Carcinoma of the pancreatobiliary system often produces perineural invasion extending to extrabiliary and extrapancreatic sites. A surgical technique has been developed to manage this invasion and has been used since 1974. Serial sections were prepared from 90 resected specimens and examined for perineural involvement of intramural and extramural biliary plexuses as well as the pancreatic nerve plexus. Perineural invasion was seen in 34 of 40 patients with carcinoma of the common bile duct, in ten of 14 with cancer of the gallbladder and in four of 15 with carcinoma of the papilla of Vater. Invasion extended to the extramural biliary or pancreatic nerve plexuses in 24 of 40 patients with carcinoma of the bile duct. Involvement of the intrapancreatic nerves was seen in all 21 patients with carcinoma of the pancreatic head and that of the pancreatic nerve plexus in 17 of 21. Perineural invasion was often found at the most progressive margin of the tumour. The survival rate of patients with perineural invasion was low compared with that of those without such invasion, although survival of patients with perineural invasion tended to be longer after extensive resection. The perineural space should be regarded as an important route for the spread of pancreatic and biliary carcinoma.
The lymphatic pathway from the head of the pancreas to the para‐aortic lymph nodes was examined on the basis of the frequency of lymph node involvements. Forty‐four patients were examined. All patients had extended radical operations. Thirty‐one of 44 (70.5%) patients had lymph node involvement. The lymph nodes that had a high metastatic rate included the following: (1) lymph nodes around the common hepatic artery (number 8 lymph node); (2) lymph nodes of the hepatoduodenal ligament (number 12 lymph node); (3) the posterior pancreaticoduodenal lymph node (number 13 lymph node); (4) lymph nodes around the superior mesenteric artery (number 14 lymph node); (5) para‐aortic lymph nodes (number 16 lymph node); and (6) the anterior pancreaticoduodenal lymph node (number 17 lymph node). Twenty‐eight of these 31 patients had disease in the posterior pancreaticoduodenal lymph node. The patterns of lymph node involvement consisted of four combinations: number 13‐number 17, number 13‐number 14, number 14‐number 16, and number 17‐number a. All of the patients with number 16 nodal involvement had number 14 lymph node metastasis. However, there was no relationship between tumor size and lymph node involvement. Based on these results, the main lymphatic pathway from the head of the pancreas to the para‐aortic lymph nodes was thought to be via the lymph nodes around the superior mesenteric artery, assuming that lymphatic flow is anterograde. In addition, this study demonstrates that it is necessary to perform an extensive lymph node dissection, including the para‐aortic lymph node, even in patients with small tumors.
The biochemical interactions between the Cdk2/Cyclin E kinase and its inhibitor p27, were investigated using purified, recombinant p27 and CAK-phosphorylated Cdk2/Cyclin E. From kcat/Km determinations using either histone H1 or pRb as substrates, we found that Cdk2/Cyclin E has 60-fold higher specificity for pRb than for histone H1. The IC50 value of p27 increased with increasing Cdk2/Cyclin E concentrations while it remained constant at various ATP and histone H1 concentrations, suggesting that p27 acts as a tight binding inhibitor of Cdk2/Cyclin E. We also found that p27 could be phosphorylated by Cdk2/Cyclin E only at high enzyme concentrations, and that p27 forms a stable interaction with Cdk2/Cyclin E regardless of its phosphorylation state. Our results further indicate that the Cdk2/Cyclin E/p27 ternary complex is kinetically inactive as an enzyme; instead it serves as a substrate for Cdk2/Cyclin E. These results suggest that if phosphorylation of p27 by Cdk2/Cyclin E is involved in its ubiquitin-dependent degradation, as previously suggested, then the target for such event is the phosphorylated p27 bound to Cdk2/Cyclin E and not free p27.
Methotrexate (MTX), a folic acid antagonist, is widely used in the treatment of neoplasms, psoriasis and rheumatoid arthritis. Despite its efficacy, MTX sometimes finds limited application because of its adverse effects, including renal or liver impairment, bone marrow toxicity and gastrointestinal mucosal injury. Intestinal mucositis, bleeding and peptic ulcers are well-known gastrointestinal adverse effects of MTX, although cases of fatal mucosal necrosis induced by MTX are extremely rare. Here, we report the case of an 82-year-old Japanese woman who developed severe gastrointestinal mucosal necrosis after 8 years of treatment with low-dose MTX (8 mg/week). In the drug lymphocyte stimulation test, MTX showed a strong positive reaction, with a stimulation index of 443% against normal controls. Physicians must be aware of potential drug-induced adverse effects in patients with chronic diseases who are on long-term medication.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.