Gorm Danscher | Aarhus University (original) (raw)

Papers by Gorm Danscher

Autometallography method with intraperitoneal injedlon of sodium selenite was employed to investi... more Autometallography method with intraperitoneal injedlon of sodium selenite was employed to investigate the localization of somata of zinc enriched (ZEN) neurons in the medulla oblongata The distribution patterns of the labeled neurons were variable from rostral to caudal regions. The labeled cells by the method were found in Cl adrenaline cells, gigantocellular reticular nucleus, inferior olive, paragigantocellular nucleus, prepositus hypoglossal nucleus, raphe obscurus nucleus, and reticular nucleus regions.

Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to so... more Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to some metalloproteins and nucleic acids, loosely bound to some metallothioneins or even as free ion. Small amounts of zinc ions (in the nanomolar range) regulate a plentitude of enzymatic proteins, receptors and transcription factors, thus rolls need accurate homeostasis of zinc ions. Zinc is an essential catalytic or structural element of many proteins, and a signaling messenger that is released by neural activity at many central excitatory synapses. Growing evidences suggest that zinc may also be a key mediator and modulator of the neuronal death associated with transient global ischemia and sustained seizures, as well as perhaps other neurological disease stoles. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartment ('vesicular zinc') which can be evidenced using histochemical techniques. Substances giving a bright colour or emitting fluoresce...

Journal of Biotechnology, 2017

According to OIE and WHO recommendations "gold standard" for rabies diagnosis is Fluorescent Anti... more According to OIE and WHO recommendations "gold standard" for rabies diagnosis is Fluorescent Antibody Test (FAT) on brain tissue. Inconclusive results are confirmed with the Mouse Inoculation Test (MIT) or Virus Isolation in Cell Culture (Rabies Tissue Culture Infective Test-RTCIT). However, for ethical reasons and animal welfare, OIE manual clearly mentions that wherever possible, RTCIT should replace mouse inoculation tests. The objective of this paper was to compare the costs of the RTCIT and MIT for rabies diagnosis in the Romanian context. In theory, a brain sample analyzed by the RTCIT costs 50% less than one analyzed by MIT. However, based on Rabies epidemiological situation and also according to the network of the 40-county sanitary veterinary laboratories existing in Romania, the discussion still needs debate, regarding at least, the implementation cost of RTCIT at the county level.

Histochemistry and Cell Biology, Mar 2, 2023

The newest data on metallic gold have placed the noble metal central in the fight for the safe tr... more The newest data on metallic gold have placed the noble metal central in the fight for the safe treatment of autoimmune inflammation. There are two different ways to use gold for the treatment of inflammation: gold microparticles > 20 µm and gold nanoparticles. The injection of gold microparticles (µGold) is a purely local therapy. µGold particles stay put where injected, and gold ions released from them are relatively few and taken up by cells within a sphere of only a few millimeters in diameter from their origin particles. The macrophage-induced release of gold ions may continue for years. Injection of gold nanoparticles (nanoGold), on the other hand, is spread throughout the whole body, and the bio-released gold ions, therefore, affect multitudes of cells all over the body, as when using gold-containing drugs such as Myocrisin. Since macrophages and other phagocytotic cells take up and transport nanoGold and remove it after a short period, repeated treatment is necessary. This review describes the details of the cellular mechanisms that lead to the bio-release of gold ions in µGold and nanoGold.

Histochemistry (Berlin), 1981

A method is described that visualizes trace amounts of silver in frozen, paraffin and epon sectio... more A method is described that visualizes trace amounts of silver in frozen, paraffin and epon sections from biological tissue. After exposure to light, which ensures reduction of silver ions that are not bound to sulphide, histological sections from animals treated with silver compounds are exposed to a photographic developer containing silver ions. Tissue silver acts as a catalyst for the

Histology and histopathology, 2003

Shotgun pellets containing bismuth (Bi) are widely used and may cause a rather intense exposure o... more 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...

Brain Research, Oct 1, 1974

PubMed, Oct 1, 2003

A new autometallographic (AMG) technique for staining myelin in formaldehyde- or paraformaldehyde... more A new autometallographic (AMG) technique for staining myelin in formaldehyde- or paraformaldehyde- (PFA) fixed tissue is presented. The tissue sections were exposed to AMG development without prior treatment with silver salts. The method was examined on PFA-fixed tissue from mouse, rat, pig, and formaldehyde-fixed human autopsy material. Samples from brain, spinal cord, cranial, and spinal nerves were either cut on a vibratome, frozen and cryostat sectioned, or embedded and microtome sectioned, before AMG development and counterstaining. The AMG-myelin technique results in a specific black/dark-brown staining of myelin in all parts of the CNS and PNS. It works on all species examined, independent of the histological preparation techniques applied. The AMG staining is stable, stays unchanged through decades, allows counterstaining, and has previously been used with immunohistochemical techniques. On perfusion-fixed tissue the technique works without further fixation, but the intensity of the AMG-myelin staining is increased by increased postfixation time. Additionally, immersion fixation has to last for days depending on the size of the tissue block in order to obtain proper myelin staining. The most feasible explanation of the chemical events underlying the AMG-myelin technique is that nano-sized clusters of metallic silver are formed in the myelin as a result of chemical bounds with reducing capacity, exposed or created by the formaldehyde molecule. The AMG method is simple to perform and as specific as the conventional osmium and luxol fast blue stainings. The present technique is thus an effective, simple, inexpensive, and quick myelin staining method of formaldehyde- or PFA-fixed tissue.

Brain Research, Jun 1, 2000

The rat spinal cord reveals a complex pattern of zinc-enriched (ZEN) boutons. As a result of in v... more The rat spinal cord reveals a complex pattern of zinc-enriched (ZEN) boutons. As a result of in vivo exposure to selenide ions, nanosized clusters of zinc selenide are created in places where zinc ions are present, including the zinc-containing synaptic vesicles of ZEN boutons. The clusters can be silver enhanced by autometallographic (AMG) development. A description of the ZEN bouton patterns is presented and discussed. The distribution of ZEN boutons could indicate that these terminal systems have a differentiated influence on sensory and motor systems.

Acta Histochemica Et Cytochemica, 1997

Zinc ions have been demonstrated in the anterior pituitary of rat by autometallography (AMG) whic... more Zinc ions have been demonstrated in the anterior pituitary of rat by autometallography (AMG) which involves in vivo exposure to sodium selenite leading to creation of zinc selenide crystal lattices that are later silver enhanced by AMG in the sections. In this study, autometallography is combined with immunohistochemistry in order to present the coexistence of zinc ions and hormones in endocrine cells of the rat pituitary. The results showed that the majority of zincenriched (ZEN) cells are somatotrophs. All the somatotrophs observed were loaded with AMG grains. Zinc ions were also found to be present in gonadotrophs, corticotrophs and thyrotrophs. A low density of AMG silver grains was found in about 60% of gonadotrophs, 8% of corticotrophs and less than 10% of thyrotrophs. Lactotrophs did not appear to contain zinc ions. The present observations may provide a clue to the physiological function of zinc ions in the rat pituitary.

Journal of Histochemistry and Cytochemistry, Nov 1, 2000

We provide a detailed protocol of the autometallographic bismuth technique and evaluate the speci... more We provide a detailed protocol of the autometallographic bismuth technique and evaluate the specificity of the technique. We show by the multi-element technique "proton-induced X-ray microanalysis" (PIXE) that the autometallographic grains contain silver, bismuth, and sulfur, proving that autometallography can be used for specific tracing of bismuth bound as bismuth sulfide clusters in tissue sections from Bi-exposed animals or humans. In sections from animals exposed concurrently to selenium and bismuth, the autometallographic grains also contain selenium. This demonstrates that, if present in excess in the organisms, selenium will bind to exogenous bismuth, creating bismuth selenide clusters. As a further possible control for specificity and as a tool for differentiating among autometallographically detectable metals in sections containing more than one, we describe how bismuth sulfide clusters can be removed from Epon-embedded tissue sections by potassium cyanide.

Histochemistry and Cell Biology, 1971

Adult albino rats were given single intraperitoneal injections of dithizone in doses from 50 to 2... more Adult albino rats were given single intraperitoneal injections of dithizone in doses from 50 to 200 mg per kg body weight. After intervals of 5 minutes to 28 days, the animals were killed by vascular perfusion with buffered sodium sulfide. Cryostat sections of the brains were prepared and stained according to Timm's procedure. The dithizone treatment after appropriate doses and time intervals virtually prevented the sulfide silver staining of the mossy fiber system and most other parts of the neuropil in the forebrain. The staining of cytoplasmic granules normally associated with neuronal somata throughout the brain, of capillaries, ependyma, and choroid plexus was not unequivocally affected. The results support the idea that the sulfide silver staining throughout most of the forebrain neuropil is due to the presence of metals. The failure of the dithizone treatment to prevent the staining of other parts of the sulfide silver pattern is briefly discussed.

Cell and Tissue Research, 1974

With the present modification of Timm's sulfide silver method all parts of the hippocampal r... more With the present modification of Timm's sulfide silver method all parts of the hippocampal region show a distinctly stratified staining pattern, suggesting large regional differences in the content of heavy metals.

Progress in Histochemistry and Cytochemistry, Sep 1, 2006

Autometallographic (AMG) silver enhancement is a potent histochemical tool for tracing a variety ... more Autometallographic (AMG) silver enhancement is a potent histochemical tool for tracing a variety of metal containing nanocrystals, e.g. pure gold and silver nanoclusters and quantum dots of silver, mercury, bismuth or zinc, with sulphur and/or selenium. These nanocrystals can be created in many different ways, e.g. (1) by manufacturing colloidal gold or silver particles, (2) by treating an organism in vivo with sulphide or selenide ions, (3) as the result of a metabolic decomposition of bismuth-, mercury-or silver-containing macromolecules in cell organelles, or (4) as the end product of histochemical processing of

Birkhäuser Boston eBooks, 1996

In the early eighties, a series of papers were published to introduce a reliable and easy-to-hand... more In the early eighties, a series of papers were published to introduce a reliable and easy-to-handle technique for light microscopical and ultrastructural autometallographic studies. Specific methods were developed to demonstrate endogenous zinc pools of zinc ions in synaptic and secretory vesicles; exogenous mercury, silver bound as sulphide or selenide crystals, in lysosomes; and tissue-bound gold ions resulting from medicamented aurothiocompounds. It was demonstrated that gold ions chemically bound in the lysosomes had to be reduced to metallic gold before they could be silver-amplified. This understanding made it feasible to apply autometallographic amplification for magnifying colloidal-gold particles in thick, semithin and ultrathin sections. As a result, the highly sensitive in situ colloidal gold-labeled detection of peptides, proteins and amines by immunocytochemistry (immuno gold-silver staining [IGSS]), carbohydrates by lectin histochemistry; and DNA and RNA by in situ hybridization, in situ PCR and in situ 3SR techniques were born. Here, we present an overview of the literature on IGSS techniques used for light and electron microscopic studies and also give guidelines for using IGSS based on our own experience.

Advances in pathology, microscopy & molecular morphology, Apr 17, 2002

Neuroscience, Nov 1, 2007

The present study aims at evaluating the significance of zinc ions on the development of brain da... more The present study aims at evaluating the significance of zinc ions on the development of brain damage in a model of traumatic brain injury (TBI). The zinc ion specific autometallographic technique, the ZnSe(AMG) method, using silver enhancement of in vivo-captured zinc ions bound in zinc-selenium nanocrystals was applied to follow changes in the vesicular zinc pattern. Balb/c mice, ZnT3 knockout (ZnT3-Ko) mice, a mouse genetically knocked out for the protein ZnT3 responsible for sequestering zinc into synaptic vesicles, and littermates from the genetically un-manipulated mother type mice, wild type (Wt), were used. The Wt and the Balb/c mice exhibited instantaneously a boost in the zinc staining adjacent to the lesion involving all six neocortical layers. Ultra-structural analyses revealed that the in vivo created ZnSe nanocrystals were still confined to the vesicles of the zinc-enriched (ZEN) neurons in the neuropil. No differences between the Balb/c and Wt mice were seen at any time points. In the ZnT3-Ko mice the ZEN terminals stayed void of AMG grains, but a number of neuronal somata around the lesion became loaded with ZnSe nanocrystals. These silver-enhanced ZnSe nanocrystals were confined to the cytoplasm of the somata and their proximal dendrites. No such soma staining was seen in the Wt or Balb/c mice. We speculate that vesicular zinc may not contribute to neuronal damage following TBI.

Histochemistry (Berlin), 1987

In biological tissue, minute accumulations of gold, silver, mercury and zinc can be visualized by... more In biological tissue, minute accumulations of gold, silver, mercury and zinc can be visualized by a technique whereby metallic silver is precipitated on tiny accumulations of the two noble metals, or on selenites or sulphides of all four metals. In the present study a silver enhancement kit, primarily intended for the amplification of colloidal gold particles, has been used to demonstrate these catalytic tissue metals. Sections from animals exposed intravitally to aurothiomalatate, silver lactate, mercury chloride, sodium selenite or perfused with sodium sulphide were subjected to a commercial silver enhancement kit (IntenSE, Janssen Pharmaceutica). It was found that the kit performs adequately to the silver lactate gum arabic developer and to the photographic emulsion technique. The kit can be used as a silver enhancement medium for the demonstration of zinc by the NeoTimm and selenium methods and for demonstration of gold, silver, and mercury in tissues from animals intravitally exposed to these metals. It can also be used for counterstaining silver treated osmium fixed tissues embedded in plastic. of gold, silver, mercury and zinc also catalytically induce a reduction of silver ions to metallic silver. This is similar to the photographic development process. Silver ions derived from a silver salt dissolved in the developer (" physical development") or from silver bromide crystals in photographic emulsions (" chemical development") adhere firmly to the catalyst. The donatation of electrons from adhering reducing molecules, e.g. hydroquinone, causes the reduction of silver ions to metallic silver. The reaction is in principle the same in both "physical" and "chemical" development and we suggest that the technical term autometattography be employed for techniques where metals or metal containing molecules are made visible by autoinduction or enlarged by silver enhancement (Danscher 1984; Danscher and Norgaard 1985). The visualization by silver amplification of colloidal gold is a type of autometallographic reaction and the commercial enhancement kit should therefore also be able to be used for the visualization of tissue metals. The present study was conducted to test applicability of the commercial product IntenSE in the tissue metal field and the results suggest that it performs adequately both at light and electron microscopic levels.

Journal of Histochemistry and Cytochemistry, Dec 1, 1983

RNase labeled with colloidal gold was used as a model for the present technique evolved for the l... more RNase labeled with colloidal gold was used as a model for the present technique evolved for the light microscopic localization of gold-labeled substances in semithin resinembedded sections. Tissue sections placed on glass slides were treated with the gold-enzyme complex and subsequently exposed to a photographic developer containing silver lactate. During the development gold particles are encapsulated in growing shells of metallic silver and grad