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G Lüönd

Publications and source records attributed to G Lüönd.

4 recordsLinked to original sources
PubMed1995

The competitive NMDA antagonist CGP 40116 permanently reduces brain damage after middle cerebral artery occlusion in rats.

In this study we evaluated the effect of the competitive N-methyl-D-aspartate (NMDA) antagonist D-(E)-4-(3-phosphonoprop-2-enyl)piperazine-2-carboxylic acid (CGP 40116) on both early (2 days) and late (28 days) ischemic brain damage in a rodent model of focal cerebral ischemia by means of magnetic resonance imaging (MRI) and conventional histology. Immediately after occlusion of the left middle cerebral artery (MCA), rats received either CGP 40116 (20 mg/kg i.p.) or isotonic saline. Two MRI scans were performed in each animal 2 and 28 days after MCA occlusion. After the second scan, rats were perfusion fixed for histological evaluation. The volume of lesioned brain tissue as determined by MRI or histology was calculated from the damaged area in single sections and the distance between them. CGP 40116 reduced acute infarct volume as measured by MRI 2 days after MCA occlusion by 44% (p < 0.05, analysis of variance). After 28 days the lesion detected by MRI was still significantly smaller in the drug-treated animals. This finding was confirmed by the histological analysis showing a 64% reduction in the volume of brain atrophy in the CGP 40116 group (p < 0.05, analysis of variance). There was a good correlation between the MRI data and the results of the histological evaluation (r = 0.9). Our results indicate that (a) the competitive NMDA antagonist CGP 40116 permanently protects brain tissue from the consequences of cerebral ischemia in a rat model for human stroke and (b) early and late pathological changes can be accurately measured by MRI.

2-Amino-5-phosphonovalerate↗
PubMed1987

Stone formation in human kidney.

Microscopic crystals were found by SEM analysis in kidneys of stone forming patients as well as in kidneys of non-stone formers. In most samples calcifications were intratubular in the collecting ducts near the papillary tip. 1-2 micron sized particles lay in a gelatinous substance on the epithelium. The only difference in crystal composition is the higher phosphate content in the kidneys of the non-stone forming group. A correlation between the element concentration of the tissue and the occurrence of microliths is given by the cadmium content of the kidney samples. Both groups showed higher cadmium values in the cortex or medulla when crystals were found in the corresponding papillary samples. Urine supersaturation with respect to calcium oxalate was higher in the stone forming group caused by a higher calcium and oxalate but a lower magnesium excretion.

Calcinosis↗
PubMedDate not supplied

Electron microscopy of isolated human hepatocytes. (Micromethods for scanning and transmission electron microscopy).

We have investigated, by scanning and transmission electron microscopy (SEM and TEM), the cell surface morphology of isolated human hepatocytes. For this purpose, liver cells were mechanically isolated from surgical or needle liver biopsies, fixed in 3% glutaraldehyde and post-fixed in 2% osmium tetroxide. In order to handle a low number of cells, a particular procedure for harvesting hepatocytes on coverslips has been developed for SEM and an in situ embedding procedure in polyethylene-embedding capsules was applied for TEM. A rough membrane exhibiting short, uniform microvilli and pores of 0.1 mu in diameter was the main feature of isolated liver cells. Furthermore, single hepatocytes showed no polarity and junctional or bile canaliculus remnants were rarely observed. However, differences in surface configuration were noted in relation to culture conditions, such as oxygen and temperature during isolation procedures. SEM, when controlled by TEM for intracellular preservation, is proposed as a reliable method for screening small quantities of hepatocyte suspensions, for intact cells and for the study of surface configuration under experimental conditions.

Cells, Cultured↗