2000年 · 第113卷第05期

Objective To investigate the influence on plasma lipid levels of alcohol and a common polymorphism in the human apolipoprotein AI gene promoter at a position 75 bp upstream of the transcription start site. Methods For this study, 742 healthy Yi and Han subjects all above 15 years old formed the total population which was divided into three groups: the Yi-farmer group, the Yi-emigrant group and the Han-resident group. All estimates of plasma lipids and apolipoproteins were performed using an auto-analyzer. Genetic DNA was prepared from the blood clots using the Triton X-100 lysis technique. Amplification of a 432 bp fragment of the apoAl gene promoter was performed using PCR followed by restriction digestion, electrophoresis and identification of the genotypes involved. Results The samples were divided on the basis of alcohol consumption: non-drinkers, 1 - 25 g/day, 26 -75 g/day and > 75 g/day. Comparing the four alcohol consumption groups, plasma HDLC and apoAl levels were increased as the alcohol consumption increased with no evidence of threshold effects in the Yi-farmers and the Han people groups. A similar association was found in the Yi-emigrant group, but was not statistically significant. The frequencies of the A allele in the three populations were similar, and no significant difference of lipid and apolipoprotein levels was found between subjects with and without the A allele in the three populations. But, in Han and Yi-emigrant samples, the drinkers with the GG genotype had higher plasma HDLC and apoAl levels than non-drinkers with the same genotype, while the drinkers with the A allele had lower plasma HDLC and apoAl levels than drinkers without the A allele. Non-drinkers with the A allele had higher levels of apoAl than non-drinkers with GG genotypes. It was estimated that 18% of the variability of plasma apoAl level could be explained by the G to A polymorphism in non-drinkers of Yi-emigrants (F = 8.94, P < 0.01). Conclusions The present data suggest that moderate alcohol consumption and the G to A substitution could lower the risk of coronary heart disease (CHD), but the beneficial effects of one will be negated by the other. Chin Med J 2000; 113(5): 471-474

Objective To further study the anti-metastasis mechanism of laminin-glycopeptides on carcinoma cell proliferation, apoptosis and the secretion of matrix metalloproteinases. Methods Human hepatocellular carcinoma cells in serum free medium were incubated on laminin-coated substrate with or without laminin-glycopeptides at a final concentration of 50 μg/ml. The total number of surviving cells after incubating for the indicated time was assayed by MTT assay. DNA synthesis of the incubated cells was detected by 3H-TdR incorporation. Cell cycle was analysed by FACS. The mitotic index of Giemsa stained cells was assessed. Cell apoptosis was detected by both FACS and an acridine orange staining method. Matrix metalloproteinase secretion was analysed by gelatin zymography. Results The total number of surviving cells incubated on laminin in the absence of laminin-glycopeptides was significantly larger than that in the presence of laminin-glycopeptides. Laminin promoted 3H-TdR incorporation of carcinoma cells, decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase. In contrast, laminin-glycopeptides could inhibit the effect of laminin as shown by 3H-TdR incorporation and cell cycle analysis. The percentage of cells in G2 + M phase and the mitotic index among various groups showed no significant difference. Matrix metalloproteinases secretion from cells treated by laminin-glycopeptides was much less compared to that without the treatment by laminin-glycopeptides. Conclusion Laminin may stimulate cell proliferation, while laminin-glycopeptides could significantly inhibit the effect of laminin by inhibiting DNA synthesis and arresting the carcinoma cell cycle from G1 to S phase. These effects may inhibit not only tumor growth of the primary carcinoma, but also the establishment of metastases at ectopic tissues. Laminin-glycopeptides could also inhibit the secretion of matrix metalloproteinases from carcinoma cells and this may contribute to their decreased invasive and metastatic phenotype. This study further revealed the cellular and molecular mechanism of laminin-glycopeptides on anti-metastasis . Chin Med J 2000; 113(5): 466-470

Objective To investigate the effect of transient ischemia-reperfusion on the retina in rats. Methods Retinal ischemia-reperfusion was induced in rats by increasing the intraocular pressure. After 1 or 5 minutes of ischemia, retinal neuronal cell death at diffesent periods of reperfusion was studied using the TdT-deoxynucleotide terminal nick-end labeling (TUNEL) method and light microscopy. Retinal IL-1β and TNFα were quantified by an enzyme-linked immunosorbent assay (ELISA). Results A few migrating leukocytes were noticed in the retina after transient retinal ischemia-reperfusion. Rare TUNEL-positive (T +) cells were noticed in the outer granular layer or the rod and cone layer, and not in ganglion cell layer in control eyes, but they were significantly increased in the outer granular layer, the inner granular layer, and ganglion cell layer in the eyes treated with 1 or 5 minutes of retinal ischemia-reperfusion (P < 0.05). Retinal IL-1β was significantly increased at 6 hours after reperfusion in the eyes treated with 1 or 5 minutes ischemia over the control eyes (P < 0.05), but retinal TNFα was not significantly increased (P > 0.05). Conclusion Transient retinal ischemia-reperfusion for only 1 or 5 minutes of ischemia can induce the upregulation of retinal IL-1β and apoptosis of retinal neuronal cells. This kind of apoptosis in individual cells, however, was not sufficient to affect the whole retinal function. Chin Med J 2000; 113(5): 461-465

Objective To investigate whether a reporter LacZ gene could be transferred into cultured ocular cells of human eyes in vitro. Methods Fibroblast cells of Tenon's capsule, trabecular meshwork cells, and muscle celms in the ciliary body of human eyes were cultured and the pcDNA3-LacZ gene was transferred into these cells using a cationic liposome delivery system. The cells were subsequently fixed with 4% paraformaldehyde, mixed with X-gal, then observed under a microscope. Results Blue stain was seen in the cytoplasm of the cultured cells under the microscope, demonstrating the successful transfer of the LacZ gene into these cells. Conclusion Reporter LacZ gene was easily transferred into the cultured ocular cells in vitro. This provides insights into the transfer of the genes into these cells to study the pathogenesis and therapy of glaucoma. Chin Med J 2000; 113(5): 458-460

Objective To investigate variations in hepatitis B virus (HBV) polymerase gene in chronic HBV infected patients resistant to lamivudine therapy. Methods Specimens were obtained from nine patients with chronic HBV infection, who were resistant to lamivudine therapy. Partial segments of the HBV DNA polymerase gene were amplified by polymerase chain reaction (PCR). Nucleotide sequence was performed using an applied 373 automated sequencer. Titre of HBV DNA was measured by branched-DNA assay (Chiron). Results Of nine patients with HBV DNA positive after 64 weeks of treatment, five (56%) had variations in the highly conserved YMDD motif in domain C of the HBV polymerase, three of those were substitutions of isoleucine for methionine (M), and two were substitutions of valine(V) for methionine. Additionally, in two patients with variations characterized by substitutions of V for M, one had a simultaneous amino acid change from the first aspartic acid to glycine and this pattern of variation was not reported in other literatures. With respect to viremia, in two subjects with low titre of HBV DNA (< 100 MEq/ml), no variation was found in the YMDD motif, whereas in seven patients with high titre of HBV DBA (> 300 MEq/ml), five (71%) had variations in the YMDD motif. Conclusions Lamivudine is a potent anti-viral agent for treatment of chronic HBV infection. Resistance to lamivudine is likely caused by the variations in the YMDD motif of the HBV polymerase gene. Chin Med J 2000; 113(5): 455-457

Objective To describe our experience in the treatment of pectus excavatum (PE) using a modified sternal elevation procedure. Methods From Oct. 1986 to Dec. 1997, 171 patients with PE were admitted to the Department of Pediatric Surgery of the First Hospital of West China University of Medical Sciences. All patients were diagnosed through a history and physical examination. Cardiopulmonary function was assessed by M-mode echocardiography and instrument of pulmonary function in 40 patients before and 4.2 years after surgery which was performed between 1989 and 1994. We performed the following three procedures in the sternal elevation: (1) forming the metal strut in a " arch" shape, (2) suturing the perichondrium into a "pipe" shape, and (3) encouraging patients to do chest expansion exercise after operation. All patients were followed up for 1 to 12 years. Results The normal contour of the costal cage was enlarged in all but one patient. Exercise tolerance was improved, and cardiac function recovered to the same level as in healthy children, while pulmonary function recovered very slowly after surgery. Conclusion The normal appearance of chest wall can be recovered and normal cardiopulmonary function can be restored by the modified sternal elevation procedure in children with PE. Chin Med J 2000; 113(5): 451-454

Objective To investigate the relationship between intestinal mucus IgA content and mucus barrier function after surface burns. Methods Detection of IgA content in mucus was performed by enzyme linked immunosorbent assay (ELISA) at different time points after burns. Bacterial adherence to cultured epithelial cells (IEC-6) in vitro using E. coli was assessed for each group. Results The intestinal mucus barrier function declined, parallel to a decrease in IgA content after surface burn in mice. In the normal control group, mucus IgA content was 2.32 Dλ, and 2.51, 1.76, 1.49, 1.06 Dλ at 0.5 h, 1 h, 6 h and 24 h after burn, respectively. Bacterial adherence rate was 0.53 in control group, and 0.46, 0.69, 0.58. 0.81 at 0.5 h, 1 h, 6 h, 24 h after burn, respectively. Conclusion The decrease of intestinal mucus IgA contents is one of the reasons why intestinal mucus barrier function declines after burns. Chin Med J 2000; 113(5): 449-450

Objective To evaluate the role of preoperative transcatheter arterial chemoembolization (TACE) as a palliative approach in hepatocellular carcinoma (HCC). Methods From January 1992 to December 1998, 279 patients with HCC underwent curative liver resection. One to five courses of TACE prior to liver resection were performed in 117 patients (TACE group), while the other 162 patients received only liver resection (control group). All 279 specimens of resected tumors were submitted to the following assessments: PCNA and expression of P53 protein. All specimens from the TACE group were examined for downstaging or necrosis of tumors. Results In the TACE group, gross inspection revealed downstaging or necrosis of tumor in all cases. Total necrosis (100%) of tumor was observed in 11.1% of 117 patients, > 90% but incomplete necrosis in 15.4%, 50% - 90% necrosis in 46.2%and < 50% necrosis in 27.3%. Microscopically, extensive and homogenous coagulative necrosis was observed. Viable cancer cells were also present within and outside the tumor capsule in 111 cases. In the remaining 6 cases, the tumor necrosed completely. In control group, necrosis was observed in 8.0% of 162 cases and reduction of tumor size was < 20%. Microscopically, viable HCC cells were noted in all cases. There was no statistical difference in expression of P53 protein between the TACE and control group. High labeling index of PCNA was significantly higher in the TACE group. Conclusions TACE has a marked antitumor effect resulting in various degree of tumor necrosis, but only a small proportion of tumors show complete necrosis. Since the residual tumor cells following preoperative TACE may have more aggressive behavior, we conclude that sequential liver resection is the preferred therapy whenever feasible and preoperative TACE should be avoided in resectable HCC. Chin Med J 2000; 113(5): 446-448

Objective To study the role and value of gonadotropin-releasing hormone agonists (GnRH-a) and laparoscopy for the treatment of adenomyosis with infertility. Methods Four cases were seen with adenomyosis and infertility, 3 of these cases also presented local adenomyomata in the posterior uterine wall. GnRH-a Triptorelin (decapeptyl) or Goserelin (Zoladex) therapy was instituted for six months before laqaroscopic surgery for coexisting pelvic pathologic infertility factors in one case and after laparoscopic surgery in three cases. Results All cases remained amenorrheic during GnRH-a therapy. After the GnRH-a therapy, all enlarged uterus (7-10 weeks gestation size) all decreased to normal or near normal size; menstruation returned in 80 - 90 days and three cases conceived within four menstrual periods after cessation of treatment. In the 4 cases one pregnancy resulted in the birth of a healthy 3150 g male newborn at 38 weeks gestation by cesarean section; one pregnancy was terminated after adenomyomectomy by emergency cesarean section at 30 weeks gestation because of threatened rupture of uterus; one case was then normal at 28 weeks pregnancy; the last case had 2 resumptive menstrual periods and was still being followed up. Conclusions GnRH-a is markedly efficient in reducing adenomyotic uterine size, facilitates uterine or endometrial receptivity for embryos and enhances uterine ability to maintain pregnancy. For adenomyomata associated with infertility, GnRH-a instead of surgical removal of lesions, which are deep in the myometrium, may avoid uterine rupture when pregnancy occurs. For infertility, GnRH-a treatment before laparoscopic surgery greatly decreases surgical difficulties and blood loss in certain cases. Chin Med J 2000; 113(5): 442-445

Objective To clarify whether genetic variants of the renin-angiotensin system (RAS) contribute to the development of diabetic nephropathy (DN) in the Chinese. Methods Totally 173 Chinese subjects of Han nationality from Shanghai were classified into! control, DN (-) and DN (+) groups. The latter was subdivided according to diabetic duration at the onset of DN and the stage of DN. Genotyping of five polymorphic sites in four key genes of the RAS: the AGT-T174M, AGT-M235T and AGTR1 genotypes were determined by PCR/restriction enzyme digestion. The insertion/deletion (I/D ) and [ACAC] n-STR microsatellite polymorphic markers were used for ACE and REN genotyping, respectively. Statistical analysis showed comparisons of gene frequencies between any two groups were made with Fisher's exact test or Chi-square test. Logistic regression analysis was performed to identify predictors of DN. Results The frequencies of ACE-DD genotype and ACE-D allele were much higher in DN(+) group than in DN (-) group (0.25 vs 0.05, 0.47 vs 0.29, respectively), so were the frequencies of TT genotype and T allele in AGT-M235T (0.73 vs 0.54, 0.85 vs 0.68, respectively). DN (+) DUR < 5 years group had greatly increased frequencies of AGT-M235T allele and ACE-DD genotype in comparison with DN(-) group (0.92 vs 0.68 and 0.28 vs 0.05. respectively). Logistic regression analysis further identified these two genes as contributing factors to DN. Although AGTR1 and AGT-T174M genotyping analysis revealed differences in frequency distribution between DN (+) and DN (-) or control groups, logistic regression analysis failed to implicate them in the development of DN. Conclusions Our study revealed RAS genes, ACE and AGT-M235T but not AGT-T174M, AGTR1 or REN genotypes, as contributing factors for DN in type 2 diabetes mellitus in Chinese. Chin Med J 2000; 113(5): 437-441