► Myxomatosis is the classic example of virus/host coevolution. ► Myxoma virus was introduced into Australia as a control for the European rabbit. ► The subsequent coevolution of the virus and its ...new host was studied in real time.
Myxoma virus is a poxvirus naturally found in two American leporid (rabbit) species (Sylvilagus brasiliensis and Sylvilagus bachmani) in which it causes an innocuous localised cutaneous fibroma. However, in European rabbits (Oryctolagus cuniculus) the same virus causes the lethal disseminated disease myxomatosis. The introduction of myxoma virus into the European rabbit population in Australia in 1950 initiated the best known example of what happens when a novel pathogen jumps into a completely naïve new mammalian host species. The short generation time of the rabbit and their vast numbers in Australia meant evolution could be studied in real time. The carefully documented emergence of attenuated strains of virus that were more effectively transmitted by the mosquito vector and the subsequent selection of rabbits with genetic resistance to myxomatosis is the paradigm for pathogen virulence and host–pathogen coevolution. This natural experiment was repeated with the release of a separate strain of myxoma virus in France in 1952. The subsequent spread of the virus throughout Europe and its coevolution with the rabbit essentially paralleled what occurred in Australia. Detailed molecular studies on myxoma virus have dissected the role of virulence genes in the pathogenesis of myxomatosis and when combined with genomic data and reverse genetics should in future enable the understanding of the molecular evolution of the virus as it adapted to its new host. This review describes the natural history and evolution of myxoma virus together with the molecular biology and experimental pathogenesis studies that are informing our understanding of evolution of emerging diseases.
Summary More than 2 million people worldwide are being treated for end-stage kidney disease (ESKD). This Series paper provides an overview of incidence, modality use (in-centre haemodialysis, home ...dialysis, or transplantation), and mortality for patients with ESKD based on national registry data. We also present data from an international cohort study to highlight differences in haemodialysis practices that affect survival and the experience of patients who rely on this therapy, which is both life-sustaining and profoundly disruptive to their quality of life. Data illustrate disparities in access to renal replacement therapy of any kind and in the use of transplantation or home dialysis, both of which are widely considered preferable to in-centre haemodialysis for many patients with ESKD in settings where infrastructure permits. For most patients with ESKD worldwide who are treated with in-centre haemodialysis, overall survival is poor, but longer in some Asian countries than elsewhere in the world, and longer in Europe than in the USA, although this gap has reduced. Commendable haemodialysis practice includes exceptionally high use of surgical vascular access in Japan and in some European countries, and the use of longer or more frequent dialysis sessions in some countries, allowing for more effective volume management. Mortality is especially high soon after ESKD onset, and improved preparation for ESKD is needed including alignment of decision making with the wishes of patients and families.
Motivated by recent high-profile cases of salespeople behaving ‘badly’ (i.e., unethically, aggressively, or misleading toward customers), we investigate traditional behavioral controls to examine the ...specific relationship between performance measurement choices and selling behavior with a survey of 207 business-to-business salespeople. Borrowing from attention-based theory and the theory of planned behavior, our findings suggest that sales management can encourage more pro-customer behavior by using a more diverse performance measurement schema to influence the underlying drivers of customer-oriented selling behavior, including salesperson attitudes and subjective norms. This is particularly important in transactional selling environments where the use of diverse measures has the strongest effect on pro-customer attitudes and customer-oriented selling behavior.
•Increased performance measurement diversity is linked to customer-oriented selling behavior.•Salesperson attitudes are chiefly responsible for higher levels of customer-oriented selling behavior.•The influence of attitudes on customer-oriented selling is most acute in less complex, transactional selling situations.
Altered bone structure and function contribute to the high rates of fractures in dialysis patients compared to the general population. Fracture events may increase the risk of subsequent adverse ...clinical outcomes. Here we assessed the incidence of post-fracture morbidity and mortality in an international cohort of 34,579 in-center hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS). We estimated country-specific rates of fractures requiring a hospital admission and associated length of stay in the hospital. Incidence rates of death and of a composite event of death/rehospitalization were estimated for 1 year after fracture. Overall, 3% of participants experienced a fracture. Fracture incidence varied across countries, from 12 events/1000 patient-years (PY) in Japan to 45/1000 PY in Belgium. In all countries, fracture rates were higher in the hemodialysis group compared to those reported for the general population. Median length of stay ranged from 7 to 37 days in the United States and Japan, respectively. In most countries, postfracture mortality rates exceeded 500/1000 PY and death/rehospitalization rates exceeded 1500/1000 PY. Fracture patients had higher unadjusted rates of death (3.7-fold) and death/rehospitalization (4.0-fold) compared to the overall DOPPS population. Mortality and hospitalization rates were highest in the first month after the fracture and declined thereafter. Thus, the high frequency of fractures and increased adverse outcomes following a fracture pose a significant health burden for dialysis patients. Fracture prevention strategies should be identified and applied broadly in nephrology practices.
The Fragility Index is a tool for testing robustness of randomized controlled trial results for dichotomous outcomes. It describes the minimum number of individuals in whom changing an event status ...would render a statistically significant result nonsignificant. Here we identified all randomized controlled trials in five nephrology and five general journals from 2005-2014. A total of 127 randomized controlled trials reporting at least one dichotomous statistically significant outcome (p less than 0.05) were included and the Fragility Index was calculated. Twenty randomized controlled trials had a Fragility Index of zero and were excluded from further analysis. Linear regression was performed to assess factors associated with Fragility Indexes stratified by primary or secondary outcomes. The median sample size was 134 (range 2211506) with 36 (range 5–2743) total number of events. The median Fragility Index was three (range 1–166), indicating that in half the trials the addition of three events to the treatment with the lowest number of events rendered the result nonsignificant. For primary outcome studies a doubling in total event number and sample size significantly increased the geometric mean Fragility Index by 52% and 42%, respectively. Compared to a reported p value of 0.05 to 0.01, those reporting 0.01 to 0.001 or less than 0.001 had a significant 57% and 472% increase in the median Fragility Index, respectively. Forty-one percent had a Fragility Index less than the total loss to follow-up, indicating a potential to change a trial result had all individuals been accounted for. Thus, our study highlights the need for larger randomized controlled trials with accurate accounting for loss to follow-up to adequately guide evidence-based practice.
The loss of glomerular podocytes is a key event in the progression of chronic kidney disease resulting in proteinuria and declining function. Podocytes are slow cycling cells that are considered ...terminally differentiated. Here we provide the first report of the directed differentiation of induced pluripotent stem (iPS) cells to generate kidney cells with podocyte features. The iPS-derived podocytes share a morphological phenotype analogous with cultured human podocytes. Following 10 days of directed differentiation, iPS podocytes had an up-regulated expression of mRNA and protein localization for podocyte markers including synaptopodin, nephrin and Wilm's tumour protein (WT1), combined with a down-regulation of the stem cell marker OCT3/4. In contrast to human podocytes that become quiescent in culture, iPS-derived cells maintain a proliferative capacity suggestive of a more immature phenotype. The transduction of iPS podocytes with fluorescent labeled-talin that were immunostained with podocin showed a cytoplasmic contractile response to angiotensin II (AII). A permeability assay provided functional evidence of albumin uptake in the cytoplasm of iPS podocytes comparable to human podocytes. Moreover, labeled iPS-derived podocytes were found to integrate into reaggregated metanephric kidney explants where they incorporated into developing glomeruli and co-expressed WT1. This study establishes the differentiation of iPS cells to kidney podocytes that will be useful for screening new treatments, understanding podocyte pathogenesis, and offering possibilities for regenerative medicine.
Myxoma virus (MYXV) is the type species of the Leporipoxviruses, a genus of Chordopoxvirinae, double stranded DNA viruses, whose members infect leporids and squirrels, inducing cutaneous fibromas ...from which virus is mechanically transmitted by biting arthropods. However, in the European rabbit (Oryctolagus cuniculus), MYXV causes the lethal disease myxomatosis. The release of MYXV as a biological control for the wild European rabbit population in Australia, initiated one of the great experiments in evolution. The subsequent coevolution of MYXV and rabbits is a classic example of natural selection acting on virulence as a pathogen adapts to a novel host species. Slightly attenuated mutants of the progenitor virus were more readily transmitted by the mosquito vector because the infected rabbit survived longer, while highly attenuated viruses could be controlled by the rabbit immune response. As a consequence, moderately attenuated viruses came to dominate. This evolution of the virus was accompanied by selection for genetic resistance in the wild rabbit population, which may have created an ongoing co-evolutionary dynamic between resistance and virulence for efficient transmission. This natural experiment was repeated on a continental scale with the release of a separate strain of MYXV in France and its subsequent spread throughout Europe. The selection of attenuated strains of virus and resistant rabbits mirrored the experience in Australia in a very different environment, albeit with somewhat different rates. Genome sequencing of the progenitor virus and the early radiation, as well as those from the 1990s in Australia and Europe, has shown that although MYXV evolved at high rates there was no conserved route to attenuation or back to virulence. In contrast, it seems that these relatively large viral genomes have the flexibility for multiple pathways that converge on a similar phenotype.
Background In the context of clinical research, investigators have historically selected the outcomes that they consider to be important, but these are often discordant with patients’ priorities. ...Efforts to define and report patient-centered outcomes are gaining momentum, though little work has been done in nephrology. We aimed to identify patient and caregiver priorities for outcomes in hemodialysis. Study Design Nominal group technique. Setting & Participants Patients on hemodialysis therapy and their caregivers were purposively sampled from 4 dialysis units in Australia (Sydney and Melbourne) and 7 dialysis units in Canada (Calgary). Methodology Identification and ranking of outcomes. Analytical Approach Mean rank score (of 10) for top 10 outcomes and thematic analysis. Results 82 participants (58 patients, 24 caregivers) aged 24 to 87 (mean, 58.4) years in 12 nominal groups identified 68 outcomes. The 10 top-ranked outcomes were fatigue/energy (mean rank score, 4.5), survival (defined by patients as resilience and coping; 3.7), ability to travel (3.6), dialysis-free time (3.3), impact on family (3.2), ability to work (2.5), sleep (2.3), anxiety/stress (2.1), decrease in blood pressure (2.0), and lack of appetite/taste (1.9). Mortality ranked only 14th and was not regarded as the complement of survival. Caregivers ranked mortality, anxiety, and depression higher than patients, whereas patients ranked ability to work higher. Four themes underpinned their rankings: living well, ability to control outcomes, tangible and experiential relevance, and severity and intrusiveness. Limitations Only English-speaking participants were eligible. Conclusions Although trials in hemodialysis have typically focused on outcomes such as death, adverse events, and biological markers, patients tend to prioritize outcomes that are more relevant to their daily living and well-being. Researchers need to consider interventions that are likely to improve these outcomes and measure and report patient-relevant outcomes in trials, and clinicians may become more patient-orientated by using these outcomes in their clinical encounters.
Mycomya quadrimaculata sp. nov. is described from specimens collected in southeast Australia, Tasmania, and New Zealand. A key and type photographs of known Australian and New Zealand Mycomya species ...are provided. The relative abundance, observed distribution, and morphological affinities of the new species suggests that it is adventive and a recent introduction to New Zealand. Wing characters indicate that the new species is most closely aligned with a subgroup of the Australian Mycomya fauna.
PDF
