Volume 113  ·   Issue 01  ·  2000

Objective To study the biological effect of arsenic trioxide (As2O3) on human cervical cancer SiHa cells and Siha cells overexpressing bcl-2 gene. Methods SiHa cells with overexpression of Bcl-2 (SiHa-Bcl2 cells) were established by transfecting SiHa cells with Bcl-2 cells to As2O3 were determined using MTT (Thiazolyl blue) reduction and colony forming ability assay6, morphological analysis, flow cytometric analysis, DNA anarose gel electrophoresis, in situ cell death detection (TUNEL), Northern blot, RT-PCR and Western blot. Results As2O3 inhibited the growth of SiHa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR and Western blot analysis revealed that As2O3 induced SiHa cell apoptosis possibly via inhibiting the expression of HPV16 E7 and decreasin the expression of c-myc. However, we found that SiHa-Bcl2 cells partly resisted As2O3 induced apoptosis, which might be related to the prevention of the down-regulation of HPV16 E7 and c-myc gene expression. Nevertheless, As2O3 at a high concentration could still induce apoptosis of SiHa-Bcl2 cells mainly via decreasing Bcl-2 expression and slightly inhibiting viral gene expression. Conclusion As2O3 is an inducer of the apoptosis of human cervical carcinoma cells and the cells overexpressing Bcl-2 can partly resist As2O3 induced apoptosis, but the exact mechanism is unclear. Chin Med J 2000; 113(1):84-88

Objective To identify the relationship between mutation in the insulin receptor substrate-1 (IRS-1) gene and the incidence of non-insulin-dependent diabetes mellitus (NIDDM) in the Chinese population. Methods Samples were obtained from 68 Chinese patients with NIDDM and 68 control subjects. The + 1700~ + 4437 bp fragment of the IRS-1 gene was screened by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. All SSCP variations were submitted to DNA sequence analysis. Results Two amino acid variations [ GGG → AGG (G971 R) and CCT → TCT ( P1079 S)] and 3 silent mutations [ GAT→GAC (D422 D), CCA→CCC (P737 P) and GCA→GCG (A804 A)] were identified, among which the CCA→CCC(P737P) and CCT→TCT(P1079S) have not been previously reported. All five variations were found in Chinese patients with NIDDM, while GCA→GCG(A804A) was the only one found in control subjects. The overall incidence of the five variations in Chinese patients with NIDDM were much higher than that in control subjects (38.2% vs 7.4%, x2 = 18.42, P < 0.01). The most common polymorphism in the Chinese population was GCA→GCG(A804A), and its frequency was significantly higher in Chinese patients with NIDDM than in controls (26.5% vs 7.4%, x2 = 8.84, P < 0.01) . The homozygotes of the variation in patients with NIDDM and control subjects were 8.8%and 1.5%, respectively (x2 = 2.41, P >0.05). Conclusion These results indicate that there may be a relation between these nucleotide variations of IRS-1 gene and Chinese patients with NIDDM. Chin Med J 2000; 113(1): 80-83

Objective To quantitatively measure the temporal profiles of intercellular adhesion molecule-1 (ICAM-1) protein in mouse brain after middle cerebral artery occlusion (MCAO). Methods Adult male CD-1 mice received 0, 3, 6, 12, 24, 48 and 72 hour(s) of permanent MCAO with an intraluminal suture technique. The degree and the extent of occlusion were determined using a laser Doppler flowmeter. ICAM-1 positive expression in ischemic regions was determined immunohisto-chemically and ICAM-1 protein was quantitatively measured using immunoprecipitation and Western blot analysis. Results After MCAO, surface cerebral blood flow (CBF) in the ischemic hemisphere decreased to 9% - 15% of the baseline in each time point of 7 to 8 animals. There were no significant differences in CBF measurement during occlusion between groups. Immunohistochemistry showed that ICAM-1 positive microvascular endothelial cells were observed both in the ischemic core and in the perifocal region. There was a tendency for increasing expression of ICAM-1 positive microvascular endothelial cells from the ischemic core to the ischemic margin. Western blot analysis showed that ICAM-1 expression in the ischemic hemisphere began to increase 3 h after MCAO, peaked at 6 h to 12 h, and persisted to 72 h. Conclusions ICAM-1 expression increases in mice with permanent MCAO because ICAM-1 can mediate leukocyte-endothelial adhesion and progression of leukocyte infiltration after permanent focal cerebral ischemia. ICAM-1 is one of the important factors participating in ischemic cerebral damage and pathogenesis of stroke. Chin Med J 2000; 113(1): 75-79

Objective To investigate the relationship between neuroendocrine differentiation in ovarian mucinous tumors and its genesis. Methods A morphologic study of seventy-three cases of ovarian mucinous tumors (32 benign, 20 borderline, 21 malignant) using immunohistochemical and immunohistochemical/histochemical double staining techniques. Results The study showed that in tumors of benign, borderline and malignant types, the incidence of chromogranin A (CgA) positive cells was 62.5%. 75%, 76% and that of 5-hydroxytryptamine (5-HT) positive cells was 31.3%, 40% and 39%, respectively. Neuroendocrine cells (NEC) were not evenly distributed in any tumor. In four cases of the benign tumors, the number of CgA positive cells was more than 30 percent, localizing between the glandular basement membrane and the mucinous epithelial cells, with many intermediate cells containing both CgA and periodic acid-schiff (PAS) positive granules. Conclusion The occurrence of both neuroendocrine and exocrine granules within the same cell has been previously described as "intermediate" in pancreatic hyperplasia, pancreatic tumors and lung signet-ring cell carcinoids. This has not previously been observed in benign ovarian mucinous tumors. Finding both endocrine and exocrine granules within a single cell seems to indicate a histogenetic relationship between the ovarian endocrine and exocrine cells. The four cases of the benign tumors might be originated from a common stem cell, such as the so-called amphocrine cell. The relationship between these four tumors and neuroendocrine differentiation in ovarian mucinous tumors needs to be further clarified. Chin Med J 2000; 113(1): 70-74

Objective To investigate the characteristics of Hodgkin/Reed-Sternberg (H/R-S) cells found in patients with various types of Hodgkin's disease (HD). Methods H/R-S cells were micropicked from frozen sections of tissues affected by HD. The DNA from these cells was amplified by polymerase chain reaction (PGR) using immunoglobulin heavy chain gene FIR Ⅲa/JH primers and light chain gene family-specific primers. Results A total of 52/135 (35.8%) isolated cells showed the specific products in the reactions. IgH and Vκ4 rearrangements were repeatedly found in many cells from a lymphocyte predominance type sample; repeated Vκ4 and individual IgH/Vκ2,4 rearrangements and individual IgH, Vλ3/ Vκ4 rearrangements were found in two different cases of the nodular sclerosis type; repeated IgH/ Vλ3 and individual Vλ2,4 rearrangements, repeated Vκ2,4 rearrangements, repeated Vκ4 and individual IgH/ Vκ3 rearrangements, repeated IgH and individual Vκ3/ Vλ4 rearrangements were detected in 3 cases of the mixed cellularity type. Repeated and individual IgH rearrangements were found in other 2 cases. Conclusion The H/R-S cells isolated from the lymphocyte predominance subtypes of HD have IgH and Vλ4 gene rearrangements. This suggests that the lymphocyte predominance type is a proliferation of neoplastic B cells. The cells isolated from the mixed cellularity and nodular sclerosis types derive from B lineage cells at various stages of differentiation because of the presence of their IgH, κ and/or λ gene rearrangements. To our knowledge, this is the first time that the λ gene rearrangement was detected in H/R-S cells. Chin Med J 2000; 113(1): 65-69

Objective To determine the role of membrane potential and intracellular calcium kinetic changes in producing vascular hyporeactivity during severe hemorrhagic shock. Methods Rats were subjected to hemorrhagic shock (HS) for 2 hours. The spinotrapezius muscle was prepared for microscopy and the responses of arterioles in the muscle to norepinephrine(NE) were tested. The resting membrane potentials of isolated arterial strips were measured with a microelectrode. Membrane potential and intracellular Ca2+ ([Ca2+ ]i) changes in isolated arteriolar smooth muscle cells (ASMCs) were determined with fluorescent probes and a confocal microscopy. Results The arteriolar resting membrane potential was decreased from - 36.7 ± 6.3 mV in control to -29.2 ± 5.3 mV concurrent with the increase of vasoreactivity to NE at 20 minutes after HS. At 120 minutes post-HS, the resting potential hyperpolarized to - 51.9 ± 9.1 mV, and NE stimulated [Ca2+ ] i increase was reduced to 50% of the control values during the appearance of arteriolar hyporeactivity, i. e. the NE threshold of the arteriolar response increased 15 fold 2 hours after the onset of hemorrhage as compared with normal animals. The state of vasoreactivity was closely related to the resting potential of vascular smooth muscle in hemorrhagic shock, with a correlation coefficient of 0.96. Treatment with glybenclamide, a selective blocker of ATP-sensitive K+ (KATP) channels, decreased the resting potential, increased NE-stimulated [Ca2+]i increase, and partially restored vasoreactivity in severe hemorrhagic shock. Conclusion The results suggested that membrane hyperpolarization and the reduction of NE-stimulated [Ca2+ ]i increase in smooth muscle cells appeared to contribute to the vascular hyporeactivity in hemorrhagic shock. The mechanism is likely to involve in KATP channels. Chin Med J 2000; 113(1): 59-64

Objective To assess the efficacy of fractionated administration of radiolabeled monoclonal antibody in the treatment of metastases after tumor volume reduction surgery, various experimental therapies were studied comparatively. Methods A total of 200 inbred mice received tumor implantation from a murine adenocarcinoma cell line. The mice were randomly grouped to give saline, Arc-a, 131I-C50 in single or fractionated doses, cold C50, or non-specific 131I-IgG with or without surgical removal of the implanted tumor xenograft. Results In comparison to controls, animals receiving Arc-a and radioactive agents had longer survival, smaller tumor, better clinical condition, and less metastases foci. The best therapeutic response was noted after fractionated doses of 131I-C50, which showed better results in every aspect than those treated with other modalities. The favorable outcome was even more pronounced after tumor volume reduction. Conclusions Fractionated dosing may improve the deposition of radiolabeled monoclonal antibody (McAb) and provide the best therapeutic effect on implanted tumor and metastases. Thus fractionated radioimmunotherapy (RIT) after tumor volume reduction might be a practical method with promising therapeutic results. Chin Med J 2000; 113(1): 53-58

Objective To study the cardioprotective effects of hypoxic preconditioning (HPC) on aged rat ventricular myocytes and the cellular mechanism of protection. Methods In the model of hypoxia/reoxygenation (H/R) of isolated ventricular myocytes of aged rat, the effects of HPC on aged rat ventricular myocytes against lethal H/R stimulated ischemia/reperfusion (I/R) injury 24 hours later and the changes of mitogen-activated protein kinase (MAPK) system were observed in the present study. Results HPC attenuated the lactate dehydrogenase (LDH) release and ATP depletion in myocytes and increased the viability of myocytes. It was also found that MAPK and its down-stream kinase-S6 kinase were also activated after HPC. Conclusion There is delayed cardioprotection in cardiac myocytes of aged rat and the cellular mechanism underlying might involve the activation of MAPK system. Chin Med J 2000; 113(1): 5-9

Objective To investigate the effect of Q-switched alexandrite laser irradiation on dermal melanocytes of nevus of Ota. Methods Multiple biopsies were carried out on 4 patients with nevus of Ota before and after laser irradiation. Altogether 11 samples were examined under light microscope and 14 under transmission electron microscope. Results Immediately after laser irradiation, the dermal melanocytes were destroyed, the melanosomes were degenerated with central vesicle formation within most of them, and intradermal round vacuoles appeared. The epidermis remained intact. Three months to 1 year after irradiation, the degenerated melanosomes and cell debris were scavenged mainly by macrophages. Dermal melanocytes gradually decreased. No fibrosis was found. Conclusion Q-switched alexandrite laser can selectively destroy dermal melanocytes of nevus of Ota and treat the disease safely. Chin Med J 2000; 113(1): 49-52

Objective To investigate the characteristics of mutations in exon 3 - 20 of Wilson disease (WD) gene and their consequences in Chinese population. Methods Sixty unrelated normal Chinese and forty-four unrelated WD patients were studied. Genomic DNA was prepared from peripheral blood leukocytes by a salt-out method. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and subsequently direct sequencing were used to identify the mutations and polymorphisms of WD gene. Results Ten different mutations have been found, accounting for 52% of the mutant genes. Five of them are identified as novel missense mutations. Mutations Arg778Leu, Thr935Met and Ala874Val were represented respectively in 28.4%, 6.8% and 3.4%of WD chromosomes. The remaining mutations were found rare and limited to one or two patients. A total of 11 patients were homozygous for a single mutation, and 17 patients were in a compound heterozygous state with or without a known mutation. Conclusion In Chinese, WD seems to result from two or three relatively common mutations and a large number of rare mutations. Arg778Leu and Thr935Met might be hotspots of mutation in Chinese population. The results indicated that the feature of mutations of WD gene is different between Chinese and the Western. Instead of exon 14 and exon 18, we had to select exon 8 and exon 12 first to detect mutations of WD gene in Chinese. It is of great importance to establish a direct diagnostic method for WD. This study improves our knowledge on functional domains of the WD gene, and helps elucidate the wide spectrum of manifestations of the disease as well. Chin Med J 2000; 113(1): 40-43

Objective To estimate the effect of borderline hypertension on the left ventricular hypertrophy and left ventricular diastolic function. Methods Doppler echocardiography was performed and ambulant blood pressure (ABP) was monitored in 92 borderline hypertensive (BH) patients and 36 normotensive subjects, and the following parameters were detected: left ventricular end-diastolic dimension (LVDd), interventricular septal thickness (IVST), posterior wall thickness (PWT), rapid filling phase and late diastolic filling phase peak flow velocity (E and A), the ratio of E/A, isovolumic relaxation time (IVRT), decelerating time (DT) of E peak and internal dimension of left atriuum (LAD) . Left ventricular mass (LVM) was calculated by Devereux equation: LVM(g) =0.8 x 1.04[(LVDd + IVST + PWT)3 -LVDd3] + 0.6. Left ventricular mass index (LVMI, g/m2) was calculated by dividing the value of LVM by body surface area. The upper limits of normal of LVMI were 125 g/m2 for men and 120 g/m2 for women. The ABP's parameters were calculated according to the original readings: (1) average 24-hour blood pressure; (2) daytime and nighttimeblood pressure; (3) blood pressure load values (the percentage of SBP > 140 mm Hg and DBP > 90 mm Hg during daytime or SBP > 120 mm Hg and DBP > 80 mm Hg during night-time); and (4) the ratio of nighttime and daytime blood pressure. Results The left ventricular hypertrophy was found in 17 of 92 BH patients (18.5%). In the study group, 76 cases presented a "dipper pattern" ABP curve, and only 12 of them (15.8%) had LVH, however, 5 (31%) of the other 16 cases with "no-dipper pattern" had LVH. The LVMI in BH group was significantly higher than in normotensives (107.2±13.5 g vs 92.5±11.6g, P <0.01), and it was closely correlated with daytime SBP and load value of daytime's SBP (r = 0.30 and 0.28, respectively, P < 0.01), it also correlated to the 24-hour SBP and night/day SBP ratio (r = 0.25 and 0.22, respctively, P < 0.05). The left ventricular diastolic function was obviously damaged in BH group, compared with those in the normotensive group, all items which reflect the LVDF except IVRT were significantly higher in BH group (P < 0.05 - P < 0.01), which reveals that BH patients have developed insufficient LVDF. Conclusions The study suggests that left ventricular structure and function are impaired in BH patients. SBP level and the day-night rhythm disorder are responsible for the left ventricular involvement. Since BH patients can develop LVH and insufficiency of LVDF which has increased the risk of cardiovascular diseases, it is necessary for us to strengthen the medical care of the BH population to stratify the risk factors and give them adequate directions and reasonable treatments.

Purpose To summarize the main achievements of the control of malaria in the People's Republic of China. Data sources The data are from national case reporting system (1955 - 1998), and bibliographic reviews of textbooks and review articles. Study selection Successes in control and research of malaria were identified and selected to address the stated purpose. Data extraction In the past 50 years, large-scale malaria control activities were conducted in the country, relying on primary health care networks and community participation. The control of malaria was implemented according to the time- and locality-oriented approaches. As a result, remarkable success has been achieved. By the end of 1998, there were 31.3 thousand malaria cases in China, with a morbidity of 0.25 per ten thousand, which dropped by 99% in comparison with that in the 1950s. Results Most of the original hyper-endemic areas became meso- or hypo-endemic and for most of the previously meso- or hypo-endemic areas, the disease became sporadic. Malaria distribution and epidemic pattern also demonstrated great changes. Conclusions Malaria control in China has been considerably successful in the past 50 years, which coincides with the target of the World Health Organization's "Health for all by the year 2000". Chin Med J 2000; 113(1): 89-92