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1.
Nowadays, infertility is no longer considered as an unsolvable disorder due to progresses in germ cells derived from stem lineage with diverse origins. Technical and ethical challenges push researchers to investigate various tissue sources to approach more efficient gametes. The purpose of the current study is to investigate the efficacy of a combined medium, retinoic acid (RA) together with Bone Morphogenic Protein‐4 (BMP4), on differentiation of Bone Marrow Mesenchymal Stem Cells (BMMSCs) and adipose‐derived mesenchymal stem cells (ADMSCs) into germ cells. Murine MSCs were obtained from both Bone Marrow (BM) and Adipose Tissue (AT) samples and were analyzed for surface markers to get further verification of their nature. BMMSCs and ADMSCs were induced into osteogenic and adipogenic lineage cells respectively, to examine their multipotency. They were finally differentiated into germ cells using media enriched with BMP4 for 4 days followed by addition of RA for 7 days (11 days in total). Analyzing of differentiation potential of BMMSCs‐ and ADMSCs were performed via Immunofluorescence, Flowcytometry and Real time‐PCR techniques for germ cell‐specific markers (Mvh, Dazl, Stra8 and Scp3). Mesenchymal surface markers (CD90 and CD44) were expressed on both BMMSCs and ADMSCs, while endothelial and hematopoietic cell markers (CD31 and CD45) had no expression. Finally, all germ‐specific markers were expressed in both BM and AT. Although germ cells differentiated from ADMSCs showed faster growth and proliferation as well as easy collection, they significantly expressed germ‐specific markers lower than BMMSCs. This suggests stronger differentiation potential of murine BMMSCs than ADMSCs.  相似文献   

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Spermatogenesis is a highly complicated process which initiated by spermatogonial stem cells (SSCs). SSCs are the only cell type that can restore fertility in infertile recipient after SSCs transplantation. SSCs damage during cancer diagnosis and therapy and their depletion may be cause of male infertility in cancer survivors. In this review, used experimental methods regarding SSCs and testis tissue cryopreservation have been reviewed with a special focus on animal models and human which have generated the majority of data about SSCs and the cryopreservation process. Microsc. Res. Tech. 79:122–129, 2016. © 2015 Wiley Periodicals, Inc.  相似文献   

4.
Introduction: Here we co‐cultured hepatic progenitor cells (HPCs) and mesenchymal stem cells (MSCs) to investigate whether the co‐culture environments could increase hepatocytes form. Methods: Three‐dimensional (3D) co‐culture model of HPCs and MSCs was developed and morphological features of cells were continuously observed. Hepatocyte specific markers Pou5f1/Oct4, AFP, CK‐18 and Alb were analyzed to confirm the differentiation of HPCs. The mRNA expression of CK‐18 and Alb was analyzed by RT‐PCR to investigate the influence of co‐culture model to the terminal differentiation process of mature hepatocytes. The functional properties of hepatocyte‐like cells were detected by continuously monitoring the albumin secretion using Gaussia luciferase assays. Scaffolds with HPCs and MSCs were implanted into nude mouse subcutaneously to set up the in vivo co‐culture model. Results: Although two groups formed smooth spheroids and high expressed of CK‐18 and Alb, hybrid spheroids had more regular structures and higher cell density. CK‐18 and Alb mRNA were at a relatively higher expression level in co‐culture system during the whole cultivation time (P < 0.05). Albumin secretion rates in the hybrid spheroids had been consistently higher than that in the mono‐culture spheroids (P < 0.05). In vivo, the hepatocyte‐like cells were consistent with the morphological features of mature hepatocytes and more well‐differentiated hepatocyte‐like cells were observed in the co‐culture group. Conclusions: HPCs and MSCs co‐culture system is an efficient way to form well‐differentiated hepatocyte‐like cells, hence, may be helpful to the cell therapy of hepatic tissues and alleviate the problem of hepatocytes shortage. Microsc. Res. Tech. 78:688–696, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   

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The micro‐X‐ray fluorescence by synchrotron radiation (μ‐XRF) is a method to determine the composition of tissues without destroying the samples. However, this technique has never been used for the analysis of mesenchymal stem cells (MSC). This study compared different protocols for fixing, storing, preserving, and establishing the correct numbers of dental derived MSC submitted to μ‐XRF analysis. Stem cells were obtained from human dental tissue. After cell expansion, and MACS isolation, the samples were fixed and the following quantities of cells 1 × 104 to 1 × 107 were divided in two groups: G1: fixed in 4% paraformaldehyde diluted in phosphate‐buffered saline solution, and G2: fixed in 4% paraformaldehyde diluted in MilliQ water. The G1 cells showed precipitation of chemical components from the solution resulting in the formation of salt crystals while G2 cells were clear and almost transparent in the sample holder. With regards to cells concentration, the best results occurred when four droplets of 1 × 107 cells were analyzed. This work shows that to identify and study the distribution of trace elements in MSC by μ‐XRF, the best protocol is fixation in 4% paraformaldehyde diluted with MilliQ water at 4°C and a concentration of four incremental droplets of 1 × 107 cells. Microsc. Res. Tech. 79:149–154, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

6.
The aim of this study was to analyse the influence of the artificial saliva on a three‐dimensional (3‐D) surface texture of contemporary dental composites. The representatives of four composites types were tested: nanofilled (Filtek Ultimate Body, FUB), nanohybrid (Filtek Z550, FZ550), microfilled (Gradia Direct, GD) and microhybrid (Filtek Z250, FZ250). The specimens were polymerised and polished by the multistep protocol (SuperSnap, Shofu). Their surface was examined, before and after 3 weeks’ exposure to artificial saliva storage. The surface texture was analysed using the atomic force microscope (AFM). The obtained images were processed to calculate the areal autocorrelation function (AACF), anisotropy ratio Str (texture aspect ratio), and structure function (SF). The log–log plots of SF were used to calculate fractal properties, such as fractal dimension D, and pseudo‐topothesy K. The analysis showed changes in surface anisotropy ratio Str values, which became higher, whereas the Sq roughness (root‐mean‐square) reduced after the artificial saliva storage. All the samples exhibited bifractal structure before the saliva treatment, but only half of them remained bifractal afterwards (GD, FZ250), whereas the other half turned into a monofractal (FUB, FZ550). The cube‐count fractal dimension Dcc was found to be material‐ and treatment‐insensitive.  相似文献   

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The present study analyzed the effects of different concentrations of the hexane extract of A. oleraceae (HEAO) (Jambú) on the germ cells of semi‐engorged Rhipicephalus microplus female ticks, through a morpho‐histological study, evaluating the effectiveness of the extract in the genesis of the individuals. To perform this analysis, 100 semi‐engorged females were divided into five groups with 20 individuals each: groups I and II, respectively constituted by distilled water control and 50% ethanol + 1% DMSO, and groups III, IV, and V constituted by treatment with HEAO in the concentrations of 12.5, 25.0 and 50.0 mg/mL, respectively. All the ticks were immersed in the different concentrations of the extract or in distilled water for 5 minutes, dried and conditioned in BOD incubator for 7 days. The individuals of the treatment groups revealed the action of this extract showing alterations in the germ cells of the females from the different groups when compared with those from the groups I and II (control groups). These alterations were mainly related to the size and shape of the oocytes; number of yolk granules; presence, number, size and location of vacuoles in the cytoplasm of all the germ cells; and the presence of nuclear alterations in these cells as well. Thus, it was demonstrated that the concentrations of HEAO affected the germ cells of R. microplus ticks. The effects of the extract are similar to those caused by renowned and efficient chemical products used to control these ticks. Microsc. Res. Tech. 79:744–753, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

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Vitiligo results in an autoimmune disorder destructing skin pigment cells, melanocytes (Mcs). This study aimed to investigate whether Astragaloside IV (AIV) could efficiently induce differentiation of bone marrow mesenchymal stem cells (BMMSCs) into Mcs. BMMSCs were induced and differentiated into Mcs with 0.1, 0.2, and 0.4 mg/L AIV during 150-day. Morphologic changes of differentiated cells were observed. Levels of some melanocytic specific genes (TRP-1, TRP-2, MART-1, Mitf) were measured with quantitative polymerase chain reaction (qPCR) at 90, 120, and 150 days of induction. After 90-day induction, the differentiated cells with 0.4 mg/L AIV demonstrated the typical morphology of Mcs, positive 3,4 dihydroxyphenylalanine staining, and positive staining of TRP-1, TRP-2, MART-1, and Mitf. After 90- and 120- days’ induction with 0.4 mg/L AIV, TRP-1 expression was significantly elevated (p < 0.01), and TRP-2 expression was significantly increased in 0.4 mg/L AIV-treated group compared to negative control (p < 0.01), 0.1 mg/L (p < 0.01), and 0.2 mg/L (p < 0.01) AIV-treated groups. Moreover, MART-1 expression was significantly up-regulated in 0.4 mg/L AIV-treated group compared to negative control, but without difference compared to 0.1 mg/L (p > 0.05) and 0.2 mg/L (p > 0.05) AIV-treated groups. During 90 to 150- day induction, there were no significant differences for Mitf levels between AIV-treated groups and negative control (p > 0.05). In conclusion, 90-day induction with 0.4 mg/L AIV up-regulated TRP-1, TRP-2, and MART-1 expression, indicating that AIV can efficiently induce Mcs differentiation from BMMSCs. These results provide experimental and theoretic evidence for AIV application in clinical vitiligo repigmentation treatment.  相似文献   

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Nowadays, the implementation of sophisticated in situ electron microscopy tests is providing new insights in several areas. In this work, an in situ high‐temperature strain test into a scanning electron microscope was developed. This setup was used to study the grain boundary sliding mechanism and its effect on the ductility dip cracking. This methodology was applied to study the mechanical behaviour of Ni‐base filler metal alloys ERNiCrFe‐7 and ERNiCr‐3, which were evaluated between 700°C and 1000°C. The ductility dip cracking susceptibility (threshold strain; εmin) for both alloys was quantified. The εmin of ERNiCrFe‐7 and ERNiCr‐3 alloys were 7.5% and 16.5%, respectively, confirming a better resistance of ERNiCr‐3 to ductility dip cracking. Furthermore, two separate components of grain boundary sliding, pure sliding (Sp) and deformation sliding (Sd), were identified and quantified. A direct and quantitative link between grain boundary tortuosity, grain boundary sliding and ductility dip cracking resistance has been established for the ERNiCrFe‐7 and ERNiCr‐3 alloys.  相似文献   

10.
We investigated the ultrastructural characteristics of mouse adipose‐derived stem/stromal cells (ASCs) induced towards osteogenic lineage. ASCs were isolated from adipose tissue of FVB‐Cg‐Tg(GFPU)5Nagy/J mice and expanded in monolayer culture. Flow cytometry, histochemical staining, and electron microscopy techniques were used to characterize the ASCs with respect to their ability for osteogenic differentiation capacity. Immunophenotypically, ASCs were characterized by high expression of the CD44 and CD90 markers, while the relative content of cells expressing CD45, CD34 and CD117 markers was <2%. In assays of differentiation, the positive response to osteogenic differentiation factors was observed and characterized by deposition of calcium in the extracellular matrix and alkaline phosphatase production. Electron microscopy analysis revealed that undifferentiated ASCs had a rough endoplasmic reticulum with dilated cisterns and elongated mitochondria. At the end of the osteogenic differentiation, the ASCs transformed from their original fibroblast‐like appearance to having a polygonal osteoblast‐like morphology. Ultrastructurally, these cells were characterized by large euchromatic nucleus and numerous cytoplasm containing elongated mitochondria, a very prominent rough endoplasmic reticulum, Golgi apparatus and intermediate filament bundles. Extracellular matrix vesicles of variable size similar to the calcification nodules were observed among collagen fibrils. Our data provide the ultrastructural basis for further studies on the cellular mechanisms involved in osteogenic differentiation of mouse adipose‐derived stem/stromal cells. Microsc. Res. Tech. 79:557–564, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   

11.
The adsorption and aqueous lubricating behaviour of poly(l ‐lysine)‐graft‐poly(ethylene glycol) (PLL‐g‐PEG) have been investigated for tribopairs involving thermoplastic materials, including polypropylene, polyamide‐6,6 and polyethylene. A major finding is that PLL‐g‐PEG adsorbs onto both hydrophobic, non‐polar surfaces and hydrophilic, polar (negatively charged) surfaces from aqueous solution, and thus plays as a very unique and effective aqueous boundary lubricant additive for the sliding contact of thermoplastics against themselves as well as against many hydrophilic, polar materials, including metals (e.g. stainless steel) or ceramics (e.g. zirconia, ZrO2). Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

12.
Differentiated macrophages have been proven to participate in the development of mesenchymal stem cells in different tissues. However, the regulatory processes remain obscure. Exosomes, which are key secretions of macrophages, have attracted increasing attention. Therefore, macrophage-derived exosomes may modulate the development of Bone marrow mesenchymal stem cells (BMMSCs). Different culture conditions were used to induce M1 polarization in THP1 cells. Subsequently, exosomes derived from unpolarized (M0) and polarized (M1) macrophages were isolated, BMMSCs were cultured with normal complete medium or inductive medium supplemented with M0 or M1 derived exosomes, and the osteogenic capacity of the BMMSCs was measured and analyzed. Finally, molecular mechanism associated with Akt and RUNX2 was investigated. Alizarin red staining and WB experiments showed that M1 macrophages could promote the osteogenic differentiation of BMMSCs better than M0 macrophages. Then, exosomes derived from M0 and M1 macrophages were successfully isolated and analyzed by electron microscopy and WB experiments. We concluded that media containing M1-derived exosomes promoted the osteogenic differentiation of BMMSCs better than media containing M0-derived exosomes. In addition, M1-derived exosomes could activate Akt and increase RUNX2 levels to promote osteogenesis. Our data demonstrated that exosomes derived from M1 macrophages induced osteogenesis by activating Akt and increasing RUNX2 level.  相似文献   

13.
Three alkyloxy‐s‐triazine derivatives were synthesized and their tribological properties as lubricants for steel–steel contact were evaluated using an Optimol SRV tester at 20°C and 100°C. Their thermal stabilities were also investigated by thermogravimetric analysis. The results show that the three alkyloxy‐s‐triazine lubricants have good thermal stability. Moreover, 2,4,6‐tris(1,1,5‐tri‐H‐octafluoropentyloxy)‐1,3,5‐s‐triazine (FPOT) possesses the best anti‐wear property and good load‐carrying capacity both at 20°C and 100°C. At 20°C the anti‐wear effectiveness of 2,4,6‐tris(n‐pentyloxy)‐1,3,5‐s‐triazine (POT) is the worst, while at 100°C that of the 1,1,5‐tri‐H‐octafluoropentyloxy and/or 1,1,7‐tri‐H‐dodecafluoroheptyloxy tri‐substituted s‐triazine mixture (FMOT) is the worst. In addition, the friction‐reducing properties of the two fluoroalkyloxy‐s‐triazines, FPOT and FMOT, are not as good as those of the non‐fluorine‐containing alkyloxy‐s‐triazine POT. Scanning electron spectroscopy with an energy dispersive analyzer of X‐ray and X‐ray photoelectron spectroscopy analyses of the worn surface indicate that during the rubbing process, tribochemical reactions occur between the lubricants and the metal surface to generate a complex boundary lubrication film comprised of FeF2, Fe(OH)2, organofluorine and organonitrogen compounds. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

14.
The objective of this study was to characterize the three‐dimensional (3D) surface micromorphology of the ceramics produced from nanoparticles of alumina and tetragonal zirconia (t‐ZrO2) with addition of Ca+2 for sintering improvement. The 3D surface roughness of samples was studied by atomic force microscopy (AFM), fractal analysis of the 3D AFM‐images, and statistical analysis of surface roughness parameters. Cube counting method, based on the linear interpolation type, applied for AFM data was used for fractal analysis. The morphology of non‐modified ceramic sample was characterized by the rather big (1–2 μm) grains of α‐Al2O3 phase with a habit close to hexagonal drowned in solid solution of t‐ZrO2 with smooth surface. The pattern surfaces of modified composite content a little amount of elongated prismatic grains with composition close to the phase of СаСеAl3О7 as well as hexahedral α‐Al2O3‐grains. Fractal dimension, D, as well as height values distribution have been determined for the surfaces of the samples with and without modifying. It can be concluded that the smoothest surface is of the modified samples with Ca+2 modifier but the most regular one is of the non‐modified samples. A connection was observed between the surface morphology and the physical properties as assessed in previous works. Microsc. Res. Tech. 78:840–846, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   

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An organic compound containing S, N, B, and O was synthesised by reacting 2‐mercaptobenzothiazole and formalin in ethanol solution, the resulting product then being reacted with butanol and boric acid in toluene solution. The tribological performance of the novel compound when added to liquid paraffin was evaluated using a four‐ball tester and a ring‐on‐block machine. The relationship between performance and concentration was analysed, and the results show that the compound possesses good antiwear and load‐carrying abilities. The mechanism of action of the additive was investigated using X‐ray photo‐electron spectroscopy (XPS). Surface analysis indicated the formation of a protective film containing FeSO4, an organo‐sulphur compound, FeS2, borate, and an organonitrogen compound. This protective film formed during sliding processes contributes to the increase in wear resistance.  相似文献   

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Ketogenic diets (KDs) have shown beneficial effects in experimental models of neurodegeneration, designating aged individuals as possible recipients. However, few studies have investigated their consequences on aging brain. Here, late‐adult rats (19 months of age) were fed for 8 weeks with two medium chain triglycerides‐supplemented diets (MCT‐SDs) and the average area (S), numeric density (Nvs), and surface density (Sv) of synapses, as well as the average volume (V), numeric density (Nvm), and volume density (Vv) of synaptic mitochondria were evaluated in granule cell layer of the cerebellar cortex (GCL‐CCx) by computer‐assisted morphometric methods. MCT content was 10 or 20%. About 10%MCT‐SD induced the early appearance of senescent patterns (decreased Nvs and Nvm; increased V), whereas 20%MCT‐SD caused no changes. Recently, we have shown that both MCT‐SDs accelerate aging in the stratum moleculare of CA1 (SM CA1), but are “antiaging” in the outer molecular layer of dentate gyrus (OML DG). Since GCL‐CCx is more vulnerable to age than OML DG but less than SM CA1, present and previous results suggest that the effects of MCT‐SDs in the aging brain critically depend on neuronal vulnerability to age, besides MCT percentage. Microsc. Res. Tech. 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

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Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve‐muscle preparations exposed to Bothrops venoms and their phospholipase A2 toxins (PLA2) can exhibit a neurotoxic pattern as increase in frequency of miniature end‐plate potentials (MEPPs) as well as in amplitude of end‐plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA2 toxins (BthTX‐I and Bbil‐TX) in mouse isolated nerve‐phrenic diaphragm preparations (PND). Under transmission electron microscopy (TEM), PND preparations previously exposed to B. jararacussu and B. bilineatus venoms and BthTX‐I and Bbil‐TX toxins showed hypercontracted and loosed myofilaments; unorganized sarcomeres; clusters of edematous sarcoplasmic reticulum and mitochondria; abnormal chromatin distribution or apoptotic‐like nuclei. The principal affected organelles, mitochondria and sarcoplasmic reticulum, were those related to calcium buffering and, resulting in sarcomeres and myofilaments hypercontraction. Schwann cells were also damaged showing edematous axons and mitochondria as well as myelin sheath alteration. These ultrastructural changes caused by both of Bothrops venoms and toxins indicate that the neuromuscular blockade induced by them in vitro can also be associated with nerve and muscle degeneration.  相似文献   

19.
Colloidal particle size is an important characteristic to consider when choosing a radiopharmaceutical for diagnosis and therapeutic purposes in nuclear medicine. Photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM) were used to determine the particle‐size distribution of 90Y‐ and 99mTc‐labelled antimony trisulfide (Sb2S3) and tin colloids (Sn‐colloid). 90Y‐Sb2S3 and 99mTc‐Sb2S3 were found to have a diameter of 28.92 ± 0.14 and 35.61 ± 0.11 nm, respectively, by PCS. By TEM, 90Y‐Sb2S3 particles were measured to be 14.33 ± 0.09 nm. 90Y‐labelled Sn colloid were found to exist with a dv(max1) of 805 nm and a dv(max2) of 2590 nm, by PCS, whereas 99mTc‐Sn colloid was shown to have more than 80% of radioactive particles of approximately 910 nm by PCS. For 90Y‐labelled Sb2S3 and Sn colloid, a comparison of TEM and PCS indicates that these techniques found significantly different mean diameters. TEM has an excellent resolution necessary for radiocolloid particle‐sizing analysis, and it is a desirable size‐measuring technique because it is more reliable than PCS.  相似文献   

20.
Microtubules are important targets when studying potential anticancer agents since disturbance of these microtubule dynamics results in cell cycle arrest and cell death. 2‐Methoxyestradiol is a naturally occurring metabolite that exerts antiproliferative activity and induces apoptosis. Due to limited biological accessibly and rapid metabolic degradation, several analogs were synthesized. This study investigated the antiproliferative influence of an 2‐methoxyestradiol analog, (8R, 13S, 14S, 17S)‐2‐Ethyl‐13‐methyl‐7, 8, 9, 11, 12,13, 14, 15, 16, 17‐decahydro‐6H‐cyclopenta[a]phenanthrane‐3, 17‐diyl bis(sulfamate) (EMBS) on cell proliferation, morphology and apoptosis induction in a estrogen receptor‐positive breast adenocarcinoma cells line (MCF‐7), estrogen receptor‐negative highly metastatic breast cell line (MDA‐MB‐231) and a non‐tumorigenic breast epithelial cell line (MCF‐12A). Spectrophotometry results indicated that EMBS exerted differential antiproliferative activity in the three cell lines. Cell growth of the breast adenocarcinoma and highly metastatic breast cell line reached a plateau effect at 0.4 μM after 24 h of exposure. Light microscopy and polarization‐optical transmitted light differential interference contrast demonstrated compromised cell density, cells blocked in metaphase and the presence of apoptotic characteristics after EMBS exposure for 24 h in all three cell lines. Transmission electron microscopy and scanning electron microscopy revealed hallmarks of apoptosis namely the presence of apoptotic bodies, shrunken cells and cell debris in EMBS‐exposed cells. This investigation demonstrated that EMBS does exert antimitotic activity and induces apoptosis contributing to elucidating the signal transduction of EMBS in tumorigenic and non‐tumorigenic breast cell lines. Findings warrant in‐depth analysis of specific targets in vitro and subsequent in vivo investigation for anticancer therapy. Microsc. Res. Tech. 77:236–242, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

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