Ultrastructural changes in the sieve element and dense cells of nectariferous tissue during the development of floral nectary in Arabidopsis thaliana L. were investigated with transmission electron microscopy. Samples...Ultrastructural changes in the sieve element and dense cells of nectariferous tissue during the development of floral nectary in Arabidopsis thaliana L. were investigated with transmission electron microscopy. Samples were prepared with high pressure freezing and freeze substitution techniques. The ultrastructure of dense cell was similar to that of sieve element at its early developmental stage. With the concurrent agglutination of chromatin in the nucleus, the abnormal location of organelles and the high density of cytoplasm, the ultrastructural characteristics in die dense cells of the nectariferous tissue and in the sieve element are matched with those of the programmed cell death in animal and plant reported in recent years. The disorganization of nucleus and most organelles in the differentiation of sieve elements and dense cells is closely associated with the transportation and modification of pre-nectar and the transference of nectar. This suggests that the cytological changes in sieve element and nectariferous tissue are closely associated with the nectary functional activities.展开更多
Coix has a long cultivation history as a minor crop in China, but many problems including unclear origin, chaos of species, loss and inaccurate use of germplasm resources exist in its research and production due to th...Coix has a long cultivation history as a minor crop in China, but many problems including unclear origin, chaos of species, loss and inaccurate use of germplasm resources exist in its research and production due to the lack of systematic study. In recent years, the importance of Coix has been realized with the exploration of its effects in treating and preventing cancer. The systematic study of Coix has met a superb development opportunity with the rapid development of biotechnology especially the deep-sequencing technique. Therefore, this paper presented here the current status of origin and evolution, classification, cytology and molecular biology progress of Coix, analyzed the ploidy of Coix and the genetic relationships with Zea, Sorghum and so on from the point of cytology, and then based on the molecular biology, analyzed the important significance of DNA molecular marker, genetic mapping and gene library in the research on identification of genetic relationship between species and genetic breeding, which could provide useful information for further Coix research.展开更多
Changes in distribution density,morphology and secretory content of endocrine cells in the gastro-entero-pancreatic system of black-spotted frogs Rana nigromaculata before and after fasting were investigated using imm...Changes in distribution density,morphology and secretory content of endocrine cells in the gastro-entero-pancreatic system of black-spotted frogs Rana nigromaculata before and after fasting were investigated using immunohistochemistry and antisera to six gut hormones.Six types of endocrine cells were detected in the digestive tract of Rana nigromaculata,including 5-hydroxytryptamine(5-HT),gastrin(GAS),somatostatin(SOM),glucagon(GLU),pancreatic polypeptide(PP)and vasoactive intestinal polypeptide(VIP)cells.After fasting,the density of 5-HT cells in the esophagus,cardia and fundus,GAS cells in the fundus and pylorus,PP cells in the fundus decreased significantly(P<0.01),while SOM cells in the cardia,GLU cells in the rectum increased significantly(P<0.01).The cytoplasmic processes of 5-HT cells became shorter or not detectable.The secretory content of GAS cells reduced in the cardia.The positive immunostaining reaction in the perinuclear region of SOM cells in the cardia,fundus and pylorus became weaker,while the staining intensity in the periphery of these cells became stronger.VIP cells were not detectable in the whole digestive tract after fasting.Five types of endocrine cells were found in the pancreas of Rana nigromaculata,including 5-HT,GAS,SOM,GLU and PP cells.After fasting,the density of 5-HT cells decreased slightly(P>0.05),while SOM,GAS,GLU and PP cells increased significantly(P<0.01).Furthermore,the secretory content of GLU cells increased significantly.Considering their functionalities,our results indicate that the changes of GEP endocrine cells in Rana nigromaculata responded adaptively to starvation-induced stress.展开更多
We have examined the myogenic potential of human embryonic stem （hES） cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult envir...We have examined the myogenic potential of human embryonic stem （hES） cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult environment and give rise to a range of cell types in the myogenic lineage. This study provides direct evidences that hES cells can regenerate both muscle and satellite cells in vivo and are another promising cell type for treating muscle degenerative disorders in addition to other myogenic cell types.展开更多
AIM： To explore the expansion and differentiation of hepatocytoid cell induced from myeloid mesenchymal stem cell （MSC） in vib＇o, in order to find suitable resource of hepatocytes for bioartiflcial liver or liver ...AIM： To explore the expansion and differentiation of hepatocytoid cell induced from myeloid mesenchymal stem cell （MSC） in vib＇o, in order to find suitable resource of hepatocytes for bioartiflcial liver or liver transplantation. METHODS： The rat myeloid MSC was isolated and divided into three groups which were cultured by Friedensteion method, and then were induced by culture fluid, culture fluid plus cholestatic serum and culture fluid plus hepatocyte growth factor （HGF）, respectively. Hepatocytoid cell as well as expression of CK18 and AFP was observed by immunohistochemistry. RESULTS： After the induction for 21 d, hepatocytoid cell was observed, and its expression of CK18 and AFP was detected by immunohistochemistry in MSC cultured with cholestatic serum. Furthermore, on the 35^th d, albumin mRNA was expressed in the cell, suggesting the inducing effect was similar to that by HGF.CONCLUSION： Rat myeloid MSC can differentiate into hepatocyte lineage under appropriate condition. This method is easy to operate.展开更多
Human embryonic stem cells （hESC） not only hold great promise for the treatment of degenerative diseases but also provide a valuable tool for developmental studies. However, the clinical applications of hESC are at ...Human embryonic stem cells （hESC） not only hold great promise for the treatment of degenerative diseases but also provide a valuable tool for developmental studies. However, the clinical applications of hESC are at present limited by xeno-contamination during the in vitro derivation and propagation of these cells. In this review, we summarize the current methodologies for the derivation and the propagation of hESC in conditions that will eventually enable the generation of clinical-grade cells for future therapeutic applications.展开更多
Objective: The aim of the study was to explore the protein level of NF-κB change in carcinoma and different grades of tumor cells differentiation tissue in colorectal cancer patients. Methods: This was a comparative ...Objective: The aim of the study was to explore the protein level of NF-κB change in carcinoma and different grades of tumor cells differentiation tissue in colorectal cancer patients. Methods: This was a comparative study between normal and carcinoma tissues and in different grades of tumor cells differentiation tissue in colorectal cancer patients. Ex-pression of NF-κΒ were assessed by immunohistochemical method using rabbit polyclonal antibodies against human p65 NF-κΒ proteins. Results: There was none or very little expression of NF-κB in non-neoplastic colon epithelial cells, while the expression of it's protein was significantly increased (P < 0.01) in adjacent cancerous cells. Moreover, there was a significant increase in the mean expression of NF-κB-p65 between poorly differentiated malignant epithelial cell and well-differentiated cells (P < 0.05). Conclusion: NF-κB-p65 may play an essential role in colorectal carcinogenesis and may be valuable for diagnosis, evaluating malignancy extent and prognosis.展开更多
To evaluate the efficacy and safety of gemcitabine （GEM） at 30 min standard-dose infusion （30 min-SDI） compared with prolonged low-dose infusion （P-LDI） in patients with advanced non-small-cell lung cancer （NS...To evaluate the efficacy and safety of gemcitabine （GEM） at 30 min standard-dose infusion （30 min-SDI） compared with prolonged low-dose infusion （P-LDI） in patients with advanced non-small-cell lung cancer （NSCLC）. Electronic databases including Pubmed, EMbase, Cochrane Library, CNKI, CBM, and VIP were searched using keywords ＂GEM＂, ＂P-LDI＂, and ＂NSCLC＂. Review Manager 5.3 was used to perform the recta-analysis. Primary endpoints were overall response rate （ORR） and 1-year survival rate （1-year SR）. Secondary endpoints were grade 3/4 hematotoxicity and nausea/vomiting. Six randomized controlled trials （RCTs） with a total of 637 patients were included. The results showed that P-LDI was superior in ORR （OR = 1.50, 95% CI： 1.08-2.10, P = 0.02）, but had an equal 1-year SR （OR = 1.27, 95 % CI： 0.90-1.79, P = 0.18） as compared with 30 min-SDl. For grade 3/4 adverse events, there was no significant difference in anemia （OR = 1.84, 95% CI： 0.61-5.57, P = 0.28） and nausea/vomiting （OR = 1.15, 95% CI： 0.63-2.12, P = 0.64） between the two treatments. However, patients with P-LDI experienced less leukopenia （OR = 0.64, 95% CI： 0.43-0.97, P = 0.04） and thrombocytopenia （OR = 0.37, 95% CI： 0.17-0.80, P = 0.01）. P-LDI was superior in terms of ORR, experienced less grade 3/4 thrombocytopenia and leukopenia compared with 30 min-SDI, and could be a viable treatment option for advanced NSCLC.展开更多
Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental ...Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental reversal of a cell before it reinvents itself, is an important process too. In multicellular organisms, cellular dedifferentiation is the major process underlying totipotency, regeneration and formation of new stem cell lineages. In humans, dedifferentiation is often associated with carcinogenesis. The study of cellular dedifferentiation in animals, particularly early events related to cell fate-switch and determination, is limited by the lack of a suitable,convenient experimental system. The classic example of dedifferentiation is limb and tail regeneration in urodele amphibians, such as salamanders. Recently, several investigators have shown that certain mammalian cell types can be induced to dedifferentiate to progenitor cells when stimulated with the appropriate signals or materials. These discoveries open the possibility that researchers might enhance the endogenous regenerative capacity of mammals by inducing cellular dedifferentiation in vivo.展开更多
文摘Ultrastructural changes in the sieve element and dense cells of nectariferous tissue during the development of floral nectary in Arabidopsis thaliana L. were investigated with transmission electron microscopy. Samples were prepared with high pressure freezing and freeze substitution techniques. The ultrastructure of dense cell was similar to that of sieve element at its early developmental stage. With the concurrent agglutination of chromatin in the nucleus, the abnormal location of organelles and the high density of cytoplasm, the ultrastructural characteristics in die dense cells of the nectariferous tissue and in the sieve element are matched with those of the programmed cell death in animal and plant reported in recent years. The disorganization of nucleus and most organelles in the differentiation of sieve elements and dense cells is closely associated with the transportation and modification of pre-nectar and the transference of nectar. This suggests that the cytological changes in sieve element and nectariferous tissue are closely associated with the nectary functional activities.
基金Supported by the Special Financial Program of Hebei Province,the Fund for Agricultural Science and Technology Innovation Talent Team Construction(2011055001)~~
文摘Coix has a long cultivation history as a minor crop in China, but many problems including unclear origin, chaos of species, loss and inaccurate use of germplasm resources exist in its research and production due to the lack of systematic study. In recent years, the importance of Coix has been realized with the exploration of its effects in treating and preventing cancer. The systematic study of Coix has met a superb development opportunity with the rapid development of biotechnology especially the deep-sequencing technique. Therefore, this paper presented here the current status of origin and evolution, classification, cytology and molecular biology progress of Coix, analyzed the ploidy of Coix and the genetic relationships with Zea, Sorghum and so on from the point of cytology, and then based on the molecular biology, analyzed the important significance of DNA molecular marker, genetic mapping and gene library in the research on identification of genetic relationship between species and genetic breeding, which could provide useful information for further Coix research.
基金supported by Open Fund of Key Laboratory of Bio-Macromolecular Evolution(No.2006B001)Foundation for outstanding academic team of Zoological Biology in Anhui Normal UniversitySpecial Foundation for Provincial Key Laboratories of Biotic Environment and Ecological Safety and Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province
文摘Changes in distribution density,morphology and secretory content of endocrine cells in the gastro-entero-pancreatic system of black-spotted frogs Rana nigromaculata before and after fasting were investigated using immunohistochemistry and antisera to six gut hormones.Six types of endocrine cells were detected in the digestive tract of Rana nigromaculata,including 5-hydroxytryptamine(5-HT),gastrin(GAS),somatostatin(SOM),glucagon(GLU),pancreatic polypeptide(PP)and vasoactive intestinal polypeptide(VIP)cells.After fasting,the density of 5-HT cells in the esophagus,cardia and fundus,GAS cells in the fundus and pylorus,PP cells in the fundus decreased significantly(P<0.01),while SOM cells in the cardia,GLU cells in the rectum increased significantly(P<0.01).The cytoplasmic processes of 5-HT cells became shorter or not detectable.The secretory content of GAS cells reduced in the cardia.The positive immunostaining reaction in the perinuclear region of SOM cells in the cardia,fundus and pylorus became weaker,while the staining intensity in the periphery of these cells became stronger.VIP cells were not detectable in the whole digestive tract after fasting.Five types of endocrine cells were found in the pancreas of Rana nigromaculata,including 5-HT,GAS,SOM,GLU and PP cells.After fasting,the density of 5-HT cells decreased slightly(P>0.05),while SOM,GAS,GLU and PP cells increased significantly(P<0.01).Furthermore,the secretory content of GLU cells increased significantly.Considering their functionalities,our results indicate that the changes of GEP endocrine cells in Rana nigromaculata responded adaptively to starvation-induced stress.
文摘We have examined the myogenic potential of human embryonic stem （hES） cells in a xeno-transplantation animal model. Here we show that precursors differentiated from hES cells can undergo myogenesis in an adult environment and give rise to a range of cell types in the myogenic lineage. This study provides direct evidences that hES cells can regenerate both muscle and satellite cells in vivo and are another promising cell type for treating muscle degenerative disorders in addition to other myogenic cell types.
文摘AIM： To explore the expansion and differentiation of hepatocytoid cell induced from myeloid mesenchymal stem cell （MSC） in vib＇o, in order to find suitable resource of hepatocytes for bioartiflcial liver or liver transplantation. METHODS： The rat myeloid MSC was isolated and divided into three groups which were cultured by Friedensteion method, and then were induced by culture fluid, culture fluid plus cholestatic serum and culture fluid plus hepatocyte growth factor （HGF）, respectively. Hepatocytoid cell as well as expression of CK18 and AFP was observed by immunohistochemistry. RESULTS： After the induction for 21 d, hepatocytoid cell was observed, and its expression of CK18 and AFP was detected by immunohistochemistry in MSC cultured with cholestatic serum. Furthermore, on the 35^th d, albumin mRNA was expressed in the cell, suggesting the inducing effect was similar to that by HGF.CONCLUSION： Rat myeloid MSC can differentiate into hepatocyte lineage under appropriate condition. This method is easy to operate.
文摘Human embryonic stem cells （hESC） not only hold great promise for the treatment of degenerative diseases but also provide a valuable tool for developmental studies. However, the clinical applications of hESC are at present limited by xeno-contamination during the in vitro derivation and propagation of these cells. In this review, we summarize the current methodologies for the derivation and the propagation of hESC in conditions that will eventually enable the generation of clinical-grade cells for future therapeutic applications.
基金Supported by a grant from the National Science Foundation of China (No. 30973496)
文摘Objective: The aim of the study was to explore the protein level of NF-κB change in carcinoma and different grades of tumor cells differentiation tissue in colorectal cancer patients. Methods: This was a comparative study between normal and carcinoma tissues and in different grades of tumor cells differentiation tissue in colorectal cancer patients. Ex-pression of NF-κΒ were assessed by immunohistochemical method using rabbit polyclonal antibodies against human p65 NF-κΒ proteins. Results: There was none or very little expression of NF-κB in non-neoplastic colon epithelial cells, while the expression of it's protein was significantly increased (P < 0.01) in adjacent cancerous cells. Moreover, there was a significant increase in the mean expression of NF-κB-p65 between poorly differentiated malignant epithelial cell and well-differentiated cells (P < 0.05). Conclusion: NF-κB-p65 may play an essential role in colorectal carcinogenesis and may be valuable for diagnosis, evaluating malignancy extent and prognosis.
文摘To evaluate the efficacy and safety of gemcitabine （GEM） at 30 min standard-dose infusion （30 min-SDI） compared with prolonged low-dose infusion （P-LDI） in patients with advanced non-small-cell lung cancer （NSCLC）. Electronic databases including Pubmed, EMbase, Cochrane Library, CNKI, CBM, and VIP were searched using keywords ＂GEM＂, ＂P-LDI＂, and ＂NSCLC＂. Review Manager 5.3 was used to perform the recta-analysis. Primary endpoints were overall response rate （ORR） and 1-year survival rate （1-year SR）. Secondary endpoints were grade 3/4 hematotoxicity and nausea/vomiting. Six randomized controlled trials （RCTs） with a total of 637 patients were included. The results showed that P-LDI was superior in ORR （OR = 1.50, 95% CI： 1.08-2.10, P = 0.02）, but had an equal 1-year SR （OR = 1.27, 95 % CI： 0.90-1.79, P = 0.18） as compared with 30 min-SDl. For grade 3/4 adverse events, there was no significant difference in anemia （OR = 1.84, 95% CI： 0.61-5.57, P = 0.28） and nausea/vomiting （OR = 1.15, 95% CI： 0.63-2.12, P = 0.64） between the two treatments. However, patients with P-LDI experienced less leukopenia （OR = 0.64, 95% CI： 0.43-0.97, P = 0.04） and thrombocytopenia （OR = 0.37, 95% CI： 0.17-0.80, P = 0.01）. P-LDI was superior in terms of ORR, experienced less grade 3/4 thrombocytopenia and leukopenia compared with 30 min-SDI, and could be a viable treatment option for advanced NSCLC.
文摘Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental reversal of a cell before it reinvents itself, is an important process too. In multicellular organisms, cellular dedifferentiation is the major process underlying totipotency, regeneration and formation of new stem cell lineages. In humans, dedifferentiation is often associated with carcinogenesis. The study of cellular dedifferentiation in animals, particularly early events related to cell fate-switch and determination, is limited by the lack of a suitable,convenient experimental system. The classic example of dedifferentiation is limb and tail regeneration in urodele amphibians, such as salamanders. Recently, several investigators have shown that certain mammalian cell types can be induced to dedifferentiate to progenitor cells when stimulated with the appropriate signals or materials. These discoveries open the possibility that researchers might enhance the endogenous regenerative capacity of mammals by inducing cellular dedifferentiation in vivo.
