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Biomedical subjects

B G Danielson

Publications and source records attributed to B G Danielson.

At least 55 records · Page 3Linked to original sources
PubMed1992

Serum erythropoietin levels in the immediate kidney-posttransplant period.

Following successful kidney transplantation, renal anemia is gradually corrected during the first 3-4 months. Serum erythropoietin (EPO) levels are increased after the first postoperative day following grafting. In this study, the serum EPO levels in the early posttransplant phase were investigated in 8 living-donor and 7 cadaveric-kidney transplant recipients with special emphasis on the first 24 h. Despite a considerable difference in cold ischemic time of the graft in the two groups the increase in serum EPO levels was noticed at about the same time (8 h) in both groups and the first peak of serum EPO, which was observed after 24 h, reached the same level in both groups. After 9-11 days, serum EPO reached levels which usually are observed during the first months following transplantation. The EPO response seems to be blunted in relation to the degree of anemia in the early posttransplant phase.

Adult↗
PubMed1992

Treatment of pruritus in cholestatic jaundice by bilirubin- and bile acid-adsorbing resin column plasma perfusion.

The efficacy of plasma perfusion through a new anionic resin, BR-350, for palliation of intractable pruritus secondary to intrahepatic cholestasis was studied in four patients. The treatment was given in a daily 2-h session on 3 consecutive days and was followed by repeated treatment periods each 3rd to 4th week. The patients experienced symptomatic improvement during the first treatment period, and the treatment was well tolerated. Adsorption of bile acids across the filter was efficient and resulted in a bile acid concentration gradient pre- to post-resin of 92%. Thus plasma perfusion through the ion resin BR-350 is an effective and safe treatment for symptomatic relief of intractable pruritus in cholestatic liver disease and may reduce hospitalization time and increase the quality of life.

Adult↗
PubMed1992

Parathyroid function in relation to intestinal function and renal calcium reabsorption in patients with nephrolithiasis.

Recently a technique to measure intact parathyroid hormone (PTH), i.e. the biologically active hormone, has been available. The aim of the present study was to apply this method to evaluate the parathyroid function in a material of recurrent renal stone formers (n = 324). Intact PTH was found to be inversely related to both urinary calcium (r = -0.15; p less than 0.01) and serum calcium (p less than 0.02) indicating that in the majority of the patients with hypercalciuria this was accounted for by intestinal hyperabsorption and not by high serum PTH. Hyperabsorption was also the likely explanation for the finding of a positive relationship between the urinary calcium and oxalate excretions (r = 0.22; p less than 0.001) in medication-free patients without intestinal disorders, i.e. without enteric hyperoxaluria. Altogether 25 patients (7%) had elevated serum PTH concentrations. They were followed up with fasting serum and urinary electrolytes and an oral calcium loading test (1 g of calcium) in order to evaluate the importance of renal and intestinal factors responsible for the elevated serum PTH concentrations. The investigation was carried out on a free diet and on low and high calcium intakes, respectively. The incidence of intestinal malfunction, which was sometimes present without clinical symptoms, was found to be approximately the same as that of impaired renal conservation of calcium. The findings in the patients with intestinal malfunction were a reduced intestinal absorption of calcium and an enhanced tubular reabsorption of calcium (TRCa), with greater reabsorption of calcium for higher PTH values. In patients with impaired renal conservation of calcium despite the raised PTH there was no correlation between PTH and TRCa. When PTH was suppressed during the oral calcium load the TRCa was found to be inappropriately low and the renal defect obvious. The intestinal calcium absorption was secondarily increased to compensate for the renal losses.

Adolescent↗
PubMed1992

Outcome of renal transplantation in patients treated with erythropoietin.

The introduction of treatment with recombinant human erythropoietin (rhEPO) has raised the possibility of deleterious effects on early kidney graft function. Due to renal anemia, the great majority of patients waiting for kidney transplantation until now have had a low hematocrit. It has been suggested that a low hematocrit is beneficial for early kidney graft function by protecting the transplanted kidney from so-called reperfusion damage, which results in delayed onset of renal function. We have retrospectively examined the early function of 26 kidney grafts transplanted to uremic patients with rhEPO corrected anemia. Compared with a randomized control group no significant differences were seen in the rate of immediate onset of graft function, graft survival or serum levels of creatinine one year after transplantation. We conclude that the reversing of anemia by rhEPO in recipients of cadaver kidneys does not impair early graft function.

Anemia↗
PubMed1991

Experience with vascular access for acute renal failure: using Buselmeier shunt and femoral vessel catheter.

Three types of vascular access were evaluated over a period of 2 years, January 1987-December 1989, in 76 critically ill acute renal failure (ARF) patients. The Buselmeier shunt comprised 75% of the acute vascular access which were utilized, the cannulation of the femoral vessel 23% and the Scribner shunt 2%. The Buselmeier shunt was successfully used alone (mainly in the forearm) in 58 patients for continuous arteriovenous hemofiltration, continuous arteriovenous hemodialysis and intermittent hemofiltration. Thrombosis was noted in 7% of the shunts, where the majority needed a new shunt either on the same or the contralateral arm. Blood leakage was noted in 2%, hematoma in 1%, and accidental bleeding in 1% of the shunts. This study showed that the Buselmeier shunt is more used in our center, most likely because it is easy to bypass the hemodialysis filter by the staff nurse in case of clotting. No major complications were noted even if kept in place for a longer period of time. It offers adequate blood flow for continuous renal replacement therapy and intermittent hemofiltration in ARF.

Acute Kidney Injury↗
PubMed1991

Plasma atrial natriuretic factor (alpha ANF) during hemodialysis (HD) and hemofiltration (HF).

Plasma concentrations of immunoreactive alpha ANF were measured before, during, and after 3 hours of hemodialysis (HD) and hemofiltration (HF). In seven healthy subjects plasma alpha ANF concentrations were measured to serve as controls. Highly elevated pre-treatment alpha ANF levels were obtained in the HD group (286 +/- 52 pg/ml, mean +/- SE), and in the HF group (275 +/- 48 pg/ml) as compared with the controls (40 +/- 3 pg/ml). The effect of both HD and HF on the alpha ANF concentration was not significant after the first hour of treatment. However, a significant decrease was obtained after the second (HD = 244 +/- 49, HF = 140 +/- 17) and third hours (HD = 244 +/- 48, HF = 135 +/- 15) (p less than 0.05) in both treatments. A steeper decline in the alpha ANF concentration was notable during HF compared with HD. There was a significant difference (p less than 0.05) when both modalities were compared at the end of treatment. A correlation (r2 = 0.98, p less than 0.001) was noted between changes in the alpha ANF levels and the ultrafiltration (UF) volumes only during HF. Plasma alpha ANF concentrations at the filter outlet were lower than at the inlet in both groups. It is concluded that the plasma alpha ANF concentrations are highly elevated in chronic renal failure patients. Despite the decrease in these concentrations during HD and HF it did not reach the normal plasma level. Monitoring of plasma alpha ANF may be a useful indicator for the extracellular volume status during HD and HF treatments.

Adult↗
PubMed1991

Values of intact serum parathyroid hormone in different stages of renal insufficiency.

Intact serum parathyroid hormone (PTH) values were determined in 136 patients consulting the out-patient clinic for renal medicine and in 36 patients on maintenance hemodialysis in order to reveal the extent of parathyroid involvement in different stages of renal insufficiency. Elevated PTH values were found in 53 of the conservatively treated patients and in all but 4 of those on hemodialysis. Serum creatinine values and the duration of uremia correlated significantly to serum PTH, and multivariate analyses revealed that these variables were of dominating importance in determining the extent of PTH elevation. The negative relationship between PTH and plasma ionized calcium indicated maintained calcium regulation of hormone release from the parathyroid, although a relative secretory autonomy seemed to develop in parallel with the functional renal impairment. It is concluded that measurements of intact serum PTH values can demonstrate parathyroid hypersecretion in early renal insufficiency and constitutes a useful tool in the management of patients with renal disease.

Adolescent↗
PubMed1991

Calcium acetate used as phosphate binding treatment in uremic hyperphosphatemia.

Due to toxic side effects of aluminum-containing agents for treatment of uremic hypophosphatemia, much interest has been focused upon aluminum-free phosphate binder alternatives. From results of experimental studies with calcium acetate, this salt has been suggested as a possible effective and safe phosphate binder. In the present study, calcium acetate was used during a mean of 11 months for serum phosphate control in 30 uremic patients previously treated with aluminum and/or calcium carbonate. Satisfactory control of serum phosphate was achieved during the study (mean phosphate concentration +/- SE: 2.15 +/- 0.12 mmol/l compared to prestudy 2.23 +/- 0.19 mmol/l). Mean serum concentrations of calcium, alkaline phosphatase and parathyroid hormone did not change significantly during the study. Serum aluminum decreased significantly (p less than 0.01). Moderate hypercalcemia was observed in 6 patients. Calcium acetate treatment was withdrawn in 2 patients due to gastrointestinal discomfort. It is concluded that calcium acetate seems to be an effective phosphate binder alternative with relatively few side effects.

Acetates↗
PubMed1990

Pharmacokinetics of intravenous imipenem/cilastatin during intermittent haemofiltration.

The pharmacokinetics of a single iv dose of imipenem/cilastatin (500/500 mg) were studied during and after intermittent haemofiltration (IHF) treatment in six patients with chronic renal failure. The elimination half-lives of imipenem and cilastatin during the IHF treatment were almost identical, 1.4 +/- 0.3 and 1.5 +/- 0.3 h, respectively. Accordingly, approximately 75% of the given dose was eliminated during a 3-h IHF session. However, there was a great difference between the elimination half-lives of the two drugs in the post-treatment period, 3.4 +/- 1.0 and 16 +/- 10 h for imipenem and cilastatin, respectively. The haemofiltration clearance of imipenem was 134 +/- 41 ml/min and that of cilastatin 109 +/- 8 ml/min. On the basis of our results, we suggest that a supplementary dose of imipenem/cilastatin (500/500 mg) should be given directly after the IHF treatment. This dose should be the starting dose for a period of 12-h dosing intervals until the next IHF procedure.

Adult↗
PubMed1990

Experience with the Hemasite device in haemodialysis and haemofiltration patients with vascular access problems.

Multiple vascular access failure is a frequent problem and we report our experience with 32 Hemasite devices implanted in 28 patients with end-stage renal disease. All of the patients were on maintenance haemodialysis or haemofiltration with a range of treatment of 1-17 years. Their mean age was 58 +/- 14 years (range 28-72 years). The main indication for using this device as an alternative vascular access was the presence of high-risk patients with a high incidence of previous access failure (1-8 accesses per patient). The majority of the patients were considered as high risk, due either to old age (more than 60 years) (60%) or to the presence of diabetes mellitus (29%). The results of 5 years' experience and follow-up showed that the Hemasite device could be successfully used as a secondary vascular access in high-risk patients who have problems of multiple access failures. The 1-year cumulative survival of the device (55%) was affected by complications such as thrombosis and infection (47% and 16%) which were noted mostly among patients with diabetes mellitus. These complications are the major ones endangering the longevity of the Hemasite implant and were important causes of implant loss (31% and 6% respectively). Being needleless and painless, the Hemasite was well-accepted by the patients and it functioned well, with adequate blood flow. We conclude that the Hemasite device is a valuable alternative when vascular access becomes a problem in haemodialysis patients.

Adult↗
PubMed1990

The pharmacokinetics of recombinant human erythropoietin after intravenous and subcutaneous administration to healthy subjects.

1. The pharmacokinetics of recombinant erythropoietin, r-Epo, were evaluated after intravenous and subcutaneous administration of 50 u kg-1 to six healthy male volunteers. 2. The calculated mean values (+/- s.d.) for volume of distribution at steady state and clearance after an i.v. dose were 76 (+/- 33) ml kg-1 and 12 (+/- 3) ml h-1 kg-1, respectively. 3. Serum concentrations of r-Epo peaked at 13 (+/- 6) h after the s.c. dose and the bioavailability over 72 h was 36 (+/- 23)%. The mean residence time and half-life of erythropoietin were 6.2 (+/- 1.0) and 4.5 (+/- 0.9) h respectively after i.v. and 46 (+/- 18) and 25 (+/- 12) h after s.c. administration. 4. The results demonstrate the possibility of changing the profile of the concentration-time curve by changing the mode of administration of r-Epo, with implications for the time-course of clinical response.

Adult↗
PubMed1990

Hyperoxaluria or hypercalciuria in nephrolithiasis: the importance of renal tubular functions.

The role of the kidney in states of hyperoxaluria and hypercalciuria was investigated in seven patients with hyperoxaluria after jejunoileal bypass (JIB) and six patients with idiopathic hypercalciuria (IHC). Eight apparently healthy persons formed a control group. Besides hyperoxaluria, the patients with JIB displayed an elevated plasma concentration of oxalate and the oxalate clearance was increased and higher than creatinine clearance, indicating a net tubular secretion of oxalate. The JIB patients had lower 24-h urinary excretions of calcium, phosphate, magnesium and citrate and higher serum parathyroid hormone (PTH) than controls, indicating increased secretion of PTH to compensate for calcium malabsorption. IHC patients exhibited increased fasting urinary calcium even though their serum values were similar to those in the controls. These results indicate a reduced tubular calcium reabsorption, which was most pronounced in patients with highest PTH values. We conclude that hyperoxaluria in JIB patients is associated both with intestinal hyperabsorption and with enhanced tubular secretion of oxalate, and that in some patients with IHC hypercalciuria is due to reduced tubular reabsorption of calcium.

Adult↗
PubMed1990

Pharmacokinetics of intravenous recombinant human erythropoietin in patients with chronic renal failure.

In order to improve our understanding of the dose-concentration and concentration-effect relationships, the pharmacokinetics of recombinant erythropoietin were studied after the initial dose (n = 6) and after repeated doses (n = 9) administered intravenously in patients with chronic renal failure. Several venous blood samples were collected before (to obtain the baseline concentration) and after an intravenous dose of erythropoietin. A radioimmunoassay was used to determine the erythropoietin concentration in the samples. The apparent volume of distribution at steady state was 4.2 +/- 0.91 (initial dose) and 3.7 +/- 0.61 (repeated dosing), which is close to the assumed plasma volume in these patients. The half-life was 5.3 +/- 1.3 h and 5.8 +/- 1.2 h in the two groups, respectively, and is therefore too short for any accumulation to be expected when dosing three times per week. Consequently, no difference in baseline values could be detected between the groups. The clearance of erythropoietin in the groups was estimated to be 11.4 +/- 7.0 ml min-1 and 7.8 +/- 3.8 ml min-1, respectively. Erythropoietin kinetics did not differ after repeated dosing compared to the single initial dose. Intravenous administration of erythropoietin will result in high peak concentrations followed by a rapid decline to basal values.

Adult↗
PubMed1989

Treatment of enteric hyperoxaluria with calcium-containing organic marine hydrocolloid.

An organic marine hydrocolloid (OMH) charged with calcium ('Ox-Absorb') was studied in vitro for oxalate binding and in patients with enteric hyperoxaluria to investigate oxalate excretion and the inhibitory activity on crystal formation of the urine. In-vitro experiments showed complete binding of oxalate to OMH. In clinical studies in nineteen patients with intestinal disorders and stone formation, urinary oxalate excretion was significantly lower during OMH treatment than off treatment. The activity product index of calcium oxalate was reduced on treatment. A pronounced rise in the inhibitory activity of urine was seen in two patients with very low pretreatment values. Most patients experienced virtual normalisation of bowel function, and in those with severe stone formation there was substantial clinical improvement. It is concluded that OMH has the capacity to bind oxalate in vitro and to reduce urinary oxalate excretion. These observations suggest a new promising treatment for enteric hyperoxaluria.

Administration, Oral↗
PubMed1989

Binding of glycosaminoglycan inhibitors to calcium oxalate crystals in relation to ionic strength.

Several inhibitors of calcium oxalate crystallization have been identified and shown to exhibit quantitative and qualitative differences in efficacy. Glycosaminoglycans are potent inhibitors of crystal growth and aggregation, and the efficiency seems to increase with an increasing charge density. In order to investigate the mechanism of inhibition, we performed binding experiments of radioactivity labelled heparin, chondroitin sulphate and the low-molecular mass heparin analogue pentosan polysulphate to calcium oxalate crystals and subsequent displacements by increasing the amounts of non-radioactive ligands or increasing ionic strength. Ligands with a high charge density bound more readily and with a seemingly higher affinity than ligands with a low charge density, but were also more susceptible to displacement when the ionic strength was increased. It is concluded that a higher affinity to the crystals may be the reason why highly charged glycosaminoglycans are more efficient inhibitors of calcium oxalate crystal growth.

Calcium Oxalate↗