Qualitätsindikatoren und strukturelle Voraussetzungen für Cardiac-Arrest-Zentren – Deutscher Rat für Wiederbelebung/German Resuscitation Council (GRC)

Notfall + Rettungsmedizin -     

Clinical and experimental effects of medium-chain-triglyceride-based fat emulsions--a review

Although total parenteral nutrition usually includes lipids, traditional long-chain triglyceride (LCT) emulsions do not fulfil the energy-providing role allotted to them. The special properties of medium-chain triglycerides (MCTs) and fatty acids led to replacement of part of the infused LCTs by MCTs. The present review shows that:     

High haemodialysis clearance of ornidazole in the presence of a negligible renal clearance

Summary The pharmacokinetics of ornidazole was studied in 6 patients treated by haemodialysis and in 8 subjects with a creatinine clearance between 4 and 99 ml/min × 1.73 m². Blood and urine collections were performed for 72 h after i.v. and oral administration of 1.0 g ornidazole.Total body clearance, half-life, volume of distribution and systemic availability were independent of renal function and did not differ from previously reported values in normal volunteers. The haemodialysis clearance of ornidazole was >100% higher than the total body clearance. The renal clearance of ornidazole accounted for less than 7% of the total body clearance. The percentage of the dose of ornidazole recovered in urine as parent compound or as the biologically active metabolites [-(chloromethyl)-2 hydroxymethyl-5 nitroimidazole-1 ethanol and 3-(2 methyl-5 nitroimidazole-1-yl)1,2 propanediol] decreased linearly with decreasing renal function.Although the sum of those three compounds recovered in urine accounted for less than 10% of the total dose of ornidazole administered, they yielded therapeutic concentrations (>4 µg/ml) in urine over 24 h after dosing.Due to the peculiar pharmacokinetic behaviour of ornidazole, i.e. high haemodialysis clearance in the absence of significant renal clearance, no dosage adjustment is necessary while renal function declines, but an increased dose is mandatory while patients are on dialysis.     

Nonlinear plasma protein binding and haemodialysis clearance of prednisolone

Summary The impact of nonlinear plasma protein binding of a drug on its removal by haemodialysis has been quantified. Prednisolone 10–100 mg was given i.v. to 10 renal transplant patients on haemodialysis for acute tubular necrosis. Dialysate and afferent and efferent blood samples were collected simultaneously in 67 instances. Total and unbound prednisolone in plasma and its total concentration in blood and dialysate were assessed by high performance liquid chromatography and equilibrium dialysis. The amount of prednisolone lost, as measured directly in the dialysate (21.8±4.4 µg/min, ± SE), was predictable from the afferent-efferent blood concentration differences (20.1±4.8 µg/min), but not from measurements of total afferent-efferent prednisolone concentrations in plasma (13.1±3.0 µg/min). The amount of prednisolone lost in the dialysate increased linearly with unbound (r ²=0.96) and hyperbolically with the total prednisolone concentration in plasma. The latter hyperbolic relationship is adequately described by the equation for nonlinear plasma protein binding, using the affinity and capacity constants of albumin and transcortin for prednisolone (r ²=0.98). Thus, the haemodialysis clearance of total prednisolone is concentration-dependent, while the clearance of unbound prednisolone is constant (76 ml/min). Free clearance values or measurements of afferent-efferent blood concentrations are mandatory for a drug showing nonlinear plasma protein binding in order to predict the amount lost in the dialysate.Abbreviations Used C_Ba Afferent blood concentration [ng/ml] - C_Be Efferent blood concentration [ng/ml] - C_D Dialysate concentration [ng/ml] - C_Pa Afferent plasma concentration [ng/ml] - C_PaFree Free concentration of prednisolone in afferent plasma [ng/ml] - C_Pe Efferent plasma concentration [ng/ml] - CAP_A Binding capacity of albumin [µg%] - CAP_T Binding capacity of transcortin [µg%] - Cl_B Blood clearance [ml/min] - Cl_Free Free plasma clearance [ml/min] - Cl_P Plasma clearance [ml/min] - H_a Haematocrit in afferent blood - H_e Haematocrit in efferent blood - K Partition coefficient between red blood cells and plasma - KD_A Dissociation constant of albumin (M/L) - KD_T Dissociation constant of transcortin (M/L) - Q_B Blood flow [ml/min] - Q_D Dialysate flow [ml/min] - Q_F Flow of ultrafiltrate [ml/min] - t₁ First sampling time point after haemodialysis started - t₂ Last sampling time point before haemodialysis was discontinued - Z_Ddi Loss of prednisolone in the dialysate by diffusion [µg/min] (Z indicates calculated for each sampling time point) - _Ddi Mean loss of prednisolone in the dialysate by diffusion [µg/min] ( indicates calculated for the entire haemodialysis period) - Z_Dtot Total amount of prednisolone recovered in the dialysate [µg/min] - _Dtot Mean total amount of prednisolone recovered in the dialysate [µg/min] - Z_Du Loss of prednisolone in the dialysate by ultrafiltration [µg/min] - _Du Mean loss of prednisolone in the dialysate by ultrafiltration [µg/min] - Z_cB Amount of prednisolone lost in the dialysate calculated from afferent-efferent blood concentrations [µg/min] - _cB Mean amount of prednisolone lost in the dialysate calculated from afferent-efferent blood concentrations [µg/min] - Z_cP Amount of prednisolone lost in the dialysate calculated from afferent-efferent plasma concentrations [µg/min] - _cP Mean amount of prednisolone lost in the dialysate calculated from afferent-efferent plasma concentrations [µg/min] - Z_cPK Amount of prednisolone lost in the dialysate calculated from afferent-efferent plasma concentrations corrected by the partition coefficient [µg/min] - _cPK Mean amount of prednisolone lost in the dialysate calculated from afferent-efferent plasma concentrations corrected for the partition coefficient [µg/min] Abstract presented to the American Society of Nephrology, Washington, 1981     

Versuche über die Art des Herzschlages und der Herznervenwirkung

Ohne Zusammenfassung Abgeschlossen Juli 1923.     

Der Einfluß der Saponine auf die männlichen Sexualhormone

Zusammenfassung Digitonin, ein Saponin der Cholanreihe, und Guajakrindensaponin, ein solches der Triterpenoidgruppe, wurden kastrierten männlichen Ratten gleichzeitig mit den Sexualhormonen eingegeben und nach fünftägiger Behandlung das Gewicht von Prostata und Samenblasen festgestellt. Dabei hemmte Digitonin die Wirkung von Erugon, das die drei männlichen Sexualhormone enthält, das Androsteron, das Dehydroandrosteron und das Testosteron; gleichzeitige Gaben von Guajakrindensaponin hoben die Wirkung von Erugon fast ganz auf. — Gegenüber dem Androsteronbenzoat, dem Proviron, erwiesen sich die Saponine als wirkungslos. —Das an sich schon starke Wachstum von Prostata und Samenblasen nach Testoviron, dem Testosteronpropionat, wurde durch Digitonin und Guajaksaponin noch weiter gesteigert, so daß Gewichte vorkamen, die fast zehnmal so groß waren als die der Organe von Kontrollen. Dabei begünstigte Testosteron besonders das Wachstum der Samenblasen.     

Berichtüber eine seltene Abnormität am menschlichen Amboss

Ohne Zusammenfassung     

Calcium-induced long-term potentiation in the hippocampal slice: Characterization of the time course and conditions

A transient increase in extracellular calcium concentration causes a long-lasting enhancement of radiatum fibers evoked excitatory postsynaptic potential and population spike responses of CA1 pyramidal neurons which resembles long-term potentiation (LTP). The duration of this potentiation is much longer than described previously and is probably limited by the survival of the preparation itself (greater than 8 hr). Therefore, Ca-induced LTP can be used for the investigation of a postulated late phase of LTP. Ca effects were activity-independent, since the subsequently evoked responses were facilitated even when the presynaptic fibers were not concurrently stimulated during or immediately after superfusion with the high Ca medium. In contrast, if too frequent testing of the synaptic input was done during the high Ca pulse, a short lasting depression instead of potentiation was observed. A lower extracellular magnesium concentration in the standard medium (1.3 instead of 2.0 mM MgSO4) prevents the potentiation of the EPSP at least for the first few hours. Presumably, both tetanus- and Ca-induced LTP share some common mechanisms, since an additional tetanization after Ca induction was not followed by an additional LTP. Compared to the potentiation following tetanization, the Ca-induced LTP was, however, not accompanied by a potentiation of the EPSP/spike ratio within the range of the population spike threshold intensity.