Multimycotoxin Determination in Grains: A Comprehensive Study on Method Validation and Assessment of Effectiveness of Controlled Atmosphere Storage in Preventing Mycotoxin Contamination.

Two simple and low-cost QuEChERS approaches were optimized and validated for multimycotoxin determination in grains by UPLC-MS/MS and applied to assess effectiveness of controlled atmosphere (CA) storage in preventing mycotoxin contamination. Common bean, soybean, and maize samples were stored for 6 months. CA treatments were conducted varying O2 and CO2 partial pressures, temperatures, and moisture contents of the chambers. In the validation study for common bean and maize, 8 out of 11 mycotoxins were successfully validated. For soybean, 10 out of 11 mycotoxins were validated. Aflatoxin B1 was detected in all commodities. Statistical tests suggest that storage temperature played a key role in aflatoxin B1 concentrations in common bean and soybean, but had no influence on maize. Maize was also positive for fumonisins B1 and B2. Differences in fumonisin concentrations were not significant among different treatments. Concentrations of aflatoxin B1 in some samples exceeded legislation's maximum levels. Thus, some of the CA treatments applied were effective in preventing mycotoxin contamination in common bean and soybean but were not effective for maize.

First evaluation of DDT (dichlorodiphenyltrichloroethane) residues and other Persistence Organic Pollutants in soils of Rwanda: Nyabarongo urban versus rural wetlands.

This study was the first to evaluate the occurrence, residue levels, spatial distribution and sources of DDT and other Persistence Organic Pollutants (POPs), which can be found in the Nyabarongo lower catchment (NLC) in Rwanda. These include Aldrin, Dieldrin, Endosulfan, Endrin, Hexachlorocyclohexane (HCH), Heptachlor, Heptachlorepoxide, Hexachlorobenzene (HCB), Isodrin, Methoxychlor, Mirex and Polychlorinated biphenyls (PCBs). A total of 108 soil samples were collected in the wetland area, both extracted and eluted with cyclohexane and analysed by GC-MS. The results indicated that DDT isomers and degradation products were major POPs and were detected in 44 samples (40%). Their detection frequency followed the order of 4,4'-DDE > 4,4' -DDT > 4,4' -DDD > 2,4' -DDT > 2,4' -DDD and 2,4' -DDE. Residues varied from non-detected (nd) to 120 µg kg-1 dry weight (dw), with a mean value of 3.93 µg kg-1 dw and a high variation (SD = 10.17 µg kg-1 dw). The degradation ratios confirmed both the historical and recent application of DDT and Dieldrin (0.53-18 µg kg-1 dw). Other detected POPs included PCBs in Kigali city which ranged from 0.1 to 0.21 µg kg-1 dw, confirming that the old contamination drifted from electric transformers. Aldrin (0.38-0.59 µg kg-1 dw); Heptachlor (0.14-0.19 µg kg-1 dw) residues probably reached the catchment through rain-washout. This study confirms that even though Rwanda banned the use of DDT and other POPs including pesticides (Aldrine, Chlordane, DDT, Dieldrine, Endrine, Heptachlor, Hexachlorobenzene, Mirex, and Toxaphene); Industrial products (Hexachlorobenzene and Polychlorobiphenyl PCBS) and unintentional sub-products, since 2002, some of above products are still used in random areas (e.g: DDT, Dieldrin). The highest residues were detected close to Lake Muhazi and areas surrounding Kigali city. This study recommends full evaluation of human health and ecological risks from exposure to DDT. Additionally, the National Implementation Plan (NIP) for the Stockholm Convention to eliminate POPs should be reinforcement through strengthening the market control and educational programs.

Weight counseling in pediatric hidradenitis suppurativa patients.

BACKGROUND/OBJECTIVES: Hidradenitis suppurativa is a chronic, painful, debilitating disease that may present in the pediatric years. Overweight and obesity are believed to worsen disease severity, but many patients do not receive counseling regarding weight control. The objective of this study is to examine the percentage of hidradenitis suppurativa patients who receive weight counseling as a part of their disease management and which specialties primarily care for these patients. METHODS: We performed a retrospective chart review of pediatric hidradenitis suppurativa patients between January 2011 and October 2018. Demographic data, height, weight, body mass index, body mass index percentiles, number of visits per department, referrals to the Center for Healthy Weight and Nutrition, and referring provider department data were collected. RESULTS: A total of 535 pediatric hidradenitis suppurativa patients were reviewed; 79.6% were female, and the mean age at diagnosis was 14.5 years. 11.6% of patients were overweight, and 54.2% were obese. 32.1% of overweight and obese hidradenitis suppurativa patients received a referral to the Center for Healthy Weight and Nutrition. The majority of referrals were placed by Primary Care. Dermatology placed 7.1% of the referrals to the Center for Healthy Weight and Nutrition for these patients. CONCLUSIONS: The results suggest that there is a need for increased awareness, education, and counseling on weight management and nutrition for pediatric hidradenitis suppurativa patients. Further studies are needed to determine the success of counseling on weight control and disease severity.

Dermatologic Device Clearance Within the Food and Drug Administration's 510(k) Pathway.

BACKGROUND AND OBJECTIVES: Device innovation in dermatology is increasing. Medical devices identified as "substantially equivalent" to predicate ones by the United States Food and Drug Administration (FDA) may be exempt from premarket approval through the 510(k) pathway. The 510(k) pathway has been criticized for having less stringent clinical data requirements, and implications of dermatologic device clearance via this pathway are incompletely described. The objective of this study is to characterize dermatologic device clearance via the 510(k) pathway. STUDY DESIGN/MATERIALS AND METHODS: We performed a retrospective review of the FDA's 510(k) database between January 1, 1996 and December 31, 2018. Dermatologic devices were included based on product code and classified by the application. Approval pathways and decision characteristics were compared among dermatologic device categories. RESULTS: Of the 76,607 records screened, 4,637 met inclusion criteria. Laser/thermal devices comprised the largest category (64.2%), followed by wound (24.0%) and light-based devices (5.8%). The majority of 510(k) pathway submissions were traditional (89.2%) compared with alternative (10.8%) submission types (P = 0.003). Devices that were deemed substantially equivalent without limitations (98.5%) were the most common among all device categories. Rates of device clearance over the study period increased for all categories except laser/thermal devices. CONCLUSIONS: Dermatologic devices are increasingly cleared via the FDA's 510(k) pathway through "substantial equivalence" with minimal requirements for premarket clinical data. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Pesticide residues determination in common bean using an optimized QuEChERS approach followed by solvent exchange and GC-MS/MS analysis.

BACKGROUND: Common bean is a staple food in Latin America and Africa; however, studies about contamination of common bean with pesticides are rarely reported. So, the goals of this study were to validate a multiresidue method and apply it in monitoring of pesticides in common beans. Extraction was performed applying the QuEChERS (quick, easy, cheap, effective, rugged, and safe) approach to ground samples. Octadecylsilane and primary-secondary amine were used for clean-up, and a solvent exchange step was performed before injection for gas chromatography-tandem mass spectrometry analysis. Method validation was done analyzing blank samples spiked at 20, 30, 50, and 100 µg kg-1 (n = 5). Linearity and linear range were assessed by the analysis of standard solutions at concentrations of 5, 15, 25, 50, 75, 100, and 150 µg L-1 . RESULTS: The method was successfully validated for 91 (64.1%) of the 142 compounds studied (139 pesticides and three degradation products). Limits of quantification were equal to 20 µg kg-1 , 30 µg kg-1 , 50 µg kg-1 , and 100 µg kg-1 for 18 (12.7%), 17 (12.0%), 21 (14.8%) and 35 (24.6%) compounds respectively. Fifteen (10.6%) compounds were not detected at any level, and 36 (25.4%) did not fulfill the requirements for a quantitative method. Sixteen common bean samples of South of Brazil were analyzed. Two samples were positive: one for tebuconzole and a second for picoxystrobin, permethrin, and cyproconazole. Cyproconazole is not allowed for use in the common bean crop, its use being a violation. CONCLUSION: As demonstrated, the validated approach is suitable for pesticide residues determination in common bean. Results of the sample analysis show that the control of pesticide residues in common bean is necessary to ensure food safety. © 2020 Society of Chemical Industry.

Immune checkpoint inhibitor-induced sarcoidosis-like granulomas.

Immune checkpoint inhibitors targeting the cytotoxic T lymphocyte-associated antigen-4 and programmed cell death-1 receptors have transformed the treatment of melanoma and other cancers. These therapies are associated with a number of side effects, including immune-related adverse events. Sarcoidosis-like granulomas (SLGs) are important immune checkpoint inhibitor-related reactions to recognize as SLGs can mimic disease progression and accordingly impact treatment decisions. We systematically review reports of immune checkpoint inhibitor-induced SLGs in cancer patients and discuss potential underlying pathophysiological mechanisms.

Simultaneous determination of pesticides and mycotoxins in wine by direct injection and liquid chromatography-tandem mass spectrometry analysis.

A simple and rapid method for simultaneous determination of pesticides and mycotoxins in red wine is presented. Sample preparation approach, called direct injection, consists of a sequence of only three steps: centrifugation, dilution and filtration. The analysis of extracts were performed by UPLC-MS/MS for determination of pesticides and mycotoxins. The method was assessed for linearity, limits of detection and quantification, matrix effects, selectivity, accuracy and precision. For recovery experiments, mycotoxins were divided in two groups according to their sensitivity in the UPLC-MS/MS system. More than 80% of the mycotoxins were reliably quantified at the lowest spike level studied (1 µg kg-1 for group 1 and 50 µg kg-1 for group 2). From the 185 evaluated pesticides, 144 showed acceptable results at 10 µg kg-1, the lowest spiked level. Matrix effects were, in most of the cases, negative, and that was observed for both pesticides and mycotoxins.

Simultaneous determination of 117 pesticides and 30 mycotoxins in raw coffee, without clean-up, by LC-ESI-MS/MS analysis.

This paper describes the optimization and validation of an acetonitrile based method for simultaneous extraction of multiple pesticides and mycotoxins from raw coffee beans followed by LC-ESI-MS/MS determination. Before extraction, the raw coffee samples were milled and then slurried with water. The slurried samples were spiked with two separate standard solutions, one containing 131 pesticides and a second with 35 mycotoxins, which were divided into 3 groups of different relative concentration levels. Optimization of the QuEChERS approach included performance tests with acetonitrile acidified with acetic acid or formic acid, with or without buffer and with or without clean-up of the extracts before LC-ESI-MS/MS analysis. For the clean-up step, seven d-SPE sorbents and their various mixtures were evaluated. After method optimization a complete validation study was carried out to ensure adequate performance of the extraction and chromatographic methods. The samples were spiked at 3 concentrations levels with both mycotoxins and pesticides (with 6 replicates at each level, n = 6) and then submitted to the extraction procedure. Before LC-ESI-MS/MS analysis, the acetonitrile extracts were diluted 2-fold with methanol, in order to improve the chromatographic performance of the early-eluting polar analytes. Calibration standard solutions were prepared in organic solvent and in blank coffee extract at 7 concentration levels and analyzed 6 times each. The method was assessed for accuracy (recovery %), precision (RSD%), selectivity, linearity (r2), limit of quantification (LOQ) and matrix effects (%).

Validation and application of micro flow liquid chromatography-tandem mass spectrometry for the determination of pesticide residues in fruit jams.

In this study, a very sensitive method was validated to determine pesticides residues in fruit jams using micro flow liquid chromatography-tandem mass spectrometry (µLC-MS/MS). A slurry of the fruit jams and water was prepared to yield homogeneous samples. Because of the high sensitivity achieved with the µLC-MS/MS equipment and to minimize matrix effects, the QuEChERS extracts were diluted 30-fold before the analysis. The validation was performed analyzing spiked samples at 9 and 45 µg kg(-1) (n=5). The method met validation criteria of 70-120% recovery and RSD≤20% for 92% of the 107 pesticides evaluated. The reporting limit (RL) was 9 and 45 µg kg(-1) for respectively 66% and 26% of the analytes, 5% of the compounds did not fulfill the requirements for validation and 3% were not detected at the studied concentrations. The validated method was applied to the analysis of 51 different fruit jam samples from Brazil and Spain and pesticide residues were detected in 41 samples, 26 of which contained at least one pesticide at concentration >10 µg kg(-1).

Resident Rounds: Part III--Case Report: Metastatic Multiple Myeloma.

We report a case of cutaneous plasmacytomas developing in a patient with a 7-month history of progressive multiple myeloma refractory to bortezomib and combination chemotherapy. When involving the skin, plasmacytomas typically arise in the setting of multiple myeloma as contiguous extensions from underlying bony disease. More rarely, cutaneous plasmacytomas develop from hematologic metastases in patients with a high systemic plasma cell tumor burden. In our patient, the presence of cutaneous plasmacytomas involving two distinct sites, and malignant plasma cells within the dermis without infiltration into the subcutaneous fat, suggest a diagnosis of metastatic multiple myeloma to the skin. Metastatic multiple myeloma to the skin portends a poor prognosis, and treatment should be aimed at the underlying systemic disease.

Microflow liquid chromatography coupled to mass spectrometry--an approach to significantly increase sensitivity, decrease matrix effects, and reduce organic solvent usage in pesticide residue analysis.

This manuscript reports a new pesticide residue analysis method employing a microflow-liquid chromatography system coupled to a triple quadrupole mass spectrometer (microflow-LC-ESI-QqQ-MS). This uses an electrospray ionization source with a narrow tip emitter to generate smaller droplets. A validation study was undertaken to establish performance characteristics for this new approach on 90 pesticide residues, including their degradation products, in three commodities (tomato, pepper, and orange). The significant benefits of the microflow-LC-MS/MS-based method were a high sensitivity gain and a notable reduction in matrix effects delivered by a dilution of the sample (up to 30-fold); this is as a result of competition reduction between the matrix compounds and analytes for charge during ionization. Overall robustness and a capability to withstand long analytical runs using the microflow-LC-MS system have been demonstrated (for 100 consecutive injections without any maintenance being required). Quality controls based on the results of internal standards added at the samples' extraction, dilution, and injection steps were also satisfactory. The LOQ values were mostly 5 µg kg(-1) for almost all pesticide residues. Other benefits were a substantial reduction in solvent usage and waste disposal as well as a decrease in the run-time. The method was successfully applied in the routine analysis of 50 fruit and vegetable samples labeled as organically produced.

Autocrine function of aldehyde dehydrogenase 1 as a determinant of diet- and sex-specific differences in visceral adiposity.

Mechanisms for sex- and depot-specific fat formation are unclear. We investigated the role of retinoic acid (RA) production by aldehyde dehydrogenase 1 (Aldh1a1, -a2, and -a3), the major RA-producing enzymes, on sex-specific fat depot formation. Female Aldh1a1(-/-) mice, but not males, were resistant to high-fat (HF) diet-induced visceral adipose formation, whereas subcutaneous fat was reduced similarly in both groups. Sexual dimorphism in visceral fat (VF) was attributable to elevated adipose triglyceride lipase (Atgl) protein expression localized in clusters of multilocular uncoupling protein 1 (Ucp1)-positive cells in female Aldh1a1(-/-) mice compared with males. Estrogen decreased Aldh1a3 expression, limiting conversion of retinaldehyde (Rald) to RA. Rald effectively induced Atgl levels via nongenomic mechanisms, demonstrating indirect regulation by estrogen. Experiments in transgenic mice expressing an RA receptor response element (RARE-lacZ) revealed HF diet-induced RARE activation in VF of females but not males. In humans, stromal cells isolated from VF of obese subjects also expressed higher levels of Aldh1 enzymes compared with lean subjects. Our data suggest that an HF diet mediates VF formation through a sex-specific autocrine Aldh1 switch, in which Rald-mediated lipolysis in Ucp1-positive visceral adipocytes is replaced by RA-mediated lipid accumulation. Our data suggest that Aldh1 is a potential target for sex-specific antiobesity therapy.

A multi-residue method for pesticides analysis in green coffee beans using gas chromatography-negative chemical ionization mass spectrometry in selective ion monitoring mode.

In this study, a new gas chromatography-mass spectrometry (GC-MS) method, using the very selective negative chemical ionization (NCI) mode, was developed and applied in combination with a modified acetonitrile-based extraction method (QuEChERS) for the analysis of a large number of pesticide residues (51 pesticides, including isomers and degradation products) in green coffee beans. A previously developed integrated sample homogenization and extraction method for both pesticides and mycotoxins analysis was used. An homogeneous slurry of green milled coffee beans and water (ratio 1:4, w/w) was prepared and extracted with acetonitrile/acetic acid (1%), followed by magnesium sulfate addition for phase separation. Aliquots from this extract could be used directly for LC-MS/MS analysis of mycotoxins and LC-amenable pesticides. For GC-MS analysis, a further clean-up was necessary. C18- and PSA-bonded silica were tested as dispersive solid-phase extraction (d-SPE) sorbents, separate and as a mixture, and the best results were obtained using C18-bonded silica. For the optimal sensitivity and selectivity, GC-MS detection in the NCI-selected ion monitoring (SIM) mode had to be used to allow the fast analysis of the difficult coffee bean matrix. The validation was performed by analyzing recovery samples at three different spike concentrations, 10, 20 and 50 µg kg(-1), with 6 replicates (n=6) at each concentration. Linearity (r(2)) of calibration curves, estimated instrument and method limits of detection and limits of quantification (LOD(i), LOD(m), LOQ(i) and LOQ(m), respectively), accuracy (as recovery %), precision (as RSD%) and matrix effects (%) were determined for each individual pesticide. From the 51 analytes (42 parent pesticides, 4 isomers and 5 degradation products) determined by GC-MS (NCI-SIM), approximately 76% showed average recoveries between 70-120% and 75% and RSD ≤ 20% at the lowest spike concentration of 10 µg kg(-1), the target method LOQ. For the spike concentrations of 20 and 50 µg kg(-1), the recoveries and RSDs were even better. The validated LOQ(m) was 10, 20 and 50 µg kg(-1) for respectively 33, 3 and 6 of the analytes studied. For five compounds, the European Union method performance requirements for the validation of a quantitative method (average recoveries between 70-120% and repeatability RSD ≤ 20%) were not achieved and 4 problematic pesticides (captan, captafol, folpet and dicofol) could not be detected as their parent compound, but only via their degradation products. Although the matrix effect (matrix-enhanced detector response) was high for all pesticides studied, the matrix interference was minimal, due to the high selectivity obtained with the GC-NCI-MS detection. Matrix-matched calibration for applying the method in routine analysis is recommended for reliable quantitative results.

The contribution of vitamin A to autocrine regulation of fat depots.

Morbidity and mortality associated with increased white fat accumulation in visceral fat depots have focused attention on the pathways regulating the development of this tissue during embryogenesis, in adulthood, and while under the influence of obesogenic diets. Adipocytes undergo clonal expansion, differentiation (adipogenesis) and maturation through a complex network of transcriptional factors, most of which are expressed at similar levels in visceral and subcutaneous fat. Rigorous research attempts to unfold the pathways regulating expression and activity of adipogenic transcription factors that act in a fat-depot-specific manner. Peroxisome proliferator-activated receptor-γ (PPARγ) is the master regulator of adipogenesis, and is expressed at higher levels in subcutaneous than in visceral depots. PPARγ expression in adipogenesis is mediated by CCAAT/enhancer binding proteins (C/EBPs) and several transcription factors acting in conjunction with C/EBPs, although alternative pathways through zinc-finger protein-423 (ZFP423) transcription factor are sufficient to induce PPARγ expression and adipogenesis. Vitamin A and its metabolites, retinaldehyde and retinoic acid, are transcriptionally-active molecules. Retinoic acid is generated from retinaldehyde in adipose tissue by the aldehyde dehydrogenase-1 family of enzymes (Aldh1). In this review, we discuss the role of Aldh1 enzymes in the generation of retinoic acid during adipogenesis, in the regulation of the transcriptional network of PPARγ in a fat-depot-specific manner, and the important contribution of this autocrine pathway in the development of visceral obesity. This article is part of a Special Issue entitled Retinoid and Lipid Metabolism.

Concerted action of aldehyde dehydrogenases influences depot-specific fat formation.

Vitamin A metabolite retinoic acid (RA) regulates life-sustaining differentiation processes and metabolic homeostasis. The aldehyde dehydrogenase-1 (Aldh1) family of enzymes (Aldh1a1, a2, and a3) catalyzes RA production from retinaldehyde and thereby controls concentrations of this transcriptionally active metabolite. The hierarchy of Aldh1 functions in adipose tissue has not been elucidated. We hypothesized that Aldh1 enzymes produce endogenous RA and regulate adipogenesis and fat formation in a fat depot-specific manner. We demonstrate that adipogenesis in vitro is accompanied by RA production generated primarily by Aldh1a1. In Aldh1a1-deficient adipocytes, adipogenesis is impaired compared with wild-type adipocytes due to markedly reduced expression of PPARγ regulated through zinc-finger protein 423 (ZFP423)-dependent mechanisms. These effects were recovered to some extent either by RA stimulation or overexpression of any of the Aldh1 enzymes in Aldh1a1(-/-) cells arguing that Aldh1a1 plays a dominant role in autocrine RA production. In vivo studies in C57/BL6 and Aldh1a1(-/-) mice on a regular diet revealed that multiple Aldh1 enzymes regulate differences in the formation of sc and visceral fat. In Aldh1a1(-/-) mice, visceral fat essentially lacked all Aldh1 expression. This loss of RA-producing enzymes was accompanied by 70% decreased expression of ZFP423, PPARγ, and Fabp4 in visceral fat of Aldh1a1(-/-) vs. wild-type mice and by the predominant loss of visceral fat. Subcutaneous fat of Aldh1a1(-/-) mice expressed Aldh1a3 for RA production that was sufficient to maintain expression of ZFP423 and PPARγ and sc fat mass. Our data suggest a paradigm for regulation of fat depots through the concerted action of Aldh1 enzymes that establish RA-dependent tandem regulation of transcription factors ZFP423 and PPARγ in a depot-specific manner.

Use of isotopes to study floodplain wetland and river flow interaction in the White Volta River basin, Ghana.

Floodplain wetlands influence the timing and magnitude of stream responses to rainfall. In managing and sustaining the level of water resource usage in any river catchment as well as when modelling hydrological processes, it is essential that the role of floodplain wetlands in stream flows is recognised and understood. Existing studies on hydrology within the Volta River basin have not adequately represented the variability of wetland hydrological processes and their contribution to the sustenance of river flow. In order to quantify the extent of floodwater storage within riparian wetlands and their contribution to subsequent river discharges, a series of complementary studies were conducted by utilising stable isotopes, physical monitoring of groundwater levels and numerical modelling. The water samples were collected near Pwalugu on the White Volta River and at three wetland sites adjacent to the river using the grab sampling technique. These were analysed for (18)O and (2)H. The analysis provided an estimate of the contribution of pre-event water to overall stream flow. In addition, the variation in the isotopic composition in the river and wetland water samples, respectively, revealed the pattern of flow and exchange of water between the wetlands and the main river system.