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The World Health Organization (WHO) has highlighted the importance of an international standard (IS) for SARS-CoV-2 neutralizing antibody titer detection, with the aim of calibrating different diagnostic techniques. In this study, IS was applied to calibrate neutralizing antibody titers (IU/mL) and binding antibody titers (BAU/mL) in response to SARS-CoV-2 vaccines. Serum samples were collected from participants receiving the Moderna (n = 20) and Pfizer (n = 20) vaccines at three time points: pre-vaccination, after one dose, and after two doses. We obtained geometric mean titers of 1404.16 and 928.75 IU/mL for neutralizing antibodies after two doses of the Moderna and Pfizer vaccines, respectively. These values provide an important baseline for vaccine development and the implementation of non-inferiority trials. We also compared three commercially available kits from Roche, Abbott, and MeDiPro for the detection of COVID-19 antibodies based on binding affinity to S1 and/or RBD. Our results demonstrated that antibody titers measured by commercial assays are highly correlated with neutralizing antibody titers calibrated by IS.
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Aim To explore the change of stem cell factor-C-kit (SCF-C-kit) system in irritable bowel syn-drome with diarrhea ( IBS-D) and the correlation be-tween SCF-C-kit system and immune dysfunction . Methods Twelve neonatal rats were divided into nor-mal group and model group with six rats in each group . IBS-D rat model was established through three-factor method ( mother-son separation , acetic acid stimulation and constraint ) . Immunohistochemistry was used to observe in situ protein expressions of SCF and C-kit. qPCR was used for mRNA expressions of SCF and C-kit.Correlation between SCF-C-kit system and spleen coefficients , thymus coefficients , TNF-α, IL-8 , IL-10 was analyzed by statistics .Results Compared with normal group , positive rates of SCF and C-kit protein in model group both decreased , and so did mRNA ex-pression .Expression of SCF was negatively correlative with spleen coefficient , TNF-αexpression and IL-8 ex-pression , while positively correlative with IL-10 expres-sion.Expression of C-kit was negatively correlated with thymus coefficient , spleen coefficient and TNF-α. Conclusion SCF-C-kit system of IBS-D is abnormal, which may be related with immune dysfunction .
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Objective To investigate the existence, intensit y and persisting time of biologic activity of bronchoalveolar lavage fluid (BALF ) collected from dogs with acute severe smoke inhalation injury in early post-i njury stage. Methods BALF was collected 1 h after the est ablishment of acute severe sawdust smoke inhalation injury in 5 dogs, and the fl uid was perfused into the lungs of Wistar rats in the amount of 5 ml/kg (gro up C). Normal saline (group A) and BALF from normal dog (group B) were perfused into the lungs of rats and served as control. The respiratory rate, PaO2, lung water content and the expanding stability of lungs in all rats were determ ined at the time points of 4,12 and 24 h after the purfusion. Results Compared with the rats in group A and B, the rats in group C had higher mortality, wider range in RR, higher lung water content, PaO2 decreased obviou sly and lower lung expanding stability. The rats in control groups showed sl i ght mechanic obstruction in their airways in the course of experiment. Meanwhile ，the rats in group C showed higher oxidative activities and lower total anti-o xidative activities in lung tissues. Conclusion It is certai n that the BALF collected from dogs with acute severe smoke inhalation injury in early post-injury stage could induce obvious injury in lung structure of norma l rats, showing certain mechanic obstruction in small airways. The injuring act ivity of the BALF can be alleviated ultimately 24 h after the perfusion of the B ALF.
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Objective To investigate the existence, intensit y and persisting time of biologic activity of bronchoalveolar lavage fluid (BALF ) collected from dogs with acute severe smoke inhalation injury in early post-i njury stage. Methods BALF was collected 1 h after the est ablishment of acute severe sawdust smoke inhalation injury in 5 dogs, and the fl uid was perfused into the lungs of Wistar rats in the amount of 5 ml/kg (gro up C). Normal saline (group A) and BALF from normal dog (group B) were perfused into the lungs of rats and served as control. The respiratory rate, PaO2, lung water content and the expanding stability of lungs in all rats were determ ined at the time points of 4,12 and 24 h after the purfusion. Results Compared with the rats in group A and B, the rats in group C had higher mortality, wider range in RR, higher lung water content, PaO2 decreased obviou sly and lower lung expanding stability. The rats in control groups showed sl i ght mechanic obstruction in their airways in the course of experiment. Meanwhile ，the rats in group C showed higher oxidative activities and lower total anti-o xidative activities in lung tissues. Conclusion It is certai n that the BALF collected from dogs with acute severe smoke inhalation injury in early post-injury stage could induce obvious injury in lung structure of norma l rats, showing certain mechanic obstruction in small airways. The injuring act ivity of the BALF can be alleviated ultimately 24 h after the perfusion of the B ALF.
