An artificial metalloenzyme biosensor can detect ethylene gas in fruits and Arabidopsis leaves.

Enzyme biosensors are useful tools that can monitor rapid changes in metabolite levels in real-time. However, current approaches are largely constrained to metabolites within a limited chemical space. With the rising development of artificial metalloenzymes (ArM), a unique opportunity exists to design biosensors from the ground-up for metabolites that are difficult to detect using current technologies. Here we present the design and development of the ArM ethylene probe (AEP), where an albumin scaffold is used to solubilize and protect a quenched ruthenium catalyst. In the presence of the phytohormone ethylene, cross metathesis can occur to produce fluorescence. The probe can be used to detect both exogenous- and endogenous-induced changes to ethylene biosynthesis in fruits and leaves. Overall, this work represents an example of an ArM biosensor, designed specifically for the spatial and temporal detection of a biological metabolite previously not accessible using enzyme biosensors.

Ocular findings in Japanese children with Down syndrome: the course of visual acuity and refraction, and systemic and ocular anomalies.

PURPOSE: To investigate the age-related development of refractive errors and changes of visual acuity (VA), and the systemic and ocular anomalies in Japanese children and young adults with Down syndrome (DS). DESIGN: Retrospective cohort study. SUBJECTS AND METHODS: This study involved 222 Japanese children and young adults with DS (age range: 3 months to 19 years) seen at the Department of Ophthalmology, Shiga Medical Center for Children, Shiga, Japan. The subjects were divided into the following six age groups: 1) infant (age 0 to <4 years), 2) preschool (age 4 to <7 years), 3) lower primary-school grades (age 7 to <10 years), 4) upper primary-school grades (age 10 to <13 years), 5) junior high school (age 13 to <16 years), and 6) late teen/young adults (age 16 to <20 years). Through examination of the subjects' medical charts, we investigated the development and changes of refractive errors and VA, best-corrected VA (BCVA), and systemic and ocular anomalies. RESULTS: For vision testing, Teller Acuity Cards™ (Bernell Corporation) were used for the infants, and the Landolt ring was used for the school-age children. VA was found to develop with age. Mean BCVA was 0.19±0.17 logarithm of the minimum angle of resolution (mean age: 11.3±3.2 years). Mean of refractive errors was hyperopia in the infant (2.2±2.4 diopters [D] OD, 2.4±2.5D OS), yet became myopia to the junior high school (-0.3±4.4D OD, -0.2±4.4D OS). CONCLUSION: Our findings revealed that in children and in late-teen and young-adult subjects with DS, VA slowly develops and that refractive errors requiring correction exist and are difficult to examine.

A Case of Hydranencephaly in Which Ophthalmic Examinations Were Performed.

PURPOSE: We performed ophthalmic examinations, including optical coherence tomography (OCT), on a case diagnosed with hydranencephaly. CASE REPORT: This case involved a female infant born at the gestational age of 35 weeks and 4 days, with the birth weight of 2,152 g, who was one of monochorionic diamniotic twins, and the identical twin died in utero at the gestational age of 24 weeks. After that, examination by fetal echo indicated that she had microcephaly and ventriculomegaly. Postnatal magnetic resonance imaging (MRI) of her head indicated microcephaly and significant enlargement of the lateral ventricle on both sides, with no obvious signs of elevated intracranial pressure. The brain parenchyma of both sides of the frontal lobe, parietal lobe, and occipital lobe had marked thinning, yet that of the temporal lobe, basal ganglia, thalamus, brain stem, and cerebellum had been maintained. Moreover, no obvious hematoma or neoplastic lesions were observed. Ophthalmic examinations indicated that both of her eyes had slight light reflex, attributed to optic nerve atrophy. Examination by use of a hand-held OCT system indicated a layered structure of the retina and thinning of the ganglion cell layer. Flicker electroretinogram (ERG) examination by use of a hand-held ERG system indicated an almost normal wave. However, no clear visual reaction was observed when she was 10 months old. CONCLUSION: Our findings in this case of hydranencephaly revealed that even though the outer layer functions of the patient's retina were maintained, extensive damage to her cerebral cortex resulted in poor visual function.

Selective Halogen-Lithium Exchange of 1,2-Dihaloarenes for Successive [2+4] Cycloadditions of Arynes and Isobenzofurans.

Successive [2+4] cycloadditions of arynes and isobenzofurans by site-selective halogen-lithium exchange of 1,2-dihaloarenes were developed, allowing the rapid construction of polycyclic compounds which serve as a useful synthetic intermediates for the preparation of various polyacene derivatives.

A new synthetic route to substituted tetracenes and pentacenes via stereoselective [4+2] cycloadditions of 1,4-dihydro-1,4-epoxynaphthalene and isobenzofuran.

Stereoselective [4+2] cycloadditions of 1,4-dihydro-1,4-epoxynaphthalene and isobenzofuran were described. Among several possibilities, syn-exo and/or anti-endo isomers were selectively produced depending on the substitution pattern of the reactants. Importantly, the syn-exo isomer underwent acid promoted aromatization, affording the corresponding tetracene. These findings enabled us to prepare a substituted pentacene with electron withdrawing groups.

Dibromoisobenzofuran as a formal equivalent of didehydroisobenzofuran: reactive platform for expeditious assembly of polycycles.

Two-directional annulation of dibromoisobenzofuran, a formal equivalent to didehydroisobenzofuran, was developed. Importantly, selective bromine-lithium exchange allows the tandem generation of benzynes and dual cycloadditions with two different arynophiles. Also described is the application to the synthesis of a substituted pentacene.

[Case of retinal ischemia and retinal arteritis secondary to intravitreal nuclear drop].

BACKGROUND: A rare case of retinal arteritis and retinal ischemia as an incomplete branch retinal artery occlusion is reported following dropped lens fragments into the vitreous body. CASE: A 69 year-old-woman had a cataract OD with corrected visual acuity of 0.4. When she underwent phacoemulsification on March 11, the posterior capsule was damaged and nucleus fragments dropped into a vitreous body. A few days later, the vitreous opacity increased. The corrected visual acuity OD dropped to 0.06 due to anterior chamber inflammation and the intraocular pressure increased to 26 mmHg. During a pars plana vitrectomy on May 7, some retinal whitening were observed and incomplete branch retinal artery occlusion was confirmed by fluorescence fundus angiography. The corrected visual acuity finally improved to 0.3, but the right visual field defect remained. CONCLUSION: Incomplete branch retinal artery occlusion caused by phacoanaphylactic endophthalmitis secondary to lens fragments in the vitreous cavity seems to be a rare condition related to retinal whitening. The timing of pars plana vitrectomy should be considered before retinal arterial sheathing or retinal whitening can be noted.