Significance of intracellular cations and calcium-regulating hormones on salt sensitivity in patients with essential hypertension

Although the existence of salt sensitivity in essential hypertensives has been well known, the precise mechanism(s) has not yet been elucidated. The aim of this study was to clarify the relation between the responses in blood pressure, extra- and intracellular cations and calcium-regulating hormones to oral NaCl loading in essential hypertensives. After oral NaCl loading, mean blood pressure, urinary excretions of calcium and magnesium, and PLT[Ca2+]i were significantly increased. [Ca2+]o and E[Mg]i were decreased. The changes (delta) in mean blood pressure by NaCl loading positively correlated with delta PLT[Ca2+]i and delta PTH, and negatively with delta[Ca2+]o and delta E[Mg]i. Delta PLT[Ca2+]i positively correlated with delta PTH and negatively with delta[Ca2+]o and delta E[Mg]i. From these results, the blood pressure response to oral NaCl loading is associated with the alternation of [Ca2+]i metabolism in which the changes in magnesium metabolism and calcium-regulating hormones may be involved.

Dexamethasone inhibits invasiveness of a human pancreatic cancer cell line

Recent studies have shown that dexamethasone inhibits gelatinases. We investigated the effect of dexamethasone on the invasiveness of a human pancreatic cancer cell line. Tumor cells were treated with dexamethasone at various concentrations for 24 h. Cells were examined in an invasion assay. The expression and activity of MMP-9 in culture media were quantitated by Western blotting and gelatin zymogram. The invasiveness of cancer cells and expression of MMP-9 were decreased by dexamethasone in a dose-dependent manner. Dexamethasone may be a useful therapeutic agent in the treatment of pancreatic cancer.

Alterations of the apc gene in carcinoma cell-lines and precancerous lesions of the stomach

Somatic mutations of the APC gene in eight cancer cell lines, twelve adenomas and sixteen intestinal metaplasias of the stomach were examined. The expression of the APC mRNA and protein in eight cancer cell lines was also investigated. PCR-SSCP analysis detected mutations of the APC gene in 25% (2 out of 8) of cancer cell lines, 42% (5 out of 12) of gastric adenomas, 6% (1 out of 16) of intestinal metaplasia mucosae. Direct sequencing analysis confirmed nonsense mutations in one cancer cell line, one adenoma and one intestinal metaplasia mucosa resulted in truncation of the product, frameshift mutations in one adenoma and silent mutations in one cancer cell line and three adenomas. In addition, the KATO-III cell line, which was established from signet ring cell carcinoma, expressed very low level of APC mRNA and its APC protein could not be detected. On the other hand, the expression level of variant APC mRNA transcript which lacks exon 7 was relatively high in KATO-III. It is supposed that the variant APC mRNA transcript might contribute to the inactivation of the APC gene. These data overall provide strong evidence that changes in the APC gene play an important role in the early event of stomach carcinogenesis, especially in intestinal type gastric cancer.

Single carcinoma cells at the deepest invasive portion correlate with metastatic potential of advanced colorectal carcinoma

The clinical significance of detecting single carcinoma cells (SC) at the deepest invasive portion of a tumor in terms of metastatic potential and prognosis was examined in 57 patients with surgically resected advanced colorectal carcinoma. SC were detected using an immunohistochemical stain for cytokeratin in these sections. The deepest invasive portions of tumors were subclassified by histology into three grades as follows: well-differentiated (W), moderately-well differentiated (Mw; a type that more closely resembles the W tumor), and moderately-poorly differentiated (Mp; more closely resembling poorly differentiated tumor). SC detection was defined positive if more than three single cancer cells with clear cytoplasmic expression of cytokeratin was seen distinct from carcinoma glands and tumor sheets in mid-power (x100) field. SC were detected in 51 (89%) of the 57 carcinomas. There were 5 W or Mw (W/Mw) tumors without SC, 34 W/Mw tumors with SC, 1 Mp tumor without SC, and 17 Mp tumors with SC. W/Mw tumors with SC had a significantly higher (p<0.01) incidence of lymph node metastasis than W/Mw tumors without SC. There was no lesion with lymph node or liver metastasis of W/Mw tumors without SC. SC detection, when combined with histologic subclassification at the deepest invasive portion of a tumor, correlated with prognosis. These results indicate that a combination of the tumor histologic subclassification and SC detection at the deepest invasive portion is a useful predictor of metastatic potential and prognosis in advanced colorectal carcinoma.

In patients with ulcerative colitis, adsorptive depletion of granulocytes and monocytes impacts mucosal level of neutrophils and clinically is most effective in steroid naïve patients

BACKGROUND

The aetiology of ulcerative colitis is inadequately understood, and drug therapy has been empirical rather than based on sound understanding of disease aetiology. This has been a major factor for refractoriness and adverse drug effects as additional complications. However, ulcerative colitis by its very nature is exacerbated and perpetuated by inflammatory cytokines, which are released by peripheral granulocytes and monocytes as well. Additionally, active ulcerative colitis is often associated with elevated peripheral granulocytes and monocytes with activation behaviour and are found in vast numbers within the colonic mucosa. Hence, from the clinicopathologic viewpoint, granulocytes and monocytes are appropriate targets for therapy in ulcerative colitis. Based on this thinking, an Adacolumn has been developed for depleting excess granulocytes and monocytes by adsorption.

METHODS

By colonoscopy, biopsy and histology, we investigated the impact of granulocyte and monocyte adsorption (GMA) on the mucosal level of granulocytes and monocytes in patients with active ulcerative colitis. Forty-five patients (26 steroid naïve and 19 steroid-dependent), mean age 44.7 yr, were included. Twenty patients had total colitis and 25 had left-sided colitis. Each patient was given up to 11 GMA sessions over 12 weeks. No patient received additional medications within 4 weeks (steroid) to 8 weeks (other immunosuppressants) prior to entry or during the GMA course. Colonoscopy together with biopsy was done at entry and within 2 weeks after the last GMA session.

RESULTS

At entry, the mean clinical activity index was 12.6; range 10-16. A total of 400 colonic biopsies were examined, which revealed massive infiltration of the colonic mucosa by granulocytes, and GMA was associated with striking reduction of granulocytes in the mucosa. At week 12, 33 of 45 patients (73.3%, P<0.01) had achieved clinical remission (the mean clinical activity index <or= 4). Colonoscopy revealed that most non-responders had deep colonic ulcers and extensive loss of the mucosal tissue. The response rate in steroid naïve subgroup was 22 of 26 patients (84.6%, P<0.005) and in steroid-dependent was 11 of 19 (57.9%, P<0.05 and P=0.02154 for steroid naïve vs. steroid-dependent). Patients who achieved remission could continue with their salicylates. On average, remission was sustained for 7.8 months in all 33 responders.

CONCLUSIONS

This is the first report showing a striking difference in clinical response to GMA between steroid naïve and steroid-dependent patients. Further, patients with deep colonic ulcers together with extensive loss of the mucosal tissue are not like to respond to GMA.

Preoperative diagnosis of intraductal papillary-mucinous tumors of the pancreas with attention to telomerase activity

BACKGROUND

It has been reported that, in patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas, it is difficult to distinguish adenoma from carcinoma preoperatively. Recently, it has also been reported that telomerase activity was detected in many patients with carcinoma. In this report, the authors used the method of telomerase repeat amplification protocol (TRAP) assay on pancreatic juice retrieved by endoscopic retrograde pancreatic juice aspiration (ERP aspiration).

METHODS

Pancreatic juice was collected from 28 patients (13 with intraductal carcinoma and 15 with adenoma) using ERP aspiration at either Hiroshima University Hospital or its affiliated hospitals. Two samples of pancreatic juice were collected from each patient. Each sample was examined by cytology for Papanicolaou staining and TRAP assay.

RESULTS

Four of 13 IPMT patients (31%) with intraductal carcinoma were diagnosed accurately by cytology. Seven of nine patients who were classified with benign tumors by cytologic assessment had tumors that expressed telomerase activity. Overall, 11 of 13 IPMT patients (85%) with intraductal carcinoma were diagnosed correctly by cytology associated with telomerase activity. All of the IPMT patients with adenoma were classified with benign tumors by cytologic assessment, and telomerase activity was not expressed.

CONCLUSIONS

In this study, the authors found that telomerase activity was expressed with a comparatively high probability in intraductal carcinoma. These results suggest that telomerase activity in pancreatic juices may be used as an adjunct to cytologic diagnosis and may aid further in distinguishing between benign IPMT and malignant IPMT of the pancreas preoperatively.

Phospholipid alterations in hepatocyte membranes and transporter protein changes in cholestatic rat model

Biliary components are transported by hepatic adenosine triphosphate-binding cassette (ABC) transporters that are located in canalicular membranes. Physiological transporter function is related to membrane fluidity, which is modulated by the phospholipid composition of the lipid bilayer. We hypothesized that cholestasis may alter transporter function by modifying phospholipid species to protect the cell from cholestatic damage. Therefore, we examined the expression of ABC transport proteins and their mRNA levels in canalicular membrane vesicles isolated from rat liver 6 hr or three days after bile duct ligation. Membrane lipid composition and membrane fluidity of both sinusoidal and canalicular membrane vesicles were also examined. By 6 hr after bile duct ligation, we found a clear increase of mdr2 and bsep mRNA. These changes were associated with an increase of mdr-Pgp and with a clear decrease of mrp2 protein, and small decrease of bsep protein. In addition, mdrlb mRNA showed a strong increase by three days after bile duct ligation. Canalicular membrane fluidity decreased in a marked time-dependent manner, whereas sinusoidal membranes showed biphasic changes: increased fluidity at 6 hr and a decrease at three days. These changes were closely related to the changes of membrane lipid constitution; the saturated/unsaturated fatty acid ratio increased for phosphatidylcholine in canalicular membrane and the reverse occurred in sinusoidal membrane, and those for sphingomyelin showed the opposite pattern. We conclude that cholestasis causes modulation of ABC transporters as well as that of the lipid constitution in lipid bilayer. These may confer cytoprotective resistance to hepatocytes against cholestatic stress.

Magnesium causes nitric oxide independent coronary artery vasodilation in humans

OBJECTIVE

To determine how magnesium affects human coronary arteries and whether endothelium derived nitric oxide (EDNO) is involved in the coronary arterial response to magnesium.

DESIGN

Quantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on magnesium induced dilation of the epicardial and resistance coronary arteries.

SETTING

Hiroshima University Hospital a tertiary cardiology centre.

PATIENTS

17 patients with angiographically normal coronary arteries.

INTERVENTIONS

Magnesium sulfate (MgSO(4)) (0.02 mmol/min and 0.2 mmol/min) was infused for two minutes into the left coronary ostium before and after intracoronary infusion of L-NMMA.

MAIN OUTCOME MEASURES

Diameter of the proximal and distal segments of the epicardial coronary arteries and coronary blood flow.

RESULTS

At a dose of 0.02 mmol/min, MgSO(4) did not affect the coronary arteries. At a dose of 0.2 mmol/min, MgSO(4) caused coronary artery dilation (mean (SEM) proximal diameter 3.00 (0.09) to 3.11 (0.09) mm; distal 1.64 (0.06) to 1.77 (0.07) mm) and increased coronary blood flow (79.3 (7.5) to 101.4 (9.9) ml/min, p < 0.001 v baseline for all). MgSO(4) increased the changes in these parameters after the infusion of L-NMMA (p < 0.001 v baseline).

CONCLUSIONS

Magnesium dilates both the epicardial and resistance coronary arteries in humans. Furthermore, the coronary arterial response to magnesium is dose dependent and independent of EDNO.

Magnesium causes nitric oxide independent coronary artery vasodilation in humans

OBJECTIVE

To determine how magnesium affects human coronary arteries and whether endothelium derived nitric oxide (EDNO) is involved in the coronary arterial response to magnesium.

DESIGN

Quantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthase inhibitorNG-monomethyl-L-arginine (L-NMMA) on magnesium induced dilation of the epicardial and resistance coronary arteries.

SETTING

Hiroshima University Hospital a tertiary cardiology centre.

PATIENTS

17 patients with angiographically normal coronary arteries.

INTERVENTIONS

Magnesium sulfate (MgSO4) (0.02 mmol/min and 0.2 mmol/min) was infused for two minutes into the left coronary ostium before and after intracoronary infusion of L-NMMA.

MAIN OUTCOME MEASURES

Diameter of the proximal and distal segments of the epicardial coronary arteries and coronary blood flow.

RESULTS

At a dose of 0.02 mmol/min, MgSO4 did not affect the coronary arteries. At a dose of 0.2 mmol/min, MgSO4 caused coronary artery dilation (mean (SEM) proximal diameter 3.00 (0.09) to 3.11 (0.09) mm; distal 1.64 (0.06) to 1.77 (0.07) mm) and increased coronary blood flow (79.3 (7.5) to 101.4 (9.9) ml/min, p < 0.001 vbaseline for all). MgSO4 increased the changes in these parameters after the infusion of L-NMMA (p < 0.001v baseline).

CONCLUSIONS

Magnesium dilates both the epicardial and resistance coronary arteries in humans. Furthermore, the coronary arterial response to magnesium is dose dependent and independent of EDNO.

Long-term prognosis of patients undergoing transcatheter arterial chemoembolization for unresectable hepatocellular carcinoma: comparison of cisplatin lipiodol suspension and doxorubicin hydrochloride emulsion

PURPOSE

To evaluate long-term prognosis of transcatheter arterial chemoembolization (TACE) with use of cisplatin (CDDP) lipiodol (LPD) suspension (CDDP/LPD) compared with that with use of doxorubicin hydrochloride (ADM) LPD emulsion (ADM/LPD) in patients with unresectable hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

One hundred eight patients were treated with use of CDDP/LPD and 26 were treated with use of ADM/LPD. Survival rates and frequency of side effects and complications in the CDDP/LPD group were compared with those in the ADM/LPD group.

RESULTS

CDDP/LPD was given at a dose of 15-70 mg (mean dose, 41 mg), whereas ADM/LPD was given at a dose of 20-100 mg (mean dose, 57 mg) throughout the study period. The survival rates in the CDDP/LPD group were 81% at 1 year, 41% at 3 years, 19% at 5 years, and 13% at 7 years, whereas those in the ADM/LPD group were 67% at 1 year, 18% at 3 years, and 0% at 5 years. The CDDP/LPD group showed significantly better survival than the ADM/LPD group (P <.05). In the CDDP/LPD group, there was a significant prolongation of survival in patients with monofocal HCC (P <.05) and patients with HCC assessed as an almost complete LPD accumulation (P <.05). There were no significant differences in survival rates in the ADM/LPD group according to tumor size and number of tumors. Hepatic failure was observed in 8% of all procedures and was not different between the two therapeutic groups. Renal dysfunction was observed in 2% of all treatments involving CDDP/LPD, and it resolved spontaneously with appropriate medications.

CONCLUSIONS

TACE with use of low-dose CDDP was efficacious for unresectable HCC and had few complications. TACE with use of CDDP may contribute to prolongation of the life span of patients with HCC versus TACE with use of ADM.

Effects of angiotensin-(1-7) on forearm circulation in normotensive subjects and patients with essential hypertension

Previous animal studies have shown that angiotensin (Ang)-(1-7) is a biologically active component of the renin-angiotensin system, acting as a vasoactive agent, and may play a role in the blood pressure regulation. There is little information, however, on the effect of Ang-(1-7) on human circulation or the mechanism of its action. To investigate the effect of Ang-(1-7) on forearm circulation and to determine whether this effect is altered in patients with essential hypertension, we measured change in forearm blood flow using venous occlusion plethysmography in response to intra-arterial infusion of Ang-(1-7) (10(-10), 10(-9), and 10(-8) mol/min; for 5 minutes) in normotensive control subjects (n=8) and patients with essential hypertension (n=8). Infusion of Ang-(1-7) significantly increased the forearm blood flow response in a dose-dependent manner in both normotensive control subjects (28.7+/-9.7%, at 10(-8) mol/min; P<0.05) and hypertensive patients (31.8+/-15.2%, at 10(-8) mol/min; P<0.05). The vasodilatory effect of Ang-(1-7) was similar in the two groups. Intra-arterial infusion of N(G)-monomethyl-L-arginine, a nitric oxide synthesis inhibitor, did not alter the forearm blood flow response to Ang-(1-7) in either group. These findings suggest that Ang-(1-7) causes vasodilation in forearm circulation of normotensive subjects and patients with essential hypertension through a pathway that is independent of nitric oxide synthesis.

Vitamin D receptor gene polymorphism is associated with serum total and ionized calcium concentration

Restriction fragment length polymorphisms of the vitamin D receptor gene have recently been reported to be associated with changes in bone mineral density. Alterations in systemic calcium balance and Ca-regulating hormones such as 1,25(OH)2 vitamin D3 and parathyroid hormone have been demonstrated in essential hypertension. We investigated the relationship between polymorphisms of the vitamin D receptor gene and systemic Ca metabolism in patients with essential hypertension and in normotensives. We compared 147 subjects with essential hypertension and 100 normotensive control subjects. The genotype distribution and derived allele frequencies for the vitamin D receptor gene were similar in the two groups (genotype bb/Bb/BB and allele B/b: 60.1/32.6/7.2 and 0.24/0.76 in hypertensives vs. 56.0/36.0/8.0 and 0.26/0.74 in normotensive subjects). Serum concentrations of total Ca in the bb, Bb, and BB groups were, respectively, 4.5+/-0.3 vs. 4.5+/-0.4 vs. 4.4+/-0.5 mmol/l in normotensives and 4.6+/-0.3 vs. 4.6+/-0.4 vs. 4.4+/-0.5 mmol/l in hypertensives. Ionized Ca levels were 1.17+/-0.04 vs. 1.16+/-0.04 vs. 1.15+/-0.04 mmol/l in normotensives and 1.16+/-0.04 vs. 1.16+/-0.04 vs. 1.14+/-0.05 mmol/l in hypertensives, respectively. These results indicate that the BB genotype of the vitamin D receptor gene is associated with lower serum Ca levels but is not a useful predictive marker for the development of essential hypertension in Japanese subjects.

Effects of omeprazole and pirenzepine on enterochromaffin-like cells and parietal cells in rat stomach

PURPOSE

The purpose of this study was to investigate the mechanism of the regulation of histamine synthesis in enterochromaffin-like cells, chemically and structurally, by treatment with omeprazole and pirenzepine.

METHODS

The ultrastructures of enterochromaffin-like cells and parietal cells were examined in rats treated with oral omeprazole (20 mg/kg) or intraperitoneal pirenzepine (1 mg/kg) administration. Serum gastrin concentrations, mRNA levels of H+-K+-ATPase and histidine decarboxylase, and the fundic concentrations of somatostatin and histamine were determined.

RESULTS

Pirenzepine treatment suppressed omeprazole-induced increases in serum gastrin levels and mRNA levels of H+-K+-ATPase and histidine decarboxylase. Pirenzepine also decreased omeprazole-induced increases of histamine concentration in fundic mucosa. Pirenzepine elevated somatostatin mRNA level, previously decreased by omeprazole treatment, in fundic mucosa. In the cytoplasm of enterochromaffin-like cells, omeprazole markedly reduced the numbers of vesicles and granules, but significantly increased their diameters, whereas pirenzepine treatment changed neither of these features. The densities and diameters of both vesicles and granules produced by treatment with omeprazole and pirenzepine were between those produced by treatment with omeprazole alone and pirenzepine alone.

CONCLUSIONS

Omeprazole-induced hypergastrinemia and pirenzepine-induced somatostatin synthesis play important roles not only in histamine synthesis but also in ultrastructural changes in enterochromaffin-like cells.

Modifying hepatic phospholipid synthesis associates with biliary phospholipid secretion rate in a transporter-independent manner in rats: relation to canalicular membrane fluidity

Biliary phospholipid secretion is mediated by a multidrug resistance gene product, and its molecular subselection occurs at the site of secretion to modulates bile metastability. The aim of this study was to determine the effect of modifying hepatic phospholipid synthesis on canalicular phospholipid transporter expression and membrane fluidity. Bile-duct cannulation was performed in male Sprague-Dawley rats pretreated with or without intravenous infusion of dimethylethanolamine, an intermediate phospholipid metabolite along the pathway of phosphatidylcholine synthesis of phosphatidylethanolamine N-methylation (0.01 mg/min/100 g body wt) for 15 hr, followed by sodium taurocholate infusion (50 nmol/min/100 g body wt) with or without sulfobromophthalein (50 nmol/min/100 g body wt). Dimethylethanolamine enhanced biliary phospholipid secretion in association with a decrease in biliary phospholipid hydrophobicity. Dimethylethanolamine also increased canalicular membrane fluidity defined by 1,6-diphenyl-1,3,5-hexatriene fluorescence depolarization, whereas the expression of multidrug resistance gene product and multidrug resistance associated protein was unchanged. In contrast, a disproportionate reduction of biliary phospholipid secretion caused by sulfobromophthalein (uncoupling) was enhanced by under the treatment with dimethylethanolamine. In conclusion, the increase in biliary phospholipid secretion and canalicular membrane fluidity without a drastic change of its canalicular transporter by dimethylethanolamine suggests that such a canalicular membrane fluidity facilitates the transporter activity and/or phospholipid molecular movement from the canalicular outer membrane into the bile. A more drastic reduction in phospholipid secretion under sulfobromophthalein-caused uncoupling indicates the possibility of a preferential distribution of relatively hydrophilic phosphatidylcholine molecules to bile salt micelles since sulfobromophthalein is known to reduce the micellar capacity to extract membrane lipids for biliary secretion.

Protective effect of ammonia against reflux esophagitis in rats

Although several recent studies have reported that curing Helicobacter pylori (H. pylori) may result in the development of reflux esophagitis (RE), the mechanisms leading to this complication are unknown. One by product of H. pylori infection is ammonia, which serves as an acid neutralizer. The aim of this study was to clarify whether ammonia, which is produced during H. pylori infection, has a protective effect on the esophagus. Eight-week-old male Sprague-Dawley rats were fasted for 24 hrs. Under anesthesia, both the pylorus and limiting ridge were simultaneously ligated. One hour postligation, 0.3 ml of saline or ammonia at various concentrations was administered intragastrically by gastric intubation. Three hours after ligation, the animals were killed, the esophagus and stomach were removed, and the length of esophageal hemorrhagic erosions was measured. The incidence of RE was 100% (7/7) in the control group, 71% (5/7) in the low-ammonia group, 29% (2/7) in the middle-ammonia group, and 14% (1/7) in the high-ammonia group. The severity of lesions decreased in correspondence to increases in ammonia concentration. The development of RE was significantly inhibited by ammonia in a dose-dependent manner. This study indicates that ammonia protects against development of RE. A decreased amount of ammonia in the stomach might be related to the development of RE after H. pylori eradication therapy.

Clinical significance of human erythrocyte glucose transporter 1 expression at the deepest invasive site of advanced colorectal carcinoma

OBJECTIVE

Malignant cells exhibit increased glucose uptake and utilization in vitro and in vivo. This process is thought to be mediated by the glucose transporter (Glut) family. The aim of this study was to elucidate the clinical significance of Glut1 expression at the site of deepest invasion as a predictor of the invasive/metastatic potential and prognosis of advanced colorectal carcinoma (CRC).

METHODS

One hundred and fifty-two patients who had undergone surgical resection for advanced CRC were entered in this study. Histologic subclassifications at the deepest invasive site included well-differentiated (W), moderately to well-differentiated (Mw), moderately to poorly differentiated (Mp), poorly differentiated (Por) and mucinous (Muc) adenocarcinomas. Glut1 expression was examined immunohistochemically with a labeled streptavidin-biotin kit using anti-Glut1 polyclonal antibody MYM. As a marker of cell proliferation, Ki-67 expression was also examined. All immunoreactivity was analyzed at the deepest invasive site, central portion and superficial part. The immunohistochemical expression of Glut1 was defined as positive if distinct staining of the membrane or cytoplasm was observed in at least 30% of tumor cells.

RESULTS

Glut1 expression was detected in 56 of 152 lesions (36.8%) at the deepest invasive site. The incidence of Glut1 expression at the deepest invasive site correlated significantly with histologic grade (W/Mw grade, 28% vs. Mp/Por/Muc grade, 48%), depth of invasion (invasion of muscularis propria/invasion of subserosa or subadventitia, 29% vs. invasion of serosa or adventitia/invasion of adjacent structures, 52%), lymphatic invasion (absence of lymphatic invasion, 19% vs. presence of lymphatic invasion, 40%), lymph node metastasis (absence of lymph node metastasis, 25% vs. presence of lymph node metastasis, 41%) and Duke's stage (Duke's <D, 32% vs. Duke's D, 51%). In the central portion and superficial part, there were no significant differences between Glut1, Ki-67 expression and clinicopathological findings. Glut1 expression at the deepest invasive site correlated significantly with the Ki-67 labeling index. In cases of curative surgery, patients with Glut1-positive lesions at the deepest invasive site showed a significantly poorer prognosis than those with Glut1-negative lesions. Multivariate analysis with logistic regression for 5-year survival in patients who had undergone curative surgery showed that lymph node metastasis and Glut1 expression were significant risk factors.

CONCLUSION

These results indicate that Glut1 expression at the deepest site of tumor invasion can be a useful predictor of a high malignant potential and poor prognosis in advanced CRC.

Coronary atherosclerosis and oxidative stress as reflected by autoantibodies against oxidized low-density lipoprotein and oxysterols

Clinical studies and animal experiments have demonstrated that oxidized low-density lipoprotein (oxLDL) and oxysterols play important roles in atherogenesis. OxLDL is immunogenic, and autoantibodies (Ab) against oxLDL are detectable in serum. We investigated the relevance of oxysterols and Ab against-oxLDL to coronary artery disease (CAD) in 183 patients undergoing coronary angiography. Patient groups included angiographically normal subjects (< 75% stenosis), others with spasm (> 75% narrowing in response to acetylcholine), and some others with fixed stenosis (> 75%). The group with stenosis was subdivided into patients with stable and unstable angina. Serum concentrations of autoantibodies and 25-, 27-, and 7-beta-hydroxycholesterols were significantly higher in the stenotic group than in the normal group (P < 0.01, P < 0.05, P < 0.05, and P < 0.05, respectively). Antibodies, but not oxysterol concentrations, were significantly greater in subjects with unstable than with stable angina (P < 0.01). We conclude that anti-oxLDL antibody and oxysterol concentrations are associated with coronary artery stenosis, and that oxidative stress may be greatly increased in unstable angina.

Three-dimensional portography using multislice helical CT is clinically useful for management of gastric fundic varices

OBJECTIVE

This study seeks to evaluate three-dimensional (3D) helical CT portography as a tool for examining patients with gastric fundic varices.

SUBJECTS AND METHODS

We compared 3D helical CT portography and conventional angiographic portography in 30 consecutive patients with gastric fundic varices. We assessed whether 3D helical CT portography is useful in selecting patients and in evaluating the results of balloon-occluded retrograde transvenous obliteration.

RESULTS

Three-dimensional helical CT portography simultaneously depicted second or third branches of the intrahepatic portal vein and provided images of entire portosystemic collaterals. On 3D helical CT portography, gastric fundic varices were seen in 30 patients (100%), left gastric veins in 19 (63%), posterior gastric veins or short gastric veins in 28 (93%), gastrorenal shunts in 27 (90%), paraumbilical veins in three (10%), and inferior phrenic veins in two patients (7%). Findings of 3D helical CT portography and conventional angiographic portography were in close agreement. However, in four patients, posterior gastric veins or short gastric veins were not seen on conventional angiographic portography images of the spleen, but they were clearly revealed on 3D helical CT portography. Treatment was successful in all patients except one. Three-dimensional helical CT portography could easily evaluate therapeutic results.

CONCLUSION

Three-dimensional helical CT portography proved so effective that it can be considered a less invasive alternative than conventional angiographic portography in assessing portosystemic collaterals. CT portography is useful in selecting candidates from patients with gastric fundic varices for retrograde transvenous obliteration and also in evaluating therapeutic results.

Carcinogenesis of malignant lesions of the gall bladder. The impact of chronic inflammation and gallstones

Gallbladder carcinoma is an uncommon but highly malignant tumor with a poor 5-year survival rate. The presence of gallstones is a well-established risk factor for gallbladder carcinoma, and the risk seems to correlate with stone size. Metaplastic changes of the gallbladder epithelium present in chronic cholecystitis may be a premalignant lesion. Solitary polyps with a size of greater than 1 cm are recognized as a predisposing factor for gallbladder carcinoma when their characteristics are echopenic, sessile, and high cell density. Endoscopic ultrasound is the most useful technique to detect the early changes of malignancy in polyps. Anomalous junction of pancreaticobiliary ducts (AJPBD) without a choledochal cyst and porcelain gallbladder is an additional risk factor for gallbladder malignancy. At the molecular level, it has been proposed that chronic inflammation of the gallbladder may lead to the loss of p53 gene heterozygosity and excessive expression of p53 protein. Furthermore, a proposed mechanism underlying the high risk of gallbladder carcinoma in patients with AJPBD is that chronic reflux of pancreatic juice causes intestinal metaplasia, hyperplasia, and dysplasia with the mutation of p53 and K-ras. In contrast, the causal relationship between porcelain gallbladder and malignancy is yet to be established. In this article, recognition of risk factors for gallbladder carcinoma was summarized with special attention to gallstones and chronic inflammation.

Peptic ulcer recurrence during maintenance therapy with H2-receptor antagonist following first-line therapy with proton pump inhibitor

We investigated the peptic ulcer recurrence rates during maintenance therapy with H2-receptor antagonists (H2RAs) following first-line therapy with a proton pump inhibitor (PPI). Patients with gastric ulcer (GU) or duodenal ulcer (DU) were enrolled in this study; 583 eligible patients (GU, 325; DU, 258) were administered lansoprazole (30 mg/day for 8 weeks for GU, and the same dosage for 6 weeks for DU) as first-line therapy, and a half dose of H2RA as maintenance therapy for 12 months. Endoscopic photographs were taken before administration and after 8 (GU) and 6 (DU) weeks of lansoprazole administration. Ulcer stage was evaluated using the classification of Sakita and Miwa. Endoscopic examinations were performed 6 months or 12 months after the start of maintenance therapy or when a recurrence was suspected because of the appearance of subjective symptoms. The healing rates for GU and DU patients after completion of lansoprazole therapy were 79% in both groups, while the S2-stage healing rates were 18% and 31%, respectively. At 1 year after the start of maintenance therapy, the recurrence rates were 25% for GU and 39% for DU patients. In DU patients, the recurrence rates from S1-stage and S2-stage were 49% and 20%, respectively (P = 0.004), but no significant difference was found between these rates in GU patients. The recurrence rates in H. pylori-positive patients before lansoprazole administration were 27% for GU and 43% for DU patients. We concluded that the maintenance therapy with a half-dose of H2RA following PPI therapy was insufficient to prevent recurrences of GU and DU.

Cyclosporin A reduces canalicular membrane fluidity and regulates transporter function in rats

Changes of the biliary canalicular membrane lipid content can affect membrane fluidity and biliary lipid secretion in rats. The immunosuppressant cyclosporin A is known to cause intrahepatic cholestasis. This study investigated whether cyclosporin A influenced canalicular membrane fluidity by altering membrane phospholipids or transporter expression. In male Sprague-Dawley rats, a bile-duct cannula was inserted to collect bile, and sodium taurocholate was infused (100 nmol/min per 100 g) for 60 min. During steady-state taurocholate infusion, cyclosporin A (20 mg/kg) or vehicle was injected intravenously and then bile was collected for 80 min. After killing the rats, canalicular membrane vesicles were prepared. Expression of canalicular membrane transporters was assessed by Western blotting and canalicular membrane vesicle fluidity was estimated by fluorescence polarization. Cyclosporin A reduced biliary lipid secretion along with a disproportionate reduction of lipids relative to bile acids. Cyclosporin A significantly decreased canalicular membrane fluidity along with an increase of the cholesterol/phospholipid molar ratio. Only expression of the transporter P-glycoprotein was increased by cyclosporin A. Because canalicular membrane transporter expression was largely unchanged by cyclosporin A despite a marked decrease of biliary lipid secretion, transporter activity may partly depend upon canalicular membrane fluidity.

B-cell monoclonality in Helicobacter pylori-associated chronic atrophic gastritis

B-cell monoclonality has been reported not only in gastric lymphoma, but also in 1.3-21% of Helicobacter pylori-associated chronic gastritis (Hp-CG) cases. The aim of this study was to determine the significance of B-cell monoclonality in Hp-CG. We examined 134 gastric biopsy specimens from 99 patients with Hp-CG. The density of Hp, polymorphonuclear neutrophil activity, chronic inflammation, glandular atrophy, and intestinal metaplasia (IM) were scored according to the updated Sydney System. B-cell monoclonality was analyzed for immunoglobulin heavy chain gene rearrangement using polymerase chain reaction amplification. B-cell monoclonality was detected in 6% of informative samples. B-cell monoclonality was found in 18% of the samples from Hp-CG patients with marked glandular atrophy but in none of the samples from Hp-CG patients with none to moderate glandular atrophy. Monoclonality was also detected in 20% of the samples from Hp-CG patients with marked IM, in 11% of the samples from Hp-CG patients with moderate IM, and in none of the samples from Hp-CG patients without IM. Therefore, B-cell monoclonality was significantly more frequent in Hp-CG patients with marked glandular atrophy than in Hp-CG patients with none to moderate atrophy. It was also more significantly frequent in Hp-CG patients with moderate or marked IM than in Hp-CG patients without IM (P < 0.05). Of 35 Hp-CG patients, 26 (74%) had identical B-cell populations in the antrum and the corpus, and all were polyclonal. The remaining nine (26%) Hp-CG patients had B-cell populations that differed in the antrum and the corpus. Four of the nine (44%) showed monoclonal B-cell populations in at least one gastric biopsy specimen. There were no patients with monoclonal B-cell populations in both the antrum and the corpus. These data suggest that glandular atrophy and IM in gastric biopsy specimens may be markers for gastric mucosa-associated lymphoid tissue (MALT) lymphoma-genesis and that multiple gastric biopsy specimens from both the antrum and the corpus may be needed to assess the risk of gastric MALT lymphoma.

Effect of the angiotensin-converting enzyme inhibitor imidapril on reactive hyperemia in patients with essential hypertension: relationship between treatment periods and resistance artery endothelial function

OBJECTIVES

The purpose of this study was to evaluate the effects of the angiotensin-converting enzyme (ACE) inhibitor imidapril and the calcium antagonist amlodipine on endothelial function before and after 2, 4, 8, 12, 24 and 48 weeks of treatment.

BACKGROUND

There are limited data on whether and how long endothelial function is improved after initiation of ACE inhibitor treatment and how the grade of endothelial function further progresses after improvement of endothelial dysfunction in patients with essential hypertension.

METHODS

The forearm blood flow (FBF) was measured in 25 patients with essential hypertension and in 25 normotensive subjects by using strain-gauge plethysmography during reactive hyperemia (RH) (280 mm Hg for 5 min) and after sublingual administration of nitroglycerin (NTG, 0.3 mg).

RESULTS

The FBF of patients with essential hypertension during RH was significantly less than that of normotensive subjects. The increase in FBF after sublingual NTG was similar in both groups. Both imidapril (n = 13) and amlodipine (n = 12) significantly reduced systolic blood pressure and diastolic after eight weeks of treatment from the pretreatment values. Forearm vascular resistance was significantly decreased after two weeks of treatment. Imidapril significantly augmented RH after 12 weeks of treatment from the pretreatment values (31.6 +/- 5.7 to 38.2 +/- 6.0 m/min per 100 ml tissue, p < 0.05), whereas amlodipine did not alter RH for each treatment period. The ability of imidapril to improve RH was maintained throughout the 48-week treatment period. There was no significant difference in RH at 12, 24 and 48 weeks. The increase in FBF after sublingual administration of NTG was similar in all treatment periods for the two groups. The infusion of NG-monomethyl-L-arginine, a nitric oxide (NO) synthase inhibitor, abolished the enhancement of RH in hypertensive patients treated with imidapril.

CONCLUSIONS

These findings suggest that the ACE inhibitor imidapril augments RH after 12 weeks of treatment in patients with essential hypertension and that this ACE inhibitor-induced augmentation of RH may be due to an increase in NO.

Duodenogastric reflux is associated with antral metaplastic gastritis

BACKGROUND

It has long been suspected that duodenogastric reflux plays a role in the pathogenesis of intestinal metaplasia (IM), although recent studies have demonstrated a close association between Helicobacter pylori infection and gastroduodenal diseases, including IM. The objective of this study was to investigate the relation among IM and duodenogastric reflux, H pylori infection, and smoking.

METHODS

Subjects with "marked" characteristics of IM, all with extensive prepyloric distribution at endoscopy that was confirmed histologically, were studied as an IM group (27 men, 26 women; mean age, 64 years). A control group was comprised by subjects without characteristics of IM (29 men, 28 women; mean age, 63 years). Fasting pH, total bile acid concentration, and ammonia concentration were measured in the gastric juice of all participants. Histologic examination endoscopic biopsy specimens were evaluated histologically. H pylori infection was determined by serum antibody and urease testing, and by histology. Serum gastrin and pepsinogen concentrations, and gastric emptying time were measured. Dietary, drinking, and smoking habits were recorded. Comparisons were made between groups and analyzed statistically.

RESULTS

The pH and total bile acid concentrations were significantly higher in the IM group than the control group (p < 0.01). No significant difference in H pylori infection was found between the IM and control group. Smoking was associated with IM (odds ratio [OR], 15.74; 95% CI, 3.96 to 62.50).

CONCLUSIONS

A high pH and total bile acid concentration and smoking were associated with "marked" IM, suggesting that these factors may play a role in the development of IM.

A noninvasive measurement of reactive hyperemia that can be used to assess resistance artery endothelial function in humans

We demonstrated that endothelial function in patients with essential hypertension is impaired by a decrease in nitric oxide production using both reactive hyperemia and acetylcholine infusion methods. This noninvasive method of evaluating reactive hyperemia is a useful alternative to intra-arterial infusions of vasoactive agents in the assessment of resistance vessels' endothelial function in forearm circulation.

Preoperative diagnosis of intraductal papillary-mucinous tumors of the pancreas with attention to telomerase activity

BACKGROUND

It has been reported that, in patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas, it is difficult to distinguish adenoma from carcinoma preoperatively. Recently, it has also been reported that telomerase activity was detected in many patients with carcinoma. In this report, the authors used the method of telomerase repeat amplification protocol (TRAP) assay on pancreatic juice retrieved by endoscopic retrograde pancreatic juice aspiration (ERP aspiration).

METHODS

Pancreatic juice was collected from 28 patients (13 with intraductal carcinoma and 15 with adenoma) using ERP aspiration at either Hiroshima University Hospital or its affiliated hospitals. Two samples of pancreatic juice were collected from each patient. Each sample was examined by cytology for Papanicolaou staining and TRAP assay.

RESULTS

Four of 13 IPMT patients (31%) with intraductal carcinoma were diagnosed accurately by cytology. Seven of nine patients who were classified with benign tumors by cytologic assessment had tumors that expressed telomerase activity. Overall, 11 of 13 IPMT patients (85%) with intraductal carcinoma were diagnosed correctly by cytology associated with telomerase activity. All of the IPMT patients with adenoma were classified with benign tumors by cytologic assessment, and telomerase activity was not expressed.

CONCLUSIONS

In this study, the authors found that telomerase activity was expressed with a comparatively high probability in intraductal carcinoma. These results suggest that telomerase activity in pancreatic juices may be used as an adjunct to cytologic diagnosis and may aid further in distinguishing between benign IPMT and malignant IPMT of the pancreas preoperatively.

Splanchnic-mesenteric capacitance bed in the postural tachycardia syndrome (POTS)

BACKGROUND

Gastroenterologic symptoms are common in the postural tachycardia syndrome (POTS), and postprandial worsening of orthostatic symptoms often occurs. We, therefore, investigated splanchnic-mesenteric vasoregulation in POTS.

SUBJECTS AND METHODS

Eleven patients with POTS (one man, 10 women, 29.4 +/- 7.7 (S.D.) years) and 10 controls (two men, eight women, 27.9 +/- 5.6 years) participated in this study. The protocol included 5 min of 70 degrees head-up tilt (HUT) before and after a liquid meal, as well as 1.5 min of hyperventilation. Blood pressure (BP), heart rate (HR), endtidal CO2, and cardiovascular indices derived from thoracic electrical bioimpedance were continuously monitored. Superior mesenteric artery (SMA) blood flow was measured by real time Doppler ultrasound and analyzed off-line. Cross-sectional area of SMA (SMA-area) and time-averaged velocity (SMA-TAV) were measured; SMA blood flow (SMA-BF) and vascular resistance (SMA-VR) were derived.

RESULTS

The following significant results were found: at supine rest, the POTS group had higher HR, BP, SMA-TAV and SMA-BF and a lower SMA-VR than the control group. HUT resulted in a reduction of pulse pressure, CO2 level, SMA-area, SMA-TAV and SMA-VF and increment of HR and SMA-VR in both groups. The POTS group underwent greater increment of HR and greater reduction of CO2 than controls. Hyperventilation induced increment of HR and cardiac index (CI) and reduction of SMA-VR in controls; no significant change occurred in POTS. The test meal induced increments of HR, CI, SMA-area, SMA-TAV and SMA-VF and reduction of SMA-VR in patients and controls for both supine rest and HUT.

CONCLUSION

The main novel observations of increased resting SMA-BF, SMA-TAV supine, and reduced SMA-VR when compared with controls support the notion that there is excessive splanchnic capacity (pooling) at rest in POTS.

Gallbladder dysfunction enhances physical density but not biochemical metastability of biliary vesicles

The gallbladder role in cholesterol gallstone pathogenesis occurs through modulation of bile cholesterol metastability. The present study characterized the effects of concentrating bile on cholesterol crystallization through vesicle transformation, crystal habits, and potentiation of effector substances. Supersaturated model biles with total lipid concentrations of 12, 9, 6, and 3 g/dl were prepared with identical molar ratios (taurocholate-egg yolk phosphatidylcholine-cholesterol: 71:18:11). Bile metastability was assessed spectrophotometrically, and morphology of vesicle and crystal was sequentially scanned by video-enhanced differential contrast microscopy. The effects of replacing 30% of egg yolk phosphatidylcholine with soy bean phosphatidylcholine, 30% of taurocholate with taurodeoxycholate or tauroursodeoxycholate, and addition of concanavalin A-binding glycoprotein on each model bile were examined. By lowering total lipid concentration, cholesterol crystallization was retarded with less fusion and aggregation of vesicles. The effects of substances promoting cholesterol crystallization were enhanced with lesser bile. By replacing 30% of taurocholate with tauroursodeoxycholate, cholesterol crystallization was markedly inhibited in all concentrations, forming stable liquid-crystals. Impaired water absorption by the gallbladder may stabilize vesicles and inhibit rapid cholesterol crystallization, but the potential of cholesterol crystallization effector substances must be modified to alter bile cholesterol metastability.

The preventive effect of magnesium on coronary spasm in patients with vasospastic angina

STUDY OBJECTIVES

Previous studies have reported that magnesium (Mg) deficiency is associated with coronary spasm. However, little is known about the preventive effect of Mg on coronary spasm. The present study investigated whether Mg prevents coronary spasm in patients with vasospastic angina (VSA).

DESIGN

Effectiveness trial.

SETTING

University medical center.

PATIENTS

Twenty-two patients with VSA.

INTERVENTION

Coronary spasm was induced with an intracoronary infusion of acetylcholine (Ach). After spontaneous relief of the coronary spasm, Mg sulfate (0.27 mmol/kg body weight) was infused IV over 20 min in 14 patients and isotonic glucose was infused in 8 patients as control subjects. Intracoronary infusion of Ach was then repeated, and the diameter of the coronary arteries was measured quantitatively.

MEASUREMENTS AND RESULTS

Mg infusion caused coronary artery dilatation at baseline in both the spastic (5. 9 +/- 2.3%) and nonspastic segments (5.5 +/- 1.5%). Mg infusion reduced the severity of chest pain and ST-segment deviations during coronary spasm. After the Mg infusion, the percent change in the diameter of the spastic segments improved from - 62.8 +/- 2.6% to - 43.7 +/- 4.7% during coronary spasm. Overall, 10 of 14 patients (71%) responded favorably to Mg infusion. Isotonic glucose infusion did not elicit changes in chest pain severity, ST-segment deviations, or the diameter of the coronary arteries during spasm.

CONCLUSIONS

Mg infusion produces nonsite-specific basal coronary dilatation and suppresses Ach-induced coronary spasm in patients with VSA.

Evaluation of flash echo imaging of the canine gastrointestinal tract

Although it is important to assess gastrointestinal blood flow, no generally useful, noninvasive assessment method has been established. Harmonic flash echo imaging, which is an intermittent second harmonic imaging technique, has recently become available to evaluate blood flow. We investigated the usefulness of harmonic flash echo imaging in the assessment of the gastrointestinal tract, and we used this technique to study the effect of nicotine on small bowel blood flow. Harmonic flash echo imaging was performed at the beginning of intravenous injection of a contrast agent. It was also performed on the small bowel immediately before and 10 min after nicotine administration to evaluate blood flow. Gastric and small bowel walls were clearly enhanced on the primary images. Small bowel enhancement, which is regarded as transmural blood flow, significantly decreased after nicotine administration. Harmonic flash echo imaging appears to be useful in the assessment of the transmural blood flow in the gastrointestinal wall.

Bilirubin overload modulates bile canalicular membrane fluidity in rats: association with disproportionate reduction of biliary lipid secretion

We recently demonstrated that several organic anions cause dissociation of biliary lipid secretion from that of bile acids; namely, the "uncoupling phenomenon," in association with changes in the phospholipid molecular species in the canalicular membrane lipid bilayer. Because of the uncoupling phenomenon, transcytotic vesicles are retained inside cells, resulting in the accumulation of substances normally excreted in the bile. In the present study, bilirubin ditaurate (BDT; synthetic bilirubin) was used to investigate the effect of bilirubin overload on biliary lipid secretion and the lipid composition of hepatic subcellular fractions, as well as canalicular membrane packing density and fluidity. Male Sprague-Dawley rats underwent cannulation of the bile duct and femoral vein. Sodium taurocholate was infused intravenously at 100 nmol/min per 100 g body weight. Then BDT (50 nmol/min per 100 g body weight) was infused concomitantly, followed by periodic bile collection for analysis of lipids. Bile acid secretion was not significantly affected by the infusion of BDT. In contrast, the secretion of cholesterol and phospholipids was decreased by 56.7% and 49.2%, respectively, compared with control. The phosphatidylcholine hydrophobicity of canalicular membrane vesicles, estimated by the molar ratio of saturated to unsaturated fatty acids (S/U ratio) was decreased, but not significantly by BDT infusion. With BDT infusions, the biliary cholesterol/phospholipid (C/P) ratio was increased by 19%; canalicular membrane vesicle fluidity was decreased by 5.8%, whereas P-glycoprotein expression was unchanged. As P-glycoprotein expression was not altered, our findings suggested that the reduced canalicular membrane vesicle fluidity was a crucial regulator of canalicular membrane transporter function.

Factors affecting gallstone recurrence after successful extracorporeal shock wave lithotripsy

Ninety-six patients treated successively for symptomatic cholelithiasis with extracorporeal shock wave lithotripsy (ESWL) and oral bile acid therapy consisting of ursodeoxycholic acid in daily dosages of 600 mg were prospectively followed for gallstone recurrence for a median of 13 months. Ultrasonography was performed to detect stone recurrence at 3, 6, and 12 months, and then yearly after the termination of therapy. Recurrent stones were found in 17 patients (18%). The cumulative probability of gallstone recurrence was 15.8% at 12 months, 26.1% at 24 months, and 30.7% at 36 months. The probability of stone recurrence over the entire period of observation was not dependent on stone number, whereas the median interval to detection of recurrence was significantly shorter in the patients with multiple stones (2 months) than in those with solitary stones (8 months) (p < 0.05). The rate of impaired gallbladder contractility was higher in patients with recurrence (8/15, 53.3%) when compared with those with no recurrence (15/72, 20.8%) (p < 0.01). Neither age, gender, or stone characteristics predicted stone recurrence. Only one patient with a recurrence reported biliary pain. Of the 15 patients with recurrent stones who opted for further nonsurgical treatment, complete stone disappearance was achieved in 10. Impaired gallbladder function may predict gallstone recurrence after ESWL.

Growth characteristics of rectal carcinoid tumors

PURPOSE

Tissue growth depends on both cell proliferation and cell death. This study was designed to examine the growth characteristics of rectal carcinoid tumors.

METHODS

Fifty rectal carcinoid tumors were studied clinicopathologically and experimentally. Expression of Ki-67, TGF-alpha, p53, and bcl-2 was examined immunohistochemically, and apoptotic cells were identified by the in situ DNA nick end labeling method. EGF receptor expression was examined by a colorimetric in situ mRNA hybridization technique.

RESULTS

The median Ki-67 labeling index (LI) in all lesions was 0.62 +/- 0.59%. Ki-67 LI was significantly (p < 0.01) higher in lesions larger than 5 mm than in lesions smaller than 5 mm. TGF-alpha was expressed more frequently (p < 0.01) in lesions larger than 5 mm (100%) than in lesions smaller than 5 mm (65.2%). Ki-67 LI was significantly (p < 0. 05) higher in lesions with TGF-alpha expression than in lesions without TGF-alpha expression. The in situ hybridization revealed EGF receptor expression in all 46 lesions with intact mRNA (100%), and coexpression of TGF-alpha and EGF receptor was found in 39 of the 46 (84.8%) lesions. The median apoptotic index (AI) in all lesions was 0.15 +/- 0.12%. AI has increased with tumor size and was significantly (p < 0.05) higher in lesions with a higher Ki-67 LI than in lesions with a lower Ki-67 LI. p53 protein was detected in only 1 patient who had liver metastases, and the gene mutation was confirmed by polymerase chain reaction and single-strand conformation polymorphism analysis. bcl-2 expression was absent in all lesions.

CONCLUSIONS

The Ki-67 LI indicated a low cellular proliferative activity in rectal carcinoid tumors. AI was very low, and was significantly correlated with proliferative rate. Inhibition of apoptosis by mutated p53 or bcl-2 may not have occurred in most of these tumors. TGF-alpha/EGF receptor autocrine mechanisms may play a possible role in tumor growth, and the cellular proliferative activity may increase as tumors grow larger.

[Evaluation of vascular endothelial function]

Endothelial function was evaluated in renal and forearm vessels from patients with essential hypertension. First, the increase in renal blood flow evaluated by the clearance of para-aminohippurate, serum c-GMP and urinary NOx during L-arginine infusion was significantly attenuated in essential hypertension. This attenuated endothelium-dependent vasodilation was improved by angiotensin converting enzyme inhibitor, but unchanged by calcium antagonist. Second, the increase in forearm blood flow evaluated by plethysmography during acetylcholine infusion or reactive hyperemia was attenuated in essential hypertension. This attenuation was abolished by NO synthesis inhibitor. Forearm endothelial function was improved by angiotensin converting enzyme inhibitor, daily aerobic exercise and body weight reduction by low calorie diet. In conclusion, endothelium-dependent vasodilation was attenuated in renal and forearm vasculature of essential hypertensives via reduction of NO synthesis. This attenuation can be improved by several treatments.

Real-time ultrasonographic assessment of antroduodenal motility after ingestion of solid and liquid meals by patients with functional dyspepsia

BACKGROUND AND AIMS

Although antroduodenal motility has usually been studied by using manometric or scintigraphic methods, ultrasonography is an established, non-invasive method to evaluate duodenogastric motility. We used ultrasonography to evaluate gastric motility in patients with functional dyspepsia.

METHODS

Sixty-four patients with functional dyspepsia and 36 asymptomatic healthy subjects were given liquid and solid test meals. We investigated the gastric emptying rate, motility index, and duodenogastric reflux for the liquid meal and gastric emptying time, half-emptying time, and motility index for the solid meal.

RESULTS

After the liquid meal, the gastric emptying rate and motility index were significantly lower and the duodenogastric reflux was significantly higher in functional dyspepsia patients than in healthy subjects. After the solid meal, gastric emptying time, half-emptying time and the motility index were significantly lower in the patients than in the healthy subjects. Delayed gastric emptying of both meals occurred in only 20.3% of patients. Delayed emptying of the liquid or solid meal occurred in 62.5% of patients. In both groups, gastric emptying time of the solid meal was positively correlated with the motility index at 15 min post-ingestion.

CONCLUSION

In functional dyspepsia patients, delayed gastric emptying of a solid meal was related to antral hypomotility during the early postprandial phase. Ultrasonographic assessment of gastric motility in both liquid and solid meals may provide a better understanding of the pathogenesis of functional dyspepsia.

Immuno-histochemical detection of human telomerase reverse transcriptase in human liver tissues

Although telomerase activity in hepatocellular carcinoma (HCC) increases in accordance with degree of histological undifferentiation, it is unknown whether the level of telomerase activity in HCC reflects of the degree of activity in individual cells or the frequency of telomerase-positive HCC cells. Non-cancerous liver tissues exhibit low but significant levels of telomerase activity, but the nature of telomerase-positive cells in these tissues is unclear. In this study, we performed immunohistochemical staining using specific antibody against telomerase reverse transcriptase (hTERT) protein in 15 HCC samples and 13 adjacent non-cancerous liver tissues. There were hTERT-positive hepatocytes, though very low frequency, in non-cancerous liver tissues. The frequencies in hTERT positive hepatocytes were very well correlated with clinicopathological parameters and telomerase activity levels: the average frequencies of chronic hepatitis was 0.2%, liver cirrhosis 0.2%, well-differentiated HCC 3.0%, moderately differentiated HCC 28%, and poorly differentiated HCC 95%. The intensity of staining varied among cells within a given specimen, and correlation with degree of histological undifferentiation was less obvious. Portions of migrating lymphocytes and biliary epithelial cells were also hTERT-positive. These findings indicate that the upregulation of telomerase activity with degree of undifferentiation of HCC is mainly due to the increase in frequency of hTERT positive HCC cells.

Electrocautery snare resection stimulates cellular proliferation of residual colorectal tumor: an increasing gene expression related to tumor growth

PURPOSE

Recently, endoscopic mucosal resection has been performed commonly for colorectal tumors. However, incomplete endoscopic mucosal resection produces a residual tumor that grows rapidly. The aim of this study was to clarify the characteristics of the residual tumor using the nude mouse model.

METHODS

Human colon cancer cells (colo201 or colo320DM) were implanted subcutaneous into nude mice. We then removed more than one-half of the tumor with an electrocautery snare or a surgical knife, and compared the tumor growth rate with that of control tumors. Before and after resection, we examined the Ki-67 labeling index of the tumors with an immunohistochemical assay and mRNA expression for epidermal growth factor receptor, vascular endothelial growth factor, and transforming growth factor alpha.

RESULTS

Residual tumors showed a higher growth rate in tumor volume than control tumors using both methods (electrocautery snare and surgical knife). Colo201 groups showed a higher total volume change per day than colo320DM groups after resection. Furthermore, these tumors also showed a higher Ki-7 labeling index, and a stronger epidermal growth factor receptor and transforming growth factor alpha mRNA expression than primary and control tumors in the colo201 implanted groups. There was no significant difference in vascular endothelial growth factor mRNA expression between groups implanted with colo201 or colo320DM.

CONCLUSION

Our results suggest that residual tumors caused by incomplete endoscopic mucosal resection may have a higher growth potential than the tumors before resection.

Biliary excretory function is regulated by canalicular membrane fluidity associated with phospholipid fatty acyl chains in the bilayer: implications for the pathophysiology of cholestasis

BACKGROUND AND AIMS

Bile canalicular membrane fluidity is modulated by phospholipid molecular species within membrane lipid bilayers. Thus, organellar membrane lipid composition is a determinant of canalicular function. In this study, the effect of phalloidin-induced cholestasis on bile lipid composition and liver subcellular membrane fraction composition in rats was examined to clarify the relationship between cholestasis and hepatic lipid metabolism.

METHODS AND RESULTS

Each rat received one phalloidin dose (400 microg/kg, i.v.). After the bile was collected, liver microsomes and canalicular membranes were analysed. The bile flow rate decreased by 50% 3.5 h after phalloidin administration. Although the bile acid output remained almost the same, the phospholipid and cholesterol output were significantly decreased (by 40.3+/-5.97% and 76.9+/-5.56%, respectively). Thus, the cholesterol:phospholipid (C:P) ratio in bile was significantly decreased by 80.4+/-10.1%. Phalloidin administration also increased the saturated: unsaturated fatty acid ratio (S:U) in bile for phosphatidylcholine by 25.5+/-3.2%. In the canalicular membrane, the C:P and S:U ratios for phosphatidylcholine were increased (24.8+/-4.2% and 34.4+/-6.9%, respectively), while the S:U for sphingomyelin was decreased by 61.0+/-6.2%. In microsomes, the C:P was decreased by 41.0+/-6.0%, but the S:U for both phosphatidylcholine and sphingomyelin were unaffected. Canalicular membrane fluidity, assayed by 1,6-diphenyl-1,3,5-hexatriene fluorescence depolarization, decreased significantly. Therefore, increased secretion of hydrophobic phosphatidylcholine into bile was associated with more hydrophobic canalicular membrane phosphatidylcholine, while sphingomyelin in the canalicular membrane was less hydrophobic.

CONCLUSIONS

These results indicate that phalloidin uncouples secretion of cholesterol and phospholipids, which causes a redistribution of fatty acyl chain species among canalicular membrane phospholipids that alters membrane fluidity. These changes may be a homeostatic response mediated by the phospholipid translocator in the canalicular membrane, although direct evidence for this is unavailable.

Cetraxate, a mucosal protective agent, combined with omeprazole, amoxycillin, and clarithromycin increases the eradication rate of helicobacter pylori in smokers

BACKGROUND

Our previous study demonstrated that Helicobacter pylori eradication was less effective in smokers than in non-smokers. Cetraxate is an anti-ulcer drug that increases gastric mucosal blood flow.

AIM

To evaluate the effect of cetraxate combined with new triple therapy for the eradication of H. pylori in smokers.

METHODS

This study had a single-centre, double-blind, randomized non-placebo design. A total of 106 consecutive H. pylori-positive smoking patients were randomly allocated to one of two regimens: one group received omeprazole (20 mg), amoxycillin (1500 mg), and clarithromycin (600 mg) for 7 days (OAC, n=55). The other group recieved OAC plus cetraxate (600 mg) for 7 days (OAC + CET, n=51). The success of H. pylori eradication was evaluated by histology and the 13C-urea breath test at 4 weeks after completion of treatment.

RESULTS

By intention-to-treat analysis, the H. pylori eradication rate was 55% in the OAC group and 92% in the OAC + CET group (P<0.01). By per protocol analysis, the H. pylori eradication rate was 58% in the OAC group and 94% in the OAC + CET group (P<0.01).

CONCLUSION

Cetraxate combined with new triple therapy increases the eradication of H. pylori in smokers.

Detailed colonoscopy for detecting early superficial carcinoma: recent developments

Early superficial colorectal carcinoma (CRC) has been commonly detected by routine colonoscopic examination in Japan. A series of 769 early CRCs and 4821 adenomas were diagnosed by colonoscopy at Hiroshima University Medical Hospital between 1991 and 1998. Of early CRCs, macroscopically superficial early CRCs accounted for 209 lesions (28%). Among 5590 lesions of adenomas and carcinomas, depressed-type lesions showed a significantly higher malignant potential for cancerous and submucosal invasion than elevated lesions (polypoid, IIa-type lesions, and G-LST). As one of the quantitative examinations for early CRC, pit pattern observed by magnifying video-colonoscopy was useful. We performed magnifying observations for 265 lesions of colorectal neoplasias using Kudo's pit pattern classification for 2 years. Depressed-type lesions characterized the Ills and V pit patterns, and elevated lesions characterized the III(L) pit pattern. The incidence of cancer was significantly higher in lesions with IIIs and V pit patterns. Furthermore, the V(N) pit pattern was considered a significant indicator of submucosal invasion. These results indicated that superficial early CRC could be considered to constitute about one-third of all early CRCs. Of them, the depressed-type lesions showed a significantly higher malignant potential than elevated lesions. Pit pattern observation by magnifying videocolonoscopy is useful for predicting the histology/invasion depth of early CRC.

Regulation of disease-progression genes in human gastric carcinoma cells by interleukin 8

The expression of interleukin 8 (IL-8) by human gastric carcinomas directly correlates with tumor vascularity and disease progression. To determine whether IL-8 can act in an autocrine manner to regulate the expression of other disease-progression genes, we examined the expression of IL-8 receptors IL-8RA (CXCR1) and IL-8RB (CXCR2) in six different human gastric carcinoma cell lines and 38 surgical specimens of human gastric carcinomas. All of the gastric carcinoma cell lines expressed mRNA and protein for IL-8RA and IL-8RB protein. In all surgical specimens, the majority of the tumor cells and small vessel endothelial cells stained positive for IL-8RA and IL-8RB protein. In vitro treatment of human gastric cancer MKN-1 cells with exogenous IL-8 enhanced the expression of epidermal growth factor receptor, type IV collagenase (metalloproteinase-9), vascular endothelial growth factor, and IL-8 mRNA. In contrast, treatment with exogenous IL-8 decreased expression of E-cadherin mRNA. IL-8 treatment increased invasive capacity of MKN-1 cells, which was associated with activity of metalloproteinase-9. Collectively, these results demonstrate that human gastric carcinoma cells express receptors for IL-8 and that IL-8 may play a role in the progressive growth of human gastric carcinoma by autocrine/paracrine mechanisms.

Role of phospholipase A2 in cholesterol gallstone formation is associated with biliary phospholipid species selection at the site of hepatic excretion: indirect evidence

Phospholipase A2 plays a role in cholesterol gallstone development by hydrolyzing bile phospholipids into lysolecithin and free fatty acids. Lysolecithin and polyunsaturated free fatty acids are known to stimulate the synthesis and/or secretion of gallbladder mucin via a prostanoid pathway, leading to enhancing cholesterol crystal nucleation and growth, and therefore, the action of phospholipase A2 is associated, in part, with bile phospholipid fatty acid. To clarify this hypothesis, we evaluated the effect on bile lipid metastability in vitro of replacing phospholipids with lysolecithin and various free fatty acids. Supersaturated model biles were created with an identical composition (cholesterol saturation index, 1.8; egg yolk lecithin, 34 mM; taurocholate, 120 mM; cholesterol, 25 mM) except for 5%, 10%, or 20% replacement of egg yolk lecithin with a combination of palmitoyl-lysolecithin and a free fatty acid (palmitate, stearate, oleate, linoleate, or arachidonate), followed by time-sequentially monitoring of vesicles and cholesterol crystals using spectrophotometer and video-enhanced differential contrast microscopy. Replacement with hydrophilic fatty acids (linoleate and arachidonate) reduced vesicle formation and promoted cholesterol crystallization, whereas an enhanced cholesterol-holding capacity was evident after replacement with hydrophobic fatty acids (palmitate and stearate). These results indicate that the effect of phospholipase A2 on bile lithogenecity is modulated by the fatty acid species in bile phospholipids, and therefore, that the role of phospholipase A2 in cholesterol gallstone formation is dependent, in part, on biliary phospholipid species selection at the site of hepatic excretion.

Predictive value of cathepsin D and Ki-67 expression at the deepest penetration site for lymph node metastases in gastric cancer

To search for reliable predictors for lymph node metastasis, we immunohistochemically analyzed surgically resected gastric cancer specimens that showed invasion of submucosa (sm) and muscularis propria (mp) of the tumor. The analysis investigated cathepsin D and Ki-67 expression in 136 specimens that were divided into an sm1/sm2 group and an sm3/mp group. In sm1/sm2 group, the incidence of lymph node metastases was significantly higher in tumors with high Ki-67 labeling index (LI) (44%) than in those with low Ki-67 LI (0%). In sm3/mp group, the incidence of lymph node metastases was significantly higher in cathepsin D-positive (56%) and high Ki-67 LI tumors (64%) than in cathepsin D-negative (33%) and low Ki-67 LI (33%). Combined analysis of cathesin D expression and Ki-67 LI correlated strongly with lymph node metastases. No lesions with cathepsin D-negative expression and low Ki-67 LI had lymph node metastases in either group. Cathepsin D and Ki-67 expression may be useful predictors for lymph node metastases in gastric cancer with sm and mp invasion. As predictors, they can identify lesions without lymph node metastases and indicate lesions not needing additional treatment after endoscopic mucosal resection and laparoscopic gastrectomy.

Enhanced tumorigenicity of insulinoma by X-irradiation of the gastric regions in Sprague-Dawley male rats

BACKGROUND AND AIMS

There has been no suitable animal model for human insulinoma because incidence of pancreatic tumours induced by whole-body irradiation or chemicals has been very low. The purpose of this study was to establish an experimental model with a high incidence of insulinoma. The induction of islet cell tumour by X-irradiation was investigated.

METHODS

Forty Sprague-Dawley male rats were used in this study. Twenty-eight rats were irradiated with two 10-Gy doses to the gastric region at a 3-day interval, and 12 rats not subjected to X-irradiation served as a control group. The rats were killed 16 months after the first irradiation. Expression of insulin mRNA and protein was examined by northern blot analysis and immunohistochemistry, respectively. Rat serum insulin and glucose levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Tumour incidence was 89.3% (25/28) in X-ray group and 8.3% (1/12) in the control group (P < 0.05). Pancreatic tumours, which appeared in all 25 rats with tumours, showed the highest incidence of all neoplasms detected. Tumour cells showed strong immunoreactivity for insulin in 20 of 25 pancreatic tumours (80%). Expression of insulin mRNA was confirmed by northern blot analysis. Furthermore, rats with pancreatic tumours had lower serum glucose levels and higher insulin levels than the control rats.

CONCLUSION

X-irradiated SD rats may be considered a suitable model for insulinoma because of their high tumorigenicity.

Type 1A dopamine receptor expression in the heart is not altered in spontaneously hypertensive rats

We have recently demonstrated that type 1A dopamine (D1A) receptor is expressed in the rat heart, but its function still remains unknown. In the present study, we investigated possible changes in the expression level and the distribution of the cardiac D1A receptor in the development of left ventricular hypertrophy in spontaneously hypertensive rats/Izumo strain (SHR/Izm) at the ages of 4, 8, and 20 weeks. We examined D1A receptor protein distribution by immunohistochemistry and gene expression by competitive polymerase chain reaction (competitive PCR). In SHR/Izm, compared with the age-matched Wistar Kyoto rats/Izmo strain (WKY/Izm), blood pressure and heart/body weight ratio were significantly increased at 8 and 20 weeks. By immunohistochemistry, the D1A receptor was localized in cardiomyocytes and vascular smooth muscle cells of coronary arteries, but not in interstitial fibrotic tissue. D1A receptor distribution was not changed either by the strain or the age. Competitive PCR analysis showed that the D1A receptor mRNA level was significantly higher at 4 weeks than at 8 and 20 weeks in both strains of rats and that there was no significant difference in D1A receptor mRNA between SHR/Izm and WKY/Izm at any age (43.2 +/- 10.4 attomol x 10(-3)/L v 43.1 +/- 11.2 attomol x 10(-3)/L at 4 weeks, P = not significant, 3.9 +/- 0.9 attomol x 10(-3)/L v 4.0 +/- 1.3 attomol x 10(-3)/L at 8 weeks, P = not significant, 3.0 +/- 1.2 attomol x 10(-3)/L v 1.9 +/- 1.6 attomol x 10(-3)/L at 20 weeks, P = not significant). These results do not support the hypothesis that changes in D1A receptor expression are associated with the development of left ventricular hypertrophy in SHR.

Acid-sensitive and alkaline-sensitive sensory neurons regulate pH dependent gastrin secretion in rat

We examined the role of capsaicin-sensitive afferent neurons in pH-dependent gastrin secretion in the rat stomach. The change in serum gastrin levels relative to changes in luminal pH (using omeprazole for luminal alkalization or 0.1 N HCl for luminal acidification) was studied after oral administration of 4% lidocaine or capsaicin-induced ablation of afferent neurons. The increase of serum gastrin levels by luminal alkalization was significantly inhibited (50%) after administration of 4% lidocaine. Capsaicin pretreatment (125 mg/kg subcutaneously over two days) inhibited the change in serum gastrin levels both the luminal alkalization (38%) and acidification (66%). Antral gastrin contents, somatostatin contents, gastrin mRNA expression, and somatostatin mRNA expression were not significantly affected by capsaicin pretreatment. Our results indicate that capsaicin-sensitive afferent neurons participate in the secretion of gastrin by luminal alkalization and inhibition of gastrin by luminal acidification.