Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied glycogen storage in the developing airway epithelium of Syrian golden hamsters from gestational Day 11 to neonatal Day 2 using concanavalin A (ConA) staining as an adjunct approach to the periodic acid-Schiff (PAS) reaction. One hundred and fourteen fetuses and neonates were fixed in 4% formaldehyde-1% glutaraldehyde, 6% mercuric chloride-1% sodium acetate-0.1% glutaraldehyde, and 95% ethanol, embedded in paraffin, and stained with ConA-horseradish peroxidase conjugate as well as with PAS. ConA staining was abolished by alpha-glucosidase digestion or by pre-treatment with periodic acid, demonstrating that ConA bound to glycogen. In tissues fixed with mercury and/or aldehydes, ConA staining was greatly enhanced by pepsin digestion. Airway glycogen stores, revealed by ConA and PAS, fluctuated during development. At first all the undifferentiated epithelial cells contained abundant glycogen. Then, coincident with the appearance of the first endocrine cells, the glycogen stores were depleted. Thereafter, glycogen accumulated in pre-secretory and basal cells until birth, but by 2 days after birth the glycogen stores were again depleted. The initial depletion of glycogen followed by repletion was observed at all levels of the conducting airways; changes in the trachea preceded those in the bronchi and bronchioles by 1 and 2 days, respectively.
 ...
PMID:Modulation of glycogen stores in epithelial cells during airway development in Syrian golden hamsters: a histochemical study comparing concanavalin A binding with the periodic acid-Schiff reaction. 233 26

1. Chemical oxidation of N,N-dimethyl-p-anisidine (DMA) with bromine at pH 5-8 gave p-N,N-dimethylaminophenoxy radical irrespective of the DMA/Br2 ratio (1 to 100), whereas the ethyl hydroperoxide-supported oxidation of DMA catalysed by lactoperoxidase gave the phenoxy radical or the cation radical of DMA depending upon the concentration of DMA. 2. The amount of p-benzoquinone produced by the chemical oxidation increased steeply with an increase in pH above 6.0, whereas that produced by the lactoperoxidase-ethyl hydroperoxide-bromide system exhibited a pH optimum centred around pH 6.0. When the concentration of DMA was increased 10-fold, the enzymic formation of p-benzoquinone greatly decreased, whereas that of formaldehyde increased. 3. The rate of formation of the oxidized bromine species by the lactoperoxidase-ethyl hydroperoxide-bromide system showed a similar pH-profile to the formation of p-benzoquinone. 4. The oxidized bromine species is considered to be the predominant oxidizing agent in the lactoperoxidase-ethyl hydroperoxide-bromide system at pH 6.0 and below. The decrease in the amount of p-benzoquinone formed, and the increase in the amount of formaldehyde formed, by the lactoperoxidase-ethyl hydroperoxide-bromide system with increasing concentration of DMA, were interpreted in terms of competition between bromide and DMA for the reaction with compound I of lactoperoxidase.
 ...
PMID:Ethyl hydroperoxide-dependent metabolism of N,N-dimethyl-p-anisidine catalysed by lactoperoxidase. 233 36

The distribution of astrocytes was studied in the hippocampus of mature Wistar rats. Immunohistochemistry was performed using antibodies against glial fibrillary acidic protein (GFAP), vimentin and S-100 protein and peroxidase anti-peroxidase techniques. Material from fresh-frozen brain, post-fixed in acetone, yielded a complex picture of the glial populations when stained for GFAP. Astrocytes immunoreactive for GFAP were seen in white matter tracts but also in the large dendritic layers of the hippocampus. Frozen material also contained different types of astrocytes following staining with a monoclonal antibody to vimentin. Stellate astrocyte types in the dendritic layers contained vimentin-stained processes. In addition a form of residual radial glia was found in the dentate gyrus. Material from brains perfusion-fixed with formaldehyde remained positive for astrocytic GFAP, but was negative for vimentin. Staining for S-100 protein antibodies revealed numerous astrocytes and diffuse background staining in fixed material. This study allows one to make predictions concerning the use of astrocytic markers in experimental pathological material.
 ...
PMID:Immunohistochemistry of glial fibrillary acidic protein, vimentin and S-100 protein for study of astrocytes in hippocampus of rat. 236 51

In this study, 39 primary, surgically resected, pulmonary adenocarcinomas of the following cell types were investigated: 19 Clara cell, 4 bronchial-gland, 15 goblet cell, and 1 type II alveolar epithelial adenocarcinoma. They were analyzed for the expression of the glandular differentiation-associated antigen recognized by the monoclonal antibody 44-3A6. Formalin-fixed, paraffin-embedded tissue sections were immunostained using the avidinbiotin complex/peroxidase method. All of the Clara cell tumors (19/19) expressed this antigen as well as 3/4 bronchial-gland tumors, as compared to only 2/15 goblet cell tumors. The single type II pneumocyte neoplasm studied was found to express this antigen. These findings parallel our earlier observations based on cytological features, and provide supportive evidence that there may be biological differences between human pulmonary adenocarcinomas and bronchioloalveolar carcinomas.
 ...
PMID:Immunohistochemical analysis of human adenocarcinomas of the lung using the monoclonal antibody 44-3A6. 237 95

The presence and distribution of cytokeratins (CK) have been investigated using an epidermal keratin antiserum in various dilutions and the PaP (peroxidase-antiperoxidase) and avidin-biotin-peroxidase (ABC) immunohistochemical methods. A total of 44 samples of prostatic tissue were divided into alcohol-fixed (22 cases) and formaldehyde-fixed (22 cases). Each group included 12 non-malignant lesions (hyperplasias and prostatitis) and 10 adenocarcinomas. The best results were achieved with the ABC method in alcohol-fixed tissues, while formaldehyde-fixed tissues gave poor staining despite the use of different enzymes to unmask antigenic determinants. With similar dilutions of the specific antiserum the PaP method gave less intense staining. Cytokeratins were detected in basal and columnar cells, in areas of transitional and squamous metaplasia and in normal transitional epithelium. Columnar cells showed strong staining in the supranuclear portion. Adenocarcinomas gave positive staining for cytokeratins varying from weak to strong. The intensity of staining showed no correlation with the degree of differentiation of the tumor. Different degrees of intensity were frequently observed within the same tumor. High dilutions of the specific antiserum (greater than 1/400) failed to stain carcinomas or stained them poorly, whereas they still stained normal or hyperplastic tissues. Gland-forming tumors showed a highly polarized labelling with the strongest staining in the luminal portion of the cell. The conclusion is that all epithelial prostatic tissues, benign and malignant, express cytokeratins.
 ...
PMID:Demonstration of cytokeratins by immunoperoxidase staining in prostatic tissue. 241 67

Paraffin sections of formaldehyde-fixed renal biopsies were labeled for complement C3 by a polyclonal rabbit antibody to human complement C3, by the peroxidase-antiperoxidase complex (PAP) and the avidin-biotin peroxidase complex (ABC) techniques, respectively. All tissues had C3 deposits according to direct immunofluorescence on fresh frozen sections. Staining for muramidase was introduced as an intrinsic control for the degree of tissue proteolysis after the necessary trypsin digestion prior to the immunoenzyme labeling. The results indicated that even minute deposits of C3 could be detected in paraffin sections by the ABC method, which was more sensitive than the PAP technique; the ABC method allowed a maximal dilution of 1:2,400 of the primary antibody as compared to 1:800 for the PAP technique.
 ...
PMID:Conditions for the immunohistochemical demonstration of complement factor C3 in formaldehyde-fixed and paraffin-embedded renal tissues. 242 Jul 64

Using specific antibodies and the peroxidase-antiperoxidase technique, we were able to demonstrate a variety of fungal organisms in smears and sections of formaldehyde-fixed, paraffin-embedded tissue. The procedure is simple, fast, and accurate and may be used as an alternative to, or in conjunction with, cultural methods to identify fungi specifically.
 ...
PMID:Immunohistologic identification of fungi in systemic and cutaneous mycoses. 242 90

A simple post-embedding technique for the electron microscopical detection of lectin-binding sites using thin sections of tissues embedded in the resin LR White is described. With this technique, no prior etching of the sections is necessary. The cellular fine structure is well preserved and permits close correlation of the labelling to distinct cellular compartments. After mild aldehyde fixation (4% formaldehyde and 0.5% glutaraldehyde for 30 min), enterocyte brush border, vesicles and lysosomes as well as goblet cell Golgi apparatus and mucin are intensely stained after 30-60 min. The hydrophilia and penetrability of LR White is shown by the formation of oxidized diaminobenzidine reaction product arising from horseradish peroxidase-conjugated lectins. The precipitate not only covers the surface of the sections but is also formed within the resin, as is revealed on cross-sections through thin and semithin sections. The addition of 0.2 M solutions of the appropriate inhibitory sugars prevented staining, which indicates a specific binding. Examples are given of the binding of gold-, ferritin- and peroxidase-conjugated lectins for the purpose of detecting glycoconjugates in various intracellular compartments.
 ...
PMID:Post-embedding localization of glycoconjugates by means of lectins on thin sections of tissues embedded in LR white. 242 41

The effect of three proteases--trypsin, pepsin, and pronase--on the immunohistochemical staining of keratins with a broad-spectrum monoclonal antibody was investigated in paraffin sections of formalin and ethanol-fixed tissues by means of the peroxidase-antiperoxidase method. Both the length of exposure to the fixative and the duration of proteolysis were varied over a wide range. Ethanol-fixed tissues showed excellent preservation of the antigenicity of keratins, and no appreciable differences in immunostaining related to the length of fixation were found. The use of proteolytic enzymes did not improve these results; on the contrary, it caused rapid tissue disintegration. Formalin-fixed epithelial tissues stained weakly or failed to stain unless they were treated with a proteolytic enzyme. The optimal length of proteolysis varied with the degree of fixation; tissues that were fixed for long periods of time in formalin required longer exposure to a proteolytic enzyme and were more resistant to digestion than were tissues that were fixed briefly. No significant advantage of one protease over another was found in this study. We conclude that a proteolytic step must precede immunostaining for keratins if the tissue is fixed in formalin, but that the digestion period must be adjusted according to the length of exposure to the fixative. The superiority of alcohol over formalin fixation for the preservation of the antigenicity of keratins is confirmed by this study.
 ...
PMID:The influence of protease digestion and duration of fixation on the immunostaining of keratins. A comparison of formalin and ethanol fixation. 242 35

The expression of vimentin in pulmonary carcinomas was studied in 285 cases of surgically resected lung cancer from our hospital files. Formalin fixed, paraffin-embedded sections were studied by immunoreactive staining techniques using two monoclonal antibodies against vimentin. Cases demonstrating vimentin positivity by the avidin-biotin-peroxidase method included 11 of 129 adenocarcinomas studied (8.5%), and 15 of 61 large cell carcinomas studied (24.6%). Vimentin expression was not seen in any of the 51 squamous cell carcinomas or 35 small cell carcinomas in our series. The positive cases of adenocarcinoma were in moderately and poorly differentiated cancers. Four of the eight giant cell carcinomas (50%) demonstrated vimentin expression. All cases that exhibited vimentin positivity were studied for cytokeratin expression. Coexpression of vimentin and cytokeratin was demonstrated not only within the same tumor but also within the same cells in some cases stained by double antibody technique, including both adenocarcinomas and large cell carcinomas. Similar immunoreactive methods were also applied to sections from human lung cancer transplants grown in the nude mouse. Of 28 tumors studied, four of 11 adenocarcinomas (36%) and all 4 large cell carcinomas demonstrated coexpression of vimentin and cytokeratin, while none of the five squamous cell carcinomas or eight small cell carcinomas expressed vimentin.
 ...
PMID:Expression of vimentin in surgically resected adenocarcinomas and large cell carcinomas of lung. 242 81


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>