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Biomedical subjects

A Testa

Publications and source records attributed to A Testa.

At least 37 records · Page 2Linked to original sources
PubMed1990

Effect of protein A immunoadsorption on panel lymphocyte reactivity in hyperimmunized patients awaiting a kidney graft.

Six hyperimmunized patients awaiting a kidney graft underwent immunoadsorption of separated plasma through a protein-A column to remove HLA antibodies. This procedure was partially limited by constant and rapid antibody resynthesis in spite of strong immunosuppression with cyclophosphamide and prednisolone. Only two patients could be grafted with previously positive--currently negative crossmatches. The first died of infection on day 40, having developed early chronic vascular rejection and the other returned to hemodialysis on day 285 after the development of transplant glomerulopathy. However, immunoadsorption seems to be effective in removing HLA antibodies having a titer below 1/2. Such extremely hyperimmunized patients should probably be excluded from the immunoadsorption program.

Adult↗
PubMed1990

Torasemide, a new loop diuretic, in patients with chronic renal failure.

Torasemide, a new loop diuretic, was administered in 9 hospitalized patients with chronic renal failure to treat both arterial hypertension and peripheral edema. The urine of 5 patients was collected over 12-hour periods to assess the long-lasting diuretic activity of torasemide. Torasemide induced a significant decrease in blood pressure and reversion of peripheral edema in all patients without adverse effects. Torasemide is a high-ceiling loop diuretic, useful in correcting extracellular fluid volume expansion in patients with chronic renal failure.

Adult↗
PubMed1990

Randomised prospective study on renal effects of two different contrast media in humans: protective role of a calcium channel blocker.

Contrast media affect renal hemodynamics. Hyperosmolality is regarded as the major factor responsible for renal hemodynamic changes. In this study, the role of osmolality was evaluated in 30 hospitalized patients without risk factors during intravenous pyelography. Contrast media with low and high osmolality were used. In addition, nifedipine was administered before infusion of high-osmolality contrast to evaluate the role of calcium ions in radiocontrast-induced changes of renal hemodynamics. Hyperosmolar contrast reduced renal plasma flow and glomerular filtration rate. Calcium channel blocker prevented changes of renal hemodynamics. Hyperosmolality appears the most likely factor affecting renal hemodynamics during hyperosmolar radiocontrast infusion. Calcium channel blocker may prevent renal changes due to hyperosmolar medium.

Adult↗
PubMed1990

Anti-neutrophil cytoplasm antibodies in patients with monoclonal gammopathies.

Anti-neutrophil cytoplasm antibodies (ANCA) are specific markers for systemic vasculitis. In view of the autoreactivity to other autoantigens reported in patients with monoclonal immunoglobulins (MIg), the reactivity of 150 sera from 125 patients with MIg was tested for ANCA by radioimmunoassay (RIA) with inhibition stage and indirect immunofluorescence (IIF). Seven were positive for IgG ANCA, all with IgG MIg and 5 were positive for IgM ANCA, 4 with IgM MIg and 1 with IgG MIg. No IgA ANCA were found. The patterns seen on IIF were identical to those seen with sera from patients with systemic vasculitis and were cytoplasmic in 6 and peri-nuclear in 6. The restriction of the ANCA activity to the MIg was studied in six sera by light chain specific RIA, and anion exchange fractionation of the sera. The ANCA activity appeared to be polyclonal in at least three sera and could be found in the monoclonal fraction in only three patients. Associated autoimmune diseases were found in some of these ANCA positive patients including Sjögren's syndrome, MacDuffie hypocomplementemic vasculitis and rheumatoid polyarthritis but the classical vasculitic features normally associated with ANCA were not observed. We conclude that ANCA is a further autoreactivity present in some sera with MIg and discuss the relation between monoclonal gammopathies and autoimmunity.

Aged↗
PubMed1989

Acute cyclosporine renal dysfunction reversed by dopamine infusion in healthy subjects.

Up to now, no studies have been performed in normal humans to investigate the role of renal hemodynamic abnormalities in relation to acute-cyclosporin A (CsA) renal dysfunction and to verify whether the specific renal vasodilator, dopamine, can counteract these abnormalities. Eight normal subjects were examined both (A) after oral CsA (12 mg/kg body wt) and (B) after oral CsA + dopamine infusion (2 mg/kg body wt/min), under water diuresis. Both in protocols A and in B, four basal renal clearances were performed before CsA and every twenty minutes for four hours after CsA administration. In protocol A, after CsA, inulin (GFR) and PAH clearance (RPF) fell by up to 27% and to 41%, respectively, so that filtration fraction (FF) increased (P less than 0.01). A slight (not significant) hypertension occurred while renal resistances were markedly raised (P less than 0.001). Fractional urine and Na+ excretion as well as CH2O decreased, while UOsm increased (P less than 0.01). In protocol B, dopamine was infused from 120 to 180 minutes after CsA (that is, when the maximal adverse effects of CsA on renal hemodynamics had been observed in A). Dopamine infusion could reverse completely the effects of CsA on RPF, GFR, fractional urine output and CH2O; only UOsm remained higher than normal in conclusion with an increased fractional excretion of sodium (P less than 0.01). No changes were observed in plasma renin activity, aldosterone and in urinary epinephrine and norepinephrine excretion both in protocols.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Effects of uremia, acetate and bicarbonate dialysis on beta-adrenergic responsiveness as assessed by epinephrine-stimulated adenylate cyclase.

This study was designed to evaluate beta-adrenergic responsiveness as assessed by the generation of cyclic AMP after the subcutaneous administration of epinephrine in 31 subjects: normal controls, patients with chronic renal insufficiency, hemodynamically stable patients on chronic acetate dialysis and hemodynamically unstable patients with acetate intolerance on chronic bicarbonate dialysis. As compared with controls, only unstable patients on bicarbonate dialysis presented impaired beta-responsiveness, which, in turn, was acutely reduced only after acetate but not bicarbonate dialysis. Our results show that acetate dialysis impairs the beta-adrenergic responsiveness and that the observed beta-hyporesponsiveness in unstable patients with acetate intolerance may represent part of a broader spectrum of autonomic dysfunction which may develop in some patients on chronic hemodialysis.

Acetates↗
PubMed1989

Total or partial percutaneous renal ablation in the treatment of renovascular hypertension: radiological and clinical aspects.

In 15 patients with renovascular hypertension, considered unsuitable for angioplasty or surgery, percutaneous renal ablation was performed by injection of ethanol into the renal vasculature. Partial or complete renal ablation was confirmed by follow-up intravenous pyelography or arteriography. Patients were followed-up for a mean of 24.8 months after therapy and blood pressure was improved in all patients with five being cured. This study shows that percutaneous renal ablation is a useful and successful method of therapy for renal hypertension, and that it should be considered in patients unsuitable for surgery or angioplasty.

Adolescent↗
PubMed1989

[Magnetic resonance of the prostate: critical evaluation of diagnostic possibilities].

The authors retrospectively reviewed 140 MR examinations of the prostate to assess the presence of similar findings in the different patients affected with the same prostatic disease. In 35 patients with acute phlogosis, MR imaging showed enlargement of peripheral gland, with increased signal intensity on T2-weighted images, while reduced peripheral gland with low signal intensity was demonstrated in chronic phlogosis. Five patients presented roundish cystic lesions, with clear-cut outlines, clearly distinguishable from the surrounding parenchyma. Benign Prostatic Hyperplasia (BPH) was observed in 32 cases. 52% of them had multiple nodules with high signal intensity, 40% had hyperintense enlarged central glands, with no evidence of BPH nodules, and the remaining 8% presented single/multiple nodules with low signal intensity. In 56 patients with prostatic carcinoma the tumor extent ranged from 18-20 mm nodules to 5-6 cm masses with involvement of periprostatic adipose tissue or surrounding organs. The smallest lesions were always found in the peripheral gland and had low signal intensity on T2-weighted sequences. In spite of the different findings in the patients affected with BPH, the study proved MR imaging to be able to distinguish the various patterns of the different prostatic diseases.

Adolescent↗
PubMed1989

Diagnostic and therapeutic potential of new radiopharmaceutical agents in medullary thyroid carcinoma.

Recently developed radiopharmaceuticals have been proposed for imaging medullary thyroid carcinoma (MTC) with some having therapeutic potential. This study compares the imaging results obtained with radioiodinated meta-iodo-benzylguanidine (MIBG), 99mTc (V) DMSA, and 131I F(ab')2 anti-carcinoembryonic antigen (anti-CEA) in a group of MTC patients. In 23 patients 131I MIBG imaging showed a high specificity (no false-positive results) but a less satisfactory sensitivity (50%). In 12 patients 99mTc (V) DMSA revealed a better sensitivity (77%) but a lower specificity (three false-positive results). Positive results were obtained in two of three patients studied with 131I F(ab')2 anti-CEA. These data suggest that the highly sensitive 99mTc (V) DMSA should be considered as a first choice procedure followed by the highly specific radioiodinated MIBG to confirm the initial results. Since radioiodinated MIBG imaging may have therapeutic usefulness, 131I MIBG was evaluated in an integrated treatment protocol in four cases of proven MTC. The preliminary results obtained were encouraging.

3-Iodobenzylguanidine↗
PubMed1989

[MR characterization of breast pathology using inversion recovery sequence].

As yet, a valid tissue characterization of human breast diseases has not been possible with conventional MR techniques. On the basis of the experimental thesis according to which fibroadenomas and carcinomas have a slight, though significant, difference in T1 relaxation times, we employed specific inversion recovery sequences at the T null of the breast glandular and adipose tissues, to enhance the differences in the signal intensities of the various pathologies. We examined 16 (6 cystic dysplasias, 5 fibroadenomas, 3 carcinomas, and 1 phylloid fibroadenoma) selected patients with the above-mentioned sequences in addition to the routine T1- and T2-weighted spin echo sequences. The following conclusions were reached by evaluating the characteristic signal intensities: MR spin echo sequences allow solid lesions to be distinguished from cystic ones; MR inversion recovery sequences allow fibroadenomas to be distinguished from carcinomas with 88% accuracy.

Adenofibroma↗
PubMed1988

Induction of micronuclei in Vicia faba root tips treated with heavy metals (cadmium and chromium) in the presence of NTA.

Soluble metal compounds (CdCl2, K2Cr2O7) significantly increase the frequency of micronucleated cells in Vicia faba root tips with a clear dose-effect relationship. The addition of NTA (nitrilotriacetic acid) does not enhance the induction of micronucleated cells. Conversely, insoluble metal compounds (CdCO3, PbCRO4) significantly enhance the frequency of micronucleated cells only in the presence of NTA. Since some genotoxic metals are diffused in the environment and are often sequestered as insoluble precipitates in water sediments and sludges, the introduction of NTA is likely to increase the risk of environmental pollution because of its ability to solubilize and make those metals reactive.

Acetates↗
PubMed1988

Kinetics of the Hb A to Hb C switch and erythropoietin plasma levels in sheep.

The induction of Hb A (alpha 2 beta A2) and Hb C (alpha 2 beta C2) synthesis in three adult sheep has been sequentially analysed, in relation to the reduction of the haematocrit (Ht) and to the changes of erythropoietin (Epo) concentration in plasma. Hb A production is detected in peripheral reticulocytes when the Ht approaches 70% of its initial value in correspondence with the first rise of EPO plasma level, whereas HB C synthesis appears when the Ht is further reduced to about 50%, at an Epo concentration two to three times higher. The assumption that the cell committed to HB C synthesis is close to the erythroid colony-forming unit (CFU-e) progenitor is also discussed.

Anemia↗
PubMed1988

Treatment of severe renovascular hypertension by percutaneous transluminal renal angioplasty in patients with solitary functioning kidney. Effects on blood pressure and renal function.

In this study the effects of percutaneous transluminal renal angioplasty on blood pressure and renal function were studied in 9 hypertensive patients with stenosis of the main artery of a solitary functioning kidney. The outcome of the percutaneous dilatation of the renal artery stenosis, and the effects on blood pressure and renal function were evaluated for a mean period of 16.4 +/- 2.13 (SE) months (ranging from 3 to 65 months). A successful dilatation of the renal artery stenosis was shown in all the patients by the aortography performed 1 h after the procedure. At the discharge (7.8 +/- 0.9 days after dilatation), blood pressure was 'cured' in 2 patients and 'improved' in the remaining patients; renal function was improved in all patients who had reduced renal function. At the last follow-up, no restenosis was found in patients who repeated the follow-up angiography; blood pressure was 'cured' in 3 patients and 'improved' in 6 patients, and renal function appeared steadly improved. In contrast with other reports, our results demonstrate that percutaneous renal angioplasty is a safe and effective procedure and should be attempted before considering surgical intervention in patients with artery stenosis of a solitary functioning kidney.

Adult↗
PubMed1988

Treatment of massive hemorrhage after renal biopsy with percutaneous arterial obliteration.

Severe perirenal hemorrhage is a major, although rare, postbiopsy complication. We report a case of a 48-year-old man with a postbiopsy massive bleeding from a ramification of the renal artery supplying the lower pole of the left kidney. Treatment consisted of complete obliteration of the bleeding vessel by helding a percutaneous catether in wedge position during a renal arteriographyc study. Our case shows that percutaneous arterial obliteration is a successful procedure in treating postbiopsy renal hemorrhage, representing an effective alternative to surgical therapy.

Biopsy, Needle↗
PubMed1988

[Magnetic resonance of the breast. Clinical experience with a dedicated coil].

MR Imaging was performed on 10 healthy volunteers and 86 patients, using a 0.5 T superconducting magnet and a dedicated coil to image both breasts simultaneously. The patients were selected by the presence of nodules at clinical examination. Final diagnoses were made either at histology--in the patients who underwent surgery--or at cytology, with fine needle biopsy. The MR findings of the different breast diseases are discussed. In spite of an improved spatial resolution and of a very good natural contrast between different tissues, MR Imaging does not allow a satisfactory characterization of the lesions; its use is thus limited to the staging of cancers which need a better therapeutic planning.

Adenofibroma↗