Objective:To research on the immune recognition mechanism of synthetic pyrethroids and generic specific antibody.Methods:We studied on quantitative structure-activity relationship ( QSAR ) of synthetic pyrethroids and their analogs as well as antibody activity ( IC50:fifty percent inhibition concentration ) using stepwise multiple linear regression method.Based on calculating structure descriptors of synthetic pyrethroids and their analogs , two-demensional QSAR ( 2D-QSAR ) model was established.The main factors affecting antibody activity were screened using 2D-QSAR,and predictive ability of QSAR models were evaluated by the method of leave-one-out( LOO) cross-validation.Meanwhile, the structure parameters of synthetic pyrethroid fragments were calculated and then analyzed using partial least squares ( PLS) assay.And then hologram QSAR ( H-QSAR) model was constructed on molecular substructure and antibody activity.The fragments contribution to antibody activity were illustrated by encoding different colors.Results:Decision coefficent (R2) of 2D-QSAR model and HQSAR model were 0.920 and 0.917 individually,cross-validation coefficient ( Q2 ) of two QSAR models were 0.875 and 0.660 respectively ,which showed two models had good predictive abil-ity.The result from 2D-QSAR model was also obtained that smaller was hydrophobicity of pyrethroids , easier was recognized by antibody.In addition,the optimum HQSAR model was constructed after we tried many combinations of these parameters .The fragment size in optimum HQSAR model was between 4 to 10,a hologram length was 61,optimum principle component was 4,and the fragment type of B/C/Ch was selected.However ,the fingerprint encoded results of synthetic pyrethroids weren′t consistent completely with exper-imental IC50 values.Conclusion:Hydrophobicity of synthetic pyrethroids is the largest correlation factors in antibody recognization .

Objective:To observe the abnormal clinical manifestations of retinal blood vessels and the characteristic image characteristics of optical coherence tomography (OCT) in young myopia.Methods:A case observation study. From July to December 2020, 523 young patients with different myopia refractive powers who were treated in Department of Ophthalmology of The Second Hospital of Hebei Medical University were included in the study. Among them, 277 were males and 246 were females; the median age was 19.0 (5.0) years. All the affected eyes underwent best corrected visual acuity (BCVA), frequency domain OCT (SD-OCT) examination and axial length (AL) measurement. The BCVA examination was performed using the Snellen eye chart. The median myopia refractive power of the affected eye was 5.00 (3.25) D. Among them, low myopia, moderate myopia, and high myopia were 227, 405, and 414 eyes, respectively. The average AL of the affected eye was 25.6±2.8 mm. The frequency domain OCT instrument was used to scan the temporal side of the retina, the upper and lower nasal vascular arches and the macular fovea radially. The images of retinal vascular cysts, microfolds, and lamellar hole were acquired and stored. The prevalence, composition ratio, distribution rule and OCT imaging characteristics of retinal paravascular abnormalities were observed and analyzed. The distribution of paravascular abnormalities in the retina was compared by the χ2 test; the age, refractive power, and AL of different paravascular abnormalities were compared by the K-W rank sum test. Results:Of the 1046 different diopters of myopic eyes, there were 227 eyes in mild myopia, 405 eyes in moderate myopia and 414 eyes in high myopia. Retinal paravascular abnormalities were detected by SD-OCT in 40 eyes (3.8%,40/1046). The prevalence of retinal paravascular abnormalities in moderate myopia was 0.7% (3/405) and high myopia was 8.9% (37/414). No retinal paravascular abnormalities were observed in mild myopia.Retinal paravascular cysts in 40 eyes (3.8%, 40/1046), retinal paravascular microfolds in 28 eyes (2.7%, 28/1046) and retinal paravascular lamellar holes in 13 eyes (1.2%, 13/1046). Of 40 eyes with retinal paravascular abnormalities, retinal paravascular cysts in all 40 eyes (100.0%, 40/40), retinal paravascular microfolds in 28 eyes (70.0%, 28/40) and retinal paravascular lamellar holes in 13 eyes (32.5%, 13/40). Twelve eyes with simple cyst cavity (30.0%, 12/40); 15 eyes were with cyst cavity with micro-wrinkles (37.5%, 15/40); 13 eyes were with cyst cavity, micro-wrinkles and lamellar holes (32.5%, 13/40). The temporal vascular arch retinal paravascular cysts ( χ2=25.664), microfolds ( χ2=14.973), and lamellar holes ( χ2=13.499) were significantly more than those on the nasal side, and the difference was statistically significant ( P <0.001). Conclusions:The total prevalence of retinal paravascular abnormalities in young myopia is 3.8%; it can occur in both moderate and high myopia. The paravascular cyst may be the earliest pathology of paravascular abnormalities in the retina. The three paravascular abnormalities are mostly distributed along the temporal arch of the retina.

Objective To investigate the diagnostic value of endoscopic ultrasound-guided fine needle aspiration ( EUS-FNA) on malignant lesions in gastrointestinal adjacent tissue, and further to analyze the risk factors influencing positive rate of EUS-FNA. Methods The clinical data of 171 patients undergoing EUS-FNA from January 2009 to May 2016 were collected. The lesion location, size and characteristics, the number of needle passes, puncture suction negative pressure, size of puncture needle, and years of operator experience in EUS were retrospectively analyzed. Results The overall sensitivity, specificity, and accuracy of EUS-FNA in the diagnosis of malignant lesions were 78. 3％ ( 83/106) , 100. 0％ ( 65/65) , and 86. 5％( 148/171) , respectively. The univariable logistic regression analysis demonstrated that the risk factors of EUS-FNA were lesion location, lesion characteristics, and lesion size. In multivariate analysis, larger lesion size ( OR=1. 029, 95％CI: 1. 011-1. 047, P=0. 001) and lesion characteristics of solid ( OR=5. 098, 95％CI:1. 324-19. 633, P=0. 018) were independent factors affecting the positive rate of EUS-FNA. Among 171 cases performed by EUS-FNA, the incidence of postoperative complications was 1. 75％ ( 3/171 ) included 2 cases of fever and 1 case of acute pancreatitis, which were improved after conservative treatment. Conclusion EUS-FNA is a safe and effective method of cytological and histological diagnosis with high accuracy and sensitivity, importantly in distinguish malignancy from benign lesion in gastrointestinal adjacenttissue. Positive rate of diagnosis on malignant lesions by EUS-FNA is positively correlated with lesion size, and EUS-FNA positive rate of solid malignant lesions is significantly higher than that of cystic lesions.

OBJECTIVETo identify the predictive factors for differentiating pancreatic ductal adenocarcinoma (PDAC) from other neoplastic solid pancreatic lesions and assess the accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis of PDAC.

METHODSWe retrospectively analyzed the clinical data of patients referred for EUS-FNA evaluation of pancreatic lesions in the Digestive Endoscopic Center of Nanfang Hospital between January, 2009 and May, 2016. The cases with unknown diagnosis, missing data, repeated punctures, cystic lesions and benign lesions were excluded from the analysis. The positivity rates of EUS-FNA were compared between patients with PDAC and those with non-PDAC lesions, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS-FNA were assessed in the diagnosis of PDAC. Univariate and multivariate logistic regression analyses were used to identify the factors for differentiating PDAC from non-PDAC lesions based on the demographic characteristics, clinical presentations, laboratory data, and endoscopic ultrasonography imaging features of the patients.

RESULTSAmong the 75 patients with solid neoplastic pancreatic lesions, 54 (72.0%) were found to have PDAC and 21 (28.0%) had non-PDAC lesions. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EUS-FNA for the diagnosis of PDAC were 77.8%, 100.0%, 100.0%, 63.6% and 84.0%, respectively. No significant difference was found in the positivity rate of EUS-FNA between patients with PDAC and those with non-PDAC lesions (77.8% 76.2%, > 0.05). Multivariate regression analysis identified abdominal pain (=5.163, 95%: 1.093-24.389, =0.038), lesion size (=0.926, 95%: 0.877-0.978, =0.006), characteristics of the solid lesions (=7.105, 95%: 1.440-35.043, =0.016), and evidence of metastases (=6.165, 95%: 1.332-28.533, =0.020) as the independent factors for predicting PDAC.

CONCLUSIONSThe pretest characteristics including abdominal pain, evidence of metastases, and lesion size and lesion characteristics defined by endoscopic ultrasonography findings can reliably predict a diagnosis of PDAC. EUS-FNA has a high sensitivity and a high specificity for the diagnosis of PDAC.