BACKGROUND Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatmen...BACKGROUND Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatment plan for a patient initially treated with four-premolar-extraction camouflage, despite indications for orthognathic surgery.CASE SUMMARY A 23-year-old male sought treatment complaining about his unsatisfactory facial appearance. His maxillary first premolars and mandibular second premolars had been extracted, and a fixed appliance had been used to retract his anterior teeth for two years without improvement. He had a convex profile, a gummy smile, lip incompetence, inadequate maxillary incisor inclination, and almost a class I molar relationship. Cephalometric analysis showed severe skeletal class Ⅱ malocclusion(A point-nasion-B point = 11.5°) with a retrognathic mandible(sella-nasion-B point = 75.9°), a protruded maxilla(sella-nasion-A point = 87.4°), and vertical maxillary excess(upper incisor to palatal plane = 33.2 mm). The excessive lingual inclination of the maxillary incisors(upper incisor to nasion-A point line =-5.5°)was due to previous treatment attempts to compensate for the skeletal class Ⅱ malocclusion. The patient was successfully retreated with decompensating orthodontic treatment combined with orthognathic surgery. The maxillary incisors were repositioned and proclined in the alveolar bone, the overjet was increased, and a space was created for orthognathic surgery, including maxillary impaction, anterior maxillary back-setting, and bilateral sagittal split ramus osteotomy to correct his skeletal anteroposterior discrepancy. Gingival display was reduced, and lip competence was restored. In addition, the results remained stable after 2 years. The patient was satisfied with his new profile as well as with the functional malocclusion at the end of treatment.CONCLUSION This case report provides orthodontists a good example of how to treat an adult with severe skeletal class Ⅱ malocclusion with vertical maxillary excess after an unsatisfactory orthodontic camouflage treatment. Orthodontic and orthognathic treatment can significantly correct a patient’s facial appearance.展开更多
The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the ...The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the light of the properties of the class- waters and lastly, analyses the effect of application.展开更多
A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry （ETAAS） after cloud point extraction （ CPE ）. 1-（ 2-Pyr...A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry （ETAAS） after cloud point extraction （ CPE ）. 1-（ 2-Pyridylazo ） -2- naphthol was used as the chelating reagent and Triton X-114 as the mieellar-forming surfactant. CPE was conducted in a pH 8. 0 medium at 40 ℃ for 10 rain. After the separation of the phases by contrifugafion, the surfactant-rieh phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20μL of the diluted surfactant-rieh phase was injected into the graphite furnace for atomization in the absence of any matrix modifier. Various experimental conditions that affect the extraction and atomization processes were optimized. A detection limit of 5 ng/L was obtained after preconeentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0 ng/mL, and the relative standard deviation was found to be less than 3. 1% for a sample containing 1.0 ng/mL Cu （ Ⅱ ）. This developed method was successfully applied to the determination of uhratraee amounts of Cu in drinking water, tap water, and seawater samples.展开更多
A fragment spanning over exon 2 and intron 2 of major histocompatibility complex B-LB Ⅱ genes was amplified using PCR, cloned and sequenced in 13 individuals from eight Chinese indigenous chicken breeds and one intro...A fragment spanning over exon 2 and intron 2 of major histocompatibility complex B-LB Ⅱ genes was amplified using PCR, cloned and sequenced in 13 individuals from eight Chinese indigenous chicken breeds and one introduced breed. Another 41 sequences of MHC class Ⅱ β from ten vertebrate species were cited from the NCBI GenBank. Thirteen new B-LB Ⅱ alleles were found in the chicken breeds sampled. Alignment of the exon 2 sequences revealed 91.1-97.8% similarity to each other within the chickens sampled, and the chickens shared 84.1-87.0% homology to Phasianus colchicus, 78.5-81.5% similarity to Coturnix japonica. The sequences in poultry showed 62.6-68.1% identity to HLA-DRB1, 50-61.5% similarity to DQB (HLA-, SLA- and H2-BB), 53.7-60% to HLA-DPB and 53.3-57.8% similarity to HLA-DOB. The frequency of nonsynonymous substitutions of nucleotide was higher than that of synonymous substitutions, and the frequencies of nonsynonymous and synonymous substitutions in poultry B-LB Ⅱ genes were lower than those observed in mammalian DRB1 and DQB1 genes. The deduced amino acid sequences of MHC class Ⅱ β1 domain exhibited extreme difference in conversed region and variable region patterns among the various species, but the two conserved cysteines forming disulfide-bond were shown consistent in poultry with that in mammalian species; and the carbohydrate attachment site was found more conserved in chicken, Homo sapiens, Bos taurus, Ovis aries and Capra hircus than in Sus scrofa and rodent animals. Compared with exon 2 of DQB1 genes of Homo sapiens, ruminant species and Sus scrofa, the differentia that the deletion of six nucleotides at position195 to 200 of exon 2 of DQB1 genes, and insertion of three nucleotides at position 247 to 249 of the exon 2 existed in rodent species were found, which led to the absence of three AA residues at position 65, 66, and 67 within β1 domain of DQB1 chain, and the insertion of one AA residue at position 85. The difference of the deletion of six nucleotides at position 72 to 77 of exon 2 of DPB1 genes was observed with Homo sapiens DQB1, which caused absence of three AA residues at position 24, 25, and 26 of β1 domain of DPB1 chain. The phylogenetic tree revealed that the B-LB Ⅱ sequences from poultry are not orthologous to the class Ⅱ MHC β-chain genes of mammalian species. The tree indicated that genetic evolutionary relationship of chickens with Phasianus colchicus was much closer than with Coturnix japonica, and the DQB and DPB clusters are more tightly related to each other than to the remaining clusters.展开更多
Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire （MEAW） technique on postpeak Class Ⅱ Division 1 patients. Methodology In this retrospectiv...Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire （MEAW） technique on postpeak Class Ⅱ Division 1 patients. Methodology In this retrospective study, 16 postpeak Class Ⅱ Division 1 patients successfully corrected using a non-extraction and MEAW technique were cephalometrically evaluated and compared with 16 matched control subjects treated using an extraction technique. Using CorelDRAW software, standardized digital cephalograms preand post-active treatments were traced and a reference grid was set up. The superimpositions were based on the cranial base, the mandibular and the maxilla regions,and skeletal and dental changes were measured. Changes following treatment were evaluated using the paired-sample t-test. Student＇s t-test for unpaired samples was used to assess the differences in changes between the MEAW and the extraction control groups. Results The correction of the molar relationships comprised 54% skeletal change （mainly the advancement of the mandible） and 46% dental change. Correction of the anterior teeth relationships comprised 30% skeletal change and 70% dental change. Conclusion The MEAW technique can produce the desired vertical and sagittal movement of the tooth segment and then effectively stimulate mandibular advancement by utilizing the residual growth potential of the condyle.展开更多
Purpose:To investigate the density, distribution and morphology of macrophages and MHC class II -positive dendritic cells in the iris and ciliary body of lewis rats. Methods:Immunohistochemistry was performed using mo...Purpose:To investigate the density, distribution and morphology of macrophages and MHC class II -positive dendritic cells in the iris and ciliary body of lewis rats. Methods:Immunohistochemistry was performed using monoclonal antibodies specific to monocytes and macrophages (ED1,ED2) and MHC class II -positive cells (OX6) on wholemounts of the iris-ciliary body complex isolated form normal lewis rats.Results:A well developed network of macrophages was present in the iris and ciliary body of normal lewis rats. These cells, morphologically displaying dendriti-form or pleiomorphic appearance, were more densely arranged in mid-iris (950 + 189 cells/mm2) than in iris base (482 ± 78 cells/mm2) and pupil margin (595 ± 92 cells/mm2). A similar network of MHC class II -positive cells with a cell density 452 ± 78 cells/mm2 was almost uniformly distributed in the iris of normal lewis rats.Conclusions : A network of macrophages and MHC class II -positive cells was established in the iris and ciliary body of展开更多
AIM: To investigate the role of MHC classⅡin the modulation of gastric epithelial cell apoptosis induced by H pylon infection. METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist ...AIM: To investigate the role of MHC classⅡin the modulation of gastric epithelial cell apoptosis induced by H pylon infection. METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC classⅡand CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively. RESULTS: Pretreatment of N87 cells with the anti-MHC classⅡIgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class n resulted in markedly reduced caspase activation, while simple ligation of MHC classⅡdid not. Crosslinking of MHC class n also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC classⅡIgM blocked the recruitment of FADD to the cell surface. CONCLUSION: The ability of MHC class n to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. The crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC classⅡto modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.展开更多
The title Mn（Ⅱ） coordination polymer,poly{[heptaaqua-（μ4-bi-phenyl-3,3？,5,5？-tetracarboxylate）-bimanganese（Ⅱ）] pentahydrate},[Mn_2（bpta）（H_2O）_7]_n·5n H_2O（I）,is crystallized from a mixture of bi...The title Mn（Ⅱ） coordination polymer,poly{[heptaaqua-（μ4-bi-phenyl-3,3？,5,5？-tetracarboxylate）-bimanganese（Ⅱ）] pentahydrate},[Mn_2（bpta）（H_2O）_7]_n·5n H_2O（I）,is crystallized from a mixture of biphenyl-3,3？,5,5？-tetracarboxylic acid（H_4bpta） and MnCl_2·4H_2O in waterethanol under room temperature. Its asymmetric unit consists of one and two halves of crystallographically independent Mn（Ⅱ） cations,one fully deprotonated H4 bpta ligand,seven coordinated water molecules and five solvent water as guest molecules. In I,each Mn（Ⅱ） atom is octahedrally coordinated by six oxygen atoms from bpta^（4-） anions and coordinated water molecules. In the Mn（Ⅱ） cations,one half Mn（Ⅱ） ion of them located at a 2-fold axis generating a trinuclear [Mn_3（H_2O）_2（RCOO）_2] linker by μ1,1-O（water） and μ1,3-O,O？（carboxylate） bridges and another half Mn（Ⅱ） ion with an inversion is a mononuclear linker. These neighbouring trinuclear and mononuclear Mn（Ⅱ） cations are linked together by biphenyl-3,3？,5,5？-tetracarboxylates to form a three-dimensional framework with a（42.84） topology of a（4,4）-connected net,in which the positions of the trinuclear [Mn_3（H_2O）_2（R-COO）_2] linker as a 4-connector linking four bpta^（4-） ligands in I reproduce an eagle-shaped arrangement. The polymeric structure exhibits a water channel with an accessible void of 797.1 ？~3,amounting to 15.7% of the total unit-cell volume. Each of the cavities in the network is occupied by solvent water molecules.展开更多
AIM: To investigate the relationship between the polymorphism of class Ⅱ transactivator (CⅡTA) gene promoters and chronic hepatitis B (CHB).METHODS: Genomic DNA was prepared from peripheral blood leukocytes. Promote...AIM: To investigate the relationship between the polymorphism of class Ⅱ transactivator (CⅡTA) gene promoters and chronic hepatitis B (CHB).METHODS: Genomic DNA was prepared from peripheral blood leukocytes. Promoters Ⅰ, Ⅲ and Ⅳ of gene were analyzed respectively with polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) in 65 patients with CHB, 26 patients with acute hepatitis B (AHB) and 85 normal controls.RESULTS: No abnormal migration was found in PCR-SSCP analysis of the three promoters in the three groups. Also,no sequential difference was observed at the three promoters among the CHB patients, AHB patients and normal controls.CONCLUSION: No polymorphism in promoters Ⅰ, Ⅲ and Ⅳ of CⅡTA gene exists in CHB patients, ABH patients and normal controls, suggesting that the promoter of CⅡTA gene might be a conserved domain.展开更多
AIM: To investigate the role of MHC class Ⅱ in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonis...AIM: To investigate the role of MHC class Ⅱ in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specifi c for MHC class Ⅱ and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a ? uorometric assay, a cytometric bead array, and confocal microscopy, respectively.RESULTS: Pretreatment of N87 cells with the anti-MHC class Ⅱ IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class Ⅱ resulted in a marked re-duced caspase activation, while simple ligation of MHC class Ⅱ did not. Crosslinking of MHC class Ⅱ also re-sulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class Ⅱ IgM blocked the recruitment of FADD to the cell surface.CONCLUSION: The results presented here demonstrate that the ability of MHC class Ⅱ to modulate gastric epi-thelial apoptosis is at least partially dependent on its crosslinking. Furthermore, while previous research has demonstrated that MHC class Ⅱ signaling can be pro-apoptotic during extended ligation, we have shown that the crosslinking of this molecule has anti-apoptotic ef-fects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class Ⅱ to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.展开更多
文摘BACKGROUND Patient satisfaction with facial appearance at the end of orthodontic camouflage treatment is very important, especially for skeletal malocclusion. This case report highlights the importance of the treatment plan for a patient initially treated with four-premolar-extraction camouflage, despite indications for orthognathic surgery.CASE SUMMARY A 23-year-old male sought treatment complaining about his unsatisfactory facial appearance. His maxillary first premolars and mandibular second premolars had been extracted, and a fixed appliance had been used to retract his anterior teeth for two years without improvement. He had a convex profile, a gummy smile, lip incompetence, inadequate maxillary incisor inclination, and almost a class I molar relationship. Cephalometric analysis showed severe skeletal class Ⅱ malocclusion(A point-nasion-B point = 11.5°) with a retrognathic mandible(sella-nasion-B point = 75.9°), a protruded maxilla(sella-nasion-A point = 87.4°), and vertical maxillary excess(upper incisor to palatal plane = 33.2 mm). The excessive lingual inclination of the maxillary incisors(upper incisor to nasion-A point line =-5.5°)was due to previous treatment attempts to compensate for the skeletal class Ⅱ malocclusion. The patient was successfully retreated with decompensating orthodontic treatment combined with orthognathic surgery. The maxillary incisors were repositioned and proclined in the alveolar bone, the overjet was increased, and a space was created for orthognathic surgery, including maxillary impaction, anterior maxillary back-setting, and bilateral sagittal split ramus osteotomy to correct his skeletal anteroposterior discrepancy. Gingival display was reduced, and lip competence was restored. In addition, the results remained stable after 2 years. The patient was satisfied with his new profile as well as with the functional malocclusion at the end of treatment.CONCLUSION This case report provides orthodontists a good example of how to treat an adult with severe skeletal class Ⅱ malocclusion with vertical maxillary excess after an unsatisfactory orthodontic camouflage treatment. Orthodontic and orthognathic treatment can significantly correct a patient’s facial appearance.
文摘The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the light of the properties of the class- waters and lastly, analyses the effect of application.
基金the Analysis and Testing Foundation of Zhejiang Province(No 04045)
文摘A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry （ETAAS） after cloud point extraction （ CPE ）. 1-（ 2-Pyridylazo ） -2- naphthol was used as the chelating reagent and Triton X-114 as the mieellar-forming surfactant. CPE was conducted in a pH 8. 0 medium at 40 ℃ for 10 rain. After the separation of the phases by contrifugafion, the surfactant-rieh phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20μL of the diluted surfactant-rieh phase was injected into the graphite furnace for atomization in the absence of any matrix modifier. Various experimental conditions that affect the extraction and atomization processes were optimized. A detection limit of 5 ng/L was obtained after preconeentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0 ng/mL, and the relative standard deviation was found to be less than 3. 1% for a sample containing 1.0 ng/mL Cu （ Ⅱ ）. This developed method was successfully applied to the determination of uhratraee amounts of Cu in drinking water, tap water, and seawater samples.
基金This study was supported by"948"Project of China(2001-361)Key Project of National Basic Research and De-velopmental Plan(G2000016103)of China.
文摘A fragment spanning over exon 2 and intron 2 of major histocompatibility complex B-LB Ⅱ genes was amplified using PCR, cloned and sequenced in 13 individuals from eight Chinese indigenous chicken breeds and one introduced breed. Another 41 sequences of MHC class Ⅱ β from ten vertebrate species were cited from the NCBI GenBank. Thirteen new B-LB Ⅱ alleles were found in the chicken breeds sampled. Alignment of the exon 2 sequences revealed 91.1-97.8% similarity to each other within the chickens sampled, and the chickens shared 84.1-87.0% homology to Phasianus colchicus, 78.5-81.5% similarity to Coturnix japonica. The sequences in poultry showed 62.6-68.1% identity to HLA-DRB1, 50-61.5% similarity to DQB (HLA-, SLA- and H2-BB), 53.7-60% to HLA-DPB and 53.3-57.8% similarity to HLA-DOB. The frequency of nonsynonymous substitutions of nucleotide was higher than that of synonymous substitutions, and the frequencies of nonsynonymous and synonymous substitutions in poultry B-LB Ⅱ genes were lower than those observed in mammalian DRB1 and DQB1 genes. The deduced amino acid sequences of MHC class Ⅱ β1 domain exhibited extreme difference in conversed region and variable region patterns among the various species, but the two conserved cysteines forming disulfide-bond were shown consistent in poultry with that in mammalian species; and the carbohydrate attachment site was found more conserved in chicken, Homo sapiens, Bos taurus, Ovis aries and Capra hircus than in Sus scrofa and rodent animals. Compared with exon 2 of DQB1 genes of Homo sapiens, ruminant species and Sus scrofa, the differentia that the deletion of six nucleotides at position195 to 200 of exon 2 of DQB1 genes, and insertion of three nucleotides at position 247 to 249 of the exon 2 existed in rodent species were found, which led to the absence of three AA residues at position 65, 66, and 67 within β1 domain of DQB1 chain, and the insertion of one AA residue at position 85. The difference of the deletion of six nucleotides at position 72 to 77 of exon 2 of DPB1 genes was observed with Homo sapiens DQB1, which caused absence of three AA residues at position 24, 25, and 26 of β1 domain of DPB1 chain. The phylogenetic tree revealed that the B-LB Ⅱ sequences from poultry are not orthologous to the class Ⅱ MHC β-chain genes of mammalian species. The tree indicated that genetic evolutionary relationship of chickens with Phasianus colchicus was much closer than with Coturnix japonica, and the DQB and DPB clusters are more tightly related to each other than to the remaining clusters.
文摘Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire （MEAW） technique on postpeak Class Ⅱ Division 1 patients. Methodology In this retrospective study, 16 postpeak Class Ⅱ Division 1 patients successfully corrected using a non-extraction and MEAW technique were cephalometrically evaluated and compared with 16 matched control subjects treated using an extraction technique. Using CorelDRAW software, standardized digital cephalograms preand post-active treatments were traced and a reference grid was set up. The superimpositions were based on the cranial base, the mandibular and the maxilla regions,and skeletal and dental changes were measured. Changes following treatment were evaluated using the paired-sample t-test. Student＇s t-test for unpaired samples was used to assess the differences in changes between the MEAW and the extraction control groups. Results The correction of the molar relationships comprised 54% skeletal change （mainly the advancement of the mandible） and 46% dental change. Correction of the anterior teeth relationships comprised 30% skeletal change and 70% dental change. Conclusion The MEAW technique can produce the desired vertical and sagittal movement of the tooth segment and then effectively stimulate mandibular advancement by utilizing the residual growth potential of the condyle.
基金a grant from Pubic Health Ministry of ChinaNatural Science Fundation of Guangdong Province
文摘Purpose:To investigate the density, distribution and morphology of macrophages and MHC class II -positive dendritic cells in the iris and ciliary body of lewis rats. Methods:Immunohistochemistry was performed using monoclonal antibodies specific to monocytes and macrophages (ED1,ED2) and MHC class II -positive cells (OX6) on wholemounts of the iris-ciliary body complex isolated form normal lewis rats.Results:A well developed network of macrophages was present in the iris and ciliary body of normal lewis rats. These cells, morphologically displaying dendriti-form or pleiomorphic appearance, were more densely arranged in mid-iris (950 + 189 cells/mm2) than in iris base (482 ± 78 cells/mm2) and pupil margin (595 ± 92 cells/mm2). A similar network of MHC class II -positive cells with a cell density 452 ± 78 cells/mm2 was almost uniformly distributed in the iris of normal lewis rats.Conclusions : A network of macrophages and MHC class II -positive cells was established in the iris and ciliary body of
基金the National Institutes of Health Grants DK50669 and DK56338. EB was a recipient of a fellowship under National Institutes of Health T32 AI007536-06 Training Grant
文摘AIM: To investigate the role of MHC classⅡin the modulation of gastric epithelial cell apoptosis induced by H pylon infection. METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC classⅡand CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively. RESULTS: Pretreatment of N87 cells with the anti-MHC classⅡIgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class n resulted in markedly reduced caspase activation, while simple ligation of MHC classⅡdid not. Crosslinking of MHC class n also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC classⅡIgM blocked the recruitment of FADD to the cell surface. CONCLUSION: The ability of MHC class n to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. The crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC classⅡto modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.
基金supported by the National Natural Science Foundation of China(No.21571118)
文摘The title Mn（Ⅱ） coordination polymer,poly{[heptaaqua-（μ4-bi-phenyl-3,3？,5,5？-tetracarboxylate）-bimanganese（Ⅱ）] pentahydrate},[Mn_2（bpta）（H_2O）_7]_n·5n H_2O（I）,is crystallized from a mixture of biphenyl-3,3？,5,5？-tetracarboxylic acid（H_4bpta） and MnCl_2·4H_2O in waterethanol under room temperature. Its asymmetric unit consists of one and two halves of crystallographically independent Mn（Ⅱ） cations,one fully deprotonated H4 bpta ligand,seven coordinated water molecules and five solvent water as guest molecules. In I,each Mn（Ⅱ） atom is octahedrally coordinated by six oxygen atoms from bpta^（4-） anions and coordinated water molecules. In the Mn（Ⅱ） cations,one half Mn（Ⅱ） ion of them located at a 2-fold axis generating a trinuclear [Mn_3（H_2O）_2（RCOO）_2] linker by μ1,1-O（water） and μ1,3-O,O？（carboxylate） bridges and another half Mn（Ⅱ） ion with an inversion is a mononuclear linker. These neighbouring trinuclear and mononuclear Mn（Ⅱ） cations are linked together by biphenyl-3,3？,5,5？-tetracarboxylates to form a three-dimensional framework with a（42.84） topology of a（4,4）-connected net,in which the positions of the trinuclear [Mn_3（H_2O）_2（R-COO）_2] linker as a 4-connector linking four bpta^（4-） ligands in I reproduce an eagle-shaped arrangement. The polymeric structure exhibits a water channel with an accessible void of 797.1 ？~3,amounting to 15.7% of the total unit-cell volume. Each of the cavities in the network is occupied by solvent water molecules.
基金Supported by the National Natural Science Foundation of China,No. 30270597
文摘AIM: To investigate the relationship between the polymorphism of class Ⅱ transactivator (CⅡTA) gene promoters and chronic hepatitis B (CHB).METHODS: Genomic DNA was prepared from peripheral blood leukocytes. Promoters Ⅰ, Ⅲ and Ⅳ of gene were analyzed respectively with polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) in 65 patients with CHB, 26 patients with acute hepatitis B (AHB) and 85 normal controls.RESULTS: No abnormal migration was found in PCR-SSCP analysis of the three promoters in the three groups. Also,no sequential difference was observed at the three promoters among the CHB patients, AHB patients and normal controls.CONCLUSION: No polymorphism in promoters Ⅰ, Ⅲ and Ⅳ of CⅡTA gene exists in CHB patients, ABH patients and normal controls, suggesting that the promoter of CⅡTA gene might be a conserved domain.
基金Supported by the National Institutes of Health Grants DK50669, DK56338 and National Institutes of Health T32 AI007536-06 Training Grant
文摘AIM: To investigate the role of MHC class Ⅱ in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specifi c for MHC class Ⅱ and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a ? uorometric assay, a cytometric bead array, and confocal microscopy, respectively.RESULTS: Pretreatment of N87 cells with the anti-MHC class Ⅱ IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class Ⅱ resulted in a marked re-duced caspase activation, while simple ligation of MHC class Ⅱ did not. Crosslinking of MHC class Ⅱ also re-sulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class Ⅱ IgM blocked the recruitment of FADD to the cell surface.CONCLUSION: The results presented here demonstrate that the ability of MHC class Ⅱ to modulate gastric epi-thelial apoptosis is at least partially dependent on its crosslinking. Furthermore, while previous research has demonstrated that MHC class Ⅱ signaling can be pro-apoptotic during extended ligation, we have shown that the crosslinking of this molecule has anti-apoptotic ef-fects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class Ⅱ to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.
