Volume 113  ·   Issue 06  ·  2000

Objective Cholera caused by Vibrio cholerae biotype eltor (EVC) is an endemic disease, subsiding in winter and reappearing in spring and summer. Investigating the state of EVC during the intermittent time is of crucial importance in controlling this disease. Methods Different factors mimicking the internal and external environmental conditions of the host, including human and fish bile, bacterial phages and antibiotics were used experimentally to induce variation in EVC. EVC variants were isolated from the stool of diarrhea patients and river water in old endemic areas during the winter. The variants obtained were tested with gene probe hybridization, DNA restriction enzyme mapping, immunoenzyme staining and animal passaging. Results Due to the loss of cell walls, 3 kinds of EVC variants were obtained during induction: the L-form variant, with a complete loss of cell walls; the nonagglutinating variants, with the loss of surface O-antigen; the phage-resistant variants, with the loss of phage receptors. Similar variants were found in field isolation. This variation was proved to be phenotypic, with no change in genetic material: it was reversible and appeared in a seasonal pattern, which coincided with the endemicity of this disease. Passage in animal enhanced this reversion. In compensation for the loss of cell walls, cell membranes were greatly thickened, increasing the ability of the variants to survive during the unfavorable winter conditions. Conclusions EVC varied in a seasonal pattern, coincident with the endemicity of this disease. The compensatory thickening of the cell membranes protects the EVC variants to survive the winter. Chin Med J 2000; 113(6): 568-570

Objective To successfully transduce a mutant erbB-2 gene into normal human CD34+ -derived dendritic cells (DCs) and verify gene expression in these transduced dendritic cells. Methods The packaging cell line PA317 was transfected with mutant erbB-2 gene DNA and the virus produced was used to infect packaging cell line PG13. The virus produced by PG13 was used to infect CD34+ -derived dendritic cells by the spinoculation method using flasks coated with fibronectin material to facilitate retrovirus gene transfer efficiency and the mutant erbB-2 gene expression was assessed by ABC staining and FACScan methods. Results A mutant erbB-2 gene packaging cell line was produced and this mutant gene was transduced into human CD34+ -derived DCs. It was verified that the relatively large numbers of the transduced DCs expressed the mutant erbB-2 protein which was eradicated of the ability to transform mouse NIH3T3 fibroblast cells. Conclusions Human DCs can be gene-modified and these gene-modified DCs may be useful in stimulating T lymphocytes for immunotherapy. Chin Med J 2000; 113(6): 563-567

Objective To examine the effects of melatonin on the dynamic changes in the concentration of intracellular free Ca2+ ([Ca2+ ] i) in single intact cultured cortical neurons isolated from fetal rats, in order to explore the possible antiaging mechanisms of melatonin (MT). Methods Using the highly fluorescent Cat2+-sensitive indicator Fluo-3/AM, cortical neurons cultured in a 35 mm Tissue Culture Dish were in incubated for 45 min at room temperature with 5 μmol/L Fluo-3/AM, resulting in proper intracellular dye concentration to provide adequate signal strength for detection and excellent Laser Scanning Confocal Microscopy (LSCM) imaging of [ Ca2+ ] i while not disturbing normal intracellular physiology. The changes in fluorescent intensity were monitored by LSCM. Results Bay K8644 (10-6 mol/L), KCI (20 mmol/L), sodium L-glutamate (Glu, 50 μmol/L) caused a rapid increase of [ Ca2+ ] i in cortical neurons, and this increase could be significantly attenuated by 10-6 and 10-7 mol/L MT. Conclusions MT could antagonize the extracellular Ca2+ influx, reduce Ca2+ overload, and have a protective effect on neurons. This may be one of the important antiaging mechanisms of MT. Chin Med J 2000; 113(6): 558-562

Objective To investigate the use of the Gibbs-Sampler method in evaluating the relationship between clinic events and health risks in a meta-analysis of multiple clinical trials. Methods By using a generalized linear model with random-effects, Gibbs-Sampler technique was used in a meta-analysis of multiple clinical trials of angiotensin converting enzyme (ACE) inhibitors in patients with myocardial infarction (MI). Results When heterogeneity across different trials can not be ignored, compared with the classic method, the odds ratio of relative reinfarction risk estimated by the Gibbs-Sampler method would have less variation. The gain in the reduction of variation in estimate of the overall odds ratio was 9.52%. Conclusion Implementation of the Gibbs-Sampler technique in meta-analysis of multiple clinical trials has the potential of reducing the inaccuracy caused by heterogeneity across trials. Chin Med J 2000; 113(6): 554-557

Objective To detect the location and geographical features of gene mutation of the cancer based on 30 709 clinical tumor biopsies. Methods Thirty thousand seven hundred and nine cases of tumor biopsy materials were collected from the Department of Pathology of Nantong Cancer Hospital between June 1974 and December 1987. The address of the village and county of patients was collected and statistical analysis was performed on data from lab examination. DNA sequencing of 31 cases of hepatocellular carcinoma (HCC) was performed at the Department of Pathology of the Medical College of Tokyo University, Japan. Results The data suggested that different carcinomas occurred predominantly in some districts and the frequency and type of mutation of the P53 gene in the HCC were different in different districts. Conclusion It seems that based on the clinical biopsy materials, carcinomas of the uterus cervix (CC) and nasopharynx tend to occur in some districts of Nantong City and the frequency and type of mutation of the gene P53 of the HCC were different in different districts. The reason for this is not understood and further study will be done. Chin Med J 2000; 113(6): 551-553

Objective To evaluate the role of genetic factor in the development of nonresponder or hyporesponder to hepatitis B vaccine in Chinese people from field epidemiology and experimental study. Methods Six hundred and thirty-four susceptible healthy students were vaccinated with three doses of plasma-derived hepatitis B vaccine. Twenty-nine non-or hypo-responders (subjects) and 30 hyperresponders (controls) as well as their 80 and 79 first degree relatives were determined and recruited in the study. The first degree relatives of subjects and controls were then immunized with hepatitis B vaccine and followed up. On the basis of the above results, alleles of HLA-A, B, C, DR and DQ locus were further detected in the two groups. Results The non- and hypo-response rate in immunized students was 4.6% (29/634). After administered with hepatitis B vaccine, the first degree relatives of the subjects displayed a 17.9% frequency of nonresponsiveness, higher than in the controls. The phenotype frequency of HLA-DR7 and B54 was 52.2%and 21.7% in subjects, 9.1% and 0.0% higher than in controls, respectively. The extended haplotype B54-DR7 was more frequent in the former (17.0%) than in the latter (0.0%) (P < 0.01). Conclusion These results demonstrated that the genetic factor was likely associated with the non- and hypo-response to hepatitis B vaccine in Chinese people. Chin Med J 2000; 113(6): 547-550

Objective To observe the influence of the artificial plastic vagina on overall patient health. Methods Length and width of the artificial vagina were measured. Histological studies were performed under light and electron microscope. Vaginal bacterial flora were analyzed using the drop-implant method. Vaginal HPV and ER were detected with ABC histochemical staining. Results According to the results of anatomic measurements, artificial vagina was similar to normal vagina. The reductions of glands in the mucosa and collagen fibers as well as interstitial tissue hyperplasia in the lower segment of artificial vagina were documented. Four kinds of bacteria indigenous to the sigmoid colon were found in artificial vagina and were studied microbiologically with only differences in the amount and detection rates of bacteria flora. The positive presentation of HPV was not significantly different from that in the control group. The positive presentation of estrogen receptor (ER) in the epithelium of artificial vagina was not found. Conclusion The reconstruction of artificial vagina with sigmoid colon is a safe, effective and satisfactory procedure for the patient. Chin Med J 2000; 113(6): 544-546

Objective To investigate the early recognition and management of acute fatty liver of pregnancy (AFLP) to improve maternal and fetal survival. Methods Eight cases of AFLP seen in our hospital during the past three years were studied retrospectively. Symptoms, laboratory findings, timing of liver biopsy, and maternal and fetus outcome were assessed. Results The mean gestational age at onset was 34 ± 2 weeks. All cases were primigravida. In the early stages, all patients presented malaise, nausea, vomiting and epigastric distress followed by jaundice in the third trimester of pregnancy. Laboratory findings: all had raised transaminases and serum bilirubin (32.5 - 510.8 μmol/L), hypoalbuminemia (22.4 -30.0 g/L), hypofibrinogenemia (< 180 mg/dl), prolonged prothrombin time and prolonged partial thromboplastin time. Maternal complication included hepatic encephalopathy (6 cases), ascites (6), hypoglycemia (5), hematemesis (2), and postpartum hemorrhage (5) and preeclampsia (4). Emergency cesarean section was performed in 3 cases. One mother died of fulminant hepatic failure and the others survived. There was no fetus death. Liver biopsy was done on the 5th to 15th postpartum day in 8 cases. Conclusion With increasing awareness, especially in the early recognition of milder cases, and prompt progressive management including early termination of pregnancy by cesarean section and large dose infusion of fresh frozen plasma and albumin alternately, the prognosis of AFLP can be improved. Chin Med J 2000; 113(6): 540-543

Objective To observe the effect of the transfer of multidrug resistance gene (mdrl) into human hematopoietic progenitor cells (HPC) on the chemoprotection. Methods Human CD34+ cells served as a target of mdrl gene transfer. Retroviral vector SF-mdr containing human total length mdrlcDNA was introduced into packing cells GP-envAM12 by liposome-mediated transfection. The mdrl gene was transduced into human CD34+ cells by retroviral supernatants of packing cells. The integration and expression of the mdrl gene and its protein (P170) in transduced cells were determined by PCR, RT-PCR, and flow cytometry. The drug resistance of chemotherapy in transduced HPC was determined by culturing colonies. Results The mdrl gene was integrated and expressed in transduced CD34+ cells. The efficiency of mdrl gene transfer was 10% - 14%. Compared with untransduced controls, within a certain range of drug concentration, the number of drug-resistant colony in transduced HPC for taxol, doxorubicin, VCR and VP16 were increased by 3.6 ± 2.1 fold, 2.9 ± 0.3 fold, 1.9 ± 0.4 fold, and 3.5 ± 0.5 fold, respectively. Conclusion The transfer of the mdrl gene into human HPC can increase the drug resistance of the transduced cells to corresponding chemotherapeutic drugs that may provide some degree of chemoprotection for HPC. Chin Med J 2000; 113(6): 536-539

Objective To compare the epidemiology, local and regional invasion and prognosis of head and neck malignant fibrous histiocytoma (MFH) and extremity MFH. Methods Between January 1, 1972 and December 31, 1993, 173 patients with MFH (71 head and neck, 102 extremities and trunk) were referred to the Cancer Hospital for surgical treatment. They were 101 men and 72 women, with age ranging from 13 to 83 years (median: 45 years). The extent of surgery was classified into radical, wide and local resection. Results For head and neck, local recurrence of MFH after wide resection was 80.4% (37/46), compared with 36.4% (8/22) after radical surgery (P = 0.000). The five-year survival was 50.79% in all the head and neck patients (74.75% in patients free of local recurrence, 37.74% in patients with local recurrence; P = 0.0181), compared with 70.71 % in extremity patients (P = 0.0005). Repeated surgery after recurrence of MFH could cure 40.9% of the head and neck patients and 80.7% of the extremity patients. Conclusion Inadequate resection of head and neck MFH in initial surgery is associated with a high incidence of local recurrence, which is always correlated with worse prognosis. Repeated surgery for recurrent head and neck MFH is not as effective as for recurrent extremity MFH. Therefore, we suggest that the initial surgery for head and neck MFH should be as radical as allowed to avoid a possible local recurrence. Chin Med J 2000; 113(6): 532-535

Objective To investigate the epidemiological and clinical manifestations of endemic arsenism, fluorosis and arsenic-fluoride poisoning caused by drinking water. Methods A total of 102 wells with high arsenic and fluoride level in water were selected. The residents were investigated before and after intervention for prevention and treatments and compared with controls. Results The residents' state of illness in the endemic area showed that arsenic and fluoride had independent actions respectively in their main clinical manifestations. In the endemic area, puberty of the children was retarded. And there was an obvious entanglement in the extremity microcirculation. More abnormal findings were found in electrocardiogram (ECG) and electromyogram (EMG). Birth weight of the babies was less than that of the controls. Patients with skin tumors and carcinoma of the esophagus were found prelavent. Improvement occurred in 81.7% of arsenism patients and no new case was found one year after the quality of the water was improved. Conclusions Arsenic and fluoride are able to produce toxic effects independently at levels of 0.1 mg/L or more of arsenic and 1 mg/L or more of fluoride. It suggests each of arsenism, fluorosis or arsenic-fluoride poisoning is a systematic disorder. After one year of drinking reformed water the clinical manifestations were improved.

Purpose To review the recent developments in asthma research in China, presenting the background of further asthma research and promoting academic exchanges between Chinese and foreign respirologists. Data sources A literature search was conducted using 5 authoritative journals covering the years 1994 -1998. Study selection Sixty-seven of 238 asthma-remated original articles published between the years 1994 -1998 were selected to reflect the recent developments in asthma in China. Data extraction The papers reviewed pertain mainly to the epidemiology, genetics, pathogenesis, prevention and treatment of asthma. Results Since 1993, the hot topics in asthma research in China have been pathogenesis, prevention and treatment. There has been relatively less investigation into the genetics of asthma in China. An epidemiological survey of asthma has been conducted in parts of China and was reviewed. Conclusions More and more attention has been paid to the study of asthma during the last five years in China. The prevalence of asthma has increased in recent years. The study of the pathogenesis of asthmatic airway inflammation has made further progress, which will help the management and treatment of asthma. The treatments for asthma, including herbal medicine, have been explored and the clinical efficacy of inhaled corticosteroids has been established. Chin Med J 2000; 113(6): 483-489