Association of the colistin resistance gene mcr-1 with faecal pollution in water environments in Hanoi, Vietnam

Colistin is one of the antibiotics of last resort for human health. However, the dissemination of the plasmid-mediated colistin resistance gene mcr-1 is of great concern globally. In the One Health framework, the environment is an important component for managing antimicrobial resistance. However, little information is available concerning the prevalence of mcr-1 in water environments. We aimed to reveal the prevalence of mcr-1 in different water environments in Hanoi, Vietnam. Quantitative PCR was applied to detect mcr-1 in four urban drainages receiving untreated domestic wastewater, three rivers, five lakes and two groundwater samples. Urban drainages contained higher concentrations of mcr-1, suggesting that urban residents carry the gene. The class 1 integron-integrase gene was identified as a good surrogate of antibiotic resistance genes including mcr-1. A significant correlation was found between the levels of mcr-1 and the human-specific cross-assembly phage, which is an indicator of human faecal pollution. These results indicated that the primary source of mcr-1 in urban water environments is human faeces, which is consistent with the fact that most domestic wastewater is untreated in Hanoi. The control of untreated wastewater is critical for alleviating the spread of mcr-1 in water environments in Vietnam.

Floquet-engineered quantum walks

The quantum walk is the quantum-mechanical analogue of the classical random walk, which offers an advanced tool for both simulating highly complex quantum systems and building quantum algorithms in a wide range of research areas. One prominent application is in computational models capable of performing any quantum computation, in which precisely controlled state transfer is required. It is, however, generally difficult to control the behavior of quantum walks due to stochastic processes. Here we unveil the walking mechanism based on its particle-wave duality and then present tailoring quantum walks using the walking mechanism (Floquet oscillations) under designed time-dependent coins, to manipulate the desired state on demand, as in universal quantum computation primitives. Our results open the path towards control of quantum walks.

Ozone disinfection kinetics of poliovirus 1 determined by cell culture assay, RT-qPCR and ethidium monoazide qPCR reduction in a continuous quench-flow reactor

AIMS

A continuous quench-flow (CQF) reactor was developed to collect samples at the reaction times of less than one second. The reactor is applied to determine ozone disinfection kinetics of poliovirus and to study whether EMA-qPCR can assess the viral infectivity after ozone disinfection.

METHODS

Ozone disinfection of poliovirus was conducted in the developed CQF, and the disinfection kinetics were tested in the range of 0·7-5·0 s at ozone concentration of 0·08 and 0·25 mg l^-1 . Inactivation, damage on viral genome and damage on capsid integrity were determined by plaque assay, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and ethidium monoazide treatment coupled with RT-qPCR (EMA-qPCR), respectively.

RESULTS

By using CQF, 2·18 and 2·76 log₁₀ reductions were observed at the reaction time of 0·7 s and ozone concentration of 0·08 and 0·25 mg l^-1 , respectively, followed by tailing. Ozone disinfection kinetics of poliovirus 1 were better fit by the efficiency factor Hom model than by the Chick-Watson model, or the modified Chick-Watson model. Kinetics observed were similar between RT-qPCR and EMA-qPCR assays at the reaction times of <2·0 s and ozone concentrations of 0·08 and 0·25 mg l^-1 . At reaction times > 5 s, viral concentration evaluated by EMA-qPCR was reduced in comparison to stable RT-qPCR results. Both assays still underestimated the virus inactivation.

CONCLUSION

The simple developed reactor can be used to investigate viral ozone disinfection kinetics and to elucidate inactivation characteristics or mechanisms at very short exposure times.

SIGNIFICANCE AND IMPACT OF THE STUDY

The developed CQF reactor is beneficial for better understanding of virus inactivation by ozone, and the reactor can be used to better elucidate disinfection kinetics and mechanisms for future research. This work constitutes an important contribution to the existing knowledge of the application and limitation of the EMA/PMA-qPCR to assess virus infectivity after ozone disinfection.

Combination gemcitabine plus S-1 versus gemcitabine plus cisplatin for advanced/recurrent biliary tract cancer: the FUGA-BT (JCOG1113) randomized phase III clinical trial

BACKGROUND

Gemcitabine plus cisplatin (GC) is the standard treatment of advanced biliary tract cancer (BTC); however, it causes nausea, vomiting, and anorexia, and requires hydration. Gemcitabine plus S-1 (GS) reportedly has equal to, or better, efficacy and an acceptable toxicity profile. We aimed to confirm the non-inferiority of GS to GC for patients with advanced/recurrent BTC in terms of overall survival (OS).

PATIENTS AND METHODS

We undertook a phase III randomized trial in 33 institutions in Japan. Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable BTC, an Eastern Cooperative Oncology Group Performance Status of 0 - 1, and adequate organ function. The calculated sample size was 350 with a one-sided α of 5%, a power of 80%, and non-inferiority margin hazard ratio (HR) of 1.155. The primary end point was OS, while the secondary end points included progression-free survival (PFS), response rate (RR), adverse events (AEs), and clinically significant AEs defined as grade ≥2 fatigue, anorexia, nausea, vomiting, oral mucositis, or diarrhea.

RESULTS

Between May 2013 and March 2016, 354 patients were enrolled. GS was found to be non-inferior to GC [median OS: 13.4 months with GC and 15.1 months with GS, HR, 0.945; 90% confidence interval (CI), 0.78-1.15; P = 0.046 for non-inferiority]. The median PFS was 5.8 months with GC and 6.8 months with GS (HR 0.86; 95% CI 0.70-1.07). The RR was 32.4% with GC and 29.8% with GS. Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm.

CONCLUSIONS

GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC.

CLINICAL TRIAL NUMBER

This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index.htm), number UMIN000010667.

The State Scientific Automated Medical Registry, Kazakhstan: an important resource for low-dose radiation health research

Direct quantitative assessment of health risks following exposure to ionizing radiation is based on findings from epidemiological studies. Populations affected by nuclear bomb testing are among those that allow such assessment. The population living around the former Soviet Union's Semipalatinsk nuclear test site is one of the largest human cohorts exposed to radiation from nuclear weapons tests. Following research that started in the 1960s, a registry that contains information on more than 300,000 individuals residing in the areas neighboring to the test site was established. Four nuclear weapons tests, conducted from 1949 to 1956, resulted in non-negligible radiation exposures to the public, corresponding up to approximately 300 mGy external dose. The registry contains relevant information about those who lived at the time of the testing as well as about their offspring, including biological material. An international group of scientists worked together within the research project SEMI-NUC funded by the European Union, and concluded that the registry provides a novel, mostly unexplored, and valuable resource for the assessment of the population risks associated with environmental radiation exposure. Suggestions for future studies and pathways on how to use the best dose assessment strategies have also been described in the project. Moreover, the registry could be used for research on other relevant public health topics.

Abstract P1-05-05: eEF1A2 facilitates PTEN-GSK3β mediated Aurora-A protein degradation during S-G2 phase inactivated in PTEN-deficient breast cancer

The AURKA gene, encoding Aurora kinase-A (Aurora-A), is frequently amplified and overexpressed across multiple cancer types correlating with poor prognosis. Although the AURKA gene is frequently amplified in human cancers, underlying mechanism(s) for Aurora-A protein stability through different phases of cell cycle are not well elucidated. Inhibiting the kinase activity and promoting protein degradation are two well-validated conceptual strategies for targeting protein kinases in cancers. Here, we demonstrate that Eukaryotic Elongation Factor 1 Alpha 2 (eEF1A2) facilitates PTEN-GSK3β mediated Aurora-A protein degradation through the SCF complex (SKP1-Cul1-FBXW7) during the S/G2 phase of proliferating cells. In contrast, this mechanism is inactivated in cancer cells accompanying PTEN-GSK3β pathway deficiency. Mechanistically, eEF1A2 interacts with Aurora-A, GSK3β, FBXW7 and Cul1-E3 ligase, as the SCF complex, to facilitate Aurora-A polyubiquitination for 26S proteasomal degradation. eEF1A2 promotes PTEN phosphorylation at T366 and stability, inactivates AKT and activates GSK3β which in turn phosphorylates Aurora-A at S283, S284 and S342. The phosphorylation of Aurora-A at S342 is detected during S/G2 phase of cell mitosis in parallel with eEF1A2-SCF complex formation with active form of GSK3β and neddylated Cul1. Conversely, genetic ablation of EEF1A2 and PTEN, activation of AKT, inhibition of GSK3β, expression of Aurora-A phosphodeficient-mutant attenuates the Aurora-A protein degradation which is corroborated in Aurora-A overexpressing mouse mammary carcinomas and human breast carcinomas. This study identifies a novel mechanism of Aurora-A protein degradation mediated eEF1A2-PTEN-GSK3β pathway and provides a framework for the discovery of Aurora-A therapeutic targets in breast cancer that harbors deficiency of PTEN tumor suppressor pathway.

Citation Format: Treekitkarnmongkol W, Solis LM, Kai K, Thompson AM, Tian W, Wistuba II, Sasai K, Jltsumori Y, Sahin AA, Hawke DH, Lee JM, Qin L, Bawa-Khalfe T, Rad R, Wong KK, Abbott CM, Katayama H, Sen S. eEF1A2 facilitates PTEN-GSK3β mediated Aurora-A protein degradation during S-G2 phase inactivated in PTEN-deficient breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-05-05.

[Drug-induced immune hemolytic anemia caused by cefmetazole]

A 56-year-old female who was diagnosed with acute calculous cholecystitis received intravenous administration of cefmetazole (CMZ) from the day of admission; she underwent laparoscopic cholecystectomy on the 13th hospital day. She was referred to our department because of hematuria that persisted for 3 days and progressive anemia on the day after the surgery. Laboratory data showed the following results: hemoglobin (Hb) level, 6.8 g/dl; reticulocyte count, 3.4%; serum lactate dehydrogenase, 1,505 IU/l; serum creatinine, 1.1 mg/dl; and undetectable haptoglobin. The direct globulin test showed that the patient was positive for IgG. Thus, drug-induced immune hemolytic anemia (DIIHA) was considered. All drugs, including CMZ, were immediately discontinued, and steroid was administered. The signs of hemolysis began to subside 3 days after the initiation of steroid therapy, and the administration of steroid was discontinued on the 5th day of the treatment. The patient's Hb level gradually increased, and the direct globulin test showed that the patient was negative for IgG on the 21st day from the onset of hematuria. Antibodies against CMZ-coated red blood cells were observed in the serum preserved at the onset of hemolysis. DIIHA is a rare but life-threatening disease. Immediate discontinuation of any suspected drugs and the initiation of steroid therapy as necessary are important in cases wherein DIIHA is suspected.

An Evaluation of Hemostatic Abnormalities in Patients With Hemophilia According to the Activated Partial Thromboplastin Time Waveform

The usefulness of the waveform of activated partial thromboplastin time (APTT) in various diseases has been evaluated in recent years. The APTT waveform was examined in patients with hemophilia and patients positive for lupus anticoagulant (LA). The correlation with the FVIII activity was highest for the height of acceleration peak. The peak time of acceleration, velocity, and ½ fibrin formation, and the width of acceleration and velocity were significantly long and the height of acceleration was significantly low in patients with hemophilia. The height of velocity was significantly low in patients with hemophilia with inhibitor. There were no significant differences in the APTT waveform between patients with hemophilia and patients with LA, but the peak of acceleration and ½ fibrin formation were significantly longer and the height of acceleration and velocity were significantly lower in patients with hemophilia with inhibitor than in the patients with LA. Wave changes in the APTT were observed in all 22 patients positive for LA, while a biphasic waveform was observed in patients with hemophilia with FVIII activity <10.0%. The APTT waveform is useful for the analysis of hemostatic abnormalities in patients with hemophilia.

[Successful long-term management of ovarian bleeding and menorrhagia with prothrombin complex concentrate in a patient with congenital factor X deficiency]

A female patient in her forties exhibited no evidence of abnormal bleeding at birth. At the age of 6 years, she experienced pain in bilateral thighs and knee joints without any occasion. Accordingly, the bleeding tendency was suspected, and the coagulation profile assessment revealed prolongation of the APTT (122 s). Further tests revealed a marked reduction in the factor X activity (FX:C) to 4.5%, and the patient was diagnosed with congenital factor X deficiency; at that time, the case was reported by Mori et al. (The Japanese Society of Hematology 43: 572-586, 1980). At the age of 19 years, she was transferred to our hospital, where both prolongation of the PT and APTT and reduction of FX:C to <1% were reconfirmed. During follow-up observation, the patient developed lower abdominal pain and severe anemia. Gynecological examination revealed ovarian bleeding with menorrhagia. Thus, she was prescribed low-dose pills for menorrhagia, which successfully arrested the progression of anemia for a long term. However, she underwent uterine myomectomy and developed anemia again because of menorrhagia. For controlling menorrhagia-caused severe anemia, we initiated the patient on FX replacement therapy with prothrombin complex concentrate, PPSB-HT "Nichiyaku," by self-infusion on day 1 of each monthly menstrual cycle. Since then, menorrhagia and severe anemia have remained under good control.

Abstract P1-08-09: Aurora kinase-A protein stability is negatively regulated by eEF1α2 and PTEN in breast cancer: Prognostic and therapeutic implications

Background: The AURKA gene encoding Aurora kinase-A (Aurora-A) protein is localized on chromosome 20q13 that is frequently amplified and overexpressed across multiple cancer types correlating with patient prognosis. Aurora-A plays a pivotal role in faithful segregation of chromosomes and normal progression of mitosis, peaking at G2/M followed by degradation at the end of mitosis by APC/C (Cdh1). However, regulation of Aurora-A protein stability in human cancer cells is not well elucidated. Here, we show that Aurora-A is targeted for ubiquitination and degradation by SCF complex involving eEF1α2 and PTEN in human breast cancer cells. Methods: Using a panel of breast cancer cell lines, as in vitro models, the eEF1α2 was knocked down or ectopically expressed to test the stability of Aurora-A protein. For in vivo models, tissue micro arrays of human breast cancer were immunostained for Aurora-A and eEF1α2 expression and categorized values were statistically tested by Chi-squared test. In addition, the public breast cancer dataset (Transbig) was used to predict breast cancer prognosis by Kaplan-Meier survival analysis. Results: In breast cancer cell lines and patient samples, an eEF1α2 non-expressing group showed a trend of higher Aurora-A expression than eEF1α2 expressing group, whose trend was significant in patient samples (P&lt;0.05). Knocking down of eEF1α2 enhanced Aurora-A protein stability. In contrast, ectopic expression of eEF1α2 dramatically decreased Aurora-A protein stability. Inhibition of proteasome activity by MG132 could restore the Aurora-A protein in eEF1α2 expressing cells. Biochemical assays showed the direct binding between eEF1α2 and Aurora-A, and eEF1α2 dependent ubiquitination of Aurora-A. Inverse correlation of the expression levels of the two proteins was also observed throug the cell cycle, with eEF1α2 levels being high from G1 through G2 phases while Aurora-A expression peaked from G2/M phase through cytokinesis. Taken together, these findings highlight eEF1α2 as a novel negative regulator destabilizing Aurora-A through ubiquitin-proteasome proteolytic pathway. Further, mechanistic studies revealed that eEF1α2 enhanced the interaction of SCF E3 ubiquitin ligase complex protein; FBXW7 and Cul1, with Aurora-A. In line with this scenario, knocking down of Cul1 increased Aurora-A level. Since PTEN loss was reported to stabilize Aurora-A through inhibiting SCF complex, we tested the significance of PTEN loss in our model. Knocking down of PTEN further stabilized Aurora-A suggesting an independent role of PTEN from eEF1α2 in destabilizing Aurora-A. When eEF1α2 expressing cells were treated with AKT inhibitor, Aurora-A was destabilized with enhanced bindings between Aurora-A and FBXW7/Cul1. Lastly, low PTEN expression correlated with poor prognosis of Aurora-A over expressing breast cancer patients (P&lt;0.01). Conclusions: Aurora-A overexpression in human breast cancer cells may be associated with loss of eEF1α2 and PTEN due to reduced interaction of SCF with Aurora-A. Findings indicate significant prognostic and therapeutic implications of altered expression of eEF1α2/PTEN/Aurora-A pathways among Aurora-A subset of breast cancer patients.

Citation Format: Treekitkarnmongkol W, Kai K, Katayama H, Tian W, Rodriguez-Canales J, Sahin AA, Sen S. Aurora kinase-A protein stability is negatively regulated by eEF1α2 and PTEN in breast cancer: Prognostic and therapeutic implications [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-08-09.

Endovascular Treatment of Vein of Galen Aneurysmal Malformations

We report two cases of vein of Galen aneurysmal dilatation (VGAD) and four cases of vein of Galen aneurysmal malformation (VGAM) with special reference to clinical features and therapeutic indications of endovascular treatment.

A case with VGAD was treated by radiosurgery in 1985 with no amelioration to the patient, A case of choroidal type VGAM underwent an operation in 1987, but died of massive hemorrhage 2 years later. The other case of VGAD has been followed-up conservatively.

The remaining cases of VGAM (two choroidal type and one mural type) were treated by endovascular treatment. The two cases of choroidal type were successfully embolized but died of systemic complications, and the only case of mural type was cured.

Capsid-Damaging Effects of UV Irradiation as Measured by Quantitative PCR Coupled with Ethidium Monoazide Treatment

The damage to a viral capsid after low-pressure (LP) and medium-pressure (MP) UV irradiation was assessed, using the quantitative or quantitative reverse transcription PCR coupled with ethidium monoazide treatment (EMA-PCR). After UV irradiation, adenovirus 5 (Ad5) and poliovirus 1 (PV1) were subjected to a plaque assay, PCR, and EMA-PCR to investigate the effect of UV irradiation on viral infectivity, genome damage, and capsid damage, respectively. The effectiveness of UV wavelengths in a viral genome and capsid damage of both PV1 and Ad5 was also further investigated using a band-pass filter. It was found that an MPUV lamp was more effective than an LPUV lamp in inactivating Ad5, whereas there was no difference in the case of PV1. The results of viral reduction determined by PCR and EMA-PCR indicated that MP UV irradiation damaged Ad5 capsid. The damage to PV1 and Ad5 capsid was also not observed after LP UV irradiation. The investigation of effects of UV wavelengths suggested that UV wavelengths at 230-245 nm have greater effects on adenovirus capsid in addition to viral genome than UV wavelengths beyond 245 nm.

Three dimensional structure of the anthrax toxin translocon-lethal factor complex by cryo-electron microscopy

We have visualized by cryo-electron microscopy (cryo-EM) the complex of the anthrax protective antigen (PA) translocon and the N-terminal domain of anthrax lethal factor (LF(N) inserted into a nanodisc model lipid bilayer. We have determined the structure of this complex at a nominal resolution of 16 Å by single-particle analysis and three-dimensional reconstruction. Consistent with our previous analysis of negatively stained unliganded PA, the translocon comprises a globular structure (cap) separated from the nanodisc bilayer by a narrow stalk that terminates in a transmembrane channel (incompletely distinguished in this reconstruction). The globular cap is larger than the unliganded PA pore, probably due to distortions introduced in the previous negatively stained structures. The cap exhibits larger, more distinct radial protrusions, previously identified with PA domain three, fitted by elements of the NMFF PA prepore crystal structure. The presence of LF(N), though not distinguished due to the seven-fold averaging used in the reconstruction, contributes to the distinct protrusions on the cap rim volume distal to the membrane. Furthermore, the lumen of the cap region is less resolved than the unliganded negatively stained PA, due to the low contrast obtained in our images of this specimen. Presence of the LF(N) extended helix and N terminal unstructured regions may also contribute to this additional internal density within the interior of the cap. Initial NMFF fitting of the cryoEM-defined PA pore cap region positions the Phe clamp region of the PA pore translocon directly above an internal vestibule, consistent with its role in toxin translocation.

Assembly of anthrax toxin pore: lethal-factor complexes into lipid nanodiscs

We have devised a procedure to incorporate the anthrax protective antigen (PA) pore complexed with the N-terminal domain of anthrax lethal factor (LFN ) into lipid nanodiscs and analyzed the resulting complexes by negative-stain electron microscopy. Insertion into nanodiscs was performed without relying on primary and secondary detergent screens. The preparations were relatively pure, and the percentage of PA pore inserted into nanodiscs on EM grids was high (∼43%). Three-dimensional analysis of negatively stained single particles revealed the LFN -PA nanodisc complex mirroring the previous unliganded PA pore nanodisc structure, but with additional protein density consistent with multiple bound LFN molecules on the PA cap region. The assembly procedure will facilitate collection of higher resolution cryo-EM LFN -PA nanodisc structures and use of advanced automated particle selection methods.

Abstract P2-04-05: Prolonged targeted overexpression of Aurora-A in mammary epithelium promotes mammary adenocarcinoma with genomic instability

Aurora kinase-A (referred to as Aurora-A) identified as a sereine/threonine kinase induces mitotic progression process including centrosome amplification, bipolar spindle formation and chromosome segregation through modulation of activity and localization of its interacting proteins during cell division. Beside its essential roles in mitosis, cancer profiling studies have revealed that Aurora-A function is implicated in tumor relevant signaling pathways and overexpressed in many human tumors. The findings showed highly frequent overexpression of Aurora-A in human breast ductal carcinoma in situ and primary invasive ductal breast carcinoma. Moreover, the Aurora-A overexpression correlates with poor prognosis in breast carcinoma, deregulated overexpression of Aurora-A associates with centrosome anomalies and chromosome instability in rodent models of mammary caricinogenesis.

However, published studies in several transgenic mouse models attempting to address the role of Aurora-A in tumorigenesis and genomic instability have raised conflicting results. In this report we targeted expression of Aurora-A transgene in an inducible mouse model in which expression of Aurora-A was restricted to mammary epithelium during multiple pregnancy and lactation cycles under the activity of β-lactoglobulin promotor. The results demonstrate that overexpression of Aurora-A could induce tumorigenesis in mouse mammary epithelium. The tumor incidence was 70% of Aurora-A transgenic mice at 16 months of age. Of note, overexpression of Aurora-A led to genomic instability. Comparative genomic hybridization (CGH) array analyses revealed loss of Trim12a, Trim12c, Trim30b, Trim30d, Trim30e, Cdkn2d, Pten, Cep55 and gain of Adam6. Notably, Aurora-A overexpression caused nuclear accumulation of cyclin D1, activation of AKT, overexpression of TPX2 and PLK1and loss of ERα expression in tumors. Our findings indicated that prolonged Aurora-A expression in mammary epithelium leads to mammary adenocarcinomas with genomic instability. Aurora-A driven adenocarcinoma reveals deregulation of critical tumor relevant genetic pathways involving both oncogenes and tumor suppressor genes. These transgenic mouse model findings indicate that Aurora-A may be an important therapeutic target for mammary cancer.

Keywords: Aurora-A, carcinogenesis.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-04-05.

Occurrence and reduction of human viruses, F-specific RNA coliphage genogroups and microbial indicators at a full-scale wastewater treatment plant in Japan

AIMS

To evaluate and compare the reductions of human viruses and F-specific coliphages in a full-scale wastewater treatment plant based on the quantitative PCR (qPCR) and plate count assays.

METHODS AND RESULTS

A total of 24 water samples were collected from four locations at the plant, and the relative abundance of human viruses and F-RNA phage genogroups were determined by qPCR. Of the 10 types of viruses tested, enteric adenoviruses were the most prevalent in both influent and effluent wastewater samples. Of the different treatment steps, the activated sludge process was most effective in reducing the microbial loads. Viruses and F-RNA phages showed variable reduction; among them, GI and GIII F-RNA phages showed the lowest and the highest reduction, respectively.

CONCLUSIONS

Ten types of viruses were present in wastewater that is discharged into public water bodies after treatment. The variability in reduction for the different virus types demonstrates that selection of adequate viral indicators is important for evaluating the efficacy of wastewater treatment and ensuring the water safety.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our comprehensive analyses of the occurrence and reduction of viruses and indicators can contribute to the future establishment of appropriate viral indicators to evaluate the efficacy of wastewater treatment.

RERF databases and implications for future studies

Many studies have been conducted by the Radiation Effects Research Foundation (RERF) to assess the radiation effects on human beings of atomic bombs, and numerous data have been collected, including records of medical examinations and questionnaires, analytical results, inventories of biosamples and published or unpublished documentation. Some of those data have been stored and analysed since the Atomic Bomb Casualty Commission (later reorganised as RERF) was established in 1947. RERF has made an effort to establish an archival database system so that an RERF researcher can access data at any time without difficulty. Under development is a new database system with the capability to handle a very large amount of data and permit future bioinformatics analyses of data, such as that required in genomics and proteomics analyses.

Molecular detection and genotyping of human noroviruses in influent and effluent water at a wastewater treatment plant in Japan

AIMS

To investigate the prevalence, seasonality and genotype distribution of human noroviruses (NoVs) in wastewater in Japan.

METHODS AND RESULTS

Influent and effluent water samples were collected monthly for a year from a wastewater treatment plant and examined for the presence of genogroups I and II (GI and GII) NoVs. Using real-time reverse transcription (RT)-PCR assays, 12 (100%) influent and six (50%) effluent samples were positive for both GI and GII NoV genomes, with a higher prevalence in winter. A total of 152 different NoV strains, comprising 84 GI and 68 GII strains, were identified using seminested RT-PCR assays followed by cloning and sequence analysis. These strains were classified into nine GI genotypes (GI/1, 2, 4, 5, 8, 9, 11, 12 and 14) and 13 GII genotypes (GII/1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15 and 16), showing considerable genetic diversity.

CONCLUSIONS

Based on the partial capsid gene sequences, we identified a great number of NoV strains belonging to many genotypes, demonstrating that genetically diverse NoV strains are co-circulating in aquatic environments and human populations.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results clearly demonstrate the seasonal trend and genetic diversity of NoVs in wastewater.

Dose-response time modelling for highly pathogenic avian influenza A (H5N1) virus infection

Aims:  To develop time‐dependent dose–response models for highly pathogenic avian influenza A (HPAI) of the H5N1 subtype virus.

Methods and Results:  A total of four candidate time‐dependent dose–response models were fitted to four survival data sets for animals (mice or ferrets) exposed to graded doses of HPAI H5N1 virus using the maximum‐likelihood estimation. A beta‐Poisson dose–response model with the N₅₀ parameter modified by an exponential‐inverse‐power time dependency or an exponential dose–response model with the k parameter modified by an exponential‐inverse time dependency provided a statistically adequate fit to the observed survival data.

Conclusions:  We have successfully developed the time‐dependent dose–response models to describe the mortality of animals exposed to an HPAI H5N1 virus. The developed model describes the mortality over time and represents observed experimental responses accurately.

Significance and Impact of the Study:  This is the first study describing time‐dependent dose–response models for HPAI H5N1 virus. The developed models will be a useful tool for estimating the mortality of HPAI H5N1 virus, which may depend on time postexposure, for the preparation of a future influenza pandemic caused by this lethal virus.

An integrated analysis of two phase II trials (JCOG0001 and JCOG0405) of preoperative chemotherapy followed by D3 gastrectomy for gastric cancer (GC) with extensive lymph node metastasis (ELM)

90

Background: GC with ELM (bulky N2 metastasis and / or para-aortic lymph node metastases [PAN]) is commonly regarded unresectable, while in JCOG combined modality treatment has been tested since 2000 (JCOG0001 and JCOG0405). Both trials met their primary endpoints (i.e., 3 year-survival of 27.3% in JCOG0001 and R0 resection of 82.4% in JCOG0405). The survival and the toxicity profile were quite different between the trials despite the similar eligibility with an outstanding 3-year survival of 58.8% in JCOG0405. This study is conducted to explore if survival is still better in JCOG0405 after adjusting baseline factors and if there is a subset of patients (pts) who benefit more from either treatment.

Methods: Eligibility criteria for both included histologically proven gastric adenocarcinoma; bulky nodal involvement around major branched arteries to the stomach and/or PAN; cM0 (except PAN); negative lavage cytology; not linitis plastica type; PS of 0 or 1. Pts received two or three cycles of induction chemotherapy of IP: irinotecan (70 mg/m2 on day 1 and day 15) and cisplatin (80 mg/m2 on day 1) in JCOG0001, or SP: S1 (80 mg/m2 from day 1 to 21) and cisplatin (60 mg/m2 on day 8) in JCOG0405, followed by D3 gastrectomy. Multivariate analysis for overall survival adjusting baseline factors and treatment (IP/SP) was performed with a Cox regression model. Interaction tests were also carried out between baseline factors and treatment.

Results: After adjusting baseline factors, SP was superior than IP for overall survival (HR=0.335: 0.184 – 0.612). There was only interaction effect between treatment and the status of lymph node metastases (bulkyN+/PAN- vs bulkyN-/PAN+ vs bulkyN+/PAN+; p=0.1306).

Conclusions: SP was shown to be the favorable treatment for GC with ELM by multivariate analysis, while poor prognosis in pts having both bulky N+ and PAN+ may necessitate further treatment improvement.

No significant financial relationships to disclose.

Development of a real-time RT-PCR assay combined with ethidium monoazide treatment for RNA viruses and its application to detect viral RNA after heat exposure

A method was developed for discriminating damaged viruses or naked viral RNA from intact viruses by ethidium monoazide (EMA) treatment before RT-PCR. The applied EMA treatment consisted of three steps: (1) EMA dose, (2) exposure to light, and (3) additional purification by spin-column gel filtration. Approximately 4-log reduction in viral RNA concentration was observed by adding a dose of 10 μg/mL-EMA with 300 s of light irradiation. Although residual EMA can be an inhibitor of RT-PCR, its effect was reduced by spin-column gel filtration or a QIAamp® Viral RNA Mini Kit. EMA-RT-PCR was applied to the thermally treated PV1. Results of EMA-RT-PCR were similar to the plaque assay when PV1 was thermally inactivated. Although this is a preliminary study investigating applicability of the EMA-RT-PCR method for RNA viruses, the results suggest that the method is potentially applicable for the selective detection of epidemiologically important enteric viruses in water such as enteroviruses and noroviruses.

Effect of photoreactivation on ultraviolet inactivation of Microcystis aeruginosa

Microcystis aeruginosa forms algal bloom in lakes. They produce toxic compounds such as microcystin. Against such algal problems, the effect of UV treatment was examined. In UV treatment, the effect of photoreactivation should be examined. Photoreactivation is a repair mechanism of genomic DNA damage by sunlight irradiation. UV treatment causes DNA damages on target cyanobacteria, however sunlight can repair some of these DNA damages. To examine the effect of photoreactivation, both white and yellow light incubations were employed. White light allows both photoreactivation and photosynthesis, while yellow light prohibits photoreactivation and only allows photosynthesis. Microcystis aeruginosa NIES 98 strain and PCC 7806 strain were used as the test cultures. Those cultures were exposed to low-pressure (LP) or medium-pressure (MP) ultraviolet (UV) lamp, then incubated under white or yellow light. Yellow light incubation method was effective to examine photoreactivation. It was revealed that almost six times UV fluence was required to inactivate 99% of Microcystis aeruginosa, under photoreactivation condition, compared with non-photoreactivation condition. Inhibition of photoreactivation could greatly enhance UV treatment efficiency against Microcystis aeruginosa. One of the practical suggestions is to conduct UV treatment at night, when photoreactivation by sunlight rarely takes place. Highly efficient inactivation was achieved by avoiding photoreactivation.