Impact of rural versus urban setting on kidney markers: a cross-sectional study in South-Kivu, DRCongo.

BACKGROUND: Most studies of chronic kidney disease (CKD) in Sub-Saharan Africa (SSA) have been conducted in urban settings. They relied on GFR estimated from serum creatinine alone and on the inexpensive, convenient urinary dipstick to assess proteinuria. The dipstick for proteinuria has not been directly compared with the gold standard albumin-to-creatinine ratio (ACR) in a large-sized study in SSA. We hereby assessed the influence of rural versus urban location on the level, interpretation, and diagnostic performance of proteinuria dipstick versus ACR. METHODS: In a cross-sectional population-based study of CKD in both urban (n = 587) and rural (n = 730) settings in South-Kivu, Democratic Republic of Congo (DRC), we assessed the prevalence, performance (sensitivity, specificity, positive predictive value and negative predictive value) and determinants of a positive dipstick proteinuria as compared with albuminuria (ACR). Albuminuria was subdivided into: A1 (< 30 mg/g creatinine), A2 (30 to 299 mg/g creatinine) and A3 (≥ 300 mg/g creatinine). RESULTS: The overall prevalence of positive dipstick proteinuria (≥ 1+) was 9.6 % (95 % CI, 7.9-11.3) and was higher in rural than in urban residents (13.1 % vs. 4.8 %, p < 0.001), whereas the prevalence of albuminuria (A2 or A3) was similar in both sites (6 % rural vs. 7.6 % urban, p = 0.31). In both sites, dipstick proteinuria ≥ 1 + had a poor sensitivity (< 50 %) and positive predictive value (< 11 %) for the detection of A2 or A3. The negative predictive value was 95 %. Diabetes [aOR 6.12 (1.52-24.53)] was a significant predictor of A3 whereas alkaline [aOR 7.45 (3.28-16.93)] and diluted urine [aOR 2.19 (1.35-3.57)] were the main predictors of positive dipstick proteinuria. CONCLUSIONS: ACR and dipstick proteinuria have similar positivity rates in the urban site whereas, in the rural site, dipstick was 2-fold more often positive than ACR. The poor sensitivity and positive predictive value of the dipstick as compared with ACR makes it unattractive as a screening tool in community studies of CKD in SSA.

Comparison of the detection performance of two different one-step-combined test strips with fluorescent microspheres or colored microspheres as tracers for influenza A and B viruses.

BACKGROUND: Influenza A and B viruses mainly cause respiratory infectious disease. Till now, few tests are able to simultaneously detect both, especially in primary medical establishments. METHODS: This study was designed to compare the performance of two different one-step-combined test strips for the detection of influenza A and B: one strip with fluorescent microspheres for tracers (FMT); and the other strip with colored microspheres for tracers (CMT). To test the strips, cultures of influenza A, B, and other pathogenic viruses were used, in addition to 1085 clinical specimens from symptomatic patients with respiratory infections. Real-time RT-PCR was also considered as a reference method used to detect the different results of FMT and CTM. RESULTS: Detection thresholds for influenza A and B cultures using serial dilutions revealed that the sensitivity of FMT was higher than that of CMT (both P < 0.05). With the culture mixtures of Coxsackie virus (A16), enteric cytopathic human orphan virus (ECHO type30), enterovirus (EV71), rotavirus (LLR strain), and enteric adenovirus (AdV 41), specificity assessment demonstrated that there was no cross reaction during the usage of the two test strips as shown by the results which were negative. In the detection of influenza A in 1085 clinical specimens, the total coincidence rate was 96.7%, the positive coincidence rate was 97.1%, and the negative coincidence rate was 96.7%. In the case of influenza B detection, the total coincidence rate was 99.1%, the positive coincidence rate was 92.6%, and the negative coincidence rate was 98.5%. In addition, with influenza A or B real-time RT-PCR detection method, the results showed that, for influenza A, 26 of the 33 specimens that negative with CMT but positive with FMT, showed positive results, and none of the 3 specimens that positive with CMT but negative with FMT showed a positive result; For influenza B, 12 of the 15 specimens that negative with CMT but positive with FMT, showed positive results, and none of the 5 specimens that positive with CMT but negative with FMT showed a positive result. CONCLUSIONS: FMT performed better than CMT in the combined detection of influenza A and B viruses.

Accuracy assessment of consecutive test strip lots for whole blood INR point-of-care instruments: clarifying the role of frozen plasma pools.

Background In the Netherlands, each new lot of test strips for the CoaguChek XS is validated by a group of collaborating centers. The purpose of this study was to assess the accuracy of the international normalized ratio (INR) measured with consecutive test strip lots and the suitability of frozen plasma pools for accuracy evaluation. Methods Each year, a particular lot of CoaguChek XS test strips is used as reference lot. The reference lots have been validated with the International Standard for thromboplastin rTF/09, yielding a mathematical relationship (R1) between reference lot INR and International Standard INR. New lots are compared to the reference lot using patients' capillary blood samples, yielding a relationship (R2) between the new lot INR and the reference lot INR. INRs of the blood samples were within the 1.5-4.5 interval. In parallel, three frozen plasmas pools are analyzed with the test strips. The distance of each plasma point to the line of relationship R2 was assessed. Results Fifty-four test strip lots have been evaluated during 3 years (2014-2016). Mean INR differences between test strip lot and International Standard rTF/09 varied between -0.14 and +0.20 (-4% and +8%, respectively). A positive trend with strip lot sequence number was observed (p<0.001). In several cases, the distance of the frozen plasmas to the whole blood relationship (R2) was greater than the critical value for commutability. Conclusions Using whole blood, all evaluated test strip lots met the analytical bias criterion of ±10%. Frozen plasma pools behave differently compared to whole blood and are not suitable for assessing absolute accuracy of new CoaguChek XS test strips.

The diagnostic performance of human urinary dipsticks to estimate urine pH, specific gravity (SpG), and protein in horses: are they reliable?

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.

Urine Reagent Strips Are Inaccurate for Assessing Hypohydration: A Brief Report.

OBJECTIVE: To assess the diagnostic ability of urine reagent strips to identify hypohydration based on urine specific gravity (USG). DESIGN: This study examined the agreement of USG between strips and refractometry with Bland-Altman, whereas the diagnostic ability of the strips to assess hypohydration was performed by receiver operating characteristic analysis. SETTING: Arkansas high school football preseason practice. PARTICIPANTS: Four hundred fourteen fresh urine samples were analyzed. MAIN OUTCOME MEASURES: Urine specific gravity was assessed by both reagent strips and refractometry. Cutoffs of >1.020 and >1.025 were used for identifying hypohydration. RESULTS: Bland-Altman analysis showed agreement of the 2 methods. Overall diagnostic ability of the urine strip to identify hypohydration was fair (area under the curve 72%-78%). However, the sensitivity to correctly identify hypohydration was poor (63%-71%), and the specificity of correctly identifying euhydration was poor to fair (68%-83%). CONCLUSION: The urine strip method is not valid for assessing hypohydration.

A Novel Immunochromatographic Strip for Antigen Detection of Avian Infectious Bronchitis Virus.

Avian infectious bronchitis virus (IBV) causes considerable economic losses in the poultry industry worldwide, including Taiwan. IBV is among the most important pathogens in chickens, and it spreads rapidly among flocks. In addition to dozens of known serotypes, new viral variants have emerged due to the viral evolution and antigenic variation in IBVs. Therefore, the development of a sensitive, specific, and easily performed assay is crucial for the rapid detection and surveillance of IBV infections. A rapid and simple immunochromatographic strip (ICS) was developed in this study by employing monoclonal antibodies against spike and nucleocapsid proteins of IBV as the tracer and the capture antibody. The ICS showed high specificity in detecting IBV antigens, including several IBV genotypes and novel variants, as opposed to three other common avian respiratory viruses. The detection limit of the strip reached 104.4 50% embryo-infective dose. Moreover, in the experimental chicken model, the strip test demonstrated consistency in detecting IBV with RT-PCR gene detection. Taken together, this antigen detection strip has the potential to serve as an on-farm rapid test for IBV; therefore, it may facilitate surveillance and control of the disease.

A phase IV, single-center, crossover evaluation of the efficacy of an external nasal dilator strip in children with nasal congestion.

BACKGROUND: In the United States and other countries, external nasal dilator strips have been marketed for use by adults and by children ages 5-12 years to improve nasal airflow and provide temporary relief from nasal congestion and stuffiness. OBJECTIVE: The objectives of this exploratory analysis were to assess and correlate objective and subjective measures of efficacy of two nasal strips variants, Kids and adult small/medium (Regular), in children with nasal congestion. The correlation of efficacy for each variant to nose dimensions and age was also explored. METHODS: In a single-center, crossover study, peak nasal inspiratory flow (PNIF) was measured in 40 children with nasal congestion ages 5-12 years before and after application of the nasal strips. Spearman correlations were calculated between objective and subjective measures of efficacy and between efficacy measures, nose dimensions, and age. RESULTS: In the 40 patients who completed the study, both the Kids and the Regular nasal strips worked well and improved the PNIF by 15% (supine position) to 22% (seated position) over baseline. No statistically significant differences in efficacy were found between the two variants of nasal dilator strips. CONCLUSIONS: Use of both the Kids and Regular nasal strips significantly improved the PNIF from baseline in children with nasal congestion, and no new safety signals were observed. There was a slight subjective preference for the Kids nasal strips by the younger children, which indicated that children with smaller noses preferred the Kids nasal strips instead of the larger Regular nasal strips. Clinical trial NCT02113449, www.clinicaltrials.gov.

[Evaluation of second-line antituberculosis drug susceptibilities of multidrug-resistant Mycobacterium tuberculosis complex isolates by E-test method]. / Çok ilaca dirençli Mycobacterium tuberculosis kompleks izolatlarinda ikinci basamak antitüberküloz ilaç duyarliliklarinin E-test yöntemi ile degerlendirilmesi.

Multidrug-resistant (MDR) tuberculosis (TB) constitutes a restricting factor for the effective treatment of TB worldwide. Early diagnosis and appropriate treatment of patients are the most effective strategy in the control of MDR-TB. Therefore, knowledge of drug resistance patterns of the MDR-TB clinical isolates are necessary in planning of an appropriate treatment regimen for the patient. The aims of this study were to detect the susceptibilities of MDR-TB isolates to second-line anti-TB drugs by E-test method, and to compare their results with Löwenstein-Jensen (LJ) proportion method. A total of 122 MDR (resistant to isoniazid and rifampicin) Mycobacterium tuberculosis complex (MTC) strains isolated from samples of patients with pulmonary TB were included in the study. The isolates were identified by conventional methods and first-line anti-TB drug susceptibility testing was performed by the proportion method using LJ medium. The susceptibilities of the isolates to second-line anti-TB drugs [kanamycin (KN), ofloxacin (OFL), ethionamid (ETN), linezolid (LIN)] were tested by proportion method on LJ medium and E-test method on Middlebrook 7H11 medium. For this purpose, E-test strips (bioMerieux, Fransa) of KN (0.016-256 mg/ml), OFL (0.02-32 mg/ml), ETN (0.016-256 mg/ml), and LIN (0.016-256 mg/ml) were used. The susceptibility tests were evaluated in 5., 7., and 10. days after application of the E-test strips, and proportion method on LJ medium was evaluated 28 days later. Second line-anti-TB drug susceptibility results were obtained in 5 to 10 days by E-test. Of the MDR MTC strains 98% (119/122) were susceptible to KN, OFL and LIN, while 2% (3/122) of the strains were resistant to KN and ETN. The correlation between E-test and LJ proportion method was estimated as 96% for KN and ETN, 98% for OFL, and 100% for LIN. When compared with LJ proportion method, the specificity of E-test in the detection of susceptibility to KN, OFL, ETN and LIN were 60%, 38%, 60%, and 100%, respectively, while the sensitivity was 100% for all drugs. Our results indicated that E-test method exhibited high sensitivity and specificity (100%) for LIN, so it may be used alone in susceptibility testing for this drug, however since the specificity is low (38%) for OFL it should be used together with the proportion method. In conclusion, E-test method might contribute for initiation of an early and effective anti-TB drug treatment and control of infection by rapid diagnosis in MDR-TB cases.

Immunochromatographic strip assay for the rapid and sensitive detection of Salmonella Typhimurium in artificially contaminated tomato samples.

This study was designed to confirm the applicability of a liposome-based immunochromatographic assay for the rapid detection of Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella Typhimurium) in artificially contaminated tomato samples. To determine the detection limit and pre-enrichment incubation time (10, 12, and 18 h pre-enrichment in 1% buffered peptone water), the tests were performed with different cell numbers of Salmonella Typhimurium (3 × 10(0), 3 × 10(1), 3 × 10(2), and 3 × 10(3) CFU·mL(-1)) inoculated into 25 g of crushed tomato samples. The assay was able to detect as few as 30 Salmonella Typhimurium cells per 25 g of tomato samples (1.2 cells·g(-1)) after 12 h pre-enrichment incubation. Moreover, when the developed assay was compared with traditional morphological and biochemical culture-based methods as well as colloidal gold nanoparticle-based commercial test strips, the developed assay yielded positive results for the detection of Salmonella Typhimurium within a shorter period time. These findings confirm that the developed assay may have practical application for the sensitive detection of Salmonella Typhimurium in various food samples, including raw vegetables, with a relatively low detection limit and shorter analysis time.

Evaluation of caspofungin susceptibility testing by the new Vitek 2 AST-YS06 yeast card using a unique collection of FKS wild-type and hot spot mutant isolates, including the five most common candida species.

FKS mutant isolates associated with breakthrough or failure cases are emerging in clinical settings. Discrimination of these from wild-type (wt) isolates in a routine laboratory setting is complicated. We evaluated the ability of caspofungin MIC determination using the new Vitek 2 AST-Y06 yeast susceptibility card to correctly identify the fks mutants from wt isolates and compared the performance to those of the CLSI and EUCAST reference methods. A collection of 98 Candida isolates, including 31 fks hot spot mutants, were included. Performance was evaluated using the FKS genotype as the "gold standard" and compared to those of the CLSI and EUCAST methodologies. The categorical agreement for Vitek 2 was 93.9%, compared to 88.4% for the CLSI method and 98.7% for the EUCAST method. Vitek 2 misclassified 19.4% (6/31) of the fks mutant isolates as susceptible, in contrast to <4% for each of the reference methods. The overall essential agreement between the CLSI method and Vitek 2 MICs was 92.6% (88/95) but was substantially lower for fks mutant isolates (78.6% [22/28]). Correct discrimination between susceptible and intermediate Candida glabrata isolates was not possible, as the revised species-specific susceptibility breakpoint was not included in the Vitek 2 detection range (MIC of ≤0.250 to ≥4 mg/liter). In conclusion, the Vitek 2 allowed correct categorization of all wt isolates as susceptible. However, despite an acceptable categorical agreement, it failed to reliably classify isolates harboring fks hot spot mutations as intermediate or resistant, which was in part due to the fact that the detection range did not span the susceptibility breakpoint for C. glabrata.

Short communication: the effect of temperature on performance of milk ketone test strips.

Ketosis is estimated to affect 15% of early lactation dairy cows. A ketone test strip (Keto-Test; Elanco Animal Health, Greenfield, IN) allows producers a method to determine the concentration of ß-hydroxybutyrate (BHBA) in milk to track individual animal and herd incidence of ketosis. The objective of this study was to determine the effect of altering the temperature of milk and the test strips at the time of the test on the reliability of the Keto-Test. A total of 118 Holstein cows, ranging from 5 to 17 DIM, were selected from a commercial Holstein dairy herd in Michigan. A milk sample was collected from the right rear quarter of each cow during the a.m. milking. Each sample was tested under 4 temperature conditions: (1) Keto-Test strips and milk at room temperature (RT; 24.0 ± 0.1°C; control; manufacturer's instructions), (2) cold strips (10.8 ± 0.9°C) and milk at RT, (3) cold strips and fresh milk, and (4) strips at RT and fresh milk. Milk was recorded as negative (0-99 µmol/L), weak positive (100-199 µmol/L), positive (200-499 µmol/L), or highly positive (≥ 500 µmol/L). Blood samples were collected immediately following milk collection and analyzed for BHBA concentration using a ketone test meter. Cows with blood BHBA concentration of ≥ 1,400 µmol/L were considered positive for subclinical ketosis. Accuracy of the Keto-Test strips under the 4 conditions was determined by the κ coefficient of agreement, using the result of condition 1 as the accepted true value. Additionally, sensitivity and specificity were calculated using the blood BHBA concentrations and results of each of the 4 conditions. Using the Keto-Test 60.2% of cows tested negative for milk BHBA, 24.6% tested weak positive, 14.4% tested positive, and 0.8% tested highly positive. The weighted κ coefficient of agreement between the control condition (1) and condition 2, 3, and 4 and 95% lower and upper confidence intervals were as follows: condition 2=0.71 (0.62, 0.80), condition 3=0.69 (0.60, 0.78), and condition 4=0.63 (0.54, 0.73). These results indicate good agreement between the outcome of condition 1 and conditions 2, 3, and 4. The sensitivities/specificities for 1, 2, 3, and 4 were as follows: 0.77/0.79, 0.74/0.75, 0.69/0.88, and 0.69/0.84, indicating that the test in all temperature conditions had a strong ability to detect the presence of BHBA in milk. In conclusion, the reliability of the Keto-Test strips was not dependent on the temperature of the milk or the test strips.

Accuracy of circulating cathodic antigen tests for rapid mapping of Schistosoma mansoni and S. haematobium infections in Southern Sudan.

OBJECTIVE: To evaluate the diagnostic accuracy of a circulating cathodic antigen (CCA) urine dipstick test for detecting Schistosoma mansoni and S. haematobium alongside an integrated rapid mapping survey in Southern Sudan. METHODS AND RESULTS: A total of 373 children aged 5-16 years were included in the study. Of these 26.0% were infected with S. haematobium and 24.5% were infected with S. mansoni, as identified by urine filtration or single Kato-Katz thick smear, respectively. The CCA performed moderately in detecting S. mansoni, with sensitivity of 89.1% and specificity of 74.2%, and poorly in detecting S. haematobium infections, with a sensitivity of 36.8% and specificity of 78.9%. This may be a slight underestimate of true CCA accuracy, since only single stool and urine samples were examined by microscopy. The true 'gold standard' for comparison would have been the collection of multiple stool samples over consecutive days. CONCLUSION: The poor CCA accuracy for diagnosis of urinary schistosomiasis means that this test is currently not suitable for rapid mapping of schistosomiasis in areas where both S. mansoni and S. haematobium may be endemic.

Development of a colloidal gold-based immunochromatographic test strip for the rapid, on-site detection of Pseudomonas aeruginosa in clinical samples.

BACKGROUND: Current procedures for the detection of Pseudomonas aeruginosa require sophisticated equipment, skilled technicians, and a great deal of time. Immunochromatography assays (ICA) are simple and rapid diagnostic procedures that can be performed and interpreted on the spot or at the bedside without a machine. METHODS: We developed a rapid, 1-step immunochromatographic test strip that is well suited to the on-site detection of P. aeruginosa with high sensitivity and specificity. In brief, a monoclonal antibody targeting the outer membrane protein F (OprF) of P. aeruginosa, 3C3B5, was conjugated to colloidal gold and used as a detection antibody. An OprF polyclonal antibody was developed as the capture antibody. Eighty-three clinical samples were examined for P. aeruginosa by rapid 1-step ICA and compared with Multiplex-polymerase chain reaction (M-PCR). RESULTS: The detection limit of this method is 5 × 10(5) CFU/ml for P. aeruginosa and 10 ng/ml for the OprF protein. The immunochromatographic strip test demonstrated a slightly lower sensitivity (84.8%), but a similar specificity (100%), to multi-PCR, which is an accurate method for the detection of P. aeruginosa in the laboratory. We observed no cross-reactivity with non-P. aeruginosa bacterial microbes. The detection of P. aeruginosa by the ICA strip can be completed within 5-10 min and is at least 10-fold faster than M-PCR. CONCLUSIONS: The ICA test strip developed in this study has proved to be a rapid, simple, effective and economical method for the detection of P. aeruginosa infection in clinical samples. To our knowledge, this is the first report of an ICA method being used to detect P. aeruginosa.

Development of a rapid method for the measurement of lactose in milk using a blood glucose biosensor.

Current methods for lactose measurement in dairy products are time consuming and tedious and may require expensive equipment and skilled technicians. The aim of this research was to develop a novel and rapid method for the routine measurement of lactose in dairy products. The proposed method is based on the rapid hydrolysis of lactose using ß-galactosidase and subsequently measuring glucose using a blood glucose meter. Blood glucose meters were developed after decades of research and clinical trials and are used extensively worldwide by individuals with diabetes to monitor their blood glucose levels. The method was developed and validated in a series of experiments. In the first experiment, temperature and time required for the near-complete hydrolysis of lactose were determined. Subsequently, the influence of glucose meters and their test strip lots were evaluated. We found that meters were not significantly different. However, the test strip lots were significantly different from each other. In the second experiment, the proposed method was validated using different concentrations of lactose solutions (1.9-6.5%) and compared with a HPLC-based reference method. In the third experiment, the proposed method was used to determine the lactose content of raw milk. The proposed method shows potential for rapid, routine, and low-cost measurement of lactose in milk and other dairy products.

A pilot study to assess if urine specific gravity and urine colour charts are useful indicators of dehydration in acute stroke patients.

AIM: The purpose of this pilot study was to examine whether urine specific gravity and urine colour could provide an early warning of dehydration in stroke patients compared with standard blood indicators of hydration status. BACKGROUND: Dehydration after stroke has been associated with increased blood viscosity, venous thrombo-embolism and stroke mortality at 3-months. Earlier identification of dehydration might allow us to intervene to prevent significant dehydration developing or reduce its duration to improve patient outcomes. METHODS: We recruited 20 stroke patients in 2007 and measured their urine specific gravity with urine test strips, a refractometer, and urine colour of specimens taken daily on 10 consecutive days and compared with the routine blood urea:creatinine ratios over the same period to look for trends and relationships over time. The agreement between the refractometer, test strips and urine colour were expressed as a percentage with 95% confidence intervals. RESULTS: Nine (45%) of the 20 stroke patients had clinical signs of dehydration and had a significantly higher admission median urea:creatinine ratio (P = 0·02, Mann-Whitney U-test). There were no obvious relationships between urine specific gravity and urine colour with the urea:creatinine ratio. Of the 174 urine samples collected, the refractometer agreed with 70/174 (40%) urine test strip urine specific gravity and 117/174 (67%) urine colour measurements. CONCLUSIONS: Our results do not support the use of the urine test strip urine specific gravity as an early indicator of dehydration. Further research is required to develop a practical tool for the early detection of dehydration in stroke patients.

Glucose meter accuracy and the impact on the care of diabetes in childhood and adolescence.

Blood glucose testing by point-of-care (POC) meters has become increasingly prevalent, and is an essential tool in diabetes management. But most of those who use the meters or rely upon their results for clinical decision-making are unaware of the significant limitations of these meters at present in both inpatient and outpatient settings. This review discusses the limitations of both strips and meters, in both hospital and outpatient settings, and the special problems when caring for diabetes in children and adolescents. It presents data that support the general concern among the experts that POC glucose meters are often inappropriate in critical care, as well reviewing when these meters are appropriate for use in other settings. The review discusses the problem of "outliers", glucose levels that deviate from the true glucose by a relatively large increment, and how these degrade clinical decision-making. Lastly, evidence-based recommendations are provided for changes that are needed to improve the present situation.

Diagnostic biomarkers in tear fluid: from sampling to preanalytical processing.

Tear fluid is receiving growing attention as a source for novel diagnostic biomarkers. Multiple techniques are available for its collection and impact the composition of acquired samples. We sought to provide a direct comparison of two collection methods with regard to implementation, acceptance, and impact on sample composition. Tear fluid was collected from fifteen healthy volunteers with capillary tubes and Schirmer strips and analyzed for total protein and IgG concentrations. Sampling parameters and perception by test persons were compared. The use of capillary tubes was more convenient for the participants while causing more effort for the collector. Tear flow rates as well as the relative and absolute amount of IgG were higher when Schirmer strips were used. Consecutive collections with Schirmer strips significantly influenced tear flow rates, IgG, and protein concentrations. A moderate correlation was observed between tear flow rates and IgG concentrations for both methods. Samples collected with both methods can be analyzed by isoelectric focusing, a potential diagnostic application in the field of neurology. The specific advantages and limitations of tear fluid sampling with either capillary tubes or Schirmer strips demonstrate the need for a thorough investigation of collection methods with regard to the application of interest.

Influence of inflammatory arthritis on leukocyte esterase strip results in the diagnosis of periprosthetic joint infection.

BACKGROUND: The leukocyte esterase (LE) strip is considered as a helpful method to detect infection, which might be influenced by other inflammatory diseases. This study aims to explore whether the centrifugation of synovial fluid could influence the positive result of LE strip caused by inflammatory arthritis during the diagnosis of periprosthetic joint infection (PJI). METHODS: From March 2016 to December 2018, 64 patients who were diagnosed as PJI or aseptic arthritis and another 20 patients with inflammatory arthritis were enrolled in our study. After synovial fluid samples were obtained, the LE strip test was performed with and without centrifugation. Then clinicians read the color changes 3 min after the samples were dropped and classify the results based on the instruction of strip. The differences between septic and aseptic arthritis patients and septic and inflammatory arthritis patients were analyzed. RESULTS: Among the included 21 PJI samples, 19 of them showed positive results (++) of LE strip before centrifugation. After centrifugation, two samples changed from two-positive (++) to one-positive (+), which is also considered as positive. Before centrifugation, 29 of the LE strip tests in the aseptic arthritis group (43 samples included) were ++ or +. After centrifugation, 16 of the samples yielded negative results. Among 20 samples with inflammatory arthritis, LE strip of 18 samples were positive (++ or +) before centrifugation, among which only 3 samples remained as positive after centrifugation. CONCLUSION: LE strip test results could be influenced by inflammatory arthritis during the diagnosis of PJI. Centrifugation should be performed for LE strip tests to determine whether the result is a true positive or a false positive influenced by inflammatory arthritis.

A Sensitive Two-Analyte Immunochromatographic Strip for Simultaneously Detecting Aflatoxin M1 and Chloramphenicol in Milk.

A two-analyte immunochromatographic strip (immunostrip) was developed for the simultaneous detection of aflatoxin M1 (AFM1) and chloramphenicol (CAP) in milk. Protein conjugates (AFM1-ovalbumin (OVA) and CAP-OVA) and goat anti-rabbit IgG were respectively drawn on nitrocellulose membrane as two test lines (T1 and T2) and a control line (C). The immunostrip was dipped into a well that contained a 200 µL milk sample, 5 µL AFM1 antibody-gold conjugates, and 8 µL CAP antibody-gold conjugates; the whole assay was completed in 15 min and the results could be interpreted visually or using a reader. This immunostrip has cut-off levels of 0.1 ng/mL and 0.5 ng/mL for AFM1 and CAP, respectively. Analysis of CAP and AFM1 in milk samples revealed that data from the immunostrip test agreed closely with those obtained from ELISA. The two-analyte immunostrip is a rapid way for on-site simultaneous detection of AFM1 and CAP in milk.