Effects of salt sensitivity on neural cardiovascular regulation in essential hypertension

Salt-sensitive hypertensive subjects, as defined by conventional categorical classification, exhibit alterations of autonomic cardiovascular control. The aim of our study was to explore whether, in hypertensive subjects, the degree of autonomic dysfunction and the level of salt sensitivity are correlated even when the latter is only mildly elevated and displays under-threshold values. Salt sensitivity of 34 essential hypertensive subjects was assessed on a continuous basis by the salt sensitivity index after low- and high-sodium diet. Beat-by-beat finger blood pressure was recorded after each diet period. Autonomic cardiovascular control was evaluated by spectral analysis of blood pressure and pulse interval and by assessment of spontaneous baroreflex sensitivity (sequence technique). Salt sensitivity and baroreflex sensitivity showed a negative relationship during low and high sodium intake, starting from low values of the salt sensitivity index. All spectral indexes of pulse interval, except the ratio between low- and high-frequency powers, were inversely related to salt sensitivity index after high sodium intake. In subjects with lower salt sensitivity, baroreflex sensitivity and pulse interval power in the high-frequency band were higher after high sodium intake than after low sodium intake. In contrast, subjects with a higher salt sensitivity index showed lower values of baroreflex sensitivity and pulse interval power in the high-frequency band, uninfluenced by salt intake. Our results provide the first demonstration of an impairment of parasympathetic cardiac control in parallel with the increase in the degree of salt sensitivity, also in subjects who were not ranked as salt-sensitive by the conventional categorical classification.     

Consistency of professional goals and health care needs in medical education and training

The university with the fragmentation of knowledge in the disciplines required by an in-depth study and by research had to reconsider over and over the doctor's curriculum in order to make professionalism able to concretely and consistently address health needs. The main points of this new process of medical education and training are presented as an analytical list illustrated in its single aspects. These subjects tackle only some of the main problems that substantiate the renewal of medical education for the development, in a harmonious sysnthesis, of cognitive competences (knowledge), psychomotor competences (know how to do) and psychoemotional competences (know how to be).     

Dopamine blockade abolishes the exaggerated natriuresis of essential hypertension

We studied natriuresis during central hypervolaemia by immersing eight normal subjects and eight patients with uncomplicated essential hypertension up to the neck in water, either in the absence (study 1) or presence (study 2) of dopamine blockade by metoclopramide. Water immersion without metoclopramide induced an exaggerated natriuresis in hypertensives compared with normotensives (P less than 0.001). This occurred in the presence of identical hormonal (plasma renin activity, plasma aldosterone and prolactin), renal (creatinine clearance) and pressor responses in both groups (study 1). The marked natriuresis seen during water immersion alone in normotensives was significantly blunted (P less than 0.02) but not abolished during water immersion with addition of metoclopramide. On the other hand, the exaggerated natriuresis found in hypertensives during water immersion alone was completely abolished during water immersion plus dopamine blockade by metoclopramide (study 2). Similar hormonal, renal and pressor changes were detected in both normotensive and hypertensive subjects during water immersion plus metoclopramide administration. Our data demonstrate that metoclopramide abolishes the exaggerated natriuretic response seen in hypertensives during volume expansion produced by water immersion, and suggest that dopamine may play a critical role in mediating the hypernatriuresis of essential hypertension.     

Studies on cell water and electrolytes in chronic renal failure

Studies were carried out in 10 normal subjects and in 16 patients with moderately severe chronic renal failure (CRF) to determine the quantities of potassium (K), sodium (Na) and water in muscle tissue obtained by needle biopsy and in white cells (WBC) from peripheral venous blood. Depletion of intracellular K with high levels of Na and normal water were found in patients with CRF. Therefore, the cellular electrolyte pattern was not substantially different from that reported by others in patients with advanced uremia although there was no increase in intracellular water (as can occur in end-stage CRF). These data suggest that in end-stage CRF accumulation of intracellular water could be relatively independent of intracellular electrolyte balance.     

Immunogenetics of severe respiratory infections: models for the development of new therapeutic strategies

Innate and adaptive immunity plays a critical role in the defence of the lung and other mucosal surfaces exposed to micro-organisms. Anti-microbial peptides and proteins, cytokines and chemokines are important immune weapons as they build up the protective front for the respiratory tract. The notion that susceptibility to infectious diseases may be inherited is widely accepted and, as it is the failure to activate adaptive immunity that may allow infection to become established and progress toward invasion and dissemination, the recognition of specific gene defects affecting the ability of the immune system to overcome invading pathogens may shed light upon those mechanisms of immune regulation that are playing the most critical roles. The aim of the present review is to discuss some of the advances in infection immunogenetics that may lead to identify new strategies in the development of new anti-infectious and anti-inflammatory drugs.     

Discordance between physician's and parent's global assessments in juvenile idiopathic arthritis

OBJECTIVE: To investigate the discrepancy between physician's and parent's global assessments of disease status and the factors explaining discordance in patients with juvenile idiopathic arthritis (JIA). METHODS: The mothers of 197 patients with JIA rated the child's overall well-being on a 10 cm visual analogue scale (VAS) and the attending physician rated the child's overall disease activity on a 10 cm VAS. A discordance score was calculated by subtracting the physician's global assessment from that of the parent's, leading to the definition of three patient groups: (1) no discordance, when physician's and parent's assessments were within 1 cm of each other; (2) negative discordance, when parent's assessment was underrated relative to the physician; and (3) positive discordance, when parent's assessment was over-rated relative to the physician. Negative and positive discordance was defined as 'marked' when the difference between the two assessments was greater than 3 cm. RESULTS: No discordance was found in 40.6% of the patients. Negative discordance was found in 51.3% of the patients, with 34% showing marked discordance. Positive discordance was found in 8.1% of the patients, with 2% showing marked discordance. Significant differences between groups included a shorter disease duration among patients with a markedly positive discordance (P = 0.02) and a greater frequency of ongoing second-line drug therapy among patients with no discordance or with positive discordance (P = 0.008). Patients with no discordance or with marked positive discordance had a significantly lower joint counts (P = 0.02-0.004). CONCLUSION: Parents and physicians often perceive the health status of children with JIA differently, with parents providing most frequently lower rating.     

Medical treatment of nephrolithiasis.

The medical treatment of nephrolithiasis is aimed in particular at the prevention of relapses, even though in some cases, such as cystine or uric acid lithiasis, the calculi also can be dissolved on site. When the diagnosis and metabolic profile have been performed correctly, medical treatment is effective in a large number of patients. The greatest difficulty is the patient's compliance with the most suitable prevention measures and the frequency of follow-up controls. This compliance can be influenced significantly by the amount of time that the doctor spends to explain the origin of the disease. This article reviews the main methods available for the medical treatment of various nephrolithiasis types, namely water intake, diet, and drugs, supplying the relevant information about the mechanism of action, metabolic consequences, indications, evidence provided from studies, dosage, efficacy, and side-effects. Finally, brief simplified guidelines are given for the medical treatment of stone disease caused by calcium oxalate or calcium phosphate, uric acid, cystine, and struvite.     

The effect of fruits and vegetables on urinary stone risk factors

BACKGROUND: The overall effect of fruit and vegetable intake on urinary stone risk profile is not yet known. METHODS: We studied the effect of a two-week period of fruit and vegetable elimination on urinary stone risk profile in 12 normal adults, and of supplementing the diet with a fair quantity of low-oxalate fruits and vegetables in 26 idiopathic calcium stone formers characterized by hypocitraturia and a very low fruit and vegetable intake in their usual diet. RESULTS: In the normal subjects, the elimination of fruits and vegetables from the diet decreased the urinary excretion of potassium (-62%), magnesium (-26%), citrate (-44%) and oxalate (-31%), and increased that of calcium (+49%) and ammonium (+12%) (P < 0.05 for all). The relative saturation for calcium oxalate and calcium phosphate increased from 6.33 to 8.24 (P = 0.028), and from 0.68 to 1.58 (P = 0.050), respectively. In the hypocitraturic stone formers, the introduction of these foods in the diet increased urinary volume (+64%), pH (from 5.84 to 6.19), excretion of potassium (+68%), magnesium (+23%), and citrate (+68%), while it decreased the excretion of ammonium (-18%) (P < 0.05 for all). The relative saturation for calcium oxalate and uric acid fell from 10.17 to 4.96 (P < 0.001), and from 2.78 to 1.12 (P = 0.003), respectively. CONCLUSION: The total elimination of fruits and vegetables in normal subjects brings about adverse changes in the urinary stone risk profile that are only partially counterbalanced by a reduction in oxalate. In contrast, the addition of these foods to the diet of hypocitraturic stone formers not used to eating them not only significantly increases citrate excretion without affecting oxalate excretion, but also decreases calcium oxalate and uric acid relative saturation.