Objective:To investigate the role of CD8 + T cells in lethal Plasmodium yoelii 17XL ( Py 17XL) infection. Methods:BALB/c mice and C57BL/6 mice were infected with Py 17XL-infected red blood cells (1×10 6 cells/0.1 ml) through intraperitoneal injection to establish the mouse models of Py 17XL infection. Parasitemia (the percentage of erythrocytes infected with Py 17XL) and the survival rates of the mice was observed dynamically. Flow cytometry was used to detect the number of effector T cells (T EFF) and central memory T cells (T CM) of CD8 + T cell subpopulations, the expression of IFN-γ and granzyme B (GB) levels, and the expression of surface chemokine receptors CXCR3, CXCR6 and CX3CR1. FTY720 blocking experiment was conducted on Py 17XL-infected C57BL/6 mice to analyze the impact of CD8 + T cell migration on Py 17XL infection. Results:The parasitemia of BALB/c mice increased rapidly 5 d after infection and reached the peak on 8 d [(79.57±3.82)%]. Besides, the parasitemia was higher in BALB/c mice than in C57BL/6 mice 5-8 d after infection ( P<0.000 1). All BALB/c mice died on 9 d. The parasitemia of C57BL/6 mice reached the peak on 14 d [(48.19±3.19)%] and then decreased to 0 on 26 d. There was statistically significant difference in the survival rate between the two groups ( P<0.000 1). Flow cytometry results showed that compared with the BALB/c mice, the absolute number of CD8 + T cells in spleen and liver tissues and the number of CD8 + T EFF and CD8 + T CM cells in spleen and lymph nodes of C57BL/6 mice increased significantly ( P<0.05). Compared with the BALB/c mice, the levels of GB, IFN-γ and chemokines expressed by CD8 + T cells in spleen and liver tissues of C57BL/6 mice increased significantly ( P<0.05). The FTY720 blocking experiment showed that the survival rate, the absolute number of CD8 + T cells in liver and spleen, and the number of CD8 + CXCR3 + T cells decreased significantly in the experimental group ( P<0.05). Conclusions:CD8 + T EFF and CD8 + T CM cells contribute to resistance against Py 17XL infection by secreting GB and IFN-γ. The chemokine receptor CXCR3 plays an important role in mediating the chemotaxis of CD8 + T cells to spleen and liver.

Rheumatoid arthritis is a chronic, systemic autoimmune disease predominantly based on joint lesions with an extremely high disability and deformity rate. Several drugs have been used for the treatment of rheumatoid arthritis, but their use is limited by suboptimal bioavailability, serious adverse effects, and nonnegligible first-pass effects. In contrast, transdermal drug delivery systems (TDDSs) can avoid these drawbacks and improve patient compliance, making them a promising option for the treatment of rheumatoid arthritis (RA). Of course, TDDSs also face unique challenges, as the physiological barrier of the skin makes drug delivery somewhat limited. To overcome this barrier and maximize drug delivery efficiency, TDDSs have evolved in terms of the principle of transdermal facilitation and transdermal facilitation technology, and different generations of TDDSs have been derived, which have significantly improved transdermal efficiency and even achieved individualized controlled drug delivery. In this review, we summarize the different generations of transdermal drug delivery systems, the corresponding transdermal strategies, and their applications in the treatment of RA.

Objective:To investigate the distribution of 99Tc m-methylene diphosphonate (MDP) at different stages of bone injury repair. Methods:A total of 30 rabbit models of femur injury were established by the method of electric drill and perforation of femur. According to the different stages of bone injury repair (at 1, 2 and 3 week), rabbits were divided into group A, B and C ( n=10 each group). Femoral SPECT/CT imaging was performed on the last day of different stages of bone injury repair to obtain radioactivity counts in the region of interest (ROI) on the test side and control side and to calculate target/background ratio (T/B). The light intensity of 3 groups was analyzed by phosphor screen imaging and the distribution of 99Tc m-MDP in bone cells was observed by autoradiography. One-way analysis of variance and paired t test were used to analyze the data. Results:The T/B values of group A, B and C were 1.16±0.14, 1.39±0.23 and 1.18±0.10, respectively ( F=5.83, P<0.01). There were significant differences of the maximum radiation count between the test side (50.00±12.45, 59.50±12.83 and 55.10±9.26) and the control side (43.20±9.57, 50.00±12.30 and 44.30± 6.50) in group A, B and C ( t values: 3.24, 2.28 and 5.77, all P<0.05). There were significant differences in the light intensity of bone specimens in group A, B and C by phosphor screen imaging (37 324.67±6 481.50, 60 950.33±9 781.72 and 43 905.00±4 957.92; F=8.25, P=0.02). 99Tc m-MDP were deposited in both intracellular and extracellular during different stages of bone repair in osteocytes and osteoblasts under autoradiography. Conclusion:At different stages of bone injury repair, the concentration of 99Tc m-MDP is significantly distributed, suggesting that there are other ways of concentration mechanism of 99Tc m-MDP in bone tissue besides the chemical adsorption with hydroxyapatite.

Since December 2019, novel coronavirus pneumonia (NCP) has been reported in Wuhan, Hubei Province, and spreads rapidly to all through Hubei Province and even to the whole country. The virus is 2019 novel coronavirus (2019-nCoV), never been seen previously in human, but all the population is generally susceptible. The virus spreads through many ways and is highly infectious, which brings great difficulties to the prevention and control of NCP. Based on the needs of orthopedic trauma patients for emergency surgery and review of the latest NCP diagnosis and treatment strategy and the latest principles and principles of evidence-based medicine in traumatic orthopedics, the authors put forward this expert consensus to systematically standardize the clinical pathway and protective measures of emergency surgery for orthopedic trauma patients during prevention and control of NCP and provide reference for the emergency surgical treatment of orthopedic trauma patients in hospitals at all levels.

BACKGROUND:Previous studies have verified that mesenchymal stem cells could be transplanted into inflammatory bowel mucosa to repair inflammatory bowel tissue. OBJECTIVE:To observe the differential gene expression in large intestine before and after mesenchymal stem celltransplantation in repair of inflammatory bowel tissue of rats using microarray technology, and to primarily discover the main genes during mesenchymal stem celltransplantation, differentiation, and reparation in inflammatory colorectal tissue region. METHODS:Healthy Sprague-Dawley rats were randomly divided into two groups. Experimental rat models of inflammatory bowel disease were established using trinitrobenzene sulfonic acid via enema. At 24 hours after model establishment, green fluorescent protein-labeled mesenchymal stem cells were infused via the caudal vein. The control group was treated with physiological saline by enema, instead of trinitrobenzene sulfonic acid. At 28 days, large intestine was obtained from the experimental group and control group. Differential y expressed genes were screened in the experimental and control groups using microarray technique. RESULTS AND CONCLUSION:The microarray analysis results showed that there were 388 differential genes in the control and experimental groups (P<0.05, FC>2), in which 191 were up-expressed, and 197 were down-expressed. Al of these genes were mainly involved in inflammatory reaction, immune reaction and celldifferentiation. In the top 10 up-regulation and down-regulation differential genes (total y 20 genes), 3 genes were involved in inflammation, 3 genes were involved in immune reaction, and 2 genes were related to stem celldifferentiation. In the 388 genes, 33 were related to signaling pathways (P<0.05), 6 related to inflammation, 8 related to immunity, and 5 related to stem celldifferentiation. Results suggested that the main genes involved in mesenchymal stem cells in repair of inflammatory bowel tissue were primarily screened using gene expression microarray technique.

BACKGROUND:β-catenin is the most critical signaling molecule in the Wnt/β-catenin signaling pathway, which is involved in the regulation of cellproliferation, differentiation and tissue self-healing balance.
OBJECTIVE:To construct a stableβ-catenin over-expression lentivirus-mediated vector and to transfect mesenchymal stem cells line for investigating its effects on proliferation and migration of mesenchymal stem cells.
METHODS:Over-expression vector, PLV-EF1A-catenin-RFP, was constructed and transfected the 293T cellto infect mesenchymal stem cells, and positive cells were selected with puromycin. The up-regulated efficiency of targetingβ-catenin gene at mRNA level was detected by real-time quantitative PCR, the effect on proliferation of mesenchmal stem cellwas assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and growth curve, and the migration ability was detected by Transwel motility assay.
RESULTS AND CONCLUSION:The lentiviral vector targetingβ-catenin gene was constructed successful y, and a stable mesenchymal stem cellline that up-regulatedβ-catenin was established. Real-time quantitative PCR results showed that the expression ofβ-catenin gene was efficiently up-regulated by infecting PLV-EF1A-catenin-RFP (P<0.05). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and growth curve showed that celldoubling time was shortened after infected with pLV-EF1A-catenin-RFP (P<0.05), indicating that the over-expression of theβ-catenin gene successful y increased the proliferative capability of mesenchymal stem cells. The Transwel assay also showed similar increasing results on the migration ability (P<0.01). The lenvivirus-mediated over-expression of theβ-catenin gene can be used to increase the proliferation and migration abilities of the mesenchymal stem cells.

Objective To construct a lentiviral vector over-expressing β-catenin gene by multisite Gateway technology and confirm its effect.Methods By using multisite Gateway clone technique,the entry clone of pDown-Ctnnb1 was constructed using BP recombination reaction.Then,LR recombination reaction was performed among pUp-EF1A,pDown-Ctnnb1,pTail-IRES/DsRed-Express2 and pLV.Des3d.P/puro to generate an expression clone of pLV.EX3d.P/puro-EF1A＞Ctnnb1 ＞IRES/DsRed-Express2.In each step,PCR and sequencing analysis were used to verify the constructions.When it was verified that plasmids were transfected into 293T cells,PT-PCR was performed to determine the mRNA level of β-catenin gene.Results Both PCR and sequencing analysis revealed that β-catenin over-expression gene was inserted into the target site and the insertion sequence was perfectly corrected.The RT-PCR results showed that the expression of β-catenin gene was significantly upregulated.Conclusion The lenvivirus-mediate β-catenin over-expression gene was successfully constructed..

To investigate the role of Toll like receptor (TLR) in the activation of dendritic cells (DC) during early Plasmodium yoelii infection of the lethal strain 17XL (P.y 17XL), susceptible BALB/c and resistant DBA/2 mice were infected by i.p.injection of the P.y l7XL-parasitized erythrocytes, and the parasitemia of individua1 mice was monitored by the microscopic examination of blood smear stained with Giemsa.Mice from norma1 and infected groups were sacrificed on 0,3 and 5 days post-infection to collect their spleen cells.And the expressions of TLR-9 and TLR-4 on the cell surface of DCs in spenonocytes of these two strains of mice were assayed by applying flow cytometry to quantitatively analyze the percentages of CD11c+TLR9+ DCs and CD11c+TLR4+ DCs. It was found that the population of CD11c+DCs expressing TLR9 was significantly increased on day 3 and peaked on 5 p.i. in BALB/c (P<0.01) and DBA/2 mice(P<0.01). However, there was no statistical significance between these two strains of mice. Meanwhile, there was no change on the population of CD11c+ DCs expressing TLR4 in BALB/c and DBA/2 mice. These results indicate that TLR9 may contribute to the DC activation during early stages of P.y17XL infection.

Objective To investigate the development and dynamic changes of host immune response in DBA/2 mice infected with Plasmodium yoelii 17XL. Methods Female DBA/2 mice were infected by intraperitoneal ( i. p. ) injection of 106 P. yoelii 17XL parasitized erythrocytes ( PRBC). Levels of IL-12, IFN-γ, IL-4, IL-10 and P. yoelii 17XL-specific antibody in sera were measured by ELISA. Concentrations of NO in cell supernatants were measured by the Griess reaction. Parasitemia,percentage of mononuclear-macrophages of individual mice were monitored daily, and phagocytosis of mononuclear macrophages was also observed. Results Primary parasitemia in vein blood was developed on day 3 postinfection, which peaked with a level of 46. 9% on day 9. Most mice cleared the infection and survived by day 20 postinfection. From day 6 to day 16, the phagocytosis of PRBC by rodent macrophages was observed on the blood smear. Infected mice had a continuously increased level of IL-12 in serum from day 1 postinfection. Accordingly, high level of IFN-γ was also detected in sera from day 1 postinfection,which peaked on day 6. Infected mice produced higher level of IL-4 and IL-10 in serum on day 6 postinfection, which peaked on day 9 and day 15 postinfection respectively. In addition, splenocytes from infected mice produced significantly higher level of NO on day 6 and 20 postinfection. Level of P. yoelii 17XL-specific IgG was determined in the sera of infected mice with a steadily increased trend after infection, which peaked on day 70 postinfection. Conclusions Effective polarizing of Thl cells is significant in inhibition of parasitemia and eventual clearance of the Plasmodium parasites. Activated mononuclear-macrophages play a key role in inhibiting parasitemia in the early phase of infection with P. yoelii 17XL.

Objective To observe the expression levels of CD174, cyclin D1 and cyclin E in gastrointestinal tumor tissues, analyze the correlation among CD174, cyclin D1 and cyclin E, and evaluate the expression level of CD174 for diagnosis and prognosis of gastrointestinal tumors.Methods Flow cytometry was used to determine the expression of CD174, cyclin D1 and cyclin E on surface of the cells which were collected from the tumor tissues and distant part beside the same tumor and suspended. The expression and topography of CD174 in gastrointestinal tissue were investigated with immunohistochemical staining.Results The expression of CD174 in tumor tissues was obviously lower than that in distal noncancerous tissues (P