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At least 793 records · Page 44Linked to original sources
PubMed1978

A correlative chemical and histochemical study of the O-acetylated sialic acids of human colonic epithelial glycoproteins in formalin fixed paraffin embedded tissues.

Procedures are described for the isolation and identification of epithelial glycoproteins from formalin fixed, paraffin embedded specimens of human large intestine. The side chain O-acetylation patterns of the sialic acids of these glycoproteins were surprisingly similar to those of purified glycoproteins prepared from epithelial cells obtained from the same tissue before fixation. These results were consistent with those obtained by histochemical procedures performed on representative sections taken from the same tissue blocks. The methodology described permits a direct correlation of chemical and histochemical results obtained from the study of colonic epithelial glycoproteins of both normal and diseased tissues. It eliminates some of the difficulties associated with interpretation of the results by either discipline and may provide new information which would be unavailable by either chemistry or histochemistry alone.

Acetylation↗
PubMed1992

Frequent expression of haemopoietic and non-haemopoietic antigens by neoplastic plasma cells: an immunohistochemical study using formalin-fixed, paraffin-embedded tissue.

There is increasing evidence that neoplastic plasma cells express various haemopoietic and non-haemopoietic antigens. Since this issue could raise problems in diagnostic histopathology, we have investigated 51 cases of multiple myeloma (plasmacytoma) systematically with a broad panel of antibodies applicable on paraffin-embedded and mildly decalcified tissue. In approximately 90% of the cases the neoplastic plasma cells reacted with at least one antibody detecting haemopoietic antigens: MB2 (75%), DF-T1/CD 43 (59%), UCHL1/CD 45RO (47%), Ki-B3 (41%), anti-LCA/CD 45 (40%), L26/CD 20 (26%), 4KB5/CD 45RA (18%), Ber H2/CD 30 (10%), anti-neutrophil elastase (4%), anti-Leu-7/CD 57 (8%), Dako-M1/CD 15 (2%), KP1/CD 68 (2%) and anti-glycoprotein IIIa (2%). In approximately 70% of the cases the cells reacted with antibodies against non-haemopoietic antigens: anti-epithelial membrane antigen (65%), BMA120 (53%), anti-vimentin (44%), anti-pan-cytokeratin/KL1 (8%), anti-carcino-embryonic antigen (6%) and HMB45 (6%). Lack of awareness of the frequent expression of both haemopoietic and non-haemopoietic antigens by neoplastic plasma cells could lead to mis-diagnosis of plasmacytomas as malignant lymphomas or even as carcinomas or sarcomas.

Adult↗
PubMed2006

The specificity of interphase FISH translocation probes in formalin fixed paraffin embedded tissue sections is readily assessed using automated staining and scoring of tissue microarrays constructed from murine xenografts.

Implementation of interphase fluorescence in situ hybridization (FISH) assays in the clinical laboratory requires validation against established methods. Validation tools in common use include exchange of consecutive sections with another institution that has already established the FISH assay, comparison with conventional banded metaphase cytogenetics, confirmation of specificity using probed normal metaphases, consecutive paraffin sections of a validation set tested by a reference laboratory, and specificity assessment against well characterized cell lines. We have investigated the feasibility of using tissue microarrays (TMA) constructed from murine xenografts as a preliminary specificity-screening tool for validation of interphase FISH assays. Cell lines currently in use for FISH controls are used to generate xenografts in SCID mice which are fixed in formalin and paraffin embedded. A TMA is constructed using duplicate donor cores from the xenograft blocks. Xenografts used represent a wide range of translocations used routinely for formalin fixed paraffin embedded sections evaluated by FISH. Probe cocktails (Abbott-Vysis), for several non-random translocations associated with hematologic neoplasms and soft tissue sarcomas have been used in this manner. On-line deparaffinization, cell conditioning, and prehybridization steps are automated using a staining workstation (Ventana Discovery XT); hybridization and stringency washes are performed manually offline. FISH-probed TMAs are tracked using a Metasystems image scanner and analyzed using classifiers specifically developed for each molecular abnormality. FISH results for each xenograft in the TMA correspond exactly to the genotype previously established for the parent cell line from which the xenograft was prepared. Moderate complexity tissue microarrays constructed from murine xenografts are excellent validation tools for initial assessment of interphase FISH probe specificity.

Animals↗
PubMed1991

A6--a new 45RO monoclonal antibody for immunostaining of paraffin-embedded tissues.

The authors report on the extensive characterization, on normal and pathologic tissues, of the T-cell-specific monoclonal antibody (MoAb) A6, which the authors previously found to identify a fixation- and paraffin-embedding-resistant epitope. A6 reacted with most T lymphocytes, macrophages, and Langerhans' cells of normal tissues and with peripheral T-cell lymphomas (31 of 34), Ki-1+ lymphomas (12 of 18), and T-cell leukemias (1 of 5). All cases of X and non-X histiocytosis examined and monocytic leukemias with mature phenotype only were A6 positive. Three of 47 cases of B-cell lymphoma and leukemia were labeled. Hairy cell leukemias, multiple myelomas, and Hodgkin's and Reed-Sternberg cells were negative. The A6 reactivity was preserved with different fixatives (formalin, Bouin's fluid, Carnoy's fixative, and B5) and decalcification procedures and was slightly enhanced by trypsin digestion. The pattern of reactivity of A6 was similar to that obtained with MoAb UCHL-1, recognizing the CD45RO determinant of leukocyte common antigen; however, in pathologic tissues, A6 labeled a higher percentage of cells than UCHL-1. Cross-blocking and enzyme digestion studies (Pronase E [Sigma Chemical, St. Louis, MO] and neuraminidase [Sigma Chemical]) indicated that the two MoAbs may identify close epitopes on the same molecule. In conclusion, the authors' study indicates that A6 is an excellent reagent for detection of the CD45RO molecule on paraffin-embedded normal and pathologic tissues.

Antibodies, Monoclonal↗
PubMed1990

DNA ploidy, tumour site, and prognosis in colorectal cancer. A flow cytometric study of paraffin-embedded tissue.

DNA ploidy patterns were studied by flow cytometry in nuclear suspensions from 149 paraffin-embedded colorectal adenocarcinomas. The DNA ploidy of rectal tumours was not significantly different from that of colonic tumours. Patients with DNA diploid tumours had a significant survival advantage compared with patients with non-diploid tumours, but DNA ploidy did not confer any significant additional prognostic information when tumour site, Dukes's stage, the invasiveness of the tumour, and the number of lymph node metastases were adjusted for in a proportional hazards regression analysis (Cox). It is concluded that DNA ploidy does not contribute significantly to the explanation of why patients with rectal cancer have a poorer prognosis than those with colonic cancer.

Adenocarcinoma↗
PubMed2005

Detection of papillomavirus proteins and DNA in paraffin-embedded tissue sections.

The key events during the papillomavirus life cycle can be mapped in infected tissue samples by antibody detection and in situ hybridization. The ease of immuno-detection varies for different proteins and is dependent on antigen availability. Epitope exposure is sometimes necessary, because the antigen may become masked after formalin fixation and paraffin embedding of the infected tissue. Visualization of both nucleic acid and protein targets can be done simultaneously by combining in situ hybridization and immuno-detection methods.

Antigens, Viral↗
PubMed2004

Evaluation of the predictive value of Her-2/neu gene expression on osteosarcoma therapy in laser-microdissected paraffin-embedded tissue.

Histologic response to chemotherapy is currently the strongest prognostic factor in high-grade osteosarcoma, but it can only be assessed after several weeks of therapy. Thus, detection of chemosensitivity at the time of diagnosis would be of great clinical importance. The expression of the proto-oncogene Her-2/neu has been shown to be of predictive value in breast cancer and has also been considered as prognostic marker for osteosarcomas, but reports of mainly immunohistochemical studies are controversial. Therefore, the aim of this study was to investigate Her-2/neu gene expression in laser-microdissected osteosarcoma cells. Laser microdissection enables the precise isolation of morphological defined cells from archival tissue specimens and is in combination with the highly sensitive real-time RT-PCR technique a valuable tool for cell-specific analysis of gene expression. Through optimization of current protocols, we could show that this technique can be successfully applied on formalin-fixed, paraffin-embedded and decalcified osteosarcoma tissue with high sensitivity and reproducibility. In all 17 osteosarcoma biopsies analyzed, we could detect Her-2/neu gene expression. Expression correlated significantly with the response to preoperative chemotherapy, which was assessed histologically according to the six-grade scale of Salzer-Kuntschik. Risk assessment on the basis of increased Her-2/neu gene expression matched the histologic findings in 16 out of 17 cases (94%). These data demonstrate the reliability of laser microdissection in the analysis of gene expression and suggest a possible role of Her-2/neu as prognostic marker for therapy outcome in osteosarcomas.

Antineoplastic Agents↗
PubMed1993

Antigen unmasking on formalin-fixed, paraffin-embedded tissue sections.

Enzymatic and non-enzymatic treatments for antigen unmasking on formalin-fixed, paraffin-embedded, dewaxed sections were optimized and compared by the use of a panel of antibodies of diagnostic relevance (anti-cytokeratins, vimentin, S-100, T- and B-cell receptors, Ki-67/MIB 1, muscle actin). Non-enzymatic unmasking was obtained by boiling the slides in a microwave oven in 0.01 M salt solution (pH 6) or in 6 M urea. Trypsin or pronase digestion was used for comparison and found to be necessary for some of the reagents. The investigation was then extended to 256 antibodies; the epitopic amino acid sequence was known for 48 of them. We found that enzymatic and non-enzymatic antigen unmasking are not dependent on the epitope sequence, but some antigens benefit selectively from one treatment but not from the other. Denaturation of proteins is the likely mechanism which leads to immunodetection on microwave oven-boiled slides; this suggestion is supported by the use of denaturating solutions and by the observation that endogenous enzymes were inactivated and a few antigens were no longer immunodetectable after boiling. Non-enzymatic methods for antigen unmasking are a powerful new tool for broadening the use of antibodies for immunostaining formalin-fixed, paraffin-embedded sections and should be used in parallel with the traditional enzymatic methods.

Antibodies↗
PubMed1984

Lectin-binding histochemistry of non-decalcified growth plate cartilage: a postembedment method for light microscopy of epon-embedded tissue.

A postembedment method for the localization of lectin-binding glycoconjugates was developed using Epon-embedded growth plate cartilage from Yucatan miniature swine. By testing a variety of etching, blocking, and incubation procedures, a standard protocol was developed for 1 micron thick sections that allowed visualization of both intracellular and extracellular glycoconjugates with affinity for wheat germ agglutinin and concanavalin A. Both fluorescent and peroxidase techniques were used, and comparisons were made between direct methods and indirect methods using the biotin-avidin bridging system. Differential extracellular lectin binding allowed visualization of interterritorial , territorial, and pericellular matrices. Double labeling experiments showed the precision with which intracellular binding could be localized to specific cytoplasmic compartments, with resolution of binding to the Golgi apparatus, endoplasmic reticulum, and nuclear membrane at the light microscopic level. This method allows the localization of both intracellular and extracellular lectin-binding glycoconjugates using fixation and embedment procedures that are compatible with simultaneous ultrastructural analysis. As such it should have applicability both to the morphological analysis of growth plate organization during normal endochondral ossification, as well as to the diagnostic pathology of matrix abnormalities in disease states of growing cartilage.

Animals↗
PubMed1989

Detection of T cells in paraffin wax embedded tissue using antibodies against a peptide sequence from the CD3 antigen.

Rabbit polyclonal antibodies were raised against a proline rich, peptide sequence, comprising 13 amino acids, in the cytoplasmic domain of the CD3 epsilon chain. Immunoprecipitation experiments showed that this antibody preparation recognised the CD3 antigen on human T lymphoblasts. The antibody stained normal T cells strongly in tissue sections which had been fixed in formalin or Bouin's solution and embedded in paraffin wax. Its reactivity with T cell lymphoma, when evaluated on a series of 96 previously phenotyped cases, closely agreed with the results obtained on cryostat sections. These results indicate that the specific detection of T cells in routinely processed tissue biopsy specimens is now technically feasible on a wide scale in diagnostic laboratories using CD3 peptide antibodies, and they also suggest that in future the use of anti-peptide antibodies may detect other lineage specific antigenic markers in paraffin wax sections.

Amino Acid Sequence↗
PubMed1988

[Immunohistochemical labeling of immunoglobulin antigens in semithin sections of epoxy resin-embedded tissue using the gold-silver technic].

The silver nitrate variant of the immunohistochemical gold-silver technique is applied to label L-chains within immunoglobulin containing cells in semithin sections of epoxy resin embedded human tonsils. Different possibilities of tissue fixation and of reactivation of antigens are tested. The best results are obtained by paraformaldehyde-sublimate fixation of tissue and potassium iodide processing of sections. This method allows a good preservation of both tissue and antigens and a sensitive labelling of the immunoglobulin antigens by means of the gold-silver technique.

Antigens↗
PubMed2003

Expression profiling of mouse endometrial cancers microdissected from ethanol-fixed, paraffin-embedded tissues.

Expression-profiling studies have helped define genetic changes associated with carcinogenesis. Determining which alterations in gene expression are causally associated with cancer and which result from the general dysregulation in gene expression that is characteristic of malignancies remains a problem. Transcriptional profiling of early lesions (small cancers or precancers) holds promise for identifying biologically important changes in gene expression. There are, however, technical barriers to the study of small tumors. The total number of cells available for analysis is limiting. It is also often difficult to distinguish cancer cells from normal proliferating cells in frozen sections that are typically used as a source of RNA. Here we describe an ethanol fixation and paraffin-embedding protocol that preserves tissue architecture and cellular morphology of the mouse endometrium, and allows for the recovery of high-quality RNA from microdissected cells. We performed GeneChip expression profiling using RNA from 800 to 4400 cells microdissected from ethanol-fixed, paraffin-embedded uteri. Endometrial adenocarcinomas exhibited changes in the levels of a number of messages known to be abnormally expressed in cancer, and differential expression of additional transcripts not previously implicated in carcinogenesis. We confirmed increased Amd1 expression in RNAs from mouse endometrial carcinomas that were hybridized to GeneChips and validated overexpression of this transcript in additional tumors.

Animals↗
PubMed1993

Analysis of BCR/ABL abnormalities in mRNA from 20-year-old paraffin-embedded tissue for BCR/ABL rearrangement by polymerase chain reaction.

We studied whether it is possible to obtain sufficient mRNA from old paraffin-embedded samples of spleen and bone marrow for reverse transcription and polymerase chain reaction analysis. Spleen tissue from 6 subjects with chronic myelogenous leukemia was studied for rearrangement of BCR and ABL genes. Analysis was successful in 4 cases. These data indicate the feasibility of retrospective analysis of tissue samples of special interest by molecular techniques.

Adult↗