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Miho Sato

Publications and source records attributed to Miho Sato.

At least 19 recordsLinked to original sources
PubMed2006

Effects of ghrelin and des-acyl ghrelin on neurogenesis of the rat fetal spinal cord.

Expressions of the growth hormone secretagogue receptor (GHS-R) mRNA and its protein were confirmed in rat fetal spinal cord tissues by RT-PCR and immunohistochemistry. In vitro, over 3 nM ghrelin and des-acyl ghrelin induced significant proliferation of primary cultured cells from the fetal spinal cord. The proliferating cells were then double-stained using antibodies against the neuronal precursor marker, nestin, and the cell proliferation marker, 5-bromo-2'-deoxyuridine (BrdU), and the nestin-positive cells were also found to be co-stained with antibody against GHS-R. Furthermore, binding studies using [125I]des-acyl ghrelin indicated the presence of a specific binding site for des-acyl ghrelin, and confirmed that the binding was displaced with unlabeled des-acyl ghrelin or ghrelin. These results indicate that ghrelin and des-acyl ghrelin induce proliferation of neuronal precursor cells that is both dependent and independent of GHS-R, suggesting that both ghrelin and des-acyl ghrelin are involved in neurogenesis of the fetal spinal cord.

Animals↗
PubMed2006

Purification and characterization of feline ghrelin and its possible role.

Ghrelin, a novel 28-amino acid peptide with an n-octanoyl modification at Ser3, has been isolated from rat and human stomach as an endogenous ligand for the growth hormone secretagogue receptor. Here, we purified feline ghrelin and examined its possible physiological role in cats. The major active form of feline ghrelin is a 28-amino acid peptide octanoylated (C8:0) at Ser3; except for one amino acid residue replacement, this structure is identical to those of rat and human ghrelins. However, much structural divergence in peptide length and fatty acid modification was observed in feline ghrelin: peptides consisting of 27 or 26 amino acids lacking Gln14 and/or Arg28 were found, and the third serine residue was modified by octanoic acid (C8:0), decanoic acid (10:0), or unsaturated fatty acids (C8:1, C10:1 and C10:2). In agreement with the structural divergence, two kinds of cDNA with different lengths were isolated. Administration of synthetic rat ghrelin increased plasma growth hormone levels in cats, with a potency similar to that in rat or human. Plasma levels of ghrelin in cats increased approximately 2.5-fold after fasting. The present study indicates the existence of structural divergence in feline ghrelin and suggests that, as in other animals, ghrelin may play important roles in GH release and feeding in cats.

Amino Acid Sequence↗
PubMed2005

Maternal ghrelin plays an important role in rat fetal development during pregnancy.

Ghrelin, an acylated peptide serving as an endogenous ligand for GH secretagogue receptor (GHS-R), was originally isolated from rat and human stomach. In this study, we report the critical role of maternal ghrelin in fetal development. High levels of ghrelin receptor (GHS-R) mRNA were detected in various peripheral fetal tissues beginning at embryonic d 14 and lasting until birth. Fetal GHS-R expression was also confirmed in fetal tissues by immunohistochemistry. Autoradiography revealed that both des-acyl ghrelin and acyl ghrelin bind to fetal tissues. Chronic treatment of mothers with ghrelin resulted in a significant increase in birth weight in comparison to newborns from saline-treated mothers. Even when maternal food intake after ghrelin treatment was restricted through paired feeding, significant stimulation of fetal development still occurred. Conversely, active immunization of mothers against ghrelin decreased fetal body weight during pregnancy. A single ghrelin injection into the mother increased circulating ghrelin levels in the fetus within 5 min of injection, suggesting that maternal ghrelin transits easily to the fetal circulation. High levels of des-acyl ghrelin were detected in fetal blood and amniotic fluid. Both acylated and des-acyl ghrelin increased [3H]thymidine and 5-bromo-2'-deoxyuridine incorporation of cultured fetal skin cells in a dose-dependent manner, and calcium-imaging analysis revealed that acyl and des-acyl ghrelin increased the Ca2+ influx in discrete cultured fetal skin cells, respectively. These results indicate that maternal ghrelin regulates fetal development during the late stages of pregnancy.

Amniotic Fluid↗
PubMed2005

Early detection of thinning of retinal nerve fiber layer in glaucomatous eyes by optical coherence tomography 3000: analysis of retinal nerve fiber layer corresponding to the preserved hemivisual field.

The retinal nerve fiber layer (RNFL) thickness was measured with the optical coherence tomography using version 3.0 software (OCT3000) in 153 eyes of 153 normal subjects. The mean of the average RNFL thickness over the entire 360 degrees in the control group was 92.5 +/- 12.9 microm which was significantly thinner than the normative data of 95.9 +/- 11.4 microm included with the OCT3000 (p < 0.01). The RNFL thickness decreased with increasing age (p < 0.01, r = -0.395). The RNFL thickness was also measured in 53 eyes of 53 patients with glaucoma whose superior (13 eyes) or inferior (40 eyes) perimetric hemifields were normal. Only the RNFL thickness corresponding to the preserved perimetric hemifields were measured by OCT3000 and scanning laser ophthalmoscopy (SLO). The RNFL thickness in the superior and inferior 30 degrees sectors, the maximum and average RNFL thickness in the superior (S(max) and S(avg)), and inferior quadrants (I(max) and I(avg)) were analyzed. The S(max), S(avg), I(max), I(avg), and the RNFL thickness in the superior (p < 0.05), superotemporal and inferotemporal sectors (p < 0.01) in the glaucoma patients without a nerve fiber layer defect (SLO) were significantly thinner than in the control subjects in same age. OCT3000 measurements showed that the RNFL thickness in glaucomatous eyes with normal perimetric visual fields and SLO was significantly thinner than the RNFL thickness in normal eyes.

Adult↗
PubMed2005

Effect of neuromedin S on feeding regulation in the Japanese quail.

Neuromedin S (NMS) was recently isolated from the brains of humans, mice and rats as an endogenous ligand for the orphan G protein-coupled receptors FM-3 and FM-4, which have been identified as neuromedin U (NMU) receptors 1 and 2, respectively. To investigate the role of NMS in avian species, we elucidated the effect of intracerebroventricular (i.c.v.) administration of rat NMS on food intake, body weight, body temperature and gross locomotor activity in adult Japanese quails. NMS significantly decreased food intake (and consequently body weight) in a time-dependent manner during 12-h light period, but increased both body temperature and gross locomotor activity. On the other hand, i.c.v. injection of rat NMU showed the reverse effects of NMS in Japanese quail. These results suggest that NMS may play an important role in regulating food intake and sympathetic nerve activity in the Japanese quail.

Animals↗
PubMed2005

Multicentric atypical teratoid/rhabdoid tumors occurring in the eye and fourth ventricle of an infant: case report.

Atypical teratoid/rhabdoid tumors (AT/RTs) are aggressive malignant tumors found in infants and young children. The tumor is characterized by the presence of a rhabdoid cell component in all cases, but the histological origin is still unclear. Recently, germline mutation of the hSNF5/INI1 gene has been reported in association with AT/RTs. The authors report a rare case of an intraocular AT/RT followed by a fourth ventricular tumor. The results of immunohistochemical studies of the surgical specimens revealed the presence of an AT/RT and from this finding the neural origin was inferred. A novel missense mutation of the hSNF5/INI1 gene was demonstrated by DNA analysis. High-dose chemotherapy with stem cell rescue was effective in treating this patient. The immunohistochemical relationship between rhabdoid cells and the neurogenic zone, which has not been described in AT/RTs, is of great interest in view of the nature of rhabdoid cells.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Bagolini striated glasses test and lesions of the optic chiasm.

PURPOSE: To examine the usefulness of the Bagolini Striated Glasses Test to identify patients with a lesion of the optic chiasm. SUBJECTS AND METHODS: Twelve patients who were diagnosed with a lesion of the optic chiasm by MRI were examined with the Bagolini Striated Glasses Test. Discrepancies of the test between monocular and binocular conditions were analyzed. Visual acuity, visual field and stereo tests were also administered and assessed. RESULTS: Nine out of 12 cases (75%) showed conflicting results with the Bagolini Striated Glasses Test between monocular and binocular conditions. With monocular testing, essentially normal stripes were observed in each eye. In binocular testing, stripes which were projected upon nasal retina were suppressed bilaterally (bitemporal hemianopia pattern) ("mountain pattern") or monocularly (monocular temporal hemianopia pattern). CONCLUSION: The Bagolini Striated Glasses Test can be used as a simple differential diagnostic test for lesions of the optic chiasm. The "mountain pattern" seen binocularly on this test may be pathognomonic for such lesions, which may otherwise be asymptomatic and/or overlooked.

Adenoma↗
PubMed2005

Similar etiologies of functional visual loss observed in children and adults.

BACKGROUND AND PURPOSE: To describe four cases of functional visual loss which challenge the theory that its causes are different in children and adults (i.e., that financial gain is the primary cause in adults while in children it is an involuntary response to psychosocial problems). Rather, we will show a similar etiology of functional visual loss in children and adults. We also describe diagnostic testing and therapeutic approaches that are useful in both children and adults with functional visual loss. SUBJECTS AND METHODS: Two children (5 and 15 years old) and two adults (54 and 73 years old) with presumed functional visual loss and whose visual functions were assessed with verbal assurance, Starlight Test, Flicker Test, and trial glasses or contact lenses. RESULTS: Normal visual function was elicited in all four cases. In both pediatric patients we were able to elicit normal vision using verbal assurance and trial glasses or contact lenses. In both adult patients, we elicited dramatic improvements in vision with verbal assurance and discussion of the patients' psychosocial situation. CONCLUSION: Children and adults present with similar etiologies (psychosocial problems) of functional visual loss. In these cases we believe the children were motivated by their desire to wear glasses or contacts and the adults were involuntarily responding to psychosocial problems. These cases show that we cannot, as has been proposed, clearly categorize patients with functional visual loss based upon age.

Adolescent↗
PubMed2004

The remnants of crossed fixation observed in teenaged children with esotropia.

PURPOSE: To report 2 cases of teenage children with esotropia from a much earlier age, displaying remnants of crossed fixation with special reference to Helmholtz's theory that each eye is controlled independently and Hering's Law of equal innervation. CASE REPORTS: Case 1 had paretic and partially accommodative esotropia that was first observed at 11 months of age; and Case 2 had accommodative esotropia with an onset at age 3 years. Both cases had hypermetropia and good corrected visual acuity in both eyes. They were able to fixate independently with each eye but the dominant eye always controls their fixation and they believe they are using only their dominant eye; however, their non-dominant eye was used to viewing objects in the opposite field (crossed fixation). Both cases maintained good binocular alignment at distance with either surgery and glasses (Case 1) or glasses alone (Case 2). However, their esotropia increased through the early teenage years leading both patients to undergo surgery at this later age: Case 1 at 17 years of age and Case 2 at 19 years of age. Post-surgical Starlight testing showed that their binocular visual fields improved. CONCLUSION: Crossed fixation exists in esotropia (even in acquired accommodative esotropia) and as the patient ages, one eye becomes dominant leaving the non-dominant eye to fix only in crossed gaze. These cases support Helmholtz's theory that each eye is controlled independently and that binocular coordination is learned.

Accommodation, Ocular↗
PubMed2004

Dynamic aniseikonia measurement: prismatic effect appears on the hess chart.

PURPOSE: To determine if aniseikonia appears on the Hess [Screen] Chart and if it can be measured thereby; and to compare such measurement to the standard Awaya New Aniseikonia Test in both artificial and pathologic aniseikonia. SUBJECTS AND METHODS: Twenty normal subjects with 20% artificial induced aniseikonia (Group 1) and 21 patients with pathologic aniseikonia (Group 2) were examined with the New Aniseikonia Test (NAT) and the Hess Chart. Group 2 was divided into three subgroups: Group 2-1, 13 patients with aphakia, whose operated eyes were more hypermetropic that their better eyes; Group 2-2, 3 patients with myopic anisometropia more than 5 diopters; and Group 2-3, 5 patients who had received macular translocation surgery (MTS). RESULTS: In normals, measurement of the 20% artificial aniseikonia ranged from 10% to 21% (mean 15%) using the NAT, and from 16% to 39% (mean 27.1% vertically and 24.6% horizontally) using the Hess Chart. In the 21 patients with pathologic aniseikonia, the NAT measurements ranged from 0% to 24% (upper limit of the NAT) and the Hess Chart measurements ranged from 0% to 65%. A large amount of the aniseikonia that appeared on the Hess Chart disappeared or was significantly reduced by changing the spectacle correction to a contact lens or intraocular lens. CONCLUSION: The aniseikonia that appeared on the Hess Chart was dynamic aniseikonia, due to rotational magnification inherent and unavoidable in the execution of the aniseikonia measurement on the Hess Chart. Aniseikonia, not due to refractive errors brought on by retinal surgery such as MTS, is difficult to correct with iseikonic lenses or other optical means.

Adolescent↗
PubMed2003

Urinary beta 2-microglobulin in premature infants with chorioamnionitis and chronic lung disease.

The urinary beta(2)-microglobulin (MG) concentration on day 0 to 2 was significantly higher in premature infants with chorioamnionitis (CAM) than in infants without CAM and in infants who developed chronic lung disease (CLD) than in those who did not. We propose that an elevated urinary beta(2)-MG can indicate a fetal inflammatory response and identify neonates at risk for the development of CLD.

Chorioamnionitis↗
PubMed2003

Chronic angle closure glaucoma secondary to frail zonular fibres and spherophakia.

PURPOSE: We describe a 39-year-old Japanese woman with chronic angle closure glaucoma secondary to spherophakia and frail zonular fibres. The patient was 143 cm in height with short fingers and had no family history of eye problems. High intraocular pressure, total optic disc cupping and severe visual field constriction were found in the right eye. METHODS: The patient was treated successfully with trabeculectomy in the right eye and laser iridotomy in the left eye. CONCLUSION: The clinical findings imply that this was a borderline case of Weil-Marchesani syndrome.

Adult↗
PubMed2003

Strabological findings after macular translocation surgery with 360 degrees retinotomy.

PURPOSE: To examine the strabological findings after macular translocation surgery with a 360 degrees retinotomy. METHODS: Thirty-two patients who underwent macular translocation surgery were divided into three groups based on their responses to the Bagolini striated lenses test: fusion, ignoring the image, and diplopia. The relevant factors affecting binocularity were compared among the three groups. RESULTS: Five patients had peripheral fusion and three of these had gross stereopsis. Fifteen patients ignored the second image, and 12 patients had diplopia. The objective angle of macular rotation was smaller in the patients with peripheral fusion (15.0 +/- 6.1 degrees) than in those with diplopia (32.7 +/- 11.7 degrees). The subjective angle of cyclotorsion in those with peripheral fusion (6.0 +/- 4.2 degrees) was smaller than in those who ignored the image ("ignoring" group; 20.5 +/- 9.19 degrees) and the diplopia group (30.7 +/- 12.8 degrees). The amount of torsional sensory compensation in patients with diplopia (2.08 +/- 3.83 degrees) was significantly smaller than in those with peripheral fusion (9.00 +/- 7.42 degrees) and in the ignoring group (6.73 +/- 3.86 degrees). Patients with peripheral fusion were significantly younger (54.2 +/- 14.3 years) than those in the ignoring group (67.7 +/- 10.0 years) and those with diplopia (68.0 +/- 5.4 years). CONCLUSIONS: Adaptive mechanisms are activated to reduce the surgically induced objective angle of cyclotorsion, and a cyclodeviation of 15 degrees was the critical angle separating those who had peripheral fusion from those who did not. This value corresponds to the cyclofusional amplitude in normal adults.

Activities of Daily Living↗
PubMed2003

Stereopsis in idiopathic macular hole with special reference to the size of the hole and its effect on stereoacuity.

PURPOSE: To identify the characteristics of binocular vision in unilateral idiopathic macular hole (MH) regarding the size of the hole and its effect on stereopsis. SUBJECTS AND METHODS: Twelve patients with idiopathic MH were tested using the Amsler Grid, Bagolini Striated Glasses, Starlight Test, Titmus Stereotest (the Titmus) and Lang Stereotest (the Lang). The results were analyzed with reference to two parameters: visual acuity and the size of the MH. RESULTS: The size of the MH in 12 subjects ranged from 0.67 degrees to 2.13 degrees (mean, 1.29 degrees). The MHs caused distorted central vision under binocular conditions. Visual acuities ranged from 0.3 to 0.06. Nine out of the 12 patients (75%) failed the 800 seconds of arc (") with the Titmus, but all 12 patients (100%) demonstrated stereoacuity of 550" to 600" with the Lang. CONCLUSION: The discrepancy of measured stereoacuity between the Titmus and the Lang was hypothesized to be due to the different size of the test charts and their targets and the pattern of the visual deficit. The pass rate of 92% (550") with the Lang is better than rates for other patients with higher visual acuities, such as children with amblyopia (62-70%) or adults undergoing visual screening (67%). In cases of MH, intact overlapped visual field beyond the central 0-2 degrees played an important role in maintaining stereoscopic vision.

Aged↗
PubMed2002

Loss of stereopsis with optic chiasmal lesions and stereoscopic tests as a differential test.

OBJECTIVE: To identify and characterize the loss of stereopsis observed in patients with lesions of the optic chiasm. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Forty-three patients who had good visual acuity with orthophoria and without strabismologic histories were divided into two groups. Group 1 consisted of 13 patients with lesions involving the optic chiasm (regardless of their visual field loss) diagnosed by magnetic resonance imaging findings. Group 2 (control group) consisted of 30 patients who had large absolute visual field defects as a result of other causes, including 11 intracranial disorders other than optic chiasmal lesions, 11 cases of open-angle glaucoma, and 8 patients with lesions of the retina. METHODS: The stereoacuity and visual field in each case in group 1 (before and after surgery) and group 2 were assessed, and the results were compared. MAIN OUTCOME MEASURES: Stereoacuity was assessed by the Titmus stereo test (normal value for circle, 6/9; 80 seconds of arc) and by Lang-stereotest (normal value for circle, 3/3; 350 seconds of arc). Visual field was evaluated by Goldmann and Humphrey perimetry (conventional perimetry), the starlight test (binocular visual field test), and scanning laser ophthalmoscopic microperimetry (microperimetry). RESULTS: Before surgery, 11 of 13 cases (85%) in group 1 failed stereo tests, and after surgery, 5 of 13 cases (38%) in group 1 failed stereo tests. Before surgery, four patients who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis; after surgery, one patient who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis. However, starlight testing showed complete bitemporal hemianopsia only under binocular conditions, and microperimetry demonstrated a relative bitemporal hemianopsia at the fixating point. No patient failed in the Titmus circle test, but one patient in group 2 failed the Lang test (3%). The patients with chiasmal lesions significantly lost the ability of stereopsis compared with other diseases (group 1 [before or after surgery] vs. group 2, P < 0.001, Fisher's exact test). Conventional perimetry was unable to measure scotomas within 3 degrees of the fixation point, which is the key area for acute foveal stereopsis, because of an attached observational mirror. CONCLUSIONS: The difficulty with stereopsis in patients with lesions of the optic chiasm is most likely caused by the compression of the decussating optic nerve fibers resulting in the loss of an overlapping visual field at the fixation point. Stereo tests were demonstrated to be simple and effective adjunctive tests for suspected chiasmal compression.

Adolescent↗
PubMed2002

Rice SPK, a calmodulin-like domain protein kinase, is required for storage product accumulation during seed development: phosphorylation of sucrose synthase is a possible factor.

Suc, an end product of photosynthesis, is metabolized by Suc synthase in sink organs as an initial step in the biosynthesis of storage products. Suc synthase activity is known to be regulated by reversible phosphorylation, but the details of this process are unclear at present. Rice SPK, a calcium-dependent protein kinase, is expressed uniquely in the endosperm of immature seed, and its involvement in the biosynthetic pathways of storage products was suggested. Antisense SPK transformants lacked the ability to accumulate storage products such as starch, but produced watery seed with a large amount of Suc instead, as the result of an inhibition of Suc degradation. Analysis of in vitro phosphorylation indicated that SPK phosphorylated specifically a Ser residue in Suc synthase that has been shown to be important for its activity in the degradation of Suc. This finding suggests that SPK is involved in the activation of Suc synthase. It appears that SPK is a Suc synthase kinase that may be important for supplying substrates for the biosynthesis of storage products.

Amino Acid Sequence↗