The strain induced ferrite formed under different conditions was observed with SEM and optical microscope. The nucleation sites of strain induced ferrite include grain boundary, grain inside, deformed band and annea...The strain induced ferrite formed under different conditions was observed with SEM and optical microscope. The nucleation sites of strain induced ferrite include grain boundary, grain inside, deformed band and annealing twin boundary. The shapes of the ferrite accordingly are equiaxed irregular polygonal, strip shaped and acicular.展开更多
Ugi-4CC(four-component condensation) reaction is one of isonitrile-based MCR's(multicomponent reactions), which is started with an amine, an aldehyde, a carboxylic acid and an isocyanide, after full use of the spe...Ugi-4CC(four-component condensation) reaction is one of isonitrile-based MCR's(multicomponent reactions), which is started with an amine, an aldehyde, a carboxylic acid and an isocyanide, after full use of the specialty of isonitrile and be used to build a series of compounds with different structural skeletons by using diverse inputs. In our work, two kinds of isonitriles were synthesized and a parallel synthesis of an α-acylarnino amide library was performed to modify the Ugi reaction conditions.展开更多
Background The treatment of hypoparathyroidism (HPT) is still a difficult clinical problem, which necessitates a new therapy. Gene therapy of HPT has been valuable, but how to improve the gene transfer efficiency and ...Background The treatment of hypoparathyroidism (HPT) is still a difficult clinical problem, which necessitates a new therapy. Gene therapy of HPT has been valuable, but how to improve the gene transfer efficiency and expression stability is a problem. This study was designed to optimize the gene therapy of HPT with hematopoietic stem cells (HSCs) recombined with the parathyroid hormone (PTH) gene. Methods The human PTH gene was amplified by polymerase chain reaction (PCR) from pcDNA3.1-PTH vectors and inserted into murine stem cell virus (MSCV) vectors with double enzyme digestion (EcoRI and XhoI). The recombinant vectors were transfected into PA317 packaging cell lines by the lipofectin method and screened by G418 selective medium. The condensed recombinant retroviruses were extracted and used to infect HSCs, which were injected into mice suffering from HPT. The change of symptoms and serum levels of PTH and calcium in each group of mice were investigated. Results The human PTH gene was inserted into MSCV vectors successfully and the titres were up to 2×107 colony forming unit (CFU)/ml in condensed retroviral solution. The secretion of PTH reached 15 ng·10-6·cell-1 per 48 hours. The wild type viruses were not detected via PCR amplification, so they were safe for use. The mice suffering from HPT recovered quickly and the serum levels of calcium and PTH remained normal for about three months after the HSCs recombined with PTH were injected into them. The therapeutic effect of this method was better than simple recombinant retroviruses injection.Conclusions The recombinant retroviral vectors MSCV-PTH and the high-titre condensed retroviral solution recombined with the PTH gene are obtained. The recombinant retroviral solution could infect HSCs at a high rate of efficiency. The infected HSCs could cure HPT in mice. This method has provided theoretical evidence for the clinical gene therapy of HPT.展开更多
Retina is a multilayer and highly specialized tissue important in converting light into neural signals. In humans, the critical period for the formation of complex multiplayer structure takes place during embryogenesi...Retina is a multilayer and highly specialized tissue important in converting light into neural signals. In humans, the critical period for the formation of complex multiplayer structure takes place during embryogenesis be- tween 12 and 28 weeks. The morphologic changes during retinal development in humans have been studied but little is known about the molecular events essential for the formation of the retina. To gain further insights into this process, cDNA microarrays containing 16361 human gene probes were used to measure the gene expression levels in retinas. Of the 16361 genes, 68.7%, 71.4% and 69.7% showed positive hybridiza- tion with cDNAs made from 12—16 week fetal, 22—26 week fetal and adult retinas. A total of 814 genes showed a mini- mum of 3-fold changes between the lowest and highest ex- pression levels among three time points and among them, 106 genes had expression levels with the hybridization intensity above 100 at one or more time points. The clustering analysis suggested that the majority of differentially expressed genes were down-regulated during the retinal development. The differentially expressed genes were further classified accord- ing to functions of known genes, and were ranked in de- creasing order according to frequency: development, differ- entiation, signal transduction, protein synthesis and transla- tion, metabolism, DNA binding and transcription, DNA syn- thesis-repair-recombination, immuno-response, ion channel- transport, cell receptor, cytoskeleton, cell cycle, pro-oncogene, stress and apoptosis related genes. Among these 106 differen- tially expressed genes, 60 are already present in NEI retina cDNA or EST Databank but the remaining 46 genes are ab- sent and thus identified as “function unknown”. To validate gene expression data from the microarray, real-time RT-PCR was performed for 46 “function unknown” genes and 6 known retina specific expression genes, and β-actin was used as internal control. Twenty-seven of these genes showed very similar expression profiles between the microarray and real-time RT-PCR data. In situ hybridization revealed both expression level and cellular distribution of NNAT in retina. Finally, the chromosomal locations of 106 differentially ex- pressed genes were also searched and one of these genes is associated with autosomal dominant cone or cone-rod dys- trophy. The data from present study provide insights into understanding genetic programs during human retinal de- velopment and help identify additional retinal disease genes.展开更多
文摘The strain induced ferrite formed under different conditions was observed with SEM and optical microscope. The nucleation sites of strain induced ferrite include grain boundary, grain inside, deformed band and annealing twin boundary. The shapes of the ferrite accordingly are equiaxed irregular polygonal, strip shaped and acicular.
文摘Ugi-4CC(four-component condensation) reaction is one of isonitrile-based MCR's(multicomponent reactions), which is started with an amine, an aldehyde, a carboxylic acid and an isocyanide, after full use of the specialty of isonitrile and be used to build a series of compounds with different structural skeletons by using diverse inputs. In our work, two kinds of isonitriles were synthesized and a parallel synthesis of an α-acylarnino amide library was performed to modify the Ugi reaction conditions.
文摘Background The treatment of hypoparathyroidism (HPT) is still a difficult clinical problem, which necessitates a new therapy. Gene therapy of HPT has been valuable, but how to improve the gene transfer efficiency and expression stability is a problem. This study was designed to optimize the gene therapy of HPT with hematopoietic stem cells (HSCs) recombined with the parathyroid hormone (PTH) gene. Methods The human PTH gene was amplified by polymerase chain reaction (PCR) from pcDNA3.1-PTH vectors and inserted into murine stem cell virus (MSCV) vectors with double enzyme digestion (EcoRI and XhoI). The recombinant vectors were transfected into PA317 packaging cell lines by the lipofectin method and screened by G418 selective medium. The condensed recombinant retroviruses were extracted and used to infect HSCs, which were injected into mice suffering from HPT. The change of symptoms and serum levels of PTH and calcium in each group of mice were investigated. Results The human PTH gene was inserted into MSCV vectors successfully and the titres were up to 2×107 colony forming unit (CFU)/ml in condensed retroviral solution. The secretion of PTH reached 15 ng·10-6·cell-1 per 48 hours. The wild type viruses were not detected via PCR amplification, so they were safe for use. The mice suffering from HPT recovered quickly and the serum levels of calcium and PTH remained normal for about three months after the HSCs recombined with PTH were injected into them. The therapeutic effect of this method was better than simple recombinant retroviruses injection.Conclusions The recombinant retroviral vectors MSCV-PTH and the high-titre condensed retroviral solution recombined with the PTH gene are obtained. The recombinant retroviral solution could infect HSCs at a high rate of efficiency. The infected HSCs could cure HPT in mice. This method has provided theoretical evidence for the clinical gene therapy of HPT.
文摘Retina is a multilayer and highly specialized tissue important in converting light into neural signals. In humans, the critical period for the formation of complex multiplayer structure takes place during embryogenesis be- tween 12 and 28 weeks. The morphologic changes during retinal development in humans have been studied but little is known about the molecular events essential for the formation of the retina. To gain further insights into this process, cDNA microarrays containing 16361 human gene probes were used to measure the gene expression levels in retinas. Of the 16361 genes, 68.7%, 71.4% and 69.7% showed positive hybridiza- tion with cDNAs made from 12—16 week fetal, 22—26 week fetal and adult retinas. A total of 814 genes showed a mini- mum of 3-fold changes between the lowest and highest ex- pression levels among three time points and among them, 106 genes had expression levels with the hybridization intensity above 100 at one or more time points. The clustering analysis suggested that the majority of differentially expressed genes were down-regulated during the retinal development. The differentially expressed genes were further classified accord- ing to functions of known genes, and were ranked in de- creasing order according to frequency: development, differ- entiation, signal transduction, protein synthesis and transla- tion, metabolism, DNA binding and transcription, DNA syn- thesis-repair-recombination, immuno-response, ion channel- transport, cell receptor, cytoskeleton, cell cycle, pro-oncogene, stress and apoptosis related genes. Among these 106 differen- tially expressed genes, 60 are already present in NEI retina cDNA or EST Databank but the remaining 46 genes are ab- sent and thus identified as “function unknown”. To validate gene expression data from the microarray, real-time RT-PCR was performed for 46 “function unknown” genes and 6 known retina specific expression genes, and β-actin was used as internal control. Twenty-seven of these genes showed very similar expression profiles between the microarray and real-time RT-PCR data. In situ hybridization revealed both expression level and cellular distribution of NNAT in retina. Finally, the chromosomal locations of 106 differentially ex- pressed genes were also searched and one of these genes is associated with autosomal dominant cone or cone-rod dys- trophy. The data from present study provide insights into understanding genetic programs during human retinal de- velopment and help identify additional retinal disease genes.
