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V E Ghazarossian

Publications and source records attributed to V E Ghazarossian.

10 recordsLinked to original sources
PubMed1990

Sub-femtomole quantitation of proteins with Threshold, for the biopharmaceutical industry.

The Threshold system provides for rapid quantitation of a variety of analytes at sub-femtomole levels, which is fewer than 6 x 10(8) molecules. The operating principles of the measurement system will be described, including the means for chemical modulation of the signal and the subsequent signal detection utilizing a proprietary silicon sensor. The Immuno-Ligand Assay is a universal ligand-binding assay system which provides quantitative measurement of proteins (including antibodies) in a variety of biological media. Assay performance will be described, along with data demonstrating sensitivity, precision and accuracy, for a variety of analytes of interest to the biopharmaceutical industry.

Animals↗
PubMed1985

Fiber optic probe cytometer.

An optical fiber probe is used to both excite and collect fluorescence from a suspension of cells. The configuration of the probe is such that one or a few cells are sensed at a time, with a convenient cell concentration. With fluorescently labeled antibodies to cellular antigens, the fiber optic cytometer is able to identify the presence of a specific set of cells with high sensitivity.

ABO Blood-Group System↗
PubMed1981

Dynorphin immunocytochemical localization in brain and peripheral nervous system: preliminary studies.

Using antisera specific for the opioid peptide dynorphin, we have carried out immunocytochemical studies of the distribution in rat brain and periphery. In the central nervous system, cells that stain positively for dynorphin are found in the supraoptic nucleus, with less-well-stained cells in the paraventricular nucleus of the hypothalamus. Few positive fibers were detected in brain, suggesting problems with fixation and preservation of antigenicity. In pituitary no staining was seen in the anterior and intermediate lobes but heavy staining was detected in the posterior lobe. In the guinea pig, adrenal chromaffin cells stained with dynorphin antisera. Staining of these cells could be blocked with excess of dynorphin-(1-13) or either enkephalin. Radioimmunoassays revealed a great excess of the enkephalins in the adrenal, suggesting cross competition between dynorphin antiserum and adrenal medullary enkephalin. Finally, the dynorphin antiserum stained a complex of fibers in guinea pig ileum. Staining of these fibers could be blocked by moderate amounts of enkephalin as well as by smaller amounts of dynorphin-(1-13). We conclude that in some places (brain and pituitary) dynorphin exists separately from leucine-enkephalin. In other parts of brain and in the periphery the relationship between dynorphin and the enkephalins is very complex and requires further study and improved antisera.

Animals↗
PubMed1980

Levels of immunoreactive dynorphin in brain and pituitary of Brattleboro rats.

The very potent opioid peptide, dynorphin, has recently been shown by radioimmunoassay and immunocytochemical techniques to be selectively concentrated in the pars nervosa of pituitary, suggesting a possible association of dynorphin with the neurohypophyseal hormones, vasopressin and oxytocin. In this study, we report that pituitary and brain contents of immunoreactive dynorphin in homozygote Brattleboro rats (unable to synthesize vasopressin) are similar to those in heterozygote animals and in normal Long-Evans rats. Thus, the syntheses of immunoreactive dynorphin and vasopressin in the hypothalamo-hypophyseal tract appear to be independently regulated.

Animals↗
PubMed1980

Immunoreactive dynorphin in pituitary and brain.

Distribution of the potent opioid peptide dynorphin has been determined in pituitary gland (pig, beef, rat), in the various regions of rat brain, and in rat spinal cord, by using a highly specific antiserum. By gel permeation chromatography in 4 M guanidine, the porcine pituitary immunoreactivity is found in a major peak of apparent molecular weight about 1700 and a minor peak of about 3400. Similar peaks are found in rat pituitary extracts, whereas rat brain contains, in addition, two peaks of larger apparent molecular weight. In the pituitary, immunoreactive dynorphin is found predominantly in pars nervosa. In the central nervous system, it is distributed widely, with highest concentrations in hypothalamus, medulla-pons, midbrain, and spinal cord. Although dynorphin contains leucine-enkephalin, the regional distribution of dynorphin is different from that of enkephalin or of any other known opioid peptide.

Animals↗