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Biomedical subjects

A Barrientos

Publications and source records attributed to A Barrientos.

At least 127 records · Page 7Linked to original sources

Clinical implications of the presence of refractile particles in the liver of haemodialysis patients.

In a retrospective study we have examined 20 liver specimens from haemodialysis patients with a mean time on treatment of 27 months. Thirteen specimens were biopsies, the remaining came from autopsies. The presence of refractile particles was found in 55 per cent of biopsies and 100 per cent of autopsies. Its presence was not constantly associated with morphological lesions of the liver. We believe that the deposition of this material could be a fortuitous finding with uncertain clinical implications.

Adult↗

Role of renal prostaglandin E2 in chronic renal disease hypertension.

The role played by renal prostaglandin E2 in the maintenance of hypertension in chronic renal disease has been investigated through studying the response of body weight, blood pressure, glomerular filtration rate (GFR), 24-hour natriuresis, plasma renin activity (PRA), plasma aldosterone and urinary PGE2 excretion to the administration of indomethacin (2mg/kg daily, during 3 days). A group of 37 patients diagnosed as having chronic renal parenchymatous disease with creatinine clearance above 25 ml/min was included in the study. 21 of them were hypertensive (BP greater than 160/95). 27 normotensive volunteers were also studied and considered as the control group. The initial study disclosed similar levels of PGE2, PRA and plasma aldosterone in volunteers, normotensive patients and hypertensive patients, although the sodium intake was lower in the last two groups. A positive correlation between PRA and urinary PGE2 was found both in normotensive (r = 0.507, p less than 0.01) and in hypertensive patients (r = 0.609, p less than 0.01). The administration of indomethacin induced a diminution of PRA, plasma aldosterone and urinary PGE2 levels together with an increase in diastolic blood pressure (p less than 0.05-0.01) in both volunteers and patients. The remaining parameters measured did not change in volunteers or in normotensive patients. On the contrary, in hypertensive patients, during indomethacin administration, lower values of creatinine clearance (p less than 0.005) and 24-hour natriuresis (p less than 0.05) together with an increase in body weight (p less than 0.01) were observed. These results point to the existence of a protective role of renal prostaglandin E2 upon renal function when hypertension appears in the course of chronic renal parenchymatous disease.

Adolescent↗

The role of urinary PGE2 and renin-angiotensin-aldosterone system in the pathogenesis of essential hypertension.

In a group of 26 patients diagnosed as essential hypertensive (EH) and in a control group (CG) of 27 normotensive volunteers the urinary excretion of PGE2, plasma renin activity (PRA) and plasma aldosterone were measured. EH patients were classified into normoreninemic (NREH) (n = 21) and hyporeninemic (LREH) (n = 5) by the response of PRA to the combined stimuli of ambulation and furosemide. Urinary PGE2 excretion was higher in NREH than in CG (p less than 0.05) while LREH showed values lower than in CG (p less than 0.001). Plasma aldosterone levels were similar in the three groups. In CG and EH patients PRA and urinary PGE2 were closely related (CG r = 0.516, p less than 0.05, EH patients r = 0.674, p less than 0.001). Indomethacin administration induced a decrease of PGE2 in both CG (n = 8) and NREH (n = 8) (p less than 0.01). In contrast, indomethacin induced no changes in PGE2 excretion of LREH (n = 5). Furthermore in the group of patients with NREH indomethacin induced a significant increase in blood pressure (p less than 0.01) and body weight (p less than 0.01) while glomerular filtration rate, 24 hour natriuresis PRA and plasma aldosterone decreased (p less than 0.01). On the contrary, in LREH indomethacin did not alter any of the parameters measured. These results indicate that LREH and NREH may be regarded as two different populations distinguishable not only by different secretion of PRA but also by different excretion of PGE2 in urine and by their characteristic response to indomethacin.

Adult↗

Role of the control of phosphate in the progression of chronic renal failure.

In order to control the progression of chronic renal failure through the maintenance of low-normal levels of serum phosphate, 10 patients (group I) were followed over a period of 10 months. They were maintained on a low phosphate diet and 12 g/day of aluminum hydroxide. Under this treatment, the serum phosphate decreased significantly compared to the phosphate levels determined prior to initiation of treatment, and compared to the serum phosphate levels of 10 controls with the same degree of renal failure (group II) but receiving conventional treatment. Despite the maintenance of normal levels of serum phosphate in group I, serum creatinine increased in the same proportion as in group II. A paired t test did not show any difference between the progression of the renal failure before or after the control of serum phosphate.

Aluminum Hydroxide↗

[Hypertensive crisis. Clinical and therapeutic study of 130 cases (author's transl)].

The clinical aspects and response to therapy of 130 hypertensive emergencies are reviewed in this report. According to the main features of the clinical picture, the patients were divided into neurologic, cardiac or mixed emergencies. The patients were evaluated with clinical examination, fundoscopy, routine biochemistry, ECG, and chest radiograms. According to the response of the blood pressure to the administration of hypotensive drugs, the patients were divided into two groups: group I, with good response to a single drug associated to frusemide, and group II, with good response to two or more drugs associated to frusemide. Neurologic emergencies appeared in 55 patients (42% of total), and cardiac emergencies in 45 (34%), the initial blood pressure beeing higher in the first group (p less than 0.005). The fundus showed hypertensive retinopathy degrees III-IV in 55% of the patients. Patients in group I had less elevation of the initial blood pressure, showed a better response to therapy, and had only mild side effects from the administered drugs. Group II had a mortality of 11% and, as expected, showed more complications due to side effects. The frequency of appearance of toxic side effects from the drugs given is reviewed, and a therapeutic schedule is proposed.

Antihypertensive Agents↗

The value of ultrasonic scanning in the differentiation of acute post-transplant renal failure.

In 43 renal transplant patients studied by ultrasonography there were 32 episodes of acute rejection and 17 of acute tubular necrosis. The size of the kidney increased in all cases. However, in 75 per cent of the patients with acute rejection the central echoes of the renal sinus increased conspicuously, while in 77 per cent of those with acute tubular necrosis the echogenicity of the central sinusal complex decreased. These findings may be expressions of different pathological lesions at the renal sinus level in patients with acute rejection and acute tubular necrosis, which would modify the acoustic interphase. Therefore, we have found panniculitis, vasculitis, thrombosis and inflammatory cellular infiltration of the urinary collecting systems to be significant in patients with acute rejection but not in those with acute tubular necrosis. Ultrasonography can be an adjuvant instrument for the sometimes difficult differential diagnosis between acute tubular necrosis and acute rejection immediately after transplantation, and also for the diagnosis of acute rejection whenever it appears.

Acute Kidney Injury↗

Circulatory effects of acute or chronic endotoxemia in rats.

A study was made of the effects of acute (4 h) infusion of Escherichia coli endotoxin on cardiovascular function in rats. Rats with acute endotoxemia had a reduced cardiac output but maintained their arterial blood pressure. Fractional distribution of the cardiac output was increased to the liver and reduced to the gastorintestinal tract and skin. No changes in fractional distribution to the kidneys, lungs, or heart were observed although absolute blood flow to these areas was reduced. Rats with chronic endotoxemia had a reduced cardiac output and hypotension with no change in peripheral resistance. Other changes resembled those seen in acute endotoxemia apart from a low renal fraction of the cardiac output. Calculation and interpretation of blood flow changes in these animals was difficult because of a large fall in hematocrit and changes in organ weight.

Animals↗

Hypouricemia by defect in the tubular reabsorption.

Two patients with hypouricemia with high levels of uric acid in their urine were given pyrazinamide and probenecid. The uric acid clearance decreased to low or normal values after pyrazinamide administration. In both cases, probenecid produced a slight increment in the uric acid excretion. This type of response suggests a defect in the reabsorption component. It is tempting to speculate on a postsecretory reabsorption defect based on the results of pyrazinamide and probenecid tests.

Absorption↗

Alterations induced by large doses of furosemide in chronic renal insufficiency.

Eleven patients with different degrees of renal failure with creatinine clearances between 7 and 32 ml/min have been studied. After a standard water overload and control periods of clearances, furosemide 1 g was given/i.v. There followed significant increase of renal plasma flow and glomerular filtration rate. In one case the increase was maintained during a follow up period of 3 hours. A significant increase was evident in phosphate, uric acid, sodium, potassium, and calcium clearances, as well as an increase in the sodium delivery to the distal nephron and a decrease in tubular reabsorption of phosphate. All this may be interpreted as the result of renal vasodilation induced by furosemide and its effect upon the proximal tubule and on Henle's loop.

Blood Circulation↗

Response of plasma aldosterone to orthostatism during follicular and luteal phases of the normal menstrual cycle.

The responses of plasma aldosterone (A) and plasma renin activity (PRA) to orthostatism have been evaluated in 47 women during the follicular and/or luteal phase of the menstrual cycle. Three postmenopausal women and 51 men were also studied for control. Fourteen cycling women and 11 men were studied on a low sodium diet (20 mEq/day) while the rest of the subjects were on normal sodium intake. In addition, 18 women (including those postmenopausal) and 17 men were studied after intravenous administration of 20 mg frusemide. The response of A to orthostatism in women during luteal phase on normal sodium diet with or without frusemide was much greater than in men or women during follicular phase (p less than 0.01) or menopuase (p less than 0.05). However, no differences between groups could be observed in A response while on a low sodium diet. PRA response was similar during follicular of luteal phase fo the cycle as well as in men either on low or normal sodium intake with or without frusemide.

Adult↗

Acute renal failure after use of diesel fuel as shampoo.

After washing his hair with diesel fuel a 28-year-old patient developed acute renal failure (ARF) and oliguria requiring hemodialysis. The patient recuperated completely. In the absence of other causal factors, we believe that the absorption of the diesel fuel components, either through the respiratory tract or through the skin can be considered to be the cause of the ARF. In spite of the extended everyday use of petroleum distillation products, cases of acute intoxication are infrequent. Even rarer are cases in which these products occasion ARF.

Acute Kidney Injury↗