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Peter Lindblad - One of the best experts on this subject based on the ideXlab platform.
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Expression of alkaline phosphatase in the mature mouse placenta visualized by in situ hybridization and Enzyme Histochemistry
Anatomy and Embryology, 1993Co-Authors: Sophie Johansson, Mariann Wide, Erica Young, Peter LindbladAbstract:Alkaline phosphatases (APs) are a family of cell surface glycoproteins that are expressed in a variety of tissues. Their physiologcial functions are still unclear. Three different AP genes have been found to be expressed in mice, and AP cloned from the placenta is of the tissue non-specific (TNAP) type. We have in investigated the location of TNAP mRNA and active AP in mature mouse placenta, using in situ hybridization and Enzyme Histochemistry on serial sections. Digital image analysis was used to estimate relative amounts of TNAP mRNA. Tissue non-specific alkaline phosphatase messenger was detected only in the placental labyrinth, whereas active AP was present both in the labyrinth and in a zone of cells at the margin of the decidua basalis, bordering the myometrium and the metrial gland. This latter location of AP activity has not been described previously. The AP-positive zone of the decidua had a condensed appearance and a central defect in the zone was visible on sections taken from the middle of the placenta. No TNAP messenger was found in the zone of AP-positive decidual cells.
Graeme I. Murray - One of the best experts on this subject based on the ideXlab platform.
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Enzyme Histochemistry and immunoHistochemistry with freeze-dried or freeze-substituted resin-embedded tissue
The Histochemical Journal, 1992Co-Authors: Graeme I. MurrayAbstract:Freeze-drying or freeze-substitution, combined with low-temperature resin-embedding, represents a new approach to the optimum preservation of tissue for Enzyme Histochemistry and immunoHistochemistry. This method, which avoids tissue fixation, combines excellent tissue morphology with the preservation of Enzyme activity and immunoreactivity and allows high-resolution Enzyme histochemical and immunohistochemical studies to be performed. The activity of a wide range of Enzymes can be demonstrated in sections of freeze-dried or freeze-substituted resin-embedded tissue. Enzymes are retained in situ with high activity, accurate localization and no diffusion. Immunohistochemical studies can also be performed on resin sections, and antigens—especially labile antigens — are immobilized in situ without denaturation and can be demonstrated with high sensitivity and accurately localized. This method allows the localization and distribution of Enzymes and antigens to be studied in relation to excellent histological and cytological detail.
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Enzyme Histochemistry and immunoHistochemistry with freeze-dried or freeze-substituted resin-embedded tissue
The Histochemical Journal, 1992Co-Authors: Graeme I. MurrayAbstract:Freeze-drying or freeze-substitution, combined with low-temperature resin-embedding, represents a new approach to the optimum preservation of tissue for Enzyme Histochemistry and immunoHistochemistry. This method, which avoids tissue fixation, combines excellent tissue morphology with the preservation of Enzyme activity and immunoreactivity and allows high-resolution Enzyme histochemical and immunohistochemical studies to be performed. The activity of a wide range of Enzymes can be demonstrated in sections of freeze-dried or freeze-substituted resin-embedded tissue. Enzymes are retained in situ with high activity, accurate localization and no diffusion. Immunohistochemical studies can also be performed on resin sections, and antigens—especially labile antigens — are immobilized in situ without denaturation and can be demonstrated with high sensitivity and accurately localized. This method allows the localization and distribution of Enzymes and antigens to be studied in relation to excellent histological and cytological detail.
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Enzyme Histochemistry on freeze substituted glycol methacrylate embedded tissue
Journal of Histochemistry and Cytochemistry, 1990Co-Authors: Graeme I. Murray, Stanley W B EwenAbstract:We developed a method for histochemical demonstration of a wide range of Enzymes in freeze-substituted glycol methacrylate-embedded tissue. Tissue specimens were freeze-substituted in acetone and then embedded at low temperature in glycol methacrylate resin. All Enzymes studied (oxidoreductases, hydrolases) were readily demonstrated. The Enzymes displayed high activity and were accurately localized without diffusion when tissue sections were incubated in aqueous media, addition of colloid stabilizers to the incubating media not being required. Freeze-substitution combined with low-temperature glycol methacrylate embedding permits the demonstration of a wide range of Enzymes with accurate Enzyme localization, maintenance of Enzyme activity, and excellent tissue morphology.
Sophie Johansson - One of the best experts on this subject based on the ideXlab platform.
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Expression of alkaline phosphatase in the mature mouse placenta visualized by in situ hybridization and Enzyme Histochemistry
Anatomy and Embryology, 1993Co-Authors: Sophie Johansson, Mariann Wide, Erica Young, Peter LindbladAbstract:Alkaline phosphatases (APs) are a family of cell surface glycoproteins that are expressed in a variety of tissues. Their physiologcial functions are still unclear. Three different AP genes have been found to be expressed in mice, and AP cloned from the placenta is of the tissue non-specific (TNAP) type. We have in investigated the location of TNAP mRNA and active AP in mature mouse placenta, using in situ hybridization and Enzyme Histochemistry on serial sections. Digital image analysis was used to estimate relative amounts of TNAP mRNA. Tissue non-specific alkaline phosphatase messenger was detected only in the placental labyrinth, whereas active AP was present both in the labyrinth and in a zone of cells at the margin of the decidua basalis, bordering the myometrium and the metrial gland. This latter location of AP activity has not been described previously. The AP-positive zone of the decidua had a condensed appearance and a central defect in the zone was visible on sections taken from the middle of the placenta. No TNAP messenger was found in the zone of AP-positive decidual cells.
Kamen P. Valchanov - One of the best experts on this subject based on the ideXlab platform.
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Enzyme Histochemistry of tryptase in stomach mucosal mast cells of the mouse
Journal of Histochemistry and Cytochemistry, 1999Co-Authors: Kamen P. Valchanov, Gordon ProctorAbstract:We investigated the histochemical characteristics of mast cell tryptase in different mouse tissues. By use of peptide substrates, tryptase activity could be demonstrated in unfixed connective tissue mast cells in different tissues, including the stomach. Tryptase activity was better localized after aldehyde fixation and frozen sectioning, and under such conditions was also demonstrated in mucosal mast cells of the stomach but not in those of the gut mucosa. Double staining by Enzyme Histochemistry followed by toluidine blue indicated that the tryptase activity was present only in mast cells and that all mast cells in the stomach mucosa contained the Enzyme. The peptide substrates z-Ala-Ala-Lys-4-methoxy-2-naphthylamide and z-Gly-Pro-Arg-4-methoxy-2-naphthlyamide, which are substrates of choice for demonstrating tryptase in other species, were most effective for demonstrating mouse tryptase. The use of protease inhibitors further indicated that activity present in all mast cells was tryptase. Safranin O did not stain stomach mucosal mast cells, suggesting that the tryptase present in these cells was active in the absence of heparin sulfate proteoglycan.
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Enzyme Histochemistry of rat mast cell tryptase
The Histochemical Journal, 1998Co-Authors: Kamen P. Valchanov, Gordon B. Proctor, Robert H. Hartley, Katherine L. Paterson, Deepak K. ShoriAbstract:Fixation and staining conditions for rat mast cell tryptase and its histochemical distribution in different rat tissues were investigated. Prostate, skin, lung, gut, stomach and salivary glands were fixed in either aldehyde or Carnoy fixatives and then frozen or embedded in paraffin wax. Preservation of tryptase enzymic activity against peptide substrates required aldehyde fixation and frozen sectioning. Of the peptide substrates examined, z-Ala-Ala-Lys-4-methoxy-2-naphthylamide and z-Gly-Pro-Arg-4-methoxy-2-naphthylamide proved the most effective for the demonstration of tryptase. Double staining by Enzyme cytochemistry followed by immunological detection of tryptase showed that, in all tryptase-containing mast cells, the Enzyme is at least in part active. Conventional dye-binding Histochemistry was used to confirm the identity of mast cells. Aldehyde-fixed mucosal mast cells required a much shorter staining time with Toluidine Blue if tissue sections were washed directly in t-butyl alcohol. Double staining by Enzyme cytochemistry and dye binding showed that tryptase is absent from mucosal and subepidermal mast cells, which are also smaller in size and appear to contain fewer granules than connective tissue mast cells. This study demonstrates that rat mast cell tryptase, unlike tryptases in other species, is a soluble Enzyme. It is stored in an active form and is absent from some mast cell subpopulations in mucosa, skin and lung. © 1998 Chapman & Hall
Ikuo Sato - One of the best experts on this subject based on the ideXlab platform.
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Enzyme Histochemistry on human placental trophoblasts the effect of fixation delay on Enzyme activity
Histochemistry and Cell Biology, 2000Co-Authors: Shigeki Matsubara, Toshihiro Takizawa, Ikuo SatoAbstract:We examined the effect of time delay in tissue fixation on Enzyme histochemically detectable Enzyme activity and its localization in term human placental trophoblasts. Four placental Enzymes, alkaline phosphatase, acid phosphatase, glucose-6-phosphatase, and cytochrome c oxidase, were studied. A fixation delay of 15 min did not markedly alter the activity or distribution pattern of the four Enzymes, excepted for a slight reduction in cytochrome c oxidase activity and the appearance of dilated endoplasmic reticula positive for glucose-6-phosphatase. A fixation delay of 60 min abolished cytochrome c oxidase activity, but the activities of the other three Enzymes remained positive. When the placental tissue was stored at 4°C without cutting for 24 h before fixation, cell degeneration occurred. However, alkaline phosphatase activity was still clearly demonstrable. In Enzyme Histochemistry, "immediate" fixation is superior, but even if this cannot be performed, the placentas, especially when they are from patients with rare disorders, should not be discarded. Observations made here will be useful for clinician's attempting Enzyme Histochemistry in organs other than the placenta.