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E W Rauterberg

Publications and source records attributed to E W Rauterberg.

At least 19 recordsLinked to original sources
PubMed1991

Immunohistology of temporal arteritis: phenotyping of infiltrating cells and deposits of complement components.

Deposition of complement factors, immunoglobulins and infiltrating cells was evaluated by immunohistochemical staining in 30 temporal artery biopsy specimens from patients suffering from temporal arteritis and/or polymyalgia rheumatica and in controls. In the temporal arteritis group infiltrating cells, classic complement, alternative complement and lytic complex activation were detected. In specimens from patients suffering from only polymyalgia rheumatica there was unexpected evidence of classic complement and lytic complex activation. We conclude that immuno-histochemistry provides support for the concept of temporal arteritis and polymyalgia being based on the same pathological process.

Biopsy↗
PubMed1991

Expression of 1,25-dihydroxyvitamin D3 receptors in normal and psoriatic skin.

Increasing evidence suggests an immunoregulatory function of the potent steroid hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) which has been successfully applied for treatment of psoriasis. The skin is both a site of production and a target of 1,25(OH)2D3. In vitro, 1,25(OH)2D3 inhibits proliferation and stimulates differentiation of keratinocytes. We investigated the in situ expression of vitamin D-receptors (VDR) in normal and psoriatic skin by immunochemical methods. The VDR were visualized using the monoclonal antibody (MoAb) 9A7g to the VDR and the labeled avidinbiotin technique. Immunoreactivity was consistently confined to nuclei in all skin biopsies. In normal skin specimens (n = 10) VDR antigens were expressed in keratinocytes of all epidermal layers (except those of the stratum corneum) and in cells of the epidermal appendages. Double labeling experiments with MoAb to cluster-defined antigens indicated that melanocytes and approximately 75% of Langerhans cells exhibit 1,25(OH)2D3 receptors in normal skin biopsies (n = 5). Depending on their localization in skin compartments 42-62% of CD11b+ positive macrophages and 45-75% of CD3+ T lymphocytes expressed VDR. Non-lesional psoriatic skin specimens (n = 8) revealed nearly identical staining patterns. Lesional psoriatic skin specimens (n = 8) exhibited a significant increase of VDR expression both in basal and suprabasal epidermal layers as measured by computer-assisted morphometry and showed a remarkable change of the immune cell pattern: the densitity and proportion of VDR positive T lymphocytes and macrophages were higher in the epidermal and the perivascular papillary loop compartment. These in vivo findings strongly support the hypothesis that 1,25(OH)2D3 modulates immune response and cell proliferation/differentiation in human skin.

Adult↗
PubMed1991

Cysteinyl leukotriene actions on the microcirculation of the normal and split hydronephrotic rat kidney.

The effects of leukotriene D4 (LTD4) and leukotriene E4 (LTE4) on renal microcirculation were determined on normal and hydronephrotic female Wistar rats. In normal kidneys, the effects of LTD4 on total renal blood flow and glomerular filtration rate were measured by a flow meter and by inulin clearance. In the split hydronephrotic kidney, the LTD4- and LTE4-mediated vascular effects were localized by intravital microscopy. Intravenous infusion of low-dose LTD4 (1 x 10(-9) mol min-1 kg-1) over 15 min induced a strong decrease in renal blood flow (-43% and -70%) in the normal and the hydronephrotic kidney. After the infusion the glomerular filtration rate of the normal kidney was significantly reduced by 65% and the filtration fraction by 32%. The fall in filtration fraction is in accordance with the significant decrease in luminal diameters of the arcuate artery (-28%) and the proximal interlobular artery (-12%) in the hydronephrotic kidney under LTD4. The decrease in renal blood flow, glomerular filtration rate, filtration fraction and luminal diameters persisted in the normal as well as in the hydronephrotic kidney for more than 60 min beyond cessation of infusion. Local application of LTD4 (1 x 10(-10) mol l-1 up to 1 x 10(-7) mol l-1) and LTE4 (1 x 10(-10) mol l-1 up to 1 x 10(-8) mol l-1) induced a dose-dependent constriction of the arcuate artery and the proximal interlobular artery. The distal interlobular artery, the afferent and the efferent arteriole were not significantly affected by LTD4 or LTE4. The glomerular blood flow was dose-dependently reduced up to 48% under local LTD4 and 43% under LTE4. The LTD4/LTE4 antagonist FPL 55712 (1 x 10(-8) mol min-1 kg-1, iv) significantly attenuated the effects of LTD4 infusion and local LTE4 application in the hydronephrotic kidney. This is indicative of the presence of receptors for LTD4 and LTE4 in the larger preglomerular vessels of the rat kidney. The LTD4 effects on the normal kidney were attenuated by simultaneous infusion of dopamine (5 microgram min-1 kg-1) or plasma expansion, two principal methods in the treatment of acute renal failure. The results in the normal and hydronephrotic kidney demonstrate a preferential preglomerular vasoconstriction under LTD4 and LTE4 causing a marked decrease in renal and glomerular blood flow, glomerular filtration rate and filtration fraction.

Animals↗
PubMed1991

Complement in inflammation: induction of nephritides and progress to chronicity.

The C5b-9 complex has a dual role as a factor involved in the initiation of nephritides and in the progress to chronicity and sclerosis. The unique pathophysiology of the membrane attack complex, distinct from other mediators, is its independence from specific receptors. It inserted in any membrane lipid bilayer tested so far.

Animals↗
PubMed1990

Several epitopes on native human complement C9 are involved in interaction with the C5b-8 complex and other C9 molecules.

Ten monoclonal antibodies (mAb) against native human C9 exhibiting various inhibitory effects on the hemolytic activity of C9 (Bausback, J., Kontermann, R. and Rauterberg, E. W., Immunobiology 1988. 178: 58) were further analyzed regarding their reactivities with monomeric C9 (mC9), polymerized C9 (pC9), and the non-lytic SC5b-9 complex in enzyme-linked immunosorbent assay and with the membrane attack complex (MAC) generated on rabbit erythrocytes analyzed by flow cytometry. In addition, the inhibitory effects of mAb on zinc-induced C9 polymerization were investigated. One epitope of the C-terminal half of C9b exposed on the surface of pC9 and the MAC seems not to participate directly in lytic function or polymerization since no inhibitory effect of the respective mAb was observed. The nine other mAb directed against epitopes of the C9a part exhibit various inhibitory potentials. The mAb inhibit either hemolysis or polymerization, or both processes. Due to the reactivity with the tested antigens the mAb can be divided into two groups. mAb of the first group bind with nearly the same affinity to all four antigens, whereas mAb of the second group react preferentially with mC9 while their affinity to pC9, SC5b-9 and the MAC is reduced. Comparison of reaction patterns and inhibitory effects strongly suggest that different epitopes on the surface of native C9 are involved in interaction of C9 with C5b-8 and/or in C9-C9 interaction. The finding that mAb inhibiting polymerization of C9 in vitro have no inhibitory effect on hemolysis confirms that C9 polymers are no prerequisite for lysis.

Antibodies, Monoclonal↗
PubMed1990

Fluid phase generation of terminal complement complex as a novel index of bioincompatibility.

Blood membrane interactions in hemodialysis have been shown to trigger complement (C) activation. As indicators of C-activation the anaphylatoxins (C3a and C5a) are problematical because of methodological difficulties and their kinetic properties. We developed a sensitive and specific micro-ELISA using a monoclonal antibody against neoantigens on the terminal complement complex (TCC); highly purified human TCC served as standard. Concentrations of TCC were measured in single-path perfusion systems (in vitro) and in the blood lines (arterial inlet; venous outlet) of patients on hemodialysis using steam-sterilized or ETO-sterilized dialyzers with the following membranes: cuprophan (CU), hemophan (HE) and polysulfone F6 (PS), respectively. All dialyzers with identical geometry were run under identical conditions. All membranes tested caused continuously ongoing net generation of TCC. In vitro, contact of serum with CU minidialyzers resulted in fivefold higher net release of TCC compared with HE and PS. In vivo TCC concentration-time profiles differed significantly between membranes in the rank order CU much much greater than HE greater than PS (mean basal concentration 58 x 10(-11) M; peak increase over baseline with CU 40-fold, HE fourfold, PS threefold). In addition, more TCC was generated from the same dialyzers with ETO than steam sterilization. TCC differed from C3a and C5a in the following respects: (i) lower detection limit (4 x 10(-11) vs. less than 5 x 10(-9) M for both C-anaphylatoxins); (ii) higher relative increment (inlet) during CU dialysis (25-fold vs. eightfold and twofold, respectively); (iii) C-anaphylatoxins yielded the same ranking (CU much greater than HE greater than PS), but TCC concentrations were not a linear function of C3a or C5a concentrations, respectively. Kinetic analysis (Bateman function) showed significant differences of invasion constants between membranes, that is, CU 0.088 min-1, HE 0.09, PS 0.168. The net amount of TCC released from the dialyzer was calculated under certain assumptions. It was 75.5 mg/4 hr for CU, 7.3 for HE and 5.0 for PS. The elimination constant was also dependent on the type of membrane. Using flow cytofluorometry and immunohistochemical methods (APAAP), TCC was demonstrated on membranes of granulocytes obtained during dialysis; this is compatible with potential in vivo cell activation. Generation of PGE2 and TNF alpha by adherent monocytes induced by cuprophan was C8 dependent: levels were significantly increased by addition of C8 to C8 deficient human serum concomitantly with generation of TCC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Phototoxic erythema following PUVA treatment: independence of complement.

The effect of PUVA treatment on normal human serum (NHS), on isolated PMN, or on C3-deficient guinea pigs and congenic (C3-competent) control animals was tested. At a concentration of 0.1 or 1 mM/l 8-MOP and UVA doses of 5-30 J/cm2, PUVA failed to induce any detectable C3-cleavage in NHS. Furthermore, when the complement (C) activation in NHS had been induced before or after PUVA treatment by various methods. PUVA did not modulate the extent of C3-cleavage. PUVA did not affect the viability of isolated PMN, nor did it induce a release of LDH or elastase. No differences between C3-deficient and C-competent guinea pig skin exposed to PUVA were observed in erythema or histologic responses. Immunohistologic examination of specimens from normal guinea pigs revealed C3b and C3d deposits on necrotic keratinocytes, findings restricted to the PUVA-treated areas. Necrosis of keratinocytes was present in skin specimens of C3-deficient animals from PUVA-treated sites to a similar extent. However, deposits of C3-related antigens were completely absent there. From these observations, we suggest that the induction of phototoxic erythema following PUVA treatment is independent of complement.

Animals↗
PubMed1990

Assembly of terminal SC5b-9 complement complexes: a new index of blood-membrane interaction.

Activation of the complement system during the course of hemodialysis was recognized more than 20 years ago and since then the generation of C3a and C5a desarg has been used as parameters of blood-membrane interaction. More recently, determination of terminal C5b-9 complement complexes has become feasible. In the present study we determined plasma concentrations of C5b-9 complexes during hemodialysis using Cuprophan or Hemophan membranes. As early as 10 min into dialysis, Cuprophan membranes led to higher arterial plasma concentrations of C5b-9 complexes in comparison to Hemophan-containing devices. With Cuprophan, systemic arterial peak values of 237 +/- 27 U/ml were reached 45 min after the onset of dialysis, while corresponding peak values using Hemophan were only 58 +/- 16 U/ml. Venous concentrations of C5b-9 complexes, measured at the outlet of the dialyzer, were 489 +/- 102 U/ml with Cuprophan and 77 +/- 19 U/ml with Hemophan dialyzers. As an index of red cell lysis, plasma levels of free hemoglobin were evaluated. There was hemolysis with both membranes. Free hemoglobin levels increased threefold with Cuprophan and only twofold with Hemophan membranes. Taken together, plasma concentrations of C5b-9 complexes clearly discern between dialysis membranes of high or low compatibility. The fact that there is simultaneous lysis of red cells might indicate that deposition of C5b-9 complexes on innocent cells occurs which would lead subsequently to an array of diverse pathophysiological reactions.

Adult↗
PubMed1989

Distribution of c-myc, c-myb, and Ki-67 antigens in interphase and mitotic human cells evidenced by immunofluorescence staining technique.

Using specific antibodies and the immunofluorescence staining technique we found a similar subcellular distribution pattern of the cellular proto-oncogene proteins c-myc and c-myb in interphase and mitotic HL60 and Molt4 cells. Antibodies against c-myc as well as those against c-myb protein gave rise to a nuclear staining excluding the nucleoli. In mitotic cells both proteins are apparently not associated with the chromatin of the condensed chromosomes, but appear diffusely distributed throughout the cytoplasm. In contrast, immunostaining using the proliferation marker antibody Ki-67 yielded in both cell lines several prominent specks in the nucleus and a weak finely dispersed staining throughout the nucleoplasm. No fluorescence was detectable in the cytoplasm. In dividing cells Ki-67 immunofluorescence was found to be associated with the surface of the chromosomes. The functional significance of the different localizations of the proteins is discussed in light of what is currently known about nuclear antigens.

Antigens, Surface↗
PubMed1989

N-deglycosylation of human complement component C9 reduces its hemolytic activity.

The effect of enzymatic deglycosylation of human complement component C9 on its hemolytic activity was investigated. Treatment of native C9 (Mr 71,000) with glyocpeptidase F (PNGase F) results in a stepwise decrease of the mol. wt. The formation of an Mr 67,000 peptide which is further converted to Mr 63,000 suggests that there are two N-linked carbohydrate chains per C9 polypeptide. Removal of approximately 88% of the N-linked oligosaccharides results in 80% reduction of the hemolytic activity (CH50). The completely N-deglycosylated Mr 63,000 peptide contains a remaining amount of 25% of the total carbohydrates of native C9. These glycans are assumed to be O-linked and predominantly attached to the C9a part of C9. The electrophoretic mobility of C9 is not affected by endoglycosidase F or H treatments revealing that the two N-linked glycans are of the tri- or tetra-antennary complex type. Cleavage of terminal sialic acids from native C9 by neuraminidase results in an Mr 67,000 product with nearly unaltered hemolytic activity. In contrast to other glycoproteins in which deglycosylation remained without major effects on their functional activity, our findings suggest that the N-linked carbohydrates are required for full expression of hemolytic activity of C9.

Amidohydrolases↗
PubMed1989

Detection of human autoantibody against intercalated cells of kidney-collecting tubule.

Serum from a 24-year-old woman with a history of habitual abortions was examined for autoantibodies by indirect immunofluorescence microscopy. Fluorochrome-labelled antibodies to IgG revealed cytoplasmic staining of single cells in rat kidney collecting and connecting tubules. An identical staining pattern was reproducibly obtained in human and rabbit kidney, pointing to a cytoplasmic antigen concentrated in the apical pole of these cells. Lectin-binding histochemistry and immunohistochemical experiments using markers for different cell populations of the renal collecting tubule by double immunofluorescence technique, identified the cells recognized by the autoantibody as intercalated cells (ICC). Remarkably, this autoantibody reacted with a different antigen from those described to date in ICC, as evidenced by distribution and intracellular localization. The pattern of immunostaining suggests that all ICC are recognized in total rather than only one subpopulation. The connection between habitual abortions and this novel autoantibody are discussed.

Abortion, Habitual↗
PubMed1989

Identification and regulation of 1,25-dihydroxyvitamin D3 receptor activity and biosynthesis of 1,25-dihydroxyvitamin D3. Studies in cultured bovine aortic endothelial cells and human dermal capillaries.

Because 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has been shown to play roles in both proliferation and differentiation of novel target cells, the potential expression of 1,25(OH)2D3 receptor (VDR) activity was investigated in cultured bovine aortic endothelial cells (BAEC). Receptor binding assays performed on nuclear extracts of BAEC revealed a single class of specific, high-affinity VDR that displayed a 4.5-fold increase in maximal ligand binding (Nmax) in rapidly proliferating BAEC compared with confluent, density-arrested cells. When confluent BAEC were incubated with activators of protein kinase C (PKC), Nmax increased 2.5-fold within 6-24 h and this upregulation was prevented by sphingosine, an inhibitor of PKC, as well as by actinomycin D or cycloheximide. Immunohistochemical visualization using a specific MAb disclosed nuclear localized VDR in venular and capillary endothelial cells of human skin biopsies, documenting the expression of VDR, in vivo, and validating the BAEC model. Finally, additional experiments indicated that BAEC formed the 1,25(OH)2D3 hormonal metabolite from 25(OH)D3 substrate, in vitro, and growth curves of BAEC maintained in the presence of 10(-8) M 1,25(OH)2D3 showed a 36% decrease in saturation density. These data provide evidence for the presence of a vitamin D microendocrine system in endothelial cells, consisting of the VDR and a 1 alpha-hydroxylase enzyme capable of producing 1,25(OH)2D3. That both components of this system are coordinately regulated, and that BAEC respond to the 1,25(OH)2D3 hormone by modulating growth kinetics, suggests the existence of a vitamin D autocrine loop in endothelium that may play a role in the development and/or functions of this pathophysiologically significant cell population.

Animals↗
PubMed1989

Immunohistochemical detection of 1,25-dihydroxyvitamin D3 receptors and estrogen receptors by monoclonal antibodies: comparison of four immunoperoxidase methods.

We developed an immunohistochemical method for visualization of vitamin D (VDR) and estrogen receptors (ER) in cryostat sections, using monoclonal antibodies (MAb) to the vitamin D receptor and estrogen receptor, respectively. This method is based on an avidin-biotin labeling technique (LAB). To establish a reliable and sensitive method which can be used easily as a routine diagnostic procedure, we systematically compared four different immunoenzymatic methods with respect to their efficiency in detecting vitamin D and estrogen receptors. Compared to the indirect bridged avidin-biotin (IBRAB), the peroxidase- anti-peroxidase (PAP), and the avidin-biotin complex (ABC) methods, the LAB method produced stronger staining intensities and had higher detection efficiency for both vitamin D and estrogen receptors. In addition, the LAB method had a higher spatial resolution compared to the ABC technique in detection of VDR in normal human skin biopsies. In the case of steroid receptors, i.e., nuclear antigens, immunohistochemistry must deal with a relatively low number of antigenic sites per cell, restricted accessibility of the antigens, and slight differences in antigen concentrations among cells. Under these particular conditions, the chemical properties of the conjugates used in the LAB method may explain why it is superior to the other methods. Consequently, the LAB method is recommended for visualization of ER and VDR.

Animals↗
PubMed1988

[Calcium antagonists in chronic renal failure. Undesirable effects on glomerular hemodynamics?].

Seven patients with glomerular proteinuria and hypertension (six with biopsy confirmation of glomerulonephritis, one with proteinuria after unilateral nephrectomy) were randomly given, for 14 days each, a calcium antagonist and then a conversion enzyme inhibitor, or vice versa, following a 14-day pause of all medication. Fractional albuminuria rose significantly during administration of calcium antagonists (P less than 0.05), while it decreased significantly during administration of converting enzyme inhibitor (P less than 0.05). The explanation for this finding may be that calcium antagonists raise glomerular capillary pressure by dilating the afferent arterioles, while converting enzyme inhibitors predominantly cause dilatation of the efferent arterioles.

Adult↗