Biomedical subjects

H Kishi

Publications and source records attributed to H Kishi.

At least 19 recordsLinked to original sources

PubMed2005

Analysis of recessive lethality on swine chromosome 6 in a Göttingen miniature resource family.

Previously, we reported recessive gene(s) that terminate fetal development on swine chromosome (SSC) 6 between SW855 and SW122. The affected alleles originated from a Göttingen miniature pig used for construction of a Göttingen miniature pig x Meishan resource population. However, it is not known when the gene(s) are activated during fetal development, which is one of the important factors in selecting candidate genes responsible for fetal death. In the present study, a second swine population consisting of 159 progeny was produced by mating pigs carrying the deleterious allele(s). This population allowed us to narrow the genetic region harbouring the affected gene(s) and to demonstrate that the region was confined between RYR1 and SW782 (5.7 cM on the National Institute of Animal Industry (NIAI) map and 100 cR on the INRA/University of Minnesota porcine radiation hybrid panel map). In order to determine when the affected gene(s) are activated and in turn terminate fetal development, embryos produced in the second population were collected at several development stages and genotyped for markers in the region. Genes in the homozygous state affected embryo development between 9 and 11 days post-coitus.

Animals↗

PubMed2004

Orbital emphysema following nose blowing as a sequel of a snowboard related head injury.

A case of orbital emphysema as a sequel of a snowboard related head injury is reported. It is believed that a fracture of the medial orbital wall was caused by the increased intraorbital pressure when the patient hit his forehead on the snowy ground, allowing air to enter the orbit when he blew his nose. Wearing goggles may prevent this type of sports related injury.

Adult↗

PubMed2003

Transrectal colour Doppler ultrasonography for quantifying angiogenesis in prostate cancer.

OBJECTIVE: To assess the correlation between angiogenesis and Doppler signal intensity using transrectal colour Doppler ultrasonography (CDUS) in patients with prostate cancer. PATIENTS AND METHODS: The study comprised 56 patients who underwent radical prostatectomy and had untreated tumours with a volume of> 0.1 mL in the peripheral zone. CDUS images were recorded on videotape before surgery. The Doppler signal intensity in tumours was evaluated using the colour pixel intensity (PI). Microvessel density (MVD) and vascular endothelial growth factor (VEGF) immunoreactivity were determined in the prostatectomy specimens. Microvessels were identified by immunohistochemical staining of endothelial cells for CD31. RESULTS: The PI in the tumour correlated with MVD (P < 0.001) and increased with higher levels of VEGF immunoreactivity (P = 0.004). There was no correlation between Gleason score and MVD or PI in the tumour. CONCLUSION: Blood flow assessed by CDUS may reflect the state of angiogenesis in prostate cancer. CDUS may be a useful technique for predicting tumour progression or prognosis, and may be useful for monitoring the effects of anti-angiogenic agents in the future.

Adenocarcinoma↗

PubMed2002

Potential role of activin A in follicular development during the second half of pregnancy in the golden hamster: utero-placental source of activin A.

Numerous antral follicles develop during the second half of pregnancy in the golden hamster. However, mechanisms regulating follicular development during this period are unknown. Because inhibin and activin are related to follicular development, these hormones were studied to gain insight into any potential roles in follicular development. Plasma inhibin A and B suddenly increased from day 8 of pregnancy, reached peak levels on day 10 and gradually declined to term. Plasma activin A gradually increased from day 8 to day 15 of pregnancy, and this was followed by an abrupt decrease at day one of lactation. Ovariectomy on day 12 of pregnancy rapidly reduced plasma inhibin A and B, but not activin A levels. Hysterectomy or placentectomy on day 12 of pregnancy caused an abrupt decrease in the levels of plasma activin A and FSH, but not inhibin A and B at 6 h after surgery. Hysterectomy also induced atresia of large antral follicles at 24 h after surgery. These results indicate that antral follicles are the main source of circulating inhibin A and B, whereas uteri and placentae are the main source of circulating activin A. These results suggest that increased levels of activin A may be involved in folliculogenesis in the ovary during the second half of pregnancy in the golden hamster.

Activins↗

PubMed2002

Secretory pattern of inhibin A, inhibin B and inhibin pro-alpha C during induced follicular atresia and subsequent follicular development in the golden hamster (Mesocricetus auratus).

The changes in plasma concentrations of inhibins A, B and pro-alpha C were determined in the cyclic golden hamster during follicular atresia induced with antiserum against luteinizing hormone releasing hormone (LHRH-AS) at 1100 h on day 4 (day 1=day of ovulation). Follicular status in the ovary was also studied by determining the number of follicles ovulating in response to human chorionic gonadotrophin (hCG) injection. The time-courses of changes in plasma concentrations of inhibins A, B and pro-alpha C were different from each other during induced follicular atresia and subsequent follicular development. Plasma concentrations of inhibin A decreased to 58.6% of initial values by 24 h after LHRH-AS treatment, and then remained relatively low until at least 60 h later. Plasma concentrations of inhibin B decreased to 64.2% of the initial values by 18 h after LHRH-AS treatment and remained at basal values for 36 h, but increased abruptly to greater than initial values at 42 h after the treatment. Plasma concentrations of inhibin pro-alpha C increased at 6 and 12 h, decreased suddenly to 21.9% of the initial values by 24 h after LHRH-AS treatment, and then gradually increased until 60 h after LHRH-AS. The number of follicles responding to hCG decreased gradually between 0 and 30 h after LHRH-AS, when no ovulations were observed, and then gradually increased until 60 h. The changes in follicular ovulatory responses to hCG correlated with the plasma profile of inhibin A throughout the experiment. These results suggest that inhibin A is mainly secreted by large antral follicles. In contrast, during the subsequent follicular development, the plasma concentration of inhibin B increased earlier than that of inhibin A. These results suggest that inhibin B is secreted by small and large antral follicles. Plasma concentrations of inhibin pro-alpha C were high at a time when plasma concentrations of oestradiol-17 beta had already decreased, indicating that inhibin pro-alpha C is secreted not only from healthy follicles but also from early atretic antral follicles.

Animals↗

PubMed2001

The kinetics of allergen-induced eotaxin level in nasal lavage fluid: its key role in eosinophil recruitment in nasal mucosa.

Eotaxin (CCL11) is a potent eosinophil chemoattractant belonging to the C-C chemokine. To evaluate the role of eotaxin in eosinophilic inflammation in nasal mucosa, we investigated the levels of eosinophil chemoattractants in nasal lavage fluids obtained after antigen challenge, compared with eosinophil counts and eosinophil protein X (EPX) levels. In subjects with allergic rhinitis, allergen challenge led to parallel increases in eosinophil counts, levels of EPX, and eotaxin concentrations in nasal lavage fluid. The levels of eotaxin in lavage samples showed strong correlation with lavage levels of eosinophil counts and EPX. Normal subjects had few, if any, eosinophils and EPX as well as the measured parameters in their nasal lavage fluids before and after antigen challenge. In our experiments of eosinophil endothelial transmigration (TEM) assay using the nasal microvascular endothelial cells, eotaxin showed the most potent effect among various eosinophil chemoattractants. In addition, treatment of eosinophils with anti-CCR-3 mAb significantly blocked eosinophil TEM induced by homogenate of nasal mucosa. These results indicate that eotaxin has an important role in eosinophil-dependent inflammation in nasal mucosa and suggest that blocking eotaxin or CCR-3 might be useful for new therapeutic tools of allergic rhinitis.

Allergens↗

PubMed2001

Osmotic shock induces G1 arrest through p53 phosphorylation at Ser33 by activated p38MAPK without phosphorylation at Ser15 and Ser20.

Osmotic shock induced transient stabilization of p53, possibly due to increased degradation of Mdm2. Stabilized p53 was activated by p38(MAPK), resulting in G(1) arrest through induction of p21(WAF1). Among the postulated phosphorylation sites involved in p53 stabilization or activation (Ser(15), Ser(20), Ser(33), and Ser(46)), only Ser(33) was phosphorylated. Furthermore, interaction of p53 with the transcriptional coactivator p300 was induced, and Lys(382) of p53 was acetylated. Although inhibition of p38(MAPK) did not prevent nuclear accumulation of p53, phosphorylation of Ser(33) was markedly suppressed by SB203580, a specific inhibitor of p38(MAPK). Under these conditions, acetylation of Lys(382) and induction of p21(WAF1) were also inhibited, and cells with elevated levels of p53 showed normal cell cycle progression. Activated p38(MAPK) phosphorylated endogenous p53 at Ser(33) in living cells. In stable transformants expressing dominant negative MKK6, an upstream protein kinase of p38(MAPK), p53 stabilization was induced normally following osmotic shock, but phosphorylation of Ser(33), acetylation of Lys(382), and induction of p21(WAF1) were almost completely inhibited. These results suggest that phosphorylation at Ser(33) by p38(MAPK) is critical for activation of p53 following osmotic shock. Phosphorylation of neither Ser(15) nor Ser(20) was needed in this activation.

Acetylation↗

PubMed2001

Cross-talk between signal transducer and activator of transcription 3 and androgen receptor signaling in prostate carcinoma cells.

Interleukin 6 (IL-6) plays important roles in the immune system, hematopoiesis, as well as the growth of various tumors. Androgens are important in the initiation and progression of prostate cancer and their effects are mediated by androgen receptor (AR). Here we present a molecular mechanism for the effects of IL-6 on prostate cancer cells through a cross-talk between IL-6 and AR signaling pathways. IL-6-induced activation of signal transducer and activator of transcription 3 (STAT3) was augmented by AR in the presence of dihydrotestosterone (DHT). In addition, DHT treatment augmented endogenous STAT3-mediated gene expression by IL-6. Conversely, DHT-induced AR activity was increased by IL-6, and a dominant negative form of STAT3 inhibited AR activation. In contrast, DHT-mediated enhancement of STAT3 activation was inhibited by flutamide, an AR antagonist. We provide evidence that these activities are due to direct physical interactions between STAT3 and AR in prostate cancer cells.

Androgen Receptor Antagonists↗

PubMed2001

Hematopoietic cell-specific adapter proteins, SLP-76 and BLNK, effectively activate NF-AT as well as NF-kappaB by Syk and Tec PTKs in non-lymphoid cell lines.

To investigate the roles of various hematopoietic cell-specific adapter proteins in T cell receptor (TCR)-signaling leading to nuclear factor of activated T cell (NF-AT) and nuclear factor of kappaB (NF-kappaB) activation, we reconstituted TCR-signaling with CD8/zeta, various protein tyrosine kinases (PTKs), and adapter proteins in a non-lymphoid cell line, 293T. We show that SLP-76 and BLNK, but not LAT, effectively co-operated with Syk and Tec family PTKs to activate NF-AT and NF-kappaB. We also show that Tec family PTKs enhanced endogenous phospholipase C (PLC)-gamma1 phosphorylation induced by CD8/zeta and Syk in 293T cells. These results imply that PLC-gamma1 may play a critical role in a hematopoietic cell-specific adapter protein-mediated NF-AT and NF-kappaB activation in a non-lymphoid cell.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Differential involvement of p38 MAP kinase pathway and Bax translocation in the mitochondria-mediated cell death in TCR- and dexamethasone-stimulated thymocytes.

Mitochondria play a central role in many apoptotic reactions. Although mitochondrial apoptotic changes and caspase activation have been demonstrated in the apoptotic thymocytes, cell death signal through mitochondria in TCR-stimulated thymocytes has not been fully understood. In this study, we show that TCR stimulation induced disruption of mitochondrial transmembrane potential (Delta Psi(m)), the cytochrome c release from mitochondira, capase-3 activation, and the cell death of thymocytes. Bongkrekic acid, an inhibitor of Delta Psi(m) disruption, blocked the cytochrome c release from mitochondria and the following caspase-3-mediated cell death. Furthermore, a pro-apoptotic Bcl-2 family protein, Bax, but not Bad or Bid, was translocated from cytosol to mitochondria in TCR-stimulated thymocytes. This translocation and the following apoptotic changes were inhibited by SB203580, a p38 kinase inhibitor, in a specific manner. These results suggest that activated p38 kinase pathway by TCR stimulation induces translocation of Bax to mitochondria, causing Delta Psi(m) disruption, and the release of cytochrome c, which finally induces caspase-3-mediated apoptosis in thymocytes.

Animals↗

PubMed2001

Role of TGF-beta in the retinoic acid-induced inhibition of proliferation and melanin synthesis in chick retinal pigment epithelial cells in vitro.

The purpose of this study was to investigate the effects of all-trans retinoic acid (RA) on the induction of transforming growth factor-beta (TGF-beta) that is concerned with the proliferation and melanin synthesis of chick retinal pigment epithelial (RPE) cells in vitro. Chick RPE cells were cultured in the presence or absence of RA and anti-TGF-beta antibody for 7 days. The effects of RA and pan-specific TGF-beta antibody on RPE cell proliferation were assessed by counting the number of cells, and their effects on melanin synthesis were evaluated by measuring the melanin content of the cells. TGF-beta activity in the culture supernatant of RPE cells was measured using CCL-64 cells. RA significantly inhibited RPE cell proliferation and increased melanin synthesis. The addition of pan-specific TGF-beta antibody to the culture blocked the inhibition of RPE cell proliferation and the increased melanin synthesis. RA induced TGF-beta production in the culture supernatant of RPE cells. These findings indicate that RA regulates the proliferation and melanin synthesis of RPE cells via induction of TGF-beta.

Animals↗

PubMed2001

Expression of C-C chemokine TARC in human nasal mucosa and its regulation by cytokines.

BACKGROUND: Although interleukin (IL)-4 and IL-5 have been demonstrated to play a critical role in the pathophysiology of allergic diseases such as allergic rhinitis, the mechanism that causes the predominance of Th2 lymphocytes has yet to be clarified. Thymus and activation-regulated chemokine (TARC) has been known to facilitate the recruitment, activation and development of Th2 polarized cells, leading investigators to suggest a role for TARC in the development of Th2 responses. OBJECTIVE: To gain a better understanding of the role of TARC in the pathogenesis of allergic rhinitis we investigated the cellular sources of this chemokine in nasal mucosa. In addition, the effect of cytokines on TARC production has been investigated. METHODS: The expression of TARC in human nasal mucosa was assessed by immunohistochemistry. To study the effect of cytokines on TARC production, epithelial cells, endothelial cells and fibroblasts, isolated from inferior nasal mucosa samples, were stimulated by a variety of cytokines including IL-4, IL-13, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma. RESULTS: Epithelial cells in nasal mucosa in subjects with allergic rhinitis expressed higher signal level than those in non-allergy patients. Combined stimulation with IL-4 and TNF-alpha, as well as IL-13 and TNF-alpha, synergistically induced TARC expression in epithelial cells. Furthermore, the amount of TARC induced by these cytokines was higher in epithelial cells obtained from patients with allergic rhinitis than in those from non-allergic patients. CONCLUSION: These results demonstrate a crucial role of nasal epithelial cells in the expression of TARC, and that Th2 cytokine IL-4 and IL-13 may promote Th2 responses by inducing TARC production from epithelial cells.

Adolescent↗

PubMed2001

Myosin light chain kinase as a multifunctional regulatory protein of smooth muscle contraction.

Myosin light chain kinase (MLCK) is a regulatory protein for smooth muscle contraction, which acts by phosphorylating 20-kDa myosin light chain (MLC20) to activate the myosin ATPase activity. Although this mode of action is well-established, there are numerous reports of smooth muscle contraction that is not associated with MLC20 phosphorylation. The kinase activity for the phosphorylation is localized at the central part of MLCK, which is also furnished with actin-binding activity at its N terminal and myosin-binding activity at its C terminal. This article overviews as to how such multifunctional properties of MLCK modify the actin-myosin interaction and presents our observations that the phosphorylation is not obligatory in induction of smooth muscle contraction.

Actins↗

PubMed2001

[Determination of sucralose in foods by anion-exchange chromatography and reverse-phase chromatography].

Simple and rapid methods for the determination of sucralose in foods were developed using anion-exchange chromatography (AEC) with pulsed amperometric detection and reverse-phase HPLC with refractive index detection. Sucralose was extracted with water or methanol, and the extracted solution was cleaned up on a Sep-Pak C18 cartridge and a Sep-Pak Alumina N cartridge. The AEC separation was performed on a CarboPac PA1 column (4.0 mm i.d x 250 mm) using 100 mmol/L sodium hydroxide-50 mmol/L sodium acetate solution as the mobile phase at a flow rate of 1.0 mL/min. The recoveries of sucralose from foods were 80.6-102.0%, and quantitation limits from foods except chewing gum were 0.5 microgram/g (2 micrograms/g from chewing gum). The reverse-phase HPLC separation was performed on an Inertsil ODS-3V column (4.6 mm i.d x 150 mm) using methanol-water (25:75) as the mobile phase at a flow rate of 1.0 mL/min. The recoveries of sucralose from foods were 80.2-121.2%, and quantitation limits from foods except chewing gum were 5 micrograms/g (20 micrograms/g from chewing gum).

Chromatography, High Pressure Liquid↗

PubMed2001

[Determination method of isocitric acid in food additive citric acid].

A simple and rapid method using HPLC was developed for the determination of isocitric acid in food additive citric acid. One gram of sample was dissolved in 100 mL of water. HPLC separation was performed on an Inertsil ODS-3 column (4.6 mm i.d. x 250 mm) using 0.1% phosphoric acid as the mobile phase at a flow rate of 1 mL/min. Isocitric acid was detected at 210 nm. The calibration graph was rectilinear from 5 to 100 micrograms/mL. The recoveries of isocitric acid from sample at the levels of 0.1% and 0.4% were 98% and 99%, respectively, and the determination limit was 0.05%.

Chromatography, High Pressure Liquid↗

PubMed2001

[Treatment for brain metastasis from lung cancer in the era of radiosurgery].

OBJECTIVE: The treatment for brain metastasis has undergone remarkable changes since the development of radiosurgery. We investigated the results of treatment for brain metastasis from lung cancer since the initiation of gamma knife radiosurgery (GKRS) and we discuss the usefulness of GKRS combined with other treatments in cases with recurrence. METHODS: We treated 142 patients with brain metastasis from lung cancer. Sixteen patients were treated surgically, 11 patients were treated with whole brain radiation therapy (WBRT), and 115 patients were treated with GKRS. Our treatment plan is to use GKRS in cases with less than 5 lesions and lesions less than 3 cm in mean diameter. We use WBRT in cases with 5 or more lesions, and surgery in cases with lesions 3 cm or larger. If new lesions or tumor regrowth appeared after the initial treatment, we retreated them with one of the methods mentioned above. RESULTS: Twice or three-time treatments were performed in 30 patients. Median survival including all cases was 10 months and the number of deaths due to local treatment failure was only 5 (6.5%) out of the total 77 deaths which occurred. CONCLUSION: We were able to carry out less invasive treatment for brain metastasis from lung cancer by utilizing GKRS. Though we have to consider the indications for other treatments, we can say that radiosurgery is usually the treatment of first choice for brain metastasis from lung cancer. When new lesions appear in cases where a particular initial treatment was used, it is possible to maintain or improve the quality of life by retreatment, using a combination of GKRS, surgery or WBRT, to prolong the patient's life.

Adenocarcinoma↗

PubMed2000

Cross-talk between signal transducer and activator of transcription 3 and estrogen receptor signaling.

Interleukin-6 (IL-6) is a multifunctional cytokine that plays important roles in the immune system, hematopoiesis, and acute phase reactions. Estrogens have significant roles in a variety of biological events, such as the development and maintenance of female reproductive organs, and bone and lipid metabolism. Previous studies demonstrated that estrogens suppress IL-6-induced osteoporosis and the growth of multiple myeloma cells by repressing IL-6 and IL-6 receptor gene expression. Here we present a novel mechanism for the inhibitory effect of estrogens on IL-6 function. IL-6-induced activation of signal transducer and activator of transcription 3 (STAT3) activity and STAT3-mediated gene expression were suppressed by 17beta-estradiol (E2) in breast cancer cells. E2-mediated inhibition of STAT3 activation was reversed by tamoxifen, an estrogen receptor (ER) antagonist. We provide evidence that the inhibitory action of ER on STAT3 activity was due to direct physical interactions between STAT3 and ER which represents a novel form of cross-talk between STAT3 and ER signaling pathways.

Cell Line, Transformed↗

PubMed2000

Protein inhibitor of activated STAT3 regulates androgen receptor signaling in prostate carcinoma cells.

Protein inhibitor of activated STAT3 (PIAS3) is a specific inhibitor of signal transducer and activator of transcription 3 (STAT3). PIAS3 binds to STAT3 and inhibits its DNA-binding activity, and thereby STAT3-mediated gene activation. PIAS1, another member of the PIAS family, was recently shown to interact with the androgen receptor (AR), a nuclear hormone receptor that has an important role in both physiological and pathological processes, and acts as a cofactor for AR. Here we demonstrate that PIAS3 is expressed in prostate cancer cells and its expression is induced in response to dihydrotestosterone (DHT) treatment. Ectopic overexpression of PIAS3 suppressed AR-mediated gene activation induced by DHT-stimulation in LNCaP cells. We provide evidence that these activities were due to direct physical interactions between PIAS3 and AR. These results indicate that PIAS3 acts as a coregulator of AR signaling pathway in prostate cancer cells.

Blotting, Northern↗