RESUMO
Finding effective ways of conserving large carnivores is widely recognised as a priority in conservation. However, there is disagreement about the most effective way to do this, with some favouring top-down 'command and control' approaches and others favouring collaboration. Arguments for coercive top-down approaches have been presented elsewhere; here we present arguments for collaboration. In many parts of the developed world, flexibility of approach is built into the legislation, so that conservation objectives are balanced with other legitimate goals. In the developing world, limited resources, poverty and weak governance mean that collaborative approaches are likely to play a particularly important part in carnivore conservation. In general, coercive policies may lead to the deterioration of political legitimacy and potentially to non-compliance issues such as illegal killing, whereas collaborative approaches may lead to psychological ownership, enhanced trust, learning, and better social outcomes. Sustainable hunting/trapping plays a crucial part in the conservation and management of many large carnivores. There are many different models for how to conserve carnivores effectively across the world, research is now required to reduce uncertainty and examine the effectiveness of these approaches in different contexts.
Assuntos
Carnívoros , Conservação dos Recursos Naturais/legislação & jurisprudência , Conservação dos Recursos Naturais/métodos , Distribuição Animal , Animais , Humanos , Modelos BiológicosRESUMO
The ecosystem approach--as endorsed by the Convention on Biological Diversity (CDB) in 2000-is a strategy for holistic, sustainable, and equitable natural resource management, to be implemented via the 12 Malawi Principles. These principles describe the need to manage nature in terms of dynamic ecosystems, while fully engaging with local peoples. It is an ambitious concept. Today, the term is common throughout the research and policy literature on environmental management. However, multiple meanings have been attached to the term, resulting in confusion. We reviewed references to the ecosystem approach from 1957 to 2012 and identified 3 primary uses: as an alternative to ecosystem management or ecosystem-based management; in reference to an integrated and equitable approach to resource management as per the CBD; and as a term signifying a focus on understanding and valuing ecosystem services. Although uses of this term and its variants may overlap in meaning, typically, they do not entirely reflect the ethos of the ecosystem approach as defined by the CBD. For example, there is presently an increasing emphasis on ecosystem services, but focusing on these alone does not promote decentralization of management or use of all forms of knowledge, both of which are integral to the CBD's concept. We highlight that the Malawi Principles are at risk of being forgotten. To better understand these principles, more effort to implement them is required. Such efforts should be evaluated, ideally with comparative approaches, before allowing the CBD's concept of holistic and socially engaged management to be abandoned or superseded. It is possible that attempts to implement all 12 principles together will face many challenges, but they may also offer a unique way to promote holistic and equitable governance of natural resources. Therefore, we believe that the CBD's concept of the ecosystem approach demands more attention.
Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Terminologia como AssuntoRESUMO
Many vector-borne pathogens whose primary vectors are generalists, such as Ixodid ticks, can infect a wide range of host species and are often zoonotic. Understanding their transmission dynamics is important for the development of disease management programmes. Models exist to describe the transmission dynamics of such diseases, but are necessarily simplistic and generally limited by knowledge of vector population dynamics. They are typically deterministic SIR-type models, which predict disease dynamics in a single, non-spatial, closed patch. Here we explore the limitations of such a model of louping-ill virus dynamics by challenging it with novel field data. The model was only partially successful in predicting Ixodes ricinus density and louping-ill virus prevalence at 6 Scottish sites. We extend the existing multi-host model by forming a two-patch model, incorporating the impact of roaming hosts. This demonstrates that host movement may account for some of the discrepancies between the original model and empirical data. We conclude that insights into the dynamics of multi-host vector-borne pathogens can be gained by using a simple two-patch model. Potential improvements to the model, incorporating aspects of spatial and temporal heterogeneity, are outlined.
Assuntos
Vetores Aracnídeos/virologia , Cervos/fisiologia , Vírus da Encefalite Transmitidos por Carrapatos/fisiologia , Encefalite Transmitida por Carrapatos/transmissão , Galliformes/virologia , Interações Hospedeiro-Patógeno , Ixodes/virologia , Animais , Doenças das Aves/virologia , Cervos/parasitologia , Cervos/virologia , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/virologia , Modelos Biológicos , Movimento , Dinâmica Populacional , Prevalência , Escócia/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
SUMMARY: Macroparasites potentially play a significant but often ignored role in the ecology and dynamics of wild ruminant populations. In the Arctic, parasites may impact on host populations by exacerbating the effects of seasonal and limited forage availability on the condition, fecundity and survival of individuals. We studied the effects of abomasal nematode parasites and warble flies, Hypoderma tarandi, on condition and pregnancy of caribou Rangifer tarandus in the Dolphin-Union herd, Nunavut, Canada. By the end of winter, female caribou over 2 years old showed a significant decrease in body weight with increasing nematode burden, and a decrease in back fat depth with increasing warble abundance. These effects were exaggerated in the non-pregnant fraction of the population. High warble larvae burdens were also associated with significantly reduced probability of being pregnant. Our research demonstrates a negative relationship between parasites and caribou condition that may have consequences for their fitness. Additionally, we discuss the possibility that muskox Ovibos moschatus share some parasite species with the caribou and could lead to elevated burdens in the sympatric host. Parasites may have been a contributory factor in a previous winter range-shift of the caribou herd and this may reflect a form of apparent competition between the two ungulate species.
Assuntos
Dípteros , Miíase/veterinária , Nematoides , Infecções por Nematoides/veterinária , Rena/parasitologia , Abomaso/parasitologia , Animais , Distribuição da Gordura Corporal , Feminino , Masculino , Miíase/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/parasitologia , Gravidez , Rena/crescimento & desenvolvimento , Rena/fisiologia , Ruminantes/parasitologia , Estações do Ano , Redução de Peso/fisiologiaAssuntos
Vetores Aracnídeos/virologia , Doenças das Aves/epidemiologia , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/veterinária , Ixodes/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , Anticorpos Antivirais/sangue , Doenças das Aves/mortalidade , Doenças das Aves/transmissão , Aves , Encefalite Transmitida por Carrapatos/epidemiologia , Encefalite Transmitida por Carrapatos/mortalidade , Prevalência , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Especificidade da Espécie , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/transmissão , Infestações por Carrapato/veterináriaRESUMO
We have recently demonstrated that co-administration of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") with the reversible monoamine oxidase type A (MAO-A) inhibitor moclobemide at an ambient temperature of 22 degrees C significantly increases striatal 5-HT outflow and 5-HT-mediated behaviors. In the present study, using microdialysis, we examined the effects of co-administration of MDMA or para-methoxyamphetamine (PMA) with moclobemide on striatal 5-HT outflow at the elevated ambient temperatures of 30 degrees C. Samples were collected every 30 min for 4 h and analyzed by high-performance liquid chromatography assay with electrochemical detection (HPLC-ED). 5-HT-mediated effects on body temperature and behavior were also recorded. Rats were treated with either saline or 20 mg/kg (i.p.) moclobemide, followed by 10 mg/kg (i.p.) MDMA, 10 mg/kg (i.p.) PMA or saline 60 min later. Both MDMA and PMA produced significant increases in 5-HT outflow (370% peak and 309% peak, respectively, P<0.05). MDMA and PMA significantly increased body temperature (+2.0 degrees C and +2.1 degrees C, respectively, P<0.01) and drug-related behaviors (P<0.05). When MDMA or PMA was co-administered with moclobemide, additional significant increases were seen in 5-HT outflow (850% peak, P<0.01 and 1450% peak, P<0.001, respectively) and only MDMA showed additional significant increase in body temperature (+5.0 degrees C, P<0.001). No additional increases were seen in behavioral activity. When moclobemide was co-administered with MDMA, sustained increases in body temperature were recorded that were significantly higher than with MDMA alone and such increases were not observed in our previous study at normal room temperature. Our results suggest greater risk of MDMA-induced adverse effects on body temperature regulation, compared with PMA, when used in combination with moclobemide at elevated ambient temperatures.
Assuntos
Anfetaminas/administração & dosagem , Comportamento Animal/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Corpo Estriado/efeitos dos fármacos , Moclobemida/administração & dosagem , Inibidores da Monoaminoxidase/administração & dosagem , Serotonina/metabolismo , Análise de Variância , Animais , Área Sob a Curva , Cromatografia Líquida de Alta Pressão/métodos , Combinação de Medicamentos , Alucinógenos/administração & dosagem , Ácido Hidroxi-Indolacético/metabolismo , Masculino , N-Metil-3,4-Metilenodioxianfetamina/administração & dosagem , Ratos , Ratos Sprague-Dawley , Temperatura , Fatores de TempoRESUMO
Regulation of ungulate populations by parasites relies on establishing a density-dependent relationship between infection and vital demographic rates which may act through the effect of parasites on body condition. We examine evidence for parasite impacts in 285 red deer (Cervus elaphus) harvested during 1991 and 1992 on the Isle of Rum. In the abomasa, prevalence of nematodes was 100% and the most abundant genus observed were Ostertagia species, however, mean intensity of infection was low (less than 1000) relative to other studies. Additional species, also present in low numbers, included Nematodirus spp., Capillaria spp., Cooperia spp., Monieza expanza, Oesophagostomum venulosum and Trichuris ovis. Lungworm (Dictyocaulus spp.) and tissue worm (Elaphostronygylus cervi) larvae were also observed in faecal samples. There was no evidence for acquired immunity to abomasal nematodes. Despite low levels of infection, both adult male and female deer showed significant negative correlation between indices of condition (kidney fat index, dressed carcass weight and larder weight) and intensity of Ostertagia spp. infection. However, there was no evidence that pregnancy rate in females was related to intensity of infection. For calves, there was no relationship between body condition and intensity of infection. The apparent subclinical effects of low-level parasite infection on red deer performance could alternatively be due to animals in poorer nutritional state being more susceptible to infection. Either way the results suggest that further studies of wild populations are justified, in particular where high local host densities exist or alternative ungulate hosts are present, and, where experimental treatments are tractable.
Assuntos
Cervos/parasitologia , Nível de Saúde , Infecções por Nematoides/veterinária , Ostertagíase/veterinária , Complicações Parasitárias na Gravidez/veterinária , Abomaso/parasitologia , Fatores Etários , Animais , Animais Recém-Nascidos/parasitologia , Animais Selvagens/parasitologia , Constituição Corporal , Peso Corporal , Efeitos Psicossociais da Doença , Cervos/fisiologia , Fezes/parasitologia , Feminino , Masculino , Infecções por Nematoides/complicações , Infecções por Nematoides/parasitologia , Ostertagia/isolamento & purificação , Ostertagíase/complicações , Ostertagíase/parasitologia , Gravidez , Taxa de Gravidez , Fatores SexuaisRESUMO
Estimates of the intensity and abundance of species provide essential data for ecological, evolutionary and epidemiological studies of gastrointestinal nematode communities. These estimates are typically derived from the species composition of adult males when only males have readily scorable species-specific morphological traits. Such estimation assumes that all species in the community have the same adult sex ratio. We evaluated this assumption for the trichostrongyle nematodes Ostertagia gruehneri and Marshallagia marshalli in infracommunities in Svalbard reindeer by identifying to species adult females using a polymerase chain reaction assay. The proportion of males was found to be slightly higher in O. gruehneri than in M. marshalli. Evidence for seasonal variation and density dependence in the adult sex ratio was only found for O. gruehneri. Possible demographic mechanisms for such sex ratio variation are discussed, and stochastic models that generate density-dependent sex ratios proposed. Sex ratio variation caused substantial bias in some male-based estimates of intensity of infection, while substantial and consistent bias in estimates of abundances was only evident in late winter samples. Our results suggest that estimating sex ratios can be particularly important in individual host level studies of nematode species of low abundance.
Assuntos
Gastroenteropatias/veterinária , Nematoides/fisiologia , Infecções por Nematoides/veterinária , Rena/parasitologia , Animais , Feminino , Gastroenteropatias/parasitologia , Masculino , Infecções por Nematoides/parasitologia , Estações do Ano , Razão de MasculinidadeRESUMO
Mainland populations of Arctic reindeer and caribou Rangifer tarandus often undergo extensive movements, whereas populations on islands tend to be isolated and sedentary. To characterize the genetic consequences of this difference, levels of genetic diversity and subdivision of Svalbard reindeer (R. t. platyrhynchus) from two adjacent areas on Nordenskjiöldland, Spitsbergen were estimated using data from up to 14 microsatellites. The mean number of alleles per locus in Svalbard reindeer was 2.4 and mean expected heterozygosity per locus was 0.36. The latter value was significantly lower than in Canadian caribou and Norwegian reindeer but higher than in some other cervid species. Large samples of females (n = 743) and small samples of males (n = 38) from two sites approximately 45 km apart showed genetic subdivision, which could be due to local population fluctuations or limited gene flow. To our knowledge, this is the first study to report significant differentiation at microsatellite loci in Rangifer at such short geographical distances. Neither population showed genetic evidence for recent population bottlenecks when loci unbiased with respect to heterozygosity were analysed. In contrast, false signals of a recent bottleneck were detected when loci upwardly biased with respect to heterozygosity were analysed. Thus, Svalbard reindeer appeared to conform to the paradigm of island populations made genetically depauperate by genetic drift.
Assuntos
DNA/análise , Deriva Genética , Variação Genética , Repetições de Microssatélites/genética , Rena/genética , Alelos , Animais , Feminino , Frequência do Gene , Genética Populacional , Heterozigoto , Masculino , Dinâmica Populacional , SvalbardRESUMO
Methods for estimating abundance of arrested gastrointestinal larvae in large mammal hosts by digestion of the gastrointestinal mucosa are well established. The effects of digestion on the success of species identification using the polymerase chain reaction (PCR) are, however, unknown. In this study, the relationship between numerical recovery of arrested larvae and the success of PCR-typing for the second internal transcribed spacer of ribosomal genes was characterized. Fresh and prefrozen mucosa of 4 sheep yielded very similar rates of recovery and PCR detection. When sheep mucosa were digested with neutral N-acetyl cysteine, recovery increased, whereas PCR detection remained constant (60-80%) with digest duration (1-16 hr). In contrast, when sheep and Svalbard reindeer mucosa were digested with acid-pepsin, recovery increased, whereas PCR detection declined to 0 with digest duration. Thus, to optimize recovery and PCR analysis of arrested gastrointestinal nematode larvae, acid-pepsin digestion of 1-2 hr for PCR detection and 16 hr for recovery, or neutral N-acetyl cysteine digestion of 8-16 hr for both assays, should be used.
Assuntos
DNA Espaçador Ribossômico/análise , Cervos/parasitologia , Nematoides/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Ovinos/parasitologia , Acetilcisteína , Animais , DNA de Helmintos/análise , Ácido Clorídrico , Larva , Nematoides/genética , Pepsina A , Fatores de TempoRESUMO
Even though theoretical models show that parasites may regulate host population densities, few empirical studies have given support to this hypothesis. We present experimental and observational evidence for a host-parasite interaction where the parasite has sufficient impact on host population dynamics for regulation to occur. During a six year study of the Svalbard reindeer and its parasitic gastrointestinal nematode Ostertagia gruehneri we found that anthelminthic treatment in April-May increased the probability of a reindeer having a calf in the next year, compared with untreated controls. However, treatment did not influence the over-winter survival of the reindeer. The annual variation in the degree to which parasites depressed fecundity was positively related to the abundance of O. gruehneri infection the previous October, which in turn was related to host density two years earlier. In addition to the treatment effect, there was a strong negative effect of winter precipitation on the probability of female reindeer having a calf. A simple matrix model was parameterized using estimates from our experimental and observational data. This model shows that the parasite-mediated effect on fecundity was sufficient to regulate reindeer densities around observed host densities.
Assuntos
Ostertagia/fisiologia , Rena/fisiologia , Rena/parasitologia , Reprodução , Doenças dos Animais/tratamento farmacológico , Doenças dos Animais/parasitologia , Animais , Anti-Helmínticos/uso terapêutico , Fertilidade , Interações Hospedeiro-Parasita , Ostertagia/efeitos dos fármacos , Ostertagia/isolamento & purificação , Ostertagíase/tratamento farmacológico , Ostertagíase/parasitologia , Ostertagíase/veterinária , Densidade Demográfica , Estações do Ano , Processos Estocásticos , Taxa de Sobrevida , Fatores de Tempo , Tempo (Meteorologia)RESUMO
The gastrointestinal nematode Ostertagia gruehneri is a parasite of reindeer that can have a significant impact on host population dynamics. To gain a better understanding of the population dynamics of O. gruehneri, we parameterise a model for its fecundity that describes the observed seasonal and intensity dependent pattern of faecal egg counts well. The faecal egg count model is combined with a model for the seasonal faecal production rate of Svalbard reindeer to obtain quantitative estimates of the fecundity of O. gruehneri. The model is used to evaluate the relative contribution to pasture contamination of variation in the abundance of O. gruehneri and variation in reindeer densities. It is concluded that due to the intensity dependence in nematode fecundity, variation in reindeer population densities is likely to be the most important of these factors for pasture contamination.
Assuntos
Ostertagia/fisiologia , Ostertagíase/parasitologia , Ostertagíase/veterinária , Rena/parasitologia , Animais , Fezes/parasitologia , Feminino , Fertilidade/fisiologia , Interações Hospedeiro-Parasita , Masculino , Modelos Biológicos , Contagem de Ovos de Parasitas/veterinária , Dinâmica Populacional , Fatores de TempoRESUMO
The gastro-intestinal parasitic nematodes of ruminants Marshallagia marshalli and M. occidentalis are morphs of a single species according to indirect evidence. In this study, their taxonomic status and molecular identification were assessed more directly in isolates from the abomasal nematode community of Svalbard reindeer using genetic data. DNA sequences of the first and second internal transcribed spacers of nuclear ribosomal RNA genes were obtained from individual nematodes by the polymerase chain reaction (PCR). Both taxa contained virtually identical sequences of each ITS and shared most of the polymorphisms detected. A PCR assay based on ITS-2 sequences previously developed to identify M. marshalli and Ostertagia gruehneri, the second common species in this community, gave identical results for M. marshalli and M. occidentalis. Genetic data thus confirmed that M. marshalli and M. occidentalis are conspecific.
Assuntos
DNA de Helmintos/genética , Nematoides/classificação , Rena/parasitologia , Abomaso/parasitologia , Animais , Sequência de Bases , DNA de Helmintos/química , DNA de Helmintos/isolamento & purificação , DNA Espaçador Ribossômico/genética , Masculino , Dados de Sequência Molecular , Nematoides/genética , Noruega , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
The role of metabolic polymorphism in the development of physical dependence to codeine was assessed in cytochrome P450 2D2 (CYP2D2) deficient Dark Agouti and CYP2D2 intact Sprague-Dawley rats by assessment of the severity of naloxone precipitated withdrawal after codeine and morphine administration. Plasma morphine concentrations after codeine were significantly higher (P<0.01) in Sprague-Dawley than in Dark Agouti rats with metabolic ratios of 0.71 +/- 0.27 and 0.07 +/- 0.04, respectively. Withdrawal after codeine resulted in significantly greater hypothermia (3.5-4 degrees C, P<0.0001) in Sprague-Dawley animals compared to the other groups. Body weight loss was similar for all groups ranging from 6.2 +/- 0.4 to 8.2 +/- 0.6 g. When strain and treatment data were combined, a relationship between body temperature and plasma morphine concentration could be described by the inverse Hill equation (r(2)=0.76, EC(50)=556 +/- 121 ng/ml, n=2.9 +/- 1.5). These data indicate that dependence and withdrawal after codeine administration are dependent on its bioconversion to morphine.
Assuntos
Analgésicos Opioides/farmacologia , Hidrocarboneto de Aril Hidroxilases , Codeína/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Síndrome de Abstinência a Substâncias , Analgésicos Opioides/farmacocinética , Animais , Temperatura Corporal , Peso Corporal , Codeína/sangue , Codeína/farmacocinética , Sistema Enzimático do Citocromo P-450/deficiência , Feminino , Genótipo , Morfina/sangue , Morfina/farmacologia , Naloxona/administração & dosagem , Ratos , Ratos Sprague-DawleyRESUMO
Stability of trichostrogylid populations indicates that some form of density-dependent regulation occurs which could act through fecundity. We present evidence for intraspecific density-dependent effects in 1 of 2, dominant, abomasal nematodes species (Ostertagia gruehneri) of Svalbard reindeer (Rangifer tarandus platyrhynchus). We found evidence in O. gruehneri, for density-dependent regulation of female worm length in April, July and October 1999. However, it is only in July that female worm length explains the variation in the number of eggs in utero which is also related to egg production per female worm only in this month and not at other times of the year. The seasonal pattern in faecal egg output in this species focuses egg production in the summer months when conditions are favourable to transmission. In contrast, we found no evidence in the other common species (Marshallagia marshalli) for density-dependent regulation of female worm length during or the number of eggs in utero. Faecal egg output in M. marshalli was positively related to worm burden but not to the mean number of eggs in utero. Neither inter-specific interactions nor host body condition appeared to influence worm fecundity. The contrasting patterns of density-dependent regulation of fecundity provides further evidence for divergent life-histories in this nematode community.
Assuntos
Abomaso/parasitologia , Ostertagia/fisiologia , Rena/parasitologia , Trichostrongyloidea/fisiologia , Animais , Fezes/parasitologia , Feminino , Fertilidade , Masculino , Ostertagíase/veterinária , Contagem de Ovos de Parasitas/veterinária , Dinâmica Populacional , Estações do Ano , Gastropatias/parasitologia , Gastropatias/veterinária , Trichostrongyloidea/isolamento & purificação , Tricostrongiloidíase/veterináriaRESUMO
OBJECTIVE: To describe the clinical features of paramethoxyamphetamine (PMA; "death") poisoning and to compare these with those of people with self-reported "ecstasy" poisoning. DESIGN: Retrospective casenote review. PARTICIPANTS AND SETTING: 22 patients who presented to the Emergency Department of the Royal Adelaide Hospital (RAH), a major metropolitan teaching hospital, between 1 January 1996 and 31 December 1998 with PMA poisoning identified through urine drug screens; and 61 patients with self-reported ecstasy poisoning between 1 September 1997 and 31 December 1998 found through the hospital databases. RESULTS: Patients with PMA poisoning presented with tachycardia (64%), hyperthermia (temperature > 37.5 degrees C; 36%), coma (41%), seizures (32%), arrhythmias (23%), and QRS intervals > or = 100 ms (50%) with greater frequency and often greater severity than those with self-reported ecstasy poisoning. Two patients with PMA poisoning presented with severe hypoglycaemia (blood glucose level, < 1.5 mmol/L) accompanied by hyperkalaemia (K+ concentration, > 7.5 mmol/L). CONCLUSIONS: At our hospital, PMA poisonings accounted for most of the severe reactions among people who believed they had taken ecstasy. Hypoglycaemia and hyperkalaemia may be specific to PMA poisoning. PMA toxicity should be suspected with severe or atypical reactions to "ecstasy", and confirmed by chromatographic urine drug screens.
Assuntos
Anfetaminas/intoxicação , Alucinógenos/intoxicação , N-Metil-3,4-Metilenodioxianfetamina/intoxicação , Adolescente , Adulto , Serviço Hospitalar de Emergência , Feminino , Humanos , Hipertensão/induzido quimicamente , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Austrália do SulRESUMO
An experiment was conducted to evaluate moxidectin as a tool for understanding the impact of parasitism on wild Svalbard reindeer (Rangifer tarandus platyrhynchus). Adult females were injected subcutaneously with moxidectin at a dose rate of 0-4 mg/kg bodyweight, and groups of animals were culled within its expected period of efficacy (around 14 days) or around 12 or 24 weeks after treatment. Moxidectin was effective in eliminating the reindeers' abomasal worm burdens, and although they became reinfected, worm burdens were significantly lower in the treated animals compared to the untreated controls for up to 24 weeks after treatment. Nematode eggs did not reappear in faeces until five weeks after treatment, a similar period to that claimed by the manufacturer for sheep and cattle. Animals culled 12 and 24 weeks after treatment had been reinfected and harboured a wide range of abomasal worm burdens which contributed to the understanding of the seasonal variation in the relationship between faecal egg count and worm burden.
Assuntos
Antibacterianos/uso terapêutico , Antinematódeos/uso terapêutico , Gastroenterite/veterinária , Infecções por Nematoides/veterinária , Rena/parasitologia , Animais , Fezes/parasitologia , Feminino , Gastroenterite/tratamento farmacológico , Gastroenterite/parasitologia , Macrolídeos , Infecções por Nematoides/tratamento farmacológico , Estações do Ano , SvalbardRESUMO
1. This study was prompted by recent deaths that have occurred after recreational administration of the substituted amphetamine para-methoxyamphetamine (PMA). Because relatively little is known regarding its mechanism(s) of action, its effects on physiological, behavioural and neurochemical parameters were compared with the well known effects of 3,4-methylenedioxymethamphetamine (MDMA). 2. Equivalent doses of PMA (5-20 mg/kg) produced greater hypothermia than MDMA at an ambient temperature of 20 degrees C. At 30 degrees C, PMA continued to evoke hypothermia except the highest dose where hyperthermia ensued. MDMA altered body temperature only at the highest dose where hyperthermia also resulted. 3. At both 20 and 30 degrees C, MDMA stimulated locomotor activity whereas PMA had modest effects and then, only at high doses. 4. In vivo chronoamperometry was used to measure the effect of MDMA and PMA on release, and inhibition of uptake, of serotonin (5-HT) and dopamine (DA) in the dorsal striatum of anaesthetised rats. As expected, MDMA evoked release of DA and inhibited uptake of both DA and 5-HT. By contrast, PMA was a relatively weak releasing agent and did not inhibit DA uptake. However, PMA potently inhibited uptake of 5-HT. 5. Taken together these data suggest that the acute adverse effects of PMA are more likely to be associated with alterations in serotonergic rather than dopaminergic neurotransmission.
Assuntos
Alucinógenos/farmacologia , Hipotermia/induzido quimicamente , Atividade Motora/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Anfetaminas , Animais , Comportamento Animal/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Alucinógenos/efeitos adversos , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Ratos , Ratos Sprague-Dawley , Receptores de Serotonina/efeitos dos fármacos , Receptores de Serotonina/fisiologiaRESUMO
A polymerase chain reaction (PCR) assay to identify two common abomasal nematodes Marshallagia marshalli and Ostertagia gruehneri of Svalbard reindeer was developed. Species-specific PCR primers were designed from internal transcribed spacer (ITS)-2 sequences of rDNA and validated using morphologically identified adult male and female nematodes. Using the species-specific primers, a 110 bp fragment was amplified from M. marshalli and its minor morph Marshallagia occidentalis and a 149 bp fragment was amplified from Ostertagia gruehneri and its minor morph Ostertagia arctica. No PCR products were amplified from the third rare species, Teladorsagia circumcincta, or DNA from the reindeer host. The assay provides a useful tool to estimate species composition for both sexes in this nematode community.
Assuntos
Ostertagia/isolamento & purificação , Ostertagíase/veterinária , Rena/parasitologia , Trichostrongyloidea/isolamento & purificação , Tricostrongiloidíase/veterinária , Abomaso/parasitologia , Animais , Sequência de Bases , Primers do DNA/química , DNA de Helmintos/química , DNA de Helmintos/isolamento & purificação , DNA Espaçador Ribossômico/química , Feminino , Masculino , Dados de Sequência Molecular , Ostertagia/química , Ostertagia/genética , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Trichostrongyloidea/química , Trichostrongyloidea/genética , Tricostrongiloidíase/parasitologiaRESUMO
A fluorimetric assay method for the analysis of beta-glucuronidase (GUS) reporter gene expression in genetically modified plants is described. Optimization of this method for woody plants and a statistical approach suitable for comparisons of gene expression in different transformants or tissues of the same plant is described. Example data from elm (Ulmus procera) SR4 regenerant plants, shown to be genetically modified by PCR and DNA-DNA hybridizations, in which higher GUS expression levels are found in stems than in leaves demonstrates the utility of this approach.