Phosphatidylcholine-fatty acid membranes. I. Effects of protonation, salt concentration, temperature and chain-length on the colloidal and phase properties of mixed vesicles, bilayers and nonlamellar structures.

The phase and colloidal properties of phosphatidylcholine/fatty acid (PC/FA) mixed vesicles have been investigated by optical methods, acid-base titration, and theoretically as a function of temperature (5-80 degrees C), molar lipid ratio (0-1), lipid chain length (C14-C18), headgroup ionization (1.5 less than or equal to pH less than or equal to 10), vesicle concentration (0.05-32 mumol vesicle.dm-3, and ionic strength (0.005 less than or equal to J less than or equal to 0.25). Increasing the fatty acid concentration in PC bilayers causes the phase transition temperatures (at 4 less than or equal to pH less than or equal to 5) to rise until, for more than 2 FA molecules per PC molecule, the sample turbidity exhibits only two transitions corresponding to the chain-melting of the 1:2 stoichiometric complexes of PC/FA, and pure fatty acid. The former transition is into a nonlamellar phase and is accompanied by extremely rapid vesicle aggregation (with association rates on the order of Ca approximately 10(7) dm3.mol-1.s-1) and massive lipid precipitation. Fluid-phase vesicles with less than 2 FA per PC associate much more slowly (Ca approximately 10(3) dm3.mol-1.s-1), their aggregation being comparable to that of the ordered-phase liposomes. Under no conditions was the relation between the fatty acid concentration and the vesicle association rate for the fluid-phase vesicles linear. In contrast to the X-ray diffraction data, optical measurements reveal a 'pretransitional region' between the chain-melting temperature of the PC component and the temperature at which the gross transformation into a nonlamellar phase sets in. This is seen for all lipid mixtures investigated. On the relative temperature scale, lipids with different chain lengths behave qualitatively similarly; however, the effective association constants determined for samples of constant lipid concentration seem to decrease somewhat with the number of CH2 groups per chain. Fatty acid protonation, which yields electrically neutral bilayers, invariably increases the rate of vesicle association; we have measured, for example, Ca approximately 10(2) at pH approximately 7 and Ca approximately 10(7) dm3.mol-1.s-1 at pH approximately 4). Protonation of the phosphatidylcholine phosphate groups, which causes a net positive charge to accumulate on the lipid vesicles, initially increases (Ca approximately 10(8) dm3.mol-1.s-1) but ultimately decreases (Ca approximately 10(7) dm3.mol-1.s-1) the rate of association between PC/FA (1:2) mixed vesicles.(ABSTRACT TRUNCATED AT 400 WORDS)

Increased levels of 4-hydroxynonenal modified proteins in plasma of children with autoimmune diseases.

Analysis of serum samples of healthy children (n = 11) and children with Systemic Lupus Erythematosus (SLE), (n = 21) was performed by SDS-PAGE and immunoblot with an antibody directed against proteins modified by lipid peroxidation (LPO) product 4-hydroxynonenal (HNE). A single major stained protein band was detected. By comparison of the molecular weights in nonreducing and reducing SDS-PAGE was found that the main protein modified by HNE is immunoglobulin G. Significantly higher concentrations of the aldehyde modified protein were found in children with high disease activity of SLE measured by SLE disease activity index (SLEDAI). Lipid peroxidation measured by malondialdehyde and 4-hydroxynonenal concentrations show an enhanced level of both compounds also in patients with the active autoimmune disease. Therefore, it can be assumed that free radical mediated processes play a pathophysiological role in the active phase of SLE and HNE-modified serum proteins are a further parameter for the detection of in vivo LPO.

Familial dysautonomia: a diagnostic dilemma. chronic lung disease with signs of an autoimmune disease.

We present an 11-year-old girl with sensory and autonomic neurological dysfunction, and respiratory insufficiency caused by recurrent aspiration. The diagnosis of familial dysautonomia (FD) was confirmed by a missing axonal flare to histamine, miosis in response to conjunctival methacholine and homozygous polymorphic linked markers DS58(18) and DS159(7) on chromosome 9. Ashkenazi Jewish descent could not be ascertained by history. A variety of positive tests for autoantibodies were initially interpreted as evidence for systemic lupus erythematosus vs. overlap syndrome with pulmonary, cerebral, skin, and ocular involvement. The diagnosis of FD was delayed because of the rarity of this disorder in Germany (second case reported). We discuss possible explanations for the misleading immunological findings, including interference by antibodies binding to milk proteins used as blocking reagents in enzyme-linked immunoassays and circulating immune-complexes due to chronic aspiration pneumonitis.

[Subvesical urinary track obstruction in children as the cause of chronic renal failure]. / Subvesikale Harnwegsobstruktion bei Kindern als Ursache für die chronische Niereninsuffizienz.

The infantile stenosis of the vesical cervix is a rare disease, etiology and pathogenesis of which are controversial. If it is not treated it leads to uraemia. On the basis of a clinical material consisting of 8 patients clinic and course of the disease are discussed. In the children with stenosis of the vesical cervix observed by us disturbances of the miction (bilateral mictions, thin urinary stream), relapsing abdominal pain, enuresis, minor growth and haematuria were in the first place. We got clearness on the diagnosis by judging the mode of miction, by means of miction cystourethrography and by urethrocystoscopy. Even in stenosis of the vesical cervix with advanced renal insufficiency also in childhood an operation should be performed.

[Uremic plasma as cause of metabolic changes in red blood cells]. / Das urämische Plasma als Ursache für Stoffwechselveränderungen roter Blutzellen.

Under the influence of the uraemic plasma a number of changes of the metabolism of red blood cells develop. By means of cross experiments with the help of filtrability, of sulf-haemoglobin formation and the 125-iodine-hippuran intake the influence of the uraemic plasma and of the plasma of healthy persons on the red blood cells of children who undergo a chronic haemodialysis as well as of healthy adults (cross experiments) was examined. The red blood cells of the control persons after an incubation at 37 degrees and 60 or 180 minutes showed approximately the same changes of filtrability, formation of sulf-haemoglobin and 125-iodine-hippuran as the red blood cells of the patients with incubation in the autologous plasma. Disturbances of the filtrability and the formation of sulf-haemoglobin could be proved in the uraemic red blood cells still after reincubation in the normal plasma, though clearly reduced. Only in 125-iodine-hippuran a normalisation could be got. Filtrability and formation of sulf-haemoglobin apparently comprise more complex processes which essentially influence the life span of the red blood cells, whereas the 125-iodine-hippuran value characterizes only a part of the metabolism of the red blood cells, the passive transport of anions.

Changes in glucose 6-phosphate dehydrogenase and phosphofructokinase activity during maturation and ageing of red blood cells in children with chronic renal insufficiency.

Red blood cells (RBC) of children with terminal renal insufficiency show a reduction of the apparent 51Cr RBC half-life (16.5 +/- 5.5 days). The enzymatic activities of phosphofructokinase (PFK) and glucose 6-phosphate dehydrogenase (G6PD) in the RBC of these patients do not differ from those in health persons. The RBC of uraemic and healthy children were separated by density gradient centrifugation in dextran medium according to maturity and age. RET count, mean cellular Hb concentration (MCHC), PFK and G6PD activities were determined in the separated cell populations. MCHC increases with increasing cell density while the number of RET decreases. There is a distinct decrease in the G6PD activity of low-density cells compared to high-density cells. The extent of the decrease in enzymatic activity is about the same for healthy persons as for uraemic patients. A more rapid decrease in G6PD activity per unit of time can be assumed when the enzymatic activity is plotted against the distinctly shortened life span of the RBC of the uraemic children. There is a possible relationship between G6PD activity in old RBC and the premature destruction of these cells. PFK activity apparently does not decrease with increasing cell age.

[The pathogen spectrum and its resistance behavior in children with urinary tract infections in Angola]. / Zum Erregerspektrum und seinem Resistenzverhalten bei Kindern mit Harnwegsinfektionen in Angola.

In 225 children (135 boys, 90 girls) suffering from clinical relevant urinary tract infection the bacterial spectrum and resistance behaviour to routinely used antibiotics were evaluated. In 65.4% of the patients a significant bacteriuria was found: E. coli (34.6%), proteus (22.3%), klebsiella (14.6%), citrobacter (9.2%), enterobacter (5.4%) and pseudomonas (5.4%). In testing a high resistance of bacterias to trimethoprim/sulfamethoxazol, ampicillin, and gentamycin was found, whereas good susceptibility was found to nitrofurantoin and nalidixin acid.

[The status of hemoglobin concentration and hematocrit in Angola children]. / Zum Verhalten von Hämoglobinkonzentration und Hämatokrit bei angolanischen Kindern.

Hemoglobin-concentration (Hb) and hematocrit (Ht) were determined in 622 Angolean children between ages of 3 months and 13 years. The children were divided into two groups: group I (n = 530) of low social and economic state, group II (n = 92) children enjoyed good living conditions. 38.9% of all children had a Hb below 6.8mmol/l. 218 of which were part of group I, only 18 were out of group II. An extensive anemia (less than Hb 4.3mmol/l) existed in only 3% of all children. 51.7% of children were below 3 years. Between age groups of 3 months to over 10 years there was a continual rise in Hb of 17.6 +/- 6.6% (boys) and 9.5 +/- 3% (girls). Using the Ht values the percentage of anemic children was only 16.4%. It existed a relationship, especially, clearly observed in group I, between physical development and aemia frequency. Children of group I were more anemic than children of group II.

Increased lipid peroxidation in children with autoimmune diseases.

To examine the role of oxidative damage in children and adolescents with autoimmune diseases, we compared blood serum levels of the lipid peroxidation (LPO) products 4-hydroxynonenal (HNE) and malondialdehyde (MDA) in 22 children with systemic lupus erythematosus (SLE), 13 children with focal type of scleroderma, and 21 health controls. In order to study the influence of disease activity in SLE on serum LPO product levels, the SLE group was divided into one group with active disease (n = 11) and one group with non-active disease (n = 11) according to SLEDAI-score, 15.1 and 1.8, respectively. SLE patients with active SLE (146 +/- 14 nmol/l, median 145 nmol/l) have significantly higher HNE levels compared to controls (61 +/- 10 nmol/l, median 52 nmol/l), whereas the MDA serum levels are similar to those of the control group, 1.94 +/- 0.18 mumol/l (median: 2.02 mumol/l) and 1.58 +/- 0.11 mumol/l (median: 1.52 mumol/l), respectively. Children with SCL had HNE and MDA levels similar to the control group.

[Behavior of creatine in red blood cells and in plasma of children with chronic kidney insufficiency]. / Das Verhalten des Kreatins in roten Blutzellen und im Plasma von Kindern mit chronischer Niereninsuffizienz.

The creatine concentration of red blood cells and plasma in 44 children with chronic renal failure was studied and found to be significantly higher than in healthy children of comparable age. The creatine concentrations of the 31 hemodialyzed children surpassed those of the 13 conservatively treated patients by 30%. A statistically significant correlation was demonstrated between the serum creatinine level and the creatine concentrations in red blood cells. During hemodialysis the plasma creatine concentration decreases by half and reaches the predialysis values within 42 h after the end of dialysis, whereas the creatine concentration of the red cells does not change during a 4-5-h hemodialysis. With increasing number of hemodialyses the creatine concentration of red cells rises, suggesting an improvement of erythropoiesis.

Phospholipid content and phospholipid fatty acid composition of red blood cells in enzyme defect hemolytic anemias.

The content and distribution of phospholipids (PL) in red blood cells (RBC) of PK and of G6PD deficiency were found to differ in both disorders. RBC immaturity could not be excluded as reason for PL alterations in PK deficiency. The relative diminution of phosphatidylethanolamine in G6PD deficiency may be connected with the enzyme depletion in this disorder and its influence on the PL of RBC membranes. Moist or all fatty acid deviations seem to be conditioned by RBC immaturity. Nearly all PL fatty acid aberrations in G6PD deficiency RBC were observed also in PK deficiency RBC. Additional deviations of PL fatty acids in PK deficiency RBC may be caused by the stronger immaturity of the cells in this disorder.

Erythrocyte and plasma lipids in terminal renal insufficiency.

Lipids in erythrocytes and plasma of children and adults with terminal renal insufficiency were determined and compared with those of normal controls. The erythrocyte phospholipids in uremic patients were altered in phosphatidylethanolamine (absolutely and relatively elevated) and in lecithin (relatively diminished). Sphingomyelin, phosphatidylserine, total erythrocyte phospholipid content and cholesterol were within the normal range. The detailed analysis of the distribution of plasma phospholipids showed an increase in all phospholipids except phosphatidylserine. The unesterified plasma cholesterol was also found to be elevated. The fatty acid distribution in the individual erythrocyte phospholipids showed the following variations in comparison with controls: one main fatty acid was significantly decreased in sphingomyelin and in lecithin and slightly decreased in phosphatidylethanolamine. It could be shown that the lipid alterations in uremic erythrocytes were quite different from those in plasma. There were not typical signs for an increased lipid peroxidation in the erythrocytes of patients with renal insufficiency.

Kinetic profiles of ochratoxin A and ochratoxin alpha during in vitro incubation in buffered forestomach and abomasal contents from cows.

Pure ochratoxin A (OA) was added to buffered rumen fluid collected from fistulated cows and incubated under anaerobic conditions. The kinetic pattern of the disappearance of OA and the appearance of ochratoxin alpha (Oalpha) was principally the same with four diets fed to donor animals and with three donor animals. The concentration of OA declined to a very low or non-detectable level with half-lives at 0.17-1.84 h; its rate of disappearance was first order throughout. The concentration of Oalpha increased to a constant level under all conditions examined. The average amounts of Oalpha formed relative to the disappearance of OA were not different (p > 0.05) and ranged between 94 +/- 8 and 98 +/- 8 %. The rate of disappearance of OA differed (p < 0.001) between diets and animals. It was accelerated by increasing the content of concentrate in the diet. Ochratoxin alpha was not metabolized when added in pure form to buffered rumen fluid and incubated under the same conditions as OA. Pure OA was also added to buffered fluids from the forestomach and abomasum of a slaughtered cow. It disappeared exponentially in a mixture of fluids from the rumen and reticulum and in fluid from the omasum, with the average amounts of Oalpha formed relative to OA disappearance being 107 and 109 %, respectively. Ochratoxin A also was not metabolized in fluid from the abomasum. These studies demonstrate that OA is hydrolysed in the rumen via first order kinetics, diet and animal affect the rate of hydrolysis, OA is quantitatively converted to Oalpha and Oalpha is not degraded.

[Glomerulonephritis (GN) in childhood. I. Epidemiology, clinical aspects and kidney function in 125 children]. / Zur Glomerulonephritis (GN) im Kindesalter. I. Mitteilung: Epidemiologie, Klinik und Nierenfunktion von 125 Kindern.

The blood pressure, urinary symptoms (proteinuria, hematuria, casts), the albumin- and cholesterol concentration in the serum and the renal function (GFR, RPF) of 125 children with chronic glomerulonephritis (GN) were analysed. 76 children had only single symptoms (93% proteinuria, 33% hypertension), which indicated a GN. The serum albumin and cholesterol concentration were pathological in 43% of the patients and serum creatinine level was pathological in 20% of the children. After 6 years the individual courses of renal function demonstrated a deterioration of GFR and RPF for most of the children. It can be concluded, that the summary consideration of epidemiology, symptomatology and renal function of different glomerular lesions has only a limited application to the clinical practice.

[Glomerulonephritis (GN) in childhood. II. Epidemiology and clinical aspects of various histological forms of glomerulonephritis]. / Zur Glomerulonephritis (GN) im Kindesalter. II. Mitteilung: Epidemiologie und Klinik verschiedener histologischer Glomerulonephritisformen.

From 101 children with histological verified glomerulonephritis the following data were analyzed according to the morphological alterations: age distribution, symptoms and onset of the disease, previous diseases, and observation time. Differences of these parameters were found firstly between minimal glomerular changes and proliferative lesions. Within the various proliferative forms the differences were minimal. In children with a diffuse mesangio-proliferative glomerulonephritis and MPGN the characteristics of blood pressure, proteinuria and hematuria were observed during a follow-up time of 5 years. In conclusion, a distinction between single types of glomerulonephritis could be made exceptionally without examination of kidney function and morphology.

[The incidence of kidney diseases in a pediatric kidney dispensary]. / Zur Häufigkeit von Nierenerkrankungen in einem pädiatrischen Nierendispensaire.

400 children (141 boys and 259 girls) in a renal disease care system were analyzed regarding their most frequent diagnoses of renal diseases and their age and sex distribution. Furthermore, the familiary situation, the time of observation, the number of consultations and the frequency of morphological changes of the kidney and the urinary tract were examined. 72% of the children suffered from urinary tract infection and in 10% a glomerulopathy and in 5.5% an urolithiasis were found. The symptoms of enuresis occurred in 22.2% of the patients. Infants were the most frequent age group (18%), 70% of which were boys. We found no differences in the incidence of renal diseases in comparison with other reports.

[Oral galactose loading in characterizing the elimination and metabolizing performance of the liver in chronic renal failure]. / Die orale Galaktosebelastung zur Charakterisierung der Eliminations- und Metabolisierungsleistung der Leber bei chronischer Niereninsuffizienz.

For characterising the elimination and metabolisation performance of the liver in chronic renal insufficiency the galactose load test was carried out. 9 children with healthy liver and kidneys, 35 children with chronic renal insufficiency (15 were conservatively treated = group 1, 20 were in the chronic haemodialysis programme = group 2) as well as 5 children after kidney transplantation were examined. In group 1 a normal blood galactose concentration was present. Patients of the 2nd group showed increased concentrations of galactose in the blood which might refer to a decreased redox potential in the liver caused by the uraemic intoxication. In the group of patients who underwent a kidney transplantation in the patients with azathioprine therapy a disturbed use of galactose was present. Children with cyclosporin-A had a normal galactose concentration.

[Sickle cell disease in the People's Republic of Angola. 1. Epidemiology and clinical aspects]. / Zur Sichelzellerkrankung (S. E.) in der Volksrepublik Angola. 1. Mitteilung: Epidemiologie und klinische Aspekte.

In a period of 6 years 819 children affected with drepanocytosis (S. E.) were treated at the children's clinic in Luanda. At the time of diagnosis the age of the 457 boys amounted to 3.4 +/- 2.7 years and that of girls to 4.3 +/- 3.4 years. The age distribution shows that 40.2% of the patients were in their first 2 years of life. Conditions of crisis which affected 70% of the diseased children are typical of this disease. The family anemnesis demonstrated that 13.6% of all brothers and sisters covered were HbSS positive. 34.1% of them died at an age of 3.5 +/- 3.5 years (boys) or 2.4 +/- 2.3 years (girls) respectively. The physical development measured in the body mass shows that it is significantly diminished in comparison with healthy children of the same age. The characteristic symptom of this disease, splenomegaly, existed in 27.8% of the children with a mean age of 2.8 +/- 2.3 years. In one age group of 4.4 +/- 2.6 years it could even be identified in 11.3% of the cases.