, and the incidence was found to be of no difference between the A and B groups (P > 0.05). Esophageal mucosal apoptosis index in group A was (7.05 +/- 1.44)%, being significantly higher than that in group B (5.25 +/- 1.78)% and group C (2.84 +/- 1.36)%, (P < 0.01). The apoptosis index was significantly higher in group B than in group C (P < 0.01). Fas protein was negative in normal tissues and in all injured esophageal mucosal tissues. CONCLUSION: The DGER without bile inflicts the slighest injury on the esophageal mucosa. Bile may play a significant role in the induction of Barrett's esophagus. The apoptosis indices increase in groups A, B and C, but apoptosis is not correlated with Fas expression.

Animals↗

PubMed2006

[Expression and significance of PTEN/PI3K signal transduction-related proteins in non-small cell lung cancer].

BACKGROUND & OBJECTIVE: PTEN/PI3K signal transduction pathway regulates cell proliferation and survival, and is closely associated with the development and progress of various tumors. However, the relationship between the function of this pathway with lung carcinoma has not been completely elucidated. This study was to investigate the expression and clinical significance of PTEN/PI3K signal transduction-related proteins, such as insulin-like growth factor-1 receptor (IGF-1R), PTEN and phosphatidylinositol 3-kinase (PI3K), in non-small cell lung carcinoma (NSCLC). METHODS: The expression of IGF-1R, PTEN, and PI3K in 59 specimens of primary NSCLC, 19 specimens of metastatic lymph nodes, 16 specimens of para-cancerous hyperplastic lung tissues, and 7 specimens of normal lung tissues were detected by SP immunohistochemistry. The difference of positive rates of IGF-1R,PTEN and PI3K was evaluated by Chi-square test and Fisher's exact test. RESULTS: The positive rates of IGF-1R, PTEN, and PI3K in NSCLC were 72.88%, 27.12%, and 84.75%, respectively. The positive rates of IGF-1R and PI3K were not associated with the clinicopathologic features of NSCLC (P>0.05). The positive rate of PTEN was highly associated with lymph node metastasis of NSCLC (P=0.009), but was not associated with pathologic type and differentiation grade of NSCLC (P>0.05). The positive rate of PTEN was significantly lower and that of PI3K was significantly higher in NSCLC and metastatic lymph node tissues than in para-cancerous hyperplastic and normal lung tissues (P<0.05). The expression of IGF-1R in NSCLC was positively correlated to that of PI3K (r=0.432, P=0.001); while the expression of PTEN was negatively correlated to that of PI3K (r=0.505, P<0.001). CONCLUSION: Overexpression of IGF-1R and PI3K, and low expression of PTEN are closely correlated to the development, invasion and metastasis of NSCLC.

Adult↗

PubMed2006

[Mutations of tumor suppressor gene PTEN mutations in hepatocellular carcinoma and its implications in tumor proliferation and apoptosis].

OBJECTIVE: To study mutations of tumor suppressor gene PTEN in human hepatocellular carcinomas and its effects on the proliferation and apoptosis of hepatocellular carcinoma cell line HHCC. METHODS: (1) PCR-SSCP and sequence analysis were used to detect the mutations of the 5th and 8th exon of PTEN in 42 cases of human primary hepatocellular carcinoma. (2) Eukaryotic expression vectors of the wild-type (pEGFP-wt-PTEN) and the mutant type (pEGFP-PTEN, G129R) of PTEN were constructed. Lipofectamine 2000 mediated gene transfection was used to transfect hepatocellular carcinoma cell line HHCC, in which the PTEN protein is not expressed. Culture medium containing G418 was used to select stable transfectants. MTT colorimetry was used to analyze the proliferation ability of selected cell lines. Naive HHCC cells and HHCC cells transfected with empty vector (pEGFP-C1) served as controls. (3) TNF-alpha was used to induce apoptosis of selected cell clones. RESULTS: (1) Point mutation involving the 5th exon of PTEN was detected in 4 of 42 primary hepatocellular carcinomas. (2) Compared with the control groups, the proliferation of hepatocellular carcinoma cells was significantly inhibited by the transfection of wild-type PTEN gene, while the transfection with mutant PTEN construct did not significantly change the proliferation. (3) The apoptosis indices of cells transfected with the wild-type and the mutant PTEN genes were 13.8% and 8.1% respectively. Compared with the control, the apoptosis index of HHCC cell transfected by the wild type PTEN was significantly lower (P < 0.05). There were no significant differences between HHCC cells transfected with mutated PTEN gene and the control (P > 0.05). The expression of internal 473-phosphorylated Akt of HHCC was weak, but was enhanced when the cells treated with TNF-alpha. However, it was down regulated by the wild type PTEN. CONCLUSIONS: (1) First time report that PTEN mutations can be found in 9.5% human primary hepatocellular carcinomas. (2) The expression of the wild-type PTEN can suppress the proliferation of HHCC cells, and such suppression was lost when PTEN gene was mutated. (3) PTEN inhibition of the proliferation and the enhancement of apoptosis of hepatocellular carcinoma cells is likely related to a down-regulation of the TNF-alpha induced activation of protein kinase Akt pathway.

Apoptosis↗

PubMed2006

[Polymorphisms of the DNA repair genes XRCC1 and XPC: relationship to pancreatic cancer risk].

OBJECTIVE: To determine whether genetic polymorphisms in XRCC1 and XPC are associated with risk of pancreatic cancer. METHODS: A case-control study was conducted in 101 incident cases with pancreatic cancer and 337 controls (matched for age, sex and ethnicity) to investigate whether genetic polymorphisms in DNA repair genes XRCC1 (Arg194Trp and Arg399Gln) and XPC (an intronic biallelic poly (AT) insertion/deletion polymorphism, XPC-PAT) were associated with risk of pancreatic cancer. The odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated by unconditional logistic regression models and adjusted for potential confounding factors. RESULTS: There was a small, non-significant decrease in risk for pancreatic cancer in those carrying Gln/Gln genotype at XRCC1 Arg399Gln site (OR 0.64, 95% CI 0.21 - 1.66, P = 0.30) compared with those having Arg/Arg genotypes. And the XRCC1 Arg194Trp polymorphism was not significantly associated with risk of pancreatic cancer. For XPC-PAT polymorphism, 5.0% of cases and 13.4% of controls were homozygous for the variant allele (PAT+/+), resulting in an OR of 0.30 (95% CI 0.10 - 0.76, P = 0.02), which suggested that the PAT +/+ genotype might have protective effect against pancreatic carcinogenesis. CONCLUSIONS: This study suggest that XPC-PAT polymorphisms may contribute to the risk of pancreatic cancer in our study population.

Adult↗

PubMed2006

[Expression of nuclear factor-kappaB, Ki-67 and matrix metalloproteinase-9 in calcifying odontogenic cyst].

OBJECTIVE: To evaluate the expression of nuclear factor-kappaB (NF-kappaB), Ki-67 and matrix metalloproteinase-9 (MMP-9) in calcifying odontogenic cyst (COC), in order to investigate the proliferation and invasion of COC. METHODS: Twenty-six cases of COC were classified into calcifying cystic odontogenic tumor (CCOT), dentinogenic ghost cell tumor (DGCT) and ghost cell odontogenic carcinoma (GCOC) based on the WHO classification of odontogenic tumors in 2005. The specimens of COC and 10 classic ameloblastoma (AB) were examined immunohistochemically to determine the expression of NF-kappaB p65, Ki-67 and MMP-9. RESULTS: NF-kappaB was mainly detected in the cytoplasm of most tumor cells, but was only detected in the nucleus of few tumor cells (rate of nuclear staining < 1%). The expression of Ki-67 was significantly higher in GCOC than in CCOT (P < 0.001), DGCT (P < 0.05) and AB (P < 0.005). MMP-9 was detected both in tumor cells and stromal cells. GCOC showed significantly higher percentage of MMP-9 positive cases in stromal cells than CCOT, DGCT and AB (P < 0.05). CONCLUSIONS: NF-kappaB may minimally affect the progression and invasion of COC. GCOC shows significantly higher proliferative activity and aggressiveness than CCOT and DGCT. MMP-9 in stroma may play a key role in the invasion of GCOC.

Humans↗

PubMed2006

[Experimental study on corneal organ culture preservation and its application].

OBJECTIVE: To develop a optimal method of corneal organ culture preservation, to evaluate the characteristics of organ cultured cornea and to examine the feasibility of application of organ cultured corneas. METHODS: Thirty-six adult New Zealand rabbit corneas were stored in the closed storage system consisting of fetal calf serum and were transferred to a hyperosmosis dextran-containing medium for 48 hours' deswelling for further experiment after storage for 1, 2, 3 and 4 weeks. The measurement of corneal endothelium density and central thickness was performed prior to and after the storage. The morphology and the contamination of preserved cornea, as well as allogenic grafts' conditions within 7 days after corneal transplantation were also observed. The class II MHC antigen immunofluorescence marker was performed for the examination of corneal dendritic cells by confocal microscopy. RESULTS: The corneal organ culture preservation was successfully established. The contamination rate was approximately 8.3%. All of the rabbit corneas stored within 4 weeks remained transparent. There were little folds in peripheral descemet's membrane when the storage time was up to 3 weeks and the whole descemet's membrane folds was seen when the corneas had been preserved for 4 weeks. The density of corneal endothelium decreased when the preservation time was extended. The loss of corneal endothelium preserved up to 4 weeks was 15.7%. Correlation existed between the thickness of center cornea and the preservation time. The average central thickness of the cornea was 0.7 mm after 4 weeks. The light micrographs showed that the endothelium layer still covered the descemet's membrane completely after 4 weeks. The dendritic cells resided in the limbus epithelium and they were lost after stored for 3 weeks. After allogenic corneal transplantation, the grafts retained transparency within 7 days postoperatively, which indicated that there was no primary failure of grafts. CONCLUSION: Corneal organ culture preservation can ensure the normal function of cultured cornea within a certain preservation time and offer some advantages, e.g. the decrease of corneal immunogenicity.

Animals↗