Biotests and biosensors in ecotoxicological risk assessment of field soils polluted with zinc, lead, and cadmium

The combined chemical and ecotoxicological hazard evaluation study was conducted on 60 smelter-influenced soils containing 1 to 13, 50 to 653, and 100 to 1,198 mg/kg of Cd, Pb, and Zn, respectively. For these soils (liquid-to-soil ratio = 10), water extractability of Zn, Cd, and Pb was less than 0.19% (median values). Acetic acid (0.11 M) extracted 23, 9.7, and 0.7% of Cd, Zn, and Pb, respectively. Although heavy metal concentrations in the studied soils were high, the toxic effects of water extracts were observed only in few samples and in few biotests (algae Selenastrum capricornutum and metal detector assay). For most of the aquatic test organisms (e.g., crustaceans, photobacteria), the bioavailable concentrations of metals in soil-water extracts were either subtoxic, or the adverse effects were compensated by soil nutrients, etc. However, analysis of the soils with recombinant Cd sensor Bacillus subtilis (pTOO24) showed that about 65% of these apparently subtoxic samples contained bioavailable Cd when analyzed in the suspension assay (detection limit 1.5 mg Cd/kg soil), indicating the desorption of Cd induced by direct contact of bacteria with soil particles. The median bioavailable fraction of Cd (1%) was 23-fold lower than the fraction extracted by acetic acid. The Pb-Cd sensor Staphylococcus aureus (pT0024) detected bioavailable Pb only in the suspensions of five of the most lead-polluted soils (>417 mg Pb/kg): the median bioavailability of Pb was 0.42%. Consequently, the hazard assessment relying on total metal levels in soils should be revised by critical comparison with data obtained from bioassays. Development and use of biosensors (excellent tools for mechanistic studies and signaling hazard already at subtoxic level) should be encouraged.     

African Swine Fever Re-Emerging in Estonia: The Role of Seropositive Wild Boar from an Epidemiological Perspective

African swine fever (ASF) emerged in Estonia in 2014. From February 2019 to August 2020, no pigs or wild boar tested positive for ASF virus (ASFV), only ASFV-specific antibodies could be detected in shot wild boar. However, ASF recently re-emerged in wild boar. We tested three hypotheses that might explain the current situation: (i) ASFV may have been present throughout, but at a prevalence below the detection limit; (ii) seropositive wild boar may have remained infectious (i.e., virus-carriers) and kept the epidemic going; or (iii) ASF was gone for 1.5 years, but was recently re-introduced. Using Estonian surveillance data, the sensitivity of the surveillance system and the confidence in freedom from ASF were estimated. Furthermore, the detection probability was determined and cluster analyses were performed to investigate the role of serological positive wild boar. The results suggest that the surveillance system was not able to detect virus circulation at a design prevalence below 1%. With respect to the confidence in freedom from ASF, the results indicate that circulating virus should have been detected over time, if the prevalence was ≥2%. However, the decreasing wild boar population density and ongoing surveillance activities made ASFV circulation at a low prevalence unlikely. Cluster analyses provided no evidence for a significant accumulation of serologically positive wild boar in temporal connection to the re-emergence of ASFV. Further targeted research, such as long-term experimental studies and molecular epidemiology, is necessary to improve our knowledge on the epidemiology of ASF and to control the disease more effectively.     

Developing the “Upstreamist” through Antiracism Teaching in Pharmacy Education

Objective. To present antiracism teaching as a key modality and an upstream approach to addressing health disparities in pharmacy education. Relevant theoretical frameworks and pedagogical strategies used in other health disciplines will be reviewed to present how antiracism curricula can be integrated into pharmacy educational outcomes.Findings. Various disciplines have incorporated antiracism pedagogy in their respective programs and accreditation standards. While challenges to implementation are acknowledged, structural racism continues to compromise health outcomes and should be centralized when addressing health disparities.Summary. Pharmacy curricula has explored and implemented cultural competency as a means to address the social determinants of health. By intentionally addressing racism in the context of health disparities, student pharmacists will further acknowledge racism as a public health issue and a systemic barrier to patient-centered care.     

Toxicity testing of heavy-metal-polluted soils with algae Selenastrum capricornutum: a soil suspension assay

A small-scale Selenastrum capricornutum (Rhapidocelis subcapitata) growth inhibition assay was applied to the toxicity testing of suspensions of heavy-metal-polluted soils. The OECD 201 standard test procedure was followed, and algal biomass was measured by the fluorescence of extracted chlorophyll. The soils, which contained up to (per kilogram) 1390 mg of Zn, 20 mg of Cd, and 1050 mg of Pb were sampled around lead and zinc smelters in northern France. The water extractability of the metals in suspensions (1 part soil/99 parts water w/v) was not proportional to the pollution level, as extractability was lower for soil samples that were more polluted. Thus, the same amount of metals could be leached out of soils of different levels of pollution, showing that total concentrations of heavy metals in soil (currently used for risk assessment purposes) are poor predictors of the real environmental risk via the soil-water path. Despite high concentrations of water-extracted zinc (0.6-1.4 mg/L of Zn in the test), exceeding by approximately 10-fold the EC(50) value for S. capricornutum (0.1 mg Zn/L), 72-h algal growth in the soil extracts was comparable or better than growth in the standard control OECD mineral medium. The soil suspension stimulated the growth of algae up to eightfold greater than growth using the OECD control medium. Growth stimulation of algae was observed even when soil suspensions contained up to 12.5 mg Zn/L and could not be explained by supplementary nitrogen, phosphorous, and carbonate leached from the soil. However, if the growth of algae in suspensions of clean and polluted soils was compared, a dose-dependent inhibitory effect of metals on algal growth was demonstrated. Thus, as soil contains nutrients/supplements that mask the adverse effect of heavy metals, a clean soil that has properties similar to the polluted soils should be used instead of mineral salt solution as a control for analysis of the ecotoxicity of soils.     

IL‐22 neutralizing autoantibodies impair fungal clearance in murine oropharyngeal candidiasis model

Protection against mucocutaneous candidiasis depends on the T helper (Th)17 pathway, as gene defects affecting its integrity result in inability to clear Candida albicans infection on body surfaces. Moreover, autoantibodies neutralizing Th17 cytokines have been related to chronic candidiasis in a rare inherited disorder called autoimmune polyendocriopathy candidiasis ectodermal dystrophy (APECED) caused by mutations in autoimmune regulator (AIRE) gene. However, the direct pathogenicity of these autoantibodies has not yet been addressed. Here we show that the level of anti‐IL17A autoantibodies that develop in aged Aire‐deficient mice is not sufficient for conferring susceptibility to oropharyngeal candidiasis. However, patient‐derived monoclonal antibodies that cross‐react with murine IL‐22 increase the fungal burden on C. albicans infected mucosa. Nevertheless, the lack of macroscopically evident infectious pathology on the oral mucosa of infected mice suggests that additional susceptibility factors are needed to precipitate a clinical disease.     

Quantification of Clostridium difficile in antibiotic-associated-diarrhea patients

Comparing culture- and non-culture-based methods for quantifying Clostridium difficile in antibiotic-associated-diarrhea patients, we found that the real-time PCR method correlated well with quantitative culture and was more sensitive. A positive association between the population levels of C. difficile and the presence of its toxins was found.     

A phase III comparison of two toremifene doses to tamoxifen in postmenopausal women with advanced breast cancer

Efficacy and safety of toremifene 60 and 240mg daily (TOR60 and TOR240) are compared to40 mg tamoxifen daily (TAM40) in postmenopausal womenwith advanced estrogen receptor (ER) positive or ERunknown breast cancer. The study is randomized andopen label in three parallel groups. Primary efficacyvariables are response rate and time to progression.WHO and ECOG criteria were used for measurableand nonmeasurable disease assessment, respectively. Safety was reportedaccording to WHO criteria. Altogether 463 patients wererandomized (157 to TOR60, 157 to TOR240, and149 to TAM40). By data cut-off, after 20.5months median follow-up time, over 70% of thepatients had experienced disease progression. Response rates are20.4%, 28.7%, and 20.8% in TOR60, TOR240, andTAM40, respectively. TOR60 and TAM40 show statistically equivalentefficacy and the difference between TOR240 and TAM40is not significant (P=0.112). Median timesto progression are 4.9 (TOR60), 6.1 (TOR240), and5.0 (TAM40) months and the corresponding hazard ratios(TAM:TOR) 1.015 and 1.124. Again, TOR60 and TAM40are statistically equivalent and the difference between TOR240and TAM40 is not significant (P=0.374).All treatments were well tolerated. As a conclusion,TOR60 and TAM40 show equivalent clinical efficacy andtolerability. The higher dose of toremifene slightly butnot statistically significantly improves response rate and timeto progression. In postmenopausal women, toremifene 60 mgdaily is an effective and safe treatment ofadvanced ER-positive or ER-unknown breast cancer.     

To sample or not to sample? Detection of African swine fever in wild boar killed in road traffic accidents

African swine fever (ASF) in wild boar remains a threat for the global pig industry. Therefore, surveillance is of utmost importance, not only to control the disease but also to detect new introductions as early as possible. Passive surveillance is regarded as the method of choice for an effective detection of ASF in wild boar populations. However, the relevance of wild boar killed through road traffic accidents (RTA) for passive surveillance seems to be unclear. Using comprehensive ASF wild boar surveillance data from Estonia and Latvia, the prevalence of ASF‐infected wild boar was calculated and the probability of infection as measured by PCR compared for animals that were hunted, found dead, shot sick or killed in a RTA. The number of samples originating from wild boar killed in a RTA was low and so was the ASF prevalence in these animals. However, the reasons for this low number of RTA animals remain unknown. Therefore, we recommend to sample wild boar killed in a RTA to a greater extent, also to explore, if this approach can increase the detection probability, and to avoid missing disease introduction.