In multiloci-based genetic association studies of complex diseases, a powerful and high efficient tool for analyses oflinkage disequilibrium (LD) between markers, haplotype distributions and many chi-square/p values w...In multiloci-based genetic association studies of complex diseases, a powerful and high efficient tool for analyses oflinkage disequilibrium (LD) between markers, haplotype distributions and many chi-square/p values with a large numberof samples has been sought for long. In order to achieve the goal of obtaining meaningful results directly from raw data,we developed a robust and user-friendly software platform with a series of tools for analysis in association study withhigh efficiency. The platform has been well evaluated by several sets of real data.展开更多
The Hedgehog （Hh） family of secreted signaling proteins plays a critical role in regulating the development of several tissues and organ systems. The ability of Hh proteins to exert their biological effects is regul...The Hedgehog （Hh） family of secreted signaling proteins plays a critical role in regulating the development of several tissues and organ systems. The ability of Hh proteins to exert their biological effects is regulated by a series of post-translational processes. These processes include an intramolecular cleavage, covalent addition of cholesterol and/or palmitate, and conversion into a multimeric freely diffusible form. The processing of Hh proteins affects their trafficking, potency, and ability to signal over several cell diameters. Here we review the current understanding of the Hh signaling mechanisms that govern the establishment of the Hh gradient and the transduction of the Hh signal in the light of recent data.展开更多
Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMAD...Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMADS6, in specifying floral organ and meristem identities in rice (Oryza sativa L.). OsMADS6 was strongly ex- pressed in the floral meristem at early stages. Subsequently, OsMADS6 transcripts were mainly detectable in paleas, lodicules, carpels and the integument of ovule, as well as in the receptacle. Compared to wild type plants, osmads6 mutants displayed altered palea identity, extra glume-like or mosaic organs, abnormal carpel development and loss of floral meristem determinacy. Strikingly, mutation of a SEPALLATA (SEP)-like gene, OsMADS1 (LHS1), enhanced the defect of osmads6 flowers, and no inner floral organs or glume-like structures were observed in whorls 2 and 3 of osmadsl-z osmads6-1 flowers. Furthermore, the osmadsl-z osmads6-1 double mutants developed severely indetermi- nate floral meristems. Our finding, therefore, suggests that the ancient OsMADS6 gene is able to specify "floral state" by determining floral organ and meristem identities in monocot crop rice together with OsMADS1.展开更多
Vertebrate digits are essential structures for movement, feeding and communication. Specialized regions of the developing limb bud including the zone of polarizing activity （ZPA）, the apical ectodermal ridge （AER）...Vertebrate digits are essential structures for movement, feeding and communication. Specialized regions of the developing limb bud including the zone of polarizing activity （ZPA）, the apical ectodermal ridge （AER）, and the non-ridge ectoderm regulate the patterning of digits. Although a series of signaling molecules have been characterized as patterning signals from the organizing centers, the delicate cellular and molecular mechanisms that interpret how these patterning signals control the detailed digit anatomy remain unclear, Recent studies from model organisms and human hand malformations provide new insights into the mechanisms regulating this process. Here, we review the current understanding of the genetic networks governing digit morphogenesis展开更多
Objective Thyroid hormones(THs)regulate multiple physiological activities in the liver,including cellular metabolism,differentiation,and cell growth,and play important roles in the pathogenesis of hepatocellular carci...Objective Thyroid hormones(THs)regulate multiple physiological activities in the liver,including cellular metabolism,differentiation,and cell growth,and play important roles in the pathogenesis of hepatocellular carcinoma(HCC).Thyroid peroxidase(TPO)is a key molecule involved in the THs synthesis and signaling pathway.As an epigenetic modification,DNA methylation has a critical role in tumorigenesis with diagnostic potential.However,the connection between THs and DNA methylation has been rarely investigated.Methods The methylation of key TH-related genes was analyzed by in-house epigenome-wide scanning,and we further analyzed the methylation levels of the TPO promotor in 164 sample pairs of HCC and adjacent non-cancerous tissues by Sequenom EpiTYPER assays,and evaluated their clinical implications.Results We identified that the methylation of the TPO promoter was downregulated in the HCC tissues(P<0.0001)with a mean difference ranging from 18.5%to 22.3%.This methylation pattern correlated with several clinical factors,including a multi-satellite tumor,fibrous capsule,and the presence of tumor thrombus.The receiver operator characteristic(ROC)curve analysis further confirmed that the percent methylated reference(PMR)values for TPO were predictive of the tumor[the area under the curve(AUC)ranged from 0.755 to 0.818]and the thrombosis in the HCC patients(the AUC ranged from 0.706 to 0.777).Conclusion These findings demonstrated that epigenetic alterations of TPO,as indicated by the PMR values,were a potential biomarker for HCC patients with tumor thrombosis.展开更多
Objective To prepare and characterize polyelectrolyte multilayer film coated microbubbles for use as ultrasound contrast agent(UCA)and evaluate its effects in ultrasonic imaging on normal rabbit's liver parenchyma...Objective To prepare and characterize polyelectrolyte multilayer film coated microbubbles for use as ultrasound contrast agent(UCA)and evaluate its effects in ultrasonic imaging on normal rabbit's liver parenchyma.Methods Perfluorocarbon(PFC)-containing microbubbles(ST68-PFC)were prepared by sonication based on surfactant(Span 60 and Tween 80).Subsequently,the resulting ST68-PFC microbubbles were coated using oppositely charged polyelectrolytes by microbubble-templated layer-by-layer self-assembly technique via electrostatic interaction.The enhancement effects in ultrasonic imaging on normal rabbit's liver parenchyma were assessed.Results The obtained microbubbles exhibited a narrow size distribution.The polyelectrolytes were successfully assembled onto the surface of ST68-PFC microbubbles.In vivo experiment showed that polyelectrolyte multilayer film coated UCA effectively enhanced the imaging of rabbit's liver parenchyma.Conclusions The novel microbubbles UCA coated with polyelectrolyte multilayer,when enabled more function,has no obvious difference in enhancement effects compared with the pre-modified microbubbles.The polymers with chemically active groups(such as amino group and carboxyl group)can be used as the outermost layer for attachment of targeting ligands onto microbubbles,allowing selective targeting of the microbubbles to combine with desired sites.展开更多
AIM: To search candidate tumor suppressor genes (TSGs) on chromosome 4q through detecting high loss of heterozygosity (LOH) regions in sporadic colorectal carcinoma in Chinese patients. METHODS: Thirteen fluorescent l...AIM: To search candidate tumor suppressor genes (TSGs) on chromosome 4q through detecting high loss of heterozygosity (LOH) regions in sporadic colorectal carcinoma in Chinese patients. METHODS: Thirteen fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by polymerase chain reaction (PCR). PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. Comparison between LOH frequency and clinicopathological factors were performed by χ2 test. RESULTS: Data were collected on all informative loci. The average LOH frequency on 4q was 28.56%. The D4S2915 locus showed highest LOH frequency (36.17%). Two obvious deletion regions were detected: one between D4S3000 and D4S2915 locus (4q12-21.1), another flanked by D4S407 and D4S2939 locus (4q25-31.1). None case showed complete deletion of 4q, most cases displayed interstitial deletion pattern solely. Furthermore, compared with clinicopathological features, a significant relationship was observed between LOH frequencies on D4S3018locus. In tumors larger than 5 cm in diameter, LOH frequency was significantly higher than tumors that were less than 5 cm (56% vs 13.79%, P = 0.01). On D4S1534 locus, LOH was significantly associated with liver metastasis (80% vs 17.25%, P = 0.012). No relationship was detected on other locus compared with clinicopathologial features. CONCLUSION: By high resolution deletion mapping, two high frequency regions of LOH (4q12-21.1 and 4q25-31.1) were detected, which may contribute to locate TSGs on chromosome 4q involved in carcinogenesis and progression of sporadic colorectal carcinoma.展开更多
AIM: To study the candidate tumor suppressor genes (TSG) on chromosome 4p by detecting the high frequency of loss of heterozygosity (LOH) in sporadic colorectal carcinoma in Chinese patients.METHODS: Seven fluorescent...AIM: To study the candidate tumor suppressor genes (TSG) on chromosome 4p by detecting the high frequency of loss of heterozygosity (LOH) in sporadic colorectal carcinoma in Chinese patients.METHODS: Seven fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by PCR. PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. The same procedure was performed by the other six microsatellite markers spanning D4S3013 locus to make further detailed deletion mapping. Comparison between LOH frequency and clinicopathological factors was performed by χ2 test.RESULTS: Data were collected from all informative loci. The average LOH frequency on 4p was 24.25%, and 42.3% and 35.62% on D4S405 and D4S3013 locus, respectively. Adjacent markers of D4S3013 displayed a low LOH frequency (< 30%) by detailed deletion mapping. Significant opposite difference was observed between LOH frequency and tumor diameter on D4S412 and D4S1546 locus (0% vs 16.67%, P = 0.041; 54.55% vs 11.11%, P = 0.034, respectively). On D4S403 locus, LOH was significantly associated with tumor gross pattern (11.11%, 0, 33.33%, P = 0.030). No relationship was detected on other loci compared with clinicopathologial features.CONCLUSION: By deletion mapping, two obvious high frequency LOH regions spanning D4S3013 (4p15.2) and D4S405 (4p14) locus are detected. Candidate TSG, which is involved in carcinogenesis and progression of sporadic colorectal carcinoma on chromosome 4p, may be located between D4S3017 and D4S2933 (about 1.7 cm).展开更多
In this research,a nanoscale DNA structure of analogic China map is created. The nanostructure of roughly 150 nm in diameter with a spatial resolution of 6 nm is purely constructed by folding DNA. The picture observed...In this research,a nanoscale DNA structure of analogic China map is created. The nanostructure of roughly 150 nm in diameter with a spatial resolution of 6 nm is purely constructed by folding DNA. The picture observed by atomic force microscopy (AFM) is almost identical with the de-signed shape. The DNA origami technology invented by Rothemund in 2006 is employed in the construc-tion of this shape,which has proved the capability of constructing almost any complicated shape enabled by DNA origami,and provides new bottom-up method for constructing nanostructures.展开更多
Microsporogenesis and male gametogenesis are essential for the alternating life cycle of flowering plants between diploid sporophyte and haploid gametophyte generations. Rice （Oryza sativa） is the world＇s major sta...Microsporogenesis and male gametogenesis are essential for the alternating life cycle of flowering plants between diploid sporophyte and haploid gametophyte generations. Rice （Oryza sativa） is the world＇s major staple food, and manipulation of pollen fertility is particularly important for the demands to increase rice grain yield. Towards a better understanding of the mechanisms controlling rice male reproductive development, we describe here the cytological changes of anther development through 14 stages, including cell division, differentiation and degeneration of somatic tissues consisting of four concentric cell layers surrounding and supporting reproductive cells as they form mature pollen grains through meiosis and mitosis. Furthermore, we compare the morphological difference of anthers and pollen grains in both monocot rice and eudicot Arabidopsis thaliana. Additionally, we describe the key genes identified to date critical for rice anther development and pollen formation.展开更多
Single-nucleotide polymorphisms （SNPs） of ADIPOQ, ADIPOR1, and ADIPOR2 have been associated with type 2 diabetes mellitus （T2DM）, but there are many conflicting results especially in Chinese populations. To invest...Single-nucleotide polymorphisms （SNPs） of ADIPOQ, ADIPOR1, and ADIPOR2 have been associated with type 2 diabetes mellitus （T2DM）, but there are many conflicting results especially in Chinese populations. To investigate the contribution of the adiponectin genes and their receptors to T2DM, a case-control study was performed and 11 SNPs ofADIPOQ, ADIPOR1, and ADIPOR2 were genotyped in 985 T2DM and 1,050 control subjects, rs 16861194 （-11426 A〉G） in the putative promoter of ADIPOQ was associated with T2DM （P = 0.007; OR = 1.29, 95% CI 1.08-1.55）. None of the other 10 SNPs were associated with T2DM in this study, although rs2241766 and rs1501299 were reported to be associated with T2DM in previous Chinese studies. There was also no significant difference found from the ADIPOQ haplotype analysis, which contains rs 16861194. In addition, we also assessed potential gene-gene interactions in three genes and no interactions were found. In conclusion, our results supported the ADIPOQ gene as a possible risk factor for type 2 diabetes in Han Chinese population.展开更多
Background The subthalamic nucleus （STN） is widely recognized as one of the most important and commonly targeted nuclei in stereotactic and functional neurosurgery. The success of STN surgery depends on accuracy in ...Background The subthalamic nucleus （STN） is widely recognized as one of the most important and commonly targeted nuclei in stereotactic and functional neurosurgery. The success of STN surgery depends on accuracy in target determination. Construction of a digitaiized atlas of STN based on stereotactic MRI will play an instrumental role in the accuracy of anatomical localization. The aim of this study was to investigate the three-dimensional （3D） target location of STN in stereotactic space and construct a digitalized atlas of STN to accomplish the visualization of the STN on stereotactic MRI, thus providing clinical guidance on the precise anatomical localization of STN. Methods One hundred and twenty healthy people volunteered to be scanned by 1.5 Tesla MRI scanning with 1-mm-thick slice in the standard stereotactic space between 2005 and 2006. One adult male was selected for 3D reconstruction of STN. The process of 3D reconstruction included identification, manual segmentation, extraction, conservation and reconstruction. Results There was a significant correlation between the coordinates and age （P 〈0.05）. The volume of left STN was significantly larger than the right STN, and there was a significant negative correlation between volume and age （P 〈0.05） The surface of the STN nucleus after 3D reconstruction appeared smooth, natural and realistic. The morphological feature of STN on the individual brain could be visualized directly in 3D. The 3D reconstructed STN could be rotated, zoomed and displayed at any direction in the stereotactic space. The anteroposterior diameter of the STN nucleus was longer than the vertical and transverse diameters in 3D space. The 3D reconstruction of STN manifested typical structure of the ＂dual lens＂. Conclusions The visualization of individual brain atlas based on stereotactic MRI is feasible. However, software for automated segmentation, extraction and registration of MR images need to be further developed.展开更多
At the time of implanting bone-related implants into human body,a variety of biological responses to the material surface occur with respect to surface chemistry and physical state.The commonly used biomaterials(e.g.t...At the time of implanting bone-related implants into human body,a variety of biological responses to the material surface occur with respect to surface chemistry and physical state.The commonly used biomaterials(e.g.titanium and its alloy,Co–Cr alloy,stainless steel,polyetheretherketone,ultra-high molecular weight polyethylene and various calcium phosphates)have many drawbacks such as lack of biocompatibility and improper mechanical properties.As surface modification is very promising technology to overcome such problems,a variety of surface modification techniques have been being investigated.This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating,radiation grafting,plasma surface engineering,ion beam processing and surface patterning techniques.The contents are organized with different types of techniques to applicable materials,and typical examples are also described.展开更多
基金This work was supported by the Major State Basic Research Development program of Chinathe National High Technology Research and Development Program of China.
文摘In multiloci-based genetic association studies of complex diseases, a powerful and high efficient tool for analyses oflinkage disequilibrium (LD) between markers, haplotype distributions and many chi-square/p values with a large numberof samples has been sought for long. In order to achieve the goal of obtaining meaningful results directly from raw data,we developed a robust and user-friendly software platform with a series of tools for analysis in association study withhigh efficiency. The platform has been well evaluated by several sets of real data.
基金Supplementary information is linked to the online version of the paper on the Cell Research website.Acknowledgments We thank Michel S6m6riva （IBDML, France）, Fumio Matsuzaki （RIKEN CDB, Japan）, Michael J Galko （UT MD Anderson Cancer Center, USA）, Enrique Martin-Blanco （Instituto de Biologia Molecular de Barcelona, Spain）, Dirk Bohmann （University of Rochester, USA）, Kyung-Ok Cho （Baylor College of Medicine, USA）, the Bloomington Drosophila Stock Center, NIGFLY （Japan）, and the Developmental Studies Hybridoma Bank for providing fly strains and antibodies. We also thank Wenjuan Xiang and Wentian Gu in ML＇s Lab for the technical assistance.This work was supported by National Natural Science Foundation of China （30470890）, National Basic Research Program of China （2007CB914504, 2007CB947301）, the Shanghai Pujiang Program （05PJ14075） and Shanghai Leading Academic Discipline Project （B205）.
文摘The Hedgehog （Hh） family of secreted signaling proteins plays a critical role in regulating the development of several tissues and organ systems. The ability of Hh proteins to exert their biological effects is regulated by a series of post-translational processes. These processes include an intramolecular cleavage, covalent addition of cholesterol and/or palmitate, and conversion into a multimeric freely diffusible form. The processing of Hh proteins affects their trafficking, potency, and ability to signal over several cell diameters. Here we review the current understanding of the Hh signaling mechanisms that govern the establishment of the Hh gradient and the transduction of the Hh signal in the light of recent data.
基金We gratefully acknowledge B Han from National Center for Gene Research, Chinese Academy of Sciences (CAS) and Rice Genome Resource Center (RGRC) for providing BAC clone, cDNA clone and Tosl7 insertion line. We thank Z-J Luo and M-J Chen from Shanghai Jiao Tong University for mutant screening and generation of F2 populations, X-Y Gao from Institute of Plant Physiology and Ecology, SIBS, CAS, for SEM, H Yu from Nation- al University Of Singapore for critical reading of this manuscript and H Ma from Fudan University for helpful discussion. This work was supported by funds from the National Basic Research Program of China (2009CB941500, 2006CB 101700), the National Natural Science Foundation of China (30725022, 30830014 and 90717109) and the Shanghai Leading Academic Discipline Project (B205).
文摘Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMADS6, in specifying floral organ and meristem identities in rice (Oryza sativa L.). OsMADS6 was strongly ex- pressed in the floral meristem at early stages. Subsequently, OsMADS6 transcripts were mainly detectable in paleas, lodicules, carpels and the integument of ovule, as well as in the receptacle. Compared to wild type plants, osmads6 mutants displayed altered palea identity, extra glume-like or mosaic organs, abnormal carpel development and loss of floral meristem determinacy. Strikingly, mutation of a SEPALLATA (SEP)-like gene, OsMADS1 (LHS1), enhanced the defect of osmads6 flowers, and no inner floral organs or glume-like structures were observed in whorls 2 and 3 of osmadsl-z osmads6-1 flowers. Furthermore, the osmadsl-z osmads6-1 double mutants developed severely indetermi- nate floral meristems. Our finding, therefore, suggests that the ancient OsMADS6 gene is able to specify "floral state" by determining floral organ and meristem identities in monocot crop rice together with OsMADS1.
基金the National Basic Research Program of China (973 Program) (No. 2007CB947301).
文摘Vertebrate digits are essential structures for movement, feeding and communication. Specialized regions of the developing limb bud including the zone of polarizing activity （ZPA）, the apical ectodermal ridge （AER）, and the non-ridge ectoderm regulate the patterning of digits. Although a series of signaling molecules have been characterized as patterning signals from the organizing centers, the delicate cellular and molecular mechanisms that interpret how these patterning signals control the detailed digit anatomy remain unclear, Recent studies from model organisms and human hand malformations provide new insights into the mechanisms regulating this process. Here, we review the current understanding of the genetic networks governing digit morphogenesis
文摘Objective Thyroid hormones(THs)regulate multiple physiological activities in the liver,including cellular metabolism,differentiation,and cell growth,and play important roles in the pathogenesis of hepatocellular carcinoma(HCC).Thyroid peroxidase(TPO)is a key molecule involved in the THs synthesis and signaling pathway.As an epigenetic modification,DNA methylation has a critical role in tumorigenesis with diagnostic potential.However,the connection between THs and DNA methylation has been rarely investigated.Methods The methylation of key TH-related genes was analyzed by in-house epigenome-wide scanning,and we further analyzed the methylation levels of the TPO promotor in 164 sample pairs of HCC and adjacent non-cancerous tissues by Sequenom EpiTYPER assays,and evaluated their clinical implications.Results We identified that the methylation of the TPO promoter was downregulated in the HCC tissues(P<0.0001)with a mean difference ranging from 18.5%to 22.3%.This methylation pattern correlated with several clinical factors,including a multi-satellite tumor,fibrous capsule,and the presence of tumor thrombus.The receiver operator characteristic(ROC)curve analysis further confirmed that the percent methylated reference(PMR)values for TPO were predictive of the tumor[the area under the curve(AUC)ranged from 0.755 to 0.818]and the thrombosis in the HCC patients(the AUC ranged from 0.706 to 0.777).Conclusion These findings demonstrated that epigenetic alterations of TPO,as indicated by the PMR values,were a potential biomarker for HCC patients with tumor thrombosis.
基金Supported by the Program for New Century Excellent in University of China(30740061)the National Natural Science Foundation of China(30672001)
文摘Objective To prepare and characterize polyelectrolyte multilayer film coated microbubbles for use as ultrasound contrast agent(UCA)and evaluate its effects in ultrasonic imaging on normal rabbit's liver parenchyma.Methods Perfluorocarbon(PFC)-containing microbubbles(ST68-PFC)were prepared by sonication based on surfactant(Span 60 and Tween 80).Subsequently,the resulting ST68-PFC microbubbles were coated using oppositely charged polyelectrolytes by microbubble-templated layer-by-layer self-assembly technique via electrostatic interaction.The enhancement effects in ultrasonic imaging on normal rabbit's liver parenchyma were assessed.Results The obtained microbubbles exhibited a narrow size distribution.The polyelectrolytes were successfully assembled onto the surface of ST68-PFC microbubbles.In vivo experiment showed that polyelectrolyte multilayer film coated UCA effectively enhanced the imaging of rabbit's liver parenchyma.Conclusions The novel microbubbles UCA coated with polyelectrolyte multilayer,when enabled more function,has no obvious difference in enhancement effects compared with the pre-modified microbubbles.The polymers with chemically active groups(such as amino group and carboxyl group)can be used as the outermost layer for attachment of targeting ligands onto microbubbles,allowing selective targeting of the microbubbles to combine with desired sites.
基金The National Natural Science Foundation of China, No. 30080016 and No. 30470977
文摘AIM: To search candidate tumor suppressor genes (TSGs) on chromosome 4q through detecting high loss of heterozygosity (LOH) regions in sporadic colorectal carcinoma in Chinese patients. METHODS: Thirteen fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by polymerase chain reaction (PCR). PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. Comparison between LOH frequency and clinicopathological factors were performed by χ2 test. RESULTS: Data were collected on all informative loci. The average LOH frequency on 4q was 28.56%. The D4S2915 locus showed highest LOH frequency (36.17%). Two obvious deletion regions were detected: one between D4S3000 and D4S2915 locus (4q12-21.1), another flanked by D4S407 and D4S2939 locus (4q25-31.1). None case showed complete deletion of 4q, most cases displayed interstitial deletion pattern solely. Furthermore, compared with clinicopathological features, a significant relationship was observed between LOH frequencies on D4S3018locus. In tumors larger than 5 cm in diameter, LOH frequency was significantly higher than tumors that were less than 5 cm (56% vs 13.79%, P = 0.01). On D4S1534 locus, LOH was significantly associated with liver metastasis (80% vs 17.25%, P = 0.012). No relationship was detected on other locus compared with clinicopathologial features. CONCLUSION: By high resolution deletion mapping, two high frequency regions of LOH (4q12-21.1 and 4q25-31.1) were detected, which may contribute to locate TSGs on chromosome 4q involved in carcinogenesis and progression of sporadic colorectal carcinoma.
基金Supported by The National Natural Science Foundation of China, No. 30080016 and No. 30470977
文摘AIM: To study the candidate tumor suppressor genes (TSG) on chromosome 4p by detecting the high frequency of loss of heterozygosity (LOH) in sporadic colorectal carcinoma in Chinese patients.METHODS: Seven fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by PCR. PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. The same procedure was performed by the other six microsatellite markers spanning D4S3013 locus to make further detailed deletion mapping. Comparison between LOH frequency and clinicopathological factors was performed by χ2 test.RESULTS: Data were collected from all informative loci. The average LOH frequency on 4p was 24.25%, and 42.3% and 35.62% on D4S405 and D4S3013 locus, respectively. Adjacent markers of D4S3013 displayed a low LOH frequency (< 30%) by detailed deletion mapping. Significant opposite difference was observed between LOH frequency and tumor diameter on D4S412 and D4S1546 locus (0% vs 16.67%, P = 0.041; 54.55% vs 11.11%, P = 0.034, respectively). On D4S403 locus, LOH was significantly associated with tumor gross pattern (11.11%, 0, 33.33%, P = 0.030). No relationship was detected on other loci compared with clinicopathologial features.CONCLUSION: By deletion mapping, two obvious high frequency LOH regions spanning D4S3013 (4p15.2) and D4S405 (4p14) locus are detected. Candidate TSG, which is involved in carcinogenesis and progression of sporadic colorectal carcinoma on chromosome 4p, may be located between D4S3017 and D4S2933 (about 1.7 cm).
文摘In this research,a nanoscale DNA structure of analogic China map is created. The nanostructure of roughly 150 nm in diameter with a spatial resolution of 6 nm is purely constructed by folding DNA. The picture observed by atomic force microscopy (AFM) is almost identical with the de-signed shape. The DNA origami technology invented by Rothemund in 2006 is employed in the construc-tion of this shape,which has proved the capability of constructing almost any complicated shape enabled by DNA origami,and provides new bottom-up method for constructing nanostructures.
基金supported by the funds from the National Basic Research Program of China(Nos.2009CB941500 and 2007CB108700)the National Natural Science Foundation of China(No.30725022)+1 种基金the Chinese Transgenic Project(No. 2009ZX08009-108B)the National 863 High-Tech Project (No.2011AA10A101)
文摘Microsporogenesis and male gametogenesis are essential for the alternating life cycle of flowering plants between diploid sporophyte and haploid gametophyte generations. Rice （Oryza sativa） is the world＇s major staple food, and manipulation of pollen fertility is particularly important for the demands to increase rice grain yield. Towards a better understanding of the mechanisms controlling rice male reproductive development, we describe here the cytological changes of anther development through 14 stages, including cell division, differentiation and degeneration of somatic tissues consisting of four concentric cell layers surrounding and supporting reproductive cells as they form mature pollen grains through meiosis and mitosis. Furthermore, we compare the morphological difference of anthers and pollen grains in both monocot rice and eudicot Arabidopsis thaliana. Additionally, we describe the key genes identified to date critical for rice anther development and pollen formation.
基金supported by the National Natural Science Foundation of ChinaNational Basic Research Pro-gram of China (973 Program)+5 种基金National High-tech R&D Program (863 Program)the Chinese Nutrition Soci-ety (No. 05015)the Dannon Institute, the Shanghai-Unilever Research and Development Fund (No. 06SU07007)the Shanghai Municipality Science & Tech-nology Commission (No. 05JC14090)the Shanghai Leading Academic Discipline Project (No. B205)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KSCX2-YW-R-01)
文摘Single-nucleotide polymorphisms （SNPs） of ADIPOQ, ADIPOR1, and ADIPOR2 have been associated with type 2 diabetes mellitus （T2DM）, but there are many conflicting results especially in Chinese populations. To investigate the contribution of the adiponectin genes and their receptors to T2DM, a case-control study was performed and 11 SNPs ofADIPOQ, ADIPOR1, and ADIPOR2 were genotyped in 985 T2DM and 1,050 control subjects, rs 16861194 （-11426 A〉G） in the putative promoter of ADIPOQ was associated with T2DM （P = 0.007; OR = 1.29, 95% CI 1.08-1.55）. None of the other 10 SNPs were associated with T2DM in this study, although rs2241766 and rs1501299 were reported to be associated with T2DM in previous Chinese studies. There was also no significant difference found from the ADIPOQ haplotype analysis, which contains rs 16861194. In addition, we also assessed potential gene-gene interactions in three genes and no interactions were found. In conclusion, our results supported the ADIPOQ gene as a possible risk factor for type 2 diabetes in Han Chinese population.
基金This study was supported by National Natural Science Foundation of China （No. 30770595） and Key Scientific and Technological Project in Heilongjiang Province （No. GB06C40302）.
文摘Background The subthalamic nucleus （STN） is widely recognized as one of the most important and commonly targeted nuclei in stereotactic and functional neurosurgery. The success of STN surgery depends on accuracy in target determination. Construction of a digitaiized atlas of STN based on stereotactic MRI will play an instrumental role in the accuracy of anatomical localization. The aim of this study was to investigate the three-dimensional （3D） target location of STN in stereotactic space and construct a digitalized atlas of STN to accomplish the visualization of the STN on stereotactic MRI, thus providing clinical guidance on the precise anatomical localization of STN. Methods One hundred and twenty healthy people volunteered to be scanned by 1.5 Tesla MRI scanning with 1-mm-thick slice in the standard stereotactic space between 2005 and 2006. One adult male was selected for 3D reconstruction of STN. The process of 3D reconstruction included identification, manual segmentation, extraction, conservation and reconstruction. Results There was a significant correlation between the coordinates and age （P 〈0.05）. The volume of left STN was significantly larger than the right STN, and there was a significant negative correlation between volume and age （P 〈0.05） The surface of the STN nucleus after 3D reconstruction appeared smooth, natural and realistic. The morphological feature of STN on the individual brain could be visualized directly in 3D. The 3D reconstructed STN could be rotated, zoomed and displayed at any direction in the stereotactic space. The anteroposterior diameter of the STN nucleus was longer than the vertical and transverse diameters in 3D space. The 3D reconstruction of STN manifested typical structure of the ＂dual lens＂. Conclusions The visualization of individual brain atlas based on stereotactic MRI is feasible. However, software for automated segmentation, extraction and registration of MR images need to be further developed.
基金This work was partly supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Korea(2012R1A1A2040717)the National Basic Research Program of China funded by the Ministry of Science and Technology(MOST)of China(2011CB606205)+1 种基金the National Science and Technology Supporting Program of China funded by the MOST of China(2012BAI17B02)the National Natural Science Fund funded by the National Natural Science Foundation of China(21371106).
文摘At the time of implanting bone-related implants into human body,a variety of biological responses to the material surface occur with respect to surface chemistry and physical state.The commonly used biomaterials(e.g.titanium and its alloy,Co–Cr alloy,stainless steel,polyetheretherketone,ultra-high molecular weight polyethylene and various calcium phosphates)have many drawbacks such as lack of biocompatibility and improper mechanical properties.As surface modification is very promising technology to overcome such problems,a variety of surface modification techniques have been being investigated.This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating,radiation grafting,plasma surface engineering,ion beam processing and surface patterning techniques.The contents are organized with different types of techniques to applicable materials,and typical examples are also described.
