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Biomedical subjects

C Bachmann

Publications and source records attributed to C Bachmann.

At least 109 records · Page 6Linked to original sources
PubMed1987

Diagnosis of urea cycle disorders.

Hyperammonemia in pediatrics can be due to a number of causes (defects of urea cycle enzymes or transport of its metabolites, organic acidurias, acyl-CoA dehydrogenase or carnitine deficiency, liver bypass or nonspecific insufficiency) requiring differentiated rapid treatment for a satisfactory prognosis. The specific diagnosis cannot be established by clinical means. Thus the work-up rests on biochemical analyses. The methods used are detailed and their interpretation discussed. An algorithm for the interpretation of the data which can easily be computerized is presented. The procedure has proven practicable in 126 patients with urea cycle disorders.

Algorithms↗
PubMed1987

[Postnatal growth of the exterior nose].

The anthropological measurements about the nasal growth and the growth of different parts of the face have been done at 201 children between 3 and 14 a and 119 students of the Würzburg University. The jugal distance, the morphological face height, the nasal height, and the nasal depth, the nasal length, the intercanthal distance, and the alar distance were estimated. Included are measurements of the sagittal orbital angle, different indices of the face and nose.

Adolescent↗
PubMed1986

Stimulation of tryptophan uptake into brain microvessels by D-glutamine.

The uptake of L-tryptophan into isolated porcine microvessels is increased by preincubation with L-glutamine as well as with D-glutamine. This could indicate that gamma-glutamyltranspeptidase is involved in the stimulation of uptake of large neutral amino acids into the brain observed in hyperammonemic conditions.

Ammonia↗
PubMed1986

Biotin and Rett syndrome.

A protein load with an ensuing 20 hr fast was performed to assess the function of biotin dependent carboxylases in 3 girls with Rett syndrome. In plasma a moderate increase of ammonia and propionate was found. The fact that these discrete biochemical alterations were found in all of the patients supports earlier conclusions that further studies on biotin metabolism and carboxylase function should be performed, perhaps preferably in cerebrospinal fluid.

Amino Acids↗
PubMed1986

Rett syndrome revisited: a patient with biotin dependency.

A patient with Rett syndrome (cerebral atrophy associated with hyperammonemia) was studied. Primary defects of urea cycle enzymes were excluded as causes of the disorder. The analysis of urinary organic acids showed a moderate increase of lactate, methylcitrate, tiglyglycine and 3-hydroxisovalerate, indicating an abnormality of multiple carboxylases. Biotin supplementation reversed the urinary abnormalities. In fibroblasts grown with a low biotin medium propionylCoA and 3-methylcrotonylCoA carboxylase activities were reduced. Holocarboxylase synthetase activity was normal (Vmax and Km). Surprisingly the biotinidase in fibroblasts was not decreased. The data indicate that some patients with Rett syndrome might suffer from a biotin-dependent defect of unknown nature.

Amino Acids↗
PubMed1986

Brain uptake of tryptophan in urease-injected hyperammonemic rats after treatment with benzoate or hippurate.

The tryptophan uptake into forebrain and brainstem was measured in urease-injected rats and in controls after prior application of sodium benzoate or hippurate. Benzoate led to an increased brain uptake index of tryptophan. This effect was additive to the increase in tryptophan uptake effected by the provoked hyperammonemia. In contrast, hippurate did not alter tryptophan uptake across the blood-brain barrier. We conclude that benzoate should be monitored especially when applied intravenously to patients with hyperammonemic coma.

Animals↗
PubMed1986

[Cranial computed tomography in maple syrup urine disease].

Cranial computed tomography in the initial stage of the intermediate phenotype of maple syrup urine disease (MSUD) demonstrates diffuse, symmetric hypodensities in white and grey matter, which show a complete return to normal after early introduction of an adequate protein-restrictive diet. If diagnosis of this disease is missed or delayed, progressive global (end-stage) atrophy will take place over several years. A decrease in density values correlates well with the total cerebral lipid and water content (closely related to myelinisation), whereas progression and grade of atrophy show a relationship with the severity of pathological white and grey matter changes that are not demonstrable with computed tomography but can be proven histologically. Analysis of both morphological parameters corresponds well with clinical-neurological outcome and therapeutic success.

Brain↗
PubMed1986

Plasma levels and cardiovascular, endocrine, and excretory effects of atrial natriuretic peptide during different sodium intakes in man.

Endogenous plasma concentrations of human atrial natriuretic peptide (alpha hANP) as well as effects of synthetic alpha hANP on some cardiovascular, endocrine, and renal excretory parameters were investigated in 10 normal subjects during sodium (Na+) intakes of 17, 140, and 310 mmol/day, respectively. Plasma hANP was slightly but not significantly higher after 5 days of normal or high sodium intake than after 5 days of low sodium intake [54 +/- 13, 46 +/- 8, and 37 +/- 5 (mean +/- SEM) pg/ml, respectively]. alpha hANP infused at 0.1 microgram/kg X min during all Na+ intakes produced a similar fall in diastolic blood pressure (P less than 0.001) and rise in heart rate (P less than 0.001), a comparable percent increase in plasma norepinephrine (P less than 0.001), and a reduction in plasma cortisol and aldosterone (P less than 0.01-0.001) despite raised renin activity (P less than 0.05-0.001) and unchanged plasma electrolytes. alpha hANP-induced plasma volume contraction, diuresis, and natriuresis were greater during high than low Na+ intake (P less than 0.01-0.001). Therefore, in normal man different Na+ intakes are accompanied by marked modifications in renal excretory responsiveness to alpha hANP. Regardless of sodium intake, alpha hANP can promote BP reduction and hemoconcentration, elicit reflex (?) sympathetic activation, and depress basal circulating aldosterone and cortisol levels in the face of an activated renin system.

Adult↗
PubMed1986

Cardiovascular, endocrine and renal effects of atrial natriuretic peptide in essential hypertension.

Plasma concentrations of human atrial natriuretic peptide (hANP) and effects of synthetic alpha-hANP on blood pressure (BP), on endocrine and metabolic variables, and on renal function were investigated in 10 patients with essential hypertension. Alpha-human atrial natriuretic peptide was given intravenously as a 50-micrograms bolus followed by a 45-min infusion at 0.1 microgram/kg per min. The following effects were observed: (1) a marked rise in plasma alpha-hANP, (2) a progressive fall in BP (from 181/127 to 165/109 mmHg) and plasma volume, (3) a probably baroreflex-mediated sympathetic activation, evidenced by raised heart rate and plasma norepinephrine levels, (4) an increase in serum free fatty acids and circulating insulin (+45%), (5) an enhanced diuresis (+770%) and excretion of sodium (+665%), chloride (+524%), phosphate (+518%), other electrolytes, amino acids and free water clearance, (6) biphasic responses in the glomerular filtration rate (GFR) and p-aminohippurate (PAH) clearance, with initial increases (+40 and 30%, respectively) followed by a rapid return to (GFR), or even a fall below (PAH clearance) control values, and (7) a marked rise in the filtration fraction. Plasma antidiuretic hormone and urinary prostaglandin E2, F2 alpha and dopamine levels were not modified during alpha-hANP infusion, while plasma renin increased. Discontinuation of alpha-hANP was followed by rises in plasma aldosterone, the aldosterone:renin ratio and cortisol. Compared with previously studied normal subjects, in the hypertensive patients alpha-hANP caused a distinctly greater diuresis and electrolyte excretion but lowered BP only slightly more. In essential hypertension, as in normal man, alpha-hANP circulates in the blood and may exert a wide spectrum of cardiovascular, metabolic, endocrine and renal actions.

Adult↗
PubMed1986

Severe liver fibrosis in argininosuccinic aciduria.

Hepatomegaly is an important clinical finding in patients with argininosuccinic aciduria (a hereditary defect of the urea cycle enzyme, argininosuccinate lyase [argininosuccinase]). A severe degree of liver fibrosis, almost corresponding to cirrhosis, was observed in liver biopsy material obtained from a boy with this disorder. This observation is of interest in light of the fact that liver fibrosis or cirrhosis are hallmarks of many inheritable phenotypes, and especially of inborn errors of metabolism. Variable degrees of liver fibrosis are noted in other inborn defects of the urea cycle, eg, in ornithine transcarbamylase and carbamoylphosphate synthetase deficiencies. These findings appear to indicate that inheritable defects of urea synthesis may form a group of metabolic disorders prone to cause hepatic fibrosis, or even cirrhosis, as shown in our patient.

Amino Acid Metabolism, Inborn Errors↗
PubMed1985

[Effective long-term treatment of primary hyperlipoproteinemias with bezafibrate].

Bezafibrate, a new hypolipidemic agent, was evaluated in a single blind, placebo-controlled study lasting 14 months to 3 years in 40 patients with primary hyperlipoproteinemia of various types (23 patients with type II, 15 with type IV and 2 with type V). Bezafibrate in a dose of 200 mg 3 times daily reduced total serum cholesterol by an average of 17% (p less than 0.001) in hyperlipoproteinemia type II and by 24% (p less than 0.001) in type IV or V, lowered serum triglycerides by 31% (p less than 0.001) in hyperlipoproteinemia type II and by 58% (p less than 0.001) in type IV or V, while high-density-lipoprotein-cholesterol was increased by 17% (p less than 0.001) in type II and by 36% (p less than 0.001) in type IV or V. The few side effects encountered were only mild and transient. These findings show that bezafibrate affords safe and effective long-term treatment of patients with hyperlipoproteinemia.

Adult↗
PubMed1985

Fructose-1,6-diphosphatase deficiency: glycerol excretion during fasting test.

A Turkish boy had suffered since the age of 10 months from recurrent attacks of severe metabolic acidosis and hypoglycaemia precipitated by moderate respiratory tract infections. A liver biopsy showed lack of fructose 1,6-diphosphatase and absence of phosphorylase. The patient died in shock following fructose ingestion. Upon fasting, acidosis with increased lactate and glycerol excretion was found. Findings indicate that, in this inherited disorder of gluconeogenesis, lactic acidosis combined with increased glycerol excretion upon fasting are of diagnostic importance.

Acidosis↗
PubMed1985

Effects of the dopaminergic agonist cianergoline on blood pressure, the renin-angiotensin-aldosterone axis and the sympathetic nervous system in patients with essential hypertension.

Cianergoline is a new dopaminergic agonist with a predominant cardiovascular action. Its effects on blood pressure, the renin-angiotensin-aldosterone axis, the sympathetic nervous system and lipid metabolism were assessed in 20 patients with benign essential hypertension. Cianergoline given in increasing doses for 4 weeks (maximum daily dose 12 +/- 2 mg (SD)) and placebo both caused a slight decrease in arterial pressure, (from 159/104 to 152/98 mm Hg and from 154/104 to 149/103 mm, respectively; difference not significant). Supine and upright plasma renin activity, plasma aldosterone, norepinephrine, epinephrine and dopamine levels, urinary catecholamine excretion rates as well as serum prolactin, low and high density cholesterol and triglyceride concentrations were not changed after cianergoline or placebo. Total serum cholesterol and triglyceride levels decreased significantly after placebo, but were unchanged after cianergoline. 3 out of 10 patients in the cianergoline group complained of nausea. The findings indicate that the new dopaminergic agonist cianergoline exerts only a mild blood pressure lowering effect in patients with essential hypertension and does not modify the release of prolactin, lipid metabolism or the basal activity or postural responsiveness of the renin-angiotensin-aldosterone axis and of the sympathetic nervous system.

Adult↗
PubMed1985

Liver pathology in a new congenital disorder of urea synthesis: N-acetylglutamate synthetase deficiency.

Detoxification through the urea cycle is the means by which mammalian organisms dispose of their excess ammonia. Within this cycle, N-acetylglutamate (NAG) is the most important cofactor for optimal enzyme activity. It is formed from acetyl CoA and glutamate through the action of N-acetylglutamate synthetase (NAGS). Recently, a congenital deficiency of NAGS has been reported. In this communication, we present results of structural investigations on liver tissue of the index patient with NAGS defect. Light microscopy revealed small, eosinophilic inclusions in some of the hepatocytes. Electron microscopy showed vesicular SER and fibrillar material in expanded cisterns of the RER, presumably corresponding to the inclusions seen in light microscopy. Immunofluorescence of liver tissue uncovered a discrete distribution of intracellular albumin in the form of small deposits. We suggest that in NAGS deficiency, some secretory proteins might be incompletely processed due to the lack of a protease activator, NAG.

Acetyltransferases↗
PubMed1985

Activities in the placenta and fetal membranes of enzymes involved in energy metabolism.

The placenta and the fetal membranes differ in their energy dependent functions and in their blood supply. In a search for quantitative differences in the expression of enzymes involved in energy metabolism in these tissues we measured in the placenta and in amnion and chorion the activities of enzymes involved in carbohydrate metabolism (hexokinase, phosphofructokinase, lactate dehydrogenase, glycogen phosphorylase), a tricarboxylic acid cycle enzyme (succinate dehydrogenase) and an enzyme involved in fatty acid oxidation (hydroxyacyl-CoA-dehydrogenase). The activities of succinate dehydrogenase and hydroxyacyl-CoA-dehydrogenase in the placenta were higher than those in the membranes, whereas the activities of the other enzymes assayed were lower. Lactate dehydrogenase activity was higher in the amnion than in the chorion (p less than 0.01). These results could indicate that the fetal membranes depend mainly on glycolysis for an energy supply.

3-Hydroxyacyl CoA Dehydrogenases↗