Advances in the prediction and treatment of recurrent pancreatic cancer / 医学研究生学报

Patients with pancreatic adenocarcinoma who underwent surgical resection have poor prognosis, with the recurrence rate of over 80% within two years. Currently, the treatment of recurrent pancreatic cancer is still in the exploratory phase, and the efficacy is only limited to chemotherapy. In addition, there are differences in the efficacy of different chemotherapy schemes, and there is no unified chemotherapy scheme. Meanwhile, new radiotherapy and surgical treatment have been proposed for the treatment of recurrent pancreatic cancer, but its efficacy is yet to be confirmed. This paper summarizes the factors to predict postoperative recurrence, various chemotherapy schemes and new radiotherapy methods, reviews and analyzes the effectiveness of surgical treatment on recurrent pancreatic cancer.

Notch signaling: a novel regulating differentiation mechanism of human umbilical cord blood-derived mesenchymal stem cells into insulin-producing cells in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) could be induced to differentiate into insulin producing cells (IPCs) in vitro, which have good application potential in the cell replacement treatment of type-1 diabetes. However, the mechanisms regulating this differentiation have remained largely unknown. Notch signaling is critical in cell differentiation. This study investigated whether Notch signaling could regulate the IPCs differentiation of human UCB-MSCs.</p><p><b>METHODS</b>Using an interfering Notch signaling protocol in vitro, we studied the role of Notch signaling in differentiation of human UCB-MSCs into IPCs. In a control group the induction took place without interfering Notch signaling.</p><p><b>RESULTS</b>Human UCB-MSCs expressed the genes of Notch receptors (Notch 1 and Notch 2) and ligands (Jagged 1 and Deltalike 1). Human UCB-MSCs with over-expressing Notch signaling in differentiation resulted in the down-regulation of insulin gene level, proinsulin protein expression, and insulin-positive cells percentage compared with the control group. These results showed that over-expressing Notch signaling inhibited IPCs differentiation. Conversely, when Notch signaling was attenuated by receptor inhibitor, the induced cells increased on average by 3.06-fold (n = 4, P < 0.001) in insulin gene level, 2.60-fold (n = 3, P < 0.02) in proinsulin protein expression, and 1.62-fold (n = 6, P < 0.001) in the rate of IPCs compared with the control group. Notch signaling inhibition significantly promoted IPCs differentiation with about 40% of human UCB-MSCs that converted to IPCs, but these IPCs were not responsive to glucose challenge very well both in vitro and in vivo. Hence, further research has to be carried out in the future.</p><p><b>CONCLUSIONS</b>Notch signaling may be an important mechanism regulating IPCs differentiation of human UCB-MSCs in vitro and Notch signaling inhibition may be an efficient way to increase the number of IPCs, which may resolve the shortage of islet of cell replacement treatment of type-1 diabetes.</p>

Extracellular matrix gel is necessary for in vitro cultivation of insulin producing cells from human umbilical cord blood derived mesenchymal stem cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Pancreatic islet cell transplantation is an effective approach to treat type 1 diabetes. However, this therapy is not widely used because of the severe shortage of transplantable donor islets. This study investigated whether mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) could be transdifferentiated into insulin producing cells in vitro and the role of extracellular matrix (ECM) gel in this procedure.</p><p><b>METHODS</b>Human UCB samples were collected and MSCs were isolated. MSCs specific marker proteins were analyzed by a flow cytometer. The capacities of osteoblast and adipocyte to differentiate were tested. Differentiation into islet like cell was induced by a 15-day protocol with or without ECM gel. Pancreatic characteristics were evaluated with immunofluorescence, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. Insulin content and release in response to glucose stimulation were detected with chemiluminescent immunoassay system.</p><p><b>RESULTS</b>Sixteen MSCs were isolated from 42 term human UCB units (38%). Human UCB-MSCs expressed MSCs specific markers and could be induced in vitro into osteoblast and adipocyte. Islet like cell clusters appeared about 9 days after pancreatic differentiation in the inducing system with ECM gel. The insulin positive cells accounted for (25.2 +/- 3.4)% of the induced cells. The induced cells expressed islet related genes and hormones, but were not very responsive to glucose challenge. When MSCs were induced without ECM gel, clusters formation and secretion of functional islet proteins could not be observed.</p><p><b>CONCLUSIONS</b>Human UCB-MSCs can differentiate into islet like cells in vitro and ECM gel plays an important role in pancreatic endocrine cell maturation and formation of three dimensional structures.</p>

Experience of Congenital Choledochal Cyst in Adults: Treatment, Surgical Procedures and Clinical Outcome in the Second Affiliated Hospital of Harbin Medical University

This study was undertaken to analyze and evaluate the diagnosis and principal treatment methods for congenital choledochal cyst, focusing on various surgical procedures and clinical outcome. A comprehensive, retrospective study was conducted on 72 adult patients who presented with choledochal cyst from 1985 to 2002. Surgical procedures were cyst excision with hepaticojejunostomy in 25 cases for type I or type IV-B, extrahepatic cyst excision with hepaticojejunostomy in 8 cases for type IV-A, extrahepatic cyst excision with modified hepaticojejunostomy in 2 cases for type IV-B, non-cyst excision with or without hepaticojejunostomy in 27 cases for types I, II, IV-A, IV-B. The early postoperative morbidity and mortality rate were 16.1% (9/62) and 6.5% (4/62) respectively, and the complication rate related to surgical procedure was 30.6% (19/62). The incidence of cholangiocarcinoma with non-cyst excision or non-operated congenital choledochal cyst was 10.8% (4/37). One patient died of primary hepatocellular carcinoma after cyst excision with hepatojejunostomy. In conclusion, our results showed that complete exci-sion of choledochal cyst for types I, II, and IV-B and complete excision of extra-hepatic choledochal cyst from the hepatic hilum in type IV-A with hepaticojejunostomy or modified hepaticojejunostomy are the treatment of choice for choledochal cyst in adult patients.