Project description:Preclinical and clinical studies provide evidence for aspirin as a preventative agent for cancer. Compelling direct evidence supports a chemopreventive effect of aspirin in individuals at high risk of developing colorectal cancer due to Lynch syndrome, while indirect evidence indicates that aspirin may reduce the risk of and mortality from sporadic colorectal cancer. There is weaker evidence for a protective effect of aspirin against all cancers taken as a group. Nevertheless, the results of recent retrospective cohort studies consistently indicate a beneficial effect of aspirin as a chemopreventive or adjuvant chemotherapeutic agent in hepatocellular carcinoma (HCC). Epidemiologic studies conducted in the general population or in selected populations at higher risk for HCC reveal that regular aspirin use is associated with reduced HCC incidence. In addition, aspirin may act as an adjuvant to other therapies in reducing HCC recurrence. According to studies in animal models, the cancer-preventative effect of aspirin may be related to its antiplatelet and anti-inflammatory activities. Prospective studies are warranted to determine whether aspirin should be recommended to diverse populations of patients at risk for HCC.
Project description:Approximately 20% of sleeping sickness patients exhibit respiratory complications which are commonly attributed to secondary bacterial infections, with an unknown role of the parasite. Using a Glossina morsitans tsetse fly initiated Trypansoma brucei infection in mice we found that parasites rapidly and permanently colonize the lungs, representing one of the major target organs next to the adipose tissue. Trypanosomes were found by immunofluorescence staining and scanning electron microscopy to occupy the extravascular spaces surrounding the blood vessels of the alveoli and bronchi. Parasites were even found in the lung cartilage. Trypanosomes were often observed as nests of multiplying parasites exhibiting close interactions with collagen and highly active secretion of extracellular vesicles that are engaged in intercellular communication. The local immune response was analysed by flow cytometry after 10 and 21 days of infection and was characterized by a substantial increase of CD11b+ Ly6C+ monocytes, CD11b+ Ly6C+ F4/80+ macrophages and CD11b+ CD11c+ dendritic cells. CD11b+ Ly6G+ neutrophils only accumulated prominently at the late infection time point. Interestingly, parasite presence resulted in a significant reduction of B220+ IgM+ B cells, CD11b+ CD11clo/- SiglecF+ eosinophils and TcR-β- NK1.1+ natural killer cells. Digital transcriptomics revealed infection-induced upregulation of Il-10, IFN-ɣ- and IFN-α-responses, IL-2-, IL-6- and TNF-signalling, a Th1 pro-inflammatory signature, negative immune checkpoint regulators and a predominant M1 macrophage polarization. Il12a and genes associated with complement and the B cell receptor were downregulated. No infection-associated pulmonary dysfunction could be detected by in vivo lung function measurements, mirroring the limited pulmonary complications during sleeping sickness. However, the substantial reduction of eosinophils, B cells and NK cells may render individuals more susceptible to opportunistic infections. Collectively, these observations provide essential insights in the peculiar parasite biology, immunological reactions and physiological function of a largely overlooked target organ which may trigger new diagnostic approaches for sleeping sickness.
Project description:ImportanceProspective data on the risk of hepatocellular carcinoma (HCC) according to dose and duration of aspirin therapy are limited.ObjectiveTo examine the potential benefits of aspirin use for primary HCC prevention at a range of doses and durations of use within 2 prospective, nationwide populations.Design, setting, and participantsPooled analysis of 2 prospective US cohort studies: the Nurses' Health Study and the Health Professionals Follow-up Study. Data were accessed from November 1, 2017, through March 7, 2018. A total of 133 371 health care professionals who reported data on aspirin use, frequency, dosage, and duration of use biennially since 1980 in women and 1986 in men were included. Individuals with a cancer diagnosis at baseline (except nonmelanoma skin cancer) were excluded.Main outcomes and measuresCox proportional hazards regression models were used to calculate multivariable adjusted hazard ratios (HRs) and 95% CIs for HCC.ResultsOf the 133 371 participants, 87 507 were women and 45 864 were men; in 1996, the median time of follow-up, the mean (SD) age was 62 (8) years for women and 64 (8) years for men. Over more than 26 years of follow-up encompassing 4 232 188 person-years, 108 incident HCC cases (65 women, 43 men) were documented. Compared with nonregular use, regular aspirin use (≥2 standard-dose [325-mg] tablets per week) was associated with reduced HCC risk (adjusted HR, 0.51; 95% CI, 0.34-0.77). This benefit appeared to be dose related: compared with nonuse, the multivariable-adjusted HR for HCC was 0.87 (95% CI, 0.51-1.48) for up to 1.5 standard-dose tablets per week, 0.51 (95% CI, 0.30-0.86) for more than 1.5 to 5 tablets per week, and 0.49 (95% CI, 0.28-0.96) for more than 5 tablets per week (P for trend = .006). Significantly lower HCC risk was observed with increasing duration (P for trend = .03); this decrease was apparent with use of 1.5 or more standard-dose aspirin tablets per week for 5 or more years (adjusted HR, 0.41; 95% CI, 0.21-0.77). In contrast, use of nonaspirin nonsteroidal anti-inflammatory drugs was not significantly associated with HCC risk (adjusted HR, 1.09; 95% CI, 0.78-1.51).Conclusions and relevanceThis study suggests that regular, long-term aspirin use is associated with a dose-dependent reduction in HCC risk, which is apparent after 5 or more years of use. Similar associations were not found with nonaspirin NSAIDs. Further research appears to be needed to clarify whether aspirin use represents a feasible strategy for primary prevention against HCC.
Project description:BackgroundMore information is needed about the long-term effects of low-dose aspirin (≤160 mg) on incident hepatocellular carcinoma, liver-related mortality, and gastrointestinal bleeding in persons with chronic hepatitis B or hepatitis C virus infection.MethodsUsing nationwide Swedish registries, we identified all adults who received a diagnosis of chronic hepatitis B or hepatitis C from 2005 through 2015 and who did not have a history of aspirin use (50,275 patients). Patients who were starting to take low-dose aspirin (14,205 patients) were identified by their first filled prescriptions for 90 or more consecutive doses of aspirin. We constructed a propensity score and applied inverse probability of treatment weighting to balance baseline characteristics between groups. Using Cox proportional-hazards regression modeling, we estimated the risk of hepatocellular carcinoma and liver-related mortality, accounting for competing events.ResultsWith a median of 7.9 years of follow-up, the estimated cumulative incidence of hepatocellular carcinoma was 4.0% among aspirin users and 8.3% among nonusers of aspirin (difference, -4.3 percentage points; 95% confidence interval [CI], -5.0 to -3.6; adjusted hazard ratio, 0.69; 95% CI, 0.62 to 0.76). This inverse association appeared to be duration-dependent; as compared with short-term use (3 months to <1 year), the adjusted hazard ratios were 0.90 (95% CI, 0.76 to 1.06) for 1 to less than 3 years of use, 0.66 (95% CI, 0.56 to 0.78) for 3 to less than 5 years of use, and 0.57 (95% CI, 0.42 to 0.70) for 5 or more years of use. Ten-year liver-related mortality was 11.0% among aspirin users and 17.9% among nonusers (difference, -6.9 percentage points [95% CI, -8.1 to -5.7]; adjusted hazard ratio, 0.73 [95% CI, 0.67 to 0.81]). However, the 10-year risk of gastrointestinal bleeding did not differ significantly between users and nonusers of aspirin (7.8% and 6.9%, respectively; difference, 0.9 percentage points; 95% CI, -0.6 to 2.4).ConclusionsIn a nationwide study of patients with chronic viral hepatitis in Sweden, use of low-dose aspirin was associated with a significantly lower risk of hepatocellular carcinoma and lower liver-related mortality than no use of aspirin, without a significantly higher risk of gastrointestinal bleeding. (Funded by the National Institutes of Health and others.).
Project description:BackgroundEmerging data suggest that statins, aspirin and metformin may protect against hepatocellular carcinoma (HCC) development. However, prior meta-analyses were limited by heterogeneity and inclusion of studies without adequate adjustment for baseline risks.AimTo examine by an updated meta-analysis the association between these medications and HCC risk.MethodsMedline and Embase databases were searched from inception to March 2022 for studies that balanced baseline risks between study groups via propensity score matching or inverse probability of treatment weighting, that reported the impact of statins, aspirin or metformin on HCC risk. Multivariable-adjusted hazard ratios (HRs) for HCC were pooled using a random effects model.ResultsStatin use was associated with reduced HCC risk overall (HR: 0.52; 95% CI: 0.37-0.72) (10 studies, 1,774,476), and in subgroup analyses for cirrhosis, hepatitis B/C, non-alcoholic fatty liver disease, studies accounting for concurrent aspirin and metformin consumption and lipophilic statins. Aspirin use was associated with reduced HCC risk overall (HR: 0.48; 95% CI: 0.27-0.87) (11 studies, 2,190,285 patients) but not in studies accounting for concurrent statin and metformin use. Metformin use was not associated with reduced HCC risk overall (HR: 0.57; 95% CI: 0.31-1.06) (3 studies, 125,458 patients). Most analyses had moderate/substantial heterogeneity, except in follow-up <60 months for aspirin (I2 = 0%).ConclusionAlthough statin and aspirin use were associated with reduced HCC risk, only statin use was significant in subgroup analyses accounting for concurrent medications. Metformin use was not associated with reduced HCC risk. These data have implications for future clinical trial design.
Project description:Within the last decade, vitamin D has emerged as a central regulator of host defense against infections. In this regard, vitamin D triggers effective antimicrobial pathways against bacterial, fungal and viral pathogens in cells of the human innate immune system. However, vitamin D also mediates potent tolerogenic effects: it is generally believed that vitamin D attenuates inflammation and acquired immunity, and thus potentially limits collateral tissue damage. Nevertheless, several studies indicate that vitamin D promotes aspects of acquired host defense. Clinically, vitamin D deficiency has been associated with an increased risk for various infectious diseases in epidemiological studies; yet, robust data from controlled trials investigating the use of vitamin D as a preventive or therapeutic agent are missing. In this review, we summarize the current knowledge regarding the effect of vitamin D on innate and acquired host defense, and speculate on the difficulties to translate the available molecular medicine data into practical therapeutic or preventive recommendations.
Project description:Exercise and increased physical activity are vital components of the standard treatment guidelines for many chronic diseases such as diabetes, obesity and cardiovascular disease. Although strenuous exercise cannot be recommended to people with numerous chronic conditions, walking is something most people can perform. In comparison to high-intensity training, the metabolic consequences of low-intensity walking have been less well studied. We present here a feasibility study of a subject who performed an exercise intervention of low-intensity, non-fatiguing walking on a deskmill/treadmill for 200 min daily, approximately the average time a German spends watching television per day. This low-impact physical activity has the advantages that it can be done while performing other tasks such as reading or watching TV, and it can be recommended to obese patients or patients with heart disease. We find that this intervention led to substantial weight loss, comparable to that of bariatric surgery. To study the metabolic changes caused by this intervention, we performed an in-depth metabolomic profiling of the blood both directly after walking to assess the acute changes, as well as 1.5 days after physical activity to identify the long-term effects that persist. We find changes in acylcarnitine levels suggesting that walking activates fatty acid beta oxidation, and that this mitochondrial reprogramming is still visible 1.5 days post-walking. We also find that walking mildly increases gut permeability, leading to increased exposure of the blood to metabolites from the gut microbiome. Overall, these data provide a starting point for designing future intervention studies with larger cohorts.