Thoracotomy of an asymptomatic, functional, posterior mediastinal paraganglioma: A case report

BACKGROUND Paragangliomas in the mediastinum are rare, accounting for only 1%-2% of all paragangliomas and < 0.3% of all mediastinal tumors. Most paragangliomas are nonfunctional, therefore, asymptomatic functional paragangliomas in the left posterior mediastinum are extremely rare. Perioperative management including preoperative preparation, careful intraoperative procedures, and strict postoperative care is important, and one-stage surgical resection should be performed only after appropriate perioperative measures are undertaken. Because those tumors are rare, it is necessary to report known cases to raise awareness regarding them. CASE SUMMARY We report the case of a 47-year-old male who was admitted to our hospital with the chief complaints of intermittent tearing pain on the left side of the chest and back for more than 10 mo. A chest contrast-enhanced computed tomography scan revealed a round, solid mass in the left posterior mediastinum, with low-density cystic lesions in the middle, and no enlarged lymph nodes in the hilum or mediastinum (Figure 1). After the diagnosis of paraganglioma, the patient was preoperatively given an oral adrenoceptor blocking drug (phenoxybenzamine), and intravenous fluid resuscitation for two weeks, subsequently the patient underwent a one-stage resection of lesions via left thoracotomy. The patient’s blood pressure increased to 220/120 mmHg when the tumor was touched, which could be relieved by symptomatic treatment such as accelerating liquid transfusion or other intervention to lower blood pressure. The patient recovered uneventfully after surgery, with no abnormal blood pressure or recurrence during one year of follow-up visits.CONCLUSION Surgical resection is the preferred treatment for asymptomatic functional paragangliomas.

Immunopathobiology and therapeutic targets related to cytokines in liver diseases

Chronic liver injury with any etiology can progress to fibrosis and the end-stage diseases cirrhosis and hepatocellular carcinoma.The progression of liver disease is controlled by a variety of factors,including liver injury,inflammatory cells,inflammatory mediators,cytokines,and the gut microbiome.In the current review,we discuss recent data on a large number of cytokines that play important roles in regulating liver injury,inflammation,fibrosis,and regeneration,with a focus on interferons and T helper(Th)1,Th2,Th9,Th17,interleukin(IL)-1 family,IL-6 family,and IL-20 family cytokines.Hepatocytes can also produce certain cytokines(such as IL-7,IL-11;and IL-33),and the functions of these cytokines in the liver are briefly summarized.Several cytokines have great therapeutic potential,and some are currently being tested as therapeutic targets in clinical trials for the treatment of liver diseases,which are also described.

Kupffer cell restoration after partial hepatectomy is mainly driven by local cell proliferation in IL-6-dependent autocrine and paracrine manners

Kupffer cells(KCs),which are liver-resident macrophages,originate from the fetal yolk sac and represent one of the largest macrophage populations in the body.However,the current data on the origin of the cells that restore macrophages during liver injury and regeneration remain controversial.Here,we address the question of whether liver macrophage restoration results from circulating monocyte infiltration or local KC proliferation in regenerating livers after partial hepatectomy(PHx)and uncover the underlying mechanisms.By using several strains of genetically modified mice and performing immunohistochemical analyses,we demonstrated that local KC proliferation mainly contributed to the restoration of liver macrophages after PHx.Peak KC proliferation was impaired in Il6-knockout(KO)mice and restored after the administration of IL-6 protein,whereas KC proliferation was not affected in Il4-KO or Csf2-KO mice.The source of IL-6 was identified using hepatocyte-and myeloid-specific Il6-KO mice and the results revealed that both hepatocytes and myeloid cells contribute to IL-6 production after PHx.Moreover,peak KC proliferation was also impaired in myeloid-specific Il6 receptor-KO mice after PHx,suggesting that IL-6 signaling directly promotes KC proliferation.Studies using several inhibitors to block the IL-6 signaling pathway revealed that sirtuin 1(SIRT1)contributed to IL-6-mediated KC proliferation in vitro.Genetic deletion of the Sirt1 gene in myeloid cells,including KCs,impaired KC proliferation after PHx.In conclusion,our data suggest that KC repopulation after PHx is mainly driven by local KC proliferation,which is dependent on IL-6 and SIRT1 activation in KCs.