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Biomedical subjects

K Ando

Publications and source records attributed to K Ando.

At least 19 recordsLinked to original sources
PubMed1992

[MR imaging of bone metastasis].

One hundred and three patients with known malignancy and suspected bone metastasis underwent magnetic resonance imaging. In 93%, the metastatic lesions, detected both on plain films and radionuclide bone scans, showed decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted images. All lesions, except one lesion showing much blastic change on plain films, showed contrast enhancement with Gd-DTPA administration. Although further investigation is needed, a correlation between the type of primary malignancy and the signal intensity of the metastatic lesion is suggested. Among 312 metastatic lesions detected by MR imaging, 272 lesions (87%) and 134 lesions (40%) were also detected by radionuclide bone scans and plain films, respectively. In five cases, MR imaging clearly revealed the lesion compressing the spinal cord, which helped us formulate a therapeutic plan. We conclude that MR imaging is the most sensitive examination for detecting bone metastasis and is necessary for planning treatment.

Bone Neoplasms↗
PubMed1992

Insulin inhibits norepinephrine overflow from peripheral sympathetic nerve ending.

The effects of insulin on peripheral nervous system are unknown. We therefore studied the effects of insulin on sympathetic nerve activity in isolated mesenteric arteries of Sprague-Dawley rats. The overflow of norepinephrine (NE) by electrical stimulation was used as the index of sympathetic nervous system activity. Insulin (0.5 to 1U/l) decreased the NE release in a dose-dependent fashion. This inhibitory effect was, however, reversed by either 5 x 10(-5)M cocaine or 5 x 10(-4)M ouabain treatment. Thus, we postulate that insulin attenuates NE overflow from peripheral sympathetic nerve endings, probably due to enhanced NE reuptake.

Animals↗
PubMed1992

Antigenic determinants of senescent antigen of human erythrocytes are located in sialylated carbohydrate chains of Band 3 glycoprotein.

Naturally occurring IgG autoantibody against Band 3 glycoprotein of human erythrocyte membrane (anti-Band 3) recognizes the erythrocytes modified with oxidizing or SH-blocking agents as well as senescent erythrocytes. Location of the antigenic determinants of Band 3 this autoantibody recognizes was investigated by competitive inhibition studies of the antibody binding to the modified cells. Autologous IgG binds to the modified erythrocytes, and purified Band 3 totally inhibits the binding. This inhibitory activity of Band 3 was not affected by digestion of Band 3 with various proteases. Treatment of Band 3 with endo-beta-galactosidase that destroys the poly-N-acetyllactosaminyl sugar chain of Band 3 or with neuraminidase resulted in loss of the inhibitory activity. Oligosaccharides released from Band 3 by hydrazinolysis effectively inhibited the binding of autologous IgG and 125I-labeled purified anti-Band 3 to the modified cells, whereas the oligosaccharides depleted of acidic components did not. Endo-beta-galactosidase and neuraminidase destroyed the activity of the oligosaccharides, but alpha-L-fucosidase did not. Furthermore, human lactoferrin that contains sialylated two N-acetyllactosaminyl units also exhibited potent inhibitory activity, and the activity was destroyed by endo-beta-galactosidase and neuraminidase. These results indicate that the antigenic determinants of Band 3 are located in sialylated poly-N-acetyllactosaminyl sugar chains. Based on this finding, mechanism of appearance of the antigen on senescent erythrocytes recognized by anti-Band 3 (senescent antigen) was discussed.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1992

[Protective effect of prostaglandin E2 on cerulein-induced rat pancreatitis].

In order to clarify the effect of prostaglandin E2 (PGE2) on cerulein-induced rat pancreatitis, we investigated the interaction of PGE2 with cerulein or secretin. Intravenous infusion of 10 micrograms/kg.h cerulein inhibited external secretion of the pancreas from one hour and caused macroscopic edema at 3 hours. Administration of PGE2 relieved the inhibitory effect of supramaximal dose of cerulein and decreased the pancreatic edema. The 100 micrograms/kg.hr PGE2 had no significant effect on the pancreatic juice volume and amylase secretion stimulated with 0.2 micrograms/kg.hr of cerulein. Intravenous injection of 100 micrograms/kg PGE2 inhibited both the volume and amylase secretion of pancreatic juice stimulated with 1 U/kg.h of secretin. The protective effect of PGE2 on cerulein-induced pancreatitis was not the stimulation on secretion but caused the cytoprotective effect of PG such as stabilization of cytoplasmic and lysosomal membrane.

Acute Disease↗
PubMed1992

Alleviation of intestinal lesions by combined treatment with a 5-fluoro-2'-deoxyuridine (FUDR) derivative and alpha-difluoromethylornithine (DFMO)[correction of DMFO] in tumor-bearing mice.

alpha-Difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, reduced intestinal lesions in tumor-bearing mice caused by treatment with N3-(3-methylbenzoyl)-3',5'-diacetyl [corrected]-FUDR (FF-705), a derivative of 5-fluoro-2'-deoxyuridine (FUDR). FF-705 at 32 mg/kg (the effective dose) suppressed tumor growth to about 40% of the control level. At this dose, body weight gain was suppressed slightly when FF-705 was given alone, and this change was milder in the DFMO-supplemented group. Intestinal lesions were suppressed almost completely by concomitant treatment with DFMO. The gross lesion index in the combined treatment group was similar to that in the controls and significantly smaller than in the FF-705-alone group (0.3 and 1.9, respectively). The histological lesion index in the combined treatment group was also significantly smaller than in the FF-705-alone group (7.9 and 23.8, respectively). When FF-705 was given at 64 mg/kg, the intestinal mucosal lesions were more severe, but DFMO supplementation reduced them by approximately 50%. Moreover, maltase and diamine oxidase activities of intestinal epithelium remained higher with combined treatment than with FF-705 alone. With FF-705 at 256 mg/kg (a toxic dose), DFMO had little protective effect against intestinal damage.

Amine Oxidase (Copper-Containing)↗
PubMed1992

Effect of 3-hour pancreatic duct obstruction on pancreatic lysosomal and digestive enzymes in rabbits.

We studied the effect of short-term (3 hours) pancreatic duct obstruction (PDO) on the exocrine pancreas and on the secretion of lysosomal enzymes into the pancreatic juice of rabbits during stimulation by pancreatic secretagogues. The following evaluations were made: serum amylase levels, pancreatic water content, pancreatic amylase, trypsinogen and cathepsin B content, and output of pancreatic enzymes and lysosomal hydrolases when stimulated by secretin and caerulein as well as the distribution of cathepsin B in subcellular fraction. PDO for 3 hours plus secretin infusion caused a significant rise in serum amylase levels, pancreatic water content, and pancreatic amylase and trypsinogen content due to congestion of digestive enzymes during PDO. There was also a redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction. In normal rabbits and in those with only secretin infusion, caerulein stimulated the secretion of cathepsin B, into pancreatic juice. Just after PDO, the secretion of cathepsin B, amylase and trypsinogen significantly decreased. By 24 hours after PDO, the output of cathepsin B stimulated by caerulein and secretin had increased significantly. Amylase and trypsinogen output were also significantly increased at this stage, in both the secretin and caerulein fractions. These results indicate that the secretion of lysosomal enzymes into pancreatic juice is stimulated by gut hormones, such as caerulein, in the normal physiological state and in pathological states, such as PDO. These results also show augmented secretion of both lysosomal enzymes and pancreatic digestive enzymes in the recovery stage after PDO and their important roles at this stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases↗
PubMed1992

Chemically induced forestomach papillomas in transgenic mice carry mutant human c-Ha-ras transgenes.

Forestomach papillomas and skin papillomas were induced very efficiently by a single dose administration of the chemical carcinogen methylnitrosourea (MNU) in transgenic mice (rasH2 line) carrying human hybrid c-Ha-ras genes, which encode the prototype p21 gene product. The incidence of forestomach papillomas was dose dependent; when 50 mg/kg of MNU were administered i.p., all of the transgenic mice (56 of 56) developed forestomach papillomas within 12 weeks after administration, whereas 5 and 0.5 mg/kg of MNU induced papillomas in 2 of 19 and 1 of 19 mice, respectively. Nine of 56 transgenic mice (16%) also developed skin papillomas at sites wounded by bites or scratches. Only 1 of 77 nontransgenic littermates developed forestomach papillomas after administration of 50 mg/kg of MNU, and no skin papillomas appeared within 12 weeks after MNU administration. The transgenes (integrated copy number, 5-6) in the tumors developed in 55 of 56 affected transgenic mice (98%) contained at least 1 copy of the transgene that was activated by somatic point mutation at the 12th codon, from GGC (Gly) to GAC (Asp). Because somatic point mutations at the 12th or 61st codon of transgenes have never been detected in normal tissues of transgenic mice thus far examined, these mutational activations of transgenes are tumor-specific events. RNA expression of these activated transgenes was also detected. From these results, it is suggested that somatic mutational activation of the human c-Ha-ras transgene plays a causative role in the occurrence of forestomach and skin papillomas induced by MNU administration in these transgenic mice. This transgenic mouse provides a unique screening system for chemicals that induce or suppress papillomagenesis.

Animals↗
PubMed1992

Increased production of endothelin-1 in patients with inflammatory arthritides.

OBJECTIVE: Endothelin-1 (ET-1) is a potent vasoconstrictive peptide, but its precise mechanism of action in vivo has remained unknown. METHODS: We measured ET-1 activity by radioimmunoassay, in both plasma and synovial fluid from patients with inflammatory arthritides. RESULTS: ET-1-like immunoreactivity was found in synovial fluid, at levels severalfold higher than those in plasma. Reverse-phase high-performance liquid chromatography showed an elution profile corresponding to actual ET-1. A single class of high-affinity binding sites for ET-1 in cultured synovial cells was also detected. Furthermore, ET-1 induced mild DNA synthesis in synovial cells. CONCLUSION: Taken together, these results indicate that ET-1 might contribute to the synovial proliferation seen in inflammatory arthritides, in an autocrine/paracrine manner.

Adult↗
PubMed1992

Direct surface cooling of the exocrine pancreas in the rat.

A study was carried out to evaluate the effects of direct cooling on the exocrine pancreas. Changes in amylase and cathepsin B release, and in the subcellular distribution of amylase and cathepsin B were measured after 1, 2 and 3 h of direct pancreatic cooling in rats. Cooling for 2 and 3 h caused significant hyperamylasaemia and increased pancreatic amylase content, but minimal histological change. Furthermore, 3 h of cooling caused marked redistribution of cathepsin B activity from the lysosomal fraction to the heavier zymogen fraction, and co-localization of lysosomal and digestive enzymes; amylase and cathepsin B output into pancreatic juice after caerulein stimulation were also reduced. These results show that direct pancreatic cooling impairs exocrine function and implicate lysosomal enzymes in the pathogenesis of pancreatic injury, in agreement with results from other models of experimental pancreatitis.

Amylases↗
PubMed1992

Effects of precocenes on vitellogenesis in the adult female tick, Ornithodoros moubata (Acari: Argasidae).

Vitellogenin (Vg) concentrations in the hemolymph and ovarian development were studied in Ornithodoros moubata after treatment with precocenes 1 (P1) and 2 (P2). Precocene was dissolved in acetone or DMSO and topically applied to the dorsal surface of ticks: (1) at adult ecdysis; (2) 24 h before engorgement; (3) immediately after engorgement; and (4) 24 h after engorgement. Subsequently, P1 and P2 were dissolved in olive oil and injected through the gonopore into the body cavity 24 h after engorgement. Vitellogenin concentration was measured on days 5 and 10 after engorgement and ovarian development was scored on day 10, 20 or 30. Oviposition was also recorded and the average weight of eggs laid by females was determined. No differences in concentration of Vg in the hemolymph occurred between the control ticks and ticks treated topically or by injection with P1 and P2. Precocene did not suppress the synthesis of Vg in O. moubata. However, oviposition was reduced in ticks that survived repeated treatment with high doses of P2 dissolved in acetone.

Animals↗
PubMed1992

Exploratory eye movements in schizophrenic patients and patients with frontal lobe lesions.

Exploratory eye movements in 20 schizophrenics, 18 patients with frontal lobe lesions (9 right-sided and 9 left-sided) and 20 normal controls were examined with an eye mark recorder while they viewed stationary S-shaped figures. The eye movements made during the subject's first 15-s viewing of an original figure were analyzed. Patients with right frontal lobe lesions (RF) and schizophrenics (S) had lower scores than normal controls (NC) for the number of eye fixations, total eye scanning length and mean eye scanning length. Each subject was then shown two other figures slightly different from the original and was requested to compare them with the original. After comparing them, the subject was asked the question, "Are there any other differences?" The eye movements made over the ensuing 5 s in response to this question were scored using the responsive search score (RSS). The RSS was low only in the S group. The subject was also asked to reproduce the original figure before and after making comparisons between the figures. The RF and S groups were poorer at reproduction than the NC group. These findings suggest that there is disordered function of the right frontal lobe in schizophrenia, and that schizophrenia is due not only to localized damage to one part of the brain but to more widespread damage.

Adult↗
PubMed1992

Vasodilating actions of calcitonin gene-related peptide in normal man: comparison with atrial natriuretic peptide.

To compare the vasodilator effect of calcitonin gene-related peptide (CGRP) with that of atrial natriuretic peptide (ANP), forearm blood flow (FBF) was measured by strain-gauge plethysmography during the continuous infusion of different doses of the peptides dissolved in 5% dextrose into the brachial artery in healthy subjects. Either CGRP or ANP increased FBF in a dose-dependent fashion. Although 100 ng/ml CGRP increased FBF from 3.27 +/- 0.41 to 10.70 +/- 1.77 ml/100 ml/min, the same dose of ANP increased FBF from 2.40 +/- 0.38 to 5.39 +/- 0.22 ml/100 ml/min, which was significantly lower than the increase in CGRP (p less than 0.01): Plasma concentration of peptides (on a molar basis) was positively correlated with FBF in CGRP (r = 0.820, p less than 0.01) or ANP (r = 0.722, p less than 0.01). However, the slope of the regression line between plasma level and FBF was significantly higher (p less than 0.01) in CGRP (12.88 +/- 0.99) than in ANP (2.10 +/- 0.27). Thus the vasodilator effect of CGRP was more potent than that of ANP. The present findings are compatible with functional involvement of CGRP in the regulation of forearm circulation.

Adult↗
PubMed1992

A new technique of hepatectomy using an occlusion balloon catheter for the hepatic vein.

To minimize intraoperative bleeding and allow more accurate resection, we have devised a new technique for hepatectomy. In addition to occlusion of the afferent vessels, we occlude the hepatic vein at the hepatocaval junction using a balloon catheter inserted transhepatically under intraoperative ultrasonic guidance. We have performed eight hepatectomies using this method. A sequence of 15 minutes of vascular occlusion followed by 5 minutes reperfusion was repeated throughout the operation, and the total ischemic time ranged from 45 to 90 minutes. This method greatly decreased intraoperative bleeding without causing significant elevation of the postoperative transaminase or lactic dehydrogenase levels when compared with occlusion of only the afferent vessels or nonischemic resection using a microwave tissue coagulator in patients undergoing equivalent resections. Also, the postoperative prothrombin time recovered to a significantly higher level, and there were no fatal postoperative complications using this method. Our method is useful for systematic hepatic resection along the hepatic vein or for resection of tumor sited at the confluence of the hepatic vein.

Aged↗
PubMed1992

Tumor necrosis factor-alpha induces vascular hyporesponsiveness in Sprague-Dawley rats.

The cytokine tumor necrosis factor-alpha (TNF alpha) is one of the major mediators of septic shock. Because vasodilation is a hallmark of sepsis and decreased vascular responsiveness has been implicated in the pathogenesis of septic shock, we studied the effect of TNF alpha on the mean blood pressure in conscious rats and vascular responsiveness to vasoconstrictors ex vivo using the standard organ bath method. Intravenous infusion of TNF alpha (0.006 or 0.06 mg/kg/hr for 10 hours) decreased mean blood pressure in a dose-dependent fashion. Contractile responses to norepinephrine were depressed dose-dependently in the aortic rings both with and without its endothelium. Aortic contractions by potassium depolarization were also depressed. These results suggest that TNF alpha induces non-specific vascular hyporesponsiveness, which is independent of the presence of the endothelium. The TNF alpha-induced vascular hyporesponsiveness might contribute to the hypotensive action of TNF alpha.

Analysis of Variance↗
PubMed1992

Effects of an antitussive mixture and its constituents in rats discriminating methamphetamine from saline.

The discriminative effects of over-the-counter antitussive syrup containing dihydrocodeine (DHC), methylephedrine (MEP), caffeine (CAF), and chlorpheniramine (CPA) were compared with those of methamphetamine (MA) in a drug discrimination experiment using rats. Rats were trained to discriminate the effects of MA at 0.5 mg/kg SC and saline for food reinforcement under the fixed-ratio 10 schedule in a two-lever operant chamber situation. In substitution testing using a cumulative dose procedure by the subcutaneous route, DHC (4 and 8 mg/kg, expressed hereafter as referred to cumulative dose) or CPA (16-64 mg/kg) individually did not produce MA lever selection. On the other hand, MEP (128 mg/kg) and CAF (64 mg/kg) produced MA lever selection 41.5 and 57.2% of the time, respectively. The complete mixture (16 mg/kg DHC + 32 mg/kg MEP + 33.2 mg/kg CAF + 6.4 mg/kg CPA) produced MA level selection 65.8% of the time. The partial mixture containing only MEP + CAF at the above doses produced MA lever selection 95.6% of the time. Thus, the complete mixture only partially substituted for MA in rats while the partial mixture containing MEP and CAF completely substituted for MA.

Animals↗
PubMed1992

Secretion of correctly processed and folded pancreatic secretory trypsin inhibitor by Bacillus subtilis.

We constructed a plasmid, designated pNPP126, containing a DNA sequence encoding a fusion protein composed of Bacillus amyloliquefaciens neutral protease prepeptide (signal peptide) and human pancreatic secretory trypsin inhibitor (hPSTI), where the mature hPSTI is accurately fused to the 3'-terminal of the prepeptide coding region. It was observed that the strain Bacillus subtilis MT600 harboring pNPP126 could secrete a trypsin inhibitory activity into the culture medium. The N-terminal amino acid sequence, the amino acid composition and the stoichiometry of the purified hPSTI produced by B. subtilis were the same as those of natural hPSTI, indicating that the transformant B. subtilis MT600 (pNPP126) could efficiently secrete the correctly processed and folded hPSTI into the culture medium.

Bacillus subtilis↗
PubMed1992

Life cycle of Gnathostoma nipponicum Yamaguti, 1941.

The life cycle of Gnathostoma nipponicum was examined by field survey and by experimental infection of animals with the larvae. Naturally infected larval G. nipponicum were found in loaches, catfish, and snakes. Experimentally, loaches, killifishes, frogs, salamanders, mice, and rats were successfully infected with the early third-stage larvae of G. nipponicum obtained from copepods (the first intermediate host), whereas snakes, quails, and weasels were not. Frogs, snakes, quails, and rats were experimentally infected with the advanced third-stage larvae (AdL3) from loaches. These results reveal that some species of fishes, amphibians and mammals can act as the second intermediate host and that some species of reptiles, birds and mammals can act as a paratenic host. The life cycle was completed in weasels, the definitive host, which were infected with AdL3 from loaches and started to evacuate eggs of G. nipponicun in faeces on days 65-90 postinfection.

Animals↗