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Biomedical subjects

D de Zeeuw

Publications and source records attributed to D de Zeeuw.

At least 181 records · Page 10Linked to original sources
PubMed1986

Restenosis prevalence and long-term effects on renal function after percutaneous transluminal renal angioplasty.

We studied the frequency of restenosis and the effects of percutaneous transluminal renal angioplasty (PTRA) on blood pressure (BP) and particularly on renal function in all patients in whom successful dilatation was performed. Restenosis was found in 42% of the patients with an atherosclerotic renal artery stenosis and in 22% of the patients with fibromuscular dysplasia. BP improvement was seen in 70-80% of the patients with unilateral stenosis or with successful bilateral dilatation (group I) whereas only seldom was an effect on BP observed in patients with more complicated disease, such as those with an occlusion of the contralateral artery (group II). Remarkably, however, both in group I and in group II, in about half of the patients an improvement in renal function was found, even 2-3 years after the procedure. Our results thus indicate that PTRA can be useful in preservation or even improvement of renal function, even if no effect on blood pressure can be expected.

Adult↗
PubMed1986

Enalapril and the kidney: renal vasodilation and natriuresis due to the inhibition of angiotensin II formation.

Essential hypertension is characterized by increased renal vascular resistance, which also has definite implications for renal sodium handling. We studied the possibility of correcting these abnormalities by inhibiting angiotensin-converting enzyme with enalapril. Enalaprilic acid produced renal vasodilation. This, particularly postglomerular, vasodilation was accompanied with an increase in sodium excretion. The natriuresis was positively correlated to initial plasma renin activity. During continuous treatment with enalapril up to 12 weeks, this vasodilation persisted in 22 patients with essential hypertension. We also showed that orally administered enalapril induces natriuresis, both during a 50-mmol and during a 200-mmol sodium intake a day. This natriuresis caused a net negative sodium balance of approximately 120-140 mmol Na after 1 week of enalapril therapy. This was accompanied with a fall in body weight. We conclude that enalapril in essential hypertension alleviates the angiotensin-II-mediated abnormalities in renal hemodynamics and sodium excretion.

Administration, Oral↗
PubMed1986

Renal effects of ketanserin in essential hypertension.

The effects of maintenance treatment with ketanserin 40 mg twice daily on renal haemodynamics were studied in 13 essential hypertensives. To establish whether activation of the renin system modifies the response to ketanserin the patients were studied under three conditions: on a sodium restricted diet combined with hydrochlorothiazide, on a sodium restricted diet without hydrochlorothiazide and on a liberal sodium diet. Blood pressure fell in a proportion of the patients on all three regimens. Neither effective renal plasma flow (ERPF; clearance of 131I-hippuran) nor glomerular filtration rate (GFR; clearance of 125I-iothalamate) was significantly altered by ketanserin on either regimen. Neither the blood pressure response nor the renal response was modified by renin stimulation. The renal response was not related to the fall in blood pressure observed in some patients. Therefore ketanserin probably does not affect renal autoregulation.

Adult↗
PubMed1986

Reduction of urinary protein and prostaglandin E2 excretion in the nephrotic syndrome by non-steroidal anti-inflammatory drugs.

Seven salt depleted patients with the idiopathic nephrotic syndrome were treated with various non-steroidal anti-inflammatory drugs. Indomethacin, diclofenac-sodium and flurbiprofen decreased proteinuria, glomerular filtration rate, plasma renin activity and renal prostaglandin E2 excretion by 59%, 19%, 55% and 68% respectively. Sulindac induced no major changes in proteinuria, glomerular filtration rate, plasma renin activity and renal prostaglandin E2 excretion. The relative change in proteinuria and glomerular filtration rate during non-steroidal anti-inflammatory drug treatment correlated strongly with that of the renal prostaglandin E2 excretion (r = 0.89 and r = 0.70, respectively p less than 0.05). It is likely that the anti-proteinuric effect of non-steroidal anti-inflammatory drugs is dependent on their potency to inhibit renal prostaglandin synthesis and it is suggested that this effect is mediated by lowering transcapillary glomerular hydraulic pressure.

Adult↗
PubMed1986

Nephrotic syndrome preceding Hodgkin's disease by 42 months.

A 52-year-old man developed minimal change nephrotic syndrome which responded only partially to prednisolone. The addition of cyclophosphamide resulted in a complete remission. During a second episode of nephrotic syndrome prednisolone and cyclophosphamide only gave a partial remission. During a third episode, 42 months after the initial presentation, Hodgkin's disease clinical stage IA was diagnosed. Mantle field radiation therapy was given after which proteinuria gradually decreased to zero in the course of 17 months. The patient has remained free of disease until now (15 months).

Cyclophosphamide↗
PubMed1985

Blood pressure response to enalaprilic acid in essential hypertension: dose-response and effect of pre-treatment with furosemide.

Enalaprilic acid (MK 422), the active metabolite of enalapril, has recently become available for intravenous administration. In order to establish the proper dose for rapid blood pressure reduction, 9 patients with moderate to severe essential hypertension on a constant sodium intake of 100 mmol/24h were studied. They received four single doses of MK 422 according to an up-and-down titration schedule. Doses between 5 and 80 mg resulted in effective blood pressure reduction with an onset of action of about 10 minutes. Within this dose range the response was flat. No symptomatic hypotension was observed. The fall in blood pressure was less pronounced in patients with low initial plasma renin activity (PRA). Accordingly, a study was done to show whether the blood pressure response could be augmented by preceding stimulation of PRA by injection of 40 mg furosemide 15 minutes before the administration of MK 422. PRA increased after furosemide, but the blood pressure response to MK 422 was not augmented.

Adult↗
PubMed1985

Pharmacological zero for electromagnetic renal blood flow measurement.

Measurement of blood flow in chronically instrumented laboratory animals using electromagnetic flow probes depends on a reference "zero flow" value. The latter is usually obtained by mechanical vessel occlusion. We tested an alternative method: a bolus of angiotensin II was injected in the abdominal aorta resulting in an immediate decrease of renal blood flow. Diastolic blood flow at this stage appeared to be identical to the zero level obtained by mechanical occlusion. Thus, pharmacological interruption of renal blood flow may serve as a zero reference in the dog.

Angiotensin II↗
PubMed1985

Antiproteinuric effect of naproxen and indomethacin. A double-blind crossover study.

In a double-blind crossover study in 10 salt-depleted nephrotic patients the reduction of proteinuria was significantly larger during indomethacin 50 mg three times daily than during naproxen 250 or 500 mg three times daily (72 vs. 44%, p less than 0.05; 77 vs. 46%, p less than 0.05, respectively). Both drugs induced similar reversible intrarenal hemodynamic changes, but indomethacin had more pronounced effects than naproxen. A common pathway, such as the reduction of the glomerular filtration rate and a reduction of the glomerular transcapillary hydraulic pressure, is likely to explain the observed phenomena and is most probably mediated by inhibition of intrarenal prostaglandin synthesis. If treatment with a nonsteroidal anti-inflammatory drug is considered in patients with the idiopathic nephrotic syndrome, indomethacin appears up to now the most effective agent in reducing urinary protein loss.

Adult↗
PubMed1985

Immune response to two different hepatitis B vaccines in haemodialysis patients: a 2-year follow-up.

Formalin-inactivated hepatitis B vaccine was given at 0, 1 and 6 months to 22 medical staff members and to 37 haemodialysis patients. After vaccination with 20 micrograms surface antigen (HBsAg), seroconversion occurred in 95% of the staff members. Following immunisation with a double dose, only 74% of the haemodialysis patients developed antibodies against HBsAg (anti-HBs). Anti-HBs levels were lower in the patient group and 6 responders (23%) became anti-HBs-negative within 2 years. 40 other haemodialysis patients were immunised at monthly intervals with either three doses of 3 micrograms or three doses of 27 micrograms heat-inactivated hepatitis B vaccine. Seroconversion was achieved in 60% of the patients in the 3-micrograms group and in 95% of the patients in the 27-micrograms group. Anti-HBs levels increased significantly when the high dose was used. Although the study design does not allow a definite conclusion, it appears that the immunogenicity per microgram HBsAg is higher for the heat-inactivated vaccine than for the formalin-inactivated vaccine. The findings further indicate that decreased immune response to hepatitis B vaccination in haemodialysis patients can be improved by increasing the dose of the vaccine. A booster injection should be considered in these patients within 2 years after the first vaccination.

Adult↗
PubMed1985

Effects of enalaprilic acid on sodium excretion and renal hemodynamics in essential hypertension.

The effects of MK 422 (enalaprilic acid) on renal function and electrolyte excretion were assessed in 14 patients with essential hypertension on a sodium intake of 100 mmol/day. Injection of MK 422 led to a prompt fall in blood pressure (p less than 0.01). Effective renal plasma flow increased by 9 +/- 4% (p less than 0.01) within 1 hour, an increase that persisted for a least 5 hours. Glomerular filtration rate did not change, so filtration fraction decreased by 6 +/- 2% (p less than 0.01). Sodium excretion increased with a maximum of 61 +/- 17% (p less than 0.01) after 5 hours, and potassium excretion fell (p less than 0.01). The log of the initial plasma renin activity correlated with the changes in blood pressure (r = 0.59, p less than 0.05) in effective renal plasma flow (r = 0.59, p less than 0.05) and in sodium excretion (r = 0.65, p less than 0.01). All the renal effects of MK 422 could be reversed by infusion with angiotensin II.

Blood Pressure↗
PubMed1983

The angiotensin converting enzyme inhibitor enalapril and its effects on renal function.

The renal effects of the new angiotensin converting enzyme inhibitor enalapril (MK-421) and of its active metabolite MK-422, were investigated in patients with essential hypertension. Together with a reduction in blood pressure, renal blood flow increased after intravenous injection of MK-422. Glomerular filtration as well as fractional sodium excretion increased. The latter was explained by the inhibition of both proximal and distal tubular sodium reabsorption. During oral enalapril therapy renal blood flow remained elevated, whereas glomerular filtration did not differ significantly from pretreatment values. Body weight fell after 12 weeks of therapy, a possible consequence of the 'diuretic' effect of enalapril which may contribute to the antihypertensive action of the drug. In conclusion, enalapril had either no, or even beneficial, effects on renal function.

Administration, Oral↗
PubMed1983

Restenosis of the renal artery after percutaneous transluminal renal angioplasty: an inevitable outcome?

We performed follow-up studies in 26 patients four to 36 months after percutaneous transluminal renal angioplasty. Restenosis was found in 47 per cent of the patients who had an atherosclerotic type of stenosis and in 14 per cent of the patients with fibromuscular dysplasia. We could not detect any significant differences between the atherosclerotic patients who did develop restenosis and those who did not. In fact, the presence of generalised atherosclerosis, the severity of the stenosis and the initial success of the dilatation were similar in the two groups. It thus cannot be predicted which patients will develop restenosis.

Angioplasty, Balloon↗