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The transplantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) can promote hypoxic-ischemic brain damage (HIBD) nerve repair, but finding suitable seed cells to optimize transplantation and improve treatment efficiency is an urgent problem to be solved. In this study, we induced hUC-MSCs into dedifferentiated hUC-MSCs (De-hUC-MSCs), and the morphology, stem cell surface markers, proliferation and tri-directional differentiation ability of the De-hUC-MSCs and hUC-MSCs were detected. A whole-gene chip was utilized for genome cluster, gene ontology and KEGG pathway analyses of differentially expressed genes. De-hUC-MSCs were transplanted into HIBD rats, and behavioral experiments and immunofluorescence assays were used to assess the therapeutic effect. A lentivirus vector for human stromal cell-derived factor-1 (hSDF-1α) was constructed, and the role of hSDF-1α in the neuroprotective effect and mechanism of De-hUC-MSCs was verified. De-hUC-MSCs displayed similar cell morphology, stem cell surface marker expression, cell proliferation and even three-dimensional differentiation ability as hUC-MSCs but exhibited greater treatment potential in vivo. The reprogramming mechanism of hSDF-1α participated in the dedifferentiation process. By successfully constructing a stable hSDF-1α cell line, we found that De-hUC-MSCs might participate in nerve repair through the hSDF-1α/CXCR4/PI3K/Akt pathway. De-hUC-MSCs reprogramming of endogenous hSDF-1α expression may mediate the hSDF-1α/CXCR4/PI3K/Akt pathway involved in nerve repair in HIBD rats.
RESUMEN
Objective To investigate the clinical characteristics and etiology in infants undergoing colonoscopy in order to improve the understandings of lower gastrointestinal tract diseases and their endoscopic manifestations.Methods The clinical and endoscopic data of the infants aged ≤ 3 years old who underwent conoloscopy at the Department of Gastroenterology,Children's Hospital of Chongqing Medical University,from July 2010 to December 2014,were retrospectively analyzed.A total of 223 children were included,148 male and 75 female.The age range was from 26 d to 3 years old(＜6 months:41 cases;6-12 months:68 cases;1-3 years old:114 cases).Results A total of 235 colonoscopies were performed under deep sedation by single or double manipulators.Cecal intubation was successful in 192 colonoscopies and terminal ileal intubation was completed in 29 colonoscopies,with a high success rate of 94.0％ (221/235 colonoscopies).The main symptoms included hematochezia (124 cases,55.6％),persistent/chronic diarrhea (55 cases,24.7％),hematochezia with chronic diarrhea(22 cases,9.5％),and others(22 cases,9.5％).Of the 223 patients,clear diagnosis were established for 215 children (96.4％),with food protein-induced proctocolitis (FPIPC) (78/223 cases,35.0％),colonic polyps (50/223 cases,22.4％),colitis (29/223 cases,13.0％),antibiotic associated diarrhea (AAD) (19/223 cases,8.5％),FPIPC with AAD (10/223 cases,4.5％).Conclusions Colonoscopy serves as a very important tool for the accurate diagnosis of lower gastrointestinal diseases with hematochezia and/or chronic diarrhea.FPIPC and colonic polyps are the most common causes for hematochezia and/or chronic diarrhea.AAD may be another important cause of chronic diarrhea and bloody stool in infants.Moreover,ghe application of colonoscopy in combination with histopathology can also play an important role in the diagnosis of some rare diseases,such as intestinal tuberculosis,primary intestinal lymphangiectasia,Behcet's disease and primary immunodeficiency disease.
