Effects of arsenic on gut microbiota and its bioaccumulation and biotransformation in freshwater invertebrate.

This study aimed to investigate the impact of arsenic stress on the gut microbiota of a freshwater invertebrate, specifically the apple snail (Pomacea canaliculata), and elucidate its potential role in arsenic bioaccumulation and biotransformation. Waterborne arsenic exposure experiments were conducted to characterize the snail's gut microbiomes. The results indicate that low concentration of arsenic increased the abundance of gut bacteria, while high concentration decreased it. The dominant bacterial phyla in the snail were Proteobacteria, Firmicutes, Bacteroidota, and Actinobacteriota. In vitro analyses confirmed the critical involvement of the gut microbiota in arsenic bioaccumulation and biotransformation. To further validate the functionality of the gut microbiota in vivo, antibiotic treatment was administered to eliminate the gut microbiota in the snails, followed by exposure to waterborne arsenic. The results demonstrated that antibiotic treatment reduced the total arsenic content and the proportion of arsenobetaine in the snail's body. Moreover, the utilization of physiologically based pharmacokinetic modeling provided a deeper understanding of the processes of bioaccumulation, metabolism, and distribution. In conclusion, our research highlights the adaptive response of gut microbiota to arsenic stress and provides valuable insights into their potential role in the bioaccumulation and biotransformation of arsenic in host organisms. ENVIRONMENTAL IMPLICATION: Arsenic, a widely distributed and carcinogenic metalloid, with significant implications for its toxicity to both humans and aquatic organisms. The present study aimed to investigate the effects of As on gut microbiota and its bioaccumulation and biotransformation in freshwater invertebrates. These results help us to understand the mechanism of gut microbiota in aquatic invertebrates responding to As stress and the role of gut microbiota in As bioaccumulation and biotransformation.

Effects of naturally aged microplastics on the distribution and bioavailability of arsenic in soil aggregates and its accumulation in lettuce.

Naturally aged microplastics (NAMPs) and arsenic (As) have been reported to coexist in and threaten potentially to soil-plant ecosystem. The research explored the combined toxic effects of NAMPs and As to lettuce (Lactuca sativa L.) growth, and the distribution, accumulation and bioavailability of As in soil aggregates. The As contaminated soil with low, medium and high concentrations (L-As, M-As, H-As) were treated with or without NAMPs, and a total of six treatments. The results displayed that, in comparison to separate treatments of L-As and M-As, the presence of NAMPs increased the total biomass of lettuce grown at these two As concentrations by 68.9 % and 55.4 %, respectively. Simultaneous exposure of NAMPs and L-As or M-As led to a decrease in As content in shoot (0.45-2.17 mg kg-1) and root (5.68-14.66 mg kg-1) of lettuce, indicating an antagonistic effect between them. In contrast, co-exposure to H-As and NAMPs showed synergistic toxicity, and the leaf chlorophyll and nutritional quality of lettuce were also reduced. NAMPs altered the ratio of different soil aggregate fractions and the distribution of bioavailable As within them, which influenced the absorption of As by lettuce. In conclusion, these direct observations assist us in enhancing the comprehend of the As migration and enrichment characteristics in soil-plant system under the influence of NAMPs.

Laparoscopic radical gastrectomy for gastric cancer: Long-term outcome in a teaching center.

BACKGROUND: Laparoscopic gastrectomy for gastric cancer (GC) are increasing, yet the evidence of the relationship between the learning curve and long-term outcomes is limited. AIMS: To analyze the relationship between the learning curve and survival in GC patients over a 10-year period. METHODS: This retrospective cohort study studied 3674 patients who underwent laparoscopic radical gastrectomy for gastric cancer. Cusum and Cox regression analysis were used to assess the association between the surgeon's experience and the 3 years overall survival (OS). RESULTS: The 3-year OS of all patients was 71.8 %. This increase of 3-year OS was associated with laparoscopic cases (r = 0.638, p = 0.047). Analysis of the CUSUM curve showed a significant change in the 3-year OS of 1400 cases. Further propensity score matching (PSM) of patients during and after the learning curve (<1400 and ≥ 1400 cases) showed a significant difference in the 3-year OS between the two groups (68.5 % vs. 72.3 %, p = 0.045). Cox regression analysis verified that in ≥1400 cases, prior laparoscopic surgery (p = 0.045), textbook outcome (TO) and the number of retrieved lymph nodes (LNs) were independent protective factors. The LN non-compliance rate was an independent risk factor. In contrast, the rate of TO and the median number of retrieved LNs were significantly higher after the learning curve (≥1400 cases). Furthermore, the rates of LN non-compliance were significantly lower (p < 0.05). CONCLUSIONS: Increasing laparoscopic surgical experience is associated with surgical quality and prognostic improvement in patients with gastric cancer. But improvements in outcomes accrued slowly over a long period.

Neurotransmitter Receptor HTR2B Regulates Lipid Metabolism to Inhibit Ferroptosis in Gastric Cancer.

Nerves can support tumor development by secreting neurotransmitters that promote cancer cell proliferation and invasion. 5-Hydroxytryptamine (5-HT) is a critical neurotransmitter in the gastrointestinal nervous system, and 5-HT signaling has been shown to play a role in tumorigenesis. Here, we found that expression of the 5-HT receptor HTR2B was significantly elevated in human gastric adenocarcinoma tissues compared with nontumor tissues, and high HTR2B expression corresponded to shorter patient survival. Both 5-HT and a specific HTR2B agonist enhanced gastric adenocarcinoma cell viability under metabolic stress, reduced cellular and lipid reactive oxygen species, and suppressed ferroptosis; conversely, HTR2B loss or inhibition with a selective HTR2B antagonist yielded the inverse tumor suppressive effects. In a patient-derived xenograft tumor model, HTR2B-positive tumors displayed accelerated growth, which was inhibited by HTR2B antagonists. Single-cell analysis of human gastric adenocarcinoma tissues revealed enrichment of PI3K/Akt/mTOR and fatty acid metabolism-related gene clusters in cells expressing HTR2B compared with HTR2B-negative cells. Mechanistically, HTR2B cooperated with Fyn to directly regulate p85 activity and trigger the PI3K/Akt/mTOR signaling pathway, which led to increased expression of HIF1α and ABCD1 along with decreased levels of lipid peroxidation and ferroptosis. Together, these findings demonstrate that HTR2B activity modulates PI3K/Akt/mTOR signaling to stimulate gastric cancer cell survival and indicate that HTR2B expression could be a potential prognostic biomarker in patients with gastric cancer. SIGNIFICANCE: Nerve cancer cross-talk mediated by HTR2B inhibits lipid peroxidation and ferroptosis in gastric cancer cells and promotes viability under metabolic stress, resulting in increased tumor growth and decreased patient survival.

Endoscopic Transconjunctival Deep Lateral Wall Decompression for Thyroid-associated Orbitopathy: A Minimally Invasive Alternative: Transconjunctival Endoscopic with Wall Decompression for TAO.

PURPOSE: To investigate the feasibility, efficacy, and safety of endoscopic transconjunctival transorbital deep lateral wall decompression for thyroid-associated orbitopathy (TAO). DESIGN: Prospective single-surgeon interventional case series. METHODS: Twenty-two patients (39 orbits) diagnosed with thyroid-associated orbitopathy without dysthyroid optic neuropathy were enrolled in this study. All patients underwent endoscopic transconjunctival transorbital deep lateral wall decompression for proptosis reduction. The data, including measurement on exophthalmometry, volumetric change on computed tomography, and surgery-related complications, were analyzed. RESULTS: We observed a proptosis reduction (mean, 3.42 ± 0.87 mm; range, 2.10-5.52 mm) and a corresponding decrease in the bony volume of the greater wing of the sphenoid bone (mean, 1.89 ± 0.81 cm3; range, 0.56-3.79 cm3) postoperatively. Preexisting diplopia improved in 5 patients (22.73%). Transient zygomaticotemporal hypoesthesia developed in all patients, and cerebrospinal fluid leakage occurred in 1 orbit (2.56%). No patient complained of temporal hollowing, oscillopsia, or new-onset or worsening diplopia during follow-up. CONCLUSIONS: Endoscopic transconjunctival transorbital deep lateral wall decompression is an effective and minimally invasive treatment for proptosis reduction in patients with thyroid-associated orbitopathy. The surgery-related complications with this technique were fewer compared with traditional approaches.