Volume 115  ·   Issue 02  ·  2002

Objective To study whether AS2O3 has an apoptotic effect on human solid tumor cells, and the possible cellular and molecular mechanisms of this treatment using human esophageal squamous carcinoma cells(EC8712) as a model. Methods DNA microarray, biochemical and cytological analyses were used. Results The growth and survival of EC8712 cells were markedly inhibited by AS2O3 treatment at a concentration of 1, 2 and 4 μmol/L. EC8712 cells were obviously arrested at G2/M phase with AS2O3 treatment and apoptosis induced at micromolar AS2O3 concentrations, as shown by morphology, histogram related nuclear DNA contents, and DNA gel electrophoresis. As2O3 activated caspase-3, which might be involved in the process of AS2O3, induced apoptosis in EC8712 cells. Conclusions AS2O3 changes the expression of many genes at transcription level. The regulation of expression of many genes might be involved in the process of AS2O3 inducing apoptosis. These results suggest that As2O3 can be clinically useful for solid tumor treatment. Chin Med J 2002; 115(2): 280-285

Obejective To study the effect of cholecystokinin octapeptide (CCK-8) on lipopolysaccharide (LPS)-stimulated pulmonary interstitial macrophages (PIM) in vitro. Methods PIM were isolated and cultured in the presence or absence of LPS, CCK-8, proglumide (the antagonist of CCK receptors) and vehicle. The expression of membrane CD14 (mCD14) protein was assayed by flow cytometry and soluble CD14 (sCD14) in the supernatant was analyzed semi-quantitatively by Western blot. TNF-α in the supernatant was detected with ELISA. Results CCK-8, at concentrations of 10-7 mol/L and 10-6 mol/L, significantly inhibited the expression of mCD14. Release of sCD14 and TNF-α in the supernatant was up-regulated by LPS (1 μg/ml) but reduced by CCK-8. The effect of CCK-8 was inhibited by proglumide. Conclusion CCK-8 negatively modulated several functions of LPS-stimulated PIM through CCK receptors. This may be one of the mechanisms for CCK-8 to alleviate inflammation in lung tissue during endotoxemia. Chin Med J 2002; 115(2): 276-279

Objective To investigate natural foci of tsutsugamushi disease whose incidence has increased in the Nan Peng Lie Islands in China, an area where this disease has not been previously recorded. Methods We recorded the natural foci and isolated Orientia tsutsugamushi (O. tsutsugamushi)organism. We also studied prevention measures. Results These islands had the natural foci of a south subtropical zone. The main host and vector were Rattus norvegicus and Leptotrombidium deliens (L. deliens), respectively. The seasonal quantity trends of Rattus norvegicus and Leptotrombidium deliens were consistent with the incidence of human infection. Thirty-five strains of O. tsutsugamushi were isolated from Rattus norvegicus and L. deliense. The identification of 7 strains showed that most strains were Karp. Seroepidemiology showed a high prevalence of antibody against O. tsatsugamushi among local people. After prevention measures were used, the incidence was decreased. Conclusion This was the first successful confirmation that the Nan Peng Lie Islands were natural foci of tsutsugamushi disease. Chin Med J 2002; 115(2): 272-275

Objective To detect the expression of basic fibroblast growth factor (bFGF) in human ocular tissues, and to assess the effect of bFGF on the proliferation of human cataract lens epithelial cells (LECs) and its correlation with age. Methods Enucleated eyes were subjected to immunostaining for bFGF protein. Human cataract LECs were cultured in vitro, and treated with bFGF for 48 hr. Proliferation was estimated by the positive area ratio of proliferating cell nuclear antigen (PCNA) in immunohistochemistry. Results bFGF protein was found in various human ocular tissues. bFGF stimulated human cataract LEG proliferation, and there was an age-related decrease in responsiveness of human cataract LECs to bFGF(P <0.05). Conclusion bFGF might play an important role in the proliferation of residual human cataract LECs after cataract surgery. Chin Med J 2002; 115(2): 268-271

Objective To study potassium currents in isolated Deiters' cells of guinea pig cochlea and explore possible function of potassium current in Deiters' cell. Methods The whole cell patch clamp recording technique was used to study potassium currents of Deiters' cells in normal external solution and solutions with different K+ concentrations. We also studied the effects on reversal potentials and outward potassium currents . Results Isolated Deiters' cells possess voltage dependent, outwardly rectifying ion channels, which are K+ selective. 50 mmol/L K+ and 150 mmol/L K+ in external solution reduced lk-max from (10.06 ±2.2)nA(n=13) in normal external solution to (6.43± 1.67)nA (n=6, P<0.05) and (5.49± 1.33)nA (n=6, P <0.05), respectively. While the amplitude of tailcurrents decreased from (468.76 ± 61.76)pA in 5 mmol K+external solution to (224.74±35.89) pA (P <0.05) in 50 mmol/L K+ and to (- 911.59 ± 78.17)pA(P <0.01) in 150 mmol/L K+ external solution. Conclusions Outwardly rectifying potassium in Deiters' cells could buffer extracellular K+ in the small space between Deiters' cells and outer hair cells or neural fibers and participate in the diffusion of K+ from endolymph to perilymph. Chin Med J 2002; 115(2): 264-267

Objectives To investigate the tissue specificity of reactive oxygen species (ROS) damage to mitochondrial DNA (mtDNA) and to determine whether cochlear mtDNA is a sensitive target for ROS damage. Methods 10 Cu/ZnSOD gene (Cu/Zn superoxide dismutase gene, Sod1) knockout mice and 16 wild-type mice were analyzed by nested polymerase chain reaction (PCR). Results Three deletions were detected in various tissues of Sod1 knockout mice. MtDNA3867bp and mtDNA3726bp deletions were the most visible, and mtDNA4236bp deletion was barely detected in these tissues. There were obvious differences in the ratio of deleted mtDNA/total mtDNA in different tissue. Deleted mtDNA was most abundant in the liver and kidney and less in cochlea, heart and brain. The lowest was in spleen and skin. The ratio in various tissues was 3-20 times in Sod1 knockout mice over wild-type mice. In cochlea, the ratio was about 15. Conclusions Without the protection of Sod1, ROS can lead to mtDNA deletions in various tissues with significant tissue specificity. Cochlear mtDNA is a sensitive target for ROS damage. Chin Med J 2002; 115(2): 258-263

Objectives To explore the potential use of ultrasound measurement (SoundScan 2000 Compact, Myriad Ultrasound Systems Ltd ., Rehovot, Israel), and to assess both quantitative and qualitative properties of bone. Methods The speed of sound waves (SOS; m/s) propagating along the cortical bone was determined at the tibial shaft. The performance, reliability, validity, and clinical application of this system were evaluated in Japanese subjects . Results In phantom experiments, validity of this system was 0.04(%), coefficient variation (CV: %) in same-day tests was 0. 12, in five-separate-day tests was 0. 13, and in independent operators was 0. 11,respectively. In experiments with Japanese subjects, CV in same-day tests was 0.38, in five-separate-day tests was 0.99, and in independent operators was 0.90, respectively. In addition, cortical bone status of 1176 Japanese subjects (372 males, 804 females) was clinically evaluated by SoundScan 2000 Compact. SOS was negatively correlated with body fat percentage (%), body fat (kg) and waist hip ratio in females and subjects with higher weight bearing index (leg strength/body weight; WBI) have higher SOS in females under the age of forty. Conclusions These findings indicate that the SoundScan 2000 Compact is a highly reliable and valid method for determining cortical bone status and body composition and WBI are closely related to cortical bone status in Japanese females. Chin Med J 2002; 115(2): 254-257

Objectives To investigate the findings of magnetic resonance (MR) imaging and histopathology in early postoperative normal brain, and to define the correlation between MR images and histopathology. Methods Thirty-six New Zealand rabbits weighing 2.0 to 3.0 kg were divided into 10 groups according to different postoperative days: 1 to 10 days. A partial resection of the parietooccipital region was performed under usual aseptic conditions after the animals were anesthetized intravenously with 3%pentobarbital(30 mg/kg). MR imaging procedures consisted of pre- and postcontrast scanning and were carried out on postoperative days 1 to 10. Brain tissue samples were prepared for examination immediately after MR scanning. Histopathological examination was done under light both and electron microscopes. The findings of MR imaging were compared with histopathologic findings. Results Surgical margin contrast enhancement on MR images could be seen 24 hours after surgery . The degree of contrast enhancement increased gradually up to 5 days postoperation, and no remarkable changes were present from days 5 to 10. Disruption of the blood brain barrier (BBB) was the main cause of contrast enhancement during the first 3 postoperative days. After that period, the mechanism responsible for contrast enhancement was the formation of neovascularity and a broken BBB. An increase in the amount of neovascularity played a predominant role in contrast enhancement in normal postoperative brain tissue. Conclusions The features of enhanced MR images present at the surgical margin followed a typical time course during the early postoperative period. The role of neovascularity and BBB disruption in the formation of contrast enhancement at the surgical margin varies with time. Knowledge of the features of contrast enhancement in postoperative MR images of normal brain can help in differentiating benign changes from residual malignant glioma. Chin Med J 2002; 115(2): 247-253

Objective To probe into the clinical manifestation, diagnosis, as well as treatment of pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester. Methods Analysis of 14 patients with pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester was made after conservative treatment by drugs from January 1996 to December 1999. Results The 14 patients with a pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester were painless, had slight vaginal bleeding, and concurrently had increased serum β-subunit human chorionic gonadotropin (β-HCG) . Doppler ultrasonic examination revealed an obvious enlargement of the previous cesarean section cicatrix in the uterine isthmus, and found a gestational sac or mixed mass attached to the cicatrice, with a very thin myometrium between the gestational sac and bladder walls. Among the 14 patients, 12 patients had crystalline trichosanthes injected into the cervix, mifepristone taken orally, or methotrexate in the form of intramuscular injection. Following this procedure, their serum p-HCG dropped to normal. The other 2 patients had a total hysterectomy. Conclusions Pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester is a complication of cesarean section. Early diagnosis and effective conservative treatment by drugs are instrumental in decreasing the potential occurrence of uterine rupture, which is also conducive to preserving the patient's future fertility. Chin Med J 2002; 115(2): 242-246

Objective To investigate the mechanism of multidrug resistance (MDR) in a human glioma cell and methods for overcoming multi-drug resistance. Methods MDR cell line C6/adr was established. The expression of the mdr-1 gene and its P-glycoprotein(P-gp) in the C6/adr cell line was observed by RT-PCR and flow cytometry. The reversal of MDR by verapamil, erythromycin, dihydropyridine, P-gp monoclonal antibody and Salvia miltiorrhiza (SM) was studied by microtiter tetrazolium (MTT) assay or by high performance liquid chromatographic assay. Results The mdr-1 gene of the C6/adr cell line was positive, over-expressing P-gp. The drug-resistance of the C6/adr cell lines could be partly reversed by 2 - 6 μg/ml of verapamil, 50 - 100 μg/ml of erythromycin, or 5 μg/ml of dihydropyridine. As concentration increased, they had a better effect. Among these drugs, 100 μg/ml of erythromycin had the best result of reversal. Dihydropyridine 1 μg/ml, P-gp monoclonal antibody and SM had no effect. Conclusion The mdr-1 gene and its expression might be associated with the MDR of glioma cells. Verapamil, erythromycin and dihydropyridine could reverse the MDR of glioma cells. Chin Med J 2002; 115(2): 238-241

Objective To make quantitative analysis of DNA content of breast concer with neuroendo- crine (NE) cells and its significance. Methods Using MIPS-Ⅲ image analyzer, DNA content and 9 parameter measurements of the tumor nuclei were made in both NE positive (17) and negative (64) breast carcinomas. Results Out of 81 breast carcinomas, 17 cases were NE positive while 64 cases were NE negative. In the NE (+) cases, the integral optic density, mean optic density, DNA index, DNA stemlines peak,> 5c aneuploidy cells and the rate of aneuploidy cells were all lower than those in the NE negative breast carcinoma cases (P <0.01) . The positive rates of NE cells were 32.5%and 7.9%in grade Ⅰ - Ⅱbreast carcinomas and in grade Ⅲ breast carcinomas respectively with significant difference between the two groups (P<0.01). Conclusion Our study shows that NE (+) breast carcinomas have lower DNA parameters than NE (-)breast carcinomas, suggesting that NE (+) breast carcinomas have lower malignancy. Chin Med J 2002; 115(2): 296-298

Objective To explore the effect of shenmai injection (SI) on expression of TNF-α mRNA in peritoneal macrophages (pMΦs) of scald mice. Methods BALB/c mice were inflicted with 11 %of body surface area Ⅲ degree scald and injected intraperitoneally (ip) with SI daily for 5 days, and expression of TNF-α mRNA in pMΦs was determined by semi-quantitative RT-PCR. Results In scald mice, the expression of TNF-α mRNA in pMΦs increased significantly, but it was reduced obviously (P <0.01) after SI administration, while the livability was increased markedly (P < 0.05). Conclusions For scald mice, the cause of death at early stage might be related to the high expression of TNF-α mRNA in pMΦs and the use of SI can decrease the death rate. Chin Med J 2002; 115(2): 293-295

Objective To investigate whether telomerase activity, human telomerase RNA (HTR) and human telomerase reverse transcriptase (HTERT) expression were associated with tumor development in lung cancer and whether telomerase is regulated at gene level or transcriptional level. Methods Expression of HTR and HTERT was detected by reverse transcription-polymerase chain reaction(RT-PCR) in 68 human lung cancer and in 68 adjacent-neoplatic lung tissues. And telomerase activity was examined by a quantitative telomeric repeat amplification protocol (TRAP). Results In 68 lung cancer tissues, telomerase activity, HTR and HTERT were expressed in 79%, 98.5%and 91.2%respectively, whereas all adjacent non-neoplastic lung tissues were telomerase negative. Most normal lung tissues expressed HTR (91.2%) and HTERT was detected in only 7 of 68 non-neoplastic tissues. Conclusions The relatively high frequency of telomerase activity in lung cancer whereas the detection of no telomerase activity in normal lung tissues suggested that telomerase may play an important role in tumorigenesis of lung cancer. Compared to HTR, HTERT expression was better associated with telomerase activity with a concordance of 88.9%. Telomerase activity may be regulated at transcription level or translation level. Chin Med J 2002; 115(2): 290-292