Clinical impact of intraoperative histological examination of the ductal resection margin in extrahepatic cholangiocarcinoma.

BACKGROUND: Although ductal resection margin status in extrahepatic cholangiocarcinoma is evaluated by intraoperative histological examination of frozen sections, its clinical relevance remains controversial. METHODS: Material taken from patients who underwent R0 or R1 resection for extrahepatic cholangiocarcinoma with intraoperative histological examination of the final ductal resection margins between 1994 and 2003 were reviewed. The following histological classification was used: insufficient, negative for malignancy (NM), undetermined lesion (UDL) or positive for malignancy (PM). Multivariable analyses of overall survival and anastomotic recurrence in relation to ductal margin status were performed. RESULTS: Resection material from 363 patients was identified. For the proximal ductal margin, only PM in intramural lesions was significantly associated with poor survival (hazard ratio (HR) 1.72, 95 per cent confidence interval (c.i.) 1.06 to 2.74) and anastomotic recurrence (HR 6.39, 95 per cent c.i. 1.89 to 21.62) compared with NM. In analysis of overall survival according to distal ductal margin status, the HRs for UDL and PM lesions in comparison with NM were not significant. CONCLUSION: PM in intramural lesions found during intraoperative histological examination of the proximal ductal resection margin was related to clinical outcome. This finding favours additional resection of the bile duct. A similar association was not found for histology results of the distal resection margin.

Development of pancreatic cancers during long-term follow-up of side-branch intraductal papillary mucinous neoplasms.

BACKGROUND AND STUDY AIMS: Side-branch intraductal papillary mucinous neoplasms (SB-IPMNs), and associated synchronous and metachronous pancreatic cancers are increasingly detected as imaging modalities become more sensitive. We investigated the natural history of SB-IPMN, and the incidence and characteristics of pancreatic cancers among patients undergoing long-term follow-up. PATIENTS AND METHODS: We reviewed the clinical, imaging, and pathological features in 103 patients, diagnosed at the Aichi Cancer Center between September 1988 and September 2006 as having SB-IPMN, and conservatively followed up for ≥ 2 years (median 59 months) based on an endoscopic ultrasonography (EUS) database. RESULTS: 74 (71.8 %) patients had nonprogressive lesions. Overall, six patients (5.8 %) developed pancreatic cancers during follow-up, with intraductal papillary mucinous (IPM) carcinoma in four, and ductal carcinoma of pancreas that was not IPMN in two patients. Of the six pancreatic cancers, five were diagnosed at a resectable stage. The 5-year and 10-year actuarial rates of development of pancreatic cancer were 2.4 % and 20.0 %, respectively. Although, at the last follow-up, cyst size, main pancreatic duct (MPD) diameter, mural nodule size, and frequency of metachronous and/or synchronous cancers of other organs were significantly higher in patients who developed IPM carcinoma, resected SB-IPMNs without mural nodules and dilated MPDs had no IPM carcinomas. CONCLUSIONS: The frequency of pancreatic cancers is high on long-term follow-up of SB-IPMN. Although conservative management is appropriate for selected patients, regular and long-term imaging, especially by EUS is essential, even if SB-IPMN remains unchanged for 2 years. Presence of mural nodule and dilated MPD seem to be more appropriate indicators for resection than cyst size alone for SB-IPMNs.

Endoscopic submucosal dissection for colorectal tumors: technical difficulties and rate of perforation.

BACKGROUND AND STUDY AIM: Endoscopic submucosal dissection (ESD) for colorectal tumors is not generally recommended because of the technical difficulties and complications, including perforation. These aspects of ESD are thoroughly analyzed in our retrospective study. PATIENTS AND METHODS: We studied 105 colorectal tumors, from 100 patients, that were treated by ESD at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2008. We analyzed tumor size, operation time, rate of en bloc resection, and complications. In addition, we thoroughly investigated the cases of perforation. RESULTS: The average tumor size was 30.4 mm; average operation time, 102 min; and rate of en bloc resection, 88.5 %. Perforation occurred in 10.4 % of the ESD procedures. Of the 11 perforations, 8 were detected during ESD and treated by clip closure during endoscopy, while 3 were evident only on subsequent routine computed tomography (CT); these were also managed conservatively. A case of postoperative hemorrhage was also observed. CONCLUSIONS: ESD effectively achieved a high rate of en bloc resection. However, the perforation rate was substantial; hence, improvement in the ESD method is required. The outcomes of ESD, especially for early colorectal malignancies, need to be assessed further.

Neurogenic tumors in coho salmon (Oncorhynchus kisutch) reared in well water in Japan.

Neurogenic tumors were found protruding from various parts of the body of 23 coho salmon. The tumor-bearing fish were first- or second-generation fish derived from eggs imported at the eyed stage to Japan from the United States. Twenty-two of the tumors were in young adults and varied from 14 to 80 mm in maximum diameter. Histologically, the tumors were composed of spindle-shaped cells with abundant fibrous stroma. One tumor showed typical nuclear palisading. All tumors in young adults invaded locally muscle and adipose tissues. These tumors were similar in histologic appearance to malignant schwannomas in humans. One tumor found in a fingerling coho salmon was identified as an ependymoblastoma. The Vectstain avidin-biotin-peroxidase complex immunoperoxidase staining procedure for S-100 protein revealed that the S-100 protein existed in an ependymoblastoma and in areas of typical nuclear palisading in a malignant schwannoma in coho salmon. The occurrence of soft tissue tumors in coho salmon was first recorded in Japan. The morphology and etiology of the present cases were compared with those of the tumors in salmon reported from the United States. Judging from the conditions in which the fish were reared, the development of these tumors was not related to halogenated compounds formed during water chlorination, as suggested previously. The environmental factor(s) responsible for their development has not yet been identified, and genetic influences may have been a contributory factor.

Genetic instability in pancreatic cancer and poorly differentiated type of gastric cancer.

To examine genetic instability during carcinogenesis, we screened 171 carcinomas of the breast, liver, proximal colon, stomach, pancreas, uterine cervix, and ovary for replication error at four microsatellite marker loci on chromosome 2, 3, and 17. A significantly high incidence of genetic instability was observed in pancreatic (6 of 9 tumors) and gastric cancers (22 of 57 cases). In other types of carcinoma, the incidence of replication error-positive cases was relatively low (3-16%). Among gastric carcinomas, significantly more replication error-positive cases were observed in the poorly differentiated types (16 of 25 cases) than in well differentiated types (3 of 18) (P = 0.0023 by Fisher's exact test). Our results suggested that genetic instability is likely to play an important role in development of pancreatic and gastric cancers, particularly poorly differentiated adenocarcinomas.

High frequency of K-ras mutations in biliary duct carcinomas of cases with a long common channel in the papilla of Vater.

The frequency of K-ras mutation in biliary duct carcinomas in different locations and the relationship to the form of the junction of the pancreaticobiliary duct (JPBD) are not understood clearly. These points were investigated in the present study. Thirty-seven biliary duct carcinomas in patients without anomalous JPBD were investigated for K-ras mutations. Regarding location, 12 were hilar, 4 in the upper, 11 in the middle, and 10 in the lower portion of the duct. Furthermore, with 14 cases for which the form of the JPBD could be confirmed by endoscopic retrograde cholangiopancreatography or postoperative cholangiopancreatography, division was made into two types: those with a long common channel (>5 mm) in the papilla of Vater (type 1, n = 4), and the other with a shorter or nonapparent common channel (type 2, n = 10). The overall frequency of K-ras mutation was 30%, the incidence gradually increasing from upper to lower regions. K-ras mutations were significantly more frequent in biliary duct carcinomas associated with long common channels (P < 0.05). These results suggest that a long common channel may bear a relation to K-ras mutations in biliary duct carcinogenesis, presumably through its influence on pancreatic juice regurgitation.

Frequent c-Ki-ras oncogene activation in mucous cell hyperplasias of pancreas suffering from chronic inflammation.

In order to scrutinize the possible significance of (nonatypical) mucous cell hyperplasia of the pancreas to neoplasia, we analyzed these lesions in terms of c-Ki-ras activation, which is known to be very frequent in pancreatic carcinomas. A total of 16 such mucous cell hyperplasias were collected from 10 pancreases resected for chronic pancreatitis. Tiny tissue fragments were taken from hematoxylin-stained sections by microdissection, and DNA analysis was carried out by the polymerase chain reaction amplification and oligonucleotide hybridization methods. Activating mutations of c-Ki-ras oncogene at codon 12 were detected in 10 of the 16 lesions (62.5%), a high rate as seen in carcinomas. The results indicated a clonal origin of cells comprising the mucous cell hyperplasia suggesting a neoplastic and/or precancerous nature.

The APC gene, responsible for familial adenomatous polyposis, is mutated in human gastric cancer.

Although gastric cancer is the most common cancer in the world, genetic changes during its carcinogenesis are not well understood. Since some gastric cancers are considered to originate from the intestinal metaplasia, it is likely that the adenomatous polyposis coli (APC) gene, the mutation of which causes adenomatous polyps in the colon, is associated with carcinogenesis of gastric cancer. Based on this idea, DNAs isolated from gastric cancers were examined by means of a RNase protection analysis coupled with polymerase chain reaction followed by sequencing of the polymerase chain reaction products. By screening nearly one-half of the coding region of the APC gene in 44 tumors, somatic mutations were detected in three tumors: a missense mutation, a nonsense mutation, and a 5-base pair deletion resulting in a frame shift which causes truncation of the gene product. These results suggest that the mutation of the APC gene also plays an important role during the carcinogenesis of at least some gastric cancers.

Frequent replication errors at microsatellite loci in tumors of patients with multiple primary cancers.

Nearly 10% of cancer patients develop a second primary cancer within 10 years after surgical removal of the first tumor. Hence, detection of a genetic risk for developing multiple primary tumors would be of clinical importance. To investigate whether a genetic defect(s) involving the mismatch repair system constitutes an important risk factor in patients with multiple primary cancers, we examined replication errors (RER) at microsatellite loci in 79 primary cancers which had developed among 38 patients with multiple primary cancers. The RER(+) phenotype was observed at five microsatellite loci on chromosomes 2, 3, 11, or 17 in tumors from 34 (89%) of 38 patients with multiple primary cancers but only in 19 tumors from 174 patients (11%) with a single primary cancer. Our results suggested that: (a) genetic instability may play an important role in development of multiple primary cancers, and (b) testing for RER in a primary cancer may be an appropriate approach to detection of patients at high risk for developing multiple primary cancers.

Genetic diagnosis identifies occult lymph node metastases undetectable by the histopathological method.

The mutant allele-specific amplification (MASA) method is capable of detecting one tumor cell containing genetic changes in a sample containing thousands of normal cells. To investigate whether MASA can be applied to sensitive detection of lymph node metastasis, we screened 22 colorectal cancers for K-ras and p53 mutations and examined corresponding regional lymph node at the genetic level by the MASA method. Six of the primary tumors were found to certain K-ras mutations, and nine exhibited mutations of the p53 gene. In seven of the 14 cases in which genetic alterations were identified (mutations in both genes were found in one tumor), we found discrepancies between the genetic and the histopathological diagnoses with respect to the presence or absence of cancer cells in lymph nodes, in that these patients were histologically diagnosed lymph node negative, hn(-) but genetically diagnosed lymph node positive, gn(+). Because disease recurs in 20-30% of cancer patients whose lymph nodes are histopathologically negative after surgery, genetic evaluation of lymph nodes for metastasis may become a useful prognostic indicator.

Frequent somatic mutations of the APC gene in human pancreatic cancer.

The APC (adenomatous polyposis coli) gene is responsible for familial adenomatous polyposis and is also associated with the development of sporadic tumors of the colon and stomach. To investigate whether or not mutations of APC play any role in tumors arising in other organs, we examined somatic mutations of this gene in sporadic (nonfamilial) renal cell carcinomas, hepatocellular carcinomas, and cancers of the lung and pancreas. DNAs isolated from tumors were examined by means of a RNase protection analysis, coupled with the polymerase chain reaction followed by DNA sequencing of the polymerase chain reaction products. By screening a part of the APC coding region, we detected somatic mutations in four of ten pancreatic cancers; each of these mutations would yield a truncated APC product due to a 1- or 5-base pair deletion. These results imply that mutations in APC contribute to carcinogenesis in the pancreas.

Highly sensitive fluorescence detection of metastatic lymph nodes of gastric cancer with photo-oxidation of protoporphyrin IX.

BACKGROUND: The establishment of a precise and rapid method to detect metastatic lymph nodes (LNs) is essential to perform less invasive surgery with reduced gastrectomy along with reduced lymph node dissection. We herein describe a novel imaging strategy to detect 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence in excised LNs specifically with reduced effects of tissue autofluorescence based on photo-oxidation of PpIX. We applied the method in a clinical setting, and evaluated its feasibility. METHODS: To reduce the unfavorable effect of autofluorescence, we focused on photo-oxidation of PpIX: Following light irradiation, PpIX changes into another substance, photo-protoporphyrin, via an oxidative process, which has a different spectral peak, at 675 nm, whereas PpIX has its spectral peak at 635 nm. Based on the unique spectral alteration, fluorescence spectral imaging before and after light irradiation and subsequent originally-developed image processing was performed. Following in vitro study, we applied this method to a total of 662 excised LNs obtained from 30 gastric cancer patients administered 5-ALA preoperatively. RESULTS: Specific visualization of PpIX was achieved in in vitro study. The method allowed highly sensitive detection of metastatic LNs, with sensitivity of 91.9% and specificity of 90.8% in the in vivo clinical trial. Receiver operating characteristic analysis indicated high diagnostic accuracy, with the area under the curve of 0.926. CONCLUSIONS: We established a highly sensitive and specific 5-ALA-induced fluorescence imaging method applicable in clinical settings. The novel method has a potential to become a useful tool for intraoperative rapid diagnosis of LN metastasis.

Beneficial effects of tissue-type plasminogen activator in acute myocardial ischemia in cats.

Tissue-type plasminogen activator is a new thrombolytic agent that dissolves intravascular thrombi in coronary and peripheral vessels with less pronounced systemic lysis than that produced by streptokinase. Plasminogen activator was shown to induce reperfusion, and to salvage ischemic myocardium, by lysing experimentally induced coronary artery thrombi. The effect of a melanoma cell-derived tissue-type plasminogen activator was studied in cat myocardium rendered ischemic by coronary artery ligation for 2 hours and reperfused for another 4 hours. Plasminogen activator was infused at a rate of 500 IU X kg-1 X min-1 for the first 30 minutes of reperfusion. The marked increase in plasma creatine kinase activity during reperfusion was significantly lower in plasminogen activator-treated cats at 4, 5 and 6 hours, with 7.7 +/- 1.5 X 10(-3) IU X mg protein-1 (n = 8) in the plasminogen activator group versus 17.8 +/- 3.5 X 10(-3) IU X mg protein-1 (n = 7) in the vehicle group at 6 hours (mean +/- SEM). The area at risk in the two ischemic groups was not different, being 14.6 +/- 1.5 and 16.6 +/- 1.4% of total left ventricular mass for the treated and untreated groups, respectively. However, the mass of necrotic tissue determined histochemically was significantly lower in the plasminogen activator-treated group, accounting for 29.5 +/- 3.9% of the area at risk compared with 46.8 +/- 4.2% of area at risk in cats receiving only the vehicle (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet-dependent thrombin generation in patients with hyperlipidemia.

OBJECTIVES: We evaluated coagulability as determined by platelet-dependent thrombin generation in hypercholesterolemic patients before and after treatment with pravastatin and in hypertriglyceridemic patients to investigate the usefulness of coagulability as an index of atherosclerosis and to determine the importance of treating hyperlipidemia. BACKGROUND: An understanding of the interaction between platelets and the plasma coagulation system is important for clarifying the mechanism of the procoagulant process. METHODS: We assessed coagulability in 58 patients with hypercholesterolemia (serum total cholesterol level > or = 220 mg/dl, age 56.5 +/- 1.5 years [mean +/- SEM]), 37 patients with hypertriglyceridemia (serum triglyceride level > or = 200 mg/dl, age 59.5 +/- 1.7 years), 13 patients with hypercholesterolemia plus hypertriglyceridemia (age 51.4 +/- 3.1 years) and 75 normal subjects (age 52.2 +/- 1.7 years). We also studied platelet-dependent thrombin generation in patients with hypercholesterolemia before and after treatment with pravastatin. Calcium chloride was added to 0.5 ml of platelet-rich plasma (150 x 10(9)/liter) to initiate coagulation. Ten microliters of the sample was transferred into 90 microliters of 3.8% sodium citrate at 10-min intervals for 30 min. A chromogenic substrate, S-2238, was added to each sample, and absorbance was measured spectrophotometrically at a wavelength of 405 nm to determine thrombin generation. RESULTS: Platelet-dependent thrombin generation was increased in patients with hypercholesterolemia and patients with hypercholesterolemia plus hypertriglyceridemia (p < 0.01) compared with patients with hypertriglyceridemia and control subjects. Treatment with pravastatin normalized thrombin generation. CONCLUSIONS: Hypercholesterolemia, but not hypertriglyceridemia, was associated with increased platelet-dependent thrombin generation. Pravastatin normalized the generation of thrombin.

Platelet-dependent thrombin generation in patients with diabetes mellitus: effects of glycemic control on coagulability in diabetes.

OBJECTIVES: This study sought to assess the usefulness of platelet-dependent thrombin generation as an index of coagulability in diabetes and to determine the effect of glycemic control on coagulability in diabetes. BACKGROUND: It is important to investigate the interaction of platelets and the coagulation factors to clarify the processes of the coagulation system in detail. METHODS: Platelet-rich plasma (150 X 10(9)/liter), 0.5 ml, was prepared, and 40 mmol/liter of calcium chloride was added to initiate clotting. S-2238 was added to each sample in a microtiter plate every 10 min, and the absorbance of the released color product at 2 min was measured spectrophotometrically at a wavelength of 405 nm using a microtiter plate reader as thrombin generation. We measured the platelet-independent thrombin generation in patients with non-insulin-dependent diabetes mellitus grouped according to glycemic control. RESULTS: Platelet-dependent thrombin generation at 30 min after calcium chloride addition was significantly higher in 23 patients with poorly glycemic-controlled non-insulin-dependent diabetes mellitus without complications, such as diabetic retinopathy, nephropathy and neuropathy (hemoglobin [Hb] A1c >/= 9.0%) than in 46 healthy normal subjects (448 +/- 75 vs. 165 +/- 28 mU/min, p < 0.001). Thrombin generation in 31 well controlled diabetic patients without complications (Hb A1c < 9.0%) was intermediate (240 +/- 72 mU/min) between those of the poorly controlled group and healthy normal subjects. Platelet-poor plasma from diabetic patients increased platelet-dependent thrombin generation in normal subjects. CONCLUSIONS: Coagulability is evidently enhanced in patients with non-insulin-dependent diabetes mellitus compared with that in healthy normal subjects on the basis of assessments of the platelet-dependent thrombin generation, and good glycemic control may help to correct a hypercoagulable state in diabetic patients.

Influence of peripheral intravenous contrast injection on the QRS complex in healthy men.

The influence of acute plasma expansion induced by the administration of sodium containing hyperosmolar contrast medium on Frank lead electrocardiograms was investigated in 10 healthy male volunteers. The major electrocardiographic changes after injection of the contrast medium were a significant decrease in the amplitudes of Rx, Ry, and Qz and the maximal spatial QRS voltage, and a significant increase in the amplitude of Sx. The echocardiographic left ventricular end diastolic dimension tended to be larger after the injection, whereas no significant change occurred in the left ventricular systolic dimension. The electrocardiographic changes in this study were the opposite of those expected with the Brody effect. Although the precise mechanism underlying these findings is unclear, the increased intracardiac blood volume may have caused a decrease in the QRS voltage by a short circuiting effect. Alternatively if the activation in the left ventricle is assumed to be predominantly tangential the QRS voltage should have decreased with the Brody effect. The Brody effect may lead to an erroneous interpretation of electrocardiograms in certain clinical settings.

Evaluation of PSF1 as a prognostic biomarker for prostate cancer.

BACKGROUND: Partner of SLD5 1 (PSF1) is an evolutionarily conserved DNA replication factor. Previous studies have suggested that transcriptional activity of the PSF1 gene correlated with malignancy of cancer cells. The objective of the current study was to evaluate the relationship between PSF1 expression and the clinical features of prostate cancer. METHODS: We determined the expression of PSF1 in 120 needle biopsy samples of prostate cancer by immunohistochemistry. We divided patients into PSF1-positive or -negative groups and analyzed the relationships between the expression of PSF1, the Gleason score, PSA level, TNM classification and prognosis. RESULTS: Our results showed that the PSF1 expression correlated significantly with PSA values at diagnosis (P=0.0028), with tumor grade (P<0.0001), and with clinical stage (P=0.0005). Moreover, the PSF1 expression correlated significantly with overall survival (hazard ratio (HR) 5.5; 95% confidence interval (CI) 2.17-15.8; P=0.003) and progression-free survival in 99 consecutive patients with prostate cancer. Noteworthy, the prognosis of PSF1-positive cases was also worse in patients with a Gleason score of 8-10 (HR 3.7; 95% CI 1.28-13.43; P=0.0143). Limitations include that this study had a retrospective design, that patients in the study were heterogeneous and included those with early and advanced cancer, and that small tumor fragments may not be representative of the entire carcinoma. CONCLUSIONS: PSF1 is expressed in high-grade prostate cancer and may be a useful biomarker to identify patients with a poor prognosis at the time of diagnosis.

Association between chromosome 11q13 amplification and prognosis of patients with oesophageal carcinomas.

Ninety pairs of normal and tumour tissue DNAs were isolated from paraffin-embedded blocks of advanced oesophageal carcinoma cases and examined for gene amplification at chromosome 11q13 by dot-blot hybridisation using the int-2 gene as a probe. 22 of 90 carcinomas (24%) showed more than two times amplification. Although no significant correlation was observed between gene amplification and histological type or metastasis to lymph node, a tendency for deeper invasion to be associated with more frequent amplification was observed. In relation to prognosis, patients with amplification had a lower survival rate than those without amplification. This tendency was evident both in the group with well differentiated type carcinoma and in the group which had no metastasis to lymph node. Thus, gene amplification of the int-2 locus may be a useful prognostic factor.

Simvastatin enhanced sodium nitroprusside-induced apoptosis of smooth muscle cells. An involvement of geranylgeraniol.

A decrease in serum cholesterol is one of the most beneficial effects in anti-atherogenesis. Nitric oxide is also an anti-atherogenic substance, inducing vasodilation and inhibits proliferation of smooth muscle cells (SMC). Therefore, we examined sodium nitroprusside (SNP)-induced apoptosis of vascular SMC with respect to cholesterol metabolism. Cultured vascular SMC from bovine carotid arteries and rat aorta were used. Apoptosis was determined by propidium iodide assay. Treatment of the SMC with SNP(100 micromol/l-1 mmol/l ) for 6 h induced a little nuclear fragmentation. SNP (1 mmol/l ) elicited apoptosis in 4.4+/-2.2% of cells. Pretreatment of SMC with simvastatin (1 microg/ml, 2 days), a hydroxymethylglutaryl Coenzyme A (HMG CoA) reductase inhibitor, synergistically enhanced SNP-induced apoptosis (% apoptosis =15. 9+/-3.3%). Either mevalonate (100 micromol/l) or geranylgeraniol (30 micromol/l) recovered the simvastatin (1 microg/ml)-enhanced SMC apoptosis induced by SNP. Neither squalene (10 mmol/l) nor farnesol (30 micromol/l) had a recovery effect on the simvastatin-enhanced SMC apoptosis induced by SNP. Pretreatment with simvastatin (1 microg/ml) reduced total cholesterol content in SMC. Mevalonate (100 micromol/l) restored a decrease in total cholesterol content. However, incubation with LDL deficient serum did not enhance SNP-induced apoptosis of SMC, although treatment with LDL deficient serum decreased the total cholesterol content in SMC. These data suggested that decrease in HMG CoA reductase metabolites, especially geranylgeraniol might enhance the SNP-induced apoptosis of SMC, and that, apoptosis was not involved in a decrease in cholesterol of SMC.