1999年 · 第112卷第08期

OBJECTIVE To study protective immunity afforded by murine immunization with DNA vaccine of Schistosoma japonicum (S. japonicum) as measured by reduction in worm burden and host antibody, cytokines. METHODS DNA vaccine pCD-Sj32 was constructed, identified and expressed. pCD-Sj32 could induce substantial protective immunity against infection of S. japonicum in BALB/c mice. The best efficacy can be produced with one injection of 100 micrograms DNA into the quadriceps muscle, combined with challenge for 8 weeks after immunization. T lymphocyte subsets of CD8+, IL-2. TNF and IFN-gamma of experimental animal could play important roles in regulating immune functions of schistosomiasis. RESULTS High titre of specific antibody IgG could be induced by vaccinated with pCD-Sj32, and antibody can mediate macrophage to produce ADCC effects in vitro. CONCLUSIONS pCD-Sj32 may represent a new approach to developing subunit vaccine.

OBJECTIVE To find out relationship between the in vitro schistosome egg antigen (SEA) stimulated IFN-γ and IL-4 mRNA expressions and the in vivo SEA elicited granulomatous responses, the transcriptions of IFN-γ and IL-4 gene were investigated in the spleen of BALB/c mice infected with Schistosoma japonicum (S. japonicum). METHODS Spleens were removed at 0, 3, 5, 8, and 10 and 12 weeks after infection and the spleen cells were incubated in the presence of SEA. The extracted RNA was analyzed for IFN-γ and IL-4 mRNA by reverse transcription PCR (RT-PCR). Newly-formed liver granulomas were measured. RESULTS The study revealed that no detectable IFN-γ and IL-4 mRNA RT-PCR products were found in SEA treated spleen cells from uninfected, or 3-week infected mice, whereas IL-4 mRNA was found to be expressed in 5- and 8-week infected mice, and an appreciable enhanced expression of IL-4 mRNA was observed in SEA stimulated spleen cells at 8-week infection than at 5-week infections. However, SEA could not induce IFN-γ and IL-4 mRNA transcription in 10- and 12-week infected mice, indicating the modulated expression of IFN-γ and IL-4 mRNA. CONCLUSIONS The significant changes of IL-4 mRNA expression in SEA stimulated spleen cells during S. japonicum infection were coincident with SEA elicited granuloma formation and modulation in vivo.

OBJECTIVE Four B and Th cell epitopes were selected from conservative domain of Plasmodium falciparum antigens to construct two groups of chimeric malaria DNA vaccines with different configurations and their antigenicities were studied. METHODS The partially synthesized oligonucleotide was annealed, PCR amplified and cloned into a mammalian cell expression vector. By using a pair of isocaudamers on the vector, different single copies of B epitopes were multiplied and were tenderly stringed into two groups of chimeric DNA vaccine with different configurations. BALB/c mice were immunized with these DNA plasmids by either intramuscular or intradermal injections. RESULTS The antisera from the immunized mice tested by ELISA showed that only the configuration which had a single copy of universal T helper cell epitope, CS. T3, located at the C terminal of the multi-copy B cell epitopes induced a high antibody response. The T helper cell epitope at any other position of the peptide, or the double T helper cell epitopes configured with the B cell epitopes did not enhance antibody response, and some configurations even decreased the humoral response to a B cell epitope. CONCLUSIONS This study demonstrated that both combination and configuration of the epitope may affect the antigenicity of a chimeric multiple antigen.

OBJECTIVE To construct and evaluate a recombinant multi-epitope, multistage malaria vaccine candidate expressed in Escherichia coli (E. coli). METHODS A hybrid gene (HGF) encoding several putative immunodominant T or T/B epitopes from MSP-1, MSP-2, Pf155/RESA of Plasmodium falciparum (P. falciparum) and two immune-stimulating epitopes from interleukin-1 and tetanus toxin was synthesized. Two copies of HGF and a copy of gene encoding Pattaroyo's Spf66 were connected together to construct a sandwich hybrid gene HGFSP. The gene was cloned into an expression vector pWR450-I for production of a fusion protein with beta-galactosidase. Efficacy of this vaccine candidate in inducing specific immunity against malaria parasites was evaluated. RESULTS Immunization of different species of animals with purified recombinant peptide showed that the peptide was able to induce remarkable antibody response to the immunized peptide as well as falciparum malaria parasites. The epitopes included in the construct could induce antibodies against the intact parasite proteins as demonstrated by western blotting, indicating the epitopes retained their antigenicity in the new peptide construct. Antibodies from animals immunized with recombinant HGFSP peptide exhibited good ability in inhibition of the in vitro growth of malaria parasites, augmentation of phagocytosis of the parasites or infected RBC by phagocytes, and facilitation of antibody dependent cell mediated cytotoxicity to the cultured malaria parasites. CONCLUSIONS The recombinant peptide seems to be a potential candidate which is valuable for further investigation.

OBJECTIVE To clone a surface protein encoding gene from Leishmania major Abdou parasites. METHODS Using Trypanosotidae cruzi (T. cruzi) amastin DNA sequence as a reference, computer search was done on Genbank and dbEST data bases with BLASTN path. A Leishmania major Abdou DNA library has been established and screened by in situ colony hybridization. RESULTS No homology sequence to T. cruzi amastin was found in Genbank, but a 309 nt DNA fragment from Leishmania major (L. major) existed in bEST. Leishmania major Abdou DNA library was screened using specific probes synthesized according to 309 nt DNA sequence of T. cruzi amastin gene, and full-length coding sequence for Leishmania major Abdou amastin was cloned. The coding sequence consisted of 552 nt, and translated into 183 amino acid residues. The homology is 23.5% at amino acid sequence level betweenLeishmania major Abdou and T. cruzi amastins. CONCLUSIONS We have cloned the full length amastin coding DNA for Leishmania major Abdou.

OBJECTIVE To investigate the relationship of an insertion/deletion (I/D) polymorphism of the angiotension-converting enzyme (ACE) gene to obstructive sleep apnea syndrome (OSAS) patients and the control subjects. METHODS Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers flanked the polymorphic region in intro 16 of the ACE gene. RESULTS OSAS patients had significantly higher frequencies of I/I genotype and insertion allele of the ACE gene as compared with the control subjects in Chinese population. The OSAS patients with I/I genotype had significantly longer apnea time, lower minimum SaO2 and greater AHI than the OSAS patients with I/D genotype. CONCLUSIONS These results indicate that the I/I genotype and I allele are a risk factor for OSAS in Chinese.

OBJECTIVE To investigate the effects and mechanism of Wilms' tumor (WT1) antisense oligonucleotides (AS-oligomers) on proliferation and apoptosis in myeloid leukemia cell lines. METHODS K562 and HL-60 cells were cultured in presence of WT1 oligomers. Both cell lines express WT1 gene with no p53 protein expression. Cells growth, apoptosis and expression of WT1, bcl-2 genes were analysed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylmetrazolium bromide (MTT) colorimetric assay, flow cytometry and reverse transcription-polymerase chain reaction (RT-PCR) methods. RESULTS WT1 antisense oligonucleotides inhibited cellular proliferation of K562 cells and the effect was concentration-dependent. When cultured at concentration of 200 μg/ml oligomers, growth inhibition was 46.2% for antisense oligonucleotide cultivated group and 28.1% for sense oligonucleotide cultured group (P = 0.008) respectively. WT1 antisense oligonucleotide can induce apoptosis of K562 and HL-60 cells. Percentages of apoptotic cells in antisense oligonucleotide and sense oligonucleotide treated groups were 30.88% versus 13.62% for K562 cells and 40.15% versus 4.23% for HL-60 cells. However the growth of HL-60 cells and expression of bcl-2 gene were unaffected. CONCLUSIONS The WT1 gene is related with proliferation and apoptosis of leukemic cells. Effect of anti-apoptosis may be independent of the cellular p53 status and bcl-2 expression. WT1 gene may play an important role in leukemogenesis.

OBJECTIVE To examine the effects on semen and sperm quality of workers after a short and long term exposure to benzene, toluene, and xylene. METHODS The semen and blood of 24 married workers exposed to benzene, toluene, and xylene from shoemaking, spray painting, or paint manufacturing factories were collected. The concentration of benzene, toluene, and xylene in the blood and semen was determined by using headspace chromatographic method. Routine sperm test was carried out and acrosin activity detected. RESULTS The results showed that benzene, toluene, and xylene were found in the blood and semen of some ex-workers in a working environment where the air concentration of benzene, toluene, and xylene exceeded the maximum allowable concentration (MAC). This result was not found in workers of the control group. There were also some effects on the quality of semen in the exposed workers. For example, the percentage of semen with liquefaction time exceeding 30 minutes increased. The sperm vitality, motility and acrosin activity decreased. At the same time, there were a positive correlation between liquefaction time and the level of toluene in semen, and a negative correlation between sperm vitality, sperm activity or acrosin activity and working history. CONCLUSIONS The results suggested that the mixture could affect the quality of semen and sperm, which might be the main reason of the abnormal pregnancy outcome among the wives of workers exposed to benzene, toluene, and xylene. Further studies are, however, required to confirm these findings.

OBJECTIVE To review the indications, operative methods and postoperative management of the "elephant trunk technique", and to report two cases of DeBakey type I aortic dissection treated with the "elephant trunk technique". METHODS Two cases of DeBakey type I aortic dissection were operated with selective cerebral perfusion via the right subclavian artery. At the first stage, a tubular dangling aortic graft prosthesis ("elephant trunk") was inserted into the distal aorta while replacing the ascending aorta and aortic arch. The distal elephant trunk prosthesis was then used at the second stage involving the replacement of the sections of the distal aorta via a left-sided thoracotomy. RESULTS The two operations were successful. Ultrafast computed tomograph (UFCT) showed that the two patients were cured after the first stage operation, and the second stage procedure could have been avoided. CONCLUSIONS The "elephant trunk technique" is a multiple stage approach in the treatment of extensive aneurysmal diseases of the aorta. The procedure is indicated for patients who have combined diseases of both ascending aorta plus aortic arch segments and descending aortic aneurysm. It can also be used for patients with DeBakey type I aortic dissection. Some patients can be cured after the first stage operation.

OBJECTIVE To study the expression of vascular endothelial growth factor (VEGF) in different parts of heart during early acute myocardial ischemia. METHODS The expression of VEGF in control and study group in rats was performed with the Strept Avidin-Biotin-Peroxidase Complex (SABC) method. RESULTS A rapid expression of VEGF in ischemic areas was observed 1 hour after the ligation of rat left anterior descending (LAD) coronary artery, and in peri-ischemic and non-ischemic areas 3 hours after ischemia. The grade of expression of VEGF increased with the continuation of myocardial ischemia, the positive myocytes of SABC-VEGF staining mainly localized in peri-ischemic areas 5 hours after ischemia. No expression of VEGF in control group was found. CONCLUSIONS The expression of VEGF may be up-regulated in rapid and continuous manner with characteristic spatial and temporal kinetic during early acute myocardial ischemia.

OBJECTIVE To analyze the clinical feature, efficacy of treatment and prognosis in familial benign chronic pemphigus (FBCP). METHODS Sixty-nine cases of FBCP were retrospectively analyzed. RESULTS The ratio of male to female is 3.93:1 in 69 patients (55 males, 14 females). The mean age at the onset was 29.09 years (3-60 years). There was familial history in 27 families in all of the cases. The lesion usually involved in genital area, neck, axillae and popliteal fossa. Erythemas and vesicles on the soles were seen only in 1 case. Histopathologically 44 cases had special features of FBCP, and immunopathologically 8 cases were direct immunofluorescence (DIF) negative, in which one case had C3 linear deposition along dermoepidermal junction. The combined regimen was more effective. The low-dose X-ray could improve the effect. CONCLUSIONS The disease is transmitted as an irregular autosomal dominant trait. The condition in males is more frequent than that in females, probably owing to the different level of female hormone in both sexes. Our patients have the same clinical features as those reported in the literature, but the erythema, vesicle lesions on sole have not been documented in the literature. The combined therapy should be adopted in this condition.