RESUMEN
Chronic kidney disease (CKD) is a worldwide public health issue affecting 14% of the general population. However, research focusing on CKD mechanisms/treatment is limited because of a lack of animal models recapitulating the disease physiopathology, including its complications. We analyzed the effects of a three-week diet rich in sodium oxalate (OXA diet) on rats and showed that, compared to controls, rats developed a stable CKD with a 60% reduction in glomerular filtration rate, elevated blood urea levels and proteinuria. Histological analyses revealed massive cortical disorganization, tubular atrophy and fibrosis. Males and females were sensitive to the OXA diet, but decreasing the diet period to one week led to GFR significance but not stable diminution. Rats treated with the OXA diet also displayed classical CKD complications such as elevated blood pressure and reduced hematocrit. Functional cardiac analyses revealed that the OXA diet triggered significant cardiac dysfunction. Altogether, our results showed the feasibility of using a convenient and non-invasive strategy to induce CKD and its classical systemic complications in rats. This model, which avoids kidney mass loss or acute toxicity, has strong potential for research into CKD mechanisms and novel therapies, which could protect and postpone the use of dialysis or transplantation.
Asunto(s)
Dieta/efectos adversos , Cardiopatías/etiología , Hiperoxaluria/etiología , Ácido Oxálico/toxicidad , Insuficiencia Renal Crónica/etiología , Animales , Presión Sanguínea , Femenino , Tasa de Filtración Glomerular , Frecuencia Cardíaca , Hematócrito , Masculino , Ácido Oxálico/administración & dosificación , Ácido Oxálico/farmacocinética , Ratas , Ratas WistarRESUMEN
MicroRNAs in biofluids are potential biomarkers for detecting kidney and other organ injuries. We profiled microRNAs in urine samples from patients with Russell's viper envenoming or acute self-poisoning following paraquat, glyphosate, or oxalic acid [with and without acute kidney injury (AKI)] and on healthy controls. Discovery analysis profiled for 754 microRNAs using TaqMan OpenArray qPCR with three patients per group (12 samples in each toxic agent). From these, 53 microRNAs were selected and validated in a larger cohort of patients (Russell's viper envenoming = 53, paraquat = 51, glyphosate = 51, oxalic acid = 40) and 27 healthy controls. Urinary microRNAs had significantly higher expression in patients poisoned/envenomed by different nephrotoxic agents in both discovery and validation cohorts. Seven microRNAs discriminated severe AKI patients from no AKI for all four nephrotoxic agents. Four microRNAs (miR-30a-3p, miR-30a-5p, miR-92a, and miR-204) had > 17 fold change (p < 0.0001) and receiver operator characteristics area-under-curve (ROC-AUC) > 0.72. Pathway analysis of target mRNAs of these differentially expressed microRNAs showed association with the regulation of different nephrotoxic signaling pathways. In conclusion, human urinary microRNAs could identify toxic AKI early after acute injury. These urinary microRNAs have potential clinical application as early non-invasive diagnostic AKI biomarkers.
Asunto(s)
Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/orina , Biomarcadores/orina , MicroARNs/orina , Lesión Renal Aguda/genética , Animales , Glicina/análogos & derivados , Glicina/envenenamiento , Humanos , Ácido Oxálico/toxicidad , Paraquat/envenenamiento , Reproducibilidad de los Resultados , Daboia , Venenos de Víboras/envenenamiento , GlifosatoRESUMEN
Oxalic acid-induced nephrotoxicity and acute kidney injury result from formation of calcium oxalate crystals. Oxalic acid-induced acute kidney injury is a significant problem in many parts of the world. Circulating biomarkers that can accurately and reproducibly detect acute kidney injury are highly desirable. We used a high sensitivity discovery platform to identify signature microRNAs to distinguish healthy individuals never exposed to oxalic acid (n = 4) from those who were exposed to oxalic acid but had no injury (NOAKI; n = 4), moderate injury (AKIN2; n = 4) or severe injury (AKIN3; n = 4). Longitudinal analyses identified 4-8 h post-ingestion as the best time to detect AKIN2/3. We validated a signature of 53 microRNAs identified in the discovery, in a second cohort of individuals exposed to oxalic acid (NOAKI = 11, AKIN2 = 8 and AKIN3 = 18) and healthy controls (n = 19). Thirteen microRNAs were significantly downregulated in acute kidney injury patients compared to NOAKI within 8-h post-ingestion. Five microRNAs (miR-20a, miR-92a, miR-93, miR-195, miR-451) had a highly significant correlation with normalized urinary albumin, serum creatinine at 24 h and creatinine clearance. Logistic regression of these microRNAs had AUC-ROC of 0.85 predicting AKIN2/3 and discriminated patients from healthy controls (AUC-ROC = 0.93). mRNA targets of these microRNAs identified oxidative stress pathways of nephrotoxicity in proximal tubule and glomeruli nephrotoxicity. In conclusion, the downregulation of multiple circulating microRNAs in patients correlated with the severity of oxalic acid-induced acute kidney injury. A set of microRNAs (miR-20a, miR-92a, miR-93, miR-195, miR-451) could be promising biomarkers for early detection of oxalic acid-induced acute kidney injury.
Asunto(s)
Lesión Renal Aguda/inducido químicamente , Ácido Oxálico/toxicidad , Adulto , Biomarcadores/metabolismo , Estudios de Casos y Controles , MicroARN Circulante , Estudios de Cohortes , Creatinina , Regulación hacia Abajo , Femenino , Humanos , Riñón , Túbulos Renales Proximales , Masculino , MicroARNs , Persona de Mediana EdadRESUMEN
Nowadays, Varroa destructor is considered as a serious pest of honeybees (Apis mellifera) and its resistance to acaricides has been reported in Europe since the early 1990s. That is why new methods of treatment for Varroa mites are still in focus of many scientists. In our study, we determined the lethal concentration LC50 (72 h) of 2.425% oxalic acid solution following single spray exposure of honeybee larvae under laboratory conditions (Guideline OECD 237 2013). Potential sublethal effects of oxalic acid were monitored through the determination of the activity of antioxidant enzymes. Activation of primary antioxidant enzymes was observed at 1.75% of oxalic acid; 3.5% of oxalic acid brought on a statistically significant increase of glutathione S-transferase activity. This change was accompanied by an increase in thiobarbituric acid reactive substances, products of lipid peroxidation. Our results indicate that oxalic acid may be harmful to bee brood when present during application.
Asunto(s)
Acaricidas/toxicidad , Antioxidantes/metabolismo , Abejas/efectos de los fármacos , Larva/efectos de los fármacos , Ácido Oxálico/toxicidad , Animales , Abejas/enzimología , Abejas/crecimiento & desarrollo , Dosificación Letal Mediana , VarroidaeRESUMEN
Oxalic acid is a naturally occurring metabolite in plants and a common constituent of all plant-derived human diets. Oxalic acid has diverse unrelated roles in plant metabolism, including pH regulation in association with nitrogen metabolism, metal ion homeostasis and calcium storage. In plants, oxalic acid is also a pathogenesis factor and is secreted by various fungi during host infection. Unlike those of plants, fungi and bacteria, the human genome does not contain any oxalate-degrading genes, and therefore, the consumption of large amounts of plant-derived oxalate is considered detrimental to human health. In this review, we discuss recent biotechnological approaches that have been used to reduce the oxalate content of plant tissues.
Asunto(s)
Productos Agrícolas/metabolismo , Ácido Oxálico/metabolismo , Fitomejoramiento/métodos , Proteínas de Plantas/metabolismo , Biotecnología/métodos , Carboxiliasas/genética , Carboxiliasas/metabolismo , Productos Agrícolas/genética , Enzimas/genética , Enzimas/metabolismo , Calidad de los Alimentos , Humanos , Ácido Oxálico/toxicidad , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas GenéticamenteRESUMEN
BACKGROUND: Urolithiasis is a significant healthcare issue but the pathophysiology of stone disease remains poorly understood. Drosophila Malpighian tubules were known to share similar physiological function to human renal tubules. We have used Drosophila as a genetic model to study the transcriptional response to stone formation secondary to dietary manipulation. METHODS: Wild-type male flies were raised on standard medium supplemented with lithogenic agents: control, sodium oxalate (NaOx) and ethylene glycol (EG). At 2 weeks, Malpighian tubules were dissected under polarized microscope to visualize crystals. The parallel group was dissected for RNA extraction and subsequent next-generation RNA sequencing. RESULTS: Crystal formation was visualized in 20%(±2.2) of flies on control diet, 73%(±3.6) on NaOx diet and 84%(±2.2) on EG diet. Differentially expressed genes were identified in flies fed with NaOx and EG diet comparing with the control group. Fifty-eight genes were differentially expressed (FDR <0.05, p < 0.05) in NaOx diet and 20 genes in EG diet. The molecular function of differentially expressed genes were assessed. Among these, Nervana 3, Eaat1 (Excitatory amino acid transporter 1), CG7912, CG5404, CG3036 worked as ion transmembrane transporters, which were possibly involved in stone pathogenesis. CONCLUSIONS: We have shown that by dietary modification, stone formation can be manipulated and visualized in Drosophila Malpighian tubules. This genetic model could be potentially used to identify the candidate genes that influence stone risk hence providing more insight to the pathogenesis of human stone disease.
Asunto(s)
Dieta/efectos adversos , Túbulos de Malpighi/patología , Modelos Genéticos , Nefrolitiasis/genética , Nefrolitiasis/patología , Transcripción Genética/genética , Animales , Dieta/métodos , Drosophila , Masculino , Túbulos de Malpighi/efectos de los fármacos , Nefrolitiasis/inducido químicamente , Ácido Oxálico/toxicidadRESUMEN
Oxalic acid (OA) is an important pathogenic factor during early Sclerotinia sclerotiorum-host interaction and might work by reducing hydrogen peroxide production (H2 O2 ). In the present investigation, oxalic acid-induced cell death in pea was studied. Pea plants treated with biocontrol agents (BCAs) viz., Pseudomonas aeruginosa PJHU15, Bacillus subtilis BHHU100, and Trichoderma harzianum TNHU27 either singly and/or in consortium acted on S. sclerotiorum indirectly by enabling plants to inhibit the OA-mediated suppression of oxidative burst via induction of H2 O2 . Our results showed that BCA treated plants upon treatment with culture filtrate of the pathogen, conferred the resistance via. significantly decreasing relative cell death of pea against S. sclerotiorum compared to control plants without BCA treatment but treated with the culture filtrate of the pathogen. The results obtained from the present study indicate that the microbes especially in consortia play significant role in protection against S. sclerotiorum by modulating oxidative burst and partially enhancing tolerance by increasing the H2 O2 generation, which is otherwise suppressed by OA produced by the pathogen.
Asunto(s)
Ascomicetos/crecimiento & desarrollo , Bacillus/crecimiento & desarrollo , Muerte Celular/efectos de los fármacos , Ácido Oxálico/toxicidad , Pisum sativum/fisiología , Pseudomonas aeruginosa/crecimiento & desarrollo , Trichoderma/crecimiento & desarrollo , Antibiosis , Ascomicetos/metabolismo , Interacciones Huésped-Patógeno , Peróxido de Hidrógeno/metabolismo , Ácido Oxálico/metabolismo , Pisum sativum/efectos de los fármacos , Pisum sativum/inmunología , Pisum sativum/microbiología , Estallido RespiratorioRESUMEN
BACKGROUND: Urinary macromolecules contribute to promoting or inhibiting crystal retention in renal tissue and stone formation. Osteopontin (OPN) and Tamm-Horsfall protein (THP) are the most important proteins involved in this process. Although these two proteins were discovered a long time ago, their role in setting kidney stone formation has not yet been fully investigated. We conducted a study to explore the role of OPN and THP in canine renal oxalosis. Ten dogs were carefully examined prior to the study. Six dogs were assigned to the treatment group and were injected intravenously with 0.5 M potassium oxalate (KOx). The other four dogs were assigned to a control group and were injected intravenously with 0.9% NaCl three times a day (tid) for 7 consecutive days. Then kidneys were harvested for pathological, immunohistochemical examination and OPN and THP mRNA expression levels were quantified by quantitative real-time PCR. RESULTS: Calcium oxalate crystals deposition was observed in both renal cortex and medulla. Immunohistochemistry examination revealed increased tissue expression of OPN in the renal tissue while THP was significantly decreased. OPN mRNA expression level significantly increased in treated dogs compared to that in the controls, while THP mRNA level significantly decreased. CONCLUSION: Together, these results suggest that THP and OPN are both involved in the pathogenesis and response to oxalate exposure.
Asunto(s)
Perros/metabolismo , Riñón/efectos de los fármacos , Osteopontina/metabolismo , Ácido Oxálico/toxicidad , ARN Mensajero/metabolismo , Uromodulina/metabolismo , Animales , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Inmunohistoquímica/veterinaria , Riñón/fisiología , Masculino , Osteopontina/genética , ARN Mensajero/genética , Uromodulina/genéticaRESUMEN
The role of inflammation in oxalate-induced nephrolithiasis is debated. Our gene expression study indicated an increase in interleukin-2 receptor ß (IL-2Rß) mRNA in response to oxalate (Koul S, Khandrika L, Meacham RB, Koul HK. PLoS ONE 7: e43886, 2012). Herein, we evaluated IL-2Rß expression and its downstream signaling pathway in HK-2 cells in an effort to understand the mechanisms of oxalate nephrotoxicity. HK-2 cells were exposed to oxalate for various time points in the presence or absence of SB203580, a specific p38 MAPK inhibitor. Gene expression data were analyzed by Ingenuity Pathway Analysis software. mRNA expression was quantitated via real-time PCR, and changes in protein expression/kinase activation were analyzed by Western blotting. Exposure of HK-2 cells to oxalate resulted in increased transcription of IL-2Rß mRNA and increased protein levels. Oxalate treatment also activated the IL-2Rß signaling pathway (JAK1/STAT5 phosphorylation). Moreover, the increase in IL-2Rß protein was dependent upon p38 MAPK activity. These results suggest that oxalate-induced activation of the IL-2Rß pathway may lead to a plethora of cellular changes, the most common of which is the induction of inflammation. These results suggest a central role for the p38 MAPK pathway in mediating the effects of oxalate in renal cells, and additional studies may provide the key to unlocking novel biochemical targets in stone disease.
Asunto(s)
Células Epiteliales/efectos de los fármacos , Subunidad beta del Receptor de Interleucina-2/efectos de los fármacos , Riñón/efectos de los fármacos , Ácido Oxálico/toxicidad , Transducción de Señal/efectos de los fármacos , Western Blotting , Línea Celular , Activación Enzimática , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Células Epiteliales/patología , Perfilación de la Expresión Génica/métodos , Redes Reguladoras de Genes , Humanos , Mediadores de Inflamación/metabolismo , Subunidad beta del Receptor de Interleucina-2/genética , Subunidad beta del Receptor de Interleucina-2/metabolismo , Janus Quinasa 1/metabolismo , Riñón/inmunología , Riñón/metabolismo , Riñón/patología , Nefritis/inducido químicamente , Nefritis/inmunología , Nefritis/metabolismo , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Transcripción STAT5/metabolismo , Factores de Tiempo , Regulación hacia Arriba , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
The purpose of present study was to investigate influence of magnesium (Mg) salts (Mg L-aspartate, Mg chloride) and their combinations with pyridoxine on development of calcium-oxalate nephrolithiasis induced by sodium oxalate (3% diet weight) and celecoxib (100 mg per kg of bodyweight) according to B.C. Jeong et al. (Urol. Res. 2005; 33(6): 453-459). On 14th day of diet urinary oxalate level and crystalluria were significantly increased, creatinine clearance tended to be lower as compared to control group. Mg L-aspartate, Mg chloride and their combinations with pyridoxine, MagneB6 (Mg lactate in combination with pyridoxine) and Mg sulfate were given by intragastric intubation from 15th till 28th days of diet (50 mg Mg per kg body weight). On 28th day urinary oxalate level in rats treated with Mg salts was lower by in average 45%, creatinine clearance was increased by 19%, Ca/Mg ratio decreased by 1.5-2 times in comparison with animals fed with diet alone. Light microscopic examination of kidney sections have revealed decreased inclusion volume fraction of renal calcification in rats treated with Mg salts as to compare with untreated rats receiving sodium oxalate and celecoxib (0.3-1.0% vs. 4%). So, Mg salts prevented development of calcium-oxalate nephrolithiasis in hyperoxaluric rats. Morphological and laboratory tests showed Mg aspartate and magne B6 were more effective Mg-containing substances in comparison with other studied salts.
Asunto(s)
Cálculos Renales/tratamiento farmacológico , Magnesio/uso terapéutico , Animales , Celecoxib , Inhibidores de la Ciclooxigenasa 2/toxicidad , Cálculos Renales/química , Masculino , Oxalatos/orina , Ácido Oxálico/toxicidad , Pirazoles/toxicidad , Piridoxina/uso terapéutico , Ratas , Sulfonamidas/toxicidadRESUMEN
American chestnut (Castanea dentata) was transformed with a wheat oxalate oxidase (oxo) gene in an effort to degrade the oxalic acid (OA) secreted by the fungus Cryphonectria parasitica, thus decreasing its virulence. Expression of OxO was examined under two promoters: a strong constitutive promoter, CaMV 35S, and a predominantly vascular promoter, VspB. Oxo gene transcription was quantified by RT-qPCR. Relative expression of OxO varied approximately 200 fold among events produced with the 35S-OxO. The lowest 35S-OxO event expressed approximately 3,000 fold higher than the highest VspB-OxO event. This was potentially due to the tissue-specific nature of the VspB-controlled expression, the strength of the CaMV 35S constitutive promoter, or position effects. Leaf assays measuring necrotic lesion length were conducted to better understand the relationship between OxO expression level and the blight fungus in planta. A threshold response was observed between the OxO expression level and the C. parasitica lesion length. Five events of the 35S-OxO line showed significantly reduced lesion length compared to the blight-susceptible American chestnut. More importantly, the lesion length in these five events was reduced to the same level as the blight-resistant Chinese chestnut, C. mollissima. This is the first report on enhanced pathogen resistance in transgenic American chestnut.
Asunto(s)
Ascomicetos/química , Resistencia a la Enfermedad/genética , Fagaceae/microbiología , Oxidorreductasas/metabolismo , Enfermedades de las Plantas/microbiología , Plantas Modificadas Genéticamente/microbiología , Triticum/enzimología , Cartilla de ADN/genética , Fagaceae/genética , Técnicas de Transferencia de Gen , Ácido Oxálico/toxicidad , Oxidorreductasas/genética , Hojas de la Planta/microbiología , Plantas Modificadas Genéticamente/genética , Regiones Promotoras Genéticas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Oxalic acid plays major role in the pathogenesis by Sclerotinia sclerotiorum; it lowers the pH of nearby environment and creates the favorable condition for the infection. In this study we examined the degradation of oxalic acid through oxalate oxidase and biocontrol of Sclerotinia sclerotiorum. A survey was conducted to collect the rhizospheric soil samples from Indo-Gangetic Plains of India to isolate the efficient fungal strains able to tolerate oxalic acid. A total of 120 fungal strains were isolated from root adhering soils of different vegetable crops. Out of 120 strains a total of 80 isolates were able to grow at 10 mM of oxalic acid whereas only 15 isolates were grow at 50 mM of oxalic acid concentration. Then we examined the antagonistic activity of the 15 isolates against Sclerotinia sclerotiorum. These strains potentially inhibit the growth of the test pathogen. A total of three potential strains and two standard cultures of fungi were tested for the oxalate oxidase activity. Strains S7 showed the maximum degradation of oxalic acid (23 %) after 60 min of incubation with fungal extract having oxalate oxidase activity. Microscopic observation and ITS (internally transcribed spacers) sequencing categorized the potential fungal strains into the Aspergillus, Fusarium and Trichoderma. Trichoderma sp. are well studied biocontrol agent and interestingly we also found the oxalate oxidase type activity in these strains which further strengthens the potentiality of these biocontrol agents.
Asunto(s)
Antibiosis , Hongos/efectos de los fármacos , Hongos/metabolismo , Ácido Oxálico/metabolismo , Ácido Oxálico/toxicidad , Oxidorreductasas/metabolismo , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Hongos/clasificación , Hongos/aislamiento & purificación , India , Datos de Secuencia Molecular , Control Biológico de Vectores/métodos , Filogenia , Raíces de Plantas/microbiología , Rizosfera , Análisis de Secuencia de ADN , Microbiología del SueloRESUMEN
Oxalate is the most common component of kidney stones and elevated urinary levels induce renal tubular cell toxicity and death which is essential for crystal attachment. Endothelial cells, in some studies have been shown to regulate certain functions of renal proximal tubule cells. The aim of this study was to evaluate the effect of endothelial cells on tubular cell apoptosis in a co-culture system mimicking the in vivo renal physiological settings. The human umbilical vein endothelial cells (HUVEC) and human renal proximal tubule epithelial cells (RPTEC) were exposed to increasing concentrations (0-1.0 mM) of oxalate with or without 10 µM PDTC pretreatment for 24 h. In HUVEC, RPTEC and HUVEC-RPTEC co-cultures, the cell viability was measured using the WST-1 assay and cell death with the TUNEL analysis using the flow cytometry. The treatment of RPTECs with oxalate lead to 8.9-26.2% cell death which was reduced to 0-1.6% with the PDTC pretreatment. The death rate of RPTECs was significantly increased by 15-19% at different oxalate concentrations when co-cultured with HUVECs. In contrast, cell viability was not substantially altered in PDTC pretreated RPTECs that were co-cultured with HUVECs. Apoptosis was the way of cell death as similar rate of apoptosis was observed in cell culture systems. Although cell viability of RPTECs was further reduced when co-cultured with HUVECs, it was restored with the pretreatment of PDTC. This is the first study focusing on the role of endothelial cells on RPTEC apoptosis following hyperoxaluria.
Asunto(s)
Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/fisiología , Túbulos Renales Proximales/efectos de los fármacos , Ácido Oxálico/toxicidad , Pirrolidinas/farmacología , Tiocarbamatos/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cocultivo , Células Epiteliales/fisiología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Túbulos Renales Proximales/patologíaRESUMEN
The use of hydroxyproline (HP) to generate hyperoxaluria in the rat is a problem because it is impossible to separate the effect of oxalate on renal injury from the effects of HP and the large array of metabolic intermediates formed when HP is converted to oxalate. Previously, the Dahl salt-sensitive (SS) and Brown Norway (BN) rat strains were studied to determine genetic control of resistance or susceptibility to HP-induced renal injury and crystal deposition. To develop a better model to induce hyperoxaluria without causing injury from HP metabolites, animals were fed a diet containing various levels of added oxalate (0, 1, 2, 3, or 5%). After 5 weeks rats were killed and the kidneys were removed for microscopic evaluation of tubule changes and crystal deposition. The 3 and 5% oxalate-fed groups had a substantial increase in urine oxalate, about 50 and 140 µmol/g body weight over controls, respectively. Both the SS and BN 3% oxalate-fed animals showed only slightly elevated tubule area and no crystal deposition. However, BN animals fed 5% oxalate had a dramatic increase in their percent tubule areas compared to control BN rats and treated SS rats. Crystal deposition in the kidneys was only observed in the 5% oxalate-fed groups. The BN kidneys demonstrated a threefold higher crystal deposition compared to oxalate-fed SS rats. We conclude that oxalate-supplemented food is a better method of producing hyperoxaluria in the rat than using HP which may introduce metabolic intermediates injurious to the kidney.
Asunto(s)
Hiperoxaluria/inducido químicamente , Animales , Cristalización , Modelos Animales de Enfermedad , Hidroxiprolina/administración & dosificación , Hidroxiprolina/toxicidad , Hiperoxaluria/metabolismo , Hiperoxaluria/patología , Hiperoxaluria/orina , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Masculino , Ácido Oxálico/administración & dosificación , Ácido Oxálico/toxicidad , Ácido Oxálico/orina , Ratas , Ratas Endogámicas BN , Ratas Endogámicas DahlRESUMEN
Numerous studies have investigated using oxalic acid (OA) to control Varroa mites in honey bee colonies. In contrast, techniques for treating package bees with OA have not been investigated. The goal of this study was to develop a protocol for using OA to reduce mite infestation in package bees. We made 97 mini packages of Varroa-infested adult bees. Each package contained 1,613 +/- 18 bees and 92 +/- 3 mites, and represented an experimental unit. We prepared a 2.8% solution of OA by mixing 35 g OA with 1 l of sugar water (sugar:water = 1:1; w:w). Eight treatments were assigned to the packages based on previous laboratory bioassays that characterized the acute contact toxicity of OA to mites and bees. We administered the treatments by spraying the OA solution directly on the bees through the mesh screen cage using a pressurized air brush and quantified mite and bee mortality over a 10-day period. Our results support applying an optimum volume of 3.0 ml of a 2.8% OA solution per 1,000 bees to packages for effective mite control with minimal adult bee mortality. The outcome of our research provides beekeepers and package bee shippers guidance for using OA to reduce mite populations in package bees.
Asunto(s)
Abejas/efectos de los fármacos , Ácaros , Ácido Oxálico/toxicidad , Control de Plagas/métodos , Animales , Abejas/parasitología , Dosificación Letal Mediana , MortalidadRESUMEN
Contents of anti-nutritional components (tannins and oxalic acid) were determined in samples of forest fruits: blueberry, raspberry and wild strawberry harvested in Lublin region from areas considered as potentially not exposed to pollution (Skierbieszów Landscape Park) and potentially polluted areas (Cement Factory Rejowiec S.A.). Study revealed that blueberry and raspberry fruits collected on potentially polluted area were characterized by higher tannins contents than those harvested on potentially not polluted area. Oxalic acid level in studied material indicated its significantly higher concentration in wild strawberry fruits collected both from not exposed and polluted areas as compared to raspberry and blueberry. Tannins and oxalic acid contents in analyzed berries may be accepted as low and safe for human's health.
Asunto(s)
Contaminantes Atmosféricos/análisis , Arándanos Azules (Planta)/química , Contaminación de Alimentos/análisis , Fragaria/química , Ácido Oxálico/análisis , Taninos/análisis , Contaminantes Atmosféricos/toxicidad , Cromatografía Líquida de Alta Presión , Ecosistema , Humanos , Concentración Máxima Admisible , Ácido Oxálico/toxicidad , Polonia , Taninos/toxicidadRESUMEN
The abundance of Hyalomma lusitanicum ticks in open areas of central Spain is the result of many natural and human factors. Control of tick populations by chemical and other means may be necessary until we can determine the key global factors in this important tick population. Despite many attempts to establish ecological control of ticks, there is little data about the activity of organic acids. This article describes tests on the in vitro toxicity of oxalic acid (OA) against wild H. lusitanicum adult ticks. Serial dilutions of OA dihydrate were prepared in distilled water with 1% of Tween 20. The treatment was applied in three replicates of 10-14 tick/dose from 0 to 1.037 mg OA/tick. Doses > 0.311 mg of OA killed all ticks in 24 h. Toxicity of the OA increased over time; therefore, the LD50 decreased from 0.22 mg at 24 h to 0.127 mg at 72 h. The results obtained show the toxicity of OA against adult H. lusitanicum ticks under in vitro conditions. Comparing toxicity in ticks and honey bees, OA seems a relatively safe treatment for nontarget arthropods and a potential alternative for tick population control. However, further research is needed to establish its real effectiveness and applicability under field conditions.
Asunto(s)
Insecticidas/toxicidad , Ixodidae/efectos de los fármacos , Ácido Oxálico/toxicidad , Animales , Animales de Laboratorio , Clima , Relación Dosis-Respuesta a Droga , EspañaRESUMEN
OBJECTIVE: Oxalic acid (OA) is thought to be a uremic toxin that participates in the pathogenesis of uremic syndrome. The objectives of this study were to: (1) evaluate the plasma levels of OA in patients with chronic renal disease with various levels of glomerular filtration rate and after renal transplantation; (2) investigate the salivary secretion of OA and ascorbic acid in healthy subjects and in patients with chronic renal failure (CRF); (3) examine the influence of water and sodium diuresis and furosemide administration on the urinary excretion of OA and ascorbic acid in healthy subjects and in CRF patients without dialysis treatment; and (4) evaluate the influence of renal replacement therapy (RRT) on secondary hyperoxalemia in hemodialysis patients. DESIGN AND SETTING: This study was conducted at the Nephrological Department of P.J. Safárik University. Sixty-one patients with chronic renal disease, 64 CRF patients, 32 continuous ambulatory peritoneal dialysis (CAPD) patients, 15 hemodialysis patients, 21 patients after renal transplantation, and 15 healthy subjects were examined. Maximal water diuresis, diets with low (2 g/day) and high (15 g/day) sodium intake, administration of intravenous furosemide (20 mg), and renal replacement therapy (CAPD, hemodialysis, hemofiltration, and postdilution hemodiafiltration) were utilized in the study. RESULTS: In patients with chronic renal disease and those after renal transplantation, direct relationships between plasma OA and serum creatinine were found (r = 0.904 and 0.9431, respectively, P < .01). Despite a high level of plasma OA in uremic patients (23.1 +/- 10 micromol/L), there was no significant difference in salivary OA between control subjects (128 +/- 19 micromol/L) and CRF patients (135 +/- 24 micromol/L). The urinary excretion of OA during maximal water diuresis (from 37.5 to 110.3 micromol/4 hours) and after intravenous furosemide (from 34.5 to 66.7 micromol/3 hours) increased significantly, but was not affected by high intake of NaCl. The most significant decrease of plasma OA was observed during postdilution hemodiafiltration (63.3%). CONCLUSION: Our study indicates that renal replacement therapy is not effective for a permanent reduction of elevated plasma levels of OA.
Asunto(s)
Enfermedades Renales/inducido químicamente , Fallo Renal Crónico/inducido químicamente , Ácido Oxálico/toxicidad , Uremia/inducido químicamente , Adulto , Ácido Ascórbico/sangre , Aterosclerosis/epidemiología , Creatinina/sangre , Femenino , Glomerulonefritis/sangre , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/epidemiología , Fallo Renal Crónico/sangre , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/terapia , Trasplante de Riñón/efectos adversos , Trasplante de Riñón/fisiología , Masculino , Persona de Mediana Edad , Ácido Oxálico/sangre , Diálisis Peritoneal Ambulatoria Continua , Diálisis Renal , Vitamina B 6/uso terapéuticoRESUMEN
Laboratory bioassays were performed to characterize the acute contact toxicity of oxalic acid (OA) to Varroa destructor (Anderson and Trueman) and their honey bee hosts (Apis mellifera L.). Specifically, glass-vial residual bioassays were conducted to determine the lethal concentration of OA for V. destructor, and topical applications of OA in acetone were conducted to determine the lethal dose for honey bees. The results indicate that OA has a low acute toxicity to honey bees and a high acute toxicity to mites. The toxicity data will help guide scientists in delivering optimum dosages of OA to the parasite and its host, and will be useful in making treatment recommendations. The data will also facilitate future comparisons of toxicity if mite resistance to OA becomes evident.
Asunto(s)
Abejas/efectos de los fármacos , Insecticidas/toxicidad , Ácaros , Ácido Oxálico/toxicidad , Animales , Abejas/parasitología , Interacciones Huésped-ParásitosRESUMEN
BACKGROUND AND AIMS: Once human skin contacts stinging hairs of Urtica spp. (stinging nettles), the irritant is released and produces pain, wheals or a stinging sensation which may last for >12 h. However, the existence of pain-inducing toxins in the stinging hairs of Urtica thunbergiana has never been systematically demonstrated. Experiments were therefore conducted to identify the persistent pain-inducing agents in the stinging hairs of U. thunbergiana. METHODS: The stinging hairs of U. thunbergiana were removed and immersed in deionized water. After centrifugation, the clear supernatants were then subjected to high-performance liquid chromatography (HPLC), enzymatic analysis and/or behavioural bioassays. KEY RESULTS: The HPLC results showed that the major constituents in the stinging hairs of U. thunbergiana were histamine, oxalic acid and tartaric acid. However, the well-recognized pain-inducing agents, serotonin and formic acid, existed at a low concentration as estimated by HPLC and/or enzymatic analyses. The behavioural tests showed that 2% oxalic acid and 10% tartaric acid dramatically elicited persistent pain sensations in rats. In contrast, 10% formic acid and 2% serotonin only elicited moderate pain sensation in the first 10 min. Moreover, no significant pain-related behavioural response was observed after injecting 10% acetylcholine and histamine in rats. CONCLUSIONS: Oxalic acid and tartaric acid were identified, for the first time, as major long-lasting pain-inducing toxins in the stinging hairs of U. thunbergiana. The general view that formic acid, histamine and serotonin are the pain-inducing agents in the stinging hairs of U. dioica may require updating, since their concentrations in U. thunbergiana were too low to induce significant pain sensation in behavioural bioassays.