Application of multidirectional stitching technology in a laparoscopic suturing instructional program: a randomized controlled trial.

BACKGROUND: Surgeon suturing technology plays a pivotal role in patient recovery after laparoscopic surgery. Intracorporal suturing and knot tying in minimally invasive surgery are particularly challenging and represent a key skill for advanced procedures. In this study, we compared the application of multidirectional stitching technology with application of the traditional method in a laparoscopic suturing instructional program. METHODS: We selected forty residents within two years of graduation to assess the specialized teaching of laparoscopic suturing with laparoscopic simulators. The forty students were randomly divided into two groups, a control group and an experimental group, with twenty students in each group. The control group was scheduled to learn the traditional suture method, and the experimental group applied multidirectional stitching technology. The grades for suturing time, thread length, accuracy of needle entry, stability of the knot, tissue integrity, and tightness of the tissue before and after the training program were calculated. RESULTS: There was no significant difference between the two groups before the learning intervention. After the program, both groups significantly improved in each subject. There were significant differences between the control group and the experimental group in suture time (P = 0.001), accuracy of needle entry and exit (P = 0.035), and whether the suture tissue had cracks (P = 0.030). However, the two groups showed non-significant differences in thread length (P = 0.093), stablity of the knot (P = 0.241), or tightness of the tissue (P = 0.367). CONCLUSIONS: Multidirectional stitching technology improves the efficiency and effectiveness of traditional laparoscopic suture instructional programs. It might be a practicable, novel training method for acquiring proficiency in manual laparoscopic skills in a training setting.

Three-dimensional poly-(ε-caprolactone) nanofibrous scaffolds directly promote the cardiomyocyte differentiation of murine-induced pluripotent stem cells through Wnt/ß-catenin signaling.

BACKGROUND: Environmental factors are important for stem cell lineage specification, and increasing evidence indicates that the nanoscale geometry/topography of the extracellular matrix (ECM) directs stem cell fate. Recently, many three-dimensional (3D) biomimetic nanofibrous scaffolds resembling many characteristics of the native ECM have been used in stem cell-based myocardial tissue engineering. However, the biophysical role and underlying mechanism of 3D nanofibrous scaffolds in cardiomyocyte differentiation of induced pluripotent stem cells (iPSCs) remain unclear. RESULTS: Here, we fabricated a 3D poly-(ε-caprolactone) (PCL) nanofibrous scaffold using the electrospinning method and verified its nanotopography and porous structure by scanning electron microscopy. We seeded murine iPSCs (miPSCs) directly on the 3D PCL nanofibrous scaffold and initiated non-directed, spontaneous differentiation using the monolayer method. After the 3D PCL nanofibrous scaffold was gelatin coated, it was suitable for monolayer miPSC cultivation and cardiomyocyte differentiation. At day 15 of differentiation, miPSCs differentiated into functional cardiomyocytes on the 3D PCL nanofibrous scaffold as evidenced by positive immunostaining of cardiac-specific proteins including cardiac troponin T (cTnT) and myosin light chain 2a (MLC2a). In addition, flow cytometric analysis of cTnT-positive cells and cardiac-specific gene and protein expression of cTnT and sarcomeric alpha actinin (α-actinin) demonstrated that the cardiomyocyte differentiation of miPSCs was more efficient on the 3D PCL nanofibrous scaffold than on normal tissue culture plates (TCPs). Furthermore, early inhibition of Wnt/ß-catenin signaling by the selective antagonist Dickkopf-1 significantly reduced the activity of Wnt/ß-catenin signaling and decreased the cardiomyocyte differentiation of miPSCs cultured on the 3D PCL nanofibrous scaffold, while the early activation of Wnt/ß-catenin signaling by CHIR99021 further increased the cardiomyocyte differentiation of miPSCs. CONCLUSION: These results indicated that the electrospun 3D PCL nanofibrous scaffolds directly promoted the cardiomyocyte differentiation of miPSCs, which was mediated by the activation of the Wnt/ß-catenin signaling during the early period of differentiation. These findings highlighted the biophysical role of 3D nanofibrous scaffolds during the cardiomyocyte differentiation of miPSCs and revealed its underlying mechanism involving Wnt/ß-catenin signaling, which will be helpful in guiding future stem cell- and scaffold-based myocardium bioengineering.

CircRNA circ-IQGAP1 Knockdown Alleviates Interleukin-1ß-Induced Osteoarthritis Progression via Targeting miR-671-5p/TCF4.

OBJECTIVE: To explore the function of circular RNA IQ motif-containing GTPase-activating protein 1 (circ-IQGAP1) in interleukin (IL)-1ß-induced osteoarthritis (OA) model and to explore whether circ-IQGAP1 can modulate microRNA-671-5p (miR-671-5p) and transcription factor 4 (TCF4) to regulate chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation. METHODS: The cartilage tissues were collected from 32 OA patients or normal subjects. Human chondrocyte CHON-001 cells were challenged via different doses of IL-1ß for 24 hours. CHON-001 cells were transfected with circ-IQGAP1 overexpression vector, TCF4 overexpression vector, small interfering RNA (siRNA) for circ-IQGAP1, miR-671-5p mimic, miR-671-5p inhibitor or corresponding negative controls. Circ-IQGAP1, miR-671-5p and TCF4 abundances in cartilage tissues or CHON-001 cells were examined via quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blot. Cell viability was investigated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). Cell apoptosis was measured by flow cytometry. The inflammatory injury was analyzed by the secretion levels of inflammatory cytokines (IL-6, IL-8 and tumor necrosis factor-α [TNF-α]) by enzyme-linked immunosorbent assay (ELISA). The extracellular matrix degradation was evaluated by expression of aggrecan and matrix metalloproteinase 13 (MMP13) via western blot. The target relationship of miR-671-5p and circ-IQGAP1 or TCF4 was analyzed via dual-luciferase reporter and RNA immunoprecipitation (RIP) analyses. RESULTS: Circ-IQGAP1 abundance was enhanced in the cartilage tissues from OA patients compared with normal subjects (n = 32), and its expression was increased in CHON-001 cells after treatment of IL-1ß in a dose-dependent pattern. MiR-671-5p expression was decreased in the cartilage tissues from OA patients (n = 32) and IL-1ß-challenged CHON-001 cells. MiR-671-5p expression was negatively associated with circ-IQGAP1 level in OA patients. Circ-IQGAP1 silence mitigated IL-1ß-caused chondrocyte viability reduction, apoptosis promotion, secretion of inflammatory cytokine (IL-6, IL-8 and TNF-α), and extracellular matrix degradation (reduction of aggrecan and increase of MMP13). MiR-671-5p was targeted and inhibited via circ-IQGAP1. MiR-671-5p knockdown attenuated the influence of circ-IQGAP1 interference on IL-1ß-caused chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation. TCF4 was targeted via miR-671-5p, and TCF4 expression was increased in the cartilage tissues from OA patients (n = 32) and IL-1ß-challenged CHON-001 cells. TCF4 abundance in OA patients was negatively correlated with miR-671-5p expression. MiR-671-5p overexpression alleviated IL-1ß-mediated chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation via decreasing TCF4 expression. Circ-IQGAP1 silence reduced TCF4 expression via regulating miR-671-5p in IL-1ß-challenged CHON-001 cells. CONCLUSION: Circ-IQGAP1 knockdown attenuated IL-1ß-caused chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation. Circ-IQGAP1 could regulate miR-671-5p/TCF4 axis to modulate IL-1ß-caused chondrocyte damage. Circ-IQGAP1 might act as a new target for the treatment of OA.

A Cell Factory of a Fungicolous Fungus Calcarisporiumarbuscula for Efficient Production of Natural Products.

Fungal natural products are rich sources of clinical drugs. Particularly, the fungicolous fungi have a large number of biosynthetic gene clusters (BGCs) to produce numerous bioactive natural products, but most BGCs are silent in the laboratory. We have shown that a fungicolous fungus Calcarisporiumarbuscula NRRL 3705 predominantly produces the highly reduced polyketide-type mycotoxins aurovertins. Here after evaluation of the aurovertin-null mutant ΔaurA as an efficient host, we further screened two strong promoters aurBp and A07068p based on RNA-Seq, and successfully activated an endogenous gene cluster from C. arbuscula as well as three additional exogenous BGCs from other fungi to produce polyketide-type natural products. Thus, we showed an efficient expression system from the fungicolous fungus C. arbuscula, which will be highly beneficial and complementary to the conventional Aspergillus and Penicillium fungal cell factories, and provides a useful toolkit for genome-wide mining of bioactive natural products from fungicolous fungi.

Role of alpha- and beta-adrenergic receptors in cardiomyocyte differentiation from murine-induced pluripotent stem cells.

OBJECTIVES: Induced pluripotent stem cell (iPSC)-derived cardiomyocytes are a promising source of cells for regenerative heart disease therapies, but progress towards their use has been limited by their low differentiation efficiency and high cellular heterogeneity. Previous studies have demonstrated expression of adrenergic receptors (ARs) in stem cells after differentiation; however, roles of ARs in fate specification of stem cells, particularly in cardiomyocyte differentiation and development, have not been characterized. MATERIALS AND METHODS: Murine-induced pluripotent stem cells (miPSCs) were cultured in hanging drops to form embryoid bodies, cells of which were then differentiated into cardiomyocytes. To determine whether ARs regulated miPSC differentiation into cardiac lineages, effects of the AR agonist, epinephrine (EPI), on miPSC differentiation and underlying signalling mechanisms, were evaluated. RESULTS: Treatment with EPI, robustly enhanced miPSC cardiac differentiation, as indicated by increased expression levels of cardiac-specific markers, GATA4, Nkx2.5 and Tnnt2. Although ß-AR signalling is the foremost signalling pathway in cardiomyocytes, EPI-enhanced cardiac differentiation depended more on α-AR signalling than ß-AR signalling. In addition, selective activation of α1 -AR signalling with specific agonists induced vigorous cardiomyocyte differentiation, whereas selective activation of α2 - or ß-AR signalling induced no or less differentiation, respectively. EPI- and α1 -AR-dependent cardiomyocyte differentiation from miPSCs occurred through specific promotion of CPC proliferation via the MEK-ERK1/2 pathway and regulation of miPS cell-cycle progression. CONCLUSIONS: These results demonstrate that activation of ARs, particularly of α1 -ARs, promoted miPSC differentiation into cardiac lineages via MEK-ERK1/2 signalling.

Expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths.

BACKGROUND: It has been studied that the distribution of bone morphogenetic protein 2 is regular under bone defect situation. OBJECTIVE: To observe the expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths. METHODS: Forty-eight New Zealand rabbits were divided into two groups randomly. 0.5 cm bone defect and 3.0 cm bone defect were made by wire saw at the middle part of radius bone after anaesthesia. RESULTS AND CONCLUSIONS: Western blot results showed that in the 0.5 cm bone defect group, the expression of bone morphogenetic protein 2 of the tissues in the bone defect site was increased gradually at 1, 3, 4 weeks after operation, and the expression in each defect group was increased when compared with that immediately after injury (P<0.05). In the 3.0 cm bone defect group, the expression of bone morphogenetic protein 2 of tissues in bone defect site was increased gradually and reached to its peak at 3 weeks after the operation (P<0.05). The peak value in the 3.0 cm bone defect group was significantly higher than that in 0.5 cm bone defect group (P<0.05). The peak value was maintained in high level. The comparison of bone callus formation showed that the bone callus formation of 3.0 cm bone defect group was less than that of the 0.5 cm bone defect group at 3 and 4 weeks after operation (P<0.05). The results indicate that expression of the bone morphogenetic protein 2 in 3.0 cm bone defect site is increased significantly, but the expression level cannot make the bone defect heal itself.

Test results analysis on wild measles virus neutralizing antibodies in 70 pairs of mother and infant / 上海预防医学

[Objective] To investigate the level of wild -measles neutralization antibody of both mother and infant , and its correlation between the paired mother and infant . [ Methods] The wild-mea-sles neutralization antibody in the serum of the women and their infants were detected directly by a neutral -ization test (NT) methods. [ Results] The positivity rates of neutralization antibody in mothers and their infants were 91.52%and 88.57%respectively, geometric mean title of neutralization antiboby (GMT) being 61.32 and 58.17 respectively.And the titer of neutralization antibody was highly correlated ( r=0.899, P<0.01)between mother and infant in pairs.When the GMT of mother was ≥1∶16,the positivity rate of neutralization antibody in their infants might reach 100.00%. [ Conclusion] It is important to increase the maternal measles antibody level in order to prevent infants from measles .

Heat impact upon the infectivity of hepatitis B virus in serum / 中华预防医学杂志

<p><b>OBJECTIVE</b>This article was to explore the impact of temperature on hepatitis B virus infectivity.</p><p><b>METHODS</b>HBV positive serum with a HBV DNA titer of 1.33 × 10(8) copies/ml was aliquots into 23 Ep tubes with 1.5 ml, 100 µl in one tube.15 tubes were incubated at 37, 56 and 65°C for 0, 30, 60, 120 and 600 minutes, respectively. The other 8 tubes were incubated at 98°C for 0, 5, 10 and 30 minutes, respectively. Post-treated serum at all time points were selected to infect HepG-2 cell. When 18 hours after infection, these cells were extensively washed with phosphate buffered saline. Cells were harvested after the addition of fresh culture medium to culture cells for 48 hours. HBV DNA was detected by FQ-PCR.</p><p><b>RESULTS</b>HBV DNA was detected in cells that were infected by serum at 37°C and 56°C for 30, 60, 120 and 600 minutes, respectively. The titers for the cells incubated at 37°C were (4.85 ± 1.71) × 10(5), (3.85 ± 1.76) × 10(5), (1.67 ± 0.67) × 10(5), (7.86 ± 1.03) × 10(4) copies/ml, and those for the cells incubated at 56°C were (4.01 ± 0.16) × 10(5), (9.77 ± 0.97) × 10(4), (6.36 ± 0.65) × 10(4), (5.05 ± 0.24) × 10(3) copies/ml at different incubation time points. For the cells incubated at 65°C for 60 and 120 minutes, HBV DNAs were (5.15 ± 7.28) × 10(3) and (7.56 ± 10.60) × 10(2) copies/ml, respectively, which were much lower than those in the controls cells ((6.79 ± 1.48) × 10(5) copies/ml). The results of HBV DNA were different (F = 104.4, P < 0.001) in groups treated with different temperature, and results of HBV DNA were also different (F = 144.0, P < 0.001) in groups processed for different period of time. Temperature and processing time had interaction (F = 23.6, P < 0.001). After heating at 98°C for 10 minutes and boiling for 5 minutes, the HBV DNA copy number ((3.02 ± 4.26) × 10(2), (4.31 ± 6.09) × 10(2) copies/ml) in infected cells decreased by about 10 folds than that in the control group ((6.79 ± 1.48) × 10(5) copies/ml). HBV DNAs were not detected in cells that were infected by serum which was heated at 98°C for 30 minutes and boiled for 10 minutes.</p><p><b>CONCLUSION</b>The infectivity of HBV serum in vitro was relatively stable at low temperature, and it would lose its infectivity in short period of time at high temperature.</p>

Study on evolutionary origin of influenza A virus (H1N1) based on HA gene / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the evolutionary rate and divergence time of influenza A virus HA gene isolated recently worldwide pandemic and explore the origin and its transmission.</p><p><b>METHODS</b>A total of 344 H1 sequences available in the GenBank (including 248 isolated from human, 84 from swine, 11 from avian, and 1 from ferret) and 7 isolated in Shanghai were collected. The nucleotide substitution rate and time to most recent common ancestor (tMRCA) was calculated using molecular clock theory and Bayesian Skyline Plot (BSP) based on Markov chain Monte Carlo. Then genetic phylogeny was constructed referring to posterior distribution.</p><p><b>RESULTS</b>It was found that H1 sequences in the US from human, swine and avian were clustered significantly with swine H1 ones from Asia phylogenetically (Cluster US). The second cluster (Cluster Eurasian Human) nearly consisted of human H1 sequences isolated in other regions. The third cluster (Cluster Eurasian Animal) consisted of swine and avian H1 sequences from China and Italy respectively. As for all the H1 sequences, the evolutionary rate was of 2.57 x 10(-3) substitutions/site per year averagely (95% Highest Posterior Density: 1.96 x 10(-3) - 3.03 x 10(-3)/site per year). The estimated dates for tMRCA of human H1 in Europe and swine H1 in the mainland of China were the earliest, with the corresponding rates of 6.46 x 10(-3)/site per year and 0.97 x 10(-3)/site per year respectively. The tMRCAs of human and swine H1 sequences from the US were similar, with the rates of 5.86 x 10(-3)/site per year and 5.02 x 10(-3)/site per year.</p><p><b>CONCLUSION</b>The present flu outbreak was possibly induced by long-term circulation of influenza A virus (H1N1) in human population and swine herds in America. There was no evidence proving that influenza virus in China involved in the present outbreak.</p>

Etiology monitoring of influenza virus and variation in hemagglutinin genes of H13 subtype in Wuxi area / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To monitor the seasonal distribution of influenza types and subtypes in Wuxi area during 2005-2008, and to investigate the variation in hemagglutinin (HA) genes of A/H3N2 strains in 2008.</p><p><b>METHODS</b>Nose-throat swab specimens were collected in Wuxi area from flu-like patients from outpatient departments of hospitals as well as from clustering flu-like outbreak patients from workspace, followed by MDCK cell inoculation. Types and subtypes of positive influenza isolates were identified using standard antiserum. We then sequenced the HA genes for H3 subtype influenza viruses isolated from 2008 specimens to investigate the variation in HA genes.</p><p><b>RESULTS</b>During 2005 and September 2008, 435 strains of influenza viruses were isolated from flu-like patients in Wuxi Area, among which 164 isolates are of A/H1N1 subtype, 80 isolates are of A/H3N2 subtype, and 191 isolates are of B type. These types/subtypes have significant seasonal distributions. Sequences of HA genes for H3 subtype show that the 9 strains isolated in Wuxi area are similar to those of strains isolated in Shanghai within the same period. Many of the sequences belong to the same branch of the phylogenetic tree, and are similar to sequences of vaccine strains in WHO 2008-2009 repositories.</p><p><b>CONCLUSION</b>A/H1N1, A/H3N2 and B still attribute to most of the sporadic and local outbreaks of influenza infection in Wuxi area in recent years. HA genes of A/H3N2 strains isolated in Wuxi area are similar to those of strains isolated in Shanghai in the same period, and also similar to those of vaccine strains recommended by WHO for 2008-2009.</p>

Type and subtype distribution of influenza virus and genetic evolution of hemagglutinin in Shanghai area in duration of 2004 - 2008 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the type and subtype distribution of influenza virus and the genetic evolution of hemagglutinin (HA) in Shanghai area during 2004 to 2008.</p><p><b>METHODS</b>All 962 throat swabs were collected from influenza-like patients in 5 influenza sentry hospitals and influenza outbreaks. Influenza viruses were isolated in MDCK cell lines, and then viral types and subtypes were identified. The HA of influenza A isolates selected by outbreak or sporadic patients in different areas and epidemic seasons were sequenced and analyzed by phylogenetic trees.</p><p><b>RESULTS</b>A/H3N2, accounting for 54.9% (162/295), was the dominate subtype in recent years, but less popular in the end of 2005 to the middle of 2006 with 0% (0/16)and 23.5% (8/34) of positive specimen, respectively. There were more A/H1N1 isolates in 2005 - 2006 with 21.4% (12/56), 43.8% (7/16) and 76.5% (26/34) of positive specimen, respectively, but declined obviously in 2007 - 2008 accounting for only 0% (0/44) and 5.0% (7/139). Influenza B virus was more popular in 2004 to 2005 with 42.9% (24/56) and 56.2% (9/16), respectively, and not isolated from 2006 to 2007, then increased in 2008 accounting for 34.5% (48/139). Phylogenetic tree of HA showed that A/H1N1 isolates in the same year clustered from 2005 to 2008, and most A/H3N2 isolated were homologous in the same year during 2004 - 2008 while some were inserted to the clusters of near years and more distinguished sequences appeared. A/H1N1 and A/H3N2 isolates were all similar to the vaccine strains recommended by WHO.</p><p><b>CONCLUSION</b>The distribution of influenza type and subtype kept on changing each year, but A/H3N2 dominated in most years. A/H1N1 and A/H3N2 in the same year clustered, but some A/H3N2 of near years were and evolved faster with more distinguished strains appeared in same interval. Generally, HA of influenza A isolates in Shanghai during 2004 to 2008 were similar to the WHO reference strains.</p>

Sequence analysis on measles viruses isolated in Shanghai in 2005 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To ascertain the genetic characterization and genotype of measles viruses isolated in Shanghai region, in 2005.</p><p><b>METHODS</b>Measles virus was isolated from throat swab specimens collected from suspected measles cases and 450 bp fragment of C terminus of nucleprotein (N) gene was amplified by RT-PCR. Sequence analysis was conducted to ascertain the genotype and to compare the difference of nucleotide with other measles virus strain published in GenBank.</p><p><b>RESULTS</b>4 measles viruses were isolated from 10 throat swab specimens, and the sequence analysis indicated that they belonged to H1 genotype. The homogeneity of 450 nucleotides in the C terminal of the N gene was at 98%-98.2% as compared to H1 genotype (China93-7). They differed from genotype H2 (China94-1) at 6.4%-6.9% and from genotype A (Edmonston) at 6.7%-6.9%, from measles vaccine (Shanghail91) at 7.6%-8.0%. They differed from the other measles viral strain isolated in China in 1993 - 2005 at 0.2%-3.7%. The variation within 4 isolated measles viruses was at 0.7%-1.3%.</p><p><b>CONCLUSION</b>It was H1 genotype measles viruses,which are the native viruses in China that led to the outbreak of measles in Shanghai, in 2005.</p>

Application of gene sequence cluster in research for H3 antigenic evolution of influenza A virus / 中华流行病学杂志

<p><b>OBJECTIVE</b>Gene sequence data were clustered to explore evolution lineages of H3 antigen of influenza A virus.</p><p><b>METHODS</b>All data of H3 RNA sequence in NCBI Genbank and Influenza sequence database were downloaded and aligned in ClustalX while two step cluster method were applied to explore the data.</p><p><b>RESULTS</b>All sequences were aggregated into ten clusters, while seven of them mainly were human virus. Human virus and avian/other mammal virus were separated into different clusters distinctively, but coexisted into same clusters with swine virus. Time and host distribution were very distinctive in these clusters, but no geographic distribution features were found.</p><p><b>CONCLUSION</b>With the interaction of human immunity system, H3 antigen mutated significantly every 5 - 7 years, and the speed of mutation had accelerated with the application of influenza vaccines in recent years. Mean while, human and swine influenza virus were not separated distinctly between clusters indicating that they had short inheritance distance. Result showed again that swine served as the mixer for antigenic recombination of different influenza virus.</p>

Surveillance of hemagglutinin genetic variation of influenza viruses in Shanghai and Wuxi / 中华传染病杂志

Objectives To explore the type and subtype distribution of influenza viruses in influenza-like patients and the hemagglutinin(HA)genetic variation of influenza A viruses in Shang- hai and Wuxi during the influenza prevalent season from 2004 to 2006.Methods Throat swabs were collected from the influenza-like patients in the sentinel hospitals and during the outbreaks,and then inoculated into MDCK cells to isolate influenza viruses,which were subsequently identified by direct immunofluorescence(DIF)and reverse transcription-polymerase chain reaction(RT-PCR).HA seg- ments of influenza A viruses were sequenced to analyze the genetic variation of HA.Results One hundred and twenty-six strains of influenza viruses,including 53 H3N2,43 H1N1 and 30 influenza B viruses were isolated from August 2004 to September 2006,and 7 outbreaks.All these outbreaks oc- curred in February or March The pathogens were identified as H1N1 in one outbreak,H3N2 in two outbreaks,B in two outbreaks and mix infections in two outbreaks(1 H1N1 and B,1 H3N2 and B, respectively).By sequencing the HA segment,the H3 and H1 segments were all homologous to the isolates from different countries in the same period.Conclusion H3N2 and H1N1 are the major strains prevalent in Shanghai and Wuxi,which reach the peak from January to March No HA and NA recom- binant strains and new HA and NA subtypes are found in these areas.The variations of H1 and H3 are similar to those found in other countries.