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Biomedical subjects

P Banks

Publications and source records attributed to P Banks.

At least 127 records · Page 7Linked to original sources
PubMed1969

The re-distribution of cytochrome oxidase, noradrenaline and adenosine triphosphate in adrenergic nerves constricted at two points.

1. The experiments correlate certain changes in the ultrastructure of cat hypogastric nerves constricted at two points with the distribution of a mitochondrial enzyme (cytochrome oxidase), noradrenaline (stored in some of the vesicles with an electron dense core, i.e. granular vesicles) and adenosine triphosphate (ATP) (present in noradrenaline storage granules, mitochondria and the soluble fraction of the axon).2. Noradrenaline (NA) and granular vesicles accumulated proximal but not distal to both constrictions. The total amount of NA and the concentration of granular vesicles above the first constriction was greater than that present in a similar piece of normal nerve, indicating that the cell body was continuing to produce the transmitter despite injury to its axon. The granular vesicles proximal to the first constriction were found in swollen or distorted axons and in new axonal outgrowths. It was concluded that the movement of NA in these constricted nerves was only centrifugal in direction.3. Mitochondria and cytochrome oxidase accumulated on both sides of the two constrictions, indicating a bi-directional movement of mitochondria in the damaged axons. The possibility that some of the increase in the cytochrome oxidase could be related to an increase in the number of mitochondria in cells other than neurones is considered.4. The adenosine triphosphate content increased on both sides of the two constrictions. This increase developed more slowly and was less marked than that of the other two substances.5. It was concluded that (a) there was a close correlation between the behaviour of noradrenaline and granular vesicles and between cytochrome oxidase and mitochondria, (b) the dense cored vesicles and the mitochondria moved independently of one another and at different rates after constriction of non-myelinated axons, (c) while some of the changes may be attributed to an obstruction to the free movement of axoplasm others may be due to an active reaction to axonal injury, and (d) localized intraaxonal synthesis of noradrenaline and cytochrome oxidase did not occur between the two constrictions.

Adenosine Triphosphate↗
PubMed1969

Sodium ions and the secretion of catecholamines.

1. Perfusion of bovine adrenal glands with a potassium-free Tyrode solution results in an increased spontaneous release of catecholamines and an increased response to stimulation with carbamylcholine.2. Perfusion with a Tyrode solution containing 70 mM-KCl causes a marked secretion of catecholamines and a subsequent inhibition of secretion in response to stimulation with carbamylcholine.3. Perfusion with sodium-free media abolishes or severely reduces the secretory response of the gland to carbamylcholine and to 70 mM-KCl although the basal secretion shows an initial rise.4. Perfusion with sodium-deficient media permits some retention of the secretory response.5. A possible role for intracellular sodium ions in the secretion of catecholamines is discussed.

Adrenal Glands↗
PubMed1967

The effect of ouabain on the secretion of catecholamines and on the intracellular concentration of potassium.

1. Perfusion of bovine adrenal glands with 0.1 mM ouabain is accompanied by a doubling of the spontaneous rate of release of catecholamines and by a 66% increase in the response to stimulation with carbamylcholine.2. Perfusion with ouabain (0.1 mM) reduces the intracellular content of potassium from 106 to 63 mM.3. The effect of ouabain on catecholamine secretion is dependent upon the presence of Ca(2+) ions in contrast to the effect upon the potassium content which is not dependent upon the presence of calcium.4. Ouabain has no effect on the release of catecholamines from isolated chromaffin granules both in the presence and absence of Ca(2+) ions.5. A possible relationship between the secretion of catecholamines and the concentration gradient of potassium across the cell membrane is discussed.

Journal Article↗
PubMed1966

The release of adenosine triphosphate catabolites during the secretion of catecholamines by bovine adrenal medulla.

1. AMP, adenosine, inosine and hypoxanthine were present in perfusates collected from bovine adrenal glands during periods when catecholamine secretion was evoked by injections of carbamoylcholine. 2. The molar ratio of catecholamines to ATP-catabolites present in the perfusates was similar to that of catecholamines to ATP in chromaffin granules. 3. ATP added to the perfusing medium was extensively degraded during passage through bovine adrenal glands. 4. The mechanism of catecholamine secretion is discussed.

Adenine Nucleotides↗
PubMed1965

Effects of stimulation by carbachol on the metabolism of the bovine adrenal medulla.

1. A method is described that has made it possible to achieve a great decrease in the catecholamine and adenine nucleotide contents of the perfused bovine adrenal gland by the infusion of carbachol. 2. Although the catecholamines secreted were recovered in the perfusion medium, no evidence was obtained that the nucleotides are secreted by the gland. 3. It is concluded that the secretion of catecholamines is accompanied by extensive chemical alteration of the adenine nucleotides of the chromaffin granules. 4. The secretory response and the spontaneous release of catecholamines depends on the presence of Ca(2+) in the perfusing Tyrode solution. 5. Anoxia does not have a significant effect on the carbachol-induced secretion of catecholamines. 6. Strips of bovine adrenal medullary tissue perfused with oxygenated Tyrode solution show an increased oxygen consumption when carbachol is added.

Journal Article↗
PubMedDate not supplied

Intrusiveness of illness and quality of life in young women with breast cancer.

Our objective was to test a theoretical model that explains quality of life as a function of the intrusiveness of illness encroaching on the different domains of one's life. The intrusiveness of illness is explained not only by disease and treatment related factors, but also by one's psychological and social resources (Devins, 1994). To investigate this issue, a sample of 336 women aged 50 and under, recently diagnosed with breast cancer were interviewed in their homes. Consistent with Devins' model, intrusiveness of illness mediated the effect of disease and treatment factors on quality of life. Contrary to his model, some treatment factors also had direct effects while social and psychological factors had only direct effects on quality of life. Neither time post-diagnosis nor type of treatment affected the psychological component of quality of life.

Adaptation, Psychological↗
PubMedDate not supplied

Use of fluorescence polarization detection for the measurement of fluopeptidetm binding to G protein-coupled receptors.

G protein-coupled receptors (GPCRs) represent the single largest molecular target of therapeutic drugs currently on the market, and are also the most common target in high throughput screening assays designed to identify potential new drug candidates. A large percentage of these assays are now formatted as radioligand binding assays. Fluorescence polarization ligand binding assays can offer a non-rad alternative to radioligand binding assays. In addition, fluorescence polarization assays are a homogenous format that is easy to automate for high throughput screening. We have developed a series of peptide ligands labeled with the fluorescent dye BODIPY TMR whose binding to GPCRs can be detected using fluorescence polarization methodology. BODIPY TMR has advantages over the more commonly used fluorescein dye in high throughput screening (HTS) assays due to the fact that its excitation and emission spectra are red-shifted approximately 50 nm relative to fluorescein. Assays based on BODIPY TMR ligands are therefore less susceptible to interference from tissue auto-fluorescence in the assay matrix, or the effects of colored or fluorescent compounds in the screening libraries. A series of BODIPY TMR labeled peptides have been prepared that bind to a range of GPCRs including melanin concentrating hormone, bradykinin, and melanocortin receptors. Conditions have been optimized in order to utilize a comparable amount of receptor membrane preparation as is used in a radioligand binding assay. The assays are formatted in 384-well microplates with a standard volume of 40 microL. We have compared the assays across the different fluorescence polarization (FP) readers available to determine the parameters for each instrument necessary to achieve the required precision.

Binding, Competitive↗