Hypoxanthine urolithiasis in an 11-month-old child: A case report of

Hereditary xanthinuria is a novel autosomal recessive disorder of purine metabolism resulting from the deficiency of xanthine dehydrogenase. An 11-month-old boy admitted with the complaints of irritability for 6 months, darkening of the urine and spontaneous passage of stone. Both serum and urine levels of uric acid were below normal. Urinary ultrasonography was normal. Stone analysis revealed that it was a hypoxanthine stone. The case is reported because hereditary xanthinuria is a rare cause of childhood urolithiasis. J Clin Exp Invest 2014; 5 (1): 128-13

Xanthinuria: a rare cause of urolithiasis in the cat

Xanthinuria is a very rare disease in cats. Its etiology may have a genetic origin or may be due to an iatrogenic xan- thine-dehydrogenase inhibition that nally results in urolithiasis. The present work reports two cases of xanthine uro- lithiasis in European Shorthair unrelated male and female cats. Both uroliths were analyzed by stereoscopic microsco- py, infrared spectroscopy and scanning electron microscopy. Besides the report of these two clinical cases, a detailed pathophysiologic review and some updated recommendations for diagnosis and treatment for this condition were done.La xantinuria es una patología que se presenta raramente en los gatos. Su etiología puede tener origen genético o de- berse a una inhibición yatrogénica de la enzima xantina deshidrogenasa, que generalmente se mani esta con urolitiasis. En este trabajo se informa el hallazgo de dos urolitos de xantina en dos gatos, un macho y una hembra, de raza Euro- pea de pelo corto, no emparentados. Los urolitos fueron analizados mediante microscopía estereoscópica, espectrosco- pía infrarroja y microscopía electrónica de barrido. Además de informar sobre estos casos clínicos, se hace una revisión detallada de la siopatología y de las recomendaciones actuales para el diagnóstico y manejo médico de esta patología.Se agradece al Consejo Nacional de Ciencia y Tecnolo- gía de México (CONACyT) y al Programa de Mejora- miento del Profesorado de la Secretaria de Educación Pública de México 2011 (PROMEP-SEP), el apoyo complementario para la realización de este trabajo

The essential roles of metal ions in insect homeostasis and physiology

Metal ions play distinct roles in living organisms, including insects. Some, like sodium and potassium, are central players in osmoregulation and ‘blood and guts’ transport physiology, and have been implicated in cold adaptation. Calcium is a key player as a second messenger, and as a structural element. Other metals, particularly those with multiple redox states, can be cofactors in many metalloenzymes, but can contribute to toxic oxidative stress on the organism in excess. This short review selects some examples where classical knowledge has been supplemented with recent advances, in order to emphasize the importance of metals as essential nutrients for insect survival

Recurrent exercise-induced acute kidney injury by idiopathic renal hypouricemia with a novel mutation in the SLC2A9 gene and literature review

OBJETIVO: Comparar a sensibilidade do método de difusão em ágar e do método de extração utilizando as linhagens celulares RC-IAL (células fibroblásticas de rim de coelho) e HeLa (células epiteliais de carcinoma do colo do útero humano), na avaliação da citotoxicidade "in vitro" de materiais de uso médico-hospitalar. MATERIAL E MÉTODO: Foram testadas 50 amostras escolhidas por sorteio, entre as já conhecidamente positivas e negativas e identificadas como: algodão, espuma, borracha, látex, celulose e acrílico. Além, das amostras citadas foram testadas experimentalmente várias concentrações de SDS (duodecil sulfato de sódio) nas culturas celulares RC-IAL e HeLa. RESULTADOS: Das 50 amostras testadas , 44 (88%) foram positivas para os dois métodos. Mas quando comparado o SDS nos dois métodos foram observados resultados positivos nas concentrações de 0,5 a 0,05 µg/ml no método de difusão em ágar e no método de extração somente foi observado efeito citotóxico até a concentração de 0,25 µg/ml. CONCLUSÃO: Os resultados encontrados são similares aos observados por outros autores que testaram materiais como, por exemplo, ligas metálicas. Quando foi usado o SDS observou-se, nas duas linhagens celulares, diferenças favoráveis ao método de difusão em ágar em duas concentrações, isto é, a sensibilidade deste método foi significantemente maior, por inspecção, em relação ao método de extração, além de se constituir em método mais simples de ser realizado

Review on the risks associated to allopurinol therapy in dogs with canine Leishmaniosis

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Functional studies on oligotropha carboxidovorans molybdenum–copper CO dehydrogenase produced in escherichia coli

The Mo/Cu-dependent CO dehydrogenase (CODH) from Oligotropha carboxidovorans is an enzyme that is able to catalyze both the oxidation of CO to CO2 and the oxidation of H2 to protons and electrons. Despite the close to atomic resolution structure (1.1 Å), significant uncertainties have remained with regard to the reaction mechanism of substrate oxidation at the unique Mo/Cu center, as well as the nature of intermediates formed during the catalytic cycle. So far, the investigation of the role of amino acids at the active site was hampered by the lack of a suitable expression system that allowed for detailed site-directed mutagenesis studies at the active site. Here, we report on the establishment of a functional heterologous expression system of O. carboxidovorans CODH in Escherichia coli. We characterize the purified enzyme in detail by a combination of kinetic and spectroscopic studies and show that it was purified in a form with characteristics comparable to those of the native enzyme purified from O. carboxidovorans. With this expression system in hand, we were for the first time able to generate active-site variants of this enzyme. Our work presents the basis for more detailed studies of the reaction mechanism for CO and H2 oxidation of Mo/Cu-dependent CODHs in the future

A novel homozygous SLC2A9 mutation associated with renal-induced hypouricemia

Hereditary renal hypouricemia (RHUC) is a genetically heterogenous disorder characterized by defective uric acid (UA) reabsorption resulting in hypouricemia and increased fractional excretion of UA; acute kidney injury (AKI) and nephrolithiasis are recognized complications. Type 1 (RHUC1) is caused by mutations in the SLC22A12 gene, whereas RHUC2 is caused by mutations in the SLC2A9 gene. Patient ethnicity is diverse but only few Caucasian families with an SLC2A9 mutation have been reported. The current report describes the clinical history, biochemical and molecular genetics findings of a native Austrian family with RHUC2. The propositus presented with 2 episodes of exercise-induced AKI and exhibited profound hypouricemia. Mutational screening of the SLC22A12 and SLC2A9 genes was performed. The molecular analyses revealed the homozygous c.512G>A transition that leads to the p.Arg171His missense substitution in SLC2A9, confirming the diagnosis of RHUC2. Segregation study of the causal mutation revealed that the mother and elder sister were heterozygous carriers, whereas the younger sister was found to be homozygous. We report the identification of a novel mutation in SLC2A9 as the cause of RHUC2 in a native Austrian family. We show that glucose transporter 9 mutations cause severe hypouricemia in homozygous individuals and confirm the high risk of AKI in male individuals harbouring these mutations. In our literature review, we provide an overview of the putative underlying pathophysiology, potential renal complications, findings on kidney biopsy as well as potential long-time renal sequela

Xanthinuria secondary to allopurinol treatment in dogs with leishmaniosis: current perspectives of the Iberian veterinary community

Research Areas: Immunology ; Microbiology ; Veterinary SciencesXanthinuria is a significant adverse effect in dogs on long-term allopurinol for treatment of leishmaniosis. The study aims to investigate how the Iberian veterinary community (IVC) identifies, manages, and proactively prevents xanthinuria secondary to allopurinol treatment. A cross-sectional study was conducted using an online survey, translated into two languages, and disseminated to the IVC via social networking forums. Respondents were asked to share their treatment regimens, adverse effects attributed to treatment, as well as preventive and reactive measures against xanthuria. Of two-hundred and thirty respondents, 99.6% prescribe allopurinol for canine leishmaniosis. Xanthinuria was estimated to happen in less than one out of every four dogs by 91.7% of the clinicians. Xanthinuria has been detected by 71.6% of respondents at least once. Three out of every four respondents inform owners about deleterious effects of allopurinol, and 28.4% consider implementing a change in diet in advance of treatment as a proactive measure. To monitor xanthinuria, urinalysis and diagnostic imaging are used by 71.2% and 31% of clinicians respectively. When xanthinuria is detected, 43.2% of the respondents discontinue allopurinol, 24% replace it by nucleotide-analogs, 14.9% reduce its dosage, and 3.1% split its dosage but increase administration frequency. Additional measures are taken by 72.1% of the respondents, 59.4% of whom prescribe a low-purine diet. The IVC recognizes xanthinuria as a fairly common secondary effect of long-term allopurinol treatment in dogs with leishmaniosis and recommends periodically monitoring and preventive measures.info:eu-repo/semantics/publishedVersio