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Biomedical subjects

Bradley T Smith

Publications and source records attributed to Bradley T Smith.

13 recordsLinked to original sources

Proceedings of the Third International Symposium on Retinopathy of Prematurity: an update on ROP from the lab to the nursery (November 2003, Anaheim, California).

The Third International Symposium on Retinopathy of Prematurity (ROP) was convened with the aim of cross fertilizing the horizons of basic and clinical scientists with an interest in the pathogenesis and management of infants with ROP. Ten speakers in the clinical sciences and ten speakers in the basic sciences were recruited on the basis of their research to provide state of the art talks. The meeting was held November 9, 2003 immediately prior to the American Academy of Ophthalmology meeting; scholarships were provided for outreach to developing countries and young investigators. This review contain the summaries of the 20 platform presentations prepared by the authors and the abstracts of presented posters. Each author was asked to encapsulate the current state of understanding, identify areas of controversy, and make recommendations for future research. The basic science presentations included insights into the development of the human retinal vasculature, animal models for ROP, growth factors that affect normal development and ROP, and promising new therapeutic approaches to treating ROP like VEGF targeting, inhibition of proteases, stem cells, ribozymes to silence genes, and gene therapy to deliver antiangiogenic agents. The clinical presentations included new insights into oxygen management, updates on the CRYO-ROP and ETROP studies, visual function in childhood following ROP, the neural retina in ROP, screening for ROP, management of stage 3 and 4 ROP, ROP in the third world, and the complications of ROP in adult life. The meeting resulted in a penetrating exchange between clinicians and basic scientists, which provided great insights for conference attendees. The effect of preterm delivery on the normal cross-talk of neuroretinal and retinal vascular development is a fertile ground for discovering new understanding of the processes involved both in normal development and in retinal neovascular disorders. The meeting also suggested promising potential therapeutic interventions on the horizon for ROP.

Humans↗

Retinopathy of prematurity: the life of a lifetime disease.

PURPOSE: To provide information on retrolental fibroplasias (RLF), later known as retinopathy of prematurity. DESIGN: Review of the literature on the subject and a first-person account of what was then RLF by one of the authors (A.P.) who was involved in the earliest days in research regarding RLF. METHODS: MEDLINE search on the topics of RLF and retinopathy of prematurity plus a first-person historic review of original work that dealt with RLF. RESULTS: In 1942, elevated levels of oxygen were thought to play a major role in the development of the disease; at that time, no treatment was available. During the lifetime of this disease, other possible causes have been investigated. These include vitamin E as a prophylaxis against retinopathy of prematurity and the efficacy of light reduction to prevent retinopathy of prematurity. It has been shown that the light reduction does not play a role in reducing the progression of retinopathy of prematurity. Vitamin E studies were inconclusive; some studies show a positive effect and others do not. A major advance occurred with the development of the International Classification of Ophthalmology in 1984, which laid the groundwork for collaborative studies to determine whether cryotherapy of the avascular zone of retina would reduce the incidence of blindness in newborn infants, when compared with control subjects. The study showed that cryotherapy was effective; this was followed by laser photocoagulation when lasers became portable enough to take to the neonatal intensive care unit. At the same time, improved surgical techniques moved from scleral buckling for retinal detachment to vitrectomies (some lens sparing) for more desperate cases that had progressed to stage 4 and stage 5 retinopathy of prematurity. Late changes in adults who were born before any treatment and are now baby boomers ran the gamut from the dragging of the retina in the posterior pole to retinal detachment, cataract, and myopia. CONCLUSION: Retinopathy of prematurity is a lifetime disease for which preventive and better treatment modalities continue to evolve.

Animals↗

Atlantic storm.

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Bioterrorism↗

Navigating the storm: report and recommendations from the Atlantic Storm exercise.

Atlantic Storm was a tabletop exercise simulating a series of bioterrorism attacks on the transatlantic community. The exercise occurred on January 14, 2005, in Washington, DC, and was organized and convened by the Center for Biosecurity of UPMC, the Center for Transatlantic Relations of Johns Hopkins University, and the Transatlantic Biosecurity Network. Atlantic Storm portrayed a summit meeting of presidents, prime ministers, and other international leaders from both sides of the Atlantic Ocean in which they responded to a campaign of bioterrorist attacks in several countries. The summit principals, who were all current or former senior government leaders, were challenged to address issues such as attaining situational awareness in the wake of a bioattack, coping with scarcity of critical medical resources such as vaccine, deciding how to manage the movement of people across borders, and communicating with their publics. Atlantic Storm illustrated that much might be done in advance to minimize the illness and death, as well as the social, economic, and political disruption, that could be caused by an international epidemic, be it natural or the result of a bioterrorist attack. These lessons are especially timely given the growing concerns over the possibility of an avian influenza pandemic that would require an international response. However, international leaders cannot create the necessary response systems in the midst of a crisis. Medical, public health, and diplomatic response systems and critical medical resources (e.g., medicines and vaccines) must be in place before a bioattack occurs or a pandemic emerges.

Atlantic Ocean↗

Light energy, cataract surgery, and progression of age-related macular degeneration.

PURPOSE OF REVIEW: Some studies suggest an association between light exposure and increased risk of advanced age-related macular degeneration. The natural lens serves as a barrier to some of the higher energy light rays. There is some concern that cataract surgery may be contributing to the increase in prevalence of age-related macular degeneration. RECENT FINDINGS: It has been shown that blue light absorption by retinal pigment epithelium results in free radical formation, leading to cellular injury, and that blue filters can reduce this rate of cell death. Other studies have shown a tendency for pseudophakic eyes to progress to the wet form of age-related macular degeneration more so than their fellow eyes. SUMMARY: Currently there is no conclusive evidence to support a relation between progression of age-related macular degeneration and cataract surgery. Given that nearly two million cataract extractions are performed yearly, a large randomized controlled study is required to prove or disprove the ability of tinted intraocular lenses to aid in preventing the progression of age-related macular degeneration.

Cataract Extraction↗

Retinopathy of prematurity: late complications in the baby boomer generation (1946-1964).

PURPOSE: To report the natural history and late complications of retinopathy of prematurity (ROP) in members of the baby boomer generation (1946-1964). METHODS: Retrospective observational series of 86 eyes from 47 adult ROP patients (aged 45 to 56 years) who did not receive treatment as infants. Posterior segment pathology, refractive status, lens status, and visual acuity were evaluated. RESULTS: Seventy-six eyes (88.4%) had posterior segment pathology due to ROP, including 22 (25.6%) with retinal detachments. The rates of myopia and cataract formation were 90.7% and 83.7%, respectively. Visual acuity was 20/200 or worse in 43 eyes (51.2%) and 20/60 or better in 35 (41.7%). CONCLUSIONS: There are significant late complications of ROP underscoring the importance of lifelong follow-up.

Cataract↗

Adverse reaction characterized by chest pain, shortness of breath, and syncope associated with verteporfin (visudyne).

PURPOSE: To report a serious adverse reaction associated with verteporfin infusion. DESIGN: Observational case report. METHODS: Case report of a single individual undergoing photodynamic therapy (PDT) with verteporfin. RESULTS: A 77-year-old man with long-standing asymptomatic atrial fibrillation, but no known coronary artery disease experienced severe chest and neck pain, shortness of breath, and syncope while undergoing a fourth photodynamic therapy (PDT) treatment with verteporfin. This infusion had been preceded by three prior infusions; the first two were uneventful, and the third was associated with milder, but similar symptoms. Evaluation demonstrated that the chest pain was noncardiac in origin. CONCLUSION: As verteporfin continues to be used around the world, physicians must be alert to the possibility of serious adverse side effects associated with its use.

Aged↗

Localization of UvrA and effect of DNA damage on the chromosome of Bacillus subtilis.

We found that the nucleotide excision repair protein UvrA, which is involved in DNA damage recognition, localizes to the entire chromosome both before and after damage in living Bacillus subtilis cells. We suggest that the UvrA(2)B damage recognition complex is constantly scanning the genome, searching for lesions in the DNA. We also found that DNA damage induces a dramatic reconfiguration of the chromosome such that it no longer fills the entire cell as it does during normal growth. This reconfiguration is reversible after low doses of damage and is dependent on the damage-induced SOS response. We suggest that this reconfiguration of the chromosome after damage may be either a reflection of ongoing DNA repair or an active mechanism to protect the cell's genome. Similar observations have been made in Escherichia coli, indicating that the alteration of chromosome structure after DNA damage may be a widespread phenomenon.

Adenosine Triphosphatases↗

Evaluation of the potential acuity meter in predicting visual acuity after photodynamic therapy for choroidal neovascularization.

BACKGROUND AND OBJECTIVE: To evaluate the potential acuity meter in predicting visual acuity after photodynamic therapy of choroidal neovascular membranes caused by age-related macular degeneration. PATIENTS AND METHODS: Retrospective study of 55 eyes in 51 patients with subfoveal predominantly classic choroidal neovascularization due to age-related macular degeneration. Pre-photodynamic therapy Snellen visual acuity minus the visual acuity with the potential acuity meter was compared with the actual improvement in visual acuity. Significant improvement in visual acuity after photodynamic therapy was defined as a gain of more than 2 lines in Snellen visual acuity (0.2 logarithm of the minimal angle of resolution units). RESULTS: Eighteen (51.4%) of 35 eyes with a potential for improvement experienced an actual improvement in their Snellen visual acuity after photodynamic therapy (P < .001). All eyes lacking a potential for improvement failed to experience an actual improvement in visual acuity after photodynamic therapy. CONCLUSION: The eyes that demonstrated better visual acuity with the potential acuity meter in this study seemed more likely to experience an improvement in visual acuity after photodynamic therapy.

Aged↗