Search PubMed⌕ Search

Biomedical subjects

A Conforti

Publications and source records attributed to A Conforti.

At least 55 records · Page 3Linked to original sources
PubMed1984

Comparative effects of urapidil, prazosin, and clonidine on ligand binding to central nervous system receptors, arterial pressure, and heart rate in experimental animals.

We studied the effects of urapidil, clonidine, and prazosin on ligand binding to central nervous system receptors in rats and on arterial pressure and heart rate in chloralose-anesthetized cats. Ligand binding studies indicated that urapidil had 90 times greater affinity for alpha 1 than for alpha 2 adrenergic receptors. Administration of urapidil (129 micrograms) into the cerebroventricles of cats revealed no effect after lateral ventricle injection, a decrease of 9.7 +/- 3.0 mm Hg after fourth ventricle injection, and an increase of 10.8 +/- 2.2 mm Hg after restriction of the drug in the forebrain ventricles. Clonidine (30 micrograms) produced hypotension and bradycardia after injection into the lateral ventricle. Prazosin was ineffective after cerebroventricular injection. Intravenous administration of 0.22, 0.67, and 2.00 mg/kg urapidil produced dose-dependent decreases in arterial pressure that were associated with blockade of alpha 1 adrenergic receptors. Intravenous administration of prazosin elicited the same response. Clonidine (10 micrograms/kg, intravenously produced an initial increase in arterial pressure that was unaffected by pretreatment with urapidil or prazosin. These results suggest that urapidil produces hypotension by an action on the peripheral vasculature and in the hindbrain. The peripheral effect involves blockade of alpha 1 adrenoceptors.

Animals↗
PubMed1984

Nuclear changes in Friend erythroleukemia cells treated with arabinosylcytosine in vitro.

Friend erythroleukemia cells (strain 745 A 19) grown in DME medium were treated with arabinosylcytosine (Ara-C) for 12 hours. After treatment, the cells were partly fixed and prepared for electron and light microscopy. This treatment produced a substantial increase in the number of malignancy-associated changes (MAC) present in untreated cells, of the nuclear "holes" and of the mean nuclear masses/cell ratio. At the same time, decrease in the growth rate was evident. Treatment with this antiblastic drug seems to be suitable for inducing deeper morphological changes related to neoplasia in transformed cells.

Cell Division↗
PubMed1983

Serum copper and ceruloplasmin levels in rheumatoid arthritis and degenerative joint disease and their pharmacological implications.

Serum copper concentration and ceruloplasmin activity were measured in patients with clinically established rheumatoid arthritis (R.A.) during the active phase, in patients with degenerative joint disease (D.J.D.) and in normal subjects. Copper and ceruloplasmin serum levels are significantly increased (P less than 0.01) in the arthritic group, but not in the degenerative joint disease group. Copper and ceruloplasmin levels are high significantly correlated in all the groups. This parallel enhancement of serum copper and ceruloplasmin in R.A. is commented in view of a possible protective role of endogenous copper and/or ceruloplasmin in inflammation.

Arthritis, Rheumatoid↗
PubMed1983

Copper metabolism during acute inflammation: studies on liver and serum copper concentrations in normal and inflamed rats.

1 The concentration of copper in serum and liver was determined by atomic absorption spectrophotometry in a study performed on normal rats of either sex and in female rats with carrageenan-induced pleurisy. 2. In the normal animal, total serum copper concentration is significantly higher in female rats, and appears to be higher in mature animals in females. 3 In normal rats of either sex, liver copper concentration undergoes daily variations which are inversely related to the weight of the organ and which leave constant the total amount of metal in the liver. Moreover a day to day non-cyclic variability of liver copper concentration and liver weight was observed. 4 This first set of data showed that comparison with time control was essential. 5 In the inflamed rat, a significant rise of total serum copper at 22, 48 and 72 h after the induction of inflammation was observed. From 96 h up to 240 h post-injection no significant differences were evident. 6 Total liver copper content did not change in the inflamed rats. 7 During acute inflammation in the rat, the copper needed for the increased synthesis of caeruloplasmin is supplied without depletion of liver copper stores.

Animals↗
PubMed1982

Copper and ceruloplasmin (Cp) concentrations during the acute inflammatory process in the rat.

We have measured the concentration of copper and ceruloplasmin in serum of rats with carrageenan foot-oedema and in serum and exudate of rats with carrageenan pleurisy. Both serum copper and ceruloplasmin were found to increase in both models of inflammation. In these experimental conditions we have shown a strong positive correlation between copper and ceruloplasmin, in the serum of both normal and inflamed rats.

Acute Disease↗
PubMed1980

The acute inflammatory process in copper-deprived rats.

Copper is clearly involved in experimental and human inflammation, as suggested by a large body of data, some of which obtained in our own laboratories. With the purpose to further investigate the role of copper in the inflammatory process, we have studied the development of carrageenan foot oedema and carrageenan pleurisy in rats treated with a copper-deficient diet according to the following schedule: (1) foot oedema in rats maintained on a 0.4 p.p.m. copper-deficient diet for 1 and 3 months; (2) foot oedema and pleurisy in rats maintained on a 0.2 p.p.m. copper-deficient diet for 1 month; (3) foot oedema and pleurisy in rats maintained on a 0.6-0.8 p.p.m. copper-deficient diet for 5 months. With these experiments we have shown an enhancement of the inflammatory reaction which, apparently, is both time and copper content dependent. The possibility that endogenous copper could play a key role in modulating the acute inflammatory process is discussed.

Acute Disease↗
PubMed1979

The pigmentary system of planaria. I. Morphology.

The pigmentary system of the planaria, Dugesia gonocephala s.l. (Platyhelminthes, Turbellaria, Tricladida), has been studied by light and electron microscopy. The system consists of granules contained in chromatophore-like cells embedded in the parenchyma. The cell processes penetrate between the muscle layers and extend to the sub-epidermal basal lamina. The nature of the pigment and the comparative anatomical significance of the chromatophore structure is discussed.

Animals↗
PubMed1979

The pigmentary system of planaria. II. Physiology and functional morphology.

The pigmentary system of the planaria, Dugesia gonocephala s.l. (Platyhelminthes, Turbellaria, Tricladida), consists of granules contained in chromatophore cells distributed in the parenchyma tissue. The administration of MSH release-inhibiting Factor (M.I.F.) leads to an easily observable general decolouration of the animal due to the migration of the pigment granules towards the deeper-lying cell nucleus. In planarians bisected transversely through the pharyngeal region, the decolouration occurs only in the cephalic segment, and the caudal segment remains dark. When, however, the decapitated caudal segment regenerates a head region, a decolouration response occurs when exposed to M.I.F. The significance of these results is discussed, and an hypothesis on the hormonal regulation of the pigmentary system is proposed.

Animals↗
PubMed1979

Concerning the role of endogenous copper in the acute inflammatory process.

The development of two models of acute inflammation (carrageenan-induced foot oedema and pleurisy) was studied in rats after 1 month of a 0.2 p.p.m. copper-deficient diet and after 5 months of a 0.6-0.8 p.p.m. copper-deficient diet. A 'pro-inflammatory' effect of copper deficiency was observed with the 0.2 p.p.m. diet, whilst no effect was evident following the 0.6-0.8 p.p.m. copper deficient diet. These results are briefly commented upon.

Acute Disease↗
PubMed1978

Ultrastructural nuclear changes in human lymphocytes following arabinosylcytosine treatment in vitro.

Human lymphocytes were separated by centrifugation and grown for 48--72 h in TC 199 medium. Synchronous cells, obtained by the addition of colchicine, were treated with arabinosylcytosine (Ara-C), an antimitotic substance which is known to produce nuclear changes in vivo and in vitro. In this case, alterations in the nuclear envelope closely resembling the malignancy associated changes described in human leukaemic cells were observed. The results allow us to suggest that such alterations may be due to a cellular derangement involving the renewal of the nuclear envelope in th G1 phase of the mitotic cycle.

Cell Nucleus↗
PubMed1977

Subcellular reactions to injury. I. Ultrastructural and biochemical investigations on the hepatic cellular damage produced by haemorrhagic shock in dogs.

The ultrastructural changes produced by haemorrhagic shock in hepatocytes have been studied in dogs. The associated biochemical and biophysical system alterations allow us to propose a unitary pathogenetic mechanism of the cellular injury based on oxygen deprivation and its effect on the function and structure of the cellular compartments.

Animals↗
PubMed1977

Serum calcitonin and blood mineral interrelationships in normal children aged six to twelve years.

Simultaneous measurements of serum immunoreactive thyrocalcitonin (iTCT), immunoreactive parathyroid hormone (iPTH), calcium, inorganic phosphate, magnesium, and alkaline phosphatase were made in 37 normal children whose ages ranged from 6-12 years. Between the ages of 6 and 12 there is a statistically significant rise in serum iTCT levels (r = 0.4638; P less than 0.01), and a fall in serum iPTH levels (r = 0.4976; P less than 0.01). There is a highly significant inverse correlation between serum iTCT and iPTH levels (r = 0.5248; P less than 0.005). Serum iTCT levels were inversely correlated with phosphate levels (r = 0.4989; P less than 0.01), the latter being age dependent and falling significantly between the ages of 6 and 12 (r = 0.4802; P less than 0.001). There was no significant relationship between serum calcium levels and iTCT, iPTH, or age. Serum magnesium levels were not correlated with calcium, iTCT, or iPTH levels.

Adult↗
PubMed1977

[Copper and nervous system. An experimental study (author's transl)].

Sodium azide is known to produce alterations in mammalian copper proteins, thus rendering them unable to bind exogenous metal, which remains in the "labile pool" condition. Continuous administration of sodium azide at LD50 for 30 days causes copper accumulation in several tissues and even in the nervous system, with characteristic changes in neurones and glial cells, very much resembling the alterations observed in Wilson's disease. Dietary copper administration, on the contrary, though raising the level of tissue-bound metal, does not produce cellular damage. These findings allow us to suppose that sodium azide may alterate the coppper chelating proteins in the tissues, especially in the nervous system, thus causing the storage of cell-toxic "labile pool" metal. The pathogenesis of Wilson's disease and the problem of "pathoclisis" in the nervous system are debated.

Animals↗
PubMed1976

Ultrastructural changes in human leukemic cell nuclei.

The ultrastructural changes of human leukemic cell nuclei have been investigated. Particular attention is paid to the alteration of the nuclear envelope and its constituents, i.e., the pores and the Zonula Nucleum Limitans which appear constantly involved in these pathologic processes. An alteration of the relationship between the components of the nuclear envelope and the chromatin itself may be responsible for the appearance of the most nuclear changes.

Cell Nucleus↗
PubMed1976

Ultrastructural hypoxic changes in Ammon's horn and Purkinje cells.

Guinea pigs were exposed for varying periods to different degrees of hypoxia by respiration of controlled mixtures of O2-N2 and the CNS subjected to both light and electron microscopic examination after aldehyde fixation by perfusion. The subacute anoxia experiments revealed an alteration in the rough endoplasmic reticulum of the Purkinje cells consisting of the formation of 'paired cisternae'. In the chronic anoxia experiments, small ultrastructural alterations of the same cells were found in association with the appearance of monoparticulate glycogen. The authors debate the significance of these ultrastructural alterations in relation to the damage found in other organs.

Animals↗