Paul Gardner Schmidt

Secondary oxalosis in chronic renal insufficiency.

The concentration of oxalic acid was determined in the plasma of 15 patients with conservatively treated chronic renal insufficiency and 17 dialysis patients. A cumulation of oxalic acid was found in connection with uraemia. The extent to which plasma oxalic acid concentrations were raised depended on the degree of renal insufficiency and was directly related to the plasma creatinine values in all patients with or without dialysis. In the patients with chronic renal insufficiency the median plasma oxalic acid concentration was 74.4-18.5 (control group 27.0 +/- 7.4) mumol/l. In the dialysis patients the levels were even higher, at 137.5 +/- 56.0 mumol. By means of haemodialysis it was possible to lower the plasma oxalic levels by about the same amount as creatinine concentrations. The higher plasma oxalic acid concentrations seem to be an important pathogenetic factor in the formation of uraemic calcification in various organs. The therapeutic consequences are to increase the duration and frequency of dialysis and to remedy possible vitamin B6 deficiency.

Ascorbic acid aggravates secondary hyperoxalemia in patients on chronic hemodialysis.

Excerpt A deficiency in ascorbic acid is found in many patients having chronic hemodialysis treatment, and supplementation is commonly recommended. Ascorbic acid is a metabolic precursor of oxalic ...

Cyclosporin in Wegener Granulomatosis

Excerpt To the editor: The combination of cyclophosphamide and prednisolone is the treatment of choice in Wegener granulomatosis (1). Despite the high remission rate achieved, 7% of the patients (m...

Excessive myocardial calcinosis in a chronic hemodialyzed patient

SummarySecondary oxalosis in chronic hemodialyzed patients is caused by impaired renal excretion and inadequate removal of oxalic acid during hemodialysis. Ascorbic acid is a precursor of oxalic acid. We report a parathyroidectomized patient with chronic renal failure, on hemodialysis, who received over a period of several months a total dose of 91.0 g ascorbic acid i.v. The plasma oxalic acid level in this patient was 14-fold higher than in healthy persons. Increased oxalic acid synthesis from its precursor ascorbic acid may be responsible for hyperoxalemia, high content of oxalic acid in myocardium, aorta and lung, and calcium oxalate deposition in soft tissues. Application of high doses of ascorbic acid should be avoided in hemodialysed patients with chronic renal failure.

Advantages of perfluorochemical perfusion in the isolated working rabbit heart preparation using 31P-NMR.

Quantitative 31P-NMR and enzymatic analysis of high-energy phosphates were used to characterize an isolated perfused working rabbit heart preparation. In this model, the left side of the heart works against a physiological after-load. Two perfusates, Krebs-Henseleit saline and the perfluorocarbon emulsion FC-43 (perfluorotributylamine), were evaluated in their ability to maintain cardiac function and high-energy phosphate metabolites over a period of 2-3 h. Adenine nucleotides ATP, ADP, phosphocreatine and inorganic phosphate (Pi) were measured by 31P-NMR while monitoring cardiac output and coronary flow. Intracellular pH was determined using the chemical shift of Pi. At the end of each experiment, hearts were freeze clamped and enzymatically assayed for adenine nucleotides, phosphocreatine and Pi. In every experiment, hearts perfused with FC-43 emulsion maintained the same rate of cardiac output as hearts perfused with Krebs-Henseleit saline, but with half the coronary flow rate: FC-43, 22 +/- 2.5 (n = 5), Krebs-Henseleit saline 42 +/- 2.7 (n = 6) ml/min, P less than 0.001. Hearts perfused with FC-43 emulsion showed higher [phosphocreatine] and [ATP] measured by 31P-NMR. For [phosphocreatine]: FC-43 3.2 +/- 0.7 (n = 5), Krebs-Henseleit saline 1.7 +/- 0.2 (n = 6) mumol/g wet wt., P less than 0.01. For [ATP]: FC-43 1.8 +/- 0.7 (n = 5), Krebs-Henseleit saline 0.9 +/- 0.2 (n = 6) mumol/g wet wt., P less than 0.02. [phosphocreatine] and [ATP] determined by 31P-NMR values were identical within experimental error to those values obtained by enzymatic analysis. Comparing [Pi] determined by both methods, 36% of Pi in FC-43-perfused hearts, and only 24% of Pi in Krebs-Henseleit saline-perfused hearts were visible by NMR, indicating that a large proportion of Pi is bound in the intact functioning heart. Similar results were obtained for [ADP]. Using the combined techniques of 31P-NMR and enzymatic assay, we have shown in this model of the isolated working rabbit heart preparation, that FC-43 emulsion maintains significantly better function and high-energy phosphate levels than Krebs-Henseleit saline.

Elevated plasma fibronectin levels in nephrotic syndrome

SummaryIn nine patients with nephrotic syndrome the behaviour of plasma fibronectin was studied. Of nine patients seven showed elevated plasma fibronectin levels while the plasma fibrinogen level was increased in eight of the nine investigated patients. A positive correlation was found between plasma fibronectin levels and fibrinogen (P<0.01), cholesterol (P<0.01) and proteinuria (P<0.05). The results indicate that elevated plasma fibronectin levels could be an additional factor responsible for hypercoagulability in nephrotic syndrome.

Die intraerythrozytäre GOT-Aktivität bei Urämie und ihr Verhalten unter Pyridoxinapplikation

A significant decrease of the glutamic oxalacetic transaminase activity of erythrocytes (EGOT) was found in patients on regular dialysis treatment. When pyridoxal-5-phosphate, the active metabolite of vitamin B6, was added to the samples, EGOT activity increased in dialysis patients and in normals, but the activity obtained after stimulation was not as high in haemodialyzed patients as in volunteers. In normals and in patients under pyridoxine treatment the EGOT activity was significantly higher when compared to the corresponding groups without vitamin B6 administration, the EGOT activity depending on duration of pyridoxine treatment.SummaryA significant decrease of the glutamic oxalacetic transaminase activity of erythrocytes (EGOT) was found in patients on regular dialysis treatment. When pyridoxal-5-phosphate, the active metabolite of vitamin B6, was added to the samples, EGOT activity increased in dialysis patients and in normals, but the activity obtained after stimulation was not as high in haemodialyzed patients as in volunteers. In normals and in patients under pyridoxine treatment the EGOT activity was significantly higher when compared to the corresponding groups without vitamin B6 administration, the EGOT activity depending on duration of pyridoxine treatment.

Kupfer, Eisen und deren Trägerproteine (Coeruloplasmin und Transferrin) im Plasma chronisch dialysierter Patienten

SummaryIn 11 chronic dialysis patients the influence of dialysis treatment on copper, iron, ceruloplasmin and transferrin concentrations in the plasma was investigated. Copper and iron were determined photometrically, ceruloplasmin and transferrin by the radial immunodiffusion method. The mean pre-dialysis values of copper and ceruloplasmin were within the upper limit of normal, probably as a possible consequence of copper overloading when using copper-containing dialysis membranes. Low transferrin levels, low latent iron binding capacity and high iron saturation could be due to transfusion haemosiderosis and catabolism. In spite of a considerable copper release from the membrane to the plasma during the first hour of dialysis, there was no significant change in the plasma copper concentration at the end of the dialysis. Ceruloplasmin, transferrin and iron showed a fall in plasma concentrations during dialysis. It can be assumed that lower molecular fractions of ceruloplasmin and transferrin are dialysable.ZusammenfassungBei 11 chronischen Dialysepatienten wurden die Plasmakonzentrationen von Kupfer, Eisen und deren Trägerproteine (Coeruloplasmin und Transferrin) und der Einfluß der Dialysebehandlung auf diese Parameter untersucht. Kupfer und Eisen wurden photometrisch, Coeruloplasmin und Transferrin nach der Radialimmunodiffusionsmethode bestimmt. Der mittlere Kupfer- und Coeruloplasminspiegel lagen im oberen Bereiche der Norm, möglicherweise als Ausdruck einer chronischen Kupferüberladung durch die Verwendung kupferhältiger Dialysatoren. Niedriges Transferrin im Plasma, vermindertes ungesättigtes Eisenbindungsvermögen und erhöhte prozentuelle Eisensättigung waren mit einer Transfusionshämosiderose und einer katabolen Stoffwechsellage in Einklang zu bringen. Trotz einer ausgeprägten Kupferabgabe von der Membran an das Patientenblut in der ersten Dialysestunde kam es zu keiner Änderung des Kupferspiegels im Plasma gegen Ende der Dialyse. Coeruloplasmin, Transferrin und Eisen zeigten einen Konzentrationsabfall im Plasma während der Dialysen. Es wird angenommen, daß niedermolekulare Untereinheiten von Coeruloplasmin und Transferrin dialysabel sind.

Über das Verhalten von Zink im Plasma von Urämikern während Hämodialyse

SummaryPlasma zinc concentrations were determined in 9 patients with chronic renal failure, who were treated by haemodialysis using Twin Coil Travenol ® dialyser. The plasma zine concentration in patients on long-term dialysis program was 261 ± 92 µg-%. This value was considerably higher than an both the control group (108±20 µg-%) and in non-dialyzed chronic renal insufficiency (117±95 µg-%). Dialysis caused an insignificant increase of plasma zinc concentration and a significant increase in the dialysate. It appears likely that the dialysis membrane causes the contamination of both plasma and dialysate.ZusammenfassungBei 9 Patienten mit chronischer Niereninsuffizienz, die im chronisch intermittierenden Hämodialyseprogramm standen, wurden 32 Untersuchungen des Zinkgehaltes im Plasma und in der Spülflüssigkeit während 6 Std Hämodialyse mit Twin-Coil-Travenol ®-Spulen durchgeführt. Die durchschnittliche Zinkkonzentration im Plasma betrug vor Beginn der Dialyse 261±92 µg-% und lag damit deutlich über dem Mittelwert von Normalpersonen von 108±20 µg-% und nicht dialysierten Urämikern 117±15 µg-%. Während der Dialyse kam es zu einem nicht gesicherten Zn-Anstieg im Plasma und zu einer statistisch-signifikanten Zunahme in der Spülflüssigkeit. Als Zn-Quelle wurde die Dialysemembran festgestellt und dann Vergleiche mit anderen Spulen durchgeführt.

Alpha-1-Antitrypsin und Fibrinogenspiegel bei chronischer Niereninsuffizienz und nach Nierentransplantation

SummaryIn ten non dialyzed patients with chronic renal failure, 18 patients on regular dialysis treatment and 70 renal transplant recipients alpha-1-antitrypsin and fibrinogen levels were investigated. Alpha-1-antitrypsin and fibrinogen concentrations were highest in dialyzed patients with values of 314 ± 98 and 485 ± 127 mg/dl respectively. In renal transplant recipients a significant positive correlation between alpha-1-antitrypsin and fibrinogen concentration was found (p < 0.001). High alpha-1-antitrypsin and fibrinogen levels seem to be a possible consequence of reactive processes due to underlying disease or complications. Our results seem to indicate that both α1-antitrypsin and fibrinogen can be classified as “acute phase protein”.ZusammenfassungAlpha-1-Antitrypsin und Fibrinogenspiegel wurden bei zehn nichtdialysierten Patienten mit chronischer Niereninsuffizienz, 18 Dialysepatienten und 70 Nierentransplantierten untersucht. Die höchsten α1-Antitrypsin- und Fibrinogenwerte boten Dialysepatienten mit 314 ± 98 bzw. 485 ± 127 mg/dl. Bei nierentransplantierten Patienten bestand eine signifikante positive Korrelation zwischen α1-Antitrypsin und Fibrinogenkonzentrationen (p < 0,001).Hohe α1-Antitrypsin und Fibrinogenwerte könnten wahrscheinlich Ausdruck von reaktiven Prozessen im Rahmen der Grunderkrankung oder Komplikationen sein. Die Untersuchungsergebnisse scheinen zu beweisen, daß sowohl α1-Antitrypsin als auch Fibrinogen als „Akutphasenproteine“ angesehen werden können.