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1.
J Hosp Infect ; 110: 37-44, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33484781

RESUMO

BACKGROUND: Infection is the second highest cause of mortality in end-stage renal disease, with a significant proportion relating to haemodialysis (HD) vascular access-related infection (VARI). AIM: To report the rate and antimicrobial resistance (AMR) of all-source bloodstream infections (BSIs) by vascular access type in a Scottish HD cohort. METHODS: Retrospective analysis was undertaken of data on adult patients attending seven HD units during 2017. Total HD days for each vascular access type were calculated. BSIs were analysed with rates expressed per 1000 HD days. AMR was verified using health board microbiology databases. FINDINGS: Excluding contaminant organisms, there was an overall BSI rate of 0.57 per 1000 HD days. The highest all-source and vascular access-related infection (VARI) BSI rates per 1000 HD days were in the non-tunnelled central venous catheter (CVC) group (3.11 and 2.07 respectively), followed by tunnelled CVC (1.10 and 0.67), arteriovenous graft (0.51 and 0.31), and finally arteriovenous fistula (0.29 and 0.02). The non-VARI BSI rates were lowest in the arteriovenous graft group. Staphylococci comprised the majority of events, with Staphylococcus aureus implicated in 29%. Gram-negative BSIs were prevalent, particularly in CVC groups, and associated with higher mortality. Multidrug-resistant (MDR) S. aureus and carbapenem resistance were relatively low. MDR Gram-negatives were high compared with the Scottish population. CONCLUSION: Arteriovenous fistula access is confirmed as having lowest all-source and VARI BSI rates, and arteriovenous graft access the lowest non-VARI BSI rates. Staphylococci remain the prevailing genus; however, the contributions of Gram-negative BSIs, the higher mortality, and proportion of MDR organisms in this group are notable.


Assuntos
Bacteriemia , Infecções Relacionadas a Cateter , Diálise Renal , Sepse , Adulto , Fístula Arteriovenosa , Bacteriemia/epidemiologia , Infecções Relacionadas a Cateter/epidemiologia , Cateteres Venosos Centrais , Infecções por Bactérias Gram-Negativas/epidemiologia , Humanos , Estudos Retrospectivos , Escócia/epidemiologia , Sepse/epidemiologia , Staphylococcus aureus , Enxerto Vascular
2.
Osteoporos Int ; 31(12): 2439-2448, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32719992

RESUMO

Adiposity has a complex relationship with bone health. In 4865 Australian baby boomers (2642 females) aged 45-70 years, we found that higher visceral adipose tissue mass is associated with reduced bone density adjusting for body mass and lifestyle factors, suggesting that excess visceral fat may be deleterious to bone. INTRODUCTION: Increased body mass is associated with higher bone mineral density (BMD), but higher visceral adipose tissue (VAT) may have a negative impact on bone health. In the Busselton Healthy Ageing Study, we examined associations between VAT mass and BMD in 4865 participants (2642 females) aged 45-70 years. METHODS: VAT mass and BMD of whole body, total hip, femoral neck and lumbar spine were measured using DXA. VAT mass was examined as a continuous variable and in quartiles using sex-specific cut-offs. RESULTS: The mean age was 58.0 ± 5.8 years. Males had significantly higher BMI (28.3 ± 3.7 vs 27.5 ± 4.9 kg/m2) and VAT mass (1675 ± 878 vs 882 ± 600 g) than females (both P < 0.001). In males, after adjustment for age, body mass, height and lifestyle factors, VAT mass negatively associated with total body, total hip and femoral neck BMD (ß = - 0.153 to - 0.293, all P < 0.001). Males in the highest quartile of VAT mass (> 2200 g) had significantly lower BMD at all three sites than those in lower quartiles, with estimated BMD differences of 2.3-5.7% (all P < 0.05). In females, VAT mass negatively associated with total body, femoral neck and lumbar spine BMD (ß = - 0.067 to - 0.178, all P < 0.05) and those in the highest quartile (> 1250 g) had significantly lower total body BMD than other quartiles (by 1.7-3.7%, all P < 0.05). CONCLUSION: In middle-aged Australians, after covariate adjustment, higher DXA-derived VAT mass is associated with reduced bone density, suggesting that excess visceral fat may be deleterious to bone, especially in males.


Assuntos
Densidade Óssea , Gordura Intra-Abdominal , Absorciometria de Fóton , Tecido Adiposo , Adiposidade , Idoso , Austrália/epidemiologia , Feminino , Colo do Fêmur , Humanos , Gordura Intra-Abdominal/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade
3.
Transbound Emerg Dis ; 65(2): e470-e477, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29250929

RESUMO

Mortality caused by rabbit haemorrhagic disease virus (RHDV) in wild rabbits is reduced in parts of Australia where the related, non-pathogenic calicivirus RCV-A1 is endemic. Laboratory experiments previously showed that prior infection with RCV-A1 enabled rabbits to better withstand subsequent infection with highly virulent RHDV, and this was assumed to explain higher survival. Here, we analyse serological data from the field suggesting that reduced mortality rates among wild rabbits may also result from rabbits previously infected with RCV-A1 having a reduced likelihood of RHDV infection. We discuss the possible mechanisms underlying this finding and its implications. The methods we describe for analysing field data gave far greater insights into epidemiological processes and virus interactions than gained from reporting basic seroprevalence rates alone.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Caliciviridae/mortalidade , Infecções por Caliciviridae/veterinária , Proteção Cruzada , Vírus da Doença Hemorrágica de Coelhos/imunologia , Animais , Austrália/epidemiologia , Infecções por Caliciviridae/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Vírus da Doença Hemorrágica de Coelhos/patogenicidade , Coelhos , Estudos Soroepidemiológicos
4.
Int J Parasitol ; 47(12): 701-710, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28893636

RESUMO

Apicomplexan parasites such as Babesia, Theileria, Eimeria, Cryptosporidium and Toxoplasma greatly impact animal health globally, and improved, cost-effective measures to control them are urgently required. These parasites have complex multi-stage life cycles including obligate intracellular stages. Major gaps in our understanding of the biology of these relatively poorly characterised parasites and the diseases they cause severely limit options for designing novel control methods. Here we review potentially important shared aspects of the biology of these parasites, such as cell invasion, host cell modification, and asexual and sexual reproduction, and explore the potential of the application of relatively well-established or newly emerging genetic manipulation methods, such as classical transfection or gene editing, respectively, for closing important gaps in our knowledge of the function of specific genes and proteins, and the biology of these parasites. In addition, genetic manipulation methods impact the development of novel methods of control of the diseases caused by these economically important parasites. Transient and stable transfection methods, in conjunction with whole and deep genome sequencing, were initially instrumental in improving our understanding of the molecular biology of apicomplexan parasites and paved the way for the application of the more recently developed gene editing methods. The increasingly efficient and more recently developed gene editing methods, in particular those based on the CRISPR/Cas9 system and previous conceptually similar techniques, are already contributing to additional gene function discovery using reverse genetics and related approaches. However, gene editing methods are only possible due to the increasing availability of in vitro culture, transfection, and genome sequencing and analysis techniques. We envisage that rapid progress in the development of novel gene editing techniques applied to apicomplexan parasites of veterinary interest will ultimately lead to the development of novel and more efficient methods for disease control.


Assuntos
Apicomplexa/fisiologia , Infecções Protozoárias em Animais/parasitologia , Animais , Apicomplexa/genética , Apicomplexa/crescimento & desenvolvimento , Apicomplexa/patogenicidade , Sistemas CRISPR-Cas , Reparo do DNA , Desoxirribonucleases/metabolismo , Edição de Genes , Técnicas de Inativação de Genes , Genoma de Protozoário , Estágios do Ciclo de Vida , Mutagênese Insercional , Infecções Protozoárias em Animais/economia , Infecções Protozoárias em Animais/prevenção & controle , Vacinas Protozoárias , Transfecção , Fatores de Virulência/fisiologia
5.
Osteoporos Int ; 28(1): 259-268, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27468902

RESUMO

The obesity-BMD relationship is complex. In 3045 middle-aged adults, we found that in women (but not men) with discordant fat mass index (FMI)/BMI categories, higher body fat for BMI was associated with lower BMD, suggesting that increased fat mass without an accompanying increase in lean mass may be deleterious to bone. INTRODUCTION: The relationship between obesity and BMD is complex. FMI (fat mass (kg) / height (m)2) is a more accurate measure of fatness than BMI, and depending on body composition, some individuals have discordant BMI/FMI categories. We examined associations between FMI, BMI and BMD in participants in the Busselton Healthy Ageing Study. METHODS: Body composition and BMD of the hip, spine and total body were measured using DXA in 3045 participants (1644 females) aged 45-67 years. Using standard BMI/FMI categories, the participants were classified as underweight/fat deficit, normal, overweight/excess fat, obese I and obese II-III. RESULTS: BMI and FMI categories were concordant in 77.3 % of females and 71.2 % of males. There were 12.9 % females and 13.2 % males in a higher FMI than BMI category (high body fat for BMI), whereas 9.8 % females and 15.6 % males were in a lower category (low body fat for BMI). Females with high body fat for BMI had significantly lower covariate-adjusted BMD at the femoral neck, total hip and total body (differences of 3.8, 5.1 and 2.6 %, respectively, all P < 0.05) than females with low body fat for BMI and lower total body BMD than women with concordant FMI/BMI (by 1.4 %, P = 0.04). In males, BMD did not differ significantly between those who were concordant or discordant for FMI/BMI categories. CONCLUSION: In women (but not men) with discordant FMI/BMI categories, higher body fat for BMI was associated with lower BMD, suggesting that increased fat mass without an accompanying increase in lean mass may be deleterious to bone.


Assuntos
Tecido Adiposo/anatomia & histologia , Índice de Massa Corporal , Densidade Óssea/fisiologia , Caracteres Sexuais , Absorciometria de Fóton/métodos , Tecido Adiposo/fisiologia , Idoso , Antropometria/métodos , Composição Corporal/fisiologia , Feminino , Envelhecimento Saudável/fisiologia , Articulação do Quadril/fisiologia , Humanos , Vértebras Lombares/fisiologia , Masculino , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia
6.
Soft Matter ; 12(48): 9803-9820, 2016 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-27858055

RESUMO

Brownian dynamics simulations are used to study the detachment of a particle from a substrate. Although the model is simple and generic, we attempt to map its energy, length and time scales onto a specific experimental system, namely a bead that is weakly bound to a cell and then removed by an optical tweezer. The external driving force arises from the combined optical tweezer and substrate potentials, and thermal fluctuations are taken into account by a Brownian force. The Jarzynski equality and Crooks fluctuation theorem are applied to obtain the equilibrium free energy difference between the final and initial states. To this end, we sample non-equilibrium work trajectories for various tweezer pulling rates. We argue that this methodology should also be feasible experimentally for the envisioned system. Furthermore, we outline how the measurement of a whole free energy profile would allow the experimentalist to retrieve the unknown substrate potential by means of a suitable deconvolution. The influence of the pulling rate on the accuracy of the results is investigated, and umbrella sampling is used to obtain the equilibrium probability of particle escape for a variety of trap potentials.

7.
Ecol Appl ; 26(8): 2621-2634, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27862568

RESUMO

Most species that are negatively impacted when their densities are low aggregate to minimize this effect. Aggregation has the potential to change how Allee effects are expressed at the population level. We studied the interplay between aggregation and Allee effects in the mountain pine beetle (Dendroctonus ponderosae Hopkins), an irruptive bark beetle that aggregates to overcome tree defenses. By cooperating to surpass a critical number of attacks per tree, the mountain pine beetle is able to breach host defenses, oviposit, and reproduce. Mountain pine beetles and Hymenopteran parasitoids share some biological features, the most notable of which is obligatory host death as a consequence of parasitoid attack and development. We developed spatiotemporal models of mountain pine beetle dynamics that were based on the Nicholson-Bailey framework but which featured beetle aggregation and a tree-level attack threshold. By fitting our models to data from a local mountain pine beetle outbreak, we demonstrate that due to aggregation, attack thresholds at the tree level can be overcome by a surprisingly low ratio of beetles per susceptible tree at the stand level. This results confirms the importance of considering aggregation in models of organisms that are subject to strong Allee effects.


Assuntos
Besouros , Animais , Pinus , Dinâmica Populacional , Árvores , Gorgulhos
8.
Epidemiol Infect ; 140(11): 1972-81, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22244198

RESUMO

Rabbit haemorrhagic disease is a major tool for the management of introduced, wild rabbits in Australia. However, new evidence suggests that rabbits may be developing resistance to the disease. Rabbits sourced from wild populations in central and southeastern Australia, and domestic rabbits for comparison, were experimentally challenged with a low 60 ID50 oral dose of commercially available Czech CAPM 351 virus - the original strain released in Australia. Levels of resistance to infection were generally higher than for unselected domestic rabbits and also differed (0-73% infection rates) between wild populations. Resistance was lower in populations from cooler, wetter regions and also low in arid regions with the highest resistance seen within zones of moderate rainfall. These findings suggest the external influences of non-pathogenic calicivirus in cooler, wetter areas and poor recruitment in arid populations may influence the development rate of resistance in Australia.


Assuntos
Animais Selvagens/virologia , Infecções por Caliciviridae/veterinária , Resistência à Doença , Vírus da Doença Hemorrágica de Coelhos , Espécies Introduzidas , Análise de Variância , Animais , Animais Selvagens/imunologia , Austrália , Agentes de Controle Biológico , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/mortalidade , Clima , Feminino , Estimativa de Kaplan-Meier , Masculino , Coelhos , Chuva
9.
J Neuroendocrinol ; 23(1): 65-73, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20874778

RESUMO

The medial amygdala (MeA) is an important site for the gonadal hormone control of several socio-sexual behaviours that emerge during puberty, including aggression, mating and parental behaviour. We have previously shown that rising levels of pubertal androgens increase the regional volume and mean soma size of neurones in the posterodorsal subnucleus of the MeA, the MePD. The present study aimed to determine some of the constituents of pubertal volumetric growth. Using computer-guided unbiased stereology, we compared the regional volume, mean somal volume and the overall number of neurones and glia in 45-day-old male Siberian hamsters (Phodopus sungorus). Half of the hamsters had completed puberty, whereas the remainder were prepubertal as a result of photoinhibition of the hypothalamic-pituitary-gonadal axis. Puberty significantly increased MePD regional volume and mean somal volume, as previously observed. We also compared the number of puncta immunoreactive for vesicular glutamate transporter-2 (vGlut2) and post-synaptic density 95 (PSD-95), which are both markers of glutamatergic pre- and post-synaptic specialisations, as well as glutamic acid decarboxylase 65 (GAD-65), which is a marker of GABAergic terminals. Puberty increased the number of vGlut2 and PSD-95 immunoreactive puncta by two- and three-fold, respectively, whereas the number of GAD-65 immunoreactive puncta was unchanged. These results suggest that numerous excitatory synapses are added to the MeA during puberty. More broadly, they show that the pubertal emergence of sexual behaviour is accompanied by synaptic reorganisation of a key network involved in the expression of sexual behaviour.


Assuntos
Tonsila do Cerebelo/anatomia & histologia , Maturidade Sexual , Sinapses , Animais , Cricetinae , Feminino , Imuno-Histoquímica , Masculino , Phodopus
10.
J S Afr Vet Assoc ; 80(2): 75-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19831266

RESUMO

Babesia canis and B. rossi are large Babesia species that infect dogs and cause clinical disease. The spectrum of disease is highly diverse with either parasite, but upon evaluation of field cases it has been suggested that in general B. rossi is more virulent than B. canis. This difference was also found in experimental infections using B. canis and B. rossi isolates and appeared to be related to a difference in parasitaemia. Whether this difference reflects the essential difference between B. canis and B. rossi species in general, or merely reflects the variability in virulence of individual isolates cannot be discerned. Comparative in vitro and in vivo studies revealed a number of qualitative differences between the B. canis and B. rossi isolates studied; however, more research is required to determine any causal relationship between in vitro and in vivo characteristics. Vaccination with a bivalent vaccine (containing soluble parasite antigen [SPA] from supernatants of in vitro cultures of B. canis and B. rossi) induced protection against clinical babesiosis upon challenge infection with either parasite. The dynamics of parasitaemia upon challenge infection of vaccinated animals indicated a biological difference between the B. canis and B. rossi isolates studied. Vaccinated dogs that were challenged with B. rossi parasites (2 isolates tested) effectively controlled parasitaemia. By contrast, in vaccinated dogs that were challenged with B. canis isolates (2 isolates tested) there was little or no effect on parasitaemia but levels of SPA in plasma were reduced. Apparently the nature of vaccine-induced immunity differs with respect to the challenge species.


Assuntos
Antígenos de Protozoários/imunologia , Babesia/imunologia , Babesiose/veterinária , Doenças do Cão/parasitologia , Vacinas Protozoárias/imunologia , Animais , Babesia/classificação , Babesia/patogenicidade , Babesiose/parasitologia , Babesiose/prevenção & controle , Doenças do Cão/prevenção & controle , Cães , Vacinas Protozoárias/administração & dosagem , Vacinação/veterinária , Virulência
11.
Phytopathology ; 98(1): 69-78, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18943240

RESUMO

ABSTRACT Over 4 years, the environmental conditions and the causal agents of Fusarium head blight (FHB) disease of wheat were determined in field sites in four European countries: Hungary, Ireland, Italy, and the United Kingdom. Polymerase chain reaction-based methods were used to detect each species causing FHB and quantify its DNA (as a measurement of fungal abundance) in the samples. Canonical correspondence analysis (CCA) was used to determine the relationship of the incidence and abundance of each species with weather variables. CCA indicated that little variability in the species prevalence data was explained by the weather variables. In contrast, a greater proportion of variability in abundance data was accounted for by the weather variables. Most samples contained two or more species and statistical analysis suggested that these species tended to coexist at field sites. CCA also indicated that there were differences in the relationships of the prevalence and abundance of the six FHB species with environmental variables. Fusarium poae was associated with relatively drier and warmer conditions, whereas F. graminearum was associated with warmer/humid conditions. F. avenaceum and F. culmorum were both associated with niches of cooler/wet/humid conditions. Two Microdochium species were associated with regions of relatively cool/moderate temperatures and frequent rainfalls of short duration. The results also suggested that environmental conditions differentially affect the infection and colonization processes, and the comparative abundance of the six species.


Assuntos
Ascomicetos/fisiologia , Meio Ambiente , Fusarium/fisiologia , Doenças das Plantas/microbiologia , Triticum/microbiologia , Interações Hospedeiro-Patógeno
12.
Anticancer Res ; 27(1B): 647-52, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17348455

RESUMO

BACKGROUND: Breast conservation therapy (BCT) is recommended as standard management of early breast cancer. The aim of this study was to retrospectively evaluate the results of BCT to identify prognostic factors predictive of treatment outcomes. PATIENTS AND METHODS: Four hundred and ninety-eight eligible women with unilateral stage I-II breast cancer who had undergone BCT were analyzed. RESULTS: The cumulative incidence of local recurrence (LR) was 1.9% and 3.7% at 3- and 5-years respectively. The 5-year disease-free, cancer-specific, and overall survival (DFS, CSS, OS) were 80.0%, 87.3% and 85.4% respectively. Significant independent predictors for LR included young age and absence of chemotherapy. Regional nodal radiotherapy was significantly associated with improved DFS and OS. CONCLUSION: Our results confirmed the efficacy of BCT in the treatment of early breast cancer and indicated that inclusion of regional nodal areas within the radiotherapy field might be beneficial in the BCT setting, particularly for patients with adverse risk features.


Assuntos
Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Mastectomia Segmentar , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Prognóstico , Radioterapia Adjuvante , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
13.
Neuroscience ; 138(3): 997-1005, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16330154

RESUMO

Behavioral sex differences have traditionally been thought to arise from gonadal steroids during a neonatal sensitive period. However, it is possible to sex-reverse certain behaviors by reversing the levels of circulating androgen in adult males and females. These results suggest that the sexually dimorphic substrates of sex behavior are subject to a high degree of plasticity, even in adulthood. I have found that circulating androgen exerts a trophic effect on the Nissl-stained morphology of an important nucleus in the control of sex behavior, namely, the posterodorsal subnucleus of the medial amygdala. First, sex-reversing the level of circulating androgen reversed the sex difference in soma size and regional volume of the posterodorsal subnucleus of the medial amygdala in adult rats. Interestingly, activation of both androgen and estrogen receptors was necessary for the post-castration maintenance of a masculine phenotype in terms of posterodorsal subnucleus of the medial amygdala cell size, whereas only estrogen receptor activity was necessary to maintain a masculine posterodorsal subnucleus of the medial amygdala volume. Then, we showed that seasonal variation in androgen was correlated with morphologic plasticity in the posterodorsal subnucleus of the medial amygdala of the Siberian hamster. However, if the experimental males were housed with females, their posterodorsal subnucleus of the medial amygdalas failed to regress in response to winter-like short daylengths. Furthermore, when male hamsters were castrated and treated with testosterone, the posterodorsal subnucleus of the medial amygdala responded to the hormone only if the animals were in summer-like photoperiods. Overall, these findings indicate that circulating androgens are critical for the maintenance of greater posterodorsal subnucleus of the medial amygdala regional volumes and soma sizes, and that environmental variables can regulate testosterone secretion and responsiveness.


Assuntos
Tonsila do Cerebelo/fisiologia , Androgênios/fisiologia , Estrogênios/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Encéfalo/fisiologia , Feminino , Lateralidade Funcional , Masculino , Fotoperíodo , Prosencéfalo/fisiologia , Ratos , Caracteres Sexuais , Comportamento Sexual Animal
14.
Mol Ecol ; 14(10): 3167-75, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16101782

RESUMO

Wild rabbits (Oryctolagus cuniculus) in Australia are the descendents of 24 animals from England released in 1859. We surveyed rabbits and rabbit fleas (Spilopsyllus cuniculi) in Australia for the presence of trypanosomes using parasitological and PCR-based methods. Trypanosomes were detected in blood from the European rabbits by microscopy, and PCR using trypanosome-specific small subunit ribosomal RNA (SSU rRNA) gene primers and those in rabbit fleas by PCR. This is the first record of trypanosomes from rabbits in Australia. We identified these Australian rabbit trypanosomes as Trypanosoma nabiasi, the trypanosome of the European rabbit, by comparison of morphology and SSU rRNA gene sequences of Australian and European rabbit trypanosomes. Phylogenetic analysis places T. nabiasi in a clade with rodent trypanosomes in the subgenus Herpetosoma and their common link appears to be transmission by fleas. Despite the strict host specificity of trypanosomes in this clade, phylogenies presented here suggest that they have not strictly cospeciated with their vertebrate hosts. We suggest that T. nabiasi was inadvertently introduced into Australia in the 1960s in its flea vector Spilopsyllus cuniculi, which was deliberately introduced as a potential vector of the myxoma virus. In view of the environmental and economic damage caused by rabbits in Australia and other islands, the development of a virulent or genetically modified T. nabiasi should be considered to control rabbits.


Assuntos
Controle Biológico de Vetores , Coelhos/parasitologia , Trypanosoma/crescimento & desenvolvimento , Tripanossomíase/veterinária , Animais , Austrália , DNA de Protozoário/química , DNA de Protozoário/genética , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 18S/química , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Sifonápteros/parasitologia , Trypanosoma/genética , Tripanossomíase/parasitologia
15.
Plant Dis ; 89(4): 404-411, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30795457

RESUMO

A large environmental influence on phenotypic estimates of disease resistance and the complex polygenic nature of Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) are impediments to developing resistant cultivars. The objective of this research was to investigate the utility of a detached leaf assay, inoculated using inoculum from isolates of Microdochium nivale var. majus, to identify components of FHB resistance among 30 entries of U.S. soft red winter wheat in the 2002 Uniform Southern FHB Nursery (USFHBN). Whole plant FHB resistance of the USFHBN entries was evaluated in replicated, mist-irrigated field trials at 10 locations in eight states during the 2001-2002 season. Incubation period (days from inoculation to the first appearance of a dull gray-green water-soaked lesion) was the only detached leaf variable significantly correlated across all FHB resistance parameters accounting for 45% of the variation in FHB incidence, 27% of FHB severity, 30% of Fusarium damaged kernels, and 26% of the variation in grain deoxynivalenol (DON) concentration. The results for incubation period contrasted with previous studies of moderately resistant European cultivars, in that longer incubation period was correlated with greater FHB susceptibility, but agreed with previous findings for the Chinese cultivar Sumai 3 and CIMMYT germ plasm containing diverse sources of FHB resistance. The results support the view that the detached leaf assay method has potential for use to distinguish between specific sources of FHB resistance when combined with data on FHB reaction and pedigree information. For example, entry 28, a di-haploid line from the cross between the moderately resistant U.S. cultivar Roane and the resistant Chinese line W14, exhibited detached leaf parameters that suggested a combination of both sources of FHB resistance. The USFHBN represents the combination of adapted and exotic germ plasm, but four moderately resistant U.S. commercial cultivars (Roane, McCormick, NC-Neuse, and Pat) had long incubation and latent periods and short lesion lengths in the detached leaf assay as observed in moderately FHB resistant European cultivars. The dichotomy in the relationship between incubation period and FHB resistance indicates that this may need to be considered to effectively combine exotic and existing/adapted sources of FHB resistance.

16.
Breast ; 12(2): 92-8, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14659337

RESUMO

The tests that are currently available for the measurement of overexpression of the human epidermal growth factor-2 (HER2) in breast cancer have shown considerable problems in accuracy and interlaboratory reproducibility. Although these problems are partly alleviated by the use of validated, standardised 'kits', there may be considerable cost involved in their use. Prior to testing it may therefore be an advantage to be able to predict from basic pathology data whether a cancer is likely to overexpress HER2. In this study, we have correlated pathology features of cancers with the frequency of HER2 overexpression assessed by immunohistochemistry (IHC) using HercepTest (Dako). In addition, fluorescence in situ hybridisation (FISH) has been used to re-test the equivocal cancers and interobserver variation in assessing HER2 overexpression has been examined by a slide circulation scheme. Of the 1536 cancers, 1144 (74.5%) did not overexpress HER2. Unequivocal overexpression (3+ by IHC) was seen in 186 cancers (12%) and an equivocal result (2+ by IHC ) was seen in 206 cancers (13%). Of the 156 IHC 3+ cancers for which complete data was available, 149 (95.5%) were ductal NST and 152 (97%) were histological grade 2 or 3. Only 1 of 124 infiltrating lobular carcinomas (0.8%) showed HER2 overexpression. None of the 49 'special types' of carcinoma showed HER2 overexpression. Re-testing by FISH of a proportion of the IHC 2+ cancers showed that only 25 (23%) of those assessable exhibited HER2 gene amplification, but 46 of the 47 IHC 3+ cancers (98%) were confirmed as showing gene amplification. Circulating slides for the assessment of HER2 score showed a moderate level of agreement between pathologists (kappa 0.4). As a result of this study we would advocate consideration of a triage approach to HER2 testing. Infiltrating lobular and special types of carcinoma may not need to be routinely tested at presentation nor may grade 1 NST carcinomas in which only 1.4% have been shown to overexpress HER2. Testing of these carcinomas may be performed when HER2 status is required to assist in therapeutic or other clinical/prognostic decision-making. The highest yield of HER2 overexpressing carcinomas is seen in the grade 3 NST subgroup in which 24% are positive by IHC.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Receptor ErbB-2/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Neoplasias da Mama/mortalidade , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Hibridização In Situ , Cooperação Internacional , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Probabilidade , Prognóstico , Estudos Prospectivos , Receptor ErbB-2/genética , Medição de Risco , Sensibilidade e Especificidade
17.
Hum Reprod ; 18(8): 1603-12, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12871869

RESUMO

BACKGROUND: Follicular fluid (FF) contains compounds that can modulate NADP(+)-dependent oxidation of cortisol by type 1 11beta-hydroxysteroid dehydrogenase (11betaHSD). The objective of this study was to investigate the relationships between levels of the ovarian modulators of type 1 11betaHSD, intra-follicular cortisol:cortisone ratios and the clinical outcome of IVF cycles. METHODS: A single random sample of FF was aspirated from each of 132 patients undergoing gonadotrophin-stimulated IVF. Components of FF, resolved using C18 column chromatography, were evaluated for effects on NADP(+)-dependent cortisol oxidation in rat kidney homogenates. Intra- follicular steroid concentrations were measured by radioimmunoassays. Clinical pregnancies were confirmed by ultrasonography at 6 weeks post-embryo transfer. RESULTS: Levels of the hydrophilic ovarian 11betaHSD stimuli were significantly lower (P<0.0001) and levels of the hydrophobic ovarian 11betaHSD inhibitors were significantly higher (P<0.002) in conception versus non-conception cycles. Intra-follicular cortisol:cortisone ratios increased with the degree of inhibition of 11betaHSD by the hydrophobic FF fractions. FF obtained from conception cycles had significantly higher cortisol:cortisone ratios than samples from non-conception cycles (12.9+/-0.3 versus 8.5+/-0.2, respectively; P<0.0001). CONCLUSIONS: Conception by IVF is associated with elevated intra-follicular cortisol:cortisone ratios, which reflect low levels of ovarian stimuli and/or high levels of ovarian inhibitors of type 1 11betaHSD.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Cortisona/metabolismo , Fertilização in vitro , Hidrocortisona/metabolismo , Ovário/metabolismo , Adulto , Animais , Bioensaio , Feminino , Líquido Folicular/metabolismo , Humanos , Técnicas In Vitro , Rim/metabolismo , NADP/metabolismo , Oxirredução , Gravidez , Resultado da Gravidez , Ratos
18.
Rev Sci Tech ; 22(1): 283-96, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12793786

RESUMO

Pigs and poultry in the United Kingdom have undeniably been exposed to the bovine spongiform encephalopathy (BSE) agent. They consumed the same ruminant protein that gave rise to the BSE epidemic in cattle, but there has been no evidence of an epidemic in these species. Experimental investigations have shown pigs to be susceptible to infection by multiple parenteral challenge, but resistant to oral exposure with BSE-infected cattle brain. Current but incomplete evidence suggests that they are also resistant to oral challenge with sheep scrapie. Studies in domestic chickens indicate that they are resistant to both parenteral and oral challenge. Unfortunately, no published data exists on the susceptibility of fish to infection. Incidental findings in the brains of unexposed pigs are described that could otherwise give rise to concerns aboutthe presence of a transmissible spongiform encephalopathy in pig populations around the world.


Assuntos
Ração Animal/efeitos adversos , Galinhas , Doenças das Aves Domésticas/etiologia , Doenças Priônicas/veterinária , Doenças dos Suínos/etiologia , Animais , Portador Sadio/veterinária , Doenças dos Peixes/etiologia , Doenças dos Peixes/genética , Peixes , Predisposição Genética para Doença , Doenças das Aves Domésticas/genética , Doenças Priônicas/etiologia , Doenças Priônicas/genética , Suínos , Doenças dos Suínos/genética
19.
Mol Ecol ; 11(12): 2703-9, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12453252

RESUMO

European wild rabbits originated in southwestern Europe but have been introduced into many other countries world-wide, becoming serious pests in many instances. As a consequence of rabbits being regarded so differently, applied research for their management often has opposing goals, namely their conservation or their control. Furthermore, modern gene technology has led to the concept of using genetically modified myxoma viruses for rabbit management, again with quite contrary aims in mind. In this paper we explain the possible ecological and economic consequences of using these genetically modified viruses inappropriately and we consider whether national and international regulations are sufficient to prevent improper use. If international regulations are inadequate, molecular biologists and ecologists must consider the consequences of their research and advice beyond their own country to avoid unwanted impacts.


Assuntos
Conservação dos Recursos Naturais/métodos , Vírus da Doença Hemorrágica de Coelhos/genética , Myxoma virus/genética , Organismos Geneticamente Modificados , Controle Biológico de Vetores/métodos , Coelhos/crescimento & desenvolvimento , Coelhos/virologia , Animais , Austrália , Conservação dos Recursos Naturais/legislação & jurisprudência , Ecologia , Vírus da Doença Hemorrágica de Coelhos/imunologia , Myxoma virus/imunologia , Controle Biológico de Vetores/legislação & jurisprudência , Coelhos/imunologia , Espanha
20.
Med J Aust ; 176(10): 500, 2002 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-12068833
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