Early changes in serum interleukin-6 levels in extremely premature newborns for detecting fetal inflammation.

BACKGROUND: Fetal inflammatory response syndrome (FIRS) is defined by elevated levels of inflammatory cytokines circulating in fetal blood, which may result in preterm morbidities. Serum interleukin-6 (IL-6) level has been reported to be a good indicator of FIRS; however, changes in IL-6 levels after birth remain to be elucidated. Herein, we characterized early changes in serum IL-6 levels in extremely premature newborns (EPNs, < 28 wks gestation), and then determined the cut-off values for detecting fetal inflammation at each postnatal epoch. METHODS: In this single-center study, 49 EPNs were retrospectively studied. Serum IL-6 measurements are routinely performed at delivery, 1-3, 6-12, and 24-36 h of life. Receiver operating characteristic (ROC) curve analyses were performed for detecting the presence of funisitis, the histologic counterpart of FIRS. RESULTS: Overall, serum IL-6 levels were significantly elevated at 1-3 (298 [31-4719] pg/mL) and 6-12 (29 [2-12,635] pg/mL) hours of life, then returned to at-delivery levels at 24-36 h of life. When comparing serum IL-6 levels at each postnatal epoch, the levels at delivery, 1-3, and 6-12 h of life were significantly higher in the EPNs with funisitis. Serum IL-6 cut-off values at delivery, 1-3, 6-12, and 24-36 h of life for the presence of funisitis were 20, 572, 290, and 13 pg/mL with area under ROCs of 0.75, 0.71, 0.68, and 0.53, respectively. CONCLUSIONS: Serum IL-6 levels in EPNs significantly increase early after birth, then decrease to at-delivery levels by 24-36 h of life. Therefore, postnatal age-dependent cut-off values of serum IL-6 might be considered for detecting fetal inflammation with confirmed funisitis.

A Fully Automated Deep-Learning Model for Predicting the Molecular Subtypes of Posterior Fossa Ependymomas Using T2-Weighted Images.

PURPOSE: We aimed to develop and validate a deep learning (DL) model to automatically segment posterior fossa ependymoma (PF-EPN) and predict its molecular subtypes [Group A (PFA) and Group B (PFB)] from preoperative MR images. EXPERIMENTAL DESIGN: We retrospectively identified 227 PF-EPNs (development and internal test sets) with available preoperative T2-weighted (T2w) MR images and molecular status to develop and test a 3D nnU-Net (referred to as T2-nnU-Net) for tumor segmentation and molecular subtype prediction. The network was externally tested using an external independent set [n = 40; subset-1 (n = 31) and subset-2 (n =9)] and prospectively enrolled cases [prospective validation set (n = 27)]. The Dice similarity coefficient was used to evaluate the segmentation performance. Receiver operating characteristic analysis for molecular subtype prediction was performed. RESULTS: For tumor segmentation, the T2-nnU-Net achieved a Dice score of 0.94 ± 0.02 in the internal test set. For molecular subtype prediction, the T2-nnU-Net achieved an AUC of 0.93 and accuracy of 0.89 in the internal test set, an AUC of 0.99 and accuracy of 0.93 in the external test set. In the prospective validation set, the model achieved an AUC of 0.93 and an accuracy of 0.89. The predictive performance of T2-nnU-Net was superior or comparable to that of demographic and multiple radiologic features (AUCs ranging from 0.87 to 0.95). CONCLUSIONS: A fully automated DL model was developed and validated to accurately segment PF-EPNs and predict molecular subtypes using only T2w MR images, which could help in clinical decision-making.

Enantioseparation of P-Stereogenic 1-Adamantyl Arylthiophosphonates and Their Stereospecific Transformation to 1-Adamantyl Aryl-H-phosphinates.

A focused library of 1-adamantyl arylthiophosphonates was prepared in racemic form. An enantioseparation method was developed for P-stereogenic thiophosphonates using (S)-1-phenylethylamine as the resolving agent. Under optimized conditions, three out of the five arylthiophosphonates were prepared in enantiopure form (ee > 99%). The subsequent desulfurization of optically active arylthiophosphonates gave the corresponding H-phosphinates without significant erosion of enantiomeric purity (ee = 95-98%). Hence, this reaction sequence can be considered an alternative method for the preparation of 1-adamantyl aryl-H-phopshinates. The absolute configuration of the (S)-1-adamantyl phenylphosphonothioic acid was assigned using single-crystal XRD and it allowed the confirmation that the removal of the P = S group proceeds with retention of configuration. The organocatalytic applicability of (S)-1-adamantyl phenylphosphonothioic acid was also evaluated as a P-stereogenic Brønsted acid.

Variable response of cholinesterase activities following human exposure to different types of organophosphates.

We investigated the red blood cell (RBC) acetylcholinesterase (AChE) activities and butyrylcholinesterase (BChE) activities at presentation to the emergency department (ED) and at 24 h after presentation following poisoning by dichlorvos, fenitrothion, or ethyl p-nitrophenol thio-benzene phosphonate (EPN). Although the patients from different groups had similar characteristics at presentation such as time interval from ingestion to presentation to the ED and the amount of organophosphate ingested, the dichlorvos group had significantly lower BChE levels than the fenitrothion group and lower RBC cholinesterase activity than the EPN group. Patients poisoned with EPN or dichlorvos had significantly higher inhibition of BChE activities from baseline than RBC AChE activities at presentation. Twenty four hours after administration of pralidoxime, RBC AChE activities had increased in patients in the dichlorvos and EPN groups, while RBC AChE activities had slightly decreased in the fenitrothion group. BChE activities increased significantly in the dichlorvos group but decreased in the EPN group. The recovery patterns of RBC AChE and BChE activities did not match in any particular individual. This study showed that the patterns of inhibition and recovery of the activities of two cholinesterases after treatment are highly variable according to the organophosphate and in different individuals.

Enantiopure cyclic O-substituted phenylphosphonothioic acid: synthesis and chirality-recognition ability.

As a new acidic selector (resolving agent), we synthesized an enantiopure O-alkyl phenylphosphonothioic acid with a seven-membered ring ((R)-5), which was designed on the basis of the results for the enantioseparation of 1-arylethylamine derivatives with acyclic O-ethyl phenylphosphonothioic acid (I). The phosphonothioic acid (R)-5 showed unique chirality-recognition ability in the enantioseparation of 1-naphthylethylamine derivatives, aliphatic secondary amines, and amino alcohols; the ability was complementary to that of I. The X-ray crystallographic analyses of the less- and more-soluble diastereomeric salts showed that hydrogen-bonding networks in the salt crystals are 2(1) -column-type with a single exception which is cluster-type. In the cases of the 2(1) -column-type crystals, stability of the crystals is firstly governed by hydrogen bonds to form a 2(1) -column and secondly determined by intra-columnar T-shaped CH/π interaction(s), intra-columnar hydrogen bond(s), inter-columnar van der Waals interaction and/or inter-columnar T-shaped CH/π interaction(s). In contrast, the cluster-type salt crystal is stabilized by the assistance of inter-cluster T-shaped CH/π and van der Waals interactions. To realize still more numbers of intra- and inter-columnar and -cluster T-shaped CH/π interactions, the seven-membered ring of (R)-5 plays a considerable role.

Separation and aquatic toxicity of enantiomers of the organophosphorus insecticide O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN).

Enantioselectivity in separation and toxicity of chiral pesticides has become important research areas in environmental science, because these studies give a deeper insight into the environmental effect of chiral pesticides. In this study, enantiomeric separation of the organophosphorus pesticide and acaricide O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN) was investigated by chiral high-performance liquid chromatography (HPLC) with two chiral stationary phases. The racemate and separated enantiomers of EPN were tested for aquatic toxicities assay using Daphnia magna and zebrafish (Danio rerio) embryo test. The enantiomers of EPN were completely separated on Chiralpak AD and Chiralpak AS columns coupled with a circular dichroism detector at 236 nm. Better separations were achieved with lower temperatures (e.g., 20°C) and lower levels of polar modifiers (e.g., 1%). A significant difference was found between the enantiomers in their acute aquatic toxicity; the (+)-enantiomer was about 10 times more toxic than its antipode. On the contrary, the (-)-enantiomer induced crooked body, yolk sac edema and pericardial edema significantly more than (+)-enantiomer in the zebrafish embryo test. These results suggest that biological toxicity of chiral pesticides should be assessed by using their individual enantiomers with more comprehensive methods.

Monoclonal antibody-based enzyme-linked immunosorbent assays for the organophosphorus insecticide O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN).

This study aimed at developing competitive direct and indirect enzyme-linked immunosorbent assays (ELISAs) for the organophosphorus insecticide O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN) using a monoclonal antibody (mAb). Of the five EPN derivatives (haptens) prepared for use as an immunogen or as a competitor, two of them were used as the immunogen for the production of the mAbs. By using the antibody with the highest specificity and a coating antigen (hapten-OVA conjugate), a competitive indirect ELISA was developed, which showed an IC(50) of 2.9 ng/mL with a detection limit of 0.3 ng/mL. A competitive direct ELISA using a different antibody and an enzyme tracer was also developed, which showed an IC(50) of 0.6 ng/mL with a detection limit of 0.09 ng/mL. The mAbs in both assays showed negligible cross-reactivity with other organophosphorus pesticides. The recoveries of EPN from spiked samples determined by the developed ELISA ranged from 59 to 143%. Dilution of the samples improved the recovery. The assay performance of the present ELISAs based on the mAb was compared with that of the EPN ELISAs based on polyclonal antibodies (pAbs) that had been developed previously and was found to be better in dynamic response.

Biosensor for direct determination of fenitrothion and EPN using recombinant Pseudomonas putida JS444 with surface-expressed organophosphorous hydrolase. 2. Modified carbon paste electrode.

A whole cell-based amperometric biosensor for highly selective, sensitive, rapid, and cost-effective determination of the organophosphate pesticides fenitrothion and ethyl p-nitrophenol thio-benzene phosphonate (EPN) is discussed. The biosensor comprised genetically engineered p-nitrophenol (PNP)-degrading bacteria Pseudomonas putida JS444 anchoring and displaying organophosphorous hydrolase (OPH) on its cell surface as biological sensing element and carbon paste electrode as the amperometric transducer. Surface-expressed OPH catalyzed the hydrolysis of organophosphorous pesticides such as fenitrothion and EPN to release PNP and 3-methyl-4- nitrophenol, respectively, which were subsequently degraded by the enzymatic machinery of P. putida JS444 through electrochemically active intermediates to the TCA cycle. The electro-oxidization current of the intermediates was measured and correlated to the concentration of organophosphates. Operating at optimum conditions, 0.086 mg dry wt of cell operating at 600 mV of applied potential (vs Ag/AgCl reference) in 50 mM citrate phosphate buffer, pH 7.5, with 50 muM CoCl2 at room temperature, the biosensor measured as low as 1.4 ppb of fenitrothion and 1.6 ppb of EPN. There was no interference from phenolic compounds, carbamate pesticides, triazine herbicides, or organophosphate pesticides without nitrophenyl substituent. The service life of the biosensor and the applicability to lake water were also demonstrated.

A multiresidue method for the analysis of pesticide residues in polished rice (Oryza sativa L.) using accelerated solvent extraction and gas chromatography and confirmation by mass spectrometry.

An analytical procedure using accelerated solvent extraction and gas chromatography with an electron capture detector has been optimized to simultaneously determine the residue of two insecticides (diazinon and EPN) and one fungicide (isoprothiolane) in polished rice and was confirmed by GC-mass spectrometry. Several parameters, including temperature, pressure, solvent ratio, cell size and cell cycle, were thoroughly investigated to find the optimal extraction conditions. The average recoveries of the three pesticides were between 82.7 and 126.4% at spiking levels of 0.1 and 0.5 ppm. The relative standard deviations were less than 7% for all of the recovery tests. The optimum accelerated solvent extraction operating conditions were 100 degrees C, 1500 atm, acetone-n-hexane (20:80 v/v) as the extraction solvent, two cycles, and a cell size of 33 ml. The total extraction time was approximately 20 min. The optimized procedure has also been applied to the determination of diazinon, isoprothiolane and EPN in real rice samples. In conclusion, accelerated solvent extraction was used for the first time for the analysis of diazinon, isoprothiolane and EPN in polished rice and offers the possibility of a fast and simple process for obtaining a quantitative extraction of the studied pesticides.

Extremely sensitive biomarker of acute organophosphorus insecticide exposure.

Egasyn-beta-glucuronidase complex is located at the luminal site of liver microsomal endoplasmic reticulum. When organophosphorus insecticides (OP) are incorporated into the liver microsomes, they become tightly bound to egasyn, a carboxylesterase isozyme, and subsequently, beta-glucuronidase (BG) is dissociated and released into blood. Consequently, the increase in plasma BG activity becomes a good biomarker of OP exposure. Thus, the single administration of EPN (O-ethyl O-p-nitrophenylphenylphosphonothioate), acephate and chlorpyrifos increased plasma BG activity in approximately 100-fold the control level in rats. The increase in plasma BG activity after OP exposure is a much more sensitive biomarker of acute OP exposure than acetylcholinesterase (AChE) inhibition.

Mutagenesis of organophosphorus hydrolase to enhance hydrolysis of the nerve agent VX.

Organophosphorus hydrolase (OPH) is capable of hydrolyzing a wide variety of organophosphorus pesticides and chemical warfare agents. However, the hydrolytic activity of OPH against the warfare agent VX is less than 0.1% relative to its activity against parathion and paraoxon. Based on the crystal structure of OPH and the similarities it shares with acetylcholinesterase, eight OPH mutants were constructed with the goal of increasing OPH activity toward VX. The activities of crude extracts from these mutants were measured using VX, demeton-S methyl, diisopropylfluoro-phosphate, ethyl parathion, paraoxon, and EPN as substrates. One mutant (L136Y) displayed a 33% increase in the relative VX hydrolysis rate compared to wild type enzyme. The other seven mutations resulted in 55-76% decreases in the relative rates of VX hydrolysis. There was no apparent relationship between the hydrolysis rates of VX and the rates of the other organophosphorus compounds tested.

Characterization of a novel organophosphorus hydrolase from Nocardiodes simplex NRRL B-24074.

We characterized a novel organophosphorus hydrolase (OPH) activity expressed by Nocardiodes simplex NRRL B-24074, a member of a coumaphos-degrading microbial consortium from cattle dip waste. Like the previously characterized OPH from Nocardia sp. strain B- (NRRL B- 16944), OPH activity in N. simplex is located in the cytoplasm and is expressed constitutively. The purified enzyme is monomeric, has a native molecular size of 45,000 Da and has a specific activity toward ethyl parathion of 33 micromole/min x mg protein. Km constants for the enzyme with the structurally related organophosphate pesticides ethyl parathion and EPN were 100 microM and 345 microM, respectively. Although OPH activity in extracts did not require the addition of divalent cations, the purified enzyme lost activity during dialysis against phosphate buffer and this activity could be restored after incubation in buffer containing either CoSO4 or CuSO4. Our results suggest that OPH activity in N. simplex is distinct from other known OPHs and that the responsible gene is unrelated to known genes.

Toxicological significance in the cleavage of esterase-beta-glucuronidase complex in liver microsomes by organophosphorus compounds.

Egasyn is an accessory protein of beta-glucuronidase (beta-G) in the liver microsomes. Liver microsomal beta-G is stabilized within the luminal site of the microsomal vesicles by complexation with egasyn which is one of the carboxylesterase isozymes. We investigated the effects of organophosphorus compounds (OPs) such as insecticides on the dissociation of egasyn-beta-glucuronidase (EG) complex. The EG complex was easily dissociated by administration of OPs, i.e. fenitrothion, EPN, phenthionate, and bis-beta-nitrophenyl phosphate (BNPP), and resulting beta-G dissociated was released into blood, leading to the rapid and transient increase of plasma beta-G level with a concomitant decrease of liver microsomal beta-G level. In a case of phenthionate treatment, less increase in plasma beta-G level was observed, as compared with those of other OPs. This may be explained by the fact that phenthionate was easily hydrolyzed by carboxylesterase. Similarly, carbamate insecticides such as carbaryl caused rapid increase of plasma beta-G level. In contrast, no significant increase of plasma beta-G level was observed when pyrethroid insecticides were administered to rats. This is due to the fact that pyrethroids such as phenthrin and allethrin were easily hydrolyzed by A-esterase as well as carboxylesterase. On the other hand, addition of OPs to the incubation mixture containing liver microsomes caused the release of beta-G from microsomes to the medium. From these in vivo and in vitro data, it is concluded that increase of the plasma beta-G level after OP administration is much more sensitive biomarker than cholinesterase inhibition to acute intoxication of OPs and carbamates.

Acute toxicity, accumulation and excretion of organophosphorous insecticides and their oxidation products in killifish.

Acute toxicity, accumulation and excretion of four organophosphorous insecticides (diazinon, malathion, fenitrothion and EPN) and their oxidation products (diazinon oxon, malaoxon, fenitrothion oxon and EPN oxon) were studied for killifish (Oryzias latipes). The 48-hr LC50 was 4.4 mg l-1 for diazinon, 1.8 mg l-1 for malathion, 3.5 mg l-1 for fenitrothion, 0.58 mg l-1 for EPN, 0.22 mg l-1 for diazinon oxon, 0.28 mg l-1 for malaoxon, 6.8 mg l-1 for fenitrothion oxon, and 0.16 mg l-1 for EPN oxon. The bioconcentration factors (BCF) of diazinon oxon 0.5, malaoxon 1.1, fenitrothion oxon 2.3 and EPN oxon 11 in the whole body of the fish were much lower than those of diazinon 49, malathion 11, fenitrothion 122 and EPN 1124. As reference data, partition coefficients between n-octanol and water (Pow) were measured for these chemicals. The BCF values of each pesticide and its oxidation product were consistent with the Pow values. The excretion rate constants (k) from the whole body of the fish were 0.12 hr-1 for diazinon, 0.27 hr-1 for malathion, 0.11 hr-1 for fenitrothion, 0.02 hr-1 for EPN, 0.30 hr-1 for fenitrothion oxon and 0.59 hr-1 for EPN oxon. The rates of diazinon oxon and malaoxon could not be measured, but were presumed to be as rapid as or more rapid than those of fenitrothion oxon and EPN oxon. The results suggest that the contamination of fish and other aquatic organisms by the oxidation products in the environment is very low.

Lack of promoting activity of four pesticides on induction of preneoplastic liver cell foci in rats.

Four pesticides were examined for hepatopromoting activity using a medium-term bioassay based upon induction of glutathione S-transferase placental form (GST-P) positive foci in the rat liver. Male F344 rats were initially injected with diethylnitrosamine (DEN; 200 mg/kg body weight) intraperitoneally and 2 weeks later were treated with O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN; 75 and 150 ppm), diazinon (500 and 1,000 ppm), phenthoate (500 and 1,000 ppm), or iprobenfos (500 and 1,000 ppm) in the diet for 6 weeks and then killed, all rats being subjected to partial hepatectomy at week 3. All of the pesticides gave negative results, the numbers and areas of GST-P positive foci not exceeding the control values for animals given DEN alone. Indeed, a significant reduction of foci development was seen for EPN (75 ppm). These findings provide experimental evidence that the presently examined four pesticides do not have hepatocarcinogenic potential in rats.

Protective effect of a high protein diet against the toxicity of some organophosphorus compounds in albino rats.

The present investigation deals with determining the efficacy of a high protein diet (HPD) in combating toxicity in albino rats of some organophosphorus compounds (OPCs) that follow dissimilar metabolic patterns in a living system. As assessed by an increase or decrease in the levels of some biochemical and nutritional parameters, the high protein diet containing 59% protein seems to have a beneficial effect in alleviating toxicity of low but prolonged doses of OPCs over the standard diet (SD) containing 19% protein. OPCs undergoing direct detoxication in a living system like diisopropyl phosphoro-fluoridate (DFP) appear to be more susceptible to HPD than those undergoing biotoxication like EPN (O-ethyl O-p-nitrophenyl phenyl-phosphonothioate) and malathion (S-(1,2-dicarbethoxyethyl) O,O-dimethyldithiophosphate).

Mechanisms of joint neurotoxicity of n-hexane, methyl isobutyl ketone and O-ethyl O-4-nitrophenyl phenylphosphonothioate in hens.

The joint neurotoxic action of simultaneous exposure to vapors of n-hexane and methyl iso-butyl ketone (MiBK) and dermally applied O-ethyl O-nitrophenyl phenylphosphonothioate (EPN) was studied in groups of five adult hens. Four groups of hens were concurrently exposed to a dermal 2.5 mg/kg of EPN, 1000 ppm of n-hexane and 100, 250, 500 or 1000 ppm of MiBK. Two groups were each exposed to binary mixtures of a dermal dose of 2.5 mg/kg of EPN and 250 ppm of MiBK or 1000 ppm of n-hexane. Another three groups of hens were exposed to either 250 ppm of MiBK, 1000 ppm of n-hexane or a dermal dose of 2.5 mg/kg of EPN. A Group of hens was kept untreated. All hens were terminated after 30 days of treatment. Hens exposed to MiBK or n-hexane vapor did not exhibit any toxicity signs. In contrast, hens treated with EPN alone or in combination with n-hexane and/or MiBK developed acute cholinergic and delayed neurotoxicity signs. Hen brain acetylcholinesterase and neurotoxic esterase activities were inhibited in hens treated concurrently with EPN, n-hexane and MiBK. MiBK alone or in combination with EPN and n-hexane induced liver microsomal cytochrome P-450 content and phenobarbital-inducible cytochrome P-450 enzyme activities. Microsomes from hens treated with EPN, n-hexane, MiBK or mixtures of EPN, n-hexane and MiBK significantly enhanced the biotransformation of EPN to the more neurotoxic oxidation metabolite O-ethyl O-4-nitrophenyl phenylphosphonate.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation and degradation of the phosphorothionate insecticides parathion and EPN by rat brain.

Cytochrome P-450-dependent monooxygenases are known to activate phosphorothionate insecticides to their oxon (phosphate) analogs by oxidative desulfuration. These activations produced potent anticholinesterases, decreasing the I50 values to rat brain acetylcholinesterase almost 1000-fold (from the 10(-5) M range to the 10(-8) M range). Since the usual cause of death in mammals from organophosphorus insecticide poisoning is respiratory failure resulting, in part, from a failure of the respiratory control center of the brain, we investigated the ability of rat brain to activate and subsequently degrade two phosphorothionate insecticides, parathion (diethyl 4-nitrophenyl phosphorothioate) and EPN (ethyl 4-nitrophenyl phenylphosphonothioate). Microsomes from specific regions (cerebral cortex, corpus striatum, cerebellum, and medulla/pons) of the brains of male and female rats and from liver were incubated with the phosphorothionate and an NADPH-generating system. Oxon production was quantified indirectly by the amount of inhibition resulting in an exogenous source of acetylcholinesterase added to the incubation mixture as an oxon trap. The microsomal activation specific activity was low for brain when compared to liver [0.23 to 0.44 and 5.1 to 12.0 nmol.min-1.(g tissue)-1 respectively]. The mitochondrial fraction of the brain possessed an activation activity for parathion similar to that of microsomes [about 0.35 nmol.min-1.(g tissue)-1 for each fraction], but mitochondrial activity was slightly greater than microsomal activity for EPN activation [0.53 to 0.58 and 0.23 to 0.47 nmole.min-1.(g tissue)-1]. Whole homogenates were tested for their ability to degrade paraoxon and EPN-oxon (ethyl 4-nitrophenyl phenylphosphonate), quantitated by 4-nitrophenol production. Specific activity for oxon degradation in liver was greater than that in brain [31 to 74 and 1.1 to 10.7 nmole.min-1.(g tissue)-1 respectively]. Overall, the brain and liver had about 1.5- to 12-fold higher specific activities for degradation than activation depending on the compound used. These findings demonstrate that the brain possesses both phosphorothionate activation and oxon degradation abilities, both of which may be significant during exposures to organophosphorus insecticides.