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1.
J Sci Food Agric ; 100(4): 1797-1805, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31849061

RESUMO

BACKGROUND: Two consecutive trials were carried out to study the effects of dietary supplementation of rumen-protected methionine (RPM) on nutrient digestibility, nitrogen (N) metabolism (Trial 1), and consequently the nitrous oxide (N2 O) emissions from urine in beef cattle (Trial 2). Eight 24-month-old castrated Simmental bulls with liveweights of 494 ± 28 kg, and four levels of dietary supplementation of RPM at 0, 10, 20, and 30 g head-1 d-1 , were allocated in a replicated 4 × 4 Latin square for Trial 1 and the N2 O emissions from the urine samples collected in Trial 1 were measured using a static incubation technique in Trial 2. RESULTS: Supplementation of RPM at 0, 10, 20, and 30 g head-1 d-1 to a basal ration deficient in methionine (Met) did not affect the apparent digestibility of dry matter, organic matter, neutral detergent fiber, or acid detergent fiber (P > 0.05), but decreased the urinary excretions of total N (P < 0.05) and urea (P < 0.001), increased the ratio of N retention / digested N (P < 0.05) in beef cattle, and decreased the estimated cattle urine N2 O-N emissions by 19.5%, 23.4%, and 32.6%, respectively (P < 0.001). CONCLUSION: Supplementation of RPM to Met-deficient rations was effective in improving the utilization rate of dietary N and decreasing the N2 O emissions from urine in beef cattle. © 2019 Society of Chemical Industry.


Assuntos
Bovinos/metabolismo , Metionina/metabolismo , Nitrogênio/urina , Óxido Nitroso/urina , Rúmen/metabolismo , Ureia/urina , Urina/química , Ração Animal/análise , Animais , Bovinos/urina , Suplementos Nutricionais/análise
2.
Ceska Slov Farm ; 68(4): 173-179, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31822110

RESUMO

The article presents the results of the study of the nephroprotective effect of N-acetylglucosamine (NAG) under the development of experimental acute kidney injury (AKI). The study was conducted on a model of acute glycerol nephrosis in rats. NAG was studied at a dose of 50 mg/kg at daily parenteral administration during 1 week compared to quercetin, which was administered intraperitoneally at a dose of 34 mg/kg. The efficiency of the drugs was assessed by the functional state of animals, the renal excretory function and the nitrogen metabolism indices. The NAG effect on rats with AKI caused a reduction of the mortality rate, an increase in diuresis, a reduction of proteinuria, an increase in creatinine and urea excretion, which indicates the normalization of the renal excretory function and nitrogen metabolism. At the same time, NAG has statistically significantly exceeded the effect of quercetin in the majority of indices and, therefore, the level of efficiency. Thus, NAG is an efficient agent for AKI treatment, which can be used at parenteral route of administration.


Assuntos
Acetilglucosamina/farmacologia , Lesão Renal Aguda/tratamento farmacológico , Animais , Creatinina/urina , Diurese , Proteinúria , Quercetina/farmacologia , Ratos , Ureia/urina
3.
PLoS One ; 14(11): e0224565, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31725748

RESUMO

BACKGROUND: Muscle wasting in the critically ill is up to 2% per day and delays patient recovery and rehabilitation. It is linked to inflammation, organ failure and severity of illness. The aims of this study were to understand the relationship between muscle depth loss, and nutritional and inflammatory markers during prolonged critical illness. Secondly, to identify when during critical illness catabolism might decrease, such that targeted nutritional strategies may logically be initiated. METHODS: This study was conducted in adult intensive care units in two large teaching hospitals. Patients anticipated to be ventilated for >48 hours were included. Serum C-reactive protein (mg/L), urinary urea (mmol/24h), 3-methylhistidine (µmol/24h) and nitrogen balance (g/24h) were measured on days 1, 3, 7 and 14 of the study. Muscle depth (cm) on ultrasound were measured on the same days over the bicep (bicep and brachialis muscle), forearm (flexor compartment of muscle) and thigh (rectus femoris and vastus intermedius). RESULTS: Seventy-eight critically ill patients were included with mean age of 59 years (SD: 16) and median Intensive care unit (ICU) length of stay of 10 days (IQR: 6-16). Starting muscle depth, 8.5cm (SD: 3.2) to end muscle depth, 6.8cm (SD: 2.2) were on average significantly different over 14 days, with mean difference -1.67cm (95%CI: -2.3 to -1cm), p<0.0001. Protein breakdown and inflammation continued over 14 days of the study. CONCLUSION: Our patients demonstrated a continuous muscle depth loss and negative nitrogen balance over the 14 days of the study. Catabolism remained dominant throughout the study period. No obvious 'nutritional tipping point" to identify anabolism or recovery could be identified in our cohort. Our ICU patient cohort is one with a moderately prolonged stay. This group showed little consistency in data, reflecting the individuality of both disease and response. The data are consistent with a conclusion that a time based assumption of a tipping point does not exist. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number: ISRCTN79066838. Registration 25 July 2012.


Assuntos
Proteína C-Reativa/metabolismo , Citidina/análogos & derivados , Tempo de Internação , Músculo Esquelético , Atrofia Muscular , Ureia/urina , Adulto , Idoso , Estado Terminal , Citidina/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Atrofia Muscular/sangue , Atrofia Muscular/fisiopatologia , Atrofia Muscular/urina
4.
PLoS One ; 14(9): e0222115, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31560690

RESUMO

Raman chemometric urinalysis (Rametrix™) was used to analyze 235 urine specimens from healthy individuals. The purpose of this study was to establish the "range of normal" for Raman spectra of urine specimens from healthy individuals. Ultimately, spectra falling outside of this range will be correlated with kidney and urinary tract disease. Rametrix™ analysis includes direct comparisons of Raman spectra but also principal component analysis (PCA), discriminant analysis of principal components (DAPC) models, multivariate statistics, and it is available through GitHub as the Rametrix™ LITE Toolbox for MATLAB®. Results showed consistently overlapping Raman spectra of urine specimens with significantly larger variances in Raman shifts, found by PCA, corresponding to urea, creatinine, and glucose concentrations. A 2-way ANOVA test found that age of the urine specimen donor was statistically significant (p < 0.001) and donor sex (female or male identification) was less so (p = 0.0526). With DAPC models and blind leave-one-out build/test routines using the Rametrix™ PRO Toolbox (also available through GitHub), an accuracy of 71% (sensitivity = 72%; specificity = 70%) was obtained when predicting whether a urine specimen from a healthy unknown individual was from a female or male donor. Finally, from female and male donors (n = 4) who contributed first morning void urine specimens each day for 30 days, the co-occurrence of menstruation was found statistically insignificant to Rametrix™ results (p = 0.695). In addition, Rametrix™ PRO was able to link urine specimens with the individual donor with an average of 78% accuracy. Taken together, this study established the range of Raman spectra that could be expected when obtaining urine specimens from healthy individuals and analyzed by Rametrix™ and provides the methodology for linking results with donor characteristics.


Assuntos
Urinálise/métodos , Urina/química , Adolescente , Adulto , Idoso , Creatinina/urina , Análise Discriminante , Feminino , Glicosúria/urina , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Componente Principal , Valores de Referência , Análise Espectral Raman/métodos , Ureia/urina , Urinálise/estatística & dados numéricos , Adulto Jovem
5.
Physiol Res ; 68(5): 785-792, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31424252

RESUMO

The former perception of the urothelium as an impermeable barrier has been revised during the last decade, as increasing evidence of changes in urine composition during its passage of the urinary tract has been presented. Since differences in urothelial permeability between upper and lower urinary tract have been found, our aim is to demonstrate whether changes in urine composition occur during passage through the ureter. We studied consecutive urine samples from both renal pelvises in six pigs and compared them to samples from the bladder and distal ureter. We further sampled urine during storage in the bladder at a fixed volume. All samples were analysed by measuring osmolality and pH, along with the concentration of the following parameters: Na(+), K(+), Cl(-), creatinine, urea. Urine alkalinity increased significantly during passage of the ureter. Creatinine concentration, pH and K(+) increased significantly during the passage from pelvis to the bladder. All other parameters increased non-significantly during the passage to the bladder. The increase in concentration was more pronounced at low concentrations in the pelvis. During storage in the bladder, there was a significant increase in urea concentration. Changes in the composition of urine occur during its passage from the renal pelvis to the bladder and during storage in the bladder. Despite the brief transit time, significant changes in alkalinity were found already during passage through the ureter.


Assuntos
Capacidade de Concentração Renal , Ureter/metabolismo , Bexiga Urinária/metabolismo , Urina/química , Animais , Cloretos/urina , Creatinina/urina , Feminino , Concentração de Íons de Hidrogênio , Concentração Osmolar , Potássio/urina , Sódio/urina , Sus scrofa , Fatores de Tempo , Ureia/urina
6.
J Anim Sci ; 97(8): 3286-3299, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31242504

RESUMO

The objective of this study was to determine whether feeding tannin-containing hays to heifers and mature beef cows influences enteric methane (CH4) emissions and nitrogen (N) excretion relative to feeding traditional legume and grass hays. Fifteen mature beef cows (Exp. 1) and 9 yearling heifers (Exp. 2) were each randomly assigned to treatment groups in an incomplete bock design with 2 periods and 6 types of hays with 3 hays fed each period (n = 5 cows and 3 heifers per treatment). Groups were fed tannin-containing [birdsfoot trefoil (BFT), sainfoin (SAN), small burnet (SML)] or non-tannin-containing [alfalfa (ALF), cicer milkvetch (CMV), meadow bromegrass (MB)] hays. Each period consisted of 14 d of adjustment followed by 5 d of sample collection. Nine cows and 9 heifers were selected for the measurement of enteric CH4 emissions (sulfur hexafluoride tracer gas technique), and excretion of feces and urine, while dry matter intake (DMI) was measured for all animals. The concentration of condensed tannins in SAN and BFT was 2.5 ± 0.50% and 0.6 ± 0.09% of dry matter (DM), respectively, while SML contained hydrolyzable tannins (4.5 ± 0.55% of DM). Cows and heifers fed tannin-containing hays excreted less urinary urea N (g/d; P < 0.001) and showed lower concentrations of blood urea N (mg/dL; P < 0.001) than animals fed ALF or CMV, indicating that tannins led to a shift in route of N excretion from urine to feces. Additionally, cows fed either BFT or CMV showed the greatest percentage of retained N (P < 0.001). Enteric CH4 yield (g/kg of DMI) from heifers (P = 0.089) was greatest for MB, while daily CH4 production (g/d) from heifers (P = 0.054) was least for SML. However, digestibility of crude protein was reduced for cows (P < 0.001) and heifers (P < 0.001) consuming SML. The results suggest that tannin-containing hays have the potential to reduce urinary urea N excretion, increase N retention, and reduce enteric CH4 emissions from beef cattle. The non-bloating tannin-free legume CMV may also reduce environmental impacts relative to ALF and MB hays by reducing N excretion in urine and increasing N retention.


Assuntos
Bovinos/fisiologia , Metano/metabolismo , Nitrogênio/metabolismo , Proantocianidinas/análise , Taninos/metabolismo , Animais , Dieta/veterinária , Fabaceae/química , Fezes/química , Feminino , Trato Gastrointestinal/química , Poaceae/química , Distribuição Aleatória , Ureia/sangue , Ureia/urina
7.
Anal Chim Acta ; 1073: 54-61, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31146836

RESUMO

This work presents a cost-effective and simple flow injection analysis (FIA) system for simultaneous and direct determination of urea and creatinine in human urine. The FIA system comprises two in-house detectors, a contactless conductivity detector and a light emitting diode (LED) detector. The contactless detector was built as a flow-through detection cell with axial electrodes, commonly known as capacitively coupled contactless conductivity detector (C4D) and the diode detector was fabricated based on the concept of paired emitter detector diodes (PEDD). With appropriate dilution of urine, the sample is directly injected into a stream of glycine-NaOH buffer pH 8.8 (the gas donor stream) and is carried by the carrier through a urease minicolumn for on-line enzymatic hydrolysis. The generated NH3 diffuses from the carrier stream through a porous polytetrafluoroethylene (PTFE) membrane into a stream of deionized water (the acceptor stream) leading to an increase in the signal at the C4D due to the NH3 dissolution in the water. In this system, creatinine is determined based on the Jaffé reaction by merging a stream of alkaline picrate with the gas donor stream. The change in color is detected using the PEDD equipped with two green LEDs. Under the optimum condition, the linear range of urea and creatinine were 30-240 mg L-1 and 10-500 mg L-1, with limits of detection of 9.0 mg L-1 and 0.9 mg L-1, respectively. The proposed system provides satisfactorily good precision (RSD < 3%), with sample throughput of 31 sample h-1 for the two analytes. The FIA system tolerates potential interference commonly found in human urine. The system was successfully applied and validated with selected reference methods.


Assuntos
Colorimetria/economia , Creatinina/urina , Análise de Injeção de Fluxo/economia , Ureia/urina , Condutividade Elétrica , Humanos
8.
Nutr Hosp ; 36(3): 714-717, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31144979

RESUMO

Introduction: Background: protein restriction is the mainstay of dietary management of chronic kidney disease. Aim: to assess the usefulness of urine urea nitrogen measurement as a marker of protein restriction. Methods: healthy young participants were randomly divided in two groups. During 14 days, one group received a diet containing 30 kcal/kg body weight and 1 g protein/kg body weight and the other group received a diet with the same amount of calories and 0.6 g/kg of proteins. At baseline, seven days and 14 days, 24 h dietary recalls were answered by the participants. They collected 24 hour urine and provided spot urine samples at baseline and at the end of the intervention, to measure creatinine and urea nitrogen. Results: forty-one participants aged 29 ± 5 years completed the follow-up. According to 24h dietary recalls, the group receiving 0.6 g/kg protein reduced significantly the protein intake during the intervention from 0.88 ± 0.06 to 0.59 ± 0.05 g/kg/day. A significant reduction in 24 h urea nitrogen excretion was also observed in this group. In the group receiving 1 g/kg of protein, no significant changes in 24 h urea nitrogen excretion were observed. Among all participants, the odds ratio of observing a reduction in protein intake in the dietary survey was 5.75 (95% confidence intervals 1.29-25.55, p = 0.02), when a reduction in 24 h urea nitrogen excretion corrected by creatinine was observed. No changes were observed in urea nitrogen excretion in spot urine samples. Conclusions: repeated urea nitrogen excretion measured in 24 h urine samples can be a reliable indicator of dietary protein restriction.


Assuntos
Dieta com Restrição de Proteínas , Cooperação do Paciente , Ureia/urina , Adolescente , Adulto , Creatinina/urina , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Nitrogênio/urina , Razão de Chances , Insuficiência Renal Crônica/dietoterapia , Adulto Jovem
9.
Clin Nephrol ; 91(6): 344-352, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30935460

RESUMO

AIMS: We attempted to classify 115 consecutive nonedematous hyponatremic patients according to their history and saline responsiveness. We hereby describe 6 out of them presenting a transient renal salt wasting (TRSW) state of unknown origin. MATERIALS AND METHODS: Six patients with an initial SNa of 126 ± 3 mEq/L were included in the study. They were treated with 2 L isotonic saline infusion over 24 hours. The evolution of the biochemical data of 5 patients were compared to 6 patients with syndrome of inappropriate antidiuretic hormone (ADH) secretion (SIADH), 6 hyponatremias following the use of thiazides, and to 5 salt-depleted hyponatremic patients of similar age and body weight, treated in the same way. RESULTS: The mean values of FEurea and FEuric acid in the 6 described patients, together with a clearly inappropriate natriuresis suggested SIADH. However, the high mean fractional potassium excretion (FEK = 34 ± 15%) was not observed in SIADH (13 ± 3%) (p < 0.01). Plasma sodium levels improved quickly after saline infusion in most of these patients, while fractional solute excretions and diuresis decreased. Calciuria is increased in patients with renal salt waisting (RSW), while low calciuria values are observed in the thiazide group. Four of the 6 hyponatremic patients were admitted for syncopal malaise or fall. CONCLUSION: We observed in 6 out of 115 consecutive hyponatremic patients a TRSW. RSW as a diagnosis has to be considered when in hyponatremia with excessive natriuresis, high FEK and an intake of diuretics is ruled out. This hyponatremia is saline-responsive, but relapse can be frequently observed.


Assuntos
Hiponatremia/sangue , Hiponatremia/etiologia , Nefropatias/sangue , Sódio/sangue , Idoso , Idoso de 80 Anos ou mais , Cálcio/urina , Diurese , Diuréticos/efeitos adversos , Feminino , Hidratação , Humanos , Hiponatremia/terapia , Hiponatremia/urina , Síndrome de Secreção Inadequada de HAD/sangue , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/urina , Soluções Isotônicas , Nefropatias/complicações , Nefropatias/urina , Potássio/urina , Solução Salina/uso terapêutico , Tiazidas/efeitos adversos , Ureia/urina , Ácido Úrico/urina
10.
Am J Clin Nutr ; 109(5): 1279-1287, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30997510

RESUMO

BACKGROUND: Reduced net acid excretion (NAE) capacity indicates a decrease in renal function. This reduction manifests as a disproportionally low 24-h urine pH in relation to the sum of actually excreted ammonium and titratable acidity by the kidney. OBJECTIVE: The aim of this study was to test the hypothesis that higher body fatness is one determinant of kidney function impairment with a lowered urine pH even at a young age. METHODS: NAE, pH, urea, and creatinine were measured in 24-h urine samples from 524 healthy children and adolescents (aged 6-17 y) participating in the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study. Body fatness was assessed anthropometrically by body mass index-standard deviation score (BMI-SDS), fat mass index (FMI), body fat % (BF%), and waist circumference (WC). Multivariable linear and mixed linear regressions were used to examine cross-sectionally (n = 524 urine samples; age groups: 6-8, 9-11, 12-14, 15-17 y) and longitudinally (n = 1999 urine samples) the associations of body fatness with 24-h urine pH as the outcome variable, respectively. RESULTS: After adjusting for the kidneys' total net acid load (24-h urinary NAE) and further relevant covariates, FMI showed significant inverse relations with urinary pH in all 4 age groups, and BMI-SDS, BF%, and WC each in 3 out of these 4 groups (P ≤ 0.02). Longitudinal results substantiated these interindividual relations and further showed intraindividual increases in body fatness to be paralleled by urine pH decreases (P ≤ 0.0002). CONCLUSIONS: Independent of underlying acid load, an early increase in body fatness is associated with increased free proton excretion, and thus with a decline in the kidney's acid excretion function, which could potentiate the risk of renal nephrolithiasis.


Assuntos
Ácidos/urina , Tecido Adiposo , Composição Corporal , Rim/fisiopatologia , Obesidade Pediátrica/fisiopatologia , Eliminação Renal , Adolescente , Antropometria , Índice de Massa Corporal , Criança , Creatinina/urina , Feminino , Humanos , Concentração de Íons de Hidrogênio , Rim/fisiologia , Masculino , Obesidade Pediátrica/patologia , Ureia/urina , Circunferência da Cintura
11.
J Vet Intern Med ; 33(3): 1362-1367, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30927388

RESUMO

INTRODUCTION: Acute kidney injury (AKI) leading to severe uremia is associated with high morbidity and mortality. Mannitol is an osmotic diuretic, widely used in the management of AKI, both as a bolus injection and as a constant rate infusion (CRI). OBJECTIVES: To determine the plasma concentration of mannitol after a bolus injection and CRI at the recommended dosages, and to assess the effect of mannitol on renal function variables including urine production, glomerular filtration rate (GFR), and solute excretion. METHODS: Prospective cross-over design study, using 6 healthy dogs. Each dog underwent 3 protocols with at least a 7-day washout period between protocols. The first protocol included bolus injection of mannitol, the second protocol included bolus injection followed by CRI of mannitol and the third protocol (control) included injection of 5% dextrose in water (D5W). Urine production, GFR, and fractional excretion (FE) of solutes were measured for 10 hours. RESULTS: For all protocols, urine production significantly (P < .001) increased after bolus injection, but no significant difference in urine production or GFR was observed among the treatment groups. Mannitol injection increased the FE of sodium and urea nitrogen, but these effects were short-lived. CONCLUSIONS: Mannitol has minimal effect on urine production and GFR but does increase FE of urea nitrogen and sodium, immediately after bolus injection. Constant rate infusion at a conventional dosage of 1 mg/kg/min cannot maintain these effects in dogs with normal renal function, because mannitol concentration decreases rapidly.


Assuntos
Diuréticos Osmóticos/farmacologia , Taxa de Filtração Glomerular/efeitos dos fármacos , Rim/efeitos dos fármacos , Manitol/farmacologia , Animais , Estudos Cross-Over , Diuréticos Osmóticos/administração & dosagem , Cães , Feminino , Taxa de Filtração Glomerular/veterinária , Infusões Intravenosas , Masculino , Manitol/administração & dosagem , Estudos Prospectivos , Sódio/urina , Ureia/urina
12.
Anal Biochem ; 576: 9-12, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30917946

RESUMO

A fast and convenient headspace gas chromatographic (HS-GC) approach was described for the estimation of urea in human urine. The HS-GC could detect the generated carbon dioxide derived from the urease-catalyzed hydrolysis of urea. It was found that the hydrolysis of urea catalyzed by urease was completed within 40 min at 35 °C. The results proved the great accuracy (relative errors ≤ 8.48%) and precision (RSD ≤ 2.66%) of the HS-GC approach. Moreover, the recoveries ranged from 97.9% to 101.5%. The new approach is rapid and automated, which provides a new way to routinely analyze urea in urine for the control of metabolic disease.


Assuntos
Cromatografia Gasosa/métodos , Ureia/urina , Humanos , Padrões de Referência , Ureia/normas
13.
PLoS One ; 14(2): e0212458, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30817767

RESUMO

BACKGROUND AND AIMS: Inborn errors of purine and pyrimidine metabolism are a diverse group of disorders with possible serious or life-threatening symptoms. They may be associated with neurological symptoms, renal stone disease or immunodeficiency. However, the clinical presentation can be nonspecific and mild so that a number of cases may be missed. Previously published assays lacked detection of certain diagnostically important biomarkers, including SAICAr, AICAr, beta-ureidoisobutyric acid, 2,8-dihydroxyadenine and orotidine, necessitating the use of separate assays for their detection. Moreover, the limited sensitivity for some analytes in earlier assays may have hampered the reliable detection of mild cases. Therefore, we aimed to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay that allows the simultaneous and sensitive detection of an extended range of purine and pyrimidine biomarkers in urine. METHODS: The assay was developed and validated using LC-MS/MS and clinically tested by analyzing ERNDIM Diagnostic Proficiency Testing (DPT) samples and further specimens from patients with various purine and pyrimidine disorders. RESULTS: Reliable determination of 27 analytes including SAICAr, AICAr, beta-ureidoisobutyric acid, 2,8-dihydroxyadenine and orotidine was achieved in urine following a simple sample preparation. The method clearly distinguished pathological and normal samples and differentiated between purine and pyrimidine defects in all clinical specimens. CONCLUSIONS: A LC-MS/MS assay allowing the simultaneous, sensitive and reliable diagnosis of an extended range of purine and pyrimidine disorders has been developed. The validated method has successfully been tested using ERNDIM Diagnostic Proficiency Testing (DPT) samples and further clinical specimens from patients with various purine and pyrimidine disorders. Sample preparation is simple and assay duration is short, facilitating an easier inclusion of the assay into the diagnostic procedures.


Assuntos
Cromatografia Líquida/métodos , Erros Inatos do Metabolismo da Purina-Pirimidina/diagnóstico , Erros Inatos do Metabolismo da Purina-Pirimidina/urina , Espectrometria de Massas em Tandem/métodos , Adenina/análogos & derivados , Adenina/urina , Adolescente , Adulto , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/urina , Biomarcadores/urina , Criança , Pré-Escolar , Cromatografia Líquida/normas , Cromatografia Líquida/estatística & dados numéricos , Feminino , Humanos , Lactente , Masculino , Controle de Qualidade , Valores de Referência , Ribonucleotídeos/urina , Espectrometria de Massas em Tandem/normas , Espectrometria de Massas em Tandem/estatística & dados numéricos , Ureia/análogos & derivados , Ureia/urina , Uridina/análogos & derivados , Uridina/urina
14.
Hum Exp Toxicol ; 38(5): 588-597, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30744402

RESUMO

OBJECTIVE: In the present study, the protective effect of Roflumilast (ROF, a selective phosphodiesterase (PDE-4) inhibitor) was investigated against cadmium (Cd)-induced nephrotoxicity in rats. METHODS: A total of 24 rats were selected and randomly divided into four groups ( n = 6). Group 1 served as the control; groups 2-4 administered with CdCl2 (3 mg/kg, i.p.) for 7 days; groups 3 and 4 were co-administered with ROF in doses of 0.5 and 1.5 mg/kg, orally for 7 consecutive days. Nephrotoxicity was evaluated by measuring urine volume, urea and creatinine levels in urine and serum. Oxidative stress was confirmed by measuring malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) levels in kidney tissue followed by histopathological studies. RESULTS: CdCl2 administration results in a significant ( p < 0.01) decrease in urine volume, urea, and creatinine levels in urine, as well as GSH, SOD, and CAT levels in renal tissue. In addition, Cd also produced significantly increased ( p < 0.01) urea and creatinine levels in serum and TBARS levels in renal tissues. Rats treated with ROF significantly ( p < 0.01) restore the altered levels of kidney injury markers, nonenzymatic antioxidant, as well as depleted enzymes in dose-dependent manner. An increased expression of NF-κB p65 and decreased expression of GST and NQO1 in the Cd only treated group were significantly reversed by high dose of ROF (1.5 mg/kg). Histopathological changes were also ameliorated by ROF administration in Cd-treated groups. CONCLUSION: In conclusion, ROF treatment showed protective effect against renal damage and increased oxidative stress induced by Cd administration.


Assuntos
Aminopiridinas/uso terapêutico , Benzamidas/uso terapêutico , Cloreto de Cádmio/toxicidade , Nefropatias/induzido quimicamente , Nefropatias/tratamento farmacológico , Rim/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/uso terapêutico , Aminopiridinas/farmacologia , Animais , Benzamidas/farmacologia , Catalase/metabolismo , Creatinina/sangue , Creatinina/urina , Ciclopropanos/farmacologia , Ciclopropanos/uso terapêutico , Glutationa/metabolismo , Rim/metabolismo , Rim/patologia , Nefropatias/metabolismo , Nefropatias/patologia , Masculino , NAD(P)H Desidrogenase (Quinona)/metabolismo , NF-kappa B/metabolismo , Inibidores da Fosfodiesterase 4/farmacologia , Ratos Wistar , Superóxido Dismutase/metabolismo , Ureia/sangue , Ureia/urina
15.
Nutrients ; 11(2)2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30717308

RESUMO

Our aim was to assess the validity of the brief-type self-administered diet history questionnaire (BDHQ15y) to estimate the protein intake in 248 Japanese secondary school students (mean age = 14.2 years), using urinary biomarkers as references. Participants provided three samples of overnight urine for measurement of urea nitrogen and creatinine levels, underwent anthropometric measurements, and answered the questionnaires. Additionally, 58 students provided 24-h urine specimens. A significant correlation was observed between excretion of urea nitrogen in overnight and 24-h urine specimens (ρ = 0.527; p < 0.001), with biases ≤5.8%. The mean daily protein intake estimated from urinary biomarkers was 76.4 ± 20.4 g/d in males and 65.4 ± 16.9 g/d in females, and the mean protein intake estimated from the BDHQ15y (PRTbdhq) was 89.3 ± 33.7 g/d in males and 79.6 ± 24.6 g/d in females. Crude and energy-adjusted coefficients of correlation between PRTbdhq and protein intake estimated from urinary biomarkers were 0.205 (p = 0.001; 0.247 for males and 0.124 for females), and 0.204 (p = 0.001; 0.302 for males and 0.109 for females), respectively. The BDHQ15y is a low-cost tool to assess protein intake of a large population, instead of a weakness of overestimation.


Assuntos
Dieta/estatística & dados numéricos , Proteínas na Dieta/análise , Ingestão de Alimentos/fisiologia , Nitrogênio/urina , Ureia/urina , Adolescente , Inquéritos sobre Dietas , Feminino , Humanos , Masculino , Modelos Estatísticos , Inquéritos e Questionários
16.
Nanotechnology ; 30(14): 145502, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30641495

RESUMO

A back-gate-field-effect-transistor (BG-FET) has been developed to selectively detect ammonia and urea. The BG-FET was prepared on a p-type Si substrate with an n-type channel of CdS-TiO2 nanocomposite and poly-methyl methacrylate film as dielectric layer. The reusability of the sensor was ensured by putting it as a cover to a chamber where samples were detected. The BG-FET showed an increase in drain current with the increase in ammonia release from chamber because higher numbers of charge carriers were created when ammonia adsorped on CdS-TiO2 nanostructures. Control experiments suggested that the variation in current-to-voltage response of BG-FET could also be calibrated to measure the activity of a host of other hazardous gases. The lowest concentration of ammonia detected was ∼0.85 ppm with a response time of 30 s at a gate voltage of 0.5 V or less, which were superior than available field effect transistors ammonia sensors. Addition of urease in urine liberated ammonia equivalent to urea content in urine, which could be detected by the proposed BGFET. The urea-urease enzyme catalysis reaction made the sensor specific in detecting the biomarker. The accuracy, sensitivity, and reusability of the device was found to be suitable to develop a point-of-care testing device for ammonia and urea detection.


Assuntos
Amônia/urina , Técnicas Biossensoriais/instrumentação , Eletroquímica/instrumentação , Ureia/urina , Compostos de Cádmio/química , Catálise , Desenho de Equipamento , Reutilização de Equipamento , Humanos , Nanoestruturas/química , Sistemas Automatizados de Assistência Junto ao Leito , Sulfatos/química , Titânio/química , Transistores Eletrônicos
17.
Scand J Clin Lab Invest ; 79(1-2): 86-90, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30614738

RESUMO

Guidelines state that patients undergoing isotope glomerular filtration rate (GFR) tests should maintain adequate hydration, but pragmatically these tests can coincide with procedures requiring the patient not to eat or drink ('nil-by-mouth') for up to 12 hours beforehand. This study investigated the impact of a 12-hour nil-by-mouth regime on GFR measurement. Twelve healthy volunteers were recruited from our institution. Exclusion criteria included diabetes mellitus, being under 18 years of age and pregnancy. Isotope GFR measurements were carried out on these volunteers twice. One of the tests adhered strictly to the British Nuclear Medicine Society (BNMS) guidelines for GFR measurement and the other test was carried out after the volunteers had refrained from eating or drinking anything for 12 hours. The order of these tests was randomly assigned. The results show that after a nil-by-mouth regime, participants' average absolute GFR fell from 108 ml/min to 97 ml/min (p < .01), while normalised GFR fell from 97 ml/min/1.73 m2 to 88 ml/min/1.73m2 (p < .01). Serum creatinine rose from 68 mmol/L to 73 mmol/L (p < .05). There were no changes in blood pressure, serum hydration markers or bio-impedance measured fluid status. Urine analysis showed statistically significant increases in urea, creatinine and osmolality levels after the nil-by-mouth regime. The results highlight the importance of following current guidelines recommending fluid intake during the procedure. Practitioners should consider what other outpatient appointments are being scheduled concurrently with a GFR test.


Assuntos
Testes Diagnósticos de Rotina/métodos , Taxa de Filtração Glomerular/fisiologia , Renografia por Radioisótopo/métodos , Equilíbrio Hidroeletrolítico/fisiologia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Creatinina/sangue , Creatinina/urina , Desidratação/sangue , Testes Diagnósticos de Rotina/ética , Jejum/sangue , Feminino , Voluntários Saudáveis , Humanos , Masculino , Guias de Prática Clínica como Assunto , Renografia por Radioisótopo/ética , Ureia/urina
19.
Nefrologia ; 39(2): 124-132, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30236553

RESUMO

This review discusses the diagnostic value of urinary parameters in the setting of advanced chronic kidney disease and we present the key concepts that summarise the suggestions of the manuscript. URINARY VOLUME: The amount of fluid intake may be a non-established risk factor for CKD. For these patients, a urinary output ≥2-3 l/day is a reasonable proposal. This recommendation is not applicable to patients with cardiorenal syndrome or fluid overload risk. NA: This determination is very useful to monitor salt intake. Reducing urinary Na<120 mEq/day (≅salt intake≤5-6g) is a reasonable objective. URINARY UREA NITROGEN (UUN): This parameter is useful to estimate protein intake (Maroni BJ equation). A protein intake between 48-72g (0.8-0.9g/kg/day according to weight) is equivalent to UUN 7-10g/day approximately. ACID LOAD AND POTASSIUM: Acid load reduction may be an additional strategy in the nutritional management of this population. It may be estimated indirectly from a diet survey or by measuring the elimination of UUN and Kur. The limits of this recommendation have not been established, but we propose a cautious and prudent diet of fruit and vegetables. PHOSPHORUS: There is a significant positive correlation between phosphorus and protein, both in dietary records and urine elimination. Based on this information, we suggest a urinary P excretion<800mg/day or<600mg/day for patients with GFR<25ml/min or<15ml/min, respectively. CONCLUSION: Urinary parameters provide sensitive and useful knowledge for clinical practice, provide information about the dietary habits of patients and the adherence to our recommendations.


Assuntos
Insuficiência Renal Crônica/urina , Ácidos , Cálcio/urina , Síndrome Cardiorrenal/urina , Creatinina/urina , Proteínas na Dieta/administração & dosagem , Proteínas na Dieta/urina , Diurese , Ingestão de Líquidos , Frutas , Humanos , Nitrogênio/urina , Concentração Osmolar , Fósforo/administração & dosagem , Fósforo/urina , Potássio/administração & dosagem , Potássio/urina , Guias de Prática Clínica como Assunto , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/fisiopatologia , Sódio/urina , Cloreto de Sódio na Dieta/administração & dosagem , Ureia/urina , Verduras
20.
J Dairy Sci ; 102(2): 1601-1607, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30471912

RESUMO

Our objectives were to assess the relationships between milk urea N (MUN), serum urea N (SUN), urine N (UN), and urinary urea N (UUN) in late-lactation cows fed N-limiting diets and compare these relationships with those previously established. Data were from a pen-based study in which 128 Holstein cows had been assigned to 1 of 16 pens in a randomized complete block design to assess the effects of diets containing 16.2, 14.4, 13.1, and 11.8% crude protein (CP, dry matter basis) during a 12-wk period. At least half of the cows in each pen were randomly selected to collect pen-level samples of serum and urine in wk 3, 7, and 11, when wk in lactation averaged 35, 39, and 43, respectively. A mixed model was developed to study the relationship of MUN with SUN, UN, and UUN. Week of lactation did not affect the relation between MUN and SUN across dietary treatments. However, we found a week × MUN interaction, suggesting that between wk 35 and 43 of lactation, UN excretion decreased from 89 to 73 g/d (-17 g/d) when MUN was 6.0 mg/dL (11.8% dietary CP) but increased from 142 to 149 g/d (+7 g/d) when MUN was 13.3 mg/dL (16.2% dietary CP). These effects were essentially due to changes in UUN excretion, which declined from 54 to 37 g/d (-17 g/d) and increased from 112 to 117 g/d (+5 g/d) when MUN was 6.0 and 13.3 mg/dL, respectively. When MUN was 11.2 mg/dL (15% dietary CP), UN and UUN excretions remained constant over time. Based on root mean squared prediction error and the concordance correlation coefficient, these data did not conform to most previously published prediction equations because of both mean and slope biases. The discrepancy could have resulted from difference in study design (cow vs. pen as experimental unit), dietary treatments (energy vs. N-limiting diets), frequency of measurement and duration of adaptation period (single measurement after 1 to 3 wk of adaptation vs. repeated measurements over a 12-wk period), method for determining urine volume (total collection vs. spot sampling), and the assay used to measure MUN. However, our data captured changes in kidney physiology that warrant further studies of long-term renal adaptation to N-limiting diets.


Assuntos
Bovinos/metabolismo , Dieta/veterinária , Leite/química , Nitrogênio/metabolismo , Animais , Nitrogênio da Ureia Sanguínea , Bovinos/urina , Feminino , Lactação , Nitrogênio/urina , Ureia/análise , Ureia/urina
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