Oxalate secretion was achieved in Pseudomonas fluorescens ATCC 13525 by incorporation of genes encoding Aspergillus niger oxaloacetate acetyl hydrolase (oah), Fomitopsis plaustris oxalate transporter (FpOAR) and Vitreoscilla hemoglobin (vgb) in various combinations. Pf (pKCN2) transformant containing oah alone accumulated 19 mM oxalic acid intracellularly but secreted 1.2 mM. However, in the pr...

Acid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypothesized that the highly insoluble biomineral Ca oxalate might represent an additional soil Ca pool that ...

We have measured unidirectional transmural fluxes of oxalate and neutral sugars across rat ascending colon in vitro, under short-circuit conditions, to characterize permeability barriers selective for size and charge. Ionic oxalate appears to be transported preferentially to sodium oxalate. Mucosal addition of taurocholate (1 mM), deoxycholate (1 mM), or ricinoleate (1 mM) increased bidirection...

For this direct colorimetry of urinary oxalate, commercially available oxalate oxidase (EC 1.2.3.4) is used. The urine is first diluted, to diminish the effect of interfering substances. Analytical recovery of oxalate from urines with five different oxalate concentrations (0.4 to 2.0 mmol/L) ranged from 92 to 109% (mean 99%). The within-day and between-day precision (CV) of the method for a wid...

Mutations in the alanine-glyoxylate amino transferase gene (AGXT) are responsible for primary hyperoxaluria type I, a rare disease characterized by excessive hepatic oxalate production that leads to renal failure. We generated a null mutant mouse by targeted mutagenesis of the homologous gene, Agxt, in embryonic stem cells. Mutant mice developed normally, and they exhibited hyperoxaluria and cr...

The inhibitory effect of two kinds of Kampou medicine, Chorei-to and Gorei-san, on calcium oxalate crystallization in human urine, was examined. Chorei-to or Gorei-san was administered to 15 healthy male volunteers for three consecutive days under normal dietary conditions and 24-hour urine samples were collected before and after the administration. Urinary parameters including calcium, phospho...

The production of small quantities of Fe(II) during the initial phase of microbial Fe(III) reduction greatly increased the amount of Fe(III) that could be extracted from freshwater sediments with oxalate. This finding and other evidence suggest that the oxalate-extractable Fe(III) that is unavailable for microbial reduction in anoxic sediments is not in the form of mixed Fe(III)-Fe(II) forms, a...

BACKGROUND: Urinary oxalate and citrate are the keyfactors in caox urolithiasis of cats and Gamma GlutamylTransferase is a good test for assessment of kidney damage.Favorable effects of Cynodon dactylon on calcium oxalate stoneformation have recently been proved in rats. OBJECTIVES: Thepresent study was designed to investigate the alteration ofurinary oxalate, citrate, and GGT after administrat...

BACKGROUND The contribution of ascorbate to urinary oxalate is controversial. The present study aimed to determine whether urinary oxalate and pH may be affected by vitamin C supplementation in calcium stone-forming patients. METHODS Forty-seven adult calcium stone-forming patients received either 1 g (N=23) or 2 g (N=24) of vitamin C supplement for 3 days and 20 healthy subjects received 1 g...