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Inhalation Toxicity of Metal Particles and Vapors
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Osmium, the most dense metal, is used in metal alloys with iridium in instrument pivots, compass needles, electrical contacts, and engraving tools. Until 1969, two osmium alloys were used as fountain pen tips. Academic and research laboratories are the major users of osmium. Osmium tetroxide is used as a tissue stain for histological preparations.
Immunohistochemistry of the Pulmonary Extracellular Matrix
Published in Joan Gil, Models of Lung Disease, 2020
Antonio Martinez-Hernandez, Peter S. Amenta
The DAB deposited in the tissues lacks electron density; however, it is highly osmiophilic. Therefore, incubation with OsO4 results in DAB-OsO4 complexes suitable for electron microscopy. Following DAB incubation and a PBS wash, the sections are reacted with 1% osmium tetroxide in 0.1 M sodium phosphate buffer with 0.026 M NaCl, at pH 7.2, for 1 hr at room temperature. Osmium tetroxide vapors are toxic, particularly to corneal tissues: care should be taken to work under a chemical hood. An ampule of osmium tetroxide (1 g/vial) is broken inside a tightly stoppered brown glass bottle and dissolved in 50 ml of distilled water (2%). Complete solubilization may take 24 hr, but it may be accelerated by placing the tightly stoppered bottle in a sonicator bath. This 2% aqueous OsO4 solution is diluted 1:1 with 0.2 M sodium phosphate buffer containing 0.026 NaCl (pH 7.2) immediately before use.
Tissue Preparation For Autoradiography the Autoradiographic Process
Published in Lelio G. Colombetti, Principles of Radiopharmacology, 2019
Alicia S. Ugarte, Lelio G. Colombetti, Dieudonne J. Mewissen
Specimen fixation — As soon as the tissues are removed from the experimental animal, they are fixed in a buffered solution of osmium tetroxide or formaldehyde. Gran-boulan used a 1 to 1 mixture of 10% formaldehyde and a buffered 10% solution of acrolein.19 Avoid inhaling the irritant osmium tetroxide vapors and protect the eyes with goggles.
Mechanistic study of copper oxide, zinc oxide, cadmium oxide, and silver nanoparticles-mediated toxicity on the probiotic Lactobacillus reuteri
Published in Drug and Chemical Toxicology, 2023
Aya M. Eid, Osama M. Sayed, Walaa Hozayen, Tarek Dishisha
L. reuteri was treated with sub-MICs and MICs of CuO-, ZnO-, CdO-, and Ag-NPs separately for 24 h, then prepared for conventional TEM imaging using the following protocol (Hackenberg et al.2011). Bacterial cells were centrifuged at 6000 rpm for 2 min, then rinsed in sterile PBS and the supernatant discarded. Subsequently, prefixation of the bacterial samples was performed in 2.5% glutaraldehyde for 1 h, and then washed with sodium cacodylate buffer. Samples were dyed with 1% osmium tetraoxide for 2 h. A series of ethanol solutions ranging from 50% to 100% were used to dehydrate the cells. Following that, each sample was embedded in epoxy resin EPON 810 with DMP and polymerized for 48 h at 60 °C for 48 h. Fixed samples were sliced in a Leica ultra-microtome with 70 nm average thickness and stained with lead citrate and uranyl acetate. Samples were then placed on copper grids and analyzed by a JEOL JEM-1400 TEM (JEOL Inc., Japan) at 80 kV. Untreated L. reuteri was used as a control.
Targeting the PANoptosome with 3,4-Methylenedioxy-β-Nitrostyrene, Reduces PANoptosis and Protects the Kidney against Renal İschemia-Reperfusion Injury
Published in Journal of Investigative Surgery, 2022
Erdal Uysal, Mehmet Dokur, Faruk Kucukdurmaz, Serdar Altınay, Sait Polat, Kadir Batcıoglu, Efe Sezgın, Tuğçe Sapmaz Erçakallı, Aslı Yaylalı, Yakup Yılmaztekin, Zafer Cetın, İlker Saygılı, Osman Barut, Hatem Kazımoglu, Gokturk Maralcan, Suna Koc, Turkan Guney, Nadire Eser, Mehmet Sökücü, Sema Nur Dokur
The renal tissue samples were fixed in a five percent glutaraldehyde solution produced with Millonig’s phosphate buffer for three hours prior to electron microscopic examination. After shaking two times in the buffer for ten minutes, the samples were fixed in a 1 percent osmium tetraoxide solution prepared with Millonig’s phosphate buffer. After 2 hours of osmium tetraoxide fixing, the tissues were washed twice with phosphate buffer for ten minutes each time. After that, the tissues were sequentially dehydrated in 50 percent, 70 percent, 86 percent, 96 percent, and 100 percent of ethyl alcohol (each for 15 minutes). Following that, the tissues were treated with propylene oxide twice for fifteen minutes each time, followed by propylene oxide + resin for thirty minutes each time (twice). The renal tissue pieces were then placed in tubes containing newly prepared embedding material (resin) and swirled for 6 hours in a mixer. The kidney tissue sections were first placed in Beem® tablets the next day using newly manufactured embedding substance, and the material was then polymerized for two days in a 60 °C drying oven. The ultrathin slices (50 nm in thickness) were then cut using a Leica Reichert Ultracut S ultramicrotome (Austria). Saturated uranyl acetate produced in 70% ethyl alcohol and lead citrate solutions were used to stain the sections. Using a Transmission Electron Microscopy (TEM, Japan), the stained slices were examined and micrographed.
Dose and time response study to develop retinal degenerative model of zebrafish with lead acetate
Published in Cutaneous and Ocular Toxicology, 2022
The eye were enucleated and fixed in 5% glutraldehyde at 4˚C overnight. Next day retina was isolated and washed with 0.1 M Sorenson’s buffer. Post fixation was done with 1% osmium tetraoxide at 4 °C for 1 h. The tissue was subjected to dehydration with ascending series of acetone upto 100% concentration at 4 °C. This retinal tissue was further treated with different ratios of acetone and amyl acetate (Acetone:Amyl acetate- 3:1, 1:1, 1:3) at 4 °C. Finally, tissue was dried using CPD (Critical Point Dryer). Dried sample were loaded on metallic specimen stubs and specimens were coated with platinum ion using sputter coater (Hitachi MC1000). The conducted specimen was examined under Field Emission Scanning Electron Microscope (Hitachi SU1080, Japan) at CIL, Panjab University, Chandigarh.