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1.
Sci Adv ; 5(12): eaax3619, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-32064312

RESUMO

Genomes carry millions of noncoding variants, and identifying the tiny fraction with functional consequences is a major challenge for genomics. We assessed the role of selection on long noncoding RNAs (lncRNAs) for domestication-related changes in rice grains. Among 3363 lncRNA transcripts identified in early developing panicles, 95% of those with differential expression (329 lncRNAs) between Oryza sativa ssp. japonica and wild rice were significantly down-regulated in the domestication event. Joint genome and transcriptome analyses reveal that directional selection on lncRNAs altered the expression of energy metabolism genes during domestication. Transgenic experiments and population analyses with three focal lncRNAs illustrate that selection on these loci led to increased starch content and grain weight. Together, our findings indicate that genome-wide selection for lncRNA down-regulation was an important mechanism for the emergence of rice domestication traits.


Assuntos
Domesticação , Variação Genética , Genoma de Planta , Estudo de Associação Genômica Ampla , Genômica , Oryza/genética , Característica Quantitativa Herdável , RNA não Traduzido , Produtos Agrícolas , Grão Comestível , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genômica/métodos , Fenótipo
2.
Intensive care med ; 43(12)Dec. 2017. tab
Artigo em Inglês | BIGG - guias GRADE | ID: biblio-947327

RESUMO

OBJECTIVE: To update the 2008 consensus statements for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in adult and pediatric patients. PARTICIPANTS: A multispecialty task force of 16 international experts in Critical Care Medicine, endocrinology, and guideline methods, all of them members of the Society of Critical Care Medicine and/or the European Society of Intensive Care Medicine. DESIGN/METHODS: The recommendations were based on the summarized evidence from the 2008 document in addition to more recent findings from an updated systematic review of relevant studies from 2008 to 2017 and were formulated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The strength of each recommendation was classified as strong or conditional, and the quality of evidence was rated from high to very low based on factors including the individual study design, the risk of bias, the consistency of the results, and the directness and precision of the evidence. Recommendation approval required the agreement of at least 80% of the task force members. RESULTS: The task force was unable to reach agreement on a single test that can reliably diagnose CIRCI, although delta cortisol (change in baseline cortisol at 60 min of <9 µg/dl) after cosyntropin (250 µg) administration and a random plasma cortisol of <10 µg/dl may be used by clinicians. We suggest against using plasma free cortisol or salivary cortisol level over plasma total cortisol (conditional, very low quality of evidence). For treatment of specific conditions, we suggest using intravenous (IV) hydrocortisone <400 mg/day for ≥3 days at full dose in patients with septic shock that is not responsive to fluid and moderate- to high-dose vasopressor therapy (conditional, low quality of evidence). We suggest not using corticosteroids in adult patients with sepsis without shock (conditional recommendation, moderate quality of evidence). We suggest the use of IV methylprednisolone 1 mg/kg/day in patients with early moderate to severe acute respiratory distress syndrome (PaO2/FiO2 < 200 and within 14 days of onset) (conditional, moderate quality of evidence). Corticosteroids are not suggested for patients with major trauma (conditional, low quality of evidence). CONCLUSIONS: Evidence-based recommendations for the use of corticosteroids in critically ill patients with sepsis and septic shock, acute respiratory distress syndrome, and major trauma have been developed by a multispecialty task force.


Assuntos
Humanos , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Choque Séptico/tratamento farmacológico , Metilprednisolona/uso terapêutico , Corticosteroides/administração & dosagem , Sepse/tratamento farmacológico , Hidrocortisona/administração & dosagem , Metilprednisolona/administração & dosagem , Estado Terminal , Insuficiência Adrenal/tratamento farmacológico , Síndrome de Resposta Inflamatória Sistêmica/tratamento farmacológico
3.
Curr Top Dev Biol ; 119: 63-109, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27282024

RESUMO

Crop domestication provides a useful model system to characterize the molecular and developmental bases of morphological variation in plants. Among the most universal changes resulting from selection during crop domestication is the loss of seed and fruit dispersal mechanisms, which greatly facilitates harvesting efficiency. In this review, we consider the molecular genetic and developmental bases of the loss of seed shattering and fruit dispersal in six major crop plant families, three of which are primarily associated with seed crops (Poaceae, Brassicaceae, Fabaceae) and three of which are associated with fleshy-fruited crops (Solanaceae, Rosaceae, Rutaceae). We find that the developmental basis of the loss of seed/fruit dispersal is conserved in a number of independently domesticated crops, indicating the widespread occurrence of developmentally convergent evolution in response to human selection. With regard to the molecular genetic approaches used to characterize the basis of this trait, traditional biparental quantitative trait loci mapping remains the most commonly used strategy; however, recent advances in next-generation sequencing technologies are now providing new avenues to map and characterize loss of shattering/dispersal alleles. We anticipate that continued application of these approaches, together with candidate gene analyses informed by known shattering candidate genes from other crops, will lead to a rapid expansion of our understanding of this critical domestication trait.


Assuntos
Produtos Agrícolas , Domesticação , Frutas , Sementes , Brassicaceae/fisiologia , Produtos Agrícolas/genética , Fabaceae/fisiologia , Frutas/genética , Poaceae/fisiologia , Sementes/genética , Seleção Genética
4.
J Evol Biol ; 27(11): 2554-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25146520

RESUMO

Identifying the genetic basis of parallel phenotypic evolution provides insight into the process of adaptation and evolutionary constraint. White clover (Trifolium repens) has evolved climate-associated adaptive clines in cyanogenesis (the ability to produce hydrogen cyanide upon tissue damage) in several world regions where it has been introduced. Gene-deletion polymorphisms at the CYP79D15 and Li loci underlie the presence/absence of the cyanogenic phenotype. Both loci have undergone multiple independent gene-deletion events, which are identifiable through molecular signatures in flanking regions. To investigate whether cyanogenesis clines in introduced populations have evolved through the sorting of standing genetic variation or de novo gene deletions, we examined cyanogenesis gene-flanking regions in three world regions. In comparison with native Eurasian populations, we find no evidence for novel gene deletion events in any introduced region, which suggests that these adaptive clines have evolved through the geographical sorting of pre-existing genetic variation.


Assuntos
Cianeto de Hidrogênio/metabolismo , Trifolium/genética , Trifolium/fisiologia , Adaptação Fisiológica/genética , Evolução Biológica , Sistema Enzimático do Citocromo P-450/genética , Deleção de Genes , Genes de Plantas , Variação Genética , Genética Populacional , Polimorfismo Genético , beta-Glucosidase/genética
5.
Heredity (Edinb) ; 111(6): 495-504, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23900395

RESUMO

The recurrent evolution of adaptive clines within a species can be used to elucidate the selective factors and genetic responses that underlie adaptation. White clover is polymorphic for cyanogenesis (HCN release with tissue damage), and climate-associated cyanogenesis clines have evolved throughout the native and introduced species range. This polymorphism arises through two independently segregating Mendelian polymorphisms for the presence/absence of two required components: cyanogenic glucosides and their hydrolyzing enzyme linamarase. Cyanogenesis is commonly thought to function in herbivore defense; however, the individual cyanogenic components may also serve other physiological functions. To test whether cyanogenesis clines have evolved in response to the same selective pressures acting on the same genetic targets, we examined cyanogenesis cline shape and its environmental correlates in three world regions: southern New Zealand, the central United States and the US Pacific Northwest. For some regional comparisons, cline shapes are remarkably similar despite large differences in the spatial scales over which clines occur (40-1600 km). However, we also find evidence for major differences in both the agents and targets of selection among the sampled clines. Variation in cyanogenesis frequency is best predicted using a combination of minimum winter temperature and aridity variables. Together, our results provide evidence that recurrent adaptive clines do not necessarily reflect shared adaptive processes.


Assuntos
Seleção Genética , Trifolium/genética , Adaptação Fisiológica , Evolução Biológica , Geografia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Trifolium/enzimologia , beta-Glucosidase/genética , beta-Glucosidase/metabolismo
6.
J Evol Biol ; 26(8): 1738-49, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23859433

RESUMO

The two independent domestication events in the genus Oryza that led to African and Asian rice offer an extremely useful system for studying the genetic basis of parallel evolution. This system is also characterized by parallel de-domestication events, with two genetically distinct weedy rice biotypes in the US derived from the Asian domesticate. One important trait that has been altered by rice domestication and de-domestication is hull colour. The wild progenitors of the two cultivated rice species have predominantly black-coloured hulls, as does one of the two U.S. weed biotypes; both cultivated species and one of the US weedy biotypes are characterized by straw-coloured hulls. Using Black hull 4 (Bh4) as a hull colour candidate gene, we examined DNA sequence variation at this locus to study the parallel evolution of hull colour variation in the domesticated and weedy rice system. We find that independent Bh4-coding mutations have arisen in African and Asian rice that are correlated with the straw hull phenotype, suggesting that the same gene is responsible for parallel trait evolution. For the U.S. weeds, Bh4 haplotype sequences support current hypotheses on the phylogenetic relationship between the two biotypes and domesticated Asian rice; straw hull weeds are most similar to indica crops, and black hull weeds are most similar to aus crops. Tests for selection indicate that Asian crops and straw hull weeds deviate from neutrality at this gene, suggesting possible selection on Bh4 during both rice domestication and de-domestication.


Assuntos
Evolução Biológica , Oryza/genética , Pigmentação/genética , Variação Genética , Filogenia , Seleção Genética
7.
Heredity (Edinb) ; 110(4): 303-11, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23188175

RESUMO

Weeds are among the greatest pests of agriculture, causing billions of dollars in crop losses each year. As crop field management practices have changed over the past 12 000 years, weeds have adapted in turn to evade human removal. This evolutionary change can be startlingly rapid, making weeds an appealing system to study evolutionary processes that occur over short periods of time. An understanding of how weeds originate and adapt is needed for successful management; however, relatively little emphasis has been placed on genetically characterizing these systems. Here, we review the current literature on agricultural weed origins and their mechanisms of adaptation. Where possible, we have included examples that have been genetically well characterized. Evidence for three possible, non-mutually exclusive weed origins (from wild species, crop-wild hybrids or directly from crops) is discussed with respect to what is known about the microevolutionary signatures that result from these processes. We also discuss what is known about the genetic basis of adaptive traits in weeds and the range of genetic mechanisms that are responsible. With a better understanding of genetic mechanisms underlying adaptation in weedy species, we can address the more general process of adaptive evolution and what can be expected as we continue to apply selective pressures in agroecosystems around the world.


Assuntos
Adaptação Biológica/genética , Evolução Biológica , Plantas Daninhas/genética , Zea mays/genética , Adaptação Biológica/fisiologia , Produtos Agrícolas/genética , Herbicidas , Humanos , Plantas Daninhas/classificação , Plantas Daninhas/fisiologia , Zea mays/parasitologia , Zea mays/fisiologia
8.
J Evol Biol ; 23(12): 2747-53, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21121088

RESUMO

Repeated phenotypic evolution can occur at both the inter- and intraspecific level and is especially prominent in domesticated plants, where artificial selection has favoured the same traits in many different species and varieties. The question of whether repeated evolution reflects changes at the same or different genes in each lineage can now be addressed using the domestication and improvement genes that have been identified in a variety of crops. Here, we document the genetic basis of nonpigmented ('white') pericarps in domesticated African rice (Oryza glaberrima) and compare it with the known genetic basis of the same trait in domesticated Asian rice (Oryza sativa). In some cases, white pericarps in African rice are apparently caused by unique mutations at the Rc gene, which also controls pericarp colour variation in Asian rice. In one case, white pericarps appear to reflect changes at a different gene or potentially a cis-regulatory region.


Assuntos
Genes de Plantas , Mutação , Oryza/genética , Fenótipo , Filogenia , Sequência de Aminoácidos , Cor , Análise Mutacional de DNA , Dados de Sequência Molecular , Oryza/anatomia & histologia , Sementes/anatomia & histologia , Sementes/genética , Alinhamento de Sequência
9.
J Econ Entomol ; 102(2): 708-16, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19449653

RESUMO

Bollgard II cotton (which expresses two Bt insecticidal genes cry1Ac/cry2Ab) and conventional cotton, grown in the laboratory or field and sampled at different stages, was exposed to Helicoverpa armigera (Hübner) larvae of three genotypes: homozygous for resistance to Cry2Ab; homozygous for susceptibility to Cry2Ab, and heterozygous for resistance. Survival of all genotypes was limited on Bollgard II but increased as plants aged. This was particularly the case for homozygous resistant individuals, with 8.5% of this genotype surviving to pupation on mature cotton. The increasing survival is assumed to be caused by the decline in the titer of Cry1Ac toxin after flowering in Bollgard II because Cry2Ab homozygous resistant larvae can tolerate high levels of Cry2Ab toxin. Larvae heterozygous for resistance performed no better on Bollgard II than homozygous susceptible larvae. Survivors on Bollgard II grew more slowly and produced smaller pupae that yielded adults with reduced longevity and fecundity. When reared on conventional cotton, all genotypes generally performed equally, indicating an absence of fitness costs associated with Cry2Ab resistance under the conditions examined.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Endotoxinas/genética , Endotoxinas/farmacologia , Gossypium/genética , Gossypium/parasitologia , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacologia , Resistência a Inseticidas/genética , Mariposas/efeitos dos fármacos , Animais , Toxinas de Bacillus thuringiensis , Comportamento Alimentar , Genótipo , Larva/genética , Mariposas/genética , Folhas de Planta/química , Plantas Geneticamente Modificadas , Fatores de Tempo
10.
Aliment Pharmacol Ther ; 28(3): 326-33, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19086331

RESUMO

BACKGROUND: While proton pump inhibitors are frequently administered in the intensive care unit, the pharmacodynamic response of acid suppression between the enteral and intravenous (IV) route is unknown. AIM: To compare the pharmacodynamic response between enteral and IV lansoprazole in intensive care unit patients requiring stress ulcer prophylaxis therapy. METHODS: Adult mechanically ventilated patients were randomized to receive 72 h of daily enteral [lansoprazole oral disintegrating tablet (LODT) 30 mg mixed in 10 mL of water via a nasal gastric tube] or IV lansoprazole (30 mg over 30 min) therapy. Serial blood samples were collected after the first and third dose and analysed for pharmacokinetic parameters. Pharmacodynamic determination of intragastric pHmetry began prior to the first dose and continued for 72 h using a single channel pH microelectrode. RESULTS: Nineteen intensive care unit patients were randomized [LODT (n = 10); IV-L (n = 9)]. LODT bioavailability was 76%. LODT maintained gastric pH > 4 longer than IV-L at both 24 h (7.4 vs. 5.9 h; P = 0.039) and 72 h (10.4 and 8.9 h; P = 0.046) and resulted in a greater average pH over the first 24 h (3.67 vs. 2.89; P = 0.03). CONCLUSION: Despite a lower bioavailability, enteral lansoprazole suppresses acid in intensive care unit patients to a greater extent than IV lansoprazole.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/farmacocinética , Antiulcerosos/farmacocinética , Refluxo Gastroesofágico/tratamento farmacológico , Inibidores da Bomba de Prótons/farmacocinética , Úlcera Gástrica/tratamento farmacológico , 2-Piridinilmetilsulfinilbenzimidazóis/administração & dosagem , Antiulcerosos/administração & dosagem , Estado Terminal/terapia , Vias de Administração de Medicamentos , Feminino , Determinação da Acidez Gástrica , Humanos , Unidades de Terapia Intensiva , Intubação Gastrointestinal/métodos , Lansoprazol , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inibidores da Bomba de Prótons/administração & dosagem , Resultado do Tratamento
11.
J Econ Entomol ; 101(3): 909-14, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18613594

RESUMO

Alleles conferring resistance to Cry2Ab toxin occur at a frequency of 0.0033 in Australian populations of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), and it is evident that detectable levels of resistance predated the introduction of transgenic cotton expressing this toxin. From 2002 until 2006, 10 such resistant alleles were scored. Here, we examine colonies established from five of the 10 isolates by using complementation tests to determine their genetic relationships. The results demonstrate that the resistance in each colony is due to alleles at the same locus and that for each allele the resistance is recessive. This latter finding is in conflict with the frequency of apparently resistant individuals occurring in the initial F2 tests that were used to identify alleles that confer resistance. These frequencies were variable (range 6.7-35.6%, mean 16.2%), but they generally indicated a measure of dominance (i.e., were >6.25% expected for recessive resistance). We hypothesize that this conflict is the result of differences in the genetic background of the laboratory adapted resistant colonies and the initial field isolations.


Assuntos
Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Resistência a Inseticidas , Inseticidas/farmacologia , Lepidópteros/efeitos dos fármacos , Animais , Austrália , Toxinas de Bacillus thuringiensis , Controle Biológico de Vetores
12.
Mol Ecol ; 16(19): 4180-93, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17784921

RESUMO

White clover (Trifolium repens) is naturally polymorphic for cyanogenesis (hydrogen cyanide release following tissue damage). The ecological factors favouring cyanogenic and acyanogenic plants have been examined in numerous studies over the last half century, making this one of the best-documented examples of an adaptive polymorphism in plants. White clover cyanogenesis is controlled by two, independently segregating Mendelian genes: Ac/ac controls the presence/absence of cyanogenic glucosides; and Li/li controls the presence/absence of their hydrolysing enzyme, linamarase. In this study, we examine the molecular evolution and population genetics of Li as it relates to the cyanogenesis polymorphism. We report here that Li exists as a single-copy gene in plants possessing linamarase activity, and that the absence of enzyme activity in li/li plants is correlated with the absence of much or all of the gene from the white clover genome. Consistent with this finding, we confirm by reverse transcription-polymerase chain reaction that Li gene expression is absent in plants lacking enzyme activity. In a molecular population genetic analysis of Li and three unlinked genes using a worldwide sample of clover plants, we find an absence of nucleotide variation and statistically significant deviations from neutrality at Li; these findings are consistent with recent positive directional selection at this cyanogenesis locus.


Assuntos
Evolução Molecular , Polimorfismo Genético , Trifolium/genética , beta-Glucosidase/química , Southern Blotting , Dosagem de Genes , Ligação Genética , Cianeto de Hidrogênio/metabolismo , Trifolium/enzimologia , beta-Glucosidase/genética
13.
J Econ Entomol ; 100(3): 894-902, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17598553

RESUMO

Transgenic cotton, Gossypium hirsutum L., expressing the crylAc and cry2Ab genes from Bacillus thuringiensis (Bt) Berliner variety kurstaki in a pyramid (Bollgard II) was widely planted for the first time in Australia during the 2004-2005 growing season. Before the first commercial Bollgard II crops, limited amounts of cotton expressing only the crylAc gene (Ingard) was grown for seven seasons. No field failures due to resistance to CrylAc toxin were observed during that period and a monitoring program indicated that the frequency of genes conferring high level resistance to the CrylAc toxin were rare in the major pest of cotton, Helicoverpa armigera (Htibner) (Lepidoptera: Noctuidae). Before the deployment of Bollgard II, an allele conferring resistance to Cry2Ab toxin was detected in field-collected H. armigera. We established a colony (designated SP15) consisting of homozygous resistant individuals and examined their characteristics through comparison with individuals from a Bt-susceptible laboratory colony (GR). Through specific crosses and bioassays, we established that the resistance present in SP15 was due to a single autosomal gene. The resistance was recessive. Homozygotes were highly resistant to Cry2Ab toxin, so much so, that we were unable to induce significant mortality at the maximum concentration of toxin available. Homozygotes also were unaffected when fed leaves of a cotton variety expressing the cry2Ab gene. Although cross-resistant to Cry2Aa toxin, SP15 was susceptible to CrylAc and to the Bt product DiPel.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Endotoxinas/genética , Gossypium/genética , Proteínas Hemolisinas/genética , Inseticidas , Mariposas/genética , Plantas Geneticamente Modificadas/toxicidade , Alelos , Animais , Austrália , Toxinas de Bacillus thuringiensis , Genes Recessivos , Resistência a Inseticidas/genética
14.
Theor Appl Genet ; 114(5): 901-13, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17219204

RESUMO

Aluminum (Al) toxicity in acid soils is a major limitation to the production of alfalfa (Medicago sativa subsp. sativa L.) in the USA. Developing Al-tolerant alfalfa cultivars is one approach to overcome this constraint. Accessions of wild diploid alfalfa (M. sativa subsp. coerulea) have been found to be a source of useful genes for Al tolerance. Previously, two genomic regions associated with Al tolerance were identified in this diploid species using restriction fragment length polymorphism (RFLP) markers and single marker analysis. This study was conducted to identify additional Al-tolerance quantitative trait loci (QTLs); to identify simple sequence repeat (SSR) markers that flank the previously identified QTLs; to map candidate genes associated with Al tolerance from other plant species; and to test for co-localization with mapped QTLs. A genetic linkage map was constructed using EST-SSR markers in a population of 130 BC(1)F(1) plants derived from the cross between Al-sensitive and Al-tolerant genotypes. Three putative QTLs on linkage groups LG I, LG II and LG III, explaining 38, 16 and 27% of the phenotypic variation, respectively, were identified. Six candidate gene markers designed from Medicago truncatula ESTs that showed homology to known Al-tolerance genes identified in other plant species were placed on the QTL map. A marker designed from a candidate gene involved in malic acid release mapped near a marginally significant QTL (LOD 2.83) on LG I. The SSR markers flanking these QTLs will be useful for transferring them to cultivated alfalfa via marker-assisted selection and for pyramiding Al tolerance QTLs.


Assuntos
Alumínio/toxicidade , Medicago sativa/efeitos dos fármacos , Medicago sativa/genética , Mapeamento Cromossômico , Diploide , Etiquetas de Sequências Expressas , Genes de Plantas , Repetições Minissatélites , Fenótipo , Polimorfismo Genético , Locos de Características Quantitativas
15.
J Econ Entomol ; 100(6): 1844-53, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18232402

RESUMO

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important lepidopteran pest of cotton (Gossypium spp.) in Australia and the Old World. From 2002, F2 screens were used to examine the frequency of resistance alleles in Australian populations of H. armigera to Bacillus thuringiensis (Bt) CrylAc and Cry2Ab, the two insecticidal proteins present in the transgenic cotton Bollgard II. At that time, Ingard (expressing Cry1Ac) cotton had been grown in Australia for seven seasons, and Bollgard II was about to be commercially released. The principal objective of our study was to determine whether sustained exposure caused an elevated frequency of alleles conferring resistance to Cry1Ac in a species with a track record of evolving resistance to conventional insecticides. No major alleles conferring resistance to Cry1Ac were found. The frequency of resistance alleles for Cry1Ac was <0.0003, with a 95% credibility interval between 0 and 0.0009. In contrast, alleles conferring resistance to Cry2Ab were found at a frequency of 0.0033 (0.0017, 0.0055). The first isolation of this allele was found before the widespread deployment of Bollgard II. For both toxins the experiment-wise detection probability was 94.4%. Our results suggest that alleles conferring resistance to Cry1Ac are rare and that a relatively high baseline frequency of alleles conferring resistance to Cry2Ab existed before the introduction of Bt cotton containing this toxin.


Assuntos
Proteínas de Bactérias/farmacologia , Toxinas Bacterianas/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Resistência a Inseticidas/genética , Mariposas/efeitos dos fármacos , Mariposas/genética , Alelos , Animais , Austrália , Toxinas de Bacillus thuringiensis , Demografia
16.
Aliment Pharmacol Ther ; 24(11-12): 1603-11, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17206948

RESUMO

BACKGROUND: It is unclear how delivery through a feeding tube compares between esomeprazole in water, lansoprazole oral disintegrating tablet in water, omeprazole/NaHCO(3) in water and simplified lansoprazole suspension. AIM: This in vitro study compared delivery through a narrow calibre (8F) feeding tube among four proton pump inhibitors when given by skilled [nurse; (n = 8)] or unskilled [lay; (n = 8)] providers. METHODS: Following standard instruction, subjects were observed delivering each proton pump inhibitor in a sequential, but random, fashion to evaluate administration quality and time. Delivery was quantified using high-performance liquid chromatography methods and subject preferences were evaluated. RESULTS: Delivery (%), similar between lansoprazole oral disintegrating tablet (95.7 +/- 3.2) and omeprazole/NaHCO(3) (96.1 +/- 3.0), was both greater for lansoprazole oral disintegrating tablet than esomeprazole in water (88.9 +/- 8.6; P = 0.006) or simplified lansoprazole suspension (86.1 +/- 9.5; P = 0.0001) and omeprazole/NaHCO(3) than esomeprazole in water (P = 0.004) or simplified lansoprazole suspension (P < 0.001), and was not affected by prior subject experience. Quality was higher with both omeprazole/NaHCO(3) and lansoprazole oral disintegrating tablet than simplified lansoprazole suspension. Administration was quicker for lansoprazole oral disintegrating tablet than esomeprazole in water. Subjects preferred lansoprazole oral disintegrating tablet and omeprazole/NaHCO(3). CONCLUSIONS: When given through an in vitro feeding tube, omeprazole/NaHCO(3) and lansoprazole oral disintegrating tablet lead to greater drug delivery, improved administration quality and higher user satisfaction, than either esomeprazole in water or simplified lansoprazole suspension.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/administração & dosagem , Antiulcerosos/administração & dosagem , Omeprazol/administração & dosagem , Inibidores da Bomba de Prótons , Administração Oral , Adulto , Esomeprazol , Feminino , Humanos , Infusões Parenterais , Lansoprazol , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Bombas de Próton/administração & dosagem
17.
J Econ Entomol ; 98(4): 1382-90, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16156594

RESUMO

The efficacy of Cry1Ac Bacillus thuringiensis (Bt) cotton plants against field populations of Helicoverpa armigera (Hübner) has been inconsistent over the growing season. Any reduction in efficacy (where efficacy is the capacity of the plant to affect the survival of the insect) increases the opportunities for H. armigera to evolve resistance to Bt toxin. Changes in efficacy could be due to changes at the level of gene expression and/or in the physiological makeup of the plant and may be induced by environmental conditions. Two environmental factors, temperature and insect damage, were investigated. Temperature was found to affect efficacy, whether plants were grown at different temperatures continuously or were exposed to a change in temperature for a short period. Damage caused by chewing insects (H. armigera larvae) produced a dramatic increase in the efficacy of presquare Bt cotton. In contrast, damage by sucking insects (aphids) did not induce changes in efficacy. Changes in efficacy seemed to be mediated through modification of the physiological background of the plant rather than changes in the level of Cry1Ac expression or in the concentration of the Bt toxin. The impact of the non-Bt responses of plants on strains of H. armigera should be evaluated. It is possible that by enhancing existing defensive mechanisms of plants, the rate of evolution of resistance to Bt toxins could be retarded by increasing the plants overall toxicity through the additive effects of the toxins and plant defenses.


Assuntos
Afídeos/fisiologia , Proteínas de Bactérias/biossíntese , Toxinas Bacterianas/biossíntese , Endotoxinas/biossíntese , Gossypium/fisiologia , Mariposas/fisiologia , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Endotoxinas/genética , Gossypium/parasitologia , Proteínas Hemolisinas , Larva , Plantas Geneticamente Modificadas , Temperatura
18.
J Econ Entomol ; 98(3): 1007-17, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16022333

RESUMO

The insertion of genes encoding insecticidal Cry1A delta-endotoxins from the bacterium Bacillus thuringiensis Berliner variety kurstaki (Bt) into varieties of cotton (Gossypium spp.) was undertaken to assist in the control of a range of lepidopteran pests. In Australia, where Helicoverpa armigera (Hübner) and Helicoverpa punctigera (Wallengren) are major pests, the level of control is useful, but not complete, because efficacy declines as the crop matures. Fluctuations in the efficacy of Bt cotton, to the extent that some insects survive, provide opportunities for H. armigera to develop resistance to the Bt toxin. Therefore, variations in the efficacy of Bt cotton need to be understood if we are to plan rational resistance management strategies to retard the rate of the development of resistance. We measured the changes in efficacy associated with plant development over the growing season, in the field and glasshouse. In addition, the levels of Cry1Ac protein toxin and cry1Ac RNA were determined. In this first demonstration of the relationship between these three factors, we found that the developmental decline in bioefficacy in field-grown plants was associated with reduced cry1Ac transcript levels and Bt toxin levels in postsquaring cotton. In addition, changes in plant chemistry associated with the maturation of the cotton plant were observed to contribute to changes in the efficacy of Bt toxin. Results from the field and glasshouse suggested that variations in efficacy within the growing season and between seasons also may be influenced by environmental factors.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Endotoxinas/genética , Gossypium/genética , Inseticidas , Lepidópteros , Plantas Geneticamente Modificadas , Estações do Ano , Animais , Toxinas de Bacillus thuringiensis , Expressão Gênica , Variação Genética , Proteínas Hemolisinas , Controle Biológico de Vetores , RNA Mensageiro/análise
19.
Scand J Clin Lab Invest ; 61(3): 237-46, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11386610

RESUMO

Urinary excretion profiles of diazepam metabolites were investigated. The subjects were healthy volunteers receiving one single 10-mg dose of diazepam or drug abusers starting a prison sentence. Urinary excretion of metabolites was analysed by immunological screening, liquid chromatography and gas chromatography-mass spectrometry. Relating the metabolite concentration to creatinine concentration in the specimens decreased sample-to-sample variations. In some cases such correction could protect a subject from erroneous accusations of a new intake.


Assuntos
Ansiolíticos/farmacocinética , Diazepam/farmacocinética , Transtornos Relacionados ao Uso de Substâncias/urina , Adulto , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Creatinina/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nordazepam/urina , Oxazepam/urina , Detecção do Abuso de Substâncias , Temazepam/urina
20.
Int J Sports Med ; 22(4): 301-3, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11414675

RESUMO

Few studies have documented the long-term recovery of hand function after open carpal tunnel release surgery. Grip strength and manual dexterity were measured before and every five weeks up to 25 weeks after open carpal tunnel release in a sample of 11 affected wrists. Dexterity scores prior to surgery were substantially (nearly 3sd) below normative levels. There was a significant (t10=5.45, P<0.001) 37% decrease in grip strength immediately following surgery. Trend analysis of the data indicated a significant second order pattern for the decrease and recovery of grip strength, and a significant linear pattern of recovery of dexterity following surgery. The strength and dexterity tests were effective in documenting changes in function in recovery from open carpal tunnel release surgery, but grip strength and dexterity in these subjects only recovered to pre-operative levels at 25 weeks.


Assuntos
Síndrome do Túnel Carpal/reabilitação , Síndrome do Túnel Carpal/cirurgia , Força da Mão/fisiologia , Síndrome do Túnel Carpal/fisiopatologia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
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