Biomedical subjects
Publications and source records attributed to C Grillo.
Photon emission in the visible and near ultraviolet range by samples of human tissue removed during surgery has been measured by means of a low noise photomultiplier coupled to a data acquisition system. The results show that among the 25 analyzed samples the 9 from normal tissues had an emission rate of the order of some tens of photons/cm2 min, while most of the 16 tumor tissue samples had a very much higher rate.
Type I corticosteroid receptors were determined in cytosol from hippocampus (HIPPO) and amygdala (AMYG), using [3H]aldosterone (ALDO), [3H]dexamethasone (DEX) or the mineralocorticoid antagonist [3H]ZK 91587 as ligands. Incubations with the first two compounds also contained the pure glucocorticoid RU 28362 to block type II receptors. Binding of the three ligands was comparable in cytosol from HIPPO and it was slightly higher for [3H]DEX in AMYG. However, after heat-induced receptor transformation, binding to DNA-cellulose was observed for [3H]ALDO-receptor complex obtained from HIPPO or AMYG, whereas it was negligible for [3H]ZK 91587. Receptors charged with [3H]DEX or [3H]ALDO showed similar retention on DNA-cellulose columns in the case of the AMYG, while binding to the polynucleotide was higher for [3H]ALDO in the HIPPO. Finally, only [3H]ALDO was taken up to a significant extent in purified cell nuclei prepared from slices of HIPPO and AMYG previously incubated with the three ligands. It is concluded that binding of a natural agonist steroid may be a prerequisite for type I receptor transformation and translocation from the cytoplasm into the nuclear fraction. DEX binding to type I receptors resembles a partial agonist with antagonist properties, whereas antagonists such as ZK 91587 are bound and retained in cytoplasm, without further translocation.
Adrenocortical hormone effects in the central nervous system depend on steroid interaction with intracellular receptors, which belong to a superfamily of ligand-activated transcription factors. Using a combination of biochemical and molecular biology techniques, we have demonstrated: 1. the localization of mineralocorticoid receptors in the brain, with highest density present in hippocampus, lateral septum and some amygdaloid nuclei; 2. the arousal of a mineralocorticoid-specific behavior such as salt appetite, coincident with inhibition of the biosynthesis/activity of (Na+K)ATPase in some amygdaloid and hypothalamic nuclei; 3. the modulation of the biosynthesis/activity of the sodium pump by glucocorticoids, although for these hormones changes are stimulatory, as shown in the spinal cord and brain; 4. the reported steroid effects on the (Na+K)ATPase constitute an important mechanism of control of nervous system function, involving behavior, changes in excitability and neurotropism.
1. We have used in situ hybridization techniques to determine the mRNA for (Na + K)ATPase in 20 brain regions from control rats and rats treated with high doses of deoxycorticosterone (DOC). 2. DOC-treated rats developed a salt appetite following the second hormone administration on alternate days and were used after the fourth DOC administration. 3. DOC treatment did not change the number of silver grains/cell deposited in cells from Ca1, CA2, CA3, and CA4 hippocampal subfields, dentate gyrus, cerebral cortex, medial preoptic area (POA), substantia nigra, and periventricular gray matter. 4. Nonsignificant reductions were detected in lateral POA, medial and lateral septum, caudate-putamen, and three amygdaloid nuclei (cortical, basolateral, and central) from DOC-treated rats. 5. Significant reductions were obtained, after DOC administration, in arcuate and ventromedial hypothalamic nuclei and medial and lateral amygdala. 6. The results suggested that regulation of the beta-subunit mRNA of (Na + K)-ATPase may be related to the central actions of mineralocorticoids in the control of salt intake.
Binding of cyclic adenosine 3',5'-monophosphate (cAMP) and steroid receptors was studied in cytoplasmic and nuclear fractions of pituitaries from castrated rats, in rats subjected to acute (60 min) or short-term (4 days) estradiol (E2) treatment, and in diethylstilbestrol-induced pituitary tumors (DES-T). E2 receptors were primarily in nuclear extracts in all animals that were given estrogens, whereas cytosolic receptors were low to absent. Contrarily, castrated rats showed high quantities of cytoplasmic receptor but little in nuclear sites. The progestin receptor was induced only in 4-day E2-treated rats and in DES-T. cAMP binding was stimulated in cytosol from 4-day E2-treated rats and in DES-T, but a significant reduction in binding was also noted in nuclear extracts from DES-T. Scatchard analysis for the cytosolic cAMP-binding activity demonstrated a two-component system, and the increased cAMP binding obtained in DES-T seemed to be caused by an increase in the low-affinity, high-capacity binder [regulatory type II (RII) subunit of protein kinase]. Suggestion of the preferential estrogenic induction of RII was also obtained by DEAE-cellulose chromatography, which provided separation of RI and RII subunits. The results suggest that sustained estrogenization leads to induction of cytosolic cAMP-binding protein and increased levels of nuclear E2 receptor. In DES-T, this effect resulted in an inverse subcellular distribution of both binding proteins, which may be related to abnormal growth of the pituitary, as has been postulated for hormone-dependent mammary tumors.
We have studied the binding of the synthetic antimineralocorticoid [3H]ZK 91587 to soluble receptors in brain of adrenalectomized rats. It was observed that [3H]ZK 91587 labeled a single receptor class with high affinity (Kd 1.3 nM) and low capacity (51.1 fmol/mg prot.) in cytosol of hippocampus (HIPPO). The ligand was efficiently displaced in vitro from the receptor by aldosterone (IC50 2.0 nM) and corticosterone (2.3), while dexamethasone showed less potency (IC50 5.1 nM) and the pure antiglucocorticoid RU 28362 competed weakly (161 nM). Furthermore, there was a widespread distribution of binding sites all over the brain for this compound, but with CA1 and CA3 regions of HIPPO, some amygdaloid nuclei and lateral septum containing most of the binding sites, as revealed by binding assays employing 16 different microdissected brain regions. Finally, the receptor labeled with [3H]ZK 91587 was readily displaced by administration of aldosterone in vivo in physiological amounts, from 5 whole brain regions examined, but preferentially from preoptic area, amygdala and HIPPO. It is concluded that [3H]ZK 91587 is a useful ligand for further studies on putative mineralocorticoid responsive cells in brain, due to its high affinity, stability and lack of cross reactivity with glucocorticoid receptors. Its brain distribution is similar to that previously obtained using [3H]aldosterone in the presence of RU 28362 to block ligand binding to the glucocorticoid receptor.
The induction of reciprocal translocations in mouse germ cells by combined treatments with chemicals and ionizing radiations has been studied. Male mice were intraperitoneally injected with doses of 5 or 10 mg/kg of adriamycin (ADR) and irradiated with doses of 5 or 9 Gy of gamma-rays 24 h later. Three types of response were found after analyzing diakinesis-metaphase I multivalent configurations: potentiation, with the dose of 5 mg/kg of ADR plus 9 Gy; subadditivity, with the dose of 5 mg/kg of ADR plus 5 Gy; and additivity, with the dose of 10 mg/kg of ADR plus 5 or 9 Gy. According to these results, the subadditive effect observed with the lower dose of ADR plus 5 Gy cannot be explained under the assumption that depletion of any kind of spermatogonia is sufficient for modifying the chromosomal response of stem cells to ionizing radiations. The role of DNA repair mechanisms modulating the response of spermatogonial cells to combined treatments is discussed under the assumption that some repair mechanisms can be triggered by treatment with a low dose of a chemical and these repair mechanisms can reduce cell mortality. Consequently, a higher frequency of more radioresistant cells can survive.
Mineralocorticoids (MC) have a dual effect on salt intake: in adrenalectomized rats, they reduce previously elevated salt intake; and in intact rats a high MC dose increases salt intake. We have studied the activity of (Na+K)-ATPase and [3H]ouabain binding in rats treated with deoxycorticosterone (DOC) in doses that elicited a salt appetite. Brains were removed from control and treated animals, and 20 different areas were punched out from brain slices cut every 300 microns. DOC treatment significantly reduced (Na+K)-ATPase activity in the lateral hypothalamic area, anterior amygdaloid and lateral amygdaloid nuclei, while increasing it in the periventricular gray matter; changes in other regions were not significant. Binding of [3H]ouabain was not modified by DOC treatment. In parallel experiments, we determined MC receptors in adrenalectomized rats. Binding of [3H]aldosterone was preferentially found in hippocampus, followed by lateral septum, anterior, posterior and lateral amygdaloid areas, with lower levels in other regions. However, there was no correlation between [3H]aldosterone binding and (Na+K)-ATPase activity in brain punches from either control or DOC-treated rats. Further experiments are needed to ascertain if (Na+K)-ATPase changes in discrete areas of the brain containing moderate levels of mineralocorticoid receptors, are related to the behavioral effects of DOC.
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42 necrokidney transplants, performed in Renal Unit of "Niguarda - Ca' Granda" Hospital in Milan, since 1972, have been examined. Hystocompatibility score and previous transfusions and/or pregnancies apparently did not correlate with three months transplants survival. Our patients have been separated into two groups according to treatment with or without ALG: the group treated with ALG showed a better percentage survival of the kidney at three months a lower incidence of rejection episodes during the same period. The usefulness of ALG treatment is reaffirmed; we consider that a better prognosis at three months probably means a more favorable clinical course.
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Explore the source record for details and available documents.
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