Biomedical subjects

P Metzler

Publications and source records attributed to P Metzler.

5 recordsLinked to original sources

PubMed2005

High-density electrode array for imaging in vitro electrophysiological activity.

The development of a high-density active microelectrode array for in vitro electrophysiology is reported. Based on the Active Pixel Sensor (APS) concept, the array integrates 4096 gold microelectrodes (electrode separation 20 microm) on a surface of 2.5 mmx2.5 mm as well as a high-speed random addressing logic allowing the sequential selection of the measuring pixels. Following the electrical characterization in a phosphate solution, the functional evaluation has been carried out by recording the spontaneous electrical activity of neonatal rat cardiomyocytes. Signals with amplitudes from 130 microVp-p to 300 microVp-p could be recorded from different pixels. The results demonstrate the suitability of the APS concept for developing a new generation of high-resolution extracellular recording devices for in vitro electrophysiology.

Animals↗

PubMed2002

[Memory disorders after unilateral cerebral lesions].

In contrast to the amnestic syndrome, unilateral hemispheric lesions are mostly connected with selective memory deficits, which are related to either verbal or visual-spatial information. Clinical studies concerning this are mostly about patients with temporal lobe epilepsy. Almost all studies found that significantly worse verbal memory deficits appeared before or after left temporal lobectomy. In contrast to these outcomes, the results concerning right temporal lobectomy (RTL) are nonuniform. There are studies that cannot prove figurative memory deficits before or after RTL and others that ascertain a correlation between RTL and figurative memory deficits. Mean values are always compared with random samples of left and right hemispheric patients. In contrast, the presented study assumes a clinical isolated case and analyses a random sample of neurological patients with different genesis with a standardized memory test (Berlin Amnesia Test, or BAT). As a result, a significant correlation between left hemispheric lesions and verbal memory deficits as well as right hemispheric lesions and visual-spatial memory deficits can be proven. Possible reasons for these differing results with visual-spatial memory deficits are still under discussion.

Adult↗

PubMed2001

Insulin and IGF-1 induce different patterns of gene expression in mouse fibroblast NIH-3T3 cells: identification by cDNA microarray analysis.

The IGF-1 receptor and the related insulin receptor are similar in structure and activate many of the same postreceptor signaling pathways, yet they mediate distinct biological functions. It is still not understood how the specificity of insulin vs. IGF-1 signaling is controlled. In this study, we have used cDNA microarrays to monitor the gene expression patterns that are regulated by insulin and IGF-1. Mouse fibroblast NIH-3T3 cells expressing either the wild-type human IGF receptor or the insulin receptor were stimulated with either IGF-1 or insulin, respectively. Thirty genes, 27 of which were not previously known to be IGF-1 responsive, were up-regulated by IGF-1 but not by insulin. Nine genes, none of which was previously known to be insulin responsive, were up-regulated by insulin but not by IGF-1. The IGF- and insulin-induced regulation of 10 of these genes was confirmed by Northern blot analysis. Interestingly, more than half of the genes up-regulated by IGF-1 are associated with mitogenesis and differentiation, whereas none of the genes specifically up-regulated by insulin are associated with these processes. Our results indicate that under the conditions used in this study, IGF-1 is a more potent activator of the mitogenic pathway than insulin in mouse fibroblast NIH-3T3 cells.

3T3 Cells↗

PubMed2000

[Are psychiatric illnesses adequately considered in distribution of nursing care levels according to the nursing care insurance law? Evaluation using a new scale for evaluating need for nursing care by senior citizens].

The object of our study is the evaluation of care needs of senior citizens and the adjustment of certain stage of care according to the German Health Care Act ("Pflegeversicherungsgesetz"). For assessment of care needs we developed a new rating scale (BPS). Factor analysis of the rating scale showed 5 dimensions: (1) "Psychoorganic Syndrome" (Dementia), (2) "Physical Care Needs", (3) "Lack of Social Skills", (4) "Aggressiveness" and (5) "Depression". The sample size is N = 1739, mean age 82.5 years. A statistically significant partial correlation of the extent of care needs as indicated by the stage of care described by BPS dimensions was found only for dimension (2) "Physical Care Needs" (r = 0.50). Cluster analysis resulted in distribution of the whole sample into 6 discriminable groups, according to their syndrome specificity (BPS profiles). Additionally clusters are different regarding the severity of need for care. It is obvious, analyzing the adjustment of stages of care within clusters, that psychiatric relevant disturbances contribute substantially to this adjustment. Nevertheless this finding is valid only for aged people, who receive regular care by ambulant or home services, and can not be transferred to senior citizens cared by their families.

Aged↗

PubMed1991

[The concept of amnesia and quantitative assessment of amnesic disorders].

This article presents first a short historical overview of the different viewpoints concerning psychiatric approaches to define the concept "amnesia" (Ribot, Korsakow, K. Schneider, Bleuler, Bonhoeffer et al.). A generally accepted result is the differentiation between retrograde and anterograde amnesia. Research work of the last two decades has focussed on the experimental investigation of anterograde amnesia, the so-called amnesic syndrome. In this context four main factors responsible for memory performance are distinguished: encoding, retrieval, forgetting and interference. One of the main results of neuropsychological research in amnesia consists in having discovered a set of symptoms or features common to most if not all forms of amnesia. These features appear regardless of etiology and locus of lesion. This set or features is described in detail in the paper. On the basis of these amnesic features a clinical test was developed, the Berliner Amnesie Test (BAT). This standardized test can be used for the assessment from mild up to severe memory disorders.

Alzheimer Disease↗