Biomedical subjects

Andrew W Eller

Publications and source records attributed to Andrew W Eller.

4 recordsLinked to original sources

PubMed2004

Age-related maculopathy: a genomewide scan with continued evidence of susceptibility loci within the 1q31, 10q26, and 17q25 regions.

Age-related maculopathy (ARM), or age-related macular degeneration, is one of the most common causes of visual impairment in the elderly population of developed nations. In a combined analysis of two previous genomewide scans that included 391 families, containing up to 452 affected sib pairs, we found linkage evidence in four regions: 1q31, 9p13, 10q26, and 17q25. We now have added a third set of families and have performed an integrated analysis incorporating 530 families and up to 736 affected sib pairs. Under three diagnostic models, we have conducted linkage analyses using parametric (heterogeneity LOD [HLOD] scores under an autosomal dominant model) and nonparametric (Sall statistic) methods. There is ongoing evidence of susceptibility loci within the 1q31, 10q26, and 17q25 regions. If we treat the third set of families as a replication set, then two regions (10q26 and 17q25) are replicated, with LOD scores >1.0. If we pool all our data together, then four regions (1q31, 2q14.3, 10q26, and 17q25) show HLOD or Sall scores > or =2.0. Within the 1q31 region, we observed an HLOD of 2.72 (genomewide P=.061) under our least stringent diagnostic model, whereas the 17q25 region contained a maximal HLOD of 3.53 (genomewide P=.007) under our intermediate diagnostic model. We have evaluated our results with respect to the findings from several new independent genomewide linkage studies and also have completed ordered subset analyses (OSAs) with apolipoprotein E alleles, smoking history, and age at onset as stratifying covariates. The OSAs generate the interesting hypothesis that the effect of smoking on the risk of ARM is accentuated by a gene in the 10q26 region--a region implicated by four other studies.

Chromosomes, Human, Pair 1↗

PubMed2003

Interactions of perfluorocarbon liquids and silicone oil as characterized by mass spectrometry.

BACKGROUND: Perfluorocarbon liquids (PFCL) are used extensively in complex vitreoretinal surgery, sometimes before the placement of silicone oil (SiO). We suspected that PFCL and SiO interact physically when in opposition, potentially making their removal more difficult. The nature of some of these interactions was explored using a mass spectrometric approach in in-vitro and in-vivo samples. METHODS: We incubated silicone oil (1,000 or 5,000 centistokes viscosity) and PFCL [perfluoro-n-octane (PFO) or perfluorotributylamine] together in vitro for 6 months and performed electron impact ionization mass spectrometry (EIMS) on the PFCL to characterize interactions between the liquid phases. Packaged samples of PFCL served as controls. We also examined in vivo samples of PFO which had been retained in human eyes for several months prior to surgical removal. RESULTS: Perfluorocarbon liquids packaged for surgical use all contain SiO in trace amounts, possibly as a manifestation of the processes used in their manufacture. Furthermore, all PFCLs incubated with SiO showed much more prominent contamination with SiO molecular fragments. PFCL was found in the SiO phase of eyes in which both liquids were present for extended periods of time. The EIMS analysis of in vivo samples suggested that proteins coat PFCL droplets, forming micelle-like structures. CONCLUSION: Medical-grade PFCLs contain small amounts of SiO, and PFCLs dissolve small amounts of oil into solution over time. Interactions between retained vitreous substitutes may have clinical relevance.

Drug Interactions↗

PubMedDate not supplied

Acute retinal necrosis.

Acute retinal necrosis (ARN) is an uncommon intraocular inflammatory syndrome characterized by severe and diffuse uveitis, retinal vasculitis, and retinal necrosis. It is typically described to occur in immunocompetent patients, but can also be found in immunocompromised subjects. Varicella-zoster virus (VZV), herpes simplex virus (HSV 1 and 2), cytomegalovirus (CMV), and Epstein-Barr virus (EBV) have been implicated in the etiology of ARN. The characteristic features of the disease include iridocyclitis, vitritis, retinal vasculitis, and retinal necrosis. Bilateral involvement occurs in two-thirds of the patients, frequently in the first six weeks, but sometimes months to years later. Retinal detachment occurs in 75% of the cases. The diagnosis of ARN is usually based in clinical features. The use of polymerase chain reaction (PCR) in aqueous humor samples is useful to identify the etiology of the disease. The treatment of ARN includes intravenous acyclovir, corticosteroids and aspirin. To prevent fellow eye involvement, intravenous acyclovir is followed by oral acyclovir for 14 weeks. Alternatives to acyclovir include ganciclovir, foscarnet, famcyclovir, brivudine, and valgancyclovir.

Antiviral Agents↗

PubMedDate not supplied

Non-mydriatic panoramic fundus imaging using a non-contact scanning laser-based system.

BACKGROUND AND OBJECTIVE: A non-contact scanning laser-based retinal imaging system produces a 200 degrees wide-field panoramic image of the fundus through the novel use of a large elliptical mirror. The authors investigated whether accurate diagnoses could be made from these images alone. PATIENTS AND METHODS: Images were obtained from both eyes of arbitrarily selected patients and were retrospectively reviewed by retinal specialists. Each physician made a diagnosis, suggested the follow-up interval, and determined whether any intervention was needed based solely on image review. Diabetic retinopathy was categorized as background retinopathy only, preproliferative retinopathy, maculopathy, and proliferative retinopathy. The results of the image review were then compared with the results of clinical examination, and the sensitivity and specificity of the review were calculated. RESULTS: The correct overall diagnosis was made by the two specialists in 87% and 77% of cases, respectively; the specificity and sensitivity each averaged 76%. Follow-up interval recommendations from image review matched those made on clinical examination in 86% of cases. Diabetic retinopathy was correctly identified as a general diagnosis with a sensitivity of 94% and the follow-up recommendations corresponded to the clinical recommendations in 82%. Sixty-two percent of the images were judged to be of good quality or better, with only 6.4% deemed unreadable. Iris color did not influence image quality. CONCLUSION: The non-contact scanning laser-based retinal imaging system provides images of sufficient resolution and clarity to make accurate general diagnoses in a high percentage of cases. Its use as a screening device for specific diseases is feasible and merits further study.

Diagnostic Imaging↗