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Shizuo Mukai

Publications and source records attributed to Shizuo Mukai.

9 recordsLinked to original sources
PubMed2006

Predictors of visual outcome and choroidal neovascular membrane formation after traumatic choroidal rupture.

OBJECTIVE: To determine predictors of choroidal neovascularization (CNV) and visual outcome after traumatic choroidal rupture. METHODS: A retrospective review of patients with traumatic choroidal rupture diagnosed in the Retina Service, Massachusetts Eye and Ear Infirmary, Boston, between January 1993 and August 2001 was performed. Parametric and nonparametric statistical methods were used to evaluate visual prognosis, CNV, and retinal detachment after traumatic choroidal rupture. RESULTS: One hundred eleven cases were identified and reviewed. Visual acuity (VA) changes were recorded in all of the cases. Thirty-eight (34%) of the 111 patients recovered driving vision (VA > or =20/40). Rupture location was recorded in 107 cases. Recovery of driving vision was seen in 20 (59%) of 34 eyes with peripheral choroidal ruptures, 17 (22%) of 73 eyes with macular choroidal ruptures, 38 (38%) of 99 eyes without CNV, 1 (8%) of 12 eyes with CNV, 38 (40%) of 96 eyes without retinal detachment, and 1 (7%) of 15 eyes with retinal detachment. Older age and location of rupture within the arcades were positively associated with CNV formation (P = .04 and .03, respectively). Foveal location of rupture, multiple ruptures, and poor baseline VA were associated with failure to recover driving vision in univariate regression analyses. In multivariate analysis, rupture location and baseline VA were independently associated with visual outcome. Of 12 patients diagnosed with CNV, 5 were not treated, 4 were treated with argon laser photocoagulation, 1 was treated with surgery, 1 was treated with argon laser photocoagulation followed by surgery, and 1 was treated with verteporfin photodynamic therapy. CONCLUSIONS: Most patients with traumatic choroidal rupture do not achieve final VA of 20/40 or better. Poor visual outcome was most highly associated with a macular rupture and baseline VA of less than 20/40. The formation of CNV was most strongly associated with older age and macular choroidal rupture.

Adolescent↗
PubMed2006

Pars plana vitrectomy in eyes treated for retinoblastoma.

BACKGROUND: As conservative treatments for retinoblastoma become more prevalent, there will be a greater number of ocular complications developing in eyes that previously would have been enucleated. Pars plana vitrectomy (PPV) is needed to manage some of these complications. METHODS: The authors evaluated three consecutive cases of PPV in eyes that were successfully treated for retinoblastoma from the Retina Service of the Massachusetts Eye and Ear Infirmary (MEEI) performed between 1989 and 2004. A review of the literature to date regarding PPV after treatment for retinoblastoma was also performed. RESULTS: There was no tumor reactivation in the three cases at MEEI. Vision was maintained at light perception in one case, and there was improvement in vision from hand motions to 20/80 and 20/400 to 20/160 in two cases. Twelve of the 24 cases reviewed in the literature were found to have significant complications of recurrent tumor, need for enucleation, and/or systemic metastasis. CONCLUSION: PPV is associated with significant risks in eyes previously treated for retinoblastoma and should be reserved for monocular patients with no other alternative for retaining visual function. Areas that may influence outcome include different treatment modalities and length of time of documented tumor inactivity before PPV.

Adolescent↗
PubMed2005

A novel treatment for ocular tumors using membrane FasL vesicles to activate innate immunity and terminate immune privilege.

PURPOSE: Ocular immune privilege promotes tumor growth by hindering the development of innate and adaptive immunity. A prior study showed that ocular tumors expressing the membrane-only form of Fas ligand (FasL) terminate immune privilege, induce vigorous inflammation, undergo rejection, and induce systemic protective immunity. In these previous experiments the tumor cells used were genetically engineered to express membrane FasL. As an initial step toward developing an immunotherapy for intraocular tumors, the present study was conducted to examine whether injection of microvesicles expressing membrane FasL into ocular tumors (that are FasL negative) would have a similar effect. METHODS: Microvesicles expressing either no FasL or membrane-only Fas ligand were coinjected with L5178Y-R lymphoma cells into the anterior chambers (AC) of DBA/2 mice. RESULTS: Tumor cells coinjected with control vesicles grew progressively in the AC, and all mice died of metastatic disease by day 15. By contrast, a single injection of membrane FasL vesicles induced a potent inflammatory response characterized by GR1+ neutrophils and F4/80+ macrophages and significantly improved survival from 0% in untreated mice to 58% in mFasL-treated mice. Among the surviving mice, the ocular tumor was eliminated in 55%, and the mice exhibited systemic protection from a second tumor challenge. In the remaining 45%, the ocular tumor was not eliminated, but the mice were protected from liver metastases. CONCLUSIONS: Bioactive membrane FasL microvesicles coinjected with tumor cells induce a potent inflammatory response that terminates immune privilege, eliminates ocular tumors, and prevents metastatic disease.

Animals↗
PubMed2003

Retinopathy after percutaneous transluminal coronary angioplasty and stent insertion for acute myocardial infarction.

PURPOSE: To report microvascular retinopathy after percutaneous transluminal coronary angioplasty and stent insertion for acute myocardial infarction. DESIGN: Observational case series. METHODS: Retrospective review of seven patients with a retinal microangiopathy following coronary catheterization, angioplasty, and stent placement. RESULTS: All patients had bilateral cotton-wool spots in peripapillary distribution; four also had retinal hemorrhages in both eyes. None complained of visual symptoms. Lesions resolved spontaneously within several months in six patients. CONCLUSION: Although angioplasty and stent placement are less invasive than cardiac surgery, they appear to cause a retinopathy similar to postpump retinopathy.

Aged↗
PubMed2002

Unexpected sensitivity to radiation of fibroblasts from unaffected parents of children with hereditary retinoblastoma.

The response to ionizing radiation was examined in diploid skin fibroblasts derived from 5 patients with hereditary type retinoblastoma as well as their parents. Unexpected sensitivity to cell killing, as measured by clonogenic survival, as well as enhanced radiation-induced G(1) arrest were observed in at least 1 parental fibroblast strain in all 5 families. In all cases, parental strains were equally or more radiosensitive than the probands. The mutation of the retinoblastoma gene (RB) determined in 4 of 5 probands was either absent from the parental cells, as expected from the negative family histories, or identical, in 1 father who was a known carrier. In the fifth family, the family history was negative for retinoblastoma. We hypothesize that the increased parental cell sensitivity to radiation suggests the presence of an as yet unrecognized genetic event occurring in 1 or both parents of children with retinoblastoma. Whether it increases mutability of the RB locus or other loci or interacts with RB is conjectural.

Cell Survival↗
PubMedDate not supplied

Derepression of HMGA2 gene expression in retinoblastoma is associated with cell proliferation.

To assess whether retinoblastoma formation is associated with the expression of high mobility group (HMG) A2 protein, a transcription factor that is highly expressed during embryogenesis and completely repressed in normal adult tissues, we performed Northern and Western blots and RT-PCR analyses, and immunohistochemistry to test for HMGA2 expression. We used established retinoblastoma cell lines in tumors grown in nude mice and clinical retinoblastoma specimens, and contrasted these tumors with normal embryonic and adult retina. Adenoviral-mediated antisense experiments were conducted on the retinoblastoma cell lines to suppress HMGA2 expression and determine if cell proliferation is HMGA2-dependent. We also transfected a retinoblastoma cell line to identify cis-regulatory elements and transcription initiation sites on the HMGA2 gene promoter. HMGA2 gene expression was silenced in terminally differentiated retina of 6-wk-old mice, but it was detected in retina of a 13.5-d postcoitum embryo. Reactivation of HMGA2 gene expression was observed in the retinoblastoma cell lines Y79, WERI-Rb1, and TOTL-1, in tumors derived from some of these cells propagated in nude mice, and in a high frequency of retinoblastomas excised from human patients. This suggests that expression of HMGA2 gene in retinoblastoma cells involves a derepression process. By using an antisense approach to block HMGA2 expression, we observed a decrease in the number of proliferating retinoblastoma cells. As a 1st step toward understanding HMGA2 gene reactivation in retinoblastoma, we mapped the 2 transcription initiation sites and associated positive regulatory elements within the WERI-Rb1 cells. Our discovery of derepression of HMGA2 gene expression in retinoblastoma provides the 1st evidence that this protein might contribute to neoplastic transformation of retina cells.

Animals↗