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1.
J Vet Diagn Invest ; 32(1): 36-43, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31876254

RESUMO

Urine specific gravity (USG), which is usually measured by refractometry, is an important indicator of renal concentrating ability. Few studies have evaluated refractometers with separate scales for canine and feline urine. Variables such as protein content or storage time may influence the USG. We compared the effects of measuring USG with a refractometer with single or separate scales for canine and feline urine, investigated inter- and intra-observer variability, and measured agreement between whole urine and supernatant. We evaluated the correlation between USG and osmolality, the influence of urinary protein on USG and osmolality, and the impact of storage time up to 6 mo. We examined 252 canine and 126 feline samples. Bland-Altman analysis revealed higher USG values of the single-scale refractometer than the dual-scale refractometer, with a mean difference (bias) of < 0.001 for canine and 0.003 for feline specimens. Inter- and intra-observer variability were acceptable. Good agreement was shown between USG of whole urine and supernatant. Correlations between USG and osmolality were excellent (0.98-0.99, p < 0.001). Proteinuria up to 1 g/L had no major impact on USG or osmolality. Storage time had no significant effect on USG. The difference between the refractometers is clinically irrelevant, and the use of a refractometer with separate feline and canine scales is unnecessary. Whole urine and supernatant stored up to 6 mo can both be used for USG measurement. The influence of proteinuria <1 g/L on USG and osmolality is negligible.


Assuntos
Gatos/urina , Cães/urina , Refratometria/veterinária , Urinálise/veterinária , Animais , Concentração Osmolar , Refratometria/instrumentação , Gravidade Específica , Urinálise/instrumentação
2.
Pediatrics ; 144(5)2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31578222

RESUMO

BACKGROUND: A recent study in young infants found that different cutoffs maximized the accuracy of the urine white blood cell count in dilute versus concentrated urine samples. We aimed to confirm this finding and to determine its impact on clinical care. METHODS: We conducted a retrospective analysis of data gathered on consecutive children <24 months of age with visits to the emergency department during a 5-year period. We evaluated the accuracy of screening tests for urinary tract infection (UTI) in dilute and concentrated urine samples. We also calculated the number of children who would have been treated differently in a hypothetical cohort of 1000 children presenting with fever had urine specific gravity (SG) been taken into consideration. RESULTS: We included 10 078 children. The ability to rule in UTI (as measured by the positive likelihood ratio [LR]) was similar in dilute and concentrated urine for the leukocyte esterase test (11.76 vs 10.71, respectively). The positive LR for urine white blood cell count per high-powered field was higher in dilute urine (9.83 vs 6.12). In contrast, the positive LR for the nitrite test was lower in dilute urine (20.54 vs 47.44). Despite these differences, we found little change in the number of children treated with antibiotics in predictive models that took urine SG into consideration. CONCLUSIONS: Although we found that urine SG influences the accuracy of some components of the urinalysis, its inclusion in the decision-making process had negligible effect on the clinical care of children with UTI.


Assuntos
Gravidade Específica , Urinálise , Infecções Urinárias/diagnóstico , Urina/química , Bacteriúria/diagnóstico , Feminino , Humanos , Lactente , Contagem de Leucócitos , Funções Verossimilhança , Masculino , Piúria/diagnóstico , Estudos Retrospectivos , Urinálise/métodos
3.
Am J Vet Res ; 80(10): 907-911, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31556718

RESUMO

OBJECTIVE: To evaluate effects of the addition of glucose to dog and cat urine on urine specific gravity (USG) and determine whether glucosuria affects assessment of renal concentrating ability. SAMPLE: Urine samples from 102 dogs and 59 cats. PROCEDURES: Urine for each species was pooled to create samples with various USGs. Glucose was added to an aliquot of each USG pool (final concentration, 2,400 mg/dL), and serial dilutions of the glucose-containing aliquot were created for each pool. The USG then was measured in all samples. The difference in USG attributable to addition of glucose was calculated by subtracting the USG of the unaltered sample from the USG of the sample after the addition of glucose. The relationship between the difference in USG and the USG of the unaltered, undiluted sample was evaluated by the use of linear regression analysis. RESULTS: Addition of glucose to urine samples increased the USG. There was a significant relationship between USG of the undiluted sample and the difference in USG when glucose was added to obtain concentrations of 300, 600, 1,200, and 2,400 mg/dL in canine urine and concentrations of 600, 1,200, and 2,400 mg/dL in feline urine. The more concentrated the urine before the addition of glucose, the less change there was in the USG. Changes in USG attributable to addition of glucose were not clinically important. CONCLUSIONS AND CLINICAL RELEVANCE: Substantial glucosuria resulted in minimal alterations in specific gravity of canine and feline urine samples. Thus, USG can be used to assess renal concentrating ability even in samples with glucosuria.


Assuntos
Doenças do Gato/urina , Doenças do Cão/urina , Glucose/química , Glicosúria/veterinária , Urina/química , Animais , Gatos , Cães , Glicosúria/urina , Modelos Lineares , Refratometria/veterinária , Análise de Regressão , Gravidade Específica , Urinálise/veterinária
4.
J Vet Intern Med ; 33(5): 2133-2137, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31423644

RESUMO

BACKGROUND: Urine specific gravity (USG) is an integral part of the urinalysis and a key component of many clinical decisions, and fluctuations in USG have the potential to impact case management. OBJECTIVES: To determine the intraindividual variability of first morning USG results in healthy dogs. ANIMALS: One hundred three healthy client-owned dogs. METHODS: Dogs were deemed healthy based on clinical history and physical examination findings. Repeated USG measurements were performed over the course of 2 weeks. Three urine samples were collected each week for a total of 6 samples per dog. Sample collection was distributed evenly throughout the week. Urine samples were acquired immediately upon waking and before any ingestion of liquids, food, or exertion of physical activity in the dogs. All measurements were made using the same Misco digital refractometer. RESULTS: Intraindividual USG was variable over the course of the study. The mean difference between the minimum and maximum USG for each dog was 0.015 (SD, 0.007). The within-week difference between the minimum and maximum USG was less than over the complete 2-week study (0.009 [SD 0.006] for week 1 and 0.010 [SD 0.007] for week 2). The mean coefficient of variance across all 6 time points was 15.4% (SD 8.97%). CONCLUSIONS AND CLINICAL IMPORTANCE: Clinically important variation occurs in USG in healthy animals and might impact clinical decision-making when diagnostic cutoff points are utilized. Clinicians should be aware of inherent variability in this clinical variable when analyzing results.


Assuntos
Cães/urina , Gravidade Específica , Urina/química , Animais , Feminino , Masculino , Refratometria/veterinária , Urinálise/veterinária
5.
Curr Environ Health Rep ; 6(3): 188-199, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31372861

RESUMO

BACKGROUND: Urinary biomonitoring is widely used to assess environmental chemical exposure; however, a critical gap exists in whether and how to correct for the physiological variation in water content of spot urine samples. OBJECTIVE: The aim of this systematic review is to summarize the available evidence comparing the performance of urinary concentration correction methods used to determine urinary levels of arsenic, cadmium, and mercury. METHODS: We searched PubMed/MEDLINE, Embase, LILIAC, Web of Science, and TOXNET up to Sept. 5, 2017 for articles evaluating urinary concentration correction methods (e.g., urine creatinine [U-Cre], specific gravity [U-SG], osmolality [U-Osm]) compared to 24-h or timed urine specimens for levels of arsenic, cadmium, and mercury. Data on study design, methods of urine collection, and the performance of selected correction methods were extracted. RESULTS: A total of 10 papers met the inclusion criteria. Two papers evaluated the performance of urinary concentration correction methods for arsenic, four for cadmium, three for mercury, and one for multiple metals. The median sample size for arsenic was 105, for cadmium 107, and for mercury 35. The studies were highly heterogeneous in population selection, urine collection, urine quality control, statistical comparison among selected correction methods, and presentation of the results. The median (range) of correlation coefficients comparing each corrected values with corresponding levels of timed urine specimens are 0.74 (0.17-0.92) for un-correction (n = 13), 0.82 (0.52-0.98) for U-Cre (n = 13), and 0.75 (0.28-0.98) (n = 12) for U-SG. CONCLUSION: Findings from limited evidence support that urine creatinine and urine-specific gravity corrections remain practical approaches to correct metal concentrations for urine dilution as compared to 24-h or 12-h urine samples. Further studies with larger sample sizes are needed to clarify this fundamental issue of environmental biomonitoring using spot urine samples in both general and priority populations.


Assuntos
Arsênico/urina , Cádmio/urina , Exposição Ambiental/análise , Poluentes Ambientais/urina , Mercúrio/urina , Biomarcadores/urina , Feminino , Humanos , Gravidade Específica , Urinálise/métodos
6.
Brain Behav Evol ; 93(4): 182-195, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31437837

RESUMO

Body size correlates with most structural and functional components of an organism's phenotype - brain size being a prime example of allometric scaling with animal size. Therefore, comparative studies of brain evolution in vertebrates rely on controlling for the scaling effects of body size variation on brain size variation by calculating brain weight/body weight ratios. Differences in the brain size-body size relationship between taxa are usually interpreted as differences in selection acting on the brain or its components, while selection pressures acting on body size, which are among the most prevalent in nature, are rarely acknowledged, leading to conflicting and confusing conclusions. We address these problems by comparing brain-body relationships from across >1,000 species of birds and non-avian reptiles. Relative brain size in birds is often assumed to be 10 times larger than in reptiles of similar body size. We examine how differences in the specific gravity of body tissues and in body design (e.g., presence/absence of a tail or a dense shell) between these two groups can affect estimates of relative brain size. Using phylogenetic comparative analyses, we show that the gap in relative brain size between birds and reptiles has been grossly exaggerated. Our results highlight the need to take into account differences between taxa arising from selection pressures affecting body size and design, and call into question the widespread misconception that reptile brains are small and incapable of supporting sophisticated behavior and cognition.


Assuntos
Evolução Biológica , Aves/anatomia & histologia , Tamanho Corporal , Encéfalo/anatomia & histologia , Répteis/anatomia & histologia , Animais , Tamanho do Órgão , Gravidade Específica
7.
PLoS One ; 14(8): e0220724, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31381592

RESUMO

The purpose of this study was to examine the effect of storage temperature, duration, and storage vessel seal on 24 h urinary hydration markers. Twenty-one males (n = 8) and females (n = 13) (mean±SD; age, 24±5 y; body mass, 68.9±24.2 kg; height, 160.2±32.1 cm) without a history of renal disease or currently taking any medications or supplements known to affect the accuracy of urinary hydration markers were enrolled in this study. Participants provided a 24 h urine sample in a clean container with each urine sample being separate into four separate containers, two in each of the following temperatures: 7°C and 22°C. One specimen container at each temperature was either sealed using the manufacturers cap (single sealed) or the manufacturers cap plus laboratory wrapping film (double sealed). Each sample was analyzed after 1, 2, 3, 7 and 10 days. Urine samples were assessed for urine osmolality (UOSMO), urine specific gravity (USG) and urine color (UCOL). UOSMO was stable at 7°C for two days (mean difference [95% CI]; +1 mmol·kg-1 [0+3], p>0.05) and three days (+1 mmol·kg-1 [0, +3], p>0.05) for single sealed and double sealed containers, respectively. USG measures were stable for singled sealed and double sealed for up to ten days when stored at 22°C. UCOL measures were maintained for up to three days in all storage methods (p>0.05). In conclusion, if immediate analysis is unavailable, such as in the case of field based or longitudinal research, it is recommended that 24 h urine samples are stored in a refrigerated environment and hydration markers (UOSMO and UCOL) be assessed within 48 h.


Assuntos
Desidratação/urina , Urinálise/métodos , Adolescente , Adulto , Biomarcadores/urina , Feminino , Humanos , Masculino , Concentração Osmolar , Gravidade Específica , Temperatura , Coleta de Urina/métodos , Adulto Jovem
8.
Medicina (Kaunas) ; 55(8)2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31349723

RESUMO

Background and objectives: Abdominal aortic aneurysm (AAA) growth is unpredictable after the endovascular aneurysm repair (EVAR). Continuing aortic wall degradation and weakening due to hypoxia may have a role in post-EVAR aneurysm sac growth. We aimed to assess the association of aortic wall density on computed tomography angiography (CTA) with aneurysm growth following EVAR. Materials and Methods: A total of 78 patients were included in the study. The control group consisted of 39 randomly assigned patients without aortic pathology. Post-EVAR aneurysm sac volumes on CTA were measured twice during the follow-up period to estimate aneurysm sac behavior. A maximum AAA sac diameter, aortic wall and lumen densities in Hounsfield units (HU) on CTA were measured. A relative aortic wall density (the ratio of aortic wall to lumen densities) was calculated. A statistical data analysis was performed using standard methods. Results: An increase in the AAA sac volume was observed in 12 (30.8%) cases. Median relative aortic wall density on CTA scores in both the patient and the control group at the level of the diaphragm were similar: 0.15 (interquartile range (IQR), 0.11-0.18) and 0.16 (IQR 0.11-0.18), p = 0.5378, respectively. The median (IQR) relative aortic wall density score at the level of the maximum AAA diameter in the patient group was lower than at the level below renal arteries in the control group: 0.10 (0.07-0.12) and 0.17 (0.12-0.23), p < 0.0001, respectively. The median (IQR) relative growing AAA sac wall density score was lower than a relative stable/shrinking AAA sac wall density score: 0.09 (0.06-0.10) and 0.11 (0.09-0.13), p = 0.0096, respectively. Conclusions: A lower aortic aneurysm wall density on CTA may be associated with AAA growth after EVAR.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Gravidade Específica , Procedimentos Cirúrgicos Vasculares/normas , Idoso , Aorta Abdominal/fisiopatologia , Aorta Abdominal/cirurgia , Aneurisma da Aorta Abdominal/fisiopatologia , Estudos de Coortes , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Tomografia Computadorizada/estatística & dados numéricos , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/métodos , Procedimentos Cirúrgicos Vasculares/estatística & dados numéricos
9.
Clin Biochem ; 71: 77-80, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31299318

RESUMO

Tetrabromphenol blue dye based methods are used to detect proteinuria using urinalysis dipsticks. Manufacturers have claimed that alkalinity leads to false positive proteinuria, and that high specific gravity leads to false negative protein results. However, published reports describing this phenomenon remain equivocal. This study aimed to determine whether pH and/or specific gravity affect protein detection in patient urine using three different tetrabromophenol blue dye-based dipsticks. Patient urine pools were divided into individual aliquots with varied pH or specific gravity, and measured for protein in triplicate using iChem 10SG, iChem Velocity, and Multistix 8SG dipsticks. The pH experiment involved progressive alkalinization of urine aliquots with either 1M NaOH, Na2CO3, or NaHCO3; pH was recorded by electrode. The specific gravity experiment involved mixing aliquots with NaCl and spiking with human albumin. Urine electrolytes and total CO2 were measured (Roche cobas 8000). Fresh patient urines (N = 35) were analyzed for physiological urine pH and total CO2. Urine protein results were not affected by NaOH alkalinization up to pH 10.9. False positive protein occurred at pH 9.9 and >97 mmol/L total CO2 (Na2CO3 alkalization; P < .05). Moreover, false positive protein occurred at pH 7.6 when total CO2 exceeded 137 mmol/L (NaHCO3 alkalization; P < .05). Fresh patient urines did not exceed pH 8.5 or 86 mmol/L total CO2. NaCl elevated specific gravity and caused false negative protein detection when urine ionic strength was >1100 mmol/L (P < .05). Tetrabromphenol blue dipsticks provide robust detection of proteinuria when human urine is within physiological pH, total CO2 and ionic strength.


Assuntos
Concentração de Íons de Hidrogênio , Proteinúria/metabolismo , Fitas Reagentes , Gravidade Específica , Urina/química , Artefatos
10.
BMC Vet Res ; 15(1): 242, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300054

RESUMO

BACKGROUND: Urinalysis is a critical diagnostic test which is performed in routine veterinary medicine practice. In this diagnostic test, semiquantitative measurement of urine biochemical substances is carried out using urinary dipstick. In the current study, we evaluated the diagnostic performance of human urinary dipsticks to estimate pH, specific gravity (SpG), and protein in 80 urine specimens collected from horses. These parameters were measured using two commercial human dipsticks (KP and MN in abbreviation) and quantitative reference methods. The reference methods for pH, SpG, and protein were pH meter, handheld refractometer, and pyrogallol red method, respectively. The correlation between the semiquantitative dipstick analysis and quantitative reference methods was determined using Spearman's rank correlation coefficient. RESULTS: In general, our results revealed that the both human urinary dipsticks are unreliable tests for urinary pH, SpG, and protein content in horses. The analysis indicated that there was a poor correlation between the urine dipsticks and reference method (KP: rS = 0.534 and MN: rs = 0.485, Ps < 0.001) for protein. Additionally, there was a weak correlation between the results of pH measured using the urine dipsticks and reference method (KP: rS = 0.445 and MN: rs = 0.370, Ps < 0.001). Similar findings were obtained for SpG (KP: rS = 0.285, MN: rs = 0.338, Ps < 0.001). The estimation of proteinuria using the human dipsticks in horses lacked specificity, as many false positive protein results were obtained. CONCLUSION: We observed that the human commercial urinary dipsticks used in this study were not reliable to correctly estimate urine protein, SpG, and pH in horses.


Assuntos
Cavalos/urina , Fitas Reagentes/normas , Urinálise/veterinária , Animais , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Proteinúria/diagnóstico , Proteinúria/veterinária , Sensibilidade e Especificidade , Gravidade Específica , Urinálise/instrumentação , Urinálise/métodos
11.
Drug Test Anal ; 11(9): 1302-1307, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31243893

RESUMO

We developed and evaluated the properties of in-house urine reference materials for the verification of laboratory refractometers, which are frequently used in clinical chemistry and doping testing laboratories. Urine was gathered from 26 healthy volunteers (16 male 30 ± 5 years old and 10 female 29 ± 4 years old), from which two urine batches were obtained: one with a low specific gravity (1.012± 0.003) and the other with a high specific gravity (1.027 ± 0.003). Homogeneity studies were conducted over 20 consecutive days. For short-term stability studies, aliquots of both urine batches were stored at -20 ± 2°C; 3 ± 2°C; 20 ± 2°C; 45 ± 2°C for 0, 2, 7, 14 and 35 days, under both light and dark conditions. Similarly, another study was conducted to measure the long-term stability of urine at -20 ± 2°C, over a 24-month evaluation period. Our data showed that the urine was homogeneous and stable at -20 ± 2°C, 3 ± 2°C, 20 ± 2°C, and 45 ± 2°C under both light and dark conditions. In all cases, the urine was evaluated by specific gravity and no statistically significant differences (p ≤ 0.05) were recorded. Additionally, a proficiency test was conducted in collaboration with 15 ISO/IEC 17025 accredited laboratories, and z-scores and performance factors were evaluated. These data indicate that this material could be used for the verification of refractometers.


Assuntos
Refratometria/métodos , Urinálise/métodos , Urina/química , Adulto , Feminino , Humanos , Masculino , Controle de Qualidade , Padrões de Referência , Refratometria/normas , Gravidade Específica , Urinálise/normas
12.
Environ Int ; 130: 104721, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31207477

RESUMO

Spot urinary concentrations of environmental exposure biomarkers require correction for dilution. There is no consensus on the most appropriate method, with creatinine used by default despite lacking theoretical robustness. We comparatively assessed the efficacy of creatinine; specific gravity (SG); osmolality and modifications of all three for dilution correcting urinary arsenic. For 202 participants with urinary arsenic, creatinine, osmolality and SG measurements paired to drinking water As, we compared the performance corrections against two independent criteria: primarily, (A) correlations of corrected urinary As and the dilution measurements used to correct them - weak correlations indicating good performance and (B) correlations of corrected urinary As and drinking water As - strong correlations indicating good performance. More than a third of variation in spot urinary As concentrations was attributable to dilution. Conventional SG and osmolality correction removed significant dilution variation from As concentrations, whereas conventional creatinine over-corrected, and modifications of all three removed measurable dilution variation. Modified creatinine and both methods of SG and osmolality generated stronger correlations of urinary and drinking water As concentrations than conventional creatinine, which gave weaker correlations than uncorrected values. A disparity in optima between performance criteria was observed, with much smaller improvements possible for Criterion B relative to A. Conventional corrections - particularly creatinine - limit the utility spot urine samples, whereas a modified technique outlined here may allow substantial improvement and can be readily retrospectively applied to existing datasets. More studies are needed to optimize urinary dilution correction methods. Covariates of urinary dilution measurements still warrant consideration.


Assuntos
Arsênico/urina , Exposição Ambiental/análise , Urinálise/métodos , Biomarcadores , Creatinina , Água Potável/química , Humanos , Gravidade Específica , Reino Unido
13.
Zhonghua Yu Fang Yi Xue Za Zhi ; 53(4): 355-359, 2019 Apr 06.
Artigo em Chinês | MEDLINE | ID: mdl-30982267

RESUMO

Objectives: To investigate the total fluids intake, volume of urine and hydration status among college students from Hebei Province in spring. Methods: In March 2017, the subjects were recruited in a college in Baoding, Hebei Province. 156 students completed the investigation. Total drinking fluids was assessed by 7-day 24-hour fluid intake questionnaire, with a quantitative tool. The water from food was assessed by the duplicate portion method. The urine samples of 24-hour was collected for 3 consecutive days, and the volume, osmolality, pH and specific gravity of urine were measured. Hydration status was grouped to three types according to the urine osmolality (mOsm/kg), namely, optimal hydration (urine osmolality ≤500), middle hydration (500< urine osmolality ≥800) and dehydration (urine osmolality >800), and the differences among subjects in different genders and hydration statuses were compared. Results: The age of all subjects was (19.8±1.1) years old, including 80 male students. The median amounts of total fluids intake, total drinking fluids, water from food and urine volume were 2 324, 1 135, 1 174 and 1 279 ml/d, respectively. The volume of urine among males was 1 272 ml/d, which was not significantly different from that of females (1 304 ml/d) (P>0.05). The osmolality and specific gravity of urine among males were 688 mOsm/kg and 1.017, which were higher than those of females (493 mOsm/kg, 1.014) (P<0.05). But the pH of males was 6.6±0.3, which was lower than that of females (6.7±0.3) (P<0.05). Only 37.2% (n=58) of college students were in optimal hydration status. The median of the amount of total drinking fluids among subjects in optimal hydration status was 301, 448 ml/d higher than that in middle hydration status and dehydration, respectively (P<0.05). The proportion of females in optimal hydration status was 51.3% (n=39), which was higher than that of males 23.8% (n=19) (P<0.05). Conclusion: Large proportion of college students in Hebei had lower total drinking fluids than the recommended intake of China, and the volume of urine was equal to the amount of total drinking fluids among the college students. Only 37.2% of college students were in optimal hydration status, and the proportion of female college students in optimal hydration status was larger than that of males.


Assuntos
Desidratação/urina , Ingestão de Líquidos , Estado de Hidratação do Organismo , Urinálise/métodos , Adolescente , Grupo com Ancestrais do Continente Asiático , Biomarcadores/urina , China , Feminino , Humanos , Masculino , Concentração Osmolar , Gravidade Específica , Adulto Jovem
14.
Int Arch Occup Environ Health ; 92(7): 977-990, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30997573

RESUMO

OBJECTIVE: Agricultural workers worldwide exposed to heat stress could be at the risk of kidney injury, which could lead to chronic kidney disease of an unknown origin (CKDu). Hydration has been promoted as a key measure to reduce kidney injury. In the presence of a hydration intervention, the incidence of acute kidney injury (AKI) was calculated in a sugarcane worker population in Guatemala and several risk factors were evaluated. METHODS: We measured kidney function at the beginning and end of the work shift at three time points in 517 sugarcane workers. We defined AKI as an increase in serum creatinine of 26.5 µmol/L or 50% or more from the pre-shift value. Associations between AKI and risk factors were examined, including interactions with hydration status. RESULTS: The prevalence of dehydration post-shift (> 1.020 specific gravity) was 11% in February, 9% in March, and 6% in April. Cumulative incidence of AKI was 53% in February, 54% in March, and 51% in April. AKI was associated with increasing post-shift specific gravity, a dehydration marker, (OR 1.24, 95% CI 1.02-1.52) and with lower electrolyte solution intake (OR 0.94, 95% CI 0.89-0.99). CONCLUSIONS: Dehydration and insufficient electrolyte consumption are risk factors for AKI. However even well-hydrated sugarcane workers routinely experience AKI. While hydration is important and protective, there is a need to understand other contributors to risk of AKI and identify prevention strategies with these workers.


Assuntos
Lesão Renal Aguda/prevenção & controle , Fazendeiros , Transtornos de Estresse por Calor/epidemiologia , Exposição Ocupacional/efeitos adversos , Lesão Renal Aguda/etiologia , Adulto , Estudos de Coortes , Creatinina/sangue , Desidratação/epidemiologia , Desidratação/prevenção & controle , Eletrólitos , Guatemala , Humanos , Estudos Longitudinais , Masculino , Prevalência , Estudos Prospectivos , Saccharum , Gravidade Específica
15.
J Vet Intern Med ; 33(3): 1530-1539, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31025445

RESUMO

BACKGROUND: Urine concentration (UC) provides clinically useful information concerning hydration status and renal function of animals. OBJECTIVES: To characterize the clinical performance of urine specific gravity measured by optical refractometry (USG-R ) or Multistix-SG urine reagent dipstick (USG-D ), urine electrical conductivity using an OAKTON Con 6 conductivity handheld meter (UEC ), urine color (UColor ) using a custom-designed 8-point color chart, and urine creatinine concentration (UCreat ) for assessing UC in dairy cattle. ANIMALS: 20 periparturient Holstein-Friesian cows. METHODS: Urine was obtained by perineal stimulation or urethral catheterization and urine osmolality (UOsm , reference method), USG-R , USG-D , UEC , UColor , and UCreat determined. Diagnostic test performance was evaluated using Spearman's rho and logistic regression to determine the area under the receiver operating curve (AUC) and optimal cut point for diagnosing hypohydration (UOsm ≥800 mOsm/kg). P < .05 was considered significant. RESULTS: The best performing test for diagnosing hypohydration was USG-R (AUC = 0.90) at an optimal cut point ≥1.030. The second-best performing test was UEC (AUC = 0.82) at a cut point of ≥23.7 mS/cm, followed by UCreat (AUC = 0.76) at a cut point of ≥95.3 mg/dL, and UColor (AUC = 0.74) at a cut point of ≥4 on an 8-point scale. Urine specific gravity measured by dipstick performed poorly (AUC = 0.63). CONCLUSIONS AND CLINICAL IMPORTANCE: USG-R and UEC provide practical and sufficiently accurate methods for measuring UC in dairy cattle. Urine color had moderate clinical utility as a no-cost cow-side method for assessing UC, whereas dipstick refractometry is not recommended for assessing UC.


Assuntos
Bovinos/urina , Cor , Estado de Hidratação do Organismo , Gravidade Específica , Urinálise/veterinária , Animais , Creatinina/urina , Condutividade Elétrica , Feminino , Testes de Função Renal/veterinária , Sensibilidade e Especificidade , Urinálise/instrumentação , Urinálise/métodos
16.
J Vet Diagn Invest ; 31(3): 426-433, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30943877

RESUMO

Urinalysis is a rapid, simple, inexpensive, and reliable test that documents urine abnormalities reflecting various types of renal, hormonal, or metabolic diseases. Urinalysis could assist proper monitoring of the health of dolphins under human care; however, normal baseline values for dolphin urinalysis have not been reported, to our knowledge. We sampled urine from 193 common bottlenose dolphins ( Tursiops truncatus), living under human care in 24 Caribbean dolphinariums, by voluntary free-catch and analyzed the urine for chemical and microscopic variables using multi-agent dry reagent chemistry dipstick test strips, dedicated pH reagent strips, and unstained sediment slides. Most urine was clear, pale yellow to dark yellow, and had a fishy odor. Dipstick glucose, bilirubin, ketones, and nitrites were negative in all dolphins. The urine pH was acidic ( x¯ ± SD; 5.88 ± 0.58) and specific gravity (SG) was 1.035 ± 0.008. Most animals had 0-2 red blood cells and white blood cells per 40× field, and were negative for proteins. On microscopic sediment, 42.7% of samples had few-to-many squamous epithelial cells; hyaline and epithelial casts were observed only rarely. Crystals were observed in 36.6% of the samples; most were calcium oxalate dihydrate (48.2%) and amorphous urates (42.4%). The values obtained in our study can be used as a reference for health monitoring of dolphins in dolphinariums, and to monitor renal conditions and function in dolphins being rehabilitated or under human care.


Assuntos
Golfinho Nariz-de-Garrafa/urina , Urinálise/veterinária , Animais , Região do Caribe , Humanos , Fitas Reagentes , Gravidade Específica , Urinálise/instrumentação , Urinálise/métodos
17.
Int J Hyg Environ Health ; 222(5): 831-839, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31030889

RESUMO

To document trends in human exposure to environmental pollutants, the German Environmental Specimen Bank (ESB) has been routinely collecting and archiving 24-h urine samples from young adults at four sampling sites in Germany on an annual basis. For the purpose of normalizing measured analyte concentrations, urinary creatinine (UC), specific gravity (SG), conductivity (CON), and total urine volume (UVtot) of 24-h urine samples have also been recorded. These parameters are however susceptible to variation over time, as well as within/among participants and normalization against them can thus affect the interpretation of data regarding exposure to environmental pollutants. To evaluate the influence of normalization against these parameters, we first sought to determine variations of these parameters with regard to differences between sexes and trends over time. We analysed data from 8619 urine samples collected from 1997 to 2016. We observed an inverse relation between UVtot and UC, SG, and CON. We also found differences between sexes for UC, SG and CON, but not UVtot. UC, SG, and CON showed significant decreasing trends over time in both sexes. In contrast, a significant increase of over 30% in UVtot, independent of participant age and BMI, was revealed. This increase in UVtot and the concomitant sample dilution is likely to have an impact on measured analyte concentrations in 24-h urine samples. Hence, normalization of urinary concentrations is warranted when interpreting time trends of human exposure. Next, urinary calcium (Ca2+) concentrations of ESB participants were used to demonstrate the effects of normalization against each of the four urine parameters. From 1997 to 2016, measured Ca2+ concentrations showed a statistically significant but scientifically implausible decrease. Normalization of Ca2+ concentrations against UVtot (by calculating the total daily excretion), UC, or CON, but not SG, eliminated this decrease. Consistent with previous work, Ca2+ concentrations in urine and total daily Ca2+ excretion were higher for males than females. Normalization against UC, SG, or CON, however, attenuated this difference. Thus, to avoid misinterpretation in trend analysis and sex-specific excretion in 24-h urine samples, the calculation of the total daily excretion is recommended.


Assuntos
Monitoramento Biológico/métodos , Monitoramento Ambiental/métodos , Bancos de Espécimes Biológicos , Cálcio/urina , Condutividade Elétrica , Exposição Ambiental/análise , Feminino , Alemanha , Humanos , Masculino , Fatores Sexuais , Gravidade Específica
18.
East Mediterr Health J ; 25(1): 34-39, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30919923

RESUMO

Background: High process temperatures associated with industrial operations augment risk of heat stress and illness, particularly during summer months in the Gulf Region. Lack of hydration and nutrition during day time, during Ramadan can subject workers to even greater risk of heat stress and illness. Aims: To examine the physiological effects of prolonged fasting in thermally challenging conditions. Methods: Longitudinal measurements were carried out on employees during fasting in Ramadan in three departments of an aluminium smelter. After informed consent, physiological parameters were measured at 4-hour intervals. Results: Average heart rate and urine specific gravity increased in the first 4 hours of shift work, while tympanic temperature did not rise significantly. Moreover, in the second 4 hours of shift work, urine specific gravity stabilized compared to the first 4 hours. Conclusions: Robust workplace measures are needed for industries with high process temperatures, located in the Gulf Region, in order to minimize the enhanced risk of heat stress and illness during Ramadan.


Assuntos
Jejum/efeitos adversos , Resposta ao Choque Térmico , Férias e Feriados , Islamismo , Jejum/fisiologia , Frequência Cardíaca , Resposta ao Choque Térmico/fisiologia , Temperatura Alta/efeitos adversos , Humanos , Metalurgia , Doenças Profissionais/etiologia , Omã , Jornada de Trabalho em Turnos/efeitos adversos , Gravidade Específica , Urina/fisiologia
19.
Nutrients ; 11(3)2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30845753

RESUMO

The achievement of adequate hydration status is essential for mental and physical performance and for health in general, especially in children and adolescents. Nevertheless, little is known about hydration status of this population, mainly due to the limited availability of research tools; thus, the objective of the current study was to adapt and validate our hydration status questionnaire in a Spanish adolescent-young population. The questionnaire was validated against important hydration markers: urine colour, urine specific gravity, haemoglobin, haematocrit and total body water and involved 128 subjects aged between 12⁻17 years. Water intake was also estimated through a three-day dietary record and physical activity was assessed through accelerometers. Participants completed the questionnaire twice. Water balance and water intake were correlated with urine specific gravity and with total body water content. Water intake obtained by the questionnaire was correlated with results from the three-day dietary record. The intraclass correlation coefficient indicated moderate concordance between both recordings and the Cronbach's alpha revealed high consistency. The Bland and Altman method indicated that the limits of agreement were acceptable to reveal the reliability of the estimated measures. In conclusion, this is the first time that a questionnaire is valid and reliable to estimate hydration status of adolescent-young populations.


Assuntos
Ingestão de Líquidos , Inquéritos Nutricionais/normas , Estado de Hidratação do Organismo , Acelerometria/estatística & dados numéricos , Adolescente , Água Corporal , Criança , Estudos Transversais , Exercício Físico , Feminino , Humanos , Masculino , Inquéritos Nutricionais/estatística & dados numéricos , Reprodutibilidade dos Testes , Espanha , Gravidade Específica , Estatísticas não Paramétricas
20.
Drug Test Anal ; 11(7): 968-975, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30756523

RESUMO

Variability in urine dilution complicates urine cannabinoid test interpretation. Normalizing urine cannabinoid concentrations to specific gravity (SG) or creatinine was proposed to account for donors' hydration states. In this study, all urine voids were individually collected from eight frequent and eight occasional cannabis users for up to 85 hours after each received on separate occasions 50.6 mg Δ9-tetrahydrocannabinol (THC) by smoking, vaporization, and oral ingestion in a randomized, within-subject, double-blind, double-dummy, placebo-controlled protocol. Each urine void was analyzed for 11 cannabinoids and phase I and II metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS), SG, and creatinine. Normalized urine concentrations were log10 transformed to create normal distributions, and Pearson correlation coefficients determined the degree of association between the two normalization methods. Repeated-measures linear regression determined if the degree of association differed by frequent or occasional cannabis use, or route of administration after adjusting for gender and time since dosing. Of 1880 urine samples examined, only 11-nor-9-carboxy-THC (THCCOOH), THCCOOH-glucuronide, THC-glucuronide, and 11-nor-9-carboxy-Δ9-tetrahydrocannabivarin (THCVCOOH) were greater than the method's limits of quantification (LOQs). Associations between SG- and creatinine-normalized concentrations exceeded 0.90. Repeated-measures regression analysis found small but statistically significant differences in the degree of association between normalization methods for THCCOOH and THCCOOH-glucuronide in frequent vs occasional smokers, and in THCVCOOH and THC-glucuronide by route of administration. For the first time, SG- and creatinine-normalized urine cannabinoid concentrations were evaluated in frequent and occasional cannabis users and following oral, smoked, and inhaled cannabis. Both normalization methods reduced variability, improving the interpretation of urine cannabinoid concentrations and methods were strongly correlated.


Assuntos
Canabinoides/urina , Creatinina/urina , Fumar Maconha/urina , Administração Oral , Adulto , Método Duplo-Cego , Humanos , Pessoa de Meia-Idade , Efeito Placebo , Gravidade Específica , Volatilização , Adulto Jovem
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