Szu-Yuan Lin

Chemokine receptor expression profiles in nasopharyngeal carcinoma and their association with metastasis and radiotherapy

Nasopharyngeal carcinoma (NPC) is an epithelial cancer that metastasizes predictably to cervical lymph nodes or distant organs. To assess whether the chemokine receptors of NPC cells play important roles in metastasis and are associated with radiotherapy history, the significance of various chemokine receptors (CCR1–10, CXCR1–6, XCR1, and CX3CR1) in NPC cell lines (TW01, TW04, HONE1, BM1, and AS1) and 52 NPC tumour biopsies from 48 patients with NPC was evaluated by mRNA and cytometric analyses, chemotaxis and actin polymerization assays, and immunohistochemical staining. Quantitative real‐time reverse transcription‐polymerase chain reaction revealed substantial expression of CCR7, CCR9, CXCR4, and CXCR6 mRNA in all the NPC cell lines. Of these, however, only CCR7, CXCR4, and CXCR6 were functional in NPC cells. Negative immunoreactivity for CCR7, CXCR4, and CXCR6 was demonstrated in almost all nasopharyngeal (NP) specimens from patients with primary NPC (n = 12) and in those with regional metastatic NPC (n = 15). However, expression of two or three of these chemokine receptors was demonstrated in NP specimens from patients with liver metastasis. Strong positivity was demonstrated for all three of these chemokine receptors in almost all of the regional and distant metastasis specimens. Significant differences in the expression of CCR7, CXCR4, and CXCR6 were found between primary tumours and metastases (p < 0.001, p < 0.001, and p < 0.002, respectively). This observation was further confirmed by laser capture microdissection of freshly frozen tumours from primary (n = 5) and metastatic (n = 8) NPC sites (p = 0.04, 0.03, and 0.03 for CCR7, CXCR4, and CXCR6, respectively). Finally, significant differences in CXCR4 expression were demonstrated between de novo and post‐radiotherapy groups (1/22 vs. 5/8; p < 0.003). It appears reasonable to conclude, therefore, that CCR7, CXCR4, and CXCR6 are expressed and active in human NPC metastases, while CXCR4 expression is associated with radiotherapy history. Copyright

Changes of Anterior Segment in Myopic Eyes: Analysis with Scheimpflug System

The relations of the cornea, anterior chamber depth (ACD), and angle structures to myopia have not been studied extensively. We analyzed each of these parameters using an anterior segment image processing technique that applies the Scheimpflug principle. A total of 117 young high myopic [≥-8.0 diopters (D)] patients and 32 low myopic (<- 3.0 D) subjects were studied. Each patient was analyzed for refractive status and axial length. The EAS-1000 (Nidek) was used to measure the parameters. The results showed no significant difference of central corneal thickness between the high myopic and low myopic eyes. The corneal radius slightly correlated with increasing axial length but did not correlate with refractive status. The corneal radius of the high myopic subjects become steeper than that of the low myopic eyes only among males. The ACD was slightly deeper in high myopic eyes than in low myopic eyes. The widths of four anterior chamber angles also did not correlate with increasing myopia, but the temporal side of the chamber angle was wider in high myopic eyes. These results suggested that there was only a slight change in the anterior segment in high myopic eyes.

Effects of lid suturing and trans-scleral cryotherapy on ocular growth in a piglet model.

Purpose. To study whether lid suturing can induce axial myopia and explore whether trans-scleral cryotherapy can affect ocular growth in piglets or not Methods. A total of fourteen 2- to 3-week-old piglets were studied. Three groups were included: lid suture, cryotherapy, and both lid suture/cryotherapy groups. The lid suturing group (N=6) was given lid suturing to produce visual deprivation. The cryotherapy group (N=4) received transcleral cryotherapy 360° to encircle anterior to the equator. Both treatment groups (N=4) received both cryotherapy and lid suturing. The cycloplegic refraction, corneal power, biometric axial length, and intraocular pressure (IOP) were measured before the experiments and 4 months later. Results. Mild axial myopia was induced in five lid-sutured eyes of the lid suturing group. The ocular refraction and eye size of cryotherapy eyes were not different from the control eyes in the cryotherapy group. More myopia was found in all four piglets that received both cryotherapy and lid suturing. Conclusions. Lid suturing can induce axial myopia; however, cryotherapy did not affect normal eye growth and did not prevent the development of lid suturing myopia in piglets.

Breakdown of the Blood-Aqueous Barrier Caused by Argon Laser Panretinal Photocoagulation in the Rabbit Retina

Purpose: To evaluate the blood-aqueous barrier function after argon laser panretinal photocoagulation on the normal rabbit retina using laser flare photometry. Methods: Ten Rex pigmented rabbits were selected and treated with scatter photocoagulation in the nonvascularized retina (400 lesions per eye, 0.1 second exposure, 200 μm spots, 120 mW power setting). Aqueous flare values were measured 1, 2, 3, 7, 14, 28, 42, and 56 days after treatment. Results: Significant disruption of the blood-aqueous barrier was seen 1 week after photocoagulation. The peak flare intensity value of the treated eyes occurred on day 1, gradually decreased during the first week, and became insignificant by day 14. Conclusion: The present results have indicated that the argon laser panretinal photocoagulation can produce a breakdown of the blood-aqueous barrier.

Unilateral Choroidal Osteoma with Subretinal Fluid – Treated with Laser Photocoagulation : A Case Report

Choroidal osteoma, a rare, and juxtapapillary tumor, generally occurs unilaterally or bilaterally in healthy young female patients. The tumor may affect vision by extending to the macula area, producing macula involved serous detachment, or inducing subretinal neovascularization. We report a 29-year-old female patient with unilateral choroidal osteoma. Visual acuity was 20/200 in the left eye. Fundus examinations of the left eye showed a well-defined, pale orange, and slightly elevated choroidal lesion. Serous detachment of the macula was also noted. After treating with laser photocoagulation on the tumor surface, the subretinal fluid subsided and the patient’s visual acuity improved. Laser photocoagulation may be effective in decreasing subretinal fluid in eyes affected by choroidal osteoma.

The Relationship Between the Size of Optic Disc Crescent and Myopic Maculopathy

Myopic maculopathy is one of the most severe complications of high myopia. The severity correlates with the increase of axial length, refractive error and age. Optic disc crescent formation was suggested to be an early sign of the degeneration of the posterior pole. Thus, evaluating the correlation between myopic maculopathy and the size of the disc crescent is needed. Analysis of 993 high myopic patients form the high myopic clinic at National Taiwan University hospital (NTUH)showed that the size of the disc crescenet was correlated with an increase in axial length and refractive error. The incidence of disc crescent greater than one disc diameter (DD) was also higher in groups with axial length longer than 29.0 mm, refractive error over -15.0 D and/or age older than 40 years. As well, 69.4% of patients with myopic maculopathy more severe than D1 had disc crescents larger than 1 DD; 78.5% of patients with myopic maculopathy more severe than D2 had disc crescents larger than 1 DD. If only the disc crescent larger than 1 DD was considered, 75.8% of the patients had D1 myopic maculopathy or more, and 56.4%of the patients had D2 myopic maculopathy or more. If both conditions with axial length over 29.0mm and disc crescent larger than 1 DD were considered together, then 86.5% of the patients had D1 myopic maculopathy or more. Further, if all of the conditions with axial length over 29.0 mm, subject’s age older than 40 years and disc crescent larger than 1 DD were considered together, 94.3% of the patients had D1 or more myopic maculopathy. Therefore, the size of the disc crescent could be one of the factors to predict the possibility of myopic maculopathy. (Tzu Chi Med J 1996; 8: 205-211)

Lens Dislocation as a Complication of Neodymium: YAG Laser Iridotomy

Purpose: To report a patient who suffered from lens dislocation after Neodymium: YAG laser iridotomy (LI). Methods: A case report. Results: A 61-year-old man suffered from sudden decrease of vision in his right eye one week after argon laser gonioplasty and Neodymium: YAG laser iridotomy. Examination of the anterior segment showed patent iridotomy inferiorly and a visible scar from gonioplasty inferotemporally. Fundus examination revealed lens dislocation into the vitreous body without obvious retinal damage. During the 5 years of follow-up, his condition was stable without other complications. Conclusions: Occult lens subluxation should be suspected in patients present as angle closure without any precipitating risk factors. Nd: YAG laser iridotomy could have contributed to further zonular rupture and lens dislocation due to direct zonulysis or a shock-wave effect.

Basic Fibroblast Growth Factor Levels Increase Following Retinal Laser Photocoagulation in the Rex Pigmented Rabbit Retina

Purpose: To determine the intraocular levels of basic fibroblast growth factor following retinal laser photocoagulation. Methods: Pigmented Rabbit eyes were treated with scatter laser photocoagulation of the nonvascularized retina (400 lesions treated per eye at 0.1 second exposure, 200μm spots, and 150 mw power setting). Animals were sacrificed at various times up to 14 days after the laser. Eyes were then removed, and samples of the vitreous and aqueous humor were collected. Basic fibroblast growth factor levels were measured using an immunoassay. Results: When compared with non-lasered control eyes, basic fibroblast growth factor levels in both vitreous and aqueous humor of treated eyes on day 3 were increased. The increase in the vitreous in treated eyes compared to control eyes was statistically significant (P＜0.25). Conclusion: Our results show that intraocular basic fibroblast growth factor levels show a statistically significant increase in the vitreous following retinal laser photocoagulation. This preliminary study suggests that basic fibroblast growth factor may be involved in the modulation of the balance of intraocular growth factors following retinal laser photocoagulation.

Integrin-Mediated Matrix Attachment and Vitreous Contraction of Cultured Human Retinal Pigment Epithelial Cells

Background: The pathogenesis of proliferative vitreoretinopathy (PVR) is not fully understood. Integrins, a group of cell surface extracellular matrix (ECM) receptors, are thought to play an active role. Integrin-mediated ECM adhesion and vitreous contraction of human retinal pigment epithelial (RPE) cells were investigated in this study. Methods: Indirect immunofluorescent stain and flow cytometry were used to demonstrate and quantify the expression of integrins on cultured human RPE cells. The functional expression of integrins on RPE cells was evaluated by cell adhesion assay and bovine vitreous contraction assay with specific monoclonal anti-integrin subunit antibodies. Results: Cultured human RPE cells expressed collagen, fibronectin, vitronectin, and laminin receptors on the cell membranes. RPE cells used these integrins to attach to ECM proteins, and the attachment was blocked by integrin-specific monoclonal antibodies. In the vitreous gel model, RPE cells showed divalent-cation dependent vitreous contraction via α2β1 and α3β1 intrgrins. Cytokines enhanced the integrin-mediated vitreous contraction. Conclusion: Human RPE cells express β1 family and α(subscript v)β3 integrins that mediated ECM attachment and vitreous contraction. These integrins on the RPE cells may play an important role in the pathogenesis of PVR.

Ocular Complications in High Myopia

High myopia is an ocular disease characterized by abnormal visual functions, caused by excessive axial elongation. Retinal detachment, myopic maculopathy, glaucoma, and cataract are four major complications can cause blindness. Peripheral retinal degeneration (lattice degeneration) and vitreal traction are factors involving in the production of retinal detachment. Higher retinal detachment rate was found of the axial length between 26.0 and 27.0 mm. Early myopic maculopathy was defined as fundus change with lacquer cracks, which are seen as yellow white lines of irregular caliber whose course across the posterior pole. Refractive error more than -15.OD,, axial length over 29.0mm, and age more than 45 years old are risk factors for the development of early myopic maculopathy. Variable degrees of optic disc changes are found during myopic progression such as tilting, which made the diagnosis of glaucoma become more difficulty. Periodic visual field and three dimensional disc examination are important for high myopic patients. Nuclear type of cataract is frequent found in middle age. of high myopic patient, which may make the fast progression of, myopia.