Concordance between brain 18F-FDG PET and cerebrospinal fluid biomarkers in diagnosing Alzheimer's disease. / Concordancia entre la PET cerebral con 18F-FDG y los biomarcadores en líquido cefalorraquídeo en el diagnóstico de enfermedad de Alzheimer.

OBJECTIVES: Cortical posterior hypometabolism on PET imaging with 18F-FDG (FDG-PET), and altered levels of Aß1-42 peptide, total Tau (tTau) and phosphorylated Tau (pTau) proteins in cerebrospinal fluid (CSF) are established diagnostic biomarkers in Alzheimer's disease (AD). An evaluation has been made of the concordance and relationship between the results of FDG-PET and CSF biomarkers in symptomatic patients with suspected AD. MATERIAL AND METHODS: A retrospective review was carried out on 120 patients with cognitive impairment referred to our Cognitive Neurology Unit, and who were evaluated by brain FDG-PET and a lumbar puncture for CSF biomarkers. In order to calculate their Kappa coefficient of concordance, the result of the FDG-PET and the set of the three CSF biomarkers in each patient was classified as normal, inconclusive, or AD-compatible. The relationship between the results of both methods was further assessed using logistic regression analysis, including the Aß1-42, tTau and pTau levels as quantitative predictors, and the FDG-PET result as the dependent variable. RESULTS: The weighted Kappa coefficient between FDG-PET and CSF biomarkers was 0.46 (95% CI: 0.35-0.57). Logistic regression analysis showed that the Aß1-42 and tTau values together were capable of discriminating an FDG-PET result metabolically suggestive of AD from one non-suggestive of AD, with a 91% sensitivity and 93% specificity at the cut-off line Aß1-42=44+1.3×tTau. CONCLUSIONS: The level of concordance between FDG-PET and CSF biomarkers was moderate, indicating their complementary value in diagnosing AD. The Aß1-42 and tTau levels in CSF help to predict the patient FDG-PET cortical metabolic status.

Increased activity of the Mg2+/Na+ exchanger in red blood cells from essential hypertensive patients.

Epidemiological, clinical, and experimental evidence suggests a relation between Mg2+ metabolism and essential hypertension. The aim of the present study was the detection of abnormalities of the erythrocyte Mg2+/Na+ exchanger in essential hypertensive patients. We studied 66 untreated essential hypertensive patients and 36 normotensive control subjects. Maximal efflux rates of total Mg2+ efflux and the Na(+)-dependent and Na(+)-independent components of Mg2+ efflux were determined in Mg(2+)-loaded red blood cells. Mg2+/Na+ exchanger was calculated as the Na(+)-dependent component of the Mg2+ efflux. Mean values of Mg2+/Na+ exchanger were clearly elevated in hypertensive subjects with respect to normotensive control subjects [184.7 +/- 15.7 versus 84.4 +/- 6 mumol(L.cell.h)-1; P < .001]. This elevation was due primarily to the increased total Mg2+ efflux [324.2 +/- 21.9 versus 257.9 +/- 17.3 mumol(L.cell.h)-1; P < .05], whereas the Na(+)-independent component was not significantly different between the groups [154.5 +/- 11.8 versus 173.4 +/- 15.5 mumol(L.cell.h)-1; P = NS]. Moreover, total erythrocyte Mg2+ content was slightly reduced in hypertensive patients with respect to normotensive control subjects (1.84 +/- 0.04 versus 2.07 +/- 0.04 mmol/L.cell; P < .001). Using the 99% confidence limits of the normotensive population as the normal range, 30 (45.5%) hypertensive subjects showed values of Mg2+/Na+ exchanger higher than 160 mumol(L.cell.h)-1. The Mg2+/Na+ exchanger was inversely correlated with basal intraerythrocyte Mg2+ content (r = -.323; P = .001). From a clinical point of view, we found a positive correlation between diastolic blood pressure values and Mg2+/Na+ exchanger (r = .246; P < .05) in the sample of essential hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative evaluation of the antihypertensive efficacy of once-daily amlodipine versus nitrendipine with 24-hour ambulatory blood pressure monitoring in essential hypertension.

We compared the antihypertensive efficacy of once-daily amlodipine (AM) versus nitrendipine (NTR) by 24-h ambulatory blood pressure monitoring (24-h ABPM) in 32 patients with mild to moderate essential hypertension (EH). After a 2-week single-blind, placebo run-in period, patients were randomized in a double-blind, parallel fashion: 14 received AM 5 mg and 18 NTR 10 mg. After 2 weeks, dose was adjusted if necessary (AM 10 mg or NTR 20 mg) and continued for another 6-week period. At the end of the placebo period and during the last week of treatment, patients underwent 24-h ABPM. Initial office BP mean values were similar in both groups (169.8 +/- 14/102.5 +/- 6 vs. 167.1 +/- 14/98.7 +/- 5 mm Hg, respectively, p = NS). A comparable decrease in office mean values of systolic BP (SBP, -22.3 +/- 13 vs. -19.1 +/- 16 mm Hg) and diastolic BP (DBP, -12.0 +/- 5 vs. -8.1 +/- 8 mm Hg) was observed. Nevertheless, 24-h ABPM mean values differed significantly between patients treated with AM or NTR with regard to 24-h SBP (120.0 +/- 10 vs. 132.5 +/- 1 mm Hg, p = 0.01). Moreover, the average decrease in 24-h SBP (-19.3 +/- 6 vs. -5.2 +/- 11 mm Hg, p = 0.0036) and 24-h DBP (-10.7 +/- 4 vs. -3.7 +/- 6 mm Hg, p = 0.0047) was higher in the AM group, with no changes in 24-h heart rate (HR). At equivalent once-daily dosage, AM was more effective than NTR in decreasing BP assessed by 24-h ABPM.

Chronic alcohol intake induces reversible disturbances on cellular Na+ metabolism in humans: its relationship with changes in blood pressure.

The effect of chronic alcohol consumption on Na(+)-K+ ATPase, Na(+)-Li+ countertransport, outward Na(+)-K(+)-Cl- cotransport system and the Na+ leak was investigated in red blood cells from 18 normotensive subjects with a daily alcohol intake of more than 150 g. The study was repeated after 3 months of alcohol withdrawal, and results were compared with a group of 20 healthy normotensive teetotalers. Maximal efflux rate (Vmax) and apparent dissociation constant for internal Na+ (KNa) of the Na(+)-K+ pump and the Na(+)-Li+ countertransport were significantly higher in alcohol consumers. A positive correlation between daily alcohol intake and Vmax of both transport systems (p less than 0.05) was observed. These values significantly decreased after alcohol withdrawal. A simultaneous stimulation of the Na(+)-K(+)-Cl- cotransport system after alcohol withdrawal was also observed. Blood pressure values were higher in alcoholics (133.7/82.3) than in abstainers (121.4/75 mmHg) and significantly decreased (128.5/76.9 mmHg) after withdrawal. A positive correlation between the stimulation of the Na(+)-K(+)-Cl- cotransport and the decrease of blood pressure after withdrawal was observed. In conclusion, chronic alcohol intake induces disturbances on red blood cell Na+ metabolism that dissipate with the cessation of drinking. Similar abnormalities also reported in humans and animals with primary hypertension have been associated in the pathogenesis of essential hypertension. Therefore, the pressor effect of chronic alcohol intake could be mediated through these changes in cellular Na+ metabolism.

[Prevalence of lipid disorders and their course after blood pressure control in essential arterial hypertension]. / Prevalencia de los trastornos lipídicos y su evolución tras el control tensional en la hipertensión arterial esencial.

BACKGROUND: Arterial hypertension and hyperlipidemia are the principal factors of cardiovascular risk with an association which appears to obey common pathogenic bonds. In the present study the initial prevalence of hypercholesterolemia and hypertriglyceridemia was determined in a sample of essential hypertensives and the long term effect of different antihypertensive treatments on lipid metabolism has been analyzed. METHODS: Total cholesterol, its LDL and HDL fractions and plasmatic triglycerides were determined in a sample of 158 hypertensive patients prior to the initiation of antihypertensive treatment and following one year of normotension. RESULTS: The initial prevalence of lipid disturbances was of 47% (isolated hypercholesterolemia 17%, isolated hypertriglyceridemia 14% and mixed anomalies 16%). After one year of tension control the initial prevalence was not modified. In the patients controlled with a low sodium diet a decrease in total cholesterol and an increase in cholesterol-HDL were observed in those treated with atenolol, and a decrease in cholesterol-LDL was seen in those receiving captopril. The group treated with nifedipin presented no significant variations of the lipid profile. CONCLUSIONS: The prevalence of lipid disturbances is greater among the hypertensive patient than in the general population. The rational treatment of a hypertensive patient must not only regard blood pressure figures but also control the other risk factors since the drugs commonly used in the treatment of arterial hypertension generally demonstrate a neutral effect on lipid metabolism.

[The clinical profile of hypertensive patients can predict the need for combining a second or third drug with atenolol in the initial treatment of light and moderate essential arterial hypertension]. / El perfil clínico de los pacientes hipertensos puede predecir la necesidad de asociar un segundo o tercer fármaco al atenolol en el tratamiento inicial de la hipertensión arterial esencial leve y moderada.

In this study the clinical, biological, radiologic, electrocardiographic, and hormonal characteristics of 80 patients with slight or moderate essential arterial hypertension in whom the treatment with atenolol alone or associated with chlorthalidone or with a third agent normalized the arterial pressure during a period of one year, are revised. Atenolol given alone at the dose of 50 to 100 mg per day normalized the blood tension in 44 (55%) patients, in 26 cases (32.5%) the association of chlorthalidone 25 mg/day was required, and in the remaining 10 patients (12.5%) a third pharmacologic agent was needed. Patients who required the association of three agents (group C) had systolic arterial pressures significantly higher than those observed in patients treated with atenolol alone (group A) (176.6 +/- 14.3 vs 161.4 +/- 12.9 mmHg, p less than 0.01) and higher to those measured in patients who required the association of chlorthalidone (group B) (176.6 +/- 14.3 vs 162.8 +/- 15 mmHg, p less than 0.05). On the other hand the 44 hypertensive patients controlled with monotherapy showed a lower incidence of cardiovascular complications (6.8% in group A, 38.5% in group B, and 30% in group C, p = 0.0042), they required acute treatment for hypertensive crisis (34.1% in group A, 73.1% in group B, and 66.7% in group C, p = 0.0041), and they showed electrocardiographic signs of left ventricular hypertrophy or overload (26.2% in group A, 60% in group B, and 42.9% in group C, p = 0.0228).(ABSTRACT TRUNCATED AT 250 WORDS)

[Massive pleural effusion secondary to hydronephrosis]. / Derrame pleural masivo secundario a hidronefrosis.

The most frequent causes of pleural effusion are congestive heart failure, advanced cirrhosis and nephrotic syndrome. In some rare cases urine can be found accumulated in the pleural compartment, being this entity denominated urinotorax. This phenomenon is generally considered secondary to an urinary obstruction or to an urinoma on the same side as the effusion through mechanisms not yet clarified. Given that it is a benign condition, easily resolved by clearing the obstruction of the urinary tract and that there is little information about it in the literature, we report a case of a massive pleural effusion secondary to hydronephrosis.