Magnesium sulfate prevents atrial tachyarrhythmias after cardiac and non-cardiac surgery--what is the common mechanism?
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Atrial Fibrillation↗
Biomedical subjects
H Grossmann
Publications and source records attributed to H Grossmann.
[The Board--a nightmare or a necessary aid to professionalism?].
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Governing Board↗
Upregulation of gap junction protein connexin43 in alveolar epithelial cells of rats with radiation-induced pulmonary fibrosis.
The degree of immunoreactive connexin43 (C x 43) in rat lung was evaluated during the development of radiation-induced pulmonary fibrosis in rat by a double immunofluorescence technique using polyclonal antisera to Cx43 and monoclonal antibodies to cytokeratins on cryostat sections. In normal rat lungs, Cx43 was detected in pneumocytes type II and I, in large blood vessel endothelia, in peribronchial smooth muscle cells, and in some peribronchial and perivascular interstitial cells. As early as 1 week after irradiation, enhanced immunoreactivity for Cx43 in the epithelial cells was detected. In severely injured lungs (about 3 months after irradiation), Cx43 was found also in the cytoplasm of type II pneumocytes. These findings were confirmed by western blot data. Western blot analysis also revealed increased phosphorylation of Cx43. It remains to be investigated whether the increased content of Cx43 in irradiated rat lung may be due to an enhanced number of gap junctions between type I and II alveolar epithelial cells.
Actins↗
Tissue factor expression during human and mouse development.
In the adult organism the cellular distribution of tissue factor (TF) expression corresponds to biological boundary layers forming a hemostatic barrier ready to activate blood coagulation after tissue injury. Whether TF expression might also play a role in development is unknown. To determine the significance of TF in ontogenesis, we examined the pattern of TF expression in mouse development and compared it with the distribution of TF in human post-implantation embryos and fetuses of corresponding gestational age. At early embryonic periods of murine (6.5 and 7.5 pc) and human (stage 5) development, there was strong expression of TF in both ectodermal and entodermal cells. In situ hybridization and immunohistochemistry demonstrated that TF mRNA and protein were expressed widely in epithelial areas with high levels of morphogenic activity during organogenesis. Staining for TF was seen during ontogenetic development in tissues such as epidermis, myocardium, bronchial epithelium, and hepatocytes, which express TF in the adult organism. Surprisingly, during renal development and in adults, expression of TF differed between humans and mice. In humans, maturing stage glomeruli were stained for TF whereas in mice, TF was absent from glomeruli but was present in the epithelia of tubular segments. In neuroepithelial cells, there was a substantial expression of TF. Moreover, there was robust TF expression in tissues such as skeletal muscle and pancreas, which do not express it in the adult. In contrast, expression of the physiological ligand for TF, factor VII, was not detectable during early stages of human embryogenesis using immunohistochemistry. The temporal and spatial pattern of TF expression during murine and human development supports the contention that TF serves as an important morphogenic factor during embryogenesis.
Adult↗
Immunohistochemistry of new type I alveolar epithelial cell markers of the rat.
The presence of pan-cadherin and the MEP-I antigen in normal and diseased rat lung was established by employing immunoperoxidase and double label fluorescence techniques. The binding of a mouse monoclonal antibody (MEP-1) reacting specifically with type I pneumocytes was assessed on paraffin sections of normal specimens as well as those with pulmonary fibrosis induced by bleomycin or radiation treatment. In injured alveolar epithelium, a diminished type I cell and a focal type II cell immunoreactivity was found. Electron microscopy of immunogold-labelled lung tissue confirmed the type I cell specificity of MEP-1. In severely injured pulmonary parenchyma MEP-1-negative areas occurred, which were also negative with the type II pneumocyte marker Maclura pomifera lectin. Similarly, a polyclonal pan-cadherin antibody uniformly decorated luminal surfaces of alveoli except the type II pneumocytes. Furthermore, pleural mesothelial cells, bronchiolar epithelial cells, endothelial cells of large blood vessels and alveolar macrophage surfaces exhibited pan-cadherin immunoreactivity. After injury, a remarkable loss of pan-cadherin immunoreactivity in the MEP-1-positive type I epithelial cells was detectable. These findings suggest that characterization of normal alveolar epithelial cells and monitoring of the epithelial remodelling in pulmonary pathohistology are sufficiently described by the antibodies MEP-1 anti pancadherin.
Animals↗
Detection of circulating tissue factor and factor VII in a normal population.
The plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 +/- 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 +/- 15% and the factor VIIag was 0.77 +/- 0.19 microgram/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.
Adolescent↗
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↗
Disseminated histoplasmosis in chronic mucocutaneous candidiasis.
Chronic mucocutaneous candidiasis (CMC) is rarely associated with disseminated Candida, but is often associated with systemic infection secondary to other organisms [1]. A 6-year-old with CMC and disseminated histoplasmosis is presented here.
Candidiasis, Chronic Mucocutaneous↗
Immunohistological detection of tissue factor in normal and abnormal human mammary glands using monoclonal antibodies.
Tissue factor (TF) is the primary cell-bound initiator of the coagulation protease cascade. The cytological distribution of TF in various tissues may be described on the basis of immunohistochemistry with epitope-defined monoclonal antibodies and the extravascular distribution of TF apparently represents a haemostatic envelope ready to activate coagulation when vascular integrity is disrupted. The present study localized TF in human breast cancer tissues when compared with normal breast gland tissues and benign disorders of the mammary gland. By use of a cocktail of three epitope-defined monoclonal antibodies, TF was detected only in the myoepithelia of the resting breast gland. In proliferating disorders like fibrocystic disease or in fibroadenomas, both myoepithelia and luminal epithelia showed TF expression. Of 115 breast cancers 93 reacted with anti-TF, in an inhomogeneous manner in terms of intensity and number of positive cells. There was a tendency for more positive and intensely stained cells to be found in well-differentiated structures such as tubules. Invasive ductal carcinomas exhibiting more positive and more strongly stained cells were less commonly metastatic to lymph nodes when compared with the tumours with no detectable or very low TF immunostaining. A semi-quantitatively recorded score of TF immunostaining correlated with the procoagulatory activity measured (7 fibroadenomas and 24 carcinomas). The results of this study suggest that proliferation and differentiation of the mammary gland is associated with enhanced TF expression in the epithelia which are negative for TF staining in the resting gland. Malignant growth is characterized by randomly expressed epithelial TF, which expression is enhanced and more frequent in well-differentiated tumour cells.
Antibodies, Monoclonal↗
An ELISA for tissue factor using monoclonal antibodies.
Whereas tissue factor, a high-affinity cell-surface receptor and essential cofactor for the serine protease factor VII is constitutively present in certain tissues such as epithelial tissue, brain and placenta, it is not normally expressed by cells within the vasculature. However, the stimulation of monocytes and endothelial cells by a variety of inflammatory and immunological reactions results in the induction of cell surface tissue factor (TF) expression. TF is also expressed on tumour cells, and may play a role in tumour growth and metastasis formation. To examine the role of TF in these processes we developed monoclonal antibodies to human tissue factor apoprotein. The antibodies were characterized by neutralization of the procoagulant activity and by immunoblotting. With two of these monoclonal antibodies a sandwich ELISA was developed for the rapid quantitation of TF. The sensitivity of the assay permits extensive studies involving the modulation of TF expression on small numbers of cells. The results are comparable to the functional clotting assay as evaluated with unpurified TF and with the tumour cell line MCF-7. For certain applications, monitoring of cellular TF expression by ELISA using anti-TF monoclonal antibodies is preferable because it is not influenced by other coagulation factors or by inhibitors of procoagulant activity on the cells.
Animals↗
[He who ventures will win. Nursing education for foreign born].
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Education, Nursing↗
Production and characterization of monoclonal antibodies against carcinoembryonic antigen (CEA).
In the experiments presented here 22 monoclonal antibodies (MoAbs) were produced which reacted with the tumor marker carcinoembryonic antigen (CEA). Eleven of the MoAbs reacted neither with peripheral blood granulocytes nor with purified spleen NCA-60 kDa and were therefore regarded as "CEA-specific". Only three antibodies of this group reacted exclusively with CEA-180 kDa. Eight MoAbs reacted with CEA-180 kDa and with CEA-like substances of lower molecular mass (of 160 kDa and/or 120 kDa) present in colon carcinoma cells as determined by immunoblotting. These molecules seem to be different from the classical non-specific cross-reacting antigens (NCAs) present in peripheral blood granulocytes. In contrast to that, the other 11 anti-CEA MoAbs recognized in addition to CEA-180 kDa also NCAs on granulocytes. Six of them were reactive with a purified spleen NCA-60 kDa preparation. These MoAbs bound also to reduced and alkylated CEA-180 kDa (CEA r/a), i.e. they recognize sequential epitopes. All 22 MoAbs reacted with CEA expressed in different human tumor cell lines as determined by immunocytological analysis. But six of them did not bind to the surface of these cells when tested in a radioimmuno-binding assay. It was concluded that the epitope(s) recognized by these antibodies are involved in cell membrane anchoring of the CEA-molecules.
Antibodies, Monoclonal↗
Induction of thyroid neoplasms in the rat. A histochemical, immunohistochemical, autoradiographic and ultrastructural study.
Papillary carcinomas of the thyroid gland induced in rats by combined methylthiouracil (MTU)/nitrosomethylurea treatment were studied electron microscopically and histochemically for their acid phosphatase activity, radioactive iodine uptake and for their thyroglobulin synthesis. The papillary carcinomas accumulated radioactive iodine, synthesized thyroglobulin and showed a perinuclear localization of acid phosphatase activity in the cytoplasm. After omitting the reactive thyrotropic effect (cessation of MTU administration) a decrease of both iodine organification and acid phosphatase activity was observed. The synthesis of thyroglobulin was also reduced. The changes in the ultrastructure of tumour cells corresponded to the respective functional activities. The results suggest that the papillary carcinomas may have a functional dependence on thyroid-stimulating hormone.
Acid Phosphatase↗
[Immunohistochemical detection of thyroglobulin].
An antiserum against human thyroglobulin isolated by gelfiltration from the human thyroid gland was raised in rabbits. The specificity of the antiserum to detect human thyroglobulin was determined by an immunoperoxidase technique on formalin-fixed and paraffin-embedded tissue sections of 17 primary thyroid carcinomas and 80 carcinomas of other origins, such as pancreas, colon, breast, bladder, ovary, testis, and larynx. Positive reactions to immunological staining were recorded only from differentiated thyroid carcinomas, while no reactions were exhibited by the other malignant tumours tested in this study.
Adenocarcinoma↗
Analysis of carcinoembryonic antigen determinants by monoclonal antibodies and lectins.
Two out of five determinants recognized by monoclonal antibodies (MoAbs) on carcinoembryonic antigen (CEA) were analyzed by blocking the CEA-MoAb interaction with 9 different lectins in a solid phase radioimmunoassay. Two batches of CEA were first studied for their binding to lectins at the solid phase. Lotus, soybean and wheat germ lectins were most active, but the reaction pattern was different with the two CEA batches. The corresponding sugars were capable of inhibiting the lectin-CEA binding. MoAbs were fixed to the solid phase, and their reaction with CEA was tried to be blocked by preincubating the antigen with lectins. Lotus lectin and wheat germ agglutinin were clearly blocking the MoAb-CEA interaction, but this was strikingly dependent on the CEA batch used and the particular CEA determinant investigated. These reactions could not be blocked by sugars. The data provide evidence for a role of sugars in the sterical configuration of CEA determinants. In view of the heterogeneity of the findings, however, the conclusion is drawn that the protein moiety plays the more important role in the configuration of the CEA determinants studied.
Antibodies, Monoclonal↗
A human lymphokine released by mononuclear blood cells upon contact with CEA.
As revealed by the macrophage electrophoretic mobility (MEM) technique mononuclear blood cells from certain cancer patients respond to carcinoembryonic antigen (CEA). This phenomenon appeared to be due to a specific lymphokine release. In this study, the lymphokine activity of supernatant pools was stepwise enriched by gel filtration on Sephadex. The mediator activity was recovered within a molecular mass region less than 47 kDA. The lymphokine was highly enriched during further gel filtration steps and showed a single activity peak in the molecular mass region of 23.5 kDa. Gel filtrations of appropriate control supernatants resulted in biologically inactive fractions. The lymphokine was heat-labile at 56 degrees C, showed a clear-cut, dose-dependent effect on macrophages, and could be blocked by fucose. Preparative gel electrophoresis of radiolabeled and unlabeled lymphokine resulted in two corresponding peaks of biological activity and radioactivity.
Carcinoembryonic Antigen↗
[Laboratory experiment studies on quantitative blood flow measurement with the continuous-wave ultrasound Doppler procedure: I. Transducer evaluation].
Cw-Doppler transducers designed for volume blood flow measurement were evaluated experimentally. Both sensitivity plotting using a ball point reflector and comparative volume flow measurement on a flow-rig using EMF as reference method evidenced unequal sensitivity along the transducer. With increasing distance to the transducer the longer axis of the oval sound field assumed an orientation perpendicular to the longer axis of the active transducer surface. Sensitivity decreased from the centre of the sound field to its periphery. Differences of more than 2 mm between the length of the transducer and the diameter of the latex tube resulted in over- or underestimations of volume flow. Underestimations found with transducers longer than the tube diameter were interpreted as resulting from the increased contribution of stable echoes to the signal.
Blood Flow Velocity↗
[Laboratory experimental studies on quantitative blood flow measurement with the c.w. ultrasound Doppler procedure: II. Flow measurements].
The reliability of Doppler blood flow measurement was examined by testing a cw Doppler flowmeter on a flow-rig. Comparing the Doppler measurements with those simultaneously obtained by means of EFM, the correlation coefficient was found to be 0.989 for continuous, and 0.985 for pulsatile streaming. With velocities up to 40 cm/sec there was a systemic overestimation of flow velocity which was attributed to the effects of the high pass filter used. Unequal distribution of intensity within the sound field is discussed. Systemic underestimation of velocities over 45 cm/sec is due to the interaction of the low pass filter. Identification of the 90 degrees reference angle using the cw Doppler technique seems to be appropriate. Within zones of turbulence caused by eccentric stenoses no reliable flow values could be determined.
Blood Flow Velocity↗