The macular choroidal thickness and volume in the pediatric individuals were significantly larger than those in the adults. The pediatric choroidal thinning with increasing age is more rapid in the central area. Pediatric choroidal thickness is associated with several systemic or ocular parameters, especially the axial length and body mass index. These differences should be remembered when the choroidal thickness is evaluated in pediatric patients with retinochoroidal diseases.

With recent development of spectral-domain optical coherence tomography (SD-OCT), the pathological changes of retina can be observed in much greater detail. SD-OCT clearly delineates three highly reflective lines in the outer retina, which are external limiting membrane (ELM), photoreceptor inner and outer segment (IS/OS) junction, and cone outer segment tips (COST) in order from inside. These lines can serve as hallmarks for the evaluation of photoreceptor condition. In retinitis pigmentosa (RP) leading to photoreceptor degeneration, the ELM, IS/OS, and COST lines are shortened with the progression of the disease. In addition, shortening of the ELM, IS/OS and COST lines is significantly associated with each other. The line length is longest in the ELM, followed by the IS/OS, and COST, suggesting that retinal layer becomes disorganized first at the COST, followed by the IS/OS and finally the ELM. This finding is consistent with the previous report that the earliest histopathological change in RP is a shortening of the photoreceptor outer segments. On the other hand, retinal layer becomes restored first at the ELM, followed by the IS/OS and finally the COST after macular hole surgery. There may be a directionality of photoreceptor impairment or restoration on optical coherence tomographic image.

Peptides derived from the α-helical domains of human immunodeficiency virus (HIV) type 1 (HIV-1) gp41 inhibit HIV-1 fusion to the cell membrane. Enfuvirtide (T-20) is a peptide-based drug that targets the step of HIV fusion, and as such, it effectively suppresses the replication of HIV-1 strains that are either wild type or resistant to multiple reverse transcriptase and/or protease inhibitors. However, HIV-1 variants with T-20 resistance have emerged; therefore, the development of new and potent inhibitors is urgently needed. We have developed a novel HIV fusion inhibitor, SC34EK, which is a gp41-derived 34-amino-acid peptide with glutamate (E) and lysine (K) substitutions on its solvent-accessible site that stabilize its α-helicity. Importantly, SC34EK effectively inhibits the replication of T-20-resistant HIV-1 strains as well as wild-type HIV-1. In this report, we introduce SC29EK, a 29-amino-acid peptide that is a shorter variant of SC34EK. SC29EK blocked the replication of T-20-resistant HIV-1 strains and maintained antiviral activity even in the presence of high serum concentrations (up to 50%). Circular dichroism analysis revealed that the α-helicity of SC29EK was well maintained, while that of the parental peptide, C29, which showed moderate and reduced inhibition of wild-type and T-20-resistant HIV-1 strains, was lower. Our results show that the α-helicity in a peptide-based fusion inhibitor is a key factor for activity and enables the design of short peptide inhibitors with improved pharmacological properties.

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The design, synthesis, and bioevaluation of fluorescence- and biotin-labeled CXCR4 antagonists are described. The modification of D-Lys8 at an epsilon-amino group in the peptide antagonist Ac-TZ14011 derived from polyphemusin II had no significant influence on the potent binding of the peptide to the CXCR4 receptor. The application of the labeled peptides in flow cytometry and confocal microscopy studies demonstrated the selectivity of their binding to the CXCR4 receptor, but not to CXCR7, which was recently reported to be another receptor for stromal cell-derived factor 1 (SDF-1)/CXCL12.