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Maple syrup urine disease (branched-chain oxoaciduria)
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop
Chronic management consists of restricting the intake of each of the three branched-chain amino acids to those essential for growth and no more. This type of dietary management is much more difficult than that of phenylketonuria. It requires very close regulation of an artificial diet and frequent access to an amino acid analyzer (Table 19.4). During rapid growth velocity (0 to 10 months), small infants usually require and tolerate 50–90, 30–60, and 20–50 mg/kg per day of L-leucine, L-valine, and L-isoleucine, respectively. These amounts will gradually decrease. After one year of age, requirements for L-leucine, L-valine, and L-isoleucine usually range around 20–40, 10–40, and 5–20 mg/kg per day. Thereafter, the tolerance of leucine decreases further with age down to 5–15 mg/kg per day in adults, whereas the requirements for L-valine, and L-isoleucine usually change only a little. The best results are seen in those in whom treatment has been initiated earliest. The largest experience with the management of this disease is that of Snyderman et al. [14, 95] and Morton et al. [20], and both have written that there can be little doubt about the beneficial effect of therapy in this disorder. Commercial products are available that are useful in the management of this disorder (Ketonex-Ross, MSUD-Mead-Johnson) [96].
DTI of Developmental and Pediatric Disorders
Published in Andrei I. Holodny, Functional Neuroimaging, 2019
Michael J. J. Kim, James M. Provenzale
Maple syrup urine disease (MSUD) is a rare autosomal recessive disorder of amino acid metabolism caused by a deficiency of the branched-chain α-ketoacid dehydrogenase complex (61). As a result, the three branched-chain amino acids (leucine, isoleucine, and valine) accumulate to toxic levels in the serum, urine, and cerebrospinal fluid. The classical form of the disease is seen in newborns and presents with lethargy, dystonia, feeding difficulties, a maple syrup odor of the urine, and ultimately coma. T2-weighted MR imaging typically reveals hyperintense lesions (62,63). To prevent the development of symptoms, early diagnosis is critical since intake of branched-chain amino acids must be restricted as soon as possible, as in other amino acid metabolic disorders.
The Role of the Clinical Laboratory in Nutritional Assessment
Published in Aruna Bakhru, Nutrition and Integrative Medicine, 2018
Compared to the general population, athletes require greater daily intakes of protein (in the range of 1.3–1.8 g/kg per day) to maximize muscle protein synthesis.3 Evaluation of the essential amino acids can reveal information about skeletal muscle status. For example, the branched-chain amino acids (BCAA) leucine, isoleucine, and valine increase the rates of protein synthesis and degradation in resting human muscle.4 BCAA levels may be informative about whether BCAA supplementation is affecting skeletal muscle protein synthesis signaling5 though there is no consensus that BCAA supplementation is effective.6 BCAA levels may also suggest if diet, stress, or disease states are affecting an athlete's skeletal muscles. There are a few other examples in which specific amino acids may indicate muscle status based on their roles in skeletal muscle. Other amino acids patterns (e.g., elevated tryptophan, decreased glutamine) have been associated with fatigue and suboptimal training capacity in athletes and suggest specific amino acids that may serve as biomarkers of muscle quality/status.7,8
Pharmacotherapeutic options for cancer cachexia: emerging drugs and recent approvals
Published in Expert Opinion on Pharmacotherapy, 2023
Lorena Garcia-Castillo, Giacomo Rubini, Paola Costelli
Protein intake should be in the range of 1–1,5 g/kg/day and to potentiate the stimulus of protein synthesis in muscle tissue, the supplementation with single amino acids or their derivatives has been extensively studied. Branched-chain amino acids (BCAA: leucine, isoleucine, and valine) are known to exert an anabolic effect on the skeletal muscle. Glutamine, a non-essential amino acid, has been included in nutritional supplementation approaches because of its contribution in preventing muscle wasting in cancer patients. Moreover, β-hydroxy-β-methylbutyrate (HMB), a leucine metabolite has been proposed to reduce protein degradation rates [22,23]. An improved hand-grip strength was reported in advanced lung cancer patients after supplementation with arginine, glutamine, and HMB. However, no significant effects on lean body mass were observed [24]. A recent review of the effects exerted by HMB administration on cancer patients concluded that apparently there are positive hints in terms of muscle mass and function, although the authors recognize that this issue deserves additional clinical investigations [25].
Surface atomic arrangement of nanomaterials affects nanotoxicity
Published in Nanotoxicology, 2021
Kaiwen Li, Zhongwei Wang, Hui Zeng, Jing Sun, Yue Wang, Qixing Zhou, Xiangang Hu
Metabolomics analysis provides a global view of the biological response to external stimuli (Krivitsky et al. 2019; Grintzalis et al. 2019). Branched chain amino acids (BCAAs) such as valine, leucine, isoleucine and threonine play a crucial role in skeletal muscle, affecting muscle morphology and function in living organisms (Wang et al. 2016). The main function of the aminoacyl-tRNAs is in protein synthesis (Raina and Ibba 2014). Compared to 1 T-MoS2, 2H-MoS2 upregulated BCAAs biosynthesis and aminoacyl-tRNA biosynthesis, indicating a stress response (Figure 6). Arginine is a nutritionally essential amino acid for embryonic survival and maintenance of vascular tone (Wu et al. 2009), and downregulated by both 1 T-MoS2 and 2H-MoS2. Compared to 1 T-MoS2, 2H-MoS2 downregulated glyoxylate and dicarboxylate metabolism, where glyoxylate and dicarboxylate metabolism are energy metabolism processes (Germain et al. 2017), explaining the higher toxicity of 2H-MoS2.
Influence of diet and metabolism on hematopoietic stem cells and leukemia development following ionizing radiation exposure
Published in International Journal of Radiation Biology, 2019
Melis Karabulutoglu, Rosemary Finnon, Tatsuhiko Imaoka, Anna A. Friedl, Christophe Badie
Arginine can either stimulate or inhibit growth of tumors within distinct rat sarcoma models (Levy et al. 1954), and more recently, various groups have reported that arginine deprivation has influence against various cancer cell types including pancreatic, prostate, breast cancers as well as primary AML, through altering distinct signaling pathways (Bowles et al. 2008; Kim et al. 2009; Daylami et al. 2014; Qiu et al. 2014; Miraki-Moud et al. 2015). As mentioned earlier, dietary-valine depletion resulted in alterations in both human and mouse HSC maintenance in vitro (Taya et al. 2016). As a consequence, valine or arginine depletion could possibly reduce the incidence of radiation-induced leukemogenesis, by altering the frequency and maintenance of HSCs. Diets depleted in certain individual AAs may provide a feasible approach for mitigating the effect of IR exposure, yet there is no information available. For future applications, it is critical to consider numerous features (e.g. low toxicity, nonimmunogenic, fast-acting) while developing an AA-depleting agent against cancer.