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1.
Nature ; 590(7847): 561-565, 2021 02.
Article in English | MEDLINE | ID: mdl-33627814

ABSTRACT

The fundamental building blocks of the proton-quarks and gluons-have been known for decades. However, we still have an incomplete theoretical and experimental understanding of how these particles and their dynamics give rise to the quantum bound state of the proton and its physical properties, such as its spin1. The two up quarks and the single down quark that comprise the proton in the simplest picture account only for a few per cent of the proton mass, the bulk of which is in the form of quark kinetic and potential energy and gluon energy from the strong force2. An essential feature of this force, as described by quantum chromodynamics, is its ability to create matter-antimatter quark pairs inside the proton that exist only for a very short time. Their fleeting existence makes the antimatter quarks within protons difficult to study, but their existence is discernible in reactions in which a matter-antimatter quark pair annihilates. In this picture of quark-antiquark creation by the strong force, the probability distributions as a function of momentum for the presence of up and down antimatter quarks should be nearly identical, given that their masses are very similar and small compared to the mass of the proton3. Here we provide evidence from muon pair production measurements that these distributions are considerably different, with more abundant down antimatter quarks than up antimatter quarks over a wide range of momenta. These results are expected to revive interest in several proposed mechanisms for the origin of this antimatter asymmetry in the proton that had been disfavoured by previous results4, and point to future measurements that can distinguish between these mechanisms.

3.
Lett Appl Microbiol ; 73(1): 81-87, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33797068

ABSTRACT

We present estimations for the amounts of Arcobacter (A. butzleri, A. cryaerophilus and A. skirrowii) and Campylobacter (C. jejuni, C. coli and C. fetus) species in retail chicken, pork and beef meat using PCR-MPN. Arcobacter butzleri, A. cryaerophilus and C. jejuni were found in 100, 60 and 55% of chicken samples, respectively. No other Arcobacter or Campylobacter species were found in chicken. The MPNs of A. butzleri, A. cryaerophilus and C. jejuni were greater than 103 per 100 g in 50, 0 and 5% of samples, respectively. The MPN of A. butzleri was higher than that of C. jejuni in 95% of samples. In pork, A. butzleri and A. cryaerophilus were detected in 10 and 11 (50 and 55%) of 20 samples, respectively. No other Arcobacter or Campylobacter species were found in pork. Only one pork sample had more than 103 MPN per 100 g of A. cryaerophilus. For beef, only two samples tested positive for A. cryaerophilus, at 4600 and 92 MPN per 100 g. Overall, we found that the presence and MPNs of Arcobacter species are very high in chicken. In contrast, the positive ratios of Arcobacter in pork were high as chicken samples, but MPNs were lower than in chicken.


Subject(s)
Arcobacter/physiology , Campylobacter/physiology , Food Microbiology , Meat/microbiology , Animals , Arcobacter/genetics , Arcobacter/isolation & purification , Campylobacter/genetics , Campylobacter/isolation & purification , Cattle , Chickens , Japan , Polymerase Chain Reaction , Pork Meat/microbiology , Red Meat/microbiology
4.
Ann Oncol ; 30(9): 1521-1530, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31282941

ABSTRACT

BACKGROUND: The tumor immune microenvironment (TIME) of lung cancer brain metastasis is largely unexplored. We carried out immune profiling and sequencing analysis of paired resected primary tumors and brain metastases of non-small-cell lung carcinoma (NSCLC). PATIENTS AND METHODS: TIME profiling of archival formalin-fixed and paraffin-embedded specimens of paired primary tumors and brain metastases from 39 patients with surgically resected NSCLCs was carried out using a 770 immune gene expression panel and by T-cell receptor beta repertoire (TCRß) sequencing. Immunohistochemistry was carried out for validation. Targeted sequencing was carried out to catalog hot spot mutations in cancer genes. RESULTS: Somatic hot spot mutations were mostly shared between both tumor sites (28/39 patients; 71%). We identified 161 differentially expressed genes, indicating inhibition of dendritic cell maturation, Th1, and leukocyte extravasation signaling pathways, in brain metastases compared with primary tumors (P < 0.01). The proinflammatory cell adhesion molecule vascular cell adhesion protein 1 was significantly suppressed in brain metastases compared with primary tumors. Brain metastases exhibited lower T cell and elevated macrophage infiltration compared with primary tumors (P < 0.001). T-cell clones were expanded in 64% of brain metastases compared with their corresponding primary tumors. Furthermore, while TCR repertoires were largely shared between paired brain metastases and primary tumors, T-cell densities were sparse in the metastases. CONCLUSION: We present findings that suggest that the TIME in brain metastases from NSCLC is immunosuppressed and comprises immune phenotypes (e.g. immunosuppressive tumor-associated macrophages) that may help guide immunotherapeutic strategies for NSCLC brain metastases.


Subject(s)
Biomarkers, Tumor/immunology , Brain Neoplasms/immunology , Carcinoma, Non-Small-Cell Lung/immunology , Neoplasm Proteins/immunology , Tumor Microenvironment/immunology , Adult , Aged , Biomarkers, Tumor/genetics , Brain Neoplasms/pathology , Brain Neoplasms/secondary , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/surgery , Dendritic Cells/immunology , Female , Gene Expression Regulation, Neoplastic/immunology , Humans , Immunohistochemistry , Male , Middle Aged , Mutation/genetics , Neoplasm Proteins/genetics , Receptors, Antigen, T-Cell, alpha-beta/genetics , Receptors, Antigen, T-Cell, alpha-beta/immunology , Tumor Microenvironment/genetics
5.
Eur J Neurol ; 26(9): 1205-1211, 2019 09.
Article in English | MEDLINE | ID: mdl-30980575

ABSTRACT

BACKGROUND AND PURPOSE: Corticobasal syndrome (CBS) is pathologically characterized by tau deposits in neuronal and glial cells and by reactive astrogliosis. In several neurodegenerative disorders, 18 F-THK5351 has been observed to bind to reactive astrocytes expressing monoamine oxidase B. In this study, the aim was to investigate the progression of disease-related pathology in the brains of patients with CBS using positron emission tomography with 18 F-THK5351. METHODS: Baseline and 1-year follow-up imaging were acquired using magnetic resonance imaging and positron emission tomography with 18 F-THK5351 in 10 subjects: five patients with CBS and five age-matched normal controls (NCs). RESULTS: The 1-year follow-up scan images revealed that 18 F-THK5351 retention had significantly increased in the superior parietal gyrus of the patients with CBS compared with the NCs. The median increases in 18 F-THK5351 accumulation in the patients with CBS were 6.53% in the superior parietal gyrus, 4.34% in the precentral gyrus and 4.33% in the postcentral gyrus. In contrast, there was no significant increase in the regional 18 F-THK5351 retention in the NCs. CONCLUSIONS: Longitudinal increases in 18 F-THK5351 binding can be detected over a short interval in the cortical sites of patients with CBS. A monoamine oxidase B binding radiotracer could be useful in monitoring the progression of astrogliosis in CBS.


Subject(s)
Aminopyridines , Basal Ganglia Diseases/diagnostic imaging , Disease Progression , Positron-Emission Tomography , Quinolines , Radiopharmaceuticals , Tauopathies/diagnostic imaging , Aged , Aminopyridines/pharmacokinetics , Female , Follow-Up Studies , Humans , Male , Middle Aged , Quinolines/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics
6.
Clin Genet ; 94(2): 232-238, 2018 08.
Article in English | MEDLINE | ID: mdl-29700822

ABSTRACT

Leukoencephalopathies encompass all clinical syndromes that predominantly affect brain white matter. Genetic diagnosis informs clinical management of these patients, but a large part of the genetic contribution to adult leukoencephalopathy remains unresolved. To examine this genetic contribution, we analyzed genomic DNA from 60 Japanese patients with adult leukoencephalopathy of unknown cause by next generation sequencing using a custom-designed gene panel. We selected 55 leukoencephalopathy-related genes for the gene panel. We identified pathogenic mutations in 8 of the 60 adult leukoencephalopathy patients (13.3%): NOTCH3 mutations were detected in 5 patients, and EIF2B2, CSF1R, and POLR3A mutations were found independently in 1 patient each. These results indicate that cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) caused by NOTCH3 mutations is the most frequent adult leukoencephalopathy in our cohort. Moreover, brain imaging analysis indicates that CADASIL patients who do not present typical phenotypes may be underdiagnosed if not examined genetically.


Subject(s)
CADASIL/genetics , Genetic Predisposition to Disease , Leukoencephalopathies/genetics , Receptor, Notch3/genetics , Adolescent , Adult , Aged , Aged, 80 and over , CADASIL/diagnostic imaging , CADASIL/physiopathology , Cohort Studies , Eukaryotic Initiation Factor-2B/genetics , Genetic Testing , Humans , Leukoencephalopathies/diagnostic imaging , Leukoencephalopathies/physiopathology , Magnetic Resonance Imaging , Middle Aged , Mutation , Phenotype , RNA Polymerase III/genetics , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Exome Sequencing
7.
Eur J Neurol ; 24(1): 130-136, 2017 01.
Article in English | MEDLINE | ID: mdl-27797445

ABSTRACT

BACKGROUND AND PURPOSE: Visualization of pathogenic protein aggregates is crucial to elucidate pathomechanisms and to make an accurate diagnosis in many neurodegenerative conditions. Aggregates of the microtubule-binding protein, tau, are one of the most important pathogenic molecules in neurodegenerative disorders. Progressive supranuclear palsy (PSP) is characterized by the deposition of tau proteins in some specific area such as the basal ganglia and brainstem. We tried to detect tau lesions in the brains of living patients with PSP with a novel positron emission tomography (PET) tracer, [18 F]THK-5351, which we have recently developed. METHODS: Paraffin-embedded brain sections of the patients with PSP were used for autoradiography with [3 H]THK-5351 and immunohistochemistry. Nine healthy controls, 13 patients with Alzheimer's disease and three patients with PSP participated in this PET study with [18 F]THK-5351. To detect amyloid-ß deposition, PET imaging with Pittsburgh compound B was also performed. RESULTS: Autoradiography in the brain sections of patients with PSP demonstrated [3 H]THK-5351 binding to tau deposits with a high selectivity. Although patients with PSP exhibited no remarkable [18 F]THK-5351 retention in the temporal cortex, significantly higher tracer retention was observed in the globus pallidus and midbrain. In contrast, amyloid imaging with Pittsburgh compound B showed no remarkable accumulation in the cerebral cortex of PSP. CONCLUSIONS: We conclude that [18 F]THK-5351 PET can potentially be used to detect the regional brain distribution of tau lesions in PSP, thereby facilitating the differential diagnosis of neurodegenerative disorders associated with tau protein.


Subject(s)
Brain/diagnostic imaging , Positron-Emission Tomography , Supranuclear Palsy, Progressive/diagnostic imaging , tau Proteins/metabolism , Aged , Aged, 80 and over , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Aniline Compounds , Brain/metabolism , Brain/pathology , Female , Humans , Male , Supranuclear Palsy, Progressive/metabolism , Supranuclear Palsy, Progressive/pathology , Thiazoles
8.
J Appl Microbiol ; 122(1): 268-278, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27718315

ABSTRACT

AIM: This study assessed whether multilocus variable-number tandem repeat analysis (MLVA) and antimicrobial susceptibility testing discriminated diarrhoeagenic atypical enteropathogenic Escherichia coli (aEPEC) from aEPEC indigenous to domestic animals or healthy people. METHODS AND RESULTS: MLVA genotyping of 142 aEPEC strains isolated from foods and faecal samples of domestic animals and humans revealed 126 distinct MLVA profiles that distributed to four clusters, yielding a Simpson's index of diversity (D) of 99·8%. Cluster 2 included 87% of cattle isolates and 67% of patient isolates. The plurality (15/34, 44%) of strains from healthy humans mapped to Cluster 1, while half (18/41, 44%) of the swine strains belonged to Cluster 4. Testing for antimicrobial susceptibility revealed that 52 strains (37%) of aEPEC were resistant to one or more agents; only 10 strains (7%) exhibited resistance to more than three agents. Strains isolated from swine or food exhibited a wider variety of resistance phenotypes than bovine or human strains. CONCLUSIONS: MLVA assigned the aEPEC isolates from cattle and patients to Cluster 2, distinct from aEPEC from other sources. Hog yards may be a larger source of drug-resistant strains than are cattle ranches. SIGNIFICANCE AND IMPACT OF THE STUDY: MLVA suggests that human diarrhoeagenic aEPEC are derived from cattle and are distinct from strains carried by healthy people and other animals. Cattle appear to be reservoirs of human diarrhoeagenic aEPEC.


Subject(s)
Anti-Bacterial Agents/pharmacology , Enteropathogenic Escherichia coli/drug effects , Enteropathogenic Escherichia coli/isolation & purification , Escherichia coli Infections/microbiology , Escherichia coli Infections/veterinary , Feces/microbiology , Food Microbiology , Animals , Cattle , Drug Resistance, Bacterial , Enteropathogenic Escherichia coli/classification , Enteropathogenic Escherichia coli/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Genotype , Humans , Minisatellite Repeats , Swine
9.
Eur J Clin Microbiol Infect Dis ; 35(4): 665-71, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26864040

ABSTRACT

This study was performed to determine whether multiparous pregnant women are prone to influenza. A questionnaire survey was conducted at 19 centres located throughout Japan, targeting all 6,694 postpartum women within 7 days after birth before leaving the hospital. All women gave birth during the study period between March 1, 2015, and July 31, 2015. Data regarding vaccination and influenza infection in or after October 2014, age, previous experience of childbirth, and number and ages of cohabitants were collected. Seventy-eight percent (n = 51,97) of women given questionnaires responded. Of these, 2,661 (51 %) and 364 (7.0 %) women reported having been vaccinated and having contracted influenza respectively. Multiparous women had a higher risk of influenza regardless of vaccination status (8.9 % [121/1362] vs 5.7 % [74/1299], relative risk [95 % confidence interval], 1.80 [1.36 to 2.38] for vaccinated and 9.3 % [112/1198] vs 4.3 % [57/1328], 2.18 [1.60 to 2.97] for unvaccinated women) compared to primiparous women. The risk of influenza increased with increasing number of cohabitants: 4.8 % (100/2089), 7.5 %, (121/1618), 9.0 %, (71/785), and 10.4 % (58/557) for women with 1, 2, 3, and ≥4 cohabitants respectively. Family size is a risk factor for influenza infection in pregnancy.


Subject(s)
Influenza, Human/epidemiology , Pregnancy Complications, Infectious/epidemiology , Adolescent , Adult , Asian People , Child , Child, Preschool , Female , Humans , Infant , Japan/epidemiology , Middle Aged , Pregnancy , Risk Factors , Surveys and Questionnaires , Young Adult
11.
Epidemiol Infect ; 142(11): 2237-47, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25078437

ABSTRACT

Consumption of seafood contaminated with Vibrio parahaemolyticus causes foodborne infections, which are on the rise owing to increased consumption of raw seafood in Asia, Europe, North America, and other regions. V. parahaemolyticus infections have been common in Japan since the 1960s. Following an epidemic in 1997, the Japanese Ministry of Health, Labour, and Welfare instituted regulations for seafood in 1999, which appear to be reducing V. parahaemolyticus infections. In this review, we describe the scientific findings for these regulations. Analyses of the V. parahaemolyticus serotypes and isolate characteristics in samples from infected patients and contaminated seafood are discussed. In addition, based on the results of a survey, we show that new food safety regulations have led to improvements in food hygiene at many seafood retail shops, food service facilities, and restaurants. This example from Japan could be of immense help to control foodborne infections in other countries.


Subject(s)
Food Contamination/legislation & jurisprudence , Food Safety , Vibrio Infections/prevention & control , Vibrio parahaemolyticus/pathogenicity , Female , Food Contamination/prevention & control , Humans , Japan , Male , Seafood/adverse effects , Seafood/analysis , Vibrio Infections/epidemiology
12.
J Oral Rehabil ; 41(3): 170-6, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24447128

ABSTRACT

The aims of this study were to introduce a novel electronic system for reliable evaluation of the non-functional tooth contact in patients with temporomandibular disorders (TMDs) and investigate the possible associations between the non-functional tooth contact and some characteristics of the patients with TMD. We designed and installed a software program to send emails regarding the non-functional tooth contact to the subjects' preregistered cellular phones at intervals of 20 ± 9 min daily for 10 consecutive days. Twelve patients with TMD and 12 gender- and age-matched healthy subjects responded via emails to one of 3 choices: no tooth contact, tooth contact during oral functions or tooth contact not associated with oral functions. The influence of subjective stress, anxiety, depression, personality and daily activities on tooth contact was then assessed. The frequency of the non-functional tooth contact was significantly higher in the patients with TMD than in the healthy subjects (35·0% vs. 9·6%, P < 0·001), while no significant group difference was found for the frequency of functional tooth contact, the stress, anxiety, depression and personality.


Subject(s)
Bruxism/epidemiology , Temporomandibular Joint Disorders/epidemiology , Adult , Anxiety/epidemiology , Bruxism/complications , Case-Control Studies , Cell Phone , Depression/epidemiology , Electronic Mail , Female , Humans , Male , Personality , Software , Stress, Psychological/epidemiology , Temporomandibular Joint Disorders/complications , Young Adult
13.
Br J Cancer ; 109(8): 2248-58, 2013 Oct 15.
Article in English | MEDLINE | ID: mdl-24045665

ABSTRACT

BACKGROUND: Epithelial-mesenchymal transition (EMT) is a crucial process in cancer progression that provides cancer cells with the ability to escape from the primary focus, invade stromal tissues and migrate to distant regions. Cell lines that lack E-cadherin show increased tumorigenesis and metastasis, and the expression levels of E-cadherin and Snail correlate inversely with the prognosis of patients suffering from breast cancer or oral squamous cell carcinoma (OSCC). Moreover, recent studies have shown that most EMT cases are regulated by soluble growth factors or cytokines. Among these factors, fibroblast growth factors (FGFs) execute diverse functions by binding to and activating members of the FGF receptor (FGFR) family, including FGFR1-4. Fibroblast growth factor receptor 1 is an oncoprotein that is involved in tumorigenesis, and PD173074 is known to be a selective inhibitor of FGFR1. However, the roles of FGFR1 and FGFR1 inhibitors have not yet been examined in detail. METHODS: Here, we investigated the expression of FGFR1 in head and neck squamous cell carcinoma (HNSCC) and the role of the FGFR1 inhibitor PD173074 in carcinogenesis and the EMT process. RESULTS: Fibroblast growth factor receptor 1 was highly expressed in 54% of HNSCC cases and was significantly correlated with malignant behaviours. Nuclear FGFR1 expression was also observed and correlated well with histological differentiation, the pattern of invasion and abundant nuclear polymorphism. Fibroblast growth factor receptor 1 was also overexpressed in EMT cell lines compared with non-EMT cell lines. Furthermore, treatment of HOC313 cells with PD173074 suppressed cellular proliferation and invasion and reduced ERK1/2 and p38 activation. These cells also demonstrated morphological changes, transforming from spindle- to cobble stone-like in shape. In addition, the expression levels of certain matrix metalloproteinases (MMPs), whose genes contain activator protein-1 (AP-1) promoter sites, as well as Snail1 and Snail2 were reduced following PD173074 treatment. CONCLUSION: Taken together, these data suggest that PD173074 inhibits the MAPK pathway, which regulates the activity of AP-1 and induces MET. Furthermore, this induction of MET likely suppresses cancer cell growth and invasion.


Subject(s)
Carcinoma, Squamous Cell/drug therapy , Epithelial-Mesenchymal Transition/drug effects , Head and Neck Neoplasms/drug therapy , Pyrimidines/pharmacology , Receptor, Fibroblast Growth Factor, Type 1/antagonists & inhibitors , Receptor, Fibroblast Growth Factor, Type 1/biosynthesis , Transcription Factor AP-1/metabolism , Carcinoma, Squamous Cell/enzymology , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Cell Growth Processes/drug effects , Cell Line, Tumor , Cell Nucleus/metabolism , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Head and Neck Neoplasms/enzymology , Head and Neck Neoplasms/metabolism , Head and Neck Neoplasms/pathology , Humans , Immunohistochemistry , Mitogen-Activated Protein Kinases/metabolism , Neoplasm Invasiveness , Proto-Oncogene Proteins c-met/biosynthesis , Squamous Cell Carcinoma of Head and Neck , Transcription Factor AP-1/biosynthesis
14.
J Phys Condens Matter ; 35(42)2023 Jul 21.
Article in English | MEDLINE | ID: mdl-37429290

ABSTRACT

Linearly polarized soft x-rays provide information about electronic or magnetic anisotropy through absorption into materials or generation of photoelectrons. In order to change the relative angle between linear polarization and sample crystalline axes, either x-ray polarization or the sample needs to be rotated. Due to difficulties of polarization control in the soft x-ray range, a conventional approach was to rotate the sample. However, this method is not compatible, for example, withoperandomeasurements on non-uniform samples where sample size and rotational motion are severely restricted. At BL07LSU of SPring-8, we developed a new method to rotate the linear polarization angle using a segmented cross undulator. We report an application of this linear polarization rotation to resonant photoemission spectroscopy on an magnetic atomic layer Fe2N on Cu(111) to probe the electronic anisotropy of the 3dstates in the vicinity of the Fermi level.

15.
Oral Dis ; 18(8): 756-62, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22642601

ABSTRACT

OBJECTIVES: An odontoma, which shows proliferating odontogenic epithelium and mesenchymal tissue, is one of the most common odontogenic tumors encountered. These are commonly found in tooth-bearing regions, although the etiology remains unknown. There are no previous reports of an established line of immortalized human odontoma cells. METHODS: Using odontoma fragments obtained from a girl treated at our department, we established an immortalized human odontoma cell line and investigated cell morphology, dynamic proliferation, the presence of contamination, and karyotype. Moreover, cell characterization was examined using osteogenic and odontogenic markers. RESULTS: We successfully established a mesenchymal odontoma cell (mOd cells). The cells were found to be fibroblastic and had a high level of telomerase activity. Cell growth was confirmed after more than 200 population doublings without significant growth retardation. mOd cells expressed mRNA for differentiation markers, including collagen type I (COLI), alkaline phosphatase, bone sialoprotein, osteopontin, osteocalcin, cementum-derived protein (CP-23), dentin sialophosphoprotein (DSPP), and distal-less homeobox 3 (DLX3), as well as bone morphogenetic proteins (BMPs). In addition, they showed a high level of calcified nodule formation activity in vitro. CONCLUSIONS: We successfully established a cell line that may be useful for investigating the mechanisms of normal odontogenesis as well as characteristics of odontoma tumors.


Subject(s)
Cell Line, Tumor , Mesoderm/pathology , Odontoma/pathology , Adolescent , Adult , Aged , Alkaline Phosphatase/analysis , Biomarkers/analysis , Bone Morphogenetic Proteins/analysis , Calcification, Physiologic/physiology , Cell Culture Techniques , Cell Proliferation , Cell Shape , Child , Child, Preschool , Collagen Type I/analysis , Extracellular Matrix Proteins/analysis , Female , Fibroblasts/pathology , Homeodomain Proteins/analysis , Humans , Integrin-Binding Sialoprotein/analysis , Karyotype , Middle Aged , Odontoma/genetics , Osteocalcin/analysis , Osteopontin/analysis , Phosphoproteins/analysis , Proteins/analysis , Sialoglycoproteins/analysis , Telomerase/analysis , Transcription Factors/analysis , Young Adult
16.
Epidemiol Infect ; 139(10): 1505-10, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21205441

ABSTRACT

Intake of a small dose of foodborne pathogens can cause infection. In this study, an estimation of the infectious dose of the pathogens was obtained by conducting microbiological risk assessments. The contamination levels of foodborne pathogens were analysed in 17 outbreaks of Salmonella, Escherichia coli O157, enterotoxigenic E. coli, Vibrio parahaemolyticus, and Campylobacter jejuni occurring in Japan between 2004 and 2006. The infectious dose was estimated in 14 of the 17 outbreaks utilizing existing data. In three outbreaks of Salmonella infection in which the infection rate was 89-100%, the dose of the ingested pathogens was estimated to be 259,000-14,000,000,000 c.f.u. In other outbreaks of Salmonella infection, the infection rate and dose of the ingested pathogens were 10-66·4% and 81-1560 c.f.u. or most probable number (MPN), respectively. The ingested Salmonella dose is likely to be related to the infection rate; however, storage conditions should be taken into account when making this determination. In an outbreak of E. coli O157 infection, the infection rate and ingestion dose were 100% and 2 to <9 c.f.u., respectively, while in an outbreak of enterotoxigenic E. coli infection, they were 93% and 25-1000 c.f.u., respectively. Finally, in an outbreak of C. jejuni infection, the infection rate and ingestion dose were 37·5% and 360 MPN, respectively. These results will be particularly valuable for risk assessment.


Subject(s)
Bacteria/pathogenicity , Bacterial Infections/microbiology , Disease Outbreaks , Foodborne Diseases/microbiology , Gastroenteritis/microbiology , Bacterial Load , Eating , Humans , Japan
17.
J Appl Microbiol ; 110(1): 209-17, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21029276

ABSTRACT

AIMS: To develop a quick and accurate PCR-based method to evaluate viable Bifidobacterium breve strain Yakult (BbrY) in human faeces. METHODS AND RESULTS: The number of BbrY in faeces was detected by using strain-specific quantitative real-time PCR (qPCR) derived from a randomly amplified polymorphic DNA analysis. And using propidium monoazide (PMA) treatment, which combined a DNA-intercalating dye for covalently linking DNA in dead cells and photoactivation, only viable BbrY in the faeces highly and significantly correlated with the number of viable BbrY added to faecal samples within the range of 10(5) -10(9) cells per g of faeces was enumerated. After 11 healthy subjects ingested 10·7 log CFU of BbrY daily for 10 days, 6·9 (± 1·5) log CFU g(-1) [mean (± SD)] of BbrY was detected in faeces by using strain-specific transgalactosylated oligosaccharide-carbenicillin (T-CBPC) selective agar medium. Viable BbrY detected by qPCR with PMA treatment was 7·5 (± 1·0) log cells per g and the total number (viable and dead) of BbrY detected by qPCR without PMA treatment was 8·1 (± 0·8) log cells per g. CONCLUSIONS: Strain-specific qPCR with PMA treatment evaluated viable BbrY in faeces quickly and accurately. SIGNIFICANCE AND IMPACT OF THE STUDY: Combination of strain-specific qPCR and PMA treatment is useful for evaluating viable probiotics and its availability in humans.


Subject(s)
Azides , Bifidobacterium/isolation & purification , Feces/microbiology , Intercalating Agents , Propidium/analogs & derivatives , Bifidobacterium/genetics , DNA Primers/chemistry , Humans , Microbial Viability , Polymerase Chain Reaction/methods , Probiotics , Random Amplified Polymorphic DNA Technique , Species Specificity
18.
Reprod Domest Anim ; 46(2): 189-96, 2011 Apr.
Article in English | MEDLINE | ID: mdl-20412512

ABSTRACT

Miniature pigs share many similar characteristics such as anatomy, physiology and body size with humans and are expected to become important animal models for therapeutic cloning using embryonic stem cells (ESCs) derived by somatic cell nuclear transfer (SCNT). In the present study, we observed that miniature pig SCNT blastocysts possessed a lower total number of nuclei and a lower percentage of POU5F1-positive cells than those possessed by in vitro fertilized (IVF) blastocysts. To overcome these problems, we evaluated the applicability of aggregating miniature pig SCNT embryos at the four-cell stage. We showed that (i) aggregation of two or three miniature pig SCNT embryos at the four-cell stage improves the total number of nuclei and the percentage of POU5F1-positive cells in blastocysts, and (ii) IVF blastocysts with low cell numbers induced by the removal of two blastomeres at the four-cell stage did not exhibit a decrease in the percentage of POU5F1-positive cells. These results suggest that the aggregation of miniature pig SCNT embryos at the four-cell stage can be a useful technique for improving the quality of miniature pig SCNT blastocysts and indicating that improvement in the percentage of POU5F1-positive cells in aggregated SCNT embryos is not simply the consequence of increased cell numbers.


Subject(s)
Blastocyst/physiology , Cloning, Organism/veterinary , Embryo Culture Techniques/veterinary , Nuclear Transfer Techniques/veterinary , Swine, Miniature/embryology , Animals , Cloning, Organism/methods , Embryo Culture Techniques/methods , Embryo Transfer/methods , Embryo Transfer/veterinary , Female , Fertilization in Vitro/veterinary , Pregnancy , Swine
19.
J Food Prot ; 73(6): 1077-84, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20537263

ABSTRACT

To identify a rapid method for extracting a large amount of DNA from fungi associated with food hygiene, extraction methods were compared using fungal pellets formed rapidly in liquid media. Combinations of physical and chemical methods or commercial kits were evaluated with 3 species of yeast, 10 species of ascomycetous molds, and 4 species of zygomycetous molds. Bead grinding was the physical method, followed by chemical methods involving sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), and benzyl chloride and two commercial kits. Quantity was calculated by UV absorbance at 260 nm, quality was determined by the ratio of UV absorbance at 260 and 280 nm, and gene amplifications and electrophoresis profiles of whole genomes were analyzed. Bead grinding with the SDS method was the most effective for DNA extraction for yeasts and ascomycetous molds, and bead grinding with the CTAB method was most effective with zygomycetous molds. For both groups of molds, bead grinding with the CTAB method was the best approach for DNA extraction. Because this combination also is relatively effective for yeasts, it can be used to extract a large amount of DNA from a wide range of fungi. The DNA extraction methods are useful for developing gene indexes to identify fungi with molecular techniques, such as DNA fingerprinting.


Subject(s)
Colony Count, Microbial/methods , DNA, Fungal/isolation & purification , Food Microbiology , Fungi/isolation & purification , Yeasts/isolation & purification , Consumer Product Safety , DNA, Fungal/analysis , Food Contamination/analysis , Fungi/genetics , Gene Amplification , Humans , Time Factors , Yeasts/genetics
20.
J Food Prot ; 73(8): 1537-42, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20819369

ABSTRACT

In recent years, bottled mineral water has undergone inactivation by methods other than the traditional heat treatment during the production process; there are fewer reports of the effectiveness of these inactivation methods on yeasts and molds in mineral water than on bacteria and protozoan oocysts. In this study, we evaluated the effects of UV irradiation and ozone treatment compared with heat treatment at 85 degrees C on yeast cells and mold spores inoculated into mineral water. A 5-log reduction occurred at a UV radiation dose of 31,433 microJ/cm2 for Saccharomyces cerevisiae and at 588,285 microJ/cm2 for Penicillium pinophilum. The treatment time for 5-log reduction estimated for UV irradiation was about 0.6 min for S. cerevisiae and about 10.7 min for P. pinophilum; at an ozone concentration of 0.1 ppm, it was 1.75 min for S. cerevisiae and 2.70 min for P. pinophilum, and at a concentration of 0.6 ppm, it was 0.32 min for S. cerevisiae and 0.57 min for P. pinophilum. Comparison of the inactivation effects among the three methods showed that UV irradiation and ozone treatment were less effective than heat treatment at 85 degrees C. Thus, when UV irradiation and ozone treatment are used for inactivation of mineral water, it seems that they need to be combined with heat treatment to achieve a definite effect. Yeast cells are more sensitive to all three inactivation methods than are mold spores, and the sensitivity of yeast cells and mold spores to these inactivation methods may vary among genera.


Subject(s)
Food Irradiation , Fungi/radiation effects , Oxidants, Photochemical/pharmacology , Ozone/pharmacology , Water Microbiology , Yeasts/radiation effects , Colony Count, Microbial , Consumer Product Safety , Dose-Response Relationship, Drug , Dose-Response Relationship, Radiation , Fungi/drug effects , Fungi/growth & development , Hot Temperature , Humans , Time Factors , Ultraviolet Rays , Yeasts/drug effects , Yeasts/growth & development
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