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Biomedical subjects

V Locatelli

Publications and source records attributed to V Locatelli.

At least 127 records · Page 7Linked to original sources
PubMed1982

GABAergic control of anterior pituitary hormone secretion.

Anatomical and biochemical studies have identified a hypothalamic tubero-infundibular GABAergic system, which plays a functional role on anterior pituitary hormone secretion. Experimental and clinical evidence support the presence of a dual component in the action of GABA; one mediated via the central nervous system and the other exerted directly at the anterior pituitary level. The two sites of action may be responsible for the excitatory and inhibitory effects of GABA on pituitary hormone and especially prolactin secretion. The future characterization of this system will provide a better understanding of the involvement of GABA in the physiology of anterior pituitary hormone secretion and will contribute to the development of new pharmacological agents for the therapy of neuroendocrine disorders.

Adrenocorticotropic Hormone↗
PubMed1982

ACTH1-24 counteracts the prolactin-releasing effect of an opioid.

The administration of the synthetic and stable opioid peptide[D-Ala2,MePhe4,Met(O)5o1]enkephalin (FK 33-824) at the dose of 0.2 mg/kg i.v. induced a rise in plasma levels of prolactin in the rat, an effect which was prevented by 1 mg/kg i.v. of the opiate antagonist naloxone. A simultaneous i.v. injection of 20 microgram/kg i.v. of ACTH1-24 significantly reduced the prolactin releasing effect of FK 33-824, therefore giving further evidence of an in vivo interaction between ACTH-related peptides and opioid peptides.

Adrenocorticotropic Hormone↗
PubMed1982

Neuroanatomical methods for the quantitative evaluation of coexistence of transmitters in nerve cells. Analysis of the ACTH- and beta-endorphin immunoreactive nerve cell bodies of the mediobasal hypothalamus of the rat.

A new statistical approach has been introduced to study in a quantitative way the coexistence of two neuromodulators in nerve cell bodies. The method has been exemplified on the ACTH-like and beta-endorphin-like immunoreactive nerve cell bodies of the mediobasal hypothalamus demonstrated by means of indirect immunofluorescence methodology. The method is based on the analysis of 3 adjacent sections which, in a random way, are stained with antiserum against neuromodulator 1, against neuromodulator 2 and with antisera against both neuromodulator 1 and neuromodulator 2. It could be shown that some neurons of the mediobasal hypothalamus do not contain at a detectable level both ACTH- and beta-endorphin-like immunoreactivity. The present method also involves an analysis of the two nerve cell groups by means of a morphometric procedure to collect additional information on the extent of coexistence. Thus, by this approach the gravity centers of the two cell groups can be calculated. The distances between the two gravity centers of the ACTH and beta-endorphin positive cell groups were significantly different at certain levels. The present method offers unique possibilities in increasing our understanding of the functional significance of coexistence of neuromodulators in one and the same nerve cell body since it makes possible a quantitative evaluation of coexistence. The usefulness of the present method is illustrated by the findings of a possible differential synthesis of ACTH- and beta-endorphin-like material in certain cell bodies of the mediobasal hypothalamus.

Adrenocorticotropic Hormone↗
PubMed1982

An unusual case of congenital double coronary arteriovenous fistula.

A double coronary arteriovenous fistula (CAVF) was observed in a ten-year-old girl. A large, tortuous, and elongated right coronary artery, communicating with the right ventricle, was detected by two-dimensional echocardiography and confirmed at angiography. To our knowledge, no echocardiographic recognition of the origin and termination of a CAVF has been reported previously. Moreover, another fistula, connecting the left anterior descending coronary artery with the main pulmonary artery was also detected by selective left coronary arteriography. The anatomy of double CAVF was confirmed on surgery. A right CAVF draining into the right ventricle and a left CAVF draining into the main pulmonary artery seemed to be a very unusual combination.

Arteriovenous Malformations↗
PubMed1981

Contrast echocardiographic features of pulmonary hypertension and regurgitation.

Linear contrast echo configuration on the pulmonary valve M-mode echogram was assessed in 28 patients with pulmonary hypertension, in 10 with pulmonary regurgitation, and in 10 normal subjects. Contrast echo parallel lines filling the total systolic phase of the pulmonary valve were recorded in normal subjects. Contrast echo lines stopping in early systole around the pulmonary valve mid-systolic notch were seen in all the patients with pulmonary hypertension in relation to changes with the pulmonary flow. Contrast echo lines reversing the early diastole and crossing the pulmonary valve echogram during diastole were detected in all the patients with pulmonary regurgitation, consistent with the reversed flow across the valve. The use of contrast echocardiography to diagnose both pulmonary hypertension and regurgitation may provide further useful information, particularly when the orientation and time of appearance of the contrast echo lines are related to the systolic and/or diastolic phases of the pulmonary valve M-mode echogram.

Diastole↗
PubMed1981

Contrast echocardiography of the inferior vena cava.

M-mode and two-dimensional subcostal contrast echocardiography were used in 67 patients and 10 normal subjects to evaluate the contrast echo effect on the inferior vena cava echogram in relation to the cardiac cycle and respiratory events. No contrast echoes were recorded in the inferior vena cava in normals during normal breathing. Contrast echoes were recorded entering the inferior vena cava in systole in 20 patients with tricuspid regurgitation and in pre-systole in patients with atrial septal defect and left-to-right shunt and in some of the patients with elevated right atrial and ventricular end-diastolic pressure. Forced inspiration increased the contrast echo effect and determined the penetration of microbubbles into the inferior vena cava. This latter feature occurred in all the patients and only in 1 normal subject. The entry of the contrast echoes into the inferior vena cava was attributed to the high right atrial ventricular end-diastolic pressure and to the reversed flow, from the right ventricle to the right atrium and inferior vena cava in tricuspid regurgitation and from the left atrium to the inferior vena cava in atrial septal defect. The contrast echocardiographic diagnosis of tricuspid regurgitation appeared to be most reliable. New encouraging results were obtained by this technique in diagnosing atrial septal defect and left-to-right shunt. The first appearance of the contrast, the time of appearance in relation to the cardiac cycle and the direction of the to and fro motion of contrast echoes were the most important factors considered for a correct diagnosis.

Cardiomegaly↗
PubMed1980

Renin-like immunocytochemical activity in the rat and mouse brain.

Renin-like immunoreactivity could be demonstrated in the nuclei paraventricularis, periventricularis and supraopticus of the hypothalamus and in the cerebellar cortex of rats and mice, with both the peroxidase-antiperoxidase (PAP) and fluorescence techniques. The findings are consistent with the assumption of an endogenous angiotensin-forming system in the brain.

Animals↗