Prefacethe supplementation of basal culture media with animal serum of different origins is essential for cell growth, metabolism, and to stimulate proliferation ("mitogenic effect"). the sera used most widely are bovine sera of adult or newborn animals, or of fetal origin. Fetal bovine serum (FBS) is a cocktail of most of the factors required for cell attachment, growth and proliferation and is thus used as an almost universal growth supplement effective for most types of human and animal (including insect) cells. However, the use of animal serum in cell culture also bears a number of disadvantages. these disadvantages can be seen either from -a theoretical, cell biological point of view, since serum in general is an ill-defined mixture of components in culture media, -from ethical perspectives in terms of animal protection arguments regarding the harvest and collection of FBS from bovine fetuses and -in terms of recent concerns about the global supply versus demand of FBS. As a consequence, a number of strategies were developed to reduce or replace the requirement for FBS in cell culture media. -Furthermore, recent advances in biomedicine, tissue engineering and (adult mesenchymal) stem cell-based therapy demand innovative serum-alternatives of human origin for autologous cell expansion and reimplantation. Also, for the biotechno-
Background: Two German sisters aged 14 and 17 y were admitted to the Tübingen eye hospital with a history of night blindness. In both siblings, plasma retinol binding protein (RBP) concentrations were below the limit of detection (< 0.6 mol/L) and plasma retinol concentrations were extremely low (0.19 mol/L). Interestingly, intestinal absorption of retinyl esters was normal. In addition, other factors associated with low retinol concentrations (eg, low plasma transthyretin or zinc concentrations or mutations in the transthyretin gene) were not present. Neither sibling had a history of systemic disease. Objective: Our aim was to investigate the cause of the retinol deficiency in these 2 siblings. Design: The 2 siblings and their mother were examined clinically, including administration of the relative-dose-response test, DNA sequencing of the RBP gene, and routine laboratory testing. Results: Genomic DNA sequence analysis revealed 2 point mutations in the RBP gene: a T-to-A substitution at nucleotide 1282 of exon 3 and a G-to-A substitution at nucleotide 1549 of exon 4. These mutations resulted in amino acid substitutions of asparagine for isoleucine at position 41 (Ile41→Asn) and of aspartate for glycine at position 74 (Gly74→Asp). Sequence analysis of cloned polymerase chain reaction products spanning exons 3 and 4 showed that these mutations were localized on different alleles. The genetic defect induced severe biochemical vitamin A deficiency but only mild clinical symptoms (night blindness and a modest retinal dystrophy without effects on growth). Conclusions: We conclude that the cellular supply of vitamin A to target tissues might be bypassed in these siblings via circulating retinyl esters, -carotene, or retinoic acid, thereby maintaining the health of peripheral tissues.Am J Clin Nutr 1999;69:931-6.
Abstract. Based on the observation that 5-aminolevulinic acid (ALA) induces the expression of heme oxygenase-1 (HO-1) in cultured melanoma cells, the role of HO-1 on the effectiveness of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) was examined. Transcriptional activation of the HO-1 gene is considered to be an adaptive response to oxidative and cellular stress and confers a protective capacity against cell and tissue injury, which could affect the responsiveness to ALA-PDT. A time-dependent accumulation (0-16 h) of protoporphyrin IX (PPIX) within melanoma cells was seen after incubation with ALA (0.5 mM ALA). Over the same time interval, a significant increase (up to 25-fold) in HO-1 protein expression was observed. Thus, the production and degradation of PPIX (via heme by HO-1) were simultaneously enhanced, leading to a reduced intracellular concentration of the photodynamically active substance PPIX. Diminishing HO-1 activity by the HO-1 inhibitor tin protoporphyrin IX (SnPPIX) significantly enhanced the formation of PPIX up to 1.8 fold. A further strong increase in HO-1 protein expression (up to 128-fold) was seen after ALA-PDT treatment. Induction of HO-1 is an essential step in the 'rescue response' of tumor cells. The pharmacological inhibition of HO-1 activity by SnPPIX leads to a considerable increase in the sensitivity of tumor cells to ALA-PDT treatment. At low radiation doses (0.42 J/cm 2 ), the percentages of death cells increased significantly from 7.3±1.3% to 43.7±6.4%. This effect could be further intensified by cellular depletion of HO-1 mRNA by siRNA. The combination of pharmacological inactivation of HO-1 with gene silencing led to an increase in the death rate of up to 54.1±8.6%. The results presented indicate that HO-1 can play a protective role against ALA-PDT mediated cytotoxicity so that a specific inhibition of HO-1 activity and/or expression might be used to increase the efficacy of ALA-based photodynamic therapy.
Adult patients with CF in particular showed distinct vitamin deficits and elevated indicators of oxidative stress in plasma, BMCs, and breath condensate along with a progression of clinical status. We suggest that early in life dietary habits should be improved and that innovative supplementation strategies should be applied to optimize the antioxidant status of patients with CF.
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