Possible key residues that determine left gastric artery blood flow response to PACAP in dogs

AIM:To determine the effect of pituitary adenylate cy-clase-activating polypeptide (PACAP) on left gastric artery (LGA) flow and to unveil the structural or functional important sites that may be critical for discrimination of different receptor subtypes. METHODS: Peptides, including PACAP-27, PACAP-38, amino acid substituted PACAP-27 and C-terminus truncated analogues PACAP (27-38), were synthesized by a simultaneous multiple solid-phase peptide synthesizer. Flow probes of an ultrasound transit-time blood flowmeter were placed around the LGA of beagle dogs. Whenpeptides were infused intravenously, the blood flow was measured.RESULTS: [Ala4, Val5]-PACAP-27 caused a concentration-dependent vasodepressor action which was similar to that caused by PACAP-27. The LGA blood flow response to [Ala4, Val5]-PACAP-27 was significantly higher than that to PACAP-27, which was similar to that to vasoactive intestinal polypeptide (VIP) at the same dose. [Ala6]-PACAP-27 did not increase the peak LGA ? ow. [Gly8]-PACAP-27 showed a similar activity to VIP. [Asn24, Ser25, Ile26]-PACAP-27 did not change the activity of peptides at all doses. CONCLUSION: NH2 terminus is more important to biological activity of peptides and specifi c receptor recognition than COOH-terminus.

Retrograde embolization technique of the right gastric artery during the implantation of port-catheter system for hepatic arterial infusion chemotherapy

Objective:This study aimed to introduce and evaluate a new embolization technique for the right gastric artery(RGA) during percutaneous implantation of a port-catheter system for hepatic arterial infusion chemotherapy(HAIC).Methods:From January 2013 to January 2017,159 patients with unresectable advanced liver cancer underwent percutaneous implantation of a port-catheter system.In 86 of these patients(56 men;aged 28-88 years;mean:60.6±12.0 years),in whom the RGA was obvious on arteriography,embolization of RGA was attempted using microcoils to protect the gastric mucosa during HAIC.In the first phase(first three years),antegrade embolization of the RGA using a 2.7 Fr microcatheter was performed in 55 patients.In the second phase(next two years),embolization of the RGA was attempted by combining antegrade embolization and retrograde embolization through the left gastric artery(LGA) in 31 patients.The success rates and the incidence of acute gastroduodenal mucosal toxicity(AGMT) in these two groups were compared.Results:The total success rate of the RGA embolization was 70.9%.The success rate was 83.9% in 31 patients who underwent combined antegrade and retrograde embolization,which was significantly higher than that of antegrade embolization alone(63.6%) performed in 55 patients(p=0.047).No complications related to embolization of RGA were documented.The incidence of AGMT was 29.1%(16/55) in patients in the first phase,which was significantly higher than that in the patients in the second phase(9.7%,3/31)(p=0.037).Conclusion: A combination of retrograde embolization via LGA could increase the success rates of RGA embolization and reduce the incidence of AGMT after HAIC.

Angiographic Findings of Extrahepatic Branches Originating from Hepatic Artery and Its Clinical Significance

Objective： To observe the presentation and variation of extrahepatic branches originating from hepatic artery by hepatic arteriography. Methods： Hepatic arteriogram of 200 cases with unresectable hepatic primary or metastatic tumors before interventional therapy were retrospectively analyzed. Two interventional radiologists independently reviewed the type, originating artery, distribution and variation of extrahepatic artery. Results： Five types of extrahepatic artery were found, with the most common type of the right gastric artery （n=156, 78%）, followed by the cystic artery （n=126, 63%）, accessory left gastric artery （n=19, 9.5%）, hepatic falciform artery （n=5, 2.5%）, and accessory left inferior phrenic artery （n=4, 2%）. In 188 cases, there were extrahepatic arteries derived from hepatic proper artery or its branches, and the most frequent originating site was the right hepatic artery （130 extrahepatic branches）, followed by the proper hepatic artery （103 branches）, left hepatic artery （56 branches） and middle hepatic artery （3 branches）. The left hepatic artery was the arising site with the multiple types of extrahepatic branches including all above branches except the cystic artery. Conclusion： Many types of extrahepatic branches usually derive from the hepatic artery or its distal branches, and its originating sites are not constant. It is important to avoid damage of extrahepatic tissue during interventional therapy for liver tumors.