Nominal free air in the left inguinal fossa due to perforation of the sigmoid colon in a case of blunt abdominal trauma: CT diagnosis

We present a case of perforation of the sigmoid colon due to blunt abdominal trauma. Computed tomography showed nominal free air in the inguinal fossa. The distribution of free air may be a clue to the site of an injured intestine. Early detection of intestinal injury is difficult, but repeated computed tomography after several hours may reveal increased free air.

Proximal gastrectomy and jejunal pouch interposition: evaluation of postoperative symptoms and gastrointestinal hormone secretion

Reflux esophagitis, dumping syndrome and malnutrition are included in the postgastrectomy complications. To prevent or minimize such sequelae, proximal gastrectomy with an interposed jejunal pouch has been advocated as an organ-preserving surgical strategy to improve quality of life for the patients. Proximal gastrectomy was performed in 44 patients with tumors in the upper third of the stomach; 21 had reconstruction using jejunal pouch interposition between the esophagus and the remnant stomach (JP group), while 23 had reconstruction by esophagogastrostomy (EG group). Re-construction method was selected by each patient on the basis of the informed consent. Thirty-five patients had early gastric cancer. Postoperative courses of patients were reviewed in terms of symptoms, weight maintenance, nutritional status, blood chemistry values, endoscopic findings, and radiographic appearances after a barium meal. Concentrations of gastrointestinal hormones were measured in response to a test meal. The JP procedure permitted increased dietary volume. The JP group showed fewer severe postoperative symptoms than the EG group. After operation, all patients examined in both groups showed hypergastrinemia and all patients examined in the JP group showed hypersecretinemia. In proximal gastrectomy, the JP procedure improved patient's post-operative quality of life.

Requirement of c-jun N-terminal kinase for apoptotic cell death induced by farnesyltransferase inhibitor, farnesylamine, in human pancreatic cancer cells

Farnesyltransferase inhibitors (FTIs) represent a novel class of anticancer drugs and are now in clinical trial. We have previously shown that farnesylamine, synthetic isoprenoid-linked with "amine" which acts as a potent FTI, induces apoptosis in human pancreatic cancer cells through the ras signaling cascade. Since the effect of FTI is usually "cytostatic" rather than "cytotoxic", we speculated another apoptotic machinery of farnesylamine in addition to the effect of FTI. Farnesylamine induced sustained activation of c-jun N-terminal kinase (JNK), which was not caused by other FTI, FTI-277. Blockage of JNK activity by dominant-negative mutant abrogated the DNA laddering and significantly reduced "cytotoxic" effect of farnesylamine. Strikingly similar effect on JNK activation and apoptosis was induced by structurally related long-chain fatty amine (LFA), oleylamine, but not by farnesol, an isoprenoid analogue of farnesylamine without "amine." Taken together, apoptosis induction through JNK activation by farnesylamine based on the LFA structure rather than an effect of FTI.

Substrate recognition mechanism of thermophilic dual-substrate enzyme

Aspartate aminotransferase from an extremely thermophilic bacterium, Thermus thermophilus HB8 (ttAspAT), has been believed to be specific for an acidic substrate. However, stepwise introduction of mutations in the active-site residues finally changed its substrate specificity to that of a dual-substrate enzyme. The final mutant, [S15D, T17V, K109S, S292R] ttAspAT, is active toward both acidic and hydrophobic substrates. During the course of stepwise mutation, the activities toward acidic and hydrophobic substrates changed independently. The introduction of a mobile Arg292* residue into ttAspAT was the key step in the change to a "dual-substrate" enzyme. The substrate recognition mechanism of this thermostable "dual-substrate" enzyme was confirmed by X-ray crystallography. This work together with previous studies on various enzymes suggest that this unique "dual-substrate recognition" mechanism is a feature of not only aminotransferases but also other enzymes.

A new peritoneal dissemination model established from the human pancreatic cancer cell line

We established a new cell line, HPC-3P4a, with high peritoneal disseminated potential in nude mice. HPC-3P4a was derived from a human pancreatic carcinoma cell line (HPC-3) that had low capacity for peritoneal dissemination. HPC-3P4a developed peritoneal dissemination in 10 of 11 (90.9%) cases, whereas parental HPC-3 developed peritoneal dissemination in one of six (16.7%) cases. The metastatic foci in the peritoneum showed essentially the same histologic appearance of parental involvement. The tumorigenicity, motility, and adhesive activity of HPC-3P4a to the extracellular matrix were stronger than were those of the HPC-3. In FACS analysis, HPC-3P4a significantly increased the expression of alpha6 and alpha(v)beta5 integrins, while it decreased alpha2 integrin, hCD44H, and hCD44v 10, as compared with HPC-3. The VEGF production of HPC-3P4a was significantly lower than that of HPC-3. Analysis of gene macroarrays showed a variety of cytokines, interleukin, and other immunomodulatory, and their receptors were up-regulated and down-regulated on an mRNA level in HPC-3P4a cells, compared with HPC-3 cells. Intrasplenic injection of HPC-3P4a produced no liver metastasis. We named our original highly liver metastatic cell line HPC-3H4 (previously reported). This HPC-3H4 cell was established by repeated intrasplenic injection from parental cell HPC-3; thus, it developed high liver metastasis. Moreover, HPC-3H4 developed peritoneal dissemination by intra-abdominal injection. In contrast, HPC-3P4a did not develop liver metastasis by intrasplenic injection. These findings are very interesting and might suggest that the process of hematogenous metastasis differed from that of peritoneal dissemination. Thus, this cell line may be useful for investigating the mechanism of peritoneal dissemination in human pancreatic cancer.

Liver metastatic model for human gastric cancer established by orthotopic tumor cell implantation

We have established an orthotopic implantation model that is highly metastatic to the liver. A human gastric carcinoma cell line, AZ521, with low capacity for liver metastasis was implanted as a single-cell suspension in the stomach of nude mice. The tumor cells derived from a few liver metastatic foci were subsequently implanted orthotopically, and we established a cell line, AZH5G, by repeating the in vivo stepwise selection method. This metastasizing line (AZH5G) developed liver metastasis in seven of eight (87.5%) cases, whereas parental AZ521 developed in 3 of 20 (15.0%). The in vitro growth activities of AZH5G were lower than that of AZ521, although the in vivo tumorigenicity of AZH5G was clearly higher than that of AZ521. Motility assays demonstrated higher motility of AZH5G than of AZ521. Flow cytometric analysis demonstrated that the expression of alpha 6-integrin significantly decreased in AZH5G (4.9% +/- 4.1%) compared to in AZ521 (17.7% +/- 8.1%) (p < 0.05). The adhesive activity of AZH5G cells to laminin was lower than that of AZ521 cells. In contrast, the adhesive activity of AZH5G cells to fibronectin was clearly higher than that of AZ521 cells. These findings suggested that changes in the expression of integrins on the cell surface might play an important role in metastatic ability. This well characterized line and its in vivo experimental model should be useful to investigate the mechanisms of liver metastasis and to develop a new therapeutic approach for human gastric cancer.

Temperature dependence of the enzyme-substrate recognition mechanism

We determined the crystal structure of the liganded form of alpha-aminotransferase from a hyperthermophile, Pyrococcus horikoshii. This hyperthermophilic enzyme did not show domain movement upon binding of an acidic substrate, glutamate, except for a small movement of the alpha-helix from Glu16 to Ala25. The omega-carboxyl group of the acidic substrate was recognized by Tyr70* without its side-chain movement, but not by positively charged Arg or Lys. Compared with the homologous enzymes from Thermus thermophilus HB8 and Escherichia coli, it was suggested that the more thermophilic the enzyme is, the smaller the domain movement is. This rule seems to be applicable to many other enzymes already reported.

A novel experimental mouse model of peritoneal dissemination of human gastric cancer cells: different mechanisms in peritoneal dissemination and hematogenous metastasis

We established a new cell line, AZ-P7a, with high peritoneal-metastatic potential in nude mice. AZ-P7a cells were derived from the human gastric carcinoma line AZ-521, which has low capacity for peritoneal dissemination. AZ-P7a cells developed peritoneal metastasis in 11 / 14 (78.6%) mice, whereas the parental AZ-521 cells developed metastasis in 2 / 6 (33.3%) mice. The metastatic foci in the peritoneum showed essentially the same histological appearance as those induced by parental cells. The tumorigenicity and the motile activity of AZ-P7a cells were stronger than those of the parental AZ-521 cells; in contrast, adhesion to the extracellular matrix and the production of vascular endothelial growth factor by AZ-P7a cells were decreased. In fluorescence-activated cell sorter (FACS) analysis, AZ-P7a cells expressed significantly greater levels of integrins alpha2, alpha3, alpha5, alpha6 and alphavbeta5, as compared with AZ-521 cells. However, alpha1, alpha4, alphavbeta3, hCD44H, hCD44v3, hCD44v6 and hCD44v10 were not expressed in either cell line. AZ-P7a cells developed no liver metastasis when administered by the intrasplenic injection method, though the highly liver metastatic cell line AZ-H5c showed the same rate of peritoneal dissemination as that exhibited by AZ-P7a cells after intraabdominal injection. These findings suggested that the mechanism of peritoneal dissemination differed from that of hematogenous metastasis. Moreover, the latter appears to be controlled by more complex mechanisms than the former. Thus, this cell line might be useful for investigating the mechanism of peritoneal dissemination of human gastric cancer.

Changes in hepatic venous oxygen saturation in hepatic warm ischemia/reperfusion injury in pigs

To clarify the changes that occur in hepatic venous oxygen saturation (ShVO2) during hepatic ischemia/reperfusion (I/R) injury, we examined the relationship between ShVO2, hepatic tissue blood flow (HTBF), and portal vein pressure (PVP) in a warm I/R model using pig livers. Female pigs weighing 18-23 kg were subjected to warm I/R under extracorporeal circulation between the superior mesentric vein and the left jugular vein to avoid portal congestion. The warm ischemic times were 120 min (n = 4), 180 min (n = 14), and 240 min (n = 4). ShVO2, HTBF, and PVP were measured after reperfusion. The survival rates of the pigs 3 days after reperfusion were 100% in the 120-min group, 57% in the 180-min group, and 25% in the 240-min group. In the 180-min group, the ShVO2 was lower in the pigs that died than in those that survived. There was a significant correlation between ShVO2 and both PVP and HTBF after reperfusion. Histological examination revealed findings of severe I/R injury in pigs with a low ShVO2, and mild I/R injury in pigs with a stable ShVO2. These observations suggest that the changes in ShVO2 could reflect the degree of hepatic I/R injury, especially that related to microcirculatory disturbances occurring at the sinusoid levels.

Epithelial cell proliferation and gene mutation in the mucosa of gallbladder with pancreaticobiliary malunion and cancer

The significant association between pancreaticobiliary malunion (PBM), especially undilated-type PBM, and a high risk of gallbladder cancer is known. Reflux and stasis of pancreatic juice induce various epithelial changes in the gallbladder. Recently, epithelial hyperplasia of the gallbladder was shown to be significantly and frequently associated with undilated-type PBM, and it is suggested that the majority of epithelial hyperplasia may exist at birth or be acquired in early childhood, and thereafter present throughout the lives of PBM patients. Cell kinetic studies demonstrated a significant stepwise increase in cellular proliferative activity from normal gallbladder mucosa, through epithelial hyperplasia to cancer. Epithelial hyperplasia with increased proliferative activity may predispose the mucosa to mutational events, thereby increasing cancer risk in PBM patients. K-ras mutations were frequently detected in gallbladder cancer in PBM patients and in epithelial hyperplasia as well. Epithelial hyperplasia is demonstrated to be an important premalignant lesion of gallbladder cancer. A multistep process of carcinogenesis as a consequence of multiple genetic alterations of oncogenes and tumor suppressor genes has been demonstrated in various organs; however, there is limited information on the molecular mechanism in gallbladder carcinogenesis with PBM. Recent findings support the idea that epithelial hyperplasia plays an important role in gallbladder carcinogenesis with PBM and also support the concept that neoplastic development in gallbladder with PBM also evolves through a multistep process associated with hyperproliferation and genetic alterations.

Establishment and characterization of a human gastric carcinoma cell line that is highly metastatic to lymph nodes

The actual mechanisms by which carcinoma cells metastasize to lymph nodes are still unclear, and there is a need to establish in vivo experimental models suitable for the investigation of lymph node metastasis. For the purpose, we established a highly lymph node-metastasizing line, designated AZL5G, derived from a human gastric cancer cell line, AZ521, which had low capacity for lymph node metastasis. AZL5G cells transplanted orthotopically in the nude mouse stomach metastasize predominantly to the regional lymph nodes, showing little potential for hematogenous metastasis. AZL5G tumors developing in the stomach and regional lymph nodes showed poorly differentiated adenocarcinoma with medullary growth, and their histologic appearance strongly resembled that of parental AZ521. The growth activities in vitro of low-metastatic AZ521 and high-metastatic AZL5G were almost the same, but the tumorigenicity in vivo of AZL5G was significantly higher than that of AZ521. AZL5G cells also showed clearly higher abilities of cell locomotion and adhesion to type IV collagen and fibronectin in vitro as compared with AZ521 cells. Flow cytometric analysis demonstrated that the expression of integrin beta1 subfamily except for alpha6 integrin was generally increased in AZL5G cells than in AZ521 cells. Especially, the expression of alpha1 and alpha2 integrins in AZL5G cells was clearly higher than in AZ521, while alpha(v)beta3 integrin, E-cadherin, ICAM-1 and CD44H were not expressed by either cell line. The cell adhesion blocking assay showed that DGEA-containing peptide, which is composed of alpha2 integrin recognition sequence, significantly reduced the adhesiveness of AZL5G cells to type IV collagen as well as to type I collagen and laminin. Furthermore, the administration of anti-alpha2 integrin mAb or DGEA peptide in AZL5G-transplanted nude mice produced a significant reduction in the number of lymph node metastases. These data suggest that the up-regulation of alpha2 integrin expression by gastric cancer cells may play a critical role in the process of lymph node metastasis through the increased adhesiveness to type IV collagen. In conclusion, we established a gastric cancer cell line, AZL5G, with a highly metastatic potential to lymph nodes. This well-characterized line and its in vivo experimental model should be useful for investigation of the mechanisms of lymph node metastasis and for establishment of a new therapeutic approach for human gastric cancer.

The molecular structure of hyperthermostable aromatic aminotransferase with novel substrate specificity from Pyrococcus horikoshii

Aromatic amino acid aminotransferase (ArATPh), which has a melting temperature of 120 degrees C, is one of the most thermostable aminotransferases yet to be discovered. The crystal structure of this aminotransferase from the hyperthermophilic archaeon Pyrococcus horikoshii was determined to a resolution of 2.1 A. ArATPh has a homodimer structure in which each subunit is composed of two domains, in a manner similar to other well characterized aminotransferases. By the least square fit after superposing on a mesophilic ArAT, the ArATPh molecule exhibits a large deviation of the main chain coordinates, three shortened alpha-helices, an elongated loop connecting two domains, and a long loop transformed from an alpha-helix, which are all factors that are likely to contribute to its hyperthermostability. The pyridine ring of the cofactor pyridoxal 5'-phosphate covalently binding to Lys(233) is stacked parallel to F121 on one side and interacts with the geminal dimethyl-CH/pi groups of Val(201) on the other side. This tight stacking against the pyridine ring probably contributes to the hyperthermostability of ArATPh. Compared with other ArATs, ArATPh has a novel substrate specificity, the order of preference being Tyr > Phe > Glu > Trp > His>> Met > Leu > Asp > Asn. Its relatively weak activity against Asp is due to lack of an arginine residue corresponding to Arg(292)* (where the asterisk indicates that this is a residues supplied by the other subunit of the dimer) in pig cytosolic aspartate aminotransferase. The enzyme recognizes the aromatic substrate by hydrophobic interaction with aromatic rings (Phe(121) and Tyr(59)*) and probably recognizes acidic substrates by a hydrophilic interaction involving a hydrogen bond network with Thr(264)*.

Epithelial hyperplasia of the gallbladder in children with anomalous pancreaticobiliary ductal union

BACKGROUND/AIMS

Few data are available on the fate and incidence of epithelial hyperplasia throughout the life of anomalous pancreaticobiliary ductal union (APBD) patients. The pathological study in pediatric APBD patients is less recognized.

METHODOLOGY

Ten resected gallbladders obtained from children with APBD and control patients without APBD were examined histologically, and immunohistochemically for the detection of Ki-67 (as a proliferative marker) and p53. K-ras mutations in codon 12 were also examined. Epithelial hyperplasia was classified into high-grade and low-grade hyperplasia.

RESULTS

Six (60%) of 10 patients with APBD had epithelial hyperplasia of the gallbladder, whereas no patients without APBD exhibited this lesion. Diffuse epithelial hyperplasia was observed in 1 (50%) of 2 undilated-type APBD and 5 (63%) of 8 dilated-type. Two (33%) of 6 patients with epithelial hyperplasia exhibited high-grade hyperplasia. Ki-67 labeling index (LI) was significantly higher in hyperplastic mucosa than in control gallbladder mucosa. K-ras mutations and p53 overexpression were not detected in hyperplastic and normal mucosa.

CONCLUSIONS

Epithelial hyperplasia of the gallbladder accompanied by increased proliferative activity exists at birth or is acquired in childhood with APBD patients and may be an important factor predisposing to the development of gallbladder carcinoma.

[Mechanisms of cell death in hypoxic stress]

The present article attempts to summarize and introduce the mechanisms of hypoxia-induced cell death. Necrosis is associated with rapid metabolic collapse that leads to cell swelling, early loss of plasma membrane integrity, and ultimate cell rupture, in which cytosolic contents leak from necrotic cells causing injury to and inflammation of the surrounding tissue. In contrast, apoptosis is an energy-requiring, gene-directed process, which results in cell suicide without any injury to surrounding tissues. Although apoptosis and necrosis are conceptually distinct pathways of cell death, recent advances have revealed that hypoxic cell damage can induce both necrosis and apoptosis simultaneously. Loss of the mitochondrial membrane potential (MMP) precedes the morphological changes in cell death, and overexpression of Bcl-2 or Bcl-XL blocks apoptosis as well as hypoxia-induced necrosis by maintaining MMP. These findings indicate that apoptosis and some types of necrosis share common features in the death signaling pathway. The factors that determine whether cells undergo apoptosis or necrosis are still unclear, but intracellular ATP levels and/or their rate of decline are considered to be one possible determinant of the manifestation of cell death.

alpha-Fetoprotein-producing adenocarcinoma of the pancreas presenting focal hepatoid differentiation

We report a rare case of pancreatic carcinoma producing alpha-fetoprotein (AFP), showing focal hepatoid differentiation in metastatic lymph nodes. A 65-yr-old female was admitted because of abdominal pain. The serum AFP was measured at 16,170 ng/mL. Radiological examinations revealed a mass measuring 6 cm in diameter in the body and tail of the pancreas. A right supraclavicular lymphadenopathy was found and biopsied. Light microscopy showed a tumor consisting of a portion of a hepatoid area and well-differentiated adenocarcinoma, which was suggestive of a hepatoid adenocarcinoma. Immunohistochemical analysis showed that the tumor cells expressed AFP, alpha 1-antitrypsin (AT) and albumin. Although the pathological diagnosis of the primary pancreatic tumor was not obtained, this appears to be the first case of hepatoid adenocarcinoma of the pancreas.

Urokinase-type plasminogen activator and plasminogen activator inhibitor-1 as a prognostic factor in human colorectal carcinomas

BACKGROUND/AIMS

The urokinase pathway of plasminogen activation is known to be involved in proteolytic degradation of the extracellular matrix during carcinoma invasion.

METHODOLOGY

We immunohistochemically examined 97 colorectal carcinomas for the expression of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) to investigate whether uPA and PAI-1 expressions could serve as prognostic parameters; the gene expression of uPA and PAI-1 in human colon cancer tissues was also analyzed using reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The relative expression levels of uPA and PAI-1 mRNAs were well correlated with immunoreactivities of uPA and PAI-1, respectively (p < 0.05). In immunohistochemical staining, diffuse specific staining was observed in the cytoplasm of carcinoma cells. uPA expression was detected in 57 carcinoma specimens (58.8%) and PAI-1 expression was detected in 36 specimens (37.1%). With regard to 5-year overall survival rate, patients whose tumors had positive uPA and negative PAI-1 immunoreactivities had a significantly poorer prognosis (p < 0.05). In multivariate analysis, the combined variable of uPA and PAI-1 was shown to be an independent prognostic indicator.

CONCLUSIONS

Our results suggest that immunohistochemical combined analysis of uPA and PAI-1 may be a useful prognostic factor in colorectal carcinoma patients.

Establishment and characterization of human pancreatic carcinoma lines with a high metastatic potential in the liver of nude mice

To investigate of human pancreatic cancer metastasis to the liver, a pancreatic carcinoma line, HPC-3, was injected into the spleens of nude mice. The cells from a few liver metastatic foci of the mice injected with HPC-3 were expanded in vitro and subsequently injected into the spleens of nude mice. By repeating these procedures, we were able to obtain a cell line, designated HPC-3H4. The mice were observed to have liver metastasis in 6 of 6 (100%) cases injected with HPC-3H4, whereas the rate was 0% at 3 weeks after the intrasplenic injection of HPC-3. The tumorigenicity of HPC-3H4 was more rapid than that of HPC-3. The motile activity of HPC-3H4 was also stronger than that of HPC-3, and the adhesion to the extracellular matrix of HPC-3H4 was stronger than that of HPC-3. We also analyzed the cell surface expression of the metastasis-related adhesion molecules. As a result, no substantial changes were observed in the expression level of adhesion molecules. These results suggest that HPC-3H4 is useful for studies aimed at the prevention of liver metastasis.

Histiocytic necrotizing lymphadenitis (Kikuchi's disease): the necrotic appearance of the lymph node cells is caused by apoptosis

We report a case of histiocytic necrotizing lymphadenitis in a 28-year-old woman. The biopsy specimen of the enlarged lymph node showed lymphocytes, histiocytes, and a large amount of nuclear debris as well as marked eosinophilic deposits. We found DNA fragments by means of the modified TUNEL method, especially in the transitional area between intact cells and the foci of eosinophilic deposits and the cells positive for anti-Fas antibody in the biopsied lymph node. Therefore, the necrotic appearance of the lymph node was thought to be caused by apoptosis induced by the Fas-Fas ligand system. We hypothesize that the apoptosis was strongly related to the pathogenesis of this disease.

Development of an ulcer in the side-to-side anastomosis of a jejunal pouch after proximal gastrectomy reconstructed by jejunal interposition: report of a case

We present herein the first reported case of a deep ulceration developing in the pouch of a jejunal side-to-side anastomosis following the interposition of a jejunal U-shaped pouch (jejunal pouch), performed as reconstruction. A 47-year-old woman underwent a proximal gastrectomy and interposition of a jejunal pouch for early gastric cancer, 4 months after which she began to develop a fever. Esophagogastroscopy revealed a deep ulceration in the side-to-side anastomosis of the jejunal pouch. Her serum gastrin level was much higher than the normal range, and 24-h monitoring of the intraremnant stomach pH revealed that it was below 7.0 at night. A peptic ulcer was thought to be one of the causes of the pouchitis. Due to the drug-resistant ulceration and fever, a reoperation was performed, in which the jejunal pouch and remnant stomach were removed and Roux-en-Y reconstruction was done. There were no postoperative complications, and the fever resolved after surgery. Reconstruction of the jejunal pouch after proximal gastrectomy is recommended from the standpoint of quality of life (QOL); however, further studies on the size of the remnant stomach and the length of the interposed jejunal pouch are necessary.

The novel substrate recognition mechanism utilized by aspartate aminotransferase of the extreme thermophile Thermus thermophilus HB8

Aspartate aminotransferase (AspAT) is a unique enzyme that can react with two types of substrate with quite different properties, acidic substrates, such as aspartate and glutamate, and neutral substrates, although the catalytic group Lys-258 acts on both types of substrate. The dynamic properties of the substrate-binding site are indispensable to the interaction with hydrophobic substrates (Kawaguchi, S., Nobe, Y., Yasuoka, J., Wakamiya, T., Kusumoto, S., and Kuramitsu, S. (1997) J. Biochem. (Tokyo) 122, 55-63). AspATs from various organisms are classified into two subgroups, Ia and Ib. The former includes AspATs from Escherichia coli and higher eukaryotes, whereas the latter includes those from Thermus thermophilus and many prokaryotes. The AspATs belonging to subgroup Ia each have an Arg-292 residue, which interacts with the distal carboxyl groups of dicarboxylic (acidic) substrates, but the functionally similar residue of subgroup Ib AspATs has not been identified. In view of the x-ray crystallographic structure of T. thermophilus AspAT, we expected Lys-109 to be this residue in the subgroup Ib AspATs and constructed K109V and K109S mutants. Replacing Lys-109 with Val or Ser resulted in loss of activity toward acidic substrates but increased that toward the neutral substrate, alanine, considerably. These results indicate that Lys-109 is a major determinant of the acidic substrate specificity of subgroup Ib AspATs. Kinetic analysis of the interactions with neutral substrates indicated that T. thermophilus AspAT is subject to less steric hindrance and its substrate-binding pocket has a more flexible conformation than E. coli AspAT. A flexible active site in the rigid T. thermophilus AspAT molecule may explain its high activity even at room temperature.

Separate functions of alpha2beta1 and alpha3beta1 integrins in the metastatic process of human gastric carcinoma

The expression of alpha2beta1 and alpha3beta1 integrins was studied immunohistochemically in 110 resected human gastric carcinomas. Formalin-fixed and paraffin-embedded samples were serially sectioned and stained with monoclonal antibodies specifically against the alpha2 and alpha3 subunits of beta1 integrins. Approximately 27% of the tumors expressed alpha2beta1 integrin, and 20% expressed alpha3beta1 integrin. The expression of alpha2beta1 integrin was associated with lymph node and liver metastases (P < 0.05 and P < 0.05, respectively), and the expression of alpha3beta1 integrin was associated with liver and peritoneal metastases (P < 0.005 and P < 0.0005, respectively). A multivariate analysis by the logistic regression model revealed that the expression of alpha2beta1 and/or alpha3beta1 integrins was an independent factor related to liver metastasis, and that the expression of alpha3beta1 integrin was as strong an influence on the formation of peritoneal metastases as the depth of invasion. The expression of alpha3beta1 integrin also correlated with increased invasiveness of the tumor; however, there was no correlation between alpha2beta1 integrin expression and the invasiveness. These results suggest that alpha2beta1 and alpha3beta1 integrins have separate influences on the metastatic properties of cancer cells.

Solitary true cyst of the pancreas in two adults: analysis of cyst fluid and review of the literature

Solitary true cyst of the pancreas in adults is extremely rare. We report two adult cases of solitary true cyst of the pancreas. In a 53-yr-old woman there was discovered, incidentally, a unilocular cyst of 7.0 x 6.5 cm in size in the tail of the pancreas that was noted on abdominal US and CT scan. A 16-yr-old boy presented with abdominal pain, and an abdominal US and CT scan revealed a 6.5 cm cystic mass located in the tail of the pancreas. Both patients underwent distal pancreatectomy. Histologically, the cyst was lined with flattened cuboidal and squamous epithelium without morphological alterations. Analysis of the cyst fluid revealed high CA 19-9 (>100,000 U/L) and Span-1 levels (>60,000 U/L) in both cases. Immunohistochemically, the lining epithelial cells of true cyst were positive for CA 19-9 staining. The clinicopathological features of solitary true cyst of the pancreas in adults are briefly reviewed.

Multifocal serous cystadenoma of the pancreas. A case report and review of the literature

Serous cystadenoma of the pancreas is usually unifocal; multifocal tumors are rare. We report a case of multifocal serous cystadenoma of the pancreas in a 48-yr-old female complaining of general malaise. Serum tumor markers, such as CA 19-9, DUPAN-2, and Span-1, were elevated. Abdominal ultrasound (US) and computed tomography (CT) scans revealed two distinct cystic masses in the head and body of the pancreas, respectively. The patient underwent total pancreatectomy. The resected pancreas contained two discrete cystic masses in the head and body; no solid components were observed. Microscopically, the inner surfaces of the cysts were evenly lined by a single layer of low cuboidal or significantly attenuated epithelial cells containing clear cytoplasm and abundant glycogen without other morphological alterations. The histogenesis of serous cystadenoma is not clear; multicentric tumors may be helpful in understanding histogenesis.

[Mechanism of the development of organ failure]

Multiple organ failure (MOF) is a critical condition developing in patients with overwhelming bodily injury resulting from major surgical insult, severe trauma, extensive burns, acute pancreatitis, and sepsis. It has recently become evident that the host response to such injury is the main pathogenetic factor contributing to the development of MOF. The proinflammatory cytokines tumor necrosis factor (TNF) and interleukin (IL)-1 are known to play a pivotal role in the pathogenetic mechanisms of MOF. In response to bodily injury, macrophages produce and release TNF and IL-1, which subsequently induce the production of other cytokines (IL-6, IL-8, etc.) and other endogenous chemical mediators. The resultant systemic inflammation may develop into MOF mainly through neutrophil-endothelial cell interaction when the primary injury is overwhelming or a second inflammatory insult such as sepsis triggers an exacerbated inflammation. It has recently been confirmed that the transcription factor NF-kappaB is involved in the up-regulation of a variety of proinflammatory genes and that cell-mediated immunity is down-regulated in the event of major bodily injury through a shift in the balance between T helper 1 (Th1) and Th2 cytokine response patterns. The molecular immunological mechanisms by which these factors participate in the development of MOF should be characterized.

Proliferative potential and K-ras mutation in epithelial hyperplasia of the gallbladder in patients with anomalous pancreaticobiliary ductal union

BACKGROUND

Recent studies have shown that anomalous pancreaticobiliary ductal union (APBD) is an important risk factor for the development of gallbladder carcinoma. Epithelial hyperplasia of the gallbladder is one of the characteristic changes, but it is not clear whether epithelial hyperplasia is a premalignant lesion that could lead to cancer in APBD patients.

METHODS

Twenty-four APBD patients were classified into two types: patients with bile duct dilation (dilated type) (n 13) and patients without dilation (undilated type) (n = 11). Resected gallbladders obtained from APBD patients and control patients without APBD were examined histologically and with immunohistochemical techniques for the detection of p53 and Ki-67 (as a cell proliferation marker). K-ras mutations were examined using polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequence analysis. The patients were also classified, according to extent of epithelial hyperplasia, as having high grade or low grade hyperplasia.

RESULTS

Fifteen (63%) of 24 APBD patients had epithelial hyperplasia of the gallbladder, whereas no patients without APBD exhibited this lesion. The incidence of epithelial hyperplasia was significantly higher in the gallbladders of undilated-type APBD patients (91%) than in those of dilated-type patients (38%) (P < 0.01). Three of 24 APBD patients (13%) had gallbladder carcinoma, and 2 of the 3 gallbladder carcinomas (67%) were accompanied by diffuse epithelial hyperplasia of the gallbladder. Among 21 nonneoplastic gallbladders, diffuse epithelial hyperplasia was observed in all (100%) of the undilated-type APBD and in 4 (33%) of 12 dilated-type APBD (P < 0.001). High grade hyperplasia was observed in 7 of 11 patients (64%) with undilated-type APBD and 2 of 13 patients (15%) with dilated-type APBD (P < 0.05). The incidence of high grade hyperplasia increased with age among patients older than 35 years. Ki-67 labeling index (LI) was significantly higher in hyperplastic mucosa than in control gallbladder mucosa. High grade hyperplasia had a significantly higher Ki-67 LI than low grade hyperplasia (P < 0.001). Two (22%) of 9 high grade hyperplasia cases had K-ras mutations, whereas none of 6 low grade hyperplasia cases had. The types of K-ras mutations in codon 12 were GTT (Val) and GAT (Asp) in each case of hyperplasia; these were identical to those of concomitant carcinomas. Neither hyperplastic nor normal mucosa exhibited p53 overexpression.

CONCLUSIONS

The results of this study suggest that hyperplasia of the gallbladder mucosa in APBD patients is an early change that, because of the increased proliferative activity and presence of K-ras mutations, could be considered a premalignant lesion of the gallbladder. An increased cell population of epithelial hyperplasia may predispose the mucosa to mutational events, resulting in an increased risk for the development of gallbladder carcinoma in APBD patients.

Carcinoma arising from ectopic pancreas in the stomach: endosonographic detection of malignant change

We present a case of a submucosal tumor in the stomach that was suspicious for malignancy on preoperative endosonography. The resected tumor was histologically diagnosed as a ductal adenocarcinoma that originated in ectopic pancreatic tissue in the gastric wall. Although malignant transformation in ectopic pancreas is extremely rare, it remains an important consideration in the differential diagnosis of gastric submucosal masses.

Efficacy of endoscopic diagnosis and treatment for postoperative biliary leak

BACKGROUND/AIMS

The purpose of this study was to evaluate the efficacy of endoscopic approaches for the diagnosis and treatment of postoperative biliary leak.

METHODOLOGY

Endoscopic retrograde cholangiopancreatography (ERCP) was performed in eight patients with postoperative biliary leak. Of 8 cases, 6 had biliary leak alone (4 cases with a cystic duct leak and 2 cases with a bile duct leak) and 2 cases with a bile duct leak were associated with a bile duct stricture. Endoscopic sphincterotomy (ES) and endoscopic biliary stenting (EBS) were employed in 5 patients and nasobiliary tube drainage (NBD) without ES was performed in 3 patients.

RESULTS

In all the patients, ERCP was successfully performed and could demonstrate exact nature and site of postoperative bile duct injuries. In 2 patients with a concomitant bile duct stricture, repetitive endoprosthesis placements were required. The remaining six patients with biliary leak alone were successfully treated by temporary stenting, i.e., ES and EBS (n = 3), and NBD (n = 3).

CONCLUSIONS

The patients with postoperative biliary leaks can be successfully diagnosed by ERCP and treated by temporary endoscopic methods. Among various endoscopic treatments, NBD alone appears to be preferable in treating patients with small bile leaks. However, cases with a concomitant bile duct stricture were intractable and required longer period of stenting.

Segmental groove pancreatitis accompanied by protein plugs in Santorini's duct

"Groove pancreatitis", a form of segmental pancreatitis affecting the head of the pancreas, is localized within the "groove" between pancreas head, duodenum, and common bile duct. Differentiation between groove pancreatitis and pancreatic head carcinoma is often difficult. We report a case of groove pancreatitis in which a hypoechoic mass between the duodenal wall and pancreas was clearly imaged, and narrowing of the second portion of the duodenum and bile duct stenosis were also found. The diagnosis was confirmed by surgery (pylorus-preserving pancreato duodenectomy). The patient was relieved from abdominal pain post operation. Up to the present, the patient has been good condition. We review the clinicopathologic and radiologic features of groove pancreatitis in the Japanese literature and discuss the possible role of Santorini's duct in its pathogenesis. We consider that impacted protein plugs in Santorini's duct are a pathogenic factor in the development of groove pancreatitis. Therefore, the findings of Santorini's duct on endoscopic retrograde pancreatography are very important in the diagnosis of groove pancreatitis. Groove pancreatitis presents various clinical features, such as biliary stenosis, duodenal stenosis, and pancreatic mass, and often masquerades as pancreatic head carcinoma. This condition should be kept in mind in the differential diagnosis of pancreatic head carcinoma.

Lack of survival benefit of extended lymph node dissection for ductal adenocarcinoma of the head of the pancreas: retrospective multi-institutional analysis in Japan

It has not been established that extended lymph node resection is necessary for ductal adenocarcinoma of the head of the pancreas. According to the general rules for the study of pancreatic cancer, a multiinstitutional, retrospective clinical study was undertaken to investigate the efficiency of extended lymph node dissection for this malignancy. Altogether 501 patients underwent resection of the pancreas between 1991 and 1994 at 77 medical facilities; the surgical procedures, staging, lymph node dissection, curability, and survival rate were analyzed retrospectively. Eighteen of the patients died within 30 postoperative days, leaving 483 patients to be studied. The resection was curative microscopically in 94 patients, resulting in a 3-year survival of 29%. Macroscopically curative resection resulted in a 3-year survival of 14%; noncurative resection produced a 3-year survival of 6%. Although extended lymph node dissection was performed on 38 patients in stage I, 42 patients in stage II, 206 patients in stage III, and 1 patient in stage IV, there was no improvement in survival when the results were compared to those seen after standard or palliative lymph node dissection. The extent of lymph node dissection has not affected the prognosis for ductal adenocarcinoma of the head of the pancreas at any stage of the course of the disease. Excessive lymph node dissection in advanced cases does not necessarily lead to a favorable prognosis. The patients who undergo a radical operation with an adequate lymph node dissection have longer survivals.

Selective cytotoxicity of farnesylamine to pancreatic carcinoma cells and Ki-ras-transformed fibroblasts

Farnesyl protein transferase (FPTase) catalyses the post-translational modification of proteins by a farnesyl pyrophosphate. One of the substrates of this enzyme is p21ras, the product of the ras oncogene. We examined whether farnesylamine, one of the FPTase inhibitors (FTI), is selectively cytotoxic in pancreatic carcinoma cells and Ki-ras-transformed fibroblasts. Furthermore, we investigated whether the cytotoxicity of farnesylamine is caused by the induction of apoptosis in these cells. Using the FPTase assay, we found that farnesylamine inhibited FPTase in vitro. Immunoprecipitation showed that farnesylamine inhibited farnesylation of p21ras in vivo. In addition, 24 and 5 microM farnesylamine were required to achieve 50% cytotoxicity in pancreatic carcinoma cells containing activated Ki-ras and Ki-ras-transformed NIH/3T3 cells, respectively. The parental NIH/3T3 cells were resistant to the cytotoxic effect of farnesylamine at concentrations less than 100 microM. After incubation with farnesylamine, DNA fragmentation was observed in both pancreatic carcinoma cells and Ki-ras-transformed fibroblasts at cytotoxic doses of this compound but not in NIH/3T3 cells. These results indicate that the mechanism of cell death induced by farnesylamine is apoptosis, and this apoptosis occurred specifically in pancreatic carcinoma cells containing mutated Ki-ras and the Ki-ras-transformed cells. Because raf is downstream of ras (p21ras) in the ras-raf-mitogen-activated protein kinase signaling pathway, we used c-raf-1-transformed fibroblasts, which proved to be resistant to apoptosis induced by farnesylamine. This supports the theory that inhibition of ras signaling may be related to the induction of apoptosis. These data further suggest that farnesylamine could be useful as a chemotherapeutic agent in cancers that very frequently contain a Ki-ras oncogene mutation, e.g., pancreatic cancer.

Circulating levels of 7 S domain of type IV collagen and atrial natriuretic peptide in normotensive type 2 diabetic patients with or without retinopathy

Thickening of the basement membrane and other structural alterations of the vascular walls occur frequently in patients with diabetes. The vascular response to atrial natriuretic peptide (ANP) is also altered in these patients. Abnormal vascular response in diabetes may be due to alteration of vascular physicochemical properties induced by accumulation of components of vascular basement membrane. The aim of this study was to evaluate the relationship between circulating levels of the 7 S domain of type IV collagen (7 S-collagen), and ANP in normotensive type 2 diabetic patients with or without retinopathy. Forty-one normotensive type 2 diabetic patients (n = 19 with and n = 22 without retinopathy) and 18 age-matched control subjects participated in the study. Serum 7 S-collagen and plasma ANP levels were measured by radioimmunoassays. Serum 7 S-collagen (4.4 +/- 0.1 vs 3.5 +/- 0.1 ng/ml; p < 0.01) levels and plasma ANP (20.8 +/- 1.0 vs 15.5 +/- 1.0 pg/ml; p < 0.01) were significantly higher in diabetic patients than in normal subjects. Serum 7 S-collagen increased significantly in diabetic patients without retinopathy compared with normal subjects (4.1 +/- 0.1 vs 3.5 +/- 0.1 ng/ml; p < 0.01). Diabetic patients with retinopathy showed significantly higher circulating concentrations of 7 S-collagen (4.6 +/- 0.1 vs 4.1 +/- 0.1 ng/ml; p < 0.01) and ANP (22.9 +/- 1.4 vs 18.9 +/- 1.3 pg/ml; p < 0.05) than those without retinopathy. There was a significant and positive correlation (r = 0.51, p < 0.01) between the circulating levels of 7 S-collagen and ANP in all patients. The results of this investigation showed that increased circulating levels of ANP correlate with the abnormal metabolism of the vascular basement membrane observed in diabetic patients with microangiopathy.

Association between anomalous pancreaticobiliary ductal union and adenomyomatosis of the gall-bladder

A frequent association of biliary tract carcinoma and anomalous pancreaticobiliary ductal union (APBD) is well recognized, especially gall-bladder carcinoma in undilated type APBD. However, little is known about the presence and incidence of adenomyomatosis (AMT) of the gall-bladder, a presumed premalignant lesion, in patients with APBD. This retrospective study was conducted to elucidate the clinical features and incidence of AMT in APBD patients with relation to undilated type and dilated type APBD. We reviewed the clinicopathological records of 30 patients with APBD (28 women and two men) encountered during the past 10 years. Among them, 22 patients underwent cholecystectomy and the resected specimens were subjected to histopathological examinations. Eleven cases of APBD patients were undilated type and 11 cases were dilated type. Adenomyomatosis was found in six (55%) of 11 undilated type and one (9%) of 11 dilated type, and fundal type was predominantly observed in six (86%) of seven AMT. An overall incidence of AMT in APBD patients was 32%. An undilated type of APBD is frequently associated with AMT and we believe, therefore, that clinicians should be aware of a possible coexistence of APBD and AMT.

Thickened inner hypoechoic layer of the gallbladder wall in the diagnosis of anomalous pancreaticobiliary ductal union with endosonography

BACKGROUND

An anomalous pancreaticobiliary ductal union (APBD) is a high-risk factor for biliary tract carcinoma, which often is not diagnosed before overt malignancy. The early detection of APBD is therefore clinically important. We evaluated the gallbladder wall in APBD patients with endoscopic ultrasonography.

METHODS

Clinicopathologic features and ultrasonographic findings of the gallbladder in 33 consecutive patients with APBD between 1986 and 1995 were studied in relation to two subtypes of APBD, that is, undilated (n = 17) and dilated (n = 16). The gallbladder wall was evaluated with conventional ultrasonography and/or endoscopic ultrasonography. Histologic examinations of 25 resected gallbladders were made.

RESULTS

Fourteen of the seventeen patients with undilated type APBD (82%) had diffuse thickened gallbladder wall of 4 mm or more, whereas 5 of the 16 with dilated type (31%) had this finding (p < 0.01). The thickened gallbladder wall consisted sonographically of two layers: diffuse thickened inner hypoechoic layer and outer hyperechoic layer. Mucosal hyperplasia was histologically found in 8 of 9 cases (89%) with thickened inner hypoechoic layer on endoscopic ultrasonography. Mucosal hyperplasia was observed in 10 of 11 undilated type APBD cases (91%) in which cholecystectomy was performed. In addition, the presence of anomalous union was shown by endoscopic ultrasonography in 9 of 11 patients with undilated type APBD (82%) and all 7 of those with dilated type. The characteristic ultrasonographic pattern of diffuse thickened inner hypoechoic layer was observed exclusively in patients with mucosal hyperplasia of the gallbladder associated with APBD among 2085 endoscopic ultrasonography examinations performed during the study period.

CONCLUSIONS

Diffuse thickened inner hypoechoic layer of the gallbladder wall was frequently observed in APBD patients, especially those with the undilated type, on ultrasonography and/or endoscopic ultrasonography. This finding corresponded histologically to mucosal hyperplasia of the gallbladder mucosa. Thickened inner hypoechoic layer is a useful ultrasonographic sign that indicates mucosal hyperplasia of the gallbladder and, particularly, the possible coexistence of undilated type APBD before the appearance of overt malignancy.

Close correlation between increased sialyl-Lewisx expression and metastasis in human gastric carcinoma

Expression of sialyl-Lewisx (sLex) antigen was studied immunohistochemically in 110 resected human gastric carcinomas using an anti-sLex monoclonal antibody. Lymph node, liver, and peritoneal metastases were clearly more prevalent in tumors expressing high levels of sLex than in those with no or low-level sLex expression. No correlation was found between sLex expression and histologic grade or histologic type of the Lauren classification. Among the tumors with lymph node metastasis, 44% expressed high levels of sLex in both the primary tumor and involved lymph nodes, and 14% of the metastatic lesions demonstrated increased sLex expression. The 5-year survival rate of the patients undergoing complete (R0) gastric resections was 60% in the sLex high-expression group, which was significantly lower than that of the sLex low-expression group (81%) and of the no-expression group (87%) (p < 0.05). These results suggest that high-level sLex expression is related to both an increased risk of metastasis and poor prognosis in gastric cancer patients.

Serum 7S domain of type IV collagen levels in essential hypertension and hypertensive type 2 diabetic patients

Metabolic alteration of Type IV collagen occurs in micro- or macrovascular basement membrane of diabetic patients. Hypertension, a risk factor for clinical progression of diabetic vascular disease, may influence this metabolic alteration. The object of this study was to evaluate the serum 7S domain of type IV collagen (7S-collagen) levels in patients with essential hypertension and in Type 2 diabetic patients with or without hypertension and to investigate the relationship between the type IV collagen metabolism and the arterial blood pressure. Serum 7S-collagen levels in 18 patients with essential hypertension were significantly higher than in 24 normal subjects (4.2 +/- 0.5 vs 3.6 +/- 0.4 ng ml(-1) p < 0.01). Serum 7S-collagen levels in 28 normotensive diabetic patients (4.2 +/- 0.5 ng ml(-1)) were significantly higher than in normal subjects (p < 0.01). The serum 7S-collagen levels were significantly higher in 22 diabetic patients with hypertension (4.8 +/- 0.6 ng ml(-1)) than in the other groups. There was a significant correlation between the serum 7S-collagen levels and the systolic blood pressure in cases with essential hypertension (r = 0.59, p < 0.001) and in all diabetic patients (r = 0.52, p < 0.001), suggesting that elevation of the systolic blood pressure may influence the type IV collagen metabolism of vascular basement membrane. We conclude that the metabolic alteration of basement membrane occurring in patients with diabetes mellitus may worsen in the presence of high systolic blood pressure.

Effect of the calcium channel blocker nilvadipine on urinary albumin excretion in hypertensive microalbuminuric patients with non-insulin-dependent diabetes mellitus

A 24-week study was conducted to evaluate the effects of the dihydropyridine calcium channel blocker nilvadipine on urinary albumin excretion in eight microalbuminuric hypertensive patients with non-insulin-dependent (type II) diabetes mellitus. Blood pressure and urinary albumin excretion measurements before the administration of nilvadipine (8 mg) were compared with those after 4, 8, 12 and 24 weeks of treatment. No significant changes were observed in the mean values of haemoglobin A1C. Systolic blood pressure was significantly reduced from 174 +/- 23 mmHg before treatment to 144 +/- 13 mmHg after 24 weeks of treatment (P < 0.02). Diastolic blood pressure was significantly reduced from 93 +/- 11 mmHg at baseline to 79 +/- 8 mmHg after 24 weeks of treatment (P < 0.05). Urinary albumin excretion was significantly reduced from 65.4 +/- 37.4 mg/g creatinine at baseline to 51.6 +/- 41.1 mg/g creatinine (P < 0.05) after 4 weeks, and to 39.1 +/- 26.9 mg/g creatinine (P < 0.02) after 24 weeks of treatment. These data suggest that in hypertensive microalbuminuric patients with non-insulin-dependent diabetes mellitus, treatment of hypertension with the calcium blocker nilvadipine may slow the progression of diabetic nephropathy.

Splenic hamartoma associated with thrombocytopenia

A case of splenic hamartoma associated with thrombocytopenia is reported. A 70-year-old man was referred to our hospital because of carcinoma of the body of the pancreas. Hematological examination disclosed thrombocytopenia and elevated serum CA19-9 and Span-1 levels. In addition to typical findings of pancreatic carcinoma, a solid mass was observed in the spleen by imaging procedures. On ultrasonography, the splenic mass was well demarcated and slightly hypoechoic. Computed tomography demonstrated a homogeneous low-density mass 5 cm in diameter. On T1- and T2-weighted magnetic resonance images, the splenic mass was demonstrated as low intensity and high intensity, respectively. On selective angiography, the tumor was hypervascular. Distal pancreatectomy plus splenectomy was performed. Microscopically, the splenic tumor consisted of red pulp tissue and was diagnosed as splenic hamartoma.

Abnormal metabolism of type-IV collagen in normotensive non-insulin-dependent diabetes mellitus patients

The objective of this study was to investigate the serum level of the 7S domains of type-IV collagen [IVc(7S)] and its relations with microangiopathy in non-insulin-dependent diabetes mellitus (NIDDM). This study comprised 73 patients with NIDDM that were consulted in our outpatient clinic. Among the 73 NIDDM patients, 43 with normal arterial pressure were selected to assess the relationship between serum levels of 7S collagen and microangiopathy. There was a significant relationship between the serum IVc(7S) levels and the presence of retinopathy and nephropathy. These findings suggest that an increased IVc (7S) concentration may reflect the abnormal collagen metabolism of the vascular basement membrane in NIDDM patients. Column chromatography of the NIDDM patients' sera revealed the heterogeneity of immunoreactive type-IV collagen (7S) and showed that these domains were composed mainly of degradation products of type-IV collagen. These data suggest that degradation of IVc is accelerated in the vascular basement membrane of NIDDM patients.

Correlation between nm23 protein and several cell adhesion molecules in human gastric carcinoma

The correlation between nm23 protein (nm23) expression and the expression of several cell adhesion molecules was studied immunohistochemically in 110 resected gastric carcinomas. Formalin-fixed and paraffin-embedded samples were serially sectioned and stained with antibodies against nm23, integrin beta1 subfamily members (alpha2beta1, alpha3beta1 and alpha4beta1), LFA-1, ICAM-1, sialyl Lewis(x) (sLex) and CD44H, -V3, and -V6. Primary carcinomas presenting with either lymph node involvement or liver metastasis expressed significantly reduced levels of nm23 compared to tumors without metastasis. The percent of tumors expressing each adhesion molecule was as follows: alpha2beta1, 27.3%; alpha3beta1, 20.0%; alpha4beta1, 14.5%; LFA-1, 14.5%; ICAM-1, 12.7%; sLex, 67.3%; CD44H, 55.5%; CD44V3, 20.0%; and CD44V6, 4.5%. Expression of alpha2beta1 integrin and high levels of sLex were significantly correlated with lymph node metastasis, and expression of alpha3beta1 integrin and high levels of sLex were correlated with liver metastasis. Expression of ICAM-1 was inversely correlated with liver metastasis. Comparing the expression of each cell adhesion molecule with nm23 immunoreactivity, expression of sLex was significantly associated with nm23 expression. Of tumors expressing high levels of sLex, 75% showed reduced nm23 expression, compared to 52% of tumors with weak or no sLex expression (P < 0.05). A similar tendency was also observed in the metastasized secondary tumors. These results suggest that reduced nm23 expression may promote the metastatic properties of cancer cells in concert with increased sLex expression.

Establishment and characterization of human gastric carcinoma lines with high metastatic potential in the liver: changes in integrin expression associated with the ability to metastasize in the liver of nude mice

There is a need to establish animal models which are suitable for investigation of human gastric cancer metastasis to the liver. To this end, a human gastric carcinoma line, AZ521 was injected into the spleens of nude mice. Cells from the few liver metastatic foci of injected AZ521 were expanded "in vitro" and subsequently injected into the spleens of nude mice. By repeating these procedures three times, we were able to obtain a cell line, designated as AZ-H3c, with high metastatic potential in nude mice. Liver metastasis developed in 15 of 21 (71%) animals injected with AZ-H3c, but only in 14% of those injected with parental AZ521. Further, AZ-H3c caused faster tumor development than did AZ521. However, the primary AZ-H3c tumors and liver metastatic AZ-H3c tumors showed essentially the same histological appearance. We also analyzed the cell surface expression of adhesion molecules. The data showed that the expression of VLA-1, VLA-2, VLA-3, VLA-4, VLA-5 was enhanced in AZ-H3c. In contrast, the expression of VLA-6, (alpha(v)beta3), E-cadherin, ICAM-1 and LFA-1 was reduced in this high-metastatic line. These results suggest that (beta1) integrins play an important role in the liver metastasis of human gastric carcinoma cells. Our high-metastatic line should be useful for studies aimed at the prevention of liver metastasis.

The significance of nm23 protein expression in human gastric carcinomas

The clinical significance of nm23 protein (nm23) expression was studied in tissue samples from 110 patients with primary gastric cancer by immunohistochemical staining with the anti-nm23 antibody. Primary carcinomas with either lymph node involvement or liver metastasis expressed significantly reduced levels of nm23 compared to those without metastasis. This relationship was clearer in the more differentiated adenocarcinomas than in the poorly differentiated adenocarcinomas. However, there was no correlation between nm23 expression and depth of invasion, quantity of stroma, infiltrating growth pattern, or macroscopic type. The cumulative 5-year survival rates based on nm23 immunoreactivity within the primary tumor were significantly higher in the nonreduced expression group (72%) than in the reduced expression group (45%). A multivariate analysis revealed that nm23 expression levels influence the outcome of patients as strongly as depth of invasion and more strongly than the other clinicopathological factors. These results suggest that the degree of nm23 expression is closely related to the metastatic potential of gastric carcinoma cells and can be used as a prognostic indicator independent of the clinicopathological features.

Cytotoxicity of simvastatin to pancreatic adenocarcinoma cells containing mutant ras gene

Simvastatin (SV), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, inhibits the synthesis of mevalonic acid. The dose-dependent (0.1-100 micrograms/ml) cytotoxicity of SV towards human (MIAPaCa-2, Panc-1, HPC-1, HPC-3, HPC-4, PK-1, PK-9) and hamster (T2) pancreatic carcinoma cell lines was determined by MTT assay. At up to 20 micrograms/ml of SV, the effect was reversible and was restored by 60 micrograms/ml mevalonic acid. Point mutation of Ki-ras at codon 12 in each cell line was detected by means of the modified polymerase chain reaction. The concentration of SV necessary to achieve 50% cytotoxicity was about 10 micrograms/ml, and at this concentration of SV, DNA synthesis assayed in terms of [3H]thymidine uptake, isoprenylation of p21ras examined by Western blotting and cell progression from G1 to S phase of the cell cycle analyzed by flow cytometry were all inhibited. Isoprenylation inhibitors of p21ras, such as SV, are expected to be useful for the treatment of pancreatic cancer.