Effect of severe renal impairment on the pharmacokinetics of brigatinib.

Background Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, targets activated, mutant forms of ALK and overcomes mechanisms of resistance to the ALK inhibitors crizotinib, ceritinib, and alectinib. Brigatinib is approved in multiple countries for treatment of patients with ALK-positive non-small cell lung cancer. Based on population pharmacokinetic (PK) analyses, no dosage adjustment is required for patients with mild or moderate renal impairment. Methods An open-label, single-dose study was conducted to evaluate the PK of brigatinib (90 mg) in patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m2; n = 8) and matched healthy volunteers with normal renal function (estimated glomerular filtration rate ≥ 90 mL/min/1.73 m2; n = 8). Plasma and urine were collected for the determination of plasma protein binding and estimation of plasma and urine PK parameters. Results Plasma protein binding of brigatinib was similar between patients with severe renal impairment (92 % bound) and matched healthy volunteers with normal renal function (91 % bound). Unbound brigatinib exposure (area under the plasma concentration-time curve from time zero to infinity) was approximately 92 % higher in patients with severe renal impairment compared with healthy volunteers with normal renal function. The renal clearance of brigatinib in patients with severe renal impairment was approximately 20 % of that observed in volunteers with normal renal function. Conclusions These findings support a brigatinib dosage reduction of approximately 50 % in patients with severe renal impairment.Trial registry: Not applicable.

68Ga-Labeled bismacrocyclic methylene phosphonate as potential bone seeking PET radiopharmaceutical.

Phosphonates-based agents are well-known bone-seeking radiopharmaceuticals with application in detection and therapy. With higher sensitivity and resolution offered by Positron Emission Tomography (PET), tracers based on this technique are gaining huge attention. 68Ga-based generator and radiotracers render independence from the on-site cyclotron. We report the development of 68Ga-labeled DOTA-based bismacrocyclic phosphonate derivative, for bone PET imaging. The synthesis and characterization of 68Ga- DO3P-AME-DO3P was carried out in > 95% purity. The radiotracer displayed high stability and low binding affinity (<3%) to blood serum. High in vitro binding affinity were observed for synthetic hydroxyapatite, SAOS-2, osteoclast and osteoblast cells. In vivo pharmacokinetics revealed fast washout with biphasic release pattern. The deposition of radiotracer in osseous tissues was high (Bone/Muscle ratio:18), as studied from the biodistribution studies. In vivo PET/CT and biodistribution analyses revealed the ability of 68Ga-DO3P-AME-DO3P to target and accumulate in bone, thus displaying its potential as a PET bone imaging agent.

Brigatinib Versus Crizotinib in Advanced ALK Inhibitor-Naive ALK-Positive Non-Small Cell Lung Cancer: Second Interim Analysis of the Phase III ALTA-1L Trial.

PURPOSE: Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, demonstrated superior progression-free survival (PFS) and improved health-related quality of life (QoL) versus crizotinib in advanced ALK inhibitor-naive ALK-positive non-small cell lung cancer (NSCLC) at first interim analysis (99 events; median brigatinib follow-up, 11.0 months) in the open-label, phase III ALTA-1L trial (ClinicalTrials.gov identifier: NCT02737501). We report results of the second prespecified interim analysis (150 events). METHODS: Patients with ALK inhibitor-naive advanced ALK-positive NSCLC were randomly assigned 1:1 to brigatinib 180 mg once daily (7-day lead-in at 90 mg once daily) or crizotinib 250 mg twice daily. The primary end point was PFS as assessed by blinded independent review committee (BIRC). Investigator-assessed efficacy, blood samples for pharmacokinetic assessments, and patient-reported outcomes were also collected. RESULTS: Two hundred seventy-five patients were randomly assigned (brigatinib, n = 137; crizotinib, n = 138). With median follow-up of 24.9 months for brigatinib (150 PFS events), brigatinib showed consistent superiority in BIRC-assessed PFS versus crizotinib (hazard ratio [HR], 0.49 [95% CI, 0.35 to 0.68]; log-rank P < .0001; median, 24.0 v 11.0 months). Investigator-assessed PFS HR was 0.43 (95% CI, 0.31 to 0.61; median, 29.4 v 9.2 months). No new safety concerns emerged. Brigatinib delayed median time to worsening of global health status/QoL scores compared with crizotinib (HR, 0.70 [95% CI, 0.49 to 1.00]; log-rank P = .049). Brigatinib daily area under the plasma concentration-time curve was not a predictor of PFS (HR, 1.005 [95% CI, 0.98 to 1.031]; P = .69). CONCLUSION: Brigatinib represents a once-daily ALK inhibitor with superior efficacy, tolerability, and QoL over crizotinib, making it a promising first-line treatment of ALK-positive NSCLC.

Salt-assisted acetonitrile extraction and HPLC-QTOF-MS/MS detection for residues of multiple classes of pesticides in human serum samples.

Detecting pesticide residues in human serum is a challenging process. In this study we developed and validated a method for the extraction and recovery of residues of multiple classes of pesticides from serum using one reagent. Salt-assisted acetonitrile extraction and high-performance liquid chromatography with quadrupole time of flight tandem mass spectrometry were used to quantitate 34 pesticides classified in nine groups of chemicals in human serum samples, which are frequently detected in food. The recoveries for 33 of analyzed pesticides ranged from 86 to 112% with relative standard deviations below 15%. The limits of quantitation and linearity of 31 of the pesticides were 1 µg/L and >0.990, respectively. The lower limit of quantitation has been reported in the literature particularly for multi-classes pesticide mixtures in human serum. The salt-acetonitrile reagent was allowed to achieve good recoveries and detection limits, which could be attributed to salt altering the solvent polarity, preferentially collecting the organic phase in the solution, and promoting the extraction. The developed method was applied for two organophosphate pesticide metabolites, diethylphosphate and 3,5,6-trichloro-2-pyridinol, in serum from rats that were fed a nonlethal quantity of chlorpyrifos. The concentrations of these two were 252.18 ± 15.47 and 0.63 ± 0.23 µg/L, respectively.

Organochlorine and organophosphorus pesticides and bladder cancer: A case-control study.

BACKGROUND: Exposure to pesticides is associated with an increase in the incidence of cancer. We aimed to investigate the association of serum organochlorine pesticides (OCPs) and organophosphorus pesticides (OPs) levels and GSTM1/GSTT1 gene polymorphism with bladder cancer (BC). METHODS: This study was performed on 57 patients with BC and 30 controls (C). Acetylcholinesterase (AChE) activity, arylesterase activity of paraoxonase-1 (ARE), total antioxidant capacity (TAC), and malondialdehyde (MDA) levels were determined in serums of all participants. Genomic DNA was extracted using the salting out method and GSTM1/GSTT1 gene polymorphisms were examined by multiplex polymerase chain reaction assay. Measurement of OCPs (α-hexachlorocyclohexane [α-HCH], ß-HCH, γ-HCH, 2,4-dichlorodiphenyltrichloroethane [2,4-DDT], 4,4-DDT, 2,4- dichlorodiphenyldichloroethylene [2,4-DDE], and 4,4-DDE) in serum was carried out using an FID-equipped gas-chromatography system. RESULTS: AChE activity was significantly lower, ARE activity and TAC were declined but it was not statistically significant, however, α-HCH, γ-HCH, 4,4-DDE, 2,4-DDT, and 4,4-DDT pesticides, and MDA were significantly higher in BC patients compared with the control subjects. Also, a positive correlation was found between the number of smoked cigarettes and the years of smoking with BC development. There was no association between GSTM1/GSTT1 gene polymorphisms and OCPs in BC patients. CONCLUSION: Due to the higher levels of some OCPs in the BC patients, along with the reduction in AChE activity and increased MDA levels, it may be concluded that OCPs and OPs play an important role in the induction of BC in southeastern Iran.

Organochlorine and organophosphorous pesticides may induce colorectal cancer; A case-control study.

OBJECTIVES: Among the numerous agents, genetic factors and environmental elements such as pesticides have an important role in colorectal cancer (CRC) incidence. The present study aimed to investigate the probable-role of some organochlorine pesticides (OCPs) and organophosphorous pesticides (OPPs) in patients with CRC. METHODS: In this case-control study, 42 patients with CRC and 30 healthy subjects were selected. The serum levels of some OCPs (α-HCH, ß-HCH, γ-HCH, 2,4 DDE, 4,4 DDE, 2,4DDT and 4,4DDT) were measured by gas chromatography (GC) method. Serum levels of malondialdehyde (MDA), and total antioxidant capacity (TAC) as well as the enzyme activity of acetylcholinesterase (AChE) and arylesterase activity of Paraoxonase-1 (PON-1) were evaluated in all participants. The methylation specific PCR (MSP) assay was used for determining the methylation status of CpG island of p16 and MGMT genes in CRC patients. RESULTS: The mean serum levels of each OCPs were significantly higher in the patient group compared to the control group (P < 0.001). The AChE and arylesterase activity of PON-1 in the patient group were significantly lower than the control group (P < 0.001). The mean serum levels of MDA and TAC in the serum of the patient group were significantly higher than the control group (P < 0.001 and P < 0.002, respectively). The current findings demonstrated significantly hypermethylation of p16 promoter in CRC patients. CONCLUSION: Regarding the higher levels of OCPs in CRC patients, along with hypermethylation of the p16 promoter gene, diminishing in AChE and PON-1 activity and increasing in oxidative stress factors, the role of OCPs and OPPs in the CRC progression in the South-East of Iran may be assumed.

The ocular pharmacokinetics and biodistribution of phospho-sulindac (OXT-328) formulated in nanoparticles: Enhanced and targeted tissue drug delivery.

We studied the pharmacokinetics, biodistribution and metabolism of phospho-sulindac (PS), a novel agent efficacious in the treatment of dry eye, formulated in nanoparticles (PS-NPs) following its topical administration to the eye of New Zealand White rabbits. The nanoparticles were spherical with effective diameter = 108.9 ±â€¯41.7 nm, zeta potential = -21.70 ±â€¯3.78 mV, drug loading = 7%, and entrapment efficiency = 46.4%. Of the total PS delivered topically to the eye, >95% was retained in the anterior segment, predominantly in the cornea (Cmax = 101.3 µM; Tmax = 1 h; T1/2 = 2.6 h; area AUC0-16h = 164.4 µM·h) and conjunctiva (Cmax = 89.4 µM; Tmax = 0.25 h; T1/2 = 3.1 h; AUC0-16h = 63.5 µM·h), the tissues most affected by dry eye disease. No PS or its metabolites were detected in the systemic circulation. PS was metabolized to PS sulfide and PS sulfone; all three molecules were hydrolyzed to sulindac, which was converted to sulindac sulfide and sulindac sulfone. A solution formulation of PS provided lower PS levels in ocular tissues but higher levels of PS metabolites, compared to PS-NPs. Therefore, NPs represent an effective formulation for the topical ocular administration of PS for anterior segment diseases, such as dry eye disease.

P-glycoprotein and breast cancer resistance protein restrict brigatinib brain accumulation and toxicity, and, alongside CYP3A, limit its oral availability.

Brigatinib is an FDA-approved oral anaplastic lymphoma kinase (ALK) inhibitor for treatment of metastatic non-small cell lung cancer (NSCLC). Using genetically modified mouse models, we investigated the roles of the multidrug efflux transporters ABCB1 and ABCG2, and the multispecific drug-metabolizing enzyme CYP3 A in plasma pharmacokinetics and tissue distribution of brigatinib. In vitro, brigatinib was exceptionally well transported by human ABCB1 and mouse Abcg2, and efficiently by human ABCG2. Following oral brigatinib administration (10 mg/kg), brain accumulation was dramatically increased in Abcb1a/1b-/- (19.3-fold) and Abcb1a/1b;Abcg2-/-(41.8-fold), but not in single Abcg2-/- mice compared to wild-type mice. Brigatinib testis accumulation showed qualitatively similar behavior. mAbcb1a/1b and mAbcg2 together restricted systemic exposure of brigatinib: with both systems absent oral availability increased 1.9-fold. Coadministration of elacridar, an ABCB1/ABCG2 inhibitor, caused a pronounced increase (36-fold) in brain-to-plasma ratios of brigatinib, approaching the levels seen in Abcb1a/1b;Abcg2-/- mice. Unexpectedly, lethal toxicity of oral brigatinib was observed in mice with genetic knockout or pharmacological inhibition of mAbcb1a/1b and mAbcg2, indicating a pronounced protective role for these transporters. In Cyp3a-/- mice, brigatinib plasma exposure increased 1.3-fold, and was subsequently 1.8-fold reduced by transgenic overexpression of human CYP3 A4 in liver and intestine. The relative tissue distribution of brigatinib, however, remained unaltered. ABCB1 and ABCG2 thus limit brain accumulation, toxicity, and systemic exposure of brigatinib, whereas CYP3 A also markedly restricts its oral availability. Unexpected toxicities should therefore be carefully monitored when brigatinib is coadministered with ABCB1/ABCG2 inhibitors in patients. Collectively, these insights may support the clinical application of brigatinib.

Investigation of dried blood sampling with liquid chromatography tandem mass spectrometry to confirm human exposure to nerve agents.

A method was developed to detect and quantify organophosphate nerve agent (OPNA) metabolites in dried blood samples. Dried blood spots (DBS) and microsampling devices are alternatives to traditional blood draws, allowing for safe handling, extended stability, reduced shipping costs, and potential self-sampling. DBS and microsamplers were evaluated for precision, accuracy, sensitivity, matrix effects, and extraction recovery following collection of whole blood containing five OPNA metabolites. The metabolites of VX, Sarin (GB), Soman (GD), Cyclosarin (GF), and Russian VX (VR) were quantitated from 5.0 to 500 ng mL-1 with precision of ≤16% and accuracy between 93 and 108% for QC samples with controlled volumes. For unknown spot volumes, OPNA metabolite concentrations were normalized to total blood protein to improve interpretation of nerve agent exposures. This study provides data to support the use of DBS and microsamplers to collect critical exposure samples quickly, safely, and efficiently following large-scale chemical exposure events.

Bioanalytical liquid chromatography-tandem mass spectrometric assay for the quantification of the ALK inhibitors alectinib, brigatinib and lorlatinib in plasma and mouse tissue homogenates.

Several second and third generation ALK inhibitors have been introduced in recent years. A bioanalytical assay for simultaneous quantification of alectinib, brigatinib, and lorlatinib was developed and validated for human plasma. The method was also partially validated for diluted mouse plasma and tissue homogenates of brain, liver, kidney, and spleen. Samples (40 µl) were pretreated in a 96-well plate by protein precipitation with acetonitrile containing the internal standard [2H8]-alectinib. After chromatographic separation on an ethylene bridged octadecyl silica column by gradient elution at 600 µl/min using 1% (v/v) formic acid (in water) and acetonitrile, compounds were ionized by a turbo electrospray and monitored by selected reaction monitoring on a triple quadrupole mass spectrometer. Validation was performed in a 2-2000 ng/ml concentration range for alectinib and lorlatinib and a 4-4000 ng/ml range for brigatinib. Precisions (within-day and between-day) were in the range 2.2-15.0% and accuracies were in between 87.2 and 110.2% for all matrices and levels. Compounds were sufficiently stable under most investigated conditions. Results of a pilot pharmacokinetic and tissue distribution study for brigatinib in mice are reported. Finally, successful incurred samples reanalysis of tissue homogenate samples containing brigatinib and lorlatinib is presented. Lorlatinib homogenate samples were also successfully reanalyzed using a second independent assay (cross-validation).

Biomarkers of oxidative stress in blood of workers exposed to non-cholinesterase inhibiting pesticides.

In occupational settings workers are often exposed to pesticides at relatively high doses compared to environmental exposures. Long-term exposure to pesticides has been associated with numerous adverse health effects in epidemiological studies, and oxidative stress is often claimed as one of the underlying mechanisms. In fact, different pesticides have been reported to induce oxidative stress due to the generation of free radicals and/or alteration in antioxidant defense enzymes. The present study examined greenhouse workers regularly exposed to diverse pesticides under integrated production system, and a group of controls of the same geographic area without any chemical exposure. Two different periods of the same crop season were assessed, one of high exposure (with greater use of pesticides) and other of low exposure (in which a less use of these compounds was made). Non-specific biomarkers of oxidative stress, e.g. thiobarbituric acid reactive substances (TBARS), ferric reducing ability of serum (FRAS), total thiol groups (SHT), gamma-glutamyl transpeptidase (GGT) and paraoxonase-1 (PON1) were measured in serum samples from all study subjects, alongside erythrocyte acetylcholinesterase (AChE). Results are suggestive of a mild increase in oxidative stress associated with pesticide exposure, which was compensated by an adaptive response to raise the antioxidant defenses and thus counter the detrimental effects of sustained oxidative stress. This response led to significantly increased levels of FRAS, SHT and PON1 in greenhouse workers relative to controls. Furthermore, AChE was decreased likely as a result of oxidative stress as workers did not use organophosphate insecticides.

A toolbox for microbore liquid chromatography tandem-high-resolution mass spectrometry analysis of albumin-adducts as novel biomarkers of organophosphorus pesticide poisoning.

Exposure to toxic organophosphorus pesticides (OPP) represents a serious problem in the public healthcare sector and might be forced in terroristic attacks. Therefore, reliable verification procedures for OPP-intoxications are required for forensic, toxicological and clinical reasons. We developed and optimized a toolbox of methods to detect adducts of human serum albumin (HSA) with OPP considered as long-term biomarkers. Human serum was incubated with diethyl-oxono and diethyl-thiono pesticides for adduct formation used as reference. Afterwards serum was subjected to proteolysis using three proteases separately thus yielding phosphorylated tyrosine residues (Y*) detected as single amino acid (pronase), as hexadecapeptide LVRY*411TKKVPQVSTPTL (pepsin) and as the tripeptide Y*411TK (trypsin), respectively. Adducts were analyzed via microbore liquid chromatography coupled to electrospray ionization (µLC-ESI) and tandem-high-resolution mass spectrometry (MS/HR MS). Using paraoxon-ethyl as model OPP for adduct formation, methods were optimized with respect to MS/HR MS-parameters, protease concentrations and incubation time for proteolysis. HSA-adducts were found to be stable in serum in vitro at +37 °C and -30 °C for at least 27 days and resulting biomarkers were stable in the autosampler at 15 °C for at least 24 h. Limits of identification of adducts varied between 0.25 µM and 4.0 µM with respect to the corresponding pesticide concentrations in serum. Applicability of the methods was proven by successful detection of the adducts in samples of OPP-poisoned patients thus demonstrating the methods as a reliable toolbox for forensic and toxicological analysis.

miR-17-92 ameliorates renal ischemia reperfusion injury.

There is limited information on the role of miR-17-92 in renal tubular pathophysiology. Therefore, the present study was performed to determine whether miR-17-92 plays a role in ischemia-reperfusion injury (IRI)-induced acute kidney injury. We originally demonstrated that miR-17-92 is up-regulated following IRI in vivo. To explore the roles of miR-17-92 in the IRI process, we first generated a renal proximal tubule-specific miR-17-92 deletion (PT-miR-17-92-/-) knockout mouse model with Cre driven by the Kap promoter. We found that PT-deficient miR-17-92 mice had more severe renal dysfunction and renal structures than their littermates. Compared with sham-operated mice, both wide-type (WT) mice and PT-miR-17-92-/- mice showed increased serum levels of creatinine and urea. However, the levels of serum urea and creatinine in PT-miR-17-92-/- mice after the IRI operation were significantly higher than the levels in WT mice. In addition, PT-miR-17-92-/- mice showed higher levels of serum potassium and phosphonium after the IRI operation. Histological analysis revealed that PT-miR-17-92-/- mice had substantial histopathologic changes, such as tubular dilation and tubular necrosis. Overexpression of miR-17-92 could partially reverse the side-effects of IRI on the proximal tubules in vivo. Furthermore, we employed a quantitative proteomic strategy and identified 16 proteins as potential targets of miR-17-92. Taken together, our findings suggested that miR-17-92 may ameliorates IRI-induced acute kidney injury. Our results indicate that pharmacologic modulation of these miRNAs may have therapeutic potential for acute kidney injury.

Prenatal organophosphate insecticide exposure and infant sensory function.

BACKGROUND: Occupational studies suggest that exposure to organophosphate insecticides (OPs) can lead to vision or hearing loss. Yet the effects of early-life exposure on visual and auditory function are unknown. Here we examined associations between prenatal OP exposure and grating visual acuity (VA) and auditory brainstem response (ABR) during infancy. METHODS: 30 OPs were measured in umbilical cord blood using gas chromatography tandem mass spectrometry in a cohort of Chinese infants. Grating visual acuity (VA) (n = 179-200) and auditory brainstem response (ABR) (n = 139-183) were assessed at 6 weeks, 9 months, and 18 months. Outcomes included VA score, ABR wave V latency and central conduction time, and head circumference (HC). Associations between sensory outcomes during infancy and cord OPs were examined using linear mixed models. RESULTS: Prenatal chlorpyrifos exposure was associated with lower 9-month grating VA scores; scores were 0.64 (95% CI: -1.22, -0.06) points lower for exposed versus unexposed infants (p = 0.03). The OPs examined were not associated with infant ABR latencies, but chlorpyrifos and phorate were both significantly inversely associated with HC at 9 months; HCs were 0.41 (95% CI: 0.75, 0.6) cm and 0.44 (95% CI: 0.88, 0.1) cm smaller for chlorpyrifos (p = 0.02) and phorate (p = 0.04), respectively. CONCLUSIONS: We found deficits in grating VA and HC in 9-month-old infants with prenatal exposure to chlorpyrifos. The clinical significance of these small but statistically significant deficits is unclear. However, the disruption of visual or auditory pathway maturation in infancy could potentially negatively affect downstream cognitive development.

Investigation of metabolic stability of the novel ALK inhibitor brigatinib by liquid chromatography tandem mass spectrometry.

Brigatinib (BGB) belongs to a class of drugs called ALK inhibitor. On April 28, 2017, BGB has been approved by U.S. FDA for use in metastatic ALK-positive NSCLC. A fast, specific, sensitive and validated LC-MS/MS method was developed for the quantification of BGB in human plasma matrix. This method was applied successfully to study metabolic stability of BGB. Reversed phase (C18 column) and isocratic binary mobile phase (55% 0.1% formic acid: 45% ACN) were used for chromatographic separation of BGB and ponatinib (IS). The flow rate, total run time and injection volume were fixed at 0.2 mL/min, 4 min, 5 µL respectively. ESI source was utilized for ions formation, while multiple reaction monitoring (MRM) mode was used for ion analysis. In human plasma matrix, the Linearity range of the calibration curve was 5-500 ng/mL (r2 ≥ 0.9982). LOQ and LOD were found to be 1.89 and 5.72 ng/mL. The precision and accuracy for the intra-day and inter-day were 0.45 to 1.85% and 97.37 to 104.85%. In vitro half-life (t1/2) and intrinsic clearance (CLint) were equal to 12.0 min and 13.1 ±â€¯0.15 mL/min/kg respectively. The quantification of BGB in human plasma or its metabolic stability has not been studied as seen in literature review.

Simultaneous detection of dual biomarkers from humans exposed to organophosphorus pesticides by combination of immunochromatographic test strip and ellman assay.

A novel sandwich immunoassay based immunochromatographic test strip (ICTS) has been developed for simultaneously measuring both butyrylcholinesterase (BChE) activity and the total amount of BChE (including inhibited and active enzyme) from 70 µLpost-exposure human plasma sample. The principle of this method is based on the BChE monoclonal antibody (MAb) capable of acting as both capture antibody and detection antibody. The BChE MAb which was immobilized on the test line was able to recognize both organophosphorus BChE adducts (OP-BChE) and BChE and provided equal binding affinity, permitting detection of the total enzyme amount in post-exposure human plasma samples. The formed immunocomplexes on the test line can further be excised from the test-strip for subsequent off-line measurement of BChE activity using the Ellman assay. Therefore, dual biomarkers of BChE activity and phosphorylation (OP-BChE) will be obtained simultaneously. The whole sandwich-immunoassay was performed on one ICTS, greatly reducing analytical time. The ICTS sensor showed excellent linear responses for assaying total amount of BChE and active BChE ranging from 0.22 to 3.58nM and 0.22-7.17nM, respectively. Both the signal detection limits are 0.10nM. We validated the practical application of the proposed method to measure 124 human plasma samples from orchard workers and cotton farmers with long-term exposure to organophosphorus pesticides (OPs). The results were in highly agreement with LC/MS/MS which verified our method is extremely accurate. Combining the portability and rapidity of test strip and the compatibility of BChE MAb as both capture antibody and detection antibody, the developed method provides a baseline-free, low-cost and rapid tool for in-field monitoring of OP exposures.

Determination of Organophosphorous Pesticides in Blood Using Microextraction in Packed Sorbent and Gas Chromatography-Tandem Mass Spectrometry.

The aim of our work was to develop a method for the determination of six organophosphorous pesticides (Ops) (azynphos-ethyl (AZP), diazinon (DZN), chlorpyrifos (CLP), chlorfenvinfos (CLF), parathion-ethyl (PRT) and quinalphos (QLP)) in whole blood using microextraction by packed sorbent (MEPS) and analysis by gas chromatography-tandem mass spectrometry (GC-MS/MS). The optimization of the MEPS procedure was performed using a design of experiments (DOE) approach, assessing different factors that significantly affected the extraction efficiency. Ultimately, the number of sample strokes, wash volume, percentage of 2-propanol in the wash solvent and the number of elution strokes were successfully optimized using a response surface methodology (RSM). The developed and optimized method was fully validated according to international guidelines. Linearity was established from 2.5 to 50 µg/mL for AZP and from 0.5 to 50 µg/mL for the remaining compounds, with coefficients of determination (R2) higher than 0.99 in all cases. The lower limit of quantification were 2.5 µg/mL (AZP) and 0.5 µg/mL (remaining compounds). Recoveries ranged from 61% to 77%. Intra- and inter-day precision and accuracy were considered adequate according to the guidelines. This is the first method employing MEPS as a sample preparation procedure for the analysis of these OPs in whole blood.

Organophosphate Flame-Retardants Alter Adult Mouse Homeostasis and Gene Expression in a Sex-Dependent Manner Potentially Through Interactions With ERα.

Flame retardants (FRs) such as polybrominated diphenyl ethers and organophosphate FR (OPFR) persist in the environment and interact with multiple nuclear receptors involved in homeostasis, including estrogen receptors (ERs). However, little is known about the effects of FR, especially OPFR, on mammalian neuroendocrine functions. Therefore, we investigated if exposure to FR alters hypothalamic gene expression and whole-animal physiology in adult wild-type (WT) and ERα KO mice. Intact WT and KO males and ovariectomized WT and KO females were orally dosed daily with vehicle (oil), 17α-ethynylestradiol (2.5 µg/kg), 2,2', 4,4-tetrabromodiphenyl ether (BDE-47, 1 or 10 mg/kg), or an OPFR mixture {1 or 10 mg/kg of tris(1, 3-dichloro-2-propyl)phosphate, triphenyl phosphate, and tricresyl phosphate each} for 28 days. Body weight, food intake, body composition, glucose and insulin tolerance, plasma hormone levels, and hypothalamic and liver gene expression were measured. Expression of neuropeptides, receptors, and cation channels was differentially altered between WT males and females. OPFR suppressed body weight and energy intake in males. FR increased fasting glucose levels in males, and BDE-47 augmented glucose clearance in females. Liver gene expression indicated FXR activation by BDE-47 and PXR and CAR activation by OPFR. In males, OPFR increased ghrelin but decreased leptin and insulin independent of body weight. The loss of ERα reduced the effects of both FR on hypothalamic and liver gene expression and plasma hormone levels. The physiological implications are that males are more sensitive than ovariectomized females to OPFR exposure and that these effects are mediated, in part, by ERα.

A reliable and stable method for determination of brigatinib in rat plasma by UPLC-MS/MS: Application to a pharmacokinetic study.

Brigatinib is the second-generation anaplastic lymphoma kinase - inhibitor in non-small cell lung cancer and it can overcome the crizotinib-resistance. Chromatographic separation was carried out on an Acquity Ultra Performance Liquid Chromatography (UPLC) unit with a BEH C18 column (2.1mm×50mm, 1.7µm). The mobile phase was composed of acetonitrile and 0.1% formic acid in water. No endogenous interfering compounds was discovered at retention time of brigatinib (0.56min) and imatinib (IS, 1.41min). MS/MS detection was performed in positive mode. And the MRM transitions were m/z 584.09→484.08 and m/z 494.3→394.2 for brigatinib and IS, respectively. This method was assessed to be stable, specificity, and no matrix effect in three concentrations (0.004, 0.4, 4µg/mL). The intra-day and inter-day precisions were less than 11.09% and 6.43%. And intra-day and inter-day accuracies were ranged from -3.88% to 5.44%. The recovery of brigatinib was from 85.26% to 96.05%. Additionally, the method had a good linearity in the range of 0.002-5µg/mL. The presented method was effectively implemented to determine the concentration of brigatinib in rat plasma.