Studies have shown that ABO blood group is related to the susceptibility and disease progression of SARS-CoV-2 infection, and most studies indicated that group O individuals were less likely to get infected while group A conferred a higher susceptibility to infection and propensity to severe disease. ABO blood group antigens are oligosaccharides expressed on red cells and other tissues. People with different ABO blood type have different susceptibility to a variety of pathogens, including SARS-CoV-2. There are several hypotheses to explain the differences in SARS-CoV-2 infection between ABO blood group individuals. Firstly, anti-A and/or anti-B antibodies could bind to corresponding antigens on the viral envelope and contribute to viral neutralization, thereby preventing target cell from being infected. The SARS-CoV-2 virus and SARS-CoV spike (S) proteins may be bound by anti-A isoagglutinin, which may block interactions between virus and angiotensin-converting-enzyme-2-receptor, thereby preventing entering into lung epithelial cells. Secondly, the receptor binding domain (RBD) of S protein domain can bind to antigen A expressed in respiratory epithelium and promote its infection to respiratory epithelial cells. In conclusion, most studies indicated that group O may be associated with a lower risk of SARS-CoV-2 infection while group A with a higher risk along with severe disease, and the related mechanism needs to be further studied.

Objective: To study the distribution and pharmacokinetics of cefuroxime in rabbit eyes after intravenous administration. Methods: Thirty-five rabbits were randomly divided into 7 groups by random number table method, with 5 rabbits in each group.The rabbits in blank control group were feed without any treatment, the rest rabbits were injected with 40.63 mg/kg cefuroxime intravenously.The rabbits were sacrificed at 0.5 hour, 1.0 hour, 1.5, 2.0, 2.5 and 3.0 hours after injection, and the eyeballs were immediately dissected.The concentration of drug in different ocular tissues was detected by high performance liquid chromatography, and the pharmacokinetic parameters in eyes were computed by the DAS software.This study was approved by the Experimental Animal Ethics Committee of Shanxi Provincial Eye Hospital (201802b). Results: The peak concentrations (Cmax) of cefuroxime were (11.63±0.20), (1.59±0.05), (1.51±0.08), (0.99±0.07), (1.55±0.08) and (8.57±0.17)μg/ml in aqueous humor, iris-ciliary body, vitreous body, retinal-choroid, cornea and sclera, respectively.The times to peak (Tmax) were 1.5 hours, 1.0, 1.0, 0.5, 1.0 and 0.5 hour in aqueous humor, iris-ciliary body, vitreous body, retinal-choroid, cornea and sclera, respectively.The areas under drug time curve (AUC_0-t) were (26.60±0.62), (6.22±0.84), (5.86±0.16), (3.75±0.45), (5.50±0.15) and (26.48±0.73)(μg·h)/ml in aqueous humor, iris-ciliary body, vitreous body, retinal-choroid, cornea and sclera, respectively.Cefuroxime was not detected in the lens at different time points after injection.The parameters of pharmacokinetics were fitted to two compartment model. Conclusions Cefuroxime shows good penetration in aqueous humor, iris-ciliary body, vitreous body, retinal-choroid, cornea and sclera when administrated by intravenous injection in rabbits and cefuroxime has no distribution in lens.Cefuroxime can reach an effective concentration in ocular tissues 0.5 to 1.5 hours after intravenous injection.

Objective: Hepatitis B surface antigen (HBsAg) loss is seldom achieved with nucleos(t)ide analog (NA) therapy in chronic hepatitis B patients but may be enhanced by switching to finite pegylated-interferon (Peg-IFN) alfa-2a. We assessed HBsAg loss with 48- and 96-week Peg-IFN alfa-2a in chronic hepatitis B patients with partial response to a previous NA. Methods: Hepatitis B e antigen (HBeAg)-positive patients who achieved HBeAg loss and hepatitis B virus DNA < 200 IU/mL with previous adefovir, lamivudine or entecavir treatment were randomized 1:1 to receive Peg-IFN alfa-2a for 48 (n = 153) or 96 weeks (n = 150). The primary endpoint of this study was HBsAg loss at end of treatment. The ClinicalTrials.gov identifier is NCT01464281. Results: At the end of 48 and 96 weeks' treatment, 14.4% (22/153) and 20.7% (31/150) of patients, respectively, who switched from NA to Peg-IFN alfa-2a cleared HBsAg. Rates were similar irrespective of prior NA or baseline HBeAg seroconversion. Among those who cleared HBsAg by the end of 48 and 96 weeks' treatment, 77.8% (14/18) and 71.4% (20/28), respectively, sustained HBsAg loss for a further 48 weeks. Baseline HBsAg < 1 500 IU/mL and week 24 HBsAg < 200 IU/mL were associated with the highest rates of HBsAg loss at the end of both 48- and 96-week treatment (51.4% and 58.7%, respectively). Importantly, extending treatment from 48 to 96 weeks enabled 48.3% (14/29) more patients to achieve HBsAg loss. Conclusion Patients on long-term NA who are unlikely to meet therapeutic goals can achieve high rates of HBsAg loss by switching to Peg-IFN alfa-2a. HBsAg loss rates may be improved for some patients by extending treatment from 48 to 96 weeks, although the differences in our study cohort were not statistically significant. Baseline and on-treatment HBsAg may predict HBsAg loss with Peg-IFN alfa-2a.

Nowadays, nucleos(t)ide analogues (NAs) are important drugs for the treatment of chronic hepatitis B and can suppress the virus through inhibiting the activity of hepatitis B virus (HBV) polymerase. However, rtA181 mutation in HBV can reduce the sensitivity of HBV to various NAs, which brings new challenges to antiviral therapy. This article briefly introduces the research advances in the clinical detection rate of rtA181 mutation and its influence on therapeutic effect and prognosis.

Objective To study the technology and the result of dual plane breast augmentation using nipple margin vertical incision of areola.Methods Totally 60 cases of augmentation mammaplasty were involved in this study.The nipple margin vertical incision of areola was applied obliquely into the breast through the pectoralis major fascia.The rib starting point of pectoralis major were cut off,medial to the side of the sternum.Under the pectoralis major the cavity was peeled according to the preoperative design range.Based on the different situation of the breast types Ⅰ,Ⅱ,Ⅲ,dual plane breast augmentations were stripped respectively.After implanting the breast prosthesis,the upper part of the prosthesis was under the pectoralis major and the lower part was under the mammary gland.Results The 60 patients were all after childbearing,20 of whom underwent type 2 dual plane breast augmentation,4 underwent type 3 double plane and the rest underwent type 1 double plane.After 3 months to 2 years follow-up,all cases got satisfactory results,except 1 case of postoperative hematoma and 1 case appeared capsular contracture.Conclusions The nipple margin vertical incision of areola can complete types Ⅰ,Ⅱ,Ⅲ dual plane breast augmentation operation,at the same time it can correct mild-to-moderate mastoptosis.

Objective To reduce immunogenicity of porcine skin by removingα-Gal epitopes expressed in cell surface and extracellular matrix using recombinant α-galactosidase produced by Bacteroides fragilis.Methods The porcine skin was harvested from healthy 2-month-old pigs without any skin disorders before being sterilized by iodine and 75%alcohol, respectively.Enzymatic removal of α-Gal antigen was followed by washing with PBS.The α-Gal antigen in the prepared porcine skin was measured with immunofluorostaining of cryosections and the residual enzyme was measured with a double-antibody sandwich ELISA method.Enzymatic removal procedures were optimized by detecting residual enzyme and the effi-cacy ofα-Gal removal under different enzymatic and washing conditions.Results Efficient enzymatic and washing methods were established to removeα-Gal antigen.Theα-Gal removal efficacy was above 90% and residual enzyme was undetect-able (αprescribed minimum ofα-galactosidase detection with indirect ELISA was 1 ng/ml) .Conclusion It is feasible to efficiently removeα-Gal antigen under these enzymatic and washing conditions, and a method of producing low-immunoge-nicity pig skin dressing for burn is established.

Objective To observe the dynamic changes of ghrelin of spleen-qi-deficiency rats and the intervention effects ofSijunzi Decoction.Methods Experimental rats were randomly divided into normal control group, model group andSijunzi Decoction group. Except for normal control group, spleen-qi-deficiency model was copied through the two-factor methods of breaking qi by bitter cold and swimming exhausted. Meanwhile,Sijunzi Decoction group was given 20 g/(kg?d)Sijunzi Decoction intervention. The activities of GAS, MTL, SS and VIP at different time points (14, 21, 28 d) in intestine and serum were detected by ELISA and RIA. At the same time the intervention effect of Sijunzi Decoction was studied.Results Compared with normal control group, GAS and MTL in intestine and serum of model rats decreased, while SS and VIP increased (P<0.05,P<0.01). Compared with model group, GAS and MTL in intestine and serum of rats in theSijunzi Decoction group increased, while SS and VIP decreased (P<0.05,P<0.01).Conclusion Ghrelin in intestine and serum of spleen-qi-deficiency rats shows dynamic coincidental changes.Sijunzi Decoction can treat spleen qi deficiency by regulating the activities of rat ghrelin.

Objective To establish a method of quantiying trace α-galactosidase from Bacteroides fragilis in enzymatic conversion of blood group B to O red blood cells ( B-ECO RBCs) .Methods BALB/c mice were immunized with purified recombinant B.fragilisα-galactosidase ( the purity>90%) to prepare monoclonal antibodies.The ascites were prepared using hybridoma cell lines stably secreting antibody and purified by HiTrap rProtein A column.The antibody titer and spe-cificity were detected by ELISA and Western blotting, respectively.Purified monoclonal antibody and rabbit polyclonal an-tibody were applied to detect residual enzyme in B-ECO RBCs and the washing solution was analyzed by indirect ELISA. Results A high titer and purity antibody was obtained.Western blotting showed that the antibody specifically reacted with B.fragilisα-galactosidase.Moreover, indirect ELISA was sensitive enough to detect the minimal amount of residualα-gal-actosidase at the concentration of 1 ng/ml.After four repeat washing cycles with 1∶4 ( v/v) phosphate-buffered saline, the amount of residual enzyme in B-ECO RBCs was less than 10 ng/ml.Conclusion An effective method of detecting the min-imal amount of residual α-galactosidase in blood conversion is established for safety evaluation of universal RBCs prepara-tion by enzymatic treatment.

Objective To investigate the effect of Yiqi Jianpi herb on content of NPY, VIP and expression of Mapk14 mRNA of rats with spleen-qi deficiency. Methods Rats were randomly divided into normal groups, model group (observed on 7 d, 14 d and 21 d), treatment group of Yiqi Jianpi herb, 10 rats in each group. The spleen-qi deficient model rats were made by rhubarb, exhaustive and hungry method, and treatment group was treated with Sijunzi decoction (20 g/kg) for 21 d, then the content of NPY, VIP in serum and small intestine were evaluated with radioimmunoassay, and expression of Mapk14 mRNA in small intestine tissue was evaluated with real time fluorescent quantitative PCR. Results In model group, content of NPY was much lower than that of normal group (P<0.05), content of VIP and relative expression of Mapk14 mRNA in small intestine tissue were much higher than that of normal group (P<0.05), the difference was obvious in 21 d group. Compared with model 21 d group, content of NPY was increased (P<0.05), content of VIP and relative expression of Mapk14 mRNA in small intestine tissue were decreased (P<0.05) in treatment group. Conclusion Yiqi Jianpi herb has functions of adjusting NPY, VIP secretion and inhibiting abnormal expression of Mapk14 mRNA.

Objective To explore the methodology of suturing the upper margin of the orbicularis muscle in pretarsal orbicularis myocutaneous flap to the levator aponeurosis,simulating the mechanism of fibers from the levator aponeurosis to the dermis in natural double-eyelid in blepharoplasty.Methods Pretarsal orbicularis myocutaneous flap was harvested.Dissection between the orbital septum and the levator aponeurosis was performed originating from the upper margin of the tarsi until to the levator muscle.The upper margin of the orbicularis muscle in pretarsal orbicularis myocutaneous flap was sutured to the levator aponeurosis.The lower skin margin to the orbital septum to the upper skin margin was sutured interruptedly.Patients with medial epicanthus were performed epicanthoplasty at the same time.Results 136 eyes in 68 patients were performed with double-eyelid blepharoplasty using this method.62 patients were followed-up for 1 month and 53 patients were followed-up for 3 months.They all reported satisfactory aesthetic results.Conclusions Double-eyelid blepharoplasty using this method accords with the physiological mechanism in natural double-eyelid.Postoperative double-eyelid is natural with little tumefaction.This method can avoid double-eyelid fold retraction and multi-fold occurrence.