Adipose-derived mesenchymal stem cells (ADSCs) can be largely and easily obtained from a wide range of sources. Moreover, they have self-renewal ability, multi-differentiation potential, and an important role in imm...Adipose-derived mesenchymal stem cells (ADSCs) can be largely and easily obtained from a wide range of sources. Moreover, they have self-renewal ability, multi-differentiation potential, and an important role in immune regulation. They can secrete a variety of cytokines to regulate the in vivo micro-environment. Therefore, ADSCs are the ideal seed ceils for stem ceils application. This paper reviews the location, isolation, surface markers, proliferation, differentiation and other biological characteristics of ADSCs, as well as their secretory function and relative researches. ADSCs are expected to become excellent seed cells for cell therapy and tissue engineering through in-depth studies.展开更多
The genus Stenochironomus from China,including 10 species,is reviewed.Three species,S.koreanus Borkent,S.maculatus Borkent,and S.totifuscus Sublette are re-described and recorded from China for the first time.One spec...The genus Stenochironomus from China,including 10 species,is reviewed.Three species,S.koreanus Borkent,S.maculatus Borkent,and S.totifuscus Sublette are re-described and recorded from China for the first time.One species misidentification is corrected.A key to the males of Stenochironomus in China is given.展开更多
Objective: To investigate the expression of Glypican-3 gene in (α-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) and clarify whether Glypican-3 expression is a useful parameter for the diagnosis of h...Objective: To investigate the expression of Glypican-3 gene in (α-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) and clarify whether Glypican-3 expression is a useful parameter for the diagnosis of hepatocelhllar carcinoma (HCC), especially for AFP-negative ones. Methods: Forty-one specimens of AFP-negative hepatocellular carcinoma and para-carcimoma tissue were studied for the expression of Glypican-3 by Northern blot. The expression of Glypican-3 protein was detected immunohistochemically with specific polyclonal antibody. Results: Northern blot analysis indicated that the expression of Glypican-3 mRNA was intensively detected in 30 of 41 AFP-negative HCC (73.17%). In contrast, Glypican-3 mRNA was only weakly detected in 4 of the surrounding non-tumor liver tissues. There was significant difference in the Glypican-3 mRNA expression in large tumors (〉5 cm) (79.31%) and in small tumors (〈5 cm) (41.67%) (P〈0.01). Gypican-3 mRNA was more frequently overexpressed in poorly differentiated HCC than in well differentiated ones (76.47% vs. 42.86%, P〈0.05). The Glypican-3 expression was not correlated with age. sex. ttbsAg seropositivity, fibroeapsule, portal venous embolus and intrahepatic metastasis. The overexpression of Glypican-3 protein in HCC was targeted in tumor cells, not in bile duct cells and other interstitial cells. Conclusion: Glypican-3 was specially overexpressed in AFP-negative HCC, and its expression was closely correlated with the tumor size and tumor grade. Glypican-3 gene may play important roles in hepatocareinogenesis, and can be used as a new biochemical marker of HCC, especially for AFP-negative HCC.展开更多
Ten species of Podagricomela Heikertinger from China are studied. They are Podagricomela apicipennis (Jacoby), P. cupera Wang, P. cyanea Chen, P. flavitibialis Wang, P. geminata Chen et Zia, P. nigricollis Chen, P. ni...Ten species of Podagricomela Heikertinger from China are studied. They are Podagricomela apicipennis (Jacoby), P. cupera Wang, P. cyanea Chen, P. flavitibialis Wang, P. geminata Chen et Zia, P. nigricollis Chen, P. nigripes Medvedev, P. parva Chen et Zia, P. shirahatai (Ch?j?), and P. weisei Heikertinger. Among them, P. nigripes Medvedev is recorded for the first time from China. A key to species from China is given. Illustrations of the male aedeagus and female spermatheca of each species are also given. The geographical distribution in China is analyzed briefly. The result indicates that Podagricomela mainly occurs in southern China, southwestern China, central China and north China, and the distribution center of this genus is in China. They always feed on Rutaceae.展开更多
[Objective] The aim was to establish the BHK-21 stable cell lines expressing T7 RNAP and GFP.[Method]T7 RNAP gene was amplified from E.coli BL21(DE3)and inserted into FG12 vector.The lenti-virus recombinant plasmid ...[Objective] The aim was to establish the BHK-21 stable cell lines expressing T7 RNAP and GFP.[Method]T7 RNAP gene was amplified from E.coli BL21(DE3)and inserted into FG12 vector.The lenti-virus recombinant plasmid FG12-T7 RNAP plasmid was obtained via identification with double enzymes digestion and gene sequencing.The transient expressed T7 RNAP protein was determined by WB in 293T cells transfected with FG12-T7 RNAP plasmid.The recombinant FG12-RNAP lenti-virus was packaged up by transfecting the 293 cells with the recombinant vector FG12-RNAP and the helper plasmids via lipofectamine-2000,which was then used to infect BHK-21 cells.The positive cell clones were obtained after continuous screening by GFP.The expression of T7 RNAP gene was confirmed by Western blot.[Result]The cell line stably expressing the T7 RNAP gene was established by Western blot.[Conclusion]T7 RNAP gene could be stably expressed in eukaryotic cells and it provided a good platform to rescue RNA virus in vivo.展开更多
Epidamaeus variabilis Fujikawa & Fujita, 1985 and Epidamaeus mongolicus Bayartogtokh, 2000 are reported, with redescription, for the first time in China.
The effect of heat treatment on the transformation temperature of Ti?52.2%Ni (mole fraction) alloy was studied using differential scanning calorimetry (DSC). The transformation temperatures of the alloy can be adjuste...The effect of heat treatment on the transformation temperature of Ti?52.2%Ni (mole fraction) alloy was studied using differential scanning calorimetry (DSC). The transformation temperatures of the alloy can be adjusted effectively by heat treatment. Dense and stable SiO2 coatings were deposited on the surface of the pre-oxidized TiNi alloy by sol?gel method. The bonding strength of films and matrix was (65.9±1.5) N. The electrochemical corrosion test shows that the TiNi alloy with SiO2 coating has excellent corrosion resistance in the Hank’s simulated body fluid. The release behaviors of Ni ion of the alloy with and without SiO2 coating implanted in the acoustic vesicle of guinea pig were studied by EDS testing, which was inhibited effectively by the dense and stable SiO2 coating on the alloy.展开更多
Pomponia orientalis (Distant, 1912) is reported for the first time from China based on specimens collected from Yunnan Province. The morphological redescription and male genitalia of this species are provided. A key...Pomponia orientalis (Distant, 1912) is reported for the first time from China based on specimens collected from Yunnan Province. The morphological redescription and male genitalia of this species are provided. A key to the species of Pomponia from China is given. Geographical distribution of Chinese species of Pompon ia is discussed.展开更多
Functional analysis of control genes is playing an important role in animal development.The research is mainly focused on developing a method of estimating the gene's effect or function in the development of anima...Functional analysis of control genes is playing an important role in animal development.The research is mainly focused on developing a method of estimating the gene's effect or function in the development of animals.In this article,the gene's expression and control are described by models of quantitative genetics,which include the genetic models about the genes with no interaction and interaction effect.On this basis,a method analyzing the functions of control genes in batches is advanced,the method includes three steps as follows: Firstly,describe the gene's expression and control with multiple regression models in statistic method in different conditions.Secondly,collect the material of gene's polymorphism related to the gene's expression and control.Because,gene's polymorphism or the codominant molecular marker electropherogram in a gene locus present 3 states,and can be expressed with -1,0 and 1 respectively.The author thinks it can be regarded as levels in orthogonal layout.Discard the materials of gene's polymorphism not fitting the orthogonal layout,and use the materials of gene's polymorphism fitting the orthogonal layout as the data to estimate the gene's effects.Thirdly,analyze the gene's effect or function with equations as follows:suppose that a quantitative trait is controlled by N gene loci,in each locus there are two alleles,the alleles' effects are A GM1 ?a GM1 ;A GM2 ? a GM2 ;...;A GMi ?a GMi ;...;A GMN ;a GMN units respectively.When the genotype in a locus is heterozygous A GMi a GMi ,the interaction coefficient of alleles in a locus is K units.If there is no interaction among different gene loci,the author thinks,the gene's effects and gene's type can be estimated by using such equation: P GM =2∑Ni=1(A i-a i+K i)+∑Ni=1(A i-a i)M GMi -∑Ni=1K GMi M GMi 2 If there are interactions among different gene loci,and the effect of the x th gene's state combined with the y th gene's state in the k th gene group is defined as Y xyr ,and let gene group electropherogram states be r (where r∈ ),the author thinks,the gene group's effects can be estimated by the equation: Y xyr = K PCxy0 +K PCxy r+K PCxy' r 2+K PCxy'' 3+K PCxy(3') r 4+K PCxy(4') r 5+K PCxy(5') r 6+K PCxy(6') r 7+K PCxy(7') r 8 If there are interactions among more genes,the analogous method can also be used. In this way,be using the gene's codominent marker materials fitting the orthogonal layout,the gene's expression and control can be researched by the method of multiple regression,the gene's relative effect can be estimated,the overdominant gene's overdominant coefficient can be assessed,the gene's type can be identified,the interaction gene group's relative effect and the interaction gene's relation can be estimated as well,and furthermore,the gene's relation can be expressed in equations.For the sake of understanding the method used in this paper,the rout to prove it is given as well.Finally,the author thinks,this method is very useful to research the gene's function in molecular developmental biology.展开更多
G-enomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and mammal genomes and plays an essential role in mammalian development and growth. There are a number of genes ...G-enomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and mammal genomes and plays an essential role in mammalian development and growth. There are a number of genes in our genomes that are subject to genomic imprinting where one parent's copy of the gene is expressed while the other is silent. Silencing of one allele predetermines that any function ascribed to that gene are now dependant on the single active copy. Possession of only a single active allele can lead to deleterious health consequences in humans. If imprinted genes are crucial in mammalian development, one would also expect mutations in these genes to cause diseases. Since imprinting is an epigenetic mechanism, mistakes in maintaining epigenetic mark also cause imprinting disorders. Here we in this review focus on the current understanding of this unique genetic mechanism more than two decades after the first description of the imprinting phenomenon was given by McGrath and Solter. Although the possible molecular mechanisms by which imprinting is imposed and maintained are being identified, we have a long way to go in understanding the molecular mechanisms that regulate the expression of these oddly behaving genes, the function of imprinting and the evolution. Post genomic technologies might ultimately lead to a better understanding of the 'imprinting effects'.展开更多
AIM: TO elucidate the prognostic role and relationship of three molecular markers such as tumor suppressor gene p53, proliferating cell nuclear antigen (PCNA) and Ki-67 in gastric stromal tumor. METHODS: A total o...AIM: TO elucidate the prognostic role and relationship of three molecular markers such as tumor suppressor gene p53, proliferating cell nuclear antigen (PCNA) and Ki-67 in gastric stromal tumor. METHODS: A total of 108 surgically resected gastric smooth muscle tumor specimens were collected from January 1987 to December 1999. Immunohistochemical studies were performed on the paraffin sections of 99 of 108 CDl17-positive tumors with antibodies of p53, PCNA, and Ki-67. Immunoreactivity of three molecular markers was recorded by labeling index (LI, %) and was analyzed for clinicopathologic and survival correlation. RESULTS: Of the 99 cases, immunostaining revealed that 52 patients (52.5%) had p53, and 37 patients (37.3%) had Ki-67 immunoreactivity (defined as 〉10% of LI). All patients (100%) had PCNA immunoreactivity ranging from 12% to 93% of LI, divided into high or low by median. Statistics revealed that LI of three markers positively correlate to each other (P〈0.01) and to microscopic tumor mitotic counts (P〈0.001). By combination, patients with ≥2 markers (positive or high) in tumors had early tumor recurrence (P〈0.001) and unfavorable outcome (P〈0.001). Univariate analysis indicated that patients with tumor size 〉5 cm (P=0.003), tumor mitosis 〉5/50 HPF (P〈0.001), p53 immunoreactivity (P=0.001), Ki-67 immunoreactivity (P=0.026), high PCNA LI (P=0.015) and male gender (P=0.036) were six predictors for early disease recurrence. Subsequent multivariate analysis revealed that mitotic counts, tumor size, and p53 immunoreactivity were three independent prognostic factors for both disease free and overall survival of patients. By combination of three independent prognostic factors for grouping, we found higher tumor recurrence rate (P〈0.001) and shorter survival (P〈0.001) existed in groups with increasing factors. CONCLUSION: We first provide the prognostic value and linkage of three molecular markers in GISTs. The combination of three factors (p53, tumor size, and tumor mitosis) provides a more powerful prediction of prognosis than any single factor does.展开更多
Chronic viral infections such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are major global health problems affecting more than 500 million people worldwide. Virus-specifi...Chronic viral infections such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are major global health problems affecting more than 500 million people worldwide. Virus-specific CD8+ T cells play an important role in the course and outcome of these viral infections and it is hypothesized that altered or impaired differentiation of virus- specific CD8+ T cells contributes to the development of persistence and/or disease progression. A deeper understanding of the mechanisms responsible for functional differentiation of CD8+ T cells is essential for the generation of successful therapies aiming to strengthen the adaptive component of the immune system.展开更多
Littoral-cell angioma(LCA), a primary angioma which clinically belongs to splenic hemangioma, can be mostly found in normal spleen red sinus shore cells of reticuloendothelial cell system. The cells of LCA strongly ex...Littoral-cell angioma(LCA), a primary angioma which clinically belongs to splenic hemangioma, can be mostly found in normal spleen red sinus shore cells of reticuloendothelial cell system. The cells of LCA strongly express endothelial and tissue cell associated antigens that indicate a dual differentiation characteristic; whereas only endothelial cell markers are positive in normal spleen red sinus shore cells. Diagnosis of LCA relies on histopathology. Regular follow-up is needed to monitor recurrence and metastasis.展开更多
The preparation of TiO2/poly(L-lactide-co-ε-caprolactone)(PLCL) nanocomposites and their properties were reported.TiO2nanoparticles were surface modified by ring-opening polymerization of ε-caprolactone(ε-CL)...The preparation of TiO2/poly(L-lactide-co-ε-caprolactone)(PLCL) nanocomposites and their properties were reported.TiO2nanoparticles were surface modified by ring-opening polymerization of ε-caprolactone(ε-CL).The resulting poly(ε-caprolactone)-grafted TiO2(g-TiO2) was characterized by Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA) and transmission electron microscopy(TEM).The g-TiO2can be uniformly dispersed in chloroform and the g-TiO2/PLCL nanocomposites were successfully fabricated through solvent-casting method.The effects of the content of g-TiO2nanoparticles on tensile properties and shape memory properties were investigated.A significant improvement in the tensile properties of the 5% g-TiO2/PLCL mass fraction nanocomposite is obtained:an increase of 113% in the tensile strength and an increase of 11% in the elongation at break over pure PLCL polymer.The g-TiO2/PLCL nanocomposites with a certain amount of g-TiO2content have better shape memory properties than pure PLCL polymer.The g-TiO2nanoparticles play an additional physical crosslinks which are contributed to improvement of the shape memory properties.展开更多
This paper submits that the advantages gained by introducing a single currency at the domestic level, applies equally to the economy at the global level. The advantages gained are (1) a reduction of the inflation ra...This paper submits that the advantages gained by introducing a single currency at the domestic level, applies equally to the economy at the global level. The advantages gained are (1) a reduction of the inflation rate to one common rate (if required) amongst all states, (2) a possible reduced interest rate, (3) an expansion in investment, (4) an increase in development and trade due to the removal of uncertainty, (5) the reduction in transaction costs, and (6) the reduction in the cost of capital (Moshirian, 2004, p. 306). A single global currency has immediate implications in accounting for inflation as it presents an opportunity for the permanent removal of problems associated with accounting for inflation. This paper addresses the phenomenon of inflation and how accounting measurement and valuation associated with inflation is removed by the introduction of a single global currency.展开更多
基金Supported by The Fund from the Endangered Species Import and Export Management Office of the People’s Republic of China for the Management and Research of Endangered Wild Animals(201441314404)~~
文摘Adipose-derived mesenchymal stem cells (ADSCs) can be largely and easily obtained from a wide range of sources. Moreover, they have self-renewal ability, multi-differentiation potential, and an important role in immune regulation. They can secrete a variety of cytokines to regulate the in vivo micro-environment. Therefore, ADSCs are the ideal seed ceils for stem ceils application. This paper reviews the location, isolation, surface markers, proliferation, differentiation and other biological characteristics of ADSCs, as well as their secretory function and relative researches. ADSCs are expected to become excellent seed cells for cell therapy and tissue engineering through in-depth studies.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (Y3100486)the National Natural Science Foundation of China (30570207, J0630963)Fauna of China (FY120100)
文摘The genus Stenochironomus from China,including 10 species,is reviewed.Three species,S.koreanus Borkent,S.maculatus Borkent,and S.totifuscus Sublette are re-described and recorded from China for the first time.One species misidentification is corrected.A key to the males of Stenochironomus in China is given.
基金This work was supported in part by grants from the State Key Basic Research Program (No.39825114) and the NationalNatural Science Foundation of China (No.39770379).
文摘Objective: To investigate the expression of Glypican-3 gene in (α-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) and clarify whether Glypican-3 expression is a useful parameter for the diagnosis of hepatocelhllar carcinoma (HCC), especially for AFP-negative ones. Methods: Forty-one specimens of AFP-negative hepatocellular carcinoma and para-carcimoma tissue were studied for the expression of Glypican-3 by Northern blot. The expression of Glypican-3 protein was detected immunohistochemically with specific polyclonal antibody. Results: Northern blot analysis indicated that the expression of Glypican-3 mRNA was intensively detected in 30 of 41 AFP-negative HCC (73.17%). In contrast, Glypican-3 mRNA was only weakly detected in 4 of the surrounding non-tumor liver tissues. There was significant difference in the Glypican-3 mRNA expression in large tumors (〉5 cm) (79.31%) and in small tumors (〈5 cm) (41.67%) (P〈0.01). Gypican-3 mRNA was more frequently overexpressed in poorly differentiated HCC than in well differentiated ones (76.47% vs. 42.86%, P〈0.05). The Glypican-3 expression was not correlated with age. sex. ttbsAg seropositivity, fibroeapsule, portal venous embolus and intrahepatic metastasis. The overexpression of Glypican-3 protein in HCC was targeted in tumor cells, not in bile duct cells and other interstitial cells. Conclusion: Glypican-3 was specially overexpressed in AFP-negative HCC, and its expression was closely correlated with the tumor size and tumor grade. Glypican-3 gene may play important roles in hepatocareinogenesis, and can be used as a new biochemical marker of HCC, especially for AFP-negative HCC.
文摘Ten species of Podagricomela Heikertinger from China are studied. They are Podagricomela apicipennis (Jacoby), P. cupera Wang, P. cyanea Chen, P. flavitibialis Wang, P. geminata Chen et Zia, P. nigricollis Chen, P. nigripes Medvedev, P. parva Chen et Zia, P. shirahatai (Ch?j?), and P. weisei Heikertinger. Among them, P. nigripes Medvedev is recorded for the first time from China. A key to species from China is given. Illustrations of the male aedeagus and female spermatheca of each species are also given. The geographical distribution in China is analyzed briefly. The result indicates that Podagricomela mainly occurs in southern China, southwestern China, central China and north China, and the distribution center of this genus is in China. They always feed on Rutaceae.
基金Supported by National Transgenic Major Program of China(2009ZX08007-006B)the National Natural Science Foundation of China(31072160)+2 种基金Science and Technique Foundation of Shandong Province(2009GG20002032)Natural Science Foundation of Shandong Province(Y2008D20)an Open Issue of State Key Laboratory of Veterinary Biotechnology Fund(SKLVBF200806)~~
文摘[Objective] The aim was to establish the BHK-21 stable cell lines expressing T7 RNAP and GFP.[Method]T7 RNAP gene was amplified from E.coli BL21(DE3)and inserted into FG12 vector.The lenti-virus recombinant plasmid FG12-T7 RNAP plasmid was obtained via identification with double enzymes digestion and gene sequencing.The transient expressed T7 RNAP protein was determined by WB in 293T cells transfected with FG12-T7 RNAP plasmid.The recombinant FG12-RNAP lenti-virus was packaged up by transfecting the 293 cells with the recombinant vector FG12-RNAP and the helper plasmids via lipofectamine-2000,which was then used to infect BHK-21 cells.The positive cell clones were obtained after continuous screening by GFP.The expression of T7 RNAP gene was confirmed by Western blot.[Result]The cell line stably expressing the T7 RNAP gene was established by Western blot.[Conclusion]T7 RNAP gene could be stably expressed in eukaryotic cells and it provided a good platform to rescue RNA virus in vivo.
文摘Epidamaeus variabilis Fujikawa & Fujita, 1985 and Epidamaeus mongolicus Bayartogtokh, 2000 are reported, with redescription, for the first time in China.
基金Project(81170609)supported by the National Natural Science Foundation of ChinaProject(11JJ6087)supported by the Nature Science Foundation of Hunan Province,ChinaProject supported by the Open Project of State Key Laboratory of Powder Metallurgy,Central South University,China
文摘The effect of heat treatment on the transformation temperature of Ti?52.2%Ni (mole fraction) alloy was studied using differential scanning calorimetry (DSC). The transformation temperatures of the alloy can be adjusted effectively by heat treatment. Dense and stable SiO2 coatings were deposited on the surface of the pre-oxidized TiNi alloy by sol?gel method. The bonding strength of films and matrix was (65.9±1.5) N. The electrochemical corrosion test shows that the TiNi alloy with SiO2 coating has excellent corrosion resistance in the Hank’s simulated body fluid. The release behaviors of Ni ion of the alloy with and without SiO2 coating implanted in the acoustic vesicle of guinea pig were studied by EDS testing, which was inhibited effectively by the dense and stable SiO2 coating on the alloy.
基金supported by the National Natural Science Foundation of China(31170360,31093430,31493021)
文摘Pomponia orientalis (Distant, 1912) is reported for the first time from China based on specimens collected from Yunnan Province. The morphological redescription and male genitalia of this species are provided. A key to the species of Pomponia from China is given. Geographical distribution of Chinese species of Pompon ia is discussed.
文摘Functional analysis of control genes is playing an important role in animal development.The research is mainly focused on developing a method of estimating the gene's effect or function in the development of animals.In this article,the gene's expression and control are described by models of quantitative genetics,which include the genetic models about the genes with no interaction and interaction effect.On this basis,a method analyzing the functions of control genes in batches is advanced,the method includes three steps as follows: Firstly,describe the gene's expression and control with multiple regression models in statistic method in different conditions.Secondly,collect the material of gene's polymorphism related to the gene's expression and control.Because,gene's polymorphism or the codominant molecular marker electropherogram in a gene locus present 3 states,and can be expressed with -1,0 and 1 respectively.The author thinks it can be regarded as levels in orthogonal layout.Discard the materials of gene's polymorphism not fitting the orthogonal layout,and use the materials of gene's polymorphism fitting the orthogonal layout as the data to estimate the gene's effects.Thirdly,analyze the gene's effect or function with equations as follows:suppose that a quantitative trait is controlled by N gene loci,in each locus there are two alleles,the alleles' effects are A GM1 ?a GM1 ;A GM2 ? a GM2 ;...;A GMi ?a GMi ;...;A GMN ;a GMN units respectively.When the genotype in a locus is heterozygous A GMi a GMi ,the interaction coefficient of alleles in a locus is K units.If there is no interaction among different gene loci,the author thinks,the gene's effects and gene's type can be estimated by using such equation: P GM =2∑Ni=1(A i-a i+K i)+∑Ni=1(A i-a i)M GMi -∑Ni=1K GMi M GMi 2 If there are interactions among different gene loci,and the effect of the x th gene's state combined with the y th gene's state in the k th gene group is defined as Y xyr ,and let gene group electropherogram states be r (where r∈ ),the author thinks,the gene group's effects can be estimated by the equation: Y xyr = K PCxy0 +K PCxy r+K PCxy' r 2+K PCxy'' 3+K PCxy(3') r 4+K PCxy(4') r 5+K PCxy(5') r 6+K PCxy(6') r 7+K PCxy(7') r 8 If there are interactions among more genes,the analogous method can also be used. In this way,be using the gene's codominent marker materials fitting the orthogonal layout,the gene's expression and control can be researched by the method of multiple regression,the gene's relative effect can be estimated,the overdominant gene's overdominant coefficient can be assessed,the gene's type can be identified,the interaction gene group's relative effect and the interaction gene's relation can be estimated as well,and furthermore,the gene's relation can be expressed in equations.For the sake of understanding the method used in this paper,the rout to prove it is given as well.Finally,the author thinks,this method is very useful to research the gene's function in molecular developmental biology.
文摘G-enomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and mammal genomes and plays an essential role in mammalian development and growth. There are a number of genes in our genomes that are subject to genomic imprinting where one parent's copy of the gene is expressed while the other is silent. Silencing of one allele predetermines that any function ascribed to that gene are now dependant on the single active copy. Possession of only a single active allele can lead to deleterious health consequences in humans. If imprinted genes are crucial in mammalian development, one would also expect mutations in these genes to cause diseases. Since imprinting is an epigenetic mechanism, mistakes in maintaining epigenetic mark also cause imprinting disorders. Here we in this review focus on the current understanding of this unique genetic mechanism more than two decades after the first description of the imprinting phenomenon was given by McGrath and Solter. Although the possible molecular mechanisms by which imprinting is imposed and maintained are being identified, we have a long way to go in understanding the molecular mechanisms that regulate the expression of these oddly behaving genes, the function of imprinting and the evolution. Post genomic technologies might ultimately lead to a better understanding of the 'imprinting effects'.
基金Supported by the grant from the National Science Council of Taiwan,No,91-2314-B-182A-143-Co-first-authors:Tsung-Hui Hu and Seng-Kee Chuah
文摘AIM: TO elucidate the prognostic role and relationship of three molecular markers such as tumor suppressor gene p53, proliferating cell nuclear antigen (PCNA) and Ki-67 in gastric stromal tumor. METHODS: A total of 108 surgically resected gastric smooth muscle tumor specimens were collected from January 1987 to December 1999. Immunohistochemical studies were performed on the paraffin sections of 99 of 108 CDl17-positive tumors with antibodies of p53, PCNA, and Ki-67. Immunoreactivity of three molecular markers was recorded by labeling index (LI, %) and was analyzed for clinicopathologic and survival correlation. RESULTS: Of the 99 cases, immunostaining revealed that 52 patients (52.5%) had p53, and 37 patients (37.3%) had Ki-67 immunoreactivity (defined as 〉10% of LI). All patients (100%) had PCNA immunoreactivity ranging from 12% to 93% of LI, divided into high or low by median. Statistics revealed that LI of three markers positively correlate to each other (P〈0.01) and to microscopic tumor mitotic counts (P〈0.001). By combination, patients with ≥2 markers (positive or high) in tumors had early tumor recurrence (P〈0.001) and unfavorable outcome (P〈0.001). Univariate analysis indicated that patients with tumor size 〉5 cm (P=0.003), tumor mitosis 〉5/50 HPF (P〈0.001), p53 immunoreactivity (P=0.001), Ki-67 immunoreactivity (P=0.026), high PCNA LI (P=0.015) and male gender (P=0.036) were six predictors for early disease recurrence. Subsequent multivariate analysis revealed that mitotic counts, tumor size, and p53 immunoreactivity were three independent prognostic factors for both disease free and overall survival of patients. By combination of three independent prognostic factors for grouping, we found higher tumor recurrence rate (P〈0.001) and shorter survival (P〈0.001) existed in groups with increasing factors. CONCLUSION: We first provide the prognostic value and linkage of three molecular markers in GISTs. The combination of three factors (p53, tumor size, and tumor mitosis) provides a more powerful prediction of prognosis than any single factor does.
基金NIH National Center for Research Resources K12 RR017643 and NIH K08 AI072191 (HR)the National Institutes of Health through the Grand Challenges in Global Health Initiative, Cancer Research Institute Investigator Award, Woodruff Health Sciences Fund, Yerkes Research Center Base Grant RR-00165 and NIH AI070101 (AG)
文摘Chronic viral infections such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) are major global health problems affecting more than 500 million people worldwide. Virus-specific CD8+ T cells play an important role in the course and outcome of these viral infections and it is hypothesized that altered or impaired differentiation of virus- specific CD8+ T cells contributes to the development of persistence and/or disease progression. A deeper understanding of the mechanisms responsible for functional differentiation of CD8+ T cells is essential for the generation of successful therapies aiming to strengthen the adaptive component of the immune system.
文摘Littoral-cell angioma(LCA), a primary angioma which clinically belongs to splenic hemangioma, can be mostly found in normal spleen red sinus shore cells of reticuloendothelial cell system. The cells of LCA strongly express endothelial and tissue cell associated antigens that indicate a dual differentiation characteristic; whereas only endothelial cell markers are positive in normal spleen red sinus shore cells. Diagnosis of LCA relies on histopathology. Regular follow-up is needed to monitor recurrence and metastasis.
基金Project(50903023) supported by the National Natural Science Foundation of ChinaProject(HEUCF201210005) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2010RFQXG037) supported by Harbin Special Fund for Innovation Talents of Science and Technology,China
文摘The preparation of TiO2/poly(L-lactide-co-ε-caprolactone)(PLCL) nanocomposites and their properties were reported.TiO2nanoparticles were surface modified by ring-opening polymerization of ε-caprolactone(ε-CL).The resulting poly(ε-caprolactone)-grafted TiO2(g-TiO2) was characterized by Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA) and transmission electron microscopy(TEM).The g-TiO2can be uniformly dispersed in chloroform and the g-TiO2/PLCL nanocomposites were successfully fabricated through solvent-casting method.The effects of the content of g-TiO2nanoparticles on tensile properties and shape memory properties were investigated.A significant improvement in the tensile properties of the 5% g-TiO2/PLCL mass fraction nanocomposite is obtained:an increase of 113% in the tensile strength and an increase of 11% in the elongation at break over pure PLCL polymer.The g-TiO2/PLCL nanocomposites with a certain amount of g-TiO2content have better shape memory properties than pure PLCL polymer.The g-TiO2nanoparticles play an additional physical crosslinks which are contributed to improvement of the shape memory properties.
文摘This paper submits that the advantages gained by introducing a single currency at the domestic level, applies equally to the economy at the global level. The advantages gained are (1) a reduction of the inflation rate to one common rate (if required) amongst all states, (2) a possible reduced interest rate, (3) an expansion in investment, (4) an increase in development and trade due to the removal of uncertainty, (5) the reduction in transaction costs, and (6) the reduction in the cost of capital (Moshirian, 2004, p. 306). A single global currency has immediate implications in accounting for inflation as it presents an opportunity for the permanent removal of problems associated with accounting for inflation. This paper addresses the phenomenon of inflation and how accounting measurement and valuation associated with inflation is removed by the introduction of a single global currency.