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B Greiner

Publications and source records attributed to B Greiner.

16 recordsLinked to original sources
PubMed1998

Cyclosporine A-induced decrease in calbindin-D 28 kDa in rat kidney but not in cerebral cortex and cerebellum.

Recently, we reported that in rat, cyclosporine A (CsA) markedly decreases the levels of calbindin-D (CABP-D) 28 kDa in kidney. CABP-D 28 kDa is a calcium-binding protein which is highly expressed in calcium-transporting tissues such as kidney or brain. In this study, we investigated whether, in addition to the kidney, CsA also has an effect on CABP-D 28 kDa in rat brain. Three groups of male Wistar rats received 15 mg/kg/day or 50 mg/kg/day of CsA orally for 12 days, whereas controls received vehicle solution for the same period. CABP-D 28-kDa protein and CsA were quantified in homogenates of kidney, cerebral cortex and cerebellum, and the localization of CABP-D 28 kDa was assessed in the different tissue sections by immunohistochemistry. In kidney, CABP-D 28 kDa was strongly and dose dependently decreased, and was located in tubular epithelial cells. In brain, CABP-D 28 kDa was not changed and was mainly located in pyramidal cells of the cortex and in cerebellum exclusively in Purkinje cells. High CsA concentrations were measured in kidney, more than 17-fold greater than those found in cortex. In cerebellum, CsA was below the limit of detection. These data suggest that at clinically relevant doses, CsA may not affect CABP-D 28-kDa levels in brain.

Animals↗
PubMed1997

Decreased endotoxin-binding capacity of whole blood in patients with alcoholic liver disease.

BACKGROUND/AIMS: The proinflammatory effects of endotoxemia, which is often observed in alcohol-abusing patients with various degrees of liver disease, may be modulated by changes in the concentration of endotoxin binding factors. Therefore, the plasma endotoxin concentration and the overall endotoxin binding capacity of whole blood were measured in these patients. METHODS: Patients with minor (A1; n=27), more pronounced (A2; n=13), cirrhotic alcoholic liver disease (A3; n=18), and non-alcoholic cirrhosis (NC; n=6), and 15 healthy control persons (HC) were included in the study. Endotoxin plasma levels were determined using a standardized limulus assay. A modified assay was applied to additionally detect tightly bound endotoxin. To measure the endotoxin-binding capacity, aliquots of whole blood were incubated with serial dilutions of endotoxin, supernatants were obtained, and endotoxin retrieval was estimated by addition of limulus lysate, followed by photometric measurement of the maximal reaction velocity (dODmax). Endotoxin binding capacity equals the endotoxin concentration at which dODmax reaches a predefined threshold. RESULTS: All groups of alcohol abusers had significantly elevated endotoxin plasma levels with a considerable portion of 'bound' endotoxin. Conversely, the endotoxin binding capacity was markedly diminished, mainly in patients with more advanced liver disease (A1: 85.8% of the control value [non-significant vs. controls]; A2: 25.4% [p<0.05]; A3: 43.6% [p<0.02], NC: 43.2%). CONCLUSIONS: The endotoxin-binding capacity is diminished in patients with alcoholic and non-alcoholic cirrhosis, as well as in less advanced alcoholic liver disease. Reduced endotoxin binding may contribute to the adverse effects of endotoxemia.

Adult↗
PubMed1995

Effect of blood transfusion on cardiorespiratory abnormalities in preterm infants.

The effects of red blood cell transfusion on the incidences of apnoea, bradycardia, tachycardia and oxygen desaturation over periods of 72 hours before and after transfusion were assessed in 25 infants with a gestational age of < or = 32 weeks (mean (SEM) 29.2 (0.4) weeks, birthweight 1170 (73) g; postnatal age at transfusion 39 (4) days). During transfusion haemoglobin rose from 78 (2) g/l to 117 (2) g/l. Significant decreases were observed in daily frequencies of apnoeas longer than 15 seconds (median from 2.7 to 0.9 events a day), tachycardias of more than 200 beats per minute (from 34 to 25 events per day), bradycardias below 100 beats per minute (from 65 to 12 events per day) and 80 beats per minute (from 8.4 to 3.3 events per day). Oxygen saturation improved in 20 of the infants. Transfusion improves cardiorespiration in preterm infants for several days.

Apnea↗
PubMed1991

Tumour necrosis factor receptor distribution in human lymphoid tissue.

The nature and location of cells responding to tumour necrosis factor-alpha (TNF-alpha) were investigated in situ by immunohistochemistry using monoclonal antibodies (mAb) directed against the p75 and p55 proteins of the TNF receptor. Receptor expression was found in the thymus and secondary lymphoid tissues. In the thymus the p75 receptor was confined to medullary lymphoblasts and dendritic cells, which co-stain with the Tac protein of the interleukin-2 (IL-2) receptor. In lymph nodes and other secondary lymphoid tissues, the p75 receptor was expressed on activated lymphocytes and interdigitating reticulum cells of the T-cell area, whereas the p55 receptor was confined to the germinal centre dendritic reticulum cells (DRC), which is the main site of TNF-alpha production. TNF receptor (TNFR) proteins were up-regulated in reactive hyperplasia together with increased TNF-alpha expression. Surprisingly, no TNFR was detectable on non-lymphoid tissues. The species specificity of these TNFR antibodies was high: whereas the antibodies cross-reacted with epitopes in non-human primates, no immunoreactivity was detected in lower animal species, e.g. dog, rabbit and rodents. The data presented suggest that TNF-alpha, which is produced by germinal centre DRC, might regulate an in vivo immune response through autocrine and paracrine pathways, e.g. through the p55 and p75 receptor proteins, which are expressed at different sites of the lymphoid tissue.

Animals↗
PubMed1991

Distribution of the cyclosporine binding protein cyclophilin in human tissues.

Cyclophilin (CYP) is the major intracellular binding protein for the immunosuppressive drug cyclosporine (CS). CYP distribution was investigated in human tissues by solid-phase immunoassay, Western and Northern blot analysis as well as immunohistochemistry. CYP was found in all tissues examined at concentrations in the range of 1 microgram/mg protein. Furthermore, mRNA specific for CYP was found in every tissue, indicating local production of the protein. Immunohistochemical investigations revealed preferential parenchymal and only little stromal localization. Within certain organs, e.g. kidneys, regional differences of immunoreactive CYP was evident. The presence of CYP was also investigated in several lymphoid and non-lymphoid cell lines and was found at comparable concentrations. Immunogold staining confirmed cytosolic, but revealed also nuclear localization of CYP. The possible role of this abundant CS binding protein is discussed.

Amino Acid Isomerases↗
PubMed1988

Biotinylated recombinant interleukin-2. A tool for research on the interleukin-2 receptor.

Recombinant interleukin-2 was biotinylated using a N-hydroxyl-succinimidyl [3H]biotin ester. The biotinylated lymphokine retained full binding and growth-promoting activities when assayed on the interleukin-2-dependent murine cell line HT-2. In preliminary studies, biotinylated interleukin-2 was used in conjunction with immunogold staining to demonstrate cell surface interleukin-2 receptors using both light and electron microscopy techniques. In addition, with rabbit anti-biotin antibodies, biotin-interleukin-2 was able to precipitate the 55 kDa IL-2 receptor from murine HT-2 cells. Thus, biotin-interleukin-2 represents a useful, non-radioactive tool for studying the structure and function of the interleukin-2 receptor.

Animals↗
PubMed1988

Cyclosporine--relationship of side effects to mode of action.

Although cyclosporine has high specificity for the immune system, immunosuppressive therapy with CsA is often complicated by nephrotoxicity. The main morphologic targets of CsA nephrotoxicity include the tubular epithelial and endothelial cells. These cells were investigated in vitro. CsA caused a dose- and time-dependent inhibition of cell growth, vacuolization and fatty change in adherent cells, detachment, and cell death. Inhibition of 3H-TdR incorporation in cells of both tubular epithelial and endothelial origin occurred between 3 microM and 10 microM. Electron microscopy studies revealed cellular swelling, dilatation of the endoplasmic reticulum, and the presence of lipid droplets and giant mitochondria. The content of the main CsA-binding protein, cyclophilin, in these cell-lines was 5-10 micrograms/mg protein and did not differ in various cell lines, including T cells. Immunohistochemistry using rabbit anticyclophilin antibody revealed diffuse distribution of cyclophilin in the cytosol, nuclear membrane, and nucleolus. Whereas lymphoid cell functions are inhibited at 10-100 nM, CsA had no effect on tubular epithelial and endothelial cells at these concentrations. At concentrations of 3-10 microM, CsA caused growth inhibition and cytotoxicity on cells of lymphoid and nonlymphoid origin. Present evidence shows little, if any, relationship of side-effects to the mode of action of CsA.

Animals↗
PubMed1987

[Computer-assisted implementation of the MMPI test].

In a research programme lasting one year a computer-supported technique for the MMPI-Test has been developed in co-operation of the Clinical-Psychology and the Bio-Medical. Engineering Departments. The use of the microelectronically operated test apparatus has proved extremely economic.

Computers↗
PubMed1984

Two metabolic pathways of tetrahydronorharmane (tetrahydro-beta-carboline) in rats.

Metabolites of (14C) tetrahydronorharmane (THN, tetrahydro-beta-carboline) have been identified by mass spectrometry and nuclear magnetic resonance spectroscopy. Two metabolic pathways are suggested: Hydroxylation of the benzene ring--most probably with an epoxide as intermediate--though no hydroxylated THN could be detected in the urine samples of male and female rats but conjugated compounds as the main metabolites. The intermediary epoxide is supported by the fact, that the hydroxy substituent of THN is positioned on C-6 or C-7 with a ratio of 55:45 in female rats and of 45:55 in male rats. Dehydrogenation yielding norharmane. This substance possibly gives rise to another metabolite--1,2-dihydro-beta-carboline-1-one. The pharmacological and toxicological implications of these findings are discussed.

Animals↗
PubMed1983

Pharmacokinetics of tetrahydronorharmane (tetrahydro-beta-carboline) in rats.

The distribution, metabolism and elimination into the urine of (14C)-tetrahydronorharmane (THN) as well as of (14C)-6-hydroxy-tetrahydronorharmane (6-OH-THN) are investigated in female and male rats. Following intravenous injection of (14C)-THN radioactivity was detected in all organs examined, namely blood, brain, lung, adrenal gland, small intestine, fat tissue, kidney and liver. In the brain the elimination half life of THN was calculated to be 1.8 h, the elimination half life of the radioactivity in the blood 6.24 h, and the accumulation half life in the urine 9.24 h. The elimination of 6-OH-THN into the urine is faster than that of THN. At least four metabolites of (14C)-THN were found in the urine of female rats. Two different metabolic pathways are discussed, firstly, hydroxylation followed by conjugation with glucuronic and sulfuric acids and secondly, dehydrogenation, followed by oxygenation. In female rats only traces of the conjugated metabolites are hydrolysed by arylsulfatase, whereas in male rats approximately 2/5 are cleaved by this enzyme. Pretreatment of male rats with 3-methylcholanthrene induced conjugation, whereas phenobarbital had no obvious effect on the pattern of metabolites. SKF 525 A and CFT 1201 both prevented almost completely the formation of conjugates from THN.

Alkaloids↗
PubMed1982

Is there a correlation between the concentration of beta-carbolines and their pharmacodynamic effects?

Two sensitive and specific methods are presented for the determination of 6-OH-tetrahydronorharmane (6-OH-THN, 6-OH-THBC) and harmane (1-Me-BC). The concentration of 6-OH-THN in blood platelets from men was found 5.19 +/- 0.57 ng (mean +/- SEM) per 10(9) platelets, of acute schizophrenic patients 2.66 +/- 0.38 ng per 10(9) platelets, p less than 0.02, and in rats 6 - 13 ng x 10(9) platelets. The concentration of harmane in the urine of rats was measured 9.72 +/- 1.56 ng per 16 h. A load with ethanol caused an increased excretion of the beta-carboline in some rats. In pharmacological experiments substantial evidence was detected for a correlation between the (3H)-flunitrazepam displacing potency and the conflict-augmenting effects of beta-carbolines. Furthermore, a good correlation was found between the results of binding experiments and the antagonism of the beta-carbolines with respect to the activating effect of low doses of diazepam. No such correlation exists for the sedative effect.

Alkaloids↗
PubMed1982

Urinary metabolites of tetrahydronorharmane in the rat.

The metabolism of THN in the rat was studied in vivo by use of 14C-radiolabelled compound. Structures of major urinary metabolites were determined by exact spectral data. Their concentrations were measured by liquid scintillation counting. It was found that THN is submitted to endogenous transformation, and that the excreted derivatives form three groups of similar concentration: unchanged substance, hydroxylated/conjugated compounds, and aromatic metabolites. Structures and proposed pathways are summed up in the diagram on the following page.

Animals↗
PubMedDate not supplied

Tea time.

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Aged↗
PubMedDate not supplied

[Value of the plain roentgen image and arthrography in diagnosis of loosening of cemented hip endoprostheses].

Radiographic signs of suspected prosthetic hip component loosening were evaluated by comparing them with the intraoperative findings. In 59 surgical procedures for suspected loosening of cemented total hip prostheses preoperative radiographic signs of loosening in plain radiographs and radiographic arthrograms were compared with the intraoperative findings. Radiolucent lines between the interfaces prosthesis/cement and cement/bone in defined zones (Salvati et al. 1976, Gruen et al. 1979) were evaluated. For the acetabular component relevant radiolucent lines were observed only between the interface cement/bone. A radiolucent line > 2 mm in zone 1, > 1 mm in zone 2a, a fracture or a retroversion were shown to be reliable signs for loosening with a specificity of 92%, a sensitivity of 61% and a predictive value of 97% (p < 0.01). For the femoral component a radiolucent line at the cement/bone interface of > 1 mm in any of the single zones 2, 3, 6 or 7 and radiolucent lines of > 0 mm in the combined zones 1 + 2 + 6 + 7 proved to be reliable signs of loosening. At the cement/prosthesis interface of the femoral component a radiolucent line of any width in zone 6 and radiolucent lines in the combined zone 1 + 2 or 1 + 7 proved to be reliable signs for loosening as well as major defects within the cement. The above mentioned signs of femoral component loosening display a specificity of 79%, a sensitivity of 86% and a predictive value of 81% (p < 0.001). Arthrography may be useful as an additional diagnostic means for the acetabular component (7 out of 18 false negative results in the radiograms were true positive in the arthrography. Penetration of the contrast material through all 4 zones yields a specificity of 83%, a sensitivity of 48% and a predictive value of 90% with p > 0.05), whereas for the evaluation of the femoral component loosening the gain of information is marginal compared with plain radiographs (specificity 80%, sensitivity 69% and predictive value 78% with p < 0.01). Hip component loosening can be identified with the above mentioned signs even if there are no previous radiographs available.

Arthrography↗