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1.
Phys Rev Lett ; 124(25): 252501, 2020 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-32639790

RESUMEN

Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at sqrt[s]=510 GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction x_{F} and transverse momentum p_{T} have been observed at low transverse momentum p_{T}<1 GeV/c for the first time, at this collision energy. The asymmetries show an approximate x_{F} scaling in the p_{T} region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.

2.
Science ; 368(6490): 506-509, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32355026

RESUMEN

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π0 into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process. The differential cross sections for π0 photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding [Formula: see text], where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of [Formula: see text] Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.

3.
Lupus ; 27(2): 225-234, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28659045

RESUMEN

The objective of this study is to identify the effects of statins and risk factors for thrombosis in patients with new onset of systemic lupus erythematosus (SLE) with or without antiphospholipid antibodies (aPL). Consecutive patients with SLE without history of thrombotic events were retrospectively enrolled from April 1997 to February 2014. The development of first thrombosis and death caused by thrombosis were defined as the study endpoint. Risk and protective factors for developing thrombosis were analyzed. A total of 152 patients, 80 positive and 72 negative for aPL, were included. In aPL-positive patients, 15 developed arterial ( n = 6) and venous ( n = 9) thrombosis (median follow-up period 69 months). Cox's proportional hazards model showed that older age at SLE onset and IgG-anticardiolipin antibodies (aCL) were statistically significant risks for thrombosis. Statin therapy was identified as a statistically significant protective factor against thrombosis (hazard ratio 0.12, 95% confidence interval 0.01-0.98). In aPL-negative patients (median follow-up period 46 months), seven patients developed thrombosis (five arterial and two venous). No risk factors for thrombosis were found in this group. In aPL-positive patients with SLE, the late disease onset and the presence of IgG-aCL represented additional risk factors for thrombosis. Statin treatment appeared as a protective factor for thrombosis.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Lupus Eritematoso Sistémico/complicaciones , Trombosis/tratamiento farmacológico , Trombosis/etiología , Adulto , Anticuerpos Anticardiolipina/inmunología , Anticuerpos Antifosfolípidos/inmunología , Femenino , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Japón/epidemiología , Lupus Eritematoso Sistémico/diagnóstico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Trombosis/diagnóstico por imagen , Trombosis/prevención & control
5.
Epidemiol Infect ; 144(4): 864-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26265024

RESUMEN

Group A Streptococcus (GAS) are globally distributed bacterial pathogens. We examined the emm genotypes, which are important indicators of virulence, of 349 clinical GAS isolates collected using two surveillance systems, i.e. Invasive Bacterial Infection Surveillance (IBIS) from 2010 to 2011 (234 isolates) and routine surveillance of clinically isolated bacteria from various hospitals during 1996-2011 (115 isolates) in Thailand. The major emm genotypes in IBIS samples were emm44 (12·0%), emm104 (6·8%), emm22 (5·6%), and emm81 (5·6%), whereas only one isolate (0·4%) had the emm1 genotype, which is significantly more common in invasive cases in the Western world. In samples collected during routine surveillance, emm238 (10·4%), emm44 (8·7%), and emm165 (7·0%) were dominant. The major superantigen gene profiles were similar between the groups, and 30·1% of isolates did not possess the phage-encoded superantigens (speA, speC, speH, speI, speK, speL, speM, ssa). Although most isolates exhibited limited gene profiles, emm44 isolates had highly variable gene profiles (15 patterns). We conclude that emm44 is the predominant GAS genotype in Thailand, and isolates varied in superantigen gene profiles.


Asunto(s)
Antígenos Bacterianos/genética , Streptococcus pyogenes/inmunología , Superantígenos/genética , Factores de Virulencia/genética , Genotipo , Streptococcus pyogenes/genética , Tailandia
7.
Clin Microbiol Infect ; 20(5): O309-17, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24112138

RESUMEN

Chronic osteomyelitis of the jaw (COMJ) is one of the most intractable diseases among head and neck infections. Antimicrobial agents are routinely administered for COMJ without sufficient bacterial information, resulting in frequent treatment failures. To improve our knowledge of the bacterial aetiology of COMJ and to assist in the development of effective treatments, we performed a comprehensive analysis of the microbiome. Sixteen patients with four clinical types of COMJ (four with suppurative osteomyelitis, three with osteoradionecrosis of the jaw, four with primary chronic osteomyelitis, and five with bisphosphonate-related osteonecrosis of the jaw) were enrolled in this study. Bone samples were subjected to bacterial community comparisons by 16S rRNA gene pyrosequencing. As a result, we clarified that COMJ was caused by a far greater range of bacterial species (12 phyla and 163 genera) than previously reported. Moreover, the bacterial structures in COMJ changed dramatically with disease stage and the condition of the affected bone. Multiple correlation analyses revealed that sequestration and bone exposure could affect the community structure. On the basis of these factors, we reclassified COMJ into three clinical stages: I, inflamed or sclerotic bone without exposure; II, sequestrum without exposure; and III, exposed sequestrum. In stage II, the bacterial diversity was significantly lower, and the anaerobe genera Fusobacterium, Tannerella (formerly Bacteroides) and Porphyromonas were more abundant, than observed during other stages. Because these bacteria habitually reside in any clinical stage, they were considered to constitute the core microbiome of COMJ. Targeting these bacteria should lead to the development of effective preventive measures and cures.


Asunto(s)
Enfermedades Maxilomandibulares/microbiología , Microbiota , Osteomielitis/microbiología , Osteorradionecrosis/microbiología , Anciano , Anciano de 80 o más Años , Bacteroides/aislamiento & purificación , Osteonecrosis de los Maxilares Asociada a Difosfonatos/microbiología , Enfermedad Crónica , ADN Bacteriano/análisis , Femenino , Fusobacterium/aislamiento & purificación , Humanos , Masculino , Microbiota/genética , Persona de Mediana Edad , Filogeografía , Porphyromonas/aislamiento & purificación , ARN Ribosómico 16S/genética
8.
Cancer Gene Ther ; 18(8): 587-97, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21660064

RESUMEN

Although efforts have been made to develop new drugs for infectious and neoplastic diseases utilizing synthetic small interfering RNA(siRNAs), those intrinsically have undesirable effects, including silencing of unintended genes (off-target effect) and nonspecific cytotoxicity. Off-target effects can be avoided by DNA substitution in the guide strand (GS) seed region of nucleotide positions 1-8 and its complementary part of the passenger strand plus the 3' overhang, which is designated as a double-strand RNA-DNA chimera (dsRDC). In this study, we found that the specificity of potent siRNAs targeting human papillomavirus 16 (HPV16) E6 and E7 oncogenes, which we previously reported, could be enhanced by short dsRDC modification (first six nucleotides from the 5' end of the GS and its complementary nucleotides of the passenger strand). Such dsRDC modification reduced nonspecific cytotoxicity in two of three siRNAs (497 and 752), although not in the other (573), which correlated with their off-target effects. In addition, silencing activity was marginally impaired in two dsRDCs (497 and 573) and moderately in one (752). Finally, dsRDC-497 induced E6E7-specific growth suppression of cervical cancer cells as well as E6E7-immortalized human keratinocytes. Our results show that dsRDC modification enhances the specificity of E6E7 siRNA, which is required for use in in vivo settings.


Asunto(s)
ADN Viral/genética , Papillomavirus Humano 16/genética , Proteínas Oncogénicas Virales/genética , Proteínas E7 de Papillomavirus/genética , ARN Interferente Pequeño/genética , ARN Viral/genética , Proteínas Represoras/genética , Línea Celular Tumoral , Quimera/genética , Células HeLa , Humanos , Proteínas Oncogénicas Virales/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Interferencia de ARN , Proteínas Represoras/metabolismo , Transfección
9.
Phys Rev Lett ; 106(16): 162303, 2011 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-21599360

RESUMEN

High precision measurements of the differential cross sections for π0 photoproduction at forward angles for two nuclei, 12C and 208Pb, have been performed for incident photon energies of 4.9-5.5 GeV to extract the π0→γγ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The π0→γγ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is Γ(π0→γγ)=7.82±0.14(stat)±0.17(syst) eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions.

10.
Oncogene ; 28(30): 2738-44, 2009 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-19503096

RESUMEN

Epigenetic therapy using DNA methylation inhibitors and histone deacetylase (HDAC) inhibitors has clinical promise for the treatment of human malignancies. To investigate roles of microRNAs (miRNAs) on epigenetic therapy of gastric cancer, the miRNA expression profile was analysed in human gastric cancer cells treated with 5-aza-2'-deoxycytidine (5-Aza-CdR) and 4-phenylbutyric acid (PBA). miRNA microarray analysis shows that most of miRNAs activated by 5-Aza-CdR and PBA in gastric cancer cells are located at Alu repeats on chromosome 19. Analyses of chromatin modification show that DNA demethylation and HDAC inhibition at Alu repeats activates silenced miR-512-5p by RNA polymerase II. In addition, activation of miR-512-5p by epigenetic treatment induces suppression of Mcl-1, resulting in apoptosis of gastric cancer cells. These results suggest that chromatin remodeling at Alu repeats plays critical roles in the regulation of miRNA expression and that epigenetic activation of silenced Alu-associated miRNAs could be a novel therapeutic approach for gastric cancer.


Asunto(s)
Elementos Alu , Ensamble y Desensamble de Cromatina , Epigénesis Genética , MicroARNs/fisiología , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Neoplasias Gástricas/terapia , Apoptosis , Azacitidina/análogos & derivados , Azacitidina/farmacología , Línea Celular Tumoral , Cromosomas Humanos Par 19 , Metilación de ADN , ADN Polimerasa II/fisiología , ADN Polimerasa III/fisiología , Decitabina , Regulación hacia Abajo , Inhibidores de Histona Desacetilasas , Humanos , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Fenilbutiratos/farmacología , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología
11.
Heart ; 95(24): 2009-13, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19541690

RESUMEN

OBJECTIVE: To determine if the Niigata-Chuetsu earthquake of October 2004 increased long-term mortality from acute myocardial infarction (AMI). DESIGN: A comparative study of mortality rates before and after the earthquake, as well as between the disaster and control areas, by analysing death certificate data from 1 October 1999 to 30 September 2007. SETTING: The disaster area and a control area in Niigata Prefecture (n = 2 448 025 in 1 October 2004) in Japan. POPULATION: The total population of Niigata Prefecture observed for five years (12 333 429 person-years) before and three years (7 279 076 person-years) after the earthquake. MAIN OUTCOME MEASURES: Mortality from AMI (ICD-10, I21 and I22). RESULTS: Overall mortality rates from AMI five years before and three years after the earthquake in the disaster area were 47.3 and 53.9 per 100 000 person-years, respectively. Change (+6.6 or +14.0%) was significantly different (p = 0.0008), compared to the control area, where mortality rates were 42.5 and 42.6 per 100 000 person-years, respectively, and was not significantly different (p = 0.9028). In men, a change in AMI mortality before and after the earthquake in the disaster area was +7.1 per 100 000 person-years (+13.4%, p = 0.0172), and +2.0 (+4.2%, p = 0.2362) in the control area. In women, a change in AMI mortality in the disaster area was +6.2 per 100 000 person-years (+14.9%, p = 0.0184) and -1.6 (-4.2%, p = 0.2735) in the control area. CONCLUSIONS: The Niigata-Chuetsu earthquake significantly increased long-term mortality from AMI in both men and women. Clinicians and policymakers in public health must recognise the need for long-term prevention of AMI in earthquake disaster areas.


Asunto(s)
Desastres , Terremotos/mortalidad , Infarto del Miocardio/mortalidad , Estrés Psicológico/etiología , Anciano , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Enfermedad Crónica , Femenino , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Infarto del Miocardio/psicología , Factores de Riesgo , Distribución por Sexo , Estrés Psicológico/mortalidad , Tasa de Supervivencia
12.
Caries Res ; 42(6): 466-74, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18997467

RESUMEN

A new reliable genotyping method, multilocus sequence typing (MLST), was used to evaluate vertical transmission of the cariogenic pathogen Streptococcus mutans. A total of 136 S. mutans strains were isolated from saliva samples of 20 Japanese mother-child pairs, including 5 girls and 5 boys with primary dentition, and 5 girls and 5 boys with mixed dentition. The nucleotide sequences of 8 partial housekeeping genes, aroE, murI, gltA, glnA, glk, tkt, lepC, and gyrA, were analyzed and a similarity for all of those sequences between strains from a mother-child pair was regarded as indicating transmission, which was shown in 70% of the pairs. Interestingly, the rate of transmitted strains from mothers was significantly higher in the girls (90%) than in the boys (p = 0.001). Furthermore, the S. mutans sequence type (ST) with the highest distribution percentage in each maternal saliva sample was found to be transferred to their children. In addition, variations in two large conjugative-transfer associated regions, TnSmu1 and TnSmu2, were determined and compared with the STs defined by MLST. No variations in those two regions shown by PCR patterns were present in any of the strains isolated from the same families with the same STs, though isolates of some STs from different families showed distinct patterns for TnSmu2. Our results indicate that mothers are the main source for transmission of S. mutans to their children, while the present MLST method was also shown to be useful for investigating bacterial transmission.


Asunto(s)
Saliva/microbiología , Streptococcus mutans/aislamiento & purificación , Adulto , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Niño , Preescolar , ADN Bacteriano/análisis , Caries Dental/microbiología , Dentición Mixta , Salud de la Familia , Femenino , Humanos , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Persona de Mediana Edad , Madres , Análisis de Secuencia de ADN , Factores Sexuales , Infecciones Estreptocócicas/transmisión , Streptococcus mutans/genética , Diente Primario/microbiología , Adulto Joven
13.
Phys Rev Lett ; 101(1): 012301, 2008 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-18764105

RESUMEN

Incoherent eta photoproduction in nuclei is evaluated at forward angles within 4 to 9 GeV using a multiple scattering Monte Carlo cascade calculation with full eta-nucleus final-state interactions. The Primakoff, nuclear coherent and nuclear incoherent components of the cross sections fit remarkably well previous measurements for Be and Cu from Cornell, suggesting a destructive interference between the Coulomb and nuclear coherent amplitudes for Cu. The inelastic background of the data is consistently attributed to the nuclear incoherent part, which is clearly not isotropic as previously considered in Cornell's analysis. The respective Primakoff cross sections from Be and Cu give Gamma(eta-->gammagamma)=0.476(62) keV, where the quoted error is only statistical. This result is consistent with the Particle Data Group average of 0.510(26) keV and in sharp contrast (approximately 50%) with the value of 0.324(46) keV obtained at Cornell.

14.
Phys Rev Lett ; 97(21): 212001, 2006 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-17155738

RESUMEN

The mean square polarizability radii of the proton have been measured for the first time in a virtual-Compton-scattering experiment performed at the MIT-Bates out-of-plane scattering facility. Response functions and polarizabilities obtained from a dispersion analysis of the data at Q2 = 0.057 GeV2/c2 are in agreement with O(p3) heavy baryon chiral perturbation theory. The data support the dominance of mesonic effects in the polarizabilities.

15.
Phys Rev Lett ; 96(17): 174801, 2006 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-16712305

RESUMEN

The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

16.
Caries Res ; 39(4): 262-8, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15942184

RESUMEN

Previously, we isolated and characterized a new Streptococcus mutans strain (serotype k) from human blood and oral cavity samples, and found that the serological properties of serotype k strains were similar to those of a gluA-inactivated mutant strain of MT8148 (MT8148GD). MT8148GD showed significantly lower sucrose-dependent adhesion to glass surfaces, sucrose-independent adhesion to saliva-coated hydroxyapatite, dextran-binding activity, and cell-associated glucosyltransferase (GTF) activity than the parent strain. Further, Western blot analysis revealed reduced GTFB and GTFC expression in serotype k strains as compared to MT8148, though the caries-inducing activities of MT8148GD and a serotype k oral isolate in rats were similar to that of MT8148. We conclude that a glucose side-chain defect in the serotype-specific polysaccharide of S. mutans may be associated with its cariogenicity, though to a lesser extent than its other major surface proteins.


Asunto(s)
Caries Dental/microbiología , Glucosa/química , Polisacáridos Bacterianos/química , Infecciones Estreptocócicas/microbiología , Streptococcus mutans/patogenicidad , Animales , Adhesión Bacteriana , Proteínas Portadoras/genética , Dextranos/metabolismo , Durapatita/química , Vida Libre de Gérmenes , Vidrio/química , Glucosiltransferasas/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Lectinas , Masculino , Mutación/genética , Ratas , Ratas Sprague-Dawley , Saliva/fisiología , Serotipificación , Streptococcus mutans/clasificación , Streptococcus mutans/genética , Sacarosa/metabolismo
17.
Acta Neurochir (Wien) ; 147(6): 621-6; discussion 626, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15770350

RESUMEN

There is a potential risk of sacrificing the cortical vein during neurosurgical operations, particularly in the interhemispheric or subtemporal approach. An impaired cortical vein might cause cerebral venous circulatory disturbances (CVCDs) resulting in venous infarction. In this article, we have reviewed the management and results of eight cases with symptomatic postoperative venous infarction. We have encountered eight cases with symptomatic postoperative venous infarction (0.3%) during the past 5 years. The series is composed of 3 males and 5 females, with ages that ranged from 43 to 76 years (mean age of 58.1 years), and consisted of five brain tumors, one cavernoma, one dural AVF, and one trigeminal neuralgia. Initial symptoms occurred intra-operatively in two, on 0 day after the operation in one, 1 day in three, 3 days in one, and 4 days in one case. The symptoms were intra-operative brain edema in two cases, disorientation in one, cerebellar signs in one, hemiparesis in one, aphasia in two, and headache in one case. Two cases required surgical intervention. The results were a good outcome in 6 and a fair outcome in 2 cases. In conclusion, there are two types of postoperative venous infarction; severe onset (severe type) and gradual onset (mild type). The former needs immediate treatment from the intra-operative period onward, and the prevention of the ongoing venous thrombosis is essential in the latter.


Asunto(s)
Infarto Encefálico/etiología , Infarto Encefálico/terapia , Venas Cerebrales/cirugía , Senos Craneales/cirugía , Complicaciones Posoperatorias , Adulto , Anciano , Encefalopatías/cirugía , Infarto Encefálico/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
18.
Phys Rev Lett ; 94(2): 022003, 2005 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-15698166

RESUMEN

We report new precise H(e,e(')p)pi(0) measurements at the Delta(1232) resonance at Q(2)=0.127 (GeV/c)(2) obtained at the MIT-Bates out-of-plane scattering facility which are particularly sensitive to the transverse electric amplitude (E2) of the gamma(*)N-->Delta transition. The new data have been analyzed together with those of earlier measurements to yield precise quadrupole to dipole amplitude ratios: Re(E(3/2)(1+)/M(3/2)(1+))=(-2.3+/-0.3(stat+syst)+/-0.6(model))% and Re(S(3/2)(1+)/M(3/2)(1+))=(-6.1+/-0.2(stat+syst)+/-0.5(model))% for M(3/2)(1+)=(41.4+/-0.3(stat+syst)+/-0.4(model))(10(-3)/m(pi(+))). The derived amplitudes give credence to the conjecture of deformation in hadrons favoring, at low Q2, the dominance of mesonic effects.

19.
Oral Microbiol Immunol ; 19(3): 205-9, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15107074

RESUMEN

The fimA gene of Porphyromonas gingivalis, encoding fimbrillin (a subunit protein of fimbriae) has been classified into six genotypes (types I-V and Ib). The genotypic variation was previously suggested to be related to the severity of adult periodontitis in the general population. In this study, we compared inflammatory changes caused by bacterial infection to study pathogenic heterogeneity among the different fimA strains in a mouse abscess model. Bacterial suspensions of 13 P. gingivalis strains representing the six fimA types were subcutaneously injected into female BALB/c mice, and serum sialic acid concentrations were assayed as a quantitative host inflammatory parameter. Type II fimA organisms caused the most significant induction of serum sialic acid, as well as other infectious symptoms, followed by types Ib, IV and V. In contrast, types I and III caused weak inflammatory changes. In addition, fimA mutants of type II strains clearly lost their infectious ability. These findings suggest that fimA genotypic variation affects expression of P. gingivalis virulence.


Asunto(s)
Absceso/sangre , Infecciones por Bacteroidaceae/sangre , Proteínas Fimbrias/genética , Pili Sexual/genética , Porphyromonas gingivalis/genética , Enfermedades Cutáneas Bacterianas/sangre , Análisis de Varianza , Animales , Análisis por Conglomerados , Modelos Animales de Enfermedad , Femenino , Variación Genética , Genotipo , Ratones , Ratones Endogámicos BALB C , Mutación/genética , Ácido N-Acetilneuramínico/sangre , Porphyromonas gingivalis/patogenicidad , Virulencia/genética
20.
J Periodontal Res ; 37(6): 425-32, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12472836

RESUMEN

Porphyromonas gingivalis fimbriae are critical for the promotion of bacterial infection. The fimA gene encoding fimbrillin, a subunit of fimbriae, has been classified into five genotypes (types I to V) based on their nucleotide sequences. Using a fimA type-specific PCR assay, our previous study demonstrated a close relationship between P. gingivalis possessing type II and type IV fimA genes and adult periodontitis. In that study, some clinical specimens were found to be positive for both types I- and II- fimA specific primers, likely due to the coexistence of two clonal types or a single clone of an unknown genotype in the samples. In the present study, we cloned a new variant of the fimA gene, designated as type Ib fimA, from P. gingivalis HG1691. The nucleotide sequence of the cloned fimA gene showed a 97.1% homology with that of type I fimA, indicating it as a clonal variant of type I fimA. Organisms with type Ib fimA were detected in 13.5% of periodontitis patients and in 2.9% of periodontal healthy adults. Statistical analysis revealed a strong relationship between periodontitis and specific fimA types such as type Ib [odds ratio (OR) 6.51], type II (OR 77.8), and type IV (OR 7.54). Moreover, type Ib fimA-organisms were also found to be related to periodontitis in Down's syndrome (OR 1.91) and mentally disabled populations (OR 4.00). These findings suggest that P. gingivalis with type Ib fimA is closely associated with the progression of periodontitis, similar to organisms with type II and IV fimA.


Asunto(s)
Proteínas Fimbrias/genética , Periodontitis/microbiología , Personas con Discapacidades Mentales , Pili Sexual/genética , Porphyromonas gingivalis/genética , Adulto , Anciano , Secuencia de Bases , Estudios de Casos y Controles , Células Clonales , Intervalos de Confianza , Placa Dental/microbiología , Síndrome de Down/microbiología , Femenino , Proteínas Fimbrias/clasificación , Genotipo , Humanos , Discapacidad Intelectual/microbiología , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pili Sexual/clasificación , Porphyromonas gingivalis/clasificación , Homología de Secuencia de Ácido Nucleico
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