Low dose of dopamine is commonly used after kidney transplantation as a reno-protective agent, although its benefits are controversial. Dopamine may increase renal blood flow, decrease resistive index (RI), and induce urine output in normal kidneys. Many authors hypothesized that the vasculature of a denervated renal transplant may not respond to dopamine in the same fashion as healthy native kidneys, which led us to find other drugs to attenuate the ischemia-reperfusion (I/R) injury. Fenoldopam is a selective dopamine1 (DA1) receptor agonist, most of the activity of which resides in the R-enantiomer, which also shows weaker alpha 2-adrenoceptor antagonist activities. Fenoldopam produces a vasidilatory effect in vascular beds that are rich in vascular DA1 receptors, producing increased renal blood flow at doses that do not affect blood pressure. In addition to its renal vasodilator activity, fenoldopam is natriuretic, possibly resulting from a direct effect of DA1 receptors on the proximal convoluted tubule. In animals with spontaneous or drug-induced renal failure, fenoldopam improves renal function. The aim of this study was to investigate the possible effects of fenoldopan mesylate in recent kidney transplants. Creatinine, blood urea nitrogen, urine output, and renal vascular resistive index (IR) were measured using Doppler ultrasound. Two groups of patients with no statistical differences in demographic data were treated with dopamine or fenoldopan, showing no significant difference but a trend favoring the fenoldopan group.

Adult↗

PubMedDate not supplied

Who are the non-dippers? A better definition via the blood pressure circadian rhythm.

OBJECTIVE: The non-dipping phenomenon (NDP) can be better interpreted when considering that blood pressure (BP) shows a within-day variability which is the expression of a circadian rhythm (CR). PATIENTS AND METHODS: The NDP was investigated at the light of the BP CR by analysing the ambulatory BP monitoring of 298 essential hypertensive patients (EHP), 84 secondary hypertensive patients (SHP), as well as 93 normotensive subjects (NS). According to the rhythmometric validation, the investigated subjects were defined "rhythmic" (R) or "non-rhythmic" (NR). RESULTS: The non-dippers (ND) were found among not only the EHP (14%) and SHP (27%) but also the NS (16%). The percentages of R ND were 9%, 4% and 20%, respectively in EHP, SHP and NS. The R ND were characterized by a nocturnal phase-shift (100% in NS), associated with an amplitude increase (50% in EHP) or a mesor increase (50% in EHP; 100% in SHP) in BP CR. The NR ND were characterized by an amplitude almost negligible (100% in NS) associated with a mesor increase (100% in EHP; 100% in SHP). CONCLUSIONS: The detection of a NDP associated with a rhythmicity suggests that the criterion with which the ND are identified cannot be used for making inferences on the BP CR in HP or NS. The rhythmic characteristics in ND suggest that the rhythmometric analysis is fundamental for identifying the abnormal time structure of BP 24-h values in the presence of the NDP.

Adult↗

PubMedDate not supplied

Hunger sensation in Graves' disease before and after pharmacological therapy.

PURPOSE: Hunger sensation (HS) provides information about the need of eating in order to counterbalance the energy expenditure (EE). HS was, thus, investigated in patients affected by Graves' disease (PAGD), a clinical condition characterized by excessive EE. MATERIALS AND METHODS: Ten newly diagnosed PAGD were investigated before and after therapy. Thirty clinically healthy subjects (CHS) were investigated as controls. The investigated subjects were asked to provide the 24-h profile of their HS by subjectively self-rating (from 1 to 10 hunger units) their orectic perception (OP) at regular intervals of 30 minutes (orexigram). The orexigrams were investigated via the conventional descriptive statistics as well as the Single-Cosinor method. RESULTS: PAGD were found to show a very consistent increase of their HS (hyperorexia), whose day-night variability was, still, the expression of a circadian rhythm, characterized by an elevation in its oscillatory level and extent. Interestingly, the pre-treatment hyperorexia was seen to show a normalization (eurexia) after pharmacological therapy. CONCLUSIONS: According to these results, it can be affirmed that hyperorexia is a clinical sign of Graves' disease, which is obtained via mechanisms of tonic and amplitude modulation of the HS circadian rhythm. Because of the eurexia after remission, it can be argued that the hyperorexia is a theleological response really aimed at increasing food intake in order to counterbalance the excessive EE which characterizes the thyrotoxicosis.

Adult↗

PubMedDate not supplied

Age-related trend for blood pressure circadian rhythm in normotensive healthy subjects: estimates provided by the clinospectror method.

The present study investigates how blood pressure (BP) circadian rhythm (CR) changes in its rhythmic properties as a function of chronological age in normotensive healthy subjects (NHS). The age-related trend for BP CR was investigated via the Clinospectror method, a periodic-linear analysis of regression for rhythmic parameters. The study was performed on 437 NHS (219 males and 218 females, ranging in age from 1 year to 102 years), who were monitored in their 24-h BP via a noninvasive automated recorder. An age-related trend was detected for the three properties of BP CR, i.e., mesor (M), amplitude (A) and acrophase (cent). Such a trend was positive for M and A, and negative for cent. According to the clinospectrometric formula, the BP CR can be classified as a "dianaclinous rhythm", i.e., a rhythm which increases in its oscillatory level and extent with advancing years. The documented age-related trend for the rhythmic properties suggests that the biological clock which regulates the BP CR in human beings undergoes a resetting of its mechanisms of tonic, amplitude and phasic modulation as a function of chronological age. The readjustment of the pressure clock may be regarded as one of the physiological features which characterize the aging process in human beings.

Adolescent↗

PubMedDate not supplied

[Individualization of the "presumptive risk" of hypertensive crisis using fractals interpolation of the 24-hour arterial pressure. Study of patients with essential hypertension].

PURPOSE: The present study applies the "fractal interpolation" (FI) to blood pressure that was nonivasively and ambulatorily monitored over a day-night period in essential hypertensives. The purpose is the identification of cases who are at a "presumptive risk" (PR) for hypertensive crisis. MATERIALS AND METHODS: The investigation was performed on 380 ascertained cases of essential hypertension, who underwent a non-invasive ambulatory monitoring of 24-h blood pressure. The FI was applied to the ambulatory mean arterial pressure. RESULTS: The FI showed that the PR of hypertensive crisis can be found in 14% of the investigated essential hypertensive patients. Such a risk is not significantly higher in dippers as compared to non-dippers, and in those who showed a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be abolished. Furthermore, no significant difference was found between the cases "at risk" and "not at risk" as far as the spectrum of harmonic formants of the 24-h blood pressure pattern is concerned. CONCLUSIONS: The PR of hypertensive crisis is not correlated to the dipping/nondipping condition, circadian rhythmicity and complex harmonic structure of 24-h blood pressure pattern. Its occurrence depends essentially from the disorder that is detectable in 24-h blood pressure pattern. Therefore, such a PR in essential hypertensives may be attributed to the mechanisms, likely neurovegetative, which confer a non-linear chaotic variability to 24-h blood pressure values.

Adult↗

PubMedDate not supplied

[Determination of the "presumptive risk" of hypertensive crisis with fractal interpolation of 24-hour arterial pressure. II: study with secondary hypertensive patients].

PURPOSE: The present study applies the "fractal interpolation" (FI) to 24-h blood pressure nonivasively and ambulatorily monitored over a day-night period in secondary hypertensives. The purpose is the evaluation of the prevalence for a "presumptive risk" (PR) of hypertensive crisis. MATERIALS AND METHODS: The study was carried out in 108 cases of secondary hypertension, who were non-invasively and ambulatorily monitored for their 24-h blood pressure values. The FI was applied to the time-qualified values of the mean arterial pressure. RESULTS: The PR of hypertensive crisis was found in 11% of the investigated secondary hypertensive patients. Such a risk shows a not significant prevalence in dippers as compared to non-dippers, and in those who showed a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be abolished. Additionally, a not significant difference was found between the cases "at risk" and "not at risk" as far as the spectrum of harmonic formants of the 24-h blood pressure pattern is concerned. CONCLUSIONS: The PR of hypertensive crisis is not associated with the dipping/non-dipping phenomenon as well as the circadian rhythmicity of blood pressure. Its occurrence in secondary hypertensives is essentially related to the disorder that is detectable in blood pressure non-linear variability. Therefore, such a risk may be caused by neurovegetative mechanisms which notoriously confer a non-linear chaotic variability to 24-h blood pressure pattern.

Adult↗

PubMedDate not supplied

[Identification of "presumptive risk" of hypertension crises with fractal interpolation of the 24-hour arterial pressure. III: study of normotensive subjects].

PURPOSE: The present study is devoted to identify the normotensive subjects who are at a "presumptive risk" (PR) for hypertensive crisis, by applying the "fractal interpolation" (FI) to blood pressure 24-h pattern. MATERIALS AND METHODS: The investigation was performed on 109 ascertained cases of normotension, who underwent a non-invasive ambulatory monitoring of their 24-h blood pressure, by applying the FI to their daily mean arterial pressure. RESULTS: The study showed that the PR for hypertensive crisis can be found in 12% out of the investigated normotensives. The proportion of such a risk is not significantly higher in non-dippers as compared to dippers. Vice versa, the prevalence of cases with a PR for hypertensive crisis was found to be significantly increased in normotensives who were deprived by a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be preserved. Furthermore, the cases "at risk" were found to show a different spectrum for the harmonic formants which compose the complex harmonic structure of the blood pressure 24-h variability. CONCLUSIONS: The PR for hypertensive crisis in normotensives seems to be increased by the loss of the blood pressure circadian rhythm, due to a change in the harmonic structure which confers the 24-h periodicity to the hemodynamic variable. This means that the abrogation of the blood pressure circadian rhythm in conditions of normotension promotes an adjunctive disorder for which the PR for hypertensive crisis is augmented.

Adult↗