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G Valet

Publications and source records attributed to G Valet.

99 records · Page 6Linked to original sources
PubMedDate not supplied

Electromagnetically induced fluid streaming as a possible mechanism of the biomagnetic orientation of organisms.

The results show that both the direction and the intensity of the geomagnetic field can be sensed within the chamber of a Zeiss Cytopherometer. This suggests that electromagnetically induced fluid streaming might play a role in the perception of the geomagnetic field by organisms, although it is not clear at present in which organ the perception occurs. A basic requirement for such an organ would be an anisotropy of cells or cellular structures. The nervous system with its parallel axons, or specific cells associated with the nervous system, could thus be possible locations of the sensitivity towards magnetic fields.

Electromagnetic Fields↗
PubMedDate not supplied

Predictive medicine by cytomics: potential and challenges.

Predictive medicine by cytomics represents a new concept which provides disease course predictions for individual patients. The predictive information is derived from the molecular cell phenotypes as they are determined by patient's genotype and exposure to external or internal influences. The predictions are dynamic because they are therapy dependent. They may provide a therapeutic lead time for preventive therapy or for the diminution of disease associated irreversible tissue damage. Multiparametric data from cytometry, multiple clinical chemistry assays, chip or bead arrays serve as input for an algorithmic data sieving procedure (http://www.biochem.mpg.de/valet/classif1.html). Data sieving enriches the discriminatory parameters in form of standardized data masks for predictive or diagnostic disease classification in the individual patient (http://www.biochem.mpg.de/valet/cellclas.html). Besides predictive and diagnostic utility, the data patterns can be used in a bottom-up approach for the development of scientific hypotheses on disease inducing mechanisms in complex inflammatory, infectious, allergic, malignant or degenerative diseases.

Diagnosis, Computer-Assisted↗
PubMedDate not supplied

Past and present concepts in flow cytometry: a European perspective.

The development of flow cytometric instrumentation, methods and research concepts in Europe has been a continuous driving force for the general scientific advancement in this area over the years. This review addresses early European concepts of continuing interest with regard to instrumentation, data analysis, clinical and eperimental DNA analysis, cell function and microbiology at their worldwide first appearence while flow cytometric immunology and immunophenotyping will be covered separately. Flow cytometry represents an efficient approach to the enormous complexity of molecular cell architecture and cell function by the analysis of apparent molecular cell phenotypes in heterogeneous cell samples. The present merger of flow and image cytometry into the method independent cytomics discipline increases the potential of cell analysis very significantly. It opens the way for predictive medicine as well as for predictive cytopathology and predictive cytology in everyday clinical and medical practice. Current progress is driven by joint advances in molecular fluorescence technologies and instrument development. This complements the analysis of genome sequence information in an efficient way.

Apoptosis↗
PubMedDate not supplied

Potential and challenges of a human cytome project.

BACKGROUND: The elucidation of the molecular pathways from the 20-40.000 genes of the sequenced human genome via investigation of genetic networks and molecular pathways up to the cellular and organismal phenotypes is highly complex and time consuming. STRATEGY AND GOALS: The proposed upside-down research strategy of a human cytome project accesses the expressed molecular cell phenotypes by differential screening, for example of diseased versus healthy, or undifferentiated versus differentiated cells to obtain information on disease or differentiation related molecular hotspots at the single cell level. The genome serves as inventory of the biomolecular capacities of organisms while the mechanisms of genome realisation are initially entirely bypassed. Detected molecular hotspots are further investigated by backward directed systems biology, including molecular pathway modelling to elucidate disease related molecular pathways. New drug targets may be identified to specifically influence such pathways. Differential screening provides, in addition, individualized disease course predictions for everyday medicine, in form of "predictive medicine by cytomics." The early recognition of future disease complications enables an immediate application of preventive therapies. This is likely to lower disease related irreversible tissue destruction and adverse drug reactions and will allow to individually optimize patient therapy. OUTLOOK: Immediate medical use, facilitated access to the detection of new drug targets, increased research speed and the stimulation for advanced technological developments represent major driving forces for the efforts to establish a human cytome project.

Cell Biology↗
PubMedDate not supplied

Effect of pregnenolone-16alpha-carbonitrile (PCN) on rat liver.

One time i.p. injections of 5 -20 mg Pregnenolone-16alpha-carbonitrile (PCN) effects the mitotic activity of rat liver cells during a time period of 24 hours to be 20 times higher than the normal mitotic rate. This, however, does not result in an measurable increase of cell numbers and cell volumes. Furthermore, total liver DNA, RNA, protein and dry-weight remain unchanged. The injection of 7 times 10 mg PCN also results in the elevation of the mitotic rate. Return of the elevated mitotic rate to base level takes 18 days from the time the last injection of PCN was administered. During this time the number and the average volume of liver cells increases by 28% and 30%, respectively. The dry weight of liver and tetraploid nuclei increase in number, whereas RNA- and protein content remains unchanged. All parameters have reached the base line after 4 - 6 weeks following the last injection of PCN. No histological changes were observed after multiple doses of PCN that cause hyperplasia and hypertrophy of liver tissue. Hypertrophy of liver cells follows the observed hyperplasia and therefore is not expected to be the cause of the hyperplastic processes.

Animals↗