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1.
Nature ; 614(7949): 659-663, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36623548

RESUMO

Transmission spectroscopy1-3 of exoplanets has revealed signatures of water vapour, aerosols and alkali metals in a few dozen exoplanet atmospheres4,5. However, these previous inferences with the Hubble and Spitzer Space Telescopes were hindered by the observations' relatively narrow wavelength range and spectral resolving power, which precluded the unambiguous identification of other chemical species-in particular the primary carbon-bearing molecules6,7. Here we report a broad-wavelength 0.5-5.5 µm atmospheric transmission spectrum of WASP-39b8, a 1,200 K, roughly Saturn-mass, Jupiter-radius exoplanet, measured with the JWST NIRSpec's PRISM mode9 as part of the JWST Transiting Exoplanet Community Early Release Science Team Program10-12. We robustly detect several chemical species at high significance, including Na (19σ), H2O (33σ), CO2 (28σ) and CO (7σ). The non-detection of CH4, combined with a strong CO2 feature, favours atmospheric models with a super-solar atmospheric metallicity. An unanticipated absorption feature at 4 µm is best explained by SO2 (2.7σ), which could be a tracer of atmospheric photochemistry. These observations demonstrate JWST's sensitivity to a rich diversity of exoplanet compositions and chemical processes.

2.
Sci Total Environ ; 858(Pt 2): 159161, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36191696

RESUMO

The presence of SARS-CoV-2 in untreated sewage has been confirmed in many countries but its incidence and infection risk in contaminated waters is poorly understood. The River Thames in the UK receives untreated sewage from 57 Combined Sewer Overflows (CSOs), with many discharging dozens of times per year. This study investigated if such discharges provide a pathway for environmental transmission of SARS-CoV-2. Samples of wastewater, surface water, and sediment collected close to six CSOs on the River Thames were assayed over eight months for SARS-CoV-2 RNA and infectious virus. Bivalves were also sampled as an indicator species of viral bioaccumulation. Sediment and water samples from the Danube and Sava rivers in Serbia, where raw sewage is also discharged in high volumes, were assayed as a positive control. No evidence of SARS-CoV-2 RNA or infectious virus was found in UK samples, in contrast to RNA positive samples from Serbia. Furthermore, this study shows that infectious SARS-CoV-2 inoculum is stable in Thames water and sediment for <3 days, while SARS-CoV-2 RNA is detectable for at least seven days. This indicates that dilution of wastewater likely limits environmental transmission, and that detection of viral RNA alone is not an indication of pathogen spillover.


Assuntos
COVID-19 , Esgotos , Humanos , Águas Residuárias , SARS-CoV-2 , RNA Viral , Monitoramento Ambiental , COVID-19/epidemiologia , Água
3.
Multimed Tools Appl ; 81(18): 26143-26161, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35368859

RESUMO

Red lesion identification at its early stage is very essential for the treatment of diabetic retinopathy to prevent loss of vision. This work proposes a red lesion detection algorithm that uses Hexagonal pattern-based features with two-level segmentation that can detect hemorrhage and microaneurysms in the fundus image. The proposed scheme initially pre-processes the fundus image followed by a two-level segmentation. The level 1 segmentation eliminates the background whereas the level 2 segmentation eliminates the blood vessels that introduce more false positives. A hexagonal pattern-based feature is extracted from the red lesion candidates which can highly differentiate the lesion from non-lesion regions. The hexagonal pattern features are then trained using the recurrent neural network and are classified to eliminate the false negatives. For the evaluation of the proposed red lesion algorithm, the datasets namely ROC challenge, e-ophtha, DiaretDB1, and Messidor are used with the metrics such as Accuracy, Recall, Precision, F1 score, Specificity, and AUC. The scheme provides an average Accuracy, Recall (Sensitivity), Precision, F1 score, Specificity, and AUC of 95.48%, 84.54%, 97.3%, 90.47%, 86.81% and 93.43% respectively.

4.
Lett Appl Microbiol ; 71(2): 210-217, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32304584

RESUMO

The effects of soil type and temperature on the survival of a cocktail of five Salmonella enterica serotypes (Enteritidis, Infantis, Montevideo, Typhimurium and Zanzibar) in manure-amended soils under controlled laboratory conditions was assessed. Containers of clay loam or sandy soil, unaltered or amended with 2% (w/w) poultry manure, were inoculated with S. enterica (~5 log10 CFU per gram) and held at 5, 21 or 37°C for 6 weeks. Statistical analysis of the persistence of S. enterica identified a significant three-way interaction between soil type, manure amendment and temperature. Clay loam soils and lower temperatures tended to support S. enterica persistence over 6 weeks with only 1- and 2-log reductions respectively. In contrast, sand and higher temperatures resulted in a 4-log and either 3- to 4-log reductions respectively. Manure amendment had an overarching effect of reducing die-off of S. enterica in comparison with unamended soils. This study highlights that a large component of variation of the rate of S. enterica reduction in soils may be attributed to combinations of environmental factors, in particular, soil type and temperature. It further underscores the importance of risk management strategies and industry guidelines based on local data and that reflect the diversity of prevailing horticultural production environments. SIGNIFICANCE AND IMPACT OF THE STUDY: The persistence of Salmonella enterica in soil environments was shown to be significantly influenced by a range of individual and interacting environmental effects, including temperature, soil type and amendment addition. This indicates that current horticultural food safety management systems which employ a uniform prescribed exclusion period between application of manure and time of harvest may be unfit for purpose under certain conditions by either underestimating or overestimating pathogen die-off. These findings support exclusion periods that account for a range of environmental factors including temperature, soil type and growing region that may be more appropriate to manage microbiological risks associated with soil which has been amended with manure.


Assuntos
Esterco/microbiologia , Aves Domésticas/microbiologia , Salmonella enterica/crescimento & desenvolvimento , Salmonella enterica/isolamento & purificação , Animais , Temperatura Alta , Salmonella enterica/classificação , Solo/química , Microbiologia do Solo
6.
Appl Radiat Isot ; 151: 317-330, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31376719

RESUMO

A new radio-HPLC detection system for measuring radioactivity in plasma samples during Positron Emission Tomography [PET] studies was developed. It is based on detecting both the positron and one of the annihilation photons. The system focused on improving the measurement of radioactivity concentrations on an unmetabolized positron emitting a radiopharmaceutical [PER] in the presence of its radioactive metabolites, all containing the same positron emitter. This paper presents a new detection configuration that improves the minimal detectible activity (MDA), simplify the measuring systems and reduces the error caused by the metabolites. The detector is based on a plastic scintillator and a BGO scintillation crystal, that produces different light output spectra for signal and noise events. By summing the positron and the annihilated photon light outputs, different spectra are obtained for the metabolite and for the parent compound tracer and for tracer marked by different positron emitting isotopes. This new detection system can improve quantitative analysis of plasma samples. The spectrum change provides up to a three-fold improvement in sensitivity compared to the currently used detection systems that measure only the annihilation coincidence events. Results showed that for 11C the MDA was improved by approximately 520%. Furthermore, it provides the additional advantage of reliability by providing a method for separating the signal and noise readings from the gross detector readout. Accurate reconstruction algorithm of the signal was achieved over a wide measuring range even when the signal was only 5% of the gross measurement.


Assuntos
Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/sangue , Algoritmos , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Reprodutibilidade dos Testes
7.
Public Health ; 168: 76-82, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30708198

RESUMO

OBJECTIVE: The objective of this study was to examine the association between childhood injury and health outcomes among survivors and their mothers using a national survey in the United States (US). STUDY DESIGN: This was a longitudinal analysis of a nationally representative sample. METHODS: Secondary analysis of the 1997-2013 Medical Expenditure Panel Survey (MEPS) was performed. Children (aged 2-18 years) with or without injuries were followed up for two years. Injuries captured in the study were those associated with at least one hospitalization, emergency department visit, or office-based visit. Outcome measures were child and maternal general and mental health status. Multiple mixed-logistic regressions were used with suboptimal health defined as the response of poor or fair health versus good, very good, or excellent health. RESULTS: Of the 63,422 children analyzed, 3251 (4.9%) were injured, representing 3.6 million US children. Injured children were more likely to be male, white, and older than those without injuries (P < 0.01). About a fifth of injured children suffered head injuries. Injuries were strongly associated with suboptimal general and mental health status in children (adjusted odds ratios [AORs], 1.35 and 1.36, respectively, P < 0.05). Mothers of children with injuries were also more likely to report suboptimal mental health (AOR, 1.30, P < 0.05). CONCLUSION: Injuries among children are associated with lasting adverse effects in general and mental health. To improve health outcomes of pediatric injuries, further follow-up care may be needed to ensure that they return to pre-injury health levels. These results highlight the importance of primary prevention and the long-term impact of injuries on the health of children and their mothers.


Assuntos
Saúde da Criança/estatística & dados numéricos , Saúde Materna/estatística & dados numéricos , Ferimentos e Lesões/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Inquéritos Epidemiológicos , Humanos , Masculino , Estados Unidos/epidemiologia
8.
Br Dent J ; 225(11): 993, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30547918

Assuntos
Braquetes , Adulto , Humanos
9.
Nat Commun ; 9(1): 945, 2018 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-29507321

RESUMO

Marine spatial planning (MSP) seeks to reduce conflicts and environmental impacts, and promote sustainable use of marine ecosystems. Existing MSP approaches have successfully determined how to achieve target levels of ocean area for particular uses while minimizing costs and impacts, but they do not provide a framework that derives analytical solutions in order to co-ordinate siting of multiple uses while balancing the effects of planning on each sector in the system. We develop such a framework for guiding offshore aquaculture (bivalve, finfish, and kelp farming) development in relation to existing sectors and environmental concerns (wild-capture fisheries, viewshed quality, benthic pollution, and disease spread) in California, USA. We identify > 250,000 MSP solutions that generate significant seafood supply and billions of dollars in revenue with minimal impacts (often < 1%) on existing sectors and the environment. We filter solutions to identify candidate locations for high-value, low-impact aquaculture development. Finally, we confirm the expectation of substantial value of our framework over conventional planning focused on maximizing individual objectives.


Assuntos
Aquicultura , Conservação dos Recursos Naturais , Ecossistema , Água do Mar , Geografia
10.
Artigo em Inglês | MEDLINE | ID: mdl-31354384

RESUMO

Cognitive impairments seen in people living with HIV (PLWH) are associated with difficulties in everyday functioning, specifically driving. This study utilized speed of processing cognitive remediation therapy (SOP-CRT) with transcranial direct current stimulation (tDCS) to gauge the feasibility and impact on simulated driving. Thirty PLWH (M age = 54.53, SD = 3.33) were randomly assigned to either: sham tDCS SOP-CRT or active tDCS SOP-CRT. Seven indicators of simulated driving performance and safety were obtained. Repeated measures ANOVAs controlling for driver's license status (valid and current license or expired/no license) revealed a large training effect on average driving speed. Participants who received active tDCS SOP-CRT showed a slower average driving speed (p = 0.020, d = 0.972) than those who received sham tDCS SOP-CRT. Non-significant small-to-medium effects were seen for driving violations, collisions, variability in lane positioning, and lane deviations. Combination tDCS SOP-CRT was found to increase indices of cautionary simulated driving behavior. Findings reveal a potential avenue of intervention and rehabilitation for improving driving safety among vulnerable at-risk populations, such as those aging with chronic disease.

11.
Chem Commun (Camb) ; 53(91): 12298-12301, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29094133

RESUMO

Robust methodology to install amide, carbamate, urea and sulfonamide functionality to the 1,8-naphthalimide scaffold has been developed and exemplified. New benzamidonaphthalimide 6, synthesised using this approach, was found to be sensitive to base whereupon fluorescence emission strongly increases (>10-fold) and red-shifts (>4000 cm-1). The optical properties of deprotonated 6 allow for single molecule fluorescence detection, the first example of such behaviour from this class of fluorophore.

12.
Mol Biosyst ; 13(8): 1432-1437, 2017 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-28685788

RESUMO

Type 1 diabetes is associated with such complications as blindness, kidney failure, and nerve damage. Replacing C-peptide, a hormone normally co-secreted with insulin, has been shown to reduce diabetes-related complications. Interestingly, after nearly 30 years of positive research results, C-peptide is still not being co-administered with insulin to diabetic patients. The following review discusses the potential of C-peptide as an auxilliary replacement therapy and why it's not currently being used as a therapeutic.


Assuntos
Peptídeo C/uso terapêutico , Complicações do Diabetes/terapia , Diabetes Mellitus Tipo 1/terapia , Insulina/uso terapêutico , Animais , Bibliometria , Peptídeo C/deficiência , Peptídeo C/história , Peptídeo C/farmacocinética , Ensaios Clínicos como Assunto , Complicações do Diabetes/história , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Diabetes Mellitus Tipo 1/história , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Modelos Animais de Doenças , História do Século XX , História do Século XXI , Humanos , Insulina/deficiência , Insulina/história , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Ferro/metabolismo , Ligação Proteica , Albumina Sérica/metabolismo , Albumina Sérica/farmacocinética , Zinco/metabolismo
13.
Vet Pathol ; 54(3): 549-562, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28438110

RESUMO

Lassa virus (LASV) infection causes an acute, multisystemic viral hemorrhagic fever that annually infects an estimated 100 000 to 300 000 persons in West Africa. This pathogenesis study evaluated the temporal progression of disease in guinea pigs following aerosol and subcutaneous inoculation of the Josiah strain of LASV as well as the usefulness of Strain 13 guinea pigs as an animal model for Lassa fever. After experimental infection, guinea pigs ( Cavia porcellus; n = 67) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and serum chemistry and hematologic changes. Guinea pigs developed viremia on day 5 to 6 postexposure (PE), with clinical signs appearing by day 7 to 8 PE. Complete blood counts revealed lymphopenia and thrombocytopenia. Gross pathologic findings included skin lesions and congested lungs. Histologic lesions consisted of cortical lymphoid depletion by day 6 to 7 PE with lymphohistiocytic interstitial pneumonia at 7 to 8 days PE. Scattered hepatocellular degeneration and cell death were also noted in the liver and, to a lesser extent, in other tissues including the haired skin, lung, heart, adrenal gland, lymph nodes, thymus, and spleen. The first cell types to demonstrate staining for viral antigen were fibroblastic reticular cells and macrophages/dendritic cells in the lymph nodes on day 5 to 6 PE. This study demonstrates similarities between Lassa viral disease in human infections and experimental guinea pig infection. These shared pathologic characteristics support the utility of guinea pigs as an additional animal model for vaccine and therapeutic development under the Food and Drug Administration's Animal Rule.


Assuntos
Cobaias/virologia , Febre Lassa/veterinária , Vírus Lassa , Glândulas Suprarrenais/patologia , Animais , Modelos Animais de Doenças , Progressão da Doença , Feminino , Rim/patologia , Febre Lassa/patologia , Fígado/patologia , Pulmão/patologia , Linfonodos/patologia , Masculino , Miocárdio/patologia , Pele/patologia , Baço/patologia , Timo/patologia , Viremia/patologia , Viremia/veterinária
14.
J Pediatr Urol ; 13(2): 185-186, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28262540

RESUMO

INTRODUCTION: The use of administrative health data for research has prompted questions about its validity for this purpose. OBJECTIVE/STUDY DESIGN: The purpose of this study was to determine the concordance of Pediatric Health Information System (PHIS) perioperative antibiotic charges with the institution's medication administration data for males <10 years old and who underwent outpatient penile/inguinal procedures from July 2013 to March 2015. RESULTS: There was 93.9% positive and negative agreement between perioperative antibiotic charges versus administration. The sensitivity and specificity were 96.8% and 87.2%, respectively. The positive and negative predictive values were 94.6% and 92.2%, respectively. CONCLUSION: This study indicated strong agreement between PHIS pharmacy charges and medication administration.


Assuntos
Procedimentos Cirúrgicos Ambulatórios/estatística & dados numéricos , Antibacterianos/economia , Salas Cirúrgicas/economia , Pacientes Ambulatoriais , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Antibacterianos/uso terapêutico , Criança , Estudos Transversais , Sistemas de Informação em Saúde , Preços Hospitalares , Humanos , Masculino , Assistência Perioperatória/economia , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Estados Unidos , Procedimentos Cirúrgicos Urológicos Masculinos/economia
15.
Vet Parasitol ; 219: 84-99, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-27351036

RESUMO

This guideline is intended to assist in the planning and execution of studies designed to assess the efficacy of ectoparasiticides for fish. It is the first ectoparasite-specific guideline to deal with studies set in the aquatic environment and therefore provides details for the maintenance of environmental standards for finfish. Information is included on a range of pre-clinical study designs as well as clinical studies in commercial/production sites, set within a regulatory framework. It provides information on the study animals, their welfare, husbandry and environmental requirements during the study. The most commonly pathogenic ectoparasites are presented with relevant points regarding life history, host challenge and numeric evaluation. Preparation and presentation of both topical and oral test treatments is provided, together with guidance on data collection and analysis. The guideline provides a quality standard or efficacy studies on finfish, which will assist researchers and regulatory authorities worldwide and contribute to the wider objective of harmonisation of procedures.


Assuntos
Aquicultura/métodos , Testes de Sensibilidade Parasitária/métodos , Testes de Sensibilidade Parasitária/normas , Projetos de Pesquisa , Animais , Antiparasitários/farmacologia , Antiparasitários/uso terapêutico , Ectoparasitoses/tratamento farmacológico , Ectoparasitoses/veterinária , Doenças dos Peixes/tratamento farmacológico , Peixes , Parasitos/efeitos dos fármacos , Drogas Veterinárias/farmacologia
16.
Curr Med Res Opin ; 32(5): 959-65, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26894413

RESUMO

Background Palbociclib is a recently approved drug for use in combination with letrozole as initial endocrine-based therapy for the treatment of postmenopausal women with advanced estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer. This report assesses the impact of palbociclib in combination with letrozole versus letrozole alone on patient-reported outcomes of pain. Methods Palbociclib was evaluated in an open-label, randomized, phase II study (PALOMA-1/TRIO-18) among postmenopausal women with advanced ER+/HER2- breast cancer who had not received prior systemic treatment for their advanced disease. Patients received continuous oral letrozole 2.5 mg daily alone or the same letrozole dose and schedule plus oral palbociclib 125 mg, given once daily for 3 weeks followed by 1 week off over repeated 28-day cycles. The primary study endpoint was investigator-assessed progression-free survival in the intent-to-treat population, and these results have recently been published (Finn et al., Lancet Oncol 2015;16:25-35). One of the key secondary endpoints was the evaluation of pain, as measured using the Brief Pain Inventory (BPI) patient-reported outcome tool. The BPI was administered at baseline and on day 1 of every cycle thereafter until disease progression and/or treatment discontinuation. Clinical trial registration This study is registered with ClinicalTrials.gov (NCT00721409). Results There were no statistically significant differences in Pain Severity or Pain Interference scores of the BPI between the two treatment groups for the overall population or among those with any bone disease at baseline. A limitation of the study is that results were not adjusted for the concomitant use of opioids or other medications used to control pain. Conclusions The addition of palbociclib to letrozole was associated with increased efficacy without negatively impacting pain severity or pain interference with daily activities.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Dor do Câncer/tratamento farmacológico , Nitrilas/uso terapêutico , Piperazinas/uso terapêutico , Piridinas/uso terapêutico , Triazóis/uso terapêutico , Idoso , Dor do Câncer/diagnóstico , Dor do Câncer/etiologia , Intervalo Livre de Doença , Quimioterapia Combinada , Feminino , Humanos , Letrozol , Pessoa de Meia-Idade , Medição da Dor , Receptor ErbB-2 , Receptores de Estrogênio
17.
Environ Microbiol ; 18(6): 2010-24, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26768496

RESUMO

A recent large-scale assessment of bacterial communities across a range of UK soil types showed that bacterial community structure was strongly determined by soil pH. We analysed a data set of eukaryotic 454 sequencing 18S rDNA from the surveyed samples and showed significant differences in eukaryotic assemblages according to pH class, mostly between low pH and higher pH soils. Soil eukaryote communities (per sample) differed most at the taxonomic rank approximating to order level. Taxonomies assigned with the Protist Ribosomal Reference and the Silva 119 databases were taxonomically inconsistent, mostly due to differing 18S annotations, although general structure and composition according to pH were coherent. A relatively small number of lineages, mostly putative parasitic protists and fungi, drive most differences between pH classes, with weaker contributions from bacterivores and autotrophs. Overall, soil parasites included a large diversity of alveolates, in particular apicomplexans. Phylogenetic analysis of alveolate lineages demonstrates a large diversity of unknown gregarines, novel perkinsids, coccidians, colpodellids and uncharacterized alveolates. Other novel and/or divergent lineages were revealed across the eukaryote tree of life. Our study provides an in-depth taxonomic evaluation of micro-eukaryotic diversity, and reveals novel lineages and insights into their relationships with environmental variables across soil gradients.


Assuntos
Eucariotos/isolamento & purificação , Solo/química , Solo/parasitologia , Animais , Biodiversidade , Eucariotos/classificação , Eucariotos/genética , Fungos/genética , Fungos/isolamento & purificação , Concentração de Íons de Hidrogênio , Parasitos/genética , Parasitos/isolamento & purificação , Filogenia , RNA Ribossômico 18S/genética , Microbiologia do Solo
18.
Vet Pathol ; 53(1): 190-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26139838

RESUMO

Machupo virus, the cause of Bolivian hemorrhagic fever, is a highly lethal viral hemorrhagic fever with no Food and Drug Administration-approved vaccines or therapeutics. This study evaluated the guinea pig as a model using the Machupo virus-Chicava strain administered via aerosol challenge. Guinea pigs (Cavia porcellus) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and sequential changes in serum chemistry and hematology. The incubation period was 5 to 12 days, and complete blood counts revealed leukopenia with lymphopenia and thrombocytopenia. Gross pathologic findings included congestion and hemorrhage of the gastrointestinal mucosa and serosa, noncollapsing lungs with fluid exudation, enlarged lymph nodes, and progressive pallor and friability of the liver. Histologic lesions consisted of foci of degeneration and cell death in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, renal pelvis, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system, interpreted as nonsuppurative encephalitis, was histologically apparent approximately 16 days postexposure and was generally progressive. Macrophages in the tracheobronchial lymph node, on day 5 postexposure, were the first cells to demonstrate visible viral antigen. Viral antigen was detected throughout the lymphoid system by day 9 postexposure, followed by prominent spread within epithelial tissues and then brain. This study provides insight into the course of Machupo virus infection and supports the utility of guinea pigs as an additional animal model for vaccine and therapeutic development.


Assuntos
Arenavirus do Novo Mundo/patogenicidade , Modelos Animais de Doenças , Cobaias , Febre Hemorrágica Americana/patologia , Glândulas Suprarrenais/patologia , Aerossóis , Animais , Epitélio/patologia , Feminino , Febre Hemorrágica Americana/virologia , Humanos , Fígado/patologia , Pulmão/patologia , Linfonodos/patologia , Masculino , Pâncreas/patologia
19.
J Evol Biol ; 29(3): 551-9, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-26663204

RESUMO

A key step in the evolution of multicellular organisms is the formation of cooperative multicellular groups. It has been suggested that predation pressure may promote multicellular group formation in some algae and bacteria, with cells forming groups to lower their chance of being eaten. We use the green alga Chlorella vulgaris and the protist Tetrahymena thermophila to test whether predation pressure can initiate the formation of colonies. We found that: (1) either predators or just predator exoproducts promote colony formation; (2) higher predator densities cause more colonies to form; and (3) colony formation in this system is facultative, with populations returning to being unicellular when the predation pressure is removed. These results provide empirical support for the hypothesis that predation pressure promotes multicellular group formation. The speed of the reversion of populations to unicellularity suggests that this response is due to phenotypic plasticity and not evolutionary change.


Assuntos
Chlorella vulgaris/fisiologia , Tetrahymena thermophila/fisiologia , Animais , Evolução Biológica , Comportamento Predatório
20.
Vet Pathol ; 52(1): 26-37, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24990481

RESUMO

Machupo virus, the causative agent of Bolivian hemorrhagic fever (BHF), is a highly lethal viral hemorrhagic fever of which little is known and for which no Food and Drug Administration-approved vaccines or therapeutics are available. This study evaluated the cynomolgus macaque as an animal model using the Machupo virus, Chicava strain, via intramuscular and aerosol challenge. The incubation period was 6 to 10 days with initial signs of depression, anorexia, diarrhea, mild fever, and a petechial skin rash. These were often followed by neurologic signs and death within an average of 18 days. Complete blood counts revealed leukopenia as well as marked thrombocytopenia. Serum chemistry values identified a decrease in total protein, marked increases in alanine aminotransferase and aspartate aminotransferase, and moderate increases in alkaline phosphatase. Gross pathology findings included a macular rash extending across the axillary and inguinal regions beginning at approximately 10 days postexposure as well as enlarged lymph nodes and spleen, enlarged and friable liver, and sporadic hemorrhages along the gastrointestinal mucosa and serosa. Histologic lesions consisted of foci of degeneration and necrosis/apoptosis in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, stomach, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system (nonsuppurative encephalitis) was histologically apparent approximately 16 days postexposure and was generally progressive. This study provides insight into the course of Machupo virus infection in cynomolgus macaques and supports the usefulness of cynomolgus macaques as a viable model of human Machupo virus infection.


Assuntos
Arenavirus do Novo Mundo/fisiologia , Febre Hemorrágica Americana/patologia , Glândulas Suprarrenais/patologia , Aerossóis/administração & dosagem , Animais , Modelos Animais de Doenças , Feminino , Febre Hemorrágica Americana/virologia , Humanos , Injeções Intramusculares , Fígado/patologia , Pulmão/patologia , Linfonodos/patologia , Macaca fascicularis , Masculino , Baço/patologia
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