RESUMO
In March 2020, the World Health Organization declared a global pandemic of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); epidemic conditions continue in nearly all countries today. Although the symptoms and imaging manifestations of COVID-19 predominantly involve the respiratory system, it is fundamental to know the manifestations of the disease and its possible complications in other organs to help in diagnosis and orient the prognosis. To improve the diagnostic process without increasing the risk of contagion unnecessarily, it is crucial to know when extrathoracic imaging tests are indicated and which tests are best in each situation. This paper aims to provide answers to these questions. To this end, we describe and illustrate the extrathoracic imaging manifestations of COVID-19 in adults as well as the entire spectrum of imaging findings in children.
RESUMO
Gene duplication and subsequent divergence can lead to the evolution of new functions and lineage-specific traits. In sticklebacks, the successive duplication of a mucin gene (MUC19) into a tandemly arrayed, multigene family has enabled the production of copious amounts of 'spiggin', a secreted adhesive protein essential for nest construction. Here, we examine divergence between spiggin genes among three-spined sticklebacks (Gasterosteus aculeatus) from ancestral marine and derived freshwater populations, and propose underpinning gene duplication mechanisms. Sanger sequencing revealed substantial diversity among spiggin transcripts, including alternatively spliced variants and interchromosomal spiggin chimeric genes. Comparative analysis of the sequenced transcripts and all other spiggin genes in the public domain support the presence of three main spiggin lineages (spiggin A, spiggin B and spiggin C) with further subdivisions within spiggin B (B1, B2) and spiggin C (C1, C2). Spiggin A had diverged least from the ancestral MUC19, while the spiggin C duplicates had diversified most substantially. In silico translations of the spiggin gene open reading frames predicted that spiggins A and B are secreted as long mucin-like polymers, while spiggins C1 and C2 are secreted as short monomers, with putative antimicrobial properties. We propose that diversification of duplicated spiggin genes has facilitated local adaptation of spiggin to a range of aquatic habitats.
Assuntos
Evolução Molecular , Proteínas de Peixes/genética , Duplicação Gênica , Smegmamorpha/genética , Processamento Alternativo , Animais , Clonagem Molecular , Masculino , Dados de Sequência Molecular , Família Multigênica , Fases de Leitura Aberta , Análise de Sequência de DNARESUMO
Behavioural ecologists have proposed various evolutionary mechanisms as to why different personality types coexist. Our ability to understand the evolutionary trajectories of personality traits requires insights from the quantitative genetics of behavioural reaction norms. We assayed > 1000 pedigreed stickleback for initial exploration behaviour of a novel environment, and subsequent changes in exploration over a few hours, representing their capacity to adjust their behaviour to changes in perceived novelty and risk. We found heritable variation in both the average level of exploration and behavioural plasticity, and population differences in the sign of the genetic correlation between these two reaction norm components. The phenotypic correlation was not a good indicator of the genetic correlation, implying that quantitative genetics are necessary to appropriately evaluate evolutionary hypotheses in cases such as these. Our findings therefore have important implications for future studies concerning the evolution of personality and plasticity.
Assuntos
Comportamento Animal/fisiologia , Ecossistema , Comportamento Exploratório/fisiologia , Personalidade/genética , Fenótipo , Smegmamorpha , Fatores Etários , Animais , Lagos , Observação , Personalidade/fisiologia , Análise de Regressão , Gravação em Vídeo , País de GalesRESUMO
Parasites can impact host reproduction by interfering with host endocrine systems, but the adaptive nature of such effects is disputed. Schistocephalus solidus plerocercoids are parasites of three-spined sticklebacks Gasterosteus aculeatus that are often associated with impaired host reproduction. Here, we relate reproductive behavior and physiology to levels of the androgen 11-ketotestosterone (11KT) in naturally infected and non-infected male sticklebacks from two UK populations. In one population infected males harbored heavy infections and showed uniformly reduced 11KT titres and kidney spiggin (nesting glue protein) content compared to non-infected fish. However in a second population infection levels were more variable and males with smaller infections recorded 11KT and spiggin titres that overlapped those of non-infected fish; among infected males from this population 11KT and kidney spiggin also both correlated negatively with infection severity. Male reproductive behavior correlated closely with 11KT titre in both populations, and infected males with high 11KT levels exhibited normal reproductive behavior. Our results suggest that Schistocephalus infection per se does not block reproductive development in male sticklebacks, and that some male fish may have the ability to breed whilst infected. Our results are not consistent with the hypothesis that Schistocephalus adaptively castrates male hosts via endocrine disruption; rather they support the hypothesis that reproductive disruption is a side effect of the energetic costs of infection.
Assuntos
Infecções por Cestoides/sangue , Infecções por Cestoides/fisiopatologia , Doenças dos Peixes/sangue , Reprodução/fisiologia , Smegmamorpha/fisiologia , Testosterona/análogos & derivados , Animais , Autopsia , Infecções por Cestoides/patologia , Infecções por Cestoides/veterinária , Doenças dos Peixes/metabolismo , Doenças dos Peixes/parasitologia , Doenças dos Peixes/patologia , Individualidade , Rim/metabolismo , Rim/patologia , Masculino , Variações Dependentes do Observador , Concentração Osmolar , Comportamento Sexual Animal/fisiologia , Smegmamorpha/sangue , Smegmamorpha/parasitologia , Testosterona/análise , Testosterona/sangue , Testosterona/metabolismo , TitulometriaRESUMO
In March 2020, the World Health Organization declared a global pandemic of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); epidemic conditions continue in nearly all countries today. Although the symptoms and imaging manifestations of COVID-19 predominantly involve the respiratory system, it is fundamental to know the manifestations of the disease and its possible complications in other organs to help in diagnosis and orient the prognosis. To improve the diagnostic process without increasing the risk of contagion unnecessarily, it is crucial to know when extrathoracic imaging tests are indicated and which tests are best in each situation. This paper aims to provide answers to these questions. To this end, we describe and illustrate the extrathoracic imaging manifestations of COVID-19 in adults as well as the entire spectrum of imaging findings in children.
Assuntos
COVID-19/diagnóstico por imagem , Adulto , COVID-19/complicações , Criança , Cardiopatias/virologia , Humanos , Doenças do Sistema Nervoso/virologia , Síndrome de Resposta Inflamatória Sistêmica , Trombose/virologiaRESUMO
A 'no-touch' hilum technique used to treat early portal vein complications post-liver transplantation in five children with body weight <10 kg is described. Four patients developed thrombosis and one portal flow absence secondary to collateral steal flow. A vascular sheath was placed through the previous laparotomy in the ileocolic vein (n = 2), inferior mesenteric vein (n = 1) or graft umbilical vein (n = 1). Portal clots were mechanically fragmented with balloon angioplasty. In addition, coil embolization of competitive collaterals (n = 3) and stent placement (n = 1) were performed. The catheter was left in place and exteriorized through the wound (n = 2) or a different transabdominal wall puncture (n = 3). A continuous transcatheter perfusion of heparin was subsequently administered. One patient developed recurrent thrombosis 24 h later which was resolved with the same technique. Catheters were removed surgically after a mean of 10.6 days. All patients presented portal vein patency at the end of follow-up. Three patients are alive after 5 months, 1.5 and 3.5 years, respectively; one patient required retransplantation 18 days postprocedure and the remaining patient died of adenovirus infection 2 months postprocedure. In conclusion, treatment of early portal vein complications following pediatric liver transplantation with this novel technique is feasible and effective.
Assuntos
Transplante de Fígado/efeitos adversos , Procedimentos Cirúrgicos Minimamente Invasivos , Veia Porta , Radiologia Intervencionista , Trombose Venosa/etiologia , Trombose Venosa/terapia , Infecções por Adenoviridae/etiologia , Infecções por Adenoviridae/mortalidade , Adolescente , Angiografia , Angioplastia com Balão , Criança , Estudos de Viabilidade , Feminino , Humanos , Masculino , Veia Porta/fisiopatologia , Cuidados Pós-Operatórios , Reoperação , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia Doppler , Grau de Desobstrução Vascular , Trombose Venosa/diagnósticoRESUMO
Plerocercoids of the pseudophyllidean cestode Schistocephalus solidus infect the three-spined stickleback Gasterosteus aculeatus, with important consequences for the biology of host fish. Techniques for culturing the parasite in vitro and generating infective stages that can be used to infect sticklebacks experimentally have been developed, and the system is increasingly used as a laboratory model for investigating aspects of host-parasite interactions. Recent experimental laboratory studies have focused on the immune responses of hosts to infection, the consequences of infection for the growth and reproductive development of host fish and the effects of infection on host behaviour. Here we introduce the host and the parasite, review the major findings of these recent experimental infection studies and identify further aspects of host parasite interactions that might be investigated using the system.
Assuntos
Cestoides/fisiologia , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Smegmamorpha/parasitologia , Animais , Infecções por Cestoides/parasitologia , Interações Hospedeiro-Parasita , Estágios do Ciclo de VidaRESUMO
INTRODUCTION: Treatment with neuroleptics may be associated with secondary sexual dysfunction. Studies of sexual dysfunction induced by antipsychotic are important to establish the effectiveness of these agents in patients taking chronic treatments. The main objective of this study was to evaluate prospectively whether a 3 month course ofaripiprazole produces changes in the sexual function of patients with schizophrenia. METHODS: The efficacy analysis was performed in the intention-to-treat population (41 patients) and the per protocol population (36 patients). The safety analysis was based on the total sample (42 patients). RESULTS: The incidence of sexual dysfunction after 3 months of treatment with aripiprazole was zero both in patients who switched therapy due to lack of efficacy and in those taking aripiprazole as a first antipsychotic. Aripiprazole led to an improvement in the symptoms of psychosis (score on the BPRS) and lower scores on the SALSEX questionnaire.The most remarkable improvement was in delayed eyaculation/orgasm. CONCLUSION: During the 3 months of treatment, we observed an overall improvement in sexual performance, with a quicker recovery in men than in women, although recovery was similar in both at the end of treatment.
Assuntos
Antipsicóticos/uso terapêutico , Piperazinas/uso terapêutico , Quinolonas/uso terapêutico , Disfunções Sexuais Fisiológicas/prevenção & controle , Adolescente , Adulto , Aripiprazol , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Esquizofrenia/tratamento farmacológico , Disfunções Sexuais Fisiológicas/induzido quimicamente , Fatores de Tempo , Adulto JovemRESUMO
Umbilical cord amniotic bands occur in approximately 10% of cases of amniotic band syndrome and are a well-known cause of fetal death. An unexpected amniotic band encircling the umbilical cord was diagnosed during a fetoscopic procedure to release a leg constriction. Both bands were released fetoscopically using a YAG laser. We report the first case of an amniotic band involving the umbilical cord diagnosed and released prenatally.
Assuntos
Síndrome de Bandas Amnióticas/cirurgia , Fetoscopia/métodos , Terapia a Laser/métodos , Cordão Umbilical , Adulto , Síndrome de Bandas Amnióticas/complicações , Síndrome de Bandas Amnióticas/diagnóstico , Feminino , Humanos , Recém-Nascido , Lasers de Estado Sólido , Salvamento de Membro/métodos , Gravidez , Fluxo Sanguíneo Regional , Resultado do Tratamento , Ultrassonografia , Cordão Umbilical/diagnóstico por imagem , Cordão Umbilical/patologiaRESUMO
Two-spotted goby Gobiusculus flavescens from the Swedish Gullmarsfjord regularly present subcutaneous creamy-white patches in the body musculature, associated with Kabatana sp. infection. Analysis of the 16S rRNA gene of the microsporidium showed 98.54% homology with Kabatana newberryi infecting a marine goby from California, indicating that the Swedish microsporidium is either a different strain of K. newberryi or a closely related species. This represents the first record of a Kabatana species in the Atlantic Ocean. The genetic similarity of the 2 microsporidia was paralleled by close infection phenotypes. Infected muscle fibres were swollen compared to adjacent non-infected fibres, and mature spore masses were found throughout the skeletal musculature. No xenoma formation was detected. Since G. flavescens is an established model species in behavioural ecology, the host-parasite system is ideally suited for testing how microsporidian infections affect host behaviour and fitness.
Assuntos
Doenças dos Peixes/parasitologia , Microsporídios não Classificados/isolamento & purificação , Microsporidiose/veterinária , Perciformes , Animais , Oceano Atlântico , Doenças dos Peixes/epidemiologia , Masculino , Microsporídios não Classificados/classificação , Microsporídios não Classificados/genética , Microsporidiose/epidemiologia , Músculo Esquelético/parasitologia , Músculo Esquelético/patologia , Filogenia , EsporosRESUMO
Male three-spined stickleback Gasterosteus aculeatus from two U.K. populations with endemic infections of the cestode Schistocephalus solidus were brought into the laboratory prior to the breeding season and transferred to nesting tanks under conditions designed to stimulate sexual maturation. Nesting and courtship behaviours were scored over a 35 day period, after which fish were euthanized and the liver, spleen, kidney and gonads were weighed. Among G. aculeatus from a park pond in Leicester, U.K., infected males rarely engaged in reproductive behaviours and exhibited reduced indices of sexual development, body condition and general health, with effects being largely independent of relative parasite mass (parasite index, I(P)). In contrast, the reproductive behaviour of infected fish from Kendoon Loch in Dumfriesshire, U.K. appeared to be less severely affected, with infected fish regularly building nests and courting females under laboratory conditions. This was paralleled by a more limited effect of infection on physiological indicators of development, condition and general health. Furthermore, behavioural and physiological variables typically correlated with I(P) among infected fish from this population. Although comparing the performance of infected fish from the two populations directly was difficult due to potentially confounding factors, the results support the findings of recent studies showing that the effects of S. solidus on host reproduction are unlikely to be uniform across G. aculeatus populations. One possibility is that variation in the effects of infection arises from differences in the co-evolutionary association times of G. aculeatus with the parasite.
Assuntos
Infecções por Cestoides/veterinária , Doenças dos Peixes/fisiopatologia , Interações Hospedeiro-Parasita/fisiologia , Reprodução/fisiologia , Smegmamorpha/fisiologia , Smegmamorpha/parasitologia , Animais , Constituição Corporal/fisiologia , Cestoides/fisiologia , Infecções por Cestoides/fisiopatologia , Feminino , Masculino , Comportamento Sexual Animal/fisiologia , Maturidade Sexual/fisiologia , Smegmamorpha/crescimento & desenvolvimento , Reino UnidoRESUMO
In this study, we recovered Schistocephalus solidus plerocercoids from singly and multiply infected three-spine sticklebacks, Gasterosteus aculeatus, transferred them individually to in vitro culture conditions, and quantified their lifetime egg output. We found a significant difference in the relationships between plerocercoid mass and lifetime egg output for parasites recovered from singly and multiply infected sticklebacks. Although egg output was strongly and positively related to plerocercoid mass amongst worms from singly infected fish, for those recovered from multiply infected sticklebacks the relationship was marginally nonsignificant and negative, with small worms achieving high levels of egg production. We suggest 2 hypotheses that may explain differences in the egg production of plerocercoids from singly and multiply infected fish. One possibility is that smaller plerocercoids in asymmetric multiple infections develop precocially, in response to host manipulation strategies of larger worms that decrease survival prospects of the host. Alternatively, small worms in singly infected sticklebacks may be prevented from becoming sexually mature because they face energetic constraints associated with having to overcome the host's immune response alone. We discuss our results in terms of recent studies examining strategic egg production in helminths.
Assuntos
Cestoides/fisiologia , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Smegmamorpha/parasitologia , Animais , Infecções por Cestoides/parasitologia , Oviposição/fisiologiaRESUMO
It is well established that parasites can have profound effects on the behaviour of host organisms, and that individual differences in behaviour can influence susceptibility to parasite infections. Recently, two major themes of research have developed. First, there has been a growing interest in the proximate, mechanistic processes underpinning parasite-associated behaviour change, and the interactive roles of the neuro-, immune, and other physiological systems in determining relationships between behaviour and infection susceptibility. Secondly, as the study of behaviour has shifted away from one-off measurements of single behaviours and towards a behavioural syndromes/personality framework, research is starting to focus on the consequences of parasite infection for temporal and contextual consistency of behaviour, and on the implications of different personality types for infection susceptibility. In addition, there is increasing interest in the potential for relationships between cognition and personality to also have implications for host-parasite interactions. As models well-suited to both the laboratory study of behaviour and experimental parasitology, teleost fish have been used as hosts in many of these studies. In this review we provide a broad overview of the range of mechanisms that potentially generate links between fish behaviour, personality, and parasitism, and illustrate these using examples drawn from the recent literature. In addition, we examine the potential interactions between cognition, personality and parasitism, and identify questions that may be usefully investigated with fish models.
Assuntos
Cognição/fisiologia , Peixes/fisiologia , Peixes/parasitologia , Interações Hospedeiro-Parasita , Personalidade/fisiologia , Simbiose/fisiologia , AnimaisRESUMO
The three-spined stickleback is a ubiquitous fish of marine, brackish and freshwater ecosystems across the Northern hemisphere that presents intermediate sensitivity to copper. Male sticklebacks display a range of elaborate reproductive behaviours that include nest construction. To build the nests, each male binds nesting material together using an endogenous glycoprotein nesting glue, known as 'spiggin'. Spiggin is a cysteine-rich protein and, therefore, potentially binds heavy metals present in the environment. The aim of this study was to investigate the capacity of stickleback nests to accumulate copper from environmental sources. Newly built nests, constructed by male fish from polyester threads in laboratory aquaria, were immersed in copper solutions ranging in concentration from 21.1-626.6 µg Cu L(-1). Bundles of polyester threads from aquaria without male fish were also immersed in the same copper solutions. After immersion, nests presented higher amounts of copper than the thread bundles, indicating a higher capacity of nests to bind this metal. A significant, positive correlation between the concentration of copper in the exposure solution and in the exposed nests was identified, but there was no such relationship for thread bundles. Since both spiggin synthesis and male courtship behaviour are under the control of circulating androgens, we predicted that males with high courtship scores would produce and secrete high levels of the spiggin protein. In the present study, nests built by high courtship score males accumulated more copper than those built by low courtship score males. Considering the potential of spiggin to bind metals, the positive relationship between fish courtship and spiggin secretion seems to explain the higher amount of copper on the nests from the fish showing high behaviour scores. Further work is now needed to determine the consequences of the copper binding potential of spiggin in stickleback nests for the health and survival of developing embryos.
Assuntos
Cobre , Exposição Ambiental/análise , Proteínas de Peixes , Smegmamorpha/metabolismo , Poluentes Químicos da Água , Animais , Cobre/análise , Cobre/metabolismo , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Masculino , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismoRESUMO
Parasites impose an energetic cost upon their hosts, yet, paradoxically instances have been reported in which infection is associated with enhanced, rather than diminished, host growth rates. Field studies of these parasite effects are problematic, since the pre-infection condition of the hosts is generally unknown. Here, we describe a laboratory experiment in which the growth rate and body condition of 76 laboratory-reared three-spined stickleback fishes were examined before, during and after each fish was fed the infective stage of the parasitic cestode Schistocephalus solidus. Twenty-one of these fishes went on to become infected by the cestode. Fishes were individually housed and provided with an abundant food supply to eliminate the potentially masking effects of variable competitive ability. Infection occurred independently of fish gender, size, body condition or pre-exposure growth rate. After exposure to the cestode, infected fishes grew faster (excluding parasite weight) and maintained a similar or better body condition compared with uninfected fishes, despite developing enlarged spleens. The accelerated growth could not be explained by reduced gonadal development. This result, one of few demonstrations of parasite-associated growth enhancement in fishes, is discussed with respect to other such parasite systems.
Assuntos
Cestoides/patogenicidade , Peixes/crescimento & desenvolvimento , Peixes/parasitologia , Animais , Peso Corporal , Feminino , Doenças dos Peixes/parasitologia , Doenças dos Peixes/patologia , Gônadas/crescimento & desenvolvimento , Interações Hospedeiro-Parasita , Masculino , Tamanho do ÓrgãoRESUMO
'Good genes' models of sexual selection suggest that elaborate male sexual ornaments have evolved as reliable signals of male quality because only males of high genetic viability are able to develop and maintain them. Females benefit from choosing such individuals if quality is heritable. A key prediction is that the offspring of males with elaborate mating displays will perform better than those of less elaborate males, but it has proved difficult to demonstrate such an effect independently of the effects of differences in parental investment. We tested for 'good genes' linked to male ornamentation in the three-spined stickleback Gasterosteus aculeatus using in vitro fertilization to generate maternal half-siblings, which were raised without parental care. Maternal half-siblings sired by brightly coloured males grew less quickly than half-siblings sired by dull males but were more resistant to a controlled disease challenge. Among the offspring that became infected, those with brighter fathers had higher white blood cell counts. This suggests that highly ornamented males confer disease resistance on their offspring. The association with reduced growth suggests a mechanism for the maintenance of heritable variation in both disease resistance and male sexual coloration.
Assuntos
Infecções por Cestoides/veterinária , Doenças dos Peixes/imunologia , Caracteres Sexuais , Comportamento Sexual Animal , Smegmamorpha , Animais , Cestoides/patogenicidade , Infecções por Cestoides/imunologia , Comportamento de Escolha , Cor , Feminino , Doenças dos Peixes/parasitologia , Masculino , Reprodução , Smegmamorpha/genética , Smegmamorpha/crescimento & desenvolvimento , Smegmamorpha/parasitologia , Smegmamorpha/fisiologiaRESUMO
Quantitative data are presented on the spatial distribution of metacercariae of the digenean trematode Diplostomum phoxini (Faust, 1918) in the brains of minnows, Phoxinus phoxinus (Linnaeus, 1758), from two Scottish populations. Sequential examination of serial histological sections revealed metacercariae to be unevenly distributed throughout the brain, aggregating in specific regions including the cerebellum, the medulla oblongata and the optic lobes. In addition, a number of metacercariae were found in the anterior part of the spinal cord. The inferior lobe of the cerebellum, pituitary, olfactory lobes and olfactory bulbs were largely free of metacercariae. Reasons for the uneven distribution of metacercariae within the brains of infected minnows are discussed, including the possibility that the parasite may have evolved to enhance its transmission to subsequent hosts by aggregating in regions known to be important in the control of the host's antipredator responses.
Assuntos
Encefalopatias/veterinária , Cyprinidae/parasitologia , Doenças dos Peixes/parasitologia , Infecções por Trematódeos/veterinária , Animais , Encéfalo/anatomia & histologia , Encefalopatias/parasitologia , Doenças do Sistema Nervoso Central/parasitologia , Doenças do Sistema Nervoso Central/veterinária , Cyprinidae/anatomia & histologia , Escócia , Distribuição TecidualRESUMO
PURPOSE: To evaluate the impact of the "Spanish Consensus on Physical Health in Patients with Schizophrenia" on psychiatrists' evaluations of the physical health of patients with schizophrenia. METHOD: Epidemiological, non-interventional, national, multicentre study, with two retrospective, cross-sectional data collection stages in which 229 psychiatrists evaluated 1193 clinical records of patients with schizophrenia (ICD-10) seen in January and September of 2007. RESULTS: Mean age of the patients was 39.7±11.6 years, 65.5% were men, diagnosed for schizophrenia 14.0±10.3 years ago. Forty percent of the patients suffer from a concomitant disease, the most prevalent being hypercholesterolemia (46.3%), hypertriglyceridaemia (33.5%) and arterial hypertension (26.0%). The difference in the number of patients who had all the physical measurements taken between the two cross-sectional evaluations was 13.8% (CI: 11.8%, 15.7%). The differences for each parameter were: weight 13.7% (CI: 11.7%, 15.6%), BMI 13.58% (CI: 11.6%, 15.5%), waist circumference 14.0% (CI: 12.0%, 15.39%), lipid profile 2.9% (CI: 1.9%, 3.9%) and glycaemia 2.6% (CI: 1.7%, 3.5%). CONCLUSIONS: These results imply that the dissemination of the "Consensus on Physical Health in Schizophrenia Patients", and possibly other actions, has made psychiatrists more aware of an integral approach to patients with schizophrenia, promoting increased monitoring of the physical health of these patients.
Assuntos
Atitude do Pessoal de Saúde , Conferências de Consenso como Assunto , Saúde , Esquizofrenia/complicações , Adulto , Estudos Transversais , Atenção à Saúde , Feminino , Humanos , Hipercolesterolemia/complicações , Hipertensão/complicações , Hipertrigliceridemia/complicações , Masculino , Pessoa de Meia-IdadeRESUMO
Data are presented on the infection dynamics of the brain-dwelling metacercariae of Diplostomum phoxini (Digenea: Trematoda) parasitizing European minnow (Phoxinus phoxinus) populations in a lowland river (River Endrick) and a highland loch (Loch Maragan) in central Scotland. Prevalence of the parasite approached 100% in all samples taken from both populations over a 12-month period, and within each population the intensity of infection increased with increasing host fork length. However, the two relationships differed, and size-matched minnows from the Endrick exhibited significantly higher intensities than those from Loch Maragan, suggesting that metacercarial acquisition occurred at different rates in the two populations. Data regarding seasonal trends in the acquisition of D. phoxini indicated that fish in both populations become infected with the parasites mainly during the spring and summer, with negligible infection occurring during winter months. Analysis of size-matched fish from individual samples revealed apparent differences in the distribution of D. phoxini within the two host populations. Whereas D. phoxini metacercariae appeared to be overdispersed amongst length-matched fish from Loch Maragan samples, the parasite was distributed normally amongst fish from the Endrick. Possible reasons for the observed differences in the infection characteristics of D. phoxini in the two minnow populations are discussed, with reference to the parasite's transmission dynamics and local environmental conditions.