ASIC1a involves the acid-mediated activation of pancreatic stellate cells associated with autophagy induction

The acidic tumor microenvironment (TME) of pancreatic cancer affects the physiological function of pancreatic stellate cells (PSCs), which in turn promotes cancer progression. Acid-sensing ion channel 1a (ASIC1a) is responsible for acidosis-related physiopathological processes. In this study, we investigated the effect of acid exposure on the activation and autophagy of PSCs, and the role of ASIC1a in these events. The results showed that acidic medium upregulated the expression of ASIC1a, induced PSCs activation and autophagy, which can be suppressed by inhibiting ASIC1a using PcTx1 or ASIC1a knockdown, suggesting that ASIC1a involves these two processes. In addition, the acid-induced activation of PSCs was impaired after the application of autophagy inhibitor alone or in combination with ASIC1a siRNA, meaning a connection between autophagy and activation. Collectively, our study provides evidence for the involvement of ASIC1a in the acid-caused PSCs activation, which may be associated with autophagy induction.

Global disease burden of COPD from 1990 to 2019 and prediction of future disease burden trend in China

OBJECTIVES

This study aimed to assess and predict the disease burden attributable to chronic obstructive pulmonary disease (COPD) in a timely, comprehensive, and reliable manner, thereby mitigating the health hazards of COPD.

STUDY DESIGN AND METHODS

Data on the disease burden owing to COPD from 1990 to 2019 were extracted from the Global Burden of Disease (GBD) Study 2019. Linear regression analysis was used to calculate the estimated annual percentage change (EAPC) in the age-standardized rates. Non-parametric tests were used for subgroup analysis. The Bayesian age-period-cohot (BAPC) model integrated nested Laplace approximations to predict the disease burden over the next 25 years. Sensitivity analysis was performed using the Norpred APC model.

RESULTS

Globally, the COPD-related age-standardized incidence rate decreased from 216.48/100,000 in 1990 to 200.49/100,000 in 2019, with an EAPC of -0.33. But the number of new cases increased from 8,722,966 in 1990 to 16, 214, 828 in 2019. Trends in prevalence, deaths, and disability-adjusted life years (DALYs) were the same as incidence. There were significant differences in disease burden between the genders and all age groups (P < 0.05) in China. The projections suggested that the COPD-related number of new cases and deaths in China would increase by approximately 1.5 times over the next 25 years.

CONCLUSIONS

The number of incidence, prevalence, deaths, and DALYs had all increased in China in the past and would continue to grow over the next 25 years. Therefore, measures should be taken to target risk factors and high-risk groups.

A non-coding cancer mutation disrupting an HNF4α binding motif affects an enhancer regulating genes associated to the progression of liver cancer

BACKGROUND

Somatic mutations in coding regions of the genome may result in non-functional proteins that can lead to cancer or other diseases, however cancer mutations in the non-coding regions have rarely been studied and the interpretation of their effects is difficult. Non-coding mutations might act by breaking or creating transcription factor binding motifs in promoters, enhancers or silencers resulting in altered expression of target gene(s). A high number of mutations have been reported in coding and non-coding regions in cells of liver cancer. Hepatocyte nuclear factor 4α is a transcription factor that regulates the expression of several genes in liver cells, while the motifs it binds are frequently mutated in promoters and enhancers in liver cancer.

AIM

The aim of the study is to evaluate the genetic effects of a non-coding somatic mutation frequently observed in liver cancer.

MATERIALS AND METHODS

We evaluated experimentally the effects of a somatic mutation frequently reported in liver cancer as a motif-breaker for the binding of hepatocyte nuclear factor 4α. The effects of the mutation on protein binding and enhancer activity were studied in HepG2 cells via electrophoresis mobility shift assay and dual luciferase reporter assays. We also studied genome-wide promoter-enhancer interactions performing targeted chromosome conformation capture in liver tissue to identify putative target genes whose expression could be altered by the mutation.

RESULTS

We found that the mutation leads to reduced protein binding and a decrease in enhancer activity. The enhancer harboring the mutation interacts with the promoters of ANAPC13, MAP6D1 and MUC13, which have been implicated in liver cancer.

CONCLUSIONS

The study highlights the importance of non-coding somatic mutations, vastly understudied, but likely to contribute to cancer development and progression.

[Difficulties and countermeasures for the perioperative management of megasplenectomy in patients with advanced schistosomiasis]

The etiology, pathology, clinical features and prognosis of megalosplenic advanced schistosomiasis have their specific features, and therefore, the perioperative management of this disorder has special countermeasures. The review analyzes the difficult problems in the perioperative management of megalosplenic advanced schistosomiasis, including ultra - low platelet counts, extensive and severe adhesive splenomegaly, massive hemorrhage during surgery and portal vein thrombosis, and proposes countermeasures to tackle these problems, with aims to guide the clinical treatment and cure of schistosomiasis, thereby improving the prognosis, reducing complications and improving the quality of life.

Transgenic characterization of two silkworm tissue-specific promoters in the haemocyte plasmatocyte cells

Haemocytes play crucial roles in insect metabolism, metamorphosis, and innate immunity. As a model of lepidopteran insects, the silkworm is a useful model to study the functions of both haematopoiesis and haemocytes. Tissue-specific promoters are excellent tools for genetic manipulation and are widely used in fundamental biological research. Herein, two haemocyte-specific genes, Integrin β2 and Integrin β3, were confirmed. Promoter activities of Integrin β2 and Integrin β3 were evaluated by genetic manipulation. Quantitative real-time PCR and western blotting suggested that both promoters can drive enhanced green fluorescent protein (EGFP) specifically expressed in haemocytes. Further evidence clearly demonstrated that the transgenic silkworm exhibited a high level of EGFP signal in plasmatocytes, but not in other detected haemocyte types. Moreover, EGFP fluorescence signals were observed in the haematopoietic organ of both transgenic strains. Thus, two promoters that enable plasmatocytes to express genes of interest were confirmed in our study. It is expected that the results of this study will facilitate advances in our understanding of insect haematopoiesis and immunity in the silkworm, Bombyx mori.

Melatonin at pharmacological concentrations suppresses osteoclastogenesis via the attenuation of intracellular ROS

Osteoporosis is linked to age-related decline of melatonin production; however, the direct effects of melatonin on osteoclastogenesis remain unknown. Our study demonstrates that melatonin at pharmacological concentrations, rather than at physiological concentrations, significantly inhibits osteoclastogenesis. Melatonin-mediated anti-osteoclastogenesis involves a reactive oxygen species (ROS)-mediated but not a silent information regulator type 1 (SIRT1)-independent pathway.

INTRODUCTION

Osteoporosis is a bone disorder linked to impaired bone formation and excessive bone resorption. Melatonin has been suggested to treat osteoporosis due to its beneficial actions on osteoblast differentiation. However, the direct effects of melatonin on osteoclastogenesis in bone marrow monocytes (BMMs) remain unknown. This study was to investigate whether melatonin at either physiological or pharmacological concentrations could affect osteoclast differentiation.

METHODS

Primary BMMs were isolated from the femurs and tibias of C57BL/6 mice and were induced toward multinucleated osteoclasts, in the presence of melatonin at either physiological (0.01 to 10 nM) or pharmacological (1 to 100 μM) concentrations. Tartrate-resistant acid phosphatase (TRAP) staining was used to label multinucleated osteoclasts and the levels of osteoclast-specific genes were evaluated. To further explore the underlying mechanisms, the roles of silent information regulator type 1 (SIRT1) and reactive oxygen species (ROS) were evaluated.

RESULTS

We found that melatonin at pharmacological concentrations, rather than at physiological concentrations, significantly inhibited osteoclast formation in a dose-dependent manner. The number of TRAP-positive cells and the gene expression of osteoclast-specific markers were significantly downregulated in melatonin-treated BMMs. The melatonin-mediated repression of osteoclast differentiation involved the inhibition of the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. The treatment with SIRT1 inhibitors did not affect osteoclast differentiation but, when supplemented with exogenous hydrogen peroxide, a partial rescue of melatonin-suppressed osteoclastogenesis was observed.

CONCLUSION

Melatonin at pharmacological doses directly inhibited osteoclastogenesis of BMMs by a ROS-mediated but not a SIRT1-independent pathway.

[Analysis of gene mutation of early onset epileptic spasm with unknown reason]

Objective: To summarize the gene mutation of early onset epileptic spasm with unknown reason. Method: In this prospective study, data of patients with early onset epileptic spasm with unknown reason were collected from neurological department of Children's Hospital of Fudan University between March 2016 and December 2016. Patients with known disorders such as infection, metabolic, structural, immunological problems and known genetic mutations were excluded. Patients with genetic disease that can be diagnosed by clinical manifestations and phenotypic characteristics were also excluded. Genetic research methods included nervous system panel containing 1 427 epilepsy genes, whole exome sequencing (WES), analysis of copy number variation (CNV) and karyotype analysis of chromosome. The basic information, phenotypes, genetic results and the antiepileptic treatment of patients were analyzed. Result: Nine of the 17 cases with early onset epileptic spasm were boys and eight were girls. Patients' age at first seizure onset ranged from 1 day after birth to 8 months (median age of 3 months). The first hospital visit age ranged from 1 month to 2 years (median age of 4.5 months). The time of following-up ranged from 8 months to 3 years and 10 months. All the 17 patients had early onset epileptic spasm. Video electroencephalogram was used to monitor the spasm seizure. Five patients had Ohtahara syndrome, 10 had West syndrome, two had unclear classification. In 17 cases, 10 of them had detected pathogenic genes. Nine cases had point mutations, involving SCN2A, ARX, UNC80, KCNQ2, and GABRB3. Except one case of mutations in GABRB3 gene have been reported, all the other cases had new mutations. One patient had deletion mutation in CDKL5 gene. One CNV case had 6q 22.31 5.5MB repeats. Ten cases out of 17 were using 2-3 antiepileptic drugs (AEDs) and the drugs had no effect. Seven cases used adrenocorticotropic hormone (ACTH) and prednisone besides AEDs (a total course for 8 weeks). Among them, five cases had no effect and two cases were seizure free recently. A case with GABRB3 (C.905A>G) had seizure controlled for 3 mouths. A case with ARX (C.700G>A) had seizure controlled for 6 mouths. Conclusion: The early onset epileptic spasm with unknown reason is highly related to genetic disorders. A variety of genetic mutations, especially new mutations were found. Genetic heterogeneity of epileptic spasm is obvious.

PRAME promotes in vitro leukemia cells death by regulating S100A4/p53 signaling

OBJECTIVE

PRAME (Preferentially Expressed Antigen in Melanoma) is a tumor-associated antigen recognized by immunocytes, and it induces cytotoxic T cell-mediated responses in melanoma. PRAME is expressed in a wide variety of tumors, but in contrast with most other tumor-associated antigens, it is also expressed in leukemias. The physiologic role of PRAME remains elusive. Recently, it has found PRAME could be involved in the regulation of cell death in leukemias, but the mechanism of the function is unclear. Here, we confirm that PRAME induces leukemias cell death by regulation of S100A4/p53 signaling.

MATERIALS AND METHODS

The pCDNA3-PRAME plasmid and its control were transfected with the KG-1 cells. The pCDNA3-PRAME transfected KG-1 cells were then transiently transfected with S100A4 cDNA or wt-p53 siRNA. The PRAME siRNA and its control were transfected with the K562 cells. The PRAME siRNA transfected K562 cells were then transiently transfected with S100A4 siRNA or pGMp53-Lu. PRAME, S100A4 and P53 were detected by Western blot assay in different time point. Annexin V/propidium iodide and MTT methods were used to detect apoptosis and cell survival rate.

RESULTS

KG-1 cells overexpressing the PRAME gene significantly induces apoptosis and decreases proliferation in vitro, followed by down-regulation of S100A4 and up-regulation of p53. Up-regulation of S100A4 by S100A4 transfection inhibits PRAME-induced p53 up-regulation. Furthermore, up-regulation of S100A4 by S100A4 transfection or down-regulation of p53 by p53 siRNA transfection reduces apoptosis and increases proliferation in vitro. Knockdown of PRAME in K562 cells significantly increases proliferation in vitro, followed by up-regulation of S100A4 and down-regulation of p53. The downregulation of S100A4 by S100A4 siRNA transfection increased p53 expression. Furthermore, downregulation of S100A4 by S100A4 siRNA transfection or up-regulation of p53 by p53 transfection decreases proliferation in vitro.

CONCLUSIONS

Our results suggest that the leukemias expressing high levels of PRAME has a favorable prognosis. PRAME promotes in vitro leukemia cells death by regulating S100A4/p53 signaling.

Reduced Penetrance of PRRT2 Mutation in a Chinese Family With Infantile Convulsion and Choreoathetosis Syndrome

Paroxysmal kinesigenic dyskinesia is a rare episodic movement disorder that can be isolated or associated with benign infantile seizures as part of choreoathetosis syndrome. Mutations in the PRRT2 gene have been recently identified as a cause of paroxysmal kinesigenic dyskinesia and infantile convulsion and choreoathetosis (ICCA). We reported a PRRT2 heterozygous mutation (c.604-607delTCAC, p.S202Hfs*25) in a 3-generation Chinese family with infantile convulsion and choreoathetosis and paroxysmal kinesigenic dyskinesia. The mutation was present in 5 family members, of which 4 were clinically affected and 1 was an obligate carrier with reduced penetrance of PRRT2. The affected carriers of this mutation presented with a similar type of infantile convulsion during early childhood and developed additional paroxysmal kinesigenic dyskinesia symptoms later in life. In addition, they all had a dramatic clinical response to oxcarbazepine/phenytoin therapy. Reduced penetrance of the PRRT2 mutation in this family could warrant genetic counseling.

Identification and characterisation of tobacco microRNA transcriptome using high-throughput sequencing

MicroRNAs (miRNAs) are post-transcriptional regulators that are involved in numerous biological processes in plants. In this study, we investigate miRNAs in Honghua Dajinyuan, an agronomically important species of tobacco in China. Here, we report a comprehensive analysis of miRNA expression profiles in the leaf, stem and root using a high-throughput sequencing approach. A total of 165 miRNAs, representing 55 conserved families, and 50 novel miRNAs, representing 19 families, were identified in three libraries. In addition, 12 miRNAs were randomly selected from a differentially expressed conserved miRNA family in three libraries with expression alterations and subjected to qRT-PCR validation. Of these, the expression level of nta-miR167d is highly enriched in the leaf tissue. In addition, the expression level of nta-miR319a is prominently enriched in the stem, while nta-miR160c is highly enriched in the root. Moreover, the target prediction showed that most of the targets coded for transcription factors that are involved in cellular and metabolic processes. GO analysis showed that most of the targets were involved in organelle function, served binding functions, and take part in cellular and metabolic processes. This study helps shed new light on understanding the role of miRNAs in different parts of the tobacco plant and adds a significant number of novel miRNAs to the tobacco miRNA transcriptome.

Prevalence and awareness of diabetes mellitus among a rural population in China: results from Liaoning Province

AIM

To clarify the diabetes prevalence trends among the rural population in northern China.

METHODS

All eligible permanent residents aged ≥ 35 years in selected rural villages of Liaoning province were invited to participate in the study. A total of 11 600 people completed all questionnaires and were included in the study. The response rate was 85.3%. Fasting plasma glucose levels were measured after at least 12 h of fasting and diabetes was diagnosed according to WHO criteria, i.e. fasting plasma glucose ≥ 7 mmol/l and/or being on treatment for diabetes. Impaired fasting glucose was defined according to the 1997 and the 2010 American Diabetes Association (ADA) criteria (6.1-6.9 and 5.6-6.9 mmol/l, respectively). Previous diagnoses of diabetes were assessed on the basis of self-reports.

RESULTS

The prevalence of diabetes among adults in the rural population was 10.6% (10.0% in men and 11.1% in women). The prevalence of impaired fasting glucose was 13.0 and 36.1% according to the 1997 and the 2010 ADA criteria, respectively. The prevalence of previously diagnosed diabetes was 4.3% among the whole population (3.3% in men and 5.1% in women). The prevalence of previously diagnosed diabetes was 34.8% in men and 50.2% in women. Only 29.6% of men and 42% of women with diabetes had taken oral hypoglycaemic agents or insulin to lower their blood sugar. In multivariate analysis, age, drinking habits, BMI, dyslipidaemia and family history of diabetes were identified as independent risk factors for diabetes, and occupational physical activity, smoking and lean meat intake were identified as independent protective factors for diabetes.

CONCLUSIONS

The prevalence of diabetes and impaired fasting glucose were found to be high in this rural population. Although the rate of treatment of people with diabetes has increased, the glycaemic control rate was still at a low level.

Long-term self-renewal of human pluripotent stem cells on peptide-decorated poly(OEGMA-co-HEMA) brushes under fully defined conditions

Realization of the full potential of human induced pluripotent stem cells (hiPSC) in clinical applications requires the development of well-defined culture conditions for their long-term growth and directed differentiation. This paper describes a novel fully defined synthetic peptide-decorated substrate that supports self-renewal of hiPSC in commercially available xeno-free, chemically defined medium. The Au surface was deposited by a poly(OEGMA-co-HEMA) film, using the surface-initiated polymerization method (SIP) with the further step of carboxylation. The hiPSC generated from umbilical cord mesenchymal cells were successfully cultured for 10 passages on the peptide-tethered poly(OEGMA-co-HEMA) brushes for the first time. Cells maintained their characteristic morphology, proliferation and expressed high levels of markers of pluripotency, similar to the cells cultured on Matrigel™. Moreover, the cell adhesion could be tuned by the pattern and peptide concentration on the substrate. This well-defined, xeno-free and safe substrate, which supports long-term proliferation and self-renewal of hiPSC, will not only help to accelerate the translational perspectives of hiPSC, but also provide a platform to elucidate the underlying molecular mechanisms that regulate stem cell proliferation and differentiation via SIP technology.

Stabilization by hydrophobic protection as a molecular mechanism for organic carbon sequestration in maize-amended rice paddy soils

The hydrophobic components of soil organic matter (SOM) are reckoned to play an important role in the stabilization of soil organic carbon (SOC). The contribution of hydrophobic substances to SOC sequestration was evaluated in four different paddy soils in the South of China, following a 6-month incubation experiment with maize straw amendments. Soil samples included: a well developed paddy soil (TP) derived from clayey lacustrine deposits in the Tai Lake plain of Jiangsu; an acid clayey paddy soil (RP) derived from red earth in the rolling red soil area of Jiangxi; a weakly developed neutral paddy soil (PP) formed on Jurassic purple shale from Chongq; and a calcic Fluvisol (MS) derived from riverine sediments from a wetland along the Yangtze valley of Anhui, China. The SOC molecular composition after 30 and 180 days of incubation, was determined by off-line thermochemolysis followed by gas chromatography-mass spectrometry analysis. Lignin, lipids and carbohydrates were the predominant thermochemolysis products released from the treated soils. A selective preservation of hydrophobic OM, including lignin and lipids, was shown in maize amended soils with prolonged incubation. The decomposition of lignin and lipids was significantly slower in the TP and RP soils characterized by a larger content of extractable iron oxyhydrates (Fed) and lower pH. The overall increase in hydrophobic substances in maize incubated samples was correlated, positively, with total content of clay and Fed, and, negatively, with soil pH. Moreover, yields of both lignin and lipid components showed a significant relationship with SOC increase after incubation. These findings showed that the larger the lipid and lignin content of SOM, the greater was the stability of SOC, thereby suggesting that OM hydrophobic components may have an essential role in controlling the processes of OC sequestration in paddy soils of South China.

Microbial degradation of microcystin-LR by Ralstonia solanacearum

A bacterial strain was isolated from Lake Dianchi (China) and its degradability and degradative pathways of the cyanobacterial toxin microcystin-LR (MC-LR) were studied. On the basis of morphological, physiological and biochemical tests, the strain was identified as Ralstonia solanacearum. The acute oral toxicity tests showed that Ralstonia solanacearum belongs to a non-toxic class. This bacterium degraded MC-LR at the rate of 9.4 mg/L per day, which was higher than those of the other bacterial strains reported in the literature. As for the degradative pathways, the results showed that the Adda-Arg peptide bond of MC-LR was initially hydrolysed by Ralstonia solanacearum to form a linear molecule as an intermediate. The intermediate product subsequently underwent a cyclisation reaction via dehydration to form a final product with a small peptide ring at one end of the molecule. These biodegradative pathways were different from those reported with other bacterial strains, suggesting that MC-LR may undergo different transformations, and different products were formed due to different compositions of bacteria present in natural lakes and reservoirs. These results suggest that there is a significant potential for Ralstonia solanacearum as a degrader for MC-LR removal from wastewater.

Surface modification of Ti-6Al-4V alloy for biomineralization and specific biological response: Part I, inorganic modification

Titanium and its alloys represent the gold standard for orthopaedic and dental prosthetic devices, because of their good mechanical properties and biocompatibility. Recent research has been focused on surface treatments designed to promote their rapid osteointegration also in case of poor bone quality. A new surface treatment has been investigated in this research work, in order to improve tissue integration of titanium based implants. The surface treatment is able to induce a bioactive behaviour, without the introduction of a coating, and preserving mechanical properties of Ti6Al4V substrates (fatigue resistance). The application of the proposed technique results in a complex surface topography, characterized by the combination of a micro-roughness and a nanotexture, which can be coupled with the conventional macro-roughness induced by blasting. Modified metallic surfaces are rich in hydroxyls groups: this feature is extremely important for inorganic bioactivity (in vitro and in vivo apatite precipitation) and also for further functionalization procedures (grafting of biomolecules). Modified Ti6Al4V induced hydroxyapatite precipitation after 15 days soaking in simulated body fluid (SBF). The process was optimised in order to not induce cracks or damages on the surface. The surface oxide layer presents high scratch resistance.

EURADOS coordinated action on research, quality assurance and training of internal dose assessments

EURADOS working group on 'Internal Dosimetry (WG7)' represents a frame to develop activities in the field of internal exposures as coordinated actions on quality assurance (QA), research and training. The main tasks to carry out are the update of the IDEAS Guidelines as a reference document for the internal dosimetry community, the implementation and QA of new ICRP biokinetic models, the assessment of uncertainties related to internal dosimetry models and their application, the development of physiology-based models for biokinetics of radionuclides, stable isotope studies, biokinetic modelling of diethylene triamine pentaacetic acid decorporation therapy and Monte-Carlo applications to in vivo assessment of intakes. The working group is entirely supported by EURADOS; links are established with institutions such as IAEA, US Transuranium and Uranium Registries (USA) and CEA (France) for joint collaboration actions.

BP neural network classification for bleeding detection in wireless capsule endoscopy

Bleeding in the digestive tract is one of the most common gastrointestinal tract (GI) diseases, as well as the complication of some fatal diseases. Wireless capsule endoscopy (WCE) allows physicians to noninvasively examine the entire GI tract. However it is very laborious and time-consuming to inspect large numbers of WCE images, which limits the wider application of WCE. It is therefore important to develop an automatic and intelligent computer-aided bleeding detection technique. In this paper, a new method aimed at bleeding detection in WCE images is proposed. Colour texture features distinguishing the bleeding regions from non-bleeding regions are extracted in RGB and HSI colour spaces; then a neural network using the colour texture features as the feature vector inputs is designed to recognize the bleeding regions. The experiments demonstrate that the bleeding regions can be correctly recognized and clearly marked out. The sensitivity of the algorithm is 93% and the specificity is 96%.

Structural and functional characterization of a pollen-specific promoter NTPp13 in tobacco

A novel 407 bp nucleotide sequence NTPp13 was isolated from tobacco (Nicotiana tabacum L.) by PCR, its structure and function were characterized. The NTPp13 sequence was highly homologous with the pollen-specific expression promoter Zm13 from maize (Zea mays L.) and contained some key motifs which controlled pollen-specific expression. The NTPp13 was fused to the beta-glucuronidase (GUS) reporter gene and transferred into tobacco. Analysis of the transgenic plants revealed that this putative promoter fragment was sufficient to direct GUS expression specifically in the anther, exactly in the pollen and pollen tube, and that GUS activity reached the maximum at the stage of pollen grain began to separate. Further study showed that the expression of NTPp13 sequence at pollen was stable at the range of temperature measured. These data suggested that the NTPp13 sequence was likely the essential element of promoter region of an unknown pollen-specific gene from tobacco.

The role of Zn in the interplay among Langmuir–Blodgett multilayer and myelin basic protein: a quantitative analysis of XANES spectra

We have performed a quantitative analysis of the X-ray absorption near-edge structure (XANES) spectra at the Zinc K-edge of systems formed by phospholipid Langmuir-Blodgett multilayers (LBMLs) in the presence and in the absence of myelin basic protein (MBP) and in two hydration conditions. These spectra have been analysed by a new procedure called Minuit XANes (MXAN) which is able to perform a quantitative fit of XANES data in terms of structural parameters. By this method, we have been able to correlate the relevant differences between the spectra observed in the XANES range with the coordination changes due to reduction of the space around the Zinc when the level of hydration is lowered and/or the myelin basic protein is added. These spectral differences are peculiar of the XANES energy range, and are not present in the extended X-ray absorption fine structure (EXAFS) energy range where the analysis was previously performed. With this investigation, we give an unambiguous answer to the question of the role of zinc in such complexes by showing that the metal interacts with both the phospholipid heads of the substrate and the myelin basic protein.

Leukocyte 8-hydroxydeoxyguanosine and aromatic DNA adduct in coke-oven workers with polycyclic aromatic hydrocarbon exposure

OBJECTIVE

To investigate the potential for exposure to polycyclic aromatic hydrocarbons (PAHs) to induce oxidative DNA damage, we conducted a cross-sectional study in coke-oven workers employed at an iron-steel factory.

METHODS

The study population contained 119 coke-oven workers from different work areas of the oven and 38 controls. Personal information on age, employment duration, smoking habit and alcohol consumption was obtained at an interview. Leukocyte 8-hydroxydeoxyguanosine (8-OHdG) was measured by high performance liquid chromatography with electrochemical detection. Leukocyte aromatic DNA adducts as effective dose, and urinary 1-hydroxypyren as internal dose, were also measured, and used to analyze the relationship of 8-OHdG with other biomarkers for PAH exposure, tobacco smoke and alcohol consumption.

RESULTS

The leukocyte 8-OHdG revealed a wide inter-individual variation. The highest 8-OHdG level was detected in bottom-workers of the coke-oven. There were significant differences among the four different work areas ( P=0.02). We could not find significant correlation between 8-OHdG levels and urinary 1-hydroxypyrene, but a weakly positive correlation was found between 8-OHdG and leukocyte aromatic DNA adducts among all subjects (r=0.19 P=0.03). We could not observe any effect of smoking and alcohol drinking on 8-OHdG production.

CONCLUSION

We could not find clear evidence that PAH exposure induces oxidative DNA damage.

The solid-solution partitioning of heavy metals (Cu, Zn, Cd, Pb) in upland soils of England and Wales

Ninety-eight surface soils were sampled from the uplands of England and Wales, and analysed for loss-on-ignition (LOI), and total and dissolved base cations, Al, Fe, and trace heavy metals (Cu, Zn, Cd, Pb). The samples covered wide ranges of pH (3.4-8.3) and LOI (9-98%). Soil metal contents measured by extraction with 0.43 mol l-1 HNO3 and 0.1 mol l-1 EDTA were very similar, and generally lower than values obtained by extraction with a mixture of concentrated nitric and perchloric acids. Total heavy metal concentrations in soil solution depend positively upon soil metal content and [DOC], and negatively upon pH and LOI, values of r2 ranging from 0.39 (Cu) to 0.81 (Pb). Stronger correlations (r2=0.76-0.95) were obtained by multiple regression analysis involving free metal ion (Cu2+, Zn2+, Cd2+, Pb2+) concentrations calculated with the equilibrium speciation model WHAM/Model VI. The free metal ion concentrations depend positively upon MHNO3 and negatively upon pH and LOI. The data were also analysed by using WHAM/Model VI to describe solid-solution interactions as well as solution speciation; this involved calibrating each soil sample by adjusting the content of "active" humic matter to match the observed soil pH. The calibrated model provided fair predictions of total heavy metal concentrations in soil solution, and predicted free metal ion concentrations were in reasonable agreement with the values obtained from solution-only speciation calculations.

Characterization of pyridine nucleotide coenzymes in the hyperthermophilic archaeon Pyrococcus furiosus

Pyridine-type nucleotides were identified in cell-free extracts of the hyperthermophilic archaeon Pyrococcus furiosus by their ability to replace authentic nicotinamide adenine dinucleotide (phosphate) [NAD(P)] in assays using pure P. furiosus enzymes. The nucleotides were purified using a combination of ion-exchange and reverse-phase chromatography. They were identified as NAD and NADP by analyses using liquid chromatography-mass spectrometry and high performance liquid chromatography. Their intracellular concentrations were measured in P. furiosus grown using maltose and peptides as the carbon sources. The concentrations decreased during the lag phase but remained constant during the exponential phase at approximately 0.17 and 0.13 mM, respectively. The amount of NAD was significantly lower (more than four-fold lower) than that in mesophilic bacteria, although the NADP concentration was comparable. The internal concentrations of NADH and NADPH in P. furiosus were determined to be 0.14 mM and 0.04 mM, respectively. The overall cellular concentration of NAD(P)(H) in P. furiosus (0.48 mM) is about half the value in the mesophiles. The NAD(H)/NADP(H) ratio in P. furiosus is consistent with the preferred use of NADP by several catabolic enzymes that have been purified from this organism. The mechanisms by which hyperthermophiles stabilize these thermally labile nicotinamide nucleotides are not known.

Forced expression of murine IL-17E induces growth retardation, jaundice, a Th2-biased response, and multiorgan inflammation in mice

IL-17 is a proinflammatory cytokine, and its in vivo expression induces neutrophilia in mice. IL-17E is a recently described member of an emerging family of IL-17-related cytokines. IL-17E has been shown to bind IL-17Rh1, a protein distantly related to the IL-17R, suggesting that IL-17E probably possesses unique biological functions. In this study, we have identified the murine ortholog of IL-17E and developed transgenic mice to characterize its actions in vivo. Biological consequences of overexpression of murine (m)IL-17E, both unique to IL-17E and similar to IL-17, were revealed. Exposure to mIL-17E resulted in a Th2-biased response, characterized by eosinophilia, increased serum IgE and IgG1, and a Th2 cytokine profile including elevated serum levels of IL-13 and IL-5 and elevated gene expression of IL-4, IL-5, IL-10, and IL-13 was observed in many tissues. Increased gene expression of IFN-gamma in several tissues and elevated serum TNF-alpha were also noted. In addition, IL-17E induces G-CSF production in vitro and mIL-17E-transgenic mice had increased serum G-CSF and exhibit neutrophilia, a property shared by IL-17. Moreover, exposure to mIL-17E elicited pathological changes in multiple tissues, particularly liver, heart, and lungs, characterized by mixed inflammatory cell infiltration, epithelial hyperplasia, and hypertrophy. Taken together, these findings suggest that IL-17E is a unique pleiotropic cytokine and may be an important mediator of inflammatory and immune responses.

[An epidemiologic study of bowel habit in adult non-patient population in Beijing area]

OBJECTIVE

To determine the bowel habit and its influencing factors in the adult non-patient population in Beijing area.

METHODS

A questionnaire survey was conducted among 2486 adult permanent residents in Beijing area by randomized stratified sampling. The bowel habit (defecation frequency, characters of feces, time of defecation, and abnormal defecation) of the 1 952 non-patients among them were further investigated. The non-patient subject should fulfil the following criteria: (1) without gastrointestinal and hepatic organic diseases; (2) without metabolic disease affecting the motility of the gastrointestinal tract, such as diabetes mellitus and thyroid hyperfunction; (3) without irritable bowel syndrome which fits in the Manning criteria; and (4) considering oneself as having normal bowel habits.

RESULTS

84.17% of the non-patient interviewees defecated once per day with the mean defecation frequency of 7.09 times per week. 89.86% of the interviewees had formed or soft stool. 93.08% of the non-patients defecated formed or soft stool 3 to 21 times per week. No evidence showed that the frequency of defecation and character of feces were related to age and sex. 77% of them defecated in the morning. The prevalence rates of constipation, diarrhea, and abdominal pain associated with defecation were 3.74%, 1.08%, and 7.38% respectively.

CONCLUSION

The defecation frequency of adult nonpatient population in Beijing area is almost identical to that reported in the west. 93.08% of the non-patient subjects have normal defecation patterns. It is necessary to define the judgement criteria for constipation and diarrhea for Chinese based on their defecation patterns.

Urinary 1-hydroxypyrene in coke oven workers relative to exposure, alcohol consumption, and metabolic enzymes

OBJECTIVES

To investigate the influence of personal lifestyle--such as smoking and alcohol consumption-on urinary 1-hydroxypyrene (1-OHP) concentrations in coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs) and to evaluate the association of 1-OHP concentrations with the genetic polymorphism of several metabolic enzymes including cytochrome P-450 (CYP) 1A1 and glutathione S-tranferases (GSTs).

METHODS

The study population contained 162 coke oven workers and 58 controls employed at the largest iron and steel factory in China. Personal data were collected at the interview. 1-OHP in urine was measured with high performance liquid chromatography with fluorescence detection. Genetic polymorphisms were identified by the polymerase chain reaction (PCR) method.

RESULTS

A positive association between excretion of urinary 1-OHP and the levels of exposure to PAHs was confirmed. Those people who consumed >or=50 g/day ethanol had significantly higher 1-OHP excretion than did other coke oven workers (p<0.01). No significant difference in urinary 1-OHP was found between smokers and non-smokers, in both controls and exposed subjects. The variant homozygotes at exon 7 of the CYP1A1 gene had significantly higher urinary 1-OHP concentrations than other CYP1A1 genotypes among the exposed workers (p=0.03). There was less association between the concentrations of 1-OHP and the GSTM1, GSTP1, or GSTT1 polymorphism.

CONCLUSIONS

The present study confirmed that urinary 1-OHP is a good biomarker for exposure to PAHs. Alcohol consumption affected urinary 1-OHP excretion. The variant genotypes of the CYP1A1 gene may result in the enhancement of PAH metabolites. It is helpful to understand the role of individual susceptibility on metabolism of carcinogens. These findings suggest that the modulating effect of individual lifestyle factors or genetic nature should be considered in future studies on occupational exposure to PAHs and in evaluating the health risk from harmful chemicals.

Perspectives on the biology of uncoupling protein (UCP) homologues

In mammals, it is believed that a portion of tissue metabolic rate is driven by counteraction of uncoupling, in which the energetically inefficient process of proton leak acts to diminish the mitochondrial electrochemical membrane potential. It is proposed that specific proteins associated with the mitochondrion catalyse uncoupling, and the biology of such putative uncoupling proteins (UCPs) is the subject of active research efforts. UCP4 and UCP5 are interesting in light of their abundant expression in the brain, which may signal an important metabolic function in thermogenesis or regulation of reactive oxygen species in that tissue. While each is expressed to various degrees outside of the brain, their impact on whole-animal metabolism remains to be clarified further. Transgenic mice expressing murine UCP5(L), the long isoform of UCP5, using an inducible metallothionine promoter (to drive expression of the transgene in liver, testis, heart, lung, spleen, intestine, kidney and brain) did not display any overt metabolic phenotype, despite liver UCP5(L) mRNA expression equivalent to that of normal mouse brain. This highlights the need for further studies to examine the nature of UCP5 physiology. Evidence for uncoupling behaviour has recently emerged from studies of the human 2-oxoglutarate carrier (OGC), indicating that the possibility of physiological proton leak elicited by the OGC and other mitochondrial carriers warrants further experimental evaluation.

Two unusual oleanane saponins from Anemone anhuiensis

From the rhizomes of Anemone anhuiensis (Ranunculaceae), two new triterpene saponins, anhuienosides A (1) and B (2), were isolated. These compounds are glycosylated at C-23 and their structures were elucidated as hederagenin 23-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside (1) and 23-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl hederagenin 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl ester (2) on the basis of chemical and spectral evidence.

Isolation and purification of the ovulation-inducing factor from seminal plasma in the bactrian camel (Camelus bactrianus)

The purpose of this study was to extract, identify and partially characterize a newly found ovulation-inducing factor, and thus gain our understanding of induced ovulation in biology. In our preliminary research, an ovulation-inducing factor (OIF) was isolated and purified from seminal plasma of the bactrian camel by ion-exchange chromatography on DEAE-cellulose, HPLC and reverse-phase HPLC. The OIF is a peptide with 74 residues and GnRH-like bioactivity, which is heat-stable in camel seminal plasma because the OIF is wrapped up in several protein layers with different properties. However, purified OIF is degraded when it is exposed to oxygen or is heated in water. According to the analysis of amino acid components and partial amino acid sequence aminated N-terminus, and its molecular weight, the OIF is completely different from the native-LHRH, LH, HCG, PMSG and PGF-2alpha. The OIF is a novel ovulation hormone in the bactrian camel, but is similar to that reported in the bull.

Amphibole fibres in Chinese chrysotile asbestos

Ten chrysotile bulk samples originating from six Chinese chrysotile mines were studied for amphibole fibres. Five of the mines operate on ultramafic rocks whereas one exploits a dolomite-hosted deposit. The asbestos fibre content in lung tissue was examined from seven deceased workers of the Shenyang asbestos plant using these raw materials. The bulk samples were pretreated with acid/alkali-digestion, and thereafter, scanning and transmission electron microscopy, X-ray microanalysis, selected area electron diffraction and X-ray powder diffractometry were used to identify the minerals. Sample preparation of lung tissue involved drying and low-temperature ashing. All of the bulk samples contained amphibole fibres as an impurity. The amphibole asbestos contents were between 0.002 and 0.310 w-%. Tremolite fibres were detected in every sample but anthophyllite fibres were present only in the sample originating from the dolomite-hosted deposit. In comparison, anthophyllite (71%), tremolite (9%) and chrysotile (10%) were the main fibre types in the lung tissue samples indicating faster pulmonary clearance of chrysotile fibres. The total levels ranged from 2.4 to 148.3 million fibres (over 1 microm in length) per gram of dry tissue, and they were consistent with heavy occupational exposure to asbestos.

U7C beamline and XAFS station of national synchrotron radiation laboratory

The XAFS station on beamline U7C of National Synchrotron Radiation Laboratory (NSRL) was completely constructed in December 1998. The source for XAFS station is from a 3-pole superconducting wiggler with magnetic field of 6 T inserted in the straight section of the storage ring. Using a Si(111) double crystal monochromator with a fixed slit, the X-ray intensity at the sample position is about 3x10(9) photons/second at the energy of 8980 eV of Cu K-edge. The Keithley 65 17 electrometers are used to record the electron charges that are produced in the ionization chambers. A high ratio of signal to noise has been obtained for the XAFS spectra of Cu, Ni and Fe foils. Furthermore, the XAFS spectrum of Cu foil in NSRL is in good agreement with that obtained in BSRF and KEK.

Overexpression of the human 2-oxoglutarate carrier lowers mitochondrial membrane potential in HEK-293 cells: contrast with the unique cold-induced mitochondrial carrier CGI-69

Using differential mRNA expression analysis, a previously uncharacterized gene was found to be up-regulated 2-fold in brown adipose tissue (BAT) of mice exposed to cold (4 degrees C) for 48 h. Contig and homology analysis revealed that the gene represents the murine orthologue to a sequence from a public database encoding a putative human protein (CGI-69). The presence of mitochondrial carrier domains in the human protein, its transmembrane topology and cold-induction of the mouse CGI-69 gene in BAT prompted an analysis of the idea that CGI-69 may represent a new uncoupling protein (UCP) functional homologue. However, transfection of human CGI-69 isoforms in HEK-293 cells yielded no change in mitochondrial membrane potential (Deltapsi(m)), despite localization of FLAG-tagged CGI-69 to mitochondria of MCF7 cells. Surprisingly, overexpression of the human 2-oxoglutarate carrier (OGC) protein (originally designed as a negative control) sparked a significant drop in Deltapsi(m), possibly signalling a previously unappreciated uncoupling activity for the OGC.

IL-1H, an interleukin 1-related protein that binds IL-18 receptor/IL-1Rrp

IL-18, or IGIF (interferon-gamma inducing factor), is an IL-1-related, pro-inflammatory cytokine, which plays a pivotal role in systemic and local inflammation. We have identified and characterized IL-1H, a novel IL-1-related molecule. IL-1H appears to be expressed in most tissues with relatively high levels in testis, thymus and uterus. The IL-1H transcripts were stimulated by phorbol ester (PMA) in human cell lines (A431, THP-1 and KG-1) and peripheral blood mononuclear cells (HPBMC) and dendritic cells (NHDC). The protein sequence of IL-1H is mostly related to IL-1ra with a similarity of 36%. A short form of IL-1H was identified, and lacks a 40-amino acid segment in the amino-terminal region of the protein. When expressed in mammalian cells, two secreted polypeptides of IL-1H were identified: an uncleaved and a cleaved form starting with amino acid Val-46. Furthermore, IL-1H binds the IL-18 receptor, but not the IL-1 receptor. These findings suggest that IL-1H may be another ligand for the IL-18 receptor and a new player in the inflammatory and immune responses mediated by the IL-18/IL-18R axis.

[Effect of LAS on physico-chemical properties and microorganism activity in soil environment]

Using a well drained paddy soil and the derived soil under vegetables in the Taihu Lake region, China, experiments of soil capillary rise, colloid dispersion and adsorption of toxic organics and heavy metals by soil under various degrees of LAS addition were conducted. Also incubation experiments of microorganism activity in soil with added LAS in different concentrations were carried out in laboratory. LAS addition resulted in lower capillary rise of soil solution, higher dispersion of soil colloids and lower capacity of soil for organic pollutants but no significant influence on adsorption of heavy metal cations. The nitrification and amonification in soil were very sensitive to LAS stress while denitrification turned to be stimulated. LAS addition gave stronger growth of soil bacteria while decreased growth of fungus. Meanwhile, soil respiration was stimulated in the first week of incubation and compressed afterwards by LAS at concentration over 5 mg/kg. It seemed that some species of microorganisms were tolerant of LAS in the studied soils.

Key role for sulfur in peptide metabolism and in regulation of three hydrogenases in the hyperthermophilic archaeon Pyrococcus furiosus

The hyperthermophilic archaeon Pyrococcus furiosus grows optimally at 100 degrees C by the fermentation of peptides and carbohydrates. Growth of the organism was examined in media containing either maltose, peptides (hydrolyzed casein), or both as the carbon source(s), each with and without elemental sulfur (S(0)). Growth rates were highest on media containing peptides and S(0), with or without maltose. Growth did not occur on the peptide medium without S(0). S(0) had no effect on growth rates in the maltose medium in the absence of peptides. Phenylacetate production rates (from phenylalanine fermentation) from cells grown in the peptide medium containing S(0) with or without maltose were the same, suggesting that S(0) is required for peptide utilization. The activities of 14 of 21 enzymes involved in or related to the fermentation pathways of P. furiosus were shown to be regulated under the five different growth conditions studied. The presence of S(0) in the growth media resulted in decreases in specific activities of two cytoplasmic hydrogenases (I and II) and of a membrane-bound hydrogenase, each by an order of magnitude. The primary S(0)-reducing enzyme in this organism and the mechanism of the S(0) dependence of peptide metabolism are not known. This study provides the first evidence for a highly regulated fermentation-based metabolism in P. furiosus and a significant regulatory role for elemental sulfur or its metabolites.

Evaluation of antineutrophil cytoplasmic antibody seroconversion induced by minocycline, sulfasalazine, or penicillamine

OBJECTIVE

Case reports have suggested that minocycline, sulfasalazine, and penicillamine are associated with antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. This study evaluated ANCA seroconversion due to these agents in serum samples prospectively collected in randomized, double-blind, controlled trials.

METHODS

The sources of study sera were 3 clinical trials: 1) a 48-week trial of minocycline for early rheumatoid arthritis, with 64 patients receiving minocycline compared with 68 receiving placebo; 2) a 37-week trial of sulfasalazine for rheumatoid arthritis, with 51 receiving sulfasalazine compared with 38 receiving placebo; and 3) a 104-week trial of penicillamine for early systemic sclerosis, with 15 undergoing high-dose penicillamine treatment versus 12 receiving low-dose penicillamine. ANCA were measured in the baseline and study-end serum samples by indirect immunofluorescence (IIF) for perinuclear ANCA (pANCA) and cytoplasmic ANCA (cANCA) patterns, and by antigen-specific enzyme-linked immunosorbent assay (ELISA) for antibodies to myeloperoxidase (anti-MPO) and proteinase 3 (anti-PR3). Laboratory personnel were blinded to the group identity of the samples. ANCA results were interpreted using an ANCA scoring system that combines the results of IIF and ELISA testing.

RESULTS

No patient in any of the active study drug groups demonstrated ANCA seroconversion according to the final interpretation of the combined IIF and ELISA results. Twelve of the 248 patients (5%) were positive for anti-MPO with pANCA at baseline. No subject was positive for anti-PR3 with cANCA. There were no findings suggestive of vasculitis in any of these patients.

CONCLUSION

From our study results, there was no suggestion of ANCA seroconversion induced by minocycline, sulfasalazine, or penicillamine. However, these findings do not rule out the possibility of rare, sporadic cases of either ANCA seroconversion or true drug-induced vasculitis with these drugs.

Characterization of novel UCP5/BMCP1 isoforms and differential regulation of UCP4 and UCP5 expression through dietary or temperature manipulation

Mitochondrial uncoupling proteins have been implicated in the maintenance of metabolic rate and adaptational thermoregulation. We recently reported the identification of a brain-specific mitochondrial uncoupling protein homologue, UCP4. Here we characterized another newly described member of the uncoupling protein family, termed UCP5 (also called BMCP1). UCP5 transcripts are present in multiple human and mouse tissues, with an especially high abundance in the brain and testis. Expression of UCP5 in mammalian cells reduces the mitochondrial membrane potential. Multiple isoforms of UCP5 were identified and exhibited tissue-specific distribution and different potency in reduction of membrane potential. Furthermore, the mRNA abundance of both UCP4 and UCP5 is modulated by nutritional status or temperature in a tissue-specific manner in mice. Brain UCP4 and UCP5 mRNA transcripts rose by 1.5- and 1.7-fold, respectively, and liver UCP5 expression increased by 1.8-fold in response to acute cold exposure. A high-fat diet increased UCP5 mRNA in liver by 1.6-fold selectively in the obesity-resistant A/J but not in the obesity-prone C57BL/6J mouse strain. Liver UCP5 expression decreased significantly with a 24 h fast and was restored to the normal level after refeeding. In contrast, brain transcripts for both genes were not significantly altered by fasting or high-fat diet. These findings are consistent with the notion that UCP4 and UCP5 may be involved in tissue-specific thermoregulation and metabolic changes associated with nutritional status.

Impact of endotoxin on UCP homolog mRNA abundance, thermoregulation, and mitochondrial proton leak kinetics

Linking tissue uncoupling protein (UCP) homolog abundance with functional metabolic outcomes and with expression of putative genetic regulators promises to better clarify UCP homolog physiological function. A murine endotoxemia model characterized by marked alterations in thermoregulation was employed to examine the association between heat production, UCP homolog expression, and mitochondrial proton leak ("uncoupling"). After intraperitoneal lipopolysaccharide (LPS, approximately 6 mg/kg) injection, colonic temperature (T(c)) in adult female C57BL6/J mice dropped to a nadir of approximately 30 degrees C by 8 h, preceded by a four- to fivefold drop in liver UCP2 and UCP5/brain mitochondrial carrier protein 1 mRNA levels, with no change in their hindlimb skeletal muscle (SKM) expression. SKM UCP3 mRNA rose fivefold during development of hypothermia and was correlated with an LPS-induced increase in plasma free fatty acid concentration. UCP2 and UCP5 transcripts recovered about three- to sixfold in both tissues starting at 6-8 h, preceding a recovery of T(c) between 16 and 24 h. SKM UCP3 followed an opposite pattern. Such results are not consistent with an important influence of UCP3 in driving heat production but do not preclude a role for UCP2 or UCP5 in this process. The transcription coactivator PGC-1 displayed a transient LPS-evoked rise (threefold) or drop (two- to fivefold) in SKM and liver expression, respectively. No differences between control and LPS-treated mouse liver or SKM in vitro mitochondrial proton leak were evident at time points corresponding to large differences in UCP homolog expression.

Aromatic DNA adducts in coke-oven workers, in relation to exposure, lifestyle and genetic polymorphism of metabolic enzymes

OBJECTIVE

This study investigates the effect of multiple factors, including exposure to polycyclic aromatic hydrocarbons (PAHs), lifestyle, genetic polymorphism of cytochrome P450 (CYP)1A1, glutathione transferase (GST)M1, GSTP1, N-acetyltransferase (NAT)2 and gene p53, as well as any family history of cancer, on DNA adduct levels in coke-oven workers.

METHODS

Sixty-five coke-oven workers employed at the largest iron-steel factory in China were recruited for the study. Personal data were collected at the interview. DNA adduct levels in total white blood cells (WBCs) were detected using 32P-postlabeling techniques. Genetic polymorphisms were analyzed by polymerase chain reaction (PCR) methods.

RESULTS

The subjects were divided into low and high exposure groups, according to personal exposure to PAHs. The mean adduct value was 1.57 (range 0.54 to 4.35) per 10(8) nucleotides. A tendency for increased levels of DNA adducts in the high exposure group was observed, compared with the low exposure group (P = 0.07). In the low exposure group, DNA adducts were found to be positively associated with urinary cotinine (r = 0.44, P = 0.01). The rare allele homozygotes of CYP1A1 showed significantly higher DNA adduct levels than those of other CYP1A1 genotypes. Individuals with the NAT2 wild type had significantly increased DNA adduct levels than those with other NAT2 genotypes in the high exposure group. The p53 genetic polymorphism revealed a significantly positive effect on DNA adducts formation. There was a significantly higher adduct level in the subjects with a family history of cancer than those without, in the high exposure category.

CONCLUSIONS

Effects of several variables, such as smoking, genetic polymorphism of 2 CYP1A1, NAT2, and gene p53, and a family history of cancer on DNA adduct levels were found, suggesting that these variables should be considered when evaluating the genotoxic effect of occupational exposure to PAHs using WBCs DNA adducts.

Increased death receptor 5 expression by chemotherapeutic agents in human gliomas causes synergistic cytotoxicity with tumor necrosis factor-related apoptosis-inducing ligand in vitro and in vivo

The intractability of malignant gliomas to multimodality treatments plays a large part in their extremely poor prognosis. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a novel member of the tumor necrosis factor (TNF) family that induces apoptosis preferentially in tumor cells through binding to its cognate death receptors, DR4 and DR5. Here we show that the DNA-damaging chemotherapeutic drugs, cis-diamminedichloroplatinum(II) (CDDP) and etoposide, elicited increased expression of DR5 in human glioma cells. Exposure of such cells in vitro to soluble human TRAIL in combination with CDDP or etoposide resulted in synergistic cell death that could be blocked by soluble TRAIL-neutralizing DR5-Fc or the caspase inhibitors, Z-Asp-CH2-DCB and CrmA. Moreover, systemic in vivo administration of TRAIL with CDDP synergistically suppressed both tumor formation and growth of established s.c. human glioblastoma xenografts in nude mice by inducing apoptosis without causing significant general toxicity. The combination treatment resulted in complete and durable remission in 29% of mice with the established s.c. xenografts and also significantly extended the survival of mice bearing intracerebral xenografts. These results provide preclinical proof-of-principle for a novel therapeutic strategy in which the death ligand, TRAIL, is safely combined with conventional DNA-damaging chemotherapy.