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Biomedical subjects

G Conte

Publications and source records attributed to G Conte.

At least 145 records · Page 8Linked to original sources
PubMed1985

Platelet alpha 2-adrenoceptors in major depression: relationship with urinary 4-hydroxy-3-methoxyphenylglycol and age at onset.

Platelet alpha 2-adrenoceptor number and affinity were measured in 31 drug-free patients with major depressive illness utilizing 3H-clonidine as ligand. A significant negative correlation was found between number of alpha 2-adrenoceptors, baseline urinary 4-hydroxy-3-methoxyphenylglycol (MHPG) excretion, present age and age at onset of the disease. Kd did not correlate with any of these variables not with the Bmax of platelet alpha 2-adrenergic binding. Multiple regression analysis, with MHPG and age at onset as independent variables, explained variance for alpha 2-adrenoceptor density better than single regression (from 19% for MHPG and 30% for age at onset to 40%), with the addition of both these variables being significant.

Adult↗
PubMed1985

Mechanism of impaired urinary concentration in chronic primary glomerulonephritis.

To define the role of medullary damage and the influence of solute load and blood pressure (BP) in impairing urinary concentration, patients with chronic glomerulonephritis were investigated by histological and functional studies. In 59 biopsy specimens, the degree of medullary fibrosis was correlated inversely with urinary specific gravity and was significantly greater in hypertensive than in normotensive subjects. The following clearance studies were carried out in patients with a GFR of 15 to 40 ml/min in maximal antidiuresis: (1) Eight patients were studied while receiving a high sodium and protein diet and then after 1 week of low sodium, low protein diet; (2) ten patients were loaded with hypertonic saline (3%) to increase urine volume up to 25 to 30% of GFR; (3) the concentrating ability was compared in 15 normotensives and 15 hypertensives with comparable GFR; (4) the concentrating ability was studied in nine hypertensive patients before and after drug-induced normalization of BP. In (1) no change occurred in maximal urine osmolality (UOsm) even if fractional sodium excretion and filtered load of urea were reduced. In (2), values of UOsm fell below those of plasma osmolality. In (3), UOsm and negative free-water generation were lower in hypertensive than in normotensive subjects. In (4), normalization of BP was not associated with any change in UOsm. These results indicate that osmotic diuresis does not play a critical role in reducing urinary concentration. This defect is better accounted for by an intrinsic medullary damage, enhanced in hypertensive patients, which may impair the permeability of collecting ducts to water.

Adolescent↗
PubMed1985

Mechanism of increased plasma urea after diuretic therapy in uraemic patients.

To clarify why diuretic therapy raises plasma urea in patients with chronic renal failure, three groups of uraemic subjects were treated with frusemide for 6 days. In group 1 (n = 9), frusemide significantly decreased body weight and increased average plasma urea from 18.7 mmol/l to 28.8 mmol/l (P less than 0.001). this rise in plasma urea was secondary to reduced urea excretion, which occurred in spite of an increase in urea filtration. In group 2 (n = 7), frusemide was associated with salt replacement, in order to prevent salt depletion; in these patients neither reduction in urea excretion nor increase in plasma urea occurred. In group 3 (n = 10), the marked diuretic-induced fall in urea clearance was found to be independent of enhanced proximal tubular reabsorption (measured in water diuresis). These results show that the rise in plasma urea is due to increased tubular reabsorption of urea, presumably in the distal part of the nephron, secondary to extracellular fluid (ECF) volume depletion.

Body Weight↗
PubMed1985

Role of prostaglandins in captopril-induced natriuresis.

To determine whether prostaglandins (PG) contribute to captopril-induced natriuresis, 20 hypertensive subjects were assigned to one of the following three groups: group a, captopril (C) administration; group b, C + indomethacin (I); group c, I alone. Captopril was given in a dose of 100, 200, 400 mg/day and indomethacin in a dose of 100mg/day for one week. In group a (n = 10), natriuresis was clearly increased in the seven day periods with captopril in a dose of 200 and 400mg/day but not at 100mg/day. After captopril 200 or 400mg/day, but not 100mg/day, urinary PGE2 and PGI2 excretion significantly increased while filtration fraction fell due to a rise in renal plasma flow. Plasma aldosterone (PA) significantly decreased after C(p less than 0.05). In group b (n = 7), natriuresis disappeared during captopril 200 or 400mg/day and indomethacin administration even when PA decreased as in group a. In group c (n = 3), natriuresis was unchanged. In conclusion, natriuresis by C is critically dependent upon increased secretion of PG.

Adult↗
PubMed1984

[Initial experience with clotiapine in the treatment of heroin addiction].

Experience in treating heroin addicts with a major neuroleptic, Chlothiapin (Entumin Sandoz) is described. Treatment was begun on 16 cases and completed on 12. Slight signs of asthenia appeared in three cases. All patients completing the treatment achieved a normal sleeping pattern and reduced anxiety. Thus after a 7 day course patients could be transferred to a specialist drug addiction centre.

Adolescent↗
PubMed1984

On the development of the coronary arteries in human embryos, stages 14-19.

Each coronary artery in humans develops, initially, from two anlagen, one distal and the other proximal. The distal anlage, which is forerunner of the subepicardial branches of the coronary arteries, develops as subepicardial vascular networks on the atrioventricular and interventricular sulci and on the walls of the ventricles and bulbus; these networks are the right-posterior and left-anterior ones. The proximal anlage, which is forerunner of the truncus of the right and left coronary arteries, develops as several endothelial buds of the truncus arteriosus. Normally, only two buds, right and left, hollow out, increase in length and connect with the right and the left vascular networks, respectively, so that the coronary arteries are formed. The cardiac veins appear together with the coronary arteries, but as independent vessels. The authors advance a number of hypotheses as to the origin of certain variations and malformations of the coronary arteries.

Arteries↗
PubMed1984

Mechanism of impaired urinary concentrating ability in normokalemic primary aldosteronism.

Renal clearance studies were performed during anti-diuresis (before and after hypertonic saline infusion) and during water diuresis in three hypertensive patients with normokalemic primary aldosteronism (NPA) and in matched patients with normoreninemic essential hypertension (EH). The NPA patients showed an impaired ability to concentrate urine. By progressively increasing Cosm with saline loading, TcH2O plateaued both in NPA and in EH patients; in the former, however, the plateau occurred earlier and was lower than in the latter. In water diuresis, absolute values of CH2O were higher in NPA due to increased distal delivery secondary to impairment in proximal tubular reabsorption. Fractional CH2O (i.e. the ratio between CH2O and distal sodium delivery), however, was lower in NPA than in EH patients. Both in antidiuresis (after saline loading) and in water diuresis the NPA patients exhibited an enhanced fractional excretion of sodium. In one of NPA patients, clearance studies were repeated after adrenalectomy. In this patient, normalization of BP and reduction of body weight were associated with a rise in Uosm and a reduction in Cosm in antidiuresis; Uosm and Cosm were restored to pre-surgical values by expanding extracellular fluid volume (ECV) with saline loading. In summary our results suggest that ECV expansion is the mechanism by which urine concentration is impaired in patients with NPA.

Adult↗
PubMed1984

Hormonal changes and hair growth during treatment of hirsutism with cimetidine.

The effects on hair growth by treatment with cimetidine have been studied. This drug has been given orally to 4 women with simple hirsutism and 3 women with peptic ulcer as controls for a period of 9 months. Hair growth slowed down in all of the treated women but the results were not statistically significant. A significant decrease in urine 17-ketosteroids has been observed, while plasma levels of testosterone, 17-beta estradiol, progesterone, FSH, LH and prolactin, did not change substantially. It is concluded that, on the whole, cimetidine doses not seem to induce such results on hair growth as to claim a role in the treatment of hirsutism in other current regimes.

17-Ketosteroids↗
PubMed1984

Closure of the interventricular foramen and morphogenesis of the membranous septum and ventricular septal defects in the human heart.

The development of the atrioventricular and interventricular membranous septum was studied The interventricular foramen is closed by the growth of the endocardial crest of the interventricular muscular septum towards the cranio-ventral atrioventricular cushion and towards the part B of the outflow tract ridge B-3; the bulbus is septated by the apposition and fusion of parts A and B of the outflow tract ridges A-1 and B-3. The membranous septum develops from the crest of the interventricular muscular septum between the interventricular muscular septum and the right border of the atrioventricular cushions, where it forms the atrioventricular mesenchymal septum. This last develops towards the right surface of the interventricular muscular septum and forms the septal cusp primordium of he tricuspid valve; this is undermined, for which reason the septal cusp is cut off from the interventricular muscular septum at the 5th month of fetal life. From the 6th month of intrauterine life, the undermining extends to the atrioventricular mesenchymal septum, for which reason the right septal cusp becomes inserted in the right face of the atrioventricular mesenchymal septum which becomes divided into atrioventricular and interventricular. The Authors advance some hypotheses as to the origin of certain defects of the interventricular septum.

Animals↗
PubMed1983

Epidemiology of hypertension in children.

In 1979-80, a cross-sectional study was carried out in 7118 Neapolitan school children aged 10-15 years. In 1980-81 and 1981-82 a longitudinal study was performed in a group of children with blood pressure above the mean + 1SD (in age and sex related peers) and in a group with blood pressure less than mean + 1SD. In the whole population blood pressure increased with age from 10 to 14 years. The major determinant of blood pressure was body weight, followed by heart rate. Three hundred and ninety-eight children (5.6%) were hypertensive having blood pressure greater than mean + 2SD. In children followed longitudinally, blood pressure was very labile; only 13 per cent of those originally having blood pressure mean + 1SD, in fact, remained in the same category. All of these, however, had blood pressure greater than mean + 2SD throughout the study.

Adolescent↗
PubMed1983

Renal function in pregnant rats with two-kidney goldblatt hypertension.

This study was carried out in female Wistar-Münich rats with two-kidney, one-clip hypertension, using clipped normotensive rats as controls. Metabolic studies were performed in the first two weeks of pregnancy, consisting of daily measurement of systolic blood pressure (BP) (tail-cuff), body weight (BW), and salt and water balance. At the end of metabolic studies, glomerular dynamics were studied in the unclipped kidney by micropuncture. During pregnancy, urinary output of Na+ and water was greater in hypertensive than normotensive rats. The greater natriuresis accounted for a reduced Na+ retention and a lower increase in maternal BW. Micropuncture studies showed an impaired renal auto-regulation. These results show that hypertension in pregnancy causes a salt-losing tendency, that may be secondary to incomplete renal autoregulation.

Animals↗