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Biomedical subjects

S Ghione

Publications and source records attributed to S Ghione.

At least 91 records · Page 5Linked to original sources
PubMed1986

Correlation between endogenous digoxin-like immunoreactivity and 3H-ouabain displacement on erythrocyte membranes in extracts of human plasma.

The existence of endogenous cardiac glycoside-like compounds and their property of being recognized by anti-digoxin antibodies is still a matter of controversy. In order to investigate this problem, endogenous digoxin-like immunoreactivity (measured by RIA) and digitalis-like radioreceptor activity (measured by displacement of 3H-ouabain from erythrocyte membranes) were assessed in plasma extracts of normal adults, pregnant women and newborns. These three groups were chosen because of their known widely different levels of digoxin-like immunoreactivity. Compared to adults, newborns and pregnant women had significantly higher levels not only of immunoreactivity but also of displacement of 3H-ouabain binding, the latter being due, according to Scatchard analysis, to a decrease of the affinity of ouabain to its cellular receptor rather than to its maximal binding capacity. Furthermore, immunoreactivity and binding displacement correlated significantly. Our data indicate that one (or more) compounds with cardiac glycoside-like properties (both immunological and at the receptor level) are present in the plasma of newborns and pregnant women, and confirm the idea that radioimmunological methods may be useful in studying endogenous inhibitors of the sodium pump.

Adult↗
PubMed1986

Comparison of pain perception in normotensives and borderline hypertensives by means of a tooth pulp-stimulation test.

Recent studies indicate a reduced sensitivity to pain in genetically and experimentally hypertensive rats. A similar finding is also reported for human established hypertension. However, to our knowledge, no data have been reported in borderline hypertension. The aim of this study was to assess in subjects with borderline hypertension the sensory and pain thresholds by a noninvasive pulp-stimulation test performed with a commercial pulp tester that delivered stepwise increased electrical stimuli to four healthy teeth. The data reported are the means of measurements. In order to assess the possible importance of differences in the selection of the controls, two distinct groups of normotensives were chosen, one of volunteers and the other of outpatients. Significantly higher values for the pain and sensory thresholds were observed in borderline hypertensives compared with pooled normotensives. No significant effect on pain perception could be observed for sex, whereas a significant tendency toward higher threshold levels was found for younger subjects. In two normotensive groups, the sensory and pain thresholds were significantly higher in volunteers than in patients. These results suggest that changes in pain perception are present not only in established hypertension but also in borderline hypertension and, moreover, that differences in the selection of normotensive controls can have important influences on the results.

Adult↗
PubMed1986

Acute hypotensive effect of calcium antagonists and endogenous digitalis-like immunoreactivity in human essential hypertension.

Evidence has been provided on the increased presence, in essential hypertension, of endogenous digitalis-like factor(s) [DLIS, digoxin-like immunoreactive substance(s)] able to cross-react with antidigoxin antibodies and to inhibit the membrane-bound sodium-potassium pump. An inhibition of the sodium pump could lead, in smooth muscle cells, to an increase of intracellular calcium ions and to an increase of total peripheral resistances. In this study the relation between plasma levels of DLIS and the acute hypotensive effect of a calcium antagonist (nifedipine) has been evaluated in a group of borderline to severe hypertensive patients and in a control group of normotensive subjects. The results obtained confirm that the hypotensive effect of nifedipine is related to pretreatment blood pressure and show, only in hypertensive patients, a significant relation of DLIS with both pretreatment blood pressure and blood pressure decrement induced by nifedipine. These findings are compatible with a possible role of DLIS in modulating cellular calcium handling.

Adult↗
PubMed1985

Asymmetric septal hypertrophy and sympathetic overactivity in normotensive hemodialyzed patients.

Sympathetic activity has been evaluated in 23 chronic uremic normotensive patients on long-term hemodialysis. M-mode and bidimensional echocardiographic finding of asymmetric septal hypertrophy (ASH) was shown in seven (30.4%). Sympathetic function was assessed by determining arterial plasma norepinephrine (plasma NE) and epinephrine (plasma E) in supine and upright positions, both before and after dialysis. After dialysis standing caused a significant increase in plasma NE levels in the patients with ASH in comparison to the patients without ASH and the control group. A significant decrease in mean blood pressure (mBP) and a sharp heart rate (HR) increase were detected in the patients without ASH, whereas mBP and HR were unchanged in the patients with ASH. Predialysis serum creatinine and fasting triglycerides were found to be significantly higher in the group with ASH. These results suggest that sympathetic overactivity may play a role in the development of interventricular septum hypertrophy. This increased neurosympathetic responsiveness is probably related to the counteraction of the postural dialysis-induced hypotension.

Adult↗
PubMed1985

Hypotensive effect of plasma exchange in immune complex nephritis.

The effect of plasma exchange (PE) on blood pressure (BP) in 20 hypertensive patients (9 with mixed cryoglobulinemia, 7 with systemic lupus erythematosus, and 4 with idiopathic glomerulonephritis) was evaluated retrospectively. In each PE 1.5-2.5 L of plasma was replaced with an equal volume of 4% albumin polysaline solution. The frequency of PE was three times per week for the first 2 weeks and twice per week subsequently. Sixteen patients were on hypotensive treatment at the onset of PE. Their systolic/diastolic BP was 171 +/- 4.7/102 +/- 3.0 mm Hg (mean +/- 1 SEM). After 4 weeks, BP decreased to 141 +/- 2.8/89 +/- 2.3 mm Hg (p less than 0.001), although in 10 patients antihypertensive drug therapy had been reduced or discontinued. The most marked decrease of BP occurred after the first week (152 +/- 5.3/92 +/- 2.9 mm Hg), and this decrement correlated remarkably well with pressure levels before PE despite the great heterogeneity of the individual patients (for diastolic BP, r = 0.87, p less than 0.001; for systolic BP, r = 0.60, p less than 0.01). A mild decrease of serum creatinine was observed during PE, but its time course was different from that of BP, and did not correlate with this parameter.

Adolescent↗
PubMed1985

Acute effect of plasma exchange on arterial blood pressure and plasma renin activity.

Blood pressure (BP) decreases significantly in patients with immune complex nephritis and hypertension in the course of therapeutic plasma exchange (TPE). To investigate possible underlying mechanisms of this effect, the variations of supine and upright BP and plasma renin activity (PRA) acutely induced by PE (performed by isovolumetric replacement of plasma with 4% albumin in saline solution) were analyzed in six patients. On the average, both supine and upright BP decreased after TPE; however, statistical significance was obtained only for upright systolic BP. Supine and upright PRA did not change significantly, although a clearly blunted response to posture was observed in three patients. The changes of BP induced by TPE were apparently not due to a functional depression of the renin-angiotensin system, since the more marked decrements in BP were observed in the patients with lower basal PRA.

Adolescent↗
PubMed1985

Arterial blood pressure and the renin-angiotensin-aldosterone system during postural changes in hypertensive patients with unilateral renal mobility.

Unilateral renal mobility was identified in 27 out of 100 essential hypertensive patients by examination of renal scintiphotos. The pattern of response to postural changes of blood pressure (BP), plasma renin activity (PRA) and plasma aldosterone concentration (PAC) was investigated in 11 patients with renal mobility and without treatment and compared with that of an age- and sex-matched group of untreated hypertensives without renal mobility. The patients with renal mobility had higher BP levels (X +/- SD mm Hg: supine 185 +/- 39/112 +/- 18 vs. 149 +/- 18/97 +/- 14; upright 167 +/- 38/108 +/- 17 vs. 144 +/- 7/93 +/- 10; p less than 0.05). Significant correlations were obtained in the patients with renal mobility (but not in those without renal mobility) between upright PRA and PAC (p less than 0.001), their postural variations (p less than 0.01) and between upright PRA (and PAC) and BP levels (p less than 0.05). The high prevalence of renal mobility in hypertension and the relationship observed between the activated renin-angiotensin-aldosterone system and BP in this condition suggest the importance of searching for unilateral renal mobility when examining the renin-angiotensin-aldosterone system in hypertensive patients, particularly during postural manoeuvres.

Adult↗
PubMed1985

Electrocardiogram blood pressure and systolic time intervals long term monitoring in ambulant patients.

Ambulatory monitoring of the intra arterial blood pressure (IBP), through the Selyg-Oxford System, has been used so far primarily for studies on hypertension. Aim of our study is to explore the possibility of obtaining from IBP indications useful to extend its field of application. The study will investigate: the usefulness of the continuous monitoring of the systolic time intervals (STI), measured from IBP as ventricular performance indicators, the increasing of specificity of the ECG allowed by the simultaneous beat by beat estimate of the STI's, the possibility of achieving the same information from non invasive peripheral pressure transducers. In this paper we are presenting the results obtained from the combined analysis of the STI's, ECG and IBP in a first series of 13 patients, selected out of 50 on the basis of the highest number of episodes of IBP variations, to allow the evaluation of the algorithms performances in severe conditions.

Blood Pressure↗
PubMed1985

The intraarterial blood pressure monitoring in the evaluation of patients with dizziness and/or fainting.

Ambulatory blood pressure (BP) monitoring has been extensively utilized, so far, for studying BP profile and hypotensive treatment in arterial hypertension. In this paper, preliminary data will be reported from a clinical study on the possible contribution of the combined ECG and BP monitoring in clarifying mechanisms of dizziness in patients with multiple or complex cardiovascular problems. Results are shown of three patients with ischaemia, arrhythmias and/or episodes of hypotension, and of three patients with borderline hypertension and marked fluctuations of BP.

Arrhythmias, Cardiac↗
PubMed1985

Comparison of sensory and pain threshold in tooth pulp stimulation in normotensive man and essential hypertension.

Recent studies indicate a diminished responsiveness to noxious stimuli in arterial hypertension in the experimental animal. A similar finding is also reported in the only study published to our knowledge on this subject in man. The aim of the study was to assess in humans the sensory and pain threshold by a non-invasive tooth pulp stimulation test (stepwise increased electrical stimuli delivered by a commercial pulp tester). Subjects had to report when they started to feel pulp stimulation and when this became painful. The data reported are the means of the measurements on four healthy teeth in each subject. Significantly higher values (expressed as relative units [RU]) were found in 28 non-treated essential hypertensives compared with 33 normotensive controls for sensory threshold (40.64 +/- 8.07 versus 29.96 +/- 6.82 RU, P < 0.0001) and for pain threshold (55.67 +/- 12.74 versus 42.08 +/- 12.58 RU, P < 0.001). Multivariate analysis of variance showed that this difference was apparently not related to age and sex. These data lend further support to the view that pain modulation may be altered in the hypertensive state in man.

Adolescent↗
PubMed1985

Acute effect of captopril on single kidney glomerular filtration rate in arterial hypertension.

Recent studies have reported that captopril can acutely induce a marked decrease of glomerular filtration rate in kidneys affected by renal artery stenosis, an effect detectable by scintigraphic techniques. Experience which confirms and extends this observation, obtained in five patients with renovascular hypertension, is reported here. For comparison, eight essential hypertensives and six patients with non-vascular unilateral renal diseases were studied. In each patient the ratio of glomerular filtration rate between the two kidneys was estimated during two consecutive scintigraphic studies with the glomerular tracer 99mTc-DTPA: in all renovascular patients captopril induced a marked decrease of glomerular filtration rate on the affected side, whereas negligible changes were observed in all other subjects. These results confirm that captopril may almost completely suppress glomerular filtration in kidneys affected by unilateral renal artery stenosis, an effect which may not be apparent clinically because of compensation by the other kidney, but which is scintigraphically detectable. Renal scintigraphy after captopril is easy to perform and non-invasive. It therefore seems to be a promising tool for the screening of renovascular hypertension.

Captopril↗
PubMed1984

Digoxin-like immunoreactivity in normal human plasma and urine, as detected by a solid-phase radioimmunoassay.

Reports on the presence of digoxin-like immunoreactive substance(s) (DLIS) in the plasma and urine of several animal species and a few human test subjects prompted us to undertake to confirm the presence of DLIS in plasma and urine of normal persons and to investigate some characteristics of this antibody-DLIS binding. For this purpose we used a modified radioimmunoassay kit involving antidigoxin antibody-coated test tubes and 125I-labeled digoxin to measure DLIS in urine and concentrated plasma of ostensibly healthy subjects. In 12 separate experiments with plasma the mean sensitivity was 5.12 (SD 1.11) pg per tube, expressed as digoxin. There was no significant cross reactivity with human serum albumin in concentrations up to 200 g/L. The mean DLIS value (in digoxin equivalents) for plasma from 24 normal subjects was 33.58 (SD 14.24) ng/L. Its mean concentration in urine from five subjects was 315.00 (SD 91.38) ng/L.

Adult↗
PubMed1981

Comparison of outward and inward Na+/K+ cotransport-mediated fluxes in erythrocytes of essential hypertensive patients. Preliminary results.

A hereditary defect in the outward ouabain-resistant, furosemide-sensitive (ORFS) Na+/K+ cotransport has recently been reported by Garay and Meyer in erythrocytes of essential hypertensive patients and some of their normotensive offsprings. Since Na+/K+ cotransport in erythrocytes operates bidirectionally, the same defect might be detectable in the ORFS component of K+ influx rate. To test this hypothesis outward and inward Na+/K+ cotransport measurements were performed in erythrocytes of hypertensives and normotensive controls. Our preliminary results confirm the observation of a reduced outward cotransport in essential hypertension and also suggest that inward cotransport may be reduced in essential hypertension.

Adult↗