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Biomedical subjects

K Motomura

Publications and source records attributed to K Motomura.

At least 19 recordsLinked to original sources
PubMed2000

Effect of atypical antipsychotics on phencyclidine-induced expression of arc in rat brain.

The effect of atypical antipsychotics on the immediate-early gene, arc (activity-regulated cytoskeleton-associated gene), expression was investigated in phencyclidine (PCP)-treated rats using RT-PCR. Administration of PCP (10 mg/kg) increased arc mRNA levels in the prefrontal cortex, nucleus accumbens and posterior cingulate cortex. Pretreatment with clozapine (20 mg/kg), olanzapine (10 mg/kg) and risperidone (2 mg/kg), but not haloperidol (2 mg/kg), prevented PCP-induced arc expression in the prefrontal cortex and nucleus accumbens. Pretreatment of haloperidol increased the striatal arc mRNA levels. Clozapine, olanzapine and haloperidol inhibited the PCP-induced arc expression in the posterior cingulate cortex. These results suggest that the effects of antipsychotic drugs on PCP-induced arc expression in the prefrontal cortex and nucleus accumbens are useful for distinguishing atypical antipsychotic properties of the drugs.

Animals↗
PubMed2000

RAR and RXR expression by Kupffer cells.

Retinoids are known to modulate macrophage differentiation, proliferation, and function including cytokine gene expression. However, signaling of retinoic acid (RA), a biologically active metabolite of vitamin A, in Kupffer cells has not been characterized. This study reports mRNA expression by rat Kupffer cells of RA receptor (RAR) and retinoid X receptor (RXR) subtypes and their binding activities to the RA responsive element (RARE) or retinoid X responsive element (RXRE). Total RNA and nuclear proteins were extracted from Kupffer cells immediately following isolation from livers of normal male Wistar rats. Competitive PCR demonstrated relative mRNA expression of RAR and RXR subtypes in the order of beta>alpha>gamma for and alpha>beta>gamma, respectively. It also demonstrated that the RXR alpha and beta mRNA levels were 5- to 10-fold higher in Kupffer cells than in hepatic stellate cells while RAR mRNA expression was shown to be similar for all the subtypes in both cell types. Gel mobility shift assays of nuclear extracts with labeled RARE and RXRE probes showed distinct binding activities for both responsive elements, which were effectively displaced with cold probes in excess but not with an unrelated oligonucleotide. A supershift assay with an antibody against RARalpha or RXRalpha has confirmed the contribution of both receptors to RARE binding and that of the RXRalpha to RXRE binding activity. These results represent the first demonstration of RA signaling at the nuclear level in Kupffer cells.

Animals↗
PubMed1999

Adsorption of 1-Monoglycerides at the Hexane/Water Interface.

The interfacial tension of a hexane solution of 1-monolaurin against water was measured as a function of temperature and concentration under atmospheric pressure. The thermodynamic quantity changes associated with the adsorption of 1-monolaurin were evaluated and compared with those of the previously reported 1-monomyristin. The decrease of two carbon atoms in the hydrocarbon chain results in a slight expansion of the 1-monolaurin adsorbed film and in a slight decrease in entropy and energy changes compared with those of the 1-monomyristin system. The large negative value of the entropy change at a high concentration is related to the restricted orientation of the polar head group of 1-monolaurin at the hexane/water interface due to the strong interaction between the large hydrophilic group of 1-monolaurin and the water molecules, as in the 1-monomyristin system. The origin of the distinction in the entropy change behavior between the adsorption from the hexane phase and water phase was discussed. The usefulness of an easier calculation process for the partial molar entropy change is verified by comparison with the usual reliable value and with the entropy of adsorption. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Structure Effect on Nonideal Mixing of Alkyl Methyl Sulfoxide and Alkyldimethylphosphine Oxide in Adsorbed Film and Micelle.

The surface tension of aqueous solutions of the octylmethylsulfoxide (OMS)-decyldimethylphosphine oxide (DePO) and decylmethylsulfoxide (DeMS)-octyldimethylphosphine oxide (OPO) mixtures was measured as a function of the total molality of the surfactants and the composition in the surfactants. Compositions in the adsorbed film and micelle were thermodynamically evaluated from the total molality vs composition and the critical micelle concentration (CMC) vs compositon curves, respectively. The phase diagrams of adsorption and micelle formation were drawn and compared with those of the DeMS-DePO mixture previously studied. A large gap in composition was observed between the adsorbed film and the micelle coexisting at the CMC and ascribed to the differences in geometric structure between them and the constituent molecules. Negative deviation from ideal mixings in adsorbed film and micelle was observed for the OMS-DePO mixture, whereas a positive one was observed for the DeMS-OPO. The structure effect on the nonideal mixings was clarified by using the excess thermodynamic functions of adsorption and micelle formation calculated from the activity coefficients in the adsorbed film and micelle. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Adsorption of 1-Monoglycerides at the Hexane/Water Interface.

The interfacial tension of a hexane solution of 1-monomyristin against water was measured as a function of temperature and concentration under atmospheric pressure. The interfacial tension decreases after adding an extremely small amount of 1-monomyristin. The thermodynamic quantity changes associated with the adsorption were evaluated by applying the thermodynamic relations. The adsorbed film of 1-monomyristin exhibits the expanded state on its interfacial pressure vs area curve under this experimental condition. The large negative value of the entropy change at high concentration is related to the restricted orientation of the polar head group of 1-monomyristin at the hexane/water interface. We conclude that the entropy change for the system of 1-monomyristin is smaller than that of tetradecanol because of a greater interaction between the large hydrophilic group of 1-monomyristin and water molecules. An explanation is also given about the difference in energy change for both the systems: the adsorbed film of 1-monomyristin is more stabilized energetically than that of tetradecanol by the greater interaction with water molecules. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Mediastinal lymph node involvement as the initial manifestation of occult thyroid cancer in the surgical treatment of lung cancer: report of a case.

A 63-year-old man was referred to our institute for the treatment of squamous cell carcinoma of the upper lobe of his right lung. A right upper lobectomy of the lung was performed with a mediastinal lymph node dissection. The postoperative pathological examination of the dissected specimens revealed one of the superior mediastinal lymph nodes to be morbid with micrometastasis of occult thyroid cancer, while no node involvement was seen due to lung cancer. A right lobectomy of the thyroid gland with a modified radical neck dissection was done 4 years later after the confirmation of the absence of any recurrent sign of lung cancer. In the resected specimen, papillary thyroid microcarcinoma was observed with several intraglandular metastases and right regional lymph node involvement. Eight months later, a new primary lung cancer developed in the left lung, and a left upper lobectomy of the lung with a mediastinal lymph node dissection was performed. At that time, the absence of mediastinal lymph node metastasis from lung cancer or thyroid cancer was confirmed. Mediastinal lymph node involvement as the initial manifestation of occult thyroid cancer in surgical treatment for lung cancer is rare, but it is important to be aware of the possibility of incidentally detecting occult thyroid cancer in surgical dissections in this area for lung cancer. The appropriate surgical treatment should be determined while carefully considering the prognosis of the lung cancer as well as that of any coexisting malignancy.

Carcinoma, Papillary↗
PubMed1999

Sentinel node biopsy guided by indocyanine green dye in breast cancer patients.

BACKGROUND: We aimed to evaluate whether dye-guided sentinel node biopsy is a useful indicator of axillary node involvement in breast cancer patients and whether clinicopathological features affect its success in identifying sentinel nodes. METHODS: Sentinel node biopsy was performed in patients with stage I or II breast cancer using an indocyanin green dye-guided method. RESULTS: We could identify sentinel nodes in 127 (73.8%) of 172 patients. The mean number of sentinel nodes per patient was 1.7 (range, 1-8) and the mean node size was 9.3 mm (range, 3.0-28.0 mm). Of the 127 patients, 40 (31.5%) also had axillary node involvement. In 16 (40.0%) of these, the sentinel node was the only node involved. There was concordance between sentinel node and axillary node status in 122 (96.1%) of the 127 patients. Success in identifying sentinel nodes was not affected by tumor size, operative procedure, histological type of tumor or tumor location; however, the success rate was significantly lower in patients with axillary node involvement (65.7 vs 79.0% in axillary node-negative patients, p = 0.039) and the presence or absence of lymphatic or vascular invasion in the tumor (63.8 vs 78.9% in patients without lymphatic or vascular invasion, p = 0.043). Sentinel nodes could also be identified significantly more frequently in patients under 50 years old (83.3%) than in those over 50 years old (64.8%, p = 0.009). CONCLUSIONS: Sentinel node biopsy guided by indocyanin green dye is an easy technique with an acceptable success rate in detecting sentinel nodes and predicting axillary nodal status. Axillary node status, the presence or absence of lymphatic or vascular invasion in the tumor and patient age affect its success in identifying sentinel nodes.

Adult↗
PubMed1999

Malignant seeding of the lumpectomy cavity upon breast-conserving surgery.

One of the etiologic factors involved in local recurrence after breast-conserving surgery may be malignant seeding of the wound during the lumpectomy procedure. A total of 340 patients with stage I and II breast cancer were entered into the study. Of these, 270 patients received breast-conserving surgery (BCS group), and the other 70 patients underwent mastectomy (control group). After resection, lavage cytology was performed at the surgical wound. There were 55 patients (20.4%) who showed positive lavage cytology in the BCS group. In the control group, there were only 3 patients (4.3%) with positive cytology. Positivity was significantly higher in the former group (p = 0.00064). Patients with evidence of cutting across cancer lesions showed significantly higher positive rates in lavage cytology (p < 0.00001). Positivity in lavage cytology was significantly higher in patients with positive surgical margins evaluated by frozen sections (p = 0.0017), touch cytology (p < 0.0001) and formalin-fixed, paraffin-embedded sections (lateral or medial margin; p = 0.0036, anterior and posterior margin: p = 0.0210). The positivity was also significantly higher in patients with an extensive intraductal component (p < 0.0001), and less than or equal to 50 (p = 0.0061) years of age. Multivariate analysis revealed that the highest relative risk factor for positive cytology was evidence of cutting across cancer lesions (relative risk = 8. 166; p < 0.00001).

Adult↗
PubMed1998

Miscibility of Butanol and Cationic Surfactant in the Adsorbed Film and Micelle.

Mixed adsorbed films and micelles were investigated by measuring surface tension of the aqueous solutions for the following four mixtures: the n-butanol (NBA)-dodecylammonium chloride (DAC), t-butanol (TBA)-DAC, NBA-dodecyltrimethylammonium chloride (DTAC), and TBA-DTAC. Experimental results were analyzed thermodynamically. Phase diagrams of adsorption and micelle formation and that exhibiting the composition relation of micelle and adsorbed film at CMC were compared among the four systems. Excess Gibbs energy in the adsorbed film gH,E and activity coefficient in the micelle fM2+/- were calculated from the phase diagrams to estimate the miscibility of the butanol and cationic surfactant quantitatively. By comparing the results of the pairs of NBA-DAC and TBA-DAC systems with those of the NBA-DTAC and TBA-DTAC systems, it was shown that the substitution of the polar head group from ammonium to trimethylammonium changes the gH,E value from positive to negative and increases fM2+/-. Furthermore, by comparing the results of the pairs of NBA-DAC and NBA-DTAC systems with those of the TBA-DAC and TBA-DTAC systems, it was shown that the bulky hydrophobic group weakens the molecular interaction between the butanol and the cationic surfactant in the adsorbed film. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Nonideal Mixing of Decyl Methyl Sulfoxide and Decyldimethylphosphine Oxide in Adsorbed Films and Micelles.

The surface tension of aqueous solution of decyl methyl sulfoxide (DeMS) and decyldimethylphosphine oxide (DePO) mixture was measured as a function of the total concentration of the surfactants and the composition in the surfactants. The compositions of the adsobed film and micelle were evaluated by applying thermodynamic equations to the surface tension and the phase diagrams of adsorption and micelle formation were drawn. The DeMS and DePO mixture showed a negative deviation from the ideal mixing in adsorbed film and a positive deviation in micelles. The activity coefficients of surfactant in the adsorbed film and micelle were calculated from the phase diagrams and the nonideality of mixing in the adsorbed film and micelle was clarified in terms of the excess thermodynamic quantities of adsorption and micelle formation. Judging from the negative values of the excess Gibbs free energy and area of adsorption and a positive one of the excess Gibbs free energy of micelle formation, it was concluded that the difference in head group between DeMS and DePO molecules causes a favorable packing in the adsorbed film and an unfavorable one in the micelle. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Effect of chronic haloperidol treatment on synaptic protein mRNAs in the rat brain.

Chronic haloperidol treatment caused significant decreases in the levels of synaptotagmin I and IV, synaptobrevin II, syntaxin 1A and Rab 3A mRNAs in the nucleus accumbens but not in the prefrontal cortex medial field, striatum, substantia nigra and ventral tegmental area. No significant changes in SNAP 25 and synaptophysin mRNA levels were observed in any brain region examined. The reduced expression of synaptic proteins may be related to haloperidol-induced depolarization block of mesolimbic dopamine neurons.

Animals↗
PubMed1998

Structure Effect on Miscibility of Butanol and Dodecyltrimethylammonium Chloride in Adsorbed Film.

Miscibility of components in the adsorbed film for the n-butanol (NBA)-dodecyltrimethylammonium chloride (DTAC) and tert-butyl alcohol (TBA)-DTAC mixtures were investigated by measuring surface tension of the aqueous solutions. The experimental results were analyzed thermodynamically. Diagrams of the excess Gibbs energy in the adsorbed film gH,E vs the composition in the adsorbed film XH 2 were obtained from the phase diagrams of adsorption. The gH,E values of the NBA-DTAC system are more negative than those of the TBA-DTAC system. It is concluded that the molecular interaction between NBA and DTAC is stronger than that between TBA and DTAC. With respect to the mean molar area in the adsorbed film A vs XH 2 curve at a fixed surface tension gamma, the criterion of ideal mixing is demonstrated to be a straight line connecting the pure values. The A vs XH 2 curves are convex downward in both systems and the deviation from the straight line is attributed to the dependence of gH,E on gamma. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Impaired induction of heat shock protein implicated in decreased thermotolerance in a temperature-sensitive multinucleated cell line.

Cells of a temperature-sensitive mutant line (tsFT101) derived from a mouse mammary carcinoma cell line (FM3A) become multinucleated at a non-permissive temperature of 39 degrees C because of disturbed cytokinesis. To explore how this relates to thermotolerance, we examined the proliferative activity of, and heat shock protein (HSP) expression in, FM3A and tsFT101 cells cultured at 37 degrees C and 39 degrees C after heat shock pretreatment (15 min exposure at 45 degrees C). FM3A cells developed thermotolerance when cultured at both 37 degrees C and 39 degrees C, but whereas tsFT101 cells developed thermotolerance at 37 degrees C, this was markedly reduced at 39 degrees C. Western blot analysis showed similar degrees of expression of constitutive HSP70 (HSP73) in FM3A and tsFT101 cells after heat shock pretreatment at both 37 degrees C and 39 degrees C. However, expression of inducible HSP70 (HSP72) was reduced in tsFT101 cells at 39 degrees C compared to 37 degrees C and to FM3A cells at both 37 degrees C and 39 degrees C. Heat shock pretreatment activated DNA binding of heat shock transcription factor (HSF) in FM3A cells at 37 degrees C and 39 degrees C, but only at 37 degrees C in tsFT101 cells. These results indicate that (1) multinucleation caused by disturbed cytokinesis increases temperature sensitivity, (2) HSP70 is critical for the development of thermotolerance in both FM3A and tsFT101 cells, and (3) decreased expression of inducible HSP70 parallels deficient development of thermotolerance in tsFT101 cells cultured at a non-permissive temperature.

Animals↗
PubMed1998

Mechanisms of thyroid hormone action. Implications for the clinical manifestation of thyrotoxicosis.

Serum thyroid hormone concentrations alone do not explain the variability and severity of the range of symptoms observed in thyrotoxic patients. Despite gaps in our understanding of the links between the clinical manifestations of thyrotoxicosis and the underlying mechanisms, much has been learned. A limited number of markers directly reflect T3 action. The future elucidation of T3 targets that mediate these effects should ultimately lead to additional clinical markers of tissue-specific T3 action. The availability of such tests should allow for more specific treatment of individual patients.

Amino Acid Sequence↗
PubMed1998

Increased proliferative activity of osteoblasts in congenital hemifacial hypertrophy.

Congenital hemifacial hypertrophy is expressed in facial asymmetry resulting from unilateral overgrowth. We examined proliferative activity of primary cultured osteoblasts taken from the hemifacial hypertrophic side of an 18-year-old woman compared with the normal side. Both fetal calf serum and basic fibroblast growth factor stimulated osteoblast DNA synthesis, and cultured osteoblast proliferation was markedly increased in the hypertrophic side. Neutralizing antibody against basic fibroblast growth factor was effective to partially block fetal calf serum-induced DNA synthesis. These results suggest that fibroblast growth factor and its receptor signal transduction axis may be selectively involved in affected osteoblasts, leading to progression of congenital hemifacial hypertrophy.

Adolescent↗
PubMed1998

[Mechanical properties of titanium casting obtained using short-time cast procedure].

The purpose of this study was to investigate the mechanical properties of titanium casting obtained using short-time cast procedure. A commercial phosphate-bonded investment for titanium casting were used. And dumbbell-shaped specimens with phi 2 mm x 14 mm parallel portion were cast according to manufacture instruction and by way of three different short-time cast procedures. Then, micro vickers hardness test and tensile test were performed with these specimens. In the hardness test, the micro vickers hardness of 50 approximately 250 microns deep location from specimen surface was ranged from 192.8 to 259.0 Hv; there were significant difference among both the location factor and the casting procedure factor by the two-way ANOVA (p < 0.05). In the tensile test, tensile strength, yield strength, elastic modulus and elongation were obtained: these tensile properties of short-time cast procedures were not significantly different from those of manufacture instruction. These results indicated that the short-time cast procedure for titanium casting was available in the point of mechanical properties. It was, however, not obvious that how the short-time cast procedures effected the dimensional accuracy of titanium casting. Therefore, further investigation was needed for the practical usage of this method.

Dental Casting Technique↗
PubMed1997

Nonideal Mixing in Adsorbed Film and Micelle of Ionic-Nonionic Surfactant Mixtures

The surface tension of aqueous solutions of dodecylammonium chloride-octyl methyl sulfoxide (OMS) and dodecyltrimethylammonium bromide-OMS mixtures was measured as a function of the total molality of surfactants and the composition of OMS. The results were analyzed according to our thermodynamic procedure; the phase diagrams of adsorption and micelle formation and the diagram illustrating the composition relation between the micelle and the adsorbed film at the critical micelle concentration were drawn. The activity coefficient and excess Gibbs energy in the adsorbed film and the micelle were defined and then evaluated from the phase diagrams. They were found to give useful information on the deviation from ideal mixing and intermolecular interaction in the adsorbed film and micelle. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗