Continuous year-round isolation of giant viruses from brackish shoreline soils

Giant viruses, categorized under Nucleocytoviricota, are believed to exist ubiquitously in natural environments. However, comprehensive reports on isolated giant viruses remain scarce, with limited information available on unrecoverable strains, viral proliferation sites, and natural hosts. Previously, the author highlighted Pandoravirus hades, Pandoravirus persephone, and Mimivirus sp. styx, isolated from brackish water soil, as potential hotspots for giant virus multiplication. This study presents findings from nearly a year of monthly sampling within the same brackish water region after isolating the three aforementioned strains. This report details the recurrent isolation of a wide range of giant viruses. Each month, four soil samples were randomly collected from an approximately 5 × 10 m plot, comprising three soil samples and one water sample containing sediment from the riverbed. Acanthamoeba castellanii was used as a host for virus isolation. These efforts consistently yielded at least one viral species per month, culminating in a total of 55 giant virus isolates. The most frequently isolated species was Mimiviridae (24 isolates), followed by Marseilleviridae (23 isolates), Pandoravirus (6 isolates), and singular isolates of Pithovirus and Cedratvirus. Notably, viruses were not consistently isolated from any of the four samples every month, with certain sites yielding no viruses. Cluster analysis based on isolate numbers revealed that soil samples from May and water and sediment samples from January produced the highest number of viral strains. These findings underscore brackish coastal soil as a significant site for isolating numerous giant viruses, highlighting the non-uniform distribution along coastlines.

Post COVID-19 condition of the Omicron variant of SARS-CoV-2

Objectives

To investigate the prevalence of post coronavirus disease (COVID-19) condition of the Omicron variant in comparison to other strains.

Study design

A single-center cross-sectional study.

Methods

Patients who recovered from Omicron COVID-19 infection (Omicron group) were interviewed via telephone, and patients infected with other strains (control group) were surveyed via a self-reporting questionnaire. Data on patients’ characteristics, information regarding the acute-phase COVID-19, as well as presence and duration of COVID-19-related symptoms were obtained. Post COVID-19 condition in this study was defined as a symptom that lasted for at least 2 months, within 3 months of COVID-19 onset. We investigated and compared the prevalence of post COVID-19 condition in both groups after performing propensity score matching.

Results

We conducted interviews for 53 out of 128 patients with Omicron and obtained 502 responses in the control group. After matching cases with controls, 18 patients from both groups had improved covariate balance of the factors: older adult, female sex, obesity, and vaccination status. There were no significant differences in the prevalence of each post COVID-19 condition between the two groups. The number of patients with at least one post COVID-19 condition in the Omicron and control groups were 1 (5.6%) and 10 (55.6%) (p = 0.003), respectively.

Conclusions

The prevalence of post Omicron COVID-19 conditions was less than that of the other strains. Further research with a larger sample size is needed to investigate the precise epidemiology of post COVID-19 condition of Omicron, and its impact on health-related quality of life and social productivity.

2-Dimensional Genetic Algorithm Exhibited an Essentiality of Gene Interaction for Evolution

Organisms consist of several genetic factors differing between species. However, the evolutionary effects of gene interactions on the evolutionary rate, adaptation, and divergence of organisms remain unknown. In a previous study, the 2-dimensional genetic algorithm (2DGA) program, including a gene interaction parameter, could simulate punctuated equilibrium under the disparity mode. Following this, we verified the effect of the number of gene interactions (gene cluster size) on evolution speed, adaptation, and divergence using the advanced 2DGA program. In this program, the population was replicated, mutated, and selected for 200,000 generations, and the fitness score, divergence, number of population, and genotype were output and plotted. The genotype data were used for evaluating the phylogenetic relations among the population. The gene cluster size 1) affected the disparity and parity mutagenesis modes differently, 2) determined the growth/exclusion rate and error threshold, and 3) accelerated or decelerated the population's speed of evolutionary advancement. In particular, when the gene cluster size expanded, the rate of increase in fitness scores decreased independently of the mutation rate and mode of mutation (disparity mode/parity mode). The mutation rate at the error threshold was also decreased by expanding the gene cluster size. Dendrograms traced the genotypes of the simulated population, indicating that the disparity mode caused the evolutionary process to enter 1) a stun mode, 2) an evolution mode, or 3) a divergence mode based on the mutation rate and gene cluster size, while the parity mode did not cause the population to enter a stun mode. Based on the above findings, we compared the predictions of the present study with evolution observed in the laboratory or the natural world and the processes of ongoing virus evolution, suggesting that our findings possibly explained the real evolution.

Denosumab-related osteonecrosis of the jaw after tooth extraction and the effects of a short drug holiday in cancer patients: a multicenter retrospective study

Pre-existing inflammation, corticosteroid therapy, periapical periodontitis, longer duration of denosumab therapy, and female sex were significantly associated with an increased risk of denosumab-related osteonecrosis of the jaw after tooth extraction in patients with cancer on oncologic doses of denosumab. A short drug holiday did not protect against this complication.

INTRODUCTION

This study retrospectively investigated the relationship between various risk factors, including brief discontinuation of denosumab, and development of denosumab-related osteonecrosis of the jaw (DRONJ) after tooth extraction in patients with cancer who were receiving oncologic doses of this agent.

METHODS

Data were collected on demographic characteristics, duration of denosumab therapy, whether or not denosumab was discontinued before tooth extraction (drug holiday), duration of discontinuation, presence of pre-existing inflammation, and whether or not additional surgical procedures were performed. Risk factors for DRONJ after tooth extraction were evaluated by univariate and multivariate analyses.

RESULTS

A total of 136 dental extractions were performed in 72 patients (31 men, 41 women) with cancer who were receiving oncologic doses of denosumab. Post-extraction DRONJ was diagnosed in 39 teeth (28.7%) in 25 patients. Tooth extraction was significantly associated with development of DRONJ only in patients with pre-existing inflammation (odds ratio [OR] 243.77), those on corticosteroid therapy (OR 73.50), those with periapical periodontitis (OR 14.13), those who had been taking oncologic doses of denosumab for a longer period (OR 4.69), and in women (OR 1.04). There was no significant difference in the occurrence of DRONJ between patients who had a drug holiday before tooth extraction and those who did not.

CONCLUSIONS

These findings suggest that inflamed teeth should be extracted immediately in patients with cancer who are receiving oncologic doses of denosumab. Drug holidays have no significant impact on the risk of DRONJ.

Co-Isolation and Characterization of Two Pandoraviruses and a Mimivirus from a Riverbank in Japan

Giant viruses, like pandoraviruses and mimiviruses, have been discovered from diverse environments, and their broad global distribution has been established. Here, we report two new isolates of Pandoravirus spp. and one Mimivirus sp., named Pandoravirus hades, Pandoravirus persephone, and Mimivirus sp. isolate styx, co-isolated from riverbank soil in Japan. We obtained nearly complete sequences of the family B DNA polymerase gene (polB) of P. hades and P. persephone; the former carried two known intein regions, while the latter had only one. Phylogenetic analysis revealed that the two new pandoravirus isolates are closely related to Pandoravirus dulcis. Furthermore, random amplified polymorphic DNA analysis revealed that P. hades and P. persephone might harbor different genome structures. Based on phylogenetic analysis of the partial polB sequence, Mimivirus sp. isolate styx belongs to mimivirus lineage A. DNA staining suggested that the Pandoravirus spp. asynchronously replicates in amoeba cells while Mimivirus sp. replicates synchronously. We also observed that P. persephone- or Mimivirus sp. isolate styx-infected amoeba cytoplasm is extruded by the cells. To the best of our knowledge, we are the first to report the isolation of pandoraviruses in Asia. In addition, our results emphasize the importance of virus isolation from soil to reveal the ecology of giant viruses.

Distribution of SNSs in Mimivirus Genomes and the Classification of Mimiviruses Isolated from Japan

Mimiviruses have been detected in various habitats. Analyses of single nucleotide substitutions (SNSs) have revealed that SNSs are mainly localized on both ends of the mimivirus genome, and mimivirus lineage A has been split into three genotype groups; therefore, mimiviruses may be classified into lineages and genotype groups based on SNSs. We isolated 9 mimiviruses from Japan and analyzed SNSs. These isolates were classified as lineage A genotype group type 2, suggesting that the local diversity of members of the family Mimiviridae isolated from Acanthamoeba spp. is lower than that of giant viruses from other families isolated in Japan.

P1958Baseline glycated hemoglobin level was differently associated with long-term prognosis in peripheral artery disease patients with and without hemodialysis

Introduction

Diabetes (DM) is the leading cause of induction of hemodialysis (HD), and both are major prognostic factors in patients with peripheral artery disease (PAD). However, the prognostic importance of baseline glycated hemoglobin (HbA1c) levels in PAD patients with and without HD is yet to be elucidated.

Purpose

We hypothesized that baseline HbA1c levels had different prognostic impacts after endovascular therapy (EVT) in between PAD patients with and those without regular HD.

Methods

This observational study included 643 consecutive patients who received EVT between 2013 and 2017. Each of 313 HD patients and 330 Non-HD patients was respectively divided into 2 groups by the comorbidity of diabetes, and DM patients were further divided into 3 subgroups depending on HbA1c level at the time of EVT; DM-Low (HbA1c: <6.0%), DM-Mid (6.1–7.0%), and DM-High (>7.1%) groups. The primary endpoint of this study was major amputation-free survival (AFS).

Results

HD group included significantly more patients presenting critical limb ischemia than Non-HD group (46.6% vs. 30.0%, p<0.001). During the observation period after EVT, there were 81 events (25.9%), including 55 death and 26 major amputations in HD group, and 45 events (13.6%), including 30 death and 15 major amputations in Non-HD group. Kaplan-Meier analysis revealed that DM patients had a significantly higher AFS rate in HD group (Log-rank: p=0.003, Figure A). In contrast, in Non-HD group, there was no statistical difference in AFS between DM and Non-DM patients (p=0.36). In Cox regression analysis in HD group, the higher HbA1c-DM group showed the higher hazard ratio (HR) for AFS (p=0.039, Figure B), and DM patients with HbA1c >6.0% had significantly higher HR than Non-DM patients. Whereas, in Non-HD group, HbA1c-DM class adversely associated with HR for AFS (p=0.003), even any classes did not reach statistical differences from Non-DM patients.

Figure 1

Conclusions

Comorbidity of diabetes at the time of EVT worsened long-term prognosis in PAD patients receiving regular HD, but not in those without HD. Additionally, baseline HbA1c levels oppositely affected prognosis in PAD patients with and without HD.

Visualization of giant virus particles and development of "VIRAMOS" for high school and university biology course

Several educational trials on handling viruses and or virology have been reported. However, given their small size, direct visualization of these viruses under a microscope has been rarely performed. The so-called "giant viruses" are larger than other viruses with a particle size greater than 200-300 nm. This enables their direct visualization under a light microscope more easily than other viruses. In this study, we developed two new types of teaching material for learning about viruses and cellular organisms using mimivirus, one of the well-known giant viruses. One teaching material involves using glass slides with enclosed mimivirus particles, and another is a paper-based teaching material, named VIRAMOS (http://tlab-edusys.azurewebsites.net/content/viramos_en.pdf). Using these, students can investigate and learn about viruses and cellular organisms. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):426-431, 2019.

Fifteen Marseilleviruses Newly Isolated From Three Water Samples in Japan Reveal Local Diversity of Marseilleviridae

The family Marseilleviridae, defined as a group of icosahedral double-stranded DNA viruses with particle size of approximately 250 nm and genome size of 350-380 kbp, belongs to the nucleo-cytoplasmic family of large DNA viruses. The family Marseilleviridae is currently classified into lineages A-E. In this study, we isolated 12 or 15 new members of the family Marseilleviridae from three sampling locations in Japan. Molecular phylogenetic analysis of the MCP genes showed that the new viruses could be further classified into three groups, hokutoviruses, kashiwazakiviruses, and kyotoviruses. Hokutoviruses were closely related to lineage B, kyotoviruses were related to lineage A, and kashiwazakiviruses were also classified into lineage B but a new putative subgroup of lineage B, revealing the diversity of this lineage. Interestingly, more than two viruses with slightly different MCP genes were isolated from a single water sample from a single location, i.e., two hokutoviruses and one kashiwazakivirus were isolated from a small reservoir, five kashiwazakiviruses from the mouth of a river, and five kyotoviruses from fresh water of a river, suggesting that several milliliters of water samples contain several types of giant viruses. Amoeba cells infected with hokutoviruses or kashiwazakiviruses exhibited a "bunch" formation consisting of normal and infected cells similarly to a tupanvirus, whereas cells infected with kyotoviruses or tokyovirus did not. These results suggest the previously unrecognized local diversity of the family Marseilleviridae in aquatic environments.

Abstract P3-05-09: Prognostic factors for therapeutic personalized peptide vaccines in patients with metastatic recurrent breast cancer

Background: We have previously reported the prognostic role of humoral antigen spreading response against prostate-related antigen (PRA) for metastatic recurrent breast cancer (mrBC) patients who received personalized peptide vaccine (PPV) therapy (Toh U, SABCS 2015). The prognostic effect was additionally evaluated by the clinical relevant factors including intrinsic subtype, the regimens of combined chemo-hormonal therapies in present study.

Methods:We analyzed serum IgG responses to all of the peptide candidates included PRAs (PSA, PAP and PMSA) after PPV therapy by the Luminex systemusing peripheral blood samples from 77 vaccinated mrBC patients. The clinical factors and relevant events were statistically evaluated.

Results: After 6 and 12cycles of PPV therapy, the serum IgG of anti-PSA, anti-PAP, and/or anti-PMSA increased significantly in 31 patients (PRA response group), and the median progression free survival (PFS) and median overall survival (OS) were 8.1 and 14.3 months, but were 5.1 and 10.8 months, respectively, in the remaining 46 patients with no anti-PRA IgG response (PRA non-response Group). The anti-PRA IgG level was marginally correlated withPFS (p=0.059) and OS (p=0.082) between these two groups, which was a significant prognostic factor for PFS (Log-rank: 0.009) in estrogen-positive cancer patients (ER+). The statistical analyses showed that the clinical outcome was in favor of &gt; 60 year-old patients, those with longer PPV therapies (&gt;3 months), and those who received combined standard hormonal therapies or bisphosphonate/anti-RANKL therapy.

Conclusions: This study indicated a clinical significance between the pre-and post- PPV therapy measurement of serum anti-PRA IgG in patients with mrBC, which may be a useful prognostic marker for monitoring peptide vaccine treatment outcomes, particularly for patients &gt; 60 years with ER+ breast cancer. These results also suggest that the immunotherapeutic peptide vaccine could be efficiently combined with hormonal therapy, anti-HER2 therapy, and bisphosphonate/anti-RANKL therapy in mrBC patients.

Citation Format: Toh U, Saku S, Iwakuma N, Takao Y, Okabe M, Akashi M, Yamada A, Shichijo S, Itoh K, Akagi Y. Prognostic factors for therapeutic personalized peptide vaccines in patients with metastatic recurrent breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-09.

Transposition of insertion sequence IS256Bsu1 in Bacillus subtilis 168 is strictly dependent on recA

We developed an insertion sequence transposition detection system called the "jumping cat assay" and applied it to the Bacillus subtilis chromosome using IS256Bsu1 derived from B. subtilis natto. The high frequency of transposition enabled us to explore host factors; combining the assay and genetic analyses revealed that recA is essential for the transposition of IS256Bsu1. Detailed analyses using various domain mutants of recA demonstrated that this essentiality is not related to the function of recA in homologous recombination. Instead, the ATP binding and hydrolysis function seemed to be crucial for IS transposition. To elucidate the role of recA, we focused on the muB gene of the enterobacteriophage Mu. Based on information from the NCBI Conserved Domain Database, both MuB and RecA belong to the P-loop dNTPase superfamily. Further experiments revealed that muB complements the transposition-defective phenotype of a recA deletant, although it could not rescue UV sensitivity. These results suggest that recA shares a common function with muB that helps the transposition of IS256Bsu1 in B. subtilis.

Survival of Brånemark System Mk III implants and analysis of risk factors associated with implant failure

The purpose of this study was to retrospectively investigate the outcomes of Brånemark System Mk III TiUnite/Groovy implants placed in patients at Kobe University Hospital. Various risk factors for implant failure, including mechanical coupling, were investigated by univariate and multivariate analysis. The predictive variables investigated included age, sex, smoking habit, general health, history of radiation therapy, application of a dentomaxillary prosthesis, type of prosthesis, use of alveolar bone augmentation, site of implant insertion, mechanical coupling between implants, and the length and diameter of the implants. Of the 907 implants investigated, only 23 were unsuccessful; the overall survival rate was 96.7%. Increased age, radiation therapy, application of a removable prosthesis or dentomaxillary prosthesis, lack of mechanical coupling between implants, and shorter implants (≤8.5mm) were significant risk factors for implant failure according to univariate analysis (P<0.05). Multivariate analysis identified a significant association (P<0.05) between dental implant failure and a lack of mechanical coupling between implants (odds ratio 6.88) and shorter implants (≤8.5mm) (odds ratio 3.43). The findings of this study demonstrated multivariate relationships between various risk factors and dental implant failure.

THREE-YEAR RETENTION OF RADIOACTIVE CAESIUM IN THE BODY OF TEPCO WORKERS INVOLVED IN THE FUKUSHIMA DAIICHI NUCLEAR POWER STATION ACCIDENT

Direct measurements of seven highly exposed workers at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station accident have been performed continuously since June 2011. Caesium clearance in the monitored workers is in agreement with the biokinetic models proposed by the International Commission on Radiological Protection. After 500 d from the initial measurement, however, the caesium clearance slowed. It was thought to be unlikely that additional Cs intake had occurred after the initial intake, as activity in foods was kept low. And, the contribution from the detector over the chest was enhanced with time. This indicates that insoluble Cs particles were inhaled and a long metabolic rate showed.

Synthesis and Anticoagulant Properties of a Novel Heparinoid N-Sulfate-Bearing Vinylpolymer

A novel heparinoid polymer was prepared with an N-sulfate side chain group by sulfation of poly( N-vinylacetamide-co-vinylamine) [poly(NVA-co-VAm)] which was obtained by the partial hydrolysis of poly( N-vinylacetamide) [poly(NVA)]. The hydrolysis of poly(NVA) was controlled by reaction time and temperature and the sulfation of poly(NVA-co-VAm) was performed with chlorosulfonic acid. Poly( N-vinylacetamide-co-vinylamine-co-vinylsulfamic acid) [poly(NVA-co-VAm-co-VSA)] was confirmed by means of IR spectroscopy, and the degree of sulfation of poly(NVA-co-VAm-co-VSA) was estimated by elemental analysis. The anticoagulant properties of poly(NVA-co-VAm-co-VSA) were evaluated using the Lee-White clotting test and activated partial thromboplastin time (APTT) test. The human whole blood clotting time in the presence of poly(NVA-co-VAm-co-VSA) was prolonged compared with poly(NVA) and poly(NVA-co-VAm). The clotting time was prolonged with increased N-sulfate groups on the polymer. APTT tests of the polymer were also prolonged with N-sulfate increases. The results suggest that the N-sulfate components on the polymer can endow anticoagulant activity to synthetic polymers.

Distribution of human single-nucleotide polymorphisms is approximated by the power law and represents a fractal structure

Single-nucleotide polymorphisms (SNPs) are one of the main causes of evolution. The distribution of human SNPs, which were examined in detail genomewide, was analyzed. Three discrete databases of human SNPs were used for this analysis, and similar results were obtained from these databases. It was found that the distribution of the distance between SNPs was approximated by the power law, and the shape of the regions including SNPs had the so-called fractal structure. Although the reason why the distribution of SNPs obeys such a certain law of physics is unclear, a speculation was attempted in connection with the three-dimensional structure of human chromatin which has a fractal structure.

Prospective study of dental intervention for hematopoietic malignancy

Various chemotherapeutic agents used in patients with hematopoietic malignancy cause serious side effects, including myelosuppression and immunosuppression. Immunosuppression makes patients more susceptible to infection, resulting in an increased risk of infectious complications, including the development of severe septicemia that may be life-threatening. It is necessary for dental staff to be familiar with an appropriate protocol in such cases and to share information about the chemotherapy with a hematologist. To verify the effectiveness of our dental intervention protocol, we conducted a prospective study on the incidence of complications for each myelosuppressive grade of chemotherapy in patients with hematopoietic malignancy. We compared the incidence of complications between treatment P (patients who finished all the dental treatments according to the protocol) and treatment Q (patients who did not) per grade (A, B, C, D) and incidence of systemic or oral findings. We also compared the incidence of oral complication related to the residual teeth between first chemo (patients who were undergoing chemotherapy for the first time) and prior chemo (not the first time). There were significant differences in inflammatory complications between treatment P and treatment Q. We found that both systemic and oral inflammatory complications increased with higher-grade myelosuppressive chemotherapy. Additionally, there was a significant difference between the incidence of oral complications related to the residual teeth between first chemo and prior chemo. Complete implementation of the dental intervention protocol was associated with fewer oral and systemic infectious and inflammatory complications in patients with hematopoietic malignancies undergoing chemotherapy. The incidence of oral and systemic complications also increased with grade of chemotherapy. These results support the validity of our dental intervention protocol. We should pay close attention to the oral state of de novo hematopoietic malignancy patients.

Retrospective study of changes in the sensitivity of the oral mucosa: sagittal split ramus osteotomy (SSRO) versus intraoral vertical ramus osteotomy (IVRO)

We investigated changes in the sensitivity of cutaneous points and the oral mucosa after sagittal split ramus osteotomy (SSRO) and assessed the differences between SSRO and intraoral vertical ramus osteotomy (IVRO). The subjects included in this study were 46 patients with mandibular prognathism who underwent IVRO (88 rami) and 30 patients who underwent SSRO (59 rami). An objective evaluation of the neurosensory status of each patient was completed preoperatively and at 1, 4, 8, 12, and 24 weeks postoperatively. Other variables studied for each patient included sex, age, magnitude of mandibular setback, and amount of blood loss during surgery. We found that a neurosensory recovery occurred earlier in the oral mucosa than at cutaneous points. The number of oral mucosa points showing reduced neurosensory function and neurosensory disturbance after SSRO was significantly higher than after IVRO at 1, 4, and 8 weeks (P<0.05). The nerve recovery observed after SSRO was delayed for a longer period than that noted in our previous study of IVRO. In conclusion, we found changes in sensitivity at cutaneous points and the oral mucosa after SSRO and assessed the differences between SSRO and IVRO.

Sequential changes in oral dryness evaluated by a moisture-checking device in patients with oropharyngeal cancer during chemoradiotherapy: a pilot study

PURPOSE

Although oral dryness is a predictor for oral mucositis caused by Chemoradiotherapy (CRT) for head and neck cancer, there have been few reports evaluating the sequential changes in oral dryness during therapy. Studies have determined the reliability and usefulness of a moisture-checking device for the evaluation of dry mouth. This study aimed to evaluate the oral moisture level in patients with Oropharyngeal Cancer (OPC) during CRT using a moisture-checking device.

METHODS

Oral moisture level was measured with an oral moisture-checking device (Moisture Checker Mucus®) at the lingual and buccal mucosa before, at the midpoint, and at the end of CRT in patients with OPC. Sequential changes in oral dryness were evaluated.

RESULTS

A significant decrease in oral moisture level at the lingual mucosa was found when comparing values before and at the end of CRT (P=0.017). Decreases in oral moisture level at the buccal mucosa were not significant.

CONCLUSIONS

A moisture-checking device is considered a useful tool for determining the sequential changes in oral dryness during CRT for head and neck cancer. Our findings provide a basis for future larger long-term studies of oral moisture levels in OPC patients receiving CRT.

Relevance of GC content to the conservation of DNA polymerase III/mismatch repair system in Gram-positive bacteria

The mechanism of DNA replication is one of the driving forces of genome evolution. Bacterial DNA polymerase III, the primary complex of DNA replication, consists of PolC and DnaE. PolC is conserved in Gram-positive bacteria, especially in the Firmicutes with low GC content, whereas DnaE is widely conserved in most Gram-negative and Gram-positive bacteria. PolC contains two domains, the 3′-5′exonuclease domain and the polymerase domain, while DnaE only possesses the polymerase domain. Accordingly, DnaE does not have the proofreading function; in Escherichia coli, another enzyme DnaQ performs this function. In most bacteria, the fidelity of DNA replication is maintained by 3′-5′ exonuclease and a mismatch repair (MMR) system. However, we found that most Actinobacteria (a group of Gram-positive bacteria with high GC content) appear to have lost the MMR system and chromosomes may be replicated by DnaE-type DNA polymerase III with DnaQ-like 3′-5′ exonuclease. We tested the mutation bias of Bacillus subtilis, which belongs to the Firmicutes and found that the wild type strain is AT-biased while the mutS-deletant strain is remarkably GC-biased. If we presume that DnaE tends to make mistakes that increase GC content, these results can be explained by the mutS deletion (i.e., deletion of the MMR system). Thus, we propose that GC content is regulated by DNA polymerase and MMR system, and the absence of polC genes, which participate in the MMR system, may be the reason for the increase of GC content in Gram-positive bacteria such as Actinobacteria.

Cedar and cypress pollen counts are associated with the prevalence of allergic diseases in Japanese schoolchildren

BACKGROUND

Patients allergic to pollen have been known to become more symptomatic during pollen season compared with the nonpollen season. However, there are few studies regarding whether higher exposure to pollen might increase the prevalence of allergic diseases.

METHODS

An ecological analysis was conducted to evaluate whether pollen exposure is associated with the prevalence of allergic diseases in schoolchildren. Pollen count data of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa), which are the major pollen allergens in Japan, were obtained from each prefecture. The prevalence of allergic diseases in schoolchildren in each prefecture was based on a nationwide cross-sectional survey using the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

After omitting three prefectures where pollen data were not available, data of 44 prefectures were analysed. The prevalence of allergic rhinoconjunctivitis in children aged 6-7 years was positively associated with both cedar and cypress pollen counts (P = 0.01, both), whereas the prevalence of allergic rhinoconjunctivitis in children aged 13-14 years was positively associated with only cypress pollen counts (P = 0.003). Furthermore, the prevalence of asthma was positively associated with cedar pollen counts in 6- to 7-year-old children (P = 0.003) but not cypress pollen counts in either age group.

CONCLUSIONS

There are ecological associations between pollen counts and the prevalence of allergic diseases in Japanese schoolchildren. Further studies are needed to determine whether the difference between the effects of cedar and cypress pollens is attributable to pollen counts or allergenicity.

Two types of myeloperoxidase-antineutrophil cytoplasmic autoantibodies with a high affinity and a low affinity in small vessel vasculitis

OBJECTIVE

Myeloperoxidase (MPO) -anti-neutrophil cytoplasmic autoantibodies (ANCAs) are detected at a high rate in microscopic polyangiitis and renal-limited vasculitis. MPO-ANCA titers are not always reflected in the disease activity. We studied the titer and affinity of MPO-ANCA in sera from patients in relation to vasculitis activity.

METHODS

Blood samples were collected from 27 newly diagnosed or relapsed patients with MPO-ANCA-associated vasculitides. The MPO-ANCA titer was determined by a direct enzyme-linked immunosorbent assay (ELISA) using homogeneously purified human MPO of leukocytes. The MPO-ANCA affinity was expressed as IC50 that was determined by a competitive inhibition method using the ELISA.

RESULTS

The MPO-ANCA affinity of 27 sera from 27 patients could be classified into a high-affinity type (14 sera) and a low-affinity type (13 sera). The mean values for IC50 in the two types were 0.15+/-0.06 microg/ml and 0.54+/-0.15 microg/ml, and the difference was statistically significant (p<0.0000000684). Between the two groups of patients divided by the affinity, there were differences in the Birmingham Vasculitis Activity Score (BVAS): and in C-reactive protein (CRP): (p<0.00093 and p<0.00129, respectively). However, the difference in titer was not statistically significant (p<0.0265). The affinity remained steady from the disease onset to remission or relapse.

CONCLUSIONS

The affinity of MPO-ANCA from patients with MPO-ANCA-associated vasculitides were largely distinguished into a high and a low affinity, irrespective of the level of MPO-ANCA titers, and may be helpful for assessment of vasculitis activity affecting mainly the kidney and the lung.

Dose estimation of a soft X-ray exposure incident

A dose reconstruction was carried out on a case in which a worker was exposed to soft x rays using time motion studies, an ionization chamber for low energy photon measurements, and CdZnTe (CZT) spectrometry. The worker estimated his dose to be over 600 mSv. However, the doses to the skin and testes were evaluated to be 14 and 0.44 mSv, respectively, with an effective dose of 0.099 mSv.