OBJECTIVETo investigate role of exocrine cells in the pancreatic enhancement images at Manganese (II) N, N'-dipyridoxylethlenediamine-N, N'-diacetate 5, 5'-bisc (Mn-DPDP)-enhanced magnetic resonance (MR) imaging.

METHODSArtificial pancreatic leakage was constructed in six dogs using a fistula tube inserted into the duodenum papillae. Pancreatic juice was collected before and after intravenous infusion of 2 ml/kg of Mn-DPDP at a rate of 2 - 3 ml/min. The Mn content of pancreatic juice was measured by atomic absorption spectroscopy. T(1)-weighted spin-echo images and T(1)-weighted spoiled phase gradient-echo (SPGR) images were obtained prior and approximately 30 min after the administration of Mn-DPDP at 1.5T.

RESULTSThe Mn content of pancreatic secretion increased 60.47 +/- 21.83 micro g/dl after the administration of Mn-DPDP (t = 6.785, P < 0.01). The signal/noise ratio (S/N) of the pancreas increased 53 percent +/- 49 percent and 62 percent +/- 44% on T(1)W spin echo images and SPGR images, respectively.

CONCLUSIONSExocrine cells of the pancreas can absorb manganese and excrete it through the pancreatic juice. Exocrine cells play an important role in the enhancement of the pancreas in MR imaging with Mn-DPDP.

Animals ; Contrast Media ; Dogs ; Edetic Acid ; analogs & derivatives ; pharmacokinetics ; Image Enhancement ; Magnetic Resonance Imaging ; Manganese ; pharmacokinetics ; Pancreas ; anatomy & histology ; metabolism ; Pyridoxal Phosphate ; analogs & derivatives ; pharmacokinetics

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumors in the gastrointestinal tract. Though surgical resection is the only radical treatment, postoperative recurrence and metastasis often occur. The first-line therapy for the treatment of recurrent, metastatic and unresectable GIST is imatinib. More than 80% of patients can benefit from imatinib treatment, but half of patients will still have recurrence or metastasis within 2 years after treatment initiation, and secondary drug resistance is a major cause of disease progression. Therefore, adeep understanding of the mechanisms of secondary drug resistance will guide us to develop personalized therapeutic schedule in the future. This article describes the mechanism of IM secondary resistance from the aspects of gene alteration, abnormal activation of signal transduction pathway, autophagy, apoptosis and drug concentration. It is found that single drug therapy has certain limitations in patients with secondary resistance to IM. Using IM combined with downstream signaling molecule inhibitors, autophagy inhibitors, insulin-like growth factor 1 receptor (IGF-1R) inhibitors, heat shock protein 90 (HSP90) inhibitors, cytotoxic T lymphocyte - associated antigen - 4 (CTLA - 4) antibodies and mitochondrial inhibitors provide us new therapeutic ideas. However, these combination treatments are still in the research phase, and further trials are needed to confirm the safety and efficacy. With the gradual deepening of research on drug resistance mechanisms, it will provide more solutions to the current serious drug resistance problem.

As tumors originated from mesenchymal tissue, gastrointestinal stromal tumors (GIST) has its own typical history. For the idea of treatment for GIST at different historical periods, the role and value of surgery for the treatment of GIST keep changing. Laparoscopy and endoscopy will have the role they deserved. With the understanding of pathogenesis of GIST, targeted chemotherapy will be more and more accurate and individualized. How to improve the overall therapeutic effect of GIST, especially for the patients with the high risk and drug-resistance, is the dilemma and challenges for the surgeons.

The incidence of small and micro gastrointestinal stromal tumors is increasing significantly because of the enhanced health consciousness and advanced endoscopic technology. But there still is controversial in the biological behavior and clinical treatment of GIST. The treatment of the GIST with endoscopic technology has obvious advantages. This method can remove tumor and avoid significant trauma. In this paper, the biological behavior, clinical evaluation and endoscopic treatment of the GIST are discussed.
Endoscopy, Gastrointestinal ; Gastrointestinal Neoplasms ; Gastrointestinal Stromal Tumors ; Humans

With the promotion of standard radical resection of gastric cancer, the incidence of postoperative pseudoaneurysm is significantly increasing. Both the patient's own factors and iatrogenic factors are accoutable. Surgeons should clarify the causes of pseudoaneurysm, pay attention to the clinical symptoms and signs, and treat the patients appropriately. In order to avoid the occurrence of postoperative pseudoaneurysm, surgeons should carefully evaluate the preoperative conditions, perform precision operation and reduce the morbidity of postoperative infection and fistula.
Aneurysm, False ; prevention & control ; Gastrectomy ; Humans ; Incidence ; Morbidity ; Postoperative Complications ; prevention & control ; Stomach Neoplasms ; surgery

With the increasing incidence of early gastric cancer, endoscopic treatment has been widely used. It has also played an important role in the diagnosis and treatment of gastric cancer. Therefore, it is very important to carry out standardized treatment with endoscopy. In theory, endoscopic resection can be performed in early gastric cancers which have no lymph node metastasis and also can be resected completely. Endoscopic therapy is absolutely indicated in macroscopically intramucosal differentiated carcinomas (pT1a) without ulcer or ulcer scar and with diameter ≤2 cm. The expanded indications are: (1) macroscopically intramucosal differentiated carcinomas (pT1a) without ulcer and with diameter >2 cm; (2) macroscopically intramucosal differentiated carcinomas (pT1a) with ulcer and with diameter ≤2 cm; (3) macroscopically intramucosal undifferentiated carcinomas (pT1a) without ulcer and with diameter ≤2 cm. Methods of preoperative evaluation include endoscopy, CT, and endoscopic ultrasonography (EUS). For tumor size greater than 3 cm and undifferentiated lesions, evaluation should be carried out carefully in order to avoid the underestimation of T staging. During endoscopic surgery, the extent, nature, and depth of the lesion should be clearly defined again, if necessary, assisted by staining endoscopy. In order to avoid complications such as bleeding and perforation, stanch bleeding and aspiration of gas should be performed promptly during the operation. After endoscopic resection, when pathology reveals positive margin of resected specimen, lesions invading deep submucosa, vascular involvement or peri-gastric lymph node metastasis, additional surgery should be recommended. Even if the patients have been evaluated as radical treatment, close follow-up is still necessary. Only when surgeons strictly obey the indications of endoscopic treatment, make the accurate evaluations for the patients before operation, undergo endoscopic operation carefully, and perform the follow up closely, the patients can be benefit from endoscopic therapy really.

The incidence of small and micro gastrointestinal stromal tumors is increasing significantly because of the enhanced health consciousness and advanced endoscopic technology. But there still is controversial in the biological behavior and clinical treatment of GIST. The treatment of the GIST with endoscopic technology has obvious advantages. This method can remove tumor and avoid significant trauma. In this paper, the biological behavior, clinical evaluation and endoscopic treatment of the GIST are discussed.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumors in the gastrointestinal tract. Though surgical resection is the only radical treatment, postoperative recurrence and metastasis often occur. The first?line therapy for the treatment of recurrent, metastatic and unresectable GIST is imatinib. More than 80% of patients can benefit from imatinib treatment, but half of patients will still have recurrence or metastasis within 2 years after treatment initiation, and secondary drug resistance is a major cause of disease progression. Therefore, adeep understanding of the mechanisms of secondary drug resistance will guide us to develop personalized therapeutic schedule in the future. This article describes the mechanism of IM secondary resistance from the aspects of gene alteration, abnormal activation of signal transduction pathway, autophagy, apoptosis and drug concentration. It is found that single drug therapy has certain limitations in patients with secondary resistance to IM. Using IM combined with downstream signaling molecule inhibitors, autophagy inhibitors, insulin?like growth factor 1 receptor (IGF?1R) inhibitors, heat shock protein 90 (HSP90) inhibitors, cytotoxic T lymphocyte ? associated antigen ? 4 (CTLA ? 4) antibodies and mitochondrial inhibitors provide us new therapeutic ideas. However, these combination treatments are still in the research phase, and further trials are needed to confirm the safety and efficacy. With the gradual deepening of research on drug resistance mechanisms, it will provide more solutions to the current serious drug resistance problem.

The incidence of small and micro gastrointestinal stromal tumors is increasing significantly because of the enhanced health consciousness and advanced endoscopic technology. But there still is controversial in the biological behavior and clinical treatment of GIST. The treatment of the GIST with endoscopic technology has obvious advantages. This method can remove tumor and avoid significant trauma. In this paper, the biological behavior, clinical evaluation and endoscopic treatment of the GIST are discussed.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumors in the gastrointestinal tract. Though surgical resection is the only radical treatment, postoperative recurrence and metastasis often occur. The first?line therapy for the treatment of recurrent, metastatic and unresectable GIST is imatinib. More than 80% of patients can benefit from imatinib treatment, but half of patients will still have recurrence or metastasis within 2 years after treatment initiation, and secondary drug resistance is a major cause of disease progression. Therefore, adeep understanding of the mechanisms of secondary drug resistance will guide us to develop personalized therapeutic schedule in the future. This article describes the mechanism of IM secondary resistance from the aspects of gene alteration, abnormal activation of signal transduction pathway, autophagy, apoptosis and drug concentration. It is found that single drug therapy has certain limitations in patients with secondary resistance to IM. Using IM combined with downstream signaling molecule inhibitors, autophagy inhibitors, insulin?like growth factor 1 receptor (IGF?1R) inhibitors, heat shock protein 90 (HSP90) inhibitors, cytotoxic T lymphocyte ? associated antigen ? 4 (CTLA ? 4) antibodies and mitochondrial inhibitors provide us new therapeutic ideas. However, these combination treatments are still in the research phase, and further trials are needed to confirm the safety and efficacy. With the gradual deepening of research on drug resistance mechanisms, it will provide more solutions to the current serious drug resistance problem.