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ultrastructure

ultrastructure的相关文献在1989年到2022年内共计58篇,主要集中在肿瘤学、内科学、植物学 等领域,其中期刊论文58篇、相关期刊34种,包括上海大学学报(英文版)、外科研究与新技术、中国草食动物科学等; ultrastructure的相关文献由219位作者贡献,包括ADELINA FERREIRA、AMOURA M.ABOU-EL-NAGA、Abdessamad Boukari等。

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总计:58篇

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ultrastructure

-研究学者

  • ADELINA FERREIRA
  • AMOURA M.ABOU-EL-NAGA
  • Abdessamad Boukari
  • Alexander N Orekhov
  • Alexis Béakou
  • Ali Ahmed
  • Allu Prasada Rao
  • Ana C. Rodrigues
  • Ana L. Scopel
  • Anatoly Ivanov
  • 期刊论文

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    • Hiroki Bochimoto; Yo Ishihara; Nur Khatijah Mohd Zin; Hiroyoshi Iwata; Daisuke Kondoh; Hiromichi Obara; Naoto Matsuno
    • 摘要: BACKGROUND The machine perfusion(MP)preservation including hypothermic MP(HMP)and midthermic MP(MMP)has been considered as a promising strategy to preserve the functions of liver donated after cardiac death.The importance of understanding liver sinusoidal endothelial cells(LSEC)damage in regulating liver injury during MP has been emphasized.However,the ultrastructural changes in the LSEC and sinusoids around them after MP are unclear.AIM To investigate the ultrastructural changes in the LSEC and sinusoids around them after MP.METHODS Porcine liver grafts undergo a warm ischemia time of 60 minutes perfused for 4 h with modified University of Wisconsin gluconate solution.Group A grafts were preserved with HMP at 8°C constantly for 4 h.Group B grafts were preserved with a rewarming solution at 22°C by MMP for 4 h.Then the ultrastructural changes in the LSEC and sinusoids in Group A and B were comparatively analyzed by using osmium-maceration scanning electron microscopy with complementary transmission electron microscopy methods.RESULTS An analysis of the LSEC after warm ischemia revealed that mitochondria with condensed-shaped cristae,abnormal vesicles,reduction of ribosomes and the endoplasmic reticulum(ER)surround the mitochondria appeared.The MP subsequent after warm ischemia alleviate the abnormal vesicles and reduction of ribosomes in LSEC,which indicated the reduction of the ER damage.However,MMP could restore the tubular mitochondrial cristae,while after HMP the condensed and narrow mitochondrial cristae remained.In addition,the volume of the sinusoidal space in the liver grafts after MMP were restored,which indicated a lower risk of pressure injury than HMP.CONCLUSION MMP alleviates the ER damage of LSEC by warm ischemia,additionally restore the metabolism of LSEC via the normalization of mitochondria and prevent the share stress damage of liver grafts.
    • AMOURA M.ABOU-EL-NAGA; SHAKER A.MOUSA; FAYEZ ALTHOBAITI; EMAN FAYAD; ENGY S.FAHIM
    • 摘要: Testicular damage is one of the most hazardous effects as it’s associated with azoospermia.Busulfan(Bu)is a highly toxic chemotherapeutic drug that affects testis.Thirty male Swiss albino mice divided into six groups of 5 animals each.Control(oral 0.9%saline daily for 75 days);Mel(20 mg/kg/day orally for 30 days);ZnO NPs(5 mg/kg/day i.p.for 30 days);BU(single i.p.injection of 40 mg/kg and then left for 45 days);BU+Mel(single 40 mg/kg dose of BU and left for 45 days followed by 20 mg/kg/day Mel for 30 days);BU+ZnO NPs(single dose of 40 mg/kg of BU and left for 45 days,then 5 mg/kg/day ZnO NPs for 30 days).Preparation and Characterization of ZnO NPs.Specimens from testis prepared for ultrastructural investigations using TEM after Masson’s trichrome and toluidine blue staining.BU induced histological and ultrastructural damage of the testis.Moreover,the present results could be concluded that Mel or ZnO NPs can protect the testicular tissue against ultrastructural alterations induced by BU by its antioxidant and anti-apoptotic effects.
    • LIN Chenwen; GAO Xinming; NI Jie; ZHANG Shengshuo; LIU Cheng; LUO Shengyu; DU Chen; ZHENG Xuebin; HOU Congcong; TANG Daojun; ZHANG Chundan; ZHU Junquan
    • 摘要: Mitochondria are important for animals’fertility,and their morphologies and functions during spermatogenesis are un-der investigation.However,the molecular mechanism that regulates the mitochondrial dynamic during spermatogenesis is still un-known.In this study,the cytological features of spermatogenesis were investigated in Larimichthys crocea.In addition,the structure and function of prohibitin(PHB),which is associated with mitochondrial structure and dynamic,was also investigated.The full-length cDNA and protein(Lc-PHB)from the L.crocea phb gene(Lc-phb)contained 1625 base pairs and 271 amino acids,respec-tively.Lc-PHB had a conserved primary structure that resulted in a transmembrane,SPFH(the analogous region of proteins stomat-ins,prohibitins,flotillins and HflK/C),and coiled-coil domains.It was detected at high levels in the muscle,liver,and heart,and at intermediate levels in the testis,gill,and brain.Lc-phb mRNA expression was detected in spermatogenic cells by fluorescence in situ hybridization.An immunofluorescence assay revealed that PHB protein was localized in the mitochondria during spermatogenesis.Specifically,PHB expression was detected in the perinuclear cytoplasm of spermatogonia,spermatocytes,and spermatids in the early developmental stage,and mainly localized on one side of the nuclei in the cytoplasm of spermatids in a middle developmental stage,and finally on the sperm midpiece.Western blotting showed that PHB was located in the extracted mitochondria protein fraction but not in the cytoplasm protein fraction of testes.Conclusively,these results indicated that PHB was expressed in the mitochondria dur-ing spermatogenesis.In addition,the study explained the mitochondrial dynamic during fish spermatogenesis and proposed a possi-ble relationship among PHB,spermatogenesis,and male fertility.
    • LORENZO ALIBARDI; BERND NOECKER
    • 摘要: The differentiation of cells composing mature human hairs produces layers with different corneous characteristics that would tend to flake away one from another,as in the corneous layer of the epidermis,without anchoring junctions.It is likely that cell junctions established in the forming cells of the hair bulb are not completely degraded like in the corneous layer of the epidermis but instead remain in the hair shaft to bind mature cuticle,cortex,and medulla cells into a compact hair shaft.During cell differentiation in hairs,cell junctions seem to disappear,and little is known about the fate of junctional proteins present in the mature human hair shaft.The present ultrastructural immunogold study has detected some marker proteins of adhesion junction(cadherin and beta-catenin)and tight junctions(occludin and cingulin)that are still present in cornified hairs where numerous isopeptide bonds are detected,especially in the medulla.This qualitative ultrastructural study indicates that aside from the cell membrane complex,a long corneo-desmosome bonding cortex and cuticle cells,also sparse adherens and tight junction remnants are present.It is suggested that the cornification of these junctions with the incorporation of their proteins within the mature corneous material of the hair shaft likely contributes to maintaining the integrity of the mature hair.This information will also allow us to evaluate the effects of different chemical components present in hair formulations and stains on these junctional proteins and the consequent integrity of the hair shaft.
    • Maria Eduarda de Farias Albuquerque Gaspar de Oliveira; Christina Alves Peixoto; Rosa Valéria da Silva Amorim
    • 摘要: The continuous search for an antimicrobial agent led to the identification of potential antimicrobial biomaterials based on polymers naturals, such as chitosan (CS). However, the mechanism of action of antibacterial activity of CS for gram-positive and gram-negative bacteria was not completely elucidated. The aim of this work is to report the antibacterial activity of CS through ultrastructural analyses of the clinical isolates Staphylococcus aureus and Escherichia coli by Transmission Electron Microscopy. The CS has a bactericidal action against S. aureus and E. coli which alters its cellular ultrastructure, such as with collapsed cell walls, condensed chromatin and the increase of intracellulares structures like vacuoles and cell debris. In this way, the CS represents a potential model for the future design of antibacterial in order to control bacterial resistance of patients in hospital settings.
    • Héctor J. Finol; Héctor Luis Osorio-Vega; Radharani Dorta-Ledezma; Antonio Roschman-González; Blanca Muller; Israel Montes de Oca
    • 摘要: Muscle biopsies from two female patients with systemic sclerosis (SS) and an inflammatory myopathy were studied ultrastructurally in relation to the possible presence of apoptosis in skeletal muscle fibers. Undergoing apoptosis showed characteristic morphological features of this process, including chromatin aggregation as well as nuclear and sarcoplasmic partition into membrane bound-vacuoles (apoptotic bodies) which contained autophagosomes, mitochondria, isolated myofilaments and nuclear material. Vacuoles exhibited different diameters and were covered by single membranes, appearing beneath basement membrane. Apoptosis occurred in some fiber segments as in necrosis or included whole atrophied fibers. These results indicate that apoptosis coexists with necrosis in the inflammatory myopathy of SS.
    • Sahar Youssef
    • 摘要: Orlistat is a safe and effective drug to treat obesity by acting as a pancreatic and gastric lipase inhibitor, resulting in reduction in fat absorption. There is also concern that it may be linked with an increased threat of serious hepatic incidents. The present work was carried out to study the effect of orlistat on the histological, immunohistochemical and electron microscopic structure of the liver in the adult male albino rats and the possible protective role of β-carotene administration. Forty adult albino rats were subjected to experiment for two weeks as follows: group 1 (control), group II, each animal received 0.52 mg/kg bw/day β-Carotene, group III, each animal received orlistat 32 mg/kg/day, and group IV received β-Carotene, 1hour before the administration of orlistat at same dose of group II & III. The liver from each animal was dissected out and processed for histological, (light and electron microscopic study). The result of Hep-Par1 for immunohistochemistry was statistically analyzed. The results showed that orlistat treated group displayed variable disturbance of liver architecture, from dilatation, congested central and portal veins, branching of bile ductules, mononuclear cellular infiltration, areas of hemorrhages, cytoplasmic vacuolation and pyknotic nuclei. The most obvious changes were that degenerative changes in hepatocytes led to depletion of glycogen content of hepatocytes. Hep Par-1 revealed a wide area of negative immune expression around the central vein and in some hepatocytes. Other hepatocytes expressed weak reaction. Ultrastructure examination displayed hepatocytes with swollen mitochondria and others with an electron-dense matrix. The combined treatment of β-Carotene and orlistat led to a marked improvement in most of the previously mentioned changes. It was concluded that orlistat-induced hepatic toxicity. Thus, clinicians should cautiously monitor their patients for signs of hepatic dysfunction. Using an antioxidant such as β-Carotene decreased the toxicity of orlistat.
    • Richard Ntenga; Etienne Mfoumou; Alexis Béakou; Martin Tango; Jordan Kamga; Ali Ahmed
    • 摘要: The ultrastructure and physicochemical and thermal properties of Palm Kernel Shells (PKS) in comparison with Coconut Kernel Shells (CKS) were investigated herein. Powder samples were prepared and characterized using Surface Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Chemical and elemental constituents, as well as thermal performance were assessed by Van Soest Method, TEM/EDXA and SEM/EDS techniques. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were also performed for thermal characterization. SEM/EDS and TEM/EDXA revealed that most of the PKS and CKS materials are composed of particles with irregular morphology;these are mainly amorphous phases of carbon/oxygen with small amounts of K, Ca and Mg. The DSC data permitted to derive the materials’ thermal transition phases and the relevant characteristic temperatures and physical properties. Thermal Transition phases of PKS observed herein are consistent with the chemical composition obtained and are similar to those of CKS. Nonetheless, TGA/DTG showed that the combustion characteristics of PKS are higher than those of CKS. Taken together, our results reveal that PKS have nanopores and can be efficiently used for 3D printing and membrane filtration applications. Moreover, the chemical constituents found in PKS samples are in agreement with those reported in the literature for material structural applications and thus, present potential use of PKS in these applications.
    • 摘要: 牛瑞燕:副教授,博士研究方向:环境兽医学近年来发表的代表性作品论文1.Effects of fluoride on microtubule ultrastructure and expression of Tubα1a and Tubβ2a in mouse hippocampus.Chemosphere 2015;139:422-427,(第一作者,SCI收录)2.Changes in Liver antioxidant status of offspring mice induced by maternal fluoride exposure during gestation and lactation.Biol Trace Elem Res 2016;172(1):172-178.
    • Betzaida Jiménez-Francisco; Carlos Trejo; Hilda Araceli Zavaleta-Mancera; Blanca Moreno-Gómez; Edmundo García-Moya; Florentino Víctor Conde-Martínez; Gerardo Armando Aguado-Santacruz
    • 摘要: In this work, we present an ultrastructural and physiological description of a novel chlorophyll-deficient, yellow cell line of the grass Bouteloua gracilis that develops etioplast-like plastids in presence of light (YELP). These mutant cells were compared to the parental, wild-type, highly chlorophyllous cells from which they were isolated. Growth analysis, based on fresh and dry weights, indicated that YELP accumulates biomass at a slower rate than the parental, green cells. Besides, YELP developed very low levels of photosynthetic pigments, reaching only 9.3% and 38.4% of chlorophyll a and chlorophyll b, respectively, developed by the wild-type cells. Likewise, the accessory pigments, carotenes and xanthophylls, were only synthesized at 8.0% and 5.4%, respectively, of the levels reached by the green cells. Electron microscopy revealed remarkable differences in plastid ultrastructure between the wild-type and mutant cells. Plastids of YELP were heterogeneous and smaller than those found in wild-type cells. YELP plastids were abnormal with poorly developed membrane systems that prevented the accumulation of chlorophyll and accessory pigments in the mutant cell line. We expect this novel, mutant cell line will provide new tools for studying plastid development and differentiation.
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