Biomedical subjects

L Calza

Publications and source records attributed to L Calza.

21 records · Page 2Linked to original sources

PubMed1981

Abnormal control of growth hormone secretion by opiate systems in acromegalic patients: a study with naloxone and 2-Br-alpha-ergocryptine (CB 154).

The present study was undertaken with the aim of exploring the role that opiate systems may have in neuroendocrine control in acromegaly. The effects of naloxone (0.4 mg, i.m.), of 2-Br-alpha-ergocryptine (CB154, 2.5 mg, p.o.) and of the interaction between CB154 and naloxone on growth hormone (GH) and prolactin (PRL) secretion were studied in 11 acromegalic patients. CB154 reduced both GH and PRL serum levels, naloxone only GH serum levels. The latter effect deserves further study aimed at a possible new therapeutic approach to GH hypersecretion observed in acromegaly. Naloxone also interfered with the lowering effects of CB154 and GH and PRL serum levels, pointing to the existence of an interaction between dopaminergic and opiate control of GH and PRL secretion in acromegaly.

Acromegaly↗

PubMedDate not supplied

Morphometric characterization of transmitter-identified nerve cell groups: analysis of mesencephalic 5-HT nerve cell bodies.

Morphometric techniques have been used to introduce criteria to objectively define transmitter-identified nerve cell groups and subpopulations of nerve cells within such groups. The present method is exemplified on two coronal sections of the midbrain, in which 5-HT immunoreactive nerve cell bodies have been visualized. The reliability of the method is shown by the fact that it makes it possible not only to recognize groups B7, B8 and B9 of Dahlström and Fuxe [5] but also to assess the existence of two subpopulations within group B7 as previously suggested by Fuxe and Jonsson [11] based on subjective evaluations. Furthermore, the suggestion could be made that a small assembly of 5-HT nerve cell bodies in the dorsal part of the mesencephalic tegmentum may form a new 5-HT cell group. Hence, the present method offers the advantage of assessing the existence of transmitter-identified nerve cell groups on the basis of objective criteria and to describe them in a quantitative fashion. Therefore, it allows quantitation of morphological changes occurring in transmitter-identified neurons under different experimental and pathological conditions.

Animals↗

PubMedDate not supplied

A morphometric analysis of transmitter identified dendrites and nerve terminals.

The present method is exemplified on coronal sections of the medulla oblongata containing phenylethanolamine-N-methyltransferase (PNMT) immunoreactive nerve cell bodies and their processes and on coronal sections of the pons containing the locus coeruleus, where PNMT immunoreactive nerve terminals have been demonstrated together with the dopamine-beta-hydroxylase immunoreactive nerve cell bodies. Morphometric analysis of the processes (both length and branches) and of the nerve terminals involve as a first step the division of the area under study into squares 100 microns wide, which are superimposed on a Cartesian plane. The uniformity of the density distribution of the nerve terminals and the processes (branches or length) can be analyzed by Lorenz curves, which in a quantitative way can measure the degree of unevenness and thus represent a measure of concentration. A concentration index can therefore be calculated. By the use of the densitometric approach it also becomes possible to study the density distribution of the nerve terminals with the highest antigen contents. The present method will make it possible to quantitate morphological changes occurring in processes and nerve terminals of transmitter-identified neurons.

Animals↗