Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proteolytic enzymes, protease and trypsin have recently been introduced to reduce the inconsistency hitherto encountered in the unlabelled antibody--enzyme method using PAP. This study investigated factors determining the optimum conditions for use of such enzymes in order to establish which one is most suitable. Trypsin was the most effective enzyme; however, its activity decreased over 3 h, a feature paralleled immunocytochemically. Method and duration of fixation appears to influence the required time of exposure to trypsin in order that consistent immunostaining may be produced. Treatment of sections with trypsin prior to the use of the unlabelled antibody--enzyme method using PAP renders the technique reliable, provided the enzyme is used in a carefully controlled manner.
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PMID:The use of proteolytic enzymes to improve immunoglobulin staining by the PAP technique. 37 7

Proteolytic enzymes were tested for improving histochemical localization of tissue antigens. Sections, 2-4 micron in thickness, were prepared on sodium-silicate coated slides from formalin-fixed, paraffin-embedded human biopsies. A modification of the Sternberger technique (PAP) and the indirect immunofluorescence method were used for the localization of 15 various antigens: heavy chain immunoglobulins, light chain immunoglobulins, alpha 1-fetoprotein, alpha 1-antichymotrypsin, myoglobin, fibronectin, factor VIII (ass. ag), fibrinogen, lysozyme and cytokeratin. The ability of different proteolytic enzymes (trypsin, pronase, pepsin) to unmask antigen in formalin-fixed sections were tested by variation of concentration, incubation time, temperature and pH. Although proteolytic unmasking to some extent is reliable, good restoration of antigenicity is not always possible. Best results were obtained with pronase E (Serva, FRG).
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PMID:[The proteolytic pretreatment of formalin-fixed tissue in immunohistochemical diagnosis]. 245 12

Benign and malignant fibrous histiocytomas are composed of an admixture of fibroblast-like and histiocyte-like cells and of a changing amount of fibre structures which tend to be arranged in a so-called storiform pattern. In order to study the organization of the extracellular matrix, the distribution of fibronectin was investigated immunohistochemically. Using the PAP technique and the indirect immunofluorescence method, paraffin sections of formaldehyde fixed tissue specimens of 25 tumours (12 benign fibrous histiocytomas, 12 malignant fibrous histiocytomas, and 1 atypical fibroxanthoma) were studied. A pretreatment with hyaluronidase and proteolytic enzymes (trypsin, pronase, pepsin) was performed to unmask the antigen. Best results were obtained with pronase E or, sometimes even better, by employing a combination of pronase E and hyaluronidase. Generally fibronectin could be demonstrated in the matrix substances of fibrohistiocytic tumours, but the immunohistochemical staining patterns of benign and malignant tumours differed. In benign fibrous histiocytomas, a regular distribution of fibronectin was found in cellular areas. Parallel to formation of collagen fibres, the reaction decreased and in dermatofibromas showing abundant hyalinized collagen the staining proved to be quite weak. In malignant fibrous histiocytomas, the immunostaining was very irregular. In cellular areas consisting of spindle cells, an intense reaction could be observed. Tumours with storiform or fascicular fields exhibit a delicate network of fibronectin encircling individual fibroblast-like cells. In the course of fibre formation, the matrix staining for fibronectin revealed a distribution similar but not identical with that obtained with the reticulin stain. Simultaneous to the occurrence of collagen fibre bundles, fibronectin decreased and in areas of hyalinization the staining was considerably diminished. In areas of undifferentiated small cells, in myxoid zones as well as foci of xanthoma cells, and in pleomorphic portions the immunostain was negative. The distribution in atypical fibroxanthoma is similar to that observed in storiform and pleomorphic variants of malignant fibrous histiocytomas. The results support the suggestion that fibronectin is the first sign of the typical basic pattern of fibrohistiocytic tumours preceding the formation of reticulin and collagen fibres. The expression of fibronectin on cell surfaces as well as in intercellular matrix may be closely related to the organization of the growth patterns of fibrohistiocytic tumours.
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PMID:Fibronectin in relation to growth patterns of fibrohistiocytic tumours--an immunohistochemical study of benign and malignant fibrous histiocytomas. 282 24

Human placental microsomal aminopeptidase (microsomal PAP) was purified 3,880-fold from human placenta and characterized. The enzyme was solubilized from membrane fractions with Triton X-100 and also trypsin digestion, and subjected to zinc sulfate fractionation, chromatographies with DE-52, hydroxylapatite, Sephacryl S-300 and lentil lectin-Sepharose 4B, and finally affinity chromatography with bestatin-Sepharose 4B. Microsomal PAP was separated from aminopeptidase A (AAP) by affinity chromatography. The apparent relative molecular mass (Mr) of the enzyme was estimated to be 220,000 by high-performance liquid chromatography with an aqueous gel column. The purified enzyme gave almost a single band with a molecular mass of 140,000 by sodium dodecyl sulfate (SDS) gel electrophoresis. The isoelectric point of the enzyme was 5.2. The purified enzyme was most active at pH 8.0 with L-leucine-p-nitroanilide as substrate; the Km value for this substrate was 1.1 mmol/l. The microsomal PAP was immunologically different from the pregnancy serum cystyl aminopeptidase (serum PAP).
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PMID:Purification and characterization of human placental microsomal aminopeptidase: immunological difference between placental microsomal aminopeptidase and pregnancy serum cystyl-aminopeptidase. 287 70

The effect of trypsin digestion on the immunoperoxidase-PAP staining of paraffin sections from normal and abnormal tissue was studied. Trypsin treatment reduced background staining considerably, but enhanced specific staining. Results were, therefore, much easier to read. Possible reasons for this result are discussed.
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PMID:Trypsin digestion in immunoperoxidase staining. 615 93

Intermediate-sized filaments have been noted in epithelioid sarcoma by previous investigators, two of whom have reported that the filaments represent vimentin. We utilized polyclonal antibodies directed against keratin and immunoperoxidase techniques (PAP) to stain 32 of the more than 300 cases accumulated at the AFIP . All of our material was formalin-fixed, paraffin-embedded. Seventy-five percent of our cases (24/32) showed positive immunoreactivity, a feature that may be of diagnostic help in distinguishing epithelioid sarcoma from modular fasciitis, benign and malignant fibrous histiocytoma, malignant melanoma, and necrotizing granuloma. In these cases, the reaction was enhanced using predigestion with trypsin. The immunoreactivity varied from tumor to tumor, perhaps due to formalin fixation. Since synovial sarcoma and mesothelioma may also be cytokeratin-positive, our findings indicate that keratin immunoreactivity is not confined to epithelial tumors and may also occur in neoplasms traditionally regarded as mesenchymal.
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PMID:Keratin in epithelioid sarcoma. An immunohistochemical study. 620 17

Different immunohistological methods were compared in 30 renal biopsy cases. The direct immunoperoxidase method gave identical results with immunofluorescence in 88% concerning IgG and C3, while IgA, IgM and fibrinogen have been identically detected by the PAP method in 82%. The non-identical results of the direct method consisted, with one exception, of negative readings, while the non-identical PAP readings were positive with two exceptions. Thus the trypsin-immunoperoxidase method proved to be well applicable on paraffin embedded formalin fixed material. In 10 cases the HRP-labelled direct method was applied also to fresh, frozen sections. It gave almost entirely identical results to immunofluorescence.
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PMID:Application of the immunoperoxidase technique to formalin fixed, paraffin embedded kidney biopsies. 635 3

There is continuing controversy over the role of mononuclear phagocytes in glomerulonephritis. It is, therefore, important to know their distribution in normal subjects. Normal kidneys (34) were assessed using three cytoplasmic markers for macrophages employing a trypsin-immunoperoxidase (PAP) technique with antibodies to alpha-1-antitrypsin, muramidase (lysozyme) and a further oligoclonal antibody, serum 22, developed against highly purified preparations of blood monocytes. Serum 22 detected twice as many monocytes/macrophages as anti-muramidase and four times as many as anti-alpha-1-antitrypsin. Most cells that showed positive staining lay in glomerular and intertubular capillaries and were considered to be blood monocytes. There was wide variation in monocyte numbers throughout different glomeruli and up to 14 monocytes could be present in a glomerulus. Not more than 1 per cent lay within the mesangium. Macrophages were virtually never seen in the interstitium, except in areas of scarring. No macrophages were present in the tubules. Monocytes and macrophages are demonstrated in greater numbers within the kidney by antisera to muramidase than to alpha-1-antitrypsin.
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PMID:The monocyte/macrophage population of the normal human kidney. 638 48

Rat peritoneal macrophages were incubated at 4 degrees C in media of varying pH-s containing rat peroxidase-antiperoxidase /PAP/ immune complex. Two binding maxima were found at pH 5.5 and 7.0, resp. There was a sharp decrease in binding between 5.5 and 5.0. The peak at pH 7.0 was found to be trypsin-sensitive.
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PMID:pH-dependent binding of peroxidase-antiperoxidase /PAP/ immune complex to Fc receptors of macrophages. 639 52

The aim of this research is to show the alterations of alpha-actinin in rabbit myocardium after DMF treatment administered by forced inhalation. Z-lines observed with light and phase-contrast microscopy, appeared to be intact and they were clearly displayed by the indirect PAP-reaction. But if you consider that in normal muscle Z lines do not get coloured by the PAP-reaction without a previous light treatment with trypsin. It may be inferred that, in this case, The DMF has had the same effect as the trypsin, causing alteration to the protein structure. Besides the sarcomeric structure is undoubtedly altered by the DMF, causing alterations, in our opinion, similar to those found in rabbit skeletal muscle, under conditions of acute experimental ischemia.
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PMID:[Structural and ultrastructural changes in the rabbit myocardium exposed to dimethylformamide vapors]. 676 21


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