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At least 937 records · Page 52Linked to original sources
PubMed2004

Detection of West Nile virus using formalin fixed paraffin embedded tissues in crows and horses: quantification of viral transcripts by real-time RT-PCR.

West Nile virus (WNV) RNA was quantified in WNV infected crows and horses with the help of a real-time reverse transcriptase-PCR assay. A 5' nuclease assay, based on NS5 gene detection with a fluorescent probe was used for quantifying WNV RNA using formalin fixed paraffin embedded tissue specimens. Quantitative detection of WNV RNA showed the presence of a higher amount of the viral RNA in crow tissues compared to equine tissues and these results correlated well with the detection of WNV antigen by immunostaining. In crows, the highest amount of virus was seen in the intestine and in horses in the brain.

Animals↗
PubMed2003

Detection of t(11;18)(q21;q21) in marginal zone lymphoma of mucosa-associated lymphocytic tissue type on paraffin-embedded tissue sections by using fluorescence in situ hybridization.

A chromosomal t(11;18)(q21;q21) recurrently found in marginal zone lymphomas of mucosa-associated lymphocytic tissue (MALT) type is one of the key determinants of their treatment and outcome because t(11;18)-positive cases are resistant to Helicobacter pylori eradication therapy. To detect t(11;18) on paraffin-embedded tissue sections, we established a method of dual-color fluorescence in situ hybridization (D-FISH) using DNA probes directly labeled with SpectrumGreen and SpectrumOrange (tissue-FISH [T-FISH]). T-FISH detected the t(11;18) as colocalized signals between the band-specific yeast artificial chromosome (YAC) clones y966e4 (11q21) and y943b8 (18q21) on the der(11)t(11;18). The t(11;18) was detected in four of 22 patients with marginal zone lymphoma of MALT type in 72%-78% of the cells. In both patients studied, the percentage of t(11;18)-positive cells was much higher in tissue-FISH analysis than in interphase-FISH: 74% versus 30% in patient 1 and 75% versus 31% in patient 4. None of the 12 patients with diffuse large B-cell lymphoma of the stomach showed the t(11;18). Tissue-FISH is a powerful tool for the diagnosis of marginal zone lymphoma of MALT type because it can be applied not only to small specimens obtained from endoscopic biopsy samples but also to archival materials, hence facilitating the delineation of subtypes in marginal zone lymphoma of MALT type.

Adult↗
PubMed2001

Genotyping of Helicobacter pylori strains in formalin-fixed or Formaldehyde-sublimate-fixed paraffin-embedded gastric biopsy specimens.

Different genotypes of Helicobacter pylori can play a role in the development of atrophic gastritis, peptic ulcer disease, and gastric carcinomas. In this study the authors developed polymerase chain reaction assays for the detection and identification of vacA (s- and m-regions), cagA, and iceA genotypes of H. pylori in formalin-fixed or formaldehyde-sublimate-fixed paraffin-embedded gastric biopsy specimens. Polymerase chain reaction products were analyzed by reverse hybridization on a line-probe assay. Complete genotyping was achieved in 26 of 28 samples (93%), and multiple genotypes, indicating the presence of multiple strains, were detected in nine samples (32%). This genotyping method offers the possibility for long-term retrospective studies on H. pylori genotypes and gastric pathology in the same archival gastric tissue specimens.

Bacterial Proteins↗
PubMed2004

Advances in the detection of prion protein in peripheral tissues of variant Creutzfeldt-Jakob disease patients using paraffin-embedded tissue blotting.

The accumulation of PrP(Sc), an abnormal and disease-associated form of the normal prion protein (PrP(c)), within the central nervous system (CNS) is a key pathological feature of Creutzfeldt-Jakob disease (CJD). Following limited proteolytic digestion of PrP(Sc), the detection of PrP(res) within lymphoid tissues is a unique characteristic of variant CJD in comparison with other human prion diseases, raising fears of an increased risk of iatrogenic spread. Because levels of PrP(res) in lymphoid tissues are lower than those found in CNS tissue, there is concern that other peripheral tissues may harbour infectivity at levels that current detection systems cannot demonstrate PrP(res). We have modified the paraffin-embedded tissue blot (PET blot), a technique combining immunohistochemistry (IHC), histoblot and Western blotting, for the detection of PrP(res) in paraffin sections in peripheral tissues in variant CJD. Five cases of variant CJD were examined, using a panel of anti-PrP antibodies. In each of these five cases, spleen, tonsil, lymph nodes and dorsal root ganglia showed an increase in the sensitivity and specificity of labelling using the PET blot when compared with optimized PrP(res) IHC methods. Control cases showed no evidence of PrP accumulation in either peripheral or CNS tissues. Autopsy and biopsy brain material from sporadic CJD cases also showed an increased sensitivity of PrP(res) detection with the PET blot, confirming its value as an important diagnostic and research tool in human prion diseases.

Adolescent↗
PubMed1978

A reliable method for electron microscopic examination of specific areas from paraffin-embedded tissue mounted on glass slides.

A reliable method for electron microscopic examination of specific areas from paraffin-embedded tissue mounted on glass slides. Am J Clin Pathol 70: 697--699, 1978. A method to embed and cut tissue mounted on ordinary glass histologic preparations for electron microscopic observations is described. The cover slip is removed by immersing the slide in xylene for a few minutes to several hours. After the cover slip is removed, the tissue is fixed in osmium tetroxide, dehydrated, and embedded in epoxy resins by inverting a BEEM capsule filled with the resin on a selected area of the slide. After polymerization, thin sections are obtained and observed with the electron microscope with good results.

Histological Techniques↗
PubMed1989

Immunohistochemical detection of feline calicivirus in formalin-fixed, paraffin-embedded specimens.

An immunohistochemical technique was developed for detection of feline calicivirus (FCV) in formalin-fixed, paraffin-embedded cultured cells and tissues. Initial trials with cultured cells indicated that the indirect immunoperoxidase method using rabbit antiserum to FCV strain 255, and horseradish peroxidase-labelled antibodies to rabbit immunoglobulin G lacked sensitivity and showed excessive diffuse background staining despite trypsin digestion of sections before staining. An amplified indirect immunoperoxidase technique using commercially available biotinylated antirabbit antibodies and avidin-biotin-peroxidase or streptavidin-peroxidase (SP) complexes proved highly successful. When optimal conditions, including those for trypsinization, inactivation of endogenous peroxidase and blocking were determined, the SP technique was preferred. Applied to tissue of cats in the acute phase of FCV infection, the technique provided clear identification of cells containing FCV antigens in sections in which histological detail was well preserved.

Animals↗
PubMed1987

Astrocytes in the prenatal central nervous system. From 5th to 28th week of gestation. An immunohistochemical study on paraffin-embedded material.

The CNS from 30 normal fetuses aged 5-28 weeks were studied in GFAP stained paraffin-embedded material. The technique of preparation, autopsy and fixation is described in details. GFAP reacting glial cells developed first in the spinal cord at 7 weeks, and appeared in all regions of CNS during fetal life in a systematic way but with a temporal variation. The supporting and guiding properties of the fibrillary astrocytes are stressed.

Astrocytes↗
PubMed1997

Reactivity of antibody YU-311 in formalin-fixed, paraffin-embedded specimens of normal organs, non-hematopoietic tumors, and mast cell tumors.

YU-311 is a monoclonal antibody that reacts with a human leukemia cell line resistant for cytosine arabinoside and that identifies a 92 kDa membrane protein. The reactivity of YU-311 in normal organs, various non-hematopoietic tumors and in mast cell tumors in formalin-fixed, paraffin-embedded specimens was examined using immunohistochemical methods. In normal organs, YU-311 reacted with fundic glands of the stomach, the intercalated duct of the pancreas, the distal portion and the loop of Henle of renal tubules and tissue mast cells. Benign neoplasms of various organs showed no immunoreaction with YU-311, except for mast cell tumors. Some types of malignant neoplasms were occasionally positive against YU-311, suggesting neoplasms arising from or differentiating along normal YU-311-positive counterparts. Some other types of malignancies were rarely positive for YU-311, although their normal counterparts showed no immunoreactivity with YU-311. None of the non-epithelial tumors reacted with YU-311, except for one case of malignant melanoma. In contrast, normal tissue mast cells and their related tumors, such as urticaria pigmentosa or solitary mastocytoma, were constantly positive for YU-311. None of the non-hematopoietic human tumor cell lines examined in the present study was reactive with YU-311. These findings indicate that YU-311 is a good marker of some types of tumors and mast cell tumors and that an aberrant expression of YU-311 rarely occurs.

Adenoma↗
PubMed1983

Immunofluorescence microscopy of paraffin-embedded human kidney specimens obtained by fine-needle aspiration biopsy.

Recently, we have introduced an atraumatic fine-needle aspiration biopsy method to obtain human glomeruli for morphologic investigation. In the present study, immunofluorescence microscopy of paraffin-embedded, fine-needle specimens is described. The specimens were obtained by aspiration with a 10-mL syringe fitted to the fine-needle prepared from a lumbar puncture needle (Jintan Terumo). Embedding of the specimens into conventional paraffin blocks was carried out after pelleting them by centrifugation between processing steps in conical centrifuge tubes. Sections from the blocks were collected on small pieces of GelBond film (FMC Corporation) instead of objective slides, which prevented the detachment of small sections during enzyme treatment. Localization then was performed on deparaffinized trypsin-digested sections using fluorescein-labeled antibodies. The choice of fixative and digestive enzymes was found to have a marked effect on the localization; periodate-lysine-paraformaldehyde fixative and trypsin digestion gave the most reliable results.

Biopsy, Needle↗
PubMed1997

[Standardization of immunohistochemical techniques for detecting dengue virus antigens in paraffin-embedded tissues].

The immunohistochemical techniques may be very useful for the detection of antigens of the dengue virus in infected tissues. The results obtained with the use of 2 IHC methods: one direct and another indirect amplified with a biotin universal antibody and a streptavidin peroxidase system (LSAB) (the peroxidase enzyme is used in both) are shown in this paper. These methods were applied on paraffin-embedded tissues from mice that were inoculated with the dengue virus intracerebrally. Our objective is to have a technique at the laboratory allowing to identify these antigens in the tissues in order to apply them on the diagnosis and on the studies connected with the obtention of immunogens.

3,3'-Diaminobenzidine↗
PubMed1993

Analysis of the Gs alpha gene in growth hormone-secreting pituitary adenomas by the polymerase chain reaction-direct sequencing method using paraffin-embedded tissues.

We investigated the prevalence of Gs alpha gene mutations in growth hormone (GH) secreting pituitary adenomas from Japanese patients with acromegaly. Forty-five GH-secreting adenomas were examined for the presence of point mutations in codons 201 or 227 of the Gs alpha gene using the polymerase chain reaction-direct sequencing method and deoxyribonucleic acid extracted from paraffin-embedded tumor specimens. Mutation of codon 227 of the Gs alpha gene was not observed in any of the tumors, but a mis-sense mutation of codon 201 was identified in two tumors (4.4%). One lesion was a densely granulated GH cell adenoma in a patient with adenomatous goiter and breast cancer. The other was a mixed GH cell-prolactin cell adenoma in a patient with multiple endocrine neoplasia type 1 associated with parathyroid hyperplasia and a pancreatic islet cell tumor. The Gs alpha gene detected in parathyroid tissue and pancreatic tumor tissue was of the wild type in this second patient, and the mutation was specific to the pituitary tumor. These results suggest that point mutations of codons 201 or 227 of the Gs alpha gene may not be important mediators of oncogenesis for GH-secreting pituitary adenomas in Japan.

Adenoma↗
PubMed2005

p53 alterations in sequential biopsies of Asian follicular lymphoma: a study of immunohistochemical staining pattern and gene mutations by PCR-SSCP in paraffin-embedded tissues.

AIM: Tumour suppressor gene p53 is a common target in carcinogenesis, reported to be altered and functionally inactive in 70% of human cancers. Although p53 mutations are less commonly present in haematological malignancies when compared with other solid tumours, they have been reported in histological transformation of follicular lymphoma. We aimed to investigate the frequency of p53 gene alterations in paraffin-embedded tissue using commercially available PCR-SSCP, and to correlate the results with P53 protein expression by immunohistochemistry. METHODS: Surgical samples from seven patients with a total of 17 sequential biopsies were retrieved for the study of p53 gene expression using immunohistochemical stain, and gene status by PCR-SSCP for exons 5-8. The tumours were graded according to the WHO classification criteria. P53 was distinctly over-expressed in five transformed higher grade biopsies, and all except one showed electrophoretic mobility shift in PCR-SSCP analysis. Sequencing analysis revealed single nucleotide substitutions in three of four of these high-grade transformed cases with band shift (75%), whereas some other studies reported a lower frequency of 25-30%, and mobility shift result was found to correlate with P53 expression. Lower grade tumours without P53 over-expression did not demonstrate band shift, and sequencing analysis did not reveal mutations. CONCLUSIONS: We demonstrated the feasibility of adopting PCR-SSCP for screening of p53 mutations in archival tissue samples in this study, and there is a strong correlation of p53 gene over-expression and mutation events in high-grade transformed tumours.

Adult↗
PubMed2002

Immunohistochemical detection of progesterone receptors and the correlation with Ki-67 labeling indices in paraffin-embedded sections of meningiomas.

Female sex steroids may play a role in the proliferation of meningiomas, which usually have a high level of progesterone receptors (PgRs). We aimed to investigate the presence of PgRs and the Ki-67 labeling index (Ki-67 LI) in meningioma cases (N = 110) in relation to the severity of the disease. We studied PgR immunoreactivities and the Ki-67 LI in paraffin-embedded sections from meningiomas. Immunodetection of PgRs was conducted with peroxidase-antiperoxidase complex. Immunodetection of Ki-67 antigen was achieved by streptavidin-biotinperoxidase complex. Of 110 meningiomas, in 57 (52%) the immunostaining for PgRs was moderately to strongly positive (Group 1), in 23 (20%) weakly positive (Group 2), and in 30 (28%) negative (Group 3). The positive immunostaining rate for the PgR in the benign meningiomas (76%) was significantly higher than that in nonbenign tumors. The positive immunostaining rate for the PgR was significantly higher in women (81%) than men (55%). The results suggested that progesterone may play a role in the growth of meningiomas. Our results confirmed that the immunodetection of the PgR and Ki-67 antigens on the paraffin sections of meningiomas provides a valuable tool for estimating the biological behavior of meningiomas.

Adolescent↗
PubMed1999

Comparison of different double immunostaining protocols for paraffin embedded liver tissue.

Most of the double immunostaining protocols that have been introduced so far have been developed for application on fresh frozen material or based on different species antibodies. In liver tissue, general problems of double immunostaining techniques are further complicated by tissue-specific difficulties, such as necrosis or high intracellular protein content. To assess a reliable double immunostaining protocol for archived, paraffin embedded liver tissue, different protocols based on the use of same species primary antibodies were evaluated in terms of sensitivity, specificity and non-specific background staining in pathological liver specimens. We compared peroxidase-anti-peroxidase, alkaline phosphatase-anti-alkaline phosphatase (PAP/APAP), labelled-avidin-biotin (LAB/LAB) and digoxigenin-anti-digoxigenin (dig-a-dig/PAP) techniques using different cytokeratin antibodies and an antibody against PCNA. Comparison of the double immunostaining techniques revealed a high sensitivity and specificity in all procedures. Sections, which were stained employing PAP/APAP-technique, displayed a higher background staining compared to sections which were treated with the LAB/LAB or dig-a-dig/PAP protocol. In contrast to the dig-a-dig/PAP protocol, the LAB/LAB technique provides a better time/cost relationship. Therefore, we would like to recommend a modified LAB/LAB protocol for simultaneous detection of different antigens in archived liver tissue.

Animals↗
PubMed2005

Nucleolar organizer region staining patterns in paraffin-embedded tissue cells from human skin cancers.

BACKGROUND: Increased number of nucleoli (nucleolar organizer regions, NORs) with abnormal shapes and sizes, including small dots, has been used as prognostic tools to evaluate tumor proliferation levels and troublesome borderline lesions. In this study, NOR patterns of skin cancers were performed in the search of a valuable prognostic method to complement other histological procedures. METHODS: Paraffin-embedded tumor tissue was obtained from basal and squamous cell carcinomas, cutaneous malignant melanoma, premalignant lesions, and Skmel-28 human melanoma cells. Slices were dewaxed and AgNOR stained. The patterns were scored and submitted for statistical analyses. RESULTS: All types of cancer cells showed variable numbers of abnormally shaped nucleoli and dot-like structures. Only tumor cells presented four or more nucleoli, with or without dots, while 85% of the normal cells had one single NOR without dots. Most data were statistically significant when compared to normal cells. As a whole, squamous cell carcinoma and malignant melanoma tumor cells had less NOR alterations than basal cell carcinoma (BCC) tumor types. CONCLUSIONS: Changes in the number and shape of nucleoli present in malignant cells could be attributed to increased levels on rDNA transcription on cancer cells, besides abnormal remodeling of chromatin, which could disrupt proper nucleoli association. Increased genetic alterations on malignant basal cells could contribute to impair invasive and migration abilities of BCC tumors.

Basal Cell Carcinoma↗
PubMed2005

Paraffin-embedded cell line microarray (PECLIMA): development and validation of a high-throughput method for antigen profiling of cell lines.

The introduction of high-throughput techniques is increasingly providing abundant information on molecular alterations requiring validation at the posttranscriptional level. Protein expression is now efficiently evaluated in large series of tumors included in tissue microarrays. We propose, describe and validate a technique to elaborate paraffin-embedded cell line microarrays (PECLIMA) from fixed cell cultures, which can be processed like standard surgical pathology biopsies prior to immunophenotyping. Our results show a reliable protein immunoexpression profiling in six widely used cell lines under different fixation conditions. This technique permits the simultaneous analysis of multiple antigens in multiple cell lines under different experimental conditions. Additional features of these arrays are long-term storage, their suitability for a variety of techniques including immunocytochemistry and in situ hybridization and their low cost.

Antigens, Neoplasm↗