ABSTRACT
RATIONALE: Congenital glucose-galactose malabsorption (CGGM) is a rare, autosomal recessive, hereditary disease that usuallypresents in newborns. CGGM manifests as severe diarrhea, hyperosmolar dehydration, and malnutrition. It does not respond to routine treatment and often is life-threatening. PATIENT CONCERNS: We described a Chinese infant girl with refractory diarrhea, who suffered from severe dehydration and malnutrition even if with fluid replacement therapy and fed with several special formulas. DIAGNOSES: The genetic analysis identified CGGM with SLC5A1 mutations. c.1436Gâ>âC (p.R479T) was a novel mutation. INTERVENTIONS: The patient was managed by free-glucose and galactose formula, and then special low-carbohydrate dietary therapy. OUTCOMES: The patient improved immediately after starting a free-glucose and galactose formula, and kept healthy with special low-carbohydrate diet. She had been followed up with nutritional management for 20 months. LESSONS: This report highlights the importance of differential diagnosis of congenital diarrhea and enteropathies. For CGGM, free-glucose and galactose milk powder was the most effective treatment. Low-carbohydrate diet gradually introduced was still a great challenge that requires continuing guidance from child nutritionists and dietitians. Long-term nutrition management was extremely important to ensure the normal growth and development of children.
Subject(s)
Carbohydrate Metabolism, Inborn Errors/drug therapy , Diet, Carbohydrate-Restricted/methods , Infant Formula , Malabsorption Syndromes/drug therapy , Carbohydrate Metabolism, Inborn Errors/genetics , China , Female , Galactose , Glucose , Humans , Infant, Newborn , Malabsorption Syndromes/genetics , Mutation , Sodium-Glucose Transporter 1/geneticsABSTRACT
This study experimentally demonstrated that polyphosphate accumulating organisms (PAOs) losing the abilities of anaerobically synthesizing polyhydroxyalkanoates and aerobically taking up phosphate under Cu(II) presence was due to the inhibition of enzyme activities of acetyl-CoA synthases (ACS) and polyphosphate kinase (PPK), respectively. ACS activity tests showed the apparent maximum specific activity (Vmax) of ACS decreased with increasing Cu(II) concentration, revealing Cu(II) is a mixed inhibitor for ACS. Inhibition coefficients showed Cu(II) has a higher affinity for free ACS than for ACS-coenzyme A complex. PPK activity tests showed the Vmax substantially decreased with increasing Cu(II) concentration, revealing Cu(II) is also a mixed inhibitor for PPK. Inhibition coefficients showed Cu(II) more easily bound to free PPK than to PPK-Adenosine triphosphate complex. Experimental data also showed the aerobic mechanism of PAOs taking up phosphate was completely interrupted when 3mgL(-1) of Cu(II) was added.
