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Biomedical subjects

F Moriyasu

Publications and source records attributed to F Moriyasu.

At least 55 records · Page 3Linked to original sources

Effect of dobutamine on the arterial ketone body ratio and portal blood flow velocity in cirrhosis.

We studied the relationship between the portal blood flow velocity and the arterial ketone body ratio in patients with chronic liver disease receiving a dobutamine infusion. We used an ultrasonic Doppler duplex system to evaluate the portal blood flow velocity. Dobutamine was given intravenously at 5 micrograms/kg/min for 20 min. Dobutamine infusion induced smaller changes in the portal blood flow velocity and ketone body ratio in liver cirrhosis than in chronic hepatitis. The existence of shunts and the poor increase of the cardiac index in response to dobutamine explained the limited improvement of portal blood flow velocity in cirrhosis patients. The ketone body ratio was improved by dobutamine in cirrhosis patients whose portal blood flow velocity was increased by more than 10%, while this ratio decreased when the increase of it was less than 10%. There was no change in portal oxygen extraction in the cirrhosis group, and portal oxygen uptake only increased when the portal blood flow velocity rose by more than 10%. Dobutamine should only be used to treat liver failure if the portal blood flow velocity is increased by more than 10% or the arterial ketone body ratio is improved by a test infusion.

Blood Flow Velocity↗

Distribution of mesenteric and splenic blood flow in cirrhosis of the liver as estimated by radionuclide angiography.

We used radionuclide angiography following an injection of 185 MBq Tc-99m tin colloid as a non-invasive method for measuring the mesenteric and portal components of the total hepatic circulation, according to the method of Fleming et al (J Nucl Med 24; 1983). Fifty-seven patients with cirrhosis and 33 controls were examined. The relative mesenteric flow (MF) and the relative portal flow (PF) were 68.6 +/- 8.5% and 78.6 +/- 5.9%, respectively, in the control group. These values were 42.0 +/- 16.4% and 70.9 +/- 8.9%, respectively in the cirrhosis group, and were significantly lower than in the controls. In the cirrhosis group, the reduction in PF was small, while that in MF was large. Consequently, we found that portal blood flow was relatively well maintained in the cirrhosis patients, while the contribution of splanchnic blood flow to the portal flow was relatively reduced.

Adult↗

Transcatheter hepatic arterial drug infusion therapy for hepatocellular carcinoma. Effect on the arterial ketone body ratio.

The arterial ketone body ratio (acetoacetate to beta-hydroxybutyrate) was measured in 15 patients with chronic liver disease before and after the infusion of anticancer drugs or embolic agents (gelatin sponge or iodized oil) into the hepatic artery. The arterial ketone body ratio decreased after hepatic angiography and decreased further at 15 min after infusion therapy. When the arterial ketone body ratio decreased to 1.0 or less on at least one occasion after infusion therapy, the ratio after hepatic angiography was always 1.35 or less. Such patients developed marked systemic symptoms like fever and severe liver dysfunction. Ascites also developed in three patients in whom the arterial ketone body ratio was reduced to 0.7 or less at 24 h after infusion therapy. The arterial ketone body ratios improved at 3-7 days after infusion therapy. In the seven patients treated with gelatin sponge embolization, the ratio at 3-7 days after therapy was actually higher than that before angiography.

3-Hydroxybutyric Acid↗

Relief of hepatic vein stenosis by balloon angioplasty after living-related donor liver transplantation.

We have experienced 5 hepatic vein stenoses in 3 children (8 to 23 months old) after living-related liver transplantation (total 48 liver transplants for 48 children between June 1990 and November 1992). The initial symptoms of hepatic vein stenosis were ascites and/or edema. The blood flow of hepatic vessels was monitored by duplex sonography. The mean velocity of the hepatic vein and the portal vein was decreased and flow wave pattern of the stenotic hepatic vein was flat. The patients were treated by percutaneous transhepatic balloon angioplasty. After a successful angioplasty, the mean velocity of the hepatic vein and portal vein increased and pulsatile waves returned to the hepatic vein. Arterial ketone body ratio (acetoacetate/3-hydroxybutylate) increased, promptly followed by recovery of other liver function tests. In 1 patient, this complication occurred three times with intervals of 7 months and 3 months between episodes of hepatic vein stenosis. In conclusion, hepatic vein flow should be monitored routinely with duplex sonography after living-related donor liver transplantation. Percutaneous transhepatic balloon angioplasty is a primary treatment for the stenosis.

Anastomosis, Surgical↗

Doppler ultrasound in diagnosis of liver tumor and portal hypertension.

Technical aspects (equipment, presetting, enhancement) are considered together with new approaches like interventional radiology and Doppler ultrasound. In liver tumors Doppler US not always shows typical patterns: in hemangioma there is usually poor vascularization, while in malignant tumors the data are: high speed arterial blood flow; turbulent flow in the feeding artery; changes in arterial flow pattern; decreased or reversed flow in the portal branch; arterio-portal or arterio-venous shunts; neovascularization in the tumor; compression, displacement and infiltration of blood vessels. Quantitative measurements by Doppler US in portal hypertension indicate that the cross-sectional area is enlarged and the portal blood flow velocity is decreased. Collateral blood flow usually indicates a turbulent flow. A classification of portal hypertension can be done using Doppler-US, according to the existing site of elevated vascular resistance: pre-sinusoidal, sinusoidal and post-sinusoidal. The first type is represented by extra-hepatic portal vein obstruction. Typical case of second type is cirrhosis of the liver caused by alcoholic or viral hepatitis. Budd-Chiari syndrome is a typical case of the third type.

Blood Flow Velocity↗

Use of proton nuclear magnetic resonance spectroscopy of plasma in screening for malignant disease.

In 1986, narrow plasma proton nuclear magnetic resonance (NMR) methyl and methylene line widths were reported to be associated with malignant disease, but more recent studies have not confirmed this relationship. The authors analyzed 106 plasma samples from healthy control subjects and patients with cirrhosis, hepatocellular carcinoma, metastatic liver tumors, other untreated cancers, and hyperlipidemia. NMR spectroscopy was performed using a proton NMR spectrometer operating at 399.65 MHz. A significant difference was found between the mean line widths of the plasma methyl resonances in control subjects and those in patients with cancer or hyperlipidemia. However, no significant difference was found between the mean plasma methylene line widths in control subjects and patients with cancer. Plasma samples from patients with liver disease or hyperlipidemia showed a characteristic methylene spectral pattern. The methylene pattern could be separated into three types: type A had a small peak on the right shoulder of the main peak; type B was a sharp single peak; and type C was a broad single peak. All control subjects had type A pattern; patients with liver disease had type C pattern; and patients who had hyperlipidemia had type B pattern, and hyperlipidemia may affect methyl and methylene line widths in NMR spectra. Because the methyl and methylene levels and their average line widths correlated inversely with triglyceride levels, considering the spectral patterns that indicate hyperlipidemia should decrease false-positive results and make the methyl line width useful for cancer screening.

Adult↗

The introduction of microvascular surgery to hepatic artery reconstruction in living-donor liver transplantation--its surgical advantages compared with conventional procedures.

Microvascular surgery for the reconstruction of the graft artery has been used since the 8th case in our series of 14 liver transplantations using living-related donors, and the clinical results have been compared between the first seven cases (the Loupe group) and the last seven cases (the Micro group). Seven arteries in 7 grafts were reconstructed with the use of loupe magnification in the Loupe group, while 8 arteries in 7 grafts were anastomosed with microscopic techniques in the Micro group. Statistically, there was no difference between the two groups in general background, including age, body weight and primary disease of the recipient, and in medical and surgical factors possibly relating to postoperative thrombosis of the hepatic artery. In two cases in the Loupe group, one or two additional reconstructions were necessary to obtain sufficient blood flow, while 8 arteries were anastomosed in the Micro group without any arterial complication in the postoperative period. There was no difference in time required for completing the arterial reconstruction (45.1 +/- 18.1 min in the Loupe versus 44.4 +/- 6.9 min in the Micro [mean +/- SEM]). Postoperative ultrasonic Doppler duplex study demonstrated a temporary decrease in the arterial flow in 2 cases of the Loupe group, and partial thrombosis of the artery was suspected. Additionally there were two episodes of hepatic artery thrombosis in 1 case of the Loupe group, in which emergent revision for thrombectomy and reanastomosis was performed at the first episode. This illustrated the higher incidence of arterial complications in the Loupe group compared with the Micro group (4 episodes/7 arteries in the Loupe versus 0/8 arteries in the Micro, P less than 0.05). In the present series there were no graft failures or arterial complications in the three deaths in the series. The clinical improvements achieved by microvascular surgery in living-donor liver transplantation suggest an alternative technical strategy for dealing with problematic arterial reconstruction in adult liver transplantation.

Child↗

Photodynamic therapy using pheophorbide-a and Q-switched Nd:YAG laser on implanted human hepatocellular carcinoma.

To evaluate whether administration of pheophorbide-a, a new photosensitizer, followed by use of Q-switched Nd:YAG laser produces a photodynamic reaction, we administered pheophorbide-a to female nude mice (BALB/c-nu) that had been implanted with human hepatocellular carcinoma. Intra-tumoral concentrations of pheophorbide-a were measured by high-performance liquid chromatography. 3 hours after peroral administration of 1 mg/kg body weight, the intra-tumoral concentration was too low to reveal photodynamic effects. Peroral administration of 250 mg/kg body weight, intra-peritoneal administration of 5 mg/kg body weight, and intra-tumoral injection of 200 micrograms yielded 0.24 micrograms/g, 0.83 micrograms/g and 3.68-108 micrograms/g tumor concentrations, respectively. All tumors were irradiated interstitially using a Q-switched Nd:YAG laser at 1064 nm. Only tumors that had been intra-tumorally injected had areas of necrosis larger than those in control tumors. The results suggest that the injection of pheophorbide-a followed by interstitial irradiation using a Q-switched Nd:YAG laser does not induce sufficient photodynamic reaction if the intra-tumoral pheophorbide-a concentration is less than 0.83 micrograms/g tumor tissue, and that photodynamic therapy may be useful if the pheophorbide-a tumor concentration is within the range of 0.83-108 micrograms/g.

Animals↗

Changes in portal blood flow consequent to partial hepatectomy: Doppler estimation.

Hemodynamic changes in portal blood flow were investigated in 56 patients with hepatic tumors who underwent partial hepatectomy. Portal flow was measured with a Doppler ultrasound system before, during, and after surgery. The portal flow of patients who underwent massive hepatectomy decreased intraoperatively. The portal flow per unit of cardiac output decreased in patients who underwent massive or major hepatectomy, patients with a cirrhotic liver, and patients who had a satisfactory postoperative course. Postoperatively, the portal flow in patients with a poor clinical outcome (multiple organ failure, hepatic failure, and cardiorespiratory failure) decreased significantly. Monitoring portal hemodynamic values appears to be useful in providing an index of "hepatic functional reserve." Adequate portal flow is essential for postoperative hepatic regeneration; changes in portal hemodynamic values may be directly related to the patient's ability to survive surgery and to regain or maintain normal liver function.

Adult↗

Relationship between esophageal varices and azygos vein evaluated by cineportography.

The relationship between esophageal varices and the azygos vein, which is generally considered to drain the major part of the variceal blood flow, was evaluated by percutaneous transhepatic cineportography in 35 patients with portal hypertension. We classified the patients into three groups. Those patients in whom most of the variceal blood drained into the azygos vein were designated the azygos-type group (n = 18). Those in whom most of the blood flowed into the brachiocephalic venous system were defined as the cervical-type group (n = 5), and those in whom the varices were drained by both the azygos vein and the brachiocephalic venous system were called the combined-type group (n = 12). Highly developed esophageal varices were recognized endoscopically in all patients in the combined-type and cervical-type groups, whereas some of the patients in the azygos-type group had less well-developed varices. In the azygos-type group, a tendency for the varices to be more severe as their drainage into the azygos vein became more cephalad was noted. Evaluation of the drainage of esophageal varices was considered useful not only for obtaining full comprehension of the significance of the azygos vein but also for assessing the suitability for sclerotherapy. Percutaneous transhepatic cineportography was useful for this purpose because it enables visualization of even the most minute amounts of blood flow.

Adult↗

[Evaluation of photodynamic therapy using pheophorbide-a as a photosensitizer].

Intra-tumoral concentrations of pheophorbide-a, a new photosensitizer, were measured by high-performance liquid chromatography after administration of pheophorbide-a to nude mice (BALB/c-nu) that had been implanted with human hepatocellular carcinoma. The results were as follows: 1) 0.009 +/- 0.007 microgram/g tissue in 1 mg/kg body p.o. administration group, 2) 0.22 +/- 0.06 microgram/g tissue in 250 mg/kg body p.o. administration group, 3) 0.85 +/- 0.14 microgram/g tissue in 5 mg/kg body intra-peritoneal administration group, 4) 3.42 +/- 2.84 microgram/g tissue in not-injected side, and 116 +/- 24 microgram/g tissue in injected side of 200 micrograms intra-tumoral administration group. Tumors in each group were irradiated using an Nd:YAG laser (Q-switch; mean power 0.5 W, duration 10 min.). Areas of tumor necrosis were larger than in the control group only in the intra-tumoral administration group. These results suggest that no photodynamic reaction occurs if the intra-tumoral pheophorbide-a concentration is less than 0.85 microgram/g tissue.

Animals↗

[Evaluation of the efficacy of photodynamic therapy on experimental hepatocellular carcinoma--using local injection of photosensitizer].

The effect on photodynamic therapy (PDT) of using pheophorbide-a as a photosensitizer and Nd: YAG laser (Q-switch) was evaluated. Two hundred micrograms (0.1 ml) of pheophorbide-a was injected into tumors that had been subcutaneously implanted into the backs of nude mice (BALB/c-nu). Interstitial Nd: YAG laser irradiation (Q-switch; mean power 0.5 W, duration 10 min.) was performed 72 hours after pheophorbide-a injection. Forty-eight hours after laser irradiation, the areas of tumor necrosis were measured; these were larger in the group with the injection of pheophorbide-a than in those without. The areas of tumor necrosis after Nd: YAG laser irradiation at a higher mean power (Q-switch; mean power 2 W, control temperature 43-43.5 degrees C, duration 10 min.) were also measured. Again, the areas were larger in the group injected with pheophorbide-a. These results show that the injection of pheophorbide-a and interstitial irradiation using Nd: YAG laser induce a photodynamic reaction, and that this combination is useful in the treatment of deep-seated tumors.

Animals↗

Truncoumbilical bypass of the portal vein in radical resection of biliary tract tumour involving the hepatic duct confluence.

Before combined resection of the right hepatic lobe and the hepatoduodenal ligament, an autogenous external iliac vein was interposed between the root of the portal vein trunk and the umbilical portion of the vein in four patients with biliary tract tumour. The left hepatic arterial pathway was preserved, except in one case in whom resection of this artery was followed by reconstruction. This procedure allowed successful and safe extended right hepatic lobe resection and combined en bloc resection of the hepatoduodenal ligament while preserving hepatic blood perfusion.

Adenoma, Bile Duct↗

Relationship between splenic and superior mesenteric venous circulation.

We took advantage of routine hemodynamic examinations to determine the relationship between splenic and intestinal circulation by infusing prostaglandin E1 into the superior mesenteric artery and observing the portal hemodynamic changes in patients with chronic liver disease. Relative blood flow rate in various vessels of the portal system were measured percutaneously using an ultrasonic duplex system, while portal venous pressure was measured directly using a transducer. The superior mesenteric venous blood flow increased significantly as did the portal venous blood flow and pressure, though the degree of change of portal venous blood flow was less than was expected from the change of portal venous blood flow in the superior mesenteric venous blood flow. Splenic venous blood flow decreased significantly. This decrease is perhaps due to a mechanism that acts to compensate for the increase induced in the superior mesenteric venous blood flow to maintain portal flow at approximately the same level. The measured changes suggest a relationship between splenic and intestinal blood flows that is regulated according to the hepatic circulatory condition. The regulatory mechanism should be considered when designing the treatment of portal hypertension.

Alprostadil↗

Observer variability in echo-Doppler measurements of portal flow in cirrhotic patients and normal volunteers.

The intraobserver and interobserver variability in measuring the portal vein flow by the echo-Doppler technique was evaluated in a blind controlled study. A total of 22 cirrhotic patients and 14 normal volunteers were examined by two skilled operators using duplex Doppler within a period of 1-3 mo (6 cirrhotics and 7 normal volunteers by both observers). Area, mean velocity, and flow were measured (4 measurements: A, B on day 1; C, D on day 2). The intraclass correlation coefficient was used to assess both the statistical and clinical significance of intraobserver and interobserver agreement for the measurements of these three parameters. The level of intraobserver agreement for each parameter on normal subjects and cirrhotics was obtained from the two measurements on the same day and from the two measurements at the same time on consecutive days. Overall agreement between the four measurements was also calculated. Levels of interobserver agreement were obtained by calculating separately the intraclass correlation coefficient from each of the four pairs by measurements made on the same subject by the two observers over the same period of 2 days. The coefficient of variation was also used to compare the variability in these measurements. Overall, intraobserver agreement on normal subjects varied from good to excellent for observer 1, and from fair to good for observer 2. On cirrhotic patients, observer 1 was excellent at all times for all parameters. Observer 2 had lower intraclass correlation coefficient values, especially for velocity on consecutive days. For the best of the two observers on the portal flow, the coefficient of variation in cirrhotic patients ranged from 2%-30% with a mean +/- SEM of 12% +/- 4%. No acceptable interobserver agreement was found between the two observers in either of the two samples of subjects. These results support the use of this technique mainly for the determination of rapid and large changes in portal hemodynamics within a short period of time. The technique seems to have low precision in monitoring chronic changes in portal hemodynamics.

Adult↗

[1H-NMR studies of plasma from patients with liver diseases].

We examined the 1H-NMR spectra of the lipid region of human plasma according to the method of Fossel et al. as the specific blood test for cancer. The study group included 20 patients with hepatocellular carcinoma (HCC), 10 patients with liver cirrhosis (LC) and 10 normal controls (NC). We measured the linewidths of methyl and methylene resonances of lipoprotein lipids at a proton resonance frequency of 400 MHz using a JNM GX400 FT NMR spectrometer. The mean linewidth values and the standard deviation of methyl were as follows: 41.3 +/- 7.2 Hz (NC), 34.8 +/- 6.9 Hz (LC), 29.6 +/- 5.7 Hz (HCC). There was thus a significant difference between NC and HCC. On the other hand, there was no significant difference between the three groups in the case of methylene. Although the spectrum in the HCC and LC groups had a blunt head but narrow body, that of the NC group had a pointed head but wide body, and the linewidth values thus showed wide dispersion. This difference in spectral patterns between the two groups was characteristic. Linewidth values, however, did not correlate well with the laboratory data.

Adult↗