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Biomedical subjects

K J Berg

Publications and source records attributed to K J Berg.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effects of short-term treatment with naproxen on kidney function in insulin-dependent diabetic patients with microalbuminuria.

The renal effects of the prostaglandin synthesis inhibitor naproxen was investigated in eight patients with incipient type I diabetes nephropathy. The patients were treated with 1000 mg naproxen daily for 4 days in a placebo-controlled double-blind cross-over study. Naproxen reduced urinary prostaglandin E2 (PGE2) excretion by 60%, from 276 ng/24 h to 110 ng/24 h (P less than 0.05). Plasma renin activity (PRA) was reduced by 45% (P less than 0.05). Glomerular filtration (GFR) (single bolus 99mTc-DTPA technique) and effective renal plasma flow (ERPF) (131I-Hippuran clearance) were unchanged by naproxen. Microalbuminuria and renal albumin clearance was unchanged as was also urinary excretion of sodium, glandular kallikrein and beta 2-microglobulin (beta 2-M). Our results show that albumin excretion in incipient diabetic nephropathy is not solely dependent on the renal prostaglandin system. The difference in action between naproxen in this study and indomethacin in previous reports, could be caused by renal actions of indomethacin independent of the prostaglandin system.

Adult↗
PubMed1991

Effects of isradipine on renal function in cyclosporin-treated renal transplanted patients.

The renal effects of the calcium-channel antagonist isradipine were evaluated in cyclosporin A (CsA)-treated renal allografted patients more than 5 months after transplantation. Twelve patients with stable renal function were given placebo for 2 weeks and then isradipine 1.25 mg x 2 for 1 week and 2.5 mg x 2 for the next 3 weeks in an open trial. The CsA dose was unchanged during the study. Isradipine did not interfere with the pharmacokinetics of CsA as both whole blood trough and peak levels were unchanged. Isradipine reduced mean arterial blood pressure (MAP) from 117.0 +/- 1.8 to 106.3 +/- 1.9 mmHg (P less than 0.01). The renal effects were studied during water diuresis 1-3 h after drug intake. Para-aminohippurate clearance (CPAH) increased from 256.4 +/- 21.5 to 291.5 +/- 26.3 ml/min (P less than 0.05), renal vascular resistance was reduced by 21.5% (P less than 0.01) and inulin clearance (CIn) was unchanged. Fractional proximal reabsorption, calculated from lithium clearance (CLi), was reduced by 11.9% (P less than 0.01) by isradipine. Isradipine also reduced proximal reabsorption of sodium (APRNa) and increased distal sodium delivery (DDNa). Distal sodium reabsorption (ADRNa) and free-water clearance (CH2O) were significantly increased. Urinary excretion of enzymes and proteins was unchanged by isradipine.

Adult↗
PubMed1991

Lack of effect of the calcium antagonist isradipine on cyclosporine pharmacokinetics in renal transplant patients.

Hypertension has emerged as a frequent side effect in transplant recipients on effective doses of cyclosporine (CsA). To control hypertension in renal transplant patients, calcium channel blockers have been used; some of these, however, have been shown to cause significant increases in CsA levels. These findings point out that possible interactions of each calcium antagonist with CsA deserve investigation. We performed an open, placebo-controlled study in 12 stable renal transplant recipients to determine whether short-term isradipine influences CsA pharmacokinetics. All patients had mild to moderate hypertension and received triple immunosuppressive therapy with CsA, azathioprine, and prednisolone. Throughout a 4-week period of isradipine treatment, blood CsA levels (specific and nonspecific monoclonal antibodies) remained stable. The mean trough specific level was 121 +/- 14 micrograms/L following placebo, compared to 120 +/- 14 micrograms/L during isradipine. Corresponding non-specific values were 465 +/- 68 and 474 +/- 63 micrograms/L. Also, values for Cmax, AUC, and t1/2 were not significantly changed following 4 weeks of isradipine. Mean arterial pressure was significantly reduced at the end of the study. This study implies that isradipine does not influence CsA metabolism. Further studies should be carried out to determine its long-term effects on CsA pharmacokinetics and renal function in transplanted patients.

Adult↗
PubMed1991

Contrasting effects of lisinopril and nifedipine on albuminuria and tubular transport functions in insulin dependent diabetics with nephropathy.

An open, randomized, cross-over study was undertaken to assess the effects of lisinopril and nifedipine on albumin excretion, renal haemodynamics and segmental tubular reabsorption in overt diabetic nephropathy. The study consisted of a 4-week run-in period, a 3-week active treatment period, a 4-week wash-out period and a second 3-week active treatment period. Twelve patients with type 1 diabetes with albuminuria, mild to moderate hypertension and a serum creatinine level of less than 200 mumol l-1 were included. Lisinopril reduced albumin excretion from 1343 +/- 337 micrograms min-1 to 879 +/- 299 micrograms min-1 (P less than 0.01), whereas nifedipine was without effect, 1436 +/- 336 micrograms min-1 vs. 1319 +/- 342 micrograms min-1. Glomerular filtration rate (GFR) was unchanged by either drug. Both drugs increased effective renal plasma flow (ERPF) by about 20%. No differences between the drugs were observed with regard to their effect on renal haemodynamic parameters. By contrast, nifedipine exerted an inhibitory effect on several proximal tubular transport markers, whereas lisinopril was without effect. The different actions on tubular transport mechanisms exerted by lisinopril and nifedipine may contribute to the observed effect on albumin excretion.

Adult↗
PubMed1991

Do extracorporeal shock waves affect urinary excretion of glycosaminoglycans?

Urinary excretion of glycosaminoglycans (GAGs) was studied in 9 anaesthetised dogs and 10 patients with single kidneys. The animals were studied for 4 to 5 hours after administration of shock waves to 1 kidney, the contralateral organ serving as control. Urinary excretion of GAGs was measured on both sides. The patients were studied 0 to 24 and 32 to 56 h after extracorporeal shock wave lithotripsy (ESWL). In the animals an increased mean urinary excretion of GAGs was observed on both sides; this was more marked in the treated kidney. The increase reflects tissue injury in the exposed kidney induced by the extracorporeal shock waves. No increase in mean urinary excretion of GAGs was observed in the patients.

Adult↗
PubMed1991

Acute changes in kidney function following extracorporeal shock wave lithotripsy for renal stones.

Seventeen patients were subjected to analysis of various renal functional parameters before and after extracorporeal shock wave lithotripsy (ESWL) for renal stones. Thirteen patients were observed at 2 weeks and 3 months. Glomerular filtration rate (GFR) was not influenced by ESWL as based on unchanged serum levels of creatinine, beta 2-microglobulin and creatinine clearance. A significant increase in urinary excretion of beta 2-microglobulin, N-acetyl-beta-glucosaminidase and alkaline phosphatase, with return to pre-treatment values within 4 to 5 days, reflected transient disturbances in proximal tubular function. Urinary albumin excretion was increased 0-24 h after ESWL. No significant alterations were observed in plasma renin activity or serum aldosterone due to ESWL. Serum lactic dehydrogenase remained significantly increased for 2 weeks. In addition, significant changes in several blood and urine parameters were caused by immersion in water and intravenous infusions during treatment and were not specifically due to ESWL.

Acetylglucosaminidase↗
PubMed1991

Renal effects of iopentol and iohexol after intravenous injection.

Renal effects of the 2 non-ionic contrast media iopentol and iohexol were investigated and compared in a double-blind, randomized parallel study where 30 patients received iopentol, and 31 patients iohexol intravenously for abdominal CT. The dosage of contrast medium (350 mg I/ml) was 700 mg I/kg body weight. Only one patient (in the iohexol group) had an increase in serum creatinine of more than 50%. Iopentol and iohexol had no effects on the mean serum values of creatinine, urea, and beta 2-microglobulin (beta 2-MG) nor on creatinine clearance. The urinary excretion of albumin and beta 2-MG was also unchanged. The excretion of the proximal tubular enzymes alkaline phosphatase and N-acetyl-beta-glucosaminidase was increased. No significant difference between iopentol and iohexol was found.

Acetylglucosamine↗
PubMed1990

[Acetylsalicylic acid in the prevention of arterial thrombosis. Dosage problems in general and in the authors' experiment].

Acetylsalicylic acid is now accepted as a clinically useful drug for secondary prophylaxis against several thromboembolic complications, but there is still much controversy about the dosage. We discuss this problem, in the light of data from newly published clinical trials and of results from a pharmacological study performed by ourselves. All in all it seems reasonable to recommend 100-150 mg acetylsalicylic acid per day for prophylaxis after acute myocardial infarction. As for cerebrovascular indications, no clinical data available so far justify a dose reduction below 300 mg.

Adult↗
PubMed1990

Acute physiological changes in canine kidneys following exposure to extracorporeal shock waves.

Nine anesthetized dogs were studied for four to five hours after administration of extracorporeal shock waves to one kidney, the contralateral organ serving as control. Urinary excretion of electrolytes, N-acetyl-beta-glucosaminidase (NAG) and kallikrein, clearances of creatinine, inulin and para-amino-hippuric acid (PAH), serum aldosterone level and plasma renin activity (PRA) were determined. On the exposed side there was a significant increase in urinary flow and urinary NAG excretion, and a significant fall in urinary osmolality. Effective renal plasma flow (ERPF) was reduced and glomerular filtration rate (GFR) unchanged, thus filtration fraction (FF) was increased. Extraction of PAH was significantly reduced compared with the control kidney. On the control side there was a significant increase in urinary flow and excretion of electrolytes, and a significant fall in urinary osmolality. GFR was increased and ERPF unchanged. FF therefore increased also on this side. The mean rise of PRA in the exposed kidney was higher than in the control kidney, the difference being not significant (p = 0.09). Our results may indicate a triggering of the renin-angiotensin system, and an effect on proximal tubular function following exposure of extracorporeal shock waves.

Animals↗
PubMed1990

Elimination of iohexol, a low osmolar nonionic contrast medium, by hemodialysis in patients with chronic renal failure.

The dialyzability of iohexol was examined in patients with chronic renal failure on long-term hemodialysis treatment. Eight patients had iohexol (Omnipaque 240 or 350 mg I/ml) injected in doses between 98 and 1,493 mg I/kg body weight (BW) 25 h (mean time) before start of hemodialysis. Dialysance of iohexol was 81 +/- 15 ml/min (mean +/- SD) compared to 120 +/- 16.8 ml/min for creatinine. Elimination half-life for iohexol during hemodialysis was 3.9 +/- 1.1 h while plasma clearance was 64 +/- 17 ml/min. The distribution volume calculated (0.25 +/- 0.05 liters/kg BW) confirms previous observations with distribution in the extracellular fluid only. Before the start of hemodialysis 36 +/- 28% of the dose injected was eliminated, indicating some extrarenal elimination. After 4 h of hemodialysis 72 +/- 11% of the dose was removed.

Adult↗
PubMed1990

Acute effects of paracetamol on prostaglandin synthesis and renal function in normal man and in patients with renal failure.

The effects of oral dosing with paracetamol (40 mg/kg/day for 3 days) on serum thromboxane B2 (TXB2), glomerular filtration rate (GFR), sodium homeostasis, urinary excretion of prostaglandin E2 (PGE2) and on some other renal function parameters were investigated in 10 healthy young controls aged 23-26 years, 9 healthy elderly persons with normal renal function aged 66-78 years and 9 patients with chronic stable impaired renal function. Plasma paracetamol concentration was unaffected by age and GFR, whereas the sulphate and glucuronide metabolites of paracetamol accumulated substantially in patients with renal failure, and to a lesser degree in elderly controls. Serum TXB2 was significantly reduced 1 and 4 hours after oral ingestion of a single dose of paracetamol (18 mg/kg), but the values were normalized after 12 hours. Urinary sodium excretion was reduced by 23.4% on the first treatment day in elderly controls, but unchanged in young controls and in patients with renal failure. Urinary excretion of PGE2 was unchanged in young controls, but reduced by 35.9% on the first day on paracetamol treatment in elderly controls and from 22-29% on the 3 days on paracetamol in patients with impaired renal function. Paracetamol was without effect on potassium homeostasis or on the excretion of glandular kallikrein or proteins in urine. Our study indicates that oral treatment with paracetamol in therapeutic doses reversibly reduces serum TXB2 for at least 4 hours after ingestion both in healthy controls and in patients with impaired renal function. Our data also suggest that paracetamol effects renal PGE2 excretion, especially in patients with impaired renal function. Renal glomerular and tubular function parameters were unchanged by paracetamol.

Acetaminophen↗
PubMed1990

Renal effects of the non-ionic contrast medium iopentol after intravenous injection in healthy volunteers.

Renal effects of the new non-ionic contrast medium iopentol in increasing doses were assessed and compared with the effects of physiologic saline. Twenty-four healthy male volunteers, allocated to three dose groups, were given iopentol intravenously in doses of 0.3, 0.6, and 1.2 g I/kg body weight, respectively. The highest dose group was also given physiologic saline separately as a control. The diuresis increased in all groups, most in the highest dose group, and with a concomitant fall of urine osmolality and increase in osmolar clearance. A slight decrease of serum osmolality, creatinine and urea occurred at 3 hours due to hemodilution. The glomerular filtration rate was unaffected by iopentol. The urinary excretion of albumin and beta 2-microglobulin was unchanged. However, urinary N-acetyl-beta-glucosaminidase and alkaline phosphatase increased significantly, most in the highest dose group. All changes were reversible.

Acetylglucosaminidase↗