RESUMO
Pimelea poisoning of cattle causes distinct symptoms and frequently death, attributable to the toxin simplexin. Pimelea poisoning was induced via addition of ground Pimelea trichostachya plant to the daily feed in a three-month trial with Droughtmaster steers. The trial tested four potential mitigation treatments, namely, biochar, activated biochar, bentonite, and a bacterial inoculum, and incorporated negative and positive control groups. All treatments tested were unable to prevent the development of simplexin poisoning effects. However, steers consuming a bentonite adsorbent together with Pimelea showed lesser rates-of-decline for body weight (P < 0.05) and four hematological parameters (P < 0.02), compared to the positive control group fed Pimelea only. Microbiome analysis revealed that despite displaying poisoning symptoms, the rumen microbial populations of animals receiving Pimelea were very resilient, with dominant bacterial populations maintained over time. Unexpectedly, clinical edema developed in some animals up to 2 weeks after Pimelea dosing was ceased.
Assuntos
Ração Animal , Doenças dos Bovinos , Animais , Bovinos , Ração Animal/análise , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/microbiologia , Masculino , Carvão Vegetal/administração & dosagem , Austrália , Intoxicação por Plantas/veterinária , Intoxicação por Plantas/prevenção & controle , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bentonita/química , Rúmen/microbiologia , Rúmen/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacosRESUMO
Pimelea poisoning of cattle, historically known as St. George Disease or Marree Disease, is a prevailing issue in arid grazing regions of inland Australia. Ingestion of the toxic native Pimelea species that contain the secondary metabolite simplexin, a diterpene orthoester with potent protein kinase C activity, induces diarrhoea, characteristic oedema and potentially fatal right-sided heart failure in cattle. Outbreaks of toxic Pimelea in the grazing field depend on seasonal prevalence. However, all stages of the plant carry the toxin, from seeds, juvenile plants to dead plant material. Livestock generally avoid consuming green Pimelea plants and only consume toxic Pimelea when pasture is minimal or where Pimelea growing through grass tussocks results in inadvertent ingestion. Our knowledge base of Pimelea poisoning has greatly improved with past research, yet the health hazards for livestock grazing in Pimelea affected pastures remains a significant issue whilst the ongoing search to develop effective strategies to mitigate poisoning continues. The goal of this review is to collate historical and recent research giving an overview of the current understandings of Pimelea poisoning, the toxin, its toxic effects and progress made towards remedies to alleviate the effects of Pimelea intoxication.
Assuntos
Doenças dos Bovinos/epidemiologia , Intoxicação por Plantas/veterinária , Thymelaeaceae , Animais , Bovinos , Diterpenos , Gado , Intoxicação por Plantas/epidemiologia , Terpenos , Toxinas BiológicasRESUMO
Disused mines and mining legacy require significant manpower to ameliorate the contaminated environmental surroundings following their disbanding coupled with extraordinary funding to manage these issues. Water (pH, temperature, dissolved oxygen, conductance, metals, sulphate) and total suspended solids (TSS) quality are environmental parameters that are affected by legacy mining activity and often require monitoring and rapid response if events (e.g. rainfall) occur which might affect the surrounding areas. In this study, we have monitored a famous mine site in Queensland, Australia for a number of water and sediment parameters known to be associated with acid mine drainage. This study performed analysis of water and sediment over three years, as well as rainfall data. Principal component analysis (PCA) and partial least squares (PLS) regression was undertaken to investigate the data obtained. It was found that the use of PCA can predict the effect of year and site on the environmental influence of the abandoned mine site, based on the combination of chemical properties and meteorological data.
RESUMO
Patients in seven hospitals for the mentally handicapped were screened for markers of hepatitis B infection. Of 2239 patients, 123 (5.5 per cent) were carriers of hepatitis B surface antigen (HBsAg) and a third of these were 'infectious' (negative for antibody to hepatitis B e antigen). Patients with Down's syndrome (DS) were 18 times more likely to be 'infectious' carriers than those without, and male patients were six times more likely to be 'infectious' carriers than female patients. There was a wide difference in carrier rate among the various hospitals. In the hospital with the highest carrier rate (12.5 per cent), 60 per cent of male patients with DS were carriers of HBsAg and of these two-thirds were 'infectious'. The carrier rate decreased with age, but the proportion of carriers who were hepatitis B e antigen positive was unaffected by age.