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G Rossolini

Publications and source records attributed to G Rossolini.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Functional interrelationships in aging processes: alterations and reversibility.

The problem of assessing the relevance of the reversibility of age-related functional alterations for aging studies has been presented. Transduction mechanisms of adrenergic stimulation have been chosen as the target of age-related changes and thymus as the effector of some corrective interventions performed at advanced age. Both alterations of adrenoceptor characteristics and their reversibility have been reviewed. beta-adrenoceptors have been studied in organs bearing only one subtype of receptors or both, revealing an age-related decrease in density only in the beta1-subtype. It has been shown that a similar age-related decrease is present in alpha1-adrenoceptor density. Such alterations are corrected by grafting a neonatal thymus into old mice. On the contrary, thymus fails to correct the alteration of T4-induced upregulation of beta-adrenoceptors indicating some limits to its corrective effect when the net of functional interrelationships becomes relatively complex. Both failures and successes of thymic grafts and thymic extracts in reversing age-related changes are discussed taking into account the effects induced on the life span of the animals. Different unsolved problems stemming from the previous considerations are also presented. Among them the controversial question about linearity and non-linearity of biological parameters presumed to be good indices of aging is discussed, with the aid of a simple model as a schematic example.

Journal Article↗
PubMedDate not supplied

Excitatory amino acid receptors in the prefrontal cortex of aging mice.

The zones of the prefrontal cortex of Balb/c mice were tested for age-related changes of the ionotropic excitatory amino acid receptors density, together with zones of the dorsal cortex. Kainate, N-methyl-D-aspartate, and amino-3-hydroxy-5-methyloxazole-4-propionate sites were measured by slice receptor binding techniques in cortical zones from animals at the age of 6, 12, 18, and 24 months. An increase of the N-methyl-D-aspartate sites was detected in the medial prefrontal zone of mid-aged animals and was followed by a decrease at old age; a decrease of the N-methyl-D-aspartate and kainate sites was found for the medial dorsal (cingulate) cortex at old age. The age-related changes of receptor densities in the different cortical areas seem unrelated in origin. The sites decrease in the cingulate cortex could affect the transfer of the prefrontal cortex activity toward limbic structures.

Aging↗
PubMedDate not supplied

Assay of estrogen and progesterone receptors in small samples of breast cancer: I. Mathematical analysis of total binding data.

The quantitative determination of Estrogen and Progesterone receptors in breast cancer is performed using about 500 mg of tissue. Such an amount of tissue sample is available with ever increasing difficulty. In the present paper a mathematical method of analysis of the total (specific+nonspecific) binding data is given. In this way about 50% of tissue can be saved as only one set of test tubes is required; in fact, the method does not need the second set of tubes used to determine nonspecific binding in the conventional assay. Additional advantages from the statistical point of view are also presented.

Animals↗
PubMedDate not supplied

Determination of the optimal conditions to study DNA synthesis in cultures of mouse hepatocytes.

Mouse hepatocytes undergo profound changes during aging, such as increased nuclear volume, occurrence of tetraploid nuclei and impaired DNA synthesis following in vivo adrenergic stimulation. These alterations have been found reversible by implanting a neonatal thymus into old animals. In the present paper we studied the optimal experimental conditions in order to investigate the mechanisms of such actions in vitro. Unfortunately, in fact, most of data in the field comes from experiments on rats. Thus, we examined DNA synthesis of hepatocytes from mice cultivated in presence of neonatal calf serum only, or after the addition of the beta-adrenergic agonist isoproterenol or the beta-adrenergic antagonist propranolol. DNA synthesis in hepatocytes from young Balb/c-nu mice shows a peak between 36 and 48 h even in the absence of any specific stimulation other than newborn calf serum. The addition of isoproterenol does not modify the DNA synthetic pattern, while propranolol causes a slight but statistically significant decrease in 3H-thymidine incorporation. Results are compared with those obtained from other authors in rats.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Modelling survival kinetics for red blood cells.

In the attempt to improve the analysis of red blood cell survival kinetics we evaluated the ability of a new mathematical model of survivorship in fitting hemolysis curves. This model contains two parameters omega and S0 related to deterministic and stochastic components of mortality kinetics, respectively. In this paper, firstly, we show that the model can be usefully applied in the analysis of hemolysis kinetics of very different life span and shape. Then, we check the capability of fitting the model to experimental lysis curves derived from human erythrocytes incubated at different temperatures: our results demonstrate that there is good agreement between experimental and theoretical data.

Computer Simulation↗