Differential effects of antidepressant sertraline in glochidia-fish interactions involving drug transfer from parasite to host.

This study examined the impact of sertraline, an antidepressant common in treated wastewater, on the host-parasite dynamics between parasitic freshwater mussel (Unio tumidus, Unionidae) larvae (glochidia) and their host fish (Squalius cephalus, Cyprinidae). Employing a full-factorial design, both fish and glochidia were subjected to sertraline at the combinations of 0 µg L-1 (control), 0.2 µg L-1 (environmentally relevant concentration), and 4 µg L-1 (elevated concentration, short-term exposure of the parasite). The results showed that long-term host exposure (involving intensive sertraline accumulation in the fish brain) marginally increased subsequent glochidia attachment success by 2 %, while parasite exposure at the same environmentally relevant concentrations had no detectable effect. There was also no effect of exposure of glochidia to 0.2 µg L-1 of sertraline on their viability and encapsulation success during the initial parasitic stage. However, a significant alteration in attachment behavior, marked by a 3.3 % increase in attachment success and changes in the glochidia spatial distribution on the host body, was noted after 24 h of glochidia exposure to 4 µg L-1 of sertraline. Importantly, this study provides the first evidence of sertraline transfer from exposed glochidia to nonexposed host fish, as indicated by elevated levels of sertraline (12.8 ng g-1) in the brain tissue of nonexposed hosts. These findings highlight the subtle yet significant effects of pharmaceutical pollutants on freshwater ecosystems but also underscore the importance of understanding the unexpected dynamics of such contamination to predict and address future ecological changes.

Effects of a theory of planned behavior-based intervention on breastfeeding behaviors after cesarean section: A randomized controlled trial.

OBJECTIVES: To examine the efficacy of an intervention based on the theory of planned behavior (TPB) in improving breastfeeding behavior among women with cesarean sections (C-sections). METHODS: This research was a randomized controlled trial. Women with planned elective C-sections were recruited to participate in a randomized controlled trial between June and September 2020. One hundred thirty-two women were divided randomly into the intervention (n = 66) and control group (n = 66) by systematic random sampling. In the intervention group, an intervention project was implemented after the C-section to establish positive breastfeeding attitudes, cultivate supportive subjective norms, enhance perceived behavioral control, and strengthen breastfeeding intention to change behaviors. Those in the control group received routine pre-and post-delivery care. Exclusive breastfeeding rate and breast problem were collected at 5 days, 2 weeks, and 1 month after C-section. The modified Breastfeeding Attrition Prediction Tool (BAPT) on the first day in the hospital, two weeks, and one month after C-section and Numerical Rating Scale (NRS) 24 h postoperatively were used to compare the intervention effect between the two groups. RESULTS: After the intervention, the intervention group had significantly higher exclusive breastfeeding rates than the control group at five days (86.4% vs. 60.6%), two weeks (77.3% vs. 57.6%), and one month (74.2% vs. 50.0%) after the C-section. Besides, the intervention group was less likely to have sore nipples at five days (6.1% vs. 18.2% in the control group, P < 0.05) and two weeks (9.1% vs. 12.1% in the control group, P < 0.05). After two weeks of intervention, attitude scores (90.64 ± 8.31 vs. 87.20 ± 8.15, P < 0.05), subjective norm scores (88.07 ± 24.65 vs. 79.42 ± 19.47, P < 0.05）and behavior control scores in the intervention group were significantly higher than those in the control group. After one month of intervention, attitude scores (90.34 ± 10.35 vs. 84.22 ± 10.51, P < 0.05) and behavior control scores (43.13 ± 5.02 vs. 39.15 ± 4.69, P < 0.05）in the intervention group were significantly higher than those in the control group, which resulted in the higher breastfeeding intention in the intervention group. CONCLUSION: This study indicated that the TPB-based interventions effectively improved women's breastfeeding behaviors after C-sections.

Host-parasite interaction as a toxicity test endpoint using asymmetrical exposures.

Interspecific relationships frequently determine the effect a pollutant can have on an organism, and this is especially true in closely interacting species such as hosts and parasites. The high spatial and temporal variability of contaminant concentrations combined with the movement of aquatic biota can further influence the consequences that are associated with contamination. We used a full factorial design for the exposed and unexposed partners of the relationship between the parasitic larvae (glochidia) of the European freshwater mussel (Anodonta anatina) and its host fish (Squalius cephalus) to identify the sources of variation in the sublethal endpoints of species interaction (the intensity of parasite attachment, the spatial position of glochidia on the host body, and encapsulation success). We used the water-borne human pharmaceutical compounds methamphetamine (a central nervous system stimulant) and tramadol (an opioid) at environmentally relevant concentrations (˜ 6.7 and 3.8 nmol L-1 of methamphetamine and tramadol, respectively) as a proxy for contaminant exposure because these compounds are emerging aquatic stressors that are known for high spatial and temporal variability in their detected concentration levels. The relationship between the bivalve and the fish species was influenced by the preceding contact with both methamphetamine and tramadol, but this effect was highly asymmetric. Our experimental design enabled us to identify the specific changes in the relationship outcome that are elicited by the exposure of individual partners, such as the significant increase in glochidia infection success rate from 59.6 ± 3.9% to 78.7 ± 2.8% (means ± s.e.) that was associated with host exposure to methamphetamine. Additionally, the significant interaction effect of the exposure was demonstrated by the lowered proportion of glochidia attached to gills after the coexposure of both partners to tramadol. The impact of pharmaceuticals on wild aquatic host-parasite relationships provides an example of the risks that are associated with the unintentional discharge of biologically active compounds into freshwater habitats. Given the increasing evidence showing the ecological impact of waste pharmaceuticals, the use of multitrophic interaction endpoints after joint and unilateral exposures provides an important step towards the realistic risk assessment of these compounds.