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Objective:To investigate the diagnostic value of cardiac magnetic resonance (CMR) contrast medium perfusion and delayed contrast enhancement for early myocardial ischemia.Methods:Ninety-one patients with coronary artery stenosis diagnosed by coronary angiography (CAG) between March 2020 and March 2022 in Yiwu Central Hospital were included in this study. These patients underwent first-pass perfusion cardiac magnetic resonance imaging and delayed enhancement examination. Arrival time ( t0), accumulative signal intensity (ASI), relative peak enhancement rate (SI%), maximum intensity of signal enhancement (SIp), and maximum curve slope (α) were statistically analyzed in the CMR contrast agent normal-dose perfusion and low-dose perfusion segments. The diagnostic value of CMR contrast agent perfusion versus CAG for early myocardial ischemia was determined. The signal intensity was compared between enhanced and non-enhanced areas of CMR contrast agent perfusion. Results:There were significant differences in ASI, SI%, SIp, and Slope (α) between normal perfusion and low perfusion segments ( t = 9.62, 10.65, 8.67, 6.93, all P < 0.05). There was no significant difference in the detection rate of lesioned vessels in early myocardial ischemia between CMR contrast agent perfusion and CAG [50.42% (120/238) vs. 51.68% (123/238), χ2 = 1.32, P = 0.163). There was a significant difference in the detection rate of lesioned vessels in myocardial ischemia between CMR contrast agent perfusion and CAG ( χ2 = 15.31, P < 0.001, r = 0.71). The signal intensity value in the delayed enhancement segment was significantly higher than that in the non-delayed enhancement segment [(598.43 ± 40.19) vs. (298.64 ± 70.58), t =19.85, P = 0.001). Conclusion:CMR contrast agent perfusion can effectively evaluate the severity of early myocardial ischemia and locate the diseased blood vessels. Delayed enhancement can determine the location and area of early myocardial ischemia, and can objectively reflect the severity of myocardial ischemia.
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Objective:To investigate the relationship between prenatal D-dimer level and preeclampsia complicated with postpartum hemorrhage (PPH).Methods:The clinical data of 340 preeclampsia pregnant women in Hechi People′s Hospital from January 2016 to December 2020 were retrospectively analyzed. According to whether PPH occurred, they were divided into preeclampsia complicated with PPH group (PPH group, 57 cases) and uncomplicated PPH group(non PPH group, 283 cases). The general clinical data, blood routine and coagulation function parameters before delivery of the two groups were analyzed, and the differences between the two groups were compared. Logistic regression analysis was used to investigate the relationship between prenatal D-dimer level and preeclampsia complicated with PPH. Meanwhile, the influence of D-dimer level on the occurrence of PPH in preeclampsia patients was quantified. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of D-dimer level on preeclampsia complicated with PPH.Results:Compared with non-PPH group, PPH group had higher white blood cell counting and D-dimer levels ( P<0.05), and lower levels of platelet count and fibrinogen (all P<0.05); there were no significant difference in the levels of hemoglobin and activated partial thrombin time (APTT) between the two groups (all P>0.05). Multivariate logistic regression analysis showed that elevated D-dimer level was an independent risk factor for PPH in preeclampsia patients ( OR=1.150, 95% CI: 1.076-1.230, P<0.001). When D-dimer≥2.16 μg/ml, the risk of PPH in preeclampsia patients increased by 2.804 times ( OR=3.904, 95% CI: 1.705-8.939, P=0.001). In patients who delivered three times or more, D-dimer predicted the occurrence of PPH with an AUC of 0.851, specificity of 60.78%, and sensitivity of 100%. Conclusions:Elevate D-dimer level is an independent risk factor for preeclampsia complicated with PPH. When the D-dimer level increased by 1 unit, the risk of PPH in preeclampsia patients increased by 0.15 times. D-dimer has a high predictive value for the occurrence of PPH in preeclampsia patients who delivered three times or more.
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OBJECTIVE@#To explore the genetic basis for an infant with congenital generalized lipodystrophy.@*METHODS@#Peripheral blood samples of the child and her parents were collected for the extraction of genomic DNA. All exons and flanking sequences of the AGPAT2 gene were subjected to Sanger sequencing.@*RESULTS@#The child was found to harbor compound heterozygous c.792_805delGGAGAACGGGGCCA (p.Gln264Hisfs*208) and c.335C>T (p.P112L) variants in exons 6 and 3 of the AGPAT2 gene, which were respectively inherited from her mother and father. c.792_805delGGAGAACGGGGCCA (p.Gln264Hisfs*208) was previously unreported, while c.335C>T (p.P112L) was known to be pathogenic.@*CONCLUSION@#The compound heterozygous variants of the AGPAT2 gene probably underlie the disease in this child.
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Objective@#To study the diagnostic value of a multi-gene molecular testing in cytologically indeterminate thyroid nodules.@*Methods@#From February 2018 to September 2018, patients with thyroid nodules who underwent fine needle aspiration(FNA) at Peking University Cancer Hospital were enrolled. Three hundred and sixty patients were included, consisting of 86 men and 274 women, with a mean age of 45.8 years (between 13 and 89 years old). Among 391 nodules, 141 were cytologically inderminate and 75 were resected. FNA samples underwent prospective testing using a next-generation sequencing (NGS) assay, which included 16 genes for point mutations and 26 types of gene fusions. The testing results of indeterminate nodules were compared with surgical outcomes, to determine the diagnostic performance. The results were compared with the BRAF V600E single gene mutation analysis by χ2 test.@*Results@#The multi-gene testing showed a sensitivity of 73.2%, specificity of 96.8%, positive predictive value of 96.8%, and negative predictive value of 73.2%. The diagnostic accuracy of multi-gene testing was significantly higher than the BRAF V600E mutation test (83.3% vs 73.6%, χ2=31.588, P<0.01).@*Conclusion@#Multi-gene testing in FNA samples is an effective method to diagnose cytologically indeterminate thyroid nodules, which has a higher accuracy than BRAF V600E mutation detection.
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Objective To investigate the imaging features of MRI in patients with invasive ductal carcinoma of breast cancer .Methods 75 patients with breast ductal carcinoma treated by surgical treatment were selected . According to the age,75 patients were divided into young group (≤40 years) with 22 cases and elderly group ( >40 years) with 53 cases.The morphology,location,size,border and edge of the two groups were analyzed .The time signal intensity curve ( TIC) was analyzed.Results The proportion of patients with non -luminal invasive ductal carcinoma of the young group was 54.55％,which was higher than 30.19％ of the elderly group,the difference was statistically significant(χ2 =3.94,P=0.047).The proportion of breast cancer infiltrating ductal carcinoma in the young group was 63.64％,which was higher than 37.74％in the elderly group,the difference was statistically signifi-cant(χ2 =4.21,P=0.040).The proportion of the infarcted ductal carcinoma in the young group was 59.09％,and that in the elderly group was 62.26％,the difference was not statistically significant(χ2=2.19,P=0.14).The proportion of breast invasive ductal carcinoma in the young group was 63.64％, which in the elderly group was 54.72％, the difference was not statistically significant (χ2 =0.13,P=0.72).Ⅰ,ⅡandⅢtype of breast ductal carcinoma TIC in the young group were 0cases,14cases,8cases,respectively,which in the elderly group were 0cases,36cases,17cases, respectively,there was no statistically significant difference in TIC grade between the two groups (χ2 =2.26,P=0.13 ) .Conclusion Breast infiltrating ductal carcinoma is mostly pulmonary lump type ,tumor border is unclear;MRI dynamic enhancement technique for the detection of breast invasive ductal carcinoma can reduce misdiagnosis .
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Objective To analyze the clinical characteristics and genetic variation of megalencephalic leu-koencephalopathy with subcortical cysts(MCL),then to explore the genetic characteristics so as to help families by pro-viding genetic counseling. Methods The clinical data of the children and their family members were collected,and the peripheral blood DNA of the children and family members were extracted. Then,the MLC1 gene mutation in the children was detected by using the target sequence capture high-throughput sequencing technology and Sanger sequencing tech-nology. Results (1)MCL often presented abnormal head circumference in infants as the first symptom. The main clini-cal manifestations were hypoevolutism in motor development,retrogression of early school age,then the movement disor-der progressed and finally paralyzed;epilepsy was common in early childhood;head magnetic resonance imaging showed white matter in bilateral cerebral hemisphere diffusing abnormal signal with temporal lobe cystic change in the early stage,and then showed brain atrophy. (2)The gene results showed that the 2 girls with MLC had both c. 368C >T (p. Thr123Ile)and c. 353C > T (p. Thr118Met)complex heterozygous variation,which existed in the MLC1 gene. The girls′ father and a sister carried c. 368C > T (p. Thr123Ile),while the mother carried c. 353C > T (p. Thr118Met) heterozygous variation,all of whom were normal phenotypes. Conclusions MCL is one cause of hypoevolutism in motor development in children and abnormal head circumference of infants is usually the first symptom. The MLC1 gene c. 368C> T(p. Thr123Ile)is a pathogenic mutation for MLC,and may be another new pa-thogenic mutation.
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Objective Post-transcription RNA interference (RNAi) is more and more widely applied in multigene therapy.This study aimed to establish an subcutaneous xenotransplanted tumor (SXT) model of human HT-29 colon carcinoma in nude mice and investigate the effects of the survivin shRNA-APC double gene co-expression lentiviral vector on the growth of SXT.Methods Thirty-five nude mice were equally divided into five groups, double-gene survivin shRNA, survivin shRNA, APC, empty vector, and blank, and injected into the left anterior axillary with respective stably transfected cell lines and human HT-29 colon carcinoma cells, all at 2×106/mL, to establish an SXT model of human HT-29 colon carcinoma.The inhibition rate of tumor growth was calculated by measuring the size and weight of the SXT, the expressions of survivin mRNA and protein in the tumor tissue detected by real time PCR and immunohistochemistry respectively, and the apoptosis of the HT-29 colon carcinoma cells determined by TUNEL.Results The mean size and weight of the SXT were significantly reduced in the double-gene survivin shRNA-APC, survivin shRNA, and APC groups as compared with the blank and empty vector groups (P<0.05), though increased in the survivin shRNA and APC groups in comparison with the double-gene group (P<0.05).The expressions of survivin mRNA and protein in the tumor tissue were remarkably lower in the double-gene survivin shRNA-APC, survivin shRNA, and APC groups than in the blank and empty vector groups (P<0.05), even lower in the double-gene group than in the survivin shRNA, and APC groups (P<0.05).The apoptosis rate of the HT-29 colon carcinoma cells was markedly up-regulated in the double-gene survivin shRNA-APC ([56.72±3.17]%), survivin shRNA ([33.64±2.03]%), and APC groups ([31.19±1.79]%) as compared with the blank ([9.89±0.31]%) and empty vector groups ([10.06±0.43]%) (P<0.05), even more significantly in the double-gene than in the survivin shRNA and APC groups (P<0.05).Conclusion The survivin shRNA-APC double gene co-expression lentiviral vector can reduce the expression level the survivin gene, promote the apoptosis of colon carcinoma cells, and suppress the growth of the subcutaneous xenotransplanted tumor.
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Objective To investigate the correlation between quantitative detection of human telomerase reverse transcriptase (hTERT) mRNA in peripheral blood and metachronous liver metastasis and prognosis of colorectal cancer (CRC).Methods The quantitative expression of hTERT mRNA in pre-and post-operative peripheral blood were detected with real-time fluorescence quantitative real-time polymerase chain reaction (RT-PCR) in 168 patients with CRC and normal controls.The postoperative 3 years,prognosis of the CRC patients were followed-up.The relationship between peripheral blood hTERT mRNA expression levels and the metachronous liver metastasis and prognosis of CRC were analyzed.Results The hTERT mRNA expressions in preoperative,6 month postoperative peripheral blood in postoperative liver metastases group were significantly higher than those in the postoperative non-metachronous liver metastases group in the same term [(8.35 ± 5.86) (2-△ △Ct) vs (4.42 ± 2.88) (2-△ △Ct),(1.87 ± 1.85) (2-△ △Ct) vs (1.03 ± 0.92) (2-△△Ct),P ＜ 0.01].The hTERT mRNA expressions in preoperative peripheral blood of CRC group were positively related to the differentiated degree of tumor,tumor size,lymph node metastasis(P ＜ 0.05 or P ＜ 0.01),and were negatively related to the postoperative survival(P ＜ 0.01).Univariate analysis revealed that hTERT mRNA expressions in preoperative and 6 months postoperative peripheral blood were all correlated with postoperative liver metastases from CRC.Multivariate Cox analysis showed that they were independent risk factors for postoperative CRC liver metastases(EXP =4.282,9.171).The 3 year survival rate of the postoperative CRC liver metastases group was significantly lower than that of the postoperative non-CRC liver metastases group.Conclusions hTERT mRNA expressions in preoperative peripheral blood are related to the important pathologic feature,postoperative liver metastasis and prognosis of CRC.hTERT mRNA expressions in preoperative and 6 months postoperative peripheral blood might be a predictive biomarker for CRC metachronous liver metastases.The elevation of hTERT mRNA expression levels in postoperative peripheral blood were related to postoperative CRC liver metastasis.
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Objective Studies show that the abnormal ex-pressions of APC and survivin play important roles in the development and progression of colon cancer .Survivin shRNA and APC double gene co-expression lentiviral vector was constructed to observe whether it could be successfully expressed in HT-29 colon cancer cells and whether it could impact on colon cancer cell apoptosis . Methods We selected the best shRNA interference fragment from the construc-tion of three pairs of complementary shRNA fragments and connected it with the effective fragment of APC ( aa1020-1698 ) to construct a double gene co-expression lentiviral vector .HT-29 cells were divid-ed into experimental group , empty loading group and blank group .HT-29 cells were observed by fluorescence microscopy after infec-tion.Survivin and APC expression levels were observed by real time PCR and western blot .Apoptosis was detected by caspase-3 activi-ty assay. Results ①We successfully constructed three pairs of shRNA sequences and proved that they had no human gene homolo -gous to the rest.Real time PCR analysis showed that the best sequence was shRNA 3.②After the sequence alignment of constructed shRNA vectors, three pairs of shRNA sequences were completely the same with the first designed sequence .Green fluorescence was observed in HT-29 cells by fluorescence microscope .The survivin content in experiment group (31.71 ±1.49) was significantly de-creased compared with empty loading group (100 ±0) and blank group(95.12 ±2.15)(P<0.05).The expression level of APC mR-NA was significantly increased compared with empty loading group (0 ±0) and blank group(0.51 ±0.15)(P<0.05).③The relative ratio of apoptosis in experiment group (0.573 ±0.050) was significantly increased compared with empty loading group (0.390 ± 0.040) and blank group(0.407 ±0.030)(P<0.05). Conclusion We have successfully constructed survivin-shRNA-APC double gene co-expression lentiviral vector which can be successfully expressed in HT-29 colon cancer cells , providing references for subse-quent gene therapy by the use of the carrier .
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Objective To investigate the relationship between the changes of expression of T lymphoma invasion and metastasis inducing factor 1 (Tiam1) mRNA and lymph node micrometastasis and prognosis in patients with node-negative colorectal cancer(CRC).Methods From June 2008 to August 2010,a total of 63 patients with lymph node-negative CRC,20 patients with lymph node-positive CRC and 25 patients with colorectal benign lesions were enrolled.The relative quantity expression (RQ) of Tiam1 mRNA in CRC cancer tissues and colorectal benign lesions were detected by real-time quantitative polymerase chain reaction (PCR).The lymph node micrometastasis was determined by cytokeratin 20 detection in lymph nodes tissues.The five-year postoperative prognosis was evaluated by followed-up in the patients with lymph node-negative CRC.The correlation between the expression of Tiam1 mRNA and lymph node micrometastasis and prognosis was analyzed.The t-test,univariate analysis,multivariate analysis and Log-rank test were performed for statistical analysis.Results Lymphnode micrometastasis occurred in 33 from 63 patients with lymph node-negative CRC.The RQ of Tiam1 mRNA in the patients with lymph node-positive CRC was 9.84±-2.36,which was higher than that of patients with lymph node-negative CRC (5.15±3.58),and the difference was statistically significant (t=5.479,P＜0.01).The RQ of Tiam1 mRNA of these two groups were both higher than that of colorectal benign lesion (0.30± 0.21),and the difference was statistically significant(t=20.169,6.745;both P＜0.01).The RQ of Tiam1 mRNA of positive lymph node micrometastasis group was 6.30±1.95,which was higher than that of negative lymph node micrometastasis group (3.88 ± 1.63),and the difference was statistically significant (t=5.330,P＜0.01).In the patients with lymph node-negative CRC,the lower degree of tumor difference,the deeper invasion,the shorter survival time after surgery and postoperative recurrence and metastasis were related with the higher RQ of Tiam1 mRNA in tumor tissues (t=2.536,3.112,3.213,2.676;all P＜0.05).Univariate analysis revealed that the expression of Tiam1 mRNA in cancer tissues was correlated with lymph node micrometastases(x2=11.878,P =0.001).Multivariate analysis showed that it was an independent risk factors of lymph node micrometastases in CRC (relative risk:9.782).The five-year postoperative cumulative survival rate of high Tiaml mRNA expression group was 75.8 ％,which was lower than that of low expression group (97.1 ％),and the difference was statistically significant (x2 =4.575,P＜0.05).Conclusions Tiam1 may participate in the regulation of lymph node metastasis in CRC.Elevated expression of Tiam1 promotes lymph node metastasis and is closely relatived with poor prognosis of node-negative CRC,and which can be considered as an indicator of prognosis.
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Objective To investigate the relationship between quantitative detection of T lymphoma invasion and metastasis inducing factor (Tiaml) mRNA and invasion,metastasis and prognosis of patients with colorectal cancer.Methods The quantitative expression of Tiam1 mRNA in cancer tissues in colorectal cancers (n =97),in tissues of colorectal adenomatous polyposis (n =49) and normal control (n =30) were detected with real-time fluorescence quantitative-polymerase chain reaction (PCR).The relationship between the quantitative expression of Tiam1 mRNA in colorectal cancer tissues and the invasion,metastasis and the prognosis were analyzed.Results The levels of Tiam1 mRNA expression in the colorectal cancer group,were significantly higher than those in colorectal adenomatous polyposis group and normal controlgroup [(14.45±4.87)2-△△△Ct vs (3.77 ±3.15)2-△△Ct,(1.06 ±0.65)2-△△Ct,P ＜0.01].The levels of Tiam1 mRNA expression in the adenomatous polyposis with high grade intraepithelial neoplasia were signifiCantly higher than those in the adenomatous polyposis with low grade intraepithelial neoplasia [(5.26 ±2.45)2-△△Ct vs (3.78 ±2.19)2-△△Ct,P ＜0.01],which were both significantly higher than those in the adenomatous polyposis with no intraepithelial neoplasia [(2.13 ± 1.64)2-△△Ct,P ＜0.05 or P ＜ 0.01].The levels of Tiam1 mRNA expression in colorectal cancer group were positively related to the differentiated degree of tumor,depth of invasion,lymph node metastasis,tumor node metastasis (TNM) stages and the postoperative recurrence (P ＜ 0.01),and were negatively related to the postoperative survival time (P ＜0.01).Multivariate Cox regression analysis revealed that levels of Tiam1 mRNA expression in cancer tissues were independent prognostic factor for colorectal cancer (Exp =4.043).Conclusions The high Tiam1 mRNA expression levels in cancer tissues are closely related to invasion,metastasis and poor prognosis of colorectal cancer,and may be a prognostic indicator of colorectal cancer.The increase expression of Tiam1 mRNA in colorectal adenomatous polyposis may be related to colorectal tumorigenesis.
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OBJECTIVE@#To investigate the clinical features and therapeutic effects of sudden deafness after radiotherapy combined with chemotherapy in nasopharyngeal carcinoma patients.@*METHOD@#Clinical data of 42 nasopharyngeal carcinoma patients suffered from sudden deafness after radiotherapy combined with chemotherapy were analyzed retrospectively. Among the 42 patients, 2 showed moderate deafness, 4 presented excessive deafness, 30 suffered from severe deafness, and 6 exhibited profound deafness. The audiogram pattern of 33 patients met with the type of high tone frequencies hearing loss, and that of the rest 9 cases showed hearing loss at all frequencies. All patients received medical therapy combined with hyperbaric oxygen therapy.@*RESULT@#Of all the cases with hearing loss, 2 were cured, 2 showed excellent recovery, 9 came out partial recovery, and 29 showed no response to the treatment. The total effective rate was 30.95%. For the accompanied symptoms, none of the 30 cases of tinnitus were relieved, 3 out of 10 cases of aural fullness were cured, and the 5 cases of dizziness or vertigo were all improved.@*CONCLUSION@#The sudden deafness after radiotherapy combined with chemotherapy in patients with nasopharyngeal carcinoma is closely related to radiotherapy. The hearing loss is serious, and the therapeutic effects are not satisfactory.
Subject(s)
Humans , Antineoplastic Agents , Carcinoma , Dizziness , Therapeutics , Hearing Loss, High-Frequency , Therapeutics , Hearing Loss, Sudden , Therapeutics , Hearing Tests , Hyperbaric Oxygenation , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms , Drug Therapy , Radiotherapy , Radiotherapy , Retrospective Studies , Tinnitus , Therapeutics , Vertigo , TherapeuticsABSTRACT
Objective To study the expression of RhoA and C-myc in gastric carcinoma , and to discuss the action in infiltration and metastasis of gastric carcinoma as well as their dependability. Methods RhoA protein expression and C-myc protein expression were detected by immunohistochemical method in 46 cases of gastric carcinoma and 20 cases of normal tissues..RhoA protein expression was compared with clinical pathologic parameters as related to C-myc. Results The positive rate of RhoA,C-myc were significantly higher in gastric carcinoma than in normal tissue (P < 0.05). The expression of RhoA and C-myc were associated with the loss of tumor differentiation, lymph node metastasis and deep invasion (P<0.05). There was a significant correlation between RhoA and C-myc (r=0.62, P<0.05). Conclusions The data suggests that the expression level of RhoA protein was closely related to biological behavior of gastric carcinoma. RhoA and C-myc were possibly both correlated with the infiltration and metastasis of gastric carcinoma.
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BACKGROUND:The methods to remove the smear layer mainly include mechanical, Carisolv chemomechanical, laser, ozone methods and so on. But studies after caries removal are limited. At present, there is no research for the observation of the smear layer after caries removal using Er:YAG laser, Carisolv chemomechanical and traditional dental turbine. OBJECTIVE:To observe the morphologic changes of the dentin smear layer after treated with the three methods of Er:YAG laser, Carisolv chemomechanical and traditional high speed dental turbine under a scanning electron microscope. METHODS:Thirty newly removed premolars or molars with moderate caries were divided into three groups, 10 teeth in each group. The bottom surface of the tooth cavity was observed with the naked eyes after caries removal with Er:YAG laser, Carisolv chemomechanical and traditional dental turbine, respectively. Then, the surface was observed using the scanning electron microscope (magnification ×1 000 and ×2 000). RESULTS AND CONCLUSION:The texture of the tooth cavity was hard in the three groups. After caries removal, the dentin surface of Er:YAG laser group was rough and uneven, and showed a peak-like shape;The dentin surface of Carisolv chemomechanical group was dark and the bottom was flat;The dentin surface of traditional dental turbine group was smooth and bright, and there was an obvious cutting trace. It was found that the surface of Er:YAG laser group did not have the smear layer, and the dentinal tubule was clearly visible. The most dentinal tubules were visible in the Carisolv chemomechanical group, and the surface was covered with a less smear layer. The surface of the traditional dental turbine group was covered with a thick smear layer, and the dentinal tubule was unseen. The differences in dentin smear layer cleanliness were significant between the three groups. These result indicate that Er:YAG laser can effectively remove the smear layer, which is better than Carisolv chemomechanical method and traditional dental turbine. Traditional dental turbine group is the worst among the three methods.
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To investigate the relationship of the variation of virulence and the external capsid proteins of the pandemic duck hepatitis A virus type 1(DHAV-1) isolates,the virulence,cross neutralization assays and the complete sequence of the virion protein 1(VP1) gene of nine virulent DHAV-1 strains,which were isolated from infected ducklings with clinical symptoms in Shandong province of China in 2007-2008,were tested.The fifth generation duck embryo allantoic liquids of the 9 isolates were tested on 12-day-old duck embryos and on 7-day-old ducklings for the median embryonal lethal doses(ELD50s) and the median lethal doses(LD50s),respectively.The results showed that the ELD5s of embryonic duck eggs of the 9 DHAV-1 isolates were between 1.9 × 106/mL to 1.44 × 107/mL,while the LD50s were 2.39 × 105/mL to 6.15 × 106/mL.Cross-neutralization tests revealed that the 9 DHAV-1 isolates were completely neutralized by the standard serum and the hyperimmune sera against the 9 DHAV-1 isolates,respectively.Compared with other virulent,moderate virulent,attenuated vaccine and mild strains,the VP1 genes of the 9 strains shared 89.8％-99.7％ similarity at the nucleotide level and 92.4％-99.6％ at amino acid level with other DHAV-1 strains.There were three hypervariable regions at the C-terminus(as 158-160,180-193 and 205-219) and other variable points in VPI protein,but which didn't cause virulence of DHAV-1 change.