The Effect on Retinal Structure and Function of 15 Specific ABCA4 Mutations: A Detailed Examination of 82 Hemizygous Patients

Purpose: To determine the effect of 15 individual ABCA4 mutations on disease severity. Methods: Eighty-two patients harboring 15 distinct ABCA4 mutations in trans with null (hemizygous), 10 homozygous, and 20 nullizygous patients were recruited. Age of onset was determined from medical histories. Electroretinography (ERG) responses were classified into three groups (normal; cone dysfunction; cone and rod dysfunction). The dark-adapted bright-flash (DA 10.0) a-wave amplitudes and the light-adapted flicker ERG (LA 3.0 30 Hz) amplitudes were plotted against age and compared with the nullizygous patients. Fundus autofluorescence imaging (FAF) was assessed when available. Results: Patients hemizygous for p.G1961E and p.R2030Q had normal ERGs. Patients harboring p.R24H, p.R212C, p.G863A/delG, p.R1108C, p.P1380L, p.L2027F, and c.5714+5G>A had abnormal ERGs (ERG group 2 or 3) at older ages, in most cases with significantly higher amplitudes than nullizygous patients. Mutations p.L541P+A1038V, p.E1022K, p.C1490Y, p.E1087K, p.T1526M, and p.C2150Y were associated with abnormal ERGs (group 2 or 3) and amplitudes comparable to those of nullizygous patients. The majority of patients, including those harboring p.G1961E, had foveal atrophy; while both patients harboring p.R2030Q had foveal sparing. Most patients harboring intermediate and null-like mutations displayed FAF abnormalities extending beyond the vascular arcades. Conclusions: In the hemizygous state, 2/15 ABCA4 alleles retain preserved peripheral retinal function; 7/15 are associated with either preserved or only mildly abnormal retinal function, worse in older patients; 6/15 behave like null mutations. These data help characterize the degree of dysfunction conferred by specific mutant ABCA4 proteins in the human retina

ABCA4-associated disease as a model for missing heritability in autosomal recessive disorders: novel noncoding splice, cis-regulatory, structural, and recurrent hypomorphic variants

PURPOSE: ABCA4-associated disease, a recessive retinal dystrophy, is hallmarked by a large proportion of patients with only one pathogenic ABCA4 variant, suggestive for missing heritability. METHODS: By locus-specific analysis of ABCA4, combined with extensive functional studies, we aimed to unravel the missing alleles in a cohort of 67 patients (p), with one (p = 64) or no (p = 3) identified coding pathogenic variants of ABCA4. RESULTS: We identified eight pathogenic (deep-)intronic ABCA4 splice variants, of which five are novel and six structural variants, four of which are novel, including two duplications. Together, these variants account for the missing alleles in 40.3% of patients. Furthermore, two novel variants with a putative cis-regulatory effect were identified. The common hypomorphic variant c.5603A>T p.(Asn1868Ile) was found as a candidate second allele in 43.3% of patients. Overall, we have elucidated the missing heritability in 83.6% of our cohort. In addition, we successfully rescued three deep-intronic variants using antisense oligonucleotide (AON)-mediated treatment in HEK 293-T cells and in patient-derived fibroblast cells. CONCLUSION: Noncoding pathogenic variants, novel structural variants, and a common hypomorphic allele of the ABCA4 gene explain the majority of unsolved cases with ABCA4-associated disease, rendering this retinopathy a model for missing heritability in autosomal recessive disorders

Fabrication of Superhydrophilic Polyester Fabrics Using Various TiO₂ Colloidal Dispersions

The purpose of this research was to apply four stable colloidal dispersions, combining different TiO₂ core-shell nanoparticles, onto polyester fabric, according to exhaustion procedure, in order to enhance fabrics' water and moisture absorption properties. Firstly, all colloidal dispersions were analysed using transmission electron microscopy (TEM) and dynamic light scattering (DLS) and secondly, the morphologies of TiO₂ modified PES surfaces were evaluated by scanning electron microscopy (SEM). In addition, the superhydrophilic character of fibrous surfaces was investigated by water contact angle measurement. For this purpose, dynamic tensiometry was employed by measuring the changes in the net force on a surface during the repeated immersion and emersion of a solid into a probe liquid. The obtained results show excellent wettability of TiO₂ upgraded PES fabrics depending on the type of applied nano-sized TiO₂-hybride

The Role of TiO₂ Nanoparticles on the UV Protection Ability and Hydrophilicity of Polyamide Fabrics

The focus of this study was to characterize three industrially-prepared (via the sulphate synthesis process) nano-TiO₂ colloidal dispersions with the intention to elucidate their role on the hydrophilicity as well as UV shielding ability when applied onto polyamide fabric. Transmission electron microscopy (TEM) and UV spectrophotometry of the selected dispersions proved the presence of TiO₂ nanoparticles of different shapes and sizes, as well as its imposing absorption capability within the UV region. In addition, TiO₂ dispersions in three concentrations accompanied by selected chemicals and auxiliaries were applied on polyamide fabrics according to standard exhaustion procedure. Scanning electron microscopy (SEM) was adopted in order to analyse the morphological structure of nano-TiO₂-upgraded PA fabrics. Furthermore, the UV-protective ability and hydrophilic properties were evaluated. The gained results show excellent blocking properties against UV-rays (UPF 50+), as well as the (super)hydrophilicity of TiO₂-modified PA fabrics, regarding the type of employed TiO₂ colloidal dispersion

Primary functional and aesthetic restoration of the fingernail in distal fingertip amputations with the eponychial flap

Fingertip injuries often result in fingernail defects. Reconstruction of this structure is important for adequate functional and aesthetic results. This study evaluates the eponychial flap reconstruction technique in 45 fingertip amputations with loss of more than half the fingernail. In 33 cases the procedure was performed in combination with a palmar island flap for pulp reconstruction. Average follow up was 5 months. All eponychial flaps healed uneventfully. In 44 cases, the pulp volume was restored without nail growth disturbance. Five complications (9%) were observed (pain, soft nail, and nail deformity). Only one hook nail deformity required reoperation. All patients were satisfied with the aesthetic and functional outcome. We found eponychial flap fingernail reconstruction effective even for injuries proximal to the lunula and have extended the indication for this technique to very proximal fingernail defects. Eponychial flap reconstruction is a simple, safe, and time-effective technique without donor site morbidity. Simultaneous reconstruction of dorsal and palmar injuries should both be performed primarily resulting in the restoration of a satisfying fingertip

Prolonged amelioration of acute lung allograft rejection by sequential overexpression of human interleukin-10 and hepatocyte growth factor in rats

The effect of prolonged electroporation-mediated human interleukin-10 (hIL-10) overexpression 24 hours before transplantation, combined with sequential human hepatocyte growth factor (HGF) overexpression into skeletal muscle on day 5, on rat lung allograft rejection was evaluated. Left lung allotransplantation was performed from Brown-Norway to Fischer-F344 rats. Gene transfer into skeletal muscle was enhanced by electroporation. Three groups were studied: group I animals (n = 5) received 2.5 μg pCIK-hIL-10 (hIL-10/CMV [cytomegalovirus] early promoter enhancer) on day -1 and 80 μg pCIK-HGF (HGF/CMV early promoter enhancer) on day 5. Group II animals (n = 4) received 2.5 μg pCIK-hIL-10 and pUbC-hIL-10 (hIL-10/pUbC promoter) on day -1. Control group III animals (n = 4) were treated by sham electroporation on days -1 and 5. All animals received daily nontherapeutic intraperitoneal dose of cyclosporin A (2.5 mg/kg) and were sacrificed on day 15. Graft oxygenation and allograft rejection were evaluated. Significant differences were found between study groups in graft oxygenation (Pao(2)) (P = .0028; group I vs. groups II and III, P < .01 each). Pao(2) was low in group II (31 ± 1 mm Hg) and in group III controls (34 ± 10 mm Hg), without statistically significant difference between these 2 groups (P = .54). In contrast, in group I, Pao(2) of recipients sequentially transduced with IL-10 and HGF plasmids was much improved, with 112 ± 39 mm Hg (vs. groups II and III; P < .01 each), paralleled by reduced vascular and bronchial rejection (group I vs. groups II and III, P < .021 each). Sequential overexpression of anti-inflammatory cytokine IL-10, followed by sequential and overlapping HGF overexpression on day 5, preserves lung function and reduces acute lung allograft rejection up to day 15 post transplant as compared to prolonged IL-10 overexpression alone

Influence of temperature management on neurocognitive function in biological aortic valve replacement. A prospective randomized trial

Aim of this study was to elucidate if postoperative neurocognitive function after biological aortic valve replacement (AVR) can be influenced by temperature management during cardiopulmonary bypass (CPB)

Phenotype and Progression of Retinal Degeneration Associated With Nullizigosity of ABCA4

PURPOSE: We describe the phenotypes associated with nullizigosity and nine splicing mutations in the ABCA4 gene. METHODS: The study included 19 patients with biallelic null mutations (Group A, nullizygous), 27 with splicing mutations in the homozygous state or in trans with a null mutation (Group B), and 20 with p.G1961E in trans with a null mutation (Group C, control). Ages at onset and visual acuities were determined from medical histories. Area of decreased autofluorescence within a 30° × 30° fundus autofluorescence (FAF) image was measured with the Region Finder (N = 58). Full-field electroretinography (ERG) was performed incorporating the International Society for Clinical Electrophysiology of Vision (ISCEV) standard (N = 40). RESULTS: For groups A to C, the median ages of onset were 6, 8, and 17, respectively. Kaplan Meier survival analysis estimated that 50% of patients reached visual acuity below 20/400 at the ages of 29, 48, and 66 years, respectively. The area of reduced FAF was estimated to increase by 1.5, 1.2, and 0.03 mm2 per year, respectively, and cone-rod dystrophy was present in 10/12, 13/15, and 0/13 of cases, respectively. Splicing mutation c.5714+5G>A was associated with a significantly milder phenotype in comparison with nullizygous patients for all parameters. CONCLUSIONS: Nullizygosity for ABCA4 is associated with early onset cone-rod dysfunction with rapid progression shown by enlargement of central atrophy on FAF, decline of ERG amplitudes with age, and a high risk of reaching legal blindness by the fourth decade. Most studied splicing mutations were associated with a similarly severe phenotype. Estimated rates of progression may facilitate further genotype-phenotype correlations and inform the design of treatment trials