Volume 117  ·   Issue 01  ·  2004

Background To investigate the effects of DNA methylation on the expression of tumor-associated genes and the cell cycle in human gastric cancer cells. Methods Two gastric cancer cell lines (MKN-45 and HGC-27) were treated with DNA methyltransferase (DNMT) inhibitor, 5-aza-2' -deoxycytidine (5-aza-dC). The expressions of p16INK4A, p21WAF1, p53, p73, c-Ha-ras and c-myc genes mRNA were detected by using reverse transcription PCR (RT-PCR). DNA methylation status of p16INK4A gene promoter was assayed by bisulfite modification and sequencing. The cell cycle was analyzed by using flow cytometry (FCM). Results 5-aza-dC induced the demethylation of p16INK4A gene promoter. The expression of p16INK4A mRNA was obviously up-regulated by treatment with 10 μmol/L (MKN-45 cells) or 5 μmol/L (HGC-27cells) of 5-aza-dC for 24 hours. However, 5-aza-dC treatment failed to regulate the expressions of p21WAF1, p53, p73, c-Ha-ras and c-myc genes in MKN-45 and HGC-27 cells. Furthermore, 5-aza-dC induced the cell cycle arrest in G1 phase in HGC-27 cell, but not in MKN-45 cell. Conclusions DNA methylation regulates the transcription of p16INK4A but not p21WAF1 and proto-oncogenes in human gastric cancer cell lines MKN-45 and HGC-27. Chin Med J 2004; 117(1): 99-103

Background Osteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma. Methods Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type I collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed. Results Observation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type I collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicel of osteochondroma or outside osteochondroma were endothelial-lined. Conclusion These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry. Chin Med J 2004; 117(1): 94-98

Background The role of the Gaq/11 -mediated signal transduction pathway in angiotensin II (Ang II) induced cardiac hypertrophy remains unclear. This study was to investigate the role of the Gaq/11signal transduction pathway in the development of cardiac hypertrophy in 2K1C hypertensive rats and in cultured neonatal rat ventricular myocytes (NRVMs) and to elucidate the effects of the pathway on Ang II induced cardiac hypertrophy. Methods Renal hypertension was induced in 2K1C hypertensive rats by placing a silver clip around the left renal artery. At 8 weeks after operation, the systolic blood pressure, the ratio of left ventricular weight to body weight (LV/BW), and the concentration of Ang II in the heart were measured. The protein levels of Gaq/11 and extracellular signal-regulated kinase 1/2 (ERK1/2) were assayed by Western blot analysis, and the activity of phospholipase C (PLC) in the myocardium was detected using [3H]-PIP2 as a substrate. Changes in [3H]-leucine incorporation and in the protein levels of the signal molecules Gaq/11, PLCβ3, and ERK1/2 were measured after NRVMs were stimulated with 10-7mol/L Ang II. Results The protein levels of Gaq/11 and ERK1/2 in the hearts of 2K1C rats increased by 35. 8%and 31. 9%, respectively, compared with the sham group. The PLC activity in the 2K1C group was also significantly increased (P <0. 05). The levels of Gaq/11, PLCβ3, and ERK1/2 increased significantly after NRVMs were stimulated by Ang II. The upregulation of Gaq/11, PLCβ3 and ERK1/2in NRVMs occurred prior to [3H]-leucine incorporation increases, and could be inhibited with losartan. Conclusion Ang II can initiate cardiac hypertrophy and upregulate signal molecules in the Gaq/11 -mediated signal transduction pathway, such as Gaq/11, PLCβ3 and ERK1/2, at both tissue and cellular levels. Chin Med J 2004; 117(1): 88-93

Background The development of new adjuvants for human use has been the focus of attention. This study's aim is to explore the possibility of using nanoparticle Ca nanoparticles (CA) as a vaccine adjuvant of anti-idiotypic antibody NP30 against schistosomiasis and its protective mechanisms. Methods Nanoparticle CA-NP30 conjugate (CA-NP30) was fabricated. BALB/c mice were immunized actively with CA-NP30 to evaluate its effects of protective immunity on mice. The serum levels of specific IgG, IgG1 and IgG2a antibodies against NP30 and the concentrations of IFN-γ and IL-4 in supernatant of splenocytes were determined via ELISA. Results Nanoparticle CA could enhance significantly the protective immunity of NP30 against infection of Schistosoma japonicum and the worm reduction rose from 36. 0%(NP30 alone)to 52. 6%. The serum levels of specific IgG, IgG1 and IgG2a antibodies against NP30 increased remarkably, as compared with those of the group immunized with NP30 alone. The concentration of IFN-γ in supernatant of splenocyte was drastically elevated [the groups immunized with CA-NP30 and NP30 alone were (493. 80 ±400.74) pg/ml and (39. 03 ±39.58) pg/ml, respectively], but the concentration of IL-4 showed no significant difference from that of NP30 alone [(27. 94 ±9. 84) pg/ml vs (27. 28 ±14. 44) pg/ml]. Conclusions Nanoparticle CA could act as a vaccine adjuvant of anti-idiotypic antibody NP30 against schistosomiasis. The mechanism could be that CA-NP30 enhances humoral and cellular immune responses in mice. Chin Med J 2004; 117(1): 83-87

Background It has been known that intra-cellualr immunity is important for defense against viral infections and this function lies with interferon gamma (INF-γ). Here we evaluated the role of IFN-γsystem in the pathogenesis of chronic hepatitis C (CHC). Methods The levels of interferon gamma receptor alpha (IFNGRα) on the peripheral lymphocyte membrane were assayed with flow cytometry. The plasma concentrations of the cytokines IFN-γ and IL-10 in CHC patients and normal controls were assayed by enzume-linked-immunosorbent assay(ELISA). The samples were collected randomly from Xinjiang Autonomous Region, Zhejiang and the northern regions of Jiangsu Province in China. Results The levels of IFNGRa in CHC patients were significantly lower than that of normal controls(NO, especially among patients during the stable stage (P<0. 001), whereas there were no significant differences between CHC in active and stable stages. Among the patients of the three regions, there were no significant differences between patients from Xinjiang and Zhejiang provinces,but both had statistically significant difference compared with the patients from Jiangsu Province (P <0.001). Plasma IFN-y and IL-10 concentrations in CHC patients decreased significantly, IFN-y in particular, but there were no significant differences in these levels between various stages of the disease. The IFN-γ/IL-10 (Th1/Th2) ratio in patients was reversed. Conclusion There may be defects in the IFN-γ system in chronic HCV infected subjects and a low immune response, which may play an important role in the persistence of HCV infection. Chin Med J 2004; 117(1): 79-82

Background Uterine arterial embolization (UAE) is a safe and effective therapy for symptomatic uterine leiomyoma. This study was to assess the effectiveness and the feasibility of pingyangmycin-lipiodol emulsion (PLE) for the management of symptomatic uterine leiomyoma. Methods One hundred consecutive patients (aged 21 - 53 years, with 38 in average) with symptomatic uterine leiomyoma underwent superselective UAE with PLE. Clinical symptoms of the patients (including menorrhagia, bulk-related symptoms, and postprocedure-related abdominal pain)and the changes in uterine volume and tumor size after the embolization were analyzed. The patients were followed up for 8 -21 months (mean, 15 months). Results Ninety-nine patients (99%, 99/100) were interviewed in their first menses circle after embolization, showing improvements in their abnormal bleeding and bulk-related symptoms to some extent. Imagiological results during follow-up showed a mean of 48%reduction in uterine volume at 6months and a mean of 75%reduction in tumor size at 9 months. Eighty-three percent of the patients reported complete resolution of postprocedure pain within 7 days. Conclusions PLE is effective in the management of uterine leiomyoma, having superiority in alleviating postprocedure-related pain. Chin Med J 2004; 117(1): 75-78

Background Coagulation factor VII (F Ⅶ) levels in plasma are usually related to ischemic heart disease (IHD) and cerebral infarction shares many of the risk factors related to IHD. Is there any relationship between factor VII and cerebral infarction? We investigated the relationship between F VII and acute cerebral infarction and reported genotype frequencies and allelic frequencies of F VII gene polymorphisms in the Chinese Han population. Methods We recruited 62 patients with acute cerebral infarction confirmed by magnetic resonance imaging (MRI) from Ruijin Hospital, and 149 age-matched patients clinically free of vascular disease to act as controls. All of them were unrelated, and were from the Chinese Han population. F VII coagulant activity (FVIIc) was determined using an clotting assay, activated FVII (FVIIa) and FVII Ag were assayed using enzyme immunoassay kits. The FVII gene polymorphisms to be detected included-401 G/T, -402G/A, 5' F7A1/A2, IVS7 and R353Q. 5' F7 and IVS7 were revealed by means of a PCR and direct agarose gel electrophoresis. The rest were examined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results The results showed that FVIIc, FVIlAg and FVIIa were higher in the acute cerebral infarction group than in the control group (P <0. 01, P <0. 05, P <0. 05, respectively). There were no significant differences in the genotype frequencies of F VII gene polymorphisms between the two groups. The allelic frequencies in the Chinese Han population were as follows: - 401 G/T(96. 64/3. 36), -402G/A (52. 01/47. 99), 5' F7A1/A2(96. 64/3. 36), IVS7 H5/H6/H7/H8 (0. 34/52. 35/46. 98/0. 34) and R353Q (95. 64/4. 36) . There were significant differences (P <0. 01, P <0. 001, P <0.001, P <0. 001, P <0. 001, respectively) in these allelic frequencies between the Chinese Han and European populations. Conclusions The results indicate that increased plasma FVII levels may contribute to thrombosis in cerebral infarction. And there was no significant difference in genotype frequencies of these five FVII gene polymorphisms between the acute cerebral infarction and control groups. Moreover, these results showed that the frequencies of protective allele, including -401T, 5' F7 A2 and 353Q were lower, but that -402A, which was previously found to be associated with increased plasma F VII levels, is higher in Chinese Han population. Chin Med J 2004; 117(1): 71-74

Background There have been few studies to evaluate the effects of helical CT on bladder tumor. This study was to evaluate the clinical applications of helical CT dynamic contrast-enhanced axial imaging, multiplanar reformation (MPR), three-dimensional (3D) reconstruction and virtual cystoscopy (CTVC) in bladder tumors. Methods The precontrast and four-phase postcontrast helical CT scans were performed in 42patients with bladder tumors confirmed by conventional cystoscopy and pathology. MPR, 3D and CTVC images were generated from the volumetric data of the excretory phase. The results were then compared with the findings of conventional cystoscopy and surgery in a double-blinded mode. Results The sensitivity of the axial, 3D and CTVC images in detecting the bladder tumors were 90. 8%, 76. 9%and 95. 4%respectively. The dynamic contrast-enhanced axial images could provide excellent intramural and extravesical information, and the accuracy in preoperative tumor staging was 87. 7%. MPR could directly demonstrate the origin and extravesical invasions of the tumors and their relation to the ureter. 3D and CTVC images were useful for displaying the surface morphology of the tumor and the relationship between the tumor and the ureteric orifices, whereas CTVC could depict the tumors smaller than 5 mm that were not seen on the axial images. Conclusions The combination of axial, MPR, 3D and CTVC images with helical CT can provide comprehensive information on bladder tumor. Chin Med J 2004; 117(1): 62-66

Background Medically unexplained dyspnea occurs commonly in medical settings and remains poorly understood. This study was conducted to investigate the psychophysiological characteristics of medically unexplained dyspnea and the efficacy of breathing retraining for these patients. Methods A group of patients with medically unexplained dyspnea were compared to patients with a variety of organic lung diseases and healthy subjects. In another group of patients, the influence of breathing therapy on complaints, anxiety, and breath-holding was evaluated for an average of 1. 5years. Results Patients with medically unexplained dyspnea reported more intense dyspnea than patients with a variety of organic lung diseases. Additionally, they were anxious and presented a broad range of symptoms in daily life and under challenge, for instance voluntary hyperventilation. More than one third of them qualified for panic disorder. They had shorter breath-holding time at rest, less increase in breath-holding time and higher chances of showing a "paradoxical" decrease of breath-holding time after hyperventilation. A combination of Pa02, forced expiratory volume in one second (FEV1), and anxiety measures distinguished them from organic dyspnea. Breathing retraining profoundly improved their symptoms and decreased the level of state and trait anxiety. Moreover, they better tolerated the voluntary hyperventilation and the symptoms induced were also markedly decreased after therapy. Breath-holding time was prolonged and PetCO2 in a representative group of patients increased. Conclusions Patients with medically unexplained dyspnea appear to have the feature of a "psychosomatic" patient: an anxious patient with a wide variety of symptoms of different organ systems that do not have an organic basis. They can be distinguished from organic dyspnea using a small set of physiological and psychological measures. Breathing retraining turns out to be an effective therapy for those "difficult to treat patients". Chin Med J 2004; 117(1): 6-13

Background In general vagus nerve stimulation (VNS) can serve as an adjunctive treatment for patients with refractory partial -onset seizures. And we evaluated the long-term efficacy and safety of VNS in a group of Chinese patients with refratory epilepsy. Methods Of 127 patients with refractory epilepsy, 13 patients who were not eligible for surgical intervention were implanted with the Cyberonics VNS system. Seizure frequency, physical examination and side effects profile were recorded at follow-up visits for a minimum of 18 months. Results Mean duration of treatment was 47. 4 months, and the longest follow-up period was 71months. Mean baseline seizure frequency was 26. 6 seizures per month. The mean percentage reductions in convulsions were 33. 2%, 47. 1% and 40. 0% at 6, 12 and 18 months, respectively. One patient became seizure free, and six (46%) had 50%or more reduction in seizure frequency. Response was poor (<20%reduction) in five patients (39%). Side effects were uncommon. Conclusions The effectiveness of VNS was sustained and was well tolerated but benefited only a sub-group of patients with intractable convulsions. Chin Med J 2004; 117(1): 58-61

Objective To summarize current understanding of the roles of anti-inflammatory and proinflammatory mechanisms in the development of atherosclerosis and acute coronary syndrome and to postulate the novel concept of inflammation stress as the most important factor triggering acute coronary syndrome. Moreover, markers of inflammation stress and ways to block involved pathways are elucidated. Data sources A literature search (MEDLINE 1997 to 2002) was performed using the key words "inflammation and cardiovascular disease." Relevant book chapters were also reviewed. Study selection Well-controlled, prospective landmark studies and review articles on inflammation and acute coronary syndrome were selected. Data extraction Data and conclusions from the selected articles providing solid evidence to elucidate the mechanisms of inflammation and acute coronary syndrome were extracted and interpreted in the light of our own clinical and basic research. Data synthesis Inflammation is closely linked to atherosclerosis and acute coronary syndrome. Chronic and long-lasting inflammation stress, present both systemically or in the vascular walls, can trigger acute coronary syndrome. Conclusions Inflammation stress plays an important role in the process of acute coronary syndrome. Drugs which can modulate the balance of pro- and anti-inflammatory processes and attenuate inflammation stress, such as angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers, statins, and cytokine antagonists may play active roles in the prevention and treatment of acute coronary syndrome when used in addition to conventional therapies (glycoprotein II b/ III a receptor antagonists, mechanical intervention strategies, etc). Chin Med J 2004; 117(1): 133-139