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Kidney International May 1978The understanding of the formation of urinary stones centers around three main mechanisms: the urinary concentration of stone-forming ions, the role of promoters, and... (Review)
Review
The understanding of the formation of urinary stones centers around three main mechanisms: the urinary concentration of stone-forming ions, the role of promoters, and the role of inhibitors of crystal formation and crystal aggregation. With respect to the promoting activity, lately emphasis has shifted from the role of the organic matrix to that of one salt inducing by epitaxy the precipitation of another salt. Among the inhibitors, it has become necessary to distinguish between those affecting crystal formation and those affecting crystal aggregation. For measuring the inhibitory activity, the various techniques and their relevance have been reviewed. It has been found that the main inhibitors for calcium phosphate and calcium oxalate precipitation are citrate, pyrophosphate, and perhaps magnesium. Those for calcium phosphate and calcium oxalate aggregation are glycosaminoglycans, pyrophosphate, and citrate. Among the synthetic inhibitors, the diphosphonates are the most powerful for both processes. The role and the therapeutic implications of these various concepts have been discussed.
Topics: Animals; Calcium; Calcium Phosphates; Crystallization; Diphosphonates; Humans; Oxalates; Proteinuria; Urinary Calculi
PubMed: 351264
DOI: 10.1038/ki.1978.54 -
The Onderstepoort Journal of Veterinary... May 2019Shrubs represent the most affordable and accessible form of feed that livestock can rely on to acquire both essential and non-essential elements of life. In addition to...
Shrubs represent the most affordable and accessible form of feed that livestock can rely on to acquire both essential and non-essential elements of life. In addition to their inherent toxins, they contain endogenous substances commonly referred to as 'antinutritive factors' (ANFs) that often interfere with the utilisation of nutrients. Their abundance may lead to severe clinical trauma. Hence, the objective of the study was to investigate the effects of different extraction techniques on Nerium oleander L. and animal feeds as well as to quantify oxalates. Organic (hexane, acetone and methanol) sequential and aqueous (infusion and decoction) extractions were explored. Qualitative and quantitative analyses were conducted to determine the presence of various phytochemicals and oxalate contents as putative ANFs, respectively. The results showed higher extraction yields of 22.6% and 43.1% in the decoction and infusion of N. oleander, respectively. The quantification methods were validated for linearity, accuracy and precision. Oxalate contents of 6.76 ± 0.245 (0.65%) mg/g and 5.74 ± 0.236 mg/g dry weight (0.55%) were obtained in N. oleander and feeds, respectively. This difference was statistically significant with p < 0.05. Percentage recoveries of 98.5 (percent relative standard deviation [% RSD] = 2.3), 85.7 (% RSD = 1.03) and 80.3 (% RSD = 1.22) at 76%, 95% and 112% fortifications were obtained, respectively. Relative standard deviation for precision was 0.99% and 1.13% at 0.33 mg and 0.39 mg fortifications, respectively, while reproducibility showed 2.21% RSD. Therefore, these methods can be used to provide a valuable basis for qualitative determination of ANFs, particularly in shrub foliage.
Topics: Animal Feed; Animal Husbandry; Animals; Chromatography, High Pressure Liquid; Livestock; Nerium; Oxalates; Plant Extracts; Plant Leaves; Reproducibility of Results; South Africa
PubMed: 31170782
DOI: 10.4102/ojvr.v86i1.1611 -
Revue Medicale de Liege Jul 2022Primary hyperoxaluria type 1 is a rare autosomal recessive disorder leading to oxalate overproduction by deficiency in the liver-specific enzyme alanine-glyoxylate...
Primary hyperoxaluria type 1 is a rare autosomal recessive disorder leading to oxalate overproduction by deficiency in the liver-specific enzyme alanine-glyoxylate transaminase (AGT). Oxalate is a poorly soluble molecule that binds calcium and deposits in the entire organism leading to oxalosis. Its elimination is mainly carried out by kidneys. Hence the first manifestations are frequently of urinary concern and whitout any early care, progression of the disease to end-stage renal failure cannot be avoided. The only etiological treatment has long been combined liver-kidney transplantation because it restaures enzymatic function and replaces pathological kidneys. However, for a few years now, numerous studies are carried out on this subject and promising results have already been published with a new drug, lumasiran. From a clinical case, we describe the different options for the therapeutic management of primary hyperoxaluria type 1.
Topics: Humans; Hyperoxaluria, Primary; Nephrocalcinosis; Oxalates; RNA, Small Interfering
PubMed: 35924494
DOI: No ID Found -
Nutrients Dec 2020Kidney stone disease is increasing in prevalence, and the most common stone composition is calcium oxalate. Dietary oxalate intake and endogenous production of oxalate... (Review)
Review
Kidney stone disease is increasing in prevalence, and the most common stone composition is calcium oxalate. Dietary oxalate intake and endogenous production of oxalate are important in the pathophysiology of calcium oxalate stone disease. The impact of dietary oxalate intake on urinary oxalate excretion and kidney stone disease risk has been assessed through large cohort studies as well as smaller studies with dietary control. Net gastrointestinal oxalate absorption influences urinary oxalate excretion. Oxalate-degrading bacteria in the gut microbiome, especially may mitigate stone risk through reducing net oxalate absorption. Ascorbic acid (vitamin C) is the main dietary precursor for endogenous production of oxalate with several other compounds playing a lesser role. Renal handling of oxalate and, potentially, renal synthesis of oxalate may contribute to stone formation. In this review, we discuss dietary oxalate and precursors of oxalate, their pertinent physiology in humans, and what is known about their role in kidney stone disease.
Topics: Bacteria; Calcium Oxalate; Diet; Gastrointestinal Microbiome; Humans; Kidney; Kidney Calculi; Nephrolithiasis; Oxalates; Oxalobacter formigenes; Urolithiasis
PubMed: 33379176
DOI: 10.3390/nu13010062 -
Microbiology and Immunology 2000An oxalate-degrading Enterococcus faecalis was isolated from human stools under anaerobic conditions. The bacteria required a poor nutritional environment and repeated...
An oxalate-degrading Enterococcus faecalis was isolated from human stools under anaerobic conditions. The bacteria required a poor nutritional environment and repeated subculturing to maintain their oxalate-degrading ability. The E. faecalis produced 3 proteins (65, 48, and 40 kDa) that were not produced by non-oxalate-degrading E. faecalis as examined by SDS-PAGE. Antibodies against oxalyl-coenzyme A decarboxylase (65 kDa) and formyl-coenzyme A transferase (48 kDa) obtained from Oxalobacter formigenes (an oxalate-degrading anaerobic bacterium in the human intestine) reacted with 2 of the proteins (65 and 48 kDa) from the E. faecalis as examined by Western blottings. This is the first report on the isolation of oxalate-degrading facultative anaerobic bacteria from humans.
Topics: Adult; Animals; Bacterial Proteins; Colony Count, Microbial; Culture Media; Electrophoresis, Polyacrylamide Gel; Enterococcus faecalis; Feces; Female; Humans; Male; Oxalates; Rabbits
PubMed: 10832966
DOI: 10.1111/j.1348-0421.2000.tb02489.x -
World Journal of Microbiology &... Apr 2024Oxalic acid and oxalates are secondary metabolites secreted to the surrounding environment by fungi, bacteria, and plants. Oxalates are linked to a variety of processes... (Review)
Review
Oxalic acid and oxalates are secondary metabolites secreted to the surrounding environment by fungi, bacteria, and plants. Oxalates are linked to a variety of processes in soil, e.g. nutrient availability, weathering of minerals, or precipitation of metal oxalates. Oxalates are also mentioned among low-molecular weight compounds involved indirectly in the degradation of the lignocellulose complex by fungi, which are considered to be the most effective degraders of wood. The active regulation of the oxalic acid concentration is linked with enzymatic activities; hence, the biochemistry of microbial biosynthesis and degradation of oxalic acid has also been presented. The potential of microorganisms for oxalotrophy and the ability of microbial enzymes to degrade oxalates are important factors that can be used in the prevention of kidney stone, as a diagnostic tool for determination of oxalic acid content, as an antifungal factor against plant pathogenic fungi, or even in efforts to improve the quality of edible plants. The potential role of fungi and their interaction with bacteria in the oxalate-carbonate pathway are regarded as an effective way for the transfer of atmospheric carbon dioxide into calcium carbonate as a carbon reservoir.
Topics: Oxalic Acid; Fungi; Bacteria; Biotechnology; Plants; Oxalates; Lignin
PubMed: 38662173
DOI: 10.1007/s11274-024-03973-5 -
Medical Mycology Journal 2015
Topics: Aspergillosis; Aspergillus fumigatus; Calcium Oxalate; Crystallization; Humans; Lung Diseases, Fungal; Male; Middle Aged; Oxalates; Pneumonectomy
PubMed: 25855022
DOI: 10.3314/mmj.56.J1 -
British Journal of Clinical Pharmacology Jun 2022RNA interference (RNAi) is a natural biological pathway that inhibits gene expression by targeted degradation or translational inhibition of cytoplasmic mRNA by the RNA... (Review)
Review
RNA interference (RNAi) is a natural biological pathway that inhibits gene expression by targeted degradation or translational inhibition of cytoplasmic mRNA by the RNA induced silencing complex. RNAi has long been exploited in laboratory research to study the biological consequences of the reduced expression of a gene of interest. More recently RNAi has been demonstrated as a therapeutic avenue for rare metabolic diseases. This review presents an overview of the cellular RNAi machinery as well as therapeutic RNAi design and delivery. As a clinical example we present primary hyperoxaluria, an ultrarare inherited disease of increased hepatic oxalate production which leads to recurrent calcium oxalate kidney stones. In the most common form of the disease (Type 1), end-stage kidney disease occurs in childhood or young adulthood, often necessitating combined kidney and liver transplantation. In this context we discuss nedosiran (Dicerna Pharmaceuticals, Inc.) and lumasiran (Alnylam Pharmaceuticals), which are both novel RNAi therapies for primary hyperoxaluria that selectively reduce hepatic expression of lactate dehydrogenase and glycolate oxidase respectively, reducing hepatic oxalate production and urinary oxalate levels. Finally, we consider future optimizations advances in RNAi therapies.
Topics: Adult; Female; Humans; Hyperoxaluria, Primary; Male; Oxalates; RNA Interference; RNA, Small Interfering; Young Adult
PubMed: 34022071
DOI: 10.1111/bcp.14925 -
BMC Nephrology Jul 2023The kidney is particularly vulnerable to toxins due to its abundant blood supply, active tubular reabsorption, and medullary interstitial concentration. Currently,... (Review)
Review
BACKGROUND
The kidney is particularly vulnerable to toxins due to its abundant blood supply, active tubular reabsorption, and medullary interstitial concentration. Currently, calcium phosphate-induced and calcium oxalate-induced nephropathies are the most common crystalline nephropathies. Hyperoxaluria may lead to kidney stones and progressive kidney disease due to calcium oxalate deposition leading to oxalate nephropathy. Hyperoxaluria can be primary or secondary. Primary hyperoxaluria is an autosomal recessive disease that usually develops in childhood, whereas secondary hyperoxaluria is observed following excessive oxalate intake or reduced excretion, with no difference in age of onset. Oxalate nephropathy may be overlooked, and the diagnosis is often delayed or missed owning to the physician's inadequate awareness of its etiology and pathogenesis. Herein, we discuss the pathogenesis of hyperoxaluria with two case reports, and our report may be helpful to make appropriate treatment plans in clinical settings in the future.
CASE PRESENTATION
We report two cases of acute kidney injury, which were considered to be due to oxalate nephropathy in the setting of purslane (portulaca oleracea) ingestion. The two patients were elderly and presented with oliguria, nausea, vomiting, and clinical manifestations of acute kidney injury requiring renal replacement therapy. One patient underwent an ultrasound-guided renal biopsy, which showed acute tubulointerstitial injury and partial tubular oxalate deposition. Both patients underwent hemodialysis and were discharged following improvement in creatinine levels.
CONCLUSIONS
Our report illustrates two cases of acute oxalate nephropathy in the setting of high dietary consumption of purslane. If a renal biopsy shows calcium oxalate crystals and acute tubular injury, oxalate nephropathy should be considered and the secondary causes of hyperoxaluria should be eliminated.
Topics: Humans; Aged; Portulaca; Calcium Oxalate; Hyperoxaluria; Oxalates; Acute Kidney Injury; Acute Disease
PubMed: 37443012
DOI: 10.1186/s12882-023-03236-9 -
Urolithiasis Feb 2016Dietary modifications should be considered as a first line approach in the treatment of idiopathic calcium oxalate nephrolithiasis. The amounts of oxalate and calcium... (Review)
Review
Dietary modifications should be considered as a first line approach in the treatment of idiopathic calcium oxalate nephrolithiasis. The amounts of oxalate and calcium consumed in the diet are significant factors in the development of the disease due to their impact on urinary oxalate excretion. There are a number of strategies that can be employed to reduce oxalate excretion. The consumption of oxalate-rich foods should be avoided and calcium intake adjusted to 1000-1200 mg/day. To encourage compliance it should be emphasized to patients that they be vigilant with this diet as a deviation in any meal or snack could potentially result in significant stone growth. The evidence underlying these two modifications is outlined and other strategies to reduce urinary oxalate excretion are reviewed.
Topics: Calcium Oxalate; Calcium, Dietary; Humans; Intestinal Absorption; Kidney Calculi; Oxalates; Oxalobacter formigenes
PubMed: 26614109
DOI: 10.1007/s00240-015-0839-4