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1.
J Extracell Vesicles ; 8(1): 1590116, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30911363

RESUMEN

All living organisms secrete molecules for intercellular communication. Recent research has revealed that extracellular vesicles (EVs) play an important role in inter-organismal cell-to-cell communication by transporting diverse messenger molecules, including RNA, DNA, lipids and proteins. These discoveries have raised fundamental questions regarding EV biology. How are EVs biosynthesized and loaded with messenger/cargo molecules? How are EVs secreted into the extracellular matrix? What are the EV uptake mechanisms of recipient cells? As EVs are produced by all kind of organisms, from unicellular bacteria and protists, filamentous fungi and oomycetes, to complex multicellular life forms such as plants and animals, basic research in diverse model systems is urgently needed to shed light on the multifaceted biology of EVs and their role in inter-organismal communications. To help catalyse progress in this emerging field, a mini-symposium was held in Munich, Germany in August 2018. This report highlights recent progress and major questions being pursued across a very diverse group of model systems, all united by the question of how EVs contribute to inter-organismal communication.

2.
Phytopathology ; 105(7): 966-81, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25760519

RESUMEN

Phytophthora infestans has been a named pathogen for well over 150 years and yet it continues to "emerge", with thousands of articles published each year on it and the late blight disease that it causes. This review explores five attributes of this oomycete pathogen that maintain this constant attention. First, the historical tragedy associated with this disease (Irish potato famine) causes many people to be fascinated with the pathogen. Current technology now enables investigators to answer some questions of historical significance. Second, the devastation caused by the pathogen continues to appear in surprising new locations or with surprising new intensity. Third, populations of P. infestans worldwide are in flux, with changes that have major implications to disease management. Fourth, the genomics revolution has enabled investigators to make tremendous progress in terms of understanding the molecular biology (especially the pathogenicity) of P. infestans. Fifth, there remain many compelling unanswered questions.


Asunto(s)
Interacciones Huésped-Patógeno , Phytophthora infestans/fisiología , Enfermedades de las Plantas/historia , Solanum lycopersicum/microbiología , Solanum tuberosum/microbiología , Genómica , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Enfermedades de las Plantas/microbiología
3.
Clin Genet ; 87(3): 209-17, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24828354

RESUMEN

In-person genetic counselling (GC) is the model typically used to provide patients with information regarding their genetic testing options. Current and emerging demand for genetic testing may overburden the health care system and exceed the available numbers of genetic counsellors. Furthermore, GC is not always available at times and places convenient for patients. There is little evidence that the in-person model alone is always optimal and alternatives to in-person GC have been studied in genetics and other areas of health care. This review summarizes the published evidence between 1994 and March 2014 for interactive e-learning and decisional support e-tools that could be used in pre-test GC. A total of 21 papers from 15 heterogeneous studies of interactive e-learning tools, with or without decision aids, were reviewed. Study populations, designs, and outcomes varied widely but most used an e-tool as an adjunct to conventional GC. Knowledge acquisition and decisional comfort were achieved and the e-tools were generally well-accepted by users. In a time when health care budgets are constrained and availability of GC is limited, research is needed to determine the specific circumstances in which e-tools might replace or supplement some of the functions of genetic counsellors.


Asunto(s)
Toma de Decisiones , Asesoramiento Genético/métodos , Internet , Femenino , Pruebas Genéticas , Humanos
5.
J Genet Couns ; 23(4): 463-73, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23709124

RESUMEN

There are several unresolved challenges associated with the clinical application of genome-wide sequencing technologies. One of the most discussed issues is incidental findings (IF), which are defined as discoveries made as a result of genetic testing that are unrelated to the indication for the test. The discussion surrounding IF began in the context of research, which we have used to frame consideration of IF in the clinical context. There is growing consensus that analytically valid and medically actionable IF should be offered to patients, but whether and to what extent clinicians should disclose other kinds of IF is debated. While others have systematically reviewed the literature concerning genetic IF, previous reviews focus on ethical and research-related issues and do not consider the implications for the genetic counseling profession specifically. This review discusses the practical considerations, ethical concerns and genetic counseling issues related to IF, with a particular focus on clinical genome-wide sequencing. To date, the bulk of the literature with respect to IF in the clinical context consists of commentaries, reviews and case reports. There is a need for more empirical studies to provide a foundation for institutional protocols and evidence-based clinical practice standards.


Asunto(s)
Genoma Humano , Hallazgos Incidentales , Análisis de Secuencia , Humanos
6.
Scand J Med Sci Sports ; 24(2): e111-20, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23992527

RESUMEN

The present study examined the impact of reputation information on athletes' behavioral responses to coaches within a naturalistic, field-based setting. Using a between-group design, male soccer players (n = 35) were assigned to one of three experimental conditions (i.e., experienced reputation, inexperienced reputation, no reputation) prior to taking part in a coaching session delivered by an unknown coach. Participants' behaviors indicative of attention to coach instruction, effort and persistence, and willingness to participate in demonstrations were video recorded throughout the coaching session. Multivariate analyses of variance revealed that participants in the experienced reputation condition exhibited significantly greater attention to coach instruction, and greater effort and persistence during free practice than participants in the inexperienced reputation condition. Results related to participants' willingness to participate in demonstrations failed to yield any significant differences. The results provide further evidence to support the contention that athletes use reputation information as a basis for their initial expectancies of coaches, and such expectancies have the potential to influence athletes' behavior during coach-athlete interactions. The findings also indicate that expectancies based on positive information may be more powerful than negatively framed expectancies, and can be harnessed by coaches as a means of developing effective relationships with their athletes.


Asunto(s)
Atletas/psicología , Rendimiento Atlético/psicología , Conducta Cooperativa , Competencia Profesional , Fútbol/psicología , Adolescente , Atención , Movimientos Oculares , Humanos , Relaciones Interpersonales , Masculino , Análisis Multivariante , Percepción , Esfuerzo Físico , Adulto Joven
7.
Clin Genet ; 82(6): 591-3, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22014292

RESUMEN

With the growing number of clinical guidelines recommending genetics tests in routine clinical care, the value of these tests should be evaluated. We examined the economic value of offering genetic testing to children with possible neurofibromatosis 1 (NF1) in British Columbia. Diagnosis of NF1 is usually made based on diagnostic clinical criteria, but molecular diagnostic testing, currently offered on a case-by-case basis in BC, now reliably diagnoses NF1 in 95% of cases. Children who present with some clinical features but whose findings are insufficient to meet the diagnostic criteria are labelled as having 'possible NF1'. Current guidelines call for these children to be followed as they have NF1, leading to annual ophthalmologic examinations and screening for complications; thus, there are increased costs to health care system. We created a model to account for these costs to the health care system, comparing the current protocol with one that would offer all children diagnosed with possible NF1 with genetic testing. Focusing on the incremental cost allowed us to determine that genetic testing provides good value, and patient interviews provided insight into the qualitative benefits of an earlier firm diagnosis. These findings may be helpful in guiding health policy decision-making.


Asunto(s)
Pruebas Genéticas/economía , Modelos Económicos , Neurofibromatosis 1/genética , Colombia Británica , Niño , Análisis Costo-Beneficio , Pruebas Genéticas/métodos , Humanos
8.
Cytopathology ; 20(6): 380-7, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19207308

RESUMEN

INTRODUCTION: Conventional Pap smears (CPS) have little impact on the detection of endometrial carcinoma. Although liquid-based cytology (LBC) is replacing CPS in the UK, experience with identification of endometrial cancers with this technique is limited. AIM: To compare the accuracy of the SurePath LBC with that of CPS for detection of endometrial cancers. METHODS: Our study group comprised SurePath LBC samples reported as atypical endometrial cells and endometrial adenocarcinoma (classified respectively as borderline, code 8 and ?glandular neoplasia, code 6 for the NHS Cervical Screening Programme statistics) in 2004-2005. CPS reported as atypical endometrial cells or adenocarcinoma in 1993-1998 comprised the control group. Histological follow-up was obtained. RESULTS: Endometrial abnormalities were reported in 95 (0.073%) of 130 352 LBC samples, comprising 75 (0.058%) atypical endometrial cells and 20 (0.015%) endometrial adenocarcinoma reports. Of 409 495 CPS, 117 (0.029%) were diagnosed as endometrial abnormalities, comprising 59 (0.014%) atypical endometrial cells and 58 (0.014%) endometrial adenocarcinoma reports. Thus, the endometrial adenocarcinoma reporting rate was similar in both groups, but that for atypical endometrial cells was higher with LBC (P < 0.001). The positive predictive value for endometrial cancer of endometrial adenocarcinoma and atypical endometrial cell reports in the LBC group was 73.3 and 18.8%, respectively, compared with 42.3 and 6.7% in the CPS group. The endometrial adenocarcinoma patients in CPS group were older (mean age 62.5 years versus 56.5 years) and most (22/25) were symptomatic, whereas most (13/17) patients in the LBC group were asymptomatic at the time of sampling (P < 0.001). CONCLUSION: SurePath LBC is at least as accurate a method for detecting endometrial cancer as CPS. SurePath LBC demonstrates enhanced identification of endometrial pathology in asymptomatic women in the cervical screening programme.


Asunto(s)
Técnicas Citológicas/métodos , Neoplasias Endometriales/diagnóstico , Adulto , Anciano , Neoplasias Endometriales/patología , Femenino , Humanos , Tamizaje Masivo , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad
9.
Clin Genet ; 72(6): 524-7, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18001351

RESUMEN

Neurofibromatosis 1 (NF1) is an autosomal dominant disease that is associated with multiple café-au-lait spots and neurofibromas. Low bone mineral density is frequent in people with NF1, and focal bony abnormalities are characteristic but uncommon features. Dental abnormalities can occur in association with oral neurofibromas but have not otherwise been described in people with NF1. Questionnaires regarding dental caries were sent to families that included at least one individual with NF1. Siblings with NF1 reported significantly more dental caries (mean +/- SD, 8.1 +/- 6.6) than siblings without NF1 in these families (5.5 +/- 5.8, p = 0.019). Our findings suggest that dental caries occur more frequently than expected among people with NF1 and that individuals with this condition may require a modified dental care program.


Asunto(s)
Caries Dental/etiología , Caries Dental/genética , Neurofibromatosis 1/complicaciones , Neurofibromatosis 1/genética , Adolescente , Adulto , Anciano , Colombia Británica , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Hermanos , Encuestas y Cuestionarios
10.
Am J Med Genet A ; 143A(12): 1326-33, 2007 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-17506102

RESUMEN

The characteristic sites of Neurofibromatosis 1-associated osseous manifestations are the long bones (usually the tibia and fibula), vertebrae and sphenoid wing. Although these focal bony lesions may cause profound clinical consequences, a minority of people with NF1 are affected. However, most people with NF1 are shorter than expected for their age, gender and family. The pathogenesis of NF1 focal osteopathy and its relationship, if any, to short stature are unknown. We examined associations between the occurrence of various osseous lesions in 3377 NF1 probands from the Children's Tumor Foundation NF International Database. Using logistic regression analysis among 260 NF1 probands who had undergone radiological examination of both the spine and skull, we found associations between the occurrence of sphenoid wing and long bone osteopathy (conditional odds ratio [OR] = 6.1; 95% confidence interval [CI] = 1.7-22.3; P = 0.006) and between sphenoid wing and vertebral osteopathy (OR = 16.9; 95% CI = 5.3-53.3; P < 0.001) after adjusting for age and gender. Similar findings were observed from all 3377 NF1 probands using a multivariate probit regression model. In a separate analysis, we found lower age- and gender-standardized height in patients who had characteristic vertebral or sphenoid wing lesions than in people who did not (P < 0.05). We found no relationship between height and tibial osteopathy. We conclude that some people with NF1 are more likely to develop osseous manifestations than others and speculate that there may be a common pathogenetic mechanism responsible for the development of osseous abnormalities and that of the vertebrae and long bones.


Asunto(s)
Enfermedades Óseas/etiología , Enfermedades Óseas/patología , Neurofibromatosis 1/complicaciones , Neurofibromatosis 1/patología , Estatura , Femenino , Peroné/patología , Humanos , Modelos Logísticos , Masculino , Neurofibromatosis 1/genética , Neurofibromina 1/genética , Oportunidad Relativa , Hueso Esfenoides/patología , Columna Vertebral/patología , Tibia/patología
11.
J Voice ; 21(2): 127-37, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16504472

RESUMEN

SUMMARY: Many professional operatic singers sing the vowel /a/ with a velopharyngeal opening.(1) Here resonatory effects of such an opening are analyzed. On the basis of CAT scan imaging of a baritone singer's vocal tract and nasal cavity system, including the maxillary sinuses, acoustic epoxy models were constructed, in which velopharyngeal openings were modeled by different tubes. The sound transfer characteristics of this model were determined by means of sine-tone sweep measurements. In an idealized (iron tube) model, the VPO introduced a zero in the transfer function at the frequency of the nasal resonance. In the epoxy models, however, the resonances of the nasal system, and hence the zero, were heavily damped, particularly when the maxillary sinuses were included in the nasal system. A velopharyngeal opening was found to attenuate the first formant in /a/, such that the relative level of the singer's formant increased. A similar effect was observed in a modified epoxy model shaped to approximate the vocal tract of an /u/ and an /i/, although it also showed a substantial widening of the first formant bandwidth. Varying the size of the velopharyngeal opening affected the transfer function only slightly. It seems likely that singers can enhance higher spectrum partials by a careful tuning of a velopharyngeal opening.


Asunto(s)
Senos Paranasales/fisiología , Fonación , Calidad de la Voz , Humanos , Pliegues Vocales/fisiología
12.
Colorectal Dis ; 7(3): 251-3, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15859963

RESUMEN

OBJECTIVE: Self-expanding metallic stents (SEMS) are an important addition to the treatment of large bowel obstruction. The aim of this study was firstly to assess bowel function following SEMS placement and secondly to identify any potential factors which might aid in the prediction of technical failure of stent insertion. METHODS: A review of all patients undergoing attempted SEMS placement for palliation of malignant left-sided colorectal obstruction over a four-year period (1st May 2000-30th April 2004) was performed. RESULTS: Twenty-one patients (12 male) with a median age of 76 years (range 48-92 years) were included, 11 with metastatic disease and 10 severe comorbidity. SEMS insertion was technically successful in 16 (76%) of 21 cases. Contrast successfully passed through the obstructing lesion in all 16 cases where SEMS placement was technically successful. It only passed through 1 of 5 cases where stenting was not possible (P = 0.0008, Fisher's Exact test). Complications included colonic perforation (1 case), stent migration (1 case) and tumour ingrowth requiring a second stent (1 case). Median survival after SEMS was 12 months (range 1-30 months), and 9 patients died during follow-up. Median bowel frequency following SEMS was 3.5 times per day (range 1-7). Eight patients always passed a liquid stool, 3 others regularly required laxatives and one further patient with poor function after stenting requested a defunctioning stoma. CONCLUSION: Failure of contrast to pass through the obstructing lesion may predict those cases where stenting will not be technically possible. Median survival following SEMS insertion is encouraging in this series, but bowel function is often poor. Expected bowel function should be discussed fully when consenting patients for a SEMS, particularly those with metastatic disease who are otherwise fit for resectional surgery.


Asunto(s)
Colon/fisiopatología , Neoplasias Colorrectales/cirugía , Motilidad Gastrointestinal/fisiología , Obstrucción Intestinal/cirugía , Cuidados Paliativos/métodos , Implantación de Prótesis/instrumentación , Stents , Anciano , Anciano de 80 o más Años , Colon/cirugía , Neoplasias Colorrectales/complicaciones , Neoplasias Colorrectales/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Obstrucción Intestinal/etiología , Obstrucción Intestinal/mortalidad , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Implantación de Prótesis/mortalidad , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento
13.
Mol Plant Microbe Interact ; 18(4): 343-53, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15828686

RESUMEN

Seven new genes controlled by the quorum-sensing signal molecule N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) have been identified in Erwinia carotovora subsp. carotovora. Using TnphoA as a mutagen, we enriched for mutants defective in proteins that could play a role in the interaction between E. carotovora subsp. carotovora and its plant hosts, and identified NipEcc and its counterpart in E. carotovora subsp. atroseptica. These are members of a growing family of proteins related to Nep1 from Fusarium oxysporum which can induce necrotic responses in a variety of dicotyledonous plants. NipEcc produced necrosis in tobacco, NipEca affected potato stem rot, and both affected virulence in potato tubers. In E. carotovora subsp. carotovora, nip was shown to be subject to weak repression by the LuxR family regulator, EccR, and may be regulated by the negative global regulator RsmA.


Asunto(s)
4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Homoserina/análogos & derivados , Homoserina/metabolismo , Pectobacterium carotovorum/genética , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Elementos Transponibles de ADN , Prueba de Complementación Genética , Datos de Secuencia Molecular , Mutagénesis , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia , Solanum tuberosum/genética
14.
Proc Natl Acad Sci U S A ; 101(30): 11105-10, 2004 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-15263089

RESUMEN

The bacterial family Enterobacteriaceae is notable for its well studied human pathogens, including Salmonella, Yersinia, Shigella, and Escherichia spp. However, it also contains several plant pathogens. We report the genome sequence of a plant pathogenic enterobacterium, Erwinia carotovora subsp. atroseptica (Eca) strain SCRI1043, the causative agent of soft rot and blackleg potato diseases. Approximately 33% of Eca genes are not shared with sequenced enterobacterial human pathogens, including some predicted to facilitate unexpected metabolic traits, such as nitrogen fixation and opine catabolism. This proportion of genes also contains an overrepresentation of pathogenicity determinants, including possible horizontally acquired gene clusters for putative type IV secretion and polyketide phytotoxin synthesis. To investigate whether these gene clusters play a role in the disease process, an arrayed set of insertional mutants was generated, and mutations were identified. Plant bioassays showed that these mutants were significantly reduced in virulence, demonstrating both the presence of novel pathogenicity determinants in Eca, and the impact of functional genomics in expanding our understanding of phytopathogenicity in the Enterobacteriaceae.


Asunto(s)
Genoma Bacteriano , Pectobacterium carotovorum/genética , Pectobacterium carotovorum/patogenicidad , Enfermedades de las Plantas/microbiología , Solanum tuberosum/microbiología , Virulencia/genética , Secuencia de Bases , Evolución Biológica , Cartilla de ADN , Ambiente , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa
15.
Neurology ; 59(5): 759-61, 2002 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-12221173

RESUMEN

Children with neurofibromatosis 1 (NF1) often develop low-grade gliomas, but brain tumors are infrequently encountered in adults with NF1. The authors present evidence from two clinical series, one including patients known to have NF1 and another focusing on adults with new onset brain tumors, that suggests an association between NF1 and symptomatic gliomas in older individuals. They also summarize the clinical data on 17 adolescents or adults with NF1 and symptomatic gliomas. The findings suggest that individuals with NF1 are at increased risk of developing gliomas throughout their lives.


Asunto(s)
Neoplasias Encefálicas/epidemiología , Glioma/epidemiología , Neurofibromatosis 1/epidemiología , Adolescente , Adulto , Edad de Inicio , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo
16.
Cancer Causes Control ; 13(2): 183-9, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11936825

RESUMEN

OBJECTIVE: To investigate whether there was an increased incidence of solid tumors among offspring of male radiation workers at the Sellafield nuclear installation in Cumbria, northwest England and whether paternal preconceptional irradiation was associated with the risk of solid tumors. METHODS: A cohort study of 266,710 live births in Cumbria, 1950-1991, followed up to age 25 years on the end of 1991. RESULTS: Children of radiation workers had a non-significantly increased risk of solid tumors (RR= 1.5, 95% CI: 0.9-2.4, p = 0.09), determined largely by an increased risk of cancers excluding leukemias, lymphomas, brain, spinal and gender-specific tumors (RR= 1.9, 95% CI: 1.0-3.3, p = 0.05), which was partly explained by differing patterns of parental migration (adjusted RR= 1.7, 95% Cl: 0.8-3.2, p = 0.50). Within children of radiation workers there was no evidence of an increased risk with increasing paternal preconception dose of external radiation (hazard ratio per 100 mSv for all solid tumors=0.6, 95% CI: 0.1-1.8, p = 0.52). CONCLUSIONS: Any observed excess of solid tumors in children of radiation workers may be partly explained by population mixing. Fathers' occupational exposure to radiation before conception was not found to be risk factor for solid tumors in their children.


Asunto(s)
Neoplasias/etiología , Exposición Profesional , Exposición Paterna , Centrales Eléctricas , Sistema de Registros , Adolescente , Adulto , Niño , Protección a la Infancia , Preescolar , Estudios de Cohortes , Inglaterra/epidemiología , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Neoplasias/epidemiología , Dinámica Poblacional , Medición de Riesgo
17.
Mol Genet Genomics ; 266(2): 289-95, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11683271

RESUMEN

The oomycete plant pathogen Phytophthora infestans is the causal agent of late blight, one of the most devastating diseases of potato worldwide. As part of efforts to clone avirulence (Avr) genes and pathogenicity factors from P. infestans, we have constructed a bacterial artificial chromosome (BAC) library from an isolate containing six Avr genes. The BAC library comprises clones with an average insert size of 98 kb and represents an estimated 10 genome equivalents. A three-dimensional pooling strategy was developed to screen the BAC library for amplified fragment length polymorphism (AFLP) markers, as this type of marker has been extensively used in construction of a P. infestans genetic map. Multiple positive clones were identified for each AFLP marker tested. The pools were used to construct a contig of 11 BAC clones in a region of the P. infestans genome containing a cluster of three avirulence genes. The BAC contig is predicted to encompass the Avr11 locus but mapping of the BAC ends will be required to determine if the Avr3 and Avr10 loci are also present in the BAC contig. These results are an important step towards the positional cloning of avirulence genes from P. infestans, and the BAC library represents a valuable resource for largescale studies of oomycete genome organisation and gene content.


Asunto(s)
ADN/genética , Phytophthora/genética , Cromosomas Artificiales Bacterianos/genética , Clonación Molecular , Mapeo Contig , Biblioteca Genómica , Hibridación de Ácido Nucleico , Mapeo Físico de Cromosoma , Phytophthora/patogenicidad , Virulencia/genética
18.
Science ; 292(5520): 1348-53, 2001 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-11359005

RESUMEN

We analyzed photometric measurements and images of comet C/LINEAR before perihelion and after its breakup. Results from our photometry data include a lower limit of 0.44 kilometer for the radius of the nucleus before breakup, and a determination that it was depleted in carbon-chain molecules relative to most other comets. Our imaging and modeling results, which include a constraint on the rotational state of the nucleus, indicate that the disintegration likely started on 18 or 19 July 2000. The total mass detectable in the dust tail after the breakup was 3 x 10(8) kilograms, comparable to one of the fragments in the Hubble Space Telescope images; we therefore infer that most of the comet's original mass is hidden in remnants between 1 millimeter and 50 meters in diameter.

19.
J Epidemiol Community Health ; 55(6): 414-22, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11351000

RESUMEN

STUDY OBJECTIVE: To assess the completeness and accuracy of notification of cancers by the National Health Service Central Register (NHSCR) for England and Wales. DESIGN: Comparison of 720 cancer registrations ascertained from NHSCR up to May 1999 with those ascertained for the same cohort from six other sources and a pathology review of the NHSCR cancer registrations. PARTICIPANTS: People born in Cumbria, north west England, 1950-89, and diagnosed with cancer throughout the UK, 1971-1989. MAIN RESULTS: Cancer diagnoses notified by NHSCR differed substantially from those determined by this pathology review for 47 of the 688 notified cases reviewed (7%; 95% CI 5%, 9%). Over one third of these discrepancies were attributable to failures in data capture or coding by the cancer registration system and almost half to changes in diagnosis; 26 of the 47 discrepant cases were reclassified as non-malignant and 21 as malignancies but with a substantially different diagnosis. The 694 confirmed malignancies represented 94% (95%CI 92%, 95%) of the 740 cancers ascertained from all sources. CONCLUSIONS: It is estimated that the cancer registration system missed at least 10% (95%CI 6%, 15%) of all incident cases of malignant disease. Without additional ascertainment from multiple sources and diagnostic review, it would be incautious to use NHSCR cancer registrations as the sole basis of an epidemiological study.


Asunto(s)
Neoplasias/epidemiología , Sistema de Registros/normas , Adolescente , Adulto , Distribución por Edad , Anciano , Niño , Preescolar , Grupos Diagnósticos Relacionados , Inglaterra/epidemiología , Femenino , Humanos , Lactante , Recién Nacido , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neoplasias/diagnóstico , Medicina Estatal , Gales/epidemiología
20.
Mol Plant Pathol ; 2(5): 257-63, 2001 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-20573013

RESUMEN

UNLABELLED: summary Phytophthora infestans, cause of late-blight, is the most devastating disease of potato world-wide. Recent years have seen a dramatic intensification in molecular biological studies of P. infestans, including the development of novel tools for transformation and gene silencing and the resources for genetical, transcriptional and physical mapping of the genome. This review will focus on the increasing efforts to use these resources to discover the genetic bases of pathogenicity, avirulence and host-specificity. TAXONOMY: Phytophthora infestans (Mont.) de Bary-Kingdom Chromista, Phylum Oomycota, Order Peronosporales, Family Peronosporaceae, Genus Phytophthora, of which it is the type species. HOST RANGE: Infects a wide range of solanaceous species. Economically important hosts are potato, tomato, eggplant and some other South American hosts (tree tomato and pear melon) on which it causes late blight. Disease symptoms: Infected foliage is initially yellow, becomes water soaked and eventually blackens. Leaf symptoms comprise purple-black or brown-black lesions at the leaf tip, later spreading across the leaf to the stem. Whitish masses of sporangia develop on the underside of the leaf. Tubers become infected later in the season and, in the early stages, consist of slightly brown or purple blotches on the skin. In damp soils the tuber decays rapidly before harvest. Tuber infection is quickly followed by secondary fungal or bacterial infection known as 'wet rot'. Useful web sites:http://www.ncgr.org/pgc/; http://www.oardc.ohio-state.edu/phytophthora/.

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