Aim To determine the effect of SYL934 , a novel immunosuppressant, on skin allograft rejec-tion. Methods HTRF-IP1 assay was used to evaluate the agonistic activity of SYL934-P, the active form of SYL934 in vivo, on S1P1 and S1P3 in vitro. SD rat peripheral blood lymphocytes ( PBL ) test and heart rate test was used to assess the in vivo immunosuppres-sive effect and heart rate effect of SYL934 . Mice skin graft transplantation experiment was used to observe the effect of SYL934 on skin allograft refection. ResultsSYL934-P selectively activated S1 P1 but not S1 P3 in vitro. Single orally administration of SD rats with
SYL934 decreased the PBL significantly and played an obviously immunosuppressant role, but did not affect the heart rate. Daily orally administration of mice with SYL934 significantly increased the survival rate of al-lografts of skin slice in mice. Conclusion SYL934 has great selectivity in vitro and good activity in vivo, which indicated it potential use as an anti-rejection drug in skin transplantation.

Syl948 is a synthesized selective S1P1 agonist with novel structure. HTRF-IP1 test indicated that Syl948-P, the active form of Syl948 in vitro, has strong activity against S1P1 (EC50: 83 +/- 16 nmol x L(-1)), but its effect on S1P3 was very weak (EC50: 1 026 +/- 90 nmol x L(-1)). In SD rats, oral administration of Syl948 10 mg x kg(-1) significantly decreased the peripheral blood lymphocytes (PBL), with the maximal PBL inhibition rate of 63%, which was as similar as equal dose of fingolimod (FTY720). Oral administration of Syl948 10 mg x kg(-1) had no effect on heart rate of SD rats, which was better than FTY720. Daily oral administration with Syl948 (2 or 4 mg x kg(-1)) significantly prolonged the survival time of the allografts of skin slice on mice. In summary, the above results demonstrated that Syl948 has great selectivity in vitro and good activity in vivo, which indicated its potential use as an anti-rejection drug in skin transplantation.

Objective:To explore the evaluation of dual-parameter three dimension arterial spin labelling(3D-ASL)perfusion imaging on blood-supply situation of patients with chronic middle cerebral artery occlusion(CMCAO)and the relationship between that and cerebral infarction area.Methods:A total of 112 patients with unilateral CMCAO admitted to Handan Central Hospital from April 2019 to December 2021 were selected,and all of them were divided into a compensatory group(50 cases)with anterior cerebral artery(ACA)leptomeningeal anastomoses(LMA)and an uncompensated group(62 cases)according to the results of digital subtraction angiography(DSA)examination.The results of diffusion weighted imaging(DWI),magnetic resonance angiography(MRA)and dual-parameter 3D-ASL detection were respectively analyzed,and the clinical data,3D-ASL parameters and the incidence of cerebral infarction between the two groups were compared.The influence factors of compensation were further analyzed.The receiver operating characteristics(ROC)curve of LMA diagnostic value of CMCAO patients was drawn according to cerebral blood flow values[post label delay(PLD)=1.5 s,2.5 s)].The 3D-ASL parameters of patients with different cerebral infarction areas were compared,and the relationship between 3D-ASL parameters and cerebral infarction area was compared.Results:The apparent diffusion coefficient(ADC)at the side of lesion of CMCAO patients was(0.31±0.10),and cerebral blood flow values at 1.5s and 2.5s were respectively(25.67±4.25)and(54.09±4.49),which were significantly lower than those at the side of healthy,and the differences were statistically significant(t=27.591,34.210,3.913,P<0.05),respectively.The differences of cerebral blood flow values(1.5s and 2.5s)between compensatory group and uncompensated group were significant(t=5.584,4.090,P<0.05),respectively.The results of logistic regression analysis showed that age,stroke,cerebral infarction area and cerebral blood flow values(1.5 s and 2.5 s)were influencing factors on LMA compensation of CMCAO patients(OR=4.187,6.604,0.482,5.681,5.807,P<0.05),respectively.The ROC values showed that the area under curve(AUC)of 3D-ASL were respectively 0.720 and 0.812 in diagnosing LMA when PLD were respectively 1.5s and 2.5s.The proportion of normal and lacunar infarctions in the compensatory group was significantly higher than that in the uncompensated group,while the proportions of middle and small infarction,and large area infarctions of the compensatory group were significantly lower than those of the uncompensated group,and the difference was statistically significant(t=28.062,P<0.05).The difference in cerebral blood flow values(1.5s)among patients with different infarct areas was statistically significant(t=0.202,P<0.05).The cerebral blood flow value(1.5s)of 3D-ASL was negatively correlated with the area of cerebral infarction(r=-0.261,P<0.05).Conclusion:Dual parameter 3D-ASL can non-invasively and visually assess the compensatory status of LMA of patients with unilateral CMCAO.The blood flow perfusion of middle cerebral artery(MCA)at the side of lesion is related to the area of cerebral infarction.When the PLD is 1.5s,the sensitive response can be conducted on this,so as to provide objective and reliable basis for clinical diagnosis and treatment and curative effect.

Objective: To establish a method for the determination ofsamarium oxide and lanthanum oxide by inductively coupled plasmamass spectrometryin the air of workplace. Methods: Samarium, lanthanum and their compounds in the air of workplace were collected through microporous filter. The samples were digested by nitricacid and perhydrol (V/V=4∶1) and detected by inductively coupled plasmamass spectrometry. Results: The linear range ofsamarium oxide and lanthanum oxide was 0-50.00 μg/L, Sm₂O₃: y=0.0119x, r=0.9999; La₂O₃: y=0.0617x, r=0.9998. The detection limits were less than 0.1 μg/L, and the minimum detection concentration were less than 1.52×10^-5 mg/m³. The sampling efficiency were 100%, the recovery rates were 95.70%-102.01%, and the precision were 0.78%-1.58%. Conclusion The indicators established in this study are conformed with the requirements of Chinese Occupational Standars of GBZ/T 210.4-2008, "The Guidelines for the Development of Occupational Hygiene StandarsMehods Part 4: Determination of Chemical Substances in the Air of Workplace".