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•PE-MP are ingested by organisms representative of zooplanktonic marine taxa.•Virgin or BP-3 spiked PE-MP do not cause toxic effects on marine zooplankton.•BP-3 spiked PE-MP cause ...premature hatching of fish eggs compared with virgin PE-MP.•PE-MP do not pose remarkable environmental risk on marine plankton communities.
Toxicity of polyethylene microplastics (PE-MP) of size ranges similar to their natural food to zooplanktonic organisms representative of the main taxa present in marine plankton, including rotifers, copepods, bivalves, echinoderms and fish, was evaluated. Early life stages (ELS) were prioritized as testing models in order to maximize sensitivity. Treatments included particles spiked with benzophenone-3 (BP-3), a hydrophobic organic chemical used in cosmetics with direct input in coastal areas. Despite documented ingestion of both virgin and BP-3 spiked microplastics no acute toxicity was found at loads orders of magnitude above environmentally relevant concentrations on any of the invertebrate models. In fish tests some effects, including premature or reduced hatching, were observed after 12 d exposure at 10 mg L−1 of BP-3 spiked PE-MP. The results obtained do not support environmentally relevant risk of microplastics on marine zooplankton. Similar approaches testing more hydrophobic chemicals with higher acute toxicity are needed before these conclusions could be extended to other organic pollutants common in marine ecosystems. Therefore, the replacement of these polymers in consumer products must be carefully considered.
Tau is a neuronal protein involved in microtubule stabilization and intracellular vesicle transport in axons. In neurodegenerative disorders termed “tauopathies,” like Alzheimer's and Parkinson's ...disease, tau becomes hyperphosphorylated and forms intracellular inclusions. Rhesus macaques are widely used for studying ageing processes and modeling neurodegenerative disorders, yet little is known about endogenous tau expression in their brains. In this study, immunohistochemical methods were used to map and characterize total tau, 3R‐ and 4R‐tau isoforms, and phosphorylated tau (pThr231‐tau and pSer202/Thr205‐tau/AT8) expression bilaterally in 16 brain regions of normal and 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced hemiparkinsonian adult rhesus macaques. Tau‐immunoreactivity (‐ir), including both 3R and 4R isoforms, was observed throughout the brain, with varying regional intensities. The anterior cingulate cortex, entorhinal cortex, and hippocampus displayed the most robust tau‐ir, while the subthalamic nucleus and white matter regions had minimal expression. Tau was present in neurons of gray matter regions; it was preferentially observed in fibers of the globus pallidus and substantia nigra and in cell bodies of the thalamus and subthalamic nucleus. In white matter regions, tau was abundantly present in oligodendrocytes. Additionally, neuronal pThr231‐tau‐ir was abundant in all brain regions, but not AT8‐ir. Differences in regional and intracellular protein expression were not detected between control subjects and both brain hemispheres of MPTP‐treated animals. Specifically, tau‐ir in the substantia nigra of all subjects colocalized with GABAergic neurons. Overall, this report provides an in‐depth characterization of tau expression in the rhesus macaque brain to facilitate future investigations for understanding and modeling tau pathology in this species.
Accumulation of the neuronal protein tau had been linked to neurodegenerative disorders. Rhesus macaques are widely used for studying aging and neurodegenerative disorders, yet little is known about the natural expression of tau in their brains. Here, we demonstrate that tau is present across brain regions in normal and hemiparkinsonian rhesus macaques detected by immunohistochemical methods. Tau is found in neuronal soma and fibers of gray matter brain regions and oligodendrocytes in white matter brain regions. Both 3R and 4R tau isoforms are detected. Tau phosphorylated at Thr231, but not Ser202/Thr205 (AT8), is also present. Nigral dopaminergic (TH+) cell loss associated to neurotoxin‐induced hemiparkinsonism did not affect tau expression as the protein is mainly expressed in nigral GABAergic (GAD67+) cells.
α-Synuclein (α-syn) proteinopathy in the neurons of the Enteric Nervous System (ENS) is proposed to have a critical role in Parkinson's disease (PD) onset and progression. Interestingly, the ENS of ...the human appendix harbors abundant α-syn and appendectomy has been linked to a decreased risk and delayed onset of PD, suggesting that the appendix may influence PD pathology. Common marmosets and rhesus macaques lack a distinct appendix (a narrow closed-end appendage with a distinct change in diameter at the junction with the cecum), yet the cecal microanatomy of these monkeys is similar to the human appendix. Sections of human appendix (n = 3) and ceca from common marmosets (n = 4) and rhesus macaques (n = 3) were evaluated to shed light on the microanatomy and the expression of PD-related proteins. Analysis confirmed that the human appendix and marmoset and rhesus ceca present thick walls comprised of serosa, muscularis externa, submucosa, and mucosa plus abundant lymphoid tissue. Across all three species, the myenteric plexus of the ENS was located within the muscularis externa with nerve fibers innervating all layers of the appendix/ceca. Expression of α-syn and tau in the appendix/cecum was present within myenteric ganglia and along nerve fibers of the muscularis externa and mucosa in all species. In the myenteric ganglia α-syn, p-α-syn, tau and p-tau immunoreactivities (ir) were not significantly different across species. The percent area above threshold of α-syn-ir and tau-ir in the nerve fibers of the muscularis externa and mucosa were greater in the human appendix than in the NHP ceca (α-syn-ir p<0.05; tau-ir p<0.05). Overall, this study provides critical translational evidence that the common marmoset and rhesus macaque ceca are remarkably similar to the human appendix and, thus, that these NHP species are suitable for studying the development of PD linked to α-syn and tau pathological changes in the ENS.
Solitary hamartomatous polyps with identical pathological features of the typical hamartomas of the Peutz-Jegher syndrome are extremely rare. These solitary lesions lack the associated intestinal ...polyposis, classic mucocutaneous pigmentation, and family history typifying the Peutz-Jegher syndrome. We describe the case of a 31-year-old woman with a giant solitary gastric hamartoma endoscopically diagnosed and laparoscopically resected.
Laparoscopic sleeve gastrectomy (LSG) is a commonly used procedure in bariatric patients that often has excellent results. Despite its advantages, LSG is burdened by specific intraoperative and ...postoperative early and late complications. One of the life-threatening complications is gastric fistula, usually treated with a multidisciplinary surgical–endoscopic approach. In case of failure of the latter, alternative nonoperative techniques such as the use of autologous stem cells truly represents an innovative possibility, with only few cases described in literature. Here, we report the case of a 25-year-old man with post-LSG broncho-gastric fistula treated with application of autologous stem cells after the failure of the conventional surgical/endoscopic approach.
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