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Biomedical subjects

Y Ikuno

Publications and source records attributed to Y Ikuno.

At least 19 recordsLinked to original sources
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↗
PubMed2002

Comparative biochemical studies of carotenoids in catfishes.

The carotenoids of 12 species of Siluriformes fishes (eight families) were investigated from a comparative biochemical point of view. The patterns of carotenoids in catfishes belonging to the family Siluridae were quite different from those of the other seven families of catfishes (Bagridae, Amblycipitidae, Clariidae, Plotosidae, Ictaluridae, Callichthyidae and Malapteruridae). 7, 8-Dihydro-beta-carotene; 7, 8, 7', 8'- and 7, 8, 9, 10-tetrahydro-beta-carotene; (3R)-7', 8'-dihydro-beta-cryptoxanthin; 7, 8-dihydrolutein A; 7, 8-dihydrolutein B; parasiloxanthin; 7', 8'-dihydroparasiloxanthin; and 4 or 4'-hydroxyparasiloxanthin were characteristic carotenoids found in only one family, Siluridae, and these carotenoids accounted for 24-60% of total carotenoids. In catfishes belonging to the other seven families except Siluridae, the carotenoid patterns were very similar and the most predominant carotenoid was zeaxanthins (23-56%).

Animals↗
PubMed2001

Comparison of three techniques of foveal translocation in patients with subfoveal choroidal neovascularization resulting from age-related macular degeneration.

PURPOSE: To report the results of three methods of foveal translocation in the presence of subfoveal choroidal neovascular membrane resulting from age-related macular degeneration. METHODS: We treated 51 eyes of 51 consecutive patients with subfoveal choroidal neovascular membranes resulting from age-related macular degeneration with one of three techniques of foveal translocation surgery: foveal translocation with partial retinotomy (n = 6), limited translocation (n = 9), and translocation with 360-degree retinotomy (n = 36). All patients were followed for at least 6 months postoperatively. The size of the choroidal neovascular membrane and the amount of foveal displacement, the best-corrected visual acuity, and complications were recorded preoperatively and postoperatively. RESULTS: The mean distance of the foveal translocation was greater in the 360-degree retinotomy group (3340 microm) than in the partial retinotomy (1060 microm, P <.001) and the limited translocation groups (1120 microm, P <.001). A final visual acuity of 20/200 or better was achieved in two eyes (33%) in the partial retinotomy group, seven eyes (78%) in the limited translocation group, and 23 eyes (64%) in the 360-degree retinotomy group. The final visual acuity improved by 0.2 logarithm of minimal angle of resolution (logMAR) unit or more in one eye (17%), one eye (11%), and seven eyes (19%), respectively. The final visual acuity was maintained within 1 line in zero eyes, five eyes (56%), and 19 eyes (53%), respectively. A retinal detachment developed postoperatively in five eyes (83%), zero eyes (0%), and 15 eyes (42%), respectively. CONCLUSIONS: A significant number of patients improved or maintained best-corrected visual acuity after translocation with 360-degree retinotomy, and limited translocation, whereas translocation with 360-degree retinotomy is suitable for larger choroidal neovascular membranes because it resulted in the greatest foveal displacement among the three translocation procedures.

Aged↗
PubMed2000

Src family kinases negatively regulate platelet-derived growth factor alpha receptor-dependent signaling and disease progression.

We tested the hypothesis that Src family kinases (SFK) contribute to c-Cbl-mediated degradation of the platelet-derived growth factor (PDGF) alpha receptor (alphaPDGFR). Using either a receptor mutant that does not engage SFKs (F72/74), or cells that that lack SFKs, we found that SFKs contributed to degradation of the alphaPDGFR. Overexpression of c-Cbl also reduced the receptor half-life, but only if the receptor was able to engage SFKs. In cultured cells, prolonging the half-life of the receptor correlated with enhanced signaling and more efficient S phase entry, whereas accelerating receptor degradation had the opposite effect. Consistent with these tissue culture findings, there was a statistically significant increase in the onset of a proliferative retinal disease when animals were injected with cells expressing the F72/74 receptor, as compared with cells expressing the WT receptor. Our findings suggest that SFKs cooperate with c-Cbl to negatively regulate the alphaPDGFR, and that the SFK/c-Cbl suppression of alphaPDGFR output is relevant to the onset and progression of a proliferative disease.

3T3 Cells↗
PubMed2000

Adsorption and pharmacokinetics of cyclosporin A in relation to mode of infusion in bone marrow transplant patients.

Two main factors that affect the pharmacokinetics of cyclosporin A (CsA) during 24-h durable intravenous (DIV) administration have been reported, namely physiological changes after bone marrow transplantation, and blood sampling through indwelling lines. In addition, it has been found that infusion sets made of polyvinyl chloride (PVC) markedly adsorb CsA. We conducted in vitro adsorption studies of CsA on infusion sets, and the administration routes that are used in the treatment of patients with bone marrow transplantation. We also examined the effects of administration route on CsA pharmacokinetics in clinical practice. The in vitro adsorption study using 30-mm segments of lumen from commercially available infusion sets showed that the degree of CsA adsorption per area of lumen made of PVC was significantly higher than that in those made of polyethylene (PE) or polybutadiene (PB), which showed no adsorption of CsA. Due to its adsorption, use of infusion sets made of PVC resulted in about a 40-50% loss of CsA dose, which affected the pharmacokinetic parameters during 24-h DIV, while those made of PE and PB did not. The use of non-PVC infusion sets should allow for accurate monitoring of CsA results, and provide cost benefit in the treatment of bone marrow transplantation.

Adsorption↗
PubMed2000

Treatment of childhood acute myelogenous leukemia with allogeneic and autologous stem cell transplantation during the first remission: a report from the Kyushu-Yamaguchi Children's Cancer Study group in Japan.

A total of 64 newly diagnosed acute myelogenous leukemia patients (except FAB M3 and/or Down syndrome) under 18 years of age were consecutively enrolled into the study. Patients having an HLA-identical sibling (allo group) were assigned to undergo allogeneic bone marrow transplantation (allo BMT) in the first complete remission (CR). Others (non-allo group) were assigned to undergo autologous peripheral blood stem cell transplantation (PBSCT) or autologous BMT (auto BMT). Conditioning regimen was busulfan + melphalan for all transplantation. Of 64 patients (allo group 24; non-allo group 40), 59 (92.2%) achieved a CR. Eighteen relapses occurred (allo group 4; non-allo group 14) and 6 died during the first CR. The 5-year event-free survival (EFS) rate was 53.3 +/- 6.4% at a median follow-up period of 45 months. The 5-year EFS rates of allo and non-allo groups were 70.8 +/- 9.3% and 43.0 +/- 8.1%, respectively (p = .08). The EFS rates at 5 years post-transplant for allo BMT from an HLA-identical sibling (n = 18), PBSCT (11), and auto BMT (6) were 88.1 +/- 7.9%, 41.6 +/- 19.7%, and 83.3 +/- 15.2%, respectively. The outcome of allo BMT was superior to that of autograft. Auto BMT rather than PBSCT might contribute to a long-term survival in case of no available HLA-identical siblings.

Adolescent↗
PubMed2000

Attenuation of experimental proliferative vitreoretinopathy by inhibiting the platelet-derived growth factor receptor.

PURPOSE: The work from numerous laboratories has led to the idea that the growth factors such as platelet-derived growth factor (PDGF) contribute to proliferative vitreoretinopathy (PVR) in experimental models of the disease, as well as in humans. In support of this idea, the authors have previously reported that cells unable to respond to PDGF had a greatly reduced PVR potential, compared with PDGF-responsive versions of the same cells. The goal of this study was to test the effect of blocking the output of the PDGF receptor in an experimental model of PVR. METHODS: Polymerase chain reaction-based site-directed mutagenesis was used to generate point mutations in the human PDGF alpha receptor (alphaPDGFR) cDNA, which resulted in single amino acid substitutions. These changes were based on naturally occurring point mutations in the c-kit receptor tyrosine kinase, which suppresses the function of wild-type c-kit. A truncated alphaPDGFR was also made, in which the receptor ended just after the juxtamembrane domain. As with the point mutants, truncated receptors have been shown to block the action of wild-type receptors. All the alphaPDGFR mutants were introduced into cells that naturally express the wild-type receptor, and the PDGF-dependent output of the resultant cell lines was determined. In addition, the PVR potential of cell lines expressing the mutant receptors was tested in a PVR rabbit model. RESULTS: Although the mutants differed in their ability to suppress PDGF-dependent signaling of the wild-type receptor, each mutant effectively blocked cell cycle progression. When expressed in rabbit conjunctival fibroblasts, a cell line that effectively induces PVR, the mutant receptors blocked PVR to various degrees. The most effective receptor was the truncated mutant. CONCLUSIONS: These data suggest that the alphaPDGFR plays an important role in PVR. In addition, these mutant receptors appear to have therapeutic potential for prevention of this blinding disease.

Animals↗
PubMed1999

Nonvitrectomizing vitreous surgery: a strategy to prevent postoperative nuclear sclerosis.

OBJECTIVE: The development or progression of postoperative nuclear sclerosis is the most common complication of successful vitrectomy in elderly patients. The authors treated idiopathic epimacular proliferation (EMP) with nonvitrectomizing vitreous surgery in an attempt to prevent postoperative nuclear sclerosis. DESIGN: Prospective, nonrandomized, comparative case series. PARTICIPANTS: The authors surgically removed membranes from the sensory retina in 21 eyes of 21 patients with EMP. INTERVENTION: Neither intravitreal infusion nor vitrectomy of any kind was performed during the procedure. The peeled membrane was left floating in the vitreous cavity in 11 (group 1) eyes and removed in 10 eyes (group 2). Nonoperated fellow eyes served as controls. MAIN OUTCOME MEASURES: Visual acuity, slit-lamp and/or Scheimpflug photography, and refractometry were performed pre- and postoperatively to evaluate changes in the degree of lenticular opacity. RESULTS: There was no difference in the rate of development or progression of nuclear sclerosis or the degree of myopic shift between operated and control eyes during the postoperative follow-up period (mean, 9.7 months). No serious complications were noted. There was no difference in postoperative course between patients in the two operative groups. CONCLUSIONS: Although interpretation of the results of this study is limited due to its small size and short follow-up, nonvitrectomizing vitreous surgery seems to decrease the postoperative development or progression of nuclear sclerosis in patients with idiopathic EMP.

Aged↗
PubMed1999

Bilateral basal ganglial necrosis after allogeneic bone marrow transplantation in a child with Kostmann syndrome.

A 6-year-old girl underwent allogeneic BMT from a matched sibling donor for the treatment of Kostmann syndrome. She suddenly became drowsy on day 30 after BMT, and lost consciousness 2 days later. Cranial CT scan showed symmetrical lesions suggesting bilateral necrosis in the basal ganglia. Clinical and laboratory investigations failed to reveal any evidence of neurometabolic disease.

Basal Ganglia↗
PubMed1998

Complete epiretinal membrane separation in highly myopic eyes with retinal detachment resulting from a macular hole.

PURPOSE: Epiretinal membranes (ERMs) in highly myopic eyes may result in macular holes and subsequent retinal detachment. However, removing friable, thin ERMs from detached retinas is often difficult. We report the efficacy of a diamond-dusted silicone cannula in the removal of ERMs from detached retinas. METHODS: Seventeen consecutive highly myopic eyes (16 patients) with retinal detachment underwent pars plana vitrectomy with gas tamponade. Peeling of the ERM adjacent to the macular hole was performed using either conventional tools (n = 11) or a diamond-dusted silicone cannula (n = 6). The rate of complete membrane peeling and the effect of membrane removal on the anatomic success rate were compared between groups. RESULTS: Retinal reattachment occurred in 13 (92.9%) of the 14 eyes in which the ERM was removed completely; redetachment occurred in the other three eyes, with further surgical interventions in two eyes. The reattachment rate was significantly higher (P = .005) when ERM removal was complete than when there was residual ERM. In the initial surgery, the ERM was successfully removed in all 6 eyes (100%) in the diamond-dusted silicone cannula group and in 5 of 11 eyes (45.5%) in the conventional group (P = .041); the reattachment rate was 100% in the diamond-dusted silicone cannula group and 45.5% in the conventional group (P = .005). When a second surgery was performed, the use of the diamond-dusted silicone cannula was also better than conventional tools for removing the residual ERMs, resulting in retinal reattachment. CONCLUSION: In highly myopic eyes with a macular hole and subsequent retinal detachment, complete ERM removal is closely related to successful retinal reattachment. The diamond-dusted silicone cannula appears to be more effective than conventional tools for removing ERM and may increase the anatomic success rate. Because of the limitations of a small series, a prospective, randomized trial is required to confirm the current beneficial results of using a diamond-dusted silicone cannula.

Aged↗
PubMed1998

Tractional retinal detachment after branch retinal vein occlusion. Influence of disc neovascularization on the outcome of vitreous surgery.

OBJECTIVE: This study aimed to investigate the influence of disc neovascularization on the outcome of vitreous surgery for tractional retinal detachment (TRD) after branch retinal vein occlusion (BRVO). DESIGN: The study design was a retrospective case series. PARTICIPANTS: Twenty-two eyes of 22 patients who had undergone vitrectomy for TRD after BRVO at the Osaka National Hospital (Osaka, Japan) or the Surugadai Hospital of Nihon University (Tokyo, Japan) between 1985 and 1995 participated. Seven (32%) of 22 eyes had a TRD secondary to neovascularization of the optic disc (NVD) and neovascularization elsewhere (NVE; group I), and 15 (68%) had a TRD with NVE without NVD (group II). MAIN OUTCOME MEASURES: Visual acuities and retinal reattachment rates were measured. RESULTS: Sixteen (73%) of the 22 study eyes showed severe vitreous hemorrhage before surgery, and 11 eyes (50%) had received laser photocoagulation treatment before surgery. Fourteen (64%) of the study eyes achieved total retinal reattachment after initial vitrectomy, and 19 eyes (86%) were reattached completely at final examination. Thirteen eyes (59%) achieved a visual acuity of better than 0.1. Group I patients had a significantly higher rate of recurrent combined traction rhegmatogenous retinal detachment (P = 0.01) and a significantly worse final visual outcome (P = 0.01). CONCLUSIONS: Better surgical results are expected in eyes without NVD than with NVD among patients who undergo vitrectomy for TRD after BRVO. Although the authors were unable to determine the reason for this difference in the current study, they speculate that the degree of retinal nonperfusion, diffusible angiogenic factors, and distance of the site of occlusion from the disc may each affect visual and anatomic outcomes in these eyes.

Aged↗
PubMed1998

Photocoagulation and fluid-gas exchange to treat persistent macular holes after prior vitrectomy. A pilot study.

OBJECTIVE: This study aimed to determine the efficacy of photocoagulation to the retinal pigment epithelial (RPE) cells and fluid-gas exchange (FGX) in the treatment of persistent macular holes. DESIGN: A clinical trial. PARTICIPANTS: Thirteen eyes of 12 patients who had undergone photocoagulation to the RPE and FGX for persistent macular holes after initial vitrectomy and gas tamponade were examined. All eyes had persistent full-thickness macular holes (diameter range, 290-820 microns; 610 +/- 190, mean +/- standard deviation) and no vitreous cortex around the holes on biomicroscopic examination. INTERVENTION: Argon laser photocoagulation was applied to the RPE in the hole bed, and FGX with 20% sulfur hexafluoride was then performed, followed by 2 weeks with the patient in a prone position. The follow-up period of the patients ranged from 3 to 18 months (10.2 +/- 4.2; mean +/- standard deviation). MAIN OUTCOME MEASURES: Anatomic success and final visual outcome were measured. RESULTS: Macular holes were closed successfully after treatment in 12 (92%) of 13 eyes, and visual acuity improved 2 or more lines in 6 eyes (46%). Two eyes (15%) attained visual acuities of 20/40 or better, and seven eyes (54%) attained 20/67 or better visual acuity. There were no intraoperative complications. Cataract formation or progression was recognized during follow-up in five (83%) of six phakic eyes. CONCLUSIONS: Although this study includes only a small number of patients, it suggests that photocoagulation and FGX can be effective in the treatment of persistent macular holes.

Aged↗
PubMed1998

Donor leukocyte infusion after allogeneic bone marrow transplantation was not effective for relapsed rhabdomyosarcoma.

A 10-year-old boy with metastatic rhabdomyosarcoma had an HLA-identical sibling and received an allogeneic BMT. Recurrence was detected in the BM as the only site of treatment failure 12 months after BMT. Donor leukocyte infusion (DLI) was chosen as salvage therapy. Although sufficient cells (a total of 29.7 x 10(7)/kg) were infused, no signs of acute GVHD nor BM aplasia occurred and the patient died of disease progression 9 months after DLI.

Bone Marrow Transplantation↗
PubMed1998

Assessment of cardiac function and gene expression at an early phase after myocardial infarction.

The purpose of this study was to examine left ventricular function and cardiac gene expressions at an acute phase after myocardial infarction (MI). MI was induced in rats by ligation of the left coronary artery. Two days after MI, we performed Doppler-echocardiography and measured the systolic and diastolic function. We then analyzed the contractile protein and extracellular matrix mRNAs of cardiac tissues in the infarcted region, including the adjacent noninfarcted myocardium (the adjacent noninfarcted myocardium) and the remote noninfarcted myocardium, by Northern blot hybridization. Fractional shortening decreased significantly to 28%. Peak early diastolic filling wave (E wave) velocity increased in MI rats (MI; 90 +/- 3 cm/s versus the control; 71 +/- 2 cm/s, p < 0.05), and the deceleration rate of the E wave velocity was more rapid in MI rats (MI; 22.0 +/- 2.6 m/s2 versus the control; 16.5 +/- 2.0 m/s2, p < 0.01). Atrial filling wave (A wave) velocity decreased, resulting in a marked increase in the ratio of E wave to A wave velocity (MI; 3.1 +/- 0.3 versus the control; 2.1 +/- 0.2, p < 0.01). In the adjacent noninfarcted myocardium, mRNA levels for alpha-skeletal actin, atrial natriuretic polypeptide (ANP), transforming growth factor-beta 1(TGF-beta 1), fibronectin, and collagen types I and III increased significantly. In the remote noninfarcted myocardium, mRNA levels for alpha-skeletal actin, ANP, and collagen types I and III increased, while mRNA levels for beta-myosin heavy chain, TGF-beta 1 and fibronectin did not change. We observed left ventricular dysfunction and different gene expression between adjacent noninfarcted myocardium and in the remote noninfarcted myocardium two days after MI. These findings suggest that cardiac gene expression after MI may be a compensation reaction for cardiac dysfunction induced by myocardial damage.

Animals↗
PubMed1998

Pearls in the management of submacular hematoma.

Subretinal hemorrhage (SRH), complicated by choroidal neovascularization such as age-related macular degeneration, often reduces central vision in middle-aged patients. Although the visual results of SRH removal by surgery seem to have improved recently, the efficacy has not yet been confirmed in a prospective, controlled fashion. Therefore, it cannot be stated with certainty that surgery for SRH is more beneficial than the natural course of the disease. However, we believe surgery is beneficial in selected patients. Herein, we describe our technique for the surgical removal of SRH. The development of safer, more effective techniques should further improve patient outcomes.

Fluorescein Angiography↗
PubMed1998

[Evaluation of patients with cerebral infarction using transesophageal echocardiography: atherosclerotic changes in the thoracic aorta and the branches of the aortic arch].

Atherosclerotic disease of the aortic arch is thought to be a potential source of cerebral emboli, but this disease in the branch of the aortic arch has not been extensively explored. This study assessed atherosclerotic lesions in the thoracic aorta and the branches of the aortic arch using transesophageal echocardiography in patients with cerebral infarction, and simultaneously searched for potential cardiac sources for emboli. Thrombi were detected in the left atrial appendage in nine of 54 patients with cerebral infarction and these patients were excluded. The remaining 45 patients with cerebral infarction (31 males and 14 females aged 68.5 +/- 7.4 years) and 35 normal subjects (21 males and 14 females aged 69.2 +/- 9.5 years) were evaluated. The thickness of the wall was measured in the branches of the aortic arch (brachiocephalic trunk, left common carotid artery and left subclavian artery) as well as the thoracic aorta (ascending aorta, aortic arch and descending aorta). Atherosclerotic lesions were defined as increased echogenicity of the intima (intimal thickening), calcification, protruded plaque, ulceration or plaque with cystic lesion. The thicknesses of the wall in the aortic arch (3.84 +/- 1.25 vs 2.71 +/- 1.33 mm, p < 0.01), left common carotid artery (2.67 +/- 1.10 vs 2.16 +/- 0.91 mm, p < 0.05) and the left subclavian artery (2.52 +/- 0.67 vs 2.15 +/- 0.88 mm, p < 0.05) were significantly greater in patients than in the normal subjects. The incidence of plaque or ulceration was significantly increased in patients with cerebral infarction compared with the normal subjects in the aortic arch (76% vs 43%, p < 0.05) and left common carotid artery (44% vs 17%, p < 0.05). Transesophageal echocardiography can detect possible sources of emboli in the branches of the aortic arch as well as the thoracic arch in patients with cerebral infarction.

Aged↗