Volume 109  ·   Issue 12  ·  1996

The ability to perform complex cardiac operations has been propelled by steady improvements in myocardial protection. Techniques used to allow surgery on the heart have included normothermic arrest, hypothermic fibrillatory arrest without cardioplegia, crystalloid cardioplegia, blood cardioplegia, and finally antegrade and retrograde delivery of blood cardioplegia solutions.

Chlamydia trachomatis infection, an important cause of urethritis, cervicitis and pelvic inflammatory disease, is one of the most common sexually transmitted diseases (STDs) in some western countries.

OBJECTIVE To study the clinical characteristics of myasthenia gravis (MG) with thymoma and the effect of tracheostomy at the early stage after operation. METHODS Thymoma excision and selective tracheostomy were performed on 46 patients with MG from March 1983 to December 1994. RESULTS There were 15 patients with benign thymomas and 31 patients with malignant thymomas. MG crises were seen in 52.2% of patients postoperatively, most in type IIb and III. The mortality of in-patients after operation was 10.9%. Thirty-nine patients with thymoma were followed up for 6 months to 12 years after being discharged from hospital. The MG symptoms were relieved in 33.3%, improved in 20.5% and unchanged in 2.6% of patients. 38.5% of patients died of the disease. CONCLUSIONS The characteristics of MG with thymoma are, more severe condition of the patient, rapid advance, and more MG crises before and after operation. The perioperative mortality from MG with thymoma is higher and its prognosis is unfavourable. It is very important to treat severe cases of MG with thymoma by tracheostomy with thymoma excision at the early stage after the operation. This is an effective method to prevent and treat MG crises as well as to lower the perioperative mortality.

OBJECTIVE To evaluate the clinical and radiological findings in diagnosing spontaneous malignant transformation of fibrous dysplasia. METHODS Fifteen cases of sarcomatous transformation proved by operation and pathological examinations were found in a group of 356 patients with fibrous dysplasia, and their radiological manifestations were retrospectively studied. The 15 cases included 8 osteosarcomas, 5 fibrosarcomas and 2 chondrosarcomas. All the 15 patients were known to have long-standing fibrous dysplasia, but no radiation therapy was ever received. Eleven patients had polyostotic fibrous dysplasia and 4 had monostotic type. RESULTS Malignant transformation most frequently occurs in the cystic expansive lesion of the long tubular bone. Pains, swelling and late appearance of a bony mass are the main clinical manifestations. The early radiological features of sarcomatous transformation in fibrous dysplasia are moth-eaten or cystic areas of osteolysis located in the involved bone. The cortical destruction and gradual formation of a soft tissue mass that contains tumor-bone are highly suspicious of osteosarcomatous transformation, while ring-like and spotty calcification in the tumor matrix is indicative of chondrosarcoma. Fibrosarcoma usually shows simple osteolytic destruction. CONCLUSIONS According to the clinical radiological findings, patients of sarcomatous transformation can be detected in the early stage. These radiological findings may be used as a clue for differentiating various kinds of sarcomatous transformation.

OBJECTIVE To study the result of one staged bilateral total knee arthroplasty (TKA) operation under epidural anesthesia on patients with severe rheumatoid arthritis (RA). METHODS From April 1987 to December 1992, simultaneous bilateral TKA was performed on 45 patients (90 knees), including 41 patients with RA, 3 with juvenile RA, and 1 with Sjogren syndrome. The mean follow-up period was 63 months. RESULTS Improved function and pain relief were noted in all patients. There were no wound healing problems. Thrombophlebitis was observed in few cases. Late infection rate was 5.6% (5 knees) and aseptic loosening was revised on 5 knees. CONCLUSIONS Simultaneous bilateral TKA is not only a procedure of low cost, saving blood, reducing anesthesia risk, drugs' side effect and hospitalization, but also facilitates early rehabilitation. Except for late infection, there is no increase in complications.

OBJECTIVE To investigate the relationship between high incidence of adverse dapsone reactions in acquired immunodeficiency syndrome (AIDS) patients and slow acetylate phenotype or low plasma/lymphocyte glutathione level of these patients. METHODS Twenty-one cases of advanced AIDS patients (CD4<200/microliter) were involved in this study, all Europeans except one black, were acetylate phenotyped via analysis of caffeine metabolites, named 5-Acetylamino-6-formylamino-3-methyluracil, 1-Methylxanthine and 5-Acetylamino-6-amino-3-methyluracil, in human urine collected 2 hours after a cup of caffeine-spiked coffee and their plasma/lymphocyte glutathione concentrations were determined, by high performance liquid chromatographic method. RESULTS Of the 21 AIDS patients, 15 are slow acetylators, accounting for 74.8%. One of 6 rapid acetylators has adverse dapsone reactions, acounting for 17%, compared with 46% for slow acetylators (7/15). The concentrations of glutathione in plasma/lymphocyte (6.97±0.95 μmol and 28.75±2.78 nmol/mg protein) in AIDS patients with adverse dapsone reactions are significantly lower than those (10.90±1.45 μmol and 32.15±2.21 nmol/mg protein) of AIDS patients without adverse dapsone reactions, and also than those (11.85±1.83 μmol and 33.76±2.32 nmol/mg protein) of health controls. CONCLUSIONS Slow acetylators, which lead to accumulation of toxic dapsone metabolites and those subjects who are lower in glutathione level in plasma/lymphocyte because of certain kind of diseases as advanced AIDS are risk population of adverse dapsone reactions. Routinely determining human acetylate phenotype status might be helpful in adjusting and modifying dapsone dosage regimen.

OBJECTIVE To evaluate the efficiency of respiratory muscle training programs in pilots. METHODS Twenty-four male pilots were divided into two groups. The training group (12 pilots) underwent respiratory strengthening training programs besides routine physical exercises. The other 12 pilots in the control group only did routine physical exercises, but the training time was the same in these two groups. Before and after training programs in the two groups, the respiratory muscle functions were examined. RESULTS 24 pilots in these two groups completed training programs within four weeks. The pilots in the training group got improvement of respiratory muscle functions which was much better than those of the control group. CONCLUSIONS It suggests that the strengthening training programs of respiratory muscles can improve and strengthen the respiratory muscle functions in pilots.

OBJECTIVE To investigate the time window for oxidative stress occurred in myocardial tissue and associated with reperfusion. METHODS Thirty nine conscious rabbits were subjected to 0.5 hours (h) of myocardial ischemia and reperfusion for 0 h, 6 h, 24 h and 72 h, respectively, and nine rabbits served as controls. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-px) and myeloperoxidase (MPO), and contents of GSH and malondyaldehyde (MDA) were measured in myocardial tissues taken from ischemic non-necrotic area (INNA), ischemic necrotic area (INA) and non-ischemic area (NIA), respectively. RESULTS The antioxidant status of INNA was weakened at 6th h, 24th h, and 48th h of reperfusion. Activities of Mn-SOD and Cu-Zu-SOD returned to normal value at 72nd h of reperfusion, but GSH-px activity and GSH content remained in lower value. MDA content had a marked increase at 6th h, 24th h, 48th/h and 72nd h of reperfusion. MPO activity had a progressive increase after reperfusion, with its peak value at 48th h, and PMN accumulation occurred mostly in necrotic zone and its outer board zone. A mild oxidative stress also occurred in non-ischemic tissue, but without obvious neutrophils infiltration. CONCLUSIONS The time window for oxidative stress associated with myocardial ischemia and reperfusion lasts for at least 72 h, and PMN infiltration is one of the most important factors of delayed myocardial reperfusion injury.

OBJECTIVE To clarify the relationship between c-myc gene amplification and expression in human hepatocellular carcinoma (HCC) tissue. METHODS Levels of amplification, transcription and P62 myc expression of c-myc gene in tumor tissues and corresponding non-tumor tissues were systematically studied using Dot blot hybridization, in situ hybridization and immunohistochemical technique, respectively. The 14 pairs of specimens were resected from patients with HCC. RESULTS The amplification of c-myc gene was not found in tumor and non-tumor tissues. Overexpression of c-myc mRNA transcription was detected in 11 tumor tissues and 10 non-tumor tissues. The positive rate of P62 myc was 85.7% (12/14) in tumor tissues and 92.9% (13/14) in non-tumor tissues, respectively. A close correlation was noticed between c-myc mRNA and P62 myc expression. The results suggested that c-myc gene overexpression was not related to its amplification. CONCLUSIONS The overexpression of c-myc mRNA and gene product without amplification may be characteristic in HCC.

OBJECTIVE In order to elicit immune response to hepatitis E virus (HEV) with the method of direct injection of naked DNA. METHODS The gene encoding the structural protein of pORF3, a Chinese strain of HEV, was cloned into the eukaryotic expression plasmid pSVL. The resulted plasmid pSVL-HEV ORF3 was used as HEV DNA vaccine, to inoculate Balb/c mice intramuscularly with a dose of 100 micrograms. Mice injected with empty pSVL DNA served as control. RESULTS After 1-2 times inoculation, twelve of 16 mice inoculated with pSVL-HEV ORF3 had anti-HEV IgG seroconversion. pSVL-HEV ORF3 was still detectable in the muscle of the inoculated mice 18 days after the injection, by the method of PCR. None of the control group had a detectable level of anti-HEV IgG. It is also found that the humoral immune response to HEV induced by DNA vaccine could be boostered by HEV recombinant fusion protein. CONCLUSIONS Our present study demonstrated that nucleic acid vaccine is able to prime a specific humoral immune response to HEV in mice.