Treatment and management for children with urea cycle disorder in chronic stage. / å°¿ç´ å¾ªçŽ¯éšœç¢æ‚£å„¿æ ¢æ€§æœŸæ²»ç–—å’Œç®¡ç†.

Urea cycle disorder (UCD) is a group of inherited metabolic diseases with high disability or fatality rate, which need long-term drug treatment and diet management. Except those with Citrin deficiency or liver transplantation, all pediatric patients require lifelong low protein diet with safe levels of protein intake and adequate energy and lipids supply for their corresponding age; supplementing essential amino acids and protein-free milk are also needed if necessary. The drugs for long-term use include nitrogen scavengers (sodium benzoate, sodium phenylbutyrate, glycerol phenylbutyrate), urea cycle activation/substrate supplementation agents (N-carbamylglutamate, arginine, citrulline), etc. Liver transplantation is recommended for pediatric patients not responding to standard diet and drug treatment, and those with severe progressive liver disease and/or recurrent metabolic decompensations. Gene therapy, stem cell therapy, enzyme therapy and other novel technologies may offer options for treatment in UCD patients. The regular biochemical assessments like blood ammonia, liver function and plasma amino acid profile are needed, and physical growth, intellectual development, nutritional intake should be also evaluated for adjusting treatment in time.

Long-term survival of a patient with acute neonatal-onset metabolic encephalopathy with carbamoyl phosphate synthetase 1 deficiency.

OBJECTIVE: Long-term survival of patients with neonatal-onset carbamoyl-phosphate synthetase 1 deficiency (CPS1D), an autosomal recessive disorder characterized by repeated, life-threatening hyperammonemia, is rare. We describe the diagnosis and clinical management of a teenager with neonatal-onset CPS1D who did not undergo therapeutic liver transplantation. CASE REPORT: Following emergent neonatal therapy, the patient was diagnosed with CPS1D based on clinical, radiological, biochemical and genetic analyses. Her clinical course, neurobehavioral development and therapeutic interventions are presented and discussed. RESULTS: Born from nonconsanguineous parents, the proband underwent phototherapy for neonatal jaundice, associated with acute encephalopathy, apnea and cerebral edema. Based on blood and urinary biochemical abnormalities, neonatal-onset CPS1D was diagnosed. Her hyperammonemia was corrected by hemodialysis, followed by sodium benzoate, L-arginine, levocarnitine and protein-free diet therapy. Because of a relapse and persistent neurobehavioral regression by age 1, a planned liver transplantation was cancelled. At age 10, sodium phenylbutyrate was substituted as ammonia scavenger. Genetic testing revealed compound heterozygote c.2359C>T (R787X) and c.236+6T>C variants of CPS1, confirming her diagnosis. Despite severe neurological sequelae, the patient is 16 and in stable condition. CONCLUSIONS: Our case suggests that early hemodialysis and pharmacologic interventions for acute neonatal hyperammonemia can improve the prognosis of patients with neonatal-onset CPS1D.

Sodium Benzoate, a Food Additive and a Metabolite of Cinnamon, Enriches Regulatory T Cells via STAT6-Mediated Upregulation of TGF-ß.

Upregulation and/or maintenance of regulatory T cells (Tregs) during autoimmune insults may have therapeutic efficacy in autoimmune diseases. Earlier we have reported that sodium benzoate (NaB), a metabolite of cinnamon and a Food and Drug Administration-approved drug against urea cycle disorders, upregulates Tregs and protects mice from experimental allergic encephalomyelitis, an animal model of multiple sclerosis. However, mechanisms by which NaB increases Tregs are poorly understood. Because TGF-ß is an important inducer of Tregs, we examined the effect of NaB on the status of TGF-ß. In this study, we demonstrated that NaB induced the expression of TGF-ß mRNA and protein in normal as well as proteolipid protein-primed splenocytes. The presence of a consensus STAT6 binding site in the promoter of the TGF-ß gene, activation of STAT6 in splenocytes by NaB, recruitment of STAT6 to the TGF-ß promoter by NaB, and abrogation of NaB-induced expression of TGF-ß in splenocytes by small interfering RNA knockdown of STAT6 suggest that NaB induces the expression of TGF-ß via activation of STAT6. Furthermore, we demonstrated that blocking of TGF-ß by neutralizing Abs abrogated NaB-mediated protection of Tregs and experimental allergic encephalomyelitis. These studies identify a new function of NaB in upregulating TGF-ß via activation of STAT6, which may be beneficial in MS patients.

Emerging trends in management of propionic acidemia.

OBJETIVO: To evaluate the therapeutic agents used during metabolic crises and in long-term management of patients with propionic acidemia (PA). MATERIALS AND METHODS: The records of PA patients were retrospectively evaluated. RESULTS: The study group consisted of 30 patients with 141 admissions. During metabolic crises, hyperammonemia was found in 130 (92%) admissions and almost all patients were managed with normal saline, ≥ 10% dextrose, and restriction of protein intake. In 56 (40%) admissions, management was done in intensive care unit, 31 (22%) with mechanical ventilation, 10 (7%) with haemodialysis, 16 (11%) with vasopressor agents, and 12 (9%) with insulin. In the rescue procedure, L-carnitine was used in 135 (96%) patients, sodium bicarbonate in 116 (82%), sodium benzoate in 76 (54%), and metronidazole in 10 (7%), biotin in about one-quarter, L-arginine in one third, and antibiotics in three-quarter of the admissions. Blood/packed RBCs were used in 28 (20%) patients, platelets in 26 (18%), fresh frozen plasma in 8 (6%), and granulocyte-colony stimulating factors in 10 (7%) admissions. All patients were managed completely/partially with medical nutrition formula plus amino acid mixture, vitamins and minerals. For long-term management 24 (80%) patients were on L-carnitine, 22 (73%) on sodium benzoate, 6 (20%) on biotin, one half on alkaline therapy and 4 (13%) on regular metronidazole use. Almost all patients were on medical formula and regular follow-up. CONCLUSION: Aggressive and adequate management of acute metabolic crises with restriction of protein intake, stabilization of patient, reversal of catabolism, and removal of toxic metabolites are essential steps. Concerted efforts to ensure adequate nutrition, to minimize the risk of acute decompensation and additional therapeutic advances are imperative to improve the outcome of PA patients.

Emerging trends in management of propionic acidemia / Tendências emergentes no manejo da academia propiônica

Objetivo : To evaluate the therapeutic agents used during metabolic crises and in long-term management of patients with propionic acidemia (PA).Materials and methods : The records of PA patients were retrospectively evaluated.Results : The study group consisted of 30 patients with 141 admissions. During metabolic crises, hyperammonemia was found in 130 (92%) admissions and almost all patients were managed with normal saline, ≥ 10% dextrose, and restriction of protein intake. In 56 (40%) admissions, management was done in intensive care unit, 31 (22%) with mechanical ventilation, 10 (7%) with haemodialysis, 16 (11%) with vasopressor agents, and 12 (9%) with insulin. In the rescue procedure, L-carnitine was used in 135 (96%) patients, sodium bicarbonate in 116 (82%), sodium benzoate in 76 (54%), and metronidazole in 10 (7%), biotin in about one-quarter, L-arginine in one third, and antibiotics in three-quarter of the admissions. Blood/packed RBCs were used in 28 (20%) patients, platelets in 26 (18%), fresh frozen plasma in 8 (6%), and granulocyte-colony stimulating factors in 10 (7%) admissions. All patients were managed completely/partially with medical nutrition formula plus amino acid mixture, vitamins and minerals. For long-term management 24 (80%) patients were on L-carnitine, 22 (73%) on sodium benzoate, 6 (20%) on biotin, one half on alkaline therapy and 4 (13%) on regular metronidazole use. Almost all patients were on medical formula and regular follow-up.Conclusion : Aggressive and adequate management of acute metabolic crises with restriction of protein intake, stabilization of patient, reversal of catabolism, and removal of toxic metabolites are essential steps. Concerted efforts to ensure adequate nutrition, to minimize the risk of acute decompensation and additional therapeutic advances are imperative to improve the outcome of PA patients. Arq Bras Endocrinol Metab. 2014;58(3):237-42.

Objetivo : Avaliar os agentes terapêuticos usados durante as crises metabólicas e para o manejo de longo prazo de pacientes com academia propiônica (AP).Materiais e métodos : Avaliação retrospectiva das fichas médicas de pacientes com AP.Resultados : O grupo estudado consistiu de 30 pacientes com 141 hospitalizações. Durante as crises metabólicas, a hiperamonemia foi observada em 130 (92%) pacientes hospitalizados e quase todos foram tratados com solução salina regular, ≥ 10% dextrose e restrição da ingestão de proteína. Em 56 (40%) das hospitalizações, o manejo foi feito na unidade de terapia intensiva, 31(22%) com ventilação mecânica, 10 (7%) com hemodiálise, 16 (11%) com vasopressores e 12 (9%) com insulina. Para o resgate, a L-carnitina foi usada em 135 (96%) pacientes, o bicarbonato de sódio em 116 (82%), o benzoato de sódio em 76 (54%), o metronidazole em 10 (7%), a biotina em cerca de um quarto, a L-arginina em um quarto e antibióticos em três quartos dos pacientes hospitalizados. Sangue/concentrado de hemácias foram usados em 28 (20%), plaquetas em 26 (18%), plasma fresco congelado em 8 (6%) e fatores estimulantes de colônias de granulócitos em 10 (7%) pacientes hospitalizados. Todos os pacientes foram manejados completamente/parcialmente com fórmula de nutrição hospitalar mais uma mistura de aminoácidos, vitaminas e minerais. Para o manejo de longo prazo, 24 (80%) dos pacientes foram tratados com L-carnitina, 22 (73%) com benzoato de sódio, 6 (20%) com biotina, a metade com tratamento alcalino e 4 (13%) com uso regular de metronidazole. Quase todos os pacientes foram tratados com fórmulas médicas e acompanhamento regular.Conclusão : O manejo adequado e agressivo de crises metabólicas com restrição da ingestão de proteína, ...

Guanidinoacetate methyltransferase (GAMT) deficiency: outcomes in 48 individuals and recommendations for diagnosis, treatment and monitoring.

We collected data on 48 patients from 38 families with guanidinoacetate methyltransferase (GAMT) deficiency. Global developmental delay/intellectual disability (DD/ID) with speech/language delay and behavioral problems as the most affected domains was present in 44 participants, with additional epilepsy present in 35 and movement disorder in 13. Treatment regimens included various combinations/dosages of creatine-monohydrate, l-ornithine, sodium benzoate and protein/arginine restricted diets. The median age at treatment initiation was 25.5 and 39 months in patients with mild and moderate DD/ID, respectively, and 11 years in patients with severe DD/ID. Increase of cerebral creatine and decrease of plasma/CSF guanidinoacetate levels were achieved by supplementation with creatine-monohydrate combined with high dosages of l-ornithine and/or an arginine-restricted diet (250 mg/kg/d l-arginine). Therapy was associated with improvement or stabilization of symptoms in all of the symptomatic cases. The 4 patients treated younger than 9 months had normal or almost normal developmental outcomes. One with inconsistent compliance had a borderline IQ at age 8.6 years. An observational GAMT database will be essential to identify the best treatment to reduce plasma guanidinoacetate levels and improve long-term outcomes.

Overnight storage of removable dentures in alkaline peroxide-based tablets affects biofilm mass and composition.

BACKGROUND: Clinical guidelines for denture care are available, but evidence for optimal nocturnal storage is scarce. The aim of the study was to compare the role of the overnight storage state on plaque growth and composition on acrylic removable dentures. METHODS: In a parallel-group randomized controlled trial of 51 institutionalized participants, 3 denture overnight preservation methods were considered: (i) in water, (ii) dry or (iii) in water with added alkaline peroxide-based cleansing tablet. Biofilm samples were taken on day 7 (developing biofilm - dBF) and day 14 (maturing biofilm - mBF) from a mechanically uncleaned, standardized region, situated distally to the second lower premolars. Total and individual levels of selected perio-pathogenic and commensal species (n=20), and of Candida albicans were calculated by PCR. Differences between storage conditions (water/dry/tablet) and between the samples (dBF/mBF) were assessed by means of unpaired and paired t-tests respectively, with α=5%. RESULTS: Overnight denture storage with cleansing tablet significantly decreased the total bacterial level of dBF and mBF up to 13.8%. Fn, Ec, Cs, Sc, Ao and Vp counts were particularly affected by tablet care. Significant lower amounts of Candida albicans for tablet storage compared to water preservation were recorded in dBF and mBF (-69.3 ± 3.8% and -75.9 ± 3.2% respectively). The mass and pathogenicity of dBF and mBF was equal, irrespective of the overnight storage intervention. CONCLUSIONS: The use of cleansing tablets for acrylic removable denture overnight storage reduces denture biofilm mass and pathogenicity compared to dry and water preservation, and may contribute to the overall systemic health. CLINICAL SIGNIFICANCE: Evidence-based clinical guidelines for overnight storage of removable acrylic dentures are lacking. The findings of this study indicate that alkaline peroxide-based cleansing tablets decrease bacterial and Candida levels in denture biofilms in case of poor oral hygiene. This provides evidence for a clinical guideline to minimize microbial load of dentures, thereby reducing associated systemic health risks.

Up-regulation of neurotrophic factors by cinnamon and its metabolite sodium benzoate: therapeutic implications for neurodegenerative disorders.

This study underlines the importance of cinnamon, a widely-used food spice and flavoring material, and its metabolite sodium benzoate (NaB), a widely-used food preservative and a FDA-approved drug against urea cycle disorders in humans, in increasing the levels of neurotrophic factors [e.g., brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3)] in the CNS. NaB, but not sodium formate (NaFO), dose-dependently induced the expression of BDNF and NT-3 in primary human neurons and astrocytes. Interestingly, oral administration of ground cinnamon increased the level of NaB in serum and brain and upregulated the levels of these neurotrophic factors in vivo in mouse CNS. Accordingly, oral feeding of NaB, but not NaFO, also increased the level of these neurotrophic factors in vivo in the CNS of mice. NaB induced the activation of protein kinase A (PKA), but not protein kinase C (PKC), and H-89, an inhibitor of PKA, abrogated NaB-induced increase in neurotrophic factors. Furthermore, activation of cAMP response element binding (CREB) protein, but not NF-κB, by NaB, abrogation of NaB-induced expression of neurotrophic factors by siRNA knockdown of CREB and the recruitment of CREB and CREB-binding protein to the BDNF promoter by NaB suggest that NaB exerts its neurotrophic effect through the activation of CREB. Accordingly, cinnamon feeding also increased the activity of PKA and the level of phospho-CREB in vivo in the CNS. These results highlight a novel neutrophic property of cinnamon and its metabolite NaB via PKA - CREB pathway, which may be of benefit for various neurodegenerative disorders.

Hiperamonemia en niños: clasificación y opciones terapéuticas / Hyperammonaemia in children: classification and therapeutic options

La hiperamonemia se presenta en forma secundaria por aumento en la producción de amonio, como en la hemorragia gastrointestinal o disminución de la eliminación, como ocurre en errores innatos del metabolismo, principalmente en aquellos con defectos en el ciclo de la urea, insuficiencia hepática o fármacos. Clasificar la hiperamonemia y reportar las opciones terapéuticas en niños, su abordaje clínico y revisión de la literatura. Estudio prospectivo, descriptivo y transversal de niños con hiperamonemia. Variables: edad, género, etiología, niveles de amonio, clínica, tratamiento. 21 pacientes, 12 (57,12%) varones y 9 (42,88%) hembras. Edad promedio 3,91 años (rango:<1mes-14 años). Amonio promedio general 214,66 mmol/l (rango:110-980), clasificados según severidad: sin insuficiencia hepática 11/21 con promedio de amonio 99,44 y 201 mmol/l en hiperamonemia leve y moderada respectivamente. Clínica y laboratorio de insuficiencia hepática en 10/21 con promedio de amonio de 114,44, 287,51 y 756,66 en leve, moderada y severa hiperamonemia, con una diferencia significativa entre el nivel de amonio y la presencia o ausencia de insuficiencia hepática (p<0,0001); 5/10 con insuficiencia hepática ingresaron a terapia intensiva, 4 de ellos presentaron encefalopatía hepática, un paciente fallecido. Etiología: Error innato del metabolismo 33,33%, toxicidad por medicamentos 23,80%, hepatitis viral A fulminante 19,04% y otros virus 9,52%, hepatitis autoinmune 4,76% y urosepsis 4,76%. En los casos leves-moderados se administró lactulosa dosis respuesta vía oral 19/21 y por enema rectal 7/21 con L-carnitina en 15/21 y en Hiperamonemia severa adicionalmente Benzoato de sodio en 4/21 y hubo indicación de hemodiálisis en 3 pacientes. Restricción proteica en todos, vitaminoterapia y 6 niños tratados con ácido ursodeoxicólico. La hiperamonemia es multifactorial, requiere diagnóstico temprano, la clasificación de severidad permite el tratamiento oportuno para evitar complicaciones....

Hyperammonaemia occurs secondarily by increased production of ammonia, as gastrointestinal bleeding or decreased elimination, as occurs in inborn errors of metabolism, especially in those with defects in the urea cycle, liver failure or drugs. To classify the report hyperammonaemia and therapeutic options in children, its clinical approach and review of the literature. Prospective, descriptive and transversal children with hyperammonaemia. Variables: age, gender, etiology, ammonia levels, clinical treatment. 21 patients, 12 (57,12%) males and 9 (42,88%) females. Mean age 3,91 years (range: <1m-14a). ammonium 214,66 mmol / l (range :110-980), classified according to severity: no hepatic impairment 11/21 with 99,44 average ammonium and 201 mmol / l in Hyperammoanemia mild and moderate respectively. Clinical and laboratory liver failure 10/21 with ammonium averaging 114,44, 287,51 and 756,66 as mild, moderate and severe hyperammonemia, with a significant difference between the level of ammonia and the presence or absence of liver failure (p < 0,0001), 5/10 with liver failure admitted to intensive care, 4 of them had hepatic encephalopathy, a patient died. Etiology: An inborn error of metabolism 33,33%, 23,80% drug toxicity, fulminant viral hepatitis and other viruses 19,04% 9,52% 4,76% autoimmune hepatitis and urosepsis 4,76%. In mild-moderate cases were given oral lactulose Dose 19/21 and by enema rectal 7/21 with L-carnitine in 15/21 and further severe Hyperammonemia sodium benzoate 4/21 and was indication of hemodialysis in 3 patients. Protein restriction at all, vitamin therapy and 6 children treated with ácidoursodeoxicólico. Hyperammonemia is multifactorial, requires early diagnosis, classification of severity allows early treatment to avoid complications and development of irreversible neurological sequelae

The first Korean case of lysinuric protein intolerance: presented with short stature and increased somnolence.

Lysinuric protein intolerance (LPI) is a rare inherited metabolic disease, caused by defective transport of dibasic amino acids. Failure to thrive, hepatosplenomegaly, hematological abnormalities, and hyperammonemic crisis are major clinical features. However, there has been no reported Korean patient with LPI as of yet. We recently encountered a 3.7-yr-old Korean girl with LPI and the diagnosis was confirmed by amino acid analyses and the SLC7A7 gene analysis. Her initial chief complaint was short stature below the 3rd percentile and increased somnolence for several months. Hepatosplenomegaly was noted, as were anemia, leukopenia, elevated levels of ferritin and lactate dehydrogenase, and hyperammonemia. Lysine, arginine, and ornithine levels were low in plasma and high in urine. The patient was a homozygote with a splicing site mutation of IVS4+1G > A in the SLC7A7. With the implementation of a low protein diet, sodium benzoate, citrulline and L-carnitine supplementation, anemia, hyperferritinemia, and hyperammonemia were improved, and normal growth velocity was observed.

Hyperammonemia in a patient with late-onset ornithine carbamoyltransferase deficiency.

Ornithine carbamoyltransferase (OTC) deficiency is a urea cycle disorder that causes the accumulation of ammonia, which can lead to encephalopathy. Adults presenting with hyperammonemia who are subsequently diagnosed with urea cycle disorders are rare. Herein, we report a case of a late-onset OTC deficient patient who was successfully treated with arginine, benzoate and hemodialysis. A 59-yr-old man was admitted to our hospital with progressive lethargy and confusion. Although hyperammonemia was suspected as the cause of the patient's mental changes, there was no evidence of chronic liver disease. A plasma amino acid and urine organic acid analysis revealed OTC deficiency. Despite the administration of a lactulose enema, the patient's serum ammonia level increased and he remained confused, leading us to initiate acute hemodialysis. After treatment with arginine, sodium benzoate and hemodialysis, the patient's serum ammonia level stabilized and his mental status returned to normal.

Argininosuccinate lyase deficiency.

The urea cycle consists of six consecutive enzymatic reactions that convert waste nitrogen into urea. Deficiencies of any of these enzymes of the cycle result in urea cycle disorders (UCDs), a group of inborn errors of hepatic metabolism that often result in life-threatening hyperammonemia. Argininosuccinate lyase (ASL) catalyzes the fourth reaction in this cycle, resulting in the breakdown of argininosuccinic acid to arginine and fumarate. ASL deficiency (ASLD) is the second most common UCD, with a prevalence of ~1 in 70,000 live births. ASLD can manifest as either a severe neonatal-onset form with hyperammonemia within the first few days after birth or as a late-onset form with episodic hyperammonemia and/or long-term complications that include liver dysfunction, neurocognitive deficits, and hypertension. These long-term complications can occur in the absence of hyperammonemic episodes, implying that ASL has functions outside of its role in ureagenesis and the tissue-specific lack of ASL may be responsible for these manifestations. The biochemical diagnosis of ASLD is typically established with elevation of plasma citrulline together with elevated argininosuccinic acid in the plasma or urine. Molecular genetic testing of ASL and assay of ASL enzyme activity are helpful when the biochemical findings are equivocal. However, there is no correlation between the genotype or enzyme activity and clinical outcome. Treatment of acute metabolic decompensations with hyperammonemia involves discontinuing oral protein intake, supplementing oral intake with intravenous lipids and/or glucose, and use of intravenous arginine and nitrogen-scavenging therapy. Dietary restriction of protein and dietary supplementation with arginine are the mainstays in long-term management. Orthotopic liver transplantation (OLT) is best considered only in patients with recurrent hyperammonemia or metabolic decompensations resistant to conventional medical therapy.

The First Korean Case of Lysinuric Protein Intolerance: Presented with Short Stature and Increased Somnolence

Lysinuric protein intolerance (LPI) is a rare inherited metabolic disease, caused by defective transport of dibasic amino acids. Failure to thrive, hepatosplenomegaly, hematological abnormalities, and hyperammonemic crisis are major clinical features. However, there has been no reported Korean patient with LPI as of yet. We recently encountered a 3.7-yr-old Korean girl with LPI and the diagnosis was confirmed by amino acid analyses and the SLC7A7 gene analysis. Her initial chief complaint was short stature below the 3rd percentile and increased somnolence for several months. Hepatosplenomegaly was noted, as were anemia, leukopenia, elevated levels of ferritin and lactate dehydrogenase, and hyperammonemia. Lysine, arginine, and ornithine levels were low in plasma and high in urine. The patient was a homozygote with a splicing site mutation of IVS4+1G > A in the SLC7A7. With the implementation of a low protein diet, sodium benzoate, citrulline and L-carnitine supplementation, anemia, hyperferritinemia, and hyperammonemia were improved, and normal growth velocity was observed.

Hyperammonemia in a Patient with Late-Onset Ornithine Carbamoyltransferase Deficiency

Ornithine carbamoyltransferase (OTC) deficiency is a urea cycle disorder that causes the accumulation of ammonia, which can lead to encephalopathy. Adults presenting with hyperammonemia who are subsequently diagnosed with urea cycle disorders are rare. Herein, we report a case of a late-onset OTC deficient patient who was successfully treated with arginine, benzoate and hemodialysis. A 59-yr-old man was admitted to our hospital with progressive lethargy and confusion. Although hyperammonemia was suspected as the cause of the patient's mental changes, there was no evidence of chronic liver disease. A plasma amino acid and urine organic acid analysis revealed OTC deficiency. Despite the administration of a lactulose enema, the patient's serum ammonia level increased and he remained confused, leading us to initiate acute hemodialysis. After treatment with arginine, sodium benzoate and hemodialysis, the patient's serum ammonia level stabilized and his mental status returned to normal.

Immunomodulation of experimental allergic encephalomyelitis by cinnamon metabolite sodium benzoate.

Experimental allergic encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS), the most common human demyelinating disease of the central nervous system. Sodium benzoate (NaB), a metabolite of cinnamon and a FDA-approved drug against urea cycle disorders in children, is a widely used food additive, which is long known for its microbicidal effect. However, recent studies reveal that apart from its microbicidal effects, NaB can also regulate many immune signaling pathways responsible for inflammation, glial cell activation, switching of T-helper cells, modulation of regulatory T cells, cell-to-cell contact, and migration. As a result, NaB alters the neuroimmunology of EAE and ameliorates the disease process of EAE. In this review, we have made an honest attempt to analyze these newly-discovered immunomodulatory activities of NaB and associated mechanisms that may help in considering this drug for various inflammatory human disorders including MS as primary or adjunct therapy.

Inhibition of D-amino-Acid oxidase activity induces pain relief in mice.

(1). We investigated the effects of inhibiting D: -amino-acid oxidase (DAO) activity on nociceptive responses through the use of mutant ddY/DAO(-) mice, which lack DAO activity, and through the application of a selective inhibitor of DAO, sodium benzoate, in the tail flick test, hot-plate test, formalin test, and acetic acid-induced writhing test. (2). Compared with normal ddY/DAO+ mice, ddY/DAO(- )mice showed significantly prolonged tail withdrawal latency in the tail flick test and licking/jumping latency in the hot-plate test, as well as significantly reduced duration of licking/biting in the late phase of the formalin test and the number of abdominal writhing in the acetic acid-induced writhing test. (3). In addition, we investigated the effects of sodium benzoate in Kunming mice having normal DAO activity. (4). Intravenous administration of sodium benzoate (400 mg/kg) significantly inhibited pain responses of the late phase of the formalin test and abdominal writhing responses in the acetic acid-induced writhing test, with no effects on the early phase flinch responses in the formalin test, nociceptive responses in the tail flick test, or hot-plate test. (5). These results suggest that DAO acts as a pro-nociceptive factor in pain, particularly chronic pain, transmission and modulation, and may be a target for pain treatment.

Nutrient intake in lysinuric protein intolerance.

Lysinuric protein intolerance (LPI) is a rare autosomal recessive disorder characterized by defective transport of cationic amino acids. Poor intestinal absorption and increased renal loss of arginine, ornithine and lysine lead to low plasma concentrations of these amino acids and, subsequently, to impaired urea cycle function. The patients therefore have decreased nitrogen tolerance, which may lead to hyperammonaemia after ingestion of normal amounts of dietary protein. As a protective mechanism, most patients develop strong aversion to protein-rich foods early in life. Oral supplementation with citrulline, which is absorbed normally and metabolized to arginine and ornithine, improves protein tolerance to some extent, as do sodium benzoate and sodium phenylbutyrate also used by some patients. Despite effective prevention of hyperammonaemia, the patients still consume a very restricted diet, which may be deficient in energy, essential amino acids and some vitamins and minerals. To investigate the potential nutritional problems of patients with lysinuric protein intolerance, 77 three- to four-day food records of 28 Finnish LPI patients aged 1.5-61 years were analysed. The data suggest that the patients are clearly at risk for many nutritional deficiencies, which may contribute to their symptoms. Their diet is highly deficient in calcium, vitamin D, iron and zinc. Individualized nutritional supplementation accompanied by regular monitoring of dietary intake is therefore an essential part of the treatment of LPI.

Sodium benzoate, a food additive and a metabolite of cinnamon, modifies T cells at multiple steps and inhibits adoptive transfer of experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE) is the animal model for multiple sclerosis. This study explores a novel use of sodium benzoate (NaB), a commonly used food additive and a Food and Drug Administration-approved nontoxic drug for urea cycle disorders, in treating the disease process of relapsing-remitting EAE in female SJL/J mice. NaB, administered through drinking water at physiologically tolerable doses, ameliorated clinical symptoms and disease progression of EAE in recipient mice and suppressed the generation of encephalitogenic T cells in donor mice. Histological studies reveal that NaB effectively inhibited infiltration of mononuclear cells and demyelination in the spinal cord of EAE mice. Consequently, NaB also suppressed the expression of proinflammatory molecules and normalized myelin gene expression in the CNS of EAE mice. Furthermore, we observed that NaB switched the differentiation of myelin basic protein-primed T cells from Th1 to Th2 mode, enriched regulatory T cell population, and down-regulated the expression of various contact molecules in T cells. Taken together, our results suggest that NaB modifies encephalitogenic T cells at multiple steps and that NaB may have therapeutic importance in multiple sclerosis.

Alternative pathway therapy for urea cycle disorders: twenty years later.

Alternative pathway therapy is currently an accepted treatment approach for inborn errors of the urea cycle. This involves the long-term use of oral sodium phenylbutyrate, arginine supplements, or both, depending on the specific enzyme deficiency, and treatment of acute hyperammonemic crises with intravenous sodium benzoate/sodium phenylacetate plus arginine. A review of 20 years of experience with this approach illustrates the strengths and limitations of this treatment. It has clearly decreased the mortality and morbidity from these disorders, but they remain unacceptably high. The medications are generally well tolerated, but severe accidental overdosage has been reported because of the infrequent use of the medication. There is also a difference in their metabolism between newborns and older children that must be addressed in determining dosage. To avoid these complications it is recommended that drug levels in blood be monitored routinely and that very specific treatment protocols and oversight be followed to avoid overdoses. Finally, it must be acknowledged that alternative pathway therapy has limited effectiveness in preventing hyperammonemia and must be combined with effective dietary management. Therefore in children with neonatal-onset disease or in those with very poor metabolic control, liver transplantation should be considered. There should also be the continued search for innovative therapies that may offer a more permanent and complete correction, such as gene therapy.