Plasma level of a 5-fluorouracil metabolite, fluoro-beta-alanine correlates with dihydropyrimidine dehydrogenase activity of peripheral blood mononuclear cells in 5-fluorouracil treated patients

5-fluorouracil (5-FU) is mostly metabolized after administration, and the metabolizing enzyme, dihydropyrimidine dehydrogenase (DPD), seems to be the rate-limiting factor. However, there are few reports on the final metabolite, fluoro-beta-alanine (FBAL). We report here the results of determination of the FBAL level in 5-FU treated patients and the correlation between the FBAL level and the DPD activity in peripheral blood mononuclear cells (PBMCs). Blood samples were collected from 20 patients, who had received continuous intravenous infusion (CIV) of 5-FU (320 mg/m2/24 hr) after resection of colorectal cancer, and the FBAL level was determined by high performance liquid chromatography (HPLC), after derivatizing into o-phthalaldehyde (OPA) and detecting fluorescence. DPD activity was measured in cytosol prepared from PBMCs using HPLC radioassay. The average FBAL plasma level during CIV of 5-FU was 911.0 ng/ml (521.0 to approximately 1834.6 ng/ml) and that of DPD activity in PBMCs was 282.6 pmol/min/mg-protein (145.0 to approximately 568.0 pmol/min/mg-protein). There was a significant correlation between the FBAL level and the DPD activity (r=0.805, p<0.0001). FBAL level in plasma may be useful in predicting the DPD activity in PBMCs, however, further studies are required considering the small number of cases in this study.

Involvement of M(2) muscarinic receptors in relaxant response of circular muscle of mouse gastric antrum

Our previous study showed that atropine significantly inhibited the sustained relaxation induced by electrical field stimulation (EFS) in the circular muscle strips prepared from the mouse antrum, and that pituitary adenylate cyclase activating peptide (PACAP) partially mediated the sustained relaxation. The muscarinic receptor subtype associated with the sustained relaxation was examined in the present study by using each muscarinic receptor subtype of knockout (KO) mice. EFS-induced sustained relaxation in the antrum prepared from M(2) receptor KO mice was significantly less than that of wild-type mice. Atropine failed to inhibit this relaxation. On the other hand, similar sustained relaxation and inhibitory effects of atropine to those of wild-type mice were observed in M(1), M(3) and M(4) receptor KO mice. Exogenously added PACAP-27 relaxed the antral strips of wild-type and M(2) receptor KO mice to a similar extent. Immunohistochemical study revealed that M(2) receptor immunoreactivity was localized with PACAP-immunoreactivity in enteric neurons within the antrum of wild-type mice. In contrast, atropine did not affect the EFS-induced sustained relaxation in the gastric fundus. These results suggest that M(2) receptors modulate the sustained relaxation, probably through the regulation of PACAP release, in the mouse antrum.

Metastases-related genes in the classification of liver and peritoneal metastasis in human gastric cancer

INTRODUCTION

With the aim of identifying metastases-related genes in gastric cancer, we performed a broad analysis of differential gene expression between low-metastatic parental cell lines and established highly metastatic sublines.

MATERIALS AND METHODS

We established novel cell lines, AZ-H5c, NUGC-3H5, and TMK-1H7, with a high potential of liver metastasis, and AZ-P7a, NUGC-3P4T, and TMK-1P4a, with a high potential of peritoneal metastasis. These cell lines were derived from low-metastatic parental AZ-521, NUGC-3, and TMK-1 cell lines, respectively. Furthermore, to investigate different levels of gene expression implicated in metastatic potentials in gastric cancer, we investigated approximately 2000 expressed genes in each cell line using a DNA microarray.

RESULTS

Varieties of genes were up-regulated or down-regulated in highly metastatic liver and peritoneal cell lines. Fifty-eight genes, including the transferrin receptor, ras-related rho, and osteopontin, and 22 genes, including apolipoprotein E and inhibin A-submit, were up-regulated and down-regulated in two or three liver metastatic sublines. On the other hand, 19 genes, the transferrin receptor, c-fos, and RANTES, and 26 genes, including MAC25, PISSLRE, and RNA polymerase, were up-regulated and down-regulated in two or three peritoneal metastatic sublines.

CONCLUSION

How gene expression is implicated in gastric cancer metastasis has never been thoroughly explained, and further studies are necessary to understand the involvement of genes in cancer metastasis more thoroughly. We hope that our highly metastatic liver and peritoneal experimental models are helpful for further study and gene therapy of human gastric cancer.

[Pulmonary metastasis from colorectal cancer with hepatic metastasis]

We have investigated cases where pulmonary metastasis from colorectal cancer was resected during the last 15 years, comparing a group with liver metastasis [LM (+)] to a group without liver metastasis [LM (-)]. The following are the characteristics of the LM (+) versus LM (-) groups. Gender: male 6, female 5 versus male 9, female 11, age: 61.4+/-11.4 versus 63.9+/-9.4 years, number of lung metastasis: 1.42 versus 1.29, duration of primary-lung metastasis: 1.59+/-1.02 versus 2.55+/-1.46 years, preoperative CEA: 69.3+/-71.1 versus 8.64+/-5.63 ng/ml, ratio of bilateral lung metastasis: 23.0 versus 4.8%, more than 1 ratio of pulmonary metastasis: 38 versus 19%, complete resection ratio of pulmonary metastasis: 84.6 versus 100%, ratio of thoracoscopic surgery: 69.2 versus 66.7%, and 2-year survival ratio: 63 versus 78%. There were no statistically significant differences in these values between the LM (+) and LM (-) group. A larger number of cases and follow-up duration will be required in the future; we think that the resection of pulmonary metastasis from colorectal cancer with liver metastasis can be supported for the present.

Profiling analysis of differential gene expression between hematogenous and peritoneal metastatic sublines of human pancreatic cancer using a DNA chip

We established the novel sublines HPC-1H5, HPC-3H4, HPC-4H4, and Panc-1H5, which have a high potential of liver metastasis, and HPC-1P5a, HPC-3P4a, HPC-4P4a, and Panc-1P5a, which have a high potential of peritoneal dissemination, derived from low metastatic HPC-1, HPC-3, HPC-4, and Panc-1cell lines, respectively. To clarify the molecular mechanisms of cancer metastasis and of the different levels of gene expression in a variety of metastatic potentials in pancreatic cancer, we performed a broad analysis of differential gene expression analysis between parental cell lines and metastatic sublines. In comparison with the parental cell lines, 65 and 36 genes were overexpressed and underexpressed in highly liver-metastatic sublines. On the other hand, 43 and 45 genes were overexpressed and underexpressed in highly peritoneal-metastatic sublines. uPAR and Serin protease were overexpressed, and E2A and IGF1R were underexpressed in both metastatic sublines. Hierarchical clustering analysis revealed 22 genes classifying liver, peritoneal metastatic sublines and low-metastatic parental cell lines. These genes might be targeted genes separating those two major metastatic forms after surgery. A greater number of cell line samples and more genes will have to be utilized in future studies in order to understand the involvement of genes in cancer metastasis more thoroughly. However, these results will help to clarify the molecular mechanisms of pancreatic cancer metastasis.

Metastatic-associated biological properties and differential gene expression profiles in established highly liver and peritoneal metastatic cell lines of human pancreatic cancer

To elucidate metastasis mechanisms, we established a Panc-1H5 subline with a highly liver metastatic cell line and a Panc-1P4a with a highly peritoneal metastatic cell line, which were sequentially selected from the parental pancreatic cancer cell line Panc-1. Using these three cell lines, we investigated several biological properties and mRNA levels of differentially-expressed genes involved in cancer metastasis with a cDNA macroarray. The tumorigenicity, motile activity, adhesive activity and cytokine production of metastatic sublines were higher than those of parental Panc-1 cells. Particularly, in Panc-1H5 cells, adhesive activity to the extracellular matrix and angiogenetic factors increased, whereas in Panc-1P4a cells, motile activity was extremely enhanced compared with Panc-1 cells. Histopathological findings for the three cell lines were the same. In cDNA macroarray analysis of Panc-1H5 cells, 11 genes were up-regulated and 20 genes were down-regulated compared with parental Panc-1 cells. In Panc-1P4a cells, 7 genes were up-regulated and 13 genes were down-regulated compared with parental Panc-1 cells. This study provides a demonstration of global gene expression analysis of pancreatic cancer cells with liver and peritoneal metastasis and these results provide new insight into the study of human pancreatic cancer metastasis.

Differential gene expression screening between parental and highly metastatic pancreatic cancer variants using a DNA microarray

To clarify the difference in genes expressed in hematogenous metastasis and peritoneal dissemination, a broad analysis of differential gene expression analysis between parental cell lines and established metastatic sublines was performed. Using an oligonucleotide array (Gene Chip, Affymetrix), approximately 2,000 genes involved in cancer were analyzed for each of the cell lines. HPC-4H4 (highly metastatic lines to the liver) compared with HPC-4 (low metastatic parental lines), in which 20 overexpressed genes and 5 underexpressed genes were recognized. HPC-4P4a (highly metastatic to the peritoneum) compared with HPC-4, in which 12 overexpressed genes and 15 underexpressed genes were also recognized. Analysis of HPC-4H4 and HPC-4P4a showed comparative up-regulation of 20 genes and down-regulation of 13 in the former, HPC-4H4. Further studies are needed to validate our hypothesis that some of the resulting differentially expressed genes might be implicated in the development of metastasis in pancreatic cancer. In conclusion, this genome-wide expression analysis will help to clarify the molecular mechanisms of cancer metastasis and of the different levels of gene expression in a variety of metastatic potentials in pancreatic cancer.

Expression analysis of vascular endothelial growth factors and their relationships to lymph node metastasis in human colorectal cancer

This study was undertaken to determine whether expressions of the vascular endothelial growth factor (VEGF) family (VEGF-A, VEGF-B, VEGF-C, and VEGF-D) are correlated with clinicopathological parameters, with particular reference to lymph node metastasis in colorectal cancer. Total RNA was isolated from 82 surgical specimens of colorectal cancer and matched to normal mucosa with (n = 41) or without (n = 41) lymph node metastasis. The mRNA expression of each VEGF family member was quantified by real-time quantitative (RTQ) RT-PCR assay. VEGF-B and VEGF-C mRNA were significantly higher both in the tumors with lymph node metastasis (p = 0.027 and p = 0.024, respectively) and in tumors with lymphatic invasion (p = 0.042 and p = 0.005, respectively). In contrast, VEGF-D mRNA was down-regulated in tumors with lymphatic involvement (p = 0.047). Among the other clinicopathological factors, we noted that VEGF-A mRNA was higher in tumors with liver metastasis than in those without (p = 0.018) and was higher in tumors with venous invasion than in those without (p = 0.007). The results of this study demonstrate that high levels of VEGF-B, C and low levels of VEGF-D mRNA expression are associated with lymph node metastasis and lymphatic involvement. These results suggest that a balance among VEGF-B, VEGF-C, and VEGF-D might contribute to the lymphangiogenic process and metastasis in colorectal cancer.

High dorsal drainage routes of Spiegel's lobe

BACKGROUND/PURPOSE

The venous drainage from Spiegel's lobe to the terminal portion of the hepatic veins has been described in the literature, but its morphology remains unclear.

METHODS

We examined 42 dissected liver specimens and 38 cast specimens.

RESULTS

In 8 of the 42 dissected liver specimens and 5 of the 38 cast specimens we found atypical but thick (over 3 mm) caudate veins that drained Spiegel's lobe and emptied into the terminal portion (along the most proximal 5-mm course) of the middle hepatic vein (MHV) or the inferior vena cava (IVC) near the MHV terminal (less than 10 mm from the MHV). We termed these the superior caudate vein. This vein ran upward between the caudate portal branches of the left and hilar bifurcation origins or through the territory of the left origin. The superior caudate vein, consistently coexisted with the typical vein(s). We also found several analogues of the superior caudate vein, such as the cranially shifted opening of the typical caudate vein and relatively thick proximal tributaries of the MHV from Spiegel's lobe.

CONCLUSIONS

Although the superior caudate vein, if present, seemed to have a large role in the venous drainage of the lobe, its incidence seemed to be too low for clinical relevance.

Effect of 1DMe, a neuropeptide FF analog, on acetylcholine release from myenteric plexus of guinea pig ileum

Since neuropeptide FF (NPFF) is a putative neurotransmitter to exert anti-opioid activity, we examined the effects of [D-Tyr', (NMe)Phe3]neuropeptide FF (IDMe), a stable NPFF analog, on acetylcholine (ACh) release from a longitudinal muscle-myenteric plexus (LMMP) preparation of guinea pig ileum in which opioids were known to inhibit ACh release when muscarinic autoinhibition was not fully activated. In the presence of atropine, 1DMe increased spontaneous and electrical field stimulation (EFS)-evoked ACh release in a concentration-dependent manner. Naloxone also increased ACh release. The stimulatory effects of 1DMe and naloxone were not additive. In the absence of atropine, 1DMe did not affect ACh release. Morphine decreased spontaneous and EFS-evoked ACh release in the presence of 1 microM atropine. 1DMe as well as naloxone counteracted the inhibitory effects of morphine on EFS-evoked ACh release. The combination of 1DMe and naloxone was not more inhibitory than either drug alone. 1DMe had no appreciable effect on norepinephrine-induced inhibition of spontaneous and EFS-evoked ACh release. These results first demonstrated the effects of a NPFF analog on neurotransmitter release: 1DMe had a stimulatory effect on spontaneous and EFS-induced ACh release from the LMMP preparation of guinea pig ileum, probably by counteracting the inhibitory effect of endogenous opioids on ACh release.

Origin of Ca2+ necessary for carbachol-induced contraction in longitudinal muscle of the proximal colon of rats

The origin of Ca2+ necessary for carbachol (CCh)-induced contraction of longitudinal muscle of the proximal colon of rats was studied. CCh induced contraction of the muscle consisting of two phases, phasic and tonic phases, with a concomitant biphasic increase in [Ca2+]i. After removal of Ca2+ from the bathing solution of the colonic segments, CCh-induced contraction was rapidly inhibited; there was almost complete inhibition 1 min after the removal. Nicardipine, a blocker of voltage-dependent calcium channel, also significantly inhibited CCh-induced contraction. On the other hand, treatment of the colonic segments with thapsigargin, an inhibitor of sarcoplasmic reticulum (SR) Ca2+-ATPase, did not significantly affect the contraction except causing a slight decrease in the rate of contraction. These results suggest that Ca> entering through voltage-dependent calcium channels, but not released from SR, is essential for CCh-induced contraction of longitudinal muscle of the proximal colon of rats. This strict dependency of the CCh-induced contraction on extracellular Ca2+ was discussed in relation to the results obtained in the fundus of rats.

NGF induces neurite outgrowth via a decrease in phosphorylation of myosin light chain in PC12 cells

The relationship between phosphorylation of myosin light chain (MLC) and neurite outgrowth induced by nerve growth factor (NGF) was studied in PC12 cells. Inhibitors of Rho kinase, HA-1077 or Y-27632 also induced neurite outgrowth. As already reported botulinum exoenzyme C3 which inactivates Rho protein also induced neurite outgrowth. Calyeulin A, an inhibitor of phosphatase counteracted both NGF- and C3- induced neurite outgrowth. Treatments of both NGF and C3 resulted in significant and transient decrease in phosphorylated MLC. These results suggest that NGF induces neurite outgrowth of PC12 by a transient decrease in phosphorylated MLC which is brought about by activation of MLC phosphatase via inhibition of Rho-Rho kinase pathway.

Expression of Ca(2+)-activated K(+) channels, SK3, in the interstitial cells of Cajal in the gastrointestinal tract

A role for small-conductance Ca(2+)-activated K(+) (SK) channels on spontaneous motility of the gastrointestinal tract has been suggested. Although four subtypes of SK channels were identified in mammalian tissues, the subtypes of SK channel expressed in the gastrointestinal tract are still unknown. In this study, we investigated the expression and localization of SK channels in the gastrointestinal tract. RT-PCR analysis shows expression of SK3 and SK4 mRNA, but not SK1 or SK2 mRNA, in the rat intestine. SK3 immunoreactivity was detected in the myenteric plexus and muscular layers of the stomach, ileum, and colon. SK3-immunoreactive cells were stained with antibody for c-kit, a marker for the interstitial cells of Cajal (ICC), but not with that for glial fibrillary acidic protein in the ileum and stomach. Immunoelectron microscopic analysis indicates that SK3 channels are localized on processes of ICC that are located close to the myenteric plexus between the longitudinal and circular muscle layers and within the muscular layers. Because ICC have been identified as pacemaker cells and are known to play a major role in generating the regular motility of the gastrointestinal tract, these results suggest that SK3 channels, which are expressed specifically in ICC, play an important role in generating a rhythmic pacemaker current in the gastrointestinal tract.

Blood supply to the duodenal papilla and the communicating artery between the anterior and posterior pancreaticoduodenal arterial arcades

The communicating artery (ComA) between the anterior and posterior pancreaticoduodenal arterial arcades is little understood, although it has been described several times during the past 100 years. In 44 of 51 cadaveric specimens in the present study, the typical ComA was observed to pass between the major and accessory pancreatic ducts. In addition, a second ComA was sometimes found crossing inferior to the major pancreatic duct. The typical ComAs often (36 of the 44) issued papillary branch(es). Although direct papillary branches of the posterior arcade were often observed to either coexist with (9 specimens) or exist independently (4 specimens), the ComA-derived branch seemed to be critical for papillary blood supply, because of its shorter length, greater thickness, and higher frequency. Moreover, the typical ComA could be a good landmark during limited pancreatic resection, such as duodenum-preserving subtotal resection of the pancreatic head or pancreatic segment resection, because the artery is likely to be an indicator of the borders between the celiac and superior mesenteric arterial territories, as well as those between the ventral and dorsal segments of the pancreas.

Possible role of orexin A in nonadrenergic, noncholinergic inhibitory response of muscle of the mouse small intestine

The effect of a novel peptide, orexin A, on longitudinal muscle of ICR mouse small intestine was examined in vitro. Exogenous orexin A induced a transient contraction in duodenal, jejunal and ileal segments. Atropine and tetrodotoxin completely inhibited the contractions. Contraction of longitudinal muscle of jejunal segments induced by electrical field stimulation was still observed after the jejunal segment had been desensitized to orexin A, suggesting that orexin A is not a final neurotransmitter to induce the contraction. On the other hand, in the presence of atropine and guanethidine, orexin A induced a transient gradual relaxation in duodenal, jejunal and ileal segments. Electrical field stimulation also induced significant relaxation of the muscle in jejunal segments. The electrical field stimulation-induced relaxation was inhibited by 55% after the desensitization of the segments to orexin A. Although the electrical field stimulation-induced relaxation was inhibited by 47% by a nitric oxide synthesis inhibitor, NG-nitro-L-arginine (L-NOARG), orexin desensitization did not affect the relaxation which persisted after L-NOARG treatment. The exogenous orexin A-induced relaxation was completely inhibited by L-NOARG. The results suggest that orexin A partially mediates nonadrenergic, noncholinergic (NANC) relaxation via activation of nitrergic neurones in longitudinal muscle of ICR mouse small intestine.

Ventral margin of the paracaval portion of human caudate lobe

The topographic anatomy of the ventral margin of the caudate lobe of the human liver is still obscure. We hypothesized the existence of a "precaudate plane", as a flat or slightly curved plane defined by the ventral margins of both the ligamentum venosum and hilar plate. Using 61 cadaveric liver specimens, without great differences in external shape or significant variations in the hilar bifurcation, we examined whether the paracaval caudate branches (PCs) ran through the plane to the ventral side. In 22 of the 61 specimens (36.1%), the PC extended over the plane for less than 10 mm (10 specimens), for 10-20 mm (7 specimens), or for more than 20 mm (5 specimens). The ventral extension consistently included the dome-like area under the terminals of the middle and right hepatic veins. Therefore, the ventrally extended PCs often interdigitated with these veins and their tributaries. The ventral extension often reached the upper, diaphragmatic surface. However, several branches were too difficult to discriminate from the PC, especially those with morphologies intermediate between the PC and segmental portal branches to S4 or S2. We discuss how to identify and manage the ventrally extended PCs before and during surgery.

Sepsis and cholestasis: basic findings in the sinusoid and bile canaliculus

It is well known that the liver plays a major role in the clearance of systemic toxemia and is postulated as a regulational organ in the host-defense system. The well-controlled interaction between hepatic parenchymal cells and sinusoidal lining cells including macrophages and Kupffer cells can systematically regulate even critical infections. However, when patients are under the overload condition caused by severe infection, rejection of a transplanted liver and other hapatic dysfunction often are experienced following surgery. Among various signs and symptoms of hepatic dysfunction, progressive cholestasis is recognized as a polarized representation of the irreversible changes in hepatic constitutional cellular functions, especially in hepatic parenchymal cells. Bile canaliculi, the smallest components of the biliary tree, lie between the apical surfaces of adjacent hepatocytes. Septic cholestasis might be a result of disturbance of the total bile canalicular system, i.e., bile secretion, canalicular contraction, and so on. Recently, the molecular biology of the hepatocellular transport system has become better understood, and the pathophysiological condition of cholestasis can be explained as a representation of the intracellular molecular transcriptional system. Cellular changes in surgical cholestasis and molecular findings concerning the bile canaliculus are introduced in this article.

Ramification pattern and topographical relationship between the portal and hepatic veins in the left anatomical lobe of the human liver

Sixty-one human livers obtained from donated Japanese adult cadavers were dissected to reveal the ramification pattern of the portal and hepatic veins, and their topographical relationship in the left anatomical lobe. The segmental portal vein supplying S2 (P2) tended to form a single stem, whereas that of S3 (P3) was usually double. An intermediate branch between P2 and P3 was observed in 23.0% of livers. In spite of variation between livers, definite P2 and P3 were identified in 47 specimens. One tributary of the left hepatic vein (LHV) was usually present for drainage of S2, and two tributaries were present for S3 (sometimes also for S2 and/or S4). The latter two tributaries of the LHV and the two subsegmental branches of S3 showed three patterns of three-dimensional interdigitations. From these results, the portal vein system did not seem to have a two segmental composition (i.e., S2 and S3) in 23.0% of specimens, whereas the hepatic vein system did not have an intersegmental course in 23.4%. Thus, there were obvious limitations in using each system to determine the liver segment. Taking the overlapping cases into consideration, the left anatomical lobe of 41.0% of specimens did not seem to fit the definition of Couinaud's liver segment. In addition, four patterns of fissure vein (or scissural vein), > 5 mm in diameter at its terminal, were identified: (1) middle hepatic vein type (left median vein, 9.8%); (2) LHV type (left medial vein, 41.0%); (3) true fissure vein (3.3%); and (4) absent cases (45.9%). The former two types also suggested limitations of the hepatic vein system as an indicator of the segmental border.

Effect of 1DMe, a neuropeptide FF analog, on acetylcholine release from myenteric plexus of guinea pig ileum

Since neuropeptide FF (NPFF) is a putative neurotransmitter to exert anti-opioid activity, we examined the effects of [D-Tyr', (NMe)Phe3]neuropeptide FF (IDMe), a stable NPFF analog, on acetylcholine (ACh) release from a longitudinal muscle-myenteric plexus (LMMP) preparation of guinea pig ileum in which opioids were known to inhibit ACh release when muscarinic autoinhibition was not fully activated. In the presence of atropine, 1DMe increased spontaneous and electrical field stimulation (EFS)-evoked ACh release in a concentration-dependent manner. Naloxone also increased ACh release. The stimulatory effects of 1DMe and naloxone were not additive. In the absence of atropine, 1DMe did not affect ACh release. Morphine decreased spontaneous and EFS-evoked ACh release in the presence of 1 microM atropine. 1DMe as well as naloxone counteracted the inhibitory effects of morphine on EFS-evoked ACh release. The combination of 1DMe and naloxone was not more inhibitory than either drug alone. 1DMe had no appreciable effect on norepinephrine-induced inhibition of spontaneous and EFS-evoked ACh release. These results first demonstrated the effects of a NPFF analog on neurotransmitter release: 1DMe had a stimulatory effect on spontaneous and EFS-induced ACh release from the LMMP preparation of guinea pig ileum, probably by counteracting the inhibitory effect of endogenous opioids on ACh release.

Mechanism of a nitric oxide donor NOR 1-induced relaxation in longitudinal muscle of rat proximal colon

We previously suggested that nitric oxide (NO)-mediated relaxation of the rat proximal colon is not associated with change in cyclic GMP content. We further studied the intracellular mechanism of NO-induced relaxation by measuring changes in tension and intracellular Ca2+ concentration ([Ca2+]i), simultaneously. NOR 1, NO donor, relaxed the longitudinal muscle of the rat proximal colon, which was precontracted by carbachol, with a concomitant decrease in [Ca2+]. ODQ, an inhibitor of soluble guanylate cyclase, partially inhibited the relaxant effect of only higher concentrations of NOR 1, but Rp-8-Br-cGMPS, an inhibitor of cyclic GMP-dependent protein kinase (PKG), did not have any effects on the relaxant effect of NOR 1. When the preparations were transferred to normal solution after the treatment with thapsigargin, an inhibitor of sarcoplasmic reticulum (SR) Ca2+-ATPase, in the absence of Ca2+, contraction with a concomitant increase in [Ca2+]i occurred. NOR 1 did not show significant effects on the tension and [Ca2+]i in thapsigargin-treated preparations. In high K+-precontracted preparations, NOR 1 relaxed the preparations with a slight change in [Ca2+]i. The relaxant effect was significantly inhibited by ODQ and Rp-8-Br-cGMPS. These results suggest that NO induces the relaxation preferentially by acting thapsigargin-sensitive function of SR and in turn decreasing [Ca2+]i, although a cyclic GMP-PKG pathway is suggested under the experimental conditions of a high K+ concentration.

A novel experimental mouse model of peritoneal dissemination of human gastric cancer cells: analysis of the mechanism of peritoneal dissemination using cDNA macroarrays

We established a new cell line, NUGC-3P4T, with high peritoneal metastatic disseminating potential in nude mice. NUGC-3P4T cells were derived from the human gastric carcinoma line NUGC-3, which has low capacity for peritoneal dissemination. NUGC-3P4T cells developed peritoneal dissemination in 10 / 10 (100%) mice, whereas the parental NUGC-3 cells developed dissemination in 1 / 5 (20.0%) mice. The metastatic foci in the peritoneum showed essentially the same histological appearance as those induced by parental cells. The tumorigenicity, the motile activity and the adhesive activity to the laminin of NUGC-3P4T cells were stronger than those of NUGC-3 cells. Production of IL-8 was significantly higher in NUGC-3P4T than in NUGC-3. cDNA macroarrays analysis showed that a variety of cytokines, interleukins, and other immunomodulators and their receptors were up- or down-regulated at the mRNA level in NUGC-3P4T cells, compared with NUGC-3 cells. Thus, this unique cell line and in vivo model might be useful to study the biology of peritoneal dissemination of human gastric cancer.

Adenosquamous carcinoma of the colorectum: report of two cases

Adenosquamous carcinomas of the colorectum are rare neoplasms. Our experience with two cases is presented in this paper. One patient, who complained of bloody stool, was found to have adenocarcinoma in the sigmoid colon. He received a laparoscopy-assisted sigmoidectomy. The histological examination revealed that the tumor was adenosquamous carcinoma. To date, he has survived six months post operatively without evidence of recurrence. The other patient, who complained of anal bleeding, was found to have rectal adenocarcinoma and received a low anterior resection. Histological examination revealed that the tumor was an adenosquamous carcinoma. He remains alive, with no evidence of recurrence, nine years post operatively. Both cases showed paracolic lymph node metastasis. Because of its very low incidence, the histogenesis, malignancy and prognosis of this disease remain unclear. Thus, further clinical and histological study of this disease entity is required.

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 segment S2 is consistently located at the dorsal side of S3 but sometimes at the right and/or caudal side of S3

After preparing the frontal section including the origin of the left portal trunk at the hilar region, the left anatomical lobes of 111 human livers were dissected to reveal the segmental configuration based on the supplying portal vein branches. S2 was consistently located dorsal to S3. However, in contrast to the description in common textbooks for medical students, 19.8% of the specimens carried a paradoxical segmental configuration showing a "caudal and/or rightward" S2 in combination with a "cranial and/or leftward" S3 in the frontal section through the ventral part of the hilar region. The caudal and rightward cases were associated with a specific arrangement of S2 and S3 segmental stems in which the S3 stem ran relatively upward to spread over S2 or both stems ran almost horizontal, respectively. In routine diagnostic radiology, identification of S2 and S3 might sometimes be biased by the generally accepted notion that S2 should be located at the dorsal, cranial and left side of S3.

[Configuration of the liver segment observed in the frontal section including the origin of the left portal trunk at the hepatic hilum]

After preparing threparing the frontal section including the origin of the left portal trunk at the hepatic hilum, 60 human livers (35, entirely; 25, partly) were dissected to reveal segmental configuration and the supplying portal vein branches. We usually observed two combinations of segments, i.e., S2, 4, 5 and 8 or S2, 3, 4, 5 and 8, in the frontal section including the origin of the left portal trunk. However, S8 was sometimes absent in the section when S4 extended to the right and/or upper side. S2 was consistently located dorsal to S3 despite the fact that 11.7% of the specimens carried an unexpected configuration showing a "lower" S2 in combined with an "upper" S3 in the frontal section. The latter case was associated with specific S2 and S3 segmental branches maintaining horizontal courses along a common plane. S4, S5 and S8 were usually arranged from the ventral to the dorsal aspect in this order. Four types of ventral short branches originated at or near the primary portal divisions and supplied the hilar parenchyme adjacent to S4 and/or the anterior segment (S5 or S8). These ventral short branches tended to be associated with the variations of the primary division. Dissection of the liver after frontal section provided a better understanding of the segmental configuration rather than an approach from the hepatic hilum.

Configuration of the right portion of the caudate lobe with special reference to identification of its right margin

The configuration of the right portion of the caudate lobe (CL), and especially the exact location of its right margin, remains obscure. This study aimed to identify this right margin according to reliable landmarks suitable for use during clinical examinations and surgery: (1) the bifurcation of the right portal vein, (2) the end of the right hepatic vein, and (3) the notch on the gallbladder fossa. The plane defined by these three landmarks is called the right paracaval plane. Dissection of 55 livers demonstrated that the entire CL was usually contained within the left half of the specimen after cutting along the right paracaval plane (Type A: 65.4%, 36/55). However, its right portion sometimes extended beyond this plane into the right half of the liver (34.6%, 19/55), forming one or two islands when viewed from the paracaval plane (Types B and C). We found two separate marginal configurations among the 19 rightward extensions of the paracaval portion: a tree-like, deep protrusion (11/19) and a relatively smooth border (8/19). The present results suggest the existence of reliable landmarks that will allow a right-side limit for surgical resection of the CL to be established: (1) the right paracaval plane (60% reliability), (2) 10 mm to the right of the plane, including the terminal of the right hepatic vein (80% reliability), and (3) the widest margin, including the 30 mm to the right of the right paracaval plane, the right side running along the inferior vena cava, and the diaphragmatic surface around the end portions of the three main hepatic veins (100% reliability).

Configuration of the right portion of the caudate lobe with special reference to identification of its right margin

The configuration of the right portion of the caudate lobe (CL), and especially the exact location of its right margin, remains obscure. This study aimed to identify this right margin according to reliable landmarks suitable for use during clinical examinations and surgery: (1) the bifurcation of the right portal vein, (2) the end of the right hepatic vein, and (3) the notch on the gallbladder fossa. The plane defined by these three landmarks is called the right paracaval plane. Dissection of 55 livers demonstrated that the entire CL was usually contained within the left half of the specimen after cutting along the right paracaval plane (Type A: 65.4%, 36/55). However, its right portion sometimes extended beyond this plane into the right half of the liver (34.6%, 19/55), forming one or two islands when viewed from the paracaval plane (Types B and C). We found two separate marginal configurations among the 19 rightward extensions of the paracaval portion: a tree-like, deep protrusion (11/19) and a relatively smooth border (8/19). The present results suggest the existence of reliable landmarks that will allow a right-side limit for surgical resection of the CL to be established: (1) the right paracaval plane (60% reliability), (2) 10 mm to the right of the plane, including the terminal of the right hepatic vein (80% reliability), and (3) the widest margin, including the 30 mm to the right of the right paracaval plane, the right side running along the inferior vena cava, and the diaphragmatic surface around the end portions of the three main hepatic veins (100% reliability).

Takayasu arteritis. Treatment and prognosis in a university center in Brazil

The aim of this study was to evaluate the treatment and evolution of TA patients in a University Center in Brazil. This is a retrospective and descriptive study, that included all patients with TAs who attended the out-patient clinic at the Universidade Federal de Sao Palo, between 1993 and 1998. Twenty-four patients were women and 22 where white. The median age at the time of diagnosis was 27 yo. Full arteriography was performed in 28 patients and carotid duplex ultrasound plus computed tomography of aorta was done in two patients. Type I was found in 4, type II-a and type II in one case each, the type IV in 4 cases and the type V in 20 patients. Regarding the treatment only three patients with quiescent disease did not receive any medications. Twenty-seven patients (90%) received prednisone and only ten of these patients achieved disease control. Forth-eight percent of patients who received prednisone showed some side effects. Twelve patients received methotrexate associated to prednisone and 58% of them had a good response. Two patients who did not control disease activity with prednisone plus methotrexate received cyclophosphamide without good results. Some surgical procedure was performed in ten TA patients. Three patients died during the follow-up. This study showed that the majority of TA patients attended at a University Center needed association of prednisone and methotrexate to control disease activity, 30% needed some surgical procedures and that may be a cause of death in a young patient.

Mediators of nonadrenergic, noncholinergic relaxation in Sprague Dawley rat intestine: comparison with the mediators of other strains

Participation of nitric oxide, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) in nonadrenergic, noncholinergic (NANC) relaxation of longitudinal muscle of various intestinal regions in Sprague Dawley rats (8-week-old) was studied in vitro. Nitric oxide was suggested to participate in NANC relaxation of every intestinal region studied. But the participation was partial and its extent varied among the regions: significant in the proximal colon and rectum, and moderate in the jejunum, ileum and distal colon. Participation of PACAP in NANC relaxation was suggested only in the distal colon, while that of VIP was not detected in any of regions. Results obtained in the present study indicate that extent of participation of nitric oxide in NANC relaxation in Sprague Dawley rat intestine is more significant than those of other strains, Wistar and Wistar-ST.

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.

[Weekly low-dose CPT-11 and HCFU for advanced colorectal cancer on an outpatient treatment basis]

We attempted a new outpatient treatment using weekly low-dose CPT-11 for advanced colorectal cancer patients. A 73-year-old female with para-aortic lymph node metastases from advanced rectal cancer was given outpatient treatment for more than 5 months with weekly low-dose CPT-11 and HCFU. CPT-11 was given intravenously at a dose of 20 mg/m2 on day 1 every week. On days 2-7, she was treated by oral administration of HCFU (600 mg). Her serum CEA level decreased and continued to do so for more than 5 months. The size of the para-aortic lymph node was reduced by approximately 40%. There were no adverse effects except leukopenia (grade 2). These results suggest that weekly low-dose CPT-11 and oral HCFU may be an effective therapy on an outpatient basis in cases of advanced colorectal cancer.

Possible role of potassium channels in mu-receptor-mediated inhibition and muscarinic autoinhibition in acetylcholine release from myenteric plexus of guinea pig ileum

It is known that mu-agonists inhibit electrical field stimulation (EFS)-evoked ACh release from longitudinal muscle myenteric plexus (LMMP) preparation of guinea pig ileum when muscarinic autoinhibition does not fully work. In the present study, the possible role of K+ channels in the mechanisms of mu-agonists-induced inhibition and autoinhibition of ACh release was studied. In the presence of atropine, which blocks the autoinhibition, non-selective K+ channel blockers, tetraethylammonium (TEA) and 4-aminopyridine (4-AP), reversed the inhibitory effect of mu-agonists, morphine and [D-Ala2, N-Me-Phe4, Gly5-ol] enkephalin, on EFS-evoked ACh release, but not that of kappa-agonist U-50,488. Apamin, iberiotoxin or glibenclamide did not affect the inhibition of ACh release by morphine. On the other hand, in the absence of atropine (under the autoinhibition working condition), 4-AP increased EFS-evoked ACh release, but atropine did not further increase ACh release in the presence of 4-AP. In contrast, although TEA did not affect EFS-evoked ACh release, atropine increased ACh release in the presence of TEA. These results suggest that the inhibitory effects of mu-agonists and muscarinic autoinhibition on the ACh release are associated with activation of different types of K+ channels in the guinea pig LMMP preparations: the former is associated with 4-AP- and TEA-sensitive K+ channels and the latter is associated with 4-AP- but not TEA-sensitive K+ channels.

1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) inhibits cyclic GMP-PKG pathway-independent nonadrenergic, noncholinergic relaxation in longitudinal muscle of the rectum of Wistar-ST rats

Participation of the nitric oxide-cyclic GMP pathway in nonadrenergic, noncholinergic (NANC) relaxation induced by electrical field stimulation of longitudinal muscle of the rectum of Wistar-ST rats was studied by using a selective inhibitor of soluble guanylyl cyclase, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). ODQ concentration dependently inhibited the relaxation and at 10 microM, maximally inhibited it by 83%. However, results obtained with N(G)-nitro-L-arginine, L-arginine and exogenously added nitric oxide excluded the participation of nitric oxide in the relaxation. An inhibitor of cyclic GMP-dependent protein kinase (PKG) partially (39%) inhibited the relaxation. ODQ also significantly inhibited the relaxation, which persisted after the PKG inhibitor-treatment, by 85%. The results strongly suggest that ODQ inhibits the NANC relaxation in a cyclic GMP-PKG pathway-independent manner.

Differences in mediator of nonadrenergic, noncholinergic relaxation of the distal colon between Wistar-ST and Sprague-Dawley strains of rats

Participation of nitric oxide and vasoactive intestinal peptide (VIP) in electrical field stimulation-induced nonadrenergic, noncholinergic (NANC) relaxation of longitudinal muscle and in balloon distension-induced descending NANC relaxation of circular muscle were studied in the distal colon of Wistar-ST and Sprague-Dawley rats. The extent of the nitric oxide-mediated component was approximately 50% in longitudinal and circular muscle of Sprague-Dawley rats, whereas this component was absent in both muscles of Wistar-ST rats. The extent of the VIP-mediated component was approximately 40% in longitudinal muscle of Wistar-ST rats and circular muscle of Sprague-Dawley rats, whereas this component was absent in circular muscle of Wistar-ST rats and longitudinal muscle of Sprague-Dawley rats. In circular muscle of Sprague-Dawley rats, in which participation of both nitric oxide and VIP in the relaxation was suggested, inhibition of descending relaxation by N(G)-nitro-L-arginine (L-NOARG) together with VIP-(10-28) was similar to that by either of the antagonists, and exogenous VIP-induced relaxation was not affected by L-NOARG, but exogenous nitric oxide-induced relaxation was partly inhibited by VIP-(10-28). These results suggest a linkage of the pathways mediated by nitric oxide and VIP. In the immunohistochemical studies, nitric oxide synthase or VIP immunoreactive neurons were seen in the ganglia, primary internodal strands of the myenteric plexus and in the circular muscle layer. However, the overall appearance of immunoreactive cell bodies in the myenteric plexus and the numbers of immunoreactive fibers in the circular muscle layer appeared to be similar in Wistar-ST and Sprague-Dawley rats. These results suggest that mediators of NANC relaxation in the distal colon are different in different strains of rats, i.e., Wistar-ST and Sprague-Dawley, although no such difference was seen in immunohistochemical studies.

Involvement of cyclic AMP - PKA pathway in VIP-induced, charybdotoxin-sensitive relaxation of longitudinal muscle of the distal colon of Wistar-ST rats

The intracellular mechanism of vasoactive intestinal peptide (VIP)-induced, charybdotoxin (ChTx)-sensitive relaxation of longitudinal muscle of the distal colon of Wistar-ST rats was studied. A single pulse or 100 pulses at 10 Hz of electrical field stimulation (EFS) induced rapid transient relaxation or that with a subsequent contraction of the longitudinal muscle in the presence of atropine and guanethidine, respectively. Rp-8 bromo cAMPS, an inhibitor of cyclic AMP dependent protein kinase (PKA), at 30 microM inhibited the relaxations induced by EFS with a single or 100 pulses maximally by about 80 or 60%, respectively. It also inhibited VIP (300 nM)-induced relaxation by 82%. VIP (100 nM - 1 microM) increased the cyclic AMP content of longitudinal muscle myenteric plexus preparations obtained from the distal colon. ChTx at 100 nM almost completely inhibited 8 bromo cyclic AMP-induced relaxation of the distal segments. EFS with two or three pulses at 10 Hz induced inhibitory junction potentials consisting of two phases, rapid and subsequent slow hyperpolarization in the membrane potential of longitudinal smooth muscle cells. Rp-cAMPS, another inhibitor of PKA, inhibited the delayed slow hyperpolarization. It also inhibited the exogenously added VIP-induced hyperpolarization of the cell membrane. Thus, the present study suggests that activation of PKA via activation of VIP receptors is associated with activation of ChTx-sensitive K(+) channels in relaxation of longitudinal muscle of the distal colon of Wistar-ST rats. British Journal of Pharmacology (2000) 129, 140 - 146

High-resolution immunogold cytochemistry indicates that AQP4 is concentrated along the basal membrane of parietal cell in rat stomach

Gastric parietal cells secrete hydrochloric acid in stomach. Because the secreted HCl solution is isotonic with the plasma fluid, it should accompany the water transport across the membranes of parietal cells. Aquaporins (AQPs) are water channel proteins that play the central role in the cellular handling of water in various mammalian tissues. Using immunocytochemistry, we found that AQP4 was expressed only in parietal cells of rat gastric mucosa. Immunogold electron microscopy study further demonstrated that AQP4 was mostly localized at the basal membrane of parietal cells. In the basal membrane, AQP4 was prominently enriched on the portion contacting with the basement membrane surrounding gastric glands. These results suggest that the contact between basement membrane and basal membrane may generate the signal involved in the targeting of AQP4 in gastric parietal cells.

[Combination chemotherapy of continuous infusion 5-FU and daily low-dose CDDP in colorectal carcinoma]

Continuous intravenous infusion (CVI) of 5-fluorouracil (5-FU) plus daily low-dose cisplatin (CDDP) was evaluated in 59 patients with advanced and unresectable colorectal carcinoma. The procedure consisted of 5-FU 320 mg/m2/day, CVI and CDDP 2.5-3.5 mg/m2/day, infused for one hour five times a week (low-dose FP therapy) was performed for at least four weeks. The rates of complete and partial response, along with side effects were studied. Also, the effect of low-dose FP therapy on the prognosis of patients with colorectal carcinoma was investigated. The rate of complete and partial response was 57.1%. The frequency of severe side effects (grade 3 and 4) was 10.5%, and no death from side effects was noted. The effect of low-dose FP therapy on the prognosis of advanced and unresectable colorectal carcinoma was studied. It is suggested that this chemotherapy might contribute to the survival of patients with colorectal carcinoma. We designed the chemotherapy of intermittent administration (day by day) of 5-FU 600 mg/m2/day and daily CDDP 2.5-3.5 mg/m2/day (intermittent FP) in order to decrease the rate of side effects and their severity. No cases with grade 3 or 4 side effects were experienced, but the response rate was mostly similar to that of low-dose FP therapy. We concluded that low-dose FP and intermittent FP therapy might be fairly effective for advanced and unresectable colorectal carcinoma.

Vascular anatomy of the pancreaticoduodenal region: A review

Vascular anatomy of the pancreaticoduodenal region has been the subject of numerous studies. However, several essential areas of confusion remain in interpretation of the vascular configuration. We note and discuss three key points in relation to this confusion: (1) a missing vascular arcade, (2) a rearrangement of the arcade by collateral and/or transverse vessels, and (3) a solitary vessel without an accompanying comites vein or artery. In addition, we consider that different interpretations as well as varying reported incidences depend on different "thresholds" when observations are made. Consideration of new aspects of vascular anatomy of the pancreaticoduodenal region is required for further improvement of surgical procedures. In terms of the selection of lymph node resection procedure, we discuss mainly the inferior arterial origin. Special attention should be paid to the ligation of inferior arteries because of the high incidence of the common trunk formation of the upper jejunal and inferior pancreaticoduodenal arteries. With regard to duodenum-preserving pancreatic head resection for benign tumors, our observations are introduced in view of either arterial or venous configuration. First, a communicating artery between the anterior and posterior arterial arcades is noted because of its possible critical role in blood supply to the papilla of Vater. Second, a venous drainage route from the duodenum to the retroperitoneal space in "normal" specimens is described.

Identification of segments VI and VII of the liver based on the ramification patterns of the intrahepatic portal and hepatic veins

We describe the pattern of intrahepatic vessel ramification in the right posterior hepatic sector in a population of 197 adults. Each specimen was dissected from its visceral (inferior) surface in order to demonstrate variations in the distribution of the portal vein branches to the hepatic segments of the right lobe, especially to segments VI (S6) and VII (S7) as described by Couinaud. We also examine whether three hepatic veins, i.e., the right hepatic vein (RHV), middle hepatic vein (MHV), and the short hepatic vein (SHV), aid the identification of segmental portal branches in the lower posterior sector. Four major patterns of branching of the posterior sectorial trunk of the portal vein system are described. In group A (32.0%) a single posterior trunk formed an arch-like pattern sending multiple branches to S6 and S7 (P6 and P7). We named the multiple branches to the apparent S6 the inferoposterior portal branches. It was difficult to identify which of these branches were equivalent to P6. In group B (27.9%), the posterior sectorial trunk bifurcated to form P6 and P7. In most of the specimens in this group, therefore, we were able clearly to identify both S6 and S7 based on the portal vein system. In group C (6.6%), the trunk trifurcated to form P6, P7, and an intermediate branch, which supplied both segments or a gray zone between them. Group D (33.5%) included variations of the anterior segmental branches, and in specimens of this group, the anteromedial border of the sector was difficult to identify. Notably, the three-dimensional interdigitating topographical relationship of the hepatic veins and the portal branches was not evident in the lower posterior sector, since tributaries of the RHV and the portal branches followed similar courses and paralleled each other in the region and since the territory of the SHV was usually restricted to the superficial parenchyma near the inferior surface. In group A, tributaries of the RHV/SHV (>3 mm in diameter) passed between the inferoposterior portal branches in only 22.2%/14.3% of the specimens. Thus the hepatic veins often did not reveal which of the multiple inferoposterior branches was P6. Moreover, in the subset of Group B in which the segments were identified based on the portal vein ramification, tributaries of the RHV/SHV (>3 mm in diameter) showed the intersegmental interdigitating arrangement in only 32.0%/6.0% of the specimens. In addition, a thick tributary of the MHV, sometimes arising from S6, did not run along, but penetrated the S5/S6 border plane from the lateral to the medial side. Therefore, the three hepatic veins (RHV, SHV, MHV) often did not aid the identification of the liver segments in the region. Consequently, the less than ideal combinations of irregular configurations of the portal and hepatic venous systems suggest that the right posterior segments cannot be conclusively identified anatomically in 30-40% of cases. Other means of identification, such as the conventional proportional manner (the upper and lower halves of the posterior sector roughly correspond to S6 and S7) may be required.

Critical role of sulfenic acid formation of thiols in the inactivation of glyceraldehyde-3-phosphate dehydrogenase by nitric oxide

The relationship between possible modifications of the thiol groups of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by nitric oxide (NO) and modified enzyme activity was examined. There are 16 free thiols, including 4 active site thiols, in a tetramer of GAPDH molecule. NO donors, sodium nitroprusside (SNP), and S-nitroso-N-acetyl-DL-penicillamine (SNAP) decreased the number of free thiols with a concomitant inhibition of GAPDH activity in a concentration- and time-dependent manner. After treatment for 30 min, free thiols were maximally decreased to 8-10 per GAPDH tetramer and enzyme activity was also inhibited to 5-10% of control activity. In the presence of 30 mM dithiothreitol (DTT), these effects were completely blocked. Since similar results were obtained in the case of hydrogen peroxide (H2O2) treatment, which is known to oxidize the thiols, these effects of nitric oxide donors were probably due to modification of thiol groups present in a GAPDH molecule. On the other hand, DTT posttreatment after the treatment of GAPDH with SNP, SNAP, or H2O2 did not completely restore the modified thiols and the inhibited enzyme activity. DTT posttreatment after the 30-min-treatment with these agents restored free thiols to 14 in all treatments. In the case of SNAP treatment, all 4 active sites were restored and enzyme activity reached more than 80% of the control activity, but in two other cases one active site remained modified and enzyme activity was restored to about only 20%. Therefore, all 4 free thiols in the active site seem to be very important for full enzyme activity. DTT posttreatment in the presence of sodium arsenite, which is known to reduce sulfenic acid to thiol, almost completely restored both thiol groups and enzyme activity. These findings suggest that nitric oxide inhibits GAPDH activity by modifications of the thiols which are essential for this activity, and that the modification includes formation of sulfenic acid, which is not restored by DTT. S-nitrosylation, which is one type of thiol modification by NO, occurred when GAPDH was treated with SNAP but not SNP. Analysis of thiol modification showed that SNAP preferentially nitrosylated the active site thiols, the nitrosylation of which fully disappeared by DTT posttreatment. It seems that SNAP nitrosylates the active site thiols of GAPDH to prevent these thiols from oxidizing to sulfenic acid.

Mediators of nonadrenergic, noncholinergic relaxation in longitudinal muscle of the intestine of ICR mice

Mediators of nonadrenergic, noncholinergic (NANC) relaxation in longitudinal muscle of several regions of ICR mouse intestine were studied. An inhibitor of synthesis of nitric oxide, N(G)-nitro-L-arginine (L-NOARG) at 10 microM significantly inhibited NANC relaxations induced by electrical field stimulation (EFS) in the jejunum, ileum, and the proximal and distal colon. Especially in the ileum extent of the inhibition was more than 80%. An antagonist of vasoactive intestinal peptide (VIP) receptors, VIP(10-28) at 3 microM partially inhibited the EFS induced relaxations in the jejunum and proximal colon, but very slightly in the distal colon and had no effect in the ileum. An antagonist of pituitary adenylate cyclase activating peptide (PACAP) receptor, PACAP(6-38) at 3 microM partially inhibited the EFS-induced relaxations in the proximal and distal colon, but not in the jejunum and ileum. Totals of the percentages of relaxant components mediated by nitric oxide, VIP and PACAP in every region are roughly equal to a hundred percent. In another series of experiments, EFS-induced relaxations were almost completely inhibited by the treatment of the segments with L-NOARG and VIP(10-28) in the jejunum, with L-NOARG, VIP(10-28) and PACAP(6-38) in the proximal colon, and with L NOARG and PACAP(6-38) in the distal colon. The present results suggest that nitric oxide solely mediates the relaxation of longitudinal muscle of the ileum of ICR mice, whereas nitric oxide and VIP co-mediate it in the jejunum, nitric oxide, VIP and PACAP in the proximal colon, and nitric oxide and PACAP in the distal colon.

Configuration of hepatic veins in the right surgical lobe of the human liver with special reference to their complementary territorial relationships: morphometric analysis of controlled specimens with clearly defined portal segmentation

The configurations of hepatic veins, particularly the complementary territorial relationships between the veins, in the right surgical lobes of 156 human livers, the segments of which were identified clearly according to the portal ramification, were studied. In order to assess the functional roles of the vessels, we compared the diameter values of the vessels in the upper region of the lobe under the assumption that this parameter corresponds very closely to the actual blood flow volume through the vessel. The right hepatic vein (RHV) sometimes (17%) developed poorly and drained neither segment V (S5) nor VI (S6); instead, the inferomedial part of the S6 was often (26%) drained by the middle hepatic vein (MHV). However, most thick short hepatic veins (SHVs) did not drain S6 specifically instead of a poorly-developed RHV, but usually drained both S6 and segment VII (S7), irrespective of the configurations of other veins. Sometimes (8%), the RHV, rather than the MHV, drained a large part of S5. Overall, in the lower region of the lobe, the RHV, SHV and MHV showed complementary venous drainage relationships. Furthermore, the RHV usually (75%) ran not between S5 and S6 but through S6, corresponding to its usual territory, and could not be regarded as the intersectorial landmark in the lower region. Although various names have been given to the thick venous tributaries in the upper region of the right lobe, we systematically classified these tributaries into 5 types of "right superior radicles" (RSR), according to their topographical relationships with the right superior portal branches (P7 and P8), RHV, MHV, SHVs and their tributaries. When just thick RSRs were considered, the 5 types (anterior, posterior, lateral, medial and intersegmental) were observed in 90%, 88%, 89%, 38% and 34%, respectively. Notably, all but the intersegmntal RSRs almost always corresponded to a specific segmental territory (S7 or segment VIII (S8) and had specific terminals (at the RHV or MHV), suggesting that these 4 RSRs were proper segmental or intrasegmental veins, whereas, the 5th type showed a different configuration, i.e., an intersegmental vein that drained both S7 and S8, ran along and above the RHV and merged with it. Our morphometric examination of the upper region revealed that the sizes of P7 and P8 increased or decreased simultaneously, and suggested that the RSRs played limited roles in venous return. Rather than the RSRs, the SHVs appeared to drain the overflow in excess of the venous return capacity of the RSRs. Despite their limitations and possible complementary relationships with some veins, however, all the superior veins tended to developed evenly well or poorly. Overall, the venous return did not seem to converge into a single particular vein, but was carried away by multiple superior veins: the RHV, MHV, SHVs, and 5 RSRs.

Surgical treatment for recurrent tumors of primary malignant melanoma of the esophagus: a case report and review of the literature

The purpose of this communication is to present a case of resection performed for local recurrent tumors of primary malignant melanoma of the esophagus (PMME) and to review the relevant literature. The patient was a 54 year-old man who had received an intraabdominal esophagectomy with a total gastrectomy for primary malignant melanoma of the abdominal esophagus in another hospital, in November 1995. After the initial operation, he was treated as an outpatient. In August 1997, computed tomography and ultrasonography revealed recurrent tumors in the dorsal pancreatic lymph node and in the right adrenal gland. The recurrent tumor of the dorsal pancreas directly invaded the dorsal pancreas parenchyma and occluded the superior mesenteric vein and splenic vein, and the other metastatic tumor in the right adrenal gland existed in the absence of circumference invasion. Metastases of the PMME were confirmed in the dorsal pancreas, the superior mesenteric vein, splenic vein, and right adrenal gland, and were removed by a total pancreatectomy on October 7, 1997. By immunohistochemical staining, we found that the focal areas expressed S-100 protein and HMB-45 antibody. Currently (February 1998), the patient is alive and disease-free. PMME is an extremely rare tumor with a poor prognosis for survival. Only 2 cases of removal of recurrent tumors, including the present case, have been reported. The treatment of choice is surgical resection, even in cases of recurrence, because radiotherapy and/or chemotherapy have not been proven to be beneficial; however, they may play a palliative role if surgery is not possible.

Tyrosine kinase involvement in apamin-sensitive inhibitory responses of rat distal colon

1. It has been suggested that pituitary adenylate cyclase activating peptide (PACAP) may be involved in the non-adrenergic, non-cholinergic (NANC) inhibitory response of longitudinal muscle of rat distal colon. In this study, we have investigated the intracellular mechanism of PACAP-induced relaxation in this muscle. 2. PACAP induced an apamin-sensitive relaxation of the longitudinal muscle. The tyrosine kinase inhibitors genistein at 10 microM and tyrphostin 25 at 30 microM, but not the cyclic AMP-dependent protein kinase inhibitor Rp-8-bromoadenosine-3',5'-cyclic monophosphorothioate at 30 microM significantly inhibited the PACAP-induced relaxation to 60% and 25% of control values, respectively. PACAP did not increase the cyclic AMP content of the muscle. 3. Tyrphostin 25 at 10 microM significantly inhibited the relaxation of longitudinal muscle induced by electrical field stimulation (EFS), to 50% of control values. Apamin at 1 microM, an antagonist of small conductance Ca2+-activated K+ channels, also inhibited the relaxation, to 42 % of control values. The inhibitory effects of tyrphostin 25 and apamin were not additive (44 % of control values). 4. PACAP induced an apamin-sensitive, slow hyperpolarization of the cell membrane of the muscle. Tyrphostin 25 at 3 microM inhibited this PACAP-induced hyperpolarization. Tyrphostin 25 at 10 microM and genistein at 10 microM inhibited the apamin-sensitive inhibitory junction potentials induced by a single pulse of EFS. 5. The PACAP-induced relaxation of longitudinal muscle occurred with a concomitant decrease in intracellular Ca2+ levels ([Ca2+]i). Tyrphostin 25 at 10 microM and apamin at 1 microM abolished these PACAP-induced responses. 6. From these findings it is suggested that the activation of tyrosine kinase is involved in PACAP-induced relaxation of longitudinal muscle from rat distal colon, 'upstream of' the activation of apamin-sensitive K+ channels.