Search

Genetic screens in Drosophila melanogaster have long been used to identify genes found in a variety of developmental, cellular, and behavioral processes. Here we describe the characterization and mapping of a mutation identified in a conditional screen for genetic regulators of cell growth and cell division. Within a Flp/FRT system, mutant G.3.2 results in a reduction of mutant tissue and a rough eye phenotype. We find that G.3.2 maps to the gene cnk , providing further support that cnk is a critical gene in Drosophila eye development. This mutant was characterized, mapped and sequenced by undergraduate students within the Fly-CURE consortium., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2024 by the authors.)

A dart entered the eye of a 6-year-old boy causing a retinal hole located inferotemporal to the macula. The retinal hole was treated with an argon laser, and two months after the injury, tissue organization in the vitreous track created by the dart caused a limited retinal separation and stress lines. A preretinal fibrosis developed above and temporal to the macula, and visual acuity decreased to 6/60 (20/200). Four months after the injury, the preretinal membrane spontaneously separated from the macula to an extramacular nidus, and visual acuity subsequently improved to 6/9 (20/30).

Two intravitreal Taenia cysts were removed intact by pars plana vitrectomy from a 59-year-old woman who had never left the continental United States. The intraocular course of the cysts progressed from an initial chorioretinal location, accompanied by an intense focal inflammatory reaction, to free floating in the vitreous cavity within two months; thereafter, there was only a low-grade vitritis for an additional five months until removal. Light and electron microscopic studies suggested Cysticercus cellulosae as the infecting agent, although mature hooklets were absent. Local pork products were considered to be the source of the infection. Preretinal fibrosis and posterior subcapsular vacuoles were the final residua and did not progress after removal of the cysts. Although uncommon in the United States, cysticercosis should be considered in cases of focal necrotizing chorioretinitis.

Genetic linkage studies were conducted on five Old Order Amish bipolar pedigrees in 1979 and 1982, with 94 members tested for color blindness and typed for 42 red blood cell and related markers in 17 antigen systems. Also, 59 individuals in two pedigrees were typed for HLA, Bf, and GLO. Linkage analyses assuming X-linkage and autosomal inheritance of bipolar illness were done with diagnostic schemes ranging from strict bipolar to milder forms of affective disorder. Linkage to affective disorders was not strongly supported for any marker locus. Close linkage to HLA was excluded, with weaker evidence against linkage to GLO.

Three young adult patients are described to illustrate an uncommon syndrome, papillophlebitis. This entity, characterized by mild but protracted monocular visual impairment, edema of the optic disc, retinal venous engorgement, and perivenous retinal hemorrhages, resembles atherosclerotic occlusion of the central retinal vein in older patients. In younger individuals it is benign and self limited, but may be incorrectly diagnosed as optic neuritis or papilledema. These alternatives can usually be excluded if tests of visual function do not indicate an optic nerve conduction defect and if the clinical presentation and examination of the opposite ocular fundus do not disclose evidence of increased intracranial pressure. Because resolution usually occurs spontaneously, immediate neuroroentgenographic tests may be inappropriate. Effective treatment has not been established; local instillation of corticosteroids may hasten recovery.

Newborn stump-tail monkeys were continuously exposed to 400 f-c of cool, white, fluorescent light for periods varying from 12 hr to 7 days. The right eye of each monkey was occluded by a patch of black velour material to serve as a control. The protected eyes retained normal ultrastructure; the exposed eyes showed progressive damage to the retina from the 12 hr to the 7-day exposure periods. Early changes were evident in the outer nuclear layer with darkly staining pyknotic nuclei and electrondense cytoplasmic processes that could be traced to their synaptic terminals. Late changes included marked distortion, vacuolization, and fragmentation of the rod and cone outer segments. The potential for phototoxicity to be additive to the normal aging of the retina is proposed, and we conclude that there is a sound basis for the current practice of patching the eyes of infants undergoing phototherapy.