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1.
Insect Mol Biol ; 28(4): 568-577, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30737958

RESUMEN

Colour patterns in butterflies and moths are crucial traits for adaptation. Previous investigations have highlighted genes responsible for pigmentation (ie yellow and ebony). However, the mechanisms by which these genes are regulated in lepidopteran insects remain poorly understood. To elucidate this, molecular studies involving dipterans have largely analysed the cis-regulatory regions of pigmentation genes and have revealed cis-regulatory modularity. Here, we used well-developed transgenic techniques in Bombyx mori and demonstrated that cis-regulatory modularity controls tissue-specific expression of the yellow gene. We first identified which body parts are regulated by the yellow gene via black pigmentation. We then isolated three discrete regulatory elements driving tissue-specific gene expression in three regions of B. mori larvae. Finally, we found that there is no apparent sequence conservation of cis-regulatory regions between B. mori and Drosophila melanogaster, and no expression driven by the regulatory regions of one species when introduced into the other species. Therefore, the trans-regulatory landscapes of the yellow gene differ significantly between the two taxa. The results of this study confirm that lepidopteran species use cis-regulatory modules to control gene expression related to pigmentation, and represent a powerful cadre of transgenic tools for studying evolutionary developmental mechanisms.


Asunto(s)
Bombyx/genética , Expresión Génica/fisiología , Redes Reguladoras de Genes/fisiología , Genes de Insecto/fisiología , Pigmentación/genética , Animales , Bombyx/crecimiento & desarrollo , Bombyx/fisiología , Larva/genética , Larva/crecimiento & desarrollo , Larva/fisiología , Fenotipo
2.
Anim Genet ; 50(5): 449-459, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31282588

RESUMEN

Eight horse breeds-Hokkaido, Kiso, Misaki, Noma, Taishu, Tokara, Miyako and Yonaguni-are native to Japan. Although Japanese native breeds are believed to have originated from ancient Mongolian horses imported from the Korean Peninsula, the phylogenetic relationships among these breeds are not well elucidated. In the present study, we compared genetic diversity among 32 international horse breeds previously evaluated by the Equine Genetic Diversity Consortium, the eight Japanese native breeds and Japanese Thoroughbreds using genome-wide SNP genotype data. The proportion of polymorphic loci and expected heterozygosity showed that the native Japanese breeds, with the exception of the Hokkaido, have relatively low diversity compared to the other breeds sampled. Phylogenetic and cluster analyses demonstrated relationships among the breeds that largely reflect their geographic distribution in Japan. Based on these data, we suggest that Japanese horses originated from Mongolian horses migrating through the Korean Peninsula. The Japanese Thoroughbreds were distinct from the native breeds, and although they maintain similar overall diversity as Thoroughbreds from outside Japan, they also show evidence of uniqueness relative to the other Thoroughbred samples. This is the first study to place the eight native Japanese breeds and Japanese Thoroughbred in context with an international sample of diverse breeds.


Asunto(s)
Caballos/clasificación , Caballos/genética , Polimorfismo de Nucleótido Simple , Animales , Cruzamiento , Análisis por Conglomerados , Variación Genética , Estudio de Asociación del Genoma Completo , Japón , Filogenia , Análisis de Componente Principal
3.
Clin Chem ; 62(11): 1516-1523, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27591290

RESUMEN

BACKGROUND: An assay using a mouse antisialyl Lewis X (sLeX) antibody (CSLEX-1) is used clinically for screening and monitoring patients with breast cancer in Japan. However, the IgM isoform of CSLEX-1 is not preferred for the assay because the bulkiness of IgM generally causes poor accessibility to the antigen. To solve this problem, we developed an antisLeX mouse/human chimeric IgG antibody, CH-CSLEX-1, using transgenic silkworms. The performance of a homologous sandwich ELISA of CH-CSLEX1 was then evaluated. METHODS: To generate CH-CSLEX-1, we used a GAL4/UAS binary gene expression system in transgenic silkworms. The reactivities of CSLEX-1 and CH-CSLEX-1 were determined in a Biacore analysis. To confirm antigen specificity, 3 antigens [sLeX, sLeA, and Lewis Y (LeY)] were used. RESULTS: CH-CSLEX-1 formed correctly as an IgG class of immunoglobulin molecule with an isoelectric point close to the predicted value. The best combination for capturing and probing in a sandwich ELISA was determined as a homologous combination of CH-CSLEX-1. The CH-CSLEX-1 assay specifically detected sLeX, but not sLeA and LeY. A correlation analysis with 107 human samples showed good concordance between the conventional CSLEX-1 assay (homologous sandwich ELISA using CSLEX-1) and the CH-CSLEX-1 assay (r = 0.98). Moreover, the CH-CSLEX-1 assay was not affected by either human antimouse IgG antibodies (HAMA IgG) or HAMA IgM. CONCLUSIONS: The mouse/human chimeric antibody CH-CSLEX-1 allowed the establishment of a highly specific sandwich ELISA for sLeX that was not affected by HAMA.


Asunto(s)
Anticuerpos Monoclonales/química , Ensayo de Inmunoadsorción Enzimática/métodos , Proteínas Recombinantes de Fusión/química , Animales , Anticuerpos Monoclonales/análisis , Anticuerpos Monoclonales/inmunología , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/inmunología , Humanos , Ratones , Proteínas Recombinantes de Fusión/análisis , Proteínas Recombinantes de Fusión/inmunología
4.
J Radiol Prot ; 34(3): 675-98, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25125455

RESUMEN

Data related to radioactivity released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 15 March 2011 gathered by residents of Miharu, Fukushima Prefecture, and by Tohoku University are presented. These data sets consist of (1) the earliest radiation monitoring by a Geiger counter in the town, (2) ratios of radioactivity between (132)Te and (137)Cs for a wide area between Fukushima and Tokyo, (3) radiation measurement of soil samples collected from 18 school grounds, and (4) external radiation exposure of 1400 students using OSL badges. By combining and analysing these various data sets, a curve for the cumulative total external exposure as a function of time, with 16 : 00 h on 15 March 2011 being time zero, is obtained. The average cumulative external dosage is estimated to be 10 mSv (σ = 4.2 mSv) over 10 years. In addition, the initiative that the residents of Miharu took in response to the FDNPP accident, which became known as The Misho Project (MP), is documented; in particular, the time at which the municipality instructed the immediate ingestion of iodine tablets by those under the age of 40, 13 : 00 h on 15 March 2011, is assessed.


Asunto(s)
Accidente Nuclear de Fukushima , Plantas de Energía Nuclear , Radiación Ionizante , Radiometría/estadística & datos numéricos , Japón
5.
Nat Genet ; 26(1): 51-5, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10973247

RESUMEN

Usher syndrome type 1 (USH1) is an autosomal recessive sensory defect involving congenital profound sensorineural deafness, vestibular dysfunction and blindness (due to progressive retinitis pigmentosa)1. Six different USH1 loci have been reported. So far, only MYO7A (USH1B), encoding myosin VIIA, has been identified as a gene whose mutation causes the disease. Here, we report a gene underlying USH1C (MIM 276904), a USH1 subtype described in a population of Acadian descendants from Louisiana and in a Lebanese family. We identified this gene (USH1C), encoding a PDZ-domain-containing protein, harmonin, in a subtracted mouse cDNA library derived from inner ear sensory areas. In patients we found a splice-site mutation, a frameshift mutation and the expansion of an intronic variable number of tandem repeat (VNTR). We showed that, in the mouse inner ear, only the sensory hair cells express harmonin. The inner ear Ush1c transcripts predicted several harmonin isoforms, some containing an additional coiled-coil domain and a proline- and serine-rich region. As several of these transcripts were absent from the eye, we propose that USH1C also underlies the DFNB18 form of isolated deafness.


Asunto(s)
Proteínas Portadoras/genética , Mutación del Sistema de Lectura , Células Ciliadas Auditivas Internas/patología , Pérdida Auditiva Sensorineural/genética , Mutación , Degeneración Retiniana/genética , Proteínas Adaptadoras Transductoras de Señales , Alelos , Animales , Secuencia de Bases , Northern Blotting , Proteínas Portadoras/biosíntesis , Proteínas Portadoras/química , Proteínas de Ciclo Celular , Proteínas del Citoesqueleto , Análisis Mutacional de ADN , ADN Complementario/metabolismo , Exones , Salud de la Familia , Eliminación de Gen , Biblioteca de Genes , Células Ciliadas Auditivas Internas/metabolismo , Células Ciliadas Vestibulares/metabolismo , Heterocigoto , Humanos , Inmunohistoquímica , Intrones , Ratones , Repeticiones de Minisatélite/genética , Modelos Genéticos , Datos de Secuencia Molecular , Linaje , Isoformas de Proteínas , Estructura Terciaria de Proteína , Empalme del ARN/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Ácido Nucleico , Distribución Tisular , Transcripción Genética
6.
Mol Genet Genomics ; 287(9): 731-9, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22842670

RESUMEN

To construct an effective site-specific integration system in the silkworm, we examined if phiC31 integrase works in silkworm embryos. As an assay system, we constructed an extrachromosomal cassette exchange reaction system between two attP sites of an acceptor plasmid and two attB sites of a donor plasmid. To evaluate the activity, integrase mRNAs synthesized from three different plasmids were used. We injected a mixture of the acceptor and donor plasmids with the mRNA synthesized in vitro from one of the three plasmids into silkworm embryos at 4-6 h after oviposition and recovered plasmid DNAs from the embryos 3 days after injection. The resultant plasmids were transformed into Escherichia coli and spread on selection medium plates containing the appropriate antibiotics. A colony-forming assay and restriction enzyme digestion of the plasmids purified from the colonies showed that the phiC31 integrase worked very efficiently in the silkworm embryos. Notably, a phiC31 integrase mRNA synthesized from two of the plasmids produced cassette exchange plasmids at a high frequency, suggesting that the mRNA can be used to construct a targeted integration system in silkworms.


Asunto(s)
Bombyx/embriología , Bombyx/enzimología , Embrión no Mamífero/enzimología , Integrasas/metabolismo , Animales , Bombyx/genética , Femenino , Integrasas/genética , Mutagénesis Insercional/genética , Plásmidos/genética , Recombinación Genética
8.
J Hosp Infect ; 126: 16-20, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35452719

RESUMEN

BACKGROUND: The efficacy of bipolar ionization in the healthcare setting has yet to be proven. A major limitation of studies sponsored by industry has been the assessment of efficiency within test chambers in which ozone levels are not adequately controlled. AIM: To assess the effectiveness of bipolar ionization against antimicrobial-resistant bacteria, fungi and human coronavirus within a controlled test chamber designed to mitigate the effect of ozone. METHODS: Bacteria- and fungi-inoculated gauze pads, and human coronavirus 229E-inoculated stainless steel plates were placed within the vicinity of the AIO-2 bipolar ionizer and left at room temperature (2 h for coronavirus and 4 h for bacteria and fungi). FINDINGS: Four hours of exposure to bipolar ionization showed a 1.23-4.76 log reduction, corresponding to a 94.2->99.9% colony-forming units/gauze reduction, in Clostridioides difficile, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae, meticillin-resistant Staphylococcus aureus and multi-drug-resistant S. aureus. A 1.2 log 50% tissue culture infectious dose reduction in human coronavirus was observed after 2 h. CONCLUSION: The assessment of bipolar ionization systems merits further investigation as an infection control measure.


Asunto(s)
Antiinfecciosos , Coronavirus , Staphylococcus aureus Resistente a Meticilina , Ozono , Aspergillus , Bacterias , Humanos , Saccharomyces cerevisiae
9.
Science ; 267(5199): 897-9, 1995 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-7846533

RESUMEN

Plasmids carrying gene pairs encoding type II DNA restriction endonucleases and their cognate modification enzymes were shown to have increased stability in Escherichia coli. The descendants of cells that had lost these genes appeared unable to modify a sufficient number of recognition sites in their chromosomes to protect them from lethal attack by the remaining restriction enzyme molecules. The capacity of these genes to act as a selfish symbiont is likely to have contributed to the evolution of restriction-modification gene pairs.


Asunto(s)
Enzimas de Restricción-Modificación del ADN/genética , Escherichia coli/genética , Plásmidos , Apoptosis , Cromosomas Bacterianos/genética , Cromosomas Bacterianos/metabolismo , Enzimas de Restricción-Modificación del ADN/metabolismo , ADN Bacteriano/metabolismo , Desoxirribonucleasas de Localización Especificada Tipo II/genética , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Escherichia coli/citología , Escherichia coli/enzimología , Genes Bacterianos , Transformación Bacteriana
10.
Aust Dent J ; 54(1): 49-53, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19228133

RESUMEN

This study presents the radiographic findings of two cases of static bone cavity in the inferior aspect of the condylar neck and mandibular notch of the mandible. On plain CT, a soft tissue mass was observed in each cavity. The submandibular gland and the other glands were not found in each cavity. On contrast-enhanced CT, the soft tissue in the cavity in the inferior aspect of the condylar neck had marked linear enhancement and dilated vasculature structure was observed in the cavity. On the contrast-enhanced MRI, the soft tissue in the cavity of the mandibular notch had marked enhancement and flow void was detected in the cavity. In the inferior aspect of the condylar neck, the cavity size had enlarged radiographically over a period of three years. Vascular lesions were found in the cavity located in the inferior aspect of the condylar neck and mandibular notch of the mandible by both CT and MRI. The vascular lesion might explain the enlargement of the static bone cavity.


Asunto(s)
Quistes Maxilomandibulares/patología , Enfermedades Mandibulares/patología , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Quistes Maxilomandibulares/irrigación sanguínea , Quistes Maxilomandibulares/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Enfermedades Mandibulares/diagnóstico por imagen , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
11.
Radiography (Lond) ; 25(1): 72-76, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30599834

RESUMEN

INTRODUCTION: Breast cancer incidence increases from the age of 30 years. As this age range coincides with that in which women usually pursue pregnancy, undergoing medical examinations for conditions such as breast cancer is a concern, especially when pregnancy is uncertain during the first eight weeks. Moreover, in this age range, breast often exhibits a high density, thus compromising diagnosis. For such density, digital breast tomosynthesis (DBT) provides a more accurate diagnosis than 2D mammography given its higher sensitivity and specificity. However, radiation exposure increases during DBT, and it should be determined. METHODS: We determined the entrance surface dose, scattered radiation dose, and average glandular dose (AGD), which can be mutually compared following an international protocol. Using our proposed method, the distribution of scattered radiation can be easily and quickly obtained with a minor load to the equipment. Then, we can determine the indoor scattered radiation and surface dose on patients during DBT. RESULTS: We obtained a maximum AGD of 2.32 mGy. The scattered radiation was distributed over both sides with maximum of approximately 40 µGy, whereas the maximum dose around the eye was approximately 10 µGy. CONCLUSION: By measuring doses using the proposed method, a correct dose information can be provided for patients to mitigate their concerns about radiation exposure. Although the obtained doses were low, their proper management is still required. Overall, the results from this study can help to enhance dose management for patients and safety management regarding indoor radiation.


Asunto(s)
Mamografía/métodos , Fantasmas de Imagen , Dosis de Radiación , Exposición a la Radiación/estadística & datos numéricos , Sensibilidad y Especificidad
12.
Curr Opin Genet Dev ; 9(6): 649-56, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10607611

RESUMEN

A restriction enzyme gene is often linked to a modification methylase gene the role of which is to protect a recognition site on DNA from breakage by the former. Loss of some restriction-modification gene complexes leads to cell death through restriction breakage in the genome. Their behavior as genomic parasites/symbionts may explain the distribution of restriction sites and clarify certain aspects of bacterial recombination repair and mutagenesis. A comparison of bacterial genomes supports the hypothesis that restriction-modification gene complexes are mobile elements involved in various genome rearrangements and evolution.


Asunto(s)
Enzimas de Restricción del ADN/genética , Evolución Molecular , Genes Bacterianos/genética , Genoma Bacteriano , Secuencias Repetitivas Esparcidas/genética , Bacterias/enzimología , Bacterias/genética , Enzimas de Restricción del ADN/metabolismo , Interacciones Huésped-Parásitos/genética , Mutagénesis/genética , Recombinación Genética/genética
13.
Eur J Anaesthesiol ; 25(2): 144-51, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17697397

RESUMEN

BACKGROUND: We have previously demonstrated, in the isolated rat heart, that propofol attenuates hydrogen peroxide-induced damage and ischaemia-reperfusion injury, and that the beneficial effect of propofol is correlated with reduction of the lipid peroxidation. This study was designed to evaluate whether propofol has a cardioprotective effect against ischaemia-reperfusion injury in a rat model in vivo. METHODS: Adult rats were anaesthetized with pentobarbital 10 mg kg(-1) h(-1) alone (control group), pentobarbital 10 or 20 mg kg(-1) h(-1) + Intralipid as a vehicle (Pent-10, Pent-20 group), propofol 10 or 20 mg kg(-1) h(-1) (Prop-10, Prop-20 group) intravenously throughout the experiment. The left anterior descending coronary artery was occluded for 30 min followed by 120 min of reperfusion. Infarct size was determined at the end of reperfusion. The tissue concentration of malondialdehyde was measured at 30 min after reperfusion to evaluate lipid peroxidation. RESULTS: The infarct sizes (% of area at risk) were significantly smaller in the Prop-10 (54 +/- 11%; P < 0.01 vs. control) and Prop-20 (39 +/- 8%; P < 0.01 vs. control) groups than in the control (68 +/- 9%), Pent-10 (69 +/- 13%) and Pent-20 (68 +/- 14%) groups (n = 12). In the Pent-10 and Pent-20 groups, ischaemia-reperfusion produced significant increases in the values for tissue malondialdehyde (0.72 +/- 0.24 micromol mg protein-1; P < 0.05 and 0.63 +/- 0.33 micromol mg protein-1; P < 0.05 vs. 0.46 +/- 0.22 micromol mg protein-1 in non-ischaemic hearts, n = 8). However, the values of malondialdehyde in the Prop-10 and -20 groups were suppressed by 41% and 63%, respectively, compared with the Pent-10 group (P < 0.01). CONCLUSION: Our results suggest that propofol could be cardioprotective against ischaemia-reperfusion injury dose dependently in a rat model in vivo and that the beneficial action of propofol may be correlated with its antioxidant effect.


Asunto(s)
Anestésicos Intravenosos/farmacología , Corazón/efectos de los fármacos , Propofol/farmacología , Daño por Reperfusión/prevención & control , Animales , Antioxidantes/farmacología , Presión Sanguínea/efectos de los fármacos , Cardiotónicos/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Frecuencia Cardíaca/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/metabolismo , Ratas , Ratas Sprague-Dawley , Índice de Severidad de la Enfermedad , Factores de Tiempo
14.
Reprod Domest Anim ; 43(3): 382-384, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18179630

RESUMEN

Two Holstein heifers and a cow were diagnosed with White Heifer Disease by ultrasonography. Case 1 was a 14 month-old heifer with aplasia of both sides of the uterine horn. In case 2, a primiparous cow and case 3, an 18 month-old heifer, both showed aplasia of the right uterine horn. Case 2 became pregnant by artificial insemination at ipsilateral ovulatory follicle and corpus luteum in the left ovary, while case 3 became pregnant by embryo transfer at 7 days after oestrus with contralateral corpus luteum in the right ovary.


Asunto(s)
Transferencia de Embrión/veterinaria , Inseminación Artificial/veterinaria , Conductos Paramesonéfricos/anomalías , Preñez , Neoplasias Uterinas/veterinaria , Enfermedad de las Vaquillonas Blancas/genética , Animales , Bovinos , Femenino , Genes Recesivos , Infertilidad Femenina/genética , Infertilidad Femenina/veterinaria , Inseminación Artificial/métodos , Embarazo , Neoplasias Uterinas/genética , Neoplasias Uterinas/fisiopatología , Útero/anomalías , Enfermedad de las Vaquillonas Blancas/fisiopatología
15.
Trends Genet ; 14(9): 368-74, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9769733

RESUMEN

Type II restriction-modification gene complexes, such as the EcoRI system, are not easily lost from their host cell. The descendants of cells that lose a restriction-modification gene complex are unable to modify a sufficient number of recognition sites in their chromosomes to protect them from lethal attack by the remaining molecules of restriction enzyme. This capacity to act as a selfish genetic element is likely to have contributed to the spread and maintenance of restriction-modification systems. Homologous recombination machineries of cells and viruses appear to be well adapted to cope with these elements. By extrapolation, the capacity of mitochondria to kill their host eukaryotic cell might have stabilized their initial symbiosis.


Asunto(s)
Enzimas de Restricción-Modificación del ADN/genética , Mitocondrias/genética , Recombinación Genética , Apoptosis/genética , Bacterias/genética , Bacterias/virología , Bacteriófagos/genética , Bacteriófagos/metabolismo , Reparación del ADN , Modelos Biológicos , Simbiosis
17.
J Hosp Infect ; 97(3): 296-300, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28756169

RESUMEN

BACKGROUND: In recent years, installation of bidet toilets within hospitals in Japan has raised concerns regarding potential for cross-contamination by antimicrobial-resistant bacteria from patients who are hospitalized over an extended period. AIM: To investigate the distribution of antimicrobial-resistant bacteria recovered from bidet toilets at a university-affiliated hospital in Japan. METHODS: All 292 electric bidet toilets at a university hospital were sampled for contamination. Swabs for culture were used to sample water-jet nozzles and toilet seats. FINDINGS: Of the 292 toilet seats sampled, warm-water nozzles of 254 (86.9%) were found to be contaminated by one or more of the following organisms: Staphylococcus aureus, Streptococcus spp., Enterococcus spp., Enterobacteriaceae and non-Enterobacteriaceae Gram-negative bacteria. S. aureus was recovered from one water-jet nozzle and nine toilet seats; of these, meticillin-resistant S. aureus was recovered from the water-jet nozzle and from one toilet seat. Both the water-jet nozzle and seat of the same toilet were contaminated with a CTX-M-9 group extended-spectrum ß-lactamase-producing Escherichia coli. Of the Gram-negative isolates recovered from samples, the organism with the highest frequency of isolation was Stenotrophomonas maltophilia, which was recovered from 39 bidet toilets. CONCLUSION: Warm-water nozzles of bidet toilets are contaminated with a wide range of bacteria, making them a potential vehicle for cross-infection. In the hospital setting, shared use of bidet toilets must consider the clinical background of patients. Based on these findings, these devices must be part of the risk management programme, and steps should be included for monitoring and disinfection.


Asunto(s)
Microbiología Ambiental , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Hospitales Universitarios , Cuartos de Baño , Infección Hospitalaria/epidemiología , Estudios Transversales , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Humanos , Japón , Medición de Riesgo
18.
AJNR Am J Neuroradiol ; 27(2): 258-60, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16484387

RESUMEN

We describe the case of a 26-year-old man who presented with symptoms compatible with Lhermitte sign that occurred during yawning. It was associated with congenital partial aplasia of the posterior arch of the atlas. Cervical multisection-detector CT myelography during yawning showed compression of the upper cervical cord due to the inward mobility of the isolated posterior tubercle. The symptoms completely disappeared following removal of the isolated posterior tubercle.


Asunto(s)
Atlas Cervical/anomalías , Lóbulo Frontal/lesiones , Traumatismos Cerrados de la Cabeza/diagnóstico , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Imagen por Resonancia Magnética , Mielografía , Compresión de la Médula Espinal/congénito , Tomografía Computarizada Espiral , Bostezo/fisiología , Adulto , Atlas Cervical/patología , Atlas Cervical/cirugía , Vértebras Cervicales/patología , Vértebras Cervicales/cirugía , Femenino , Movimientos de la Cabeza/fisiología , Humanos , Compresión de la Médula Espinal/diagnóstico , Compresión de la Médula Espinal/cirugía
19.
Nucleic Acids Res ; 29(18): 3742-56, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11557807

RESUMEN

Restriction-modification (RM) systems are composed of genes that encode a restriction enzyme and a modification methylase. RM systems sometimes behave as discrete units of life, like viruses and transposons. RM complexes attack invading DNA that has not been properly modified and thus may serve as a tool of defense for bacterial cells. However, any threat to their maintenance, such as a challenge by a competing genetic element (an incompatible plasmid or an allelic homologous stretch of DNA, for example) can lead to cell death through restriction breakage in the genome. This post-segregational or post-disturbance cell killing may provide the RM complexes (and any DNA linked with them) with a competitive advantage. There is evidence that they have undergone extensive horizontal transfer between genomes, as inferred from their sequence homology, codon usage bias and GC content difference. They are often linked with mobile genetic elements such as plasmids, viruses, transposons and integrons. The comparison of closely related bacterial genomes also suggests that, at times, RM genes themselves behave as mobile elements and cause genome rearrangements. Indeed some bacterial genomes that survived post-disturbance attack by an RM gene complex in the laboratory have experienced genome rearrangements. The avoidance of some restriction sites by bacterial genomes may result from selection by past restriction attacks. Both bacteriophages and bacteria also appear to use homologous recombination to cope with the selfish behavior of RM systems. RM systems compete with each other in several ways. One is competition for recognition sequences in post-segregational killing. Another is super-infection exclusion, that is, the killing of the cell carrying an RM system when it is infected with another RM system of the same regulatory specificity but of a different sequence specificity. The capacity of RM systems to act as selfish, mobile genetic elements may underlie the structure and function of RM enzymes.


Asunto(s)
Enzimas de Restricción-Modificación del ADN/metabolismo , Elementos Transponibles de ADN/genética , Evolución Molecular , Genoma Bacteriano , Secuencia de Bases , Enzimas de Restricción-Modificación del ADN/genética , ADN Bacteriano/genética , ADN Bacteriano/metabolismo
20.
Radiat Prot Dosimetry ; 120(1-4): 470-4, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16597695

RESUMEN

Atomic force microscopy (AFM) has been applied to the analysis of CR-39 nuclear track detectors for high dose neutron dosimetry. As a feasible study to extract the neutron dose, we have employed a (239)Pu-Be neutron source with the traditional track density measurement of recoil proton etch pits from a high density polyethylene (CH(2)) radiator. After very short etching ( approximately 1 microm), etch pit densities were measured as a function of neutron fluence (neutron dose) up to 1.4 x 10(10) cm(-2) (6.6 Sv). Neutron sensitivity was also measured to be 6.6 x 10(-4). Maximum measurable neutron dose was estimated to be approximately 200 Sv by measuring the fraction of the total image area occupied by the etch pits.


Asunto(s)
Microscopía de Fuerza Atómica/métodos , Polietilenglicoles/química , Polietilenglicoles/efectos de la radiación , Protección Radiológica/instrumentación , Dosimetría Termoluminiscente/instrumentación , Relación Dosis-Respuesta en la Radiación , Diseño de Equipo , Análisis de Falla de Equipo , Ensayo de Materiales , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Propiedades de Superficie , Dosimetría Termoluminiscente/métodos
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