SEARCH · PubMed Health

Results for “Paraffin Embedding”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

PubMed1995

[A study on immunohistochemical detection of estrogen receptor in the breast cancer tissue--a comparison between routinely paraffin-embedded and frozen sections].

On immunohistochemical detection of estrogen receptor in the breast cancer tissue, we examined whether ER1D5 [Anti-estrogen receptor monoclonal antibody, clone ER1D5(MBL)] using routinely fixed paraffin-embedded section may take the place of ERICA [Estrogen receptor immunocytochemical assay kit (DAINABOT)] using frozen one or not. With 63 breast cancer cases, estrogen receptor was positive in 63.4% of the cases by ERICA, while in 25.4% and 28.6% by ER1D5 in which enhancement of the antigen with microwave heating (high frequency power 500W 5 minutes) and autoclave heating (121 degrees C, 20 minutes) had been carried out. At present, it is unreasonable for ER1D5 to take the place of ERICA. However, it is noteworthy that estrogen receptor is detectable with paraffin-embedded section although the rate of positivity is low. It is desirable that further development of the antibody for estrogen receptor in the breast cancer tissue with paraffin-embedded section will be continued.

Breast Neoplasms↗

PubMed2006

Diagnosis of clear cell sarcoma by real-time reverse transcriptase-polymerase chain reaction analysis of paraffin embedded tissues: clinicopathologic and molecular analysis of 44 patients from the French sarcoma group.

BACKGROUND: Clear cell sarcoma (CCS) is a rare tumor with a very poor prognosis that occurs predominantly in the distal extremities of young adults. Most patients bear the t(12;22) reciprocal translocation, which involves the EWS and ATF1 genes. The diagnosis of CCS usually is easy but may be challenging in unusual sites, and the detection of EWS-ATF1 fusion transcripts is helpful to rule out a metastatic melanoma. METHODS: Forty-four patients with CCS and 14 conventional melanomas were examined for the presence of EWS-ATF1 transcripts by using real-time polymerase chain reaction (PCR) analysis on paraffin embedded tissues, including frozen samples for 9 CCS samples and 9 melanoma samples. Prior to molecular analysis, the diagnosis of CCS was considered certain in 35 patients and as probable in 9 patients on the basis of location, histologic features, and immunohistochemical profile. Treatment modalities and follow-up were available for 41 patients with CCS. RESULTS: EWS-ATF1 fusion transcripts were detected in 38 paraffin embedded CCS tissues (86% of all samples; 93% of interpretable samples), 3 samples (7%) were negative, and 3 samples (7%) were considered uninterpretable. Fusion transcripts were detected in 7 of 9 samples for which the diagnosis of CCS was considered probable. EWS-ATF1 transcripts were not detected in the 14 samples of melanoma. Results from frozen tissues were concordant with those from all corresponding paraffin embedded samples. Twenty-eight of 41 patients (68%) experienced lymph node and/or distant metastasis, and the 5 year-survival rate was 44%. Mitotic index and histologic grade were predictive of survival and distant metastasis. CONCLUSIONS: The results of this study showed that the molecular detection of EWS-ATF1 fusion transcript by real-time PCR on paraffin embedded tissues is a sensitive and specific method for the diagnosis of CCS. It is an efficient tool for the diagnosis of unusual tumors, especially with regard to its distinction from melanoma. The current results also confirmed the poor prognosis for patients with this tumor type. Mitotic index and grade were predictive factors for survival and distant metastasis.

Adolescent↗

PubMed2002

Detection and differentiation of North American and European genotypes of porcine reproductive and respiratory syndrome virus in formalin-fixed, paraffin-embedded tissues by multiplex reverse transcription-nested polymerase chain reaction.

North American and European genotypes of porcine reproductive and respiratory syndrome virus (PRRSV) were distinguished in formalin-fixed, paraffin-embedded tissues from PRRSV-infected pigs by multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR). A method based on xylene deparaffinization followed by proteinase K digestion yielded RNA of quality for reliable and consistent RT-nPCR analyses. The PRRSV nucleic acid was detected in lung, mediastinal lymph node, tonsil, and liver samples from pigs inoculated with North American strain virus, European strain virus, or both North American and European strains. All 30 archival formalin-fixed, paraffin-embedded lung tissues from pigs naturally infected with PRRSV were positive for PRRSV by RT-nPCR amplication and gave a pattern that corresponded to the North American genotype. Multiplex RT-nPCR could be applied successfully to formalin-fixed, paraffin-embedded tissues for the detection and differentiation between North American and European genotypes of PRRSV.

Animals↗

PubMed1994

A simple technique for preservation of fixation-sensitive antigens in paraffin-embedded tissues.

Immunohistochemistry is a powerful tool for tissue diagnosis and research. Although the frozen section has remained the gold standard for this important approach to evaluation of antigens in tissues, there is widespread acknowledgment of many limitations. Routine paraffin-embedded sections ware widely used for morphological examination of tissues but are not optimal for antigen preservation. In this study, paraffin-embedded tissues fixed with a simple buffer containing zinc as the primary fixative were compared with tissues fixed with routine formalin, zinc-formalin, paraformaldehyde, ethanol, a variety of commercial (non-formalin-containing) fixatives that have been recommended for reduced toxicity and improved antigen survival, and frozen sections. Human lymphoid tissues and a group of antibodies to antigens (CD1, CD4, CD7, CD8, CD19) usually preserved only in frozen tissue were used as a model system. Fixation in a simple solution of zinc acetate and zinc chloride in a Tris-Ca acetate buffer resulted in antigen preservation comparable to that in frozen sections with antibodies to these cell surface markers. Morphological preservation was comparable to formalin-fixed sections. The work presents a new method that represents the closest approach yet to a technique that combines optimal antigenic survival with the convenience and morphological preservation of traditional formalin-fixed tissue embedded in paraffin.

Acetates↗

PubMed1995

Immunocytochemical detection of androgen receptor in human temporal cortex characterization and application of polyclonal androgen receptor antibodies in frozen and paraffin-embedded tissues.

Immunocytochemical and biochemical studies have demonstrated the presence of androgen receptor protein in various regions of the rodent and non-human primate cortex. Localization of androgen receptor in the human brain has, however, not been studied as extensively, because of difficulties in obtaining suitable tissue samples. In the present study, we have localized androgen receptors in both frozen and paraffin-embedded temporal cortex from epileptic patients undergoing resection. Polyclonal antibodies were raised against fusion proteins containing fragments of the human androgen receptor protein. The antibodies were affinity-purified against the corresponding fusion protein. Immunoprecipitation and Western blotting using extracts from human cell lines demonstrated the specificity of the antibodies for the human androgen receptor and lack of cross-reactivity with other steroid hormone receptors. Immunocytochemistry was performed on frozen and paraffin sections of human temporal cortex and in paraffin-embedded benign hyperplastic prostates (BPH), as well as prostate and breast carcinomas, by the streptavidin-biotin-peroxidase method. Antigen-retrieval was performed in paraffin-embedded sections using microwave irradiation. Specific nuclear and cytoplasmic immunoreactivity for androgen receptor was detected in neurons, astrocytes, oligodendrocytes, and microglia cells of the temporal cortex. In contrast, only nuclear staining was observed in BPH, prostate and breast carcinomas. Immunoprecipitation of human temporal cortex lysate and subsequent Western blot analysis demonstrated the expression of a 98 kDa immunoreactive protein, slightly smaller than the reported molecular weight of the wild-type androgen receptor. These results provide further evidence for the expression of androgen receptor in the human temporal cortex. The use of these immunocytochemical techniques should enable the retrospective determination of possible changes in androgen receptor expression in a variety of archival paraffin-embedded tissues, including samples of the human central nervous system.

Adolescent↗

PubMed1996

Amplification of human beta-actin gene by the reverse transcriptase-polymerase chain reaction: implications for assessment of RNA from formalin-fixed, paraffin-embedded material.

The polymerase chain reaction (PCR) is a powerful method that allows enzymatic amplification of rate target nucleic acid sequences. It has been applied to the amplification of viral genomes from paraffin-embedded pathology specimens. However, interpretation of negative results requires amplification of a housekeeping gene such as beta-actin. In the present study we used specific oligonucleotide primers previously designed to amplify both the genomic DNA and the mRNA transcript from paraffin-embedded tissue. These products have predicted sizes of 250 BP and 154 BP, respectively, but our results showed that PCR amplification only (without reverse transcription) unexpectedly generated the 154-BP product. Further investigation of the nature of this product demonstrated that it originated from the amplification of DNA, not RNA. We conclude that the 154-BP product generated by these primers cannot be exclusively considered as beta-actin RNA product and should not be used to assess successful extraction of RNA, to ascertain its integrity, or to normalize for the total amount of RNA assayed by RT-PCR from paraffin-embedded tissue.

Actins↗

PubMed2005

Light microscopic identification and semiquantification of polyethylene particles in methylmethacrylate and paraffin-embedded experimental bone implant specimens.

The aim of this study was to evaluate the identification of polyethylene (PE) particles in relatively thick methylmethacrylate (MMA) sections widely used in bone implant research. The sensitivity and specificity were compared between decalcified paraffin-embedded oil red O (ORO) stained and MMA-embedded sections using polarized light. Furthermore, we introduced a grading system to semiquantify the level of PE particles in peri-implant tissue. Paraffin-embedded and MMA-embedded sections were compared concerning intra-observer agreement of the grading system. Moreover, the semiquantitative assessment of particle level was compared between the two section types. We found a sensitivity and specificity of polarized light of 100% for both paraffin ORO-stained and MMA sections. The intra-observer agreement on both types was comparable and acceptable. The ratings of differently processed blocks (MMA- and paraffin-embedded) originating from the same bone implant specimen showed good correlation. Our study showed that relatively thick MMA sections were just as suitable as ORO-stained paraffin sections concerning peri-implant PE particle migration analysis. MMA sections do not allow analysis at cellular level, but unbiased estimation of bone ingrowth into the implant surface based on stereological principles is possible.

Animals↗

PubMed1984

Freeze-dried paraffin-embedded human tissue for antigen labelling with monoclonal antibodies.

Conventional fixation and paraffin embedding of human tissue destroys most of the antigens detected with currently available antibodies, while cryostat sections give poor morphological detail and require freezer space for storage. However, when tissue was freeze-dried before being embedded in paraffin S then stained for a wide range of antigens recognised by monoclonal antibodies (including T-cell and B-cell antigens), morphological preservation was clearly better, and the labelling reactions were of equal (or greater) intensity, than with cryostat sections. As the number of diagnostically important monoclonal antibodies continues to increase the use of freeze-dried paraffin sections should facilitate the introduction of immunohistological techniques for both routine histopathological diagnostic work and immunological research.

Antibodies, Monoclonal↗

PubMed2001

Evaluation of T cell receptor testing in lymphoid neoplasms: results of a multicenter study of 29 extracted DNA and paraffin-embedded samples.

To evaluate current diagnostic methods used for the evaluation of T cell receptor (TCR) gene rearrangements, 24 different laboratories analyzed 29 lymphoid neoplasm samples of extracted DNA and paraffin-embedded tissue and were asked to complete a technical questionnaire related to the testing. Participating laboratories performed Southern blot and polymerase chain reaction (PCR) testing for rearrangements of the TCRbeta chain gene and PCR for the TCRgamma chain gene rearrangements. Of 14 laboratories performing TCRbeta Southern blot analysis, there was complete agreement in 10 of 14 cases, with some false negative results obtained in 4 cases. No false positive results were obtained by Southern blot analysis. TCRbeta PCR analysis was only performed by two laboratories, and only 47.1% of positive samples were detected. Twenty-one laboratory results were obtained for TCRgamma PCR. This method showed an overall detection rate of 77.9% for T cell gene rearrangements with a 4.1% false positive rate, as compared to both TCRgamma Southern blot analysis results and immunophenotyping. The detection rate for TCRgamma PCR, however, significantly differed when extracted DNA samples from frozen tissue were compared to paraffin-embedded tissue (85.4% versus 65.9%; P = 0.0005). Significant differences in true positive results were obtained when laboratories using primers directed against multiple TCRgamma variable regions (V1-8 plus one to three other primer sets) were compared to laboratories that used only a single set of TCR primers directed against the V1-8 (P < 0.0001). Other technical factors significantly affecting results were also identified. These findings provide useful data on the current state of diagnostic TCR testing, highlight the risk of false negative results for TCR testing directed against only portions of the TCRgamma gene, and identify limitations of testing of paraffin-embedded tissues in some laboratories.

Blotting, Southern↗

PubMed2003

Flow cytometric sorting of paraffin-embedded tumor tissues considerably improves molecular genetic analysis.

The characterization of genetic aberrations in paraffin-embedded tumor material is impaired by contaminating normal cells. In the present study on the genetic causes of loss of HLA expression in diffuse large B-cell lymphoma (DLBCL), we compared the efficacy of microdissection with flow cytometric sorting of tumor cells. Single-cell suspensions from paraffin-embedded material of 5 DLBCL cases were stained for CD79a and DNA content (propidium iodide). Fluorescent in situ hybridization (FISH) using HLA class II and chromosome 6 centromeric probes and loss of heterozygosity (LOH) analysis with 5 HLA-specific microsatellite markers were performed on microdissected and flow cytometry-sorted fractions. FISH confirmed considerable enrichment of the samples after flow cytometric sorting and disclosed tumor heterogeneity in 4 cases. Moreover, lymphomas with a so-called zebra LOH pattern in the microdissected material showed unambiguous LOH after flow cytometric sorting, revealing in 1 case a biologically relevant hemizygous deletion in the HLA region.

Chromosome Aberrations↗

PubMed1997

In situ DNA fragmentation assay for detection of apoptosis in paraffin-embedded tissue sections. Technical considerations.

Detection, by light microscopy, of cells in situ undergoing apoptosis has been improved by use of an in situ apoptosis (DNA fragmentation) assay on formalin-fixed and paraffin-embedded tissue sections. We studied conditions of tissue preparation and fixation that may affect the test results. In this study, we intended to determine whether archival tissues prepared under unknown conditions can be used for the in situ apoptosis assay. All tissue sections were pretreated with Proteinase K, followed by incubation with biotinylated 11-deoxyuridine triphosphate in terminal deoxynucleotidyl transferase and then avidin-biotin-peroxidase complex. The following formalin-fixed and paraffin-embedded histologic sections were tested: (1) normal tissues from surgically resected specimens fixed immediately or stored at 4 degrees C and then fixed after 1, 2, 4, 6, or 24 hours; (2) archival autopsy material from histologically normal tissues; and (3) freshly prepared normal tissues from C57 mice. We observed that fixation- and prefixation-elapsed times do not adversely affect the results of the assay. Similar, if not identical results were seen in archival human tissues stored for up to 25 years, the normal tissues freshly prepared from surgical specimens, and the tissues from C57 mice. We conclude that the in situ assay of DNA fragmentation is rapid, sensitive, and reproducible. The use of formalin-fixed and paraffin-embedded archival material as old as 25 years opens the way for a variety of studies of apoptosis in diverse pathologic states.

Animals↗

PubMed2003

A comparison of microwave heating and proteolytic pretreatment antigen retrieval techniques in formalin fixed, paraffin embedded tissues.

Antigen retrieval (AR) is a technique that re-exposes epitopes in formalin fixed, paraffin embedded sections and makes them detectable by immunohistochemistry. We compared the effects of two AR procedures, enzyme digestion and microwave heating, on immunostaining of vimentin and desmin in formalin fixed, paraffin embedded tissues. Our results showed that AR is necessary for vimentin and desmin immunostaining in tissues fixed in formalin for more than 48 h. With prolonged fixation times, microwave heating showed better results than enzyme digestion for AR. The same results were obtained using 1% zinc sulfate or Citra Plus solution as retrieval solutions for microwave heating. We recommend microwave heating for AR, because it is easier to use and produces better results compared to enzyme treatment.

Animals↗

PubMed2004

Fluorescence in situ hybridization on formalin-fixed and paraffin-embedded tissue: optimizing the method.

Fluorescence in situ hybridization (FISH) is widely used to study numerical and structural genetic abnormalities in both metaphase and interphase cells. The technique is based on the hybridization of labeled probes to complementary sequences in the DNA or RNA of the cells. Interphase FISH is most often applied on cytologic material such as hematologic smears or imprints, but the method is also used to study genetic changes in tissue sections when morphology is important or when cytologic material is not available. In cases in which the presence of intact nuclei is of importance, such as quantitation of signals as in triploidy, it is possible to isolate nuclei from paraffin-embedded tissue. However, using formalin-fixed paraffin-embedded tissue, either in thin sections or as isolated nuclei, one encounters a range of technical problems, paralleling those met in immunohistochemistry. Variations in time lapse between removal of tissue and fixation, duration of fixation, enzymatic pretreatment, hybridization conditions, and posthybridization washing conditions are important factors in the hybridization. In this study, we have listed the results of a systematic approach to improve FISH on isolated nuclei and tissue sections from formalin-fixed, paraffin-embedded tissue.

Chromosome Aberrations↗

PubMed1993

Management of lentigo maligna and lentigo maligna melanoma with paraffin-embedded tangential sections: utility of immunoperoxidase staining and supplemental vertical sections.

BACKGROUND: The use of frozen sections in the management of lentigo maligna and lentigo maligna melanoma has been the focus of some controversy. OBJECTIVE: Our purpose was to utilize paraffin-embedded tangential sections in the management of two cases of lentigo maligna and three cases of lentigo maligna melanoma. METHODS: A modification of Mohs micrographic surgery using rush paraffin-embedded sections with adjunctive immunoperoxidase staining (HMB-45) and supplemental vertical sections was employed. RESULTS: This method resulted in enhanced histologic evaluation of section margins and did not compromise the diagnosis of the primary invasive melanoma or Breslow measurements. CONCLUSION: Mohs micrographic surgery modified by the use of rush paraffin-embedded sections allows adjunctive immunoperoxidase staining and supplemental vertical sections that may be helpful in the management of lentigo maligna and lentigo maligna melanoma.

Aged↗

PubMed1995

Langerhans' cell histiocytosis. Definitive diagnosis with the use of monoclonal antibody O10 on routinely paraffin-embedded samples.

The histological and immunohistochemical findings of 34 biopsy specimens from patients with Langerhans' cell histiocytosis (LCH) are reported, with special emphasis on the findings with CD1a mouse monoclonal antibody (MAb) O10 using paraffin-embedded material. Eighteen patients were treated in an adult hospital (mean age, 26.3 years), and the 16 others were children (mean age, 3 years) from a pediatric center. Specimens included 17 bone, 14 skin, two lung, and one lymph node. Tissue was fixed in formalin or Bouin's, and most bone samples were decalcified in nitric acid. Frozen sections were available for 16 cases and electron microscopy for one. Light microscopy was suggestive of LCH in all cases, characterized by large mononucleated cells with abundant eosinophilic cytoplasm and "coffee bean" nucleus. In 33 of the 34 paraffin-embedded LCH samples, mononucleate cells were stained by MAb O10. As controls, we investigated seven tumors expressing S-100 protein (three nevi, two melanomas, two neurofibromas): all were negative with MAb O10. Five non-Langerhans' cell histiocytoses (three juvenile xanthogranulomas and two Rosai-Dorfman lymphadenopathies) were also negative with MAb O10. The results show that in most cases a definitive diagnosis of LCH can be assessed on paraffin-embedded tissue specimens with the help of immunohistochemistry using MAb O10.

Adult↗

PubMed1986

Detection of extracellular matrix antigens (fibronectin, laminin, type IV in collagen) in paraffin embedded sections by avidin-biotin-peroxidase complex labelling.

An avidin-biotin-peroxidase labelling method was applied to frozen sections and to routine-fixed, paraffin-embedded sections, and compared with immunohistochemical results of stromal antigen detection (type IV collagen, laminin and fibronectin) obtained in parallel on different neoplasias. Lung, breast and gastrointestinal tract tumors were studied. Superimposable sections were obtained from cryostat and formalin-fixed, paraffin-embedded specimens (previously digested by pepsin). The data demonstrate the potential use of immunohistochemical investigation of paraffin-embedded tissues for histological analyses of tumors.

Avidin↗

PubMed1990

Immunohistochemical detection of progesterone receptor in formalin-fixed and paraffin-embedded breast cancer tissue using a monoclonal antibody.

The potential for immunohistochemical detection of progesterone receptors (PRs) in routinely formalin-fixed and paraffin-embedded cancer tissues by use of the monoclonal antibody Mi 60-10 (mPR1, Dianova GmbH, Hamburg) was evaluated. The PR content of breast cancer tissue was investigated in 170 cases. A positive reaction to Mi 60-10 was found exclusively in the nuclei of benign or malignant epithelial cells. The distribution of PRs was heterogeneous. Immunohistochemical reaction was scored by multiplying the percentage of positive tumour cells by their prevalent degree of staining (Immunoreactive Score or IRS). The IRS values of formalin-fixed tissues (n = 170) were compared with those in snap frozen tissues (n = 82), with the PR content assayed by a DCC (dextran-coated charcoal) method (n = 170), with histopathological grading according to Bloom and Richardson and with the menopausal status of the patient. There was an acceptable ranked correlation (r = 0.74) between IRS in formalin-fixed and paraffin-embedded parts and snap frozen parts of the same carcinoma. A good correlation (r = 0.72) was also found, when the semiquantitative results of immunohistochemical PR detection in formalin-fixed and paraffin-embedded tissues were compared to PR concentrations measured by a DCC method in tumor cytosols. There was an 80% concordance between the two methods for qualitative discrimination of PR-negative and PR-positive carcinomas. IRS correlated significantly with the degree of histological differentiation of the tumors (P less than 0.001) but not with the menopausal status of the women (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

PubMed1992

Description of an in situ hybridization methodology for detection of Epstein-Barr virus RNA in paraffin-embedded tissues, with a survey of normal and neoplastic tissues.

The authors describe a highly sensitive and practical in situ hybridization method using an oligonucleotide probe for EBER1 RNA for the detection of Epstein-Barr virus (EBV) in formalin-fixed, paraffin-embedded tissue sections. Paraffin-embedded tissues from 793 cases of normal and neoplastic tissues were studied. Nuclear staining for EBV RNA was uniformly present in all or virtually all neoplastic cells in a variety of known EBV-positive tumors. We also demonstrate rare EBV-infected cells in normal lymphoid tissues. RNAase predigestion, competitive inhibition, and control probe studies confirmed the specificity of the staining. In addition, cross-reactivity of EBV RNA staining with other viruses was not present. Additionally, the distribution of EBV in a wide variety of other normal and neoplastic tissues is reported.

Base Sequence↗