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Objective: To observe the in vitro expression of DNA vaccine (recombinant eukaryotic expression plasmid pcDNA3-TspE1) encoding a Mr 31,000 antigen of Trichinella spiralis in Chinese hamster ovary (CHO) cells and analyze the antigenicity of the products expressed., Methods: The recombinant plasmid pcDNA3-TspE1 was transfected into CHO cells by using cationic lipids (Lipofectamine 2000). The positive cell clones were screened by the selective antibiotic G418. The expressed products were identified by RT-PCR, IFAT, SDS-PAGE and Western blotting., Results: The results of RT-PCR amplification showed that there was one band with 876 bp in CHO cells transfected with pcDNA3-TspE1 and no any bands in CHO cells transfected with the empty plasmid pcDNA3. The IFAT demonstrated that the pcDNA3-TspE1 transfected CHO cells reacted with sera from mice immunized with the recombinant fusion protein and from mice infected with T. spiralis, the bright yellow green fluorescence staining appeared in the transfected CHO cells. The pcDNA3 transfected and un-transfected CHO cells exhibited as orange color. The results of SDS-PAGE showed that there was one band with Mr 31,000 in culture supernatant of CHO cells transfected with pcDNA3-TspE1. Western blotting confirmed that the band with Mr 31,000 could be recognized by sera from mice immunized with the recombinant fusion protein, from rabbits immunized with T. spiralis muscle larval soluble antigens, from mice infected with T. spiralis and from patients with trichinellosis. Conclusion The mammalian CHO cells were transfected by the recombinant plasmid pcDNA3-TspE1, and the TspE1 gene of T. spiralis was expressed in the transfected CHO cells. The proteins expressed are secreted into cell culture supernatants and show the antigenicity of T. spiralis.

We measured the effects of exposure to volatile compounds produced by host plants on the rate of capture of male Spodoptera exigua using synthetic sex pheromones. Exposure to volatile compounds stimulated strong electroantennographic responses of male S. exigua. The behavioral responses of male moths to combinations of sex pheromone and volatile compounds were tested in wind tunnel experiments. When lures were baited with synthetic sex pheromone plus benzaldehyde, phenylacetaldehyde, (Z)-3-hexenyl acetate, or linalool, respectively, the landing rate of S. exigua males was increased by 101.4%, 79.6%, 60.6%, and 34.3%, respectively, compared to sex pheromone alone. In field tests, traps baited with either pheromone + (E)-2-hexenal, pheromone + phenylacetaldehyde, pheromone + (Z)-3-hexenyl acetate, or pheromone + (Z)-3-hexenol enhanced moth catches by 38.8%, 34.6%, 24.6%, and 20.8%, respectively compared to traps baited with pheromone alone. In a second field experiment, more S. exigua males were trapped with a combination of a synthetic sex pheromone blend and several individual host plant volatiles compared to synthetic sex pheromone alone. These results suggest that some host plant volatiles enhance the orientation response of S. exigua male moths to sex pheromone sources.

The endothelial cell line ECV304, derived from human umbilical cord and identified to be susceptible to dengue virus type 2 (DEN-2) infection, was used to study the molecular mechanism of DEN-2 binding to endothelial cells. DEN-2 was found by virus overlay protein-binding assays (VOPBAs) to bind to three ECV304 cell membrane proteins with molecular masses of 29, 34 and 43 kDa. Only a single protein of 29 kDa was observed when VOPBAs were carried out using preparations of trypsin-treated ECV304 cells. Pre-incubation of live ECV304 cells in culture or cell membrane proteins in modified VOPBAs with the recombinant DEN-2 envelope glycoprotein (rEgp) inhibited DEN-2 infection and blocked virus binding to the three proteins identified. These results indicate that DEN-2 rEgp could bind to three proteins on the surface of ECV304 cells. This virus-cell interaction may be associated with the receptor complex specific for DEN-2 infection of endothelial cells.

Objective: To assess the efficacy of medial wedged proximal tibial osteotomy for treating knee osteoarthritis with varus deformity., Methods: From July 1996 to September 1999, 19 patients with knee osteoarthritis accompanied by varus deformity were treated by medial wedged proximal tibial osteotomy combined with internal fixation. Full-length anterior-posterior radiographs were taken preoperatively, 8 weeks and 2 years postoperatively. The parameters including the femorotibial angle, the tibial angle, the femoral angle, the femoral condyle-tibial plateau angle, and the medial joint space, were measured from these radiographs. The function of knee was evaluated according to the 100-point rating scale standard of knee., Results: The mean postoperative score had been significantly improved from 48.6 +/- 16.6 points to 81.7 +/- 14.8 points after 2 years of operation. The medial joint space had been increased from 2.2 +/- 1.6 mm to 4.9 +/- 1.5 mm and the femoral condyle-tibial angle had been decreased from 7.4 degrees +/- 3.1 degrees to 1.7 degrees +/- 3.1 degrees. There were complications in 3 cases: 2 cases of superficial wound infections and 1 case of intra-articular fracture. There were no delayed union and recurrence of varus deformity., Conclusion: Medial wedged proximal tibial osteotomy combined with internal fixation provides an efficacious approach to treat knee osteoarthritis with varus deformity.

The full-length envelope glycoprotein gene of dengue virus type 2 was cloned using an RT-PCR method from the infected C6/36 cells and inserted into pPICZaB vector. The recombinant plasmid was integrated into Pichia pastoris by electroporation and the expressed product was identified by SDS-PAGE and Western blotting. High-level secreted expression was performed by determining the Mut(+) phenotype and screening multi-copy integrants in the recombinant yeast cells. A recombinant protein with a molecular size of approximately 69 kDa was secreted into the supernatant from the yeast cells when induced with methanol. The expressed supernatant was able to bind with mouse polyclonal antibody or E-specific monoclonal antibody of dengue-2 virus. Purified E-poly (His)-tagged fusion protein was obtained from the expressed product by passing through a metal-chelating affinity chromatographic (MCAC) column. The results of Western blotting and solid-phase ELISA using dengue virus antibodies indicated that the purified recombinant E glycoprotein retained its antigenicity. High-level production of the recombinant E protein up to 100 mg/l indicates that P. pastoris is an efficient expression system for dengue virus full-length envelope glycoprotein.

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

The ID90 or ID50 values of acyclovir for the herpes simplex virus strains isolated in VGH-Taipei were determined by plaque reduction method. Twenty HSV isolates of 1980's (1980-1985) and thirty of 1990's (1990-1995) were subjected to plaque reduction assay for susceptibility test to acyclovir. There were fifteen HSV isolates of 1990's whose ID90 were higher than those of 1980's, indicating a trend of more acyclovir resistant isolates in 1990's.

From 1977 to 1993, 15,189 throat swab samples were received for isolation and identification of influenza virus in the Clinical Virology Laboratory, Veterans General Hospital-Taipei. Most of the samples came from the Pediatric Department. There were 634 identified strains of the influenza virus; the successful isolation rate was 4.17% in average/year. Among these isolates, 56.3% (357/634) were influenza B; 12.1% (77/634) were influenza A/H1N1 and 28.1% (178/634) were influenza A/H3N2. About 3.5% (22/634) were classified as flu-like agents because of no reaction with available monoclonal antibodies. In recent years, reverse transcriptase polymerase chain reaction (RT-PCR) was established here to re-evaluate these virus stocks. This method can provide rapid diagnosis method to identify influenza A/H1N1, A/H3N2 and B. Further, the RT-PCR method and sequencing of amplified DNA could be used to see the variation of virus isolates which were recirculated or which reappeared in the Taipei area.

A clinical isolate of influenza virus A/H3N2 from a one-year-old boy with pharyngitis was examined by using RNA-polymerase chain reaction (PCR) for amplification of viral cDNA and subsequent DNA sequencing with asymmetric PCR. Since antigenic drift has been found in recent A/H3N2 isolates, this strain was compared with A/Shanghai/24/90 and other A/H3N2 strains, collected at the Centers for Disease Control and Prevention (CDC) in Atlanta, GA, USA. It was found that the steady changes of amino acid at location 190 and 262 of HA1 region were very similar to some recent isolates. This 1989 isolate may be the origin of a new influenza virus A/H3N2 variant.

A total of 2,750 strains of beta-hemolytic streptococci was isolated from 10, 510 throat swabs collected from school children in the Taipei area. Most of them were classified as group A (61%) and group G (34%), and about 5% belonged to other groups or unclassified strains. 1, 772 strains of beta-hemolytic streptococci isolated from healthy school children, and 69 strains from sick school children were grouped by the Lancefield precipitin test, fluorescent antibody technique and/or bacitracin paper disk method. A satisfactory correlation (over 90%) was obtained by the latter 2 methods, when compared with the results of the Lancefield technique. The occurrance of false negative or false positive was only 1 or 5%, respectively.

From 1967-1973, a total of 54 strains of Mycoplasma pneumoniae was isolated from patients suffering from different acute respiratory diseases, with an average positive isolation rate of 4.7%. Most mycoplasmas were isolated from patients aged 40-60, and with pneumonia of primary atypical pneumonias. The highest frequency of isolation was found in sputum collected 4-8 days after onset of illness. Colony formation on PPLO medium usually occurred 7-12 days after incubation. Serological tests were methods of choice for diagnosis of mycoplasmal pneumonia. In the 6 years period, 163 patients were diagnosed: 74 were positive only by metabolic inhibition test (MIT), 55 were positive only by cold agglutination test (CAT), and 34 gave positive by both tests. Of the above 2 tests, the CAT is nonspecific, but the MIT appears to be more sensitive and specific. Of the 94 sera positive by MIT, 42 (48.2%) were also positive by CAT; of those negative by MIT, 45 of 507 (8.8%) were positive by CAT. Of 45 sera with positive mycoplasma isolation, 37 (82.2%) were also positive by MIT, but only 22 (48.9%) showed the rises of CAT titers. Clinical features of mycoplasmal pneumonia were almost similar to those described by the other investigators. The chief symptoms were fever, coughs, chills, rales, malaise, sore throat headache and chest pain. The sedimentation rate of erythrocytes was accelerated. White count was normal in most cases. Both leucocytosis and leucopenia were found in 10% of the cases. Seasonal variation in incidence of mycoplasmal pneumonia was not obvious, however the lowest incidence occurred during summer. A roentgenogram of the chest was necessary for diagnosis of mycoplasmal pneumonia, and the lung infiltration was mainly located on right side (57.1%), segmentally, and limited to one lobe, especially the lower lobe.