Pediatric Conjunctivitis: A Review of Clinical Manifestations, Diagnosis, and Management.

Conjunctivitis is a common pediatric problem and is broadly divided into infectious and non-infectious etiologies. Bacterial conjunctivitis makes up the majority of cases in children and often presents with purulent discharge and mattering of the eyelids. Treatment is supportive with an individual approach to antibiotic use in uncomplicated cases since it may shorten symptom duration, but is not without risks. Viral conjunctivitis is the other infectious cause and is primarily caused by adenovirus, with a burning, gritty feeling and watery discharge. Treatment is supportive. Allergic conjunctivitis is largely seasonal and presents with bilateral itching and watery discharge. Treatment can include topical lubricants, topical antihistamine agents, or systemic antihistamines. Other causes of conjunctivitis include foreign bodies and non-allergic environmental causes. Contact lens wearers should always be treated for bacterial conjunctivitis and referred to evaluate for corneal ulcers. Neonatal conjunctivitis requires special care with unique pathogens and considerations. This review covers essential information for the primary care pediatric provider as they assess cases of conjunctivitis.

Restoration of cellular integrity following "ballistic" pronuclear exchange during Tetrahymena conjugation.

During sexual reproduction or conjugation, ciliates form a specialized cell adhesion zone for the purpose of exchanging gametic pronuclei. Hundreds of individual membrane fusion events transform the adhesion zone into a perforated membrane curtain, the mating junction. Pronuclei from each mating partner are propelled through this fenestrated membrane junction by a web of short, cris-crossing microtubules. Pronuclear passage results in the formation of two breaches in the membrane junction. Following pronuclear exchange and karyogamy (fertilization), cells seal these twin membrane breaches thereby re-establishing cellular independence. This would seem like a straightforward problem: simply grow membrane in from the edges of each breach in a fashion similar to how animal cells "grow" their cytokinetic furrows or how plant cells construct a cell wall during mitosis. Serial section electron microscopy and 3-D electron tomography reveal that the actual mechanism is less straightforward. Each of the two membrane breaches transforms into a bowed membrane assembly platform. The resulting membrane protrusions continue to grow into the cytoplasm of the mating partner, traverse the cytoplasm in anti-parallel directions and make contact with the plasma membrane that flanks the mating junction. This investigation reveals the details of a novel, developmentally-induced mechanism of membrane disruption and restoration associated with pronuclear exchange and fertilization in the ciliate, Tetrahymena thermophila.