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Biomedical subjects

L Orte

Publications and source records attributed to L Orte.

At least 19 recordsLinked to original sources
PubMed2001

Renovascular hypertension in children.

OBJECTIVE: To study the etiology, clinical spectrum. image findings, management and outcome of children with renovascular hypertension (RVH). MATERIAL AND METHODS: Twenty children (aged 5 days to 15 years) were studied and treated for RVH during 1977-1998. In 14 cases hypertension was found during a routine examination. Six cases had heart failure and/or hypertensive encephalopathy. Diagnosis was made with aortography. Post-captopril renography and Doppler ultrasonography were obtained in 8 patients and spiral computed tomography angiography in 2. Treatment consisted of surgery (8 patients), percutaneous transluminal angioplasty (PTA) (5) or antihypertensive drugs only (8). RESULTS: Initial blood pressure was 62 +/- 31 mmHg > 95th percentile for systolic and 44 +/- 22 mmHg for diastolic blood pressure. Twelve children had unilateral and 8 had bilateral arterial stenosis. In 3 cases lesions were intrarenal. RVH was due to fibromuscular dysplasia (7 patients) and associated to middle aortic syndrome (5). neurofibromatosis (3), William's syndrome (2). Takayasu's arteritis (1) and pheochromocytoma (1). Treatment of choice was decided depending on the size of the child and location and severity of the stenosis. At the end of the follow-up (78 +/- 49 months), 9 patients are normotensive without medication and 7 are normotensive with drugs. Three patients have died, 2 for unrelated causes and I for cardiac failure; 1 child was lost to the follow-up. CONCLUSIONS: Although symptoms are relatively uncommon. renovascular disease is a frequent cause of severe hypertension in childhood. Non-invasive diagnostic techniques appear useful as screening methods. Treatment by surgery or PTA is successful if patients are carefully selected.

Adolescent↗
PubMed2001

Clinical characteristics of ischaemic renal disease.

BACKGROUND: Longer life expectancy has favoured the ever more frequent development of ischaemic nephropathy characterized by the presence of atherosclerotic stenosis in both renal arteries. METHODS: This is an observational and multicentre study carried out during a 14-month follow-up period in 20 hospitals in SPAIN: Inclusion criteria were the presence of bilateral renal artery stenosis > 50% and a creatinine level of > or = 1.5 mg/dl. The diagnosis should be made by arterial digital angiography in every case. RESULTS: A total of 156 patients were included. Their mean age was 68.7+/-9 years, and 78.5% were male. The mean creatinine value of the group was 2.9+/-1.7 mg/dl. Arterial hypertension (BP) with a duration of 12+/-9 years was present in 97.4% of the cases, smoking habits in 69.8%, hypercholesterolaemia (> or = 240 mg/dl) in 62.9% and diabetes in 32.1%. Only 8% of the patients had a body mass index > or = 30 kg/m(2). Associated cardiovascular disease was very frequent: peripheral arteriopathy in 67.5% of the cases, ischaemic cardiopathy in 44.8%, cardiac insufficiency in 32.6% and stroke in 27.3%. In 94.4% of the patients, the lesion affected both renal arteries, with complete obstruction in 23% of the cases. CONCLUSIONS: Diagnostic suspicion of ischaemic nephropathy can be established in non-obese elderly males with chronic renal insufficiency, long-term BP evolution and cardiovascular disease at other levels, above all, peripheral arteriopathy.

Aged↗
PubMed2000

Antiproteinuric effect of calcium antagonists on puromycin-induced experimental nephrosis.

Calcium antagonists have a potential for beneficial effects on kidney function unrelated to their antihypertensive action. In this study we have investigated the efficacy of calcium antagonists compounds (verapamil, nifedipine and diltiazem) on reversible acute renal insufficiency, proteinuria and interstitial nephritis induced by the puromycin ammonucleoside (PAN). An increase in blood pressure (BP) was detected on day 14, with no statistical differences in the response to calcium antagonists. Serum creatinine concentration increased to 1.2 mg/dL on day 7 after PAN and decreased to 0.7 mg/dL at 14 days, calcium antagonists shortened the time required to reach baseline or control levels. Calcium antagonists also reduced proteinuria in the PAN-treated animals, in both day 7 and day 14. Differential effects of the antagonists were observed. Verapamil caused a greater reduction (p < 0.01) in proteinuria than nifedipine or diltiazem in day 7. Moreover, verapamil (p < 0.01) and nifedipine (p < 0.01) reduced the total number of interstitial infiltrating leukocytes from 690 to 120 and 425 positive cells/20 high power fields (x63) respectively, by contrast, diltiazem had no effect. We conclude that in this model of PAN nephropathy verapamil is more effective in reducing both proteinuria and the severity of acute interstitial nephritis than either nifedipine or diltiazem. The possible clinical implications of these results remain to be elucidated.

Animals↗
PubMed1999

Fibroblast growth factor protects the kidney against ischemia-reperfusion injury.

Ischemia-reperfusion injury, a common source of renal dysfunction in adults, is associated with tubular epithelial cell damage. Since fibroblast growth factors (FGF) attenuated tissue injury after transient myocardial ischemia, we hypothesized that acidic fibroblast growth factor (aFGF; FGF-1) would attenuate renal ischemia-reperfusion injury. We studied the effects of FGF-1 in a rat model of acute renal failure induced by bilateral renal ischemia (60 min) and 1, 2 or 7 days reperfusion. After FGF-1 administration at the onset of renal reperfusion, there was less functional impairment of the kidneys. The histological changes were not as severe as in controls. Increases in serum creatinine and blood urea nitrogen 24 h after reperfusion were attenuated by 35% (p< 0.01) and by 53% (p< 0.001), respectively, in FGF-1-treated animals compared to vehicle-treated rats. The ischemia/reperfusion-induced increase in tissue myeloperoxidase, a marker of neutrophil infiltration, was mitigated (67% reduction, p< 0.05) with FGF-1 treatment. As shown by histology, neutrophil infiltration and tubular cell necrosis in medulla were less pronounced (p< 0.0001 and p< 0.05, respectively) in animals receiving FGF-1. Furthermore, ischemia-induced apoptosis, prevalent in tubular cells of the cortex, was also attenuated by FGF-1-treatment (83% reduction, p< 0.0001). Pretreatment of animals with Nw-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide synthase, abolished the attenuating effects of FGF-1 on neutrophil infiltration, suggesting that nitric oxide might participate in the anti-inflammatory effects of FGF-1 in this experimental design. Our data support a role for FGF-1 in attenuation of renal damage or failure after ischemia-reperfusion injury of the kidney, in part at least by inhibition of neutrophil infiltration.

Animals↗
PubMed1997

Malignant pheochromocytoma, still a therapeutic challenge.

For cases of malignant pheochromocytoma the prognosis is poor and experience with its treatment remains limited. We present a case of a hypertensive 16 year old woman with malignant pheochromocytoma and a good treatment response. Bone metastases appeared 6 months after the first resection. Local excision of the thoracic vertebrae metastases and palliative radiation therapy were performed, after which she received twelve cycles of cyclophosphamide, vincristine, and dacarbazine. Sixteen months later the patient remains asymptomatic without biochemical catecholamine activity.

Adolescent↗
PubMed1996

Influence of hypertension on early renal insufficiency in autosomal dominant polycystic kidney disease.

To determine the potential effect of hypertension on early renal function deterioration, 30 patients (13 normotensive and 17 hypertensive) with autosomal dominant polycystic kidney disease and initially normal renal function were retrospectively analyzed. The decline in renal function was estimated by the slope of the linear regression of creatinine clearance versus time. Analysis was made in terms of standardized slope (slope divided by its standard deviation, i.e., measured in standard deviation units). In the hypertensive group the mean standardized slope was significantly higher than in the normotensive group (-10.89 and -4.98, respectively; p < 0.001). The average mean arterial pressure was significantly lower in the normotensive group with respect to the hypertensive one (95 and 109 mm Hg, respectively; p < 0.0001). There was a significant negative linear relationship between the average values of systolic, diastolic, and mean arterial pressures and standardized slopes. The best prediction equation for renal function deterioration was obtained using a multiple linear regression model in which independent variables were maximum and average diastolic pressures. Therefore, prior to renal insufficiency, a high arterial pressure had a significant contribution to renal function deterioration.

Adult↗
PubMed1996

Urinary calcium excretion in treated and untreated essential hypertension.

A high prevalence of hypercalciuria has been reported in patients with essential hypertension. Nevertheless, the clinical and therapeutic implications of this finding have scarcely been studied. This study was designed to determine the prevalence of hypercalciuria in an unselected population with essential hypertension and to analyze the relationship between the urinary calcium and the clinical and therapeutic status of these patients. This article presents a prospective study of 112 patients with essential hypertension and 49 healthy normotensive control subjects. Urinary excretion rates of calcium, sodium, chloride, potassium, urinary calcium/creatinine index, the fractional excretion of sodium, potassium and uric acid, the creatinine clearance and serum values of creatinine, urea, uric acid, electrolytes, total proteins, parathormone (intact molecule), plasma renin activity, aldosterone, glucose, and insulin (fasting and after an oral glucose load) were performed in every patient and control subject. Untreated hypertensive patients had a higher prevalence of hypercalciuria (35% had a urinary calcium/creatinine ratio > 0.20 versus 20% of treated hypertensives and 2% of control subjects; P < 0.001). Patients on thiazide or beta-blocker monotherapy had lower urinary excretion rates of calcium and urate than patients on calcium-antagonist monotherapy or untreated patients. Urinary calcium, sodium, and urate correlated positively both in treated and untreated essential hypertension patients. Patients with the higher urinary calcium levels also had higher excretion rates of sodium and urate, higher creatinine clearance rates, and lower serum creatinine and serum uric acid levels. It was concluded that hypercalciuria is a frequent finding of untreated essential hypertension. The association of high urinary calcium levels with high urinary urate excretion rates in the same patient may predispose to development of lithiasis in patients with essential hypertension. Antihypertensive drugs have a variable effect on calciuria-uricosuria, which may constitute an additional criterion in the selection and individualization of therapy. Thiazides and beta-blockers can decrease calciuria and uricosuria and, therefore, the lithogenic risk in these patients.

Adrenergic beta-Antagonists↗
PubMed1994

Prevalence of antiphospholipid antibodies in nephropathies not due to systemic lupus erythematosus.

Renal involvement by some types of thrombotic microangiopathy has been associated with the presence of antiphospholipid antibodies in both patients with systemic lupus erythematosus (SLE) and in those with other types of connective tissue disorders. To assess the prevalence and clinical significance of these antibodies in renal disease we prospectively studied anticardiolipin antibodies and lupus anticoagulant activity in 138 patients. These patients were classified into four groups: chronic glomerulonephritis (n = 57), acute and non-SLE systemic nephropathies (n = 13), non-immune-related nephropathies (n = 39), and SLE nephropathies (n = 29). The prevalence of antiphospholipid antibodies in patients with chronic primary glomerulonephritis (9%) was lower than in the SLE group (34%) and higher, but not significantly, than in patients with non-immunologically mediated renal diseases (2.6%). Positive patients in this group correspond to atypical "lupus-like" SLE forms or sporadic cases. In the group of patients with acute nephropathy and non-SLE systemic disorders, lupus anticoagulant was present in sic and anticardiolipin was present in four. In most cases the finding was transient and probably related to concomitant infection or active immune response. We conclude that there is a low prevalence of antiphospholipid antibodies in primary chronic glomerulonephritides, similar to that found in non-immunologically based nephropathies. The presence of these antibodies associated with chronic glomerulonephritis should raise the suspicion of SLE. On the other hand, positivity of these antibodies is a frequent finding in acute and systemic nephropathies. Therefore, the clinical and prognostic significance of their presence in these disorders should be further studied in a larger series of patients.

Adolescent↗
PubMed1994

Use of urinary parameters in the diagnosis of total acute renal artery occlusion.

Limited attention has been paid to the composition of the small amounts of urine that are frequently produced by patients with acute renal failure (ARF) of vascular origin. We have investigated the value of basic urinary parameters in the early diagnosis of total or partial acute renal artery occlusion (ARAO). We have reviewed the records of 30 patients with ARF: group 1 (n = 10) had total ARAO; group 2 (n = 10) had unilateral ARAO with a contralateral functioning kidney, and group 3 (n = 10) had hemodynamically mediated ARF subsequent to a major vascular abdominal surgical procedure, without arterial thrombosis. Serum sodium, potassium, urea, creatinine and osmolality, as well as urinary sodium, potassium, urea, creatinine and osmolality, were determined by standard techniques, and the fractional excretion of sodium (FENa) was calculated. Serum parameters were similar in all groups. Urinary sodium and FENa were higher in group 1 than in the other groups (p < 0.01), while urinary potassium was lower (p < 0.05). Urinary urea (p < 0.01) and osmolality (p < 0.05) were higher in group 2 than in the other groups, revealing a prerenal pattern in some cases. Serum and urinary concentrations of sodium, urea and creatinine and osmolality were similar in group 1, while respective serum and urinary concentrations and osmolality were different from each other in the other groups. Analysis of urine provides a useful diagnostic tool in ARF of vascular origin. When urinary concentrations of sodium, urea and creatinine are similar to those in serum and FENa approaches 100%, the strong likelihood of total ARAO should be acknowledged, and renal arteriography is mandatory.

Acute Kidney Injury↗