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E Schmitz

Publications and source records attributed to E Schmitz.

At least 37 records · Page 2Linked to original sources
PubMed1991

Functional characterization of estrogen and glucocorticoid responsive elements in the rat oxytocin gene.

Expression of the gene encoding the oxytocin precursor occurs in the hypothalamus and, to a lesser extent, in a number of peripheral organs, the tissue-specific regulatory mechanisms of which are largely unknown. By DNA sequence analysis several elements upstream of the transcriptional start point of the rat oxytocin gene were identified matching the consensus sequence of enhancers inducible by estrogen or glucocorticoids, respectively. Their general transactivating capacities were investigated using heterologous gene constructs and revealed that the rat oxytocin gene harbours two functional estrogen responsive elements near the transcription initiation site, one of which is conserved in the respective human gene. In addition, one enhancer conferring glucocorticoid responsiveness to a reporter gene is located at nucleotide residues -2449 to -2464. These data might indicate a steroid hormone-mediated influence on oxytocin gene expression in the central nervous system and/or the periphery.

Animals↗
PubMed1991

Kindling does not induce persistent changes in fluorographic labeling patterns of benzodiazepine binding proteins in various rat brain regions.

The GABAA receptor has been implicated in the mechanisms underlying the phenomenon of kindling. Photoaffinity labeling with 3H-flunitrazepam followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allows the fluorographic visualization of GABAA receptor proteins with benzodiazepine binding sites which presumably correspond to different alpha-subtypes. This method offers an opportunity to investigate whether up- or down-regulation of single benzodiazepine binding proteins occurs. In the present study, labeling patterns of benzodiazepine binding proteins were determined in 12 brains regions of amygdala-kindled rats (2 weeks after the last fully kindled seizure) and sham-operated controls. For most brain regions, labeling patterns were separately determined for the ipsi- and contralateral side. A comparison of the labeling patterns thus obtained revealed no persistent changes between kindled animals and controls in any of the brain regions, including amygdala, substantia nigra and hippocampus. Thus, we conclude that kindling does not induce fluorographically detectable changes in the expression patterns of the benzodiazepine binding proteins. The results confirm the existence of regional heterogeneity of benzodiazepine binding proteins and extend the findings to brain regions which had previously not been investigated.

Affinity Labels↗
PubMed1991

[The implantation of self-expanding metal prostheses (stents) into the bronchial system in central neoplasms].

This paper reports the use of an endobronchial metallic prosthesis (wall stent) for palliative management of 6 patients with central neoplasms and life-threatening airway obstruction. In five of six patients implantation of the stent resulted in improvement of their dyspnoea. However, functional data showed only a slight amelioration. In case of endobronchial growth, tumour may protrude easily through the meshwork of the stent. Therefore, use of the stent in these patients only seems appropriate if combination with other forms of therapy (radiation, laser) is possible. The easy feasibility of stent implantation and the lack of severe side effects and migration indicate that the stent may be an effective means in patients suffering from peribronchial tumour compression.

Airway Obstruction↗
PubMed1991

Rat vasopressin and oxytocin genes are linked by a long interspersed repeated DNA element (LINE): sequence and transcriptional analysis of LINE.

Sequence analysis of the rat vasopressin and oxytocin gene family reveals that the two genes are linked by a long interspersed repeated DNA element (LINE) giving rise to seven long open reading frames encoding hypothetical proteins of 99 to 556 amino acid residues. Furthermore, although both DNA strands of LINEs serve as templates for transcription, transcripts initiated at the 3' end are more abundant than those started from the 5' end. The LINEs are transcribed preferentially in brain tissues as analyzed by Northern blot, in situ hybridization, and RNase protection experiments. The data show that most LINEs are transcribed at their entire length and that a major fraction of respective RNAs does not enter the cytoplasm but remains in the cell nucleus.

Amino Acid Sequence↗
PubMed1990

[Chlamydia-induced arthritis: diagnosis--follow-up--therapy].

Chlamydia-induced arthritis (CIA) is an inflammatory reactive arthritis caused by extraarticular infection with Chlamydia trachomatis. CIA presents as peripheral arthritis or spondylarthropathy. Extraarticular manifestations are present in most but not all cases, Reiter's syndrome occurs only in a minority of patients. Detection of Chlamydia trachomatis in genitourinary smears and demonstration of serum-antibodies against chlamydial antigens lead to diagnosis. Analysis of synovial fluid reveals nonpurulent inflammatory synovitis and, in some cases, chlamydial antigen has been demonstrated in synovial specimens. The therapy of CIA combines physical medicine, NSAID and shortterm antibiotic treatment of the genitourinary infection. Whether longterm antibiotic therapy or-in chronic cases--DMARDs are successful, needs further investigation.

Arthritis, Infectious↗
PubMed1989

Photolabeled tryptic degradation products of benzodiazepine-binding proteins are glycopeptides. Implications for localization of cleavage sites.

Crude synaptic membranes of avian and mammalian brain tissue were photolabeled with the benzodiazepine-receptor ligand [3H]flunitrazepam and subsequently treated extensively with trypsin followed by incubation with endoglycosidase F. SDS-polyacrylamide gel electrophoresis and fluorography revealed that the final tryptic degradation product of 25 kDa in both pigeon and calf brain is deglycosylated in two steps. These results were confirmed by immunoblots of similarly pretreated membranes of pig brain using the alpha-subunit-specific monoclonal antibody bd-24. Benzodiazepine-receptor binding and its enhancement by GABA are largely retained after trypsinization. Based on the proposed transmembrane topology for the alpha-subunits of the GABA/benzodiazepine receptor, we suggest that the large N-terminal domain of benzodiazepine-binding proteins is protected against tryptic cleavage.

Animals↗
PubMed1989

New echocardiographic and angiographic methods for right atrial volume determination: in vitro validation and in vivo results.

Until now, right atrial (RA) volume calculation by means of two-dimensional echocardiography (2-DE) has only been attempted in a single plane: the apical four-chamber view. Our study reports a new method for RA volume calculation using two intersecting 2-DE views. For this purpose, silicone rubber casts of 19 human necropsy hearts were obtained and thin-walled natural rubber moulds of the RA casts were prepared. Totally filled with and immersed in water, the moulds could be visualized in the apical four-chamber view and an additional 2-DE plane, the latter corresponding to the subcostal view in vivo. In this view the vertical extension of RA could be estimated. Areas and lengths of RA were determined in the respective planes, and RA volume was calculated by applying the formula, area x length, to two intersecting planes. Finally, volume of the silicone casts was determined angiocardiographically (Angio) using a biplane method (30 degrees RAO, 40 degrees LAO-40 degrees hepatoclavicular). The true RA volume was 106 +/- 23 ml (mean +/- 1 SD) as determined by water displacement. Using Angio an excellent correlation was found: the calculated volume amounted to 106 +/- 23 ml; the difference was 5.5 +/- 4.8 ml (n.s.); Angio vol = 0.93 true vol + 7.77; r = 0.95; SEE = 7.4 ml. Volume determination from the apical four-chamber view of 2-DE using a monoplane disk method resulted in a mean volume of 62 +/- 17 ml. The mean difference to the true RA volume was 44 +/- 16 ml (p less than 0.001). When volume calculations were made using the biplane method, a value of 105 +/- 22 ml resulted. The mean difference to true volumes was 7.4 +/- 4.8 ml: y = 0.84x + 15.88; r = 0.91; SEE = 9.4 ml. In an in vivo study endsystolic RA volumes were calculated in a normal adult population (n = 40) from the same intersecting planes as in vitro. A normal value of 38 +/- 6 ml/m2 was found. In vivo validation using Angio showed a slightly higher normal value of 43 = 7 ml/m2. Thus, 2-DE is highly accurate in determining RA volume. In the in vitro as well as in the in vivo study the results of monoplane calculations are clearly inferior to a method which also takes account of the vertical extension of RA.

Adult↗
PubMed1989

Postmortem degradation alters fluorographic labeling patterns and affinities of benzodiazepine binding proteins.

To investigate the effect of endogenous proteolysis on the molecular weights of the benzodiazepine binding proteins, brains of trout, chicken, and rat were removed immediately after death and stored at room temperature for various periods of time before they were frozen. Photoaffinity labeling of membranes with [3H]flunitrazepam, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography, revealed proteolytic fragments of 47K in trout, chicken, and rat. The proteolysis set in rapidly after death. Seemingly in parallel with the degradation observed fluorographically, the affinity for [3H]flunitrazepam increased without systematic changes in receptor density. The degradation pattern was not identical to that of the photolabeled trypsinized benzodiazepine binding proteins. The endogenous proteolytic fragments were deglycosylated in two steps. In conclusion, proteolytic effects must be taken into account when interpreting labeling patterns and binding parameters.

Animals↗
PubMed1988

A comparative phylogenetic study of the distribution of cerebellar GABAA/benzodiazepine receptors using radioligands and monoclonal antibodies.

In mammalian cerebella the distribution of high affinity GABAA and benzodiazepine binding sites does not parallel each other. Differences in the molecular structure of the receptor complex or conformational changes have been proposed to explain the lack of a co-localization of these binding sites. Using radio- and immunohistochemistry we were able to obtain similar results for cerebella of non-mammalian species, indicating that the respective distribution of the binding sites is well conserved throughout vertebrate evolution. The gamma-aminobutyric acid agonist [3H]muscimol and the beta-subunit specific antibody bd-17 strongly labeled the granular layer. The radioligands for the benzodiazepine binding site [3H]flunitrazepam and [3H]Ro 15-1788 revealed species variation in the ratio of benzodiazepine receptor density in the granular and molecular layers. In human and pig cerebellum, the localization of antigenic sites recognized by the alpha-subunit specific antibody bd-24 deviates from the distribution of the benzodiazepine binding sites.

Animals↗
PubMed1988

Persistence of species variation and regional heterogeneity of the apparent molecular masses of benzodiazepine-binding proteins after deglycosylation.

Brain membrane preparations of different vertebrates were photoaffinity labeled with [3H]flunitrazepam and subsequently deglycosylated with endoglycosidase F and peptide N-glycopeptidase. SDS-polyacrylamide gel electrophoresis followed by fluorography revealed that each benzodiazepine-binding protein is deglycosylated in two steps, indicating that each protein has two glycosylation sites. Species variation of the apparent molecular masses of the benzodiazepine-binding proteins and regional heterogeneity in avians persist after deglycosylation. These results indicate that the alpha-subunit(s) of the GABA/benzodiazepine receptor has undergone electrophoretically detectable changes in its amino acid composition during vertebrate evolution. The existence of at least two different alpha-subunits in avians is further substantiated.

Animals↗
PubMed1988

The shark GABA-benzodiazepine receptor: further evidence for a not so late phylogenetic appearance of the benzodiazepine receptor.

Whilst the brain-specific benzodiazepine receptor has been assumed to show a late evolutionary appearance, we present evidence for the presence of a central benzodiazepine binding site in sharks, which shows a high affinity for [3H]Ro 15-1788. However, the receptor density and the affinities of several benzodiazepine receptor ligands are lower than in mammals, thus presumably explaining why the benzodiazepine binding sites had previously escaped detection in elasmobranchs. Additionally, radio- and immunohistochemistry were performed to localize the radioligand binding sites and the antigenic sites of the shark gamma-aminobutyric acid (GABA)-benzodiazepine receptor. In cerebellum, the granular layer reveals a high density of [3H]muscimol binding sites. The immunoreaction obtained with the beta-subunit-specific monoclonal antibody bd-17 seemingly parallels the distribution of high-affinity GABA binding sites. In contrast, [3H]Ro 15-1788 binding sites are evenly distributed in the molecular and granular layers, thus the results are similar to those previously described for rat cerebellum. Apparently, the respective distributions in this brain region are well conserved throughout vertebrate evolution.

Animals↗
PubMed1988

Limited tryptic proteolysis of the benzodiazepine binding proteins in different species reveals structural homologies.

Peptide mapping can be used to elucidate further the structural similarities of the benzodiazepine binding proteins in different vertebrate species. Crude synaptic membrane preparations were photoaffinity-labeled with [3H]flunitrazepam and subsequently degraded with various concentrations of trypsin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by fluorography allowed a comparison of the molecular weights of photolabeled peptides in different species. Tryptic degradation led to a common peptide of 40K in all species investigated, a finding indicating that the benzodiazepine binding proteins are structurally homologous in higher bony fishes and tetrapods.

Affinity Labels↗
PubMed1987

[Clinical studies of peripheral venous parenteral nutrition. Effect of a 3.5% amino acid solution on postoperative metabolism with special reference to amino acid homeostasis].

We studied 20 patients following vaginal hysterectomy until the third postoperative day. 10 patients (group I) in this randomized controlled study were infused only with water and electrolytes in a volume of 40 ml/kg BW. 10 patients (group II) received a 3.5% amino-acid solution with 6% carbohydrates in the same volume. In group II the nitrogen balance was significantly better than in group I. The nitrogen retention of 81% was judged as rather good. We have shown that there were no changes in the concentration of free plasma amino acids in group II, opposite we found significant changes especially in the branched-chain amino acids and alanine in group I. The normalization of metabolized amino acids and the normal concentration of the nonesterified fatty acids in group II demonstrated that the utilization of added amino acids took place not only in peripheral but also in visceral tissues. Our study indicates that the proven amino-acid solution can be recommended as peripheral-venous parenteral nutrition in the postoperative phase.

Amino Acids↗
PubMed1985

[Detection of macrophage activity in the blood and synovia of chronic polyarthritis patients using an activated oxygen microassay].

A microassay was developed for the estimation of macrophage (M phi)-activation by released activated oxygen. From peripheral blood or synovia M phi are isolated. O-2 which is released by activated M phi is photometrically detected by cytochrome c reduction. Differences in O-2-production do not exist between monocytes of rheumatoid arthritis patients and controls. In contrast synovial M phi from rheumatoid arthritis patients show increased levels of O-2-production.

Arthritis, Rheumatoid↗