Biomedical subjects

M Kasper

Publications and source records attributed to M Kasper.

At least 109 records · Page 6Linked to original sources

PubMed1995

Immunocytochemical distribution of E-cadherin in normal and injured lung tissue of the rat.

Affinity purified rabbit anti-mouse E-cadherin antibodies, reacting with diverse rat epithelia, were used to characterize epithelial changes in a radiation-induced fibrosis model of rat lung by immunoblotting techniques, immunoperoxidase and immunofluorescence microscopy. Immunostaining of normal rat lung tissues revealed a predominant staining of type II pneumocytes. Immunoelectron microscopy confirmed the immunohistochemical data of normal lung tissue obtained at the light microscopic level. In severely injured rat lung, we found enhanced immunoreactivity for E-cadherin at the surface of type I alveolar epithelial cells. The results suggest that E-cadherin is an adhesion molecule that is modulated after pathological alteration of the alveolar epithelium and that the antiserum may be useful for the characterization of normal and diseased rat epithelia.

Animals↗

PubMed1995

Immunohistochemical evidence for loss of ICAM-1 by alveolar epithelial cells in pulmonary fibrosis.

ICAM-1 is an intercellular adhesion molecule of the immunoglobulin supergene family involved in adherence of leukocytes to the endothelium and in leukocytic accumulation in pulmonary injury. In the current study, the antigen retrieval technique was used to detect ICAM-1 immunohistochemically in paraffin sections of lungs from human, mouse and rat as well as in bleomycin- or radiation-induced fibrotic lungs from rat and human. In normal lung tissue, the expression of ICAM-1 on alveolar type I epithelial cells is stronger than on alveolar macrophages and on endothelial cells. Preembedding immunoelectron microscopy of normal rat, mouse and human lung samples revealed selective ICAM-1 expression on the surface of type I alveolar epithelial cells and, to a lesser extent, on the pulmonary capillary endothelium and on alveolar macrophages. In fibrotic specimens, both focal lack and strengthening of immunostaining on the surface of type I cells was found. Alveolar macrophages were found focally lacking ICAM-1 immunoreactivity. In some cases, rat type II pneumocytes exhibited positive immunoreactions for ICAM-1. Immunoelectron microscopy with preembedded rat lungs (bleomycin-exposed cases) confirmed the altered ICAM-1 distribution at the alveolar epithelial surface. In the alveolar fluid of fibrotic rat lungs, in contrast to that from untreated controls, soluble ICAM-1 was detected by western blot analysis.

Animals↗

PubMed1995

Secretory group II phospholipase A2 in human atherosclerotic plaques.

Atherosclerotic plaques exhibit a series of features that are similar to those of chronic inflammation. Based on the fact that during inflammation several cell types synthesize and secrete a group II phospholipase A2 (PLA2), an immunohistochemical study was undertaken to explore whether this enzyme can be identified in human atherosclerotic lesions. Tissue specimens obtained from 13 patients who had undergone arteriectomy and three specimens with advanced atherosclerotic plaques obtained at autopsy were analyzed and compared to arteries free of atherosclerosis. The results showed that in all areas with atherosclerotic lesions, a staining with monoclonal antibodies raised against group II PLA2 was evident. In normal arteries without thickened intima, this immunostaining was completely negative. With the use of specific monoclonal antibodies against macrophages (anti-KP-1) and smooth muscle cells (anti-alpha-actin), PLA2-positive cells were identified as foam cells mainly derived from macrophages. In addition to these cells, other regions of the thickened intima gave a partially positive reaction with anti-PLA2 antibodies, but could not be stained with either anti-KP-1 or anti-alpha-actin. Some of these regions were localized on edges of calcification and cell necrosis. Other PLA2-positive regions seem to be associated with extracellular matrix structures. In summary, the findings of this study may be regarded as further evidence to support the link between atherosclerosis and chronic inflammatory processes. In view of the fact that the in vitro modification of lipoproteins by PLA2-treatment induces lipid deposition in macrophages, the results of this study suggest that group II PLA2 may actively be involved in the formation of foam cells in vivo.

Aged↗

PubMed1995

Expression of p53 and bcl-2 in correlation to clinicopathological parameters, hormone receptor status and DNA ploidy in breast cancers.

The expression of p53 and bcl-2 was immunohistochemically investigated in 61 formalin-fixed, paraffin-embedded invasive breast carcinomas. The study was aimed to elucidate the relationship between both markers and the correlation of p53 and bcl-2, respectively, to clinicopathological variables, to hormone receptor status and to DNA-ploidy. Twenty tumors showed a positive reaction with the monoclonal antibody DO-1 against p53 protein. Its immunohistochemical demonstration was significantly correlated with a tumor size larger than 2 cm, a low estrogen receptor status and DNA-aneuploidy. Bcl-2 was demonstrated in 51 breast cancers. Bcl-2 was preferably seen in low grade and hormone receptor positive tumors. We found a negative correlation between the immunoreactive scores of p53 and bcl-2, but in 17 carcinomas a coexpression of both proteins was seen. Cases with this coexpression did not differ significantly from the other tumors in clinicopathological parameters. In eight of these cases more than 10% of the cells were found to be positive for both markers. In four cases we could show many cells to exhibit both markers as it was assessed by an immunofluorescence double labeling technique.

Breast Neoplasms↗

PubMed1995

Distinct expression patterns of CD44 isoforms during human lung development and in pulmonary fibrosis.

The transmembrane glycoprotein CD44 represents a family of molecules, all encoded by one gene. The variability of the isoforms is generated by alternative splicing of the nuclear RNA. Apart from the abundant standard form (CD44s), the variant isoforms (CD44v) are mostly restricted to epithelia. The present study demonstrates the expression of CD44s and CD44v isoforms in embryonic and fetal lungs and in normal and pathologically altered (pulmonary fibrosis after radio- or chemotherapy) human adult pulmonary tissues. Using double immunofluorescence and avidin biotin complex (ABC) techniques on paraffin sections, presence of CD44s and CD44v isoforms (CD44v4, CD44v6, CD44v9) has been analyzed. In normal lung tissue, CD44s is present at the cell surface of alveolar macrophages, in some interstitial cells and in epithelial cells. It is also present in epithelial and non-epithelial cells during lung development. CD44v isoforms containing exon v6 and v9 encoded epitopes are selectively detectable in normal epithelial cells with a strong basolateral distribution pattern in the entire population of type II pneumocytes and in basal cells of the bronchial epithelium. During development exon v9 encoded isoforms appear at the pseudoglandular stage, whereas CD44v6 has only been found at the saccular stage. Examination of 12 fibrotic lung samples has revealed major alterations in the CD44 expression in comparison to normal lung tissue. These changes include cytoplasmic deposits of CD44s in alveolar epithelial cells and reduced expression of the CD44v6 and CD44v9 isoforms in alveolar epithelial and bronchial epithelial cells. The results suggest that CD44v isoforms may be utilized by type II pneumocytes in epithelial-mesenchymal interactions and in the maintenance of the pulmonary histoarchitecture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Differentiation of human trophoblast populations involves alterations in cytokeratin patterns.

Cytokeratins (CKs) are related to proliferation and differentiation of epithelial cells. Little knowledge exists about CK patterns in human trophoblast subpopulations (villous and extravillous trophoblasts). To better understand differentiation and function of trophoblast components, we studied the distribution patterns of CKs in the placenta throughout pregnancy. A panel of well-defined monoclonal antibodies against different types of cytokeratins, vimentin, and fibrin, was used on frozen and paraffin sections. CK8, 18, and 19 were expressed in all the villous and extravillous trophoblastic subsets throughout pregnancy. In the first trimester, syncytiotrophoblasts were positive for CK7 and 13 along the basal membrane. As pregnancy progressed there was an increase in intensity of the reaction product and a more diffuse positive staining of CK7 in the cytoplasm of the syncytium, with evident positivity along the apical membrane. CK13 showed similar expression as CK7, but with less intense staining along the apical membrane and less prominent staining in the cytoplasm. Villous cytotrophoblasts were also positive for CK7 and CK13. CK17 was found related to cytotrophoblastic cells in contact with or next to fibrin deposits. Extravillous cytotrophoblasts in cell islands and cell columns were positive for CK13 only in the cell layers located proximal to the villous stroma, whereas the distal and more differentiated cells were negative. CK7 was positive in all epithelial cells of cell islands and columns, but the reaction product was not present in cells deeply migrated into the decidua. Amnion was negative for anti-CK13 antibodies in the first trimester but was positive at term. CK4 and CK16 were not found in the placenta. Our study shows for the first time that the different populations of human placental trophoblast express cytokeratins in developmental, differentiative, and functional specific patterns. These findings can be useful to distinguish and classify the various trophoblastic populations and provide a foundation for studying pathological aspects of the trophoblast.

Cell Differentiation↗

PubMed1995

Epithelial lung cell marker: current tools for cell typing.

This review discusses current immunohistochemical and lectin histochemical approaches to identify and to distinguish the different epithelial cell populations of the pulmonary tissue. Special emphasis is given to the characterization of pulmonary alveolar and bronchial epithelial cells and mesothelial cells. Structural proteins, membrane molecules and secretory products of the alveolar epithelium, which have already been characterized and which may be useful for monitoring the developmental or pathological processes, are listed and briefly described.

Animals↗

PubMed1995

Expression of a 130-kDa mesothelial and ciliated cell Ag (MCp130) in normal and developing human and rat lung and its role as a diagnostic marker for mesotheliomas and tumors of the female reproductive system.

BACKGROUND: Proteins in human lung lavage were analyzed to identify cell-specific markers for potential use in the study of the biology and pathology of pulmonary cells. EXPERIMENTAL DESIGN: Proteins associated with pulmonary surfactant were used to raise mAb. An Ab to a 130-kDa protein (MCp130) was reactive with ciliated and mesothelial cells. Expression of this Ag in normal organs, developing lung, and tumors was investigated. RESULTS: By Western blotting, the Ab stained a protein of about 130 kDa. In formalin-fixed, paraffin-embedded tissues from adult human and rat organs, the Ab specifically stained the luminal/apical surfaces of pulmonary and nonpulmonary ciliated and mesothelial cells. Staining of fetal airway cells was independent of ciliation. Airway cell staining was detectable in human fetal lungs at 12 weeks of gestation and at Day 18 of gestation in fetal rat. The Ab reacted with human and rat fetal mesothelial cells at the gestational ages of 15 weeks and 17 days, respectively. It also stained ciliated cells in endosalpinx and endometrium. Human epithelial mesotheliomas and ovarian and endometrial carcinomas stained selectively, whereas other pulmonary tumors and tumors of other organs did not react with the Ab. CONCLUSIONS: This 130-kDa mesothelial and ciliated cell plasma membrane protein appears in developing lung at an earlier age than secretory proteins. The marker is of potential use in the study of development of the different cell lineages in the lung and female reproductive tract. The Ab is expected to be useful in the diagnosis of epithelial mesotheliomas and ovarian/endometrial carcinomas, because it selectively stains these tumors and is reactive with formalin-fixed, paraffin-embedded tissues.

Adult↗

PubMed1994

Simultaneous determination of L-693,612, a topical carbonic anhydrase inhibitor, and two potential metabolites in human whole blood by ion-pair high-performance liquid chromatography.

A method for the simultaneous determination of a topical carbonic anhydrase inhibitor, L-693,612, and two of its potential metabolites in human whole blood is described. The analytes are isolated from the matrix via liquid-liquid extraction with a mixture of toluene, ethyl acetate and isopropanol (49:50:1, v/v/v). The analytes are then back extracted into dilute phosphoric acid prior to injection into the HPLC system. A cyano column (Zorbax SB-CN, 150 x 4.6 mm) with a mobile phase of phosphoric acid(0.085%)-acetonitrile (73.5:26.5) containing 10 mM sodium decane sulfonate and adjusted to pH 3 is used for the analysis. Detection is based on UV absorbance at 252 nm. The assay was found to be linear in the concentration range of 5-500 ng/ml for each analyte when 1-ml aliquots of whole blood were extracted.

Carbonic Anhydrase Inhibitors↗

PubMed1994

Immunohistological detection of the beta subunit of prolyl 4-hydroxylase in rat and mini pig lungs with radiation-induced pulmonary fibrosis.

Polyclonal and monoclonal antibodies to the beta subunit of prolyl 4-hydroxylase, the protein disulphide isomerase, were used to compare the pulmonary cells in 13 normal and in 20 fibrotic rat and mini-pig lungs made fibrotic by X-ray irradiation, using the ABC immunoperoxidase technique. In normal lungs, prominent staining of Clara cells and type II pneumocytes and weaker reactivity with alveolar macrophages, fibroblasts, endothelial and smooth muscle cells were detectable. In pulmonary disease, in which interstitial fibrosis was the characteristic feature, the immunoreactivity was increased in both the epithelial and interstitial cells. Type I pneumocytes remained negative. In the early stages of disease (3 to 4 weeks after irradiation) when little morphological alteration was seen, capillary endothelial cells had already become immunoreactive. These results underline the complex involvement and interaction of different lung cell populations in the process of pulmonary fibrogenesis.

Animals↗

PubMed1994

Localization of surfactant protein A (SP-A) in alveolar macrophage subpopulations of normal and fibrotic rat lung.

The colocalization of surfactant protein A (SP-A) and the alveolar macrophage markers ED1 and RM-1, as well as various lectins of the N-acetyl-galactosamine group [Maclura pomifera lectin (MPA), Dolichos biflorus lectin (DBA), soybean agglutinin (SBA)] and of the mannose group [Canavalia ensiformis lectin (ConA), Galanthus nivalis lectin (GNA)] was studied in normal and fibrotic rat lung tissues. In normal tissue, SP-A was located preferentially in the alveolar macrophage subpopulation lacking specific binding sites for lectins of the N-acetylgalactosamine group (DBA and SBA), although 50% of MPA-binding macrophages contained SP-A. The ED1-positive cells were SP-A-negative, whereas SP-A uptake could be detected among the RM-1 immunoreactive as well as the ConA and GNA binding macrophages. In fibrotic lung tissue, however, a small number of DBA and SBA binding macrophages contained SP-A and the percentage of GNA and ConA binding alveolar macrophages exhibiting SP-A immunoreactivity was reduced. Additionally, the number of ED1+/SP-A+ macrophages was found to be increased. Immunoelectron microscopy revealed accumulation of SP-A in the extracellular space. The differing SP-A content in different alveolar macrophage subpopulations suggests a more complex mechanism of uptake and degradation of surfactant proteins in normal and pathological conditions, which cannot simply be explained by the glycoconjugate pattern on the surface of alveolar macrophages.

Animals↗

PubMed1994

Immunohistochemical detection of tissue factor (TF) on paraffin sections of routinely fixed human tissue.

Tissue factor (TF), a 47 kDa transmembrane glycoprotein, is the essential receptor and cofactor for factor VII/VIIa. Its distribution in normal tissues and in tumours has been recently investigated immunohistochemically with monoclonal and polyclonal anti-TF antibodies in frozen sections. The cardinal problem of this technique is the difficulty of determining exactly the localization of the reaction product at least in certain tissues. Here, we demonstrate a method using monoclonal anti-TF antibodies to detect TF in routinely fixed, microwaved, paraffin-embedded tissues. Generally, there were no fundamental differences in TF distribution in frozen and paraffin-embedded material. However, in most cases, the paraffin sections allow a better cellular localization of TF. For example, the staining pattern for TF in both kinds of sections is identical in kidney, brain and skin. The paraffin-embedded material, however, clearly shows that TF expression is restricted to the parietal and the visceral epithelia of Bowman's capsule of glomeruli in the kidney, and to astrocytes and their processes in the brain. TF reactivity in the skin is revealed to be cell membrane-bound; in cardiomyocytes TF shows an exclusively sarcolemmal localization. The immunohistological detection of TF in paraffin sections is a powerful tool for systematic studies on the possible role of TF in the context of physiological and pathological studies.

Antibodies, Monoclonal↗

PubMed1994

Colocalization of cytokeratin 18 and villin in type III alveolar cells (brush cells) of the rat lung.

Alveoli of the rat lung are lined by three different cell types, the flat type I cells and the cuboidal type II and type III cells. Type III cells differ from type II cells by the presence of an apical tuft of microvilli and the absence of lamellar type secretory granules. In the present study we show by double immunolabelling that type III cells of the rat lung can be identified at the light- and electron microscope level by antibodies against both cytokeratin 18 and the actin-crosslinking protein villin. At the ultrastructural level, microvilli and their rootlets in the apical cytoplasm were labelled by the anti-villin antibodies, whereas a monoclonal antibody against cytokeratin 18 (Ks18.04) labelled bundles of intermediate filaments. In conclusion, antibodies against villin and certain monoclonal antibodies specific for cytokeratin 18 can be used as tools for selective visualization of type III cells in the rat lung.

Animals↗

PubMed1994

Species differences in lectin binding to pulmonary cells: Soybean agglutinin (SBA) as a marker of type I alveolar epithelial cells and alveolar macrophages in mini pigs.

We compared lectin staining patterns in rat and mini pig tissues of normal and fibrotic (irradiation-induced) lungs. Two lectins were studied: Dolichos biflorus (DBA) and Soybean (SBA). Both lectins strongly stained a subpopulation of alveolar macrophages. In the rat, DBA positive macrophages were a subpopulation of the SBA binding cells. In mini pig lungs, a further specific binding of DBA and SBA was observed: DBA reacted with endothelia, and SBA stained the alveolar type I cells. Double immunofluorescence experiments using a type II cell-specific cytokeratin antibody confirmed the selective reactivity of SBA with type I cells, which was also present in fibrotic areas with epithelial cell proliferation.

Animals↗

PubMed1994

Modulation of pan-cadherin expression in alveolar epithelial cells of mini pigs with pulmonary fibrosis.

The expression of pan-cadherin was investigated immunohistochemically in normal and irradiated mini pig lungs. Using a double labelling immunofluorescence technique, pan-cadherin expression was also compared with that of cytokeratin 18, which is selectively present in type II cells. In untreated animals pan-cadherin was detected in type I pneumocytes, in alveolar macrophages and in endothelial cells of larger blood vessels. Radiation caused increased pan-cadherin immunoreactivity of bronchial epithelial cells and interstitial cells. In addition, pan-cadherin expression was induced in type II pneumocytes. These changes in the distribution of epithelial cadherin molecules may implicate a role of cadherins for epithelial remodeling in response to radiation-induced lung injury.

Animals↗

PubMed1994

Immunohistochemical localization of the beta subunit of prolyl 4-hydroxylase in human alveolar epithelial cells.

The beta subunit of prolyl 4-hydroxylase, the protein-disulfide isomerase (PDJ), catalyzes the hydroxylation of proline residues of collagens and proteins with collagen-like structure, a step essential for the folding of the procollagen chains to form triple-helices. In the present study, we report the selective immunohistological localization of PDI in type II alveolar and bronchial epithelial cells. The detection of the hidden antigen with the monoclonal antibody 5B5 is usually not successful in paraffin sections but was possible after microwave pretreatment of tissue sections. In cases of severe lung injury (fibrosing alveolitis) enhanced immunoreactivity was found for this enzyme in epithelial, endothelial as well as interstitial cells and in alveolar macrophages. The results indicate a possible involvement of the pulmonary epithelial cells in the upregulation of collagen production during the process of fibrosis.

Antibodies, Monoclonal↗

PubMed1994

Bauhinia purpurea lectin (BPA) binding of rat type I pneumocytes: alveolar epithelial alterations after radiation-induced lung injury.

In the rat lung, we found that the Bauhinia purpurea lectin (BPA) specifically binds to the type I alveolar epithelial cells and to the alveolar macrophages. Double label fluorescence employing FITC-coupled Maclura pomifera lectin (MPA) and bBPA-avidin-Texas Red showed that BPA binding was confined to type I cells. In addition, a minor staining of the luminal border of the terminal bronchiolar epithelium was found. The sequence of tissue injury following X-radiation was examined in rats. BPA is a suitable marker which indicates epithelial changes during the early stage of pneumonitis and the subsequent development of fibrosis.

Animals↗

PubMed1994

A set of early-born neurons is distinctly labeled by several defined antibodies in the adult rabbit retina.

Retinal ganglion cells, cone photoreceptor cells, and horizontal cells arise earlier in ontogenesis than the other retinal cell types. Although during the first postnatal week of life much cell proliferation occurs in the rabbit retina, 3H-thymidine labeling shows that these particular neurons are already postmitotic in neonatal animals. We show here that, in the adult retina, these early-born neurons express antigens as neuron-specific enolase, HNK-1 epitope of N-CAM, and PGP 9.5 antigen, which are not expressed by the neurons later born. It is concluded that the mammalian retina contains two genotypically different sets of neuronal cells which can be distinguished by immunocytochemistry.

Aging↗