The impact of disclosure of conflicts of interest in studies comparing robot-assisted and laparoscopic cholecystectomies-a persistent problem.

INTRODUCTION: Accurate disclosure of conflicts of interest (COI) is critical to interpretation of study results, especially when industry interests are involved. We reviewed published manuscripts comparing robot-assisted cholecystectomy (RAC) and laparoscopic cholecystectomy (LC) to evaluate the relationship between COI disclosures and conclusions drawn on the procedure benefits and safety profile. METHODS: Searching Pubmed and Embase using key words "cholecystectomy", laparoscopic" and "robotic"/"robot-assisted" retrieved 345 publications. Manuscripts that compared benefits and safety of RAC over LC, had at least one US author and were published between 2014 and 2020 enabling verification of disclosures with reported industry payments in CMS's Open Payments database (OPD) (up to 1 calendar year prior to publication) were included in the analysis (n = 37). RESULTS: Overall, 26 (70%) manuscripts concluded that RAC was equivalent or better than LC (RAC +) and 11 (30%) concluded that RAC was inferior to LC (RAC-). Six manuscripts (5 RAC + and 1 RAC-) did not have clearly stated COI disclosures. Among those that had disclosure statements, authors' disclosures matched OPD records among 17 (81%) of RAC + and 9 (90%) RAC- papers. All 11 RAC- and 17 RAC + (65%) manuscripts were based on retrospective cohort studies. The remaining RAC + papers were based on case studies/series (n = 4), literature review (n = 4) and clinical trial (n = 1). A higher proportion of RAC + (85% vs 45% RAC-) manuscripts used data from a single institution. Authors on RAC + papers received higher amounts of industry payments on average compared to RAC- papers. CONCLUSIONS: It is imperative for authors to understand and accurately disclose their COI while disseminating scientific output. Journals have the responsibility to use a publicly available resource like the OPD to verify authors' disclosures prior to publication to protect the process of scientific authorship which is the foundation of modern surgical care.

The influence of infection status and parasitism risk on host dispersal and susceptibility to infection in Drosophila nigrospiracula.

For many organisms, habitat avoidance provides the first line of defence against parasitic infection. Changes in infection status can shift the cost-benefit ratio of remaining in a given habitat vs dispersing. The aim of this study was to test the hypothesis that the propensity to disperse in Drosophila nigrospiracula is mediated by current parasite load and the risk of further infection by an ectoparasitic mite (Macrocheles subbadius). An activity monitor was used to assess dispersal propensity among infected and uninfected flies. The activity level of uninfected females increased threefold upon exposure to a mite, whereas the activity among uninfected males increased by 17-fold in the presence of a questing mite. Among infected flies, the risk of further infection also generated a change in activity, but the magnitude of the response was dependent on host sex. Current infection status influenced the probability of acquiring more parasites due to increased susceptibility to infection with mite load. The probability of acquiring additional mites among males increased more rapidly compared to female flies. Current infection status can potentially determine the risk of further infection, the host propensity and ability to disperse, with consequence for hosts and parasites at the individual, population and species level.

State-dependent parasitism by a facultative parasite of fruit flies.

Parasites can evolve phenotypically plastic strategies for transmission such that a single genotype can give rise to a range of phenotypes depending on the environmental condition. State-dependent plasticity in particular can arise from individual differences in the parasite's internal state or the condition of the host. Facultative parasites serve as ideal model systems for investigating state-dependent plasticity because individuals can exhibit two life history strategies (free-living or parasitic) depending on the environment. Here, we experimentally show that the ectoparasitic mite Macrocheles subbadius is more likely to parasitize a fruit fly host if the female mite is mated; furthermore, the propensity to infect increased with the level of starvation experienced by the mite. Host condition also played an important role; hosts infected with moderate mite loads were more likely to gain additional infections in pairwise choice tests than uninfected flies. We also found that mites preferentially infected flies subjected to mechanical injury over uninjured flies. These results suggest that a facultative parasite's propensity to infect a host (i.e. switch from a free-living strategy) depends on both the parasite's internal state and host condition. Parasites often live in highly variable and changing environments, an infection strategy that is plastic is likely to be adaptive.

Mitey Costly: Energetic Costs of Parasite Avoidance and Infection.

Parasites reduce host fitness via perturbations to host energy allocation, growth, survival, and reproduction. Here, we investigate the independent effects of parasite exposure and infection on host metabolic rate. Our study focuses on Drosophila hydei and a naturally occurring ectoparasitic mite, Macrocheles muscaedomesticae. We use flow-through respirometry to measure the metabolic rate of flies during the period of exposure (preinfection) and during mite attachment. Flies were exposed to mites either indirectly (through a mesh screen) or directly, allowing for physical contact between the fly and the mite. We predicted that fly metabolic rate would increase with the level of parasite exposure: unexposed flies < flies with indirect exposure to mites < flies with direct contact with mites < flies actively infected with mites. As expected, flies indirectly exposed to but not in direct contact with mites produced 70% more CO2 than unexposed flies. Flies in direct contact with mites produced 35% more CO2 than flies with indirect contact, and this was more than double the amount of CO2 produced by unexposed flies. However, infected flies-those actually carrying mites-did not produce significantly more CO2 than uninfected flies. Our results show that simply being exposed to mites, either indirectly or directly, was sufficient to elicit a response from the host in terms of elevated CO2 production. Our results show that the costs of parasitism can potentially extend beyond the physiological costs of infection per se to include the energetic costs associated with parasite avoidance. Although studies have shown energetic costs associate with predator-avoidance behaviors, no study to our knowledge has measured the metabolic cost of parasite avoidance.