Browsing by Author "Zhang, Dongwei"

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    Assessment of Submucosal Distortion and Mass Effect Seen at Follow-up After Colorectal Endoscopic Mucosal Resection with ORISE
    (Elsevier, 2022-05) Lahr, Rachel E.; DeWitt, John M.; Zhang, Dongwei; Rex, Douglas K.; Medicine, School of Medicine
    Recovery from spinal cord injury (SCI) and other central nervous system (CNS) trauma is hampered by limits on axonal regeneration in the CNS. Regeneration is restricted by the lack of neuron-intrinsic regenerative capacity and by the repressive microenvironment confronting damaged axons. To address this challenge, we have developed a therapeutic strategy that co-targets kinases involved in both extrinsic and intrinsic regulatory pathways. Prior work identified a kinase inhibitor (RO48) with advantageous polypharmacology (co-inhibition of targets including ROCK2 and S6K1), which promoted CNS axon growth in vitro and corticospinal tract (CST) sprouting in a mouse pyramidotomy model. We now show that RO48 promotes neurite growth from sensory neurons and a variety of CNS neurons in vitro, and promotes CST sprouting and/or regeneration in multiple mouse models of spinal cord injury. Notably, these in vivo effects of RO48 were seen in several independent experimental series performed in distinct laboratories at different times. Finally, in a cervical dorsal hemisection model, RO48 not only promoted growth of CST axons beyond the lesion, but also improved behavioral recovery in the rotarod, gridwalk, and pellet retrieval tasks. Our results provide strong evidence for RO48 as an effective compound to promote axon growth and regeneration. Further, they point to strategies for increasing robustness of interventions in pre-clinical models.
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    Characterization of endoscopic features and histology of a distinct mucosal transition zone on the ileocecal valve (with video)
    (Elsevier, 2023-09) Rex, Douglas K.; Lahr, Rachel E.; Guardiola, John J.; Dewitt, John M.; Zhang, Dongwei; Medicine, School of Medicine
    Background and Aims We have endoscopically encountered a zone of transitional mucosa between the colonic and ileal mucosa located in a 3- to 10-mm-wide ring around the ileocecal valve (ICV) orifice. We aimed to describe the features of the ICV transitional zone mucosa. Methods We used videos and photographs from normal ICVs and biopsy samples from normal colonic mucosa, transitional zone mucosa, and normal ileal mucosa to characterize the endoscopic and histologic features of the ICV transitional zone mucosa. Results The ICV transitional zone is identifiable on every ICV without a circumferential adenoma or inflammation that obliterates the zone. The zone is characterized endoscopically by an absence of villi, which distinguishes it from the ileal mucosa, but the pits are more tubular and with more prominent blood vessels compared with normal colonic mucosa. Histologically, the villi of the transitional zone are blunted, and the amount of lymphoid tissue is intermediate between the colonic mucosa and ileal mucosa. Conclusions This is the first description of the normal transitional zone of mucosa on the ICV. This zone has unique endoscopic features that should be recognized by colonoscopists and that can potentially create difficulty in identifying the margins of adenomas located on the ICV.
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    Splenic-vasculature involvement is associated with poor prognosis in resected distal pancreatic cancer
    (Oxford University Press, 2020-11-24) Yin, Feng; Saad, Mohammed; Lin, Jingmei; Jackson, Christopher R.; Ren, Bing; Lawson, Cynthia; Karamchandani, Dipti M.; Bernabeu, Belen Quereda; Jiang, Wei; Dhir, Teena; Zheng, Richard; Schultz, Christopher W.; Zhang, Dongwei; Thomas, Courtney L.; Zhang, Xuchen; Lai, Jinping; Schild, Michael; Zhang, Xuefeng; Xie, Hao; Liu, Xiuli; Pathology and Laboratory Medicine, School of Medicine
    Background: Distal pancreatic carcinoma is one of the most lethal cancers largely due to its high incidence of distant metastasis. This study aims to assess the prognostic value of splenic-vasculature involvement in resected distal pancreatic carcinoma. Methods: In this retrospective study, we collected the clinicopathologic information of 454 patients with pancreatic cancer and performed univariate and multivariate analyses to identify factors associated with progression-free survival (PFS) and overall survival (OS), with an emphasis on the prognostic value of splenic-artery and -vein involvement. Results: Univariate analysis revealed that larger tumor size, non-intraductal papillary mucinous neoplasm (non-IPMN)-associated adenocarcinoma, poor differentiation, stage pT3, nodal metastasis, lymphovascular invasion, perineural invasion, and pathologic and radiographic evidence of splenic-vein invasion were significantly associated with shorter PFS and OS (all P < 0.05). Multivariate analysis confirmed non-IPMN-associated adenocarcinoma, stage pT3, stage pN1-2, and post-operative adjuvant chemotherapy as independent risk factors for both PFS and OS, and larger tumor size and radiographic evidence of splenic-artery invasion as predictors of PFS only. Conclusion: Guidelines should be developed for a uniform approach with regard to the examination and reporting of the status of the splenic vasculature when dealing with distal-pancreatic-cancer specimens.
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    Validation of American Joint Committee on Cancer 8th edition of TNM staging in resected distal pancreatic cancer
    (Baishideng, 2020-06-09) Yin, Feng; Saad, Mohammed; Xie, Hao; Lin, Jingmei; Jackson, Christopher R.; Ren, Bing; Lawson, Cynthia; Karamchandani, Dipti M.; Bernabeu, Belen Quereda; Jiang, Wei; Dhir, Teena; Zheng, Richard; Schultz, Christopher W.; Zhang, Dongwei; Thomas, Courtney L.; Zhang, Xuchen; Lai, Jinping; Schild, Michael; Zhang, Xuefeng; Liu, Xiuli; Medicine, School of Medicine
    BACKGROUND In order to improve risk stratification and clinical management of the pancreatic ductal adenocarcinoma (PDAC), the American Joint Committee on Cancer (AJCC) has published its eighth edition staging manual. Some major changes have been introduced in the new staging system for both T and N categories. Given the rarity of resectable disease, distal pancreatic cancer is likely underrepresented in the published clinical studies, and how the impact of the staging system actually reflects on to clinical outcomes remain unclear. AIM To validate the AJCC 8th edition of TNM staging in distal PDAC. METHODS A retrospective cohort study was performed in seven academic medical centers in the United States. Clinicopathological prognostic factors associated with progression-free survival (PFS) and overall survival (OS) were evaluated through univariate and multivariate analyses. RESULTS Overall, 454 patients were enrolled in the study, and were divided into 2 subgroups: Invasive intraductal papillary mucinous neoplasms (IPMN) (115 cases) and non-IPMN associated adenocarcinoma (339 cases). Compared to invasive IPMN, non-IPMN associated adenocarcinomas are more common in relatively younger patients, have larger tumor size, are more likely to have positive lymph nodes, and are associated with a higher tumor (T) stage and nodal (N) stage, lymphovascular invasion, perineural invasion, tumor recurrence, and a worse PFS and OS. The cohort was predominantly categorized as stage 3 per AJCC 7th edition staging manual, and it’s more evenly distributed based on 8th edition staging manual. T and N staging of both 7th and 8th edition sufficiently stratify PFS and OS in the entire cohort, although dividing into N1 and N2 according to the 8th edition does not show additional stratification. For PDAC arising in IPMN, T staging of the 7th edition and N1/N2 staging of the 8th edition appear to further stratify PFS and OS. For PDAC without an IPMN component, T staging from both versions fails to stratify PFS and OS. CONCLUSION The AJCC 8th edition TNM staging system provides even distribution for the T staging, however, it does not provide better risk stratification than previous staging system for distal pancreatic cancer.