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Biomedical subjects

E W Rauterberg

Publications and source records attributed to E W Rauterberg.

At least 19 recordsLinked to original sources

[Neonatal screening for congenital hypothyreoidism in Germany. The development of concerned children in retrospect analysis using the federal state "Hessen"].

BACKGROUND: Since widespread screenings for hypothyreosis were started in 1981 in Germany, the numbers of mental and physical handicaps due to hypothyroidism are reduced markedly. The aim of this study is to evaluate the actual efficiency of the newborn screenings in Germany using in the federal state "Hessen". METHODS/SUBJECTS: All children born between 1988 and 1992 with suspicions laboratory results in the screening examination were contacted personally and statements concerning the screening itself and the physical and mental development were gathered from their parents, doctors and teachers. RESULTS: 99.1% of all hessian newborns born between 1988 and 1992 were included into the screening for hypothyreosis. The incidence of congenital hypothyreosis in general was 1:3 313. An etiological classification was possible in 77% of the patients which is divided as follows: 40% athyreosis, 24% hypoplasia of the thyroid, 8% dyshormonogenesis, 5% ektopia of the thyroid. In 67% of the cases hormone substitution was initiated during the first 14 days of life. In 23.9% it was started in the third week, in 6.8% in the fourth week and only in 2.3% of the patients treatment was started later on. The physical development of the children with congenital hypothyreosis can be regarded as widely normal. The school achievement was moderately retarded even when treatment was started in the early neonatal period. CONCLUSIONS: The screening for hypothyreosis is well established in Hessen concerning tracking, organisation and analysis. There are short comings concerning the follow ups of children with suspicions findings, which shall be overcome by creating a new position. The long-term-follow-up according to the guidelines of the "Arbeitsgemeinschaft Pädiatrische Endokrinologie" is of central interest. Furthermore compliance is improved by regular personal counselling with the parents.

Adolescent↗

Expression of fetal cytokeratins in epidermal cells and colloid bodies in lichen planus.

Clusters of immunoglobulin (Ig)-coated colloid bodies (CBs) in the dermo-epidermal zone are a typical immunohistochemical feature in lichen planus (LP)-lesions. They are considered to represent dyskeratotic basal keratinocytes, yet their composition has not been completely elucidated. In the present study, skin biopsies of 10 LP-lesions, 3 other dermatoses, and 10 biopsies of normal skin were studied immunohistochemically using monoclonal antibodies (MAbs) against fetal and differentiated epidermal antigens. CBs were identified by FITC-anti-Ig. Binding of MAb was visualized by double staining technique. Cytokeratin (CK) 10/11, a marker of epidermal differentiation, was consistently detected in suprabasal keratinocytes and also in up to 95% of Ig-positive CBs in LP. CK10/11 was additionally detected in basal keratinocytes in 9 LP-lesions, but not in normal skin. The basal cell-specific MAb BL7 stained basal layer keratinocytes in all biopsies. In contrast to normal skin, in LP scattered suprabasal keratinocytes and CBs were also positive for BL7 in 10 and 7 cases, respectively. While fetal cytokeratins (CK13 and CK8/18) were completely absent in control skin specimens, both cytokeratins were detected in various numbers of keratinocytes and CBs in all LP-lesions. Our results support the hypothesis of an epidermal origin of CBs. The cytokeratin profile seems to be severely disturbed in LP. This includes both accelerated differentiation by the expression of suprabasal CK10/11 in basal keratinocytes and dedifferentiation by the expression of fetal epidermal antigens (CK13 and CK8/18). It is tempting to speculate that the observed alterations may trigger T-cell activation and inflammatory onset in LP.

Adolescent↗

Effects of systemic complement activation on renal circulation of rats.

In a variety of immunopathological diseases activation of the complement cascade occurs either systemically or localized in the kidney. To elucidate the functional impact of complement activation upon the renal microcirculation, we administered cobra venom factor of Naja naja kaouthia (CVF) i.v. into thiobarbital anaesthetized female rats. CVF is a potent activator of the alternative pathway of complement by forming the C3-convertase CVF, Bb which cannot be downregulated by the natural inhibitor factors H and I and thereby leads to generation of the anaphylatoxins C3a and C5a and formation of the membrane attack complex (MAC). We utilized creatinine clearance and flowmeter measurements in the normal kidney and intravital microscopy of the split hydronephrotic rat kidney model to observe the microvascular changes. Bolus injection of CVF (100 U kg-1) resulted in an immediate reduction of RBF (-68% after 10 min), which remained decreased during the entire experiment (90 min). Systemic blood pressure was significantly reduced only in the early period (-23% of control: 126 mmHg after 10 min). After an initial anuric phase of 30 min duration, the glomerular filtration rate was significantly diminished by 47%. White cell count was decreased by about 50% after the experiments. Application of the competitive thromboxane A2-antagonist, BM 13505, reversed all renal and systemic CVF-effects. Continuous infusion of the competitive leukotriene D4-antagonist, ICI 198615, attenuated the late renal CVF-effects (i.e. 30 min after injection of CVF). Depletion of polymorphonuclear cells (PMN) attenuated the CVF-effects similar to BM 13505. Intravenous administration of CVF in the hydronephrotic kidney model resulted in a massive constriction of the interlobar and arcuate artery, with a fall in glomerular blood flow comparable to the reduction of RBF in the normal kidney. Diameters of the afferent arterioles--most sensitive to many vasoconstricting agents--were not significantly altered. Our results suggest that injection of CVF and the liberation of high amounts of the anaphylatoxins, C3a and C5a, induces the release of TXA2, which contributes to the early renal effects and the formation of cysteinyl-leukotrienes which play an important role in the late phase of systemic complement activation. Utilizing the split hydronephrotic kidney model we demonstrated the predominant action of complement activation on the large preglomerular vessels for the first time. PMN are seemingly involved in the liberation of secondary mediators which appear to reduce renal blood flow and glomerular filtration.

Animals↗

Bioincompatibility--perspectives in 1993.

Bioincompatibility reactions related to the non-physiology of the procedure have plagued dialysis from its early days. Although the problem is certainly multifactorial, the present overview selectively focuses on some aspects of activation of late complement (C) components, the importance of which may have been underappreciated in the past. Dialysis patients are poised for intense C activation because of cumulation of the low molecular weight factor D, an intrinsically active serine esterase which is not inhibited by any known endogenous inhibitor and catalyzes an early step in the alternative pathway. C activation reflects the net balance between activation and inhibition, the latter particularly via factor H binding. Dialyzer membrane characteristics that are related to factor H binding and regulation of initial activation steps include not only membrane surface chemistry but also its microdomain structure. Kinetic studies of the generation of the terminal complement complex (TCC) suggest ongoing generation throughout the duration of a dialysis session (in contrast to the transient release of C-derived anaphylatoxins). Potential consequences of TCC generation include amplification of the non-C-dependent cell activation signals through L-fucose-dependent steps. Efforts to reduce TCC generation by membrane engineering, for example, end group derivatization and optimization of microdomain structure, open perspectives for the development of more biocompatible membranes.

Biocompatible Materials↗

Effects of rC5a on the circulation of normal and split hydronephrotic rat kidneys.

Systemic release of complement-derived anaphylatoxin C5a is suggested to be involved in the pathogenesis of renal failure during endotoxic or severe traumatic shock. In the present study we analyzed renal hemodynamic effects of recombinant human complement 5a (rC5a) and examined whether these effects are mediated by the secondary release of other inflammatory mediators. Intravenous infusion of rC5a (0.5 micrograms/min) in thiobarbital-anesthetized rats decreased renal blood flow (RBF) by 20 and 34% after 20 and 60 min, respectively. Glomerular filtration rate (GFR) was reduced by 45%, whereas filtration fraction and blood pressure were not significantly changed by rC5a. Hematocrit (Hct) increased by 11%, whereas white blood cell count decreased by 40%. Renal rC5a effects were completely inhibited by the competitive leukotriene D4/E4 antagonist ICI-198615, whereas the competitive thromboxane A2 (TxA2) antagonist daltroban only partly reversed rC5a effects on RBF and GFR. The competitive platelet-activating factor (PAF) antagonist L-695989 did not influence renal or systemic rC5a effects. These results point to an rC5a-mediated synthesis and release of cysteinyl leukotrienes and TxA2, whereas PAF does not seem to be released after intravenous rC5a in rats. To determine the cellular source of cysteinyl-leukotriene synthesis, rats were depleted of polymorphonuclear cells (PMN) by intraperitoneal injection of anti-rat PMN antibodies, which abrogated renal and systemic hemodynamic rC5a effects, suggesting that PMN participate in the synthesis and release of cysteinyl leukotrienes. The exact localization of renovascular rC5a effects was performed on the model of the split hydronephrotic rat kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Complement deposits in epidermal cells after ultraviolet B exposure.

Ultraviolet B (UVB) radiation is known to induce formation of sunburn cells (SBC) in the epidermis. Since it was unknown whether this process might be accompanied by complement (C) activation, we analyzed C-deposition in skin biopsies taken before and 24 h and 48 h after UVB exposure (fourfold minimal erythema dose or fourfold minimal phototoxic dose) from 14 patients (5 receiving potentially photosensitizing drugs and 9 without such medication) by immunohistology. Local C-activation was visualized by direct or indirect immunofluorescence staining with polyclonal antibodies against C3b, C3d, C5, C9 and monoclonal antibodies to C3b, C3d, C9 and neoantigens on the terminal complement complex (TCC). Neutrophils were identified immunohistologically by antibodies to polymorphonuclear elastase. All but one specimen taken before UVB irradiation were completely negative; biopsies obtained 24 h after UVB revealed complement C3b- and/or C3d-deposits within scattered cells of the epidermis, with wide individual variations in the number of C3-positive cells. C3b and TCC were found predominantly in the cytoplasma; C3d deposits were more often accentuated at the cell surface of C-positive cells. A significantly higher number of keratinocytes was C3d-positive 48 h after UVB exposure than in specimens taken 24 h after UVB. Such a reactivity pattern might indicate a rapid decay of intracellular C3b to C3d. Patients medicated with potentially photosensitizing drugs developed significantly higher numbers of strongly C3-positive cells than those without such medication. Infiltration with elastase-positive cells, presumably representing neutrophils, was observed in the upper third of the dermis and the epidermis in all but one biopsy (n = 9) after UVB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗