Excitotoxicity refers to a process of neuronal death caused by excessive or prolonged activation of receptors for the excitatory amino acids, which is related to the overload of intracellular calcium ([Ca2+]i) and mitochondrial depolarization. The well accepted hypothesis that Ca2+ plays a central role in neurotoxicity, and it mediated excitotoxicity is deeply involved in both acute and chronic neurodegeneration suggests that inhibitors of Ca2+ transduction, such as NMDA antagonists, might block the pathological process at an early stage and provide more effective protections.

Objective To construct markless gene deletion mutant at the clpP loci on the chromosome of Streptococcus mutans(S.mutans).Methods ASp resistance gene was amplified by PCR,to construct the Sp resistance cassette where the Sp resistance gene was flanked with two loxP site.After the clpP gene was cloned into the pGEM-T-Easy TA cloning vector,it was digested and linked with the Sp resistance cassette,yielding homologous recombination vector pIB △ clpP-Sp.The vector was linearized and used for the transformation of S.mutans UA159,with transformants selected on TPY plates containing Sp.The selected strain was transformed with the thermosensitive plasmid pCrePA to excise the Sp resistance gene.The pCre-PA was then easily eliminated at nonpermissive temperature,resulting in a markless mutant strain carrying a deletion at the clpP loci,which was verified by PCR and DNA sequencing.Results The result of the PCR analysis and DNA sequencing indicated that a part of the clpP gene was deleted.There was a loxP at this loci without the Sp resistance gene.Conclusion The markless clpP-deletion mutant of S.mutans was constructed successfully,which laid a foundation for further study of its biological function and its influence on the cariogenicity of S.mutans.

Objective To explore the oxidative stress pathogenesis of Parkinson's disease(PD) induced by paraquat in substantia nigra of mice. Methods The model of PD was established by oral administration of paraquat to mice.The spectrophotometry was used to determine the activities of superoxide dismutase(SOD) and glutathione peroxidase(GSH-PX) and the content of malondialdehyde(MDA) in substantia nigra.At the same time,number of tyrosine hydroxylase(TH) positive neurons in substantia nigra of mice was estimated by immunohistochemistry. Results The activities of SOD and GSH-PX were significantly decreased,and the content of MDA was increased in paraquat-treated mice compared to that of mice treated by saline taken orally(P

Objective:To explore the status of STAT3 phosphorylation in myeloid-derived suppressor cells (MDSCs) of breast cancer and its function in the immunosuppressive effect of MDSCs on proliferation and cytokine secretion of T cells. Methods:CCD33+cells were isolated from healthy umbilical cord, blood-derived, peripheral blood mononuclear cells and were co-cultured with breast cancer cell line MDA-MB-231 in vitro using Transwell plates to induce MDSCs. The untreated CD33+cells were used as con-trols. Idoxuridine (IDO) suppressor expression and STAT3 phosphorylation were examined using Western blot assay. The proliferation and cytokine secretion of T cells, which were co-cultured with MDSCs, were determined by methyl thiazol tetrazolium assay and en-zyme-linked immunosorbent assay. 1-MT and JSI-124 were used to investigate the function of IDO and pSTAT3 in MDSC-mediated T cell immunosuppression. Results:The protein levels of IDO and pSTAT3 in MDSCs were significantly upregulated. MDSCs obviously suppressed T-cell proliferation, which was reversed by 1-MT or JSI-124 (P<0.05). MDSCs could promote TGF-βand IL-10 secretions, but could also remarkably inhibit IFN-γsecretion (P<0.05). After incubation with 1-MT or JSI-124, the increase in TGF-βand IL-10, as well as the decrease in IFN-γ, was significantly reversed. Conclusion:The upregulated pSTAT3 induced the IDO increase in MDSCs. JSI-124 can block MDSC-mediated immunosuppressive effect on T cells in breast cancer.

BACKGROUND:Simple pedicle screw fixation for thoracolumbar fractures has better outcomes, but there are some deficiencies, such as poor applicability for severe compression or burst fractures, strong vertebral pain, easy to cause vertebral wound denervation and paraspinal muscle injury, and slow recovery. OBJECTIVE:To investigate the clinical effects of pedicle screw fixation combined with artificial bone graft for the treatment of thoracolumbar fractures. METHODS:A total of 126 patients with thoracolumbar vertebral compression fractures, who had undergone pedicle screw fixation without bone graft (control group,n=62) and with bone graft (test group,n=64) were enroled. The fracture healing, anterior vertebral height ratio, sagittal Cobb angle, and loss rate of vertebral height after 6 months were observed by X-ray in the two groups. RESULTS AND CONCLUSION:Al patients were folowed up, and had complete fracture healing after 12-16 months. The anterior vertebral height and Cobb angle were both improved in the two groups at 1 week after operation (P < 0.01), but there was no difference between the two groups (P > 0.05). New bone formation was observed in the test group at 6 months after operation, and patients were pain-free; but the speed of bone formation was slower in the control group, and patients stil suffered from painful thoracolumbar fractures. There was no difference in the loss of anterior vertebral height and Cobb angle between the two groups (P> 0.05). These findings indicate that pedicle screw fixation combined with artificial bone graft lead to a better recovery in thoracolumbar fractures.

Objective To evaluate the different expression of the serum proteome of patient with severe acute pancreatitis (SAP) before and after treatment,and search for the protein that can predict SAP improvement.Methods SELDI-TOF-MS was used to analyze the expression of serum protein spectrum of 20 SAP patients before treatment and 7 days after treatment,and make the APACHE Ⅱ score at the same time.Results The APACHE Ⅱ score was 10.70 ± 3.47 in patients with SAP 7 days after treatment,which were significantly lower than that before treatment ( 13.00 ± 2.21,P ＜0.05 ).One hundred thirty-two spectral peak clusters were detected before and after treatment,there were 27 proteins that had significantly different signal intensities had been detected from 2000 Da to 50000 Da (P ＜ 0.05 ).The peak cluster at 47 000 Dawas significantly down-regulated after SAP attenuation.While the peak clusters at 1l700 Da and 15900 Dawere significantly up-regulated after treatment.Conclusions Serum analysis with SELDI-TOF MS can detect the different expression of the SAP serum proteomics before and after treatment,the increased expression of the protein with molecular weight of 11500 Da and 15900 Da and the decreased expression of 4700 Da may be asignal of improvement of SAP.

In this study, five rhesus macaques were inoculated intravenously with SIVmac251 to establish a model of simian autoimmune deficiency syndrome (SAIDS). Peripheral blood samples were collected at different time points to monitor changes in the total T cell number and T lymphocyte subset. Plasma viral loads, cytokine expression levels and anti-SIV antibody levels were also assayed to acquire certain basic indexes to evaluate disease progression in the rhesus macaque SAIDS model. During the acute stage of infection, plasma viral loads reached a peak at week 1 post-inoculation and lasted for approximately 3 to 44 weeks. The CD3+ CD4+ T lymphocyte count in peripheral blood also transitorily decreased. During the same period, the level of interferon-gamma show an increasing trend, whereas IL-12 levels decreased; IL-2, IL-4, IL-10 and TNF-alpha were maintained at normal levels or could not be detected. During the asymptomatic and ARC phases, plasma viral loads persisted above 10(4) RNA copies/mL and either increased or declined during the later stages of disease; CD3+ CD4+ counts showed a steadily declining trend and the ratio of CD4 to CD8 decreased during late-stage disease. Moreover, antibodies against viral proteins were detected in the plasma and showed a significant increasing trend, while there were no apparently changes in the levels of IFN-gamma, IL-12, IL-2, IL-4, IL-10 and TNF-alpha. In conclusion, the characteristics of the SIV animal models in our study are similar to those of patients with AIDS. Therefore, the rhesus macaque SIVmac251 infection models can be applied for further studies into AIDS.
Animals ; Antibodies, Viral ; blood ; CD4 Lymphocyte Count ; CD4-Positive T-Lymphocytes ; virology ; Cytokines ; genetics ; immunology ; Disease Models, Animal ; HIV Infections ; genetics ; immunology ; virology ; HIV-1 ; physiology ; Humans ; Macaca mulatta ; Male ; Simian Acquired Immunodeficiency Syndrome ; genetics ; immunology ; virology ; Simian Immunodeficiency Virus ; physiology ; Viral Load

In order to investigate the features of multidetector CT (MDCT) and magnetic resonance imaging (MRI) as well as the corresponding pathogic basis of solitary fibrous tumor (SFT) in the pelvis, we collected the clinical data of 13 patients with pathologically confirmed SFT in pelvis, and retrospectively reviewed the MDCT and MRI appearances. Of these enrolled patients, 6 received MDCT scans, 5 underwent MRI scans, and 2 underwent both MDCT and MRI examinations. Shown on the MDCT and MRI, the maximum diameters of the masses ranged from 4.0 to 25.2 cm (averaged 11.8 cm). Six masses were lobulated, and seven were round or oval. In addition, all masses were well-defined and displaced the adjacent structures to some degrees. On the computed tomography, all masses were of isodensity on unenhanced scans in general, among which five masses were demonstrated with hypodense areas. On the MRI T1-weighted image, all lesions were isointense, of which patchy hypointense areas were detected in 3 cases and radial hypointense areas were in 3 cases, and the other one was presented with homogenous intensity. On T2-weighted images, most of the lesions were mixed hyperintense, of which 3 cases were of heterogenous hyperintesity, radial hypointense areas were detected in 3 patients, and the other one was homogenously intense. On enhanced computed tomography and MRI, large supplying vessels were found in 4 cases; 12 cases showed moderate to conspicuous enhancement, and the other one was presented with mild homogenous enhancement. Of the patients with moderate to conspicuous enhancement, patchy areas of non-enhancement were detected in 7 cases, radial areas of progressive enhancement were detected in 3 cases, and the remained 2 cases showed homogenous enhancement. On pathology, the radial area presented as progressive enhancement was fibrosis. During the follow-ups after surgery, 2 patients had local recurrence and 1 had metastasis to liver. In conclusion, the SFT in the pelvis are commonly presented as a large solid, well-defined and hypervascular mass with necrosis or cystic changes at some extents together with the displacement of adjacent structures. The radial area with hypointensity on T2-weighted image and with progressive enhancement on enhanced magnetic resonance imaging is an important feature of SFT, which can be helpful for the diagnosis of this mass.
Humans ; Magnetic Resonance Imaging ; Neoplasm Recurrence, Local ; Pelvis ; pathology ; Retrospective Studies ; Solitary Fibrous Tumors ; diagnosis ; pathology ; Tomography, X-Ray Computed

Objective To investigate whether the vohage-gated chloride channel CLC-2 gene— CLCN2 is associated with idiopathic generalized tonie-clonic seizures(often called a grand mal seizure, GME)of Jinuo people and Han people from Yunnan province.Methods Three regions,including Intron 2, Exon 5 and Exon 19(Intron 18),of CLCN2 were selected to conduct sequence analysis.The case-control study design was used to detect association between gene polymorphism and idiopathic generalized tonic- clonic seizures of Jinuo people and Han people from Yunnan province.Results No previously reported susceptible mutations were found in Intron 2,Exon 5 and Exon 19 in Jinuo people and Han people from Yunnan province.However we found a single nucleotide polymorphism(SNP)at site 146 of Intron 18. Case-control study were carried out,using this SNP.Distribution of the 3 genotypes(TT,TC,CC)has a significant difference between the IGTCS patients of Han people and the normal controls of Han people(9, 3,29 cases and 22,9,26,respectively,x~2=16.079,P

BACKGROUND:A large number of studies have confirmed that tissue-engineered stem cel therapy is feasible to repair peripheral nerve injury, but the repair mechanism is unclear.
OBJECTIVE:To observe the differentiation and homing of bone marrow mesechnymal stem cel s under local nerve microenvironment by exploring the migration and effect of bone marrow mesenchymal stem cel s in the repair of damaged nerve.
METHODS:Male SD rats, aged 8 weeks, were selected to establish segmental nerve injury models by freezing the sciatic nerve. Thirty-six model rats were randomized into three groups (n=12):frozen nerve injury group, cel injection into the nerve group, cel injection around the nerve group. Before modeling and at 4, 8, 12 weeks after cel implantation, the sciatic nerve function index was measured. Electrophysiological test, contractility recovery rate, wet weight recovery rate of the triceps surae were detected and Masson staining was performed;toluidine blue staining of the distal nerve injury and immunofluorescence staining of the damaged nerve were performed.
RESULTS AND CONCLUSION:At 4, 8, 12 weeks after cel implantation, the sciatic nerve function index was ranked as fol ows:frozen nerve injury group