Biomedical subjects

Yuichiro Otsuka

Publications and source records attributed to Yuichiro Otsuka.

7 recordsLinked to original sources

PubMed2005

Efficient production of 2-pyrone 4,6-dicarboxylic acid as a novel polymer-based material from protocatechuate by microbial function.

Sphingomonas paucimobilis SYK-6, which can degrade various low molecular weight compounds derived from plant polyphenols such as lignin, lignan, and tannin, metabolizes these substances via 2-pyrone-4,6-dicarboxylic acid (PDC). We focused on this metabolic intermediate as a potential raw material for novel, bio-based polymers. We cloned the ligAB and ligC genes of SYK-6, which respectively encode protocatechuate 4,5-dioxygenase and 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase, into a broad host range plasmid vector, pKT230MC. The resulting plasmid, pDVABC, was introduced into the PpY1100 strain of Pseudomonas putida, and we found that PDC could be stably produced from protocatechuate and accumulated. In addition, we examined the efficiency of production of PDC from protocatechuate on a 5-L scale in a Luria-Bertani medium containing 100 mM glucose and determined that PDC was stably produced from protocatechuate to yield 10 g/L or more.

Bacterial Proteins↗

PubMed2005

Hepatic arterial cannulation using the side holed catheter.

BACKGROUND: Hepatic arterial infusion chemotherapy (HAIC) has been recognized as one of the effective treatments for patients with hepatic metastatic tumor. However it is difficult to perform HAIC in the long term without complications. This report describes the laparotomic approach using the side holed catheter, which is a novel method of implanting a catheter-port system. METHODS AND RESULTS: We designed a new anti-thrombotic catheter for HAIC. This catheter is tapered from 5F (diameter of shaft) to 3.3F (diameter at tip), and a side hole is opened 7 cm from the tip of catheter. This catheter is inserted from the gastroduodenal artery to the common hepatic artery (CHA), and the tip is put in the aorta or in the splenic artery. The side hole is adjusted distal to the CHA. In our surgical department, our new catheter was inserted in four patients at the time of their abdominal surgery. The cannulation was performed successfully in all patients. In two of them, HAIC was finished without problems at 6 months after starting, and two were still treated by HAIC at 9 and 8 months after starting. CONCLUSIONS: Initial results from a study of a new method of implanting a catheter-port system in the hepatic artery using the new tapering side hole catheter suggest that this method may enable operators to avoid complicated selective coiling and may lower the incidence of hepatic artery occlusion in patients receiving long-term HAIC.

Aged↗

PubMed2005

Laparoscopic liver resection of hepatocellular carcinoma.

BACKGROUND: We have continued to develop laparoscopic hepatectomy as a means of surgical therapy for hepatocellular carcinoma (HCC). METHODS: We evaluated the degree of invasiveness and analyzed the outcomes of laparoscopic hepatectomy compared with open hepatectomy for HCC. RESULTS: There were notable differences with respect to blood loss and operating time compared with open hepatectomy cases. Patients started walking and eating significantly earlier in the laparoscopic hepatectomy group, and these more rapid recoveries allowed shorter hospitalizations. On the Estimation of Physiologic Ability and Surgical Stress (E-PASS) scoring system, there was no difference in preoperative risk. However, a significant difference was seen in the surgical stress and comprehensive risk scores between the open hepatectomy and laparoscopic hepatectomy groups. Concerning the survival rate and disease-free survival rate, there were no significant differences between procedures. CONCLUSIONS: Laparoscopic hepatectomy avoids some of the disadvantages of open hepatectomy and is beneficial for patient quality of life (QOL) as a minimally invasive procedure if the operative indications are appropriately based on preoperative liver function and the location and size of HCC.

Aged↗

PubMed2005

[Cryotherapy of the resection edge after hepatectomy of colorectal liver metastases].

Obtaining a one-centimeter negative margin is an important factor in preventing disease recurrence after surgery for hepatic tumors. Cryotherapy of the resected edge has been used to achieve optimal margin clearance in cases in which the alternative would be an extended high-risk liver resection. As a concrete method, cryotherapy was delivered with a liquid nitrogen based compact system (CRY-AC, Brymill Co., USA). The resection edge with involved or inadequate resection margins was ablated directly by using the flat probe for 3 minutes per 1 place. Between 2002 and present, a total of 14 patients with colorectal liver metastases underwent edge cryotherapy. Although there was no hemorrhage from the stump, postoperative leak of the bile and stump recurrence were recognized in each patient. Since cryotherapy has features that make the vascular difficult to be damaged, the complication was not recognized in the patient with exposed vascular in the resected edge. By extending the follow-up period, we want to examine whether the edge recurrence could be controlled or not.

Colorectal Neoplasms↗

PubMed2004

Laparoscopy-assisted spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein.

Herein, we report the successful performance of a laparoscopy-assisted spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein for a patient with pancreatic cystadenoma, as a minimally invasive procedure with the preservation of function. The laparoscopy-assisted distal pancreatectomy procedure involved detaching the spleen and the distal pancreas from the retroperitoneum by a hand-assisted procedure, removing them from the peritoneal cavity through a small incision, and detaching the distal pancreas by ligating and transecting the short gastric artery and vein and the branches of the splenic artery and vein, while the spleen and main splenic artery and vein were preserved under direct view. The pancreatic parenchyma was transected with a stapling device (TL-30), and continuous suturing was added to the resected margin. The patient's postoperative course was uneventful; the patient started to eat and walk on postoperative day 2 and was discharged on day 8. It is considered that the combination of hand-assisted and laparoscopy-assisted distal pancreatectomy, with conservation of the splenic artery and vein, is a minimally invasive and clinically useful technique for treating tumors of cystic disease of the pancreas with low-grade malignant potential, or benign solitary neuroendocrine tumors.

Adult↗

PubMed2004

Hepatic resection using stapling devices.

BACKGROUND: The progress and development of stapling devices has been remarkable. They have become indispensable for gastrointestinal diseases and are increasingly utilized in laparoscopic operations. Liver surgery applications for this technique are continuing to emerge, and in this study, we introduced the use of stapling devices to hepatic surgery. METHODS: We examined the operative procedure and efficacy of hepatic resections using stapling devices as follows: transection of Glisson's pedicle and the hepatic vein using endolineal stapling devices in right and left lobectomies; bisegmentectomy II and III en masse using a stapling device; and application of endolineal stapling devices to vessel transections and dissections of the hepatic parenchyma in laparoscopic hepatectomies. RESULTS: It was considered useful to tactfully apply stapling devices to vessel transections and dissections of the hepatic parenchyma in order to simplify the operative procedures of right or left lobectomies and lateral segmentectomies. Furthermore, the use of endoscopic stapling devices was an acceptable alternative to vessel transactions and dissections of the hepatic parenchyma in laparoscopic hepatectomies. CONCLUSIONS: We believe that stapling devices will become utilized in liver surgery hereafter.

Hepatectomy↗

PubMed2003

Detection and characterization of a novel extracellular fungal enzyme that catalyzes the specific and hydrolytic cleavage of lignin guaiacylglycerol beta-aryl ether linkages.

Cleavage of the arylglycerol beta-aryl ether linkage is the most important process in the biological degradation of lignin. The bacterial beta-etherase was described previously and shown to be tightly associated with the cellular membrane. In this study, we aimed to detect and isolate a new extracellular function that catalyses the beta-aryl ether linkage cleavage of high-molecular lignin in the soil fungi. We screened and isolated 2BW-1 cells by using a highly sensitive fluorescence assay system. The beta-aryl ether cleavage enzyme was produced by a newly isolated fungus, 2BW-1, and is secreted into the extracellular fraction. The beta-aryl ether cleavage enzyme converts the guaiacylglycerol beta-O-guaiacyl ether (GOG) to guaiacylglycerol and guaiacol. It requires the C alpha alcohol structure and p-hydroxyl group and specifically attacks the beta-aryl ether linkage of high-molecular mass lignins with addition of two water molecules at the C alpha and C beta positions.

Catalysis↗