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1.
Sci Total Environ ; 752: 141967, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32892056

RESUMO

Hantavirus Cardiopulmonary Syndrome (HCPS) is a disease with high human lethality rates, whose transmission risk is directly related to the abundance of reservoir rodents. In the Brazilian Atlantic forest, the main reservoirs species, Oligoryzomys nigripes and Necromys lasiurus, are thought to increase in abundance with deforestation. Therefore, forest restoration may contribute to decrease HCPS transmission risk, a topic still unexplored, especially in tropical regions. Aiming at filling this research gap, we quantified the potential of forest restoration, as required by the current environmental legislation, to reduce the abundance of Hantavirus reservoir rodents in the Brazilian Atlantic Forest. Using a dataset on small mammal communities sampled at 104 sites, we modeled how the abundance of these two rodent species change with the percentage of forest cover and forest edge density. From the best model, we extrapolated rodent abundance to the entire Atlantic Forest, considering two scenarios: current and restored forest cover. Comparing the estimated abundance between these two scenarios, we show that forest restoration can reduce the abundance of O. nigripes up to 89.29% in 43.43% of Atlantic forest territory. For N. lasiurus, abundance decreased up to 46% in 44% of the Atlantic forest. To our knowledge, this is the first study linking forest restoration and zoonotic diseases. Our results indicate that forest restoration would decrease the chance of HCPS transmission in ~45% of the Atlantic forest, making the landscape healthier to ~2,8 million people living within this area. This positive effect of restoration on disease regulation should be considered as an additional argument to encourage and promote forest restoration in tropical areas around the world.


Assuntos
Hantavirus , Animais , Brasil , Florestas , Humanos , Roedores , Zoonoses
2.
Chemosphere ; 262: 127800, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32750592

RESUMO

This study aimed to determine the mineral profile of hair samples of free-ranging capybaras (Hydrochoerus hydrochaeris) in remnants of the Atlantic Forest located in the Northeast of Brazil, and to evaluate the effects of origin, gender and age of the animals on their mineral accumulation in hair. Twenty hair samples from animals of different areas, genders and ages were prepared using microwave-assisted digestion, employing 5 mL of HNO3 and 2.5 mL of H2SO4 for 100 mg of sample. Digestion efficiency was assessed by residual carbon content. The digested samples were analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). Principal component analysis (PCA) was performed considering the composition data of 11 elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Mo, and Na). The digestion method applied was efficient and the most abundant elements with their respective concentration ranges in mg kg-1 were Al (396-2746), Ca (36-3420), Fe (476-51180), K (115-4843), and Na (72-473). ANOVA and PCA differentiated among the capybaras regarding age (adults) and origin (A3), both associated with higher concentrations of Al, Cd, Fe, and K. Although a higher metal bioaccumulation was observed in adult animals, it is important to highlight that this result could have been affected by diet and physiological parameters. The results suggest that A3 was the most anthropized remnant area due to agricultural and urban influences. Multi-elemental determination in hair can be used as a non-invasive method to assess heavy metal contamination in capybaras.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Roedores/metabolismo , Oligoelementos/metabolismo , Animais , Brasil , Florestas , Cabelo/química , Metais Pesados/análise , Micro-Ondas , Minerais/análise , Oligoelementos/análise
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3642-3648, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018791

RESUMO

In this study we evaluate the application of video-based markerless motion tracking based on deep neural networks for the analysis of ataxia-specific movement abnormalities in rodent models of cerebellar ataxia. Based on a small amount (<100) of manually labeled video frames, markerless motion tracking enabled the extraction of movement trajectories and parameters characterizing ataxia-specific movement abnormalities. In the first experiment, we analyzed videos of 6 shaker and 4 wildtype rats and were able to reproduce thê5 Hz tremor frequency in the shaker rat without the usage of a force plate. In the second experiment, we investigated a spinocerebellar ataxia type 3 (SCA3) mouse model (6 mice aged 3 months and 3 mice aged 9 months) in a beam-balancing task. By establishing a parameter for the assessment of rhythmicity of gait (RoG), we not only found a significantly higher RoG in wildtype mice compared to affected SCA3 mice aged 9 months, but were also able to reveal a significantly lower than typical RoG in SCA3 mice aged 3 months which exhibit no abnormalities in visual inspection. These prototypical results suggest the capability of the presented methods for the application in upcoming therapeutic intervention trials to identify subtle changes in movement behavior.


Assuntos
Ataxia Cerebelar , Transtornos Motores , Animais , Ataxia , Camundongos , Redes Neurais de Computação , Ratos , Roedores
4.
Zootaxa ; 4766(2): zootaxa.4766.2.5, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33056600

RESUMO

Two new cestodes of the family Hymenolepididae are described from two species of rodents of the family Geomyidae collected in Mexico and Costa Rica. One new species of Hymenolepis is described from Cratogeomys planiceps Merriam 1895 from near Toluca, Mexico and another that we allocate to a new genus is described from Heterogeomys heterodus (Peters, 1865) from near Irazú Volcano, Costa Rica. Hymenolepis s. str. includes those Hymenolepididae with an apical organ, with no hooks on suckers or apical organ, and three testes. Hobergia irazuensis n. gen., n. sp. includes a hymenolepidid with an apical organ, unarmed scolex, small pockets termed foveolae, in which the suckers completely retract, and extremely bi-lobed ovary. Multivariate morphometric analysis showed good separation of these species from all other hymenolepidids possessing an apical organ and lacking a well developed rostellum and rostellar hooks in the Nearctic and Neotropical regions.


Assuntos
Cestoides , Infecções por Cestoides , Doenças dos Roedores , Animais , Costa Rica , Feminino , México , Roedores
5.
Parasitol Res ; 119(11): 3675-3690, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33001253

RESUMO

In 2018, extensive field studies of diversity and prevalence of helminth infection in synanthropic rodents and non-rodent small mammals from public parks and citified areas in the Bangkok Metropolitan were conducted. Rattus rattus complex was the dominant small mammal in public parks. Of the 197 animals, 147 individuals were infected with one or more species of helminths, yielding an infection prevalence of 74.6%. Twenty-five species of helminths were recovered during necropsy. Pterygodermatites tani was the most prevalent (36.2%); other encountered species included Raillietina celebensis, Hydatigera taeniaformis (metacestode in liver tissue), Gongylonema neoplasticum and Hymenolepis diminuta. Different helminth assemblages infected three different host taxa, i.e. synanthropic Rattus spp., Tupaia belangeri (Northern treeshrew) and Suncus murinus (Asian house shrew). Nine species of possible zoonotic helminths were identified. The focus on synanthropic rats influenced the findings of helminth diversity by either host intrinsic or extrinsic factors. A significant positive correlation was found between host body mass and helminth species richness. Greater helminth species richness was found in rats from public parks compared with animals from citified areas (e.g. inside buildings or offices). Also, helminth species richness was negatively correlated with the proportion of post-flooding/rain-fed land. These results provide essential information for assessing the incidence of potential zoonotic health threats in Bangkok and updating research in parasite ecology.


Assuntos
Biota , Helmintíase Animal/parasitologia , Helmintos/classificação , Doenças dos Roedores/parasitologia , Roedores/parasitologia , Animais , Cidades , Inundações , Helmintíase Animal/epidemiologia , Helmintos/isolamento & purificação , Humanos , Parques Recreativos , Prevalência , Ratos , Doenças dos Roedores/epidemiologia , Musaranhos/parasitologia , Tailândia/epidemiologia
6.
PLoS One ; 15(10): e0228762, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33001987

RESUMO

Single-centre studies examining the transgenerational inheritance of pathologies in rodents exposed to pesticides have not always taken important design and analysis issues into account. This paper examines these methodological and statistical issues in detail. Its particular focus is on the estimation of 'litter effects': the tendency for rodents within a litter to be more alike than rodents in different litters. Appropriate statistical models were fitted to published data from a series of widely reported studies carried out at Washington State University. These studies were amalgamated into a single dataset in order to estimate these litter effects and associated treatment effects. Litter effects varied by outcome and were often substantial. Consequently, the effective sample size was often substantially less than the number of observations with implications for the power of the studies. Moreover, the reported precision of the estimates of treatment effects was too low. These problems are exacerbated by unexplained missing data across generations. Researchers in the life sciences could be more cognisant of the guidelines established in medicine for reporting randomised controlled trials, particularly cluster randomised trials. More attention should be paid to the design and analysis of multi-generational rodent studies; their imperfections have important implications for assessments of the evidence relating to the risks of pesticides for public health.


Assuntos
Hereditariedade , Modelos Estatísticos , Projetos de Pesquisa/normas , Roedores , Estruturas Animais/efeitos dos fármacos , Estruturas Animais/patologia , Animais , Humanos , Modelos Animais , Praguicidas/efeitos adversos , Saúde Pública , Tamanho da Amostra , Washington
7.
Korean J Parasitol ; 58(4): 445-450, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32871638

RESUMO

Trombiculid "chigger" mites (Acari) are ectoparasites that feed blood on rodents and another animals. A crosssectional survey was conducted in 7 ecosystems of southern Vietnam from 2015 to 2016. Chigger mites were identified with morphological characteristics and assayed by polymerase chain reaction for detection of rickettsiaceae. Overall chigger infestation among rodents was 23.38%. The chigger index among infested rodents was 19.37 and a mean abundance of 4.61. A total of 2,770 chigger mites were identified belonging to 6 species, 3 genera, and 1 family, and pooled into 141 pools (10-20 chiggers per pool). Two pools (1.4%) of the chiggers were positive for Orientia tsutsugamushi. Ricketsia spp. was not detected in any pools of chiggers. Further studies are needed including a larger number and diverse hosts, and environmental factors to assess scrub typhus.


Assuntos
Orientia tsutsugamushi/isolamento & purificação , Roedores/parasitologia , Trombiculidae/microbiologia , Animais , Estudos Transversais , DNA Bacteriano/genética , Orientia tsutsugamushi/genética , Reação em Cadeia da Polimerase/métodos , Tifo por Ácaros/microbiologia , Trombiculidae/genética , Vietnã
8.
PLoS Negl Trop Dis ; 14(9): e0008652, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32877407

RESUMO

China once suffered greatly from schistosomiasis japonica, a major zoonotic disease. Nearly 70 years of multidisciplinary efforts have achieved great progress in disease control, with infections in both humans and bovines significantly reduced to very low levels. However, reaching for the target of complete interruption of transmission at the country level by 2030 still faces great challenges, with areas of ongoing endemicity and/or re-emergence within previously 'eliminated' regions. The objectives of this study were, by using meta-analytical methods, to estimate the overall prevalence of Schistosoma japonicum infections in abundant commensal rodent species in mainland China after the introduction of praziquantel for schistosomiasis treatment in humans and bovines in 1980s. In doing so we thereby aimed to further assess the role of wild rodents as potential reservoirs in ongoing schistosome transmission. Published studies on infection prevalence of S. japonicum in wild rodents in mainland China since 1980 were searched across five electronic bibliographic databases and lists of article references. Eligible studies were selected based on inclusion and exclusion criteria. Risks of within and across study biases, and the variations in prevalence estimates attributable to heterogeneities were assessed. The pooled infection prevalence and its 95% confidence intervals (CIs) were calculated with the Freeman-Tukey double arcsine transformation. We identified a total of 37 relevant articles involving 61 field studies which contained eligible data on 8,795 wild rodents across mainland China. The overall pooled infection prevalence was 3.86% (95% CI: 2.16-5.93%). No significant change in the overall pooled prevalence was observed between 1980-2003 (n = 23 studies) and 2004-current (n = 38 studies). However, whilst the estimated prevalence decreased over time in the marshland and lake regions, there was an apparent increase in prevalence within hilly and mountainous regions. Among seven provinces, a significant prevalence reduction was only seen in Jiangsu where most endemic settings are classified as the marshland and lakes. These estimates changed over season, ranging from 0.58% in spring to 22.39% in winter, in association with increases in rodent density. This study systematically analyzed S. japonicum infections in wild rodents from the published literature over the last forty years after the introduction of praziquantel for schistosomiasis treatment in humans and bovines in 1980s. Although numbers of schistosomiasis cases in humans and bovines have been greatly reduced, no such comparable overall change of infection prevalence in rodents was detected. Furthermore, there appeared to be an increase in S. japonicum prevalence in rodents over time within hilly and mountainous regions. Rodents have been projected to become the dominant wildlife in human-driven environments and the main reservoir of zoonotic diseases in general within tropical zones. Our findings thus suggest that it is now necessary to include monitoring and evaluation of potential schistosome infection within rodents, particularly in hilly and mountainous regions, if we are ever to reach the new 2030 elimination goals and to maximize the impact of future public, and indeed One Health, interventions across, regional, national and international scales.


Assuntos
Doenças dos Roedores/parasitologia , Esquistossomose Japônica/parasitologia , Esquistossomose Japônica/veterinária , Animais , Animais Selvagens/parasitologia , China/epidemiologia , Humanos , Praziquantel/administração & dosagem , Doenças dos Roedores/tratamento farmacológico , Doenças dos Roedores/epidemiologia , Roedores/parasitologia , Schistosoma japonicum/efeitos dos fármacos , Schistosoma japonicum/genética , Schistosoma japonicum/isolamento & purificação , Schistosoma japonicum/fisiologia , Esquistossomose Japônica/tratamento farmacológico , Esquistossomose Japônica/epidemiologia
9.
PLoS One ; 15(9): e0239870, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991626

RESUMO

The activity-regulated cytoskeleton-associate protein Arc (or Arg3.1) is specifically linked to memory formation and a number of cognitive disorders, including Alzheimer's disease and schizophrenia. Since the discovery of Arc in 1995, extensive research has been conducted on the protein to identify its function and mechanisms of action, with solving the structure of Arc as a major goal. However, the Arc protein tends to self-oligomerize in vitro, and is difficult to crystallize. These properties have hindered efforts to obtain the structure of the full-length, whole protein Arc. As an alternative approach, we and others, have sought to solve the structures of various subdomain proteins of Arc, including the N-lobe, C-lobe, and capsid domain (N-lobe + C-lobe). In this study, we characterized the C-terminal tail of Arc using integrated bioinformatic and structural biology techniques. We compared the sequences of Arc proteins in different mammal species and found that the amino-acid composition in the C-terminal tail region has a significantly higher degree of variation rate than the rest of the protein. Structural prediction programs suggested that the C-terminal tail is structurally disordered. Chemical shift analysis based on solution NMR spectra confirmed that the C-terminal tail has a random coil (disordered) structure, and the tail starts from the residue D357. Furthermore, the NMR spectra showed that the C-terminal tail has minimum (if any) interaction with its neighboring capsid domain in Arc. This study fills gaps in our specific understanding of the structural nature and functional contributions of the Arc C-terminus.


Assuntos
Proteínas do Citoesqueleto/química , Proteínas do Tecido Nervoso/química , Animais , Bovinos , Proteínas do Citoesqueleto/genética , Humanos , Proteínas Intrinsicamente Desordenadas/química , Proteínas do Tecido Nervoso/genética , Primatas , Domínios Proteicos , Roedores , Homologia de Sequência
10.
Anim Sci J ; 91(1): e13440, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32885569

RESUMO

Cytogenetic tests are used to assess the influence of physical and chemical factors with potential mutagenic and genotoxic properties on the animal organism. The test results make it possible to eliminate mutagens, as well as helping predict possible genetic consequences in animal cells and assess animal resistance. The aim of this study was to examine, using cytogenetic tests, the spontaneous chromosome and DNA damage in coypu lymphocytes. Four tests: fragile site (FS), bleomycin (BLM), micronucleus, (MN) and comet were used for the first time in coypu cells. The averages with standard deviations obtained in the research were as follows: 3.30 ± 0.80 fragile sites/cell; 0.63 ± 0.80 BLM damage/cell; 6.10 ± 0.53% binucleated cells with MN; and 3.24 ± 0.63% DNA in tail. The present analysis showed high interindividual variation in spontaneous chromosomal and DNA damage levels. In the case of micronucleus, fragile sites, and comet assays, the differences between animals were statistically significant. The data suggest that these assays are sensitive enough to detect some effects on an individual animal and can be proposed as tools for coypu biomonitoring.


Assuntos
Monitoramento Biológico/métodos , Variação Biológica Individual , Análise Citogenética/métodos , Análise Citogenética/veterinária , Roedores/genética , Animais , Bleomicina , Aberrações Cromossômicas/veterinária , Sítios Frágeis do Cromossomo , Ensaio Cometa/veterinária , Dano ao DNA , Feminino , Linfócitos , Micronúcleos com Defeito Cromossômico
12.
Oecologia ; 193(4): 903-912, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32809054

RESUMO

Dispersal is a fundamental ecological process that can be affected by population density, yet studies report contrasting effects of density on propensity to disperse. In addition, the relationship between dispersal and density is seldom examined using densities measured at different spatial scales or over extensive time series. We used 51 years of trapping data to examine how dispersal by wild deer mice (Peromyscus maniculatus) was affected by changes in both local and regional population densities. We examined these patterns over both the entire time series and also in 10-year shifting windows to determine whether the nature and strength of the relationship changed through time. Probability of dispersal decreased with increased local and regional population density, and the negative effect of local density on dispersal was more pronounced in years with low regional densities. In addition, the strength of negative density-dependent dispersal changed through time, ranging from very strong in some decades to absent in other periods of the study. Finally, while females were less likely to disperse, female dispersal was more density-dependent than male dispersal. Our study shows that the relationship between density and dispersal is not temporally static and that investigations of density-dependent dispersal should consider both local and regional population densities.


Assuntos
Florestas , Roedores , Animais , Feminino , Masculino , Camundongos , Densidade Demográfica , Dinâmica Populacional
13.
PLoS Negl Trop Dis ; 14(8): e0008090, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817670

RESUMO

BACKGROUND: Hantaan virus (HTNV; family Hantaviridae, order Bunyavirales) causes hemorrhagic fever with renal syndrome (HFRS), which has raised serious concerns in Eurasia, especially in China, Russia, and South Korea. Previous studies reported genetic diversity and phylogenetic features of HTNV in different parts of China, but the analyses from the holistic perspective are rare. METHODOLOGY AND PRINCIPAL FINDINGS: To better understand HTNV genetic diversity and gene evolution, we analyzed all available complete sequences derived from the small (S) and medium (M) segments with bioinformatic tools. Eleven phylogenetic groups were defined and showed geographic clustering; 42 significant amino acid variant sites were found, and 19 of them were located in immune epitopes; nine recombinant events and eight reassortments with highly divergent sequences were found and analyzed. We found that sequences from Guizhou showed high genetic divergence, contributing to multiple lineages of the phylogenetic tree and also to the recombination and reassortment events. Bayesian stochastic search variable selection analysis revealed that Heilongjiang, Shaanxi, and Guizhou played important roles in HTNV evolution and migration; the virus may originate from Zhejiang Province in the eastern part of China; and the virus population size expanded from the 1980s to 1990s. CONCLUSIONS/SIGNIFICANCE: These findings revealed the original and evolutionary features of HTNV, which will help to illustrate hantavirus epidemic trends, thus aiding in disease control and prevention.


Assuntos
Evolução Molecular , Variação Genética , Vírus Hantaan/genética , Animais , China/epidemiologia , Genoma Viral , Infecções por Hantavirus/epidemiologia , Humanos , Filogenia , RNA Viral/genética , Roedores , Análise de Sequência de Proteína , Musaranhos
14.
Rev Bras Parasitol Vet ; 29(3): e009420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785526

RESUMO

The broad-headed spiny rat, Clyomys laticeps, is an echimyid rodent found in open areas of Cerrado and Pantanal biomes in central Brazil and Paraguay. Little is known about the parasites associated with this semi-fossorial species, as no previous studies have been conducted on their helminth fauna. The aim of this study was to report the helminth community structure of C. laticeps inhabiting Serra de Caldas Novas State Park, a Cerrado area in central Brazil. Trappings were carried out in dry grasslands from January to October 2016, and the large and small intestines of 14 C. laticeps individuals were examined for the presence of helminths. Three nematode species were found: Fuellebornema almeidai, Pterygodermatites (Paucipectines) sp., and Subulura forcipata, and 85.7% of the studied species were infected with at least one of these helminths. F. almeidai was the most prevalent species among hosts, and S. forcipata was the most abundant. This study is the first report on helminth community structure in C. laticeps. We report a new host species and increase the known geographical range of F. almeidai, and provide the first record of Pterygodermatites (Paucipectines) sp. infecting echimyids. This is also the first report of S. forcipata in a mammal host.


Assuntos
Helmintíase Animal , Helmintos , Roedores , Animais , Brasil , Ecossistema , Helmintíase Animal/parasitologia , Helmintos/classificação , Helmintos/fisiologia , Intestinos/parasitologia , Ratos , Roedores/parasitologia
15.
PLoS One ; 15(8): e0237516, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790738

RESUMO

While metapopulation theory offers tractable means to understand extinction risks for patchily-distributed endangered species, real systems often feature discrepant patch quality and accessibility, complex influences of environmental stochasticity, and regional and temporal autocorrelation. Spatially structured metapopulation models are flexible and can use real data but often at the cost of generality. Particularly as resources for management of such species are often critically limited, endangered species management guided by metapopulation modeling requires incorporation of biological realism. Here we developed a flexible, stochastic spatially structured metapopulation model of the profoundly endangered Amargosa vole, a microtine rodent with an extant population of only a few hundred individuals within 1km2 of habitat in the Mojave Desert. Drought and water insecurity are increasing extinction risks considerably. We modelled subpopulation demographics using a Ricker-like model with migration implemented in an incidence function metapopulation model. A set of scenarios was used to assess the effect of anthropogenic stressors or management actions on expected time to extinction (Te) including: 1) wildland fire, 2) anthropogenically-mediated losses of hydrologic flows, 3) drought, 4) intentional expansion of existing patches into 'megamarshes' (i.e. via restoration/enhancement), and 5) additive impacts of multiple influences. In isolation, marshes could be sources or sinks, but spatial context within the full metapopulation including adjacency could alter relative impacts of subpopulations on all other subpopulations. The greatest reductions in persistence occurred in scenarios simulated with impacts from drought in combination with fire or anthropogenically-mediated losses of hydrologic flows. Optimal actions to improve persistence were to prevent distant and smaller marshes from acting as sinks through strategic creation of megamarshes that act as sources of voles and stepping-stones. This research reinforces that management resources expended without guidance from empirically-based modeling can actually harm species' persistence. This metapopulation-PVA tool could easily be implemented for other patchily-distributed endangered species and allow managers to maximize scarce resources to improve the likelihood of endangered species persistence.


Assuntos
Ecossistema , Espécies em Perigo de Extinção/estatística & dados numéricos , Modelos Biológicos , Modelos Estatísticos , Dinâmica Populacional , Roedores/fisiologia , Animais , Secas , Processos Estocásticos
16.
Methods Mol Biol ; 2203: 33-40, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833201

RESUMO

The recent emergence of SARS, SARS-CoV2 and MERS and the discovery of novel coronaviruses in animals and birds suggest that the Coronavirus family is far more diverse than previously thought. In the last decade, several new coronaviruses have been discovered in rodents around the globe, suggesting that they are the natural reservoirs of the virus. In this chapter we describe the process of screening rodent tissue for novel coronaviruses with PCR, a method that is easily adaptable for screening a range of animals.


Assuntos
Infecções por Coronavirus/virologia , Coronavirus/genética , Reação em Cadeia da Polimerase/métodos , Roedores , Animais , Coronavirus/isolamento & purificação , Infecções por Coronavirus/veterinária
17.
J Vis Exp ; (161)2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32744518

RESUMO

The blood-brain barrier (BBB) has been a major hurdle for the treatment of various brain diseases. Endothelial cells, connected by tight junctions, form a physiological barrier preventing large molecules (>500 Da) from entering the brain tissue. Microbubble-mediated focused ultrasound (FUS) can be used to induce a transient local BBB opening, allowing larger drugs to enter the brain parenchyma. In addition to large-scale clinical devices for clinical translation, preclinical research for therapy response assessment of drug candidates requires dedicated small animal ultrasound setups for targeted BBB opening. Preferably, these systems allow high-throughput workflows with both high-spatial precision as well as integrated cavitation monitoring, while still being cost effective in both initial investment and running costs. Here, we present a bioluminescence and X-ray guided stereotactic small animal FUS system that is based on commercially available components and fulfills the aforementioned requirements. A particular emphasis has been placed on a high degree of automation facilitating the challenges typically encountered in high-volume preclinical drug evaluation studies. Examples of these challenges are the need for standardization in order to ensure data reproducibility, reduce intra-group variability, reduce sample size and thus comply with ethical requirements and decrease unnecessary workload. The proposed BBB system has been validated in the scope of BBB opening facilitated drug delivery trials on patient-derived xenograft models of glioblastoma multiforme and diffuse midline glioma.


Assuntos
Barreira Hematoencefálica/diagnóstico por imagem , Imageamento Tridimensional/métodos , Neuronavegação/métodos , Ultrassonografia/métodos , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Roedores
18.
Artigo em Inglês | MEDLINE | ID: mdl-32756497

RESUMO

Antimicrobial resistance (AMR) in Escherichia coli (E. coli) poses a public health concern worldwide. Wild birds and rodents, due to their mobility, are potential vehicles for transmission of AMR bacteria to humans. Ninety-six wild birds' faecal samples and 135 rodents' droppings samples were collected and analysed in 2017. Forty-six E. coli isolates from wild birds and rodents were subjected to AMR phenotypic and genotypic characterisation. The proportion of E. coli isolates resistant to at least one of the antimicrobials tested from wild birds (80.8%) was significantly higher than that of isolates from rodents (40.0%). The proportion of E. coli isolates resistant to each antimicrobial class for wild birds was 3.8% to 73.1% and that for rodents was 5.0% to 35.0%. Six out of 26 E. coli isolates from wild birds (23.1%) and two out of 20 (10.0%) isolates from rodents were multi-drug resistant (MDR) strains. These MDR E. coli isolates were detected with various antimicrobial resistance genes such as blaTEM-1B and qnrS1 and could be considered as part of the environmental resistome. Findings in this study suggested that wild birds and rodents could play a role in disseminating antimicrobial resistant E. coli, and this underscores the necessity of environment management and close monitoring on AMR bacteria in wild birds and rodents to prevent spreading of resistant organisms to other wildlife animals and humans.


Assuntos
Farmacorresistência Bacteriana , Infecções por Escherichia coli , Escherichia coli , Animais , Antibacterianos/farmacologia , Aves/microbiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Humanos , Roedores/microbiologia , Singapura
19.
PLoS Negl Trop Dis ; 14(8): e0008589, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845889

RESUMO

Accurate data on the Lassa virus (LASV) human case fatality rate (CFR) and the prevalence of LASV in humans, rodents and other mammals are needed for better planning of actions that will ultimately reduce the burden of LASV infection in sub-Saharan Africa. In this systematic review with meta-analysis, we searched PubMed, Scopus, Africa Journal Online, and African Index Medicus from 1969 to 2020 to obtain studies that reported enough data to calculate LASV infection CFR or prevalence. Study selection, data extraction, and risk of bias assessment were conducted independently. We extracted all measures of current, recent, and past infections with LASV. Prevalence and CFR estimates were pooled using a random-effect meta-analysis. Factors associated with CFR, prevalence, and sources of between-study heterogeneity were determined using subgroup and metaregression analyses. This review was registered with PROSPERO, CRD42020166465. We initially identified 1,399 records and finally retained 109 reports that contributed to 291 prevalence records from 25 countries. The overall CFR was 29.7% (22.3-37.5) in humans. Pooled prevalence of LASV infection was 8.7% (95% confidence interval: 6.8-10.8) in humans, 3.2% (1.9-4.6) in rodents, and 0.7% (0.0-2.3) in other mammals. Subgroup and metaregression analyses revealed a substantial statistical heterogeneity explained by higher prevalence in tissue organs, in case-control, in hospital outbreak, and surveys, in retrospective studies, in urban and hospital setting, in hospitalized patients, and in West African countries. This study suggests that LASV infections is an important cause of death in humans and that LASV are common in humans, rodents and other mammals in sub-Saharan Africa. These estimates highlight disparities between sub-regions, and population risk profiles. Western Africa, and specific key populations were identified as having higher LASV CFR and prevalence, hence, deserving more attention for cost-effective preventive interventions.


Assuntos
Febre Lassa/epidemiologia , Febre Lassa/veterinária , Vírus Lassa , África ao Sul do Saara/epidemiologia , Animais , Bases de Dados Factuais , Hospitais , Humanos , Febre Lassa/virologia , Mamíferos , Prevalência , Roedores
20.
An Acad Bras Cienc ; 92(4): e20190981, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32844989

RESUMO

An emerging area in schizophrenia research focuses on the impact of immunomodulatory drugs such as melatonin, which have played important roles in many biological systems and functions, and appears to be promising. The objective was to evaluate the effect of melatonin on behavioral parameters in an animal model of schizophrenia. For this, Wistar rats were divided and used in two different protocols. In the prevention protocol, the animals received 1 or 10mg/kg of melatonin or water for 14 days, and between the 8th and 14th day they received ketamine or saline. In the reversal protocol, the opposite occurred. On the 14th day, the animals underwent behavioral tests: locomotor activity and prepulse inhibition task. In both protocols, the results revealed that ketamine had effects on locomotor activity and prepulse inhibition, confirming the validity of ketamine construction as a good animal model of schizophrenia. However, at least at the doses used, melatonin was not able to reverse/prevent ketamine damage. More studies are necessary to evaluate the role of melatonin as an adjuvant treatment in psychiatric disorders.


Assuntos
Suplementos Nutricionais , Melatonina , Esquizofrenia , Animais , Comportamento Animal , Modelos Animais de Doenças , Melatonina/farmacologia , Ratos , Ratos Wistar , Roedores , Esquizofrenia/tratamento farmacológico
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