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H Lenhartz

Publications and source records attributed to H Lenhartz.

6 recordsLinked to original sources
PubMed2004

S-Acetylglutathione normalizes intracellular glutathione content in cultured fibroblasts from patients with glutathione synthetase deficiency.

Glutathione synthetase deficiency is an autosomal recessive inherited metabolic defect in the gamma-glutamyl cycle. Decreased intracellular glutathione levels are one of the characteristic biochemical features. In this study we show that addition of S-acetylglutathione to the medium raised intracellular glutathione content in cultured fibroblasts from patients with glutathione synthetase deficiency. This has implications for the treatment of patients with this inborn error of metabolism.

Cells, Cultured↗
PubMed1998

The clinical manifestation of the kwashiorkor syndrome is related to increased lipid peroxidation.

Along with the onset of severe kwashiorkor symptoms, a 20-month-old child showed biochemical signs of markedly increased lipid peroxidation, with a decrease of plasma antioxidants and decreased proportions of polyunsaturated fatty acids in plasma and red cell phospholipids. Additionally, plasma concentrations of the lipid peroxidation products malondialdehyde and hexanal, as well as the urinary excretion of leukotriene E4, were found to be increased. All biochemical alterations normalized along with subsequent clinical improvement. These findings suggest that the extent of lipid peroxidation is strongly related to the severity of the kwashiorkor syndrome.

Aldehydes↗
PubMed1997

Plasma carotenoids in German children and adolescents.

UNLABELLED: Carotenoids are important antioxidants and precursors of vitamin A, but only few studies have been carried out on plasma carotenoid levels in paediatric age groups. Using high-performance liquid chromatography we analysed concentrations of four important carotenoids (alpha-carotene, beta-carotene, cryptoxanthin, lycopene) in 129 healthy German children and adolescents (81 boys, 48 girls; age 1-18 years). For all carotenoids analysed, no significant differences between girls and boys were found. alpha-Carotene values ranged from 0 mumol/l (below detection limits) to 0.73 mumol/l (0-395 micrograms/l), beta-carotene from 0.09 mumol/l to 2.68 mumol/l (48-1443 micrograms/l), lycopene from 0 mumol/l to 1.51 mumol/l (0-815 micrograms/l), and cryptoxanthin from 0 mumol/l to 0.30 mumol/l (0-164 micrograms/l), respectively. Data analyses according to age groups showed a tendency towards higher levels of alpha- and beta-carotene, and lower levels of lycopene in young children. These differences were significant when children younger than 4 years were compared with those above 8 and 12 years, respectively. The data presented may serve as reference values for studies on children with nutritional disorders and diseases associated with a risk of vitamin deficiencies. CONCLUSION: Carotenoids are important antioxidants and singlet oxygen scavengers. Plasma levels of alpha-carotene, beta-carotene, lycopene and cryptoxanthin were determined in 129 healthy German children and adolescents. Highest values were found for beta-carotene and lycopene.

Adolescent↗
PubMed1996

Influence of dialysis on plasma lipid peroxidation products and antioxidant levels.

In patients with end-stage renal failure (ESRF), the incidence of atherosclerosis and cancer is increased. The importance of lipid peroxidation (LPO) products in the pathogenesis of these complications has recently been emphasized. The LPO products malondialdehyde (MDA) and hexanal, lipophilic antioxidants and erythrocyte glutathione (GSH) were estimated in 10 pediatric hemodialysis (HD) patients before and after HD and in 11 peritoneal dialysis (CPD) patients. Before HD, MDA was elevated [median (interquartile range): 384.5 (110 to 501) nM; normal < 150 nM], whereas plasma hexanal levels were normal in all patients [130.5 (88 to 222) nM; < 320 nM]. HD decreased MDA concentrations on average by 88% but did not change hexanal levels. CPD patients exhibited high plasma MDA concentrations [371 (287 to 468) nM], whereas hexanal was in the low normal range [56 (51 to 81) nM]. Antioxidants were normal in both groups and unchanged during HD. GSH decreased slightly during HD. We hypothesize that MDA may accumulate in ESRF due to reduced plasma clearance. Our results argue against a general increase of LPO in uremia.

Adolescent↗
PubMedDate not supplied

Carotenoid supply in breast-fed and formula-fed neonates.

UNLABELLED: Carotenoids have various biological functions including their role as antioxidants. For humans fruits and vegetables are the only source of carotenoids. In the first months breast milk and/or formula preparations are the only nutrition for infants. To study the influence of nutrition on the plasma carotenoid profile in newborns, breast milk, different formula preparations, and the plasma of breast-fed (BF) and formula-fed (FF) newborns were analyzed by high-performance liquid chromatography. The method used allowed beta-carotene, alpha-carotene, lycopene, and beta-cryptoxanthine to be detected and all four were found in breast milk. In colostrum carotenoids were up to five times higher than in mature breast milk (P<0.05). In contrast, not all carotenoids could be found in formula preparations. Beta-carotene was detected in four out of eight, and beta-cryptoxanthine in three out of eight formula preparations. Lycopene and alpha-carotene were not detectable in any of the formula preparations. Four formula preparations did not contain any carotenoids. FF infants had different plasma carotenoid profiles compared to BF infants. beta-carotene was significantly lower in FF infants [14 (0-32) microg/l, median and interquartile ranges] than in infants after birth [24 (19-310) microg/l, P<0.05], and BF infants [32 (22-63) microg/l, P<0.05]. While newborns after birth had measurable plasma concentrations of lycopene (16 [14-18] microg/l) and of alpha-carotene [5 (0-8) microg/l), these carotenoids were no longer detectable in FF infants after day 14. CONCLUSION: FF and BF infants show significant biochemical differences in plasma carotenoid concentrations.

Antioxidants↗