ObjectiveTo observe the effect of ginsenoside Rg₁ （G-Rg₁） on the biological activity of cryopreserved Schwann cells （SCs） of the rat sciatic nerve and explore the feasibility of G-Rg₁ in reducing the cryopreservation-induced injury in SCs. MethodBilateral sciatic nerves of SD rats were randomly divided into a fresh group， a blank group， and five G-Rg₁ groups of different doses （1×10^-7， 1×10^-6， 1×10^-5， 1×10^-4， and 1×10^-3 mol·L^-1）. The nerves in the blank group and the G-Rg₁ groups were preserved in liquid nitrogen solutions containing 0， 1×10^-7， 1×10^-6， 1×10^-5， 1×10^-4， and 1×10^-3 mol·L^-1 G-Rg₁ for four weeks. The apoptosis of SCs was detected by TdT-mediated dUTP-biotin nick end labeling （TUNEL）/S100 immunofluorescence staining. The expression of cysteinyl aspartate-specific protease （Caspase）-9， Caspase-3， major histocompatibility complex （MHC）-Ⅰ， and MHC-Ⅱ was detected by Western blot. Subsequently， all nerves were cultured in the incubator at 37 ℃ with 5% CO₂ for 7 days. The expression of glial cell line-derived neurotrophic factor （GDNF） and nerve growth factor （NGF） was detected by Western blot. In addition， the above cryopreserved nerves in the blank group and the 1×10^-6， 1×10^-5， and 1×10^-4 mol·L^-1 G-Rg₁ groups were transplanted to the Wistar rats by allografting （blank transplantation group and the 1×10^-6， 1×10^-5， and 1×10^-4 mol·L^-1 G-Rg₁ transplantation groups）， and fresh sciatic nerve allograft and isograft control group were set up. Sixteen weeks after transplantation， compound muscle action potential （CMAP） and nerve conduction velocity （NCV） were measured by electrophysiology. Nerve filament （NF）200 immunofluorescence staining， transmission electron microscopy， and toluidine blue staining were used to analyze the histology of the regenerated nerves. ResultCompared with the fresh group， the blank group and the G-Rg₁ groups showed increased expression of Caspase-9， Caspase-3， and the apoptosis of SCs （P<0.05，P<0.01） and decreased expression of GDNF， NGF， MHC-Ⅰ， and MHC-Ⅱ （P<0.01）. Compared with the results in the blank group， the expression of Caspase-9 and Caspase-3 decreased in the 1×10^-7， 1×10^-6， 1×10^-5，1×10^-4 mol·L^-1 G-Rg₁ groups （P<0.01）， and the apoptosis of SCs was reduced in the 1×10^-7-1×10^-4 mol·L^-1 G-Rg₁ groups（P<0.05，P<0.01） and increased in the 1×10^-3 mol·L^-1 group （P<0.05）， while the expression of GDNF and NGF increased in the 1×10^-7， 1×10^-6， 1×10^-5，1×10^-4 mol·L^-1 G-Rg₁ groups and decreased in the 1×10^-3 mol·L^-1 group （P<0.05）. There was no statistical significance in the expression of MHC-Ⅰ and MHC-Ⅱ between the blank group and the G-Rg₁ groups. Compared with the 1×10^-7 mol·L^-1 and 1×10^-3 mol·L^-1 G-Rg₁ groups， the 1×10^-6 1×10^-5， 1×10^-4 mol·L^-1 G-Rg₁ groups showed decreased expression of Caspase-3 and the apoptosis of SCs （P<0.05，P<0.01） and increased expression of GDNF and NGF （P<0.05，P<0.01）. There was no statistical significance in MHC-Ⅰ and MHC-Ⅱ expression among G-Rg₁ groups. Sixteen weeks after transplantation， compared with the isograft group， the blank transplantation group and the G-Rg₁ transplantation groups showed decreased CMAP， NCV， myelin sheath thickness， and number of myelinated nerve fibers （P<0.01）， and the 1×10^-6 and 1×10^-4 mol·L^-1 G-Rg₁ transplantation groups showed decreased NF200 （P<0.01）. Compared with the allograft group， the blank transplantation group and the G-Rg₁ transplantation groups showed increased CMAP， NCV， NF200， myelin sheath thickness， and number of myelinated nerve fibers （P<0.05，P<0.01）. Compared with the blank transplantation group， the G-Rg₁ transplantation groups showed increased CMAP， NCV， NF200， myelin sheath thickness， and number of myelinated nerve fibers （P<0.05，P<0.01）. Among all groups of G-Rg₁ transplantation， each index of the 1×10^-5 mol·L^-1 G-Rg₁ transplantation group was superior to that of the 1×10^-4 and 1×10^-6 mol·L^-1 G-Rg₁ transplantation group （P<0.05）. ConclusionG-Rg₁ at a certain centration can maintain the biological activity of cryopreserved SCs of rat sciatic nerve， alleviate the cryopreservation-induced injury of rat sciatic nerve， and promote nerve regeneration after allograft.

OBJECTIVE：To compare the protective effects model mice between the aboveground and underground parts of Astragalus membranaceus on immunosuppression ，and to provide reference for further utilization and development of A. membranaceus. METHODS ：A total of 240 ICR mice were divided into 4 batches，60 mice in each batch ，with half male and half female. Each batch of mice were randomly divided into blank group ，model group ，A. membranaceus aboveground part and undergroud part low-dose and high-dose groups （3，6 g/kg，by crude drug ）according to body weight and sex ，with 10 mice in each group. Blank group and model group were given normal saline intragastrically. A. Membranaceus groups were given corresponding concentration of drug intragastrically ，10 mL/kg，once a day ，for consecutive 30 days. Except for blank group ， other groups were intraperitoneally injected with cyclophosphamide 40 mg/（kg·d）for consecutive 3 days，since 24th day of treatment，to establish immunosuppression model. The levels of serum immunoglobulin （IgG，IgM，IgA），inflammation factors [nitric oxide ，interleukin-2（IL-2），IL-6，tumor necrosis factor-α] and half hemolysis value were detected in each group. Body weight ，thymus index ，spleen index ，phagocytic index ，activity of natural killer （NK）cell，splenic lymphocyte proliferation ability，dinitrofluorobenzene-induced delayed metamorphosis reaction in mice （by weight difference between left and right ears ） and the number of hemolytic plaque were determined. RESULTS ： Compared with blank group ， the serum levels of immunoglobulin，body weight ，thymus index ，spleen index ，phagocytic index ，NK cell activity ，the proliferation ability of splenic lymphocyte，the number of hemdytic plaque and half hemolysis value were decreased significantly in model group （P＜0.05）， while inflammation factor level as well as weight difference between left and right ears were increased significantly （P＜0.05）. Compared with model group ，above indexes of mice in A. membranaceus groups were improved significantly ，in dose-dependent manner（P＜0.05）. Compared with A. membranaceus undergroud part group ，above indexes of A. membranaceus aboveground part group were improved significantly （P＜0.05）. CONCLUSIONS ：Aboveground and underground part of A. membranaceus both have pretective effect on immunosuppression model mice ，and the effect of aboveground part of A. membranaceus is stronger than underground part of A. membranaceus .

Objective:To understand the epidemiological characteristics of imported COVID-19 cases in Guangzhou and provide scientific basis for the prevention and control of the disease.Methods:The data of imported COVID-19 in Guangzhou reported as of April 1, 2020 were collected from National Notifiable Disease Report System of China. The software Excel 2010 and SPSS 19.0 were applied for data cleaning and statistical analysis.Results:As of April 1, 2020, a total of 103 imported COVID-19 cases had been reported in Guangzhou, in which 92 were confirmed cases and 11 were asymptomatic infection cases. The number of the confirmed imported cases accounted for 11.4 % (92/806) in of the total in China at the same time. The male to female ratio of the cases was 1.58∶1 (63∶40). The median age of the cases was 31 years ( P 25- P 75:22-40 years), range of age was 11-63 years. The main occupational distributions of the cases were business services (41/103, 39.8 %) and students (36/103, 35.0 %). The imported cases whose destinations were 19 provinces and municipalities rather than Guangdong after entering the country accounted for 43.7 %. The main source countries of infections were the United Kingdom (27/103, 26.2 %), the Philippines (13/103, 12.6 %), the United States (13/103, 12.6 %) and Nigeria (7/103, 6.8 %). There were 34 inbound flights from which the imported COVID-19 cases were detected, in which 10 flights (10/34, 29.4 %) were found to carry more than 3 cases, with an average voyage time of (11.14±0.53) hours. A total of 29 imported cases(28.2 %) showed symptoms before entering the country, and 65 cases (63.1 %) had been isolated before the onset of the disease. The mean free activity time of the isolated cases after the onset was (6.76±0.79) days. The average number of the imported cases’ close contacts was 53. There were 13 clusters of COVID-19 caused by the imported cases, involving 36 cases (including 1 imported associated case). Conclusions:The sources of the imported COVID-19 cases in Guangzhou were widely distributed, and no cases had been found to be infected on the flights. In the early stage of the imported epidemic, there was high risk for the spread of the epidemic. Strengthened prevention and control of imported COVID-19 effectively reduced the of transmission risk of COVID-19 in communities.

Objective To investigate the effects of triptolide (T10) on biological activity of sciatic nerve in cold preservation and nerve regeneration after allogeneic transplantation. Methods Cell Counting Kit-8 (CCK-8) was used to test the proliferation of SCs in logarithmic phase in 1×10-6 mol/L, 1×10-7 mol/L, 1×10-8 mol/L and 1×10-9 mol/L of T10 solution. The sciatic nerves from Sprague-Dawley rats were pretreated in 0 mol/L, 1×10-6 mol/L, 1×10-7 mol/L, 1×10-8 mol/L and 1×10-9 mol/L of T10 solution at 4 ℃ or 37 ℃ for 24 hours (n = 6). The expression of nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) was detected with Western blotting. Other sciatic nerve fragments were randomly divided into fresh nerve group (group A, n = 30), DMEM preservation group (group B, n = 30), T10 preservation group (group C, n = 30), T10 pretreatment DMEM preservation group (group D, n = 30) and T10 pretreatment T10 preservation (group E, n = 30), and were stored under 4 ℃ for four weeks. Calcein-AM/PI double staining laser confocal microscope and flow cytometry were used to detect the living cells and dead cells. The expression of the major histocompatibility complex (MHC)-I, MHC-II and intercellular cell adhesion molecule-1 (ICAM-1) was detected with Western blotting. The corresponding sciatic nerves were used to repaire 10 mm defects in Wistar rats (named groups A', B', C', D' and E'), and fresh sciatic nerve from Wistar rats were also used to do it (group F'). Compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) were tested 16 weeks after transplantation, and then the grafts were observed for the nerve regeneration. Results SCs proliferated as the controls in the T10 solution with a concentration of 1×10-9 to 1×10-7 mol/L (P > 0.05). The expression of all the neurotrophic factors was more under 37 ℃ than under 4 ℃ in all the concentrations of T10 solution, and it was the most in the concentration of 1×10-8 mol/L whenever under 37 ℃ or 4 ℃ (P < 0.05). After four weeks of cold preservation, compared with groups B, C and D, the living nerve cells were the most in group E, and the expression of MHC-I, MHC-II and ICAM-1 was the least (P < 0.05). CMAP, MNCV and the never regeneration were better in group E' than in groups A', B', C' and D' (P < 0.05). A large number of myelinated nerve fibers were observed in groups E' and F', uniformity in size, wide distribution, and with myelin sheath, compared with those in groups A', B', C' and D'. Conclusion A certain concentration of T10 can induce the sciatic nerve of rats to express neurotrophic factor in vitro, which can improve the biological activity of cold preservation nerves, reduce the immunogenicity, and promote the regeneration of recipient nerve after allogeneic transplantation. It is even better to be pretreated with T10 before cold preservation.

OBJECTIVE:To observe clinical efficacy and safety of Bushen sanhan tongluo decoction combined with moxi-bustion and celecoxib in the treatment of knee osteoarthritis (KOA). METHODS:A total of 70 KOA patients were selected from Chongqing Kanghua Hospital during May 2014-Dec. 2015,and then divided into observation group and control group ac-cording to odd and even number,with 35 cases in each group. Control group was given Celecoxib capsule 0.2 g,qd;observa-tion group was additionally given Bushen sanhan tongluo decoction(one dose a day,300 mL,decocted with water,taking it 3 times in the morning,noon and night)and moxibustion. A treatment course lasted for 4 weeks,and both received 2 courses of treatment. Clinical efficacies as well as TCM syndrome score,VAS score,WOMAC score,lab indexes,joint condition be-fore and after treatment,the occurrence of ADR were compared between 2 groups. RESULTS:Total response rate of observa-tion group (85.71％) was significantly higher than control group (68.57％),with statistical significance (P<0.05). Before treatment,there was no statistical significance in above indexes between 2 groups (P>0.05). After treatment,TCM syn-drome score,VAS score,WOMAC score,erythrocyte sedimentation rate,CRP level and knee swelling score of 2 groups were decreased significantly,compared to before treatment;those indexes of observation group were significantly lower than those of control group,with statistical significance(P<0.05). There was no statistical significance in the number of bone fric-ative joint between 2 groups before and after treatment (P>0.05). There was no statistical significance in the incidence of ADR (5.71％ vs. 2.86％) between 2 groups (P>0.05). CONCLUSIONS:Bushen sanhan tongluo decoction combined with moxibustion and celecoxib can improve clinical symptoms,relieve joint pain,joint inflammation and swelling of KOA pa-tients with good safety.

Objective To evaluate X-ray and MRI features of limbs in childhood acute leukemia.Methods Thirteen children with acute leukemia in our pediatric hematology ward were recruited.Allpatients were pathologically diagnosed by bone marrow aspiration and complained of bone or joint pain in the first visit.ConventionaI X-ray and MRI examinations of algesic sites were performed before clinical treatment and after complete remission.MR images were obtained with SE-T1WI,SE-T2WI and T2WI-fat suppressed sequences and symmetria bilateralis was requested while scanning.X-ray and MRI manifestations were evaluated and compared.Resuits All 13 patients had received X-ray examinations.Among them,6 had normal X-ray findings,whereas the other 7(14 sites)showed various abnormalities including radiolucent metaphyseal bands(5 sites),periosteal reaction(3 sites),osteapenia(2 sites),mixed lesions(lysissclerosis,1 site),and permeative pattern(3 sites).The number of patients for MRI examinations was 8(11 sites).Among them,6(9 sites)showed bone marrow infiluration and bone marrow necrosis accompanied by normal X-ray findings,another 2(2 sites)showed bone marrow infiltration associated with radiographic abnormalities of periosteal reaction and radiolucent metaphyseal bands.Four cases were followed up within 1 week when reached complete remission by chemotherapy.MR images features included reduced sizes of bone marrow infiltration lesions associated with increased signal intensity on T1WI,and disappearance of double-line sign on bone marrow necrosis accompanied by signal homogenization.However,the radiograph before and after treatment in the same cases did not differ significantly.Conclusions MRI was earlier and more comprehensive in showing limbs bone marrow abnormality than radiogram in acute leukemia children with chief complaint of osteoarticular pains.MRI might be one of indicators in following up therapeutic effect for AL children with osteoarticular disorder.

Objective To investigate MRI manifestations of lumbar and proximal femoral bone marrow changes before and after recombinant human granulocyte colony stimulating factor (rhG-CSF) was subcutaneous injected for healthy adults.Methods Twenty healthy blood stem cell donors without hematologic disease were enrolled in this study. All of them underwent lumbar sagittal and proximal femur coronal MRI examination with spin echo T1 WI and fat-suppressed T2WI.The first examination were performed before subcutaneous injection of rhG-CSF for comparison. In 4-7 days and 30-60 days after injection, the other two examinations were performed. The signal changes of lumbar and proximal femoral bone marrow were investigated by reading pictures and calculating the contrasted noise ratio (CNR).ResultsBefore rhG-CSF injection, all patients presented normal signal intensity of hone marrow. In 4-7 days after injection, all the 20 cases presented homogeneous signal decrease in lumbar vertebral bodys on T1 WI, accompanied by reduced fatty signal. In proximal femur, patchy or stripped hypointensity areas were found in intertrochanteric and subtrochanteric areas on T1 WI. On fat-suppressed T2 WI images, the signal of lumbar and proximal femoral bone marrow changed to equal or slightly-high signal intensity. In all cases,abnormal signal areas presented in lumbar and proximal femoral bone marrow occurred simultaneously in the same case.In the 10 cases received the third MRI during 30-60 days after rhG-CSF injection, signal intensity of lumbar bone marrow turned to normal in all sequence, but abnormal signal intensity areas were still existed and extended to distal part in femoral bone marrow, which appeared as symmetric stripped or patchy equal or slightly-low signal intensity on T1 WI and equal or slightly-high signal intensity on T2 WI. The CNR of lumbar bone marrow to subcutaneous fat before rhG-CSF injection, in 4-7 days and 30-60 days after rhG-CSF injection were 114. 11 ± 15. 11,71.04 ± 12. 25 and 91.64 ± 1 I. 68, respectively. Significant difference was found between before rhG-CSF injection and 4-7 days after injection ( P ＜ 0. 05 ) , but no significant difference between the others( P ＞ 0. 05 ). Conclusion After injection of rhG-CSF, the short-term changes of hematopoietic cells and fat content in bone marrow can be displayed on MRI, which provided non-invasive information for bone marrow transplantation.

Objective To investigate the value of MRI and~1H-MRS in diagnosis of early stage of diabetic encephalopathy by detecting regional metabolite in cynomolgus diabetes models. Methods Five pathogen-free male adolescent cynomolgus were made type 1 diabetes mellitus models (T1DM) by intravenous injection of streptozotocin (STZ) (100 mg/kg), and the reliability and stability of the modes were assessed with long term follow-up of blood glucose and intravenous glucose tolerance tests. MRI and ~1H-MRS were performed to evaluate the volume, signal intensity and metabolic ratios of NAA/Cr, mI/Cr and Cho/Cr at hippocampus, lateral temporal lobe and occipital lobe 3 years after model establishment. Cortisol in serum was detected with immunoradiometric assay. In addition, 5 normal adult cynomolgus monkeys were selected in the control group and accepted the same examination above. Results ①Intravenous administration of STZ could made stable T1DM monkey model. ②Only mI/Cr ratio increased at hippocampus of diabetic monkeys compared to the control group (P<0.05). ③There was no statistical difference of cortisol in serum between the diabetic group and the control group (P＞0.05). Conclusion ~1H-MRS may detect the metabolic changes of the hippocampus in STZ-induced diabetic adolescent cynomolgus monkeys and may contributes to the early diagnosis of diabetic encephalopathy.

Objective T9 provide candidate molecules for developing recombinant anti-idiotypic antibody (anti-Id) vaccine of gastric carcinoma by selection of recombinant anti-Id to monoclonal antibody ( McAb) MGb1 directed against the cancer with phage display technique.Methods Balb/c mice were immunized with MGb1 and the mRNA was isolated from the spleens of the immunized mice. The VL and VH cDNAs of the antibody were amplified separately by RT-PCR and assembled into ScFv DNAs with a linker DNA. The ScFv DNAs were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13KO7 helper phage to yield recombinant phage antibody ScFv library. After four rounds of biopanning to the library with MGb1, the MGb1-positive clones were selected from the enriched phages by ELISA. The types of the anti-Id ScFv displayed on the selected phage clones were preliminarily identified by competition ELISA. Results The VL and VH cDNAs was about 320 bp and 340 bp, respectively. The ScFv DNA were about 750 bp. After four rounds panning to the phage antibody ScFv library with MGb1, 18 MGb1-positive phage clones displayed anti-Id ScFv were selected from 50 pre-selected phage clones, among which 4 clones displayed β or γ type anti-Id ScFv. Conclusion The phagedisplayed anti-Id ScFvs to McAb MGb1 are successfully selected by recombinant phage antibody technique, which might lay a foundation for screening the anti-Id ScFv possessing the characteristics of inducing anti-gastric carcinoma immunity.

0.05). Conclusion:Certain concentration of TG can inhibit the apoptosis of Schwann’s cell and the expression of major histocompatibility antigen of cold preserved sciatic nerve in rats,and decrease rejection after nerve allograft.