Anemia and carnitine supplementation in hemodialyzed patients.

Carnitine supplementation in hemodialyzed patients was studied in a double-blinded, randomized, controlled trial in order to elucidate the effect of intravenous carnitine on renal anemia in patients treated with recombinant human erythropoietin (rHuEPO). Twenty stable hemodialysis (HD) patients received intravenous L-carnitine after each dialysis session in a dosage of 5 (N = 15) and 25 (N = 5) mg/kg, respectively, together with intravenous iron saccharate (20 mg/HD session) for four months and without iron for a further four months. Twenty patients received placebo instead of carnitine with an identical iron regimen. After a run-in phase of six months with a stable rHuEPO requirement, the rHuEPO dose was adjusted monthly when necessary to maintain target hemoglobin levels. At study entry (T0), plasma and red blood cell carnitine levels did not correlate significantly with the rHuEPO requirement. However, plasma free and total carnitine levels showed a significant negative correlation with erythrocyte survival time at T0. After four months of coadministration of intravenous iron and L-carnitine (T4), the rHuEPO requirement decreased in 8 of 19 evaluable HD patients. In these responders, the weekly rHuEPO dose was decreased significantly by 36.9+/-23.3% (183.7+/-131.7 at T0 vs. 126.6+/-127.9 U/kg/week at T4, P < 0.001). The rHuEPO requirement, however, was unchanged when all carnitine-treated patients were compared between T0 and T4 (T0: 172.0+/-118.0 vs. T4: 152.3+/-118.8 U/kg/week, P = 0.07, NS), but the erythropoietin resistance index decreased significantly in this group (T0: 16.0+/-11.0 vs. T4: 13.6+/-10.5 U/kg/week/g of hemoglobin, P < 0.02). The erythrocyte survival time was measured in five HD patients treated with iron and carnitine at T0 and T4. Two out of these patients were carnitine responders and showed an increase of erythrocyte survival time of 15 and 20%, respectively. After the withdrawal of iron supplementation, the rHuEPO requirement increased comparably in both L-carnitine- and placebo-treated patients during four more months. According to our data, L-carnitine, in addition to iron supplementation, may have an effect on erythropoietin resistance and erythrocyte survival time in HD patients. More than half of our patients, however, showed no benefit. Further studies to identify those HD patients who might have a benefit of carnitine supplementation, as well as studies concerning the optimal dosage, duration, and way of administration of carnitine supplementation and its mechanism of action, are required.

Glomerular basement membrane changes, HbAIc and urinary excretion of acid glycosaminoglycans in children with diabetes mellitus.

Glomerular basement membrane antigens excreted into urine, urinary acid glycosaminoglycans and hemoglobin AIc plasma levels were estimated in 18 diabetic children. In comparison to controls we detected significant differences, in that diabetics with changed (alpha-1-) mobility on immunoelectrophoresis revealed increased urinary acid glycosaminoglycan excretion (p less than 0.01) and elevated HbAIc concentrations in plasma (p less than 0.01). HbAIc levels and urinary glycosaminoglycans correlated significantly (r = 0.7, p less than 0.001). Increased glycosaminoglycans as well as increased blood glucose reflected by elevated HbAIc could lead to the biochemical glomerular basement membrane changes found on immunoelectrophoresis. The results suggest a metabolic hypothesis for the development of diabetic glomerulopathy.

Effects of hypolipidaemics cetaben and clofibrate on mitochondrial and peroxisomal enzymes of rat liver.

Clofibrate or cetaben was administered to male rats for 10 days. Peroxisomal and mitochondrial enzymes were assayed in liver subcellular fractions. Clofibrate affected the specific activities of both mitochondrial enzymes (glycerol-3-phosphate dehydrogenase and nicotinamide-linked isocitrate dehydrogenase) and peroxisomal enzymes (fatty acyl-CoA oxidase, glycerone phosphate acyltransferase, urate oxidase, and D-amino-acid oxidase). In contrast, cetaben raised only the peroxisomal enzymes, acyl-CoA oxidase, glycerone-phosphate acyltransferase, D-amino-acid oxidase, catalase, and urate oxidase. Thus, the hypolipidaemic activity of these drugs may be exclusively related to stimulated peroxisomal functioning, while mitochondria play only a minor role.

[Serum concentrations of tissue polypeptide antigen and alpha 1-fetoprotein in patients with primary liver cancer, liver metastasis and liver cirrhosis]. / Serumkonzentrationen von Tissue Polypeptide Antigen und alpha 1-Fetoprotein bei Patienten mit primärem Leberkarzinom, Metastasenleber und Leberzirrhose.

Tissue Polypeptide Antigen (TPA) and alpha 1-fetoprotein (AFP) were determined in sera of 21 patients with hepatocellular carcinomas, in 20 patients with extrahepatic carcinomas and metastases of the liver, as well as in 26 patients with cirrhosis of the liver. TPA was increased (greater than 85 U/L) in all patients with malignant hepatomas, in 80% of patients with metastatic liver cancer and in 35% of patients with cirrhosis of the liver. The critical serum TPA level, above which only malignant liver tumours lay, was statistically evaluated and found to be 187 U/L. All patients with benign liver disease and half of the patients with metastatic liver disease showed TPA values lower than 187 U/L. All of the patients with hepatocellular carcinoma and half of the patients with metastatic liver cancer had TPA values greater than 187 U/L; all of our patients with cirrhosis of the liver, as well as half of the patients with metastatic liver cancer had lower TPA values. 86% out of all hepatoma patients showed increased AFP levels (greater than 9 ng/ml), whereby the AFP concentrations were in the range which is highly suggestive of hepatoma (greater than 174 ng/ml) in 67% of all patients with malignant hepatomas. Patients with metastatic liver cancer and cirrhosis of the liver had AFP levels lower than 174 ng/ml AFP. TPA is an unspecific tumour marker, which can be used together with AFP in the diagnosis of unclear defects in liver parenchyma, in supervision of cirrhosis, as well as in control assessment during chemotherapy or after tumour resection.

[Serum concentrations of alpha-1-fetoprotein suggestive of, or pathognomonic for hepatoma (author's transl)]. / Hepatom-suspekte und -pathognomonische Serumkonzentrationen von alpha-1-Fetoprotein.

A short review of alpha-1-fetoprotein (AFP), is followed by a presentation of the serum AFP concentrations obtained in healthy subjects and in patients with hepatoma, cirrhosis of the liver or metastatic liver cancer, measured by radioimmunoassay (RIA). A calculation is made from these results of the upper limit of normal (9 ng/ml), a limit which is suggestive of hepatoma (215 ng/ml) and a limit which is pathognomonic for hepatoma (7500 ng/ml). It is concluded that the quantitative determination of AFP by RIA represents a sensitive method which provides valuable clinical information for the early diagnosis of hepatoma.

[External quality assurance: a significant--and 25-year-old--element of quality management in the medical diagnostic laboratory]. / Externe Qualitätssicherung: Ein wesentlicher--und seit 25 Jahren existenter--Bestandteil des Qualitätsmanagements im medizinisch-diagnostischen Laboratorium.

An external quality assurance system in the medical diagnostic laboratory, which is an essential part of the modern total quality management (TQM) concept in the public health system, was established in Austria already 25 years ago. The development and the scope of this quality assessment system by the "Austrian Society for Quality Assurance and Standardization of Analyses in the Clinical Laboratory" (OQUASTA) are presented. The decreasing coefficients of variation of several parameters of the external quality assessment exercises demonstrate an increasing analytical precision and might be interpreted as an effect of this quality assurance system.

[Non-enzymatic glycosylation of hemoglobin and serum protein in children with galactosemia]. / Nichtenzymatische Glykosylierung von Hämoglobin und Serumprotein bei Kindern mit Galaktosämie.

Non-enzymatic galactosylation has been investigated by in vitro incubation of red cell haemolysate, a HbAo-preparation and of GBM of healthy children. The effects of non-enzymatic galactosylation of haemoglobin has been studied by high pressure liquid chromatography, the effects of GBM galactosylation by immunoelectrophoresis. Subsequently, the occurrence of elevated values for HbAIa-c and GSP was evaluated in 14 galactosaemic children (11 transferase deficiency, 3 galactokinase deficiency), as well as urinary acid glycosaminoglycae excretion and GBM immunoelectrophoretic mobility in 6 of these 14 children measured. The results were compared to the respective values of healthy control children. After exclusion of significant non-enzymatic glucosylation by measuring postprandial blood glucose values the galactosaemic children showed significantly increased values for HbAIa-c (8.85 +/- 2.0% versus 7.7 +/- 0.3%; p less than 0.02), for GSP (0.43 +/- 0.13 mmol 5-HMF/mg protein versus 0.32 +/- 0.07 mmol 5-HMF/mg protein; p less than 0.005) as well as for urinary acid glycosaminoglycane excretion (45.3 +/- 23.4 micrograms/mg kreatinine versus 9.9 +/- 2.3 micrograms/mg Kreatinine; p less than 0.01). 3 out of the 6 children showed alpha 1-immunoelectrophoretic mobility of GBM antigens which was found also after incubation of GMB with galactose. The other 3 children had alpha 2-immobility, which was found in the healthy controls as well as in the control incubations. The impact of galactose on increased non-enzymatic glycosylation in children with galactosaemia as well as the significance of this finding for diagnostic purposes or for clarifying pathophysiological aspects of the disease remains to be studied further.

[L-carnitine therapy and myocardial function in children treated with chronic hemodialysis]. / L-Carnitintherapie und Myokardfunktion bei chronisch hämodialysierten Kindern.

Six out of 14 chronically hemodialysed children with significantly decreased serum carnitine levels were substituted with L-carnitine (15-30 mg/kg/day-Biocarn) up to normal and above normal carnitine levels. None of these patients were digitalised. During the time of investigation plasma carnitine levels were investigated monthly and, simultaneously, three echocardiographic parameters in M-mode were quantitatively und qualitatively determined: shortening fraction (SF-%), ratio of left ventricular pre-ejection/ejection time (LVPT/LVET) and velocity of circumferential fibre shortening (Vcf). Carnitine substitution produced measurable changes in echocardiographic parameters, and a significant quantitative improvement in left ventricular function and performance: after 6 months of carnitine substitution a 24% improvement was seen, after 18 months a 44% mean improvement. No side effects of carnitine were observed; the compatibility was good. Beside these positive effects all patients reported decreased dialysis-associated spasms and polyneuropathic symptoms and increased somatic ability.

[Urinary excretion of acid glycosaminoglycans and glomerular basement membrane antigens in patients with Alport's Syndrome (author's transl)]. / Harnausscheidung von sauren Glykosaminoglykanen und Glomerulumbasalmembranantigenen bei Patienten mit Alport Syndrom. Ein differentialdiagnostischer Beitrag.

Urinary excretion of acid glycosaminoglycans (AGAG) was estimated in 12 patients with Alport's syndrome (AS), 10 patients with idiopathic nephrotic syndrome and 10 healthy children. Comparing children with AS and healthy subjects or patients with idiopathic nephrotic syndrome, significant differences could be detected. Glomerular basement membrane antigen excreted into urine showed in 12 out of 12 patients with AS altered immunoelectrophoretic mobility into the beta-zone thus correlating with increased AGAG excretion. 10 patients with idiopathic nephrotic syndrome and 10 healthy children, showing normal AGAG excretion rates, presented normal glomerular basement membrane antigen with alpha-2-mobility.

[Excretion of acid mucopolysaccharides in the urine and sweat in hereditary bullous epidermolysis]. / Ausscheidung saurer Mucopolysaccharide in Harn und Schweiss bei Epidermolysis bullosa hereditaria.

Urine samples of five patients with epidermolysis bullosa hereditaria were examined for the presence of acid glycosaminoglycans (GAG) and compared to 10 healthy subjects. A significant increase (p less than 0.0005) could be detected in patients with epidermolysis (t = 6.66, means: 49.7 mg/day, standard deviation: +/- 18.3). Additionally, acid glycosaminoglycan concentration in sweat of patients and healthy controls was determined but statistical calculations showed no significant difference (p less than 0.15). On grounds of the increased mucopolysaccharide excretion and the previous studies of collagen-glycosaminoglycan interactions, we strongly suggest that acid GAG are involved in the pathogenesis of that disease with the molecular defect of disturbed fibril formation due to the altered skin collagen-glycosaminoglycan equilibrium.

L-carnitine substitution in patients on chronic hemodialysis.

Patients on chronic hemodialysis with hyperlipidemia were found to respond either with decreased levels (responders) or with a further increase of the plasma triglyceride levels (nonresponders) to a carnitine substitution therapy. The aim of the present study was to find possible predictors to distinguish between responders and nonresponders prior to the initiation of therapy. Since it is suggested that erythrocytes are involved in carnitine transport to tissues, it was of interest to determine plasma and erythrocyte carnitine concentrations in the hemodialyzed patients before and during carnitine substitution therapy and to compare the results with those of healthy controls. Before therapy, comparatively lower plasma levels of both free and total carnitine, but higher portions of short-chain acylcarnitine on total carnitine were found in all patients. In erythrocytes, the nonresponders showed significantly higher total carnitine levels, compared to responders and controls. After the start of carnitine substitution, the increase of total plasma carnitine during the substitution period corresponded with the carnitine dose administered in responders, in nonresponders the highest carnitine values were found in the second week when the lower carnitine dose was administered. The changes of the plasma short-chain acylcarnitine levels with time were very similar to those of plasma triglycerides. All patients showed a time-delayed accumulation of carnitine in erythrocytes and, interestingly, markedly higher concentrations in the second week when the lower carnitine dose was administered. The results of the present study demonstrate that the erythrocyte carnitine content is a reliable predictor to distinguish between responders and nonresponders prior to the start of a carnitine substitution therapy.

Neopterin as tumour marker serum and urinary neopterin concentrations in malignant diseases.

Serum and urinary neopterin concentrations were measured in 142 patients suffering from various malignant diseases. Increased serum and urinary neopterin levels were found in 48% and 55% of patients respectively. Neopterin showed sufficient sensitivity in the detection of haematological disorders and hypernephroma, whereas the sensitivity of neopterin was rather poor in patients with other solid tumours. Comparison of serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) concentrations and serum or urinary neopterin levels in testicular cancer patients showed that determination of neopterin provides no further information in the management of these patients. In testicular cancer patients receiving adjuvant chemotherapy, a significant increase in serum (p less than 0.005) and urinary (p less than 0.0005) neopterin concentrations was measured after chemotherapy, reflecting the release of neopterin from macrophages during the damage by cytotoxic drugs. In the adjuvant testicular tumour patients, known to be tumour free, 1 out of 16 patients showed elevated serum and 3 out of 15 patients showed false positive urinary neopterin levels. False positive serum (24%) and urinary (37%) neopterin values were also obtained in 28 patients with various nonmalignant diseases, but no evidence for an inflammatory process. In 23 patients with inflammatory diseases pathological serum and urinary neopterin levels were measured in 55% and 59% respectively. When a RIA was compared with a HPLC method, higher urinary neopterin values were obtained with the RIA, indicating that non-oxidized pterines are also determined by the RIA method. In conclusion, neopterin might be a helpful biological marker in monitoring patients with malignant haematological disorders and renal cell carcinoma, but provides no additional information in other solid tumours studied.

[Experiences with L-carnitine in the post-stress phase]. / Erfahrungen mit L-Carnitin in der Postaggressionsphase.

A prospective randomized double blind investigation was made in 24 multiple injured patients. All patients were treated with a combined parenteral-enteral nutrition during 7 days. A group of 11 patients received as a continuous infusion over 16 h 60 mg/kg BW carnitine daily. Beside carnitine and acetylcarnitine levels in plasma and urine the following parameters were determinated to evaluate the effect of carnitine: for the metabolism of fatty acids: triglycerides, free fatty acids (FFA), alpha-hydroxy-butyrate for the metabolism of carbohydrates: glucose, insulin and lactate in plasma. Finally for amino acid metabolism: urea, creatinine, cholinesterase and kolloid osmotic pressure in plasma as well as ureanitrogen and alpha-aminonitrogen excretion in urine. In the patients receiving carnitine especially acetyl-carnitine in plasma and acetyl-carnitine excretion in urine increased, proving that the administered carnitine can pass through the mitochondrial membrane. In these patients the plasma level of FFA was markedly lower than in the group without carnitine. Simultaneously the level of the alpha-hydroxybutyrate was elevated, equivalent to an increased oxydation of fatty acids. There was no difference between the two groups in the metabolism of carbohydrates. Administration of carnitine caused a slight increase of the production of urea (PU), catabolism could not be reduced. The excretion of alpha-aminonitrogen in urine augmented after carnitine infusion. Carnitine is an AA itself and so the amount of excreted alpha-amino nitrogen will increase; additionally the reabsorption of AA in the proximal renal tubulus may be inhibited by carnitine.

[Carnitine levels in pregnancy]. / Carnitinspiegel während der Schwangerschaft.

Carnitine (trimethylamino-hydroxy butyric acid) is present in all living cells. It is necessary for the transport of fatty acids into mitochondria and for other metabolic functions of the cell. Studies in various animal species have demonstrated a transfer of carnitine from the mother to the fetus during pregnancy. Recent studies reported decreased carnitine levels at term, but little is known on carnitine levels during various stages of human gestation. Therefore it was interesting to measure the blood carnitine status during normal human pregnancy from early stages up to term, including analyses of umbilical cord blood of the newborn. The results show a gradually decreasing carnitine level in maternal plasma, a sharp decline within the 1st trimester was followed by a much slower but highly significant decrease in the 2nd and 3rd trimester. In whole blood carnitine levels are decreasing, too. The continuous decrease of the portion of plasma carnitine in whole blood is correlated with a higher carnitine concentration in the blood cells. Together these results might indicate an increased need of carnitine during pregnancy. Therefore the clinical application of carnitine not only to provide a respiratory distress syndrome should be examined.

[Decreased plasma carnitine in Type I diabetes mellitus]. / Vermindertes Plasmacarnitin bei Typ-I Diabetes mellitus.

Realizing the importance of carnitine for the lipid and carbohydrate metabolism and the possible role for glucose utilization and myocardial function carnitine concentrations in type I and type II diabetic patients in plasma, erythrocytes and 24 h urine were determined. The plasma levels of carnitine were significantly diminished in type I diabetic patients compared to controls, while carnitine concentrations in erythrocytes and 24 h urine did not differ from controls. Plasma carnitine levels did not change significantly during the diurnial profile. No correlation between HbA1c and carnitine levels was observed in the diabetic patients.

[Angiotensin converting enzyme (ACE) a bloodtest for diagnosis of sarcoidosis (author's transl)]. / Angiotensin Converting Enzyme (ACE) Ein in vitro-Test für die Sarkoidose-Diagnostik.

Serum angiotensin-converting enzyme (ACE) was studied in 50 patients with sarcoidosis (39 active, 11 inactive) as well as in 50 control patients (34 with chronic nonspecific lung disease, 9 with Hodgkin and 7 with rheumatoid arthritis). There was a significant difference of ACE activity between sarcoidosis patients (28.6 +/- 11.4) and controls (14.8 +/- 4), and also between active (32.8 +/- 11) and the inactive (21.9 +/- 5.1) sarcoidosis (p less than 0.001). Coricosteroid treatment seems to lower ACE activity in patients with sarcoidosis without offering a clue for clinical improvement. Increased ACE activity in other granulomatous disorders is being discussed. ACE activity thus proves to be a valuable test especially in differentiating active from inactive sarcoidosis.

[Angiotensin converting enzyem (ACE) - a blood chemistry parameter in the diagnosis of sarcoidosis]. / Angiotensin converting enzyme (ACE)--ein blutchemischer Parameter in der Diagnostik der Sarkoidose.

Serum angiotensin converting enzyme (ACE) activity was studied in 50 patients with sarcoidosis (39 active, 11 inactive sarcoidosis), as well as in 50 control patients (34 chronic lung diseases, 9 Hodgkin-disease, 7 rheumatoid arthritis). There is a significant difference (p less than 0.001) of ACE-activity between sarcoidosis patients and controls, and between active (without steroid treatment) and inactive sarcoidosis. Steroid treatment apparently lowers ACE-activity in sarcoidosis, however, without evidence for clinical improvement. Increased ACE-activity was also found in a patient with primary biliary cirrhosis.

Evaluation of radioimmunoassays: comparison of dose interpolation calculations by four parameter logistic and spline functions.

Two computerized methods for dose interpolation calculation were compared. Generated data sets with a known coefficient of variation as well as laboratory RIA data were analysed. The four parameter logistic method, which is based on an approximation of the mass action law, performed better than the Spline method, a procedure which makes no a priori assumptions about the data. Correct weighting of the data was important for obtaining satisfactory fits. The determination of the response error relationship proved to be the most satisfactory approach in obtaining suitable weighting factors.

"Ocean-to-Ocean Project": a transcontinental external quality assessment trial in clinical chemistry realized throughout Eurasia.

More than 800 diagnostic laboratories situated throughout the Eur-Asian continent--from the Pacific Coast up to the North Sea littoral--were involved in a common survey of External Quality Assessment (EQA). It consisted of the simultaneous measurement of up to 30 analytes of 'general' clinical chemistry using the same batch of control material. The laboratories were associated in four EQA institutions: SKZL (The Netherlands), OQUASTA (Austria), SEKK (Czech Republic) and BKKSystem (Community of Independent States). The results demonstrated the feasibility of such a large-scale survey and provided a realistic idea about the state-of-the-art of laboratory diagnosis in these countries: Besides some local specific problems, such as poor quality of water or the forced use of reagents and calibrators from different sources, there are general problems hindering an efficient process of 'harmonization' in laboratory medicine, namely, the high methodological dispersion especially in the case of enzymes and of some organic analytes. At the same time there is a potential necessity for more concentrated implementation of internal quality assessment into the routine work of laboratories.