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Biomedical subjects

E Fommei

Publications and source records attributed to E Fommei.

At least 19 recordsLinked to original sources
PubMed1996

Report of the Radionuclides in Nephrourology Committee on renal clearance.

The need for simple and accurate methods to measure renal function is self-evident. This need increases as techniques for intervention become available. The demand for evaluation of individual kidney function has increased with its role in the diagnosis and follow-up of unilateral renal disease and in decision making for conservative or surgical treatment based on residual renal function. The role of nuclear medicine in this area has been inhibited by confusion about conflicting methodologies. This report is meant to provide guidance to those centers that would like to initiate clearance procedures but have difficulty in choosing appropriate methodology.

Glomerular Filtration Rate↗
PubMed1995

Renal nuclear medicine.

The measurement of renal function has been a major field of interest in nuclear medicine. Many studies in the literature are still dedicated to this subject, with the aim of replacing the traditional urinary clearance methods with simpler and easier techniques. Simplified plasma clearance methods appear of sufficient accuracy to estimate global kidney function, except in very low function in which urinary clearance is still indicated. Gamma-camera methods have also been developed that, although of a lesser accuracy than the in vitro techniques, offer the important advantage of allowing renal imaging with the estimation of separate kidney function. Because of the intimate link between kidney function and structure, the diagnosis of nephrourological diseases has represented an important goal of nuclear medicine research. The functional information attainable with radionuclides is a valuable complement to the morphological information of imaging techniques such as x-ray computed tomography, ultrasonography, and magnetic resonance imaging. Recent contributions of nuclear medicine to the progress of clinical nephrology include the evaluation of renal function and the diagnostic work-up of renovascular hypertension, obstructive nephropathy, urinary tract infection, and renal transplantation.

Captopril↗
PubMed1993

Captopril radionuclide test in renovascular hypertension: a European multicentre study. European Multicentre Study Group.

The diagnostic work-up of renovascular hypertension is still controversial. The efficacy of renal scintigraphy with technetium-99m diethylene triamine pentaacetate (DTPA) before and after captopril (scintigraphic captopril test) was evaluated in a multicentre study. All 380 hypertensive patients in the study underwent renal arteriography; 125 had renal arterial stenosis > or = 70%, and 54 had a technically successful intervention to correct the stenosis. The post-captopril study had a sensitivity of 93% and a specificity of 100% for predicting blood pressure response to intervention, if renal function was normal and a combination of quantitative parameters was applied (individual kidney uptake index < 40%, time to peak activity < 2 min or > 10 min). In the entire population renal artery stenosis > or = 70% was detected with a sensitivity of 83% and a specificity of 93% if renal function was normal. In patients with abnormal renal function the performance of the test was worse, owing to a lower specificity which could be increased by using only time parameters. The performance of the test was optimal when the post-captopril findings were examined; no improvement was achieved by evaluation of the changes induced by captopril from the baseline. The test can thus be simplified by performing only a post-captopril study for routine use: a negative test would exclude a curable form of renovascular hypertension in > 80% and a positive test would predict it in > 90% of the patients selected for suspicion of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

European Captopril Radionuclide Test Multicenter Study. Preliminary results. Inspective renographic analysis. The European Captopril Radionuclide Test Multicenter Study Group.

Captopril radionuclide test (CRT) has been introduced in clinical practice as a screening test for renovascular hypertension, since it allows the detection of the decrease of glomerular filtration rate that may be induced by angiotensin converting enzyme inhibition (25 mg oral captopril) in kidneys ipsilateral to a renal artery stenosis. However, due to the low prevalence of the disease, experiences in single centers may hardly satisfy the need for representative series of patients to validate the test. Nineteen centers participated in a collaborative study (CRT European Multicenter Study) that collected data from 424 patients. Here we report on the first results obtained by inspective renographic analysis. The captopril radionuclide test greatly potentiated the diagnostic performance of conventional renography and the accuracy was maximal when relying simply on postcaptopril findings alone. Specificity was 84.1% in the overall population and 91.8% in uncomplicated patients without nephropathy and renal insufficiency. Taking into account the sole arteriographic diagnosis, sensitivity was 73.2% or 90.7% for the subjects with unilateral or bilateral stenosis and an angiographic degree of stenosis greater than or equal to 70%. On the other hand, when a successful outcome of blood pressure after revascularization or nephrectomy was considered as the gold standard for the diagnosis of renovascular hypertension, a high sensitivity was obtained (92.7%). Moreover, the test became negative after intervention in the great majority (88%) of patients who had a positive preintervention CRT and a normalization of blood pressure after revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Atrial natriuretic peptide during different pacing modes in a comparison with hemodynamic changes.

The study investigates the response of atrial natriuretic peptide (ANP) to different cardiac pacing modes in comparison with hemodynamic changes. Ten patients underwent Swan-Ganz catheterization during pacemaker implant. Atrioventricular and ventricular pacing were performed consecutively at three pacing rate levels (80, 100, and 110 ppm). Blood samples were taken from the pulmonary artery for ANP determination, both basally and at the end of each pacing period. Concomitantly, mean pulmonary capillary wedge pressure (PCWP) and mean pulmonary artery pressure (PAP) were measured. Cardiac output (CO) was determined by thermodilution both basally and during the 110 ppm steps. During atrioventricular pacing, whereas no significant changes were observed for ANP, PCWP and PAP, CO increased significantly (P less than 0.0005). At the beginning of ventricular pacing hemodynamic parameters and ANP levels were comparable with those of baseline conditions. During subsequent ventricular pacing PCWP and ANP increased significantly at the 110 ppm rate step (P less than 0.05). PAP did not change significantly, whereas CO decreased in all cases (P less than 0.01). A positive correlation was observed between ANP and PCWP during ventricular (P less than 0.001), but not atrioventricular pacing. The results, while confirming the hemodynamic advantages of atrioventricular pacing, point to a major stimulation of ANP secretion during ventricular pacing. This fact, together with the observed drop in CO and the correlation between ANP and PCWP, suggest that the increase of ANP in ventricular pacing may be the expression of a compensatory mechanism to the hemodynamic disadvantages of atrioventricular asynchrony.

Aged↗
PubMed1989

Reduced cardiovascular efficiency and increased reactivity during exercise in borderline and established hypertension.

In this study, exercise capacity was evaluated in patients with borderline and established, uncomplicated, essential hypertension as compared to normal subjects. To this aim, the response of blood pressure, heart rate and cardiac work to a multi-stage exercise test was investigated by analyzing the results of linear regression fitting of cardiovascular parameters (ie, heart rate, systolic blood pressure and rate-pressure product (RPP)) versus time of exercise. Compared to normal patients, both essential and borderline hypertensive patients had a shorter average duration of exercise test (ie, a decreased exercise capacity), always negative for transient myocardial ischemia. This was in spite of a mild increment of maximal RPP (+19% and +10% v normal patients, respectively). Reduction of exercise duration in borderline and established hypertensive patients was related to the higher RPP at rest (+26% and +56% related to normal patients, respectively) and to the steeper slopes (rates of increment) of heart rate systolic pressure and RPP during exercise. Interestingly, in the overall population of normal and hypertensive subjects, the slopes of heart rate and RPP were directly correlated with basal blood pressure. In conclusion, these data indicate a decreased exercise tolerance in both established and borderline hypertensive patients without documented myocardial ischemia. This abnormality, which appears to be due to a disproportional increment during exercise not only of systolic pressure but also of heart rate, could reflect abnormalities in the autonomic control of heart function.

Adult↗
PubMed1989

Microalbuminuria and casual and ambulatory blood pressure monitoring in normotensives and in patients with borderline and mild essential hypertension.

Several reports suggest that urinary albumin excretion may be elevated in patients with essential hypertension and that this index may be a good predictor for cardiovascular complications. The aim of this study was to compare 24-hour urinary albumin excretion in a group of normotensives, borderline, and untreated mild hypertertensives and to assess, in a subgroup of them, the possible relations between microalbuminuria and arterial blood pressure. Fifteen normotensives, 16 borderline, and 19 mild hypertensive patients were studied. Slightly but significantly higher values of microalbuminuria were observed in the mild hypertensives compared to the other two groups. In 21 borderline and mild hypertensive patients 24-hour microalbuminuria was related to casual blood pressure and noninvasive ambulatory blood pressure monitoring. A significant correlation was found between microalbuminuria and average day-time diastolic blood pressure. Our data suggest that albumin excretion is slightly increased in mild arterial essential hypertension; the direct association between microalbuminuria and arterial diastolic blood pressure during daily activities seems to confirm a pathophysiological link between transcapillary protein escape and arterial blood pressure that warrants further studies.

Adult↗
PubMed1989

Seasonal influences on blood pressure in high normal to mild hypertensive range.

To investigate the seasonal influences on various arterial blood pressure measurements, 22 subjects in the high normal to mild hypertensive range were examined twice following the same protocol. In one group (13 subjects), measurements were first done in warm conditions and repeated 5-7 months later in cold conditions; in the second group (nine subjects) a reverse sequence was followed. Blood pressure was measured under casual conditions during a hand grip exercise test, mental arithmetic test, and submaximal multistage bicycle exercise test; during the following 24 hours, blood pressure was measured serially with a noninvasive ambulatory blood pressure recorder. Daily outdoor maximum and indoor laboratory temperatures were also obtained. In the cold season, significantly higher values (on the average by 5-10 mm Hg, p less than 0.01) were obtained in both groups for mean diastolic daytime blood pressure. For other measurements, a trend toward higher values in the cold season was observed in both groups, although statistical significance was not obtained in all instances. For nighttime measurements, irrespective of the seasonal sequence, lower values were observed in the second session. Significant correlations were found between the differences in the average daytime ambulatory blood pressures and the corresponding changes of daily maximum outdoor temperatures after 5-7 months. These observations indicate that arterial blood pressure may be strongly influenced by environmental temperature. This phenomenon should be taken into account both in the evaluation of the individual hypertensive patients and in the design and analysis of studies on arterial hypertension, especially when ambulatory blood pressure techniques are employed.

Adolescent↗
PubMed1988

Cardiovascular reactivity to physical and psychologic stress during long-term treatment with nitrendipine in essential hypertension.

Nitrendipine is a second-generation dihydropyridine calcium antagonist selective for hypertension. The aim of this study was to assess whether, in addition to reduce resting blood pressure, nitrendipine also affects the cardiovascular reactivity to physical and psychologic stress. Ten essential hypertensive patients, out of treatment for at least 2 weeks, underwent a symptom-limited dynamic maximal exercise and a mental arithmetic stress test (MAT) after placebo (1 week) and 1 and 5 weeks of active treatment with nitrendipine (20 mg q.i.d.). To evaluate the cardiovascular response to exercise and its changes during treatment, the slope of the regression line (if statistically significant) of the blood pressure, heart rate, and rate-pressure product (RPP) values against workload were considered, together with exercise capacity, blood pressure, and pressure-rate product at the peak of maximal exercise. During mental stress, indexes of stroke volume (SVI), cardiac output (COI), and peripheral resistance (TPRI) were obtained by Doppler transcutaneous aortovelography (TAV). Resting systolic and diastolic BP were significantly reduced during treatment. The average length of exercise was 7.3, 7.64, and 8.0 min after, respectively, placebo, 1, and 5 weeks of treatment. Peak systolic and diastolic BP, peak RPP, and RPP slope were consistently decreased after treatment, significantly for peak DBP and RPP. During mental arithmetics, a significant increase of BP and HR and a decrease of SVI were observed on placebo; both BP and SVI responses disappeared after 5 weeks on nitrendipine, whereas the HR increase was unchanged. Peak values of COI and TPRI during MAT were significantly increased and decreased, respectively, after nitrendipine, whereas basal values showed similar changes, but not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Renal scintigraphic captopril test in the diagnosis of renovascular hypertension.

Angiotensin converting enzyme (ACE) inhibitor-induced renal failure has been reported in bilateral renal artery stenosis and in stenosis in solitary kidneys, but not in unilateral renal artery stenosis. In these patients, however, a functional impairment of the kidney ipsilateral to the stenosis can often be detected after ACE inhibition by scintigraphic techniques employing glomerular radionuclide tracers like 99mTc-diethylenetriamine pentaacetic acid (DTPA). Dynamic renal scintigraphy with 99mTc-DTPA before and 1 hour after administration of captopril, 25 mg (renal scintigraphic captopril test; RSCT), was performed in a selected series of 39 hypertensive subjects with suspected renovascular hypertension. Changes in glomerular filtration rate induced by captopril on the individual kidney were estimated by assessing the early (120-180 seconds) DTPA uptake by the kidney. Values were expressed as the ratio between the kidney with the lower uptake and the contralateral one in 34 patients and as the ratio of the kidney counts to the injected dose in five patients with solitary kidneys, aortic coarctation, or both. Compared with precaptopril values, postcaptopril uptake decreased markedly in 14 subjects (-62.42 +/- 30.94 [SD]%; range, -25 to -100%) and decreased modestly or even increased in the other 25 (+0.57 +/- 9.83%; range, +28 to -13%). Of the 14 subjects considered to be RSCT-positive diagnostic workup revealed either established (10) or strongly suspected (2) renal artery stenosis in 12 and aortic coarctation in 2 subjects. In another patient with established renovascular hypertension, results of the RSCT were negative when performed in the supine position but became positive when repeated in the sitting position.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Changes in renal function during physical and mental effort.

Aim of the study was to evaluate the renal responses to physical and mental effort in essential hypertension by means of a non-invasive radioisotopic method. Renal uptake rate of Tc99m-DMSA was evaluated in 10 subjects. Starting from 5 to 15 minutes after dose injection counts over the kidney region were acquired by means of a gamma-camera time-activity curves were obtained for each kidney. In non-stimulated patients DMSA uptake rate increased regularly; in the remaining cases both isometric exercise and mental effort induced an abrupt reduction of the uptake rate which increased again after the end of the test. Although the relation of DMSA uptake rate to renal function is not yet fully understood, we tentatively interpret these results as indicating blood flow reductions during these stressful conditions.

Humans↗