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Biomedical subjects

C Biondi

Publications and source records attributed to C Biondi.

At least 91 records · Page 5Linked to original sources
PubMed1983

Heterosynaptic facilitation and behavioral sensitization are inhibited by lowering endogenous cAMP in Aplysia.

An adenylate cyclase inhibitor, RMI 12330A, is able to depress cAMP synthesis stimulated by serotonin in the abdominal ganglion of Aplysia depilans and punctata. This substance reversibly blocked the heterosynaptic facilitation, induced by activation of serotonergic pathways, of the EPSP recorded from L7 motoneuron in abdominal ganglion after electrical stimulation of the siphon nerve. RMI 12330A, injected into whole unrestrained animals, inhibited the short-term dishabituation of the siphon withdrawal reflex. These findings demonstrate that the increase of endogenous cAMP in the sensory neurons mediating the gill and siphon withdrawal reflex is an essential step in the mechanism of potentiation of the transmitter output underlying heterosynaptic facilitation and short-term behavioral sensitization.

Adenylyl Cyclase Inhibitors↗
PubMed1983

alpha-L-fucosidase activity in endometrial, cervical and ovarian cancer.

alpha-L-fucosidase activity assayed on endometrial, cervical and ovarian tissue in benign and malignant conditions has been found to be increased in cancer tissue. Knowing that alpha-L-fucose plays a fundamental role in the process of inhibition of macrophages migration, increased activity of fucosidase in tumors can be interpreted as a possible mechanism by which cancer cells directly subvert the process of macrophages activation thus facilitating xenoplastic growth.

Adenocarcinoma↗
PubMed1982

cAMP-dependent and cAMP-independent modulation of synaptic transmission in guinea-pig superior cervical ganglion.

RMI 12330A dose-dependently inhibits cAMP accumulation induced by PGE2 in guinea-pig superior cervical ganglion (SCG). Norepinephrine (NE) is unable to modify cAMP concentration in the same preparation. On the other hand, both PGE2 and NE block the firing discharge of guinea-pig SCG neurons elicited by electrical stimulation (1 Hz) of the cervical sympathetic trunk. The effect of PGE2, but not that of NE, is prevented by RMI 12330A, suggesting that NE and PGE2 act through different pathways

Acetylcholine↗
PubMed1982

Role of serotonin and cyclic AMP on facilitation of the fast conducting system activity in the leech Hirudo medicinalis.

In the nervous system of the leech Hirudo medicinalis it has been possible to study short-term plastic changes. Depression and facilitation have been demonstrated in the fast conducting system (FCS) activity; this pathway consists of a chain of electrically linked neurons present in each ganglion. In semi-intact animals or in preparation of nerve cord and segments of body wall, both electrical stimulation of peripheral roots and tactile stimulation of the skin induced, after repetitive stimulation (0.1/s) a prolonged decrement of FCS response. Strong nociceptive stimulation applied onto the head or the body wall produced a sustained facilitation of the waned response. The same potentiation has been observed by perfusing the isolated ganglion with serotonin (5 x 10(-5) M). Such a potentiation is abolished by preincubation with methysergide, an antagonist of serotonin, and with imidazole, a cAMP-phosphodiesterase activator. Such an effect is mimicked by an analog of cAMP, db-cAMP. Simultaneous recordings of both T neurons (intracellularly) and FCS firing discharge showed that, during FCS response decrement, the T cell activity remained unchanged and no modification of conductance occurred, excluding therefore a detectable involvement of sensory neurons in the depression. These results suggest that short-term plastic changes of the FCS of the leech are due to a prolonged potentiation of synaptic transmission as a result of serotonin-mediated increase in cAMP.

Animals↗
PubMed1982

Evidence for increased release of prostaglandins of E-type in response to orthodromic stimulation in the guinea-pig superior cervical ganglion.

Prostaglandins of the E type (PGEs) stimulate cyclic adenosine 3',5'-monophosphate (cAMP) biosynthesis both in isolated preparations of rat, guinea-pig and rabbit superior cervical ganglia (SCG) and in calf SCG slices. Electrical stimulation of preganglionic nerve fibers of the guinea-pig SCG remarkably increased PGE release and cAMP biosynthesis. These effects were blocked by reducing the Ca2+ to Mg2+ ratio in the incubation medium. Atropine (1 microM) and phentolamine (10 microM) inhibited PGE biosynthesis and significantly reduced cAMP levels.

Animals↗
PubMed1981

[Preliminary studies on the characterization of adenylate cyclase from segmental ganglia of the leech Hirudo medicinalis].

Adenylate cyclase activity has been measured in segmental ganglia of the leech Hirudo m. Basal enzymatic activity was stimulated in a dose dependent fashion by serotonin. GTP is required in order to evoke maximal stimulation. The effect was blocked by methysergide, an antagonist of serotonin at receptor level. The stimulation of the enzyme was prevented by alpha beta-methy-len-ATP. In addition RMI 12330A inhibited basal as well as serotonin-stimulated adenylate cyclase activity presumably by acting at the catalytic subunit level.

Adenosine Triphosphate↗
PubMed1980

[Echotomography of cold thyroid nodules (author's transl)].

Using echotomography (both A-mode and B-mode) in more than 150 cases of cold thyroid nodules, with 113 cases histologically controlled, the authors valuate the accuracy of this investigation in the diagnosis of nature, exceeding the old distinction in solid, cystic, or mixed nodule.

Biopsy↗