Metabolic changes in the urine of andrographolide sodium bisulfite-treated rats.

In recent years, andrographolide sodium bisulfite (ASB) has been reported to cause acute renal failure frequently in clinical practice. We hypothesized that changes in metabolic profile could have occurred after administration of ASB. To investigate the metabolic changes caused by ASB-induced nephrotoxicity, metabonomics method was utilized to depict the urine metabolic characteristics and find the specific urine biomarkers associated with ASB-induced nephrotoxicity. Sprague-Dawley rats were randomly assigned into three experimental groups. They received a single daily injection of vehicle (0.9% sodium chloride solution) or ASB at a dose of 100 or 600 mg kg(-1) day(-1) for 7 days. Twelve-hour urine was collected after the last administration. The routine urinalysis was measured by a urine automatic analyzer while urinary metabolites were evaluated using gas chromatography/mass spectrometry. The acquired data were processed by multivariate principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal PLS-DA. After 7-day administration of ASB, the positive urine samples in protein, occult blood, and ketones were increased, presenting dose dependence. The PCA and PLS-DA models were capable of distinguishing the difference between ASB-treated group and control. Biomarkers such as 1,5-anhydroglucitol, d-erythro-sphingosine, and 2-ketoadipate were identified as the most influential factors in ASB-induced nephrotoxicity.

Sulfite oxidase deficiency in a newborn.

Isolated sulfite oxidase deficiency is a rare, autosomal recessive disease with a very poor prognosis. This condition usually presents in the neonatal period and is mainly characterized by neurological abnormalities, including refractory seizures, abnormal muscle tone, abnormal movements, and marked developmental delay. The differentiation from hypoxic-ischemic encephalopathy is difficult based on clinical findings alone. We present a neonatal case

Urinary sulphate excretion and progression of diabetic nephropathy in Type 1 diabetes.

AIMS: Hydrogen sulphide levels are reduced in many disease states, including diabetes and end-stage renal disease. We aimed to determine whether urinary sulphate excretion, as a proxy for hydrogen sulphide, was associated with progression of diabetic nephropathy. METHODS: We conducted a post-hoc study of a prospective, randomized, controlled trial on the effect of a low vs. normal protein diet for 4 years, on decline of renal function in patients with Type 1 diabetes and diabetic nephropathy. We excluded patients with less than three measurements of glomerular filtration rate assessed by (51)Cr-EDTA plasma clearance (GFR) and less than 1 year of follow-up (n = 10), leaving 72 patients eligible for analyses. We studied both association of rate of decline in GFR and association of the combined endpoint of end-stage renal disease and death with baseline 24-h urinary sulphate excretion. RESULTS: Sulphate excretion was significantly associated with the slope of GFR (rs = -0.28, P = 0.02). In a multivariate regression model, sulphate excretion was a significant determinant of decline in GFR, independent of age, gender, blood pressure, HbA1c , smoking, albuminuria, baseline GFR and diet group (P < 0.01). In addition, adjusted r(2) increased from 5% in a model with the aforementioned risk factors to 22% when sulphate excretion was included in the model. Cox regression revealed a hazard ratio of 0.34 (95% CI 0.13-0.88, P = 0.026) for each natural log unit increase in urinary sulphate excretion. CONCLUSION: High urinary sulphate excretion was significantly associated with slower decline in (51)Cr-EDTA-assessed GFR in diabetic nephropathy, independent of known progression promoters.

Quantification of andrographolide sodium bisulphite in urine after intravenous injection to rats by LC-MS/MS.

A liquid chromatography-tandem mass spectrometry method for the determination of andrographolide sodium bisulphite (ASB) in rat urine was established and validated. To our knowledge, the analytical method is the first developed assay for the determination of ASB in urine samples. Dehydroandrographolide (DAG) was used as an internal standard. ASB and DAG were separated on a C(18) column and detected at negative ion mode using the mass transitions of m/z 413.2→287.2 and m/z 331.2→303.3, respectively. Good linearity was obtained over the range of 50-5000 ng/mL and the correlation coefficient was better than 0.99. The intra- and inter-day accuracy at all levels fell in the ranges of 85.8-101.4% and 87.9-97.5%, and the intra- and inter-day precision (RSD) were in the ranges of 4.3-11.2% and 8.4-13.3%, respectively. The recovery ranged from 96.1% to 98.3% and the matrix effects from 96.2% to 98.1%. Good stability was found under tested conditions. The method was successfully applied to a urinary excretion study of ASB in rats following intravenous administration of 80 mg/kg ASB.

Clinical and imaging observations in isolated sulfite oxidase deficiency.

Isolated sulfite oxidase deficiency is a rare neurometabolic disorder that closely mimics hypoxic ischemic encephalopathy both clinically and radiologically. Phenotypic and imaging observations in 2 children (aged 14 months and 8 years) with this disease are described. Both had profound mental retardation, microcephaly, spastic quadriparesis, and uncontrolled seizures from the neonatal period. Diagnosis was established by demonstrating the presence of sulfites in urine and genetic analysis. Magnetic resonance imaging of the brain revealed severe cystic leukomalacia, cortical atrophy with ulegyric pattern, and cerebellar hypoplasia that progressed over time in both the patients. Early diagnosis of this devastating disorder will provide an opportunity for genetic counseling and prenatal testing.

Pyridoxal 5'-phosphate in cerebrospinal fluid; factors affecting concentration.

Analysis of pyridoxal 5'-phosphate (PLP) concentration in 256 cerebrospinal fluid (CSF) samples from patients with neurological symptoms showed that the variance is greater than indicated by previous studies. The age-related lower reference limit has been revised to detect inborn errors of metabolism that lead to PLP depletion without a high false positive rate: < 30 days, 26 nmol/L; 30 days to 12 months, 14 nmol/L; 1-2 years, 11 nmol/L; > 3 years, 10 nmol/L. Inborn errors leading to PLP concentrations below these values include pyridoxine-dependent epilepsy due to antiquitin deficiency, and molybdenum cofactor deficiency that leads to the accumulation of sulfite, a nucleophile capable of reacting with PLP. Low PLP levels were also seen in a group of children with transiently elevated urinary excretion of sulfite and/or sulfocysteine, suggesting that there may be other situations in which sulfite accumulates and inactivates PLP. There was no evidence that seizures or the anticonvulsant drugs prescribed for patients in this study led to significant lowering of CSF PLP. A small proportion of patients receiving L-dopa therapy were found to have a CSF PLP concentration below the appropriate reference range. This may have implications for monitoring and treatment. A positive correlation was seen between the CSF PLP and 5-methyl-tetrahydrofolate (5-MTHF) and tetrahydrobiopterin (BH(4)) concentrations. All are susceptible to attack by nucleophiles and oxygen-derived free-radicals, and CSF has relatively low concentrations of other molecules that can react with these compounds. Further studies of CSF PLP levels in a wide range of neurological diseases might lead to improved understanding of pathogenesis and possibilities for treatment.

Molybdenum cofactor deficiency in a Malaysian child.

Molybdenum cofactor deficiency is a rare autosomal recessive disorder with devastating neurological manifestations, characterised by neonatal-onset encephalopathy mimicking hypoxic-ischaemic insult, intractable seizure, and feeding and respiratory difficulties. It is often fatal in the early life. We report an affected 8-year-old boy, who presented with severe neurological manifestations since birth, but without clinically-significant seizure. Molybdenum cofactor deficiency must be included in the differential diagnosis of patients presenting with unexplained encephalopathy in the newborn period, and whose neuroimaging findings are consistent with hypoxic ischaemic encephalopathy. The classic laboratory hallmark of this disorder is low serum uric acid, positive urine sulphite dipstick test, and elevated urinary S-sulphocysteine, hypoxanthine and xanthine.

Magnetic resonance imaging and magnetic resonance spectroscopy in isolated sulfite oxidase deficiency.

Isolated sulfite oxidase deficiency is a rare genetic neurometabolic disease. The first symptoms of this disorder (similar to symptoms of ischemic events) may lead to misdiagnosis and to subsequent birth of affected children in these families. This study characterizes the magnetic resonance (MR) imaging and (for the first time, to our knowledge) the MR spectroscopy features of isolated sulfite oxidase deficiency to provide a means for early and correct diagnosis. Three patients with isolated sulfite oxidase deficiency are studied who manifested intractable seizures and severe hypotonia in the immediate postnatal period with an unknown diagnosis, despite extensive workup. MR imaging and proton MR spectroscopy examinations were performed early in the neonatal period in 2 infants and after 5 months in the third infant. The prominent MR features were early cystic white matter damage, accompanied by profound cerebral atrophy in the third infant. Compared with hypoxic-ischemic disorder, MR findings in isolated sulfite oxidase deficiency demonstrate a more severe condition, without subsequent recovery. The MR spectroscopy studies indicate early onset of energetic and metabolic imbalance. Urine stick findings demonstrated high sulfite levels in 2 patients, and the final diagnosis was subsequently made based on molecular, biochemical, and genetic findings. Magnetic resonance imaging and MR spectroscopy measurements may help differentiate isolated sulfite oxidase deficiency from hypoxic-ischemic condition in patients in whom this diagnosis is not clinically suspected and may lead to further genetic antenatal inquiry that might prevent the birth of other infants affected with this severe and incurable congenital disease.

Molybdenum cofactor-deficient mice resemble the phenotype of human patients.

Human molybdenum cofactor deficiency is a rare and devastating autosomal-recessive disease for which no therapy is known. The absence of active sulfite oxidase-a molybdenum cofactor-dependent enzyme-results in neonatal seizures and early childhood death. Most patients harbor mutations in the MOCS1 gene, whose murine homolog was disrupted by homologous recombination with a targeting vector. As in humans, heterozygous mice display no symptoms, but homozygous animals die between days 1 and 11 after birth. Biochemical analyis of these animals shows that molydopterin and active cofactor are undetectable. They do not possess any sulfite oxidase or xanthine dehydrogenase activity. No organ abnormalities were observed and the synaptic localization of inhibitory receptors, which was found to be disturbed in molybdenum cofactor deficient-mice with a Gephyrin mutation, appears normal. MOCS1(-/-) mice could be a suitable animal model for biochemical and/or genetic therapy approaches.

Molybdenum cofactor deficiency: report of three cases presenting as hypoxic-ischemic encephalopathy.

We report three infants with the diagnosis of molybdenum cofactor deficiency. The key findings leading to diagnosis were neonatal seizures unresponsive to treatment, craniofacial dysmorphic features, hyperexcitability, low blood uric acid levels, and neuroimaging findings. The parents were consanguineous in two of these patients. The diagnosis was established by the presence of low blood uric acid levels, positive urine sulfite reaction, quantitative aminoacid analysis, and high-voltage electrophoresis of the urine sample showing a typical increase of S-sulfo-L-cysteine. Skin fibroblast cultures confirmed the diagnosis. Magnetic resonance imaging findings were suggestive of encephalomalacia with cystic changes due to hypoxic-ischemic encephalopathy. We conclude that molybdenum cofactor deficiency must be included in the differential diagnosis of patients presenting with intractable seizures in the newborn period who have computed tomography and magnetic resonance imaging findings reminiscent of those of hypoxic-ischemic encephalopathy, and the urine sulfite dipstick test can be a part of the evaluation of these infants in neonatal intensive care units.

Infantile isolated sulphite oxidase deficiency: report of a case with negative sulphite test and normal sulphate excretion.

We present the clinical and biochemical data of a patient with infantile isolated sulphite oxidase deficiency with late onset of symptoms. A comparison of the biochemical parameters is made with the neonatal type of this disease and with the data of described patients with the combined defect of sulphite oxidase and xanthine oxidase, due to molybdenum cofactor deficiency. False-negative sulphite dip stick test as a pitfall in the diagnosis of sulphite oxidase deficiency is discussed.

Combined xanthine and sulphite oxidase defect due to a deficiency of molybdenum cofactor.

Increased urinary excretion of xanthine, hypoxanthine, sulphite, thiosulphate and decreased serum uric acid were observed in an infant with profound failure to thrive. Other clinical findings included refractory seizures, spastic quadriplegia and profound psychomotor retardation. The patient died at 20 months of age. There were no detectable activities for xanthine oxidase and sulphite oxidase in the postmortem liver. Urothione, which is the metabolic excretory product of the molybdenum cofactor for molybdoenzymes was not present in the urine. A deficiency of the molybdenum cofactor which is common to both xanthine and sulphite oxidase is presumed to be the metabolic defect responsible for the absent activities of both enzymes.