Showing papers by "Susumu Kobayashi published in 1999"

P16INK4a expression adenovirus vector to suppress pancreas cancer cell proliferation.

Abstract: The prognoses of pancreatic cancer patients have been miserable even after radical surgery, and adjuvant therapy is necessary to improve the surgical results. p16(INK4a) (p16) is tight-binding and inhibitory protein for cyclin-dependent kinase 4 to induce G1 arrest of the cell cycle. p16 gene deletion is frequently identified in human pancreas cancer. The impaired gene function of p16 might be a major factor of the uncontrolled proliferation and malignancy of pancreas cancer cells. In this study, we investigated the effect of adenovirus p16 expression vector for pancreas cancer cell proliferation to clarify whether the vector might be a promising mode to assist the surgical therapy for pancreas cancer. We constructed the adenovirus p16 expression vector AdexCACSp16 by inserting p16 cDNA to a cassette cosmid containing a nearly full-length adenovirus type 5 genome with E1 and E3 deletions. Thereafter, we assessed the activity of AdexCACSp16 to induce p16 gene mRNA expression in pancreas cancer cell line MIAPaCa-2 and to control cell proliferation. AdexCACSp16 induced a high level of p16 gene mRNA expression in MIAPaCa-2 cells with 1 h contact to the cells. The cell proliferation was significantly suppressed by AdexCACSp16 compared with the control adenovirus group. These data indicate that AdexCACSp16 has the potential to induce p16 gene expression and control pancreas cancer cell proliferation and that the adenovirus p16 expression vector AdexCACSp16 might be a possible method of gene therapy to improve the surgical therapeutic results for pancreas cancer.

The p53 gene mutation is of prognostic value in esophageal squamous cell carcinoma patients in unified stages of curability.

Abstract: Background: The p53 gene alteration is identified in approximately half of all human tumors, and is now thought to be a key gene for regulating the cell cycle through the induction of p21WAF1/CIP1 and inducing apoptosis through some genes such as BAX. In this study, we investigated the prognostic value of p53 mutation for postoperative esophageal squamous cell carcinoma patients. Methods: The subjects studied were 42 esophageal squamous cell carcinoma patients who underwent esophagectomy with complete curability in our department. The cases were limited to stage II and III. DNA was extracted from paraffin-embedded tissues. A p53 gene mutation was detected by polymerase chain reaction-single strand conformation polymorphism and subsequent direct sequencing method for exons 5 to 9. The 5-year survival rate was calculated and statistically compared between the p53 mutation(+) and (−) groups by the log rank test. Results: The p53 gene mutation was identified in 14 cases (33.3%). The 5-year survival rate of the p53 mutation(−) group (n = 28) was significantly higher than the (+) group (n = 14; 51.0% versus 35.7%, P <0.05 by the log rank test). Recurrence could be identified in 10 of 14 p53 mutation(+) cases (71.4%), whereas it was found in 12 of 28 (−) cases (42.8%). Conclusion: The current study indicated that p53 mutation of tumor tissues might be a prognostic factor for esophageal squamous cell carcinoma cases and one of the risk factors for its recurrence.

Ultrasonographic assessment of the risk of injury to branches of the middle hepatic vein during laparoscopic cholecystectomy

Abstract: Background: Although hemorrhage from the gallbladder bed during laparoscopic cholecystectomy is one of main reasons for conversion to open cholecystectomy, the cause of this life-threatening complication is unclear. Patients and methods: Color Doppler ultrasound was used to examine the cause of venous hemorrhage from the gallbladder bed during laparoscopic cholecystectomy in 4 patients postoperatively and to examine the anatomic relationship between the gallbladder bed and branches of the middle hepatic vein in 50 healthy volunteers. Results: Injury to a large branch of the middle hepatic vein adjacent to the gallbladder bed was diagnosed in all 4 patients. One patient required conversion to open cholecystectomy while the bleeding in 2 patients was immediately controlled by direct pressure with the gallbladder. The branch of the middle hepatic vein was completely adherent to the gallbladder bed in 5 of the 50 volunteers, and in 1 the diameter of the branch was as large as 3.5 mm. In 3 volunteers branches 3.0 to 3.8 mm in diameter traversed as close as 1.0 mm from the gallbladder bed. Conclusions: Patients with large branches of the middle hepatic vein close to the gallbladder bed are at risk of hemorrhage during laparoscopic cholecystectomy and should be identified preoperatively with ultrasound.

Experiment of tele-virtual surgery between Germany and Japan

Abstract: Surgeons in Japan and Germany examined a hepatectomy simulation system as part of an application of tele-virtual surgery and a force feedback device. Using our system, surgeons in each country were able to perform various surgical maneuvers upon the same patient. Surgeons palpated abdominal skin, made electrical scalpel incisions and widened the incision line by using surgical tools in virtual space. The force feedback device conveyed tactile sensations to the user, while surgeons performed a virtual operation. Two graphic workstations of equal capability and force feedback devices were employed in each location. As each workstation communicated only event signals through an ISDN (64Kb) line, it was possible to obtain real time tele-virtual surgery without a large capacity communication infrastructure.

Intrahepatic advance pattern of the solitary liver metastasis from colorectal cancer

Abstract: Intrahepatic advance pattern of solitary metastatic liver tumor from colorectal cancer was considered on the basis of the classification according to pre- and intra-operative information in a series of 33 resected cases at the hospital. Small nodule; less than 3cm in tumor diameter, large nodule; more than 3cm, and proliferat-ing nodule; macroscopic existence of marginal proliferating form were defined, and the tumors were classi-fied into the following three types. 1) Small nodular type (S): both 3- and 5-year survival rates were 38%. Remnant liver recurrence was so high in the synchronously metastasized patients, whereas good prognosis in the metachronously metastasized patients. 2) Large nodular type (L): 3- and 5-year survival rates were 66 %and 54% respectively, and no prognostic difference about the distinction of metastasized period was seen. Mean diameter of the tumors specimen was 4.2±1.7cm (mean±S.D.). 3) Proliferating large nodular type (PL): the prognosis was as extremely poor as 1- and 2-year survivals were 33% and 0% respectively. The diameter of the tumor was 9.2±3.5cm, thus PL was considered as the clinically advanced type of L. We believe, that the intrahepatic advance pattern of solitary metastatic liver tumor from colorectal cancer can be pre-dicted pre- and intraoperatively by our classification, and the prediction is properly useful to the therapeutic planning.