Immunohistochemical Findings of Lens Capsules Obtained from Dead Bag Syndrome Patients.

PURPOSE: To investigate the extracellular matrix and cellular components in lens capsules extracted from patients with dead bag syndrome (DBS) through immunohistochemistry. SETTING: Department of Ophthalmology, Wakayama Medical University School of Medicine and Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah. DESIGN: Immunohistochemical experimental study. METHODS: Nine capsular bag specimens from DBS cases, as well as 2 control specimens from late-postoperative in-the-bag intraocular lens dislocation cases related to previous vitrectomy, pseudoexfoliation, and blunt trauma were included. They were processed for histopathology; unstained sections were obtained from each one, and analyzed by immunohistochemistry targeting collagen type IV, laminin, vimentin, collagen type I and fibronectin. RESULTS: Immunohistochemistry in DBS showed lens capsule stained for basement membrane components. The outer part of the anterior capsule that was split from the inner part was more markedly stained for type IV collagen as compared with the posterior part. Faint staining for fibrous posterior capsular opacification (PCO) components, e. g., collagen type I and fibronectin, was detected in limited areas, but the major portion of the capsule was free from these components. Small spotty vimentin-positive materials, suggesting the presence of cell debris, was also detected in limited samples. CONCLUSION: Small amounts of fibrotic PCO components were detected in capsules extracted from patients with DBS, but their major parts were free from PCO components. Current findings suggest small amounts of lens epithelial cells were present after surgery and secreted fibrous components before undergoing cell death process.

Loss of TRPV4 Cation Channel Inhibition of Macrophage Infiltration and Neovascularization in a Mouse Cornea.

Corneal injury-associated inflammation could induce inward-growing neovascularization from the periphery of the tissue. Such neovascularization could cause stromal opacification and curvature disturbance, and both potentially impair visual function. In this study, we determined the effects of the loss of transient receptor potential vanilloid 4 (TRPV4) expression on the development of neovascularization in the corneal stroma in mice by producing a cauterization injury in the central area of the cornea. New vessels were immunohistochemically labeled with anti-TRPV4 antibodies. TRPV4 gene knockout suppressed the growth of such CD31-labeled neovascularization in association with the suppression of infiltration of macrophages and tissue messenger RNA expression of the vascular endothelial cell growth factor A level. Treatment of cultured vascular endothelial cells with supplementation of HC-067047 (0.1 µM, 1 µM, or 10 µM), a TRPV4 antagonist, attenuated the formation of a tube-like structure with sulforaphane (15 µM, for positive control) that modeled the new vessel formation. Therefore, the TRPV4 signal is involved in injury-induced macrophagic inflammation and neovascularization activity by vascular endothelial cells in a mouse corneal stroma. TRPV4 could be a therapeutic target to prevent unfavorable postinjury neovascularization in the cornea.

Delayed regression of laser-induced choroidal neovascularization in TNFα-null mice.

We investigated the effects of lacking TNFα on the development and regression of Argon-laser-induced choroidal neovascularization (CNV) in mice. We lasered ocular fundus for induction of CNV in both wild-type (WT) and TNFα-null (KO) mice. Fluorescence angiography was performed to examine the size of CNV lesions. Gene expression pattern of wound healing-related components was examined. The effects of exogenous TNFα on apoptosis of human retinal microvascular endothelial cells (HRMECs) and on the tube-like structure of the cells were investigated in vitro. The results showed that Argon-laser irradiation-induced CNV was significantly larger in KO mice than WT mice on Day 21, but not at other timepoints. Lacking TNFα increased neutrophil population in the lesion. The distribution of cleaved caspase3-labelled apoptotic cells was more frequently observed in the laser-irradiated tissue in a WT mouse as compared with a KO mouse. Exogenous TNFα induced apoptosis of HRMECs and accelerated regression of tube-like structure of HRMECs in cell culture. Taken together, TNFα gene knockout delays the regression of laser-induced CNV in mice. The mechanism underlying the phenotype might include the augmentation of neutrophil population in the treated tissue and attenuation of vascular endothelial cell apoptosis.

Candida guilliermondii-induced chorioretinitis in a patient with eating disorder.

Candidemia is a life-threatening fungal infection among patients undergoing long-term intravenous catheterization, hematopoietic stem cell transplantation, or immunosuppressive therapy, as well as patients with severe immunodeficiency or cancer. Endophthalmitis is a rare but severe form of ocular inflammation caused by infection of the intraocular cavity, which can lead to irreversible visual loss if not treated properly and promptly. The initial manifestation typically involves chorioretinitis, which requires early diagnosis and appropriate treatment. Candida guilliermondii is a non-Candida albicans yeast species; its frequency of detection in Japan has increased in recent years, and many drug-resistant and less-chorioretinitis-related strains are known. Here, we describe a 17-year-old girl with an eating disorder who exhibited chorioretinitis because of catheter-related bloodstream infection (CRBSI) caused by C. guilliermondii. The patient was hospitalized with severe weight loss, and she was presumed to develop candidemia because of immunosuppression during central parenteral nutrition therapy with a peripherally inserted central catheter. After onset of CRBSI, the catheter was immediately removed. Antifungal therapy was modified following fundus examination, fungal species confirmation, and drug sensitivity confirmation; thus, the patient recovered without long-term complications. To the best of our knowledge, this is the first report of C. guilliermondii-induced chorioretinitis in a patient with an eating disorder. Prolonged malnutrition and immunosuppression during nutritional therapy create a risk of candidemia in patients with eating disorders. After the onset of CRBSI, early administration and appropriate use of antifungal agents, with respect to specific ocular complications, are important for reduction of both mortality and ocular complications.

Utility and Validity of Intracoronary Administration of Nicorandil Alone for the Measurement of Fractional Flow Reserve in Patients With Intermediate Coronary Stenosis.

BACKGROUND: Intracoronary (IC) administration of nicorandil has been proposed as an alternative choice of hyperemic agent for fractional flow reserve (FFR) measurements. This study evaluated the utility and validity of IC nicorandil administration alone to induce maximal hyperemia.Methods and Results:Two-hundred-seven patients with coronary artery disease listed for coronary angiography with FFR were prospectively enrolled. FFR was measured after (1) IC administration of nicorandil 2 mg (ICNIC2 mg); (2) continuous intravenous (IV) adenosine triphosphatase (ATP) infusion at 150 µg/kg/min (IVATP150); (3) IV ATP infusion at 210 µg/kg/min (IVATP210); (4) IC administration of 0.5 mg nicorandil during IVATP150 (ICNIC0.5 mg+IVATP150); (5) IC administration of 1 mg nicorandil during IVATP150 (ICNIC1 mg+IVATP150); and (6) IC administration of 2 mg nicorandil during IVATP150 (ICNIC2 mg+IVATP150). The average FFR values and the rate of achieving maximum hyperemia after ICNIC2 mg, IVATP150, IVATP210, ICNIC0.5 mg+IVATP150, ICNIC1 mg+IVATP150, and ICNIC2 mg+IVATP150 were 0.85±0.08, 0.89±0.08, 0.85±0.09, 0.84±0.08, 0.83±0.08, 0.83±0.08 (P<0.01), and 92%, 54%, 91%, 96%, 99%, 99% (P<0.01), respectively. The incidence of systolic aortic pressure drop, chest discomfort, and transient atrioventricular block increased in a dose-dependent manner after IV ATP infusion, but almost no adverse effects were observed after ICNIC2 mg. CONCLUSIONS: ICNIC2 mg produced a more pronounced hyperemia than continuous IV ATP, and might be the preferred method for assessment of FFR.

Ect2 and MgcRacGAP regulate the activation and function of Cdc42 in mitosis.

Although Rho regulates cytokinesis, little was known about the functions in mitosis of Cdc42 and Rac. We recently suggested that Cdc42 works in metaphase by regulating bi-orient attachment of spindle microtubules to kinetochores. We now confirm the role of Cdc42 by RNA interference and identify the mechanisms for activation and down-regulation of Cdc42. Using a pull-down assay, we found that the level of GTP-Cdc42 elevates in metaphase, whereas the level of GTP-Rac does not change significantly in mitosis. Overexpression of dominant-negative mutants of Ect2 and MgcRacGAP, a Rho GTPase guanine nucleotide exchange factor and GTPase activating protein, respectively, or depletion of Ect2 by RNA interference suppresses this change of GTP-Cdc42 in mitosis. Depletion of Ect2 also impairs microtubule attachment to kinetochores and causes prometaphase delay and abnormal chromosomal segregation, as does depletion of Cdc42 or expression of the Ect2 and MgcRacGAP mutants. These results suggest that Ect2 and MgcRacGAP regulate the activation and function of Cdc42 in mitosis.

A new look at Rho GTPases in cell cycle: role in kinetochore-microtubule attachment.

Rho GTPases including Rho, Rac and Cdc42 are involved in cell morphogenesis by inducing specific types of actin cytoskeleton and alignment and stabilization of microtubules. Previous studies suggest that they also regulate cell cycle progression; Rho, Rac and Cdc42 regulate the G(1)-S progression and Rho controls cytokinesis. However, a role of Rho GTPases in nuclear division has not been definitely shown. We have recently found that Cdc42 and its downstream effector mDia3 are involved in bi-orientation and stabilization of spindle microtubules attachment to kinetochores and regulate chromosome alignment and segregation. Here, we discuss how this is coordinated with other events in mitosis, particularly, with the action of Rho in cytokinesis and how attachment of microtubules to kinetochores is achieved and stabilized. We also discuss redundancy of dc42 and Cdc42-related GTPase(s) and potential mechanisms of chromosome instability in cancer.