Abstract: Objective To investigate the dynamic changes and clinical significance of specific antibodies in patients with coronavirus disease 2019 (COVID-19). Methods A retrospective study was conducted to collect 141 adult COVID-19 survivors who were followed up in the Eighth Hospital affiliated to Guangzhou Medical University from February 6, 2020, to March 24, 2021. The patients were divided into severe group (severe and critical) and non-severe group (light and ordinary) according to the diagnosis at discharge. The antibody changes of the two groups were compared and analyzed at 1 week, 2 weeks, 1 month, 3 months, 6 months and 1 year after discharge. Results After discharge from hospital, the positive rate of IgG in the severe group was 95.00% after 1 week and 100.00% in the following year, in the positive rate of IgG in the non-severe group was 59.50% after 1 week, 90.08% in 6 months and 76.03% in one year. The level of serum IgG in the severe group was significantly higher than that in non-severe group (Z=-2.441, P=0.015). One-year follow-up: the serum IgG in the severe group was significantly higher than that in the non-severe group (Z=-3.410, P=0.001). The serum IgM level of the severe group after one year follow-up was lower than that of the six months follow-up, the difference was statistically significant (Z=-2.259, P=0.024). The serum IgG and IgM level of the non-severe group after one year follow-up was lower than that of the six months follow-up, the difference was statistically significant (Z=-7.37, P<0.01; Z=3.850, P<0.01). Conclusion The level of serum protective antibody in COVID-19 patients remained high within 6 months after discharge, and remained stable within 1 year after discharge. The antibody titers in the severe group were significantly higher than those in the non-severe group and lasted for at least one year. COVID-19 survivors receive 1 year of natural immune protection, and patients with critical conditions receive immunity for longer periods of time.

Objective To investigate the effect of Alzheimer' s beta-amyloid (Aβ) on the production and the translocation in cytoplasm of retinoid receptor-α (RXRα). MethodsN2awt cells were treated with Aβ peptide or amyloid protein precursor(APP695) transfection. The nucleus were separated from the cytoplasm by kit. The quantity of RXRα in the nucleus and cytoplasm was detected by Westernblot. The translocation of RXRα in the nucleus and cytoplasm of above N2awt cells or of the cortex cells in the brains of Alzheimer' s disease (AD) patients and their normal control groups was observed by immune fluorescence. ResultsIn N2awt cells, the increasing APP or Aβ had no significant effect on the production of RXRα but resulted in RXRα exporting into cytoplasm, the ratio of RXRα in cytoplasm increased from 3.2％ (in control group) to 17.6％ (in APP+ group) and from 3.8％ (in control group) to 14.3％ (in Aβ + group) respectively; compared with normal cortex cells, the translocation of RXRα in the cytoplasm of the cortex cells in the brains of AD increased significantly. ConclusionAβ may affect RXRα exporting into cytoplasm.

SUMMARY Behcet’sdisease(BD)isachronicvascularinflammatorydiseaseofunknowncauses.Itis called intestinal BD,when digestive tract is involved.To investigate small bowel feature of intestinal BD, we now report 5 intestinal BD cases undergone capsule endoscopy from December,2010 to April,2014 in Peking University People’s Hospital.General information,clinical feature and endoscopic feature were presented,and literatures were reviewed.There were 3 male and 2 female patients.Age range was from 23 to 55 years old (median age 40 years old).Disease course was from 3 days to 28 years (median course 9 years).4 patients were diagnosed as systemic BD,and the rest independent intestinal BD.4 systemic BD patients all presented as recurrent oral aphthous as initial symptom and had history of vulvar ulcer and skin lesion.They all had gastrointestinal symptoms,including retrosternal pain (2 cases),he-matochezia (3 cases),diarrhea (3 cases)and abdominal pain (2 cases).1 patient had a history of fis-tula of ileocecal junction and underwent caecectomy.5 patients all underwent whole digestive tract exami-nation by endoscopy,including gastroscopy,colonoscopy and capsule endoscopy.Except of 1 normal re-sult of colonoscopy,all endoscopy results revealed lesions.Capsule endoscopy results of all patients were abnormal.Types of small intestinal lesion were various,including ulceration,erosion,protrusion and vasculopathy.All digestive tract can be involved in BD patients.Capsule endoscopy can evaluate lesions throughout whole digestive tract,especially in small intestine.As a consequence,it is helpful to explain gastrointestinal symptom,increase early diagnostic rate.Intestinal BD (IBD)mainly involves small bow-el,and ileum is the major involved segment,not only limited in ileocecum.The updated perspective of IBD lesion distribution will contribute to differential diagnosis between IBD and Crohn’s disease.This is the first time to report capsule endoscopic feature of BD patients in China.

Objective To investigate the effects of simethicone on the quality of video capsule endoscopy (VCE) examination.Methods A prospective study was performed in 90 patients received VCE examination from February 2010 to October 2014.The randomized table was set according to different dosage of simethicone the patients received,by which patients were divided into three groups.Group 1 (35 cases) received 15 mL simethicone,group 2 (30 cases) received 30 mL simethicone and control group (25 cases) received no simethicone.The small intestinal visualization quality of VCE was scored by segments.Segment A was proximal small intestine (one hour after VCE passing pylorus).Segment B was distal small intestine (one hour before VCE passing ileocecal valve).Segment A and B were scored according to the air bubbles and degree of cleanliness.Gastric transit time,small bowel transit time and VCE completion rate were recorded.Student's t test,Mann Whitney rank sum test and chi square test were performed for statistical analysis.Results The average scores of segment A of group 1,group 2 and control group were 0.58,0.33 and 1.67,respectively,and the average socres of segment B were 0.25,0.00 and 1.17,respectively.The lesion detection rates of group 1,group 2 and control group were 68.6％ (24/35),80.0％ (24/30) and 52.0％ (13/25),respectively,and the differences was statistically significant (x2 =8.238,P=0.016).The detection rate of group 2 was significantly higher than those of group 1 and control group (x2 =7.354 and 9.349,P=0.034 and 0.005).The detection rates of small intestinal erosion of group 1,group 2 and control group were 22.9％ (8/35),70.0％ (21/30) and 32.0％ (8/25),respectively,and the differences was statistically significant (x2=8.714,P=0.013).The detection rate of group 2 was significantly higher than those of group 1 and control group (x2 =10.600 and 7.380,P=0.005 and 0.025).There was no statistically significant difference in the detection rates of ulcer,vascular malformation and protrusion among the three groups (all P＞0.05).The detection rates of lesions＜0.5 cm of group 1,group 2 and control group were 37.1％ (13/35),66.7％ (20/30) and 32.0％ (8/25),respectively,and the differences was statistically significant (x2 =8.242,P=0.016).The detection rate of group 2 was significantly higher than those of group 1 and control group (x2 =9.250 and 7.842,P =0.011 and 0.017).Conclusion Oral adminstration of 30 mL simethicone could obviously decrease air bubbles in small intestine,and increase lesion detection rate of VCE.

Cell therapy has a very promising potential for end-stage liver diseases (ESLD).Fetal liver stem/progenitor cells (FLSPCs) have advantages of safety,high survival and proliferation rates,and a small volume,all which make them ideal for liver disease stem cell therapy.During the early phase of our study,we applied a three-step separation method to enrich FLSPCs and obtained a separation efficiency similar to that of the flow-cell sorting method.Additionally,using a fulminant hepatic failure model in rats,we have demonstrated that FLSPCs can contribute to morphological and functional recovery of the liver.This manuscript will discuss how FLSPCs can be induced to accurately differentiate into hepatocytes and cholangiocytes and how FLSPCs maintain self-renewal.The Notch signaling plays a critical role in regulating the differentiation and self-renewal of many types of stem cells.Our previous findings have shown that the Notch signaling plays an important role in FLSPCs differentiation into hepatocytes.Therefore,the Notch signaling might be involved in the differentiation and self-renewal of FLSPCs.We conducted a study on the regulatory effects and relative molecular mechanisms of the Notch signaling on FLSPCs and found the corresponding interfering target,which might become an index for the clinical application of FLSPCs.

ObjectiveTo discuss the effects of apoptosis and invasion of RBE cells caused by miRNA 21 suppression and further investigate the potential role of miRNA-21 plays on target mRNA regulation. MethodsThe RNAi technology was employed to suppress the expression of RBE cells.The changes in RECK mRNA and protein expressions were detected by RT-PCR and Western blotting respectively. Changes occurred in apoptosis was closely monitored by flow cytometry (FCM). The invasion of RBE cells was analyzed in vitro by invasion assay (transwell). ResultsThe expression of miRNA-21 was clearly suppressed while the RECK mRNA and protein were over-expressed. The rate of apoptosis was significantly accelerated and there was a dramatic decrease in RBE cells' ability to invade after miRNA-21 knockdown. ConclusionThrough miRNA-21 suppression, the rate of apoptosis of RBE cells was accelerated whereas their invasion ability was greatly reduced. RECK was found to be the target gene of miRNA-21 which participates in the regulation process of regulation.

Objective Many studies showed that Ca~(2+) channel blocker could prevent and treat right ventricular hypertrophy(RVH) induced by chronic hypoxia.To further identify the mechanism,we investigated the effect of Ca~(2+) channel blocker on the levels of myocardial calcineurin A?mRNA(CnA?)in RV and plasma nitric oxide(NO),NO synthase and endothelin-1(ET-1) in rats with chronic hypoxia.Methods 30 rats were divided into three groups by randomized block design: treatment group with Amlodipine Besylate ablets [(30 mg?kg~(-1)?d~(-1)),administered via gavage],chronic hypoxia group,and control group.The rats in treatment group and chronic hypoxia group were exposed to normobaric chronic hypoxia [(10.0?0.5)% O_2 ] for 21 days.On the 21st day of experiment,all rats were sacrificed and the hearts were collected for measuring the weight.Blood samples were also drawn from the ventricles for measuring plasma NO,iNOS and ET-1 levels.CnA?mRNA levels in RV were measured by RT-PCR.Results ⑴The RV/(LV+S)、RV/BW ratios were significantly higher in chronic hypoxia group than those of control group and treatment group(P

ObjectiveTo investigate the correlation between clinical data and pathological stage in patients with primary biliary cirrhosis (PBC) and to provide guidance for clinical diagnosis and treatment. MethodsThe clinical data of 54 PBC patients were collected for analyzing the correlation between the clinical data and pathological stage. The clinical data included biochemical parameters, immunological markers, and autoantibodies. Biopsy of the liver was used for the pathological staging of PBC. For the continuous data of normal distribution, analysis of variance was applied for comparisons between groups; for continuous data of skewed distribution, Wilcoxon rank sum test was used. For categorical data, chi-square test was used. Correlation analysis was performed by Pearson correlation and logistic regression. ResultsAmong the 54 patients, the male-to-female ratio was 1∶5; the mean age was 48.9±9.3 years; pathological stage Ⅰ was identified in 15 cases, stage Ⅱ in 18 cases, stage Ⅲ in 12 cases, and stage Ⅳ in 9 cases, and patients with stage Ⅳ disease were significantly older than the other patients (P＜0.05). Total bilirubin (TBil), alkaline phosphatase, prothrombin time, IgA, IgG, and SP200 were positively correlated with pathological stage (r=0.592, 0.343, 0.281, 0.388, 0.274, and 0.320, respectively, P＜0.05), while a negative correlation was found between albumin and pathological stage (r=-0.569, P=0.000). Multivariate analysis revealed an independent correlation between TBil level and pathological stage (P=0.039). Patients with the same pathological stage might have different clinical stages, while those with the same clinical stage might have different pathological stages. ConclusionsThe same pathological stage may appear in different clinical stages. TBil level is an independent predictive factor for pathological stage in PBC patients.

AIM: To study the role of calcineurin in the progression of right ventricle cardiac hypertrophy in the chronic hypoxia rats and examine the effect of Ca 2+ channel blockers on the activation of calcineurin. METHODS: Sixty rats were divided into three groups: treatment group with amlodipine besylate ablets, chronic hypoxia group, normal control group with normal oxygen. The rats in treatment group and chronic hypoxia group were exposed to normobaric chronic hypoxia(10?0 5)% O 2 for 21 days. All hearts were removed immediately after dissection for further investigation. RESULTS: (1)The RV/(LV+S),RV/BW were significantly higher in hypoxia group than that of control group and treatment group( P

OBJECTIVE: To explore the composition characteristics of traditional Chinese medicine (TCM) syndromes in patients with acute ischemic stroke of yin or yang syndrome by investigating the characteristics of TCM syndromes at different periods after onset. METHODS: One thousand two hundred and forty-six patients with acute ischemic stroke were admitted in twenty hospitals. According to the "diagnostic criteria of syndrome differentiation of stroke", the characteristics of syndromes in the patients were investigated at the periods of 1-3 days, 4-10 days and 11-30 days after they had ischemic stroke. General distribution of six basic syndromes was compared between the patients with yin syndrome and the patients with yang syndrome at the three periods. The six basic syndromes were wind syndrome, pathogenic fire syndrome, phlegm syndrome, blood stasis syndrome, qi deficiency syndrome, and syndrome of yin deficiency and yang hyperactivity. RESULTS: The percentages of wind, pathogenic fire, and phlegm syndromes in the patients were decreased at the period of 11-30 days as compared with the period of 1-3 days (87.1% vs 79.3%, 52.1% vs 38.7% and 67.1% vs 57.4% respectively, P<0.01). However, the percentages of the syndromes of blood stasis, qi deficiency, and yin deficiency and yang hyperactivity were similar at the three periods (P>0.05). There were no differences in the distribution of yin and yang syndromes among the three periods (P>0.05). The percentages of syndromes of wind, pathogenic fire, phlegm, and yin deficiency and yang hyperactivity were higher (P<0.01), and the percentages of syndromes of blood stasis and qi deficiency were lower (P<0.05, P<0.01) in patients with yang syndrome than in patients with yin syndrome. The complex of three syndromes was the most frequent composition pattern in the patients at the three periods. The percentages of complex syndromes of four or five syndromes were higher, and the percentages of single-syndromes and complex syndromes of two syndromes were lower in patients with yang syndrome than in patients with yin syndrome (P<0.05, P<0.01). The most frequent complex syndromes in patients with yin syndrome were complex syndrome of wind, phlegm, blood stasis and qi deficiency, and complex syndrome of wind, phlegm and qi deficiency; while the most frequent complex syndromes in patients with yang syndrome were complex syndrome of wind, pathogenic fire, phlegm and qi deficiency, and complex syndrome of wind, pathogenic fire and phlegm. CONCLUSION: The main discrimination between the yin and yang syndromes is that the yang syndrome is characterized by pathogenic fire. The syndromes of phlegm, qi deficiency, and blood stasis are not associated with the diagnosis of yin or yang syndrome.