Development of an LC-MS/MS method for the determination of five psychoactive drugs in postmortem urine by optimization of enzymatic hydrolysis of glucuronide conjugates.

Purpose: Toxicological analyses of biological samples play important roles in forensic and clinical investigations. Ingested drugs are excreted in urine as conjugates with endogenous substances such as glucuronic acid; hydrolyzing these conjugates improves the determination of target drugs by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, we sought to improve the enzymatic hydrolysis of glucuronide conjugates of five psychoactive drugs (11-nor-9-carboxy-Δ-tetrahydrocannabinol, oxazepam, lorazepam, temazepam, and amitriptyline).

A new method for simultaneous quantification of fosphenytoin, phenytoin and its primary metabolite 5-(4-hydroxyphenyl)-5-phenylhydantoin in whole blood by ultra-performance liquid chromatography-tandem mass spectrometry.

A method for simultaneous quantification of fosphenytoin (F-PHT), phenytoin (PHT) and its main metabolite 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH) in whole blood was developed and validated using ultra-performance liquid chromatography-tandem mass spectrometry. Whole blood samples were pretreated by liquid-liquid extraction with acetonitrile and methanol. Chromatographic separation was performed using a CORTECS™ UPLC® C18 (2.

Evidence of exposure to chemicals and heavy metals during pregnancy in Japanese women.

Purpose: Prenatal exposure to environmental chemicals is a growing concern, because such exposures have been shown to be associated with various diseases. The levels of chemicals and heavy metals in maternal blood, cord blood, maternal urine and amniotic fluid in Japanese pregnant women were investigated.

Methods: A total of 145 women, including 14 fetal growth restriction cases, were included in the present study.

Simultaneous quantification of batrachotoxin and epibatidine in plasma by ultra-performance liquid chromatography/tandem mass spectrometry.

An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous quantification of batrachotoxin and epibatidine in plasma. Plasma samples were pretreated by liquid-liquid extraction with acetonitrile and methanol. The toxins were separated on a reversed phase C18-column (2.

Putative Epimutagens in Maternal Peripheral and Cord Blood Samples Identified Using Human Induced Pluripotent Stem Cells.

The regulation of transcription and genome stability by epigenetic systems are crucial for the proper development of mammalian embryos. Chemicals that disturb epigenetic systems are termed epimutagens. We previously performed chemical screening that focused on heterochromatin formation and DNA methylation status in mouse embryonic stem cells and identified five epimutagens: diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se), and octachlorodipropyl ether (S-421).

Changes in hypothalamic neurotransmitter and prostanoid levels in response to NMDA, CRF, and GLP-1 stimulation.

Determination of neuroactive substances, such as neurotransmitters and prostanoids, in the extracellular space of the living brain is a very important technique in neuroscience. The hypothalamic paraventricular nucleus (PVN) is one of the most important autonomic control centers in the brain. Recently, we demonstrated that thromboxane (Tx) A2 in the PVN may play an important role in adrenomedullary outflow evoked by N-methyl-D-aspartate (NMDA), corticotrophin-releasing factor (CRF), and glucagon-like peptide-1 (GLP-1) stimulation using microdialysis sampling and liquid chromatography-ion trap tandem mass spectrometry (LC-ITMS(n)).

Microbial degradation of linear peptides by strain B-9 of Sphingosinicella and its application in peptide quantification using liquid chromatography-mass spectrometry.

The bacterial strain Sphingosinicella sp. B-9 was originally discovered to have the ability to degrade cyanobacterial cyclic peptides (microcystins), and has three hydrolytic enzymes (MlrA, MlrB, and MlrC). The purpose of this study was to examine in detail the degradation of glucagon/vasoactive intestinal polypeptide (VIP) family peptides by B-9, and to investigate the substrate specificity of B-9 proteases and the possibility of using a B-9 protease as a novel protease for peptide quantification by using a surrogate peptide and mass spectrometry (MS).

Centrally administered isoproterenol induces sympathetic outflow via brain prostaglandin E2-mediated mechanisms in rats.

Brain β-adrenoceptor stimulation can induce elevations of plasma levels of noradrenaline. However, there have been no detailed studies related to signaling pathways downstream of β-adrenoceptors responsible for central sympathetic outflow. In the present study, we pharmacologically examined the possibility that centrally administered isoproterenol can induce elevations of plasma noradrenaline levels in a brain prostaglandin-dependent manner.

Enhanced expression of WD repeat-containing protein 35 via CaMKK/AMPK activation in bupivacaine-treated Neuro2a cells.

We previously reported that bupivacaine induces reactive oxygen species (ROS) generation, p38 mitogen-activated protein kinase (MAPK) activation and nuclear factor-kappa B activation, resulting in an increase in expression of WD repeat-containing protein 35 (WDR35) in mouse neuroblastoma Neuro2a cells. However, the identity of signaling upstream of p38 MAPK pathways to WDR35 expression remains unclear. It has been shown that AMP-activated protein kinase (AMPK) can activate p38 MAPK through diverse mechanisms.

Enhanced expression of WD repeat-containing protein 35 via nuclear factor-kappa B activation in bupivacaine-treated Neuro2a cells.

The family of WD repeat proteins comprises a large number of proteins and is involved in a wide variety of cellular processes such as signal transduction, cell growth, proliferation, and apoptosis. Bupivacaine is a sodium channel blocker administered for local infiltration, nerve block, epidural, and intrathecal anesthesia. Recently, we reported that bupivacaine induces reactive oxygen species (ROS) generation and p38 mitogen-activated protein kinase (MAPK) activation, resulting in an increase in the expression of WD repeat-containing protein 35 (WDR35) in mouse neuroblastoma Neuro2a cells.

Mass spectrometric determination of prostanoids in rat hypothalamic paraventricular nucleus microdialysates.

The hypothalamic paraventricular nucleus (PVN) is one of the most important autonomic control centers in the brain. Several kinds of prostanoids, such as prostaglandin (PG) E2, are considered to act in the PVN as mediators of autonomic responses. In the present study, we used liquid chromatography ion trap tandem mass spectrometry (LC-ITMS(n)) to simultaneously quantify four prostanoids, thromboxane (Tx) B2, PGE2, PGD2 and 15-deoxy-∆(12,14) (15d)-PGJ2 in PVN microdialysates from urethane-anesthetized rats.

Enhanced expression of WD repeat-containing protein 35 (WDR35) stimulated by domoic acid in rat hippocampus: involvement of reactive oxygen species generation and p38 mitogen-activated protein kinase activation.

Background: Domoic acid (DA) is an excitatory amino acid analogue of kainic acid (KA) that acts via activation of glutamate receptors to elicit a rapid and potent excitotoxic response, resulting in neuronal cell death. Recently, DA was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in vitro. We have reported that WDR35, a WD-repeat protein, may mediate apoptosis in several animal models.

Bupivacaine-induced apoptosis independently of WDR35 expression in mouse neuroblastoma Neuro2a cells.

Background: Bupivacaine-induced neurotoxicity has been shown to occur through apoptosis. Recently, bupivacaine was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in a human neuroblastoma cell line. We have reported that WDR35, a WD40-repeat protein, may mediate apoptosis through caspase-3 activation.

Microbial degradation of physiologically active peptides by strain B-9.

The reaction of some physiologically active peptides with bacterial strain B-9 has been investigated. Bradykinin, β-endorphin, and [Leu(5)]enkephalin were quickly degraded, with half-lives of <5 min. Somatostatin, substance P, and angiotensin I were degraded relatively smoothly, with half-lives of 10 min to 1 h, whereas oxytocin and insulin were slowly degraded, with half-lives of 1 and 4 days, respectively.

Di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in media for in vitro fertilization.

In vitro fertilization (IVF) is one of the most important treatments of infertility to provide a chance of conceiving. In IVF treatment, sperm are washed and motile sperm are isolated with sperm washing media (SWM) for the purpose of fertilization; fertilized ova are then incubated for a maximum of 5 or 6d in media for IVF (IVFM). The exposure of fertilized ova to chemicals via such media has not been studied.

Panipenem does not alter the pharmacokinetics of the active metabolite of irinotecan SN-38 and inactive metabolite SN-38 glucuronide (SN-38G) in rats.

The present study has investigated the effect of panipenem, a widely used antibiotic, on the pharmacokinetics of an active metabolite of irinotecan (CPT-11), 7-ethyl-10-hydroxy-camptothecin (SN-38) and SN-38 glucuronide (SN-38G) produced by uridine-diphosphate glucuronosyltransferase (UGT) 1A isoform-mediated glucuronidation in rats. Rats received a 1 h infusion with panipenem at a loading dose of 10 mg/kg and a maintenance dose of 15 mg/min/kg once a day for 5 days. When the effect of pretreatment with panipenem on glucuronidation activities of substrates for hepatic UGT1A isoforms was investigated using substrates 4-methylumbelliferone (4MU), estradiol and SN-38, the rate of 4MU glucuronide formation was significantly increased, but that of estradiol glucuronide formation was unchanged.

Epigenetic assessment of environmental chemicals detected in maternal peripheral and cord blood samples.

Epigenetic alteration is an emerging paradigm underlying the long-term effects of chemicals on gene functions. Various chemicals, including organophosphate insecticides and heavy metals, have been detected in the human fetal environment. Epigenetics by DNA methylation and histone modifications, through dynamic chromatin remodeling, is a mechanism for genome stability and gene functions.

Effects of 1-O-hexyl-2,3,5-trimethylhydroquinone on carbon tetrachloride-induced hepatic cirrhosis in rats.

Aim: The present study was undertaken to evaluate the effects of 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), a synthesized vitamin E derivative, on carbon tetrachloride (CCl(4))-induced cirrhosis.

Methods: Rats were treated with hypodermic injections of CCl(4) twice a week to induce the hepatic cirrhosis, and given drinking water containing HTHQ or solvent. Primary cultures of rat hepatocytes were performed to evaluate the effects of HTHQ on the expression of inducible nitric oxide synthase (iNOS).

Enhanced expression of naofen in kidney of streptozotocin-induced diabetic rats: possible correlation to apoptosis of tubular epithelial cells.

Background: Hyperglycemia/high glucose may induce apoptosis in diabetic kidney, but the mechanism is not fully understood. Naofen was found as a Shiga toxin (Stx)-2-related protein. Based on renal dysfunction in infection with Stx-producing Escherichia coli and on participation of naofen in apoptosis of human embryonic kidney cells, the present study was undertaken to investigate the mechanism of renal dysfunction in diabetes mellitus with particular reference to naofen.

Determination of phthalates in diet and bedding for experimental animals using gas chromatography-mass spectrometry.

We have developed a gas chromatography-mass spectrometry method to measure five phthalates (dibutyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, and diisononyl phthalate) in diets and beddings for experimental animals. The recoveries from diets and beddings spiked with five phthalates were 98.8%-148% with coefficients of variation of 0.

Tacrolimus hydrate ointment inhibits skin plasma extravasation in rats induced by topical m-xylene but not capsaicin.

Tacrolimus ointment is used to treat various chronic inflammatory skin diseases. However, the effect of this ointment on acute neurogenic inflammation in the skin remains to be fully elucidated. Topical capsaicin and m-xylene produce tachykinin release from sensory nerves in the skin, resulting in skin plasma leakage.

1-Aminocyclopropanecarboxylic acid, an antagonist of N-methyl-D-aspartate receptors, causes hypotensive and antioxidant effects with upregulation of heme oxygenase-1 in stroke-prone spontaneously hypertensive rats.

1-Aminocyclopropanecarboxylic acid (ACPC) has been shown to protect neurons against glutamate-induced neurotoxicity by reducing N-methyl-D-aspartate (NMDA) receptor activation. Recent studies have demonstrated that several antagonists of NMDA receptors have important cardiovascular effects. In this study, we examined whether the cardiovascular effects of ACPC involve the role of heme oxygenase-1 (HO-1) and its antioxidant effect in stroke-prone spontaneously hypertensive rats (SHRSP).