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Silymarin is a polyphenolic flavonoid that has a strong antioxidant activity and exhibits anticarcinogenic, antiinflammatory, and cytoprotective effects. Although its hepatoprotective effect has been well documented, the effect of silymarin on pancreatic beta-cells is largely unknown. In this study, the effect of silymarin on IL-1beta and/or interferon (IFN)-gamma-induced beta-cell damage was investigated using RINm5F cells and human islets. IL-1beta and/or IFN-gamma induced cell death in a time-dependent manner in RINm5F cells. The time-dependent increase in cytokine-induced cell death appeared to correlate with the time-dependent nitric oxide (NO) production. Silymarin dose-dependently inhibited both cytokine-induced NO production and cell death in RINm5F cells. Treatment of human islets with a combination of IL-1beta and IFN-gamma (IL-1beta+IFN-gamma), for 48 h and 5 d, resulted in an increase of NO production and the impairment of glucose-stimulated insulin secretion, respectively. Silymarin prevented IL-1beta+IFN-gamma-induced NO production and beta-cell dysfunction in human islets. These cytoprotective effects of silymarin appeared to be mediated through the suppression of c-Jun NH2-terminal kinase and Janus kinase/signal transducer and activator of transcription pathways. Our data show a direct cytoprotective effect of silymarin in pancreatic beta-cells and suggest that silymarin may be therapeutically beneficial for type 1 diabetes.

Background Apoptosis in isolated islets has been implicated in primary nonfunction or early graft failure after islet transplantation. Recently, pancreas preservation by the 2-layer method (TLM) before islet isolation has been proved to improve the islet yield, quality, and transplant results not only in experimental models, but also in clinical settings. We examined the influence of TLM on apoptosis of isolated islets. Method Rat islets freshly isolated and after pancreas preservation by TLM or conventional cold storage in University of Wisconsin solution (UW) were examined and compared. Islet apoptosis was assessed by TUNEL and annexin V assays. The apoptosis pathways involved were investigated by measurement of caspase 3, 8, and 9 activities and by immunoblotting for total and phosphorylated c-Jun NH2-terminal kinase (JNK) and p38. Results Islet apoptosis in the UW group was significantly increased compared with the fresh and TLM groups. Both caspase 3 and 9 activities in the UW group were higher than in the fresh and TLM groups with an approximate increase of 2- to 3-fold. On the other hand, there was no significant difference in caspase 8 activity among these 3 groups. JNKs were strongly activated both in the TLM and UW groups; although they were not activated in the fresh group, p38 was activated to almost the same levels in these 3 groups. Conclusions Pancreas preservation by TLM before islet isolation protects isolated islets against apoptosis mainly through the mitochondrial pathway. Pancreas storage before islet isolation even with TLM triggers activation of JNKs in isolated islets.

Complete mesocolic excision with central vascular ligation is considered to contribute to superior oncological outcomes after colon cancer surgery [1]. For advanced right-sided colon cancer, this surgery sometimes requires lymph node (LN) dissection along the superior mesenteric vein (SMV), with division of the middle colic vessels, or their right branches, at origin [2]. Here, we present cranially approached radical LN dissection along the surgical trunk during laparoscopic right hemicolectomy. The omental bursa is first opened wide, and the gastrocolic trunk of Henle is exposed, using the right gastroepiploic vessels and the accessory right colic vein (ARCV) as landmarks. After division of ARCV, SMV and middle colic vein (MCV) are identified. After dividing MCV at its root, LN dissection along SMV is conducted in a cranial-to-caudal manner. Concurrently, the middle colic artery, or its right branch, is exposed and divided at origin. The transverse colon is then raised ventrally, and LN dissection along SMV using a cranial-to-caudal approach is again performed. The ileocolic and right colic vessels are divided at origin. The ascending and transverse mesocolon, including the pedicles, are then separated from the retroperitoneal tissues, pancreatic head, and duodenum, using a medial approach. The key characteristics in this procedure consist of easy access to pancreas, early division of ARCV and middle colic vessels at origin, and easy dissection along SMV. We performed a laparoscopic colectomy using this approach for 18 patients with right-sided colon cancer. The mean operative time and blood loss were 288 min and 83 ml, respectively. The mean number of harvested LNs was 24. There were 6 cases with positive LN metastasis. There were no recurrent cases at a median follow-up period of 24 months. We consider this approach to be safe and useful for radical LN dissection along SMV for right-sided colon cancers.

Receptor tyrosine kinases (RTKs) play several crucial roles in developmental morphogenesis, regulating cellular proliferation, differentiation, and migration, as well as survival and death (26, 30). The Ror family RTKs are a recently identified family of orphan RTKs, characterized by the presence of extracellular Frizzled-like cysteine-rich domains and membrane-proximal Kringle domains, both of which are assumed to mediate protein-protein interactions (15, 20, 24, 25, 29). The Ror family RTKs are evolutionarily conserved among Caenorhabditis elegans, Drosophila, mice, and humans (7, 14, 19, 20, 34). Pairs of structurally similar Ror family RTKs are found in Drosophila and mammals: Dror and Dnrk in Drosophila melanogaster, Ror1 and Ror2 in humans, and mRor1 and mRor2 in mice. Although it has been reported that CAM-1, a C. elegans ortholog of the Ror family RTKs, plays several important roles in regulating cellular migration, polarity of asymmetric cell divisions, and axonal outgrowth of neurons during nematode development (7), the functional and developmental roles of the mammalian Ror family RTKs remain largely elusive. The spatial and temporal expression of mRor1 and mRor2 mostly overlap and are detected in the face, limbs, heart, and lungs during mouse embryogenesis (16). These expression patterns suggest that mRor1 and mRor2 may interact to play a role in the development of these organs. It has been shown that mice lacking mRor2 expression exhibit dwarfism, short limbs (with mesomelic dysplasia) and tail, facial anomalies, ventricular septal defect (VSD), and respiratory dysfunction, ultimately leading to neonatal lethality (5, 32). Histological analyses of the skeletal systems reveal that mRor2 plays a crucial role in the proliferation, differentiation, maturation, and motility of chondrocytes (5, 32). Interestingly, it has recently been reported that mutations within Ror2 can cause the autosomal recessive Robinow syndrome or autosomal dominant brachydactyly type B in humans (1, 21, 31, 33), further emphasizing essential roles of Ror2 in morphogenetic and developmental processes. However, little is known about the function of mRor1 during mouse development. In order to elucidate the functional and developmental roles of mRor1, we generated mice lacking a functional mRor1 gene by targeted gene disruption. mRor1−/− mice died within 24 h after birth, presumably due to respiratory dysfunction. However, unlike the mRor2−/− mice, they did not exhibit any obvious morphological abnormalities of the skeleton or heart. Given that the spatiotemporal expression patterns of mRor1 and mRor2 mostly overlap during development (16), we investigated whether the loss of mRor1 function can be compensated for by mRor2 in mRor1−/− mice. To determine whether mRor1 interacts genetically with mRor2 during mouse development, we generated mRor1/mRor2 double mutants. Interestingly, the double mutants exhibited defects in the skeletal and cardiac systems similar to but more severe than those observed in the single mRor2 mutants. Furthermore, the double mutant mice exhibited several defects not found in either the mRor1 or mRor2 single mutants, namely, defects in the sternum, dysplasia of the symphysis of the public bone, and complete transposition of the great arteries. Analyses of these mutant mice indicate that mRor1 and mRor2 are functionally redundant and that mRor1 and mRor2 interact genetically in skeletal and cardiac development.