No abstract

and azoisobutyronitrile (3.24 g.) were refluxed in 30 ml. of benzene for 8 hr. under nitrogen. The benzene and tetramethylsuccinonitrile were removed by steam distillation. The yellow residue was dissolved in benzene, dried, and the solvent was removed by heating on the steam-bath for 1 hr. in vacuo.The yellow glass which resulted (1.82 g.) did not form a crystalline picrate. Seeding of 187 mg. of this material in benzene-absolute ethanol with a crystal of dihydro-bis-(cyanopropyl)-benzpyrene (X, m.p. 222-224°) yielded 10 mg. of white crystals, m.p. 220-224°. Dehydrogenation of the yellow glass with sulfur at 215°a nd with 10% palladium-charcoal at 315°yielded benzpyrene as the sole identifiable product. Dehydrogenation with chloranil in boiling xylene for 47 hr. yielded an impure sample of X.Dehydrogenation of Dihydro-bis-(cyanopropyl)-benzpyrene (X).-The bis-compound X (29 mg., m.p. 208-220°) was mixed with 4 mg. of 10% palladium-charcoal and heated under nitrogen at 315°for 1 hr. in a sublimation apparatus. The sublimate was rinsed into the apparatus with benzene, the benzene was removed on the steam-bath, and the material was heated at 315°for 1 hr. more.The mixture was dissolved in benzene, filtered and was concentrated on the steam-bath under nitrogen. The residue could not be recrystallized from benzene-hexane; it was therefore sublimed at 140-165°( 0.1 mm.), and the yellow sublimate (9.2 mg.) was recrvstallized from benzene-hexane. The yellow crystals obtained (4.5 mg.) melted at 176-178°and gave no depression on mixed m.p. with authentic benzpyrene.

(II) respectively. There are no unusually short intermolecular distances.

Purpose: To report a case of paracentral acute middle maculopathy in a pediatric patient with sickle cell trait.Methods: The patient was evaluated with a comprehensive ophthalmic examination, optical coherence tomography, optical coherence tomography angiography, and fluorescein angiography.Results: Acute loss of vision occurred immediately after an uneventful scleral buckling procedure for retinal detachment in a 16-year-old female patient. Retinal imaging studies confirmed the occurrence of paracentral acute middle maculopathy, an ischemic condition characterized by infarction of the inner nuclear layer of the retina caused by hypoperfusion of the intermediate and deep capillary plexuses. Laboratory evaluation was only remarkable for sickle cell trait. Over a course of 3 months after the loss of vision, visual acuity improved from 20/1,000 to 20/20, and optical coherence tomography lesion resolved to a parafoveal area of inner and middle retinal layer thinning. Paracentral scotoma corresponding to the atrophic area persisted.Conclusion: Dehydration because of the presurgical nil-per-os status and transient increase in intraocular pressure during the buckling surgery may have predisposed this patient with sickle cell trait to a sickling event that caused localized ischemia in the middle retina's end-capillaries. Avoiding long nil-per-os status, being mindful of transient intraocular pressure elevation during scleral buckling procedures, and presurgical hemoglobin electrophoresis in at-risk populations are recommended to prevent sickling attacks during retinal surgeries in individuals with sickle cell trait.