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Biomedical subjects

J Hutzler

Publications and source records attributed to J Hutzler.

At least 19 recordsLinked to original sources
PubMed1994

Aerobic capacity and anaerobic threshold of wheelchair basketball players.

This study evaluated the aerobic capacity and anaerobic threshold of national level Israeli wheelchair basketball players. Subjects were tested working on a wheelchair rolling on a motor driven treadmill and on an arm cycle ergometer. Metabolic and cardiopulmonary parameters were measured during graded maximal exercise tests. Blood lactic acid (LA) concentration was measured in the intervals between loads during the test on the wheelchair. Heart rate (HR) and % heart rate reserve (%HRR) corresponding to the anaerobic threshold (4 mM blood LA) were evaluated while working on the wheelchair rolling on a motor driven treadmill. While working on the wheelchair the following peak exercise values were obtained: VO2 = 24.7 ml.kg/min, VE = 92.09 l/min HR = 181.5 b/min and R = 1.22. Values corresponding to the anaerobic threshold were found to be, HR = 139 b/min and %HRR = 57.02. Low correlations were obtained between peak exercise VO2 and VE measured while working on the wheelchair and those measured with arm cycle ergometer (r = 0.57 p = 0.137 and r = 0.4 p = 0.233 respectively). As athletes, subjects in the present study may be classified as having a low aerobic capacity and anaerobic threshold. It is also concluded that the ergometer type may have an important influence on test results.

Adult↗
PubMed1986

L-pipecolaturia in Zellweger syndrome.

Purified rat peroxisomes have been reported to oxidize D-pipecolic acid and the pipecolaturia of Zellweger syndrome has been attributed to the absence of peroxisomes. The logical consequences would be excesses of D-pipecolic acid in the urine of patients with Zellweger syndrome. The urine of two patients with Zellweger syndrome has been analyzed by complexing the pipecolic acid to copper-aspartame to separate the L- and D-isomers. L-Pipecolic acid constituted 100% and 78% of the total pipecolic acid in the two urines. The possibility of preferential retention of D-pipecolic acid was excluded by measuring renal excretion in two control subjects following administration of each isomer. The clearance of L-pipecolic acid was 1.1 and 0.2 ml/min and of D-pipecolic acid was 36.4 and 43.6 ml/min. These results do not support the contention that the pipecolaturia of Zellweger syndrome is the direct result of peroxisomal deficiencies.

Brain Diseases↗
PubMed1986

The significance of hyperpipecolatemia in Zellweger syndrome.

The plasma pipecolic acid concentration in two newborn infants with Zellweger syndrome at ages 4 and 10 days were 7.8 and 7.7 microM. Reported concentrations from this laboratory for normal newborn infants averaged 12 microM +/- 5.6 (SD). Both patients had the facies and severe hypotonia characteristic of the disease. Autopsy examination at age 6 days in one of these patients revealed the developmental microscopic abnormalities in brain, liver, and kidney that are associated with Zellweger syndrome. In three additional patients ages 3 1/2 weeks, 2 months, and 2 months, the pipecolic acid concentrations were 15, 17, and 25 microM. The concentrations increased to distinctly pathological levels on subsequent assays at a later age. It is concluded that the hyperpipecolatemia in Zellweger syndrome occurs postpartum and that the plasma concentrations may not be diagnostic early in life. The major manifestations of the disease, already evident at birth, cannot be attributed to pipecolatemia. Currently available data do not exclude the possibility of pipecolic acid accumulation in the brain where it has been reported to be a major metabolite of lysine. Hyperpipecolatemia of considerable degree is also consistently found in familial hyperlysinemia where it appears to be benign.

Abnormalities, Multiple↗
PubMed1983

The determination of pipecolic acid: method and results of hospital survey.

A method is described for the quantitative assay of pipecolic acid in biological fluids using column chromatography, with acid ninhydrin for color development. The technique permits measurement of plasma pipecolic acid in normal individuals with blood samples of 1 ml. The mean value in 29 pediatric patients, aged 4 months to 17 years, hospitalized with a variety of diagnoses was 2.1 mumol/1 +/- 1.6. Newborn infants had slightly elevated plasma levels with a mean of 12 mumol/1 +/- 5.6. Among the diagnostic categories, patients with liver disease were distinctive in commonly having levels at the upper limits of normal. In some cases, the levels were exceedingly high, reaching 78 mumol/1 in one fatal case.

Amino Acids↗
PubMed1983

Hair root analysis in X-linked ichthyosis.

Hair roots have been analysed in a large kindred with X-linked ichthyosis associated with steroid sulphatase deficiency. Enzyme activity in individual hair roots was assayed for the steroid sulphatase:neutral alpha-glucosidase ratio, the latter serving as an indicator of the general metabolic activity of the hair root. The distribution of the enzyme ratios in the individual hair roots in the heterozygotes described a normal curve suggesting origin from a single population of cells. The results differed strikingly from the irregular distribution of enzyme activities in hair roots of Lesch-Nyhan disease, where mosaicism occurs. It is suggested that the maternal and paternal genes for steroid sulphatase remain active in vivo in each cell in the hair root in apparent contradiction to the Lyon hypothesis. The observation is consistent with that previously reported for skin fibroblasts in vitro. Sulphatase activity in female controls was minimally greater than in males but the difference was not statistically significant.

Female↗
PubMed1983

The prognosis of hyperlysinemia: an interim report.

Ten patients with familial hyperlysinemia with lysine-ketoglutarate reductase deficiency, identified through newborn screening programs or family surveys, were selected for review. Ages ranged from 2 to 24 years when last examined. A low-protein diet had been administered to two patients, which reduced the plasma lysine levels from 20 mg per dl or more to about 12 mg per dl. The rest were untreated. Mental development was judged normal or above average in nine. Mildly subnormal performance in three was considered appropriate to family and social background. No adverse mental or physical effects could be attributed to the hyperlysinemia. A normal child has been born to a mother with hyperlysinemia, indicating that the fetus may develop normally despite exposure to high lysine levels.

Adolescent↗
PubMed1982

Comparative rates of metabolism of pipecolic acid in several animal species.

1. The rate of metabolism of pipecolic acid, measured in liver and kidney, varied 1000 fold among 10 animal species. Degradation of L-pipecolic acid by kidney in rat and mouse was 0.11 and 0.31 pmoles/min/mg protein, respectively; in monkey and human. 3.0 and 6.5; in guinea-pig and rabbit 101 and 106. 2. Activity with D-pipecolic acid was consistently 50-60% higher than the L-isomer except in the rabbit. 3. Degradation of L-lysine presumably through the saccharopine-alpha-aminoadipic acid pathway, was effective in all species, contrasting with the variable performance in the pipecolic acid-alpha-aminoadipic acid pathway.

Animals↗
PubMed1981

The metabolism of D- and L-pipecolic acid in the rabbit and rat.

The metabolism of D- and L-pipecolic acid has been investigated in rabbits and rats. A rapid evolution of 14CO2 followed the injection of either D- or L-pipe[6-14C]colic acid into rabbits. Rabbit kidney slices degraded to CO2 both isomers of lysine and of pipecolic acid. Rabbit liver was effective with only the L-isomers. In the rat, very little of injected L-pipecolic acid was catabolized to CO2, and large amounts were excreted unchanged into the urine, L-Lysine was efficiently metabolized to CO2 by rat liver and kidney slices but not D-lysine or either isomer of pipecolic acid. Rat kidney converted D-lysine to L-pipecolic acid. The L-isomer was identified by co-precipitation of the radioactive product with authentic compounds.

Amino Acids↗
PubMed1981

Sexual identity and prophylactic mastectomy.

The psychological adjustment of women following prophylactic mastectomy with reconstruction has not been evaluated. This study reviews this problem in 9 women chosen at random from the practice of two surgeons. The sexual identity of the women and its effect upon the outcome of their surgery was of particular interest. The surgeon's perception of problems of adjustment and the difference in the patient's and surgeon's evaluation of operative results were considered. The study included interviews with a psychiatrist, a questionnaire for the surgeon, and a subjective evaluation of operative results by both patient and surgeon. A high degree of psychopathology, particularly depression, was encountered. Most women had a relatively weak sexual identity preoperatively. In most instances the surgeon was not alerted to the patient's troubled feelings. Though psychopathology was evident, it does not seem to indicate that the patient will have difficulty accepting the results of surgery. We suggest that women who deny their sexuality might adjust to this surgery more easily. Psychiatric consultation appears to aid patient management.

Breast Neoplasms↗
PubMed1979

Hyperlysinemia with saccharopinuria due to combined lysine-ketoglutarate reductase and saccharopine dehydrogenase deficiencies presenting as cystinuria.

A 7-year-old boy with speech delay, hyperactive behavior, and minor neurologic abnormalities had been found in the past to have "intermittent cystinuria." A more detailed investigation revealed hyperlysinemia and hyperlysinuria, with lesser increases in urinary excretion of arginine and cystine. The plasma and urine abnormalities increased on a diet of 3 gm of protein/kg body weight/day. Saccharopine, a normal metabolite of lysine not found in the body fluids of normal people, was present in plasma, cerebrospinal fluid, and urine of the patient. Lysine-ketoglutarate reductase and saccharopine dehydrogenase activities were not detectable in extracts of cultured skin fibroblasts. Re-examination of the urine of previously studied cases of this double enzyme deficiency suggests that saccharopinuria of variable degree is the rule and not the exception.

Cells, Cultured↗
PubMed1979

Familial hyperlysinemia: enzyme studies, diagnostic methods, comments on terminology.

Enzyme assays of skin fibroblasts from five children with familial hyperlysinemia from unrelated families are added to the previous report of three children from two unrelated families. In all instances there was a deficiency in lysine-ketoglutarate reductase, saccharopine dehydrogenase, and saccharopine oxidoreductase activities. To complete the studies on the enzymes associated with familial hyperlysinemia, saccharopine oxidoreductase was partially purified from human liver and characterized. The activity did not separate from that of lysine-ketoglutarate reductase or saccharopine dehydrogenase. A simple screening test for familial hyperlysinemia is described based on the evolution of 14CO2 from lysine-14C by skin fibroblasts. The test differentiated, without overlap, seven patients with familial hyperlysinemia from control subjects. The relation of the two genetic entities involving lysine degradation, familial hyperlysinemia and saccharopinuria, is discussed. It is suggested that familial hyperlysinemia, type I, be applied to patients with major defects in lysine-ketoglutarate reductase and saccharopine dehydrogenase, and that familial hyperlysinemia, type II, to be used to designate patients in whom significant amounts of lysine-ketoglutarate reductase are retained. The nomenclature would be consistent with that of an analogous disease, orotic aciduria.

Amino Acid Metabolism, Inborn Errors↗
PubMed1977

Maple syrup urine disease: branched-chain keto acid decarboxylation in fibroblasts as measured with amino acids and keto acids.

Branched-chain keto acid decarboxylase activity in skin fibroblasts from control subjects and from patients with classical and variant forms of maple syrup urine disease (MSUD) was measured with leucine and alpha-ketoisocaproic acid. When the keto acid was used as substrate in high concentrations (more than 5 mM), the three groups overlapped extensively, even classical cases of MSUD exhibiting decarboxylase activity. With leucine as substrate, decarboxylase activity plateaued at about 1.5 mM, and the three groups could be clearly differentiated. Classical cases of MSUD had minimal or no decarboxylase activity.

Caproates↗
PubMed1976

Multiple enzyme defects in familial hyperlysinemia.

Lysine-ketoglutarate reductase (EC. 1.5.1.8) deficiency in skin fibroblasts has been previously reported in patients with familial hyperlysinemia, providing an adequate explanation for the biochemical derangements noted clinically. In the present study, analysis of liver obtained at autopsy from a patient with familial hyperlysinemia confirmed the lysine-ketoglutarate reductase deficiency but, unexpectedly, also revealed an absence of saccharopine dehydrogenase (EC. 1.5.1.9) and saccharopine oxidoreductase activity. Skin fibroblasts from two siblings with the disease and a third patient from an unrelated family were also deficient in all three enzymes (lysine-ketoglutarate reductase, average 9%; saccharopine dehydrogenase, average 4%; saccharopine oxidoreductase, less than 10% of normal). The possibility that saccharopine dehydrogenase is a substrate-inducible enzyme was investigated by maintaining normal skin fibroblasts in a medium with minimal lysine concentration, and exposing hyperlysinemic fibroblasts to elevated saccharopine concentrations. There was no significant modification in saccharopine dehydrogenase activity.

Adolescent↗
PubMed1975

Lysine-ketoglutarate reductase in human tissues.

Lysine-ketoglutarate reductase (saccharopine dehydrogenase (NADP+, lysine-forming) EC 1.5.1.8) from human liver has been partially purified and characterized. A spectrophotometric assay is described. The Michaelis constants have been determined for lysine (1.5-10-3 M), alpha-ketoglutarate (1-10-3 M) and NADPH (8-10-5 M). The pH optimum is 7.8. The enzyme is product inhibited. The specificity of the enzyme, response to inhibitors, pH and thermal stability are reported. Lysine-ketoglutarate reductase is present in high concentration in liver and heart, to a lesser degree in kidney and skin and in trace amounts in several other tissues. Saccharopine dehydrogenase (saccharopine dehydrogenase (NAD+, L-glutamate-forming) EC 1.5.1.9) was demonstrable only in liver and kidney. Lysine-ketoglutarate reductase reacts effectively with delta-hydroxylysine.

Humans↗
PubMed1973

Variant maple syrup urine disease in mother and daughter.

Intermittent MSUD in a mother and her daughter is reported. Fibroblast cultures were studied for branched-chain keto acid decarboxylase and results show that the mother has approximately 12% while the daughter has 5% of the normal enzyme activity. Other key members in the family were also studied for enzyme activity. It appears that the child has inherited an abnormal gene from her homozygous mother and another abnormal gene from her heterozygous father.A classification based on the degree of residual enzyme activity and protein tolerance places the mother in grade III and the daughter in grade II category. Classical MSUD, where the enzyme activity is less than 2% of normal, belongs to grade I.

Adult↗