specific gravity (SG) and osmolality (Osm) were measured. The ratios of urinary Na to other parameters were calculated, and correlations with total measured 24UNa were identified.RESULTS: Average 24-hr urine volume was 1,403 ± 475 mL, and measured 24UNa was 143.9 ± 42.1 mEq (range, 87.1–239.4 mEq). Measured 24UNa was significantly correlated with urinary Na/UN (r = 0.560, P < 0.01), urinary Na/Osm (r = 0.510, P < 0.01), urinary Na/Cr (r = 0.392, P < 0.01), urinary Na/K (r = 0.290, P < 0.01), 24UNa estimated using Tanaka's equation (r = 0.452, P < 0.01) and the Korean formula (r = 0.414, P < 0.01), age (r = 0.548, P < 0.01), weight (r = 0.497, P < 0.01), and height (r = 0.393, P < 0.01) in all spot urine samples. Estimated 24UNa based on the second-void spot urine of the first day tended to be more closely correlated with measured 24UNa than were estimates from the other spot urine samples. The significant parameters correlated with the second-void urine of the first day were urinary Na/K (r = 0.647, P < 0.01), urinary Na/Cr (r = 0.558, P < 0.05), and estimated 24UNa using Tanaka's equation (r = 0.616, P < 0.05) and the Korean formula (r = 0.588, P < 0.05).CONCLUSIONS: Second-void urine is more reliable than first-void urine for estimating 24UNa. Urinary Na/K in the second-void urine on the first day is significantly correlated with 24UNa. Further studies are needed to establish the most reliable index and the optimal time of urine sampling for predicting 24UNa.]]>
Creatinine ; Humans ; Male ; Meals ; Methods ; Nitrogen ; Osmolar Concentration ; Potassium ; Sodium ; Sodium, Dietary ; Specific Gravity ; Urea ; Urine Specimen Collection

This study aims to explore the change laws of water absorption in Chinese herbal pieces and establish the prediction model of relative density for Chinese medicine compound decoction. Firstly, fitted equations of water absorption and decocting time was established by observing the change laws of water absorption in 36 kinds of Chinese herbal pieces in 12 groups(according to the drug-parts) with decocting time. The r value of the mineral group and other type group was 0.691 2 and 0.663 3, respectively. The r value of the remaining 10 groups was 0.802 2-0.925 4. All P values were less than 0.05(n=21). The formula of the amount of water added was optimized by combining the fitted equations with determined water absorption, and the liquid yield could be controlled in a range of 100%±10%. Secondly, it was determined that the liquid density tester could be used for the rapid determination of relative density of Chinese medicine decoction after methodological study and comparison with the pycnometer method. The linear regression equation between the corrected relative density(y) and extraction ratio(%, x) was built by measuring and analyzing the related parameters such as liquid yield, relative density and extraction ratio in 46 kinds of Chinese herbal pieces. The established equation was y=0.041 3x+1.003 7, r=0.930 9(P <0.01, n=46), with linear range of 1.94%-65.75%. Based on this, the prototype model for predicting relative density of Chinese medicine decoction was established, and the relative densities of 8 Chinese medicine decoctions were within the prediction interval of this model in verification. This study lays a foundation for database construction of Chinese medicine decoction, implementation of personalized decocting mode and rapid quality control of Chinese medicine decoction.
Drugs, Chinese Herbal ; Medicine, Chinese Traditional ; Quality Control ; Specific Gravity ; Water

New technological advances have paved the way for significant progress in automated urinalysis. Quantitative reading of urinary test strips using reflectometry has become possible, while complementary metal oxide semiconductor (CMOS) technology has enhanced analytical sensitivity and shown promise in microalbuminuria testing. Microscopy-based urine particle analysis has greatly progressed over the past decades, enabling high throughput in clinical laboratories. Urinary flow cytometry is an alternative for automated microscopy, and more thorough analysis of flow cytometric data has enabled rapid differentiation of urinary microorganisms. Integration of dilution parameters (e.g., creatinine, specific gravity, and conductivity) in urine test strip readers and urine particle flow cytometers enables correction for urinary dilution, which improves result interpretation. Automated urinalysis can be used for urinary tract screening and for diagnosing and monitoring a broad variety of nephrological and urological conditions; newer applications show promising results for early detection of urothelial cancer. Concomitantly, the introduction of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has enabled fast identification of urinary pathogens. Automation and workflow simplification have led to mechanical integration of test strip readers and particle analysis in urinalysis. As the information obtained by urinalysis is complex, the introduction of expert systems may further reduce analytical errors and improve the quality of sediment and test strip analysis. With the introduction of laboratory-on-a-chip approaches and the use of microfluidics, new affordable applications for quantitative urinalysis and readout on cell phones may become available. In this review, we present the main recent developments in automated urinalysis and future perspectives.
Automation ; Cell Phones ; Creatinine ; Expert Systems ; Flow Cytometry ; Mass Screening ; Mass Spectrometry ; Microfluidics ; Microscopy ; Semiconductors ; Specific Gravity ; Urinalysis* ; Urinary Tract ; Urinary Tract Infections

BACKGROUND: Severe dehydration decreases renal perfusion. However, it is unclear whether sub-morbid dehydration affects kidney function similarly. Although there have been numerous animal and human studies that have suggested mild dehydration is associated with glomerular hyperfiltration, it has not been confirmed on a large-scale in the general population. Therefore, we aimed to identify the relationship between hydration status and kidney function. METHODS: We reviewed the data of 28,342 adults who participated in the Korea National Health and Nutrition Examination Surveys. Urine specific gravity unit (SGU) was the primary variable that indicated hydration status, and the estimated glomerular filtration rate (eGFR) was used as the primary outcome. RESULTS: Multivariate linear regression analysis showed urine SGU was positively associated with eGFR, which was J-shaped in the multivariate generalized additive model plot. In the penalized spline curve analysis, the odds ratio for high eGFR was steadily increased. Although increased urine SGU was associated with decreased blood pressure and pulse rate, it had no effect on increased fasting glucose and total cholesterol, suggesting conflicting cardio-metabolic dehydration effects. CONCLUSION: Dehydration, presumably sub-morbid in an ambulatory community-dwelling general population, is associated with higher kidney function. The clinical significance of sub-morbid dehydration-associated glomerular hyperfiltration needs further investigation.
Adult ; Animals ; Blood Pressure ; Cholesterol ; Dehydration ; Fasting ; Glomerular Filtration Rate ; Glucose ; Heart Rate ; Humans ; Kidney ; Korea ; Linear Models ; Odds Ratio ; Perfusion ; Renal Insufficiency, Chronic ; Specific Gravity

In 2018, external quality assessment trials for urinalysis and fecal occult blood (FOB) were performed using 1,590 participants. Urine chemistry tests were performed thrice while urine sediment and FOB tests twice. Urine chemistry tests comprised of pH, protein, glucose, ketone body, bilirubin, blood, urobilinogen, nitrite, leukocyte, and specific gravity analyses. The results of urine chemistry and specific gravity tests showed accuracy rates >95%, except for the pH test. The accuracy rate of urine sediments was low, especially for atypical calcium oxalate crystal and red blood cell cast. In the FOB quality test, reagents showed accuracy rates >90%, except for SD and GC Genedia FOB reagents. In the FOB quantitative test, Alfresa NS-Plus C instrument showed falsely high values in the FOB negative specimens.
Bilirubin ; Calcium Oxalate ; Chemistry ; Erythrocytes ; Glucose ; Hydrogen-Ion Concentration ; Indicators and Reagents ; Leukocytes ; Occult Blood ; Quality Control ; Specific Gravity ; Urinalysis ; Urobilinogen

In 2017, external quality assessment trials for urinalysis and fecal occult blood (FOB) were performed with 1,544 participants. Urine chemistry tests were performed three times and urine sediment and FOB tests were evaluated 2 times. Urine chemistry tests consisted of pH, protein, glucose, ketone, bilirubin, blood, urobilinogen, nitrite, leukocyte, and specific gravity analyses. The results of the urine chemistry and specific gravity tests showed accuracy rates >95%. The accuracy rate of urine sediments was low, especially for fat droplets and atypical uric acid crystals. In the FOB quality test, all reagents showed accuracy rates >82%, which suggested the persistent improvement of false-positive reactions. In the FOB quantitative test, discrepant results depending on the instrument used were observed. To compensate for the result differences caused by the amounts of stool samples, the results should be reported using another unit (µg/g of stool).
Bilirubin ; Chemistry ; Glucose ; Hydrogen-Ion Concentration ; Indicators and Reagents ; Korea* ; Leukocytes ; Occult Blood* ; Quality Control ; Specific Gravity ; Uric Acid ; Urinalysis* ; Urobilinogen

The diagnosis of cause of death (COD) or estimation of postmortem interval (PMI) is hard to perform using postmortem blood or other bodily fluids due to various biochemical changes that occur during the agonal phase or after death. To solve these problems, new paradigms and new analytical methods are needed. In this study, postmortem blood was fractionated with specific gravity 1.021, 1.029, 1.038, and 1.045, and the absorbance patterns of each sample of the 131 total cases (12 kinds of COD) were analyzed using a spectrometer. The absorbance was grouped into 9 patterns (ABS pattern 1 to 9) according to the wave length and the signal intensity. These patterns of postmortem blood were found to be distinctly different from the absorbance pattern of fresh blood. The analysis of ABS patterns is useful for the diagnosis of deaths due to acute or rapid bleeding, fire death, drowning and, in some cases, poisoning, but is not useful for the estimation of PMI.
Cause of Death ; Diagnosis ; Drowning ; Felodipine ; Fires ; Hemorrhage ; Poisoning ; Specific Gravity ; Spectrum Analysis

PURPOSE: The aim of this study was to explore the prevalence of major chronic diseases related to daily oral water intake and to identify the physiological parameters related to dehydration in Korean elderly. METHODS: The data were collected from the sixth Korea Health and Nutrition Examination Survey (KHANES), which was a nationwide and cross-sectional survey in 2015. We analyzed 1,392 participants using t-test and logistic regression. All participants were divided into the adequate water intake (AWI) group and the non-adequate water intake (NAWI) group based on the dietary reference intakes for Koreans. RESULTS: There was a significant difference in the water intake between the AWI (6.8 cups in a day) and NAWI (2.8 cups) groups (p < .001). There was no statistically significant association between the level of water intake and any of the major chronic diseases. Blood urea nitrogen (BUN) and BUN/Creatinine (Cr) ratio were significantly higher in the NAWI group. Especially, BUN/Cr ratio shows that the NAWI group reached dehydration status. Older age (adjusted odd ratio, OR=1.07, 95% confidence interval, CI [1.04–1.10]), female gender (adjusted OR=1.56, 95% CI [1.05–2.33]), lower body mass index (BMI) (adjusted OR=1.00, 95% CI [0.92–1.00]), higher BUN (adjusted OR=1.04, 95% CI [1.01–1.08]), and higher urine specific gravity (USG) (adjusted OR=1.56, 95% CI [1.19–2.05]) were factors associated with the NAWI group. CONCLUSION: The findings suggest that the level of water intake needs to be considered in relation to age, gender, BMI, BUN, and USG. These are sensitive physiological parameters used for predicting dehydration of the elderly according to their daily oral water intake. It would be helpful to develop strategies to prevent dehydration in elderly individuals and enhance their water intake.
Aged ; Blood Urea Nitrogen ; Body Mass Index ; Chronic Disease ; Cross-Sectional Studies ; Dehydration ; Drinking ; Female ; Humans ; Korea ; Logistic Models ; Nutrition Surveys ; Prevalence ; Recommended Dietary Allowances ; Specific Gravity ; Water

BACKGROUND: Workers laboring in steel industries in tropical settings with high ambient temperatures are subjected to thermally stressful environments that can create well-known risks of heat-related illnesses and limit workers’ productivity. METHODS: A cross-sectional study undertaken in a steel industry in a city nicknamed “Steel City” in Southern India assessed thermal stress by wet bulb globe temperature (WBGT) and level of dehydration from urine color and urine specific gravity. A structured questionnaire captured self-reported heat-related health symptoms of workers. RESULTS: Some 90% WBGT measurements were higher than recommended threshold limit values (27.2–41.7°C) for heavy and moderate workloads and radiational heat from processes were very high in blooming-mill/coke-oven (67.6°C globe temperature). Widespread heat-related health concerns were prevalent among workers, including excessive sweating, fatigue, and tiredness reported by 50% workers. Productivity loss was significantly reported high in workers with direct heat exposures compared to those with indirect heat exposures (χ2 = 26.1258, degrees of freedom = 1, p < 0.001). Change in urine color was 7.4 times higher among workers exposed to WBGTs above threshold limit values (TLVs). CONCLUSION: Preliminary evidence shows that high heat exposures and heavy workload adversely affect the workers’ health and reduce their work capacities. Health and productivity risks in developing tropical country work settings can be further aggravated by the predicted temperature rise due to climate change, without appropriate interventions. Apart from industries enhancing welfare facilities and designing control interventions, further physiological studies with a seasonal approach and interventional studies are needed to strengthen evidence for developing comprehensive policies to protect workers employed in high heat industries.
Climate Change ; Cross-Sectional Studies ; Dehydration ; Efficiency* ; Fatigue ; Hot Temperature* ; India* ; Seasons ; Specific Gravity ; Steel* ; Sweat ; Sweating ; Threshold Limit Values

BACKGROUND: Determining risk factors for diabetes insipidus (DI) after pituitary surgery is important in improving patient care. Our objective is to determine the factors associated with DI after pituitary surgery. METHODS: We reviewed records of patients who underwent pituitary surgery from 2011 to 2015 at Philippine General Hospital. Patients with preoperative DI were excluded. Multiple logistic regression analysis was performed and a predictive model was generated. The discrimination abilities of the predictive model and individual variables were assessed using the receiving operator characteristic curve. RESULTS: A total of 230 patients were included. The rate of postoperative DI was 27.8%. Percent change in serum Na (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.15 to 1.69); preoperative serum Na (OR, 1.19; 95% CI, 1.02 to 1.40); and performance of craniotomy (OR, 5.48; 95% CI, 1.60 to 18.80) remained significantly associated with an increased incidence of postoperative DI, while percent change in urine specific gravity (USG) (OR, 0.53; 95% CI, 0.33 to 0.87) and meningioma on histopathology (OR, 0.05; 95% CI, 0.04 to 0.70) were significantly associated with a decreased incidence. The predictive model generated has good diagnostic accuracy in predicting postoperative DI with an area under curve of 0.83. CONCLUSION: Greater percent change in serum Na, preoperative serum Na, and performance of craniotomy significantly increased the likelihood of postoperative DI while percent change in USG and meningioma on histopathology were significantly associated with a decreased incidence. The predictive model can be used to generate a scoring system in estimating the risk of postoperative DI.
Area Under Curve ; Craniotomy ; Diabetes Insipidus* ; Discrimination (Psychology) ; Hospitals, General ; Humans ; Incidence ; Logistic Models ; Meningioma ; Neuroendocrinology ; Neurosurgery ; Patient Care ; Postoperative Complications ; Risk Factors ; Specific Gravity ; Vasopressins