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1.
Rev Sci Instrum ; 95(7)2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-39051856

RESUMEN

For developing and characterizing a novel compact D-T neutron spectrometer based on a single-crystal chemical vapor deposition diamond stack for plasma diagnostics toward future D-T fusion reactors, the initial measurement was performed using the accelerator-based D-T neutron sources OKTAVIAN at Osaka University. This neutron spectrometer was designed for the detection of 3-17 MeV neutrons and operated in the proton recoil telescope configuration by installing a polyethylene converter in front of the diamond stack. The measured neutron energy spectra were obtained by summing the energy of the recoil protons deposited in the diamond stack after the coincidence of the recoil protons identified by the time coincidence analysis. The neutron energy peaks measured by the compact D-T neutron spectrometer were almost in agreement with those obtained by the Monte Carlo N-Particle transport (MCNP) simulation. The energy resolution of the compact D-T neutron spectrometer was emulated to be about 4%-5% in D-T neutron measurement. In future work, the design of the compact D-T neutron spectrometer would be optimized to measure the fusion neutron for plasma diagnostics.

2.
Appl Radiat Isot ; 209: 111299, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38613949

RESUMEN

Glass dosimeters are very useful and convenient detection elements in radiation dosimetry. In this study, this glass dosimeter was applied to a BNCT treatment field. Boron Neutron Capture Therapy (BNCT) is a next-generation radiation therapy that can selectively kill only cancer cells. In the BNCT treatment field, both neutrons and secondary gamma-rays are generated. In other words, it is a mixed radiation field of neutrons and gamma-rays. We thus proposed a novel method to measure only gamma-ray dose in the mixed field using two RPLGD (Radiophoto-luminescence Glass Dosimeter) and two sensitivity control filters in order to control the dose response of the filtered RPLGD to be proportional to the air kerma coefficients, even if the gamma-ray energy spectrum is unknown. As the filter material iron was selected, and it was finally confirmed that reproduction of the air kerma coefficients was excellent within an error of 5.3% in the entire energy range up to 10 MeV. In order to validate this method, irradiation experiments were carried out using standard gamma-ray sources. As the result, the measured doses were in acceptably good agreement with the theoretical calculation results by PHITS. In the irradiation experiment with a volume source in a nuclear fuel storage room, the measured dose rates showed larger compared with survey meter values. In conclusion, the results of the standard sources showed the feasibility of this method, however for the volume source the dependence of the gamma-ray incident angle on the dosimeter was found to be not neglected. In the next step, it will be necessary to design a thinner filter in order to suppress the effect of the incident angle.

3.
Appl Radiat Isot ; 199: 110897, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37352647

RESUMEN

Boron Neutron Capture Therapy (BNCT) is a cell-selective radiotherapy using a neutron capture reaction of 10B. In recent years, Accelerator Based Neutron Sources (ABNS) are under development instead of nuclear reactors for the next-generation neutron irradiation system for BNCT. However, ABNS as well as nuclear reactor usually generates unavoidable secondary gamma-rays by neutron-nuclear reactions such as capture reaction. In this research, we aimed to develop a separate measurement method of only gamma-rays in a mixed field of neutrons and gamma-rays using a fluorescent glass dosimeter (RPLGD), because most dosimeters have sensitivity to both radiation types. For this purpose, we proposed a lead filter method using two RPLGDs and lead filters. However, this method has a problem that the sensitivity to low energy gamma-rays (∼100 keV) is very small. In order to improve the sensitivity to low energy gamma-rays, we devised a method using a specially shaped lead filter. From theoretical calculations, we have shown that it was possible to estimate the air dose rate of the field where the gamma-ray energy spectrum shape was known for energies up to 10 MeV. In addition, we produced the specially shaped lead filter and experimentally confirmed the validity of the lead filter method using several gamma-ray standard sources and by measurements in a nuclear fuel storage room.

4.
Nat Commun ; 11(1): 4821, 2020 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-32973165

RESUMEN

Materials that possess nontrivial topology and magnetism is known to exhibit exotic quantum phenomena such as the quantum anomalous Hall effect. Here, we fabricate a novel magnetic topological heterostructure Mn4Bi2Te7/Bi2Te3 where multiple magnetic layers are inserted into the topmost quintuple layer of the original topological insulator Bi2Te3. A massive Dirac cone (DC) with a gap of 40-75 meV at 16 K is observed. By tracing the temperature evolution, this gap is shown to gradually decrease with increasing temperature and a blunt transition from a massive to a massless DC occurs around 200-250 K. Structural analysis shows that the samples also contain MnBi2Te4/Bi2Te3. Magnetic measurements show that there are two distinct Mn components in the system that corresponds to the two heterostructures; MnBi2Te4/Bi2Te3 is paramagnetic at 6 K while Mn4Bi2Te7/Bi2Te3 is ferromagnetic with a negative hysteresis (critical temperature  ~20 K). This novel heterostructure is potentially important for future device applications.

5.
Br J Oral Maxillofac Surg ; 57(9): 861-865, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31378404

RESUMEN

Osteo-odontokeratoprosthesis (OOKP) is a technique invented by Strampelli in 1963, in which the patient's own tooth root is used to support an optical cylinder. It uses an autologous tooth-bone-periodontal complex to mount an optical cylinder, which is stabilised by overlying autologous buccal mucosa. OOKP involves two, staged procedures done by ophthalmologists and oral surgeons, and the main contribution from the oral surgeon is during the first stage. To date we have done nine first-stage, and completed eight second-stage, OOKP operations in Japan with a mean follow-up of eight years and 11 months by modifying the original method of the oral surgery. All OOKP procedures were unilateral, and canines were selected as the donor teeth. Patients developed ocular blindness as a result of Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and chemical and thermal burns to the cornea and ocular surface. All eight patients who completed the second stage have been stable, and there have been no major perioperative or postoperative oral complications. The patients' visual acuities were stable with no serious complications. Here we report the technical details of the oral contribution to OOKP.


Asunto(s)
Proceso Alveolar , Enfermedades de la Córnea/cirugía , Implantación de Prótesis , Raíz del Diente/trasplante , Proceso Alveolar/trasplante , Córnea/cirugía , Femenino , Humanos , Japón , Masculino
6.
Clin Exp Immunol ; 191(1): 96-106, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28872665

RESUMEN

Cathelicidin peptide LL-37 plays an important role in the early host response against invading pathogens via its broad-spectrum anti-microbial activity. In this study, we investigated LL-37 expression in the inflamed mucosa of inflammatory bowel disease (IBD) patients. Furthermore, the regulatory mechanism of LL-37 induction was investigated in human colonic subepithelial myofibroblasts (SEMFs). LL-37 mRNA expression and protein secretion were analysed using real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Intracellular signalling pathways were analysed using immunoblotting and specific small interference RNA (siRNA). The expression of LL-37 mRNA was increased significantly in the inflamed mucosa of ulcerative colitis and Crohn's disease. The Toll-like receptor (TLR)-3 ligand, polyinosinic-polycytidylic acid (poly(I:C), induced LL-37 mRNA expression and stimulated LL-37 secretion in colonic SEMFs. The transfection of siRNAs specific for intracellular signalling proteins [Toll/IL-1R domain-containing adaptor-inducing interferon (IFN) (TRIF), tumour necrosis factor receptor-associated factor (TRAF)6, transforming growth factor ß-activated kinase (TAK)1] suppressed the poly(I:C)-induced LL-37 mRNA expression significantly. Poly(I:C)-induced phosphorylation of mitogen-activated protein kinases (MAPKs) and activated nuclear factor kappa B (NF-κB) and activating factor protein (AP)-1. siRNAs specific for NF-κB and c-Jun inhibited poly(I:C)-induced LL-37 mRNA expression. LL-37 suppressed lipopolysaccharide (LPS)-induced interleukin (IL)-6 and IL-8 expression significantly in colonic SEMFs. The expression of LL-37 was up-regulated in the inflamed mucosa of IBD patients. LL-37 was induced by TLR-3 stimulation and exhibited an anti-microbial effect via interaction with lipopolysaccharide (LPS).


Asunto(s)
Péptidos Catiónicos Antimicrobianos/genética , Regulación de la Expresión Génica , Enfermedades Inflamatorias del Intestino/genética , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Péptidos Catiónicos Antimicrobianos/metabolismo , Biomarcadores , Colon , Citocinas/metabolismo , Humanos , Inmunohistoquímica , Mediadores de Inflamación/metabolismo , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Péptidos y Proteínas de Señalización Intracelular , Quinasas Quinasa Quinasa PAM/metabolismo , Miofibroblastos/metabolismo , Poli I-C/inmunología , Transducción de Señal , Factor 6 Asociado a Receptor de TNF/metabolismo , Catelicidinas
7.
Br J Ophthalmol ; 93(1): 96-103, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18838407

RESUMEN

BACKGROUND/AIMS: To investigate the correlation between the clinical course and gene-expression pattern in murine oxygen-induced retinopathy (OIR), a commonly used model of retinopathy of prematurity (ROP). METHODS: OIR was induced in C57BL/6N mice by placing postnatal day 7 (P7) pups in 75% oxygen for 5 days. The clinical course of the OIR was evaluated on retinal flat-mounts after fluorescein isothiocyanate-conjugated dextran perfusion from P12 to P21. The expression values of 94 genes, selected by microarray analyses, were determined daily from P12 through P21 by RT-PCR with TaqMan low-density array (TLDA) and analysed by hierarchical clustering. RESULTS: TLDA cluster analyses showed a homology of gene-expression pattern between P12 and P13 and between P16 and P17. Many genes associated with inflammation were upregulated on P12 and P13 when the degree of both central avascular area and central vasoconstriction were maximal, and the upregulation of the genes continued to P21. At P16 and P17 when extraretinal neovascularisation became most noticeable, several genes associated with angiogenesis, for example, vascular endothelial growth factor-A and angiopoietin-2, were most upregulated. CONCLUSION: The gene-expression pattern was well correlated with the clinical appearance in murine OIR. These findings should contribute to the understanding of the pathological conditions in ROP.


Asunto(s)
Neovascularización de la Córnea/genética , Enfermedades de la Retina/genética , Animales , Animales Recién Nacidos , Modelos Animales de Enfermedad , Expresión Génica/genética , Perfilación de la Expresión Génica , Ratones , Ratones Endogámicos C57BL , Oxígeno/toxicidad , ARN Mensajero/metabolismo , Neovascularización Retiniana/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación hacia Arriba
8.
Br J Ophthalmol ; 92(11): 1450-5, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18621796

RESUMEN

AIM: The aim of the study was to evaluate the short-term efficacy of intravitreal injections of bevacizumab for severe retinopathy of prematurity (ROP). METHODS: A retrospective chart review was conducted of 23 consecutive eyes (stage 3, three eyes; 4A, 18 eyes; 4B, two eyes) of 14 patients with vascularly active ROP considered at high risk for progression or development of tractional retinal detachment despite conventional laser ablation therapy. Patients received an intravitreal injection of bevacizumab (0.5 mg), either as the initial treatment (15 eyes) or at the end of vitrectomy (eight eyes). RESULTS: After injection of bevacizumab as the initial treatment, reduced neovascular activity was seen on fluorescein angiography in 14 of 15 eyes. In three eyes, a tractional retinal detachment developed or progressed after bevacizumab injection. No other ocular or systemic adverse effects were identified. Vitrectomy was performed in 20 eyes and the retina was reattached after one surgery in 18 eyes. Multiple surgeries were necessary in two eyes, resulting in retinal reattachment. CONCLUSION: There results suggest that intravitreal injection of bevacizumab seems to be associated with reduced neovascularisation without apparent ocular or systemic adverse effects, and is thus beneficial for treating severe ROP that is refractory to conventional laser therapy.


Asunto(s)
Inhibidores de la Angiogénesis/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Desprendimiento de Retina/cirugía , Neovascularización Retiniana/tratamiento farmacológico , Retinopatía de la Prematuridad/tratamiento farmacológico , Vitrectomía/métodos , Anticuerpos Monoclonales Humanizados , Bevacizumab , Femenino , Angiografía con Fluoresceína/métodos , Humanos , Recién Nacido , Inyecciones/métodos , Masculino , Oftalmoscopía/métodos , Proyectos Piloto , Desprendimiento de Retina/prevención & control , Neovascularización Retiniana/complicaciones , Retinopatía de la Prematuridad/complicaciones , Retinopatía de la Prematuridad/cirugía , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Agudeza Visual/fisiología , Cuerpo Vítreo
9.
Br J Ophthalmol ; 91(2): 161-5, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16914470

RESUMEN

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.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Neovascularización Coroidal/tratamiento farmacológico , Miopía Degenerativa/complicaciones , Adulto , Anciano , Inhibidores de la Angiogénesis/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales Humanizados , Bevacizumab , Neovascularización Coroidal/etiología , Neovascularización Coroidal/patología , Neovascularización Coroidal/fisiopatología , Femenino , Estudios de Seguimiento , Fóvea Central/patología , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Agudeza Visual/efectos de los fármacos
10.
Transplant Proc ; 37(1): 46-8, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808542

RESUMEN

We examined the response of T lymphocytes activated with specific alloantigens following Fas-mediated apoptosis; using a mixed lymphocyte culture (MLC) system. Cells obtained from an MLC after 6 or 7 days of culture were incubated for are additional 24 hours in the presence or absence of the agonistic monoclonal antibody (MoAb), 7C11, or the antagonistic MoAb, ZB4. We assessed DNA fragmentation/specific cytotoxiy of the MoAb-treated cells. Cells harvested after 4 days of culture were sensitive to apoptosis induced by 7C11 with maximum DNA fragmentation observed on day 6. ZB4 slightly inhibited apoptosis of the cells compared with controls. The simultaneous addition of recombinant interleukin-2 (rIL-2) with the MoAbs significantly inhibited DNA fragmentation in control and ZB4-treated cells, but had little effect on the 7C11-treated cells. Control and ZB4-treated MLC cells showed cytotoxic activities against specific target cells, namely >10%. In contrast, the 7C11-treated cells showed <5% cytotoxicity. Although the addition of rIL-2 increased specific percentage cytotoxicity of control and ZB4-treated cells, it had little effect on the specific cytotoxic activity of the 7C11-treated MLC cells. These results suggest that specific cytotoxic T lymphocytes may be eliminated via apoptosis mediated by the Fas/Fas ligand system.


Asunto(s)
Isoantígenos/inmunología , Activación de Linfocitos/inmunología , Linfocitos T/inmunología , Receptor fas/inmunología , Adulto , Muerte Celular/inmunología , Humanos , Valores de Referencia , Linfocitos T/citología , Linfocitos T Citotóxicos/inmunología
11.
Am J Ophthalmol ; 132(6): 888-96, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11730654

RESUMEN

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.


Asunto(s)
Neovascularización Coroidal/cirugía , Fóvea Central/trasplante , Degeneración Macular/complicaciones , Trasplantes , Anciano , Anciano de 80 o más Años , Neovascularización Coroidal/etiología , Femenino , Angiografía con Fluoresceína , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Agudeza Visual
12.
Cancer ; 92(9): 2429-34, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11745300

RESUMEN

BACKGROUND: Transplantation of donor-derived malignancies during organ transplantation fortunately is very rare. Discontinuation of immunosuppressive medications under these circumstances has previously resulted in complete tumor rejection. Ectopic adrenocorticotropic hormone (ACTH) production may result in Cushing syndrome and is not an uncommon paraneoplastic feature of small cell carcinoma of the lung. Theoretically, in the organ transplantation setting, the resulting high cortisol levels could suppress a tumor-rejection immune response. However, to the authors' knowledge, no such clinical scenario has been described in the literature published to date. METHODS: A 25-year-old living related kidney transplant recipient presented with Cushing syndrome 32 months after transplantation. The donor had been diagnosed with small cell carcinoma of the lung 22 months earlier. On further evaluation, the kidney recipient was diagnosed with donor-derived small cell lung carcinoma of the transplanted kidney. She was found to have extensive disease involving the liver and retroperitoneum. Despite discontinuation of immunosuppressive medications, the disease progressed and cortisol levels remained elevated during 6 weeks of observation. RESULTS: The patient received six cycles of cisplatin and etoposide, which resulted in resolution of her hypercortisolemia and a complete remission of her donor-derived small cell carcinoma. At last follow-up, she was 12 months from completing her therapy and continued in complete remission. CONCLUSIONS: Donor-derived small cell carcinoma and ectopic ACTH production can occur in a patient after kidney transplantation.


Asunto(s)
Hormona Adrenocorticotrópica/biosíntesis , Carcinoma de Células Pequeñas/secundario , Neoplasias Renales/secundario , Trasplante de Riñón/efectos adversos , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Pequeñas/tratamiento farmacológico , Cisplatino/administración & dosificación , Síndrome de Cushing/etiología , Etopósido/administración & dosificación , Femenino , Humanos , Hidrocortisona/sangre , Inmunosupresores/administración & dosificación , Inmunosupresores/efectos adversos , Neoplasias Renales/tratamiento farmacológico , Donantes de Tejidos
13.
Am J Ophthalmol ; 132(4): 581-4, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11589888

RESUMEN

PURPOSE: To evaluate the peripheral visual field after foveal translocation with scleral imbrication or 360-degree retinotomy. METHODS: Retrospective, single-center, nonrandomized study. We calculated the rate of preservation of the peripheral visual field using Goldmann perimetry by dividing the width of the postoperative V-4 isopter by the preoperative width and expressing the result as a percentage. RESULTS: In nine eyes that underwent scleral imbrication, the rate of preservation was 100.0% superiorly, 102.6% superotemporally, 99.9% temporally, 97.9% inferotemporally, 96.9% inferiorly, 82.3% inferonasally, 93.7% nasally, and 87.3% superonasally. In 33 eyes that underwent 360-degree retinotomy, it was 89.1%, 87.0%, 81.9%, 78.1%, 86.6%, 90.0%, 89.9%, and 86.8%, respectively. CONCLUSION: After foveal translocation with scleral imbrication, the peripheral visual field was preserved except for slight narrowing nasally; 360-degree retinotomy resulted in preservation of the visual field, except for slight narrowing in all meridians.


Asunto(s)
Fóvea Central/trasplante , Campos Visuales/fisiología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Degeneración Macular/fisiopatología , Degeneración Macular/cirugía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Esclerótica/cirugía , Agudeza Visual , Pruebas del Campo Visual
15.
Am J Ophthalmol ; 132(3): 356-62, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11530048

RESUMEN

PURPOSE: Nuclear sclerosis develops frequently after successful pars plana vitrectomy. We evaluated changes in the degree of nuclear sclerosis after nonvitrectomizing vitreous surgery for idiopathic epimacular proliferation. METHODS: Forty-one consecutive patients (41 eyes) underwent removal of idiopathic epimacular proliferation by nonvitrectomizing vitreous surgery and were followed postoperatively for at least 12 months. Visual acuity, refractive error, slit-lamp biomicroscopy, and Scheimpflug photographs were assessed preoperatively and postoperatively to evaluate changes in the degree of lenticular opacification. Quantitative analysis of the nuclear sclerosis was performed by densitometry with Scheimpflug photographs performed on only the last 21 patients. We evaluated these measurements by comparing statistically the preoperative and postoperative difference between both eyes (operative eye minus nonoperative ocular data). RESULTS: There was no significant difference in the progression of nuclear sclerosis or degree of myopic shift between the operated and fellow eyes during postoperative follow-up (mean +/- SD, 22 +/- 8 months; median, 22 months; range, 12 to 48 months). The average preoperative and postoperative refractive errors in operated eyes were 0.0 +/- 2.4 diopters and 0.1 +/- 2.5 diopters, respectively; the average difference in the refractive errors between both eyes was -0.2 +/- 0.7 diopter preoperatively and -0.2 +/- 0.9 diopter postoperatively (P =.961, paired t test). The average preoperative and postoperative nuclear density values by Scheimpflug photography in 21 operated eyes were, respectively, 72 +/- 18 nuclear density units and 75 +/- 17 nuclear density units; the average difference in nuclear density values between both eyes was -1 +/- 4 nuclear density units preoperatively and 0 +/- 6 nuclear density units postoperatively (P =.631, paired t test). CONCLUSION: Progression of nuclear sclerotic cataract based on changes in refractive error and Scheimpflug photography was not observed after nonvitrectomizing vitreous surgery.


Asunto(s)
Catarata/patología , Núcleo del Cristalino/patología , Vitrectomía/efectos adversos , Anciano , Catarata/etiología , Catarata/fisiopatología , Membrana Epirretinal/cirugía , Femenino , Humanos , Núcleo del Cristalino/fisiopatología , Masculino , Persona de Mediana Edad , Miopía/fisiopatología , Fotograbar , Esclerosis , Agudeza Visual
16.
Graefes Arch Clin Exp Ophthalmol ; 239(5): 382-6, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11482343

RESUMEN

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.


Asunto(s)
Astigmatismo/diagnóstico , Córnea/patología , Topografía de la Córnea , Complicaciones Posoperatorias/diagnóstico , Esclerótica/cirugía , Animales , Astigmatismo/etiología , Enucleación del Ojo , Fóvea Central/trasplante , Curvatura de la Esclerótica , Porcinos
17.
Jpn J Ophthalmol ; 45(2): 199-201, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11313055

RESUMEN

PURPOSE: Viewing the fundus at higher magnification during vitrectomy makes surgical procedures much safer; however, the scope of magnification of the peripheral fundus has been limited. For better visualization of the periphery of the fundus, we have developed two new contact lenses called magnifying prismatic lenses. METHODS: The magnifying 15 degrees and 30 degrees prismatic lenses are made of a glass with a high index of refraction (n = 1.883). The lenses have a convex upper surface to provide a magnified view of the peripheral fundus. RESULTS: These magnifying 15 degrees and 30 degrees prismatic lenses provide an approximately 2x magnified view of the peripheral fundus. They also provide a more extensive view of the peripheral fundus than a regular (plano-concave) prismatic lens when the eye is tilted. CONCLUSION: The magnifying prismatic lenses are useful for viewing into the peripheral fundus with higher magnification.


Asunto(s)
Lentes , Vitrectomía , Fondo de Ojo , Humanos , Óptica y Fotónica
18.
Am J Ophthalmol ; 131(4): 481-8, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11292412

RESUMEN

PURPOSE: To determine whether intravitreal irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus (Alcon Laboratory, Fort Worth, Texas) solution alters the adhesiveness between the retinal pigment epithelium and the retina of rabbits. METHODS: Thirty-four eyes of 34 Dutch pigmented rabbits underwent lensectomy and vitrectomy. Subsequently, the vitreous cavity of 24 eyes was irrigated with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 10 or 20 minutes. The other 10 eyes were irrigated with BSS Plus solution for 20 minutes as controls. To determine the adhesiveness between the retinal pigment epithelium and retina, a retinal detachment was produced in 12 of the 34 eyes. The apical surface of the retinal pigment epithelium and the photoreceptor outer segments were examined by scanning electron microscopy. Retinal physiology was assessed by electroretinography and retinal morphology by light microscopy. RESULTS: After retinal detachment was produced, the number of cone sheaths on the apical surface of the retinal pigment epithelium after irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes (33 +/- 15, mean +/- SD) was significantly less than the number of cone sheaths on the apical surface of the retinal pigment epithelium of eyes after irrigation with BSS Plus solution for 20 minutes (120 +/- 50) or the number of cone sheaths on the apical surface of the retinal pigment epithelium of eyes after 10 minutes of irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution (115 +/- 49; P =.02). The b-wave amplitudes in the eyes irrigated with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes were depressed compared with the b-waves in eyes irrigated with BSS Plus solution for 20 minutes on the first postoperative day (P =.03). After the third postoperative day, there was no significant difference in the b-waves (P >.06). Light microscopy demonstrated no morphologic abnormalities after the use of both solutions. CONCLUSIONS: Intravitreal irrigation with Ca(2+)-free and Mg(2+)-free BSS Plus solution for 20 minutes altered the adhesion between the retinal pigment epithelium microvilli and retinal outer segments and made the creation of retinal detachment less traumatic. These results suggest that Ca(2+)-free and Mg(2+)-free BSS Plus solution may be of clinical value for the creation of an intentional retinal detachment for foveal translocation surgery.


Asunto(s)
Bicarbonatos/farmacología , Calcio/química , Glutatión/farmacología , Magnesio/química , Epitelio Pigmentado Ocular/efectos de los fármacos , Retina/efectos de los fármacos , Animales , Bicarbonatos/química , Adhesión Celular/efectos de los fármacos , Combinación de Medicamentos , Electrorretinografía , Glutatión/química , Cristalino/cirugía , Microscopía Electrónica de Rastreo , Soluciones Oftálmicas , Epitelio Pigmentado Ocular/ultraestructura , Conejos , Retina/fisiología , Retina/ultraestructura , Desprendimiento de Retina/inducido químicamente , Desprendimiento de Retina/patología , Vitrectomía
19.
Am J Ophthalmol ; 131(3): 388-90, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11239881

RESUMEN

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.


Asunto(s)
Colorantes , Membrana Epirretinal/cirugía , Verde de Indocianina , Miopía/complicaciones , Desprendimiento de Retina/cirugía , Membrana Basal/ultraestructura , Membrana Epirretinal/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Desprendimiento de Retina/etiología , Perforaciones de la Retina/complicaciones , Vitrectomía
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