PubMed Health⌕ Search

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 631 records · Page 35Linked to original sources
PubMed1997

Evaluation of a fluorescence-labelled oligonucleotide probe targeting 23S rRNA for in situ detection of Salmonella serovars in paraffin-embedded tissue sections and their rapid identification in bacterial smears.

A method for the detection of Salmonella based on fluorescence in situ hybridization (FISH) has been developed and applied for the direct detection of Salmonella in pure cultures and in formalin-fixed, paraffin-embedded tissue sections. On the basis of the 23S rRNA gene sequences representing all of the S. enterica subspecies and S. bongori, an 18-mer oligonucleotide probe was selected. The specificity of the probe was tested by in situ hybridization to bacterial cell smears of pure cultures. Forty-nine of 55 tested Salmonella serovars belonging to subspecies I, II, IIIb, IV, and VI hybridized with the probe. The probe did not hybridize to serovars from subspecies IIIa (S. arizonae) or to S. bongori. No cross-reaction to 64 other strains of the family Enterobacteriaceae or 18 other bacterial strains outside this family was observed. The probe was tested with sections of formalin-fixed, paraffin-embedded tissue from experimentally infected mice or from animals with a history of clinical salmonellosis. In these tissue sections the probe hybridized specifically to Salmonella serovars, allowing for the detection of single bacterial cells. The development of a fluorescence-labelled specific oligonucleotide probe makes the FISH technique a promising tool for the rapid identification of S. enterica in bacterial smears, as well as for the detection of S. enterica in histological tissue sections.

Animals↗
PubMed1998

Detection of EB Virus Gene Fragments in Paraffin-embedded NPC Tissue.

To detect more sensibly Epstein-Barr virus (EBV) DNase gene fragments in nasopharyngeal carcinoma (NPC) tissue, a pair of optimized primers flanking 29% of EBV-DNase gene were designed. PCR results showed that EBV-DNase gene was detected in 145 of 149(97.32%) paraffin-embedded tissue samples with NPC and 2 of 155 (1.29%) cases in high risk population. DNA sequencing proved that DNA sequence of the PCR product agreed with BGLF5 reading frame from Genbank VO1555. Paraffin-embedded NPC samples stored for less than 1.5 years under room temperature and atmosphere conditions in South China were suitable for PCR detection.

Journal Article↗
PubMed1994

Morphological detection of X- and Y-chromosomes in smears and paraffin-embedded tissues using a non-isotopic in situ hybridization technique (NISH).

Pharyngeal smears and paraffin-embedded tissue specimens (skeletal muscle, kidney) obtained from 10 male and 10 female individuals were evaluated using non-isotopic in situ hybridization (NISH) with commercial X- and Y-specific biotinylated probes which recognize the pericentromeric regions DXZ1 and DYZ1/DYZ3 of the X- and Y-chromosome, respectively. The results provide evidence that the morphological sex determination of a single cell can be performed by critical application of this staining method leading to one nuclear signal in "male" cells using the Y-specific probe whereas "female" cells are negative. In situ hybridization of "female" tissues with an X-specific probe results regularly in 2 signals whereas "male" cells show only one spot in the nucleus.

Adult↗
PubMed2002

[Alterations of DPC4/SMAD4/MADH4 gene detected in paraffin-embedded tissues of human pancreatic carcinomas].

OBJECTIVE: To demonstrate the alterations of DPC4/SMAD4/MADH4 gene in paraffin-embedded tissues of pancreatic carcinomas. METHODS: Forty-six cases of resected specimens containing carcinomatous tissue and normal pancreatic tissue were analysed for possible DPC4 gene mutations by polymerase chain reaction (PCR)and single-strand conformation polymorphism (SSCP). The DNA sequencing technique was applied to determine the patterns of gene mutation in the PCR-SSCP positive cases. Fifty-six cases of pancreatic carcinoma along with the specimens corresponding normal pancreatic tissues were studied by in situ hybridization (ISH) and immunohistochemistry (IHC) techniques for gene expression in mRNA and protein level. RESULTS: The homozygous deletion rate of exon 1, 2, 3, 4, 8, 11 of DPC4 gene in pancreatic carcinoma was 28.26%, while the mutation rate of DPC4 gene was 21.74%. In these tumors, there were 3 cases of nonsense mutation, 5 cases of missense mutation, 1 case of deletion and missense mutation, 1 case of insertion mutation. Positive rates of SMAD4 in carcinomatous tissues detected by the ISH and IHC were 53.57% and 58.93% respectively, whereas they were 91.07% and 89.29% in the matched normal tissue respectively. There were significant difference between cancer and normal tissue (P < 0.05). Thrity-two cases were positive of DPC4/SMAD4 with all methods mentioned above, the coincident rate was 87.50% (28/32). The coincidence between gene detection and ISH of SMAD4 was 87.50%, and it was 96.88% between gene detection and IHC of SMAD4. Of all 56 cases, the coincidence of the positive rates of SMAD4 detected by ISH and IHC was 91.07%. No significant difference among the positive rates of DPC4/SMAD4 as detected by the three different techniques (P > 0.05). CONCLUSIONS: The main mechanisms of inactivation of DPC4 gene in pancreatic carcinoma are homozygous deletion and mutation. The product of DPC4 expression is significantly decreased in cancer group compared with the normal tissues. As a tumor suppressor gene, DPC4 alteration is an important molecular event in pancreatic carcinoma, and probably plays a crucial role in cancer development and progression.

Adult↗
PubMedDate not supplied

Polymerase chain reaction screening for DNA viruses in paraffin-embedded brains from dogs with necrotizing meningoencephalitis, necrotizing leukoencephalitis, and granulomatous meningoencephalitis.

The objective of this investigation was to determine whether or not herpesvirus (herpes-), adenovirus (adeno-), or canine parvovirus DNA is present in the brains of dogs with necrotizing meningoencephalitis (NME), necrotizing leukoencephalitis (NLE), and granulomatous meningoencephalitis (GME). Paraffin-embedded brain specimens from 12 histopathologically confirmed dogs with NME, 3 with NLE, and 7 with GME were screened for viral DNA with degenerate herpes- and adenovirus polymerase chain reaction (PCR) and a canine parvovirus-specific PCR. Positive-control specimens included genomic viral DNA and paraffin-embedded tissues from dogs with confirmed herpes-, adeno-, or canine parvovirus infections. Herpes-, adeno-, or canine parvovirus DNA was amplified by PCR from the corresponding positive-control specimens. Negative controls included 7 dogs with various brain disorders and produced no viral amplicons. The 22 dogs with NME, NLE, and GME were negative for viral DNA. Additional studies testing for other viruses or inherited genetic mutations are warranted to gain insight into the etiologies of NME, NLE, and GME. We discuss potential etiologies and provide a clinical and histopathologic overview of these common canine encephalitides.

Animals↗
PubMed1988

Routine diagnostic immunohistochemical labeling of extracellular antigens in formol saline solution-fixed, paraffin-embedded cutaneous tissue.

A technique involving modification of the routine paraffin embedding procedure that allows immunohistochemical examination of extracellular antigens by light microscopy is described. The method is thus suitable for routine diagnostic immunofluorescence studies, permitting reliable, reproducible immunolabeling of immunoglobulins and complement components usually not preserved by routine processing procedures. Immunoreactivity as measured by direct immunofluorescence and immunoenzymatic (peroxidase-antiperoxidase) histochemistry is comparable to results with fresh-frozen cryostat sections. Morphologic preservation is superior, however, and the processed material is suitable for routine hematoxylin-eosin staining.

Antigens, Surface↗
PubMed1992

The monoclonal antibody (MAB) CD 68 allows the immunocytochemical identification of macrophages in primary and metastatic brain tumors in paraffin embedded tissues.

While using the MAB CD 68 applied to paraffin embedded tissue specimen, macrophages could be marked in 31 primary brain tumors of glial origin and in 17 metastatic tumors from which 7 were carcinomas of the lung, 5 carcinomas of the breast, 2 from the digestive tract and 3 were clear cell carcinomas of the kidney. Despite quantitative differences between the primary and metastatic tumors in all specimen examined macrophages were found. The macrophages were localized within the tumor tissue, at the periphery of the tumor and its surroundings. In some cases cells with an intensive staining reactions were visible in blood vessel walls. No correlation between the type of tumor and intensity of macrophages infiltration has been found, however there were quantitative differences between primary and metastatic tumors.

Adenocarcinoma↗
PubMed1990

Modified methodology to improve flow cytometric DNA histograms from paraffin-embedded material.

Flow Cytometric (FCM) DNA content analysis of paraffin-embedded tissues has become a widely accepted procedure in assessing the biologic course in some tumors from archival material. Difficulty in interpreting histograms is frequently due to high levels of debris, and wide coefficients of variation (CV). These may lead to underestimating near-diploid abnormality. Although the clinical significance of low-degree aneuploidy has yet to be established, the procedure reported here improved our endeavor to detect DNA Indices (DI) of at least 1.1%. Experience has shown that careful technique can result in overall improvement of DNA histograms by lowering levels of debris and % CV, dramatically so in some cases. Archival histograms can be generated that rival in quality fresh tissue results. Archival material is currently employed for diagnostic and research purposes.

DNA, Neoplasm↗
PubMed1989

Flow cytometric measurements of DNA index and S-phase on paraffin-embedded early stage endometrial cancer: an important prognostic indicator.

Paraffin-embedded curettage material from 120 patients with stage I and II endometrial cancer were analyzed by flow cytometry. The follow-up time in all cases was at least 5 years or until death. It was possible to determine DNA ploidy in 111 cases and S-phase was also evaluated in 92/111 cases. DNA ploidy and S-phase were then compared with the FIGO grading and clinical outcome. DNA ploidy results showed that 11% of grade 1 tumors were aneuploid, 14% of grade 2, 42% of grade 3, and 85% of the cases of uterine papillary serous carcinoma (UPSC) were aneuploid. Patients with tumors that showed an S-phase fraction below 5% had a cumulative 5-year cancer mortality of 7% whereas 49% of the patients with tumors having S-phase fraction above 10% died of their cancer. The prognostic significance of DNA and S-phase correlated fairly well with the FIGO grading as determined by a pathologist with special interest in gynecologic oncology and the DNA parameters added prognostic information independent of the FIGO grading.

Aged↗
PubMed1984

The influence of formalin and paraffin embedding on the immunohistochemical reaction of monoclonal antibodies applied to female breast tissue.

Monoclonal antibodies, raised against purified human milk fat globule membranes, were applied to human tissue and the corresponding antigenic determinants detected by an immunoperoxidase method. In human breast tissue, the presence of antigenic determinants was characterized by considerable heterogeneity although it is confined to epithelial cells and cannot be detected in non-epithelial areas. The effect of fixation and paraffin embedding on the reaction pattern was evaluated on tissue from 25 primary breast carcinomas. For each tumor, both frozen, acetone fixed and fixed, paraffin embedded tissue was available. Four of the eight applied antibodies could detect fewer positive cells in formalin-fixed tissue as compared to frozen, acetone-fixed tissue from the same tumor. The positive peroxidase reaction was better preserved after fixation in Lillie's solution. Treatment of formalin-fixed tissue with pronase did not give a better effect. Antibodies with preserved positive reaction in formalin-fixed breast tissue were applied to a range of epithelial and non-epithelial human malignant tumors of varying origin. A heterogeneous positive reaction could be detected in the majority of tumors derived from epithelial cells, but not in non-epithelial tumors.

Antibodies, Monoclonal↗
PubMed1980

The detection of islet-cell antibodies by immunofluorescence in Bouin's-fixed, paraffin-embedded human pancreas.

Pancreatic islet-cell antibodies have been demonstrated in the sera of insulin-dependent diabetic patients, with or without polyendocrine disease, by immunofluorescent microscopy in which cryostat sections of fresh-frozen human pancreas were used as the substrate. In the present study we used sections of Bouin's-fixed, paraffin-embedded, trypsin-treated human pancreas as the islet-cell substrate and compared the results to those obtained with cryostat sections. Twenty-four sera from insulin-dependent diabetic patients, one serum from a non-insulin dependent diabetic patient and five sera from normal individuals were tested. With serum samples containing islet- cell antibodies, Bouin's-fixed, paraffin-embedded tissue produced a more intense fluorescence, was easier to use and was more sensitive than the conventional cryostat method.

Acetates↗
PubMed1976

Sex chromatin determination in formalin-fixed, paraffin-embedded tissues of rats.

Distinctive chromatin bodies appearing in interphase nuclei of mammalian female cells have been found in most mammalian species. The positive correlation between sex chromatin masses and mammalian female tissue presents an almost ideal criterion for sex determination of mammalian tissues. Previous studies indicate that this positive correlation exists in fresh and formalin-fixed, paraffin-embedded normal and tumor tissue of humans, as well as in fresh squash preparations of normal and tumor tissues of rodents. In this experiment we have shown that it is also possible to determine sex in formalin-fixed, paraffin-embedded normal and tumor tissue of the rat.

Adenocarcinoma↗
PubMed1991

Differential diagnosis of cutaneous large cell lymphomas using monoclonal antibodies reactive in paraffin-embedded skin biopsy specimens.

We studied a large panel of monoclonal antibodies reactive on routinely processed paraffin-embedded tissue to determine their sensitivity and specificity in the diagnosis of 35 primary cutaneous large cell lymphomas of B- (n = 14) and T-cell origin (n = 21). The findings show that differentiation between clinically relevant subgroups can be obtained by a small panel of antibodies including L26, MB2, LN1, MT1, UCHL1, and Ber-H2. Pitfalls in the use of the reagents are discussed.

Antibodies, Monoclonal↗
PubMed2001

Comparison of the DNA extraction methods for polymerase chain reaction amplification from formalin-fixed and paraffin-embedded tissues.

To obtain an adequate quality and quantity of DNA from formalin-fixed and paraffin-embedded tissue, six different DNA extraction methods were compared. Four methods used deparaffinization by xylene followed by proteinase K digestion and phenol-chloroform extraction. The temperature of the different steps was changed to obtain higher yields and improved quality of extracted DNA. The remaining two methods used microwave heating for deparaffinization. The best DNA extraction method consisted of deparaffinization by microwave irradiation, protein digestion with proteinase K at 48 degrees C overnight, and no further purification steps. By this method, the highest DNA yield was obtained and the amplification of a 989-base pair beta-globin gene fragment was achieved. Furthermore, DNA extracted by means of this procedure from five gastric carcinomas was successfully used for single strand conformation polymorphism and direct sequencing assays of the beta-catenin gene. Because the microwave-based DNA extraction method presented here is simple, has a lower contamination risk, and results in a higher yield of DNA compared with the ordinary organic chemical reagent-based extraction method, it is considered applicable to various clinical and basic fields.

DNA Primers↗
PubMed2001

An immunohistochemical method that differentiates Cryptococcus neoformans varieties and serotypes in formalin-fixed paraffin-embedded tissues.

An immunohistochemical method for determining the variety of Cryptococcus neoformans in formalin-fixed paraffin-embedded tissues was developed using mAbs 471, 302 and CRND8. The method was validated primarily using veterinary patients for which both formalin-fixed lesions and a cultured isolate were available. L-Canavanine glycine bromothymol blue (CGB) agar and the 'Crypto-Check' kit were used to determine the variety and serotype, respectively, of cultured isolates. Immunohistochemistry accurately predicted the C. neoformans variety in all tissue specimens. The CGB agar method of determining C. neoformans variety gave the same result as immunohistochemistry for 30/31 specimens. For the single discordant isolate, the serotype, random amplification of polymorphic DNA profile, microscopic and colony morphology all supported the immunohistochemical staining pattern in suggesting C. neoformans var. gattii; however, the CGB agar result was at variance. Of the C. neoformans var. neoformans cases, immunohistochemistry was congruent with variety for 13/13 cases and with serotyping for 10/13 cases. The three discordant cases were classified as having some serotype D reactivity by immunohistochemistry, but were considered to be serotype A using the Crypto-Check kit. This new method should prove a valuable epidemiological tool in studies of cryptococcosis, especially in the veterinary setting where archival tissue specimens may exist but corresponding mycological data is typically absent. The versatility of this method will expand in the future as other monoclonal antibodies with different specificities are developed.

Antibodies, Monoclonal↗
PubMed2001

HOPE fixation: a novel fixing method and paraffin-embedding technique for human soft tissues.

We have developed a novel method for tissue fixation, including subsequent paraffin-embedding and sectioning, that allows the complete pathological analysis of all types of human soft tissues. Furthermore, it maintains additional positive features relevant to immunohistochemistry and molecular pathology. The so-called HOPE-technique (Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect) comprises a protection-solution with an organic buffer, acetone as the only dehydrating agent, and pure paraffin of 52-54 degrees C melting temperature. Although the exact mechanism of protection has still to be elucidated, it seems rather unlikely that chemical bindings occur during the whole process of fixation, which is described and compared with the standard formalin-paraffin technique. Essentially, HOPE-fixed sections show formalin-like morphology. However, the sections are somewhat difficult to handle because of their fragility. This is due to the absence of any type of protein cross-linking and the dynamic processes of immersion and outflow of the HOPE protection solution. HOPE-fixed sections provide an excellent preservation of proteins and antigenic structures for differential analysis by immunohistochemical and/or enzyme histochemical techniques. However, their most remarkable feature is the extremely low degradation of nucleic acids (DNA and RNA) combined with good results obtained by in situ hybridization techniques. In conclusion, HOPE fixation may become a valuable additional tool in modern pathology.

Cross-Linking Reagents↗
PubMed2006

Molecular detection of FUS-CREB3L2 fusion transcripts in low-grade fibromyxoid sarcoma using formalin-fixed, paraffin-embedded tissue specimens.

A diagnosis of low-grade fibromyxoid sarcoma (LGFMS) remains problematic because of its bland-looking histologic features that can be potentially confused with other benign or low-grade fibromyxoid lesions. Recent cytogenetic and molecular analyses have shown that most LGFMSs have a characteristic chromosomal abnormality, t(7;16)(q33;p11), resulting in the FUS-CREB3L2 fusion gene. However, such assays have only rarely been used to analyze formalin-fixed, paraffin-embedded tumor samples. In the present study, we conducted a reverse transcription-polymerase chain reaction assay to detect the FUS-CREB3L2 fusion transcripts using formalin-fixed, paraffin-embedded tumor tissue specimens from 16 LGFMSs including 3 cases with giant collagen rosettes. The primers were newly designed to specifically amplify most of the junctional regions of the FUS-CREB3L2 fusion gene transcripts previously reported. The FUS-CREB3L2 fusion gene transcripts were detected in 14/16 (88%) cases of LGFMS. A nucleotide sequence analysis of the PCR products revealed that different portions of the FUS exon 6 or 7 were fused with various sites of the CREB3L2 exon 5, resulting in 12 different nucleotide sequences. We also tested a primer set to detect the FUS-CREB3L1 fusion transcript, which is a rare variant of the gene fusion in LGFMS, although no PCR products were identified in any case. The FUS-CREB3L2 fusion transcripts were not detected in any of the 123 other soft-tissue tumors, including desmoid-type fibromatoses, myxofibrosarcomas, soft-tissue perineuriomas, and congenital or adult fibrosarcomas. These data suggest that our reverse transcription-polymerase chain reaction assay is a reliable method to detect FUS-CREB3L2, which can thus help in accurately diagnosing LGFMS.

Adolescent↗