Batrachochytrium dendrobatidis is a chytrid fungus that causes the lethal skin disease chytridiomycosis in amphibians. It is regarded as an emerging infectious disease affecting diverse amphibian ...populations in many parts of the world. Because there are few model amphibian species for immunological studies, little is known about immune defenses against B. dendrobatidis. We show here that the South African clawed frog, Xenopus laevis, is a suitable model for investigating immunity to this pathogen. After an experimental exposure, a mild infection developed over 20 to 30 days and declined by 45 days postexposure. Either purified antimicrobial peptides or mixtures of peptides in the skin mucus inhibited B. dendrobatidis growth in vitro. Skin peptide secretion was maximally induced by injection of norepinephrine, and this treatment resulted in sustained skin peptide depletion and increased susceptibility to infection. Sublethal X-irradiation of frogs decreased leukocyte numbers in the spleen and resulted in greater susceptibility to infection. Immunization against B. dendrobatidis induced elevated pathogen-specific IgM and IgY serum antibodies. Mucus secretions from X. laevis previously exposed to B. dendrobatidis contained significant amounts of IgM, IgY, and IgX antibodies that bind to B. dendrobatidis. These data strongly suggest that both innate and adaptive immune defenses are involved in the resistance of X. laevis to lethal B. dendrobatidis infections.
The structures of natural products from a variety of sources contain spirocycles, two rings that share a common atom. The spiro motif is finding increasing inclusion in drug candidates, and as a ...structural component in several promising classes of chiral ligands used in asymmetric synthesis. Total syntheses of products containing all-carbon spirocycles feature several common methods of ring closure which we examine in this review.
Objective
To examine the relationship between local food environments and obesity and assess the quality of studies reviewed.
Methods
Systematic keyword searches identified studies from US and Canada ...that assessed the relationship of obesity to local food environments. We applied a quality metric based on design, exposure and outcome measurement, and analysis.
Results
We identified 71 studies representing 65 cohorts. Overall, study quality was low; 60 studies were cross‐sectional. Associations between food outlet availability and obesity were predominantly null. Among non‐null associations, we saw a trend toward inverse associations between supermarket availability and obesity (22 negative, 4 positive, 67 null) and direct associations between fast food and obesity (29 positive, 6 negative, 71 null) in adults. We saw direct associations between fast food availability and obesity in lower income children (12 positive, 7 null). Indices including multiple food outlets were most consistently associated with obesity in adults (18 expected, 1 not expected, 17 null). Limiting to higher quality studies did not affect results.
Conclusions
Despite the large number of studies, we found limited evidence for associations between local food environments and obesity. The predominantly null associations should be interpreted cautiously due to the low quality of available studies.
Cryptococcal infections are an important cause of morbidity and mortality in tropical Australia. This retrospective audit was conducted to characterise the aetiology, temporospatial epidemiology, and ...clinical course of 49 cryptococcal infections in Far North Queensland between 1 January 1999 and 31 December 2019. Cryptococcus gattii was identified in 15/32 (47%) in whom it was possible to speciate the organism. Among these 15 patients, 13 (87%) had a rural residential address, 10 (67%) were Indigenous Australians and 11 (73%) presented during the May-November dry season. When compared to the 17 patients with Cryptococcus neoformans infection, patients with C. gattii were less likely to be immunocompromised (0/15 versus 8/17 (47%), p = 0.003). Neurosurgery was necessary in 5/15 C. gattii cases and 3/17 (18%) C. neoformans cases (p = 0.42). Outcomes were generally good with 42/49 (86%) cases-and 14/15 (93%) with C. gattii infection-surviving to hospital discharge. These positive outcomes are likely to be explained by the development of standardised treatment guidelines during the study period, low rates of comorbidity in the patients with C. gattii infection and access to liposomal amphotericin and neurosurgical support in the well-resourced Australian healthcare system.
To define the microbiologic characteristics of animal bites in tropical Australia and the appropriateness of current Australian antimicrobial guidelines for their management.
This retrospective audit ...examined hospitalizations in tropical Australia after an animal bite or animal-associated penetrating injury between 2013 and 2020. The primary outcome was a composite of death, intensive care unit admission, amputation, quaternary center transfer, or unplanned rehospitalization.
A wide variety of animals were implicated, but snakes (734/1745, 42%), dogs (508/1745, 29%), and cats (153/1745, 9%) were the most common. Hospital presentation after 24 hours (odds ratio (OR) (95% confidence interval (CI)): 68.67 (42.10-112.01)) and a cat-related injury (OR (95% CI): 22.20 (11.18-44.08)) were independently associated with an increased risk of infection. A pathogen not covered by the relevant antimicrobial regimen recommended in Australian guidelines was identified in only 12/1745 (0.7%) cases. The primary outcome occurred in 107/1745 (6%) and was independently associated with tissue trauma (OR (95% CI): 9.29 (6.05-14.25), p<0.001), established deep infection at presentation (OR (95% CI): 2.95 (1.31-6.61), p=0.009) and hospital presentation after 24 hours (OR (95% CI): 1.77 (1.12-2.79), p=0.01).
A wide variety of animals bite humans in tropical Australia, but empiric antimicrobial regimens recommended in current national guidelines cover almost all the microbiologic isolates from the resulting wounds.
Language data available through social media provide opportunities to study people at an unprecedented scale. However, little guidance is available to psychologists who want to enter this area of ...research. Drawing on tools and techniques developed in natural language processing, we first introduce psychologists to social media language research, identifying descriptive and predictive analyses that language data allow. Second, we describe how raw language data can be accessed and quantified for inclusion in subsequent analyses, exploring personality as expressed on Facebook to illustrate. Third, we highlight challenges and issues to be considered, including accessing and processing the data, interpreting effects, and ethical issues. Social media has become a valuable part of social life, and there is much we can learn by bringing together the tools of computer science with the theories and insights of psychology.
Eating disorders are serious, potentially life-threatening illnesses afflicting individuals through the life span, with a particular impact on both the physical and psychological development of ...children and adolescents. Because care for children and adolescents with eating disorders can be complex and resources for the treatment of eating disorders are often limited, pediatricians may be called on to not only provide medical supervision for their patients with diagnosed eating disorders but also coordinate care and advocate for appropriate services. This clinical report includes a review of common eating disorders diagnosed in children and adolescents, outlines the medical evaluation of patients suspected of having an eating disorder, presents an overview of treatment strategies, and highlights opportunities for advocacy.
The advances made in chemistry during the last 70 years are excellently illustrated by the development of the industrial synthesis of vitamin A, a diterpene crucial in preventing premature death and ...visual problems. Arens and van Dorp published the first route in 1946, and critical contributions have been made by a number of scientists since, benefitting from fruitful collaborations between industry and academia. However, these improvements have been mostly incremental, and the work has been performed by a limited number of companies; as yet, there is still no ‘ideal’ synthesis of vitamin A.
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