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G Ronsisvalle

Publications and source records attributed to G Ronsisvalle.

At least 37 records · Page 2Linked to original sources
PubMed1993

Non-peptide ligands for opioid receptors. Design of kappa-specific agonists.

A series of phenyl carboxyl esters 5a-d derived from N-(cyclopropylmethyl)normetazocine was synthesized and evaluated for its selectivity at mu, kappa, and delta opioid receptors. Compound 5a, although 43 times less potent than the reference compound U50488, was specific for kappa receptors, having no detectable affinity for either mu or delta receptors. Greater binding affinity was seen with the diastereoisomer having the 1'R,2'S stereochemistry in the cyclopropyl ring of the nitrogen substituent, which was only 12 times less active than U50488. Antinociceptive activity in the mouse tail flick was only slightly lower than that of U50488 (ED50 = 7.66 vs 4.52 mg/kg). Naloxone fully prevented antinociception induced by (1'R,2'S)-5a at the doses of 2.0 mg/kg. Compound (1'R,2'S)-5a is one of the most kappa-selective non-peptide compounds reported to date. The implications of these results in terms of requirements for kappa ligands are discussed.

Animals↗
PubMed1992

Comparison of ST segment changes on standard and Holter electrocardiogram during exercise testing.

In order to compare the ST segment changes recorded simultaneously on Holter (Del Mar Avionics 445B recorder and DCG VII Scanner) and standard electrocardiogram, 22 patients with chest discomfort and normal resting ECG were evaluated during exercise testing. The conventional ECG was recorded using chest lead V5 and a modified lead II. The Holter recording was done using the bipolar chest lead CM5 and the same modified lead II. Bifurcating electrodes permitted simultaneous recording of electrocardiogram on both systems from the same electrode sites. Seven of the 22 patients had a positive test and 15 had a negative test by both systems. In 7 positive cases the amplitude of ST segment depression was compared. The Holter lead CM5 showed higher amplitude of ST segment depressions in 6 cases compared to the conventional lead V5: 3 cases by 0.5 mm; 2 cases by 1 mm and 1 case by 2.5 mm. In 1 case it was identical. The amplitude of ST segment depression in lead CM5 ranged from 1 to 3.5 mm (mean 2.2 +/- 0.6 mm) and in lead V5 from 1 to 2.5 mm (mean 1.5 +/- 0.6 mm). Thus the amplitude of ST depression was higher in lead CM5 by a mean of 0.7 mm compared to the lead V5. ST segment depression was present only in 6 cases in the modified lead II. ST segment depressions were reproduced faithfully in 3 patients and within the variation of 0.5 mm in other 3 cases by the Holter system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Specific features of left ventricular hypertrophy in hypertensive obese women. An echocardiographic study.

The echocardiographic features of the left ventricle of 37 obese women (body mass index above 30) and 37 lean controls, matched for sex, age, height and blood pressure levels, were studied. Twenty-six patients in each group were hypertensive. The normotensive obese patients did not show any differences, comparing to the normotensive controls; on the contrary, the hypertensive obese patients had higher left ventricular mass (LVM), stroke volume and cardiac output (CO), and lower total peripheral resistance (TPR) than the hypertensive controls. A positive correlation was found between the LVM and the CO (r = 0.57, P less than 0.01) in hypertensive obese patients, and between the relative wall thickenss (h/r, that is the ratio between the left ventricular wall thickness and the left ventricular radius) and TPR (r = 0.64, P less than 0.01) in the hypertensive controls. It is concluded that obesity per se does not determine left ventricular hypertrophy in women; however, when obesity is associated with arterial hypertension, a distinct pattern of hypertrophy, characterized by high CO and low TPR, develops.

Adult↗
PubMed1989

Chemical and pharmacological investigations on 2H-pyridazino[4,5-b] [1,4]benzothiazin-1(10H)-one derivatives.

The methylation of 2H-pyridazino [4,5-b][1,4]benzothiazin-1(10H)-one-5,5-dioxide 2 and the oxidation of 2-methyl-2H-pyridazino[4,5-b][1,4]benzothiazin-1(10H)-one 3 produced the same compound 4. On the contrary, in the 2-dialkylaminoalkylic series, the dialkylamino-alkylation and the oxidation reactions, carried out on compounds 2 and 8 respectively, afforded derivatives 7 and 9. In addition, the behaviour to the oxidation of the corresponding 10-methyl and 10-dialkylaminoalkyl analogues is also described. The synthesized compounds were tested for their analgesic, antiexudative and anti-inflammatory activities. The pharmacological results showed that in general dialkylaminoalkyl derivatives are more active than methyl derivatives. In particular, compounds 7 b, 9 b and 11 c exhibited an analgesic activity comparable to that of phenylbutazone; moreover 10-substituted compounds 11 a, 11 b and 11 c, screened p.o. as anti-inflammatory agents in rats, resulted equipotent to phenylbutazone and more active than 2-substituted isomers. These activities are coupled with a high LD50 and a very low ulcerogenic potential.

Analgesics↗
PubMed1989

Synthesis of substituted pyrimidines, pyrazole[3,4-d]pyrimidines and imidazo[4,5-d]pyrimidines and evaluation of their antifungal activity.

Some pyrimidines, pyrazolo[3,4-d]pyrimidines and imidazo[4,5-d]pyrimidines bearing the 5-nitro- and 5-aminothienyl-2-sulfide functionalities on the pyrimidine nucleus were synthesized and evaluated for their antifungal activity against several strains of yeasts and dermatophytes. 4-Amino-2-pyrimidinyl-5'-nitro-2'-thienylsulfide (Va) resulted active against both yeasts and dermatophytes (about 30 fold less potent than Miconazole). Compds. (II b), (V b) and (VIII b) showed only a slight activity against dermatophytes, while the other compounds were inactive.

Acetylation↗
PubMed1988

Acromegalic cardiomyopathy. An echocardiographic study.

Eighteen acromegalic patients (A) and 18 controls without clinical evidence of cardiac involvement and/or endocrine disease (C), matched for sex, age, body surface area, and blood pressure (BP), were investigated by M-mode (2-D derived) echocardiography, to clarify the prevalence and the possible determinants of left ventricular hypertrophy (LVH). Seven patients in each group were hypertensive (BP greater than 160/95 mmHg). Left ventricular mass (LVM) was 183.1 +/- 60.0 g/m2 in A and 130 +/- 25.9 g/m2 in C. A LVM above 140 g/m2 (that is the upper normal range in our laboratory) was found in 15/18 A and 2/18 C. The LVH was concentric (h/r greater than 0.45) in 12/15 A and 1/2 C. Systolic function indexes (% FS, end-systolic stress/end-systolic volume), cardiac index and total peripheral resistance index (as determined by echo) were within the normal range and similar in both groups. No correlation was found between LVM and BP, LVM and GH plasma levels, LVM and Sm-C levels. A significant correlation was found between LVM and duration of the disease (r 0.44; p less than 0.05). Our data confirm that LVH is an early and frequent finding in acromegaly. Its prevalence is not entirely accounted for by such factors as body size, BP or increased cardiac output. Metabolic factors may play a major role, and a long lasting exposition to increased GH levels seems the most relevant determinant of LVH.

Acromegaly↗
PubMed1988

Studies on isoquinoline derivatives. IV. Synthesis and evaluation of the antimicrobial and antifungal activities of N2-arylidene-substituted 3-carbazoyl-isoquinolines.

2,4-Dimethyl-1-oxo-1,2-dihydro-3-carbazoyl-isoquinoline (II), 1-chloro-, 1-methoxy-3-carbazoyl-4-methylisoquinoline (VI, X) and a series of their hydrazonic derivatives have been synthesized and tested in vitro for antibacterial and antifungal activities. 1-(1-Chloro-4-methyl-3-isoquinolinoyl)-2-(5-nitro-2-furfurylide ne) hydrazine (VII h) proved to be the most effective in the series (MIC 0.78 micrograms/ml) and was more potent than furazolidone against several strains of S.aureus; the same compound also showed a moderate antifungal activity.

Anti-Bacterial Agents↗
PubMed1987

Hemispheric TIA and amaurosis fugax: what is their relation to stenotic lesions of internal carotid artery?

We evaluated the correlation of clinical and echo-Doppler findings from the internal carotid artery (ICA) in 17 patients with amaurosis fugax (AF) and in 68 patients with hemispheric TIA (H-TIA). In the study population as a whole, moderate stenoses (20%-49% diameter reduction) were the most prevalent finding in the symptomatic ICA, being detectable in 51.6% of cases. Total occlusions were found in an unexpectedly high percentage (7.5%). Asymptomatic ICAs, that were contralateral to the symptoms, showed the same degree of atherosclerotic involvement as the symptomatic ICAs. When we compared AF with H-TIA, we found a significantly higher prevalence of severe hemodynamically significant stenoses in the former (52.6% vs. 18.8%, chi-square test 10.85, P less than 0.05). Thus, we conclude that in the vast majority of patients with transient neurological symptoms a bilateral ICA involvement is to be expected. The side on which the symptoms occur does not indicate which ICA is more severely stenotic except in AF, where a severe involvement of the ipsilateral ICA is most likely.

Aged↗
PubMed1987

Prevalence of atherosclerotic involvement of the internal carotid artery in hypertensive patients.

The prevalence of atherosclerotic involvement of the internal carotid arteries, as diagnosed through an echo-Doppler imaging system with pulsed Doppler spectral analysis was evaluated in 49 hypertensives who had a negative history for neurological symptoms and 49 matched controls. The prevalence was 24.5% in the hypertensive group and 10.2% in the controls with a statistically significant difference (chi-square = 6.07, P less than 0.01). Two hypertensives had severe stenosis (above 50% diameter reduction) and 7 had potentially embolic lesions (irregular surface, inhomogeneous appearance). No one of the matched controls was as severely involved. We conclude that arterial hypertension can account for enhanced prevalence of carotid artery disease in asymptomatic patients.

Adult↗
PubMed1987

Prospective evaluation of combined carotid and coronary surgery.

In order to evaluate the effectiveness of combined carotid and coronary surgery in reducing the incidence of neurological disturbances after coronary artery bypass grafting (CABG), 144 consecutive candidates for CABG (group I) were screened for carotid disease noninvasively with Doppler ultrasonography (duplex). Twenty-six (18%) were considered at risk for stroke because of a severe (above 50% diameter reduction) stenosis; 20 (4 symptomatic and 16 asymptomatic) underwent combined surgery. Forty-seven other patients (group II) underwent CABG surgery without previous Doppler investigation. Only three patients (1.5% of the survivors) developed transient neurological disturbances after surgery; two who had normal internal carotid arteries belonged to group I, and one to group II. None of the six patients at risk for stroke who underwent only CABG developed neurological symptoms. The incidence of intra- and postoperative cardiac complications of the group who had CABG only compared to that of the group with combined surgery. We conclude that, although safe, combined surgery is not to be performed systematically on candidates for CABG with a significant internal carotid artery stenosis.

Brain Ischemia↗
PubMed1987

Hybrid bivalent ligands with opiate and enkephalin pharmacophores.

Bivalent ligands consisting of oxymorphamine and [D-Glu2]enkephalin pharmacophores linked through a spacer attached to the 6-amino group of the former and D-Glu of the latter were synthesized in an effort to investigate the possible coexistence of mu and delta recognition sites in the same opioid receptor complex. Of the two bivalent ligands (1,2) synthesized, only 1 had substantially greater antinociceptive potency in mice than its monovalent analogues (1a, 1b). Testing of 1, 1a, and 1b in the guinea pig ileum preparation (GPI) revealed a potency profile similar to that found in vivo, whereas no correlation was observed in the mouse vas deferens (MVD). Binding data indicated the same rank-order affinities at delta receptors as the opioid activities in the GPI and in mice. However, mu binding exhibited no relationship with activity. These results are consistent with the simultaneous occupation of mu and delta by a single bivalent ligand 1, but they are also in harmony with the interaction of 1 with an opioid receptor and an accessory binding site.

Analgesics↗
PubMed1987

Effect of endurance training on Q-T interval and cardiac electrical stability in boys aged 10 to 14. Ventricular arrhythmias in trained boys.

In 30 highly trained boys aged 10-14 the prevalence of ventricular ectopic beats and Q-T interval duration were studied. In trained boys ECG Holter monitoring showed a higher even though not significantly different prevalence of ventricular arrhythmias than in 30 age-matched untrained controls. Ventricular ectopy was on the contrary lower than in a group of 30 adult athletes. Q-T corrected (Q-Tc) interval in the trained boys was longer than in the sedentary controls (p less than 0.001), while it was as long as in the adult athletes. No correlation was found between the degree of severity of ventricular ectopic beats and Q-Tc interval duration, heart rate or echocardiographic dimensional and functional findings. The clinical and prognostic importance of complex ventricular arrhythmias detected in healthy athletes remains to be elucidated.

Adolescent↗