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Biomedical subjects

Y Tano

Publications and source records attributed to Y Tano.

At least 19 recordsLinked to original sources
PubMed2006

Pars plana vitrectomy with peripheral retinotomy after injection of preoperative intravitreal tissue plasminogen activator: a modified procedure to drain massive subretinal haemorrhage.

AIMS: To report outcome of a modified procedure for draining massive subretinal haemorrhages (SRHs). METHODS: The charts of eight consecutive eyes from eight patients with massive SRHs extending to the periphery and involving two or more quadrants with haemorrhagic and bullous retinal detachment were reviewed. Tissue plasminogen activator (tPA) was injected intravitreally 12-24 h preoperatively; vitrectomy was carried out with peripheral retinotomy, drainage of the SRH from the retinotomy using perfluorocarbon liquid and gas tamponade with prone positioning postoperatively. RESULTS: The preoperative visual acuities ranged from light perception to 20/200. Most of the subretinal haematomas moved postoperatively to the vitreous cavity through the peripheral retinotomy using perfluorocarbon liquid. Residual SRHs were drained from the anterior chamber at the bedside after prone positioning overnight. SRH recurred in one eye 14 months postoperatively and was successfully retreated. No other serious complications developed. The final visual acuity improved in seven eyes (range 20/1000-20/60). Polypoidal lesions in choroidal vasculatures were present in three of seven patients. CONCLUSIONS: The technique seems safe and effective for treating massive SRH. However, visual recovery is limited by the underlying macular pathology. Polypoidal choroidal vasculopathy, other than age-related macular degeneration, may be another cause of massive SRHs.

Aged↗
PubMed2006

Intravitreal injection of bevacizumab for choroidal neovascularisation associated with pathological myopia.

AIM: To assess the efficacy and safety of an intravitreal injection of bevacizumab (Avastin(R)) for myopic choroidal neovascularisation (mCNV). METHODS: Intravitreal bevacizumab (1 mg) was injected into eight eyes of eight patients with mCNV in this non-randomised, interventional case series. The best-corrected visual acuity (BCVA) was measured and the optical coherence tomography (OCT) and fluorescein angiography findings were examined before and after treatment. The minimum follow-up time was 3 months. RESULTS: The mean BCVA was 0.26 before treatment and 0.51 at the last visit (p = 0.009). The BCVA improved to two or more lines in six eyes (75%) and remained the same in two eyes (25%). Leakage from the mCNV on fluorescein angiography decreased in seven eyes (87.5%). The choroidal neovascularisation area on fluorescein angiography (p = 0.049) and the foveal thickness on OCT images decreased significantly (p = 0.027) after the treatment. No major complications developed. CONCLUSION: Intravitreal injection of bevacizumab seems to be an effective and safe treatment for mCNV.

Adult↗
PubMed2006

Development of inactivated poliovirus vaccine derived from Sabin strains.

In the course of Sabin-inactivated poliovirus vaccine (S-IPV) development, we have established high-yield virus production techniques based on Vero cell micro-carrier cultures. Development of specific ELISA tests to quantify the antigen content of S-IPV has been achieved. To adjust the immunogenicity of S-IPV so as to be comparable with the conventional-IPV, a new formulation was determined using a potency test using rats. The reformulated S-IPV was shown to be efficacious for the immunization of monkeys.

Animals↗
PubMed2005

Malaria transmission dynamics in central Côte d'Ivoire: the influence of changing patterns of irrigated rice agriculture.

The dynamics of malaria transmission was studied comparatively in the villages of Zatta and Tiemelekro, central Cote d'Ivoire, from February 2002 to August 2003. Prominent agroecosystems in these villages are irrigated rice growing and vegetable farming, respectively. Mosquitoes (Diptera: Culicidae) were collected on human bait at night and by pyrethrum knock-down spray sheet collections at four randomly selected sentinel sites in each village. In 2002, for a total of 96 man-nights per village, 7716 mosquitoes were collected in Zatta and 3308 in Tiemelekro. In 2003, with half the sampling effort, 859 and 2056 mosquitoes were collected in Zatta and Tiemelekro, respectively. Anopheles gambiae Giles s.l. was the predominant mosquito and the key malaria vector throughout, followed by An. funestus Giles. Anthropophily among adult female Anopheles exceeded 95% in both villages. Comparison between years revealed that the biting rate of An. gambiae s.l. in Zatta decreased several-fold from 49.3 bites per person per night (b/p/n) in 2002 to 7.9 b/p/n in 2003 (likelihood ratio test (LRT) = 1072.66; P < 0.001). Although the biting rate remained fairly constant in Tiemelekro, the difference between years was significant (16.1 vs. 18.2 b/p/n; LRT = 148.06; P < 0.001). These observations were paralleled by a marked decrease in the infective rate of An. gambiae s.l. in Zatta (4.6-1.2%), and an increase in Tiemelekro (3.1-7.6%). Meanwhile, the entomological inoculation rate of An. gambiae s.l. decreased 21-fold in Zatta, from 789 to 38 infective bites per person per year (ib/p/y), whereas it remained high in Tiemelekro (233 vs. 342 ib/p/y). The interruption of irrigated rice growing in Zatta in 2003, consequential to a farmers' conflict over land, might be the underlying cause for the significant reduction in malaria transmission, whereas more stable conditions occurred in Tiemelekro.

Agriculture↗
PubMed2005

Choroidal neovascularisation in pathological myopia: an update in management.

Choroidal neovascularisation (CNV) secondary to pathological myopia is an important cause of significant visual impairment in young and middle aged adults globally and is particularly prevalent in Asian populations. In the past few years, there have been rapid advancements in the different treatments for myopic CNV. The purpose of this perspective is to give an overview of the natural history of myopic CNV and the various treatment options including laser photocoagulation, photodynamic therapy, sub-macular surgery, and macular translocation surgery. Future directions in the management of myopic CNV are also discussed.

Choroidal Neovascularization↗
PubMed2004

Application of femtosecond ultrashort pulse laser to photodynamic therapy mediated by indocyanine green.

BACKGROUND/AIMS: To evaluate treatment with high peak power pulse energy by femtosecond ultrashort pulse laser (titanium sapphire laser) delivered at an 800 nm wavelength for corneal neovascularisation using photodynamic therapy (PDT) mediated by indocyanine green (ICG). METHODS: Using a gelatin solid as an in vitro corneal model, the safety of laser power was studied to determine if it degenerated gelatin with or without ICG. The authors then induced corneal neovascularisation in rabbit eyes by an intracorneal suturing technique. Fluorescein angiography was used to evaluate occlusion before PDT and 0, 1, 3, and 10 days after PDT. The authors performed light microscopy with haematoxylin eosin staining and transmission electron microscopy to determine thrombosis formation in the neovascular regions. RESULTS: The threshold of peak laser power density ranged from 39 to 53 W/cm(2). Laser irradiation was started 30 seconds after a 10 mg/kg ICG injection, and all irradiated segments were occluded at 0, 1, 3, and 10 days at 3.8 J/cm(2). Light and electron microscopy documented thrombosis formation in the neovascular region. CONCLUSION: Femtosecond pulse laser enhanced by ICG can be used for PDT. Because of effective closure of corneal neovascularisation at a low energy level, the high peak power pulse energy of the femtosecond pulse laser might be more efficacious than continuous wave laser for use with PDT.

Animals↗
PubMed2004

Features of retinal arterial macroaneurysms in patients with uveitis.

AIM: To determine the frequency and clinical characteristics of retinal arterial macroaneurysms in patients with uveitis. METHODS: A retrospective review of the clinical, photographic, and angiographic records of 1007 patients with uveitis, examined at the Osaka University Hospital uveitis clinic between January 1995 and April 2002, was performed. All of the records were examined to determine whether macroaneurysms were present, and when present, to determine the laterality, type, location, clinical course, and the presence of associated systemic and ocular diseases. RESULTS: Of the 1007 patients with uveitis, only 14 (1.4%) had macroaneurysms. 12 of these 14 patients had peripheral multifocal chorioretinitis (PMC), and five of these 12 were diagnosed with sarcoidosis and the other seven without sarcoidosis. There was only one case with sarcoidosis without PMC, and the remaining case was uveitis of unknown origin. There were 18 macroaneurysms in all cases and 17 (94.4%) were the exudative type, and the remaining one was the haemorrhagic type. Two patients had been treated for systemic hypertension but the others had no signs of systemic hypertension or cardiovascular disease. CONCLUSIONS: Macroaneurysms are not characteristically found in patients with uveitis, but the majority are found in patients with PMC. The majority of the macroaneurysms were the exudative type, and the conclusion is that patients with PMC should be carefully examined for exudative macroaneurysms.

Adult↗
PubMed2002

HGF/NK4 inhibited VEGF-induced angiogenesis in in vitro cultured endothelial cells and in vivo rabbit model.

AIMS/HYPOTHESIS: As vascular endothelial growth factor (VEGF) plays a pivotal role in the development of diabetic retinopathy, inhibition of angiogenesis induced by VEGF is crucial to treat diabetic retinopathy. HGF (hepatocyte growth factor)/NK4, containing the N-terminal hairpin domain and the four subsequent kringle domains of HGF, is considered as a specific antagonist for HGF. Our aim was to explore the inhibitory effects of HGF/NK4 on angiogenesis induced by VEGF. METHODS: To analyze the in vivo angiogenesis, we used rabbit corneal micropocket assay. Proliferation and migration of human endothelial cells, expression of ets-1, an essential transcription factor for angiogenesis, and the phosphorylation of extracellular signal-regulated kinase (ERK) was examined with or without HGF/NK4. RESULTS: Using corneal micropocket assay, in vivo administration of HGF/NK4 inhibited angiogenesis induced by VEGF. HGF/NK4 inhibited proliferation and migration of human endothelial cells induced by VEGF in a dose-dependent manner. Interestingly, VEGF-mediated phosphorylation of ERK was significantly attenuated by HGF/NK4. Of importance, HGF/NK4 attenuated the increase in ets-1 protein stimulated by VEGF. Nevertheless, HGF/NK4 did not affect phosphorylation of VEGF receptor-2 [kinase domain region (KDR)/foetal liver kinase (Flk)-1]. Although tyrosine phosphatase inhibitor (Na(3)VO(4)), or okadaic acid, serine-threonin kinase inhibitor, did not prevent the inhibition of ERK phosphorylation by HGF/NK4, co-incubation of HGF/NK4 with VEGF significantly diminished mitogen-activated protein (MAP) ERK kinase (MEK) phosphorylation (p<0.01). CONCLUSIONS/INTERPRETATION: Overall, HGF/NK4 inhibited angiogenesis induced by VEGF through inhibition of phosphorylation of ERK and ets-1 expression in in vitro cultured endothelial cells and in vivo rabbit model.

Animals↗
PubMed2001

Functional Kir7.1 channels localized at the root of apical processes in rat retinal pigment epithelium.

1. The inwardly rectifying K+ channel current (IK(IR)) recorded from isolated retinal pigmented epithelial (RPE) cells showed poor dependence on external K+ ([K+]o) and low sensitivity to block by Ba2+. We examined the molecular identity and specific subcellular localization of the KIR channel in RPE cells. 2. The Kir7.1 channel current heterologously expressed in HEK293T cells (human embryonic kidney cell line) showed identical properties to those of the RPE IK(IR), i.e. poor dependence on [K+]o and low sensitivity to Ba2+ block. 3. Expression of Kir7.1 mRNA and protein was detected in RPE cells by RT-PCR and immunoblot techniques, respectively. 4. Immunohistochemical studies including electron microscopy revealed that the Kir7.1 channel was localized specifically at the proximal roots of the apical processes of RPE cells, where Na+,K+-ATPase immunoreactivity was also detected. 5. The middle-distal portions of apical processes of RPE cells in the intact tissue exhibited immunoreactivity of Kir4.1, a common KIR channel. In the isolated RPE cells, however, Kir4.1 immunoreactivity was largely lost, while Kir7.1 immunoreactivity remained. 6. These data indicate that the only IK(IR) recorded in isolated RPE cells is derived from the functional Kir7.1 channel localized at the root of apical processes. Co-localization with Na+,K+-ATPase suggests that the Kir7.1 channel may provide the pathway for recycling of K+ to maintain pump activity and thus is essential for K+ handling in RPE cells.

Amino Acid Sequence↗
PubMed2001

Nestin-EGFP transgenic mice: visualization of the self-renewal and multipotency of CNS stem cells.

We generated transgenic mice carrying enhanced green fluorescent protein (EGFP) under the control of the nestin second-intronic enhancer (E/nestin:EGFP). Flow cytometry followed by in vitro assays revealed that in situ EGFP expression in the embryonic brain correlated with the mitotic index, the cogeneration of both neurons and glia, and the frequency of neurosphere formation in vitro. High-level EGFP expressors derived from embryos included a distinct subpopulation of cells that were self-renewable and multipotent, criteria that define neural stem cells (NSCs). Such cells were largely absent among lower-level or non-EGFP expressors, thereby permitting us to enrich for NSCs using EGFP expression level. In adults, although E/nestin:EGFP-positive cells included the NSC population, the frequency of neurosphere formation did not correlate directly with the level of EGFP expression. However, moderately EGFP-expressing cells in adults gained EGFP intensity when they formed neurospheres, suggesting embryonic and adult NSCs exist in different microenvironments in vivo.

Animals↗
PubMed2001

Topographic analysis of astigmatism induced by scleral shortening in pig eyes.

BACKGROUND: Corneal astigmatism is a severe postoperative problem in foveal translocation surgery. We evaluated the corneal astigmatism induced by scleral shortening in pig eyes in vitro. METHODS: We created three sizes of scleral shortening in pig eyes and examined the preoperative and postoperative corneal astigmatism. The three sizes of scleral shortening were; 6 mm x 12 mm, 9 mm x 12 mm, and 6 mm x 16 mm (radial x circumferential). The shortenings were created 11 mm from the limbus with 10 eyes in each group. Videokeratographic measurements were performed using the CAS System 2000, preoperatively and postoperatively, and the astigmatism caused by the scleral shortening was evaluated. RESULTS: The surgically-induced astigmatism was 2.1 +/- 1.2 diopters (D) in the 6 mm x 12 mm group, 5.2+/-1.5 D in the 9 mm x 12 mm group, and 3.7+/-1.0 D in the 6 mm x 16 mm group. Corneal astigmatism caused by scleral shortening depended on both the radial and circumferential shortening. Pre- and postoperative topographic corneal maps showed an irregular astigmatism pattern (lazy bowtie pattern). Because the central zone of the cornea showed a relatively regular astigmatism, the corneal astigmatism induced by scleral shortening did not affect the predicted corneal acuity. CONCLUSIONS: In foveal translocation surgery with scleral shortening, an excessive scleral resection in the radial direction can cause clinically intolerable regular and irregular astigmatism. Minimal scleral shortening that will satisfy the required translocated distance is recommended to reduce the risk/benefit ratio.

Animals↗
PubMed2001

Visual function after foveal translocation with 360-degree retinotomy and simultaneous torsional muscle surgery in patients with myopic neovascular maculopathy.

PURPOSE: To assess functional and anatomical outcomes after foveal translocation with 360-degree retinotomy and simultaneous torsional muscle surgery in patients with myopic neovascular maculopathy. METHODS: Foveal translocation with 360-degree retinotomy was performed in 11 eyes of 11 patients with myopic neovascular maculopathy. Ten eyes had simultaneous torsional muscle surgery with recession of the superior oblique muscle and tucking of the inferior oblique muscle. Silicone oil removal with or without intraocular lens implantation was performed 2 to 8 weeks after the primary procedure. Visual acuity, binocular function, and degree of cyclotorsion were assessed preoperatively and postoperatively. Angles of retinal and globe rotation, distance of foveal shift, and surgical complications were also investigated. RESULTS: With a mean postoperative follow-up of 6.2 months (range, 3 to 13 months), vision improved (greater than 0.2 logarithm of minimal angle of resolution [logMAR] units) in eight eyes, was unchanged in two eyes, and worsened (greater than 0.2 logMAR units) in 1 eye. Seven of 11 eyes (64%) had a final visual acuity of 20/50 or better. Five patients developed or maintained binocular fusion, four patients continued to have suppression, and two patients developed diplopia that was managed by spectacles with Fresnel prisms. Subjective cyclotorsion was less than 8 degrees in 10 eyes. Mean retinal and globe rotations were 23.4 degrees and 19.8 degrees, respectively. Average size of the choroidal neovascular membrane was 0.8 disk diameter, whereas the average distance of foveal shift was 1.5 disk diameter. After the primary procedure, three eyes developed retinal detachment, one eye macular hole, and one eye proliferative vitreoretinopathy. These complications were successfully managed by additional surgery. CONCLUSION: Foveal translocation with 360-degree retinotomy is effective in restoring vision in some patients with myopic neovascular maculopathy. Although the development of torsional diplopia is generally obviated by simultaneous extraocular muscle surgery, a relatively high incidence of surgical complications should be taken into account with this procedure.

Aged↗
PubMed2001

Macular translocation: unifying concepts, terminology, and classification.

PURPOSE: To describe some unifying concepts, terminology, and classification of macular translocation so as to facilitate communication within the scientific community. METHODS: A panel of ophthalmologists with expertise in macular translocation reviewed available data and developed some unifying concepts, terminology, and classification of macular translocation. RESULTS: Macular translocation may be defined as any surgery that has a primary goal of relocating the central neurosensory retina or fovea intraoperatively or postoperatively specifically for the management of macular disease. It may be classified according to the size of the retinotomy and, where applicable, the technique of chorioscleral shortening used. The direction of macular translocation is denoted by the movement of the neurosensory macula relative to the underlying tissues. Effective macular translocation may be defined as successful intraoperative or postoperative relocation of the fovea overlying a subfoveal lesion to an area outside the border of the lesion. The concepts of minimum desired translocation and median postoperative foveal displacement can give some useful idea of the likelihood of effective macular translocation before surgery. CONCLUSIONS: Use of a common standardized terminology for macular translocation will facilitate communication within the scientific community and enhance further research in this area. However, the definitions, terms, classification, and concepts concerning macular translocation are likely to continue to evolve as macular translocation undergoes further modifications and refinements.

Humans↗
PubMed2001

Indocyanine green facilitates removal of epiretinal and internal limiting membranes in myopic eyes with retinal detachment.

PURPOSE: To describe the use of intravitreal indocyanine green as an aid to identifying epiretinal membranes and internal-limiting membranes during surgery for a retinal detachment resulting from a macular hole. METHODS: A 62-year-old man who had a retinal detachment resulting from a macular hole underwent vitrectomy. During the surgery, intravitreal indocyanine green was injected intravitreally. RESULTS: The internal-limiting membrane was stained green, but the epiretinal membrane was unstained. Because the epiretinal membrane and internal-limiting membrane were clearly identified, they could be completely removed. The clinical observations of the epiretinal membrane and internal-limiting membrane excised were confirmed by electron microscopy. Successful reattachment was obtained without damage to the retina. CONCLUSION: Removal of epiretinal membrane and internal-limiting membrane can be facilitated by using intravitreal indocyanine green during vitrectomy. We recommend further studies to confirm the benefit of this technique.

Basement Membrane↗
PubMed2001

Epithelial pigment slide in contact lens wearers: a possible marker for contact lens-associated stress on corneal epithelium.

PURPOSE: To compare the incidence of epithelial pigment slide among wearers of various types of contact lenses. METHODS: Prospectively, we studied 432 eyes of 432 patients. The patients were separated into 6 groups: hard contact lens (HCL) wearers (n = 166), conventional soft contact lens (CSCL) wearers (n = 30), extended disposable lens (EDCL) wearers (n = 46), frequent replacement SCL (FRCL) wearers (n = 60), daily disposable SCL (DDCL) wearers (n = 65), and normal controls (n = 65). The incidence of prominent pigment slide, defined as spike-like epithelial opacities in the corneal limbus and longer than 1 mm from the base to the apex of the wedges-shaped process detected by slit-lamp examination, was compared in these 6 groups. The relationship between the incidence of prominent pigment slide and the length of contact lens wear was examined. RESULTS: The overall incidence of prominent pigment slide in the CSCL, EDCL, HCL, FRCL, DDCL, and normal groups was 63.3, 23.9, 13.9, 8.3, 7.7, and 4.6%, respectively. The incidence of prominent pigment slide in the CSCL and EDCL groups was significantly higher than that in the control group. A higher incidence of prominent pigment slide was correlated with longer wearing period in each group. CONCLUSIONS: The presence of epithelial pigment slide may be a marker for contact lens-associated stress to the corneal epithelium.

Biomarkers↗