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Biomedical subjects

L Revert

Publications and source records attributed to L Revert.

At least 181 records · Page 10Linked to original sources
PubMed1983

Beta adrenergic modulation of extrarenal potassium disposal in terminal uraemia.

In order to study the effect of epinephrine on potassium (K) metabolism, an epinephrine infusion (0.1 micrograms/kg/min for 30 min) was carried out in 12 essentially anuric and usually hyperkalaemic haemodialysis patients, 72 hr post-dialysis. Two groups emerged, group I (five patients) serum K decreased at least 0.75 mEq/L (from 6.6 +/- 0.2 to 5.4 +/- 0.1 mEq/L) and there were increases in heart rate, serum glucose and insulin values, group II (seven patients), serum K did not decrease and heart rate remained unchanged, but serum glucose and insulin increased slightly. Plasma renin, aldosterone and arterial pH did not change in either group. Propranolol blocked the epinephrine induced decrease in serum K in group I patients. Patients from group II had higher pre-infusion endogenous epinephrine concentrations than patients from group I. In haemodialysis patients beta adrenergic stimulation enhances extrarenal K disposal but about 50 per cent of patients fail to respond, perhaps because of receptor occupancy due to higher endogenous epinephrine concentrations.

Adrenergic beta-Agonists↗
PubMed1983

Increase in serum potassium caused by beta-2 adrenergic blockade in terminal renal failure: absence of mediation by insulin or aldosterone.

To test the hypothesis that beta-blockade might impair potassium (K) tolerance in terminal renal failure we gave propranolol, and then atenolol, to a group of 12 clinically stable non-diabetic patients on chronic haemodialysis and on a constant diet containing approximately 50 mEq of K/day. Propranolol, 60 to 80 mg/day for 10 days induced a significant increase in predialysis serum K from 5.1 +/- 0.1 to 5.8 +/- 0.2 mEq/L (p less than 0.005). Atenolol (50 mg/day for 10 days) in the same group of patients did not produce a significant change in predialysis serum K (5.5 +/- 0.2 vs 5.2 +/- 0.2 mEq/L). Both propranolol and atenolol decreased heart rate but neither drug induced significant changes in plasma aldosterone, arterial pH, serum insulin or blood glucose. Thus in haemodialysis patients, beta-2 adrenergic blockade by propranolol is associated with a significant increase in serum K not mediated by pH, aldosterone or insulin, and probably due to inhibition of intracellular K uptake. Selective beta-1 adrenergic blockade by atenolol at low doses does not change serum K, and therefore, if indicated, cardioselective beta-blockers might be preferable to nonselective drugs in haemodialysis patients.

Adult↗
PubMed1983

Plasmapheresis induced recovery from renal failure in mesangiocapillary glomerulonephritis of acute onset.

Plasmapheresis (PE) was used in the treatment of three patients with biopsy proven mesangiocapillary glomerulonephritis (MCGN) of acute onset and renal failure. The percent of glomeruli with extracapillary proliferation varied from 40 to 90 per cent. Following PE, there were reductions in serum creatinine of 66 per cent, 61 per cent and 82 per cent in patients, one, two and three respectively. Plasmapheresis proved effective in a second episode of renal failure in patient three. After the completion of PE, renal function has remained stable in all patients for periods ranging from two to 12 months. However, haematuria and heavy proteinuria persist in every case. PE appears to facilitate recovery from renal failure in MCGN of acute onset, possibly by removing circulating mediators of acute inflammatory glomerular damage.

Acute Kidney Injury↗
PubMed1981

[Early diagnosis of renal ischemia in arterial hypertension by means of urine N-acetyl-beta-D-glucosaminidase (author's transl)].

Essential arterial hypertension, malignant hypertension and renovascular hypertension were studied in 64 patients, divided into 5 groups according to creatinine clearance (Ccreat) and ophthalmic fundus. Urine N-Acetyl-b-d-glucosaminidase (NAG) was expressed in units/mg creatinine in urine. Results were; Group A: Ccreat greater than 60, ophthalmic fundus less than II (n=33), NAG 13.5 + 4.5; Group B: CCreat. greater than 60, ophthalmic fundus III-IV (n=4) NAG 42.4 +/- 12.5; Group C: Ccreat. less than 60, ophthalmic fundus less than II (n = 14) NAG 31.2 +/- 10,5; Group D: (clinically malignant arterial hypertension) Ccreat. less than 60, ophthalmic fundus III--IV (n = 8), NAG 91.1 +/- 55.7 and Group E: (renovascular hypertension) Ccreat. greater than 60, ophthalmic fundus less than II (n = 5), NAG 35.5 +/- 12.9. Only the patients in Group A had NAG within normal limits. Differences were found between groups: A-B (p less than 0.001), A-D (p less than 0.001), A-E (p less than 0.001) and C-D (p less than 0.001). Urine NAG is considered to be an early sign of renal involvement in arterial hypertension, an indication of the severity and a sign of ischemia even when the involvement is unilateral only, and helpful in the management of renovascular hypertension.

Acetylglucosaminidase↗
PubMed1981

[Studies of complement, nephritic factor, and circulating immune complexes in chronic mesangiocapillary glomerulonephritis types I and II (author's transl)].

The complement components CH50, C3, C4, and C1q, factor B, nephritic factor (NF), and circulating immune complexes (CIC) have been studied in 22 patients with chronic mesangiocapillary glomerulonephritis (CMCGN). Of the 22 patients studied, eight had normal complement levels and 14 had hypocomplementemia with marked reductions of C3 and CH50. Of the latter 14 patients, nine disclosed an activation pattern that followed the alternate pathway, while in the other five the classical pathway was followed. The patients with hypocomplementemia following the alternate pathway and with positive NF activity (five cases) had a histologic pattern of type II CMCGN with dense deposits within the basal membrane, while those with hypocomplementemia following the classical pathway and negative NF activity disclosed a histologic pattern of type I CMCGN. The etiopathogenesis of these two types of glomerulonephritis remains to be elucidated. Although the presence of CIC is discussed and they are only rarely detected with the usual techniques, immune complexes have been implicated as possible responsible factors in these diseases. It has been demonstrated that the NF is an IgG with the characteristics of an autoantibody specific against the C3bB and C3bBb convertases of the alternate pathway, thus forming the trimolecular complex C3bBbNF. Because serum NF is frequently associated to type II CMCGN, it could be speculated that this trimolecular complex behaves as an immune complex, the convertase C3b beeing the antigen and the NF, the antibody, and that, under certain circumstances and because of its low molecular weight, it could cause nephritis by its deposit in the glomerular basal membrane.

Antigen-Antibody Complex↗
PubMed1981

[Prolonged hypotension after the first dose of atenolol (author's transl)].

A 30 year-old male patient with accelerated arterial hypertension relatively resistent to diazoxide received a single oral dose of 100 mg of atenolol, following which hypotension of more than 24 hours duration and acute renal failure ensued. These alterations were reversible and did not recur with subsequent doses of atenolol. Prior therapy with diazoxide might have potentiated the hypotensive action of atenolol. The abnormality could be due to a phenomenon of hyperreactivity to the first dose of atenolol, similar to what has been described following first doses of prazosin or labetalol. This observation suggests that atenolol therapy must be started with caution, especially in patients previously treated with diazoxide.

Acute Kidney Injury↗
PubMed1981

[Essential hypertension and diabetes].

Exchangeable sodium (E-Na), plasma volume (PV), and plasma renin activity (PRA) have been studied in 19 patients with essential hypertension and diabetes, and the results compared to those of non-diabetic patients with benign essential hypertension. None of the cases had renal disease or hypertension with systolic predominance. E-Na was 114 +/- 9.74 (SD), significantly superior to that of normal subjects (p less than 0.001). An elevated E-Na was observed in 52.6% of the diabetic group, while PV was normal. PRA levels were normal in most patients, mean 1.28 +/- 1.97 ng ml-1 h-1, only two patients disclosing an elevated PRA (10.5%). No relationship was found between PRA and age, blood pressure, and E-Na. From the comparison of results between diabetic and non-diabetic hypertension patients it appears that: 1) no differences between mean PRA and E-NA exist, although a greater percentage of diabetics have an elevated E-Na, and 2) in the non-diabetic group there is a positive correlation between E-NA and PV, while in the diabetic group such a correlation is negative (p less than 0.05). The finding of an elevated body sodium in patients with essential hypertension and diabetes probably represents a true abnormality in the body composition of these patients, although there is no explanation for the fact that it is unassociated to an increase of the plasma volume, as opposed to essential hypertension in non-diabetics.

Adult↗
PubMed1981

Acute and rapidly progressive forms of glomerulonephritis in the elderly.

This article presents a comparison of acute glomerular nephritis (AGN) with rapidly progressive glomerular nephritis (RPGN) in patients aged 60 or older. In 7 elderly patients with AGN, the renal disease was preceded by skin infection (4 cases), sore throat (2 cases), or pneumonia (1 case). The 7 patients with RPGN had no history of prior infection. Both AGN and RPGN were manifested clinically as acute renal failure, but the RPGN patients had significantly higher serum creatinine levels and lower hematocrit readings. Hypocomplementemia was a feature only of AGN. The biopsy specimens from patients with RPGN showed crescents in 50--100 percent of the glomeruli, whereas specimens from patients with AGN showed no significant extracapillary proliferation. Six AGN patients recovered and 1 died. Despite dialysis, 4 RPGN patients died and the remaining 3 require maintenance dialysis. It is concluded that AGN in the elderly is more common than previously believed, frequently follows skin infections, and has a reasonably good prognosis. In contrast, RPGN, also not rare in the elderly, has a much worse prognosis.

Acute Disease↗