26
|
Mori F, Kawai M, Sato E, Igarishi S, Hikichi T, Yoshida A. Branch retinal vein occlusion in a Japanese patient with neurofibromatosis 1. Jpn J Ophthalmol 2001; 45:634-5. [PMID: 11754907 DOI: 10.1016/s0021-5155(01)00421-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND To report an Asian patient with branch retinal vein occlusion secondary to neurofibromatosis 1. CASE A 64-year-old woman presented with a loss of vision in her right eye of 9-month duration. A diagnosis of neurofibromatosis 1 was made. A general medical examination showed no abnormalities except the signs of neurofibromatosis 1. OBSERVATIONS Fundus examination of the right eye revealed irregularities of the venous caliber, partial sheathing of the corresponding vein and macular edema. Multiple dilated and tortuous collateral channels and an arteriovenous communication bridged the perfused and nonperfused retina. Fundus examination of the left eye showed a tortuous vein in the temporal region of the fovea. Fluorescein angiography of the right eye confirmed delayed filling in a superotemporal artery and in the corresponding vein. The temporal region of the fovea had large areas of capillary loss. The collaterals were tortuous and mimicked a neovascularization. Fluorescein angiography of the left eye confirmed that the vein in the temporal part of the fovea was tortuous and not leaking. A diagnosis of branch retinal vein occlusion of the superotemporal vein was made. CONCLUSIONS Neurofibromatosis 1 should be considered in the differential diagnosis of retinal vascular occlusive disease without other risk factors.
Collapse
|
27
|
Kinouchi R, Hirokawa H, Miyokawa N, Nomiyama T, Hikichi T, Yoshida A. [Immunohistochemical study of idiopathic and secondary epiretinal membrane]. NIPPON GANKA GAKKAI ZASSHI 2001; 105:673-81. [PMID: 11692613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
PURPOSE We investigated the immunohistochemical features of surgically resected idiopathic epiretinal membranes(ERMs) and secondary ERMs with regard to posterior vitreous detachment(PVD). METHODS Six specimens of idiopathic epiretinal membranes(3 eyes with complete PVD, 2 eyes with partial PVD, and one eye with no PVD) and 3 specimens of secondary ERMs(all eyes with complete PVD) were immunohistochemically studied. We used type I, II, III, IV collagen and fibronectin to study extracellular components, and glial fibrillary acidic protein(GFAP), S 100 protein, vimentin, and so forth to study cellular components. RESULTS All the specimens of idiopathic ERMs had the major components of the lamellar stained by type II collagen antibody, and one out of 3 specimens of secondary ERMs had a minor component stained by type II collagen antibody. Compared with idiopathic ERMs with complete PVD, 2 out of 3 specimens of idiopathic ERMs with partial PVD or no PVD contained rather thick collagen lamellar. CONCLUSION There was difference between specimens of idiopathic ERMs and specimens of secondary ERMs in staining by type II collagen antibody, supposed by vitreous, in this study. Idiopathic ERM with attached posterior vitreous membrane may cause growth of collagen.
Collapse
|
28
|
Hikichi T, Mori F, Takamiya A, Sasaki M, Horikawa Y, Takeda M, Yoshida A. Inhibitory effect of losartan on laser-induced choroidal neovascularization in rats. Am J Ophthalmol 2001; 132:587-9. [PMID: 11589891 DOI: 10.1016/s0002-9394(01)01139-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE To investigate the inhibitory effects of losartan, an angiotensin receptor antagonist, on angiogenesis in a rat model of laser-induced choroidal neovascularization. METHODS Experimental study. Fifteen Brown-Norway male rats received losartan (approximately 5 mg/kg/d) in drinking water, and 15 Brown-Norway male rats received unsupplemented drinking water 1 week before photocoagulation, and it was continued to the end of the study. Two weeks after intense laser photocoagulation, choroidal neovascularization was evaluated by fluorescein angiography and histopathologic evaluation. RESULTS The incidence of choroidal neovascularization formation was 99.5 +/-.2% (mean +/- standard deviation) in controls and 72.5 +/- 8.8% in losartan-treated rats (P <.01). Quantitative morphometric assessment revealed mean choroidal neovascularization lesion thickness of 54 and 44.8 microm, respectively, in controls and losartan-treated rats (P <.01). CONCLUSION Losartan seems to inhibit development of laser-induced choroidal neovascularization. Angiotensin receptor antagonists may be useful as prophylaxis against choroidal neovascularization associated with age-related macular degeneration.
Collapse
|
29
|
Hikichi T, Onodera A, Ishiko S, Fujio N, Mori F, Yoshida A. Stereo acuity in patients with unilateral macular hole and after unilateral macular hole surgery. Graefes Arch Clin Exp Ophthalmol 2001; 239:128-32. [PMID: 11372542 DOI: 10.1007/s004170100257] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To investigate stereo acuity levels in patients with unilateral idiopathic macular hole and after surgical intervention. METHODS In 31 consecutive patients with a unilateral macular hole and 46 consecutive patients who underwent successful unilateral macular hole surgery, complete ocular examinations, including orthoptic examinations and microperimetry using the scanning laser ophthalmoscope, were performed. RESULTS A significantly positive correlation was found between VA and stereo acuity (r = 0.87, P < 0.01). After successful surgery, stereo acuity also correlated with the presence or absence of absolute and/or relative scotoma, and was best in eyes without scotomata. Patients with unilateral idiopathic macular hole, suppression, and symptom duration of 24 months or longer had no stereoscopic vision. CONCLUSIONS The results indicated that in patients with unilateral idiopathic macular hole and after surgery, stereo acuity correlated with VA. Patients with unilateral macular hole should be operated upon as early as possible, resulting in better VA and better stereo acuity.
Collapse
|
30
|
Takahashi J, Mori F, Hikichi T, Yoshida A. Effect of acetazolamide on outward permeability of blood-retina barrier using differential vitreous flyorophotometry. Curr Eye Res 2001; 23:166-70. [PMID: 11803477 DOI: 10.1076/ceyr.23.3.166.5461] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE To measure fluorescein (F) and fluorescein monoglucuronide (FG) concentrations in the vitreous and evaluate the effect of acetazolamide (AZM) on the outward permeability of the blood-retina barrier (BRB) using differential vitreous fluorophotometry (DVF). METHODS DVF was performed 180 minutes after intravenous injection of AZM (5 mg/kg) and 50 mg of sodium fluorescein in six rabbits (AZM group). DVF also was performed in six rabbits injected intravenously with only 50 mg of sodium fluorescein (control group). The F/FG ratio was calculated based on the concentrations of F and FG obtained by DVF. DVF also was performed 180 minutes after 50 mg of intravenous injection of sodium fluorescein in five rabbits given probenecid (150 mg/kg) intraperitoneally (probenecid group). RESULTS The average F/FG ratio was 0.36 +/- 0.17 (range, 0.22-0.66) in the AZM group, which was significantly smaller than the control value of 0.74 +/- 0.22 (range, 0.50-1.60). The average F/FG ratio at 180 minutes after injection was 1.51 +/- 0.46 (range, 0.94-2.00) in the probenecid group, which was significant higher (p < 0.05) than that of the AZM or control group. CONCLUSIONS This study showed that the F/FG ratio might be a good indicator of the estimated outward permeability of the BRB using DVF and that AZM may accelerate the outward active transport function of the BRB.
Collapse
|
31
|
Hikichi T, Mori F, Nakajima S, Takamiya TA, Takeda M, Sasaki M, Horikawa Y, Yoshida A. Dynamic observation of selective accumulation of a photosensitizer and its photodynamic effects in rat experimental choroidal neovascularization. Retina 2001; 21:126-31. [PMID: 11321138 DOI: 10.1097/00006982-200104000-00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The authors investigated the selective accumulation of a photosensitizer, ATX-S10(Na), in experimental choroidal neovascularization (CNV) in rats using a highly sensitive colorchromatic charge coupled device (CCD) camera. METHODS To detect the development of experimental CNV in 30 rats, the animals were followed weekly with simultaneous fluorescein and indocyanine green angiography. After injecting ATX-S10(Na), the authors detected fluorescence from the photosensitizer using a highly sensitive color CCD camera. The camera was connected to a surgical microscope, under which rat fundi were observed through a coverglass in contact with the cornea. The retinas were excited with 405-435 nm light, and the light emitted from the photosensitizer passed through a 680-nm bandpass filter before being detected by the CCD camera. RESULTS Immediately after injection, fluorescence appeared in the retinal vessels and then the entire retina. Thirty minutes postinjection, the intensity of the fluorescence was still strong from the whole retina, and the CNV was not detected. One hour after injection, retinal fluorescence was weak but still observable; 1.5 hours postinjection, retinal fluorescence was undetectable but fluorescence was strong from the CNV. Under the optimum therapeutic conditions, CNV was effectively occluded. CONCLUSION ATX-S10(Na) selectively accumulates in the CNV in rats. The optimum therapeutic timing is approximately 1.5 hours postinjection of the dye in this CNV model.
Collapse
|
32
|
Mukai N, Harada M, Muroi K, Hikichi T, Yoshida A. New graphics models for PC based ocular surgery simulator. Stud Health Technol Inform 2001; 81:329-35. [PMID: 11317764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
High-end graphics workstations (GWS) have been used for surgical simulators utilizing Computer Graphics (CG) and Virtual Reality (VR) technologies. This is because the simulators need lots of computing power, mainly for collision detection among objects modeled as a set of polygons. In this paper, we propose to use mathematical functions to model objects for collision detection. However, for graphic display we continue to use polygonal representation. Using the new model, we have developed a PC based ocular surgery simulator, which creates realistic surgery image in real-time. The computation time was found to be much lower than that in the conventional method.
Collapse
|
33
|
Mori F, Konno S, Hikichi T, Yamaguchi Y, Ishiko S, Yoshida A. Factors affecting pulsatile ocular blood flow in normal subjects. Br J Ophthalmol 2001; 85:529-30. [PMID: 11316707 PMCID: PMC1723979 DOI: 10.1136/bjo.85.5.529] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND The factors that influence pulsatile ocular blood flow (POBF) were evaluated in normal subjects. METHODS POBF was measured in 80 normal subjects using Langham OBF computerised tonometry. The effect of age, systolic and diastolic blood pressure, refractive error, intraocular pressure, and axial length on POBF was evaluated using multiple regression analysis. RESULTS The mean (SD) POBF value was 593.3 (203.6) microl/min (range 290.7-1201.6). Of all the independent variables in the model, only the axial length was statistically significant (p = 0.008). The regression coefficient was negative, indicating that the axial length decreased with increasing POBF. CONCLUSIONS These data suggest that, in normal subjects, the POBF decreases as axial length increases. Choroidal blood flow may decrease as the axial length increases. The axial length may therefore be a major factor affecting POBF.
Collapse
|
34
|
Umitsuki G, Wachi M, Takada A, Hikichi T, Nagai K. Involvement of RNase G in in vivo mRNA metabolism in Escherichia coli. Genes Cells 2001; 6:403-10. [PMID: 11380618 DOI: 10.1046/j.1365-2443.2001.00430.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Escherichia coli rng gene (previously called cafA) encodes a novel RNase, named RNase G, which is involved in the 5' end-processing of 16S rRNA. In rng mutant cells, a precursor form of 16S rRNA, 16.3S rRNA, is accumulated. Here we report a role of RNase G in the in vivo mRNA metabolism. RESULTS We found that rng:cat mutant strains overproduced a protein of about 100 kDa. N-terminal amino acid sequencing of this protein showed that it was identical to the fermentative alcohol dehydrogenase, the product of the adhE gene located at 28 min on the E. coli genetic map. The level of adhE mRNA was significantly higher in the rng:cat mutant strain than that in its parental strain, while such differences were not seen in other genes we examined. A rifampicin-chase experiment revealed that the half-life of adhE mRNA was 2.5-fold longer in the rng:cat disruptant than in the wild-type. CONCLUSION These results indicate that, in addition to rRNA processing, RNase G is involved in in vivo mRNA degradation in E. coli.
Collapse
|
35
|
Mori F, Konno S, Hikichi T, Yamaguchi Y, Ishiko S, Yoshida A. Pulsatile ocular blood flow study: decreases in exudative age related macular degeneration. Br J Ophthalmol 2001; 85:531-3. [PMID: 11316708 PMCID: PMC1723978 DOI: 10.1136/bjo.85.5.531] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Pulsatile ocular blood flow (POBF) is a parameter for evaluating choroidal blood flow. POBF in the patients with non-exudative and exudative age related macular degeneration (AMD) was investigated. METHODS POBF, pulse amplitude (PA), systolic and diastolic blood pressures, intraocular pressure (IOP), refractive error, and axial length were compared among 10 patients with non-exudative AMD, 11 patients with exudative AMD, and 69 age matched controls. A Langham OBF computerised tonometer was used with the participants in the sitting position to measure POBF and PA. RESULTS No significant differences were found in age, systolic and diastolic blood pressures, IOP, or refractive error between patients with exudative and non-exudative AMD and the control subjects. In the patients with exudative AMD the POBF (median, 372.7 microl/min) and PA (median, 1.2 mm Hg) were significantly lower than in the patients with non-exudative AMD (median, 607.0 microl/min (p = 0.02) and 2.2 mm Hg (p = 0.04), respectively) and control subjects (median, 547.4 microl/min (p = 0.01) and 2.0 mm Hg (p = 0.01), respectively). CONCLUSIONS These data show that the POBF and PA in the patients with exudative AMD are lower than in the patients with non-exudative AMD and normal subjects. Decreased choroidal blood flow may have a role in the development of choroidal neovascularisation in AMD.
Collapse
|
36
|
Imamura H, Kobayashi H, Abe K, Hikichi T, Miyata M, Kasukawa R, Kusakabe T, Suzuki T. [An autopsy case of polyarteritis nodosa with myeloperoxydase-antineutrophil cytoplasmic antibody (P-ANCA) and clinical features of microscopic polyangiitis]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 2000; 89:2531-3. [PMID: 11214578 DOI: 10.2169/naika.89.2531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
37
|
Hikichi T, Yoshida A, Igarashi S, Mukai N, Harada M, Muroi K, Terada T. Vitreous surgery simulator. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2000; 118:1679-81. [PMID: 11115263 DOI: 10.1001/archopht.118.12.1679] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To reduce the surgical risks to patients and expose surgeons to surgical experience and complications, we have developed a practical system of vitreous surgery using virtual-reality technology. METHODS The system is composed of high-resolution color stereo binoculars, haptic devices, foot switches, and a high-speed graphics computer. To simulate vitreous surgery, we created several virtual patient eyes with retinal diseases such as preretinal membranes and subretinal neovascular tissue at the fovea. RESULTS The simulator provided the trainees with an operating environment similar to an actual one, and allowed them to learn to maneuver surgical instruments and remove proliferative tissue on the retina, under the retina, or both. This system allowed surgeons to avoid iatrogenic complications through visual signs such as retinal hemorrhage when the instrument contacted the retinal surface. CONCLUSIONS This simulator may not only be suitable for residents to learn ocular surgical techniques but may also allow veteran surgeons to develop new surgical methods and skills.
Collapse
|
38
|
Hikichi T, Akiyoshi J, Yamamoto Y, Tsutsumi T, Isogawa K, Nagayama H. Suppression of conditioned fear by administration of CRF receptor antagonist CP-154,526. PHARMACOPSYCHIATRY 2000; 33:189-93. [PMID: 11071021 DOI: 10.1055/s-2000-7587] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In order to examine the involvement of corticotropin-releasing hormone (CRF) receptor in the formation of anxiety, we investigated whether CRF receptor antagonist CP-154,526 suppressed conditioned fear stress. First, rats were individually subjected to 30 min of footshock. Twenty-four hours after footshock, the rats were again placed in the chamber and observed for 5 min without shock. CP-154,526 was administered 30 min before placing the rats in the chamber again. After that, CP-154,526 was once more administered 30 min before applying footshock. Administration of CP-154,526 30 min both before conditioned fear stress (placing the rats inside the cage but not applying footshock) and before actual footshock significantly reduced freezing behavior. These results show that CP-154,526 blocked both the acquisition and expression of conditioned fear, thus suggesting that the CRF receptor might be related to anxiety.
Collapse
|
39
|
Oshio H, Onodera H, Tamada O, Mizutani H, Hikichi T, Ito T. Cyanide-bridge Fe-Fe and Fe-Co molecular squares: structures and electrochemistry of. Chemistry 2000; 6:2523-30. [PMID: 10961396 DOI: 10.1002/1521-3765(20000717)6:14<2523::aid-chem2523>3.0.co;2-t] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cyanide-bridged iron-iron and iron--cobalt molecular squares of [Fe(II/4)(mu-CN)4(bpy)8[(PF6)4 x 4H2O (1), [Fe(II/2)Co(II/2)(mu-CN)4(bpy)8](PF6)4 x 3CHCl3 x 2CH3CN (2), and [Fe(II/2)Co(III/2)(mu-CN)4(bpy)8](PF6)6 x 2CHCl3 x 4CH3NO2 (3) (bpy =2,2'-bipyridine) were prepared. X-ray structure analyses for 1-3 were performed and their electrochemistry was studied. In 1-3, four metal ions are bridged by cyanide groups to form tetranuclear macrocycles ("molecular squares"). Each metal ion in the square is six-coordinate: four of the coordination sites are occupied by the nitrogen atoms of two of bpy ligands and the remaining cis coordination sites are occupied by cyanide-carbon or cyanide-nitrogen atoms. In 1, Fe-C (cyanide) (1.899(4)-1.927(4)A) and Fe-N(cyanide) (1.929(4)-1.950(4)A) distances are typical of low-spin Fe2+ ions. In 2, Fe-C(cyanide) and Co(2+)-N(cyanide) bond lengths are in the range 1.919(5)-1.963(5)A and 1.850(5)-2.017(5) A, respectively: in contrast, shorter bond lengths are observed for the metal to cyanide-carbon and cyanide-nitrogen (1.878(7)- 1.893(7) A) in 3. As a result, the molecular squares in 1. 2, and 3 have sides of 4.947(1)4.986(1) A, 5.001(1)-5.053(1) A, and 4.910(1)-4.918(1) A, respectively. Magnetic susceptibility measurements revealed that the Fe2+ and Co3- ions in 1 and 3 are diamagnetic, while the high-spin Co2+ ions in 2 are weakly coupled through the low-spin Fe2 ions. Cyclic voltammograms of the squares are presented, and the electrochemically generated mixed-valent species [Fe(II/2)Fe(III/2)(mu-CN)4(bpy)8]6+ was discussed in terms of the intervalence transfer band.
Collapse
|
40
|
Yanagiya N, Akiba J, Kado M, Hikichi T, Yoshida A. Effects of peroxynitrite on rabbit cornea. Graefes Arch Clin Exp Ophthalmol 2000; 238:584-8. [PMID: 10955660 DOI: 10.1007/s004170000126] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND Nitric oxide (NO) reacts rapidly with the superoxide anion to generate peroxynitrite, which has been found in the aqueous humor in eyes with uveitis. We evaluated the functional and anatomic effects of peroxynitrite on rabbit cornea. METHODS One eye of each rabbit received an anterior chamber injection of 3-morpholinosydonimine N-ethylcarbamide (SIN-1), which simultaneously generates both NO and the superoxide anion. The corneal thickness was measured using an ultrasonic pachymeter before and after the injection. The eyes were fixed and the corneal specimens were prepared for electron microscopy. RESULTS Anterior chamber injections of SIN-1 caused a significant increase in the corneal thickness (25.1+/-3.0 microm) 30 min after injection. Transmission electron microscopy showed swollen mitochondria and large vacuoles in the cytoplasm, and scanning electron microscopy revealed obscuring of the mosaic pattern by increased ruffling of endothelial cell surface and borders. CONCLUSION The results suggest that peroxynitrite generated in the aqueous humor may cause corneal endothelial cell damage, which leads to transient corneal edema.
Collapse
|
41
|
Hikichi T, Kado M, Yoshida A. Intravitreal injection of hyaluronidase cannot induce posterior vitreous detachment in the rabbit. Retina 2000; 20:195-8. [PMID: 10783954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
PURPOSE To investigate whether intravitreal injection of hyaluronidase can induce posterior vitreous detachment (PVD) in the rabbit. METHODS One eye each of 12 New Zealand white rabbits received intravitreal injection via the pars plana of 20 IU of hyaluronidase (0.1 mL reconstituted in sterile balanced salt solution [BSS]) into the midvitreous cavity. The fellow eye of each rabbit received a vitreous injection of 0.1 mL of BSS. At 3 and 6 months after intravitreal injection, four and eight rabbits were killed, respectively, and the eyes were enucleated. After fixation, scanning electron microscopy was performed to study the vitreoretinal interface. RESULTS At 3 and 6 months after injection, scanning electron microscopy showed that the retinal surfaces in eyes that received either hyaluronidase or BSS were covered with vitreous collagen fibers. No eyes, even those that received hyaluronidase over a period of 6 months, had the smooth retinal surface consistent with a bare internal limiting lamina that suggests the development of PVD. CONCLUSION Hyaluronidase cannot induce PVD in the rabbit over a 6-month period after vitreous injection.
Collapse
|
42
|
Isogawa K, Akiyoshi J, Hikichi T, Yamamoto Y, Tsutsumi T, Nagayama H. Effect of corticotropin releasing factor receptor 1 antagonist on extracellular norepinephrine, dopamine and serotonin in hippocampus and prefrontal cortex of rats in vivo. Neuropeptides 2000; 34:234-9. [PMID: 11021986 DOI: 10.1054/npep.2000.0806] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Corticotropin releasing factor (CRF) is a major mediator of adaptive responsiveness to stress. We measured changes in extracellular concentrations of catecholamine and indoleamines in freely moving rats in response to administration of CRF1 antagonist CP-154,526 by using in vivo microdialysis. Dialysis probes were placed stereotaxically in either the hippocampus or the prefrontal cortex. We examined the response in the hippocampus or the prefrontal cortex to 32.0 mg/kg i.p. administration of CP-154,526. CP-154,526 reduced the extracellular concentration of norepinephrine (NE) from 30 min to 180 min and 5-hydroxytryptamine (5-HT) from 30 min to 60 min after injection in the hippocampus. CP-154,526 did not remarkably change dopamine (DA). There were no significant differences between CP-154,526 and vehicle in NE, 5-HT and DA in the prefrontal cortex. The present results indicate that CRF1 receptor antagonist produced a decrease in dialysate concentration of NE and 5-HT, but not DA, in the hippocampus. These results suggest that the CRH-1 receptor antagonist suppresses the release of NE and 5-HT in the hippocampus.
Collapse
|
43
|
Hikichi T, Ishiko S, Takamiya A, Sato E, Mori F, Takahashi M, Yanagiya N, Akiba J, Yoshida A. Scanning laser ophthalmoscope correlations with biomicroscopic findings and foveal function after macular hole closure. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2000; 118:193-7. [PMID: 10676784 DOI: 10.1001/archopht.118.2.193] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To investigate the relation between foveal findings and visual function in eyes with a resolved idiopathic macular hole after vitreous surgery. METHODS We divided 28 eyes with postoperative idiopathic macular hole resolution into 3 groups based on postoperative biomicroscopic foveal findings of complete closure, partial closure, or atrophic closure. To evaluate foveal retinal function, scanning laser ophthalmoscope (SLO) microperimetry was performed preoperatively and 6 months postoperatively. RESULTS Postoperatively in 18 eyes (64%), the foveal images became normal or almost normal and were classified as having complete closure, 6 eyes (21%) were classified as having partial closure, and 4 eyes (14%) as having atrophic closure. The corresponding visual acuity levels 6 months postoperatively were, respectively, 0.10, 0.35, and 0.64 (P<.01) based on LogMAR analysis. Preoperative SLO microperimetry detected an absolute scotoma at the bottom of all macular holes; postoperatively, the absolute scotoma disappeared in the 18 eyes with complete hole closure, but a relative scotoma was detected in 6 eyes. Of 6 eyes with partial closure, 1 had an absolute scotoma and 5 had a relative scotoma. An absolute scotoma was detected in 4 eyes with atrophic closure. CONCLUSIONS After macular hole closure, SLO findings correlate both with biomicroscopic findings and foveal function. Better anatomical foveal recovery in eyes after macular hole closure results in better improvement of vision than in eyes in which the foveal anatomical findings are not as good.
Collapse
|
44
|
Tsutsumi T, Akiyoshi J, Isogawa K, Kohno Y, Hikichi T, Nagayama H. Suppression of conditioned fear by administration of CCKB receptor antagonist PD135158. Neuropeptides 1999; 33:483-6. [PMID: 10657528 DOI: 10.1054/npep.1999.0766] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In order to examine the involvement of CCK in the formation of anxiety, we have investigated whether CCKB receptor antagonist PD135158 suppressed conditioned fear stress. Rats were individually subjected to 30 min of inescapable electric footshock in a chamber with a grid floor. First, the rats were individually subjected to 30 min of footshock. Twenty-four h after the footshock, the rats were again placed in the chamber and observed for 5 min without shocks. PD135158 was administered 30 min before placing the rats in the chamber again. Secondly, PD135158 was administered 30 min before footshock. Thirdly, PD135158 was administered 5 min after footshock. Administration of PD135158 30 min before conditioned fear stress significantly reduced freezing behavior. Administration of PD135158 30 min before footshock also significantly reduced freezing behavior. But, administration of PD135158 5 min after footshock did not significantly reduce freezing behavior. PD135158 blocked not only the acquisition but also the expression of conditioned fear. These results suggest that the CCKB receptor might play an important role in conditioned fear stress and that it might be related to anxiety.
Collapse
|
45
|
Hikichi T, Nomiyama G, Ikeda H, Yoshida A. Vitreous changes after treatment of retinopathy of prematurity. Jpn J Ophthalmol 1999; 43:543-5. [PMID: 10672887 DOI: 10.1016/s0021-5155(99)00108-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To investigate the vitreous findings in patients with cicatricial retinopathy of prematurity (ROP) who underwent retinal cryopexy and/or photocoagulation during the acute phase of the disease. METHODS Vitreous findings were evaluated in 15 patients (29 eyes) with cicatricial ROP by slit-lamp biomicroscopy and indirect ophthalmoscopy. RESULTS The ocular examination revealed that all eyes had extensive vitreous liquefaction that affected a large segment of the vitreous. A great deal of fibrillar condensation of the vitreous was present in membrane-like vitreous fibers that traversed the vitreous cavity to the periphery of the degenerating retina. These vitreous changes were most marked in the areas in which retinal cryopexy and/or photocoagulation had been performed. Despite advanced liquefaction, the posterior cortical vitreous was not separated from the retina in any eyes. CONCLUSION In eyes with ROP that underwent retinal cryopexy and/or photocoagulation during the acute phase of the disease, the vitreous was abnormal, which may contribute to vitreoretinal traction that eventually leads to retinal breaks and detachment.
Collapse
|
46
|
Akiba J, Yanagiya N, Konno S, Hikichi T, Yoshida A. Three-dimensional characteristics of macular pseudoholes using confocal laser tomography. OPHTHALMIC SURGERY AND LASERS 1999; 30:513-7. [PMID: 10929972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
BACKGROUND Epiretinal membranes with macular pseudoholes are sometimes confused with full-thickness macular holes. Because both the natural course and clinical management of the two differ, an accurate differential diagnosis is needed. PATIENTS AND METHODS We obtained three-dimensional images of macular pseudoholes in 12 eyes using the Heidelberg retina tomograph (HRT). Another 15 eyes with a full-thickness macular hole were also studied. In addition, we measured the area and the maximum depth of both types of holes. RESULTS Irregular rippling undulations were frequently observed on the three-dimensional topographic maps around the pseudoholes, whereas elevated cuffs were observed around the full-thickness holes. The maximum depth of the macular pseudoholes (mean, 57 microm) was significantly shallower than that of the full-thickness macular holes (mean, 156 microm; P < 0.01). CONCLUSION Three-dimensional images obtained by the HRT and the measurement of the maximum depth may be useful in differentiating macular pseudoholes from full-thickness macular holes.
Collapse
|
47
|
Hikichi T, Yanagiya N, Kado M, Akiba J, Yoshida A. Posterior vitreous detachment induced by injection of plasmin and sulfur hexafluoride in the rabbit vitreous. Retina 1999; 19:55-8. [PMID: 10048374 DOI: 10.1097/00006982-199901000-00009] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE To investigate whether an injection of plasmin and sulfur hexafluoride (SF6) can induce posterior vitreous detachment (PVD) without vitrectomy. METHODS One eye each of 15 New Zealand white rabbits was assigned to one of three groups. Eyes in group 1 received a vitreous injection of 1 unit of human plasmin (0.1 mL reconstituted in balanced salt solution) and 0.5 mL of SF6; eyes in group 2 received a vitreous injection of plasmin alone; eyes in group 3 received a vitreous injection of SF6 alone. Seven days after injection, all animals were monitored electroretinographically and killed, and the eyes were enucleated. After fixation, scanning electron microscopy was performed. RESULTS In group 1 eyes, the retinal surface was smooth except for the vitreous base, which showed complete separation of the vitreous cortex from the retina, indicating PVD. In group 2 and 3 eyes, sparse collagen fibers remained on the retinal surface. CONCLUSION Vitreous injection of plasmin combined with SF6 can induce PVD without vitrectomy.
Collapse
|
48
|
Hikichi T, Yoshida A, Hasegawa T, Ohnishi M, Sato T, Muraoka S. Wound healing of scleral self-sealing incision: a comparison of ultrasound biomicroscopy and histology findings. Graefes Arch Clin Exp Ophthalmol 1998; 236:775-8. [PMID: 9801893 DOI: 10.1007/s004170050157] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The goal of this study was to compare the morphologic findings of wound healing in scleral self-sealing incisions using ultrasound biomicroscopy and histology. METHODS Using a slit-knife, we made a scleral self-sealing incision in the rabbit eye. At various time points postoperatively, ultrasound biomicroscopy was performed to evaluate wound healing; the eyes then were enucleated and studied histologically. We also performed ultrasound biomicroscopy at various time points postoperatively in patients who received a scleral self-sealing incision during cataract surgery. RESULTS In rabbit eyes, on days 1 and 2 postoperatively, we detected the scleral wound; thereafter, detection became increasingly difficult. On day 7 postoperatively, the wound was undetectable. By light-microscopic observation, the scleral wound was open at 1 day postoperatively. On day 2 postoperatively, fibrovascular tissue barely extended into the wound; on day 5 postoperatively, connective tissue extended through the full thickness of the wound. On day 7 postoperatively, the connective tissue became dense and aligned with the lamella. In human eyes, using ultrasound biomicroscopy, the scleral incision was detectable until 5 days postoperatively, but undetectable at 7 days postoperatively. CONCLUSIONS Ultrasound biomicroscopy demonstrates the stages of wound healing of scleral self-sealing incisions. We believe that careful observation is necessary for approximately 7 days following self-sealing incision cataract surgery.
Collapse
|
49
|
Tsutsumi T, Isogawa K, Kouno Y, Hikichi T, Nagayama H, Akiyoshi J. [Suppression of conditioned fear by administration of CCKB receptor antagonist PD135158]. NIHON SHINKEI SEISHIN YAKURIGAKU ZASSHI = JAPANESE JOURNAL OF PSYCHOPHARMACOLOGY 1998; 18:15-8. [PMID: 9592807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aim of this study is to determine whether or not CCKB receptor antagonist PD135158 suppresses conditioned fear. Rats were individually subjected to 30 min of inescapable electric footshock in a chamber with a grid floor. PD135158 or the vehicle was administered 30 min before placing the rats in the shock chamber again. The rats were observed for 5 min without receiving shock. The administration of PD135158 30 min before conditioned-fear stress significantly reduced freezing behavior. PD135158 blocked the expression of conditioned fear. PD135158 was again administered 30 min before footshock. Then, the rats were individually subjected to 30 min of inescapable electric footshock in the shock chamber. Twenty-four hours after receiving footshock, the rats were again placed in the shock chamber and observed for 5 min without shock administration. The administration of PD135158 30 min before footshock significantly reduced conditioned freezing. PD135158 blocked the anxiety of conditioned fear. PD135158 blocked not only the anxiety, but also the expression of conditioned fear. These results suggest that CCKB receptor might play an important role in conditioned-fear stress. They indicate that CCKB receptor is related to anxiety.
Collapse
|
50
|
Hikichi T, Ohnishi M, Hasegawa T. Transient shallow anterior chamber induced by supraciliary fluid after vitreous surgery. Am J Ophthalmol 1997; 124:696-8. [PMID: 9372730 DOI: 10.1016/s0002-9394(14)70914-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To report the mechanism of transient shallow anterior chamber after vitreous surgery for proliferative diabetic retinopathy. METHOD Using ultrasound biomicroscopy, we examined a patient with transient shallow anterior chamber after vitreous surgery for proliferative diabetic retinopathy. RESULTS On the day after surgery, slit-lamp examination disclosed a shallow anterior chamber that persisted for 1 week and deepened thereafter. Ultrasound biomicroscopy 5 days postoperatively disclosed a narrow angle in the peripheral anterior chamber and supraciliary fluid. At 14 days postoperatively, suprachoroidal fluid could not be detected, and the angle was wide. CONCLUSION The shallow anterior chamber in this patient was caused by supraciliary fluid after vitreous surgery.
Collapse
|