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Sample records for cellular proliferation ultrastructure

  1. Cellular Ultrastructure and Crystal Development in Amorphophallus (Araceae)

    PubMed Central

    Prychid, Christina J.; Jabaily, Rachel Schmidt; Rudall, Paula J.

    2008-01-01

    Background and Aims Species of Araceae accumulate calcium oxalate in the form of characteristically grooved needle-shaped raphide crystals and multi-crystal druses. This study focuses on the distribution and development of raphides and druses during leaf growth in ten species of Amorphophallus (Araceae) in order to determine the crystal macropatterns and the underlying ultrastructural features associated with formation of the unusual raphide groove. Methods Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and both bright-field and polarized-light microscopy were used to study a range of developmental stages. Key Results Raphide crystals are initiated very early in plant development. They are consistently present in most species and have a fairly uniform distribution within mature tissues. Individual raphides may be formed by calcium oxalate deposition within individual crystal chambers in the vacuole of an idioblast. Druse crystals form later in the true leaves, and are absent from some species. Distribution of druses within leaves is more variable. Druses initially develop at leaf tips and then increase basipetally as the leaf ages. Druse development may also be initiated in crystal chambers. Conclusions The unusual grooved raphides in Amorphophallus species probably result from an unusual crystal chamber morphology. There are multiple systems of transport and biomineralization of calcium into the vacuole of the idioblast. Differences between raphide and druse idioblasts indicate different levels of cellular regulation. The relatively early development of raphides provides a defensive function in soft, growing tissues, and restricts build-up of dangerously high levels of calcium in tissues that lack the ability to adequately regulate calcium. The later development of druses could be primarily for calcium sequestration. PMID:18285357

  2. Quantification of Cellular Proliferation in Mouse Atherosclerotic Lesions.

    PubMed

    Fuster, José J

    2015-01-01

    Excessive cell proliferation within atherosclerotic plaques plays an important role in the progression of atherosclerosis. Macrophage proliferation in particular has become a major focus of attention in the cardiovascular field because it appears to mediate most of macrophage expansion in mouse atherosclerotic arteries. Therefore, quantification of cell proliferation is an essential part of the characterization of atherosclerotic plaques in experimental studies. This chapter describes two variants of a simple immunostaining protocol that allow for the quantification of cellular proliferation in mouse atherosclerotic lesions based on the detection of the proliferation-associated antigen Ki-67. PMID:26445791

  3. Advances in Light-based Imaging of Three-Dimensional Cellular Ultrastructure

    PubMed Central

    Kanchanawong, Pakorn; Waterman, Clare M.

    2012-01-01

    Visualization methods are key to gaining insights into cellular structure and function. Since diffraction has long confined optical microscopes to a resolution no better than hundreds of nanometers, the observation of ultrastructural features has traditionally been the domain of electron microscopes (EM). In the past decade, however, advances in super-resolution fluorescence microscopy have considerably expanded the capability of light-based imaging techniques. Advantages of fluorescent labeling such as high sensitivity, specificity, and multichannel capability, can now be exploited to dissect ultrastructural features of cells. With recent methods capable of imaging specific proteins with a resolution on the order of a few tens of nanometers in 3-dimensions, this has made it possible to elucidate the molecular organization of many complex cellular structures. PMID:22209239

  4. Cellular origin and ultrastructure of membranes induced during poliovirus infection.

    PubMed Central

    Schlegel, A; Giddings, T H; Ladinsky, M S; Kirkegaard, K

    1996-01-01

    Poliovirus RNA replicative complexes are associated with cytoplasmic membranous structures that accumulate during viral infection. These membranes were immunoisolated by using a monoclonal antibody against the viral nonstructural protein 2C. Biochemical analysis of the isolated membranes revealed that several organelles of the host cell (lysosomes, trans-Golgi stack and trans-Golgi network, and endoplasmic reticulum) contributed to the virus-induced membranous structures. Electron microscopy of infected cells preserved by high-pressure freezing revealed that the virus-induced membranes contain double lipid bilayers that surround apparently cytosolic material. Immunolabeling experiments showed that poliovirus proteins 2C and 3D were localized to the same membranes as the cellular markers tested. The morphological and biochemical data are consistent with the hypothesis that autophagy or a similar host process is involved in the formation of the poliovirus-induced membranes. PMID:8794292

  5. Cellular proliferation after experimental glaucoma filtration surgery

    SciTech Connect

    Jampel, H.D.; McGuigan, L.J.; Dunkelberger, G.R.; L'Hernault, N.L.; Quigley, H.A.

    1988-01-01

    We used light microscopic autoradiography to determine the time course of cellular incorporation of tritiated thymidine (a correlate of cell division) following glaucoma filtration surgery in seven eyes of four cynomolgus monkeys with experimental glaucoma. Incorporation of tritiated thymidine was detected as early as 24 hours postoperatively. Peak incorporation occurred five days postoperatively and had returned to baseline levels by day 11. Cells incorporating tritiated thymidine included keratocytes, episcleral cells, corneal and capillary endothelial cells, and conjunctival and corneal epithelial cells. Transmission electron microscopy was correlated with the autoradiographic results to demonstrate that fibroblasts were dividing on the corneoscleral margin. These findings have potential clinical implications for the use of antiproliferative agents after filtration surgery.

  6. Cellular Growth and Mitochondrial Ultrastructure of Leishmania (Viannia) braziliensis Promastigotes Are Affected by the Iron Chelator 2,2-Dipyridyl

    PubMed Central

    Mesquita-Rodrigues, Camila; Menna-Barreto, Rubem F. S.; Sabóia-Vahia, Leonardo; Da-Silva, Silvia A. G.; de Souza, Elen M.; Waghabi, Mariana C.; Cuervo, Patrícia; De Jesus, José B.

    2013-01-01

    multifactorial response that results in cellular collapse, starting with the interruption of cell proliferation and culminating in marked mitochondrial impairment in some parasites and their subsequent cell death, whereas others may survive and resume proliferating. PMID:24147167

  7. Cellular adhesion, proliferation and viability on conducting polymer substrates.

    PubMed

    del Valle, Luis J; Estrany, Francesc; Armelin, Elaine; Oliver, Ramón; Alemán, Carlos

    2008-12-01

    This work reports a comprehensive study about cell adhesion and proliferation on the surface of different electroactive substrates formed by pi-conjugated polymers. Biological assays were performed considering four different cellular lines: two epithelial and two fibroblasts. On the other hand, the electroactivity of the three conducting systems was determined in physiological conditions. Results indicate that the three substrates behave as a cellular matrix, even though compatibility with cells is larger for PPy and the 3-layered system. Furthermore, the three polymeric systems are electro-compatible with the cellular monolayers. PMID:18683167

  8. Effects of hypoxia on the proliferation, mineralization and ultrastructure of human periodontal ligament fibroblasts in vitro

    PubMed Central

    ZHANG, HAI-YUAN; LIU, RUI; XING, YONG-JUN; XU, PING; LI, YAN; LI, CHEN-JUN

    2013-01-01

    This study aimed to investigate the effects of hypoxia on the proliferation, mineralization and ultrastructure of human periodontal ligament fibroblasts (HPLFs) at various times in vitro in order to further study plateau-hypoxia-induced periodontal disease. HPLFs (fifth passage) cultured by the tissue culture method were assigned to the slight (5% O2), middle (2% O2), and severe hypoxia (1% O2) groups and the control (21% O2) group, respectively. At 12, 24, 48 and 72 h, the proliferation and alkaline phosphatase (ALP) activities were detected. The ultrastructure of the severe hypoxia group was observed. HPLFs grew more rapidly with an increase in the degree of hypoxia at 12 and 24 h, and significant levels of proliferation (P<0.05) were observed in the severe hypoxia group at 24 h. Cell growth was restrained with an increase in the degree of hypoxia at 48 and 72 h, and the restrictions were clear (P<0.05) in the middle and severe hypoxia groups. ALP activity was restrained with increasing hypoxia at each time point. The restrictions were marked (P<0.05) in the severe hypoxia group at 24 h and in the middle and severe hypoxia groups at 48 and 72 h. However, the restriction was more marked (P<0.05) in the severe hypoxia group at 72 h. An increase was observed in the number of mitochondria and rough endoplasmic reticula (RER), with slightly expanded but complete membrane structures, in the severe hypoxia group at 24 h. At 48 h, the number of mitochondria and RER decreased as the mitochondria increased in size. Furthermore, mitochondrial cristae appeared to be vague, and a RER structural disorder was observed. At 72 h, the number of mitochondria and RER decreased further when the mitochondrial cristae were broken, vacuolar degeneration occurred, and the RER particles were reduced while the number of lysosomes increased. HPLF proliferation and mineralization was restrained. Additionally, HPLF structure was broken for a relatively long period of time in the middle and

  9. Cellular proliferation, cellular viability, and biocompatibility of HA-ZnO composites.

    PubMed

    Saha, Naresh; Dubey, Ashutosh K; Basu, Bikramjit

    2012-01-01

    One of the important issues in the development of hydroxyapatite (HA)-based biomaterials is the prosthetic infection, which limits wider use of monolithic HA despite superior cellular response. Recently, we reported that ZnO addition to HA can induce bactericidal property. It is therefore important to assess how ZnO addition influences the cytotoxicity property and cell adhesion/proliferation on HA-ZnO composite surfaces in vitro. In the above perspective, the objective of this study is to investigate the cell type and material composition dependent cellular proliferation and viability of pressureless sintered HA-ZnO composites. The combination of cell viability data as well as morphological observations of cultured human osteoblast-like SaOS2 cells and mouse fibroblast L929 cells suggests that HA-ZnO composites containing 10 Wt % or lower ZnO exhibit the ability to support cell adhesion and proliferation. Both SaOS2 and L929 cells exhibit extensive multidirectional network of actin cytoskeleton and cell flattening on the lower ZnO containing (≤10 Wt %) HA-ZnO composites. The in vitro results illustrate how variation in ZnO content can influence significantly the cell vitality, as evaluated using MTT biochemical assay. Also, the critical statistical analysis reveals that ZnO addition needs to be carefully tailored to ensure good in vitro cytocompatibility. The underlying reasons for difference in biological properties are analyzed. It is suggested that surface wettability as well as dissolution of ZnO, both contribute to the observed differences in cellular viability and proliferation. PMID:22102555

  10. [ULTRASTRUCTURAL ORGANIZATION OF CELLULAR ELEMENTS AND INTERCELLULAR CONNECTIONS IN STATOCYSTS OF TERRESTRIAL PULMONARY SNAIL H. LUCORUM].

    PubMed

    Gorgiladze, G; Bukia, R; Kalandarishvili, E; Taktakishvili, A; Gelashvili, N; Davitashvili, M; Madjagaladze, N

    2016-03-01

    The organ of mollusc equilibrium - statocyst appears to be the analogue of acoustic-vestibular system in vertebrate animals. In terrestrial pulmonary snail the epithelial lining of statocyst cavity is created by two types of the cells - a small amount of large cells, provided with kinocilia of sensitive cells and considerably a large number of small supporting or inserted cells, covered with the microvilli. By means of transmission and scanning electron microscopy the ultrastructure and intercellular connections of these cells were studied. The sensitive cells have in a certain way structured cytoplasm, which consists of three layers: ectoplasm, granular layer and hyaloplasm. Myelin-like bodies having the granular, vesicular and drop-like formations in the centre appear to be the special structure of the cytoplasm. In the cytoplasm there are areas, saturated with electron dense glycogen granules. On the electronograms sometimes it is observed how the pinocytic vesicles in the supporting cells are created from the diverticulum of plasmatic membrane of sensitive cells. The boundary areas of plasmatic membrane of adjacent cells (sensitive cells with supporting or supporting cells with the support) are also characterized by the presence of specialized contacts, which are analogous to desmosomes in the epithelial tissues, as well as by the existence of cellular desmosomes, interdigitations. Numerous lacunas have been revealed in the intercellular space, which are connected by the thin tubules and ducts resulting in the formation of a complicated configuration of extensive system of communicating with each other lacunae, which have the exit in statocyst cavity. PMID:27119843

  11. Polo-like kinase, a novel marker for cellular proliferation.

    PubMed Central

    Yuan, J.; Hörlin, A.; Hock, B.; Stutte, H. J.; Rübsamen-Waigmann, H.; Strebhardt, K.

    1997-01-01

    PLK (polo-like kinase) belongs to a family of serine/threonine kinases and represents the human counterpart of polo in Drosophila melanogaster and of CDC5 in Saccharomyces cerevisiae. It is strongly involved in spindle formation and chromosome segregation during mitosis. We have shown previously that PLK mRNA expression correlates with the mitotic activity of cells and the prognosis of lung cancer patients. In this report, the level of PLK protein was analyzed using immunohistochemical techniques. PLK protein was found expressed in the nuclei of tumor cells from lung and breast cancer as well as in several tumor cell lines. Furthermore, in peripheral lymphocytes treated with phytohemagglutinin, elevated proliferative activity of the cells correlated with the up-regulation of PLK protein expression. In contrast, in U937 and HL-60 cells after induction of differentiation with phorbol ester, PLK immunostaining disappeared under conditions of terminal differentiation. Most of the PLK protein was found in the nucleus of proliferating cells with diffuse but distinct staining also in the cytoplasm. Taken together, high levels of PLK protein are associated with cellular proliferation. Combined with other proliferative and oncogene markers, PLK may be useful for improved prediction of the clinical prognosis of cancer patients and for early cancer diagnosis. Due to its activity late in the cell cycle, it may be a target for cancer chemotherapy. Images Figure 1 Figure 2 Figure 3 PMID:9094972

  12. Imaging Cellular Proliferation in Prostate Cancer with Positron Emission Tomography

    PubMed Central

    Jadvar, Hossein

    2015-01-01

    Prostate cancer remains a major public health problem worldwide. Imaging plays an important role in the assessment of disease at all its clinical phases, including staging, restaging after definitive therapy, evaluation of therapy response, and prognostication. Positron emission tomography with a number of biologically targeted radiotracers has been demonstrated to have potential diagnostic and prognostic utility in the various clinical phases of this prevalent disease. Given the remarkable biological heterogeneity of prostate cancer, one major unmet clinical need that remains is the non-invasive imaging-based characterization of prostate tumors. Accurate tumor characterization allows for image-targeted biopsy and focal therapy as well as facilitates objective assessment of therapy effect. PET in conjunction with radiotracers that track the thymidine salvage pathway of DNA synthesis may be helpful to fulfill this necessity. We review briefly the preclinical and pilot clinical experience with the two major cellular proliferation radiotracers, [18F]-3’-deoxy-3’-fluorothymidine and [18F]-2’-fluoro-5-methyl-1-beta-D-arabinofuranosyluracil in prostate cancer. PMID:27408885

  13. Effects of Selected Egyptian Honeys on the Cellular Ultrastructure and the Gene Expression Profile of Escherichia coli

    PubMed Central

    Elkhatib, Walid F.

    2016-01-01

    The purpose of this study was to: (i) evaluate the antibacterial activities of three Egyptian honeys collected from different floral sources (namely, citrus, clover, and marjoram) against Escherichia coli; (ii) investigate the effects of these honeys on bacterial ultrastructure; and (iii) assess the anti-virulence potential of these honeys, by examining their impacts on the expression of eight selected genes (involved in biofilm formation, quorum sensing, and stress survival) in the test organism. The minimum inhibitory concentration (MIC) of the honey samples against E. coli ATCC 8739 were assessed by the broth microdilution assay in the presence and absence of catalase enzyme. Impacts of the honeys on the cellular ultrastructure and the expression profiles of the selected genes of E. coli were examined using transmission electron microscopy (TEM) and quantitative real-time polymerase chain reaction (qPCR) analysis, respectively. The susceptibility tests showed promising antibacterial activities of all the tested honeys against E. coli. This was supported by the TEM observations, which revealed “ghost” cells lacking DNA, in addition to cells with increased vacuoles, and/or with irregular shrunken cytoplasm. Among the tested honeys, marjoram exhibited the highest total antibacterial activity and the highest levels of peroxide-dependent activity. The qPCR analysis showed that all honey-treated cells share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest. Our results indicate that some varieties of the Egyptian honey have the potential to be effective inhibitor and virulence modulator of E. coli via multiple molecular targets. PMID:26954570

  14. Effects of Selected Egyptian Honeys on the Cellular Ultrastructure and the Gene Expression Profile of Escherichia coli.

    PubMed

    Wasfi, Reham; Elkhatib, Walid F; Khairalla, Ahmed S

    2016-01-01

    The purpose of this study was to: (i) evaluate the antibacterial activities of three Egyptian honeys collected from different floral sources (namely, citrus, clover, and marjoram) against Escherichia coli; (ii) investigate the effects of these honeys on bacterial ultrastructure; and (iii) assess the anti-virulence potential of these honeys, by examining their impacts on the expression of eight selected genes (involved in biofilm formation, quorum sensing, and stress survival) in the test organism. The minimum inhibitory concentration (MIC) of the honey samples against E. coli ATCC 8739 were assessed by the broth microdilution assay in the presence and absence of catalase enzyme. Impacts of the honeys on the cellular ultrastructure and the expression profiles of the selected genes of E. coli were examined using transmission electron microscopy (TEM) and quantitative real-time polymerase chain reaction (qPCR) analysis, respectively. The susceptibility tests showed promising antibacterial activities of all the tested honeys against E. coli. This was supported by the TEM observations, which revealed "ghost" cells lacking DNA, in addition to cells with increased vacuoles, and/or with irregular shrunken cytoplasm. Among the tested honeys, marjoram exhibited the highest total antibacterial activity and the highest levels of peroxide-dependent activity. The qPCR analysis showed that all honey-treated cells share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest. Our results indicate that some varieties of the Egyptian honey have the potential to be effective inhibitor and virulence modulator of E. coli via multiple molecular targets. PMID:26954570

  15. Ultrastructure and molecular phylogeny of Calkinsia aureus: cellular identity of a novel clade of deep-sea euglenozoans with epibiotic bacteria

    PubMed Central

    2009-01-01

    Background The Euglenozoa is a large group of eukaryotic flagellates with diverse modes of nutrition. The group consists of three main subclades – euglenids, kinetoplastids and diplonemids – that have been confirmed with both molecular phylogenetic analyses and a combination of shared ultrastructural characteristics. Several poorly understood lineages of putative euglenozoans live in anoxic environments, such as Calkinsia aureus, and have yet to be characterized at the molecular and ultrastructural levels. Improved understanding of these lineages is expected to shed considerable light onto the ultrastructure of prokaryote-eukaryote symbioses and the associated cellular innovations found within the Euglenozoa and beyond. Results We collected Calkinsia aureus from core samples taken from the low-oxygen seafloor of the Santa Barbara Basin (580 – 592 m depth), California. These biflagellates were distinctively orange in color and covered with a dense array of elongated epibiotic bacteria. Serial TEM sections through individually prepared cells demonstrated that C. aureus shares derived ultrastructural features with other members of the Euglenozoa (e.g. the same paraxonemal rods, microtubular root system and extrusomes). However, C. aureus also possessed several novel ultrastructural systems, such as modified mitochondria (i.e. hydrogenosome-like), an "extrusomal pocket", a highly organized extracellular matrix beneath epibiotic bacteria and a complex flagellar transition zone. Molecular phylogenies inferred from SSU rDNA sequences demonstrated that C. aureus grouped strongly within the Euglenozoa and with several environmental sequences taken from low-oxygen sediments in various locations around the world. Conclusion Calkinsia aureus possesses all of the synapomorphies for the Euglenozoa, but lacks traits that are specific to any of the three previously recognized euglenozoan subgroups. Molecular phylogenetic analyses of C. aureus demonstrate that this lineage is

  16. Ultrastructural Characterization of Turnip Mosaic Virus-Induced Cellular Rearrangements Reveals Membrane-Bound Viral Particles Accumulating in Vacuoles

    PubMed Central

    Wan, Juan; Basu, Kaustuv; Mui, Jeannie; Vali, Hojatollah; Zheng, Huanquan

    2015-01-01

    ABSTRACT Positive-strand RNA [(+) RNA] viruses remodel cellular membranes to facilitate virus replication and assembly. In the case of turnip mosaic virus (TuMV), the viral membrane protein 6K2 plays an essential role in endomembrane alterations. Although 6K2-induced membrane dynamics have been widely studied by confocal microscopy, the ultrastructure of this remodeling has not been extensively examined. In this study, we investigated the formation of TuMV-induced membrane changes by chemical fixation and high-pressure freezing/freeze substitution (HPF/FS) for transmission electron microscopy at different times of infection. We observed the formation of convoluted membranes connected to rough endoplasmic reticulum (rER) early in the infection process, followed by the production of single-membrane vesicle-like (SMVL) structures at the midstage of infection. Both SMVL and double-membrane vesicle-like structures with electron-dense cores, as well as electron-dense bodies, were found late in the infection process. Immunogold labeling results showed that the vesicle-like structures were 6K2 tagged and suggested that only the SMVL structures were viral RNA replication sites. Electron tomography (ET) was used to regenerate a three-dimensional model of these vesicle-like structures, which showed that they were, in fact, tubules. Late in infection, we observed filamentous particle bundles associated with electron-dense bodies, which suggests that these are sites for viral particle assembly. In addition, TuMV particles were observed to accumulate in the central vacuole as membrane-associated linear arrays. Our work thus unravels the sequential appearance of distinct TuMV-induced membrane structures for viral RNA replication, viral particle assembly, and accumulation. IMPORTANCE Positive-strand RNA viruses remodel cellular membranes for different stages of the infection process, such as protein translation and processing, viral RNA synthesis, particle assembly, and virus

  17. Human Homolog of Drosophila Ariadne (HHARI) is a marker of cellular proliferation associated with nuclear bodies

    SciTech Connect

    Elmehdawi, Fatima; Wheway, Gabrielle; Szymanska, Katarzyna; Adams, Matthew; High, Alec S.; Johnson, Colin A.; Robinson, Philip A.

    2013-02-01

    HHARI (also known as ARIH1) is an ubiquitin-protein ligase and is the cognate of the E2, UbcH7 (UBE2L3). To establish a functional role for HHARI in cellular proliferation processes, we performed a reverse genetics screen that identified n=86/522 (16.5%) ubiquitin conjugation components that have a statistically significant effect on cell proliferation, which included HHARI as a strong hit. We then produced and validated a panel of specific antibodies that establish HHARI as both a nuclear and cytoplasmic protein that is expressed in all cell types studied. HHARI was expressed at higher levels in nuclei, and co-localized with nuclear bodies including Cajal bodies (p80 coilin, NOPP140), PML and SC35 bodies. We confirmed reduced cellular proliferation after ARIH1 knockdown with individual siRNA duplexes, in addition to significantly increased levels of apoptosis, an increased proportion of cells in G2 phase of the cell cycle, and significant reductions in total cellular RNA levels. In head and neck squamous cell carcinoma biopsies, there are higher levels of HHARI expression associated with increased levels of proliferation, compared to healthy control tissues. We demonstrate that HHARI is associated with cellular proliferation, which may be mediated through its interaction with UbcH7 and modification of proteins in nuclear bodies. -- Highlights: ► We produce and validate new antibody reagents for the ubiquitin-protein ligase HHARI. ► HHARI colocalizes with nuclear bodies including Cajal, PML and SC35 bodies. ► We establish new functions in cell proliferation regulation for HHARI. ► Increased HHARI expression associates with squamous cell carcinoma and proliferation.

  18. Functional ultrastructure of eggs and cellular organization of hexacanths of the cyclophyllidean cestode Thysanotaenia congolensis: a phylogenetic implication of obtained results.

    PubMed

    Świderski, Zdzisław; Miquel, Jordi; Conn, David Bruce

    2016-03-01

    The functional ultrastructure of eggs and cellular organization of hexacanths from gravid proglottids of Thysanotaenia congolensis, from black rats from Cape Verde, were examined by transmission electron microscopy. Mature eggs with fully formed hexacanths are grouped within parenchymatous capsules of gravid proglottids. Oncospheral envelopes surrounding mature hexacanths are reduced to a very thin membranous embryophore as their protective function is taken over by the parenchymatous capsules originating from the medullary parenchyma of immature proglottids and composed of three layers. Six major cell types are present: a bi-nucleate medullary centre; a six-nucleate U-shaped penetration gland; a second type of penetration gland; two neurosecretory-type nerve cells; about 30 somatic cells; and about 12 germinative cells. Present results on the functional ultrastructure of eggs and cellular organization of hexacanths support the phylogenetic distinction between T. congolensis and cestodes of the subfamily Anoplocephalinae. PMID:26689933

  19. A regional ultrastructural analysis of the cellular and synaptic architecture in the chinchilla cristae ampullares

    NASA Technical Reports Server (NTRS)

    Lysakowski, A.; Goldberg, J. M.

    1997-01-01

    The chinchilla crista ampullaris was studied in 10 samples, each containing 32 consecutive ultrathin sections of the entire neuroepithelium. Dissector methods were used to estimate the incidence of various synaptic features, and results were confirmed in completely reconstructed hair cells. There are large regional variations in cellular and synaptic architecture. Type I and type II hair cells are shorter, broader, and less densely packed in the central zone than in the intermediate and peripheral zones. Complex calyx endings are most common centrally. On average, there are 15-20 ribbon synapses and 25-30 calyceal invaginations in each type I hair cell. Synapses and invaginations are most numerous centrally. Central type II hair cells receive considerably fewer afferent boutons than do peripheral type II hair cells, but have similar numbers of ribbon synapses. The numbers are similar because central type II hair cells make more synapses with the outer faces of calyx endings and with individual afferent boutons. Most afferent boutons get one ribbon synapse. Boutons without ribbon synapses were only found peripherally, and boutons getting multiple synapses were most frequent centrally. Throughout the neuroepithelium, there is an average of three to four efferent boutons on each type II hair cell and calyx ending. Reciprocal synapses are rare. Most synaptic ribbons in type I hair cells are spherules; those in type II hair cells can be spherical or elongated and are particularly heterogeneous centrally. Consistent with the proposal that the crista is concentrically organized, the intermediate and peripheral zones are each similar in their cellular and synaptic architecture near the base and near the planum. An especially differentiated subzone may exist in the middle of the central zone.

  20. Tetraspanin CD9 modulates human lymphoma cellular proliferation via histone deacetylase activity

    SciTech Connect

    Herr, Michael J.; Longhurst, Celia M.; Baker, Benjamin; Homayouni, Ramin; Speich, Henry E.; Kotha, Jayaprakash; Jennings, Lisa K.

    2014-05-16

    Highlights: • CD9 is differentially expressed in human Burkitt’s lymphoma cells. • We found that CD9 expression promotes these cells proliferation. • CD9 expression also increases HDAC activity. • HDAC inhibition decreased both cell proliferation and importantly CD9 expression. • CD9 may dictate HDAC efficacy and play a role in HDAC regulation. - Abstract: Non-Hodgkin Lymphoma (NHL) is a type of hematological malignancy that affects two percent of the overall population in the United States. Tetraspanin CD9 is a cell surface protein that has been thoroughly demonstrated to be a molecular facilitator of cellular phenotype. CD9 expression varies in two human lymphoma cell lines, Raji and BJAB. In this report, we investigated the functional relationship between CD9 and cell proliferation regulated by histone deacetylase (HDAC) activity in these two cell lines. Introduction of CD9 expression in Raji cells resulted in significantly increased cell proliferation and HDAC activity compared to Mock transfected Raji cells. The increase in CD9–Raji cell proliferation was significantly inhibited by HDAC inhibitor (HDACi) treatment. Pretreatment of BJAB cells with HDAC inhibitors resulted in a significant decrease in endogenous CD9 mRNA and cell surface expression. BJAB cells also displayed decreased cell proliferation after HDACi treatment. These results suggest a significant relationship between CD9 expression and cell proliferation in human lymphoma cells that may be modulated by HDAC activity.

  1. Induction of sister chromatid exchanges and inhibition of cellular proliferation in vitro. I. Caffeine

    SciTech Connect

    Guglielmi, G.E.; Vogt, T.F.; Tice, R.R.

    1982-01-01

    While many agents have been examined for their ability to induce SCE's, complete dose-response information has often been lacking. We have reexamined the ability of one such compound - caffeine - to induce SCEs and also to inhibit cellular proliferation in human peripheral lymphocytes in vitro. An acute exposure to caffeine prior to the DNA synthetic period did not affect either SCE frequency or the rate of cellular proliferation. Chronic exposure to caffeine throughout the culture period lead to both a dose-dependent increase in SCEs (SCE/sub d/ or doubling dose = 2.4 mM; SCE/sub 10/ or the dose capable of inducing 10 SCE = 1.4 mM) and a dose-dependent inhibition of cellular proliferation (IC/sub 50/ or the 50% inhibition concentration = 2.6 mM). The relative proportion of first generation metaphase cells, an assessment of proliferative inhibiton, increased linearly with increasing caffeine concentrations. However, SCE frequency increased nonlinearly over the same range of caffeine concentrations. Examination of the ratio of nonsymmetrical to symmetrical SCEs in third generation metaphase cells indicated that caffeine induced SCEs in equal frequency in each of three successive generations. The dependency of SCE induction and cellular proliferative inhibition on caffeine's presence during the DNA synthetic period suggests that caffeine may act as an antimetabolite in normal human cells.

  2. [Cell signaling pathways interaction in cellular proliferation: Potential target for therapeutic interventionism].

    PubMed

    Valdespino-Gómez, Víctor Manuel; Valdespino-Castillo, Patricia Margarita; Valdespino-Castillo, Víctor Edmundo

    2015-01-01

    Nowadays, cellular physiology is best understood by analysing their interacting molecular components. Proteins are the major components of the cells. Different proteins are organised in the form of functional clusters, pathways or networks. These molecules are ordered in clusters of receptor molecules of extracellular signals, transducers, sensors and biological response effectors. The identification of these intracellular signaling pathways in different cellular types has required a long journey of experimental work. More than 300 intracellular signaling pathways have been identified in human cells. They participate in cell homeostasis processes for structural and functional maintenance. Some of them participate simultaneously or in a nearly-consecutive progression to generate a cellular phenotypic change. In this review, an analysis is performed on the main intracellular signaling pathways that take part in the cellular proliferation process, and the potential use of some components of these pathways as target for therapeutic interventionism are also underlined. PMID:25986976

  3. Three-dimensional mass density mapping of cellular ultrastructure by ptychographic X-ray nanotomography.

    PubMed

    Diaz, Ana; Malkova, Barbora; Holler, Mirko; Guizar-Sicairos, Manuel; Lima, Enju; Panneels, Valerie; Pigino, Gaia; Bittermann, Anne Greet; Wettstein, Larissa; Tomizaki, Takashi; Bunk, Oliver; Schertler, Gebhard; Ishikawa, Takashi; Wepf, Roger; Menzel, Andreas

    2015-12-01

    We demonstrate absolute quantitative mass density mapping in three dimensions of frozen-hydrated biological matter with an isotropic resolution of 180 nm. As model for a biological system we use Chlamydomonas cells in buffer solution confined in a microcapillary. We use ptychographic X-ray computed tomography to image the entire specimen, including the 18 μm-diameter capillary, thereby providing directly an absolute mass density measurement of biological matter with an uncertainty of about 6%. The resulting maps have sufficient contrast to distinguish cells from the surrounding ice and several organelles of different densities inside the cells. Organelles are identified by comparison with a stained, resin-embedded specimen, which can be compared with established transmission electron microscopy results. For some identified organelles, the knowledge of their elemental composition reduces the uncertainty of their mass density measurement down to 1% with values consistent with previous measurements of dry weight concentrations in thin cellular sections by scanning transmission electron microscopy. With prospects of improving the spatial resolution in the near future, we expect that the capability of non-destructive three-dimensional mapping of mass density in biological samples close to their native state becomes a valuable method for measuring the packing of organic matter on the nanoscale. PMID:26470812

  4. Effect of chronic low dose of methotrexate on cellular proliferation during spermatogenesis in rats.

    PubMed

    Saxena, A K; Dhungel, S; Bhattacharya, S; Jha, C B; Srivastava, A K

    2004-01-01

    This study was conducted to evaluate cellular proliferation of germinal and non-germinal elements of seminiferous tubules following continuous Day 1 to Day 17 exposure of methotrexate (12.5 microgram) in male rats. There was significant decrease in the diameter of seminiferous tubules (P < 0.10) followed by increase of interstitial space (P < 0.01). The size of various stages of primary, secondary spermatocytes, and spermatids was altered significantly compared to controls. Vacuolization/decondensation of "chromatin-mass" in spermatocytes changed from rounded to oval. The size of the Sertoli and Leydig cells were reduced significantly. Basement membrane at some places seems to be disrupted and thin in experimental testis. Methotrexate induced cytotoxicity on the proliferation of cellular contents of seminiferous tubules elucidating the mechanism of dose-dependent drug induced testicular damage during spermatogenesis. PMID:14660169

  5. Obesity and cancer: At the crossroads of cellular metabolism and proliferation

    PubMed Central

    O’Rourke, Robert W.

    2014-01-01

    Obesity is associated with an increased risk of cancer. The mechanisms underlying this association include but are not limited to increased systemic inflammation, an anabolic hormonal milieu, and adipocyte-cancer crosstalk, aberrant stimuli that conspire to promote neoplastic transformation. Cellular proliferation is uncoupled from nutrient availability in malignant cells, promoting tumor progression. Elucidation of the mechanisms underlying the obesity-cancer connection will lead to the development of novel metabolism-based agents for cancer prevention and treatment. PMID:25264328

  6. Long-term effect of PROLI/NO on cellular proliferation and phenotype after arterial injury.

    PubMed

    Bahnson, Edward S M; Vavra, Ashley K; Flynn, Megan E; Vercammen, Janet M; Jiang, Qun; Schwartz, Amanda R; Kibbe, Melina R

    2016-01-01

    Vascular interventions are associated with high failure rates from restenosis secondary to negative remodeling and neointimal hyperplasia. Periadventitial delivery of nitric oxide (NO) inhibits neointimal hyperplasia, preserving lumen patency. With the development of new localized delivery vehicles, NO-based therapies remain a promising therapeutic avenue for the prevention of restenosis. While the time course of events during neointimal development has been well established, a full characterization of the impact of NO donors on the cells that comprise the arterial wall has not been performed. Thus, the aim of our study was to perform a detailed assessment of proliferation, cellularity, inflammation, and phenotypic cellular modulation in injured arteries treated with the short-lived NO donor, PROLI/NO. PROLI/NO provided durable inhibition of neointimal hyperplasia for 6 months after arterial injury. PROLI/NO inhibited proliferation and cellularity in the media and intima at all of the time points studied. However, PROLI/NO caused an increase in adventitial proliferation at 2 weeks, resulting in increased cellularity at 2 and 8 weeks compared to injury alone. PROLI/NO promoted local protein S-nitrosation and increased local tyrosine nitration, without measurable systemic effects. PROLI/NO predominantly inhibited contractile smooth muscle cells in the intima and media, and had little to no effect on vascular smooth muscle cells or myofibroblasts in the adventitia. Finally, PROLI/NO caused a delayed and decreased leukocyte infiltration response after injury. Our results show that a short-lived NO donor exerts durable effects on proliferation, phenotype modulation, and inflammation that result in long-term inhibition of neointimal hyperplasia. PMID:26627935

  7. Acute lethal graft-versus-host disease stimulates cellular proliferation in the adult rat liver.

    PubMed

    Klein, R M; Clancy, J; Stuart, S

    1982-11-01

    The present investigation was designed to analyse the effects of acute lethal graft-versus-host disease (GVHD) in adult (DA x LEW)F1 rats on cellular proliferation within the liver. The influence of the host thymus on GVHD-induced proliferation was also assessed. From 1-28 days after initiation of GVHD [3H]thymidine ([3H]-TdR) was injected i.v. and rats were killed one hour later. Percentage labelled cells (LI) of periportal infiltrating cells (PIC), hepatocytes (H), and sinusoidal lining cells (SC) were counted. Mean values for control rats were 0.3 +/- 0.1% (H), 0.4 +/- 0.1% (SC) and 0.2 +/- 0.1% (PIC). GVHD rats demonstrated a significant increase in LI of PIC (days 1-21), SC (days 2-17) and H (days 2-17). Most labelled cells in PIC were large lymphocytes. Peak LI values were 7.0 +/- 1.0% PIC (day 17), 6.8 +/- 0.9% SC (day 17), and 5.2 +/- 0.9% H (day 7), with all cellular compartments returning to near normal LI values by day 28. Stimulation of cellular proliferation occurred in all three liver cell compartments in neonatally thymectomized (TXM) rats. The intensity of GVHD-induced cell proliferation was significantly decreased at day 7 in all compartments and PIC was dramatically decreased at day 21 in TXM-GVHD rats as compared to non-TXM-GVHD rats. It is hypothesized that the general stimulation of hepatocyte cell proliferation in GVHD is related to the secretion of lymphokines by primarily donor and secondarily host T cells in the periportal infiltrate. PMID:7172201

  8. Transferrin synthesis by small cell lung cancer cells acts as an autocrine regulator of cellular proliferation.

    PubMed Central

    Vostrejs, M; Moran, P L; Seligman, P A

    1988-01-01

    Since transferrin is required for cellular proliferation, we investigated transferrin synthesis by a small cell lung cancer line (NCI-H510) that survives in serum-free media without added transferrin. Immunoassays for human transferrin demonstrated that these cells contained immunoreactive human transferrin. Immunofluorescence studies showed that the protein is expressed on the surface of cells, presumably bound to transferrin receptor. Media conditioned by NCI-H510 cells support proliferation of human leukemic cells that would not survive in media lacking transferrin. [35S]Methionine incorporation documented transferrin synthesis by NCI-H510 cells as well as three other small cell lines. Transferrin synthesis by NCI-H510 cells increased more than 10-fold when cells entered active phases of the cell cycle, and this increase was seen before large increases in transferrin-receptor expression. Further experiments examining the effects of agents that affect iron metabolism show that the addition of transferrin-iron or hemin to the media is associated with a more rapid initial rate of proliferation and lower rates of transferrin synthesis than control cells. Gallium salts, which inhibit iron uptake, inhibited proliferation of these cells. If the cells recovered from this effect, transferrin synthesis remained greatly increased compared to control. We conclude that transferrin synthesis by these malignant cells is ultimately related to an iron requirement for cellular proliferation. It appears that this synthesized transferrin acts as part of an important autocrine mechanism permitting proliferation of these cells, and perhaps permitting tumor cell growth in vivo in areas not well vascularized. Images PMID:2839550

  9. Selective transcription and cellular proliferation induced by PDGF require histone deacetylase activity

    SciTech Connect

    Catania, Annunziata; Iavarone, Carlo; Carlomagno, Stella M.; Chiariello, Mario . E-mail: chiariel@unina.it

    2006-05-05

    Histone deacetylases (HDACs) are key regulatory enzymes involved in the control of gene expression and their inhibition by specific drugs has been widely correlated to cell cycle arrest, terminal differentiation, and apoptosis. Here, we investigated whether HDAC activity was required for PDGF-dependent signal transduction and cellular proliferation. Exposure of PDGF-stimulated NIH3T3 fibroblasts to the HDAC inhibitor trichostatin A (TSA) potently repressed the expression of a group of genes correlated to PDGF-dependent cellular growth and pro-survival activity. Moreover, we show that TSA interfered with STAT3-dependent transcriptional activity induced by PDGF. Still, neither phosphorylation nor nuclear translocation and DNA-binding in vitro and in vivo of STAT3 were affected by using TSA to interfere with PDGF stimulation. Finally, TSA treatment resulted in the suppression of PDGF-dependent cellular proliferation without affecting cellular survival of NIH3T3 cells. Our data indicate that inhibition of HDAC activity antagonizes the mitogenic effect of PDGF, suggesting that these drugs may specifically act on the expression of STAT-dependent, PDGF-responsive genes.

  10. Myocardin inhibits cellular proliferation by inhibiting NF-kappaB(p65)-dependent cell cycle progression.

    PubMed

    Tang, Ru-Hang; Zheng, Xi-Long; Callis, Thomas E; Stansfield, William E; He, Jiayin; Baldwin, Albert S; Wang, Da-Zhi; Selzman, Craig H

    2008-03-01

    We previously reported the importance of the serum response factor (SRF) cofactor myocardin in controlling muscle gene expression as well as the fundamental role for the inflammatory transcription factor NF-kappaB in governing cellular fate. Inactivation of myocardin has been implicated in malignant tumor growth. However, the underlying mechanism of myocardin regulation of cellular growth remains unclear. Here we show that NF-kappaB(p65) represses myocardin activation of cardiac and smooth muscle genes in a CArG-box-dependent manner. Consistent with their functional interaction, p65 directly interacts with myocardin and inhibits the formation of the myocardin/SRF/CArG ternary complex in vitro and in vivo. Conversely, myocardin decreases p65-mediated target gene activation by interfering with p65 DNA binding and abrogates LPS-induced TNF-alpha expression. Importantly, myocardin inhibits cellular proliferation by interfering with NF-kappaB-dependent cell-cycle regulation. Cumulatively, these findings identify a function for myocardin as an SRF-independent transcriptional repressor and cell-cycle regulator and provide a molecular mechanism by which interaction between NF-kappaB and myocardin plays a central role in modulating cellular proliferation and differentiation. PMID:18296632

  11. Locust cellular defense against infections: sites of pathogen clearance and hemocyte proliferation.

    PubMed

    Duressa, Tewodros Firdissa; Vanlaer, Ria; Huybrechts, Roger

    2015-01-01

    The locust cellular defense is mediated by hemocytes and hematopoietic tissue. In Locusta migratoria, the hemocytes and hematopoietic tissue mutually assist each other in clearing invading pathogens from circulation. A β-1, 3-glucan infection induces nodule formation and apoptotic, TUNEL positive, cells in the hematopoietic tissue and massive loss of hemocytes in the circulation, calling for instant proliferation of hemocytes and hematopoietic tissue cells to assure continued host cellular defense. As the locust hematopoietic tissue persists at the adult stage, it was originally designated as being the major source for the replenishment process. Revisiting post infection hemocyte proliferation, using immunofluorescence based tests for DNA synthesis and mitosis, evidenced the lack of β-1, 3-glucan induced cell proliferation in the hematopoietic tissue. Instead these tests identified the circulating hemocytes as the major source for hemocyte replenishment in the circulation. The hematopoietic tissue, however, undergoes a continuous, slow and infection independent regeneration, thereby accumulating potential phagocytes despite infection, and might serve a prophylactic role in containing pathogens in this swarming insect. PMID:25281274

  12. Silibinin Inhibits HIV-1 Infection by Reducing Cellular Activation and Proliferation

    PubMed Central

    McClure, Janela; Lovelace, Erica S.; Elahi, Shokrollah; Maurice, Nicholas J.; Wagoner, Jessica; Dragavon, Joan; Mittler, John E.; Kraft, Zane; Stamatatos, Leonidis; Horton, Helen; De Rosa, Stephen C.; Coombs, Robert W.; Polyak, Stephen J.

    2012-01-01

    Purified silymarin-derived natural products from the milk thistle plant (Silybum marianum) block hepatitis C virus (HCV) infection and inhibit T cell proliferation in vitro. An intravenous formulation of silibinin (SIL), a major component of silymarin, displays anti-HCV effects in humans and also inhibits T-cell proliferation in vitro. We show that SIL inhibited replication of HIV-1 in TZM-bl cells, PBMCs, and CEM cells in vitro. SIL suppression of HIV-1 coincided with dose-dependent reductions in actively proliferating CD19+, CD4+, and CD8+ cells, resulting in fewer CD4+ T cells expressing the HIV-1 co-receptors CXCR4 and CCR5. SIL inhibition of T-cell growth was not due to cytotoxicity measured by cell cycle arrest, apoptosis, or necrosis. SIL also blocked induction of the activation markers CD38, HLA-DR, Ki67, and CCR5 on CD4+ T cells. The data suggest that SIL attenuated cellular functions involved in T-cell activation, proliferation, and HIV-1 infection. Silymarin-derived compounds provide cytoprotection by suppressing virus infection, immune activation, and inflammation, and as such may be relevant for both HIV mono-infected and HIV/HCV co-infected subjects. PMID:22848626

  13. Ultrastructural features of the differentiating thyroid primordium in the sand lizard (Lacerta agilis L.) from the differentiation of the cellular cords to the formation of the follicular lumen.

    PubMed

    Rupik, Weronika; Kowalska, Magdalena; Swadźba, Elwira; Maślak, Robert

    2016-04-01

    The differentiation of the thyroid primordium of lacertilian species is poorly understood. The present study reports on the ultrastructural analysis of the developing thyroid primordium in the sand lizard (Lacerta agilis) during the early stages of differentiation. The early thyroid primordium of sand lizard embryos was composed of cellular cords that contained single cells with a giant lipid droplet, which were eliminated by specific autophagy (lipophagy). The follicular lumens at the periphery of the primordium differentiated even before the division of the cellular cords. When the single cells within the cords started to die through paraptosis, the adjacent cells started to polarise and junctional complexes began to form around them. After polarisation and clearing up after the formation of the lumens, the cellular cords divided into definitive follicles. The cellular cords in the central part of the primordium started to differentiate later than those at the periphery. The cellular cords divided into presumptive follicles first and only later differentiated into definitive follicles. During this process, a population of centrally located cells was removed through apoptosis to form the lumen. Although the follicular lumen in sand lizard embryos is differentiated by cavitation similar to that in the grass snake, there were very important differences during the early stages of the differentiation of the cellular cords and the formation of the thyroid follicles. PMID:26966051

  14. In vivo imaging of cellular proliferation in renal cell carcinoma using 18F-fluorothymidine PET

    PubMed Central

    Wong, Peter K.; Lee, Sze Ting; Murone, Carmel; Eng, John; Lawrentschuk, Nathan; Berlangieri, Salvatore U.; Pathmaraj, Kunthi; O’Keefe, Graeme J.; Sachinidis, John; Byrne, Amanda J.; Bolton, Damien M.; Davis, Ian D.; Scott, Andrew M.

    2014-01-01

    Objective(s): The ability to measure cellular proliferation non-invasively in renal cell carcinoma may allow prediction of tumour aggressiveness and response to therapy. The aim of this study was to evaluate the uptake of 18F-fluorothymidine (FLT) PET in renal cell carcinoma (RCC), and to compare this to 18F-fluorodeoxyglucose (FDG), and to an immunohistochemical measure of cellular proliferation (Ki-67). Methods: Twenty seven patients (16 male, 11 females; age 42-77) with newly diagnosed renal cell carcinoma suitable for resection were prospectively enrolled. All patients had preoperative FLT and FDG PET scans. Visual identification of tumour using FLT PET compared to normal kidney was facilitated by the use of a pre-operative contrast enhanced CT scan. After surgery tumour was taken for histologic analysis and immunohistochemical staining by Ki-67. Results: The SUVmax (maximum standardized uptake value) mean±SD for FLT in tumour was 2.59±1.27, compared to normal kidney (2.47±0.34). The mean SUVmax for FDG in tumour was similar to FLT (2.60±1.08). There was a significant correlation between FLT uptake and the immunohistochemical marker Ki-67 (r=0.72, P<0.0001) in RCC. Ki-67 proliferative index was mean ± SD of 13.3%±9.2 (range 2.2% - 36.3%). Conclusion: There is detectable uptake of FLT in primary renal cell carcinoma, which correlates with cellular proliferation as assessed by Ki-67 labelling index. This finding has relevance to the use of FLT PET in molecular imaging studies of renal cell carcinoma biology.

  15. Diffusion kurtosis imaging can efficiently assess the glioma grade and cellular proliferation

    PubMed Central

    Zhao, Lingyun; Zhang, Jiaxuan; Zhang, Shun; Yao, Yihao; Yang, Shiqi; Shi, Jingjing; Shen, Nanxi; Su, Changliang; Zhang, Ju; Zhu, Wenzhen

    2015-01-01

    Conventional diffusion imaging techniques are not sufficiently accurate for evaluating glioma grade and cellular proliferation, which are critical for guiding glioma treatment. Diffusion kurtosis imaging (DKI), an advanced non-Gaussian diffusion imaging technique, has shown potential in grading glioma; however, its applications in this tumor have not been fully elucidated. In this study, DKI and diffusion weighted imaging (DWI) were performed on 74 consecutive patients with histopathologically confirmed glioma. The kurtosis and conventional diffusion metric values of the tumor were semi-automatically obtained. The relationships of these metrics with the glioma grade and Ki-67 expression were evaluated. The diagnostic efficiency of these metrics in grading was further compared. It was demonstrated that compared with the conventional diffusion metrics, the kurtosis metrics were more promising imaging markers in distinguishing high-grade from low-grade gliomas and distinguishing among grade II, III and IV gliomas; the kurtosis metrics also showed great potential in the prediction of Ki-67 expression. To our best knowledge, we are the first to reveal the ability of DKI to assess the cellular proliferation of gliomas, and to employ the semi-automatic method for the accurate measurement of gliomas. These results could have a significant impact on the diagnosis and subsequent therapy of glioma. PMID:26544514

  16. Commonly consumed and specialty dietary mushrooms reduce cellular proliferation in MCF-7 human breast cancer cells.

    PubMed

    Martin, Keith R; Brophy, Sara K

    2010-11-01

    Worldwide, over one million women will be newly diagnosed with breast cancer in the next year. Moreover, breast cancer is the second leading cause of cancer death in the USA. An accumulating body of evidence suggests that consumption of dietary mushrooms can protect against breast cancer. In this study, we tested and compared the ability of five commonly consumed or specialty mushrooms to modulate cell number balance in the cancer process using MCF-7 human breast cancer cells. Hot water extracts (80°C for 2 h) of maitake (MT, Grifola frondosa), crimini (CRIM, Agaricus bisporus), portabella (PORT, Agaricus bisporus), oyster (OYS, Pleurotus ostreatus) and white button (WB, Agaricus bisporus) mushrooms or water alone (5% v/v) were incubated for 24 h with MCF-7 cells. Cellular proliferation determined by bromodeoxyuridine incorporation was significantly (P < 0.05) reduced up to 33% by all mushrooms, with MT and OYS being the most effective. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) reduction, an often used mitochondrion-dependent marker of proliferation, was unchanged although decreased (P > 0.05) by 15% with OYS extract. Lactate dehydrogenase release, as a marker of necrosis, was significantly increased after incubation with MT but not with other test mushrooms. Furthermore, MT extract significantly increased apoptosis, or programmed cell death, as determined by terminal deoxynucleotidyl end labeling method, whereas other test mushrooms displayed trends of ∼15%. The total numbers of cells per flask, determined by hemacytometry, were not different from control cultures. Overall, all test mushrooms significantly suppressed cellular proliferation, with MT further significantly inducing apoptosis and cytotoxicity in human breast cancer cells. This suggests that both common and specialty mushrooms may be chemoprotective against breast cancer. PMID:20921274

  17. Arecoline augments cellular proliferation in the prostate gland of male Wistar rats

    SciTech Connect

    Saha, Indraneel; Chatterjee, Aniruddha; Mondal, Anushree; Maiti, Bishwa Ranjan; Chatterji, Urmi

    2011-09-01

    Areca nut chewing is the fourth most popular habit in the world due to its effects as a mild stimulant, causing a feeling of euphoria and slightly heightened alertness. Areca nuts contain several alkaloids and tannins, of which arecoline is the most abundant and known to have several adverse effects in humans, specially an increased risk of oral cancer. On evaluating the effects of arecoline on the male endocrine physiology in Wistar rats, it was found that arecoline treatment led to an overall enlargement and increase in the wet weight of the prostate gland, and a two-fold increase in serum gonadotropin and testosterone levels. Since the prostate is a major target for testosterone, the consequences of arecoline consumption were studied specifically in the prostate gland. Arecoline treatment led to an increase in the number of rough endoplasmic reticulum and reduction of secretory vesicles, signifying a hyperactive state of the prostate. Increased expression of androgen receptors in response to arecoline allowed for enhanced effect of testosterone in the prostate of treated animals, which augmented cell proliferation, subsequently confirmed by an increase in the expression of Ki-67 protein. Cellular proliferation was also the outcome of concomitant over expression of the G{sub 1}-to-S cell cycle regulatory proteins, cyclin D1 and CDK4, both at the transcriptional and translational levels. Taken together, the findings provide the first evidence that regular use of arecoline may lead to prostatic hyperplasia and hypertrophy, and eventually to disorders associated with prostate enlargement. - Highlights: > Effect of arecoline was investigated on the endocrine physiology of male Wistar rats. > Increase observed in prostate size, wet weight, serum testosterone and gonadotropins. > Arecoline increased RER, expression of androgen receptor and cellular proliferation. > Upregulation of cyclin D1 and CDK4 seen at transcriptional and translational levels. > It may cause

  18. Modulation of 17β-Estradiol Signaling on Cellular Proliferation by Caveolin-2.

    PubMed

    Totta, Pierangela; Gionfra, Fabio; Busonero, Claudia; Acconcia, Filippo

    2016-06-01

    The sex hormone 17β-estradiol (E2) exerts pleiotropic effects by binding to the ligand-activated transcription factor estrogen receptor α (ERα). The E2:ERα complex regulates several physiological processes, including cell survival and proliferation, through transcriptional effects (i.e., estrogen responsive element [ERE]-based gene transcription) and non-transcriptional membrane-initiated effects (i.e., the activation of extra-nuclear signaling cascades), which derive from the activation of the pool of ERα that is localized to plasma membrane caveolae. Caveolae are ω-shaped membrane sub-domains that are composed of scaffold proteins named caveolins (i.e., caveolin-1, caveolin-2, and caveolin-3). Although caveolin-3 is exclusively expressed in muscles, caveolin-1 and caveolin-2 are co-expressed in all human tissues. From a functional point of view, caveolin-2 can operate both dependently on and independently of caveolin-1, which is the main coat component of caveolae. Interestingly, while a functional interplay between caveolin-1 and ERα has been reported in the control of E2-induced physiological effects, the role of caveolin-2 in E2:ERα signaling within the cell remains poorly understood. This study shows that siRNA-mediated caveolin-2 depletion in breast ductal carcinoma cells (MCF-7) reduces E2-induced ERα phosphorylation at serine residue 118 (S118), controls intracellular receptor levels, precludes ERα-mediated extra-nuclear activation of signaling pathways, reduces ERα transcriptional activity, and prevents cellular proliferation. Meanwhile, the impact of caveolin-1 depletion on ERα signaling in MCF-7 cells is shown to be similar to that elicited by siRNA-mediated caveolin-2 depletion. Altogether, these data demonstrate that caveolin-2 expression is necessary for the control of E2-dependent cellular proliferation. PMID:26480297

  19. Graphene Enhances Cellular Proliferation through Activating the Epidermal Growth Factor Receptor.

    PubMed

    Liu, Wei; Sun, Cheng; Liao, Chunyang; Cui, Lin; Li, Haishan; Qu, Guangbo; Yu, Wenlian; Song, Naining; Cui, Yuan; Wang, Zheng; Xie, Wenping; Chen, Huiming; Zhou, Qunfang

    2016-07-27

    Graphene has promising applications in food packaging, water purification, and detective sensors for contamination monitoring. However, the biological effects of graphene are not fully understood. It is necessary to clarify the potential risks of graphene exposure to humans through diverse routes, such as foods. In the present study, graphene, as the model nanomaterial, was used to test its potential effects on the cell proliferation based on multiple representative cell lines, including HepG2, A549, MCF-7, and HeLa cells. Graphene was characterized by Raman spectroscopy, particle size analysis, atomic force microscopy, and transmission electron microscopy. The cellular responses to graphene exposure were evaluated using flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and alamarBlue assays. Rat cerebral astrocyte cultures, as the non-cancer cells, were used to assess the potential cytotoxicity of graphene as well. The results showed that graphene stimulation enhanced cell proliferation in all tested cell cultures and the highest elevation in cell growth was up to 60%. A western blot assay showed that the expression of epidermal growth factor (EGF) was upregulated upon graphene treatment. The phosphorylation of EGF receptor (EGFR) and the downstream proteins, ShC and extracellular regulating kinase (ERK), were remarkably induced, indicating that the activation of the mitogen-activated protein kinase (MAPK)/ERK signaling pathway was triggered. The activation of PI3 kinase p85 and AKT showed that the PI3K/AKT signaling pathway was also involved in graphene-induced cell proliferation, causing the increase of cell ratios in the G2/M phase. No influences on cell apoptosis were observed in graphene-treated cells when compared to the negative controls, proving the low cytotoxicity of this emerging nanomaterial. The findings in this study revealed the potential cellular biological effect of graphene, which may give useful hints on its biosafety

  20. Ontogeny of the conus papillaris of the lizard Gallotia galloti and cellular response following transection of the optic nerve: an immunohistochemical and ultrastructural study.

    PubMed

    Alfayate, M C; Santos, E; Yanes, C; Casañas, N; Viñoly, R; Del Mar Romero-Alemán, Maria; Monzón-Mayor, Maximina

    2011-04-01

    Spontaneous regrowth of the axons of retinal ganglion cells (RGC) occurs after unilateral optic nerve transection (ONT) in the lizard Gallotia galloti. We have performed an immunohistochemical and ultrastructural study of the conus papillaris (CP) of this lizard during ontogeny and after ONT in order to characterize its cell subpopulations, innervation and putative blood-brain barrier (BBB) and to evaluate changes occurring throughout regeneration. Proliferating PCNA(+) cells were abundant between embryonic stage 33 (E33) and hatching. From E33, we observed Pax2(+)/GS(+) glial cells in the primitive CP, which became increasingly pigmented and vascularised from E35. Conal astrocytes coexpressing Pax2 with vimentin and/or GFAP were identified from E37-E38. GluT-1(+)/LEA(+)/Pax2(-) endothelial cells (ECs) formed a continuous endothelium with tight junctions and luminal and abluminal microfolds. In adults, the peripheral blood vessels showed a thinner calibre, stronger GluT-1 staining and more abundant microfolds than those of the central CP indicating the higher specialization involved during transport within the former. Occasional pericytes, abundant Pax2(+) pigment cells, LEA(+) microglia/macrophages, unmyelinated Tuj1(+) nerve fibres and SV2(+) synaptic vesicles were also observed in the perivascular zone. After ONT, the expression of GluT-1 and p75(NTR) persisted in ECs, suggesting the preservation/early recovery of the BBB. Relevant ultrastructural alterations were observed at 0.5 months postlesion, although, by 3 months, the CP had recovered the ultrastructure of controls indicating tissue recovery. Abnormal newly formed blood vessels had developed in the CP-optic nerve junction. Thus, the CP is a central nervous system structure whose regenerating capacity might be key for the nutritional support of regenerating RGCs in G. galloti. PMID:21347575

  1. [The ultrastructure of mixed mammary gland tumours in bitches. III. The early stages of the myoepithelial proliferation (author's transl)].

    PubMed

    von Bomhard, D; von Sandersleben, J

    1975-08-12

    The early stages of myoepithelial proliferation in 14 mixed canine mammary tumours were studied by light- and electron microscopy. Two different early stages can be distinguished: 1. Proliferations inside the basal lamina with partial maintenance of the organoid pattern. 2. Proliferations with a break through the basal lamina and transposition of tumour cells into the surrounding connective tissue. The intracytoplasmic fibrillae of myoepithelial tumour cells are striped periodically and thicker than those of normal myothelia. It is suggested that the amorphous as well as the fibrous intercellular substance in the early stages is derived from the described myoepithelial tumour cells. PMID:169622

  2. Structure and biochemical characterization of proliferating cellular nuclear antigen from a parasitic protozoon

    SciTech Connect

    Cardona-Felix, Cesar S.; Lara-Gonzalez, Samuel; Brieba, Luis G.

    2012-02-08

    Proliferating cellular nuclear antigen (PCNA) is a toroidal-shaped protein that is involved in cell-cycle control, DNA replication and DNA repair. Parasitic protozoa are early-diverged eukaryotes that are responsible for neglected diseases. In this work, a PCNA from a parasitic protozoon was identified, cloned and biochemically characterized and its crystal structure was determined. Structural and biochemical studies demonstrate that PCNA from Entamoeba histolytica assembles as a homotrimer that is able to interact with and stimulate the activity of a PCNA-interacting peptide-motif protein from E. histolytica, EhDNAligI. The data indicate a conservation of the biochemical mechanisms of PCNA-mediated interactions between metazoa, yeast and parasitic protozoa.

  3. CD10/NEP in non-small cell lung carcinomas. Relationship to cellular proliferation.

    PubMed Central

    Ganju, R K; Sunday, M; Tsarwhas, D G; Card, A; Shipp, M A

    1994-01-01

    The cell surface metalloproteinase CD10/neutral endopeptidase 24.11 (NEP) hydrolyzes a variety of peptide substrates and reduces cellular responses to specific peptide hormones. Because CD10/NEP modulates peptide-mediated proliferation of small cell carcinomas of the lung (SCLC) and normal fetal bronchial epithelium, we evaluated the enzyme's expression in non-small cell lung carcinomas (NSCLC). Bronchoalveolar and large cell carcinoma cell lines had low levels of CD10/NEP expression whereas squamous, adenosquamous, and adenocarcinoma cell lines had higher and more variable levels of the cell surface enzyme. Regional variations in CD10/NEP immunostaining in primary NSCLC specimens prompted us to correlate CD10/NEP expression with cell growth. In primary carcinomas of the lung, clonal NSCLC cell lines and SV40-transformed fetal airway epithelium, subsets of cells expressed primarily CD10/NEP or the proliferating cell nuclear antigen (PCNA). Cultured airway epithelial cells had the lowest levels of CD10/NEP expression when the highest percentage of cells were actively dividing; in addition, these cells grew more rapidly when cell surface CD10/NEP was inhibited. NSCLC cell lines had receptors for a variety of mitogenic peptides known to be CD10/NEP substrates, underscoring the functional significance of growth-related variability in CD10/NEP expression. Images PMID:7962523

  4. Human papillomavirus type 16 E7 perturbs DREAM to promote cellular proliferation and mitotic gene expression

    PubMed Central

    DeCaprio, James A.

    2014-01-01

    Study of the small DNA tumor viruses continues to provide valuable new insights into oncogenesis and fundamental biological processes. While much has already been revealed about how the human papillomaviruses (HPVs) can transform cells and contribute to cervical and oropharyngeal cancer, there clearly is much more to learn. In this issue of Oncogene, Pang et al. demonstrate that the high-risk HPV16 E7 oncogene can promote cellular proliferation by interacting with the DREAM (DP, RB-like, E2F and MuvB) complex at two distinct phases of the cell cycle (1). Consistent with earlier work, HPV16 E7 can bind to the retinoblastoma tumor suppressor (RB) family member p130 (RBL2) protein and promote its proteasome-mediated destruction thereby disrupting the DREAM complex and prevent exit from the cell cycle into quiescence. In addition, they demonstrate that HPV16 E7 can bind to MuvB core complex in association with BMYB and FOXM1 and activate gene expression during the G2 and M phase of the cell cycle. Thus, HPV16 E7 acts to prevent exit from the cell cycle entry and promotes mitotic proliferation and may account for the high levels of FOXM1 often observed in poor risk cervical cancers. PMID:24166507

  5. Human papillomavirus type 16 E7 perturbs DREAM to promote cellular proliferation and mitotic gene expression.

    PubMed

    DeCaprio, J A

    2014-07-31

    The study of the small DNA tumor viruses continues to provide valuable new insights into oncogenesis and fundamental biological processes. Although much has already been revealed about how the human papillomaviruses (HPVs) can transform cells and contribute to cervical and oropharyngeal cancer, there clearly is much more to learn. In this issue of Oncogene, Pang et al., doi:10.1038/onc.2013.426, demonstrate that the high-risk HPV16 E7 oncogene can promote cellular proliferation by interacting with the DREAM (DP, RB-like, E2F and MuvB) complex at two distinct phases of the cell cycle. Consistent with earlier work, HPV16 E7 can bind to the retinoblastoma tumor suppressor (RB) family member p130 (RBL2) protein and promote its proteasome-mediated destruction thereby disrupting the DREAM complex and can prevent exit from the cell cycle into quiescence. In addition, they demonstrate that HPV16 E7 can bind to MuvB core complex in association with BMYB and FOXM1 and activate gene expression during the G2 and M phase of the cell cycle. Thus, HPV16 E7 acts to prevent exit from the cell cycle entry and promotes mitotic proliferation and may account for the high levels of FOXM1 often observed in poor-risk cervical cancers. PMID:24166507

  6. Suppression of cellular proliferation and invasion by the concerted lipid and protein phosphatase activities of PTEN

    PubMed Central

    Davidson, Lindsay; Maccario, Helene; Perera, Nevin M.; Yang, Xuesong; Spinelli, Laura; Tibarewal, Priyanka; Glancy, Ben; Gray, Alex; Weijer, Cornelis J.; Downes, C. Peter; Leslie, Nick R.

    2009-01-01

    PTEN is a tumour suppressor with phosphatase activity in vitro against both lipids and proteins and other potential non-enzymatic mechanisms of action. Although the importance of PTEN’s lipid phosphatase activity in regulating the PI3K signalling pathway is recognised, the significance of PTEN’s other mechanisms of action is currently unclear. Here, we describe the systematic identification of a PTEN mutant, PTEN Y138L, with activity against lipid, but not soluble substrates. Using this mutant we provide evidence for the interfacial activation of PTEN against lipid substrates. We also show that when re-expressed at physiological levels in PTEN null U87MG glioblastoma cells the protein phosphatase activity of PTEN is not required to regulate cellular PtdInsP3 levels or the downstream protein kinase Akt/PKB. Finally, in 3D Matrigel cultures of U87MG cells similarly re-expressing PTEN mutants, both the protein and lipid phosphatase activities were required to inhibit invasion, but either activity alone significantly inhibited proliferation, albeit only weakly for the protein phosphatase activity. Our data provides a novel tool to address the significance of PTEN’s separable lipid and protein phosphatase activities and suggest that both activities act to suppress proliferation and act together to suppress invasion. PMID:19915616

  7. Effects of antibacterial mineral leachates on the cellular ultrastructure, morphology, and membrane integrity of Escherichia coli and methicillin-resistant Staphylococcus aureus

    PubMed Central

    2010-01-01

    Background We have previously identified two mineral mixtures, CB07 and BY07, and their respective aqueous leachates that exhibit in vitro antibacterial activity against a broad spectrum of pathogens. The present study assesses cellular ultrastructure and membrane integrity of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli after exposure to CB07 and BY07 aqueous leachates. Methods We used scanning and transmission electron microscopy to evaluate E. coli and MRSA ultrastructure and morphology following exposure to antibacterial leachates. Additionally, we employed Baclight LIVE/DEAD staining and flow cytometry to investigate the cellular membrane as a possible target for antibacterial activity. Results Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging of E. coli and MRSA revealed intact cells following exposure to antibacterial mineral leachates. TEM images of MRSA showed disruption of the cytoplasmic contents, distorted cell shape, irregular membranes, and distorted septa of dividing cells. TEM images of E. coli exposed to leachates exhibited different patterns of cytoplasmic condensation with respect to the controls and no apparent change in cell envelope structure. Although bactericidal activity of the leachates occurs more rapidly in E. coli than in MRSA, LIVE/DEAD staining demonstrated that the membrane of E. coli remains intact, while the MRSA membrane is permeabilized following exposure to the leachates. Conclusions These data suggest that the leachate antibacterial mechanism of action differs for Gram-positive and Gram-negative organisms. Upon antibacterial mineral leachate exposure, structural integrity is retained, however, compromised membrane integrity accounts for bactericidal activity in Gram-positive, but not in Gram-negative cells. PMID:20846374

  8. Effects of fractionated radiation on the brain vasculature in a murine model: Blood-brain barrier permeability, astrocyte proliferation, and ultrastructural changes

    SciTech Connect

    Yuan Hong; Gaber, M. Waleed . E-mail: wgaber@utmem.edu; Boyd, Kelli; Wilson, Christy M.; Kiani, Mohammad F.; Merchant, Thomas E.

    2006-11-01

    Purpose: Radiation therapy of CNS tumors damages the blood-brain barrier (BBB) and normal brain tissue. Our aims were to characterize the short- and long-term effects of fractionated radiotherapy (FRT) on cerebral microvasculature in mice and to investigate the mechanism of change in BBB permeability in mice. Methods and Materials: Intravital microscopy and a cranial window technique were used to measure BBB permeability to fluorescein isothiocyanate (FITC)-dextran and leukocyte endothelial interactions before and after cranial irradiation. Daily doses of 2 Gy were delivered 5 days/week (total, 40 Gy). We immunostained the molecules to detect the expression of glial fibrillary acidic protein and to demonstrate astrocyte activity in brain parenchyma. To relate the permeability changes to endothelial ultrastructural changes, we used electron microscopy. Results: Blood-brain barrier permeability did not increase significantly until 90 days after FRT, at which point it increased continuously until 180 days post-FRT. The number of adherent leukocytes did not increase during the study. The number of astrocytes in the cerebral cortex increased significantly; vesicular activity in endothelial cells increased beginning 90 days after irradiation, and most tight junctions stayed intact, although some were shorter and less dense at 120 and 180 days. Conclusions: The cellular and microvasculature response of the brain to FRT is mediated through astrogliosis and ultrastructural changes, accompanied by an increase in BBB permeability. The response to FRT is delayed as compared with single-dose irradiation treatment, and does not involve leukocyte adhesion. However, FRT induces an increase in the BBB permeability, as in the case of single-dose irradiation.

  9. Early lesions of Kaposi's sarcoma in homosexual men. An ultrastructural comparison with other vascular proliferations in skin.

    PubMed Central

    McNutt, N. S.; Fletcher, V.; Conant, M. A.

    1983-01-01

    An aggressive variant of Kaposi's sarcoma (KS) has appeared in young homosexual men with evidence of systemic immunosuppression. The ultrastructure in biopsy specimens from 8 KS cases in young homosexual men has been compared with that in biopsy specimens from 4 KS cases in elderly heterosexuals and with that in biopsy specimens from 23 cases of benign vascular disorders of skin. In all cases of KS the small blood vessels lacked a prominent investment of pericytes and their processes, had a fragmented and often absent basal lamina, had frequent discontinuities in the endothelial lining, and had only a few small junctional densities between endothelial cells. Some clinically aggressive cases of KS also had necrosis of individual endothelial cells and had prominent cytoplasmic processes entrapping individual collagen fibers. The benign disorders lacked these features. These differences in the structure of the small vessels may be of diagnostic value in some early cases of KS. The loss of dendritic pericytes in blood capillaries in KS might relate to the telangiectasia which is a prominent feature of the early lesions of KS. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:6301283

  10. III. Cellular ultrastructures in situ as key to understanding tumor energy metabolism: biological significance of the Warburg effect

    PubMed Central

    Witkiewicz, Halina

    2013-01-01

    Despite the universality of metabolic pathways, malignant cells were found to have their metabolism reprogrammed to generate energy by glycolysis even under normal oxygen concentrations (the Warburg effect). Therefore, the pathway energetically 18 times less efficient than oxidative phosphorylation was implicated to match increased energy requirements of growing tumors. The paradox was explained by an abnormally high rate of glucose uptake, assuming unlimited availability of substrates for tumor growth in vivo. However, ultrastructural analysis of tumor vasculature morphogenesis showed that the growing tissue regions did not have continuous blood supply and intermittently depended on autophagy for survival. Erythrogenic autophagy, and resulting ATP generation by glycolysis, appeared critical to initiating vasculature formation where it was missing. This study focused on ultrastructural features that reflected metabolic switch from aerobic to anaerobic. Morphological differences between and within different types of cells were evident in tissue sections. In cells undergoing nucleo-cytoplasmic conversion into erythrosomes (erythrogenesis), gradual changes led to replacing mitochondria with peroxisomes, through an intermediate form connected to endoplasmic reticulum. Those findings related to the issue of peroxisome biogenesis and to the phenomenon of hemogenic endothelium. Mitochondria were compacted also during mitosis. In vivo, cells that lost and others that retained capability to use oxygen coexisted side-by-side; both types were important for vasculature morphogenesis and tissue growth. Once passable, the new vasculature segment could deliver external oxygen and nutrients. Nutritional and redox status of microenvironment had similar effect on metabolism of malignant and non-malignant cells demonstrating the necessity to maintain structure-energy equivalence in all living cells. The role of glycolysis in initiating vasculature formation, and in progression of

  11. Growth hormone in vascular pathology: neovascularization and expression of receptors is associated with cellular proliferation.

    PubMed

    Lincoln, D T; Singal, P K; Al-Banaw, A

    2007-01-01

    were of the following pathological entities: Haemangioma (n = 12); haemangioendothelioma (n = 10); Castleman's disease (n = 3), haemangiopericytoma (n = 4); angiosarcoma, (n = 11), Kaposi's sarcoma with focal infiltration by lymphoma, HIV +ve (n = 7), Kaposi's sarcoma (n = 17). The endothelial cell marker CD-31 was used to establish endothelial cell characteristics and microvascular density. To delineate tumour cell growth, immunohistochemical analysis of cycling nuclear protein and of proliferating cell nuclear antigen, using Ki-67 and PCNA polyclonal antibodies respectively, was used to demonstrate proliferative indexes. Results show that, compared to their normal tissue counterparts, nuclear and cytoplasmic expression of GHR consistently result in strong receptor immunoreactivity in the highly malignant angiosarcomas and Kaposi's sarcomas and was localized in the cell membranes and cytoplasm, but strong nuclear immunoreactivity was also identified. The presence of intracellular GHR is the result of endoplasmic reticulum and Golgi localization. Nuclear localization is due to identical nuclear GHR-binding protein. Furthermore, there was a positive correlation of GHR immunoreactivity with neoplastic cellular proliferation and cycling, as measured by Ki-67 and PCNA. In conclusion, this study shows that GHR expression in vascular tumours is a function of malignancy and cancer progression. Malignant cells, which are highly expressive of the receptor, have a greater proliferation rate and thereby also higher survival rate compared to tumours expressing lower or minimal receptor level. The presence of GHR in endothelial cells of vascular neoplasm indicates that they are target cells and GH is of importance in the proliferation of vascular tumour angiogenesis. GH is necessary not only for differentiation of progenitor cells, but also for their subsequent clonal expansion and maintenance. The results support the hypothesis that GH is involved in the paracrine

  12. Surfactant tuning of hydrophilicity of porous degradable copolymer scaffolds promotes cellular proliferation and enhances bone formation.

    PubMed

    Yassin, Mohammed A; Leknes, Knut N; Sun, Yang; Lie, Stein A; Finne-Wistrand, Anna; Mustafa, Kamal

    2016-08-01

    Poly(l-lactide-co-ɛ-caprolactone) (poly(LLA-co-CL)) has been blended with Tween 80 to tune the material properties and optimize cell-material interactions. Accordingly, the aims of this study were fourfold: to evaluate the effect of low concentrations of Tween 80 on the surface microstructure of 3D poly(LLA-co-CL) porous scaffolds: to determine the effect of different concentrations of Tween 80 on proliferation of bone marrow stromal cells (BMSCs) in vitro under dynamic cell culture at 7 and 21 days; to assess the influence of Tween 80 on the degradation rate of poly(LLA-co-CL) at 7 and 21 days; and in a subcutaneous rat model, to evaluate the effect on bone formation of porous scaffolds modified with 3% Tween 80 at 2 and 8 weeks. Blending 3% (w/w) Tween 80 with poly(LLA-co-CL) improves the surface wettability (p < 0.001). Poly(LLA-co-CL)/3% Tween 80 shows significantly increased cellular proliferation at days 7 and 21 (p < 0.001). Moreover, the presence of Tween 80 facilitates the degradation of poly(LLA-co-CL). Two weeks post-implantation, the poly(LLA-co-CL)/3% Tween 80 scaffolds exhibit significant mRNA expression of Runx2 (p = 0.004). After 8 weeks, poly(LLA-co-CL)/3% Tween 80 scaffolds show significantly increased de novo bone formation, demonstrated by μ-CT (p = 0.0133) and confirmed histologically. It can be concluded that blending 3% (w/w) Tween 80 with poly (LLA-co-CL) improves the hydrophilicity and osteogenic potential of the scaffolds. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2049-2059, 2016. PMID:27086867

  13. Cellular Uptake and Ultrastructural Localization Underlie the Pro-apoptotic Activity of a Hydrocarbon-stapled BIM BH3 Peptide.

    PubMed

    Edwards, Amanda L; Wachter, Franziska; Lammert, Margaret; Huhn, Annissa J; Luccarelli, James; Bird, Gregory H; Walensky, Loren D

    2015-09-18

    Hydrocarbon stapling has been applied to restore and stabilize the α-helical structure of bioactive peptides for biochemical, structural, cellular, and in vivo studies. The peptide sequence, in addition to the composition and location of the installed staple, can dramatically influence the properties of stapled peptides. As a result, constructs that appear similar can have distinct functions and utilities. Here, we perform a side-by-side comparison of stapled peptides modeled after the pro-apoptotic BIM BH3 helix to highlight these principles. We confirm that replacing a salt-bridge with an i, i + 4 hydrocarbon staple does not impair target binding affinity and instead can yield a biologically and pharmacologically enhanced α-helical peptide ligand. Importantly, we demonstrate by electron microscopy that the pro-apoptotic activity of a stapled BIM BH3 helix correlates with its capacity to achieve cellular uptake without membrane disruption and accumulate at the organellar site of mechanistic activity. PMID:26151238

  14. Cellular and molecular changes associated with competence acquisition during passion fruit somatic embryogenesis: ultrastructural characterization and analysis of SERK gene expression.

    PubMed

    Rocha, Diego Ismael; Pinto, Daniela Lopes Paim; Vieira, Lorena Melo; Tanaka, Francisco André Ossamu; Dornelas, Marcelo Carnier; Otoni, Wagner Campos

    2016-03-01

    The integration of cellular and molecular data is essential for understanding the mechanisms involved in the acquisition of competence by plant somatic cells and the cytological changes that underlie this process. In the present study, we investigated the dynamics and fate of Passiflora edulis Sims cotyledon explants that were committed to somatic embryogenesis by characterizing the associated ultrastructural events and analysing the expression of a putative P. edulis ortholog of the Somatic Embryogenesis Receptor-like Kinase (SERK) gene. Embryogenic calli were obtained from zygotic embryo explants cultured on Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid and 6-benzyladenine. Callus formation was initiated by the division of cells derived from the protodermal and subprotodermal cells on the abaxial side of the cotyledons. The isodiametric protodermal cells of the cotyledon explants adopted a columnar shape and became meristematic at the onset of PeSERK expression, which was not initially detected in explant cells. Therefore, we propose that these changes represent the first observable steps towards the acquisition of a competent state within this regeneration system. PeSERK expression was limited to the early stages of somatic embryogenesis; the expression of this gene was confined to proembryogenic zones and was absent in the embryos after the globular stage. Our data also demonstrated that the dynamics of the mobilization of reserve compounds correlated with the differentiation of the embryogenic callus. PMID:26008651

  15. LED illumination effects on proliferation and survival of meningioma cellular cultures

    NASA Astrophysics Data System (ADS)

    Solarte, Efrain; Urrea, Hernan; Criollo, William; Gutierrez, Oscar

    2010-02-01

    Meningioma cell cultures were prepared from frozen cell samples in 96 wells culture plates. Semiconductor light sources (LED) in seven different wavelength ranges were used to illuminate the wells, three different irradiation doses were selected per LED. Control cultures using three different concentrations of FBS were processed for comparison. Cell proliferation, viability, and cytotoxicity were measured every 24 hours for 6 days, using the XTT colorimetric assay (RocheR). None of the irradiated cultures exhibit cytotoxicity; but some of them exhibit proliferation inhibition. The larger proliferation was detected at a 0.05J/cm2 dose, for all LEDs; but for the orange and violet LEDs generated the bigger proliferation rate was measured. Results show the improvement of meningioma cell proliferation using illumination in some given wavelength ranges.

  16. ROLE OF CELLULAR BIOENERGETICS IN SMOOTH MUSCLE CELL PROLIFERATION INDUCED BY PLATELET-DERIVED GROWTH FACTOR

    PubMed Central

    Perez, Jessica; Hill, Bradford G.; Benavides, Gloria A.; Dranka, Brian P.; Darley-Usmar, Victor M.

    2013-01-01

    SYNOPSIS Abnormal smooth muscle cell proliferation is a hallmark of vascular disease. Although growth factors are known to contribute to cell hyperplasia, the changes in metabolism associated with this response, particularly mitochondrial respiration, remain unclear. Given the increased energy requirements for proliferation, we hypothesized that platelet-derived growth factor (PDGF) would stimulate glycolysis and mitochondrial respiration and that this elevated bioenergetic capacity is required for smooth muscle cell hyperplasia. To test this hypothesis, cell proliferation, glycolytic flux, and mitochondrial oxygen consumption were measured after treatment of primary rat aortic smooth muscle cells with PDGF. PDGF increased basal and maximal rates of glycolytic flux and mitochondrial oxygen consumption; enhancement of these bioenergetic pathways led to a substantial increase in the mitochondrial reserve capacity. Interventions with the PI3K inhibitor LY-294002 or the glycolysis inhibitor 2-deoxy-D-glucose abrogated PDGF-stimulated proliferation and prevented augmentation of glycolysis and mitochondrial reserve capacity. Similarly, when L-glucose was substituted for D-glucose, PDGF-dependent proliferation was abolished, as were changes in glycolysis and mitochondrial respiration. Interestingly, lactate dehydrogenase protein levels and activity were significantly increased after PDGF treatment. Moreover, L-lactate substitution for D-glucose was sufficient for increasing the mitochondrial reserve capacity and cell proliferation after treatment with PDGF; these effects were inhibited by the lactate dehydrogenase inhibitor, oxamate. These data suggest that glycolysis, by providing substrates that enhance the mitochondrial reserve capacity, plays an essential role in PDGF-induced cell proliferation, underscoring the integrated metabolic response required for proliferation of VSMC in the diseased vasculature. PMID:20331438

  17. Fish oil supplementation associated with decreased cellular degeneration and increased cellular proliferation 6 weeks after middle cerebral artery occlusion in the rat.

    PubMed

    Pascoe, Michaela C; Howells, David W; Crewther, David P; Carey, Leeanne M; Crewther, Sheila G

    2015-01-01

    Anti-inflammatory long-chain omega-3 polyunsaturated fatty acids (n-3-LC-PUFAs) are both neuroprotective and have antidepressive effects. However the influence of dietary supplemented n-3-LC-PUFAs on inflammation-related cell death and proliferation after middle cerebral artery occlusion (MCAo)-induced stroke is unknown. We have previously demonstrated that anxiety-like and hyperactive locomotor behaviors are reduced in n-3-LC-PUFA-fed MCAo animals. Thus in the present study, male hooded Wistar rats were exposed to MCAo or sham surgeries and examined behaviorally 6 weeks later, prior to euthanasia and examination of lesion size, cell death and proliferation in the dentate gyrus, cornu ammonis region of the hippocampus of the ipsilesional hemispheres, and the thalamus of the ipsilesional and contralesional hemispheres. Markers of cell genesis and cell degeneration in the hippocampus or thalamus of the ipsilesional hemisphere did not differ between surgery and diet groups 6 weeks post MCAo. Dietary supplementation with n-3-LC-PUFA decreased cell degeneration and increased cell proliferation in the thalamic region of the contralesional hemisphere. MCAo-associated cell degeneration in the hippocampus and thalamus positively correlated with anxiety-like and hyperactive locomotor behaviors previously reported in these animals. These results suggest that anti-inflammatory n-3-LC-PUFA supplementation appears to have cellular protective effects after MCAo in the rat, which may affect behavioral outcomes. PMID:25609971

  18. Fish oil supplementation associated with decreased cellular degeneration and increased cellular proliferation 6 weeks after middle cerebral artery occlusion in the rat

    PubMed Central

    Pascoe, Michaela C; Howells, David W; Crewther, David P; Carey, Leeanne M; Crewther, Sheila G

    2015-01-01

    Anti-inflammatory long-chain omega-3 polyunsaturated fatty acids (n-3-LC-PUFAs) are both neuroprotective and have antidepressive effects. However the influence of dietary supplemented n-3-LC-PUFAs on inflammation-related cell death and proliferation after middle cerebral artery occlusion (MCAo)-induced stroke is unknown. We have previously demonstrated that anxiety-like and hyperactive locomotor behaviors are reduced in n-3-LC-PUFA-fed MCAo animals. Thus in the present study, male hooded Wistar rats were exposed to MCAo or sham surgeries and examined behaviorally 6 weeks later, prior to euthanasia and examination of lesion size, cell death and proliferation in the dentate gyrus, cornu ammonis region of the hippocampus of the ipsilesional hemispheres, and the thalamus of the ipsilesional and contralesional hemispheres. Markers of cell genesis and cell degeneration in the hippocampus or thalamus of the ipsilesional hemisphere did not differ between surgery and diet groups 6 weeks post MCAo. Dietary supplementation with n-3-LC-PUFA decreased cell degeneration and increased cell proliferation in the thalamic region of the contralesional hemisphere. MCAo–associated cell degeneration in the hippocampus and thalamus positively correlated with anxiety-like and hyperactive locomotor behaviors previously reported in these animals. These results suggest that anti-inflammatory n-3-LC-PUFA supplementation appears to have cellular protective effects after MCAo in the rat, which may affect behavioral outcomes. PMID:25609971

  19. Depolarization of Cellular Resting Membrane Potential Promotes Neonatal Cardiomyocyte Proliferation In Vitro

    PubMed Central

    Lan, Jen-Yu; Williams, Corin; Levin, Michael; Black, Lauren Deems

    2014-01-01

    Cardiomyocytes (CMs) undergo a rapid transition from hyperplastic to hypertrophic growth soon after birth, which is a major challenge to the development of engineered cardiac tissue for pediatric patients. Resting membrane potential (Vmem) has been shown to play an important role in cell differentiation and proliferation during development. We hypothesized that depolarization of neonatal CMs would stimulate or maintain CM proliferation in vitro. To test our hypothesis, we isolated postnatal day 3 neonatal rat CMs and subjected them to sustained depolarization via the addition of potassium gluconate or Ouabain to the culture medium. Cell density and CM percentage measurements demonstrated an increase in mitotic CMs along with a ~2 fold increase in CM numbers with depolarization. In addition, depolarization led to an increase in cells in G2 and S phase, indicating increased proliferation, as measured by flow cytometry. Surprisingly depolarization of Vmem with either treatment led to inhibition of proliferation in cardiac fibroblasts. This effect is abrogated when the study was carried out on postnatal day 7 neonatal CMs, which are less proliferative, indicating that the likely mechanism of depolarization is the maintenance of the proliferating CM population. In summary, our findings suggest that depolarization maintains postnatal CM proliferation and may be a novel approach to encourage growth of engineered tissue and cardiac regeneration in pediatric patients. PMID:25295125

  20. Glutathione and the rate of cellular proliferation determine tumour cell sensitivity to tumour necrosis factor in vivo.

    PubMed Central

    Obrador, E; Navarro, J; Mompo, J; Asensi, M; Pellicer, J A; Estrela, J M

    1997-01-01

    Low rates of cellular proliferation are associated with low GSH content and enhanced sensitivity of Ehrlich ascites-tumour (EAT) cells to the cytotoxic effects of recombinant human tumour necrosis factor (rhTNF-alpha). Buthionine sulphoximine, a selective inhibitor of GSH synthesis, inhibited tumour growth and increased rhTNF-alpha cytoxicity in vitro. Administration of sublethal doses (10(6)units/kg per day) of rhTNF-alpha to EAT-bearing mice promoted oxidative stress (as measured by increases in intracellular peroxide levels, O2(-); generation and mitochondrial GSSG) and resulted in a slight reduction (19%) in tumour cell number when controls showed the highest rate of cellular proliferation. ATP (1mmol/kg per day)-induced selective GSH depletion, when combined with rhTNF-alpha administration, afforded a 61% inhibition of tumour growth and resulted in a significant extension of host survival. Administration of N-acetylcysteine (1mmol/kg per day) or GSH ester (5mmol/kg per day) abolished the rhTNF-alpha- and ATP-induced effects on tumour growth by maintaining high GSH levels in the cancer cells. Our results demonstrate that the sensitivity of tumour cells to rhTNF-alpha in vivo depends on their GSH content and their rate of proliferation. PMID:9224645

  1. Induction of vascular endothelial phenotype and cellular proliferation from human cord blood stem cells cultured in simulated microgravity

    NASA Astrophysics Data System (ADS)

    Chiu, Brian; Z-M Wan, Jim; Abley, Doris; Akabutu, John

    2005-05-01

    Recent studies have demonstrated that stem cells derived from adult hematopoietic tissues are capable of trans-differentiation into non-hematopoietic cells, and that the culture in microgravity ( μg) may modulate the proliferation and differentiation. We investigated the application of μg to human umbilical cord blood stem cells (CBSC) in the induction of vascular endothelial phenotype expression and cellular proliferation. CD34+ mononuclear cells were isolated from waste human umbilical cord blood samples and cultured in simulated μg for 14 days. The cells were seeded in rotary wall vessels (RWV) with or without microcarrier beads (MCB) and vascular endothelial growth factor was added during culture. Controls consisted of culture in 1 G. The cell cultures in RWV were examined by inverted microscopy. Cell counts, endothelial cell and leukocyte markers performed by flow-cytometry and FACS scan were assayed at days 1, 4, 7 and at the termination of the experiments. Culture in RWV revealed significantly increased cellular proliferation with three-dimensional (3D) tissue-like aggregates. At day 4, CD34+ cells cultured in RWV bioreactor without MCB developed vascular tubular assemblies and exhibited endothelial phenotypic markers. These data suggest that CD34+ human umbilical cord blood progenitors are capable of trans-differentiation into vascular endothelial cell phenotype and assemble into 3D tissue structures. Culture of CBSC in simulated μg may be potentially beneficial in the fields of stem cell biology and somatic cell therapy.

  2. AMPKα1 deficiency promotes cellular proliferation and DNA damage via p21 reduction in mouse embryonic fibroblasts

    PubMed Central

    Xu, Hairong; Zhou, Yanhong; Coughlan, Kathleen A.; Ding, Ye; Wang, Shaobin; Wu, Yue; Song, Ping; Zou, Ming-Hui

    2014-01-01

    Emerging evidence suggests that activation of adenosine monophosphate-activated protein kinase (AMPK), an energy gauge and redox sensor, controls the cell cycle and protects against DNA damage. However, the molecular mechanisms by which AMPKα isoform regulates DNA damage remain largely unknown. The aim of this study was to determine if AMPKα deletion contributes to cellular hyperproliferation by reducing p21WAF1/Cip1 (p21) expression thereby leading to accumulated DNA damage. The markers for DNA damage, cell cycle proteins, and apoptosis were monitored in cultured mouse embryonic fibroblasts (MEFs) isolated from wild type (WT, C57BL/6J), AMPKα1, or AMPKα2 homozygous deficient (AMPKα1−/−, AMPKα2−/−) mice by Western blot, flow cytometry, and cellular immunofluorescence staining. Deletion of AMPKα1, the predominant AMPKα isoform, but not AMPKα2 in immortalized MEFs led to spontaneous DNA double-strand breaks (DSB) which corresponded to repair protein p53-binding protein1 (53BP1) foci formation and subsequent apoptosis. Furthermore, AMPKα1 localizes to chromatin and AMPKα1 deletion down-regulates cyclin-dependent kinase inhibitor, p21, an important protein that plays a role in decreasing the incidence of spontaneous DSB via inhibition of cell proliferation. In addition, AMPKα1 null cells exhibited enhanced cell proliferation. Finally, p21 overexpression partially blocked the cellular hyperproliferation of AMPKα1-deleted MEFs via the inhibition of cyclin-dependent kinase 2 (CDK2). Taken together, our results suggest that AMPKα1 plays a fundamental role in controlling the cell cycle thereby affecting DNA damage and cellular apoptosis. PMID:25307521

  3. Modulation of Estrogen Response Element-Driven Gene Expressions and Cellular Proliferation with Polar Directions by Designer Transcription Regulators

    PubMed Central

    Muyan, Mesut; Güpür, Gizem; Yaşar, Pelin; Ayaz, Gamze; User, Sırma Damla; Kazan, Hasan Hüseyin; Huang, Yanfang

    2015-01-01

    Estrogen receptor α (ERα), as a ligand-dependent transcription factor, mediates 17β-estradiol (E2) effects. ERα is a modular protein containing a DNA binding domain (DBD) and transcription activation domains (AD) located at the amino- and carboxyl-termini. The interaction of the E2-activated ERα dimer with estrogen response elements (EREs) of genes constitutes the initial step in the ERE-dependent signaling pathway necessary for alterations of cellular features. We previously constructed monomeric transcription activators, or monotransactivators, assembled from an engineered ERE-binding module (EBM) using the ERα-DBD and constitutively active ADs from other transcription factors. Monotransactivators modulated cell proliferation by activating and repressing ERE-driven gene expressions that simulate responses observed with E2-ERα. We reasoned here that integration of potent heterologous repression domains (RDs) into EBM could generate monotransrepressors that alter ERE-bearing gene expressions and cellular proliferation in directions opposite to those observed with E2-ERα or monotransactivators. Consistent with this, monotransrepressors suppressed reporter gene expressions that emulate the ERE-dependent signaling pathway. Moreover, a model monotransrepressor regulated DNA synthesis, cell cycle progression and proliferation of recombinant adenovirus infected ER-negative cells through decreasing as well as increasing gene expressions with polar directions compared with E2-ERα or monotransactivator. Our results indicate that an ‘activator’ or a ‘repressor’ possesses both transcription activating/enhancing and repressing/decreasing abilities within a chromatin context. Offering a protein engineering platform to alter signal pathway-specific gene expressions and cell growth, our approach could also be used for the development of tools for epigenetic modifications and for clinical interventions wherein multigenic de-regulations are an issue. PMID:26295471

  4. Subcellular taxonomy: An ultrastructural classification system with diagnostic applications

    SciTech Connect

    McLay, A.L.C.; Toner, P.G.

    1985-01-01

    Contents of this work include: Ultrastructure, Nomenclature, and Disease; Numerical Listing: YX Cellular and Subcellular Structure; Alphabetical Listing; and Appendix: Proposed Revised Listing of M-6 Codes.

  5. New melanogenesis and photobiological processes in activation and proliferation of precursor melanocytes after UV-exposure: ultrastructural differentiation of precursor melanocytes from Langerhans cells

    SciTech Connect

    Jimbow, K.; Uesugi, T.

    1982-02-01

    Photobiological processes involving new melanogenesis after exposure to ultraviolet (UV) light were experimentally studied in C57 black adult mice by histochemistry, cytochemistry, and autoradiography. The trunk and the plantar region of the foot, where no functioning melanocytes were present before exposure, were exposed to UV-A for 14 consecutive days. Both regions revealed a basically similar pattern for new melanogenesis which involved an activation of precursor melanocytes. Essentially all of ''indeterminate'' cells appeared to be precursor melanocytes, the fine structure of which could be differentiated even from poorly developed Langerhans cells. New melanogenesis was manifested by 4 stages of cellular and subcellular reactions of these cells as indicated by histochemistry of dihydroxyphenylalanine (dopa) and autoradiography of thymidine incorporation: (a) an initial lag in the activation of precursor melanocytes with development of Golgi cisternae and rough endoplasmic reticulum followed by formation of unmelanized melanosomes (day 0 to 2); (b) synthesis of active tyrosinase accumulated in Golgi cisternae and vesicles with subsequent formation of melanized melanosomes in these cells (day 3 to 5); (c) mitotic proliferation of many of these activated cells, followed by an exponential increase of new melanocytes (day 6 to 7); and (d) melanosome transfer with differentiation of 10 nm filaments and arborization of dendrites, but without any significant change in the melanocyte population (day 8 to 14). The melanosome transfer was, however, not obvious until after 7 days of exposure. The size of newly synthesized melanosomes was similar to that of tail skin where native melanocytes were present before exposure.

  6. 14-3-3σ regulates keratinocyte proliferation and differentiation by modulating Yap1 cellular localization

    PubMed Central

    Sambandam, Sumitha A.T.; Kasetti, Ramesh Babu; Xue, Lei; Dean, Douglas C.; Lu, Qingxian; Li, Qiutang

    2015-01-01

    The homozygous repeated epilation (Er/Er) mouse mutant of the gene encoding 14-3-3σ displays an epidermal phenotype characterized by hyperproliferative keratinocytes and undifferentiated epidermis. Heterozygous Er/+ mice develop spontaneous skin tumors and are highly sensitive to tumor-promoting DMBA/TPA induction. The molecular mechanisms underlying 14-3-3σ regulation of epidermal proliferation, differentiation, and tumor formation have not been well elucidated. In the present study, we found that Er/Er keratinocytes failed to sequester Yap1 in the cytoplasm, leading to its nuclear localization during epidermal development in vivo and under differentiation-inducing culture conditions in vitro. In addition, enhanced Yap1 nuclear localization was also evident in DMBA/TPA-induced tumors from Er/+ skin. Furthermore, shRNA knockdown of Yap1 expression in Er/Er keratinocytes inhibited their proliferation, suggesting that YAP1 functions as a downstream effector of 14-3-3σ controlling epidermal proliferation. We then demonstrated that keratinocytes express all seven 14-3-3 protein isoforms, some of which form heterodimers with 14-3-3σ, either full-length WT or the mutant form found in Er/Er mice. However Er 14-3-3σ does not interact with Yap1, as demonstrated by co-immunoprecipitation. We conclude that Er 14-3-3σ disrupts the interaction between 14-3-3 and Yap1, thus fails to block Yap1 nuclear transcriptional function, causing continued progenitor expansion and inhibition of differentiation in Er/Er epidermis. PMID:25668240

  7. Artesunate attenuates glioma proliferation, migration and invasion by affecting cellular mechanical properties.

    PubMed

    Lian, Shizhong; Shi, Ruyi; Huang, Xun; Hu, Xiaoling; Song, Bin; Bai, Yinshan; Yang, Bin; Dong, Jinyao; Du, Zhijie; Zhang, Yanyan; Jia, Junmei; Ma, Ning; Guo, Geng; Wang, Mingyu

    2016-08-01

    Glioma is one of the most common malignant brain tumors. Current chemotherapy is far from providing satisfactory clinical outcomes for patients with glioma. More efficient drugs are urgently needed. Artesunate (ART) is clinically used as an anti-malarial agent and exhibits potent antiproliferative activity as a traditional Chinese medicine. In addition, ART has been shown to exert a profound cytotoxic effect on various tumor cell lines, presenting a novel candidate for cancer chemotherapy. However, its anticancer effect on glioma by altering cell biomechanical properties remains unclear. The present study aimed to identify the anticancer effects of ART on human glioma SHG44 cells by assessing cell proliferation, migration/invasion, the expression of claudin-1 and the biomechanical properties of ART-treated SHG44 cells. The proliferation of the SHG44 cells was assessed by MTT assay. The cell apoptosis was detected by flow cytometry. For cell migration and invasion assays, the Transwell was used. The expression of the gene claudin-1 was detected by polymerase chain reaction. The cell membrane and biomechanical properties, as targets of ART action, were investigated by atomic force microscopy (AFM). ART significantly inhibited the proliferation of SHG44 cells in a dose- and time-dependent manner. After treatment with 30 mg/l ART, the level of cell apoptosis was significantly increased (from 6.88±0.062 to 23.7±4.16%). Furthermore, the cell migration and invasion abilities of the SHG44 cells were markedly inhibited after treatment with 30 mg/l ART. Compared with the control group (0 mg/l ART), the SHG44 cells treated with 30 mg/l ART exhibited upregulated expression of claudin-1, increased adhesive force (from 2,400±300 to 3,600±500 pN), increased high connection among SHG44 cells, increased cytomembrane roughness (from 0.118±0.011 to 0.269±0.015 µm) and reduced elasticity (from 23±8 to 3.5±1.1 MPa). The present study demonstrated that ART could

  8. Annexin A1 sustains tumor metabolism and cellular proliferation upon stable loss of HIF1A

    PubMed Central

    Grimm, Christina; Lin, Suling J.; Wappler, Jessica; Klinger, Bertram; Blüthgen, Nils; Du Bois, Ilona; Schmeck, Bernd; Lehrach, Hans; de Graauw, Marjo; Goncalves, Emanuel; Saez-Rodriguez, Julio; Tan, Patrick; Grabsch, Heike I.; Prigione, Alessandro; Kempa, Stefan; Cramer, Thorsten

    2016-01-01

    Despite the approval of numerous molecular targeted drugs, long-term antiproliferative efficacy is rarely achieved and therapy resistance remains a central obstacle of cancer care. Combined inhibition of multiple cancer-driving pathways promises to improve antiproliferative efficacy. HIF-1 is a driver of gastric cancer and considered to be an attractive target for therapy. We noted that gastric cancer cells are able to functionally compensate the stable loss of HIF-1α. Via transcriptomics we identified a group of upregulated genes in HIF-1α-deficient cells and hypothesized that these genes confer survival upon HIF-1α loss. Strikingly, simultaneous knock-down of HIF-1α and Annexin A1 (ANXA1), one of the identified genes, resulted in complete cessation of proliferation. Using stable isotope-resolved metabolomics, oxidative and reductive glutamine metabolism was found to be significantly impaired in HIF-1α/ANXA1-deficient cells, potentially explaining the proliferation defect. In summary, we present a conceptually novel application of stable gene inactivation enabling in-depth deconstruction of resistance mechanisms. In theory, this experimental approach is applicable to any cancer-driving gene or pathway and promises to identify various new targets for combination therapies. PMID:26760764

  9. Annexin A1 sustains tumor metabolism and cellular proliferation upon stable loss of HIF1A.

    PubMed

    Rohwer, Nadine; Bindel, Fabian; Grimm, Christina; Lin, Suling J; Wappler, Jessica; Klinger, Bertram; Blüthgen, Nils; Du Bois, Ilona; Schmeck, Bernd; Lehrach, Hans; de Graauw, Marjo; Goncalves, Emanuel; Saez-Rodriguez, Julio; Tan, Patrick; Grabsch, Heike I; Prigione, Alessandro; Kempa, Stefan; Cramer, Thorsten

    2016-02-01

    Despite the approval of numerous molecular targeted drugs, long-term antiproliferative efficacy is rarely achieved and therapy resistance remains a central obstacle of cancer care. Combined inhibition of multiple cancer-driving pathways promises to improve antiproliferative efficacy. HIF-1 is a driver of gastric cancer and considered to be an attractive target for therapy. We noted that gastric cancer cells are able to functionally compensate the stable loss of HIF-1α. Via transcriptomics we identified a group of upregulated genes in HIF-1α-deficient cells and hypothesized that these genes confer survival upon HIF-1α loss. Strikingly, simultaneous knock-down of HIF-1α and Annexin A1 (ANXA1), one of the identified genes, resulted in complete cessation of proliferation. Using stable isotope-resolved metabolomics, oxidative and reductive glutamine metabolism was found to be significantly impaired in HIF-1α/ANXA1-deficient cells, potentially explaining the proliferation defect. In summary, we present a conceptually novel application of stable gene inactivation enabling in-depth deconstruction of resistance mechanisms. In theory, this experimental approach is applicable to any cancer-driving gene or pathway and promises to identify various new targets for combination therapies. PMID:26760764

  10. Altered control of cellular proliferation in the absence of mammalian brahma (SNF2alpha).

    PubMed

    Reyes, J C; Barra, J; Muchardt, C; Camus, A; Babinet, C; Yaniv, M

    1998-12-01

    The mammalian SWI-SNF complex is an evolutionarily conserved, multi-subunit machine, involved in chromatin remodelling during transcriptional activation. Within this complex, the BRM (SNF2alpha) and BRG1 (SNF2beta) proteins are mutually exclusive subunits that are believed to affect nucleosomal structures using the energy of ATP hydrolysis. In order to characterize possible differences in the function of BRM and BRG1, and to gain further insights into the role of BRM-containing SWI-SNF complexes, the mouse BRM gene was inactivated by homologous recombination. BRM-/- mice develop normally, suggesting that an observed up-regulation of the BRG1 protein can functionally replace BRM in the SWI-SNF complexes of mutant cells. Nonetheless, adult mutant mice were approximately 15% heavier than control littermates. This may be caused by increased cell proliferation, as demonstrated by a higher mitotic index detected in mutant livers. This is supported further by the observation that mutant embryonic fibroblasts were significantly deficient in their ability to arrest in the G0/G1 phase of the cell cycle in response to cell confluency or DNA damage. These studies suggest that BRM participates in the regulation of cell proliferation in adult mice. PMID:9843504

  11. Role of EGF receptor ligands in TCDD-induced EGFR down-regulation and cellular proliferation.

    PubMed

    Campion, Christina M; Leon Carrion, Sandra; Mamidanna, Gayatri; Sutter, Carrie Hayes; Sutter, Thomas R; Cole, Judith A

    2016-06-25

    In cultures of normal human epidermal keratinocytes (NHEKs), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces the expression of the epidermal growth factor receptor ligands transforming growth factor-α (TGF-α) and epiregulin (EREG). TCDD also down-regulates EGF receptors (EGFR), suggesting that decreases in signaling contribute to the effects of TCDD. In this study, we treated post-confluent NHEKs with 10 nM TCDD and assessed its effects on EGFR binding, EGFR ligand secretion, basal ERK activity, and proliferation. TCDD caused time-dependent deceases in [(125)I]-EGF binding to levels 78% of basal cell values at 72 h. Amphiregulin (AREG) levels increased with time in culture in basal and TCDD-treated cells, while TGF-α and epiregulin (EREG) secretion were stimulated by TCDD. Inhibiting EGFR ligand release with the metalloproteinase inhibitor batimastat prevented EGFR down-regulation and neutralizing antibodies for AREG and EREG relieved receptor down-regulation. In contrast, neutralizing TGF-α intensified EGFR down-regulation. Treating NHEKs with AREG or TGF-α caused rapid internalization of receptors with TGF-α promoting recycling within 90 min. EREG had limited effects on rapid internalization or recycling. TCDD treatment increased ERK activity, a response reduced by batimastat and the neutralization of all three ligands indicating that the EGFR and its ligands maintain ERK activity. All three EGFR ligands were required for the maintenance of total cell number in basal and TCDD-treated cultures. The EGFR inhibitor PD1530305 blocked basal and TCDD-induced increases in the number of cells labeled by 5-ethynyl-2'-deoxyuridine, identifying an EGFR-dependent pool of proliferating cells that is larger in TCDD-treated cultures. Overall, these data indicate that TCDD-induced EGFR down-regulation in NHEKs is caused by AREG, TGF-α, and EREG, while TGF-α enhances receptor recycling to maintain a pool of EGFR at the cell surface. These receptors are required for

  12. Dysfunctional telomeres induce p53-dependent and independent apoptosis to compromise cellular proliferation and inhibit tumor formation.

    PubMed

    Wang, Yang; Wang, Xinwei; Flores, Elsa R; Yu, Jian; Chang, Sandy

    2016-08-01

    Aging is associated with progressive telomere shortening, resulting in the formation of dysfunctional telomeres that compromise tissue proliferation. However, dysfunctional telomeres can limit tumorigenesis by activating p53-dependent cellular senescence and apoptosis. While activation of both senescence and apoptosis is required for repress tumor formation, it is not clear which pathway is the major tumor suppressive pathway in vivo. In this study, we generated Eμ-myc; Pot1b(∆/∆) mouse to directly compare tumor formation under conditions in which either p53-dependent apoptosis or senescence is activated by telomeres devoid of the shelterin component Pot1b. We found that activation of p53-dependent apoptosis plays a more critical role in suppressing lymphoma formation than p53-dependent senescence. In addition, we found that telomeres in Pot1b(∆/∆) ; p53(-/-) mice activate an ATR-Chk1-dependent DNA damage response to initiate a robust p53-independent, p73-dependent apoptotic pathway that limited stem cell proliferation but suppressed B-cell lymphomagenesis. Our results demonstrate that in mouse models, both p53-dependent and p53-independent apoptosis are important to suppressing tumor formation. PMID:27113195

  13. IL-6 Trans-signaling-STAT3 Pathway Mediates ECM and Cellular Proliferation in Fibroblasts from Hypertrophic Scar

    PubMed Central

    Ray, Sutapa; Ju, Xiaoxi; Sun, Hong; Finnerty, Celeste C; Herndon, David N; Brasier, Allan R

    2012-01-01

    The molecular mechanisms behind the pathogenesis of post-burn hypertrophic scar (HS) remain unclear. Here, we investigate the role of interleukin-6 (IL-6) trans-signaling-STAT3 pathway in HS fibroblasts (HSF) derived from burned-induced HS skin. HSF showed increased Tyr 705 STAT3 phosphorylation over normal fibroblast (NF) after IL-6•IL-6Rα stimulation by immunoassays. The endogenous STAT3 target gene, SOCS3, was upregulated in HSF and showed increased STAT3 binding on its promoter relative to NF in Chromatin Immunoprecipitation assay. We observed that the cell surface signaling transducer glycoprotein 130 is upregulated in HSF using Q-RT-PCR and flow cytometry. The production of excessive extracellular matrix (ECM), including the expression of alpha2 (1) procollagen (Col1A2) and fibronectin 1 (FN) were seen in HSFs. A STAT3 peptide inhibitor abrogated FN and Col1A2 gene expression in HSF indicating involvement of STAT3 in ECM production. The cellular proliferation markers Cyclin D1, Bcl-Xl and c-Myc were also upregulated in HSF and knockdown of STAT3 by siRNA attenuated c-Myc expression indicating the essential role of STAT3 in fibroblast proliferation. Taken together, our results suggest that the IL-6-trans-signaling-STAT3 pathway may play an integral role in HS pathogenesis and disruption of this pathway could be a potential therapeutic strategy for the treatment of burn-induced HS. PMID:23303450

  14. TRPV1 mediates cellular uptake of anandamide and thus promotes endothelial cell proliferation and network-formation

    PubMed Central

    Hofmann, Nicole A.; Barth, Sonja; Waldeck-Weiermair, Markus; Klec, Christiane; Strunk, Dirk; Malli, Roland; Graier, Wolfgang F.

    2014-01-01

    ABSTRACT Anandamide (N-arachidonyl ethanolamide, AEA) is an endogenous cannabinoid that is involved in various pathological conditions, including cardiovascular diseases and tumor-angiogenesis. Herein, we tested the involvement of classical cannabinoid receptors (CBRs) and the Ca2+-channel transient receptor potential vanilloid 1 (TRPV1) on cellular AEA uptake and its effect on endothelial cell proliferation and network-formation. Uptake of the fluorescence-labeled anandamide (SKM4-45-1) was monitored in human endothelial colony-forming cells (ECFCs) and a human endothelial-vein cell line (EA.hy926). Involvement of the receptors during AEA translocation was determined by selective pharmacological inhibition (AM251, SR144528, CID16020046, SB366791) and molecular interference by TRPV1-selective siRNA-mediated knock-down and TRPV1 overexpression. We show that exclusively TRPV1 contributes essentially to AEA transport into endothelial cells in a Ca2+-independent manner. This TRPV1 function is a prerequisite for AEA-induced endothelial cell proliferation and network-formation. Our findings point to a so far unknown moonlighting function of TRPV1 as Ca2+-independent contributor/regulator of AEA uptake. We propose TRPV1 as representing a promising target for development of pharmacological therapies against AEA-triggered endothelial cell functions, including their stimulatory effect on tumor-angiogenesis. PMID:25395667

  15. (18)F-FLT PET imaging of cellular proliferation in pancreatic cancer.

    PubMed

    Lamarca, Angela; Asselin, Marie-Claude; Manoharan, Prakash; McNamara, Mairéad G; Trigonis, Ioannis; Hubner, Richard; Saleem, Azeem; Valle, Juan W

    2016-03-01

    Pancreatic ductal adenocarcinoma is known for its poor prognosis. Since the development of computerized tomography, magnetic resonance and endoscopic ultrasound, novel imaging techniques have struggled to get established in the management of patients diagnosed with pancreatic adenocarcinoma for several reasons. Thus, imaging assessment of pancreatic cancer remains a field with scope for further improvement. In contrast to cross-sectional anatomical imaging methods, molecular imaging modalities such as positron emission tomography (PET) can provide information on tumour function. Particularly, tumour proliferation may be assessed by measurement of intracellular thymidine kinase 1 (TK1) activity level using thymidine analogues radiolabelled with a positron emitter for use with PET. This approach, has been widely explored with [(18)F]-fluoro-3'-deoxy-3'-l-fluorothymidine ((18)F-FLT) PET. This manuscript reviews the rationale and physiology behind (18)F-FLT PET imaging, with special focus on pancreatic cancer and other gastrointestinal malignancies. Potential benefit and challenges of this imaging technique for diagnosis, staging and assessment of treatment response in abdominal malignancies are discussed. PMID:26778585

  16. Biological effects of near-infrared lasers on fibroblast cellular differentiation, proliferation and contraction

    NASA Astrophysics Data System (ADS)

    Acquaviva, Joseph T.; Chen, Wei R.; Vaughan, Melville B.

    2013-02-01

    Combining near infrared (NIR) laser irradiation into a tumor treatment therapy has shown promising results. For a comprehensive tumor therapy, it is important to understand the effects of NIR irradiation not only on the tumor, but on the tumor stroma as well. The composition of the microenvironment present near the tumor cells is critical to the phenotype of the tumor. Fibroblasts affect tissue homeostasis and change the microenvironment surrounding the tumor. Myofibroblast are derived from fibroblast cells, and in some cases indicate the transformation of healthy tissue into malignant tissue. Wound healing environments are rich in fibroblast cells and are similar to tumor stromas. To simulate a tumor stroma a wound healing environment was constructed. Two different human fibroblast cells were cultured in collagen lattices. Specifically, collagen lattices were created, with type 1 collagen, incubated for 5 days and irradiated with a 980nm laser on the 4th day. The subsequent collagen lattices were either released and measured, or fixed for immunostaining on the 5th day; the contraction rates also were analyzed. Furthermore, collagen lattices were stained to identify fibroblast proliferation and differentiation, into myofibroblasts. The results suggested NIR laser irradiation had some biological effects on the fibroblast cells, but the full extent of the effects is still unclear.

  17. Cellular proliferation and infiltration following interstitial irradiation of normal dog brain is altered by an inhibitor of polyamine synthesis

    SciTech Connect

    Fike, J.R.; Gobbel, G.T.; Chou, D.

    1995-07-15

    The objectives of this study were to quantitatively define proliferative and infiltrative cell responses after focal {sup 125}I irradiation of normal brain, and to determine the effects of an intravenous infusion of {alpha}-defluoromethylornithine (DFMO) on those responses. Adult beagle dogs were irradiated using high activity {sup 125}I sources. Cellular responses were quantified using a histomorphometric analysis. After radiation alone, cellular events included a substantial acute inflammatory response followed by increased BrdU labeling and progressive increases in numbers of capillaries and astrocytes. {alpha}-Difluoromethylornithine treatment significantly affected the measured cell responses. As in controls, an early inflammatory response was measured, but after 2 weeks there were more PMNs/unit area than in controls. The onset of measurable BrdU labeling was delayed in DFMO-treated animals, and the magnitude of labeling was significantly reduced. Increases in astrocyte and vessel numbers/mm{sup 2} were observed after a 2-week delay. At the site of implant, astrocytes from DFMO-treated dogs were significantly smaller than those from controls. There is substantial cell proliferation and infiltration in response to interstitial irradiation of normal brain, and these responses are significantly altered by DFMO treatment. Although the precise mechanisms by which DFMO exerts its effects in this model are not known, the results from this study suggest that modification of radiation injury may be possible by manipulating the response of normal cells to injury. 57 refs., 6 figs.

  18. BRCA1 Haploinsufficiency Leads to Altered Expression of Genes Involved in Cellular Proliferation and Development

    PubMed Central

    Feilotter, Harriet E.; Michel, Claire; Uy, Paolo; Bathurst, Lauren; Davey, Scott

    2014-01-01

    The assessment of BRCA1 and BRCA2 coding sequences to identify pathogenic mutations associated with inherited breast/ovarian cancer syndrome has provided a method to identify high-risk individuals, allowing them to seek preventative treatments and strategies. However, the current test is expensive, and cannot differentiate between pathogenic variants and those that may be benign. Focusing only on one of the two BRCA partners, we have developed a biological assay for haploinsufficiency of BRCA1. Using a series of EBV-transformed cell lines, we explored gene expression patterns in cells that were BRCA1 wildtype compared to those that carried (heterozygous) BRCA1 pathogenic mutations. We identified a subset of 43 genes whose combined expression pattern is a sensitive predictor of BRCA1 status. The gene set was disproportionately made up of genes involved in cellular differentiation, lending credence to the hypothesis that single copy loss of BRCA1 function may impact differentiation, rendering cells more susceptible to undergoing malignant processes. PMID:24950059

  19. LETM1-dependent mitochondrial Ca2+ flux modulates cellular bioenergetics and proliferation.

    PubMed

    Doonan, Patrick J; Chandramoorthy, Harish C; Hoffman, Nicholas E; Zhang, Xueqian; Cárdenas, César; Shanmughapriya, Santhanam; Rajan, Sudarsan; Vallem, Sandhya; Chen, Xiongwen; Foskett, J Kevin; Cheung, Joseph Y; Houser, Steven R; Madesh, Muniswamy

    2014-11-01

    Dysregulation of mitochondrial Ca(2+)-dependent bioenergetics has been implicated in various pathophysiological settings, including neurodegeneration and myocardial infarction. Although mitochondrial Ca(2+) transport has been characterized, and several molecules, including LETM1, have been identified, the functional role of LETM1-mediated Ca(2+) transport remains unresolved. This study examines LETM1-mediated mitochondrial Ca(2+) transport and bioenergetics in multiple cell types, including fibroblasts derived from patients with Wolf-Hirschhorn syndrome (WHS). The results show that both mitochondrial Ca(2+) influx and efflux rates are impaired in LETM1 knockdown, and similar phenotypes were observed in ΔEF hand, (D676A D688K)LETM1 mutant-overexpressed cells, and in cells derived from patients with WHS. Although LETM1 levels were lower in WHS-derived fibroblasts, the mitochondrial Ca(2+) uniporter components MCU, MCUR1, and MICU1 remain unaltered. In addition, the MCU mitoplast patch-clamp current (IMCU) was largely unaffected in LETM1-knockdown cells. Silencing of LETM1 also impaired basal mitochondrial oxygen consumption, possibly via complex IV inactivation and ATP production. Remarkably, LETM1 knockdown also resulted in increased reactive oxygen species production. Further, LETM1 silencing promoted AMPK activation, autophagy, and cell cycle arrest. Reconstitution of LETM1 or antioxidant overexpression rescued mitochondrial Ca(2+) transport and bioenergetics. These findings reveal the role of LETM1-dependent mitochondrial Ca(2+) flux in shaping cellular bioenergetics. PMID:25077561

  20. Time course of increased cellular proliferation in collateral arteries after administration of vascular endothelial growth factor in a rabbit model of lower limb vascular insufficiency.

    PubMed Central

    Takeshita, S.; Rossow, S. T.; Kearney, M.; Zheng, L. P.; Bauters, C.; Bunting, S.; Ferrara, N.; Symes, J. F.; Isner, J. M.

    1995-01-01

    Proliferation of vascular cells has been previously shown to contribute to spontaneous development of coronary collaterals. Recent studies from several laboratories have established that collateral artery growth in both the heart and limb can be enhanced by administration of angiogenic growth factors, or therapeutic angiogenesis. In this study, we sought (1) to define the extent and time course of endothelial cell (EC) and smooth muscle cell (SMC) proliferation accompanying spontaneous collateral development during limb ischemia and (2) to determine the extent to which proliferative activity of ECs and SMCs is augmented during therapeutic angiogenesis with vascular endothelial growth factor (VEGF), a heparin-binding EC-specific mitogen. Ten days after induction of limb ischemia by surgically excising the femoral artery of rabbits, either VEGF (500 to 1000 micrograms) or saline was administered as a bolus into the iliac artery of the ischemic limb. Cellular proliferation was evaluated by bromodeoxyuridine labeling for 24 hours at day 0 (immediately before VEGF administration) and at days 3, 5, and 7 after VEGF, EC proliferation in the midzone collaterals of VEGF-treated animals increased 2.8-fold at day 5 (P < 0.05 versus control), and returned to baseline levels by day 7. SMC proliferation in midzone collaterals also increased 2.7-fold in response to VEGF (P < 0.05). No significant increase in EC or SMC proliferation was observed in either the stem or re-entry collaterals of VEGF-treated animals compared with untreated ischemic control animals. Reduction of hemodynamic deficit in the ischemic limb measured by lower limb blood pressure was documented at day 7 after VEGF (P < 0.01 versus untreated, ischemic control). These data thus (1) establish the contribution of cellular proliferation to collateral vessel development in limb ischemia and (2) support the concept that augmented cellular proliferation contributes to the enhanced formation of collateral vessels after

  1. Methods to assess the nucleocytoplasmic shuttling of the HPV E1 helicase and its effects on cellular proliferation and induction of a DNA damage response.

    PubMed

    Lehoux, Michaël; Fradet-Turcotte, Amélie; Archambault, Jacques

    2015-01-01

    Replication of the human papillomavirus (HPV) double-stranded DNA genome in the nucleus of infected cells relies on the viral proteins E1 and E2 in conjunction with the host DNA replication machinery. This process is tightly linked to the replication of cellular DNA, in part through the cyclin-dependent phosphorylation of E1, which inhibits its export out of the nucleus to promote its accumulation in this compartment during S-phase. It has been recently shown that accumulation of E1 in the nucleus, while a prerequisite for viral DNA replication, leads to the inhibition of cellular proliferation and the activation of a DNA damage response (DDR). Here we describe methods to monitor the subcellular localization of E1 and to assess the deleterious effects of its nuclear accumulation on cellular proliferation, cell cycle progression and the induction of a DDR, using a combination of colony formation assays, immunofluorescence microcopy, and flow cytometry approaches. PMID:25348298

  2. Combined carbonate carbon isotopic and cellular ultrastructural studies of individual benthic foraminifera: 2. Toward an understanding of apparent disequilibrium in hydrocarbon seeps

    NASA Astrophysics Data System (ADS)

    Bernhard, Joan M.; Martin, Jonathan B.; Rathburn, Anthony E.

    2010-10-01

    Numerous previous studies show disequilibrium between stable carbon isotope ratios of foraminiferal calcite and pore water dissolved inorganic carbon in hydrocarbon seeps, calling into question the utility of this widely used paleoceanographic tracer as a proxy. We use a recently developed method to compare stable carbon isotope ratios of foraminiferal carbonate with cell ultrastructural observations from individual benthic foraminifera from seep (under chemosynthetic bivalves) and nonseep habitats in Monterey Bay, California, to better understand control(s) of benthic foraminiferal carbon isotope ratios. Two attributes previously proposed to cause the isotopic offsets are diet and symbionts. Ultrastructural analysis shows that positive staining with Rose Bengal indicates presence of foraminiferal cytoplasm, bacterial biomass, or a combination of both and, thus, is not an unequivocal indicator of viability. We also show for the first time that some living seep foraminifera have endobionts. Results from our unique, yet limited, data set are consistent with suggestions that, in our sites, several foraminiferal species collected from seep clam beds may not survive there, diet and symbiont presence do not appear to be major contributors to disequilibrium, little calcification of seep-tolerant foraminiferal species occurs while seep conditions prevail, and microscale variability in habitats could influence δ13C of benthic foraminiferal carbonate. Results further suggest that our knowledge of benthic foraminiferal ecology and biomineralization, especially in extreme habitats such as seeps, must be bolstered before we fully understand the fidelity of paleoenvironmental records derived from benthic foraminiferal test δ13C data.

  3. Long noncoding RNA HOTAIR is relevant to cellular proliferation, invasiveness, and clinical relapse in small-cell lung cancer

    PubMed Central

    Ono, Hiroshi; Motoi, Noriko; Nagano, Hiroko; Miyauchi, Eisaku; Ushijima, Masaru; Matsuura, Masaaki; Okumura, Sakae; Nishio, Makoto; Hirose, Tetsuro; Inase, Naohiko; Ishikawa, Yuichi

    2014-01-01

    Small-cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis. To identify accurate predictive biomarkers and effective therapeutic modalities, we focus on a long noncoding RNA, Hox transcript antisense intergenic RNA (HOTAIR), and investigated its expression, cellular functions, and clinical relevance in SCLC. In this study, HOTAIR expression was assessed in 35 surgical SCLC samples and 10 SCLC cell lines. The efficacy of knockdown of HOTAIR by siRNA transfection was evaluated in SBC-3 cells in vitro, and the gene expression was analyzed using microarray. HOTAIR was expressed highly in pure, rather than combined, SCLC (P = 0.012), that the subgroup with high expression had significantly more pure SCLC (P = 0.04), more lymphatic invasion (P = 0.03) and more relapse (P = 0.04) than the low-expression subgroup. The knockdown of HOTAIR in SBC-3 cells led to decreased proliferation activity and decreased invasiveness in vitro. Gene expression analysis indicated that depletion of HOTAIR resulted in upregulation of cell adhesion-related genes such as ASTN1, PCDHA1, and mucin production-related genes such as MUC5AC, and downregulation of genes involved in neuronal growth and signal transduction including NTM and PTK2B. Our results suggest that HOTAIR has an oncogenic role in SCLC and could be a prognostic biomarker and therapeutic target. PMID:24591352

  4. CD147 and AGR2 expression promote cellular proliferation and metastasis of head and neck squamous cell carcinoma

    SciTech Connect

    Sweeny, Larissa; Liu, Zhiyong; Bush, Benjamin D.; Hartman, Yolanda; Zhou, Tong; Rosenthal, Eben L.

    2012-08-15

    The signaling pathways facilitating metastasis of head and neck squamous cell carcinoma (HNSCC) cells are not fully understood. CD147 is a transmembrane glycoprotein known to induce cell migration and invasion. AGR2 is a secreted peptide also known to promote cell metastasis. Here we describe their importance in the migration and invasion of HNSCC cells (FADU and OSC-19) in vitro and in vivo. In vitro, knockdown of CD147 or AGR2 decreased cellular proliferation, migration and invasion. In vivo, knockdown of CD147 or AGR2 expression decreased primary tumor growth as well as regional and distant metastasis. -- Highlights: Black-Right-Pointing-Pointer We investigated AGR2 in head and neck squamous cell carcinoma for the first time. Black-Right-Pointing-Pointer We explored the relationship between AGR2 and CD147 for the first time. Black-Right-Pointing-Pointer AGR2 and CD147 appear to co-localize in head and squamous cell carcinoma samples. Black-Right-Pointing-Pointer Knockdown of both AGR2 and CD147 reduced migration and invasion in vitro. Black-Right-Pointing-Pointer Knockdown of both AGR2 and CD147 decreased metastasis in vivo.

  5. Effects of nicotine on cellular proliferation, macromolecular synthesis and cell cycle phase distribution in human and murine cells

    SciTech Connect

    Konno, S.; Chiao, J.; Rossi, J.; Wang, C.H.; Wu, J.M.

    1986-05-01

    Addition of nicotine causes a dose- and time-dependent inhibition of cell growth in established human and murine cells. In the human promyelocytic HL-60 leukemic cells, 3 mM nicotine results in a 50% inhibition of cellular proliferation after 80 h. Nicotine was also found to affect the cell cycle distribution of HL-60 cells. Treatment with 4 mM nicotine for 20 h causes an increase in proportion of Gl-phase cells (from 49% to 57%) and a significant decrease in the proportion of S-phase cells (from 41% to 32%). These results suggest that nicotine causes cell arrest in the Gl-phase which may in part account for its effects on cell growth. To determine whether nicotine has a primary effect on the uptake/transport of macromolecular precursors into cells, HL-60 cells were treated with 2-6 mM nicotine for 30 h/sub 3/ at the end of which time cells were labeled with (/sup 3/H)thymidine, (/sup 3/H)uridine, (/sup 14/C)lysine and (/sup 35/S)methionine, the trichloroacetic acid (TCA) soluble and insoluble radioactivities from each of the labeling conditions were determined. These studies show that nicotine primarily affect the synthesis of proteins.

  6. After portal branch ligation in the rat, cellular proliferation in associated with selective induction of c-Ha-ras, p53, cyclin E, and Cdk2

    PubMed Central

    Starkel, P; Lambotte, L; Sempoux, C; De Saeger, C; Saliez, A; Maiter, D; Horsmans, Y

    2001-01-01

    BACKGROUND—In liver regeneration after portal branch ligation we previously showed that early cellular changes are observed in both the proliferating and atrophying liver lobes. They are therefore not indicative of future proliferative response. In this study we attempted to define precisely, in the same model, the time at which the cellular processes diverge between the lobes by measuring various parameters associated with cellular proliferation. We also investigated the possible role of inhibitors of cell proliferation in the absence of progression towards the S phase in the atrophying lobes.
AIMS—Expression of p53, c-Ha-ras, cyclin E, cyclin dependent kinase (Cdk2), transforming growth factor (TGF)-β, and interleukin (IL)-1α and IL-1β were assessed in relation to their potential role in proliferating and atrophying cellular phenomenons.
METHODS—Immunohistochemistry, northern blotting, western blotting, and reverse transcription-polymerase chain reaction were performed, mainly at time points corresponding to mid-G1/S phase progression (8-24 hours after surgery).
RESULTS—The common and thus most likely non-specific response was still evident 5-8 hours after surgery and included an increase in IL-1 mRNA as well as p53 and cyclin E proteins. From 12 hours onwards, p53, c-Ha-ras, cyclin E, and Cdk2 were selectively induced in proliferating lobes whereas IL-1β was predominantly activated in atrophying lobes. No changes in TGF-β or IL-1α expression were observed at the same time points in any of the liver lobes.
CONCLUSIONS—The initial response to portal branch ligation and thus probably to partial hepatectomy seems to be non-specific for at least eight hours. Thereafter, p53, c-Ha-ras, cyclin E, and Cdk2 seem to drive cellular proliferation while IL-1β is associated with cellular atrophy. In contrast, TGF-β and IL-1α do not seem to play a role in determining the commitment of cells towards atrophy or proliferation.


Keywords: portal

  7. Influence of drought stress on the cellular ultrastructure and antioxidant system in leaves of drought-tolerant and drought-sensitive apple rootstocks.

    PubMed

    Wang, Shuncai; Liang, Dong; Li, Chao; Hao, Yonglu; Ma, Fengwang; Shu, Huairui

    2012-02-01

    We compared two apple rootstocks -Malus prunifolia and Malus hupehensis - that differ in their tolerance to this abiotic stress. The former is considered drought-tolerant, the latter, sensitive. We monitored changes in their leaf ultrastructure and responses by their antioxidant defense systems. Irrigation was withheld for 12 d from two-year-old potted plants. Compared with the control, this treatment led to considerable ultrastructural alterations in organelles. Plants of M. prunifolia maintained their structural cell integrity longer than did M. hupehensis. M. hupehensis was more vulnerable to drought than was M. prunifolia, resulting in larger increases in the levels of H(2)O(2), O(2)(-), and MDA from the former. Except for catalase (CAT) and monodehydroascorbate reductase (MDHAR), the activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) analyzed here were enhanced to a greater extent in M. prunifolia than in M. hupehensis in response to drought. This was also true for levels of ascorbic acid (AsA) and glutathione (GSH). Under well-watered conditions, changes in lipid peroxidation and relevant antioxidant parameters were not significantly different between the two species throughout the experimental period. These results demonstrate that, in order to minimize oxidative damage, both the activities of antioxidant enzymes and antioxidant concentrations are increased in the leaves of M. prunifolia and M. hupehensis in response to water stress. Moreover, plants of M. prunifolia exhibit higher antioxidant capacity and a stronger protective mechanism, such that their cell structural integrity is better maintained during exposure to drought. PMID:22153243

  8. Inhibition of cellular proliferation and modulation of insulin-like growth factor binding proteins by retinoids in a bovine mammary epithelial cell line.

    PubMed

    Woodward, T L; Turner, J D; Hung, H T; Zhao, X

    1996-06-01

    Retinoids are potent inhibitors of growth and tumor progression in many mammary carcinoma cell lines, though regulation of growth in nontumorigenic mammary epithelial cells by retinoids is less clear. Here, we have characterized the inhibition of MAC-T (a nontransformed bovine mammary epithelial cell line) cellular proliferation by retinoids and their role in regulating insulin-like growth factor binding proteins (IGFBPs). Retinoic acid (RA) (100 nM) was a potent inhibitor of MAC-T cell proliferation. Retinol was 10-100 times less effective. Neither retinoid could completely arrest growth at noncytotoxic concentrations. Retinoic acid inhibited cellular proliferation by 1 h (P < .05), but inhibition was fivefold greater by 24 h (P < .01). This second stage of growth inhibition (after 12 h) was dependent upon protein synthesis. However, RA-induced inhibition of cellular proliferation did not persist, with thymidine incorporation increasing toward control levels by 4 days in culture. Retinoic acid was less effective in inhibiting thymidine incorporation when cells were stimulated with insulin, des(1-3) IGF-I, or Long(R3) IGF-I when compared to cells stimulated with native IGF-I or serum. Inhibition of proliferation by RA was associated with increased levels of IGFBP-2 in conditioned media and in plasma membrane preparations. Treatment with insulin or des(1-3) IGF-I resulted in the appearance of IGFBP-3 in conditioned media and on the cell surface. However, RA significantly reduced IGFBP-3 levels in conditioned media and eliminated IGFBP-3 associated with the plasma membrane. Thus, RA is a potent but transient inhibitor of bovine mammary epithelial cell proliferation, and this growth inhibition is correlated with increased IGFBP-2 accumulation and inhibition of IGF-I stimulated IGFBP-3 protein secretion. PMID:8655603

  9. Electron Microscope and Autoradiographic Study of Ultrastructural Aspects of Competence and Deoxyribonucleic Acid Absorption in Bacillus subtilis: Ultrastructure of Competent and Noncompetent Cells and Cellular Changes During Development of Competence

    PubMed Central

    Vermeulen, C. A.; Venema, G.

    1974-01-01

    By means of electron microscope autoradiography of component cultures of Bacillus subtilis exposed to [3H]thymidine-labeled transforming deoxyribonucleic acid competent and noncompetent cells can be distinguished. Competence is not limited to a specific phase of the cell division cycle. With serial section electron microscopy of competent and noncompetent cells, two types of mesosomal structures are observed: mesosomes connected to the plasma membrane only (plasma membrane mesosomes) and mesosomes which are additionally connected to the nuclear bodies (nuclear mesosomes). The two types show different cellular distributions. Especially the number of nuclear mesosomes is higher in competent than in noncompetent cells. This, and the observation that the increase and decrease of competence is correlated with both the number of cells carrying nuclear mesosomes and the number of nuclear mesosomes per cell, suggests that mesosomes are involved in the acquisition of competence. PMID:4208130

  10. Changes in phenolic compounds and cellular ultrastructure of arctic and antarctic strains of Zygnema (Zygnematophyceae, Streptophyta) after exposure to experimentally enhanced UV to PAR ratio.

    PubMed

    Pichrtová, Martina; Remias, Daniel; Lewis, Louise A; Holzinger, Andreas

    2013-01-01

    Ultraviolet (UV) radiation has become an important stress factor in polar regions due to anthropogenically induced ozone depletion. Although extensive research has been conducted on adaptations of polar organisms to this stress factor, few studies have focused on semi-terrestrial algae so far, in spite of their apparent vulnerability. This study investigates the effect of UV on two semi-terrestrial arctic strains (B, G) and one Antarctic strain (E) of the green alga Zygnema, isolated from Arctic and Antarctic habitats. Isolates of Zygnema were exposed to experimentally enhanced UV A and B (predominant UV A) to photosynthetic active radiation (PAR) ratio. The pigment content, photosynthetic performance and ultrastructure were studied by means of high-performance liquid chromatography (HPLC), chlorophyll a fluorescence and transmission electron microscopy (TEM). In addition, phylogenetic relationships of the investigated strains were characterised using rbcL sequences, which determined that the Antarctic isolate (E) and one of the Arctic isolates (B) were closely related, while G is a distinct lineage. The production of protective phenolic compounds was confirmed in all of the tested strains by HPLC analysis for both controls and UV-exposed samples. Moreover, in strain E, the content of phenolics increased significantly (p = 0.001) after UV treatment. Simultaneously, the maximum quantum yield of photosystem II photochemistry significantly decreased in UV-exposed strains E and G (p < 0.001), showing a clear stress response. The phenolics were most probably stored at the cell periphery in vacuoles and cytoplasmic bodies that appear as electron-dense particles when observed by TEM after high-pressure freeze fixation. While two strains reacted moderately on UV exposure in their ultrastructure, in strain G, damage was found in chloroplasts and mitochondria. Plastidal pigments and xanthophyll cycle pigments were investigated by HPLC analysis; UV A- and UV B

  11. Girdin/GIV is upregulated by cyclic tension, propagates mechanical signal transduction, and is required for the cellular proliferation and migration of MG-63 cells

    SciTech Connect

    Hu, Jiang-Tian; Li, Yan; Yu, Bing; Gao, Guo-Jie; Zhou, Ting; Li, Song

    2015-08-21

    To explore how Girdin/GIV is regulated by cyclic tension and propagates downstream signals to affect cell proliferation and migration. Human osteoblast-like MG-63 cells were exposed to cyclic tension force at 4000 μstrain and 0.5 Hz for 6 h, produced by a four-point bending system. Cyclic tension force upregulated Girdin and Akt expression and phosphorylation in cultured MG-63 cells. Girdin and Akt each promoted the phosphorylation of the other under stimulated tension. In vitro MTT and transwell assays showed that Girdin and Akt are required for cell proliferation and migration during cellular quiescence. Moreover, STAT3 was determined to be essential for Girdin expression under stimulated tension force in the physiological condition, as well as for osteoblast proliferation and migration during quiescence. These findings suggest that the STAT3/Girdin/Akt pathway activates in osteoblasts in response to mechanical stimulation and may play a significant role in triggering osteoblast proliferation and migration during orthodontic treatment. - Highlights: • Tension force upregulates Girdin and Akt expression and phosphorylation. • Girdin and Akt promotes the phosphorylation of each other under tension stimulation. • Girdin and Akt are required for MG-63 cell proliferation and migration. • STAT3 is essential for Girdin expression after application of the tension forces.

  12. The human ubiquitin-conjugating enzyme Cdc34 controls cellular proliferation through regulation of p27{sup Kip1} protein levels

    SciTech Connect

    Butz, Nicole; Ruetz, Stephan; Natt, Francois; Hall, Jonathan; Weiler, Jan; Mestan, Juergen; Ducarre, Monique; Grossenbacher, Rita; Hauser, Patrick; Kempf, Dominique; Hofmann, Francesco . E-mail: francesco.hofmann@pharma.novartis.com

    2005-02-15

    Ubiquitin-mediated degradation of the cyclin-dependent kinase inhibitor p27{sup Kip1} was shown to be required for the activation of key cyclin-dependent kinases, thereby triggering the onset of DNA replication and cell cycle progression. Although the SCF{sup Skp2} ubiquitin ligase has been reported to mediate p27{sup Kip1} degradation, the nature of the human ubiquitin-conjugating enzyme involved in this process has not yet been determined at the cellular level. Here, we show that antisense oligonucleotides targeting the human ubiquitin-conjugating enzyme Cdc34 downregulate its expression, inhibit the degradation of p27{sup Kip1}, and prevent cellular proliferation. Elevation of p27{sup Kip1} protein level is found to be the sole requirement for the inhibition of cellular proliferation induced upon downregulation of Cdc34. Indeed, reducing the expression of p27{sup Kip1} with a specific antisense oligonucleotide is sufficient to reverse the anti-proliferative phenotype elicited by the Cdc34 antisense. Furthermore, downregulation of Cdc34 is found to specifically increase the abundance of the SCF{sup Skp2} ubiquitin ligase substrate p27{sup Kip1}, but has no concomitant effect on the level of IkB{alpha} and {beta}-catenin, which are known substrates of a closely related SCF ligase.

  13. A Model of the Ultrastructure of a Cell.

    ERIC Educational Resources Information Center

    Bushell, Jean

    2001-01-01

    Presents a project for modeling cellular ultrastructure for 14-17 year old students that helps to develop concepts of measurement and scaling in addition to supporting student understanding of cell biology. (Author/YDS)

  14. Control of cellular proliferation by modulation of oxidative phosphorylation in human and rodent fast-growing tumor cells

    SciTech Connect

    Rodriguez-Enriquez, Sara . E-mail: rodsar@mail.cardiologia.org.mx; Vital-Gonzalez, Paola A.; Flores-Rodriguez, Fanny L.; Marin-Hernandez, Alvaro; Ruiz-Azuara, Lena; Moreno-Sanchez, Rafael

    2006-09-01

    The relationship between cell proliferation and the rates of glycolysis and oxidative phosphorylation in HeLa (human) and AS-30D (rodent) tumor cells was evaluated. In glutamine plus glucose medium, both tumor lines grew optimally. Mitochondria were the predominant source of ATP in both cell types (66-75%), despite an active glycolysis. In glucose-free medium with glutamine, proliferation of both lines diminished by 30% but oxidative phosphorylation and the cytosolic ATP level increased by 50%. In glutamine-free medium with glucose, proliferation, oxidative phosphorylation and ATP concentration diminished drastically, although the cells were viable. Oligomycin, in medium with glutamine plus glucose, abolished growth of both tumor lines, indicating an essential role of mitochondrial ATP for tumor progression. The presumed mitochondrial inhibitors rhodamines 123 and 6G, and casiopeina II-gly, inhibited tumor cell proliferation and oxidative phosphorylation, but also glycolysis. In contrast, gossypol, iodoacetate and arsenite strongly blocked glycolysis; however, they did not affect tumor proliferation or mitochondrial metabolism. Growth of both tumor lines was highly sensitive to rhodamines and casiopeina II-gly, with IC{sub 5} values for HeLa cells lower than 0.5 {mu}M, whereas viability and proliferation of human lymphocytes were not affected by these drugs (IC{sub 5} > 30 {mu}M). Moreover, rhodamine 6G and casiopeina II-gly, at micromolar doses, prolonged the survival of animals bearing i.p. implanted AS-30D hepatoma. It is concluded that fast-growing tumor cells have a predominantly oxidative type of metabolism, which might be a potential therapeutic target.

  15. Mapping cellular processes in the mesenchyme during palatal development in the absence of Tbx1 reveals complex proliferation changes and perturbed cell packing and polarity.

    PubMed

    Brock, Lara J; Economou, Andrew D; Cobourne, Martyn T; Green, Jeremy B A

    2016-03-01

    The 22q11 deletion syndromes represent a spectrum of overlapping conditions including cardiac defects and craniofacial malformations. Amongst the craniofacial anomalies that are seen, cleft of the secondary palate is a common feature. Haploinsufficiency of TBX1 is believed to be a major contributor toward many of the developmental structural anomalies that occur in these syndromes, and targeted deletion of Tbx1 in the mouse reproduces many of these malformations, including cleft palate. However, the cellular basis of this defect is only poorly understood. Here, palatal development in the absence of Tbx1 has been analysed, focusing on cellular properties within the whole mesenchymal volume of the palatal shelves. Novel image analyses and data presentation tools were applied to quantify cell proliferation rates, including regions of elevated as well as reduced proliferation, and cell packing in the mesenchyme. Also, cell orientations (nucleus-Golgi axis) were mapped as a potential marker of directional cell movement. Proliferation differed only subtly between wild-type and mutant until embryonic day (E)15.5 when proliferation in the mutant was significantly lower. Tbx1(-/-) palatal shelves had slightly different cell packing than wild-type, somewhat lower before elevation and higher at E15.5 when the wild-type palate has elevated and fused. Cell orientation is biased towards the shelf distal edge in the mid-palate of wild-type embryos but is essentially random in the Tbx1(-/-) mutant shelves, suggesting that polarised processes such as directed cell rearrangement might be causal for the cleft phenotype. The implications of these findings in the context of further understanding Tbx1 function during palatogenesis and of these methods for the more general analysis of genotype-phenotype functional relationships are discussed. PMID:26689739

  16. Molecular and cellular effects of cis-9, trans-11-conjugated linoleic acid in enterocytes: effects on proliferation, differentiation, and gene expression.

    PubMed

    Lampen, A; Leifheit, M; Voss, J; Nau, H

    2005-06-15

    It has been hypothesized that dietary conjugated linoleic acids (CLA) may inhibit colon tumorigenesis. The aim of our study was to investigate the cellular and molecular effects of cis-9 (9Z), trans-11 (11E)-CLA on the proliferation, differentiation, interaction with peroxisome proliferator-activated receptors (PPARs), and expression of genes relevant in the APC-beta-catenin-TCF4 signalling pathway in human HT-29 and Caco-2 colon cells. We found that 9Z,11E-CLA inhibited the proliferation of HT-29 and Caco-2 cells. Trans-vaccenic acid (VA) showed no antiproliferative effects at all. We determined that 9Z,11E-CLA induced cell differentiation as measured by intestinal alkaline phosphatase (IAP) enzyme activity in Caco-2 cells, mRNA expression of IAP, and activation of a 5' flanking region of IAP. The 9Z,11E-CLA activated human PPARdelta as measured in a reporter gene assay. Treatment of HT29 cells in the poliferation phase with 9Z,11E-CLA repressed mRNA-expression of proliferation genes such as c-myc, cyclin D1 and c-jun in a concentration dependent manner. The promoter activities of c-myc and AP1 were also inhibited after incubation with 9Z,11E-CLA. beta-Catenin mRNA and protein expression was also repressed by the treatment with 9Z,11E-CLA. In addition, the mRNA expression of PPARdelta was repressed by treatment of the HT-29 cells with 9Z,11E-CLA. We conclude that 9Z,11E-CLA has an antiproliferative effect at the cellular and molecular levels in human colon cells. The results indicate that the preventive effects of CLA in the development of colon cancer may be due to their downregulation of some target genes of the APC-beta-catenin-TCF-4- and PPARdelta signalling pathway. PMID:15935729

  17. Relation of Internal Elastic Lamellar Layer Disruption to Neointimal Cellular Proliferation and Type III Collagen Deposition in Human Peripheral Artery Restenosis.

    PubMed

    Krishnan, Prakash; Purushothaman, K-Raman; Purushothaman, Meerarani; Baber, Usman; Tarricone, Arthur; Vasquez, Miguel; Wiley, Jose; Kini, Annapoorna; Sharma, Samin K; O'Connor, William N; Moreno, Pedro R

    2016-04-01

    Smooth muscle cell proliferation and extracellular matrix formation are responsible for disease progression in de novo and restenotic atherosclerosis. Internal elastic lamella (IEL) layer maintains the structural integrity of intima, and disruption of IEL may be associated with alterations in neointima, type III collagen deposition, and lesion progression in restenosis. Nineteen restenotic plaques (12 patients) procured during peripheral interventions were compared with 13 control plaques (12 patients) without restenosis. Hematoxylin & Eosin and elastic trichrome stains were used to measure length and percentage of IEL disruption, cellularity, and inflammation score. Type I and III collagens, smooth muscle cell (smc), fibroblast density, and nuclear proliferation (Ki67) percentage were evaluated by immunohistochemistry. IEL disruption percentage (28 ± 3.6 vs 6.1 ± 2.4; p = 0.0006), type III collagen content (0.33 ± 0.06 vs 0.17 ± 0.07; p = 0.0001), smc density (2014 ± 120 vs 923 ± 150; p = 0.0001), fibroblast density (2,282 ± 297 vs 906 ± 138; p = 0.0001), and Ki67 percentage (21.6 ± 2 vs 8.2 ± 0.65; p = 0.0001) were significantly increased in restenotic plaques compared to de novo plaques. Logistic regression analysis identified significant correlation between IEL disruption and neointimal smc density (r = 0.45; p = 0.01) and with type III collagen deposition (r = 0.61; p = 0.02) in restenosis. Increased IEL disruption may trigger cellular proliferation, altering collagen production, and enhancing restenotic neointima. In conclusion, understanding the pathologic and molecular basis of restenosis and meticulous-guided interventions oriented to minimize IEL damage may aid to reduce neointimal proliferation and the occurrence of restenosis. PMID:26857165

  18. Platelet rich concentrate promotes early cellular proliferation and multiple lineage differentiation of human mesenchymal stromal cells in vitro.

    PubMed

    Shani, Samuel; Ahmad, Raja Elina; Naveen, Sangeetha Vasudevaraj; Murali, Malliga Raman; Puvanan, Karunanithi; Abbas, Azlina Amir; Kamarul, Tunku

    2014-01-01

    Platelet rich concentrate (PRC) is a natural adjuvant that aids in human mesenchymal stromal cell (hMSC) proliferation in vitro; however, its role requires further exploration. This study was conducted to determine the optimal concentration of PRC required for achieving the maximal proliferation, and the need for activating the platelets to achieve this effect, and if PRC could independently induce early differentiation of hMSC. The gene expression of markers for osteocytes (ALP, RUNX2), chondrocytes (SOX9, COL2A1), and adipocytes (PPAR-γ) was determined at each time point in hMSC treated with 15% activated and nonactivated PRC since maximal proliferative effect was achieved at this concentration. The isolated PRC had approximately fourfold higher platelet count than whole blood. There was no significant difference in hMSC proliferation between the activated and nonactivated PRC. Only RUNX2 and SOX9 genes were upregulated throughout the 8 days. However, protein expression study showed formation of oil globules from day 4, significant increase in ALP at days 6 and 8 (P ≤ 0.05), and increased glycosaminoglycan levels at all time points (P < 0.05), suggesting the early differentiation of hMSC into osteogenic and adipogenic lineages. This study demonstrates that the use of PRC increased hMSC proliferation and induced early differentiation of hMSC into multiple mesenchymal lineages, without preactivation or addition of differentiation medium. PMID:25436230

  19. Effect of prior dietary exposure to cows' milk protein on antigen-specific and nonspecific cellular proliferation in mice.

    PubMed

    Brix, Susanne; Magyar, Orit H; Barkholt, Vibeke; Frøkiaer, Hanne

    2005-05-01

    The impact of dietary components on the immune system is gaining increased attention in the effort to develop safe food products, some even with health-promoting potential, as well as to improve the basic understanding of the immunomodulatory potential of common food components. In such studies, which are mainly based on experiments in vitro, it is important to be able to differentiate nonspecific activation of immune cells induced by dietary components from ex vivo restimulation of antigen-specific cells that might be present in cell cultures owing to prior dietary exposure to the antigens in cell donors. Focusing on the immunostimulatory potential of cows' milk proteins and peptides, we studied the impact of prior dietary exposure to cows' milk on proliferation of murine immune cells upon ex vivo stimulation with bovine milk proteins. Nonspecific proliferation induced by beta-casein peptides was further assessed on cells from mice bred on a cows'-milk-free diet. Regarding the dietary effect, we found that prior oral intake of cows' milk proteins affected cell proliferation induced by culturing with cows' milk proteins in vitro, as spleen cells from mice fed a milk-containing diet showed a significantly greater proliferative response than did cells from mice bred on a cows'-milk-free diet. Studies of immune enhancing potentials of beta-casein peptides showed that some peptides stimulate proliferation of immune cells nonspecifically. In conclusion, these findings stress the importance of employing immune cells from mice unexposed to cows' milk for studies of the immunomodulating capacity of cows' milk proteins and peptides, in order to rule out the interference caused by antigen-specific immune responses. By using such cells, we here show that some beta-casein peptides possess the potential to induce proliferation in immune cells in a nonspecific manner. PMID:15909688

  20. Overexpression of HOXB7 homeobox gene in oral cancer induces cellular proliferation and is associated with poor prognosis.

    PubMed

    De Souza Setubal Destro, Maria Fernanda; Bitu, Carolina Cavalcanti; Zecchin, Karina G; Graner, Edgard; Lopes, Marcio A; Kowalski, Luis Paulo; Coletta, Ricardo D

    2010-01-01

    A growing body of evidence has confirmed the involvement of dysregulated expression of HOX genes in cancer. HOX genes are a family of 39 transcription factors, divided in 4 clusters (HOXA to HOXD), that during normal development regulate cell proliferation and specific cell fate. In the present study it was investigated whether genes of the HOXB cluster play a role in oral cancer. We showed that most of the genes in the HOXB network are inactive in oral tissues, with exception of HOXB2, HOXB7 and HOXB13. Expression of HOXB7 was significantly higher in oral squamous cell carcinomas (OSCC) compared to normal oral mucosas. We further demonstrated that HOXB7 overexpression in HaCAT human epithelial cell line promoted proliferation, whereas downregulation of HOXB7 endogenous levels in human oral carcinoma cells (SCC9 cells) decreased proliferation. In OSCCs, expression of HOXB7 and Ki67, a marker of proliferation, correlate strongly with each other (rs=0.79, p<0.006). High immunohistochemical expression of HOXB7 was correlated with T stage (p=0.06), N stage (p=0.07), disease stage (p=0.09) and Ki67 expression (p=0.01), and patients with tumors showing high number of HOXB7-positive cells had shorter overall survival (p=0.08) and shorter disease-free survival after treatment (p=0.10) compared with patients with tumors exhibiting low amount of HOXB7-positive cells. Our data suggest that HOXB7 may contribute to oral carcinogenesis by increasing tumor cell proliferation, and imply that HOXB7 may be an important determinant of OSCC patient prognosis. PMID:19956843

  1. Inhibition of cellular proliferation by the Wilms' tumor suppressor WT1 is associated with suppression of insulin-like growth factor I receptor gene expression.

    PubMed Central

    Werner, H; Shen-Orr, Z; Rauscher, F J; Morris, J F; Roberts, C T; LeRoith, D

    1995-01-01

    We have investigated the regulation of the insulin-like growth factor I receptor (IGF-I-R) gene promoter by the Wilms' tumor suppressor WT1 in intact cells. The levels of endogenous IGF-I-R mRNA and the activity of IGF-I-R gene promoter fragments in luciferase reporter constructs were found to be significantly higher in G401 cells (a Wilms' tumor-derived cell line lacking detectable WT1 mRNA) than in 293 cells (a human embryonic kidney cell line which expresses significant levels of WT1 mRNA). To study whether WT1 could suppress the expression of the endogenous IGF-I-R gene, WT1-negative G401 cells were stably transfected with a WT1 expression vector. Expression of WT1 mRNA in G401 cells resulted in a significant decrease in the rate of cellular proliferation, which was associated with a reduction in the levels of IGF-I-R mRNA, promoter activity, and ligand binding and with a reduction in IGF-I-stimulated cellular proliferation, thymidine incorporation, and anchorage-independent growth. These data suggest that a major aspect of the action of the WT1 tumor suppressor is the repression of IGF-I-R gene expression. PMID:7791758

  2. Store-Operated Ca2+ Entry Does Not Control Proliferation in Primary Cultures of Human Metastatic Renal Cellular Carcinoma

    PubMed Central

    Turin, Ilaria; Potenza, Duilio Michele; Bottino, Cinzia; Glasnov, Toma N.; Ferulli, Federica; Mosca, Alessandra; Guerra, Germano; Rosti, Vittorio; Luinetti, Ombretta; Porta, Camillo; Pedrazzoli, Paolo

    2014-01-01

    Store-operated Ca2+ entry (SOCE) is activated following depletion of the inositol-1,4,5-trisphosphate (InsP3)-sensitive Ca2+ pool to regulate proliferation in immortalized cell lines established from either primary or metastatic lesions. The molecular nature of SOCE may involve both Stim1, which senses Ca2+ levels within the endoplasmic reticulum (ER) Ca2+ reservoir, and a number of a Ca2+-permeable channels on the plasma membrane, including Orai1, Orai3, and members of the canonical transient receptor (TRPC1–7) family of ion channels. The present study was undertaken to assess whether SOCE is expressed and controls proliferation in primary cultures isolated from secondary lesions of heavily pretreated metastatic renal cell carcinoma (mRCC) patients. SOCE was induced following pharmacological depletion of the ER Ca2+ store, but not by InsP3-dependent Ca2+ release. Metastatic RCC cells express Stim1-2, Orai1–3, and TRPC1–7 transcripts and proteins. In these cells, SOCE was insensitive to BTP-2, 10 µM Gd3+ and Pyr6, while it was inhibited by 100 µM Gd3+, 2-APB, and carboxyamidotriazole (CAI). Neither Gd3+ nor 2-APB or CAI impaired mRCC cell proliferation. Consistently, no detectable Ca2+ signal was elicited by growth factor stimulation. Therefore, a functional SOCE is expressed but does not control proliferation of mRCC cells isolated from patients resistant to multikinase inhibitors. PMID:25126575

  3. Downregulation of cellular prion protein inhibited the proliferation and invasion and induced apoptosis of Marek's disease virus-transformed avian T cells.

    PubMed

    Wan, Xuerui; Yang, Runxia; Liu, Guilin; Zhu, Manling; Zhang, Tianliang; Liu, Lei; Wu, Run

    2016-06-30

    Cellular prion protein (PrP(C)) is ubiquitously expressed in the cytomembrane of a considerable number of eukaryotic cells. Although several studies have investigated the functions of PrP(C) in cell proliferation, cell apoptosis, and tumorigenesis of mammals, the correlated functions of chicken PrP(C) (chPrP(C)) remain unknown. In this study, stable chPrP(C)-downregulated Marek's disease (MD) virus-transformed avian T cells (MSB1-SiRNA-3) were established by introducing short interfering RNA (SiRNA) targeting chicken prion protein genes. We found that downregulation of chPrP(C) inhibits proliferation, invasion, and migration, and induces G1 cell cycle phase arrest and apoptosis of MSB1-SiRNA-3 cells compared with Marek's disease virus-transformed avian T cells (MSB1) and negative control cells. To the best of our knowledge, the present study provides the first evidence supporting the positive correlation between the expression level of chPrP(C) and the proliferation, migration, and invasion ability of MSB1 cells, but appears to protect MSB1 cells from apoptosis, which suggests it functions in the formation and development of MD tumors. This evidence may contribute to future research into the specific molecular mechanisms of chPrP(C) in the formation and development of MD tumors. PMID:26243599

  4. Downregulation of cellular prion protein inhibited the proliferation and invasion and induced apoptosis of Marek's disease virus-transformed avian T cells

    PubMed Central

    Wan, Xuerui; Yang, Runxia; Liu, Guilin; Zhu, Manling; Zhang, Tianliang; Liu, Lei

    2016-01-01

    Cellular prion protein (PrPC) is ubiquitously expressed in the cytomembrane of a considerable number of eukaryotic cells. Although several studies have investigated the functions of PrPC in cell proliferation, cell apoptosis, and tumorigenesis of mammals, the correlated functions of chicken PrPC (chPrPC) remain unknown. In this study, stable chPrPC-downregulated Marek's disease (MD) virus-transformed avian T cells (MSB1-SiRNA-3) were established by introducing short interfering RNA (SiRNA) targeting chicken prion protein genes. We found that downregulation of chPrPC inhibits proliferation, invasion, and migration, and induces G1 cell cycle phase arrest and apoptosis of MSB1-SiRNA-3 cells compared with Marek's disease virus-transformed avian T cells (MSB1) and negative control cells. To the best of our knowledge, the present study provides the first evidence supporting the positive correlation between the expression level of chPrPC and the proliferation, migration, and invasion ability of MSB1 cells, but appears to protect MSB1 cells from apoptosis, which suggests it functions in the formation and development of MD tumors. This evidence may contribute to future research into the specific molecular mechanisms of chPrPC in the formation and development of MD tumors. PMID:26243599

  5. Cellular proliferation in the skin of X-rayed newt limbs (with a note on x-ray-induced limb regression)

    SciTech Connect

    Wertz, R.L.

    1982-07-01

    Left hind limbs, including the pelvis, of adult newts (Notophthalmus viridescens) were locally irradiated with a dose of x-rays that inhibited regeneration (2,000 R). This x-ray dose and other doses (700-2,000 R) capable of inhibiting limb regeneration also cause limb regression prior to amputation. Before limb regression occurred, there was a latent period of 3 to 6 weeks. Limb regression was characterized by necrotic wasting and resorption of distal elements. The degree of loss was variable and dependent upon dosage. After this further degenerative changes were not noted. Proliferation of epidermal cells was examined 4 days after irradiation prior to limb regression or after x-ray-induced degeneration of the limbs had ended. Proliferative activity in x-rayed limbs was also compared at various stages of contralateral control limb regeneration. Limbs examined after x-ray-induced limb regression had ended showed levels of (/sup 3/H)-thymidine incorporation into DNA comparable to normal epidermis. In contrast, limbs examined 4 days after irradiation had lower levels of DNA synthesis (P much less than 0.01). Amputation of limbs in both groups caused an increase in DNA synthesis (P much less than 0.01). Histological examination showed that cellular proliferation was associated primarily with the epidermis. These results indicate that epidermal cell proliferation was not resistant to x-rays. However, levels of normal cell division were observed after amputation of after cessation of x-ray-induced limb regression.

  6. Silencing of HMGA2 suppresses cellular proliferation, migration, invasion, and epithelial-mesenchymal transition in bladder cancer.

    PubMed

    Shi, Zhan; Li, Xiang; Wu, Ding; Tang, Run; Chen, Renfu; Xue, Song; Sun, Xiaoqing

    2016-06-01

    The high-mobility group protein A2 (HMGA2) is an architectural transcription factor that plays a crucial role in the development and progression of various malignant cancers. However, the function of HMGA2 in bladder cancer remains largely unknown. Therefore, we aim to investigate the effect of HMGA2 on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of bladder cancer cells. The expression of HMGA2 in human bladder cancer cells was downregulated by small interfering RNA (siRNA). The protein levels of HMGA2 and other related proteins were detected by Western blotting. The cell proliferation and apoptosis were examined by Cell Counting Kit-8 and flow cytometry, respectively. Transwell migration and invasion assays were performed to assess the effect of HMGA2 on the migration and invasion ability of cells. In conclusion, we found that HMGA2 knockdown markedly inhibited cell proliferation; this reduced cell growth was due to the high apoptosis rate of cells, as Bcl-xl was diminished, whereas Bax was upregulated. Moreover, our results showed that silencing of HMGA2 in cancer cells greatly inhibited the cell migration and invasion, decreased the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), and affected the occurrence of EMT. We further found that decreased HMGA2 expression suppressed the transforming growth factor-β (TGF-β)/Smad and Wnt/β-catenin signaling pathway in bladder cancer cells. These results revealed that HMGA2 played an important role in the progression of bladder cancer and might be a novel target for therapy in human bladder cancer. PMID:26684800

  7. Distinct effects of β1 integrin on cell proliferation and cellular signaling in MDA-MB-231 breast cancer cells

    PubMed Central

    Hou, Sicong; Isaji, Tomoya; Hang, Qinglei; Im, Sanghun; Fukuda, Tomohiko; Gu, Jianguo

    2016-01-01

    An aberrant expression of integrin β1 has been implicated in breast cancer progression. Here, we compared the cell behaviors of wild-type (WT), β1 gene deleted (KO), and β1 gene restored (Res) MDA-MB-231 cells. Surprisingly, the expression of β1 exhibited opposite effects on cell proliferation. These effects were dependent on cell densities, and they showed an up-regulation of cell proliferation when cells were cultured under sparse conditions, and a down-regulation of cell growth under dense conditions. By comparison with WT cells, the phosphorylation levels of ERK in KO cells were consistently suppressed under sparse culture conditions, but consistently up-regulated under dense culture conditions. The phosphorylation levels of EGFR were increased in the KO cells. By contrast, the phosphorylation levels of AKT were decreased in the KO cells. The abilities for both colony and tumor formation were significantly suppressed in the KO cells, suggesting that β1 plays an important role in cell survival signaling for tumorigenesis. These aberrant phenotypes in the KO cells were rescued in the Res cells. Taken together, these results clearly showed the distinct roles of β1 in cancer cells: the inhibition of cell growth and the promotion of cell survival, which may shed light on cancer therapies. PMID:26728650

  8. Caffeic Acid Inhibits Chronic UVB-Induced Cellular Proliferation Through JAK-STAT3 Signaling in Mouse Skin.

    PubMed

    Agilan, Balupillai; Rajendra Prasad, N; Kanimozhi, Govindasamy; Karthikeyan, Ramasamy; Ganesan, Muthusamy; Mohana, Shanmugam; Velmurugan, Devadasan; Ananthakrishnan, Dhanapalan

    2016-05-01

    Signal transducers and activators of transcription 3 (STAT3) play a critical role in inflammation, proliferation and carcinogenesis. Inhibition of JAK-STAT3 signaling is proved to be a novel target for prevention of UVB-induced skin carcinogenesis. In this study, chronic UVB irradiation (180 mJ cm(-2) ; weekly thrice for 30 weeks) induces the expression of IL-10 and JAK1 that eventually activates the STAT3 which leads to the transcription of proliferative and antiapoptotic markers such as PCNA, Cyclin-D1, Bcl2 and Bcl-xl, respectively. Caffeic acid (CA) inhibits JAK-STAT3 signaling, thereby induces apoptotic cell death by upregulating Bax, Cytochrome-C, Caspase-9 and Caspase-3 expression in mouse skin. Furthermore, TSP-1 is an antiangiogeneic protein, which is involved in the inhibition of angiogenesis and proliferation. Chronic UVB exposure decreased the expression of TSP-1 and pretreatment with CA prevented the UVB-induced loss of TSP-1 in UVB-irradiated mouse skin. Thus, CA offers protection against UVB-induced photocarcinogenesis probably through modulating the JAK-STAT3 in the mouse skin. PMID:27029485

  9. MicroRNA-203 inhibits cellular proliferation and invasion by targeting Bmi1 in non-small cell lung cancer

    PubMed Central

    CHEN, TENGFEI; XU, CHUN; CHEN, JUN; DING, CHENG; XU, ZHENLEI; LI, CHANG; ZHAO, JUN

    2015-01-01

    MicroRNAs are proposed to serve vital functions in the regulation of tumor progression and invasion. However, the expression levels of miR-203 in non-small cell lung cancer (NSCLC) and its clinical significance remain unknown. In the present study, the association between B-cell-specific moloney murine leukemia virus insertion site 1 (Bmi1) and miR-203 was investigated. miR-203 was demonstrated to act as a tumor suppressor by regulating the expression of Bmi1. miR-203 expression levels were downregulated in NSCLC tissues while Bmi1 expression was upregulated in NSCLC tissues and cell lines. Furthermore, downregulated Bmi1 or enhanced miR-203 expression inhibited NSCLC cell proliferation and invasion in vitro. In addition, a dual-luciferase reporter assay was performed, which identified Bmi1 as a novel target of miR-203. In conclusion, the present study demonstrated that miR-203 functions as a tumor suppressor and is important in inhibiting the proliferation of NSCLC cells through targeting Bmi1. These findings indicate that miR-203 may be useful as a novel potential therapeutic target for NSCLC. PMID:26137120

  10. Long non-coding RNA CCAT2 functions as an oncogene in hepatocellular carcinoma, regulating cellular proliferation, migration and apoptosis

    PubMed Central

    ZHOU, NING; SI, ZHONGZHOU; LI, TING; CHEN, GUANGSHUN; ZHANG, ZHONGQIANG; QI, HAIZHI

    2016-01-01

    An increasing number of studies have demonstrated that the dysregulation of long non-coding RNAs (lncRNAs) may serve an important role in tumor progression. Previous studies have reported that the lncRNA, colon cancer associated transcript 2 (CCAT2), was highly expressed in various tumors. However, the function of CCAT2 in hepatocellular carcinoma (HCC) has not yet been elucidated. The aim of the present study was to identify novel oncogene lncRNAs and investigate their physiological function and mechanism in HCC. Using reverse transcription-quantitative polymerase chain reaction, it was observed that CCAT2 was upregulated in HCC tissues and human HCC cell lines. Furthermore, the impacts of CCAT2 on cell proliferation, migration and apoptosis were analyzed using cell migration, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and enzyme-linked immunosorbent assay analysis respectively. The overexpression of CCAT2 using a synthesized vector significantly promoted cell migration and proliferation, and inhibited apoptosis of HCC cells in vitro. The suppression of CCAT2 expression resulted in opposing effects. To the best of our knowledge, the present study is the first to demonstrate that CCAT2 functions as a oncogene in HCC. Further investigation is required to clarify the molecular mechanisms of this lncRNA in HCC development.

  11. Study on connexin gene and protein expression and cellular distribution in relation to real-time proliferation of porcine granulosa cells.

    PubMed

    Kempisty, B; Ziółkowska, A; Ciesiółka, S; Piotrowska, H; Antosik, P; Bukowska, D; Nowicki, M; Brüssow, K P; Zabel, M

    2014-01-01

    Granulosa cells (GCs) play an important role during follicle growth and development in preovulatory stage. Moreover, the proteins such as connexins are responsible for formation of protein channel between follicular-cumulus cells and oocyte. This study was aimed to investigate the role of connexin expression in porcine GCs in relation to their cellular distribution and real-time cell proliferation. In the present study, porcine GCs were isolated from the follicles of puberal gilts and then cultured in a real-time cellular analyzer (RTCA) system for 168 h. The expression levels of connexins (Cxs) Cx36, Cx37, Cx40 and Cx43 mRNA were measured by RQ-PCR analysis, and differences in the expression and distribution of Cx30, Cx31, Cx37, Cx43 and Cx45 proteins were analyzed by confocal microscopic visualization. We found higher level of Cx36, Cx37, and Cx43 mRNA expression in GCs at recovery (at 0 h of in vitro culture, IVC) compared to all analyzed time periods of IVC (24, 48, 72, 96, 120, 144 and 168 h; P<0.001). On the other hand, the expression level of Cx40 transcripts was higher after 24 h of IVC compared to 0 h and the other times of IVC (P<0.001). Similarly to mRNAs, the expression levels of Cx31, Cx37 and Cx45 proteins were higher before (0 h) compared to after 168 h of IVC. The expression of Cx30 and Cx43, however, did not vary between the groups. In all, the proteins were distributed throughout the cell membrane rather than in the cytoplasm both before and after IVC. After 24 h of IVC, we observed a significant increase in the proliferation of GCs (log phase). We found differences in the proliferation index between 72-96 and 96- 140 h within the same population of GCs. In conclusion, the decrease in the expression of Cx mRNAs and proteins following IVC could be associated with a breakdown in gap-junction connections (GJCs), and leads to the decreased of their activity, which may be a reason of non-functional existence of connexon in follicular granulosa cells

  12. Sensitivity to methylmercury toxicity is enhanced in oxoguanine glycosylase 1 knockout murine embryonic fibroblasts and is dependent on cellular proliferation capacity

    SciTech Connect

    Ondovcik, Stephanie L.; Tamblyn, Laura; McPherson, John Peter; Wells, Peter G.

    2013-07-01

    Methylmercury (MeHg) is a persistent environmental contaminant with potent neurotoxic action for which the underlying molecular mechanisms remain to be conclusively delineated. Our objectives herein were twofold: first, to corroborate our previous findings of an increased sensitivity of spontaneously-immortalized oxoguanine glycosylase 1-null (Ogg1{sup −/−}) murine embryonic fibroblasts (MEFs) to MeHg through generation of Simian virus 40 (SV40) large T antigen-immortalized wild-type and Ogg1{sup −/−} MEFs; and second, to determine whether MeHg toxicity is proliferation-dependent. As with the spontaneously-immortalized cells used previously, the SV40 large T antigen-immortalized cells exhibited similar tendencies to undergo MeHg-initiated cell cycle arrest, with increased sensitivity in the Ogg1{sup −/−} MEFs as measured by clonogenic survival and DNA damage. Compared to exponentially growing cells, those seeded at a higher density exhibited compromised proliferation, which proved protective against MeHg-mediated cell cycle arrest and induction of DNA double strand breaks (DSBs), measured by phosphorylation of the core histone H2A variant (H2AX) on serine 139 (γH2AX), and by its functional confirmation by micronucleus assessment. This enhanced sensitivity of Ogg1{sup −/−} MEFs to MeHg toxicity using discrete SV40 immortalization corroborates our previous studies, and suggests a novel role for OGG1 in minimizing MeHg-initiated DNA lesions that trigger replication-associated DSBs. Furthermore, proliferative capacity may determine MeHg toxicity in vivo and in utero. Accordingly, variations in cellular proliferative capacity and interindividual variability in repair activity may modulate the risk of toxicological consequences following MeHg exposure. - Highlights: • SV40 large T antigen-immortalized Ogg1{sup −/−} cells are more sensitive to MeHg. • Sensitivity to MeHg is dependent on cellular proliferation capacity. • OGG1 maintains genomic

  13. Acetyl-keto-beta-boswellic acid inhibits cellular proliferation through a p21-dependent pathway in colon cancer cells.

    PubMed

    Liu, Jian-Jun; Huang, Baohua; Hooi, Shing Chuan

    2006-08-01

    1. Although there is increasing evidence showing that boswellic acid might be a potential anticancer agent, the mechanisms involved in its action are unclear. 2. In the present study, we showed that acetyl-keto-beta-boswellic acid (AKBA) inhibited cellular growth in several colon cancer cell lines. Cell cycle analysis by flow cytometry showed that cells were arrested at the G1 phase after AKBA treatment. 3. Further analysis showed that cyclin D1 and E, CDK 2 and 4 and phosphorylated Rb were decreased in AKBA-treated cells while p21 expression was increased. 4. The growth inhibitory effect of AKBA was dependent on p21 but not p53. HCT-116 p53(-/-) cells were sensitized to the apoptotic effect of AKBA, suggesting that p21 may have protected cells against apoptosis by inducing a G1 arrest.5. In conclusion, we have demonstrated that AKBA inhibited cellular growth in colon cancer cells. These findings may have implications to the use of boswellic acids as potential anticancer agents in colon cancer. PMID:16783403

  14. Imaging of cellular proliferation in liver metastasis by [18F]fluorothymidine positron emission tomography: effect of therapy

    NASA Astrophysics Data System (ADS)

    Contractor, Kaiyumars; Challapalli, Amarnath; Tomasi, Giampaolo; Rosso, Lula; Wasan, Harpreet; Stebbing, Justin; Kenny, Laura; Mangar, Stephen; Riddle, Pippa; Palmieri, Carlo; Al-Nahhas, Adil; Sharma, Rohini; Turkheimer, Federico; Coombes, R. Charles; Aboagye, Eric

    2012-06-01

    Although [18F]fluorothymidine positron emission tomography (FLT-PET) permits estimation of tumor thymidine kinase-1 expression, and thus, cell proliferation, high physiological uptake of tracer in liver tissue can limit its utility. We evaluated FLT-PET combined with a temporal-intensity information-based voxel-clustering approach termed kinetic spatial filtering (FLT-PETKSF) for detecting drug response in liver metastases. FLT-PET and computed tomography data were collected from patients with confirmed breast or colorectal liver metastases before, and two weeks after the first cycle of chemotherapy. Changes in tumor FLT-PET and FLT-PETKSF variables were determined. Visual distinction between tumor and normal liver was seen in FLT-PETKSF images. Of the 33 metastases from 20 patients studied, 26 were visible after kinetic filtering. The net irreversible retention of the tracer (Ki; from unfiltered data) in the tumor, correlated strongly with tracer uptake when the imaging variable was an unfiltered average or maximal standardized uptake value, 60 min post-injection (SUV60,av: r = 0.9, SUV60,max: r = 0.7; p < 0.0001 for both) and occurrence of high intensity voxels derived from FLT-PETKSF (r = 0.7, p < 0.0001). Overall, a significant reduction in the imaging variables was seen in responders compared to non-responders; however, the two week time point selected for imaging was too early to allow prediction of long term clinical benefit from chemotherapy. FLT-PET and FLT-PETKSF detected changes in proliferation in liver metastases.

  15. Short-term administration of rhGH increases markers of cellular proliferation but not milk protein gene expression in normal lactating women

    PubMed Central

    Maningat, Patricia D.; Sen, Partha; Rijnkels, Monique; Hadsell, Darryl L.; Bray, Molly S.

    2011-01-01

    Growth hormone is one of few pharmacologic agents known to augment milk production in humans. We hypothesized that recombinant human GH (rhGH) increases the expression of cell proliferation and milk protein synthesis genes. Sequential milk and blood samples collected over four days were obtained from five normal lactating women. Following 24 h of baseline milk and blood sampling, rhGH (0.1 mg/kg/day) was administered subcutaneously once daily for 3 days. Gene expression changes were determined by microarray studies utilizing milk fat globule RNA isolated from each milk sample. Following rhGH administration, DNA synthesis and cell cycle genes were induced, while no significant changes were observed in the expression of milk synthesis genes. Expression of glycolysis and citric acid cycle genes were increased by day 4 compared with day 1, while lipid synthesis genes displayed a circadian-like pattern. Cell cycle gene upregulation occurred after a lag of ∼2 days, likely explaining the failure to increase milk production after only 3 days of rhGH treatment. We conclude that rhGH induces expression of cellular proliferation and metabolism genes but does not induce milk protein gene expression, as potential mechanisms for increasing milk production and could account for the known effect of rhGH to increase milk production following 7–10 days. PMID:21205870

  16. Short-term administration of rhGH increases markers of cellular proliferation but not milk protein gene expression in normal lactating women.

    PubMed

    Maningat, Patricia D; Sen, Partha; Rijnkels, Monique; Hadsell, Darryl L; Bray, Molly S; Haymond, Morey W

    2011-04-27

    Growth hormone is one of few pharmacologic agents known to augment milk production in humans. We hypothesized that recombinant human GH (rhGH) increases the expression of cell proliferation and milk protein synthesis genes. Sequential milk and blood samples collected over four days were obtained from five normal lactating women. Following 24 h of baseline milk and blood sampling, rhGH (0.1 mg/kg/day) was administered subcutaneously once daily for 3 days. Gene expression changes were determined by microarray studies utilizing milk fat globule RNA isolated from each milk sample. Following rhGH administration, DNA synthesis and cell cycle genes were induced, while no significant changes were observed in the expression of milk synthesis genes. Expression of glycolysis and citric acid cycle genes were increased by day 4 compared with day 1, while lipid synthesis genes displayed a circadian-like pattern. Cell cycle gene upregulation occurred after a lag of ∼2 days, likely explaining the failure to increase milk production after only 3 days of rhGH treatment. We conclude that rhGH induces expression of cellular proliferation and metabolism genes but does not induce milk protein gene expression, as potential mechanisms for increasing milk production and could account for the known effect of rhGH to increase milk production following 7-10 days. PMID:21205870

  17. Flame synthesis and in vitro biocompatibility assessment of superparamagnetic iron oxide nanoparticles: cellular uptake, toxicity and proliferation studies.

    PubMed

    Buyukhatipoglu, K; Miller, T A; Clyne, A Morss

    2009-12-01

    Superparamagnetic iron oxide nanoparticles are used in diverse applications, such as targeted drug delivery, magnetic resonance imaging and hyperthermic malignant cell therapy. In the current work, superparamagnetic iron oxide nanoparticles were produced by flame synthesis, which has improved nanoparticle property control and is capable of commercial production rates with minimal post-processing. The iron oxide nanoparticle material characteristics were analyzed by electron microscopy and Raman spectroscopy. Finally, flame synthesized iron oxide nanoparticle interaction with endothelial cells was compared to commercially available iron oxide nanoparticles. Flame synthesis produced a heterogeneous mixture of 6-12 nm diameter hematite and magnetite nanoparticles with superparamagnetic properties. Endothelial cell scanning electron microscopy, confirmed by energy dispersive spectroscopy, demonstrated that flame synthesized nanoparticles are ingested into cells in a similar manner to commercially available nanoparticles. The flame synthesized particles showed no statistically significant toxicity difference from commercially available nanoparticles, as measured by Live/Dead assay, Alamar blue, and lactase dehydrogenase release. Neither type of nanoparticle affected cell proliferation induced by fibroblast growth factor-2. These data suggest that combustion synthesized iron oxide nanoparticles are comparable to commercially available nanoparticles for biological applications, yet flame synthesis is a simpler process with higher purity products and lower manufacturing costs. Future work will include functionalizing nanoparticles for specific cell targeting and bioactive factor delivery. PMID:19908687

  18. Expression of mRNAs encoding mammalian chromosomal proteins HMG-I and HMG-Y during cellular proliferation

    SciTech Connect

    Johnson, K.R.; Disney, J.E.; Wyatt, C.R.; Reeves, R. )

    1990-03-01

    The high mobility group chromosomal proteins HMG-I and HMG-Y are closely related isoforms that are expressed at high levels in rapidly dividing, undifferentiated mammalian cells. The authors analyzed HMG-I/Y mRNA levels at various cell cycle stages in murine NIH/3T3 fibroblasts partially synchronized by seeding from quiescent, contact-inhibited cultures. Flow microfluorometric analysis of DNA content demonstrated a comparable degree of synchronization in such seeded NIH 3T3 cell populations as is obtained by serum deprivation or other means and has the added advantage of avoiding the use of possibly detrimental inhibitors or metabolic starvation to induce such synchrony. They show that HMG-I/Y mRNA levels gradually increase in NIH/3T3 cells during the first 16 hours after seeding (G{sub 0}/G{sub 1} to late S phase), but thereafter remain constant, in contrast to the cell cycle-regulated expression of the histone H3 gene. The HMG-I/Y mRNAs appear to be very stable; there was no decrease in their levels 6 hours after actinomycin D transcription termination. The proportion of HMG-I to HMG-Y mRNAs was greater in the human than in the murine cells examined, appeared to be greater in proliferating than in quiescent cells, and did not always correspond with the HMG-I to HMG-Y protein ratio.

  19. Accumulated SET protein up-regulates and interacts with hnRNPK, increasing its binding to nucleic acids, the Bcl-xS repression, and cellular proliferation

    SciTech Connect

    Almeida, Luciana O.; Garcia, Cristiana B.; Matos-Silva, Flavia A.; Curti, Carlos; Leopoldino, Andréia M.

    2014-02-28

    Highlights: • hnRNPK is a new target of SET. • SET regulates hnRNPK. • SET and hnRNPK accumulation promotes tumorigenesis. • SET accumulation is a potential model to study genes regulated by SET-hnRNPK. - Abstract: SET and hnRNPK are proteins involved in gene expression and regulation of cellular signaling. We previously demonstrated that SET accumulates in head and neck squamous cell carcinoma (HNSCC); hnRNPK is a prognostic marker in cancer. Here, we postulate that SET and hnRNPK proteins interact to promote tumorigenesis. We performed studies in HEK293 and HNSCC (HN6, HN12, and HN13) cell lines with SET/hnRNPK overexpression and knockdown, respectively. We found that SET and/or hnRNPK protein accumulation increased cellular proliferation. SET accumulation up-regulated hnRNPK mRNA and total/phosphorylated protein, promoted hnRNPK nuclear location, and reduced Bcl-x mRNA levels. SET protein directly interacted with hnRNPK, increasing both its binding to nucleic acids and Bcl-xS repression. We propose that hnRNPK should be a new target of SET and that SET–hnRNPK interaction, in turn, has potential implications in cell survival and malignant transformation.

  20. A chimera embryo assay reveals a decrease in embryonic cellular proliferation induced by sperm from X-irradiated male mice

    SciTech Connect

    Obasaju, M.F.; Wiley, L.M.; Oudiz, D.J.; Raabe, O.; Overstreet, J.W.

    1989-05-01

    Male mice were divided into three experimental groups and a control group. Mice in the experimental groups received one of three doses of acute X irradiation (1.73, 0.29, and 0.05 Gy) and together with the control unirradiated mice were then mated weekly to unirradiated female mice for a 9-week experimental period. Embryos were recovered from the weekly matings at the four-cell stage and examined by the chimera assay for proliferative disadvantage. Aggregation chimeras were constructed of embryos from female mice mated to irradiated males (experimental embryos) and embryos from females mated to unexposed males (control embryos) and contained either one experimental embryo and one control embryo (heterologous chimera) or two control embryos (control chimera). The control embryo in heterologous chimeras and either embryo in control chimeras were prelabeled with the vital dye fluorescein isothiocyanate (FITC), and the chimeras were cultured for 40 h and viewed under phase-contrast and epifluorescence microscopy to obtain total embryo cell number and the cellular contribution from the FITC-labeled embryo. Experimental and control embryos that were cultured singly were also examined for embryo cell number at the end of the 40-h culture period. In control chimeras, the mean ratio of the unlabeled cells:total chimera cell number (henceforth referred to as ''mean ratio'') was 0.50 with little or no weekly variation over the 9-week experimental period. During Weeks 4-7, the mean ratios of heterologous chimeras differed significantly from the mean ratio of control chimeras with the greatest differences occurring during Week 7 (0.41 for chimeras of 0.05 Gy dose group, 0.40 for chimeras of the 0.29 Gy dose group, and 0.17 for chimeras of the 1.73 Gy dose group).

  1. Effects of iron and copper overload on the human liver: an ultrastructural study.

    PubMed

    Fanni, D; Fanos, V; Gerosa, C; Piras, M; Dessi, A; Atzei, A; Van, Eyken P; Gibo, Y; Faa, G

    2014-01-01

    Iron and copper ions play important roles in many physiological functions of our body, even though the exact mechanisms regulating their absorption, distribution and excretion are not fully understood. Metal-related human pathology may be observed in two different clinical settings: deficiency or overload. The overload in liver cells of both trace elements leads to multiple cellular lesions. Here we report the main pathological changes observed at transmission electron microscopy in the liver of subjects affected by Beta-thalassemia and by Wilson's disease. The hepatic iron overload in beta-thalassemia patients is associated with haemosiderin storage both in Kupffer cells and in the cytoplasm of hepatocytes. Haemosiderin granules are grouped inside voluminous lysosomes, also called siderosomes. Other ultrastructural changes are fat droplets, proliferation of the smooth endoplasmic reticulum and fibrosis. Apoptosis of hepatocytes and infiltration of sinusoids by polymorphonucleates is also detected in beta-thalassemia. Ultrastructural changes in liver biopsies from Wilson's disease patients are characterized by severe mitochondrial changes, associated with an increased number of perossisomes, cytoplasmic lipid droplets and the presence of lipolysosomes, characteristic cytoplasmic bodies formed by lipid vacuoles surrounded by electron-dense lysosomes. In patients affected by Wilson's disease, nuclei are frequently involved, with disorganization of the nucleoplasm and with glycogen inclusions. On the contrary, no significant changes are detected in Kupffer cells. Our data show that iron and copper, even though are both transition metals, are responsible of different pathological changes at ultrastructural level. In particular, copper overload is associated with mitochondrial damage, whereas iron overload only rarely may cause severe mitochondrial changes. These differences underlay the need for further studies in which biochemical analyses should be associated with

  2. A Novel Interaction between FLICE-Associated Huge Protein (FLASH) and E2A Regulates Cell Proliferation and Cellular Senescence via Tumor Necrosis Factor (TNF)-Alpha-p21WAF1/CIP1 Axis

    PubMed Central

    Hirano, Takahiro; Murakami, Taichi; Ono, Hiroyuki; Sakurai, Akiko; Tominaga, Tatsuya; Takahashi, Toshikazu; Nagai, Kojiro; Doi, Toshio; Abe, Hideharu

    2015-01-01

    Dysregulation of the cell proliferation has been implicated in the pathophysiology of a number of diseases. Cellular senescence limits proliferation of cancer cells, preventing tumorigenesis and restricting tissue damage. However, the role of cellular senescence in proliferative nephritis has not been determined. The proliferative peak in experimental rat nephritis coincided with a peak in E2A expression in the glomeruli. Meanwhile, E12 (an E2A-encoded transcription factor) did not promote proliferation of Mesangial cells (MCs) by itself. We identified caspase-8-binding protein FLICE-associated huge protein (FLASH) as a novel E2A-binding partner by using a yeast two-hybrid screening. Knockdown of FLASH suppressed proliferation of MCs. This inhibitory effect was partially reversed by the knockdown of E2A. In addition, the knockdown of FLASH induced cyclin-dependent kinase inhibitor p21WAF1/CIP1 (p21) expression, but did not affect p53 expression. Furthermore, overexpression of E12 and E47 induced p21, but not p53 in MCs, in the absence of FLASH. We also demonstrated that E2A and p21 expression at the peak of proliferation was followed by significant induction of FLASH in mesangial areas in rat proliferative glomerulonephritis. Moreover, we revealed that FLASH negatively regulates cellular senescence via the interaction with E12. We also demonstrated that FLASH is involved in the TNF-α-induced p21 expressions. These results suggest that the functional interaction of E2A and FLASH play an important role in cell proliferation and cellular senescence via regulation of p21 expression in experimental glomerulonephritis. PMID:26208142

  3. Premature ovarian failure: morphological and ultrastructural aspects.

    PubMed

    Haidar, M A; Baracat, E C; Simões, M J; Focchi, G R; Evêncio Neto, J; de Lima, G R

    1994-01-01

    The authors documented by means of light and transmission electron microscopy that the ovaries of women with premature ovarian failure (POF) displayed dense connective tissue and rare corpora albicantia. Eight of the ten studied cases did not present ovarian follicles; in two cases, it was verified the presence of ovarian follicles, atypical primordial follicles and in one case, a corpus luteum was identified (after stimulation with exogenous gonadotrophin). Regarding the ultrastructural analysis, it was noted that the fibroblasts were united one to each other by cellular prolongations that formed a woof, constituting a cellular syncicius. PMID:7610321

  4. In vitro effect of histamine and histamine H1 and H2 receptor antagonists on cellular proliferation of human malignant melanoma cell lines.

    PubMed

    Reynolds, J L; Akhter, J; Morris, D L

    1996-04-01

    Histamine is an established growth factor for gastric and colorectal cancer. Contradictory data for response of melanoma to histamine have been reported. Our aims were to determine the effect of histamine and H1 and H2 receptor antagonists on cell growth and cyclic AMP production. Four human melanoma cell lines were cultured with a range of concentrations of histamine, and with the H2 receptor antagonists cimetidine, ranitidine or famotidine, or the H1 receptor antagonist diphenhydramine. Cellular proliferation was measured by the uptake of [3H]-thymidine. Cyclic AMP production was also measured to determine the receptor status of the cell lines. Histamine significantly stimulated growth in two of four cell lines, with maximal stimulation at 1 x 10(-8) M. This effect was inhibited by all four antagonists in a dose-dependent manner. Histamine [10(-7) to 10(-4) M] also induced a dose-dependent increase in cyclic AMP production in the two histamine-responsive cell lines, suggesting that these cell lines express H2 receptors. We conclude that there may be a role for histamine receptor antagonists in melanoma treatment and that further investigation is warranted. PMID:8791266

  5. Threshold effect with stochastic fluctuation in bacteria-colony-like proliferation dynamics as analyzed through a comparative study of reaction-diffusion equations and cellular automata

    NASA Astrophysics Data System (ADS)

    Odagiri, Kenta; Takatsuka, Kazuo

    2009-02-01

    We report a comparative study on pattern formation between the methods of cellular automata (CA) and reaction-diffusion equations (RD) applying to a morphology of bacterial colony formation. To do so, we began the study with setting an extremely simple model, which was designed to realize autocatalytic proliferation of bacteria (denoted as X ) fed with nutrition (N) and their inactive state (prespore state) P1 due to starvation: X+N→2X and X→P1 , respectively. It was found numerically that while the CA could successfully generate rich patterns ranging from the circular fat structure to the viscous-finger-like complicated one, the naive RD reproduced only the circular pattern but failed to give a finger structure. Augmenting the RD equations by adding two physical factors, (i) a threshold effect in the dynamics of X+N→2X (breaking the continuity limit of RD) and (ii) internal noise with onset threshold (breaking the inherent symmetry of RD), we have found that the viscous-finger-like realistic patterns are indeed recovered by thus modified RD. This highlights the important difference between CA and RD, and at the same time, clarifies the necessary factors for the complicated patterns to emerge in such a surprisingly simple model system.

  6. Real-time proliferation of porcine cumulus cells is related to the protein levels and cellular distribution of Cdk4 and Cx43.

    PubMed

    Kempisty, Bartosz; Ziółkowska, Agnieszka; Piotrowska, Hanna; Zawierucha, Piotr; Antosik, Paweł; Bukowska, Dorota; Ciesiółka, Sylwia; Jaśkowski, Jędrzej M; Brüssow, Klaus P; Nowicki, Michał; Zabel, Maciej

    2013-09-01

    The proper maturation of cumulus somatic cells depends on bidirectional communication between the oocyte and the surrounding cumulus cells (CCs). The aim of this study was (i) to investigate maturation markers, such as Cx43 and Cdk4 protein levels, and (ii) to analyze the distribution of these two proteins in CCs cultured for 44, 88, 132, and 164 hours in both separated and cumulus-enclosed oocyte cultures. CCs were isolated from porcine ovarian follicles after the treatment of the recovered COCs with collagenase. Then, the separated CCs were cultured in TCM-199 for 0 to 164 hours, using a real-time cellular analyzer; however, the immunostaining was performed only after 44, 88, and 132 hours. The protein levels and distribution were analyzed using confocal microscopy. After the CCs underwent in vitro cultivation (IVC) for 25 hours, a logarithmically increasing normalized proliferation index was found throughout the entire 164 hours cultivation time. The Cx43 and Cdk4 proteins were observed at higher levels after 44 hours of culture than before IVC. After 88 and 132 hours of IVC, no significant alterations in either mRNA or protein levels of Cx43 and Cdk4 were found. Cx43 and Cdk4 were localized in the cell nucleus before IVC, whereas after 44, 88, and 132 hours of IVC, both proteins translocated to the cytoplasm. In cumulus-enclosed oocyte cultures, Cdk4 was localized both in the nucleus and cytoplasm, whereas Cx43 was only in the cytoplasm. Additionally, only low levels of the cumulus expansion markers MIS and SNAT3 were observed. In summary, we could demonstrate that the in vitro cultivation of CCs was associated with cell proliferation and that Cx43 and Cdk4 gene expression was upregulated after IVC, resulting in significantly higher protein levels. Moreover, the two proteins translocated from the nucleus to the cytoplasm of the CCs during IVC. The protein distribution is presumably related to different protein functions during bidirectional communication via

  7. Cellular changes in the hamster testicular interstitium with ageing and after exposure to short photoperiod.

    PubMed

    Beltrán-Frutos, E; Seco-Rovira, V; Ferrer, C; Madrid, J F; Sáez, F J; Canteras, M; Pastor, L M

    2016-04-01

    The aim of this study was to evaluate the cellular changes that occur in the hamster testicular interstitium in two very different physiological situations involving testicular involution: ageing and exposure to a short photoperiod. The animals were divided into an 'age group' with three subgroups - young, adult and old animals - and a 'regressed group' with animals subjected to a short photoperiod. The testicular interstitium was characterised by light and electron microscopy. Interstitial cells were studied histochemically with regard to their proliferation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling (TUNEL+) and testosterone synthetic activity. We identified two types of Leydig cell: Type A cells showed a normal morphology, while Type B cells appeared necrotic. With ageing, pericyte proliferation decreased but there was no variation in the index of TUNEL-positive Leydig cells. In the regressed group, pericyte proliferation was greater and TUNEL-positive cells were not observed in the interstitium. The testicular interstitium suffered few ultrastructural changes during ageing and necrotic Leydig cells were observed. In contrast, an ultrastructural involution of Leydig cells with no necrosis was observed in the regressed group. In conclusion, the testicular interstitium of Mesocricetus auratus showed different cellular changes in the two groups (age and regressed), probably due to the irreversible nature of ageing and the reversible character of changes induced by short photoperiod. PMID:25437143

  8. Ultrastructural study of thyroid capillaries after IR laser radiation

    NASA Astrophysics Data System (ADS)

    Vidal, Lourdes; Perez de Vargas, I.; Carrillo, F.; Parrado, C.; Pelaez, A.

    1994-02-01

    Laser radiation causes microscopical changes in the follicular cells relative to dose intensity. So, we have observed focal degenerative phenomena, at maximal doses, and activation of cellular function similar to the ones observed after stimulation with TSH, at minimal doses. In order to evaluate the evolution of these changes we have planned an ultrastructural study of rats thyroid capillaries treated with IR laser radiation.

  9. Ultrastructure of Polyangium cellulosum.

    PubMed Central

    Lampky, J R

    1976-01-01

    Polyangium cellulosum was examined with the transmission electron microscope and the scanning electron microscope. Freeze-fracturing and critical-point-drying techniques were employed with the latter instrument. Critical-point drying seemed to eliminate the distortion of cells and fruiting bodies. These instruments and techniques allowed for a detailed comparison of cell and fruiting-body ultrastructure. Lipid storage materials and mesosomes were found to be constant cell particulates in both vegetative cells and in the shortened myxospores. Images PMID:820686

  10. The ultrastructure of conjunctival melanocytic tumors.

    PubMed Central

    Jakobiec, F A

    1984-01-01

    The ultrastructure of conjunctival melanocytic lesions in 49 patients was evaluated to find significant differences between benign and malignant cells. The patients studied included 9 with benign epithelial (racial) melanosis, 2 with pigmented squamous cell papillomas, 16 with conjunctival nevi, 18 with primary acquired melanosis, and 11 with invasive nodules of malignant melanoma. In benign epithelial melanosis, dendritic melanocytes were situated along the basement membrane region of the conjunctival epithelium, with one basilar dendritic melanocyte lodged among every five or six basilar keratinocytes. The dendritic melanocytes extended arborizing cellular processes between the basilar and among the suprabasilar keratinocytes, which manifested considerable uptake of melanin granules into their cytoplasm. The benign dendritic melanocytes possessed nuclei with clumped heterochromatin at the nuclear membrane, small, tightly wound nucleoli, and large, elongated, fully melaninized melanin granules. In two patients with benign hyperplasia of the dendritic melanocytes, occasional dendritic melanocytes were located in a suprabasilar position, but were always separated from each other by keratinocytes or their processes. In the two black patients with benign pigmented squamous papillomas, the benign dendritic melanocytes were located hapharzardly at all levels of the acanthotic epithelium and not just along the basement membrane region. Melanin uptake by the proliferating keratinocytes was minimal. In benign melanocytic nevi of the conjunctiva, nevus cells within the intraepithelial junctional nests displayed a more rounded cellular configuration; short villi and broader cellular processes suggestive of abortive dendrites were found. The nuclear chromatin pattern was clumped at the nuclear membrane, but the nucleoli were somewhat larger than those of benign dendritic melanocytes in epithelial melanosis. The melanosomes were smaller and rounder than those in dendritic

  11. Increased cellular immune responses and CD4+ T-cell proliferation correlate with reduced plasma viral load in SIV challenged recombinant simian varicella virus - simian immunodeficiency virus (rSVV-SIV) vaccinated rhesus macaques

    PubMed Central

    2012-01-01

    Background An effective AIDS vaccine remains one of the highest priorities in HIV-research. Our recent study showed that vaccination of rhesus macaques with recombinant simian varicella virus (rSVV) vector – simian immunodeficiency virus (SIV) envelope and gag genes, induced neutralizing antibodies and cellular immune responses to SIV and also significantly reduced plasma viral loads following intravenous pathogenic challenge with SIVMAC251/CX1. Findings The purpose of this study was to define cellular immunological correlates of protection in rSVV-SIV vaccinated and SIV challenged animals. Immunofluorescent staining and multifunctional assessment of SIV-specific T-cell responses were evaluated in both Experimental and Control vaccinated animal groups. Significant increases in the proliferating CD4+ T-cell population and polyfunctional T-cell responses were observed in all Experimental-vaccinated animals compared with the Control-vaccinated animals. Conclusions Increased CD4+ T-cell proliferation was significantly and inversely correlated with plasma viral load. Increased SIV-specific polyfunctional cytokine responses and increased proliferation of CD4+ T-cell may be crucial to control plasma viral loads in vaccinated and SIVMAC251/CX1 challenged macaques. PMID:22889373

  12. 3D Morphology, Ultrastructure and Development of Ceratomyxa puntazzi Stages: First Insights into the Mechanisms of Motility and Budding in the Myxozoa

    PubMed Central

    Alama-Bermejo, Gema; Bron, James Emmanuel; Raga, Juan Antonio; Holzer, Astrid Sibylle

    2012-01-01

    Free, amoeboid movement of organisms within media as well as substrate-dependent cellular crawling processes of cells and organisms require an actin cytoskeleton. This system is also involved in the cytokinetic processes of all eukaryotic cells. Myxozoan parasites are known for the disease they cause in economical important fishes. Usually, their pathology is related to rapid proliferation in the host. However, the sequences of their development are still poorly understood, especially with regard to pre-sporogonic proliferation mechanisms. The present work employs light microscopy (LM), electron microscopy (SEM, TEM) and confocal laser scanning microscopy (CLSM) in combination with specific stains (Nile Red, DAPI, Phalloidin), to study the three-dimensional morphology, motility, ultrastructure and cellular composition of Ceratomyxa puntazzi, a myxozoan inhabiting the bile of the sharpsnout seabream. Our results demonstrate the occurrence of two C. puntazzi developmental cycles in the bile, i.e. pre-sporogonic proliferation including frequent budding as well as sporogony, resulting in the formation of durable spore stages and we provide unique details on the ultrastructure and the developmental sequence of bile inhabiting myxozoans. The present study describes, for the first time, the cellular components and mechanisms involved in the motility of myxozoan proliferative stages, and reveals how the same elements are implicated in the processes of budding and cytokinesis in the Myxozoa. We demonstrate that F-actin rich cytoskeletal elements polarize at one end of the parasites and in the filopodia which are rapidly de novo created and re-absorbed, thus facilitating unidirectional parasite motility in the bile. We furthermore discover the myxozoan mechanism of budding as an active, polarization process of cytokinesis, which is independent from a contractile ring and thus differs from the mechanism, generally observed in eurkaryotic cells. We hereby demonstrate that CLSM

  13. Ultrastructural hepatocytic alterations induced by silver nanoparticle toxicity.

    PubMed

    Almansour, Mansour; Sajti, Laszlo; Melhim, Walid; Jarrar, Bashir M

    2016-01-01

    Silver nanoparticles (SNPs) are widely used in nanomedicine and consuming products with potential risk to human health. While considerable work was carried out on the molecular, biochemical, and physiological alterations induced by these particles, little is known of the ultrastructural pathological alterations that might be induced by nanosilver materials. The aim of the present work is to investigate the hepatocyte ultrastructural alterations that might be induced by SNP exposure. Male rats were subjected to a daily single dose (2 mg/kg) of SNPs (15-35 nm diameter) for 21 days. Liver biopsies from all rats under study were processed for transmission electron microscopy examination. The following hepatic ultrastructural alterations were demonstrated: mitochondria swelling and crystolysis, endoplasmic reticulum disruption, cytoplasmic vacuolization, lipid droplets accumulation, glycogen depletion, karyopyknosis, apoptosis, sinusoidal dilatation, Kupffer cells activation, and myelin figures formation. The current findings may indicate that SNPs can induce hepatocyte organelles alteration, leading to cellular damage that may affect the function of the liver. These findings might indicate that SNPs potentially trigger heptocyte ultrastructural alterations that may affect the function of the liver with potential risk on human health in relation to numerous applications of these particles. More work is needed to elucidate probable ultrastructural alterations in the vital organs that might result from nanosilver toxicity. PMID:26934218

  14. Nerve Regeneration Potential of Protocatechuic Acid in RSC96 Schwann Cells by Induction of Cellular Proliferation and Migration through IGF-IR-PI3K-Akt Signaling.

    PubMed

    Ju, Da-Tong; Liao, Hung-En; Shibu, Marthandam Asokan; Ho, Tsung-Jung; Padma, Viswanadha Vijaya; Tsai, Fuu-Jen; Chung, Li-Chin; Day, Cecilia Hsuan; Lin, Chien-Chung; Huang, Chih-Yang

    2015-12-31

    Peripheral nerve injuries, caused by accidental trauma, acute compression or surgery, often result in temporary or life-long neuronal dysfunctions and inflict great economic or social burdens on the patients. Nerve cell proliferation is an essential process to restore injured nerves of adults. Schwann cells play a crucial role in endogenous repair of peripheral nerves due to their ability to proliferate, migrate and provide trophic support to axons via expression of various neurotrophic factors, such as the nerve growth factor (NGF), especially after nerve injury. Protocatechuic acid (PCA) is a dihydroxybenzoic acid, a type of phenolic acid, isolated from the kernels of Alpinia oxyphylla Miq (AOF), a traditional Chinese herbal medicine the fruits of which are widely used as a tonic, aphrodisiac, anti-salivation and anti-diarrheatic. This study investigated the molecular mechanisms by which PCA induces Schwann cell proliferation by activating IGF-IR-PI3K-Akt pathway. Treatment with PCA induces phosphorylation of the insulin-like growth factor-I (IGF-I)-mediated phosphatidylinositol 3 kinase/serine - threonine kinase (PI3K/Akt) pathway, and activates expression of cell nuclear antigen (PCNA) in a dose-dependent manner. Cell cycle analysis after 18 h of treatment showed that proliferation of the RSC96 cells was enhanced by PCA treatment. The PCA induced proliferation was accompanied by modulation in the expressions of cell cycle proteins cyclin D1, cyclin E and cyclin A. Knockdown of PI3K using small interfering RNA (siRNA) and inhibition of IGF-IR receptor resulted in the reduction in cell survival proteins. The results collectively showed that PCA treatment promoted cell proliferation and cell survival via IGF-I signaling. PMID:26717920

  15. Short-term administration of rhGH increases markers of cellular proliferation, but not milk protein gene expression in normal lactating women.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth hormone is one of few pharmacologic agents known to augment milk production in humans. We hypothesized that recombinant human GH (rhGH) increases the expression of cell proliferation and milk protein synthesis genes. Sequential milk and blood samples collected over four days were obtained fro...

  16. Association between the expression of LHR, FSHR and CYP19 genes, cellular distribution of encoded proteins and proliferation of porcine granulosa cells in real-time.

    PubMed

    Kempisty, B; Ziółkowska, A; Ciesiółka, S; Piotrowska, H; Antosik, P; Bukowska, D; Nowicki, M; Brüssow, K P; Zabel, M

    2014-01-01

    The process of granulosa cell luteinization is part of the main process determining growth, differentiation and proliferation of these cells. Although the mechanisms underlying the regulation of luteinizing hormone receptor (LHR), follicle stimulating hormone receptor (FSHR) and cytochrome P450 aromatase expression in mammalian granulosa cells is well understood, still little is known about the expression of mRNA and encoded proteins in relation to cell proliferation and luteinization in vitro. Porcine granulosa cells were observed in vitro at a168-h period while undergoing real-time proliferation using an RTCA system. Furthermore, LHR, FSHR and CYP19 mRNA expression were detected using RQ-PCR after 168 h of in vitro culture (IVC) at 24-h intervals, and LHR, FSHR and P450arom were examined by confocal microscopic observation at 0 h, 24 h, 48 h, 96 h, and 168 h of IVC. We found increased expression of LHR and CYP19 mRNA at 24 h and 48 h of IVC compared to the other stages (P less than 0.01, P less than 0.001), whereas FSHR mRNA was higher only at 0 h (P less than 0.001). In contrast, LHR, FSHR and P450arom protein expression was significantly higher at the end of the 168-h IVC period compared to 0 h, 24 h, 48 h and 96 h (P less than 0.001). LHR, FSHR and P450arom were distributed in the cytoplasm of porcine GCs at each time point of IVC. When analyzing cell proliferation, differences in cell index were observed (at least P less than 0.05) between the first (0-24 h) and the last period (144-168 h) of IVC; however, soon after 24 h of IVC a logarithmic increase in proliferation was also seen. We assume that the expression of LHR, FSHR and CYP19 mRNAs depends on the period of in vitro cultivation and may be linked with the luteinization process of porcine GCs. Furthermore, the patterns of mRNA and protein expression suggest a post-transcriptional regulation of LHR, FSHR and P450arom. In summary, it can be presumed that mRNA and protein expression and in vitro

  17. Ultrastructural evidence for differentiation in a human glioblastoma cell line treated with inhibitors of eicosanoid metabolism

    SciTech Connect

    Wilson, D.E.; Anderson, K.M. ); Seed, T.M. )

    1990-01-01

    Human glioblastoma cells incubated in the presence of inhibitors of eicosanoid biosynthesis show decreased cellular proliferation without cytotoxicity. The authors studied the ultrastructural morphology of a human glioblastoma cell line cultured with nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, or 5,8,11,14-eicosatetraynoic acid, a cyclooxygenase and lipoxygenase inhibitor. When glioblastoma cells were treated for 3 days with antiproliferative concentrations of either agent, they shared many morphological characteristics, including evidence for increased astrocytic differentiation with only limited signs of toxicity. The inhibited glioma cells demonstrated an increase in the number and length of astrocytic processes containing greater numbers of glial filaments, and the NDGA-treated cells also demonstrated extensive lateral pseudopod formation along the processes. The glioblastoma cell shape also become more elongated, losing the usual nuclear lobularity and nuclear inclusions, especially in NDGA-treated cells. Many cytoplasmic organelles packed the cytosol of the inhibited glioma cells, including prominent Golgi apparatus, dilated smooth endoplasmic reticulum evolving into dilated vesicles, cytoplasmic vacuoles, and numerous concentric laminations. There was limited evidence for toxicity, however, as the mitochondria were more pleomorphic with some mitochondrial distension and disruption of the cristae along with an increase in cytoplasmic vacuolization. The authors conclude that the inhibitors of eicosanoid biosynthesis. NDGA and 5,8,11,14-eicosatetraynoic acid, not only suppress glioblastoma cell proliferation, but also include increased astrocytic differentiation.

  18. Cell Membrane CD44v6 Levels in Squamous Cell Carcinoma of the Lung: Association with High Cellular Proliferation and High Concentrations of EGFR and CD44v5

    PubMed Central

    Ruibal, Álvaro; Aguiar, Pablo; Del Río, María Carmen; Nuñez, Matilde Isabel; Pubul, Virginia; Herranz, Michel

    2015-01-01

    Membranous CD44v6 levels in tumors and surrounding samples obtained from 94 patients with squamous cell lung carcinomas were studied and compared to clinical stage, cellular proliferation, membranous CD44v5 levels, epidermal growth factor receptor EGFR and cytoplasmatic concentrations of CYFRA 21.1. CD44v6 positive values were observed in 33/38 non-tumor samples and in 76/94 tumor samples, but there were not statistically significant differences between both subgroups. In CD44v6 positive tumor samples, CD44v6 was not associated with clinical stage, histological grade, ploidy and lymph node involvement, but significant association was found with high cellular proliferation. Likewise, CD44v6 positive tumors had significantly higher levels of EGFR and CD44v5. In patients with squamous cell lung carcinomas and clinical stage I, positive CD44v6 cases were associated with the same parameters. Furthermore, positive CD44v5 squamous tumors were associated significantly with histological grade III and lower levels of CYFRA21.1. Our findings support the value of CD44v6 as a possible indicator of poor outcome in patients with squamous lung carcinomas. PMID:25809603

  19. Cell membrane CD44v6 levels in squamous cell carcinoma of the lung: association with high cellular proliferation and high concentrations of EGFR and CD44v5.

    PubMed

    Ruibal, Álvaro; Aguiar, Pablo; Del Río, María Carmen; Nuñez, Matilde Isabel; Pubul, Virginia; Herranz, Michel

    2015-01-01

    Membranous CD44v6 levels in tumors and surrounding samples obtained from 94 patients with squamous cell lung carcinomas were studied and compared to clinical stage, cellular proliferation, membranous CD44v5 levels, epidermal growth factor receptor EGFR and cytoplasmatic concentrations of CYFRA 21.1. CD44v6 positive values were observed in 33/38 non-tumor samples and in 76/94 tumor samples, but there were not statistically significant differences between both subgroups. In CD44v6 positive tumor samples, CD44v6 was not associated with clinical stage, histological grade, ploidy and lymph node involvement, but significant association was found with high cellular proliferation. Likewise, CD44v6 positive tumors had significantly higher levels of EGFR and CD44v5. In patients with squamous cell lung carcinomas and clinical stage I, positive CD44v6 cases were associated with the same parameters. Furthermore, positive CD44v5 squamous tumors were associated significantly with histological grade III and lower levels of CYFRA21.1. Our findings support the value of CD44v6 as a possible indicator of poor outcome in patients with squamous lung carcinomas. PMID:25809603

  20. Hepatitis C virus E2 protein promotes human hepatoma cell proliferation through the MAPK/ERK signaling pathway via cellular receptors

    SciTech Connect

    Zhao Lanjuan; Wang Lu; Ren Hao; Cao Jie; Li Li; Ke Jinshan; Qi Zhongtian . E-mail: qizt53@hotmail.com

    2005-04-15

    Dysregulation of mitogen-activated protein kinase (MAPK) signaling pathways by various viruses has been shown to be responsible for viral pathogenicity. The molecular mechanism by which hepatitis C virus (HCV) infection caused human liver diseases has been investigated on the basis of abnormal intracellular signal events. Current data are very limited involved in transmembrane signal transduction triggered by HCV E2 protein. Here we explored regulation of the MAPK/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway by E2 expressed in Chinese hamster oval cells. In human hepatoma Huh-7 cells, E2 specifically activated the MAPK/ERK pathway including downstream transcription factor ATF-2 and greatly promoted cell proliferation. CD81 and low density lipoprotein receptor (LDLR) on the cell surface mediated binding of E2 to Huh-7 cells. The MAPK/ERK activation and cell proliferation driven by E2 were suppressed by blockage of CD81 as well as LDLR. Furthermore, pretreatment with an upstream kinase MEK1/2 inhibitor U0126 also impaired the MAPK/ERK activation and cell proliferation induced by E2. Our results suggest that the MAPK/ERK signaling pathway triggered by HCV E2 via its receptors maintains survival and growth of target cells.

  1. Depletion of tumour glutathione in vivo by buthionine sulphoximine: modulation by the rate of cellular proliferation and inhibition of cancer growth.

    PubMed Central

    Terradez, P; Asensi, M; Lasso de la Vega, M C; Puertes, I R; Viña, J; Estrela, J M

    1993-01-01

    We have investigated in Ehrlich-ascites-tumour-bearing mice the effect of buthionine sulphoximine (BSO), a selective inhibitor of GSH synthesis, on the rate of GSH depletion of tumour versus normal tissues and its relation to tumour cell proliferation. In normal tissues, GSH and GSSG remain unchanged or close to normal values during tumour growth, even at the last stage of growth when the animal is close to death. After administration of a single dose of BSO (4 mmol/kg), the rates of GSH depletion and recovery in the tumour and in several normal tissues are very different. BSO depletes GSH in cancer cells to a level of 0.3-0.4 mumol/g. The fall in GSH levels is faster when tumour cells do not proliferate actively. Four treatments of 4 mmol of BSO/kg at 48 h intervals induce a significant decrease (about 44%) in tumour growth. Our data show that the rate of BSO-induced GSH depletion in cancer cells depends on the stage of tumour growth, and that BSO administration also inhibits cancer-cell proliferation. A mechanism involving changes in protein kinase C activity and intracellular pH is proposed to explain the inhibition of cancer growth elicited by BSO. PMID:8503882

  2. Tumor suppressor miR-149-5p is associated with cellular migration, proliferation and apoptosis in renal cell carcinoma.

    PubMed

    Jin, Lu; Li, Yifan; Liu, Jiaju; Yang, Shangqi; Gui, Yaoting; Mao, Xiangming; Nie, Guohui; Lai, Yongqing

    2016-06-01

    Several studies have recently explored the role of microRNAs (miRNAs, miRs) in the tumorigenesis of various types of cancer. miRNAs have been reported to be involved in numerous cell processes, including cell apoptosis, proliferation and migration, thus suggesting that miRNAs may have an important role in cancer progression. Downregulation of miR-149-5p has been detected in RCC tissues by microarray profiling; however, its expression and function in RCC has yet to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction was performed to detect the expression levels of miR‑149‑5p in RCC tissues and paired normal tissues. In order to determine whether miR-149-5p was able to regulate cell proliferation, apoptosis or migration, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometric and wound healing assays were conducted. The results demonstrated that miR‑149‑5p was significantly downregulated in RCC tissues compared with in normal tissues (P<0.05). The restoration of miR-149-5p expression using synthetic mimics suppressed cell proliferation and migration, and promoted cell apoptosis. These results indicated that miR‑149‑5p may act as a tumor suppressor in RCC. The present study is the first, to the best of our knowledge, to identify miR‑149‑5p as a tumor suppressor in RCC. Future studies will be focused on the potential role of miR‑149‑5p as a biomarker for the early detection and prognostic prediction of RCC, and as a therapeutic target in RCC. In addition, further exploration regarding the pathways underlying the effects of miR‑149‑5p in RCC is required. PMID:27121091

  3. Binding of sFRP-3 to EGF in the Extra-Cellular Space Affects Proliferation, Differentiation and Morphogenetic Events Regulated by the Two Molecules

    PubMed Central

    Tosoni, Daniela; Borello, Ugo; Sampaolesi, Maurilio; Sciorati, Clara; Cannata, Stefano; Clementi, Emilio; Brunelli, Silvia; Cossu, Giulio

    2008-01-01

    Background sFRP-3 is a soluble antagonist of Wnts, widely expressed in developing embryos. The Wnt gene family comprises cysteine-rich secreted ligands that regulate cell proliferation, differentiation, organogenesis and oncogenesis of different organisms ranging from worms to mammals. In the canonical signal transduction pathway Wnt proteins bind to the extracellular domain of Frizzled receptors and consequently recruit Dishevelled (Dsh) to the cell membrane. In addition to Wnt membrane receptors belonging to the Frizzled family, several other molecules have been described which share homology in the CRD domain and lack the putative trans-membrane domain, such as sFRP molecules (soluble Frizzled Related Protein). Among them, sFRP-3 was originally isolated from bovine articular cartilage and also as a component of the Spemann organizer. sFRP-3 blocks Wnt-8 induced axis duplication in Xenopus embryos and binds to the surface of cells expressing a membrane-anchored form of Wnt-1. Injection of sFRP-3 mRNA blocks expression of XMyoD mRNA and leads to embryos with enlarged heads and shortened trunks. Methodology/Principal Findings Here we report that sFRP-3 specifically blocks EGF-induced fibroblast proliferation and foci formation. Over-expression of sFRP-3 reverts EGF-mediated inhibition of hair follicle development in the mouse ectoderm while its ablation in Xenopus maintains EGF-mediated inhibition of ectoderm differentiation. Conversely, over-expression of EGF reverts the inhibition of somitic myogenesis and axis truncation in Xenopus and mouse embryos caused by sFRP-3. In vitro experiments demonstrated a direct binding of EGF to sFRP-3 both on heparin and on the surface of CHO cells where the molecule had been membrane anchored. Conclusions/Significance sFRP-3 and EGF reciprocally inhibit their effects on cell proliferation, differentiation and morphogenesis and indeed are expressed in contiguous domains of the embryo, suggesting that in addition to their

  4. Inhibition of Macrophage CD36 Expression and Cellular Oxidized Low Density Lipoprotein (oxLDL) Accumulation by Tamoxifen: A PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR (PPAR)γ-DEPENDENT MECHANISM.

    PubMed

    Yu, Miao; Jiang, Meixiu; Chen, Yuanli; Zhang, Shuang; Zhang, Wenwen; Yang, Xiaoxiao; Li, Xiaoju; Li, Yan; Duan, Shengzhong; Han, Jihong; Duan, Yajun

    2016-08-12

    Macrophage CD36 binds and internalizes oxidized low density lipoprotein (oxLDL) to facilitate foam cell formation. CD36 expression is activated by peroxisome proliferator-activated receptor γ (PPARγ). Tamoxifen, an anti-breast cancer medicine, has demonstrated pleiotropic functions including cardioprotection with unfully elucidated mechanisms. In this study, we determined that treatment of ApoE-deficient mice with tamoxifen reduced atherosclerosis, which was associated with decreased CD36 and PPARγ expression in lesion areas. At the cellular level, we observed that tamoxifen inhibited CD36 protein expression in human THP-1 monocytes, THP-1/PMA macrophages, and human blood monocyte-derived macrophages. Associated with decreased CD36 protein expression, tamoxifen reduced cellular oxLDL accumulation in a CD36-dependent manner. At the transcriptional level, tamoxifen decreased CD36 mRNA expression, promoter activity, and the binding of the PPARγ response element in CD36 promoter to PPARγ protein. Tamoxifen blocked ligand-induced PPARγ nuclear translocation and CD36 expression, but it increased PPARγ phosphorylation, which was due to that tamoxifen-activated ERK1/2. Furthermore, deficiency of PPARγ expression in macrophages abolished the inhibitory effect of tamoxifen on CD36 expression or cellular oxLDL accumulation both in vitro and in vivo Taken together, our study demonstrates that tamoxifen inhibits CD36 expression and cellular oxLDL accumulation by inactivating the PPARγ signaling pathway, and the inhibition of macrophage CD36 expression can be attributed to the anti-atherogenic properties of tamoxifen. PMID:27358406

  5. Increased DNA fragmentation and ultrastructural changes in fibromyalgic muscle fibres

    PubMed Central

    Sprott, H; Salemi, S; Gay, R; Bradley, L; Alarcon, G; Oh, S; Michel, B; Gay, S

    2004-01-01

    Objective: To determine whether there is evidence of increased DNA fragmentation and ultrastructural changes in muscle tissue of patients with fibromyalgia (FM) compared with healthy controls. Methods: Muscle tissues from 10 community residents with FM and 10 age and sex matched healthy controls were examined "blindly" for the presence of DNA fragmentation by two different methods: terminal deoxynucleotidyl transferase (TdT) staining (TUNEL) and the FragEL-Klenow DNA fragmentation detection kit. Ultrastructural analysis of tissue was performed by electron microscopy. Results: DNA fragmentation was detected by both methods in 55.4 (SEM 2.5)% of the nuclei in muscle tissue of patients with FM compared with 16.1 (4.1)% (p<0.001) of the nuclei in healthy controls. Contrary to expectation, no typical features of apoptosis could be detected by electron microscopy. The myofibres and actin filaments were disorganised and lipofuscin bodies were seen; glycogen and lipid accumulation were also found. The number of mitochondria was significantly lower in patients with FM than in controls and seemed to be morphologically altered. Conclusion: The ultrastructural changes described suggest that patients with FM are characterised by abnormalities in muscle tissue that include increased DNA fragmentation and changes in the number and size of mitochondria. These cellular changes are not signs of apoptosis. Persistent focal contractions in muscle may contribute to ultrastructural tissue abnormalities as well as to the induction and/or chronicity of nociceptive transmission from muscle to the central nervous system. PMID:14962957

  6. E2F1-Mediated Upregulation of p19INK4d Determines Its Periodic Expression during Cell Cycle and Regulates Cellular Proliferation

    PubMed Central

    Carcagno, Abel L.; Marazita, Mariela C.; Ogara, María F.; Ceruti, Julieta M.; Sonzogni, Silvina V.; Scassa, María E.; Giono, Luciana E.; Cánepa, Eduardo T.

    2011-01-01

    Background A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. Methodology/Principal Findings In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. Conclusions/Significance The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an

  7. Down-regulation of pancreatic and duodenal homeobox-1 by somatostatin receptor subtype 5: a novel mechanism for inhibition of cellular proliferation and insulin secretion by somatostatin

    PubMed Central

    Zhou, Guisheng; Sinnett-Smith, Jim; Liu, Shi-He; Yu, Juehua; Wu, James; Sanchez, Robbi; Pandol, Stephen J.; Abrol, Ravinder; Nemunaitis, John; Rozengurt, Enrique; Brunicardi, F. Charles

    2014-01-01

    Somatostatin (SST) is a regulatory peptide and acts as an endogenous inhibitory regulator of the secretory and proliferative responses of target cells. SST’s actions are mediated by a family of seven transmembrane domain G protein-coupled receptors that comprise five distinct subtypes (SSTR1-5). SSTR5 is one of the major SSTRs in the islets of Langerhans. Homeodomain-containing transcription factor pancreatic and duodenal homeobox-1 (PDX-1) is essential for pancreatic development, β cell differentiation, maintenance of normal β cell functions in adults and tumorigenesis. Recent studies show that SSTR5 acts as a negative regulator for PDX-1 expression and that SSTR5 mediates somatostatin’s inhibitory effect on cell proliferation and insulin expression/excretion through down-regulating PDX-1 expression. SSTR5 exerts its inhibitory effect on PDX-1 expression at both the transcriptional level by down-regulating PDX-1 mRNA and the post-translational level by enhancing PDX-1 ubiquitination. Identification of PDX-1 as a transcriptional target for SSTR5 may help in guiding the choice of therapeutic cancer treatments. PMID:25009500

  8. ATXN7L3 and ENY2 Coordinate Activity of Multiple H2B Deubiquitinases Important for Cellular Proliferation and Tumor Growth.

    PubMed

    Atanassov, Boyko S; Mohan, Ryan D; Lan, Xianjiang; Kuang, Xianghong; Lu, Yue; Lin, Kevin; McIvor, Elizabeth; Li, Wenqian; Zhang, Ying; Florens, Laurence; Byrum, Stephanie D; Mackintosh, Samuel G; Calhoun-Davis, Tammy; Koutelou, Evangelia; Wang, Li; Tang, Dean G; Tackett, Alan J; Washburn, Michael P; Workman, Jerry L; Dent, Sharon Y R

    2016-05-19

    Histone H2B monoubiquitination (H2Bub1) is centrally involved in gene regulation. The deubiquitination module (DUBm) of the SAGA complex is a major regulator of global H2Bub1 levels, and components of this DUBm are linked to both neurodegenerative diseases and cancer. Unexpectedly, we find that ablation of USP22, the enzymatic center of the DUBm, leads to a reduction, rather than an increase, in global H2bub1 levels. In contrast, depletion of non-enzymatic components, ATXN7L3 or ENY2, results in increased H2Bub1. These observations led us to discover two H2Bub1 DUBs, USP27X and USP51, which function independently of SAGA and compete with USP22 for ATXN7L3 and ENY2 for activity. Like USP22, USP51 and USP27X are required for normal cell proliferation, and their depletion suppresses tumor growth. Our results reveal that ATXN7L3 and ENY2 orchestrate activities of multiple deubiquitinating enzymes and that imbalances in these activities likely potentiate human diseases including cancer. PMID:27132940

  9. HER kinase axis receptor dimer partner switching occurs in response to EGFR tyrosine kinase inhibition despite failure to block cellular proliferation.

    PubMed

    Jain, Anjali; Penuel, Elicia; Mink, Sheldon; Schmidt, Joanna; Hodge, Amanda; Favero, Kristin; Tindell, Charles; Agus, David B

    2010-03-01

    The human epidermal receptor (HER) axis consists of a dynamic, interconnected family of receptors that make critical contributions to a number of malignancies. Therapeutics targeting epidermal growth factor receptor (EGFR) are unable to effectively inhibit tumor growth in a majority of cases. These tumors are assumed to possess primary resistance to anti-EGFR therapies, but the consequence of inhibiting EGFR in these tumors is unclear. We established isogenic cell lines by prolonged gefitinib treatment at concentrations that are in excess of that which is required for complete EGFR kinase inhibition but only minimally affected growth. Subsequently, we monitored the ligand-dependent HER profiles based on receptor expression, phosphorylation, and dimerization in conjunction with measurements of cellular susceptibility to gefitinib. Chronic EGFR kinase inhibition rapidly switched the HER network from dependence on EGFR to HER2. However, both receptors activated the critical signaling proteins AKT and mitogen-activated protein kinase, and in both cases, HER3 was the common association partner. Remarkably, the switch in receptor dimers caused diminished susceptibility to EGFR-targeted inhibitors gefitinib and cetuximab but acquired susceptibility to the HER2-targeted inhibitor pertuzumab. Overall, our study indicates that the EGFR pathway is responsive to EGFR inhibiting therapies that are not dependent on EGFR for their growth and survival, thus challenging the current definition of primary therapeutic resistance. Furthermore, EGFR kinase inhibition induces HER kinase receptors to engage in alternative dimerization that can ultimately influence therapeutic selection and responsiveness. PMID:20160029

  10. HER-kinase Axis Receptor Dimer Partner Switching Occurs in Response to EGFR Tyrosine Kinase Inhibition Despite Failure to Block Cellular Proliferation

    PubMed Central

    Jain, Anjali; Penuel, Elicia; Mink, Sheldon; Schmidt, Joanna; Hodge, Amanda; Favero, Kristin; Tindell, Charles; Agus, David B.

    2010-01-01

    The HER-axis consists of a dynamic, interconnected family of receptors that make critical contributions to a number of malignancies. Therapeutics targeting EGFR, are unable to effectively inhibit tumor growth in a majority of cases. These tumors are assumed to possess primary resistance to anti-EGFR therapies but the consequence of inhibiting EGFR in these tumors is unclear. We established isogenic cell lines by prolonged gefitinib treatment at concentrations that are in excess of that which is required for complete EGFR kinase inhibition but only minimally effected growth. Subsequently, we monitored the ligand-dependent HER profiles based on receptor expression, phosphorylation and dimerization in conjunction with measurements of cellular susceptibility to gefitinib. Chronic EGFR kinase inhibition rapidly switched the HER network from dependence on EGFR to HER2. However, both receptors activated the critical signaling proteins, AKT and MAPK and in both cases HER3 was the common association partner. Remarkably, the switch in receptor dimers caused diminished susceptibility to EGFR-targeted inhibitors, gefitinib and cetuximab, but acquired susceptibility to the HER2-targeted inhibitor, pertuzumab. Overall, our study indicates that the EGFR pathway is responsive to EGFR inhibiting therapies that are not dependent on EGFR for their growth and survival thus challenging the current definition of primary therapeutic resistance. Further, EGFR kinase inhibition induces HER-kinase receptors to engage in alternative dimerization that can ultimately influence therapeutic selection and responsiveness. PMID:20160029

  11. Comparative sperm ultrastructure in Nemertea.

    PubMed

    von Döhren, J; Beckers, P; Vogeler, R; Bartolomaeus, T

    2010-07-01

    Although the monophyly of Nemertea is strongly supported by unique morphological characters and results of molecular phylogenetic studies, their ingroup relationships are largely unresolved. To contribute solving this problem we studied sperm ultrastructure of 12 nemertean species that belong to different subtaxa representing the commonly recognized major monophyletic groups. The study yielded a set of 26 characters with an unexpected variation among species of the same genus (Tubulanus and Procephalothrix species), whereas other species varied in metric values or only one character state (Ramphogordius). In some species, the sperm nucleus has grooves (Zygonemertes virescens, Amphiporus imparispinosus) that may be twisted and give a spiral shape to the sperm head (Paranemertes peregrina, Emplectonema gracile). To make the characters from sperm ultrastructure accessible for further phylogenetic analyses, they were coded in a character matrix. Published data for eight species turned out to be sufficiently detailed to be included. Comparative evaluation of available information on the sperm ultrastructure suggests that subtaxa of Heteronemertea and Hoplonemertea are supported as monophyletic by sperm morphology. However, the data do not provide information on the existing contradictions regarding the internal relationships of "Palaeonemertea." Nevertheless, our study provides evidence that sperm ultrastructure yields numerous potentially informative characters that will be included in upcoming phylogenetic analyses. PMID:20544873

  12. Effects of soft x-ray irradiation on cell ultrastructure

    NASA Astrophysics Data System (ADS)

    Ford, Thomas W.; Page, Anton M.; Foster, Guy F.; Stead, Anthony D.

    1993-01-01

    The future of x-ray microscopy lies mainly in its potential for imaging fresh, hydrated biological material at a resolution superior to that of light microscopy. For the image to be accepted as representing the cellular organization of the living cell, it is essential that artefacts are not introduced as a result of the image collection system. One possible source of artefacts is cellular damage resulting form the irradiation of the material with soft x rays. Cells of the unicellular alga Chlorella have been examined by transmission electron microscopy (TEM) following exposure to different doses of monochromatic (380 eV) soft x rays. Extreme ultrastructural damage has been detected following doses of 103 - 104 Gy, in particular loss of cellular membranes such as the internal thylakoid membranes of the chloroplast. This is discussed in relation to dosage commonly used for imaging by soft x-ray microscopy.

  13. Ultrastructure processing of advanced ceramics

    SciTech Connect

    Mackenzie, J.D.; Ulrich, D.R.

    1988-01-01

    Experimental investigations and applications of advanced ceramics are discussed in reviews and reports presented at the Third International Conference on Ultrastructure Processing of Ceramics, Glasses, and Composites held in San Diego in February 1987. Sections are devoted to precursors and chemistry for ultrastructure processing; sol-gel science and technology; powders and colloids; advanced ceramics; and composites, new materials, and techniques. Particular attention is given to silicon oxynitride and sialon ceramics from organosilicon powders, fluoropolymer-modified silicate glasses, Raman and FTIR spectroscopy of rapid sol-gel processes, a low-temperature route to high-purity Ti/Zr/Hf diboride powders and films, and sol-gel methods for SiO2 optical-fiber coatings. Diagrams, drawings, graphs, micrographs, and tables of numerical data are included.

  14. Ultrastructural Analysis of Drosophila Ovaries by Electron Microscopy.

    PubMed

    Hurd, Thomas R; Sanchez, Carlos G; Teixeira, Felipe K; Petzold, Chris; Dancel-Manning, Kristen; Wang, Ju-Yu S; Lehmann, Ruth; Liang, Feng-Xia A

    2015-01-01

    The Drosophila melanogaster ovary is a powerful, genetically tractable system through which one can elucidate the principles underlying cellular function and organogenesis in vivo. In order to understand the intricate process of oogenesis at the subcellular level, microscopic analysis with the highest possible resolution is required. In this chapter, we describe the preparation of ovaries for ultrastructural analysis using transmission electron microscopy and focused ion beam scanning electron microscopy. We discuss and provide protocols for chemical fixation of Drosophila ovaries that facilitate optimal imaging with particular attention paid to preserving and resolving mitochondrial membrane morphology and structure. PMID:26324436

  15. Ultrastructural Analysis of Drosophila Ovaries by Electron Microscopy

    PubMed Central

    Hurd, Thomas R.; Sanchez, Carlos G.; Teixeira, Felipe K.; Petzold, Chris; Dancel-Manning, Kristen; Wang, Ju-Yu S.; Lehmann, Ruth; Liang, Feng-Xia A.

    2016-01-01

    i. Summary The Drosophila melanogaster ovary is a powerful, genetically tractable system through which one can elucidate the principles underlying cellular function and organogenesis in vivo. In order to understand the intricate process of oogenesis at the subcellular level, microscopic analysis with the highest possible resolution is required. In this chapter, we describe the preparation of ovaries for ultrastructural analysis using transmission electron microscopy and focused ion beam scanning electron microscopy. We discuss and provide protocols for chemical fixation of Drosophila ovaries that facilitate optimal imaging with particular attention paid to preserving and resolving mitochondrial membrane morphology and structure. PMID:26324436

  16. Characterization of Septin Ultrastructure in Budding Yeast Using Electron Tomography

    PubMed Central

    Bertin, Aurélie; Nogales, Eva

    2015-01-01

    Summary Septins are essential for the completion of cytokinesis. In budding yeast, Saccharomyces cerevisiae, septins are located at the bud neck during mitosis and are closely connected to the inner plasma membrane. In vitro, yeast septins have been shown to self-assemble into a variety of filamentous structures, including rods, paired filaments, bundles and rings [1–3]. Using electron tomography of freeze-substituted section and cryo-electron tomography of frozen sections, we determined the three dimensional organization of the septin cytoskeleton in dividing budding yeast with molecular resolution [4,5]. Here we describe the detailed procedures used for our characterization of the septin cellular ultrastructure. PMID:26519309

  17. The acquired immunodeficiency syndrome: an ultrastructural study.

    PubMed

    Sidhu, G S; Stahl, R E; el-Sadr, W; Cassai, N D; Forrester, E M; Zolla-Pazner, S

    1985-04-01

    Blood and a variety of tissues from 97 patients with the acquired immunodeficiency syndrome (AIDS) and 25 with the AIDS prodrome were studied ultrastructurally. Tubuloreticular structures (TRS) were found in 85 per cent of the patients with AIDS and in 92 per cent of those with the prodrome. Test tube and ring-shaped forms (TRF), found in 41 per cent of the patients with AIDS and in 8 per cent of those with the prodrome, increased with disease progression. Among the patients with AIDS, as the number of sites examined per case increased, the incidence of TRS and TRF tended to approach 100 per cent, suggesting that they are present in all patients with AIDS. Other changes seen frequently were immunologic capping of blood lymphocytes, intramitochondrial iron in blood reticulocytes and marrow normoblasts, megakaryocytic immaturity and platelet phagocytosis, collections of membranous rings in hepatocytic cytoplasm, suggestive of non-A, non-B hepatitis, and proliferations and engorgement of hepatic Ito cells with lipid. The data suggest that TRS and TRF can be used as diagnostic and prognostic markers. PMID:3872253

  18. Cryosurgery: ultrastructural changes in pancreas tissue after low temperature exposure.

    PubMed

    Korpan, N N

    2007-04-01

    A number of theoretical and experimental studies, both in vitro and in vivo, have been performed to explain the action of low temperatures on tissue. It is now evident that the thermal parameters used in the past for freezing during cryosurgery were not precise; this may have resulted in the failure of treatment. For the first time, this report describes the early ultrastructural features of pancreatic parenchyma after low temperature exposure, i.e., cryosurgery, in vivo. We demonstrate the effect of freeze-thawing processes using temperatures of various intensities. The cryosurgical response of pancreas parenchyma, i.e., ultrastructural cellular changes in pancreas tissue, was investigated. The electronic microscopic analysis showed that, after local cryodestruction at temperatures of -80 degrees C and -180 degrees C, similar processes occurred within the pancreas tissue in the early postcryosurgical phase -- immediately and up to 24 hours after low temperature exposure on tissue. The exocrine pancreatic cells in the center of the cryozone changed upon thawing. Ultrastructural changes in the exocrine pancreatic cells, where the first signs of dystrophic processes had been noticed, were increased. These ultrastructural changes in the pancreatic cells provide a platform to better understand the mechanisms of damage and the pathogenesis of frostbite after cryosurgery. The properties of the pancreas parenchyma response after low temperature exposure provide important insights into the mechanisms of damage and the cryogenic lesion immediately after thawing in cryosurgery. Our new insights prove on the cell level that suddenly and progressively damaged pancreatic cells in the postcryosurgical zone lead to aseptic cryonecrosis and then to aseptic cryoapoptosis of vital normal tissue. The vascular capillary changes and circulatory stagnation demonstrate the anti-angiogenesis mechanism, which, together with cryoaponecrosis and cryoapoptosis, are some of the main mechanisms

  19. Imaging Cellular Proliferation During Chemo-Radiotherapy: A Pilot Study of Serial {sup 18}F-FLT Positron Emission Tomography/Computed Tomography Imaging for Non-Small-Cell Lung Cancer

    SciTech Connect

    Everitt, Sarah; Hicks, Rodney J.; Ball, David; Kron, Tomas; Schneider-Kolsky, Michal; Walter, Tania; Binns, David; Mac Manus, Michael

    2009-11-15

    Purpose: To establish whether {sup 18}F-3'-deoxy-3'-fluoro-L-thymidine ({sup 18}F-FLT) can monitor changes in cellular proliferation of non-small-cell lung cancer (NSCLC) during radical chemo-radiotherapy (chemo-RT). Methods and Materials: As part of a prospective pilot study, 5 patients with locally advanced NSCLC underwent serial {sup 18}F-FLT positron emission tomography (PET)/computed tomography (CT) scans during treatment. Baseline {sup 18}F-FLT PET/CT scans were compared with routine staging {sup 18}F-FDG PET/CT scans. Two on-treatment {sup 18}F-FLT scans were performed for each patient on Days 2, 8, 15 or 29, providing a range of time points for response assessment. Results: In all 5 patients, baseline lesional uptake of {sup 18}F-FLT on PET/CT corresponded to staging {sup 18}F-FDG PET/CT abnormalities. {sup 18}F-FLT uptake in tumor was observed on five of nine (55%) on-treatment scans, on Days 2, 8 and 29, but not Day 15. A 'flare' of {sup 18}F-FLT uptake in the primary tumor of one case was observed after 2 Gy of radiation (1.22 x baseline). The remaining eight on-treatment scans demonstrated a mean reduction in {sup 18}F-FLT tumor uptake of 0.58 x baseline. A marked reduction of {sup 18}F-FLT uptake in irradiated bone marrow was observed for all cases. This reduction was observed even after only 2 Gy, and all patients demonstrated a complete absence of proliferating marrow after 10 Gy. Conclusions: This proof of concept study indicates that {sup 18}F-FLT uptake can monitor the distinctive biologic responses of epithelial cancers and highly radiosensitive normal tissue changes during radical chemo-RT. Further studies of {sup 18}F-FLT PET/CT imaging during therapy may suggest that this tracer is useful in developing response-adapted RT for NSCLC.

  20. Toward establishing a morphological and ultrastructural characterization of proembryogenic masses and early somatic embryos of Araucaria angustifolia (Bert.) O. Kuntze.

    PubMed

    Steiner, Neusa; Farias-Soares, Francine L; Schmidt, Éder C; Pereira, Maria L T; Scheid, Bruna; Rogge-Renner, Gladys D; Bouzon, Zenilda L; Schmidt, Daniela; Maldonado, Sara; Guerra, Miguel P

    2016-03-01

    Somatic embryogenesis is a morphogenetic route useful for the study of embryonic development, as well as the large-scale propagation of endangered species, such as the Brazilian pine (Araucaria angustifolia). In the present study, we investigated the morphological and ultrastructural organization of A. angustifolia somatic embryo development by means of optical and electron microscopy. The proembryogenic stage was characterized by the proliferation of proembryogenic masses (PEMs), which are cellular aggregates composed of embryogenic cells (ECs) attached to suspensor-like cells (SCs). PEMs proliferate through three developmental stages, PEM I, II, and III, by changes in the number of ECs and SCs. PEM III-to-early somatic embryo (SE) transition was characterized by compact clusters of ECs growing out of PEM III, albeit still connected to it by SCs. Early SEs showed a dense globular embryonic mass (EM) and suspensor region (SR) connected by embryonic tube cells (TCs). By comparison, early somatic and zygotic embryos showed similar morphology. ECs are round with a large nucleus, nucleoli, and many cytoplasmic organelles. In contrast, TCs and SCs are elongated and vacuolated with cellular dismantling which is associated with programmed cell death of SCs. Abundant starch grains were observed in the TCs and SCs, while proteins were more abundant in the ECs. Based on the results of this study, a fate map of SE development in A. angustifolia is, for the first time, proposed. Additionally, this study shows the cell biology of SE development of this primitive gymnosperm which may be useful in evolutionary studies in this area. PMID:25968333

  1. Correlated light and electron microscopy: ultrastructure lights up!

    PubMed

    de Boer, Pascal; Hoogenboom, Jacob P; Giepmans, Ben N G

    2015-06-01

    Microscopy has gone hand in hand with the study of living systems since van Leeuwenhoek observed living microorganisms and cells in 1674 using his light microscope. A spectrum of dyes and probes now enable the localization of molecules of interest within living cells by fluorescence microscopy. With electron microscopy (EM), cellular ultrastructure has been revealed. Bridging these two modalities, correlated light microscopy and EM (CLEM) opens new avenues. Studies of protein dynamics with fluorescent proteins (FPs), which leave the investigator 'in the dark' concerning cellular context, can be followed by EM examination. Rare events can be preselected at the light microscopy level before EM analysis. Ongoing development-including of dedicated probes, integrated microscopes, large-scale and three-dimensional EM and super-resolution fluorescence microscopy-now paves the way for broad CLEM implementation in biology. PMID:26020503

  2. Assessment of murine bone ultrastructure using synchrotron light: towards nano-computed tomography

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Voide, Romain; Stauber, Martin; Stampanoni, Marco; Donahue, Leah Rae; Wyss, Peter; Sennhauser, Urs; Müller, Ralph

    2006-08-01

    To describe the different aspects of bone quality, we follow a hierarchical approach and assess bone tissue properties in different regimes of spatial resolution, beginning at the organ level and going down to cellular dimensions. For these purposes we developed different synchrotron radiation (SR) based computed-tomography (CT) methods to assess murine bone ultrastructure. In a first step, a tubular system and the osteocyte lacunar system within murine cortical bone have been established as novel ultrastructural quantitative traits. Results in two mouse strains showed that morphometry of these quantitative traits was dependent on strain and partially on gender, and that their scaling behavior with bone size was fundamentally different. In a second step, we explored bone competence on an ultrastructural level and related our findings to the two ultrastructural quantitative traits introduced before. We showed that SR CT imaging is a powerful tool to investigate the initiation and propagation of microcracks, which may alter bone quality and may lead to increased fracture risk by means of microdamage accumulation. In summary, investigation of ultrastructural bone tissue properties will eventually lead to a better understanding of bone quality and its relative contribution to bone competence.

  3. Platelet satellitism: an ultrastructural study.

    PubMed Central

    Payne, C. M.

    1981-01-01

    The ultrastructural morphology of platelet-polymorph (platelet-polymorphonuclear leukocyte) rosettes was investigated in EDTA-anticoagulated blood obtained from two patients who exhibited the phenomenon of platelet satellitism. Most of the platelet profiles were attached to the polymorph surface by broad areas of contact. Examination of these broad areas of contact at high magnification revealed an intercellular material of low electron density. This material appeared to form strands, which bridged the intercellular space and spanned the entire area formed by the apposing plasma membranes. Phagocytosis of entire platelets was only observed in 1 case. The platelet profiles that participated in rosette formation revealed a large number of glycogen particles, compared with unattached platelets. Ultrastructural examination of "stress" platelets obtained from five normal subjects treated with steroids similarly showed a large number of glycogen particles, although no rosette formation or phagocytosis of platelets was observed. The etiology of platelet satellitism is discussed. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7223859

  4. From proliferation to proliferation: monocyte lineage comes full circle

    PubMed Central

    Swirski, Filip K.; Hilgendorf, Ingo; Robbins, Clinton S.

    2014-01-01

    Monocytes are mononuclear circulating phagocytes that originate in the bone marrow and give rise to macrophages in peripheral tissue. For decades, our understanding of monocyte lineage was bound to a stepwise model that favored an inverse relationship between cellular proliferation and differentiation. Sophisticated molecular and surgical cell tracking tools have transformed our thinking about monocyte topo-ontogeny and function. Here, we discuss how recent studies focusing on progenitor proliferation and differentiation, monocyte mobilization and recruitment, and macrophage differentiation and proliferation are reshaping knowledge of monocyte lineage in steady state and disease. PMID:24435095

  5. Ultrastructural changes during the fatigue of bone

    NASA Astrophysics Data System (ADS)

    Kohn, David H.

    2006-07-01

    Repetitive mechanical loading of bone can lead to ultrastructural-level damage, which can lead to fracture if not repaired. Skeletal fractures result not only from a loss in bone mass, but also because of alterations in tissue quality. Therefore, it is important to also delineate how changes in tissue ultrastructure affect the mechanistic response of bone to its physical environment. In this overview, factors affecting tissue quality, in particular fatigue resistance, are reviewed, followed by examples of recent work that has identified ultrastructural and compositional changes that occur in bone during fatigue.

  6. Ultrastructural Analysis of Candida albicans When Exposed to Silver Nanoparticles

    PubMed Central

    Vazquez-Muñoz, Roberto; Avalos-Borja, Miguel; Castro-Longoria, Ernestina

    2014-01-01

    Candida albicans is the most common fungal pathogen in humans, and recently some studies have reported the antifungal activity of silver nanoparticles (AgNPs) against some Candida species. However, ultrastructural analyses on the interaction of AgNPs with these microorganisms have not been reported. In this work we evaluated the effect of AgNPs on C. albicans, and the minimum inhibitory concentration (MIC) was found to have a fungicidal effect. The IC50 was also determined, and the use of AgNPs with fluconazole (FLC), a fungistatic drug, reduced cell proliferation. In order to understand how AgNPs interact with living cells, the ultrastructural distribution of AgNPs in this fungus was determined. Transmission electron microscopy (TEM) analysis revealed a high accumulation of AgNPs outside the cells but also smaller nanoparticles (NPs) localized throughout the cytoplasm. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of intracellular silver. From our results it is assumed that AgNPs used in this study do not penetrate the cell, but instead release silver ions that infiltrate into the cell leading to the formation of NPs through reduction by organic compounds present in the cell wall and cytoplasm. PMID:25290909

  7. Scrotal angiokeratoma (Fordyce): histopathological and ultrastructural findings.

    PubMed

    Gioglio, L; Porta, C; Moroni, M; Nastasi, G; Gangarossa, I

    1992-01-01

    Bioptic findings related to four cases of scrotal angiokeratoma-Fordyce, were studied under light and electron microscopy. A particular heterogeneity of the structural and ultrastructural patterns typical of this lesion was thus observed. Light microscopy study pointed out, in particular, different degrees of dilation of papillary vessels, whereas ultrastructural study highlighted marked alterations of endothelial cells with structural and quantitative modifications of cytoplasmic organelles. PMID:1576434

  8. Ultrastructural characteristics of type A epithelioid cells during BCG-granulomatosis and treatment with lysosomotropic isoniazid.

    PubMed

    Shkurupii, V A; Kozyaev, M A; Nadeev, A P

    2006-04-01

    We studied BCG-granulomas, their cellular composition, and ultrastructure of type A epithelioid cells in the liver of male BALB/c mice with spontaneous granulomatous inflammation. The animals received free isoniazid or isoniazid conjugated with lysosomotropic intracellularly prolonged matrix (dialdehyde dextran, molecular weight 65-75 kDa). Lysosomotropic isoniazid was accumulated in the vacuolar apparatus of epithelioid cells and produced a stimulatory effect on plastic processes in these cells. PMID:17152378

  9. [Ultrastructural study of embryonic development in Grantia compressa F. (Porifera, Calcarea)].

    PubMed

    Gallissian, M F

    1983-01-01

    The embryonic development of Grantia compressa is studied by means of the electron microscope from the blastula inside the mesenchyme to the mature amphi-blastula released in the excurrent canals. The study of the different cellular categories of the embryon shows the distribution of the vitellin inclusions and their evolution. The ultrastructure of the "cellules en croix" is not in favour of a photoreceptor part. PMID:6639044

  10. Ultrastructural alterations during embryonic rats' lung development caused by ozone.

    PubMed

    López, Irma; Sánchez, Ivonne; Bizarro, Patricia; Acevedo, Sandra; Ustarroz, Martha; Fortoul, Teresa

    2008-01-01

    Ozone (O3) is an oxidizing agent that acts on phospholipids, proteins and sugars of cellular membranes producing free radicals, which cause oxidative damages. The O3 exposure has been used as a model to study oxidative stress, in which the respiratory airways represent the entrance to the organism. In this study, ultrastructural alterations were identified at the bronchiolar level during the intra-uterine lung development, using an O3 exposure model in pregnant rats during 18, 20 and 21 days of gestation. Twelve pregnant Wistar rats, six controls and six exposed to 1 ppm O3 inhalation during 12 h per day, were used. The rats were sacrificed at gestational days 18, 20 and 21; the fetuses were obtained and their lungs dissected. The ultrastructural analysis evidenced swollen mitochondria, cytoplasmic vacuolization of the epithelial cells and structural disorder caused by the oxidative stress. At gestation day 20, flake-off epithelial cells and laminar bodies in the bronchiolar lumen were observed. In the 21-gestation-day group, the mitochondria were edematous and their cristae were disrupted by the damage caused in mitochondrial membranes. PMID:18083976

  11. Ultrastructural changes of goat corpus luteum during the estrous cycle.

    PubMed

    Jiang, Yi-Fan; Hsu, Meng-Chieh; Cheng, Chiung-Hsiang; Tsui, Kuan-Hao; Chiu, Chih-Hsien

    2016-07-01

    The present study was designed to study the ultrastructure of goat corpora lutea (CL, n=10) and structural changes as related to steroidogenic functions during the estrous cycle. The reproduction status of goats was estimated by analyzing serum progesterone concentrations. The CL at various stages was surgically collected. To characterize ultrastructural features associated with steroidogenesis, tissue and cellular structures were studied. Blood supplies were examined based on features of the endothelial cells and capillary structures in the CL. Activated endothelial cells and developing vessels were observed in the early stage, whereas mature endothelial cells, accumulating extracellular matrix fibers, and stabilized vessels were observed in the middle and late stages of assessment. In the late stage of assessment, shrunken goat luteal cells scattered around the capillaries were detected and formed circular regression areas. Features of autophagy and luteal cell apoptosis were noted. In large luteal cells, steroidogenic organelles were present, including microvillar channels, endoplasmic reticulum, and mitochondria. Conformational changes in the endoplasmic reticulum and increased mitochondria with tubular cristae were observed in the early-middle CL transitions. In contrast, mitochondria swelled and the cristae transformed to the lamellar type in the late stage, suggesting that organelle plasticity could contribute to steroidogenesis in goat CL. In conclusion, results suggest angiogenesis occurs in early developing CL and programmed cell death occurred in the late stage of CL assessment in the present study. Structures and quantiles of steroidogenic organelles are correlated with the steroidogenic functions in goats. PMID:27102356

  12. Ultrastructural study of host-parasite relationship and pathogenicity of Eimeria sp. infecting Libyan Jird (Meriones libycus) (Lichtenstein, 1828).

    PubMed

    Kassem, Hamed H; Nass, Sedigh Ahmed

    2013-04-01

    The relationship of Eimeria sp. and its host fat LibyanJird (Meriones libycus) was studied on an ultrastructural level. The host cellular organelles (nucleus, mitochondria, endoplasmic reticulum and golgi apparatus) and the changes of its infected intestinal epithelial cells during the development of parasitic stages (schizogony and gamogony) were studied and compared with those non-infected cells. The ultrastructures of intravacuolar tubules and folds in the parasitophorous vacuole (P.V.) were described. These fine structures may involve in the transporttation of materials from the host cell to across the parasitovorous vacuole (P.V.). PMID:23697012

  13. Ultrastructure of the adrenocortical homologue in dexamethasone-treated eels.

    PubMed Central

    Bhattacharyya, T K; Butler, D G

    1980-01-01

    The ultrastructural modifications of the adrenocortical homologue (AH) in the North American eel (Anguilla rostrata) were studied following a 10 day treatment with dexamethasone (20 mg/day). The principal changes were: disorganization of smooth endoplasmic reticlum, regression and fragmentation of the Golgi apparatus, and a lowering of matrix density in the mitochondria. Steroid treatment also induced the appearance of numerous cytoplasmic inclusions: (a) lamellated bodies with electron-lucent cores; (b) membranous whorls isolating cytoplasmic regions containing smooth endoplasmic reticulum and mitochondria and (c) complex aggregates showing whorls of membranes, residues of cytoplasmic organelles, and dense matrix. The non-accumulation of lipid droplets in repressed AH cells was noteworthy. These subcellular changes indicate endogenous cellular autophagy in the AH as a result of steroid-induced suppression of ACTH production by the pituitary. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 PMID:7400039

  14. Ultrastructural changes in rat epididymides induced by cowpeas.

    PubMed

    Umapathy, E; Msamati, B C; Torode, M

    1994-01-01

    The ultrastructure of tubular inclusions of caput and cauda epididymides were studied in rats that were fed only cowpeas from weaning (20-22 days old) to 130 days. The results showed significant (p < .001) fall in body weight and testicular, caput, and cauda epididymal weights in the cowpea-fed animals. Although the walls of the epididymides remained intact, the lumina of both segments showed cellular inclusions of various types amid sperm clumps. Unlike controls, where sperm flagella and headpieces were free-floating in lumina of both segments of epididymides, the experimental tubules showed cytoplasmic droplets containing trapped flagella at various stages of disintegration. Other inclusions included multilobular giant cells, lymphocytes, and membrane-bound amorphous bodies. It is proposed that these changes might be due to an altered immune response induced by lectins, one of the antinutritional factors found in cowpeas, which causes epididymal dysfunction and possibly renders these animals infertile. PMID:8166576

  15. Ultrastructurally confirmed myofibrosarcoma: a series of 10 new cases, with a discussion on diagnostic criteria.

    PubMed

    Shenjere, Patrick; Eyden, Brian; Banerjee, S Sankar; Chakrabarty, Bipasha; Shanks, Jonathan H; Sikand, Kanwal A; Menasce, Lia P

    2013-02-01

    Some view ultrastructure as key to myofibrosarcoma diagnosis, whereas others argue that electron microscopy is too little used in contemporary practice to be considered an important diagnostic tool. These views are discussed in the context of 10 ultrastructurally confirmed cases of myofibrosarcoma, some occurring at rare sites such as skin and penis. Patient age ranged from 21 to 83 years, with a 6:4 male to female ratio. Size ranged from 2 to 7.5 cm and all had infiltrative margins. Histologically, all consisted of variably cellular fascicles of spindle cells with mild to moderately pleomorphic nuclei, small punctate nucleoli, and eosinophilic cytoplasm. All cases showed α-smooth muscle actin positivity and 2 showed very focal weak positivity for desmin. Ultrastructurally, the tumor cells contained rough endoplasmic reticulum, mainly peripheral smooth-muscle myofilaments, and fibronectin fibrils or fibronexus junctions at the cell surface. The most confident diagnosis of myofibrosarcoma is provided by ultrastructural examination. However, given the right histological appearance, use of a panel of antibodies that includes α-smooth muscle actin, desmin, and h-caldesmon, serves as an acceptable practical way of diagnosing myofibrosarcoma. PMID:22843641

  16. The influence of silicon on barley growth, photosynthesis and ultra-structure under chromium stress.

    PubMed

    Ali, Shafaqat; Farooq, Muhammad Ahsan; Yasmeen, Tahira; Hussain, Sabir; Arif, Muhammad Saleem; Abbas, Farhat; Bharwana, Saima Aslam; Zhang, Guoping

    2013-03-01

    Silicon (Si) is generally considered as a benefic element for higher plants, especially for those grown under abiotic stressed environments. Current study is carried out in a hydroponic experiment to analyze the effect of Si application on barley growth, photosynthesis and ultra-structure under chromium (Cr) stress. The treatments consisted of three Si (0, 1 and 2mM) and two Cr (0 and 100 μM) levels. The results showed that Si application at both levels enhanced plant growth relative to the control, and alleviated Cr toxicity, reflected by significant increase in growth and photosynthetic parameters, such as SPAD value, net photosynthetic rate (P(n)), cellular CO(2) concentration (C(i)), stomatal conductance (G(s)) and transpiration rate (T(r)), and chlorophyll fluorescence efficiency (Fv/Fm), with 2mM Si having greater effect than 1mM Si. Cr stress caused ultra-structural disorders in leaves, such as uneven swelling of chloroplast, increased amount of plastoglobuli, disintegrated and disappeared thylakoid membranes, increased size and number of starch granules in leaves, and root ultra-structural modification, including increased vacuolar size, presence of Cr metal in cell walls and vacuoles, disruption and disappearance of nucleus. Exogenous Si alleviated these ultra-structural disorders both in roots and leaves. Apparently, Si and Cr behaved antagonistically, indicating that Si could be a candidate for Cr detoxification in crops under Cr-contaminated soil. PMID:23260243

  17. A morphometric analysis of cellular differentiation in caps of primary and lateral roots of Helianthus annuus

    NASA Technical Reports Server (NTRS)

    Moore, R.

    1985-01-01

    In order to determine if patterns of cell differentiation are similar in primary and lateral roots, I performed a morphometric analysis of the ultrastructure of calyptrogen, columella, and peripheral cells in primary and lateral roots of Helianthus annuus. Each cell type is characterized by a unique ultrastructure, and the ultrastructural changes characteristic of cellular differentiation in root caps are organelle specific. No major structural differences exist in the structures of the composite cell types, or in patterns of cell differentiation in caps of primary vs. lateral roots.

  18. Ultrastructure of bovine sperm chromatin.

    PubMed

    Filho, Romualdo Morandi; Beletti, Marcelo Emilio; de Oliveira, Fabio

    2015-12-01

    Mammalian semen chromatin comprises DNA, protamine, and, at lower levels, other proteins. This constitution confers intense compaction to the chromatin, helping to protect the DNA and causing the head of the sperm to be very small, facilitating the safe transport of its genetic contents. It is known that changes in the sperm chromatin compaction lead to fertility problems in bulls, justifying studies of this structure. Although there are theoretical models of sperm chromatin because of its high compaction, there is no morphological evidence of such models. The aim of this study was to demonstrate the ultrastructure of bovine sperm chromatin in an attempt to corroborate the theoretical chromatin models existing today. The isolated bull sperm heads had their chromatin partially unpacked by chemical treatment using sodium dodecyl sulfate (SDS) and dithiothreitol (DTT) and were then embedded in Epon resin. Using an ultramicrotome, ultrathin sections were obtained, which were contrasted with uranyl acetate and lead citrate, and then viewed under transmission electron microscopy. The methodology used allowed the visualization of toroidal structures interconnected by a filamentous nuclear matrix, which is entirely consistent with the most current theoretical models. PMID:26515508

  19. Platelets: production, morphology and ultrastructure.

    PubMed

    Thon, Jonathan N; Italiano, Joseph E

    2012-01-01

    Platelets are anucleate, discoid cells, roughly 2-3 μm in diameter that function primarily as regulators of hemostasis, but also play secondary roles in angiogensis and innate immunity. Although human adults contain nearly one trillion platelets in circulation that are turned over every 8-10 days, our understanding of the mechanisms involved in platelet production is still incomplete. Platelets stem from large (30-100 μm) nucleated cells called megakaryocytes that reside primarily in the bone marrow. During maturation megakaryocytes extend long proplatelet elongations into sinusoidal blood vessels from which platelets ultimately release. During this process, platelets develop a number of distinguishable structural elements including: a delimited plasma membrane; invaginations of the surface membrane that form the open canalicular system (OCS); a closed-channel network of residual endoplasmic reticulum that form the dense tubular system (DTS); a spectrin-based membrane skeleton; an actin-based cytoskeletal network; a peripheral band of microtubules; and numerous organelles including α-granules, dense-granules, peroxisomes, lysosomes, and mitochondria. Proplatelet elongation and platelet production is an elaborate and complex process that defines the morphology and ultrastructure of circulating platelets, and is critical in understanding their increasingly numerous and varied biological functions. PMID:22918725

  20. Ultrastructural and morphological changes in Leishmania (Viannia) braziliensis treated with synthetic chalcones.

    PubMed

    de Mello, Tatiane F P; Cardoso, Bruna M; Bitencourt, Heriberto R; Donatti, Lucélia; Aristides, Sandra M A; Lonardoni, Maria V C; Silveira, Thais G V

    2016-01-01

    Cutaneous leishmaniasis has an estimated incidence of 1.5 million new cases per year and the treatment options available are old, expensive, toxic, and difficult to administer. Chalcones have shown good activity against several species of Leishmania. However few studies have discussed the mechanisms of action and drug target of this group of compounds in Leishmania. The synthetic chalcones that were evaluated in the present study were previously shown to exhibit activity against Leishmania (Viannia) braziliensis. The objective of the present study was to identify ultrastructural and morphological changes in L. (V.) braziliensis after treatment with three synthetic chalcones (1-3). Promastigotes were treated with chalcones 1-3 and evaluated by transmission and scanning electron microscopy. Cellular and nuclear morphology of the parasites, changes in membrane permeability, and DNA fragmentation in agarose electrophoresis gel were also investigated after exposure to synthetic chalcones. All three synthetic chalcones (1-3) induced ultrastructural alterations in mitochondria, intense vacuolization, two nuclei with rounding of parasites, and cellular and nuclear shrinkage. Chalcones 1-3 also induced no changes in membrane permeability, and presence of nucleosome-sized DNA fragments. Synthetic chalcones 1-3 induced ultrastructural and morphological changes, suggesting that chalcones 1-3 induce apoptosis-like cell death. Further studies should be conducted to elucidate other aspects of the action of these chalcones against Leishmania spp. and their use for the treatment of cutaneous leishmaniasis. PMID:26632504

  1. Ultrastructural analysis of the decellularized cornea after interlamellar keratoplasty and microkeratome-assisted anterior lamellar keratoplasty in a rabbit model.

    PubMed

    Hashimoto, Yoshihide; Hattori, Shinya; Sasaki, Shuji; Honda, Takako; Kimura, Tsuyoshi; Funamoto, Seiichi; Kobayashi, Hisatoshi; Kishida, Akio

    2016-01-01

    The decellularized cornea has received considerable attention for use as an artificial cornea. The decellularized cornea is free from cellular components and other immunogens, but maintains the integrity of the extracellular matrix. However, the ultrastructure of the decellularized cornea has yet to be demonstrated in detail. We investigated the influence of high hydrostatic pressure (HHP) on the decellularization of the corneal ultrastructure and its involvement in transparency, and assessed the in vivo behaviour of the decellularized cornea using two animal transplantation models, in relation to remodelling of collagen fibrils. Decellularized corneas were prepared by the HHP method. The decellularized corneas were executed by haematoxylin and eosin and Masson's trichrome staining to demonstrate the complete removal of corneal cells. Transmission electron microscopy revealed that the ultrastructure of the decellularized cornea prepared by the HHP method was better maintained than that of the decellularized cornea prepared by the detergent method. The decellularized cornea after interlamellar keratoplasty and microkeratome-assisted anterior lamellar keratoplasty using a rabbit model was stable and remained transparent without ultrastructural alterations. We conclude that the superior properties of the decellularized cornea prepared by the HHP method were attributed to the preservation of the corneal ultrastructure. PMID:27291975

  2. Ultrastructural analysis of the decellularized cornea after interlamellar keratoplasty and microkeratome-assisted anterior lamellar keratoplasty in a rabbit model

    PubMed Central

    Hashimoto, Yoshihide; Hattori, Shinya; Sasaki, Shuji; Honda, Takako; Kimura, Tsuyoshi; Funamoto, Seiichi; Kobayashi, Hisatoshi; Kishida, Akio

    2016-01-01

    The decellularized cornea has received considerable attention for use as an artificial cornea. The decellularized cornea is free from cellular components and other immunogens, but maintains the integrity of the extracellular matrix. However, the ultrastructure of the decellularized cornea has yet to be demonstrated in detail. We investigated the influence of high hydrostatic pressure (HHP) on the decellularization of the corneal ultrastructure and its involvement in transparency, and assessed the in vivo behaviour of the decellularized cornea using two animal transplantation models, in relation to remodelling of collagen fibrils. Decellularized corneas were prepared by the HHP method. The decellularized corneas were executed by haematoxylin and eosin and Masson’s trichrome staining to demonstrate the complete removal of corneal cells. Transmission electron microscopy revealed that the ultrastructure of the decellularized cornea prepared by the HHP method was better maintained than that of the decellularized cornea prepared by the detergent method. The decellularized cornea after interlamellar keratoplasty and microkeratome-assisted anterior lamellar keratoplasty using a rabbit model was stable and remained transparent without ultrastructural alterations. We conclude that the superior properties of the decellularized cornea prepared by the HHP method were attributed to the preservation of the corneal ultrastructure. PMID:27291975

  3. Effects of 5-Fluorouracil on Morphology, Cell Cycle, Proliferation, Apoptosis, Autophagy and ROS Production in Endothelial Cells and Cardiomyocytes

    PubMed Central

    Focaccetti, Chiara; Bruno, Antonino; Magnani, Elena; Bartolini, Desirée; Principi, Elisa; Dallaglio, Katiuscia; Bucci, Eraldo O.; Finzi, Giovanna; Sessa, Fausto; Noonan, Douglas M.; Albini, Adriana

    2015-01-01

    Antimetabolites are a class of effective anticancer drugs interfering in essential biochemical processes. 5-Fluorouracil (5-FU) and its prodrug Capecitabine are widely used in the treatment of several solid tumors (gastro-intestinal, gynecological, head and neck, breast carcinomas). Therapy with fluoropyrimidines is associated with a wide range of adverse effects, including diarrhea, dehydration, abdominal pain, nausea, stomatitis, and hand-foot syndrome. Among the 5-FU side effects, increasing attention is given to cardiovascular toxicities induced at different levels and intensities. Since the mechanisms related to 5-FU-induced cardiotoxicity are still unclear, we examined the effects of 5-FU on primary cell cultures of human cardiomyocytes and endothelial cells, which represent two key components of the cardiovascular system. We analyzed at the cellular and molecular level 5-FU effects on cell proliferation, cell cycle, survival and induction of apoptosis, in an experimental cardioncology approach. We observed autophagic features at the ultrastructural and molecular levels, in particular in 5-FU exposed cardiomyocytes. Reactive oxygen species (ROS) elevation characterized the endothelial response. These responses were prevented by a ROS scavenger. We found induction of a senescent phenotype on both cell types treated with 5-FU. In vivo, in a xenograft model of colon cancer, we showed that 5-FU treatment induced ultrastructural changes in the endothelium of various organs. Taken together, our data suggest that 5-FU can affect, both at the cellular and molecular levels, two key cell types of the cardiovascular system, potentially explaining some manifestations of 5-FU-induced cardiovascular toxicity. PMID:25671635

  4. Characterisation of Growth and Ultrastructural Effects of the Xanthoria elegans Photobiont After 1.5 Years of Space Exposure on the International Space Station.

    PubMed

    Brandt, Annette; Posthoff, Eva; de Vera, Jean-Pierre; Onofri, Silvano; Ott, Sieglinde

    2016-06-01

    The lichen Xanthoria elegans has been exposed to space and simulated Mars-analogue environment in the Lichen and Fungi Experiment (LIFE) on the EXPOSE-E facility at the International Space Station (ISS). This long-term exposure of 559 days tested the ability of various organisms to cope with either low earth orbit (LEO) or Mars-analogue conditions, such as vacuum, Mars-analogue atmosphere, rapid temperature cycling, cosmic radiation of up to 215 ± 16 mGy, and insolation of accumulated doses up to 4.87 GJm(-2), including up to 0.314 GJm(-2) of UV irradiation. In a previous study, X. elegans demonstrated considerable resistance towards these conditions by means of photosynthetic activity as well as by post-exposure metabolic activity of 50-80% in the algal and 60-90% in the fungal symbiont (Brandt et al. Int J Astrobiol 14(3):411-425, 2015). The two objectives of the present study were complementary: First, to verify the high post-exposure viability by using a qualitative cultivation assay. Second, to characterise the cellular damages by transmission electron microscopy (TEM) which were caused by the space and Mars-analogue exposure conditions of LIFE. Since the algal symbiont of lichens is considered as the more susceptible partner (de Vera and Ott 2010), the analyses focused on the photobiont. The study demonstrated growth and proliferation of the isolated photobiont after all exposure conditions of LIFE. The ultrastructural analysis of the algal cells provided an insight to cellular damages caused by long-term exposure and highlighted that desiccation-induced breakdown of cellular integrity is more pronounced under the more severe space vacuum than under Mars-analogue atmospheric conditions. In conclusion, desiccation-induced damages were identified as a major threat to the photobiont of X. elegans. Nonetheless, a fraction of the photobiont cells remained cultivable after all exposure conditions tested in LIFE. PMID:26526425

  5. Characterisation of Growth and Ultrastructural Effects of the Xanthoria elegans Photobiont After 1.5 Years of Space Exposure on the International Space Station

    NASA Astrophysics Data System (ADS)

    Brandt, Annette; Posthoff, Eva; de Vera, Jean-Pierre; Onofri, Silvano; Ott, Sieglinde

    2016-06-01

    The lichen Xanthoria elegans has been exposed to space and simulated Mars-analogue environment in the Lichen and Fungi Experiment (LIFE) on the EXPOSE-E facility at the International Space Station (ISS). This long-term exposure of 559 days tested the ability of various organisms to cope with either low earth orbit (LEO) or Mars-analogue conditions, such as vacuum, Mars-analogue atmosphere, rapid temperature cycling, cosmic radiation of up to 215 ± 16 mGy, and insolation of accumulated doses up to 4.87 GJm-2, including up to 0.314 GJm-2 of UV irradiation. In a previous study, X. elegans demonstrated considerable resistance towards these conditions by means of photosynthetic activity as well as by post-exposure metabolic activity of 50-80 % in the algal and 60-90 % in the fungal symbiont (Brandt et al. Int J Astrobiol 14(3):411-425, 2015). The two objectives of the present study were complementary: First, to verify the high post-exposure viability by using a qualitative cultivation assay. Second, to characterise the cellular damages by transmission electron microscopy (TEM) which were caused by the space and Mars-analogue exposure conditions of LIFE. Since the algal symbiont of lichens is considered as the more susceptible partner (de Vera and Ott 2010), the analyses focused on the photobiont. The study demonstrated growth and proliferation of the isolated photobiont after all exposure conditions of LIFE. The ultrastructural analysis of the algal cells provided an insight to cellular damages caused by long-term exposure and highlighted that desiccation-induced breakdown of cellular integrity is more pronounced under the more severe space vacuum than under Mars-analogue atmospheric conditions. In conclusion, desiccation-induced damages were identified as a major threat to the photobiont of X. elegans. Nonetheless, a fraction of the photobiont cells remained cultivable after all exposure conditions tested in LIFE.

  6. Ultrastructural analysis of adult mouse neocortex comparing aldehyde perfusion with cryo fixation

    PubMed Central

    Korogod, Natalya; Petersen, Carl CH; Knott, Graham W

    2015-01-01

    Analysis of brain ultrastructure using electron microscopy typically relies on chemical fixation. However, this is known to cause significant tissue distortion including a reduction in the extracellular space. Cryo fixation is thought to give a truer representation of biological structures, and here we use rapid, high-pressure freezing on adult mouse neocortex to quantify the extent to which these two fixation methods differ in terms of their preservation of the different cellular compartments, and the arrangement of membranes at the synapse and around blood vessels. As well as preserving a physiological extracellular space, cryo fixation reveals larger numbers of docked synaptic vesicles, a smaller glial volume, and a less intimate glial coverage of synapses and blood vessels compared to chemical fixation. The ultrastructure of mouse neocortex therefore differs significantly comparing cryo and chemical fixation conditions. DOI: http://dx.doi.org/10.7554/eLife.05793.001 PMID:26259873

  7. Ultrastructural Imaging of Endocytic Sites in Saccharomyces cerevisiae by Transmission Electron Microscopy and Immunolabeling

    PubMed Central

    Buser, Christopher; Drubin, David G.

    2014-01-01

    Defining the ultrastructure of endocytic sites and localization of endocytic proteins in Saccharomyces cerevisiae by immunoelectron microscopy is central in understanding the mechanisms of membrane deformation and scission during endocytosis. We show that an improved sample preparation protocol based on high-pressure freezing, freeze substitution, and low-temperature embedding allows us to maintain the cellular fine structure and to immunolabel green fluorescent protein–tagged endocytic proteins or actin in the same sections. Using this technique we analyzed the stepwise deformation of endocytic membranes and immuno-localized the endocytic proteins Abp1p, Sla1p, Rvs167p, and actin, and were able to draw a clear ultrastructural distinction between endocytic sites and eisosomes by immunolocalizing Pil1p. In addition to defining the geometry and the fine structure of budding yeast endocytic sites, we observed associated actin filaments forming a cage-like meshwork around the endocytic membrane. PMID:23458500

  8. Ultrastructural analysis of adult mouse neocortex comparing aldehyde perfusion with cryo fixation.

    PubMed

    Korogod, Natalya; Petersen, Carl C H; Knott, Graham W

    2015-01-01

    Analysis of brain ultrastructure using electron microscopy typically relies on chemical fixation. However, this is known to cause significant tissue distortion including a reduction in the extracellular space. Cryo fixation is thought to give a truer representation of biological structures, and here we use rapid, high-pressure freezing on adult mouse neocortex to quantify the extent to which these two fixation methods differ in terms of their preservation of the different cellular compartments, and the arrangement of membranes at the synapse and around blood vessels. As well as preserving a physiological extracellular space, cryo fixation reveals larger numbers of docked synaptic vesicles, a smaller glial volume, and a less intimate glial coverage of synapses and blood vessels compared to chemical fixation. The ultrastructure of mouse neocortex therefore differs significantly comparing cryo and chemical fixation conditions. PMID:26259873

  9. Apoptotic human neutrophil peptide-1 anti-tumor activity revealed by cellular biomechanics.

    PubMed

    Gaspar, Diana; Freire, João M; Pacheco, Teresa R; Barata, João T; Castanho, Miguel A R B

    2015-02-01

    Cancer remains a major cause of morbidity and mortality worldwide. Although progress has been made regarding chemotherapeutic agents, new therapies that combine increased selectivity and efficacy with low resistance are still needed. In the search for new anticancer agents, therapies based on biologically active peptides, in particular, antimicrobial peptides (AMPs), have attracted attention for their decreased resistance development and low cytotoxicity. Many AMPs have proved to be tumoricidal agents against human cancer cells, but their mode of action is still controversial. The existence of common properties shared by the membranes of bacteria and tumor cells points to similar lipid-targeting mechanisms in both cases. On the other hand, anticancer peptides (ACPs) also induce apoptosis and inhibit angiogenesis. Human neutrophil peptide-1 (HNP-1) is an endogenous AMP that has been implicated in different cellular phenomena such as tumor proliferation. The presence of HNP-1 in the serum/plasma of oncologic patients turns this peptide into a potential tumor biomarker. The present work reveals the different effects of HNP-1 on the biophysical and nanomechanical properties of solid and hematological tumor cells. Studies on cellular morphology, cellular stiffness, and membrane ultrastructure and charge using atomic force microscopy (AFM) and zeta potential measurements show a preferential binding of HNP-1 to solid tumor cells from human prostate adenocarcinoma when compared to human leukemia cells. AFM also reveals induction of apoptosis with cellular membrane defects at very low peptide concentrations. Understanding ACPs mode(s) of action will certainly open innovative pathways for drug development in cancer treatment. PMID:25447543

  10. Effects of camptothecin derivatives and topoisomerase dual inhibitors on Trypanosoma cruzi growth and ultrastructure

    PubMed Central

    2014-01-01

    Background Trypanosoma cruzi is the etiological agent of Chagas’ disease that is an endemic disease in Latin America and affects about 8 million people. This parasite belongs to the Trypanosomatidae family which contains a single mitochondrion with an enlarged region, named kinetoplast that harbors the mitochondrial DNA (kDNA). The kinetoplast and the nucleus present a great variety of essential enzymes involved in DNA replication and topology, including DNA topoisomerases. Such enzymes are considered to be promising molecular targets for cancer treatment and for antiparasitic chemotherapy. In this work, the proliferation and ultrastructure of T. cruzi epimastigotes were evaluated after treatment with eukaryotic topoisomerase I inhibitors, such as topotecan and irinotecan, as well as with dual inhibitors (compounds that block eukaryotic topoisomerase I and topoisomerase II activities), such as baicalein, luteolin and evodiamine. Previous studies have shown that such inhibitors were able to block the growth of tumor cells, however most of them have never been tested on trypanosomatids. Results Considering the effects of topoisomerase I inhibitors, our results showed that topotecan decreased cell proliferation and caused unpacking of nuclear heterochromatin, however none of these alterations were observed after treatment with irinotecan. The dual inhibitors baicalein and evodiamine decreased cell growth; however the nuclear and kinetoplast ultrastructures were not affected. Conclusions Taken together, our data showed that camptothecin is more efficient than its derivatives in decreasing T. cruzi proliferation. Furthermore, we conclude that drugs pertaining to a certain class of topoisomerase inhibitors may present different efficiencies as chemotherapeutical agents. PMID:24917086

  11. Calcium signaling and cell proliferation.

    PubMed

    Pinto, Mauro Cunha Xavier; Kihara, Alexandre Hiroaki; Goulart, Vânia A M; Tonelli, Fernanda M P; Gomes, Katia N; Ulrich, Henning; Resende, Rodrigo R

    2015-11-01

    Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review. PMID:26275497

  12. Ultrastructural damage of Trypanosoma cruzi epimastigotes exposed to decomplemented immune sera.

    PubMed

    Fernández-Presas, A M; Zavala, J T; Fauser, I B; Merchant, M T; Guerrero, L R; Willms, K

    2001-08-01

    The susceptibility of Trypanosoma cruzi epimastigotes to lysis by normal or immune sera in a complement-dependent reaction has been reported, but the effects induced directly by immune serum depleted of complement remain unstudied. The aim of this work was to study the ultrastructural alterations induced in T. cruzi epimastigotes by immune mouse or rabbit sera with or without complement. A local isolate of T. cruzi (Queretaro) was used in all experiments. Immune sera were raised in both mouse and rabbit by immunization with T. cruzi epimastigote antigens. Light microscopy showed intense agglutination of epimastigotes when incubated with decomplemented mouse or rabbit immune sera. A distinctive ultrastructural feature of this agglutination pattern was the fusion of plasma membranes and a pattern of intercrossing between subpellicular microtubules. Agglutination was associated with fragmentation of nuclear membranes and swelling of cytoplasm, Golgi cisternae, endoplasmic reticulum, mitochondria and kinetoplast membranes. Agglutinated parasites also incorporated trypan blue stain. Results of [3H]-thymidine incorporation confirmed that epimastigotes exposed to specific antibodies in the absence of complement were incapable of proliferating. Ultrastructural changes observed in epimastigote micrographs incubated with decomplemented immune mouse sera were statistically significant (P<0.001) when compared with results obtained from images after incubation with decomplemented normal mouse sera. PMID:11510997

  13. The Effect of Spaceflight on the Ultrastructure of the Cerebellum

    NASA Technical Reports Server (NTRS)

    Holstein, Gay R.; Martinelli, Giorgio P.

    2003-01-01

    In weightlessness, astronauts and cosmonauts may experience postural illusions as well as motion sickness symptoms known as the space adaptation syndrome. Upon return to Earth, they have irregularities in posture and balance. The adaptation to microgravity and subsequent re-adaptation to Earth occurs over several days. At the cellular level, a process called neuronal plasticity may mediate this adaptation. The term plasticity refers to the flexibility and modifiability in the architecture and functions of the nervous system. In fact, plastic changes are thought to underlie not just behavioral adaptation, but also the more generalized phenomena of learning and memory. The goal of this experiment was to identify some of the structural alterations that occur in the rat brain during the sensory and motor adaptation to microgravity. One brain region where plasticity has been studied extensively is the cerebellar cortex-a structure thought to be critical for motor control, coordination, the timing of movements, and, most relevant to the present experiment, motor learning. Also, there are direct as well as indirect connections between projections from the gravity-sensing otolith organs and several subregions of the cerebellum. We tested the hypothesis that alterations in the ultrastructural (the structure within the cell) architecture of rat cerebellar cortex occur during the early period of adaptation to microgravity, as the cerebellum adapts to the absence of the usual gravitational inputs. The results show ultrastructural evidence for neuronal plasticity in the central nervous system of adult rats after 24 hours of spaceflight. Qualitative studies conducted on tissue from the cerebellar cortex (specifically, the nodulus of the cerebellum) indicate that ultrastructural signs of plasticity are present in the cerebellar zones that receive input from the gravity-sensing organs in the inner ear (the otoliths). These changes are not observed in this region in cagematched

  14. Pulsed electromagnetic wave exposure induces ultrastructural damage and upregulated expression of heat shock protein 70 in the rat adenohypophysis.

    PubMed

    Cheng, Kang; Ren, Dong-Qing; Yi, Jun; Zhou, Xiao-Guang; Yang, Wen-Qing; Chen, Yong-Bin; Li, Yong-Qiang; Huang, Xiao-Feng; Zeng, Gui-Ying

    2015-08-01

    The aim of the present study was to investigate the ultrastructural damage and the expression of heat shock protein 70 (HSP70) in the rat adenohypophysis following pulsed electromagnetic wave (PEMW) exposure. The rats were randomly divided into four groups: Sham PEMW exposure, 1 x 10(4) pulses of PEMW exposure, 1 x 10(5) pulses of PEMW exposure and 3 x 10(5) pulses of PEMW exposure. Whole body radiation of 1 x 10(4) pulses, 1 x 10(5) pulses and 3 x 10(5) pulses of PEMW were delivered with a field strength of 100 kV/m. The rats in each group (n=6 in each) were sacrificed 12, 24, 48 and 96 h after PEMW exposure. Transmission electron microscopy was then used to detect the ultrastructural changes and immunocytochemistry was used to examine the expression of HSP70. Cellular damage, including mitochondrial vacuolation occurred as early as 12 h after PEMW exposure.More severe cellular damages, including cell degeneration and necrosis, occurred 24 and 48 h after PEMW exposure. The PEMW-induced cellular damage increased as the number of PEMW pulses increased. In addition, the expression of HSP70 significantly increased following PEMW exposure and peaked after 12 h. These findings suggested that PEMW induced ultrastructural damages in the rat adenohypophysis and that HSP70 may have contributed to the PEMW-induced adenohypophyseal damage. PMID:25891763

  15. Changes in cell wall ultrastructure induced by sudden flooding at 25{degrees}C in Pisum sativum (Fabaceae) primary roots.

    PubMed

    Sarkar, Purbasha; Niki, Teruo; Gladish, Daniel K

    2008-07-01

    Cellular degeneration is essential for many developmental and stress acclimation processes. Undifferentiated parenchymatous cells in the central vascular cylinder of pea primary roots degenerate under hypoxic conditions created by flooding at temperatures >15°C, forming a long vascular cavity that seems to provide a conduit for longitudinal oxygen transport in the roots. We show that specific changes in the cell wall ultrastructure accompanied previously detected cytoplasmic and organellar degradation in the cavity-forming roots. The degenerating cells had thinner primary cell walls, less electron-dense middle lamellae, and less abundant cell wall homogalacturonans in altered patterns, compared to healthy cells of roots grown under cold, nonflooded conditions. Cellular breakdown and changes in wall ultrastructure, however, remained confined to cells within a 50-μm radius around the root center, even after full development of the cavity. Cells farther away maintained cellular integrity and had signs of wall synthesis, perhaps from tight regulation of wall metabolism over short distances. These observations suggest that the cell degeneration might involve programmed cell death. We also show that warm, nonflooded or cold, flooded conditions that typically do not induce vascular cavity formation can also induce variations in cell wall ultrastructure. PMID:21632404

  16. Ultrastructural Analysis of Leishmania infantum chagasi Promastigotes Forms Treated In Vitro with Usnic Acid

    PubMed Central

    da Luz, João S. B.; de Oliveira, Erwelly B.; Martins, Monica C. B.; da Silva, Nicácio H.; Alves, Luiz C.; dos Santos, Fábio A. B.; da Silva, Luiz L. S.; Silva, Eliete C.; de Medeiros, Paloma L.

    2015-01-01

    Leishmaniasis is considered by the World Health Organization as one of the infectious parasitic diseases endemic of great relevance and a global public health problem. Pentavalent antimonials used for treatment of this disease are limited and new phytochemicals emerge as an alternative to existing treatments, due to the low toxicity and cost reduction. Usnic acid is uniquely found in lichens and is especially abundant in genera such as Alectoria, Cladonia, Evernia, Lecanora, Ramalina, and Usnea. Usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory, and analgesic activity. The aim of this study was to evaluate the antileishmanial activity of usnic acid on Leishmania infantum chagasi promastigotes and the occurrence of drug-induced ultrastructural damage in the parasite. Usnic acid was effective against the promastigote forms (IC50 = 18.30 ± 2.00 µg/mL). Structural and ultrastructural aspects of parasite were analyzed. Morphological alterations were observed as blebs in cell membrane and shapes given off, increasing the number of cytoplasmic vacuoles, and cellular and mitochondrial swelling, with loss of cell polarity. We concluded that the usnic acid presented antileishmanial activity against promastigote forms of Leishmania infantum chagasi and structural and ultrastructural analysis reinforces its cytotoxicity. Further, in vitro studies are warranted to further evaluate this potential. PMID:25767824

  17. Ultrastructural study of mouse adipose-derived stromal cells induced towards osteogenic direction.

    PubMed

    Tsupykov, Oleg; Ustymenko, Alina; Kyryk, Vitaliy; Smozhanik, Ekaterina; Yatsenko, Kateryna; Butenko, Gennadii; Skibo, Galina

    2016-06-01

    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. PMID:27087359

  18. Ultrastructure of spermatogenesis, spermatozoon and processes of testicular regression and recrudescence in Eptesicus furinalis (Chiroptera: Vespertilionidae).

    PubMed

    Bueno, Larissa M; Beguelini, Mateus R; Comelis, Manuela T; Taboga, Sebastião R; Morielle-Versute, Eliana

    2014-08-01

    Studies have shown that the annual reproductive cycle of Eptesicus furinalis includes at least one period of total testicular regression. Thus, this study aimed to evaluate their reproductive cycle ultrastructurally. The annual reproductive cycle was divided into four periods: active, regressing, regressed and recrudescence. The active period was similar to that of other bats, including the completion of spermatogenesis with three main types of spermatogonia (Ad, Ap and B) and 12 steps in the process of spermatid differentiation. However, its spermatozoa differed in that outer dense fibers 1, 5, 6 and 9 are larger than the others and due to the presence of what is likely a probably genera-specific bulging in the anterior portion. In the regressing period, Sertoli cell nuclei migrate to the basal compartment with the nuclei close to the basal lamina. The basal compartment had a more compact appearance than the adluminal compartment, with relaxed cellular connections. In the regressed period, spermatogenesis ceased; the seminiferous epithelium was composed only of Sertoli cells and three types of spermatogonia: types Ad, 1 and 2. In the recrudescence period, spermatogenesis restarted, with the process of reactivation divided into three phases: early, medial and late recrudescence. In conclusion, our study described the process of spermatogenesis and the ultrastructure of the spermatozoa and confirmed the presence of a process of total testicular regression in the annual cycle of E. furinalis. We characterize distinct morphologic variations in the ultrastructure of the testicular cells during the four different periods of the annual reproductive cycle. PMID:24954586

  19. Ultrastructure of gingival epithelium in chronic gingivitis.

    PubMed

    Lushnikova, E L; Nepomnyashchikh, L M; Oskolsky, G I; Jurkevich, N V

    2012-03-01

    We studied ultrastructural reorganization of the gingival mucosa in chronic gingivitis. It was found that chronic inflammation leads to significant intracellular reorganization of epitheliocytes in the basal and prickle cell layers of gingival epithelium and their pronounced structural and functional heterogeneity. The main ultrastructural alterations of epitheliocytes in the basal and prickle cell layers include pronounced vacuolization of the perinuclear zone (partial necrosis), formation of thick tonofilament bundles, focal lysis and sequestration of glycogen, and destruction and reduction of intracellular junctions in some cases accompanied by acantholytic alterations. Chronic inflammation in the gingival mucosa induced extensive remodeling of the lamina propria manifested in multiplication of the basement membrane and obturation of blood vessels with collagen fibrils. PMID:22803154

  20. Dermal ultrastructure in collagen VI myopathy.

    PubMed

    Hermanns-Lê, Trinh; Piérard, Gérald E; Piérard-Franchimont, Claudine; Delvenne, Philippe

    2014-04-01

    The COL VI mutations are responsible for a spectrum of myopathies. The authors report cutaneous ultrastructural alterations in a patient with COL6A2 myopathy. The changes include variations in size of collagen fibrils, flower-like sections of collagen fibrils, as well as thickening of vessel and nerve basement membranes. Electron microscopy of a skin biopsy contributes to the diagnosis of COL VI myopathies. PMID:24134684

  1. TAp73 promotes anti-senescence-anabolism not proliferation

    PubMed Central

    Agostini, Massimiliano; Niklison-Chirou, Maria Victoria; Catani, Maria Valeria; Knight, Richard A.; Melino, Gerry; Rufini, Alessandro

    2014-01-01

    TAp73, a member of the p53 family, has been traditionally considered a tumor suppressor gene, but a recent report has claimed that it can promote cellular proliferation. This assumption is based on biochemical evidence of activation of anabolic metabolism, with enhanced pentose phosphate shunt (PPP) and nucleotide biosynthesis. Here, while we confirm that TAp73 expression enhances anabolism, we also substantiate its role in inhibiting proliferation and promoting cell death. Hence, we would like to propose an alternative interpretation of the accumulating data linking p73 to cellular metabolism: we suggest that TAp73 promotes anabolism to counteract cellular senescence rather than to support proliferation. PMID:25554796

  2. Ultrastructural studies on dengue virus infection of human lymphoblasts.

    PubMed Central

    Sriurairatna, S; Bhamarapravati, N; Diwan, A R; Halstead, S B

    1978-01-01

    Ultrastructural studies of dengue-2 virus-infected lymphoblastoid Raji cells showed that the virus induced an increase in the size of the rough endoplasmic reticula (RER) and that the replication of the virus was confined to the cisternae of these RER. The proliferating RER formed cytoplasmic inclusions that could be seen by light microscopy. This observation could be used as evidence of a cytopathogenic effect of dengue virus on infected Rajii cells in routine cultures. Accumulation of virions in the infected cells was minimal in comparison with other cell systems, however. Sporadic clusters of mature virions were often seen on the plasma membrane. These extracellular virions were distributed adjacent to the virus-bearing RER and were presumably released virions. Vertical transmission of the virus was evident in mitotic lymphoblasts. The replication pattern of dengue virus in lymphoblastoid cells suggests that efforts should be made to determine whether blast-transformed lymphocytes, numerous in secondary dengue infections, support dengue virus replication in vivo. Images PMID:669791

  3. Dexamethasone induced ultrastructural changes in cultured human trabecular meshwork cells.

    PubMed

    Wilson, K; McCartney, M D; Miggans, S T; Clark, A F

    1993-09-01

    Glucocorticoid-induced ocular hypertension has been demonstrated in both animals and humans. It is possible that glucocorticoid-induced changes in trabecular meshwork (TM) cells are responsible for this hypertension. In order to elaborate further the effect of glucocorticoids on the trabecular meshwork, the ultrastructural consequences of dexamethasone (DEX) treatment were examined in three different human TM cell lines. Confluent TM cells were treated with 0.1 microM of DEX for 14 days, and then processed for light, epifluorescent microscopy or transmission electron microscopy (TEM). The effect of DEX treatment on TM cell and nuclear size was quantified using computer assisted morphometrics. Morphometric analysis showed a significant increase in both TM cell and nuclear size after 14 days of DEX treatment. Epifluorescent microscopy of rhodamine-phalloidin stained, control TM cells showed the normal arrangement of stress fibers. In contrast, DEX-treated TM cells showed unusual geodesic dome-like cross-linked actin networks. Control TM cells had the normal complement and arrangement of organelles as well as electron dense inclusions and large vacuoles. DEX-treated TM cells showed stacked arrangements of smooth and rough endoplasmic reticulum, proliferation of the Golgi apparatus, pleomorphic nuclei and increased amounts of extracellular matrix material. The DEX-induced alterations observed in the present study may be an indication of the processes that are occurring in the in vivo disease process. PMID:8261790

  4. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence

    PubMed Central

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data. PMID:26805432

  5. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence.

    PubMed

    Bernadotte, Alexandra; Mikhelson, Victor M; Spivak, Irina M

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data. PMID:26805432

  6. Sinusoidal ultrastructure evaluated during the revascularization of regenerating rat liver.

    PubMed

    Wack, K E; Ross, M A; Zegarra, V; Sysko, L R; Watkins, S C; Stolz, D B

    2001-02-01

    Sinusoidal endothelial cell (SEC) porosities were compared between the periportal (zone 1) and pericentral (zone 3) regions of the rat liver during regeneration following partial hepatectomy (PHx). SEC porosities and fenestration diameters were measured in control livers, as well as at 5 minutes, 24, 48, 72, 96, 120 hours, and 14 days following PHx. Bimodal maximums in both porosity and fenestration diameters were observed in both zones at 5 minutes and 5 days following PHx. SEC porosities increased significantly in both zones 1 and 3 within 5 minutes following PHx, but the increase was maintained only in zone 1 at 24 hours after resection. Following the initial rise, both zones displayed a gradual decrease to less than half their porosity values at 72 hr post-PHx. After 72 hours, porosities increased to over control levels and remained elevated until 14 days after PHx. The decrease in porosity at 72 hr post-PHx is accompanied by ultrastructural changes within the sinusoid at this time. Vascular corrosion casting and transmission electron microscopy (TEM) show sinusoid compression resulting from increased hepatic plate widths due to hepatocyte proliferation in the absence of SEC proliferation. Also at this time, we observed many SEC completely enveloped by stellate cells. The zonal variations observed for porosities throughout regeneration did not correlate with changes in laminin, collagen I and IV, or fibronectin deposition within the space of Disse. Taken together, the data reveal that SEC are dynamic regulators of porosity that respond rapidly and locally to environmental zonal stimuli during liver regeneration. PMID:11172338

  7. Cellular resilience.

    PubMed

    Smirnova, Lena; Harris, Georgina; Leist, Marcel; Hartung, Thomas

    2015-01-01

    Cellular resilience describes the ability of a cell to cope with environmental changes such as toxicant exposure. If cellular metabolism does not collapse directly after the hit or end in programmed cell death, the ensuing stress responses promote a new homeostasis under stress. The processes of reverting "back to normal" and reversal of apoptosis ("anastasis") have been studied little at the cellular level. Cell types show astonishingly similar vulnerability to most toxicants, except for those that require a very specific target, metabolism or mechanism present only in specific cell types. The majority of chemicals triggers "general cytotoxicity" in any cell at similar concentrations. We hypothesize that cells differ less in their vulnerability to a given toxicant than in their resilience (coping with the "hit"). In many cases, cells do not return to the naive state after a toxic insult. The phenomena of "pre-conditioning", "tolerance" and "hormesis" describe this for low-dose exposures to toxicants that render the cell more resistant to subsequent hits. The defense and resilience programs include epigenetic changes that leave a "memory/scar" - an alteration as a consequence of the stress the cell has experienced. These memories might have long-term consequences, both positive (resistance) and negative, that contribute to chronic and delayed manifestations of hazard and, ultimately, disease. This article calls for more systematic analyses of how cells cope with toxic perturbations in the long-term after stressor withdrawal. A technical prerequisite for these are stable (organotypic) cultures and a characterization of stress response molecular networks. PMID:26536287

  8. Ultrastructural findings in lymph nodes from pigs suffering from naturally occurring postweaning multisystemic wasting syndrome.

    PubMed

    Rodriguez-Cariño, C; Segalés, J

    2009-07-01

    The aims of this study were to evaluate ultrastructural lesions in lymph nodes from postweaning multisystemic wasting syndrome (PMWS)-affected pigs and to correlate these alterations with detection of viral-like particles (VLPs). Samples of lymph nodes were taken from 4 PMWS-affected pigs and 2 healthy animals and processed by transmission electron microscopy. Significant ultrastructural alterations were only noted in PMWS-affected pigs, mainly in histiocytes and rarely in other cell types. Histiocytes showed severe swelling and proliferation of mitochondria, and proliferation and dilation of rough endoplasmic reticulum and Golgi complex. Infected histiocytes contained large numbers of intracytoplasmic inclusion (ICI) bodies with VLPs; some histiocytes also had intranuclear inclusions (INIs). Small inclusions were surrounded by double membrane, with a granular appearance or containing paracrystalline arrays; icosahedral VLPs were 8-17 nm in diameter. Large ICIs were double-membrane bounded or not and contained VLPs usually forming paracrystalline arrays. ICIs were often found next to mitochondria with severe swelling, and also inside them. INIs were not surrounded by membranes and contained virions of 10-13 nm diameter. Lymphocyte depletion was a striking finding of lymph nodes from PMWS-affected pigs. The inclusion bodies containing VLPs referred to in the present study should be classified as viral factories, suggesting that viral replication is probably a frequent event in macrophages, in which mitochondria might play a role. PMID:19276043

  9. Three-Dimensional Reconstruction, by TEM Tomography, of the Ultrastructural Modifications Occurring in Cucumis sativus L. Mitochondria under Fe Deficiency

    PubMed Central

    Vigani, Gianpiero; Faoro, Franco; Ferretti, Anna Maria; Cantele, Francesca; Maffi, Dario; Marelli, Marcello; Maver, Mauro; Murgia, Irene; Zocchi, Graziano

    2015-01-01

    Background Mitochondria, as recently suggested, might be involved in iron sensing and signalling pathways in plant cells. For a better understanding of the role of these organelles in mediating the Fe deficiency responses in plant cells, it is crucial to provide a full overview of their modifications occurring under Fe-limited conditions. The aim of this work is to characterize the ultrastructural as well as the biochemical changes occurring in leaf mitochondria of cucumber (Cucumis sativus L.) plants grown under Fe deficiency. Methodology/Results Mitochondrial ultrastructure was investigated by transmission electron microscopy (TEM) and electron tomography techniques, which allowed a three-dimensional (3D) reconstruction of cellular structures. These analyses reveal that mitochondria isolated from cucumber leaves appear in the cristae junction model conformation and that Fe deficiency strongly alters both the number and the volume of cristae. The ultrastructural changes observed in mitochondria isolated from Fe-deficient leaves reflect a metabolic status characterized by a respiratory chain operating at a lower rate (orthodox-like conformation) with respect to mitochondria from control leaves. Conclusions To our knowledge, this is the first report showing a 3D reconstruction of plant mitochondria. Furthermore, these results suggest that a detailed characterization of the link between changes in the ultrastructure and functionality of mitochondria during different nutritional conditions, can provide a successful approach to understand the role of these organelles in the plant response to Fe deficiency. PMID:26107946

  10. Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development.

    PubMed

    Perri, A F; Dallard, B E; Baravalle, C; Licoff, N; Formía, N; Ortega, H H; Becú-Villalobos, D; Mejia, M E; Lacau-Mengido, I M

    2014-01-01

    Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland. PMID:24931533

  11. Ultrastructure of Mycobacterium marinum granuloma in striped bass Morone saxatilis

    USGS Publications Warehouse

    Gauthier, David T.; Vogelbein, W.K.; Ottinger, C.A.

    2004-01-01

    An emerging epizootic of mycobacteriosis currently threatens striped bass Morone saxatilis populations in Chesapeake Bay, USA. Several species of mycobacteria, including Mycobacterium marinum, species resembling M. avium, M. gordonae, M. peregrinum, M. scrofulaceum and M. terrae, and the new species M. shottsii have been isolated from diseased and healthy bass. In this study, we describe the ultrastructure of developing M. marinum granulomas in experimentally infected bass over a period of 45 wk. The primary host response to injected mycobacteria was formation of large macrophage aggregations containing phagocytosed bacilli, M. marinum were always contained within phagosomes. Close association of lysosomes with mycobacterial phagosomes, as well as the presence of electron-opaque material within phagosomes, suggested phagolysosomal fusion. Development of granulomas involved epithelioid transformation of macrophages, followed by appearance of central necrosis. Desmosomes were present between mature epithelioid cells. The necrotic core region of M. marinum granulomas was separated from overlying epithelioid cells by several layers of flattened, electron-opaque spindle-shaped cells. These cells appeared to be formed by compression of epithelioid cells and, aside from a flattened nucleus, did not possess recognizable organelles. Following the development of well-defined, paucibacillary granulomas, secondary disease was observed. Recrudescence was marked by bacterial replication followed by disruption of granuloma architecture, including loss of epithelioid and spindle cell layers. In advanced recrudescent lesions, normal tissue was replaced by macrophages, fibroblasts, and other inflammatory leukocytes. Large numbers of mycobacteria were observed, both intracellular and suspended in cellular debris.

  12. Photodynamic therapy on the ultrastructure of glioma cell

    NASA Astrophysics Data System (ADS)

    Hu, Shaoshan; Zhang, Ruyou; Zheng, Yongri

    2005-07-01

    OBJECTIVE :the main purpose of this experiment was to study the change of C6 glioma cells' ultrastructure treated by photodynamic therapy(PDT), observe the change of morphology METHOD :Make the model of rat glioma by transplanted C6 glioma cells into caudate nucleus,treated the glioma rat by PDT after two weeks. Observed the difference of subcellular structure before and after PDT by electron microscope. RESULT : Apoptosis and necrosis can be seen after treated by PDT in the C6 glioma, basal membrance damaged ,number of cellular organ of endothelial cell of blood capillary declined,tight junction of endothelial cell lengthen and the gap enlarge. The PDT has slightly effect on the nomorl rat"s subcellular structue. CONCLUSION: PDT can induce the apoptosis and necrosis of C6 glioma cell. The damage of the ultramicrostructure of mitochondria and endoplasmic reticulum was the foundmentol of the change. PDT initiate the damage of BBB of the C6 glioma cell and weeken the function、and makes it a useful way of treating the glioma combained with chemotherapy.

  13. Tridimensional ultrastructure and glycolipid pattern studies of Trypanosoma dionisii.

    PubMed

    Oliveira, Miriam Pires de Castro; Ramos, Thiago Cesar Prata; Pinheiro, Adriana Maria V N; Bertini, Silvio; Takahashi, Helio Kiyoshi; Straus, Anita Hilda; Haapalainen, Edna Freymuller

    2013-12-01

    Trypanosoma (Schizotrypanum) dionisii is a non-pathogenic bat trypanosome closely related to Trypanosoma cruzi, the etiological agent of Chaga's disease. Both kinetoplastids present similar morphological stages and are able to infect mammalian cells in culture. In the present study we examined 3D ultrastructure aspects of the two species by serial sectioning epimastigote and trypomastigote forms, and identified common carbohydrate epitopes expressed in T. dionisii, T. cruzi and Leishmania major. A major difference in 3D morphology was that T. dionisii epimastigote forms present larger multivesicular structures, restricted to the parasite posterior region. These structures could be related to T. cruzi reservosomes and are also rich in cruzipain, the major cysteine-proteinase of T. cruzi. We analyzed the reactivity of two monoclonal antibodies: MEST-1 directed to galactofuranose residues of glycolipids purified from Paracoccidioides brasiliensis, and BST-1 directed to glycolipids purified from T. cruzi epimastigotes. Both antibodies were reactive with T. dionisii epimastigotes by indirect immunofluorescense, but we noted differences in the location and intensity of the epitopes, when compared to T. cruzi. In summary, despite similar features in cellular structure and life cycle of T. dionisii and T. cruzi, we observed a unique morphological characteristic in T. dionisii that deserves to be explored. PMID:23933185

  14. Ultrastructure of the adipose tissue matrix in children with malnutrition.

    PubMed

    Alexa, A; Drăgan, M; Popa, I; Raica, M; Dema, E

    1995-01-01

    Bioptic fragments of adipose white tissue taken from trochanterian area from children of 2-22 months old were ultrastructurally investigated. Children were of both sexes, 5 normal and 22 with clinical diagnosis of malnutrition. There were studied many interadipocyte spaces signalling out in cases with malnutrition modifications of different components, some of them related with the degree of malnutrition. There were noted: disorganisation and disappearance of basal membranes of capillaries and glycolema; modifications of endothelial cells with lesions of the capillary wall and free degraded red blood cells; disorganization of the ground substance in small areas or sometimes extended to all matrix of the space; collagen fibres reduced in number and size, and in two cases the presence of collagen fibrils with severe lesions, realeasing an electrondense material, fibrinoid-like; matrix infiltration, in some cases with lipids. In only one interadipocyte space a synaptic button was noted in contact with capillary. In malnutrition lesions of cellular elements of the white adipose tissue the following were observed: adipocytes, fibroblasts, fibrocytes, endothelial cells, mast cells--which in their turn are responsible for modifications of macromolecular structures of the extracellular matrix--glycosaminoglycans, proteoglycans, components of which biosyntheses are cell-dependent. PMID:8772367

  15. Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids.

    PubMed

    Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

    2015-11-01

    Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern

  16. Morphologic, molecular, and ultrastructural characterization of a feline synovial cell sarcoma and derived cell line.

    PubMed

    Cazzini, Paola; Frontera-Acevedo, Karelma; Garner, Bridget; Howerth, Elizabeth; Torres, Bryan; Northrup, Nicole; Sakamoto, Kaori

    2015-05-01

    A 2.5-year-old, male, neutered cat presented with a 5-month history of progressive right hind limb lameness and an enlarged right popliteal lymph node. Radiographs revealed significant bony lysis of the tarsus and distal tibia, and fine-needle aspirate of the bone lesion and lymph node revealed a neoplastic population of cells with uncertain origin. Amputation was elected, and the mass was submitted for histology and cellular culture for better characterization. Histologic examination revealed a mixture of spindle-shaped cells and larger, round to polygonal cells. All cells were immunoreactive for vimentin, and only the larger polygonal cells were also positive for cytokeratin. All cells were negative for desmin, smooth muscle actin, cluster of differentiation (CD)3, CD18, CD79a, macrophage antibody (MAC)387, and glial fibrillary acidic protein. Cultured neoplastic cells failed to express CD18, and were not able to secrete the pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1 (IL-1)β, and IL-6 when stimulated by lipopolysaccharide, disproving that the cells originated from the macrophage or monocyte line. Ultrastructurally, neoplastic cells were characterized by abundant rough endoplasmic reticulum, interdigitating cellular processes, and membrane condensations. Based on location and cytologic, histologic, ultrastructural, and functional studies, this neoplasm was considered a synovial cell sarcoma. PMID:25901004

  17. The ultrastructure and genetic traits of plants under the condition of hypobaric and hypoxia

    NASA Astrophysics Data System (ADS)

    Guo, Shuangsheng; Tang, Yongkang; Wang, Shulei; Cheng, Quanyong; Zhao, Qi

    This study analyzed the cellular, sub-cellular and molecular levels, particle composition and volume changes of Indian lettuce under the conditions of hypobaric and hypoxia. Firstly, in the hypobaric and hypoxia conditions, two kinds of sample showed a decrease in the num-ber of cells, the increase in volume and the deflation in nuclear size. Secondly, Significant changes of the chloroplast ultrastructure have taken place in the two conditions. Thirdly, in the hypoxia condition, the chloroplast grana lamellae fractured and aggregated, which caused the chloroplasts to enlarge, their lamellae to reduce,become vaguer and finally to disintegrate. Fourthly, the volume change and aggregation of the chloroplasts induced mitochondria to ap-proach the chloroplasts. Fifthly, cytoskeleton immunofluorescence positioning results showed that the microtubules had decreased in number, shortened in length and gathered in the vicinity of the nucleus. In addition, total leaf DNA-sequence alignment found no rbcl gene mutation in the extreme conditions. Keywords: Chloroplast Ultrastructure Cytoskeleton rbcl gene Indian lettuce

  18. Structure and ultrastructure of microvessels in the kidney seen by the corrosion casting method.

    PubMed

    Sangiorgi, Simone; Manelli, Alessandro; Protasoni, Marina; Reguzzoni, Marcella; Congiu, Terenzio; Raspanti, Mario

    2004-01-01

    Scanning electron microscopic observation of corrosion casts is the finest technique to describe spatial patterns of microvessels in many organs, giving a readily interpreted representation of their vascular architecture without interference from surrounding tissues. We focused on the renal cortex of guinea pigs to make an in-depth morphological analysis of structural and ultrastructural details left by the cells on the resin cast. In addition, we made a qualitative description of normal variants usually observed in glomerular disposition, arteriolar morphology or capillary arrangement in the space to shed more light on the relationship between vascular tissue and surrounding cells. The study also disclosed some examples of vascular adaption to physiological and pathological conditions occurring in renal microvessels such as many systems essential to flow regulation, filtration and excretory processes. At lower magnification, all major vessels can be readily distinguished: interlobar, arciform and interlobular arteries and veins, along with a web of peritubular and capsular capillaries. At higher magnification, the glomeruli become visible and the afferent and efferent arteries and the tortuosity the inner vessels can be distinguished. In some of them, the resin, due to the narrowing sizes, suddenly stopped leaving a half-casted glomerulus. This helped to reveal its internal circulation characterized by thin capillaries with a high degree of bi or trifurcation. In addition, we confirmed the close correspondence between cellular ultrastructural detail (pores, corrugations of cellular membrane, perivascular cell branches) and the impressions left on the resin visible only at high magnifications. PMID:15141474

  19. Central nervous system of Rhipicephalus sanguineus ticks (Acari: Ixodidae): an ultrastructural study.

    PubMed

    Roma, Gislaine Cristina; Nunes, Pablo Henrique; de Oliveira, Patrícia Rosa; Remédio, Rafael Neodini; Bechara, Gervásio Henrique; Camargo-Mathias, Maria Izabel

    2012-09-01

    This study performed the ultrastructural description of the synganglion of Rhipicephalus sanguineus males and females, aiming to contribute to the understanding of the cellular organization of this organ. The results show that the central nervous system of these individuals consists of a mass of fused nerves, named synganglion, from where nerves emerge towards several parts of the body. It is surrounded by the neural lamella, a uniform and acellular layer, constituted by repeated layers of homogeneous and finely granular material. The perineurium is just below, composed of glial cells, which extensions invaginate throughout the nervous tissue. The synganglion is internally divided into an outer cortex, which contains the cellular bodies of the neural cells and an inner neuropile. The neural cells can be classified into two types according to cell size, cytoplasm-nucleus relation, and neurosecretory activity. Type I cells are oval or spherical and present a large nucleus occupying most part of the cytoplasm, which contains few organelles. Type 2 cells are polygonal, present a great cytoplasm volume, and their nuclei are located in the cell periphery. The cytoplasm of these cells contains a well-developed rough endoplasmic reticulum, Golgi regions, mitochondria, and several neurosecretory granules. The subperineurium and the tracheal ramifications are found between the cortex and the neuropile. The latter is formed mainly by neural fibers, tracheal elements, and glial cells. The results obtained show that R. sanguineus males' and females' nervous tissue present an ultrastructural organization similar to the one described in the literature for other tick species. PMID:22610445

  20. The Spectrum of Mitochondrial Ultrastructural Defects in Mitochondrial Myopathy

    PubMed Central

    Vincent, Amy E.; Ng, Yi Shiau; White, Kathryn; Davey, Tracey; Mannella, Carmen; Falkous, Gavin; Feeney, Catherine; Schaefer, Andrew M.; McFarland, Robert; Gorman, Grainne S.; Taylor, Robert W.; Turnbull, Doug M.; Picard, Martin

    2016-01-01

    Mitochondrial functions are intrinsically linked to their morphology and membrane ultrastructure. Characterizing abnormal mitochondrial structural features may thus provide insight into the underlying pathogenesis of inherited and acquired mitochondrial diseases. Following a systematic literature review on ultrastructural defects in mitochondrial myopathy, we investigated skeletal muscle biopsies from seven subjects with genetically defined mtDNA mutations. Mitochondrial ultrastructure and morphology were characterized using two complimentary approaches: transmission electron microscopy (TEM) and serial block face scanning EM (SBF-SEM) with 3D reconstruction. Six ultrastructural abnormalities were identified including i) paracrystalline inclusions, ii) linearization of cristae and abnormal angular features, iii) concentric layering of cristae membranes, iv) matrix compartmentalization, v) nanotunelling, and vi) donut-shaped mitochondria. In light of recent molecular advances in mitochondrial biology, these findings reveal novel aspects of mitochondrial ultrastructure and morphology in human tissues with implications for understanding the mechanisms linking mitochondrial dysfunction to disease. PMID:27506553

  1. The Spectrum of Mitochondrial Ultrastructural Defects in Mitochondrial Myopathy.

    PubMed

    Vincent, Amy E; Ng, Yi Shiau; White, Kathryn; Davey, Tracey; Mannella, Carmen; Falkous, Gavin; Feeney, Catherine; Schaefer, Andrew M; McFarland, Robert; Gorman, Grainne S; Taylor, Robert W; Turnbull, Doug M; Picard, Martin

    2016-01-01

    Mitochondrial functions are intrinsically linked to their morphology and membrane ultrastructure. Characterizing abnormal mitochondrial structural features may thus provide insight into the underlying pathogenesis of inherited and acquired mitochondrial diseases. Following a systematic literature review on ultrastructural defects in mitochondrial myopathy, we investigated skeletal muscle biopsies from seven subjects with genetically defined mtDNA mutations. Mitochondrial ultrastructure and morphology were characterized using two complimentary approaches: transmission electron microscopy (TEM) and serial block face scanning EM (SBF-SEM) with 3D reconstruction. Six ultrastructural abnormalities were identified including i) paracrystalline inclusions, ii) linearization of cristae and abnormal angular features, iii) concentric layering of cristae membranes, iv) matrix compartmentalization, v) nanotunelling, and vi) donut-shaped mitochondria. In light of recent molecular advances in mitochondrial biology, these findings reveal novel aspects of mitochondrial ultrastructure and morphology in human tissues with implications for understanding the mechanisms linking mitochondrial dysfunction to disease. PMID:27506553

  2. Mitochondrial ultrastructure and tissue respiration of pea leaves under clinorotation

    NASA Astrophysics Data System (ADS)

    Brykov, Vasyl

    2016-07-01

    Respiration is essential for growth, maintenance, and carbon balance of all plant cells. Mitochondrial respiration in plants provides energy for biosynthesis, and its balance with photosynthesis determines the rate of plant biomass accumulation (production). Mitochondria are not only the energetic organelles in a cell but they play an essential regulatory role in many basic cellular processes. As plants adapt to real and simulated microgravity, it is very important to understand the state of mitochondria in these conditions. Disturbance of respiratory metabolism can significantly affect the productivity of plants in long-term space flights. We have established earlier that the rate of respiration in root apices of pea etiolated seedlings rose after 7 days of clinorotation. These data indicate the oxygen increased requirement by root apices under clinorotation, that confirms the necessity of sufficient substrate aeration in space greenhouses to provide normal respiratory metabolism and supply of energy for root growth. In etiolated seedlings, substrate supply of mitochondria occurs at the expense of the mobilization of cotyledon nutrients. A goal of our work was to study the ultrastructure and respiration of mitochondria in pea leaves after 12 days of clinorotation during (2 rpm/min). Plants grew at a light level of 180 μµmol m ^{-2} s ^{-1} PAR and a photoperiod of 16 h light/4 h dark. It was showed an essential increase in the mitochondrion area on 53% in palisade parenchyma cells at the sections. Such phenomenon can not be described as swelling of mitochondria, since enlarged mitochondria contained a more quantity of crista 1.76 times. In addition, the cristae total area per organelle also increased in comparison with that in control. An increase in a size of mitochondria in the experimental conditions is supposed to occur by a partial alteration of the chondriom. Thus, a size of 49% mitochondria in control was 0.1 - 0.3 μµm ^{2}, whereas only 26

  3. SIRT1 inhibits the mouse intestinal motility and epithelial proliferation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SIRT1 inhibits the mouse intestinal motility and epithelial proliferation. Sirtuin 1 (SIRT1), a NAD+-dependent histone deacetylase, is involved in a wide array of cellular processes, including glucose homeostasis, energy metabolism, proliferation and apoptosis, and immune response. However, it is un...

  4. Morphology, ultrastructure, and small subunit rDNA phylogeny of the marine heterotrophic flagellate Goniomonas aff. amphinema.

    PubMed

    Martin-Cereceda, Mercedes; Roberts, Emily C; Wootton, Emma C; Bonaccorso, Elisa; Dyal, Patricia; Guinea, Almudena; Rogers, Dale; Wright, Chris J; Novarino, Gianfranco

    2010-01-01

    Marine goniomonads have a worldwide distribution but ultrastructural information has not been available so far. An isolate of the heterotrophic marine nanoflagellate Goniomonas (G. aff. amphinema) from North Wales (UK) has been studied, providing information on its morphology and cellular structure using video, electron, laser scanning confocal microscopy (LSCM), and atomic force microscopy. Here, we describe a new feature, a granular area, potentially involved in particle capture and feeding. The binding of the lectin wheat germ agglutinin to the granular area of cells with discharged ejectisomes indicates the adhesive nature of this novel feature. The presence of a microtubular intracellular cytopharynx, apparently also used for feeding, has been revealed by LSCM. The small subunit rRNA gene of the isolate has been sequenced (1,788 bp). Phylogenetic results corroborate significant genetic divergence within the marine members of Goniomonas. This work highlights the need for integrated morphological, ultrastructural, and molecular investigation when describing and studying heterotrophic nanoflagellates. PMID:20015186

  5. Ultrastructural changes in LGMD1F.

    PubMed

    Cenacchi, Giovanna; Peterle, Enrico; Fanin, Marina; Papa, Valentina; Salaroli, Roberta; Angelini, Corrado

    2013-06-01

    A large Italo-Spanish kindred with autosomal-dominant inheritance has been reported with proximal limb and axial muscle weakness. Clinical, histological and genetic features have been described. A limb girdle muscular dystrophy 1F (LGMD1F) disease locus at chromosome 7q32.1-32.2 has been previously identified. We report a muscle pathological study of two patients (mother and daughter) from this family. Muscle morphologic findings showed increased fiber size variability, fiber atrophy, and acid-phosphatase-positive vacuoles. Immunofluorescence against desmin, myotilin, p62 and LC3 showed accumulation of myofibrils, ubiquitin binding protein aggregates and autophagosomes. The ultrastructural study confirmed autophagosomal vacuoles. Many alterations of myofibrillar component were detected, such as prominent disarray, rod-like structures with granular aspect, and occasionally, cytoplasmic bodies. Our ultrastructural data and muscle pathological features are peculiar to LGMD1F and support the hypothesis that the genetic defect leads to a myopathy phenotype associated with disarrangement of the cytoskeletal network. PMID:23279333

  6. Ultrastructure, biology, and phylogenetic relationships of kinorhyncha.

    PubMed

    Neuhaus, Birger; Higgins, Robert P

    2002-07-01

    The article summarizes current knowledge mainly about the (functional) morphology and ultrastructure, but also about the biology, development, and evolution of the Kinorhyncha. The Kinorhyncha are microscopic, bilaterally symmetrical, exclusively free-living, benthic, marine animals and ecologically part of the meiofauna. They occur throughout the world from the intertidal to the deep sea, generally in sediments but sometimes associated with plants or other animals. From adult stages 141 species are known, but 38 species have been described from juvenile stages. The trunk is arranged into 11 segments as evidenced by cuticular plates, sensory spots, setae or spines, nervous system, musculature, and subcuticular glands. The ultrastructure of several organ systems and the postembryonic development are known for very few species. Almost no data are available about the embryology and only a single gene has been sequenced for a single species. The phylogenetic relationships within Kinorhyncha are unresolved. Priapulida, Loricifera, and Kinorhyncha are grouped together as Scalidophora, but arguments are found for every possible sistergroup relationship within this taxon. The recently published Ecdysozoa hypothesis suggests a closer relationship of the Scalidophora, Nematoda, Nematomorpha, Tardigrada, Onychophora, and Arthropoda. PMID:21708758

  7. Cytological and ultrastructural studies on root tissues

    NASA Technical Reports Server (NTRS)

    Slocum, R. D.; Gaynor, J. J.; Galston, A. W.

    1984-01-01

    The anatomy and fine structure of roots from oat and mung bean seedlings, grown under microgravity conditions for 8 days aboard the Space Shuttle, was examined and compared to that of roots from ground control plants grown under similar conditions. Roots from both sets of oat seedlings exhibited characteristic monocotyledonous tissue organization and normal ultrastructural features, except for cortex cell mitochondria, which exhibited a 'swollen' morphology. Various stages of cell division were observed in the meristematic tissues of oat roots. Ground control and flight-grown mung bean roots also showed normal tissue organization, but root cap cells in the flight-grown roots were collapsed and degraded in appearance, especially at the cap periphery. At the ultrastructural level, these cells exhibited a loss of organelle integrity and a highly-condensed cytoplasm. This latter observation perhaps suggests a differing tissue sensitivity for the two species to growth conditions employed in space flight. The basis for abnormal root cap cell development is not understood, but the loss of these putative gravity-sensing cells holds potential significance for long term plant growth orientation during space flight.

  8. How methylglyoxal kills bacteria: An ultrastructural study.

    PubMed

    Rabie, Erika; Serem, June Cheptoo; Oberholzer, Hester Magdalena; Gaspar, Anabella Regina Marques; Bester, Megan Jean

    2016-01-01

    Antibacterial activity of honey is due to the presence of methylglyoxal (MGO), H2O2, bee defensin as well as polyphenols. High MGO levels in manuka honey are the main source of antibacterial activity. Manuka honey has been reported to reduce the swarming and swimming motility of Pseudomonas aeruginosa due to de-flagellation. Due to the complexity of honey it is unknown if this effect is directly due to MGO. In this ultrastructural investigation the effects of MGO on the morphology of bacteria and specifically the structure of fimbriae and flagella were investigated. MGO effectively inhibited Gram positive (Bacillus subtilis; MIC 0.8 mM and Staphylococcus aureus; MIC 1.2 mM) and Gram negative (P. aeruginosa; MIC 1.0 mM and Escherichia coli; MIC 1.2 mM) bacteria growth. The ultrastructural effects of 0.5, 1.0 and 2 mM MGO on B. substilis and E. coli morphology was then evaluated. At 0.5 mM MGO, bacteria structure was unaltered. For both bacteria at 1 mM MGO fewer fimbriae were present and the flagella were less or absent. Identified structures appeared stunted and fragile. At 2 mM MGO fimbriae and flagella were absent while the bacteria were rounded with shrinkage and loss of membrane integrity. Antibacterial MGO causes alterations in the structure of bacterial fimbriae and flagella which would limit bacteria adherence and motility. PMID:26986806

  9. Ultrastructural radioautography and cytochemistry of lead absorption.

    PubMed Central

    Parmley, R. T.; Barton, J. C.; Conrad, M. E.; Austin, R. L.

    1979-01-01

    Lead is a universal environmental contaminant absorbed largely through the gastrointestinal tract by unknown mechanisms. Because lead absorption is influenced by iron content in the body and diet, we used ultrastructural radioautography and cytochemistry to study absorption of physiologic lead doses in the rat duodenal epithelial cell and compared these findings to those previously reported for iron absorption. Rat duodenal loops exposed in vivo to 210Pb for 1 minute demonstrated the majority of labels on the microvilli, terminal web, and apical cytoplasm. Specimens exposed to radiolead for 10 minutes demonstrated more abundant labeling with a relative increase in labeling of epithelial cell mitochondria, nuclei and basal cytoplasm, as well as phagocytic cells, endothelial cells, and circulating erythrocytes of the lamina propria. Timm's sulfide-silver method localized trace metals in epithelial cells. After administration of lead, a significant increase in staining was observed in microvilli, mitochondria, non-membrane-bound cytoplasm, and nuclear chromatin. The rapid appearance of absorbed lead in epithelial cell mitochondria and nuclei, as well as phagocytic cells in the lamina propria, was distinctly different from that reported for absorbed iron and suggests different mechanisms for the subcellular transport of these cations. The combination of radioautography and Timm's sulfide-silver staining provides the specificity and resolution needed for ultrastructural evaluation of lead absorption and should be useful in further studies of lead metabolism. Images Figure 10 Figure 11 Figure 12 Figure 4 Figure 5 Figure 6 Figure 7 Figure 3 Figure 8 Figure 9 Figures 1-2 PMID:464028

  10. Processing biological tissues for ultrastructural study.

    PubMed

    Mascorro, José A; Bozzola, John J

    2007-01-01

    Biological tissues are passed through numerous procedures before they can be studied at the ultrastructural level with the electron microscope. Chemical fixation is widely used as a method for preserving structural detail and can be performed by simple immersion or total body vascular perfusion. A 2 to 4% solution of glutaraldehyde buffered with 0.1 M sodium phosphate, or a combination of similarly buffered glutaraldehyde and paraformaldehyde, can be used successfully to preserve the fine structure of biological tissues. The material next is washed briefly in the buffer vehicle and then secondarily fixed in 1% osmium tetroxide (osmic acid), which also is buffered with sodium phosphate. The tissue then is thoroughly dehydrated in solutions of ethanol at increasing concentrations of 50%, 70%, 95%, and 100%. After dehydration, tissues are infiltrated for a prescribed time interval with an epoxy embedding medium. After infiltration, specimens are transferred into fresh epoxy resin and polymerized at 60 to 70 degrees C for several hours. This orderly process ultimately yields fixed tissues that are encased in hardened blocks that can be thin-sectioned with an ultramicrotome. The thin sections are counterstained with solutions of heavy metals to add contrast. The material then can be subjected to the electron beam in an electron microscope to produce useful images for ultrastructural study. This overall procedure has been used successfully since the advent of biological electron microscopy to define the minute details of cells and tissues. PMID:17656744

  11. Ultrastructural and immunohistochemical studies of rat epididymis.

    PubMed

    Francavilla, S; De Martino, C; Scorza Barcellona, P; Natali, P G

    1983-01-01

    The anatomical distribution of smooth muscle actin, myosin, fibronectin and basement membrane has been investigated immunohistochemically, using the indirect immunofluorescence technique, in the rat epididymis. The findings were correlated with the ultrastructural organization of the organ. Actin was found to be distributed in the stereociliary region of the epithelial principal cells and in the terminal web region. Actin was also visible along the base of the epithelium. Myosin was detected in the terminal web and in the terminal bar regions of the epithelium. The contractile cells showed a strong stain for both proteins. Basement membrane immunoreactivity was distributed along the epithelial basement membrane and around the contractile cells of the wall. In the cauda, between the epithelium and the contractile cell layers, the lamina propria, containing blood vessels and a thin layer of cells, was negative for all antigens investigated. Fibronectin showed a granular distribution around the contractile cells, mainly in the cauda. The ultrastructural study showed only thin (5-6 nm in diameter) filaments in the stereocilia and terminal web region. Thin filaments were also visible in the cytoplasm of the basal cells, thus suggesting a contractile function of this cell type. The heterogeneous appearance of the contractile cells of the wall seemed to support the different contractile pattern of the epididymal regions: caput, corpus and cauda. The cells present in the lamina propria showed cytoplasmic vesicles with dark granules resembling the "A" cell granules of the endocrine pancreas and gut mucosa cells. PMID:6354463

  12. Spermatogenesis and sperm ultrastructure in the polychaete genus Ophryotrocha (Dorvilleidae)

    NASA Astrophysics Data System (ADS)

    Pfannenstiel, Hans-Dieter; Grünig, Charlotte

    1990-06-01

    The details of spermatogenesis and spermiogenesis are described for Ophryotrocha puerilis. The ultrastructure of mature sperm is shown for O. puerilis, O. hartmanni, O. gracilis, O. diadema, O. labronica, and O. notoglandulata. Clusters of sixteen cells each are proliferated by two stem cells in each setigerous segment of O. puerilis representing the very early stages of both oogenesis and spermatogenesis. In each spermatocyte-I cluster, the cells are interconnected by cytoplasmic bridges. Early, clusters are enveloped by peritoneal sheath cells. These transient gonad walls break down prior to meiosis. The meiotic processes may start in the clusters with the cells still interconnected, or during breakdown of the original cluster, giving rise to smaller subclusters of both spermatocytes I and spermatocytes II with various numbers of cells. Finally, spermatid tetrads are present. As spermiogenesis progresses, the tetrads disintegrate. Golgi vesicles in both spermatocytes and spermatids contain electron-dense material, presumably preacrosomal. The acrosome is formed by such vesicles. In the six species studied here, the acrosomes appear to be of a similar overall structure but are of different shape. Centrioles are usually located beneath the acrosome. The distal centriole forms the basal body of a flagellum-like cytoplasmic process. The microtubules of these flagellar equivalents do not show a normal ciliar arrangement. The flagellar equivalent appears to be non-motile. In O. hartmanni and in O. notoglandulata, a flagellar equivalent is missing. Microtubules originating from the proximal end of the distal centriole stretch to the nuclear envelope. This feature appears to be especially conspicuous in O. puerilis and in O. labronica. In O. labronica and in O. notoglandulata, bundles of microtubules paralleling the cell perimeter appear to stabilise the sperm. Various numbers of mitochondria are either randomly distributed around the nucleus or accumulate on one side

  13. Phytohemagglutinin improves the development and ultrastructure of in vitro-cultured goat (Capra hircus) preantral follicles

    PubMed Central

    Cunha, E.V.; Costa, J.J.N.; Rossi, R.O.D.S.; Silva, A.W.B.; Passos, J.R.S.; Portela, A.M.L.R.; Pereira, D.C.S.T.; Donato, M.A.M.; Campello, C.C.; Saraiva, M.V.A.; Peixoto, C.A.; Silva, J.R.V.; Santos, R.P.

    2013-01-01

    The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles cultured in vitro. Secondary follicles (∼0.2 mm) were isolated from the cortex of caprine ovaries and cultured individually for 6 days in α-MEM+ supplemented with PHA (0, 1, 10, 50, 100, or 200 µg/mL). After 6 days of culture, follicle diameter and survival, antrum formation, ultrastructure and expression of mRNA for FSH receptors (FSH-R), proliferating cell nuclear antigen (PCNA), and neuronal nitric oxide synthase were determined. All treatments maintained follicular survival [α-MEM+ (94.59%); 1 µg/mL PHA (96.43%); 10 µg/mL PHA (84.85%); 50 µg/mL PHA (85.29%); 100 µg/mL PHA (88.57%), and 200 µg/mL PHA (87.50)], but the presence of 10 µg/mL PHA in the culture medium increased the antrum formation rate (21.21%) when compared with control (5.41%, P < 0.05) and ensured the maintenance of oocyte and granulosa cell ultrastructures after 6 days of culture. The expression of mRNA for FSH-R (2.7 ± 0.1) and PCNA (4.4 ± 0.2) was also significantly increased in follicles cultured with 10 µg/mL PHA in relation to those cultured in α-MEM+ (1.0 ± 0.1). In conclusion, supplementation of culture medium with 10 µg/mL PHA maintains the follicular viability and ultrastructure, and promotes the formation of antral cavity after 6 days of culture in vitro. PMID:23558855

  14. Nuclear Proliferation Challenges

    SciTech Connect

    Professor William Potter

    2005-11-28

    William C. Potter, Director of the Center for Non Proliferation Studies and the Center for Russian and Eurasian Studies at the Monterey Institute of International Studies, will present nuclear proliferation challenges following the 2005 Nuclear Non-Proliferation Treaty (NPT) Review Conference. In addition to elucidating reasons for, and implications of, the conference’s failure, Dr. Potter will discuss common ground between nuclear proliferation and terrorism issues and whether corrective action can be taken.

  15. Intra- and interspecific diversity of ultrastructural markers in Scedosporium.

    PubMed

    Stepanova, Amaliya A; de Hoog, G Sybren; Vasilyeva, Nataliya V

    2016-02-01

    Ultrastructural features of conidia, lateral walls of aerial and submerged hyphal cells, and of septal pore apparatus of Scedosporium apiospermum, S. boydii, Pseudallescheria angusta and Scedosporium aurantiacum were studied. Submerged hyphal cells possessed a thick extracellular matrix. Crystalline satellites accessory to the septal pore apparatus were revealed. Fundamental ultrastructural features appeared to be heterogeneous at low taxonomic levels. The closely interrelated members of the S. apiospermum complex showed quantitative ultrastructural variability, but the unambiguously different species S. aurantiacum deviated qualitatively by markers of conidial wall structure, Woronin bodies morphology and presence/absence of crystalline satellites of the septal pore apparatus. PMID:26781370

  16. Hop Shoot Proliferation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hop shoot proliferation disease has been described in Poland., and is associated with phytoplasma infection. Hop shoot proliferation occurs rarely and seems to be of little economic concern in most regions of hop production. Hop shoot proliferation is thought to be caused by aster yellows phytoplas...

  17. Elastofibroma dorsi: a case report with an immunohistochemical and ultrastructural studies.

    PubMed

    Kakudo, Natsuko; Morimoto, Naoki; Ogawa, Takeshi; Hihara, Masakatsu; Koseki, Rina; Kusumoto, Kenji

    2016-03-01

    Elastofibroma is a rare, benign, fibrous tumor formed by the proliferation of characteristic elastic fibers that commonly occurs between the lower margin of the scapula and the ribcage. We undertook a histochemical, immunohistochemical, and ultrastructural study of an elastofibroma dorsi beneath the right scapula of a 77-year-old woman. Tumor cells comprised collagen fiber bundles, numerous elastic fibers, and spindle cells resembling fibroblasts. The elastic and collagen fibers in the tumor were stained positively with Elastic van Gieson and Masson trichrome staining, respectively. Immunostaining showed that the fibroblasts were strongly positive for CD34, positive for vimentin, and weakly positive for α-smooth muscle actin. Ultrastructural observations revealed elastin and microfibrils between numerous irregularly arranged collagen fiber bundles. Signs suggestive of elastin deposition were also evident in the tangled collagen fibers themselves. The fibroblasts contained a large amount of rough endoplasmic reticulum and were surrounded on the outside of cells by microfibrils and collagen fibers. Although fibroblasts may produce large quantities of elastin, microfibrils, and collagen, our findings suggested that the deposition of elastin on collagen fibers may be involved in the formation of abnormal elastic fibers. PMID:26040573

  18. Ultrastructural and Molecular Changes in the Developing Small Intestine of the Toad Bufo regularis

    PubMed Central

    Sakr, S. A.; Badawy, G. M.; El-Borm, H. T.

    2014-01-01

    The ontogenetic development of the small intestine of the toad Bufo regularis was investigated using twofold approaches, namely, ultrastructural and molecular. The former has been done using transmission electron microscope and utilizing the developmental stages 42, 50, 55, 60, 63, and 66. The most prominent ultrastructural changes were recorded at stage 60 and were more evident at stage 63. These included the appearance of apoptotic bodies/nuclei within the larval epithelium, the presence of macrophages, swollen mitochondria, distorted rough endoplasmic reticulum, chromatin condensation, and irregular nuclear envelop, and the presence of large vacuoles and lysosomes. The molecular investigation involved examining DNA content and fragmentation. The results showed that the DNA content decreased significantly during the metamorphic stages 60 and 63 compared with both larval (50 and 55) and postmetamorphic (66) stages. The metamorphic stages (60 and 63) displayed extensive DNA laddering compared with stages 50, 55, and 66. The percentage of DNA damage was 0.00%, 12.91%, 57.26%, 45.48%, and 4.43% for the developmental stages 50, 55, 60, 63, and 66, respectively. In conclusion, the recorded remodeling of the small intestine represents a model for clarifying the mechanism whereby cell death and proliferation are controlled. PMID:24715821

  19. Ultrastructure and properties of Paecilomyces lilacinus spores.

    PubMed

    Holland, R J; Gunasekera, T S; Williams, K L; Nevalainen, K M H

    2002-10-01

    Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability. PMID:12489777

  20. Ultrastructure of internal jugular vein defective valves

    PubMed Central

    Tisato, V; Menegatti, E; Mascoli, F; Gianesini, S; Salvi, F; Secchiero, P

    2015-01-01

    Objectives To study the ultrastructure of intraluminal defects found in the internal jugular vein by using a scanning electron microscopy. Methods Using a scanning electron microscopy, intraluminal septa and/or defective valves blocking the flow in the distal internal jugular vein of seven patients were studied together with the adjacent wall and compared with control specimen. Results The internal jugular veins’ wall showed a significant derangement of the endothelial layer as compared to controls. Surprisingly, no endothelial cells were found in the defective cusps, and the surface of the structure is covered by a fibro-reticular lamina. Conclusions Although the lack of endothelial cells in the internal jugular vein intraluminal obstacles is a further abnormality found in course of chronic cerebrospinal venous insufficiency, our investigation cannot clarify whether this finding is primary or caused by progressive loss of endothelium in relation to altered haemodynamic forces and/or to a past post-thrombotic/inflammatory remodelling. PMID:24972760

  1. Effects of ultrasound upon endothelial cell ultrastructure

    NASA Astrophysics Data System (ADS)

    Rodemer, Claus; Jenne, Jürgen; Fatar, Marc; Hennerici, Michael G.; Meairs, Stephen

    2012-11-01

    A number of new brain applications for therapeutic ultrasound are emerging including drug delivery through BBB opening, enhancement of angiogenesis, sonothrombolysis and neuromodulation. Safety remains important as alterations in the cytoskeleton and tight junctions of endothelial cells have been described. In this study we characterize the in vitro effects of ultrasound on cell morphology using a new human brain cell line (hCMEC/D3). Changes in ultrastructure were analyzed with antibodies against tubulin, actin and catenin. Transport was analyzed by measuring transferrin uptake. No significant changes were seen after continuous wave ultrasound treatment of hCMEC/D3 cells grown in Opticell{trade mark, serif} chambers. We could not observe disassembled actin stress fibers or variations in the microtubule network. However, severe damage occurred in cells cultured in petri dishes.

  2. Ultrastructure and phylogeny of Ustilago coicis *

    PubMed Central

    Zhang, Jing-ze; Guan, Pei-gang; Tao, Gang; Ojaghian, Mohammad Reza; Hyde, Kevin David

    2013-01-01

    Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town, Jinyun County, Zhejiang Province of China. In this paper, ultrastructural assessments on fungus-host interactions and teliospore development are presented, and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon. Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction, and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane. Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium. In addition, internal transcribed spacer (ITS) and large subunit (LSU) sequence data showed that U. coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa (Poaceae). PMID:23549851

  3. Defective enamel ultrastructure in diabetic rodents.

    PubMed

    Atar, M; Atar-Zwillenberg, D R; Verry, P; Spornitz, U M

    2004-07-01

    We investigated six different types of diabetic rodents. Four expressed a genetic obesity resulting in diabetes. One developed diabetes induced by a diet-dependent obesity, and one with genetic diabetes received anti-diabetic medication. The tooth samples were examined under a scanning electron microscope and with an energy dispersive microanalysis (EDX). The electron micrographs showed severe, varying degrees of damage within the six different diabetic animal types, such as irregular crystallite deposition and prism perforations in genetically obese animals compared to less-disordered prism structures in diet-dependent obesity. Anti-diabetic medication resulted in normal enamel ultrastructure. The EDX analysis revealed a reduction in the amount of calcium and phosphorus in all regions affected by diabetes. Based on these animal studies, we suggest that both juvenile diabetes type I (in infants) and adult diabetes type II (in pregnant mothers, affecting the developing foetus) may affect the normal development of teeth in humans. PMID:15242388

  4. Effect of c-myc on the ultrastructural structure of cochleae in guinea pigs with noise induced hearing loss

    SciTech Connect

    Han, Yu; Zhong, Cuiping; Hong, Liu; Wang, Ye; Qiao, Li; Qiu, Jianhua

    2009-12-18

    Noise over-stimulation may induce hair cells loss and hearing deficit. The c-myc oncogene is a major regulator for cell proliferation, growth, and apoptosis. However, the role of this gene in the mammalian cochlea is still unclear. The study was designed to firstly investigate its function under noise condition, from the aspect of cochlear ultrastructural changes. We had established the adenoviral vector of c-myc gene and delivered the adenovirus suspension into the scala tympani of guinea pigs 4 days before noise exposure. The empty adenoviral vectors were injected as control. Then, all subjects were exposed to 4-kHz octave-band noise at 110 dB SPL for 8 h/day, 3 days consecutively. Auditory thresholds were assessed by auditory brainstem response, prior to and 7 days following noise exposure. On the seventh days after noise exposure, the cochlear sensory epithelia surface was observed microscopically and the cochleae were taken to study the ultrastructural changes. The results indicated that auditory threshold shift after noise exposure was higher in the ears treated with Ad.EGFP than that treated with Ad.c-myc-EGFP. Stereocilia loss and the disarrangement of outer hair cells were observed, with greater changes found in the Ad.EGFP group. Also, the ultrastructure changes were severe in the Ad.EGFP group, but not obvious in the Ad.c-myc-EGFP group. Therefore, c-myc gene might play an unexpected role in hearing functional and morphological protection from acoustic trauma.

  5. Ultrastructural features of the early secretory pathway in Trichoderma reesei.

    PubMed

    Nykänen, Marko; Birch, Debra; Peterson, Robyn; Yu, Hong; Kautto, Liisa; Gryshyna, Anna; Te'o, Junior; Nevalainen, Helena

    2016-05-01

    We have systematically analysed the ultrastructure of the early secretory pathway in the Trichoderma reesei hyphae in the wild-type QM6a, cellulase-overexpressing Rut-C30 strain and a Rut-C30 transformant BV47 overexpressing a recombinant BiP1-VenusYFP fusion protein with an endoplasmic reticulum (ER) retention signal. The hyphae were studied after 24 h of growth using transmission electron microscopy, confocal microscopy and quantitative stereological techniques. All three strains exhibited different spatial organisation of the ER at 24 h in both a cellulase-inducing medium and a minimal medium containing glycerol as a carbon source (non-cellulase-inducing medium). The wild-type displayed a number of ER subdomains including parallel tubular/cisternal ER, ER whorls, ER-isolation membrane complexes with abundant autophagy vacuoles and dense bodies. Rut-C30 and its transformant BV47 overexpressing the BiP1-VenusYFP fusion protein also contained parallel tubular/cisternal ER, but no ER whorls; also, there were very few autophagy vacuoles and an increasing amount of punctate bodies where particularly the recombinant BiP1-VenusYFP fusion protein was localised. The early presence of distinct strain-specific features such as the dominance of ER whorls in the wild type and tub/cis ER in Rut-C30 suggests that these are inherent traits and not solely a result of cellular response mechanisms by the high secreting mutant to protein overload. PMID:26699139

  6. The influenza fingerprints: NS1 and M1 proteins contribute to specific host cell ultrastructure signatures upon infection by different influenza A viruses

    SciTech Connect

    Terrier, Olivier; Moules, Vincent; Carron, Coralie; Cartet, Gaeelle; Frobert, Emilie; Yver, Matthieu; Traversier, Aurelien; Wolff, Thorsten; Naffakh, Nadia; and others

    2012-10-10

    Influenza A are nuclear replicating viruses which hijack host machineries in order to achieve optimal infection. Numerous functional virus-host interactions have now been characterized, but little information has been gathered concerning their link to the virally induced remodeling of the host cellular architecture. In this study, we infected cells with several human and avian influenza viruses and we have analyzed their ultrastructural modifications by using electron and confocal microscopy. We discovered that infections lead to a major and systematic disruption of nucleoli and the formation of a large number of diverse viral structures showing specificity that depended on the subtype origin and genomic composition of viruses. We identified NS1 and M1 proteins as the main actors in the remodeling of the host ultra-structure and our results suggest that each influenza A virus strain could be associated with a specific cellular fingerprint, possibly correlated to the functional properties of their viral components.

  7. Phytomonas serpens: cysteine peptidase inhibitors interfere with growth, ultrastructure and host adhesion.

    PubMed

    Santos, André L S; d'Avila-Levy, Claudia M; Dias, Felipe A; Ribeiro, Rachel O; Pereira, Fernanda M; Elias, Camila G R; Souto-Padrón, Thaïs; Lopes, Angela H C S; Alviano, Celuta S; Branquinha, Marta H; Soares, Rosangela M A

    2006-01-01

    In this study, we report the ultrastructural and growth alterations caused by cysteine peptidase inhibitors on the plant trypanosomatid Phytomonas serpens. We showed that the cysteine peptidase inhibitors at 10 microM were able to arrest cellular growth as well as promote alterations in the cell morphology, including the parasites becoming short and round. Additionally, iodoacetamide induced ultrastructural alterations, such as disintegration of cytoplasmic organelles, swelling of the nucleus and kinetoplast-mitochondrion complex, which culminated in parasite death. Leupeptin and antipain induced the appearance of microvillar extensions and blebs on the cytoplasmic membrane, resembling a shedding process. A 40 kDa cysteine peptidase was detected in hydrophobic and hydrophilic phases of P. serpens cells after Triton X-114 extraction. Additionally, we have shown through immunoblotting that anti-cruzipain polyclonal antibodies recognised two major polypeptides in P. serpens, including a 40 kDa component. Flow cytometry analysis confirmed that this cruzipain-like protein has a location on the cell surface. Ultrastructural immunocytochemical analysis demonstrated the presence of the cruzipain-like protein on the surface and in small membrane fragments released from leupeptin-treated parasites. Furthermore, the involvement of cysteine peptidases of P. serpens in the interaction with explanted salivary glands of the phytophagous insect Oncopeltus fasciatus was also investigated. When P. serpens cells were pre-treated with either cysteine peptidase inhibitors or anti-cruzipain antibody, a significant reduction of the interaction process was observed. Collectively, these results suggest that cysteine peptidases participate in several biological processes in P. serpens including cell growth and interaction with the invertebrate vector. PMID:16310789

  8. Effects of chlorpyrifos on the growth and ultrastructure of green algae, Ankistrodesmus gracilis.

    PubMed

    Asselborn, Viviana; Fernández, Carolina; Zalocar, Yolanda; Parodi, Elisa R

    2015-10-01

    The effect of the organophosphorus insecticide chlorpyrifos on the growth, biovolume, and ultrastructure of the green microalga Ankistrodesmus gracilis was evaluated. Concentrations of 9.37, 18.75, 37.5, 75 and 150mgL(-1) of chlorpyrifos were assayed along with a control culture. At the end of the bioassay the ultrastructure of algal cells from control culture and from cultures exposed to 37.5 and 150mgL(-1) was observed under transmission (TEM) and scanning electron microscopy (SEM). After 24 and 48h, treatments with 75 and 150mgL(-1) inhibited the growth of A. gracilis; whereas after 72 and 96h, all the treatments except at 9.37mgL(-1) significantly affected the algae growth. The effective concentration 50 (EC50) after 96h was 22.44mgL(-1) of chlorpyrifos. After the exposure to the insecticide, an increase in the biovolume was observed, with a larger increase in cells exposed to 75 and 150mgL(-1). Radical changes were observed in the ultrastructure of cells exposed to chlorpyrifos. The insecticide affected the cell shape and the distribution of the crests in the wall. At 37.5mgL(-1) electodense bodies were observed along with an increase in the size and number of starch granules. At 150mgL(-1) such bodies occupied almost the whole cytoplasm together with lipids and remains of thylakoids. Autospores formation occurred normally at 37.5mgL(-1) while at 150mgL(-1) karyokinesis occurred, but cell-separation-phase was inhibited. The present study demonstrates that the exposure of phytoplankton to the insecticide chlorpyrifos leads to effects observed at both cellular and population level. PMID:26099464

  9. Ultrastructure: effects of melanin pigment on target specificity using a pulsed dye laser (577 nm)

    SciTech Connect

    Tong, A.K.; Tan, O.T.; Boll, J.; Parrish, J.A.; Murphy, G.F.

    1987-06-01

    It has been shown recently that brief pulses of 577 nm radiation from the tunable dye laser are absorbed selectively by oxyhemoglobin. This absorption is associated with highly specific damage to superficial vascular plexus blood vessels in those with lightly pigmented (type I-II) skin. To determine whether pigmentary differences in the overlying epidermis influence this target specificity, we exposed both type I (fair) and type V (dark) normal human skin to varying radiant exposure doses over 1.5-microsecond pulse durations from the tunable dye laser at a wavelength of 577 nm. Using ultrastructural techniques, we found in type I skin that even clinical subthreshold laser exposures caused reproducible alterations of erythrocytes and adjacent dermal vascular endothelium without comparable damage to the overlying epidermis. In contrast, degenerated epidermal basal cells represented the predominant form of cellular damage after laser exposure of type V skin at comparable doses. We conclude that epidermal melanin and vascular hemoglobin are competing sites for 577 nm laser absorption and damage, and that the target specificity of the 577 nm tunable dye laser is therefore influenced by variations in epidermal pigmentation. This finding is relevant to the clinical application of the tunable dye laser in the ablative treatment of vascular lesions. We also found on ultrastructure that the presence of electron-lucent circular structures of approximately 800 A in diameter were observed only at and above clinical threshold doses in those with type I skin and at the highest dose of 2.75 J/cm2 in type V skin. It has been proposed that these structures might be heat-fixed molds of water vapor. Both this and ultrastructural changes of epidermal basal cells demonstrate mechanisms responsible for alteration of tissue after exposure to 577 nm, which are discussed.

  10. Ultrastructural effects of recombinant gamma-interferon on cultured human keratinocytes.

    PubMed

    Nickoloff, B J; Mahrle, G; Morhenn, V

    1986-01-01

    To extend our initial observations that recombinant gamma-interferon (r gamma IFN) influences the growth and differentiation of normal cultured human keratinocytes, we studied the electron microscopic changes induced by r gamma IFN. Treatment of cultured human keratinocytes with 10(3) units/ml (7.1 nM) of r gamma IFN produced a shift toward an increasing percentage of attached cells that had a mature-type, differentiated appearance rather than a basal type of proliferating cell, as observed in control, untreated cultures. This report extends the number of cell types that can be influenced by r gamma IFN at the ultrastructural level and supports the notion that r gamma IFN can influence both growth and maturation of normal cultured human keratinocytes. PMID:2421470

  11. Myocardial ultrastructure and the development of atrioventricular block in Kearns-Sayre syndrome.

    PubMed

    Charles, R; Holt, S; Kay, J M; Epstein, E J; Rees, J R

    1981-01-01

    A right ventricular endomyocardial biopsy specimen from a 30-year-old male with chromic progressive external ophthalmoplegia, retinal pigmentation and complete atrioventricular block (Kearns-Sayre syndrome) was examined in the electron microscope. There was a proliferation of mitochondria between the myofibrils and beneath the sarcolemma. Many of the mitochondria showed morphologic abnormalities not previously described in this condition. There were associated accumulations of glycogen. A similarly affected female with left anterior hemiblock developed complete atrioventricular block at age 26 years, Despite the ultrastructural changes, clinically detectable myocardial disease is not a feature of Kearns-Sayre syndrome. However, intraventricular conduction defects show an unusually rapid progression to potentially fatal complete atrioventricular block and are an indication for prophylactic cardiac pacing. PMID:7438396

  12. Active Cellular Nematics

    NASA Astrophysics Data System (ADS)

    Duclos, Guillaume; Erlenkaemper, Christoph; Garcia, Simon; Yevick, Hannah; Joanny, Jean-François; Silberzan, Pascal; Biology inspired physics at mesoscales Team; Physical approach of biological problems Team

    We study the emergence of a nematic order in a two-dimensional tissue of apolar elongated fibroblast cells. Initially, these cells are very motile and the monolayer is characterized by giant density fluctuations, a signature of far-from-equilibrium systems. As the cell density increases because of proliferation, the cells align with each other forming large perfectly oriented domains while the cellular movements slow down and eventually freeze. Therefore topological defects characteristic of nematic phases remain trapped at long times, preventing the development of infinite domains. By analogy with classical non-active nematics, we have investigated the role of boundaries and we have shown that cells confined in stripes of width smaller than typically 500 µm are perfectly aligned in the stripe direction. Experiments performed in cross-shaped patterns show that both the number of cells and the degree of alignment impact the final orientation. Reference: Duclos G., Garcia S., Yevick H.G. and Silberzan P., ''Perfect nematic order in confined monolayers of spindle-shaped cells'', Soft Matter, 10, 14, 2014

  13. Ultrastructural Characterization of Fresh and Vitrified In Vitro- and In Vivo-Produced Sheep Embryos.

    PubMed

    Romão, R; Bettencourt, E; Pereira, R M L N; Marques, C C; Baptista, M C; Barbas, J P; Oliveira, E; Bettencourt, C; Sousa, M

    2016-06-01

    The lower results in cryopreservation of in vitro-produced (IVP) sheep embryos, when compared to the in vivo derived, limits its use. Four groups of blastocyst (BL) were evaluated: fresh IVP (n = 3), fresh in vivo derived (n = 3), warmed IVP cryopreserved in open pulled straws (OPS, n = 3) and warmed in vivo derived cryopreserved in OPS (n = 3). Ultrastructural observation of processed fresh embryos showed a reduced number of microvilli and mitochondria in the IVP ones, as well as a lower number of mature mitochondria, that can be associated with deficient metabolism in IVP embryos, possibly involved in the lower resistance to cryopreservation. Both in vivo-derived and IVP embryos had a large number of vesicles, with light and dense content. In embryos vitrified by OPS, major changes were observed mainly in IVP embryos with small changes in grade 2 (fair) and high changes in grade 3 (bad) semithin scoring. The main changes associated with cryopreservation included disruption of cellular membranes and poor intracellular preservation, with loss of microvilli and the presence of cellular debris. In conclusion, ultrastructural evaluation of IVP blastocysts cryopreserved in OPS was herein described for the first time, reporting more severe cellular damage in these embryos when compared to those produced in vivo. This is probably associated with a lower cryotolerance that can be related to their lipid content and metabolism. PMID:27144917

  14. Cardiac ultrastructure and electrocardiogram of the short-tailed shrew, Blarina brevicauda.

    PubMed

    Pfeiffer, C J; Keith, J C

    1993-10-01

    The smaller species of shrews have been of considerable interest to scientists because of their high rate of metabolism, structure-functional and behavioral adaptations to support their energy demands. The present data are the first detailed cardiac ultrastructural findings and electrocardiographic (ECG) data of adult and immature small short-tailed shrews, Blarina brevicauda. The heart is morphologically elongated and heart rates in excess of 900 b/min were observed, but ECG components and pattern are non-distinctive for this species. Ultrastructurally, the sarcomeres, tubular and sarcotubular systems and Purkinje cells resemble closely those observed in larger, less active mammals. Several distinctive features resembling those seen in some other shrews or hummingbirds exist, including reduced quantities of myocyte glycogen, irregularly shaped and tightly packed mitochondria, increased neural and vascular elements in the myocardium, and small size and unusual dispersion of atrial specific granules. These morphologic findings suggest that the remarkable physiologic performance of the heart of Blarina brevicauda is supported by a combination of macroscopic, histologic and cellular adaptations. PMID:8269404

  15. Synaptic plasticity and gravity: Ultrastructural, biochemical and physico-chemical fundamentals

    NASA Astrophysics Data System (ADS)

    Rahmann, H.; Slenzka, K.; Körtje, K. H.; Hilbig, R.

    On the basis of quantitative disturbances of the swimming behaviour of aquatic vertebrates (``loop-swimming'' in fish and frog larvae) following long-term hyper-g-exposure the question was raised whether or not and to what extent changes in the gravitational vector might influence the CNS at the cellular level. Therefore, by means of histological, histochemical and biochemical analyses the effect of 2-4 x g for 9 days on the gross morphology of the fish brain, and on different neuronal enzymes was investigated. In order to enable a more precise analysis in future-μg-experiments of any gravity-related effects on the neuronal synapses within the gravity-perceptive integration centers differentiated electron-microscopical and electronspectroscopical techniques have been developed to accomplish an ultrastructural localization of calcium, a high-affinity Ca2+-ATPase, creatine kinase and cytochrome oxidase. In hyper-g animals vs. 1-g controls, a reduction of total brain volume (15 %), a decrease in creatine kinase activity (20 %), a local increase in cytochrome oxidase activity, but no differences in Ca2+/Mg2+-ATPase activities were observed. Ultrastructural peculiarities of synaptic contact formation in gravity-related integration centers (Nucleus magnocellularis) were found. These results are discussed on the basis of a direct effect of hyper-gravity not only on the gravity-sensitive neuronal integration centers but possibly also on the physico-chemical properties of the lipid bilayer of neuronal membranes in general.

  16. Ecophysiological and ultrastructural effects of dust pollution in lichens exposed around a cement plant (SW Slovakia).

    PubMed

    Paoli, Luca; Guttová, Anna; Grassi, Alice; Lackovičová, Anna; Senko, Dušan; Sorbo, Sergio; Basile, Adriana; Loppi, Stefano

    2015-10-01

    The study investigated the ecophysiological and ultrastructural effects of dust pollution from a cement industry in the lichen species Evernia prunastri and Xanthoria parietina, which were exposed for 30, 90 and 180 days around a cement mill, two quarries, and inhabited and agricultural sites in SW Slovakia. The results showed that dust deposition from quarrying activities and cement works at the cement mill (mainly enriched in Ca, Fe and Ti) significantly affected the photosynthetic apparatus of E. prunastri (sensitive to dust and habitat eutrophication), while X. parietina (tolerant to dust and habitat eutrophication) adapted to the new environment. The length of the exposure strongly affected the vitality of the mycobiont (measured as dehydrogenase activity) in transplanted lichens. Dust deposition led to ultrastructural alterations, including lipid droplets increase, swelling of cellular components, thylakoid degeneration and sometimes plasmolysis, which, on the whole, gave the cells an aged appearance. Photosynthetic parameters deserve further attention as potential indicators for monitoring early biological symptoms of the air pollution caused during cement production. PMID:26044142

  17. Ultrastructural characterization of the rabbit mandibular condyle following experimental induction of anterior disk displacement.

    PubMed

    Sharawy, M; Ali, A M; Choi, W S; Larke, V

    2000-01-01

    Previous studies in our laboratory have shown that surgical induction of anterior disk displacement (ADD) in the rabbit craniomandibular joint (CMJ) leads to cellular and extracellular alterations consistent with osteoarthritis. Similar findings were also reported in human ADD as well as osteoarthritis of other joints. The purpose of this study was to further characterize these histopathological findings at the ultrastructural level. The right joint of 15 rabbits was exposed surgically and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. Ten additional joints were used as nonoperated controls. Mandibular condyles were excised 2 weeks following surgery and processed for transmission electron microscopy. Experimental condyles showed neovascularization, fibrillation and vacuolation of the extracellular matrix and an increase in the number of apoptotic cells compared to controls. In addition, chondrocytes in osteoarthritic cartilage showed an increase in the amounts of rough endoplasmic reticulum and Golgi complex suggesting an increase in protein synthesis. The presence of thick collagen fibers in osteoarthritic cartilage supports our previous immunohistochemical results of the presence of type I collagen instead of normally existing type II collagen. It was concluded that surgical induction of ADD in the rabbit CMJ leads to ultrastructural changes in the mandibular condylar cartilage consistent with degenerative alterations known to occur in osteoarthritis. PMID:10899715

  18. Spent metal working fluids produced alterations on photosynthetic parameters and cell-ultrastructure of leaves and roots of maize plants.

    PubMed

    Grijalbo, Lucía; Fernandez-Pascual, Mercedes; García-Seco, Daniel; Gutierrez-Mañero, Francisco Javier; Lucas, Jose Antonio

    2013-09-15

    In this work we assess the capacity of maize (Zea mays) plants to phytoremediate spent metal working fluids (MWFs) and its effects on photosynthesis and ultrastructure of mesophyll and root cells. A corn-esparto fibre system patented by us has been used to phytoremediate MWFs in hydroponic culture. Furthermore, a plant growth promoting rhizobacteria (PGPR) has been used to improve the process. The results show that this system is capable of significantly reducing the chemical oxygen demand, under local legislation limits. However, plant systems are really damaged, mainly its photosynthetic system, as shown by the photosynthetical parameters. Nevertheless, strain inoculated improves these parameters, especially Hill reaction. The ultrastructure of photosynthetic apparatus was also affected. Chloroplast number decreased and becomes degraded in the mesophyll of MWFs treated plants. In some cases even plasmolysis of chloroplast membrane was detected. Early senescence symptoms were detected in root ultrastructural study. Severe cellular damage was observed in the parenchymal root cells of plants grown with MWFs, while vascular bundles cell remained unchanged. It seems that the inoculation minimises the damage originated by the MWFs pollutants, appearing as less degenerative organelles and higher chloroplast number than in non-inoculated ones. PMID:23770488

  19. Epithelial Proliferation on Curved Toroidal Surfaces

    NASA Astrophysics Data System (ADS)

    Chang, Ya-Wen; Cruz, Ricardo; Fragkopoulos, Alexandros; Marquez, Samantha; Garcia, Andres; Fernandez-Nieves, Alberto

    Cellular environment influences a multitude of cellular functions by providing chemical and physical signals that modulate cell behavior, dynamics, development, and eventually survival. In strongly interacting epithelial cells, cells coordinate their behavior to respond to mechanical constraints in 2D. Local differences in tissue tension has also been shown to impact cell reproduction within an epithelial-cell sheet. Much less is known about how cells respond to out-of-plane curvatures. Here, we describe the proliferation of MDCK on toroidal hydrogel substrates, which unlike spheres or planes, have regions of both positive and negative Gaussian curvature. Additionally, the range of curvatures can be controlled by varying the size and aspect ratio of the torus, allowing us to quantify the relation between substrate curvature and cell proliferation.

  20. Fractal Dimensions of In Vitro Tumor Cell Proliferation

    PubMed Central

    Lambrou, George I.

    2015-01-01

    Biological systems are characterized by their potential for dynamic adaptation. One of the challenges for systems biology approaches is their contribution towards the understanding of the dynamics of a growing cell population. Conceptualizing these dynamics in tumor models could help us understand the steps leading to the initiation of the disease and its progression. In vitro models are useful in answering this question by providing information over the spatiotemporal nature of such dynamics. In the present work, we used physical quantities such as growth rate, velocity, and acceleration for the cellular proliferation and identified the fractal structures in tumor cell proliferation dynamics. We provide evidence that the rate of cellular proliferation is of nonlinear nature and exhibits oscillatory behavior. We also calculated the fractal dimensions of our cellular system. Our results show that the temporal transitions from one state to the other also follow nonlinear dynamics. Furthermore, we calculated self-similarity in cellular proliferation, providing the basis for further investigation in this topic. Such systems biology approaches are very useful in understanding the nature of cellular proliferation and growth. From a clinical point of view, our results may be applicable not only to primary tumors but also to tumor metastases. PMID:25883653

  1. Resolving new ultrastructural features of cytokinetic abscission with soft-X-ray cryo-tomography.

    PubMed

    Sherman, Shachar; Kirchenbuechler, David; Nachmias, Dikla; Tamir, Adi; Werner, Stephan; Elbaum, Michael; Elia, Natalie

    2016-01-01

    Mammalian cytokinetic abscission is mediated by the ESCRT membrane fission machinery. While much has been clarified on the topology and kinetics of abscission through high-resolution microscopy, key questions regarding the mechanism of abscission remain open. Here we apply cryogenic soft-X-ray tomography to elucidate new ultrastructural details in the intercellular membrane bridge connecting cells undergoing abscission. In particular, we resolve defined ring-like structures inside the midbody dark zone that have been inaccessible to EM, and identify membrane extrusions at the abscission sites. In cells at late stages of abscission we resolve a complex array of helical spirals, extending the structural information obtained by EM. Our results highlight the advantages of soft-X-ray tomography and emphasize the importance of using complementary approaches for characterizing cellular structures. Notably, by providing new structural data from intact cells we present a realistic view on the topology of abscission and suggest new mechanistic models for ESCRT mediated abscission. PMID:27282220

  2. Ultrastructural modification of the ciliate protozoan, Colpidium colpoda following chronic exposure to partially degraded crude oil

    SciTech Connect

    Rogerson, A.; Berger, J.

    1982-06-01

    Protozoa are important consumers of the microflora that biodegrade oil spills. In the study presented, the ultrastructural effects induced by chronic oil stress in the ciliate protozoan, Colpidium colpoda are discussed. Colpidia were grown in control cultures containing a dilute organic medium and a dense suspension of prey bacteria. After 20 days' oil exposure, C. colpoda contained more stained cytoplasmic inclusions than ciliates grown in the control media. Although the extent of Sudan Black staining in the oil-stressed cells indicates the presence of lipids, these droplets are better termed lipid-hydrocarbon (LH) inclusions until their definitive composition is known. C. colpoda accumulated significant quantities of lipid-hydrocarbons accounting for up to 20% of their cellular volume. Studies are currently being conducted to characterized these inclusions and to evaluate the effects of feeding these ''oil-labeled'' prey to predators, an important issue with the increasing concern about the biomagnification of environmental pollutants. (JMT)

  3. Micro- and nano-CT for the study of bone ultrastructure.

    PubMed

    Peyrin, Françoise; Dong, Pei; Pacureanu, Alexandra; Langer, Max

    2014-12-01

    Micro-computed tomography (micro-CT)-a version of X-ray CT operating at high spatial resolution-has had a considerable success for the investigation of trabecular bone micro-architecture. Currently, there is a lot of interest in exploiting CT techniques at even higher spatial resolutions to assess bone tissue at the cellular scale. After recalling the basic principles of micro-CT, we review the different existing system, based on either standard X-ray tubes or synchrotron sources. Then, we present recent applications of micro- and nano-CT for the analysis of osteocyte lacunae and the lacunar-canalicular network. We also address the question of the quantification of bone ultrastructure to go beyond the sole visualization. PMID:25292366

  4. Pyrazole prevention of CC14-induced ultrastructural changes in rat liver.

    PubMed Central

    Bernacchi, A. S.; de Castro, C. R.; de Toranzo, E. G.; Marzi, A.; de Ferreyra, E. C.; de Fenos, O. M.; Castro, J. A.

    1980-01-01

    Carbon tetrachloride (CC14) administration to rats leads to an early dilatation, vesiculation and disorganization of the liver endoplasmic reticulum (ER). This hepatotoxin also causes detachment of ribosomes from ER membranes, dilatation of the Golgi cisternae and occasionally dilatation of the perinuclear membrane. Prior treatment of the rats with pyrazole completely prevents CC14- induced ultrastructural alterations observed in liver at 3 h. This drug is known to decrease the intensity of the irreversible binding of CC14 reactive metabolites to cellular constituents without modifying the intensity of the CC14- induced lipid peroxidation, either in vitro or in vivo, as measured by the diene conjugation procedure or by decreases inthe arachidonic acid content of microsomal phospholipids. Results suggest that interaction of reactive metabolites rather than lipid peroxidation mediates deleterious effects of CCl4 on the liver ER. Images Fig. 1 Fig. 2 Fig. 3 PMID:7448119

  5. Resolving new ultrastructural features of cytokinetic abscission with soft-X-ray cryo-tomography

    PubMed Central

    Sherman, Shachar; Kirchenbuechler, David; Nachmias, Dikla; Tamir, Adi; Werner, Stephan; Elbaum, Michael; Elia, Natalie

    2016-01-01

    Mammalian cytokinetic abscission is mediated by the ESCRT membrane fission machinery. While much has been clarified on the topology and kinetics of abscission through high-resolution microscopy, key questions regarding the mechanism of abscission remain open. Here we apply cryogenic soft-X-ray tomography to elucidate new ultrastructural details in the intercellular membrane bridge connecting cells undergoing abscission. In particular, we resolve defined ring-like structures inside the midbody dark zone that have been inaccessible to EM, and identify membrane extrusions at the abscission sites. In cells at late stages of abscission we resolve a complex array of helical spirals, extending the structural information obtained by EM. Our results highlight the advantages of soft-X-ray tomography and emphasize the importance of using complementary approaches for characterizing cellular structures. Notably, by providing new structural data from intact cells we present a realistic view on the topology of abscission and suggest new mechanistic models for ESCRT mediated abscission. PMID:27282220

  6. Cellular Functions of Transient Receptor Potential channels

    PubMed Central

    Dadon, Daniela; Minke, Baruch

    2010-01-01

    Transient Receptor Potential channels are polymodal cellular sensors involved in a wide variety of cellular processes, mainly by increasing cellular Ca2+. In this review we focus on the roles of these channels in: i) cell death ii) proliferation and differentiation and iii) synaptic vesicle release. Cell death Ca2+ influx participates in apoptotic and necrotic cell death. The Ca2+ permeability and high sensitivity of part of these channels to oxidative/metabolic stress make them important participants in cell death. Several examples are given. Transient Receptor Potential Melastatin 2 is activated by H2O2, inducing cell death through an increase in cellular Ca2+ and activation of Poly ADP-Ribose Polymerase. Exposure of cultured cortical neurons to oxygen-glucose deprivation, in vitro, causes cell death via cation influx, mediated by Transient Receptor Potential Melastatin 7. Metabolic stress constitutively activates the Ca2+ permeable Transient Receptor Potential channels of Drosophila photoreceptor in the dark, potentially leading to retinal degeneration. Similar sensitivity to metabolic stress characterizes several mammalian Transient Receptor Potential Canonical channels. Proliferation and differentiation The rise in cytosolic Ca2+ induces cell growth, differentiation and proliferation via activation of several transcription factors. Activation a variety of store operated and Transient Receptor Potential channels cause a rise in cytosolic Ca2+, making these channels components involved in proliferation and differentiation. Synaptic vesicle release Transient Receptor Potential Melastatin 7 channels reside in synaptic vesicles and regulate neurotransmitter release by a mechanism that is not entirely clear. All the above features of Transient Receptor Potential channels make them crucial components in important, sometimes conflicting, cellular processes that still need to be explored. PMID:20399884

  7. Ultrastructural cytochemical analysis of intranuclear arsenic inclusions

    SciTech Connect

    Sorensen, E.M.B.

    1987-01-01

    To establish the chemical composition of the arsenic inclusion, freshly isolated preparations of inclusions and epon-embedded thin sections of inclusions were subjected to ultrastructural cytochemical analysis. Intranuclear inclusions are composed of amorphous, arsenic-containing subunits aligned linearly to form a coiled complex. Lipase, ribonuclease, deoxyribonuclease, trypsin, pepsin, protease, amylase, or ethylenediaminetetraacetic acid (EDTA) was used to digest or chelate these inclusions. Following enzymatic digestion or chelation, the electron opacity of inclusions was compared with that of control sections exposed for equal times to equivalent solutions lacking the enzymes. Exposure to amylase caused a consistent reduction in the electron opacity of thin sections of inclusions and almost complete digestion of the freshly isolated preparations of inclusions. This was indicative of the presence of a carbohydrate moiety within arsenic inclusions. Incubation of inclusions with EDTA resulted in solubilization of freshly isolated and thin-sectioned embedded material. These data indicated that the intranuclear arsenic inclusion is composed of both metallic and carbohydrate moieties, confirming earlier studies which identified arsenic within inclusions using instrumental neutron activation analysis and x-ray microprobe analysis.

  8. Ochronotic arthropathy: structural and ultrastructural features.

    PubMed

    Melis, M; Onori, P; Aliberti, G; Vecci, E; Gaudio, E

    1994-01-01

    Fragments of articular cartilage and synovial membrane in a case of ochronosis were studied by light microscopy (LM), polarized light, and transmission electron microscopy (TEM). Granular and/or shard-shaped pigments were observed in the synovia, cartilage, and subchondral tissue, and dispersed pigment was also seen in the synovial fluid. Zones of the articular cartilage surface showed small erosions near shards, and sometimes, when the degenerative process was in an advanced stage, a substitutive fibrosis of the cartilage edge was demonstrated. LM and TEM observations of the samples studied revealed an alteration of collagen fibrils that appeared wavy and sometimes fragmented with loss of periodicity. They were always mixed with the dispersed pigment. A peculiar finding that characterized this ochronotic case was the complete absence of inflammatory infiltrates or signs of monocyte-macrophage activation. These structural and ultrastructural observations suggest that the pigment deposition in the articular surfaces was due to the synovial fluid circulation and partially to subchondral blood flow, which transports and stores the ochronotic pigments in the synovia and cartilage. These etiopathologic elements associated with the mechanical pathogenesis naturally present in the joints can contribute to the explanation of the pathogenesis and origin of ochronotic arthropathy. PMID:7809996

  9. Gonadoblastoma: ultrastructural evidence for testicular origin.

    PubMed

    Ishida, T; Tagatz, G E; Okagaki, T

    1976-04-01

    A gonadoblastoma arising in the dysgenetic gonad of a virilized 17-year-old Caucasian with a female phenotype and with a 45,X0/46, X-ring-Y genotype was studied by light microscopic histochemistry, electron microscopy, and ultrastructural histochemistry. The gonadoblastoma was composed of nests of cells containg large germ cells and small "granulosa-Sertoli-like cells," and stromal tissue containing "Leydig-like cells." The germ cells were identical to those found in normal fetal gonads and in germ cell tumors. Charcot-Böttcher crystalloids present in the "granulosa-Sertoli-like cells" strongly suggest that they are, in fact, Sertoli cells. Multilayered basal laminae located in the periphery of the tumor nests and in "hyaline bodies" were identical to those surrounding the seminiferous tubules of the adult testis. The "Leydig-like cells" present in the stroma contained occasional dense bodies and crystalloids which characterize the Leydig cells of the fetal testis. Delta 5-3 beta hydroxysteroid dehydrogenase activity was demonstrated in the periphery of lipid droplets and lysosome-like dense bodies of the Leydig cells, and in some Sertoli cells. The findings support the theory that gonadoblastoma arises in a dysgenetic testis rather than in a dysgenetic ovary. PMID:1260688

  10. Morphogenesis and Ultrastructure of Geotrichum candidum Septa

    PubMed Central

    Hashimoto, Tadayo; Morgan, J.; Conti, S. F.

    1973-01-01

    The ultrastructure and mode of formation of septa of Geotrichum candidum were investigated by light and electron microscopy. The invaginations of the lateral membrane and wall appear to initiate at multiple points around the circumference of the cell; the immature septum subsequently assumes a cart-wheel shape, with branched spokes radiating from the center of the septum. Each face of the septum is covered with a membrane possessing hitherto undescribed structural differentiation; the membrane substructures are comprised of two central subunits encircled by 12 identical subunits. The diameter of the entire 12 plus 2 structure is 24 to 25 nm, and the diameter of each individual subunit is approximately 4 nm. The maturation of the septum appears to occur by further deposition of material along the branched skeletal regions. Numerous small openings (micropores), formed as a result of incomplete deposition, ultimately give rise to plasmodesmata. During arthrospore formation, the plasmodesmal canals and associated micropores are occluded by electron-dense materials, rendering each segment of the hyphae completely independent of the rest of the hyphae. Images PMID:4126819

  11. Comparative ultrastructure of ant spermatozoa (Formicidae: Hymenoptera).

    PubMed

    Wheeler, D E; Crichton, E G; Krutzsch, P H

    1990-12-01

    Mature spermatozoa from spermathecae of founding queens were obtained from 5 species of ants, representing the major subfamilies Myrmicinae (Acromyrmex versicolor, Crematogaster sp.) and Dolichoderinae (Tapinoma sessile, Conomyrma insana, Conomyrma wheeleri). The ultrastructure of ant spermatozoa has many features in common with that of higher insects and is similar to that of other Hymenoptera. Structural similarities to spermatozoa of other Hymenoptera include an acrosome containing an internal rod that extends into the nucleus, two elongate mitochondrial derivatives, a centriolar adjunct, and an axonemal arrangement of 9 + 9 + 2 that includes well-developed coarse, or accessory, tubules. Spermatozoa obtained from A. versicolor, a species that is known to store and utilize viable sperm from this supply for over 10 years, show greater development of the mitochondrial derivatives than do the other species. The most distinctive feature of ant spermatozoa in comparison to other Hymenoptera is the large size of the centriolar adjunct relative to the other organelles. The centriolar adjunct is located posterior to the nucleus, anterior to the mitochondrial derivatives, and opposite the axoneme. PMID:2280410

  12. Ultrastructure of mitochondrial nucleoid and its surroundings.

    PubMed

    Prachař, Jarmil

    2016-07-01

    Mitochondrial nucleoids (hereafter nucleoids) contain genetic information, mitochondrial DNA, prerequisite for mitochondrial functioning, particularly information required for mitochondrial electron transport. To understand nucleoid functioning, it is imperative to know its ultrastructure and dynamics in the context of the actual mitochondrial state. In this study, we document the internal structure, different positions of nucleoids inside the mitochondrial tube and their different morphology. The nucleoid cores appear in section as circular or slightly oval objects ranging from 50 to 100 nm in diameter. They are mainly located in the matrix between cristae inside the mitochondrial tube but they are also frequently found close to the inner mitochondrial surface. In tightly packed form, their interior exhibits sophisticated nucleoprotein regularity. The core surroundings form an electron-lucent thick layer which is probably partitioned into separate chambers. We suggest that the morphology of nucleoids mirrors the mode of energy production, glycolysis versus oxidative phosphorylation. The new high resolution transmission electron microscopy method enabled us to obtain morphological characteristics on yet unpublished level. PMID:27174900

  13. Food restriction modifies ultrastructure of hippocampal synapses.

    PubMed

    Babits, Réka; Szőke, Balázs; Sótonyi, Péter; Rácz, Bence

    2016-04-01

    Consumption of high-energy diets may compromise health and may also impair cognition; these impairments have been linked to tasks that require hippocampal function. Conversely, food restriction has been shown to improve certain aspects of hippocampal function, including spatial memory and memory persistence. These diet-dependent functional changes raise the possibility that the synaptic structure underlying hippocampal function is also affected. To examine how short-term food restriction (FR) alters the synaptic structure of the hippocampus, we used quantitative electron microscopy to analyze the organization of neuropil in the CA1 stratum radiatum of the hippocampus in young rats, consequent to reduced food. While four weeks of FR did not modify the density, size, or shape of postsynaptic spines, the synapses established by these spines were altered, displaying increased mean length, and more frequent perforations of postsynaptic densities. That the number of perforated synapses (believed to be an indicator of synaptic enhancement) increased, and that the CA1 spine population had on average significantly longer PSDs suggests that synaptic efficacy of axospinous synapses also increased in the CA1. Taken together, our ultrastructural data reveal previously unrecognized structural changes at hippocampal synapses as a function of food restriction, supporting a link between metabolic balance and synaptic plasticity. © 2015 Wiley Periodicals, Inc. PMID:26386363

  14. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions

    NASA Technical Reports Server (NTRS)

    Cook, Martha E.; Croxdale, Judith G.; Tibbitts, T. W. (Principal Investigator)

    2003-01-01

    Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions.

  15. The cytochemical and ultrastructural characteristics of phagocytes in the Pacific oyster Crassostrea gigas.

    PubMed

    Jiang, Shuai; Jia, Zhihao; Xin, Lusheng; Sun, Ying; Zhang, Ran; Wang, Weilin; Wang, Lingling; Song, Linsheng

    2016-08-01

    Phagocytes have been proved to play vital roles in the innate immune response. However, the cellular characteristics of phagocytes in invertebrates, especially in molluscs, remain largely unknown. In the present study, fluorescence activated cell sorting (FACS) was employed to sort the phagocytes from the non-phagocytic haemocytes of the Pacific oyster Crassostrea gigas. The cytochemical staining analysis revealed that phagocytes were positive staining for α-naphthyl acetate esterase and myeloperoxidase, while negative staining for toluidine blue and periodic acid-Schiff. The non-phagocytic haemocytes exhibited positive staining for periodic acid-Schiff, weak positive staining for toluidine blue, but negative staining for α-naphthyl acetate esterase and myeloperoxidase. In addition, phagocytes exhibited ultrastructural cellular features similar to those of macrophages, with large cell diameter, rough cell membrane and extended pseudopodia revealed by the scanning electron microscopy, while the non-phagocytic haemocytes exhibited small cell diameter, smooth cell surface and round spherical shape. Transmission electron microscopy further demonstrated that phagocytes were abundant of cytoplasmic bodies and mitochondria, while non-phagocytic haemocytes were characterized as the comparatively large cell nucleus with contorted and condensed heterochromatin adherent to the nuclear envelope. Moreover, compared with non-phagocytic haemocytes, phagocytes exhibited significantly higher levels of intracellular cytokines, including tumor necrosis factor, interferon-like protein and interleukin-17, and significantly higher abundance of lysosome and reactive oxygen species, which were of great importance to the activation of immune response and pathogen clearance. Taken together, these findings revealed the different cytochemical and ultrastructural features between phagocytes and non-phagocytic haemocytes in C. gigas, which would provide an important clue to investigate the

  16. Ultrastructure of pea and cress root statocytes exposed to high gradient magnetic field

    NASA Astrophysics Data System (ADS)

    Belyavskaya, N. A.; Chernishov, V. I.; Polishchuk, O. V.; Kondrachuk, A. V.

    As it was demonstrated by Kuznetsov & Hasenstein (1996) the high gradient magnetic field (HGMF) can produce a ponderomotive force that results in displacements of amyloplasts and causes the root response similar to the graviresponse. It was suggested that the HGMF could allow to imitate the effects of gravity in microgravity and/or change them in laboratory conditions correspondingly, as well as to study statolith-related processes in graviperception. Therefore, the correlation between the direction of the ponderomotive force resulting in statolith displacements and the direction of the HGMF-induced plant curvature can be the serious argument to support this suggestion and needs the detailed ultrastructural analysis. Seeds of dicotyledon Pisum sativum L. cv. Damir-2 and monocotyledon Lepidium sativum L. cv. P896 were soaked and grown in a vertical position on moist filter paper in chambers at room temperature. Tips of primary roots of vertical control, gravistimulated and exposed to HGMF seedlings were fixed for electron microscopy using conventional techniques. At ultrastructural level, we observed no significant changes in the volume of the individual statocytes or amyloplasts, relative volumes of cellular organelles (except vacuoles), number of amyloplasts per statocyte or surface area of endoplasmic reticulum. No consistent contacts between amyloplasts and any cellular structures, including plasma membrane, were revealed at any stage of magneto- and gravistimulation. By 5 min after onset of magnetostimulation, amyloplasts were located along cell wall distant from magnets. In HGMF, the locations of amyloplasts in columella cells were similar to those in horizontally-oriented roots up to 1 h stimulation. In the latter case, there were sometimes cytoplasmic spherical bodies with a dense vesicle-rich cytoplasm in pea statocytes, which were absent in seedlings exposed to HGMF. In cress root statocytes, both gravi- and magnetostimulation were found to cause the

  17. The versatile electron microscope: an ultrastructural overview of autophagy.

    PubMed

    Biazik, Joanna; Vihinen, Helena; Anwar, Tahira; Jokitalo, Eija; Eskelinen, Eeva-Liisa

    2015-03-01

    Both light microscopy (LM) and electron microscopy (EM) are able to reveal important information about the formation and function of various autophagic compartments. In this article we will outline the various techniques that are emerging in EM, focusing on analyzing three-dimensional morphology, collectively known as volume electron microscopy (volume EM), as well as on methods that can be used to localize proteins and antigenic epitopes. Large cell volumes can now be visualized at the EM level by using one of the two complementary imaging techniques, namely Serial Block-face Scanning Electron Microscopy (SB-SEM) or Focused Ion Beam Scanning Electron Microscopy (FIB-SEM). These two block-face imaging methods reveal ultrastructural information from all membrane-bound organelles such as autophagic compartments to be visualized in a three-dimensional space, in association with their surrounding organelles. Another method which falls into the volume EM category is dual-axis electron tomography (ET). This method is more suited to reconstructing smaller volumes from areas of interest that require nano-structural detail to be confirmed such as membrane contact sites (MCSs) between autophagic compartments and various organelles. Further to this, to complement the morphological identification of autophagic compartments, immunolabeling can be carried out at the EM level to confirm the nature of various autophagic compartments depending on the localization of various antigens at a sub-cellular level. To determine this, various immunolabeling techniques can be carried out, namely the pre-embedding or the post-embedding immunolabeling methods. Examples of both of these methods will be described in this chapter. Correlative light-electron microscopy (CLEM) can be used to visualize the same autophagic organelles under the LM, followed by high-resolution imaging under the EM. Finally, cryofixation has revolutionized the EM field by allowing rapid immobilization of cells and

  18. Cellular Stress Responses and Monitored Cellular Activities.

    PubMed

    Sawa, Teiji; Naito, Yoshifumi; Kato, Hideya; Amaya, Fumimasa

    2016-08-01

    To survive, organisms require mechanisms that enable them to sense changes in the outside environment, introduce necessary responses, and resist unfavorable distortion. Consequently, through evolutionary adaptation, cells have become equipped with the apparatus required to monitor their fundamental intracellular processes and the mechanisms needed to try to offset malfunction without receiving any direct signals from the outside environment. It has been shown recently that eukaryotic cells are equipped with a special mechanism that monitors their fundamental cellular functions and that some pathogenic proteobacteria can override this monitoring mechanism to cause harm. The monitored cellular activities involved in the stressed intracellular response have been researched extensively in Caenorhabditis elegans, where discovery of an association between key mitochondrial activities and innate immune responses was named "cellular associated detoxification and defenses (cSADD)." This cellular surveillance pathway (cSADD) oversees core cellular activities such as mitochondrial respiration and protein transport into mitochondria, detects xenobiotics and invading pathogens, and activates the endocrine pathways controlling behavior, detoxification, and immunity. The cSADD pathway is probably associated with cellular responses to stress in human inflammatory diseases. In the critical care field, the pathogenesis of lethal inflammatory syndromes (e.g., respiratory distress syndromes and sepsis) involves the disturbance of mitochondrial respiration leading to cell death. Up-to-date knowledge about monitored cellular activities and cSADD, especially focusing on mitochondrial involvement, can probably help fill a knowledge gap regarding the pathogenesis of lethal inflammatory syndromes in the critical care field. PMID:26954943

  19. Barium cardiotoxicity: Relationship between ultrastructural damage and mechanical effects.

    PubMed

    Delfino, G; Amerini, S; Mugelli, A

    1988-01-01

    The ultrastructural damage in guinea-pig ventricular strips caused by barium was analysed. At a concentration of 1 mmol/litre, barium chloride caused a dramatic increase in the developed tension associated with the onset of automaticity. The ultrastructural analysis demonstrated that barium caused notable and consistent alterations which affected most myocyte components. Various degenerative aspects were observed in mitochondria and in the contractile apparatus. Glycogen deposits were completely depleted. Preparations driven at 4 Hz (i.e. the rate of spontaneous firing of barium-treated preparations) showed moderate ultrastructural alterations, thus demonstrating that the increase in the rate of beating is not the only determinant of the observed damage. These results suggest that the myocardial toxicity of barium is due not only to the well-known modifications in membrane permeability, but possibly also to alterations in cell function. PMID:20702358

  20. The ultrastructure of separated and cultured cell of Porphyra yezoensis

    NASA Astrophysics Data System (ADS)

    Mei, Jun-Xue; Fei, Xiu-Geng

    2001-03-01

    There are many reports that cells (protoplasts) separated from the thallus of Porphyra by enzyme can develop to normal leafy thalli in the same way as monospores. But there are few investigations on the subcellular structure of the isolated vegetative cell for comparison with the subcellular structure of monospores. To clarify whether the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores undergo in their formation and germination, we observed their ultrastructure, compared them with those of the monospore and found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore formation, such as production of small and large fibrous vesicles, but was accompanied by vacuolation and starch mobilization like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.

  1. Ultrastructural changes caused by Snf7 RNAi in larval enterocytes of western corn rootworm (Diabrotica virgifera virgifera Le Conte).

    PubMed

    Koči, Juraj; Ramaseshadri, Parthasarathy; Bolognesi, Renata; Segers, Gerrit; Flannagan, Ronald; Park, Yoonseong

    2014-01-01

    The high sensitivity to oral RNA interference (RNAi) of western corn rootworm (WCR, Diabrotica virgifera virgifera Le Conte) provides a novel tool for pest control. Previous studies have shown that RNAi of DvSnf7, an essential cellular component of endosomal sorting complex required for transport (ESCRT), caused deficiencies in protein de-ubiquitination and autophagy, leading to WCR death. Here we investigated the detailed mechanism leading to larval death by analyzing the ultrastructural changes in midgut enterocytes of WCR treated with double-stranded RNA (ds-DvSnf7). The progressive phases of pathological symptoms caused by DvSnf7-RNAi in enterocytes include: 1) the appearance of irregularly shaped macroautophagic complexes consisting of relatively large lysosomes and multi-lamellar bodies, indicative of failure in autolysosome formation; 2) cell sloughing and loss of apical microvilli, and eventually, 3) massive loss of cellular contents indicating loss of membrane integrity. These data suggest that the critical functions of Snf7 in insect midgut cells demonstrated by the ultrastructural changes in DvSnf7 larval enterocytes underlies the conserved essential function of the ESCRT pathway in autophagy and membrane stability in other organisms. PMID:24409288

  2. Cellular Phone Towers

    MedlinePlus

    ... the call. How are people exposed to the energy from cellular phone towers? As people use cell ... where people can be exposed to them. The energy from a cellular phone tower antenna, like that ...

  3. Ultrastructural alterations induced by two ergosterol biosynthesis inhibitors, ketoconazole and terbinafine, on epimastigotes and amastigotes of Trypanosoma (Schizotrypanum) cruzi.

    PubMed Central

    Lazardi, K; Urbina, J A; de Souza, W

    1990-01-01

    We report the ultrastructural alterations induced during the proliferative stages of Trypanosoma (Schizotrypanum) cruzi, the causative agent of Chagas' disease, by two ergosterol biosynthesis inhibitors, ketoconazole and terbinafine, which had previously been shown to be potent growth inhibitors whose effects are potentiated when used in combination (J. A. Urbina, K. Lazardi, T. Aguirre, M. M. Piras, and R. Piras, Antimicrob. Agents Chemother. 32:1237-1242, 1988). Epimastigotes treated with a low concentration of ketoconazole (1 microM), which blocks ergosterol biosynthesis at the level of C-14 demethylation of lanosterol and induces cell lysis coincident with total ergosterol depletion, showed gross alterations of the kinetoplast-mitochondrion complex, which swelled and lost the organization of its inner membrane and the electron-dense bodies of its matrix. Thus, coincident with the beginning of cell lysis, the kinetoplast-mitochondrion complex occupied greater than 80% of the cell volume, while other subcellular structures such as the nucleus and subpellicular microtubules were not affected. Terbinafine, which blocks ergosterol synthesis in these cells at the level of squalene synthetase and thus leads to almost immediate arrest of growth at concentrations greater than 1 microM, produced proliferation of glycosomelike bodies, binucleated cells (arrest at cytokinesis), and eventually massive vacuolization. When the drugs were combined, the predominant effect was mitochondrial swelling, which was more drastic and took place earlier than that observed in cells treated with ketoconazole alone. In amastigotes proliferating in Vero cells, ketoconazole at the concentration required to eradicate the parasites (10 nM) produced mitochondrial swelling, the appearance of autophagic vacuoles containing partially degraded subcellular material, and finally a general breakdown of the subcellular structures. Terbinafine at 3 microM induced more limited ultrastructural damage to

  4. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-01-01

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young's modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  5. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-12-31

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young`s modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  6. JPRS report. Proliferation issues

    SciTech Connect

    1992-03-26

    This report contains foreign media information on issues related to worldwide proliferation and transfer activities in nuclear, chemical, and biological weapons, including delivery systems and the transfer of weapons-relevant technologies.

  7. Single-prolonged stress induce different change in the cell organelle of the hippocampal cells: A study of ultrastructure.

    PubMed

    Wan, JunLai; Liu, Dongjuan; Zhang, Jie; Shi, Yuxiu; Han, Fang

    2016-01-01

    MRI studies have revealed structural and functional changes in the hippocampus of post-traumatic stress disorder (PTSD) patients. Previous studies conducted by us in a PTSD animal model found that single prolonged stress (SPS) induced abnormal morphological changes in hippocampal cells. The effects of SPS on cellular organelles of the hippocampal neurons remain unknown; however, these changes have been involved in SPS-induced abnormal hippocampal function. The aim of the present study is to examine ultrastructural changes in cellular organelles, including the lysosomes, mitochondria (Mit), Golgi apparatus, and endoplasmic reticulum (ER), following SPS exposure using transmission electron microscopy, enzyme histochemistry, and enzyme cytochemistry. First, morphological changes of the hippocampal cells and ultrastructural changes in cellular organelles, including lysosomes, ER, and Mit-induced by SPS were observed. Results from histo- and cytochemistry demonstrated that the Mit marker enzyme, cytochrome c oxidase (COX), and the lysosomal enzyme acid phosphatase, (ACP), increased following exposure to SPS. SPS induced COX release from Mit and led to a wider distribution of ACP in round lysosomes, NLY, and the Golgi. In addition, we found that SPS increased the presence of autophagosomes and induced changes in the autophagy-related protein, Beclin. These results indicated the differential effects of SPS on cellular organelles, that is, a positive effect on lysosomes as well as a negative effect on the Mit and ER. Increased lysosomal function may serve as protection against SPS-induced cell damage. Structural changes in the Mit and ER may be involved in SPS-induced disorders of energy metabolism and protein synthesis and export. PMID:26589383

  8. Mode of action framework analysis for receptor-mediated toxicity: the Peroxisome Proliferator-Activated Receptor alpha (PPARα) as a case study

    EPA Science Inventory

    Therapeutic hypolipidemic agents and industrial chemicals that cause peroxisome proliferation and induce liver tumors in rodents activate the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα). Research has elucidated the cellular and molecular events by w...

  9. Ultrastructural changes in the rabbit liver induced by carbamate insecticide bendiocarb.

    PubMed

    Holovska, Katarina; Almasiova, Viera; Cigankova, Viera

    2014-01-01

    Carbamates (CB) are used as insecticides and some of them have been registered as human drugs. The mechanism of CB poisoning involves reversible inhibition of acetylcholine esterase. In the present study, we investigated changes in liver ultrastructure in rabbits (Oryctolagus cuniculus) which were administered bendiocarb for 3, 10, 20, and 30 days. Rabbits in all experimental groups received capsules of bendiocarb (96% Bendiocarb, Bayer, Germany) per os daily at a dose of 5 mg/kg of body weight, and after day 11 received the same dose every 48 h. The observed changes were only moderate, focal, and the effect on the liver was not uniform. On the third day of the experiment, injured hepatocytes had dilated bile capillaries with reduced microvilli. There were no visible alterations in the intercellular contacts. Nuclei of these cells were irregular in shape. Many hepatocytes showed considerable increase in the number of peroxisomes. On day 10 of the experiment, the number of peroxisomes was reduced. Other changes, such as dilated rough endoplasmic reticulum and proliferation of smooth endoplasmic reticulum were observed on day 20. The number of lipid droplets in hepatocytes gradually increased. Usually they were present in low numbers, but on day 30 of the experiment their number increased significantly. They coalesced and formed a single lipid droplet which changed the shape of the nuclei. The results presented in this study indicate that both short and long-term administration of bendiocarb affects the liver ultrastructure. At the same time we also observed rapid onset of regeneration of the damaged tissue through activation of hepatocytes and oval cells. PMID:24901965

  10. A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

    NASA Astrophysics Data System (ADS)

    Stepanova, Olga; Rybalchenko, Oksana; Astafiev, Alexander; Orlova, Olga; Kudryavtsev, Anatoly; Kapustina, Valentina

    2016-08-01

    The morphology of bacterial cells and biofilms subjected to a low frequency (˜105 Hz) ac (˜10-1 A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

  11. Regulation of cellular chromatin state

    PubMed Central

    Mishra, Rakesh K; Dhawan, Jyotsna

    2010-01-01

    The identity and functionality of eukaryotic cells is defined not just by their genomic sequence which remains constant between cell types, but by their gene expression profiles governed by epigenetic mechanisms. Epigenetic controls maintain and change the chromatin state throughout development, as exemplified by the setting up of cellular memory for the regulation and maintenance of homeotic genes in proliferating progenitors during embryonic development. Higher order chromatin structure in reversibly arrested adult stem cells also involves epigenetic regulation and in this review we highlight common trends governing chromatin states, focusing on quiescence and differentiation during myogenesis. Together, these diverse developmental modules reveal the dynamic nature of chromatin regulation providing fresh insights into the role of epigenetic mechanisms in potentiating development and differentiation. PMID:20592864

  12. Scaffold architecture and fibrin gels promote meniscal cell proliferation

    SciTech Connect

    Pawelec, K. M. E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E.; Wardale, R. J. E-mail: jw626@cam.ac.uk

    2015-01-01

    Stability of the knee relies on the meniscus, a complex connective tissue with poor healing ability. Current meniscal tissue engineering is inadequate, as the signals for increasing meniscal cell proliferation have not been established. In this study, collagen scaffold structure, isotropic or aligned, and fibrin gel addition were tested. Metabolic activity was promoted by fibrin addition. Cellular proliferation, however, was significantly increased by both aligned architectures and fibrin addition. None of the constructs impaired collagen type I production or triggered adverse inflammatory responses. It was demonstrated that both fibrin gel addition and optimized scaffold architecture effectively promote meniscal cell proliferation.

  13. Cellular Localization of Simian Immunodeficiency Virus in Lymphoid Tissues

    PubMed Central

    Ringler, D. J.; Wyand, M. S.; Walsh, D. G.; MacKey, J. J.; Chalifoux, L. V.; Popovic, M.; Minassian, A. A.; Sehgal, P. K.; Daniel, M. D.; Desrosiers, R. C.; King, N. W.

    1989-01-01

    Simian immunodeficiency virus (SIV) is a lentivirus with genetic relatedness to the human immunodeficiency viruses (HIV-1 and HIV-2). It induces a fatal syndrome in rhesus monkeys that closely parallels the clinical course of AIDS in humans. The authors used double-labeling immunohistochemical procedures on rhesus lymph node and spleen taken during different time periods after SIV infection to localize the p27 gag protein to specific cellular immunophenotypes. In animals with follicular hyperplasia, viral protein was found associated predominantly with follicular dendritic cells. Many of these cells showed ultrastructural alterations consisting of swollen dendritic processes contaning electron-dense material. Lentiviral particles were found associated with this cell type only rarely. In lymphoid tissues with other histopathologic changes, macrophages and multinucleate giant cells were the predominant cell types containing detectable quantities of viral protein; smaller numbers of p27+ lymhocytes were present. Ultrastructurally, viral particles were found within the extracellular spce adjacent to tissue macrophages and within membrane-bound vacuoles of giant cells and tissue macrophage. These results show that certain histologic patterns seen during the course of infection correlate with the localization of viral antigen to specific cellular immunophenotypes and that during the disease course, viral protein is preferentially localized in sections of lymphonode and spleen to cells of the macrophage and dendritic cell lineage. ImagesFigure 1Figure 2Figure 3A, B PMID:2537016

  14. Ultrastructural changes in sweet orange with symptoms of huanglongbing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus greening (Huanglongbing [HLB]) is one of the most destructive citrus diseases worldwide. To better understand the ultrastructural changes of sweet orange seedlings in response to infection, anatomical analyses of HLB-infected sweet orange were carried out by light and electron microscopy. A...

  15. Improved ultrastructure of marine invertebrates using non-toxic buffers

    PubMed Central

    Montanaro, Jacqueline; Gruber, Daniela

    2016-01-01

    Many marine biology studies depend on field work on ships or remote sampling locations where sophisticated sample preservation techniques (e.g., high-pressure freezing) are often limited or unavailable. Our aim was to optimize the ultrastructural preservation of marine invertebrates, especially when working in the field. To achieve chemically-fixed material of the highest quality, we compared the resulting ultrastructure of gill tissue of the mussel Mytilus edulis when fixed with differently buffered EM fixatives for marine specimens (seawater, cacodylate and phosphate buffer) and a new fixative formulation with the non-toxic PHEM buffer (PIPES, HEPES, EGTA and MgCl2). All buffers were adapted for immersion fixation to form an isotonic fixative in combination with 2.5% glutaraldehyde. We showed that PHEM buffer based fixatives resulted in equal or better ultrastructure preservation when directly compared to routine standard fixatives. These results were also reproducible when extending the PHEM buffered fixative to the fixation of additional different marine invertebrate species, which also displayed excellent ultrastructural detail. We highly recommend the usage of PHEM-buffered fixation for the fixation of marine invertebrates. PMID:27069800

  16. Tissue section AFM: In situ ultrastructural imaging of native biomolecules

    PubMed Central

    Graham, Helen K.; Hodson, Nigel W.; Hoyland, Judith A.; Millward-Sadler, Sarah J.; Garrod, David; Scothern, Anthea; Griffiths, Christopher E.M.; Watson, Rachel E.B.; Cox, Thomas R.; Erler, Janine T.; Trafford, Andrew W.; Sherratt, Michael J.

    2010-01-01

    Conventional approaches for ultrastructural high-resolution imaging of biological specimens induce profound changes in bio-molecular structures. By combining tissue cryo-sectioning with non-destructive atomic force microscopy (AFM) imaging we have developed a methodology that may be applied by the non-specialist to both preserve and visualize bio-molecular structures (in particular extracellular matrix assemblies) in situ. This tissue section AFM technique is capable of: i) resolving nm–µm scale features of intra- and extracellular structures in tissue cryo-sections; ii) imaging the same tissue region before and after experimental interventions; iii) combining ultrastructural imaging with complimentary microscopical and micromechanical methods. Here, we employ this technique to: i) visualize the macro-molecular structures of unstained and unfixed fibrillar collagens (in skin, cartilage and intervertebral disc), elastic fibres (in aorta and lung), desmosomes (in nasal epithelium) and mitochondria (in heart); ii) quantify the ultrastructural effects of sequential collagenase digestion on a single elastic fibre; iii) correlate optical (auto fluorescent) with ultrastructural (AFM) images of aortic elastic lamellae. PMID:20144712

  17. Ultrastructure of Placenta of Gravidas with Gestational Diabetes Mellitus

    PubMed Central

    Meng, Qian; Shao, Li; Luo, Xiucui; Mu, Yingping; Xu, Wen; Gao, Chao; Gao, Li; Liu, Jiayin; Cui, Yugui

    2015-01-01

    Objectives. Gestational diabetes mellitus (GDM) leads to an abnormal placental environment which may cause some structural alterations of placenta and affect placental development and function. In this study, the ultrastructural appearances of term placentas from women with GDM and normal pregnancy were meticulously compared. Materials and Methods. The placenta tissues of term birth from 10 women with GDM and 10 women with normal pregnancy were applied with the signed informed consent. The morphology of fetomaternal interface of placenta was examined using light microscopy (LM) and transmission electron microscopy (TEM). Results. On LM, the following morphological changes in villous tissues were found in the GDM placentas when compared with the control placentas: edematous stroma, apparent increase in the number of syncytial knots, and perivillous fibrin deposition. On TEM, the distinct ultrastructural alterations indicating the degeneration of terminal villi were found in the GDM placentas as follows: thickening of the basal membrane (BM) of vasculosyncytial membrane (VSM) and the VSM itself, significantly fewer or even absent syncytiotrophoblastic microvilli, swollen or completely destroyed mitochondria and endoplasmic reticulum, and syncytiotrophoblasts with multiple vacuoles. Conclusion. Ultrastructural differences exist between GDM and control placentas. The differences of placenta ultrastructure are likely responsible for the impairment of placental barrier and function in GDM. PMID:26379710

  18. Correlative microscopy for phylogenetic and ultrastructural characterization of microbial communities

    PubMed Central

    Knierim, Bernhard; Luef, Birgit; Wilmes, Paul; Webb, Richard I.; Auer, Manfred; Comolli, Luis R.; Banfield, Jillian F.

    2014-01-01

    Transmission electron microscopy (TEM) can provide ultrastructural information for cells in microbial community samples and phylogenetic information can be recovered via molecular surveys. Here we report an approach to link these datasets by coupling fluorescence in situ hybridization (FISH) with either conventional biological or cryogenic TEM. The method could revolutionize understanding of the organization and functioning of microbial communities in natural systems. PMID:23757227

  19. Hypertextual Ultrastructures: Movement and Containment in Texts and Hypertexts

    ERIC Educational Resources Information Center

    Coste, Rosemarie L.

    2009-01-01

    The surface-level experience of hypertextuality as formless and unbounded, blurring boundaries among texts and between readers and writers, is created by a deep structure which is not normally presented to readers and which, like the ultrastructure of living cells, defines and controls texts' nature and functions. Most readers, restricted to…

  20. Ultrastructure study of apple meristem cells during cryopreservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ultrastructure of apple (Malus x domestica Borkh.) meristem cells was studied before and after cold acclimation (CA) and during the steps of PVS2 vitrification. We compared cells of in vitro grown shoots of two cultivars, Grushovka Vernenskaya and Voskhod. Cells of the two cultivars were simila...

  1. Improved ultrastructure of marine invertebrates using non-toxic buffers.

    PubMed

    Montanaro, Jacqueline; Gruber, Daniela; Leisch, Nikolaus

    2016-01-01

    Many marine biology studies depend on field work on ships or remote sampling locations where sophisticated sample preservation techniques (e.g., high-pressure freezing) are often limited or unavailable. Our aim was to optimize the ultrastructural preservation of marine invertebrates, especially when working in the field. To achieve chemically-fixed material of the highest quality, we compared the resulting ultrastructure of gill tissue of the mussel Mytilus edulis when fixed with differently buffered EM fixatives for marine specimens (seawater, cacodylate and phosphate buffer) and a new fixative formulation with the non-toxic PHEM buffer (PIPES, HEPES, EGTA and MgCl2). All buffers were adapted for immersion fixation to form an isotonic fixative in combination with 2.5% glutaraldehyde. We showed that PHEM buffer based fixatives resulted in equal or better ultrastructure preservation when directly compared to routine standard fixatives. These results were also reproducible when extending the PHEM buffered fixative to the fixation of additional different marine invertebrate species, which also displayed excellent ultrastructural detail. We highly recommend the usage of PHEM-buffered fixation for the fixation of marine invertebrates. PMID:27069800

  2. Cadmium-induced ultrastructural changes in Euglena cells

    SciTech Connect

    Duret, S.; Bonaly, J.; Bariaud, A.; Vannereau, A.; Mestre, J.C.

    1986-02-01

    The ultrastructure of Euglena gracilis grown in the presence of Cd showed only numerous myelin-like structures in mitochondria, chloroplasts altered in shape, and thylakoid arrangement and increase of osmiophilic plastoglobuli. These alterations indicate that respiratory processes are the initial target of Cd toxicity.

  3. Ultrastructure Study of Apple Meristem Cells During Cryopreservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ultrastructure of apple (Malus x domestica Borkh.) meristem cells was studied before and after cold acclimation (CA) and during the steps of PVS2 vitrification. We compared cells of in vitro grown shoots of two cultivars, Grushovka Vernenskaya and Voskhod. Cells of the two cultivars were simila...

  4. Echinococcus multilocularis Leuckart, 1863 (Taeniidae): new data on sperm ultrastructure.

    PubMed

    Miquel, Jordi; Świderski, Zdzisław; Azzouz-Maache, Samira; Pétavy, Anne-Françoise

    2016-06-01

    The present study establishes the ultrastructural organisation of the mature spermatozoon of Echinococcus multilocularis, which is essential for future research on the location of specific proteins involved in the sperm development in this species and also in Echinococcus granulosus. Thus, the ultrastructural characteristics of the sperm cell are described by means of transmission electron microscopy. The spermatozoon of E. multilocularis is a filiform cell, which is tapered at both extremities and lacks mitochondria. It exhibits all the characteristics of type VII spermatozoon of tapeworms, namely a single axoneme, crested bodies, spiralled cortical microtubules and nucleus, a periaxonemal sheath and intracytoplasmic walls. Other characteristics observed in the male gamete are the presence of a >900-nm long apical cone in its anterior extremity and only the axoneme in its posterior extremity. The ultrastructural characters of the spermatozoon of E. multilocularis are compared with those of other cestodes studied to date, with particular emphasis on representatives of the genus Taenia. The most interesting finding concerns the presence of two helical crested bodies in E. multilocularis while in the studied species of Taenia, there is only one crested body. Future ultrastructural studies of other species of the genus Echinococcus would be of particular interest in order to confirm whether or not the presence of two crested bodies is a characteristic of this genus. PMID:26960958

  5. Molecular and Ultrastructural Properties of Maize White Line Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports the complete nucleotide sequence of the genome of Maize white line mosaic virus (MWLMV) and describes the ultrastructural features of infected maize cells. The viral genome is an RNA molecule 4293 nt in size with the same structural organization of members of the Aureusvirus and ...

  6. Ultrastructural maturation of human bone marrow mesenchymal stem cells-derived cardiomyocytes under alternative induction of 5-azacytidine.

    PubMed

    Piryaei, Abbas; Soleimani, Masoud; Heidari, Mohammad Hassan; Saheli, Mona; Rohani, Razieh; Almasieh, Mohammadali

    2015-05-01

    Adult cardiomyocytes lack the ability to proliferate and are unable to repair damaged heart tissue, therefore differentiation of stem cells to cardiomyocytes represents an exceptional opportunity to study cardiomyocytes in vitro and potentially provides a valuable source for replacing damaged tissue. However, characteristic maturity of the in vitro differentiated cardiomyocytes and methods to achieve it are yet to be optimized. In this study, differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs) into cardiomyocytes is accomplished and the process investigated ultrastructurally. The hBM-MSCs were alternatively treated with 5 μM of 5-azacytidine (5-aza) for 8 weeks resulting in differentiation to cardiomyocytes. Expressions of cardiomyocyte-specific genes [cardiac α-actinin, cardiac β-myosin heavy chain (MHC) and connexin-43] and proteins (cardiac α-actinin, cardiac troponin and connexin-43) were confirmed in a time-dependent manner from the first to the fifth weeks post-induction. Ultrastructural maturation of hBM-MSCs-derived cardiomyocyte (MSCs-CM) corresponded with increase in number and organization of myofilaments in cells over time. Starting from week five, organized myofibrils along with developing sarcomeres were detectable. Later on, MSCs-CM were characterized by the presence of sarcoplasmic reticulum, T-tubules and diads as cardiomyocytes connected to each other by intercalated disc-like structures. Here, we showed the potential of hBM-MSCs as a source for the production of cardiomyocytes and confirmed mature ultrastructural characteristics of these cells using our alternative incubation method. PMID:25573851

  7. Tracheomalacia in a neonate with kniest dysplasia: histopathologic and ultrastructural features.

    PubMed

    Hicks, J; De Jong, A; Barrish, J; Zhu, S H; Popek, E

    2001-01-01

    Kniest dysplasia is an autosomal-dominant chondrodysplastic condition characterized by disproportionate dwarfism, short trunk, small pelvis, kyphoscoliosis, short limbs, prominent joints, premature osteoarthritis, and craniofacial manifestations. The craniofacial abnormalities include tracheomalacia, midface hypoplasia, cleft palate, early onset myopia, retinal detachment, prominent eyes, and sensorineural hearing loss. Radiologic features include dumbbell-shaped femora, platyspondylia with anterior wedging of vertebral bodies, coronal clefts of thoracolumbar vertebral bodies, low broad ilia, and short tubular bones with broad metaphyses and deformed large epiphyses. This form of chondrodysplasia is associated with mutations in type II collagen splicing sequences. Mutations have been identified in the COL2A1 (type II collagen) gene between exons 12 and 24. Type II collagen is the predominant structural protein in cartilage, and mutations in this collagen account for the Kniest dysplasia phenotype. Histopathologic and ultrastructural features of epiphyseal plate cartilage have been described, but tracheal cartilage in an affected neonate has not been examined. The authors report the histopathologic and ultrastructural findings of anterior tracheal cartilage from a 35-day-old female with suspected chondrodysplasia who had tracheomalacia with airway obstruction. The tracheal cartilage was moderately cellular, but lacked cystic and myxoid changes in its matrix. The chondrocytes had abundant cytoplasmic PAS-positive inclusions. Some of these inclusions were diastase-resistant and were also highlighted on Alcian blue staining. Ultrastructural examination revealed chondrocytes with greatly dilated rough endoplasmic reticulum containing granular proteinaceous material. There were also frequent aggregates of typical glycogen. The defect in the COL2A1 gene is secondary to mutations, especially at splice junctions, and this markedly disrupts triple helix formation. The

  8. Ultrastructural and Associated Studies on Experimental Mastitis in the Mouse Produced by Three Strains of Streptococcus

    PubMed Central

    Chandler, R. L.

    1973-01-01

    Ultrastructural studies were made on mastitis produced experimentally in the mouse by 3 different strains of streptococcus. The first strain of Str. agalactiae produced cellular changes detectable by electron microscopy as early as 6 hours after inoculation and at 48 hours alterations to secretory epithelium, lumenal contents and subepithelial tissue were very evident; later samplings showed more advanced changes. Cocci were seen in the lumens and within secretory cells; at later stages they showed degenerative changes themselves. A second strain of Str. agalactiae produced similar general changes; milk protein masses were common in the lumens, and rod-shaped crystals were observed. Cocci were seen free in the lumens, in lumenal macrophages, within secretory cells and, in later stages, in the subepithelial tissue. The possibility of their penetrating the epithelium either through the epithelial cell substance or through the intercellular space is discussed. Studies with a strain of Str. uberis indicated a lower level of pathogenicity but electron microscopy showed a variety of cellular changes. It was clear from comparative studies, including the use of heat-killed cocci, that very large numbers of bacteria must be present in a given specimen for their identification in ultrathin sections of mammary gland. ImagesFigs. 5-8Figs. 1-4 PMID:4736957

  9. Effects of a 2X gravity environment on the ultrastructure of the gerbil parathyroid gland

    NASA Technical Reports Server (NTRS)

    Sannes, P. L.; Hayes, T. G.

    1975-01-01

    A number of studies concerning the effects of hypergravity on bone have shown increases in bone mass or bone dimensions. Correlative studies, which could provide clues to the mechanism for such a response, have been lacking. The purpose of the present study was to evaluate the ultrastructure of parathyroid glands of Mongolian gerbils exposed to a continuous 2 X gravity force for 60 d. It was found that the experimental animals had parathyroid glands which had a greater percentage of chief cells in the active stage of their secretory cycle when compared with control animals. This result was interpreted to indicate an increase in parathyroid gland secretory activity and, hence, an increase in parathyroid hormone release. It was suggested that increased parathyroid secretory activity was necessary to maintain serum calcium levels of hypergravity animals within normal limits. Cellular forms resembling water clear cells and highly compact, degenerating cells were described in experimental animals but not in controls. Areas suggestive of cellular dissolution and disorganization were also reported in experimental parathyroids.

  10. Electrospun type 1 collagen matrices preserving native ultrastructure using benign binary solvent for cardiac tissue engineering.

    PubMed

    Elamparithi, Anuradha; Punnoose, Alan M; Kuruvilla, Sarah

    2016-08-01

    Electrospinning is a well-established technique that uses a high electric field to fabricate ultrafine fibrous scaffolds from both natural and synthetic polymers to mimic the cellular microenvironment. Collagen is one of the most preferred biopolymers, due to its widespread occurrence in nature and its biocompatibility. Electrospinning of collagen alone has been reported, with fluoroalcohols such as hexafluoroisopropanol (HFIP) and trifluoroethanol (TFE), but the resultant collagen lost its characteristic ultrastructural integrity of D-periodicity 67 nm banding, confirmed by transmission electron microscopy (TEM), and the fluoroalcohols used were toxic to the environment. In this study, we describe the use of glacial acetic acid and DMSO to dissolve collagen and generate electrospun nanofibers of collagen type 1, which is non-toxic and economical. TEM analysis revealed the characteristic feature of native collagen triple helical repeats, showing 67 nm D-periodicity banding pattern and confirming that the ultrastructural integrity of the collagen was maintained. Analysis by scanning electron microscopy (SEM) showed fiber diameters in the range of 200-1100 nm. Biocompatibility of the three-dimensional (3D) scaffolds was established by MTT assays using rat skeletal myoblasts (L6 cell line) and confocal microscopic analysis of immunofluorescent-stained sections of collagen scaffolds for muscle-specific markers such as desmin and actin. Primary neonatal rat ventricular cardiomyocytes (NRVCM) seeded onto the collagen scaffolds were able to maintain their contractile function for a period of 17 days and also expressed higher levels of desmin when compared with 2D cultures. We report for the first time that collagen type 1 can be electrospun without blending with copolymers using the novel benign solvent combination, and the method can be potentially explored for applications in tissue engineering. PMID:25960178

  11. Lithium-induced changes in gravicurvature, statocyte ultrastructure and calcium balance of pea roots

    NASA Astrophysics Data System (ADS)

    Belyavskaya, N. A.

    Calcium signaling has been implicated in plant graviperception. In order to investigate the role of intracellular calcium in the process, I used lithium ions (LiCl), which suppress inositol 1,4,5-trisphosphate (IP3) cycling and signaling by inhibiting inositol-1-phosphatase. After 4 h of gravistimulation, no curvature was observed in 81% of the roots of 5-day Pisum sativum seedlings pretreated with 5 mM LiCl. Structural features of statocyte ultrastructure in these roots were the following: loss of a cellular polarity, appearance of amyloplast clusters, condensed mitochondria, local dilations in a perinuclear space, increases in a relative volume of vacuoles. The intensity of a cytochemical reaction (pyroantimonate staining which detected Ca2+ ions) was moderate: the Ca2+ pyroantimonate deposits were observed in all organelles. There were few granules of this precipitate in a hyaloplasm of the statocytes. Mitochondria and vacuoles were found to contain more granules of the precipitate compared with the controls. Additionally, Ca2+-ATPase activity in the statocytes of pea roots pretreated with LiCl was approximately the same as in control roots. Data obtained by using inhibitor of inositol signaling suggest that the observed effects of LiCl on root gravicurvature and ultrastructure of root statocytes were due to effects on Ca2+ homeostasis, particularly on IP3-mediated release of intracellular Ca2+ which can be inhibited by inositol depletion. The work demonstrates the key role played by second messengers (Ca2+ and IP3) in a gravity perception and response.

  12. Species-specific ultrastructure of neuronal lipofuscin in hippocampus and neocortex of subhuman mammals and humans.

    PubMed

    Boellaard, J W; Schlote, W; Hofer, W

    2004-01-01

    Lipofuscin represents an integral part of neurons and glial cells in mammals and in submammalian species. It is a special lysosomal organelle, takes part of cellular metabolism, and is a structural expression of catabolic pathways. Species-specific differences of lipofuscin indicate metabolic differences of the relevant neurons. The authors have studied the ultrastructure of neuronal lipofuscin in the hippocampus and cerebral neocortex of dogs, horses, cows, elephants, rats, mice, apes, and humans to answer the question of species-specific differences of this organelle. Paraffin sections of formalin-fixed material were investigated by hematoxylin-eosin and PAS staining, by fluorescence microscopy for autofluorescence, with a laser scanning confocal microscope and by electron microscopy. In the animals studied and in humans the lipofuscin displayed, in addition to the general trilaminar substructure, species-specific appearances. No differences were found in the lipofuscin structure between neocortical and hippocampal neurons of the separate animal species. In contrast, in humans, neurons of the hippocampus showed a particular lipofuscin structure, not only different from the neocortical one, but also with differences between CA1 and CA3/4 sectors. Interestingly, in apes a transitional situation was found with slight differences between neocortical and hippocampal lipofuscin, especially in the rhesus monkey. This peculiarity was corroborated by the distribution of special pentilaminar linear structures in the lipofuscin pigment in all animals, only sparsely in the rhesus monkey and not in humans. The results indicate that lipofuscin ultrastructure of neocortical and hippocampal neurons is species specific and that lipofuscin in the human hippocampal neurons displays structures characteristic of man differing from the neocortical neuronal lipofuscin. The neuronal lipofuscin of apes, especially of the rhesus monkey displays structures in between humans and lower

  13. Ultrastructure damage of oviduct telocytes in rat model of acute salpingitis

    PubMed Central

    Yang, Jian; Chi, Chi; Liu, Zhen; Yang, Gang; Shen, Zong-Ji; Yang, Xiao-Jun

    2015-01-01

    Acute salpingitis (AS) is an inflammatory disease which causes severe damage to a subset of classically described cells lining in oviduct wall and contributes to interstitial fibrosis and fertility problems. Telocytes (TCs), a newly discovered peculiar type of stromal cells, have been identified in many organs, including oviduct, with proposed multiple potential bio-functions. However, with recent increasing reports regarding TCs alterations in disease-affected tissues, there is still lack of evidence about TCs involvement in AS-affected oviduct tissues and potential pathophysiological roles. We presently identified normal TCs by their characteristic ultrastructural features and immunophenotype. However, in AS-affected oviduct tissues, TCs displayed multiple ultrastructural damage both in cellular body and prolongations, with obvious loss of TCs and development of tissue fibrosis. Furthermore, TCs lose their interstitial 3-D network connected by homocellular or heterocellular junctions between TCs and adjacent cells. And especially, TCs connected to the activated immunocytes (mononuclear cells, eosinophils) and affected local immune state (repression or activation). Meanwhile, massive neutrophils infiltration and overproduced Inducible Nitric Oxide Synthase (iNOS), COX-2, suggested mechanism of inflammatory-induced TCs damage. Consequently, TCs damage might contribute to AS-induced structural and reproductive functional abnormalities of oviduct, probably via: (i) substances, energy and functional insufficiency, presumably, e.g. TC-specific genetic material profiles, ion channels, cytoskeletal elements, Tps dynamics, etc., (ii) impaired TCs-mediated multicellular signalling, such as homeostasis/angiogenesis, tissue repair/regeneration, neurotransmission, (iii) derangement of 3-D network and impaired mechanical support for TCs-mediated multicellular signals within the stromal compartment, consequently induced interstitial fibrosis, (iv) involvement in local

  14. Functional canine dendritic cells can be generated in vitro from peripheral blood mononuclear cells and contain a cytoplasmic ultrastructural marker.

    PubMed

    Ibisch, C; Pradal, G; Bach, J M; Lieubeau, B

    2005-03-01

    For physiological and practical reasons the dog is a large animal model used increasingly to study the pathogenesis of human diseases and new therapeutic approaches, in particular for immune disorders. However, some immunological resources are lacking in this model, especially concerning dendritic cells. The aim of our study was to develop an efficient method to generate dendritic cells (DC) in vitro from dog peripheral blood mononuclear cells (PBMC) and to characterize their functional, structural and ultrastructural properties. PBMC were cultured in vitro with IL-4 and GM-CSF. After 1 week of culture, a great proportion of non-adherent cells displayed typical cytoplasmic processes, as evidenced both by optical and electron microscopy. Cytometric analysis revealed the presence of 41.7+/-24.6% CD14+ cells expressing both CD11c and MHC class II molecules. Allogeneic mixed lymphocyte reactions confirmed the ability of these cultures to stimulate the proliferation of allogeneic lymphocytes as already reported as a characteristic of DC in other species. In addition, we describe for the first time the presence in canine DC of cytoplasmic periodic microstructures (PMS) that could represent ultrastructural markers of canine DC. In conclusion, our study provides an easy method to generate DC from PBMC in sufficient numbers for immunological in vitro investigations in dogs, a pre-clinical model for many human diseases. PMID:15847807

  15. Discoidin domain receptor 2 (DDR2) regulates proliferation of endochondral cells in mice

    SciTech Connect

    Kawai, Ikuma; Hisaki, Tomoka; Sugiura, Koji; Naito, Kunihiko; Kano, Kiyoshi

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase. Black-Right-Pointing-Pointer DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. Black-Right-Pointing-Pointer We produced in vitro and in vivo model to better understand the role of DDR2. Black-Right-Pointing-Pointer DDR2 might play an inhibitory role in the proliferation of chondrocyte. -- Abstract: Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase that is activated by fibrillar collagens. DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. The decrement of endogenous DDR2 represses osteoblastic marker gene expression and osteogenic differentiation in murine preosteoblastic cells, but the functions of DDR2 in chondrogenic cellular proliferation remain unclear. To better understand the role of DDR2 signaling in cellular proliferation in endochondral ossification, we inhibited Ddr2 expression via the inhibitory effect of miRNA on Ddr2 mRNA (miDdr2) and analyzed the cellular proliferation and differentiation in the prechondrocyte ATDC5 cell lines. To investigate DDR2's molecular role in endochondral cellular proliferation in vivo, we also produced transgenic mice in which the expression of truncated, kinase dead (KD) DDR2 protein is induced, and evaluated the DDR2 function in cellular proliferation in chondrocytes. Although the miDdr2-transfected ATDC5 cell lines retained normal differentiation ability, DDR2 reduction finally promoted cellular proliferation in proportion to the decreasing ratio of Ddr2 expression, and it also promoted earlier differentiation to cartilage cells by insulin induction. The layer of hypertrophic chondrocytes in KD Ddr2 transgenic mice was not significantly thicker than that of normal littermates, but the layer of proliferative chondrocytes in KD-Ddr2 transgenic mice was significantly thicker than that of normal littermates

  16. Alterations of ultrastructure and elemental composition in cultured neonatal rat cardiac myocytes after metabolic inhibition with iodoacetic acid.

    PubMed

    Buja, L M; Hagler, H K; Parsons, D; Chien, K; Reynolds, R C; Willerson, J T

    1985-10-01

    The purpose of this study was to document changes in cellular fine structure and elemental composition, and their relationship to progression of cell injury, in cultured neonatal rat cardiac myocytes in which impaired energy metabolism was produced by the metabolic inhibitor, iodoacetic acid (IAA). In order to quantitate changes in the concentrations of elements and their subcellular distribution in individual myocytes, electron probe x-ray microanalysis was performed on freeze-dried cryosections of rapidly frozen cells. After 1 hour of exposure to IAA, ATP level was not significantly reduced. Most cells exhibited minimal ultrastructural alterations and had normal elemental profiles, whereas some cells (10 to 25%) had increased sodium and calcium in mitochondria and cytoplasm. After exposure to IAA for 1.5, 2, or 4 hours, the ATP level was reduced to below one third of control, and remained decreased 24 hours after removal of IAA, indicating irreversible depression of this variable. After exposure to IAA for 1.5 hours no longer, many cells showed severe ultrastructural alterations, including contraction or swelling of mitochondria and distortion of the cristae, myofibrillar hypercontraction, and formation of fluid-filled blebs. At 1.5 and 2 hours, approximately 75% or more of the myocytes had increased sodium and calcium and decreased potassium and magnesium in mitochondria, nuclei, and cytoplasm. Thus, the development of an increased calcium concentration in cytoplasm as well as mitochondria of most myocytes was a feature of this transitional period. These data indicate that progressive alterations in the levels and distribution of elements accompany the development of severe ultrastructural changes and irreversible injury in response to impaired energy metabolism in cultured myocytes. These elemental alterations include accumulation of calcium in cytoplasm and mitochondria of myocytes in this model. PMID:2413276

  17. Odd-skipped related 2 regulates genes related to proliferation and development

    SciTech Connect

    Kawai, Shinji; Abiko, Yoshimitsu; Amano, Atsuo

    2010-07-23

    Cell proliferation is a biological process in which chromosomes replicate in one cell and equally divide into two daughter cells. Our previous findings suggested that Odd-skipped related 2 (Osr2) plays an important role in cellular quiescence and proliferation under epigenetic regulation. However, the mechanism used by Osr2 to establish and maintain proliferation is unknown. To examine the functional role of Osr2 in cell proliferation, we analyzed its downstream target genes using microarray analysis following adenovirus-induced overexpression of Osr2 as well as knockdown with Osr2 siRNA, which showed that Osr2 regulates a multitude of genes involved in proliferation and the cell cycle, as well as development. Additional proliferation assays also indicated that Osr2 likely functions to elicit cell proliferation. Together, these results suggest that Osr2 plays important roles in proliferation and development.

  18. Suppression of splenic lymphocyte proliferation by Eucommia ulmoides and genipin.

    PubMed

    Yang, Gabsik; Kyoung Seo, Eun; Lee, Je-Hyun; Young Lee, Joo

    2015-04-01

    We investigated the modulation of innate and adaptive immune cell activation by Eucommia ulmoides Oliver extract (EUE) and its ingredient genipin. As an innate immunity indicator, the phagocytic activity of macrophages was determined by measuring engulfed, fluorescently labeled Escherichia coli. As a surrogate marker for the respective activation of cellular and humoral adaptive immunity, concanavalin A (Con A) and lipopolysaccharide (LPS) induction of primary splenocyte proliferation was assayed in in vitro and ex vivo systems. EUE and genipin suppressed the proliferation of primary splenic lymphocytes induced by Con A or LPS, but not macrophage phagocytosis. Oral administration of EUE and genipin to mice decreased splenic lymphocyte proliferation induced by Con A or LPS. These results revealed that E. ulmoides and genipin suppressed cellular and humoral adaptive immunity, and they suggest that E. ulmoides and genipin are promising candidates for immunosuppressive drugs that target diseases that involve excessive activation of adaptive immunity. PMID:25879499

  19. Proliferation: Threat and response

    SciTech Connect

    1996-04-01

    ;Table of Contents: Section I: The Regional Proliferation Challenge; Northeast Asia; The Middle East and North Africa; The Former Soviet Union: Russia, Ukrane, Kazakstan, And Belarus; South Asia; The International Threat: Dangers from Terrorism, Insurgencies, Civil Wars, And Organized Crime; Section II: Department of Defense Response; Technical Annex: Accessible Technologies; Glossary.

  20. JPRS report proliferation issues

    SciTech Connect

    1991-11-18

    This report contains foreign media information on issues related to worldwide proliferation and transfer activities in nuclear, chemical, and biological weapons, including delivery systems and the transfer of weapons relevant technologies. The following locations are included: (1) China; (2) Indonesia; (3) Bulgaria; (4) Brazil, Cuba; (5) Egypt, India, Iran, Iraq, Israel, Pakistan; (6) Soviet Union; and (7) France, Germany, United Kingdom, Italy, Norway.

  1. Cell Proliferation in Neuroblastoma.

    PubMed

    Stafman, Laura L; Beierle, Elizabeth A

    2016-01-01

    Neuroblastoma, the most common extracranial solid tumor of childhood, continues to carry a dismal prognosis for children diagnosed with advanced stage or relapsed disease. This review focuses upon factors responsible for cell proliferation in neuroblastoma including transcription factors, kinases, and regulators of the cell cycle. Novel therapeutic strategies directed toward these targets in neuroblastoma are discussed. PMID:26771642

  2. Controlling nuclear proliferation

    SciTech Connect

    Sweet, W.

    1981-07-17

    Nuclear non-proliferation policy depends on the 1968 Non-Proliferation Treaty, in which countries promise not to acquire nuclear weapons in exchange for open access to peaceful nuclear technology, and a system of international safeguards that are imposed on exported nuclear equipment and facilities operated by parties to the treaty. Critics have feared all along that non-nuclear countries might circumvent or exploit the system to obtain nuclear weapons and that the Atoms for Peace plan would spread the very technology it sought to control. The nuclear weapons states would like everyone else to believe that atomic bombs are undesirable, but they continue to rely on the bombs for their own defense. Israel's raid on Iraq's nuclear reactor focused world attention on the proliferation problem and helped to broaden and sterengthen its prospects. It also highlighted the weakness that there are no effective sanctions against violators. Until the international community can ageee on enforcement measures powerful enough to prevent nuclear proliferation, individual countries may be tempted to follow Israel's example, 19 references.

  3. Cell Proliferation in Neuroblastoma

    PubMed Central

    Stafman, Laura L.; Beierle, Elizabeth A.

    2016-01-01

    Neuroblastoma, the most common extracranial solid tumor of childhood, continues to carry a dismal prognosis for children diagnosed with advanced stage or relapsed disease. This review focuses upon factors responsible for cell proliferation in neuroblastoma including transcription factors, kinases, and regulators of the cell cycle. Novel therapeutic strategies directed toward these targets in neuroblastoma are discussed. PMID:26771642

  4. Modelling cellular behaviour

    NASA Astrophysics Data System (ADS)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  5. Resveratrol Protects Chondrocytes from Apoptosis via Altering the Ultrastructural and Biomechanical Properties: An AFM Study

    PubMed Central

    Chen, Tongsheng; Wang, Xiaoping

    2014-01-01

    Osteoarthritis (OA), a degenerative joint disease with high prevalence among older people, occurs from molecular or nanometer level and extends gradually to higher degrees of the ultrastructure of cartilage, finally resulting in irreversible structural and functional damages. This report aims to use atomic force microscopy (AFM) to investigate the protective effects of resveratrol (RV), a drug with good anti-inflammatory properties, on cellular morphology, membrane architecture, cytoskeleton, cell surface adhesion and stiffness at nanometer level in sodium nitroprusside (SNP)-induced apoptotic chondrocytes, a typical cellular OA model. CCK-8 assay showed that 100 μM RV significantly prevented SNP-induced cytotoxicity. AFM imaging and quantitative analysis showed that SNP potently induced chondrocytes changes including shrunk, round, lamellipodia contraction and decrease in adherent junctions among cells, as well as the destruction of biomechanics: 90% decrease in elasticity and 30% decrease in adhesion. In addition, confocal imaging analysis showed that SNP induced aggregation of the cytoskeleton and decrease in the expression of cytoskeletal proteins. More importantly, these SNP-induced damages to chondrocytes could be potently prevented by RV pretreatment. Interestingly, the biomechanical changes occurred before morphological changes could be clearly observed during SNP-induced apoptosis, indicating that the biomechanics of cellular membrane may be a more robust indicator of cell function. Collectively, our data demonstrate that RV prevents SNP-induced apoptosis of chondrocytes by regulating actin organization, and that AFM-based technology can be developed into a powerful and sensitive method to study the interaction mechanisms between chondrocytes and drugs. PMID:24632762

  6. Effects of high hydrostatic pressure on Escherichia coli ultrastructure, membrane integrity and molecular composition as assessed by FTIR spectroscopy and microscopic imaging techniques.

    PubMed

    Prieto-Calvo, María; Prieto, Miguel; López, Mercedes; Alvarez-Ordóñez, Avelino

    2014-01-01

    High hydrostatic pressure (HHP) is a novel food processing technology that is considered as an attractive alternative to conventional heat treatments for the preservation of foods, due to its lethal effects on pathogenic and spoilage microorganisms, while causing minor effects on food quality and sensorial attributes. This study is aimed at investigating how HHP treatments at varying intensities in the range 50-900 MPa affect the viability, membrane integrity, ultrastructure and molecular composition of Escherichia coli. Results of membrane integrity tests (measurement of cellular leakage and monitoring of propidium iodide uptake through fluorescence microscopy) and ultrastructural observations by transmission electron microscopy demonstrated that HHP gave rise to cellular enlargement, membrane damage or detachment, DNA and protein denaturation and loss of intracellular contents. Fourier-transform infrared (FTIR) spectroscopy analyses evidenced minor changes in molecular composition in response to high pressures, which were mostly observed on the spectral region w4 (1200-900 cm-1), mainly informative of carbohydrates and polysaccharides of the cell wall. These findings suggest that exposure of E. coli cells to HHP causes alterations in their physical integrity while producing minor modifications in biochemical cellular composition. The current study increases the knowledge on the mechanisms of E. coli inactivation by HHP and provides valuable information for the design of more effective food preservation regimes based on the integration of mild HHP in combination with other food preservation strategies into a multi-target hurdle technology approach. PMID:25529018

  7. Histology and Ultrastructure of Transitional Changes in Skin Morphology in the Juvenile and Adult Four-Striped Mouse (Rhabdomys pumilio)

    PubMed Central

    Stewart, Eranée; Ajao, Moyosore Salihu

    2013-01-01

    The four-striped mouse has a grey to brown coloured coat with four characteristic dark stripes interspersed with three lighter stripes running along its back. The histological differences in the skin of the juvenile and adult mouse were investigated by Haematoxylin and Eosin and Masson Trichrome staining, while melanocytes in the skin were studied through melanin-specific Ferro-ferricyanide staining. The ultrastructure of the juvenile skin, hair follicles, and melanocytes was also explored. In both the juvenile and adult four-striped mouse, pigment-containing cells were observed in the dermis and were homogeneously dispersed throughout this layer. Apart from these cells, the histology of the skin of the adult four-striped mouse was similar to normal mammalian skin. In the juvenile four-striped mouse, abundant hair follicles of varying sizes were observed in the dermis and hypodermis, while hair follicles of similar size were only present in the dermis of adult four-striped mouse. Ultrastructural analysis of juvenile hair follicles revealed that the arrangement and differentiation of cellular layers were typical of a mammal. This study therefore provides unique transition pattern in the four-striped mouse skin morphology different from the textbook description of the normal mammalian skin. PMID:24288469

  8. High resolution imaging of the ultrastructure of living algal cells using soft x-ray contact microscopy

    SciTech Connect

    Ford, T.W.; Cotton, R.A.; Page, A.M.; Tomie, T.; Majima, T.; Stead, A.D.

    1995-12-31

    Soft x-ray contact microscopy provides the biologist with a technique for examining the ultrastructure of living cells at a much higher resolution than that possible by various forms of light microscopy. Readout of the developed photoresist using atomic force microscopy (AFM) produces a detailed map of the carbon densities generated in the resist following exposure of the specimen to water-window soft x-rays (2--4nm) produced by impact of a high energy laser onto a suitable target. The established high resolution imaging method of transmission electron microscopy (TEM) has inherent problems in the chemical pre-treatment required for producing the ultrathin sections necessary for this technique. Using the unicellular green alga Chlamydomonas the ultrastructural appearance of the cells following SXCM and TEM has been compared. While SXCM confirms the basic structural organization of the cell as seen by TEM (e.g., the organization of the thylakoid membranes within the chloroplast; flagellar insertion into the cytoplasm), there are important differences. These are in the appearance of the cell covering and the presence of carbon-dense spherical cellular inclusions.

  9. Survival and ultrastructural features of peach palm (Bactris gasipaes, Kunth) somatic embryos submitted to cryopreservation through vitrification.

    PubMed

    Heringer, Angelo Schuabb; Steinmacher, Douglas André; Schmidt, Éder Carlos; Bouzon, Zenilda Laurita; Guerra, Miguel Pedro

    2013-10-01

    Bactris gasipaes (Arecaceae), also known as peach palm, was domesticated by Amazonian Indians and is cultivated for its fruit and heart-of-palm, a vegetable grown in the tree's inner core. Currently, the conservation of this species relies on in situ conditions and field gene banks. Complementary conservation strategies, such as those based on in vitro techniques, are indicated in such cases. To establish an appropriate cryopreservation protocol, this study aimed to evaluate the ultrastructural features of B. gasipaes embryogenic cultures submitted to vitrification and subsequent cryogenic temperatures. Accordingly, somatic embryo clusters were submitted to Plant Vitrification Solution 3 (PVS3). In general, cells submitted to PVS3 had viable cell characteristics associated with apparently many mitochondria, prominent nucleus, and preserved cell walls. Cells not incubated in PVS3 did not survive after the cryogenic process in liquid nitrogen. The best incubation time for the vitrification technique was 240 min, resulting in a survival rate of 37 %. In these cases, several features were indicative of quite active cell metabolism, including intact nuclei and preserved cell walls, an apparently many of mitochondria and lipid bodies, and the presence of many starch granules and condensed chromatin. Moreover, ultrastructure analysis revealed that overall cellular structures had been preserved after cryogenic treatment, thus validating the use of vitrification in conjunction with cryopreservation of peach palm elite genotypes, as well as wild genotypes, which carry a rich pool of genes that must be conserved. PMID:23636432

  10. Pirin Inhibits Cellular Senescence in Melanocytic Cells

    PubMed Central

    Licciulli, Silvia; Luise, Chiara; Scafetta, Gaia; Capra, Maria; Giardina, Giuseppina; Nuciforo, Paolo; Bosari, Silvano; Viale, Giuseppe; Mazzarol, Giovanni; Tonelli, Chiara; Lanfrancone, Luisa; Alcalay, Myriam

    2011-01-01

    Cellular senescence has been widely recognized as a tumor suppressing mechanism that acts as a barrier to cancer development after oncogenic stimuli. A prominent in vivo model of the senescence barrier is represented by nevi, which are composed of melanocytes that, after an initial phase of proliferation induced by activated oncogenes (most commonly BRAF), are blocked in a state of cellular senescence. Transformation to melanoma occurs when genes involved in controlling senescence are mutated or silenced and cells reacquire the capacity to proliferate. Pirin (PIR) is a highly conserved nuclear protein that likely functions as a transcriptional regulator whose expression levels are altered in different types of tumors. We analyzed the expression pattern of PIR in adult human tissues and found that it is expressed in melanocytes and has a complex pattern of regulation in nevi and melanoma: it is rarely detected in mature nevi, but is expressed at high levels in a subset of melanomas. Loss of function and overexpression experiments in normal and transformed melanocytic cells revealed that PIR is involved in the negative control of cellular senescence and that its expression is necessary to overcome the senescence barrier. Our results suggest that PIR may have a relevant role in melanoma progression. PMID:21514450

  11. First ultrastructural observations on gastritis caused by Physaloptera clausa (Spirurida: Physalopteridae) in hedgehogs (Erinaceus europeaus).

    PubMed

    Gorgani-Firouzjaee, T; Farshid, A A; Naem, S

    2015-10-01

    Ultrastructural changes of gastritis due to infection with Physaloptera clausa in 12 fresh carcasses of euthanized European hedgehogs (Erinaceus europaeus) collected from different part of Urmia, Iran, in which they were highly populated with this animal, six females and six males were subjected to detail necropsy with special reference to the stomach. Macroscopic changes of stomach were recorded and some of the worms collected. Based on number of parasites present in the stomach, they were divided into light infection, mild infection, and severe infection. Parasites were collected, and worms identification of the species was confirmed on the basis of light microscope examination with reference to keys. Tissues fixed in 3% glutaraldehyde, post-fixed in 1% osmium tetroxide and processed and plastic embedded; ultrathin sections of 60-70 nm were cut and stained with uranyl acetate and lead citrate; electron microscopic observations showed that, in light infection some changes were observed in gastric cells such as dilatation and vesiculation of the endoplasmic reticulum, large numbers of lipid granules, mitochondrial swelling, nuclear chromatin margination, and some nucleus showed washed out appearance. Other cells showed some alterations in mitochondria, dilatation of smooth endoplasmic reticulum, loss of both free and bound ribosomes, vesiculation in cytoplasm, and increase Golgi apparatus and secretory vesicles. The inflammatory cells including lymphocytes, macrophages, mast cells, and predominantly eosinophils were identified. In moderate infection, the cellular pattern of gastric mucosa replaced with inflammatory cells. The marked increase of macrophages and other inflammatory cell was observed. A particular finding in our study was the presence of globule leukocyte in the moderate stage. Moreover, scant formation and distribution of collagen fibers as well as fibroblasts were also noted. In severe infection, the most obvious observation was marked distribution

  12. Pulmonary ultrastructure of the late aspects of human paraquat poisoning.

    PubMed Central

    Dearden, L. C.; Fairshter, R. D.; McRae, D. M.; Smith, W. R.; Glauser, F. L.; Wilson, A. F.

    1978-01-01

    The pulmonary ultrastructure of the late aspects of a case of human paraquat poisoning is investigated and compared with normal human pulmonary ultrastructure. Alveoli in the paraquat patient are numerically reduced in comparison to the control. They are filled with edematous proteinaceous plasma-like fluid containing erythrocytes, macrophages, leukocytes, fibroblast-like cells, platelets, and fibrin. These alveoli are lined by granular pneumocytes. Interstitial areas in the paraquat patient are greatly expanded and there are no alveolar septums. Interstitial areas contain proteinaceous plasma-like material, collagen, fibrin, platelets, mature fibroblasts, plasma cells, many leukocytes, numerous erythrocytes, and capillaries. Capillary permeability seems to be enhanced in the paraquat patient either by vesicles forming transendothelial channels or pores or by disruption of endothelial cells. Images Figure 1 Figure 2 Figures 3-7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:213978

  13. Ultrastructural insights into morphology and reproductive mode of Blastocystis hominis.

    PubMed

    Zhang, Xu; Zhang, Siwei; Qiao, Jiying; Wu, Xiaomin; Zhao, Liming; Liu, Yansheng; Fan, Xiaojun

    2012-03-01

    To understand well the morphology and reproductive mode of Blastocystis hominis, with the help of transmission electron microscopy and scanning electron microscopy the ultrastructural details of B. hominis from fresh diarrheal specimens and cultured strains were observed. In both fecal samples and culture conditions, there were vacuolar and granular forms. In diarrhea, it exists in multivacuolar, avacuolar, and amoeboid forms. In the in vitro culture, vacuolar form could transform to granular form. The most commonly noticed structure on the cell surface was surface coat with diversity in appearance (the funiform, lamellar, filiform, and floccose in different thickness) and distributions. Three modes of reproduction were confirmed, they were binary fission, plasmotomy, and budding. Under the impact of host's response, the ultrastructures of surface coat, nucleus, and mitochondrion-like organelle sometimes changed. PMID:21845408

  14. Bacillus atrophaeus Outer Spore Coat Assembly and Ultrastructure

    SciTech Connect

    Plomp, M; Leighton, T J; Wheeler, K E; Pitesky, M E; Malkin, A J

    2005-11-21

    Our previous atomic force microscopy (AFM) studies successfully visualized native Bacillus atrophaeus spore coat ultrastructure and surface morphology. We have shown that the outer spore coat surface is formed by a crystalline array of {approx}11 nm thick rodlets, having a periodicity of {approx}8 nm. We present here further AFM ultrastructural investigations of air-dried and fully hydrated spore surface architecture. In the rodlet layer, planar and point defects, as well as domain boundaries, similar to those described for inorganic and macromolecular crystals, were identified. For several Bacillus species, rodlet structure assembly and architectural variation appear to be a consequence of species-specific nucleation and crystallization mechanisms that regulate the formation of the outer spore coat. We propose a unifying mechanism for nucleation and self-assembly of this crystalline layer on the outer spore coat surface.

  15. Ultrastructural observation of electron irradiation damage of lamellar bone.

    PubMed

    Hong, S I; Hong, S K; Wallace, J M; Kohn, D H

    2009-04-01

    The ultrastructure of murine femoral lamellar bone and the effect of electron irradiation (200 kV) on collagen and mineral features were investigated using in situ high resolution transmission electron microscopy (HRTEM). Bands of collagen fibrils were mostly aligned parallel to the long axis of the bones, with some bands of fibrils inclined in longitudinal sections. The similarity of the ultrastructure between the longitudinal and transverse sections supports the rotated plywood structure of the lamellar bone. The collagen fibrils appeared damaged and the mineral crystals were coarsened after electron irradiation. Continuous diffraction rings became spotty and the contrast between rings and the background became sharper, further suggesting coarsening of apatite crystals and increased crystallinity after irradiation. No new phases were observed after irradiation. Both the damage to collagen and coarsening of apatite crystals can deteriorate the strength and integrity of bone, and may provide insight into fracture in patients who have undergone radiation therapy. PMID:19034616

  16. Ultrastructural injury to human spermatozoa after freezing and thawing.

    PubMed

    Woolley, D M; Richardson, D W

    1978-07-01

    The ultrastructure of human spermatozoa at various stages of the freezing and thawing process was studied. In addition to conventional fixations, a freeze-substitution method was used to examine spermatozoa before they were thawed. Dilution in a glycerol-egg yolk-citrate medium caused slight swelling of the acrosome. During slow freezing, when large ice crystals grow in the diluent, the sperm plasmalemma became tighter, the mitochondria had more angular profiles and there was a reduction in electron density of the acrosomal contents. After thawing, the apical segment of the acrosome usually became swollen and the mitochondria appeared rounded. We deduce that these ultrastructural changes occur either during or after the thawing procedure. PMID:567693

  17. Cellular senescence: when bad things happen to good cells.

    PubMed

    Campisi, Judith; d'Adda di Fagagna, Fabrizio

    2007-09-01

    Cells continually experience stress and damage from exogenous and endogenous sources, and their responses range from complete recovery to cell death. Proliferating cells can initiate an additional response by adopting a state of permanent cell-cycle arrest that is termed cellular senescence. Understanding the causes and consequences of cellular senescence has provided novel insights into how cells react to stress, especially genotoxic stress, and how this cellular response can affect complex organismal processes such as the development of cancer and ageing. PMID:17667954

  18. Immunological and ultrastructural studies in acute biphenotypic leukaemia.

    PubMed Central

    Shetty, V; Chitale, A; Matutes, E; Buccheri, V; Morilla, R; Catovsky, D

    1993-01-01

    AIMS--To compare the sensitivity of the ultrastructural method to detect myeloperoxidase (MPO) with light microscopy and immunocytochemistry using an anti-MPO antibody; to examine the expression of lymphoid antigens in relation to MPO activity in blast cells from cases of biphenotypic leukaemia. METHODS--Blast cells from 14 cases of biphenotypic acute leukaemia were analysed. Immunological markers were performed by single or double immunofluorescence staining on a flow cytometer. The presence of MPO was determined by light microscopy, electron microscopy on fixed and unfixed cells, and by immunoalkaline phosphatase with an anti-MPO antibody. The immunogold method was applied at the ultrastructural level to assess the expression of lymphoid and myeloid antigens at the same time as the MPO activity. RESULTS--Six of the 14 cases were initially classified as acute lymphoblastic leukaemia (ALL) and eight as acute myeloid leukaemia (AML). MPO activity was shown at the ultrastructural level in 4-99% blasts from all cases. Six of the 14 were MPO negative by light microscopy and three of these were negative with the antibody anti-MPO. Coexpression of lymphoid antigens (CD19, CD10, or CD2) and MPO was shown by the immunogold method in four out of 11 cases; in seven cases the blasts coexpressed myeloid antigens (CD13, CD33) and MPO. CONCLUSIONS--Electron microscopy is more sensitive for showing MPO than light microscopy and immunocytochemistry; the immunogold method combined with MPO used at the ultrastructural level can help to define the cell lineage involved in biphenotypic leukaemia by highlighting the myeloid component defined by MPO. Images PMID:8227405

  19. Ultrastructural alterations in skeletal muscle fibers of rats after exercise

    NASA Technical Reports Server (NTRS)

    Akuzawa, M.; Hataya, M.

    1982-01-01

    Ultrastructural alterations in skeletal muscle fibers were electron microscopically studied in rats forced to run on the treadmill until all-out. When they were mild and limited to relatively small areas, the reconstruction of filaments ensued within 10 days without infiltration of cells. When they were severe and extensive, phagocytes infiltrated in the lesions and removed degenerative sacroplasmic debris from muscle fibers. A little later, myoblasts appeared and regeneration was accomplished in 30 days in much the same manner as in myogenesis.

  20. Ultrastructure of organic cell walls in Proterozoic microalgae

    NASA Astrophysics Data System (ADS)

    Moczydlowska-Vidal, M.

    2009-04-01

    The antiquity of life has been well appreciated since the discoveries of microfossils and confirmation of their authenticity, as well as the recognition of geochemical signs of biogenicity in the Archean successions. Resolving the biological affinities of early biota is essential for the unravelling the changes that led to modern biodiversity, but also for the detection of possible biogenic records outside of the terrestrial biosphere. Advanced techniques in microscopy, tomography and spectroscopy applied to examine individual microfossils at the highest attainable spatial resolution have provided unprecedented insights into micro- and nano-scale structure and composition of organic matter. Transmission and scanning electron microscopy studies of the wall ultrastructure of sphaeromorphic and ornamented acritarchs have revealed complex, single to multilayered walls, having a unique texture in sub-layers and an occasionally preserved trilaminar sheath structure (TLS) of the cell wall. A variety of optical characteristics, the electron density and texture of fabrics of discrete layers, and the properties of biopolymers may indicate the polyphyletic affiliations of such microfossils and/or the preservation of various stages (vegetative, resting) in their life cycle. I evaluate the morphological features of organic-walled unicellular microfossils in conjunction with their cell wall ultrastructure to infer their life cycle and to recognize various developmental stages represented among microfossils attributed to a single form-taxon. Several cases of fine wall ultrastructure in microfossils have been documented and have had a conclusive influence on understanding their affinities. Some Proterozoic and Cambrian leiosphaerids are of algal affinities. Certain specimens represent chlorophyceaens, having the multilayered composite wall with TLS structure known from vegetative and resting cells in modern genera of the Chlorococcales and Volvocales. The wall ultrastructure of

  1. Cystosarcoma phylloides. A steroid receptor and ultrastructure analysis.

    PubMed

    Kesterson, G H; Georgiade, N; Seigler, H F; Barton, T K; McCarty, K S; McCarty, K S

    1979-11-01

    Six cases of cystosarcoma phylloides were evaluated by ultrastructure and steroid receptor analysis. Electron microscopy of the lesions supported previous reports of a heterogeneous tumor consisting of pleomorphic mesenchyme and normal or proliferative epithelium. In each case estrogen and progesterone receptor analysis indicated the presence of a nonsaturable estrogen and progesterone 4S binding protein rather than a specific steroid receptor as suggested by previous studies. PMID:228617

  2. Composition and Ultrastructure of Streptomyces venezuelae

    PubMed Central

    Bradley, S. G.; Ritzi, Donna

    1968-01-01

    Streptomyces venezuelae is a filamentous bacterium with branching vegetative hyphae embedded in the substrate and aerial hyphae bearing spores. The exterior of the spore is inlaid with myriads of tiny rods which can be removed with xylene. The spore wall is approximately 30 nanometers thick. Occasionally, it can be seen that the plasma membrane and the membranous bodies within a spore are connected. The spore's germ plasm is not separated from the cytoplasm by a nuclear envelope. The cell walls of the vegetative hyphae, which are about 15 nanometers thick, are structurally and chemically similar to those of gram-positive bacteria. The numerous internal membranous bodies, some of which arise from the plasma membrane of the vegetative hypha, may be vesicular, whirled, or convoluted. Membranous bodies are usually prominent at the hyphal apices and are associated with septum formation. The germ plasm is an elongate, contorted, centrally placed area of lower electron density than the hyphal cytoplasm. The spores differ from the vegetative hyphae, not only in fine structure, but also in the arginine and leucine contents of their total cellular proteins. Images PMID:5669907

  3. Rac1 drives intestinal stem cell proliferation and regeneration

    PubMed Central

    Myant, Kevin B; Scopelliti, Alessandro; Haque, Sara; Vidal, Marcos; Sansom, Owen J; Cordero, Julia B

    2013-01-01

    Adult stem cells are responsible for maintaining the balance between cell proliferation and differentiation within self-renewing tissues. The molecular and cellular mechanisms mediating such balance are poorly understood. The production of reactive oxygen species (ROS) has emerged as an important mediator of stem cell homeostasis in various systems. Our recent work demonstrates that Rac1-dependent ROS production mediates intestinal stem cell (ISC) proliferation in mouse models of colorectal cancer (CRC). Here, we use the adult Drosophila midgut and the mouse small intestine to directly address the role of Rac1 in ISC proliferation and tissue regeneration in response to damage. Our results demonstrate that Rac1 is necessary and sufficient to drive ISC proliferation and regeneration in an ROS-dependent manner. Our data point to an evolutionarily conserved role of Rac1 in intestinal homeostasis and highlight the value of combining work in the mammalian and Drosophila intestine as paradigms to study stem cell biology. PMID:23974108

  4. Ultrastructural characterization of the pronephric glomerulus development in zebrafish.

    PubMed

    Zhu, Xiaodong; Chen, Zhaohong; Zeng, Caihong; Wang, Ling; Xu, Feng; Hou, Qing; Liu, Zhihong

    2016-08-01

    The zebrafish pronephros is a valuable model for studying kidney development and diseases. Ultrastructural studies have revealed that zebrafish and mammals share similarities in nephron structures such as podocytes, slit diaphragms, glomerular basement membrane, and endothelium. However, the basic ultrastructural features of the pronephric glomerulus during glomerulogenesis have not been characterized. To understand these features, it is instructive to consider the developmental process of the pronephros glomerulus. Here, we describe the ultrastructural features of pronephric glomerulus in detail from 24 h hours post-fertilization (hpf) to 144 hpf, the period during which the pronephric glomerulus develops from initiation to its mature morphology. The pronephric glomerulus underwent progressive morphogenesis from 24 to 72 hpf, and presumptive glomerular cells were observed ventral to the aorta region at 24 hpf. The nascent glomerular basement membrane and initial lumen were formed at 36 hpf. A lumen was clearly visible in the region of the pronephros at 48 hpf. At 60 hpf, the pronephric glomerulus contained more patches of capillaries. After these transformations, the complex capillary vessel networks had formed inside the glomerulus, which was surrounded by podocyte bodies with elaborate foot processes as well as well-formed glomerular basement membrane by 72 hpf. The number of renal glomerular cells rapidly increased, and the glomerulus presented its delicate structural features by 96 hpf. Morphogenesis was completed at 120 hpf with the final formation of the pronephric glomerulus. J. Morphol. 277:1104-1112, 2016. © 2016 Wiley Periodicals, Inc. PMID:27185367

  5. Seeding Specificity and Ultrastructural Characteristics of Infectious Recombinant Prions

    PubMed Central

    Piro, Justin R.; Wang, Fei; Walsh, Daniel J.; Rees, Judy R.; Ma, Jiyan; Supattapone, Surachai

    2012-01-01

    Infectious mouse prions can be produced from a mixture of bacterially expressed recombinant prion protein (recPrP), palmitoyloleoylphosphatidylglycerol (POPG), and RNA [Wang, F.; et al. (2010) Science 327, 1132 ]. In contrast, amyloid fibers produced from pure recPrP without POPG or RNA (recPrP fibers) fail to infect wild type mice [Colby, D. W.; et al. (2010) PLoS Pathog. 387, e1000736 ]. We compared the seeding specificity and ultrastructural features of infectious recombinant prions (recPrPSc) with those of recPrP fibers. Our results indicate that PrP fibers are not able to induce the formation of PrPSc molecules from wild type mouse brain homogenate substrate in serial protein misfolding cyclic amplification (sPMCA) reactions. Conversely, recPrPSc molecules did not accelerate the formation of amyloid in vitro, under conditions that produce recPrP fibers spontaneously. Ultrastructurally, recombinant prions appear to be small spherical aggregates rather than elongated fibers, as determined by atomic force and electron microscopy. Taken together, our results show that recPrPSc molecules and PrP fibers have different ultrastructural features and seeding specificities, suggesting that prion infectivity may be propagated by a specific and unique assembly pathway facilitated by cofactors. PMID:21776987

  6. Cardiomyocyte ultrastructural damage in β-thalassaemic mice

    PubMed Central

    Sanyear, Chanita; Butthep, Punnee; Nithipongvanich, Ramaneeya; Sirankapracha, Pornpan; Winichagoon, Pranee; Fucharoen, Suthat; Svasti, Saovaros

    2013-01-01

    β-thalassaemia is a hereditary anaemia resulting from the absence or reduction in β-globin chain production. Heart complications related to iron overload are the most serious cause of death in these patients. In this report cardiac pathology of β-thalassaemic mice was evaluated by light and electron microscopy. The study was carried out in thalassaemic mice carrying human β-thalassaemia mutation, IVSII-654 (654), transgenic mice carrying human βE-globin transgene insertion (E4), thalassaemic mice with human βE-globin transgene insertion (654/E4) and homozygous thalassaemic mice rescued by the human βE-globin transgene (R), which is generated by cross-breeding between the 654 and E4 mice. Histology showed iron deposition in cardiac myocytes of 654 and R mice, but the ultrastructural damage was observed only in the R mice when compared with the wild type, 654, E4 and 654/E4 mice. Histopathological changes in the cardiomyocytes of the R mice included mitochondrial swelling, loss of myofilaments and the presence of lipofuscin, related to the increased level of tissue iron content. The progressive ultrastructural pathology in R mice cardiomyocytes is consistent with the ultrastructural pathology previously studied in patients with thalassaemia. Thus, this R thalassaemic mouse model is suitable for in vivo pathophysiological study of thalassaemic heart. PMID:24020406

  7. Innervation of amphibian reproductive system. Histological and ultrastructural studies.

    PubMed

    Cisint, Susana; Crespo, Claudia A; Medina, Marcela F; Iruzubieta Villagra, Lucrecia; Fernández, Silvia N; Ramos, Inés

    2014-10-01

    In the present study we describe for the first time in anuran amphibians the histological and ultrastructural characteristics of innervation in the female reproductive organs. The observations in Rhinella arenarum revealed the presence of nerve fibers located predominantly in the ovarian hilium and in the oviduct wall. In both organs the nerves fibers are placed near blood vessels and smooth muscles fibers. In the present study the histological observations were confirmed using antibodies against peripherin and neurofilament 200 proteins. Ultrastructural analyses demonstrated that the innervation of the reproductive organs is constituted by unmyelinated nerve fibers surrounded by Schwann cells. Axon terminals contain a population of small, clear, translucent vesicles that coexist with a few dense cored vesicles. The ultrastructural characteristics together with the immunopositive reaction to tyrosine hydroxylase of the nerve fibers and the type of synaptic vesicles present in the axon terminal would indicate that the reproductive organs of R. arenarum females are innervated by the sympathetic division of the autonomic nervous system. PMID:24882461

  8. Effects of hypoxic preconditioning on synaptic ultrastructure in mice.

    PubMed

    Liu, Yi; Sun, Zhishan; Sun, Shufeng; Duan, Yunxia; Shi, Jingfei; Qi, Zhifeng; Meng, Ran; Sun, Yongxin; Zeng, Xianwei; Chui, Dehua; Ji, Xunming

    2015-01-01

    Hypoxic preconditioning (HPC) elicits resistance to more drastic subsequent insults, which potentially provide neuroprotective therapeutic strategy, but the underlying mechanisms remain to be fully elucidated. Here, we examined the effects of HPC on synaptic ultrastructure in olfactory bulb of mice. Mice underwent up to five cycles of repeated HPC treatments, and hypoxic tolerance was assessed with a standard gasp reflex assay. As expected, HPC induced an increase in tolerance time. To assess synaptic responses, Western blots were used to quantify protein levels of representative markers for glia, neuron, and synapse, and transmission electron microscopy was used to examine synaptic ultrastructure and mitochondrial density. HPC did not significantly alter the protein levels of astroglial marker (GFAP), neuron-specific markers (GAP43, Tuj-1, and OMP), synaptic number markers (synaptophysin and SNAP25) or the percentage of excitatory synapses versus inhibitory synapses. However, HPC significantly affected synaptic curvature and the percentage of synapses with presynaptic mitochondria, which showed concomitant change pattern. These findings demonstrate that HPC is associated with changes in synaptic ultrastructure. PMID:25155519

  9. Ultrastructure and mitochondrial numbers in pre- and postpubertal pig oocytes.

    PubMed

    Pedersen, Hanne Skovsgaard; Callesen, Henrik; Løvendahl, Peter; Chen, Fenghua; Nyengaard, Jens Randel; Nikolaisen, Nanett Kvist; Holm, Peter; Hyttel, Poul

    2016-04-01

    Prepubertal pig oocytes are associated with lower developmental competence. The aim of this experiment was to conduct an exhaustive survey of oocyte ultrastructure and to use a design-unbiased stereological approach to quantify the numerical density and total number of mitochondria in oocytes with different diameters from pre- and postpubertal pigs. The ultrastructure of smaller prepubertal immature oocytes indicated active cells in close contact with cumulus cells. The postpubertal oocytes were more quiescent cell types. The small prepubertal oocytes had a lower total mitochondrial number, but no differences were observed in mitochondrial densities between groups. Mature postpubertal oocytes adhered to the following characteristics: presence of metaphase II, lack of contact between cumulus cells and oocyte, absence of rough endoplasmic reticulum and Golgi complexes, peripheral location of cortical granules and central localisation of mitochondria, vesicles and lipid droplets. Prepubertal oocytes displayed more variation. The ultrastructure of large pre- and postpubertal oocytes was compatible with higher developmental competence, whereas that of smaller prepubertal oocytes could explain their reduced capacity. The higher number of mitochondria in large pre- and postpubertal oocytes could have an influence on oocyte competence, by increasing the pool of mitochondria available for early embryonic development. PMID:25482576

  10. Roles of cell volume in molecular and cellular biology.

    PubMed

    Dubois, Jean-Marc; Rouzaire-Dubois, Béatrice

    2012-04-01

    Extracellular tonicity and volume regulation control a great number of molecular and cellular functions including: cell proliferation, apoptosis, migration, hormone and neuromediator release, gene expression, ion channel and transporter activity and metabolism. The aim of this review is to describe these effects and to determine if they are direct or are secondarily the result of the activity of second messengers. PMID:22192789

  11. Cellular Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  12. JPRS report proliferation issues

    SciTech Connect

    1991-12-13

    This report contains foreign media information on issues related to worldwide proliferation and transfer activities in nuclear, chemical, and biological weapons, including delivery systems and the transfer of weapons relevant technologies. The following locations are included: (1) South Africa; (2) China; (3) North and South Korea, Taiwan; (4) Hungary; (5) Brazil; (6) India, Iran, Israel, Pakistan; (7) Soviet Union; and (8) Austria, Germany, United Kingdom.

  13. JPRS report proliferation issues

    SciTech Connect

    1991-11-07

    This report contains foreign media information on issues related to worldwide proliferation and transfer activities in nuclear, chemical, and biological weapons, including delivery systems and the transfer of weapons relevant technologies. The following locations are included: (1) South Africa; (2) China; (3) North and South Korea, Japan; (4) Bulgaria, Czechoslovakia; (5) Argentina, Brazil; (6) India, Iran, Israel, Pakistan, Libya, Iraq, Egypt; (7) Soviet Union; and (8) Belgium, Germany, United Kingdom, Netherlands, France.

  14. JPRS report proliferation issues

    SciTech Connect

    1991-12-02

    This report contains foreign media information on issues related to worldwide proliferation and transfer activities in nuclear, chemical, and biological weapons, including delivery systems and the transfer of weapons relevant technologies. The following locations are included: (1) South Africa; (2) China; (3) North and South Korea, Taiwan; (4) Hungary, Yugoslavia; (5) Brazil, Argentina; (6) Afghanistan, India, Iran, Iraq, Israel, Pakistan; (7) Soviet Union; and (8) France, Germany, Italy, Switzerland.

  15. JPRS report proliferation issues

    SciTech Connect

    1991-09-27

    This report contains foreign media information on issues related to worldwide proliferation and transfer activities in nuclear, chemical, and biological weapons, including delivery systems and the transfer of weapons relevant technologies. The following locations are included: (1) South Africa, Namibia; (2) China; (3) South Korea, Australia, Indonesia, Japan, Philippines; (4) Yugoslavia; (5) Brazil, Argentina, Cuba; (6) India, Libya, Pakistan; (7) Soviet Union; and (8) France, Germany, Netherlands.

  16. Pathologic and ultrastructural changes of acute and chronic delta hepatitis in an experimentally infected chimpanzee.

    PubMed Central

    Govindarajan, S.; Fields, H. A.; Humphrey, C. D.; Margolis, H. S.

    1986-01-01

    A hepatitis B surface antigen (HBsAg) chronic carrier chimpanzee experimentally superinfected with delta virus (DV) developed chronic DV infection. Over a period of 12 months, serologic and biochemical changes were correlated with morphologic abnormalities of the liver. Severe hepatic necrosis and inflammation accompanied the initial acute episode of hepatitis on Day 35 after inoculation, followed by complete resolution of these lesions over the next 3 months. A second episode of hepatitis occurred on Day 145, and severe necrosis and inflammation recurred along with the reappearance of delta antigen in the hepatocytes. Delta antigen persisted in the liver following the second episode of hepatitis and has remained positive throughout the observation period of 1 year. During the initial acute episode, the hepatocytes exhibited foamy cytoplasmic changes resembling microvesicular fat. However, ultrastructural studies of the same cells revealed only vacuolization of the cytoplasm without evidence of fat droplets. The inflammatory infiltrate during both episodes of hepatitis demonstrated a striking predominance of macrophages over lymphocytes. Hepatocyte abnormalities observed by electron microscopy included vacuoles, proliferated endoplasmic reticulum, and tubules similar to those seen in posttransfusion non-A, non-B hepatitis. However, the tubular and reticular abnormalities coincided with delta antigen expression in liver biopsies detected by direct immunoperoxidase staining and abnormal alanine aminotransferase levels in the serum, which suggests a possible causal relationship. Nuclear abnormalities were not seen. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:3511726

  17. Ultrastructural characteristics of carcinogen-induced nondysplastic changes in tracheal epithelium

    SciTech Connect

    Klein-Szanto, A.J.P.; Topping, D.C.; Heckman, C.A.; Nettesheim, P.

    1980-01-01

    Nondysplastic hypotrophic and metaplastic epithelial alterations induced by dimethylbenz(a)anthracene in isogenic tracheal transplants were studied by light and electron microscopy 3 to 24 months after cessation of a 4-week carcinogen exposure. Hypotrophic epithelium observed at all time points was characterized by the presence of nonciliated cells that adopted either cuboidal or squamous shapes, forming simple or bistratified epithelia. Most of these cells, as well as some metaplastic cells, exhibited features of mucin-secreting cells. The metaplastic epithelia showed nonkeratinizing squamous metaplasia, closely related to transitional metaplasia, and keratinizing squamous metaplasia, which presented either an atrophic or an acanthotic epithelium. Although many of these epithelia showed morphologic features of normal stratified epithelia, several nonkeratinizing squamous metaplasias and acanthotic keratinizing squamous metaplasias exhibited some irregularities, probably representing very early atypical ultrastructural features (i.e., perinuclear concentration of tonofilament bundles, the presence of dark and clear basal epithelial cells, interruptions and alterations of the basal lamina). These features were not observed in a group of early squamous metaplasias studied for comparative purposes 2 weeks after cessation of dimethylbenz(a)anthracene exposure, which were characterized by a combination of degenerative phenomena and increased cell proliferation.

  18. Proliferation and fission of peroxisomes - An update.

    PubMed

    Schrader, Michael; Costello, Joseph L; Godinho, Luis F; Azadi, Afsoon S; Islinger, Markus

    2016-05-01

    In mammals, peroxisomes perform crucial functions in cellular metabolism, signalling and viral defense which are essential to the health and viability of the organism. In order to achieve this functional versatility peroxisomes dynamically respond to molecular cues triggered by changes in the cellular environment. Such changes elicit a corresponding response in peroxisomes, which manifests itself as a change in peroxisome number, altered enzyme levels and adaptations to the peroxisomal structure. In mammals the generation of new peroxisomes is a complex process which has clear analogies to mitochondria, with both sharing the same division machinery and undergoing a similar division process. How the regulation of this division process is integrated into the cell's response to different stimuli, the signalling pathways and factors involved, remains somewhat unclear. Here, we discuss the mechanism of peroxisomal fission, the contributions of the various division factors and examine the potential impact of post-translational modifications, such as phosphorylation, on the proliferation process. We also summarize the signalling process and highlight the most recent data linking signalling pathways with peroxisome proliferation. PMID:26409486

  19. beta. -Adrenergic stimulation of brown adipocyte proliferation

    SciTech Connect

    Geloeen, A.; Collet, A.J.; Guay, G.; Bukowiecki, L.J. Laboratoire de Thermoregulation et Metabolisme Energetique, Lyon )

    1988-01-01

    The mechanisms of brown adipose tissue (BAT) growth were studied by quantitative photonic radioautography using tritiated thymidine to follow mitotic activity. To identify the nature of the adrenergic pathways mediating brown adipocyte proliferation and differentiation, the effects of cold exposure (4 days at 4{degree}C) on BAT growth were compared with those induced by treating rats at 25{degree}C with norepinephrine (a mixed agonist), isoproterenol (a {beta}-agonist), and phenylephrine (an {alpha}-agonist). Norepinephrine mimicked the effects of cold exposure, not only on the mitotic activity, but also on the distribution of the labeling among the various cellular types. Isoproterenol entirely reproduced the effects of norepinephrine both on the labeling index and on the cellular type labeling frequency. These results demonstrate that norepinephrine triggers a coordinated proliferation of brown adipocytes and endothelial cells in warm-exposed rats that is similar to that observed after cold exposure. They also suggest that cold exposure stimulates BAT growth by increasing the release of norepinephrine from sympathetic nerves and that the neurohormone activates mitoses in BAT precursor cells via {beta}-adrenergic pathways.

  20. CELLULAR MAGNESIUM HOMEOSTASIS

    PubMed Central

    Romani, Andrea M.P.

    2011-01-01

    Magnesium, the second most abundant cellular cation after potassium, is essential to regulate numerous cellular functions and enzymes, including ion channels, metabolic cycles, and signaling pathways, as attested by more than 1000 entries in the literature. Despite significant recent progress, however, our understanding of how cells regulate Mg2+ homeostasis and transport still remains incomplete. For example, the occurrence of major fluxes of Mg2+ in either direction across the plasma membrane of mammalian cells following metabolic or hormonal stimuli has been extensively documented. Yet, the mechanisms ultimately responsible for magnesium extrusion across the cell membrane have not been cloned. Even less is known about the regulation in cellular organelles. The present review is aimed at providing the reader with a comprehensive and up-to-date understanding of the mechanisms enacted by eukaryotic cells to regulate cellular Mg2+ homeostasis and how these mechanisms are altered under specific pathological conditions. PMID:21640700

  1. Histological characteristics and ultrastructure of polyethylene terephthalate LARS ligament after the reconstruction of anterior cruciate ligament in rabbits

    PubMed Central

    Yu, Shao-Bin; Yang, Rong-Hua; Zuo, Zhong-Nan; Dong, Qi-Rong

    2014-01-01

    Polyethylene terephthalate LARS ligament were the remnant of LARS ligament used for repairing posterior cruciate ligament obtained from operation. We want to study histological characteristics and ultrastructure of polyethylene terephthalate LARS ligament after the reconstruction of anterior cruciate ligament in rabbits. Therefore, we replaced the original ACL with polyethylene terephthalate LARS ligament which was covering with the remnant of ACL in 9 rabbits (L-LARS group), while just only polyethylene terephthalate LARS ligament were transplanted in 3 rabbits (LARS group) with the remnant of ACL. Compared with group LARS, inflammatory cell reaction and foreign body reaction were more significant in group L-LARS. Moreover, electron microscopy investigation showed the tissue near LARS fibers was highly cellular with a matrix of thin collagen fibrils (50-100 nm) in group L-LARS. These above findings suggest the polyethylene terephthalate LARS ligament possess the high biocompatibility, which contributes to the polyethylene terephthalate LARS covered with recipient connective tissues. PMID:25356104

  2. Ultrastructure of single cells, callus-like and monospore-like cells in Porphyra yezoensis ueda on semisolid culture medium

    NASA Astrophysics Data System (ADS)

    Mei, Junxue; Shen, Songdong; Jiang, Ming; Fei, Xiugeng

    2003-06-01

    It had been demonstrated that individual cells or protoplasts isolated from Porphyra thallus by enzyme could develop into normal leafy thalli in the same way as monospores, and that isolated cells develop in different way in liquid and on semi-solid media. The authors observed the ultrastructure of isolated vegetative cells cultured on semi-solid media and compared them with those of monospores and isolated cells cultured in liquid media. The results showed that subcellular structures were quite different among cells in different conditions. In their development, isolated cells on semi-solid media did not show the characteristic subcellular feature of monospore formation, such as production of fibrous vesicles. Callus-like cells formed on semi-solid media underwent a distinctive modification in cellular organization. They developed characteristic cell inclusions and a special 2-layer cell covering. Golgi bodies, ER, starch grains, mitochondria. Vacuoles were not commonly found in them.

  3. Modeling boundary conditions for balanced proliferation in metastatic latency

    PubMed Central

    Taylor, Donald P; Wells, Jakob Z; Savol, Andrej; Chennubhotla, Chakra; Wells, Alan

    2013-01-01

    Purpose Nearly half of cancer metastases become clinically evident five or more years after primary tumor treatment; thus metastatic cells survived without emerging for extended periods. This dormancy has been explained by at least two countervailing scenarios: cellular quiescence and balanced proliferation; these entail dichotomous mechanistic etiologies. To examine the boundary parameters for balanced proliferation, we performed in silico modeling. Experimental Design To illuminate the balanced proliferation hypothesis, we explored the specific boundary probabilities under which proliferating micrometastases would remain dormant. A two-state Markov chain Monte Carlo model simulated micrometastatic proliferation and death according to stochastic survival probabilities. We varied these probabilities across 100 simulated patients each with 1,000 metastatic deposits and documented whether the micrometastases exceeded one million cells, died out, or remained dormant (survived 1,218 generations). Results The simulations revealed a narrow survival probability window (49.7 – 50.8 percent) that allowed for dormancy across a range of starting cell numbers, and even then for only a small fraction of micrometastases. The majority of micrometastases died out quickly even at survival probabilities that led to rapid emergence of a subset of micrometastases. Within dormant metastases, cell populations depended sensitively on small survival probability increments. Conclusions Metastatic dormancy as explained solely by balanced proliferation is bounded by very tight survival probabilities. Considering the far larger survival variability thought to attend fluxing microenvironments, it is more probable that these micrometastatic nodules undergo at least periods of quiescence rather than exclusively being controlled by balanced proliferation. PMID:23329811

  4. Immunometabolism: Cellular Metabolism Turns Immune Regulator.

    PubMed

    Loftus, Róisín M; Finlay, David K

    2016-01-01

    Immune cells are highly dynamic in terms of their growth, proliferation, and effector functions as they respond to immunological challenges. Different immune cells can adopt distinct metabolic configurations that allow the cell to balance its requirements for energy, molecular biosynthesis, and longevity. However, in addition to facilitating immune cell responses, it is now becoming clear that cellular metabolism has direct roles in regulating immune cell function. This review article describes the distinct metabolic signatures of key immune cells, explains how these metabolic setups facilitate immune function, and discusses the emerging evidence that intracellular metabolism has an integral role in controlling immune responses. PMID:26534957

  5. Cellular microRNAs and Picornaviral Infections

    PubMed Central

    Wang, Miao; Gao, Zeqian; Pan, Li; Zhang, Yongguang

    2014-01-01

    microRNAs (miRNAs) are a subtype of short, endogenous, and non-coding RNAs, which post-transcriptionally regulate gene expression. The miRNA-mediated gene silencing mechanism is involved in a wide spectrum of biological processes, such as cellular proliferation, differentiation, and immune responses. Picornaviridae is a large family of RNA viruses, which includes a number of causative agents of many human and animal diseases viz., poliovirus, foot-and-mouth disease virus (FMDV), and coxsackievirus B3 (CVB3). Accumulated evidences have demonstrated that replication of picornaviruses can be regulated by miRNAs and picornaviral infections can alter the expression of cellular miRNAs. Herein, we outline the intricate interactions between miRNAs and picornaviral infections. PMID:24921242

  6. Cellular and molecular introduction to brain development.

    PubMed

    Jiang, Xiangning; Nardelli, Jeannette

    2016-08-01

    Advances in the study of brain development over the last decades, especially recent findings regarding the evolutionary expansion of the human neocortex, and large-scale analyses of the proteome/transcriptome in the human brain, have offered novel insights into the molecular mechanisms guiding neural maturation, and the pathophysiology of multiple forms of neurological disorders. As a preamble to reviews of this issue, we provide an overview of the cellular, molecular and genetic bases of brain development with an emphasis on the major mechanisms associated with landmarks of normal neural development in the embryonic stage and early postnatal life, including neural stem/progenitor cell proliferation, cortical neuronal migration, evolution and folding of the cerebral cortex, synaptogenesis and neural circuit development, gliogenesis and myelination. We will only briefly depict developmental disorders that result from perturbations of these cellular or molecular mechanisms, and the most common perinatal brain injuries that could disturb normal brain development. PMID:26184894

  7. Evaluating acellular versus cellular perfusate composition during prolonged ex vivo lung perfusion after initial cold ischaemia for 24 hours.

    PubMed

    Becker, Simon; Steinmeyer, Jasmin; Avsar, Murat; Höffler, Klaus; Salman, Jawad; Haverich, Axel; Warnecke, Gregor; Ochs, Matthias; Schnapper, Anke

    2016-01-01

    Normothermic ex vivo lung perfusion (EVLP) has developed as a powerful technique to evaluate particularly marginal donor lungs prior to transplantation. In this study, acellular and cellular perfusate compositions were compared in an identical experimental setting as no consensus has been reached on a preferred technique yet. Porcine lungs underwent EVLP for 12 h on the basis of an acellular or a cellular perfusate composition after 24 h of cold ischaemia as defined organ stress. During perfusion, haemodynamic and respiratory parameters were monitored. After EVLP, the lung condition was assessed by light and transmission electron microscopy. Aerodynamic parameters did not show significant differences between groups and remained within the in vivo range during EVLP. Mean oxygenation indices were 491 ± 39 in the acellular group and 513 ± 53 in the cellular group. Groups only differed significantly in terms of higher pulmonary artery pressure and vascular resistance in the cellular group. Lung histology and ultrastructure were largely well preserved after prolonged EVLP and showed only minor structural alterations which were similarly present in both groups. Prolonged acellular and cellular EVLP for 12 h are both feasible with lungs prechallenged by ischaemic organ stress. Physiological and ultrastructural analysis showed no superiority of either acellular or cellular perfusate composition. PMID:26264867

  8. Sphingosine-1-phosphate stimulates rat primary chondrocyte proliferation

    SciTech Connect

    Kim, Mi-Kyoung; Lee, Ha Young; Kwak, Jong-Young; Park, Joo-In; Yun, Jeanho; Bae, Yoe-Sik . E-mail: yoesik@donga.ac.kr

    2006-06-23

    Rat primary chondrocytes express the sphingosine-1-phosphate (S1P) receptor, S1P{sub 2}, S1P{sub 3}, S1P{sub 4}, but not S1P{sub 1}. When chondrocytes were stimulated with S1P or phytosphingosine-1-phosphate (PhS1P, an S1P{sub 1}- and S1P{sub 4}-selective agonist), phospholipase C-mediated cytosolic calcium increase was dramatically induced. S1P and PhS1P also stimulated two kinds of mitogen-activated protein kinases, extracellular signal-regulated kinase (ERK) and p38 kinase in chondrocytes. In terms of the two phospholipids-mediated functional modulation of chondrocytes, S1P and PhS1P stimulated cellular proliferation. The two phospholipids-induced chondrocyte proliferations were almost completely blocked by PD98059 but not by SB203580, suggesting that ERK but not p38 kinase is essentially required for the proliferation. Pertussis toxin almost completely inhibited the two phospholipids-induced cellular proliferation and ERK activation, indicating the crucial role of G{sub i} protein. This study demonstrates the physiological role of two important phospholipids (S1P and PhS1P) on the modulation of rat primary chondrocyte proliferation, and the crucial role played by ERK in the process.

  9. TRIB2 regulates normal and stress-induced thymocyte proliferation

    PubMed Central

    Liang, Kai Ling; O’Connor, Caitriona; Veiga, J Pedro; McCarthy, Tommie V; Keeshan, Karen

    2016-01-01

    TRIB2, a serine/threonine pseudokinase identified as an oncogene, is expressed at high levels in the T-cell compartment of hematopoiesis. The proliferation of developing thymocytes is tightly controlled to prevent leukemic transformation of T cells. Here we examine Trib2 loss in murine hematopoiesis under steady state and proliferative stress conditions, including genotoxic and oncogenic stress. Trib2−/− developing thymocytes show increased proliferation, and Trib2−/− mice have significantly higher thymic cellularity at steady state. During stress hematopoiesis, Trib2−/− developing thymocytes undergo accelerated proliferation and demonstrate hypersensitivity to 5-fluorouracil (5-FU)-induced cell death. Despite the increased cell death post 5-FU-induced proliferative stress, Trib2−/− mice exhibit accelerated thymopoietic recovery post treatment due to increased cell division kinetics of developing thymocytes. The increased proliferation in Trib2−/− thymocytes was exacerbated under oncogenic stress. In an experimental murine T-cell acute lymphoblastic leukemia (T-ALL) model, Trib2−/− mice had reduced latency in vivo, which associated with impaired MAP kinase (MAPK) activation. High and low expression levels of Trib2 correlate with immature and mature subtypes of human T-ALL, respectively, and associate with MAPK. Thus, TRIB2 emerges as a novel regulator of thymocyte cellular proliferation, important for the thymopoietic response to genotoxic and oncogenic stress, and possessing tumor suppressor function. PMID:27462446

  10. Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation.

    PubMed

    Yu, Lingling; Zhao, Yingmin; Gu, Xin; Wang, Jijun; Pang, Lei; Zhang, Yanqing; Li, Yaoyao; Jia, Xiaoqin; Wang, Xin; Gu, Jian; Yu, Duonan

    2016-06-10

    Modification of the bone marrow microenvironment is considered as a promising strategy to control leukemic cell proliferation, diseases progression and relapse after treatment. However, due to the diversity and complexity of the cellular and molecular compartments in the leukemic microenvironment, it is extremely difficult to dissect the role of each individual molecule or cell type in vivo. Here we established an in vitro system to dissect the role of lipopolysaccharide (LPS), stromal cells and endothelial cells in the growth of mouse myeloid tumor cells and B-lymphoma cells. We found that either LPS or bone marrow stromal cells as a feeder layer in culture is required for the proliferation of myeloid tumor cells. Surprisingly, the growth of myeloid leukemic cells on stromal cells is strongly inhibited when coupled with LPS in culture. This opposing effect of LPS, a complete switch from pro-proliferation to antitumor growth is due, at least in part, to the rapidly increased production of interleukin 12, Fas ligand and tissue inhibitor of metalloproteinases-2 from stromal cells stimulated by LPS. These results demonstrate that LPS can either facilitate or attenuate tumor cell proliferation, thus changing the disease course of myeloid leukemias through its direct effect or modulation of the tumor microenvironment. PMID:26968634

  11. Studies on the effects of microgravity on the ultrastructure and functions of cultured mammalian cells (L-6)

    NASA Technical Reports Server (NTRS)

    Sato, Atsushige

    1993-01-01

    The human body consists of 10(exp 13) cells. Understanding the mechanisms by which the cells sense and respond to microgravity is very important as the basis for space biology. The cells were originally isolated aseptically from mammalian bodies and cultured in vitro. A set of cell culture vessels was developed to be applied to three kinds of space flight experiments. Experiment 1 is to practice the cell culture technique in a space laboratory and obtain favorable growth of the cells. Aseptic handling in tryspin treatment and medium renewal will be tested. The cells, following space flight, will be returned to the ground and cultured continuously to investigate the effects of space flight on the cellular characteristics. Experiment 2 is to examine the cytoskeletal structure of the cells under microgravity conditions. The cytoskeletal structure plays essential roles in the morphological construction, movements, axonal transport, and differentiation of the cells. The cells fixed during space flight will be returned and the cytoskeleton and ultrastructure observed using electron microscopy and fluorescence microscopy. Experiment 3 is to study the cellular productivity of valuable substances. The waste medium harvested during space flight are returned and quantitated for the cellular products. The effects of microgravity on mammalian cells will be clarified from the various aspects.

  12. Cellular Host Responses to Gliomas

    PubMed Central

    Barish, Michael E.; Garcia, Elizabeth; Metz, Marianne Z.; Myers, Sarah M.; Gutova, Margarita; Frank, Richard T.; Miletic, Hrvoje; Kendall, Stephen E.; Glackin, Carlotta A.; Bjerkvig, Rolf; Aboody, Karen S.

    2012-01-01

    Background Glioblastoma multiforme (GBM) is the most aggressive type of malignant primary brain tumors in adults. Molecular and genetic analysis has advanced our understanding of glioma biology, however mapping the cellular composition of the tumor microenvironment is crucial for understanding the pathology of this dreaded brain cancer. In this study we identified major cell populations attracted by glioma using orthotopic rodent models of human glioma xenografts. Marker-specific, anatomical and morphological analyses revealed a robust influx of host cells into the main tumor bed and tumor satellites. Methodology/Principal Findings Human glioma cell lines and glioma spheroid orthotopic implants were used in rodents. In both models, the xenografts recruited large numbers of host nestin-expressing cells, which formed a ‘network’ with glioma. The host nestin-expressing cells appeared to originate in the subventricular zone ipsilateral to the tumor, and were clearly distinguishable from pericytes that expressed smooth muscle actin. These distinct cell populations established close physical contact in a ‘pair-wise’ manner and migrated together to the deeper layers of tumor satellites and gave rise to tumor vasculature. The GBM biopsy xenografts displayed two different phenotypes: (a) low-generation tumors (first in vivo passage in rats) were highly invasive and non-angiogenic, and host nestin-positive cells that infiltrated into these tumors displayed astrocytic or elongated bipolar morphology; (b) high-generation xenografts (fifth passage) had pronounced cellularity, were angiogenic with ‘glomerulus-like’ microvascular proliferations that contained host nestin-positive cells. Stromal cell-derived factor-1 and its receptor CXCR4 were highly expressed in and around glioma xenografts, suggesting their role in glioma progression and invasion. Conclusions/Significance Our data demonstrate a robust migration of nestin-expressing host cells to glioma, which

  13. Morphogenesis of pestiviruses: new insights from ultrastructural studies of strain Giraffe-1.

    PubMed

    Schmeiser, Stefanie; Mast, Jan; Thiel, Heinz-Jürgen; König, Matthias

    2014-03-01

    Knowledge on the morphogenesis of pestiviruses is limited due to low virus production in infected cells. In order to localize virion morphogenesis and replication sites of pestiviruses and to examine intracellular virion transport, a cell culture model was established to facilitate ultrastructural studies. Based on results of virus growth kinetic analysis and quantification of viral RNA, pestivirus strain Giraffe-1 turned out to be a suitable candidate for studies on virion generation and export from culture cells. Using conventional transmission electron microscopy and single-tilt electron tomography, we found virions located predominately in the lumen of the endoplasmic reticulum (ER) in infected cells and were able to depict the budding process of virions at ER membranes. Colocalization of the viral core protein and the envelope glycoprotein E2 with the ER marker protein disulfide isomerase (PDI) was demonstrated by immunogold labeling of cryosections. Moreover, pestivirions could be shown in transport vesicles and the Golgi complex and during exocytosis. Interestingly, viral capsid protein and double-stranded RNA (dsRNA) were detected in multivesicular bodies (MVBs), which implies that the endosomal compartment plays a role in pestiviral replication. Significant cellular membrane alterations such as those described for members of the Flavivirus and Hepacivirus genera were not found. Based on the gained morphological data, we present a consistent model of pestivirus morphogenesis. PMID:24352462

  14. Ultrastructural and phenotypic characterization of CABA I, a new human ovarian cancer cell line.

    PubMed

    Dolo, V; Ginestra, A; Violini, S; Miotti, S; Festuccia, C; Miceli, D; Migliavacca, M; Rinaudo, C; Romano, F M; Brisdelli, F; Canevari, S; Pavan, A; Vittorelli, M L

    1997-01-01

    We have established an ovarian cancer cell line (CABA I) from ascitic fluid obtained from a patient with papillary adenocarcinoma of the ovary prior to drug treatment. The epithelial origin of the cell line was confirmed by morphology and by immunofluorescence analysis using anticytokeratin antibodies. Ultrastructural analysis revealed a very irregular membrane surface and a clear cytoplasm rich in electron-lucent vesicles. CABA I cells grow rapidly in culture (doubling time 18 h) in an anchorage-independent manner. Exogenously added beta-estradiol and epidermal growth factor (EGF) treatments did not influence cell growth rate. FACS analysis to determine the phenotypic profile of tumor-associated antigen, membrane receptor, and adhesion molecule expression indicated that the cell line was positive for different members of the c-erbB family, for alpha 6 and beta 1 integrin receptors, and intensively positive for HLA class I antigens and the folate receptor. Molecular characterization revealed no mutations for c-myc and c-k-ras genes, but did detect an exon 5 mutation in the p53 gene. CABA I cells grew poorly as heterotransplants in nude mice, and tumors showed long latency periods. Because early (15-20) and late (55-60) passage cells maintain the same growth and phenotypic characteristics, the CABA I cell line might provide a good in vitro model system to investigate the cellular and molecular events involved in ovarian carcinogenesis. PMID:9220498

  15. Immunophenotypic, immunocytochemistry, ultrastructural, and cytogenetic characterization of mesenchymal stem cells from equine bone marrow.

    PubMed

    Maia, Leandro; Landim-Alvarenga, Fernanda C; Da Mota, Ligia S L Silveira; De Assis Golim, Marjorie; Laufer-Amorim, Reneé; De Vita, Bruna; Barberini, Danielle Jaqueta; Listoni, Amanda Jeronimo; De Moraes, Carolina Nogueira; Heckler, Marta Cristina Thomas; Amorim, Rogério Martins

    2013-06-01

    The aim of this study was to isolate, culture, and characterize mesenchymal stem cells (MSCs) from horse bone marrow (BM) using the techniques of flow cytometry, immunocytochemistry, cytogenetics, and electron microscopy. Immunophenotypic analysis revealed the presence of MSCs with high expression of the CD90 marker, lower expression of the CD44 marker, and absent expression of the CD34 marker. In assays of differentiation, the positive response to osteogenic (OST), chondrogenic (CDG), and adipogenic (ADP) differentiation signals was observed and characterized by deposition of calcium-rich extracellular matrix (OST), proteoglycans and collagen II (CDG) and intracellular deposition of fat drops (ADP). In immunocytochemical characterization, MSCs were immunopositive for CD44, vimentin, and PCNA, and they were negative for CD13. In the ultrastructural analysis of MSCs, the most outstanding characteristic was the presence of rough endoplasmic reticulum with very dilated cisterns filled with a low electrodensity material. Additionally, MSCs had normal karyotypes (2n = 64) as evidenced by cytogenetic analysis, and aneuploidy in metaphase was not observed. The protocols for isolating, culturing, and characterizing equine MSCs used in this study were shown to be appropriate for the production of a cell population with a good potential for differentiation and without aneuploidy that can be used to study future cellular therapies. PMID:23533133

  16. New ultrastructural analysis of the invasive apparatus of the Plasmodium ookinete.

    PubMed

    Patra, Kailash P; Vinetz, Joseph M

    2012-09-01

    Invasion of the mosquito midgut by the Plasmodium ookinete determines the success of transmission of malaria parasites from humans to mosquitoes and therefore, is a potential target for molecular intervention. Here, we show higher-resolution ultrastructural details of developing and mature P. gallinaceum ookinetes than previously available. Improved fixation and processing methods yielded substantially improved transmission electron micrographs of ookinetes, particularly with regard to visualization of subcellular secretory and other organelles. These new images provide new insights into the synthesis and function of vital invasive machinery focused on the following features: apical membrane protrusions presumptively used for attachment and protein secretion, dark spherical bodies at the apical end of the mature ookinete, and the presence of a dense array of micronemes apposed to microtubules at the apical end of the ookinete involved in constitutive secretion. This work advances understanding of the molecular and cellular details of the Plasmodium ookinete and provides the basis of future, more detailed mechanistic experimentation on the biology of the Plasmodium ookinete. PMID:22802443

  17. Ultrastructural immunolocalization of dentin matrix protein 1 on Sharpey's fibers in monkey tooth cementum.

    PubMed

    Sawada, T; Ishikawa, T; Shintani, S; Yanagisawa, T

    2012-07-01

    Despite the importance of dentin matrix protein 1 (DMP1) in the formation of mineralized tissue, including dentinogenesis and osteogenesis, its precise role in cementogenesis remains to be clarified fully. The purpose of our study was to demonstrate the ultrastructural immunolocalization of DMP1 in monkey molar tooth cementum. Japanese Macaca fuscata monkeys were fixed by perfusion. The upper molar teeth and accompanying periodontium then were dissected and demineralized with EDTA. Cryosections were obtained, incubated in anti-DMP1 polyclonal antibody, and processed by immunoperoxidase and immunogold labeling. Intense immunoperoxidase staining for DMP1 was observed in acellular extrinsic fiber cementum, particularly in Sharpey's fibers. Cementocyte lacunae with canaliculi showed DMP1 staining in the apical region of the tooth root. Electron immunomicroscopy revealed the close proximity of DMP1 to collagen fibrils in Sharpey's fibers at the mineralization front. Intense immunogold labeling was localized on the walls of the cementocyte lacunae in cellular cementum. These results should contribute to better understanding of the role of DMP1, not only in Sharpey's fiber biomineralization, but also in the maintenance of the cementocyte lacunar space in cementum. PMID:22435407

  18. Morphogenesis of Pestiviruses: New Insights from Ultrastructural Studies of Strain Giraffe-1

    PubMed Central

    Mast, Jan; Thiel, Heinz-Jürgen; König, Matthias

    2014-01-01

    Knowledge on the morphogenesis of pestiviruses is limited due to low virus production in infected cells. In order to localize virion morphogenesis and replication sites of pestiviruses and to examine intracellular virion transport, a cell culture model was established to facilitate ultrastructural studies. Based on results of virus growth kinetic analysis and quantification of viral RNA, pestivirus strain Giraffe-1 turned out to be a suitable candidate for studies on virion generation and export from culture cells. Using conventional transmission electron microscopy and single-tilt electron tomography, we found virions located predominately in the lumen of the endoplasmic reticulum (ER) in infected cells and were able to depict the budding process of virions at ER membranes. Colocalization of the viral core protein and the envelope glycoprotein E2 with the ER marker protein disulfide isomerase (PDI) was demonstrated by immunogold labeling of cryosections. Moreover, pestivirions could be shown in transport vesicles and the Golgi complex and during exocytosis. Interestingly, viral capsid protein and double-stranded RNA (dsRNA) were detected in multivesicular bodies (MVBs), which implies that the endosomal compartment plays a role in pestiviral replication. Significant cellular membrane alterations such as those described for members of the Flavivirus and Hepacivirus genera were not found. Based on the gained morphological data, we present a consistent model of pestivirus morphogenesis. PMID:24352462

  19. Effects of gamma irradiation on the midgut ultrastructure of Glossina palpalis subspecies

    SciTech Connect

    Stiles, J.K.; Molyneux, D.H.; Wallbanks, K.R.; Van der Vloedt, A.M.

    1989-05-01

    In the sterile insect technique, insects are sterilized prior to release in areas where they are pests. The sterile males compete for and with fertile wild individuals for mates, thus reducing the population's reproductive rate. Tsetse fly (Glossina spp.) populations have been eradicated after release of laboratory-bred flies sterilized by gamma irradiation. However, no studies exist on radiation-induced damage to the midgut morphology and function of the radiation-sterilized insects. After G. palpalis palpalis and G. p. gambiensis were subjected to 130 Gy gamma radiation, their midgut damage and recovery were monitored by electron microscopy. The first sign of damage was atrophy and loss of the microvillous border from epithelial cells. The rate of cell degeneration increased, with young as well as old cells being affected and cellular debris filling the ectoperitrophic space. Muscle cells were destroyed, patches of basal lamina were left bare, intracellular virus- and rickettsia-like organisms became more frequent, and many replacement cells became unusually large. Partial recovery occurred from the 10th day postirradiation. Such changes in midgut ultrastructure and the corresponding inhibition of functions may increase the susceptibility of the fly to trypanosome infection.

  20. Morphological and ultrastructural analysis of Turritopsis nutricula during life cycle reversal.

    PubMed

    Carla', E C; Pagliara, P; Piraino, S; Boero, F; Dini, L

    2003-06-01

    The hydrozoa life cycle is characterized, in normal conditions, by the alternation of a post-larval benthic polyp and an adult pelagic medusa; however, some species of Hydrozoa react to environmental stress by reverting their life cycle: i.e. an adult medusa goes back to the juvenile stage of polyp. This very uncommon life cycle could be considered as some sort of inverted metamorphosis. A morphological study of different stages during the reverted life cycle of Turritopsis nutricula led to the characterization of four different stages: healthy medusa, unhealthy medusa, four-leaf clover and cyst. The ultrastructural study of the cellular modifications (during the life cycle reversion of T. nutricula) showed the presence of both degenerative and apoptotic processes. Degeneration was prevalent during the unhealthy medusa and four-leaf clover stages, while the apoptotic rate was higher during the healthy medusa and cyst stages. The significant presence of degenerative and apoptotic processes could be related to the occurrence of a sort of metamorphosis when an adult medusa transforms itself into a polyp. PMID:12798130

  1. Immunomodulation of vascular endothelium. 1. Ultrastructural changes following ultraviolet B irradiation of peripheral veins

    SciTech Connect

    Marin, M.L.; Gordon, R.E.; Hardy, M.A.; Reemtsma, K.; Benvenisty, A.I. )

    1990-02-01

    Immunologic function of endothelial cells is especially important in consideration of vein allografting for arterial reconstruction and in organ allotransplantation. Ultraviolet B radiation (UVB) has previously been shown to modulate graft immunogenicity, and to alter cell surface receptor function. In this study, superficial epigastric veins were UVB irradiated with 10, 24, 40, 80, and 150 mJ/cm2 while control veins were not irradiated; all specimens were examined for endothelial ultrastructural changes. Veins were perfuse-fixed at 1, 3, 7, 14, and 28 days after irradiation, and were evaluated by transmission electron microscopy and scanning electron microscopy. Control veins had a normal appearing endothelial lining, composed of elongated, attenuated endothelial cells. Veins irradiated with more than 24 mJ/cm2 displayed injured endothelial cells characterized by altered microvilli, defects in the cell surface, and a change in cell shape. The degree of cell damage correlated closely with increasing UVB dose. At doses of 80 mJ/cm2 or greater there was moderate to severe endothelial cell separation from the underlying basement membrane and an increase in cellular lysosomes. The effects of UVB were maximal at 3 days with virtual recovery in resurfacing of all specimens with endothelium 28 days after irradiation. These data suggest that UVB has a dose-dependent effect on venous endothelium that is morphologically reversible with time. Cell membrane changes seen following exposure to UVB may contribute to altered cell surface receptor function.

  2. ULTRASTRUCTURAL EVALUATION OF THE RADIOPROTECTIVE EFFECT OF SODIUM SELENITE ON SUBMANDIBULAR GLANDS IN RATS

    PubMed Central

    Pontual, Maria Luiza dos Anjos; Tuji, Fabrício Mesquita; Barros, Silvana Pereira; Bóscolo, Frab Norberto; Novaes, Pedro Duarte; de Almeida, Solange Maria

    2007-01-01

    The aim of this study was to evaluate the radioprotector effect of sodium selenite on the ultrastructure of submandibular glands in rats. Fifty-seven male albino Wistar rats were randomized to 4 groups: control, irradiated, sodium selenite and irradiated/sodium selenite. The animals in the sodium selenite and irradiated/sodium selenite groups received intraperitoneal injections of sodium selenite (0.5 mg/kg body weight) 24 h before irradiation. The animals belonging to the irradiated and irradiated/sodium selenite groups were submitted to 15 Gy of gamma radiation in the head and neck region. The submandibular glands were removed at 4, 8, 12, 24, 48 and 72 h after irradiation. The ionizing radiation induced damage to the secretory cells, especially the serous cells, right from the first period. Vacuolization, lysis of cytoplasmic inclusions and nuclear alterations occurred. The sodium selenite group also presented cellular alterations in the study periods, but with less damage compared to that caused by radiation. There was greater similarity between the irradiated/sodium selenite group and the control group than with the other groups treated in all study periods. Despite the alterations observed in the sodium selenite group, sodium selenite presented a radioprotective action on the secretory cells of submandibular glands. PMID:19089124

  3. Effects of gamma irradiation on the midgut ultrastructure of Glossina palpalis subspecies.

    PubMed

    Stiles, J K; Molyneux, D H; Wallbanks, K R; Van der Vloedt, A M

    1989-05-01

    In the sterile insect technique, insects are sterilized prior to release in areas where they are pests. The sterile males compete for and with fertile wild individuals for mates, thus reducing the population's reproductive rate. Tsetse fly (Glossina spp.) populations have been eradicated after release of laboratory-bred flies sterilized by gamma irradiation. However, no studies exist on radiation-induced damage to the midgut morphology and function of the radiation-sterilized insects. After G. palpalis palpalis and G. p. gambiensis were subjected to 130 Gy gamma radiation, their midgut damage and recovery were monitored by electron microscopy. The first sign of damage was atrophy and loss of the microvillous border from epithelial cells. The rate of cell degeneration increased, with young as well as old cells being affected and cellular debris filling the ectoperitrophic space. Muscle cells were destroyed, patches of basal lamina were left bare, intracellular virus- and rickettsia-like organisms became more frequent, and many replacement cells became unusually large. Partial recovery occurred from the 10th day postirradiation. Such changes in midgut ultrastructure and the corresponding inhibition of functions may increase the susceptibility of the fly to trypanosome infection. PMID:2727263

  4. Survival and ultrastructure of gene-microinjected rabbit embryos after vitrification.

    PubMed

    Popelková, M; Chrenek, P; Pivko, J; Makarevich, A V; Kubovicová, E; Kacmárik, J

    2005-11-01

    Morphological signs of injury and subsequent regeneration following vitrification of either rabbit gene microinjected (Gene-Mi) or intact in vitro cultured embryos derived from in vivo fertilized eggs were evaluated by post-warming recovery in culture and analysed by transmission electron microscopy (TEM). The percentages of vitrified/warmed Gene-Mi embryos that reached the blastocyst stage (69%) and hatched (57%) did not differ significantly from those of intact embryos (78% and 56%, respectively). In contrast, in vitro development of embryos to the blastocyst stage among non-vitrified intact (96%) and Gene-Mi (90%) embryos compared with both the intact vitrified (78%) and Gene-Mi vitrified (69%) groups, as well as hatching rate (94%, 90% vs 56%, 57%, respectively) varied significantly (p < 0.001). Observations by TEM showed that the vitrified/warmed intact or Gene-Mi embryos without post-culture displayed severe degenerative changes among their cells. During 24 h of culture a proportion of the embryos were able to regenerate and complete the compaction process. Nevertheless the signs of previous injury were retained, such as swollen cytoplasmic organelles and remaining cellular debris in the perivitelline space. These observations indicate that the procedure of gene Mi does not significantly compromise embryo tolerance to cryopreservation and post-warming developmental ability. Severe changes in embryo morphology, observed at the ultrastructural level, can be attributed to a direct influence of the vitrification process rather than to the Mi procedure itself. PMID:16388696

  5. Ultrastructure of tracheal epithelial cells migrating in an in vivo environment.

    PubMed

    Sawada, Hajime; Tanaka, Hideo; Ono, Michio

    2008-12-01

    The tracheal epithelium can be induced to move as a cellular sheet by heterotopic transplantation, which offers the opportunity to observe migrating cells as a group in an in vivo environment. We therefor investigated the ultrastructural characteristics of migrating tracheal epithelial cells with special reference to the moving front using this transplantation. The migrating epithelial cells underwent squamous metaplasia and lost their differentiated characteristics such as cilia or secretory granules. Several unique observations were made concerning the mechanism of mobility: one is that epithelial cells in the front were elongated in a direction perpendicular to the course of movement, different from previous reports in vitro. The second is that lamellipodia, which are regarded as the major locomotive machinery in the adult wound epithelium, did not make up the major part of the front; the major portion of the anterior fringe of the moving front was usually smooth and gently curved, and actin cables parallel to the elongated cells were observed by confocal laser microscopy, indicating that the purse-string mechanism of epithelial wound healing takes place. The third finding is that the cells in the front had irregular bleb-like structures on their antero-basal surface, which were formed even in the portion where the cells did not attach to the matrix. Few organelles were recognized in these structures. From their location, one might propose that these bleb-like structures play a role in the recognition of the substrate and thus the movement of the cell sheet. PMID:19359805

  6. Correlative light and electron microscopy enables viral replication studies at the ultrastructural level.

    PubMed

    Hellström, Kirsi; Vihinen, Helena; Kallio, Katri; Jokitalo, Eija; Ahola, Tero

    2015-11-15

    Electron microscopy (EM) is a powerful tool to study structural changes within cells caused e.g. by ectopic protein expression, gene silencing or virus infection. Correlative light and electron microscopy (CLEM) has proven to be useful in cases when it is problematic to identify a particular cell among a majority of unaffected cells at the EM level. In this technique the cells of interest are first identified by fluorescence microscopy and then further processed for EM. CLEM has become crucial when studying positive-strand RNA virus replication, as it takes place in nanoscale replication sites on specific cellular membranes. Here we have employed CLEM for Semliki Forest virus (SFV) replication studies both by transfecting viral replication components to cells or by infecting different cell types. For the transfection-based system, we developed an RNA template that can be detected in the cells even in the absence of replication and thus allows exploration of lethal mutations in viral proteins. In infected mammalian and mosquito cells, we were able to find replication-positive cells by using a fluorescently labeled viral protein even in the cases of low infection efficiency. The fluorescent region within these cells was shown to correspond to an area rich in modified membranes. These results show that CLEM is a valuable technique for studying virus replication and membrane modifications at the ultrastructural level. PMID:25916619

  7. Cystosarcoma phylloides of the breast and its mimics. An immunohistochemical and ultrastructural study.

    PubMed

    Auger, M; Hanna, W; Kahn, H J

    1989-11-01

    Cystosarcoma phylloides of the breast is a tumor composed of breast ducts and a cellular stromal component that can be benign or malignant. The origin of the stromal cells is controversial. We undertook an immunohistochemical and ultrastructural study of 11 cases of cystosarcoma phylloides to assess the histogenesis of the stromal component. By light microscopy, 4 were diagnosed as benign, and 7 were diagnosed as malignant. Antibodies to vimentin, desmin, actin, high- and low-molecular-weight keratins, and S100 protein were used for immunohistochemical staining. In the 4 benign cases of cystosarcoma phylloides, the stromal cells stained positively only for vimentin. In the malignant tumors, the spindle cell component stained for vimentin in all the cases. In addition, the malignant stromal cells coexpressed desmin in two cases and keratin and S 100 protein in another case. By electron microscopy the stromal component in the benign case and in two of five malignant cases was composed of a mixture of fibroblasts and myofibroblasts. The entire neoplastic stroma in two other malignant cases showed features of smooth-muscle differentiation, whereas in another case all the stromal cells showed myoepithelial differentiation. Thus, in benign and malignant cystosarcoma phylloides, the stromal component consists of a mixture of fibroblasts and myofibroblasts. Leiomyosarcomas and myoepitheliomas can mimic malignant cystosarcoma phylloides, but immunohistochemistry and electron microscopy can differentiate these entities. This is important since their biologic behavior is different. PMID:2554842

  8. Effects of di-n-butyl phthalate on the physiology and ultrastructure of cucumber seedling roots.

    PubMed

    Zhang, Ying; Tao, Yue; Sun, Guoqiang; Wang, Lei

    2014-05-01

    Agricultural pollution caused by the use of plastic sheetings has been documented to be a widespread problem in most of the major crop-planting regions of the world. In order to better understand the phytotoxic mechanisms induced by phthalic acid esters involved with this problem, Cucumber sativus L. cv Jinyan No. 4 were sown in pots to the three-leaf-stage in the presence of di-n-butyl phthalate (DBP; 0, 30, 50, 100, and 200 mg L(-1)) for 1, 3, 5, or 7 days. Physiology, biochemistry, and ultrastructure of seedling roots were examined. The results indicated that activities of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) were stimulated at low-DBP treatments and decreased under higher levels (>100 mg L(-1)) compared to the controls. On the other hand, SOD and POD provided a better defense against DBP-induced oxidative damage in the roots of cucumber seeding, compared to CAT. The productions of both malondialdehyde (MDA) and proline (Pro) were promoted under DBP stress. Visible impact on the cytoderm, mitochondrion, and vacuole was detected, possibly as a consequence of free radical generation. These results suggested that activation of the antioxidant system by DBP led to the formation of reactive oxygen species that resulted in cellular damage. PMID:24573460

  9. Ultrastructural alterations in the gills of Labeo rohita fingerlings exposed to thermal extremes.

    PubMed

    Das, T; Sahu, N P; Chakraborty, S K; Chatterjee, N; Mohammed, M S; Dalvi, R S; Baruah, K; Pal, A K

    2014-02-01

    This study aimed to determine the cellular alterations in the gill of Labeo rohita exposed to lethal temperature maxima (LTM ax ) and lethal temperature minima (LTM in ) by means of transmission electron microscopy (TEM). Acclimation of advanced fingerlings of L. rohita was carried out at 26°C for 30 days. Acclimated fish were subjected to a constant rate of increase or decrease in temperature (0.3°C/min) until the LTM ax and LTM in values were reached. Dissected gills were processed for TEM, both at the end of acclimation period at ambient temperature (26°C) and at lethal temperatures. Results indicated that at ambient temperature, the gill tissues appeared normal. However, significant changes were observed at lethal temperatures. The gill tissues at lethal temperature maxima showed severely damaged lamellae, with more vacuolated space. At lethal temperature minima, gill tissues showed increased density of mitochondria. Our prima-facie report indicated that L. rohita exposed to lethal temperatures exhibited marked ultrastructural changes in the gills. PMID:23480531

  10. Inducing cellular senescence using defined genetic elements.

    PubMed

    Nakagawa, Hiroshi; Opitz, Oliver G

    2007-01-01

    Cellular senescence is generally defined as an irreversible state of G1 cell cycle arrest in which cells are refractory to growth factor stimulation. Cellular senescence can be induced through several different mechanisms. Primary mammalian cells display a finite life span, suggesting a mechanism that counts cell divisions. Those cells initially proliferate but eventually enter a state of permanent growth arrest, called replicative senescence. Erosion of telomeric DNA has emerged as a key factor in replicative senescence, which is antagonized during cell immortalization. Nevertheless, besides telomere shortening, there are other mechanisms inducing a growth arrest similar to the replicative senescencent phenotype. Oncogenic or mitogenic signals as well as DNA damage can induce such a phenotype of cellular senescence. All forms of cellular senescence share common signaling pathways and morphological features. Thereby, p53 seems to be essential for the senescence response. Many of these senescence inducing mechanisms can be experimentally recapitulated by the introduction of defined genetic elements. Replicative senescence due to telomere shortening can, for example, be induced by a dominant negative version of telomerase, premature senescence by the overexpression of oncogenic ras, or p16. PMID:17634581

  11. The nucleolar structure and nucleolar proteins in proliferating cells of Arabidopsis seeds germinated in the International Space Station

    NASA Astrophysics Data System (ADS)

    Matía, I.; González-Camacho, F.; Marco, R.; Kiss, J. Z.; Gasset, G.; Medina, F. J.

    Seeds of Arabidopsis thaliana were sent to the ISS in the ``Cervantes Mission'' (Spanish Soyuz Mission) within MAMBA Biocontainers (Dutch Space B.V.). These Biocontainers are capable of supplying liquids to the biosample by means of a motorized mechanism based on the ``Berlingot-Ampoule'' concept. Seed germination was activated by supplying culture medium to them, and the process progressed for 4 days at 22°C. Then, growth was stopped by the addition of paraformaldehyde (PFA) fixative. Once back on the ground, samples were immediately processed for microscopical observation. A parallel ground control experiment was simultaneously replicated, following the same schedule and conditions. Seed germination occurred at a high rate in the Space. No differences in the germination rate were observed with respect to the ground control, although Space-grown seedlings were substantially longer (affecting the roots and also the hypocotyl) than the parallel samples grown at 1 g. The mitotic index and the cellular morphometric parameters (length, width, nuclear size) were measured and compared in both the experimental and control conditions. Bidimensional protein electrophoresis was performed on samples in which PFA fixation was reverted by prolonged (two weeks) storage in PBS buffer. The total proteomic profile of seedlings showed differences between the Space sample and the ground control, affecting to nearly one third of the spots. Remarkably, a set of spots around 35 kDa and pI 8.0 are conspicuous in the Space sample and do not appear in the ground control. A more specialized proteomic analysis, with functional significance, was carried out using the AgNOR staining method on Western blots, a technique revealing nucleolar proteins associated with cell proliferation. Immunocytochemical experiments showed the in situ distribution of nucleolin, a nucleolar multifunctional protein regulated by kinases related with cell cycle and proliferation control mechanisms. Finally, the

  12. Ultrastructural alterations of Erwinia carotovora subsp. atroseptica caused by treatment with aluminum chloride and sodium metabisulfite.

    PubMed

    Yaganza, Elian-Simplice; Rioux, Danny; Simard, Marie; Arul, Joseph; Tweddell, Russell J

    2004-11-01

    Aluminum and bisulfite salts inhibit the growth of several fungi and bacteria, and their application effectively controls potato soft rot caused by Erwinia carotovora. In an effort to understand their inhibitory action, ultrastructural changes in Erwinia carotovora subsp. atroseptica after exposure (0 to 20 min) to different concentrations (0.05, 0.1, and 0.2 M) of these salts were examined by using transmission electron microscopy. Plasma membrane integrity was evaluated by using the SYTOX Green fluorochrome that penetrates only cells with altered membranes. Bacteria exposed to all aluminum chloride concentrations, especially 0.2 M, exhibited loosening of the cell walls, cell wall rupture, cytoplasmic aggregation, and an absence of extracellular vesicles. Sodium metabisulfite caused mainly a retraction of plasma membrane and cellular voids which were more pronounced with increasing concentration. Bacterial mortality was closely associated with SYTOX stain absorption when bacteria were exposed to either a high concentration (0.2 M) of aluminum chloride or prolonged exposure (20 min) to 0.05 M aluminum chloride or to a pH of 2.5. Bacteria exposed to lower concentrations of aluminum chloride (0.05 and 0.1 M) for 10 min or less, or to metabisulfite at all concentrations, did not exhibit significant stain absorption, suggesting that no membrane damage occurred or it was too weak to allow the penetration of the stain into the cell. While mortality caused by aluminum chloride involves membrane damage and subsequent cytoplasmic aggregation, sulfite exerts its effect intracellularly; it is transported across the membrane by free diffusion of molecular SO2 with little damage to the cellular membrane. PMID:15528547

  13. Initiatives for proliferation prevention

    SciTech Connect

    1997-04-01

    Preventing the proliferation of weapons of mass destruction is a central part of US national security policy. A principal instrument of the Department of Energy`s (DOE`s) program for securing weapons of mass destruction technology and expertise and removing incentives for scientists, engineers and technicians in the newly independent states (NIS) of the former Soviet Union to go to rogue countries or assist terrorist groups is the Initiatives for Proliferation Prevention (IPP). IPP was initiated pursuant to the 1994 Foreign Operations Appropriations Act. IPP is a nonproliferation program with a commercialization strategy. IPP seeks to enhance US national security and to achieve nonproliferation objectives by engaging scientists, engineers and technicians from former NIS weapons institutes; redirecting their activities in cooperatively-developed, commercially viable non-weapons related projects. These projects lead to commercial and economic benefits for both the NIS and the US IPP projects are funded in Russian, Ukraine, Kazakhstan and Belarus. This booklet offers an overview of the IPP program as well as a sampling of some of the projects which are currently underway.

  14. Peroxisome proliferator-activated receptor {alpha}-independent peroxisome proliferation

    SciTech Connect

    Zhang Xiuguo; Tanaka, Naoki . E-mail: naopi@hsp.md.shinshu-u.ac.jp; Nakajima, Takero; Kamijo, Yuji; Gonzalez, Frank J.; Aoyama, Toshifumi

    2006-08-11

    Hepatic peroxisome proliferation, increases in the numerical and volume density of peroxisomes, is believed to be closely related to peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) activation; however, it remains unknown whether peroxisome proliferation depends absolutely on this activation. To verify occurrence of PPAR{alpha}-independent peroxisome proliferation, fenofibrate treatment was used, which was expected to significantly enhance PPAR{alpha} dependence in the assay system. Surprisingly, a novel type of PPAR{alpha}-independent peroxisome proliferation and enlargement was uncovered in PPAR{alpha}-null mice. The increased expression of dynamin-like protein 1, but not peroxisome biogenesis factor 11{alpha}, might be associated with the PPAR{alpha}-independent peroxisome proliferation at least in part.

  15. Cellular Homeostasis and Aging.

    PubMed

    Hartl, F Ulrich

    2016-06-01

    Aging and longevity are controlled by a multiplicity of molecular and cellular signaling events that interface with environmental factors to maintain cellular homeostasis. Modulation of these pathways to extend life span, including insulin-like signaling and the response to dietary restriction, identified the cellular machineries and networks of protein homeostasis (proteostasis) and stress resistance pathways as critical players in the aging process. A decline of proteostasis capacity during aging leads to dysfunction of specific cell types and tissues, rendering the organism susceptible to a range of chronic diseases. This volume of the Annual Review of Biochemistry contains a set of two reviews addressing our current understanding of the molecular mechanisms underlying aging in model organisms and humans. PMID:27050288

  16. Architected Cellular Materials

    NASA Astrophysics Data System (ADS)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  17. Irregular Cellular Learning Automata.

    PubMed

    Esnaashari, Mehdi; Meybodi, Mohammad Reza

    2015-08-01

    Cellular learning automaton (CLA) is a recently introduced model that combines cellular automaton (CA) and learning automaton (LA). The basic idea of CLA is to use LA to adjust the state transition probability of stochastic CA. This model has been used to solve problems in areas such as channel assignment in cellular networks, call admission control, image processing, and very large scale integration placement. In this paper, an extension of CLA called irregular CLA (ICLA) is introduced. This extension is obtained by removing the structure regularity assumption in CLA. Irregularity in the structure of ICLA is needed in some applications, such as computer networks, web mining, and grid computing. The concept of expediency has been introduced for ICLA and then, conditions under which an ICLA becomes expedient are analytically found. PMID:25291810

  18. Histopathological, Ultrastructural and Apoptotic Changes in Diabetic Rat Placenta

    PubMed Central

    Gül, Mehmet; Bayat, Nuray; Çetin, Aslı; Kepekçi, Remziye Aysun; Şimşek, Yavuz; Kayhan, Başak; Turhan, Uğur; Otlu, Ali

    2015-01-01

    Background: The exchange of substances between mother and fetus via the placenta plays a vital role during development. A number of developmental disorders in the fetus and placenta are observed during diabetic pregnancies. Diabetes, together with placental apoptosis, can lead to developmental and functional disorders. Aims: Histological, ultrastructural and apoptotic changes were investigated in the placenta of streptozotocin (STZ) induced diabetic rats. Study Design: Animal experimentation. Methods: In this study, a total of 12 female Wistar Albino rats (control (n=6) and diabetic (n=6)) were used. Rats in the diabetic group, following the administration of a single dose of STZ, showed blood glucose levels higher than 200 mg/dL after 72 hours. When pregnancy was detected after the rats were bred, two pieces of placenta and the fetuses were collected on the 20th day of pregnancy by cesarean incision under ketamine/ xylazine anesthesia from in four rats from the control and diabetic groups. Placenta tissues were processed for light microscopy and transmission electron microscopy (TEM). Hematoxylin-eosin (HE) and periodic acid Schiff-diastase (PAS-D) staining for light microscopic and caspase-3 staining for immunohistochemical investigations were performed for each placenta. Electron microscopy was performed on thin sections contrasted with uranyl acetate and lead nitrate. Results: Weight gain in the placenta and fetuses of diabetic rats and thinning of the decidual layer, thickening of the hemal membrane, apoptotic bodies, congestion in intervillous spaces, increased PAS-D staining in decidual cells and caspase-3 immunoreactivity were observed in the diabetic group. After the ultrastructural examination, the apoptotic appearance of the nuclei of trophoblastic cells, edema and intracytoplasmic vacuolization, glycogen accumulation, dilation of the endoplasmic reticulum and myelin figures were observed. In addition, capillary basement membrane thickening, capillary

  19. Adult Neurogenesis: Ultrastructure of a Neurogenic Niche and Neurovascular Relationships

    PubMed Central

    Chaves da Silva, Paula Grazielle; Benton, Jeanne L.; Beltz, Barbara S.; Allodi, Silvana

    2012-01-01

    The first-generation precursors producing adult-born neurons in the crayfish (Procambarus clarkii) brain reside in a specialized niche located on the ventral surface of the brain. In the present work, we have explored the organization and ultrastructure of this neurogenic niche, using light-level, confocal and electron microscopic approaches. Our goals were to define characteristics of the niche microenvironment, examine the morphological relationships between the niche and the vasculature and observe specializations at the boundary between the vascular cavity located centrally in the niche. Our results show that the niche is almost fully encapsulated by blood vessels, and that cells in the vasculature come into contact with the niche. This analysis also characterizes the ultrastructure of the cell types in the niche. The Type I niche cells are by far the most numerous, and are the only cell type present superficially in the most ventral cell layers of the niche. More dorsally, Type I cells are intermingled with Types II, III and IV cells, which are observed far less frequently. Type I cells have microvilli on their apical cell surfaces facing the vascular cavity, as well as junctional complexes between adjacent cells, suggesting a role in regulating transport from the blood into the niche cells. These studies demonstrate a close relationship between the neurogenic niche and vascular system in P. clarkii. Furthermore, the specializations of niche cells contacting the vascular cavity are also typical of the interface between the blood/cerebrospinal fluid (CSF)-brain barriers of vertebrates, including cells of the subventricular zone (SVZ) producing new olfactory interneurons in mammals. These data indicate that tissues involved in producing adult-born neurons in the crayfish brain use strategies that may reflect fundamental mechanisms preserved in an evolutionarily broad range of species, as proposed previously. The studies described here extend our understanding of

  20. Cellular and subcellular localization of Marlin-1 in the brain

    PubMed Central

    Vidal, René L; Valenzuela, José I; Luján, Rafael; Couve, Andrés

    2009-01-01

    Background Marlin-1 is a microtubule binding protein that associates specifically with the GABAB1 subunit in neurons and with members of the Janus kinase family in lymphoid cells. In addition, it binds the molecular motor kinesin-I and nucleic acids, preferentially single stranded RNA. Marlin-1 is expressed mainly in the central nervous system but little is known regarding its cellular and subcellular distribution in the brain. Results Here we have studied the localization of Marlin-1 in the rodent brain and cultured neurons combining immunohistochemistry, immunofluorescence and pre-embedding electron microscopy. We demonstrate that Marlin-1 is enriched in restricted areas of the brain including olfactory bulb, cerebral cortex, hippocampus and cerebellum. Marlin-1 is abundant in dendrites and axons of GABAergic and non-GABAergic hippocampal neurons. At the ultrastructural level, Marlin-1 is present in the cytoplasm and the nucleus of CA1 neurons in the hippocampus. In the cytoplasm it associates to microtubules in the dendritic shaft and occasionally with the Golgi apparatus, the endoplasmic reticulum (ER) and dendritic spines. In the nucleus, clusters of Marlin-1 associate to euchromatin. Conclusion Our results demonstrate that Marlin-1 is expressed in discrete areas of the brain. They also confirm the microtubule association at the ultrastructural level in neurons. Together with the abundance of the protein in dendrites and axons they are consistent with the emerging role of Marlin-1 as an intracellular protein linking the cytoskeleton and transport. Our study constitutes the first detailed description of the cellular and subcellular distribution of Marlin-1 in the brain. As such, it will set the basis for future studies on the functional implications of Marlin-1 in protein trafficking. PMID:19386132

  1. The Crossroads of Iron with Hypoxia and Cellular Metabolism. Implications in the Pathobiology of Pulmonary Hypertension

    PubMed Central

    Graham, Brian B.; Rouault, Tracey C.; Tuder, Rubin M.

    2014-01-01

    The pathologic hallmark of pulmonary arterial hypertension (PAH) is pulmonary vascular remodeling, characterized by endothelial cell proliferation, smooth muscle hypertrophy, and perivascular inflammation, ultimately contributing to increased pulmonary arterial pressures. Several recent studies have observed that iron deficiency in patients with various forms of PAH is associated with worsened clinical outcome. Iron plays a key role in many cellular processes regulating the response to hypoxia, oxidative stress, cellular proliferation, and cell metabolism. Given the potential importance of iron supplementation in patients with the disease and the broad cellular functions of iron, we review its role in processes that pertain to PAH. PMID:24988529

  2. Greigite magnetosome membrane ultrastructure in 'Candidatus Magnetoglobus multicellularis'.

    PubMed

    Abreu, Fernanda P; Silva, Karen T; Farina, Marcos; Keim, Carolina N; Lins, Ulysses

    2008-06-01

    The ultrastructure of the greigite magnetosome membrane in the multicellular magnetotactic bacteria 'Candidatus Magnetoglobus multicellularis' was studied. Each cell contains 80 membrane-enclosed iron-sulfide magnetosomes. Cytochemistry methods showed that the magnetosomes are enveloped by a structure whose staining pattern and dimensions are similar to those of the cytoplasmic membrane, indicating that the magnetosome membrane likely originates from the cytoplasmic membrane. Freeze-fracture showed intramembrane particles in the vesicles surrounding each magnetosome. Observations of cell membrane invaginations, the trilaminar membrane structure of immature magnetosomes, and empty vesicles together suggested that greigite magnetosome formation begins by invagination of the cell membrane, as has been proposed for magnetite magnetosomes. PMID:18645957

  3. Knee arthropathy in ochronosis: diagnosis by arthroscopy with ultrastructural features.

    PubMed

    Lurie, D P; Musil, G

    1984-02-01

    Knee arthroscopy in a patient with undiagnosed chronic monoarticular arthritis revealed dark pigmentation of the snyovium; synovial biopsy revealed histologic and ultrastructural features characteristic of ochronosis. Synovial fluid (SF) was non-inflammatory, without pigmented shards of cartilage; calcium pyrophosphate dihydrate crystals were absent in both the SF and biopsy specimen. Homogentisic acid was detectable in the urine by thin layer chromatography, and asymptomatic spondylosis with intervertebral disc calcification was found. The negative family history, lack of mucocutaneous pigmentation and failure of the urine to spontaneously darken obscured the diagnosis, which was easily made by arthroscopy. PMID:6699824

  4. Ulcerative colitis: ultrastructure of interstitial cells in myenteric plexus.

    PubMed

    Rumessen, J J; Vanderwinden, J-M; Horn, T

    2010-10-01

    Interstitial cells of Cajal (ICC) are key regulatory cells in the gut. In the colon of patients with severe ulcerative colitis (UC), myenteric ICC had myoid ultrastructural features and were in close contact with nerve terminals. In all patients as opposed to controls, some ICC profiles showed degenerative changes, such as lipid droplets and irregular vacuoles. Nerve terminals often appeared swollen and empty. Glial cells, muscle cells, and fibroblast-like cells (FLC) showed no alterations. FLC enclosed macrophages (MLC), which were in close contact with naked axon terminals. The organization and cytological changes may be of pathophysiological significance in patients with UC. PMID:20568987

  5. Ultrastructural studies of unstable angina in living man

    SciTech Connect

    Gotlieb, A.I.; Freeman, M.R.; Salerno, T.A.; Lichtenstein, S.V.; Armstrong, P.W. )

    1991-01-01

    Nineteen patients with refractory unstable angina who were undergoing aortocoronary bypass were studied to assess the extent of platelet aggregation present in the microvasculature. Ultrastructural findings on the morphology of cardiac muscle and microvasculature were correlated with the findings on coronary angiograms and thallium scans. There were no significant correlations. The presence of platelet aggregates was identified in four biopsies, two of which had thrombus by angiographic criteria. Biopsy in areas with thallium defects revealed an increased prevalence of white blood cells without acute myocardial infarction. This study confirms the presence of platelet aggregates in patients with unstable angina, albeit at a reduced frequency when compared with autopsy studies.

  6. Lead induced ultrastructural changes in the testis of rats.

    PubMed

    Murthy, R C; Saxena, D K; Gupta, S K; Chandra, S V

    1991-01-01

    Oral lead administration (250 ppm lead acetate through drinking water) to weaning male rats for 70 days resulted in the marked accumulation of this metal in blood and testicular tissue. No marked changes were evident in light microscopy. Ultrastructural changes were revealed in the form of vacuolisation of Sertoli cell cytoplasm and increase in the number and size of lysosomes. Some of the vacuoles contained vesicle like structures. Although there was no impairment of spermatogenesis, the changes in the Sertoli cells may lead to changes in spermatogenesis after chronic exposure. PMID:1879517

  7. Gravity receptors - An ultrastructural basis for peripheral sensory processing

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Donovan, K.

    1984-01-01

    The present ultrastructural study of serial sections has shown that type II hair cells of the anterior part of the utricular macula are integrated into the afferent neural circuitry of type I cells, which are arranged in clusters. Additionally, there exists a complex system of intramacularly originating efferent-type nerve fibers and terminals. The findings, taken together, suggest that on morphological grounds, complex processing of sensory information occurs in gravity receptors. Asymmetry of such a complex system may contribute to motion and space-motion sickness.

  8. Cystosarcoma phylloides. A steroid receptor and ultrastructure analysis.

    PubMed Central

    Kesterson, G H; Georgiade, N; Seigler, H F; Barton, T K; McCarty, K S; McCarty, K S

    1979-01-01

    Six cases of cystosarcoma phylloides were evaluated by ultrastructure and steroid receptor analysis. Electron microscopy of the lesions supported previous reports of a heterogeneous tumor consisting of pleomorphic mesenchyme and normal or proliferative epithelium. In each case estrogen and progesterone receptor analysis indicated the presence of a nonsaturable estrogen and progesterone 4S binding protein rather than a specific steroid receptor as suggested by previous studies. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5A. Fig. 5B. Fig. 6. PMID:228617

  9. Changes in root gravitropism, ultrastructure, and calcium balance of pea root statocytes induced by A23187

    NASA Astrophysics Data System (ADS)

    Belyavskaya, N.

    The role for calcium in the regulation of a wide variety of cellular events in plants is well known. Calcium signaling has been implicated in plant gravitropism. A carboxylic acid antibiotic A23187 (calcimycin) has been widely used in biological studies since it can translocate calcium across membranes. Seedlings of Pisum sativum L. cv. Uladovsky germinated in a vertically oriented cylinder of moist filter paper soaked in water during 4.5 day had been treated with 10-5 M A23187 for 12 hr. Tips of primary roots of control and A23187-treated pea seedlings were fixed for electron microscopy and electron cytochemistry. Experiments with Pisum sativum 5- day seedlings placed horizontally for 4 h after treatment with 10 μM A23187 during 12 h found that the graviresponsiveness of their primary roots was lost completely (91 % of roots) or inhibited (24 +/- 6° in comparison with 88 +/- 8° in control). At ultrastructural level, there were observed distribution of amyloplasts around the nucleus, remarkable lengthening of statocytes, advanced vacuolization, changes in dictyosome structure, ER fragmentation, cell wall thinning in A23187-treated statocytes. Cytochemical study has indicated that statocytes exposed to calcimycin have contained a number of Ca-pyroantimonate granules detected Ca 2 + ions in organelles and hyaloplasm (unlike the control ones). The deposits were mainly associated with the plasma membrane. Among organelles, mitochondria were notable for their ability to accumulate Ca 2 +. In amyloplasts, a fine precipitate was predominately located in their stroma and envelope lumens. In cell walls, deposits of the reaction product were observed along the periphery and in the median zone. Localization of electron-dense granules of lead phosphate, which indicated Ca 2 +- ATPase activities in pea statocytes exposed to A23187, was generally consistent with that in untreated roots. Apart from plasma membrane, chromatin, and nucleolus components, the cytochemical reaction

  10. Axl as a mediator of cellular growth and survival

    PubMed Central

    Axelrod, Haley; Pienta, Kenneth J.

    2014-01-01

    The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context. PMID:25344858

  11. Reversible effect of all-trans-retinoic acid on AML12 hepatocyte proliferation and cell cycle progression

    EPA Science Inventory

    The role of all-trans-retinoic acid (atRA) in the regulation of cellular proliferation and differentiation is well documented. Numerous studies have established the cancer preventive propertiesofatRAwhichfunctionstoregulate levels ofcellcycleproteinsessentialfortheGliS transition...

  12. The changing proliferation threat

    SciTech Connect

    Sopko, J.F.

    1996-12-31

    Technological advances and new adversaries with new motives have reduced the relevancy and effectiveness of the American nonproliferation strategy that was developed during the Cold War. The Cold War`s end and the breakup of the Soviet Union have created new proliferation dangers even as they have reduced others. The familiar balance of nuclear terror that linked the superpowers and their client states for nearly 50 years in a choreographed series of confrontations has given way to a much less predictable situation, where weapons of unthinkable power appear within the grasp of those more willing to use them. Rogue nations and {open_quotes}clientless{close_quotes} states, terrorist groups, religious cults, ethnic minorities, disaffected political groups, and even individuals appear to have jointed a new arms race toward mass destruction. The author describes recent events that suggest the new trends and a serious challenge to US national security.

  13. Genetic Dominance & Cellular Processes

    ERIC Educational Resources Information Center

    Seager, Robert D.

    2014-01-01

    In learning genetics, many students misunderstand and misinterpret what "dominance" means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that…

  14. Teaching cellular engineering.

    PubMed

    Hammer, Daniel A; Waugh, Richard E

    2006-02-01

    Cellular engineering is one of the fastest growing subdisciplines in the field of Biomedical Engineering. It involves the application of engineering analysis to understand and control cellular behavior, with the ultimate objective of developing novel therapeutic or diagnostic approaches for the clinic or harnessing cellular function for commercial applications. Well-educated students in this area need strong foundational knowledge in engineering science, chemistry, and cell and molecular biology. In undergraduate curricula, the challenge is to include essential engineering skills plus appropriate levels of training in chemistry and biology while satisfying accreditation-mandated breadth in engineering training. At the graduate level, educators must accommodate students with diverse backgrounds and provide them with both a state-of-the-art understanding of the life sciences and the most advanced engineering skills. Engineering curricular content should include mechanics and materials, physical chemistry, transport phenomena, and control theory. Training from faculty with appointments and research programs in the life sciences is generally recommended, and additional life science content should also be integrated within the engineering curriculum. A capstone course in cellular engineering that includes opportunities for students to have hands-on experiences with state-of-the-art laboratory techniques is highly recommended. PMID:16450196

  15. Auxin and Cellular Elongation.

    PubMed

    Velasquez, Silvia Melina; Barbez, Elke; Kleine-Vehn, Jürgen; Estevez, José M

    2016-03-01

    Auxin is a crucial growth regulator in plants. However, a comprehensive understanding of how auxin induces cell expansion is perplexing, because auxin acts in a concentration- and cell type-dependent manner. Consequently, it is desirable to focus on certain cell types to exemplify the underlying growth mechanisms. On the other hand, plant tissues display supracellular growth (beyond the level of single cells); hence, other cell types might compromise the growth of a certain tissue. Tip-growing cells do not display neighbor-induced growth constraints and, therefore, are a valuable source of information for growth-controlling mechanisms. Here, we focus on auxin-induced cellular elongation in root hairs, exposing a mechanistic view of plant growth regulation. We highlight a complex interplay between auxin metabolism and transport, steering root hair development in response to internal and external triggers. Auxin signaling modules and downstream cascades of transcription factors define a developmental program that appears rate limiting for cellular growth. With this knowledge in mind, the root hair cell is a very suitable model system in which to dissect cellular effectors required for cellular expansion. PMID:26787325

  16. The New Cellular Immunology

    ERIC Educational Resources Information Center

    Claman, Henry N.

    1973-01-01

    Discusses the nature of the immune response and traces many of the discoveries that have led to the present state of knowledge in immunology. The new cellular immunology is directing its efforts toward improving health by proper manipulation of the immune mechanisms of the body. (JR)

  17. Histological, cellular and behavioral assessments of stroke outcomes after photothrombosis-induced ischemia in adult mice

    PubMed Central

    2014-01-01

    Background Following the onset of focal ischemic stroke, the brain experiences a series of alterations including infarct evolvement, cellular proliferation in the penumbra, and behavioral deficits. However, systematic study on the temporal and spatial dependence of these alterations has not been provided. Results Using multiple approaches, we assessed stroke outcomes by measuring brain injury, dynamic cellular and glial proliferation, and functional deficits at different times up to two weeks after photothrombosis (PT)-induced ischemic stroke in adult mice. Results from magnetic resonance imaging (MRI) and Nissl staining showed a maximal infarction, and brain edema and swelling 1–3 days after PT. The rate of Bromodeoxyuridine (Brdu)-labeled proliferating cell generation is spatiotemporal dependent in the penumbra, with the highest rate in post ischemic days 3–4, and higher rate of proliferation in the region immediate to the ischemic core than in the distant region. Similar time-dependent generation of proliferating GFAP+ astrocytes and Iba1+ microglia/macrophage were observed in the penumbra. Using behavioral tests, we showed that PT resulted in the largest functional deficits during post ischemic days 2–4. Conclusion Our study demonstrated that first a few days is a critical period that causes brain expansion, cellular proliferation and behavioral deficits in photothrombosis-induced ischemic model, and proliferating astrocytes only have a small contribution to the pools of proliferating cells and reactive astrocytes. PMID:24886391

  18. Roles of Nrf2 in cell proliferation and differentiation.

    PubMed

    Murakami, Shohei; Motohashi, Hozumi

    2015-11-01

    The Keap1-Nrf2 system plays pivotal roles in defense mechanisms by regulating cellular redox homeostasis. Nrf2 is an inducible transcription factor that activates a battery of genes encoding antioxidant proteins and phase II enzymes in response to oxidative stress and electrophilic xenobiotics. The activity of Nrf2 is regulated by Keap1, which promotes the ubiquitination and subsequent degradation of Nrf2 under normal conditions and releases the inhibited Nrf2 activity upon exposure to the stresses. Though an impressive contribution of the Keap1-Nrf2 system to the protection from exogenous and endogenous electrophilic insults has been well established, a line of evidence has suggested that the Keap1-Nrf2 system has various novel functions, particularly in cell proliferation and differentiation. Because the proliferation and differentiation of diverse cell types are often influenced and modulated by the cellular redox balance, Nrf2 has been considered to control these cellular processes by regulating the cellular levels of reactive oxygen species (ROS). In addition, analyses of the genome-wide distribution of Nrf2 have identified new sets of Nrf2 target genes whose products are involved in cell proliferation and differentiation but not necessarily in the regulation of oxidative stress. Considering the most characteristic features of Nrf2 as an inducible transcription factor, a newly emerged concept proposes that the Keap1-Nrf2 system translates environmental stresses into regulatory network signals in cell fate determination. In this review, we introduce the contribution of Nrf2 to lineage-specific differentiation, maintenance and differentiation of stem cells, and proliferation of normal and cancer cells, and we discuss how the response to fluctuating environments modulates cell behavior through the Keap1-Nrf2 system. PMID:26119783

  19. Immunohistochemical and ultrastructural characteristics of interstitial cells of Cajal in the rabbit duodenum. Presence of a single cilium

    PubMed Central

    Junquera, Concepción; Martínez-Ciriano, Carmen; Castiella, Tomás; Serrano, Pedro; Azanza, María Jesús; Ramón y Cajal Junquera, Santiago

    2007-01-01

    Abstract Santiago Ramón y Cajal discovered a new type of cell related to the myenteric plexus and also to the smooth muscle cells of the circular muscle layer of the intestine. Based on their morphology, relationships and staining characteristics, he considered these cells as primitive neurons. One century later, despite major improvements in cell biology, the interstitial cells of Cajal (ICCs) are still controversial for many researchers. The aim of study was to perform an immunohistochemical and ultrastructural characterization of the ICCs in the rabbit duo-denum. We have found interstitial cells that are positive for c-Kit, CD34 and nestin and are also positive for Ki67 protein, tightly associated with somatic cell proliferation. By means of electron microscopy, we describe ICCs around enteric ganglia. They present triangular or spindle forms and a very voluminous nucleus with scarce per-inuclear chromatin surrounded by a thin perinuclear cytoplasm that expands with long cytoplasmic processes. ICC processes penetrate among the smooth muscle cells and couple with the processes of other ICCs located in the connective tissue of the circular muscle layer and establish a three-dimensional network. Intercellular con-tacts by means of gap-like junctions are frequent. ICCs also establish gap-like junctions with smooth muscle cells. We also observe a population of interstitial cells of stellate morphology in the connective tissue that sur-rounds the muscle bundles in the circular muscle layer, usually close to nervous trunks. These cells establish different types of contacts with the muscle cells around them. In addition, the presence of a single cilium show-ing a structure 9 + 0 in an ICC is demonstrated for the first time. In conclusion, we report positive staining c-kit, CD34, nestin and Ki 67. ICCs fulfilled the usual transmission electron microscopy (TEM) criteria. A new ultrastructural characteristic of at least some ICCs is demonstrated: the presence of a single

  20. RNA Polymerase I Stability Couples Cellular Growth to Metal Availability

    PubMed Central

    Lee, Yueh-Jung; Lee, Chrissie Young; Grzechnik, Agnieszka; Gonzales-Zubiate, Fernando; Vashisht, Ajay A.; Lee, Albert; Wohlschlegel, James; Chanfreau, Guillaume

    2013-01-01

    Summary Zinc is an essential cofactor of all major eukaryotic RNA polymerases. How the activity of these enzymes is coordinated or regulated according to cellular zinc levels is largely unknown. Here we show that the stability of RNA Polymerase I (RNAPI) is tightly coupled to zinc availability in vivo. In zinc deficiency, RNAPI is specifically degraded by proteolysis in the vacuole in a pathway dependent on the exportin Xpo1p and deubiquitination of the RNAPI large subunit Rpa190p by Ubp2p and Ubp4p. RNAPII is unaffected, which allows for expression of genes required in zinc deficiency. RNAPI export to the vacuole is required for survival during zinc starvation, suggesting that degradation of zinc-binding subunits might provide a last resort zinc reservoir. These results reveal a hierarchy of cellular transcriptional activities during zinc starvation, and show that degradation of the most active cellular transcriptional machinery couples cellular growth and proliferation to zinc availability. PMID:23747013

  1. Nanogold Labeling of the Yeast Endosomal System for Ultrastructural Analyses

    PubMed Central

    Mari, Muriel; Griffith, Janice; Reggiori, Fulvio

    2014-01-01

    Endosomes are one of the major membrane sorting checkpoints in eukaryotic cells and they regulate recycling or destruction of proteins mostly from the plasma membrane and the Golgi. As a result the endosomal system plays a central role in maintaining cell homeostasis, and mutations in genes belonging to this network of organelles interconnected by vesicular transport, cause severe pathologies including cancer and neurobiological disorders. It is therefore of prime relevance to understand the mechanisms underlying the biogenesis and organization of the endosomal system. The yeast Saccharomyces cerevisiae has been pivotal in this task. To specifically label and analyze at the ultrastructural level the endosomal system of this model organism, we present here a detailed protocol for the positively charged nanogold uptake by spheroplasts followed by the visualization of these particles through a silver enhancement reaction. This method is also a valuable tool for the morphological examination of mutants with defects in endosomal trafficking. Moreover, it is not only applicable for ultrastructural examinations but it can also be combined with immunogold labelings for protein localization investigations. PMID:25046212

  2. Vanadium induced ultrastructural changes and apoptosis in male germ cells.

    PubMed

    Aragón, M A; Ayala, M E; Fortoul, T I; Bizarro, P; Altamirano-Lozano, M

    2005-01-01

    Vanadium is a transition metal that is emitted to the atmosphere during combustion of fossil fuels. In the environment, vanadium occurs in the (V) oxidized form, but in the body it is found exclusively in the (IV) oxidized form. Vanadium tetraoxide is an inorganic chemical species in the (IV) oxidized form that has been shown to induce toxic effects in vitro and in vivo. The reproductive toxicity of vanadium in males was studied through monitoring germ cell apoptosis during spermatogenesis. We analyzed ultrastructural damage, and testosterone and progesterone concentrations following vanadium tetraoxide administered to male mice for 60 days. Spermatogenesis stages I-III and X-XII frequently showed apoptotic germ cells in control and treated animals; vanadium tetraoxide treatment induced an increase in the number of germ cell apoptosis in stages I-III and XII at 9.4 and 18.8 mg/kg, respectively. Although spermatogenesis is regulated by testosterone, in our study this hormone level was not modified by vanadium administration; thus, germ cell death was not related with testosterone concentration. At the ultrastructural level, we observed inclusion structures that varied as to location and content in the Sertoli and germ cells. PMID:15808796

  3. Inter-relationships of haplosporidians deduced from ultrastructural studies.

    PubMed

    Hine, P M; Carnegie, R B; Burreson, E M; Engelsma, M Y

    2009-02-25

    We reviewed papers reporting haplosporidian ultrastructure to compare inter-relationships based on ultrastructure with those based on molecular data, to identify features that may be important in haplosporidian taxonomy, and to consider parasite taxonomy in relation to host taxonomy. There were links between the following: (1) the plasmodia of an abalone parasite, Haplosporidium nelsoni and Urosporidium crescens in the release of haplosporosomes; (2) H. costale and H. armoricanum in haplosporosome shape and presence and shape of Golgi in spores; (3) basal asporous crustacean haplosporidians which form haplosporosomes from formative bodies (FBs) in vegetative stages--H. nelsoni, which forms haplosporosomes from FBs in plasmodial cytoplasm, and H. louisiana, Minchinia spp. and Bonamia perspora, which form haplosporosomes from FBs in spores; (4) crustacean haplosporidians, Bonamia spp. and M. occulta in the predominance of uni- and binucleate stages; and (5) lipid-like vesicles in sporoplasms of H. costale, H. armoricanum, H. lusitanicum, H. pickfordi, H. montforti, and B. perspora. In general, these relationships reflect phylogenies based on molecular studies. As well as spore form and ornamentation, haplosporogenesis in spores appears to be taxonomically important. Parasite and host taxonomy were linked in the infection of lower invertebrates by Urosporidium spp., the infection of oysters by Bonamia spp., and of molluscs by Minchinia spp. Haplosporidium spp. are patently an artificial, paraphyletic group probably comprising many taxa. Consequently, the taxonomy of haplosporidians needs a thorough revision. PMID:19402456

  4. Ultrastructural comparison of Bonamia spp. (Haplosporidia) infecting ostreid oysters.

    PubMed

    Hine, P M; Carnegie, R B; Kroeck, M A; Villalba, A; Engelsma, M Y; Burreson, E M

    2014-07-24

    The ultrastructure of Bonamia from Ostrea angasi from Australia, Crassostrea ariakensis from the USA, O. puelchana from Argentina and O. edulis from Spain was compared with described Bonamia spp. All appear conspecific with B. exitiosa. The Bonamia sp. from Chile had similarities to the type B. exitiosa from New Zealand (NZ), but less so than the other forms recognized as B. exitiosa. Two groups of ultrastructural features were identified; those associated with metabolism (mitochondrial profiles, lipid droplets and endoplasmic reticulum), and those associated with haplosporogenesis (Golgi, indentations in the nuclear surface, the putative trans-Golgi network, perinuclear granular material and haplosporosome-like bodies). Metabolic features were regarded as having little taxonomic value, and as the process of haplosporogenesis is not understood, only haplosporosome shape and size may be of taxonomic value. However, the uni-nucleate stages of spore-forming haplosporidians are poorly known and may be confused with Bonamia spp. uni-nucleate stages. The many forms of NZ B. exitiosa have not been observed in other hosts, which may indicate that it has a plastic life cycle. Although there are similarities between NZ B. exitiosa and Chilean Bonamia in the development of a larger uni-nucleate stage and the occurrence of cylindrical confronting cisternae, the clarification of the identity of Chilean Bonamia must await molecular studies. PMID:25060497

  5. Collyricloides massanae (Digenea, Collyriclidae): spermatozoon ultrastructure and phylogenetic importance

    PubMed Central

    Bakhoum, Abdoulaye Jacque; Quilichini, Yann; Miquel, Jordi; Feliu, Carlos; Bâ, Cheikh Tidiane; Marchand, Bernard

    2014-01-01

    The spermatological characteristics of Collyricloides massanae (Digenea: Collyriclidae), a parasite of Apodemus sylvaticus caught in France, were studied by means of transmission electron microscopy. The mature sperm of C. massanae presents two axonemes of different lengths with the 9 + “1” pattern of the Trepaxonemata, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, one mitochondrion, a nucleus and granules of glycogen. An analysis of spermatological organisation emphasised some differences between the mature spermatozoon of C. massanae and those reported in the Gorgoderoidea species studied to date, specially belonging to the families Dicrocoeliidae, Paragonimidae and Troglotrematidae. The ultrastructural criteria described in C. massanae such as the morphology of both anterior and posterior spermatozoon extremities, the association “external ornamentation + cortical microtubules”, the type 2 of external ornamentation and the spine-like bodies would allow us to bring closer the Collyriclidae to Microphalloidea. However, further ultrastructural and molecular studies are needed particularly in the unexplored taxa in order to fully resolve the phylogenetic position of the Collyriclidae. PMID:25394323

  6. Ultrastructural study on the granulocytes of Uttara fowl (Gallus domesticus)

    PubMed Central

    Mohd, Khan Idrees; Mrigesh, Meena; Singh, Balwinder; Singh, Ishwar

    2016-01-01

    Aim: The present study was conducted to know the ultrastructural detail of the blood cells of Uttara fowl (native fowl of Uttarakhand). Materials and Methods: The experiment was conducted on 10 apparently healthy adult birds of either sex reared at the Instructional Poultry Farm, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. The blood was collected from wing vein using ethylenediamine tetraacetic acid as anticoagulant. The blood was further processed for scanning and transmission electron microscopic (TEM) studies separately. Results: Ultrastructurally, the heterophils were irregularly round in shape. The cytoplasm was laden with pleomorphic membrane-bound granules, viz., large elliptical-, medium oval-, large round-, and medium round-shaped granules. The eosinophils under TEM were irregularly circular in outline showing pseudopodia and finger-like cytoplasmic processes. The cytoplasmic granules were pleomorphic with elliptical-, round-, and rod-shaped granules. The basophils were irregularly circular in outline containing small hook-like cytoplasmic processes. The cytoplasm contained electron dense and electron lucent round-shaped granules. Conclusion: Granulocytes contained pleomorphic cytoplasmic granules. However, the shape and electron density of granules varied among the different granulocytes and helped in the characterization of different granulocytes. PMID:27057119

  7. Ultrastructural characteristics of human adult and infant cerebral cortical neurons.

    PubMed Central

    Ong, W Y; Garey, L J

    1991-01-01

    Biopsy specimens of human cerebral cortex from three adults and two infants were studied by correlating their light microscopic features in semithin sections with their ultrastructural characteristics. There was good tissue preservation, due to a minimum delay between obtaining the specimens and fixation. Pyramidal cells had a prominent apical dendrite, fine heterochromatin clumps in the nucleus and generally small numbers of cytoplasmic organelles, except for numerous free ribosomes in some of the large pyramids of Layers III to VI. Non-pyramidal cells lacked an apical dendrite and were further classified, on size and ultrastructure, into small, medium and large types. Large numbers of asymmetrical and symmetrical synapses were present in the neuropil but very few axosomatic synapses were found in the human cerebral cortex compared with subhuman primates and other mammals. Some symmetrical synapses were characterised by the presence of wide pre- and postsynaptic densities. The same general features of the adult cortex were also encountered in the infant, with certain exceptions. Many of the infant neurons had less densely packed heterochromatin, but greater numbers of free ribosomes, compared with the adult, and lipofuscin was absent. There was a total absence of myelinated fibres from the infant cortex; more large diameter dendrites were present than in the adult and axosomatic synapses were commoner. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 PMID:2050578

  8. [SPLEEN ORGAN-PRESERVING SURGERIES - ORGAN HISTO- ULTRASTRUCTURE].

    PubMed

    Amiranidze, M; Sumbadze, Ts; Sikharulidze, I; Gvidani, S; Markaryan, S

    2015-12-01

    The aim of our work is to study the functional activity of the spleen according to the histological and ultrastructural features of the organ as an indicator of the functional viability. Experiments performed using 36 white male rats (body mass 130-160 g.). 40-60% of the rat splenic tissue was removed by laparotomy under ether anesthesia. The rats were euthanized under general anesthesia after 1, 7, 15, 30, 90 and 180 days after surgery. Histological sections stained with hematoxylin and eosin. Ultrathin sections were studied by the electron microscope TESLA BS 500 with 4000 to 14000 magnification. It is shown that the significant changes in the spleen after organ - preserving surgery are the microcirculatiry disturbance in the first day of the experiment with the ewerblow cells to the bloodstream, a phenomenon of adhesion, which blocked blood circulation. The thickness of the capsule and the weight of the spleen do not reach the initiae values, but histo- and ultrastructural data suggest developins of defense function of the spleen and expediency of organ-preserving surgery. PMID:26719558

  9. Ultrastructural observation of oocytes in six types of stony corals.

    PubMed

    Tsai, Sujune; Chang, Wei-Chieh; Chavanich, Suchana; Viyakarn, Voranop; Lin, Chiahsin

    2016-08-01

    In this study, the ultrastructure of the oocytes of 6 types of scleractinian corals was observed by transmission electron microscopy (TEM). Moreover, histological and ultrastructural analyses were performed to improve our understanding of the organelles involved in coral oocyte formation. In all 6 stony coral species, the microvilli were tubular and directly grew from the surface of the oocyte membrane; yolk bodies, lipid granules, and cortical alveoli accounted for most of the volume inside the oocytes, suggesting that they are associated with energy storage and buoyancy. Clear differences were observed in the size of yolk bodies and lipid granules in the oocytes of the 6 stony coral species, which occupied approximately 55%-80% of the inner space of the oocytes. Galaxea fascicularis exhibited the largest lipid granule volume, but the oocytes contained only an average number of 12.45 lipid granules per unit area. Only Montipora incrassata oocytes contained symbiotic algae. The smallest size and proportion of lipid granules in M. incrassata oocytes may be attributed to the presence of symbiotic algae and large yolk bodies, which may help oocytes produce energy and function as a nutritional source. This study is crucial for improving the understanding of the basic biology of coral reproduction, and the ensuing datasets is critical for conservation-oriented studies seeking to cryopreserve corals during these times of dramatic global climate change. PMID:27265208

  10. Ultrastructural Changes of the Smooth Muscle in Esophageal Atresia.

    PubMed

    Al-Shraim, Mubarak M; Eid, Refaat A; Musalam, Adel Osman; Radad, Khaled; Ibrahim, Ashraf H M; Malki, Talal A

    2015-01-01

    Esophageal atresia (EA) with or without tracheo-esophageal fistula (TEF) is a relatively rare congenital anomaly. Despite the advances in the management techniques and neonatal intensive care, esophageal dysmotility remains a very common problem following EA/TEF repair. Our current study aimed to describe the most significant ultrastructural changes of the smooth muscle cells (SMCs) trying to highlight some of the underlying mechanisms of esophageal dysmotility following EA/TEF repair. Twenty-three biopsies were obtained from the tip of the lower esophageal pouch (LEP) of 23 patients during primary repair of EA/TEF. Light microscopic examination was performed with hematoxylin and eosin (HE), and Van Gieson's stains. Ultrastructural examination was done using transmission electron microscopy (TEM). Histopathological examination showed distortion of smooth muscle layer and deposition of an abundant amount of fibrous tissue in-between smooth muscles. Using TEM, SMCs exhibited loss of the cell-to-cell adhesion, mitochondrial vacuolation, formation of myelin figures, and apoptotic fragmentation. There were also plasmalemmal projections and formation of ghost bodies. Interestingly, SMCs were found extending pseudopodia-like projections around adjacent collagen fibers. Engulfed collagen fibers by SMCs underwent degradation within autophagic vacuoles. Degeneration of SMCs and deposition of abundant extracellular collagen fibers are prominent pathological changes in LEP of EA/TEF. These changes might contribute to the pathogenesis of esophageal dysmotility in patients who have survived EA/TEF. PMID:26548437

  11. Spermatozoon ultrastructure of Thysanotaenia congolensis (Cyclophyllidea, Anoplocephalidae, Inermicapsiferinae): phylogenetic implications.

    PubMed

    Miquel, Jordi; Świderski, Zdzisław; Feliu, Carlos

    2016-08-01

    The mature spermatozoon of Thysanotaenia congolensis, an intestinal parasite of black rat Rattus rattus from Cape Verde, is described by means of transmission electron microscopy. The ultrastructural organization of the sperm cell of T. congolensis follows Levron et al.'s type VII of the Eucestoda. It corresponds to a uniflagellate spermatozoon that presents crested bodies, periaxonemal sheath and intracytoplasmic walls, spiralled cortical microtubules and nucleus spiralled around the axoneme. These characteristics are also present in the spermatozoa of other inermicapsiferines and differ from the characters found in species belonging to the remaining subfamilies of anoplocephalids, namely Anoplocephalinae, Linstowiinae and Thysanosomatinae. Several authors consider the family Anoplocephalidae as a polyphyletic group, and its relationships with the Davaineidae are a matter of controversy. The phylogenetic implications of spermatological ultrastructural features present in inermicapsiferines and in the remaining anoplocephalids are discussed, and the available data on anoplocephalids are compared to similar results in davaineids in order to contribute to a better knowledge of relationships between these cyclophyllidean families. PMID:27083191

  12. Cyanobacterial ultrastructure in light of genomic sequence data.

    PubMed

    Gonzalez-Esquer, C R; Smarda, J; Rippka, R; Axen, S D; Guglielmi, G; Gugger, M; Kerfeld, C A

    2016-08-01

    Cyanobacteria are physiologically and morphologically diverse photosynthetic microbes that play major roles in the carbon and nitrogen cycles of the biosphere. Recently, they have gained attention as potential platforms for the production of biofuels and other renewable chemicals. Many cyanobacteria were characterized morphologically prior to the advent of genome sequencing. Here, we catalog cyanobacterial ultrastructure within the context of genomic sequence information, including high-magnification transmission electron micrographs that represent the diversity in cyanobacterial morphology. We place the image data in the context of tabulated protein domains-which are the structural, functional, and evolutionary units of proteins-from the 126 cyanobacterial genomes comprising the CyanoGEBA dataset. In particular, we identify the correspondence between ultrastructure and the occurrence of genes encoding protein domains related to the formation of cyanobacterial inclusions. This compilation of images and genome-level domain occurrence will prove useful for a variety of analyses of cyanobacterial sequence data and provides a guidebook to morphological features. PMID:27344651

  13. Ultrastructural changes in dysferlinopathy support defective membrane repair mechanism

    PubMed Central

    Cenacchi, G; Fanin, M; De Giorgi, L B; Angelini, C

    2005-01-01

    Background: The dysferlin gene has recently been shown to be involved in limb girdle muscular dystrophy type 2B and its allelic disease, Miyoshi myopathy, both of which are characterised by an active muscle degeneration and regeneration process. Dysferlin is known to play an essential role in skeletal muscle fibre repair, but the process underlying the pathogenetic mechanism of dysferlinopathy is not completely understood. Aims: To define both specific alterations of muscle fibres and a possible sequential mechanism of myopathy development. Methods: A histological, immunohistochemical, and ultrastructural analysis of 10 muscle biopsies from patients with molecularly diagnosed dysferlinopathy. Results: An inflammatory response was seen in most of the muscle biopsies. The immunohistochemical pattern demonstrated active regeneration and inflammation. Non-necrotic fibres showed alterations at different submicroscopic levels, namely: the sarcolemma and basal lamina, subsarcolemmal region, and sarcoplasmic compartment. In the subsarcolemmal region there were prominent aggregations of small vesicles, probably derived from the Golgi apparatus, which consisted of empty, swollen cisternae. In the sarcolemma there were many gaps and microvilli-like projections, whereas the basal lamina was multilayered. Conclusions: The histopathological, immunohistochemical, and ultrastructural data show that dysferlinopathy is characterised by a very active inflammatory/degenerative process, possibly associated with an inefficient repair and regenerative system. The presence of many crowded vesicles just beneath the sarcolemma provides submicroscopical proof of a defective resealing mechanism, which fails to repair the sarcolemma. PMID:15677541

  14. Human keratinocytes have two interconvertible modes of proliferation.

    PubMed

    Roshan, Amit; Murai, Kasumi; Fowler, Joanna; Simons, Benjamin D; Nikolaidou-Neokosmidou, Varvara; Jones, Philip H

    2016-02-01

    Single stem cells, including those in human epidermis, have a remarkable ability to reconstitute tissues in vitro, but the cellular mechanisms that enable this are ill-defined. Here we used live imaging to track the outcome of thousands of divisions in clonal cultures of primary human epidermal keratinocytes. Two modes of proliferation were seen. In 'balanced' mode, similar proportions of proliferating and differentiating cells were generated, achieving the 'population asymmetry' that sustains epidermal homeostasis in vivo. In 'expanding' mode, an excess of cycling cells was produced, generating large expanding colonies. Cells in expanding mode switched their behaviour to balanced mode once local confluence was attained. However, when a confluent area was wounded in a scratch assay, cells near the scratch switched back to expanding mode until the defect was closed. We conclude that the ability of a single epidermal stem cell to reconstitute an epithelium is explained by two interconvertible modes of proliferation regulated by confluence. PMID:26641719

  15. Building and re-building the heart by cardiomyocyte proliferation.

    PubMed

    Foglia, Matthew J; Poss, Kenneth D

    2016-03-01

    The adult human heart does not regenerate significant amounts of lost tissue after injury. Rather than making new, functional muscle, human hearts are prone to scarring and hypertrophy, which can often lead to fatal arrhythmias and heart failure. The most-cited basis of this ineffective cardiac regeneration in mammals is the low proliferative capacity of adult cardiomyocytes. However, mammalian cardiomyocytes can avidly proliferate during fetal and neonatal development, and both adult zebrafish and neonatal mice can regenerate cardiac muscle after injury, suggesting that latent regenerative potential exists. Dissecting the cellular and molecular mechanisms that promote cardiomyocyte proliferation throughout life, deciphering why proliferative capacity normally dissipates in adult mammals, and deriving means to boost this capacity are primary goals in cardiovascular research. Here, we review our current understanding of how cardiomyocyte proliferation is regulated during heart development and regeneration. PMID:26932668

  16. Cell proliferation inhibition in reduced gravity

    NASA Technical Reports Server (NTRS)

    Moos, P. J.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Extended durations of spaceflight have been shown to be deleterious on an organismic level; however, mechanisms underlying cellular sensitivity to the gravitational environment remain to be elucidated. The majority of the gravitational studies to date indicates that cell regulatory pathways may be influenced by their gravitational environment. Still, few cell biology experiments have been performed in space flight and even fewer experiments have been repeated on subsequent flights. With flight opportunities on STS-50, 54, and 57, Sf9 cells were flown in the BioServe Fluids Processing Apparatus and cell proliferation was measured with and without exposure to a cell regulatory sialoglycopeptide (CeReS) inhibitor. Results from these flights indicate that the Sf9 cells grew comparable to ground controls, that the CeReS inhibitor bound to its specific receptor, and that its signal transduction cascade was not gravity sensitive.

  17. Effect of weightlessness on lymphocyte proliferation

    NASA Technical Reports Server (NTRS)

    Cogoli, A.

    1981-01-01

    An experiment to study the effect of weightlessness on lymphocyte proliferation to detect possible alteration of the cells responsible for the immune response during long-duration space flights is described. Human lymphocytes in culture medium will be delivered shortly before launch in an incubator which will be kept at 37C. Mitogen will be added to the culture. A control without mitogen will be run in parallel. After 70 hours of incubation, radioactive thymidine will be added. After two hours, cellular activity will be stopped by fixation and incubator power switched off. Later, the amount of incorporated thymidine will be determined and the cell morphology and the distribution of cell organelles will be investigated.

  18. Fabrication of cellular materials

    NASA Astrophysics Data System (ADS)

    Prud'homme, Robert K.; Aksay, Ilhan A.; Garg, Rajeev

    1996-02-01

    Nature uses cellular materials in applications requiring strength while, simultaneously, minimizing raw materials requirements. Minimizing raw materials is efficient both in terms of the energy expended by the organism to synthesize the structure and in terms of the strength- to-weight ratio of the structure. Wood is the most obvious example of cellular bio-materials, and it is the focus of other presentations in this symposium. The lightweight bone structure of birds is another excellent example where weight is a key criterion. The anchoring foot of the common muscle [Mytilus edulis] whereby it attaches itself to objects is a further example of a biological system that uses a foam to fill space and yet conserve on raw materials. In the case of the muscle the foam is water filled and the foot structure distributes stress over a larger area so that the strength of the byssal thread from which it is suspended is matched to the strength of interfacial attachment of the foot to a substrate. In these examples the synthesis and fabrication of the cellular material is directed by intercellular, genetically coded, biochemical reactions. The resulting cell sizes are microns in scale. Cellular materials at the next larger scale are created by organisms at the next higher level of integration. For example an African tree frog lays her eggs in a gas/fluid foam sack she builds on a branch overhanging a pond. The outside of the foam sack hardens in the sun and prevents water evaporation. The foam structure minimizes the amount of fluid that needs to be incorporated into the sack and minimizes its weight. However, as far as the developing eggs are concerned, they are in an aqueous medium, i.e. the continuous fluid phase of the foam. After precisely six days the eggs hatch, and the solidified outer wall re-liquefies and dumps the emerging tadpoles into the pond below. The bee honeycomb is an example of a cellular material with exquisite periodicity at millimeter length scales. The

  19. Dehydroepiandrosterone and metformin regulate proliferation of murine T lymphocytes

    PubMed Central

    Solano, M E; Sander, V; Wald, M R; Motta, A B

    2008-01-01

    The aim of the present study was to assess the effect of dehydroepiandrosterone (DHEA: 10 µM) and metformin (10 µM and 100 µM) in regulating proliferation of cultured T lymphocytes. T cells were isolated from lymph nodes of prepuberal BALB/c mice. We found that DHEA, metformin and DHEA + metformin added to the incubation media diminished proliferation of T cells. The inhibition by DHEA was higher than that produced by metformin, while the combined treatment showed a synergistic action that allowed us to speculate distinct regulatory pathways. This was supported later by other findings in which the addition of DHEA to the incubation media did not modify T lymphocyte viability, while treatment with metformin and DHEA + metformin diminished cellular viability and increased both early and late apoptosis. Moreover, DHEA diminished the content of the anti-oxidant molecule glutathione (GSH), whereas M and DHEA + metformin increased GSH levels and diminished lipid peroxidation. We conclude that DHEA and metformin diminish proliferation of T cells through different pathways and that not only the increase, but also the decrease of oxidative stress inhibited proliferation of T cells, i.e. a minimal status of oxidative stress, is necessary to trigger cellular response. PMID:18549441

  20. Cellularized Bilayer Pullulan-Gelatin Hydrogel for Skin Regeneration.

    PubMed

    Nicholas, Mathew N; Jeschke, Marc G; Amini-Nik, Saeid

    2016-05-01

    Skin substitutes significantly reduce the morbidity and mortality of patients with burn injuries and chronic wounds. However, current skin substitutes have disadvantages related to high costs and inadequate skin regeneration due to highly inflammatory wounds. Thus, new skin substitutes are needed. By combining two polymers, pullulan, an inexpensive polysaccharide with antioxidant properties, and gelatin, a derivative of collagen with high water absorbency, we created a novel inexpensive hydrogel-named PG-1 for "pullulan-gelatin first generation hydrogel"-suitable for skin substitutes. After incorporating human fibroblasts and keratinocytes onto PG-1 using centrifugation over 5 days, we created a cellularized bilayer skin substitute. Cellularized PG-1 was compared to acellular PG-1 and no hydrogel (control) in vivo in a mouse excisional skin biopsy model using newly developed dome inserts to house the skin substitutes and prevent mouse skin contraction during wound healing. PG-1 had an average pore size of 61.69 μm with an ideal elastic modulus, swelling behavior, and biodegradability for use as a hydrogel for skin substitutes. Excellent skin cell viability, proliferation, differentiation, and morphology were visualized through live/dead assays, 5-bromo-2'-deoxyuridine proliferation assays, and confocal microscopy. Trichrome and immunohistochemical staining of excisional wounds treated with the cellularized skin substitute revealed thicker newly formed skin with a higher proportion of actively proliferating cells and incorporation of human cells compared to acellular PG-1 or control. Excisional wounds treated with acellular or cellularized hydrogels showed significantly less macrophage infiltration and increased angiogenesis 14 days post skin biopsy compared to control. These results show that PG-1 has ideal mechanical characteristics and allows ideal cellular characteristics. In vivo evidence suggests that cellularized PG-1 promotes skin regeneration and may

  1. Differential regulation of cell proliferation in neurogenic zones in mice lacking cystine transport by xCT

    SciTech Connect

    Liu, Richard R.; Brown, Craig E.; Murphy, Timothy H.

    2007-12-21

    The cystine/glutamate exchanger (xCT) supplies intracellular cyst(e)ine for the production of glutathione, a major cellular anti-oxidant. xCT is enriched in brain regions associated with neurogenesis. Previous studies have shown that the malfunction of this protein greatly attenuates cell proliferation in vitro and is associated with brain atrophy in vivo. Using mice that are homozygous for a function-blocking deletion in xCT (Sut mice), we examined in vivo the role of xCT in cell proliferation in neurogenic regions of the subventricular zone (SVZ) and denate gyrus (DG) in the adult brain. Our results indicate that a high level of cellular proliferation in the adult brain persists even in the absence of functional xCT. Furthermore, in both young adult and middle-aged mice (3 and 11 months old), rates of SVZ cell proliferation were comparable between Sut and wild-type controls, although there was trend towards reduced proliferation in Sut mice (12% and 9% reduction, respectively). To our surprise, rates of cell proliferation in the DG were elevated in both 3- and 11-month-old Sut mice relative to controls (22% and 28% increase, respectively). These results demonstrate that xCT expression plays a role in regulating cellular proliferation in the DG, but not the SVZ of adult mice. Furthermore, unlike previous in vitro studies, our in vivo observations clearly indicate that xCT is not essential for ongoing cellular proliferation.

  2. Hypergravity Stimulates Osteoblast Proliferation Via Matrix-Integrin-Signaling Pathways

    NASA Technical Reports Server (NTRS)

    Vercoutere, W.; Parra, M.; Roden, C.; DaCosta, M.; Wing, A.; Damsky, C.; Holton, E.; Searby, N.; Globus, R.; Almeida, E.

    2003-01-01

    Extensive characterizations of the physiologic consequences of microgravity and gravity indicate that lack of weight-bearing may cause tissue atrophy through cellular and subcellular level mechanisms. We hypothesize that gravity is needed for the efficient transduction of cell growth and survival signals from the extra-cellular matrix (ECM) in mechanosensitive tissues. Recent work from our laboratory and from others shows that an increase of gravity increases bone cell growth and survival. We found that 50-g hypergravity stimulation increased osteoblast proliferation for cells grown on Collagen Type I and Fibronectin, but not on Laminin or uncoated plastic. This may be a tissue-specific response, because 50-g hypergravity stimulation caused no increase in proliferation for primary rat fibroblasts. These results combined with RT-PCR for all possible integrins indicate that beta1 integrin subunit may be involved. The osteoblast proliferation response on Collagen Type I was greater at 25-g than at 10-g or 50-g; 24-h duration of hypergravity was necessary to see an increase in proliferation. Survival was enhanced during hypergravity stimulation by the presence of matrix. Flow cytometry analysis indicated that cell cycle may be altered; BrdU incorporation in proliferating cells showed an increase in the number of actively dividing cells from about 60% at 1-g to over 90% at 25-g. To further investigate the molecular components involved, we applied fluorescence labeling of cytoskeletal and signaling molecules to cells after 2 to 30 minutes of hypergravity stimulation. While structural components did not appear to be altered, phosphorylation increased, indicating that signaling pathways may be activated. These data indicate that gravity mechanostimulation of osteoblast proliferation involves specific matrix-integrin signaling pathways which are sensitive to duration and g-level.

  3. Identification of Predictive Gene Markers for Multipotent Stromal Cell Proliferation.

    PubMed

    Bellayr, Ian H; Marklein, Ross A; Lo Surdo, Jessica L; Bauer, Steven R; Puri, Raj K

    2016-06-01

    Multipotent stromal cells (MSCs) are known for their distinctive ability to differentiate into different cell lineages, such as adipocytes, chondrocytes, and osteocytes. They can be isolated from numerous tissue sources, including bone marrow, adipose tissue, skeletal muscle, and others. Because of their differentiation potential and secretion of growth factors, MSCs are believed to have an inherent quality of regeneration and immune suppression. Cellular expansion is necessary to obtain sufficient numbers for use; however, MSCs exhibit a reduced capacity for proliferation and differentiation after several rounds of passaging. In this study, gene markers of MSC proliferation were identified and evaluated for their ability to predict proliferative quality. Microarray data of human bone marrow-derived MSCs were correlated with two proliferation assays. A collection of 24 genes were observed to significantly correlate with both proliferation assays (|r| >0.70) for eight MSC lines at multiple passages. These 24 identified genes were then confirmed using an additional set of MSCs from eight new donors using reverse transcription quantitative polymerase chain reaction (RT-qPCR). The proliferative potential of the second set of MSCs was measured for each donor/passage for confluency fraction, fraction of EdU+ cells, and population doubling time. The second set of MSCs exhibited a greater proliferative potential at passage 4 in comparison to passage 8, which was distinguishable by 15 genes; however, only seven of the genes (BIRC5, CCNA2, CDC20, CDK1, PBK, PLK1, and SPC25) demonstrated significant correlation with MSC proliferation regardless of passage. Our analyses revealed that correlation between gene expression and proliferation was consistently reduced with the inclusion of non-MSC cell lines; therefore, this set of seven genes may be more strongly associated with MSC proliferative quality. Our results pave the way to determine the quality of an MSC population for a

  4. Ultrastructural features of endometrial-myometrial interface and its alteration in adenomyosis.

    PubMed

    Zhang, Ying; Zhou, Li; Li, Tin C; Duan, Hua; Yu, Pei; Wang, Hong Y

    2014-01-01

    The endometrial-myometrial interface (EMI) is a specific functional region of uterus. However, our knowledge on EMI ultrastructure both in normal uterus and adenomyosis is far from enough to understand its pathology. In this study, used the samples of EMI and outer myometrium (OM) from the adenomyosis hysterectomy specimens and the subjects from the control uteri, we prospectively compared the ultrastructure of myocytes from EMI and OM, the ultrastructural changes of EMI between the proliferative and secretory phases, and the ultrastructural difference of EMI between adenomyosis and the control group. In both adenomyosis and control group, there were differences in ultrastructure between myocytes from EMI and OM. Specifically, the myocytes from EMI were rich in organelles. In contrast, the myocytes from OM had abundant contractile structural components. In the proliferative phase, the myocytes from EMI in adenomyosis had significantly smaller cell and nucleus diameter than those from the control group, but in the secretory phase, the difference was not significant. In the control group, the various ultrastructural features of myocytes from EMI including the mean diameter of cell and nuclei and the myofilaments/cytoplasm ratio exhibited cyclical changes, but in adenomyosis, the normal cyclical changes were absent. In conclusions, there are significant ultrastructural differences between the myocytes from EMI and OM. The myocytes in women with adenomyosis were significantly different to the control subjects, primarily because the normal cyclical changes were absent. PMID:24817942

  5. Ultrastructural features of endometrial-myometrial interface and its alteration in adenomyosis

    PubMed Central

    Zhang, Ying; Zhou, Li; Li, Tin C; Duan, Hua; Yu, Pei; Wang, Hong Y

    2014-01-01

    The endometrial-myometrial interface (EMI) is a specific functional region of uterus. However, our knowledge on EMI ultrastructure both in normal uterus and adenomyosis is far from enough to understand its pathology. In this study, used the samples of EMI and outer myometrium (OM) from the adenomyosis hysterectomy specimens and the subjects from the control uteri, we prospectively compared the ultrastructure of myocytes from EMI and OM, the ultrastructural changes of EMI between the proliferative and secretory phases, and the ultrastructural difference of EMI between adenomyosis and the control group. In both adenomyosis and control group, there were differences in ultrastructure between myocytes from EMI and OM. Specifically, the myocytes from EMI were rich in organelles. In contrast, the myocytes from OM had abundant contractile structural components. In the proliferative phase, the myocytes from EMI in adenomyosis had significantly smaller cell and nucleus diameter than those from the control group, but in the secretory phase, the difference was not significant. In the control group, the various ultrastructural features of myocytes from EMI including the mean diameter of cell and nuclei and the myofilaments/cytoplasm ratio exhibited cyclical changes, but in adenomyosis, the normal cyclical changes were absent. In conclusions, there are significant ultrastructural differences between the myocytes from EMI and OM. The myocytes in women with adenomyosis were significantly different to the control subjects, primarily because the normal cyclical changes were absent. PMID:24817942

  6. Finite element modeling of hyper-viscoelasticity of peripheral nerve ultrastructures.

    PubMed

    Chang, Cheng-Tao; Chen, Yu-Hsing; Lin, Chou-Ching K; Ju, Ming-Shaung

    2015-07-16

    The mechanical characteristics of ultrastructures of rat sciatic nerves were investigated through animal experiments and finite element analyses. A custom-designed dynamic testing apparatus was used to conduct in vitro transverse compression experiments on the nerves. The optical coherence tomography (OCT) was utilized to record the cross-sectional images of nerve during the dynamic testing. Two-dimensional finite element models of the nerves were built based on their OCT images. A hyper-viscoelastic model was employed to describe the elastic and stress relaxation response of each ultrastructure of the nerve, namely the endoneurium, the perineurium and the epineurium. The first-order Ogden model was employed to describe the elasticity of each ultrastructure and a generalized Maxwell model for the relaxation. The inverse finite element analysis was used to estimate the material parameters of the ultrastructures. The results show the instantaneous shear modulus of the ultrastructures in decreasing order is perineurium, endoneurium, and epineurium. The FE model combined with the first-order Ogden model and the second-order Prony series is good enough for describing the compress-and-hold response of the nerve ultrastructures. The integration of OCT and the nonlinear finite element modeling may be applicable to study the viscoelasticity of peripheral nerve down to the ultrastructural level. PMID:25912662

  7. Cellular growth in biofilms

    SciTech Connect

    Wood, B.D.; Whitaker, S.

    1999-09-20

    In this paper the authors develop a macroscopic evolutionary equation for the growth of the cellular phase starting from a microscopic description of mass transport and a simple structured model for product formation. The methods of continuum mechanics and volume averaging are used to develop the macroscopic representation by carefully considering the fluxes of chemical species that pertain to cell growth. The concept of structured models is extended to include the transport of reacting chemical species at the microscopic scale. The resulting macroscopic growth model is similar in form to previously published models for the transport of a single substrate and electron donor and for the production of cellular mass and exopolymer. The method of volume averaging indicated under what conditions the developed growth model is valid and provides an explicit connection between the relevant microscopic model parameters and their corresponding macroscopic counterparts.

  8. Immunohistochemical and ultrastructural evidence of functional organization along the Corydoras paleatus intestine.

    PubMed

    Plaul, Silvia E; Pastor, Raquel; Díaz, Alcira O; Barbeito, Claudio G

    2016-03-01

    The Neotropical catfish, Corydoras paleatus (Callichthyidae) is a facultative air-breathing teleost that makes use of the caudal portion of the intestine as an accessory air-breathing organ. This portion is highly modified, being well vascularized with capillaries between epithelial cells, which makes it well suited for gas exchange. Instead, the cranial portion is a digestion and absorption site, as it has a typical intestinal epithelium with columnar cells arranged in a single row, villi and less vascularized tunica mucosa. Therefore, the intestine was studied by light and electron microscopy to assess differences between the cranial, middle and caudal portions. To characterize the potential for cell proliferation of this organ, we used anti-proliferating cell nuclear antigen antibody and anti-Na(+) K(+) -ATPase monoclonal antibody to detect the presence of Na(+) /K(+) pump. In C. paleatus it was observed that cell dynamics showed a decreasing gradient of proliferation in cranio-caudal direction. Also, the intestine of this catfish is an important organ in ionoregulation: the basolateral Na(+) /K(+) pump may have an active role, transporting Na(+) out of the cell while helping to maintain the repose potential and to regulate cellular volume. PMID:26910640

  9. Initial lesions of HIV-related Kaposi's sarcoma--a histological, immunohistochemical, and ultrastructural study.

    PubMed

    Schulze, H J; Rütten, A; Mahrle, G; Steigleder, G K

    1987-01-01

    Kaposi's sarcoma (KS) in human immunodeficiency virus infection (HIV) has become a rather frequent manifestation of the previously rare disease with fatal outcome. Initial lesions of KS were studied by means of histopathology, immunohistology, and electron microscopy in order to define the earliest alterations. The histopathological changes of initial lesions were distinct, consisting of (1) discrete proliferation of capillary vessels, (2) dissection of collagen by proliferating spindle cells which formed slits, (3) atypical spindle cells arranged in an Indian file pattern, and (4) the lack of any inflammatory cellular infiltrate. Double staining with antibodies against vimentin and immunohistochemical markers for endothelial cells revealed that slits forming vimentin-positive spindle cells displayed laminin, factor VIII, and PAL-E. Atypical vimentin-positive spindle cells arranged in an Indian file pattern inconsistently expressed laminin and factor VIII, but not PAL-E. KS cells rarely stained with the lectin UEA I, not even in case of less advanced dedifferentiation. Electron microscopy showed gradual transformation between spindle cells forming slits and those having lost the ability to form incomplete vessel walls. The present findings support the view that KS develops from the endothelial cells of the blood vessels. The proliferation of atypical endothelial cells as early as in initial lesions and the lack of inflammation favors the primary neoplastic genesis of KS. PMID:3324975

  10. Cellular dysfunction in sepsis.

    PubMed

    Singer, Mervyn

    2008-12-01

    Cellular dysfunction is a commonplace sequelum of sepsis and other systemic inflammatory conditions. Impaired energy production (related to mitochondrial inhibition, damage, and reduced protein turnover) appears to be a core mechanism underlying the development of organ dysfunction. The reduction in energy availability appears to trigger a metabolic shutdown that impairs normal functioning of the cell. This may well represent an adaptive mechanism analogous to hibernation that prevents a massive degree of cell death and thus enables eventual recovery in survivors. PMID:18954700

  11. Radiolabeled cellular blood elements

    SciTech Connect

    Thakur, M.L.; Ezikowitz, M.D.; Hardeman, M.R.

    1985-01-01

    This book contains papers delivered by guest lectures and participants at the Advanced Study Institute's colloquium on Radiolabeled Cellular Blood Elements at Maratea, Italy on August 29, to September 9, 1982. The book includes chapters on basic cell physiology and critical reviews of data and experience in the preparation and use of radiolabeled cells, as well as reports on very recent developments, from a faculty that included experts on cell physiology in health and disease and on the technology of in vivo labeling.

  12. Global proliferation of cephalopods.

    PubMed

    Doubleday, Zoë A; Prowse, Thomas A A; Arkhipkin, Alexander; Pierce, Graham J; Semmens, Jayson; Steer, Michael; Leporati, Stephen C; Lourenço, Sílvia; Quetglas, Antoni; Sauer, Warwick; Gillanders, Bronwyn M

    2016-05-23

    Human activities have substantially changed the world's oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2-4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries-independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment. PMID:27218844

  13. Predictability in cellular automata.

    PubMed

    Agapie, Alexandru; Andreica, Anca; Chira, Camelia; Giuclea, Marius

    2014-01-01

    Modelled as finite homogeneous Markov chains, probabilistic cellular automata with local transition probabilities in (0, 1) always posses a stationary distribution. This result alone is not very helpful when it comes to predicting the final configuration; one needs also a formula connecting the probabilities in the stationary distribution to some intrinsic feature of the lattice configuration. Previous results on the asynchronous cellular automata have showed that such feature really exists. It is the number of zero-one borders within the automaton's binary configuration. An exponential formula in the number of zero-one borders has been proved for the 1-D, 2-D and 3-D asynchronous automata with neighborhood three, five and seven, respectively. We perform computer experiments on a synchronous cellular automaton to check whether the empirical distribution obeys also that theoretical formula. The numerical results indicate a perfect fit for neighbourhood three and five, which opens the way for a rigorous proof of the formula in this new, synchronous case. PMID:25271778

  14. Probabilistic cellular automata.

    PubMed

    Agapie, Alexandru; Andreica, Anca; Giuclea, Marius

    2014-09-01

    Cellular automata are binary lattices used for modeling complex dynamical systems. The automaton evolves iteratively from one configuration to another, using some local transition rule based on the number of ones in the neighborhood of each cell. With respect to the number of cells allowed to change per iteration, we speak of either synchronous or asynchronous automata. If randomness is involved to some degree in the transition rule, we speak of probabilistic automata, otherwise they are called deterministic. With either type of cellular automaton we are dealing with, the main theoretical challenge stays the same: starting from an arbitrary initial configuration, predict (with highest accuracy) the end configuration. If the automaton is deterministic, the outcome simplifies to one of two configurations, all zeros or all ones. If the automaton is probabilistic, the whole process is modeled by a finite homogeneous Markov chain, and the outcome is the corresponding stationary distribution. Based on our previous results for the asynchronous case-connecting the probability of a configuration in the stationary distribution to its number of zero-one borders-the article offers both numerical and theoretical insight into the long-term behavior of synchronous cellular automata. PMID:24999557

  15. Quantum cellular automata

    NASA Astrophysics Data System (ADS)

    Porod, Wolfgang; Lent, Craig S.; Bernstein, Gary H.

    1994-06-01

    The Notre Dame group has developed a new paradigm for ultra-dense and ultra-fast information processing in nanoelectronic systems. These Quantum Cellular Automata (QCA's) are the first concrete proposal for a technology based on arrays of coupled quantum dots. The basic building block of these cellular arrays is the Notre Dame Logic Cell, as it has been called in the literature. The phenomenon of Coulomb exclusion, which is a synergistic interplay of quantum confinement and Coulomb interaction, leads to a bistable behavior of each cell which makes possible their use in large-scale cellular arrays. The physical interaction between neighboring cells has been exploited to implement logic functions. New functionality may be achieved in this fashion, and the Notre Dame group invented a versatile majority logic gate. In a series of papers, the feasibility of QCA wires, wire crossing, inverters, and Boolean logic gates was demonstrated. A major finding is that all logic functions may be integrated in a hierarchial fashion which allows the design of complicated QCA structures. The most complicated system which was simulated to date is a one-bit full adder consisting of some 200 cells. In addition to exploring these new concepts, efforts are under way to physically realize such structures both in semiconductor and metal systems. Extensive modeling work of semiconductor quantum dot structures has helped identify optimum design parameters for QCA experimental implementations.

  16. Piezo Proteins: Regulators of Mechanosensation and Other Cellular Processes*

    PubMed Central

    Bagriantsev, Sviatoslav N.; Gracheva, Elena O.; Gallagher, Patrick G.

    2014-01-01

    Piezo proteins have recently been identified as ion channels mediating mechanosensory transduction in mammalian cells. Characterization of these channels has yielded important insights into mechanisms of somatosensation, as well as other mechano-associated biologic processes such as sensing of shear stress, particularly in the vasculature, and regulation of urine flow and bladder distention. Other roles for Piezo proteins have emerged, some unexpected, including participation in cellular development, volume regulation, cellular migration, proliferation, and elongation. Mutations in human Piezo proteins have been associated with a variety of disorders including hereditary xerocytosis and several syndromes with muscular contracture as a prominent feature. PMID:25305018

  17. Antioxidant activity and ultrastructural changes in gastric cancer cell lines induced by Northeastern Thai edible folk plant extracts

    PubMed Central

    2013-01-01

    cytotoxicity in vitro on cancer cells but not on normal cell lines as resolved in tissue culture and ultrastructural analysis. This is the first report to show the effect on cellular alteration as apoptosis of an ethyl acetate extract of S. gratum and J. gangetica. Further studies are now focused on individual isolates and their function, prioritizing on S. gratum and J. gangetica for the development of novel therapeutics and combatants against cancer. PMID:23497063

  18. Ultrastructural analysis of the integument of a desert-adapted mammal, the one-humped camel (Camelus dromedarius).

    PubMed

    Pfeiffer, C J; Osman, A H K; Pfeiffer, D C

    2006-04-01

    In this study, we conducted a light microscopic and ultrastructural analysis of the integument of the one-humped camel (Camelus dromedarius). In general, the epidermal strata of the camel integument appeared typical of those found in non-desert mammals. Two cell populations were noted in the stratum basale: one with a flat, non-serrated base and the other with a highly serrated base. Typical fine structure was observed in keratinocytes of the stratum spinosum and stratum granulosum. The stratum corneum was six to 10 cells thick. Within the different strata, overall cell morphologies and the general distribution and relative abundance of cellular organelles appeared typical. Dermal features included the presence of myoepithelial cells surrounding apocrine tubular glands. Inter- or intracellular canaliculi within the secretory cells of the apocrine glands, reported to be present in certain other non-desert mammals, were not evident in the camel. Together, these data indicate that while the camel is clearly adapted for a desert lifestyle, these adaptations do not include significant specializations at the cellular or subcellular level in the integument. PMID:16542174

  19. Intraretinal proliferation induced by retinal detachment

    SciTech Connect

    Fisher, S.K.; Erickson, P.A.; Lewis, G.P.; Anderson, D.H. )

    1991-05-01

    Cellular proliferation after retinal detachment was studied by {sup 3}H-thymidine light microscopic autoradiography in cats that had experimental detachments of 0.5-180 days duration. The animals underwent labeling 2 hr before death with an intraocular injection of 200 microCi of {sup 3}H-thymidine. The number of labeled nuclei were counted in 1-micron thick tissue sections in regions of detachment, in regions of the experimental eyes that remained attached, and in control eyes that had no detachments. In the normal eye, in one that had only the lens and vitreous removed, and in the eyes with 0.5- and 1-day detachments, the number of labeled nuclei ranged from 0/mm (0.5-day detachment) to 0.38/mm (lens and vitreous removed only). By 2 days postdetachment, the number of labeled nuclei increased to 2.09/mm. The highest levels of labeling occurred in two animals with detachments of 3 (7.86/mm) and 4 (7.09/mm) days. Thereafter, the numbers declined steadily until near-baseline counts were obtained at 14 days. The number of labeled nuclei was slightly elevated in the attached regions of two animals with 3-day detachments. Labeled cell types included: Mueller cells, astrocytes, pericytes, and endothelial cells of the retinal vasculature, and both resident (microglial cells) and invading macrophages. In an earlier study RPE cells were also shown to proliferate in response to detachment. Thus, these data show that proliferation is a rapid response to detachment, reaching a maximum within 4 days, and that virtually every nonneuronal cell type in the retina can participate in this response. The data suggest that events leading to such clinical manifestations as proliferative vitreoretinopathy and subretinal fibrosis may have their beginnings in this very early proliferative response.

  20. CELLULAR PATHOLOGY OF A GRANULOSIS VIRUS INFECTION

    EPA Science Inventory

    Nuclear and cytoplasmic ultrastructural changes were examined in Spodoptera frugiperda (SF) larval fat body cells infected with granulosis virus (GV). Soon after infection necleocapsidlike structures were observed within the nucleus associated with nuclear pores. The earliest cel...

  1. Ultrastructural features of collagen in thyroid carcinoma tissue observed by polarization second harmonic generation microscopy

    PubMed Central

    Tokarz, Danielle; Cisek, Richard; Golaraei, Ahmad; Asa, Sylvia L.; Barzda, Virginijus; Wilson, Brian C.

    2015-01-01

    Changes in collagen ultrastructure between malignant and normal human thyroid tissue were investigated ex vivo using polarization second harmonic generation (SHG) microscopy. The second-order nonlinear optical susceptibility tensor component ratio and the degree of linear polarization (DOLP) of the SHG signal were measured. The ratio values are related to the collagen ultrastructure, while DOLP indicates the relative amount of coherent signal and incoherent scattering of SHG. Increase in ratio values and decrease in DOLP were observed for tumor tissue compared to normal thyroid, indicating higher ultrastructural disorder in tumor collagen. PMID:26417516

  2. How effectively does a clinostat mimic the ultrastructural effects of microgravity on plant cells?

    NASA Technical Reports Server (NTRS)

    Moore, R.

    1990-01-01

    Columella cells of seedlings of Zea mays L. cv. Bear Hybrid grown in the microgravity of orbital flight allocate significantly larger relative-volumes to hyaloplasm and lipid bodies, and significantly smaller relative-volumes to dictyosomes, plastids, and starch than do columella cells of seedlings grown at 1 g. The ultrastructure of columella cells of seedlings grown at 1 g and on a rotating clinostat is not significantly different. However, the ultrastructure of cells exposed to these treatments differs significantly from that of seedlings grown in microgravity. These results indicate that the actions of a rotating clinostat do not mimic the ultrastructural effects of microgravity in columella cells of Z. mays.

  3. II. Capsular vaso-mimicry formed by transgenic mammary tumor spheroids implanted ectopically into mouse dorsal skin fold: implications for cellular mechanisms of metastasis

    PubMed Central

    Witkiewicz, Halina

    2013-01-01

    Most cancer patients die of metastatic disease, not primary tumors, while biological mechanisms leading to metastases remain unclear and effective therapies are missing. Using a mouse dorsal skin chamber model we had observed that tumor growth and vasculature formation could be influenced by the way in vitro cultured (avascular) spheroids of N202 breast tumor cells were implanted; co-implantation of lactating breast tissue created stimulating microenvironment, whereas the absence of the graft resulted in temporary tumor dormancy. This report addressed the issue of cellular mechanisms of the vasculogenic switch that ended the dormancy. In situ ultrastructural analysis revealed that the tumors survived in ectopic microenvironment until some of host and tumor stem cells evolved independently into cells initiating the vasculogenic switch. The tumor cells that survived and proliferated under hypoxic conditions for three weeks were supported by erythrogenic autophagy of others. However, the host microenvironment first responded as it would to non-immunogenic foreign bodies, i.e., by encapsulating the tumor spheroids with collagen-producing fibroblasts. That led to a form of vaso-mimicry consisting of tumor cells amid tumor-derived erythrosomes (synonym of erythrocytes), megakaryocytes and platelets, and encapsulating them all, the host fibroblasts. Such capsular vaso-mimicry could potentially facilitate metastasis by fusing with morphologically similar lymphatic vessels or veins. Once incorporated into the host circulatory system, tumor cells could be carried away passively by blood flow, regardless of their genetic heterogeneity. The fake vascular segment would have permeability properties different from genuine vascular endothelium. The capsular vaso-mimicry was different from vasculogenic mimicry earlier observed in metastases-associated malignant tumors where channels formed by tumor cells were said to contain circulating blood. Structures similar to the vasculogenic

  4. Ultrastructural and Metabolic Determinants of Resistance to Azo-dye and Susceptibility to Nitrosamine Carcinogenesis of the Guinea-pig

    PubMed Central

    Bryant, G. M.; Sohal, R. S.; Argus, M. F.; Arcos, J. C.

    1977-01-01

    During diethylnitrosamine (DEN) administration, a distinctive difference was observed between rats and guinea-pigs in the sequence of ultrastructural changes in the hepatic endoplasmic reticulum (ER). In DEN-induced hepatic tumour cells in the guinea-pig there was extensive proliferation of the rough ER, while the smooth ER was quite sparse; in the premalignant liver the opposite was noted. This is in contrast to the rat, in which administration of either DEN or 3′-methyl-4-dimethylaminoazobenzene (3′-Me-DAB) brings about, in both premalignant and malignant hepatic tissue, proliferation of the smooth ER and sparsity of the rough ER. Yet, as in the rat, the number of ribosomes on the outer surface of the guinea-pig liver rough ER is greatly reduced and this is paralleled by a 49% decrease of the RNA/protein ratio as early as 4 weeks of nitrosamine administration. The decrease of RNA/protein ratio and ultrastructurally observed loss of ribosomes from the ER, following nitrosamine administration, correlate with a decrease of photometric response of microsomal suspensions to the sulphydryl probe, p-chloromercuribenzoate. While azo-dye-reductase activity is higher in untreated rats than in untreated guinea-pigs, feeding 3′-Me-DAB for 6 weeks brings about a 76% decrease in the rat, but no significant decrease in the guinea-pig, which is refractory to azo-dye carcinogenesis. Thus, the ability of the liver to inactivate the dye is greatly decreased in the rat, but not in the guinea-pig, as administration progresses toward the threshold dose for tumorigenesis. On the other hand, constitutive levels of nitrosamine dealkylase are identical in the 2 species and remain essentially unchanged following administration of DEN for 10 weeks. Inasmuch as nitrosamine dealkylation represents activating metabolism, this provides a rationale for the comparable susceptibility of the rat and guinea-pig to DEN carcinogenesis. Of the 2 enzymes in the 2 species, it is only azo

  5. [Ultrastructural analysis of anastomosis group 9 of Rhizoctonia solani].

    PubMed

    Cedeño, L; Palacios Prü, E

    1996-01-01

    The ultrastructure of R. solani AG-9 (S-21, ATCC 62804) was investigated with transmission electron microscopy (TEM). The most important characteristics were those related with cell wall thickness, cytoplasmic matrix composition, number of nuclei and nucleoli and secretory material production. The majority of examined hyphae showed lateral cell walls thinner than those recorded before. The cytoplasmic matrix consistently appeared differentiated into two classes, one formed by a highly electron dense granular fine material and the other one showing a coloidal substance of very low density which give these cells a 'tiger-like' aspect. The grannular dense matrix always had abundant free ribosomes and usually surrounded the cytoplasmic organelles and the septal pore apparatus. The somatic cells showed up to 5 nuclei, some of which with three nucleoli. Masses of secretory material surrounded by membrane were regularly seen in the cytoplasm, with sizes similar to those of nuclei. PMID:9334448

  6. Rat limb unloading - Soleus histochemistry, ultrastructure, and electromyography

    NASA Technical Reports Server (NTRS)

    Riley, D. A.; Slocum, G. R.; Bain, J. L. W.; Sedlak, F. R.; Sowa, T. E.

    1990-01-01

    The effects of hindlimb unloading on rat-soleus histochemisty, ultrastructure, and electromyogram (EMG) activity were investigated. It was found that, after 14 days of tail suspension, the area of type I and type IIa muscle fibers decreased by 63 and 47 percent, respectively, mainly due to the degradation of subsarcolemmal mitochondria and myofibrils. After 10 days, 3 percent of type IIa fibers exhibited segmental necrosis. After four days, video monitoring revealed abnormal plantar flexion of the hindfeet, which shortened the soleus working range. The EMG activity shifted from tonic to phasic, and aggregate activity decreased drastically after only seven days. The results indictate that the pathological changes in the soleus resulted from unloaded contractions, reduced use, compromised blood flow, and shortened working length.

  7. Mesocestoides lineatus (Goeze, 1782) (Mesocestoididae): new data on sperm ultrastructure.

    PubMed

    Miquel, Jordi; Eira, Catarina; Swiderski, Zdzisław; Conn, David Bruce

    2007-06-01

    Spermiogenesis and the ultrastructural characters of the spermatozoon of Mesocestoides lineatus are described by means of transmission electron microscopy, including cytochemical analysis for glycogen. Materials were obtained from a golden hamster (Mesocricetus auratus) after experimental infection with tetrathyridia metacestodes obtained from naturally infected lizards (Anolis carolinensis) from Louisiana. Spermiogenesis in M. lineatus is characterized by the orthogonal growth of a free flagellum, a flagellar rotation, and a proximodistal fusion. The zone of differentiation contains 2 centrioles associated with striated rootlets and a reduced intercentriolar body. The mature spermatozoon of M. lineatus lacks a mitochondrion, and it is characterized by the presence of (1) a single, spiraled, crested body 150 nm thick; (2) a single axoneme of the 9+'1' pattern of trepaxonematan Platyhelminthes; (3) a parallel and reduced row of submembranous cortical microtubules; (4) a spiraled cordon of glycogen granules; and (5) a spiraled nucleus encircling the axoneme. PMID:17626346

  8. Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

    NASA Astrophysics Data System (ADS)

    Farsad, Nikrooz

    Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the byssus revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

  9. Advances in imaging ultrastructure yield new insights into presynaptic biology

    PubMed Central

    Bruckner, Joseph J.; Zhan, Hong; O’Connor-Giles, Kate M.

    2015-01-01

    Synapses are the fundamental functional units of neural circuits, and their dysregulation has been implicated in diverse neurological disorders. At presynaptic terminals, neurotransmitter-filled synaptic vesicles are released in response to calcium influx through voltage-gated calcium channels activated by the arrival of an action potential. Decades of electrophysiological, biochemical, and genetic studies have contributed to a growing understanding of presynaptic biology. Imaging studies are yielding new insights into how synapses are organized to carry out their critical functions. The development of techniques for rapid immobilization and preservation of neuronal tissues for electron microscopy (EM) has led to a new renaissance in ultrastructural imaging that is rapidly advancing our understanding of synapse structure and function. PMID:26052269

  10. Sperm ultrastructure of the hydrothermal vent octopod Vulcanoctopus hydrothermalis.

    PubMed

    Roura, A; Guerra, A; González, A F; Pascual, S

    2010-08-01

    Sperm ultrastructure of the deep-sea hydrothermal vent octopod Vulcanoctopus hydrothermalis has been carried out by transmission electron microscopy. Spermatozoa of this species have the shortest head observed so far in octopodids. The acrosome possesses a helix with six gyres. The rod-shaped nucleus is short and wide in relation with other octopodids. Noteworthy features along the nucleus are the regularly disposed dense bands of cytoplasm, which have not been observed before in octopodids. The nuclear fossa is very short and wavy. Mitochondrial sheath has 10 elongated mitochondria running parallel to the axoneme-coarse fibers complex. Sperm morphology of V. hydrothermalis resembles that of Enteroctopus dofleini, suggesting a close phylogenetic relationship. PMID:20623654

  11. Comparative ultrastructure of pretarsi in five calyptrate species.

    PubMed

    Wang, Q K; Yang, Y Z; Li, X Y; Li, K; Zhang, D

    2016-06-01

    Pretarsi are the most important structures that allow flies to walk on various smooth surfaces and act as contact sensory organs. The pretarsal ultrastructure, including adhesive pads, claws, unguitractors, and bristles, of five calyptrate species are presented and described in detail, including Calliphora calliphoroides (Rohdendorf, 1931), Lucilia sericata (Meigen, 1826), Sarcophaga portschinskyi (Rohdendorf, 1937), Muscina stabulans (Fallen, 1817) and Portschinskia magnifica Pleske, 1926. Two types of tenent setae (spoon-tipped and spatula-tipped) are present on the ventral side of pulvilli in all species. The density of tenent setae and the pulvilli area in forelegs, midlegs, and hindlegs of both sexes are different. Among the five species, Ca. calliphoroides has unusually large pulvilli to its body size. These results provide morphological details that help to understand the movement and attachment of flies. PMID:26916893

  12. Ultrastructure of extrusomes in hypotrichous ciliate Pseudourostyla nova

    NASA Astrophysics Data System (ADS)

    Zhou, Yao; Wang, Zhengjun; Zhang, Jun; Gu, Fukang

    2011-01-01

    The ultrastructure of extrusomes of the hypotrichous ciliate Pseudourostyla nova was observed in scanning and transmission electron microscopy and enzyme-cytochemistry. The results show that the distribution, morphological characteristics, morphogenesis process, and extrusive process of the extrusomes in P. nova are different from the trichocysts in Paramecium, suggesting that the extrusomes of P. nova can respond to environmental stimuli, play an important role in the defense of this species, and cannot be regarded as "trichocysts". The results also suggest that the extrusomes might be originated from the Golgi apparatus and mature in the cytoplasm; after the extrusion of mature extrusomes, the residual substance might be reabsorbed and reused by the ciliate cell via food vacuoles, and take part in material recycling of the cell.

  13. Methanococcus vannielii: ultrastructure and sensitivity to detergents and antibiotics.

    PubMed Central

    Jones, J B; Bowers, B; Stadtman, T C

    1977-01-01

    Methanococcus vannielii is a strictly anaerobic motile coccus that possesses a tuft of flagellae. The cells are markedly sensitive to mechanical stress and are readily lysed by detergents, but the organism grows normally in media of low ionic strength. The absence of a typical cell wall, further suggested by resistance of M. vannielii to penicillin, cycloserine, and vancomycin, was confirmed by ultrastructural studies. Electron micrographs showed that the cell envelope lacks a peptidoglycan layer. On the outer surface there is a regular array of subunits similar to those of the glycoprotein envelopes of the halobacteria. However, the M. vannielii cell envelope, unlike those of the holobacteria, is unable to maintain a definite shape, and a high salt concentration is not required for its integrity. Images PMID:863858

  14. Black thyroid: clinical manifestations, ultrastructural findings, and possible mechanisms

    SciTech Connect

    Alexander, C.B.; Herrera, G.A.; Jaffe, K.; Yu, H.

    1985-01-01

    Ultrastructural examination of three black thyroid glands showed lysosomal accumulations of lipofuscin-like pigment and granular electron-dense material in association with 1) a minocycline-associated black thyroid with normal thyroid function; 2) a minocycline-associated black thyroid with a significant inflammatory component, fibrosis, and primary hypothyroidism; and 3) a black thyroid gland with no exposure to minocycline. The deposition of the pigments in the three cases resulted in macroscopically recognizable black thyroid glands. It is speculated that an imbalance in lysosomal function accounts for this abnormality. The glandular hypofunction documented in case 2 is unique and confirms the need to monitor function carefully in patients who are receiving minocycline. In one case electrondense deposits were identified in the thyroid gland interstitium.

  15. The ultrastructural study of tumorigenic cells using nanobiomarkers.

    PubMed

    Pavon, Lorena Favaro; Marti, Luciana Cavalheiro; Sibov, Tatiana Tais; Malheiros, Suzana M F; Oliveira, Daniela Mara; Guilhen, Daiane Donna; Camargo-Mathias, Maria Izabel; Amaro Junior, Edson; Gamarra, Lionel Fernel

    2010-06-01

    Despite recent advances, patients with malignant brain tumors still have a poor prognosis. Glioblastoma (WHO grade 4 astrocytoma), the most malignant brain tumor, represents 50% of all astrocytomas, with a median survival rate of <1 year. It is, therefore, extremely important to search for new diagnostic and therapeutic approaches for patients with glioblastoma. This study describes the application of superparamagnetic nanoparticles of iron oxide, as well as monoclonal antibodies, of immunophenotypic significance, conjoined to quantum dots for the ultrastructural assessment of glioblastoma cells. For this proposal, an immunophenotypic study by flow cytometry was carried out, followed by transmission electron microscopy analysis. The process of tumor cell labeling using nanoparticles can successfully contribute to the identification of tumorigenic cells and consequently for better understanding of glioblastoma genesis and recurrence. In addition, this method may help further studies in tumor imaging, diagnosis, and prognostic markers detection. PMID:20578834

  16. Ultrastructural observations on the caecum of the rabbit.

    PubMed Central

    Ross, J A; Scott, A; Gardner, I C

    1989-01-01

    The caecal mucosa of the rabbit has been studied using transmission electron microscopy and its fine structure is considered in the light of its known secretory and absorptive capacities. The luminal surface consists of columnar absorptive epithelium while the crypts are lined with glandular epithelium comprising undifferentiated cells, goblet cells containing dark and light mucigenous granules, and intra-epithelial cells. Endocrine cells occur more commonly in the cryptal epithelium and two cell types have been recognised which correspond to EC and L cells respectively. The lamina propria includes lymphocytes, plasma cells, mast cell and smooth muscle cells. There is little ultrastructural variation within mucosal cells along the length of the caecum. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:2606789

  17. Desmograptus. micronematodes, a silurian dendroid graptolite, and its ultrastructure

    USGS Publications Warehouse

    Saunders, K.M.; Bates, D.E.B.; Kluessendorf, Joanne; Loydell, David K.; Mikulic, Donald G.

    2009-01-01

    Desmograptus micronematodes from Thornton quarry, Cook County, Illinois, USA, remarkably preserved in relief and encased in pyrite, is described. The internal details of the thecae, and of the stolon system, examined using the SEM, allow the reconstruction of the growth of a stipe. The stolons and stolonal nodes are formed of a dense crassal fabric, and are surrounded by a loose fabric of three-dimensional fibrils. The nodes have a complex structure of three boxes with proximal and distal nozzles. The base of a bitheca, and the base of each autothecal cup, has a central nozzle surrounded by a unique honeycomb fabric. The ultrastructure of the cortical fibrils, with their clockwise striations, is similar to that in Dendrograptus, and may be universal in the graptolites. The nodes of the stolon system appear identical to those of Acanthograptus and other dendroids, but differ from those of the extant hemichordate Rhabdopleura, which have only a diaphragm, and lack box structures. ?? The Palaeontological Association, 2009.

  18. Ultrastructural pathology of human liver in Rift Valley fever.

    PubMed

    Shraim, Mubarak Al; Eid, Refaat; Radad, Khaled; Saeed, Noora

    2016-01-01

    Rift Valley fever (RVF) is a zoonotic disease that primarily affects ruminant animals and can also cause fatal disease in humans. In the current report, we present the ultrastructural changes in the liver of a man aged 60 years who died from RVF in the Aseer Central Hospital, Abha, Saudi Arabia. The main hepatic changes by transmission electron microscopy included the presence of 95-115 nm electron-dense particles consistent with RVF virions, nuclear condensation, vacuolar degeneration, lipid droplet accumulation and mitochondrial damage and dilation. There were also viral inclusion bodies with electron-dense aggregates, dilation of intercellular spaces, damage of sinusoidal microvilli with widening of space of Disse, dilation of bile canaliculi and increasing number of phagolysosomes. PMID:27485877

  19. Ultrastructure of the mandibular gland of the ant Myrmoteras iriodum.

    PubMed

    Billen, Johan; Hashim, Rosli; Ito, Fuminori

    2016-07-01

    The mandibular gland in workers of the formicine ant Myrmoteras iriodum differs from other ants both in its general morphology and ultrastructural organization. The secretory cells appear in a pseudo-epithelial arrangement that gives them a clear polarity. At their apical side, the cells are characterized by a large cup-like extension of the reservoir, from which a bulbous invagination connects to a branched end apparatus. At the basal side, the cells show a labyrinth of basal invaginations, while the lateral cell contacts show clear interdigitations. The cytoplasmic composition reveals the presence of numerous round or elongate inclusions that contain crystalline material. Microtubules are abundant, and locally fibrillar regions are found. The function of the mandibular gland in M. iriodum has not yet been documented, and should be studied using gland extracts and behavioural observations. PMID:27130260

  20. Microenvironmental stimuli for proliferation of functional islet β-cells

    PubMed Central

    2014-01-01

    Diabetes is characterized by high blood glucose level due to either autoimmune destruction of islet β-cells or insufficient insulin secretion or glucose non-responsive production of insulin by β-cells. It is highly desired to replace biological functional β-cells for the treatment of diabetes. Unfortunately, β-cells proliferate with an extremely low rate. This cellular property hinders cell-based therapy for clinical application. Many attempts have been made to develop techniques that allow production of large quantities of clinically relevant islet β-cells in vitro. A line of studies evidently demonstrate that β-cells can proliferate under certain circumstances, giving the hopes for generating and expanding these cells in vitro and transplanting them to the recipient. In this review, we discuss the requirements of microenvironmental stimuli that stimulate β-cell proliferation in cell cultures. We highlight advanced approaches for augmentation of β-cell expansion that have recently emerged in this field. Furthermore, knowing the signaling pathways and molecular mechanisms would enable manipulating cell proliferation and optimizing its insulin secretory function. Thus, signaling pathways involved in the enhancement of cell proliferation are discussed as well. PMID:24594290

  1. Identification and ultrastructural characterization of a novel virus from fish.

    PubMed

    Granzow, H; Weiland, F; Fichtner, D; Schütze, H; Karger, A; Mundt, E; Dresenkamp, B; Martin, P; Mettenleiter, T C

    2001-12-01

    During routine investigations on fish, a virus (isolate DF 24/00) with novel morphological features and hitherto undescribed morphogenesis was isolated from a white bream (Blicca bjoerkna L.; Teleostei, order Cypriniformes). Cell-free virions consist of a rod-shaped nucleocapsid (120-150x19-22 nm) similar to that seen in baculoviruses. The virion has a bacilliform shape (170-200x75-88 nm) reminiscent of rhabdoviruses with an envelope containing coronavirus-like spikes (20-25 nm). DF 24/00 replicated well in various fish cell lines. Inhibitor studies with 5-iodo-2'-deoxyuridine indicated that the viral genome consists of RNA and chloroform sensitivity correlated with ultrastructural demonstration of enveloped virions. The buoyant density of the virus determined in sucrose was 1.17-1.19 g/ml. Preliminary biochemical characterization revealed the presence of six antigenic glycoproteins, three of which contain sugars with concanavalin-A specificity. Ultrastructurally, morphogenesis of virus progeny was detected only in the cytoplasm. Nucleocapsids were observed to bud through membranes of the endoplasmic reticulum and/or Golgi apparatus into dilated vesicles. Egress of mature virions occurs primarily by exocytosis and, only very rarely, by budding directly at the plasma membrane. Morphologically similar viruses had previously been isolated from grass carp (Ctenopharyngodon idella), blue crab (Callinectis sapidus), European shore crab (Carcinus maenas) and shrimp (Penaeus monodon). To date, none of them has been classified. In summary, the first characterization of a new virus that might represent a member of a novel virus family that has morphological features resembling those found in rhabdo-, corona- and baculoviruses is presented. PMID:11714959

  2. Ultrastructure, ZIO-staining and chromaffinity of gerbil pinealocytes.

    PubMed

    Chau, Y P; Liao, K K; Kao, M H; Huang, B N; Kao, Y S; Lu, K S

    1994-11-01

    The ultrastructure and cytochemistry of the gerbil pineal gland were studied by the conventional electron microscopy, zinc iodide-osmium tetroxide (ZIO) staining and chromaffin reaction. Conventional electron microscopy revealed that the ultrastructure of gerbil pinealocytes are similar to other rodents, i.e., irregular cell contour with numerous cytoplasmic processes, round or oval nucleus and prominent nucleoli, elongated mitochondria with flattened and tubular cristae and dense matrix, well-developed Golgi apparatus and its associated structures, abundant elements of endoplasmic reticulum--both smooth and rough varieties, and bundles of microfilament and microtubule in the cytoplasm. Some pinealocyte processes contain numerous small clear and "slightly coated" vesicles. Numerous profiles of varicosities containing small dense-cored and clear vesicles were frequently encountered. After ZIO treatment, ZIO staining was preferentially localized in the cytoplasm of some, but not all, of the gerbil pinealocytes. Numerous small clear vesicles (30-50 nm in diameter) in the process of the pinealocytes or in the varicosities of the nerve fibers showed strong ZIO-philia. After chromaffin reaction treatment, the number and electron density of small clear and dense-cored vesicles in the profiles of nerve varicosities increased and this indicates that some of the small clear and dense-cored vesicles in the varicosities are reactive. It is thus concluded that (1) the vesicles in the pinealocytes may be rich in cystine and/or cysteine and possibly the organelle is involved in the sequestering calcium ion during the calcification of the pineal concretions, and (2) the small dense-cored and clear vesicles in the nerve fibers in the gerbil pineal parenchyma may contain both serotonin and primary biogenic amines. PMID:7530780

  3. Polysorbate 80 and Helicobacter pylori: a microbiological and ultrastructural study

    PubMed Central

    2012-01-01

    Background The frequent occurrence of chemoresistant strains reduces the chances of eradication of H. pylori infection and prompted the investigation of non-antibiotic substances active against this organism. Some surfactants enhance the effectiveness of antibiotics for their permeabilizing properties towards bacteria. We examined the antimicrobial activity to H. pylori of the surfactant polysorbate 80, used alone and in association with amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracycline. We also aimed to study the ultrastructural alterations caused upon H. pylori by polysorbate 80, alone and in combination with antibiotics. Twenty-two H. pylori strains were tested using the broth dilution method. After incubation, broth from each dilution was subcultured onto agar enriched with foetal bovine serum to determine the minimum bactericidal concentration (MBC). Synergistic effect of polysorbate 80 with antibiotics was investigated by the broth dilution and disc diffusion techniques. Ultrastructural alterations of organisms treated with polysorbate 80, alone and in association with antibiotics were analyzed by transmission electron microscopy. Results MBCs of polysorbate 80 ranged from 2.6 (1.1) μg/ml to 32 (0) μg/ml. Polysorbate 80 exerted a synergistic effect when associated with metronidazole and clarithromycin: polysorbate 80 and metronidazole MBCs decreased by ≥ 4 fold; clarithromycin MBCs for two resistant strains decreased by 20 and 1000 times. The principal alteration caused by polysorbate 80 consisted in the detachment of the outer membrane of bacteria. Conclusions The bactericidal activity of polysorbate 80 and the synergistic effect of the association with metronidazole and clarithromycin could be useful in the treatment of H. pylori infection. PMID:22998649

  4. Ultrastructure of Bonamia sp. in Ostrea chilensis in Chile.

    PubMed

    Lohrmann, K B; Hine, P M; Campalans, M

    2009-07-23

    Oyster Ostrea chilensis samples were collected from Quihua Island, Chile, in December 2003 and February 2005, and examined in May 2004, and March, April and July 2005, for an ultrastructural comparison of the Chilean Bonamia sp. with other Bonamia spp. Only uni-nucleate stages were encountered, except in the July sample. The Chilean parasite differs from B. perspora in the apparent lack of a plasmodial stage and of sporulation. It resembles B. ostreae in size, the low number of mitochondrial profiles, and the prevalence and mean number of lipid droplets. It differs from B. ostreae in the greater prevalence of nuclear membrane-bound Golgi (NM-BG), associated haplosporogenesis, and smaller size of haplosporosomes. The Chilean Bonamia sp. resembles B. exitiosa in the number of haplosporosomes, prevalence of lipid droplets, anastomosing endoplasmic reticulum and NM-BG, presence of circles of smooth endoplasmic reticulum (sER), confronting cisternae (CC), and cylindrical CC (CCC). It also appears to have a similar developmental cycle to B. exitiosa with larger forms occurring in winter (August). The circles of sER, CC, and CCC have only been reported from B. exitiosa, and it appears that Chilean Bonamia sp. and B. exitiosa are more closely related than they are to B. perspora or B. ostreae. Similarities in ultrastructure and developmental stages between New Zealand and Chilean parasites suggest that the 2 species are related, and that the Chilean Bonamia sp. is either B. exitiosa, a sub-species of B. exitiosa, or a separate species closely related to B. exitiosa. PMID:19750808

  5. Ultrastructural Variability of the Exosporium Layer of Clostridium difficile Spores.

    PubMed

    Pizarro-Guajardo, Marjorie; Calderón-Romero, Paulina; Castro-Córdova, Pablo; Mora-Uribe, Paola; Paredes-Sabja, Daniel

    2016-01-01

    The anaerobic sporeformer Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea in developed and developing countries. The metabolically dormant spore form is considered the transmission, infectious, and persistent morphotype, and the outermost exosporium layer is likely to play a major role in spore-host interactions during the first contact of C. difficile spores with the host and for spore persistence during recurrent episodes of infection. Although some studies on the biology of the exosporium have been conducted (J. Barra-Carrasco et al., J Bacteriol 195:3863-3875, 2013, http://dx.doi.org/10.1128/JB.00369-13; J. Phetcharaburanin et al., Mol Microbiol 92:1025-1038, 2014, http://dx.doi.org/10.1111/mmi.12611), there is a lack of information on the ultrastructural variability and stability of this layer. In this work, using transmission electron micrographs, we analyzed the variability of the spore's outermost layers in various strains and found distinctive variability in the ultrastructural morphotype of the exosporium within and between strains. Through transmission electron micrographs, we observed that although this layer was stable during spore purification, it was partially lost after 6 months of storage at room temperature. These observations were confirmed by indirect immunofluorescence microscopy, where a significant decrease in the levels of two exosporium markers, the N-terminal domain of BclA1 and CdeC, was observed. It is also noteworthy that the presence of the exosporium marker CdeC on spores obtained from C. difficile biofilms depended on the biofilm culture conditions and the strain used. Collectively, these results provide information on the heterogeneity and stability of the exosporium surface of C. difficile spores. These findings have direct implications and should be considered in the development of novel methods to diagnose and/or remove C. difficile spores by using exosporium proteins as targets. PMID

  6. Ultrastructural features of spermatogenesis in Melanorivulus punctatus (Cyprinodontiformes: Rivulidae).

    PubMed

    Cassel, Mônica; Ferreira, Adelina; Mehanna, Mahmoud

    2014-07-01

    Fish belonging to the family Rivulidae possess one of the most complex reproductive systems. Rivulus, a genus of freshwater fish in the Rivulidae family, was recently reclassified into five genera, including Melanorivulus. Its type species, M. punctatus, is widely distributed and probably represents a species complex. The ultrastructure of sperm has been broadly used in systematics, and we hereby describe the ultrastructural features of spermatogenesis in M. punctatus. Ten M. punctatus males were collected from the reservoir of Parque Estadual da Quineira, municipality of Chapada dos Guimarães, Mato Grosso, Brazil, and prepared for analysis by light microscopy and transmission electron microscopy. M. punctatus undergoes cystic spermatogenesis. Its cysts consist of groups of germ cells that are in synchronous development and are surrounded by cytoplasmic projections of Sertoli cells. With the breakdown of the cysts, the spermatozoa are released and their maturation is completed in the duct, where part of the cytoplasmic material is discarded through the vesicles. The mature spermatozoon is characterized by a spherical head with homogeneously condensed chromatin, a symmetric midpiece consisting of a pair of perpendicular centrioles, a ring of mitochondria, several vesicles, and one flagellum medial to the nucleus. Early stages of spermatogenesis show no peculiarities; however, in spermiogenesis, we observed that the spermatids remain interconnected by cytoplasmic bridges and have pockets of residual cytoplasm. The sperm is of the aquasperm type and is similar to that observed in the members of the family Rivulidae. The spermatozoa have a single flagellum that consists of a classic axoneme (9+2), as found in most groups of fish, despite the lateral extensions. PMID:24811986

  7. Ultrastructural, Cytochemical, and Radioautographic Localization of Placental Iron

    PubMed Central

    Parmley, Richard T.; Barton, James C.; Conrad, Marcel E.

    1981-01-01

    Maternal-fetal iron transfer across the guinea pig hemomonochorial placenta during the first, second, and third trimesters was examined using ultrastructural, cytochemical, radioautographic, and ferrokinetic methods. Acid ferrocyanide stained inorganic ferric iron on and in sinusoidal microvilli, cytoplasmic matrix or ground substance, and the outer basal plasmalemma of epithelial cells. Some stain deposits were observed within and on either side of the basement membrane. The extraluminal outer plasmalemma, intercellular junctions, and cytoplasm of endothelial cells frequently contained numerous stain deposits. Staining of trophoblast sinusoidal microvilli was similar during early and late gestation, whereas the staining of the basement membrane and endothelial cells was most prominent during the second and third trimesters. Staining of ferric iron was encountered in rare cytoplasmic granules of epithelial cells during late gestation, but not during early gestation. Placental macrophages contained acid-ferrocyanide-reactive ferric iron in large heterophagosomes and hyaloplasm. Acid ferricyanide failed to localize ferrous iron in either epithelial cells or macrophages. Light-microscopic radioautographic studies localized radioiron in placental epithelial cells and Prussian-blue-positive macrophages in specimens obtained 30 minutes after injection of radioiron (55Fe, 59Fe) into the maternal saphenous vein. At the ultrastructural level labeling was observed (in order of decreasing grain density) in or on the epithelial basal plasmalemma and basement membrane, endothelial cytoplasm, epithelial sinusoidal microvilli, and epithelial cytoplasm. Significant staining or radiolabeling was not observed in mitochondria, trophoblast granules, or nuclei. These results indicate that placental non-heme iron is trivalent and moves from the maternal to the fetal circulation by passing through trophoblast microvilli, cytoplasmic matrix, basal plasmalemma, basement membrane

  8. Brush cells in the human duodenojejunal junction: an ultrastructural study

    PubMed Central

    Morroni, Manrico; Cangiotti, Angela Maria; Cinti, Saverio

    2007-01-01

    Brush cells have been identified in the respiratory and gastrointestinal tract mucosa of many mammalian species. In humans they are found in the respiratory tract and the gastrointestinal apparatus, in both the stomach and the gallbladder. The function of brush cells is unknown, and most morphological data have been obtained in rodents. To extend our knowledge of human brush cells, we performed an ultrastructural investigation of human small intestine brush cells. Six brush cells identified in five out of more than 300 small intestine biopsies performed for gastrointestinal tract disorders were examined by transmission electron microscopy. Five brush cells were located on the surface epithelium and one in a crypt. The five surface brush cells were characterized by a narrow apical pole from which emerged microvilli that were longer and thicker than those of enterocytes. The filamentous core extended far into the cell body without forming the terminal web. Caveolae were abundant. Filaments were in the form of microfilaments and intermediate filaments. Cytoplasmic projections containing filaments were found on the basolateral surface of brush cells. In a single cell, axons containing vesicles and dense core granules were in close contact both with the basal and the lateral surface of the cell. The crypt brush cell appeared less mature. We concluded that human small intestine brush cells share a similar ultrastructural biology with those of other mammals. They are polarized and well-differentiated cells endowed with a distinctive cytoskeleton. The observation of nerve fibres closely associated with brush cells, never previously described in humans, lends support to the hypothesis of a receptor role for these cells. PMID:17509089

  9. Grappling archaea: ultrastructural analyses of an uncultivated, cold-loving archaeon, and its biofilm

    PubMed Central

    Perras, Alexandra K.; Wanner, Gerhard; Klingl, Andreas; Mora, Maximilian; Auerbach, Anna K.; Heinz, Veronika; Probst, Alexander J.; Huber, Harald; Rachel, Reinhard; Meck, Sandra; Moissl-Eichinger, Christine

    2014-01-01

    Similarly to Bacteria, Archaea are microorganisms that interact with their surrounding environment in a versatile manner. To date, interactions based on cellular structure and surface appendages have mainly been documented using model systems of cultivable archaea under laboratory conditions. Here, we report on the microbial interactions and ultrastructural features of the uncultivated SM1 Euryarchaeon, which is highly dominant in its biotope. Therefore, biofilm samples taken from the Sippenauer Moor, Germany, were investigated via transmission electron microscopy (TEM; negative staining, thin-sectioning) and scanning electron microscopy (SEM) in order to elucidate the fine structures of the microbial cells and the biofilm itself. The biofilm consisted of small archaeal cocci (0.6 μm diameter), arranged in a regular pattern (1.0–2.0 μm distance from cell to cell), whereas each archaeon was connected to 6 other archaea on average. Extracellular polymeric substances (EPS) were limited to the close vicinity of the archaeal cells, and specific cell surface appendages (hami, Moissl et al., 2005) protruded beyond the EPS matrix enabling microbial interaction by cell-cell contacts among the archaea and between archaea and bacteria. All analyzed hami revealed their previously described architecture of nano-grappling hooks and barb-wire basal structures. Considering the archaeal cell walls, the SM1 Euryarchaea exhibited a double-membrane, which has rarely been reported for members of this phylogenetic domain. Based on these findings, the current generalized picture on archaeal cell walls needs to be revisited, as archaeal cell structures are more complex and sophisticated than previously assumed, particularly when looking into the uncultivated majority. PMID:25140167

  10. Ultrastructure and post-floral secretion of the pericarpial nectaries of Erythrina speciosa (Fabaceae)

    PubMed Central

    Paiva, Elder Antônio Sousa

    2009-01-01

    Background and Aims The occurrence of nectaries in fruits is restricted to a minority of plant families and consistent reports of their occurrence are not found associated with Fabaceae, mainly showing cellular details. The present study aims to describe the anatomical organization and ultrastructure of the pericarpial nectaries (PNs) in Erythrina speciosa, a bird-pollinated species, discussing functional aspects of these unusual structures. Methods Samples of floral buds, ovaries of flowers at anthesis and fruits at several developmental stages were fixed and processed by the usual methods for studies using light, and scanning and transmission electron microscopy. Nectar samples collected by filter paper wicks were subjected to chemical analysis using thin-layer chromatography. Key Results The PNs are distributed in isolation on the exocarp. Each PN is represented by a single hyaline trichome that consists of a basal cell at epidermal level, stalk cell(s) and a small secretory multicellular head. The apical stalk cell shows inner periclinal and anticlinal walls impregnated by lipids and lignin and has dense cytoplasm with a prevalence of mitochondria and endoplasmic reticulum. The secretory cells show voluminous nuclei and dense cytoplasm, which predominantly has dictyosomes, rough endoplasmic reticulum, plastids, mitochondria and free ribosomes. At the secretory stage the periplasmic space is prominent and contains secretion residues. Tests for sugar indicate the presence of non-reducing sugars in the secretory cells. Nectar samples from PNs contained sucrose, glucose and fructose. Conclusions The secretory stage of these PNs extends until fruit maturation and evidence suggests that the energetic source of nectar production is based on pericarp photosynthesis. Patrolling ants were seen foraging on fruits during all stages of fruit development, which suggests that the PNs mediate a symbiotic relationship between ants and plant, similar to the common role of many

  11. [ULTRASTRUCTURAL CHANGES OF THE STEM CELLS IN THE CYCLE MONOLAYER--SPHERES--MONOLAYER].

    PubMed

    Martynova, M G; Krylova, T A; Bystrova, O A

    2016-01-01

    Sphere formation can be used to prepare stem cells (SCs) prior to transplantation. Here SCs isolated from human subepicardial adipose tissue were analyzed at different stages of the monolayer-spheres-monolayer cycle by transmission electron microscopy. The results obtained with both adherent-induced and hanging-drop induced spheres were similar. At first 2-3 passages (stage 1), isolated SCs displayed embryonal cell-like ultrastructure. With increasing passage times (stage 2), SCs became bigger and more electron-dark with a multilobed nucleus, well-developed rough endoplasmic reticulum (RER), prominent Golgi apparatus and numerous vacuoles. After 2 h from the initiation of the formation of spheres (stage 3), SCs gathered into clusters and formed desmosome-like intercellular contacts. Their nucleus possessed a large loose fibrillo-granular nucleoli, the cytoplasm was densely packed with disintegrated cisternae of RER, Golgi apparatus was not detected. After 24 h from the initiation of spheres (stage 4), SCs in well-formed spheres exhibited large dense nucleoli and poorly developed Golgi apparatus and RER. One day after sphere dissociating (stage 5), SCs were embryonal cell-like and morphologically similar to the cells of the first stage except for the presence of a large nucleolus and numerous Golgi complexes. After 48 h from sphere dissociating (stage 6), SCs became electron-dark and resembled the SCs of the second stage by the presence of irregularly shaped nuclei and the cetoplasm filled with RER. We interpreted the results as senescence of the SCs with the number of passages after isolation from tissue and a day after dissociation of the spheres and as rejuvenation of the SCs just after sphere dissociation. Further research is needed to reveal the genetic, biochemical and physiological parameters of the SCs on established morphologically distinct stages in order to provide higher-quality cellular material for disease cell therapy. PMID:27220247

  12. Ultrastructural morphometry of capillary basement membrane thickness in normal and transgenic diabetic mice.

    PubMed

    Carlson, Edward C; Audette, Janice L; Veitenheimer, Nicole J; Risan, Jessica A; Laturnus, Donna I; Epstein, Paul N

    2003-04-01

    Capillary basement membrane (CBM) thickening is an ultrastructural hallmark in diabetic patients and in animal models of diabetes. However, the wide variety of tissues sampled and diverse methods employed have made the interpretation of thickness data difficult. We showed previously that acellular glomerular BMs in OVE26 transgenic diabetic mice were thickened beyond normal age-related thickening, and in the current study we hypothesized that other microvascular BMs likewise would show increased widths relative to age-matched controls. Accordingly, a series of tissues, including skeletal and cardiac muscle, ocular retina and choriod, peripheral nerve, lung, pancreas, and renal glomerulus was collected from 300-350-day-old normal and transgenic mice. Transmission electron micrographs of cross sections through capillary walls were prepared, and CBM thickness (CBMT) was determined by the "orthogonal intercept" method. Morphometric analyses showed highly variable transgene-related BMT increases in the sampled tissues, with glomerular BM showing by far the greatest increase (+87%). Significant thickness increases were also seen in the retina, pulmonary alveolus, and thoracoabdominal diaphragm. BMT increases were not universal; however, most were modestly widened, and those that were thickest in controls generally showed the greatest increase. Although the pathogenesis of diabetes-related increases in CBM is poorly understood, data in the current study showed that in OVE26 transgenic mice increased BMT was a frequent concomitant of hyperglycemia. Accordingly, it seems likely that hyperglycemia-induced microvascular damage may be a contributing factor in diabetic BM disease, and that microvessel cellular and extracellular heterogeneity may limit the extent of CBM thickening in diverse tissues. PMID:12629676

  13. 3D-Ultrastructure, Functions and Stress Responses of Gastropod (Biomphalaria glabrata) Rhogocytes

    PubMed Central

    Kokkinopoulou, Maria; Güler, M. Alptekin; Lieb, Bernhard; Barbeck, Mike; Ghanaati, Shahram; Markl, Jürgen

    2014-01-01