Biomedical subjects

A Toyonaga

Publications and source records attributed to A Toyonaga.

At least 73 records · Page 4Linked to original sources

PubMed1997

Effects of glucagon on superior mesenteric artery and femoral artery haemodynamics in humans.

OBJECTIVE: It remains unclear whether glucagon is a localized splanchnic arterial vasodilator in humans. This study examined this issue by assessing the haemodynamic effect of exogenous glucagon on splanchnic and extrasplanchnic arteries. METHODS: After an overnight fast, flow velocity of superior mesenteric artery and femoral artery was recorded by means of echo-Doppler in 10 controls and 10 patients with cirrhosis. Mean arterial pressure, heart rate and plasma glucagon level were also determined. These measurements were repeated after intramuscular injection of glucagon (1 mg) at 15 min and 30 min. RESULTS: Patients with cirrhosis had much higher glucagon levels than controls (P < 0.01). Plasma glucagon level rose following glucagon administration in controls (P < 0.01) and patients with cirrhosis (P < 0.01). Glucagon administration had no effect on mean arterial pressure, heart rate and femoral artery velocity in controls and patients with cirrhosis. In contrast, superior mesenteric artery velocity significantly increased after glucagon administration in both groups (P < 0.01, P < 0.01), although the effect was less pronounced in patients with cirrhosis than in controls (P < 0.05). CONCLUSION: These data suggest that glucagon might be a localized splanchnic arterial vasodilator. Thus, glucagon may be one of the factors contributing to the pathogenesis of the splanchnic hyperdynamic circulation seen in patients with cirrhosis.

Aged↗

PubMed1996

Gastric mucus generation in cirrhotic patients with portal hypertension. Effects of tetraprenylacetone.

We have evaluated gastric mucus generation (study 1) and the effects of tetraprenylacetone on gastric mucus generation (study 2) in cirrhotic patients with portal hypertension. Study 1: Included were 50 noncirrhotics (group A), 25 cirrhotics without portal hypertension (group B), and 25 cirrhotics with portal hypertension (group C). The antrum, corpus, and fundus mucus generation was assessed by hexosamine concentration using biopsy specimens. In groups A and B, the antrum hexosamine concentration was significantly higher compared with the corpus (P < 0.01, P < 0.01) and the fundus (P < 0.01). In contrast, the hexosamine concentration at each location was similar in group C. Furthermore, the antrum hexosamine concentration of group C was significantly lower compared with that of group A (P < 0.05). In study 2, a double-blind design, 300 mg of tetraprenylacetone was administered for four weeks in 10 cirrhotics with portal hypertension and placebo in 10. The regional hexosamine concentrations were measured before and after drug administration. Placebo administration did not change hexosamine concentration at each location. In contrast, tetraprenylacetone increased the antrum and corpus hexosamine concentration (P < 0.01, P < 0.05), although the fundus concentration did not change. These data suggest that cirrhotics with portal hypertension have reduced gastric antral mucus generation and tetraprenylacetone normalizes this.

Anti-Ulcer Agents↗

PubMed1996

Evaluation of patient outcome following sclerotherapy for esophageal varices.

After excluding terminally all patients, we evaluated a total of 718 patients treated with endoscopic injection sclerotherapy. They involved 350 episodes of acute hemorrhage and 368 prophylactic procedures in patients with risky varices. The 1-year cumulative survival rate was significantly lower in the acute hemorrhage group than in the prophylactic group (P < 0.05). The difference in survival between the two groups was primarily due to the number of deaths in the first 2 months after sclerotherapy (20.1% vs 0.8%, P < 0.0005). Improvements in the sclerotherapy technique significantly reduced the number of deaths from bleeding (9.3% vs 3.4%, P < 0.05), but not those from liver failure following variceal hemorrhage. Prophylactic EIS is advantageous in the treatment of esophageal varices, i.e. it may prevent deaths from liver failure attributed to variceal hemorrhages. The present study shows that preliminary prevention of variceal hemorrhage provides favorable hemostatic efficacy in patients with risky varices.

Cause of Death↗

PubMed1996

Effect of vasopressin on esophageal varices blood flow in patients with cirrhosis: comparisons with the effects on portal vein and superior mesenteric artery blood flow.

BACKGROUND/AIMS: Vasopressin reduces portal pressure which may be due to decreased portal inflow. However, it remains unclear whether vasopressin is able to selectively reduce esophageal varices blood flow. The aim of this study was to address this question. METHODS: Fifteen patients with cirrhosis and esophageal varices were included in this prospective study. Portal vein and superior mesenteric artery flow velocity were measured with a percutaneous echo-Doppler. Esophageal varices flow velocity was measured using a transesophageal echo-Doppler technique. Mean arterial pressure and heart rate were also recorded. These measurements were performed at baseline condition and 15 min after observer blind drug administration. In this study, two groups, six patients receiving placebo and nine patients receiving 0.3 U/min of vasopressin, were randomized according to the coded number. RESULTS: Placebo administration had no effect on systemic and splanchnic circulation. In contrast, vasopressin administration increased mean arterial pressure (p < 0.05) associated with a bradycardia (p < 0.01). In splanchnic circulation, vasopressin decreased portal vein (-32 +/- 3%, p < 0.01), superior mesenteric artery (-30 +/- 2%, p < 0.01), and esophageal varices flow velocity (-48 +/- 5%, p < 0.01). When the magnitude of these reductions was compared, ANOVA showed a significant difference (p < 0.01). Furthermore, the reduction in esophageal varices flow velocity was significantly higher than that in portal vein flow velocity (p < 0.01) and that in superior mesenteric artery flow velocity (p < 0.01). CONCLUSIONS: These data support the view that vasopressin is able to selectively reduce esophageal varices blood flow. This effect, in addition to its well-established portal pressure reducing action, may play a role in its therapeutic efficacy in the treatment of variceal bleeding.

Aged↗

PubMed1996

Echo-Doppler measurements of portal vein and superior mesenteric artery blood flow in humans: inter- and intra-observer short-term reproducibility.

The reproducibility of echo-Doppler measurements of portal vein and superior mesenteric artery blood flow has not been extensively studied. In the present study, two groups of subjects were examined to test inter- and intra-observer reproducibility. Each study population consisted of 15 nonportal hypertensive and 15 portal hypertensive subjects. With a standardized technique, the crosssectional area and velocity of blood flow in the portal vein and superior mesenteric artery were recorded in triplicate by skilled operators. The flow volume of each vessel was calculated by multiplying the cross-sectional area by the velocity of blood flow. The measurements were performed in a blind fashion over a 60 min period. The reproducibility of measurements was assessed by calculation of intraclass correlation coefficients and coefficients of variation. The intra-observer intraclass correlation coefficient was 0.77 for portal vein blood flow and 0.84 for superior mesenteric artery blood flow, suggesting good reproducibility. The intra-observer coefficient of variation was 11 and 9%, respectively. In contrast, the interobserver intraclass correlation coefficient was calculated to be 0.49 for portal blood vein blood flow and 0.57 for superior mesenteric artery blood flow, indicating fair reproducibility. In addition, the interobserver coefficients of variation were calculated to be 20 and 18%, respectively. These data suggest that intra-observer reproducibility in echo-Doppler measurements of portal vein and superior mesenteric artery blood flow is acceptable but inter-observer reproducibility is not. Examination by a single operator, rather than multiple operators, is therefore advisable. Even when measurements are performed by a single investigator an approximate variance of 10% in the measurement in a single subject should be expected.

Adult↗

PubMed1996

Vasopressin plus oxygen vs vasopressin alone in cirrhotic patients with portal-hypertensive gastropathy: effects on gastric mucosal haemodynamics and oxygenation.

The effects of vasopressin plus oxygen and vasopressin alone on gastric mucosal perfusion and oxygenation were studied using reflectance spectrophotometry and laser Doppler velocimetry in 23 cirrhotic patients with portal-hypertensive gastropathy. The measurements were performed under basal conditions and after double-blinded administration of placebo (n = 7), vasopressin (0.3 U/min; n = 8) or vasopressin (0.3 U/min) plus nasal oxygen (4 L/min; n = 8). No significant effects on gastric mucosal haemodynamics and oxygenation were observed after placebo. In contrast, vasopressin and vasopressin plus oxygen induced a similar reduction in haemoglobin content (-26 +/- 2 and -21 +/- 4%, respectively P < 0.01), and laser Doppler signal (-23 +/- 2 and -22 +/- 2%, respectively, P < 0.01). Although each treatment induced a significant reduction in oxygen saturation (-21 +/- 2 and -7 +/- 1%, respectively P < 0.01), the effect was less pronounced in patients receiving the combination than in those receiving vasopressin alone (P < 0.01). These data suggest that vasopressin and vasopressin plus oxygen reduce gastric mucosal hyperaemia and that the oxygen supplement partially protects against gastric mucosal hypoxia during vasopressin infusion in cirrhotic patients with portal-hypertensive gastropathy.

Aged↗

PubMed1996

Distinctive portal venographic pattern in patients with sclerotherapy resistant oesophageal varices.

We performed prophylactic sclerotherapy in 350 patients with 'high risk' oesophageal varices (F2 or F3 with a moderate or severe red colour sign). Of these patients, eight exhibited sclerotherapy resistance (i.e. no significant reduction in the size of varices after five sessions of sclerotherapy). Thus, the prevalence of sclerotherapy resistant varices was 2%. Of 350 patients, 97 underwent haemodynamic investigation before sclerotherapy. This group consisted of seven patients with sclerotherapy resistant varices and 90 patients with non-resistant varices. Portal pressure, assessed by portal venous pressure gradient, was similar in these two groups (21.5 +/- 4.8 vs 19.8 +/- 5.0 mmHg, respectively; NS). However, the prevalence of the 'pipe-line' form of variceal feeding pattern (a large dilated left gastric vein running up the oesophagus) was higher in patients with resistant varices than in those with non-resistant varices (100 vs 3%, respectively; P < 0.01) and the diameter of the left gastric vein was larger in patients with resistant varices than in those with non-resistant varices (12.4 +/- 2.0 vs 7.8 +/- 2.3 mm, respectively; P < 0.01). Moreover, the extravariceal portosystemic shunt was poorly developed in patients with resistant varices compared with non-resistant varices (0 vs 52%, respectively; P < 0.05). We conclude that the pipe-line pattern, fed by a large left gastric vein and associated with poorly developed extravariceal portosystemic shunt, is a distinctive portal venographic feature of sclerotherapy resistant varices.

Esophageal and Gastric Varices↗

PubMed1996

Hepatic artery hemodynamic responsiveness to altered portal blood flow in normal and cirrhotic livers.

PURPOSE: To compare hepatic artery hemodynamic response to altered portal blood flow in normal and cirrhotic livers. MATERIALS AND METHODS: The portal blood flow and hepatic artery pulsatility index were measured by means of duplex ultrasound before and after subjects (eight control subjects and 10 cirrhotic patients) ingested a 500-kcal mixed-liquid meal and during intravenous infusion of vasopressin at a rate of 0.3 U/min (nine control and nine cirrhotic subjects). The hepatic artery buffer index (ratio of maximum change from baseline in hepatic artery pulsatility index to maximum change from baseline in portal blood flow) was also calculated. RESULTS: Meal consumption increased the portal blood flow and hepatic artery pulsatility index in all subjects. The hepatic artery buffer index, however, was significantly lower in cirrhotic than in control subjects (0.67 min/L +/- 0.06 [standard error of the mean] vs 1.54 min/L +/- 0.20, respectively; P < .01). Vasopressin infusion decreased the portal blood flow and hepatic artery pulsatility index in all subjects. Again, the hepatic artery buffer index was significantly lower in cirrhotic than in control subjects (0.28 min/L +/- 0.07 vs 0.50 min/L +/- 0.04, respectively; P < .05). CONCLUSION: Hepatic artery vascular responsiveness to altered portal blood flow is blunted in cirrhotic livers.

Fasting↗

PubMed1996

Postprandial splanchnic hemodynamic response in patients with cirrhosis of the liver: evaluation with "triple-vessel" duplex US.

PURPOSE: To investigate the effect of a meal on splanchnic circulation in patients with cirrhosis of the liver. MATERIALS AND METHODS: Ten adult patients with cirrhosis and 10 adult control subjects (mean age, 54 years) underwent duplex ultrasonography. Flow volumes of the portal vein, superior mesenteric artery, splenic artery, and collateral vessels (difference between the splanchnic inflow [the sum of the superior mesenteric arterial and the splenic arterial blood flows] and the portal venous blood flow) were measured before and after a meal every 15 minutes for 60 minutes. Integrated post-prandial changes (the sum of the changes at each time point) were also calculated. RESULTS: Portal venous blood flow increased after the meal in control subjects (P < .01) and patients (P < .01). The integrated postprandial change in the portal venous blood flow was lower in patients than in control subjects (P < .05). Superior mesenteric arterial blood flow increased after the meal in control subjects (P < .01) and patients (P < .01); the integrated postprandial change in the superior mesenteric arterial blood flow was similar. In the two groups, splenic arterial blood flow remained unchanged after the meal. Collateral blood flow increased after the meal in patients (P < .01). CONCLUSION: Postprandial portal hyperemia is mainly due to mesenteric arterial vasodilation; reduced postprandial portal hyperemia in patients with cirrhosis is attributable to portocollateral runoff.

Adult↗

PubMed1996

Remnant-stump gastric cancer following partial gastrectomy-clinicopathological studies.

Forty-five cases of remnant-stump (R-S) gastric cancer were investigated retrospectively, comparing those which were initially benign (Group 1: 31 cases) with those which were initially malignant (Group 2: 14 cases). The incidence of R-S gastric cancer over all gastrectomy cases from 1967 to 1994 was 1.4% (45/3,282). The mean period until development of the R-S gastric cancer following partial gastrectomy was 21.6 years in Group 1 and was 15.8 years in Group 2 (p < 0.05). Of those R-S cases that underwent resection, total gastrectomy was selected for 82% in Group 1 and for 85% in Group 2. The incidence of negative lymph nodes was only 25% in Group 1 and 62% in Group 2 (p < 0.05). The pathological stage I was 21% in Group 1 and 54% in Group 2 (p < 0.05). The 5-year-survival rate was 32% in Group 1 and was 62% in Group 2 (p < 0.05). To improve the prognosis for R-S gastric cancer, periodic endoscopic follow-up examinations to find any R-S cancer at the earliest stage is most important, especially in cases of a partial gastrectomy for an initially benign case.

Aged↗

PubMed1996

Mucinous adenocarcinoma of the stomach-clinicopathological studies.

The clinical and morphological features of 58 cases of the rare mucinous adenocarcinoma of the stomach (MUC) were investigated and compared to those of other pathological types. The incidence of MUC was only 2.9% of all cases of resected gastric cancer. Among the 58 cases of MUC, the incidence of early cases was only 19% (Group 1), while among other pathological types of cancer, it was 42% (Group 2) (p < 0.001). The incidence of early mucosal cancer was 0% in Group 1, and 54% in Group 2 of the resected early gastric cancer. The incidence of lymph node metastasis rate was 81% in Group 1, and was 46% in Group 2 (p < 0.001). The presence of peritoneal dissemination was 21% in Group 1, and was 8% in Group 2 (p < 0.001). The incidence of liver metastasis pre- and intraoperatively was 0% in Group 1, and was 3.5% in Group 2. The overall 5-year-survival rate was 45% in Group 1, and was 61% in Group 2 (p < 0.05). In stage III, the 5-year-survival rate was 30% in Group 1, and was 49% in Group 2 (p < 0.05). There was no statistical prognostic difference between the two groups in stage I, II and stage IV. Therefore, to improve the outcome for MUC, more effective radical gastrectomy and aggressive immunochemotherapy should be selected especially for stage III mucinous adenocarcinoma of the stomach.

Adenocarcinoma, Mucinous↗

PubMed1995

Effects of exercise-induced sympathoadrenergic activation on portal blood flow.

We examined the relationship between portal venous blood flow and sympathoadrenergic activation after muscle exercise. For this purpose, we used echo Doppler and measured plasma noradrenaline concentration before and after mild (7 metabolic units, N = 8) and maximal exercise (14 metabolic units, N = 8) in 16 patients without significant disease. Portal venous flow did not change after mild exercise. In contrast, a significant reduction in portal venous flow was observed after maximal exercise (P < 0.01). This was due to reductions in both cross-sectional area of the portal vein (P < 0.01) and portal venous velocity (P < 0.01). Overall, there were significant inverse relationships between the change in plasma noradrenaline concentration and that in cross-sectional area of the portal vein [r = -0.44, P < 0.01 (absolute change); r = -0.47, P < 0.01 (relative change)], that in portal venous velocity (r = -0.63, P < 0.01; r = -0.61, P < 0.01), and that in portal venous flow (r = -0.54, P < 0.01; r = -0.59, P < 0.01). These results suggest that the reduction in portal venous flow after exercise is related to the degree of sympathoadrenergic activation. This reduction may be due mainly to splanchnic vasoconstriction.

Adult↗

PubMed1995

Omeprazole administration does not impair gastrointestinal mucosal perfusion, oxygenation, and hexosamine generation.

Omeprazole is a potent antisecretory drug that acts by inhibiting the gastric proton pump. In the present study, we have observed the effects of this drug on gastrointestinal mucosal perfusion, oxygenation, and hexosamine generation in humans. Sixteen healthy volunteers were included. Gastrointestinal mucosal perfusion and oxygenation (duodenum, antrum, and corpus) were assessed by laser-Doppler flowmetry and reflectance spectrophotometry. Biopsy specimens were also taken from each location to determine hexosamine content as a quantitative indicator of mucus generation. In addition, serum gastrin level was measured. After baseline data were obtained, subjects were randomly assigned to receive 20 mg of oral omeprazole once daily for 7 days (n = 8) or placebo (n = 8). All measurements were performed again after double-blinded drug administration. No effect was found after placebo administration. In contrast, omeprazole administration significantly increased serum gastrin level (p < .05), suggesting an inhibition of acid secretion. However, this drug did not alter either laser-Doppler signal or oxygen saturation at each location. In addition, no change in mucosal hexosamine content was observed at each location. We conclude that oral omeprazole, despite its well-established antisecretory effect, has no adverse effect on the mucosal defense in humans.

Adult↗

PubMed1995

Ethanolamine oleate versus butyl cyanoacrylate for bleeding gastric varices: a nonrandomized study.

BACKGROUND AND STUDY AIMS: Sclerotherapy may be useful in patients with bleeding gastric varices. The aim of this study was to compare the effects of two sclerosants in these patients. PATIENTS AND METHODS: In a prospective nonrandomized trial, we performed single sclerotherapy for bleeding gastric varices using ethanolamine oleate (n = 24) or butyl cyanoacrylate (n = 29). The patients were followed for a mean of 14 months. RESULTS: The rate of initial hemostasis (no bleeding occurred for 48 hours after sclerotherapy) was significantly higher in the butyl cyanoacrylate group (93%) than in the ethanolamine oleate group (67%) (p = 0.014). The rate of initial hemostasis in cardiac variceal bleeding did not differ significantly between the ethanolamine oleate and butyl cyanoacrylate groups (83% vs. 100%, p = 0.140). In contrast, the hemostasis rate for fundal variceal bleeding was significantly higher in the butyl cyanoacrylate group than in the ethanolamine oleate group (88% vs. 50%, p = 0.023). Although the rebleeding rate did not differ between the two groups (30% vs. 25%, p = 0.921), the mortality rate was significantly higher in the ethanolamine oleate group (67% vs. 38%, p = 0.043). In addition, the incidence of complications in the butyl cyanoacrylate group was similar to that in the ethanolamine oleate group (46% vs. 41%, p = 0.745). CONCLUSIONS: These results suggest that initial control of fundal varices is more difficult than it is with cardiac varices, but butyl cyanoacrylate is superior to ethanolamine oleate, and the survival advantage from butyl cyanoacrylate seems to be partially related to the increased early bleeding deaths in the ethanolamine oleate group.

Adult↗

PubMed1995

Soluble interleukin-6 receptors in inflammatory bowel disease: relation to circulating interleukin-6.

The in vivo appearance of soluble interleukin (IL)-6 receptor (sIL-6R) in serum from patients with inflammatory bowel disease was examined using an enzyme linked immunosorbent assay (ELISA). The serum sIL-6R concentrations in patients with active disease (ulcerative colitis, 148.4 (5.1); Crohn's disease, 142.3 (9.3) ng/ml; mean (SEM)) were significantly raised compared with those in patients with inactive disease (ulcerative colitis, 116.2 (7.2); Crohn's disease, 114.3 (7.1) ng/ml), some other type of colitis (104.8 (11.6) ng/ml), or in normal subjects (107.3 (2.4) ng/ml). These differences were also seen in paired samples examined during both active and inactive phases. Additionally, serum sIL-6R and IL-6 concentrations correlated significantly with C-reactive protein levels in both ulcerative colitis and Crohn's disease patients (r = 0.23 and 0.56, respectively; p < 0.05 for both). Furthermore, gel filtration analysis of serum from these patients showed two major peaks of immunoreactive IL-6-one peak corresponding to free IL-6 and another peak to sIL-6R-bound IL-6-this was further confirmed by a luminescence sandwich ELISA. These results, together with its in vitro effects, indicate that natural sIL-6R may function as a powerful enhancer of the IL-6-dependent immune processes observed in inflammatory bowel disease.

Adolescent↗

PubMed1995

Evaluation of intestinal permeability in patients with inflammatory bowel disease using lactulose and measuring antibodies to lipid A.

This study looked at the intestinal permeability and the immune response to enteric bacterial antigens in patients with inflammatory bowel disease (IBD). They were evaluated by using a lactulose tolerance test and measuring blood anti-lipid A antibody concentrations, respectively. The lactulose tolerance tests were performed 22 times in 14 patients with Crohn's disease (CD), 19 times in 12 patients with ulcerative colitis (UC), and 12 times in 12 healthy controls. Blood lactulose concentrations were measured after oral administration every two hours for eight hours, also blood C reactive protein concentrations and anti-lipid A antibody concentrations were measured just before lactulose administration. Blood lactulose concentrations were significantly higher in patients with CD than in the controls from two to eight hours after administration, while in UC they were significantly higher than in the controls from six to eight hours. Maximum blood lactulose concentrations in each tolerance test in patients with the active phase significantly exceeded those in the inactive phase of either CD or UC. A significant correlation was also seen between the maximum blood lactulose concentrations and the C reactive protein concentrations. Blood anti-lipid A antibody concentrations in patients with CD were significantly higher than in the controls as well as in patients with UC in immunoglobulin (Ig) A class and IgG class. In UC they were significantly higher than in the controls in IgA class. But, they were not related to the severity of the disease of either CD or UC, and not correlated significantly with the maximum blood lactulose concentrations in either CD or UC. The intestinal permeability and the immune response to enteric bacterial antigens in patients with inactive CD were significantly increased over those in the controls as well as in patients with inactive UC. These findings suggest that an increase of the intestinal permeability and that of producing antibodies to enteric bacterial antigens are both important for the pathogenesis of IBD, and that the characteristics of CD and UC differ.

Adolescent↗

PubMed1995

Early mucosal gastric cancer with lymph node metastasis.

From 1976 to 1992, a total of 358 cases of mucosal early gastric cancer (m-cancer) were treated by resection in the First Department of Surgery, Kurume University Hospital. Eight (2.2%) of these 358 cases of m-cancer were associated with lymph node metastasis. In these 358 cases, the mean diameter of the tumor was 2.75 cm, and the mean age was 59.6 years. In the 8 cases of m-cancer with positive lymph node metastasis (n(+)), the mean diameter was 5.2 cm and the mean age was 51.6 years. Seven (87.5%) out of the 8 cases of m-cancer with n(+) were IIc macroscopic cancer type and were associated with ulcer and/or ulcer scar.

Adenocarcinoma↗

PubMed1995

Resected early gastric cancer--clinicopathological studies on 610 cases.

A total of 610 cases of early gastric cancer were studied, retrospectively. Of these, 541 (88.7%) cases were single and 62 (10.1%) cases were multiple cancers. Lymph node metastasis occurred in 11.2% of the elevated, in 8.2% of the depressed and in 15.1% of the mixed type. There was no lymph node metastasis when a mucosal or submucosal cancer was less than 10 mm in diameter. By contrast, in the cases in which the preoperative diagnosis was suspected advanced cancer, the incidence of lymph node metastasis was high, at 33%. Therefore, when the preoperative diagnosis is advanced cancer, standard radical gastrectomy and/or extended radical gastrectomy should be selected even though they are found to be early gastric cancer. The age-corrected 5-year survival rate was 98.5% in the cases with no lymph node metastasis and 93.0% in the cases with lymph node metastasis (p > 0.05). The 5-year survival rate was 100% in mucosal cancer and 95.5% in submucosal cancer (p > 0.05).

Adult↗