RESUMO
We present a case of a 69-year-old man who presented for routine check-up and was incidentally found to have kidney failure with an initially unrevealing history and bland urinary sediment. He was diagnosed with oxalate nephropathy in the setting of chronic turmeric supplementation and chronic antibiotic therapy with associated diarrhea. Our case provides several key insights into oxalate nephropathy. First, the diagnosis requires a high index of clinical suspicion. It is uncommonly suspected clinically unless there is an obvious clue in the history such as Roux-en-Y gastric bypass or ethylene glycol poisoning. Diagnosis can be confirmed by histopathologic findings and corroborated by serum levels of oxalate and 24-hour urinary excretion. Second, the diagnosis can often be missed by the pathologist because of the characteristics of the crystals unless the renal pathologist has made it a rule to examine routinely all H&E sections under polarized light. This must be done on H&E, as the other stains dissolve the crystals. Third, one oxalate crystal in a routine needle biopsy is considered pathologic and potentially contributing to the AKI or to the CKD in an important way. Fourth, secondary oxalosis can be largely mitigated or prevented in many cases, especially iatrogenic cases. This can come through the surgeon or the gastroenterologist providing proper instructions to patients on an oxalate-restricted diet or other specific dietary measures. Lastly, this case highlights the success that results from cooperation and communication between the pathologist and the treating physician.
Assuntos
Hiperoxalúria , Insuficiência Renal , Masculino , Humanos , Idoso , Curcuma , Hiperoxalúria/induzido quimicamente , Hiperoxalúria/complicações , Insuficiência Renal/complicações , Oxalatos , Suplementos Nutricionais/efeitos adversosRESUMO
Tioconazole is an effective antifungal agent with very low solubility in aqueous media, which limits its bioavailability and efficacy. Aiming to overcome the drug limitations by improving the solubility of this active pharmaceutical ingredient, solution precipitation techniques were employed to prepare four new crystalline salts, namely the mesylate, tosylate, maleate (1:1), and fumarate (1:1) hemihydrate. The thermal stabilities, dissolution properties, and structural characteristics of the solids were determined, and the study was extended to compare their properties with the already-known oxalate salt. The structural characterization of the new phases was carried out using a multi-method approach, which included thermal (differential scanning calorimetry and thermogravimetry), diffractometric (powder X-ray diffraction), and spectroscopic (near-infrared and mid-infrared) methodologies. The determination of the melting point of the salts confirmed the findings made by thermal methods. Functional characteristics of the salts, involving their intrinsic dissolution rates were also determined. It was found that the salts exhibited improved thermal stability and that the nature of the counterion modulated their dissolution characteristics. The salts displayed better intrinsic dissolution rates than the free base, to the point of being "highly soluble" according to the Biopharmaceutical Classification System. At pH 4.3, the sulfonic acid derivatives exhibited better dissolution rates than their carboxylic acid-derived counterparts, greatly improved regarding bare tioconazole. The results suggest that the salts have great potential to be used as replacements for the free base; in principle, careful salt selection may help to fulfill each solubility need for the different scenarios where the drug may be used.
Assuntos
Imidazóis , Sais , Sais/química , Difração de Raios X , Oxalatos , Solubilidade , Varredura Diferencial de CalorimetriaRESUMO
This work aimed to investigate the impact of hydrogen peroxide (HP) punctual dosage on paracetamol (PCT) degradation, through Fenton and photo-Fenton processes under near-neutral pH conditions, using ferrioxalate and artificial sunlight. The assays were performed using a D-optimal experimental design, to statistically evaluate the influence of radiation (ON or OFF), HP concentration (94.5-756 mg L-1), and HP dosage (YES or NO), on PCT conversion. The optimal conditions determined from the study were: HP = 378 mg L-1, DOS = YES, and RAD = ON, achieving a predicted PCT conversion of 99.68% in 180 min. This result obtained from the model was very close to the experimental one (98.80%). It was verified that HP dosage positively influenced the iron catalytic cycle since higher Fe2+ concentrations were reached at shorter reaction times, accelerating not only PCT conversion but also its by-products hydroquinone and 1,4-benzoquinone, leading to better performances of Fenton and photo-Fenton reactions. Under optimal conditions and employing real water matrices (an artificial matrix with inorganic anions, a real groundwater sample, and a synthetic industrial wastewater), HP dosage demonstrated the ability to mitigate the negative effects caused by the content of different ions and other organic compounds and significantly improve HP consumption in challenging wastewater conditions.
Assuntos
Acetaminofen , Oxalatos , Poluentes Químicos da Água , Acetaminofen/química , Peróxido de Hidrogênio/química , Águas Residuárias , Poluentes Químicos da Água/análise , OxirreduçãoRESUMO
Amaranthus spp. is a nephrotoxic plant with unknown toxic principle, affecting production animals worldwide, mainly in South America. The aim of this paper is to describe 5 spontaneous outbreaks of A. hybridus intoxication in beef cattle, where 7 autopsies were performed. Main gross findings were pale diffuse and enlarged kidneys. Microscopically, kidneys were characterized by severe tubular acute to subacute nephrosis, with dilatated tubules showing different degrees of epithelial degeneration and necrosis, and containing intraluminal eosinophilic hyaline casts. Intratubular birefringent crystals, compatible with oxalate, were observed under polarized light in kidneys from 3 autopsies. Positive von Kossa and red alizarin S staining confirmed the intratubular crystals as calcium deposits. This intoxication occurs mainly in stubble paddocks during summer and early autumn. The data from the present study suggests that oxalates were related to nephrotoxicity due to Amaranthus consumption.
Assuntos
Amaranthus , Nefropatias , Animais , Bovinos , Argentina , Rim , Nefropatias/veterinária , OxalatosRESUMO
This study provides a comprehensive account of the various types of calcium oxalate crystals found in the genus Baccharis and assesses the exceptional value of crystal macropatterns for the taxonomy of the genus. The morphotype, occurrence, and chemical composition of the crystals found in the stems and leaves are studied. The 44 species included in this study were selected based on a broad phylogeny-based sampling covering seven subgenera and 31 sections. These species were chosen to represent all the main phylogenetic lineages of Baccharis; thus, the sampling also represents a comprehensive coverage concerning evolutionary significance for such a large and environmentally and economically important plant group. The samples were analyzed by light microscopy, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS). Several morphotypes of crystals, including druses, crystal sand, styloids and prisms, were present. Based on their chemical composition, the crystals were classified as pure calcium oxalate, mixtures of oxalates and sulfates, and mixtures of oxalates, sulfates, and silica. The crystal macropatterns observed in this study aid in species identification and provide novel data for the taxonomy of Baccharis. RESEARCH HIGHLIGHTS: Most species of Baccharis have a specific crystalline pattern. Each species produces a crystal morphotype or a set of morphotypes specific to it. The crystals observed are formed by calcium oxalate.
Assuntos
Baccharis , Oxalato de Cálcio , Oxalato de Cálcio/química , Filogenia , Microscopia Eletrônica de Varredura , Oxalatos , SulfatosRESUMO
A female juvenile green turtle (Chelonia mydas), found alive in Guanabara Bay, Rio de Janeiro, Brazil, was weak, dehydrated and cachectic, with a healed fracture in the caudal portion of the carapace. Despite supportive treatment, the animal died after 9 days. At necropsy the main lesions were pallor of visceral organs, arthritis and deposits of whitish granular material in the wall of large arteries and the trachea. Histopathological analysis revealed mild to severe deposition of crystals, consistent with calcium oxalate, in both kidneys and the spleen, heart, small intestine, pancreas, thymus and salt gland, as well as bacterial meningitis, septic arthritis, spirorchidiasis and a fibropapilloma on the nictitating membrane. The main pathological findings were suggestive of septic shock, mainly due to the bacterial meningitis and septic arthritis, with systemic oxalosis and spirorchidiasis as contributing lesions. Although renal oxalosis has been described in green turtles as an incidental finding, presumably due to ingestion of oxalate-containing plants, this turtle had an unusual systemic deposition of oxalate crystals.
Assuntos
Artrite Infecciosa , Hiperoxalúria , Tartarugas , Animais , Brasil , Hiperoxalúria/veterinária , Oxalatos , Artrite Infecciosa/veterináriaRESUMO
Secretion of oxalic acid from roots is an important aluminum detoxification mechanism for many plants such as Hevea brasiliensis (rubber tree). However, the underlying molecular mechanism and oxalate transporter genes in plants have not yet been reported. In this study, the oxalate transporter candidate genes HbOT1 and HbOT2 from the rubber tree were cloned and preliminarily identified. It was found that HbOT1 had a full length of 1163 bp with CDS size of 792 bp, encoding 263 amino acids, and HbOT2 had a full length of 1647 bp with a CDS region length of 840 bp, encoding 279 amino acid residues. HbOT1 and HbOT2 were both stable hydrophobic proteins with transmembrane structure and SNARE_assoc domains, possibly belonging to the SNARE_assoc subfamily proteins of the SNARE superfamily. qRT-PCR assays revealed that HbOT1 and HbOT2 were constitutively expressed in different tissues, with HbOT1 highly expressed in roots, stems, barks, and latex, while HbOT2 was highly expressed in latex. In addition, the expressions of HbOT1 and HbOT2 were up-regulated in response to aluminum stress, and they were inducible by metals, such as copper and manganese. Heterologous expression of HbOT1 and HbOT2 in the yeast mutant AD12345678 enhanced the tolerance to oxalic acid and high concentration aluminum stress, which was closely correlated with the secretion of oxalic acid. This study is the first report on oxalate transporter genes in plants, which provides a theoretical reference for the study on the molecular mechanism of oxalic acid secretion to relieve aluminum toxicity and on aluminum-tolerance genetic engineering breeding.
Assuntos
Hevea , Hevea/genética , Hevea/metabolismo , Oxalatos/metabolismo , Alumínio/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismoRESUMO
ABSTRACT: A 19-year-old girl presented to the emergency department with a progressively painful purpuric lesion on the left dorsal foot, which had initially appeared 2 days prior. Three months earlier, she had been diagnosed with end-stage renal disease. Her medical history also included recurrent urolithiasis for the past 5 years and liver failure. Biopsy revealed oxalate crystals occluding vessels with secondary epidermal and dermal ischemia. Oxalate crystals were also visualized in the vessel walls and free in the subcutis. Genetic testing confirmed the diagnosis of primary hyperoxaluria type 1. She was treated with sodium thiosulfate, apixaban, pentoxifylline, wound care, and palliative care. At 4-month follow-up, the cutaneous manifestations of oxalosis were confined to only her feet, and she was undergoing evaluation for combined liver and kidney transplant. Cutaneous oxalosis because of primary hyperoxaluria should be considered in young patients presenting with purpuric lesions, recurrent urolithiasis, and early-onset renal failure.
Assuntos
Hiperoxalúria Primária , Hiperoxalúria , Falência Renal Crônica , Urolitíase , Humanos , Feminino , Adulto Jovem , Adulto , Hiperoxalúria Primária/complicações , Hiperoxalúria Primária/diagnóstico , Hiperoxalúria Primária/terapia , Falência Renal Crônica/complicações , Urolitíase/complicações , OxalatosRESUMO
The aim of this work was to identify the main chemical constituents and to evaluate the antilithiatic activity of the aqueous and hydroalcoholic extracts of stems of Caesalpinia bahamensis Lam. Fractionation and isolation of constituents from the hydroalcoholic extract was carried out by flash chromatography and semi-preparative liquid chromatography. The antilithiatic activity of the aqueous and hydroalcoholic extracts was evaluated in Wistar rats, where kidney stones were induced by ethylene glycol and ammonium chloride. Creatinine, calcium, and oxalate levels were evaluated and histological analysis was carried out. The homoisoflavonoids protosappanin B, 10-methyl-protosappanin B and brazilin were isolated and the antilithiatic activity of the aqueous and hydroalcoholic extracts was demonstrated by the reduction of the concentration of calcium and oxalate in urine compared to the lithiasis group. It was corroborated by histological analysis. Brazilin and protosappanin B were proposed as chemical markers for this plant species.
Assuntos
Caesalpinia , Animais , Caesalpinia/química , Cálcio , Oxalatos , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos WistarRESUMO
The tomato leaf miner, Tuta absoluta (Meyrick), is the most important pest for tomato production in Iran. The effect of flubendiamide and thiocyclam hydrogen oxalate insecticides was assessed on cellular energy allocation (CEA) of the third instar larvae of T. absoluta ingesting six different tomato cultivars. Plant leaves were treated with LC50 concentration of both insecticides and their energy available (Ea), energy consumption (Ec), and CEA were calculated. The results showed that total energy reserves (protein, carbohydrate, and lipid budgets) were significantly reduced after exposure to insecticides and tomato secondary metabolites. The larvae fed on Riogrande and Super Chief cultivars showed the least amount of energy available after treatment with both insecticides. The highest rate of oxygen consumption was observed in larvae fed on Calj, Super Luna, and Super strain B after treatment with flubendiamide. The amount of CEA decreased in treated larvae compared to untreated larvae. This reduction was statistically higher in treated larvae that fed on Riogrande and Super strain B cultivars. Reduction in CEA is probably due to the expenses of dealing with detoxification of insecticides and plant metabolites. CEA is a suitable and primary biomarker for the effects of cultivars and insecticides as integrate and summarizes insect energy allocation in variable situations.