Biomedical subjects

Li Jiang

Publications and source records attributed to Li Jiang.

113 records · Page 7Linked to original sources

PubMed2002

[Ectopic expression of cyclin G2 inhibits cell proliferation in HeLa cancer cell line].

BACKGROUND & OBJECTIVE: Cyclins are important proteins in cell cycle machinery, acting as positive regulators in cell proliferation. Cyclin G2 may exceptionally be a negative regulator since its expression could be induced by DNA damage and the VHL tumor suppressor protein. Furthermore, down-regulated cyclin G2 was detected in oral squamous cell carcinomas. The current study was aimed at clarifying the effects of cyclin G2 transgene expression on proliferation of cancer cells in vitro. METHODS: Cyclin G2 cDNA was synthesized by reverse transcription-polymerase chain reaction (RT-PCR) and inserted into the pIRESneo vector at BamH I and BstX I sites to generate the recombinant plasmid pIRES-G2. The pIRES-G2 and pIRESneo plasmids were then individually introduced into HeLa cancer cell line through lipofectamine mediated transfection. After two weeks' selection in culture medium containing G418, the number of colonies was counted and the transfectant cells were morphologically observed. RESULTS: The colony-forming efficiency of the cells transfected with pIRES-G2 construct was much lower compared with that with the control parental vector pIRESneo. The colony numbers were 76.7 +/- 24.8 and 18 +/- 10.4 in control and experimental groups, respectively, with a colony forming rate of 23.4% in the pIRES-G2 group. Furthermore, pIRES-G2 transfected cells showed a senescent morphology. CONCLUSION: Ectopic overexpression of cyclin G2 in cancer cell line HeLa could inhibit cell proliferation significantly.

Cell Division↗

PubMed2002

[Cloning and expression of the mouse Doc-1R gene].

BACKGROUND & OBJECTIVE: Doc-1R gene is a new gene which was cloned in 1999. Recent studies suggest that Doc-1R gene is a potential tumor suppressor gene. In order to study the function of the Doc-1R gene, The aim of this study was to obtain its genomic sequences and to analyze its expression in the tissues. METHOD: According to the cDNA sequences of Doc-1R gene, the gene-specific primers were designed and synthesized. The sequence of Doc-1R gene was cloned through nested PCR using the Genome Walker kit. The sequence and splice donor/acceptor site were analyzed. Using the reverse transcription polymerase chain reaction(RT-PCR), the expression of Doc-1R gene in thirteen tissues, including mouse liver, spleen, pancreas, kidney, lung, intestine, heart, brain, bone, muscle, bladder, ovary, spermary were determined. RESULTS: The mouse Doc-1R gene has been obtained by two times genomic walking. This gene spans 2,787 bp and contains four exons and three introns. All of the splice donor/acceptor site sequences were in accordance with the consensus "GT-AG" rule. RT-PCR experiments demonstrated Doc-1R gene was expressed in the 13 tissue samples. CONCLUSION: The authors have successfully cloned the mouse Doc-1R gene, which will be the foundation for further investigating the function of that gene. The expression pattern suggests that the Doc-1R gene is a housekeeping gene which is important to keep the function of tissues and organs.

Animals↗

PubMed2002

Vascular and biliary complications after liver transplantation: interventional treatment.

OBJECTIVE: To evaluate the value of angiography and cholangiography on the diagnosis and interventional treatment of vascular and biliary complications after liver transplantation. METHODS: Sixteen of 46 patients (15 men and 1 woman, 17 - 60 years old) after orthotopic liver transplantation received angiography due to abnormal ultrasonography or edema of lower limbs, or cholangiography due to progressing jaundice. Percutaneous transluminal angioplasty or drainage was performed in some patients. RESULTS: Fifteen patients experienced vascular complications and 4 patients had biliary complications. Three of them appeared to have both vascular and biliary complications. Hepatic artery complications were the most common complications (9/16), including hepatic artery thrombosis or stenosis (6/9), bleeding (2/9) and hepatic artery-dissecting aneurysm (1/9). One patient with hepatic artery thrombosis received transcatheter thrombolysis and two patients with bleeding received coil embolization. Inferior vena cava and portal vein stenosis were observed in 6 and 2 patients, respectively. After balloon angioplasty or stent placement, clinical symptoms were alleviated. Biliary complications, including biliary stricture and anastomotic bile leak, occurred in 4 patients. Jaundice decreased after percutaneous transhepatic cholangiography and drainage. CONCLUSIONS: Besides diagnosis, interventional methods include mini-invasive treatment for patients with vascular and biliary complications after liver transplantation. Balloon angiography and stent placement for venous stenosis are useful procedure for the treatment of these problems.

Adolescent↗

PubMed2001

Inhibition of Scavenger Receptor A Expression Treated with PMA by the Inhibitor of Tyrosine Protein Kinase Genistein.

In order to investigate the relationship between scavenger receptor type A and cell signal transduction, human U937 macrophages were treated with tyrosine protein kinase inhibitor genistein, then the cells were incubated with [(125)I]ox-LDL or ox-LDL, and the cellular degradation of [(125)I]ox-LDL or binding were measured separately. Then the effect of the drug on cell surface expression of SR-A were measured by means of autoradiography, it was found that genistein could reduce cellular SR-A mRNA transcription by RT-PCR. The results indicated that genistein could reduce U937 macrophages to bind lipids and reduce SR-A expression by suppression of transcription, and could reduce degradation of lipids by U937 macrophage and accumulation of cholesterol within the cells. It suggests that the function of scavenger receptors may be correlated with cell tyrosine protein kinase, the mechanism is transcriptional and it also suggests that SR-A may participate in the signal transduction directly.

Journal Article↗

PubMedDate not supplied

Automated quantification of body fat distribution on volumetric computed tomography.

OBJECTIVE: To develop a computerized method to automatically quantify visceral and subcutaneous fat distribution within the abdomen and pelvis on volumetric computed tomographic (CT) images. METHODS: Given the slices of interest, the algorithm automatically delineates a contour that separates the visceral fat from the subcutaneous fat on each slice. Explicitly, starting with extraction of the body perimeter, radii at a fixed angle increment are drawn from the perimeter to the center of the body. Along each radius, intensity profile is analyzed to determine the point on the subcutaneous fat layer that is closest to the body center (inner point). All inner points are then connected to form an inner contour, and a specific smoothing algorithm is subsequently applied to correct suboptimal results. Pixels having HU values between -190 and -30 are considered fat pixels. This procedure is repeated on each of the slices of interest. The visceral and subcutaneous fat volumes computed automatically were compared with those after the radiologist's adjustments. Ratios of volumetric visceral fat-to-total fat and visceral fat-to-subcutaneous fat were compared on average and with single-slice measurements obtained at L4 and L5 vertebral body levels. RESULTS: Subcutaneous and visceral fat were automatically segmented using this algorithm on 419 axial CT slices in 9 CT scans (patients) within the abdomen and pelvis. The overall average percentage difference between the automated segmentation and the segmentation edited by the radiologist were 1.54% for the visceral fat and 0.65% for the subcutaneous fat. CONCLUSIONS: Preliminary results have shown that total compartmental fat, including visceral and subcutaneous fat, can be automatically and accurately segmented on volumetric CT.

Abdominal Fat↗