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Biomedical subjects

M Molzahn

Publications and source records attributed to M Molzahn.

At least 55 records · Page 3Linked to original sources
PubMed1984

Carpal tunnel syndrome: a major complication in long-term hemodialysis patients.

One hundred and forty-five patients on hemodialysis for periods of 1 month to 16 years were examined clinically for carpal tunnel syndrome (CTS). Typical symptoms and clinical manifestations of symptomatic CTS, either unilaterally or in both hands, were detected in 21 of these patients (15%). In contrast to the classic form of CTS, hemodialysis CTS in our patients was frequently accompanied by Raynaud's phenomenon of those digits supplied by the median nerve. A highly significant correlation was established between the incidence of CTS and the duration of dialysis (p less than 0.001). The association of CTS with analgesic nephropathy was significantly higher (52%) than with other kidney diseases (p less than 0.034). Immediate relief of pain was achieved after carpal tunnel release (11 releases) in 8 of the 21 patients. Sensory and motor function was gradually, but often only partially, restored. Unoperated CTS progressed to loss of sensory and motor function within 1 to 4 years after the onset of symptoms. CTS should be considered a major late complication in patients on chronic hemodialysis.

Adult↗
PubMed1984

Effect of repeated plasma exchange on steady state kinetics of digoxin and digitoxin.

The effect of repeated plasma exchanges on the steady state kinetics of digoxin (3 patients) and digitoxin (4 patients) was investigated in 7 patients. Plasma exchange was performed 3 times a week for 4 weeks up to 12 exchanges using a hollow fiber membrane. In each exchange, 4000 ml plasma were filtered within 1 to 2 h and replaced by an albumin containing (20 g/l) physiological electrolyte solution. Digoxin and digitoxin concentrations in blood and filtered plasma were measured by radioimmunoassay. The effects due to the amount eliminated by plasma exchange were distinguished from the effects due to hypoalbuminemia. The eliminative effect was confined to the plasma compartment. It resulted in a marginal decrease in the elimination half-life from 1.6 to 1.59 days for digoxin and 4.3 to 4.2 days for digitoxin. Theoretically, it can be calculated that the hypoalbuminemia caused an increase in the volume of distribution from 451 to 497 l (digoxin) and 35 to 50 l (digitoxin) and a further decrease in the elimination half-life from 4.2 to 4.1 days in the case of digitoxin (not digoxin). If given within 2 h prior to plasma exchange, 13 to 50% of the digitoxin dose (not digoxin) was eliminated. Alteration of digoxin and digitoxin dosage during repeated plasma exchanges is not recommended, but drugs should be given after, not before plasma exchange.

Adult↗
PubMed1983

Elimination kinetics of plasma exchange.

Interest in the therapeutic use of plasma exchange for various diseases is growing. The two different effects of plasma exchange are elimination and activation. The kinetics are linear for elimination by plasma exchange, but not for activation. Plasma exchange is performed intermittently and can be described by intermittent kinetics. According to intermittent kinetics, plasma exchange removes 50% to 75% of a substance in plasma within 1-2 h, corresponding to an elimination half-life of 30-40 min. Hybrid kinetics, a mixture of actually intermittent but theoretically continuous elimination by plasma exchange, can however also be applied. Hybrid kinetics are more convenient and more reliable than intermittent kinetics. This is because hybrid kinetics are based solely on the concentrations before each plasma exchange; hybrid kinetics also reflect removal from the entire body and not just from the plasma compartment. According to hybrid kinetics, the amount of a substance in the body removed within 3-4 days is 50% of the difference between the initial and the final plasma concentration, depending on the intensity of plasma exchange. The intensity may well contribute at least in part to the beneficial effect of plasma exchange in various diseases.

Antibodies↗
PubMed1983

[Acute interstitial nephritis caused by drugs].

Within 30 months the diagnosis of drug-induced acute interstitial nephritis was made in ten patients with acute onset of renal failure of clinically unknown cause. Allergenic substances were discovered to be antibiotics, pyrazol and indol derivatives, piromidic acid and chlorazanil. In contrast to the known course of methicillin nephritis the clinical signs were undramatic. Non-oliguric renal failure predominated, sometimes with leucocyturia, microhaematuria and moderate proteinuria. Intermittent haemodialysis was necessary in half the cases. Renal function developed favourably without further specific treatment, however, plasma creatinine did not return to normal levels in most cases. Percutaneous renal biopsy was the definitive diagnostic step. Indications for biopsy in cases of unclear acute renal failure should thus be handled liberally in order to prevent continued drug exposure with the danger of irreversible renal failure.

Acute Disease↗
PubMed1983

Effect of primary renal disease and risk factors on kidney graft survival.

The important role of immunological factors, HLA typing and pretransplant blood transfusion on improved kidney graft survival is well established. Additionally, graft survival depends on risk factors such as diabetes and age of the recipient. The effect of other clinical risk factors on graft survival was evaluated in 187 patients who received kidney transplants at our centre between 1970 and 1981. Graft survival according to the life table method and statistical analysis according to the logrank test revealed 4 main risk factors. Graft survival is significantly lower in type I diabetics and analgesic nephropathy, whereas it is better in hereditary and other renal diseases. Additional risk factors are coronary heart disease and repeated grafting. Time of dialysis before transplantation and age of the recipient showed no detrimental effect on graft survival.

Adult↗
PubMed1983

[Acute kidney failure in secondary renal oxalosis. Additional indications for a causal connection to xylitol infusions].

A 35 years old female developed a slowly progressive acute renal failure after surgical drainage of a pancreatic abscess. Due to the uncharacteristic course a renal biopsy was performed which revealed a severe obstructive renal oxalosis with concomitant interstitial nephritis. Primary oxalosis was excluded by determination of glyceric and glycolic acid in the urine. Since other preconditions for increased oxalate formation were not present it was considered as an adverse reaction to the parenteral application of xylitol. During 4 weeks of total parenteral nutrition the patient received this sugar alcohol in a dose of 3.0 g/kg/day (total dose 4480 g). In recognition of preceding autopsy studies and recent experimental investigations on the metabolic pathways from xylitol to oxalate the chances and conditions of renal deposition of calcium oxalate after administration of xylitol are discussed.

Acute Kidney Injury↗
PubMed1983

Effect of plasma protein binding, volume of distribution and molecular weight on the fraction of drugs eliminated by hemodialysis.

The correlation between plasma protein binding, the volume of distribution, molecular weight, and percentage removed by hemodialysis was investigated in 89 drugs using information available in the literature. The correlation was significantly linear between dialyzability and plasma protein binding, as well as with the reciprocal volume of distribution. This is in agreement with the theoretical deduction of dialyzability from diffusion and convection kinetics. Multiple linear regression analysis revealed that only 27% of the variance in dialyzability could be explained by plasma protein binding (17%), the volume of distribution (6%), and the molecular weight (4%) of the drugs. Therefore, the dialyzability of drugs can not be predicted reliably.

Blood Proteins↗
PubMed1982

[Long-term results after kidney transplantation].

In this investigation, our own long-term results after kidney transplantation were compared with those in literature, and the influence of recent findings on the survival rate of patients and transplants was analyzed. In 217 kidney transplant patients, the 5 and 9-year-patient survival rate was calculated at 58% and 45% respectively. The 9-year-transplant function rate was 38%. Analogous results can be derived from collective international and European statistics. The long-term patient survival rate after successful transplantation shows better results than comparable statistics of hemodialysis treatment. Analysis of the results fractionated into the years 1970 to 1974, 1975 to 1977 and 1978 to 1981 shows a continuous improvement in the survival rate of patients and transplants. This improvement of results can be attributed to the reduction of surgical complications with increasing experience and particularly to knowledge recently gained in the field of transplantation immunology (compatibility in the HLA-A/B and -DR system, preoperative blood transfusions) and immunosuppression (reduction of steroid doses, supplementary ATG and cyclosporin A medication).

Adult↗
PubMed1982

Influence of prostaglandins A1, E1, E2, and F2 alpha on renal blood flow and plasma renin activity. Investigations in chronically instrumented conscious dogs.

The effects of different prostaglandins (PG) on serial determination of renal blood flow (RBF), mean arterial blood pressure (MABP), renal vascular resistance (RVR) and renin release were investigated in the conscious, chronically instrumented dog. 2 months after right-sided nephrectomy, female beagle dogs (n = 6) were implanted with an electromagnetic flow probe and an inflatable pneumatic cuff around the left renal artery, and a catheter was inserted into the aorta above the renal artery. In repeated experiments, different prostaglandins (PGA1, E1, E2 and F2 alpha) were infused above the renal artery at increasing doses (infusion time 15 min, doses 0.03--1.0 micrograms min-1 kg-1). Lower and medium doses induced an increase of RBF, which returned to or were slightly below control levels with higher doses. PGA1 appeared to be the most potent vasodilator with a significant hypotensive activity and the greatest augmentation of RBF. Simultaneously, renin release was most pronounced by PGA1.

Animals↗
PubMed1981

Pharmacokinetics of oxazepam following multiple administration in volunteers and patients with chronic renal disease.

The plasma level course and the elimination of oxazepam (Adumbran) via urine were investigated following multiple oral administration in volunteers and patients with chronic renal failure. Additionally, drug metabolizing enzyme systems had been induced in the volunteers by pretreatment with phenobarbital. The plasma protein binding in vitro of oxazepam was determined in volunteers and patients. The plasma levels and the renal elimination of oxazepam and its metabolites do not show any differences between the two groups of volunteers (oxazepam and oxazepam after pretreatment). 83--92% of the dosage are eliminated via urine. In comparison, the plasma levels of oxazepam in patients with renal failure are half those of the volunteers. However, the plasma levels of oxazepam metabolites in patients are much higher than in volunteers and these increases correlate to the creatinine clearance of the patients. The non-protein bound oxazepam in plasma was found to be twice as high in the plasma of patients as that of volunteers. As a consequence, the lower plasma level of oxazepam in patients will be compensated for so that the pharmacological activity in patients and volunteers due to free oxazepam in the plasma water is nearly the same. Therefore a new dosage regimen for treatment with oxazepam in patients with renal failure is not necessary.

Adult↗
PubMed1980

Digoxin dosage in renal insufficiency: impracticality of basing it on the creatinine clearance, body weight and volume of distribution.

Previous dosing schedules for digoxin in renal failure have considered the decrease in the elimination rate constant but not the decrease in the volume of distribution. A dosing schedule based on the creatinine clearance, body weight and volume of distribution has been developed from pharmacokinetic data taken from the literature. Its validity was tested in a clinical study of 35 patients with chronic renal insufficiency not requiring dialysis. The dosing schedule resulted in correct digitalization expressed as a steady state plasma digoxin concentration in the therapeutic range (0.5-2.0 ng/ml) in 25 out of 27 patients (93%). However, of 82 possible candidates for the study, it could not be performed in 47 (57%). The high drop-out rate was mainly due to the complicated dosing schedule and to the difficulty of repeatedly measuring creatinine clearance on a routine basis. Therefore, safe dosing of digoxin in renal insufficiency does not seem to be feasible in practice. Digitoxin may be a better alternative.

Adult↗
PubMed1980

Blood pressure in terminal renal failure. Fluid spaces and the renin-angiotensin-system.

Most of the 52 patients on maintenance dialysis investigated in this study suffered from arterial hypertension in spite of efforts to reduce 'dry weight'. In this situation we found that the majority of patients were underweight and that total body water, extracellular volume and blood volume were close to normal when related to reference systems consisting of height and age. Hypertensive patients were not volume expanded as compared to normotensive patients and controls. Plasma renin activity and angiotensin II were elevated in a few patients, with a trend to higher levels in the more hypertensive patients. Various approaches attempting to correlate blood pressure and the respective volume-renin factors did not prove to be conclusive in explaining the maintenance of hypertension in chronic renal failure on the basis of the sodium-renin feedback.

Adult↗
PubMed1980

Gastrointestinal protein loss in the nephrotic syndrome studied with 51Cr-albumin.

Gastrointestinal protein loss was studied by intravenous application of 51Cr-albumin and the measurement of fecal excretion of 51Cr. As compared to controls, fecal excretion of 51Cr was largely increased in 28 patients with nephrotic syndrome due to glomerular disease and in 11 patients with hypoproteinemia in the course of different gastrointestinal disorders. It was not increased in nephrotic patients without primary glomerular disease and in renal insufficiency without nephrotic syndrome. Controversial data of the literature are discussed with regard to different methods and patient groups.

Adult↗