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G Poschmann

Publications and source records attributed to G Poschmann.

7 recordsLinked to original sources
PubMed2003

Expression of MUPP1 protein in mouse brain.

Localizing cell surface receptors to specific subcellular sites can be crucial for proper functioning. PDZ proteins apparently play central roles in such protein localizations. 5-HT(2C) receptors have previously been shown to interact with MUPP1, a multi PDZ domain protein, in heterologous systems and in rat choroid plexus. We now report the generation and characterization of two independent MUPP1 antisera, which recognise distinct areas of the mouse brain in agreement with previous in-situ hybridization studies. Our results indicate that MUPP1 immunoreactivity co-localizes with 5-HT(2A) or 5-HT(2C) receptor expression in all regions of the mouse brain, including the choroid plexus where 5-HT(2C) receptors are highly enriched.

Animals↗
PubMed1995

Cardiac output in single-lead VDD pacing versus rate-matched VVIR pacing.

The importance of atrioventricular synchronous pacing compared with single-chamber rate-responsive pacing is still under discussion, especially for low-intensity workload representing daily life activities. We evaluated hemodynamics in single-lead VDD pacing versus VVIR pacing in 11 patients (8 men and 3 women, aged 58.6 +/- 13.8 years) with normal left ventricular function and a previously implanted single-lead VDDR pacemaker. A low-intensity steady-state treadmill test at 1 to 2.5 mph with a gradient of 2% to 4% was performed. Cardiac output was determined using a standard carbon dioxide rebreathing technique. Initially, the VDD mode was programmed, and after 5 minutes of exercise, cardiac output was measured in steady-state conditions. The pacemaker was then reprogrammed to the VVI mode at a rate 5 to 10 beats above the maximal atrial tracking rate to simulate rate-matched VVIR pacing (VVIRm). After 5 additional minutes of steady-state exercise, cardiac output was measured again. The maximal atrial rate in the VDD mode was 119 +/- 19 beats/min versus a programmed rate of 129 +/- 18 beats/min in the VVIRm mode. VDD pacing resulted in a significantly higher cardiac output than VVIRm pacing (10.6 +/- 1.9 vs 9.2 +/- 1.4 L/min; p < 0.002), with a mean difference of 1.6 +/- 1.2 L/min between the 2 modes. In the VDD mode, stroke volume (90.7 +/- 20.1 vs 71.6 +/- 13.0 ml; p < 0.001) and maximal oxygen uptake (1,183 +/- 264 vs 1,076 +/- 289 ml/min, p < 0.01) were also higher than in VVIRm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Atrial sensing by a new VDD pacemaker].

VDD stimulation is an alternative to DDD pacing due to the possibility of p-wave synchronous ventricular pacing without the need of an atrial lead. Mainly, the reliability of the system depends on the atrial sensing. In 22 patients the intraoperative atrial amplitude and, postoperatively, the atrial sensing threshold were measured. Furthermore, the stability of the atrial sensing threshold during follow-up was proven. The mean atrial amplitude was intraoperative by 2.4 +/- 1.2 (1.0-6.8) mV. The measurement of the atrial sensing threshold in the first 5 postoperative days showed a mean value of 1.02 +/- 0.49 (0.3-1.6) mV. The measurements of the mean atrial sensing threshold after 30, 90, and 180 days showed no statistical differences. Intraindividual variance was shown in 17/20 patients (0.55 +/- 0,42; 0.15-1.05 mV). Seventeen of the 22 patients were programmed with an atrial sensing threshold of 0.3 mV. In five patients the atrial sensing threshold was programmed at less than 0.3 mV in order to reach a twofold atrial sensitivity. Despite a programmed atrial sensitivity of 0.1 mV and isometric conditions no atrial oversensing occurred. The postoperative atrial sensing thresholds of the VDD system investigated were significantly lower than the intraoperatively measured atrial amplitudes. The mean atrial sensing threshold did not change during the follow-up period. The variation which did occur was within individual variation at different return visits.

Aged↗
PubMed1992

SDZ PSC 833, a non-immunosuppressive cyclosporine: its potency in overcoming P-glycoprotein-mediated multidrug resistance of murine leukemia.

Cyclosporin A (CsA, Sandimmune) is known to reverse P-glycoprotein (P-gp170)-mediated multidrug resistance as efficiently as other prototype compounds of resistance modifiers. The immunosuppressive activity and nephrotoxicity of CsA, however, may limit its clinical use. PSC-833, a new cyclosporine, exerts a similar resistance-modifying activity but lacks toxicity or immunosuppressive activity. We have tested its potency in vitro and in vivo on the L1210 leukemia cell line transfected with a full-length cDNA copy of the human mdr I gene, which showed a stable 30-fold resistance towards adriamycin as compared to the parental cell line. In vitro growth of the transfected cell was unchanged. In vivo growth was less aggressive; the survival time of inoculated mice was prolonged. In vitro, PSC-833 was at least as potent as CsA or verapamil in reversing multidrug resistance. In vivo, the drug-resistant L1210 leukemia was completely unresponsive to i.v. monotherapy with adriamycin at its maximum tolerated dose (MTD). PSC-833 enhanced the activity and toxicity of adriamycin. The MTD of adriamycin was about 3 times lower than when given alone. On this basis, the MTD of i.v. adriamycin in combination with oral PSC-833 successfully overcame refractoriness to treatment. Survival times of the mice were considerably prolonged and even some cures of leukemic mice occurred.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1983

Phosphorylation of myelin basic proteins: an age-dependent process affected by divalent cations and Co-Dergocrine (dihydroergotoxine).

Separation of rat cortical or hippocampal myelin preparations after in vitro phosphorylation on sodium dodecyl sulfate slab gel electrophoresis revealed several phosphorylated proteins with molecular weights between 12,000 and 25,000. The major phosphate acceptors seemed to be two basic proteins. This in vitro phosphorylation of myelin uses endogenous phosphokinase activity and was not influenced by biologically relevant concentrations of cyclic AMP or cyclic GMP. However, phosphorylation was stimulated by addition of Ca2+ and completely inhibited by omission of Mg2+ from the incubation medium. In vitro phosphorylation of CNS myelin proved to be age dependent: increased phosphate incorporation into CNS myelin basic proteins was observed up to the age of about 12 weeks. A steady decline in phosphate incorporation occurred thereafter leaving little in vitro phosphorylating capacity at 80 weeks of age or more. Old animals (80 weeks), when treated with Co-Dergocrine, showed improved in vitro phosphorylating capacity of myelin preparations approaching that found in young control animals.

Aging↗
PubMed1978

Effects of the epipodophyllotoxin derivative VM 26 in mitosis and in interphase.

The epipodophyllotoxin derivative VM 26 inhibits entry of mouse mastocytoma cells into mitosis in cell cultures at drug concentrations of 0.01--1 microgram/ml, the cells being arrested in G2 phase of the cell cycle. At higher concentrations, the compound exhibits spindle poison activity which manifests itself in a shortlasting rise in the number of cells arrested in metaphase of mitosis. These cells then disintegrate after a short period of time.

Animals↗