Biomedical subjects

Bo Yu

Publications and source records attributed to Bo Yu.

At least 73 records · Page 4Linked to original sources

PubMed2003

p73 Overexpression and angiogenesis in human colorectal carcinoma.

BACKGROUND: Solid tumors requires neovascularization for growth and metastasis. Angiogenesis depends on the local balance between positive and negative effectors, the production of which can be regulated by oncogenes and tumor suppressor genes. The aim of this study was to investigate expression of p73, a gene homologous to the tumor suppressor gene p53, in colorectal cancer and its relationship to angiogenesis. METHODS: p73 expression was examined by immunohistochemistry and western blot analysis on 56 primary colon carcinomas with matched normal mucosas. Vascular endothelial growth factor (VEGF) and microvessels were highlighted using a monoclonal antibody specific to VEGF and von Willebrand factor (vWF). RESULTS: The immunoexpressions of p73 were significantly higher in the primary colorectal carcinomas than that in the matched normal mucosa (P < 0.001). Western blotting showed that 85% patients have a high level of p73 expression (more than double the normal level). A close association between p73 and VEGF expression level was observed (P = 0.016). Colorectal adenocarcinoma that expressed p73 showed significantly greater vascularity than p73-negative tumors (P = 0.012). However, no association between immunoexpression of p73 and tumor stage or differentiation was observed. CONCLUSION: These findings suggest a potential role of p73 in tumor angiogenesis.

Adenocarcinoma↗

PubMed2003

Persistent replication of the modified chimeric adenovirus ONYX-015 in both tumor and stromal cells from a patient with gall bladder carcinoma implants.

PURPOSE: ONYX-015 is a chimeric, E1B-deleted adenovirus designed to replicate preferentially in p53-deficient tumor cells; however, little is understood about its actual replication potential in human tumors. We hypothesized that replication of a late viral gene, hexon, would demonstrate replication of virus in human tissues. EXPERIMENTAL DESIGN: In the course of a clinical trial, a patient with paired abdominal wall implants from a primary gall bladder carcinoma was injected with ONYX-015, 1 x 10(10) viral particles/lesion, followed by sequential excision of the lesions at 37 h and 7 days. Tissue sections were analyzed for evidence of viral replication. RESULTS: In situ Reverse transcription-PCR was used to measure expression of hexon. Strong signals were obtained in gland-forming tumor cells both at 37 h and at 7 days. Signal was predominantly observed in the cytoplasm. The signal was also observed in adjacent normal stromal cells. Analysis of p53 status of the tumor by immunohistochemistry and Affymetrix Genechip demonstrated an inactivating mutation in p53. Routine H&E staining of the tumor sections revealed no evidence of necrosis at 37 h or 7 days after injection of virus. Presence of viral protein at both 37 h and 7 days was confirmed by immunohistochemistry using antibodies directed against hexon, penton, and fiber proteins. CONCLUSIONS: Evidence for replication of hexon confirms that ONYX-015 is not only present but capable of replicating in tumor cells up to 1 week after intralesional injection and that replication is not confined to p53-mutated tumor cells.

Adenoviridae↗

PubMed2003

[Experimental study of total nutrient admixture promoting transfection of plasmid DNA mediated with liposomes to colorectal cancer cells].

OBJECTIVE: To study total nutrient admixture (TNA) promoting plasmid DNA transfection mediated with liposomes to colorectal cancer cells. METHODS: Dispensing varied transfection agents of liposome + DNA plasmid pEGFP-N(1), TNA + liposomes + pEGFP-N(1), TNA + pEGFP-N(1), liposomes merely, and TAN sole. Human colorectal cancer cell LoVo and HR-8348 were treated with the agents respectively. Green fluorescence protein (GFP) gene as a report gene was detected. RESULTS: GFP was not detected in cancer cells treated with agents of merely liposomes and TAN. Transfection rates of GFP in two groups of cancer cells treated with agent of TNA + liposomes + pEGFP-N(1) were 33%, 38% respectively. With liposome + pEGFP-N(1), the rates of transfection in two cells were 22%, 24% respectively. The expression of GFP was 1% in the two groups of tumor cells treated with TNA + pEGFP-N(1). With agent of TNA + liposomes + pEGFP-N(1), a high transfection rate of GFP gene was obtained. And no negative effect was observed to stabilization of TAN solution. CONCLUSION: TNA may enhance transfection rate of plasmid DNA mediated with liposome, and may be beneficial to the treatment of cancer.

Colorectal Neoplasms↗

PubMed2003

[The changes of filamin distribution in renal tubular epithelial cells during kidney ischemia/reperfusion injury in neonatal rats].

OBJECTIVE: By investigating the changes of filamin distribution in renal tubular epithelial cells at different ischemia/reperfusion time stages we studied the role of filamin in kidney ischemia/reperfusion injury. METHODS: The neonatal SD rat ischemia/reperfusion model was set up. Immunofluorescent staining was used to show the distribution of filamin in renal tubular epithelial cells and the quantities of filamin were counted by ImagePlus-Pro system. RESULTS: Filamin was located around the basal plasma membrane in normal renal tubular epithelial cells. After ischemia for 0.5 h, the redistribution was not significant. After reperfusion for 0.5 h, filamin came into the cell plasma, appeared at the apex of cells and in the lumen. This kind of change was most apparent after reperfusion for 2 h and accompanied with destruction of renal tubules. The regeneration started 24 h post-ischemia. Filamin was redistributed to the basal plasma membrane. After reperfusion for 120 h, the regeneration ended and the structure of renal tubules became normal. CONCLUSION: The distribution of filamin was changed during ischemia/reperfusion injury, this change was prior to the change of actin cytoskeleton and integrin.

Actins↗

PubMed2003

[Photoluminescence spectrum of oxygen and nitrogen-doped Si-based film].

O and N-doped amorphous Si-based films were prepared by magnetron sputtering. The photoluminescence (PL) spectra from the films were measured. A series of intense PL bands located in red, green, blue, violet and ultraviolet regions were observed, whose intensities were affected by the contents of O and N and the temperature of the substrate (Ts) during deposition. Experimental results indicate that the red PL consists of wide band, which originates from quantum confinement effect, and the distinguishable peaks are related to O impurities. The green PL, which depends on N impurities, results from N defect level, and the type and position of its peaks are affected by Ts during deposition. The blue PL containing distinguishable peaks is related to complex O defect levels. The violet PL is composed of wide bands and a double peaks, and its PL intensity is influenced by the kind and content of impurity and Ts. In summary, the intense green and violet PL can be obtained when Ts during deposition is 750 degrees C and the contents of O and N impurities are moderate.

English Abstract↗

PubMed2003

Pericardial devascularization combined with preservation of Latarjet's nerves trunk in treatment of patients with portal hypertension.

OBJECTIVE: To investigate the effect of pericardial devascularization combined with preservation of Latarjet's innervation on portal hypertension. METHODS: Sixty-two patients (57 men and 5 women) have been undergone pericardial devascularization combined with Latarjet's innervation since 1984. Clinical results and postoperative complications were evaluated. RESULTS: The incidence of upper-digestive tract bleeding was 3.2% (2 patients) within 1 month after operation. Four patients (6.5%) died within 1 month after operation (3 patients received emergency operation and 1 selective operation). Among them, 3 patients died from hepatic failure, and one patient from sepsis due to subphrentic infection. Among these deaths, 3 were evaluated Child's C. After operation, the number of patients with abdominal distension, sudden diarrhea and gastric retension was 7 (11.3%), 3 (4.8%) and 0, respectively. CONCLUSION: Pericardial devascularization combined with Latarjet's innervation can preserve the normal function of gastric emptying, prevent acute lesion of the gastric mucosa, and reduce the incidence of esophageal varices rebleeding after operation.

Adult↗

PubMed2003

[Relations between trace elements in drinking water and elderly residents' cognitive function].

The relationship between trace element levels in drinking water and cognitive function was studied for elderly residents in rural areas in China. Cognitive function was measured by a Chinese translation of the Community Screening Interview for Dementia (CSI "D"). The trace elements fluoride, calcium, selenium, aluminum, iron, zinc, cadmium, lead and arsenic contents of drinking water were determined using Chinese. National Standard Methods. A mixed effects model was used to evaluate the effect of each of the elements on cognitive function while adjusting for age, sex, and education level. Several of the elements examined had a significant effect on cognitive function when they were examined in a univariate context. However, after adjusting for other elements many of these results were not significant. There was a significant quadratic effect for calcium and a significant zinc-cadmium interaction. Cognitive function increased with calcium level to a certain point, and then decreased as calcium continued to increase. Zinc showed a positive relationship with cognitive function at low cadmium levels, but a negative relationship at high cadmium levels.

Aged↗

PubMed2003

[Application of different flaps in immediate reconstruction of maxillary defect].

OBJECTIVE: To investigate the method and clinical effect of temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant on reconstruction of maxillary defect. METHODS: From February 1999 to July 2002, 8 cases of maxillary defects due to excision of cancer were repaired immediately with temporal fascia flap, free forearm flap, free iliac bone transfer and implant. Out of 8 patients, there were 6 males and 2 females, aged 32-49 years, with a disease course of 3 months to 2 years. RESULTS: Free iliac bone and forearm flap survived in all 8 cases. Osseo-integration could be seen and the implants could be used for denture repair and chew function. After 6-12 months, X-ray examination showed iliac bone healing; facial shape and functional restoration were satisfactory. CONCLUSION: Temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant is an ideal method to repair maxillary defect immediately and reconstruct its function.

Adult↗

PubMed2003

[The influence of FasL gene expression upon hepatic metastasis of colorectal carcinoma].

OBJECTIVE: To study FasL gene expression in colorectal carcinoma and its influences on biological behaviour of colorectal cancer and hepatic metastasis. METHODS: FasL gene expressions were examined with RT-PCR technique in the primary locus of colorectal cancer, mucosa adjacent to cancer, and hepatic metastasis. HR-8348 cells of human rectal cancer cell line were transfected with FasL cDNA. Cell growth suppression rates and cell response to 5-FU and carboplatin were observed and analysed with MTT method. RESULTS: FasL gene expressions were detected in the primary site of colorectal cancer (n = 58), cancer adjacent mucosa (n = 58), and hepatic metastasis (n = 28). The positive rate of FasL expression was 24% (14/58), 14% (8/58), 100% (28/28), respectively, in primary site, tumor adjacent mucoca and hepatic metastasis. FasL expression rate in hepatic metastasis was higher than that in the primary site (chi2 = 43.49, P < 0.01) and tumor adjacent mucosa (chi2 = 57.66, P < 0.01). In a group of patients with hepatic metastasis, FasL expression rate in primary site was higher than that in patients without hepatic metastasis (chi2 = 3.96, P < 0.05). In vitro experiment, positive expression of FasL was found in transfected HR-8348 cells. When 5-FU or carboplatin was added, there was a significant difference in growth suppression rate between FasL positive and control cancer cells (t = 9.02, t = 11.93, P < 0.01). Under same concentration of chemotheraputic agent, survival rate of FasL positive HR-8348 cells was higher than that of control cells. CONCLUSIONS: FasL positive cancer cells have more powerful resistance to chemotheraputic drugs. Expression of FasL gene in colorectal cancer cells is related with immune evasion to escape killing by immune cells, showing stronger drug-resistance, and it facilitates hepatic metastasis.

Adult↗

PubMed2003

[Clinical study of 102 cases of abdominal-anus resection with telescopic anastomosis of colon rectal mucosa for lower segment of rectal cancer].

OBJECTIVE: To investigate the reliability and feasibility of abdominal-anus resection with preservation of anal sphincter by telescopic anastomisis of colon rectal mucosa for middle-lower segment of rectal cancer. METHODS: A retrospective analysis was made for abdominal-anus resection with telescopic anastomosis of colon rectal mucosa in 102 cases of middle-lower segment of rectal cancer. RESULTS: No anastomotic fistula and anastomotic stenosis occurred in the 102 cases. The increased defecation was found during early stage of postoperation, about 6-12 times per day. But this was easily controlled by antidiarrheal drugs. Twelve to 18 weeks later, defecation returned to normal. Follow-up was performed in 91 patients, and the follow-up rate was 89.2%. Mean follow-up period was 4.7 years. Local recurrence rate of the carcinoma was 5.4% (5/91), and hepatic metastasis rate was 13.1% (12/91). Three-year survival rate of postoperation was 86.9% (60/80), and five-year survival rate was 70.7% (29/41). CONCLUSIONS: With telescopic anastomosis of colon rectal mucosa, colon stoma can be avoided, and anastomotic fistula can be prevented. The operation is safety and effective in preservation of anal sphincter for rectal cancer therapy.

Adult↗

PubMed2002

SU9516, a cyclin-dependent kinase 2 inhibitor, promotes accumulation of high molecular weight E2F complexes in human colon carcinoma cells.

The E2F family plays a critical role in the expression of genes required for entry into and progression through S phase. E2F-mediated transcription is repressed by the tumor suppressor retinoblastoma protein (pRb), which results in sequestration of E2F in a multiprotein complex that includes pRb. Derepression of E2F results from a series of complex phosphorylation events mediated by cyclin D/cdk4 and cyclin E/cdk2. We have employed a novel 3-substituted indolinone compound, 3-[1-(3H-imidazol-4-yl)-meth-(Z)-ylidene]-5-methoxy-1,3-dihydro-indol-2-one (SU9516), which selectively inhibits cdk2 activity (Lane et al., Cancer Res 2001;61:6170-7) to investigate these events. Electrophoretic mobility gel shift assays were performed on SU9516-treated and -untreated HT-29, SW480, and RKO human colon cancer cell extracts. Treatment with 5 microM SU9516 prevented dissociation of pRb from E2F1 in all cell lines (HT-29>RKO>SW480). Treatment effects were time-dependent, demonstrating greater inhibition at 48 hr versus 24hr in HT-29 cells. Furthermore, E2F species were sequestered in complexes with p107, p130, DP-1, and cyclins A and E. After a 24-hr treatment with 5 microM SU9516, cyclin D1 and cdk2 levels decreased by 10-60%. These findings delineate a previously undescribed mechanism for SU9516-mediated cell growth arrest through down-regulation of cyclin D1, inhibition of cdk2 levels and activity, and pan-sequestration of E2F.

CDC2-CDC28 Kinases↗

PubMed2002

[Inhibition of proliferation of human vascular smooth muscle cells by overexpression of p21 gene].

OBJECTIVE: To observe the apoptosis of human vascular smooth muscle cells (HVSMCs) transfected with p21 gene and investigate its potential mechanism. METHODS: An adenoviral expression vector with full-length cDNA of p21 gene insert (Ad-p21) was constructed and transfected into HVSMC. A mock vector, pAdeno-X-lac Z constructed with the same method, was transfected into HVSMCs as control. Western blotting and DS-PAGE were used to detect the expression of p21 gene. Fluorescence staining was used to observe the changes in nuclei of apoptotic cells and calculate the cell survival rate. Expression of tissue transglutaminase (tTG) in HVSMC was examined by DIG-marked probe. RESULTS: Fluorescence staining showed marked fragmentation of nucleus and pyknosis of chromatin in pAdeno-X-p21 transfected cells. The expression of tTG was at a higher level in pAdeno-X-p21 transfected cells than in normal cells and pAdeno-X-lac transfected HVSMCs. CONCLUSION: Overexpression of p21 gene inhibits the proliferation of HVSMC through apoptosis induced by p21 which may relate with overexpression of tTG.

Apoptosis↗

PubMed2002

Therapeutic effects of NaFeEDTA-fortified soy sauce in anaemic children in China.

The therapeutic effects of NaFeEDTA-fortified soy sauce on anaemic students were investigated. Three hundred and four iron-deficient anaemic school children (11-17 years) were randomly assigned to three treatment groups: control group (consuming non-fortified soy sauce), low-NaFeEDTA group (consuming fortified soy sauce, providing 5 mg Fe/day) and high-NaFeEDTA group (consuming fortified soy sauce, providing 20 mg Fe/day). Blood haemoglobin (Hb) levels were determined before and after 1 month, 2 months and 3 months of intervention. In addition, serum iron (SI), serum ferritin (SF), free erythrocytic porphyrin (FEP), total iron binding capability (TIBC) and transferritin (TF) were measured before and after consumption of soy sauce for 3 months. The results obtained herein show that the parameters measured were not changed remarkably within the 3-month intervention in the control group (P < 0.05). However, increased Hb, SI, SF and TF levels and decreased TIBC and FEP levels were observed in both the high-NaFeEDTA group (P <0.01) and the low-NaFeEDTA group (P < 0.05). The effectiveness of iron intervention in the low-NaFeEDTA group and high-NaFeEDTA group had no statistical significance after 3 months. It was concluded that nutritional intervention for anaemic students using NaFeEDTA-fortified soy sauce could play a positive role in the improvement of iron status and control of anaemia.

Adolescent↗

PubMed2002

The x-ray sensitivity of amorphous selenium for mammography.

A study of the x-ray sensitivity of amorphous selenium (a-Se) for digital mammography has been performed. A uniform layer of a-Se was deposited on a glass substrate with electrodes on both surfaces. The deposition procedure was identical to that used for a-Se flat-panel detectors. A high voltage was applied to the top surface of the a-Se layer in order to establish an electric field E(Se). Then the sample was exposed to x rays with 27 kVp spectra generated from an x-ray tube with a molybdenum (Mo) target. The mean x-ray energy of the spectrum used was approximately 16.6 keV. The x-ray current generated by the a-Se layer was measured as a function of E(Se). From the current measurement and the estimation of total x-ray energy absorbed in the a-Se, the energy required to create one electron-hole pair (EHP), W, was determined as a function of E(Se). It was found that at the most commonly used E(Se) of 10 V/microm, W was measured as 64 eV. This is considerably higher than the widely accepted typical value of W = 50 eV measured at higher x-ray photon energies (e.g., 50 keV). The dependence of W as a function of E(Se) can be best fitted using the empirical expression of E(Se)-gamma. This relationship is consistent with the results obtained at higher x-ray energies. This article provides an accurate measurement of x-ray sensitivity of a-Se at mammographic energies independent of detector operation, such as the most recently developed flat-panel detectors. The results will be a useful tool for investigation and optimization of a-Se-based x-ray imaging detectors, such as determination of pixel fill-factor and optimal E(Se) during operation.

Electrons↗

PubMed2002

[X-ray combined with cytosine deaminase suicide gene therapy enhances killing of colorectal carcinoma cells in vitro].

OBJECTIVE: To study the effect of X-ray on gene transfer and the antitumoral effect of X-ray combined with suicide gene therapy on colorectal carcinoma cells. METHODS: Green fluorescent protein (GFP) was seen under fluorescent microscope. GFP gene was used for reporting gene to learn gene transfer efficiency and gene expressing time under the influence of radiation. G418 was used to select cytosine deaminase (CD) positive neoplasm cells and CD gene transfer efficiency was tested by cloning efficiency. Antitumoral effect of X-ray combined with CD and 5-FC on colorectal carcinoma cells was tested by MTT. RESULTS: 4 Gy radiation could improve supercoiled plasmid DNA transfer efficiency for about 2 - 4 times and 30 times for linearized plasmid DNA. The mean durations of GFP gene expression treated with 4 Gy radiation were 14 d for supercoiled plasmid and 21 and for linearized plasmid, while in control group, the time was 12 d. Middle-dose radiation combined with CD and 5-FC could kill 99 percent of colorectal carcinoma cells, while in the control group, 5-FC only killed 15 percent of colorectal carcinoma cells which were transduced with CD gene. CONCLUSIONS: X-Ray combined with suicide gene therapy may be used as a promising method for treating colorectal neoplasm.

Antimetabolites↗

PubMed2002

[Expression of human mammaglobin mRNA in peripheral blood of breast cancer and their implication].

OBJECTIVE: To study the expression of human mammaglobin (hMAM) mRNA in the peripheral blood of breast cancer patients and its implication. METHODS: The expression of human mammaglobin mRNA was determined by using RT-PCR method in 56 patients with peripheral blood breast cancer, 8 patients with breast hyperplasia and 8 women with normal breast. The expression of hMAM mRNA was compared with biological significance and change of hMAM mRNA in chemotherapy after operation. RESULTS: The expression of hMAM mRNA was negative in 8 patients with breast hyperplasia, 8 women with normal breast and 56 patients with breast cancer, The positive rate was 30.4% (17/56) (chi(2) = 19.766, P < 0.01). The expression of hMAM mRNA in peripheral blood was not correlated with clinical stage, primary tumor size and patients age (chi(2) = 1.256, P > 0.05). After short-term large dose of chemotherapy, 41.2% (7/17) patients turned positive before operation to negative hMAM mRNA expression and negetive expression before operation positive expression after chemotherapy. CONCLUSIONS: This study suggests that hMAM is sensitive and specific for breast cancer. Detection of the expression of hMAM mRNA in peripheral blood of breast cancer is of value in the diagnosis and judgement of prognosis of breast cancer.

Adult↗

PubMed2002

[Three-pronged approach to treat rectal cancer: liposome transfer cytosine deaminase gene, ionizing radiation and dendritic cells].

OBJECTIVE: To investigate the anticancer activity of three-pronged approach: liposome transfer cytosine deaminase (CD) gene, ionizing radiation, and dendritic cells (DCs). METHODS: After rectal cancer cells were killed by CD and 5-FC and radiotherapy with improved liposome transfection and radiosensitization, the killed cancer cells, DCs and T lymphocytes were incubated together. The uptake of (3)H-TdR weighed the immune activity of DCs. The effect of anticancer was monitored by MTT. RESULTS: DCs acquired the apoptosis body and other antigen from the killed cancer cells and presented them to T-lymphocytes. The induced CTL killed the cancer cells powerfully and selectively. The mortality of rectal cancer cells was 98.1%, 76.2%, 37.8% at the ratio of efficacy to target of 30:1, 15:1, 1:1, respectively. CONCLUSION: The three-pronged approach may represent a powerful and safe means to selectively destroy cancer cells.

Combined Modality Therapy↗

PubMed2002

[Long-term results of extended parietal cell vagotomy in treatment of duodenal ulcers and their complications: report of 321 cases].

OBJECTIVE: To study the long-term results of extended parietal cell vagotomy (EPCV) in the treatment of patients with duodenal ulcer and their complications. METHODS: Form 1979 to 2001, EPCV was performed in 321 patients with duodenal ulcer and their complications. Of these patients 56 had chronic duodenal ulcer, 204 perforation, 16 hemorrhage and 40 stenosis. The following items were evaluated: complications of operation, gastric secretion, gastric emptying, endoscopical and radiographical findings, nutritional status, absorption function, and Visick scale. RESULTS: Postoperative follow-up ranged from 0.5 to 22.0 years (mean 11.3 years) in 289 of the 321 patients with a follow-up rate of 90.0%. Neither operative mortality nor dumping syndrome was noted. Episodic postprandial fullness occurred in 19 patients (6.5%), acid regurgitation in 17 (5.8%) and adhesive ileus in 4 (1.4%). Ulceration recurred in 16 patients (5.5%). Duodenal ulcer was seen in 8 patients (19.5%), hemorrhage in 0 (0%), stenosis in 2 (5.3%), and perforation in 6 (3.1%). Ulcers healed rapidly after medical therapy in 10 patients. Six patients received antrectomy and gastrectomy. In 289 (91.7%) patients of Grade I and II of Visick scale, 191 (95.3%) had perforation. CONCLUSIONS: EPCV is easy to perform with a low rate of post operative complication and ulcer recurrence. It should be a treatment of choice for acute perforation, hemorrhage or stenosis due to duodenal ulcer.

Duodenal Ulcer↗