Primary colonic melanoma presenting as ileocecal intussusception: Case report and literature review

Primary malignant melanoma originating in the colon is an extremely rare disease.Herein,we report a case of primary melanoma of the ascending colon.The patient was a 57-year-old male who was admitted to our hospital for persistent abdominal pain and episodes of bloody stool,nausea and vomiting.A computed tomography scan revealed lower intestinal intussusception and enlarged lymph nodes in the abdominal cavity and retroperitoneum.During laparoscopic operation,multiple enlarged lymph nodes were found.Several segments of the proximal small intestine were incarcerated into the distal small intestine,forming an internal hernia and obstruction.The necrotic terminal ileum was invaginated into the ascending cecum.Subsequently,adhesive internal hernia reduction and palliative right hemicolectomy were performed.Pathologic examination of the excised specimen revealed a polypoid mass in the ascending colon.Histological examination showed epithelioid and spindle tumor cells with obvious cytoplasmic melanin deposition.Immunohistochemical staining revealed that the tumor cells were positive for S-100,HmB-45 and vimentin,confirming the diagnosis of melanoma.The patient history and a thorough postoperative investigation excluded the preexistence or coexistence of a primary lesion elsewhere in the skin,anus or oculus or at other sites.Thus,we consider our case to represent an aggressive primary colon melanoma presenting as ileocecal intussusception and intestinal obstruction.

Alterations of Thymic Epithelial Cells in Lipopolysaccharide-induced Neonatal Thymus Involution

Background： Vascular endothelial growth factor （VEGF） in the thymus was mainly produced by the thymic epithelial cells （TECs）, the predominant component of the thymic microenvironment. The progression of TECs and the roles of VEGF in the neonatal thymus during sepsis have not been reported. This study aimed to explore the alterations of TECs and VEGF level in the neonatal thymus involution and to explore the possible mechanisms at the cellular level. Methods： By establishing a model of clinical sepsis, the changes of TECs were measured by hematoxylin-eosin staining. confocal microscopy, and flow cytometry. Moreover, the levels of VEGF in serum and thymus were assessed based on enzyme-linked immunosorbent assay and Western blotting. Results： The number ofthymocytes and TECs was significantly decreased 2411 after lipopolysaccharide （LPS） challenge. （2.40 ± 0,46）× 10^7 vs. （3.93 ± 0.66）× 10^7 and （1.16 ± 0.14）× 10^5 vs. （2.20 ± 0.19）× 10^5, P 〈 0.05, respectively. Cortical TECs and medullary TECs in the LPS-treated mice were decreased 1.5-fold and 3.9-fold, P 〈 0.05, respectively, lower than those in the controls. The number of thymic epithelial progenitors was also decreased. VEGF expression in TECs was down-regulated in a time-dependent manner. Conclusion： VEGF in thymic cells subsets might contribute to the development of TECs in neonatal sepsis.

Fluorescent Detection of Cu(Ⅱ) by Chitosan-based AIE Bioconjugate

Detection of Cu（Ⅱ） is very important in disease diagnose, biological system detection and environmental monitoring. Previously, we found that the product TPE-CS prepared by attaching the chromophores of tetraphenylethylene（TPE） to the chitosan（CS） chains showed excellent fluorescent properties. In this study, we tried to use TPE-CS for detecting Cu（Ⅱ） because of the stable complexation of CS with heavy metals and the luminosity mechanism of the Restriction of Intramolecular Rotations（RIR） for aggregation-induced emission（AIE）-active materials. The fluorescence intensity changed when TPE-CS was contacted with different metal ions, to be specific, no change for Na;, slightly increase for Hg;, Pb;, Zn;, Cd;, Fe;, Fe;due to the RIR caused by the complexation between CS and metal ions. However, for Cu;, an obvious fluorescence decrease was observed because of the Photoinduced-Electron-Transfer（PET）. Moreover, we found that the quenched FL intensity of TPE-CS was proportional to the concentration of Cu（Ⅱ） in the range of 5 μmol/L to 100 μmol/L, which provided a new way to quantitatively detect Cu（Ⅱ） . Besides, TPE-CS has excellent water-solubility as well as absorbability（the percentage of removal, R = 84%）, which is an excellent detection probe and remover for Cu（Ⅱ） .

Condition dependence of Zr electrochemical reactions and morphological evolution of Zr deposits in molten salt

This work presents a comprehensive study for the electrochemical behaviors of zirconium in LiCl-KCl eutectic.The effects of stirring,temperature and Zr concentration on the electrode reactions,the ZrCl_4 sublimation from the melt,microcosmic morphologies of Zr deposits(ZrCl and Zr)obtained at different potential and temperature have been investigated.The behaviors of Zr(Ⅳ),on a large concentration range from 0.13%to 2.28%in melt,show a multiple-step reaction involving Zr(Ⅳ),Zr(Ⅱ),ZrCl and Zr species.Temperature plays a crucial role on the changes of Zr(IV)reduction behavior on the solid electrode.The Zr(Ⅳ)/ZrCl couple is more easily observed at lower temperature and gradually diminishes with the increase of temperature.The Zr(Ⅳ)/Zr(Ⅱ)and Zr(Ⅱ)/Zr reactions are predominant on the W electrode at higher temperatures.At 673 K,a layered structure of insoluble ZrCl formed by potentiostatic electrolyses at 1.1 V was visualized by scanning electron microscopy-energy dispersive X-ray(SEM-EDS),while only Zr metal particles was observed at higher temperature than 773 K.An evolution of the Zr-based structure and size corresponding to the ZrCl and Zr metal based on different potentiostatic electrolysis was observed.The average particle size of the Zr metalparticles increases with the increase of temperature.

Challenges for Obstetricians and the Countermeasures of COVID-19 Epidemic

Since the outbreak of the novel coronavirus in Wuhan,China,as obstetricians,we also face great challenges.We need to identify pregnant patients with 2019 coronavirus disease infection timely,and give them appropriate treatment in order to obtain a good maternal and infant prognosis.Here,we would like to share a case and provide some suggestions on how to screen,diagnose and treat pregnant women with 2019 coronavirus disease infection during the outbreak.