1.Cardiac Protection during Open Heart Surgery: A View from Coronary Endothelial Function
Journal of Sun Yat-sen University(Medical Sciences) 2005;26(6):601-606
Cardioplegic (and organ preservation) solutions were initially designed to protect the myocardium (cardiac myocytes) during cardiac surgery (and heart transplantation). Due to the differences between the cardiac myocytes and vascular (endothelial and smooth muscle) cells in structure and function, the solutions may have adverse effect on coronary vascular cells. However, such effect is often complicated by many other factors such as ischemiareperfusion injury, temperature, and perfusion pressure or duration. In evaluation of the effect of a solution on the coronary endothelial function, a number of points should be taken into consideration. First, the overall effect on endothelium should be identified. Second, the effect of the solution on the individual endothelium-derived relaxing factors (nitric oxide, prostacylin, and endothelium-derived hyperpolarizing factor) must be distinguished. Third, the effect of each major component of the solution should be investigated. Fourth, the effect of a variety of new additives in the solution may be studied. In the last decades, we have focused our research on the endothelial function during open heart surgery and have for the first time found that high potassium concentration impairs the EDHF-mediated function. This review attempts to discuss the above issues based on available literature in order to provide information for further development of cardioplegic or organ preservation solutions.
2.Perspective on Metabolic Syndrome in China
C.w.wong NORMAN ; Haipeng XIAO
Journal of Sun Yat-sen University(Medical Sciences) 2005;26(1):1-3
Metabolic syndrome is on the rise in China. An improved understanding of the criteria for the diagnosis of this syndrome will lead to important questions for the population in China. The progression of this syndrome to type 2 diabetes mellitus(DM) is a dreaded outcome that may be prevented. Once DM is established,knowledge of the current therapeutic approaches is required.
3.Construction of Eukaryotic Expression Recombinant Plasmid and Sequence Analysis of p41-3 Gene of Plasmodium Falciparum Isolate FCC1/HN
Zhixin SHAN ; Xinbing YU ; Xuerong LI ; Changling MA ; Jiahai LU ; Jin XU
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(5):329-334
[Objective] To construct a eukaryotic expression plasmid containing a gene encoding a 41-3 kilodalton blood stage antigen (p41-3) of Plasmodiu falciparum isolate FCC1/HN, and to determine the sequence of p41-3 gene and analyze the homology of the sequences of 341-3 gene of different P. falciparum isolates. [ Methods] Two pairs of primers were designed according to the known sequence of p41-3 gene. Using PCR technique, the p41-3 gene was obtained by amplification from genomic DNA of isolate FCC1/HN. By cloning target gene into a eukaryotic expression vector, pcDNA3, a recombinant plasmid pcDNA3-p41-3 was con structed and trarsferred into E. coli DH5α. The positive clones were screened and identified by agarose gel electrophoresis, endonu clease digestion and PCR technique. The correct recombinant plasmid pcDNA3-p41-3 was used as template, and the nucleotide se quence of p41-3 gene was determined by the dideoxy chain termination method. Using softwares to analyze the structure and sequence homology of p41-3 gene between isolate FCC1/HN and FCBR. [Results] The p41-3 gene was specifically amplified from genomic DNA of Plasmodiumm falciparum isolate FCC1/HN, and the correct recombinant plasmid pcDNA3-p41-3 was screened and identi fied. The result of sequence determination showed that the p41-3 gene of isolate FCC1/HN was 2 137 base pairs in full length, encod ing 375 amino acids. Isolate FCC1/HN and isolate FCBR exhibited 98.98 % homology in the nucleiotide sequences and 99.73 % ho mology in the encoded anino acids of p41-3 gene. [Conclusion] The eukaryotic expression plasmid pcDNA3-p41-3 is successfully con structed and nucleotide sequence of p41-3 gene of isolate FCC1/HN is determined. The p41-3 genes of isolate FCC1/HN and isolate FCBR share quite high homology.
4.An Inhibitor of p38 MAPK Prevents Apoptosis of Cultured Cerebellar Granule Neurons via Inhibiting the Activity of JNK
Mingtao LI ; Wenya WANG ; Juan SUN ; Xiaoli TANG ; Xingwen SU ; Pengxin QIU ; Guangmei YAN
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):165-169
【Objective】To study the effect of the specific p38 mitogen-activated protein kinase(p38 MAPK) inhibitor SB203580 on apoptosis of cerebellar granule neurons induced by low potassium.【Methods】Apoptosis was induced by switching the cultured cerebellar granule neurons from a culture medium containing K+ 25 mmol*L-1 to a medium containing K+ 5 mmol*L-1 (cLK).Fragmentation of DNA was analyzed using agarose gel eletrophoresis.SAPK/JNK activity was measured by SAPK/JNK assay kit.【Results】Low potassium resulted in apoptosis as characterized by morphological and biochemical features,but the specific p38 MAPK inhibitor SB203580 improved the survival of cerebellar granule neurons cultured in cLK medium by blocking apoptosis in a concentration-dependent manner.The expression and phosphorylation of c-Jun increased and the activity of c-Jun N-terminal protein kinase (JNK) elevated when cerebellar granule neurons were cultured in cLK medium.But when the cerebellar granule neurons cultured in cLK medium were exposed to 25 μmol*L-1 SB203580,the expression and phosphorylation of c-Jun and the activity of JNK were both decreased evidently.【Conclusions】These results indicate that SB203580 inhibits the activation of JNK and phosphorylation of c-Jun,and therefore protects granule neurons from apoptosis induced by low potassium.
5.Cloning and Sequencing of the Human Thalassemic Gene β654
Xiaowu FANG ; Ruiping ZENG ; Bin HU
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):174-176
【Objective】In order to establish the foundation for transgenic mouse model,the human thalassemic gene(β654) was cloned and sequenced.【Methods】The human β654 gene was amplified by PCR,and cloned into the plasmid BGT51 in which the human β gene was cut out aforehand.The recombinant plasmid was certified by enzyme-digestion,reverse dot hybridization and sequencing.【Results】A recombinant plasmid was obtained,which contained the human β654 gene in the correct recombinant direction.Sequencing showed that the cloned insert was correct.【Conclusions】The recombinant plasmid constructed is useful for establishing a transgenic mouse.
6.Cloning,Expression and Activity Detection of Vascular Endothelial Growth Factor
Zijun LI ; Pingjin HU ; Xiyong YU
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):177-179
【Ojective】To clone,express and detect activity of VEGF165.【Methods】Using human heart cDNA library as template,amplified the VEGF gene by PCR.The PCR product was ligated to PUC19 plasmid and sequenced.A eukaryotic expression plasmid AdtrackCMV harbouring VEGF165 was constructed.,then transformed into 293 cells.RNA dot blot and Western blotting were performed to demonstrated whether the tranfermants expressed VEGF165 at mRNA and protein level respectively.Furthermore the bio-activity of VEGF165 was preliminarily detected with Miles test.【Results】Sequence of 582bp VEGF165 cDNA was proved correct by sequencer analysis.The expression of VEGF165 mRNA was identified by RNA dot blot,Western blotting indicated that the molecular weight of VEGF165 protein was 22ku.VEGF165 also is of vascular permeability.【Conclusion】VEGF165 gene has been successfully cloned and expressed,which makes a basis for the further study in vivo.
7.Effect of Stent Implantation on the Expression of PCNA and Cyclin E and Apoptosis in Rabbit Vascular Smooth Muscle Cells
Yingmei LIU ; Xuming ZHANG ; Wei WU ; Yingling ZHOU
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):180-183
【Objective】To evaluate the impact of stent implantation on proliferation and apoptosis in media vascular smooth muscle cells and to explore the mechanism of restenosis after stent implantation.【Methods】Fifty male New Zealand rabbits were randomized into balloon group and stent group.Control group were set up.The materials were harvested on 3,7,14,28 and 56 day after operation and the following investigation were carried out.① Assessing the expression of proliferating cell nuclear antigen (PCNA) and Cyclin E of media smooth muscle cells with immunohistochemistry;② Analyzing apoptosis of media smooth muscle cells by TUNEL technique.【Results】The expressions of PCNA,Cyclin E and apoptosis in stent and balloon groups were markedly increased compared to control groups.① Stent group induced significant increased expression of PCNA and Cyclin E in the media smooth muscle cells compared to balloon group.On day 7,the positive rates of PCNA and Cyclin E were 24.36±0.55% vs 18.74±1.09% (P<0.01) and 22.65±1.00% vs 17.68±1.10% (P<0.01) respectively;② Stent group induced much more significant apoptosis than balloon group.The highest rate of apoptosis appeared on day 7:12.46±1.13% vs 5.54±0.53% (P<0.01);③By calculating the ratio of positive rates of PCNA to apoptosis and Cyclin E to apoptosis respectively,the ratio of balloongroup was higher than that of stent group.【Conclusion】Stent group induces augmented proliferation and much more significant apoptosis of media smooth muscle cells compared to balloon group.It shows that the severity of restenosis is relieved after stent implantation.
8.Effect of Light Weight-bearing Activity on Bone Mineral Density,Histomorphometry and Biomechanics in Ovarietomized Rats
Bailing CHEN ; Weiming LIAO ; Fobao LI ; Ming FU ; Dongliang XU
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):187-191
【Objective】To study the effect of light weight-bearing activity on postmenopausal osteoporosis.【Methods】36 female rats were randomly divided into 3 groups:① Sham,② Ovx (ovarietomized),③ Ovx+Im (ovarietomized and immobilized).All the group's maintained daily activity.And because of being immobilized,the right hind limbs of the third group lacked weight-bearing activity.12 weeks after ovarietomy,the BMD (bone mineral density),histomorphometry and biomechanics of the right femurs of rats were measured and analyzed.【Results】Comparing with the Sham group,the Ovx group's right femurs were manifested with the decrease of BMD,TBV (trabecular bone volume),MTT(mean trabecular thickness) and MCT(mean cortex thickness),while the increase of RS(resorption surface) and OS(osteotoid surface).Meanwhile their biomechanic nature declined.But statistically the BMD,MCT and the criteria of mechanical strength were not significant decrease.Otherwise,the Ovx+Im group's right femurs showed more apparent decrease of BMD,TBV,MTT and MCT.And the biomechanic nature was worse.Comparing with the Sham group,the BMD,MCT and the criteria of mechanical strength of the Ovx+Im group were statistically significant decreased.【Conclusion】If maintaining light weight-bearing activity,the ovarietomized rats were able to maintain relatively better bone quality.A lack of light weight-bearing activity wouldcause thedecline of bone quality.Thusthestudy suggested light weight-bearing activity was significantly effective on the prevention and treatment of postmenopausal osteoporosis.
9.Relationship Between the Expression of Lymphocyte Function-associated Antigen-1 on Peripheral Lymphocytes and Acute Rejection After Liver Transplantation
Yuyang FU ; Xiaoshun HE ; Jianlin CHEN ; Guihua CHEN ; Jiefu HUANG
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):192-194
【Objective】To investigate the relationship between the expression of lymphocyte function-associated antigen-1 (LFA-1) on peripheral lymphocytes and acute rejection after orthotopic liver transplantation (OLTx) in rat.【Methods】Adult male rats were divided into 2 groups.In the non-rejection group,40 SD rats were used as both donors and recipients.In the rejection group,20 Wistar rats were used as donors and 20 SD rats as recipients.Blood samples were collected through the tail vein 1 day before transplantation and on days 1、3、5、7 after OLTx.The expression of LFA-1 (CD11a) on peripheral lymphocytes was analyzed by using indirect immunofluorescent marker-flow cytometry.【Results】The expression level of LFA-1 on peripheral lymphocytes in recipient rats after orthotopic liver transplantation was markedly lower than that before operation (P<0.01);The expression level of LFA-1 on peripheral lymphocytes in rats with acute liver rejection was significantly higher than that in the non-rejection group (P<0.01).【Conclusion】Monitoring the expression level of LFA-1 on peripheral lymphocytes may be helpful to the diagnosis of acute graft rejection.
10.Corelation of PI3-K Phosphorylated Products and Th2 Cytokine in Patients with Active Lupus Nephritis
Jianqin WANG ; Youji LI ; Zhijian LI ; Dihua ZHANG ; Daoyuan ZHOU ; Hanshi XU ; Rengao YE
Journal of Sun Yat-sen University(Medical Sciences) 2001;22(3):195-198
【Objective】To observe the expression of PI3-K phosphorylated products and elucidate the correlation between PI3-K phosphorylated products and Th2 cytokine in peripheral blood mononuclear cell (PBMC).【Methods】14 patients with active lupus nephritis and 12 controls were selected,PI3-K phosphorylated products were detected by immunoprecipitation and Western blotting,RT-PCR was used to observe interleukin-6 mRNA and interleukin-10 mRNA expression.【Results】In either spontaneous condition or stimulated by anti-CD3 antibody,the expression of PI3-K phosphorylated products in patients with active lupus nephritis were higher than those of the controls(1.14±0.23 vs 0.46±(0.12,P=0.023;2.09±0.63 vs 0.65±0.14,P=0.016).The expression of PI3-K phosphorylated products in active lupus nephritis showed a positive correlation with interleukin-6 mRNA and interleukin-10 mRNA (r=0.652,P=0.008;r=0.718,P=0.007).PY294002,one of specific inhibitor of PI3-K,inhibited significantly the expression of interleukin-6 mRNA(2.32±0.51 vs 0.57±0.15,P=0.009) and interleukin-10 mRNA (1.71±0.33 vs 0.67±0.11,P=0.006) in stimulated PBMC in active lupus nephritis.【Conclusion】PI3-K can involve in the pathogenesis of lupus nephritis by inducing the overexpression of interleukin-6 and interleukin-10.