Volume 114 · Issue 02 · 2001

Objective In an earlier interim report of the Chinese Cardiac Study (CCS-1) trial, 15 000 patients up to 36hours after the onset of suspected acute myocardial infarction (AMI) were randomized to receive either oral captopril or matching placebo for one month. Results showed that captopril was associated with a non¬significant reduction in 4-week mortality (681 [9.1 %] captopril-allocated vs 730 [9.7%] placebo-allocated deaths; 2 P=0.19), but the long-term effects remained uncertain. The present study reports on the long-term effect of early captopril treatment on mortality and other major events in AMI patients of the earlier CCS-1 trial. Methods Long-term follow-up was carried out in those hospitals which had recruited more than 20 cases in the CCS-1 trial. 8000 patients with MI were thus selected for long-term follow-up. Data on 6749 patients(84.4%) were available. Results Patient characteristics were comparable between the treatment group (n=3391) and the placebo group (n=3358). Average follow-up time was 23 . 4 ± 16 . 9 months; average age was 63 . 6 ± 10 . 6 years, and 76.2%were male. At the end of the follow-up time, cardiac function of NYHA Ⅲ-Ⅳ was 9.0%in the treatment group and 9.8%in the placebo group; the reinfarction rate was 5.6%vs. 6.0%; total cardiovascular events were 32.9%vs. 34.3% . Total mortality was 11 .9%(n=404) vs 13.8%(n=463), with a 13.8%reduction in the captopril group (P=0.03). Cardiovascular mortality was 10.0%vs. 11 .8%(P=0.01), death due to heart failure was 4.1% vs. 5.5%(P=0.01). From the above results, it is estimated that early treatment with captopril can save 19 lives per 1000 patients treated;patients with systolic blood pressure (SBP)≥100 mm Hg at entry would have a long-term mortality 12.4%in the treatment group vs. 13.8%in the placebo group (P=0.04) and patients with a heart rate (HR)≥60/minute at entry would have a long term mortality 12.0%in captopril groups vs. 14.5%in the placebo group (P=0.01). Conclusion Early treatment with captopril during AMI for 4 weeks can significantly reduce long-term total mortality. Chin Med J 2001; 114(2): 115-118

Objective To investigate the role of Astragali and Angelica (A&A) of Chinese herbs in acute renal ischemia/reperfusion injury, and the related intracellular signal transduction mechanism. Methods Acute ischemic renal injury in rats was induced by clamping in renal pedicel for 45 minutes. Rats in therapy group were given a single dose (2 ml/day) of A&A for 3 days before clamping, and then continued for another 3 days. Forty-five minutes after clamping and at different reperfusion time, serum creatinine (Scr) and renal pathological changes were taken and compared in both groups. The proliferating cell nuclear antigen (PCNA) positive cells were detected by immunohistochemistry. Extracelluar regulating kinase (ERK) and c-Jun N-terminal kinase (JNK) activity was assayed by specific substrate phosphorylation with immunoprecipitation. Results At the 24th hour of reperfusion, Scr was lower in A&A group than that in the control. Much less necrotic tubular cells, casts, and more PCNA-positive cells were found in A&A group. ERK activity decreased after clamping, and recovered at 5 minutes of reperfusion. There was no difference between the two groups. JNK activity did not change after ischemia, but increased at 5 minutes and peaked at 20 minutes of reperfusion. JNK activity was significantly higher in A&A group than that in the control group. Conclusion A&A protected kidney against ischemic insult and accelerated both functional and histological recovery after acute renal ischemia/reperfusion injury, which may associate with the change of JNK signaling pathway. Chin Med J 2001; 114(2): 119-123

Objective To construct a λgt11 cDNA expression library of Echinococcus multilocularis protoscolex isolated in China. Methods Echinococcus multilocularis protoscolex mRNA was extracted using a Quickprep MicromRNA purification kit based on combining of the disruptive and protective properties of guanidinium thiocyanate(GTC)with the speed and selectivity of oligo(dT)-cellulose chromatography in a spum-column with some modification. Purified mRNA(1. 8 μg)was submitted to reverse transcription using random hexamers[pd(N6)]. The double-strand blunt-ended cDNAs were ligated with an EcoRI/Notl adaptor to form a cohesive EcoRI end. Subsequently the synthesized cDNA was inserted into vector λgt11 EcoRI arms. After being packaged in vitro, λgt11 was put to an infectious bacteria Echinococcus coli(E. coli)strain Y1090; the recombinants were screened by color selection. PCR amplification was performed to evaluate the size of insertion DNA fragments. Results The recombinant ratio was nearly 100%and approximately 1 x 106 clones could be derived from this λgt11 cDNA library. PCR results indicated that the insertion DNAs were about 1. 48 kb. Conclusions A λgt11 cDNA expression library consisting of a million recombinant clones has been constructed from Echinococcus multicularis protoscolex mRNA. Further studies on this library are deserved. Chin Med J 2001; 114(2): 124-127

Objective To clarify the role of sexual related Y (SRY) gene detection in the diagnosis of gonadal dysgenesis. Methods Sixteen cases of gonadal dysgenesis were included in this study: 5 with androgen insensitivity syndrome, 1 with 17-α-hydroxylase deficiency, 4 with true hermaphrodite, 2 with 45, X/46, XY gonadal dysgenesis, 1 with 45, X gonadal dysgenesis, 1 with XY pure gonadal dysgenesis, 1 with testicular regression, and 1 XY female who gave birth to a normal baby. SRY gene was detected by using polymerase chain reaction (PCR) in blood and gonad samples and by direct sequencing of the SRY motif. Results Among the 16 cases, 15 were blood SRY positive, among which 13 (86.7%) showed the presence of testicular tissue, and 2 showed ovaries without testicular tissue. One SRY negative case showed the presence of testicular tissue. In 3 cases, SRY detection in gonadal tissue correlated with pathological findings but not with blood karyotype. The correlation between peripheral blood SRY and the pathology of the gonads was 81.25%and the correlation between the presence of peripheral blood Y chromosome and pathology of the gonads was 68.75%. Sequencing of the SRY motif in an XY female who gave birth to a normal baby showed no mutation. Conclusions SRY detection is more sensitive and specific than blood karyotype in the prediction of the presence of testicular tissue. Peripheral blood karyotype does not necessarily reflect gonadal type. There may be testicular related factors other than the SRY gene. Chin Med J 2001; 114(2): 128-131

Objectives To investigate the prevalence of sinonasal lymphoepithelial carcinoma (SNLEC) in Guangzhou, a high incidence area of nasopharyngeal carcinoma (NPC), and to detect whether it is associated with Epstein-Barr virus (EBV) infection. Methods Twenty confirmed SNLEC specimens were collected from all of the sinonasal carcinoma biopsies performed in the 8 years 1989 - 1996 at the Sun Yat-sen University of Medical Sciences. EBV encoded early RNAs were detected by use of in-situ hybridization. A variety of antigens, including the EBV nuclear antigen 1, latent membrane protein 1, BZLF1 protein, diffuse early antigen, viral capsid antigen and membrane antigen, were detected using immunohistochemistry. Additionally, 36 NPC specimens were used for comparison. Results Twenty SNLECs were identified. Seventeen SNLECs were developed in the nasal cavity, and 3in the maxillary sinus. The mean age (46.25 y), male to female ratio (3:1), histopathology and lymphoinfiltration of the 20 SNLECs were identical with those of the 36 NPCs. Thirteen (65.0%) of the 20SNLECs showed an expansive growth pattern, while 27 (75.0%) of the 36 NPCs showed an infiltrating or mixed growth pattern. The majority of cancer cells in all of the 20 SNLECs showed EBV encoded early RNAs. The EBV nuclear antigen 1 expression of SNLEC was less intensive than that of NPC. The expression rate of latent membrane protein 1 for SNLEC (3/20, 15%) was lower than that for NPC (19/36,52.8%). The expression rates of BZLF1 protein (2/20, 10.0%), diffuse early antigen (19/20, 95.0%),viral capsid antigen (15/20, 75.0%), and membrane antigen (13/20, 65.0%) for SNLEC were higher than those (0/36, 0.0%; 31/36, 86.0%; 18/36, 50%; and 14/36, 38.9%) for NPC. Conclusions SNLEC is not uncommon in Guangzhou. This tumour is also consistently associated with EBV infection like NPC. As compared to NPC, the EBV harbored in SNLECs seems to express the EBV nuclear antigen 1 weakly and has a lower expression rate of latent membrane protein 1 as well as higher expression rates of EBV lytic products . Chin Med J 2001; 114(2): 132-136

Objective To study the incidence of malignant change, diagnosis and management of mature cystic teratomas in postmenopausal women. Methods Twenty cases of mature cystic teratoma in postmenopausal women admitted to our hospital between January 1977 and January 1997 was retrospectively reviewed and evaluated. Results The number of postmenopausal patients with mature cystic teratoma (20) accounted for 7.6%of the total number of patients with benign ovarian teratomas (263). There were 3 cases of malignant change,which were squamous carcinoma, carcinosarcoma, and digestive gland epithelial carcinoma. The incidence of malignant change was 15%. Conclusion In postmenopausal women, mature ovarian cystic teratoma should be treated as lowly malignant and should be paid much attention. Chin Med J 2001; 114(2): 137-138

Objective To elucidate the mechanism of interferon-gamma (IFN-γ) to inhibit the restenosis after successful percutaneous transluminal angioplasty (PTA). Methods A rabbit vascular restenotic model was constructed and the proliferation of intimal smooth muscle cells (SMCs) were observed by monitoring their expression of proliferating cell nuclear antigen (PCNA) and platelet-derived growth factor β chain mRNA (PDGF-β mRNA) at the indicated time points. Results IFN-γ could significantly inhibit the expression of PCNA by intimal SMCs one week after denudation, when counting 200 intimal cells for PCNA-positive reactions with an inhibitory rate of 88.50%(P <0. 001) . IFN-γ could downregulate in situ expression of PDGF-β mRNA by these cells as we calculated the average number of PDGF-β mRNA positive cells per square millimetre area at x 400magnification with reduced rates of 86.85%in 1 week group (P <0.001), of 93.66%in 2 week group(P <0.001) and of 52.92%in 4 week group (0.02 <P<0.05), respectively. Conclusions The local production of PDGF-β by vascular intimal SMCs via an autocrine mechanism may be responsible for continuous proliferation of these cells and the formation of neointima after injury. This could be inhibited by IFN-y through downregulating the expression of PDGF-β mRNA. These results provide an in vivo basis for IFN-γ to be used clinically for the management of restenosis after percutaneous transluminal angioplasty. Chin Med J 2001; 114(2): 139-142

Objective To investigate the cold preservation effect on rat livers of a modified storage method with self-made HYD solution. Methods The vascular bed of rat livers was expanded with an additional 20 to 40 ml self-made HYD solution/100 g liver. After resection of the liver, the extra HYD solution (expressed as %liver weight) was entrapped via portal infusion by tying off the supra- and infra-hepatic inferior vena cava. Forty rats were randomly divided into four groups including control group with conventional storage method, and 20%, 30%and 40%groups according to the amount of extra HYD solution. We compared the preservation effect of the modified storage method with that of the conventional storage method using an isolated perfused rat liver model. Results Bile production and all the indices of hepatic microcirculation including portal perfusion pressure,endothelin-1 in the effluent, trypan blue distribution time and histology were significantly superior in the modified method groups compared to those in the control group (P <0.05). The contents of dihydroxybenzoic acid (DHBA) in the modified method groups were significantly lower than those in the control group (P <0.05). Liver enzymes activities in the 30%group were markedly lower than those in the control group (P <0.05). The preservation effect on rat liver in the 30%group was the best among the modified method groups. Conclusion The modified cold storage method is effective and may have potential for clinical application in liver preservation. Chin Med J 2001; 114(2): 143-146

Objectives To explore whether HSV-TK (herpes simplex virus thymidine kinase) and GM-CSF(granulocyte-macrophage colony-stimulating factor) genes could be linked by internal ribosome entry site(IRES) in one retroviral vector and expressed by ovarian cancer cells following transfection, and to observe the characteristics of the transduced cells. Methods Retroviral vector pLGM-I-TK was constructed by linking the HSV-TK gene and GM-CSF gene with the IRES sequence. By using the "ping-pong" technique, pLGM-I-TK was transfected into the packaging cell line, PA317, to produce a PA317/TK-GM cell line. Using the resulting viral supernatant to infect the ovarian cancer cell line SKOV3, PCR and RT-PCR were used to explore the integration and transcription of HSV-TK and GM-CSF genes. The cytotoxicity of GCV (gancyclovir) on SKOV3/TK-GM was determined by MTT assay and the bystander effect of the HSV-TK/GCV system was also assessed. ELISA was used to measure the expression of GM-CSF by the transgene cells. Results The bicistronic retroviral vector constructed could be successfully transduced into PA317 and the titer of the retroviral vector was about 8.6 x 105 cfu/ml. PCR and RT-PCR demonstrated the successful integration and transcription of HSV-TK and GM-CSF genes transduced into the SKOV3 cell. SKOV3/TK-GM cells could be killed by GCV, and the IC50 was 0.7 μg/ml. The bystander effect was demonstrated. The expression level of GM-CSF in SKOV3/TK-GM was 60.4 ng· ml-1·106 cells-1·2 days-1. Conclusion The IRES sequence can be used to construct retroviral vectors to facilitate co-transfection of two genes. SKOV3/TK-GM cells can simultaneously express the HSV-TK and GM-CSF genes with biological activities which could be useful for enhancing the function of immune cells on the basis of suicide gene therapy. Chin Med J 2001; 114(2): 147-151

Objective To investigate the expression of β-catenin and its mRNA in renal cell carcinoma. Methods Twenty-six cases with renal cell carcinoma (RCC) were studied by immunohistochemistry,Western blot and RT-PCR. Results We found the expression of β-catenis is higher in cancer tissues than in normal kidney tissues and the level of β-catenin is associated with the tumor stage. Its expression in tumor of pT3 and pT4 is obviously higher than pT1 and pT2 (P <0.01). That is to say, there was an overexpression of β-catenin protein in RCC and its level was related to the tumor stage, but the expression of β-catenin mRNA had no difference between tumor tissue and normal tissue. Conclusion β-catenin may be related to the occurrence and progress of RCC. Chin Med J 2001; 114(2): 152-154

Objective To examine the relationship between spontaneous abortion and chromosomal abnormalities. Methods Couples who had one or more consecutive spontaneous abortions and had normal genitals were enrolled for cytogenetic karyotype analysis. Results In the 61 couples, the detected incidence was 11.5%, with five Robertsonian translocations,one reciprocal translocation, and one pericentric inversion of chromosome 7. Conclusion Chromosomal abnormalities may play an important role in fetal wastage. Chin Med J 2001; 114(2): 200-201