BACKGROUNDAscorbic acid (AA) represents one of the most important enzyme co-factors, antioxidants and neuromodulators and plays an important role in the cerebral system. Increasing evidence has suggested that AA could treat certain kinds of vertigo diseases such as Meniere's disease. To elucidate the neurochemical functions associated with AA in vertigo, the change of extracellular AA in the brain cortex following caloric vestibular stimulation (CVS) was evaluated.

METHODSAn on-line electrochemical detection was coupled with in vivo microdialysis to continuously monitor the change of extracellular AA in the primary somatosensory (SI) area of guinea pigs following a caloric vestibular stimulation. Sixteen guinea pigs were divided into three groups, i.e., experimental group with irrigation of the ear canal with ice water (0 degrees C) (n = 8), and two control groups, one with irrigation of the ear canal with warm water (38 degrees C) (n = 4) and the other with irrigation of the auricle with ice water (n = 4).

RESULTSIn the experimental group, the ice water irrigation of the left external ear canal induced a horizontal nystagmus towards the right side lasting about 45 seconds. No nystagmus was induced by warm water irrigation of the external ear canal or by ice water irrigation of the auricle. The extracellular AA concentration significantly increased following the ice water vestibular stimulation, reaching a maximum of (130 +/- 20)% (n = 8) of the basal dialysate level (2.61 +/- 0.92) micromol/L (n = 8), lasting at least for an hour. AA level did not change distinctly after the irrigation of the left external ear canal with warm water or the irrigation of the auricle with ice water.

CONCLUSIONSThe concentration of extracellular AA in the brain cortex of the SI area increased following the ice water vestibular stimulation. This demonstration may be useful for the investigation of the neurochemical processes associated with AA in the process of vertigo.

Animals ; Ascorbic Acid ; analysis ; Cerebral Cortex ; metabolism ; Electrochemistry ; methods ; Extracellular Space ; metabolism ; Guinea Pigs ; Ice ; Male ; Microdialysis ; methods ; Physical Stimulation ; methods ; Vestibule, Labyrinth ; physiopathology

OBJECTIVETo explore the killing effect of the mutant herpes simplex virus thymidine kinase (HSV-sr39tk) and its wild-type (HSV-tk) mediated by lentiviral vector on T lymphocytes in vitro and compare T cell survival rate after GCV or ACV treatment.

METHODSThe three-plasmid lentiviral vector system including packaging plasmid DeltaNRF, envelope plasmid VSV-G and vector plasmid (pTK151 + HSV-sr39tk or pTK151 + HSV-tk) were cotransfected into human embryonic kidney 293T cells using modified calcium phosphate precipitation methods. The packaged virus was harvested 72 h later. The survival of T cells expressing HSV-sr39tk or HSV-tk was measured by MTT assay after 4 day-culture against a gradient of GCV or ACV concentrations.

RESULTSThe three plasmids were effectively cotransfected and a high titre of lentivirus was obtained (2 x 10(6) IU/ml). 39tk(+) T cell survival rates declined promptly when the prodrug GCV/ACV concentrations increased from 0 micromol/L to 10 micromol/L. The T cell survival rates in GCV group declined from (96.04 +/- 3.23)% to (36.76 +/- 4.38)% while in ACV group from (97.31 +/- 4.61)% to (43.75 +/- 8.99)%. However, when GCV/ACV concentrations were more than 10 micromol/L, further decline of 39tk(+) T cell survival rates became unobvious. The growth rate of 39tk(+) T cell exposed to GCV or ACV was obviously lower than that in un-transfected T cells (P < 0.05). Tk(+) T cells were sensitive to GCV (P < 0.05), but not to ACV (P > 0.05). There was a significant difference in killing effects between 39tk(+) T cell + GCV group and tk(+) T cell + GCV group (P < 0.05).

CONCLUSIONThe lentiviral vectors containing HSV-sr39tk gene could infect T lymphocytes effectively and stably without affecting the proliferation of the transduced cell. In contrast to HSV-tk gene, T cells infected HSV-sr39tk were more sensitive not only to GCV but also to ACV.

Acyclovir ; pharmacology ; Animals ; Cell Survival ; drug effects ; Cells, Cultured ; Ganciclovir ; pharmacology ; Genetic Vectors ; Lentivirus ; genetics ; Mice ; Mice, Inbred C57BL ; Plasmids ; genetics ; T-Lymphocytes ; cytology ; drug effects ; Thymidine Kinase ; genetics ; Transfection

OBJECTIVETo establish strategies for preventing graft versus host disease (GVHD) and reducing treatment associated morbidity while preserving graft versus leukemia (GVL) effect in nonmyeloablative allogeneic bone marrow transplantation (allo-BMT), with or without donor lymphocyte infusion (DLI) after BMT.

METHODS3 x 10(7) bone marrow cells mixed with 1 x 10(7) spleen cells from the same BALB/c mouse were transplanted into the nonablative irradiated inbred 615 mouse which received a single subcutaneous injection of 1 x 10(6) L615 leukemia cells three days before. The experiments were designed as follows (ten mice in each group): myeloablative BMT control group (group A), nonmyeloablative conditioning without BMT group (group B), nonmyeloablative BMT group (group C), and nonmyeloablative BMT + DLI group (group D). GVL effects were assessed by survival time, white blood cell count and L615 cells in peripheral blood and histologic changes. GVHD was assessed by signs of weight loss, ruffled fur, diarrhea and histologic changes of skin, liver and small intestines. Chimerism was detected by cytogenetic analysis and PCR technique.

RESULTSThe survival time of group A, B, C and D was (20.3 +/- 13.4), (15.9 +/- 1.1), (21.6 +/- 1.7) and (37.8 +/- 2.0) days, respectively, being no significant difference between group A and group C (P > 0.05). The survival time of group C was longer than that of group B (P < 0.01). And among group B, C and D, group D had the longest survival time (P < 0.01). GVHD signs and histologic changes were observed in 60% of control group mice at + 14 day, but none of group C and group D. 40% of mice in group A died of treatment associated morbidity within two weeks, but none in group C and group D. Allogeneic chimerism was kept in group A, but excluded gradually in group C.

CONCLUSIONGVL effect seems preserved in nonmyeloablative BMT mice, but weaker than that in myeloablative BMT mice. GVL effect seems to be enhanced by DLI after nonmyeloablative BMT. GVHD and transplantation associated morbidity seems to be reduced in nonmyeloablative BMT.

Animals ; Bone Marrow Transplantation ; immunology ; methods ; Combined Modality Therapy ; Female ; Graft vs Host Disease ; prevention & control ; Graft vs Leukemia Effect ; Leukemia, Experimental ; therapy ; Leukemia, Lymphoid ; therapy ; Lymphocyte Transfusion ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Inbred Strains ; Transplantation Conditioning ; methods ; Transplantation, Heterologous

OBJECTIVETo construct a three plasmids lentiviral vector containing canine coagulation factor IX (cFIX) gene with ubiquinone promoter (PUB) and observe the expression of cFIX gene.

METHODSLentivirus was generated by transient three-plasmid transfection, namely, the VSV-G envelope expression cassette, the delta NRF packaging plasmid and the PTK 164 plasmid. Viral particles were used to infect the target cell, third passage mesenchymal stem cells (MSCs) and 293T cell respectively at MOI 3: 1. The cFIX activity was detected in cultured cells with one-stage clotting assay.

RESULTSThe MSCs were obtained in vitro. The lentivirus infected MSCs and 293T cells all expressed the active factor IX with the activity of (26.30 +/- 2.10)% and (19.70 +/- 1.53)%, respectively, which are significantly higher than that of control (1.00 +/- 0.05)%.

CONCLUSIONSThe lentiviral vector of three plasmids with ubiquinone promoter (PUB) was constructed and can transfect the MSCs and 293T cells.

Animals ; Bone Marrow Cells ; metabolism ; Cells, Cultured ; Dogs ; Factor IX ; genetics ; metabolism ; Genetic Vectors ; Hemophilia B ; genetics ; metabolism ; Humans ; Lentivirus ; genetics ; Plasmids ; genetics ; Transfection

The study was purposed to prepare the recombinant lentiviral vector pTK161 and pTK162 carrying B-domain-deleted canine factor (BDDcFVIII) gene, and to investigate whether the canine FVIII (cVIII) can be expressed in vitro. The BDDcFVIII gene was ligated behind PUB and 2OH1 promotors to create lentiviral vectors pTK161 and pTK162. Meantime lentiviral vectors pTK161' and pTK161' were produced by cloning a green fluorescent protein (GFP) into pTK151 and pTK152, which was driven by PUB and 2OH1 promotors respectively. Vector supernatant were prepared by using transfer calcium phosphate mediated-cotransfection of 293T cells. The virus vector, DeltaNRF packaging-plasmid, and VSV-G envelope-plasmid was assayed by titers and cFVIII activity in cell culture supernatant after infection into 293T cells. pTK161, pTK162, pTK161' and pTK161' were identified by restriction enzyme analyzing. The results showed that the lentiviral vectors pTK161, pTK162, pTK161' and pTK161' were successfully constructed, and the titers of pTK161' and pTK161' reached to 1.54 x 10(6) U/ml and 2.83 x 10(6) U/ml; the activity of cFVIII could be detected at 24 hours after infection of 293T cells by pTK161 and pTK162, and achieved the highest level at 72 hours later. The higher level of cFVIII activity was achieved by transfected with pTK162 than that of pTK161 (p < 0.05), which closed to the cFVIII activity in normal dog plasma. 1/4 of the highest level could be detected 6 weeks later. It is concluded that the prepared HIV1-based lentiviral vectors can infect 293T cells to express cFVIII effectively. The results provide the basis for further studying HIV-1-based lentiviral vector gene therapy for hemophilia A.
Animals ; Dogs ; Factor VIII ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; HIV-1 ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

The present study was purposed to investigate the relation and difference of expression phase between class II transactivator (CIITA) and HLA-DR antigens after IFN-gamma induction, and the inhibition of CIITA and HLA-DR by STAT1-alpha antisense oligonucleotides (STAT1-alpha AS); and to explore the potential effect and significance of CIITA and STAT1-alpha AS in transplantation immunity. T lymphocytes from peripheral blood of healthy subjects were incubated with IFN-gamma at different doses. RT-PCR was used to detect CIITA mRNA and Western blot was used to analyze HLA-DR antigen. Then the optimum dose of IFN-gamma was chosen for the experiment. CIITA mRNA and HLA-DR antigen were detected at various time points. Different doses of STAT1-alpha AS and sense oligonucleotides (STAT1-alpha S) were added to T lymphocytes followed by IFN-gamma. After incubation with IFN-gamma, the expression of CIITA mRNA and HLA-DR was detected once again. The results showed that CIITA mRNA was detectable at 5 hours after IFN-gamma incubation and reached the peak at 14 hours, then declined, but the CIITA mRNA was still found at 23 hours. HLA-DR antigen was detectable at 28 hours after IFN-gamma incubation and reached a peak at 52 hours, then declined. CIITA mRNA expression was positively correlated to HLA-DR expression, and was earlier than the latter. The expression of CIITA mRNA in the AS groups was significantly lower than that in the control group after 5 micromol/L, 10 micromol/L and 20 micromol/L STAT1-alpha AS treatment (P < 0.01). The expression of CIITA mRNA in the S groups was higher than that in the AS groups (P < 0.01), but there was no significant difference between the S group and the control group. The expression of HLA-DR antigen was significantly inhibited by STAT1-alpha AS, and the expression level of HLA-DR protein in the AS group was about 64.3% of that in the control group (P < 0.01), while there was no significant difference in HLA-DR expression between the S group and the control group. The changes in HLA-DR expression were similar to those in CIITA expression after STAT1-alpha AS treatment. It is concluded that CIITA expression is positively correlated with HLA-DR expression, and was detectable earlier than that of latter after IFN-gamma incubation. Stat1-alpha antisense oligonucleotides may have a sequence-specific inhibiting effect on the expression of CIITA and HLA-DR antigen after IFN-gamma incubation in vitro culture, and can prevent T lymphocyte activation. CIITA may play an important role in pathogenesis of transplantation immunity.
Cells, Cultured ; HLA-DR Antigens ; biosynthesis ; genetics ; Humans ; Interferon-gamma ; pharmacology ; Nuclear Proteins ; biosynthesis ; genetics ; Oligonucleotides, Antisense ; antagonists & inhibitors ; RNA, Messenger ; biosynthesis ; genetics ; STAT1 Transcription Factor ; antagonists & inhibitors ; T-Lymphocytes ; cytology ; Trans-Activators ; biosynthesis ; genetics ; Transplantation Immunology ; immunology

BACKGROUND: Mesenchymal stem cells are derived from a variety of tissues, such as bone marrow, pulp, placenta, umbilical cord and adipose tissue. Mesenchymal stem cells from deciduous pulp have strong stemness and biological activity, no rejection, and strong immunoregulation, which are one of excellent cell sources for biotherapy. It is easy and suitable for large-scale production of mesenchymal stem cells from deciduous pulp, thereby laying a good foundation for the industrialization of dental pulp stem cells. OBJECTIVE: To investigate the effect of primary tooth root resorption on the isolation and expansion of dental pulp stem cells, in order to further determine the proper period for tooth extraction for pulp stem cell isolation. METHODS: Totally 173 primary teeth from 173 pupils aged 7-9 years were extracted for the isolation and expansion of dental pulp stem cells. Before tooth extraction, we took X-ray periapical film or orthopantomography of the primary teeth, in accordance with the World Health Organization (WHO) professional inspection standard. Root resorption in primary teeth could be divided into five kinds: root resorption 1/3, root resorption 1/2, root resorption 2/3, complete root resorption, and natural loss of primary teeth. Collected teeth after tooth extraction were placed into a medium within 7 seconds, and stored at in a refrigerator of 2-4 ℃. Then, the teeth were sent to the Oral Stem Cell Bank in Beijing within 24 hours by a professional cold-chain logistics for the isolation, expansion and preservation of dental pulp stem cells. Statistical analysis of the test results was performed. RESULTS AND CONCLUSION: For 32 primary teeth with root resorption 1/3, dental pulp stem cells were successfully extracted from 30 teeth, with a success rate of 94%, and ectopic eruption of permanent teeth was found in 12 cases, with an average eruption time of (2.19±0.18) months. For 35 primary teeth with root resorption 1/2, dental pulp stem cells were successfully extracted from 32 teeth, with a success rate of 92%, and ectopic eruption of permanent teeth was found in 11 cases, with an average eruption time of (1.89±0.13) months. For 59 primary teeth with root resorption 2/3, dental pulp stem cells were successfully extracted from 54 teeth, with a success rate of 92%, and ectopic eruption of permanent teeth was found in 8 cases, with an average eruption time of (1.42±0.12) months. For 37 primary teeth with complete root resorption (the bottom of the pulp was intact), dental pulp stem cells were successfully extracted from 34 teeth, with a success rate of 92%, and ectopic eruption of permanent teeth was found in 2 cases, with an average eruption time of (1.03±0.15) months. For 10 naturally exfoliated primary teeth, dental pulp stem cells were not extracted, and ectopic eruption of permanent teeth was found in 4 cases, with an average eruption time of (0.65±0.23) months. To conclude, the primary teeth naturally exfoliated have no dental pulp with no stem cells; the success rate of extraction is relatively high in primary teeth that have mobility I-II, root resorption 2/3 or complete root resorption but with the complete bottom of the pulp. Moreover, it has no effect on permanent tooth eruption, and it is the best time for collection of primary teeth.

Humans ; Hydrogen-Ion Concentration ; Malassezia ; growth & development ; physiology ; Staphylococcus epidermidis ; growth & development ; physiology

Objective To investigate the epidemioiogical pattern of Borna disease virus (BDV) among different canine breeds in Ili, China, and to analyze its potential phylogeny. Methods BDV p24 RNA fragments were detected from peripheral blood mononuclear cells (PBMCs) of canine by modified nested RT-PCR (nRT-PCR). Possible false positives were excluded by determination of both BDV p40 RNA fragments and PMD19 plasmid standards. Analysis were performed on genetic sequence, homologous comparison, amino acid sequence and phylogeny after p24 positive products were validated. Results BDV p24 RNA fragments were found only in Kazakh Tobet (a shepherd dog) in 8 breeds of 150 cases and their overall positive rate was 11.0% (10/91). Compared with the strain of He/80 from horse and that of S6 from sheep in Germany, the homologous similarities of Kazakh Tobet was 99.2% and 95.7%, and that of amino acid as 100% and 89.3%, respectively. The kinship of Kazakh Tobet was close to He/80 and next to S6. Conclusion There was potential natural BDV infection in Kazakh Tobet in Ili, and its endemic strain was concerned with He/ 80 infecting Ili horse and S6 of German Merino sheep introduced into the region from Germany.

To construct retroviral vector carrying green fluorescent protein (GFP) gene, and determine whether T cells can be infected by retrovirus, the phosphoglycerate kinase (PGK) promoter gene and GFP full-length cDNA were subcloned into the retroviral vector pLXSN. The recombinant vector was transfected into PA317 packaging cells by DNA-calcium phosphate coprecipitation. The G418 resistant clones were selected, then NIH3T3 cells and T cells were infected by the culture supernatant of the retrovirus containing GFP. The results showed that GFP expression in packaging cell line PA317 was detectable under fluorescence microscope, which demonstrated that the GFP retrovirus were able to infect T cells. It is concluded the retrovirus vectors can introduce a foreign gene into T cells efficiently and can be used as important tools to deliver gene into T cells.
Animals ; Cell Line ; Cells, Cultured ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Mice ; Microscopy, Fluorescence ; NIH 3T3 Cells ; Recombinant Fusion Proteins ; genetics ; metabolism ; Retroviridae ; genetics ; T-Lymphocytes ; cytology ; metabolism ; Transfection ; methods