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ObjectiveTo explore the intervention mechanism of Xiangsha Liujunzi Tang in rats with functional dyspepsia （FD） based on the Ras homolog gene family member A （RhoA）/Rho-associated coiled-coil containing protein kinase 2 （ROCK2）/Myosin phosphatase target Subunit 1 （MYPT1） pathway. MethodSixty male SD suckling rats in SPF grades were randomly divided into blank group （n=10） and model group （n=50）. The comprehensive modeling method （gavage administration of iodoacetamide+exhaustion of swimming+disturbance of hunger and satiety） was used to replicate the rat model of FD. After successful replication of the model， the rats in the model group were randomly divided into model group， mosapride group， and high， middle， and low-dose Xiangsha Liujunzi Tang groups， with 10 rats in each group. Rats in the blank group and model group were given 10 mL kg-1·d-1 normal saline， those in the mosapride group were given 1.35 mg·kg-1·d-1 mosapride， and those in the high， middle， and low-dose Xiangsha Liujunzi Tang groups were given 12， 6， and 3 g·kg-1·d-1 Xiangsha Liujunzi Tang， respectively. The intervention lasted 14 days. The general living conditions of rats were observed before and after modeling and administration， and the 3-hour food intake and body mass of rats were measured. After intervention， the intestinal propulsion rate of rats was measured， and the pathological changes in the gastric tissue were observed by hematoxylin-eosin （HE） staining. The content of choline acetyl transferase （ChAT） and vasoactive intestinal peptide （VIP） in the medulla oblongata and gastric tissue homogenate was determined by enzyme-linked immunosorbent assay （ELISA）， the distribution of adenosine triphosphate （ATP） enzyme in gastric antrum smooth muscle was observed by frozen section staining， and the protein expression levels of RhoA， ROCK2， and phosphorylated-myosin phosphatase target subunit 1 （p-MYPT1） in the gastric tissue were detected by Western blot. ResultCompared with the blank group， the model group had withered hair， lazy movement， slow action， poor general living condition， lower 3-hour food intake， body mass， and lower intestinal propulsion rate （P<0.05）， whereas no obvious abnormality in gastric histopathology. In the model group， the content of ChAT in the medulla oblongata and gastric tissue decreased， the content of VIP in gastric tissue increased， the distribution of ATP enzyme in gastric antrum smooth muscle decreased significantly， and the protein expression levels of RhoA， ROCK2， and p-MYPT1 in the gastric tissue decreased significantly （P<0.05）. As compared with the model group， the general living condition of rats in each intervention group was significantly improved， and the 3-hour food intake， body mass， and intestinal propulsion rate were significantly increased （P<0.05）. There was no significant difference in gastric pathology in the intervention groups. The content of ChAT in the medulla oblongata and gastric tissue increased significantly， the content of VIP in the gastric tissue decreased， the distribution of ATP enzyme in gastric antrum smooth muscle increased significantly， and the protein expression levels of RhoA， ROCK2， and p-MYPT1 in the gastric tissue increased significantly （P<0.05）. The intervention effect of Xiangsha Liujunzi Tang group on the above indexes was dose-dependent. ConclusionXiangsha Liujunzi Tang can effectively improve the general living condition and gastric motility of rats with FD， and its specific mechanism may be related to the activation of the RhoA/ROCK2/MYPT1 pathway in the gastric tissue to regulate smooth muscle relaxation and contraction and promote gastric motility.
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A global pandemic of Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome CoV-2 (SARS-CoV-2) is ongoing spread. It remains unclear whether the convalescing patients have a risk of reinfection. Rhesus macaques were rechallenged with SARS-CoV-2 during an early recovery phase from initial infection characterized by weight loss, interstitial pneumonia and systemic viral dissemination mainly in respiratory and gastrointestinal tracts. The monkeys rechallenged with the identical SARS-CoV-2 strain have failed to produce detectable viral dissemination, clinical manifestations and histopathological changes. A notably enhanced neutralizing antibody response might contribute the protection of rhesus macaques from the reinfection by SARS-CoV-2. Our results indicated that primary SARS-CoV-2 infection protects from subsequent reinfection. One Sentence SummaryNeutralizing antibodies against SARS-CoV-2 might protect rhesus macaques which have undergone an initial infection from reinfection during early recovery days.
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Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the Corona Virus Disease 2019 (COVID-19) cases in China has become a public health emergency of international concern (PHEIC). Based on angiotensin converting enzyme 2 (ACE2) as cell entry receptor of SARS-CoV, we used the hACE2 transgenic mice infected with SARS-CoV-2 to study the pathogenicity of the virus. Weight loss and virus replication in lung were observed in hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes and monocytes in alveolar interstitium, and accumulation of macrophages in alveolar cavities. Viral antigens were observed in the bronchial epithelial cells, alveolar macrophages and alveolar epithelia. The phenomenon was not found in wild type mice with SARS-CoV-2 infection. The pathogenicity of SARS-CoV-2 in hACE2 mice was clarified and the Kochs postulates were fulfilled as well, and the mouse model may facilitate the development of therapeutics and vaccines against SARS-CoV-2.
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Objective To compare the efficiency of domestic MALDI-TOF MS systems Autof MS, Korea Asta MicroIDsys and Bruker Biotyper for common microorganisms identification. Methods This is a methodological comparison study. A total of 169 strains were isolated either from food in our laboratory since 2011 to 2018 or clinical samples in Chinese PLA General Hospital since 2016 to 2018. A total of 39 genus, 95 species were identified through Vitek2 Compact combined with 16S rDNA or ITS sequencing. Among them, a total of 93 Gram-negative bacteria strains, 65 Gram-positive bacteria strains, and 11 yeast strains were identified by three MALDI-TOF MS systems parallelly, while using extended direct smear method for sample preparation. The SPSS 18.0 software was used for data Statistical analysis. Results By Mass spectrometry identification, when 169 strains were at the species level confidence score and acceptable score level, 91.12％ (154/169) was correctly identified to species level by Autof MS system, 86.39％ (146/169) by ASTA MS system, and 81.66％ (138 / 169) by Bruker Biotyper MS system. The difference of identification accuracy to species level between Autof MS and Bruker Biotyper MS was statistically significant. Besides, the accuracy of genus identi fi cation was 98.82％ (167 / 169) by Autof MS mass spectrometry system and 97.04％ (164 / 169) by both ASTA MicroIDsys and Bruker Biotyper mass spectrometry system. The differences of identification accuracy to genus level among the three MS systems were not significant. Conclusions All of the three MS systems have good identification capability for common microorganisms. Autof MS systems performed slightly better than Bruker Biotyper MS systems in species level identification.
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BACKGROUND:Separating umbilical cord blood stem cells using tubes has low efficiency,and microbial contamination easily occurs during this process,therefore,safety cannot be ensured in clinical application.lt is urgent to find a method for separating umbilical cord blood stem cells to treat femoral head necrosis.OBJECTIVE:To establish a high efficient,safe,and clinically valuable method to separate umbilical cord blood stem cells.DESIGN,TIME AND SETTING:A self-control experiment was performed at the First Department of Surgery,Zhengzhou Second People's Hospital,Institute of Blood Constituent Application,Henan Red Cross Blood Centre between February 2006 and August 2007.PARTICIPANTS:Eight male patients with femoral head necrosis,averaging 40.6 years of age,were included in this study.Of these patients,4 had the history of hormone application.An average of 90 mL umbilical cord blood was harvested from each healthy normal full term neonate from Maternal and Children Health Care Hospital of Zhengzhou City.The quadruple bags used for separating umbilical cord blood stem cells consisted of 1 main bag,1 empty bag,and 2 physiological saline bags,provided by Shandong Weigao Holding,China.METHODS:Within 6 hours after collection,umbilical cord blood was centrifuged in the empty bag of quadruple bag,which was connected with an aseptic filling machine.After centrifugation,partial blood plasma was discarded,and the remaining erythrocytes were thoroughly mixed by adding hetastarch.Five minutes later,the mixture was diluted with physical saline at 1:1.Umbilical cord blood was slowly added into the main bag (at 1:1),in which,human lymphocyte separating medium was pre-added.After cantrifugation,the upper layer of solution,i.e.,monocyte-rich solution,was transferred into another empty bag.Within 24hours of preservation,after suspension with umbilical blood plasma,umbilical cord monocytes were transfused into patients with femoral head necrosis via superficial vein on the hand back,monocytes≥1×108/portion,2 portions once.There were three treatment courses,each involving three transfusion sessions,one session every 4 days,and a 2-3-month interval between two treatment courses.MAIN OUTCOME MEASURES:Cell recovery rate and cell viability of umbilical cord blood monocytes and improvements in clinical symptoms.RESULTS:The separation of quadruple bags could obtain umbilical cord blood monocytes with high recovery rate.Furthermore,microbial contamination hardly occurred in the process of separation.Hip joint pain relieved or disappeared to different extents in all 8 patients,with an effective rate of 100%.Abduction and internal rotation of hip joint,ambulation distance,and gait were markedly improved.At 6 months after cell transplantation,5 patients presented with changed bone density in femoral head necrosis regions,2 showed normal femoral head morphology,and the remaining 1 exhibited no obvious changes.Joint effusion was reduced or disappeared in 12 hips.Magnetic resonance images showed that femoral head morphology had been improved in various degrees in 9 hips,but no changes in 3 hips.No complications,fever,or allergies occurred during and after cell transplantation.CONCLUSION:The method of separating stem cells from umbilical cord blood in junction with aseptic interface technology is highly effective,safe,and clinically valuable.Multiple intravenous transfusions of umbilical cord blood stem cells provide a novel approach for systemic treatment of femoral head necrosis.
