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1.
Infect Immun ; 92(1): e0024423, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38099660

RESUMEN

Interactions among pathogen genotypes that vary in host specificity may affect overall transmission dynamics in multi-host systems. Borrelia burgdorferi, a bacterium that causes Lyme disease, is typically transmitted among wildlife by Ixodes ticks. Despite the existence of many alleles of B. burgdorferi's sensu stricto outer surface protein C (ospC) gene, most human infections are caused by a small number of ospC alleles ["human infectious alleles" (HIAs)], suggesting variation in host specificity associated with ospC. To characterize the wildlife host association of B. burgdorferi's ospC alleles, we used metagenomics to sequence ospC alleles from 68 infected individuals belonging to eight mammalian species trapped at three sites in suburban New Brunswick, New Jersey (USA). We found that multiple allele ("mixed") infections were common. HIAs were most common in mice (Peromyscus spp.) and only one HIA was detected at a site where mice were rarely captured. ospC allele U was exclusively found in chipmunks (Tamias striatus), and although a significant number of different alleles were observed in chipmunks, including HIAs, allele U never co-occurred with other alleles in mixed infections. Our results suggest that allele U may be excluding other alleles, thereby reducing the capacity of chipmunks to act as reservoirs for HIAs.


Asunto(s)
Borrelia burgdorferi , Borrelia , Coinfección , Ixodes , Enfermedad de Lyme , Animales , Humanos , Borrelia burgdorferi/genética , Borrelia/genética , Alelos , Enfermedad de Lyme/microbiología , Ixodes/genética , Ixodes/microbiología , Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Sciuridae/genética , Especificidad del Huésped
2.
Mol Ecol ; 33(2): e17217, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38014715

RESUMEN

Social insect reproductives and non-reproductives represent ideal models with which to understand the expression and regulation of alternative phenotypes. Most research in this area has focused on the developmental regulation of reproductive phenotypes in obligately social taxa such as honey bees, while relatively few studies have addressed the molecular correlates of reproductive differentiation in species in which the division of reproductive labour is established only in plastic dominance hierarchies. To address this knowledge gap, we generate the first genome for any stenogastrine wasp and analyse brain transcriptomic data for non-reproductives and reproductives of the facultatively social species Liostenogaster flavolineata, a representative of one of the simplest forms of social living. By experimentally manipulating the reproductive 'queues' exhibited by social colonies of this species, we show that reproductive division of labour in this species is associated with transcriptomic signatures that are more subtle and variable than those observed in social taxa in which colony living has become obligate; that variation in gene expression among non-reproductives reflects their investment into foraging effort more than their social rank; and that genes associated with reproductive division of labour overlap to some extent with those underlying division of labour in the separate polistine origin of wasp sociality but only explain a small portion of overall variation in this trait. These results indicate that broad patterns of within-colony transcriptomic differentiation in this species are similar to those in Polistinae but offer little support for the existence of a strongly conserved 'toolkit' for sociality.


Asunto(s)
Avispas , Abejas/genética , Animales , Avispas/genética , Conducta Social , Predominio Social , Perfilación de la Expresión Génica , Transcriptoma/genética , Reproducción/genética
3.
Eur Arch Otorhinolaryngol ; 281(3): 1105-1114, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37864748

RESUMEN

PURPOSE: Our study goal is to review the efficacy of tranexamic acid in reducing blood loss and operative time in nasal surgeries. METHODS: We included randomized clinical trials using oral or intravenous tranexamic acid, excluded non-randomized studies, topic administration, coagulopathy, and using other drugs interfering in the coagulation cascade. Online databases, National Library of Medicine (MEDLINE-PubMED), Latin American and Caribbean Literature on Health Sciences (Lilacs), Cochrane Library, Embase and Google Scholar were used to perform the search. The review was registered in PROSPERO by no CRD42022310977. Two authors, independently, selected the articles meeting the inclusion criteria. They extracted the data and used RevMan 5 software to perform the meta-analysis. RESULTS: Our search resulted in 16 RCTs that were included in the meta-analysis totalizing 1108 patients. Studies were evaluated resulting in a low risk of bias for the five domains. The use of tranexamic acid resulted in significant reduction in duration of surgery (DOS) and intraoperative blood loss (IBL) had significant reduction. The level of evidence according to GRADE System was high in all studies and variables. CONCLUSION: Tranexamic acid has an important role in reducing intraoperative blood loss and duration of surgery. Our study has some limitations due to the low number of RCTs available in the literature.


Asunto(s)
Antifibrinolíticos , Procedimientos Quírurgicos Nasales , Ácido Tranexámico , Humanos , Ácido Tranexámico/uso terapéutico , Pérdida de Sangre Quirúrgica/prevención & control , Antifibrinolíticos/uso terapéutico , Tempo Operativo , Procedimientos Quírurgicos Nasales/efectos adversos
4.
Parasitology ; 150(11): 1063-1069, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37791496

RESUMEN

Piroplasms, which include the agents of cattle fever and human and dog babesiosis, are a diverse group of blood parasites of significant veterinary and medical importance. The invasive Asian longhorned tick, Haemaphysalis longicornis, is a known vector of piroplasms in its native range in East Asia and invasive range in Australasia. In the USA, H. longicornis has been associated with Theileria orientalis Ikeda outbreaks that caused cattle mortality. To survey invasive populations of H. longicornis for a broad range of piroplasms, 667 questing H. longicornis collected in 2021 from 3 sites in New Jersey, USA, were tested with generalist piroplasm primers targeting the 18S small subunit rRNA (395­515 bp, depending on species) and the cytochrome b oxidase loci (1009 bp). Sequences matching Theileria cervi type F (1 adult, 5 nymphs), an unidentified Theileria species (in 1 nymph), an undescribed Babesia sensu stricto ('true' Babesia, 2 adults, 2 nymphs), a Babesia sp. Coco (also a 'true Babesia', 1 adult, 1 nymph), as well as Babesia microti S837 (1 adult, 4 nymphs) were recovered. Babesia microti S837 is closely related to the human pathogen B. microti US-type. Additionally, a 132 bp sequence matching the cytochrome b locus of deer, Odocoileus virginanus, was obtained from 2 partially engorged H. longicornis. The diverse assemblage of piroplasms now associated with H. longicornis in the USA spans 3 clades in the piroplasm phylogeny and raises concerns of transmission amplification of veterinary pathogens as well as spillover of pathogens from wildlife to humans.


Asunto(s)
Apicomplexa , Babesia , Ciervos , Ixodidae , Parásitos , Piroplasmida , Theileria , Garrapatas , Animales , Estados Unidos/epidemiología , Humanos , Perros , Bovinos , Piroplasmida/genética , Ixodidae/genética , Garrapatas/parasitología , Parásitos/genética , Citocromos b , Apicomplexa/genética , Babesia/genética , Theileria/genética , ARN Ribosómico 18S/genética , Ninfa/parasitología
5.
Parasitology ; 150(14): 1277-1285, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37246557

RESUMEN

The relationships between host phylogenetics, functional traits and parasites in wildlife remain poorly understood in the Neotropics, especially in habitats with marked seasonal variation. Here, we examined the effect of seasonality and host functional traits on the prevalence of avian haemosporidians (Plasmodium and Haemoproteus) in the Brazilian Caatinga, a seasonally dry tropical forest. 933 birds were evaluated for haemosporidian infections. We found a high parasitism prevalence (51.2%), which was correlated with phylogenetic relatedness among avian species. Prevalence varied drastically among the 20 well-sampled species, ranging from 0 to 70%. Seasonality was the main factor associated with infections, but how this abiotic condition influenced parasite prevalence varied according to the host-parasite system. Plasmodium prevalence increased during the rainy season and, after excluding the large sample size of Columbiformes (n = 462/933), Plasmodium infection rate was maintained high in the wet season and showed a negative association with host body mass. No association was found between non-Columbiform bird prevalence and seasonality or body mass when evaluating both Plasmodium and Haemoproteus or only Haemoproteus infections. Parasite community was composed of 32 lineages including 7 new lineages. We evidenced that even dry domains can harbour a high prevalence and diversity of vector-borne parasites and pointed out seasonality as a ruling factor.


Asunto(s)
Enfermedades de las Aves , Haemosporida , Parásitos , Plasmodium , Infecciones Protozoarias en Animales , Animales , Filogenia , Prevalencia , Brasil/epidemiología , Plasmodium/genética , Aves/parasitología , Haemosporida/genética , Bosques , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/parasitología , Infecciones Protozoarias en Animales/epidemiología , Infecciones Protozoarias en Animales/parasitología
6.
Parasitology ; 150(14): 1296-1306, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37655743

RESUMEN

The distribution of avian haemosporidians of the genus Leucocytozoon in the Neotropics remains poorly understood. Recent studies confirmed their presence in the region using molecular techniques alone, but evidence for gametocytes and data on putative competent hosts for Leucocytozoon are still lacking outside highland areas. We combined morphological and molecular data to characterize a new Leucocytozoon species infecting a non-migratory red-legged seriema (Cariama cristata), the first report of a competent host for Leucocytozoon in Brazil. Leucocytozoon cariamae n. sp. is distinguished from the Leucocytozoon fringillinarum group by its microgametocytes that are not strongly appressed to the host cell nucleus. The bird studied was coinfected with Haemoproteus pulcher, and we present a Bayesian phylogenetic analysis based on nearly complete mitochondrial genomes of these 2 parasites. Leucocytozoon cariamae n. sp. morphology is consistent with our phylogenetic analysis indicating that it does not share a recent common ancestor with the L. fringillinarum group. Haemoproteus pulcher and Haemoproteus catharti form a monophyletic group with Haemocystidium parasites of Reptilia, supporting the polyphyly of the genus Haemoproteus. We also discussed the hypothesis that H. pulcher and H. catharti may be avian Haemocystidium, highlighting the need to study non-passerine parasites to untangle the systematics of Haemosporida.


Asunto(s)
Enfermedades de las Aves , Coinfección , Genoma Mitocondrial , Haemosporida , Parásitos , Infecciones Protozoarias en Animales , Animales , Filogenia , Brasil/epidemiología , Teorema de Bayes , Infecciones Protozoarias en Animales/parasitología , Enfermedades de las Aves/parasitología , Haemosporida/genética , Parásitos/genética , Aves
7.
Nature ; 606(7915): 646-649, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35732768
8.
Malar J ; 21(1): 249, 2022 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-36038897

RESUMEN

BACKGROUND: Plasmodium parasites that cause bird malaria occur in all continents except Antarctica and are primarily transmitted by mosquitoes in the genus Culex. Culex quinquefasciatus, the mosquito vector of avian malaria in Hawai'i, became established in the islands in the 1820s. While the deadly effects of malaria on endemic bird species have been documented for many decades, vector-parasite interactions in avian malaria systems are relatively understudied. METHODS: To evaluate the gene expression response of mosquitoes exposed to a Plasmodium infection intensity known to occur naturally in Hawai'i, offspring of wild-collected Hawaiian Cx. quinquefasciatus were fed on a domestic canary infected with a fresh isolate of Plasmodium relictum GRW4 from a wild-caught Hawaiian honeycreeper. Control mosquitoes were fed on an uninfected canary. Transcriptomes of five infected and three uninfected individual mosquitoes were sequenced at each of three stages of the parasite life cycle: 24 h post feeding (hpf) during ookinete invasion; 5 days post feeding (dpf) when oocysts are developing; 10 dpf when sporozoites are released and invade the salivary glands. RESULTS: Differential gene expression analyses showed that during ookinete invasion (24 hpf), genes related to oxidoreductase activity and galactose catabolism had lower expression levels in infected mosquitoes compared to controls. Oocyst development (5 dpf) was associated with reduced expression of a gene with a predicted innate immune function. At 10 dpf, infected mosquitoes had reduced expression levels of a serine protease inhibitor, and further studies should assess its role as a Plasmodium agonist in C. quinquefasciatus. Overall, the differential gene expression response of Hawaiian Culex exposed to a Plasmodium infection intensity known to occur naturally in Hawai'i was low, but more pronounced during ookinete invasion. CONCLUSIONS: This is the first analysis of the transcriptional responses of vectors to malaria parasites in non-mammalian systems. Interestingly, few similarities were found between the response of Culex infected with a bird Plasmodium and those reported in Anopheles infected with human Plasmodium. The relatively small transcriptional changes observed in mosquito genes related to immune response and nutrient metabolism support conclusions of low fitness costs often documented in experimental challenges of Culex with avian Plasmodium.


Asunto(s)
Culex , Culicidae , Malaria Aviar , Malaria , Parásitos , Passeriformes , Plasmodium , Animales , Canarios , Culex/genética , Culex/parasitología , Hawaii , Humanos , Malaria Aviar/parasitología , Oocistos , Passeriformes/parasitología
9.
Parasitology ; 149(13): 1667-1678, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36200511

RESUMEN

Transmission mode is a key factor that influences host­parasite coevolution. Vector-borne pathogens are among the most important disease agents for humans and wildlife due to their broad distribution, high diversity, prevalence and lethality. They comprise some of the most important and widespread human pathogens, such as yellow fever, leishmania and malaria. Vector-borne parasites (in this review, those transmitted by blood-feeding Diptera) follow unique transmission routes towards their vertebrate hosts. Consequently, each part of this tri-partite (i.e. parasite, vector and host) interaction can influence co- and counter-evolutionary pressures among antagonists. This mode of transmission may favour the evolution of greater virulence to the vertebrate host; however, pathogen­vector interactions can also have a broad spectrum of fitness costs to the insect vector. To complete their life cycle, vector-borne pathogens must overcome immune responses from 2 unrelated organisms, since they can activate responses in both vertebrate and invertebrate hosts, possibly creating a trade-off between investments against both types of immunity. Here, we assess how dipteran vector-borne transmission shapes the evolution of hosts, vectors and the pathogens themselves. Hosts, vectors and pathogens co-evolve together in a constant antagonistic arms race with each participant's primary goal being to maximize its performance and fitness.


Asunto(s)
Leishmania , Malaria , Animales , Humanos , Insectos Vectores/parasitología , Estadios del Ciclo de Vida , Virulencia
10.
Parasitology ; 148(12): 1467-1474, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34099070

RESUMEN

Delimiting and describing Plasmodium species in reptiles remains a pressing problem in Haemosporida taxonomy. The few morphological characters used can overlap, and the significance of some life-history traits is not fully understood. Morphologically identical lizard Plasmodium forms have been reported infecting different cell types (red and white blood cells) in the same host and have been considered the same species. An example is Plasmodium tropiduri tropiduri, a species known to infect erythrocytes, thrombocytes and lymphocyte-like cells. Here, both forms of P. t. tropiduri were analysed using light microscope-based morphological characteristics and phylogenetic inferences based on almost complete mitochondrial genomes of parasites naturally infecting lizards in southeastern Brazil. Although morphologically similar, two distinct phylogenetic lineages infecting erythrocytes and non-erythrocytic cells were found. The lineage found in the erythrocytes forms a monophyletic group with species from Colombia. However, the non-erythrocytic lineage shares a recent common ancestor with Plasmodium leucocytica, which infects leucocytes in lizards from the Caribbean islands. Here, Plasmodium ouropretensis n. sp. is described as a species that infects thrombocytes and lymphocyte-like cells.


Asunto(s)
Lagartos , Malaria , Parásitos , Plasmodium , Animales , Eritrocitos/parasitología , Lagartos/parasitología , Malaria/parasitología , Filogenia , Plasmodium/genética
11.
World Dev ; 146: 105561, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36569407

RESUMEN

We evaluate the global welfare consequences of increases in mortality and poverty generated by the Covid-19 pandemic. Increases in mortality are measured in terms of the number of years of life lost (LY) to the pandemic. Additional years spent in poverty (PY) are conservatively estimated using growth estimates for 2020 and two different scenarios for its distributional characteristics. Using years of life as a welfare metric yields a single parameter that captures the underlying trade-off between lives and livelihoods: how many PYs have the same welfare cost as one LY. Taking an agnostic view of this parameter, we compare estimates of LYs and PYs across countries for different scenarios. Three main findings arise. First, we estimate that, as of early June 2020, the pandemic (and the observed private and policy responses) had generated at least 68 million additional poverty years and 4.3 million years of life lost across 150 countries. The ratio of PYs to LYs is very large in most countries, suggesting that the poverty consequences of the crisis are of paramount importance. Second, this ratio declines systematically with GDP per capita: poverty accounts for a much greater share of the welfare costs in poorer countries. Finally, a comparison of these baseline results with mortality estimates in a counterfactual "herd immunity" scenario suggests that welfare losses would be greater in the latter in most countries.

12.
Parasitol Res ; 119(8): 2631-2640, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32556500

RESUMEN

The genus Plasmodium (Plasmodiidae) ranks among the most widespread intracellular protozoan parasites affecting a wide range of mammals, birds, and reptiles. Little information is available about lizard malaria parasites in South America, and the pathological features of the resulting parasitoses remain unknown or poorly understood. To partially fill in these gaps, we conducted blood smear analysis, molecular detection, and phylogenetic and pathological investigations in lizards inhabiting an Atlantic Forest fragment in Paraiba, Brazil. From 104 striped forest whiptails (Kentropyx calcarata) screened for the presence of haemosporidian parasites, 67 (64.4%) were positive. Four of five Amazon lava lizards (Strobilurus torquatus) we collected from this same area were also positive. A total of 27 forest whiptails were infected with a new genetic lineage of Plasmodium kentropyxi and other Plasmodium lineages were also detected. Histopathological analysis in infected forest whiptails revealed systemic intraerythrocytic Plasmodium stages, mainly gametocytes, in the liver, lung, and heart. Also, the liver of infected lizards had mild to moderate levels of Kupffer cell and melanomacrophage hypertrophy/hyperplasia with sinusoid leukocytosis. Overall, our findings suggest that an endemic Plasmodium species causes histological alterations that are not related to major pathological processes in striped forest whiptails.


Asunto(s)
Lagartos/parasitología , Plasmodium/genética , Plasmodium/patogenicidad , Infecciones Protozoarias en Animales/parasitología , Animales , Brasil , Eritrocitos/parasitología , Bosques , Hígado/parasitología , Hígado/patología , Filogenia , Plasmodium/clasificación , Infecciones Protozoarias en Animales/patología
13.
An Acad Bras Cienc ; 92(1): e20180590, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32321017

RESUMEN

This study aimed to analyze the possible effects of diflubenzuron on the associated insect fauna under laboratory, semi-field and field conditions. Laboratory bioassays were performed in aquariums with mortality readings (%) every 24h until 96h, and in semi-fields, insects were kept in basins with readings every 24h for up to 12 days, in triplicates and a control. In the field experiment, a collection was performed before the application of diflubenzuron in ten brick factory pits (25m²) and 15 post-application. The values of LC50 and LC90 for Chironomus were 2.77x10-3g/L and 0.86g/L, respectively, and for Buenoa, they were 0.019g/L and 0.92g/L, a strong relationship was observed between mortality and exposure time (r²>0.8) in all concentrations used. In semi-field, similar mean values of emergency inhibition were observed, except for Euthyplociidae, which was more sensitive. There was no significant difference between the data of richness and diversity of aquatic insects in the field experiment, considering an interval of 15 days (p=0.32). Finally, the data suggest that diflubenzuron may have a negative effect on the associated insect fauna, but in the field experiment the environmental conditions of Anopheles breeding sites may have affected its efficiency.


Asunto(s)
Anopheles/efectos de los fármacos , Diflubenzurón/farmacología , Insecticidas/farmacología , Animales , Larva/efectos de los fármacos , Dosificación Letal Mediana , Control de Mosquitos
14.
Vox Sang ; 114(2): 178-181, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30695814

RESUMEN

Disturbances in the physiological regulation of erythropoietin (EPO) in patients with sickle cell disease (SCD) may contribute to worsening anaemia and increased transfusion requirements, but the use of recombinant EPO in this group of patients is controversial. The objective of this study was to evaluate the use of this drug in adult patients with SCD and its effects on haemoglobin levels and transfusion requirements. We conducted a retrospective analysis at the University of Campinas, with nineteen adults with a diagnosis of SCD (HbSS and HbS/ß+ thalassaemia), who had received at least 1 year of EPO therapy between 2007 and 2014. Haemoglobin concentrations and trends of variation in transfused RBC volumes were compared before and after EPO administration. We observed that seven patients had a good response to treatment (Hb increment higher than 1·5 g/dl) and nine had a partial response (0·5-1·5 g/dl increment) and there was a significant decrease in the need for transfusion amongst those who usually required regular transfusions. There were no increases in the rates of vaso-occlusive crisis or venous thromboembolism in comparison to the year before the onset of the therapy. Erythropoietin therapy led to a marked increase in haemoglobin concentration with a concomitant decrease in the demand for transfusion. Considering all complications related to allogeneic transfusion, we believe that EPO therapy represents an important therapeutic tool in sickle cell anaemia.


Asunto(s)
Anemia de Células Falciformes/tratamiento farmacológico , Eritropoyetina/uso terapéutico , Adulto , Anemia de Células Falciformes/terapia , Transfusión de Eritrocitos/efectos adversos , Eritropoyetina/administración & dosificación , Femenino , Hemoglobinas/análisis , Humanos , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/uso terapéutico
15.
BMC Ophthalmol ; 19(1): 58, 2019 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-30791877

RESUMEN

PURPOSE: Convergence and accommodative insufficiency represent the main cause of complaints during close visual work and can reduce visual performance and comfort. Knowing their prevalence among schoolchildren is fundamental to define strategies for action. The purpose of this study was to estimate the frequency of these conditions in children in 5th and 6th school years in inland Portugal and to assess the impact that each visual condition has on their quality of life, based on the level of visual symptoms. METHODS: a cross-sectional study was carried out with children enrolled in the 5th and 6th school years. 372 children (192 girls) were assessed, with average ages of 10.9 ± 0.9 years. Refractive error and binocular vision assessment, integrating accommodative parameters, were used to analyse the visual condition. Symptoms were quantified using the Portuguese version of the CISS (Convergence Insufficiency Symptom Survey). RESULTS: The prevalence of definite Convergence Insufficiency (CI) in the children assessed was 2%. A prevalence of 6,8% could be considered if clinically significant CI (high suspect and definite categories) cases are accounted. In relation to Accommodative Insufficiency (AI), a frequency rate of 10% was recorded, with 3% of the evaluated children presenting AI and CI simultaneously. The symptoms score was higher in AI than in CI. CONCLUSIONS: A frequency of approximately 10% was found for each one of the visual syndromes, and it was verified that visual discomfort is common among teenagers who carry these conditions. In cases of asthenopia, such as headaches and loss of concentration, associated with near vision activities, there is a requirement to evaluate the quality of binocular vision.


Asunto(s)
Acomodación Ocular , Convergencia Ocular , Trastornos de la Motilidad Ocular/epidemiología , Trastornos de la Visión/epidemiología , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Portugal/epidemiología , Prevalencia , Calidad de Vida , Visión Binocular
16.
BMC Med Inform Decis Mak ; 18(1): 137, 2018 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-30567554

RESUMEN

BACKGROUND: Predicting progression from Mild Cognitive Impairment (MCI) to Alzheimer's Disease (AD) is an utmost open issue in AD-related research. Neuropsychological assessment has proven to be useful in identifying MCI patients who are likely to convert to dementia. However, the large battery of neuropsychological tests (NPTs) performed in clinical practice and the limited number of training examples are challenge to machine learning when learning prognostic models. In this context, it is paramount to pursue approaches that effectively seek for reduced sets of relevant features. Subsets of NPTs from which prognostic models can be learnt should not only be good predictors, but also stable, promoting generalizable and explainable models. METHODS: We propose a feature selection (FS) ensemble combining stability and predictability to choose the most relevant NPTs for prognostic prediction in AD. First, we combine the outcome of multiple (filter and embedded) FS methods. Then, we use a wrapper-based approach optimizing both stability and predictability to compute the number of selected features. We use two large prospective studies (ADNI and the Portuguese Cognitive Complaints Cohort, CCC) to evaluate the approach and assess the predictive value of a large number of NPTs. RESULTS: The best subsets of features include approximately 30 and 20 (from the original 79 and 40) features, for ADNI and CCC data, respectively, yielding stability above 0.89 and 0.95, and AUC above 0.87 and 0.82. Most NPTs learnt using the proposed feature selection ensemble have been identified in the literature as strong predictors of conversion from MCI to AD. CONCLUSIONS: The FS ensemble approach was able to 1) identify subsets of stable and relevant predictors from a consensus of multiple FS methods using baseline NPTs and 2) learn reliable prognostic models of conversion from MCI to AD using these subsets of features. The machine learning models learnt from these features outperformed the models trained without FS and achieved competitive results when compared to commonly used FS algorithms. Furthermore, the selected features are derived from a consensus of methods thus being more robust, while releasing users from choosing the most appropriate FS method to be used in their classification task.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/etiología , Disfunción Cognitiva/complicaciones , Disfunción Cognitiva/psicología , Anciano , Algoritmos , Disfunción Cognitiva/diagnóstico , Progresión de la Enfermedad , Femenino , Humanos , Aprendizaje Automático , Masculino , Pruebas Neuropsicológicas , Pronóstico , Estudios Prospectivos
17.
Molecules ; 23(4)2018 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-29570648

RESUMEN

In the last decade, adsorption has been used to minimize the pollution caused by dyes, which represents a serious environmental problem. In this context, this work reports the preparation of phthalic anhydride-modified cellulose (PhCel), through the reaction of cellulose (Cel) with phthalic anhydride (Ph). The efficiency of the reaction was observed by elemental analysis, Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermogravimetry/derivative thermogravimetry (TG/DTG). The adsorbent matrix (Cel and PhCel) was used in the removal of crystal violet (CV) and methylene blue (MB) dyes in aqueous medium. In the kinetic study, the experimental data obtained had the best fit to the pseudo-first-order model. In general, the isotherms obtained at different temperatures had a best fit to the model proposed by Langmuir, and the CV and MB adsorption process in adsorbent matrixes can be favored strictly by hydrogen bonds and/or electrostatic interactions for Cel and electrostatic interactions for PhCel.


Asunto(s)
Ácidos Carboxílicos/química , Cationes/química , Celulosa/química , Concentración de Iones de Hidrógeno , Cinética , Anhídridos Ftálicos/química , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos X
18.
BMC Bioinformatics ; 18(1): 82, 2017 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-28153040

RESUMEN

BACKGROUND: Biclustering has been largely applied for the unsupervised analysis of biological data, being recognised today as a key technique to discover putative modules in both expression data (subsets of genes correlated in subsets of conditions) and network data (groups of coherently interconnected biological entities). However, given its computational complexity, only recent breakthroughs on pattern-based biclustering enabled efficient searches without the restrictions that state-of-the-art biclustering algorithms place on the structure and homogeneity of biclusters. As a result, pattern-based biclustering provides the unprecedented opportunity to discover non-trivial yet meaningful biological modules with putative functions, whose coherency and tolerance to noise can be tuned and made problem-specific. METHODS: To enable the effective use of pattern-based biclustering by the scientific community, we developed BicPAMS (Biclustering based on PAttern Mining Software), a software that: 1) makes available state-of-the-art pattern-based biclustering algorithms (BicPAM (Henriques and Madeira, Alg Mol Biol 9:27, 2014), BicNET (Henriques and Madeira, Alg Mol Biol 11:23, 2016), BicSPAM (Henriques and Madeira, BMC Bioinforma 15:130, 2014), BiC2PAM (Henriques and Madeira, Alg Mol Biol 11:1-30, 2016), BiP (Henriques and Madeira, IEEE/ACM Trans Comput Biol Bioinforma, 2015), DeBi (Serin and Vingron, AMB 6:1-12, 2011) and BiModule (Okada et al., IPSJ Trans Bioinf 48(SIG5):39-48, 2007)); 2) consistently integrates their dispersed contributions; 3) further explores additional accuracy and efficiency gains; and 4) makes available graphical and application programming interfaces. RESULTS: Results on both synthetic and real data confirm the relevance of BicPAMS for biological data analysis, highlighting its essential role for the discovery of putative modules with non-trivial yet biologically significant functions from expression and network data. CONCLUSIONS: BicPAMS is the first biclustering tool offering the possibility to: 1) parametrically customize the structure, coherency and quality of biclusters; 2) analyze large-scale biological networks; and 3) tackle the restrictive assumptions placed by state-of-the-art biclustering algorithms. These contributions are shown to be key for an adequate, complete and user-assisted unsupervised analysis of biological data. SOFTWARE: BicPAMS and its tutorial available in http://www.bicpams.com .


Asunto(s)
Expresión Génica , Programas Informáticos , Algoritmos , Línea Celular Tumoral , Análisis por Conglomerados , Redes Reguladoras de Genes , Humanos , Mapeo de Interacción de Proteínas
19.
Transfusion ; 57(1): 102-107, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27774609

RESUMEN

BACKGROUND: Low return rates for notification and counseling among donors with reactive serologic screening tests have been reported worldwide. A randomized trial to test the effectiveness of text message, letter, or telephone call reminders to improve return among nonresponding first-time blood donors with reactive serologic tests was conducted. STUDY DESIGN AND METHODS: Donors with serologically reactive screening test results who had a cell phone and resided in the metropolitan telephone area code of São Paulo in the period from August 2013 through July 2014 were eligible. A consecutive sample of first-time donors with reactive screening tests who had not responded to a standard letter requesting the donor return to the blood center were randomly assigned to receive a text, a new letter, or a telephone call requesting return for notification and counseling. Return rates were measured over the subsequent 30 days. RESULTS: The return rate after a phone call reminder was better than that for a text message (39.8% vs. 28.4%; odds ratio [OR], 1.66; 95% confidence interval [CI], 1.05-2.64) but not better than that for a letter (39.8% vs. 34.4%; OR, 1.26; 95% CI, 0.80-1.99). Older age was a predictor of higher rate of return with each year increase in age associated with a 2% increase in the odds of return (OR, 1.02; 95% CI, 1.01-1.04). CONCLUSION: In nonresponding serologic reactive donors, telephone call led to a higher return rate than text message. The results of this study suggest that use of text messages, while attractive for its simplicity, will not lead to increased donor notification success after serologically reactive marker results from blood donation in Brazil.


Asunto(s)
Donantes de Sangre , Sistemas Recordatorios , Envío de Mensajes de Texto , Brasil , Femenino , Humanos , Masculino
20.
Subst Use Misuse ; 51(1): 41-53, 2016 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-26669733

RESUMEN

BACKGROUND: The valley of the rivers Apurímac, Ene, and Mantaro (VRAEM) is the main center of coca production in Peru. This is a jungle area located between southern highland regions, and is notorious for the presence of drug-trafficking and the last remnants of Shining Path guerrillas. As a result, it occupies a central place in security policies in Peru, and has been "demonized" in the national imaginary. OBJECTIVE: This article explores the current situation, recent history, and most important collectives of the VRAEM, challenging stereotypes about it. METHODS: The article is based on short-term fieldwork undertaken in the VRAEM in March 2008, and long-term research conducted in Ayacucho in 2008-2009; and it is contextualized in relation to the literature on coca producing areas and drug policies. RESULTS: The negative image of the VRAEM started in the context of the 1980s-1990s coca boom and Peruvian armed conflict. State policies in the area since then have been mainly based on militarization and repression, contributing to maintain that negative image, which differs of a complex and nuanced local reality. A coca eradication campaign started in 2014, bringing major changes. CONCLUSIONS: The negative image of the VRAEM is largely unfair, and has been mainly based on stereotypes and prejudices. This negative stereotyping contributes to justify and maintain inefficient and pernicious state policies in the area, and to criminalize local people. There is an urgent need for fieldwork-based studies in the area to counteract those negative stereotypes and monitor current events.


Asunto(s)
Control de Medicamentos y Narcóticos , Formulación de Políticas , Estereotipo , Coca , Humanos , Perú
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