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Biomedical subjects

H Terasaki

Publications and source records attributed to H Terasaki.

At least 19 recordsLinked to original sources
PubMed2001

FZD4S, a splicing variant of frizzled-4, encodes a soluble-type positive regulator of the WNT signaling pathway.

Frizzled-1 (FZD1)-FZD10 are seven-transmembrane-type WNT receptors, and SFRP1-SFRP5 are soluble-type WNT antagonists. These molecules are encoded by mutually distinct genes. We have previously isolated and characterized the 7.7-kb FZD4 mRNA, encoding a seven-transmembrane receptor with the extracellular cysteine-rich domain (CRD). Here, we have cloned and characterized FZD4S, a splicing variant of the FZD4 gene. FZD4S, corresponding to the 10.0-kb FZD4 mRNA, consisted of exon 1, intron 1, and exon 2 of the FZD4 gene. FZD4S encoded a soluble-type polypeptide with the N-terminal part of CRD, and was expressed in human fetal kidney. Injection of synthetic FZD4S mRNA into the ventral marginal zone of Xenopus embryos at the 4-cell stage did not induce axis duplication by itself, but augmented the axis duplication potential of coinjected Xwnt-8 mRNA. These results indicate that the FZD4 gene gives rise to soluble-type FZD4S as well as seven-transmembrane-type FZD4 due to alternative splicing, and strongly suggest that FZD4S plays a role as a positive regulator of the WNT signaling pathway.

Alternative Splicing↗
PubMed2001

Keratinocyte growth factor prevents ischemia-induced delayed neuronal death in the hippocampal CA1 field of the gerbil brain.

Fibroblast growth factors (FGFs) are polypeptides with various biological activities in vivo and in vitro, and their receptors are expressed in the widespread and specific neuronal populations of the brain. In this study, we asked whether keratinocyte growth factor (KGF), one of the FGF superfamily, would express in the brain, and have neuroprotective against ischemic brain injury. In situ hybridization analysis revealed that intense silver grains for KGF mRNA are observed in the neuronal cells of the cerebral cortex, hippocampus and amygdala in gerbil brain. Continuous cerebroventricular infusion of KGF (20 microg) for a 7 day period to gerbils starting 2 days before temporary right carotid artery occlusion (20 min) resulted in a higher survival rate than seen in vehicle-treated ischemic animals. Subsequent histological examinations showed that KGF effectively prevented delayed neuronal death of the hippocampal CA1 region. In situ detection of DNA fragmentation (TUNEL staining) revealed that ischemic animals infused with KGF contained fewer TUNEL-positive neurons in the hippocampal CA1 field than those infused with vehicle alone at the forth and seventh day after ischemia. KGF-treated brain showed over-expression of KGF mRNA in the neuronal cells of the cerebral cortex, hippocampus only in the right hemisphere, which was the side of carotid artery occlusion, 8-10 h after ischemia. These findings suggest that KGF has a protective effect against ischemic hippocampal neuronal damage in vivo, which may provide a new therapeutic strategy in the survival and reconstruction of neurons in response to cerebral injury.

Animals↗
PubMed2001

Progressive change of optical coherence tomography scans in retinal degeneration slow mice.

OBJECTIVE: To study whether optical coherence tomography (OCT) scans correlate retinal histologic findings with the progression of retinal degeneration in retinal degeneration slow (rds) mice. METHODS: Sensory retinal thickness (SRT) and outer retinal thickness (ORT), representing photoreceptor cell layer, in temporal retina at a distance 1 to 2 disc diameters from the optic disc were measured using scan profile in OCT from 6 healthy mice (16 weeks old) and 2-week-old (n = 6), 6-week-old (n = 4), and 60-week-old (n = 2) rds mice. Histologic sections were obtained from Epon-embedded retinas from the corresponding location. RESULTS: Cross-sectional OCT images correlated to the corresponding histologic sections in each mouse. Both SRT and ORT of 2-week-old rds mice (150 +/- 4 microm and 28 +/- 4 microm, respectively) lacking photoreceptor outer segments were already shorter than those of healthy mice (174 +/- 5 microm and 37 +/- 6 microm, respectively) (P<.001). In 6-week-old mice, microscopic findings revealed a decreased number of nuclei in the outer nuclear layer, and SRT and ORT (136 +/- 2 microm and 20 +/- 1 microm, respectively) were shorter than those of 2-week-old rds mice (P<.001). The SRT of 60-week-old rds mice without a photoreceptor layer was remarkably reduced (120 +/- 7 microm), and no ORT could be measured. CONCLUSION: Our findings suggest a possible relationship between SRT and ORT, as measured by OCT, and histologic change in retinal degenerative diseases. CLINICAL RELEVANCE: The quantitative analysis obtained by OCT scans may have potential to detect progressive change in degenerative retina and may be used in studying human retinal degeneration.

Animals↗
PubMed2001

Vitreoretinal traction maculopathy caused by retinal diseases.

PURPOSE: To study the morphological findings of vitreoretinal traction maculopathy caused by retinal vascular diseases and their changes after vitrectomy. METHODS: Optical coherence tomographic images of 13 eyes of 12 cases were evaluated before and after vitrectomy. RESULTS: The tractional force appeared to be mainly tangential with a possible anterior vector in 11 eyes, and mainly in the anterior direction in 2 eyes. After surgery, the increased foveal thickness decreased markedly in all eyes, and visual acuity improved in 8 eyes. CONCLUSION: Preoperative optical coherence tomographic examination can reveal the fine structure of vitreoretinal separations and adherences caused by retinal vascular diseases. These observations permitted better surgical planning and results.

Adult↗
PubMed2001

Axial length and refractive error in X-linked retinoschisis.

PURPOSE: To examine the relationship between axial length and refractive error in patients with X-linked retinoschisis. DESIGN: To determine whether the hypermetropia frequently found in patients with X-linked retinoschisis is axial hypermetropia. METHODS: The axial length and refractive error were measured in 29 right eyes of 29 patients. The patients were divided into two groups: a juvenile group with ages <13 years (12 eyes) and an adult group with ages > or =13 years (17 eyes). The axial length of the right eye of 30 adult men without eye diseases whose refractive error ranged from +/- 1.0 diopter served as controls. RESULTS: In the adult patient group, the refractive error was significantly more hypermetropic and the axial length was significantly shorter than was the normal adult group (P <.001). CONCLUSION: These results strongly suggest that the hypermetropia in patients with X-linked retinoschisis is axial hypermetropia.

Adolescent↗
PubMed2001

Electroretinogram in the diagnosis of endophthalmitis after intraocular lens implantation.

PURPOSE: To determine whether single flash electroretinograms can assist in the diagnosis of eyes with endophthalmitis after intraocular lens implantation. METHODS: Sixteen eyes with postoperative endophthalmitis treated with vitrectomy or intraocular lens removal were studied. The preoperative electroretinogram findings, duration until the onset of endophthalmitis, culture results, and postoperative visual acuity were analyzed. RESULTS: Four eyes with a b-wave/a-wave (b/a) ratio less than 1.0 and early onset of endophthalmitis within 1 week had worse postoperative visual acuity (no light perception to 20/200) than the other 12 eyes (20/100 to 20/15) (P =.0035). Pseudomonas aeruginosa and Enterococcus faecalis were cultured in these 4 eyes. CONCLUSION: The combination of a b/a ratio less than 1.0 and early onset of endophthalmitis may indicate poor prognosis in a patient with postoperative endophthalmitis.

Aged↗
PubMed2001

Unilateral cone dysfunction with bull's eye maculopathy.

OBJECTIVE: To report a Japanese subject who presented with an acute-onset, unilateral cone dysfunction with bull's eye maculopathy and to describe the functional changes determined by psychophysical and electrophysiologic tests. DESIGN: A single observational case report. METHODS: In addition to a complete ophthalmic examination, the subject underwent some electrophysiologic and psychophysical tests. MAIN OUTCOME MEASURES: Kinetic visual field test, cone and rod perimetry (two-color perimetry), full-field electroretinograms (ERGs), focal macular ERGs, and multifocal ERGs. RESULTS: The full-field ERGs and two-color perimetry showed a predominant loss of cone function in the right eye, whereas the left eye was normal. Cone perimetry and multifocal ERGs revealed that there were small regions functioning normally and other retinal areas that were severely altered in the right eye. CONCLUSIONS: The topographical function analysis suggested that the disorder affected the retina unevenly. The cause of this rare case of unilateral cone dysfunction with bull's eye maculopathy still remains unknown.

Acute Disease↗
PubMed2001

Long-term mild hypothermia with extracorporeal lung and heart assist improves survival from prolonged cardiac arrest in dogs.

BACKGROUND AND PURPOSE: although normothermic extracorporeal lung and heart assist (ECLHA) improves cardiac outcomes, patients can not benefit from hypothermia-mediated brain protection. The present study evaluated the effects of long-term ECLHA with mild to moderate hypothermia (33 degrees C) in a canine model of prolonged cardiac arrest. METHODS: 15 dogs were assigned to either the hypothermic (seven dogs, 33 degrees C) or normothermic group (eight dogs, 37.5 degrees C). All dogs were induced to normothermic ventricular fibrillation (VF) for 15 min, followed by 24 h of ECLHA and 72 h of intensive care. The hypothermia group maintained core (pulmonary artery) temperature at 33 degrees C for 20 h starting from resuscitation, then were rewarmed by 28 h. Outcome evaluations included: (1) mortality; (2) catecholamine dose; (3) time to extubation; (4) necrotic myocardial mass (g); and (5) neurological deficits score (NDS). RESULTS: in the normothermic group five dogs died of cardiogenic shock and one dog succumbed to poor oxygenation. The two surviving dogs remained comatose (NDS 60.5 +/- 4.9%) with necrotic myocardial mass of 14.5 +/- 3.5 g. In the hypothermic group, one dog died from pulmonary dysfunction, the other six dogs survived. The surviving dogs showed brain damage (29.8 +/- 2.5%), but there was evidence of some brain-protective effect. The mass of necrotic myocardium was 4.2 +/- 1.3 g in the hypothermic group or 3.4 times smaller than in the normothermic group. The survival rate was significantly higher in the hypothermic than in the normothermic group (P < 0.05). The catecholamine requirement was also lower in the hypothermic than in the normothermic dogs (P < 0.05). CONCLUSIONS: Long-term mild to moderate hypothermia with ECLHA induced immediately after cardiac arrest improved survival as well as cerebral and cardiac outcomes.

Analysis of Variance↗
PubMed2001

Experimental evaluation of the V-point heparin-bonding system applied to a dense-membrane artificial lung during 24-hour extracorporeal circulation in beagles.

Heparin was covalently bonded to a hollow-fiber dense-membrane artificial lung and circuit using a silane coupling agent and polyethyleneimine as a spacer. This study investigated whether the novel artificial lung could sustain prolonged extracorporeal lung assist (ECLA) by venoarterial bypass in beagles using minimal anticoagulants. We maintained ECLA for 24 h in 3 groups of minimal systemic heparinization, heparinization with the new anticoagulant nafamostat mesilate, and without any systemic anticoagulant. The results were assessed from the functional performance of the artificial lung and by macroscopic and microscopic examination after the experiments. Artificial lung function, hemodynamics, hemogram, and platelet aggregation activity were well maintained in all groups. There was no plasma leakage from the artificial lung. Although several clots were observed in stagnant areas of the artificial lungs and circuits, there was no clot formation inside the artificial lung in any group. This highly biocompatible, heparin-bonded dense-membrane artificial lung performed well and safely during prolonged ECLA with blood clotting times less than 120 s.

Animals↗
PubMed2001

Primary synovial sarcoma of the lung: a case report confirmed by molecular detection of SYT-SSX fusion gene transcripts.

We report a rare case of primary synovial sarcoma of the lung. The patient was a 49-year-old woman who presented with a well-defined oval-shaped mass in the left upper lobe on a chest radiograph. A malignant pulmonary tumor was suspected and consequently a left upper lobectomy was performed. Grossly, the tumor measured 5 x 4 cm, was whitish-yellow in color and soft in consistency. Histologically, the tumor showed a dense proliferation of short spindle cells, partly arranged in interlacing fascicles. In some areas a hemangiopericytoma-like pattern, stromal myxoid change and necrosis of various sizes were noted. Numerous mitotic figures were also seen. Immunohistochemically, the tumor cells were positive for epithelial markers such as cytokeratin and epithelial membrane antigen. As these features suggested a monophasic fibrous type of synovial sarcoma, we examined for the presence of SYT-SSXfusion gene transcripts using RNA samples from the frozen tumor tissue. A reverse transcription polymerase chain reaction amplified a single 583-base pair fragment characteristic of synovial sarcoma. As no other tumorous lesions were found during a follow-up period of 1 year, primary synovial sarcoma of the lung was our final diagnosis. This tumor should be considered in the differential diagnosis of round to short spindle cell tumors arising in the lung.

Female↗
PubMed2001

Histopathologic findings of cornea verticillata in a woman heterozygous for Fabry's disease.

PURPOSE: To report the histopathologic findings of the cornea verticillata observed in a woman who was heterozygous for Fabry's disease. METHOD: A 67-year-old woman was found to have a whorl-like corneal opacity on her visit to the Department of Ophthalmology. Aichi Saiseikai Hospital. Her visit was because of a sudden loss of vision in her right eye owing to a central retinal artery occlusion in association with an ophthalmic artery occlusion. The patient died suddenly of an acute heart failure; with family consent, an autopsy was performed and the right eye was removed for histopathologic examination by light and electron microscopy. RESULTS: Low levels of alpha-galactosidase in the leukocytes together with the corneal finding led to the diagnosis of heterozygous Fabry's disease. Light microscopy revealed a 0.3- to 0.5-microm thick layer between the epithelial and Bowman's layers. Oil red O positive deposits were accumulated in the subepithelial layer, and the density varied in different regions. Electron microscopy showed that subepithelial layer differed in thickness, and the basal lamina reduplicated regionally. We were not able to determine the structure that correlated with the "ridge" in the central part of the cornea. CONCLUSION: The oil red O positive deposits and their variation in density in the subepithelial area of the cornea may have caused the characteristic whorl-like corneal opacity in this woman who was heterozygous for Fabry's disease.

Aged↗
PubMed2001

Focal macular ERGs in eyes after removal of macular ILM during macular hole surgery.

PURPOSE: The removal of the internal limiting membrane (ILM) for traction maculopathy has recently been advocated. However, it is generally believed that the ILM plays an important role in retinal function, because it is the basal lamina of the Müller cells that are involved in the generation of the electroretinogram (ERG) b-wave. To date, there has been no objective assessment of retinal function on removing the ILM. In this study, the changes of each component of the focal macular electroretinograms (FMERGs) were investigated in eyes before and after the ILM was removed in the macular area during surgery for idiopathic macular holes (IMHs). METHODS: FMERGs were elicited by a 15 degrees stimulus centered on the fovea and monitored by an infrared fundus camera. FMERGs were recorded from 49 eyes of 48 patients with IMHs before and 6 weeks after anatomically successful macular hole surgery. Whether an eye had or did not have the ILM removed was randomly determined. The ILM was removed in 30 eyes (ILM-off group) and was not removed in 19 eyes (ILM-on group). Six months after surgery, the same examination was performed in 27 eyes of the ILM-off group and in 15 eyes of the ILM-on group. The amplitudes and implicit times of the a- and b-waves and the mean amplitudes and implicit times of the first three oscillatory potentials (OP1 to OP3) were compared before and after surgery within and between the groups. RESULTS: Visual acuity increased significantly after surgery in both groups. In the ILM-on group, the amplitude of the a- and b-waves and the OPs increased significantly 6 months after surgery (P: = 0.0093, P: = 0.0019, P: = 0.0024, respectively, paired t-test). In the ILM-off group, the a-wave amplitude and mean OP amplitudes were significantly larger 6 months after surgery (P: = 0.0077, P: = 0.0030, respectively, paired t-test). The b-wave amplitude, however, did not change significantly. The percentage increase in the b-wave amplitude 6 months after surgery was significantly higher in the ILM-on group (44.0%) than in the ILM-off group (15.0%; P: = 0.037, t-test). CONCLUSIONS: The removal of the ILM had no adverse effect on visual acuity. However, the selective delay of recovery of the FMERG b-wave 6 months after surgery suggests an alteration of retinal physiology in the macular region.

Aged↗
PubMed2001

[Anesthetic management of a patient with pheochromocytoma and cerebral ischemic attacks].

A 15-year-old girl with history of two cerebral ischemic attacks possibly caused by cerebral vascular spasm was diagnosed as having a pheochromocytoma, and was scheduled for laparoscopic removal of the adrenal tumor. Epidural catheterization was performed at Th 12/L 1. General anesthesia was induced with thiamylal and vecuronium, and maintained with nitrous oxide-oxygen-isoflurane and continuous epidural infusion of 1.5% lidocaine. Phentolamine and thiamylal were continuously administrated into the vein. While operating on the tumor, abnormal hypertension did not occur. Just after removal of the tumor, the systolic blood pressure fell to 50-70 mmHg. The hypotension continued for about 75 min, despite administration of dopamine, norepinephrine and epinephrine. After the emergence from anesthesia, the blood pressure recovered to normal level. No neurocerebral abnormality was found. In patients like this one, we have to prevent cerebral vascular spasm and cerebral infarction caused by excessive secretion of catecholamines.

Adolescent↗
PubMed2001

Multifocal ERG findings in complete type congenital stationary night blindness.

PURPOSE: To study the multifocal electroretinogram (mfERG) in patients with the complete type of congenital stationary night blindness (cCSNB), which is thought to be due to a defect in neurotransmission from the photoreceptors to the ON-bipolar cells. METHODS: mfERGs were recorded with the VERIS recording system from four patients with cCSNB, none of whom had nystagmus. The stimulus array consisted of 61 hexagons, and the total recording time was approximately 4 minutes. The amplitudes and implicit times of the first- and second-order kernels of the local responses were compared with those from 20 myopic controls. Waveforms of the summed response from all locations were also compared between the two groups. RESULTS: The first-order kernels of the mfERGs of cCSNB patients had normal amplitudes but delayed implicit times for nearly the whole field tested. The second-order kernel was severely attenuated in amplitude in cCSNB patients. The ratios of the second- to first-order kernel amplitudes were significantly reduced in cCSNB and clearly separated the cCSNB group from the control group without any overlap of the values. CONCLUSIONS: The second-order kernel, which is involved in adaptative mechanism of the retina to repeated flashes, is selectively reduced in cCSNB. The delay of the implicit times of the first-order kernel in patients with cCSNB may be related to the severe amplitude reduction of the second-order kernel.

Adolescent↗
PubMed2001

Novel CACNA1F mutations in Japanese patients with incomplete congenital stationary night blindness.

PURPOSE: Although it was reported that congenital stationary night blindness (CSNB) could be divided into complete and incomplete CSNB clinically in 1986, it was not until 1998 that the two types were found to be distinct clinical diseases by molecular genetic analysis. The purpose of this article is to report mutations in the retina-specific calcium channel alpha1-subunit gene (CACNA1F) in Japanese patients with incomplete CSNB and to describe the clinical features of these patients. METHODS: Seven patients from five separate Japanese families with incomplete CSNB were examined. Genomic DNA was extracted from leukocytes of the peripheral blood, and all 48 exons of the CACNA1F were amplified by polymerase chain reaction and directly sequenced. A complete ophthalmic examination was performed, including best corrected visual acuity, slit lamp and fundus examinations, fundus photography, and electroretinography. RESULTS: A mutation in the CACNA1F was identified in all the patients. The identified mutations were a missense mutation (Gly609Asp); a nonsense mutation (Arg913stop); a splice donor site mutation of G to C at nucleotide 2571+1; a G insertion at nucleotide 709, resulting in a frame shift with a predicted stop codon at codon 247; and a 4-bp deletion at nucleotides 271 to 274, with a replacement by an abnormal 34-bp sequence. Clinically, each patient had essentially normal fundi, mildly reduced corrected visual acuity, and slight myopia or hyperopia with astigmatism. Electrophysiologically, the mixed rod-cone ERG showed a negative configuration with recordable oscillatory potentials. The rod ERG was recordable but subnormal, and the cone and 30-Hz flicker ERGs were markedly depressed. CONCLUSIONS: Five novel mutations were identified in the CACNA1F in five Japanese families with incomplete CSNB, leading to the conclusion that in most Japanese patients, incomplete CSNB is caused by a CACNA1F mutation.

Adolescent↗
PubMed2001

Rescue of retinal function by macular translocation surgery in age-related macular degeneration and other diseases with subfoveal choroidal neovascularization.

Age-related macular degeneration (AMD) is the leading cause of legal blindness among the elderly. In AMD and some other macular diseases, subfoveal choroidal neovascularization (CNV) damages the underlying retinal pigment epithelium (RPE), and because retinal function is dependent on a healthy RPE, vision is markedly reduced by a subfoveal CNV. To treat such CNVs, macular translocation surgery has been performed to move the sensory retina from the damaged RPE to healthier RPE. At present, this surgery is the only possible treatment to improve the visual acuity of patients with subfoveal CNV. Macular translocation surgery involves the detachment of the entire retina from the RPE by a subretinal infusion of fluid and creating a 360 degrees circumferential retinotomy followed by the rotation of the retina. Severe postoperative complications such as recurrent retinal detachment have been reported in about 30% of the cases after macular translocation. To determine the efficacy of this surgery, it is necessary to demonstrate an improvement in macular and overall retinal function objectively as well as subjectively. To this end, we have assessed the changes in visual function by measuring the visual acuity subjectively, and the macular function objectively by focal macular ERGs (FERGs). We shall show that there is an improvement in the FERGs in most patients after retinal translocation surgery but the full-field ERGs were reduced by about 30%. Thus, macular translocation surgery with 360-degree retinotomy may be feasible for macular function, although some degree of peripheral retinal function is lost.

Aging↗