Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Child Care Health Dev ; 41(1): 67-75, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24827413

RESUMO

BACKGROUND: Long-term childhood conditions are often managed by hospital-based multidisciplinary teams (MDTs) of professionals with discipline specific expertise of a condition, in partnership with parents. However, little evidence exists on professional-parent interactions in this context. An exploration of professionals' accounts of the way they individually and collectively teach parents to manage their child's clinical care at home is, therefore, important for meeting parents' needs, informing policy and educating novice professionals. Using chronic kidney disease as an exemplar this paper reports on one aspect of a study of interactions between professionals and parents in a network of 12 children's kidney units in Britain. METHODS: We conducted semi-structured, qualitative interviews with a convenience sample of 112 professionals (clinical-psychologists, dietitians, doctors, nurses, pharmacists, play-workers, therapists and social workers), exploring accounts of their parent-educative activity. We analysed data using framework and the concept of distributed expertise. RESULTS: Four themes emerged that related to the way expertise was distributed within and across teams: (i) recognizing each other's' expertise, (ii) sharing expertise within the MDT, (iii) language interpretation, and (iv) acting as brokers. Two different professional identifications were also seen to co-exist within MDTs, with participants using the term 'we' both as the intra-professional 'we' (relating to the professional identity) when describing expertise within a disciplinary group (for example: 'As dietitians we aim to give tailored advice to optimize children's growth'), and the inter-professional 'we' (a 'team-identification'), when discussing expertise within the team (for example: 'We work as a team and make sure we're all happy with every aspect of their training before they go home'). CONCLUSIONS: This study highlights the dual identifications implicit in 'being professional' in this context (to the team and to one's profession) as well as the unique role that each member of a team contributes to children's care. Our methodology and results have the potential to be transferred to teams managing other conditions.


Assuntos
Pais/educação , Equipe de Assistência ao Paciente/organização & administração , Relações Profissional-Família , Insuficiência Renal Crônica/terapia , Atitude do Pessoal de Saúde , Criança , Humanos , Relações Interprofissionais , Entrevistas como Assunto , Pais/psicologia , Equipe de Assistência ao Paciente/normas , Pesquisa Qualitativa , Insuficiência Renal Crônica/fisiopatologia , Apoio Social , Reino Unido
2.
Theor Appl Genet ; 118(2): 371-84, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18953524

RESUMO

The rice genome has proven a valuable resource for comparative approaches to address individual genomic regions in Triticeae species at the molecular level. To exploit this resource for rye genetics and breeding, an inventory was made of EST-derived markers with known genomic positions in rye, which were related with those in rice. As a first inventory set, 92 EST-SSR markers were mapped which had been drawn from a non-redundant rye EST collection representing 5,423 unigenes and 2.2 Mb of DNA. Using a BC1 mapping population which involved an exotic rye accession as donor parent, these EST-SSR markers were arranged in a linkage map together with 25 genomic SSR markers as well as 131 AFLP and four STS markers. This map comprises seven linkage groups corresponding to the seven rye chromosomes and covers 724 cM of the rye genome. For comparative studies, additional inventory sets of EST-based markers were included which originated from the rye-mapping data published by other authors. Altogether, 502 EST-based markers with known chromosomal localizations in rye were used for BlastN search and 334 of them could be in silico mapped in the rice genome. Additionally, 14 markers were included which lacked sequence information but had been genetically mapped in rice. Based on the 348 markers, each of the seven rye chromosomes could be aligned with distinct portions of the rice genome, providing improved insight into the status of the rye-rice genome relationships. Furthermore, the aligned markers provide genomic anchor points between rye and rice, enabling the identification of conserved ortholog set markers for rye. Perspectives of rice as a model for genome analysis in rye are discussed.


Assuntos
DNA de Plantas/química , Genômica/métodos , Secale/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Etiquetas de Sequências Expressas , Marcadores Genéticos , Genoma de Planta , Repetições Minissatélites , Oryza/genética , Análise de Sequência de DNA
3.
Theor Appl Genet ; 117(4): 641-52, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18535814

RESUMO

Genetic diversity of elite breeding material can be increased by introgression of exotic germplasm to ensure long-term selection response. The objective of our study was to develop and characterize the first two rye introgression libraries generated by marker-assisted backcrossing and demonstrate their potential application for improving the baking quality of rye. Starting from a cross between inbred line L2053-N (recurrent parent) and a heterozygous Iranian primitive population Altevogt 14160 (donor) two backcross (BC) and three selfing generations were performed to establish introgression libraries A and B. Amplified fragment length polymorphisms (AFLP markers) and simple sequences repeats (SSRs) were employed to select and characterize candidate introgression lines (pre-ILs) from BC(1) to BC2S3. The two introgression libraries comprise each 40 BC2S3 pre-ILs. For analyzing the phenotypic effects of the exotic donor chromosome segment (DCS) we evaluated the per se performance for pentosan and starch content in replicated field trials at each of four locations in 2005 and 2006. Introgression library A and B cover 74 and 59% of the total donor genome, respectively. The pre-ILs contained mostly two to four homozygous DCS, with a mean length of 12.9 cM (A) and 10.0 cM (B). We detected eight (A) and nine (B) pre-ILs with a significant (P<0.05) higher pentosan content and two pre-ILs (B) with a significant (P<0.05) higher starch content than the elite recurrent parent. Thus, our results indicate that exotic genetic resources in rye carry favorable alleles for baking quality traits, which can be exploited for improving the elite breeding material by marker-assisted selection (MAS). These introgression libraries can substantially foster rye breeding programs and provide a promising opportunity to proceed towards functional genomics.


Assuntos
Biblioteca Gênica , Genoma de Planta , Secale/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Cruzamento , Mapeamento Cromossômico , Marcadores Genéticos , Genômica , Hibridização Genética , Irã (Geográfico) , Repetições Minissatélites
4.
Cochrane Database Syst Rev ; (3): CD001935, 2006 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-16855980

RESUMO

BACKGROUND: Otitis media with effusion (OME) is common and may cause hearing loss with associated developmental delay. Treatment remains controversial. OBJECTIVES: To examine evidence for or against treating children with hearing loss associated with OME with systemic or topical intranasal steroids. SEARCH STRATEGY: We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library Issue 4 2005, MEDLINE (1966 to 2006), EMBASE (1974 to 2006), and the CINAHL, LILACS, Zetoc, IndMED, SAMED, KoreaMed, MEDCARIB and Cambridge Scientific Abstracts databases in January 2006. SELECTION CRITERIA: Randomised controlled trials of oral and topical intranasal steroids, either alone or in combination with another agent such as an antibiotic, were included. EXCLUSIONS: publications in abstract form only; uncontrolled, non-randomised or retrospective studies; studies reporting outcomes with ears (rather than children). DATA COLLECTION AND ANALYSIS: Data were extracted from the published reports by the authors independently using standardised data extraction forms and methods. The methodological quality of the included studies was independently assessed by the authors as described in the Cochrane Handbook. Dichotomous results were expressed as an odds ratio using a fixed-effect model together with the 95% confidence intervals. Continuous data were analysed using the weighted mean difference in a fixed-effect model. Tests for heterogeneity between studies were performed using a Mantel-Haenszel approach. In trials with a cross-over design, post cross-over treatment data were not used. MAIN RESULTS: No study prospectively documented hearing loss associated with OME prior to randomisation. Follow up was mainly short term. The odds ratio for OME persisting after short-term follow up in children treated with oral steroids compared to control was 0.22 (95% CI 0.08 to 0.63). The odds ratio for OME persisting after short-term follow up for children treated with oral steroids plus antibiotic compared to control plus antibiotic was 0.37 (95% CI 0.25 to 0.56). However, there was significant heterogeneity between studies included in the latter comparison (P < 0.01). Trends favoured steroids for most other comparisons, but confidence intervals included unity. There was no evidence of benefit for steroid treatment for OME or hearing loss associated with OME in the longer term. AUTHORS' CONCLUSIONS: Both oral and topical intranasal steroids alone or in combination with an antibiotic lead to a quicker resolution of OME in the short term, however, there is no evidence of longer term benefit.


Assuntos
Surdez/tratamento farmacológico , Glucocorticoides/administração & dosagem , Otite Média com Derrame/tratamento farmacológico , Administração Intranasal , Administração Oral , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Criança , Surdez/etiologia , Glucocorticoides/efeitos adversos , Humanos , Otite Média com Derrame/complicações , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Theor Appl Genet ; 107(4): 661-6, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12819909

RESUMO

Epidemics of powdery mildew due to Leveillula taurica is an increasing problem in pepper production areas, particularly in coastal regions or greenhouse cultivation. The highly resistant genitor 'H3' was submitted to genetic analysis and QTL mapping in order to promote the introgression of its oligogenic resistance into large and sweet-fruited cultivars. The doubled-haploid progeny from the cross 'H3' (resistant) by 'Vania' (susceptible) was tested for resistance under both natural field infection and artificial inoculation tests, and QTL detection was compared for those two methods. Seven genomic regions including additive QTLs and epistatic interactions were detected, explaining altogether the major part of genotypic variance. Two genomic regions were common to both the evaluation methods, whereas other QTLs were method-specific, reflecting the environment dependence of powdery mildew epidemics. Orthologies with tomato genomic regions carrying resistance genes to L. taurica and Oidium lycopersicum were revealed by comparative mapping with pepper. Tight linkages between the detected QTLs and virus resistance or fruit color traits in pepper were also shown, which adds to the agronomic importance of these regions in pepper breeding programs.


Assuntos
Ascomicetos/patogenicidade , Capsicum/genética , Capsicum/microbiologia , Cruzamento , Mapeamento Cromossômico , Genes de Plantas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Locos de Características Quantitativas
6.
Theor Appl Genet ; 106(8): 1524-31, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12750796

RESUMO

Nine resistance gene homologues (RGHs) were identified in two diploid potato clones (SH and RH), with a specific primer pair based on conserved motifs in the LRR domain of the potato cyst nematode resistance gene Gpa2 and the potato virus X resistance gene Rx1. A modified AFLP method was used to facilitate the genetic mapping of the RGHs in the four haplotypes under investigation. All nine RGHs appeared to be located in the Gpa2/ Rx1 cluster on chromosome XII. Construction of a physical map using bacterial artificial chromosome (BAC) clones for both the Solanum tuberosum ssp. tuberosum and the S. tuberosum ssp. andigena haplotype of SH showed that the RGHs are located within a stretch of less than 200 kb. Sequence analysis of the RGHs revealed that they are highly similar (93 to 95%) to Gpa2 and Rx1. The sequence identities among all RGHs range from 85 to 100%. Two pairs of RGHs are identical, or nearly so (100 and 99.9%), with each member located in a different genotype. Southern-blot analysis on genomic DNA revealed no evidence for additional homologues outside the Gpa2/ Rx1 cluster on chromosome XII.


Assuntos
Proteínas de Plantas/genética , Solanum tuberosum/genética , Sequência de Bases , Southern Blotting , Primers do DNA , Família Multigênica , Solanum tuberosum/parasitologia , Solanum tuberosum/virologia
7.
Arch Dis Child ; 87(6): 530-2, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12456556

RESUMO

AIMS: To determine: (1) whether children diagnosed with a urinary tract infection (UTI) visited their general practitioner (GP) more frequently before the diagnosis of UTI was established compared to children never diagnosed with a UTI; and (2) whether those children with evidence of renal scarring at their first diagnosed UTI visited their GPs more frequently before diagnosis compared to children who did not have evidence of renal scarring when their first UTI was investigated. METHODS: Case-control study of 77 children with a UTI identified from a hospital radiology database (37 with and 40 without renal scarring), and 77 age, sex, and general practice matched controls. Main outcome measures were entries in general practice clinical records for types of illness, antibiotic prescriptions, and urine samples requested prior to the diagnosis of first UTI (cases) or equivalent time periods for controls. RESULTS: Cases had a mean 2.94 additional visits or 21% more visits (95% CI 1% to 41%) in the period (mean 2.4 years) prior to the visit at which their first UTI was diagnosed, including a mean 2.5 additional visits or 23% more visits for infectious illness (95% CI 1% to 45%). The cases had 114% (95% CI 41% to 184%) more visits for symptoms relating to the genitourinary tract, though the actual number of these visits was small. They were febrile at 49% more visits (95% CI 1% to 99%) and received significantly more courses of antibiotics than controls (5.2 v 4.1). They had more urine samples requested (37 v 3). Both the cases with and without renal scarring had similar excess GP visits. CONCLUSION: Compared to controls, children diagnosed with a first UTI had more visits at which symptoms of infection were recorded and more antibiotics prescribed prior to the visit at which the first UTI was diagnosed. These excess visits may have included undiagnosed UTIs. Both those with and without renal scarring had a similar degree of excess visits; additional aetiological factors must have played a role in scar formation.


Assuntos
Medicina de Família e Comunidade , Aceitação pelo Paciente de Cuidados de Saúde , Infecções Urinárias/diagnóstico , Antibacterianos/uso terapêutico , Estudos de Casos e Controles , Pré-Escolar , Cicatriz/patologia , Feminino , Humanos , Rim/patologia , Masculino , Visita a Consultório Médico/estatística & dados numéricos , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/urina
8.
Cochrane Database Syst Rev ; (4): CD001935, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12519563

RESUMO

BACKGROUND: Otitis media with effusion (OME) is common and may cause hearing loss with associated developmental delay. Treatment remains controversial. The effectiveness of both systemic and topical intranasal steroids in promoting the resolution of effusions has been assessed by randomised controlled trials. OBJECTIVES: To examine evidence for or against treating children with hearing loss associated with OME with systemic or topical intranasal steroids. SEARCH STRATEGY: Searches were conducted in January 2002. We searched the Cochrane Controlled Trials Register using the terms 'otitis media', 'otitis media with effusion', 'glue ear', or 'OME', and 'steroids', 'glucocorticoids, synthetic', 'glucocorticoids, topical', 'anti-inflammatory agents, steroidal'. EMBASE and MEDLINE were also searched for additional information. SELECTION CRITERIA: Randomised controlled trials of oral and topical intranasal steroids, either alone or in combination with another agent such as an antibiotic, were included. EXCLUSIONS: publications in abstract form only since adequate appraisal was not possible; uncontrolled, non-randomised or retrospective studies; studies reporting outcomes with ears (rather than children) as the unit of analysis unless data were of sufficient detail to allow analysis by child. DATA COLLECTION AND ANALYSIS: Data were extracted from the published reports by the two authors independently (CCB and JH van der V) using standardised data extraction forms and methods. The methodological quality of the included studies was independently assessed by the two authors using the scheme described in the Cochrane Handbook. Dichotomous results were expressed as an odds ratio using a fixed effects model together with the 95% confidence intervals. Continuous data were analysed using the weighted mean difference in a fixed effects model. Tests for heterogeneity between studies were performed using a Mantel-Haenszel approach. In trials with a cross over design, post crossover treatment data were not used. MAIN RESULTS: No study prospectively documented hearing loss associated with OME prior to randomisation. Follow up was mainly short term. No serious or lasting adverse effects were reported in the six studies that did mention adverse effects. Most comparisons involved small numbers of subjects. The odds ratio for OME persisting after short term follow up in children treated with oral steroids compared to control was 0.22 (95% CI 0.08 to 0.63). The odds ratio for OME persisting after short term follow up for children treated with oral steroids plus antibiotic compared to control plus antibiotic was 0.32 (95% CI 0.20 to 0.52). However there was significant heterogeneity between studies included in the latter comparison (p<0.01). Trends favoured steroids for most other comparisons, but confidence intervals included unity. There was no evidence of benefit for steroid treatment for resolution of OME or of resolution of hearing loss associated with OME in the longer term. REVIEWER'S CONCLUSIONS: Both oral and topical intranasal steroids alone or in combination with an antibiotic lead to a quicker resolution of OME in the short term. However, there is no evidence of a long term benefit from treating OME effusions or associated hearing loss with either oral or topical intranasal steroids. No serious adverse events were reported in the six studies that presented data on adverse effects. Future studies should document hearing loss associated with OME before the start of study treatment. Follow up should be longer and ideally include health related quality of life and hearing assessments. Data should not be presented only with ears as the unit of analysis.


Assuntos
Surdez/tratamento farmacológico , Glucocorticoides/administração & dosagem , Otite Média com Derrame/tratamento farmacológico , Administração Intranasal , Administração Oral , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Criança , Surdez/etiologia , Glucocorticoides/efeitos adversos , Humanos , Otite Média com Derrame/complicações , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Arch Pediatr Adolesc Med ; 155(6): 641-7, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11386950

RESUMO

BACKGROUND: Otitis media with effusion (OME) is common and may cause hearing loss with associated delayed language development in children. Treatment remains controversial. OBJECTIVE: To examine evidence for or against treating OME with systemic or topical nasal steroids. DATA SOURCES: We searched the Cochrane Controlled Trials Register using the terms otitis media; otitis media with effusion; glue ear; or OME and steroids; glucocorticoids; glucocorticoids, synthetic; glucocorticoids, topical; or anti-inflammatory agents, steroidal; or various combinations of these terms. EMBASE and MEDLINE were also searched. STUDY SELECTION: Randomized controlled trials of oral and topical nasal steroids, either alone or in combination with another agent such as an antibiotic, were included. Ten studies met the inclusion criteria. DATA EXTRACTION: Data extraction and methodological quality assessment were performed by the 2 of us (C.C.B. and J.H.v.d.V.) independently, using standardized methods described in the Cochrane Collaboration Handbook. DATA SYNTHESIS: The odds ratio for OME persisting after short-term follow-up in children treated with oral steroids compared with a control was 0.22 (95% confidence interval, 0.08 = 0.63), and was 0.32 (95% confidence interval, 0.20 = 0.52) for children treated with oral steroids plus an antibiotic compared with a control plus an antibiotic. Trends favored steroids for most other comparisons, but confidence intervals included unity. Trends favored steroids for most other comparisons, but confidence intervals included unity. CONCLUSIONS: Steroids alone or combined with an antibiotic lead to a quicker resolution of OME in the short-term. However, there is no evidence for a long-term benefit from treating hearing loss associated with OME with either oral or topical nasal steroids. These treatments are, therefore, not recommended.


Assuntos
Otite Média com Derrame/tratamento farmacológico , Esteroides/uso terapêutico , Antibacterianos/uso terapêutico , Criança , Pré-Escolar , Intervalos de Confiança , Quimioterapia Combinada , Humanos , Lactente , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
10.
Phytopathology ; 91(8): 753-8, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18944032

RESUMO

To assess the genetic constitution of the Globodera pallida populations in the Netherlands and the effects of agricultural practices, three geographically separated metapopulations, in total consisting of 226 local populations, were analyzed by two-dimensional gel electrophoresis (2-DGE) of total proteins. This technique allows the accurate assessment of allele frequencies in homogenates of mixtures of individuals. Based on the estimated average heterozygosity, the average proportion of polymorphic loci and the average number of alleles per locus, the genetic diversity among 226 local G. pallida populations was small. The small genetic basis of G. pallida in the Netherlands will facilitate the identification of Solanum genotypes with a broad and durable resistance to G. pallida. Instead of clusters of local populations with unique alleles, a continuous range of allele frequencies was observed. Analysis of the three metapopulations by the Shannon-Weaver index and Nei's G(ST) revealed that the metapopulation from a region with sandy-loam soils was clearly distinguishable from the remaining two; the local populations within this metapopulation were more similar and the genetic diversity within the individual local populations was significantly higher than the local populations from the two remaining regions. These regions are characterized by wider crop rotation schemes and a very limited use of nematicides. The less intensive cultivation of potatoes in these regions with sandy-clay soils resulted in relatively little variation within and more variation between local nematode populations. To our knowledge, the effects of agricultural practices on the genetic constitution of potato cyst nematode populations have not been pinpointed before.

11.
Plant J ; 23(5): 567-76, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10972883

RESUMO

The isolation of the nematode-resistance gene Gpa2 in potato is described, and it is demonstrated that highly homologous resistance genes of a single resistance-gene cluster can confer resistance to distinct pathogen species. Molecular analysis of the Gpa2 locus resulted in the identification of an R-gene cluster of four highly homologous genes in a region of approximately 115 kb. At least two of these genes are active: one corresponds to the previously isolated Rx1 gene that confers resistance to potato virus X, while the other corresponds to the Gpa2 gene that confers resistance to the potato cyst nematode Globodera pallida. The proteins encoded by the Gpa2 and the Rx1 genes share an overall homology of over 88% (amino-acid identity) and belong to the leucine-zipper, nucleotide-binding site, leucine-rich repeat (LZ-NBS-LRR)-containing class of plant resistance genes. From the sequence conservation between Gpa2 and Rx1 it is clear that there is a direct evolutionary relationship between the two proteins. Sequence diversity is concentrated in the LRR region and in the C-terminus. The putative effector domains are more conserved suggesting that, at least in this case, nematode and virus resistance cascades could share common components. These findings underline the potential of protein breeding for engineering new resistance specificities against plant pathogens in vitro.


Assuntos
Família Multigênica , Nematoides/patogenicidade , Proteínas de Plantas/genética , Vírus de Plantas/patogenicidade , Solanum tuberosum/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Primers do DNA , Teste de Complementação Genética , Dados de Sequência Molecular , Nucleotídeos/genética , Proteínas de Plantas/química , Homologia de Sequência de Aminoácidos , Solanum tuberosum/parasitologia , Solanum tuberosum/virologia
12.
Pediatr Nephrol ; 14(8-9): 717-9, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10955914

RESUMO

DOQI guidelines recommend minimal standards for automated peritoneal dialysis (APD), with a weekly Kt/V of 2.1 and creatinine clearance (Ccr) of 63 l/1.73 m2. The purpose of this study was to assess if the DOQI guidelines could be met by dialysis alone in children on PD. Dialysis clearance studies were retrospectively analyzed in 20 pediatric patients on APD, all with a dwell volume of at least 1,000 ml/m2. Mean dialytic Kt/V was 2.0; only 45% had a Kt/V above the recommended 2.1. Mean dialytic Ccr was 43.5 l/week per 1.73 m2; only 10% achieved a Ccr above the recommended 63 l/week per 1.73 m2. Despite the significant correlation between total therapy volume (TTV) and both Kt/V and Ccr, only 2 of 10 patients with a TTV over 10 l/m2 per day reached the target Ccr. All patients had currently recommended dwell volumes, therapy times, and nocturnal cycles, but DOQI guidelines were difficult to achieve with dialysis alone. Strict adherence to DOQI guidelines in anephric pediatric PD patients may result in changing dialysis modality. However, without evidence of a correlation between delivered dose of dialysis and improved outcome, adequate dialysis should not be assessed by only measuring Kt/V and Ccr.


Assuntos
Diálise Peritoneal/normas , Canadá , Criança , Creatinina/metabolismo , Guias como Assunto , Humanos , Garantia da Qualidade dos Cuidados de Saúde , Estudos Retrospectivos
13.
Mol Plant Microbe Interact ; 13(8): 830-6, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10939254

RESUMO

A new strategy has been designed to identify putative pathogenicity factors from the dorsal or subventral esophageal glands of the potato cyst nematode Globodera rostochiensis. Three independent criteria were used for selection. First, genes of interest should predominantly be expressed in infective second-stage juveniles, and not, or to a far lesser extent, in younger developmental stages. For this, gene expression profiles from five different developmental stages were generated with cDNA-AFLP (amplified fragment length polymorphism). Secondly, the mRNA corresponding to such a putative pathogenicity factor should predominantly be present in the esophageal glands of pre-parasitic juveniles. This was checked by in situ hybridization. As a third criterion, these proteinaceous factors should be preceded by a signal peptide for secretion. Expression profiles of more than 4,000 genes were generated and three up-regulated, dorsal gland-specific proteins preceded by signal peptide for secretion were identified. No dorsal gland genes have been cloned before from plant-parasitic nematodes. The partial sequence of these three factors, A4, A18, and A41, showed no significant homology to any known gene. Their presence in the dorsal glands of infective juveniles suggests that these proteins could be involved in feeding cell initiation, and not in migration in the plant root or in protection against plant defense responses. Finally, the applicability of this new strategy in other plant-microbe interactions is discussed.


Assuntos
Nematoides/patogenicidade , Técnicas de Amplificação de Ácido Nucleico , Solanum tuberosum/parasitologia , Animais , Sequência de Bases , Primers do DNA , DNA Complementar , Hibridização In Situ , Dados de Sequência Molecular , Nematoides/genética , RNA Mensageiro/genética , Reprodutibilidade dos Testes
14.
Mol Plant Microbe Interact ; 12(10): 872-81, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10517027

RESUMO

Naturally induced secretions from infective juveniles of the potato cyst nematode Globodera rostochiensis co-stimulate the proliferation of tobacco leaf protoplasts in the presence of the synthetic phytohormones alpha-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP). With the use of a protoplast-based bioassay, a low-molecular-weight peptide(s) (< 3 kDa) was shown to be responsible for the observed effect. This mitogenic oligopeptide(s) is functionally dissimilar to auxin and cytokinin and, in addition, it does not change the sensitivity of the protoplasts toward these phytohormones. In combination with the mitogen phytohemagglutinin (PHA), cyst nematode secretions also co-stimulated mitogenesis in human peripheral blood mononuclear cells (PBMC). The stimulation of plant cells isolated from nontarget tissue--these nematodes normally invade the roots of potato plants--suggests the activation of a general signal transduction mechanism(s) by an oligopeptide(s) secreted by the nematode. Whether a similar oligopeptide-induced mechanism underlies human PBMC activation remains to be investigated. Reactivation of the cell cycle is a crucial event in feeding cell formation by cyst nematodes. The secretion of a mitogenic low-molecular-weight peptide(s) by infective juveniles of the potato cyst nematode could contribute to the redifferentiation of plant cells into such a feeding cell.


Assuntos
Adenina/análogos & derivados , Leucócitos Mononucleares/citologia , Ácidos Naftalenoacéticos/farmacologia , Nematoides/fisiologia , Nicotiana/citologia , Reguladores de Crescimento de Plantas/farmacologia , Plantas Tóxicas , Solanum tuberosum/parasitologia , Adenina/farmacologia , Animais , Compostos de Benzil , Divisão Celular , Humanos , Cinetina , Leucócitos Mononucleares/efeitos dos fármacos , Folhas de Planta , Protoplastos/efeitos dos fármacos , Protoplastos/fisiologia , Purinas , Nicotiana/efeitos dos fármacos , Nicotiana/fisiologia
15.
Mol Gen Genet ; 261(6): 1021-31, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10485294

RESUMO

A mapping strategy is described for the construction of a linkage map of a non-inbred species in which individual offspring genotypes are not amenable to marker analysis. After one extra generation of random mating, the segregating progeny was propagated, and bulked populations of offspring were analyzed. Although the resulting population structure is different from that of commonly used mapping populations, we show that the maximum likelihood formula for a normal F2 is applicable for the estimation of recombination. This "pseudo-F2" mapping strategy, in combination with the development of an AFLP assay for single cysts, facilitated the construction of a linkage map for the potato cyst nematode Globodera rostochiensis. Using 12 pre-selected AFLP primer combinations, a total of 66 segregating markers were identified, 62 of which were mapped to nine linkage groups. These 62 AFLP markers are randomly distributed and cover about 65% of the genome. An estimate of the physical size of the Globodera genome was obtained from comparisons of the number of AFLP fragments obtained with the values for Caenorhabditis elegans. The methodology presented here resulted in the first genomic map for a cyst nematode. The low value of the kilobase/centimorgan (kb/cM) ratio for the Globodera genome will facilitate map-based cloning of genes that mediate the interaction between the nematode and its host plant.


Assuntos
Ligação Genética , Nematoides/genética , Solanum tuberosum/parasitologia , Animais , Marcadores Genéticos , Genoma , Genótipo , Polimorfismo Genético , Recombinação Genética
16.
J Clin Pathol ; 50(7): 569-72, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9306937

RESUMO

BACKGROUND: Urinary tract infection in infancy continues to be underdiagnosed, despite its association with renal scarring and thus hypertension, renal failure, and other sequelae. Low ascertainment of urinary tract infections reflects the many difficulties in establishing a diagnosis, some of which could be eliminated by a simple, reliable method for preliminary investigation of children's urine. AIM: To assess the accuracy of a new, simple method for testing urine for nitrite and leucocyte esterase, which could be applied to children in primary care. METHODS: An in vitro study was carried out to compare the results of conventional urine analysis with urine analysis on urine soaked on to panty-liners, and with the laboratory investigation. Two urine analysis stick types were used (Boehringer Mannheim Nephur sticks and Bayer Multistix 8SG) and two brands of panty-liners. Analysis examined evidence of agreement and bias for different methods in addition to sensitivity, specificity, and negative predictive values for urine analysis. RESULTS: Pressing urine analysis test sticks on to panty-liners soaked with urine achieved consistent results compared with the results of conventional dipstick urine analysis. At a prevalence of 21.8%, sensitivity and negative predictive values of urine analysis for laboratory confirmed urinary tract infection were 94% and 98%, respectively, for Boehringer sticks, and 76% and 93%, respectively, for Bayer sticks. At prevalences of 5% and 1% (prevalences that could be expected in primary care) Bayer sticks had negative predictive values of 98.7% and 99.7%, respectively, and Boehringer sticks had values of 99.6% and 99.9%, respectively. CONCLUSIONS: Testing urine on panty-liners is accurate compared with conventional urine analysis. It may be possible to apply this method to testing unwell children presenting in primary care to identify those who require microbiological urine culture to confirm or eliminate a diagnosis of urinary tract infection.


Assuntos
Cuidado do Lactente , Urinálise/métodos , Infecções Urinárias/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/urina , Hidrolases de Éster Carboxílico/urina , Criança , Pré-Escolar , Humanos , Lactente , Pessoa de Meia-Idade , Nitritos/urina , Valor Preditivo dos Testes , Fitas Reagentes , Sensibilidade e Especificidade
17.
Mol Gen Genet ; 255(4): 438-47, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9267440

RESUMO

The allele specificity of AFLP markers was assessed in five relatively unrelated potato genotypes. To this end, two diploid mapping populations of potato, F1SH x RH and F1AM x RH, were analysed using four and six AFLP primer combinations, respectively, recently applied to the analysis of the genetically well characterized backcross population BC_C x E. The AFLP profiles of the five parents revealed 733 AFLP markers and, when identical primer combinations were used, 131 comigrating AFLP markers were identified. After construction of five parental maps, the genomic positions of these comigrating AFLP markers were compared and 117 markers (89%) which targeted the same genomic region were assumed to be homologous. Of these putative homologues, 20 markers, each cloned from at least two genotypes, were sequenced and 19 sets of amplification products were shown to be nearly identical. The number of AFLP markers previously mapped in population BC_C x E ranged from three to eleven per chromosome, which allowed a reliable assessment of chromosome numbers from individual linkage groups obtained in populations F1SH x RH and F1AM x RH. The high incidence of corresponding AFLP alleles was confirmed by using an additional set of five primer combinations. The 733 AFLP markers localized provide a valuable reference collection for future mapping studies in potato. As a consequence AFLP analysis may replace more laborious locus-specific marker techniques.


Assuntos
Mapeamento Cromossômico/métodos , Marcadores Genéticos , Solanum tuberosum/genética , Alelos , Primers do DNA , Homologia de Sequência do Ácido Nucleico
18.
Fam Pract ; 14(1): 44-8, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9061344

RESUMO

BACKGROUND: The incidence of urinary tract infection (UTI) in childhood is highest in infancy and accounts for 5% of febrile infants. Reflux nephropathy following UTI in early childhood is the commonest preventable cause of chronic renal failure. Recent guidelines aim to improve the diagnosis and management of UTI in small children. OBJECTIVES: To assess management of febrile children and UTI in children under 2 years amongst GPs, and to identify some reasons for the difficulties in diagnosing UTI. METHOD: Questionnaire distributed by periodical journal. RESULTS: Eighty-two GPs responded, of whom 61 (74%) were unaware of the recent Royal College of Physicians guidelines on childhood UTI. Seventy-seven GPs (94%) would find guidelines helpful on when to send a urine sample for culture from a child under 2 years. Only 11 GPs (14%) regularly sent urine from febrile infants and toddlers; 48 GPs (63%) sent urine from only 0-10% of patients; 21 (26%) were unable to collect urine at all from these children. Several difficulties were identified by GPs regarding investigation for UTI in children. These related to practical difficulties in urine collection and culturing, lack of professional awareness of the importance of UTI and concerns about the costs of investigation. CONCLUSION: GPs frequently do not investigate for UTI in febrile children due to practical difficulties, lack of awareness and financial costs. National guidelines need to be disseminated and implemented effectively to reach target groups. Further scope for research into a simple, cheap method to collect and test urine has been highlighted as a priority to improve early diagnosis of UTI. Management of UTI in primary care can be improved with carefully evaluated strategies and this could lead to a reduction in the prevalence of renal scarring.


Assuntos
Medicina de Família e Comunidade , Conhecimentos, Atitudes e Prática em Saúde , Padrões de Prática Médica , Infecções Urinárias/diagnóstico , Febre/diagnóstico , Febre/urina , Pesquisas sobre Atenção à Saúde , Humanos , Lactente , Irlanda , Reino Unido , Infecções Urinárias/urina
20.
Mol Plant Microbe Interact ; 9(1): 47-54, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8589422

RESUMO

AFLP was used to characterize 24 potato cyst nematode populations. This novel DNA fingerprinting technique enabled the identification of 987 marker loci by screening only 12 primer combinations. Data on presence or absence polymorphisms and data on the intensities of corresponding DNA fragments were collected. Separate analysis of both data sets revealed similar dendrograms for the nine G. rostochiensis populations included in this study. Both dendrograms consisted of two groups containing three and five related populations, respectively. One population differed from either of these groups. Each group represented a different pathotype as defined by Kort et al. (J. Kort, H. Ross, H. J. Rumpenhorst, and A. R. Stone, Nematologica 23:333-339, 1977). Previously, a similar arrangement was found after analysis of the genetic variation using random amplified polymorphic DNA (RAPD) (R. T. Folkertsma, J. N. A. M. Rouppe van der Voort, M. P. E. van Gent-Pelzer, K. E. de Groot, W. J. van den Bos, A. Schots, J. Bakker, and F. J. Gommers, Phytopathology 84:807-811, 1994). For the 15 G. pallida populations analyzed, complex AFLP patterns were obtained and therefore only qualitative AFLP data were used. Incongruities were observed between clustering on the basis of AFLP data and classical pathotyping. This strongly confirms earlier findings obtained with RAPDs, because the AFLP markers used in this study outnumbered the population characteristics revealed by RAPDs by a factor of five. To arrive at a reliable pathotype designation of potato cyst nematode populations molecular data and virulence characteristics should be integrated. Possible causes for the difference in distribution of polymorphisms among g. rostochiensis and G. pallida populations are discussed.


Assuntos
Impressões Digitais de DNA/métodos , Pool Gênico , Genes de Helmintos , Nematoides/genética , Polimorfismo Genético , Animais , Análise por Conglomerados , DNA de Helmintos , Genoma , Nematoides/classificação , Nematoides/patogenicidade , Reação em Cadeia da Polimerase , Solanum tuberosum/parasitologia , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...