Wavelength-selective light-triggered strand exchange reaction.

We prepared an oligodeoxynucleotide (ODN) bearing two 4-hydroxy-2-mercaptobenzimidazole nucleobase analogues (SB(NV) and SB(NB)) modified with different photolabile groups. This ODN enabled a light-triggered strand exchange reaction in a wavelength-selective manner.

C5-azobenzene-functionalized locked nucleic acid uridine: isomerization properties, hybridization ability, and enzymatic stability.

Oligonucleotides (ONs) modified with a locked nucleic acid (LNA) are widely used in the fields of therapeutics, diagnosis, and nanotechnology. There have been significant efforts towards developing LNA analogues bearing modified bridges to improve their hybridization ability, nuclease resistance, and pharmacokinetic profiles. Moreover, nucleobase modifications of LNA are useful strategies for the functionalization of ONs. Modifications of the C5-position of pyrimidine nucleobases are particularly interesting because they enable predictable positioning of functional groups in the major groove of the duplex. Here we report the synthesis of C5-azobenzene-functionalized LNA uridine (LNA-U(Az)) and properties of LNA-U(Az)-modified ONs, including isomerization properties, hybridization ability, and enzyme stability. LNA-U(Az) in ON is photo-isomerized effectively and reversibly by irradiation at 365 nm (trans to cis) and 450 nm (cis to trans). LNA-U(Az)-modified ONs show RNA-selective hybridization ability despite the large hydrophobic azobenzene moiety extending into the major groove of the duplex. The enzymatic stability of LNA-U(Az)-modified ONs is higher than that of natural and LNA-modified ONs with or without photo-irradiation. Our results indicate that LNA-U(Az) holds promise for RNA targeting and photo-switchable technologies.

Superficial punctate keratopathy and bacterial growth in patients with unilateral aphakia using extended-wear soft contact lenses.

We prospectively examined corneal conditions and bacterial growth in 77 individuals with unilateral aphakia who were using extended-wear soft contact lenses. The ratios of positive bacterial growth (70.6-79.4%) from 34 patients with superficial punctate keratopathy were significantly higher than those (41.9-46.5%) from the 43 subjects with normal corneas. Bacterial growth was found frequently in patients with superficial punctate keratopathy who were older than 80 years and in those using soft contact lenses for more than 22 days. Several kinds of bacteria grew from the specimens. Among the most common were Staphylococcus epidermidis and Corynebacterium species. Pseudomonas aeruginosa grew from patients with superficial punctate keratopathy who were using extended-wear soft contact lenses.

Anomalous macular vessels: case report and review of the recent Japanese literature.

We examined a 19-year-old woman with large macular vessels who had temporarily impaired visual acuity. The anomalous macular vessels had arteriovenous shunts and were associated with abnormal capillary networks. In a review of the recent Japanese literature, we found another eight patients with anomalous macular vessels who had undergone fluorescein angiography. We prefer the term anomalous macular vessels to describe this condition.