Elucidating the molecular basis of PPCD: Effects of decreased ZEB1 expression on corneal endothelial cell function.

PURPOSE: To investigate the functional role that the zinc e-box binding homeobox 1 (ZEB1) gene, which underlies the genetic basis of posterior polymorphous corneal dystrophy 3 (PPCD3), plays in corneal endothelial cell proliferation, apoptosis, migration, and barrier function. METHODS: A human corneal endothelial cell line (HCEnC-21T) was transfected with siRNA targeting ZEB1 mRNA. Cell proliferation, apoptosis, migration, and barrier assays were performed: Cell proliferation was assessed with cell counting using a hemocytometer; cell apoptosis, induced by either ultraviolet C (UVC) radiation or doxorubicin treatment, was quantified by measuring cleaved caspase 3 (cCASP3) protein levels; and cell migration and barrier function were monitored with electric cell-substrate impedance sensing (ECIS). RESULTS: ZEB1 knockdown in HCEnC-21T cells transfected with siRNA targeting ZEB1 did not result in a significant difference in cell proliferation when compared with control. Although knockdown of ZEB1 in HCEnC-21T cells sensitized the cells to UV-induced apoptosis, ZEB1 knockdown did not alter the cells' susceptibility to doxorubicin-induced apoptosis, as measured with cCASP3 protein levels, compared with controls. Similarly, no difference was observed in cell migration following ZEB1 knockdown. However, cell barrier function increased significantly following ZEB1 knockdown. CONCLUSIONS: The corneal endothelium in PPCD3 is characterized by morphologic, anatomic, and molecular features that are more consistent with an epithelial-like rather than an endothelial-like phenotype. Although these characteristics have been well documented, we demonstrate for the first time that susceptibility to UV-induced apoptosis and cell barrier function are significantly altered in the setting of reduced ZEB1. The significance of an altered cellular response to apoptotic stimuli and increased cell barrier function in the pathobiology of PPCD remains to be fully elucidated.

Vortex Pattern of Corneal Deposits in Granular Corneal Dystrophy Associated With the p.(Arg555Trp) Mutation in TGFBI.

PURPOSE: To describe 2 unrelated families with multiple members demonstrating a less commonly recognized vortex pattern of corneal deposits confirmed to be granular corneal dystrophy type 1 (GCD1) after identification of the p.(Arg555Trp) mutation in the transforming growth factor ß-induced gene (TGFBI). METHODS: A slit-lamp examination was performed on individuals from 2 families, one of Mexican descent and a second of Italian descent. After DNA extraction from affected individuals and their unaffected relatives, TGFBI screening was performed. RESULTS: Eight of 20 individuals in the Mexican family and 20 of 55 in the Italian family demonstrated corneal stromal opacities. Seven of the 8 affected individuals in the Mexican family and 4 of the 20 affected individuals in the Italian family demonstrated a phenotype characterized by a "sea fan" or vortex pattern of superficial stromal corneal deposits originating from the inferior aspect of the cornea. Screening of TGFBI in both families revealed a heterozygous missense mutation [p.(Arg555Trp)] in exon 12, confirming the diagnosis of GCD1. CONCLUSIONS: Our findings demonstrate that GCD1 may present with a vortex pattern of anterior stromal deposits. Although this pattern of dystrophic deposits is not recognized by clinicians as a typical phenotype of GCD1, it is consistent with the production of the majority of the TGFBI protein by the corneal epithelium.

Relationship Between Binocular Summation and Stereoacuity After Strabismus Surgery.

PURPOSE: To describe the relationship between binocular summation and stereoacuity after strabismus surgery. DESIGN: Prospective case series. METHODS: setting: Stein Eye Institute, University of California Los Angeles. PATIENT POPULATION: Pediatric strabismic patients who underwent strabismus surgery between 2010 and 2015. OBSERVATION PROCEDURES: Early Treatment Diabetic Retinopathy Study visual acuity, Sloan low-contrast acuity (LCA, 2.5% and 1.25%), and Randot stereoacuity 2 months following surgical correction of strabismus. MAIN OUTCOME MEASURES: The relationship between binocular summation (BiS), calculated as the difference between the binocular visual acuity score and that of the better eye, and stereoacuity. RESULTS: A total of 130 postoperative strabismic patients were studied. The relationship between binocular summation and stereoacuity was studied by Spearman correlation. There were significant correlations between BiS for 2.5% LCA with near and distance stereoacuity (P = .006 and P = .009). BiS for 1.25% LCA was also significantly correlated with near stereoacuity (P = .04). Near stereoacuity and BiS for 2.5% and 1.25% LCA were significantly dependent (Pearson χ(2), P = .006 and P = .026). Patients with stereoacuity demonstrated significantly more BiS in 2.5% LCA of 2.7 (P = .022) and 3.1 (P = .014) letters than did those without near or distance stereoacuity, respectively. CONCLUSIONS: These findings demonstrate that stereopsis and binocular summation are significantly correlated in patients who have undergone surgical correction of strabismus.

The effectiveness of cast wedging for the treatment of pediatric fractures.

We present the results of cast wedging for correction of alignment during the closed treatment of tibial and radial shaft fractures in children. We retrospectively reviewed the radiographic and clinical outcome of 249 cast wedges performed after reangulation of a previously manipulated tibial or radial shaft fracture. A mean improvement of close to 5 in coronal alignment was observed. A satisfactory outcome was obtained in 96% of patients with tibial fractures and 94% of patients with radial fractures. Cast wedging is a safe and effective tool for the treatment of angulated, pediatric tibial and radial shaft fractures.

3'-monoiodothyronine sulfate and Triac sulfate are thyroid hormone metabolites in developing sheep.

We used novel 3'-monoiodothyronine sulfate (3'-T1S) and 3,3',5-triiodothyroacetic acid sulfate (TriacS) RIAs to characterize sulfation pathways in fetal thyroid hormone metabolism. 3'-T1S and TriacS levels were measured in serum samples obtained from fetal (n = 21, 94-145 d gestational age), newborn (NB, n = 5), and adult sheep (AD, n = 5) as well as from fetuses after total thyroidectomy (Tx), or sham-operated twin fetuses controls, conducted at gestational age 110-113 d (n = 5). Peak levels (expressed as ng/dL) of both 3'-T1S and TriacS occurred at 130 d gestation. These levels in fetuses were higher than those in NB and AD. In Tx fetuses, there was a significant decrease in the mean serum level of 3'-T1S, but not TriacS. The decrease in 3'-T1S in Tx is similar to that observed for thyroxine sulfate (T4S) and 3,3',5'-triiodothyronine sulfate (rT3S), whereas TriacS levels were not altered in the hypothyroid state, similarly to 3,3',5-triiodothyronine sulfate (T3S). These data demonstrate that 3'-T1S and TriacS are normal thyroid hormone metabolites in ovine serum and that TriacS is likely derived from T3S or from the same precursor(s) as T3S.