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At least 649 records · Page 36Linked to original sources
PubMed1979

Analysis of the electron spin resonance spectrum of human liver tissue embedded in paraffin.

The ESR spectra of the liver samples embedded in paraffin of newborn, adult, cirrhotic and control individuals always display the g approximately 2.05 signal and occasionally also the g = 4.3 line and the signal of free radicals. In adults, the amplitude of the g approximately 2.05 signal is negatively correlated with that of the g approximately 4.3 signal; in infants aged from three months to one year this correlation is positive. The copper content of the liver is in linear correlation with the amplitude of the g approximately 2.05 signal. The hyperfine structure of the part of the g approximately 2.05 signal recorded at low magnetic field may be of three types: it may correspond to Cu2+ centers of axial symmetry of type I, II or I + II. The parameters of the signal are the following: type I center, g = 2.35 +/- 0.05, g = 2.05 +/- 0.01, A < 100 gauss; type II center, g = 2.25 +/- 0.03, g = 2.05 +/- 0.01, A = 160 +/- 20 gauss. On the basis of the amplitude of the g approximately 2.05 signal, the copper content of the liver tissue can be estimated from paraffin blocks with an error of 30%, without losing the tissue embedded for histological examination.

Adolescent↗
PubMed1997

Simultaneous restitution of matrix and cells in gastric ulcer: use of a combined in-situ hybridization and immunohistochemistry technique applicable to paraffin-embedded tissue.

The restoration of gastric tissue after ulceration involves cellular and matrix components. Our aim was to investigate the kinetics of collagen expression and cellular proliferation in an animal model of gastric ulcer. To demonstrate the expression of type I and IV collagen mRNAs by proliferating cells, a method combining in-situ hybridization and immunohistochemistry was devised. In order to avoid the disadvantages of radioisotopes, digoxigenin-labeled RNA-riboprobes were utilized and combined with single-step immunohistochemistry. This method proved sensitive enough to detect type I and IV procollagen mRNA transcripts in the submucosal area beneath the ulcer crater or adjacent to the ulcer rim. In addition, a subset of cells transcribing either procollagen type I or IV RNA was concomitantly positive for proliferating cell nuclear antigen by immunohistochemistry. Focal proliferation of cells simultaneously expressing extracellular matrix components may therefore occur in the gastric submucosa after ulceration, starting as soon as 3 days after the insult and continuing for several weeks. The devised method of combined in-situ hybridization and immunohistochemistry can be used with standard paraffin-embedded tissues, yields results within 2 days, and avoids radioisotopes.

Acetic Acid↗
PubMed1996

A rapid and efficient method for DNA extraction from paraffin wax embedded tissue for PCR amplification.

DNA from archival, formaldehyde fixed, paraffin wax embedded human tissue, suitable for amplification by the polymerase chain reaction (PCR), was obtained using a microwave method based on the capture of DNA by magnetic beads. Fragments of the alpha-1-antitrypsin gene (AAT) and the apolipoprotein E gene (APOE) were amplified successfully from human liver and brain tissue, respectively. This procedure provides a more rapid, simple and efficient method for reproducibly obtaining DNA from preserved tissue that has been kept in storage for up to 30 years.

Journal Article↗
PubMed1996

[The relationship between placental pathology and certain pathogens detected in paraffin-embedded tissues in cases of intrauterine growth retardation].

OBJECTIVE: To study the relationship between placental pathology and certain pathogens detected in paraffin-embedded placental tissues in cases of intrauterine growth retardation (IUGR). METHODS: The PCR-DNA techniques were used for determination of pathogens, including toxoplasma, cytomegalovirus and herps simplex type II in paraffin-embedded placental tissues from 53 cases of IUGR. RESULTS: Among 53 cases of IUGR, the pathogens were detected in 19 cases (35.85%). The relationships of pathogens detected to placental pathology were analyzed. Pathogens were found in 10 of 18 placentas with villitis, 7 of 11 placentas with villous maturation retarded and 2 of 3 intervillous space infections respectively. The incidence of infection in the pathological placentas was 59.38%. CONCLUSIONS: The study suggested that the haematogenous infections could play important roles in unknown causes of IUGR.

Adult↗
PubMed1999

Reappraisal of potassium permanganate oxidation applied to Lowicryl K4M embedded tissues processed by high pressure freezing/freeze substitution, with special reference to differential staining of the zymogen granules of rat gastric chief cells.

The high pressure freezing/freeze substitution technique is known to yield a deep vitreous freezing of tissues. Combination of this technique with Lowicryl K4M embedding allows us histochemical studies of dynamic cellular processes with improved structural preservation. The disadvantage of Lowicryl K4M embedding is its poor electron density in electron microscopy. To address this problem, we examined the effects of KMnO4 oxidation applied to Lowicryl K4M embedded rat gastric glands processed by high pressure freezing. The KMnO4 oxidation-uranyl acetate-lead citrate sequence succeeded not only in contrast enhancement of cellular components, but also in differential staining of the zymogen granules of rat gastric chief cells. This technique could be applied to semi-thin sections of Lowicryl K4M embedded rat gastric glands. The KMnO4 oxidation-toluidine blue staining provided sufficient contrast with regard to the zymogen granules. Various experiments used in this study verified that the KMnO4 oxidation plays an essential role in the differential staining of the zymogen granules. Combined use of the KMnO4 oxidation with phospholipase A2-immunostaining demonstrated that gold labeling was localized to the zymogen granules without the loss of immunolabeling. Energy dispersive X-ray microanalysis revealed some manganese depositions on the zymogen granules. It is highly anticipated that the KMnO4 oxidation will become a useful tool for histochemical investigations combined with cryofixation/freeze substitution and low temperature embedding techniques.

Acrylic Resins↗
PubMed1993

[Analysis of the Duchenne muscular dystrophy gene with PCR analysis in paraffin-embedded tissue. A new diagnostic possibility].

Analysis of DNA from archival, paraffin-embedded muscle tissue allowed tracing of the mutated dystrophin gene in two families with Duchenne muscular dystrophy. There were no living patients in these families. In one family this diagnosis contributed to the birth of a normal male, in the other family to the demonstration of carrier status. These analyses, based on the polymerase chain reaction, are relatively rapid and simple, and lend increased value to old tissue samples stored in pathology departments.

DNA↗
PubMed1996

Detection of Mycobacterium paratuberculosis in formalin-fixed paraffin-embedded tissues by the polymerase chain reaction.

The polymerase chain reaction (PCR) utilizing primers specific for the IS900 sequence of Mycobacterium paratuberculosis was applied to tissue sections of formalin-fixed, paraffin-embedded ileum from cattle with Johne's disease and the results compared to those obtained with acid-fast (Ziehl-Neelsen) and immunohistochemical staining. The PCR was positive in 19/21 tissues (90%) while Ziehl-Neelsen staining was positive in 18/21 (86%) and immunohistochemical staining in 21/21 (100%). The Ziehl-Neelsen and immunohistochemical stains are not, however, specific for M. paratuberculosis. The PCR for detection of M. paratuberculosis using the IS900 sequence is a specific and relatively sensitive method for confirmation of Johne's disease and its application to formalin-fixed, paraffin-embedded tissues may be useful for confirmation of dubious cases, for retrospective studies and for epidemiological analyses.

Animals↗
PubMed1993

[Ultrastructural in situ hybridization: detection of mRNA on sections of tissue embedded in lowicryl resin].

In situ hybridization for the detection of RNAm in ultrathin tissue sections embedded in lowicryl resin is reported. This method proved suitable for both tissues and cell cultures, using either complementary DNA probes or synthetic oligonucleotides, labeled with a radioisotope or biotin. This method seems to strike a satisfactory balance between preservation of cell ultrastructure and sensitivity.

Acrylic Resins↗
PubMed2005

Protein-embedding technique: a potential approach to standardization of immunohistochemistry for formalin-fixed, paraffin-embedded tissue sections.

A serial study was performed to develop a protein-embedding technique for standardization of immunohistochemistry (IHC) on formalin-fixed, paraffin-embedded (FFPE) tissue sections. A protein carrier matrix must have two phases, a liquid phase to allow uniform mixing of a protein and a solid phase forming a 'block' that can be fixed and processed in the same manner as human tissue. This standardized protein block would serve as a source of thin sections for control of IHC and therefore must also withstand the boiling conditions of antigen retrieval (AR). After multiple experiments, a method was developed utilizing polymer microsphere (beads) as a support medium for protein. The method showed particular promise for quantitative IHC.

Animals↗
PubMed1986

Lectin histochemistry of glycolipid storage diseases on frozen and paraffin-embedded tissue sections.

Lectin histochemical studies were performed on frozen and paraffin-embedded brain tissue sections from six cases of galactosylceramide lipidosis (i.e., globoid cell leukodystrophy, or Krabbe's disease) in Twitcher mice and one case of canine infantile GM1-gangliosidosis. The globoid cells in Krabbe's disease stained with Ricinus communis agglutinin-I (RCA-I), peanut agglutinin (PNA), and Bandeirea simplicifolia agglutinin-I (BS-I) in frozen sections. However, paraffin sections and frozen sections pretreated with chloroform-methanol or xylene, from the same animals, stained with Concanavlia ensiformis agglutinin (ConA), wheat germ agglutinin (WGA), and succinylated-WGA (S-WGA), in addition to staining with RCA-I, PNA, and BS-I. The affected neurons of canine infantile GM1-gangliosidosis stained only with RCA-I in frozen sections. In paraffin sections, however, these cells were negative with RCA-I but positive with BS-I, ConA, Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA) and Ulex europaeus agglutinin (UEA-I) in paraffin sections. These results indicate that in paraffin processing of glycolipid storage disease tissue, some lectin receptors are lost and others are unmasked. The retained receptors can be stained with specific lectins and could serve as markers to characterize and differentiate among the various glycolipid storage diseases.

Animals↗
PubMed1984

Improved methods for molding, facing and sectioning glycol methacrylate embedded tissue blocks.

Improvements in glycol methacrylate embedding, block facing, trimming, and sectioning are described. The improvements are derived from a novel molding system, a multipurpose instrument for rapid block facing, trimming and examination, and a device for removing unwanted sections from the microtome knife while sectioning is in progress. Together, these methods facilitate specimen preparation and result in a significant reduction of the time required to prepare high resolution, very thin sections for light microscopy.

Animals↗
PubMed1997

Paraffin-embedded tissue as a source of RNA for gene expression analysis in oral malignancy.

OBJECTIVE: To assess the feasibility of using archival oral mucosal tissue to examine gene expression at the ribonucleic acid (RNA) level. MATERIALS AND METHODS: We describe the isolation of RNA from 8 microns sections of formalin-fixed paraffin-embedded oral mucosal tissue. RNA was reverse transcribed and three candidate genes amplified by polymerase chain reaction (PCR). The ribosomal protein S14 gene is a housekeeping gene which has been used as an internal standard in several quantitative PCR protocols. The thymidine kinase (TK) gene is expressed at low levels in most tissues and, with a well-documented genomic organisation, is a useful tool for discrimination between genomic DNA and cDNA. The RI alpha gene is reported to be overexpressed in many cancer cell lines, in malignant tissue and in vitro transformed cells. RESULTS: The S14 gene, the TK gene and the RI alpha gene of the cAMP-dependent protein kinase (PKA) were amplified successfully from formalin-fixed paraffin-embedded tissue sections. The TK primer pair is a useful additional tool in the unambiguous identification of RNA-derived species. CONCLUSION: RNA suitable for reverse transcribed (RT)-PCR was extracted from archival oral mucosal tissue. This should permit rapid sequence analysis of transcribed tumor suppressor genes and oncogenes in this material. Furthermore, the RT-PCR approach described may allow quantification of gene expression in oral mucosal archival material processed in a standard fashion.

Carcinoma, Squamous Cell↗
PubMed1996

Detection of paraneoplastic anti-neuronal autoantibodies on paraffin-embedded tissues.

Anti-neuron-specific autoantibodies are widely recognised as useful, though non-specific, diagnostic markers of paraneoplastic neurological disorders. However, controversies on the best way to detect these autoantibodies have recently arisen, and the use of different procedures for their detection by different laboratories has made results difficult to compare. The aim of this study was to adapt the existing immunohistochemical techniques used for the detection of anit-neuron autoantibodies to improve their visualisation and to facilitate a wide application of these procedures. Sera and cerebrospinal fluid (CSF) were obtained from 15 patients known to carry paraneoplastic anti-neuronal autoantibodies; in addition, one serum with "atypical" anti-neuron autoantibody and 18 control sera were studied. Paraformaldehyde-fixed, paraffin-embedded rat nervous tissue and formalin-fixed, paraffin-embedded human nervous tissue treated in a microwave oven were used as substrate; the reactions were developed by immunoperoxidase methods. At the dilutions used for diagnostic purposes, all the sera and CSFs showed staining whose intensity and specificity was comparable to that obtained using frozen tissue; the end-point dilutions were, however, reduced. The atypical pattern of staining of one serum was confirmed and better emphasised using these procedures; all control sera and CSFs were negative. The morphology was improved by the use of paraffin-embedded tissues; moreover, the results obtained are permanent because of peroxidase staining, which makes it possible to use them as standards for further investigations and for comparison between different laboratories. The convenience of using paraffin-embedded material could facilitate a wide application of these procedures in clinical neurology.

Animals↗
PubMed1999

PCR detection of Clostridium perfringens type D in formalin-fixed, paraffin-embedded tissues of goats and sheep.

A polymerase chain reaction (PCR) was used to identify the genes encoding the alpha, epsilon and beta toxins of Clostridium perfringens in formalin-fixed, paraffin-embedded intestinal tissues of goats and sheep. When pure cultures of Cl. perfringens types B and D were used as control templates in the PCR, products of the following sizes were observed on the agarose gel: 247 bp (alpha primers), 1025 bp (beta primers) and 403 bp (epsilon primers). When used to identify Cl. perfringens type D in formalin-fixed, paraffin-embedded intestinal tissues of goats and sheep, the PCR technique resulted in the detection of this micro-organism in 11 out of 13 samples known to be infected with Cl. perfringens. No false positive results were obtained when 13 culturally negative samples were analysed by the PCR technique.

Animals↗
PubMed1992

Proliferating cell nuclear antigen counts in formalin-fixed paraffin-embedded tissue correlate with Ki-67 in fresh tissue.

Cell proliferation can be studied by a variety of techniques. However, most require fresh tissue. To evaluate cell proliferation in formalin-fixed paraffin-embedded sections, the authors immunohistochemically studied 35 tumors and 11 samples of normal/hyperplastic tissue with PC10, a monoclonal antibody directed against proliferating cell nuclear antigen. Results were compared with those obtained with Ki-67 on fresh tissues. There was no significant difference between proliferating cell nuclear antigen and Ki-67 counts, which were strongly correlated (r = 0.8). Proliferating cell nuclear antigen positivity was easier to evaluate because morphology was better preserved in formalin-fixed tissue. The authors conclude that PC10 is an alternative to Ki-67 in evaluating cell proliferation and has the advantage of reacting with formalin-fixed paraffin-embedded tissue.

Antibodies, Monoclonal↗
PubMed1998

Ultrastructural detection of neuronally transported choleragenoid by postembedding immunocytochemistry in freeze-substituted Lowicryl HM20 embedded tissue.

Choleragenoid (cholera toxin B-fragment; CTB) is an anterograde, retrograde and transganglionic neuronal tracer. We describe a method for detecting CTB-labeled neuronal cell bodies, neurites and boutons at the ultrastructural level, using postembedding immunogold techniques on freeze-substituted Lowicryl HM20 embedded nervous tissue. Primary afferents and motoneurons were labeled by injection of CTB in the dorsal ramus of the C2 spinal nerve of the rat. Following fixation with paraformaldehyde (4%) and glutaraldehyde (0.25%), tissue sections from the spinal cord C2 segment were freeze-substituted and embedded in Lowicryl HM20 and subsequently processed with postembedding immunocytochemistry for CTB and glutamate. Immunogold particles indicating CTB immunoreactivity were found over primary afferents and motoneurons. In primary afferents in the central cervical nucleus (CCN) and motor nuclei, immunogold labeling was seen in boutons over vesicle-containing axoplasm and to a lesser extent over axoplasm devoid of vesicles, but not over mitochondria or axolemma. In motoneurons, immunogold particles were seen over the Golgi apparatus in the soma and over lysosomes in both soma and dendrites. Quantification of glutamate-like immunoreactivity in 20 CTB-labeled and 20 CTB-negative boutons in the neuropil was found similar, indicating that CTB does not interfere with the immunocytochemical detection of neuronal epitopes such as the transmitter substance glutamate.

Acrylic Resins↗
PubMed2002

Improved technique for fluorescence in situ hybridisation analysis of isolated nuclei from archival, B5 or formalin fixed, paraffin wax embedded tissue.

Fluorescence in situ hybridisation (FISH) is an effective method to detect chromosomal alterations in a variety of tissue types, including archived paraffin wax embedded specimens fixed in B5 or formalin. However, precipitating fixatives such as B5 have been known to produce unsatisfactory results in comparison with formalin when used for FISH. This study describes an effective nuclear isolation and FISH procedure for B5 and formalin fixed tissue, optimising the nuclear isolation step and nuclei pretreatments using tonsil and mantle cell lymphoma specimens. The protocol presented can be used to isolate nuclei and perform FISH on B5 or formalin fixed, paraffin wax embedded samples from a variety of tissue types.

Cell Nucleus↗
PubMed2003

An antigen retrieval method using an alkaline solution allows immunoelectron microscopic identification of secretory granules in conventional epoxy-embedded tissue sections.

Immunoelectron microscopy using chromogranin A-specific antibodies has been proposed as an efficient technique for identification of secretory granules (SGs) in tumor cells with evidence of apparent neuroendocrine differentiation. Using an antigen retrieval (AR) method, we succeeded in immunolabeling SGs with antibodies in ultrathin sections of routinely processed epoxy-embedded blocks of tissue. Samples of an insulinoma were fixed in 2% glutaraldehyde, postfixed in 1% OsO(4), and embedded in epoxy resin. Ultrathin sections were immunostained with chromogranin A-specific antibodies and gold-conjugated second antibodies. There was no significant labeling in the absence of AR. Neither etching with sodium metaperiodate nor microwave irradiation of ultrathin sections in citrate buffer (pH 6.0) or in EDTA buffer (pH 8.0) was effective in improving the efficiency of immunolabeling. However, ultrathin epoxy-embedded sections that were microwaved in alkaline solution (pH 10) were adequately labeled (5.2 +/- 0.34 particles per SG). Moreover, considerably improved efficiency of immunostaining was achieved by microwaving sections in alkaline solution (pH 10) with subsequent immunostaining at 60C (12.2 +/- 0.51 particles per SG). This method can also be applied to epoxy-embedded sections obtained from formalin-fixed, paraffin-embedded blocks of tissue and was even valid for an old epoxy-embedded block of tissue prepared 15 years previously.

Acrylic Resins↗