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H Lyon

Publications and source records attributed to H Lyon.

At least 19 recordsLinked to original sources
PubMed1995

Non-hazardous organic solvents in the paraffin-embedding technique: a rational approach. Aliphatic monoesters for clearing and dewaxing: butyldecanoate.

The aim of this study was to substitute hazardous compounds, used in tissue processing and dewaxing, with compounds having lowest possible toxicity and inflammability without impairing the morphology, staining characteristics, or diagnostic value of the tissue sections. All aromatic compounds and aliphatic hydrocarbons (e.g. alkanes, isoparaffins, petroleum distillates, etc.) were rejected, primarily due to their high vapour pressure. Based on a theoretical study of compounds used for clearing, a number of non-hazardous potential substitutes were chosen. The following experimental study narrowed the group to three unbranched, saturated, aliphatic monoesters containing 12-14 carbon atoms. On large-scale testing of these compounds, we found butyldecanoate to be the closest to an ideal substitute for aromatic and aliphatic hydrocarbons in the histology department: the section quality is at least equal to that obtained with xylene. For dewaxing, it is used at 30-35 degrees C. Butyldecanoate is not suitable as a pre-mounting agent. In practice, this is no problem as modern mounting agents permit mounting of coverslips directly from ethanol without impairing the appearance of the section in the microscope. Butyldecanoate has only a slight odour, insignificant vapour pressure (< 0.01 kPa at 20 degrees C), and does not present a fire hazard (flash point 134 degrees C). The introduction of this compound in the laboratory poses no health hazard, and the substance is biodegradable.

Animals↗
PubMed1994

Synovial sarcoma. An immunohistochemical study of the epithelial component.

Twenty-five synovial sarcomas were studied with a battery of antibodies directed against keratin and epithelial membrane antigen (EMA). The keratin antibody MNF 116 showed reactivity in 24 tumors. In addition, 22 tumors showed reactivity with the antibody Keratin Wide Spectrum, 20 with the antibody Keratin 56, 64, and 19 with CAM 5.2. Seventeen tumors showed reactivity with EMA. The keratin and EMA reactivity was present in cells lining obvious cleft-like structures in biphasic tumors. In the spindle cell areas of both biphasic and monophasic fibrous tumors, we found clusters of a few reacting cells apparently located around small clefts. In the synovioblastic tumors, clusters of plump tumor cells reactive for both the keratins and EMA were present. In conclusion, we found that proper identification of epithelial differentiation in synovial sarcomas is facilitated by an immunohistochemical application of anti-epithelial antibodies. In most tumors, there was immunoreactivity for the same type of keratins as are normally identified in simple epithelia (the antibody CAM 5.2), but also for those found in stratified squamous epithelia (the antibody Keratin 56, 64). The results indicate that screening for epithelial features on paraffin sections in the various types of synovial sarcoma, even the poorly differentiated synovioblastic tumors, is improved if epithelial antibodies with a broad spectrum of reactivity are chosen.

Antibodies↗
PubMed1993

Deposition of C3, the terminal complement complex and vitronectin in primary biliary cirrhosis and primary sclerosing cholangitis.

Characteristics of primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are bile duct destruction and portal inflammation. Increased levels of circulating complement activation products are also present. This raises the possibility of involvement of complement-dependent cytotoxic mechanisms in the pathogenesis. Therefore, we investigated liver biopsy specimens from 21 patients with PBC, six patients with PSC and six controls for complement deposits by immunohistochemistry using polyclonal and monoclonal antibodies against C3d, the terminal complement complex (TCC) and vitronectin (S-protein). We found C3d, TCC and vitronectin deposits only in the portal tracts. C3d and TCC were present in the walls of the hepatic arteries and in the connective tissue stroma but never around the bile ducts. We found vitronectin deposits throughout the connective tissue, often independent of the TCC deposits. When vitronectin and TCC were co-localized, the staining patterns were inverse; that is, intense staining for TCC accompanied weak staining for vitronectin and vice versa. Occasionally complete dissociation between TCC and vitronectin staining was observed. Deposits of TCC and vitronectin showed a focal distribution leaving many portal tracts free of TCC. Our results question whether complement-dependent cytotoxic mechanisms take part in the bile duct destruction in PBC and PSC.

Adult↗
PubMed1991

Gallocyanin chromalum as a nuclear stain in cytology. I. A cytophotometric comparison of the Husain-Watts Gallocyanin chromalum staining protocol with the Feulgen procedure.

In the present study, the staining characteristics of the Gallocyanin chromalum technique devised by Husain and Watts are compared with the Feulgen reaction. Liver imprints, blood smears, and cervical smears were fixed in ethanol and stained with either the Husain and Watts Gallocyanin chromalum reagent or the Feulgen-Schiff reagent. The slides were then post-treated with 70% ethanol-HCl pH 1.0, or with phosphotungstic acid for 0.5-30 min. The integrated optical density of cell nuclei was measured with a VIDAS image analyzer. In the material stained with the Husain and Watts procedure, some Gallocyanin chromalum was removed from the nuclei in the early phase (5 min) of all the post-treatment steps, followed by a plateau phase where the integrated optical density remained constant for 30 min. In this phase, the nuclear absorbance was highly reproducible and of the same size regardless of the post-treatment. Both the Husain and Watts procedure and the Feulgen-reaction gave quantitative staining of DNA. The Gallocyanin chromalum stain after Husain and Watts is a quick staining procedure for quantitative evaluation of DNA in cytological material. Proper rinsing of the slides is necessary for a good reproducibility of results.

Blood Cells↗
PubMed1991

Clogging of biliary endoprostheses. A morphologic and bacteriologic study.

The main problem encountered with the use of biliary endoprostheses is their tendency to clog, which necessitates their exchange. We studied this problem by performing light and electron microscopy and bacterial cultures on both unused and clinically used endoprostheses. These examinations showed several basic defects in their manufacture, such as irregular inner surfaces and badly constructed side holes. The deposit that ultimately led to their occlusion was found mainly to be concentrated around the side holes. Minimizing the amount of material, bacteria, and plant fibres adhering to the endoprosthesis is the desired goal and may be achieved by improving their manufacture and design.

Bacteria↗
PubMed1989

The correlation between uptake of methyl green and Feulgen staining intensity of cell nuclei. An image analysis study.

Paraffin sections of rat tissue fixed in either formaldehyde solution (3.6% w/v) or in Carnoy's fluid were stained using standardized Methyl Green-Pyronin procedures with the dyes used either simultaneously or in sequence. The sections were evaluated for the uptake of the two dyes by cell nuclei, nucleoli and cytoplasm using colour TV-image analysis. The parameters measured were integrated optical density and the surface area of the object. The sections were then destained and a Feulgen reaction was performed. The coordinates of the cells measured after the simultaneous Methyl Green-Pyronin method were stored in the computer, making it possible to measure the same cells in the Feulgen-restained sections. Image analysis gave results which invalidate the sequential methods as opposed to the simultaneous method. Mean optical densities were significantly increased for both dyes with the simultaneous method after formaldehyde fixation as compared to Carnoy fixation. The quantitative correlation of Methyl Green and DNA in the simultaneous technique was found to parallel exactly that of the Feulgen stain. In conclusion, the simultaneous Methyl Green-Pyronin technique is recommended while the sequential methods seem to be of less value.

Animals↗
PubMed1988

Electrically-induced collagen calcification in pig skin. A histopathologic and histochemical study.

Deposition of calcium salts on collagen fibres in skin of fully anaesthetized pigs was induced by exposure to direct current (d.c.). In biopsies obtained from cathode areas successively from day 1 to day 7 after exposure the histopathologic and histochemical changes before and after the initial deposition of calcium salts have been examined. For comparison skin sites with intradermal injected calcium hydroxyapatite crystals were studied in addition. Small areas of calcified collagen and elastic fibres were noted in viable tissue 2 days after d.c. exposure. In succeeding days the calcified areas enlarged with new deposits always more superficial and closer to the epidermis than the original calcium deposits. Preconditions for calcification appear to be (1) a pH change in basic direction and/or the electrochemical processes specific to the cathode area and (2) a viable tissue. Elastic fibres appear to have a lower calcification threshold than collagen fibres. A positive staining for glycoproteins (PAS) and glycosaminoglycans (alcian blue pH 2.5) was noted in the calcified collagen fibres simultaneously with the calcification. In succeeding days the intensity of the staining reactions increased. Whether changes in the glycoproteins, collagen and its intimately bound glycosaminoglycans precede the calcification or the staining reactions develop secondarily to this deposition is not known. However, seven days after intradermal injections of Ca-apatite crystals in pig skin small and large crystals were observed ultrastructurally without any relation to collagen fibrils, but the calcified tissue presented a positive PAS and alcian blue reaction from day 2. Thus the PAS and alcian blue stainings in this model develop secondary to the deposition of calcium salts.

Animals↗
PubMed1988

Staining of the nucleolus with protein and RNA stains for automatic measurement of nucleolar size in paraffin sections.

In this paper two staining methods for automatic assessment of nucleolar profile area in paraffin sections of breast carcinomas using the IBAS 2000 image analyzer are reported. In the first method, the nucleolar proteins are stained with phloxine B, in the second the nucleolar RNA is stained with methyl green-pyronin. Both methods are fully reproducible. Statistically, the profile areas observed for the same patient by the two methods were found not to differ significantly. Because of their rigidity and their size in relation to section thickness, nucleoli are particularly attractive cell structures for quantitation, for instance in studies of variables that might be useful in establishing the prognosis for carcinoma patients.

Breast Neoplasms↗
PubMed1986

Nucleic acid staining with the methyl green-pyronin method. A comparison of the use of pure dyes and commercially available dyes.

We compared the staining obtained using commercially available pyronin Y samples with that obtained using pure pyronin Y in a standardized methyl green-pyronin procedure. In addition, the importance of the dye content of the anhydrous dye was investigated by varying the dye content by the addition of pure pyronin Y to one of the commercially available pyronin Y samples. We found that, for routine histological work, commercially available pyronin Y samples may produce acceptable results provided the sample can be shown by spectrophotometry to contain at least 43% pyronin Y.

Animals↗
PubMed1986

The blood hepatocytic barrier: a light microscopical, transmission- and scanning electron microscopic study.

The normal blood hepatocytic barrier (BHB), comprised by the endothelial lining cells and the perisinusoidal space, was investigated, and it was concluded that the BHB is a complex structure in which each individual part serves several functions. Immunohistochemical staining for factor VIII showed endothelial lining cells to be positive. By TEM and SEM the endothelial cells were seen to be fenestrated without a basal lamina. They possess numerous endocytotic vesicles. The perisinusoidal space contains the lipocytes and a matrix composed of fibrils, and a microfilamentous to granular material. The nature of these matrix components was poorly analyzable by conventional methods. Lipocytes were visualized by LM in: sections stained with oil red 0 after fixation in Baker's formol-calcium and following post-fixation in dichromate, and toluidine-blue-stained Epon-embedded sections. TEM revealed numerous cytoplasmic processes rich in microfilaments encircling the sinusoids.

Azo Compounds↗
PubMed1985

Tubular carcinoma of the breast. A long term follow-up.

The aim of this study is to provide a long-term follow-up of patients with tubular carcinoma and to investigate whether the separation of the mixed type of tubular carcinoma, tubular component more than 75%, from invasive ductal carcinoma with a major tubular component (ductal carcinoma MTC), tubular component 50 to 75%, is supported by long term follow-up. For this study 388 consecutive breast carcinomas were selected from the files of the Department of Pathology, Bispebjerg Hospital, Denmark for the years: 1956-59. Twenty tubular carcinomas were found and 16 ductal carcinomas MTC were also identified. For each patient with tubular carcinoma and ductal carcinoma MTC, two controls with ductal carcinoma NOS were selected. The patients in these four groups were followed until 1 April 1982. None of the patients were lost to follow-up. Among the 20 patients with tubular carcinoma, 10 died within this period compared to 37 of the 40 controls. Of the 16 patients with ductal carcinoma MTC, 15 died compared to 29 of the 32 controls. The difference in Kaplan-Meier survival curves between the tubular carcinomas and their controls is highly significant. There is no significant difference between ductal carcinomas MTC and their controls. These findings are not changed significantly when 5, 10, and 20 year survival rates are corrected for expected survival. This study demonstrates long-term survival for patients with tubular carcinoma as compared to ductal carcinoma NOS. There is no difference in long-term survival between ductal carcinoma MTC, tubular component between 50 and 75%, and ductal carcinoma NOS. It therefore seems appropriate to set 75% tubular component as a reasonable cut-off point for the mixed type of tubular carcinoma.

Adenocarcinoma↗
PubMed1984

Microtechniques for flow cytometric analysis of aqueous humor lymphocytes.

Flow cytometric analysis of monoclonal antibody labelled lymphocytes is an important tool in understanding the immune response. Microtechniques were developed to analyze lymphocytes in small amounts of ocular fluids. Optimal labelling volumes and concentrations for Leu 2a, Leu 3a, Leu 4 and Leu M3 antibodies were determined. The ability to label and reproducibly analyze cell samples with as few as 1000 cells is demonstrated.

Antibodies, Monoclonal↗
PubMed1984

Preparation and characterization of methyl green tetrafluoroborate.

Commercial methyl green dyes were converted to tetrafluoroborate by means of NaBF4-solution, the compounds thus obtained were analytically pure. It was shown to be possible to distinguish between a "methyl" and an "ethyl" compound by means of NMR spectroscopy. The dyes are stable in buffered aqueous solution, and in crystalline form. A spectrophotometric assay is proposed.

Borates↗
PubMed1984

Spectrophotometric characteristics and assay of pure pyronin Y.

The spectrophotometric characteristics of analytically pure pyronin Y have been investigated. Addition of metal ions (Fe3+, Zn2+, and Mg2+) and of dextrin were shown not to influence the absorption characteristics. The composition of the solvent strongly influenced the value of the extinction coefficient. Aqueous ethanolic solutions with a content of about 50% ethanol gave higher epsilon-values than those found for more concentrated ethanol solutions. The difference can be explained by the existence of a solvent-solute complex in the less concentrated ethanol solutions. A new spectrophotometric assay is proposed using the epsilon-value 11.7 X 10(4) lmol-1 cm-1 found in aqueous ethanol (52%) as standard.

Iron↗
PubMed1983

Antiretinoblastoma monoclonal antibodies.

Mouse-mouse somatic hybridization techniques were used to produce monoclonal antibodies directed towards antigen expressed on retinoblastoma-derived tissue culture cell lines. Four monoclonal antibodies were produced with varying avidity which were reactive against allogeneic retinoblastoma-associated antigens. Sensitivity and specificity was demonstrated using ELISA and chromium release assays. Immunofluorescent antibody studies suggest that these monoclonal antibodies may be useful diagnostically.

Animals↗
PubMed1982

Purity of commercial non-certified European samples of Pyronin Y.

The purity of six European non-certified samples of Pyronin Y was compared with that of two American samples certified by the Biological Stain Commission. The methods used were spectrophotometry and a Methyl Green-Pyronin staining test (both as applied by the Biological Stain Commission), thin layer chromatography, mass spectrometry, determination of pH, and content of some electrolytes. It was found that none of the European batches of Pyronin Y passed the complete test as prescribed by the Biological Stain Commission. Their dye content was uniformly low (between 5 and 19%). Furthermore, thin layer chromatography and mass spectrometry revealed that two of the dye samples contained no Pyronin Y or only traces. It is concluded that assessment of an unknown sample of a dye labelled Pyronin Y should be initiated with thin layer chromatography. The pH and content of electrolytes in an aqueous solution of the dye should also be determined in order to obtain reproducible staining results. Finally, the value of the work performed by the Biological Stain Commission is underlined, although more sophisticated methods are necessary for testing the purity of dyestuffs.

Cations↗