Publications by authors named "Tom Chang"

Purpose: Our aim is to evaluate the sensitivity and specificity of Acuity 360 telemedicine system, as compared to in-person clinic examination, in identifying clinically significant eye disease. Acuity 360 is a combination of commercially available ocular imaging devices used together to provide a comprehensive evaluation of the structures and diseases of the eye.

Methods: Observational cross-sectional study of consecutively examined patients where 19 remote examiners analyzed 80 patients using Acuity 360 images.

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Purpose: To study the effects of anti-VEGF injections on the prevalence of ocular hypertension (OHT), sustained elevated intraocular pressure (SE-IOP), and primary open-angle glaucoma (POAG) with age-matched controls.

Methods: A retrospective case-control study was performed with neovascular age-related macular degeneration (AMD) or diabetic macular edema (DME) against a control group involving atrophic AMD or diabetic retinopathy (DR) without DME. Bevacizumab, ranibizumab, or a combination of both were used in the treatment group.

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Despite substantially decreasing the risk of hospitalization and death from COVID-19, COVID-19 booster vaccination rates remain low around the world. A key question for public health agencies is how to increase booster vaccination rates, particularly among high-risk groups. We conducted a large preregistered randomized controlled trial (with 57,893 study subjects) in a county health system in northern California to test the impact of personal reminder messages and small financial incentives of $25 on booster vaccination rates.

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Purpose: To study the effects of intravitreal injection (IVI) of anti-VEGF (vascular endothelial growth factor) agents on intraocular pressure (IOP) and find associations with acute pressure spikes.

Methods: This was a three-month, prospective study of patients receiving outpatient IVI of anti-VEGF agents for diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinal vein occlusion (RVO) at the Acuity Eye Group Medical Centers. IOP was measured pre- and post-injection at 10-minute intervals up to 50 minutes after injection with a handheld tonometer.

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Despite rapid initial uptake, COVID-19 vaccinations in the United States stalled within a few months of widespread rollout in 2021. In response, many state and local governments, employers and health systems used public health messaging, financial incentives and creative scheduling tools to increase vaccine uptake. Although these approaches drew on evidence from influenza and other vaccination efforts, they were largely untested in the context of SARS-CoV-2.

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Introduction: Socioeconomic differences may confound racial and ethnic differences in SARS-CoV-2 testing and COVID-19 outcomes.

Methods: A retrospective cohort study was conducted of racial/ethnic differences in SARS-CoV-2 testing and positive tests and COVID-19 hospitalizations and deaths among adults impaneled at a Northern California regional medical center and enrolled in the county Medicaid managed care plan (N=84,346) as of March 1, 2020. Logistic regressions adjusted for demographics, comorbidities, and neighborhood characteristics.

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Article Synopsis
  • Mycoplasma genitalium is an emerging sexually transmitted infection that can cause serious health issues like urethritis in men and pelvic inflammatory disease in women, with a prevalence similar to long-known pathogens like Chlamydia and Gonorrhea.
  • A study conducted at Tripler Army Medical Center tested 1,876 specimens over six months, revealing an overall M. genitalium prevalence of 8.8%, with higher rates in males (11.6%) compared to females (7.1%).
  • Coinfection with M. genitalium was observed in 18.3% of cases, primarily alongside Chlamydia trachomatis, highlighting the need for improved STI screening and awareness in military populations.
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Diesel exhaust particles (DEPs) are major constituents of air pollution and associated with numerous oxidative stress-induced human diseases. In vitro toxicity studies are useful for developing a better understanding of species-specific in vivo conditions. Conventional in vitro assessments based on oxidative biomarkers are destructive and inefficient.

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Purpose: To evaluate safety and successful use of a novel subretinal delivery system and suprachoroidal surgical approach and safety and activity of human umbilical tissue-derived cells (palucorcel) via a novel delivery system in patients with geographic atrophy (GA).

Design: Multicenter, open-label phase 2b study.

Participants: Participants were 55 to 90 years with GA secondary to age-related macular degeneration (AMD) and best-corrected visual acuity (BCVA) of 20/80 to 20/800.

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This paper studies differences in the effect of temperature on cognitive performance by gender in a large controlled lab experiment (N = 543). We study performance in math, verbal and cognitive reflection tasks and find that the effects of temperature vary significantly across men and women. At higher temperatures, women perform better on a math and verbal task while the reverse effect is observed for men.

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Jurisdictions that sanction medical or, more recently, recreational marijuana use often allow retail sales at dispensaries. Dispensaries are controversial as many believe they contribute to local crime. To assess this claim, we analyze the short-term mass closing of hundreds of medical marijuana dispensaries in Los Angeles.

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Purpose: To evaluate the safety and tolerability of and clinical response to a single, subretinal dose of human umbilical tissue-derived cells (palucorcel [CNTO-2476]) in the eyes of adults aged ≥50 years with bilateral geographic atrophy (GA) secondary to age-related macular degeneration (AMD).

Design: Phase 1/2a, multicenter, open-label, dose-escalation, fellow-eye-controlled study.

Methods: In the phase 1 portion, eyes were assigned to receive a single, subretinal dose of palucorcel (ranging from 6.

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We investigate the role of physician agency in determining health care supply and patient outcomes. We show that an increase in health care supply due to a change in private physician incentives has a theoretically ambiguous impact on patient welfare. The increase can reflect either induced demand for ineffective care or a reduction in prior rationing of effective care.

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Many patients who undergo general anesthesia and surgery experience cognitive dysfunction, particularly memory deficits that can persist for days to months. The mechanisms underlying this postoperative cognitive dysfunction in the adult brain remain poorly understood. Depression of brain function during anesthesia is attributed primarily to increased activity of γ-aminobutyric acid type A receptors (GABA(A)Rs), and it is assumed that once the anesthetic drug is eliminated, the activity of GABA(A)Rs rapidly returns to baseline and these receptors no longer impair memory.

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A variety of bacterial pathogenicity determinants, including the type VI secretion system and the virulence cassettes from Photorhabdus and Serratia, share an evolutionary origin with contractile-tailed myophages. The well-characterized Escherichia coli phage P2 provides an excellent system for studies related to these systems, as its protein composition appears to represent the "minimal" myophage tail. In this study, we used nuclear magnetic resonance (NMR) spectroscopy to determine the solution structure of gpX, a 68-residue tail baseplate protein.

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Objectives: To determine the impact of ranibizumab on driving status, driving ability perception, and having 20/40 vision or better in patients with choroidal neovascularization resulting from age-related macular degeneration (AMD).

Design: Phase III, multicenter, randomized clinical trials (Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular Age-Related Macular Degeneration [MARINA] and Anti-VEGF Antibody for the Treatment of Predominantly Classic Choroidal Neovascularization in Age-Related Macular Degeneration [ANCHOR]).

Participants: One thousand one hundred twenty-six patients with choroidal neovascularization resulting from AMD.

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Spinal muscular atrophy (SMA) is the leading genetic cause of infantile death and caused by the loss of functional Survival Motor Neuron 1 (SMN1). The remaining copy gene, SMN2, is unable to rescue from disease because the primary gene product lacks the final coding exon, exon 7, due to an alternative splicing event. While SMNΔ7 is a rapidly degraded protein, exon 7 is not specifically required in a sequence-specific manner to confer increased functionality to this truncated protein.

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Purpose Of Review: Stem cell therapy holds great promise for the treatment of retinal diseases. This review summarizes recent advances in stem cell biology, outlines ongoing clinical trials and details the obstacles that must be overcome for stem cell therapy to be a viable treatment for retinal disease.

Recent Findings: Stem cells can now be directed to specific retinal cell fates with high yields and acceptable purity for clinical trials.

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This report describes a 60-year-old patient with bilateral nephrolithiasis. A catalase-negative Staphylococcus epidermidis strain was recovered from both urine and blood cultures. Although rare, isolates of catalase-negative Staphylococcus spp.

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The rank-ordered multifractal analysis (ROMA), a recently developed technique that combines the ideas of parametric rank ordering and one-parameter scaling of monofractals, has the capabilities of deciphering the multifractal characteristics of intermittent fluctuations. The method allows one to understand the multifractal properties through rank-ordered scaling or nonscaling parametric variables. The idea of the ROMA technique is applied to analyze the multifractal characteristics of the auroral zone electric-field fluctuations observed by the SIERRA sounding rocket.

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Objective: To examine the effects of ranibizumab on the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) scores in neovascular age-related macular degeneration (AMD) according to whether the study eye was the better- or worse-seeing eye at baseline.

Design: Within 2 randomized, double-masked clinical trials (MARINA and ANCHOR), the NEI VFQ-25 was administered at 0, 1, 2, 3, 6, 9, 12, 18, and 24 months.

Participants: We included 646 MARINA and 379 ANCHOR patients.

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Purpose: To compare the effectiveness of three consecutive intravitreal injections of bevacizumab (Avastin) and ranibizumab (Lucentis) in patients with treatment-naïve neovascular age-related macular degeneration.

Methods: This is a retrospective comparative study of qualifying consecutively treated patients (n = 176) with new-onset subfoveal choroidal neovascularization presenting at 6 retina referral centers. Patients were treated with 3 consecutive monthly injections of ranibizumab (0.

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Objective: To compare patient-reported visual function in those with neovascular age-related macular degeneration treated with ranibizumab or verteporfin photodynamic therapy (PDT).

Design: Multicenter, double-masked, phase 3 trial (ANCHOR). Participants were randomized in a 1:1:1 ratio to receive 0.

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The hallmark of nonlinear complexity phenomena in magnetohydrodynamic and plasma turbulence as well as all natural sciences is the appearance of intermittent fluctuating events. We introduce here a unique procedure that is both physically explicable and quantitatively accurate in deciphering the multifractal characteristics of intermittency. The generic character of the procedure provides a natural connection between the suggested spectrum based on rank order and the idea of one-parameter scaling for monofractals.

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