RESUMO
Previous clinical studies indicate that monoamine oxidase-B (MAO-B) inhibition by blackcurrants must be predominantly attributed to bioactives other than anthocyanins. In this natural products discovery study, MAO-A/B inhibitory phytochemicals were isolated from blackcurrants, and a double-blind crossover study investigated the efficacy of freeze-dried whole-fruit blackcurrant powder in inhibiting MAO-B compared with blackcurrant juice in healthy adults. Platelet MAO-B inhibition was comparable between powder (89% ± 6) and juice (91% ± 4), and it was positively correlated with MAO-modulated plasma catecholamines, subjective alertness, and reduced mental fatigue, assessed using the Bond-Lader questionnaire. Sarmentosin, a nitrile glycoside, and its hydroxycinnamoyl esters were identified as novel MAO-A/B inhibitors from blackcurrant in vitro, and sarmentosin was demonstrated to inhibit platelet MAO-B activity in vivo. These findings confirm sarmentosin as the primary bioactive for MAO-A/B inhibition in blackcurrants, as well as its bioavailability and stability during freeze-drying, and suggest that consuming blackcurrant powder and juice may positively affect mood in healthy adults.
Assuntos
Plaquetas , Estudos Cross-Over , Inibidores da Monoaminoxidase , Monoaminoxidase , Extratos Vegetais , Ribes , Humanos , Ribes/química , Adulto , Masculino , Monoaminoxidase/metabolismo , Inibidores da Monoaminoxidase/farmacologia , Inibidores da Monoaminoxidase/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Feminino , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Plaquetas/metabolismo , Adulto Jovem , Método Duplo-Cego , Frutas/química , Pessoa de Meia-IdadeRESUMO
Background: Dietary restrictions or reductions such as fasting for weight loss are often difficult to adhere to due to increased appetite and food cravings. Recently, gastrointestinal delivery of bitter hops has been shown to be effective at reducing appetite in men. Our aim was to determine the effect of a bitter hop extract on appetite and cravings in women, using a 24 h, water-only fast. Methods: This was a randomized, double-blind, cross-over treatment study. Thirty adult women were recruited and required to fast for 24 h from 1800 h to 1800 h on three occasions and given an ad libitum meal to break each fast. Treatments of either a placebo or one of two doses (high dose; HD: 250 mg or low dose; LD: 125 mg) of a bitter hop-based appetite suppressant (Amarasate®) were given twice per day at 16 and 20 h into the fast. Results: The HD and LD treatment groups exhibited a significant (p < 0.05) reduction in appetite and cravings for food when compared to the placebo control. Two participants reported loose stools and one reported heartburn while on the HD treatment, and one participant reported loose stools while on the LD treatment. Conclusion: These data suggest that appetite suppressant co-therapy may be useful in reducing hunger during fasting in women and shows that gastrointestinal delivery of bitter compounds may also be an effective method of reducing cravings for food.This trial received ethical approval from the Northen B New Zealand Human Disability and Ethics committee (Northern B Health and Disability Ethics Committee (2022 EXP 10995) and was prospectively registered with the Australian New Zealand Clinical Trial Registry (ACTRN12622000107729).
RESUMO
Elizabethkingia anophelis MSU001, isolated from Anopheles stephensi in the laboratory, was characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-ToF/MS), biochemical testing, and genome sequencing. Average nucleotide identity analysis revealed 99% identity with the type species E. anophelis R26. Phylogenetic placement showed that it formed a clade with other mosquito-associated strains and departed from a clade of clinical isolates. Comparative genome analyses further showed that it shared at least 98.6% of genes with mosquito-associated isolates (except E. anophelis As1), while it shared at most 88.8% of common genes with clinical isolates. Metabolites from MSU001 significantly inhibited growth of E. coli but not the mosquito gut symbionts Serratia marcescens and Asaia sp. W12. Insect-associated E. anophelis carried unique glycoside hydrolase (GH) and auxiliary activities (AAs) encoding genes distinct from those of clinical isolates, indicating their potential role in reshaping chitin structure and other components involved in larval development or formation of the peritrophic matrix. Like other Elizabethkingia, MSU001 also carried abundant genes encoding two-component system proteins (51), transcription factor proteins (188), and DNA-binding proteins (13). E. anophelis MSU001 contains a repertoire of antibiotic resistance genes and several virulence factors. Its potential for opportunistic infections in humans should be further evaluated prior to implementation as a paratransgenesis agent (by transgenesis of a symbiont of the vector).
RESUMO
Implementation of long-lasting insecticide-treated net (LLIN) programs to control human malaria transmission leads to substantial reductions in the abundance of Anopheles mosquitoes, but the impact on the population genetic structure of the malaria vectors is poorly known, nor has it been investigated in Papua New Guinea, where malaria is highly endemic and where several species of Anopheles have vector roles. Here, we applied Wright's F-statistic, analysis of molecular variance, Bayesian structure analysis, and discriminant analysis of principle components to microsatellite genotype data to analyze the population genetic structure of Anopheles farauti between and within the northern and southern lowland plains and of Anopheles punctulatus within the northern plain of Papua New Guinea after such a program. Bottleneck effects in the two malaria vectors were analyzed using Luikart and Cornuet's tests of heterozygosity. A large, panmictic population of An. punctulatus pre-LLIN program diverged into two subregional populations corresponding to Madang and East Sepik provinces post-LLIN distribution and experienced a genetic bottleneck during this process. By contrast, the An. farauti population existed as two regional populations isolated by mountain ranges pre-LLIN, a genetic structure that persisted after the distribution of LLINs with no further geographic differentiation nor evidence of a genetic bottleneck. These findings show the differential response of populations of different vector species to interventions, which has implications for program sustainability and gene flow.
RESUMO
BACKGROUND: Spatial repellents (SR) may complement current vector control tools and provide additional coverage when people are not under their bednets or are outdoors. Here we assessed the efficacy of a metofluthrin-based SR in reducing exposure to pyrethroid-resistant Anopheles funestus in Siaya County, western Kenya. METHODS: Metofluthrin was vaporized using an emanator configured to a liquid petroleum gas (LPG) canister, placed inside experimental huts (phase 1) or outdoors (phase 2), and evaluated for reductions in human landing rate, density, knockdown and mortality rates of An. funestus, which are present in high density in the area. To demonstrate the mosquito recruiting effect of LPG, a hut with only an LPG cooker but no metofluthrin was added as a comparator and compared with an LPG cooker burning alongside the emanator and a third hut with no LPG cooker as control. Phase 2 evaluated the protective range of the SR product while emanating from the centre of a team of mosquito collectors sitting outdoors in north, south, east and west directions at 5, 10 and 20 feet from the emanating device. RESULTS: Combustion of LPG with a cook stove increased the density of An. funestus indoors by 51% over controls with no cook stove. In contrast, huts with metofluthrin vaporized with LPG combustion had lower indoor density of An. funestus (99.3% less than controls), with knockdown and mortality rates of 95.5 and 87.7%, respectively, in the mosquitoes collected in the treated huts. In the outdoor study (phase 2), the outdoor landing rate was significantly lower at 5 and 10 feet than at 20 feet from the emanator. CONCLUSIONS: Vaporized metofluthrin almost completely prevented An. funestus landing indoors and led to 10 times lower landing rates within 10 feet of the emanator outdoors, the first product to demonstrate such potential. Cooking with LPG inside the house could increase exposure to Anopheles mosquito bites, but the use of the metofluthrin canister eliminates this risk.
Assuntos
Anopheles , Repelentes de Insetos , Malária , Piretrinas , Animais , Humanos , Piretrinas/farmacologia , Controle de Mosquitos , Mosquitos Vetores , Quênia , Repelentes de Insetos/farmacologiaRESUMO
The draft genome of Flavobacterium tructae strain S12, isolated from hatchery-reared Chinook salmon (Oncorhynchus tshawytscha) fingerlings, consisted of 5,695,942 bp, a G + C content of 35.6%, 4,775 predicted open reading frames, a putative type IX secretion system, collagenase, and hemolysin. F. tructae strains can be used as models for emerging Flavobacterium pathogens.
RESUMO
Snowshoe hare virus (SSHV), within the California serogroup of the genus Orthobunyavirus, family Peribunyaviridae, was first isolated from a snowshoe hare (Lepus americanus) in Montana, United States, in 1959. The virus, closely related to LaCrosse virus (LACV) and Chatanga virus (CHATV), occurs across Canada and the northern latitudes of the United States, primarily in the northern tier of states bordering Canada. Reports of SSHV in northern Europe and Asia are probably the closely related to CHATV, or the less closely related Tahyna virus. Vertebrate associations include snowshoe hares and ground squirrels, demonstrated by field isolation of virus from wild-caught animals, seroconversion of snowshoe hares, seroconversion of sentinel rabbits, isolation of virus from sentinel rabbits, and experimental infections demonstrating viremia. Isolations of virus from field populations of mosquitoes include primarily univoltine and boreal mosquitoes of the genus Aedes, Culiseta impatiens and Culiseta inornata; and, rarely, certain multivoltine floodwater Aedes species. Experimental transmission studies in mosquitoes show infection in and transmission by boreal Aedes and Culiseta inornata. Isolation of SSHV from larval Aedes on three occasions, and experimentation in Culiseta inornata, reveal transovarial transmission of the virus in mosquitoes. Serosurveys reveal exposure to SSHV in human and domestic animals, with rates of seropositivity commonly high in some settings in Alaska and Canada, but disease in humans or horses has rarely been reported, only in Canada.
Assuntos
Aedes , Vírus da Encefalite da Califórnia , Lebres , Animais , Coelhos , Humanos , Cavalos , Mosquitos Vetores , Animais Selvagens , SciuridaeRESUMO
Disease advocacy organisations (DAOs) are critical for raising awareness about illnesses and supporting research. While most studies of DAOs focus on personally affected patient-activists, an underappreciated constituency are external allies. Building from social movement theory, we distinguish between beneficiary constituents (disease patients and their loved ones) and conscience constituents (allies) and investigate their relative fundraising effectiveness. While the former have credibility due to illness experience that should increase fundraising, the latter are more numerous. Our study is also the first to investigate where DAO supporters fundraise-through friendship- versus workplace-based networks-and how this interacts with constituent types. Our large-scale dataset includes 9372 groups (nearly 90,000 participants) active in the 'Movember' campaign, a men's health movement around testicular and prostate cancer. We find robust evidence that groups with more beneficiary constituents raise significantly greater funds per participant. Yet because conscience constituents are more numerous, they raise the majority of total aggregate funds. We also find an interaction effect: beneficiary constituents do better in friendship networks, conscience constituents in workplaces. Our findings bear implications for DAOs, indicating they may benefit by encouraging disease patient families to fundraise through friends, and for external allies to focus requests on workplace networks.
Assuntos
Consciência , Neoplasias da Próstata , Masculino , Humanos , Local de Trabalho , Condições de Trabalho , Saúde do HomemRESUMO
BACKGROUND: Control of malaria parasite transmission can be enhanced by understanding which human demographic groups serve as the infectious reservoirs. Because vector biting can be heterogeneous, some infected individuals may contribute more to human-to-mosquito transmission than others. Infection prevalence peaks in school-age children, but it is not known how often they are fed upon. Genotypic profiling of human blood permits identification of individual humans who were bitten. The present investigation used this method to estimate which human demographic groups were most responsible for transmitting malaria parasites to Anopheles mosquitoes. It was hypothesized that school-age children contribute more than other demographic groups to human-to-mosquito malaria transmission. METHODS: In a region of moderate-to-high malaria incidence in southeastern Malawi, randomly selected households were surveyed to collect human demographic information and blood samples. Blood-fed, female Anopheles mosquitoes were sampled indoors from the same houses. Genomic DNA from human blood samples and mosquito blood meals of human origin was genotyped using 24 microsatellite loci. The resultant genotypes were matched to identify which individual humans were sources of blood meals. In addition, Plasmodium falciparum DNA in mosquito abdomens was detected with polymerase chain reaction. The combined results were used to identify which humans were most frequently bitten, and the P. falciparum infection prevalence in mosquitoes that resulted from these blood meals. RESULTS: Anopheles females selected human hosts non-randomly and fed on more than one human in 9% of the blood meals. Few humans contributed most of the blood meals to the Anopheles vector population. Children ≤ 5 years old were under-represented in mosquito blood meals while older males (31-75 years old) were over-represented. However, the largest number of malaria-infected blood meals was from school age children (6-15 years old). CONCLUSIONS: The results support the hypothesis that humans aged 6-15 years are the most important demographic group contributing to the transmission of P. falciparum to the Anopheles mosquito vectors. This conclusion suggests that malaria control and prevention programmes should enhance efforts targeting school-age children and males.
Assuntos
Anopheles , Sangue , Comportamento de Busca por Hospedeiro , Malária Falciparum , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Anopheles/parasitologia , DNA/sangue , Genótipo , Malária/sangue , Malária/parasitologia , Malária/prevenção & controle , Malária/transmissão , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Malária Falciparum/prevenção & controle , Malária Falciparum/transmissão , Refeições , Mosquitos Vetores/parasitologia , Plasmodium falciparum/genética , Sangue/parasitologia , MalauiRESUMO
West Nile virus (WNV) is prevalent in the United States but shows considerable variation in transmission intensity. The purpose of this study was to compare patterns of WNV seroprevalence in avian communities sampled in Atlanta, Georgia and Chicago, Illinois during a 12-year period (Atlanta 2010-2016; Chicago 2005-2012) to reveal regional patterns of zoonotic activity of WNV. WNV antibodies were measured in wild bird sera using ELISA and serum neutralization methods, and seroprevalence among species, year, and location of sampling within each city were compared using binomial-distributed generalized linear mixed-effects models. Seroprevalence was highest in year-round and summer-resident species compared with migrants regardless of region; species explained more variance in seroprevalence within each city. Northern cardinals were the species most likely to test positive for WNV in each city, whereas all other species, on average, tested positive for WNV in proportion to their sample size. Despite similar patterns of seroprevalence among species, overall seroprevalence was higher in Atlanta (13.7%) than in Chicago (5%). Location and year of sampling had minor effects, with location explaining more variation in Atlanta and year explaining more variation in Chicago. Our findings highlight the nature and magnitude of regional differences in WNV urban ecology.
Assuntos
Doenças das Aves , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Anticorpos Antivirais , Doenças das Aves/epidemiologia , Aves , Chicago/epidemiologia , Georgia/epidemiologia , Illinois/epidemiologia , Prevalência , Estudos Soroepidemiológicos , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterináriaRESUMO
BACKGROUND: Despite the scale-up of insecticide-treated nets and indoor residual spraying, the bulk of malaria transmission in western Kenya still occurs indoors, late at night. House improvement is a potential long-term solution to further reduce malaria transmission in the region. METHODS: The impact of eave screening on mosquito densities was evaluated in two rural villages in western Kenya. One-hundred-and-twenty pairs of structurally similar, neighbouring houses were used in the study. In each pair, one house was randomly selected to receive eave screening at the beginning of the study while the other remained unscreened until the end of the sampling period. Mosquito sampling was performed monthly by motorized aspiration method for 4 months. The collected mosquitoes were analysed for species identification. RESULTS: Compared to unscreened houses, significantly fewer female Anopheles funestus (RR = 0.40, 95% CI 0.29-0.55), Anopheles gambiae Complex (RR = 0.46, 95% CI 0.34-0.62) and Culex species (RR = 0.53, 95% CI 0.45-0.61) were collected in screened houses. No significant differences in the densities of the mosquitoes were detected in outdoor collections. Significantly fewer Anopheles funestus were collected indoors from houses with painted walls (RR = 0.05, 95% CI 0.01-0.38) while cooking in the house was associated with significantly lower numbers of Anopheles gambiae Complex indoors (RR = 0.60, 95% CI 0.45-0.79). Nearly all house owners (99.6%) wanted their houses permanently screened, including 97.7% that indicated a willingness to use their own resources. However, 99.2% required training on house screening. The cost of screening a single house was estimated at KES6,162.38 (US$61.62). CONCLUSION: Simple house modification by eave screening has the potential to reduce the indoor occurrence of both Anopheles and Culex mosquito species. Community acceptance was very high although education and mobilization may be needed for community uptake of house modification for vector control. Intersectoral collaboration and favourable government policies on housing are important links towards the adoption of house improvements for malaria control.
Assuntos
Anopheles , Culex , Inseticidas , Malária , Humanos , Animais , Feminino , Mosquitos Vetores , Quênia , Malária/prevenção & controle , Habitação , Controle de Mosquitos/métodosRESUMO
Malaria remains a threat to public health in Malawi. It is well acknowledged that malaria research and robust evidence can have an impact on malaria policy and practice, resulting in positive population health gains. We report policy-relevant research contributions that the Malawi International Center of Excellence for Malaria Research (ICEMR) in partnership with local and international collaborators has made. Findings from our ICEMR studies have shown that long-lasting insecticide-treated bed nets (LLINs) impregnated with piperonyl butoxide reduced mosquito blood feeding more compared with conventional LLINs. On the other hand, we showed that few LLINs are maintained up to the end of their 3-year life span, and that older nets are less effective. These results support the policy change decisions by the Malawi National Malaria Control Program to switch from conventional LLINs to piperonyl butoxide LLINs, and to conduct mass LLIN distribution campaigns every 2 years. Our studies on epidemiological patterns of malaria infection showed that school-age children have higher malaria infection rates and lower use of control measures compared with younger children and adults. These findings added to the evidence base that influenced the National Malaria Control Program to endorse school-based malaria interventions as part of its national policy. Research supported by the Malawi ICEMR is contributing to in-country policy decisions and to the implementation of evidence-based interventions. Through our long-term studies we intend to continue providing practical and policy-relevant evidence necessary, ultimately, to eliminate malaria infection in Malawi.
Assuntos
Mosquiteiros Tratados com Inseticida , Malária , Adulto , Animais , Criança , Política de Saúde , Humanos , Resistência a Inseticidas , Malária/epidemiologia , Malária/prevenção & controle , Malaui/epidemiologia , Controle de Mosquitos/métodos , Butóxido de PiperonilaRESUMO
Despite the scale-up of interventions against malaria over the past decade, this disease remains a leading threat to health in Malawi. To evaluate the epidemiology of both Plasmodium falciparum infection and malaria disease, the Malawi International Center of Excellence for Malaria Research (ICEMR) has developed and implemented diverse and robust surveillance and research projects. Descriptive studies in ICEMR Phase 1 increased our understanding of the declining effectiveness of long-lasting insecticidal nets (LLINs), the role of school-age children in malaria parasite transmission, and the complexity of host-parasite interactions leading to disease. These findings informed the design of ICEMR Phase 2 to test hypotheses about LLIN use and effectiveness, vector resistance to insecticides, demographic targets of malaria control, patterns and causes of asymptomatic to life-threatening disease, and the impacts of RTS,S vaccination plus piperonyl butoxide-treated LLINs on infection and disease in young children. These investigations are helping us to understand mosquito-to-human and human-to-mosquito transmission in the context of Malawi's intransigent malaria problem.
Assuntos
Mosquiteiros Tratados com Inseticida , Inseticidas , Malária , Animais , Criança , Pré-Escolar , Humanos , Resistência a Inseticidas , Inseticidas/farmacologia , Inseticidas/uso terapêutico , Malária/epidemiologia , Malária/prevenção & controle , Malaui/epidemiologia , Controle de Mosquitos , Mosquitos Vetores/parasitologia , Butóxido de PiperonilaRESUMO
Dengue virus (DENV) is a highly prevalent vector-borne virus that causes life-threatening illnesses to humans worldwide. The development of a tool to control vector populations has the potential to reduce the burden of DENV. Toxic sugar bait (TSB) provides a form of vector control that takes advantage of the sugar-feeding behavior of adult mosquitoes. However, studies on the effect of ingestion of toxins in TSB on vector competence and vectorial capacity for viruses are lacking. This study evaluated vector competence for DENV serotype-1 of Aedes albopictus at 7 and 14 days post-ingestion of TSB formulated with spinosad (of bacteria origin) as an oral toxin. Our results and others were modeled to estimate effects on Ae. albopictus vectorial capacity for DENV. Ingestion of TSB caused a reduction in survival of females, but increased mosquito susceptibility to DENV infection, disseminated infection, and transmission. However, this increase in vector competence was obviated by the reduction in survival, leading to a lower predicted vectorial capacity. The findings of this study highlight the importance of evaluating the net impact of TSB ingestion on epidemiological parameters of vectorial capacity in the context of vector control efforts to reduce the risk of transmission of vector-borne viruses.
RESUMO
BACKGROUND: Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control interventions on molecular markers of Plasmodium falciparum drug resistance using parasites obtained from humans and mosquitoes at discrete time points. METHODS: Dried blood spot samples collected in 2012 and 2017 community surveys in Asembo, Kenya were genotyped by Sanger sequencing for markers associated with resistance to SP (Pfdhfr, Pfdhps), CQ, AQ, lumefantrine (Pfcrt, Pfmdr1) and artemisinin (Pfk13). Temporal trends in the prevalence of these markers, including data from 2012 to 2017 as well as published data from 1996, 2001, 2007 from same area, were analysed. The same markers from mosquito oocysts collected in 2012 were compared with results from human blood samples. RESULTS: The prevalence of SP dhfr/dhps quintuple mutant haplotype C50I51R59N108I164/S436G437E540A581A613 increased from 19.7% in 1996 to 86.0% in 2012, while an increase in the sextuple mutant haplotype C50I51R59N108I164/H436G437E540A581A613 containing Pfdhps-436H was found from 10.5% in 2012 to 34.6% in 2017. Resistant Pfcrt-76 T declined from 94.6% in 2007 to 18.3% in 2012 and 0.9% in 2017. Mutant Pfmdr1-86Y decreased across years from 74.8% in 1996 to zero in 2017, mutant Pfmdr1-184F and wild Pfmdr1-D1246 increased from 17.9% to 58.9% in 2007 to 55.9% and 90.1% in 2017, respectively. Pfmdr1 haplotype N86F184S1034N1042D1246 increased from 11.0% in 2007 to 49.6% in 2017. No resistant mutations in Pfk13 were found. Prevalence of Pfdhps-436H was lower while prevalence of Pfcrt-76 T was higher in mosquitoes than in human blood samples. CONCLUSION: This study showed an increased prevalence of dhfr/dhps resistant markers over 20 years with the emergence of Pfdhps-436H mutant a decade ago in Asembo. The reversal of Pfcrt from CQ-resistant to CQ-sensitive genotype occurred following 19 years of CQ withdrawal. No Pfk13 markers associated with artemisinin resistance were detected, but the increased haplotype of Pfmdr1 N86F184S1034N1042D1246 was observed. The differences in prevalence of Pfdhps-436H and Pfcrt-76 T SNPs between two hosts and the role of mosquitoes in the transmission of drug resistant parasites require further investigation.
Assuntos
Antimaláricos , Artemisininas , Culicidae , Malária Falciparum , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemeter/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Artemisininas/uso terapêutico , Biomarcadores , Cloroquina/farmacologia , Resistência a Medicamentos/genética , Humanos , Quênia/epidemiologia , Malária Falciparum/parasitologia , Mosquitos Vetores , Oocistos , Plasmodium falciparum/genética , Tetra-Hidrofolato Desidrogenase/genéticaRESUMO
Two Culex pipiens form Pipiens colony strains and a field population of Cx. restuans from Michigan were susceptible and a Cx. pipiens form Molestus colony strain was comparatively less susceptible to a dose of 43 µg/ml of permethrin in Centers for Disease Control and Prevention (CDC) bottle bioassays. Using this diagnostic dose and these populations as controls, adult female Cx. pipiens and Cx. restuans were reared from egg rafts from 28 sites in Illinois, Ohio, Michigan, Iowa, Indiana, Wisconsin, and Minnesota. Tested mosquitoes showed high mortality in populations from 12 sites, less mortality (90-96%) at 9 sites, and less than 90% mortality from 7 sites during 30-min exposures. However, all tested populations showed 97-100% mortality at 60 min, indicating low phenotypic penetrance of resistance factors. These results indicate variation in susceptibility to permethrin in populations of West Nile virus vectors in the Great Lakes region of the United States, with evidence of modest resistance at 7 of 28 (25%) of the sampled populations.
Assuntos
Culex , Vírus do Nilo Ocidental , Animais , Feminino , Great Lakes Region , Mosquitos Vetores , Permetrina , Estados UnidosRESUMO
Loneliness has emerged as a problem for individuals and society. A group whose loneliness has recently grown in severity and visibility is students in higher education. Complementing media reports and surveys of students' lockdown loneliness, this paper presents qualitative research findings on students loneliness during the COVID-19 pandemic. It explores the how, why and where of student loneliness through research co-produced with undergraduate and postgraduate students. Student-researchers investigated loneliness as a function of relationships and interactions through self-interviews and peer interviews (n = 46) and through objects, chosen by participants to represent their experiences of lockdown. This research led to three conclusions, each with a geographical focus. First, as the spaces in which students live and study were fragmented, interactions and relationships were disrupted. Second, students struggled to put down roots in their places of study. Without a sense of belonging-to the city and institution where they studied, and the neighbourhood and accommodation where they lived-they were more likely to experience loneliness. Third, many students were unable to progress through life transitions associated with late adolescence including leaving home, learning social skills, forming sexual relationships and emerging into adulthood. Those facing bigger changes such as bereavement struggled to process these events and spoke of feeling 'neither here nor there'-in limbo. But students displayed resilience, finding ways to cope with and mitigate their loneliness. Their coping strategies speak to the efforts of policymakers and practitioners-including those in universities, government, health and wellbeing services, and accommodation services-who are seeking ways to tackle students' (and other peoples') loneliness.
RESUMO
There is a surprising lack of evidence documenting the volumetric symmetry of the bony orbit. This paper establishes reference values for orbital volume (OV) and symmetry in the 25 - 40 year old caucasian population. Secondarily, this paper sets a landmark for the tolerances in OV that can be expected when reconstructing the bony defects which may occur from trauma. A standardised method of quantitative OV measurement was developed using CT sinus examinations acquired for indications unrelated to orbital trauma. Sex, ethnicity, age, right and left OV were recorded. Data for 100 patients was obtained (50 male, 50 female). Mean left OV was 23.1cm3 and mean right OV was 23.3cm3. Left and right OV were strongly positively correlated (correlation coefficient: 0.96). Mean female OV was 21.6cm3 and mean male OV was 24.8cm3. On average, male OV is 3.2cm3 larger than female OV. The mean difference between left and right OV was 0.5cm3 in females and 0.6cm3 in males. The intra-class coefficient score between the two assessors was 0.973 (excellent). There is strong positive correlation between left and right OV in this study population. Previous work suggests that orbital volume loss less than 1cm3 would not lead to significant clinical symptoms of orbital fracture. When orbital reconstruction is undertaken, this study suggests that a volume symmetry difference of <0.5cm3 in females and <0.6cm3 in males would be consistent with the variation seen in the study population of uninjured caucasian 25-40 year olds and is therefore a reasonable goal of surgical management.
Assuntos
Traumatismos Oculares , Fraturas Orbitárias , Procedimentos de Cirurgia Plástica , Adulto , Traumatismos Oculares/cirurgia , Feminino , Humanos , Masculino , Órbita/diagnóstico por imagem , Órbita/cirurgia , Fraturas Orbitárias/diagnóstico por imagem , Fraturas Orbitárias/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Tomografia Computadorizada por Raios XRESUMO
There is a growing epidemic of thyroid nodules, commonly detected as incidental imaging findings. The vast majority of nodules are benign and of primary thyroidal origin. However, a multitude of non-native, extrinsic or systemic conditions may affect the thyroid and mimic primary thyroid nodules. Contributing factors may include the glands' location in an anatomically dense area, rich vascular and lymphatic network, and embryological origin. In this article we describe a variety of extrinsic and unusual pathology which can affect the thyroid gland. Conditions are classified into benign congenital, benign acquired, cancers which secondarily involve the thyroid gland and unusual cancers arising from within the gland itself. The imaging findings, primarily on high-resolution ultrasound, are reviewed and illustrated with examples. Where possible, imaging features which suggest a specific pathological category or entity are highlighted. It is important that those performing ultrasound examination of the thyroid gland are aware that thyroid nodules may not exclusively represent pathology native or intrinsic to the gland itself.
Assuntos
Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Diagnóstico por Imagem , Humanos , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Ultrassonografia/métodosRESUMO
BACKGROUND: Access to human hosts by Anopheles mosquitoes is a key determinant of vectorial capacity for malaria, but it can be limited by use of long-lasting insecticidal nets (LLINs). In Malawi, pyrethroid-treated LLINs with and without the synergist piperonyl butoxide (PBO) were distributed to control malaria. This study investigated the blood-feeding patterns of malaria vectors and whether LLINs containing pyrethroid and PBO led to a reduction of human blood feeding than those containing only pyrethroids. METHODS: Mosquitoes were sampled inside houses from May 2019 through April 2020 by aspiration, pyrethrum spray catch, and light trap methods in two sites. One site (Namanolo, Balaka district) had LLINs containing only pyrethroids whereas the other (Ntaja, Machinga district) had LLINs with both pyrethroids and PBO. Anopheles species, their blood-meal host, and infection with Plasmodium falciparum were determined using PCR methods. RESULTS: A total of 6585 female Anopheles were sampled in 203 houses. Of these, 633 (9.6%) were blood-fed mosquitoes comprising of 279 (44.1%) Anopheles arabiensis, 103 (16.3%) Anopheles gambiae 212 (33.5), Anopheles funestus, 2 (0.3%), Anopheles parensis and 37 (5.8%) were unidentified Anopheles spp. Blood meal hosts were successfully identified for 85.5% (n = 541) of the blood-fed mosquitoes, of which 436 (81.0%) were human blood meals, 28 (5.2%) were goats, 11 (2.0%) were dogs, 60 (11.1%) were mixed goat-human blood meals, 5 (0.9%) were dog-human, and 1 was a mixed dog-goat. Human blood index (fraction of blood meals that were humans) was significantly higher in Namanolo (0.96) than Ntaja (0.89). Even though human blood index was high, goats were over-selected than humans after accounting for relative abundance of both hosts. The number of infectious Anopheles bites per person-year was 44 in Namanolo and 22 in Ntaja. CONCLUSION: Although LLINs with PBO PBO may have reduced human blood feeding, access to humans was extremely high despite high LLIN ownership and usage rates in both sites. This finding could explain persistently high rates of malaria infections in Malawi. However, this study had one village for each net type, thus the observed differences may have been a result of other factors present in each village.