[Occlusion of the inferior vena cava--a rare, but severe disease picture, easily diagnosed with ultrasound]. / Verschluss der Vena cava inferior--ein seltenes, jedoch schwerwiegendes Krankheitsbild, leicht durch Ultraschall zu diagnostizieren.

Vena cava inferior thrombosis can occur in many disease patterns. In the literature the vena cava inferior thrombosis is described in several case reports. Thrombosis of the vena cava inferior often leads to pulmonary embolism and influences the prognostic and therapeutic way definitively. This is important in the case of a real thrombus and also for "thrombotic tumorous material", which is not differentiated in the literature. Even if the pattern of a vena cava inferior thrombosis is very rare (in our patients 1%), early and safe diagnosis is very important. Abdominal ultrasound supplies a definitive clue to the diagnosis. The high diagnostic ranking in comparison to other imaging techniques is discussed. This is a definitive imaging technique which influences the therapeutic concept and prognosis.

Pharmacokinetics of isosorbide dinitrate, isosorbide-2-nitrate and isosorbide-5-nitrate in renal insufficiency after repeated oral dosage.

The pharmacokinetics of isosorbide dinitrate (ISDN) and its two active metabolites isosorbide-2-nitrate (IS-2-N) and isosorbide-5-nitrate (IS-5-N) were studied in 20 patients with normal and impaired renal function after repeated oral doses of standard 20 mg tablets ISDN t.i.d. Blood samples were taken in the steady-state on days 2 and 14, and the plasma concentrations were measured by electron capture capillary gas chromatography. We found a wide variation of pharmacokinetic parameters (AUCss0-8 and t1/2) of ISDN, IS-2-N, and IS-5-N in our patients. No correlation was detected between AUCss0-8 or t1/2 and the degree of renal insufficiency. No drug accumulation was observed after 14 days of administration.

Pharmacokinetics of isosorbide-5-nitrate during haemodialysis and peritoneal dialysis.

The pharmacokinetics of isosorbide-5-nitrate (IS-5-N) was studied in ten patients on haemodialysis (HD) after a single oral dose of 20 mg IS-5-N, and in six patients on continuous ambulatory peritoneal dialysis (CAPD) after repeated oral doses of 3 X 20 mg IS-5-N. There was significant removal of IS-5-N from blood during HD; Cmax decreased by about 20%, AUC(0-8 h) by 30% and t1/2 by about 20% from 4.3 to 3.4 h, and plasma clearance was increased by 81 ml/min. No important loss of IS-5-N was observed in patients on CAPD.

Pharmacokinetics of isosorbide-5-nitrate in renal failure.

The pharmacokinetics of the antianginal drug isosorbide-5-nitrate (IS-5-N) was studied in 20 patients with varying degrees of chronic renal failure after repeated oral doses of standard 20 mg tablets t.d.s. Blood samples were taken in the steady state on the 2nd and 28th days, and the plasma level was assayed by HPLC. There was no statistically significant difference in Cssmax, t1/2 and AUCss0-8 between the 2nd and 28th days, nor was a difference found between patients with mild and severe renal failure.

[Oxygen tension in skeletal muscle in patients with reduced O2-carrying capacity (author's transl)]. / Der Sauerstoffdruck in der Skelettmuskulatur bei Patienten mit chronisch herabgesetzter O2-Kapazität.

In 10 patients (age: 31--72 years) oxygen supply of skeletal muscle was measured by pO2-multiwire technique. All patients suffered from chronic renal failure of differing etiologies and from chronic renal anemia. In muscle tissue 1,128 different O2-tensions were registered and the results were expressed as pO2-histograms. Seven of these pO2-histograms show a normal distribution, three are shifted to the left to lower O2-tensions. Therefore the microcirculation in the skeletal muscle of patients with chronic reduced O2-carrying capacity is largely undisturbed. The microcirculation is able to increase with exercise as shown by a shift to the right in the PO2-histogram. The use of the pO2-multiwire electrode is largely devoid of risk to the patient. Important pathological features may be demonstrated.

[Atrial versus ventricular cardiac pacing in the elderly with respect to hemodynamic data (author's transl)]. / Differentialtherapie bradykarder Herzrhythmusstörungen mit permanenter atrialer oder ventrikulärer Schrittmacherstimulation unter Berüchsichtigung der Hämodynamik.

The importance of synchronized atrial and ventricular action is well known. Especially in elderly patients the circulation of the brain, the kidneys and the coronary arteries may be diminished by ventricular stimulation. Permanent atrial, atrial triggered ventricular, and bifocal stimulation increases cardiac output by 20-30 percent. From the hemodynamic data the best results during atrial stimulation are obtained at a frequency of 80 to 85 bpm.

[Erythropoietin in serum and urine in healthy persons and patients with chronic renal disease upon hypoxic stimulation and hypoxic stimulation after pretreatment with fluoxymesterone (author's transl)]. / Erythropoetin (ESF) im Serum und Harn bei chronisch Nierenkranken und Gesunden unter hypoxischer Stimulation und hypoxischer Stimulation nach Androgengabe (Fluoxymesteron).

The question of a latent erythropoietin (ESF)-deficiency was studied in incipient renal anemia using a double stimulation technique for ESF. After a 4-week stimulation of ESF production with oral administration of fluoxymesterone (flu) intermittent hypoxic ESF stimulation was performed corresponding to a maximum altitude of 4000 m in 7 patients with chronic renal disease without or with incipient renal anemia (mean hematocrit 40%) and in 11 normal subjects (mean hematocrit 46%). Double stimulation in patients was compared with hypoxic stimulation alone and both were compared with controls. After flu alone only ESF excretion was increased in patients and in normal subjects. After flu plus 10 h of hypoxia serum ESF--titers were higher in healthy subjects than in the patients. The mean ESF titer after double stimulation was 81 mU/ml in patients and 115 mU/ml in normal persons. Forty-eight hour ESF excretion was 11 U and 43 U respectively. Compared to hypoxic stimulation alone double stimulation increased serum ESF titers in patients by 5% versus 80% in controls. Correspondingly, ESF excretion was enhanced by 19% and 49%, respectively. Finally, renal ESF clearance was increased by 42% versus 200%. After hypoxia alone non-anemic patients had higher serum ESF titers than healthy controls excluding a latent ESF deficiency in incipient renal anemia. It is concluded that decreased ESF production after double stimulation in patients was due to a nephrotoxic effect of flu followed by a decreased excretory and ESF-producing function of the damaged kidneys.

Investigations on Leydig cell function and regulation after renal transplantation.

The hypothalamic-hypophyseal-Leydig cell axis was investigated in 17 male patients following renal transplantation. Plasma levels of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were determined by radioimmunoassay under basal conditions and after stimulation with chorionic gonadotrophin (HCG) and hypothalamic releasing hormone (LH/FSH-RH) respectively. The investigations were carried out one to five years after renal transplantation. It was demonstrated, that primary dysfunction of Leydig cells may occur after renal transplantation. In some cases however normal Leydig cell function with adequate testosterone secretion may return. It remains uncertain, whether the Leydig cell dysfunction is a result of preexisting toxic uremic damage or whether it is due to immunosuppressive therapy with prednisone and azathioprine.