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Biomedical subjects

H Terasaki

Publications and source records attributed to H Terasaki.

At least 19 recordsLinked to original sources
PubMed2006

Seasonal variations of acute massive submacular haemorrhage associated with age-related macular degeneration.

AIMS: To determine whether there is a seasonal variation in the onset of acute, massive submacular haemorrhage associated with age-related macular degeneration. METHODS: Sixty eyes of 59 patients diagnosed between April 1998 and March 2005, were studied retrospectively. For each patient, the month and season of onset of the submacular haemorrhage and the mean monthly ambient temperature in Nagoya were analysed. Any history of systemic hypertension was also recorded, and the seasonal variations were also investigated in hypertensive and non-hypertensive groups. RESULTS: The number of cases peaked in winter with a trough in summer, and this seasonal variation was significant (Roger's R = 12.03, p<0.01). The monthly incidence was inversely correlated with the temperature (Spearman's rank correlation coefficient r = 0.89, p<0.01). The seasonal variations were significant in the hypertensive group but not in the non-hypertensive group. CONCLUSION: The considerable seasonal variations suggests that the mechanism for the haemorrhage is strongly correlated with the systemic blood pressure.

Acute Disease↗
PubMed2005

Selective and efficient culturing of retinal pigment epithelial cells using a feeder layer.

BACKGROUND: The techniques to isolate and purify retinal pigment epithelial (RPE) cells from small piece of autologous tissues are extremely difficult, and it is important to develop an efficient cell culture technique for RPE cells. The purpose of this study was to investigate the effect of 3T3-J2 cells and conditioned medium from 3T3-J2 cells on the proliferation of cultured RPE cells. METHODS: RPE cells from pigmented rabbits and a human RPE-derived cell line, ARPE-19, were used. First, the effects of co-culturing RPE cells with 3T3-J2 cells on the growth of the cells were analyzed. Second, the effects of the conditioned medium from 3T3-J2 cells on the proliferation of both types of cells were investigated. And third, the effects of the conditioned medium on RPE cell culture from a surgically removed choroidal neovascular (CNV) membrane were investigated. RESULTS: The 3T3-J2 cells increased the proliferation of both rabbit RPE cells and ARPE-19 cells. The number of rabbit RPE cells cultured in a mixture of the conditioned medium from 3T3-J2 cells was significantly higher than that in the reported optimal condition, and a similar tendency was observed for ARPE-19 cells. The results from enzyme-linked immunosorbent assay showed the presence of PDGF-AB, VEGF and IGF-I in the conditioned medium. The conditioned medium also promoted selective growth of human RPE cells from CNV. DISCUSSION: The results from this study present the conditions for efficient and selective culture of primary RPE cells.

3T3 Cells↗
PubMed2002

Polypoidal choroidal vasculopathy treated with macular translocation: clinical pathological correlation.

AIMS: To report the histopathology of two specimens of polypoidal choroidal vasculopathy (PCV) obtained from two eyes of Japanese patients. METHODS: Specimens were obtained under direct visualisation during macular translocation surgery with 360 degree retinotomy. The clinical findings were correlated with the light microscopic findings of the two specimens. RESULTS: One specimen from a 77 year old man was the central portion of the lesion that lay under the sensory retina on the retinal pigment epithelium (RPE). The specimen was made up mainly of fibrous tissue with small, thin walled vessels. Indocyanine green angiography after surgery revealed that active leaking polypoidal element remained under the RPE. Another specimen obtained from a 62 year old man was made up of a fibrovascular membrane situated within Bruch's membrane. The part of this specimen inferior to the foveal region included a collection of dilated, thin walled blood vessels without pericytes, surrounded by macrophages that stained positive for CD68. The dilated vessels appeared to be correlated with the orange coloured polyps observed by ophthalmoscopy, the polypoidal structure seen in indocyanine green angiograms, and the pyramidal elevation with intermediate reflectivity by optical coherence tomography. CONCLUSION: Polypoidal structures are located within Bruch's space. They are composed of clusters of dilated, thin walled blood vessels surrounded by macrophages and fibrin material. The positive immunohistochemical staining for vascular endothelial growth factor in the RPE and the vascular endothelial cells suggests that this fibrovascular complex is a subretinal choroidal neovascularisation.

Aged↗
PubMed2001

WNT2B2 mRNA, up-regulated in primary gastric cancer, is a positive regulator of the WNT- beta-catenin-TCF signaling pathway.

Genetic alterations of WNT signaling molecules lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway. We have previously cloned and characterized WNT2B/WNT13 gene on human chromosome 1p13, which is homologous to proto-oncogene WNT2 on human chromosome 7q31. WNT2B1 and WNT2B2 mRNAs, generated from the WNT2B gene due to alternative splicing of the alternative promoter type, encode almost identical polypeptides with divergence in the N-terminal region. WNT2B2 mRNA rather than WNT2B1 mRNA is preferentially expressed in NT2 cells with the potential of neuronal differentiation. Here, we describe our investigations of expression of WNT2B mRNAs in various types of human primary cancer. Matched tumor/normal expression array analysis revealed that WNT2B mRNAs were significantly up-regulated in 2 of 8 cases of primary gastric cancer. WNT2B2 mRNA rather than WNT2B1 mRNA was found to be preferentially up-regulated in a case of primary gastric cancer (signet ring cell carcinoma). Function of WNT2B1 mRNA and that of WNT2B2 mRNA were investigated by using Xenopus axis duplication assay. Injection of synthetic WNT2B1 mRNA into the ventral marginal zone of fertilized Xenopus eggs at the 4-cell stage did not induce axis duplication. In contrast, ventral injection of synthetic WNT2B2 mRNA induced axis duplication in 90% of embryos (complete axis duplication, 24%). These results strongly suggest that WNT2B2 up-regulation in some cases of gastric cancer might lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway.

Animals↗
PubMed2001

Detection of HER-2/neu (c-erb B-2) DNA amplification in primary breast carcinoma. Interobserver reproducibility and correlation with immunohistochemical HER-2 overexpression.

BACKGROUND: Fluorescent in situ hybridization (FISH) has been shown to be one of the most reliable methods with which to estimate the status of the HER-2/neu (or c-erb B-2) oncogene at the DNA level. METHODS: To study interobserver reproducibility and to determine more clinically correlated criteria for HER-2/neu alterations, two observers independently estimated HER-2/neu DNA status. The correlation between the consensus HER-2/neu DNA status by FISH and HER-2/neu protein status detected by immunohistochemistry (IHC) using a polyclonal antibody was studied in 216 surgically resected breast carcinomas and 34 noncancerous tissues. RESULTS: According to the HER-2/CEP17 ratio and mean HER-2 copies per nucleus, agreement level of HER-2/neu amplification was shown to be nearly perfect between two observers (kappa statistic (kappa) = 0.94 and kappa = 0.84). Finally, 40 tumors (19%) were judged to have HER-2/neu DNA amplification, with 6 having low-level amplification (> or = 2 but < 3 folds) and 34 having high-level amplification (> or = 3 folds). One hundred seventy-six other tumors, including 3 tumors that only 1 of the observers determined to be low-level amplifiers, and 34 noncancerous tissues had no detected amplification. The DNA amplification status was concordant between invasive and intraductal components in 14 carcinomas. HER-2/neu protein overexpression of moderate (2+) or high (3+) intensity based on IHC was detected in 51 carcinomas (24%), and was 2+ in 20 carcinomas and 3+ in 31 carcinomas. The HER-2/CEP17 ratio of > or = 2 was concordant with IHC findings of 2+/3+ in 91% of carcinomas (195 of 215 carcinomas), with a sensitivity of 70% (35 of 50 carcinomas) and a specificity of 97% (160 of 165 carcinomas). High-level amplification was detected in 29 of 31 IHC 3+ cases (94%), but in only 5 of 20 IHC 2+ cases (25%) and 0 in 165 IHC 0/1+ cases. All 34 cases with high-level amplification showed an IHC score of 3+ (29 cases) or an IHC score of 2+ (5 cases), but only 1 case was found to have an IHC score of 3+ and the remainder were IHC 0/1+ in 6 low-amplification cases. The concordance rate of the high-level amplification with an IHC score of 3+ was 97% (208 of 215 cases), with a sensitivity of 94% (29 of 31 cases) and a specificity of 97% (179 of 184 cases). CONCLUSIONS: The results of the current study indicated that high-level HER-2/neu amplification and an IHC score of 3+ nearly optimally identified breast carcinomas with clinically and biologically significant HER-2/neu activation. Conversely, it was confirmed that careful interpretation of test results is required in the case of low-level amplification and/or an IHC score of 2+.

Breast Neoplasms↗
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

Adenocarcinoma of the nonpigmented ciliary epithelium: report of two cases with immunohistochemical findings.

BACKGROUND: Acquired neoplasms arising from the nonpigmented ciliary epithelium (NPCE) are much less common than uveal melanocytic proliferations. We report two cases of acquired neoplasms arising from the NPCE with immunohistochemical findings. METHODS: Case reports. RESULTS AND CONCLUSIONS: Patient 1 was a 39-year-old man who presented with a pigmented mass behind the iris and secondary exudative retinal detachment. The eye also developed neovascular glaucoma. Patient 2 was a 44-year-old woman with a ciliary body mass but without symptoms. Both of these tumors were classified histologically as low-grade adenocarcinomas of the NPCE from specimens successfully removed by iridocyclectomy. Immunohistochemical findings confirmed the origin of the tumor cells; however, some changes in the immunoreactivity to cytokeratin AE1 and epithelial membrane antigen were found.

Adenocarcinoma↗
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

Dantrolene ameliorates delayed cell death and concomitant DNA fragmentation in the rat hippocampal CA1 neurons subjected to mild ischemia.

The present study investigated whether dantrolene, which inhibits the Ca(2+) release from the intracellular Ca(2+) store sites, reduced nuclear DNA fragmentation and produced neuronal protection in a model of global forebrain ischemia. Male Wistar rats were subjected to four-vessel occlusion (4VO) for 5 min and then infused continuously with dantrolene or vehicle into the cerebral ventricle for 3 days. The intact rats did not undergo any intervention. The number of viable and DNA nick-end-labeled neurons in the hippocampal CA1 were evaluated 4 days after the ischemia. The number of viable neurons in the dantrolene-treated rats was significantly higher than that in the vehicle-treated rats and lower than that in the intact animals (P<0.01 and <0.05, respectively). The number of DNA nick-end-labeled nuclei was significantly lower in dantrolene-treated rats compared with the vehicle-treated animals (P<0.0001). No nick-end labeling was observed in the intact animals. A linear correlation was found between the number of viable cells and nick-end labeled nuclei in the CA1 (r=0.91, P<0.0001). These results suggest that the postischemic intraventricular dantrolene is effective in precluding neuronal death and concomitant nuclear DNA fragmentation following transient global ischemia.

Animals↗
PubMed2001

Delayed platelet dysfunction in prolonged induced canine hypothermia.

UNLABELLED: Mild to moderate hypothermia (33-32 degrees C) is recognized as beneficial for brain protection after brain trauma. However, there are few experimental reports on hemostatic changes during prolonged hypothermia. We compared hemostatic changes during 72 h of mild to moderate hypothermia with data in normothermic dogs. METHOD: Mongolian dogs in a hypothermic group (N=7, 33 degrees C core temperature) and normothermic group (N=6, 37.5 degrees C core temperature) were anesthetized and instrumented to control temperatures and record hemodynamic changes continuously. Hypothermia or normothermia was maintained for 72 h. Platelet count, platelet aggregation, and thromboelastograms (TEG) were measured in each group. RESULTS: Heart rate, blood pressure, pulmonary pressure and blood gas were not significantly different between the two groups. Platelet counts, compared to baseline values, were significantly decreased in both groups (P<0.01). Platelet aggregation was significantly decreased in the hypothermic group after 24 h (P<0.04). CONCLUSION: Long-term hypothermia induced platelet dysfunction, leading to decreased platelet aggregation and prolonged coagulation time (R and K times of TEG).

Animals↗
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↗