Shinsuke Suemori

Brazilian Green Propolis Protects against Retinal Damage In Vitro and In Vivo

Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological (anticancer, antimicrobial and anti-inflammatory) effects. We investigated whether Brazilian green propolis exerts neuroprotective effects in the retina in vitro and/or in vivo. In vitro, retinal damage was induced by 24 h hydrogen peroxide (H2O2) exposure, and cell viability was measured by Hoechst 33342 and YO-PRO-1 staining or by a resazurin–reduction assay. Propolis inhibited the neurotoxicity and apoptosis induced in cultured retinal ganglion cells (RGC-5, a rat ganglion cell line transformed using E1A virus) by 24 h H2O2 exposure. Propolis also inhibited the neurotoxicity induced in RGC-5 cultures by staurosporine. Regarding the possible underlying mechanism, in pig retina homogenates propolis protected against oxidative stress (lipid peroxidation), as also did trolox (water-soluble vitamin E). In mice in vivo, propolis (100 mg kg−1; intraperitoneally administered four times) reduced the retinal damage (decrease in retinal ganglion cells and in thickness of inner plexiform layer) induced by intravitreal in vivo N-methyl-d-aspartate injection. These findings indicate that Brazilian green propolis has neuroprotective effects against retinal damage both in vitro and in vivo, and that a propolis-induced inhibition of oxidative stress may be partly responsible for these neuroprotective effects.

A Novel Calpain Inhibitor, ((1S)-1-((((1S)-1-Benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic Acid 5-Methoxy-3-oxapentyl Ester (SNJ-1945), Reduces Murine Retinal Cell Death In Vitro and In Vivo

We examined whether ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), a new orally available calpain inhibitor, might reduce retinal cell death in vivo and/or in vitro. Retinal cell damage was induced in vivo in mice by intravitreal injection of N-methyl-d-aspartate (NMDA), and SNJ-1945 was intraperitoneally or orally administered twice. NMDA-induced calpain activity (measured as the cleaved products of α-spectrin) and its substrate, p35 (a neuron-specific activator for cyclin-dependent kinase 5), in the retina were examined by immunoblotting. In RGC-5 (a rat retinal ganglion cell line) cell culture, cell damage was induced by a 4-h oxygen-glucose deprivation (OGD) treatment followed by an 18-h reoxygenation period. In mouse retinas, SNJ-1945 (30 or 100 mg/kg i.p., 100 or 200 mg/kg p.o.) significantly inhibited the cell loss in the ganglion cell layer (GCL) and the thinning of the inner plexiform layer induced by NMDA. Furthermore, the number of positive cells for terminal deoxynucleotidyl transferase dUTP nick-end labeling was significantly reduced in the GCL and the inner nuclear layer of retinas treated with SNJ-1945 compared with vehicle-treated retinas 24 h after NMDA injection. Levels of cleaved α-spectrin products increased and p35 decreased 6 h after NMDA injection or later, and their effects were attenuated by SNJ-1945. In vitro, SNJ-1945 (10 and 100 μM) inhibited the OGD stress-induced reduction in cell viability. In conclusion, SNJ-1945 may afford valuable neuroprotection against retinal diseases, because it was effective against retinal damage both in vitro and in vivo. Our results also indicate that calpain activation and subsequent p35 degradation may be involved in the mechanisms underlying retinal cell death.

Intraocular Penetration of Intravenous Micafungin in Inflamed Human Eyes

ABSTRACT Eight eyes of 7 patients with fungal disease received intravenous injections of 150 to 300 mg micafungin, and samples of blood, cornea, retina-choroid, aqueous humor, and vitreous humor were collected. The micafungin levels in all collected samples exceeded the MICs; however, the levels in the vitreous and aqueous humors were lower. Our findings suggest that intravenous micafungin should be given in combination with intravitreal antifungal agents after vitrectomy in severe cases of intraocular fungal diseases.

Intraocular Penetration of Micafungin in Patient with Candida albicans Endophthalmitis

PURPOSE To investigate the penetration of micafungin, a new class of echinocandin antifungal agent, into the aqueous humor and vitreous after an intravenous administration. METHODS Endogenous endophthalmitis caused by Candida albicans developed bilaterally in a 67-year-old man. Three hours before vitrectomy, the patient received an intravenous injection of 300 mg micafungin. Samples of aqueous and vitreous were collected during the vitrectomy approximately 60 min after the intravenous injection. The concentration of micafungin in both bodies was determined by high-performance liquid chromatography. RESULTS The concentration of micafungin was 25.36 μg/mL in the serum, 0.026 μg/mL in the aqueous, and 0.043 μg/mL in the vitreous. The micafungin minimum inhibitory concentration (MIC) against the C. albicans strain isolated from our patient was 0.03 μg/mL. Thus, the micafungin reached the MIC in the vitreous. CONCLUSION We suggest that intravenous micafungin should be considered in mild cases of endogenous fungal endophthalmitis, or be given in combination with other intravitreal antifungal agents with vitrectomy in more severe cases.

Case of endogenous endophthalmitis caused by Streptococcus equisimilis

We report a rare case of endogenous endophthalmitis caused by Streptococcus equisimilis. A 74-year-old woman with endocarditis developed endogenous endophthalmitis. The patient underwent emergency mitral valvuloplasty, and intravitreal and subconjunctival injections of vancomycin and meropenem. After the surgery, she was treated with topical antibiotics, ointment, intravenous gentamicin and intravenous penicillin G potassium. The causative organism was identified as S. equisimilis. S. equisimilis should be considered as a pathogen that can cause severe endogenous endophthalmitis.

Case of endogenous endophthalmitis caused by Klebsiella pneumoniae with magA and rmpA genes in an immunocompetent patient

We report a case of endogenous endophthalmitis caused by Klebsiella pneumoniae in an immunocompetent patient. A 73-year-old man with acute epididymitis who had no history of diabetes mellitus developed endogenous endophthalmitis. The patient underwent anterior vitrectomy and intracapsular cataract extraction with intravitreal injections of both vancomycin and ceftazidime. After the surgery, he was treated with topical and intravenous antibiotics; however, the left eye perforated and was enucleated. Culture from vitreous biopsy specimens grew as K. pneumoniae, which was positive for both magA and rmpA. K. pneumoniae should be considered as a pathogen that can cause severe endogenous endophthalmitis in patients with urinary tract infection. The severity of the disease may be related to the virulence genes.

Stickler Syndrome Type 1 Accompanied by Membranous Vitreous Anomaly in Two Japanese Sisters

ABSTRACT We report two cases of Stickler syndrome type 1 accompanied by a membranous vitreous anomaly in two Japanese sisters. A nine-year-old girl was referred to us for a rhegmatogeneous retinal detachment in her right eye. She had moderate myopia and a membranous vitreous anomaly in both eyes. She also had micrognathia and a saddle nose, leading to a diagnosis of Stickler syndrome type 1. The retinal detachment persisted even after scleral buckling surgery; however, the retina was reattached after 25-gauge microincision vitreous surgery 11 days later. Her seven-year-old sister had been diagnosed with Pierre Robin sequence due to micrognathia, cleft palate, and saddle nose. She was myopic by about −9.0 diopters with a membranous vitreous anomaly in both eyes and circumferential perivascular retinal degeneration in the right eye. Genetic analyses showed that both sisters and their mother carried the same mutation in the COL2A1 gene. The findings in these sisters indicate that retinal detachment is associated with Stickler syndrome type 1. Micro-incison vitreous surgery might be effective for rhegmatogeneous retinal detachment with high vitreous liquefaction.

Elderly onset vitreous opacities as the initial manifestation in hereditary transthyretin (ATTR Val30Met) carries

ABSTRACT Familial amyloid polyneuropathy (FAP) is a systemic disorder transmitted as an autosomal dominant trait and is characterized by deposits of protein fibrils in various organs leading to physiologic dysfunction. In cases with FAP in Japanese endemic foci, their signs and symptoms often develop before the age of 40 years. We report on two elderly patients (an 80-year-old woman and an 83-year-old man) with progressive vitreous opacities (VOs) as the initial manifestation of hereditary transthyretin (ATTR Val30Met) carries, who had no evidence of systemic involvement or family history of amyloidosis and lived in non-endemic areas. Therapeutic vitrectomy with extensive vitreous removal combined with cataract surgery was performed. Clinicians should consider the possibility of hereditary transthyretin carries in cases presenting with VOs of undetermined etiology to avoid misdiagnosis.

Apolipoprotein E2 and E3, but Not E4, Promote Retinal Pathologic Neovascularization

Purpose To determine the relationship between the different isoforms of apolipoprotein E (ApoE) and retinal neovascularization. Methods The concentrations of ApoE and VEGF in vitreous humor samples with either a macular hole (MH), or diabetic macular edema (DME), or proliferative diabetic retinopathy (PDR) with or without intravitreal injection of bevacizumab (IVB) were measured by ELISA. The effects of each isoform of ApoE on human retinal microvascular endothelial cells (HRMECs) in culture or on the retina of oxygen-induced retinopathy (OIR) mice were investigated. Results The concentrations of ApoE and VEGF were significantly higher in the vitreous humor of patients with PDR and DME than in patients with an MH. There was a significant positive correlation between the concentrations of ApoE and VEGF in vitreous humor of patients. In vitro assays showed that ApoE2 and ApoE3, but not ApoE4, promoted the VEGF-induced cell proliferation and migration. In vivo assays showed that intravitreal injections of ApoE2 and ApoE3 increased the number and area of nodes in the retina of OIR mice. Moreover, ApoE was expressed in the vascular endothelial cell in both normal and OIR retinas, but their expression levels were different at postnatal day (P) 12 and P17. Conclusions These results demonstrate that ApoE2 and ApoE3, but not ApoE4, have proangiogenic effects, and the increased expression of ApoE in the vitreous humor of patients with PDR and DME indicates that ApoE2 and ApoE3 are involved in the development of retinal neovascularization in eyes.

Aspergillus tubingenesis endophthalmitis after cataract surgery with implantation of preloaded intraocular lens.

Abstract An 88-year-old man underwent uneventful phacoemulsification and aspiration with an implantation of a preloaded acrylic intraocular lens. Six months later, he developed endophthalmitis with negative aqueous cultures, and the inflammation was refractory to conventional antibacterial therapies. He was treated successfully with vitrectomy and removal of the IOL and the entire lens capsule. A combination of intravitreal voriconazole and systemic micafungin were prescribed, and the inflammation was resolved. As best we know, this is the first case of Aspergillus tubingenesis endophthalmitis that followed the implantation of a preloaded intraocular lens.