Search PubMed⌕ Search

Biomedical subjects

T Komatsu

Publications and source records attributed to T Komatsu.

At least 73 records · Page 4Linked to original sources
PubMed2000

Ultrasonography of Zenker's diverticulum: special reference to differential diagnosis from thyroid nodules.

There have been only two case reports so far in literature on ultrasonographic features of Zenker's diverticulum. We report a case of Zenker's diverticulum and discuss the ultrasonographic images in comparison with those of thyroid nodules. Awareness of changeable internal echoes and not mistaking strong echogenic foci caused by air for calcification were most important for making the differential diagnosis of Zenker's diverticulum from thyroid nodules.

Diagnosis, Differential↗
PubMed2000

A nucleoside-nucleotide mixture may reduce memory deterioration in old senescence-accelerated mice.

We investigated the effects of a mixture of dietary nucleosides and nucleotides (NS + NT) on memory in 1- and 7-mo-old senescence-accelerated mice (SAM). Memory retention was studied with passive avoidance (step-through) and active avoidance (shuttle) tests. For 14 wk, mice in the control groups were fed a 20 g of casein/100 g diet, whereas the NS + NT groups were fed this diet supplemented with a 0.5 g of NS + NT mixture/100 g. All mice were killed at wk 14, and we studied the brain histopathology. Lipofuscin, monovacuoles and multiple vacuoles of various brain regions were measured. Body weight, food intake and ambulatory activity did not differ between the control and NS + NT groups. In old mice, the time of passive avoidance was significantly higher in the NS + NT group than in the control group at d 1 and 7 (P: < 0.05). However, such an effect of NS + NT was not observed in young mice. In the active avoidance test, the incidence of successful avoidance in old mice was higher in the NS + NT group than in the control group at d 1 and 2 (P: < 0.05). The percentages of specific brain cells containing lipofuscin were lower in NS + NT groups than in the control groups in both young and old mice (P: < 0.05). The number of monovacuoles and multiple vacuoles in specific brain regions tended to be lower (P: = 0.1-0.25) in NS + NT than in control groups, with significant differences in the microvacuoles of the middle cortex of young mice and in the multiple vacuoles in the hind cortex of old mice (P: < 0. 05). These results suggest that increased dietary NS + NT may be associated with decreases in the age-induced deterioration of brain morphology and certain memory tasks.

Age Factors↗
PubMed2000

Sendai virus blocks alpha interferon signaling to signal transducers and activators of transcription.

We demonstrate here that Sendai virus (SeV) blocks alpha interferon (IFN-alpha) signaling to signal transducers and activators of transcription (STATs) in HeLa cells. IFN-alpha-stimulated tyrosine phosphorylation of STATs and subsequent formation of the IFN-stimulated gene factor 3 transcription complex were inhibited in SeV-infected cells, resulting in inefficient induction of IFN-stimulated gene products. None of the components of the signaling pathway-type I IFN receptor subunits Jak1, Tyk2, Stat1, Stat2, and p48-was degraded. Moreover, tyrosine phosphorylation of Jak1 in response to IFN-alpha was unaffected at the early phase of infection, suggesting that oligomerization of the receptor subunits proceeded normally. In contrast to Jak1, IFN-alpha-stimulated tyrosine phosphorylation of Tyk2 was partially inhibited. Therefore, this partial inhibition of activation of Tyk2 probably contributes to the subsequent failure in the activation of STATs.

Cytokines↗
PubMed2000

Serum progesterone and estradiol-17beta concentrations in captive and free-ranging adult female japanese black bears (Ursus thibetanus japonicus).

Progesterone (P4) and estradiol-17beta (E2) concentrations were measured in serum samples obtained from 23 captive and 23 free-ranging adult female Japanese black bears. We then determined the relationship between changes in these sex steroid hormones and pregnancy. In all captive bears, which included animals of both known and unknown reproductive status, serum P4 concentrations were low from April to July, then tended to become higher after August. The levels then became much higher still in November and December, but returned to low levels in March. Serum P4 concentrations in eight captive pregnant bears, which had parturitions the following spring, increased gradually from August (0.5-2.4 ng/ml) to October (0.9-3.6 ng/ml), and achieved significantly higher maximum levels in December (7.2-18.0 ng/ml). Thereafter, serum P4 concentrations tended to decrease (3.5-6.4 ng/ml in January and 0.3-0.7 ng/ml in March). In all captive bears, serum E2 concentrations varied from April to October but showed low levels in November and December, and became high in January. Serum E2 concentrations in the eight pregnant bears were high in May (95.6-191.4 pg/ml) and varied from August to October (35.6-143.3 pg/ml). Subsequently, serum E2 concentrations in December dropped to significantly lower minimum levels (5.3-11.9 pg/ml) and increased again in January (67.6-153.1 pg/ml). Among the free-ranging bears, the data on serum P4 concentrations in eight bears led to expectations of pregnancy, whereas serum E2 concentrations showed no distinct evidence related to pregnancy. These results, particularly in captive pregnant bears, indicate that a marked increase of P4 in December might be accompanied by reactivation of the corpus luteum preceding implantation. Furthermore, changes in E2 concentrations suggested the possibility that a decline in December and an increase in January are associated with implantation and parturition, respectively.

Animals↗
PubMed2000

Hemodynamics of small hepatic focal nodular hyperplasia: evaluation with single-level dynamic CT during hepatic arteriography.

OBJECTIVE: We examined the usefulness of single-level dynamic CT during hepatic arteriography to observe the hemodynamics of small hepatic focal nodular hyperplasia. CONCLUSION: Single-level dynamic CT during hepatic arteriography revealed not only centrifugal blood supply through the fibrous stellate scar, but also the drainage to dilated veins in or near the focal nodular hyperplasia nodule and directly to the hepatic sinusoid in the surrounding liver.

Adult↗
PubMed2000

Human herpesviruses in primary ocular lymphoma.

Several human lymphotropic herpesviruses have been found in certain lymphoproliferative disorders and implicated as possible etiologic factors or as modulating elements of the diseases. To assess a possible association of the human herpesviruses with lymphomas arising from mucosa-associated lymphoid tissue (MALT), we evaluated the presence of four human herpesviruses, Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), HHV-7, and HHV-8, in the biopsied specimens from 14 patients with primary ocular MALT lymphomas. EBV DNA sequences were detected in four specimens by polymerase chain reaction (PCR), and four cases were positive for HHV-6 DNA. In situ hybridization showed that three and two of 14 cases were positive for EBV mRNA and HHV-6 DNA, respectively. Neither HHV-7 nor HHV-8 sequences could be detected by PCR. These findings would stimulate further investigation as to the involvement of these lymphotropic viruses in the pathogenesis of a subset of low-grade primary ocular lymphomas.

Adult↗
PubMed2000

[Ability to avoid falls among aged residents in a barrier-free welfare institution].

This study was carried out to investigate the physical functions of the elderly, living in a barrier-free home for the aged and to obtain basic data for giving appropriate guidance on exercise and daily life. A total of 38 women were tested. These included 18 persons (aged 72-87: mean: 80.7) who were living in the home for the aged, and 20 (aged 75-86: mean: 78.3) who voluntarily participated in the "fall prevention school", established in Tokyo Kosei-Nenkin Hospital. The following examinations were done: 1) BMI, Waist/Hip ratio; 2) good walker's index consisting of 10 m walking times, maximum length of steps, and 40 cm-staircase climbing; and 3) equilibrium examination done by gravinography. Statistical analysis was carried out using a paired t-test (p < 0.01). Values for the "good-walker's index" were significantly lower in, the "home" group than in the "school" group (p < 0.01). This was especially obvious with 40 cm-staircase climbing. Many of the subjects from the institution group required assistance and there was a significant difference in the chi-squire square distribution between the two groups. Furthermore, on gravinography, the "home" group had significantly inferior values in total length (cm) and Romberg's ratio (p < 0.01). It was clear that residents in the barrier-free home had a significant reduction in good-walker's index, indicating an apparent weakening of physical function.

Accidental Falls↗
PubMed2000

[A questionnaire survey of the panel discussion at the annual meeting of the Japan Society of Anesthesiologists].

Two hundred questionnaire sheets were distributed to the audience of the panel discussion session titled "Progresses of balanced anesthesia" at the annual meeting of the Japan Society of Anesthesiologists. The audience was requested to rate their interest to the program and also rate the usefulness of the presentations by each panel. One hundred and seventeen questionnaire sheets (58%) were returned. Eighty five % of the returned survey expressed interests in the program. Forty three % expressed their interests in altering their anesthesia techniques along the line of the recommendation by the panels. These data suggest that the program met the educational need of the audience. Questionnaire survey may be useful in identifying the need of the members, and thus helpful in planning future meetings of the society.

Anesthesiology↗
PubMed2000

Effect of amino acid mixtures on nasal allergic responses induced by toluene diisocyanate in mice.

We studied the effect of various amino acid mixtures on nasal allergy induced by the intranasal application of toluene diisocyanate (TDI) in mice. In Experiment 1 (Exp. 1), mice were fed a 25% casein, soy protein isolate (SPI), egg white protein (EW) or gluten diet. In Experiment 2 (Exp. 2), mice were fed a 25% amino acid mixture diets patterned after casein (AA-casein), SPI (AA-SPI), EW protein (AA-EW) or gluten (AA-gluten). In Experiment 3 3 (Exp. 3) we modified the glutamine/glutamic acid (Gln/Glu) concentrations in the amino acid mixtures. Mice were fed a 25% AA-SPI, low Gln/Glu AA-SPI (LG-AA-SPI), AA-EW or high Gln/Glu AA-EW (HG-AA-EW) diet. At the 5th week, mice were divided into sensitized (sen-) and non-sensitized (ns-) groups. The mice in sensitized groups were treated with two courses of intranasal application of toluene diisocyanate (TDI) in ethyl acetate for 5 consecutive days, separated by 9 days rest. The non-sensitized groups of mice were treated with a vehicle. Nine days after the second sensitization, all mice were provoked by TDI. Nasal responses and serum IgE concentration were studied. The findings of Exp. 1 showed that the sen-EW group exhibited a lower body weight gain, higher nasal symptom score and higher IgE concentration than the other sensitized groups. The findings dings of Exp. 2 showed that the sen-EW group had a lower body weight gain, higher nasal symptom score and higher IgE concentration than the other sensitized groups. In Exp. 3, the AA-EW group showed a higher total nasal score and IgE concentration than the HG-AA-EW group, however, the findings of LG-AA-SPI and AA-SPI were similar. These findings demonstrated that amino acid mixtures affect nasal allergy induced by the intranasal application of TDI in mice.

Administration, Intranasal↗
PubMed2000

Formation of a dihydroxy metabolite of phenytoin in human liver microsomes/cytosol: roles of cytochromes P450 2C9, 2C19, and 3A4.

Formation of four oxidative metabolites from the anticonvulsant drug phenytoin (DPH) catalyzed by human liver microsomal cytochrome P450 (P450) enzymes was determined simultaneously. Under the conditions in which linearity for formation of 4'-hydroxylated DPH (4'-HPPH; main metabolite) was observed, human liver cytosol increased microsome-mediated DPH oxidation. 3',4'-Dihydroxylated product (3', 4'-diHPPH) formation was 10 to 40% of total DPH oxidation in the presence of liver cytosol. 3'-Hydroxy DPH formation was catalyzed by only one of the human liver microsomal samples examined and 3', 4'-dihydrodiol formation could not be detected in all samples. In the presence of liver cytosol, 3',4'-diHPPH formation activity from 100 microM 4'-HPPH was correlated with testosterone 6beta-hydroxylation activity and CYP3A4 content. However, 3', 4'-diHPPH formation using 1 or 10 microM 4'-HPPH as a substrate was not correlated with contents of any P450s or marker activities. Of 10 cDNA-expressed human P450 enzymes examined, CYP2C19, CYP2C9, and CYP3A4 catalyzed 3',4'-diHPPH formation from the primary hydroxylated metabolites (3'-hydroxy-DPH and 4'-HPPH). Fluvoxamine and anti-CYP2C antibody inhibited 3',4'-diHPPH formation from 10 microM 4'-HPPH in a human liver sample that contained relatively high levels of CYP2C, whereas ketoconazole and anti-CYP3A antibody showed inhibitory effects on the activities in liver microsomal samples in which CYP3A4 levels were relatively high. These results suggest that CYP2C9, CYP2C19, and CYP3A4 all have catalytic activities in 3',4'-diHPPH formation from primary hydroxylated metabolites in human liver and that the hepatic contents of these three P450 forms determine which P450 enzymes play major roles of DPH oxidation in individual humans.

Catalysis↗
PubMed2000

Roles of cytochromes P450 1A2, 2A6, and 2C8 in 5-fluorouracil formation from tegafur, an anticancer prodrug, in human liver microsomes.

Tegafur, an anticancer prodrug, is bioactivated to 5-fluorouracil (5-FU) mainly by cytochrome P450 (P450) enzymes. The conversion from tegafur into 5-FU catalyzed by human liver microsomal P450 enzymes was investigated. In fourteen cDNA-expressed human P450 enzymes having measurable activities, CYP1A2, CYP2A6, CYP2E1, and CYP3A5 were highly active in catalyzing 5-FU formation at a tegafur concentration of 100 microM. Kinetic analysis revealed that CYP1A2 had the highest V(max)/K(m) value and that the V(max) value of CYP2A6 was high in 5-FU formation. In human liver microsomes, the activities of 5-FU formation from 10 microM, 100 microM, and 1 mM tegafur were significantly correlated with both coumarin 7-hydroxylation (r = 0.83, 0.86, and 0.74) and paclitaxel 6 alpha-hydroxylation (r = 0.77, 0.62, and 0.85) activities, respectively. Coumarin efficiently inhibited the 5-FU formation activities from 100 microM and 1 mM tegafur catalyzed by human liver microsomes that had high coumarin 7-hydroxylation activity. On the other hand, furafylline, fluvoxamine, and quercetin, as well as coumarin, showed inhibitory effects in liver microsomes that had high catalytic activities of 5-FU formation. The other P450 inhibitors examined showed weak or no inhibition in human liver microsomes. Polyclonal anti-CYP1A2 antibody, monoclonal anti-CYP2A6, and anti-CYP2C8 antibodies inhibited 5-FU formation activities to different extents in those two microsomal samples. These results suggest that CYP1A2, CYP2A6, and CYP2C8 have important roles in human liver microsomal 5-FU formation and that the involvement of these three P450 forms differs among individual humans.

Antimetabolites, Antineoplastic↗
PubMed2000

Predominant T helper 1 cells in patients with idiopathic portal hypertension.

BACKGROUND: The pathologic mechanism of idiopathic portal hypertension (IPH) is unknown. Because cytokines and the balance of T helper (h) 1 and Th2 CD4+ T cells have been reported to be important for regulating the immune response, in the present study we investigated the role of cytokines and the distribution of cytokine-producing cells in IPH patients. METHODS: Serum levels of tumor necrosis factor (TNF)-alpha, soluble TNF receptor-I, -II, interferon (IFN)-gamma and interleukin (IL)-4 were measured in IPH patients, fatty liver patients, chronic hepatitis patients and control subjects. The percentages of Th0, Th1 and Th2 CD4+ T cells were examined in peripheral and spleen lymphocytes in IPH patients by intracellular staining. RESULTS: Serum levels of TNF-alpha, soluble TNF receptor-I, interferon-gamma and IL-4 of IPH patients were not increased in comparison with control subjects. Only the mean value of soluble TNF receptor-II was significantly higher than that of control subjects and fatty liver patients. The ratios of Th1 and Th2 in both peripheral and spleen lymphocytes of IPH patients were significantly increased compared with the ratios found in peripheral lymphocytes of control subjects. The increase in the ratios was due to a decrease in the percentage of Th2 CD4+ T cells. CONCLUSIONS: These results suggest that the imbalance of Th1 and Th2 CD4+ T cells and TNF may be associated with the pathogenesis of IPH.

Adult↗
PubMed1999

Chemical characterization of milk oligosaccharides of the Japanese black bear, Ursus thibetanus japonicus.

Two trisaccharides, two tetrasaccharides, one penta-, one hexa-, two hepta-, one deca- and two undeca-saccharides were isolated from several Japanese black bear milk samples by chloroform/methanol extraction, gel filtration and preparative thin-layer chromatography. The oligosaccharides were characterized by 1H-NMR as follows: Gal(alpha 1-3)Gal(beta 1-4)Glc (alpha 3'-galactosyllactose), Fuc(alpha 1-2)Gal(beta 1-4)Glc (2'-fucosyllactose), Gal(alpha 1-3)(Fuc(alpha 1-2))Gal(beta 1-4)Glc (B-tetrasaccharide), Gal(alpha 1-3)Gal(beta 1-4)(Fuc(alpha 1-3))Glc, Gal(alpha 1-3)[Fuc(alpha 1-2)]Gal(beta 1-4)[Fuc(alpha 1-3)]Glc (B-pentasaccharide), Gal(alpha 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)Gal(beta 1-4)Glc (monofucosylhexasaccharide), Gal(alpha 1-3)[Fuc(alpha 1-2)]Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)Gal(beta 1-4)Glc (difucosylheptasaccharide), Gal(alpha 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]Glc (difucosylheptasaccharide), Gal(alpha 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)[Gal(alpha 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-6)]Gal(beta 1-4)Glc (difucosyldecasaccharide), Gal(alpha 1-3)[Fuc(alpha 1-2)]Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)[Gal(alpha 1-3) Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-6)]Gal(beta 1-4)Glc (trifucosylundecasaccharide), Gal(alpha 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)[Gal(alpha 1-3)[Fuc(alpha 1-2)]Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-6)]Gal(beta 1-4)Glc (trifucosylundecasaccharide). Lactose was present only in trace amounts. B-pentasaccharide was a dominant saccharide in early lactation milk, while alpha 3'-galactosyllactose was dominant in milk, later. The milk oligosaccharides of the Japanese black bear were compared with those of the Ezo brown bear.

Animals↗
PubMed1999

Knockout of the Sendai virus C gene eliminates the viral ability to prevent the interferon-alpha/beta-mediated responses.

Sendai virus (SeV) renders cells unresponsive to interferon (IFN)-alpha. To identify viral factors involved in this process, we examined whether recombinant SeVs, which could not express V protein, subsets of C proteins (C, C', Y1 and Y2) or any of four C proteins, retained the capability of impeding IFN-alpha-mediated responses. Among these viruses, only the 4C knockout virus completely lost the ability to suppress the induction of IFN-alpha-stimulated gene products and the subsequent establishment of an anti-viral state. These findings reveal crucial roles of the SeV C proteins in blocking IFN-alpha-mediated responses.

Antiviral Agents↗
PubMed1999

Mechanisms of cytokine-mediated inhibition of viral replication.

In this report, the role of nitric oxide synthase (NOS) and IL-12 administration in inhibition of vesicular stomatitis virus (VSV) from infected neuroblastoma cells was examined. We previously have shown that cytokine treatment of cells results in the induction of NOS-1, and this is associated with a 2 log inhibition of VSV production. We performed these studies to examine the mechanism by which viral replication is suppressed. Neuroblastoma cells (NB41A3) were treated with either IL-12 or medium and subsequently infected with VSV. Viral protein and mRNA were isolated from these cells, and their levels were measured by Western or Northern blots, respectively. mRNA levels were decreased modestly, but viral proteins were decreased substantially in cells pretreated with IL-12, suggesting that the inhibitory effect of NO is working at the translational level. Cytokine treatment of cells was not associated with oxidative stress. The viral proteins also were nitrosylated. These data suggest that the mechanism of NO inhibition of viral replication occurs through translational interference and posttranslational modifications of viral components.

Blotting, Northern↗
PubMed1999

Neuronal expression of NOS-1 is required for host recovery from viral encephalitis.

The role of nitric oxide synthase (NOS) in host defense and clearance of vesicular stomatitis virus (VSV) from the central nervous system (CNS) was examined. NOS-1, NOS-2, and NOS-3 knockout mice were infected with VSV and were treated with either IL-12 or medium. IL-12 treatment resulted in substantially decreased VSV titers in wildtype and NOS-3 knockout mice, but had a marginal effect in the NOS-1 and NOS-2 knockout mice. NOS-1 expression in neurons was associated with survival from VSV infection. The data indicate that the enzyme activity is local, since NOS-2 expression in microglia and inflammatory macrophages and NOS-3 expression in astrocytes, endothelial cells, and ependymal cells did not compensate.

Animals↗