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PubMed1998

Light and electron microscopic examination of exocrine pancreas using zinc iodide-osmium tetroxide technique.

Zinc iodide-osmium tetroxide (ZIO) fixation/staining technique is a metallophilic technique which has been used for the examination of various tissues and cell types. We examined the ZIO (+) cell types in rat exocrine pancreas to obtain further evidence for the significance of the reaction. Among mostly non-reactive pancreatic acinar cells there were ZIO (+) acinar cells of varying staining intensity. Zymogenic granules and centroacinar cells were completely non-reactive. Our electron microscopic findings support the view that the reactivity of the technique used is cell specific but not cell type or organelle specific.

Animals↗

PubMed1995

Improved lipid visualization with a modified osmium tetroxide method using ultrasonic treatment and intensification with imidazole or triazole.

Formalin fixed autopsy tissue containing lipids were cut into 1-5 mm thick blocks, washed well, then postfixed in 2% OsO4 in 0.03 M veronal acetate buffer for 30, 60, 90, 120, or 180 min with or without ultrasonic treatment. Tissues exposed to ultrasound for 90 min showed superior penetration of OsO4 and well preserved histological architecture. Tissues also were immersed for 1 hr in veronal acetate buffer (pH 7.4) containing 0.5% imidazole or triazole and compared with untreated controls. Paraffin sections, 4 microns thick, were examined under a light microscope with an image analyzer. Both intensity and percentage area of osmium blackening were significantly higher in samples immersed in imidazole or triazole than in untreated controls. No difference was observed between imidazole- and triazole-immersed samples. The OsO4 method, modified by ultrasound treatment and imidazole- or triazole-immersion, can be applied to routine formalin fixed autopsy materials for improved lipid visualization.

Fatty Liver↗

PubMed1976

Osmium deposits detected by x-ray after synoviorthesis of the knee.

A study of 113 knees of 72 patients treated with intra-articular injection of osmic acid for chronic exudative synovitis caused by various rheumatic diseases is reported. Certain cases presented abnormal radiological opacities, statistically more frequent after the injection of 200 mg than after 100 mg of osmic acid (33.9% and 15.7%). These images appear early after the injection and can remain for years. They should not be confused with intra-articular calcium deposits, or with synovial ossifications or various periosteal osteogenic processes. Their appearance does not seem to be related to the rheumatic disease treated or the therapeutic result obtained. They reflect the fixation of osmium in the synovial fatty tissue, which causes a fibrous reaction at this level. Their longterm action in the cicatrization of the synovia, or their part in a relapse of an inflammatory episode should be clarified.

Adult↗

PubMedDate not supplied

[Optimization of gold immunolabeling techniques on ultrathin slides obtained from samples fixed with glutaraldehyde and osmium tetroxide and enclosed in epoxy resin].

An immunogold labeling technique was carried out on plants infected with CMV, fixed with glutaraldehyde and osmium tetroxide and embedded in araldite CY 212. The effect of the type of support-film used, the resin and manipulations of the grids during immunogold steps, were studied and are discussed. The antigenic activity of virus was restored by treating the sections with sodium metaperiodate. The very high non-specific reactions observed with the support-film or with the resin were eliminated by adding powdered skimmed milk or non-purified albumin into the buffers. Purified bovine serum albumin (grade V) or chicken albumin (grade III to V) were inefficient in reducing this non-specific background.

Antigens, Viral↗

PubMed1990

An osmium-ferricyanide staining method for the intercellular space in the small intestinal epithelium.

The post-fixation with osmium tetroxide and potassium ferricyanide (OsFeCN) produced dense deposits on the outer surface of the lateral plasma membrane in the mouse small intestinal epithelium. The deposits also filled up the intercellular space. No deposits were found on the surface of apical and basal plasma membranes. This staining pattern was highly reproducible when pH of the OsFeCN solution was adjusted to 7.0 by cacodylate buffer without calcium ion. Thus, our modified OsFeCN method is useful to selectively stain the intercellular space in epithelial tissues.

Animals↗

PubMed1990

The tannin-osmium conductive staining after dehydration: an attempt to observe the chromosome structure by SEM without metal coating.

The tannin-osmium conductive staining method was modified in order to observe chromosomal structures without metal coating. The treatment with tannic acid and OsO4, which has been used in aqueous solution in the original method, was performed in acetone solution after dehydration in the present study. The usefulness of this method is discussed showing ultrastructural images of chromosomes of Drosophila and Tradescantia, which can be achieved by the method.

Animals↗

PubMed1991

[Monoclonal antibodies to DNA, modified with osmium tetraoxide in the presence of 2,2'-bipyridine].

A monoclonal antibody (IgG) has been produced that binds to DNA modified with osmium tetroxide and 2,2'-bipyridine and does not react with unmodified DNA and modified or unmodified RNA and proteins. The reaction specificity is due to the presence of the modified deoxythymidine residue within the epitope. Possible use of the antibody for studies of DNA structure and detection of cDNA probes is discussed.

2,2'-Dipyridyl↗

PubMed1990

Correlative light microscopy, scanning electron microscopy, and transmission electron microscopy of osmium-macerated biological tissues.

A method facilitating correlation of light microscopic (LM), scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images was developed. Rat kidney and heart were initially subjected to the osmium maceration procedure and then embedded in acrylic resin. Semithin sections of the tissue blocks were first provided for LM and then examined by SEM after resin removal. Furthermore, the ultrathin sections adjacent to the semithin sections were observed by TEM. The three-dimensional images of intracellular organelles provided an informative adjunct to LM and TEM.

Animals↗

PubMed1990

Influence of pH adjustment agents on the biologic behavior of osmium-191 impurity in iridium-191m generator eluates.

The influence of four pH adjustment agents on the biologic behavior of osmium-191 (191Os) impurity in 191Os/191mIr generator eluates was studied. Extended body clearance and biodistribution studies were performed in mice. The solutions to be injected were obtained by eluting generators with a 0.9% NaCl solution at pH 1. The pH of these eluates was adjusted to 5-9 with succinate, phosphate, lysine or NaOH solution. Our results demonstrate that the biologic behavior of these generator eluates is significantly dependent on the agent used for pH adjustment. Buffering with lysine leads to the best results: (a) the mice show no adverse reaction after injection of 150 human doses and the body clearance is very rapid and (b) more than 75% I.D. at 24 hr postinjection. Preliminary calculations based on these results suggest a significant decrease in the estimated patient radiation dose when lysine buffered 191Os/191mIr generator eluates are used for radionuclide angiography.

Animals↗

PubMed1987

An osmium-191/iridium-191m radionuclide generator using an oxalato osmate parent complex.

A new osmium-191/iridium-191m (191Os/191mIr) radionuclide generator has been developed that offers high 191mIr yield (greater than 20%/ml) and low 191Os breakthrough (less than 5 X 10(-4)%/ml) when eluted with a solution of 0.001 M oxalic acid and 0.9% (normal) saline. This is the first 191Os/191mIr generator that combines the advantages of high 191mIr yield, extremely low 191Os breakthrough, and an eluate that does not require buffering prior to injection. These improvements in performance were accomplished through use of the chelate transdioxobisoxalatoosmate(VI) as the parent complex on the generator. The clinical result of the combination of higher yield and lower breakthrough is a 100-fold decrease in the estimated patient radiation dose compared with the same study performed with technetium-99m (99mTc), and the injectable eluate makes the generator easier to use. Acute and subacute toxicity studies performed on this generator eluate have shown no adverse effects attributable to the eluate.

Iridium↗

PubMed1986

A new osmium-191/iridium-191m radionuclide generator system using activated carbon.

A new osmium-191/iridium-191m (191Os/191mIr) radionuclide generator system has been developed based on the absorption of K2OsCl6 (Os-IV) on 140-230 mesh heat-treated activated carbon. The generator is eluted with pH 2 saline solution containing 0.25 g/l Kl to give 191mIr in good yield. The generator eluent is neutralized to physiologic pH and isotonicity with Tris buffer immediately prior to i.v. injection. No scavenger column is required. As an example, elution of the prototype generator with a 2-ml bolus results in elution of 191mIr in approximately 18% yield with an 191Os breakthrough of only 2 X 10(-4)%/bolus. The prototype generator has consistent performance over a 2-wk period with no change in 191mIr yield or 191Os breakthrough. Loading of up to 1.5 Ci of 191Os results in no observed radiolysis. Continuous elution of this system is also possible with a mean 191mIr yield of 3.7%/ml and a mean 191Os breakthrough of 2 X 10(-5)%/ml at a flow rate of 12 ml/min. This new system represents a readily available source of 191mIr for radioangiography. Adsorbed radiation dose calculations indicate a total-body dose of only 3.9 mrad for a 100 mCi injected bolus.

Adsorption↗

PubMed1966

Release of carbohydrates from sphingoglycolipid by osmium-catalyzed periodate oxidation followed by treatment with mild alkali.

The carbohydrate moiety of sphingoglycolipid, after preliminary acetylation, can be released by periodate oxidation catalyzed by a trace amount of osmium tetroxide, followed by alkaline treatment. Cerebroside, lactosyl ceramide, hematoside, globoside, and gangliosides were degraded to yield, respectively, galactose, lactose, sialyl lactose, a tetrasaccharide, and various oligosaccharides containing sialic acid. Oligosaccharides were separated by paper chromatography and paper electrophoresis. The procedure is useful for characterizing micromolar amounts of sphingoglycolipids.

Alkalies↗

PubMed1975

[Zinc-iodine-osmium impregnation of giant synaptosomes obtained from the hippocampal formation of the rabbit].

The fraction of giant synaptosomes from the r. inferior of the rabbit hippocampus was studied using impregnation with zinc iodide-osmium tetroxide (XIO) reagent and electron microscopy. In this fraction, light and dark synaptosomes were observed. The reaction product was found in the clear-centered synaptic vesicles (200-400 A) as electron-dense structures of different forms and small osmiophilic particles on the vesicular membranes. Dense-cored vesicles and postsynaptic structures were not revealed with ZIO-reagent. The structures revealed with ZIO-reagent in the giant synaptosomes of the hippocampus are supposedly related to stroage of the neurotransmitter-glutamate.

Animals↗

PubMed1982

Double staining by vaporized osmium tetroxide-hydrazine hydrate of biological specimens for non-coated scanning electron microscopy.

Sufficient electron conductivity was obtained in biological specimens following double staining with vaporized osmium tetroxide and hydrazine hydrate for non-gold coated scanning electron microscopic observations. No charging was noted at 25 kV acceleration voltage in rat kidney, liver or other specimens. The foot processes of the glomerular podocytes and micropores of the glomerular endothelium as well as the intracellular endoplasmic reticulum of liver cells were particularly well visualized without the addition of evaporated metal. Repeating this vapor phase osmication method produced even higher contrast at high magnifications compared to the single vaporized osmication method.

Animals↗

PubMed1983

Conductive staining of biological specimens for scanning electron microscopy with special reference to ligand-mediated osmium impregnation.

Biological specimens for scanning electron microscopy are made electron-conductive and non-charging by intense osmication with tannic acid, thiocarbohydrazide, hydrazine hydrate or other bifunctional ligands (or mordants). Such osmication also minimizes tissue shrinkage during dehydration and drying, reduces tissue damage during metal coating and scanning observations, and circumvents the use of a thick metal coating which hinders high resolution. Intense osmication when repeated eliminates the need for a metal coating and produces a well-contrasted scanning image with good resolution. Moreover, such osmication reduces tissue damage during ion implanting, enhances the depth of imaging, allows x-ray microanalysis without coated metals, and permits resin-embedded observations, as well as continuous or repeated microdissections in the scanning electron microscope without charging. Intense osmication forms a surface coat or thickens the cell membrane. This surface coat consists of electron dense deposits of 4-20 nm thickness. The hydrazine hydrate-osmium method can be used in the vapor phase. The vapor phase application has the advantage of staining even plastic samples for non-metal-coated scanning electron microscopy.

Animals↗

PubMed1980

A new osmium-191 leads to iridium-191m generator.

A new osmium-191 leads to iridium-191m generator suitable for first-pass radionuclide angiocardiography has been developed. This generator system allows repeated elutions of 4.96-sec iridium-191m from its 15.4-day Os- 191 parent. The Os-191 is loaded on an anion-exchange column (AGMP-1) and Ir- 191m eluted with 0.9% NaCl at pH 1. Each elution (0.6 to 1 ml) of the generator yields about 7 to 10% Ir-191m and gives 0.003-0.008% of Os-191 breakthrough. Toxicity studies of the generator eluate carried out in animals support the safety of using iridium-191m in humans. The long shelf-life of the generator (approximately equal to 2 wk) will allow medical centers to use Ir- 191m for routine clinical diagnosis. Iridium-191m obtained by this method should find additional useful applications in nuclear medicine.

Animals↗

PubMed1994

New applications for the zinc iodide-osmium tetroxide technique.

The zinc iodide-osmium tetroxide (ZIO) fixation/staining method was applied for neurocytological studies and also to examine several other tissue samples including epidermal Langerhans cells, blood and bone marrow cells and lymphoid tissue. Although precise specificity cannot be attributed to the staining reaction, interesting staining patterns for different cell types were observed by using one of the ZIO staining solutions. The significance of ZIO positivity is briefly discussed.

Animals↗

PubMedDate not supplied

Specificity of the zinc-iodide-osmium (ZIO) reagent in the nervous tissue: evaluation of the Ca++ binding sites hypothesis.

We tested the Ca(2+) binding sites detection hypothesis of the zinc-iodide-osmium (ZIO) staining on synaptic vesicles of rat cerebellar glomerulus using three different approaches based on the previous observation that Ca(2+) chelator EGTA can impede the staining reaction: (a) ZIO staining of "en bloc" tissue samples after EGTA exposure, (b) staining of ultrathin sections with ZIO reagent after EGTA treatment, (c) ZIO staining of isolated synaptic vesicles, preincubated in calcium ionophore A23187. The results of our investigation do not support the hypothesis. We conclude that ZIO staining can be referred to different molecules located mainly in secretory organelles.

Animals↗