A recyclable thermoset with built-in thermocleavable group developed from a cis-cyclobutane-1,2-dicarboxylic acid.

A novel class of recyclable thermoset has been developed from cis-3,4-diphenylcyclobutane-1,2-dicarboxylic acid (CBDA-4) due to its thermocleavability at high temperature. This key CBDA-4 building block was synthesized from ß-trans-cinnamic acid using a [2+2] photocycloaddition reaction. CBDA-4 was subsequently linked with glycerol via esterification to give a thermoset with Tg of 68 °C. The thermoset was heated to 300 °C to analyze its degradation. A key intermediate was successfully obtained after purification of the degraded polymer. NMR, FT-IR, HRMS, and single crystal X-ray diffraction confirmed the intermediate was glycerol cinnamate, which was the result of splitting cyclobutane in the polymer backbone at high temperature. Glycerol cinnamate was readily hydrolyzed reforming the starting materials glycerol and trans-cinnamic acid to complete the recycling loop.

Strategies for increasing the physician workforce: the Oregon model for expansion.

The physician workforce shortage and inequity of physician distribution throughout Oregon require the Oregon Health & Science University (OHSU) School of Medicine to graduate more physicians and increase the number committed to practice in nonurban areas. The most cost-effective and expedient method to accomplish these goals has been to develop community partnerships and regional campuses. However, expansion must be strategically developed to maintain educational quality and to minimize the impact on available resources. Leveraging partnerships with existing health care delivery systems and major state universities makes expansion more expedient and economical. In 2001, the OHSU School of Medicine began implementing a four-phase plan to increase medical student enrollment. Phase 1 (2001-2006) used only capital budget resources to increase enrollment incrementally at the school of medicine's Portland site; Phase 2 (2006-2007) creates community partnerships to develop regional sites using the physical facilities of partners, again avoiding the need for capital investment; Phase 3 (2007-2010) builds on the prototype developed in Phase 2 to create additional regional educational sites; and Phase 4 (2010-2015) involves a feasibility study and subsequent capital campaign for a facility on Portland's south waterfront. Establishing regional campuses and matriculating the student population best suited for the physician workforce of the future are key elements of the OHSU model of expansion, particularly in addressing the state's physician distribution inequities.

Incidence of retinal detachment after fellow-performed primary pars plana vitrectomy.

Background. Primary pars plana vitrectomy (PPV) is often performed by vitreoretinal fellows. We aimed to evaluate the incidence of retinal breaks and detachments (RD) after fellow-performed PPV. Methods. We reviewed 119 consecutive cases of standard 3-port primary PPVs on 115 patients at a teaching institution from 2003 to 2006. In all cases, the primary surgeon was a vitreoretinal fellow. Patients with previous RD were excluded. Cases were reviewed for postoperative retinal detachments, and all patients were followed for up to 1 year. Results. Intraoperative retinal breaks occurred in 5 of 119 eyes (4.2%). One break was associated with sclerotomy and 4 were not. Postoperative RD occurred in 8 of 119 eyes (6.7%). Two RDs were sclerotomy related, 5 were not, and 1 was of indeterminate origin. Conclusions. Incidence of retinal breaks and RD following primary PPV by vitreoretinal fellows is low and comparable to that of fellowship-trained surgeons.

Intraocular cysticercosis by taenia crassiceps.

PURPOSE: The authors present a case of intraocular cysticercosis caused by Taenia crassiceps and provide further insight into this unusual infection. METHODS: The clinical, laboratory, photographic, and histopathologic records of this observational case report are reviewed, as are previously published cases. RESULTS: A healthy 14-year-old girl was referred to the retina service for evaluation of a total retinal detachment in her left eye. She described painless visual loss in this eye of 2 months' duration. The patient underwent a diagnostic vitrectomy to recover the organisms for identification. Thirty to forty larval T crassiceps cysticerci were recovered. CONCLUSION: The clustered proliferation of 1 to 2 mm cysticerci is a distinguishing feature of intraocular cysticercosis due to T crassiceps. The organism can reside in the subretinal space, and may invade through the retina and proliferate in the vitreous cavity. When in the vitreous cavity, inflammation and proliferative vitreoretinopathy may ensue, leading within a few months to severe vision loss due to retinal detachment. Thus far, cases of intraocular T crassiceps have only been reported in female patients.

Vitreous hemorrhage is a common complication of pediatric pars planitis.

OBJECTIVE: To report the prevalence of vitreous hemorrhage in pars planitis and to compare the prevalence of hemorrhage for children and adults with the disease. DESIGN: A retrospective, cross-sectional observational study. PARTICIPANTS: One hundred eighteen consecutive patients with pars planitis who were evaluated at the Oregon Health and Science University Uveitis Clinic between September 1985 and April 2000. METHOD: A review of clinical records. MAIN OUTCOME MEASURES: For all patients, we recorded presence or absence of vitreous hemorrhage, as well as laterality and cause. Children were defined as being age 16 years or younger at diagnosis, and adults were defined as being aged 17 years or older at diagnosis. RESULTS: Fourteen percent of patients with pars planitis experienced vitreous hemorrhage. Persons with hemorrhage were significantly younger at the time of disease diagnosis than persons without hemorrhage (P = 0.040). The difference in prevalence of vitreous hemorrhage between children (28%) and adults (6%) was statistically significant (P = 0.003). The difference in prevalence of hemorrhage as a presenting feature between children (20%) and adults (1%) was also statistically significant (P = 0.001). CONCLUSIONS: Children with pars planitis are more likely than adults to experience vitreous hemorrhage. Pars planitis should be considered in the differential diagnosis of pediatric vitreous hemorrhage.

Recurrent vitreous hemorrhage after sutured posterior chamber intraocular lenses.

PURPOSE: To describe the clinical course and management of patients with late vitreous hemorrhage after scleral suturing of posterior chamber intraocular lenses (PCIOL). METHODS: The authors reviewed patient demographics, ocular findings, and clinical course of six patients with late (>3 weeks) vitreous hemorrhage after sclera-sutured PCIOL. Intraoperative endoscopy was performed on two patients to better assess the haptic sulcus interaction. RESULTS: Patient age ranged from 39 to 84 years (median 77 years). The interval between scleral suturing of the PCIOL and vitreous hemorrhage ranged from 3 weeks to 68 months (median 5 months). The number of hemorrhages ranged from one to four. The hemorrhage cleared spontaneously in three eyes. Three patients underwent surgery after the hemorrhages including sutured PCIOL removal with concurrent placement of an anterior chamber IOL (ACIOL) (two patients) and resuturing of a PCIOL in a different meridian (one patient). Follow-up ranged from 4 to 36 months, median 19.5 months, starting from the time of the initial postsuturing vitreous hemorrhage. Final vision ranged from 20/20 to hand motions, with four eyes having 20/40 or better vision. Endoscopy revealed a haptic embedded into the pars plicata in one eye but no evidence of neovascularization. CONCLUSION: Recurrent vitreous hemorrhage may occur as a complication of scleral suturing of PCIOL. The etiology of these hemorrhages does not appear to be related to neovascular proliferation at the haptic suture site, but may be secondary to erosion of the haptic into uveal structures. Not all eyes require reoperation after these hemorrhages; however, good visual results may be achieved by replacing the sutured PCIOL with an ACIOL or by suturing the PCIOL in a different meridian.