Browsing by Subject "Autometallography"

Now showing 1 - 5 of 5
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    Autometallographic tracing of quantum dots
    (Murcia : F. Hernández, 2007) Stoltenberg, M.; Larsen, Agnete; Doering, P.; Sadauskas, E.; Locht, L.; Danscher, G.
    A short clarifying view of how semiconductor quantum dots (QDs) can be made visible in tissue sections by autometallographic (AMG) silver enhancement and how the introduction of AMG enhanceable gold nanoparticles into isolated cells can be used to follow the fate of these marked cells in organisms and cell cultures. As the AMG approach for visualizing quantum dots is extremely sensitive, QDs less than one nanometer can be made visible at both LM and EM levels.
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    In vivo cellular uptake of bismuth ions from shotgun pellets
    (Murcia : F. Hernández, 2003) Stoltenberg, M.; Locht, L.; Larsen, Agnete; Jensen, D.
    Shotgun pellets containing bismuth (Bi) are widely used and may cause a rather intense exposure of some wild animals to Bi. A Bi shotgun pellet was implanted intramuscularly in the triceps surae muscle of 18 adult male Wistar rats. Another group of 9 animals had a Bi shotgun pellet implanted intracranially in the neocortex. Eight weeks to 12 months later the release of Bi ions was analysed by autometallography (AMG) of tissue sections from different organs (brain, spinal cord, kidney, liver, testes). In the group with intramuscular Bi shotgun pellets no AMG staining could be found for the first 2-4 months; 6 months after exposure Bi was traced in the kidney. Twelve months after the implantation the kidneys were heavily loaded and Bi was also traced in testosterone-producing Leydig cells, in glial cells and in neurons of brain and spinal cord. In the central nervous system (CNS) motor neurons were the most loaded. In rats with intracranially implanted shotgun pellets a massive uptake of Bi was observed involving both glia and neurons throughout the brain. The cells close to the shotgun pellet had the highest uptake. The animals showed a pronounced Bi uptake in the ependyma cells lining the ventricular system and in the cubic epithelia covering the choroid plexus. Dissemination of Bi ions to the rest of the body was demonstrated by AMG tracing of Bi accumulations in the tubular cells of the kidney. These findings emphasize that metallic Bi, including shotgun pellets, represents sites of intense Bi pollution if implanted or shot into a living organism, and further that such metallic Bi bodies, if they enter the CNS, cause a spread of Bi ions throughout it.
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    Toxicological aspects of injectable gold-hyaluronan combination as a treatment for neuroinflammation
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2014) Pedersen, Dan Sonne; Locht, Linda J.; Tran, Thao P.; Markholt, Sara; Rungby, Jørgen; Larsen, Agnete
    Secondary inflammatory reactions to stroke or trauma contribute to irreplaceable loss of brain tissue of the affected patients. Likewise, neuroinflammatory processes are the main pathophysiological feature in Multiple Sclerosis (MS), a common neurodegenerative disease among young adults. In the search for safe and efficient ways to reduce inflammation within nervous tissue older immunosuppressive remedies have been re-investigated. The anti-inflammatory properties of gold salts are well known but result in uncontrollable systemic spread of gold ions, generating side effects such as nephrotoxicity, limiting their use. Recent studies have circumvented this obstacle by introducing metallic gold implants as a localized source of immune-modulating gold ions and suspension in hyaluronic acid (HA) enables injection of small amounts of gold in the natural spaces of the brain. By injecting >25 µm gold beads in HA intracerebrally we recently showed a slowing of disease progression in a rodent model of MS. The toxicological aspects were, however, not assessed. The present study investigates the viability of neuronal and macrophage cell cultures exposed to the gold/HA combination and the possible risk associated with unilateral gold/HA injection in young Balb/CA mice in the first 7 to 21 days of gold-exposure. Tracing by autometallography of gold accumulations throughout the brain exhibited sparse gold uptake in glia and neurons of hippocampus and cortex, and striatum and cerebellum were void of staining. No systemic spread of gold was seen in liver or kidney, nor were there signs of obstruction of the ventricular system. Both cell cultures of J774 macrophages and CCL neurons accumulated gold from gold/HA-exposure with no signs of reduced viability. In conclusion, our findings indicate that gold/HA is not overtly neuro- or cytotoxic, nor does intraventricular exposure result in widespread gold accumulation or tissue damage, warranting further studies into the pharmacological properties of this novel form of gold treatment. Histol Histopathol 29, 447-456 (2014)
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    Tracing the accumulation and effects of mercury uptake in the previtellogenic ovary of crucian carp Carassius auratus gibelio by autometallography and caspase-3 immunohistochemistry
    (Murcia : F. Hernández, 2009) Zarnescu, Otilia
    The aims of the present study were to apply the AMG technique for localization of mercury at the light and electron microscopic level in the ovary of crucian carp after exposure to mercuric chloride and to find out if this heavy metal induces expression of caspase-3. Depending on the stage of ovarian follicle development, two patterns of mercury accumulation have been found in previtellogenic ovary of crucian carp. The first mercury accumulation pattern has been found in the early previtellogenic oocyte without zona radiata. In these oocytes, mercury accumulates into an ooplasmic region that seems to correspond to the Balbiani body (32-65 μm oocyte diameter), throughout the cytoplasm (84-116 μm oocyte diameter) and in the cortical cytoplasm (~180 μm oocyte diameter). The second mercury accumulation pattern has been found in the late previtellogenic oocyte with cortical alveoli (229- 330 μm oocyte diameter). Ultrastructural observations have shown grains of silver-enhanced mercury inside coated vesicles, the cortical lysosome-like bodies or multivesicular bodies and cortical alveoli. Immunohistochemistry reaction for caspase-3 was positive in nuclei of the early previtellogenic oocyte and Balbiani body.
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    ZNT7 and Zn2+ are present in different cell populations in the mouse testis
    (Murcia : F. Hernández, 2009) Chi, Zhi-Hong; Feng, Wan-Yu; Gao, Hui-Ling; Zheng, Wei; Huang, Liping; Wang, Zhan-You
    The aim of the present study was to investigate the relation of the spatial distribution between ZNT7 and chelatable zinc ions in the mouse testis. Immunohistochemical results demonstrated a wide distribution of ZNT7 in both seminiferous tubules and interstitial tissues of the testis. The spermatocytes and spermatids in the seminiferous tubules showed strong ZNT7 immunoreactivity whereas zinc autometallographic (AMG) staining was absent. Spermatozoa showed a high level of free zinc, but were void of ZNT7 immunoreactivity. No ZNT7 immunoreactivity and AMG grains were found in spermatogonia. Both ZNT7 and chelatable zinc were detected in Sertoli and Leydig cells. Furthermore, double immunofluorescence study demonstrated that the ZNT7 staining overlapped with that of TGN38 (a trans-Golgi marker), suggesting that ZNT7 was localized in the Golgi apparatus in the ZNT7- positive cells. In conclusion, ZNT7 and chelatable zinc were distributed in different cell populations except for Sertoli and Leydig cells in the mouse testis. ZNT7 may be involved in zinc transportation into the Golgi apparatus for protein packaging in the mouse testis