484 research outputs found
Molecular Markers in Cutaneous Squamous Cell Carcinoma
Nonmelanoma skin carcinoma (NMSC) is the most frequent cancer in the USA with over 1.3 million new diagnoses a year; however due to an underappreciation of its associated mortality and growing incidence and its ability to be highly aggressive, the molecular mechanism is not well delineated. Whereas the molecular profiles of melanoma have been well characterized, those for cutaneous squamous cell carcinoma (cSCC) have trailed behind. This importance of the new staging paradigm is linked to the ability currently to better clinically cluster similar biologic behavior in order to risk-stratify lesions and patients. In this paper we discuss the trends in NMSC and the etiologies for the subset of NMSC with the most mortality, cutaneous SCC, as well as where the field stands in the discovery of a molecular profile. The molecular markers are highlighted to demonstrate the recent advances in cSCC
How shape-based anthropometry can complement traditional anthropometric techniques: a cross-sectional study
Abstract: Manual anthropometrics are used extensively in medical practice and epidemiological studies to assess an individual's health. However, traditional techniques reduce the complicated shape of human bodies to a series of simple size measurements and derived health indices, such as the body mass index (BMI), the waist-hip-ratio (WHR) and waist-by-height0.5 ratio (WHT.5R). Three-dimensional (3D) imaging systems capture detailed and accurate measures of external human form and have the potential to surpass traditional measures in health applications. The aim of this study was to investigate how shape measurement can complement existing anthropometric techniques in the assessment of human form. Geometric morphometric methods and principal components analysis were used to extract independent, scale-invariant features of torso shape from 3D scans of 43 male participants. Linear regression analyses were conducted to determine whether novel shape measures can complement anthropometric indices when estimating waist skinfold thickness measures. Anthropometric indices currently used in practice explained up to 52.2% of variance in waist skinfold thickness, while a combined regression model using WHT.5R and shape measures explained 76.5% of variation. Measures of body shape provide additional information regarding external human form and can complement traditional measures currently used in anthropometric practice to estimate central adiposity
Comparison Between the CASIA SS-1000 and Pentacam in Measuring Corneal Curvatures and Corneal Thickness Maps
PURPOSE: To compare the intra-device repeatability and inter-device reproducibility between two anterior segment imaging instruments, the CASIA SS-1000 (Tomey Corp., Nagoya, Japan) and Pentacam (OCULUS, Arlington, WA) in measuring anterior segment parameters.
METHODS: Single-center, prospective clinical trial. Participants ≥20 years of age were included. One eye was randomly selected, each imaged by three CASIA SS-1000 devices and three Pentacam devices by three different examiners. Each photographer operated a pair of devices, one CASIA SS-1000 and one Pentacam. The image order for each participant was determined by a random permutation table. Three images were taken from each device. A total of 18 images were taken for each eye. Ratios of the standard deviations, referenced as (CASIA/Pentacam), were calculated to compare the repeatability and reproducibility of the two imaging instruments.
RESULTS: In all, 66 participants with a mean age of 46.4 years (±21.7) were enrolled in the study. All repeatability ratios and intra-device variability were less than 1 (anterior corneal curvature: flat = 0.86, steep = 0.85; posterior corneal curvature: flat = 0.43, steep = 0.61; and map: thinnest = 0.22; central = 0.24, 2 mm = 0.26, 4 mm = 0.27, and 6 mm = 0.30). All reproducibility ratios, which measure the inter-device variability, were less than 1 (anterior corneal curvature: flat = 0.58, steep = 0.73; posterior corneal curvature: flat = 0.25, steep = 0.31; and pachymetry map: thinnest = 0.20; central = 0.20; 2 mm = 0.20; 4 mm = 0.19; and 6 mm = 0.22). A ratio of less than 1 indicates that the CASIA SS-1000 has more consistent measurements.
CONCLUSIONS: The CASIA SS-1000 was found to have better repeatability and reproducibility compared to the Pentacam for both corneal curvature and pachymetry maps. This greater consistency may require further study to determine whether the decreased variability can be translated into improved clinical results
Sources of Calcium at Connexin 36 Gap Junctions in the Retina
Synaptic plasticity is a fundamental feature of the CNS that controls the magnitude of signal transmission between communicating cells. Many electrical synapses exhibit substantial plasticity that modulates the degree of coupling within groups of neurons, alters the fidelity of signal transmission, or even reconfigures functional circuits. In several known examples, such plasticity depends on calcium and is associated with neuronal activity. Calcium-driven signaling is known to promote potentiation of electrical synapses in fish Mauthner cells, mammalian retinal AII amacrine cells, and inferior olive neurons, and to promote depression in thalamic reticular neurons. To measure local calcium dynamic
Determining Risk Factors That affect Progression in Patients With Nonproliferative Diabetic Retinopathy
PURPOSE: to determine risk factors that affect nonproliferative diabetic retinopathy (NPDR) progression and establish a predictive model to estimate the probability of and time to progression in NPDR.
RESULTS: Two hundred thirty patients were included. Initially, 65 eyes (28.3%) had no retinopathy; 73 (31.7%) mild NPDR; 60 (26.1%) moderate NPDR; and 32 (13.9%) severe NPDR. Patients were followed for a mean of 5.8 years (±2.0 years; range 2.1-9.4 years). 164 (71.3%) eyes progressed during the follow-up. Time-independent risk factors affecting progression rate were age (hazard ratio (HR) = 0.99,
CONCLUSION: HbA1c level is a significant modifiable risk factor in controlling the progression of DR. The proposed model could be used to predict the time and rate of progression based on an individual\u27s risk factors. A prospective multicenter study should be conducted to further validate our model
Defining the Role of Ab Externo Xen Gel Stent in Glaucomatous Eyes With Prior Failed Surgical Intervention
PURPOSE: To evaluate the safety and efficacy of Xen45 Gel stent (Xen; Allergan) in eyes that have failed prior surgical intervention, compared to traditional glaucoma drainage device (GDD) or continuous-wave cyclophotocoagulation (CPC). Since this population has low expected success rates with additional surgery, it is vital to compare to standard-of-care surgical options.
METHODS: Retrospective, single-center, case-control study of ab externo transconjunctival Xen shunt in eyes that have previously undergone trabeculectomy and/or GDD surgery. Postoperative data were collected for 18 months. Failure was defined as no light perception, additional glaucoma surgery required, or intraocular pressure (IOP) of \u3c 6 mmHg after 6 weeks postoperatively.
RESULTS: Eighteen Xen eyes and 36 control eyes matched on both glaucoma type and previous glaucoma surgeries were included. Seventy-two percent had primary open angle glaucoma, 11% uveitic, 6% primary angle closure, 6% pseudoexfoliation, and 6% pigmentary glaucoma. Fifty-six percent of eyes in each group had prior trabeculectomy, 28% of Xen and 31% of control eyes had prior GDD, and 17% of Xen and 14% of control eyes had both. Baseline medicated IOP was lower in the Xen group (21.8 ± 7.2) compared to controls (27.5 ± 9.4, P = 0.043). The cumulative failure rate at year 1 was 17% for Xen and 20% for controls (P = 0.57). Mean survival time was 14.1 (± 1.5) months and 11.4 (± 0.6) months for controls. There was no difference in minor complication rates between groups (P = 0.65), but the Xen group had a significantly lower rate of serious complications (P = 0.043) defined as vision threatening or requiring surgical intervention in the operating room. When censored for additional glaucoma procedures, there were no differences at year 1 in IOP, change in IOP, number of IOP-lowering medications, or number of medications reduced from baseline.
CONCLUSIONS: The Xen shunt provides a reasonable alternative to current standard of care, with a similar failure rate at year 1, with a noninferior IOP reduction compared to GDD and CPC, and a preferred safety profile
Prognosticators of Visual Acuity After Indirect Traumatic Optic Neuropathy
BACKGROUND: The purpose of this study is to determine whether there are radiographic and systemic clinical characteristics that can predict final visual outcomes in patients with indirect traumatic optic neuropathy (iTON).
METHODS: This study is a retrospective, multicenter case series of adult patients with iTON treated initially at large, urban, and/or academic trauma centers with follow-up at an affiliated ophthalmology clinic. In addition to detailed cranial computed tomography characteristics, demographics, systemic comorbidities, coinjuries, blood products administered, and intracranial pressure, along with other factors, were gathered. LogMAR visual acuity (VA) at the initial presentation to the hospital and up to 12 months follow-up was collected.
RESULTS: Twenty patients met inclusion criteria; 16 (80%) were men with a mean age of 40.9 years (±20.9). Mean initial VA was 1.61 logMAR (∼20/800, ± 0.95), and final VA was 1.31 logMAR (∼20/400, ± 1.06). Three patients (4 eyes) had no light perception (NLP) VA at presentation and remained NLP at final follow-up. Of the predictors analyzed, only the initial VA was found to be a significant predictor of visual outcome. The presence of orbital fractures, intraconal and/or extraconal hemorrhage, as well as systemic comorbidities, were not found to significantly affect visual outcome.
CONCLUSIONS: After evaluating multiple factors, initial VA was the only factor associated with visual prognosis in iTON. This knowledge may better enable clinicians to predict visual prognosis and set reasonable expectations with patients and families at the time of injury
Estimating Somatotype from a Single-camera 3D Body Scanning System
Somatotype is an approach to quantify body physique (shape and body composition). Somatotyping by manual measurement (the anthropometric method) or visual rating (the photoscopic method) needs technical expertise to minimize intra- and inter-observer errors. This study aims to develop machine learning models which enable automatic estimation of Heath-Carter somatotypes using a single-camera 3D scanning system. Single-camera 3D scanning was used to obtain 3D imaging data and computer vision techniques to extract features of body shape. Machine learning models were developed to predict participants' somatotypes from the extracted shape features. These predicted somatotypes were compared against manual measurement procedures. Data were collected from 46 participants and used as the training/validation set for model developing, whilst data collected from 17 participants were used as the test set for model evaluation. Evaluation tests showed that the 3D scanning methods enable accurate (mean error 0.8) and precise (test-retest root mean square error 0.8) somatotype predictions. This study shows that the 3D scanning methods could be used as an alternative to traditional somatotyping approaches after the current models improve with the large datasets
Postoperative Complications of True Dropless Cataract Surgery versus Standard Topical Drops
Purpose Compare postoperative outcomes in cataract surgery between eyes with standard drop regimen versus dropless protocol by residents.
Design Retrospective cohort study between April 1, 2018 and March 31, 2020.
Methods The study was performed at Lyndon B. Johnson General Hospital in Houston, Harris County, Texas. A total of 547 eyes (234 dropless vs. 313 standard) with phacoemulsification cataract surgery and minimum of 1-month follow-up with best-corrected visual acuity (BCVA) were included. Dropless received 40 mg sub-Tenon\u27s triamcinolone and intracameral moxifloxacin. Patients were followed at postoperative day 1 (POD1), week 1 (POW1), and month 1 (POM1). Postoperative rate of BCVA better than 20/40 (Good vision) and rate of complications were compared between groups.
Results Good vision on POM1 in dropless (77.8%) was noninferior to standard (75.1%, p = 0.80). Complication rate in dropless (28.6%) was noninferior to standard (24.0%, p = 0.13). Intraocular pressure (IOP) elevation on POD1 ( p = 0.041) and anterior chamber (AC) cells on POW1 and POM1 ( p \u3c 0.001) were more frequent in dropless. Mean spherical equivalent at POM1 was better in dropless (−0.37 D [±0.81 D]) compared with standard (−0.61D [±0.77 D], p = 0.001). Early posterior capsular opacification (early PCO) was more frequent in dropless ( p = 0.042).
Conclusions Postoperative rate of BCVA better than 20/40 and rate of postoperative complications were noninferior, although dropless had higher rates of AC inflammation, IOP elevation, and early PCO
The three-dimensional organization of telomeres in the nucleus of mammalian cells
BACKGROUND: The observation of multiple genetic markers in situ by optical microscopy and their relevance to the study of three-dimensional (3D) chromosomal organization in the nucleus have been greatly developed in the last decade. These methods are important in cancer research because cancer is characterized by multiple alterations that affect the modulation of gene expression and the stability of the genome. It is, therefore, essential to analyze the 3D genome organization of the interphase nucleus in both normal and cancer cells. RESULTS: We describe a novel approach to study the distribution of all telomeres inside the nucleus of mammalian cells throughout the cell cycle. It is based on 3D telomere fluorescence in situ hybridization followed by quantitative analysis that determines the telomeres' distribution in the nucleus throughout the cell cycle. This method enables us to determine, for the first time, that telomere organization is cell-cycle dependent, with assembly of telomeres into a telomeric disk in the G2 phase. In tumor cells, the 3D telomere organization is distorted and aggregates are formed. CONCLUSIONS: The results emphasize a non-random and dynamic 3D nuclear telomeric organization and its importance to genomic stability. Based on our findings, it appears possible to examine telomeric aggregates suggestive of genomic instability in individual interphase nuclei and tissues without the need to examine metaphases. Such new avenues of monitoring genomic instability could potentially impact on cancer biology, genetics, diagnostic innovations and surveillance of treatment response in medicine
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