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Biomedical subjects

Kei Shinoda

Publications and source records attributed to Kei Shinoda.

47 records · Page 3Linked to original sources
PubMed2004

[Diagnostic value of interleukin-10 and interleukin-6 in the vitreous of intraocular malignant lymphoma patients].

OBJECTIVE: Recent data suggest that the concentration of interleukin-10 (IL-10) is higher than that of interleukin-6 (IL-6) in the vitreous of eyes of patients with non-Hodgkin's lymphoma. In this study, we evaluated the utility of measuring intravitreal IL-10 and IL-6 concentrations in the diagnosis of intraocular lymphoma. METHODS: Specimens of undiluted vitreous were collected at the time of pars plana vitrectomy and IL-10 and IL-6 concentrations were determined. Vitreous specimens were obtained from 5 patients with suspected intraocular lymphoma and 10 patients with uveitis presumed to be unrelated to a neoplasm. RESULTS: In all 5 patients eventually diagnosed with intraocular lymphoma, the vitreous IL-10 concentration ranged from 3,040 to 11,200 pg/ml, and was higher than the vitreous IL-6 concentration in all cases. In 9 of the 10 patients with uveitis, the vitreous IL-10 concentrations ranged from less than 2 to 97 pg/ml, with an IL-10/IL-6 ratio of less than 0.11. However, in the remaining case diagnosed as uveitis of unknown etiology, the vitreous IL-10/IL-6 ratio was greater than 1. CONCLUSION: Our data suggest that the measurement of vitreous IL-10 concentrations would aid in the diagnosis of intraocular lymphoma.

Adolescent↗
PubMed2003

An in vivo doxycycline-controlled expression system for functional studies of the retina.

PURPOSE: Transgenic mice were developed that express tetracycline-controlled transactivator 1 (tTA1) specifically in photoreceptor cells. In these mice the transcription of the gene of interest can be easily inactivated in the retina in a short time frame. METHODS: A construct was prepared containing tTA1 under control of the murine rhodopsin regulatory region. This construct was used for the generation of transgenic mice. In situ hybridization was performed to study the distribution of the transactivator in the retina. The activity of the transactivator was analyzed by mating the lines with a luciferase reporter transgenic mouse. tTA1 activity and doxycycline's ability to block it were analyzed by luciferase assay. The effects of tTA1 on the retina were assessed by histology and electrophysiology. RESULTS: Two transgenic lines were developed that specifically express tTA1 in photoreceptor cells. The time course of transgene expression replicated transcription of endogenous rhodopsin. tTA1 was not toxic to the retina. Transactivator activity was blocked readily by doxycycline. CONCLUSIONS: An expression system for photoreceptor cells was generated to drive transcription in a cell-specific and time-controllable manner. This system is suitable for the study of factors involved in retinal biology and of mutant forms of genes involved in retinal diseases.

Animals↗
PubMed2002

In situ confirmation of retinal blood flow improvement after carotid endarterectomy in a patient with ocular ischemic syndrome.

PURPOSE: To report a patient with ocular ischemic syndrome due to an internal carotid artery stenosis in whom we confirmed improved retinal blood flow noninvasively after carotid endarterectomy. DESIGN: Observational case report. METHODS: Retinal flowmetry. RESULTS: In a 72-year-old hypertensive man with a transient ischemic attack including dysgraphia, carotid angiography revealed approximately 90% stenosis of the left internal carotid artery. Standard carotid endarterectomy was performed. Postoperatively, good patency of the left internal carotid artery was confirmed by magnetic resonance angiography. We measured tissue blood flow in the fundus of each eye using a Heidelberg retina flowmeter before and after endarterectomy. Preoperative measurements showed reduction of blood flow in the left fundus, while values 3 months after surgery indicated a significant improvement of blood flow (P <.05, one-factor analysis of variance [ANOVA]). CONCLUSIONS: Retinal flowmetry can noninvasively detect differences in retinal blood flow between eyes in a patient with unilateral internal carotid artery stenosis and also assess the improvement of retinal blood flow after carotid endarterectomy.

Aged↗
PubMed2002

ON-pathway disturbance in two siblings.

PURPOSE: To present two clinical cases diagnosed with predominant cone dystrophy and demonstrating early disturbance in the on-centre bipolar cells (ON-pathway). METHODS: Electrophysiological findings are presented in two siblings with predominant cone dystrophy. The subjects showed no remarkable ophthalmoscopic or fluorescein angiographic retinal changes, but demonstrated progressive visual disturbance during their 20s. RESULTS: The electroretinograms (ERGs) showed reduced dark-adapted responses but the positive component of the photopic ERG was absent. Response to 30 Hz flicker was severely reduced. Electroretinograms elicited by long-duration stimuli showed a loss of the b-wave, and the off-response was slightly reduced. In both patients, multifocal ERGs (m-ERGs) were more reduced within the central 10 degrees, where the ON-pathway is normally a major contributor. CONCLUSION: We conclude that these patients may be affected by an abnormality of the synapses of the cone receptors and that their decrease in vision might, at least initially, be due to selective ON-pathway dysfunction.

Adult↗
PubMed2002

[Two cases of retinal detachment following laser in Situ keratomileusis repaired by scleral buckling surgery].

BACKGROUND: As laser in situ keratomileusis (LASIK) becomes the treatment of choice in the field of refractive surgery, postoperative rhegmatogenous retinal detachment has also begun to occur. However, since it has not been reported yet here in Japan, we report two cases of retinal detachment following LASIK with suggestions based on our experience. CASES: A 34-year-old male(Case 1) and a 26-year-old male(Case 2) suffered from retinal detachment one month and eight months after LASIK, respectively. Contributing retinal breaks were a horseshoe tear in Case 1 and atrophic holes in the lattice degeneration in Case 2. Each patient underwent partial scleral buckling with no intraoperative complication, resulting in successful retinal reattachment. Postoperatively, myopic changes developed and persisted one month in Case 1 and several months in Case 2. CONCLUSIONS: Great attention should be paid to the possibility of postoperative myopia after a repair of retinal detachment following LASIK. Thus, we stress the necessity of close cooperation between LASIK surgeons and vitreoretinal surgeons to settle the matter.

Adult↗
PubMed2002

[The correlation between retinal circulation and function in branch retinal artery occlusion].

PURPOSE: To investigate retinal circulation and function in eyes with branch retinal artery occlusion(BRAO) using a scanning laser Doppler flow-meter (SLDF) and multifocal electroretinogram (mERG). METHODS: In juxtapapillary and paramacular areas close to the occluded artery of the affected eye and the corresponding area of the fellow eye, the mean flow measured by SLDF, indicating microcirculation, and the p-wave amplitude in the response of mERG, indicating retinal function, were determined in three patients with BRAO at the period of reperfusion. The ratios of the affected eye to fellow eye(a/f ratio) were calculated, and the ratios of the mean flow (Fa/f) were compared with those of the p-wave amplitude(Pa/f). RESULTS: In the juxtapapillary area, both Fa/f and Pa/f decreased consistently, but in the paramacular area, Pa/f were lower than Fa/f in all cases. CONCLUSIONS: Functional recovery is likely to be later in the paramacular area than in the juxtapapillary area in the course of recovery of retinal circulation.

Adult↗
PubMedDate not supplied

Retinal blood flow in the macular area before and after scleral buckling procedures for rhegmatogenous retinal detachment without macular involvement.

PURPOSE: To investigate retinal microcirculation changes in patients with rhegmatogenous retinal detachment (RRD). METHODS: The tissue blood flow in the macular area was measured in 28 patients with RRD without macular involvement by scanning laser Doppler flowmetry before and after scleral buckling procedures. The mean blood flow (MBF) was calculated by the automatic full-field analysis program. The MBF ratios of the affected eye to the fellow eye (a/f ratio) in patients were compared with those of the right eye to the left eye (R/L ratio) in the control subjects. RESULTS: The mean preoperative a/f ratio in the patients (0.81 +/- 0.11) was lower than the mean R/L ratio in the control subjects (1.02 +/- 0.11, P < 0.0001) and correlated with the extent of RRD (P < 0.05). The mean a/f ratio tended to decrease 2 weeks after surgery (0.72 +/- 0.09) and recovered to an almost normal level after 1 month (0.96 +/- 0.09). The blood-flow change was not influenced by the type of buckling. CONCLUSIONS: The retinal microcirculation in the macular area was disturbed in RRD patients without macular involvement. It correlated with the extent of the RRD, and subsided 1 month after successful scleral buckling procedures.

Adolescent↗
PubMedDate not supplied

Effect of topical unoprostone isopropyl on optic nerve head circulation in controls and in normal-tension glaucoma patients.

PURPOSE: To evaluate the effect of unoprostone isopropyl on microcirculation in the optic nerve head (ONH) of controls and patients with normal-tension glaucoma (NTG). METHODS: Thirty healthy volunteers were randomly placed in a placebo group or a control group. For ten NTG patients, one eye was selected to receive the placebo drops and the contralateral eye received the unoprostone in a masked fashion. In both studies, the intraocular pressure (IOP) and the parameters of the blood hemodynamics of the ONH were obtained before and at 1 and 2 h after the instillation. Blood flow measurements were made with a scanning laser Doppler flowmeter. RESULTS: In both control subjects and NTG patients, the changes in the IOPs after the instillation of either unoprostone or the placebo were not significant because almost all of the NTG patients had IOPs lower than 15 mmHg. Although the hemodynamic parameters were not significantly changed in the placebo-treated eyes of the controls, the eyes of the controls treated with unoprostone had mean blood velocity and flow values that were significantly higher than the baseline values 1 and 2 h after instillation (P < 0.01). The velocity values of the controls treated with unoprostone were significantly higher than in those controls receiving the placebo at 2 h postinstillation (P = 0.027). The values for the three circulation parameters (volume, velocity, flow) were significantly higher than the baseline values after instillation in the eyes of the NTG patients treated with unoprostone (P < 0.05). In contrast, none of these parameters was significantly different from the baseline in the eyes of NTG patients treated with placebo. CONCLUSIONS: These results showed that unoprostone significantly increased microcirculation in the ONH in control subjects and in NTG patients without reducing the IOP significantly.

Administration, Topical↗