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Biomedical subjects

S Yajima

Publications and source records attributed to S Yajima.

At least 19 recordsLinked to original sources
PubMed2001

Synthesis and metal-ion binding properties of monoazathiacrown ethers.

Synthetic procedures for monoazathiacrown ethers were explored, and monoazatrithia-12-crown-4, monoazatetrathia-15-crown-5, and monoazapentathia-18-crown-6 were obtained in moderate yields by the reaction of bis(2-chloroethyl)amine with the appropriate dithiols in the presence of lithium hydroxide in THF. To evaluate metal-ion binding properties of the monoazathiacrown ethers by solvent extraction, lipophilic dodecyl and dodecanoyl groups were incorporated onto the monoazathiacrown ethers. The solvent extraction experiments suggested that monoazathiacrown ethers have Ag(+) and Hg(2+) selectivities and that the relative selectivity between Ag(+) and Hg(2+) depends on their nitrogen atom properties and numbers of sulfur atoms reflecting the respective affinities of nitrogen and sulfur atoms to Hg(2+) and Ag(+). An interesting ability to bind Mg(2+) was observed in the case of N-dodecyl monoazatrithia-12-crown-4.

Journal Article↗
PubMed2001

Dopamine receptor regulating factor, DRRF: a zinc finger transcription factor.

Dopamine receptor genes are under complex transcription control, determining their unique regional distribution in the brain. We describe here a zinc finger type transcription factor, designated dopamine receptor regulating factor (DRRF), which binds to GC and GT boxes in the D1A and D2 dopamine receptor promoters and effectively displaces Sp1 and Sp3 from these sequences. Consequently, DRRF can modulate the activity of these dopamine receptor promoters. Highest DRRF mRNA levels are found in brain with a specific regional distribution including olfactory bulb and tubercle, nucleus accumbens, striatum, hippocampus, amygdala, and frontal cortex. Many of these brain regions also express abundant levels of various dopamine receptors. In vivo, DRRF itself can be regulated by manipulations of dopaminergic transmission. Mice treated with drugs that increase extracellular striatal dopamine levels (cocaine), block dopamine receptors (haloperidol), or destroy dopamine terminals (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) show significant alterations in DRRF mRNA. The latter observations provide a basis for dopamine receptor regulation after these manipulations. We conclude that DRRF is important for modulating dopaminergic transmission in the brain.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2001

The suppression of ornithine decarboxylase expression and cell proliferation at the promotion stage of lung tumorigenesis in mice by alpha-tocopheryloxybutyric acid.

It is known that vitamin E inhibits tumor cell growth in vitro irrespective of its antioxidative effect. However, it is unclear whether the effect in vitro can be applied to the in vivo situation. In order to address this question, we estimated if alpha-tocopheryloxybutyric acid (TSE), a non-antioxidative vitamin E derivative in vivo, could inhibit cell proliferation during the tumorigenic process of lung in mice treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), the most potent carcinogen among tobacco-specific nitrosamines. TSE administration suppressed the labeling index of the proliferating cell nuclear antigen, a marker of cell proliferation at a promotion phase of NNK-induced lung tumorigenesis in mice. Similarly, TSE administration inhibited the elevation of ornithine decarboxylase (ODC) activity and its mRNA at the promotion phase. Of four transcription factors contributing to ODC induction, the change in the level of the c-Myc/Max-consensus oligonucleotide complex was only proportional to the change in ODC mRNA level. These results suggest that vitamin E can inhibit cell proliferation linked with ODC induction at the promotion phase of lung tumorigenesis irrespective of its antioxidative effect and that modulation of the transactivation of the c-Myc/Max complex for the ODC gene by TSE in part contributes to the suppression of ODC induction.

Animals↗
PubMed2001

SoI--gel modification of pH electrode glass membranes for sensing anions and metal ions.

To obtain glass membrane electrodes selective for anions and metal ions, pH electrode glass membranes were modified by a sol-gel method using a quaternary ammonium salt and a bis(crown ether). A chloride ion-sensing glass membrane was designed, in which a pH electrode glass membrane was modified chemically by an alkoxysilyl quaternary ammonium chloride. X-ray photoelectron spectroscopy confirmed the chemical bonding of the quaternary ammonium moiety to the starting glass surface, which afforded the first example of glass-based "anion"-sensing membranes. A neutral carrier-type sodium ion-selective glass membrane was also fabricated which encapsulates a bis(12-crown-4) derivative in its sol-gel-derived surface. Both sol-gel-modified anion and metal ion-selective glass electrodes exhibited high sensitivity to their ion activity changes. The present sol-gel modification paves the way for designing glass-based ion sensors with tailor-made ion selectivities toward anions as well as cations.

Journal Article↗
PubMed2001

Diabetic mastopathy: a case report with reference to the findings of enhanced computed tomography.

We report a case of insulin-dependent diabetic fibrous mastopathy with special reference to the findings of computed tomography (CT). The patient was a 27-year-old woman with a history of insulin-dependent diabetes mellitus from childhood who presented with a right breast tumor. Physical examination showed a stony-hard, ill-defined but freely movable mass under the nipple of the right breast without nipple discharge. Mammography revealed a high-density mass shadow without microcalcifications or spicular formation. Ultrasonographic examination revealed an irregularly-shaped hypoechoic lesion with marked posterior acoustical shadowing. Contrast-enhanced CT revealed poor early phase contrast enhancement and slight delayed phase heterogeneous enhancement. Since core needle biopsy revealed fibrocystic disease, the lesion was suspicious for diabetic mastopathy. Incisional biopsy of the right breast lump was performed. On histopathological examination, the lesion showed fibrosis with dense lymphocytic infiltration around the lobules. Diabetic fibrous mastopathy was diagnosed. Physicians should be aware of the association of long-standing diabetes mellitus with the development of fibrous mastopathy. CT is considered a useful tool to differentiate diabetic mastopathy from breast cancer.

Adult↗
PubMed2001

Clinicopathologic characteristics and survival of patients with clinical Stage I squamous cell carcinomas of the thoracic esophagus treated with three-field lymph node dissection.

OBJECTIVE: Clinicopathologic characteristics and survival rates of patients with clinical Stage I tumors treated with three-field lymph node dissection have not been well investigated. This report documents the results of a series of cases of clinical Stage I squamous cell carcinomas treated with this surgical procedure in our institute. METHODS: From January 1988 to March 1997, 326 patients with carcinomas of the thoracic esophagus underwent transthoracic esophagectomy with three-field lymph node dissection. Two hundred and ninety-seven (91%) of these had squamous cell carcinomas. Fifty-seven (18%) patients with clinical Stage I squamous cell carcinomas of the thoracic esophagus were retrospectively reviewed here. RESULTS: Among 57 clinical Stage I squamous cell carcinomas, ten (18%) were diagnosed as T1-mucosal and 47 (83%) as T1-submucosal. Seventy percent of the patients with clinical T1-mucosal tumors had additional primary esophageal lesions. The operative morbidity and in-hospital mortality rates were 63 and 0%, and the overall 1-, 3-, 5-, and 10-year survival rates were 95, 86, 78, and 70%, respectively. Of the 57 tumors assessed pathologically, 12 (21%) were T1-mucosal, 42 (74%) were T1-submucosal, and three (5%) were T2. Nineteen (33%) exhibited lymph node metastasis. The 1-, 3-, 5-, and 10-year survival rates for patients with lymph node metastasis were 90, 79, 73, and 58%, respectively, as compared with 97, 90, 80, and 76, respectively for patients without lymph node metastasis (P=0.24). The accuracy of preoperative staging, based on both wall penetration and the status regarding lymph node metastasis, was 63%. With reference to the 1997 UICC-TNM staging system, 36 (63%) were pStage I, two (4%) were pStage IIA, 18 (28%) were pStage IIB, and three (6%) were pStage IVB. The 1-, 3-, 5-, and 10-year survival rates for patients with pStage I disease were 97, 92, 85, and 81%, respectively. In those with pStage II or IV disease, the values were 91, 76, 65, and 52%, respectively. CONCLUSIONS: Three-field lymph node dissection may be indicated even for patients with clinical Stage I squamous cell carcinoma requiring surgical intervention because this surgical procedure provides for possible cure by removing unsuspected lymph node metastasis.

Aged↗
PubMed2001

Long-wavelength red light emission from TV and photosensitive siezures.

PURPOSE: We investigated a role of long-wavelength red light emission from TV in the induction of photosensitive seizures by an animated TV program called "Pocket Monsters". METHODS: The luminance energy of recorded color bar was measured by a spectroradiometer in cathode-ray tubes (CRTs) of photosensitive patients with and without seizures on the program (induced patients and photosensitive controls). RESULTS: The mean ratio of long-wavelength red light to total visible range was significantly higher in the CRTs of induced patients than in the CRTs of photosensitive controls. The ratio of luminance energy between at turn-on and at 60 min after turn-on of the CRTs indicated that luminance energy in long-wavelength red range from the CRTs of induced patients increased significantly after turn-on of CRTs. CONCLUSIONS: High amounts of long-wavelength red light emitted from CRTs might play an important role in induction of photosensitive seizures in "Pokemon" incident.

Adolescent↗
PubMed2001

Successful unrelated bone marrow transplantation for a patient with chronic granulomatous disease and associated resistant pneumonitis and Aspergillus osteomyelitis.

We describe the successful treatment of a 20-year-old patient with chronic granulomatous disease (CGD), by unrelated bone marrow transplantation (UBMT). The patient is relatively old compared to other CGD patients treated with BMT. He had had repeated serious infections from early childhood and was diagnosed as CGD, gp91-phox deficiency. Prolonged antibiotic-resistant pneumonitis worsened when the patient was 18 years old. In addition, he suffered Aspergillus osteomyelitis and acute renal failure due to amphotericin B. He received 94 granulocyte transfusions from 94 adult donors and the infections gradually improved. In September 1998, at 20 years of age, he underwent UBMT from an HLA 6 antigen-matched male donor, with CY and TBI conditioning. He received MTX and CsA as prophylaxis against GVHD. No serious complications occurred and rapid engraftment was achieved. Acute GVHD (grade 2, at day 19) and chronic GVHD (limited, at day 192) occurred. However, both were easily controlled. The patient is alive and well with no late rejection 26 months after UBMT.

Adult↗
PubMed2001

Effectiveness of a community leaders' programme to promote healthy lifestyles in Tokyo, Japan.

The aim of this study was to evaluate a community-based health promotion programme in terms of changing: (i) attitudes with respect to a healthy lifestyle; (ii) behaviour with respect to access to health-related information; and (iii) attitudes and health literacy regardless of socio-economic status. In this programme, 20 people are selected every 2 years in each municipality from the lay people of the community, and they are designated as members of a 'community leaders' committee' by the Mayor. They, as a group, have opportunities to gain knowledge about and skills in healthy lifestyles, and undertake voluntary activities to serve the community. A programme intervention sample (INT group) was selected from programme participants from 13 municipalities in the greater Tokyo area. A questionnaire survey was carried out with the INT group and a general population group (REF group). The data obtained for female respondents, aged 30-59 years, in the two sample populations (n = 662 and 1361, respectively) were analysed using the chi(2) test, the Kruskal-Wallis test and multivariate log-linear methods. Another questionnaire was given to female programme participants (n = 200) to identify any changes since the start of their participation. The results showed that the people in the INT group were pursuing healthier lifestyles than those in the REF group; current non-smokers who performed physical exercise and who ate meals regularly paid more attention to a healthy lifestyle and were more interested in the relationship between food and health. From the INT and REF groups, 22 and 4% of people, respectively, frequently obtained information from health professionals, and 29.8 and 10.8%, respectively, were satisfied with their access to health-related information. Results of multivariate log-linear analysis showed that significantly more people in the INT group were doing exercise, eating meals regularly, paying attention to nutritional balance and to food additives, were interested in health, and were satisfied with access to health information, after excluding the effects of age and socio-economic factors (p < 0.05). The results also showed positive changes after the implementation of the programme. These findings indicated that the people in the INT group were significantly more likely to pursue a healthier lifestyle and to have greater health literacy than those in the REF group, regardless of socio-economic status. In conclusion, this community participation approach, employing a committee style, was effective in improving health-related behaviour and in promoting health literacy while overcoming socio-economic variation.

Adult↗
PubMed2000

Silver ion-selective electrodes using pi-coordinate calix

Calix[4]arene derivatives incorporating pi-coordinate substituents such as allyl, benzyl, and propargyl groups were designed as soft neutral carriers for silver ion sensors. Most of all, tert-butylcalix[4]arene tetra(allyl ether) is an excellent neutral carrier for plasticized poly(vinyl chloride)-membrane silver ion-selective electrodes. The ion sensors showed high silver ion selectivity over alkali metal ions and also good selectivity against other soft metal ions such as lead and mercury(II) ions. The electrode potential response was as rapid as that for neutral-carrier-type alkali metal ion electrodes due to the soft interaction between pi-coordinate substituents and silver ion, which was elucidated by 1H NMR spectroscopy.

Journal Article↗
PubMed2000

The effect of 6-methylthiohexyl isothiocyanate isolated from Wasabia japonica (wasabi) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-buatnone-induced lung tumorigenesis in mice.

The present study was undertaken to estimate the effect of 6-methylthiohexyl isothiocyanate (6MHITC) isolated from Wasabia japonica (wasabi) pretreatment on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK)-induced lung tumorigenesis in mice. Pretreatment with 6MHITC for 4 consecutive days at a daily dose of 5 micromol significantly inhibited NNK-induced O(6)-methylguanine formation in lungs at 4 h after the injection. In conjugation with this inhibitory effect, 6MHITC suppressed the increase in proliferating nuclear cell antigen level as well as ornithine decarboxylase activity at a promotion stage of NNK-induced lung tumorigenesis. Finally, this treatment of 6MHITC suppressed the NNK-induced lung tumorigenesis in mice. These results suggest that 6MHITC inhibits the development of lung tumors in mice treated with NNK, due to the suppression of initiation stage.

Animals↗
PubMed2000

Rifampicin-associated pseudomembranous colitis.

We report a case of pseudomembranous colitis that developed in a patient with liver cirrhosis during anti-tuberculosis therapy with rifampicin and isoniazid. The association between rifampicin and pseudomembranous colitis has been controversial; this report, however, supports the association. Colonoscopy performed 3 days after the onset of the pseudomembranous colitis revealed only reddish patches and a few aphthoid lesions, but 4 days later pseudomembranes were apparent. The pseudomembranous colitis was successfully controlled by discontinuation of the anti-tuberculosis agents, along with the administration of lactic acid bacteria, without vancomycin or metronidazole. Possible predisposing factors for the development of pseudomembranous colitis in this patient are also discussed.

Antibiotics, Antitubercular↗
PubMed2000

Vitamin E inhibits cell proliferation and the activation of extracellular signal-regulated kinase during the promotion phase of lung tumorigenesis irrespective of antioxidative effect.

We have already reported that the activation of extracellular signal-regulated kinase (Erk) is critical in the stimulation of cell proliferation during the promotion stage of urethane-induced lung tumorigenesis in mice. Also, we have found that vitamin E suppresses lung tumorigenesis by inhibiting cell proliferation at the promotion stage. However, it is still unclear whether this inhibitory effect at the promotion stage is based on the antioxidative effect of vitamin E or not. In order to address this question, we examined the inhibitory effect of alpha-tocopheryloxybutyric acid (TSE), an ether derivative of vitamin E that cannot act as an antioxidant in vivo, on cell proliferation and the activation of Erk during promotion of lung tumorigenesis. On day 30 after urethane injection (750 mg/kg, i. p.) in A/J mice, TSE or vitamin E at 100 micromol/kg, p.o. was administered. Twenty-four hours after the final administration, the mice were killed to analyze cell proliferation and related parameters. The labeling index of proliferating cell nuclear antigen (a marker of cell proliferation) and ornithine decarboxylase activity (a marker of the promotion stage in lungs) were attenuated by treatment with TSE or vitamin E. TSE or vitamin E treatment also inhibited urethane-induced activation of Erk and suppressed the activation of other essential members of the Erk cascade (Ras, Raf and Mek). These results suggest that vitamin E inhibits cell proliferation and activation of the Erk cascade during promotion of urethane-induced lung tumorigenesis in mice, independent of its antioxidative effect.

Animals↗
PubMed1999

Regulation of striatal dopamine receptors by corticosterone: an in vivo and in vitro study.

The effects of chronic corticosterone administration and adrenalectomy on the expression of brain dopamine receptors were studied in rats. In situ hybridization and receptor binding autoradiography were carried out to determine D1, D2 and D3 receptor expression in dorsal and ventral striata. Except for down-regulation of D2 mRNA in dorsal striatum after 2 week corticosterone treatment, no other significant changes were detected. In addition, the transcriptional regulation of D1 and D2 gene promoters by glucocorticoids was studied in neuroblastoma cell lines using transient transfections. While a small segment of the D2-promoter could be activated three-fold by dexamethasone, large fragments of neither D1 or D2 promoters were regulated by this treatment. Glucocorticoids do not appear to have direct overall effects on striatal dopamine receptor expression. The observed down-regulation of D2 receptor mRNA in the dorsal striatum in vivo is likely secondary to increased striatal dopamine release induced by corticosterone.

Adrenal Glands↗
PubMed1999

Regulation of striatal dopamine receptors by estrogen.

The ability of estrogen to modulate the expression of ventral and dorsal striatal dopamine receptors D(1), D(2,) and D(3) was examined in vivo using semi-quantitative in situ hybridization and ligand binding autoradiography. Two-week treatment with subcutaneous pellets of 17beta-estradiol (25 mg) downregulated D(2) dopamine receptor mRNA in both dorsal and ventral striatum (shell and core regions of nucleus accumbens). No significant changes in D(1) or D(3) mRNA expression were detected. Ligand binding autoradiography did not reveal changes in D(1), D(2,) or D(3) receptor protein expression. We also assessed the ability of 17beta-estradiol to regulate D(2) gene promoter activity in NB41A3 neuroblastoma cells that express this gene endogenously using co-transfections with an estrogen receptor expression vector. While a small fragment of the D(2) promoter could be activated 2.5-fold by estrogen, a larger portion of the D(2) gene was not regulated by this treatment. Estrogens do not appear to have a net effect on striatal dopamine receptor expression. The observed downregulation of D(2) receptor mRNA in the dorsal and ventral striatum in vivo could be secondary to the increased striatal dopamine release induced by estrogen. Synapse 34:222-227, 1999. Published 1999 Wiley-Liss, Inc.

Animals↗
PubMed1999

Activation of extracellular signal-regulated kinase in lung tissues of mice treated with carcinogen.

The activation of extracellular signal-regulated kinase (ERK) in lung tissues of mice, as determined by the appearance of phosphorylated form, was observed on day 30 after urethane injection, and the activation also occurred in urethane-induced lung tumors. Immunohistochemical analysis using anti-phosphorylated ERK antibody indicated that the active form of ERK localized in alveolar epithelial cells. Furthermore, we confirmed by immunoprecipitation and immunoblot analysis that other essential components of the ERK cascade, that is, Ras, Raf and MEK (known as ERK kinase) were activated. These results indicate that the activation of the ERK signal in alveolar epithelial cells at the early stage of urethane-induced lung carcinogenesis is an important factor to develop lung tumors.

Animals↗
PubMed1999

Neural cell line-specific regulatory DNA cassettes harboring the murine D1A dopamine receptor promoter.

Transcription in the human and rat D1A dopamine receptor genes proceeds from two distinct promoters in neuronal cells while only the downstream intronic promoter is active in renal cells. To investigate the utility of these promoters in the brain cell-specific expression of transgenes, we now studied the 5' flanking region of the murine D1A gene. We confirmed the presence of two functional promoters utilized for the tissue-specific regulation of this gene similar to its human and rat homologues. The cloned 1.4-kb genomic fragment spans nucleotides - 967 to + 384 relative to the first ATG codon and includes intron 1 between bases -534 to -420. Transient expression analyses using various chloramphenicol acetyltransferase constructs revealed that the murine D1A upstream promoter fused with the human D1A gene activator sequence ActAR1 has potent transcriptional activity in a D1A-expressing neuronal cell line but not in other cell lines tested including renal (OK cells), glial (C6) and hepatic (HepG2), suggesting that this hybrid construct harbors neural cell-specific elements. The availability of potent regulatory DNA cassettes harboring the murine D1A gene promoter could aid testing the neuronal-specific expression of transgenes in vivo.

Amino Acid Sequence↗