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Biomedical subjects

R Rivolta

Publications and source records attributed to R Rivolta.

At least 37 records · Page 2Linked to original sources
PubMed1996

Renal vascular damage in systemic sclerosis patients without clinical evidence of nephropathy.

OBJECTIVE: To evaluate the use of color-flow Doppler ultrasonography, a direct, noninvasive technique, for measurement of kidney blood flow in patients with systemic sclerosis (SSc). METHODS: Twenty-five normal volunteers and 25 SSc patients (median disease duration 8 years, range 2-21 years) were studied. All were free of clinical symptoms of renal damage. The resistance index (RI) was determined on main, interlobar, and cortical vessels. RESULTS: In SSc patients, the RI was significantly increased at every sampling site examined (P < 0.001). RI values were strongly correlated with disease duration (main artery r = 0.56, P < 0.04; interlobar artery r = 0.63, P < 0.02; cortical artery r = 0.75, P < 0.002). Regression analysis showed no relationship between RI and creatinine clearance values. CONCLUSION: Color-flow Doppler ultrasonography is a sensitive and noninvasive technique for evaluating vascular damage of the kidney in patients with SSc.

Adult↗
PubMed1996

Relevance of resistive index ultrasonographic measurement in renal transplantation.

The usefulness of the ultrasonographic measurement of resistive index (RI) is not yet fully understood. To obtain a better definition of its relevance in renal disease we studied this parameter in a group of 212 renal transplant patients, aged between 15 and 55 years: 81 first grafts with an excellent renal function, 44 hypertensive patients, 30 type II diabetics, 29 cases of chronic graft dysfunction, 28 cases during an episode of acute rejection. RI was measured in three different renal vascular areas: prerenal, interlobar and cortical. A two-way analysis of variance showed a statistical significance for the site of RI sampling and the type of pathology. There was no interaction between the two variables studied (p = 0.30). Plasma creatinine levels, analyzed as covariate, showed a high statistical correlation with RI values (p = 0.0001). The mean RI of the 80 transplanted patients with normal creatinine plasma levels showed a remarkable homogeneity and a statistically significant progressive reduction of the values from the main renal artery to the interlobar and cortical vessels (p = 0.00001). In the other groups a greater dispersion of data was present. RI values significantly increased in hypertensive and diabetic patients (p = 0.05) but more in acute rejection (p = 0.0001) or chronic graft dysfunction (p = 0.01). In acute rejection and in chronic graft dysfunction the curve of RI values tended to become flat, while in hypertensive and diabetic patients the aspect of the curve became steeper. In conclusion, RI is a hemodynamic index that reflects the vascular status of the explored area and is not only the simple expression of reduction of the kidney functional units. The differences observed in the various kidney areas stress the importance of measuring this parameter at more than one vascular site. The increase in RI values on the kidney cortex vessels is likely to be an index of glomerular hyperfiltration. If this hypothesis is true the measure of RI might be a reliable method for diagnosing in the kidney vascular damage, glomerular hypertension and hypertrophy.

Adolescent↗
PubMed1996

Color Doppler sonography in Graves' disease: value in assessing activity of disease and predicting outcome.

OBJECTIVE: The aims of the study were to establish the usefulness of color Doppler sonography in assessing changes in thyroid blood flow during the course of Graves' disease and to investigate which of several variables (thyroid volume, number of intraparenchymal vessels, and blood flow in the thyroid artery) were best related to thyroid hyperfunction and therefore could be used to evaluate the course of the disease. SUBJECTS AND METHODS: Fifty-six patients with Graves' disease were selected and divided on the basis of clinical and laboratory data into four groups: patients untreated at first diagnosis, patients undergoing antithyroid drug treatment, patients in remission after withdrawal of therapy, and patients having a relapse of hyperthyroidism. Ten healthy subjects served as controls. RESULTS: Patients with active hyperthyroidism (at first diagnosis, during treatment, or at relapse) had a significantly enlarged thyroid (p = .005); intrathyroid vascularization, evaluated as number of vessels per square centimeter (p < .0001); and blood flow in the thyroid artery (p < .0001) compared with control subjects and with patients in remission after withdrawal of therapy. During treatment, sonographic values were slightly lower but not significantly different from those registered in patients at the onset of hyperthyroidism, indicating that normalization of vascularity does not parallel the drug-induced decrease of hormonal synthesis. Among 21 patients in remission, the nine patients who had a relapse shortly after the examination had a higher number of vessels per square centimeter (2.18 +/- 0.34 versus 1.03 +/- 0.16, p = .03) and higher flow in the thyroid artery (80.3 +/- 19.1 versus 10.6 +/- 2.3 ml/min, p = .01) than did the other 12 patients who remained in stable remission, despite normal hormonal levels in both groups. CONCLUSION: Our results suggest that color Doppler sonography can be used to assess activity of Graves' disease and to predict the outcome of the disease after withdrawal of medical therapy.

Adult↗
PubMed1995

Resolution of hyperthyroidism in a pregnant woman with toxic thyroid nodule by percutaneous ethanol injection.

Overt hyperthyroidism was found in a 35-year-old pregnant woman at the 13th week of gestation who was referred to us for tachycardia, tremors, and weight loss. Clinical signs, symptoms, and laboratory findings led to the diagnosis of toxic thyroid nodule. She was treated with ultrasound guided percutaneous ethanol injection (PEI) and, after 2 weeks of treatment, the woman was completely euthyroid. These findings suggest that during pregnancy PEI appears to be a rapid and safe therapy for toxic nodular goiter and an effective alternative to the administration of antithyroid drugs.

Administration, Cutaneous↗
PubMed1995

The well-functioning renal graft evaluated by color Doppler flowmetry.

The value of color Doppler ultrasound in the renal transplant follow-up has been evaluated. To do so we used a standardized protocol of analysis on a group of 86 outpatients with different transplant ages and a good and stable graft function defined as a plasma creatinine level < 105 microM/l. Renal volume increased after transplantation and averaged 198 +/- 54 cm3. The graft volume was positively related to the transplant age (p = 0.04). Mean renal blood flow/1.73 m2 body surface area was 301 +/- 98 ml/min, a value at the lower limit of normality. A statistical inverse relationship between renal blood flow and transplant age was found (p = 0.04). Renal vascular resistances increased along with the transplant age (p = 0.003). Renal function evaluated by creatinine plasma levels and creatinine clearance values did not show any statistical correlation with color Doppler findings in normal grafts. In conclusion, ultrasound measures allow us to obtain more sensitive information about the graft status and might be used for a better evaluation of the transplant follow-up.

Adult↗
PubMed1995

[Color Doppler ultrasonography in the diagnosis of solid breast lesions].

The color-Doppler signals in 50 patients with breast lumps were assessed subjectively. Number and location of vessels within the masses were recorded and compared with histologic diagnosis and lesion size. All the malignancies were vascularized but only 16/37 of the benign ones showed vessels. All malignancies but one displayed > or = 2 vessels, which on the other hand occurred in only 4/16 vascularized benignancies. There was a relation between size of the lesion and number of the observed vessels, and color-Doppler proved more reliable in the differential diagnosis of breast masses when lesions less than 2 cm were considered.

Adolescent↗
PubMed1994

[Colorectal cancer in the young adult: comments on a sample of 33 patients operated on with the goal to cure].

A retrospective study of the overall cases operated for colorectal cancer is reported. Subgroups of patients comparable for staging and grading, over 45 years of age and younger than 45 years, radically operated from January 1984 to June 1989, were analyzed in order to evaluate survival and prognosis in younger subjects. A favourable trend in relation to three-year prognosis was registered in younger patients (73% vs. 65%).

Adenocarcinoma↗
PubMed1993

Distribution of GAP-43 mRNA in the adult rat brain.

Regional distribution of gene expression of the axonal growth-associated protein, GAP-43, was studied in adult rat brains by in situ hybridization autoradiography to determine the features of mature neuronal populations that synthesize GAP-43 protein. Such synthesis appears to correlate with axonal growth during maturation and regrowth after axotomy. In most adult neurons, the sharp decline in GAP-43 gene expression implies a reduced capacity for axonal growth. Neurons capable of extending axonal knobs in the absence of injury may indicate a "plasticity" underlying dynamic processes of interaction between neurons and their synaptic targets. Antisense and sense (control) riboprobes were used on serial sections in the three principal axes, and the magnitude of hybridization signal was examined to determine regional patterns. GAP-43 mRNA levels are pronounced in diverse neuronal groups including the locus coeruleus, raphé nn., dopaminergic nigral and ventral tegmental nn., mitral cells, hippocampal CA3, inferior olivary n., vagal motor n. and other parasympathetic preganglionic neurons, select thalamic midline and intralaminar nn., several specific nn. of the hypothalamus and basal forebrain, the granular layer of cerebellar cortex, the infragranular neocortex, and the granular olfactory paleocortex; there is a substantial range in the magnitude of expression. Regions revealing minimal signal include most thalamic sensory relay nuclei, the granule neurons of the olfactory bulb and dentate gyrus, and the caudate and putamen. Possible concomitants of GAP-43 expression include regulation of ion flux and neurotransmitter release. Those neurons with long, extensively dispersed and numerous synaptic connections display the strongest signals and may possess the greatest propensity for continuous growth and turnover of their axon terminals, in contrast to short-axon and specific projection neurons exhibiting minimal levels. These data may enable inferring which populations display normal or experimentally induced axonal growth.

Animals↗
PubMed1993

Effect of cyclosporin A on renal cortical resistances measured by color Doppler flowmetry on renal grafts.

Doppler spectra were recorded at different cyclosporin A (CSA) levels (trough and peak) in 30 stable renal-transplanted outpatients: 15 with unimpaired renal function (plasma creatinine < 150 mumol/l) and 15 with renal impairment (plasma creatinine 150-350 mumol/l). Pulsatility (PI) and resistive indexes (RI) have been measured in the renal artery at the hilum and in the renal cortex. RI and PI were markedly increased (p < 0.0001) in the cortex at peak time while in the renal artery no significant changes were observed. These variations were statistically related with CSA blood levels (PI = p < 0.02; r = 0.54, RI = p < 0.05; r = 0.45). These effects were also found in the presence of renal damage. CSA dose-dependently reduces cortical blood flow, causing a persistent arteriolar vasoconstriction and a reduction in diastolic flow. This effect can be measured in man in a noninvasive and repeatable way using color Doppler sonograms.

Adult↗
PubMed1993

Nasal formulations of ketorolac tromethamine: technological evaluation--bioavailability and tolerability in rabbits.

This paper describes the development of a novel formulation of the powerful non narcotic analgesic ketorolac tromethamine. This drug is given orally three to four times/day to deliver a total of 30 to 60 mg of drug. Higher doses cannot be given orally because of gastrointestinal side effects and intramuscular injections, three times/day must then be used. The need for injections limits the drug to a clinical setting. Nasal delivery offers a method of achieving the high blood levels of repeated intramuscular injections in a formulation that can be easily applied by the patients. Four formulations were evaluated in "in vitro" and "in vivo" rabbit tests. The best formulation consisted of a 5% solution of ketorolac tromethamine containing 0.3% sodium glycocolate as a known mucosal drug absorption enhancer. Ketorolac applied in this way had a bioavailability greater than 80%. The controlled release nature of nasal delivery also doubled the drug's apparent half life. The drug formulation was stable in three-months stability tests and produced minimal nasal irritation.

Administration, Intranasal↗
PubMed1993

[Color-Doppler semiology in transplanted kidney].

Color-encoded duplex ultrasonography (CEDU) makes a more accurate technique in kidney graft monitoring by combining real-time US with pulsed Doppler studies of renal vasculature. It is a non-invasive and easy technique. Suitable to study the whole renal artery and vein, CEDU also allows the qualitative and quantitative assessment of the intrarenal vasculature and therefore the easy diagnosis of such vessel dysfunctions as arteriovenous fistulas following biopsy. Moreover, Doppler spectral analysis can be used to distinguish among different causes of renal allograft dysfunction--i.e. rejection, cyclosporine nephrotoxicity or acute tubular necrosis. The value of the resistive index for the differential diagnosis is discussed. CEDU allows a more reliable measurement of renal blood flow thanks to the more precise evaluation of renal artery diameter and mean flow velocity.

Blood Flow Velocity↗
PubMed1993

[Role of echo-color Doppler in the monitoring of the transplanted kidney].

Renal allografts are subject to many vascular complications. Doppler US is a non-invasive technique that can evaluate many of the potential complications related to renal allografts, such as rejection, cyclosporine toxicity, acute tubular necrosis, renal artery stenosis, renal vein thrombosis. Changes in the resistive index (RI), which accurately reflects renal vascular impedance, have been employed in the evaluation of renal allograft dysfunction. A review of the literature shows conflicting results with values of sensitivity and specificity ranging from 0.96 and 0.97 to 0.46 and 0.80, respectively. It seems that an increase in the RI is a nonspecific sign in determining the underlying abnormality due to the unique features of the vascular bed of each allograft which results in poor correlative values for single isolated measurements of RI. Serial studies, employing a baseline value, can be useful in the follow-up of graft dysfunction.

Color↗
PubMed1992

Cyclosporine renal cortical vasoconstriction measured by colour Doppler imaging in kidney transplantation.

Important side-effects limit the use of cyclosporine A (CSA), the most insidious of which is nephrotoxicity, which manifests as a preglomerular arteriolar vasoconstriction causing a reduction in glomerular filtration rate (GFR) and renal plasma flow (RPF). This condition is initially purely functional, but with time can become anatomic and irreversible. In clinical practice we lack suitable methods for evaluating CSA vasoconstriction. Our present knowledge is based on indirect information obtained from repeated measurerments of plasma creatinine levels and from blood concentrations of the drug. Sometimes more complex and non-routine tests, such as the evaluation of GFR and RPF, or invasive methods, such as renal biopsy, are also employed. In this study we used the colour-Doppler technique to measure directly the vascular effects of CSA in patients with transplanted kidneys, evaluating changes in blood flow at the hilus and on the cortex of the kidney when the drug was at trough or peak levels.

Adult↗