Shelley Yang

Visual Avoidance in Xenopus Tadpoles Is Correlated With the Maturation of Visual Responses in the Optic Tectum

The optic tectum is central for transforming incoming visual input into orienting behavior. Yet it is not well understood how this behavior is organized early in development and how it relates to the response properties of the developing visual system. We designed a novel behavioral assay to study the development of visually guided behavior in Xenopus laevis tadpoles. We found that, during early development, visual avoidance-an innate, tectally mediated behavior-is tuned to a specific stimulus size and is sensitive to changes in contrast. Using in vivo recordings we found that developmental changes in the spatial tuning of visual avoidance are mirrored by changes in tectal receptive field sharpness and the temporal properties of subthreshold visual responses, whereas contrast sensitivity is affected by the gain of the visual response. We also show that long- and short-term perturbations of visual response properties predictably alter behavioral output. We conclude that our assay for visual avoidance is a useful functional measure of the developmental state of the tectal circuitry. We use this assay to show that the developing visual system is tuned to facilitate behavioral output and that the system can be modulated by neural activity, allowing it to adapt to environmental changes it encounters during development.

Antiproliferative and Apoptotic Effects of Indomethacin on Human Retinoblastoma Cell Line Y79 and the Involvement of ß-Catenin, Nuclear Factor-κB and Akt Signaling Pathways

Background: To determine in vitro if indomethacin inhibits proliferation and induces apoptosis in human retinoblastoma cell line Y79, and to explore possibly involved signaling pathways. Methods: The human retinoblastoma cell line Y79 was cultured with indomethacin at various concentrations (0, 25, 50, 100, 200 and 400 µmol/l). The effect of indomethacin on cell proliferation and apoptosis was examined by the Cell Counting Kit-8 and TUNEL test, respectively. The mRNA level of survivin, ß-catenin and Bcl-2 was detected by RT-PCR. The protein level of survivin was measured by ELISA. Western blot was used to analyze ß-catenin, nuclear factor (NF)-κB/p65, phosphorylated Akt (pAkt) and total Akt (tAkt) expression in cultured cells. Results: Indomethacin treatment inhibits proliferation (at concentrations from 25 to 400 µmol/l) and induces apoptosis (at concentrations from 100 to 400 µmol/l) of human retinoblastoma cell line Y79 in a dose-dependent manner. RT-PCR showed that the mRNA expression of Bcl-2 (F = 20.497; p < 0.001) and of ß-catenin (F = 14.835; p < 0.001) was significantly different among the treated groups. Survivin mRNA levels remained steady, but its protein levels decreased significantly as measured by ELISA (F = 67.633; p < 0.001). Western blot analysis showed a dose-dependent downregulation of ß-catenin (F = 37.411; p < 0.001), NF-κB/p65 (F = 16.302; p < 0.001) and of pAkt (F = 27.700; p < 0.001) after indomethacin treatment, while tAkt protein expression was steady among the groups. Conclusions: Treatment with indomethacin can potently suppress proliferation and induce apoptosis in the retinoblastoma Y79 cell line. Wnt/ß-catenin, NF-κB and Akt/PKB pathways might be implicated in the process.

Vitreous surgery for macular hole-related retinal detachment after phacoemulsification cataract extraction: 10-year retrospective review

PurposeTo evaluate the visual and anatomical results of surgery for macular hole-related retinal detachment (MHRD) after phacoemulsification cataract extraction.MethodsData for all patients who underwent surgery for MHRD after phacoemulsification cataract extraction from 1 December 1998 to 30 September 2008 in one hospital were evaluated. Patient characteristics, best-corrected visual acuity (VA) preoperatively and at last examination, surgical technique, anatomical success, and follow-up period were extracted and analysed statistically.ResultsA total of 13 625 eyes of 10 076 patients who had phacoemulsification cataract surgery were included. In the follow-up period, 10 cases of MHRD in nine patients were observed, of which seven eyes had high myopia. The mean axial length was 30.97±1.36 mm (29.19, 32.97) and mean myopia was−19.35±1.93 (−7.5,−3.5) dioptres. Overall anatomical success was achieved in 90% (9 out of 10 eyes). There was no statistically significant difference (P=0.240) between the logarithm of the MAR VA before the phacoemulsification cataract extraction and after MHRD surgical repair. VA increased in three eyes but decreased in the other seven after MHRD surgery.ConclusionsAs a primary procedure, vitreous surgery combined with other necessary adjunct procedures such as membrane peeling and retinal tamponade seems to be successful in achieving anatomical success. However, VA improvement is dependent on the type of macular lesion and not the surgical procedure.

Common Dermatologic Procedures

Dermatologists perform a wide variety of procedures on a daily basis. The skin biopsy is a fundamental technique that can be performed by all physicians who manage cutaneous conditions. Specimens should always be sent for pathologic evaluation, regardless of whether the sampled lesion appears benign. Postoperative care and education are critical for minimizing complications.

Clear lens phacoemulsification combined with vitrectomy to correct high myopia: four years of follow-up.

Purpose: To evaluate the outcome, intraoperative and postoperative complications of refractive lens exchange (RLE) by phacoemulsification with posterior chamber intraocular lens (IOL) implantation combined with simultaneous pars plana vitrectomy (PPV) in the management of high myopia. Methods: This prospective study consisted of 45 eyes of 26 patients with preoperative myopia greater than –12.5 dpt. Clear lens phacoemulsification with IOL implantation surgery was combined with PPV. Main outcome measures were best-corrected visual acuity (BCVA), stability of the spherical equivalent (SE) and complications at follow-up. Results: The combined procedure of clear lens phacoemulsification combined with PPV has a favorable outcome with acceptable SE predictability and improvement in BCVA. The postoperative BCVA was 0.67 ± 0.21 compared to 0.15 ± 0.10 preoperatively (p < 0.001). The mean postoperative SE was –1.6 ± 0.9 dpt, showing a significant difference when compared with a mean value of –20.0 ± 5.2 dpt before the operation (p < 0.001). During the follow-up, all IOLs were placed stably in the bag with no capsular tear occurring and only 1 case (2.2%) developed retinal detachment. Conclusion: RLE and implantation of an IOL combined with simultaneous PPV is a reasonable refractive surgery option for middle-aged patients with high myopia.

An atypical presentation of herpes simplex virus infection in Harlequin ichthyosis

We present an atypical presentation of herpes simplex virus infection in a patient with Harlequin ichthyosis, which we attribute to abnormal cornification.

Collagen Vascular Diseases

Autoimmune collagen vascular diseases, also referred to as autoimmune connective tissue disorders or rheumatic diseases, are a heterogeneous group of disorders caused by circulating autoantibodies that lead to inflammation of connective tissue throughout the body. Many present with dermatologic findings that may be diagnostic, but also have extracutaneous manifestations. This chapter will focus on rare autoimmune connective tissue diseases in children: Antiphospholipid Antibody Syndrome, Anetoderma, Atrophoderma of Pasini and Pierini, Degos Disease (Malignant Atrophic Papulosis), Dermatomyositis, Eosinophilic Fasciitis, Juvenile Idiopathic, Arthritis, Lupus Erythematosus, Localized Scleroderma/Morphea, Lichen Sclerosus, Mixed Connective Tissue Disease and Relapsing Polychondritis.

Multiple papules on the hands of a woman with common variable immunodeficiency

buccal mucosa, tympanic membranes, and auditory canals may also be involved. Nevus of Hori has the same features of nevus of Ota, but occurs bilaterally. Blue nevus usually presents as a well-defined blue-black papule or nodule. Q-switched (QS) lasers, including QS ruby laser, QS neodymium:yttrium-aluminum-garnet laser, and QS alexandrite laser are the primary treatment for ADM. These lasers work by destroying melanin. Application of tretinoin 0.1% aqueous gel and hydroquinone 5% ointment containing 7% lactic acid before laser treatment may remove overlying epidermal melanin, commonly found in patients with ADM, thereby allowing better penetration of the laser into the dermis. Pretreatment with tretinoin and hydroquinone has the further advantage of decreasing the incidence of postinflammatory hyperpigmentation, which usually occurs within weeks after QS laser treatment of ADM. Dermabrasion, although an effective treatment for ADM, is considered second-line treatment because it is invasive. Cryotherapy has had variable results and may cause scarring and hypopigmentation. Other treatment options, including electric cauterization, bleaching, chemical peels, and carbon dioxide laser, have been unsuccessful in treating ADM. For the series, the recommended choices are: 5, b; 6, d; 7, d; 8, c.