Assessment of Blood and Semen Detection and DNA Collection from Swabs up to Three Months after Deposition on Five Different Cloth Materials.

Body fluid identification plays a crucial role in criminal investigations. Because of their presence in many cases, blood and semen are the most relevant body fluids in forensic sciences. Based on antigen-antibody reactions binding unique proteins for each body fluid, serological assays represent one of the most rapid and highly specific tests for blood and semen. Currently, few studies have assessed the factors affecting body fluid identification by applying these assays. This work aimed to study the effect of different fabrics from clothes and time since deposition on identification through immunochromatographic tests for blood and semen, DNA isolation, and STR profiling from these samples. Body fluids were deposited on black- and white-dyed denim and cotton fabrics, and on leather. Afterward, blood and semen were sampled at 1 day, 30 days, and 90 days after deposition and identified by using the SERATEC® HemDirect Hemoglobin Test and the PSA Semiquant and SERATEC® BLOOD CS and SEMEN CS tests, respectively. Laboratory and crime scene tests presented similar performances for the detection of blood and semen stains on every tested fabric. No differences were found on band intensities between timepoints for all fabrics. It was possible to recover and identify blood and semen samples up to three months after deposition and to obtain full STR profiles from all the tested fabrics. Both body fluid STR profiles showed differences in their quality between 1 and 90 days after deposition for all fabrics except for black cotton for semen samples. Future research will expand the results, assessing body fluid identification on other substrates and under different environmental conditions.

Recent Advances in Gas Detection Methodologies with a Special Focus on Environmental Sensing and Health Monitoring Applications─A Critical Review.

With the expansion of the Internet-of-Things (IoT), the use of gas sensors in the field of wearable technology, smart devices, and smart homes has increased manifold. These gas sensors have two key applications─one is the detection of gases present in the environment and the other is the detection of Volatile Organic Compounds (VOCs) that are found in the breath. In this review, we focus systematically on the advancements in the field of various spectroscopic methods such as mass spectrometry-based analysis and point-of-care approach to detect VOCs and gases for environmental monitoring and disease diagnosis. Additionally, we highlight the development of smart sensors that work on the principle of electrochemical detection and provide examples of the same through an extensive literature review. At the end of this review, we highlight various challenges and future perspectives.

Direct analysis in real-time tandem mass spectrometry method for the rapid screening of 11 new psychoactive substances in blood and urine.

RATIONALE: With the continuous renewal of new psychoactive substances (NPS), the abuse of NPS has seriously harmed social security and public safety. The number of deaths from the abuse of NPS is increasing year by year. Therefore, there is an immediate need to develop an effective method for detecting NPS. METHODS: Direct analysis in real-time tandem mass spectrometry (DART-MS/MS) was used to detect 11 NPS in blood and urine. The temperature of the ion source was optimized and set to 400°C. The mixture solvent of acetonitrile/methanol (4:1, v/v) was used as the precipitant. SKF-525 (2-(diethylamino)ethyl 2,2-diphenylpentanoate) was selected as the internal standard for quantification. After the pretreatment of the analytes in blood or urine, the supernatant was prepared for instrumental analysis. RESULTS: The results indicated that the correlation coefficients (r2 ) of all analytes ranged from 0.99 to 1 in the linear range. The recoveries of 11 analytes at three spiked levels ranged between 83.4% and 110.4% in blood and between 81.7% and 108.5% in urine. The matrix effects of 11 analytes ranged between 79.5% and 109.5% in blood and between 85.0% and 109.4% in urine. The relative standard deviations of intra-day and inter-day precisions and repeatability were lower than 12.4%, 14.1%, and 14.3% in blood and lower than 11.4%, 13.9%, and 14.3% in urine, respectively. CONCLUSION: The method established for the detection of 11 NPS could meet the needs for the rapid screening of NPS samples. The DART-MS/MS method has the advantages of being efficient, fast, and green. Therefore, it may become a promising technology for the detection of NPS in the future.

Assessment of wastewater-borne pharmaceuticals in tissues and body fluids from riverine fish.

Riverine fish in densely populated areas is constantly exposed to wastewater-borne contaminants from effluent discharges. These can enter the organism through the skin, gills or by ingestion. Whereas most studies assessing the contaminant burden in exposed fish have focused either on muscle or a limited set of tissues. Here we set out to generate a more comprehensive overview of the distribution of pollutants across tissues by analyzing a panel of matrices including liver, kidney, skin, brain, muscle, heart, plasma and bile. To achieve a broad analyte coverage with a minimal bias towards a specific contaminant class, sample extracts from four fish species were analyzed by High-Performance Liquid Chromatography (HPLC) - high-resolution mass spectrometry (HRMS) for the presence of 600 wastewater-borne pharmaceutically active compounds (PhACs) with known environmental relevance in river water through a suspect-screening analysis. A total of 30 compounds were detected by suspect screening in at least one of the analyzed tissues with a clear prevalence of antidepressants. Of these, 15 were detected at confidence level 2.a (Schymanski scale), and 15 were detected at confidence level 1 following confirmation with authentic standards, which furthermore enabled their quantification. The detected PhACs confirmed with level 1 of confidence included acridone, acetaminophen, caffeine, clarithromycin, codeine, diazepam, diltiazem, fluoxetine, ketoprofen, loratadine, metoprolol, sertraline, sotalol, trimethoprim, and venlafaxine. Among these substances, sertraline stood out as it displayed the highest detection frequency. The values of tissue partition coefficients for sertraline in the liver, kidney, brain and muscle were correlated with its physicochemical properties. Based on inter-matrix comparison of detection frequencies, liver, kidney, skin and heart should be included in the biomonitoring studies of PhACs in riverine fish.

Effect of simulated body fluid formulation on orthopedic device apatite-forming ability assessment.

Integration of native bone into orthopedic devices is a key factor in long-term implant success. The material-tissue interface is generally accepted to consist of a hydroxyapatite layer so bioactive materials that can spontaneously generate this hydroxyapatite layer after implantation may improve patient outcomes. Per the ISO 22317:2014 standard, "Implants for surgery - In vitro evaluation for apatite-forming ability of implant materials," bioactivity performance statements can be assessed by soaking the material in simulated body fluid (SBF) and evaluating the surface for the formation of a hydroxyapatite layer; however, variations in test methods may alter hydroxyapatite formation and result in false-positive assessments. The goal of this study was to identify the effect of SBF formulation on bioactivity assessment. Bioglass® (45S5 and S53P4) and non-bioactive Ti-6Al-4V were exposed to SBF formulations varying in calcium ion and phosphate concentrations as well as supporting ion concentrations. Scanning electron microscopy and X-ray powder diffraction evaluation of the resulting hydroxyapatite layers revealed that SBF enriched with double or quadruple the calcium and phosphate ion concentrations increased hydroxyapatite crystal size and quantity compared to the standard formulation and can induce hydroxyapatite crystallization on surfaces traditionally considered non-bioactive. Altering concentrations of other ions, for example, bicarbonate, changed hydroxyapatite induction time, quantity, and morphology. For studies evaluating the apatite-forming ability of a material to support bioactivity performance statements, test method parameters must be adequately described and controlled. It is unclear if apatite formation after exposure to any of the SBF formulations is representative of an in vivo biological response. The ISO 23317 standard test method should be further developed to provide additional guidance on apatite characterization and interpretation of the results.

A comparison of the analysis of 3 types of body fluids using the XN-350 hematology analyzer versus light microscopy assessment.

ABSTRACT: We evaluated the capacity of the XN-350 instrument to analyze 3 different types of body fluid samples under "body fluid mode."The performance of XN-350 was evaluated in terms of precision, carryover, limit of blank, limit of detection, limit of quantification, and linearity. Cell enumeration and differential data produced by the XN-350 were compared to manual chamber counting results in 63 cerebrospinal fluid (CSF), 51 ascitic fluid, and 51 pleural fluid (PF) samples. Comparisons between XN-350 versus Cytospin data were also performed in PF samples.The precision, carry-over, limit of blank, and linearity of the XN-350 were acceptable. The limits of detection for white blood cells (WBCs) and red blood cells were 1.0/µL, and 1,000.0/µL, respectively; the corresponding limits of quantitation (LOQs) were 5.0/µL and 2,000.0/µL, respectively. The XN-350's cell enumeration and differential counting correlated well with those of manual chamber counting for all 3 sample types (except for differential counting in CSF samples), particularly parameters involving monocytes (r = 0.33) and mononuclear cells (MO- body fluid [BF]; r = 0.26), as well as total cell (TC-BF) enumeration (r = 0.50) and WBC-BF (r = 0.50) in PF samples. The MO-BF in CSF samples differed significantly from manual chamber counting results, but neither TC-BF nor WBC-BF in PF samples did. The XN-350 also showed good correlations with Cytospin analyses for differential counting of neutrophils, lymphocytes, and monocytes in PF samples. The differential counting of eosinophils via the XN-350 and Cytospin were not significantly correlated, but the difference between them was not significant.The XN-350 is an acceptable alternative to manual fluid analysis. Samples with low cellularity around the LOQ should be checked manually. Moreover, manual differential counting should be performed on CSF samples, particularity those with low cell numbers.

Recombinant extracellular vesicles as biological reference material for method development, data normalization and assessment of (pre-)analytical variables.

The diagnostic and therapeutic use of extracellular vesicles (EV) is under intense investigation and may lead to societal benefits. Reference materials are an invaluable resource for developing, improving and assessing the performance of regulated EV applications and for quantitative and objective data interpretation. We have engineered recombinant EV (rEV) as a biological reference material. rEV have similar biochemical and biophysical characteristics to sample EV and function as an internal quantitative and qualitative control throughout analysis. Spiking rEV in bodily fluids prior to EV analysis maps technical variability of EV applications and promotes intra- and inter-laboratory studies. This protocol, which is an Extension to our previously published protocol (Tulkens et al., 2020), describes the production, separation and quality assurance of rEV, their dilution and addition to bodily fluids, and the detection steps based on complementary fluorescence, nucleic acid and protein measurements. We demonstrate the use of rEV for method development, data normalization and assessment of pre-analytical variables. The protocol can be adopted by researchers with standard laboratory and basic EV separation/characterization experience and requires ~4-5 d.

Developing a Low-Cost, Simple-to-Use Electrochemical Sensor for the Detection of Circulating Tumour DNA in Human Fluids.

It is well-known that two major issues, preventing improved outcomes from cancer are late diagnosis and the evolution of drug resistance during chemotherapy, therefore technologies that address these issues can have a transformative effect on healthcare workflows. In this work we present a simple, low-cost DNA biosensor that was developed specifically to detect mutations in a key oncogene (KRAS). The sensor employed was a screen-printed array of carbon electrodes, used to perform parallel measurements of DNA hybridisation. A DNA amplification reaction was developed with primers for mutant and wild type KRAS sequences which amplified target sequences from representative clinical samples to detectable levels in as few as twenty cycles. High levels of sensitivity were demonstrated alongside a clear exemplar of assay specificity by showing the mutant KRAS sequence was detectable against a significant background of wild type DNA following amplification and hybridisation on the sensor surface. The time to result was found to be 3.5 h with considerable potential for optimisation through assay integration. This quick and versatile biosensor has the potential to be deployed in a low-cost, point-of-care test where patients can be screened either for early diagnosis purposes or monitoring of response to therapy.

Assessment of strategies for the formation of stable suspensions of titanium dioxide nanoparticles in aqueous media suitable for the analysis of biological fluids.

Due to their omnipresence in consumer products, there is a growing concern about the potential effects of nanoparticles on human health. Toxicological assessment and NP end-product studies require proper quantification of these materials in biological fluids. However, their quantifications in these media require stable predispersed NP solutions in aqueous media to enable the fortification in the matrices of interest or the preparation of calibration standards. In this study, a sample preparation scheme was developed by studying various dispersion media (polyvinylpyrrolidone and polyethylene glycol) and sonication strategies (bath and ultrasonic probe) to ensure homogeneous dispersion of titanium dioxide nanoparticles. Optimization of the various parameters was performed using SRM NIST 1898 NP reference material, composed of rutile and anatase phases. Number-based size distribution for titanium dioxide NPs was determined by dynamic light scattering and single-particle inductively coupled plasma mass spectrometry to evaluate the procedure efficiency. Changes in mean size and most frequent size distribution were also studied to determine if the agglomeration of nanoparticles occurs at the various dispersion conditions tested. Among the different dispersion parameters tested herein, the use of polyvinylpyrrolidone combined with a sonication process generated by a probe leads to a significant improvement in terms of suspension efficiency and stability over 72 h. The dispersion efficiency of the proposed methodology was assessed by single-particle inductively coupled plasma mass spectrometry with spiked biological fluids such as urine and blood. Graphical abstract.

A rapid and low-cost fabrication and integration scheme to render 3D microfluidic architectures for wearable biofluid sampling, manipulation, and sensing.

The large-scale deployment of wearable bioanalytical devices for general population longitudinal monitoring necessitates rapid and high throughput manufacturing-amenable fabrication schemes that render disposable, low-cost, and mechanically flexible microfluidic modules capable of performing a variety of bioanalytical operations within a compact footprint. The spatial constraints of previously reported wearable bioanalytical devices (with microfluidic operations confined to 2D), their lack of biofluid manipulation capability, and the complex and low-throughput nature of their fabrication process inherently limit the diversity and frequency of end-point assessments and prevent their deployment at large scale. Here, we devise a simple, scalable, and low-cost "CAD-to-3D Device" fabrication and integration scheme, which renders 3D and complex microfluidic architectures capable of performing biofluid sampling, manipulation, and sensing. The devised scheme is based on laser-cutting of tape-based substrates, which can be programmed at the software-level to rapidly define microfluidic features such as a biofluid collection interface, microchannels, and VIAs (vertical interconnect access), followed by the vertical assembly of pre-patterned layers to realize the final device. To inform the utility of our fabrication scheme, we demonstrated three representative devices to perform sweat collection (with visualizable secretion profile), sample filtration, and simultaneous biofluid actuation and sensing (using a sandwiched-interface). Our devised scheme can be adapted for the fabrication and manufacturing of current and future wearable bioanalytical devices, which in turn will catalyze the large-scale production and deployment of such devices for general population health monitoring.

Risk Assessment for Preterm Delivery using the Fetal Fibronectin Test Associated with the Measurement of Uterine Cervix Length in Symptomatic Pregnant Women.

OBJECTIVE: To analyze the use of the measurement of uterine cervix length (MUCL) and the fetal fibronectin (fFN) rapid test as predictors of preterm delivery (PTD) in symptomatic pregnant women assisted at the Santa Casa de Misericórdia de Sobral Maternity Hospital. METHODS: This was a prospective and analytic study involving 53 parturients assisted between September of 2015 and July of 2016; the participants were between 24 and 34 weeks of gestational age (GA) and presented complaints related to preterm labor (PTL) prodromes. Vaginal secretion was collected for fFN testing, and the MUCL was obtained via transvaginal ultrasonography. RESULTS: A total of 58.49% of the subjects showed MUCL < 25 mm, and 41.51% were positive in the fFN rapid test. A total of 48 patients were followed-up until their delivery date, and 54.17% resulted in PTL. The relative risk (RR) for PTD in patients with MUCL < 25 mm was 1.83 (p = 0.09, 0.99-3.36, 95% confidence interval [CI]), with a mean time before delivery of 2.98 weeks. Based on fFN positive results, the RR was 3.50 (p = 0.002, 1.39-8.79, 95%CI) and the mean time until delivery was 1.94 weeks. The RR was 2.70 (p = 0.002, 1.08-6.72, 95%CI) when both tests were used. The RR of PTD within 48 hours, and 7 and 14 days were, respectively, 1.30 (p = 0.11, 95% CI 1.02-1.67), 1.43 (p = 0.12, 95% CI % 0.99-2.06), and 2.03 (p = 0.008, 95% CI 1.26-3.27), when based on the MUCL, and 1.75 (p = 0.0006, 95% CI 1.20-2.53), 2.88 (p = 0.0001, 95% CI, 1.57-5.31), and 3.57 (p = 0.0002, 95% CI 1.63-7.81) when based on positive fFN results. The RR at 48 hours and 7 and 14 days considering both tests was 1.74 (p = 0.0001, 95% CI 1.14-2.64), 2.22 (p = 0.0001, 95% CI 1.22-4.04), and 2.76 (p = 0.0002, 95% CI 1.27-5.96), respectively. CONCLUSION: In symptomatic pregnant women, we concluded that the MUCL < 25 mm associated with positive fFN rapid test indicate increased the risk for PTD. Further studies with larger sample sizes could contribute in supporting the results presented in the current study.

OBJETIVO: Analisar a utilização da medida do comprimento do colo uterino (MCCU), e do teste da fibronectina fetal (FNf) como preditores do trabalho de parto pré-termo (PPT), em gestantes sintomáticas, atendidas na Maternidade da Santa Casa de Misericórdia de Sobral. MéTODOS: Foi realizado um estudo prospectivo e analítico, envolvendo 53 parturientes atendidas no período de setembro de 2015 a julho de 2016, com idade gestacional (IG) entre 24 e 34 semanas que tiveram queixas relacionadas a pródromos de trabalho de parto prematuro (TPP), sendo realizada coleta de secreção vaginal para FNf e MCCU por via ultrassonográfica transvaginal. RESULTADOS: Um total de 58,49% das pacientes tinham MCCU < 25 mm, e 41,51% tiveram teste rápido de fFN positivo. Foi feito o acompanhamento de 48 pacientes, com 54,17% de PPTs. O risco relativo (RR) para PPT com MCCU < 25 mm foi de 1,83 (p = 0,09, 0,99­3,36, intervalo de confiança [IC] 95%), com média de tempo até o parto de 2,98 semanas. Para fFN, o RR foi de 3.50 (p = 0.002, 1.39­8.79, IC 95%) e a média até o parto foi de 1,94 semanas. Quando os dois testes foram positivos, o RR foi de 2,70 (1,08­6,72). Para a MCCU, o RR para PPT em 48 horas, 7 e 14 dias foram 1,30 (p = 0.11, 95% IC 1.02­1.67), 1,43 (p = 0.12, 95% CI % 0.99­2.06) e 2,03 (p = 0.008, 95% IC 1.26­3.27), respectivamente. Para FNf, em 48 horas, 7 e 14 dias foi de 1,75 (p = 0.0006, 95% IC 1.20­2.53, 2,88 (p = 0.0001, 95% IC, 1.57­5.31) e 3,57 (p = 0.0002, 95% IC 1.63­7.81) respectivamente. Com os dois testes, o RR em 48 horas, 7 e 14 dias foi 1,74 (p = 0.0001, 95%IC 1.14­2.64), 2,22 (p = 0.0001, 95% IC 1.22­4.04) e 2,76 (p = 0.0002, 95% IC 1.27­5.96) respectivamente. CONCLUSãO: Em mulheres grávidas sintomáticas, concluímos que a MCCU < 25 mm e o teste rápido de FNf positivo indicam aumento do risco de PPT. Outros estudos com tamanhos de amostra maiores podem contribuir para apoiar os resultados apresentados no presente estudo.

Risk assessment for preterm delivery using the fetal fibronectin test associated with the measurement of uterine cervix length in symptomatic pregnant women / Avaliação do risco para parto pré-termo utilizando o teste da fibronectina fetal, associado à medida de comprimento de colo uterino, em gestantes sintomáticas

Abstract Objective To analyze the use of the measurement of uterine cervix length (MUCL) and the fetal fibronectin (fFN) rapid test as predictors of preterm delivery (PTD) in symptomatic pregnant women assisted at the Santa Casa de Misericórdia de Sobral Maternity Hospital. Methods This was a prospective and analytic study involving 53 parturients assisted between September of 2015 and July of 2016; the participants were between 24 and 34 weeks of gestational age (GA) and presented complaints related to preterm labor (PTL) prodromes. Vaginal secretion was collected for fFN testing, and the MUCL was obtained via transvaginal ultrasonography. Results A total of 58.49% of the subjects showed MUCL < 25 mm, and 41.51% were positive in the fFNrapid test.Atotal of 48 patients were followed-up until their delivery date, and 54.17% resulted in PTL. The relative risk (RR) for PTD in patients with MUCL < 25 mm was 1.83 (p = 0.09, 0.99-3.36, 95% confidence interval [CI]), with a mean time before delivery of 2.98 weeks. Based on fFN positive results, the RR was 3.50 (p = 0.002, 1.39- 8.79, 95%CI) and themean time until delivery was 1.94weeks. The RRwas 2.70 (p = 0.002, 1.08-6.72, 95%CI) when both tests were used. The RR of PTD within 48 hours, and 7 and 14 days were, respectively, 1.30 (p = 0.11, 95% CI 1.02-1.67), 1.43 (p = 0.12, 95% CI % 0.99-2.06), and 2.03 (p = 0.008, 95% CI 1.26-3.27), when based on the MUCL, and 1.75 (p = 0.0006, 95% CI 1.20-2.53), 2.88 (p = 0.0001, 95% CI, 1.57-5.31), and 3.57 (p = 0.0002, 95% CI 1.63-7.81) when based on positive fFN results. The RR at 48 hours and 7 and 14 days considering both tests was 1.74 (p = 0.0001, 95% CI 1.14-2.64), 2.22 (p = 0.0001, 95% CI 1.22-4.04), and 2.76 (p = 0.0002, 95% CI 1.27-5.96), respectively. Conclusion In symptomatic pregnant women, we concluded that the MUCL < 25 mm associated with positive fFN rapid test indicate increased the risk for PTD. Further studies with larger sample sizes could contribute in supporting the results presented in the current study.

Resumo Objetivo Analisar a utilização da medida do comprimento do colo uterino (MCCU), e do teste da fibronectina fetal (FNf) como preditores do trabalho de parto pré-termo (PPT), em gestantes sintomáticas, atendidas na Maternidade da Santa Casa de Misericórdia de Sobral. Métodos Foi realizado umestudo prospectivo e analítico, envolvendo 53 parturientes atendidas no período de setembro de 2015 a julho de 2016, com idade gestacional (IG) entre 24 e 34 semanas que tiveram queixas relacionadas a pródromos de trabalho de parto prematuro (TPP), sendo realizada coleta de secreção vaginal para FNf e MCCU por via ultrassonográfica transvaginal. Resultados Um total de 58,49% das pacientes tinham MCCU < 25 mm, e 41,51% tiveram teste rápido de fFN positivo. Foi feito o acompanhamento de 48 pacientes, com 54,17% de PPTs. O risco relativo (RR) para PPT com MCCU < 25 mm foi de 1,83 (p = 0,09, 0,99-3,36, intervalo de confiança [IC] 95%), com média de tempo até o parto de 2,98 semanas. Para fFN, o RR foi de 3.50 (p = 0.002, 1.39-8.79, IC 95%) e a média até o parto foi de 1,94 semanas. Quando os dois testes forampositivos, o RR foi de 2,70 (1,08-6,72). Para a MCCU, o RR para PPT em 48 horas, 7 e 14 dias foram 1,30 (p = 0.11, 95% IC 1.02-1.67), 1,43 (p = 0.12, 95% CI % 0.99-2.06) e 2,03 (p = 0.008, 95% IC 1.26-3.27), respectivamente. Para FNf, em 48 horas, 7 e 14 dias foi de 1,75 (p = 0.0006, 95% IC 1.20-2.53, 2,88 (p = 0.0001, 95% IC, 1.57-5.31) e 3,57 (p = 0.0002, 95% IC 1.63-7.81) respectivamente. Com os dois testes, o RR em 48 horas, 7 e 14 dias foi 1,74 (p = 0.0001, 95%IC 1.14-2.64), 2,22 (p = 0.0001, 95% IC 1.22-4.04) e 2,76 (p = 0.0002, 95% IC 1.27-5.96) respectivamente. Conclusão Em mulheres grávidas sintomáticas, concluímos que a MCCU < 25 mm e o teste rápido de FNf positivo indicam aumento do risco de PPT. Outros estudos com tamanhos de amostra maiores podem contribuir para apoiar os resultados apresentados no presente estudo.

Flow-through dynamic microextraction system for automatic in vitro assessment of chyme bioaccessibility in food commodities.

An automatic flow-through dynamic extraction method is proposed for the first time for in vitro exploration, with high temporal resolution, of the transit of the chyme from the gastric to the duodenal compartment using the Versantvoort's fed-state physiologically relevant extraction test. The flow manifold was coupled on-line to an inductively coupled plasma optical emission spectrometer (ICP OES) for real-time elucidation of the bioaccessible elemental fraction of micronutrients (viz., Cu, Fe and Mn) in food commodities across the gastrointestinal tract. The simulated intestinal and bile biofluid (added to the gastric phase) was successively pumped at 1.0 mL min-1 through a large-bore column (maintained at 37.0 ±â€¯2.0 °C) initially loaded with a weighed amount of linseed (250 mg) using a PVDF filter membrane (5.0 µm pore size) for retaining of the solid sample and in-line filtration of the extracts. The lack of bias (trueness) of the on-line gastrointestinal extraction method coupled to ICP OES was confirmed using mass balance validation following microwave assisted digestion of the residual (non-bioaccessible) elemental fraction. Mass balance validation yielded absolute recoveries spanning from 79 to 121% for the overall analytes and samples. On-line dynamic extraction was critically appraised against batch counterparts for both gastric and gastrointestinal compartments. Due to the lack of consensus in the literature regarding the agitation method for batch oral bioaccessibility testing, several extraction approaches (viz., magnetic stirring, end-over-end rotation and orbital shaking) were evaluated. Improved gastric extractability of Fe along with bioaccessible data comparable to the dynamic counterpart based on the continuous displacement of the extraction equilibrium was obtained with batchwise magnetic stirring, which is deemed most appropriate for ascertaining worst-case/maximum bioaccessibility scenarios.

In vitro assessment of arsenic mobility in historical mine waste dust using simulated lung fluid.

Exposure studies have linked arsenic (As) ingestion with disease in mining-affected populations; however, inhalation of mine waste dust as a pathway for pulmonary toxicity and systemic absorption has received limited attention. A biologically relevant extractant was used to assess the 24-h lung bioaccessibility of As in dust isolated from four distinct types of historical gold mine wastes common to regional Victoria, Australia. Mine waste particles less than 20 µm in size (PM20) were incubated in a simulated lung fluid containing a major surface-active component found in mammalian lungs, dipalmitoylphosphatidylcholine. The supernatants were extracted, and their As contents measured after 1, 2, 4, 8 and 24 h. The resultant As solubility profiles show rapid dissolution followed by a more modest increasing trend, with between 75 and 82% of the total 24-h bioaccessible As released within the first 8 h. These profiles are consistent with the solubility profile of scorodite, a secondary As-bearing phase detected by X-ray diffraction in one of the investigated waste materials. Compared with similar studies, the cumulative As concentrations released at the 24-h time point were extremely low (range 297 ± 6-3983 ± 396 µg L-1), representing between 0.020 ± 0.002 and 0.036 ± 0.003% of the total As in the PM20.

Development of a fast and cost-effective gas chromatography-mass spectrometry method for the quantification of short-chain and medium-chain fatty acids in human biofluids.

The quantification of short-chain and medium-chain fatty acids is becoming more and more relevant in fecal and plasma samples due to their biological impact, which has been associated with colon rectal cancer and fiber consumption. For these reasons, a fast, cost-effective, and reproducible analytical method is highly required. In this research, a gas chromatography-mass spectrometry method based on full scan and multiple reaction monitoring (MRM) acquisition modes were optimized and validated for the analysis of short-chain and medium-chain fatty acids in three biological samples: human fecal water, fecal fermentation supernatants, and human plasma. Several extraction solvents (acidified water, diethyl ether, dichloromethane, ethyl acetate, and methyl tert-butyl ether (MTBE) were further evaluated, demonstrating that the latter was clearly the most suitable solvent with recoveries from 75.4 to 124.4% and coefficient of variations lower than 20%. The applicability of the GC-MS method was tested, for instance, acetic acid was quantified by using samples of plasma and feces from healthy donors at mean values of 66.9 µM and 24.5 mM, respectively. The optimized protocol could successfully find applications within multi-compartment human studies. In parallel, a second pilot experiment on fecal fermentation supernatants indicated that the proposed protocol is suitable to follow the formation of SCFAs during in vitro fermentation by the human gut microbiota. In summary, the present work provided an improved GC-MS method for precise and accurate quantification of SCFAs and MCFAs in human feces and plasma.

A monte carlo study of restricted diffusion: Implications for diffusion MRI of prostate cancer.

PURPOSE: Diffusion MRI is used frequently to assess prostate cancer. The prostate consists of cellular tissue surrounding fluid filled ducts. Here, the diffusion properties of the ductal fluid alone were studied. Monte Carlo simulations were used to investigate ductal residence times to determine whether ducts can be regarded as forming a separate compartment and whether ductal radius could determine the Apparent Diffusion Coefficient (ADC) of the ductal fluid. METHODS: Random walks were simulated in cavities. Average residence times were estimated for permeable cavities. Signal reductions resulting from application of a Stejskal-Tanner pulse sequence were calculated in impermeable cavities. Simulations were repeated for cavities of different radii and different diffusion times. RESULTS: Residence times are at least comparable with diffusion times even in relatively high grade tumors. ADCs asymptotically approach theoretical limiting values. At large radii and short diffusion times, ADCs are similar to free diffusion. At small radii and long diffusion times, ADCs are reduced toward zero, and kurtosis approaches a value of -1.2. CONCLUSIONS: Restricted diffusion in cavities of similar sizes to prostate ducts may reduce ductal ADCs. This may contribute to reductions in total ADC seen in prostate cancer. Magn Reson Med 77:1671-1677, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Assessment of dietary exposure and effect in humans: The role of NMR.

In human nutritional science progress has always depended strongly on analytical measurements for establishing relationships between diet and health. This field has undergone significant changes as a result of the development of NMR and mass spectrometry methods for large scale detection, identification and quantification of metabolites in body fluids. This has allowed systematic studies of the metabolic fingerprints that biological processes leave behind, and has become the research field of metabolomics. As a metabolic profiling technique, NMR is at its best when its unbiased nature, linearity and reproducibility are exploited in well-controlled nutritional intervention and cross-sectional population screening studies. Although its sensitivity is less good than that of mass spectrometry, NMR has maintained a strong position in metabolomics through implementation of standardisation protocols, hyphenation with mass spectrometry and chromatographic techniques, accurate quantification and spectral deconvolution approaches, and high-throughput automation. Thus, NMR-based metabolomics has contributed uniquely to new insights into dietary exposure, in particular by unravelling the metabolic fates of phytochemicals and the discovery of dietary intake markers. NMR profiling has also contributed to the understanding of the subtle effects of diet on central metabolism and lipoprotein metabolism. In order to hold its ground in nutritional metabolomics, NMR will need to step up its performance in sensitivity and resolution; the most promising routes forward are the analytical use of dynamic nuclear polarisation and developments in microcoil construction and automated fractionation.

Translating vibrational spectroscopy into clinical applications - vision or reality?

The Faraday Discussion meeting "Advanced Vibrational Spectroscopy for Biomedical Applications" provided an excellent opportunity to share and discuss recent research and applications on a highly interdisciplinary level. Spectral pathology, single cell analysis, data handling, clinical spectroscopy, and the spectral analysis of biofluids were among the topics covered during the meeting. The focus on discussion rather than "merely" presentation was highly appreciated and fruitful discussions evolved around the interpretation of the amide-bands, optical resolution, the role of diffraction and data analysis procedure, to name a few. The meeting made clear that the spectroscopy of molecular vibrations in biomolecules has evolved from a purely academic research tool to a technology used in clinical practice in some cases. In this sense, biomedical vibrational spectroscopy has reached a pivotal point at which questions like diagnostic value, therapeutic consequence and financial viability are gaining more and more importance.

Physicochemical properties and mineralization assessment of porous polymethylmethacrylate cement loaded with hydroxyapatite in simulated body fluid.

The aim of this study was to evaluate the effect of carboxymethylcellulose (CMC) as a pore generator and hydroxyapatite (HA) as an osteoconductive agent on the physicochemical properties and in-vitro mineralization ability of porous polymethylmethacrylate (PMMA) cement. To this end, various compositions of PMMA cements, which differed in amount of millimeter-sized hydroxyapatite (HA) particles and CMC hydrogel, were prepared and immersed into simulated body fluid (SBF) for 0, 7, 14, 21 and 28 days. It was demonstrated that the incorporation of CMC hydrogel decreased the maximum temperature of cement to the normal body temperature and prolonged the handling time during polymerization. Further, the amount of CMC was responsible for the creation of porosity and interconnectivity, which in turn determined the final mechanical properties of cements. The loaded HA particles enhanced the potential bioactivity of cement for bone ingrowth. Albeit different amount of HA particles influenced their final exposures on the surface of cured cement, all of the three amounts of HA did not weaken the final mechanical properties of cements. The data here suggests that the HA particle loaded porous PMMA cement can serve as the promising candidate for bone reconstruction.