Comparative study on the effectiveness of different mosquito traps in arbovirus surveillance with a focus on WNV detection

The selection of the ideal trap for arbovirus surveillance is an issue of primary importance to increase the sensitivity of virus detection and the cost-effectiveness of the entomological surveillance. During the summer 2011, the effectiveness of five types of mosquito traps (CDC gravid trap, CO2(-)baited trap, BG-Sentinel™ and two experimental prototypes) to attract females potentially infected with West Nile virus were assessed. The study was carried out in three natural wetland sites located in the Emilia-Romagna Region (Northern Italy), using a Latin square scheme. Single night collections of adult females were performed and determination of species and physiological state (gravid, nulliparous or parous) was made upon return to the laboratory. The species most frequently collected in the gravid trap was Culex pipiens sl. L., being gravid females the large majority of the individuals. Species diversity was much higher in CO2(-)baited traps, which may therefore enable a more comprehensive description of the vector species composition and their role in arboviruses circulation. Our findings indicate that gravid traps can be a valid tool and should be integrated in the West Nile virus surveillance system in the Emilia-Romagna region, mainly based on collections made with CO2-baited traps.

Correlation between chronological and physiological age of males from their multivariate urinary endogenous steroid profile and prostatic carcinoma-induced deviation

The biosynthesis of endogenous androgenic anabolic steroids (EAAS) in males varies with age. Knowledge of the general urinary EAAS profile's dependence from aging - not reported up to now - may represents a prerequisite for its exploitation in the screening and diagnostic support for several pathologies. Extended urinary EAAS profiles were obtained from healthy and pathological individuals, using a GC-MS method which was fully validated by a stepwise, analyst-independent scheme. Seventeen EAAS and five of their concentration ratios were determined and investigated using multivariate statistical methods. A regression model based on Kernel partial least squares algorithm was built to correlate the chronological age of healthy male individuals with their "physiological age" as determined from their urinary EAAS profile. Strong correlation (R² = 0.75; slope = 0.747) and good prediction ability of the real chronological age was inferred from EAAS data. In contrast, patients with recent diagnosis (not pharmacologically treated) of prostatic carcinoma (PCa) exhibited a comprehensive EAAS profile with strong negative deviation from the model, corresponding a younger predicted age. This result is possibly related to the activation of anomalous steroid biosynthesis induced from PCa. Over a restricted 60-80 years-old population, PLS-discriminant analysis (DA) was used to distinguish healthy subjects from patients with untreated PCa. PLS-DA yielded excellent discrimination (sensitivity and specificity >90%) between healthy and pathological individuals. This proof-of-concept study provides a preliminary evaluation of multivariate DA on wide EAAS profiles as a screening method to distinguish PCa from non-pathological conditions, overcoming the potentially interfering effect of ageing.

What do we mean by "aging"? Questions and perspectives revealed by studies in Drosophila

What is the nature of aging, and how best can we study it? Here, using a series of questions that highlight differing perspectives about the nature of aging, we ask how data from Drosophila melanogaster at the organismal, tissue, cellular, and molecular levels shed light on the complex interactions among the phenotypes associated with aging. Should aging be viewed as an individual's increasing probability of mortality over time or as a progression of physiological states? Are all age-correlated changes in physiology detrimental to vigor or are some compensatory changes that maintain vigor? Why do different age-correlated functions seem to change at different rates in a single individual as it ages? Should aging be considered as a single, integrated process across the scales of biological resolution, from organismal to molecular, or must we consider each level of biological scale as a separate, distinct entity? Viewing aging from these differing perspectives yields distinct but complementary interpretations about the properties and mechanisms of aging and may offer a path through the complexities related to understanding the nature of aging.

Treatment decision-making in chronic lymphocytic leukaemia: Key factors for healthcare professionals. PRELIC study

OBJECTIVE

To explore the preferences of Spanish healthcare professionals (haematologists and hospital pharmacists) for the treatment selection of active Chronic Lymphocytic Leukaemia (CLL) patients at first relapse, condition that mainly afflicts older adults.

METHODS

A discrete choice experiment (DCE) was conducted among haematologists and hospital pharmacists. A literature review and a focus group informed the DCE design. CLL treatment settings were defined by seven attributes: four patient/disease-related attributes (age, functional status, comorbidities, and risk of the disease) and three treatment-related attributes (efficacy [hazard ratio of progression-free survival, HR-PFS], rate of discontinuations due to adverse events and cost). A mixed-logit model was used to determine choice-based preferences. Relative importance (RI) of attributes was calculated and compared between stakeholders. Willingness-to-pay (WTP) was estimated through the DCE. Besides, nine ad-hoc questions were posed, to explore more in depth CLL treatment decision making.

RESULTS

A total of 130 participants (72 haematologists and 58 hospital pharmacists) answered the DCE. All attributes were significant predictors of preferences (p < 0.05) in the multinomial model. Higher RI was obtained for treatment-related attributes: the highest rated being 'cost' (23.8%) followed by 'efficacy' (20.9%). Regarding patient-related attributes, the highest RI was obtained for 'age' (18.1%). No significant differences (p > 0.05) in RI between haematologists and pharmacists were found. WTP for the treatment was higher for younger CLL patients. Ad-hoc questions showed that patient age and functional status influence treatment decisions.

CONCLUSIONS

For healthcare professionals, 'cost' and 'efficacy' (treatment-related attributes) and age (patient-related attribute) are the main factors that determine CLL treatment selection at first relapse. WTP decreases as patient's age increases.

Liver transplantation in Mexican older adults: A comparative single-center study

INTRODUCTION

Liver disease is currently one of the leading causes of death in older adults and the only option deemed curative is liver transplantation. However, it is uncertain whether the successful results obtained in older adults that receive a liver transplant in developed countries can be replicated in developing countries.

AIM

To determine if there are differences in the survival time between older (≥60years) and younger adults that underwent liver transplantation at a university-affiliated tertiary care center in Mexico City.

MATERIALS AND METHODS

A 2-year longitudinal study was conducted. It included 244 participants that were divided into 2groups according to age at the time of transplantation: older adults (≥60years) and younger adults (18-59years). Survival time was defined as the number of days that elapsed between transplantation and death. Survival was expressed as Kaplan-Meier curves.

RESULTS

Median age in the older adults (n=52) was 63.0 (IQR=60-69) and 23 participants were females (44.2%). In the younger adults (n=196) median age was 47.0 (IQR=16-59) and 104 were females (52%). The leading indication for transplant was hepatitisC virus. After the follow-up, fifteen participants died (12 younger adults and 3 older adults). No significant differences were observed between older and younger participants in postoperative complications, the number of re-admissions, or mean post-transplantation survival time.

CONCLUSIONS

There were no statistically significant differences in relation to survival times between older and younger adults that received a liver transplant. Older patients in developing countries should not be excluded from the selection process due only to age.

Multiple physiological cohorts comprise seasonal activity of wild Amblyomma americanum (Acari: Ixodidae) nymphs

Nymphs of the hard tick Amblyomma americanum (L.) are an important life stage in the maintenance and transmission of tick-borne pathogens. As pathogen composition can vary across developmental cohorts, it is essential to understand the demographic structure of the questing population. Amblyomma americanum nymphs often display a second peak in activity during late summer, but it is unknown whether this peak represents older overwintered ticks or younger newly molted ticks. The objective of this study was to examine the heme concentration in field-captured A. americanum nymphs to determine if the questing population consists of one physiological cohort or multiple cohorts in a season. Ticks were collected from March to August in an old field of primarily non-native grasses, and heme concentration was used to assess physiological age. LOESS modeling depicted that heme concentration in the population declined from March to early July but increased in later sampling sessions. As ticks cannot replenish declining heme stores without a blood meal, a late-summer spike in heme concentration demonstrates that newly molted nymphs are entering the active population. The vector potential of these newly emerging nymphs may differ from those collected earlier in the year as pathogen diversity depends on reservoir host dynamics and timing of larval feeding.

Seasonal changes in questing efficiency of wild Amblyomma americanum (Acari: Ixodidae) nymphs

Understanding the factors which influence host-seeking behavior of ticks is essential to determine the risk they pose as a vector of pathogens. While many studies have evaluated the impact of environmental variables on tick behavior, few have examined how seasonal changes in physiological status may further modify patterns of activity. In this study, we measured differences in questing behavior of mid spring- and early summer-caught Amblyomma americanum nymphs held under standardized laboratory conditions. As both groups represent the same cohort of overwintered nymphs, we hypothesized that age-related changes in the older summer ticks may influence questing behavior. In each season, we collected nymphs from field and forest habitats in northeast Missouri, after which we placed each nymph individually in a desiccating vertical questing apparatus with a hydrating microenvironment at the base. On the day following collection, we recorded the height of each nymph in the apparatus bi-hourly from 04:00 to 22:00 and calculated the vertical displacement between consecutive observations. Despite displaying no differences in mean questing height throughout the experiment, active ticks collected in the summer group (n = 89) travelled greater cumulative distances between desiccating and hydrating microenvironments than those collected in the spring (n = 119). This suggests that questing efficiency decreases in summer nymphs to accommodate increased time allocation towards rehydration. While we observed no direct association between body size and distance travelled, body size of the nymphal population also decreased significantly from spring to summer. Overall, our results demonstrate that there are seasonal changes in how A. americanum responds to environmental conditions. To more accurately predict host-seeking behavior of ticks across seasons, models should incorporate physiological parameters of the active ticks in a given population.

Assessment of physiological age and antioxidant status of new somatic hybrid potato seeds during extended cold storage

Yield components of potato are largely affected by the physiology age of the tuber seeds at planting. The current study focuses on monitoring seed tuber aging in two CN1 and CN2 somatic hybrid lines and Spunta (Sp) variety during 270 days of storage at 4 °C. Aging rate was monitored based on sprouting, emergence and tissue oxidation rates. Investigation of sprouting parameters such as physiological age index (PAI) considering physiological and chronological age and the incubation period (IP) indicated lower physiological age in hybrids than in Sp during the storage. Moreover, these analyses showed that off-seasonal growing conditions increased the aging, more clearly, in Sp tubers than in hybrid ones. However, dormancy periods (endodormancy and after storage dormancy) were equivalent in the different tuber lots. PAI and IP data when combined with those from emergence parameters (duration until emergence and stem number) seem more efficient for the characterization of the different potato lines. However, emergence indicators, when considered separately, were not able to distinguish clearly between seasonal and off-seasonal tubers. Data suggest that hybrid seeds exhibited high performances since they produced higher stem number per plant than Sp. The high aging rate in Sp tubers seems to be associated with the few developed stems. Biochemical analyses supported in part morphophysiological differences between hybrids and Sp seeds although these indicators seem more sensitive to aging. Indeed data showed that the dormancy break, and then, the development were associated with some level of tissue oxidation. Antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and carotenoids seem more enhanced after the release of dormancy. However, induction of these activities started earlier in off-seasonal tubers than in seasonal ones, this was consistent with their advanced aging level revealed by PAI and IP data. Activation of these antioxidants appears to respond effectively to the increase of ROS suggesting a better control of postharvest development and tissue deterioration especially in CN2 off-seasonal tubers. This study suggests that CN2 followed by CN1 exhibited the best performance compared to Sp variety.