Volume 117  ·   Issue 08  ·  2004

Background Spleen in Traditional Chinese Medicine (TCM) is not actually the spleen in the anatomic sense designated in western medicine because its functions basically belong to the physiological category of digestive system in modern medicine, and it represents a macroscopic concept of digestion, absorption and nutrition metabolism. Spleen deficiency syndrome refers to the clinical phenomena such as hypofunction of digestion, absorption and nutrition metabolism. By integrating TCM with modern medicine, this paper is intended to explore the pathological basis of classification of spleen deficiency in chronic gastritis. Method By means of optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical staining, we conducted histopathological and subcellular ultrastructural (nuclei and mitochondrial) analysis of gastric mucosa of 188 patients of spleen deficiency, and that of 42 voluntary blood donors without clinical symptoms. Results The gastric mucosa of patients with spleen Qi deficiency (SQD) and spleen yang deficiency (SyangD) could either be affected by organic lesion (type G-occurring on the basis of chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG)) or unaffected (type F-chiefly belonging to functional indigestion); spleen yin deficiency (SyinD) and spleen deficiency with Qi stagnation (SDQS) both occurred on the basis of CSG and CAG; and the degree of mucosa inflammatory cells infiltration, the degree of decrease in glands propria, and the incidence of IM Ⅱb in CSG and CAG were more serious than those of G-SQD and G-SyangD, P <0. 05 -0. 01. Conclusion Spleen deficiency syndrome is likely to occur on the basis of organic lesion of gastric mucosa (disease with symptoms of both CSG or CAG and spleen deficiency symptoms), as well as on the basis of inorganic lesion of gastric mucosa (nondisease with symptoms, which is, despite spleen deficiency symptoms, there is no CSG or CAG). Besides, the clinical phenomenon of disease without symptoms (despite CSG or CAG, there is no spleen deficiency symptoms) occurres because of such factors as genetic diathesis and compensation. The lesion degree of CSG or CAG and the incidence of IM Ⅱb of SyinD and SDQS are more serious than those CSG and CAG of G- SQD and G-SyangD. Chin Med J 2004; 117(8):1246-1252

Background Studies on human, rat and chicken embryos have demonstrated that during the period of outflow tract septation, retraction of the distal myocardial margin of the outflow tract from the junction with aortic sac to the level of semilunar valves leads to the shortening of the myocardial tract. However, the mechanism is not clear. So we investigated the mechanism of outflow tract shortening and remodeling and the spatio-temporal distribution pattern of a-SMA positive cells in the outflow tract cushion during septation of the outflow tract in the embryonic mouse heart. Methods Serial sections of mouse embryos from embryonic day 9 (ED 9) to embryonic day 16 (ED 16) were stained with monoclonal antibodies against α-SCA, α-SMA, or desmin, while apoptosis was assessed using the terminal deoxyribonucleotidy transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay. Results Between ED 11 and ED 12, the cardiomyocytes in the distal portion of the outflow tract were observed losing their myocardial phenotype without going into apoptosis, suggesting that transdifferentiation of cardiomyocytes into the cell components of the free walls of the intrapericardial ascending aorta and pulmonary trunk. The accumulation of a-SMA positive cells in the cardiac jelly began on ED 10 and participated in the ridge fusion and septation of the outflow tract. Fusion of the distal ridges resulted in the formation of the facing walls of the intrapericardial ascending aorta and pulmonary trunk. Fusion of the proximal ridges was accompanied by the accumulation of a-SMA positive cells into a characteristic central whorl, in which cell apoptosis could be observed. Subsequent myocardialization resulted in the formation of the partition between the subaortic and subpulmonary vestibules. Conclusions The shortening of the embryonic heart outflow tract in mice may result not from apoptosis, but from the trans-differentiation of cells with cardiomyocyte phenotype in the distal portion of the outflow tract into the cell components of the free walls of the intrapericardial ascending aorta and pulmonary trunk. The primary roles of a-SMA positive cells in the septation and remodeling of the outflow tract may assure proper fusion of the outflow ridges and form the facing walls of the intrapericardial ascending aorta and pulmonary trunk. Chin Med J 2004; 117(8):1240-1245

Background This study was designed to detect methylation of E-cadherin gene promoter and gene mutation of β-catenin in exon 3 and their expression of protein and mRNA in primary tumor and lymph node metastatic tumor of nasopharyngeal carcinoma (NPC), and investigate the mechanism of invasion and metastasis of neoplastic cells in NPC. Methods Fourty-two fresh biopsy samples were taken from untreated NPC patients at the Affiliated Hospital of Sun Yat-sen Medical College, Sun Yat-sen University, Guangzhou, China during the period of 1999-2002. Among them 21 were taken from primary tumors and the other 21 from lymph node metastatic tumors. The gene promoter methylation of E-cadherin was detected by methylation-specific PCR (MSP). The mutation in exon 3 of β-catenin was detected by direct sequencing analysis. RT-PCR, Western blot and immunohistochemical staining were used to detect the mRNA and protein expression patterns in both primary and metastatic tumors of NPC. Results Down-regulated expression of E-cadherin in metastatic tumor was compared with that in primary tumor. Reduced expression of E-cadherin was found to be correlated with lymph node metastatic tumor of NPC (P = 0.004); but there was no obvious correlation between primary and metastatic tumors in the expression of β-catenin (P = 0. 698). The mRNA expression level of E-cadherin in metastatic tumors decreased significantly compared with that in primary tumors. However, little change was observed in the mRNA level of β-catenin in different tumor tissues. Only 4 samples (19. 1%) displayed gene promoter methylation of E-cadherin in primary tumor and 10 samples (47. 6%) showed methylated form of E-cadherin. The gene promoter methylation of E-cadherin was more common in metastatic tumor than in primary tumor of NPC (P = 0. 024). Only 2 (4. 76%) of the 42 samples showed mutations in exon 3 of β-catenin at 41 (T41A, ACC→GCC) and codon 47 (S47T, AGT→ACT). The cytoplasmic and nuclear expression of β-catenin in tumor was not found in any samples of NPC. Conclusions The results suggest that the downregulation of E-cadherin results from the gene promoter aberrant methylation of E-cadherin and that the methylation of E-cadherin plays an important role in invasion and metastasis of tumor cells in NPC. However, β-catenin mutation is an infrequent event in NPC, and β-catenin is not a critical factor influencing the invasion and metastasis of tumor cells in NPC. Chin Med J 2004; 117(8):1232-1239

Background Extracellular matrix (ECM) orchestrates cell behaviour including growth, death, apoptosis, adhesion, migration, and invasion by activating several signalling pathways. Certain components of ECM, such as integrins, may act as receptors or co-receptors of enterovirus. ECM-activated gene expressions in myocardium of viral heart disease including myocarditis and partial cardiomyopathy remain elusive. This study was to investigate the expression of ECM-activated genes in myocardium of mouse with viral myocarditis. Methods BALB/c mice were infected with Coxsackie virus B3 (CVB3) to establish an animal model of myocarditis. Uninfected mice were also prepared and served as controls. Specific mRNA expression pattern in myocarditic mouse heart was analysed by an in-house cDNA microarray containing 8192 genes. Overexpressed ECM genes were selected and subsequently confirmed by Northern blot analysis. Results Nine ECM genes were isolated, from the array of 8192 genes, as overexpressed genes in hearts of myocarditic mice in comparison with controls. Subsequent Northern blot analysis confirmed that four of the nine genes were highly expressed. Expression of these four genes, Fin15, ILk, Lamr1 and ADAMTS-1, has not been reported previously to be induced by Coxsackie virus. Conclusion CVB3-induced myocarditis is associated with gene expression profiles of certain ECM components. Chin Med J 2004; 117(8):1228-1231

Background After T-cell depleted allogeneic bone marrow transplantation, impaired immune reconstitution is a major cause of morbidity and mortality in the recipient. The purpose of this study was to observe the effects of the gene-engineered bone marrow stromal cell line QXMSC1-IL-2 + IL-3 on the reconstitution of T-cell immunity in allo-BMT mice. Methods The bone marrow stromal cell line QXMSC1 was co-transfected with IL-2 and IL-3 genes using a Tet-on gene expression system. T lymphocyte subset counts per spleen were analyzed by flow cytometry. Lymphocyte proliferation response to ConA was examined to evaluate T-cell function. CDR3 spectratyping techniques were performed to evaluate TCR repertoire diversity at various time points post-transplantation. Results Gene engineered bone marrow stromal cell line QXMSC1-IL-2 + IL-3 could express IL-2 and IL-3 (1300 ng • day-1 • 10-6 cells and 1100 ng • day-1 • 10-6 cells, respectively) under the control of doxycycline. QXMSC1-IL-2 + IL-3 in combination with allogeneic bone marrow could significantly increase the counts of CD4+ and CD8+ T cell, 1. 72 and 1.27-fold respectively at week 3 compared with TCD-BMT group (P<0.01); make CD4+/CD8+ ratio return to normal level at week 4; enhance splenocytes mitotic response to ConA (P < 0. 01), and accelerate restoration of TCR repertoire diversity in the lethally irradiated mice (P<0.05). Conclusion The gene transduced stromal cell line QXMSC1-IL-2 + IL-3 is able to accelerate T-cell immunity in allo-BMT mice. Chin Med J 2004; 117(8):1223-1227

Background The synthesis of virus-like particles (VLPs) provides an important tool to determine the structural requirements for viral particle assembly and virus-host interactions. Our purpose was to express simultaneously all three structural proteins of hepatitis C virus (HCV) in insect cells to investigate the proteins assembly into VLPs and the immunogenicity of these particles. Methods HCV gene sequences encoding the structural proteins C, E1, and E2 were amplified with PCR, and recombinant baculoviruses were constructed using recombinant DNA techniques. The expression of HCV structural proteins in insect cells was analyzed by immunofluoresceoce and SDS-PAGE. The interaction of expressed structural proteins was investigated by immunoprecipitation and immunoblotting. The VLPs in the insect cells were visualized by electron microscopy (EM). VLPs were then purified by sucrose gradient centrifugation and used to immunize BALB/c mice. Antibodies against HCV were tested for in mouse serum samples by an ELISA assay. Results The recombinant baculoviruses reBV/C and reBV/E1-E2 were constructed successfully. Insect cells co-infected with reBV/C and reBV/E1-E2 expressed HCV C, E1, and E2 proteins with the expected molecular weights of 20kD, 35kD, and 66kD, respectively. The results of immunoprecipitation and immunoblotting assays revealed the coimmunoprecipitation of C, E1, and E2 proteins, indicating association of the three structural proteins. Electron microscopy of insect cells co-infected with reBV/C and reBV/E1-E2 demonstrated spherical particles (40 to 60 nm in diameter) similar to the HCV virions from serum samples or hepatic tissue samples of HCV infected humans. The VLPs were partially purified. Antibodies to HCV were detectable in the serum of mice immunized with VLPs. Conclusion HCV structural proteins simultaneously expressed in insect cells can interact with each other and assemble into HCV-like particles, which are shown to be immunogenic in mice. Chin Med J 2004; 117(8):1217-1222

Background Peritoneal dissemination is the most common pattern of metastasis in advanced gastric carcinoma with serosal invasion. In the present study, we reported the clinical relevance of a new diagnostic method involving RT-PCR, using survivin as the target gene, for the detection of free cancer cells in peritoneal washes. Methods Intraoperative peritoneal washes were obtained from 48 patients who underwent surgery for gastric cancer. RT-PCR analysis with primers specific for survivin and conventional cytological examinations were both performed. Results Survivin mRNA was not detected in any peritoneal wash samples from patients with benign disease, but was detected in 28 of 48 samples taken from patients with gastric cancer and in all metastastic nodules. Survivin expression in the peritoneal cavity significantly correlated with depth of cancer invasion, lymph node metastasis, and TNM stage. There were 92% of clinically evident peritoneal metastasis cases showed detectable survivin expression. The combination of survivin RT-PCR and cytological examination yielded positive results in 66. 7% (32/48) of patients with gastric cancer, much higher than the results produced by cytological method alone. Conclusions Survivin mRNA detected in peritoneal lavage fluid might indicate the presence of free cancer cells in the peritoneal cavity. The high sensitivity of the RT-PCR-based survivin assay suggests that survivin serves as a molecular marker for detecting peritoneal micrometastasis. Its ubiquitous expression in peritoneal cancer cells and metastatic nodules also suggests a promising future therapeutic strategy based on survivin inhibition for cases of gastric cancer involving peritoneal metastasis. Chin Med J 2004; 117(8):1210-1217

Background This study was designed to investigate the hot spots of microsatellite loss of heterozygosity (LOH) on 9p13-23 in laryngeal squamous cell carcinoma and to find out the correlation between the incidence of microsatellite LOH and the clinicopathological parameters. Methods Tumor tissues were obtained from paraffin embedded sections with microdissection. Genomic DNA was extracted from tumor tissues and peripheral blood lymphocytes with the phenolchloroform. Polymerase chain reaction (PGR) amplification and denaturing gel electrophoresis were carried out in a set of 42 squamous cell carcinoma (SCC) of larynx and corresponding peripheral blood lymphocytes using 13 highly polymorphic microsatellite markers on 9p13-23. The correlation was analyzed between microsatellite LOH at the high frequency on 9p13-23 and clinicopathological parameters in the patients with squamous cell carcinoma of larynx. Results Of the 42 laryngeal cancers, 41 (97. 6%) showed LOH in at least one of the microsatellite markers tested on 9p13-23. The most frequently deleted marker was D9S162 in 17 of the 19 (89. 5%) informative samples. The marker D9S171, which is located on 9p21, had LOH detected in 12 of the 15 informative cases (80. 0%). LOH at the D9S1748 marker (closest to the p16 gene locus) was detected in 18 of the 36 informative cases (50. 0%). Allelic deletion mapping revealed two minimal regions of LOH encompassing markers D9S161-D9S171 on 9p21 and IFNA-D9S162 on 9p22-23. Multiple LOH (≥4) on 9p21-23 was found more frequently in the patients under 60 years, with supraglottic SCC or cervical lymph node metastasis than those over 60 years, with glottic SCC or without cervical lymph node metastasis (P < 0. 01 or 0. 01, 0. 05, respectively). On the contrary, there was no correlation between T stages or pathologic classification and the frequency of LOH on 9p21-23 in 42 SCC of Larynx. Conclusions These findings imply the presence of at least two putative tumor suppressor genes on 9p13-23 in laryngeal SCC. Multiple genetic alterations are probably implicated in supraglottic SCC with cervical lymph node metastasis in younger patients. Chin Med J 2004; 117(8):1204-1209

Background Silicon gel is unfavourable for cell attachment and growth. This study was to study if pretreating the surface of silicon gel with chemical agents affects the proliferation of epithelial cells. Methods Silicon gel was made and treated with either mixed acid solution (containing 232 g/dm3 of H2SO4 and 8 g/dm3 of K2Cr207) or 300 cm3/dm3 peroxide for 5, 10, and 15 minutes or 10, 15, and 20 minutes, respectively. The cultured corneal epithelial cells were seeded onto those silicon gels and kept for 13 days. Immunohistochemical investigations were then carried out for integrin (alpha 6 or beta 4) and actin. Results Growth of the epithelial cells in silicon gels treated with mixed acid solution for 10 minutes and 15 minutes was much significant than that in the untreated gels. After a 12-hour culture, a small number of corneal epithelial cells were proliferated on the surface of the silicon gels that had been treated with peroxide for 15 minutes. After a 3-day culture, those cells were further proliferated and fused together. The corneal epithelial cells did not grow well in the silicon gels treated with peroxide for 10 or 20 minutes. Immunostaining revealed the expression of actin and integrin alpha 6 or beta 4 on the silicon gels that were treated with mixed acid solution for 10 minutes or peroxide for 15 minutes. Conclusion Silicon gels treated either with mixed acid solution for 10 or 15 minutes or with peroxide for 15 minutes improves cell proliferation. Chin Med J 2004; 117(8):1200-1203

Background Matrix metalloproteinases (MMPs) are the major regulators of collagen degradation involved in the pathogenesis of several diseases of the heart. The purpose of this study was to investigate the dynamic changes in myocardial MMP activity in mice with viral myocarditis (VM), the relationship between MMP activity and both cardiac function and the quantity of myocardial collagen, and the role MMPs playing in the pathological lesions of VM. Methods Sixty-five six-week-old male DBA/2 mice were divided into two groups. Mice in the infected group (n = 50) were inoculated intraperitoneally with 0. 14 ml of Coxsackievirus B3 (CVB3, Nancy strain). Control mice (n =15) were inoculated intraperitoneally with 0. 14 ml of Eagle's medium. Eight infected mice and three control mice were sacrificed on each of days 3, 7, 10, 21 and 30 after inoculation. MMP activity was measured on an SDS-PAGE substrate gel embedded with type I gelatin (zymography). Echocardiographic studies were performed under anesthesia with 3%chloralhydrate administered intraperitoneally (0. 01 ml/g - 0. 015 ml/g). Cardiac systolic function indices, such as peak velocity of the aorta (Vp), flow velocity integral of the aorta (Vi), ejection fraction (EF), and fractional shortening (FS) were determined by echocardiography. Histological cross sections of the hearts were stained with hematoxylin-eosin and myocardial histopathological scores were determined under an optical microscope. The amount of myocardial collagen was measured by means of hydroxyproline quantification. Results In virus-infected mice, both MMP-2 and MMP-9 activities were significantly higher than in control mice, reaching a peak on day 10 (P <0. 01). On day 10, cardiac systolic function indices (EF, FS, Vp, and Vi) were all significantly lower compared both to other stages following viral inoculation and to the control group (P<0. 05). In the acute stage, the amount of myocardial collagen in mice with VM was not significantly different from normal control mice (P > 0. 05). However, the amount of myocardial collagen in infected mice at the recovery stage (on days 21 and 30) was significantly greater than those of the control mice. MMP-2 and MMP-9 activities positively correlated with myocardial histopathological scores (r = 0. 801, 0. 821, P < 0. 01) and negatively correlated with Vp(r = -0. 649, -0.683, P<0.01) and Vi (r = -0. 711, -0. 755, P < 0. 01). However, Vp negatively correlated with myocardial histopathological scores (r = -0. 756, P<0. 01). Conclusions In mice with VM, the activities of myocardial MMP-2 and MMP-9 increase significantly during the acute stage, and the total quantity of myocardial collagen increases by the time of recovery. These changes are associated with myocardial interstition remodeling and cardiac dysfunction. MMP activity is an important reference marker for myocardial pathological lesions and can be used to evaluate the severity of myocardial interstitial damage and cardiac dysfunction. Chin Med J 2004; 117(8):1195-1199