Objective: To observe the oxidative modification of high density lipoprotein (HDL) induced by cultured human arterial smooth muscle cells (SMCs). Methods: HDL cocultured with SMCs at 37℃ in 48 h was subjected, and na...Objective: To observe the oxidative modification of high density lipoprotein (HDL) induced by cultured human arterial smooth muscle cells (SMCs). Methods: HDL cocultured with SMCs at 37℃ in 48 h was subjected, and native HDL (N-HDL) served as control. Oxidative modification of HDL was identified by using agarose gel electrophoresis. Absorbances of conjugated diene (CD) and lipid hydroperoxide (LOOH) were measured with ultraviolet spectrophotometry at 234 and 560 nm respectively, and fluorescence intensity of thiobarbuturic acid reaction substance (TBARS) with fluorescence spectrophotometry at 550 nm emission wavelength with excitation at 515 nm. Results: In comparison with N-HDL, the electrophoretic mobility of SMCs-cocultured HDL was increased, and the contents of CD, LOOH and TBARS HDL were very significantly higher than those of the control HDL (P<0.01). Conclusion: Oxidative modification of HDL can be induced by human arterial SMCs.展开更多
To explore the influence of compound bioelectret material′s dielectric property on the cell growth,several kinds of compound bioelectret materials of collagen/chitosan were developed Their TSDC(thermally stimulated ...To explore the influence of compound bioelectret material′s dielectric property on the cell growth,several kinds of compound bioelectret materials of collagen/chitosan were developed Their TSDC(thermally stimulated depolarization current)spectra were analyzed,and the compound bioelectret collagen/chitosan whose t α and I α were 37℃ and 2×10 -9 A respectively at polarized state was selected The cell culture study showed that the compound bioelectret material could promote normal cell growth when singly negatively polarized,and could inhibit cancer cell growth when singly positively polarized It proves that the rational designation of compound bioelectret has a broad application for clinical medicine展开更多
The aim of this work is to study the effects of the electret property of natural biopolymers (such as collagen) on tissue repair. Type I collagen was prepared from pigskin,and polarized by using the TSDC (thermally st...The aim of this work is to study the effects of the electret property of natural biopolymers (such as collagen) on tissue repair. Type I collagen was prepared from pigskin,and polarized by using the TSDC (thermally stimulated depolarization current) technique. The polarized materials are used for cell culture. and then the cell growth curve is drawn. It was found that the polarized biomaterials accelerated cell differentiation. which indicates that they may be applied in the biomedical field.展开更多
Objective To establish the method of isolation, purification, and identification of human amniotic mesenchymal stem cells (hAMSCs). Methods hAMSCs were isolated from human amniotic membrane by trypsin-collagenase dige...Objective To establish the method of isolation, purification, and identification of human amniotic mesenchymal stem cells (hAMSCs). Methods hAMSCs were isolated from human amniotic membrane by trypsin-collagenase digestion, and cultured in Dulbecco's modified Eagle's medinm/F12 medium supplemented with 10% fetal bovine serum. Phenotypic characteristics of these cells were analyzed by means of immunocytochemistry and flow cytometry. Results The cells successfully isolated from human amniotic membrane expressed representative mesenchymal cell surface markers CD44, CD90, and vimentin, but not CD45. Conclusions This study establishes a potential method for isolation of hAMSCs from human amnion, in vitro culture, and identification. The isolated cells show phenotypic characteristics of mesenchymal stem cells.展开更多
RGD peptides has been used to detect cell surface integrin and direct clinical effective therapeutic drug selection. Herein we report that a quick one step detection of cell surface marker that was realized by a speci...RGD peptides has been used to detect cell surface integrin and direct clinical effective therapeutic drug selection. Herein we report that a quick one step detection of cell surface marker that was realized by a specially designed NiF e-based magnetic biosensing cell chip combined with functionalized magnetic nanoparticles. Magnetic nanoparticles with 20-30 nm in diameter were prepared by coprecipitation and modified with RGD-4C, and the resultant RGD-functionalized magnetic nanoparticles were used for targeting cancer cells cultured on the NiF e-based magnetic biosensing chip and distinguish the amount of cell surface receptor-integrin.Cell lines such as Calu3, Hela, A549, CaF br, HEK293 and HUVEC exhibiting different integrin expression were chosen as test samples. Calu3, Hela, HEK293 and HUVEC cells were successfully identified. This approach has advantages in the qualitative screening test. Compared with traditional method, it is fast, sensitive, low cost,easy-operative, and needs very little human intervention. The novel method has great potential in applications such as fast clinical cell surface marker detection, and diagnosis of early cancer, and can be easily extended to other biomedical applications based on molecular recognition.展开更多
In this study, using Taxus cuspidata as a raw material, we obtained stable high-yielding cell lines by subculturing and quantified paclitaxel content using ultra- sonic extraction combined with TLC-UV spectrophotom- e...In this study, using Taxus cuspidata as a raw material, we obtained stable high-yielding cell lines by subculturing and quantified paclitaxel content using ultra- sonic extraction combined with TLC-UV spectrophotom- etry. In single factor and multiple factors tests to optimize design and study the effects of elicitors, precursors, and metabolic inhibitors on paclitaxel production by Taxus cuspidata cells, paclitaxel production reached 4.32 mg/L when 100 μmol/L methyl jasmonate, 20 mg/L salicylic acid, 400 mg/L phenylalanine and 2 mg/L gibberellin （GA3） were added to the culture medium of suspension cells. When adding metabolic adjustment factors on the 7th day of culture, extra- and intracellular paclitaxel production was the highest at 4.855 mg/L, paclitaxel release rate was 10.48 %, fresh mass and paclitaxel production of cell increased, respectively, by 6.08 and 11.57 %. By controlling the anabolism of paclitaxel, paclitaxel yield was significantly improved.展开更多
Purpose: The use of in vitro cell culture and experimentation is a cornerstone of biomedical research, however, more attention has recently been given to the potential consequences of using such artificial basal media...Purpose: The use of in vitro cell culture and experimentation is a cornerstone of biomedical research, however, more attention has recently been given to the potential consequences of using such artificial basal medias and undefined supplements. As a first step towards better understanding and measuring the impact these systems have on experimental results, we use text mining to capture typical research practices and trends around cell culture.Design/methodology/approach: To measure the scale of in vitro cell culture use, we have analyzed a corpus of 94,695 research articles that appear in biomedical research journals published in ScienceDirect from 2000–2018. Central to our investigation is the observation that studies using cell culture describe conditions using the typical sentence structure of cell line, basal media, and supplemented compounds. Here we tag our corpus with a curated list of basal medias and the Cellosaurus ontology using the Aho-Corasick algorithm. We also processed the corpus with Stanford CoreNLP to find nouns that follow the basal media, in an attempt to identify supplements used. Findings: Interestingly, we find that researchers frequently use DMEM even if a cell line's vendor recommends less concentrated media. We see long-tailed distributions for the usage of media and cell lines, with DMEM and RPMI dominating the media, and HEK293, HEK293 T, and HeLa dominating cell lines used. Research limitations: Our analysis was restricted to documents in ScienceDirect, and our text mining method achieved high recall but low precision and mandated manual inspection of many tokens.Practical implications: Our findings document current cell culture practices in the biomedical research community, which can be used as a resource for future experimental design.Originality/value: No other work has taken a text mining approach to surveying cell culture practices in biomedical research.展开更多
Objective: To investigate in vitro differentiation of oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes in chemical conditional medium. Methods: The mixed glial cells from cerebral cortices of 48-hou...Objective: To investigate in vitro differentiation of oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes in chemical conditional medium. Methods: The mixed glial cells from cerebral cortices of 48-hour-old Sprague-Dawley (SD) rats were cultured in vitro. The OPCs were separated by shaking procedure around 9–10 d in the primary culture. Then the isolated OPCs were further transferred into the chemical conditional medium for cell differentiation. The pattern of OPCs maturation in vitro was continuously observed with contrast phase microscopy and mature oligodendrocytes were further identified by immunocytochemical assays. Results: OPCs grew well when co-cultured with glial cells and distinct cellular stratification formed about 9–10 d in the primary culture, which indicated the appropriate opportunity for the separation of OPCs. Following cultured in the chemical conditional medium, the OPCs progressively differentiated into the mature oligodendrocytes. These mature oligodendrocytes were also immunostained with the oligodendrocyte lineage-specific antibody, Oligo2. Conclusion: The OPCs isolated from the cerebral cortices of neonatal SD rats can progressively differentiate into mature oligodendrocytes in the chemical conditional medium in vitro.展开更多
Objective: To evaluate the osteocompatibility of D, L-polylactic/hydroxyapatite/decalcifying bone matrix (PDLLA/HA/DBM), and compare with PDLLA and DBM. Methods: Human primary osteoblasts isolated from the femoral hea...Objective: To evaluate the osteocompatibility of D, L-polylactic/hydroxyapatite/decalcifying bone matrix (PDLLA/HA/DBM), and compare with PDLLA and DBM. Methods: Human primary osteoblasts isolated from the femoral head of patients were inoculated onto PDLLA/HA/DBM, PLA and DBM respectively. The proliferation rate and collagen Ⅰ expression were detected. The interface between biomaterial and osteoblasts was investigated with phase contrast microscopy and electron scanning microscopy. Results: Best proliferation rate was observed with the PDLLA/HA/DBM and followed by DBM and PLA, suggesting that PDLLA/HA/DBM satisfying most requirements for the cultivation of human osteoblasts. Scanning electron microscopy showed the morphology of osteoblasts was correlated with the proliferation data. The cells, well spread and flattened, were attached closely on the surface of biomaterial with an arched structure and had normal morphology. The extracellular collagenous matrixs covered the surface of biomaterial and packed the granules of biomaterial. Conclusion: PDLLA/HA/DBM can form osteointerface early and have a good biocompability.展开更多
The purpose of this study was to explore the change of telomerase in passage from human endometrial stromal stem cells isolated from human endometrium.Telomerase activity of cultured endometrial stromal cells was asse...The purpose of this study was to explore the change of telomerase in passage from human endometrial stromal stem cells isolated from human endometrium.Telomerase activity of cultured endometrial stromal cells was assessed at mRNA and protein levels using RT-PCR and immunohistochemistry technique.Telomerase mRNA and protein levels were higher at early passages,and then had a gradually decreased trend of immunoreactive intensity and gradually weakened positive cells with progressive passage in endometrial stromal stem cells.These results suggest that telomerase is contributed to the insenecence of endometrial stem cell.展开更多
Objective: To observe the ordered growth behavior of human urinary bladder cancer cell line (BIU) under culture in vitro. Methods: The suspension of BIU cells was spread locally in a culture container. When the cells ...Objective: To observe the ordered growth behavior of human urinary bladder cancer cell line (BIU) under culture in vitro. Methods: The suspension of BIU cells was spread locally in a culture container. When the cells grew a-long the wall to form a cellular colony, macroscopic and microscopic observations complemented with measurements of the parameters including expanding diameter, expanding rate, cell shape. average cell density, average cell size. dehydrogenase activity and sensitivity to pH were conducted dynamically. Results: During cell culture, obvious laminar characteristics appeared in localized growing BIU cell colonies and there was difference between the cells of different zones in shape, size, density, dehydrogenase activity and sensitivity to pH. Conclusion: Space closing and bio-dissipation result in self-organization of BIU cells with ordered growth behavior. The present experiment offers a simple, controllable model for the study of wavy growth of human cells.展开更多
喉癌是上呼吸道常见的恶性肿瘤,严重影响着人类的健康。研究表明热休克蛋白70(heat shock protein 70,HSP70)在正常组织中多不表达,但在包括头颈鳞状细胞癌在内的多种肿瘤组织却有异常表达。肿瘤细胞中高表达的HSP70,对细胞的增殖、侵...喉癌是上呼吸道常见的恶性肿瘤,严重影响着人类的健康。研究表明热休克蛋白70(heat shock protein 70,HSP70)在正常组织中多不表达,但在包括头颈鳞状细胞癌在内的多种肿瘤组织却有异常表达。肿瘤细胞中高表达的HSP70,对细胞的增殖、侵袭及转移、机体对肿瘤治疗耐受性的发生及肿瘤预后等方面均有很重要的作用[1]。RNA干扰(RNA interference,RNAi)技术是近年来发展起来的一项新的基因技术。展开更多
Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer,...Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. However, these plants are all near-extinction species due to over-collection and their own biological characteristics. The chemical synthesis of podophyllotoxin is so complicated that its price is unbelievably high. This paper discusses the current status of the biosynthetic pathway of podophyllotoxin and that of the podophyllotoxin production using several biotechnological approaches such as plant organ cultures, plant cell cultures with both flasks and bioreactors, hairy root cultures, bioconversions and metabolic regulations.展开更多
This study investigates the influence of two types of target,skin tissue and cell culture medium,with different permittivities on a k Hz helium atmospheric pressure plasma jet(APPJ)during its application for wound hea...This study investigates the influence of two types of target,skin tissue and cell culture medium,with different permittivities on a k Hz helium atmospheric pressure plasma jet(APPJ)during its application for wound healing.The basic optical-electrical characteristics,the initiation and propagation and the emission spectra of the He APPJ under different working conditions are explored.The experimental results show that,compared with a jet freely expanding in air,the diameter and intensity of the plasma plume outside the nozzle increase when it interacts with the pigskin and cell culture medium targets,and the mean velocity of the plasma bullet from the tube nozzle to a distance of 15 mm is also significantly increased.There are also multiple increases in the relative intensity of OH(A^(2)Σ→X^(2)Π)and O(3p^(5)S-3s^(5)S)at a position 15 mm away from nozzle when the He APPJ interacts with cell culture medium compared with the air and pigskin targets.Taking the surface charging of the low permittivity material capacitance and the strengthened electric field intensity into account,they make the various characteristics of He APPJ interacting with two different targets together.展开更多
Objective: To isolate neural progenitors from midbrain of new born rats. Methods: Cell groups with cloning capability were obtained from midbrain of new-born rats by using serum-free and floating cell culture. Immunoc...Objective: To isolate neural progenitors from midbrain of new born rats. Methods: Cell groups with cloning capability were obtained from midbrain of new-born rats by using serum-free and floating cell culture. Immunocytochemistry was applied to detect antigens such as BrdU, Nestin and specific markers for mature neural cells. Results: Cell groups isolated from midbrain propagated in succession and shaped 'neuro-spheres'. Nestin antigen was expressed in the course of proliferation. After differentiation, epitopes of neuron , astrocyte and oligodendrocyte were all found in the neural progenitors-derived cells, the most majority were astrocyte-epitoped cells. Conclusion: Cell groups expressing Nestin isolated from midbrain of new-born rats have properties of propagating, multi-potency differentiating and self-renewal. It is demonstrated that the cell groups are stem-like neural progenitors in the central nervous system, which are qualified for cell therapy of diseases in central nervous system.展开更多
文摘Objective: To observe the oxidative modification of high density lipoprotein (HDL) induced by cultured human arterial smooth muscle cells (SMCs). Methods: HDL cocultured with SMCs at 37℃ in 48 h was subjected, and native HDL (N-HDL) served as control. Oxidative modification of HDL was identified by using agarose gel electrophoresis. Absorbances of conjugated diene (CD) and lipid hydroperoxide (LOOH) were measured with ultraviolet spectrophotometry at 234 and 560 nm respectively, and fluorescence intensity of thiobarbuturic acid reaction substance (TBARS) with fluorescence spectrophotometry at 550 nm emission wavelength with excitation at 515 nm. Results: In comparison with N-HDL, the electrophoretic mobility of SMCs-cocultured HDL was increased, and the contents of CD, LOOH and TBARS HDL were very significantly higher than those of the control HDL (P<0.01). Conclusion: Oxidative modification of HDL can be induced by human arterial SMCs.
文摘To explore the influence of compound bioelectret material′s dielectric property on the cell growth,several kinds of compound bioelectret materials of collagen/chitosan were developed Their TSDC(thermally stimulated depolarization current)spectra were analyzed,and the compound bioelectret collagen/chitosan whose t α and I α were 37℃ and 2×10 -9 A respectively at polarized state was selected The cell culture study showed that the compound bioelectret material could promote normal cell growth when singly negatively polarized,and could inhibit cancer cell growth when singly positively polarized It proves that the rational designation of compound bioelectret has a broad application for clinical medicine
文摘The aim of this work is to study the effects of the electret property of natural biopolymers (such as collagen) on tissue repair. Type I collagen was prepared from pigskin,and polarized by using the TSDC (thermally stimulated depolarization current) technique. The polarized materials are used for cell culture. and then the cell growth curve is drawn. It was found that the polarized biomaterials accelerated cell differentiation. which indicates that they may be applied in the biomedical field.
基金Supported by Science and Technology Program of Shenyang (2009-090063, 2011-F10-222-4-00)
文摘Objective To establish the method of isolation, purification, and identification of human amniotic mesenchymal stem cells (hAMSCs). Methods hAMSCs were isolated from human amniotic membrane by trypsin-collagenase digestion, and cultured in Dulbecco's modified Eagle's medinm/F12 medium supplemented with 10% fetal bovine serum. Phenotypic characteristics of these cells were analyzed by means of immunocytochemistry and flow cytometry. Results The cells successfully isolated from human amniotic membrane expressed representative mesenchymal cell surface markers CD44, CD90, and vimentin, but not CD45. Conclusions This study establishes a potential method for isolation of hAMSCs from human amnion, in vitro culture, and identification. The isolated cells show phenotypic characteristics of mesenchymal stem cells.
基金supported by National Key Basic Research Program (973 Project) (No. 2010CB933901 and 2011CB933100)National 863 Hi-tech Project of China (No. 2012AA022703), National Natural Scientific Fund (No. 81225010, 81101169 and 31100717)Shanghai Nano project (13NM1401500), Specialized Research Fund for the Doctoral Program of Higher Education (No. 20110073120072)
文摘RGD peptides has been used to detect cell surface integrin and direct clinical effective therapeutic drug selection. Herein we report that a quick one step detection of cell surface marker that was realized by a specially designed NiF e-based magnetic biosensing cell chip combined with functionalized magnetic nanoparticles. Magnetic nanoparticles with 20-30 nm in diameter were prepared by coprecipitation and modified with RGD-4C, and the resultant RGD-functionalized magnetic nanoparticles were used for targeting cancer cells cultured on the NiF e-based magnetic biosensing chip and distinguish the amount of cell surface receptor-integrin.Cell lines such as Calu3, Hela, A549, CaF br, HEK293 and HUVEC exhibiting different integrin expression were chosen as test samples. Calu3, Hela, HEK293 and HUVEC cells were successfully identified. This approach has advantages in the qualitative screening test. Compared with traditional method, it is fast, sensitive, low cost,easy-operative, and needs very little human intervention. The novel method has great potential in applications such as fast clinical cell surface marker detection, and diagnosis of early cancer, and can be easily extended to other biomedical applications based on molecular recognition.
基金supported by development plan project during ‘‘the 12th Five Year Plan’’ Nation Science and Technology in rural area(No.2012AA10A506-04 and No.2013AA103005-04)Changchun City science and technology development program(No.2014174)Changchun City science and technology support program(No.2014NK002)
文摘In this study, using Taxus cuspidata as a raw material, we obtained stable high-yielding cell lines by subculturing and quantified paclitaxel content using ultra- sonic extraction combined with TLC-UV spectrophotom- etry. In single factor and multiple factors tests to optimize design and study the effects of elicitors, precursors, and metabolic inhibitors on paclitaxel production by Taxus cuspidata cells, paclitaxel production reached 4.32 mg/L when 100 μmol/L methyl jasmonate, 20 mg/L salicylic acid, 400 mg/L phenylalanine and 2 mg/L gibberellin （GA3） were added to the culture medium of suspension cells. When adding metabolic adjustment factors on the 7th day of culture, extra- and intracellular paclitaxel production was the highest at 4.855 mg/L, paclitaxel release rate was 10.48 %, fresh mass and paclitaxel production of cell increased, respectively, by 6.08 and 11.57 %. By controlling the anabolism of paclitaxel, paclitaxel yield was significantly improved.
文摘Purpose: The use of in vitro cell culture and experimentation is a cornerstone of biomedical research, however, more attention has recently been given to the potential consequences of using such artificial basal medias and undefined supplements. As a first step towards better understanding and measuring the impact these systems have on experimental results, we use text mining to capture typical research practices and trends around cell culture.Design/methodology/approach: To measure the scale of in vitro cell culture use, we have analyzed a corpus of 94,695 research articles that appear in biomedical research journals published in ScienceDirect from 2000–2018. Central to our investigation is the observation that studies using cell culture describe conditions using the typical sentence structure of cell line, basal media, and supplemented compounds. Here we tag our corpus with a curated list of basal medias and the Cellosaurus ontology using the Aho-Corasick algorithm. We also processed the corpus with Stanford CoreNLP to find nouns that follow the basal media, in an attempt to identify supplements used. Findings: Interestingly, we find that researchers frequently use DMEM even if a cell line's vendor recommends less concentrated media. We see long-tailed distributions for the usage of media and cell lines, with DMEM and RPMI dominating the media, and HEK293, HEK293 T, and HeLa dominating cell lines used. Research limitations: Our analysis was restricted to documents in ScienceDirect, and our text mining method achieved high recall but low precision and mandated manual inspection of many tokens.Practical implications: Our findings document current cell culture practices in the biomedical research community, which can be used as a resource for future experimental design.Originality/value: No other work has taken a text mining approach to surveying cell culture practices in biomedical research.
文摘Objective: To investigate in vitro differentiation of oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes in chemical conditional medium. Methods: The mixed glial cells from cerebral cortices of 48-hour-old Sprague-Dawley (SD) rats were cultured in vitro. The OPCs were separated by shaking procedure around 9–10 d in the primary culture. Then the isolated OPCs were further transferred into the chemical conditional medium for cell differentiation. The pattern of OPCs maturation in vitro was continuously observed with contrast phase microscopy and mature oligodendrocytes were further identified by immunocytochemical assays. Results: OPCs grew well when co-cultured with glial cells and distinct cellular stratification formed about 9–10 d in the primary culture, which indicated the appropriate opportunity for the separation of OPCs. Following cultured in the chemical conditional medium, the OPCs progressively differentiated into the mature oligodendrocytes. These mature oligodendrocytes were also immunostained with the oligodendrocyte lineage-specific antibody, Oligo2. Conclusion: The OPCs isolated from the cerebral cortices of neonatal SD rats can progressively differentiate into mature oligodendrocytes in the chemical conditional medium in vitro.
文摘Objective: To evaluate the osteocompatibility of D, L-polylactic/hydroxyapatite/decalcifying bone matrix (PDLLA/HA/DBM), and compare with PDLLA and DBM. Methods: Human primary osteoblasts isolated from the femoral head of patients were inoculated onto PDLLA/HA/DBM, PLA and DBM respectively. The proliferation rate and collagen Ⅰ expression were detected. The interface between biomaterial and osteoblasts was investigated with phase contrast microscopy and electron scanning microscopy. Results: Best proliferation rate was observed with the PDLLA/HA/DBM and followed by DBM and PLA, suggesting that PDLLA/HA/DBM satisfying most requirements for the cultivation of human osteoblasts. Scanning electron microscopy showed the morphology of osteoblasts was correlated with the proliferation data. The cells, well spread and flattened, were attached closely on the surface of biomaterial with an arched structure and had normal morphology. The extracellular collagenous matrixs covered the surface of biomaterial and packed the granules of biomaterial. Conclusion: PDLLA/HA/DBM can form osteointerface early and have a good biocompability.
基金Supported by the National Natural Science Foundation of China(30801238)
文摘The purpose of this study was to explore the change of telomerase in passage from human endometrial stromal stem cells isolated from human endometrium.Telomerase activity of cultured endometrial stromal cells was assessed at mRNA and protein levels using RT-PCR and immunohistochemistry technique.Telomerase mRNA and protein levels were higher at early passages,and then had a gradually decreased trend of immunoreactive intensity and gradually weakened positive cells with progressive passage in endometrial stromal stem cells.These results suggest that telomerase is contributed to the insenecence of endometrial stem cell.
文摘Objective: To observe the ordered growth behavior of human urinary bladder cancer cell line (BIU) under culture in vitro. Methods: The suspension of BIU cells was spread locally in a culture container. When the cells grew a-long the wall to form a cellular colony, macroscopic and microscopic observations complemented with measurements of the parameters including expanding diameter, expanding rate, cell shape. average cell density, average cell size. dehydrogenase activity and sensitivity to pH were conducted dynamically. Results: During cell culture, obvious laminar characteristics appeared in localized growing BIU cell colonies and there was difference between the cells of different zones in shape, size, density, dehydrogenase activity and sensitivity to pH. Conclusion: Space closing and bio-dissipation result in self-organization of BIU cells with ordered growth behavior. The present experiment offers a simple, controllable model for the study of wavy growth of human cells.
文摘喉癌是上呼吸道常见的恶性肿瘤,严重影响着人类的健康。研究表明热休克蛋白70(heat shock protein 70,HSP70)在正常组织中多不表达,但在包括头颈鳞状细胞癌在内的多种肿瘤组织却有异常表达。肿瘤细胞中高表达的HSP70,对细胞的增殖、侵袭及转移、机体对肿瘤治疗耐受性的发生及肿瘤预后等方面均有很重要的作用[1]。RNA干扰(RNA interference,RNAi)技术是近年来发展起来的一项新的基因技术。
基金Supported by the Natural Science Foundation of Tibet (Grant No. 2002-66)
文摘Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. However, these plants are all near-extinction species due to over-collection and their own biological characteristics. The chemical synthesis of podophyllotoxin is so complicated that its price is unbelievably high. This paper discusses the current status of the biosynthetic pathway of podophyllotoxin and that of the podophyllotoxin production using several biotechnological approaches such as plant organ cultures, plant cell cultures with both flasks and bioreactors, hairy root cultures, bioconversions and metabolic regulations.
基金supported in part by the Scientific Innovation Practice Project of Postgraduates of Chang’an University(No.300103714007)the Fundamental Research Funds for the Central Universities(No.300102329301)National Natural Science Foundation of China(No.51677146)。
文摘This study investigates the influence of two types of target,skin tissue and cell culture medium,with different permittivities on a k Hz helium atmospheric pressure plasma jet(APPJ)during its application for wound healing.The basic optical-electrical characteristics,the initiation and propagation and the emission spectra of the He APPJ under different working conditions are explored.The experimental results show that,compared with a jet freely expanding in air,the diameter and intensity of the plasma plume outside the nozzle increase when it interacts with the pigskin and cell culture medium targets,and the mean velocity of the plasma bullet from the tube nozzle to a distance of 15 mm is also significantly increased.There are also multiple increases in the relative intensity of OH(A^(2)Σ→X^(2)Π)and O(3p^(5)S-3s^(5)S)at a position 15 mm away from nozzle when the He APPJ interacts with cell culture medium compared with the air and pigskin targets.Taking the surface charging of the low permittivity material capacitance and the strengthened electric field intensity into account,they make the various characteristics of He APPJ interacting with two different targets together.
基金National Natural Science Foundation of China (No. 30170469)
文摘Objective: To isolate neural progenitors from midbrain of new born rats. Methods: Cell groups with cloning capability were obtained from midbrain of new-born rats by using serum-free and floating cell culture. Immunocytochemistry was applied to detect antigens such as BrdU, Nestin and specific markers for mature neural cells. Results: Cell groups isolated from midbrain propagated in succession and shaped 'neuro-spheres'. Nestin antigen was expressed in the course of proliferation. After differentiation, epitopes of neuron , astrocyte and oligodendrocyte were all found in the neural progenitors-derived cells, the most majority were astrocyte-epitoped cells. Conclusion: Cell groups expressing Nestin isolated from midbrain of new-born rats have properties of propagating, multi-potency differentiating and self-renewal. It is demonstrated that the cell groups are stem-like neural progenitors in the central nervous system, which are qualified for cell therapy of diseases in central nervous system.
