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Biomedical subjects

L Chiandussi

Publications and source records attributed to L Chiandussi.

At least 37 records · Page 2Linked to original sources
PubMed1995

Levels of plasma neuropeptide Y and other vasoactive substances during head-up tilt in normal and essential hypertensive subjects.

Neuropeptide Y, a potent vasoconstrictor peptide with 36 amino acid residues, is co-stored and released with catecholamines in sympathetic nerve endings. In this study responses in circulating neuropeptide Y induced by baroreceptor activation during change from the supine to the head-up position was measured in normal subjects and untreated essential hypertensives. Furthermore, the relationships with plasma catecholamines, endothelin-1, renin and serotonin were studied. No significant differences of plasma neuropeptide Y were found between normotensive and hypertensive subjects, before or after postural changes, and there was no correlation with a range of the vasoactive substances studied. Our results suggest that plasma neuropeptide Y does not increase with noradrenaline on sympathetic activation during postural stress both in normals and in hypertensive subjects. In man, measurement of plasma neuropeptide Y during head-up tilt does not provide a useful estimation of sympathetic nervous activity.

Adult↗
PubMed1995

Spectral characteristics of heart rate and blood pressure variability in primary aldosteronism.

A disturbance of the autonomic cardiovascular function has been postulated in primary aldosteronism as a possible mechanism for hypertension. Using the method of spectral analysis of heart rate and blood pressure variability, the aim of this study was to assess sympathovagal interactions modulating cardiovascular function and baroreflex control in patients with primary aldosteronism. Seventeen patients (7 with adenomas and 10 with idiopathic hyperaldosteronism) and a control group of 11 essential hypertensives (EH) and 10 normotensive subjects were studied. Continuous finger blood pressure was measured using a Finapres device and heart rate was measured using an electrocardiographic monitor. The studies were conducted in each patient for 20 min in the supine position and 10 min during a passive head-up tilt to 60 degrees. The low frequency and the low frequency-to-high frequency ratio of systolic and diastolic blood pressures were significantly higher both in primary aldosteronism and in EH patients compared with normotensives (P < .01). Impaired response to tilt was found in the heart rate and blood pressure variability in primary aldosteronism and EH patients; the increase in low frequency was smaller than in normotensives. Baroreflex gain (assessed by alpha index) was less in primary aldosteronism and EH patients as compared with normotensives. These findings may suggest that volume expansion or sympathetically mediated central translocation of the blood volume, or both, could stimulate the cardiopulmonary receptors and impair the baroreflex gain. Our findings suggest that an enhanced peripheral vascular responsiveness to a normal sympathetic outflow may be involved in the pathogenesis of hypertension in primary aldosteronism.

Baroreflex↗
PubMed1995

Assessment of renal resistance index after captopril test by Doppler in essential and renovascular hypertension.

Ultrasonic duplex scanning has been validated as a noninvasive method to evaluate the kidney arteries and hemodynamic characteristics of renal blood flow in patients with renal artery stenosis. The purpose of our study was to assess the changes in renal vascular impedance in 22 patients with renovascular hypertension, as compared with 45 essential hypertensives and 15 normotensives, by using the Doppler parameter resistance index (RI) before and after a captopril oral test. After the captopril test the delta RI decreased significantly in the stenotic artery (P < 0.05). Univariate analysis showed that PRA values after captopril correlated inversely with the changes of RI only in the stenotic artery (P < 0.05). Thus, our findings suggest that the application of the captopril test to renal echo-Doppler may represent a feasible, noninvasive, and inexpensively useful tool in the screening studies aimed at diagnosing renovascular hypertension.

Administration, Oral↗
PubMed1995

Dopamine D5 receptor expression is unchanged in peripheral blood lymphocytes in essential hypertension.

The present study was designed to investigate possible changes in the expression of lymphocyte dopamine receptor in essential hypertension. The expression of dopamine D5 receptor was evaluated by radioligand binding techniques using [3H]-SCH 23390 as ligand. Plasma catecholamines, aldosterone levels and plasma renin activity were also measured. Eleven borderline hypertensive patients, 15 patient with the mild essential hypertension, 7 patients with moderate essential hypertension and 5 patients with severe essential hypertension were examined. Plasma catecholamine levels were assayed by high pressure liquid chromatography with electrochemical detection. Dopamine D5 receptor was measured by radioligand binding techniques. Plasma aldosterone levels and renin activity were determined by radio immunoassay. [3H]-SCH 23390 was specifically bound to human peripheral blood lymphocytes. The binding was time-, temperature- and concentration-dependent with a dissociation constant (Kd) value of 0.59 nM and a maximum density of binding sites (Bmax) of 223 pmol/10(6) cells. Dopamine competed with [3H]-SCH 23390 binding in the submicromolar range suggesting the labelling of a dopamine D5 receptor. No changes in the density of [3H]-SCH 23390 binding sites were observed in human peripheral blood lymphocytes between essential hypertensive patients and normotensive subjects. Also catecholamines, plasma renin activity and aldosterone levels were unchanged. In spite of the availability of a sensitive technique for measuring dopamine receptors in human peripheral lymphocytes, no change in their expression was noticeable in essential hypertension. This suggests that dopamine receptor analysis in essential hypertension is not a useful marker for investigating hypertension-dependent changes of the peripheral dopaminergic system.

Adult↗
PubMed1995

Role of alcoholic beverages in essential hypertensive patients.

To evaluate the importance of alcohol and other environmental factors in essential hypertensives, we conducted a cross-sectional study on 627 patients (322 women, 305 men) subdivided in four subgroups according to sex and presence or absence of drug therapy, to evaluate differences due to drugs and changes in life style. Multiple regression analyses were run where systolic and diastolic blood pressures were considered as separate dependent variables with the following independent variables: age, body mass index, physical activity, alcohol and coffee consumption, smoking, educational level; considered as continuous or categorical variables. eighty-eight per cent of all patients showed a moderate-low alcohol intake (1-50 g/day); wine was the preferred beverage. We found a negative independent relationship between mild/moderate alcohol consumption levels and systolic blood pressure in untreated men and untreated women, and no relationship between alcohol and diastolic blood pressure in all subgroups considered. Body mass index and age were positively associated with both systolic and diastolic blood pressure. Our data suggest that mild to moderate alcohol consumption does not affect blood pressure control in either treated or untreated hypertensive patients.

Age Factors↗
PubMed1994

Cardiovascular risk factors in adolescence: prevalence and familial aggregation.

BACKGROUND: In the field of primary prevention there is an increasing interest in screening pediatric populations for cardiovascular risk factors. The aim of this study was to determine the overall prevalence of high blood pressure (HBP), obesity, and sedentariness in a population of adolescents. The presence of familial aggregation for these factors was also evaluated. METHODS: The prevalence of HBP, obesity, and low physical activity was determined in 1413 adolescents ages 12-15 years (705 males, 698 females) randomly selected from Turin school children. The prevalence of HBP and obesity in parents was determined. RESULTS: One risk factor was found in 40.9% of females (2.4% HBP, 8.6% obesity, and 29.9% sedentariness) and 39.6% of males (2.8% HBP, 16.4% obesity, and 20.4% sedentariness); the concomitance of two or three risk factors were present, respectively, in 9.9 and 2.7% of females and 10.9 and 1.1% of males with a strong association of obesity and HBP. A significant familial aggregation for obesity was found and no particular relationship was found for BP. CONCLUSION: The ability to identify children developing a single or multiple risk factors is an important contribution to the prevention of serious cardiovascular diseases in adulthood.

Adolescent↗
PubMed1994

Statistical evaluation of circadian blood pressure rhythm during isradipine long-term therapy.

In this study, using the two-step truncated Fourier series with four harmonics, we analysed the diurnal blood pressure profile in 13 mild-moderate essential hypertensive patients during isradipine long-term therapy. Circadian parameters such as the amplitudes and phases of the four harmonics and the overall amplitude and phase were obtained from the model. The total duration of the study was 26 weeks. Ambulatory blood pressure was measured at 15-min, intervals using a Takeda TM 2420 device after 2 weeks of placebo and after 6 and 26 weeks of isradipine (5 mg daily) respectively. After 6 and 26 weeks therapy the blood pressure values showed a significant decrease, although the daily blood pressure curves obtained from Fourier analysis showed that the circadian rhythm was not altered by isradipine treatment. Both the night/day differences and the overall amplitude/acrophases were statistically significant at 0.6 and 26 weeks. According the nocturnal blood pressure fall, we found that long-term therapy with isradipine increased the number of patients with nocturnal blood pressure fall and reducing the early morning blood pressure rise. In conclusion, the two-step method Fourier analysis represents a novel and useful statistical approach to evaluate the presence of a significant diurnal blood pressure rhythm and to provide the circadian parameters of the 24-h blood pressure profile during pharmacological therapy.

Blood Pressure↗
PubMed1994

Plasma immunoreactive endothelin-1 in primary hyperaldosteronism.

This study evaluated the assessment of plasma endothelin-1 (ET-1) levels in primary aldosteronism and its correlation with other vasoactive hormones such as renin, aldosterone, catecholamines, arginine-vasopressin, and atrial natriuretic peptide. Plasma ET-1 was measured in 12 patients with primary aldosteronism (five adenomas and seven primary hyperplasia) and in 15 normal subjects. No significant differences were found in plasma ET-1 between controls and hypertensive patients both in adenoma and primary adrenal hyperplasia (8.8 + 1.6 pg/mL v 6.2 + 1.4 pg/mL v 6.5 + 1.0 pg/mL, P = NS, respectively). Further, no significant correlations were found among ET-1 and vasoactive hormones. In conclusion, these findings show that there are no differences in ET-1 levels between primary aldosteronism patients and healthy subjects. Circulating ET-1 is not involved in the hypertension in primary aldosteronism.

Adenoma↗
PubMed1994

Analysis of 24-h blood pressure profile by Fourier series during lacidipine therapy.

In the present study, we examined the circadian profile of blood pressure (BP) in 10 patients with moderate essential hypertension before and after 6 months of lacidipine therapy. Ambulatory BP was measured at 30-min intervals using SpaceLabs 90207. To account for the unequal time intervals between successive readings, BP means and variances were weighted for the time span between successive readings, and weighted linear-regression analysis was applied. The 24-h BP values were carried out using Fourier analysis, comparing the values from the baseline with those after 24 weeks of lacidipine. After 24 weeks BP values showed a significant decreased compared with baseline values (all p < 0.01). The daily BP curves obtained from Fourier analysis with four harmonics showed that the significant circadian rhythm in nine patients was not altered by lacidipine treatment. The night/day differences were statistically significant at 24 weeks vs. 0 week (all p < 0.01). The overall amplitude and acrophase of the BP curve were statistically significant at 24 weeks (all p < 0.01). After 24 weeks of lacidipine therapy, according to the nocturnal BP fall, we found three intermediate dippers, six dippers, and one non-dipper. By use of the two-step Fourier analysis method, which provides a formal and statistical method to evaluate the presence of a significant diurnal BP rhythm and parametrization of the 24-h BP recordings, we showed that lacidipine long-term therapy is effective in lowering BP and preserving the diurnal BP rhythm.

Antihypertensive Agents↗
PubMed1994

Pharmacological characterization and autoradiographic localization of dopamine receptors in the human adrenal cortex.

The pharmacological characteristics and the anatomical localization of dopamine D1-like and D2-like receptors were studied in sections of the human adrenal cortex using radioligand binding and autoradiographic techniques. [3H]SCH 23390 was used as a ligand of D1-like receptors, whereas [3H]spiroperidol was used to label D2-like receptors. No specific [3H]SCH 23390 binding was detectable in sections of the human adrenal cortex. On the other hand, [3H]spiroperidol was bound to sections of the adrenal gland in a manner consistent with the labelling of dopamine D2-like receptor sites. The binding was time, temperature and concentration dependent, belonging in the range of concentrations of the radioligand used for a single class of high-affinity sites. The dissociation constant (Kd) averaged 2.7 nmol/l, whereas the maximum density of binding sites (Bmax) was 160 nmol/mg tissue. Experiments on the pharmacological specificity of [3H]spiroperidol binding to sections of the human adrenal cortex revealed that clozapine was the most powerful displacer of [3H]spiroperidol from sections of the human adrenal cortex. This suggests the presence in the human adrenal cortex of dopamine receptors of the D4 subtype. Light microscope autoradiography showed the highest density of specific [3H]spiroperidol binding sites in the zona glomerulosa and to a lesser extent in the zona reticularis. Only sparse [3H]spiroperidol binding sites were localized in the zona fasciculata. The possible functional consequences of this localization of dopamine D2-like receptor sites in the human adrenal cortex are discussed.

Adrenal Cortex↗
PubMed1994

Plasma endothelin in NIDDM patients with and without complications.

OBJECTIVE: To measure plasma endothelin 1 (ET-1) levels in uncomplicated non-insulin-dependent diabetes mellitus (NIDDM) and investigate whether ET levels may be related to angiopathy, blood pressure, metabolic control, or duration of illness. RESEARCH DESIGN AND METHODS: Plasma levels of ET-1 were measured in 44 NIDDM patients, of whom 24 had uncomplicated diabetes, 20 had angiopathy, and 10 had hypertension. In 21 patients, the duration of illness was > 10 years, and in 23 the duration of illness was < 10 years. Serum creatinine levels, microalbuminuria, and HbA1c were determined simultaneously. Thirty normotensive healthy (nondiabetic) individuals (20 men and 10 women) served as control subjects. RESULTS: No significant statistical differences in plasma ET-1 levels were found among all diabetic patients, diabetic patients with and without angiopathy, diabetic patients with different durations of diabetes, and normal subjects. No significant correlation of plasma ET-1 with blood pressure, age, serum creatinine level, duration of diabetes, HbA1c, or diabetic complications was found. CONCLUSIONS: Plasma ET-1 levels are similar in patients with NIDDM and healthy subjects and do not seem to act as a marker of diabetic complications.

Adult↗
PubMed1994

[Diabetes, obesity, hypertension and the autonomic nervous system].

Functional changes of the autonomic nervous system may represent a common pathophysiologic factor in the association between non insulin-dependent diabetes, obesity, and essential hypertension. In all these conditions a number of sympathetic and/or parasympathetic dysfunctions consistent with autonomic neuropathy or simply with functional adaptations to haemodynamic changes have been reported. Autonomic neuropathy is a well known diabetic complication which is responsible for some clinical aspects of different severity. Subtle sympathetic and parasympathetic abnormalities possibly affecting thermogenesis have been shown in obese people. An increased sympathetic activity has been proposed as one of the pathogenetic mechanisms of essential hypertension. Finally, the association between diabetes, obesity, hypertension and sympathetic overactivity could be explained by a common trans-membrane ionic disturbance with an increase of intracellular calcium and a decrease of both intracellular magnesium and pH.

Autonomic Nervous System↗
PubMed1993

Twenty-four-hour power spectral analysis by maximum entropy method of blood pressure in primary hyperaldosteronism.

In the present study we estimated the periodic profiles and variance structure of systolic blood pressure, diastolic blood pressure, heart rate and mean arterial pressure by using an autoregressive model of power spectrum, Maximum Entropy Method (MEM) in 8 patients with primary aldosteronism, during long-term therapy with nicardipine slow release. The four blood pressure variables were measured at 30-min intervals, using a noninvasive device (Spacelabs 90202) in 8 hypertensive patients of whom 6 with idiopathic aldosteronism (IHA) and 2 with dexamethasone-suppressible aldosteronism (DSH), before and after 24 weeks of 80 mg nicardipine daily. Blood pressure data were processed by MEM and spectral profiles were obtained. During nicardipine therapy all patients showed a significant decrease of 24-h ambulatory blood pressure values (p < 0.01). Before therapy, spectrum analysis by MEM indicated the presence of high frequency distribution of peaks for SBP, DBP, MAP and HR. The MEM power spectrum showed an increase in amplitude of sharp peaks of systolic, diastolic, MAP and heart rate in all patients after therapy at 24 h corresponding to the circadian rhythm blood pressure. Furthermore, the trend of these variables synchronized themselves in the same period after 24 weeks of nicardipine therapy, with spectral patterns of blood pressure similar to those of normotensive subjects. This chronobiologic approach, by Maximum Entropy Method, may be used as an alternative statistical analysis to search for possible rhythmic behavior of ambulatory blood pressure data before and after pharmacological treatment in secondary hypertensive patients.

Activity Cycles↗
PubMed1993

Long-term follow-up of patients with chronic hepatitis C treated with different doses of interferon-alpha 2b.

Eighty patients with chronic hepatitis C who completed a previously reported randomized controlled trial on the efficacy of interferon-alpha 2b were followed up for at least 36 mo after therapy discontinuation. Seventeen patients (21.2%) maintained normal ALT values throughout the follow-up; 63 (78.8%) either did not normalize the levels of ALT or relapsed during the follow-up. A significantly greater proportion of patients treated with 3 million units of interferon three times a week subcutaneously for 48 wk were long-term responders compared with patients treated for 24 wk. Sex, age, hepatitis C virus antibody status, source of infection and pretreatment levels of ALT were not predictive of long-term response. Cirrhosis was found to be an unfavorable predictive factor. After 3 yr of follow-up, clearance of viremia was observed in 58.9% of the 17 long-term responders but in none of the non-responders (p = 0.002). E2-NS1 antibody tested negative in 88.2% of long-term responders and in 14.3% of nonresponders (p = 0.001). Fifty-nine percent of long-term responders tested negative for C100-NS4 antibody compared with 14.3% of nonresponders (p = 0.031). No significant change was observed in other antibodies. Four long-term responders underwent liver biopsy 2 yr after discontinuation of therapy. All four patients had normal liver histology compared with baseline assessment of chronic active hepatitis in three and chronic persistent hepatitis in the other. Three of the four were negative for serum hepatitis C virus RNA.

Adult↗
PubMed1993

[Tauro-ursodeoxycholic acid vs. ursodeoxycholic acid in the dissolution of biliary calculi. Results of a single blind study].

Out of 34 patients enrolled and randomized, 31 completed the 6 months study period. Fifteen were treated with TUDCA, and 16 with UDCA. Dosage for both drugs was 10 mg/kg body weight daily. Superiprisingly, TUDCA was not found to be more active than UDCA in dissolving, totally or partially, the gallbladder stones; indeed, total dissolution was more frequent in the UDCA group. Since the two groups were similar as to number and size of the stones, the better results with UDCA cannot be attributed to the characteristics of the calculosis but must be ascribed to the molecule used. Both drugs induced an improvement in dyspeptic symptoms, but from this point of view, too, UCDA was more effective than TUDCA (p < 0.01). Finally, tolerability was also significantly better for UDCA, although TUDCA was altogether acceptable.

Adolescent↗
PubMed1993

Changes in autonomic nervous function over a 5-year period in non-insulin-dependent diabetic patients.

One hundred and eight non-insulin-dependent diabetic patients who had been tested for autonomic dysfunction in 1984/85 were re-evaluated 5 years later. Autonomic function was assessed by means of four cardiovascular tests (heart rate variation during deep breathing and standing, and blood pressure variation after standing and sustained handgrip). Eighteen subjects were lost to follow-up; in the 90 patients who completed the study, both the deep breathing and the handgrip test significantly worsened (respectively from 13.7 +/- 7.8 to 11.6 +/- 6.3 beats min-1 p < 0.01, and from 16.9 +/- 8.2 to 12.7 +/- 7.1 mmHg, p < 0.001), whereas both the 30:15 ratio and the variation of blood pressure on standing did not change. The impairment of a comprehensive evaluation score (from 2.5 +/- 1.7 to 3.0 +/- 1.5; p < 0.05) also confirmed the gradual deterioration of autonomic function over the study period.

Autonomic Nervous System↗