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Objective To determine the serum IgM and IgG antibody levels post-COVID-19 vaccination， and provide scientific evidence for COVID-19 antibody response after vaccination. Methods A total of 980 healthy persons were included in Kunming Third People’s Hospital from July through August， 2021， which had been vaccinated with COVID-19 vaccines and then tested for anti-SARS-CoV-2 IgM and IgG antibodies. Results After the COVID-19 vaccination， 469 persons （positive rate， 47.86%） were positive for anti-IgG antibody. Of them， 75 were males with （positive rate， 39.06%）， and the average IgG level was 0.618 （0.180， 2.526） AU·mL-1［M（Q1，Q3）］； 394 were females （50.00%）， and the IgG level was 0.999 （0.305， 3.334） AU·mL-1. In addition， 53 persons （5.41%） were anti-IgM antibody positive. Of them， 14 were males （positive rate， 7.29%）， and the average IgM level was 0.057 （0.026， 0.195） AU·mL-1； 39 were females （4.95%）， and the IgM level was 0.047 （0.027， 0.110） AU·mL-1. The positive rate of anti-IgG antibody was highest in those aged ≤30 years， which was 51.02% in male （n=25） and 55.88% in female （n=133）. The anti-IgG response differed significantly by gender （χ2=7.401， D=0.135 1， P<0.05）， whereas the anti-IgM response was not significantly different （χ2=1.656， P>0.05）. Among the age groups， anti-IgG antibody level was higher in those aged ≤30 and 51-70 years， with 158 （55.05%） and 122 （52.36%） persons， respectively； the average antibody level was 1.209 （0.426， 4.386） AU·mL-1 and 1.074 （0.191， 7.670） AU·mL-1， respectively. The differences in the positive rates of IgG and IgM antibodies and the levels of IgG antibodies among different age groups were statistically significant （P<0.05）. Using Kruskal-Wallis test and Spearman correlation analysis， it showed a high correlation between the IgG and IgM antibodies （r=0.836 4， H=64.82， 20.09， P<0.05）. Conclusion The Anti-SARS-CoV-2 IgG antibody remains high six months post-COVID-19 vaccination， while anti-IgM antibody is low. The IgM and IgG response are higher in the young and elderly. The response differs by gender and age， demonstrating a correlation.
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Objective To explore the conversion rate of iodate ions (IO3-) being reduced to iodide ions (I-) by ascorbic acid (C6HsO6,VC) in simulated human gastric juice,and to provide references for further safety evaluation of edible salt iodized with potassium iodate.Methods An ion chromatography method was developed to detect iodide ions in simulated gastric juice.The conversion rate of iodate ions being reduced to iodide ions was used as the index for scavenging rate of iodate ions.In simulated gastric juice in vitro and in 37 C water bath,the scavenging effects of VC on iodate ions were determined in simulated gastric juice with different VC concentrations and simulated gastric juice acidities,as well as for different reaction time.Ion chromatography column:Dionex IonPac AS19 (250 mm × 4.0 mm);eluent:KOH 30 mmol/L (online produced),isocratic eluting,flow rate 1.0 ml/min,injection volume 100 μl,and detected by a conductivity detector.Results Performance of the method:within the range of 0-5 000 μg/L,iodide ions concentration and the chromatographic peak area had a good linearity (correlation coefficient r =0.999 7),and the detection limit of iodide ions was 20 μg/L.For quantification of iodide ions in simulated gastric juice,the relative standard deviation (RSD) of repeated measure for 6 times was ＜ 2.0％,the standard addition recovery rate was 97.6％-102.4％,and the overall average recovery rate was 99.4％.In the simulated gastric juice with a pH of 1.4 containing 5 mg/L and ≥ 10 mg/L VC,the reaction time to achieve 100％ conversion rate of iodate ions being reduced to iodide ions was 5 min and 2 min,respectively.In the simulated gastric juice with a pH of 3 containing 10 mg/L ascorbic acid,the reaction time to achieve 100％ conversion rate was 15 min.VC quantitatively reduced iodate ions to iodide ions by the stoichiometric relationship between reactants of the reduction reaction equation,and every 100 μg VC quantitatively reduced 24.0μg of iodine in iodate to iodide ions.Conclusions In simulated gastric juice,the reaction of iodate ions being reduced to iodide ions by VC is a stoichiometric reaction with relatively fast reaction rate,the scavenging rate of iodate ions by VC within the concentration level in human gastric juice can reach 100％.The results prompt that the iodate ions from edible salt iodized with potassium iodate in daily diet are reduced to iodide ions mainly in the human stomach.
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Objective To establish a method for determination of iodine in urine with no need for base urine match by inductively coupled plasma mass spectrometry (ICP-MS).Methods The diluent which contains 2.5 g/L N2H4·2HCl-1.0 g/L NH4C1-0.50％HC1-2.0％C2H5OH were used to eliminate the matrix interference in determination of iodine in urine by ICP-MS.The standard solutions and the urine samples were all diluted in a ratio of 19:1 (diluents:sample) before testing.The methodological evaluation of this new method was done through standard curve linearity,sample detection limit,precision and accuracy in determining urinary iodine.And the determine results were compared with the current urinary iodine arsenic cerium catalytic spectrophotometry standard method (WS/T 107.1-2016,hereinafter referred to as the standard method).Results The linear range of the calibration curve was 0-1 000 μ.g/L and the linear correlative coefficient was 0.999 9.The detection limit for urinary iodine was 0.4 μg/L (0.25 ml of urine was tested).Precision:The average coefficient of variation (CV)was 0.8％ with a range of 0.2％-1.7％ (n =6) when measuring 33 urine samples with iodine concentration of 26.5-854.4 μμg/L.Accuracy:The iodine standard of 40-400 μg/L was added for recovery test.The average recovery was 99.6％ with a range of 94.3％-103.4％ when measuring 24 urine samples with iodine concentration of 26.5-858.3 μg/L.The test results of 8 urinary iodine national standard materials with iodine concentration ranged from 64.5 to 883.0 μg/L were all within the given value range and the relative deviations were all below 3.0％ (n =12).No significant difference was found between the results of the 51 urine samples determined by the standard method (WS/T 107.1-2016) and the new method (t =0.836,P ＞ 0.05).Conclusions The new method to determine iodine in urine with no need for base urine match is successful established.This method has wide linear range,high sensitivity,good precision,accuracy and anti-interference ability,and is easy to be used and quickly to be analyzed of the test results,and is suitable for widely application in determining urinary iodine.
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Objective To explore the rationality of correcting urinary iodine (UI) concentration by using urine specific gravity (U-SG).Methods Weighing method and refractometer method were used respectively to measure specific gravity of 10-30 g/L mass concentration of different inorganic salts (sodium chloride,sodium sulfate,ammonium biphosphate) and organic matters(urea,glucose,glycine) aqueous solution,and urine plus 10-30 g/L sodium chloride or urea.UI concentrations in urine samples of 27 pregnant women respectively were expressed by direct method,weighing method U-SG correction and refractometer method U-SG correction.One random urine sample was collected for six batches in different seasons from children aged 8-10 and pregnant women for determination of U-SG and UI concentration.UI concentration was determined by arsenic cerium catalytic spectrophotometry (WS/T 107-2006).Results ①Measured by weighing method,specific gravity of inorganic salt (sodium chloride,sodium sulfate,ammonium biphosphate) aqueous solution was significantly greater than that of organic matters (urea,glucose,glycine) aqueous solution which had the same mass concentration.The specific gravity of 10 g/L sodium chloride aqueous solution was 1.008,and that of 30 g/L urea solution was 1.006.②Measured by weighing method,10 g/L sodium chloride was added to 3 urine samples separately.Accordingly the increases of USG were 0.006,0.008 and 0.007,respectively.Otherwise,the increases of U-SG were 0.003,0.002 and 0.004,respectively,when adding 10 g/L urea.~he median results of UI concentrations in urine samples from 27 pregnant women were 106.4,165.2 and 211.8 μg/L,respectively,expressing obtained by direct method,weighing method USG correction and refractometer method U-SG correction.④The determination results of six batches urine collected from children aged 8-10 in different seasons,the median results of U-SG measured by refractometer method were 1.019 0-1.021 2,the median UI concentration results obtained by direct method and refractometer method U-SG correction were 134.5-181.7 μg/L and 157.7-190.4 μg/L.The determination results of six batches urine samples of pregnant women in different seasons,the median results of U-SG measured by refractometer method were 1.013 4 -1.017 1,the median UI concentration results obtained by direct method and refractometer method U-SG correction were 96.2-138.9 μg/L and 135.2-181.6 μg/L.Conclusions The change of sodium chloride concentration in urine is the most important reason for the change of U-SG.In China,the main source of UI is the intake of edible iodized salt.Iodized salt intakes directly affect the U-SG and UI concentration.If the U-SG is used to correct the UI concentration,there will be a phenomena that the lower intake of iodized salt the lower U-SG.So the UI concentration was falsely increased significantly after correction.Conversely higher intakes of iodized salt caused higher U-SG.The UI concentration was falsely reduced significantly after correction.Therefore,U-SG cannot be used to correct the UI concentration.
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Brain-derived neurotropic factor (BDNF) contents in blood and cerebrospinal fluid (CSF) were detected by ELISA method in 30 cases of hypertensive cerebral hemorrhage (HCH group) and 30 healthy subjects (control group).The performance and neurological functions of patients were evaluated by National Institutes of Health Stroke Scale( NIHSS),Hamilton Depression Scale ( HAMD),Barthel Index of Daily Living Skills.The result showed that the contents of BDNF in blood and CSF of HCH patients in recovery stage were significantly higher than those in acute stage and those of control group ( P ＜ 0.05 ) ; the contents of BDNF in blood and CSF were negatively correlated with neurological impairment degree ( P ＜0.05).The results suggest that BDNF in the blood or the CSF may promote the recovery of neurological function in patients with hypertensive cerebral hemorrhage.
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Objective To evaluate the effect of hyperbaric oxygen (HBO) therapy on pathological and ul-trastructure changes in cortical neurons after model focal cerebral isehemia. Methods Middle cerebral artery occlu-sion (MCAO) using the Zea-Longa method was administered to 48 Sprague-Dawley rats, who were subjected to cere-bral ischemia for 2 hours followed by reperfusion. They were then randomly divided into a treatment group and a con-trol group. HBO was applied to the rats in the treatment group, and any changes in the pathology and uhrastructure of neurons in the cortex were observed at preset time points. Results The infarct volume was significantly smaller inthe treatment group than in the control group, and pathological changes in brain tissue were also milder. Conclu-sions HBO could help protect cortical neurons in acute cerebral ischemia.