PubMed Health⌕ Search

Biomedical subjects

G Ronsisvalle

Publications and source records attributed to G Ronsisvalle.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Prevalence, characteristics and clinical correlates of left ventricular hypertrophy in stable hypertension. Echocardiographic study].

251 in stable hypertensives were studied with M-Mode and two-dimensional echocardiography, in order to evaluate the prevalence of left ventricular hypertrophy (LVH), its patterns and clinical correlates. 54 subjects (21%) had been treated previously with antihypertensive drugs while the remaining 197 (79%) had not. A normal left ventricle was found in 69 subjects (27.1%; group A); a concentric LVH (h/r greater than or equal to 0.45) was found in 99 (39.4%; group B), while an eccentric LVH (left ventricular myocardial mass index greater than 140 g/m2, h/r less than 0.45) in 83 (43.1%; group C). An asymmetric LVH (septum to posterior wall thickness ratio greater than or equal to 1.3) was found in 33 subjects (3 did not fulfill the criteria for LVH, 21 had a concentric, and 10 an eccentric LVH). Mean age was significantly higher in group B as compared to groups A and C. The body mass index was comparable in all groups. Mean systolic blood pressure was significantly higher in groups B and C as compared to A. The duration and the severity of hypertension did not differ among the three groups. W.H.O. stage III was absent in group A, but no differences were found between group B and C as for W.H.O. stage distribution. We conclude that such factors as BMI, duration and severity of hypertension poorly correlate with the occurrence of LVH and its patterns. The fact that group B hypertensives were older than the others on average is against the hypothesis that eccentric hypertrophy follows the concentric pattern. Whether these two patterns represent separate entities in relation to different hemodynamic profiles deserves further investigation.

Adult↗
PubMed1986

Synthesis and opioid antagonist potencies of naltrexamine bivalent ligands with conformationally restricted spacers.

Bivalent ligands 1-4 with naltrexamine pharmacophores and spacers of different lengths containing a fumaryl moiety were synthesized and evaluated for mu and kappa opioid antagonist activity on the electrically stimulated guinea pig ileal longitudinal muscle (GPI). The fumaryl moiety was incorporated into the spacer in order to determine the effect of conformational restriction of the spacer on the relationship between spacer length and opioid antagonist potency. While it was found that the fumaryl and succinyl series (11) possessed a very similar structure-potency profile with respect to antagonism at mu opioid receptors, the interaction of these two series at kappa receptors differed substantially from one another. This difference was manifested by the longer spacer requirement for peak kappa antagonist potency in the fumaryl relative to the succinyl series. It is concluded that the conformational restriction imposed by the fumaryl group in a short spacer (n = 0) prevents effective interaction of both pharmacophores with vicinal recognition sites of the kappa receptor system; as the spacer is lengthened (n = 2) and becomes more flexible, the simultaneous occupation of vicinal recognition sites occurs with greater facility.

Animals↗
PubMed1986

Opioid agonist and antagonist bivalent ligands. The relationship between spacer length and selectivity at multiple opioid receptors.

Bivalent ligands containing the oxymorphamine or naltrexamine pharmacophores connected to spacers of varying length were synthesized and evaluated for their selectivity at mu, kappa, and delta opioid receptors. The oxymorphamine bivalent ligands (1-8) behaved as mu agonists on the electrically stimulated guinea pig ileum longitudinal muscle preparation (GPI). The spacer that conferred peak agonist activity in these series contains a total of four glycyl units (n = 2). Binding studies with guinea pig brain membranes showed a qualitatively similar profile at mu receptors as a function of spacer length. Also, delta receptor selectivity increased as the spacer was lengthened. The naltrexamine bivalent ligands (9-13) effectively antagonized the mu receptor agonist morphine in the GPI at the same optimal spacer length (n = 2) as in the agonist series. However, the peak antagonism of ethylketazocine, a kappa receptor agonist, occurred with the bivalent ligand 9 containing the shortest spacer (n = 0), and it was found that 9 is the most selective kappa antagonist in the series. While receptor binding roughly parallels that of kappa antagonist activity in the GPI, no correlation between binding and antagonist activity was observed at mu opioid receptors. The possible significance of these results is discussed.

Animals↗
PubMed1986

Echocardiographic evaluation of the dimensions and systolic properties of the left ventricle in freshman athletes during physical training.

The purpose of the study was to evaluate the early anatomic and functional changes of the left ventricles in junior freshman non-professional athletes just beginning specific regular training programs for 6 different types of sport. Forty-nine males (mean age 20 +/- 6 years) and 9 sedentary controls were studied by means of sequential M-mode echocardiograms, before and after a 10 to 12 week training period: 13 athletes started bicycle-riding (aerobic category), 6 sprint (anaerobic category), 6 weight-lifting (strength category), 13 soccer (mixed category), 11 rifle-shooting (manual dexterity category). Resting heart rate, blood pressure, left ventricular diameter (LVID), left ventricular posterior wall and interventricular septum thickness (LVPWT, IVST), left ventricular mass (LVMI), relative wall thickness (h/r ratio) and fractional shortening (FS%) of the LVID, cardiac index (CI) and stroke volume (SV) were comparable in all groups initially. After the training period, the cyclists, the sprinters and the soccer-players showed an increased LVID, LVMI and FS%. The cyclists and the soccer players also showed a decreased h/r ratio. The weight-lifters showed a slight increase of their LVMI, with an increased h/r ratio. We have, thus, documented that even after a relatively short non-strenuous training period, specific anatomical and functional changes occurred in the hearts of young athletes practising sports for recreational purposes, according to the type of sport.

Adolescent↗
PubMed1986

The echo-Doppler (duplex) system for the detection of vertebral artery occlusive disease: comparison with angiography.

The reliability of the echo-Doppler (duplex) system for the visualization of the vertebral arteries was evaluated in 304 patients, in which 588 vertebral arteries had been investigated. Of these, 545 (92.69 per cent) arteries, either normal or diseased, were successfully visualized. However, the origin of the vertebral artery from the subclavian artery was localized in only 354 vessels (60 per cent of those visualized). Angiography was available for comparison in 33 arteries. The overall accuracy and the sensitivity of the duplex were 63.64 per cent and 38.46 per cent, respectively; they attained 86.67 per cent and 83.33 per cent in the vertebral arteries visualized from their origin, (a site early and most commonly involved by the atherosclerotic process). As the vertebral arteries can be visualized with a 92 per cent success rate, their examination should become a routine part of the duplex cerebrovascular study. In order to accurately detect diseased vertebral arteries, their origin from the subclavian artery should be localized.

Aged↗
PubMed1986

[Prevalence of atherosclerotic lesions of the carotid bifurcation found with echo-doppler (duplex) technic in patient candidates for aortocoronary bypass].

The association of an overt coronary artery disease with a cerebrovascular disease is frequently reported. However the real prevalence of atherosclerotic lesions at the carotid bifurcation in coronary patients is not well established. The aim of our study was to evaluate the prevalence of atherosclerotic involvement of the extracranial carotid arteries in a group of 141 patients undergoing coronary artery by-pass graft (CABG) and to verify whether any correlations between coronary and carotid artery disease exist. The extracranial carotid arteries have been studied by means of an echo-doppler (duplex) system, which combines a B-mode images with a pulsed doppler. A high prevalence (17.02%) of patients with a severe (greater than 50% diameter reduction) carotid involvement was detected (Tab. II). However, no correlations between the coronary and the carotid disease were found in terms of extension and severity (Tab. V). In conclusion, a systematic evaluation of the carotid arteries is recommendable in the coronary patients, candidates to CABG, even in the absence of cerebrovascular symptoms.

Adult↗
PubMed1986

Effect of captopril on left ventricular mass and function in hypertensive patients and in the rat.

Twenty-seven mild to moderate essential hypertensive patients were treated with captopril alone or combined with hydrochlorothiazide and left ventricular echocardiographic changes were evaluated after 1, 3 and 6 months. The left ventricular mass decreased slightly after 3 months, together with mean wall stress and total peripheral resistance, while the cardiac performance, as measured by fractional shortening and cardiac output, was unaffected. A high degree of individual variability was observed, and only 9 out of 20 patients examined after 3 months had a consistent reduction in left ventricular mass. The effect of captopril on the isomyosin composition was also evaluated in 4 normotensive rats after 12 weeks of drug administration. No interference with the physiological pattern was observed and no modifications of the biochemical and structural properties of the myocardium were detected.

Adult↗
PubMed1985

Synthesis and antibacterial activity of 3-(2-arylvinylen)-2-isoxazolines.

3-[2-(5-Nitro-2-furyl)vinylen]-2-isoxazoline (VIII) and 3-nitro-, 3-amino- and 3-acylaminostyryl-2-isoxazolines have been synthesized and tested for antibacterial activity. Compound (VIII) showed potent antibacterial activity in vitro against several strains of S. aureus and E. coli (two to eight times more active than furazolidone). None of the styryl derivatives exhibited significant activity.

Anti-Bacterial Agents↗
PubMed1985

Prevalence of atherosclerotic lesions at the carotid bifurcation in patients with asymptomatic bruits: an echo-Doppler (duplex) study.

The prevalence of atherosclerotic lesions at the carotid bifurcation with asymptomatic Meck bruits has been evaluated in 71 patients, 42 males, ages ranging from 19 to 84 yrs, referred to our non-invasive vascular laboratory for an echo-Doppler (duplex) scan, associated with spectral analysis (Mark V ATL with Flow analyzer 459). Fifty-nine patients had mid-neck or high-neck bruits (30 bilateral), 12 had low-neck bruits (4 bilateral). The internal carotid arteries were classified as normal, minimal stenosis (diameter reduction 20%), moderate stenosis (20-49%), severe stenosis greater than or equal to 50%), total occlusion. Twenty-four of the internal carotid arteries homolateral to a mid- or high-neck bruit were normal, 84% had stenosis of various degree (16% severe), 2% were occluded. Stenoses of various degree were also present on the contralateral side of the bruit. No lesions above a diameter reduction of 20% were present in the internal carotid arteries corresponding to a low-neck bruit. The echo-Doppler (duplex) system, being capable of spanning the whole spectrum of the internal carotid occlusive disease, allows us to limit the number of the invasive diagnostic procedures in asymptomatic patients.

Adult↗
PubMed1985

The double pre-beta very low density lipoprotein lipoproteinemia (DPBL): a new dyslipoproteinemic state.

A new dyslipoproteinemic state, characterized by two populations of very low density lipoprotein particles giving the electrophoretic appearance of two pre-beta bands, the double pre-beta lipoproteinemia, is described. Based upon the lipid and apoprotein composition, it can be inferred that the slow moving pre-beta component is probably made up of remnant very low density lipoprotein particles; the absence of apo B 48 in the very low density lipoprotein fraction in these subjects rules out the intestinal origin of this remnant. Clinical interest in the double pre-beta lipoproteinemia relates to its potential atherogenicity; in fact it seems to be causally associated with such pathological conditions as hypothyroidism, uremia and dialysis, which are frequently accompanied by clinical complications of atherosclerosis. Double pre-beta lipoproteinemia also shows familial aggregation. Six years follow-up in a large family kindred has demonstrated that the family members carrying the double pre-beta lipoproteinemia, develop an incidence of coronary and cerebrovascular events higher than that of family members without the double pre-beta lipoproteinemia.

Apolipoproteins B↗
PubMed1981

Synthesis, spectral behaviour and microbiological properties of some di(nitrothienyl)sulfides.

Six novel di)nitrothienyl)sulfides (I)-(VI) have been prepared either by condensation of suitable bromonitrothiophene derivatives with sodium sulfide or by hydrolysis of di-(3-nitro-2-thienyl)disulfide (XI), with ethanolic potassium hydroxide, followed by condensation of the resulting nitrothiophene thiolate with the appropriate bromonitrothiophenes. All compounds proved active, in vitro, against a number of gram-positive bacteria, at very low concentrations. Substitution of a thiophene nucleus by the benzene nucleus resulted in a decrease of activity. I.R. and U.V. spectral data are discussed.

Anti-Bacterial Agents↗
PubMed1980

[Synthesis of dithienyldisulfides. II].

The dithienyldisulfides (II a-e) were prepared by condensation of dipotassium nitroethylendithiolate and alpha-chlorocarbonyl derivatives, followed by oxidation with iodine. The N.M.R., I.R. and M.S. spectral behaviour is discussed. The activity against the leukemia P388 tumor system in mice was tested.

Animals↗
PubMed1977

[Synthesis of 2,3-diazaphenothiazine. X. 7- and 8-nitroderivatives of 1- keto and of 4-keto-2,3-diazaphenothiazine and their mixtures of oxidation on 5].

A description is given of the synthesis of 7- and 8-nitro-derivatives of 1-keto- and 4-keto-2,3-diazaphenothiazine, by cyclization with acids and hydrated alkaline sulfides (XIV) and (XV). Oxidation of these nitroderivatives (XI), (XII), (XVI) and (XVII) gives products corresponding to those obtained by oxidation of the heterocyclic S atom to sulfones (IV), (XIII), (VIII) and (XVIII). Nitration of 1-keto- and 4-keto-2,3-diazaphenothiazine (1) and (V) gives the 7-nitroderivatives with simultaneous oxidation of the sulfur to sulfoxide (II) and (VI); oxidation of these sulfoxides or sulfones gives the same products (IV) and (VIII) obtained by the methods described above. The same compounds are obtained also by nitration of 1-keto- and 4-keto-5,5-dihidroxy-2,3-diazaphenothiazine (III) and (VII).

Aza Compounds↗
PubMed1977

[Synthesis of dithienyldisulfides].

The synthesis of 2,2'-dithienyldisulfides, variously substituted in position 3 and/or 5 with --NO2, --NHCOCH3, --SO2NH2 groups and of 2,2'-dinitro-3,3'-dithienyldisulfide is described. The antitumor activity of these compounds was tested.

Antineoplastic Agents↗