Aphidicolin-resistant DNA polymerase of bacteriophage phi 29 APHr71 mutant is hypersensitive to phosphonoacetic acid and butylphenyldeoxyguanosine 5'-triphosphate

Bacteriophage phi 29 DNA polymerase is sensitive to aphidicolin (APH). DNA polymerase of the APH-resistant mutant, APHr71, was more sensitive to phosphonoacetic acid and butylphenyldeoxyguanosine 5'triphosphate than the wild type. Nucleotide sequence analysis revealed a single transition of G at nucleotide 562 to A in the DNA polymerase gene of APHr71, indicating that APHr71 DNA polymerase (572 residues) had a single amino acid substitution from glycine at residue 188 to serine. The results suggest that the site and the neighboring conserved segment of phi 29 DNA polymerase constitute a structure interacting with deoxynucleotides, pyrophosphate, and APH.     

Adenosquamous carcinoma of the pancreas: preoperative diagnosis and molecular alterations

Adenosquamous carcinoma of the pancreas is a rare tumor which has a less favorable prognosis than common ductal cell carcinoma of the pancreas, and a definite preoperative diagnosis of this tumor is quite difficult. We herein report two cases of this rare variant. The patients were a 41-year-old man (patient 1) and a 67-year-old woman (patient 2). Patient 1 had a hypoechoic mass measuring 3cm in the uncus of the pancreas, while patient 2 had a huge mass, measuring 8cm, in the tail of the pancreas. Patient 2 was successfully diagnosed preoperatively as having an adenosquamous carcinoma, by cytological examination of the pure pancreatic juice obtained by endoscopic retrograde pancreatic juice aspiration. A pylorus-preserving pancreatoduodenectomy was performed for patient 1, and a distal pancreatectomy with resection of the spleen and the left kidney was performed for patient 2. Subsequent pathological findings of these two tumors revealed adenosquamous carcinoma of the pancreas. K-ras point mutation, p53 overexpression, and telomerase activity in both tumor specimens were detected by the mutant allele specific amplification method, immunohistochemical staining, and telomeric repeat amplification protocol assay, respectively. The two patients died of recurrent disease 5 and 4 months, respectively, after surgery. Cytological examination of pure pancreatic juice is a useful modality for the preoperative diagnosis of this tumor, and frequent molecular alterations may be associated with the poor prognosis of adenosquamous carcinoma of the pancreas.     

Clinical predictors of recurrence site after hepatectomy for metastatic colorectal cancer

BACKGROUND/AIMS: Surgical resection of hepatic colorectal metastasis may produce long-term survival and cure; however, a significant proportion of patients will have intrahepatic and/or extrahepatic recurrence with a poor prognosis. The aim of this study was to define clinical predictors of recurrence site after hepatectomy in terms of stratifying patients for adequate adjuvant trials to improve the prognosis. METHODOLOGY: Clinical, pathologic, and outcome data for 70 consecutive patients undergoing hepatectomy for colorectal metastasis isolated to the liver were reviewed retrospectively, and all data were analyzed by the logistic multivariate regression model. RESULTS: Recurrence in the remnant liver was seen in 60% of patients, and recurrence in the lung was found in 34% of patients. Number of liver tumors was the only significant and independent predictor of recurrence in the remnant liver (P = 0.048). All patients with three or more tumors experienced recurrence. Location of liver tumors lying adjacent to the hepatic vein, which was confirmed by preoperative imaging techniques, was the only significant and independent predictor of recurrence in the lung (P = 0.020). CONCLUSIONS: Number and location of liver tumors would be the significant and independent clinical predictors of recurrence site after hepatectomy for metastatic colorectal cancer. This might be useful for justification and selection of effective adjuvant trials after surgery.     

Pancreatic adenocarcinoma in a patient with Peutz-Jeghers syndrome: report of a case and literature review

We present a rare case of pancreatic adenocarcinoma in a 47-year-old man with the Peutz-Jeghers syndrome. The patient underwent pancreatoduodenectomy with partial resection of the portal vein. We also review the current literature concerning Peutz-Jeghers syndrome associated with malignant tumors, especially pancreatic cancer. To our knowledge, this is the first report of a Peutz-Jeghers syndrome patient with pancreatic cancer having pancreatoduodenectomy and pathologically diagnosed with invasive ductal adenocarcinoma of the pancreas. The Peutz-Jeghers syndrome patients with pancreatic cancer were relatively young. As the pancreatic cancer in these patients was advanced and most were unresectable at diagnosis, the prognoses of these patients were extremely poor. Surgical resection offers the only chance for cure or long-term survival for Peutz-Jeghers syndrome patients, if the tumor is localized without distant metastasis. Therefore, screening even for young patients with Peutz-Jeghers syndrome is necessary for early detection of cancer.     

Repeat liver resection for hepatocellular carcinoma

BACKGROUND: Although hepatectomy has been accepted as a therapeutic option for the primary tumor of hepatocellular carcinoma (HCC), what role the second liver resection will play in the clinical care of patients with intrahepatic recurrence of HCC after the initial resection has not been well evaluated. STUDY DESIGN: In a retrospective review of the 6-year period between January 1991 and December 1996, records were examined of 94 patients who underwent curative liver resection for HCC. Of these, 57 patients had isolated recurrent disease to the liver; 12 of the 57 patients underwent repeat surgical resection and 45 patients received nonsurgical ablative therapy. Clinical data for these patients were reviewed for operative morbidity and mortality, survival, disease-free survival, and pattern of failure. RESULTS: There were no perioperative deaths during repeat liver resections for recurrent HCC. Operative morbidity in the second resection was comparable to the initial resection. The disease-free survival rate after the second hepatectomy was 31% at 2 years, significantly lower than that after initial hepatectomy (62%) (p = 0.009). The overall survival rate after the second hepatectomy was 90% at 2 years, in contrast to 70% after nonsurgical ablative treatment for recurrent HCC (p = 0.253). CONCLUSIONS: Although the second liver resection for recurrent HCC can be performed safely and may improve survival, the disease-free survival rate after such resection therapy is low. This likelihood of further recurrences encourages studies for the selection of patients who may benefit from repeat liver resection.