Exposure of Aspergillus fumigatus to caspofungin results in the release, and de novo biosynthesis, of gliotoxin.

Caspofungin is a member of the echinocandin class of antifungal agents that inhibit the synthesis of ß 1,3 glucan thus disrupting fungal cell wall structure and function. Exposure of the Aspergillus fumigatus cultures to caspofungin (0.01, 0.1 or 1.0 µg/ml) resulted in a reduction in cell growth, but the production of the epipolythiodioxopiperazine toxin, gliotoxin, was comparable, or greater, in cultures exposed to caspofungin than untreated controls. Exposure of A. fumigatus hyphae to 1.0 µg/ml caspofungin for 4 h resulted in the release of amino acids (P = 0.01), protein (P = 0.002) and gliotoxin (P = 0.02). Cultures of A. fumigatus incubated in the presence of caspofungin for 4 or 24 h demonstrated enhanced gliotoxin release (P = 0.04 and 0.03, respectively) and biosynthesis (P = 0.04 and 0.03, respectively) compared to that by control cultures. The results presented here indicate that exposure of A. fumigatus to caspofungin results in increased cell permeability and an increase in the synthesis and release of gliotoxin. Since gliotoxin has well established immunosuppressive properties it is possible that exposure of A. fumigatus to caspofungin may potentiate the production of this toxin at the site of infection. Elevated gliotoxin biosynthesis may be an attempt by the fungus to restore the redox balance of the cell following exposure to the antifungal agent but the overall effect appears to be enhanced synthesis and release.

A randomized, double-blind, placebo-controlled trial of testosterone gel on body composition and health-related quality-of-life in men with hypogonadal to low-normal levels of serum testosterone and symptoms of androgen deficiency over 6 months with 12 months open-label follow-up.

INTRODUCTION: The clinical significance of low to low-normal testosterone (T) levels in men remains debated. AIM: To analyze the effects of raising serum T on lean body mass (LBM), fat mass (FM), total body mass, and health-related quality-of-life (HRQoL). METHODS: Randomized, double-blind, placebo-controlled study. Men, aged 50-80 years, with serum total T<15 nmol/L and bioavailable T < 6.68 nmol/L, and a Aging Males' Symptoms (AMS) total score >36, received 6 months treatment with transdermal 1% T gel (5-7.5 mg/day; n =183) or placebo gel (n =179), followed by 12 months open-label with T in all. RESULTS: After 6 months, LBM increased in T- treated patients by 1.28 ± 0.15 kg (mean ± SE) and FM decreased by 1.16 ± 0.16 kg, with minor changes with placebo (LBM +0.02 ± 0.10 kg and FM -0.14 ± 0.12 kg; all p < 0.001, T group vs. placebo). Changes were largely similar across subgroups of age, baseline total testosterone, and baseline BMI. Total HRQoL improved compared with placebo (p < 0.05, T group vs. placebo). CONCLUSIONS: Six months 1% T gel improved body composition and HRQoL in symptomatic men with low to low-normal T, with further improvements over the following 12 months.

Mild traumatic brain injury: lessons learned from clinical, sports, and combat concussions.

Over the past forty years, a tremendous amount of information has been gained on the mechanisms and consequences of mild traumatic brain injuries. Using sports as a laboratory to study this phenomenon, a natural recovery curve emerged, along with standards for managing concussions and returning athletes back to play. Although advances have been made in this area, investigation into recovery and return to play continues. With the increase in combat-related traumatic brain injuries in the military setting, lessons learned from sports concussion research are being applied by the Department of Defense to the assessment of blast concussions and return to duty decision making. Concussion management and treatment for military personnel can be complicated by additional combat related stressors not present in the civilian environment. Cognitive behavioral therapy is one of the interventions that has been successful in treating symptoms of postconcussion syndrome. While we are beginning to have an understanding of the impact of multiple concussions and subconcussive blows in the sports world, much is still unknown about the impact of multiple blast injuries.

Galleria mellonella as a model for fungal pathogenicity testing.

Insects are convenient models for assessing the virulence of microbial pathogens or for assessing the -efficacy of antimicrobial drugs and give results comparable to those that can be obtained using mammals. Galleria mellonella larvae are easy to purchase and inoculate and provide results within 48 h. Various parameters may be used to monitor the effect of a pathogen on the insect and, as a consequence, measure its relative virulence. Larval death, changes in immune cells (haemocytes) numbers, or the extent of proliferation of the pathogen within the insect haemocoel are good indicators of virulence and of the insect's immune response. Analysing the humoral immune response also gives insight into the interaction of the pathogen with the insect. Changes in gene expression or the expression of key antimicrobial peptides provide data on this element of the insect's response and, through extrapolation, how the mammalian immune system might respond. G. mellonella larvae, therefore, provide a quick and convenient means of measuring microbial virulence and are a useful alternative to the use of mammals for this type of screening.

Caspofungin primes the immune response of the larvae of Galleria mellonella and induces a non-specific antimicrobial response.

The echinocandins (e.g. caspofungin) function by inhibiting the synthesis of 1,3-ß-glucan in the fungal cell wall. While the potent antifungal activity of caspofungin has been well characterized in mammals, this study investigated the in vivo antifungal effect of caspofungin using larvae of the insect Galleria mellonella. Caspofungin was successful in increasing the survival of larvae that were inoculated with Candida albicans 1 h before the drug was administered, particularly when a concentration of 0.19 µg ml(-1) was used. Pre-injecting larvae with caspofungin also increased their survival when they were inoculated with either Staphylococcus aureus or C. albicans. Caspofungin administration resulted in an increase in the number of circulating immune cells (haemocytes), an increase in the expression of the genes encoding IMPI and transferrin, and an increase in the expression of a number of proteins (identified by liquid chromatography-mass spectrometry) some of which have immune functions. This work indicates that administration of caspofungin can increase the survival of infected G. mellonella larvae, and this is due to the antifungal properties of caspofungin and also to the ability of caspofungin to prime the insect's immune response.

Proteomic analysis of proteins released from growth-arrested Candida albicans following exposure to caspofungin.

The echinocandins (e.g., caspofungin) are a relatively new class of antifungal drugs that function by inhibiting the synthesis of beta-1,3-glucan in the cell wall and thus lead to lysis of the cell. In this work the effect of caspofungin on the release of peptides from non-growing cells of the yeast Candida albicans that had been exposed to the drug was monitored. Exposure to 0.19 mug/ml caspofungin resulted in the release of amino acids from cells and of both small and large molecular weight proteins as demonstrated by 1- and 2-dimensional gel electrophoresis. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-ToF) mass spectrometry was employed to identify a number of escaped peptides that were found to have increased in intensity upon exposure to the drug. A number of wall-associated proteins (e.g., phosphoglycerate kinase) and a number of glycolytic enzymes (phosphoglycerate mutase 1, fructose-bisphosphate aldolase) were identified. Importantly, several released proteins (e.g., pyruvate kinase, enolase 1, phosphoglycerate mutase, glyceraldehydes 3-phosphate dehydrogenase, fructose bisphosphate aldolase and alcohol dehydrogenase 1) are highly immunogenic in nature. The results presented here demonstrate that non-growing C. albicans cells are susceptible to the effect of caspofungin and that the caspofungin-mediated release of proteins from such cells could lead to a stronger immune response in vivo. This report illustrates that, in addition to hampering cell wall synthesis, caspofungin may also interfere with the permeability of the fungal cell wall.

Exposure to caspofungin activates Cap and Hog pathways in Candida albicans.

Caspofungin is a member of the echinocandin group of antifungals and inhibits the activity of beta-glucan synthase thus disrupting cell wall formation and function. While the potent antifungal activity of this agent is well established, this paper analyzed the response of Candida albicans to caspofungin. Exposure of yeast cells to 0.19 microg/ml caspofungin for 1 to 4 h induced nuclear translocation of Cap1p which was confirmed by Western blotting and confocal microscopy. Caspofungin-treated cells demonstrated increased expression of a number of genes associated with the oxidative stress response, including glutathione reductase (GLR1), mitochondrial processing protease (MAS1) and manganese-superoxide dismutase (SOD2) as well as elevated activity of glutathione reductase and superoxide dismutase. Caspofungin treatment also leads to the nuclear localization of Hog1p as visualized by Western blot using anti-phospho-p38 MAPK (Thr180/Tyr182) antibody. This translocation event lead to increased mRNA levels of catalase (CAT1) but not alkyl hydroperoxide reductase (AHP1). The activity of catalase was increased and reached a maximum at 2 h. In addition, pre-exposure of C. albicans to hydrogen peroxide (0.5 mM, 60 min) conferred an increased tolerance to caspofungin. The data presented here highlight the potent antifungal activity of caspofungin and demonstrate that upon exposure to this agent, C. albicans activates the Cap and Hog pathways in an attempt to limit the oxidative and osmotic stresses associated with this drug.

Accountability, responsiveness and quality for clients model of home support: a model for improved home support services to promote aging at home.

As the proportion of older adults increases within the Canadian population, healthcare systems across the country are facing increased demands for home-based services, including home care nursing, rehabilitation, case management, adult day programs, respite, meal programs and home support. Home support is one of the core care services required in the community to enable older adults to remain at home as long as possible. In 2006, Vancouver Community introduced a new home support delivery and performance management model: the Accountability, Responsiveness and Quality for Clients Model of Home Support (ARQ Model) (VCH 2006). The main components of the ARQ Model are an expanded use of "cluster care" along with stable monthly funding for high-density buildings and neighbourhoods; the introduction of specific monthly and quarterly quality performance reporting; and the implementation of performance-based funding for home support. This article discusses the setup of the ARQ model, its ongoing evaluation and results achieved thus far.

Determinants of sexual activity and its relation to cervical cancer risk among South African women.

BACKGROUND: Invasive cervical cancer is the commonest cause of cancer morbidity and mortality in South African women. This study provides information on adult women's sexual activity and cervical cancer risk in South Africa. METHODS: The data were derived from a case-control study of hormonal contraceptives and cervical cancer risk. Information on age of sexual debut and number of lifetime sexual partners was collected from 524 incident cases and 1541 hospital controls. Prevalence ratios and adjusted prevalence ratios were utilised to estimate risk in exposures considered common. Crude and adjusted relative risks were estimated where the outcome was uncommon, using multiple logistic regression analysis. RESULTS: The median age of sexual debut and number of sexual partners was 17 years and 2 respectively. Early sexual debut was associated with lower education, increased number of life time partners and alcohol use. Having a greater number of sexual partners was associated with younger sexual debut, being black, single, higher educational levels and alcohol use. The adjusted odds ratio for sexual debut < 16 years and >/= 4 life-time sexual partners and cervical cancer risk were 1.6 (95% CI 1.2 - 2.2) and 1.7 (95% CI 1.2 - 2.2), respectively. CONCLUSION: Lower socio-economic status, alcohol intake, and being single or black, appear to be determinants of increased sexual activity in South African women. Education had an ambiguous effect. As expected, cervical cancer risk is associated with increased sexual activity. Initiatives to encourage later commencement of sex, and limiting the number of sexual partners would have a favourable impact on risk of cancer of the cervix and other sexually transmitted infections.

Effect of N-chlorotaurine on Aspergillus, with particular reference to destruction of secreted gliotoxin.

The fungistatic and fungicidal activity of N-chlorotaurine (NCT), a long-lived oxidant produced by stimulated neutrophils, was investigated. Physiological concentrations (75-100 microM) of NCT showed clear fungicidal activity against a range of Aspergillus isolates. Moreover, killing by NCT was significantly increased in the presence of ammonium chloride, explained by the formation of monochloramine by halogenation of ammonium. One clinical isolate of Aspergillus fumigatus was characterized for the production of the immunosuppressive agent gliotoxin, and NCT was shown to cause destruction of gliotoxin, possibly via reduction of the disulphide bridge. Because of its endogenous nature and its high antifungal activity, NCT appears to be a good choice for topical treatment of Aspergillus infections, and the results of this study further substantiate its therapeutic efficacy.