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M Tsuji

Publications and source records attributed to M Tsuji.

At least 217 records · Page 12Linked to original sources
PubMed1996

A genetic algorithm approach to optimization for the radiological worker allocation problem.

This paper describes a new approach to the radiological worker allocation problem using a multiple objective genetic algorithm. The worker allocation problem in radiological facilities involves various types of constraints and even mutually conflicting ones, such as individual dose limits, working time limits, etc. A major difficulty of this highly working time limits, etc. A major difficulty of this highly constrained problem is the way of finding an optimal solution in the huge search space where a large proportion of solutions are not feasible because some of the constraints cannot be satisfied. The paper proposes a model of evolution to establish an optimal assignment efficiently, based on the biological insights into the evolutionary process and heuristic ideas. The experimental results show a very rapid evolution to produce feasible solutions, and the application of multiple evaluation functions converges the feasible solutions to good ones. The genetic algorithm approach was found to be superior to the goal programming and simplex methods.

Algorithms↗
PubMed1996

Serological evaluation of soluble CD44 in renal cancer.

In this study, we examined the feasibility of using elevated serum CD44 concentration as an indicator in renal cancer. We performed enzyme-linked immunosorbent assays using 63 sera obtained from 47 patients with renal cancer and 16 healthy controls and evaluated the clinico-pathological parameters. The concentration of soluble CD44 standard (sCD44std), indicating the concentration of all circulating CD44 isoforms, was significantly higher in renal cancer patients than in normal individuals (745+/-170 ng/ml vs. 563+/-159 ng/ml, P=0.001). The concentration of soluble CD44 splice isoforms sharing exon v6 (sCD44v6) was also higher in the same patients (287+/-121 vs. 220+/-59, P=0.056). However, there were no correlations between the concentrations of sCD44std or sCD44v6 and clinico-pathological parameters such as grade, stage, histological type, tumor size and growth type. The ratio of sCD44std/sCD44v6 was higher in the rapid growth-type cancers than in the slow growth-type cancers (3.95+/-2.12 vs. 2.63+/-0.82, P = 0.014). These findings suggested that the serum concentration of unknown soluble CD44 isoforms not sharing exon v6, which are present in sCD44std, increases in patients with rapid growth-type cancers. These findings indicated that sCD44std and sCD44v6 are not useful indicators of tumor burden and metastasis in patients with renal cancer, but that an unknown sCD44 isoform(s) plays a role in the biological behavior of the rapid growth-type cancers.

Adolescent↗
PubMed1996

Phosphocreatine and creatine kinase in piglet cerebral gray and white matter in situ.

Rates of adenosine triphosphate (ATP) metabolism are higher in cerebral gray matter than in white matter. Like other excitable tissues, brain contains a phosphocreatine (PCr)/creatine kinase (CK)/ATP system including cytosolic (B-CK) and mitochondrial (Mi-CK) isozymes. High B-CK activity is present in white and gray matter while Mi-CK is mostly in gray matter. An in situ localizing 31P-NMR technique, one-dimensional chemical shift imaging (1D-CSI), has been used to study the PCr/CK/ATP system in these regions. In the metabolically mature 4-week-old piglet, the PCr/nucleoside triphosphate (NTP) ratio measured by the 1D-CSI technique is at least 50% higher in white than gray matter. Total creatine (Cr), ATP, and total NTP concentrations are the same in rapidly frozen rat white and gray matter, suggesting that PCr/Cr ratio is much higher in white matter. The PCr increases more in gray than white matter between 4 days and 4 weeks of age in piglet brain. The CK catalyzed reaction rate constant, measured by combining the saturation transfer experiment with the 1D-CSI, is also much higher in white than gray matter at both ages. The postnatal maturational increase in the CK rate constant is greater in gray matter. In summary, these differences in PCr concentration and CK reaction rates and isozymes characterize two physiologically different PCr/CK/ATP systems in gray and white matter.

Animals↗
PubMed1996

Cerebral oxygenation measured by near infrared spectroscopy during cardiopulmonary bypass and deep hypothermic circulatory arrest in piglets.

Near infrared spectroscopy (NIRS) shows large changes in cerebral oxyhemoglobin (Hbo2), deoxyhemoglobin (Hb), and oxidation state of cytochrome aa3 (Cyto2) in infants undergoing cardiopulmonary bypass and deep hypothermic circulatory arrest (CPB-DHCA). To evaluate the physiologic significance of these clinical NIRS measurements, we applied the technique in a piglet model of CPB-DHCA. After an initial stabilization period on CPB, animals (n = 8) were cooled to 15 degrees C, subjected to DHCA for 1 h, then reperfused with rewarming and monitored for 180 min. NIRS measurements were compared with determinations of cerebral blood flow (CBF). During cooling, Cyto2 decreased markedly, whereas Hbo2 increased. DHCA was associated with a sharp decrease in Hbo2, a corresponding increase in Hb, and a smaller, less consistent further decrease in Cyto2. NIRS measurements recovered toward baseline with reperfusion. CBF decreased during cooling and recovered to baseline levels with reperfusion. These findings are consistent with existing human data and show that 1) cooling is associated with increased oxygenation of cerebral hemoglobin despite a reduction in CBF; 2) Cyto2 becomes more reduced during cooling, consistent with a net cellular oxygen deficit; and 3) DHCA is associated with rapid cerebral hemoglobin deoxygenation and a small further reduction of Cyto2.

Animals↗
PubMed1996

Roles of the suprachiasmatic nucleus and vasoactive intestinal peptide in the response of plasma arginine vasopressin to osmotic challenge.

To clarify the role of neurons containing a vasoactive intestinal peptide (VIP)-like substance (VIP neurons) in the hypothalamic suprachiasmatic nucleus (SCN) in regulation of the plasma arginine vasopressin (AVP) concentration, we examined the effects of bilateral lesions of the SCN and intracranial injection of VIP on the increase in the plasma AVP concentration caused by ip injection of hypertonic (3.6%) saline in rats. The increase in the plasma AVP concentration after ip injection of hypertonic saline was significantly suppressed in rats with bilateral lesions of the SCN. Furthermore, the increase in the plasma AVP concentration elicited by ip injection of hypertonic saline was enhanced by intracerebro-ventricular injection of VIP and suppressed by a VIP antagonist, [Lys1,Pro2,5,Arg3.4,Tyr6]VIP. However, the same dose of VIP injected into the heart had no effect on the increase in the plasma AVP concentration caused by ip injection of hypertonic saline. These results suggest that the SCN and intracranial VIP play important roles in the regulation of the plasma AVP concentration and support the possibility that VIP neurons in the SCN enhance the response of plasma AVP to osmotic challenge.

Animals↗
PubMed1996

Antimicrobial benzopyrans from the receptacle of sunflower.

The antimicrobial substances in sunflower (Helianthus annuus) were investigated. Two antifungal benzopyran derivatives, 6-acetyl-2,2-dimethyl-1,2-benzopyran (1) and 6-acetyl-7-hydroxy-2,2-dimethyl-1,2-benzopyran (2), were isolated from the ethanol extract of sunflower receptacles. The antimicrobial activities of isolated compounds 1 and 2 and their related compounds (precocenes) were evaluated by the paper disk method, using Pyricularia oryzae as the test fungus.

Anti-Infective Agents↗
PubMed1996

Experimental transmission of Babesia ovata oshimensis n. var. of cattle in Japan by Haemaphysalis longicornis.

Transovarial transmission of a newly isolated large intraerythrocytic parasite, Babesia sp. 1 by Haemaphysalis longicornis was experimentally demonstrated. Larvae of H. longicornis were transovarially infected with the parasite by feeding as adults on the calf which had been experimentally infected with B. sp. 1. Piroplasms of B. sp. 1 were observed in peripheral blood of the calf which was infested with the parasite-infected larvae. Based on the transmissibility of the parasite with vector ticks, this parasite was suggested to be a variety of B. ovata. Thus, we propose a new variety name for B. sp. 1 as B. ovata oshimensis n. var.

Animals↗
PubMed1996

[Polyorchidism: a case report and review of the literature].

An 11-year-old boy visited our department complaining of left scrotal painless mass from 6 months ago. The small mass was palpable beside the left testis. Ultrasonography shows isoechoic round shaped mass 5 mm in diameter. At surgery, the mass was connected with the left testis and epididymal head and sharply excised from them. Histological examination showed normal testicular architecture, but spermatogenesis was not found. We report the 18th case of polyorchidism in Japan and made some discussion about polyorchidism.

Child↗
PubMed1996

Effect of the highly selective and nonpeptide delta opioid receptor agonist TAN-67 on the morphine-induced place preference in mice.

The effect of 2-methyl-4a alpha-(3-hydroxyphenyl)-1,2,3,4,4a,5,12, 12a alpha-octahydroquinolino [2,3,3,-g]isoquinoline (TAN-67), a selective non-peptide delta opioid receptor agonist, on the morphine-induced place preference was examined in mice. Morphine (1-5 mg/kg, s.c.) produced a dose-related place preference in mice. In contrast, administration of TAN-67 (5-20 mg/kg, s.c.) did not result in a preference for either the drug- or vehicle-associated place. When TAN-67 (5-20 mg/kg, s.c.) was coadministered with morphine (1 mg/kg, s.c.), the morphine-induced place preference was enhanced dose dependently, and this effect of TAN-67 was suppressed by the pretreatment with naltrindole (1 mg/kg, s.c.), a nonselective delta opioid receptor antagonist, 7-benzylidenenaltrexone (0.05 and 0.5 mg/kg, s.c.), a selective delta 1 opioid receptor antagonist, and naltriben (0.05 and 0.5 mg/kg, s.c.), a selective delta 2 opioid receptor antagonist. In biochemical study, morphine (1 mg/kg, s.c.) or TAN-67 (20 mg/kg, s.c.) alone did not modify dopamine turnover in the limbic forebrain. Coadministration of TAN-67 (20 mg/kg, s.c.) with morphine (1 mg/kg, s.c.) increased DA turnover in the limbic forebrain. This increase in DA turnover in the limbic forebrain was suppressed by pretreatment with naltrindole (1 mg/kg, s.c.) or 7-benzylidenenaltrexone (0.5 mg/kg, s.c.), but not by naltriben (0.5 mg/kg, s.c.). Our results demonstrate that coadministration of TAN-67 with morphine enhances the morphine-induced place preference via activation of both delta 1 and delta 2 opioid receptors, suggesting that both delta 1 and delta 2 opioid receptors may modulate the morphine-induced rewarding effect. In addition, we also found that although both delta 1 and delta 2 opioid receptors may be implicated in the modulation of rewarding effect of morphine, the mechanisms involved may be different for each receptor subtypes, i.e., mu-delta 1 interaction may mainly modulate the rewarding effect of morphine by enhancing neurotransmission of mesolimbic dopamine neurons, although modulation by mu-delta 2 opioid receptor interaction may involve some other dopamine-independent mechanisms.

Analgesics↗
PubMed1995

A method for rapid and complete substitution of the circulating erythrocytes in SCID mice with bovine erythrocytes and use of the substituted mice for bovine hemoprotozoa infections.

We have previously developed an in vivo experimental system for a bovine hemoprotozoan parasite, in which SCID mice were periodically transfused with bovine red blood cells (Bo-RBCs), followed by infection with the parasite. The SCID mice prepared by the original method, however, had both mouse and bovine RBCs in the circulation, and their proportion always fluctuated significantly. In the present study, we aimed to deplete the mouse RBCs circulating in SCID mice and, thereby, to create SCID mice having complete Bo-RBC substitution. An anti-erythropoietin rabbit serum, an anti-mouse RBC rabbit serum and 23 monoclonal anti-mouse RBC rat antibodies were prepared for this purpose. They were examined, after administration into SCID mice, for their ability to decrease hematocrit value and also for any other adverse effect. A monoclonal antibody, clone 2E11, was found to have potent ability to induce clearance of the mouse RBCs in SCID mice without causing toxic effects. SCID mice receiving this antibody together with periodic transfusion of Bo-RBCs had their circulating RBCs completely substituted with Bo-RBCs. Infection of Bo-RBC-SCID mice with bovine hemoprotozoan parasites demonstrated that elimination of the mouse RBCs from Bo-RBC-SCID mice resulted in augmentation of parasite growth.

Anemia↗
PubMed1995

Effects of N-3554S, a polyprenyl phosphate, on B16-F10 mouse melanoma cells.

N-3554S, an optically active S-isomer of alpha-dihydrodecaprenyl phosphate, reduced the tumorigenicity of cultured B16-F10 mouse melanoma cells probably by affecting protein N-glycosylation. Accordingly, membrane glycoprotein samples were prepared from the melanoma cells cultured with or without N-3554S, and amounts and structures of N-linked sugar chains were determined. Analyses of the N-linked oligosaccharides released by hydrazinolysis from these samples and reduced with NaB3H4 revealed that the N-3554S-treated cells contain 1.5-1.8 times as much oligosaccharides as the control cells, and the relative amounts of high-mannose-type and bi-, tri- and tetra-antennary complex-type sugar chains are almost the same between two samples. Western blot analysis, however, showed that binding of L-PHA, which binds to oligosaccharides with the GlcNAc beta 1-->6(GlcNAc beta 1-->2)Man structure, is significantly reduced in 90 K, 96 K, 140 K, 155 K and 180 K glycoproteins in N-3554S-treated cells. Immunoblot analysis showed that the 140 K glycoprotein could be a fibronectin receptor. It was also shown that N-3554S treatment enhances the adhesiveness of the cells to fibronectin. These results indicate that N-3554S affects N-glycosylation of membrane glycoproteins and alters the cell surface properties of B16-F10 cells.

Animals↗
PubMed1995

Discriminative stimulus properties of morphine mediated by mu 1-opioid receptors.

The mu-opioid receptor subtypes involved in the discriminative stimulus properties of morphine were investigated in rats that had been trained to discriminate between 3.0 mg/kg morphine and saline. The discriminative stimulus properties of morphine were significantly attenuated by beta-funaltrexamine (an irreversible mu-opioid receptor antagonist: 10 and 20 mg/kg) and naloxonazine (an irreversible mu 1-opioid receptor antagonist: 20 mg/kg). These results suggest that the discriminative stimulus properties of morphine may be mediated by mu 1-opioid receptors.

Analgesics, Opioid↗
PubMed1995

Development of antimalaria immunity in mice lacking IFN-gamma receptor.

IFN-gamma receptor deficient (IFN-gamma R-/-) mice, immunized with different developmental stages of malaria parasites, were used to define the mechanisms of protection against the various stages of this infection. IFN-gamma R-/- mice failed to develop protective immunity against Plasmodium yoelii sporozoites or liver stages, upon immunization with a single dose of irradiated sporozoites, whereas in immunized wild-type mice, parasite development was strongly inhibited. Immunized wild-type mice expressed high levels of inducible nitric oxide synthase (iNOS) mRNA in their liver, upon challenge with viable sporozoites, whereas only background levels of iNOS were detected in immunized IFN-gamma R-/- mice. In contrast, after immunization with multiple doses of irradiated sporozoites, both IFN-gamma R-/- and wild-type mice mounted an immune response, which strongly inhibited the development of liver stage parasites. In both types of mice, protection occurred in the absence of appreciable expression of liver iNOS mRNA. As for the course of the erythrocytic phase of infection by nonlethal malaria species, P. yoelii yoelii and P. chabaudi adami, we observed only a moderately prolonged parasitemia in IFN-gamma R-/- mice compared with wild-type mice, indicating that IFN-gamma may only play a modest role in immunity against erythrocytic stages. These results indicate that IFN-gamma is the main mediator of the protective mechanism that develops first upon immunization with sporozoites. However, the nature of the anti-parasite mechanism(s) changes in the course of immunization, so that multiple immunizing doses elicit additional protective mechanisms, which are independent of IFN-gamma and its receptor.

Amino Acid Oxidoreductases↗
PubMed1995

Phosphocreatine and ATP regulation in the hypoxic developing rat brain.

Decreased brain ATP and phosphocreatine (PCr) concentrations and intracellular pH were compared in hypoxic 4-, 10-11, and 24-25-day-old rats. Surface coil 31P-nuclear magnetic resonance (NMR) spectra were acquired in vivo every minute before, during, and after 7 min of breathing 4% O2. At all ages PCr decreased rapidly. At the two younger ages, the nucleoside triphosphate signal was still 80-85% of pre-hypoxic values, indicating 20-30% decrease in ATP, when PCr was almost fully depleted. At 24-25 days, PCr initially decreased 40-50% with an ATP loss of about 30%. Then, PCr and ATP decreased simultaneously. The decrease in brain pH was greatest at 24-25 days. More electrocortical seizure activity during hypoxia was seen at 10-11 days than at other ages. Seizure activity was seen only when ATP was less than 20% depleted and was not associated with more rapid decreases in ATP or PCr. At all ages, loss of electrocortical activity occurred when ATP was about 30% depleted. Brain creatine kinase catalyzed flux, measured by the NMR saturation transfer experiment before the hypoxic period, was 4-fold higher at 24-25 days than at 4- or 10-11 days. In conclusion, the temporally coupled depletion of PCr and ATP during hypoxia, which is characteristic of the mature brain, is seen only after the maturational increase in brain CK activity.

Adenosine Triphosphate↗
PubMed1995

Cerebral oxygen supply and utilization during infant cardiac surgery.

The survival of infants with congenital heart disease has improved dramatically. However, the incidence of neurological injury in infants surviving cardiac surgery remains considerable. These neurological sequelae are attributable at least in part to hypoxia-ischemia/reperfusion, which inevitably accompanies infant heart surgery with deep hypothermia, cardiopulmonary bypass, and circulatory arrest. To begin to identify mechanisms of brain injury during infant cardiac surgery, we used near-infrared spectroscopy to study the relationship between cerebral intravascular (hemoglobin) and mitochondrial (cytochrome aa3) oxygenation in 63 infants (aged 1 day to 9 months) undergoing deep hypothermic repair of congenital heart defects, throughout the intraoperative period. Moreover, we assessed the effect of postnatal age on these changes. The cerebral concentration of oxidized cytochrome aa3 decreased from the onset of deep hypothermic cardiopulmonary bypass, despite apparent abundant intravascular oxygenation manifested by a simultaneous increase in the cerebral concentration of oxyhemoglobin. During this interval infants older than 2 weeks had a greater decrease in oxidized cytochrome aa3 than did infants 2 weeks old or younger. During deep hypothermic circulatory arrest, cerebral levels of oxidized cytochrome aa3 remained depressed while those of oxyhemoglobin declined. With reperfusion following circulatory arrest, the recovery of oxidized cytochrome aa3 was delayed, despite a rapid recovery of intravascular oxygenation (HbO2). After rewarming and 60 minutes of reperfusion, only 46% of infants recovered to the baseline level of cerebral oxidized cytochrome aa3. These findings demonstrate a paradoxical dissociation of changes in intravascular and mitochondrial oxygenation during hypothermic cardiopulmonary bypass; a pronounced decrease of mitochondrial oxygenation is established during induction of hypothermia and a delay in recovery of mitochondrial oxygenation occurs following circulatory arrest. These effects were more pronounced in infants older than 2 weeks than in younger infants. The data suggest potentially deleterious impairments of intrinsic mitochondrial function or of delivery of intravascular oxygen to the mitochondrion or both, effects previously undetected and apparently influenced by cerebral maturation.

Brain↗
PubMed1995

Immunohistochemically demonstrated expression of HLA-DR antigen in colorectal adenocarcinomas and its relation to clinicopathological features.

We studied 148 colorectal adenocarcinomas to clarify any correlation between HLA-DR antigen expression on tumor cells and histopathological features. Paraffin sections of formalin-fixed tissues were stained with HLA-DR antigen using the indirect immunoperoxidase technique. All the tumor tissues were divided into two groups, depending on the incidence of HLA-DR-positive cells (greater and lesser than 50%). Carcinoma tissues with a higher incidence showed less mural invasion, lymphoductal invasion, venous invasion, lymphonodular metastasis, and peritoneal metastasis. Tissues with a high HLA-DR reactivity were more often observed for Dukes' A and B stages, whereas those with a low HLA-DR positivity were frequently Dukes' C and D stages. As for the cumulative survival rate, the group with high HLA-DR expression demonstrated significantly better survival. We speculate that HLA-DR expression by colorectal cancer cells exerts a favorable influence on clinical course.

Adenocarcinoma↗
PubMed1995

Use of the Bo-RBC-SCID mouse model for isolation of a Babesia parasite from grazing calves in Japan.

SCID mice with circulating bovine red blood cells (Bo-RBC-SCID mice) were used to isolate Babesia parasites from grazing calves in Japan. Although the initial blood samples obtained from the calves contained both Babesia and Theileria parasites, we were able to isolate only the Babesia parasites by repeated blood passages in Bo-RBC-SCID mice, taking advantage of the much more rapid growth of Babesia than of Theileria. The parasites isolated had characteristics of large-type Babesia, showing typical paired pyriform morphology. The Bo-RBC-SCID mice infected with the Babesia parasites developed a high level of parasitemia, showing severe clinical symptoms characterized by hemoglobinuria, jaundice, and hemolytic anemia. In addition, some mice exhibited nervous symptoms, particularly paralysis of both posterior limbs. The results demonstrated that the Bo-RBC-SCID mouse model was useful not only for isolating Babesia from cattle but also for studying the disease caused by the Babesia infection.

Agriculture↗