Objective To discusse the mechanism and clinical significance of bradycardia -hypotension phenomenon which is caused by vagal reflex during and after the RFCA and present the experience of using appropriate measures to decrease the incidence of this situation. Methods The patients who were suffering from tachyarrhythmias and treated by RFCA were divided into two groups. The groups were as follows:148 patients who were not taken special measures in the early stage were selected in control group;1 540 patients who were taken measures to prevent vasovagal reflex were selected in observation group. Result During the RFCA, the incidence of bradycardia -hypotension phenomenon in control group was 13.5% (20/148), the incidence of bradycardia-hypotension phenomenon in observation group was 5.0%(77/1540) (<0.01) .Conclusions The incidence of bradycardia-hypotension phenomenon caused by vagal reflex during the RFCA is related to catheter irritation to the heart,pressure on the vessels and hypovolemia. The incidence of this phenomenon can be decreased obviously by some measures,such as non-restricted diet before RFCA,discretion rehydration during and after the RFCA and hemostasis with appropriate force after extubation. The key to rescue patients successfully are early detection and timely processing.

Objective To evaluate the immune effects of virus-like particles ( VLPs) of VP1 pro-teins derived from norovirus GⅠ. 1 and GⅡ. 4 genotypes expressed in Hansenula polymorpha expression sys-tem. Methods SDS-PAGE and Western blot assay were performed to detect the purity of GⅠ. 1 and GⅡ. 4 VP1 proteins after purification. Morphologies of the recombinant VLPs were observed under transmission electron microscopy ( TEM) . Sizes and distributions of the VLPs were analyzed by dynamic light scattering analyzer. BT50(50% of blocking titer) was detected by HBGA (histo-blood group antigen) blocking assay in BALB/c mice immunized with different regimens. Results SDS-PAGE analysis of the purified recombinant GⅠ. 1 and GⅡ. 4 VP1 proteins showed that their purity were greater than 90%. Western blot assay con-firmed the specific bands of VLPs. TEM images showed that the sizes of purified GⅠ. 1 and GⅡ. 4 VP1 VLPs were at a mean diameter of 30-50 nm with clear border and high homogeneity, which was similar to that of wild virus. BT50 significantly increased in the groups, in which Al( OH) 3 was used as adjuvant. Con-clusion Animal studies have shown that administration of GⅠ. 1 and GⅡ. 4 VP1 VLPs in the presence of Al( OH) 3 induces detectable HBGA-blocking antibody, indicating that GⅠ. 1 and GⅡ. 4 VP1 VLPs are promising candidates for norovirus vaccine.

Objective To understand serotype and fimbriae-genotype of B. pertussis vaccine strains and isolates from different periods in China. Methods Serotype of eighty isolates and three vaccine strains were determined using anti-fim2 and fim3 monoclonal antibodies compared with polyclonal antisera. Fim2 and fim 3 genes were amplified by PCR and the amplified products were sequenced and analyzed . Results The serotype of three vaccine strains and all isolates but only one tested by the slide agglutination and micro-plate assay of anti-fim2 and fim3 monoclonal antibodies were the same in comparison with that of the slide agglutination of polyconal antisera. In this study, seventeen isolates and vaccine strains CS and P3S10 were fim2&3 serotype, and forty-eight isolates were tim2 serotype while fifteen isolates and vaccine strain 18530 were fim3 serotype. The predominant serotypes were fim2 and fim2&3 before Expanded Program on Immuni-zation in 1978, while the find became the most popular serotype after nation-wide pertussis vaccination in China. The fim2-1 and fim3-A genotype was the most common type, which was identified in 92.5% and 95.0% of the isolates, respectively. The genotype of vaccine strain 18530 was fim2-2 and fim3-A while oth-er vaccine strains were fim2-1 and fim3-A. The isolates contained fim3-B and fim3-D subtypes were found since 2000. These data indicated that the serotype and fimbriae genotype of B. pertussis isolates have been changed for immune environment of national-wide pertussis vaccination in China. Conclusion The validity and specificity of anti-fim2 and fim3 monoclonal antibodies have been validated for serotyping of B. pertussis strains. The information of serotype and fimbirae genotype of B. pertussis vaccine strains and isolates from dif-ferent time periods have been obtained. These data can facilitate the studies on quality control of vaccine strain, epidemiology and the evolution of B. pertussis in China.

Objective To establish a rapid,accurate,specific quantitative assay for detecting B.pertussis,and apply to clinical diagnosis.Methods According to the specific sequence of B.pertussis IS481 gene,the primers and the fluorescence probe were designed and synthesized.Then a fluorescence quantitative PCR for detecting B.pertussis was developed.The specificity,sensitivity and reproducibility of the method were evaluated.255 specimens including 225 nasopharyngeal swabs from suspected pertussis patients and 30 normal nasopharyngeal swabs were detected by fluorescence quantitative PCR.Results A rapid specific quantitative method for detecting B.pertussis was established.The standard curve of the method indicated that there was a good linear relationship between the CT value and the template concentration with the correlation coefficient being 0.998.The linear range of the system was from 102 to 108 copies/μl and the minimum was 102 copies.It had a high sensitivity and good specificity.The intra.and inter-assay coefficients of variation were 5.78%-16.7% and 8.25%-14.9% respectively.The fluorescence quantitative PCR identified 41 positive results for specimens from suspected pertussis patients and results of 30 normal specimens were all negative.Conclusions The method can quantitatively detect the B.pertussis rapidly with high sensitivity and specificity,it can be applied to clinical diagnosis.

Objective To establish the enzyme-linked immunosorbent assay (ELISA) methods for the quantitative determination of IgG antibodies against diphtheria (DT) and tetanus (TT).MethodsPurified diphtheria toxiod and tetanus toxoid were respectively used as the coating antigens,the human-derived serum antibody standard substance of DT and TT served as the standard substance.The dose-response curves of the tested samples and standard substance were fitted.Then the two quantitative ELISA methods for determining the antibody to DT (Anti-DT) and antibody to TT (Anti-TT) were established with the parallel lines method.Then the methodological verification and application study were conducted.Results The validation results of the two quantitative ELISA measurement methods were in accordance with the regulations.The quantity limit of ELISA method for quantitative detection of Anti-DT demonstrated to be 0.084 mIU/mL,its average recovery rate was 97.6%.The intra-assay coefficient of variation(CV) and inter-assay CV of this Anti-DT assay were ≤ 3.40% and ≤5.05%,respectively.The quantity limit of ELISA method for quantitative detection of Anti-TT demonstrated to be 0.175 mIU/mL,its average recovery rate was 97.5%.The intra-assay CV and inter-assay CV of this Anti-TT assay were ≤ 2.42% and ≤5.58%,respectively.These two methods were applied for the immunogenicity evaluation after infantile basic immunization by diphtheria and tetanus vaccines.Conclusion The two established quantitative ELISA methods demonstrate high accuracy and good reproducibility,which are suitable for the ordinary laboratory to carry out the work and can be used in the serological effect evaluation after diphtheria and tetanus vaccine immunization and epidemiological study of diphtheria and tetanus disease.

Since the 21st century, minimally invasive technique has become a main development direction of surgery, which has been widely applied in all branches of surgery. In the field of kidney transplantation, minimally invasive technique has been mainly applied in the procurement of living donor kidney, kidney transplantation and the management of complications after kidney transplantation. It not only increases the resource of donor kidney, but also reduces the incidence of postoperative complications and enhances the quality of life of the recipients. The application of minimally invasive technique has become one of the research hot spots in the field of kidney transplantation. In this article, research progresses on the application of minimally invasive technique in the procurement of living donor kidney, kidney transplantation and management of complications after kidney transplantation were reviewed, aiming to provide reference for increasing the resource of donor kidney, enhancing the success rate of kidney transplantation and improving clinical prognosis of kidney transplant recipients, thereby promoting the development of minimally invasive technique in surgery.

Norovirus is one of the leading causes of acute non-bacterial gastroenteritis. Emergence of new genotypes due to frequent genetic recombination and antigenic drift increases the prevalence of noro-virus infection worldwide. Norovirus infection has become a global public health concern. This review fo-cused on disease burden, vaccine research, cell culture and animal models regarding norovirus infection.

Objective To evaluate the immune effects of virus-like particles ( VLPs) assembled from the capsid protein VP1 of a recombinant norovirus ( NoV) GⅡ. 17 genotype. Methods The recombi-nant NoV GⅡ. 17 VP1 VLPs were purified, and then tested by SDS-PAGE and Western blot to analyze the purity. The size, morphology and diameter distribution of the recombinant VLPs were detected by transmis-sion electron microscopy ( TEM) and dynamic light scattering ( DLS) analyzer. The recombinant VP1 VLPs adsorbed by aluminium adjuvant were used to immunize BALB/c mice. Serum samples were collected after immunization. Specific antibody level and neutralizing antibody activity were evaluated with enzyme linked immunosorbent assay ( ELISA) and histo-blood group antigen ( HBGA)-VLP blocking test. Cross-reactivity of serum samples with GⅠ. 1 and GⅡ. 4 VP1 VLPs were detected. Moreover, cross-protection against GⅠ. 1 and GⅡ. 4 VP1 VLPs was analyzed. Results The purity of the recombinant NoV GⅡ. 17 VP1 VLP was greater than 90％ and specific bands were detected by Western blot. TEM images and DLS experiments showed that VLPs were 30-50 nm in size with good morphology and uniformity, indicating that the recombi-nant VLPs were similar to the wildtype virus. High titers of specific antibodies were detected in serum sam-ples of the immunized mice. A certain degree of cross-reactions between serum samples and VP1 VLPs of NoV GⅠ. 1 and GⅡ. 4 were observed, but no cross-protection was detected. Conclusion The recombinant GⅡ. 17 VP1 VLPs in combination with aluminum adjuvant can induce higher titers of HBGA blocking anti-bodies in mice, suggesting that it could be used as a candidate target antigen for norovirus vaccine.

Objective:To systematically evaluate the prevalence of norovirus causing sporadic acute gastroenteritis in China.Methods:Relevant articles on acute gastroenteritis caused by norovirus in China published between January 2010 and October 2023 were retrieved from Wanfang, CNKI and PubMed database. The articles met inclusion and exclusion criteria were enrolled in this study. Excel software and SPSS20.0 software were used for statistical analysis. The epidemiological features of sporadic cases of acute gastroenteritis caused by norovirus in China were summarized using descriptive statistical analysis.Results:A total of 500 articles were included in this study, involving 784 486 cases of acute gastroenteritis and 670 292 samples in 32 provinces and regions. Norovirus GⅡ was the predominant genogroup causing acute gastroenteritis in China in recent years, but there were significant differences in the distribution of genotypes and epidemic strains at different times. GⅡ.4 was the predominant genotype in each year, and GⅡ.4/2006b and GⅡ.4 /Sydney_2012 were the main epidemic strains. Norovirus-related diarrhea occurred throughout the year, especially between the months of October and December. The incidence of norovirus infection was high in children under five years old and varied in different regions.Conclusions:Norovirus GⅡ was the predominant genogroup causing norovirus-related sporadic acute gastroenteritis in China, but there was an obvious genetic evolutionary trend in the epidemic strains. Factors such as epidemic strains, season and geographical region should be considered when making strategies for the prevention and control of norovirus-related diarrhea and developing vaccines.

Objective: To detect norovirus (NoV) GⅠ.1- and GⅡ.4-specific IgG, IgA and histo-blood group antigen (HBGA)-blocking antibodies in healthy populations of all age groups in China for better understanding the epidemiological features of norovirus in China from a serological point of view and providing basic data for vaccine development and clinical trial design. Methods: Indirect ELISA and HBGA-blocking assay were used to detect NoV-specific IgG, IgA and HBGA-blocking antibodies in serum samples collected from healthy natural populations (n=839, aged from six months to 88 years old) in Guangzhou, Fuyang and Yantai. The results were statistically analyzed. Results: The total positive rates of NoV GⅠ.1- and GⅡ.4-specific IgG antibodies were 91.9% and 93.0%. The positive rates of GⅠ.1- and GⅡ.4-specific IgA antibodies were 48.6% and 75.6%, and the titers of HBGA-blocking antibodies to GⅠ.1 and GⅡ.4 norovirus were 5.04 (95%CI: 4.63-5.49) and 18.15 (95%CI: 16.11-20.44). The positive rates of IgG and IgA antibodies generally showed an increasing trend with age. The positive rates of GⅠ.1- and GⅡ.4-specific IgG antibodies ranged from 79.2% to 100.0% and 76.7% to 100.0% in different age groups. They were 81.7% and 85.0% in the age group of 0.5-<1 year, 79.2% and 76.7% in the age group of 1-<2 years, and 98.1% and 96.3% in the age group of 12-<18 years, and maintained at 96% and 98% in the older age groups. The positive rates of GⅠ.1-specific IgA antibody ranged from 11.7% to 93.8% in different age groups and rapidly increased with age. It was 11.7% in the age group of 0.5-<1 year, and reached 93.3% in people aged 45-<60 years and 93.8% in people aged ≥60 years. The positive rates of GⅡ.4-specific IgA antibody ranged from 50.8% to 88.8% in different age groups with 50.8% in people aged 0.5-<1 year, and 86.7%-90.7% in people aged 12-<18 years and older. The titer of GⅠ.1 HBGA-blocking antibody generally increased with age. The antibody titer in populations aged 0.5-<12 years old was lower than that in those aged 18 years and above (GMT: 2.98-4.07 vs 8.21-11.62, P<0.001), and the titer in people of 12-<18 years old was lower than that in those of 45 years old and above (GMT: 5.21 vs 11.03-11.62, P<0.05). No obvious change with age was observed in the titer of GⅡ.4 HBGA-blocking antibody excepting the significant difference between populations of 2-<5 and 22-<45 years old (GMT: 26.73 vs 11.87, P<0.01). Conclusions This study revealed the characteristics of serum NoV GⅠ.1- and GⅡ.4-specific IgG, IgA and HBGA blocking antibodies in populations of different age groups in central and eastern China through analyzing their positive rates and titers and provided preliminary seroepidemiological data for the development of NoV vaccines in China.