Evaluación del parámetro BACT-info del citómetro de flujo UF-5000 (Sysmex) para la clasificación gram en infección del tracto urinario / Evaluation of Sysmex UF-5000 flow cytometer flag BACT-info for Gram discrimination in urinary tract infection

Introducción: El urocultivo como gold standard para diagnóstico de infección del tracto urinario (ITU) supone una carga de trabajo considerable en los Servicios de Microbiología Clínica, debido al elevado número de muestras recibidas que finalmente serán negativas. Por ello, utilizar sistemas de cribado que además reduzcan el tiempo de respuesta del diagnóstico de ITU es necesario. El nuevo citómetro de flujo UF-5000 (Sysmex Corporation) es capaz de diferenciar entre bacterias gramnegativas y grampositivas mediante el parámetro BACT-info según el fabricante. El objetivo de nuestro estudio fue evaluar la capacidad de discriminación gram del citómetro UF-5000. Métodos: Estudio prospectivo de 449 orinas recogidas de forma consecutiva, en el período 7/3/2022-27/5/2022, en las que se comparó el flag BACT-info con el urocultivo como método de referencia. Resultados: La sensibilidad obtenida tanto para bacterias gramnegativas como positivas fue superior al 95%. Sin embargo, en el caso de bacterias grampositivas, el índice Kappa moderado (0,49) y el valor predictivo positivo bajo (37,1%) indicó que la correlación entre el flag BACT-info y el urocultivo no era aceptable, por lo que no sería recomendable informarlo al clínico peticionario. Conclusión: El uso del citómetro UF-5000 supone un adelanto en la orientación etiológica de las ITUs causadas por bacterias gramnegativas. Informar la morfología gram en la muestra de orina reduce el tiempo de respuesta en el diagnóstico microbiológico de ITU, lo que tendría un impacto en la disminución y optimización del tratamiento empírico, y, por ende, en la generación de resistencias antimicrobianas. (AU)

Introduction. Urine culture as a gold standard for the diagnosis of urinary tract infection (UTI) involves a considerable workload in Clinical Microbiology Departments, due to the high number of samples received that will ultimately be negative. Therefore, it is necessary to use screening systems that also reduce the turnaround time for UTI diagnosis. The new flow cytometer UF-5000 (Sysmex Corporation) is able to differentiate between Gram-negative and Gram-positive bacteria using the BACT-info parameter according to manufacturer. The aim of our study was to evaluate the gram discrimination ability of the UF-5000 cytometer. Methods. A prospective study with 449 urine samples collected consecutively was conducted, in the period 7/3/2022- 27/5/2022, in which the BACT-info flag was compared with urine culture as the reference method. Results. The sensitivity obtained for both Gram-negative and Gram-positive bacteria was above 95%. However, for Gram-positive bacteria, the moderate Kappa index (0.49) and the low positive predictive value (37.1%) indicated that the correlation between BACT-info flag and urine culture was not acceptable and should not be reported to the requesting clinician. Conclusion. Implementation of the third generation UF5000 cytometer represents a significant advance in the aetiological orientation of UTIs caused by Gram-negative bacteria. Reporting the Gram morphology in the urine samples reduces the response time in the microbiological diagnosis of UTI, which would have an impact on the reduction and optimisation of empirical treatment, and thus on the generation of antimicrobial resistance. (AU)

Entrando en el manejo 2.0 de la cistinuria con una herramienta médica digital para monitorizar el pH de la orina: un estudio prospectivo y aleatorizado / Entering into 2.0 cystinuria management with a medical digital tool to monitor urine pH: A prospective, randomized study

Introducción y objetivos Las personas con cistinuria pueden experimentar eventos recurrentes de litiasis debido a la relativa insolubilidad de la cistina en el pH fisiológico de la orina, lo que resulta en deterioro de la función renal. El pHmetro Lit-Control® es un dispositivo médico que permite la automedición precisa del pH de la orina. El objetivo principal de este estudio fue comparar la usabilidad del pHmetro Lit-Control® con las tiras reactivas para la automonitorización domiciliaria del pH urinario por parte de pacientes con cistinuria, y su satisfacción general con cada herramienta.Pacientes y métodosSe incluyeron 28 pacientes (9 mujeres y 19 varones, de 19 a 76 años), que fueron asignados aleatoriamente a monitorizar su pH urinario con tiras reactivas (n=17) o el pHmetro Lit-Control® (n=11).ResultadosDespués de 6 meses de uso, la satisfacción con los 2 métodos fue similarmente alta, pero los pacientes calificaron (en una escala de 0 a 10) mejor el pHmetro en términos de facilidad de aprendizaje (media± DE, 8,11±0,60 vs. 7,06±1,18; p=0,038), facilidad de preparación (8,22±0,67 vs. 7,25±1,18; p=0,034) y facilidad de uso (8,22±0,67 vs. 7,25±1,39; p=0,062). En general, los pacientes no alcanzaron los objetivos de alcalinización (pH entre 7,0 y 8,0).ConclusionesEl pHmetro Lit-Control® demostró ser un dispositivo fácil de usar que puede facilitar el control del pH urinario en los pacientes con cistinuria. Queda justificado un estudio prospectivo para evaluar la correlación entre la monitorización del pH de la orina, una estrategia de tratamiento por objetivo y la recurrencia de los cálculos de cistina. (AU)

Background and objectives Individuals with cystinuria can experiment recurrent lithiasis events due to the relative insolubility of cystine at physiological urine pH, resulting in renal function decline. The Lit-Control® pH Meter is a medical device that accurately allows urine pH self-monitoring. The main objective of this study was to compare the usability of the Lit-Control® pH Meter with the reactive strips for self-monitoring of urinary pH at home by patients with cystinuria, and their overall satisfaction with each tool.Patients and methodsWe included 28 patients (9 females and 19 males, age 19-6 years), who were randomly assigned to monitor their urine pH with reactive strips (n=17) or the Lit-Control® pH Meter (n=11).ResultsAfter six months of use, the satisfaction with the two methods was similarly high, but the patients rated (0-10 scale) the pH meter better in terms of ease of learning (mean±SD, 8.11±0.60 vs. 7.06±1.18; P=.038), ease to prepare (8.22±0.67 vs. 7.25±1.18; P=0.034), and ease of use (8.22±0.67 vs. 7.25±1.39; P=.062). Overall, patients did not reach the alkalinization goals (pH between 7.0 and 8.0).ConclusionsThe Lit-Control® pH Meter demonstrated to be an easy-to-use device that can facilitate urinary pH control by cystinuric patients. A prospective study is warranted to assess the correlation between urine pH monitoring, a treat to target approach, and the recurrence of cystine stones. (AU)

Lens Free Holographic Imaging for Urinary Tract Infection Screening.

OBJECTIVE: The diagnosis of urinary tract infection (UTI) currently requires precise specimen collection, handling infectious human waste, controlled urine storage, and timely transportation to modern laboratory equipment for analysis. Here we investigate holographic lens free imaging (LFI) to show its promise for enabling automatic urine analysis at the patient bedside. METHODS: We introduce an LFI system capable of resolving important urine clinical biomarkers such as red blood cells, white blood cells, crystals, and casts in 2 mm thick urine phantoms. RESULTS: This approach is sensitive to the particulate concentrations relevant for detecting several clinical urine abnormalities such as hematuria and pyuria, linearly correlating to ground truth hemacytometer measurements with R 2 = 0.9941 and R 2 = 0.9973, respectively. We show that LFI can estimate E. coli concentrations of 10 3 to 10 5 cells/mL by counting individual cells, and is sensitive to concentrations of 10 5 cells/mL to 10 8 cells/mL by analyzing hologram texture. Further, LFI measurements of blood cell concentrations are relatively insensitive to changes in bacteria concentrations of over seven orders of magnitude. Lastly, LFI reveals clear differences between UTI-positive and UTI-negative urine from human patients. CONCLUSION: LFI is sensitive to clinically-relevant concentrations of bacteria, blood cells, and other sediment in large urine volumes. SIGNIFICANCE: Together, these results show promise for LFI as a tool for urine screening, potentially offering early, point-of-care detection of UTI and other pathological processes.

Using social media to crowdsource collection of urine samples during a national pandemic.

The COVID-19 pandemic and subsequent lockdown had a substantial impact on normal research operations. Researchers needed to adapt their methods to engage at-home participants. One method is crowdsourcing, in which researchers use social media to recruit participants, gather data, and collect samples. We utilized this method to develop a diagnostic test for Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). Participants were recruited via posts on popular social-media platforms, and enrolled via a website. Participants received and returned a mail kit containing bladder symptom surveys and a urine sample cup containing room-temperature preservative. Using this method, we collected 1254 IC/BPS and control samples in 3 months from all 50 United States. Our data demonstrate that crowdsourcing is a viable alternative to traditional research, with the ability to reach a broad patient population rapidly. Crowdsourcing is a powerful tool for at-home participation in research, particularly during the lockdown caused by the COVID-19 pandemic.

Verification of Atellica 1500 and comparison with Iris urine analyser and urine culture.

INTRODUCTION: The aims of study were to assess: 1) performance specifications of Atellica 1500, 2) comparability of Atellica 1500 and Iris, 3) the accuracy of both analysers in their ability to detect bacteria. MATERIALS AND METHODS: Carryover, linearity, precision, reproducibility, and limit of blank (LoB) verification were evaluated for erythrocyte and leukocyte counts. ICSH 2014 protocol was used for estimation of carryover, CLSI EP15-A3 for precision, and CLSI EP17 for LoB verification. Comparison for quantitative parameters was evaluated by Bland-Altman plot and Passing-Bablok regression. Qualitative parameters were evaluated by Weighted kappa analysis. Sixty-five urine samples were randomly selected and sent for urine culture which was used as reference method to determine the accuracy of bacteria detection by analysers. RESULTS: Analytical specifications of Atellica 1500 were successfully verified. Total of 393 samples were used for qualitative comparison, while 269 for sediment urinalysis. Bland-Altman analysis showed statistically significant proportional bias for erythrocytes and leukocytes. Passing-Bablok analysis for leukocytes pointed to significant constant and minor proportional difference, while it was not performed for erythrocytes due to significant data deviation from linearity. Kappa analysis resulted in the strongest agreements for pH, ketones, glucose concentrations and leukocytes, while the poorest agreement for bacteria. The sensitivity and specificity of bacteria detection were: 91 (59-100)% and 76 (66-87)% for Atellica 1500 and 46 (17-77)% and 96 (87-100)% for Iris. CONCLUSION: There are large differences between Atellica 1500 and Iris analysers, due to which they are not comparable and can not be used interchangeably. While there was no difference in specificity of bacteria detection, Iris analyser had greater sensitivity.

Design and Functionalization of a µPAD for the Enzymatic Determination of Nitrate in Urine.

In this work, the design of a microfluidic paper-based analytical device (µPAD) for the quantification of nitrate in urine samples was described. Nitrate monitoring is highly relevant due to its association to some diseases and health conditions. The nitrate determination was achieved by combining the selectivity of the nitrate reductase enzymatic reaction with the colorimetric detection of nitrite by the well-known Griess reagent. For the optimization of the nitrate determination µPAD, several variables associated with the design and construction of the device were studied. Furthermore, the interference of the urine matrix was evaluated, and stability studies were performed, under different conditions. The developed µPAD enabled us to obtain a limit of detection of 0.04 mM, a limit of quantification of 0.14 mM and a dynamic concentration range of 0.14-1.0 mM. The designed µPAD proved to be stable for 24 h when stored at room temperature in air or vacuum atmosphere, and 60 days when stored in vacuum at -20 °C. The accuracy of the nitrate µPAD measurements was confirmed by analyzing four certified samples (prepared in synthetic urine) and performing recovery studies using urine samples.

Single Extracellular Vesicle Analysis Performed by Imaging Flow Cytometry and Nanoparticle Tracking Analysis Evaluate the Accuracy of Urinary Extracellular Vesicle Preparation Techniques Differently.

Small extracellular vesicles isolated from urine (uEVs) are increasingly recognized as potential biomarkers. Meanwhile, different uEV preparation strategies exist. Conventionally, the performance of EV preparation methods is evaluated by single particle quantification, Western blot, and electron microscopy. Recently, we introduced imaging flow cytometry (IFCM) as a next-generation single EV analysis technology. Here, we analyzed uEV samples obtained with different preparation procedures using nanoparticle tracking analysis (NTA), semiquantitative Western blot, and IFCM. IFCM analyses demonstrated that urine contains a predominant CD9+ sEV population, which exceeds CD63+ and CD81+ sEV populations. Furthermore, we demonstrated that the storage temperature of urine samples negatively affects the recovery of CD9+ sEVs. Although overall reduced, the highest CD9+ sEV recovery was obtained from urine samples stored at -80 °C and the lowest from those stored at -20 °C. Upon comparing the yield of the different uEV preparations, incongruencies between NTA and IFCM data became apparent. Results obtained by both NTA and IFCM were consistent with Western blot analyses for EV marker proteins; however, NTA results correlated with the amount of the impurity marker uromodulin. Despite demonstrating that the combination of ultrafiltration and size exclusion chromatography appears as a reliable uEV preparation technique, our data challenge the soundness of traditional NTA for the evaluation of different EV preparation methods.

Proteinuria is independently associated with carotid atherosclerosis: a multicentric study.

BACKGROUND AND AIMS: Atherosclerosis is a vital cause of cardiovascular diseases. The correlation between proteinuria and atherosclerosis, however, has not been confirmed. This study aimed to assess whether there is a relationship between proteinuria and atherosclerosis. METHODS: From January 2016 to September 2020, 13,545 asymptomatic subjects from four centres in southern China underwent dipstick proteinuria testing and carotid atherosclerosis examination. Data on demography and past medical history were collected, and laboratory examinations were performed. The samples consisted of 7405 subjects (4875 males and 2530 females), excluding subjects failing to reach predefined standards and containing enough information. A multivariate logistic regression model was used to adjust the influence of traditional risk factors for atherosclerosis on the results. RESULTS: Compared with proteinuria-negative subjects, proteinuria-positive subjects had a higher prevalence rate of carotid atherosclerosis. The differences were statistically significant (22.6% vs. 26.7%, χ2 = 10.03, p = 0.002). After adjusting for common risk factors for atherosclerosis, age, sex, BMI, blood lipids, blood pressure, renal function, hypertensive disease, diabetes mellitus and hyperlipidaemia, proteinuria was an independent risk factor for atherosclerosis (OR = 1.191, 95% CI 1.015-1.398, p = 0.033). The Hosmer-Lemeshow test was used to test the risk prediction model of atherosclerosis, and the results showed that the model has high goodness of fit and strong independent variable prediction ability. CONCLUSIONS: Proteinuria is independently related to carotid atherosclerosis. With the increase in proteinuria level, the risk of carotid atherosclerotic plaque increases. For patients with positive proteinuria, further examination of atherosclerosis should not be ignored.

Evaluation of the Atellica® UAS 800: a new member of the automated urine sediment analyzer family.

BACKGROUND: In 2017 the Atellica® UAS 800 urine sediment analyzer was introduced by Siemens Healthineers. We investigated its applicability in the standardization and automation of the laboratory urinalysis workflow, including the prediction of urine culture outcome and glomerular pathology. METHODS: We evaluated the performance characteristics of the Atellica® UAS 800 and its correlation with the iQ200 (Beckman Coulter). In addition, we studied the agreement between Atellica® UAS 800 and CLINITEK Novus® and determined the predictive value of bacteria and leukocyte counts for urine culture outcome. Furthermore, we investigated the ability of Atellica® UAS 800 to identify pathological casts and dysmorphic erythrocytes in comparison to manual microscopy. RESULTS: Erythrocyte and leukocyte analyses indicated high intra- and inter-run precisions and good correlations with the iQ200. We found that the Atellica® UAS 800 detects bacteria with higher sensitivity than the iQ200. The Atellica® UAS 800 and CLINITEK Novus® showed a high degree of conformity. We determined seven combinations of clinical cut-off values of bacteria and leukocytes for predicting urine culture outcome with sensitivity, specificity, and negative predictive values of 95%, 52%, and 93%, respectively. Using the Atellica® UAS 800, hyaline casts, erythrocyte casts, leukocyte casts, and dysmorphic erythrocytes were correctly recognized in 76%, 22%, 2%, and 39% of the samples, respectively. CONCLUSIONS: The Atellica® UAS 800 is a robust, fast, and user-friendly analyzer, which accurately quantifies erythrocytes, leukocytes, bacteria and squamous epithelial cells, and may be utilized for predicting positive urine cultures. The detection of clinically important pathological casts and dysmorphic erythrocytes proved insufficient.

New microfluidic paper-based analytical device for iron determination in urine samples.

Iron is an important micronutrient involved in several mechanisms in the human body and can be an important biomarker. In this work, a simple and disposable microfluidic paper-based analytical device (µPAD) was developed for the quantification of iron in urine samples. The detection was based on the colorimetric reaction between iron(II) and bathophenanthroline and the reduction of iron(III) to iron(II) with hydroxylamine. The developed µPAD enabled iron determination in the range 0.07-1.2 mg/L, with a limit of detection of 20 µg/L and a limit of quantification of 65 µg/L, thus suitable for the expected values in human urine. Additionally, targeting urine samples, the potential interference of the samples color was overcome by incorporating a sample blank assessment for absorbance subtraction. Stability studies revealed that the device was stable for 15 days prior to usage and that the formed colored product was stable for scanning up to 3 h. The accuracy of the developed device was established by analyzing urine samples (#26) with the developed µPAD and with the atomic absorption spectrometry method; the relative deviation between the two sets of results was below 9.5%.

Prognostic significance of urinary protein and urinary ketone bodies in acute ischemic stroke.

BACKGROUND AND AIMS: Prior studies have shown an association between positive urinary protein and an elevated risk of long-term mortality in patients with acute ischemic stroke (AIS); however, data on the short-term prognostic significance of urinary protein and urinary ketone bodies in patients with AIS is sparse. METHODS AND RESULTS: A total of 2842 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included. Patients were divided into urinary protein positive and negative, urinary ketone bodies positive and negative by urine dipstick. Cox and logistic regression models were used to estimate the effect of urinary protein and urinary ketone bodies on all cause in-hospital mortality and poor outcome upon discharge (modified Rankin Scale score ≥3) in AIS patients. Patients with positive urinary protein was associated with a 2.74-fold and 1.62-fold increase in the risk of in-hospital mortality (adjusted HR 2.74; 95% CI, 1.54-4.89; P-value = 0.001) and poor outcome upon discharge (aOR, 1.62; 95% CI 1.26-2.08; P-value <0.001) in comparison to negative urinary protein after adjusting for potential covariates. Moreover, Patients with positive urinary ketone bodies was associated with 2.11-fold in the risk of poor outcome upon discharge (aOR 2.11; 95% CI 1.52-2.94; P-value <0.001) but not in-hospital mortality (P-value = 0.066) after adjusting for potential covariates. CONCLUSIONS: Urinary protein at admission was independently associated with in-hospital mortality and poor functional outcome at hospital discharge in acute stroke patients and urinary ketone bodies also associated with poor functional outcome at hospital discharge.

Sysmex UF-5000 Automatic Urine Sediment Analyzer Can Improve the Accuracy of Epithelial Cell Detection.

OBJECTIVE: The aim of this study was to evaluate the consistency and accuracy of all the parameters of the urine samples detected by two automated urine sediment analyzers from Sysmex Corporation. METHODS: Two automated analyzers and manual microscopy examined 1,059 urine samples. The sensitivity, specificity, positive predictive value, and negative predictive value were evaluated. The consistency of all the parameters was tested. The influencing factors of false positive and false negative samples were analyzed and compared. RESULTS: All the parameters had good specificity, negative predictive value, and coincidence rate (83.95%-99.61%). The RBC, WBC, and X'TAL analyzed by UF-5000 and UF-1000i exhibited good agreement (Kappa=0.597-0.784) with those by manual microscopy. The overall concordance rates of RBC and WBC were good (RBC: r=0.9842, CCC=0.9693; WBC: r=0.9955, CCC=0.9711). Among the influencing factors, mucus filament accounted for a large proportion, which mainly affected the detection of CAST. Concurrently, the false-positive factors of EC detection were reduced, and CAST did not affect the detection of EC. CONCLUSION: The parameters of the two instruments tested have shown high accuracy, consistency, coincidence rate, and low negative predictive value for RBC and WBC, which has ensured that UF-5000 and UF-1000i meet the clinical requirements for urine tests for disease screening. For the samples with poor consistency and false-positive factors, a conventional microscopic examination should be applied to verify the accuracy of the instrument detection.

Weight loss reduces the incidence of dipstick proteinuria: a cohort study from the Japanese general population.

BACKGROUND: Though elimination of obesity is one of main therapeutic goal for lifestyle-related diseases, the impact of appropriate weight loss on reduction of the incidence of proteinuria in the general population is still unclear. METHODS: The study cohort was based on a general population of 9,33,490 from 40 to 74 years of age who had undergone annual specific health checkups. The subjects who were finally included were the 2,74,598 people for whom all the data necessary for this study were available. The incidence of proteinuria in this study was defined as negative proteinuria at the primary and secondary survey years, and newly developed proteinuria during subsequent follow-up years. RESULTS: Whereas people with rapidly decreased weight tended to have a high incidence of proteinuria in the underweight (BMI < 18.5 kg/m2) and normal weight (18.5-24.9 kg/m2) groups, the obese group (≥ 25.0 kg/m2) with rapidly decreased weight had a lower incidence compared to those with stable weight. In the obese population, a rapid decline of BMI (- 1 to - 5 kg/m2 per year) was associated with a reduced risk (hazard ratio [95% confidence interval]; 0.89 [0.80-0.98], P = 0.02) of proteinuria. CONCLUSIONS: Weight reduction can lead to a risk reduction of 11% in the incidence of proteinuria in obese Japanese adults. This is the first study to report the effects of weight reduction on the early phase of chronic kidney disease in obesity relevant to the characteristics of the Japanese general population. The present findings might have a role in renal health promotion in Japan.

The association between frailty and chronic kidney disease; cross-sectional analysis of the Nambu Cohort Study.

BACKGROUND: Both frailty and chronic kidney disease (CKD) increase with age and share many similarities. Many studies have demonstrated an association between frailty and chronic kidney disease (CKD), but an association with dipstick proteinuria is limited. METHODS: This is the cross-sectional analysis of the Nambu Cohort Study at the beginning of observation. Frailty was diagnosed using Kihon Checklist. Logistic analysis was used to evaluate the association between frailty and CKD or dipstick proteinuria. RESULTS: Among a total of 630 outpatients [age, 78 (70-84) years, men, 50%], the prevalence of patients with pre-frailty and frailty was 32% and 40%, respectively. The proportion of patients with pre-frailty and frailty increased with decreasing estimated glomerular filtration rate (eGFR) and increasing dipstick proteinuria levels. The odds ratios (95% confidence intervals) for CKD stage of 60 < eGFR ≤ 45 ml/min/1.73 m2, and 45 ml/min/1.73 m2 < eGFR for frailty was 0.87 (0.56-1.35) and 2.54 (1.46-4.53), respectively, compared with non-CKD as a reference. Furthermore, the odds ratios for the frailty of dipstick proteinuria with ± and + or over were 1.36 (0.88-2.09) and 1.78 (1.00-3.17), respectively, when dipstick proteinuria-was used as a reference. Moreover, the combination of eGFR and dipstick proteinuria levels increased the odds ratio for pre-frailty and frailty. CONCLUSION: Elderly patients with CKD had a higher prevalence of pre-frailty and frailty. By adding urinary protein information to eGFR, the link between CKD and frailty becomes even more robust.

Urine toxicology screening by liquid chromatography time-of-flight mass spectrometry in a quaternary hospital setting.

OBJECTIVE: Validation of a non-targeted method for urine drug screening (UDS) by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF), and comparison to an established GC-MS method in a hospital setting. METHODS: 217 UDS specimens sent to a quaternary hospital pathology department, were analysed by a CEDIA® immunoassay screen (six drug panels; amphetamines, barbiturates, benzodiazepines, cocaine metabolites, cannabinoids and opiates) on an Abbott Architect instrument. Specimens were subsequently analysed by an established non-targeted qualitative GC-MS method and results compared with a general unknown screening method by LC-QTOF that was under evaluation as a replacement method. RESULTS: 42 selected drugs were evaluated; limits of identification ranged from 2 to 100 µg/L and most drugs (n = 39) were stabile for 24 h after preparation. Matrix effects greater than 25% were observed in seven of the selected drugs. 87% of the specimens tested positive to 1 or more drug panels in a CEDIA® screen. A total of 537 positive drug findings were identified by GC-MS compared to 1,267 positive findings by LC-QTOF. On average, each GC-MS screen identified 2.5 ± 1.8 drugs and the LC-QTOF screen identified 5.8 ± 3.2 drugs. No drugs were identified in 11.3% of the GC-MS screens, whereas drugs were detected in 99% of these by the LC-QTOF. In almost all instances, the LC-QTOF screen could provide mass spectrometric confirmatory results of positive immunoassay screens and was able to identify a wider range of additional drugs and drug metabolites. CONCLUSIONS: The described general unknown screening (non-targeted, qualitative) LC-QTOF method can detect a larger range of drugs encountered in a hospital setting. The method has been shown to be suitable for comprehensive toxicology screening in a clinical toxicology laboratory.

Urinary MicroRNA-Based Diagnostic Model for Central Nervous System Tumors Using Nanowire Scaffolds.

There are no accurate mass screening methods for early detection of central nervous system (CNS) tumors. Recently, liquid biopsy has received a lot of attention for less-invasive cancer screening. Unlike other cancers, CNS tumors require efforts to find biomarkers due to the blood-brain barrier, which restricts molecular exchange between the parenchyma and blood. Additionally, because a satisfactory way to collect urinary biomarkers is lacking, urine-based liquid biopsy has not been fully investigated despite the fact that it has some advantages compared to blood or cerebrospinal fluid-based biopsy. Here, we have developed a mass-producible and sterilizable nanowire-based device that can extract urinary microRNAs efficiently. Urinary microRNAs from patients with CNS tumors (n = 119) and noncancer individuals (n = 100) were analyzed using a microarray to yield comprehensive microRNA expression profiles. To clarify the origin of urinary microRNAs of patients with CNS tumors, glioblastoma organoids were generated. Glioblastoma organoid-derived differentially expressed microRNAs (DEMs) included 73.4% of the DEMs in urine of patients with parental tumors but included only 3.9% of those in urine of noncancer individuals, which suggested that many CNS tumor-derived microRNAs could be identified in urine directly. We constructed the diagnostic model based on the expression of the selected microRNAs and found that it was able to differentiate patients and noncancer individuals at a sensitivity and specificity of 100 and 97%, respectively, in an independent dataset. Our findings demonstrate that urinary microRNAs extracted with the nanowire device offer a well-fitted strategy for mass screening of CNS tumors.

Evaluation of urine dipstick for proteinuria assessment in pet rabbits.

BACKGROUND: Naturally occurring kidney disease (KD) in pet rabbits has not been fully characterized. It has been previously suggested that proteinuria, especially when associated with isosthenuria, may be an early indicator of KD prior to azotaemia in rabbits. The aim of the current study was to assess the diagnostic utility of the urinary protein dipstick test (UPDT) for detecting proteinuria in rabbit urine samples as a useful diagnostic tool in clinical setting. METHODS: Three hundred urinalyses from 156 pet rabbits were retrospectively analysed by comparing the UPDT with the urine protein:creatinine ratio (UPC) to assess its diagnostic performance in detecting proteinuria, defined as UPC > 0.3. Sensitivity, specificity, positive and negative predictive values (NPVs) were determined. RESULTS: When urine-specific gravity (USG) was ≤1.024 and a UPDT result of >0 was considered proteinuric, the specificity and positive predictive value (PPV) were both 100%. Following the same criteria, specificity and PPV decreased to 92.1% and 92.5% when USG was ≤1.038. NPVs were poor. CONCLUSION: In rabbits, a UPDT result > 0 is indicative of proteinuria (UPC > 0.3) when the USG is ≤1.024. In all other cases, proteinuria should be measured using the UPC.

Rapid Characterization of Drugs in Biological Fluid and Seized Material Using Thermal-Assisted Carbon Fiber Ionization Mass Spectrometry.

Developing a rapid, simple, and sensitive method to analyze drugs is critical to forensic research study because of the widespread occurrence of the matrix effect. Herein, we develop a method using thermal-assisted carbon fiber ionization mass spectrometry that can be used to directly analyze drugs in biological fluid. The key feature of this technique is that the biological samples such as urine and blood can be achieved online as precipitated protein on the carbon fiber tip and thermally desorbed by the metal ceramics heater, which can reduce the matrix effects and improve the sensitivity. Analytes including raw urine, blood, oral fluid, drink, tobacco tar, drug tablets, and paper cards can be rapidly identified and analyzed within a few minutes regardless of their physical variations. Due to its simplicity and noninvasive analysis, this method can be used for drugged driving analysis and to achieve point-of-care drug testing in clinical and forensic chemistry.

Tunable infrared metamaterial-based biosensor for detection of hemoglobin and urine using phase change material.

This paper reports about the outcomes from an investigation carried out on tunable biosensor for detection using infrared in the range of 1.5 µm and 1.65 µm. The biosensor is made of phase change material formed by different alloy combinations, Ge2Sb2Te5 (GST). The nature of GST allows for the material to change phase with changes in temperature, giving the tunable sensing property for biosensing application. Sensor built with amorphous GST (aGST) and crystalline GST (cGST) in different design structures were tested on different concentrations of biomolecules: hemoglobin (10 g/l, 20 g/l, 30 g/l and 40 g/l); and urine (0-1.5 mg/dL, 2.5 mg/dL, 5 mg/dL and 10 mg/dL). The tunable response observed from the tests demonstrates the potential application of the materials in the design of switching and sensing systems.

Comparison of three types of analyzers for urine protein-to-creatinine ratios in dogs.

BACKGROUND: Quantitation of urine protein is important in dogs with chronic kidney disease. Various analyzers are used to measure urine protein-to-creatinine ratios (UPCR). OBJECTIVES: This study aimed to compare the UPCR obtained by three types of analyzers (automated wet chemistry analyzer, in-house dry chemistry analyzer, and dipstick reading device) and investigate whether the differences could affect clinical decision process. METHODS: Urine samples were collected from 115 dogs. UPCR values were obtained using three analyzers. Bland-Altman and Passing Bablok tests were used to analyze agreement between the UPCR values. Urine samples were classified as normal or proteinuria based on the UPCR values obtained by each analyzer and concordance in the classification evaluated with Cohen's kappa coefficient. RESULTS: Passing and Bablok regression showed that there were proportional as well as constant difference between UPCR values obtained by a dipstick reading device and those obtained by the other analyzers. The concordance in the classification of proteinuria was very high (κ = 0.82) between the automated wet chemistry analyzer and in-house dry chemistry analyzer, while the dipstick reading device showed moderate concordance with the automated wet chemistry analyzer (κ = 0.52) and in-house dry chemistry analyzer (κ = 0.53). CONCLUSIONS: Although the urine dipstick test is simple and a widely used point-of-care test, our results indicate that UPCR values obtained by the dipstick test are not appropriate for clinical use. Inter-instrumental variability may affect clinical decision process based on UPCR values and should be emphasized in veterinary practice.