Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tissue Embedding”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 829 records · Page 46Linked to original sources
PubMed1997

An improved method to detect beta-galactosidase activity in transgenic mice: a post-staining procedure on paraffin embedded tissue sections.

The Escherichia coli beta-galactosidase gene is frequently used as a reporter gene in transgenic studies because its activity can be easily detected at the cellular level. Here we report a procedure for monitoring beta-galactosidase activity directly in tissue sections, which involves the use of a mixture of ethanol and poly-ethylene-glycol as a fixative (Kryofix) and a special paraffin characterized by a lower fusion point of 42 degrees C. After embedding and cutting, the sections are stained by the chromogenic substrate 5-bromo-4-chloro-3-indoyl-beta-D galactopyranoside (X-Gal). This procedure allows both the retention of a high level of beta-galactosidase activity and the preservation of good tissue morphology. Furthermore, it can be combined with immunohistochemical methods to detect other cellular components without compromising reporter gene detection.

Animals↗
PubMed1988

Antisera against epitopes resistant to denaturation on T3 (CD3) antigen can detect reactive and neoplastic T cells in paraffin embedded tissue biopsy specimens.

Polyclonal rat antisera, raised against affinity purified CD3 antigen, gave strong immunoenzymatic labelling of T cells in routine paraffin embedded sections, with negligible background staining. The specificity of these reactions was confirmed by staining biopsy specimens from 21 previously phenotyped non-Hodgkin's lymphomas (including 14 of T cell origin and six of B cell origin). It is suggested that the ability of the polyclonal anti-CD3 antisera to detect T cells in paraffin sections is due to the presence in these sera of antibodies against fixation resistant epitopes on CD3 antigen, and that immunisation with purified denatured preparations of other white cell associated antigens may broaden the range of antibodies suitable for the phenotypic analysis of leucocytes in routine histological samples.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1992

Detection of African swine fever viral antigens in paraffin-embedded tissues by use of immunohistologic methods and polyclonal antibodies.

Tissues obtained from pigs inoculated with African swine fever virus (ASFV), fixed by vascular perfusion using glutaraldehyde, and embedded in paraffin or araldite were used for an immunohistologic electron microscopic study. To detect ASFV antigens, 4 methods were used on paraffin sections with or without pretreatment of the tissues. Use of biotinylated anti-ASFV antiserum combined with avidin-biotin complex and peroxidase proved to be the most suitable method, and antigen was detected in tissues infected with 2 ASF viruses of different virulence. Use of the glutaraldehyde fixation method should ensure optimal morphologic (structural and ultrastructural) data while allowing an immunohistologic study, and add to knowledge of the pathogenesis of ASF.

African Swine Fever↗
PubMed2000

Detection of mycobacterial DNA in cervical granulomatous lymphadenopathy from formalin-fixed, paraffin-embedded tissue by PCR.

Cervical tuberculous lymphadenitis is the most common form of inflammatory neck mass in Korea. The diagnosis of tuberculosis requires proof of the presence of Mycobacterium tuberculosis by acid-fast staining or bacterial growth in culture. However, these are often difficult in cervical tuberculous lymphadenitis. The aim of this study was to investigate the value of the polymerase chain reaction (PCR) technique for detection of mycobacteria in routinely processed tissue sections of cervical granulomatous lymphadenopathy. In this retrospective study, twenty formalin-fixed, paraffin-embedded biopsy specimens from clinically and/or histopathologically diagnosed cervical granulomatous lymphadenopathy were analyzed for mycobacterial DNA by PCR. Two different primers to amplify mycobacterial-common 383-base pair (bp) DNA and Mycobacterium tuberculosis-complex-specific 123-bp DNA were used. Positive PCR products were sequenced directly. Mycobacterial-common DNA (383-bp positive) was found in 10 of the 20 cases. Among them, 7 cases were PCR positive with both primer sets. These seven cases can be considered as tuberculosis. The other three cases indicated possible atypical mycobacteriosis. PCR is a useful technique for the demonstration of mycobacterial DNA fragments in patients with clinically suspected cervical tuberculous lymphadenitis who have acid fast-negative histology and/or unsuccessful mycobacterial cultures.

Base Sequence↗
PubMed1989

Different opinions on classification of DNA histograms produced from paraffin-embedded tissue.

Flow cytometric DNA ploidy determination has been regarded as an objective prognostic parameter in several types of human cancer. To test whether DNA histograms are similarly interpreted, a series of flow cytometric DNA histograms was posted to six investigators working in the field for independent classification. The histograms were produced from paraffin-embedded adrenal adenomas or non-neoplastic tissue and had several different patterns. Only 44% of the histograms were similarly classified by all investigators, and 85% by five of the six participants, when DNA ploidy was evaluated. Different criteria for tetraploidy existed, and also some uncertainty in classifying peridiploid and small aneuploid peaks. It is concluded that lack of consensus on histogram classification may result in widely varying percentages of DNA aneuploid tumors found even if the data are similar. Until general agreement is reached on the definition of DNA aneuploidy and its subclasses, classification of DNA histograms is variable and subjective.

Adenoma↗
PubMed1990

Study of stringency conditions for human papillomavirus DNA detection on cell lines, frozen and paraffin-embedded tissue sections by in situ hybridization with biotinylated probes.

In situ hybridization was mainly used for typing human papillomavirus (HPV) in paraffin-embedded or frozen sections under stringent conditions (SC). We tested 5 different conditions of stringency with biotinylated HPV 1, 2, 16 and 18 probes on 3 cell lines (Sihà and CaSki with HPV16, HeLa with HPV18) by varying the concentration of formamide in the hybridization mixture and washings in order to determine the stringency conditions to be used to assess the presence of HPV and its typing: A-low stringency, hybridization at 35 degrees C below the melting temperature of DNA (Tm-35 degrees C) and washings without formamide; B-low stringency, hybridization and washings at Tm-35 degrees C; C-medium stringency, hybridization at Tm-35 degrees C and washings at Tm-12 degrees C; D-high stringency, hybridization at Tm-12 degrees C and washing without formamide; E-very high stringency, hybridization and washings at -12 degrees C. This study showed that HPV typing required a high stringency. On the contrary, under non stringent conditions (NSC), each cell line was positive with the heterologous probes. When 3 to 5 stringency conditions were assayed on 4 frozen samples, similar results were obtained. Typing required high stringency conditions whereas NSC allowed HPV detection. Furthermore, this study demonstrated the specificity of the reaction in lesions positive with more than one type. Stringent (Tm-12 degrees C) and non stringent (Tm-35 degrees C) conditions of hybridization were further applied to 57 biopsy sections (17 frozen and 40 paraffin-embedded specimens) from typical wart lesions and lesions suspected of HPV.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1994

The prognostic role of the DNA ploidy pattern in colorectal cancer analysis using paraffin-embedded tissue by an improved method.

To assess the prognostic value of DNA ploidy in colorectal cancer, compared with the histopathological findings, paraffin-embedded surgical specimens from 330 patients who underwent resection for primary adenocarcinoma were studied using a new modified method of flow cytometry. Of these specimens, 141 were DNA diploid and 189, DNA aneuploid, among which there were 3 DNA hypodiploid lesions. Of the ten variables studied in curative resection, DNA ploidy ranked fourth in prognostic significance according to the linear trend by the chi 2 test, after nodal status, grade of cellular differentiation, and degree of invasive growth, if the DNA ploidy pattern was classified into three categories. Conversely, DNA ploidy was the sixth most significant factor if DNA hypodiploidy was included in the DNA aneuploidy. The Cox multivariate analysis showed that DNA ploidy was one of the five significant factors independently determining prognosis; however, if adjustment for the modified Dukes' stage was made by the Mantel-Haenszel test, the survival difference between the diploid and aneuploid groups did not reach a statistically significant level. Thus, we conclude that from a practical point of view, DNA ploidy is not an essential factor which must be combined with histopathological variables for a better prediction of patient outcome.

Colorectal Neoplasms↗
PubMed1991

[Flow cytometric analysis of DNA content in paraffin-embedded tissue in head and neck cancer (the second report)--primary lesions of laryngeal cancer].

Flow cytometric analysis of DNA content using paraffin-embedded materials has become an important diagnostic, as well as prognostic, method for clinical pathology and investigative oncology. DNA content as measured in paraffin-embedded materials is closely related with that obtained from fresh specimens. This method also permits retrospective analysis on a lot of cases and studying different specimens of a tumor for intratumor heterogeneity. Flow cytometry was used to investigation of the DNA distribution in biopsy specimens from 30 patients with squamous cell carcinoma of the larynx. These patients had initially treated in our institute in the period from 1986 to 1988 and followed for two to four years. A modification of Hedley's method was used to prepare paraffin-embedded materials. DNA histogram were assessed in terms of DNA index (DI). The coefficient of variation for determination of DI ranged 4.2 to 13.7% (mean 7.8 +/- 2.4%). Using infiltrated lymphocytes and mesenchymal cells as an internal standards, aneuploid DNA histogram were found in 13 of 30 specimens (43.3%). DI ranged from 1.05 to 1.22. There was no significant correlation between DNA content and sex, age, tumor size, staging or treatment. The aneuploidy was found in 2 of 17 cases with well differentiated tumor (11.8%), 10 of 12 with moderately differentiated tumor (83.3%), one with poorly differentiated tumor (100%). 11.8% of patients with diploid tumor cells had recurrence during the interval of observation, compared to 38.5% of those with aneuploid tumor cells (p less than 0.05). In T1 lesions of glottic cancer aneuploid group had a significantly lower local control rate than diploid group (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1976

[An improved histofluorescence procedure for freeze-dried paraffin-embedded tissue based on combined formaldehyde-glyoxylic acid perfusion with high magnesium content and acid pH].

A technique is described for highly sensitive and precise visualization of central catecholamine systems in paraffin sections of freeze-dried tissue. The procedure is based on perfusion of the animal with a solution containing formaldehyde and/or glyoxylic acid, in the presence of a very high magnesium content (40 g MgSO4/150 ml solution) and acid pH. The perfused tissue is rapidly frozen, freeze-dried, treated with formaldehyde vapours (at +80 degrees C for 1 h), embedded in parffin in vacuo, and finally sectioned. The present technique has a sensitivity for the dopamine- and noradrenaline-containing systems that is comparable with that of the glyoxylic acid-Vibratome technique, which utilizes fresh, glyoxylic acid-perfused tissue. Thus, the preterminal axon pathways become fluorescent throughout their full extent and the several new terminal systems, discovered with the glyoxylic acid-Vibratome method, are well demonstrable. The method is also highly useful for the study of the cell bodies and their dendritic processes. The catacholamine fibre systems are visualized without any signs of diffusion and with a richness in detail. In animals pretreated with L-tryptophan and MAO-inhibitor the technique is also useful for studies on central indolamine-containing systems.

Animals↗
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↗
PubMed2005

Improved detection of mycobacterial DNA by PCR in formalin-fixed, paraffin-embedded tissues using thin sections.

PCR is a unique methodology allowing for the sensitive detection of mycobacterial DNA-sequences in cases in which no fresh material can be obtained for classic analyses. Despite the limitations of this technique, for example the less satisfactory quality of DNA from paraffin-embedded specimens and the high effort necessary to control contamination, PCR still represents a useful additional tool for routine diagnostic examinations of mycobacterial infections. Fragmentation of the DNA extracted from formalin-fixed, paraffin-embedded samples on the one hand and the rigid cell wall of mycobacteria on the other hand are obstacles to detecting the DNA of these microorganisms by PCR. Here, we describe a simple mechanical procedure that allows us to improve the detection of mycobacterial DNA with the use of thin (1 microm) sections instead of thicker sections. This could be explained by a gentle, mechanical opening of the acid fast mycobacterial cell wall. Thus, even the application of heat/cold shock treatments is not necessary. This inexpensive fast procedure can also be used for the detection of other infectious agents.

DNA, Bacterial↗
PubMed1995

PCR-based assays for the detection of monoclonality in non-Hodgkin's lymphoma: application to formalin-fixed, paraffin-embedded tissue and decalcified bone marrow samples.

In crucial cases the diagnosis of non-Hodgkin's lymphoma (NHL) still represents a challenge to the pathologist since morphological criteria do not always help to distinguish between reactive and malignant lymphoproliferations. Clonality assays are a useful supplement since monoclonal cell proliferation is strong evidence for malignancy. The polymerase chain reaction (PCR) can be utilized to establish the clonal origin of B- or T-cell lymphocyte populations by amplification of rearranged immunoglobulin and T-cell receptor (TCR) genes. In the present study DNA was isolated from a variety of neoplastic and nonneoplastic formalin-fixed, paraffin-embedded lymph nodes (n = 62), cutaneous tissue (n = 9), samples of miscellaneous origin (n = 11), and reported here for the first time, decalcified bone marrow samples (n = 35). These samples were submitted to PCR-based assays directed against the immunoglobulin heavy-chain (IgH), immunoglobulin kappa light-chain (IgL kappa), and TCR gamma chain genes. The impact of various decalcifying agents on the ability to amplify DNA was investigated by PCR-based amplification of a single copy gene. Buffered and nonbuffered EDTA was found not to impede amplification of DNA fragments up to 300 bp in length. In lymph node and cutaneous specimens monoclonality was detected in 83% of B-NHL cases using a seminested PCR approach for the amplification of IgH, whereas the same approach gave rise to monoclonal bands in 80% of bone marrow samples. The subsequent amplification of IgL kappa helped to raise the sensitivity of detection to 94%. Monoclonality was detected in seven of nine T-cell NHLs by amplification of TCR gamma.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1984

Myelin basic protein in the optic nerve of the developing albino rat: an immunoperoxidase study of paraffin embedded tissue.

The distribution of myelin basic protein (MBP) was determined by application of the unlabeled peroxidase-anti-peroxidase method to sections of paraffin embedded optic nerve taken from the developing albino rat. MBP was not detected in optic nerves from animals younger than 90 hours postnatum. MBP staining presented first as faint, diffuse deposits of chromagen which were found in approximately one-third of the 90 hour subjects. The number of MBP positive regions and the intensity of staining of these regions increased rapidly with age. There was no obvious radial gradient in the distribution of MBP in cross sections of developing optic nerves, nor were smooth central/peripheral gradients apparent in longitudinal sections.

Age Factors↗
PubMed1992

The cellular infiltrate in the liver of patients with fulminant hepatitis: analysis of paraffin-embedded tissue sections.

Intrahepatic infiltrate from 18 patients who died of fulminant hepatitis, was analyzed by an immunohistochemical method using formalin-fixed, paraffin-embedded liver sections and monoclonal antibodies. Inflammatory cells were characteristically located in the portal and periportal areas adjoining resting hepatocytes, but were infrequently found in the perivenular areas where hemorrhagic hepatocyte necrosis predominated. In the inflammatory infiltrate, T cells were the most predominant cell type, composing about two-thirds of the total hepatic infiltrate, followed by lysozyme-positive macrophages which composed about one-third of the total hepatic infiltrate, irrespective of the etiology of the fulminant hepatitis. On the other hand, B cells made up less than 2% in all cases, and plasma cells were also few, less than 2% in 12 of 18 cases. Furthermore, an enhanced display of beta 2-microglobulin on hepatocyte membranes was demonstrated in all cases with remaining hepatocytes, indicating an increased expression of class I MHC antigens on these cells. These results suggest that T cells may play an important role in the pathogenesis of the portal and periportal lesions of fulminant hepatitis, probably with a help of MHC class I antigens on hepatocytes, while hemorrhagic necrosis of hepatocytes around the central veins may be caused by a different mechanism, most likely a circulatory disturbance secondary to cell-mediated immune reactions in the periportal areas.

Acute Disease↗
PubMed2004

HOPE technique enables Western blot analysis from paraffin-embedded tissues.

In contrast to the spectrum of biochemical analyses of fresh material, that of archived specimens is widely restricted. Fixation of specimens with formalin, the most commonly used fixative, usually prevents further molecular analysis, since it leads to degradation of nucleic acids and denaturation of the antigenic determinants of proteins. To overcome these problems, the Hepes-glutamic acid buffer mediated Organic solvent Protection Effect (HOPE)-fixation technique has been developed, which preserves nucleic acids and antigenic determinants of proteins, thus expanding the applicability of immunohistochemical methods. In this study, we investigated whether HOPE-fixed tissue can be analyzed by Western blotting. Furthermore, a comparison with conventionally fixed and frozen material was made. The specimens used were tumor-free and obtained from lobectomies for lung cancer. All four antibodies tested, i.e., antibodies specific for focal adhesion kinase, surfactant protein A, PI-3-kinase, and IKKalpha, worked well if used for immunoblotting of HOPE-fixed and frozen tissue. By contrast, these antibodies showed no or only very weak specific binding if formalin-fixed specimens were analyzed. Our findings show that HOPE fixation maintains the antigenicity of proteins better than formalin fixation. The possibility for performing Western blotting with archived paraffin-embedded specimens extends the options for diagnostic and scientific analyses of fixed tissues.

Blotting, Western↗