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At least 901 records · Page 50Linked to original sources
PubMed2004

Use of paraffin-embedded tissue for identification of Saccharomyces cerevisiae in a baker's lung nodule by fungal PCR and nucleotide sequencing.

A 40-year-old healthy male employed in a bakery presented with a single lung nodule and underwent investigations to rule out pulmonary carcinoma. Biopsy was positive for yeast cells, which did not match common fungal pathogens. PCR assay of paraffin-embedded tissue and nucleotide sequencing with ribosomal ITS1-ITS2 universal primers revealed the presence of Saccharomyces cerevisiae.

Adult↗
PubMed1996

Rapid detection of mycobacteria in inflammatory necrotizing granulomas from formalin-fixed, paraffin-embedded tissue by PCR in clinically high-risk patients with acid-fast stain and culture-negative tissue biopsies.

A collection of inflammatory necrotizing granulomas (INGs) negative by acid-fast stain and culture (AFSC) were analyzed by polymerase chain reaction (PCR) for the presence of mycobacteria. Forty-two paraffin-embedded specimens with INGs were collected from patients at high risk for contracting tuberculosis. Twenty biopsies were positive and 22 were negative for mycobacteria by AFSC. Two universal primers specific for all mycobacteria were used to detected a 414 base pair (bp) fragment of 16S rRNA gene. Twenty of 20 biopsies were positive for mycobacteria by both AFSC and PCR (100%), whereas 19 of 22 biopsies negative by AFSC were positive by PCR (86%). Follow-up of patients who were PCR positive but AFSC negative identified nine patients who had subsequent biopsies. Specimens from eight of these nine patients eventually grew Mycobacterium tuberculosis. Our results demonstrate that the detection of mycobacterial DNA by this method should be used in conjunction with AFSC for the initial diagnosis of mycobacterial infection.

Adolescent↗
PubMed1997

Chromosomal rearrangement t(11;22) in extraskeletal Ewing's sarcoma and primitive neuroectodermal tumour analysed by fluorescence in situ hybridization using paraffin-embedded tissue.

The clonal chromosomal rearrangement t(11;22) has been reported by karyotypic analysis to be specific for Ewing's sarcoma of bone and soft tissue origin as well as primitive neuroectodermal tumour. In this report, immunohistological analysis of MIC 2 expression and fluorescence in situ hybridization (FISH) were performed using paraffin-embedded tissues. We examined t(11;22) in the nuclei isolated from two Ewing's sarcomas, four primitive neuroectodermal tumours, and three neuroblastomas, which served as negative controls by FISH with an alpha-satellite DNA probe for chromosome 11, a chromosome 22 marker probe, and whole chromosome painting probes for both chromosomes 11 and 22. Both cases of Ewing's sarcoma and the four primitive neuroectodermal tumour specimens were immunoreactive for MIC 2. Both Ewing's sarcomas and three of the four primitive neuroectodermal tumours contained the tumour-specific t(11;22), but the three neuroblastomas did not show this translocation. Based on the cytogenetic results and on the immunohistological investigation of MIC 2 expression, Ewing's sarcoma is suggested to be related closely to primitive neuroectodermal tumour. FISH is a useful aid in determining the tumour type of Ewing's sarcoma and putative related tumours.

12E7 Antigen↗
PubMed1986

The AMeX method. A simplified technique of tissue processing and paraffin embedding with improved preservation of antigens for immunostaining.

A new simplified tissue processing method for immunostaining was devised. Tissues were fixed in acetone at -20 C overnight, then cleared in methyl benzoate and xylene, consecutively, and embedded in ordinary paraffin at 58-60 C. Thin paraffin sections were deparaffinized with xylene, immersed in acetone and then phosphate buffered saline, and immunostained with various monoclonal and conventional antibodies, which have only been used on fresh-frozen or PLP-fixed frozen sections. As with PLP-fixed frozen sections, the following antigens were clearly demonstrated in the tissue sections processed with the present method: T (Leu-1, Leu-2a, Leu-3a, Leu-4, OKT3, OKT4, OKT8), B (B1, B2, Leu-14, IgM, IgD) lymphocyte surface markers and other antigens (Leu-7, OKT6, OKT9, OKM1, OKI1, J5, Ki-1, Ki-67, TdT, oncogene Ha-ras P21). Sections prepared by the present method demonstrated much better histologic and cytologic preservation than possible in frozen sections.

Acetone↗
PubMed1978

[The indirect immunofluorescent antibody test with paraffin-embedded histological sections as antigen in experimental echinococcosis (author's transl)].

A modification of the indirect immunofluorescent antibody test for the diagnosis of infections with metacestodes of Echinococcus multilocularis is described. Formol alcohol was used as fixative mixture for the antigen materials; as embeding medium served paraffin. In positive reactions the peripheral protoscolex-layers showed a bright yellow-green fluorescence. Specificity and sensibility in the animal model experiment are to be expressed as very good.

Animals↗
PubMed1994

Immunohistochemical detection of p185 product, p21 product, and proliferating cell nuclear antigen (PCNA) in formalin-fixed, paraffin-embedded tissues from ovarian carcinomas. Preliminary data.

Immunohistochemical techniques for the detection of oncogene products and the assessment of cell kinetics can represent promising investigational tools in clinical oncology. In the present paper the immunohistochemical expression of p185, p21 and proliferating cell nuclear antigen (PCNA) was retrospectively assessed in formalin-fixed, paraffin-embedded tissue samples taken from 28 primary ovarian carcinomas at first surgery. Positive immunostaining for p185 was found in 0% of 6 Stage I and 23% of 22 Stage III-IV tumors. Positive immunostaining for p21 was observed in 0% of early and 41% of advanced carcinomas; this immunohistochemical finding correlated significantly with histologic grade (G3 vs G1-2 = 47% vs 9%, p = 0.042). Elevated PCNA immunoreactivity was detected in 33% of Stage I and 50% of Stage III-IV tumors. Among the 20 patients with advanced carcinoma who underwent cisplatin or carboplatin based chemotherapy followed by second-look laparotomy, the pathologic complete response (pCR) rate was 36% for patients with low PCNA expression and 0% for those with elevated PCNA expression. A tendency towards a higher pCR rate was also found for patients with negative immunostaining for p185 or for p21. The prognostic value of the immunohistochemical detection of p185, p21, and PCNA in ovarian carcinoma deserves to be further investigated.

Adenocarcinoma, Mucinous↗
PubMed2000

Bcl-2 molecular analysis in paraffin-embedded biopsies from diffuse large B-cell lymphomas.

Translocation t(14; 18) has been observed in 50-85% of follicular and in 30% of diffuse non-Hodgkin lymphomas. About half of follicle center lymphoma (FCL) undergo histological conversion at relapse to more aggressive diffuse large B-cell lymphoma (DLBCL). This report correlates the molecular bcl-2/IgH rearrangement by PCR and Bcl-2 immunohistochemical (IHC) expression in a series of high grade DLBCLs with and without FCL remnant. Twenty-three paraffin-embedded lymph nodes from DLBCL patients were analyzed. Eleven patients showed FCL remnant (Group A) and 12, did not (Group B). Single PCR from paraffin extracted DNA followed by Southern transfer of products, hybridisation with internal oligoprobes for the MBR/JH and MCR/JH bcl-2 rearrangements and IHC analysis of Bcl-2 expression, were performed. PCR analysis was positive in 34.8% of patients. Bcl-2/IgH gene rearrangements were observed in 8 (34%) cases and 7 (30%) showed Bcl-2 expression on large noncleaved B-cells (centroblasts). All patients from Group A showed IHC positive reaction on FCL remnant (small cleaved cells) but only 2 (18%) were positive in DLBCL areas, suggesting either the loss of the bcl-2 expression on the transformed lymphoma, or, alternatively, the development of a second disease when the first lymphoma transforms. Group B patients showed a clear correlation between PCR and IHC studies. Our results suggest a similar frequency of t(14; 18) in DLBCLs to that reported in Europe and USA series. The discordance observed between PCR and IHC, particularly in Group A, points out the necessity to perform both studies in order to detect bcl-2 gene involvement in DLBCLs.

Adult↗
PubMed1991

An improved Hedley method for preparation of paraffin-embedded tissues for flow cytometric analysis of ploidy and S-phase.

A modification of the Hedley-method for flow cytometric DNA analysis of paraffin-embedded tissues is presented. Dewaxed and dehydrated tissue from paraffin blocks was incubated with subtilisin Carlsberg (pronase, Sigma protease XXIV) and then stained directly without washing and centrifugation. The loss of material was minimized, which was advantageous, for example, for the analysis of core-biopsies, and all measured samples showed extremely low frequencies of clumped cell nuclei. This made is easier to detect polyploid nuclei and even rare nuclei of high ploidy could be identified. S-phase analyses were more precise, since the background originating from clumped debris particles was very low. The improved method was applied to the estimation of frequencies of high-polyploid nuclei found in various diploid, tetraploid, and aneuploid human myosarcomas of the uterus.

Biopsy↗
PubMed2003

A simple method for RNA isolation from formalin-fixed and paraffin-embedded lymphatic tissues.

Gene activation that lies beneath lymphoid cell differentiation has been one of the most explored issues in immunology in the recent years. However, the analysis of this molecular event in lymphoproliferative diseases is often hampered by the lack of fresh material. Most tissues available for routine histological investigation are formalin fixed and paraffin embedded. Gene expression in such specimens could be analyzed using reverse transcription of mRNA and the polymerase chain reaction (RT-PCR). Therefore we adjusted and established a method for mRNA isolation from such specimens by a combination of previously reported protocols and a modification of the phenol/chloroform extraction method. Given the significance of transcription factors in the human hemopoietic system, we investigated whether mRNA could be successfully isolated from archival tissue for a study on expression of Ikaros family transcription factors in lymphatic tissue. Although quantitative analysis of RNA isolated from archival tissue is probably not feasible due to the unpredictable degree of RNA isolation varying from sample to sample, we show here that screening analysis is possible and simple.

DNA Primers↗
PubMedDate not supplied

A simple method for the preparation of paraffin-embedded cell blocks from fine needle aspirates, effusions and brushings.

A simple method for the preparation of paraffin-embedded cell blocks from cytologic specimens obtained by fine needle aspiration, by brushing or from effusions is described. The cells are fixed in suspension in 50% ethanol for one hour and pelleted by centrifugation in a 50-mL plastic tube. The fixative is removed, and the pellet is suspended in 3 mL of acetone for dehydration for ten minutes and thereafter repelleted. The acetone is then removed, and the cell pellet is dried at 60 degrees C for one hour. Melted paraffin is added onto the dry warmed cell mass and allowed to solidify at room temperature. A conical paraffin block with the cells in the top is obtained and can be handled as a routine tissue block.

Biopsy, Needle↗
PubMed1989

Immunohistochemical demonstration of complement components in formalin-fixed and paraffin-embedded renal tissues.

Although there are many articles describing the detection of complement components in formalin-fixed and paraffin-embedded renal tissues, it is still difficult to obtain reproducible results. The authors determined the optimal conditions for detecting complement components in routine paraffin sections by the avidin-biotin-peroxidase complex method and concluded that proteolytic digestion of the deparaffinized sections was crucial to detect complement and to preserve tissue structures. The optimal proteolytic digestion was a 15-minute incubation at 37 degrees C in trypsin solution, 0.5 mg/ml, pH 7.6. Under these conditions, all of the complement components so far studied (C1q, C1s, C4, C3c, C3b, C5, C6, C9, and properdin) were detected without significant destruction of tissue structures in 52 renal biopsy specimens from patients with various forms of glomerulonephritis. Immunohistochemistry using the avidin-biotin-peroxidase complex method was equivalent to indirect immunofluorescence and superior to direct immunofluorescence in utility and was useful in the diagnosis of glomerular diseases.

Complement System Proteins↗
PubMed2026

Antibody-Based Proximity Labeling Reveals Bait-Proximal Proteomes in Paraffin-Embedded and Snap-Frozen Tissue Samples.

Proximity-based labeling approaches have proven highly valuable for uncovering protein-protein interactions, yet their application to primary patient material remains challenging. Here, we present a workflow enabling the use of the antibody-based ProtA-Turbo proximity labeling system in both formalin-fixed paraffin-embedded (FFPE) and snap-frozen tissue specimens. Our method efficiently directs biotinylation to diverse antibody baits across tissues of different origins. Downstream mass spectrometry-based proteomics analyses demonstrate the specificity of the method by profiling the proximal proteome of H3K27ac-marked chromatin, the nuclear lamina-associated protein EMD, and the Ser2-phosphorylated POLR2A subunit of RNA polymerase II. Using this method, we identified cell-type-specific factors and transcriptional regulators in salivary gland carcinoma, healthy testis, and testicular cancer tissue sections. The ability to detect disease-associated complexes directly within their native, spatially resolved cellular context using ProtA-Turbo can provide new insights into the molecular basis of human disease and may reveal novel, potentially actionable factors with translational relevance.

Humans↗
PubMed2006

Direct cancer tissue proteomics: a method to identify candidate cancer biomarkers from formalin-fixed paraffin-embedded archival tissues.

Successful treatment of multiple cancer types requires early detection and identification of reliable biomarkers present in specific cancer tissues. To test the feasibility of identifying proteins from archival cancer tissues, we have developed a methodology, termed direct tissue proteomics (DTP), which can be used to identify proteins directly from formalin-fixed paraffin-embedded prostate cancer tissue samples. Using minute prostate biopsy sections, we demonstrate the identification of 428 prostate-expressed proteins using the shotgun method. Because the DTP method is not quantitative, we employed the absolute quantification method and demonstrate picogram level quantification of prostate-specific antigen. In depth bioinformatics analysis of these expressed proteins affords the categorization of metabolic pathways that may be important for distinct stages of prostate carcinogenesis. Furthermore, we validate Wnt-3 as an upregulated protein in cancerous prostate cells by immunohistochemistry. We propose that this general strategy provides a roadmap for successful identification of critical molecular targets of multiple cancer types.

Amino Acid Sequence↗
PubMed2005

The application of a monoclonal antibody to CD62L on paraffin-embedded tissue samples in the assessment of the cutaneous T-cell infiltrates.

BACKGROUND: A reduction in the expression of the pan T-cell markers CD7 and CD62L supports an endogenous T-cell dyscrasia. Previously, clone availability for CD62L restricted its application to frozen tissue sections. MATERIALS AND METHODS: A nonavidin/biotin technique to examine CD3, CD62L, and CD7 in paraffin formalin-fixed tissue in non-neoplastic and neoplastic T-cell infiltrates. RESULTS: In the reactive group, CD62L manifested a 15 and 22% reduction in epidermal and dermal staining, respectively; there was a 42 and 31% reduction in epidermal and dermal CD7 staining. In lymphomatoid hypersensitivity, CD62L showed a 24 and 9% reduction in epidermal and dermal staining, respectively; CD7 staining demonstrated reduced staining by 70 and 66% in the epidermis and dermis. In the non-lymphomatous endogenous T-cell dyscrasia and lymphoma categories, an 80% diminution in CD62L and CD7 expression was seen. CONCLUSIONS: CD62L can be successfully applied in formalin-fixed tissue and exhibits enhanced specificity compared to CD7 in the evaluation of cutaneous T-cell infiltrates. Both CD62L and CD7 in paraffin-embedded, formalin-fixed tissue are useful diagnostic adjuncts, especially in regard to the discrimination of lymphomatoid hypersensitivity reactions from true endogenous T-cell dyscrasia.

Antibodies, Monoclonal↗
PubMed2005

A study of glutathione S-transferase pi expression in central nervous system of subjects with amyotrophic lateral sclerosis using RNA extraction from formalin-fixed, paraffin-embedded material.

The expression of glutathione S-transferase pi (GST pi), an enzyme responsible for inactivation of a large variety of toxic compounds was studied in spinal cord, motor and sensory brain cortex obtained from patients who died in the course of amyotrophic lateral sclerosis (ALS). The studies were performed on formalin-fixed, paraffin-embedded (FFPE) and freshly frozen tissues. The method of RNA isolation from FFPE was modified. A significant decrease of GST pi-mRNA expression was found in cervical spinal cord and motor brain cortex of ALS subjects comparing to analogue control tissues (P<0.01), as well as in motor cortex of ALS subjects comparing to their sensory cortex (P<0.05). In spinal cords the decrease in GST pi-mRNA expression was accompanied by a decrease of GST pi protein level. Results indicated lowered GST pi expression on both mRNA and protein levels in the regions of nervous system affected by ALS. The non-properly inactivated by GST toxic electrophiles and organic peroxides may thus contribute to motor neurons damage.

Adult↗
PubMed1993

Demonstration of cells of the mononuclear phagocyte lineage in the periodontium following experimental tooth movement in the rat. An immunohistochemical study using monoclonal antibodies ED1 und ED2 on paraffin-embedded tissues.

In this immunohistochemical study two monoclonal antibodies, ED1 and ED2, which recognize exclusively cells of the mononuclear phagocyte system (MPS) in the rat, were applied to study the presence of these cells during remodeling of the periodontal tissues following mechanically induced orthodontic tooth movement. The immunohistochemical procedure was carried out successfully on routinely processed, paraffin-embedded histological sections using the avidin-biotin-peroxidase-complex (ABC) technique. Cells of the MPS could be demonstrated on positive control sections of rat spleen and bone marrow. For the study of remodelling of the periodontal tissues only the ED1 antibody proved to be suitable. With this antibody, positive mononuclear and multinuclear cells, i.e. macrophages and osteoclasts, were seen throughout the periodontium even in the control animals. After the induction of orthodontic tooth movement activation of macrophages, osteoclasts and odontoclasts was demonstrable, all of them showing a clear-cut positive reaction to ED1.

Animals↗
PubMed1995

Immunocytochemical detection of ornithine decarboxylase (ODC) in paraffin-embedded tissues as a possible prognostic indicator for oral lesions.

Intracellular levels of ornithine decarboxylase (ODC) are raised following mitogenic stimulus and in neoplasia. Because lesions of the oral cavity are often difficult to assess histologically, we have determined the value of immunocytochemical detection of ODC as a prognostic indicator in 74 routinely fixed and paraffin-embedded oral biopsies using peroxidase-antiperoxidase and immunogold-silver staining. The latter proved more sensitive, yielding positive reactions in 32 of 43 oral carcinomas (11/14 well differentiated, 16/21 moderately differentiated and 3/5 poorly differentiated) and 7/11 potentially malignant lesions, compared with 19/45 carcinomas and 1/15 potentially malignant lesions, by peroxidase anti-peroxidase. Hyperplastic lesions (n = 7) and normal non-keratinized buccal mucosa (n = 7) were all negative. Follow-up was possible in 13 of the carcinoma patients. Of 7 positive ODC reactions but clinically node-free at biopsy, 2 died and 2 had recurrences within 3 years, whereas all of 6 with no immunoreactivity were symptom-free after 3-5 years. Immunostaining for ODC may be helpful for the prognostic assessment of routinely processed oral lesions and in choosing treatment.

Animals↗