Association between Moraxella keratitis and advanced glycation end products.

Diabetes mellitus is recognized as a major predisposing factor for Moraxella keratitis. However, how diabetes mellitus contributes to Moraxella keratitis remains unclear. In this study, we examined Moraxella keratitis; based on the findings, we investigated the impact of advanced glycation end products (AGEs) deposition in the cornea of individuals with diabetic mellitus on the adhesion of Moraxella isolates to the cornea. A retrospective analysis of 27 culture-proven cases of Moraxella keratitis at Ehime University Hospital (March 2006 to February 2022) was performed. Moraxella isolates were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Among the patients, 30.4% had diabetes mellitus and 22.2% had the predominant ocular condition of using steroid eye drops. The species identified were Moraxella nonliquefaciens in 59.3% and Moraxella lacunata in 40.7% of patients. To investigate the underlying mechanisms, we assessed the effects of M. nonliquefaciens adherence to simian virus 40-immortalized human corneal epithelial cells (HCECs) with or without AGEs. The results demonstrated the number of M. nonliquefaciens adhering to HCECs was significantly increased by adding AGEs compared with that in controls (p < 0.01). Furthermore, in the corneas of streptozotocin-induced diabetic C57BL/6 mice treated with or without pyridoxamine, an AGE inhibitor, the number of M. nonliquefaciens adhering to the corneas of diabetic mice was significantly reduced by pyridoxamine treatment (p < 0.05). In conclusion, the development of Moraxella keratitis may be significantly influenced by the deposition of AGEs on the corneal epithelium of patients with diabetes mellitus.

Clinical characteristics of lacrimal drainage pathway disease-associated keratopathy.

PURPOSE: To report the clinical characteristics of 13 cases of noninfectious corneal ulceration related to lacrimal drainage pathway disease. METHODS: Medical records of 13 patients with lacrimal drainage pathway disease-associated keratopathy who were examined at Ehime University Hospital between April 2007 and December 2021 were analyzed. RESULTS: The predisposing lacrimal drainage pathway diseases for corneal ulceration were chronic dacryocystitis in seven patients and lacrimal canaliculitis in six patients. The corneal ulcers were located at the peripheral cornea in 10 patients and the paracentral cornea in three patients. All patients indicated few cellular infiltrations of the ulcerated area at the slit-lamp examination. Corneal perforation was found in seven patients. The primary identified organisms were Streptococcus spp. in chronic dacryocystitis and Actinomycetes spp. in lacrimal canaliculitis. All patients showed rapid healing of the epithelial defects after treatment of the lacrimal drainage pathway disease. The mean time elapsed between treatment of the lacrimal drainage pathway disease and re-epithelialization of corneal ulcer was 14.5 ± 4.8 days. CONCLUSION: Lacrimal drainage pathway disease-associated keratopathy may be characterized by peripheral corneal ulcer with few cellular infiltrations, occasionally leading to corneal perforation. Treatment of the lacrimal drainage pathway disease could be the most effective treatment for lacrimal drainage pathway disease-associated keratopathy.

Temperature Measurement of Hot Airflow Using Ultra-Fine Thermo-Sensitive Fluorescent Wires.

In this paper, we propose a temperature measurement method that uses ultrafine fluorescent wires to reduce the wire diameter to a much lesser extent than a thermocouple. This is possible because its structure is simple and any material can be used for the wire. Hence, ultrafine wires with a Reynolds number of less than 1.0 can be selected. Ultra-fine wires less than 50 µm in diameter were set in the test volume. The wire surfaces were coated with fluorescent paint. The test volume was illuminated using an ultraviolet light-emitting diode. The paint emits very tiny, orange-colored fluorescent light with an intensity that changes with the temperature of the atmosphere. The experimental results showed that the heating/cooling layers were well visualized and the temperature field was well analyzed.

In vivo confocal microscopic images of atypical amiodarone-induced keratopathy in patient with epithelial basement membrane dystrophy.

A 73-year-old man presented with bilateral corneal opacities. Slit-lamp biomicroscopy showed vortex and oval-shaped opacities. In vivo confocal microscopy (IVCM) showed findings characteristic of amiodarone-induced keratopathy along with epithelial basement membrane dystrophy (EBMD). The IVCM findings indicated that the oval-shaped opacities can be present with amiodarone-induced keratopathy in patients with EBMD.

T cell-specific deletion of Pgam1 reveals a critical role for glycolysis in T cell responses.

Although the important roles of glycolysis in T cells have been demonstrated, the regulatory mechanism of glycolysis in activated T cells has not been fully elucidated. Furthermore, the influences of glycolytic failure on the T cell-dependent immune response in vivo remain unclear. We therefore assessed the role of glycolysis in the T cell-dependent immune response using T cell-specific Pgam1-deficient mice. Both CD8 and CD4 T cell-dependent immune responses were attenuated by Pgam1 deficiency. The helper T cell-dependent inflammation was ameliorated in Pgam1-deficient mice. Glycolysis augments the activation of mTOR complex 1 (mTORC1) and the T-cell receptor (TCR) signals. Glutamine acts as a metabolic hub in activated T cells, since the TCR-dependent increase in intracellular glutamine is required to augment glycolysis, increase mTORC1 activity and augment TCR signals. These findings suggest that mTORC1, glycolysis and glutamine affect each other and cooperate to induce T cell proliferation and differentiation.

Histone H3K27 Demethylase Negatively Controls the Memory Formation of Antigen-Stimulated CD8+ T Cells.

Although the methylation status of histone H3K27 plays a critical role in CD4+ T cell differentiation and its function, the role of Utx histone H3K27 demethylase in the CD8+ T cell-dependent immune response remains unclear. We therefore generated T cell-specific Utx flox/flox Cd4-Cre Tg (Utx KO) mice to determine the role of Utx in CD8+ T cells. Wild-type (WT) and Utx KO mice were infected with Listeria monocytogenes expressing OVA to analyze the immune response of Ag-specific CD8+ T cells. There was no significant difference in the number of Ag-specific CD8+ T cells upon primary infection between WT and Utx KO mice. However, Utx deficiency resulted in more Ag-specific CD8+ T cells upon secondary infection. Adoptive transfer of Utx KO CD8+ T cells resulted in a larger number of memory cells in the primary response than in WT. We observed a decreased gene expression of effector-associated transcription factors, including Prdm1 encoding Blimp1, in Utx KO CD8+ T cells. We confirmed that the trimethylation level of histone H3K27 in the Prdm1 gene loci in the Utx KO cells was higher than in the WT cells. The treatment of CD8+ T cells with Utx-cofactor α-ketoglutarate hampered the memory formation, whereas Utx inhibitor GSK-J4 enhanced the memory formation in WT CD8+ T cells. These data suggest that Utx negatively controls the memory formation of Ag-stimulated CD8+ T cells by epigenetically regulating the gene expression. Based on these findings, we identified a critical link between Utx and the differentiation of Ag-stimulated CD8+ T cells.

Reinforce the antitumor activity of CD8+ T cells via glutamine restriction.

The antitumor activity of activated CD8+ T cells in the tumor microenvironment seems to be limited due to their being metabolically unfit. This metabolic unfitness is closely associated with T-cell exhaustion and impairment of memory formation, which are barriers to successful antitumor adoptive immunotherapy. We therefore assessed the role of glutamine metabolism in the antitumor activity of CD8+ T cells using a tumor-inoculated mouse model. The adoptive transfer of tumor-specific CD8+ T cells cultured under glutamine-restricted (dGln) conditions or CD8+ T cells treated with specific inhibitors of glutamine metabolism efficiently eliminated tumors and led to better survival of tumor-inoculated mice than with cells cultured under control (Ctrl) conditions. The decreased expression of PD-1 and increased Ki67 positivity among tumor-infiltrating CD8+ T cells cultured under dGln conditions suggested that the inhibition of glutamine metabolism prevents CD8+ T-cell exhaustion in vivo. Furthermore, the transferred CD8+ T cells cultured under dGln conditions expanded more efficiently against secondary OVA stimulation than did CD8+ T cells under Ctrl conditions. We found that the expression of a pro-survival factor and memory T cell-related transcription factors was significantly higher in CD8+ T cells cultured under dGln conditions than in those cultured under Ctrl conditions. Given these findings, our study uncovered an important role of glutamine metabolism in the antitumor activity of CD8+ T cells. The novel adoptive transfer of tumor-specific CD8+ T cells cultured in glutamine-restricted conditions may be a promising approach to improve the efficacy of cell-based adoptive immunotherapy.

Characteristics of Infectious Keratitis in Old and Very Old Patients.

PURPOSE: The aim of this study was to analyze patient backgrounds, including activities of daily living (ADL) and living status, predisposing risk factors, causative agents, and severity with infectious keratitis in old (75 < 85 years of age) and very old (≥85 years of age) patients. METHODS: We retrospectively reviewed 54 old patients who were hospitalized for infectious keratitis. The focus occupancy ratio (FOR) was defined as the total focus area/entire cornea area. RESULTS: The mean patient age was 82.9 ± 5.6 years. There were 33 old and 21 very old patients. Dementia was found in 8 patients (14.8%), but the most common predisposing risk factor was post-keratoplasty (15 patients, 27.8%). However, 10 patients (18.5%) had unknown risk factors. In all, 16 patients (29.6%) had low ADL, including being bedridden or being unable to go outside without assistance, and 19 patients (35.2%) lived alone. Causative agents were detected in 31 patients (57.4%) and included bacteria in 22 patients and fungi in 9 patients. Seventeen patients (31.5%) had >25% focus size of the corneal area. The average FOR was 12.1% ± 14.1%, and the mean best-corrected visual acuity (BCVA) at the first and final visits was 1.88 ± 0.71 and 1.52 ± 1.03 logMAR, respectively. Multivariate analyses showed that age correlated with FOR and the final BCVA. CONCLUSIONS: Infectious keratitis in old and very old patients is likely to be severe due to low ADL and social environment. Ophthalmologists should take care to identify keratitis during its early stage in these patients.

Anterior Segment Optical Coherence Tomography of Patients With Late-Onset Tunnel Fungal Infections With Endophthalmitis After Cataract Surgery.

PURPOSE: To report the use of anterior segment optical coherence tomography for characterization of late-onset tunnel fungal infections with endophthalmitis after cataract surgery. METHODS: Case reports. RESULTS: A 77-year-old female (case 1) and a 76-year-old male (case 2) who received cataract surgery 15 and 1 year before their initial visits, respectively, were treated with topical steroids based on a diagnosis of uveitis, because they showed growing white lesions on the upper iris and beneath the cataract scleral wound. Irrigation of the anterior chambers and removal of the white lesions were performed in each case, and microbiological tests were positive for fungi (case 1, a positive culture of Fusarium sp.; case 2, a filamentous fungus present in a direct smear) in the white lesions. Both cases were diagnosed as late-onset fungal endophthalmitis after cataract surgery and were treated with topical and systemic antifungal agents. However, the white lesions reappeared, and the inflammation in the anterior chambers worsened. Anterior segment optical coherence tomography showed the spread of the white lesions into the scleral incisions from cataract surgery. Deroofing of the tunnel and sclerocorneal patch grafts were performed in both cases to treat the fungal tunnel infections. After these treatments, inflammation of both corneas and anterior chambers subsided. CONCLUSIONS: Anterior segment optical coherence tomography can be used to identify late-onset fungal tunnel infections with endophthalmitis after cataract surgery.

Development of an immunochromatographic assay kit using fluorescent silica nanoparticles for rapid diagnosis of Acanthamoeba keratitis.

We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoeba antibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection of Acanthamoeba and diagnosis of Acanthamoeba keratitis (AK). The sensitivity of the FICGA kit was evaluated using samples of Acanthamoeba trophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detecting Acanthamoeba trophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such as Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence of Acanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection of Acanthamoeba trophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection of Acanthamoeba and may be useful for the diagnosis of AK.

Necrotizing keratitis caused by acyclovir-resistant herpes simplex virus.

BACKGROUND: We report a case of necrotizing keratitis caused by acyclovir (ACV)-resistant herpes simplex virus (HSV) with a clinical appearance similar to a previous fungal keratitis infection. METHODS: Observational case report. RESULTS: Penetrating keratoplasty was performed in the left eye with a history of herpetic keratitis that resolved with periodic treatment with ACV ointment and a topical steroid. The left eye was painful and red with an abscess and corneal erosion in the peripheral donor cornea. Examination of the scraped corneal epithelium by light microscopy and culturing identified Candida albicans; polymerase chain reaction (PCR) was negative for human herpes viruses. After antifungal treatment, the ocular pain gradually decreased and the lesions slowly improved but recurred with a similar clinical appearance. A second light microscopy examination and cultures were negative for pathogens including C. albicans. PCR was positive for HSV-1 DNA; treatment with 3% topical ACV ointment was unsuccessful. A third examination showed only HSV-1 DNA. Despite antiviral ACV ointment, no clinical improvement occurred based on the HSV DNA copy numbers, which were the same before and after treatment, indicating a possible ACV-resistant strain. When topical trifluorothymidine was substituted for ACV, clinical improvement occurred and the HSV DNA copy numbers decreased. CONCLUSION: Necrotizing keratitis induced by ACV-resistant HSV occurred independently after fungal keratitis, with a similar clinical appearance in this case, making diagnosis and treatment difficult. Monitoring the HSV DNA load by real-time PCR could be useful for refractory cases even with atypical clinical appearances.

[Survey of the number of Acanthamoeba keratitis cases in Japan].

PURPOSE: To investigate the trend in the number of Acanthamoeba keratitis (AK) cases in Japan. METHOD: A survey was conducted in 48 university hospitals. Patients who were diagnosed with AK from January 2007 to December 2011 were enrolled. The trend in the number of cases and the type of contact lenses (CLs) that patients used were studied. RESULTS: A total of 524 patients was studied. The numbers of AK cases in each year, from 2007 to 2011, were 105, 152, 155, 65, and 47. The number dropped markedly after 2009. The percentage of conventional soft CLs and frequent replacement soft CL users that needed daily care such as rubbing-washing also dropped after 2008. CONCLUSION: The number of AK cases in Japan has been decreasing in recent years. The cause is uncertain, but one possibility is that information about proper CL care promulgated by ophthalmic societies in recent years is producing results.

Prospective clinical evaluation of 1.5% levofloxacin ophthalmic solution in ophthalmic perioperative disinfection.

PURPOSE: Gram-positive cocci and Propionibacterium acnes are widely reported agents of infectious postoperative endophthalmitis. This multicenter study was conducted to evaluate the eradication effectiveness and safety profile of levofloxacin 1.5% ophthalmic solution (LVFX 1.5%) for use in perioperative disinfection. METHODS: Patients who were scheduled for cataract surgery were enrolled. The perioperative regimen of LVFX 1.5% was administered 3 times daily as follows: preoperative 3 days; the day of surgery (in the morning, 1 h before surgery, and immediately after surgery); and postoperative 2 weeks. Conjunctival sac scrapings were collected 3 times in the observation period; before preoperative administration, before iodine eyewash on the day of surgery, and after completion of postoperative administration. Isolated and identified microbial strains were assessed for antibacterial susceptibility. RESULTS: One hundred patients were enrolled and data obtained from 96 patients (mean age, 72.7 ± 8.9 years). The preoperative eradication rate was 86.7% in total microbes. In the case of gram-positive cocci, the preoperative eradication rate was 100%, even though there were LVFX-registrant methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus, which had a high minimum inhibitory concentration against LVFX, such as 32 µg/mL. On the other hand, that of P. acnes was 78.3%. No acquired drug resistance was suspected in all strains. Adverse drug reactions occurred in 4.2% patients, and all were slight. CONCLUSIONS: For ophthalmic perioperative disinfection, the LVFX 1.5% ophthalmic solution showed a good safety profile, and critical eradication of gram-positive cocci, including the fluoroquinolone-resistant strains.

Spontaneous bleb formation in a presumed pellucid marginal corneal degeneration with acute hydrops.

PURPOSE: To report a case of spontaneous bleb formation in a presumed pellucid marginal corneal degeneration with acute hydrops. METHODS: A 51-year-old man reported sudden ocular pain with a lower conjunctival mass in his left eye. A clinical examination was performed to investigate this lesion. RESULTS: The intraocular pressure in the left eye was markedly lower compared with that in the opposite eye. Slit-lamp examination of the left eye showed a conjunctival mass inferior to the corneoscleral limbus adjacent to corneal epithelial and stromal edema without perforation. Corneal topography showed the typical bow tie appearance of corneal steepening rotated 120 degrees clockwise. The right eye was totally normal. Fourier-domain optical coherence tomography with a corneal anterior module adaptor clearly showed a break in Descemet membrane and a ruptured corneal stromal cleft under the conjunctiva near the corneal limbus that resulted in spontaneous bleb formation. The cornea gradually healed after bandage treatment; the spontaneous bleb became smaller and the corneal stromal cleft and edema regressed at 3 months with corneal scarring. The intraocular pressure in the left eye recovered to the same level as that in the opposite eye in association with the decreased bleb size. CONCLUSIONS: This case indicated that spontaneous bleb formation in a pellucid marginal corneal degeneration should be included in the differential diagnosis of a conjunctival mass of unknown origin.

Cytomegalovirus retinitis after multiple ocular surgeries in an immunocompetent patient.

PURPOSE: To describe the case of a 74-year-old man who developed cytomegalovirus (CMV) retinitis after multiple ocular surgeries. METHODS: Observational case report. RESULTS: A 74-year-old man who had a history of multiple ocular surgeries developed unilateral retinitis with whitening of the entire peripheral retina. A presumptive diagnosis of viral retinitis was considered, and polymerase chain reaction of the aqueous fluid was positive for CMV DNA. Laboratory examination revealed that the patient was completely immunocompetent. Moreover, the patient did not have any subtenon or intravitreal injection of triamcinolone acetonide (TA). The patient responded well to intravenous ganciclovir and oral valganciclovir. CONCLUSION: CMV retinitis can occur to immunocompetent patients without local immunosuppression with TA injection.