Search PubMed⌕ Search

Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 163 records · Page 9Linked to original sources
PubMed2000

Serum levels of ifn-inducible PROTEIN-10 relating to the activity of systemic lupus erythematosus.

IFN-inducible protein-10 (IP-10) is supposed to act as a specific chemoattractant for Th(1)cells. Since Th(1)cells and IFN-gamma are shown to be important for developing systemic lupus erythematosus (SLE), we examined the relationship between serum IP-10 levels and the disease activity. Serum IP-10 levels were markedly increased in the SLE patients depending on the level of disease activity, whereas not in the patients with rheumatoid arthritis (RA). On the other hand, serum MCP-1 levels were increased to a similar extent both in RA and inactive SLE patients, and a little more elevated in active SLE patients. Serum IP-10 levels in SLE patients correlated positively and negatively with levels of anti-DNA antibody and complements, respectively, whereas MCP-1 levels correlated less or not at all. These results suggest that serum IP-10 levels could be a good indicator for the activity of SLE and that IP-10 could play an important immunological role in SLE.

Adolescent↗
PubMed2000

The effects of body positioning on sucking behaviour in sick neonates.

UNLABELLED: Some infants show better oxygenation in the prone position compared to the supine position while they are bottle-fed; however, the reason for this phenomenon is not clear. The purpose of this study was to obtain a better understanding of the effects of body position on the oral feeding performance, i.e. the sucking pressure, frequency, efficiency, and ventilation. A total of 14 infants (12 full-term, 2 preterm), who often showed O2 desaturation (SpO2 < 90) during oral feeding, were enrolled in the study. The infants were fed either in the supine position or in the prone position throughout feeding. Oxygen saturation was recorded with a pulse oxymeter. The sucking pressure was measured with a 1 mm I.D. silicone tube inserted into the artificial nipple. The ventilation volume during bottle feeding was measured with a pneumotachograph. The prone position resulted in better oxygenation (97.2 +/- 0.6% prone, 92.5 +/- 0.9% supine, P < 0.05) and larger tidal volume (6.4 +/- 0.8 ml/kg prone and 4.9 +/- 0.6 ml/kg supine, P < 0.05), although the minute ventilation during bottle-feeding was not different from that in the supine position. In the prone position, the sucking pressure and frequency were higher and the duration of each suck was shorter. CONCLUSION: Sucking in the prone position may to some extent reduce disadvantages of oral feeding on ventilation.

Gestational Age↗
PubMed2000

Effect of cytochalasin D on the growth, encystation, and multinucleation of Entamoeba invadens.

The effect of cytochalasin D, a specific inhibitor of microfilaments, on the growth, encystation, and multinucleation of Entamoeba invadens was examined. Cytochalasin D blocked the growth of axenic E. invadens strain IP-1 in a dose-dependent manner, which suggests that the drug is effective against this species of Entamoeba as well as against E. histolytica strain HM1: IMSS as previously demonstrated. Encystation of E. invadens as induced in vitro was also inhibited by cytochalasin D. This is the first evidence of the participation of microfilaments in the encystation process. Concentrations of cytochalasin D effective for the inhibition of encystation were lower than those effective for the inhibition of growth. Trophozoites grown with cytochalasin D became multinucleate; more than three nuclei per cell were observed in 71% of trophozoites grown in the presence of the drug as opposed to only 5% of those grown in the absence of the drug. Also, trophozoites grown with cytochalasin D produced multinucleate cysts following their transfer to encystation medium. Encystation with cytochalasin D was more strongly inhibited among trophozoites grown in the presence of the drug than among those grown in the absence of the drug. Also, encystation without cytochalasin D was less frequently observed among trophozoites grown in the presence of the drug than among those grown in the absence of the drug. Thus, the multinucleation of trophozoites induced by cytochalasin D had an inhibitory effect on their encystation.

Animals↗
PubMed2000

Effect of the antitubulin drug oryzalin on the encystation of Entamoeba invadens.

We have recently demonstrated that the antimicrotubule drug oryzalin inhibits the growth of Entamoeba invadens as well as E. histolytica, the former being more resistant to the drug than the latter, and that effective doses of oryzalin are higher for Entamoeba than for the other parasitic protozoa examined thus far. The aim of the present study was to examine the effect of oryzalin on the encystation of E. invadens using an axenic encystation system in vitro. Oryzalin inhibited the encystation of E. invadens strain IP-1 in a dose-dependent manner. The addition of oryzalin after the induction of encystation was also inhibitory for encystation and cyst maturation. Trophozoites incubated for 1 day in encystation medium with oryzalin did not encyst after removal of the drug. Although trophozoites grown in the presence of 300 microM oryzalin for 2 days did not encyst after their transfer to encystation medium containing the same concentration of drug, a number of trophozoites survived for at least 3 days. In contrast, trophozoites grown in the absence of oryzalin neither survived nor encysted after their transfer to encystation medium supplemented with the drug, which suggests that pretreatment of trophozoites with oryzalin contributes to their continued survival as trophozoites, i.e., without their transforming into cysts, in encystation medium. Trophozoites grown with oryzalin did encyst after their transfer to encystation medium without the drug. Accumulation of trophozoites in the mitotic phase was observed after culture with oryzalin. When cysts prepared at day 1 of encystation, most of which were mononucleate, were reincubated in the presence of oryzalin for an additional 2 days, inhibition of their maturation was observed. Thus, oryzalin is a potent mitotic-phase inhibitor of E. invadens and may become a useful tool for studies on the relationship between the cell cycle and encystation of this parasite.

Animals↗
PubMed2000

Differentially expressed mRNAs in androgen-independent but not androgen-dependent Shionogi carcinoma.

UNLABELLED: Recently, a new and highly effective method termed suppressive subtractive hybridization (SSH) has been introduced to clone differentially expressed mRNAs. Genes expressed in androgen-independent but not in androgen-dependent tumors, and vice versa, are obviously significant to delineate the mechanisms of androgen dependency/independency of these tumors. Mouse mammary cancer (Shionogi carcinoma-115) has been extensively used to analyze the mechanism of androgen-dependent cancer growth. METHODS: We cloned androgen-independent and androgen-dependent Shionogi carcinoma-115 specific mRNAs by the SSH method. Cloned sequences were compared with known sequences using NCBI BLAST across the Internet. Two clones were positive for cDNA insert when androgen-independent cDNA was used as tester cDNA, while no clones were positive using the androgen-dependent tester cDNA. One of the former was mouse protein kinase C beta-II while the other was a new DNA sequence. Mouse protein kinase C beta-II mRNA and the new mRNA were shown to be differentially expressed by RT-PCR analysis in androgen-independent but not androgen-dependent Shionogi carcinoma. Two mRNA species differentially expressed in androgen-independent but not androgen-dependent Shionogi carcinoma were cloned by the SSH method. The significance of these mRNAs for androgen-dependency/independency of Shionogi carcinoma should be explained in future studies.

Androgens↗
PubMed2000

Overexpression of cyclin D1 in nonmelanocytic skin cancer.

Although the overexpression of cyclin D1 has been believed to play important roles in neoplastic transformation of some tumors, little is known about the function of cyclin D1 protein in carcinogenesis in human skin. A total of 307 patients with nonmelanocytic skin cancer, being 46 with Bowen's disease (BOD), 134 with squamous cell carcinoma (SCC) and 127 with basal cell carcinoma (BCC), were investigated immunohistochemically using monoclonal antibody to cyclin D1 by the LSAB method, to assess the expression of cyclin D1 in skin cancer including its precursors. The positive rates of cyclin D1 immunostaining in BOD, SCC and BCC were 63.0%, 69.4% and 54.3%, respectively. The positive rates in dysplasia adjoining BOD, SCC and BCC were 43.6%, 67.9% and 59.8%, respectively. In morphologically normal skin, however, only 2 cases, 1 of SCC and 1 of BCC, exhibited positive staining. These findings suggested that overexpression of cyclin D1 is an early event in dysplastic lesions of skin. Overexpression of cyclin D1 was related to sun exposure, especially in dysplasia of SCC. The score for cyclin D1 expression in dysplasia of BCC was correlated with age. Expression of cyclin D1 markedly increased from normal skin through dysplasia to BOD, but was not significantly related to the degree of SCC differentiation. These findings demonstrate that the effect of cyclin D1 overexpression is restricted to proliferation of cells, so that they gain a growth advantage, but their differentiation is not increased. Comparison with the results for p53 protein expression in these tumors, a significant correlation with cyclin D1 expression was found in dysplasia in BOD and SCC, and in patients with BCC who were less than 74 years old. These findings suggested the hypothesis that prior aberrant p53 expression may affect or regulate the overexpression of cyclin D1.

Adult↗
PubMed2000

Appearance of a stage-specific immunodominant glycoprotein in encysting Entamoeba invadens.

The appearance of cyst-specific proteins in encysting Entamoeba invadens and their immunogenicity were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting using an axenic encystation system in vitro. A rabbit antiserum against trophozoites of E. invadens reacted with a number of proteins of cysts after 1-4 days of incubation. Thus, a number of cyst proteins remained antigenically unchanged as common antigens of the two forms after transformation from trophozoites to cysts. A rabbit antiserum against cysts also reacted with the trophozoite proteins as well as the cyst proteins. The most interesting result was that the rabbit anticyst serum reacted predominantly with an 88-kDa protein of cysts after 1 day of incubation. The 88-kDa protein reacted with the anticyst serum absorbed with trophozoite proteins and was thus cyst-specific. The reactivity of the 88-kDa protein of cysts with the absorbed anticyst serum decreased as encystation proceeded. When soluble and particulate fractions prepared from cysts after 1 day of incubation were examined by electrophoresis and immunoblotting, the 88-kDa protein that had reacted with the absorbed anticyst serum was found to be present in the particulate fraction, which was rich in cell-wall fragments, and stained with periodic acid-Schiff's reagent, indicating that it is a glycoprotein. The results indicate that encystation is accompanied by appearance of the cyst-specific 88-kDa glycoprotein, which is immunodominant and most abundantly expressed in cysts after 1 day of incubation and appears to be associated with the cyst wall.

Animals↗
PubMed2000

Basal leptin concentrations in women with normal and dysfunctional ovarian conditions.

OBJECTIVE: To determine whether leptin is involved in ovarian function. METHODS: Fasting serum samples were obtained from 20 women with normal menstrual cycles who were either obese or non-obese: 12 non-obese patients with polycystic ovary syndrome (PCOS), 8 obese patients with PCOS, 10 patients with stress-related hypothalamic amenorrhea, and 8 patients with weight loss-related hypothalamic amenorrhea. RESULTS: Serum leptin levels were strongly related to body mass index (BMI) in each group, but there was no difference in the mean serum leptin levels among the BMI-matched study groups. A significant difference in the mean serum leptin levels was found between the non-obese and obese control groups (P<0.001) and between the non-obese and obese PCOS groups (P<0.001). CONCLUSIONS: These findings indicate that circulating leptin levels in women with normal menstrual cycles and those with ovarian dysfunction are strongly related to BMI. Leptin does not appear to be primarily involved in regulating ovarian function.

Adult↗
PubMed2000

Distribution of alpha1-adrenoceptor subtype mRNA and identification of subtype responsible for renovascular contraction in human renal artery.

This study was intended to quantify the amounts of the alpha1-adrenoceptor subtype mRNAs in human renal artery and to demonstrate the distribution of receptor subtypes responsible for the contraction of the renal artery. RNase protection assay showed that the mean amount of alpha1a mRNA was much greater than that of alpha1b or alpha1d mRNAs in both the main and branch renal arteries. However, the abundance of alpha1a mRNA in human renal artery was much less than in our previous data in the prostate. In situ hybridization showed that all alpha1 subtype mRNAs were localized in the smooth muscle cells of the tunica media of the artery, and the distribution pattern of these three mRNAs in the main artery was the same as in the branch artery. However, the intensity of signals for alpha1d and alpha1b antisense RNAs probes was lower than that for the alpha1a antisense RNA probe. In the functional study, concentration-response curves to noradrenaline pretreated with KMD-3213, an alpha1A/L-adrenoceptor selective antagonist, seemed to be biphasic in nature. Chloroethyclonidine (CEC) failed to inactivate the noradrenaline-induced contraction, and prazosin showed relatively low affinity with a pA2 value of 8.8. These data suggest that the alpha1A/L-adrenoceptor mediates primarily those responses to noradrenaline in this artery. The other alpha1-adrenoceptor subtypes could also mediate the secondary contractile response to noradrenaline in this artery.

Adrenergic alpha-Antagonists↗
PubMed2000

Velocity discrimination in scotopic vision.

To characterize scotopic motion mechanisms, we examined how variation in average luminance affects the ability to discriminate velocity. Stimuli were drifting horizontal sine-wave gratings (0.25, 1.0 and 2.0 c/deg) viewed through a 2 mm artificial pupil and neutral density filters to produce mean adapting levels from 2.5 to -1.5 log photopic trolands. Drift temporal frequency varied from 0.5 to 36.0 Hz. Grating contrasts were either three or five times direction discrimination threshold contrasts at each adaptation level. Following 30 min adaptation, two drifting gratings were presented sequentially at the fovea. Subjects were asked to indicate which interval contained the faster moving stimulus. The Weber fraction for each base temporal frequency was determined using a staircase method. As previously reported, velocity discrimination performance was most acute at temporal frequencies of about 8.0 Hz and greater than 20.0 Hz (though there are individual differences), and fell off at both higher and lower temporal frequencies under photopic conditions. As adaptation level decreased, discrimination of high temporal frequencies in the central retina became increasingly worse, while discrimination of low temporal frequencies remained largely unaltered. The overall scotopic discrimination performance was best at about 3.0 Hz. These results can be explained by a motion mechanism comprising both low-pass and band-pass temporal filters whose peak and temporal cut-off shifts to lower temporal frequencies under scotopic conditions.

Adaptation, Ocular↗
PubMed2000

Modulation of perceived contrast by a moving surround.

The apparent contrast of a center pattern depends on the contrast of its surround. To examine the suprathreshold perception of moving patterns, we measured the perceived contrast of a moving grating while the direction and speed of the surround patterns varied. Subjects matched the apparent contrast of a center patch embedded in surround patches to that of a patch with no surround pattern. Temporal frequency, Michelson contrast and movement direction of both center and surround patterns varied systematically. We found that: (1) contrast reduction is most prominent when the center and surround have the same velocity (velocity selectivity); (2) contrast enhancement occurs when the surround moves at a higher speed than the center, if the difference in temporal frequencies of center and surround exceeds 10-20, independent of the directional relationship between center and surround; (3) contrast reduction is stronger for higher surround contrasts with lower center contrasts; and (4) contrast enhancement is relatively unaffected by center and surround contrasts. We conclude that the contrast perception of moving patterns is influenced by directionally-selective mechanisms except at high temporal frequencies. Our results further suggest that there is not only the lateral inhibition often assumed to influence contrast gain control, but also an excitatory connection between motion encoding units.

Contrast Sensitivity↗
PubMed2000

Tilt dependency of slant aftereffect.

Slant aftereffect (SAE), the negative aftereffect of slant induced after prolonged observation of a surface, is considered as evidence that slant is encoded in the visual system. Because slant and tilt are mathematically independent dimensions, Stevens (Stevens, K. A. (1983a). Biological Cybernetics, 46, 183-195) assumed that slant and tilt are processed independently in the visual system. To confirm this assumption, we investigated whether SAE is induced independently of the difference in tilt between the adapting and test stimuli. The stimuli were displayed by simulating the motion disparity of rotating disks. After adaptation to a surface of 60 degrees slant, the subjective 0 degree slants of the test stimulus were measured with the tilt differences of 0, 45, 90, 135 and 180 degrees. The magnitude of SAE was greatest when the tilt difference was zero, and decreased with increasing tilt difference. The results suggest that slant and tilt are not processed independently in the visual system and that the slant detector in the visual system is sensitive not only to slant but also to tilt.

Computer Simulation↗
PubMed2000

Sarcomatoid carcinoma of the urinary bladder: a clinicopathologic and immunohistochemical analysis of 14 patients.

Sarcomatoid carcinoma of the urinary bladder is a rare entity, in which both the histogenesis and biological behavior remain controversial. We herein describe the clinicopathologic and immunohistochemical profiles of sarcomatoid carcinomas and discuss the significance of cell adhesion molecules in the development of this peculiar neoplasm. The authors examined formalin-fixed and paraffin-embedded tissue samples from 14 patients with sarcomatoid carcinoma of the urinary bladder. An immunohistochemical analysis was performed by using antibodies against epithelial and mesenchymal antigens as well as adhesion molecules. Most patients suffered from an advanced stage of the tumor, extending to the muscular layer (7 cases) or to the perivesical tissues (5 cases). Microscopically, all 14 tumors were composed predominantly of a carcomatoid component and an obviously carcinomatous component. The sarcomatoid component was composed of a mixture of spindle cells, round cells, and pleomorphic giant cells. The carcinomatous components consisted of papillary or nonpapillary high-grade transitional cell carcinoma (TCC). The zones of gradual transition between the carcinomatous and the sarcomatous elements were focally apparent in each tumor. The findings of an immunohistochemical examination indicated that both carcinomatous and sarcomatoid components expressed epithelial antigens (pankeratin or EMA), even though the staining pattern varied from case to case. As for cell adhesion molecules, the carcinomatous components were positive for E-cadherin (8 of 12), CD44s (8 of 12), and CD44v6 (6 of 12). Although the sarcomatoid components were also positive for E-cadherin (5 of 12), CD44s (4 of 12), and CD44v6 (3 of 12), these rates were lower than those in the carcinomatous components. Six patients died of their disease between 5 and 36 months after the diagnosis was made. The recognition of sarcomatoid carcinomas has important therapeutic and prognostic implications. It seems appropriate to treat these neoplasms in the same manner as conventional high-grade TCCs with similar degrees of invasion. We consider that sarcomatoid carcinomas should be regarded as a high-grade carcinoma that shows a prominent pseudosarcomatous dedifferentiation. The sarcomatoid component of sarcomatoid carcinomas may result from either anaplastic changes or dedifferentiation related to the process of losing cell adhesion molecules.

Aged↗
PubMed2000

Facilitation of neurotransmitter release at the spiny lobster neuromuscular junction.

Stimulation-induced facilitation of transmitter release was examined at spiny lobster (Palinurus japonicus) neuromuscular junctions by measuring excitatory junctional potentials (EJPs). We found three components of facilitation with the decay time constants about 16, 200 and 1000 ms, respectively. The decay time constants of the nerve terminal free Ca(2+) concentration after stimulation agreed well with the two slower time constants of facilitation. The relationship among the three components of facilitation and a yet slower component, S, was investigated on the basis of several models. The models that have a multiplicative relationship between any two components of facilitation, and the additive model between all components could not account for the results of experiments. Only the 'unified power model', which assumes that facilitation and S are described by the 3-4th power of the sum of underlying components, could account for both the growth process of EJPs during stimulation and the effects of Ca(2+)-chelators. Loading Ca(2+)-chelators, BAPTA and EGTA, into the presynaptic terminals resulted in reduction, but not elimination, of any component of the facilitation. These results suggest that in the spiny lobster neuromuscular junction, the 'unified power model' can describe the relationship between three components of facilitation and S, and that residual free Ca(2+) enhances all three components of facilitation, although it may not be essential for them.

Animals↗
PubMed2000

Multinucleated giant cells in submucosal layer of human urinary bladder: an immunohistochemical and electron microscopic study.

Multinucleated giant cells (MGC) detected in the submucosal layer of human urinary bladder mainly associated with transitional cell carcinoma were examined immunohistochemically and ultrastructurally. The cases examined totaled 29, namely 14 cases with transitional cell carcinoma and another 15 cases mostly with malignancy in other organs. Histologically, MGC were smooth, irregular or dendritic in shape, and tended to increase in number in the vicinity of cancer or marked inflammation. They were consistently positive for not only vimentin, but also MB-2, and CD34, and were mostly positive for proliferating cell nuclear antigen (PCNA), but not MIB-1 (Ki-67) and HLA-DRalpha antigens. On occasion, antibodies to alpha-smooth muscle actin (alpha-SMA), muscle actin (M-actin), CD68 (KP-1) and alpha subunit of S-100 protein also yielded positive reactions. Interestingly, aggregated short bulbous processes were ultrastructurally observed on their surface in parts. These findings suggested that MGC in the submucosal layer of human urinary bladder were MB-2 and CD34-positive multipotential mesenchymal cells with no mitotic activity expressing fibroblastic (vimentin), myofibroblastic (alpha-SMA), or histiocytic (CD68) markers mostly in the vicinity of malignancy, and that these MGC were formed by fusion of mononuclear cells expressing identical markers with those of MGC. Further investigations are needed to clarify the exact function of MGC in human urinary bladder.

Adult↗
PubMed2000

Ultrasonographic evaluation of the influence of different postures on diaphragmatic motion in mechanically ventilated patients.

We confirmed a diaphragmatic motion during mechanical ventilation in four patients with central nervous system damage. The right hemidiaphragm were visualized with 3.5 MHz ultrasound, and motion was measured using time-motion analysis in separate postures. The dome was most impaired during the right decubitus posture. The crural region was most improving during the left decubitus posture. The costal region was most impaired during the sitting posture. The motion of the dependent region was impaired.

Adolescent↗
PubMed2000

gem-diamine 1-N-iminosugars of L-fucose-type, the extremely potent L-fucosidase inhibitors.

An efficient route from D-ribono-gamma-lactone to gem-diamine 1-N-iminosugars of L-fucose-type, a new family of glycosidase inhibitor, has been developed in a formation of a gem-diamine 1-N-iminopyranose ring by the Mitsunobu reaction of an aminal as a key step. The analogues were proved to be the extremely potent inhibitors against alpha-L-fucosidase (IC50 approximately 3 ng mL(-1), Ki approximately 5 x 10(-9) M). The present study has shown that a cyclic methanediamine generated in media affects glycosidases as a real active-form of the gem-diamine 1-N-iminosugars of L-fucose-type.

Carbohydrate Sequence↗