Morphometry of peptide-containing nerves in gut muscle layers: a quantitative approach to the study of autonomic neuro-muscular junctions.

A method for the quantitative assessment of peptide-containing nerves in the gastrointestinal muscle layers is described. Tissue samples are sectioned obliquely, at 45 degrees, in the plane bisecting the long axes of longitudinal and circular muscle fibres, and peptide-containing nerve fascicles are revealed by immunofluorescence. Cross-sectioned fascicles are counted (number/area of muscle) and their length density per volume of muscle layer is calculated. The composition of immunostained nerve fascicles is also assessed, by counting peptide-containing fibres in each, while peptide transmitter co-distributions are studied in parallel using adjacent tissue sections. Thus, the approach described provides a means for the delineation of both quantitative tissue distribution and composition of autonomic neuro-muscular junctions in the gastro-intestinal tract.

Ambulatory blood pressure monitoring and cardiovascular function tests in multiple system atrophy.

Cardiovascular tests (CT) of autonomic function and non-invasive ambulatory blood pressure (BP) and heart rate (HR) monitoring were performed in 17 patients with multiple system atrophy (MSA) (mean age 61 +/- 9 years) and in 12 healthy subjects matched for sex and age. CT showed severe autonomic dysfunction with orthostatic hypertension (OH) in eight patients with MSA (47%) (Group I). The remaining nine out of the 17 patients didn't show BP abnormalities during CT but an impaired HR reflex response was found (Group II). BP monitoring showed a reversed circadian BP rhythm in Group I with higher night-time than day-time values, a blunted circadian BP pattern in Group II and a normal day-night BP reduction in controls. Day-night HR reduction was poor in Group II and absent in Group I. Post-prandial hypotension was evaluated after a standard meal. In Group I systolic/diastolic BP fell within 30 minutes after meal (from 135 +/- 16/89 +/- 13 to 118 +/- 17/73 +/- 12 mmHg; p < 0.05) and after two hours had not returned to basal levels. In Group II a reduction of only systolic BP was found within 45 minutes after meal and persisted for one hour. OH clinically identifies a subgroup of MSA patients with a more severe BP dysregulation characterized by severe post-prandial hypotension and reversed circadian BP rhythm. CT and ambulatory BP monitoring are useful tools in identifying early stage of cardiovascular autonomic impairment.

[The role of diuretics in antihypertensive therapy]. / Il ruolo dei diuretici nella terapia antiipertensiva.

Hypertensive therapy based on diuretics is time-honored. Thiazides represent the most commonly used class of diuretics for uncomplicated hypertension because of economic motivations, their tolerance and efficacy both as monotherapy and in combined treatment with other agents. Clinical studies using diuretics and beta-blockers reported that thiazide treatment prevents the development of malignant hypertension, renal and heart failure, hypertensive retinopathy, and reduces in five years overall mortality of 33%, cardiovascular mortality of 41%, fatal and non-fatal cerebrovascular events of 51% and the risk of coronary events of 15%. The less than expected risk reduction of cardiovascular disease raised many concerns about the possibility of adverse biochemical changes of thiazides through their effects on lipids, electrolytes and glucose metabolism. However, the real clinical significance of these metabolic effects remains actually uncertain and needs further investigation. The treatment of the hypertensive patient cannot be adequately managed using a merely adjunctive step-care criterium. Hypertensive subjects have different haemodynamic, metabolic and endocrine disorders and a tailored treatment should consider the different activities of the various agents as monotherapy or in association in the single patient.

[Diagnosis of left atrial enlargement with electrocardiogram. A misplaced reliance]. / La diagnosi di ingrandimento atriale sinistro per mezzo dell'elettrocardiogramma. Una fiducia malriposta.

We analyzed the performance of the electrocardiogram in the diagnosis of left atrial enlargement in 1000 unselected consecutive patients (585 men and 415 women, mean age 46 +/- 17 years) with different cardiovascular diseases or clinically normal. Echocardiography was used as reference method to assess left atrial dimension. The following electrocardiographic criteria were considered: total P-wave duration in leads D1, D2 or D3 > or = 110 ms; P terminal force in lead V1 equal to or more negative than -0.04 mm-s, and P-wave notching in leads D1, D2 or D3 with a peak to peak interval > or = 40 ms. A total of 89 subjects (8.9%) fulfilled the echocardiographic criteria for left atrial enlargement, defined as a left atrial dimension above the upper limit of the normal 95% predicted interval calculated as a function of age and body surface area. In the whole group 67 subjects (6.7%) had at least one of the electrocardiographic criteria for left atrial enlargement. In only 23 patients there was agreement between electrocardiogram and echocardiogram in the diagnosis of left atrial enlargement. The three electrocardiographic indexes had specificity > or = 97%, however sensitivity was unacceptable (< or = 18%). Negative predictive value was high (> or = 91%) but positive predictive value was poor (< or = 35%).(ABSTRACT TRUNCATED AT 250 WORDS)

QT interval and QT dispersion in multiple system atrophy (Shy-Drager syndrome).

To evaluate the influence of autonomic function on the QT interval and QT dispersion, 18 patients (10 males and 8 females; mean age 61 +/- 9 years) with multiple system atrophy (MSA, Shy-Drager syndrome) were studied. Cardiovascular tests were performed to assess the degree of autonomic dysfunction. The QT interval, corrected QT (QTc), QT dispersion (QTd), corrected and adjusted QTd were calculated from a standard 12-lead electrocardiogram. Fifteen healthy subjects matched for sex and age were studied as controls. Nine MSA patients showed severe autonomic dysfunction with orthostatic hypotension. In the remaining patients definite autonomic impairment was found. No statistically significant difference was found in QTd and only a trend towards higher values of maximal QTc was found in patients compared with controls. QTc prolongation, defined as greater than the mean +/- 2 SD of the controls, was detected only in three out of the 18 MSA patients (17%). No correlation was found between the severity of autonomic impairment and repolarization parameters. Our data suggest that chronic autonomic impairment in patients with MSA does not significantly affect ventricular repolarization and ventricular dispersion.