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1.
Proc Natl Acad Sci U S A ; 120(51): e2309034120, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38079550

RESUMO

There is an urgent need for reliable data on the impacts of deforestation on tropical biodiversity. The city-state of Singapore has one of the most detailed biodiversity records in the tropics, dating back to the turn of the 19th century. In 1819, Singapore was almost entirely covered in primary forest, but this has since been largely cleared. We compiled more than 200 y of records for 10 major taxonomic groups in Singapore (>50,000 individual records; >3,000 species), and we estimated extinction rates using recently developed and novel statistical models that account for "dark extinctions," i.e., extinctions of undiscovered species. The estimated overall extinction rate was 37% (95% CI [31 to 42%]). Extrapolating our Singapore observations to a future business-as-usual deforestation scenario for Southeast Asia suggests that 18% (95% CI [16 to 22%]) of species will be lost regionally by 2100. Our extinction estimates for Singapore and Southeast Asia are a factor of two lower than previous estimates that also attempted to account for dark extinctions. However, we caution that particular groups such as large mammals, forest-dependent birds, orchids, and butterflies are disproportionately vulnerable.


Assuntos
Borboletas , Animais , Singapura , Conservação dos Recursos Naturais , Extinção Biológica , Biodiversidade , Mamíferos
2.
Proc Natl Acad Sci U S A ; 120(43): e2307340120, 2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-37844245

RESUMO

Echolocation, the detection of objects by means of sound waves, has evolved independently in diverse animals. Echolocators include not only mammals such as toothed whales and yangochiropteran and rhinolophoid bats but also Rousettus fruit bats, as well as two bird lineages, oilbirds and swiftlets. In whales and yangochiropteran and rhinolophoid bats, positive selection and molecular convergence has been documented in key hearing-related genes, such as prestin (SLC26A5), but few studies have examined these loci in other echolocators. Here, we examine patterns of selection and convergence in echolocation-related genes in echolocating birds and Rousettus bats. Fewer of these loci were under selection in Rousettus or birds compared with classically recognized echolocators, and elevated convergence (compared to outgroups) was not evident across this gene set. In certain genes, however, we detected convergent substitutions with potential functional relevance, including convergence between Rousettus and classic echolocators in prestin at a site known to affect hair cell electromotility. We also detected convergence between Yangochiroptera, Rhinolophidea, and oilbirds in TMC1, an important mechanosensory transduction channel in vertebrate hair cells, and observed an amino acid change at the same site within the pore domain. Our results suggest that although most proteins implicated in echolocation in specialized mammals may not have been recruited in birds or Rousettus fruit bats, certain hearing-related loci may have undergone convergent functional changes. Investigating adaptations in diverse echolocators will deepen our understanding of this unusual sensory modality.


Assuntos
Quirópteros , Ecolocação , Animais , Quirópteros/fisiologia , Filogenia , Evolução Molecular , Mamíferos/genética , Audição/genética , Baleias/fisiologia , Aves/genética , Ecolocação/fisiologia
3.
Ecol Evol ; 13(2): e9805, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36818536

RESUMO

Resource partitioning may facilitate the coexistence of sympatric species with similar ecological requirements. Here, we study a colony of unusual echolocating birds called swiftlets, which nest underground on an island off the coast of Singapore. The colony comprises two congeneric swiftlet species, black-nest swiftlets (Aerodramus maximus) and edible-nest swiftlets (A. fuciphagus), nesting at high densities and in close proximity. Bioacoustic recordings and monitoring of nesting biology at the site across multiple seasons revealed significant differences in echolocation calls as well as survival rates between the species, with the larger black-nest swiftlet nesting at locations with the highest fledging rates. We also observe an additional off-season breeding peak by the smaller species, the edible-nest swiftlet. Unexpectedly, off-season egg-hatching rates were significantly higher compared with the rates during the shared breeding season (mean difference = 14%). Our study on the breeding biology of these echolocating cave-dwelling birds provides an example of spatial and temporal strategies that animals employ to partition resources within a confined habitat.

4.
PLoS Genet ; 19(1): e1010551, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36656838

RESUMO

Human activities have precipitated a rise in the levels of introgressive gene flow among animals. The investigation of conspecific populations at different time points may shed light on the magnitude of human-mediated introgression. We used the red junglefowl Gallus gallus, the wild ancestral form of the chicken, as our study system. As wild junglefowl and domestic chickens readily admix, conservationists fear that domestic introgression into junglefowl may compromise their wild genotype. By contrasting the whole genomes of 51 chickens with 63 junglefowl from across their natural range, we found evidence of a loss of the wild genotype across the Anthropocene. When comparing against the genomes of junglefowl from approximately a century ago using rigorous ancient-DNA protocols, we discovered that levels of domestic introgression are not equal among and within modern wild populations, with the percentage of domestic ancestry around 20-50%. We identified a number of domestication markers in which chickens are deeply differentiated from historic junglefowl regardless of breed and/or geographic provenance, with eight genes under selection. The latter are involved in pathways dealing with development, reproduction and vision. The wild genotype is an allelic reservoir that holds most of the genetic diversity of G. gallus, a species which is immensely important to human society. Our study provides fundamental genomic infrastructure to assist in efforts to prevent a further loss of the wild genotype through introgression of domestic alleles.


Assuntos
Galinhas , Genética Populacional , Genoma , Animais , Galinhas/genética , Fluxo Gênico , Genoma/genética , Genótipo , Filogenia
5.
Mol Biol Evol ; 39(2)2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-34978567

RESUMO

Sensory receptor evolution can imply trade-offs between ligands, but the extent to which such trade-offs occur and the underlying processes shaping their evolution is not well understood. For example, hummingbirds have repurposed their ancestral savory receptor (T1R1-T1R3) to detect sugars, but the impact of this sensory shift on amino acid perception is unclear. Here, we use functional and behavioral approaches to show that the hummingbird T1R1-T1R3 acts as a bifunctional receptor responsive to both sugars and amino acids. Our comparative analyses reveal substantial functional diversity across the hummingbird radiation and suggest an evolutionary timeline for T1R1-T1R3 retuning. Finally, we identify a novel form of synergism between sugars and amino acids in vertebrate taste receptors. This work uncovers an unexplored axis of sensory diversity, suggesting new ways in which nectar chemistry and pollinator preferences can coevolve.


Assuntos
Papilas Gustativas , Paladar , Animais , Aves/metabolismo , Ligantes , Receptores Acoplados a Proteínas G , Papilas Gustativas/metabolismo
6.
Evol Appl ; 14(3): 698-709, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33767745

RESUMO

Urgent conservation action for terminally endangered species is sometimes hampered by taxonomic uncertainty, especially in illegally traded animals that are often cross-bred in captivity. To overcome these problems, we used a genomic approach to analyze historical DNA from museum samples across the Asian Pied Starling (Gracupica contra) complex in tropical Asia, a popular victim of the ongoing songbird crisis whose distinct Javan population ("Javan Pied Starling") is extinct in the wild and subject to admixture in captivity. Comparing genomic profiles across the entire distribution, we detected three deeply diverged lineages at the species level characterized by a lack of genomic intermediacy near areas of contact. Our study demonstrates that the use of historical DNA can be instrumental in delimiting species in situations of taxonomic uncertainty, especially when modern admixture may obfuscate species boundaries. Results of our research will enable conservationists to commence a dedicated ex situ breeding program for the Javan Pied Starling, and serve as a blueprint for similar conservation problems involving terminally endangered species subject to allelic infiltration from close congeners.

7.
Elife ; 92020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33350381

RESUMO

Archipelagoes serve as important 'natural laboratories' which facilitate the study of island radiations and contribute to the understanding of evolutionary processes. The white-eye genus Zosterops is a classical example of a 'great speciator', comprising c. 100 species from across the Old World, most of them insular. We achieved an extensive geographic DNA sampling of Zosterops by using historical specimens and recently collected samples. Using over 700 genome-wide loci in conjunction with coalescent species tree methods and gene flow detection approaches, we untangled the reticulated evolutionary history of Zosterops, which comprises three main clades centered in Indo-Africa, Asia, and Australasia, respectively. Genetic introgression between species permeates the Zosterops phylogeny, regardless of how distantly related species are. Crucially, we identified the Indonesian archipelago, and specifically Borneo, as the major center of diversity and the only area where all three main clades overlap, attesting to the evolutionary importance of this region.


Assuntos
Especiação Genética , Filogenia , Aves Canoras/genética , Animais , Fluxo Gênico/genética , Indonésia
8.
Sci Rep ; 10(1): 15549, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968132

RESUMO

In today's environmental crisis, conservationists are increasingly confronted with terminally endangered species whose last few surviving populations may be affected by allelic introgression from closely related species. Yet there is a worrying lack of evidence-based recommendations and solutions for this emerging problem. We analyzed genome-wide DNA markers and plumage variability in a critically endangered insular songbird, the Black-winged Myna (BWM, Acridotheres melanopterus). This species is highly threatened by the illegal wildlife trade, with its wild population numbering in the low hundreds, and its continued survival urgently depending on ex-situ breeding. Its three subspecies occur along a geographic gradient of melanism and are variably interpreted as three species. However, our integrative approach revealed that melanism poorly reflects the pattern of limited genomic differentiation across BWM subspecies. We also uncovered allelic introgression into the most melanistic subspecies, tertius, from the all-black congeneric Javan Myna (A. javanicus), which is native to the same islands. Based on our results, we recommend the establishment of three separate breeding programs to maintain subspecific traits that may confer local adaptation, but with the option of occasional cross-breeding between insurance populations in order to boost genetic diversity and increase overall viability prospects of each breeding program. Our results underscore the importance of evidence-based integrative approaches when determining appropriate conservation units. Given the rapid increase of terminally endangered organisms in need of ex-situ conservation, this study provides an important blueprint for similar programs dealing with phenotypically variable species.


Assuntos
Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Repetições de Microssatélites/genética , Aves Canoras/genética , Alelos , Animais , Cruzamento , Variação Genética/genética , Haplótipos/genética , Fenótipo
9.
Genome Biol Evol ; 11(8): 2332-2343, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31418795

RESUMO

Müllerian mimicry rings are remarkable symbiotic species assemblages in which multiple members share a similar phenotype. However, their evolutionary origin remains poorly understood. Although gene flow among species has been shown to generate mimetic patterns in some Heliconius butterflies, mimicry is believed to be due to true convergence without gene flow in many other cases. We investigated the evolutionary history of multiple members of a passerine mimicry ring in the poisonous Papuan pitohuis. Previous phylogenetic evidence indicates that the aposematic coloration shared by many, but not all, members of this genus is ancestral and has only been retained by members of the mimicry ring. Using a newly assembled genome and thousands of genomic DNA markers, we demonstrate gene flow from the hooded pitohui (Pitohui dichrous) into the southern variable pitohui (Pitohui uropygialis), consistent with shared patterns of aposematic coloration. The vicinity of putatively introgressed loci is significantly enriched for genes that are important in melanin pigment expression and toxin resistance, suggesting that gene flow may have been instrumental in the sharing of plumage patterns and toxicity. These results indicate that interspecies gene flow may be a more general mechanism in generating mimicry rings than hitherto appreciated.


Assuntos
Animais Peçonhentos/genética , Evolução Biológica , Fluxo Gênico , Genoma , Pigmentação/genética , Proteínas/genética , Aves Canoras/genética , Animais , Fenótipo , Filogenia , Aves Canoras/classificação , Especificidade da Espécie
10.
Sci Rep ; 9(1): 8546, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31189934

RESUMO

Genetic isolation of populations over evolutionary time leads to the formation of independent species. We examined a pair of shorebirds - the Kentish Plover Charadrius alexandrinus and the enigmatic White-faced Plover C. dealbatus - which display strong plumage differentiation, yet show minimal genetic divergence based on previous mitochondrial and microsatellite work. Two scenarios may lead to this situation: (1) they represent clinal or poorly diverged populations with limited genomic differentiation despite substantial plumage variation, or (2) they are diverging taxa at the cusp of speciation, with ongoing limited gene flow obliterating signals of differentiation in traditional genetic markers. We compared the genotypes of 98 plovers (59 Kentish Plovers, 35 White-faced Plovers and 4 genomic hybrids) sampled in eastern Asia and Europe using ddRADSeq to harvest over 8000 genome-wide SNPs. In contrast to previous studies, our analyses revealed two well defined genomic clusters, with limited hybridization and a narrow contact zone. We also uncovered significant differences in bill length and further sex-specific differences in size, which may signal differences in mate choice between Kentish and White-faced Plovers. Our results support the hypothesis that this shorebird duo is on the verge of speciation.


Assuntos
Charadriiformes/genética , Fluxo Gênico , Genoma , Polimorfismo de Nucleotídeo Único , Caracteres Sexuais , Animais , Feminino , Estudo de Associação Genômica Ampla , Masculino
11.
Zootaxa ; 4250(5): 401-433, 2017 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-28609999

RESUMO

White-bellied swiftlets of the Collocalia esculenta complex constitute a radiation of colony-breeding swifts distributed throughout the tropical Indo-Pacific region. Resolution of their taxonomy is challenging due to their morphological uniformity. To analyze the evolutionary history of this complex, we combine new biometric measurements and results from plumage assessment of museum specimens with novel as well as previously published molecular data. Together, this body of information constitutes the largest systematic dataset for white-bellied swiftlets yet compiled, drawn from 809 individuals belonging to 32 taxa for which new molecular, biometric, and/or plumage data are presented. We propose changing the classification of white-bellied swiftlets, for which two species are currently recognized, to elevate eight regional forms to species level, and we also describe two new subspecies. The ten taxa we recommend recognizing at the species level are: Collocalia linchi (Java to Lombok, Sumatran hills), C. dodgei (montane Borneo), C. natalis (Christmas Island), C. affinis (Greater Sundas, including the Thai-Malay Peninsula and Andaman-Nicobar Islands), C. marginata (Philippines), C. isonota (Philippines), C. sumbawae (west Lesser Sundas), C. neglecta (east Lesser Sundas), C. esculenta (Sulawesi, Moluccas, New Guinea, Bismarck Archipelago, Solomon Islands), and C. uropygialis (Vanuatu, New Caledonia). Future molecular and morphological work is needed to resolve questions of speciation and population affinities in the Philippines, Christmas Island, Wallacea and central Melanesia, and to shed light on historic diversification and patterns of gene flow in the complex.


Assuntos
Aves , Filogenia , Animais , Austrália , Evolução Biológica , Bornéu , DNA Mitocondrial , Fluxo Gênico , Indonésia , Malásia , Melanesia , Nova Caledônia , Nova Guiné , Filipinas , Vanuatu
12.
Conserv Biol ; 30(3): 610-7, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27153528

RESUMO

How many species have gone extinct in modern times before being described by science? To answer this question, and thereby get a full assessment of humanity's impact on biodiversity, statistical methods that quantify undetected extinctions are required. Such methods have been developed recently, but they are limited by their reliance on parametric assumptions; specifically, they assume the pools of extant and undetected species decay exponentially, whereas real detection rates vary temporally with survey effort and real extinction rates vary with the waxing and waning of threatening processes. We devised a new, nonparametric method for estimating undetected extinctions. As inputs, the method requires only the first and last date at which each species in an ensemble was recorded. As outputs, the method provides estimates of the proportion of species that have gone extinct, detected, or undetected and, in the special case where the number of undetected extant species in the present day is assumed close to zero, of the absolute number of undetected extinct species. The main assumption of the method is that the per-species extinction rate is independent of whether a species has been detected or not. We applied the method to the resident native bird fauna of Singapore. Of 195 recorded species, 58 (29.7%) have gone extinct in the last 200 years. Our method projected that an additional 9.6 species (95% CI 3.4, 19.8) have gone extinct without first being recorded, implying a true extinction rate of 33.0% (95% CI 31.0%, 36.2%). We provide R code for implementing our method. Because our method does not depend on strong assumptions, we expect it to be broadly useful for quantifying undetected extinctions.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Extinção Biológica , Animais , Aves , Singapura
13.
Nat Commun ; 7: 11396, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27097561

RESUMO

Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83-99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25-22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20-17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity.


Assuntos
Doenças das Aves/história , Brugia/genética , Filariose Linfática/história , Filariose/história , Transferência Genética Horizontal , Loa/genética , Loíase/história , Wuchereria/genética , Animais , Evolução Biológica , Doenças das Aves/epidemiologia , Doenças das Aves/parasitologia , Doenças das Aves/transmissão , Aves/classificação , Aves/parasitologia , Brugia/classificação , Filariose Linfática/epidemiologia , Filariose Linfática/parasitologia , Filariose Linfática/transmissão , Filariose/epidemiologia , Filariose/parasitologia , Filariose/transmissão , História Antiga , Humanos , Loa/classificação , Loíase/epidemiologia , Loíase/parasitologia , Loíase/transmissão , Filogenia , Filogeografia , Retroelementos , Wuchereria/classificação
14.
Ecol Evol ; 6(1): 78-90, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26811776

RESUMO

With increasing urbanization, urban-fragmented landscapes are becoming more and more prevalent worldwide. Such fragmentation may lead to small, isolated populations that face great threats from genetic factors that affect even avian species with high dispersal propensities. Yet few studies have investigated the population genetics of species living within urban-fragmented landscapes in the Old World tropics, in spite of the high levels of deforestation and fragmentation within this region. We investigated the evolutionary history and population genetics of the olive-winged bulbul (Pycnonotus plumosus) in Singapore, a highly urbanized island which retains <5% of its original forest cover in fragments. Combining our own collected and sequenced samples with those from the literature, we conducted phylogenetic and population genetic analyses. We revealed high genetic diversity, evidence for population expansion, and potential presence of pronounced gene flow across the population in Singapore. This suggests increased chances of long-term persistence for the olive-winged bulbul and the ecosystem services it provides within this landscape.

15.
J Clin Pediatr Dent ; 36(3): 245-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22838225

RESUMO

PURPOSE: Local anesthesia by mandibular block or maxillary infiltration is commonly administered to children receiving dental treatment of primary molars. Discomfort, when presenting, most often involves the lower lip. The purpose of this study was to investigate whether children would be more opposed to attending a dental treatment following anesthesia by mandibular block than by maxillary infiltration. METHODS: Each of 102 children in two age groups: 3 to 5 years, and 6 to 9 years, received the two types of local anesthesia at dental appointments one week apart. Their opposition to attending a subsequent appointment was assessed by parent report. RESULTS: More adverse reactions were observed during and following anesthesia with mandibular block than with maxillary infiltration. Few of the children in either age group expressed opposition to attend a dental visit after receiving mandibular block or maxillary infiltration in the previous visit. CONCLUSIONS: Though more adverse reactions were observed in children following mandibular block than maxillary infiltration, this did not result in increased opposition to attend a subsequent dental appointment.


Assuntos
Anestesia Dentária , Comportamento Infantil , Assistência Odontológica para Crianças/psicologia , Nervo Mandibular , Nervo Maxilar , Bloqueio Nervoso/métodos , Analgésicos/uso terapêutico , Anestésicos Locais/administração & dosagem , Atitude Frente a Saúde , Criança , Pré-Escolar , Comportamento Cooperativo , Coroas/psicologia , Choro/psicologia , Restauração Dentária Permanente/psicologia , Feminino , Humanos , Injeções , Lidocaína/administração & dosagem , Masculino , Dente Molar/patologia , Medição da Dor , Estudos Prospectivos , Pulpotomia/psicologia , Extração Dentária/psicologia , Dente Decíduo/patologia
16.
Pharmacoepidemiol Drug Saf ; 21 Suppl 2: 37-43, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22552978

RESUMO

PURPOSE: The National Cancer Institute-funded cooperative oncology group trials have improved overall survival for children with cancer from 10% to 85% and have set standards of care for adults with malignancies. Despite these successes, cooperative oncology groups currently face substantial challenges. We are working to develop methods to improve the efficiency and effectiveness of these trials. Specifically, we merged data from the Children's Oncology Group (COG) and the Pediatric Health Information Systems (PHIS) to improve toxicity monitoring, to estimate treatment-associated resource utilization and costs, and to address important clinical epidemiology questions. METHODS: COG and PHIS data on patients enrolled on a phase III COG trial for de novo acute myeloid leukemia at 43 PHIS hospitals were merged using a probabilistic algorithm. Resource utilization summary statistics were then tabulated for the first chemotherapy course based on PHIS data. RESULTS: Of 416 patients enrolled on the phase III COG trial at PHIS centers, 392 (94%) were successfully matched. Of these, 378 (96%) had inpatient PHIS data available beginning at the date of study enrollment. For these, daily blood product usage and anti-infective exposures were tabulated and standardized costs were described. CONCLUSIONS: These data demonstrate that patients enrolled in a cooperative group oncology trial can be successfully identified in an administrative data set and that supportive care resource utilization can be described. Further work is required to optimize the merging algorithm, map resource utilization metrics to the National Cancer Institute Common Toxicity Criteria for monitoring toxicity, to perform comparative effectiveness studies, and to estimate the costs associated with protocol therapy.


Assuntos
Serviços de Saúde da Criança , Ensaios Clínicos Fase III como Assunto , Pesquisa Comparativa da Efetividade , Oncologia/tendências , Registro Médico Coordenado , Sistemas Computadorizados de Registros Médicos/tendências , Neoplasias , Adolescente , Criança , Serviços de Saúde da Criança/economia , Serviços de Saúde da Criança/normas , Serviços de Saúde da Criança/estatística & dados numéricos , Pré-Escolar , Ensaios Clínicos Fase III como Assunto/economia , Ensaios Clínicos Fase III como Assunto/normas , Ensaios Clínicos Fase III como Assunto/estatística & dados numéricos , Comportamento Cooperativo , Custos e Análise de Custo , Feminino , Hospitais Pediátricos , Humanos , Lactente , Masculino , Oncologia/economia , Oncologia/organização & administração , Oncologia/normas , Oncologia/estatística & dados numéricos , Sistemas Computadorizados de Registros Médicos/economia , Sistemas Computadorizados de Registros Médicos/normas , Sistemas Computadorizados de Registros Médicos/estatística & dados numéricos , National Cancer Institute (U.S.) , Neoplasias/economia , Neoplasias/mortalidade , Neoplasias/terapia , Objetivos Organizacionais , Avaliação de Processos e Resultados em Cuidados de Saúde , Estados Unidos , Adulto Jovem
17.
Neurology ; 77(13): 1253-62, 2011 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-21917766

RESUMO

OBJECTIVE: This randomized, double-blind, placebo-controlled, dose-ranging phase 2 study explored safety, efficacy, and biomarker effects of ELND005 (an oral amyloid anti-aggregation agent) in mild to moderate Alzheimer disease (AD). METHODS: A total of 353 patients were randomized to ELND005 (250, 1,000, or 2,000 mg) or placebo twice daily for 78 weeks. Coprimary endpoints were the Neuropsychological Test Battery (NTB) and Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale. The primary analysis compared 250 mg (n =84) to placebo (n =82) after an imbalance of infections and deaths led to early discontinuation of the 2 higher dose groups. RESULTS: The 250 mg dose demonstrated acceptable safety. The primary efficacy analysis at 78 weeks revealed no significant differences between the treatment groups on the NTB or ADCS-ADL. Brain ventricular volume showed a small but significant increase in the overall 250 mg group (p =0.049). At the 250 mg dose, scyllo-inositol concentrations increased in CSF and brain and CSF Aßx-42 was decreased significantly compared to placebo (p =0.009). CONCLUSIONS: Primary clinical efficacy outcomes were not significant. The safety and CSF biomarker results will guide selection of the optimal dose for future studies, which will target earlier stages of AD. CLASSIFICATION OF EVIDENCE: Due to the small sample sizes, this Class II trial provides insufficient evidence to support or refute a benefit of ELND005.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inositol/administração & dosagem , Inibidores da Agregação Plaquetária/administração & dosagem , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Apolipoproteína E4/genética , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Inositol/sangue , Inositol/farmacocinética , Imageamento por Ressonância Magnética , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Fragmentos de Peptídeos/líquido cefalorraquidiano , Inibidores da Agregação Plaquetária/sangue , Inibidores da Agregação Plaquetária/farmacocinética , Fatores de Tempo , Resultado do Tratamento
18.
Arch Dis Child Fetal Neonatal Ed ; 94(5): F317-22, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19307221

RESUMO

OBJECTIVE: To determine the accuracy of predischarge visual assessment of jaundice for estimating bilirubin concentration and predicting risk of significant neonatal hyperbilirubinaemia. DESIGN: Prospective cohort study. SETTING: Well Baby Nursery at the Hospital of the University of Pennsylvania. PATIENTS: 522 term and late preterm newborns. INTERVENTIONS: Nurses used a 5-point scale to grade the maximum cephalocaudal extent of jaundice prior to discharge. MAIN OUTCOME MEASURES: (1) Correlation between jaundice grade and bilirubin concentration. (2) Predictive accuracy of jaundice grade for identifying infants who developed significant hyperbilirubinaemia, defined as a bilirubin level that at any time after birth exceeded or was within 1 mg/dl (17 micromol/l) of the American Academy of Pediatrics-recommended hour-specific phototherapy treatment threshold. RESULTS: Nurses' assessment of jaundice extent was only moderately correlated with bilirubin concentration and was similar in black and non-black infants (Spearman's rho = 0.45 and 0.55, respectively (p = 0.13)). The correlation was particularly weak among infants <38 weeks' gestational age (rho = 0.29) compared with infants > or = 38 weeks' gestation (rho = 0.53, p = 0.05). Jaundice extent had poor overall accuracy for predicting risk of significant hyperbilirubinaemia (c-statistic = 0.65) but complete absence of jaundice had high sensitivity (95%) and excellent negative predictive value (99%) for ruling out the development of significant hyperbilirubinaemia. CONCLUSIONS: Clinicians should not use extent of cephalocaudal jaundice progression to estimate bilirubin levels during the birth hospitalisation, especially in late preterm infants. However, the complete absence of jaundice can be used to predict with very high accuracy which infants will not develop significant hyperbilirubinaemia.


Assuntos
Bilirrubina/sangue , Icterícia Neonatal/diagnóstico , Pigmentação da Pele , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Icterícia Neonatal/sangue , Masculino , Triagem Neonatal/métodos , Berçários Hospitalares , Pennsylvania , Guias de Prática Clínica como Assunto , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Índice de Gravidade de Doença
19.
Cochrane Database Syst Rev ; (2): CD003558, 2006 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-16625584

RESUMO

BACKGROUND: Inhaled corticosteroids (ICS) and sodium cromoglycate (SCG) have become established as effective controller medications for children and adults with asthma, but their relative efficacy is not clear. OBJECTIVES: To compare the relative effectiveness and adverse effects of ICS and SCG among children and adults with chronic asthma. SEARCH STRATEGY: Systematic search of the Cochrane Airways Group's special register of controlled trials (to Feb. 2004), hand searches of the reference lists of included trials and relevant review papers, and written requests for identification of additional trials from pharmaceutical manufacturers. SELECTION CRITERIA: Randomized controlled trials comparing the effect of ICS with SCG in children and adults with chronic asthma. DATA COLLECTION AND ANALYSIS: All studies were assessed independently for eligibility by three review authors. Disagreements were settled by consensus. Trial authors were contacted to supply missing data or to verify methods. Eligible studies were abstracted and fixed- and random-effects models were implemented to pool studies. Separate analyses were conducted for paediatric and adult studies. Subgroup analyses and meta-regression models were fit to explore heterogeneity of lung function outcomes by type of RCT, category of ICS or SCG dosage, asthma severity of participants, and study quality on outcomes. MAIN RESULTS: Of 67 identified studies, 17 trials involving 1279 children and eight trials involving 321 adults with asthma were eligible. Thirteen (76%) of the paediatric studies and six (75%) of the adult studies were judged to be high quality. Among children, ICS were associated with a higher final mean forced expiratory volume in 1 second [FEV1] (weighted mean difference [WMD] 0.07 litres, 95% confidence interval [CI] 0.02 to 0.11) and higher mean final peak expiratory flow rate [PEF] (WMD 17.3 litres/minute, 95% CI 11.3 to 23.3) than SCG. In addition, ICS were associated with fewer exacerbations (WMD -1.18 exacerbations per year, 95% CI -2.15 to - 0.21), lower asthma symptom scores, and less rescue bronchodilator use than SCG. There were no group differences in the proportion of children with adverse effects. Among adults, ICS were similarly associated with a higher mean final FEV1 (WMD 0.21 litres, 95% CI 0.13 to 0.28) and a higher final endpoint PEF (WMD 28.2 litres/minute, 95% CI 18.7 to 37.6) than SCG. ICS were also associated with fewer exacerbations (WMD -3.30 exacerbations per year, 95% CI -5.62 to -0.98), lower asthma symptom scores among cross-over trials but not parallel trials, and less rescue bronchodilator use than SCG. There were no differences in the proportion of adults with adverse effects. In subgroup analyses involving lung function measures, paediatric and adult studies judged to be of high quality had results consistent with the overall results. Lung function measures in children were higher in studies with medium BDP-equivalent steroid dosages than low BDP-equivalent dosages, while adult studies could not be compared by steroid dosage since they all incorporated similar dosages. There were no significant differences in lung function by the asthma severity of participants for adult or child studies. AUTHORS' CONCLUSIONS: ICS were superior to SCG on measures of lung function and asthma control for both adults and children with chronic asthma. There were few studies reporting on quality of life and health care utilization, which limited our ability to adequately evaluate the relative effects of these medications on a broader range of outcomes. Although there were no differences in adverse effects between ICS and SCG, most trials were short and may not have been of sufficient duration to identify long-term effects. Our results support recent consensus statements in the U.S. and elsewhere that favour the use of ICS over SCG for control of persistent asthma.


Assuntos
Corticosteroides/uso terapêutico , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Cromolina Sódica/uso terapêutico , Administração por Inalação , Adolescente , Adulto , Criança , Glucocorticoides/uso terapêutico , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
20.
Arch Dis Child ; 90(4): 415-21, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15781937

RESUMO

AIMS: To compare the predictive performance of clinical risk factor assessment and pre-discharge bilirubin measurement as screening tools for identifying infants at risk of developing significant neonatal hyperbilirubinaemia (post-discharge total serum bilirubin (TSB) >95th centile). METHODS: Retrospective cohort study of term and near term infants born in an urban community teaching hospital in Pennsylvania (1993-97). A clinical risk factor scoring system was developed and its predictive performance compared to a pre-discharge TSB expressed as a risk zone on a bilirubin nomogram. Main outcome measures were prediction model discrimination, range of predicted probabilities, and sensitivity, specificity, positive and negative predictive values, and likelihood ratios for various positivity criteria. RESULTS: The clinical risk factor scoring system developed included birth weight, gestational age <38 weeks, oxytocin use during delivery, vacuum extraction, breast feeding, and combination breast and bottle feeding. The pre-discharge bilirubin risk zone had better discrimination (c = 0.83; 95% CI 0.80 to 0.86) than the clinical risk factor score (c = 0.71; 95% CI 0.66 to 0.76) and predicted risk of significant hyperbilirubinaemia as high as 59% compared with a maximum of 44% for the clinical risk factor score. Neither the risk score nor the pre-discharge TSB risk zone predicted the outcome with > or =0.98 sensitivity without significantly compromising specificity (0.13 and 0.21, respectively). Multi-level clinical risk factor scores and TSB risk zones produced likelihood ratios of 0.15-3.25 and 0.05-9.43, respectively. CONCLUSIONS: The pre-discharge bilirubin expressed as a risk zone on an hour specific bilirubin nomogram is more accurate and generates wider risk stratification than a clinical risk factor score.


Assuntos
Hiperbilirrubinemia/diagnóstico , Triagem Neonatal/métodos , Medição de Risco/métodos , Estudos de Coortes , Feminino , Hospitais Comunitários , Hospitais de Ensino , Hospitais Urbanos , Humanos , Hiperbilirrubinemia/etiologia , Recém-Nascido , Masculino , Pennsylvania , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco , Sensibilidade e Especificidade
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