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L Piantanelli

Publications and source records attributed to L Piantanelli.

At least 55 records · Page 3Linked to original sources
PubMed1985

[The role of neuroendocrine-immunological interrelations in the development of tumors].

There is at present an experimental evidence of neuroendocrine-immunological interactions in tumor development both in experimental models and man. In fact, different hormone receptors have been found in both experimental and spontaneous tumors in animals and man. Such tumors are therefore under the influence of the neuroendocrine system. In addition, some hormone-metabolic alterations such as those observed in advancing age are often associated with a high incidence of the neoplastic growth. Interestingly, tumor incidence increases with advancing age in both man and animals and experimental tumors are more easily transplanted in old mice than in young adult mice. On the ground of these observations it can be suggested that tumor growth results from the interactive action of both the immunological and neuroendocrine systems.

Adrenal Glands↗
PubMed1984

Centrophenoxine-induced increase of beta-adrenoceptor density in brain cortex of old mice.

The influence of centrophenoxine treatment on beta-adrenoceptor density has been studied in the brain cortex of old mice. One group of 21-mth-old mice was injected intraperitoneally with 3.8 mg/day centrophenoxine daily for 5 days. A second group received the same daily treatment for 40 days. Two other groups of untreated mice of the same age served as controls. Receptor affinity showed no statistically significant changes in the four different groups investigated. As regards the receptor density, an increasing trend has been elicited between the 5-day treated mice and their controls; however, the increase was not statistically significant. The second group of old mice treated with centrophenoxine for 40 days exhibited a statistically significant increase in receptor density when compared with untreated animals. The modulation of beta-adrenoceptor density may be explained as the result of either a direct action on synaptic structure or an indirect effect mediated by thyroid hormones.

Aging↗
PubMed1984

Atenolol-induced regulation of leukocyte beta 2-adrenoceptors in hypertension.

beta 2-Adrenoceptor characteristics of human mononuclear leukocytes were assayed in hypertensive patients before and after treatment with 100 mg/day atenolol. While no changes have been observed in receptor affinity, a statistically significant increase (36%) has been demonstrated in receptor density following treatment. Blood pressure and heart rate were also measured in order to test the efficacy of the administered drug. All these parameters showed a fall in the post-treatment values. It is concluded that at therapeutic concentration, beta 2-adrenoceptors undergo up-regulation by atenolol in spite of its cardioselectivity. Such a regulation, which may represent a fundamental step in the mechanism leading to withdrawal syndrome, may, therefore, be suggested being quite widespread.

Adult↗
PubMed1983

Decreased beta-adrenergic receptor density in mononuclear leukocytes from thyroidectomized patients.

Beta-adrenergic receptor characteristics were investigated in peripheral blood mononuclear leukocytes taken from patients before and after partial thyroidectomy. In order to discriminate the effect of surgical stress per se from that of thyroidectomy, the analysis was also performed on patients before and after cholecystectomy. Receptor characteristics were determined by using dihydroalprenolol as ligand in direct equilibrium binding experiments. The binding affinity showed no changes either when two different surgical treatments were compared or when the same patient was analysed before and after the operation. On the contrary, a significant decrease in receptor density was found in thyroidectomized patients when compared pre- and post-operatively. This fall in receptor number seems to be linked with thyroid function since no statistically significant changes were observed in cholecystectomized patients in relation to surgical operation. This view is further supported by data on T3 serum levels, which show a significant fall after thyroidectomy but no statistically significant modifications after cholecystectomy. It is concluded that beta-adrenoceptor modulation plays an important role in the relationship between thyroid and beta-adrenergic system.

Adenoma↗
PubMed1982

Age-dependent decrease of beta-adrenoceptor density in the submandibular glands of mice and its modulation by the thymus.

Beta-adrenergic receptors were characterized in submandibular glands of ageing mice and old mice grafted with a neonatal thymus. No statistically significant changes of receptor affinity were found in the animal models investigated. On the contrary, receptor density showed a progressive decrease with advancing age. The age-related decrease has been found partially corrected in thymus-grafted old animals, which show a statistically significant recovery of receptor density when compared to their untreated littermates. Receptor modulation can be responsible for the age-related impairment and the thymus-dependent correction of beta-adrenergic responsiveness of submandibular glands previously observed in vivo. Hormonal balance and thyroid hormones, in particular, are suggested as being involved in the age- and thymus-dependent regulation of receptor density. In the accompanying Appendix, we describe the mathematical method used to calculate both specific and nonspecific binding from total binding data.

Aging↗
PubMed1980

[High and low affinity beta adrenergic receptor sites from submandibular glands of mice].

Beta-adrenergic receptors from submandibular glands of mice were studied by equilibrium binding experiments. Due to the fact that some discrepancies were previously observed among different author data, we compared two methods for non specific binding substruction, that represents the major source of errors in such experiments. Data were obtained strongly suggesting the presence of multiple population of binding sites and/or negative cooperativity.

Animals↗
PubMed1980

Electron-microscopic morphometric analysis of mouse liver. I. Experimental studies on the morphogenetic significance of the thymus in nude and normal mice.

Haired, nude, thymus-grafted nude and haired thymectomized Balb/c-nu mice 2 months of age were studied by electron-microscopic stereology. Each group consisted of 5 animals and a complete morphometric analysis was carried out on their livers. In the absence of the thymus there is a slowing down of the development of the whole organism. Among the liver parameters especially the nuclear ones displayed alterations. Namely, the volume of hepatocyte nuclei increased above the normal level and this phenomenon was reversed by thymus graft into the nude mice. The hepatocyte volume also increased significantly in the surgically thymectomized group, influencing all the morphometric parameters regarding mitochondria and endoplasmic reticulum, when measured per hepatocyte. On the basis of the results obtained, one can conclude that the thymus has a regulatory role in the development of hepatocyte morphology. The findings agree with the biochemical observations demonstrating non-immunological effects of the thymus on cellular development.

Animals↗
PubMed1980

Electron-microscopic morphometric analysis of mouse liver. II. Effect of ageing and thymus transplantation in old animals.

The influence of age and thymus on liver cells has been investigated by performing a complete morphometric analysis. The age-dependence was tested in three groups of mice aged 2, 12, and 24 months, while the action of the thymus was studied on 24-month-old mice grafted with neonatal thymus 30 days before the analysis was performed. Among the investigated parameters, the most considerable changes were found in the mean nuclear volume, which displayed a significant increase during ageing. The thymus was capable of reversing such an age-dependent increase when grafted into old animals. The volume of single hepatocytes also displayed an age-dependent increase which was not corrected by thymus grafting. The data presented suggest that the thymus influences the mitotic activity of the hepatocytes and further support the hypothesis that the thymus also plays an important role in non-immunological processes of ageing.

Aging↗
PubMed1980

Thymus-endocrine interactions during ageing.

The hypotesis of the thymus acting as biological clock for ageing is revisited. On the basis of data on the endocrine action of the gland, the age-dependent involution of the thymus is postulated to play a fundamental role on the deterioration of the immunological as well as the endocrine functions. Data either on beta-adrenergic responsiveness to Isoproterenol or on hormonal balance, tested on animal model with different degree of thymus efficiency, support this hypothesis.

Aging↗
PubMed1978

Age-dependence of isoproterenol-induced DNA synthesis in submandibular glands of BALB/c mice.

The age-dependency of isoproterenol (IPR) induced DNA synthesis was investigated in different organs of Balb/c mice. Although modifications of the physiological rate of DNA synthesis after IPR injection occurred also in liver and spleen, a quasi-linear decrease of the peak of IPR response with advancing age was observed only in submandibular glands. Such a decrease was observed when animals were injected with 10(-4) g IPR per g body weight, lower doses being unable to discriminate between young and old mice. In spite of some differences between mice and rats, the early appearance and linearity of the age-dependency remain common features of IPR response.

Age Factors↗
PubMed1978

Thymus-dependent reversibility of physiological and isoproterenol evoked age-related parameters in athymic (nude) and old normal mice.

In order to assess the relationship between the thymus and aging processes, a linear age-dependent parameter in mice such as the response of the submandibular gland to an injection with isoproterenol has been evaluated in athymic (nude) and thymectomized Balb/c mice. The IPR-induced DNA synthesis is reduced in both experimental groups when compared to untreated normal littermates and is recovered by grafting a neonatal thymus. Moreover, the impairment of IPR response in old animals is recovered to young levels by grafting one neonatal thymus one month before test. Neonatal thymus grafts in old recipients are also able to correct their abnormal serum levels of triiodothyronine and insulin. The influence of neonatal thymus on such non-immunological and age-related parameters suggests that this gland can control aging processes, probably through its implication with the endocrine system.

Age Factors↗
PubMed1977

Differential effect of pregnancy or gestagens on humoral and cell-mediated immunity.

The reactivity of spleen lymphocytes in a mixed lymphocyte culture and the in vivo PFC response to sheep erythrocytes have been evaluated in pregnant female mice and data compared with those observed in virgin sexually mature female mice daily treated either with progesterone or human chorionic gonadotropin (HCG) or human prolactin. The mixed lymphocyte reactivity is depressed at mid-pregnancy, whereas PFC response is increased. Comparable immunological modifications have been found in mice treated with HCG, but not in animals treated with progesterone or prolactin. The similarity between HCG treatment and pregnancy suggests that the rate of gonadotropin release may be one of the earliest events responsible for the immunological disturbances present during pregnancy, although its action on the lymphoid system seems to require the presence of the ovary. From these data and from the observation that HCG increases the PFC response also in thymusless nude female mice, it can be deduced that it acts on both T and B cells.

Animals↗
PubMed1977

Differential effect of pancreatectomy on humoral and cell-mediated immune responses.

Cell-mediated immune reactions, such as allogenic skin-graft rejection and PHA or MLC responses, and antibody synthesis against different antigens (sheep erythrocytes, Brucella antigen, bovine serum albumin) have been evaluated in rats suffering from experimentally-induced diabetes and in age-matched sham-treated controls. Cell-mediated immune reactions are strongly depressed diabetic rats. The cellularity of the thymus and of thymus-dependent areas and the number of peripheral blood lymphocytes is significantly reduced in pancreatectomized rats. Moreover, the immunological recovery from heavy cortisonization is also greatly impaired. Daily treatment with insulin may prevent these immunological alterations. By contrast, antibody responses in diabetic rats are not quantitatively altered in respect to either the number of antibody producing cells in the spleen or the circulating antibody titres. The discrepancy between the abnormality of cell-mediated immune reactions in diabetic rats and their physiological capacity to synthetize antibodies suggests that the sensitivity to an insulin-deprived environment is present only in a definite, although yet undefined, subpopulation of lymphoid cells rather than in the whole lymphoid system.

Animals↗