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Biomedical subjects

C Bachmann

Publications and source records attributed to C Bachmann.

At least 127 records · Page 7Linked to original sources
PubMed1985

Galactose and galactitol in the urine of children with compound heterozygosity for Duarte variant and classical galactosemia (GtD/gt) after an oral galactose load.

An oral dose of galactose, 1 g/kg of body weight, was administered to 24 children with the Duarte variant/classical galactosemia genetic compound (GtD/gt) and to 16 controls ranging in age from 0.3 to 10.7 years. Urine was then collected for 3h. Excreted amounts of galactose and galactitol increased with age in all subjects, but were consistently greater in the compound heterozygotes. If related to urinary creatinine, galactosuria and galactitoluria were no longer age-dependent, although as compared with the controls, urinary galactose was about three times and urine galactitol twice as high in the patients (p less than 0.01 for both). We found a statistically significant correlation between urinary galactitol and galactose in these patients. Moreover, urinary galactitol and galactose each correlated positively with the area under the plasma galactose curve, as well as with the peak value for plasma galactose after galactose ingestion.

Aging↗
PubMed1984

Treatment of congenital hyperammonemias.

A rapid recognition of congenital hyperammonemia, a clear diagnostic workup and institution of a combined treatment without delay, by restriction of nitrogen supply, adequate caloric supply, substitution of missing metabolites, and use of alternate routes of nitrogen excretion will help to control hyperammonemic crises and improve the prognosis. For long-term treatment the use of essential amino acid mixtures and perhaps of antiserotoninergic agents is needed.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

Increase of tryptophan and 5-hydroxyindole acetic acid in the brain of ornithine carbamoyltransferase deficient sparse-fur mice.

Sparse-fur mice, 28 d of age with the x-chromosomal inherited defect of ornithine carbamoyltransferase, were used to investigate if tryptophan and the serotonin pathway in the brain are affected in this animal model which closely resembles the human inborn error of metabolism. Increased concentrations of tryptophan and 5-hydroxyindole acetic acid were found in forebrain and brainstem. Application of probenecid, which blocks the efflux of 5-hydroxyindole acetic acid from the brain, led to an augmented accumulation of this serotonin metabolite in the affected males. We conclude that the increased concentration of tryptophan in brain and the subsequent increased flux through the serotonin pathway are a consequence of hyperammonemia in this inherited defect of urea synthesis. Surprisingly, increased carbamoylphosphate synthetase was found in the liver of the male sparse-fur mice.

Animals↗
PubMed1983

Increased tryptophan uptake into the brain in hyperammonemia.

Hyperammonemia was provoked in rats by urease injection over three days. Tryptophan transport into the forebrain measured by the bolus injection technique was increased in hyperammonemic rats in comparison with pairfed controls. The concentration of the large neutral aminoacids, of tryptophan and of 5-hydroxyindole acetic acid were increased in the forebrain and brainstem. Probenecid administration led to a significantly higher accumulation of 5-hydroxyindole acetic acid in the forebrain of hyperammonemic rats. Since liver function was not impaired the data indicate that hyperammonemia in absence of hepatic insufficiency alters the carrier function for large neutral aminoacids at the blood brain barrier.

Amino Acids↗
PubMed1983

Liver pathology in transient neonatal hyperammonemia.

Ultrastructural investigations have been performed on two cases of transient neonatal hyperammonaemia (TNH). This newly recognized metabolic disorder is chiefly characterized by severe hyperammonaemia in the postnatal period, a comatous state, absence of abnormal organic aciduria, normal activity of urea cycle enzymes and, usually, complete recovery. The aetiology is presently unknown. Electron microscopy uncovered rather congruent alterations of hepatocyte structure, with a wide spectrum of mitochondrial lesions, an increase of autophagous bodies with organelle remnants, and changes in the excretory apparatus. Thus, in contrast to some of the hereditary disorders of the urea cycle, no specific structural changes could be found in TNH. This finding is in line with the observation of normal activities of main urea enzymes in these cases, and indicates that a different biochemical system may be pathogenetically involved in TNH.

Ammonia↗
PubMed1983

[Not Available].

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History of Pharmacy↗
PubMed1983

[Pulmonary hemorrhages in newborn infants with inborn errors of the 1st 2 phases of the urea cycle].

Two critically ill, male newborns developed pulmonary bleeding and died after four respectively three days. In both infants an inborn error in the urea cycle (carbamylphosphatsynthetase-deficiency and ornithintranscarbamylase-deficiency respectively) was demonstrable. It is suggested that hyperammonemia could be the reason for pulmonary bleeding. Plasma ammonia levels should be determined in newborns with pulmonary bleeding, especially in those with normal weight and good health at birth.

Amino Acid Metabolism, Inborn Errors↗
PubMed1982

Serum lipoproteins in patients with mild renal disease treated with the diuretic muzolimine.

Patients with renal functional impairment are prone to develop hypertension and hyperlipidemia, and both abnormalities tend to occur already at an early stage of kidney disease. In 18 patients with mild renal disease (glomerular filtration rate 65 +/- 5 ml/min) and hypertension (mean blood pressure 126 +/- 4 mm Hg), the effect of six weeks of treatment with the loop-diuretic muzolimine on serum lipoproteins was assessed. Compared to placebo values, the diuretic significantly increased serum low-density lipoprotein cholesterol (LDL-C) and apoprotein B (+ 18 and 11%, respectively, P less than 0.005) in 13 men or postmenopausal women, but not in 5 premenopausal women. Serum high-density lipoprotein cholesterol (HDL-C), and total triglycerides or lipoprotein triglyceride fractions were not consistently changed in both subgroups. Thus, the ratio LDL-C/HDL-C was increased from 3.2 +/- 0.3 to 3.9 +/- 0.3 (P less than 0.05) in the men or postmenopausal women, while no such tendency occurred in the premenopausal women (4.1 +/- 0.6 to 3.7 +/- 0.6). Changes in serum LDL-C were not associated with hemoconcentration or alterations in carbohydrate metabolism and were not related to variations in serum potassium or blood pressure. Increased serum levels of the atherogenic LDL-C fraction during diuretic treatment in men or postmenopausal women with renal disease may represent a potentially undesirable effect, particularly since such patients may tend to have hyperlipidemia in the untreated state.

Female↗
PubMed1982

Purification and properties of acetyl-CoA:L-glutamate N-acetyltransferase from human liver.

Acetyl-CoA:L-glutamate N-acetyltransferase (amino acid acetyltransferase, EC 2.3.1.1) was isolated from human liver mitochondria by precipitation with (NH4)2SO4 and chromatography on hydroxyapatite, DEAE-cellulose and Sephacryl 300. This gave a 360-fold purification. The molecular weight was estimated to be approx. 190 000. The kinetic properties in the absence of arginine are compatible with a rapid-equilibrium random Bi Bi mechanism. The estimated constants are: for the substrates Km,acetyl-CoA 4.4 mM, Ki,acetyl-CoA 4.7 mM, Km,glutamate 8.1 mM, Ki,glutamate 8.8 mM; for the products, Ki,acetylglutamate 0.28 mM, Ki,CoA 5.6 mM. The rate constant for the forward direction is 1.24s-1. If in vivo the constants are of the same order of magnitude as in vitro, the synthesis of N-acetylglutamate, an obligate activator of the first step of urea synthesis, can be expected to occur in the mitochondrion under conditions where the amino acid acetyltransferase is not saturated by its substrates. The regulation of the first step of urea synthesis could thus depend mainly on the intramitochondrial substrate and perhaps product concentrations of amino acid acetyltransferase.

Acetyl Coenzyme A↗
PubMed1982

Incidence of disorders tested by systematic screening: confidence limits and comparison of programmes.

Using the data from screening done in Switzerland since 1965, we showed that the probability of finding cases with increased phenylalanine or leucine concentrations is compatible with a Poisson distribution. If there are no trends present from year to year and if the Poisson distribution is an accurate fit further statistical treatment is possible. The advantage of using the Poisson distribution is exemplified by the calculation of confidence limits for the incidence of hyperphenylalaninaemia, maple syrup urine disease and hypothyroidism. Furthermore, statistical comparisons between different screening programs are easily done.

Epidemiologic Methods↗
PubMed1982

Reversal or prevention of diuretic-induced alterations in serum lipoproteins with betablockers.

In 18 patients with essential hypertension serum low density lipoprotein cholesterol (LDL-C) was significantly (P less than 0.001) increased following short-term chlorthalidone therapy, but not during combination therapy with chlorthalidone and a betablocker. This tendency was similar in two subgroups which were studied with an inverse sequence of drug administration. In Group I (11 men), a 22% increase (P less than 0.01) in LDL-C during chlorthalidone monotherapy was restored to normal 6 weeks after addition to a betablocker to the diuretic; in Group II (5 men, 2 postmenopausal women) LDL-C levels were increased by 41% (P less than 0.05) 6 weeks after withdrawal of the betablocker from the combination therapy. No significant changes occurred during either the treatment phase in high density lipoprotein cholesterol or apoprotein B levels. It is concluded that combination therapy with a betablocker may prevent or reverse an increase in serum LDL-C associated with short-term chlorthalidone monotherapy.

Adolescent↗
PubMed1982

Reversal of diuretic-induced increases in serum low-density-lipoprotein cholesterol by the betablocker pindolol.

Seventeen patients with mild to moderate essential hypertension received during three consecutive 4 wk periods a matched placebo, the thiazide-like diuretic, clopamide in a low dosage of 5 mg/day, or this diuretic combined with the betablocker, pindolol in a low dosage of 10 mg/day. Compared to placebo conditions, clopamide monotherapy significantly increased serum low-density lipoprotein cholesterol (LDL-C) by 13% (p less than 0.025). Following addition of pindolol, serum LDL-C was restored to control values. These variations in serum LDL-C were unrelated to concomitant changes in blood pressure, plasma potassium, renin activity or aldosterone levels. Blood pressure in the supine position was reduced from 152/99 +/- 13/9 mm Hg (+ SD) to 141/93 +/- 15/7 mm Hg following diuretic-monotherapy and to 139/90 +/- 12/9 mm Hg following diuretic-betablocker combination treatment. These findings suggest that antihypertensive combination treatment with low doses of clopamide and pindolol is not only effective and well tolerated, but may also avoid the increase in serum LDL-C levels occurring when the thiazide-like diuretic is given alone.

Adult↗