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1.
BMC Musculoskelet Disord ; 25(1): 42, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195509

RESUMO

BACKGROUND: Mutations of the COL2A1 gene have been identified in patients with Perthes' disease. Several studies have hypothesised a connection between Perthes' disease and collagen synthesis disorders, especially COL2A1-related disorders, but no large studies on the subject have been made. The aim of this study was thus to discover if there is a connection between patients presenting with Perthes' disease, and collagen synthesis disorders. A secondary aim was to see if the children with both disorders had less optimal birth characteristics than the rest. METHODS: Swedish national registers were used to collect data on children diagnosed with Perthes' disease or a collagen synthesis disorder. These registers include all births in Sweden, and data from both outpatient and in-hospital visits. A wide range of data is included besides diagnoses. All children with follow-up data to the age of 15 years were included. Pearson's chi-square was used for analysis. Statistical significance was further analysed with Fisher's Exact Test. RESULTS: In total, 3488 children with either diagnosis were included. 1620 children had only Perthes disease, while 1808 children had only a collagen synthesis disorder. Five children were found to have both the diagnosis Perthes' disease and a collagen synthesis disorder. One child was large for their gestational age and none of the children had a low birthweight. Two of the children were moderately preterm. CONCLUSIONS: The distinct lack of overlap in such a large body of material raises doubt about a connection between the presentation of Perthes' disease and collagen synthesis disorders, either COL2A1-related or not. We could not find an overrepresentation of less optimal birth characteristics either.


Assuntos
Doença de Legg-Calve-Perthes , Criança , Recém-Nascido , Humanos , Adolescente , Doença de Legg-Calve-Perthes/epidemiologia , Doença de Legg-Calve-Perthes/genética , Suécia/epidemiologia , Emoções , Idade Gestacional , Colágeno
2.
Epidemiol Psychiatr Sci ; 32: e39, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37303201

RESUMO

AIM: Research on the effect of oral contraceptive (OC) use on the risk of depression shows inconsistent findings, especially in adult OC users. One possible reason for this inconsistency is the omission of women who discontinue OCs due to adverse mood effects, leading to healthy user bias. To address this issue, we aim to estimate the risk of depression that is associated with the initiation of OCs as well as the effect of OC use on lifetime risk of depression. METHODS: This is a population-based cohort study based on data from 264,557 women from the UK Biobank. Incidence of depression was addressed via interviews, inpatient hospital or primary care data. The hazard ratio (HR) between OC use and incident depression was estimated by multivariable Cox regression with OC use as a time-varying exposure. To validate causality, we examined familial confounding in 7,354 sibling pairs. RESULTS: We observed that the first 2 years of OC use were associated with a higher rate of depression compared to never users (HR = 1.71, 95% confidence interval [CI]: 1.55-1.88). Although the risk was not as pronounced beyond the first 2 years, ever OC use was still associated with an increased lifetime risk of depression (HR = 1.05, 95% CI: 1.01-1.09). Previous OC use were associated with a higher rate of depression compared to never users, with adolescent OC users driving the increased hazard (HR = 1.18, 95% CI: 1.12-1.25). No significant association were observed among adult OC users who had previously used OCs (HR = 1.00, 95% CI: 0.95-1.04). Notably, the sibling analysis provided further evidence for a causal effect of OC use on the risk of depression. CONCLUSIONS: Our findings suggest that the use of OCs, particularly during the first 2 years, increases the risk of depression. Additionally, OC use during adolescence might increase the risk of depression later in life. Our results are consistent with a causal relationship between OC use and depression, as supported by the sibling analysis. This study highlights the importance of considering the healthy user bias as well as family-level confounding in studies of OC use and mental health outcomes. Physicians and patients should be aware of this potential risk when considering OCs, and individualized risk-benefit assessments should be conducted.


Assuntos
Depressão , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Adolescente , Adulto , Humanos , Feminino , Estudos de Coortes , Depressão/epidemiologia , Cognição , Anticoncepcionais Orais/efeitos adversos
3.
Phys Rev Lett ; 121(5): 052001, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118290

RESUMO

Exclusive measurements of the quasifree pp→ppπ^{+}π^{-} reaction have been carried out at WASA@COSY by means of pd collisions at T_{p}=1.2 GeV. Total and differential cross sections have been extracted covering the energy region T_{p}=1.08-1.36 GeV, which is the region of N^{*}(1440) and Δ(1232)Δ(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor ΔN dibaryon resonance with I(J^{P})=2(1^{+}) produced associatedly with a pion is able to overcome these deficiencies.

4.
Phys Rev Lett ; 120(2): 022002, 2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29376676

RESUMO

Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high polarization degree of the proton beam of COSY, the reaction p[over →]p→ppη has been measured close to threshold to explore the analyzing power A_{y}. The angular distribution of A_{y} is determined with the precision improved by more than 1 order of magnitude with respect to previous results, allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q=15 MeV, signaling s-wave production with no evidence for higher partial waves. At Q=72 MeV the data reveal strong interference of Ps and Pp partial waves and cancellation of (Pp)^{2} and Ss^{*}Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the η meson.

5.
Mycorrhiza ; 27(4): 383-396, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28066872

RESUMO

Hydrophobins are small secreted proteins that are present as several gene copies in most fungal genomes. Their properties are now well understood: they are amphiphilic and assemble at hydrophilic/hydrophobic interfaces. However, their physiological functions remain largely unexplored, especially within mycorrhizal fungi. In this study, we identified hydrophobin genes and analysed their distribution in eight mycorrhizal genomes. We then measured their expression levels in three different biological conditions (mycorrhizal tissue vs. free-living mycelium, organic vs. mineral growth medium and aerial vs. submerged growth). Results confirmed that the size of the hydrophobin repertoire increased in the terminal orders of the fungal evolutionary tree. Reconciliation analysis predicted that in 41% of the cases, hydrophobins evolved from duplication events. Whatever the treatment and the fungal species, the pattern of expression of hydrophobins followed a reciprocal function, with one gene much more expressed than others from the same repertoire. These most-expressed hydrophobin genes were also among the most expressed of the whole genome, which suggests that they play a role as structural proteins. The fine-tuning of the expression of hydrophobin genes in each condition appeared complex because it differed considerably between species, in a way that could not be explained by simple ecological traits. Hydrophobin gene regulation in mycorrhizal tissue as compared with free-living mycelium, however, was significantly associated with a calculated high exposure of hydrophilic residues.


Assuntos
Proteínas Fúngicas/genética , Duplicação Gênica , Genoma Fúngico , Micorrizas/genética , Genômica , Micélio
6.
J Food Prot ; 79(4): 677-81, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27052875

RESUMO

The prevalence of human pathogenic Yersinia enterocolitica was determined in tonsil and intestinal content samples from 388 healthy fattening pigs at the four biggest Finnish slaughterhouses. These slaughterhouses process 73% of pigs in Finland. Tonsil samples were tested by PCR targeted for yadA, and intestinal samples were cultured. All pathogenic Y. enterocolitica isolates represented bioserotype 4/O:3. The prevalence of Y. enterocolitica in tonsil samples was 60% (95% confidence limit, 55.4 to 65.1%), and its prevalence in intestinal samples was 26% (95% confidence limit, 22.1 to 31.2%). The prevalence of Y. enterocolitica in tonsil and intestinal samples varied between the four slaughterhouses. The tonsil prevalence of Y. enterocolitica was higher in slaughterhouse B, and the prevalence in intestinal content was higher in slaughterhouse C. There were more positive results in both tonsil and intestinal samples in pigs coming from fattening farms than in pigs coming from farrowing-and-fattening farms. A seasonal variation was observed in the prevalence of Y. enterocolitica in intestinal samples, with the highest prevalence during July and August, but no seasonal variation was detected in tonsil samples.


Assuntos
Carne/microbiologia , Doenças dos Suínos/microbiologia , Yersiniose/microbiologia , Yersinia enterocolitica/isolamento & purificação , Matadouros , Animais , Finlândia/epidemiologia , Humanos , Reação em Cadeia da Polimerase , Prevalência , Suínos , Doenças dos Suínos/epidemiologia , Yersiniose/epidemiologia , Yersinia enterocolitica/classificação , Yersinia enterocolitica/genética
7.
Phys Chem Chem Phys ; 16(27): 13718-25, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-24728264

RESUMO

We have prepared an yttrium modified Pt(111) single crystal under ultra-high vacuum conditions, simulating a bulk alloy. A Pt overlayer is formed upon annealing the crystal above 800 K. The annealed structure binds CO weaker than Pt(111), with a pronounced peak at 295 K in the temperature programmed desorption of CO. When depositing a large amount of yttrium at 1173 K, a (1.88 × 1.88)R30° structure relative to Pt(111) was observed by low energy electron diffraction. Such an electron diffraction pattern could correspond to a (2 × 2)R30° structure under 6% compressive strain. This structure is in agreement with the structure of the vacancies in a Pt Kagomé layer in Pt5Y rotated 30° with respect to the bulk of the Pt(111). The Pt overlayer is relatively stable in air; however, after performing oxygen reduction activity measurements in an electrochemical cell, a thick Pt overlayer was measured by the angle resolved X-ray photoelectron spectroscopy depth profile. The activity of the annealed Y/Pt(111) for the oxygen reduction reaction was similar to that of polycrystalline Pt3Y.

8.
Epidemiol Infect ; 142(11): 2261-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24476659

RESUMO

In 2010, a marked increase in listeriosis incidence was observed in Finland. Listeria monocytogenes PFGE profile 96 was responsible for one-fifth of the reported cases and a cluster of PFGE profile 62 was also detected. Investigations revealed two fishery production plants with persistent Listeria contamination. It appears likely that the plants were at least partly responsible for the increase of listeriosis. Epidemiological investigation revealed that 57% (31/54) of cases with underlying immunosuppressive condition or medication reported eating gravad or cold-smoked fish. Two public notices were issued by THL and Evira informing which groups were most at risk from the effects of listeriosis and should therefore be cautious in consuming certain products. Systematic sampling of foods and adequate epidemiological investigation methods are required to identify the sources of Listeria infections. Continuous control measures at fishery production plants producing risk products are essential.


Assuntos
Pesqueiros , Contaminação de Alimentos/estatística & dados numéricos , Listeria/classificação , Listeriose/epidemiologia , Animais , Surtos de Doenças , Feminino , Finlândia/epidemiologia , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Indústria de Processamento de Alimentos , Humanos , Incidência , Listeria/patogenicidade , Listeriose/diagnóstico , Masculino , Sistema de Registros , Medição de Risco
9.
Int J Dent Hyg ; 12(1): 48-54, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23730835

RESUMO

The immune response is influenced by genetic and epigenetic factors, as well as disease and environmental factors. The term 'epigenetics' describes changes in the genome that influence the gene expression without altering the DNA sequence. In contrast to genetic changes in the DNA, epigenetic changes are reversible and are influenced by environmental factors. The aim of this study is to review the literature on epigenetic modifications with respect to oral health and inflammatory conditions in the oral cavity and to discuss the potential use of this new research field for the dental hygienists' and/or dentists' clinical work. Relevant publications were identified using the PubMed database without limits. The searches were conducted during January to March 2012 and resulted in articles published between 1912 and 2012. Key factors such as environment, diet, smoking, bacteria and inflammation were identified to be relevant to oral health. The result of this review article shows that there is a void in the research on epigenetics in relation to oral health. Identification of epigenetic modifications correlating with oral health may not only present a link between the influence of genetics and that of the environment on oral diseases but also provide new treatment models and tools for the dental professionals.


Assuntos
Epigênese Genética/genética , Interação Gene-Ambiente , Doenças da Boca/genética , Saúde Bucal , Fenômenos Fisiológicos Bacterianos , Dieta , Meio Ambiente , Epigenômica , Gengivite/etiologia , Gengivite/genética , Humanos , Doenças da Boca/etiologia , Periodontite/etiologia , Periodontite/genética , Fumar
10.
ISME J ; 7(10): 2010-22, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23788332

RESUMO

The majority of nitrogen in forest soils is found in organic matter-protein complexes. Ectomycorrhizal fungi (EMF) are thought to have a key role in decomposing and mobilizing nitrogen from such complexes. However, little is known about the mechanisms governing these processes, how they are regulated by the carbon in the host plant and the availability of more easily available forms of nitrogen sources. Here we used spectroscopic analyses and transcriptome profiling to examine how the presence or absence of glucose and/or ammonium regulates decomposition of litter material and nitrogen mobilization by the ectomycorrhizal fungus Paxillus involutus. We found that the assimilation of nitrogen and the decomposition of the litter material are triggered by the addition of glucose. Glucose addition also resulted in upregulation of the expression of genes encoding enzymes involved in oxidative degradation of polysaccharides and polyphenols, peptidases, nitrogen transporters and enzymes in pathways of the nitrogen and carbon metabolism. In contrast, the addition of ammonium to organic matter had relatively minor effects on the expression of transcripts and the decomposition of litter material, occurring only when glucose was present. On the basis of spectroscopic analyses, three major types of chemical modifications of the litter material were observed, each correlated with the expression of specific sets of genes encoding extracellular enzymes. Our data suggest that the expression of the decomposition and nitrogen assimilation processes of EMF can be tightly regulated by the host carbon supply and that the availability of inorganic nitrogen as such has limited effects on saprotrophic activities.


Assuntos
Agaricales/metabolismo , Carbono/metabolismo , Regulação Fúngica da Expressão Gênica , Micorrizas/metabolismo , Nitrogênio/metabolismo , Plantas/microbiologia , Microbiologia do Solo , Agaricales/enzimologia , Agaricales/genética , Carbono/farmacologia , Enzimas/genética , Enzimas/metabolismo , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Micorrizas/enzimologia , Micorrizas/genética , Nitrogênio/farmacologia , Plantas/metabolismo , Solo/química , Espectroscopia de Infravermelho com Transformada de Fourier
11.
Br J Anaesth ; 110(6): 926-39, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23578861

RESUMO

Elective surgery is usually preceded by preoperative diagnostics to minimize risk. The results are assumed to elicit preventive measures or even cancellation of surgery. Moreover, physicians perform preoperative tests as a baseline to detect subsequent changes. This systematic review aims to explore whether preoperative testing leads to changes in management or reduces perioperative mortality or morbidity in unselected patients undergoing elective, non-cardiac surgery. We systematically searched all relevant databases from January 2001 to February 2011 for studies investigating the relationship between preoperative diagnostics and perioperative outcome. Our methodology was based on the manual of the Ludwig Boltzmann Institute for Health Technology Assessment, the Scottish Intercollegiate Guidelines Network (SIGN) handbook, and the PRISMA statement for reporting systematic reviews. One hundred and one of the 25 281 publications retrieved met our inclusion criteria. Three test grid studies used a randomized controlled design and 98 studies used an observational design. The test grid studies show that in cataract surgery and ambulatory surgery, there are no significant differences between patients with indicated preoperative testing and no testing regarding perioperative outcome. The observational studies do not provide valid evidence that preoperative testing is beneficial in healthy adults undergoing non-cardiac surgery. There is no evidence derived from high-quality studies that supports routine preoperative testing in healthy adults undergoing non-cardiac surgery. Testing according to pathological findings in a patient's medical history or physical examination seems justified, although the evidence is scarce. High-quality studies, especially large randomized controlled trials, are needed to explore the effectiveness of indicated preoperative testing.


Assuntos
Procedimentos Cirúrgicos Eletivos , Cuidados Pré-Operatórios , Proteína C-Reativa/análise , Hematócrito , Hemoglobinas/análise , Humanos , Testes de Função Renal , Contagem de Leucócitos , Testes de Função Hepática , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
Epidemiol Infect ; 141(8): 1640-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23068603

RESUMO

In 2010, 7/44 (16%) reported foodborne outbreaks in Finland were linked with raw beetroot consumption. We reviewed data from the national outbreak registry in order to hypothesize the aetiology of illness and to prevent further outbreaks. In the seven outbreaks, 124 cases among 623 respondents were identified. Consumption of raw beetroot was strongly associated with gastrointestinal illness (relative risk 8∙99, 95% confidence interval 6∙06-13∙35). The illness was characterized by sudden onset of gastrointestinal symptoms; the median incubation time was 40 min and duration of illness 5 h. No common foodborne pathogens or toxins were found in either clinical or beetroot samples, but all tested beetroot samples were of poor quality according to total bacterial counts. Beta-haemolytic Pseudomonas fluorescens was detected in several beetroot samples but its effect on human health is unknown. No outbreaks were reported after the Finnish Food Safety Authority Evira advised against serving raw beetroot in institutional canteens.


Assuntos
Beta vulgaris/intoxicação , Surtos de Doenças , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Gastroenterite/epidemiologia , Adolescente , Adulto , Idoso , Beta vulgaris/microbiologia , Estudos de Coortes , Feminino , Finlândia/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Gastroenterite/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estações do Ano , Adulto Jovem
13.
Zoonoses Public Health ; 58(8): 589-96, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21824360

RESUMO

Salmonella enterica serotype Bovismorbificans is a rare serotype in Finland. In June 2009, a nationwide outbreak of S. Bovismorbificans infections occurred, and 42 clinical isolates were identified. We conducted a case-control study enrolling 28 cases and 48 matched controls, and found ready-to-eat alfalfa sprouts associated with the infection (odds ratio = 35.2, 95% confidence interval 2.8-435). The sprouts were traced back to a domestic producer, with the seeds originating in Italy. Although finding microbiological evidence for sprouts as a source of this outbreak was very challenging, S. Bovismorbificans was finally found in sprouts germinated in the laboratory, and in soaking and rinse waters during the germination process. The pulsed field gel electrophoresis showed that these isolates were identical to the human outbreak isolates. Before sampling, it is important to mix the seeds well and to take several large-size samples from different seed lots. Instead of analysing seeds, the analysis should be targeted to soaking or rinse water samples and to the sprouts germinated in a laboratory. Accordingly, the sprout producers should only buy seeds that have been analysed for Salmonella. The producers have to include Salmonella testing in their internal quality control to ensure that Salmonella is absent from sprouts placed on the market during their shelf-life. In order to reduce the health hazard caused by sprouts, an effective and safe decontamination procedure should also be developed for the seeds.


Assuntos
Contaminação de Alimentos , Microbiologia de Alimentos , Medicago sativa/microbiologia , Intoxicação Alimentar por Salmonella/epidemiologia , Sementes/microbiologia , Estudos de Casos e Controles , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Finlândia/epidemiologia , Genótipo , Humanos , Entrevistas como Assunto , Modelos Logísticos , Fatores de Risco , Intoxicação Alimentar por Salmonella/transmissão , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Sorotipagem
14.
Phys Rev Lett ; 106(24): 242302, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21770567

RESUMO

We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn→dπ(0)π(0) over the full energy region of the ABC effect, a pronounced low-mass enhancement in the ππ-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t-channel ΔΔ process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m=2.37 GeV, Γ≈70 MeV and I(J(P))=0(3(+)) in both pn and ΔΔ systems. Necessary further tests of the resonance interpretation are discussed.

15.
J Appl Microbiol ; 108(3): 956-964, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19735331

RESUMO

AIMS: The aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic Yersinia enterocolitica from pig intestinal content. METHODS AND RESULTS: The four methods comprised of 15 isolation steps using selective enrichments (irgasan-ticarcillin-potassium chlorate and modified Rappaport broth) and mildly selective enrichments at 4 or 25 degrees C. Salmonella-Shigella-desoxycholate-calcium chloride agar, cefsulodin-irgasan-novobiocin agar were used as plating media. The most sensitive method detected 78% (53/68) of the positive samples. Individual isolation steps using cold enrichment as the only enrichment or as a pre-enrichment step with further selective enrichment showed the highest sensitivities (55-66%). All isolation methods resulted in high numbers of suspected colonies not confirmed as pathogenic Y. enterocolitica. CONCLUSIONS: Cold enrichment should be used in the detection of pathogenic Y. enterocolitica from pig intestinal contents. In addition, more than one parallel isolation step is needed. SIGNIFICANCE AND IMPACT OF THE STUDY: The study shows that depending on the isolation method used for Y. enterocolitica, the detected prevalence of Y. enterocolitica in pig intestinal contents varies greatly. More selective and sensitive isolation methods need to be developed for pathogenic Y. enterocolitica.


Assuntos
Contagem de Colônia Microbiana/métodos , Intestinos/microbiologia , Suínos/microbiologia , Yersinia enterocolitica/isolamento & purificação , Animais , Meios de Cultura , Dados de Sequência Molecular , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Sorotipagem , Doenças dos Suínos/microbiologia , Yersinia enterocolitica/classificação
16.
Phys Rev Lett ; 102(22): 225004, 2009 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-19658872

RESUMO

Observations of electron phase-space holes (EHs) in Earth's plasma sheet by the THEMIS satellites include the first detection of a magnetic perturbation (deltaB_{ parallel}) parallel to the ambient magnetic field (B0). EHs with a detectable deltaB_{ parallel} have several distinguishing features including large electric field amplitudes, a magnetic perturbation perpendicular to B0, high speeds ( approximately 0.3c) along B0, and sizes along B0 of tens of Debye lengths. These EHs have a significant center potential (Phi approximately k_{B}T_{e}/e), suggesting strongly nonlinear behavior nearby such as double layers or magnetic reconnection.

17.
Phys Rev Lett ; 102(15): 155002, 2009 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-19518640

RESUMO

We report the first direct observations of parallel electric fields (E_{ parallel}) carried by double layers (DLs) in the plasma sheet of Earth's magnetosphere. The DL observations, made by the THEMIS spacecraft, have E_{ parallel} signals that are analogous to those reported in the auroral region. DLs are observed during bursty bulk flow events, in the current sheet, and in plasma sheet boundary layer, all during periods of strong magnetic fluctuations. These observations imply that DLs are a universal process and that strongly nonlinear and kinetic behavior is intrinsic to Earth's plasma sheet.

19.
Phys Rev Lett ; 102(5): 052301, 2009 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-19257507

RESUMO

The ABC effect-a puzzling low-mass enhancement in the pipi invariant mass spectrum, first observed by Abashian, Booth, and Crowe-is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn-->dpi;{0}pi;{0} at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (pipi)_{I=L=0} channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a DeltaDelta system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data.

20.
J Appl Microbiol ; 106(6): 1976-85, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19228254

RESUMO

AIM: To screen and characterize toxic, heat-stable substances produced by food borne strains from Bacillus subtilis group. METHODS AND RESULTS: Using the boar sperm motility inhibition assay, six isolates from two outbreaks, out of the 94 isolates from 26 foods, were found to produce ethanol-soluble heat-stable substances that were toxic to sperm cells by depleting the mitochondrial membrane potentials. The toxic isolates were identified as Bacillus subtilis and B mojavensis. Colon carcinoma cells (Caco-2) were used to model the contact with the human digestive tract. The extract of B. subtilis F 2564/96 depolarized the mitochondria in intact Caco-2 cells similarly as in sperm cells. The substance responsible for these effects was purified using HPLC and identified by electron spray ionization ion trap mass spectrometry analysis as amylosin. The temperature requirement for amylosin production was 21-37 degrees C for B. subtilis and 11-21 degrees C for B. mojavensis. Both species produced amylosin in air as well as in 7-8% CO(2) with 8-9% O(2). CONCLUSIONS: Food borne illness related strains of B. subtilis and B. mojavensis, produced the heat-stable toxin amylosin. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report that suggests a role for the heat-stable, ion-channel forming toxin amylosin, as a virulence factor in food borne Bacillus.


Assuntos
Bacillus/metabolismo , Toxinas Bacterianas/metabolismo , Enterotoxinas/genética , Leite/microbiologia , Microbiologia do Solo , Animais , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus subtilis/genética , Bacillus subtilis/isolamento & purificação , Bacillus subtilis/metabolismo , Proteínas de Bactérias/genética , Toxinas Bacterianas/toxicidade , Células CACO-2/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , DNA Bacteriano/análise , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Enterotoxinas/isolamento & purificação , Enterotoxinas/toxicidade , Doenças Transmitidas por Alimentos/microbiologia , Proteínas de Choque Térmico/genética , Humanos , Masculino , RNA Ribossômico 16S/genética , Proteínas de Ligação a RNA/genética , Espermatozoides/efeitos dos fármacos , Suínos , Temperatura
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