PubMed Health⌕ Search

Biomedical subjects

Hiroko Ito

Publications and source records attributed to Hiroko Ito.

14 recordsLinked to original sources
PubMed2006

N-linked neutral oligosaccharides in the stratum corneum of normal and ichthyotic skin.

N-Glycan oligosaccharides are thought to play multiple, important roles in a variety of biological events. However, N-glycan profiles in the stratum corneum of human skin have not yet been studied in detail. To clarify the N-glycan profiles in the stratum corneum of normal and ichthyotic epidermis, N-glycan profiles were studied by high-performance liquid chromatography using normal human epidermal samples and scales from hyperkeratotic skin of ichthyosis patients. Chromatograms of patient scale samples showed unique alterations in three peaks eluted at 15.8, 18.8 and 26.9 min. The N-glycan profiles were significantly altered in ichthyotic hyperkeratotic skin compared with normal non-hyperkeratotic controls. These findings indicate the reduction of N-acetylglucosaminyltransferase II and fucosyltransferase 8 activities. Alteration of N-glycan structures in hyperkeratotic skin suggests the biological role of N-glycans in keratinization.

Chromatography, High Pressure Liquid↗
PubMed2006

Quantitative analysis of thermotaxis in the nematode Caenorhabditis elegans.

Thermotaxis (TTX) is one of the sophisticated behaviors in the nematode Caenorhabditis elegans. Although the mechanisms of thermotaxis have been deduced from different studies, they are controversial. Previous studies proposed a behavioral model where thermotaxis is regulated by the counterbalance between two opposite driving forces, while recent studies proposed stochastic models. In this study, we analyzed thermotaxis by a novel quantitative population TTX assay using a gentle linear thermal gradient. Analysis of thermotaxis in wild type animals revealed a clear thermal preference to a cultivation temperature with regard to the distribution of animals and the TTX mean expressing temperature preference. A time course assay revealed that the behavioral response to a preferred temperature was initially suppressed for at least 15 min in the animals cultivated at 23 degrees C, but not in those cultivated at 17 degrees C. Our result provides a possible explanation for the inconsistency between the various studies on thermotaxis and is consistent with the early behavioral model, where thermotaxis is regulated by the counterbalance between two driving forces.

Algorithms↗
PubMed2006

Identification of guanylyl cyclases that function in thermosensory neurons of Caenorhabditis elegans.

The nematode Caenorhabditis elegans senses temperature primarily via the AFD thermosensory neurons in the head. The response to temperature can be observed as a behavior called thermotaxis on thermal gradients. It has been shown that a cyclic nucleotide-gated ion channel (CNG channel) plays a critical role in thermosensation in AFD. To further identify the thermosensory mechanisms in AFD, we attempted to identify components that function upstream of the CNG channel by a reverse genetic approach. Genetic and behavioral analyses showed that three members of a subfamily of gcy genes (gcy-8, gcy-18, and gcy-23) encoding guanylyl cyclases were essential for thermotaxis in C. elegans. Promoters of each gene drove reporter gene expression exclusively in the AFD neurons and, moreover, tagged proteins were localized to the sensory endings of AFD. Single mutants of each gcy gene showed almost normal thermotaxis. However, animals carrying double and triple mutations in these genes showed defective thermotaxis behavior. The abnormal phenotype of the gcy triple mutants was rescued by expression of any one of the three GCY proteins in the AFD neurons. These results suggest that three guanylyl cyclases function redundantly in the AFD neurons to mediate thermosensation by C. elegans.

Amino Acid Sequence↗
PubMed2006

Developmentally retarded frozen blastocysts can be rescued by synchronizing culture prior to transfer.

Asynchrony between embryo development and endometrial differentiation is the limiting step of successful pregnancy in assisted reproduction. The aim of this study was to investigate whether or not post-thaw synchronization culture of day 5-6 frozen embryos, prior to transfer, with endometrial differentiation resulted in pregnancy. A total of 142 cycles of 134 patients were transferred in three protocols. Blastocysts with cavities larger than half of the entire blastocyst volume were transferred without synchronizing culture on day 5 or 6 of progesterone commencement (P5/6) in hormone replacement treatment cycles (protocol 1). Blastocysts with cavitation below half of the entire blastocyst were cultured for 1 or 2 days after thawing prior to transfer on P5 or P6 (protocol 2). Morulae and very early stage blastocysts were thawed on the days corresponding to P5 and P6, and only the embryos that reached expanded or hatching blastocysts were transferred on P7 without synchronizing culture (protocol 3). Pregnancy rate in protocol 2 (32.0%) was comparable with that of protocol 1 (35.0%). It is concluded that developmentally retarded frozen embryos can be rescued with synchronizing culture prior to transfer by evading asynchrony.

Adult↗
PubMed2006

Normal delivery following an uneventful pregnancy in a Japanese acromegalic patient after discontinuation of octreotide long acting release formulation at an early phase of pregnancy.

We report a 35-year-old woman with active acromegaly despite pituitary surgery and irradiation who received continuous octreotide LAR treatment for the control of GH excess until discovery of her pregnancy. The patient delivered a healthy boy following an uneventful pregnancy after discontinuing octreotide LAR as soon as possible at the early phase of pregnancy. Despite a substantial maternal-fetal transfer of octreotide, postnatal development was normal at 3 years of age. In almost all previously described cases, octreotide was discontinued after pregnancy was confirmed. No side-effects of mother or fetus have been reported. Octreotide treatment in pregnancy seems to be feasible and safe. Due to the still-limited number of reported cases treated with octreotide LAR, the potential benefits of octreotide LAR treatment should be weighed carefully against its possible risks.

Acromegaly↗
PubMed2006

Characterization of monoclonal antibodies against fowl adenovirus serotype 1 (FAV1) isolated from gizzard erosion.

Six clones of monoclonal antibodies (Mabs) to fowl adenovirus (FAV) serotype 1 were produced. All Mabs reacted positively by enzyme-linked immunosorbent assay. Three Mabs recognized the putative 100-kD hexon protein and reacted to serotype 1 specifically by western blot analysis but did not react to other FAV serotypes (2, 3, 4, 5, 6, 7, and 8a). These Mabs will be useful for immunodiagnosis of FAV serotype 1 infection in chickens with gizzard erosion and in further research studies involving the genomes and proteins of FAV serotype 1.

Animals↗
PubMed2005

Regulation of proliferation, motility, and contractility of human endometrial stromal cells by platelet-derived growth factor.

To evaluate the involvement of platelet-derived growth factor (PDGF) isoforms (PDGF-AlphaAlpha, PDGF-AB, and PDGF-BB) on endometrial tissue remodeling during the perimenstrual period, we investigated the effects of PDGF on the proliferation, motility, invasiveness, and contractility of cultured human endometrial stromal cells (ESC) using a modified methylthiazoletetrazolium assay, a 5-bromo-2'-deoxyuridine incorporation assay, an in vitro wound repair assay, a chemotactic migration assay, a Transwell invasion assay, and a collagen gel contraction assay. All three isoforms of PDGF significantly enhanced the cell proliferation, DNA synthesis, and in vitro wound repair of ESC. Chemotactic migration assay, Transwell invasion assay, and collagen gel contraction assay demonstrated that the PDGF isoforms significantly stimulated both the motility of ESC and the collagen gel contractility of ESC. PDGF-BB showed the strongest effects on these cellular functions of ESC. The present study suggested that PDGF isoforms may promote endometrial tissue repair by enhancing the proliferation and expansion of ESC, stimulating ESC migration, and stimulating the contraction of the collagen gel matrix by ESC. By regulating ESC function during the perimenstrual period, PDGF may help to protect the endometrium from extensive fibrosis and scarring.

Adult↗
PubMed2005

Human renal mesangial cells produce aldosterone in response to low-density lipoprotein (LDL).

Systemic aldosterone plays an important role in the development of the microvascular disease and glomerular damage of the kidney in patients with diabetes mellitus and hyperlipidemia. Here, we investigated the possibility of local production of aldosterone in the kidney, using human primary glomerular mesangial cells. These cells produced both pregnenolone and aldosterone measured by specific radioimmunoassay and/or gas chromatography/mass spectrometry (GC/MS) methods. The production of both steroids was significantly stimulated by treatment with LDL, while angiotensin II had a synergistic effect. Adrenocorticotropic hormone (ACTH) and (Bu)2cAMP, on the other hand, failed to stimulate aldosterone production by these cells, suggesting that the local production of this steroid by mesangial cells is regulated differently from that of adrenal zona glomerulosa cells. Mesangial cells expressed the mRNA of the LDL receptor and steroidogenic enzymes, such as P450scc, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 21-hydroxylase and CYP11B2. Mesangial cells also expressed mRNA of the mineralocorticoid receptor (MR), and LDL stimulated its abundance by three-fold, while spironolactone, a completive antagonist of aldosterone, completely abolished this LDL effect. Since MR is a known mineralocorticoid-responsive gene as well as an intracellular receptor molecule for this steroid, these results suggest that locally produced aldosterone is biologically active, stimulating the transcription rates of the mineralocorticoid-responsive genes by activating the MR in mesangial cells. These pieces of evidence indicate that human mesangial cells are an aldosterone-producing tissue in which LDL plays a major regulatory role. Therefore, human renal mesangial endocrine system may contribute to local aldosterone concentrations and effects in the renal glomerulus independently of the systemic renin--angiotensin--aldosterone system and may participate in the development and progression of glomerular damage in several pathologic conditions.

3-Hydroxysteroid Dehydrogenases↗
PubMed2005

Clinical usefulness of the thickness of preperitoneal and subcutaneous fat layer in the abdomen estimated by ultrasonography for diagnosing abdominal obesity in each type of impaired glucose tolerance in man.

For this study we enrolled 1,615 males who were admitted to our hospital for a general health check-up. Plasma glucose (PG) and insulin were measured during 75 g OGTT, and abdominal obesity was assessed by ultrasonography in all subjects. We divided them into several groups: normal glucose tolerance (NGT), high-normal glucose tolerance (h-NGT) who showed >10.0 nmol/l at 1 hr PG among those with NGT, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), IFG + IGT, and DM, according to the results of 75 g OGTT. The aim of the present study was to clarify the clinical characteristics of pre-diabetic disorders relating to metabolic syndrome by comparing various parameters including body mass index (BMI), blood levels of various lipids and abdominal wall fat index (AFI) calculated from the thickness of preperitoneal (Pmax) and subcutaneous (Smin) fat layer in the abdomen estimated by ultrasonography with insulin sensitivity determined by homeostatic model assessment (HOMA-IR) in each type of abnormal glucose regulation as classified by PG changes in 75 g OGTT. We also investigated the relationship between insulin secretion capability and insulin sensitivity to delineate the characteristics of each type of abnormal glucose regulation, and compared the area under the insulin curve (AUCins) and the time axis, and the ability of early insulin secretion by glucose loading (insulinogenic index: I.I.) in each type of abnormal glucose regulation. There was a significant positive correlation between HOMA-IR and Smin or Pmax, suggesting that Smin and Pmax may reflect insulin sensitivity. Abdominal obesity, which was diagnosed from the data of AFI, was present in the h-NGT and IFG + IGT groups, suggesting that those groups belong to the clinical entity of metabolic syndrome. HOMA-IR was higher in IFG than in IGT, although I.I. was reduced and AUCins was increased in IFG as well as in IGT. h-NGT demonstrated a slightly lower I.I. and higher AUCins, compared with IGT. IFG demonstrated much stronger insulin resistance than IGT, although I.I. was reduced and AUCins was increased in IFG and IGT. Thus, it is suggested that insulin sensitivity may partly account for the difference in pathogenesis between IFG and IGT; and that h-NGT, which showed abdominal obesity assessed as AFI by ultrasonography, should be recognized as a disease state of metabolic syndrome with impaired glucose regulation.

Abdomen↗
PubMed2004

Rapid cell senescence-associated changes in galactosylation of N-linked oligosaccharides in human lung adenocarcinoma A549 cells.

Rapid senescence was induced into human lung adenocarcinoma A549 cells by transforming growth factor-beta1. Lectin blot analysis of membrane glycoprotein samples showed that the binding of Ricinus communis agglutinin-I to protein bands increased markedly while those of other lectins together with protein components did not change significantly with senescence. This indicates that the beta-1,4-galactosylation of N-linked oligosaccharides is stimulated by rapid senescence. Analysis of the enzymatic background of senescence showed 1.5 times higher beta-1,4-galactosyltransferase (beta-1,4-GalT) activity and 2-5 times higher expression levels of beta-1,4-GalT II, III, V, and VI genes are associated with rapid senescence. Incubation of the cells on RCA-I-coated plates in the absence of fetal calf serum showed that the viability of the senescent cells is half that of the control cells. Therefore, it is hypothesized that galactose residues expressed by rapid senescent can induce a lethal signal in cells if they interact with appropriate receptors.

Adenocarcinoma↗
PubMed2004

A prospective, randomized study: day 3 versus hatching blastocyst stage.

BACKGROUND: Recently, advances in human IVF-embryo transfer (ET) have been reported using sequential media and blastocyst stage ET. In our previous report, using a prospective, randomized study, no advantage was found using the blastocyst stage ET compared with day 3 ET. This study was performed in order to evaluate implantation and pregnancy rates of hatching blastocyst stage ET compared with conventional day 3 ET. METHODS AND RESULTS: A total of 480 patient cycles were evaluated using a prospective, randomized study. The pregnancy rate and implantation rate were compared between the day 3 ET (n = 240) and hatching blastocyst stage ET (Hat ET; n = 240). The Hat ET group had a pregnancy rate of 29.3% (55 out of 188) and an implantation rate of 21.4% (67 out of 313). The day 3 ET group had a pregnancy rate of 29.2% (70 out of 240) and an implantation rate of 19.1% (93 out of 488). In the Hat ET group, the pregnancy rate, implantation rate and ongoing pregnancy rate of day 5 ET and day 6 ET were all higher than the respective rates in the day 7-9 ET group. CONCLUSION: We found that the pregnancy rate and implantation rate of ET with hatching stage blastocysts had no advantage compared with the conventional day 3 ET.

Adult↗