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1.
Women Health ; 61(4): 381-392, 2021 04.
Article in English | MEDLINE | ID: mdl-33813998

ABSTRACT

Ovarian cancer is the seventh most common cancer among women worldwide. We assessed the effect of socioeconomic status on ovarian cancer incidence in Canada between 1992 and 2010. We linked data from the Canadian Cancer Registry (CCR), Canadian Census of Population (CCP), and National Household Survey (NHS) to measure socioeconomic inequalities in the incidence of ovarian cancer among Canadian women over the study period. The age-standardized relative and absolute concentration index (RC and AC, respectively) were calculated to quantify income- and education-related inequalities in the incidence of ovarian cancer in Canadian women during this period. Despite a slight increase in the crude incidence of ovarian cancer in Ontario, Quebec, New Brunswick, Newfoundland and Labrador & Prince Edward Island, and Canada as a whole, the incidence of ovarian cancer in Canada has mostly remained stable, between 13 and 15 new cases per 100,000 per year between 1992 and 2010. The estimated age-standardized RC and AC values for the study period did not indicate any statistically significant relationship between income or education status, and the incidence of ovarian cancer in Canada. Future work should be directed at seeking related risk factors other than socioeconomic status that may contribute to the incidence of this disease.


Subject(s)
Ovarian Neoplasms , Social Class , Canada/epidemiology , Female , Humans , Incidence , Ovarian Neoplasms/epidemiology , Socioeconomic Factors
2.
Proteomics ; 21(9): e2000121, 2021 05.
Article in English | MEDLINE | ID: mdl-33460282

ABSTRACT

Caloric restriction (CR) is an innovative therapy used in tumor tissue and tumor model studies to promote cell death and decrease cell viability. Caloric restriction mimetics (CRMs) are a class of drugs that induce CR and starvation conditions within a cell. When used simultaneously with other chemotherapy agents, the effects are synergistic and effective at promoting tumor cell death. In this review, we discuss CRMs and their potential as cancer therapeutics. Firstly, we establish an overview of CR and its impacts on healthy and tumor cells. CR and CRM drugs have shown to decrease age-related diseases and can act as an anti-cancer agent. As it can be challenging for an individual to diligently stick to a diet that would induce CR, CRMs are even more desirable. Then, we discuss the drug class by highlighting three CRMs: resveratrol, (-)-hydroxycitric acid, and rapamycin. These CRMs are commonly known for their dietary effects, but the underlying mechanisms that drive cellular metabolic and proteomic changes show promise as a cancer therapeutic. Lastly, we highlight the use of mass spectrometry and proteomic techniques on experiments utilizing CRM drugs to understand the cellular pathways impacted by this drug class, leading to a better understanding of the anti-cancer properties and potentials of CRM.


Subject(s)
Caloric Restriction , Proteomics , Mass Spectrometry , Sirolimus
3.
Alzheimers Dement ; 17(1): 103-111, 2021 01.
Article in English | MEDLINE | ID: mdl-33090722

ABSTRACT

In the last 20 years, research focused on developing retinal imaging as a source of potential biomarkers for Alzheimer's disease and other neurodegenerative diseases, has increased significantly. The Alzheimer's Association and the Alzheimer's & Dementia: Diagnosis, Assessment, Disease Monitoring editorial team (companion journal to Alzheimer's & Dementia) convened an interdisciplinary discussion in 2019 to identify a path to expedite the development of retinal biomarkers capable of identifying biological changes associated with AD, and for tracking progression of disease severity over time. As different retinal imaging modalities provide different types of structural and/or functional information, the discussion reflected on these modalities and their respective strengths and weaknesses. Discussion further focused on the importance of defining the context of use to help guide the development of retinal biomarkers. Moving from research to context of use, and ultimately to clinical evaluation, this article outlines ongoing retinal imaging research today in Alzheimer's and other brain diseases, including a discussion of future directions for this area of study.


Subject(s)
Alzheimer Disease/diagnostic imaging , Neurodegenerative Diseases/diagnostic imaging , Retina/diagnostic imaging , Aged , Aged, 80 and over , Biomarkers , Brain/diagnostic imaging , Humans , Middle Aged
4.
Transl Vis Sci Technol ; 9(2): 47, 2020 08.
Article in English | MEDLINE | ID: mdl-32879757

ABSTRACT

Purpose: To use machine learning in those with brain amyloid to predict thioflavin fluorescence (indicative of amyloid) of retinal deposits from their interactions with polarized light. Methods: We imaged 933 retinal deposits in 28 subjects with post mortem evidence of brain amyloid using thioflavin fluorescence and polarization sensitive microscopy. Means and standard deviations of 14 polarimetric properties were input to machine learning algorithms. Two oversampling strategies were applied to overcome data imbalance. Three machine learning algorithms: linear discriminant analysis, supporting vector machine, and random forest (RF) were trained to predict thioflavin positive deposits. For each method; accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve were computed. Results: For the polarimetric positive deposits, using 1 oversampling method, RF had the highest area under the receiver operating characteristic curve (0.986), which was not different from that with the second oversampling method. RF had 95% accuracy, 94% sensitivity, and 97% specificity. After including deposits with no polarimetric signals, polarimetry correctly predicted 93% of thioflavin positive deposits. Linear retardance and linear anisotropy were the dominant polarimetric properties in RF with 1 oversampling method, and no polarimetric properties were dominant in the second method. Conclusions: Thioflavin positivity of retinal amyloid deposits can be predicted from their images in polarized light. Polarimetry is a promising dye-free method of detecting amyloid deposits in ex vivo retinal tissue. Further testing is required for translation to live eye imaging. Translational Relevance: This dye-free method distinguishes retinal amyloid deposits, a promising biomarker of Alzheimer's disease, in human retinas imaged with polarimetry.


Subject(s)
Alzheimer Disease , Amyloidosis , Alzheimer Disease/diagnosis , Amyloid , Amyloidogenic Proteins , Humans , Plaque, Amyloid
5.
Langmuir ; 33(16): 3926-3933, 2017 04 25.
Article in English | MEDLINE | ID: mdl-28375634

ABSTRACT

Magnesium aluminum-layered double-hydroxide nanoparticles (LDH NPs) are promising drug-delivery vehicles for gene therapy, particularly for siRNA interference; however, the interactions between oligo-DNA and LDH surfaces have not been adequately elucidated. Through a mechanistic study, oligo-DNA initially appears to rapidly bind strongly to the LDH outer surfaces through interactions with their phosphate backbones via ligand exchange with OH- on Mg2+ centers and electrostatic forces with Al3+. These initial interactions might precede diffusion into interlayer spaces, and this knowledge can be used to design better gene therapy delivery systems.


Subject(s)
Aluminum Hydroxide/chemistry , Magnesium Hydroxide/chemistry , Nanoparticles/chemistry , Oligodeoxyribonucleotides/chemistry , Adsorption , Gene Transfer Techniques , Particle Size , Surface Properties
6.
Vision Res ; 132: 3-33, 2017 03.
Article in English | MEDLINE | ID: mdl-28212982

ABSTRACT

Adaptive optics is a relatively new field, yet it is spreading rapidly and allows new questions to be asked about how the visual system is organized. The editors of this feature issue have posed a series of question to scientists involved in using adaptive optics in vision science. The questions are focused on three main areas. In the first we investigate the use of adaptive optics for psychophysical measurements of visual system function and for improving the optics of the eye. In the second, we look at the applications and impact of adaptive optics on retinal imaging and its promise for basic and applied research. In the third, we explore how adaptive optics is being used to improve our understanding of the neurophysiology of the visual system.


Subject(s)
Ocular Physiological Phenomena , Optics and Photonics , Retina/physiology , Vision Disorders/rehabilitation , Visual Perception/physiology , Animals , Humans , Psychophysics , Vision Disorders/physiopathology , Vision, Ocular/physiology
7.
J Voice ; 31(2): 258.e1-258.e5, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27427162

ABSTRACT

OBJECTIVE: This study aimed to determine the influence of native language on the auditory-perceptual assessment of voice, as completed by Brazilian and Anglo-Canadian listeners using Brazilian vocal samples and the grade, roughness, breathiness, asthenia, strain (GRBAS) scale. STUDY DESIGN: This is an analytical, observational, comparative, and transversal study conducted at the Speech Language Pathology Department of the Federal University of Minas Gerais in Brazil, and at the Communication Sciences and Disorders Department of the University of Alberta in Canada. METHODS: The GRBAS scale, connected speech, and a sustained vowel were used in this study. The vocal samples were drawn randomly from a database of recorded speech of Brazilian adults, some with healthy voices and some with voice disorders. The database is housed at the Federal University of Minas Gerais. Forty-six samples of connected speech (recitation of days of the week), produced by 35 women and 11 men, and 46 samples of the sustained vowel /a/, produced by 37 women and 9 men, were used in this study. The listeners were divided into two groups of three speech therapists, according to nationality: Brazilian or Anglo-Canadian. The groups were matched according to the years of professional experience of participants. The weighted kappa was used to calculate the intra- and inter-rater agreements, with 95% confidence intervals, respectively. RESULTS: An analysis of the intra-rater agreement showed that Brazilians and Canadians had similar results in auditory-perceptual evaluation of sustained vowel and connected speech. The results of the inter-rater agreement of connected speech and sustained vowel indicated that Brazilians and Canadians had, respectively, moderate agreement on the overall severity (0.57 and 0.50), breathiness (0.45 and 0.45), and asthenia (0.50 and 0.46); poor correlation on roughness (0.19 and 0.007); and weak correlation on strain to connected speech (0.22), and moderate correlation to sustained vowel (0.50). CONCLUSION: In general, auditory-perceptual evaluation is not influenced by the native language on most dimensions of the perceptual parameters of the GRBAS scale.


Subject(s)
Phonetics , Speech Acoustics , Speech Perception , Voice Disorders/diagnosis , Voice Quality , Acoustics , Alberta , Brazil , Databases, Factual , Female , Humans , Judgment , Male , Observer Variation , Ovulation Prediction , Reproducibility of Results , Severity of Illness Index , Speech Intelligibility , Speech Production Measurement , Voice Disorders/physiopathology , Voice Disorders/psychology
8.
Invest Ophthalmol Vis Sci ; 56(11): 6339-43, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26517403

ABSTRACT

PURPOSE: Changes to retinal structure and function occur in individuals with diabetes before the onset of diabetic retinopathy. It is still unclear if these changes initially affect vascular or neural retina, or if particular retinal areas are more susceptible than others. This paper examines the distribution of cone photoreceptor density in the retina of adolescents with type 1 diabetes. METHODS: This cross-sectional prospective study includes 29 adolescents and young adults with type 1 diabetes and no diabetic retinopathy and 44 control participants recruited at the Hospital for Sick Children. Adaptive-optics enhanced retinal imaging of the cone photoreceptor mosaic was performed in four quadrants at an eccentricity of ∼7° from the fovea. After image registration and averaging, cone photoreceptors were counted and photoreceptor density was calculated. Analysis of variance with repeated measures was used to assess the differences in photoreceptor density between groups. RESULTS: Cone density was similar in both control participants and participants with diabetes. There was a small effect of retinal hemisphere; participants with diabetes did not show the expected radial asymmetry observed in control participants. CONCLUSIONS: Cone density in the parafoveal retina is not reduced in adolescents with type 1 diabetes.


Subject(s)
Cell Count , Diabetes Mellitus, Type 1/pathology , Retinal Cone Photoreceptor Cells/pathology , Adolescent , Adult , Case-Control Studies , Child , Cross-Sectional Studies , Female , Fundus Oculi , Humans , Male , Prospective Studies , Retinoscopy , Young Adult
9.
J Am Acad Audiol ; 25(4): 405-13, 2014 Apr.
Article in English | MEDLINE | ID: mdl-25126687

ABSTRACT

BACKGROUND: Computerized, home-based auditory-training programs could be attractive to cochlear implant (CI) recipients who cannot obtain direct intensive training services and also to busy clinicians who would like to enable CI recipients to benefit from these programs. However, it is difficult for either group to know which of the many programs available might best suit individual needs. PURPOSE: Selecting a computerized home-based program can be challenging because each offers different features. This article provides an overview of currently available programs to help clinicians and recipients choose one that is most suitable. DATA COLLECTION AND ANALYSIS: A narrative literature review and an advanced Google search of Web sites linked to auditory-training programs were conducted. This overview builds on and updates information from previous literature. RESULTS: Nine computerized, home-based auditory-training programs were identified for overview. Twenty-nine information items and features for each of the nine programs are presented, categorized by general product and purchase information, design features of the training paradigm, and auditory and communication targets. CONCLUSIONS: This article provides a descriptive overview of computerized, home-based auditory-training programs for the use of clinicians, CI recipients, researchers, and hearing aid users.


Subject(s)
Cochlear Implantation/rehabilitation , Internet , Patient Education as Topic , Adult , Auditory Threshold , Hearing Aids , Home Care Services , Humans , Speech Perception
10.
Ophthalmic Physiol Opt ; 33(3): 379-84, 2013 May.
Article in English | MEDLINE | ID: mdl-23662970

ABSTRACT

In the following point-counterpoint article, internationally-acclaimed myopia researchers were challenged to defend the two opposing sides of the topic defined by the title; their contributions, which appear in the order Point followed by Counterpoint, were peer-reviewed by both the editorial team and an external reviewer. Independently of the invited authors, the named member of the editorial team provided an Introduction and Summary, both of which were reviewed by the other members of the editorial team. By their nature, views expressed in each section of the Point-Counterpoint article are those of the author concerned and may not reflect the views of all of the authors.


Subject(s)
Contact Lenses, Hydrophilic , Cornea/pathology , Myopia/therapy , Orthokeratologic Procedures/methods , Retina/physiology , Visual Fields/physiology , Humans , Hyperopia/physiopathology , Myopia/physiopathology
11.
Invest Ophthalmol Vis Sci ; 54(1): 898-908, 2013 Jan 30.
Article in English | MEDLINE | ID: mdl-23221069

ABSTRACT

PURPOSE: To report phenotypic characteristics including macular cone photoreceptor morphology in KCNV2-related "cone dystrophy with supernormal rod electroretinogram" (CDSR). METHODS: Seven patients, aged 9 to 18 years at last visit, with characteristic full-field electroretinographic (ERG) features of CDSR were screened for mutations in the KCNV2 gene. All patients underwent detailed ophthalmological evaluation, which included distance and color vision testing, contrast sensitivity measurement, fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain-optical coherence tomography (SD-OCT). Follow-up visits were available in six cases. Rod photoreceptor function was assessed using a bright white flash ERG protocol (240 cd·s/m(2)). Macular cone photoreceptor morphology was assessed from 2° by 2° zonal images obtained using adaptive optics scanning laser ophthalmoscopy (AOSLO) in six cases. RESULTS: Pathogenic mutations in KCNV2 were identified in all seven cases. Best corrected vision was 20/125 or worse in all cases at the latest visit (20/125-20/400). Vision loss was progressive in two cases. Color vision and contrast sensitivity was abnormal in all cases. Retinal exam revealed minimal pigment epithelial changes at the fovea in four cases. A peri- or parafoveal ring of hyperfluorescence was the most common FAF abnormality noted (five cases). The SD-OCT showed outer retinal abnormalities in all cases. The rod photoreceptor maximal response was reduced but rod sensitivity was normal. AOSLO showed markedly reduced cone density in all six patients tested. CONCLUSIONS: Central vision parameters progressively worsen in CDSR. Structural retinal and lipofuscin accumulation abnormalities are commonly present. Macular cone photoreceptor mosaic is markedly disrupted early in the disease.


Subject(s)
Mosaicism , Potassium Channels, Voltage-Gated/genetics , Retinal Cone Photoreceptor Cells/physiology , Retinal Rod Photoreceptor Cells/physiology , Retinitis Pigmentosa/genetics , Retinitis Pigmentosa/pathology , Adolescent , Child , Codon, Terminator/genetics , Color Vision/genetics , Contrast Sensitivity/genetics , Disease Progression , Electroretinography , Female , Frameshift Mutation/genetics , Humans , Lipofuscin/metabolism , Male , Phenotype , Photic Stimulation/methods , Retinal Cone Photoreceptor Cells/pathology , Retinitis Pigmentosa/metabolism , Tomography, Optical Coherence
12.
Invest Ophthalmol Vis Sci ; 53(10): 6245-53, 2012 Sep 14.
Article in English | MEDLINE | ID: mdl-22893678

ABSTRACT

PURPOSE: To measure the diurnal variation of spherical equivalent refractive error (mean ocular refraction or MOR) and to investigate factors contributing to it in chick, an important animal myopia model. METHODS: Nine chicks developed naturally on a 14-hour light/10-hour dark cycle. Optical axial length (OAL) and Hartmann-Shack wavefront error (HSWE) measurements, including pupil size, were taken starting on day 7, at eight times during the following 32 hours. MOR was calculated for a constant pupil size from HSWE measurements. RESULTS: MOR, OAL, and pupil size showed significant diurnal variation (P < 0.0001). Most eyes showed significant sinusoidal variations in MOR and in pupil size with periods close to 24 hours. On average, MOR oscillated ±0.84 diopters. OAL varied with a period not different from 12 hours. Diurnally varying MOR and OAL were correlated (P = 0.0003, R² = 0.62). However, as previously reported, the variation in OAL did not account for the variation in MOR. From these results, we derived the diurnal variation in ocular power necessary to give the measured MOR variation. CONCLUSIONS: We confirmed a diurnal variation in OAL and found diurnal variations in pupil size and MOR. Although changes in OAL explain the MOR previously observed in response to lenses and diffusers, they do not completely account for the observed diurnal variation of MOR nor for the reduction in hyperopia during normal development. We infer that the diurnal variation in MOR and normal emmetropization both result from small differences in the relative changes of OAL and ocular power.


Subject(s)
Axial Length, Eye/physiopathology , Circadian Rhythm/physiology , Myopia/physiopathology , Refractive Errors/physiopathology , Analysis of Variance , Animals , Chickens , Disease Models, Animal , Female , Male , Pupil/physiology , Refraction, Ocular/physiology
13.
Optom Vis Sci ; 89(5): 644-51, 2012 May.
Article in English | MEDLINE | ID: mdl-22504326

ABSTRACT

PURPOSE: To demonstrate the feasibility of in vivo measurements of cones and their distributions as a function of normal growth without adaptive optics (AO) and also discuss the potential advantages and disadvantages of AO imaging in the chick, an animal model of myopia. METHODS: Chicks were obtained on the day of hatching. Axial length and retinoscopy measurements were performed on days 0 and 14. Chicks were imaged on the day of hatching and 14 days later in a custom-built confocal scanning laser ophthalmoscope. Angular densities, linear cone spacings, and cone packing arrangements were determined. RESULTS: Four subarrays of hexagonally packed cones were identified on both days and, from their angular spacings, appear to correspond to different cone types. There were no significant changes in angular cone density with growth and linear spacings of cones increased with growth. This is true for both overall densities and those of the cone subtypes. There was no change in the percent of hexagonally packed cones with growth. CONCLUSIONS: Cones can be imaged longitudinally in vivo in the awake chick. The packing arrangement of cones is 40% hexagonally packed. Although AO is not necessary to visualize the cones, including the subarrays of like cones, some closely spaced cones of different types may not be resolved. Most importantly, there is a need to use a larger pupil with growth to maintain the same linear resolution in the larger eye. Novel longitudinal imaging techniques and methods in animal models are shown here to give insights into normal development and, in future, will give insights into visual disorders and diseases, including myopia.


Subject(s)
Myopia/diagnosis , Retinal Cone Photoreceptor Cells/cytology , Retinoscopy/methods , Animals , Cell Count , Chickens , Disease Models, Animal , Disease Progression , Feasibility Studies , Severity of Illness Index
14.
J Obstet Gynaecol Can ; 32(12): 1140-1146, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21176325

ABSTRACT

The Canadian Perinatal Surveillance System has provided a comprehensive review of maternal mortality and severe maternal morbidity in Canada, and has identified several important limitations to existing national maternal data collection systems, including variability in the detail and quality of mortality data. The Canadian Perinatal Surveillance System report recommended the establishment of an ongoing national review and reporting system, as well as consistency in definitions and classifications of maternal mortality and severe maternal morbidity, in order to enhance surveillance of maternal mortality and severe maternal morbidity. Using review articles and studies that examined maternal mortality in general as opposed to maternal mortality associated with particular management strategies or conditions, maternal mortality and severe morbidity classifications, terminology, and comparative statistics were reviewed and employed to evaluate deficiencies in past and current methods of data collection and to seek solutions to address the need for enhanced and consistent national surveillance of maternal mortality and severe maternal morbidity in Canada.


Subject(s)
Population Surveillance/methods , Pregnancy Complications/epidemiology , Pregnancy Complications/mortality , Canada/epidemiology , Female , Humans , Maternal Mortality , Pregnancy , Pregnancy Complications/classification
15.
J Vis ; 9(6): 12.1-20, 2009 Jun 24.
Article in English | MEDLINE | ID: mdl-19761303

ABSTRACT

In the simplest model of eye growth, the ocular optics uniformly scale upwards, as do monochromatic higher-order aberrations (HOA) and linear blur on the retina. However, measured HOA remain constant or decrease with growth in some species. A new model, which holds HOA and the associated linear blur on the retina constant, was used to predict changes in HOA and resulting image quality on the retina during growth, in each of chick, monkey, and human. Models used rates of growth in each of the three species. Angular optical quality on the retina due to HOA, and its metrics improved, in contrast to the constancy predicted by uniform scaling. The model with constant linear HOA blur predicts well the improvement in human optical quality between infant and adult. Overall, in chick and monkey, angular blur improves at a rate faster than that predicted by the constant linear blur model, implying that linear retinal blur due to HOA decreases with age. On the other hand, in chick, angular blur due to third-order aberrations decreased at a rate predicted by the constant linear blur model. Growth changes in retinal blur due to HOA are species dependent but can be better understood by comparison with the new model predictions.


Subject(s)
Eye/growth & development , Ocular Physiological Phenomena , Retina/physiology , Aberrometry , Adult , Aging/physiology , Animals , Chickens , Fixation, Ocular , Haplorhini , Humans , Infant , Linear Models , Models, Biological , Myopia/physiopathology , Optics and Photonics , Refraction, Ocular/physiology
16.
Ophthalmic Physiol Opt ; 29(3): 247-55, 2009 May.
Article in English | MEDLINE | ID: mdl-19422555

ABSTRACT

The degree of polarization (DOP) of the light reflected from the optic nerve head has been assessed by means of a polarimetric scanning laser ophthalmoscope as a function of the age of the participants. Four fundus images corresponding to independent polarization states in the recording pathway were used to compute the spatially-resolved DOP. This was not uniform across the optic nerve head and depended on both the location and the participant's age. Along a peripapillary annulus the DOP followed a double-peak pattern. Moreover, the values along this annulus decreased significantly with increasing age. This depolarization appears to originate in part in the retinal nerve fiber layer. Detailed age-dependent knowledge of the ocular depolarization properties may help to improve clinical diagnosis of the retinal nerve fiber layer.


Subject(s)
Image Enhancement/methods , Microscopy, Polarization/methods , Optic Disk/physiology , Optic Nerve Diseases/diagnosis , Adult , Age Factors , Humans , Middle Aged , Models, Statistical , Young Adult
17.
J Leukoc Biol ; 82(2): 311-9, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17456802

ABSTRACT

Elevated mucosal IL-12/23p40 and IFN-gamma accompany early inflammation in IL-10-deficient (IL-10(-/-)) mice and then later decline while inflammation persists. This report addresses whether this cytokine profile reflects disease progression or inherent, age-related changes in mucosal immunity. IL-10(-/-) and wild-type (WT) mice were maintained in an ultrabarrier facility or transferred to conventional housing at 3, 12, or 30 weeks of age. Weight, stool changes, and histologic features were followed. Lamina propria mononuclear cells were cultured for cytokine analysis by ELISA. Ultrabarrier-housed IL-10(-/-) mice are statistically indistinguishable from WT mice by weight, disease activity index, and histologic inflammation. IL-10(-/-) mice but not WT, transferred at 3 weeks, develop colitis gradually, reaching a significant, sustained maximum by 15 weeks of age. Transfer at 12 weeks induces rapid disease onset in both strains, maximal at 15 weeks of age. Inflammation persists in IL-10(-/-), and WT recover. IL-10(-/-) and WT mice transferred at 30 weeks demonstrate transient diarrhea and weight loss but no chronic inflammation. Probiotics delay symptom onset only in the 12-week-old group. IFN-gamma production from ultrabarrier-housed IL-10(-/-) mice is elevated at 12 weeks of age, and older animals have decreased IFN-gamma and increased IL-4. IL-10 is important for suppressing inflammation after transfer at 3 weeks of age and limiting inflammation after transfer at 12 weeks but has little influence at 30 weeks of age. Colitis onset, progression, and response to probiotic therapy vary with immune system age, suggesting that a distinct, Th1-driven, age-dependent cytokine profile may contribute to increased colitis susceptibility in otherwise healthy mice.


Subject(s)
Aging/immunology , Colitis/immunology , Interleukin-10/deficiency , Intestinal Mucosa/immunology , Monocytes/cytology , Animals , Cells, Cultured , Colitis/metabolism , Disease Susceptibility , Enzyme-Linked Immunosorbent Assay , Inflammation/metabolism , Inflammation/pathology , Interferon-gamma/biosynthesis , Interferon-gamma/immunology , Interleukin-10/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Mucous Membrane/cytology
18.
J Opt Soc Am A Opt Image Sci Vis ; 24(5): 1284-95, 2007 May.
Article in English | MEDLINE | ID: mdl-17429474

ABSTRACT

We quantify the effects on scanning laser ophthalmoscope image quality of controlled amounts of scattered light, confocal pinhole diameter, and age. Optical volumes through the optic nerve head were recorded for a range of pinhole sizes in 12 subjects (19-64 years). The usefulness of various overall metrics in quantifying the changes in fundus image quality is assessed. For registered and averaged images, we calculated signal-to-noise ratio, entropy, and acutance. Entropy was best able to distinguish differing image quality. The optimum confocal pinhole diameter was found to be 50 microm (on the retina), providing improved axial resolution and image quality under all conditions.


Subject(s)
Algorithms , Image Enhancement/instrumentation , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Microscopy, Confocal/instrumentation , Ophthalmoscopes , Adult , Aged , Equipment Design , Equipment Failure Analysis , Female , Humans , Light , Male , Microscopy, Confocal/methods , Middle Aged , Reproducibility of Results , Scattering, Radiation , Sensitivity and Specificity
19.
J Opt Soc Am A Opt Image Sci Vis ; 24(5): 1337-48, 2007 May.
Article in English | MEDLINE | ID: mdl-17429479

ABSTRACT

We present a polarimetric technique to improve fundus images that notably simplifies and extends a previous procedure [Opt. Lett.27, 830 (2002)]. A generator of varying polarization states was incorporated into the illumination path of a confocal scanning laser ophthalmoscope. A series of four images, corresponding to independent incoming polarization states, were recorded. From these images, the spatially resolved elements of the top row of the Mueller matrix were computed. From these elements, images with the highest and lowest quality (according to different image quality metrics) were constructed, some of which provided improved visualization of fundus structures of clinical importance (vessels and optic nerve head). The metric values were better for these constructed images than for the initially recorded images and better than averaged images. Entropy is the metric that is most sensitive to differences in the image quality. Improved visualization of features could aid in the detection, localization, and tracking of ocular disease and may be applicable in other biomedical imaging.


Subject(s)
Image Enhancement/instrumentation , Image Enhancement/methods , Image Interpretation, Computer-Assisted/instrumentation , Image Interpretation, Computer-Assisted/methods , Microscopy, Confocal/instrumentation , Microscopy, Polarization/instrumentation , Retinoscopes , Equipment Design , Equipment Failure Analysis , Humans , Microscopy, Confocal/methods , Microscopy, Polarization/methods , Reproducibility of Results , Sensitivity and Specificity
20.
Optom Vis Sci ; 83(9): 649-56, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16971843

ABSTRACT

PURPOSE: In this initial study, we model the impact of crystalline lens movement and tilt, which we postulate are a potential consequence of scleral expansion surgery (SES). We demonstrate the possibility that these lead to an improvement in near vision with no concurrent restoration of lens accommodative function. With the implantation of scleral expansion bands (SEB), Schachar predicts an increase in the amplitude of accommodation not observed objectively. We postulate that the SEB implants cause the crystalline lens to be shifted forward and become misaligned. Using mathematical models of the optics of the human eye, we assess the effects of our postulate on the power of the eye, the depth of field, optical aberrations, and the appearance of the horizontal retinoscopic reflex. METHODS: Using anatomically based models of the human eye, the postulated effects of SES are theoretically modeled and optically analyzed in Code V for unintentional lens anterior movement, tilts, and decentrations of up to 1 mm, +/- 3 degrees , and +/- 0.3mm, respectively. The transverse aberrations are calculated before and after SES. Because it has been reported that the appearance of the retinoscopic reflex is consistent with the presence of excess aberrations, we also predict the appearance of the one-dimensional retinoscopic reflex for our models. The change in refractive error is also determined. RESULTS.: Unintentional lens shift, tilt, and decentration, as might occur as a result of SES surgery, would result in an increase in the total power of the eye along with an increase in asymmetric aberrations and little change in symmetric aberrations. The calculated appearances of the retinoscopic reflexes pre- and postsurgery are consistent with observations in the literature. CONCLUSIONS: Scleral expansion surgery could produce an improvement in near vision through an unintentional anterior displacement of the crystalline lens in combination with excess tilts and decentrations rather than as a result of a restoration of lens accommodation. There is a need for measurements and further analysis of the optical and visual properties of SES patients postsurgery.


Subject(s)
Accommodation, Ocular/physiology , Presbyopia/surgery , Reflex/physiology , Retina/physiopathology , Retinoscopy , Sclera/surgery , Tissue Expansion/methods , Adolescent , Adult , Humans , Lens, Crystalline/physiopathology , Models, Theoretical , Presbyopia/physiopathology , Treatment Outcome
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