Search PubMed⌕ Search

Biomedical subjects

Y Yoshimura

Publications and source records attributed to Y Yoshimura.

At least 109 records · Page 6Linked to original sources
PubMed2000

Gender specificity of tolterodine on micturition and the diurnal variation of urine production of the conscious rat.

OBJECTIVE: To evaluate the effect of the oral administration of tolterodine on the diurnal micturition characteristics of the male and female conscious rat, and to examine the relative effect of tolterodine in influencing water consumption and urine production. MATERIALS AND METHODS: Baseline micturition volume and frequency characteristics of nine male and 10 female Sprague-Dawley age-matched adult rats (body weight 399 +/- 15 and 249 +/- 3 g, respectively) were evaluated over 24-h. Initial hydration conditions were standardized with an oral dose (5 mL) of water. Rats were subsequently placed in a metabolic cage and had free access to water. Micturition volume/frequency characteristics were derived from the measurements of voided volume (measured using a digital balance below the metabolic cage and connected to a computer). The total volume of water consumed over the 24 h was also measured. Two separate baseline studies were conducted, followed by the administration of a single oral dose of 1 mg/mL of tolterodine dissolved in 5 mL of water. The mean frequency of micturition and mean volume voided per micturition were computed in 3-h periods and plotted over the 24-h period. In addition, the mean values of the number of micturitions and voided volumes during the day/dark cycle were evaluated. RESULTS: Baseline data showed that females (when corrected for body weight) consistently imbibed significantly more water (83%) than did male rats. Tolterodine did not significantly affect water consumption in the males but significantly reduced water consumption in females by 42%. Tolterodine did not significantly affect the amount of urine produced by male rats but significantly reduced the total amount of urine production in females by 26%. Tolterodine significantly increased the number of voids in male rats compared with baseline during the day but not during the night. More importantly tolterodine produce no significant effect on the volume voided per micturition in male rats either during the day or night cycle, but significantly decreased the volume voided per micturition in females. CONCLUSIONS: These results suggest that the effect of tolterodine on micturition is gender-specific, suppressing water consumption and urine production in female but not male rats, and decreasing bladder volume. There is a possibility that the reported clinical effects of tolterodine arise through the suppression of fluid consumption.

Animals↗
PubMed2000

Incidence of cleft lip or palate in 303738 Japanese babies born between 1994 and 1995.

To investigate the incidence of cleft lip or palate or both (CLP) in Japan, 303738 babies born in 1532 institutions between 1994 and 1995 were examined and 437 (0.14%) were found to have abnormalities. Of these babies, 32.1% had cleft lip, 43.3% had cleft lip and palate, and 24.8% had cleft palate (Table 2). These results show that the incidence of cleft lip and palate has declined compared with the period from 1981 to 1982.

Cleft Lip↗
PubMed2000

Expression of bone morphogenetic protein and its receptors in osteosarcoma and malignant fibrous histiocytoma.

BACKGROUND: Bone morphogenetic protein (BMP) activity has been found in cases of malignant fibrous histiocytoma (MFH) and osteosarcoma but only tumors in the latter category show evidence of ossification. The aim of this study was to try to understand this difference by examination of the distribution of BMP and its receptors (BMPR) for this bone inducing protein in these tumors. METHODS: Sections of 11 osteosarcoma and 10 MFH were analyzed immunohistochemically for BMP and BMPRs by use of the avidin-biotin peroxidase method. RESULTS: Nine out of 11 osteosarcoma cases (80.1%) showed positive staining for both BMP and BMPRs. Two cases of chondroblastic type osteosarcoma did not show any significant staining for BMP and BMPRs. In eight out of 10 MFH cases (80%) there was positive staining for BMP. No immunoreactivity for BMPRs was found in any case of MFH. CONCLUSIONS: MFH does not express BMPRs and this may be the reason why-MFH tumors do not ossify, even in the presence of BMP.

Bone Morphogenetic Proteins↗
PubMed2000

Immunolocalization of progesterone and estrogen receptors in the sperm storage tubules of laying and diethylstilbestrol-injected immature hens.

The goal of this study was to determine whether sperm storage tubules (SST) in the uterovaginal junction (UVJ) contain receptors for progesterone and estrogen (PR and ER) and whether estrogenic stimulation induces activation of these receptors in the SST. Frozen sections of UVJ obtained from immature chicks treated with or without diethylstilbestrol (DES), which is an estrogenic substance, and those from laying hens were immunostained for PR and ER. In laying hens, immunoreactions for PR were observed in the SST cells and on the surface epithelium of UVJ; the strongest reactions appeared in the SST cells. In contrast, ER immunoreactions were localized in the SST cells but not in the other cells. Immunoreactions for PR and ER were negligible in the UVJ of control immature birds that received only the oil vehicle. However, in the DES-treated birds, PR immunoprecipitates were localized in the surface epithelium and SST cells, and there were ER in the SST cells. These results suggest that the SST cells in the UVJ contain PR and ER, and estrogenic stimulation may play a significant role in inducing activation of these receptors.

Animals↗
PubMed2000

A monoclonal antibody to human SP-10 inhibits in vitro the binding of human sperm to hamster oolemma but not to human Zona pellucida.

SP-10 is a sperm intra-acrosomal protein, specific to the testis, that is believed to play an important role in egg-sperm binding. While the molecular characterization of the SP-10 protein has been clarified, little is yet known of its functional role in fertilization. We therefore established a monoclonal antibody (mAb pep-SP10) against a peptide (pep-SP10) that included the most hydrophilic portion of human SP-10 between the 135th and 149th amino acids. Human SP-10 was found to be localized in the equatorial region of acrosome-reacted sperm by immunofluorescent staining using our mAb pep-SP10. Monoclonal Ab pep-SP10 inhibited sperm-oolemma binding in the zona-free hamster egg penetration test, but it did not inhibit sperm-zona binding in the hemizona assay. Furthermore, we demonstrated that the oolemmal ligands of human SP-10 did not include beta(1) integrins, the most promising candidates for oocyte ligands involved in sperm-oolemma binding, based on the findings of a human sperm-cultured cell binding assay using F9 mouse embryonal carcinoma cells and F9-transformed cells lacking beta(1) integrins. In conclusion, our present data suggest that human SP-10, expressed on the equatorial region of acrosome-reacted sperm, indeed mediates sperm-oolemma binding in a beta(1) integrin-independent manner, but not sperm-zona binding.

Acrosome↗
PubMed2000

Isolation and characterization of a haploid germ cell-specific novel complementary deoxyribonucleic acid; testis-specific homologue of succinyl CoA:3-Oxo acid CoA transferase.

We have isolated a cDNA clone encoding a mouse haploid germ cell-specific protein from a subtracted cDNA library. Sequence analysis of the cDNA revealed high homology with pig and human heart succinyl CoA:3-oxo acid CoA transferase (EC 2.8.3.5), which is a key enzyme for energy metabolism of ketone bodies. The deduced protein consists of 520 amino acid residues, including glutamate 344, known to be the catalytic residue in the active site of pig heart CoA transferase and the expected mitochondrial targeting sequence enriched with Arg, Leu, and Ser in the N-terminal region. Thus, we termed this gene scot-t (testis-specific succinyl CoA:3-oxo acid CoA transferase). Northern blot analysis, in situ hybridization, and Western blot analysis demonstrated a unique expression pattern of the mRNA with rapid translation exclusively in late spermatids. The scot-t protein was detected first in elongated spermatids at step 8 or 9 as faint signals and gradually accumulated during spermiogenesis. It was also detected in the midpiece of spermatozoa by immunohistochemistry. The results suggest that the scot-t protein plays important roles in the energy metabolism of spermatozoa.

Amino Acid Sequence↗
PubMed2000

Steady-state plasma levels of nortriptyline and its hydroxylated metabolites in Japanese patients: impact of CYP2D6 genotype on the hydroxylation of nortriptyline.

The authors investigated the impact of the CYP2D6 genotype on steady-state concentrations of nortriptyline (NT) and its metabolites, trans-10-hydroxynortriptyline (EHNT) and cis-10-hydroxynortriptyline in a Japanese population of psychiatric patients. Forty-one patients (20 men and 21 women) were orally administered nortriptyline hydrochloride. The allele frequencies of the CYP2D6*5 and CYP2D6*10 were 4.9% and 34.1%, respectively. Significant differences in NT concentrations corrected for dose and weight were observed between the subjects with no mutated alleles and those with one mutated allele (mean +/- SD for no mutated alleles vs. one mutated allele: 70.3 +/- 25.4 vs. 98.4 +/- 36.6 ng/mL x mg(-1) x kg(-1); t = 2.54, dcf = 33, p < 0.05) and between the subjects with no mutated alleles and two mutated alleles (no mutated alleles vs. two mutated alleles: 70.3 +/- 25.4 vs. 147 +/- 31.1 ng/mL x mg(-1) x kg(-1); t = 5.87, df = 19, p < 0.0001). Also, a significant difference in the NT/EHNT ratio, which is representative of the hydroxylation ratio of NT, was observed between the subjects with no mutated alleles and those with two mutated alleles (no mutated alleles vs. two mutated alleles: 0.82 +/- 0.30 vs. 2.71 +/- 0.84; t = 7.86, df = 19, p < 0.0001). Multiple regression analysis showed that the number of mutated alleles of CYP2D6, which was the only significant factor, accounted for 41% and 48% of the variability in log(NT corrected for dose and weight) and log(NT/EHNT), respectively.

Adjustment Disorders↗
PubMed2000

Anti-paternal antibodies by flow cytometry in the management of alloimmunization on recurrent miscarriages.

PROBLEM: There is no reliable laboratory test available to diagnose immunologically mediated miscarriages. We investigated the clinical significance of maternal anti-paternal leukocyte antibodies by flow cytometry after alloimmunization. METHOD OF STUDY: The flow cytometry crossmatch (FCXM) was performed in 158 patients with a history of three or more unexplained first-trimester miscarriages without live birth. After negative FCXM patients were immunized, subsequent pregnancy outcomes and FCXM results were followed. RESULTS: Of 112 subsequent pregnancies, 83 of 100 (83.0%) FCXM-positive patients after immunotherapy had successful pregnancy outcomes, whereas seven of 10 (70.0%) FCXM-negative patients had miscarriages (P = 0.0001). The percent live birth ratio was 2.77 (CI, 1.07-7.16; P=0.0001) for FCXM-positive patients compared to FCXM-negative patients. The calculated predictive value showed that 75.6% of FCXM-negative patients would have subsequent miscarriages. CONCLUSIONS: Positive FCXM is closely associated with successful pregnancy outcome following immunotherapy. We propose that FCXM might be included in the routine laboratory tests for the management of recurrent miscarriages.

Abortion, Habitual↗
PubMed2000

Accurate multiplex polymerase chain reaction assay for gender determination from a single cell.

For gender determination of preimplantation embryos or circulating fetal cells in maternal blood, we developed a multiplex polymerase chain reaction assay from a single cell. This assay which co-amplifies X (DXZ1)- and Y (DYZ1)-specific repeat sequences, yields a 308-bp band in females and two bands of 154 and 308 bp in males. In a randomized, blinded assay of 100 isolated single amniocytes, 99 (99%) were amplified successfully. All 50 of the XY cells were correctly diagnosed as male (100%), whereas 49 of the 50 XX cells were diagnosed as female (98%). This accurate and efficient assay may be applicable in these clinical settings.

Amniotic Fluid↗
PubMed2000

Function of the small guanosine triphosphate-binding protein RhoA in the process of implantation.

The Rho family of small GTPases occupies a key position in the control of cell motility and morphology in response to extracellular stimuli. Rho proteins trigger the formation of contractile stress fibers, resulting in regulation of cell motility. We explored the expression and function of RhoA in human endometrium and decidua. RhoA immunoreactivity had a predominantly glandular epithelial distribution in the proliferative phase and midsecretory phase. In decidua, the expression of RhoA was more pronounced in the stromal cells as well as in the glandular epithelium. RhoA protein levels in proliferative phase and midsecretory phase endometrium as well as decidua were evaluated by immunoblotting; a single band of RhoA protein with a molecular mass of 21 kDa was detected in all cell lysates. Cultured human decidual cells were found to have few actin stress fibers. Decidual cells lost their actin stress fibers by the treatment with C3, an exoenzyme produced by Clostridium botulinum, whereas new actin stress fibers appeared in human decidual cells stimulated with lysophosphatidic acid (LPA). Mouse blastocysts became attached to cultured human decidual cells after embryos hatched from the zona pellucida. The majority of hatched blastocysts attached to human decidual cells within 24 h. Blastocysts attached to decidual cells exhibited extensive outgrowth after 48 h in culture. Treatment of decidual cells with C3 exoenzyme or LPA did not affect the rates of hatching and attachment of blastocysts, but outgrowth of embryos on decidual cells was inhibited by C3 exoenzyme treatment in a dose-dependent manner. Contrariwise, addition of LPA to decidual cells dose dependently increased the outgrowth of embryos on decidual cells. These findings suggest that RhoA in decidual cells is important for embryonic development and differentiation after attachment.

ADP Ribose Transferases↗
PubMed2000

Degradation products generated by sonication of benzyl alcohol, a sample preparation solvent for the determination of residual solvents in pharmaceutical bulks, on capillary gas chromatography.

Benzyl alcohol used as the sample preparation solvent in the determination of residual solvents in pharmaceutical bulks yielded benzene, toluene, and benzaldehyde on capillary gas chromatography (GC) by sonication. The factors responsible for compounds generated are discussed. The quality of benzyl alcohol and the type of sonicator were not involved in the generation of benzene, toluene, and benzaldehyde, whereas matrix contributions were observed. The degradation profiles of benzyl alcohol and its analogous compounds obtained by pyrolysis-GC/mass spectrometric analysis were similar to those obtained by sonication, suggesting that benzyl alcohol is degraded by the high local heat generated by sonication. Consequently, no matter how long it may take to dissolve bulk substances in benzyl alcohol completely, we do not recommend the use of a sonicator in sample preparation for the determination of residual solvents in pharmaceutical bulks.

Benzyl Alcohols↗
PubMed2000

Participation of reactive oxygen species in PGF2alpha-induced apoptosis in rat luteal cells.

Prostaglandin F(2alpha) (PGF(2alpha)) is implicated in the process of luteal regression in many species. Treatment of rat luteal tissue with PGF(2alpha) increases the generation of reactive oxygen species. Since reactive oxygen species have been implicated in apoptosis, the present study was undertaken to determine whether reactive oxygen species play a role in the PGF(2alpha)-induced apoptosis of rat luteal cells. Rat luteal cells were loaded with 6-carboxy-2, 7'-dichlorodihydro-fluorescein (CDCFH) diacetate, di (acetomethyl ester), which can be oxidized by reactive oxygen species to yield CDCF, a fluorescent molecule, and the cells were treated with different doses of PGF(2alpha). Incubation with 100 micromol PGF(2alpha) l(-1) induced an increase in CDCF fluorescence (P < 0. 05). Treatment of cells with PGF(2alpha) for 48 h in serum-free medium induced a dose-dependent increase in cell death, and these cells exhibited the morphological characteristics typical of apoptosis, including condensed or fragmented nuclei and fragmentation of internucleosomal DNA. Pretreatment of these cells with ascorbic acid, N,N'-dimethylthiourea, or superoxide dismutase, which acts as an antioxidant or a radical scavenger, prevented the PGF(2alpha)-induced apoptosis. These results demonstrate that PGF(2alpha) produces reactive oxygen species and induces apoptosis in rat luteal cells, indicating that the reactive oxygen species may induce apoptotic cell death during luteolysis.

Analysis of Variance↗
PubMed2000

Cyclic tension force activates nitric oxide production in cultured human periodontal ligament cells.

BACKGROUND: Nitric oxide (NO) is involved in a number of physiological and pathophysiological processes. The aim of this study was to examine the ability of human periodontal ligament (PDL) cells to produce NO and whether mechanical forces could induce NO production in the PDL cells. METHODS: Human PDL cells were seeded onto flexible bottoms of a culture plate and subjected to cyclic tension forces. NO production was evaluated by measuring concentration of NO2- and NO3- (NO2-/NO3-), the oxidized products of NO, in the culture medium. We employed reverse transcription polymerase chain reaction (RT-PCR) methods to detect NO synthase mRNA in the PDL cells. NO synthase immunoreactivity was also evaluated in both stimulated and unstimulated PDL cells. RESULTS: In unstimulated PDL cell culture, NO2-/NO3- increased to 140% of the initial value in 12 hours. In contrast, NO2-/NO3- showed a 3-fold increase when the cells had been subjected to cyclic tension forces for 12 hours. The increase in NO production was blocked by NG-monomethyl-L-arginine (5 x 10(-4) M), an inhibitor of NO synthase. Endothelial NO synthase (ecNOS) mRNA was expressed in both stimulated and unstimulated PDL cells, whereas inducible NO synthase (iNOS) mRNA was detected in neither culturing condition. We found strong ecNOS but not iNOS immunoreactivity in the stimulated PDL cells. CONCLUSIONS: These results suggest that human PDL cells produce NO by ecNOS and that the production is enhanced by stimulating the cells with cyclic tension forces. Mechanically stimulated PDL cells may modulate the function of periodontium by the upregulated NO production.

Adolescent↗
PubMed1999

Effect of extracellular calcium concentrations on osteoclast differentiation in vitro.

We have been researching with the purpose of understanding the hard organization mineralization-suppression mechanism under a low calcium environment. So far, we have discerned clearly that the femur of an incubated newborn rat under a low calcium environment will develop bone formation dyscrasia such as hypertrophy of the caput. In this experiment, MC3T3-E1 (E1) cells, which are osteoblast-like cells, and mouse bone marrow were incubated in a coculture system under a low calcium environment and manifestation of osteoblast cells and their ability to resorb were examined. The results suggested that as the calcium concentration in the medium decreased manifestation of osteoclast cells increased, and as the degree of mineralization of E1 cells advanced, the number of manifestation of osteoblast cells decreased. We, therefore, report that there is a possibility that extracellular calcium concentrations involve the process of differentiation of bone marrow cells into osteoblast cells.

3T3 Cells↗
PubMed1999

Application of liquid chromatography-turbo ion spray tandem mass spectrometry for quantitative analysis of a potent motilin receptor agonist, EM574, and its metabolites in human plasma.

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the simultaneous determination of a new potent motilin receptor agonist as erythromycin derivative, EM574 (erythromycin derivative), and its three metabolites, M-IV, M-V and M-VI, in human plasma was developed. The internal standards (I.S.s) used were deuterated EM574, M-IV and M-V. For the quantitation of M-VI, deuterated M-V was used. The analytes and I.S. were extracted from plasma samples with diethyl ether at neutral pH. A turbo ion spray interface was used as the ion source of LC-MS-MS, and the analysis was performed in the selected reaction monitoring mode. The lower quantitation limits for all the analytes were 0.05 ng/ml when 0.2 ml of plasma was used, and the standard curves were linear in the range 0.05 to 20 ng/ml. The method was precise; the intra- and inter-day precisions of the method were not more than 19.8% for all the analytes. The accuracy of the method was good with the deviations between added and calculated concentrations of each analyte being typically within +/- 11.2%.

Chromatography, Liquid↗
PubMed1999

A phosphotyrosine-containing quenched fluorogenic peptide as a novel substrate for protein tyrosine phosphatases.

Mca-Gly-Asp-Ala-Glu-Tyr(PO(3)H(2))-Ala- Ala-Lys(DNP)-Arg-NH(2), where Mca is (7-methoxycoumarin-4-yl)acetyl and DNP is 2,4-dinitrophenyl, was synthesized as a fluorogenic substrate for protein tyrosine phosphatases (PTPs). In the peptide, the fluorescent Mca group is quenched efficiently by the DNP group. Although the fluorescence intensity of the substrate was practically unchanged upon PTP-catalysed dephosphorylation, it increased approx. 120-fold upon subsequent treatment with chymotrypsin. Analysis by HPLC showed that chymotrypsin cleaved only the dephosphorylated substrate at the Tyr-Ala bond. Thus with the aid of chymotrypsin, dephosphorylation of the substrate can be measured fluorometrically. A strictly linear correlation was observed between PTP concentration and dephosphorylation rate. The fluorogenic substrate was dephosphorylated by some PTPs much more rapidly than the corresponding (32)P-labelled substrate used for comparison, whereas alkaline phosphatase dephosphorylated the two substrates at similar rates. The fluorogenic substrate is therefore more specific for PTPs than the radiolabelled substrate. The assay with the fluorogenic substrate could be applied to the estimation of kinetc parameters and measurement of PTP activity in crude-enzyme preparations. The lower detection limit of our assay (1 microM substrate in 200 microliter of reaction mixture) was estimated to be 0.2-0.4 pmol, whereas it was estimated to be about 1 pmol in the assay that used (32)P-labelled peptide (specific radioactivity of approx. 1000 c.p.m. /pmol). Our assay is simple, specific, highly sensitive and non-radioisotopic, and hence would contribute greatly to the development of PTP biology.

Animals↗
PubMed1999

Comparison of 1-(2-deoxy-2-fluoro-4-thio-beta-D-arabinofuranosyl)cytosine with gemcitabine in its antitumor activity.

The antitumor activity of a novel nucleoside, 1-(2-deoxy-2-fluoro-4-thio-beta-D arabinofuranosyl)cytosine (4'-thio-FAC) was compared with that of 2'-deoxy-2',2'-difluorocytidine (gemcitabine). 4'-Thio-FAC showed potent antitumor effects against various solid cancer cell lines in vitro. Also, gemcitabine showed remarkable in vitro antitumor effects, even more potent than 4'-thio-FAC. However, 4'-thio-FAC inhibited tumor growth more strongly than gemcitabine did at the same dose against human cancer cells implanted s.c. in nude mice. In addition, 4'-thio-FAC suppressed the tumor growth by oral administration. The toxicity of 4'-thio-FAC was weaker than that of gemcitabine in nude mice in both consecutive and intermittent administration. Accordingly, clinical usefulness of 4'-thio-FAC is expected.

Animals↗