Standard Reference Method Research Articles

Comparison of two adult mosquito sampling methods with human landing catches in south-central Ethiopia

BackgroundThe human landing catch (HLC) is the standard reference method for measuring human exposure to mosquito bites. However, HLC is labour-intensive, exposes collectors to infectious mosquito bites and is subjected to collector bias. These necessitate local calibration and application of alternative methods. This study was undertaken to determine the relative sampling efficiency (RSE) of light traps with or without yeast-produced carbon dioxide bait vs. HLC in south-central Ethiopia.MethodsThe experiment was conducted for 39 nights in a 3 × 3 Latin square randomized design with Anopheles arabiensis as the target species in the period between July and November 2014 in Edo Kontola village, south-central Ethiopia. Center for Disease Control and Prevention light trap catches (LTC) and yeast-generated carbon dioxide-baited light trap catches (CB-LTC) were each evaluated against HLC. The total nightly mosquito catches for each Anopheles species in either method was compared with HLC by Pearson correlation and simple linear regression analysis on log-transformed [log10(x + 1)] values. To test if the RSE of each alternative method was affected by mosquito density, the ratio of the number of mosquitoes in each method to the number of mosquitoes in HLC was plotted against the average mosquito abundance.ResultsOverall, 7606 Anopheles females were collected by the three sampling methods. Among these 5228 (68.7%) were Anopheles ziemanni, 1153 (15.2%) An. arabiensis, 883 (11.6%) Anopheles funestus s.l., and 342 (4.5%) Anopheles pharoensis. HLC yielded 3392 (44.6%), CB-LTC 2150 (28.3%), and LTC 2064 (27.1%) Anopheles females. The RSEs of LTC and HLC for An. arabiensis were significantly correlated (p < 0.001) and density independent (p = 0.65). However, for outdoor collection of the same species, RSEs of LTC and CB-LTC were density dependent (p < 0.001). It was estimated that on average, indoor LTC and CB-LTC each caught 0.35 and 0.44 times that of indoor HLC for An. arabiensis respectively.ConclusionsResults showed that HLC was the most efficient method for sampling An. arabiensis. LTC can be used for large-scale indoor An. arabiensis surveillance and monitoring when it is difficult to use HLC. CB-LTC does not substantially improve sampling of this major vector compared to LTC in this setting.Trial registration PACTR201411000882128 (retrospectively registered 8 September, 2014)

Microsphere based continuous-flow immunoassay in a microfluidic device for determination of clinically relevant insulin levels

This paper describes a miniaturized microsphere-based immunoassay integrated into a microfluidic device for rapid quantitation of insulin. Analysis of bionic pancreas studies have revealed that the rates of absorption of insulin analogs vary from patient to patient, and even within patients on different occasions. Thus development of an approach to monitor insulin continuously allows the pharmacokinetic characteristics of insulin analogs to be determined in real-time. The authors have developed a microsphere-based continuous flow assay in a microfluidic chip that allows for the detection of insulin within seconds with high sensitivity and specificity. The method was applied to near real-time monitoring of clinical samples. Calibration plot were established for different insulin analogs such as insulin aspart (Novolog), insulin lispro (Humalog), and regular human insulin (RHI) and the insulin detection limit was 0.26 ng.mL−1 (44 pM). This sensitivity allows to detect the fasting insulin levels of T1D patients, which are reported in the range of 50–180 pM (0.3–1 ng.mL−1), after treatment with subcutaneous insulin administration. This fast approach was also applied to sera collected in intervals from T1D patients after a bolus of insulin aspart delivery. The insulin profile obtained by this method is similar to the basal and peak insulin levels as determined using the standard non-continuous ELISA reference method. In our perception, this assay will improve healthcare by personalizing diagnostics for better clinical outcome and provide real-time feedback on sensing and actuation.

Phytochemical and Proximate Analysis of Some Medicinal Leaves

The proximate analysis and the phytochemical constituents were investigated in Magnifera, Morinda lucida, Parquetina nigrescens, Oscmium gratissimum, Chenopodium ambrosioides and Veronia amygaldalina using standard reference methods. The proximate analysis in % showed that Chenopodium ambrosioides had the highest amount of ash content of 17.30 and moisture content of 89.40 while Magnifera indica had the lowest amount of ash content 12.04 and moisture content 68.40. Veronia amygaldalina had the highest amount of protein 30.02 and carbohydrate 54.00 while Parquetina nigrescens had the least amount of protein 25.06 and carbohydrate 40.23. Parquetina nigrescens had the highest amount of crude fibre of 25.05 while Chenopodium ambrosioides had the highest amount of crude fat 18.22. The moisture content was found to be 89.40%, ash content 17.30, fat 18.22%, protein 30.02%, crude fibre 25.05% and carbohydrate 54.00%. The phytochemical constituents indicated flavonoid 28.58% alkaloid 25.84% and tannin 2.94% in Magnifera indica, Veronia amygaldalina and Morinda lucida respectively. The presence of high secondary metabolites in the leaves are good indication that if the plant is subjected to further research such as identification and characterization of plant, bioactive compounds with strong biological activities may be isolated and novel compounds may also be identified.

Advancing Flavor Stability Improvements in Different Beer Types Using Novel Electron Paramagnetic Resonance Area and Forced Beer Aging Methods

Three different electron paramagnetic resonance (EPR) metrics—lag time, T150, and area—were compared with sensory data from two forced beer aging methods. Three types of beers were evaluated, namely, 1) standard lager, 5% alcohol by volume (ABV) and 3.30° standard reference method (SRM) color; 2) low-alcohol lager, 3% ABV and 2.20° SRM color; and 3) standard ale, 5% ABV and 4.00° SRM color. The two accelerated aging time–temperature treatments evaluated in this study were 18 days at 27°C and six days at 40°C, both being equivalent sensory-wise to our standard flavor stability staling rate of six months at 20°C. A significant relationship between EPR area and sensory staleness scores was found using the 40°C for six days temperature abuse treatment protocol (R2 = 0.9209–0.9567), not the 27°C for 18 days abuse treatment protocol (R2 = 0.0319–0.2046). In addition, the area under the curve metric displayed significant correlation coefficients (R2 = 0.9209–0.9567) with the 40°C for six days abuse treatment staling scores, whereas the traditional lag time and T150 values were not significant (R2 = 0.0174–0.2238 and 0.1010–0.8565, respectively). Using this analytical and sensory chemoetricstyle approach, subsequent brewing materials and process changes were made in the brewing process to lower the EPR area values in five breweries spanning three years of profiling. This resulted in improved packaged beer flavor stability. Using the connection between these novel, rapid methods, this study also highlights three causative beer conditions that have traditionally shown major impacts on flavor stability: namely, trace metals (Cu and Fe), dissolved oxygen, and bisulfite (SO2) levels. Using the EPR area metric, which represents the total amount of free radicals generated during the beer sample analysis time, led the way to engage a rapid forced beer sensory method. Once employed, longer packaged beer shelf-life improvements over the three-year period were realized. This new dynamic program is currently being used in our breweries.

HPLC Standardization of The Methanolic Extract of Acrocarpus fraxinifolius leaves based on Gallic acid Content

High-Performance Liquid Chromatography (HPLC) was developed for the standardization and quantification of gallic acid in the methanolic extract of Acrocarpus fraxinifolius Weight & Arn leaves. Linearity was observed in the range of 0.4–2 mg/mL with a correlation coefficient (r2) of 0.9978. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0054 mg/mL and 0.0163 mg/mL, respectively indicating the sensitivity of the applied method. Recovery values of 100.377 % indicate the best accuracy of the method. Gallic acid content was quantified as 168.75 ± 1.05 mg/g methanolic extract. This developed method was simple, accurate and precise to be used as a reference standard method for determination of gallic acid content in the plant extract.

Revisiting Acid-Fast Bacilli Microscopy of Concentrated Sputum Smears as an Efficient Tool for the Diagnosis of Tuberculosis: A Study from a Tertiary Care Centre in Southern India

Background and objectives: With 2.2 million new cases every year, Tuberculosis (TB) continues to be an epidemic of large proportions in India. Conventional direct sputum smear microscopy, though limited in its sensitivity, is still the most common method of testing for TB. Newer techniques such as concentrated sputum microscopy, have shown some promise in improving this limited sensitivity. We have compared the efficacy of concentrated sputum versus the direct smear technique in 1000 sputum samples of patients suspected to be suffering from TB. Methods: A total of 1000 sputum specimens were collected for direct acid-fast bacilli (AFB) smear, concentrated AFB smear and culture from St. John’s Medical College and Hospital. 39 contaminated samples were (3.9%) omitted during the final analysis. Mycobacterial culture was used as the reference standard method for the detection of TB. Results: 184 and 198 of the 961 samples were found to AFB positive by direct smear microscopy and concentrated smear technique respectively. The measured sensitivity and specificity of direct smear microscopy were 69.86% and 95.82%, while that of concentrated smear microscopy was 76.71% and 95.96 % respectively. 33 samples found to be negative by the direct smear method turned out to be positive by the concentrated smear technique. Conclusions: Though our study suggests no significant statistical difference between the two techniques of detecting pulmonary tuberculosis, we recommend the use of the concentrated technique in centres such as ours, where facilities are already in place. In this way, the number of cases of TB that remain untreated may significantly come down.

Emerging Infectious Disease Implications of Invasive Mammalian Species: The Greater White-Toothed Shrew (Crocidura russula) Is Associated With a Novel Serovar of Pathogenic Leptospira in Ireland.

The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira.

Plasma Total Antioxidant Capacity and Activities of Blood Glutathione Peroxidase and Superoxide Dismutase Determined in Healthy Dogs by Using Commercially Available Kits

Abstract Data on the values of selected blood antioxidant parameters, i.e. total antioxidant capacity, glutathione peroxidase, and superoxide dismutase in healthy dogs, are lacking. There are no published accepted standard reference methods for their determination. The aim of this study was to determine the values of plasma total antioxidant capacity and the activities of whole blood glutathione peroxidase and erythrocyte superoxide dismutase in 30 healthy client-owned dogs (19 females, 11 males). The effect of age and sex on the measured antioxidant parameters was also investigated. Antioxidant parameters were determined with an automated biochemical analyser, using the commercially available Randox kits. No significant difference in age, weight, and antioxidant parameters was determined between females and males. A significant positive effect of age (p = 0.002, r2 = 0.284) on superoxide dismutase activity was confirmed. There was no effect of sex on any of the antioxidant parameters measured. However, we observed a tendency of the effect of sex (p = 0.063, r2 = 0.118), as well as age (p = 0.073, r2 = 0.111), on the activity of glutathione peroxidase. Our results are in part comparable with the results of other studies in which the same types of methods and samples were used to determine antioxidant parameters. In conclusion, the sex and age of dogs should be taken into consideration when planning a study on antioxidant status parameters.

Assessment of air quality microsensors versus reference methods: The EuNetAir joint exercise

The 1st EuNetAir Air Quality Joint Intercomparison Exercise organized in Aveiro (Portugal) from 13th–27th October 2014, focused on the evaluation and assessment of environmental gas, particulate matter (PM) and meteorological microsensors, versus standard air quality reference methods through an experimental urban air quality monitoring campaign. The IDAD-Institute of Environment and Development Air Quality Mobile Laboratory was placed at an urban traffic location in the city centre of Aveiro to conduct continuous measurements with standard equipment and reference analysers for CO, NOx, O3, SO2, PM10, PM2.5, temperature, humidity, wind speed and direction, solar radiation and precipitation.The comparison of the sensor data generated by different microsensor-systems installed side-by-side with reference analysers, contributes to the assessment of the performance and the accuracy of microsensor-systems in a real-world context, and supports their calibration and further development.The overall performance of the sensors in terms of their statistical metrics and measurement profile indicates significant differences in the results depending on the platform and on the sensors considered. In terms of pollutants, some promising results were observed for O3 (r2: 0.12–0.77), CO (r2: 0.53–0.87), and NO2 (r2: 0.02–0.89). For PM (r2: 0.07–0.36) and SO2 (r2: 0.09–0.20) the results show a poor performance with low correlation coefficients between the reference and microsensor measurements. These field observations under specific environmental conditions suggest that the relevant microsensor platforms, if supported by the proper post processing and data modelling tools, have enormous potential for new strategies in air quality control.

A framework for automatic creation of gold-standard rigid 3D-2D registration datasets.

Advanced image-guided medical procedures incorporate 2D intra-interventional information into pre-interventional 3D image and plan of the procedure through 3D/2D image registration (32R). To enter clinical use, and even for publication purposes, novel and existing 32R methods have to be rigorously validated. The performance of a 32R method can be estimated by comparing it to an accurate reference or gold standard method (usually based on fiducial markers) on the same set of images (gold standard dataset). Objective validation and comparison of methods are possible only if evaluation methodology is standardized, and the gold standard dataset is made publicly available. Currently, very few such datasets exist and only one contains images of multiple patients acquired during a procedure. To encourage the creation of gold standard 32R datasets, we propose an automatic framework. The framework is based on rigid registration of fiducial markers. The main novelty is spatial grouping of fiducial markers on the carrier device, which enables automatic marker localization and identification across the 3D and 2D images. The proposed framework was demonstrated on clinical angiograms of 20 patients. Rigid 32R computed by the framework was more accurate than that obtained manually, with the respective target registration error below 0.027mm compared to 0.040mm. The framework is applicable for gold standard setup on any rigid anatomy, provided that the acquired images contain spatially grouped fiducial markers. The gold standard datasets and software will be made publicly available.

Abstract PR610

Background & Objectives: Anaesthesia alters normal body thermoregulation control leading to perioperative hypothermia. Monitoring intra-operative body temperature is frequently reinforced and can be achieved with various methods. We performed a correlation study between infrared tympanic membrane temperature (TMT) and nasopharyngeal temperature (NT) to the core oesophageal temperature (OT). Materials & Methods: Seventy seven patients aged 18 to 60 years requiring general anaesthesia with endotracheal intubation was recruited. A set of three temperatures (TMT, NT and OT) were taken after induction, at one hour and at the second hour intraoperatively on each patient. Bland-Altman plots were utilized to assess agreement of temperatures, with the OT taken as the reference or gold standard method. Results: The mean TMT, NT and OT were 36.84 ± 0.45 °C, 36.24 ± 0.50 °C and 36.20 ± 0.48 °C respectively. The correlation (r) between TMT with OT was 0.819 (p<0.0001), NT with OT was 0.911 (p<0.0001) and NT with TMT was 0.773 (p<0.0001). The mean difference (bias) between NT and OT was found to be -0.064° C with 95% limits of agreement (LOA) of -0.467 to 0.34° C and SD ± 0.40. The mean difference between TMT and OT was found to be -0.023° C with 95% LOA of -0.577 to 0.531° C and SD ± 0.55. The agreement between TMT and OT was outside the acceptable limits of ± 0.5° C via a Bland-Altman plot. The agreement between NT and OT was within acceptable limits at ± 0.40° C. Conclusion: NT showed a higher correlation with OT, although both NT and TMT had strong positive correlations with OT measurement. NT measurement also accurately reflects the lower OT. Our study supports the use of NT monitoring as a simpler and less invasive method to measure the core body temperature.

The use of finger-stick blood to assess lactate in critically ill surgical patients

BackgroundUsing finger-stick capillary blood to assess lactate from the microcirculation may have utility in treating critically ill patients. Our goals were to determine how finger-stick capillary lactate correlates with arterial lactate levels in patients from the surgical intensive care unit, and to compare how capillary and arterial lactate trend over time in patients undergoing resuscitation for shock.MethodsCapillary whole blood specimens were obtained from finger-sticks using a lancet, and assessed for lactate via a handheld point-of-care device as part of an “investigational use only” study. Comparison was made to arterial blood specimens that were assessed for lactate by standard laboratory reference methods.Results40 patients (mean age 68, mean APACHEII 18, vasopressor use 62%) were included. The correlation between capillary and arterial lactate levels was 0.94 (p < 0.001). Capillary lactate measured slightly higher on average than paired arterial values, with a mean difference 0.99 mmol/L. In patients being resuscitated for septic and hemorrhagic shock, capillary and arterial lactate trended closely over time: rising, peaking, and falling in tandem. Clearance of capillary and arterial lactate mirrored clinical improvement, normalizing in all patients except two that expired.ConclusionFinger-stick capillary lactate both correlates and trends closely with arterial lactate in critically ill surgical patients, undergoing resuscitation for shock.

A facile method to evaluate the quality of Platycodon grandiflorum A. De Candolle using reference standard extract

Platycodi Radix, the root of Platycodon grandiflorum A. De Candolle, is a widely used functional food in East Asia. Reference standard extract, a mixture of marker compounds, is used as a reference substance to quantify platycosides from Platycodi Radix. The convenience and consistency of using reference standard extract as a reference substance was evaluated. The qualitative and quantitative results of platycoside contents in Platycodi Radix characterized by this method were compared with that characterized by the conventional external standards method. The Pearson correlation coefficient test of these two methods was between 0.985 and 0.999. A more comprehensive chemical information including relative retention time, relative peak area and contents of active components were obtained simultaneously from raw material using reference standard extract method. The application of this method may relieve the stress in increasing demands for pure marker compounds.

Can we trust visual methods alone for detecting caries in teeth?

Data sourcesElectronic Databases searched in PubMed, Embase and Scopus. Unpublished literature was traced through OpenSIGLE, annals of IADR/AADR (International and American Associations for Dental Research) and ORCA (European Organisation for Caries Research) from 2003-2014. Studies were limited to English.Study selectionStudies involving visual inspection for detection of primary coronal caries lesions in primary or permanent human teeth were considered. All papers needed to include a clearly defined reference standard and the reporting of absolute numbers of true positives, false positives, true negatives and false negatives or a presentation of sufficient data to calculate these figures. Reference methods considered appropriate were histologic evaluation, operative intervention, direct visual inspection after temporary tooth separation and radiography. For studies with the same data set only the most complete study was included. Articles that reported caries detection using artificial caries, root caries or recurrent decay adjacent to restorations were excluded.Data extraction and synthesisStudy selection for inclusion was performed independently by two reviewers and disagreements were resolved by discussion with a third reviewer. Data were collected by two reviewers on structured tables. Discrepancies were resolved by consensus. A meta-analysis was performed. The following information was extracted; reference standard method, setting (clinical or laboratory), type of teeth (primary or permanent), surface evaluated (smooth, proximal or occlusal), sample size, examiner's experience. Also recorded were visual scoring systems. Studies that did not report any criteria were classified as 'with no criteria'. If authors used criteria with no reference to previously published studies they were classified as 'own criteria'. The PRISMA guideline was followed to report the review and the QUADAS-2 checklist (Quality assessment of studies of diagnostic performance included in systematic reviews) was used to assess the risk of bias of the included studies.ResultsData were used to calculate the pooled sensitivity, specificity, diagnostic odds ratio and summary receiver operating characteristics curve. Heterogeneity of the studies was also assessed. A total of 102 manuscripts and one abstract were included. The analysis demonstrated that the visual method had good accuracy for detecting carious lesions. Clinically obtained specificity was higher. Also observed was moderate to high heterogeneity and evidence of publication bias. Studies employing well known visual scoring systems were significantly more accurate than those that used their own criteria. The results were grouped and differentiate the type of dentition (permanent or primary), type of lesion (initial or advanced), proximal or occlusal surface and clinical settings from laboratory settings.The pooled specificity calculated was high in most of the groups and ranged from 0.573 to 0.992 mostly > 0.90; the lowest was in the occlusal initial caries lesions in primary teeth.The sensitivity ranged from 0.274 to 0.77; the lowest from clinical studies in proximal surfaces in permanent teeth, the highest from three studies evaluating the occlusal initial caries lesions in permanent teeth. Most of the pooled sensitivities were around a low level.ConclusionsVisual caries detection method has good overall performance. Although the studies together had high heterogeneity and risk of bias, the use of detailed and validated indices seems to improve the accuracy of the method.

Cost of speed: A practical approach to evaluate a screening method from a Bayesian perspective

Utilization of rapid screening method presents an investment decision of laboratory assets. Screening methods are filtering procedures implemented to enable analysis of a large volume of samples in a rapid fashion. The principle of screening includes establishment of a threshold value as a selection criteria for the follow up confirmative analysis. Selection of a quality screening method determines the optimized utilization of laboratory resources. Two mathematical models are used to evaluate a screening method by directly comparing to a gold standard reference method. The first model utilizes the traditional receiver operating characteristic (ROC) curve model to evaluate the screening method. A new model is proposed to access the accuracy and reliability of the screening method based on the gold standard reference method. The two models are extremely practical for a single laboratory to evaluate the reliability of a screening method when limited resources are available.

Bordetella trematum sepsis with shock in a diabetic patient with rapidly developing soft tissue infection

Bordetella is a gram-negative, glucose non-fermenting bacillus, consisting of many host-associated species. B. trematum has previously been identified in wound infections, but rarely known to be a source of bacteremia. Currently, 16S rRNA sequencing represents the reference standard method by which identification is made. Herein, we present a case of fatal B. trematum bacteremia with septic shock. The presumed primary site of the infection was a rapidly developing left leg deep soft tissue infection without necrotizing fasciitis. B. trematum should now be considered as a significant pathogen in sepsis.

Autoimmune pancreatitis: An update

Autoimmune pancreatitis (AIP) is a rare disease, the pathophysiological understanding of which has been greatly improved over the last years. The most common form, type 1 AIP belongs to the IgG4-related diseases and must be distinguished from type 2 AIP, which is a much rarer entity associated with chronic inflammatory bowel disease. Clinically, there is an overlap with pancreatic cancer. Imaging and further criteria, such as serological and histological parameters are utilized for a differentiation between both entities in order to select the appropriate therapy and to avoid the small but ultimately unnecessary number of pancreatectomies. The diagnostics of AIP are complex, whereby the consensus criteria of the International Association of Pancreatology have become accepted as the parameters for discrimination. These encompass five cardinal criteria and one therapeutic criterion. By applying these criteria AIP can be diagnosed with a sensitivity of 84.9%, a specificity of 100% and an accuracy of 93.8%. The diagnosis of AIP is accomplished by applying several parameters of which two relate to imaging. As for the routine diagnostics of the pancreas these are ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). Important for the differential diagnosis is the exclusion of signs of local and remote tumor spread for which CT and MRI are established. The essential diagnostic parameter of histology necessitates sufficient sample material, which cannot usually be acquired by a fine needle biopsy. CT or MRI are the reference standard methods for identification of the optimal puncture site and imaging-assisted (TruCut) biopsy. In patients presenting with unspecific upper abdominal pain, painless jaundice combined with the suspicion of a pancreatic malignancy in imaging but a mismatch of secondary signs of malignancy, AIP should also be considered as a differential diagnosis. As the diagnosis of AIP only partially relies on imaging radiologists also have to be aware of the clinical, serological and histological parameters for AIP in order to guide clinicians towards the correct diagnosis. Only in this way can the highly efficient steroid therapy be initiated and otherwise possibly severe forms of therapy be avoided.

Simultaneously Determination Of Six Phenolic Acids In Cardiotonic Pills By Using Single Standard Quantification Method

Cardiotonic Pill (CP) is widely used in the treatment of cardiovascular disease. However, the quality control of this preparation is restricted by the deficiency of reference standards. The aim of this study is to establish a single standard quantification method (SSQM) to determine six phenolic acids in CP simultaneously by using ultra-performance liquid chromatography [1]. A quantitative approach based on the analytical hierarchy process (AHP) was utilized to select the ideal single reference standard during method development. Protocatechuicaldehyde was considered as the ideal single standard. The conversion factors between single standard and other analytes, i.e. danshensu, rosmarinic acid, lithospermic acid, salvianolic acid B and salvianolic acid A, were 6.57, 1.51, 3.44, 3.65 and 1.51, respectively. This method shows good precision, accuracy, repeatability and reproducibility in validation experiments. The result obtained using SSQM is consistent with those from external reference standard method [2]. This SSQM is expected to be a useful and efficient tool for the quality control of phenolic compounds in CP. Acknowledgement: This work was supported by National Key Special Project of Science and Technology for Innovation Drug of China (Grant No. 2013ZX09402202). Reference: [1] J.J. Hou, W.Y. Wu, et al. (2011)J. Chromatogr. A 1218:5618 – 5627. [2] L.Y. Bo, T.E. Kipletting, et al. (2013) Anal. Methods 5:3741 – 3746.

Portable A-Mode Ultrasound for Body Composition Assessment in Adolescents.

Ultrasound (US) imaging is a low-cost, highly feasible alternative method for monitoring the nutritional status of a population; however, only a few studies have tested the body composition agreement between US and reference standard methods, especially in adolescents. The purposes of this study were to assess the agreement of portable US with a reference standard method, dual-energy x-ray absorptiometry (DXA), for body fat percentage (BF%) in adolescents and to verify whether the use of a new mathematical model, based on the anatomic thickness obtained by US, is capable of improving BF% prediction. This research was a descriptive study. Measures of total body mass, BF% on DXA, and BF% on US were collected from 105 adolescents. The participants included 71 male adolescents (median age ± interquartile range, 14.0 ± 2.0 years) and 34 female adolescents (13.0 ± 2.3 years). Ultrasound yielded significantly lower BF% values than DXA for male (mean ± SD, US, 9.6% ± 6.6%; DXA, 20.0% ± 7.2%; R= 0.848; P< .05) and female (US, 22.5% ± 5.7%; DXA, 30.3% ± 4.9%; R = 0.495; P < .05) participants. In addition, Bland-Altman analysis showed low concordance. When a multivariate regression was tested, the results improved for both sexes (US, 20.3% ± 4.6%; R= 0.848; P= .503) and female participants (US, 29.0% ± 5.7%; R = 0.712; P = .993) with a standard estimate of error of 1.57%. This study has shown that US applied in a specific regression for BF% prediction in adolescents has a strong correlation with DXA as well as concordance with Bland-Altman analysis.

Method Modification Study for the Thermo Scientific SureTect™ Listeria Species Assay-Matrix Extension.

The Thermo Scientific™ SureTect™ Listeria species assay is a new real-time PCR assay for the detection of all species of Listeria in food and environmental samples. The assay was originally certified as Performance Tested Methods(SM) (PTM) 071304 in 2013. This report details the method modification study undertaken to extend the performance claims of the assay for matrixes of raw ground turkey, raw ground pork, bagged lettuce, raw pork sausages, pasteurized 2% fat milk, raw cod, pasteurized brie cheese, and ice cream. The method modification study was conducted using the AOAC Research Institute (RI) PTM program to validate the SureTect PCR assay in comparison to the reference method detailed in ISO 11290-1:1996 including amendment 1:2004. All matrixes were tested by Thermo Fisher Scientific (Basingstoke, United Kingdom). In addition, three matrixes (raw cod, bagged lettuce, and pasteurized brie cheese) were analyzed independently as part of the AOAC RI-controlled independent laboratory study by the University of Guelph, Canada. Using probability of detection statistical analysis, there was no significant difference in the performance between the SureTect assay and the International Organization for Standardization reference method for any of the matrixes analyzed in this study.