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Biomedical subjects

S Sugano

Publications and source records attributed to S Sugano.

At least 163 records · Page 9Linked to original sources
PubMed1994

Intrahepatic arteriovenous shunting due to hepatocellular carcinoma and cirrhosis, and its change by transcatheter arterial embolization.

OBJECTIVES: To investigate intrahepatic arteriovenous shunt rate due to cirrhosis and hepatocellular carcinoma (HCC), complicated by cirrhosis, and its change after transcatheter arterial embolization. METHODS: The shunt rate was measured by hepatic artery infusion of labeled macroaggregated albumin. Counts were taken over the liver and both lungs for calculation of the shunt rate: cpm in lungs divided by (cpm in liver and lungs) x 100%. RESULTS: The intrahepatic arteriovenous shunt rate of cirrhosis ranged from 6.8% to 16.6% (12.6% +/- 3.4%, mean +/- SD). In HCC, it ranged from 7.2% to 27.1% (16.0% +/- 4.9%, mean +/- SD). The difference between the groups was statistically significant (p < 0.05). When the liver was more than 20% replaced by tumor, the intrahepatic arteriovenous shunt rate was higher than when less than 20% occupied (n = 6, 20.1% +/- 4.8% vs. n = 15, 14.4% +/- 4.0%; p < 0.05). Although the former was significantly different from liver cirrhosis, the latter was not significantly different from the shunt rate observed in liver cirrhosis without HCC. After transcatheter arterial embolization, excluding one patient who developed a visible hepatofugal arterioportal shunt, the mean change in shunt rate between the effective treatment group (n = 9, -2.1% +/- 2.8%, mean +/- SD) and the ineffective treatment group (n = 5, 3.0% +/- 3.3%, mean +/- SD) was statistically significant (p < 0.05). CONCLUSIONS: We found that intrahepatic arteriovenous shunt rate more sensitively detects intrahepatic arteriovenous shunting due to HCC than does angiography alone. Measuring intrahepatic arteriovenous stunt rate may provide useful information regarding response to treatment.

Adult↗
PubMed1993

Noncardiac chest pain due to acute gastric anisakiasis.

This paper described the first confirmed case of acute anginalike chest pain caused by gastric anisakiasis. A 55-year-old male, with a history of a sudden onset of chest pain and also a history of eating raw mackerel and tuna 9 hr prior to the onset of chest pain, was found upon endoscopy to have an imbedded parasite in the mucosal lining of his stomach. The chest pain disappeared after the endoscopic removal of larva. Endoscopy is highly recommended at the earliest possible time for patients who are suspected to have acute gastric anisakiasis.

Acute Disease↗
PubMed1993

Antihypertensive effects of peptides in autolysate of bonito bowels on spontaneously hypertensive rats.

An autolysate of bonito bowels was treated with ultrafiltration, loose RO concentration, ion-exchange chromatography, and reverse phase chromatography to increase its potency to inhibit angiotensin I-converting enzyme (ACE) activity by 16-fold. Oral administration of the partially purified autolysate decreased the systolic blood pressure of spontaneously hypertensive rats (SHR) in a dose-dependent manner at the doses of 1 g peptides/kg or higher. The relationship between the antihypertensive activity (in vivo) of the partially purified preparation and its ACE inhibitory activity (in vitro) in comparison with previously reported ACE inhibitory peptides is discussed.

Amino Acid Sequence↗
PubMed1993

Studies on the autonomic nervous function in Tsukuba emotional rats--with special reference to their cardiac function.

Autonomic nervous function in Tsukuba high (THE) and low (TLE) emotional rats as well as Wistar rats (control) was studied by means of electrocardiographical examination in addition to the runway test. In the runway test, locomotive activity differed significantly among the three strains, the greatest activity in TLE and the smallest in THE. Electrocardiogram (ECG) and locomotive activity were successively recorded for 24 hr using a small size of telemeter system. Though the locomotive activity showed a clear nocturnal rhythm, no significant difference was observed among the three strains. The mean value of R-R intervals in THE tended to be smaller than those in other two strains; showing a significant difference between THE and TLE. The mean value of standard deviation (SD) of R-R intervals in TLE tended to be larger than those in other two strains; showing a significant difference between TLE and Wistar in the light and dark periods, and also between TLE and THE in the light period. As regards coefficients of variation of R-R intervals (CV), there was no significant difference among the three strains. Autonomic nervous tone in THE and TLE was evaluated by means of autonomic blockades using atropine and/or propranolol. The sympathetic nervous tone represented 21.6% in THE and 16.8% in TLE, while the parasympathetic nervous tone -9.0% and -12.3% in THE and TLE, respectively. There was a significant difference in the net autonomic nervous tone between THE (10.7%) and TLE (-6.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The disturbance of water-maze task performance in mice with EMC-D virus infection.

The present study was performed to examine the influence of EMC-D virus on water-maze task performance in DBA/2 mice inoculated with 10(3) PFU/ml and BALB/c mice inoculated with 10(5) PFU/ml of EMC-D virus. In both strains, the latency to accomplish the task was shortened during successive 8 days of testing. However, the shortening of latency in the inoculated group was significantly smaller than that in the control group. Pathological studies showed that in both studies St. pyramidale hippocampi was commonly degenerated, but the degeneration of the spinal cord was shown only in DBA/2 mice. Therefore, the disturbance of water-maze task performance in mice infected with EMC-D virus might be partially due to the dysfunction of memory for working process or cognition of orientation other than underlying decreased ability in locomotion.

Animals↗
PubMed1993

[Diurnal fluctuations of heart rate and locomotive activity in the vole (Microtus arvalis)].

Diurnal fluctuations of heart rate and locomotive activity were observed in the unanesthetized and unrestrained voles (Microtus arvalis) and mice, and the differences in these biological characters between voles and mice were also investigated. The mean heart rate of vole in whole day was lower than that of mice. In voles, there were no significant differences in the mean heart rate between in light period and in dark period. It was observed that most of voles were active in not only dark period but light period. On the other hand, in mice, the mean heart rate in dark period was significantly higher than that in light period, and the nocturnal habit was shown obviously in the locomotive activity. In voles, the ultradian rhythmicities of 95-210 min in the heart rate and those of 160-210 min in the locomotive activity were recognized, and the fluctuations of heart rate due to ultradian rhythmicity in voles exceeded the difference between the heart rate in light period and that in dark period. In mice, one of three animals showed the ultradian rhythmicity of 85 min in the fluctuation of heart rate. Diurnal fluctuation of the heart rate in voles consisted of the two patterns which the peaks of heart rate were coincident with the active period or the resting period. However, all the peaks of heart rate in mice were coincident with the active period. These results suggested that the fluctuations of heart rate in voles were dependent on ultradian rhythmicities in addition to the circadian rhythmicities.

Animals↗
PubMed1993

Immunohistochemical study and an electron microscopic observation of the nucleus of the optic tract in the rat.

In the present study, gamma aminobutyric acid (GABA)-positive cells and terminals were detected in the nucleus of the optic tract (NOT) in the rat. However, GABA-positive cells in the NOT receiving projections directly from retinal ganglion cells could not be identified. To determine the role of GABA in the projection from the retinal ganglion cells to the NOT, we used electron microscopy to observe this nucleus of a rat in which one eyeball had been removed. In the nerve synapse binding region of the NOT on the side opposite to the enucleated eyeball, the symmetrical and asymmetrical types were recognized; the ratio between the two was the same as before the eyeball was enucleated. From these results, we conclude that the inhibitory axon terminals in the NOT do not have GABA activity. The GABA-positive cells seem to act indirectly as intrinsic interneurons, when processing or transmitting the information from the retina to the inferior olivary nucleus.

Animals↗
PubMed1993

Oral administration of peptides derived from bonito bowels decreases blood pressure in spontaneously hypertensive rats by inhibiting angiotensin converting enzyme.

1. Peptides C111 (Gly-Val-Tyr-Pro-His-Lys) and C112 (Ile-Arg-Pro-Val-Gln), extracted from the autolysis product of bonito liver and intestine, have been shown to inhibit angiotensin converting enzyme (ACE) activity in vitro with IC50s of 1.6 microM and 1.4 microM, respectively. We examined the effects of oral administration of these peptides on blood pressure. 2. Oral administration of these peptides (500 mg kg-1 body weight each) inhibited the pressor effect of intravenously administered angiotensin I in Sprague-Dawley rats. 3. In spontaneously hypertensive rats, oral administration of these peptides (100-200 mg kg-1 body weight) showed depressor effects. 4. These results suggest that the peptides, C111 and C112, are orally effective ACE inhibitors with hypotensive effect.

Administration, Oral↗
PubMed1993

Studies on the relationship between hepatic and splenic density change in dynamic CT in the presence of a large splenorenal shunt in patients with liver cirrhosis.

Using dynamic computerized tomography (CT), we studied liver and spleen hemodynamics in one group of patients with a large splenorenal shunt and another group without a large shunt. Specifically, we measured the time-to-peak hepatic and splenic enhancement and the loss of enhancement, i.e., decay time. The time-to-peak liver enhancement (61 +/- 21 s vs. 81 +/- 14 s, p < 0.05) and the splenic decay time (24 +/- 16 s vs. 48 +/- 28 s, p < 0.05) were significantly shorter in patients with a large splenorenal shunt compared to those without. The groups had similar hepatic decay times and times to peak splenic enhancement. We found dynamic CT useful in assessing the effect of a large splenorenal shunt on portal and splenic hemodynamics.

Adult↗
PubMed1992

Use of an epitope-tagged cDNA library to isolate cDNAs encoding proteins with nuclear localization potential.

We have combined epitope tagging with an expression cDNA library in order to isolate cDNAs encoding nuclear proteins. This system allows us to detect proteins expressed from the cDNA library by using antibodies against the epitope tag. As a tag, we used the 85-aa N-terminal peptide of the SV40 T antigen which lacks the nuclear localization signal (NLS). A strong expression vector, pEF204 [Kim et al., Gene 91 (1990) 217-223], was modified into an epitope-tagging vector, pTkim, by putting the tag-coding region and a cDNA cloning site immediately after its promoter. From cDNA libraries constructed using pTkim, we isolated eight cDNA clones whose tagged proteins were localized within the nuclei. From partial sequence analysis, two cDNAs were shown to code for the ribosomal (r-) proteins, simian L44 and human L21, and the others were shown to be new. Furthermore, six cDNAs including those encoding the r-proteins could direct a non-karyophilic T antigen [Fischer-Fantuzzi et al., Virology 153 (1986) 87-95] into nuclei, showing that they have NLSs. These results indicate that this system is useful for isolating new cDNAs which code for nuclear proteins.

Animals↗
PubMed1992

Evaluation of hepatic density change by dynamic CT in healthy humans and in patients with chronic liver diseases.

Dynamic computed tomography using 0.4 ml/kg of 65% meglumine diatrizoate was performed to estimate pharmacokinetics of contrast media in the liver in healthy controls (N = 11), in patients with chronic viral hepatitis (N = 17), posthepatic liver cirrhosis (N = 21), and alcoholic liver cirrhosis (N = 23). The time of peak enhancement (the time interval between peak aortic and liver enhancement) was significantly different between each group. Alcoholic liver cirrhosis was the most prolonged, followed by posthepatic liver cirrhosis, chronic viral hepatitis, and finally controls. A peak enhancement time of 28 sec had a diagnostic accuracy of 97% for chronic liver diseases. A time greater than 44 sec had a diagnostic accuracy for cirrhosis of 96%. The decay time (the time from peak enhancement of the liver to the curve's center of gravity) was also significantly different between each group. Again, alcoholic liver cirrhosis was the longest, followed by posthepatic liver cirrhosis, chronic viral hepatitis, and then the controls. Dynamic computed tomography has many potential applications in studying intrahepatic physiologic events and may contain diagnostic information for chronic liver diseases.

Adult↗
PubMed1992

Endotoxin levels in cirrhotic rats with sterile and infected ascites.

Endotoxin levels were measured in sterile and bacterially infected ascites in a rat model of phenobarbital and carbon tetrachloride induced cirrhosis was used. An improved chromogenic substrate assay was used to measure endotoxin. All rat ascites specimens were positive for endotoxin. In culture-negative ascites (n = 8), it ranged from 0.05 EU/ml to 0.14 EU/ml (0.08 +/- 0.04 EU/ml, mean +/- SD) (Escherichia coli 0111:B4 endotoxin was used as a reference). In culture-positive ascites (premortem n = 3, postmortem n = 1), it ranged from 0.78 EU/ml to 1.8 EU/ml (1.29 +/- 0.59 EU/ml, mean +/- SD). All rats with premortem culture-positive ascites died within two days. This model is useful to study ascites endotoxin levels. In this study, increasing levels of ascites endotoxin correlated with spontaneous bacterial peritonitis and death.

Animals↗
PubMed1992

ECG changes under hyperkalemia with nephrectomy in the rat.

Electrolyte abnormalities have become an increasingly important cause of arrhythmias. Although the electrocardiographic (ECG) changes under hyperkalemia in the rat are poorly understood, it is conceivable that excess plasma potassium may also alter the cardiac excitations in the rat. Further, effects of hyperkalemia on ECG in the rat may differ from other species that have ST-segment and longer QT intervals in ECG. The present study was designed to determine the diagnostic criteria for ECG manifestations to various levels of plasma potassium concentration. For this purpose, hyperkalemia was induced by nephrectomy with and without infusions. Because it was difficult to produce various levels of plasma potassium concentration by only nephrectomy, we used two kinds of infusions to obtain especially moderate levels of nephrectomy-induced hyperkalemia. ECGs were recorded 24, 36, and 48 hours after nephrectomy. Plasma potassium concentration and number of abnormal ECGs were increased time-dependently. Increased T wave amplitude was present with mild hyperkalemia. The typical T wave change observed with so-called sinoventricular conduction levels of potassium concentration in species with long QT intervals did not occur in the rat. PR interval and QRS duration became slightly shorter within moderate hyperkalemia. P wave disappeared in most rats at potassium levels above 8.0 mEq/l. In advanced hyperkalemia (plasma potassium concentration above 7.5 mEq/l), conduction in all parts of the heart was suppressed. Moreover, sinoventricular conduction appeared. Thus, the diagnostic criteria for ECG manifestations to various levels of plasma potassium concentration in the rat were demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Inactivation of Bacillus subtilis glutamine synthetase by metal-catalyzed oxidation.

Instability of Bacillus subtilis glutamine synthetase in crude extracts was attributed to site-specific oxidation by a mixed-function oxidation, and not to limited proteolysis by intracellular serine proteases (ISP). The crude extract from B. subtilis KN2, which is deficient in three intracellular proteases, inactivated glutamine synthetase similarly to the wild-type strain extract. To understand the structural basis of the functional change, oxidative modification of B. subtilis glutamine synthetase was studied utilizing a model system consisting of ascorbate, oxygen, and iron salts. The inactivation reaction appeared to be first order with respect to the concentration of unmodified enzyme. The loss of catalytic activity was proportional to the weakening of subunit interactions. B. subtilis glutamine synthetase was protected from oxidative modification by either 5 mM Mn2+ or 5 mM Mn2+ plus 5 mM ATP, but not by Mg2+. The CD-spectra and electron microscopic data showed that oxidative modification induced relatively subtle changes in the dodecameric enzyme molecules, but did not denature the protein. These limited changes are consistent with a site-specific free radical mechanism occurring at the metal binding site of the enzyme. Analytical data of the inactivated enzyme showed that loss of catalytic activity occurred faster than the appearance of carbonyl groups in amino acid side chains of the protein. In B. subtilis glutamine synthetase, the catalytic activity was highly sensitive to minute deviations of conformation in the dodecameric molecules and these subtle changes in the molecules could be regarded as markers for susceptibility to proteolysis.

Bacillus subtilis↗
PubMed1992

Adenovirus E1A proteins stimulate inositol phospholipid metabolism in PC12 cells.

To study the influence of nuclear oncogenes on inositol phospholipid metabolism, we examined the various parameters of inositol phospholipid metabolism in PC12 cells expressing adenovirus type 12 or adenovirus type 5 E1A. Although the inositol 1,4,5-trisphosphate content was increased only slightly, the diacylglycerol content was 2.4-fold higher in E1A-expressing PC12 cells. Furthermore, we found that the activity of phospholipase C, one of the key enzymes in inositol phospholipid metabolism, was increased at least five- to eightfold. Diacylglycerol kinase activity in the membrane fraction was 10 to 15% of that in parental PC12 cells. Overall protein kinase C activities in E1A-expressing PC12 cells were decreased, but the activity of membrane-bound protein kinase C was significantly increased. These observations clearly indicate that inositol phospholipid metabolism is stimulated in cells producing E1A and suggest that nuclear oncogene E1A has the ability to stimulate inositol phospholipid metabolism.

1-Phosphatidylinositol 4-Kinase↗
PubMed1992

Immunohistochemical study of c-erbB-2 oncoprotein overexpression in human major salivary gland carcinoma: an indicator of aggressiveness.

In order to analyze the correlation between immunohistochemical positivity for c-erbB-2 oncoprotein and prognosis in patients with malignant salivary gland tumors, 59 cases of malignant tumors of the major salivary glands, including 35 parotid gland, 20 submaxillary gland and 4 sublingual gland tumors, were studied immunohistochemically using a polyclonal antibody against c-erbB-2 oncoprotein. Positive staining was observed in 13 (22%) of the 59 cases. Interestingly, positive results were obtained only in adenocarcinoma (6/20) and carcinoma in pleomorphic adenoma (7/15), and not in any other histological types such as adenoid cystic carcinoma, mucoepidermoid tumor, and squamous cell carcinoma. There was no correlation between the degree of differentiation of adenocarcinoma and c-erbB-2 positivity. Since the carcinoma in pleomorphic adenoma positive for c-erbB-2 oncoprotein was adenocarcinoma, adenocarcinoma and adenocarcinoma in pleomorphic adenoma were placed together (n = 33), and the presence or absence of c-erbB-2 oncoprotein in this group was examined for correlation with patients' survival and other clinicopathological features, including clinical stage, tumor size, surgical margins, and lymph node status. The c-erbB-2-positive tumors tended to be more advanced and larger than negative tumors. Similarly, c-erbB-2-positive tumors were difficult to resect completely, were associated with lymph node metastasis more frequently, and showed lower disease-free survival than negative cases (P less than .05). We conclude that immunohistochemical positivity for c-erbB-2 is an indicator of aggressiveness in both adenocarcinoma and adenocarcinoma in pleomorphic adenoma of the major salivary glands.

Adenocarcinoma↗