Aristolochic acids exposure was not the main cause of liver tumorigenesis in adulthood

Aristolochic acids (AAs) have long been considered as a potent carcinogen due to its nephrotoxicity. Aristolochic acid I (AAI) reacts with DNA to form covalent aristolactam (AL)-DNA adducts, leading to subsequent A to T transversion mutation, commonly referred as AA mutational signature. Previous research inferred that AAs were widely implicated in liver cancer throughout Asia. In this study, we explored whether AAs exposure was the main cause of liver cancer in the context of HBV infection in mainland China. Totally 1256 liver cancer samples were randomly retrieved from 3 medical centers and a refined bioanalytical method was used to detect AAI-DNA adducts. 5.10% of these samples could be identified as AAI positive exposure. Whole genome sequencing suggested 8.41% of 107 liver cancer patients exhibited the dominant AA mutational signature, indicating a relatively low overall AAI exposure rate. In animal models, long-term administration of AAI barely increased liver tumorigenesis in adult mice, opposite from its tumor-inducing role when subjected to infant mice. Furthermore, AAI induced dose-dependent accumulation of AA-DNA adduct in target organs in adult mice, with the most detected in kidney instead of liver. Taken together, our data indicate that AA exposure was not the major threat of liver cancer in adulthood.

Association of intrauterine benzo[a]pyrene exposure with benzo[a]pyrene diolepoxide (BPDE)-DNA adduct levels and pancreatic functional impairment in offspring rats / 预防医学

Objective@#To investigate the benzo[a]pyrene ( B[a]P ) diolepoxide ( BPDE )-DNA adduct levels in offspring rats with intrauterine exposure to B[a]P, and examine the effects of BPDE-DNA adduct levels on pancreatic functional impairment and glucose metabolism in offspring rats. @*Methods@#Forty pregnant rats were randomly divided into the blank control group, standard-dose group, low-dose group, medium-dose group and high-dose group (daily dose of 0, 2, 200, 800, 1 600 μg/kg B[a]P, respectively), of 8 animals in each group. Rats in the B[a]P treatment groups were administered by oral gavage with a mixture of B[a]P and corn oil at a dose of 0.2 mL/100 g body weight since day 1 of pregnancy until 21 days after delivery, while rats in the blank control group were given the same volume of coin oil by oral gavage. The BPDE-DNA adduct levels were measured and the pancreatic development was observed in the offspring rats 2 and 21 days and 12 weeks after birth, and the correlation between pancreas volume index and dose of exposure to B[a]P was examined using Spearman's rank correlation analysis. In addition, glucose metabolism was measured in offspring rats 12 months after birth using glucose tolerance test ( GTT ) and insulin tolerance test ( ITT ). @*Results@#There was no abnormal appearance, death, abortion or preterm birth in pregnant or offspring rats in the five groups, and no significant differences were seen in activity, diet, drinking water or mental status in rats. The greatest level of BPDE-DNA adducts was measured in offspring rats 2 days after birth, with median levels ( interquartile range ) of 1 089.60 ( 586.10 ) to 1 405.49 ( 346.47 ) pg/mL, and no BPDE-DNA adducts were found in offspring rats 12 weeks after birth. The pancreas volume index correlated negatively with the dose of exposure to B[a]P in offspring rats 2 ( rs=-0.620, P=0.001 ) and 21 days after birth ( rs=-0.801, P=0.001 ). Hypoplasia of pancreas with loose tissues was seen in offspring rats 2 days after birth, while well pancreatic development was found in offspring rats 12 weeks after birth, with tight exocrine portion. GTT showed an increase in glucose levels in offspring rats in all five groups following abdominal injection of glucose and declined 30 min post-injection ( F=365.578, P<0.001 ), and ITT showed a tendency towards a decline in glucose levels in offspring rats in all five groups ( F=461.215, P<0.001 ).@*Conclusions@#The levels of BPDE-DNA adducts in offspring rats increase with the dose of intrauterine B[a]P exposure, and insulin resistance and impaired glucose tolerance occur 12 months post-exposure to B[a]P. Intrauterine B[a]P exposure affects pancreatic development in offspring rats and causes abnormal glucose metabolism in adult offspring rats.

The role of serum pyrrole-protein adduct in evaluating the severity and predicting the anticoagulant efficacy in patients with pyrroidine alkaloid-related hepatic sinusoidal obstruction syndrome / 中华消化杂志

Objective:To explore the role of serum pyrrole-protein-adduct (PPA) in evaluating the severity and predicting the anticoagulant efficacy in patients with pyrrolidine alkaloid-related hepatic sinusoidal obstruction syndrome (PA-HSOS).Methods:From April 2018 to December 2019, the data of 48 patients with PA-HSOS admitted and treated at Drum Tower Hospital, Affiliated Medical College of Nangjing University were collected, which included PPA level, portal vein velocity (PVV), ascites grading, PA-HSOS severity grading (according to the new severity grading criteria for suspected hepatic sinusoidal obstruction syndrome in adults by the European Society of Blood and Bone Marrow Transplantation and adjusted) and the outcome of anticoagulation. Patients with acute onset (onset of symptoms within 1 month after consuming pyrrolizidine alkaloid-containing plants) were taken as research subjects. The combination of PPA with PVV or with ascites classification of PA-HSOS severity assessment model was fitted by logistic regression, and the logit values of 2 combination models were calculated, the formula was logit 1=0.034×PPA(nmol/L)+ 0.055×PVV(cm/s)-3.287, logit 2=0.039×PPA(nmol/L)-2.712×ascites grade 2 (Yes=1, No=0)-0.388×ascites grade 3 (Yes=1, No=0)-0.899. The patients received initial anticoagulation therapy at Drum Tower Hospital, Affiliated Medical College of Nanjing University were selected as research subjects. The anticoagulant efficacy prediction model of combination of PPA with serum creatinine (SCR) and with hepatic venous pressure gradient (HVPG) was fitted by logistic regression, and the logit value was calculated, the formula was logit 3=0.013×PPA(nmol/L)+ 0.064×SCR (mol/L)+ 0.542×HVPG (mmHg, 1 mmHg=0.133 kPa)-16.005. The predictive value of PPA in evaluating the severity of PA-HSOS and anticoagulant efficacy was evaluated. Receiver operating characteristic curve analysis was performed for statistical analysis. Results:The serum PPA level of 48 patients was 10.81 nmol/L (3.91 nmol/L, 32.04 nmol/L). Among them, 33 cases (68.8%) were mild PA-HSOS, 3 cases (6.2%) were moderate PA-HSOS, no severe PA-HSOS case and 12 cases (25.0%) were very severe PA-HSOS. Among 23 patients received initial anticoagulant therapy at Drum Tower Hospital, Affiliated Medical College of Nanjing University and with complete data, 8 patients responded and survived, and 15 patients did not respond (5 patients died, 1 patient relieved after continue anticoagulant therapy, and 9 patients survived after switching to anticoagulant therapy and transjugular intrahepatic portosystemic shunt (TIPS) treatment). One patient without initial anticoagulant therapy, survived after TIPS treatment because of the progress of the disease. Area under the curve (AUC) of PPA to assess the severity of acute onset PA-HSOS was 0.75, 95% confidence interval ( CI) was 0.52 to 0.98 ( P=0.047). When PPA≥45.519 nmol/L, the specificity and sensitivity in evaluating severe and very severe PA-HSOS was 100.0% and 57.1%, respectively. AUC of combination of PPA and PVV to assess the severity of PA-HSOS was 0.77, 95% CI was 0.55 to 1.00 ( P=0.032). When the logit of combination model≥0.180, the specificity and sensitivity in evaluating severe and very severe PA-HSOS was 71.4% and 81.8%, respectively. AUC of combination of PPA and ascites grade (grade 1, 2 or 3) to assess the severity of PA-HSOS was 0.85, 95% CI was 0.63 to 1.00 ( P=0.005). When the logit of combination model≥0.347, the specificity and sensitivity in evaluating severe and very severe PA-HSOS was 85.7% and 92.0%, respectively. AUC of combination of PPA, SCR and HVPG to predict anticoagulation efficacy was 0.85, 95% CI was 0.69 to 1.00 ( P=0.009). When the logit≥0.393, the specificity and sensitivity in predicting anticoagulation efficacy was 62.5% and 91.7%, respectively. Conclusions:PPA can be used to assess the severity of acute onset PA-HSOS patients, and combined with ascites grading can significantly improve its efficiency. PPA combined with SCR and HVPG can better predict anticoagulant efficacy.

Kinetic study of pyrrolizidine alkaloid-derived pyrrole-protein adducts in rats after intragastric administration of Gynura japonica / 药学学报

Recently, hepatic sinusoidal obstruction syndrome (HSOS) induced by misuse of Gynura japonica has increased and gained global attention. Large amounts of pyrrolizidine alkaloids (PAs) are present in G. japonica; these PAs are metabolically activated to generate pyrrole-protein adducts (PPAs). In this study, male SD rats were treated orally with a single dose of G. japonica extract (GJE) at 0.062 5, 0.25, 0.5, 1, and 2 g·kg-1. Blood was collected from the orbital venous plexus at 2, 12, 24 and 48 h, and at 48 h after treatment the rats were anesthetized with isoflurane and livers were collected for hematoxylin & eosin staining. The kinetics of PPAs at different doses were studied at 10, 20, 30 min, 1, 2, 4, 6, 12, 24 h, and 48 h, after a single gavage of GJE. The experimental scheme was approved by the ethics committee of animal experiments of Shanghai University of Traditional Chinese Medicine (PZSHUTCM190912019). The concentration of PPAs in serum was determined by liquid chromatography-mass spectrometry (LC-MS). Kinetic data were processed by using the non-compartmental pharmacokinetics data analysis software program PK solutions 2™. The results demonstrate that the concentration of PPAs increased with the dose of GJE and positively correlated with the severity of liver injury. The elimination rate of PPAs in rats was significantly prolonged at higher doses. The level of PPAs and their clearance rate may serve as useful references for the detoxification of PAs-induced injuries.

Adsorción de un complejo de hierro sobre nanocristales de dióxido de titanio utilizando un residuo piridina / Adsorption of an iron complex on nanocrystals of titanium dioxide using a pyridine residue / Adsorção de um complexo de ferro em nanocristais de dióxido de titânio usando um resíduo de piridina

Resumen Debido a que los fenómenos de adsorción de tinturas sobre óxidos metálicos son de gran importancia en la búsqueda de sistemas de conversión de energía solar, en este trabajo se presenta el comportamiento espectroscópico y electroquímico del complejo [Fe(pytpy2)] (PF6)2 (donde pytpy es 4'-(piridin-4-il)-2,2':6',2"-terpiridina) en solución fluida y anclado sobre una película delgada de nanocristales de dióxido de titanio. La constante de formación del aducto se estimó utilizando el modelo isotérmico de Langmuir y se encontró un valor de 1,03x105 M-1 para dicho complejo. El anclaje del complejo sobre la superficie del óxido metálico semiconductor se debe a la interacción del residuo de piridina con los sitios ácidos de Lewis presentes en la superficie del TiO2. Se observó que las propiedades espectroscópicas y electroquímicas del complejo no se ven modificadas por la adsorción.

Abstract Because the phenomena of adsorption of tinctures on metal oxides are of great importance in the search for solar energy conversion systems, this paper presents the spectroscopic and electrochemical behavior of the complex [Fe(pytpy2)](PF6)2 (where pytpy is 4'-(4-pyridyl)-2,2':6',2''-terpyridine) in a fluid solution and anchored on a thin film of nanocrystals of titanium dioxide. The adduct formation constant was estimated using the Langmuir isothermal model, with a value of 1.03x105 M-1 for the complex. The anchoring of the complex on the surface of the semiconductor metal oxide is due to the interaction of the pyridine residue with the Lewis acid sites presented on the TiO2 surface. Results indicated that the spectroscopic and electrochemical properties of the complex are not modified by the adsorption.

Resumo Os fenômenos de adsorção de tinturas em óxidos metálicos são de grande importância na busca por sistemas de conversão de energia solar, motivo pelo qual neste trabalho o comportamento espectroscópico e eletroquímico do complexo [Fe(pytpy2)] (PF6)2 (onde pytpy é 4'-(piridin-4-il)-2,2':6',2"-terpiridina) em uma solução fluida e ancorada em um filme fino de nanocristais de dióxido de titânio. A constante de formação de aduto foi estimada pelo modelo isotérmico de Langmuir, com valor de 1.03x105 M-1 para o referido complexo. A ancoragem do complexo na superfície do óxido de metal semicondutor é devida à interação do resíduo de piridina com os sítios de ácido de Lewis presentes na superfície do TiO2, observando que as propriedades espectroscópicas e eletroquímicas do complexo não são modificadas pela adsorção.

Diels-Alder Type Adducts from Hairy Root Cultures of Morus macroura

Three Diels-Alder type adducts, guangsangon E (1), chalcomoracin (2) and sorocein I (3) were isolated from hairy root cultures of Morus macroura. The structures of the isolated compounds (1 – 3) were determined by spectroscopic method (NMR and MS), and spectral comparison to literature. Cytotoxic activities of the isolated compounds (1 – 3) were investigated against P-388 murine leukemia cell line. Guangsangon E (1) showed the most potent cytotoxicity against P-388 murine leukemia cell line with IC₅₀ value of 2.75 ± 0.32 µg/mL. To the best of our knowledge, guangsangon E (1) and sorocein I (3) were reported for the first time from the tissue cultures of M. macroura.

Two new Diels-Alder type compounds from cell cultures of Morus alba / 中草药

Objective To investigate the Diels-Alder adducts from cell suspension cultures of Morus alba. Methods A variety of column chromatography (CC) including silica gel CC, Sephadex LH-20 CC, C18 CC, and semi-preparative HPLC were used to separate Diels-Alder adducts from cell cultures of M. alba. Their structures were identified by physicochemical properties and various spectroscopic experiments, including MS, NMR, and ECD. Results Eight Diels-Alder adducts were obtained from the ethyl acetate extract of M. alba, and determined as mongolicin H (1), morbilisin J (2), mongolicin F (3), mulberrofuran G (4), artonin D (5), kuwanon R (6), morbilisin C (7), and mulberrofuran E (8). Conclusion Compounds 1-8 are all Diels-Alder adducts and show medium cytotoxic activity, and compounds 1 and 2 are new compounds.

Preparation of divinylsulfone-glutathione adducts and their reactive activities with DNA in vitro / 中国药理学与毒理学杂志

OBJECTIVE To prepare the glutathione adducts of divinylsulfone (DVS), which is an important oxidative metabolism product of SM in vivo, and to investigate their reactive capability with DNA in vitro. METHODS The mustard sulfoxide (SMO) and mustard sulfone (SMO2) were prepared by oxidation reaction using HNO3 and KMnO4 as oxidants, respectively. Then, DVS was prepared through dechlorination reaction using CaCO3 under alkaline conditions. Furthermore, the DVS-GSH adduct and DVS-GSH-purine adducts were prepared and identified using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) and nuclear magnetic resonance (NMR). Finally, the adduct reac?tion process of DVS with GSH was monitored using UPLC-MS/MS. RESULTS The DVS-GSH and GSH-DVS-purine adducts were obtained through preparative HPLC and characterized using NMR and high-resolution MS. In aqueous solution, the reactive activity of DVS with GSH was significantly higher than that of SM, and the DVS-GSH adduct had high or reactive activity, which could produce a series of adducts with adenine and guanine in DNA, and the abundance of the adenine adducts was higher than that of the guanine. CONCLUSION DVS-GSH adducts still have high reactive activity with DNA, and more attention should be paid to its potential damage to DNA.

The association between aflatoxin exposure and primary hepatocellular carcinoma risks: a case-control study in Chongqing / 中华预防医学杂志

Objective@#To investigate the association between aflatoxin exposure and primary hepatocellular carcinoma (PHC) development.@*Methods@#From December 2013 to May 2016, we selected 214 patients newly diagnosed with PHC as cases, and 214 patients as controls from three hospitals in Chongqing. Cases were confirmed with PHC diagnosis standard. And cases caused by clear reasons such as drug-induced liver injury, alcoholic liver damage, fatty liver and gallstones etiology, were excluded. Controls were included with no cancer and no digestive system disease, and recruited simultaneously with cases. Cases and controls were frequency-matched (1∶1) by same gender and age (±3 years). Peripheral blood and random urine samples were collected and analyzed for serum HBsAg status by biochemistry analyzer, and serum AFB1-ALB adduct and urinary AFB1-N7-GUA adduct by ELISA. Basic information, living habits and history of disease for patients were obtained by questionnaires. We used wilcoxon rank sum test to compare the median of serum AFB1-ALB adduct and urinary AFB1-N7-GUA adduct in cases and controls. Logistic regression analyses were performed to assess risk factors for PHC, and synergism index (S) of aflatoxin with other factors was estimated by the method of Andersson.@*Results@#There was no significant difference in age between PHC cases (50.74±9.67) years and controls (51.15±9.90) years. Logistic regression showed that the odds ratio of HBV infection for PHC development was 46.3 (95% CI: 23.3-88.0). There was a significant difference in median concentrations of serum AFB1-ALB adduct (cases vs controls: 146.23 vs 74.42 ng/g albumin, P<0.001), but no difference in median concentrations of urinary AFB1-N7-GUA adduct was observed (cases vs controls: 0.17 vs 0.14 ng/mg creatinine, P<0.210). The odd ratios for PHC risk after adjustment were 1.9 (95%CI: 1.1-3.4) for AFB1-ALB adduct, and 2.1 (95%CI: 1.0-4.2) for AFB1-N7-GUA adduct. Moreover, we observed a positive interaction of aflatoxin exposure with HBV, alcohol drinking, and diabetes. The S was 4.7 (95%CI: 2.8-7.9), 3.5 (95%CI: 1.0-12.0), and 12.4 (95%CI: 1.8-84.2), respectively for serum AFB1-ALB adduct with each of the three factors mentioned, and was 1.9 (95%CI:1.1-3.1), 2.0 (95%CI: 1.1-3.6), and 2.0 (95%CI: 1.1-3.6), respectively for urinary AFB1-N7-GUA adduct with each of the three factors mentioned.@*Conclusion@#HBV was still the main risk factor, and AFB1 exposure was also an independent risk factor for PHC in Chongqing. There was a positive interaction of aflatoxin with HBV, alcohol drinking, and diabetes.

Delayed effect of liver injury and metabolism of dimethylformamide after high exposures in rats / 中华劳动卫生职业病杂志

Objective@#To investigate the delayed effect of liver injury and metabolism of dimethylformamide (DMF) after high exposures in rats.@*Methods@#A total of 12 rats were randomly divided into four groups and 3 rats were in each group. Rats in 1d DMF+2 d delayed group were dosed for 1 day and rested for 2 days, and sacrificed at the 4th day. Rats in 3 d DMF group were dosed for 3 days and sacrificed at the 4th day. Rats in 3 d DMF+3 d delayed group were dosed for 3 days and rested for 3 days, and sacrificed at the 7th day. Rats in control group were administrated with water for 3 days, sacrificed at the 7th day. The administrated dose was 1 000 mg/kg (body weight·d) DMF by oral. The daily observation and body weight were recorded during the study period. After the experiment, the blood biochemistry, including alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , lactic dehydrogenase (LDH) , alkaline phosphatase (ALP) , total bilirubin (TBIL) etc. were detected. Liver weight, kidney weight, liver/body ratio, kidney/body ratio and pathologic examination of liver and kidney were investigated. The concentrations of hemoglobin-adduct (NMHb) were detected.@*Results@#During the period of 1~3 d, body weight growth rate of rats in each treated group had no significant difference with control rats. In the 4~6 th day of the period, rats in group 3 became thinner than before, and the body weight was negative growth (-4.22±3.29 g/d) and significant lower than that of control rats (10.33±3.21 g/d, F=30.07, P<0.05) . AST and LDH levels of 3 d DMF group were significant higher than control group (P<0.05) . Liver/body ratio in 3 d DMF+3 d delayed group were significant higher than control group (P<0.05) . The gross inspection showed 1 rat and 3 rats were observed liver injury in 3 d DMF group and 3 d DMF+3 d delayed group, respectively. Histopathological lesions of 1d DMF+2 d delayed group, 3 d DMF group and 3 d DMF+3 d delayed group were mainly spotty necrosis, focal necrosis and large necrosis of liver cells, respectively. Only NMHb level of control group was undetectable. NMHb levels in 3 d DMF+3 d delayed group were significantly higher than 3 d DMF group (F=135.46, P<0.05) .@*Conclusion@#The DMF-induced liver injury and DMF metabolism may be delayed after high DMF exposures in rats.

Combined Toxicity of an Environmental Remediation Residue, Magnetite Fe3O4 Nanoparticles/Cr(VI) Adduct / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This paper aims to elucidate the combined toxicity of magnetite nanoparticles/Chromium [MNPs/Cr(VI)] adducts.</p><p><b>METHODS</b>The HEK293 cell was exposed to either Cr(VI) or MNPs, or their adducts MNPs/Cr(VI). The cytotoxicity was evaluated by assessing the cell viability, apoptosis, oxidative stress induction, and cellular uptake.</p><p><b>RESULTS</b>The toxicity of formed adducts is significantly reduced when compared to Cr(VI) anions. We found that the cellular uptake of MNPs/Cr(VI) adduct was rare, only few particles were endocytosed from the extracellular fluid and not accumulated in the cell nucleus. On the other hand, the Cr(VI) anions entered cells, generated oxidative stress, induced cell apoptosis, and caused cytotoxicity.</p><p><b>CONCLUSION</b>The results showed minor effects of the nanoadducts on the tested cells and supported that magnetite nanoparticles could be implemented in the wastewater treatment process in which advantageous properties outweigh the risks.</p>

Characteristics of Adduct Spasmodic Dysphonia and Muscle Tension Dysphonia Using Spectrogram / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Adduct spasmodic dysphonia (ADSD) is a neurogenic and focal laryngeal dystonia resulting in a strained voice quality with spastic voice breaks. While muscle tension dysphonia (MTD) is caused by functional voice disorders, its symptoms are similar to those of ADSD. Because the approaches of treatment for ADSD and MTD are radically different, accurate evaluations are necessary for precise diagnosis. A spectrogram analysis for differentiating ADSD from MTD provides differentiations on four spectral findings (abrupt voice breaks, irregular wide-spaced vertical striations, well-defined formants and high-frequency spectral noise). The aim of this study was to evaluate if the spectrogram could provide detailed information on the visual characteristics that distinguish ADSD and MTD. SUBJECTS AND METHOD: 11 female patients of ADSD and 13 female patients of MTD who were diagnosed by laryngoscope and stroboscope from 2009 through 2012 were selected for this study. The speech samples of subjects were obtained using Computerized Speech Lab. The two speech therapists evaluated a wide-band (300 Hz) spectrogram by blind test using 4 scales (0-3 point) for four spectral findings. RESULTS: Abrupt voice breaks and irregular wide-spaced vertical striations of ADSD were significantly higher than those of MTD. Well-defined formants and high-frequency spectral noise were not found significantly different between two groups. CONCLUSION: The spectrograms provided visual perceptual information needed to differentiate ADSD from MTD. Voice therapy to reduce hypertension could be considered for patients of ADSD with excessive formants and noise. If spectrogram analysis were used along with other assessments, it would be more useful in distinguishing ADSD from MTD.

Determination of ginsenoside compound K in human plasma by liquid chromatography-tandem mass spectrometry of lithium adducts

Ginsenoside compound K (GCK), the main metabolite of protopanaxadiol constituents of Panax ginseng, easily produces alkali metal adduct ions during mass spectrometry particularly with lithium. Accordingly, we have developed a rapid and sensitive liquid chromatography-tandem mass spectrometric method for analysis of GCK in human plasma based on formation of a lithium adduct. The analyte and paclitaxel (internal standard) were extracted from 50 µL human plasma using methyl tert-butyl ether. Chromatographic separation was performed on a Phenomenex Gemini C18 column (50 mm×2.0 mm; 5 μm) using stepwise gradient elution with acetonitrile-water and 0.2 mmol/L lithium carbonate at a flow rate of 0.5 mL/min. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions at m/z 629→449 for the GCK-lithium adduct and m/z 860→292 for the adduct of paclitaxel. The assay was linear in the concentration range 1.00-1000 ng/mL (r (2)>0.9988) with intra- and inter-day precision of ±8.4% and accuracy in the range of -4.8% to 6.5%. Recovery, stability and matrix effects were all satisfactory. The method was successfully applied to a pharmacokinetic study involving administration of a single GCK 50 mg tablet to healthy Chinese volunteers.

Rapid Determination of N-Methylcarbamoyl Adduct in Hemoglobin of Workers Exposed to N,N-Dimethylformamide by Ultra High Performance Liquid Chromatography-Mass Spectrometry / 分析化学

A rapid analytical method was developed for the determination of N-methylcarbamoyl adduct in Hemoglobin of workers exposed to N,N-dimethylformamide by ultra high performance liquid chromatography-mass spectrometry ( UPLC/MS/MS). About 0. 1 g of hemoglobin sample, 40 μmol/L of 3-methyl-5-isopropylhydantoin (MIH) as the internal standard and 4. 75 mL of HCl-acetic acid (2∶1, V/V) were added in the centrifuge tube, and mixed for 3 min. Then the tube was heated in boiling water bath for 1h. After cooling down, 200 μL of the mixture and 600 μL of formic acid-acetonitrile (1%) were added into 96-well extract plate. The vacuum pump pressure was controlled to make the sample collection elute within 2-4 min.The purified collection was transferred into the sample vial, and 3-methyl-5-isopropylhydantoin ( MVH ) as degration product of N-methylcarbamoyl adduct was quantified by UPLC/MS/MS in multiple reaction monitoring ( MRM ) by internal standard method. A good linear relationship was obtained in the MVH concentration range of 0 . 01-1 . 0 μmol/L with the correlation coefficient of 0 . 999 . The recovery of added MVH in the blank sample was 97 . 3% and the relative standard deviation was 1 . 7%. The limit of detection (LOD) was 0. 01 μmol/g. This method was proved to be fast and efficient.

Biotransformation of a cage-like diels-alder adduct and derivatives by Mucor ramosissimus samutsevitsch / Biotransformação de um aduto de diels-alder cage-like e derivados por Mucor ramosissimus samutsevitsch

The present study aimed to evaluate the ability for biotransformation of the Diels-Alder adduct tricyclo[6.2.1.0(2,7)]undeca-4,9-dien-3,6-dione (1) and two synthetic derivatives by the saprobe fungus Mucor ramosissimus Samutsevitsch. Products from oxidation, isomerization and, regioselective and enantioselective reduction were achieved.

Neste trabalho avaliou-se a capacidade de biotransformação do aduto de Diels-Alder triciclo[6.2.1.0(2-7)]undeca-4,9-dien-3,6-diona (1) e dois derivados sintéticos pelo fungo sapróbio Mucor ramosissimus Samutsevitsch. Produtos de oxidação, isomerização e redução regiosseletiva e enantiosseletiva foram obtidos.

Estudio teóricoddel efecto isotópico de hidrógeno en el aducto borano-carbonilo / Theoretical study of the hydrogen isotope effect on the borane-carbonile adduct / Estudo teorico do efeito isotopico de hidrogeno no aducto borano-carbonilo

Se estudió el efecto de la sustitución isotópica de hidrógeno sobre la geometría, la estructura electrónica y la estabilidad del aducto borano-carbonilo, mediante el método de orbitales moleculares nucleares y electrónicos (OMNE) implementado en el paquete computacional APMO. Se encontró que el aumento de la masa isotópica acorta las distancias de enlace boro-isótopo y carbono-oxígeno, mientras que alarga la distancia boro-carbono. Se determinó además la estabilidad del aducto a partir de las energías de formación y las distancias de enlace B-C. Se encontró que el aumento de la masa isotópica debilita el enlace B-C. Una primera explicación de este fenómeno en términos del concepto de acidez de Lewis predijo resultados contrarios a los encontrados, mientras que un modelo de reactividad basado en las diferencias de las energías de los orbitales LUMO del borano permitió dar cuenta de este efecto.

We have investigated the hydrogen isotope effect on the geometry, the electronic structure and the stability of the borane-carbonile adduct, by using the nuclear-electronic molecular orbital method (NEMO) which has been implemented in the APMO software. We have found that an increase of the mass of the hydrogen isotope reduces the boron-hydrogen and carbon-oxygen bond lengths while increasing the boron-carbon distance. In this study, the stability of the adduct has been analyzed in terms of formation energies and B-C bond distances. We have found that the increase of the isotope mass weakens the B-C bond. We tried to give an explaination to this phenomenon based on Lewis acidity concept but it predicted the wrong results. A reactivity model based on the energy differences of borane LUMO orbitais offered a correct explaination to this effect.

Temos estudado o efeito da substituição de isótopos de hidrogénio sobre a geometria, estrutura electrónica e da estabilidade do aduto Borana-carbonil, através do mêtodo de orbitais moleculares-core versões (OMNE) implementado no pacote computacional APMO. Descobrimos que um aumento da isótopo massa encurta as distâncias de ligação boro-carbono-isotópica de oxigênio e aumenta a distância, enquanto boro-carbono. Foi ainda determinada a estabilidade do aduto de as energias de formação e distâncias de ligação BC. Nós descobrimos que o aumento da massa isotópica minar a relação BC. Uma explicação para este fenômeno em termos de conceito de acidez de Lewis predita resultados contrários aos encontrados enquanto um modelo baseado em diferenças de reatividade nas energias dos orbitais LUMO do Borana autorizados a conta para este efeito.

Suppression of lipid-hydroperoxide and DNA-adduct formation by isoflavone-containing soy hypocotyl tea in rats

<p><b>OBJECTIVE</b>Phytoestrogen isoflavones (IFs) are considered to suppress estrogen-related cancers through their antiestrogenic activity. The antioxidant effect of IFs, however, has not been confirmed in anin vivo system, so suppression of hydroperoxide formation and resultant DNA adduct formation were studied.</p><p><b>METHODS</b>The antioxidant effects of the soya-hypocotyl tea (SHT), which contained daidzein (14+/-1.5 mg/l) and genistein (3+/-0.5 mg/l), were examined in Wistar rats fed the AIN-76 control diet or iron deficient diet (FeD) for 4 weeks. The intake amount of the diet and IFs were measured daily. Urinary excretion of IFs was measured for 3 days before sacrifice. In addition to the serum lipid analyses, phosphatidylcholine hydroperoxide (PCOOH), and phosphatidylethanolamine hydroperoxide (PEOOH) production in red blood cells and the liver were measured as a biomarker of oxidants. Production of DNA adducts by oxidative stress was measured by the amount of 8-hydroxy-2'-deoxyguanosine (oh(8)dG) in the liver and kidney, and urine. Histological changes were checked by H&E staining and immunohistochemistry for oh(8)dG.</p><p><b>RESULTS</b>FeD rats showed anemia, growth retardation, hyperlipidemia. IFs only lowered the triacylglycerol level and did not change the cholesterol level. Rats fed the normal diet did not show suppression of PCOOH and PEOOH production in either red blood cells or the liver, while groups administered SHT showed suppressed production of PCOOH and PEOOH in the liver. The cumulative intake of daidzein, genistein and the total amount of IFs showed significant inverse associations with urinary excretion of oh(8)dG. oh(8)dG in the kidney showed an inverse association with the amount of oh(8)dG in the urine. Enzymehistochemically, a strong localization of oh(8)dG was found in the epithelial cells of the bile canaliculi and proximal tubules of the kidney.</p><p><b>CONCLUSION</b>IFs and SHT showed antioxidant effects at physiological concentrations in anin vivo system. The antioxidant effects of IFs decreased oxidation stress to the nuclear DNA, which was shown by the decreased oh(8)dG production. It is suggested that to prevent various cancers, in addition to the known antiestrogenie, antityrosin kinase, and other effects. IFs appeared to promote excretion of oh(8)dG.</p>

Suppression of Lipid-Hydroperoxide and DNA-Adduct Formation by Isoflavone-Containing Soy Hypocotyl Tea in Rats

Objective: Phytoestrogen isoflavones (IFs) are considered to suppress estrogen-related cancers through their antiestrogenic activity. The antioxidant effect of IFs, however, has not been confirmed in an in vivo system, so suppression of hydroperoxide formation and resultant DNA adduct formation were studied.Metheds: The antioxidant effects of the soya-hypocotyl tea (SHT), which contained daidzein (14+/−1.5 mg/l) and genistein (3+/−0.5 mg/l), were examined in Wistar rats fed the AIN-76 control diet or iron deficient diet (FeD) for 4 weeks. The intake amount of the diet and IFs were measured daily. Urinary excretion of IFs was measured for 3 days before sacrifice. In addition to the serum lipid analyses, phosphatidylcholine hydroperoxide (PCOOH), and phosphatidylethanolamine hydroperoxide (PEOOH) production in red blood cells and the liver were measured as a biomarker of oxidants. Production of DNA adducts by oxidative stress was measured by the amount of 8-hydroxy-2’-deoxyguanosine (oh8dG) in the liver and kidney, and urine. Histological changes were checked by H&E staining and immunohistochemistry for oh8dG.Results: FeD rats showed anemia, growth retardation, hyperlipidemia. IFs only lowered the triacylglycerol level and did not change the cholesterol level. Rats fed the normal diet did not show suppression of PCOOH and PEOOH production in either red blood cells or the liver, while groups administered SHT showed suppressed production of PCOOH and PEOOH in the liver. The cumulative intake of daidzein, genistein and the total amount of IFs showed significant inverse associations with urinary excretion of oh8dG. oh8dG in the kidney showed an inverse association with the amount of oh 8dG in the urine. Enzyme-histochemically, a strong localization of oh8dG was found in the epithelial cells of the bile canaliculi and proximal tubules of the kidney.Conclusion: IFs and SHT showed antioxidant effects at physiological concentrations in an in vivo system. The antioxidant effects of IFs decreased oxidation stress to the nuclear DNA, which was shown by the decreased oh8dG production. It is suggested that to prevent various cancers, in addition to the known antiestrogenic, antityrosin kinase, and other effects. IFs appeared to promote excretion of oh8dG.

The Application of Biological Monitoring and Effects of Ethanol and Phenobarbital on Plasma Protein Adducts Formed in Rats Exposed to Benzidine / 대한산업의학회지

OBJECTIVES: The effects of ethanol and phenobarbital,which are known to affect metabolism of xenobiotics, on the formation of benzidine-and its metabolites-plasma protein adducts in rats administered benzidine were evaluated. METHODS: The experimental rats were divided into the control,ethanol and phenobar-bital groups. The experimental groups (ethanol and phenobarbital group)were pretreated with ethanol (1g/kg)or phenobarbital (80mg/kg)24 hours prior to the oral administration of benzidine (0.5mmol/kg). Blood samples were obtained from the vena cava from 5 rats in each group; and at 30 min,3 h,6 h,9 h,12 h,24 h,48 h,72 h,96 h,and 144 h after the administration of benzidine using heparin treated syringes.The plasma protein levels were separated immediately after taking blood samples. The adducts were underwent basic hydrolysis to convert them into aromatic amines. The hydrolyzed benzidine, monoacetylbenzidine, and 4-aminobiphenyl were analyzed by reverse-phased liquid chro-matography with an electrochemical detector. The quantitative amount of the metabolites was expressed by the plasma protein binding index(PBI). RESULTS: Similar to the hemoglobin adducts,the levels of the plasma protein adducts of the ethanol and phenobarbital groups (benzidine-, monoacetylbenzidine-, and 4-amino-biphenyl-PBI)were higher than those of the control group. These results are attributable to the fact that ethanol and phenobarbital induced to the plasma protein adduct formation. The N-acetylation ratio in the control group was highest at 72 h with 2.34.In the ethanol group,it was highest at 72 h with a ratio of 2.46 and was highest in the phenobarbital group at 72 h with a ratio of 2.43. The N-acetylation ratio of the plasma protein adducts was relatively lower than that of the hemoglobin adducts.The level of the plasma protein adduct increased more rapidly than the hemoglobin adducts in all experimental groups regardless of the pretreatment,and decreased rapidly after reaching the maximum level. CONCLUSION: The above results indicate that ethanol and phenobarbital increased the level of plasma protein adduct formation. The plasma protein adducts tended to decrease more rapidly than the hemoglobin adducts in the body after benzidine exposure. This results in this study result suggests that the effects of ethanol or phenobarbital need to be considered in the biochemical monitoring,and that the level of the plasma protein adducts be a more proper biomarker than the hemoglobin adducts for assessing the short term exposure to a benzidine and benzidine based dye.

Molecular biomarkers of occupational lung cancer

Occupational exposures to certain metals, hydrocarbons and ionizing radiation are associated with increased lung cancer in workers; because these exposures continue, lung cancer remains an important problem in industrialized nations. The gravity of the lung cancer, specifically the low cure rate associated with the disease, has forced researchers to focus efforts at developing biological indicators (biomarkers) of carcinogen exposure and early, reversible effects. This review examines critically the development of these biomarkers for occupational and environmenta exposures to polycyclic aromatic hydrocarbons (PAH), a ubiquitous class of lung carcinogens. Biomarkers of several different stages of the carcinogenic process have been proposed. Industrial hygiene and occupational health emphasize exposure and disease prevention. For this reason, biomarkers useful in industrial hygiene practice are those which measure events prior to the initiation phase of carcinogenesis; markers of later events which have a greater positive predictive value may measure irreversible effects and are more appropriate for disease screening and epidemiology. One of the strengths of biological monitoring is that exposures and effects can be measured regardless of route. Data indicates that the dermal route may be a significant pathway for delivery of PAH to the lung. This finding has important ramifications because as airborne exposure limits decrease the relative impact of dermal absorption is increased.