Cystatin C and Iris: Advances in the Evaluation of Kidney Function in Critically Ill Dog.

Critically ill hospitalized dogs are subject to certain complications, being acute kidney injury (AKI) a common one. Early diagnosis is crucial, and Cystatin C (CysC) is a reliable and early biomarker. The International Society of Renal Interest (IRIS) states that AKI severity can be assessed by mild changes in creatinine serum levels or reduction of urine output that cannot be considered biomarkers of renal injury but failure or insufficiency. Twenty-eight dogs admitted to the Intensive Care Unit under risk factors for the development of AKI were evaluated. Blood samples were collected for determination of sCr and CysC at admission and after 24, 48, and 72 h. Urine output was measured by daily monitoring, measured by collection in a closed system. The results showed the incidence of AKI was 67.9% based on the IRIS criteria and 78.6% based on cystatin C in critically ill patients' dogs. The measurement of serum cystatin C immediately on admission to the ICU was superior in the early identification of patients with AKI when compared to the IRIS classification and serum creatinine in critically ill dogs.

Cistatina C sérica em cães criticamente enfermos em UTI / Cystatin C in critically ill dogs at UTI

A lesão renal aguda (IRA) é uma síndrome complexa, associada à progressão desfavorável, especialmente em cães na unidade de terapia intensiva (UTI) e apresenta alta morbidade e mortalidade. O diagnóstico de IRA requer combinação de testes laboratoriais, como a creatinina sérica e ureia, considerados pouco sensíveis e específicos para a detecção precoce de graus discretos durante a perda de função renal. O biomarcador cistatina C é considerado superior por apresentar uma melhor correlação com a taxa de filtração glomerular. No entanto, existem poucos estudos que demonstram a utilidade da cistatina C em cães na UTI. O objetivo deste estudo foi comparar a cistatina C com o nível sérico de creatinina para detectar o estágio inicial da IRA em cães em terapia intensiva. As dosagens desses analitos foram realizadas no momento da admissão, 24 e 48 horas após. A cistatina C apresentou concentrações mais elevadas em 78,6%, enquanto a creatinina sérica aumentou apenas em 28,5% dos cães. Os resultados demonstraram que a cistatina C pode ser utilizada para a detecção precoce de lesão renal aguda em cães de UTIs devido à sua maior sensibilidade em relação aos marcadores tradicionais.(AU)

Acute kidney injury (AKI) is a complex syndrome, associated with unfavorable progression, especially in dogs in the intensive care unit (ICU), and presents high morbidity and mortality. The diagnosis of AKI requires a combination of laboratory tests, such as serum creatinine and urea, considered to be poorly sensitive and specific for the early detection of discrete degrees during loss of renal function. The biomarker cystatin C is considered superior because it has a better correlation with the glomerular filtration rate. However, there are few studies that demonstrate the utility of cystatin C in dogs in ICU. The objective of this study was to compare cystatin C to creatinine serum level to detect early stage of AKI in dogs in an intensive care. Measurements of these analytes were performed at the time of admission, 24 and 48 hours after. Serum cystatin C presented higher concentrations in 78.6% while serum creatinina elevated in only 28.5% of the dogs. The results demonstrated that cystatin C can be used for the early detection of acute kidney injury in dogs in ICUs because of its greater sensitivity compared to traditional markers.(AU)

Determination of the reference interval for the activity of NAcetyl-ß-D-glucosaminidase (NAG) in urine of healthy dogs / Determinação de intervalo de referência para a atividade da NAcetyl-ß-D-glucosaminidase (NAG) na urina de cães sadios

The diagnosis of acute kidney injury by evaluating the activity of urinary enzymes is an important tool especially for its precocity in relation to methods of assessment of renal function considered late as the installation of injury precedes the function change. This study was performed to determine the reference interval for urinary NAG activity (N-Acetyl-β-D-glucosaminidase) in urine of healthy dogs of different breeds, ages and sexes. It was utilized an automated method for the determination of NAG activity standardized for dog urine samples. Through statistical analysis it was observed that NAG is positively correlated with the age of the animal and urine specific gravity but is not interfered by sex or weight. Based on the determination of urinary activity and after correcting the values for a 1,025 urine specific gravity was obtained an reference interval of X '= 3.62U/L±0.66U/L.(AU)

O diagnóstico da injúria renal aguda pela avaliação da atividade de enzimas urinárias é uma importante ferramenta para o médico veterinário, especialmente por sua precocidade em relação aos métodos de avaliação da função renal, considerados tardios, visto que a instalação da injúria precede a alteração da função. Neste estudo foi realizada a determinação do intervalo de referência médio para a atividade urinária de NAG (N-Acetyl- β-D-Glucosaminidase), em urinas de cães hígidos, de diferentes raças, sexos e faixas etárias. Para isso, trabalhou-se com um método automatizado para determinação da atividade de NAG, padronizado para amostras de urina de cães. Por meio de análise estatística, observou-se que a NAG apresenta correlação positiva com a idade do animal e com a densidade urinária, mas não sofre interferência quanto ao sexo ou peso. Com base na determinação da atividade urinária e após corrigir os valores para uma densidade de 1,025, obteve-se um intervalo de referência médio de X´ = 3,62U/L±0,66U/L.(AU)

Small angle x-ray scattering of the hemoglobin from Biomphalaria glabrata.

The hemoglobin from Biomphalaria glabrata is an extracellular respiratory protein of high molecular mass composed by subunits of 360 kDa, each one containing two 180 kDa chains linked by disulfide bridges. In this work, small angle x-ray scattering (SAXS) measurements were performed with the hemoglobin at pH 5.0 and 7.5. Radii of gyration of 98.6 +/- 0.5 and 101.8 +/- 0.2 A and maximum diameters of 300 +/- 10 and 305 +/- 10 A, respectively, were obtained from Guinier plot extrapolation and analytical curve fitting. The pair distance distribution functions p(r) corresponded to globular particles with a somewhat anisotropic shape for both preparations. Computer analysis of the low angle part of the scattering curve led to the determination of the low resolution envelope of the protein, revealing a P(222) symmetry. Shape reconstruction from ab initio calculations using the complete scattering curve furnished a compact prolate three-dimensional (3D) bead model for the protein. Hydrodynamic parameters were obtained from experiments and theoretical calculations using the 3D model. The results of the structural and biochemical studies reported herein indicate that the multisubunit structure of this hemoglobin is compatible with a tetrameric arrangement.