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Blindness
Kinds of Blindness Terms modified by Blindness Selected AbstractsSPIRITUAL BLINDNESS, SELF-DECEPTION AND MORALLY CULPABLE NONBELIEFTHE HEYTHROP JOURNAL, Issue 4 2007KEVIN KINGHORN First page of article [source] Blindness following a diabetic foot infection: a variant to the ,eye,foot syndrome'?DIABETIC MEDICINE, Issue 7 2000K. C. J. Yuen SUMMARY Aims The ,eye,foot syndrome' was initially described by Walsh et,al. to highlight the important association of foot lesions in patients with diabetic retinopathy. We present a case of a 58-year-old patient with Type 2 diabetes mellitus who developed blindness following endogenous staphylococcal endophthalmitis from an infected foot ulcer. Results Our case describes the link between the eye and the foot but is somewhat different to the association as described by Walsh et,al. Endogenous endophthalmitis is rare with diabetic patients being especially at risk, and we report the first case of endogenous staphylococcal endophthalmitis related to a diabetic foot lesion. Conclusions Our case illustrates several important issues in the management of diabetic patients admitted to hospital with infection; the need to thoroughly examine the feet to ascertain any foot lesions and any underlying peripheral vascular disease or peripheral neuropathy, to treat aggressively any infected foot lesions to prevent serious complications of septicaemia and to consider rare conditions like endogenous endophthalmitis in any diabetic patient presenting with acute visual impairment and septicaemia. [source] Blindness and bulimia nervosa: A description of a case report and its treatmentINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 3 2006Fernando Fernández-Aranda PhD Abstract Objective Blindness has rarely been described in the eating disorder (ED) literature. In case reports in which this condition has been reported before an ED, it was concluded that visual body image was not essential for the development of the ED. This is the first report in which bulimia nervosa (BN) and its treatment in a blind woman were described. Method We report a single diagnosed and treated case of BN in a blind, 47-year-old Spanish woman. This case presented as its main characteristics the late onset of the ED, restrictive dieting, binging, and consequent purging behavior characterized by vomiting and great difficulties of coping with stress. From the beginning, the woman's body image was not essential. The treatment consisted of 21 individual outpatient sessions, which followed a non,symptom-oriented cognitive-behavioral approach, in which problem solving and stress management strategies were employed. Results Before, after the treatment, and at the 6-month and 1-year follow-up, the clinical evolution of the patient was assessed. Conclusion Although a few descriptions of single case reports on blindness in individuals with anorexia nervosa (AN) have already been reported in the literature, to the authors' knowledge, this is the first reported case in which this condition and its treatment have specifically been reported in an individual with BN. © 2006 by Wiley Periodicals, Inc., Int J Eat Disord, 2006 [source] Blindness to alternative scenarios in evidence evaluationJOURNAL OF INVESTIGATIVE PSYCHOLOGY AND OFFENDER PROFILING, Issue 2 2010Eric Rassin Abstract In order to prevent miscarriages of justice, police, prosecution, and judges must remain open to alternative scenarios in which the suspect is in fact innocent. In recent years, however, several studies have delivered results suggesting that open-mindedness is not always standard in criminal procedures. For example, Ask and Granhag (2005) found that police officers' estimation of the incriminating power of investigation findings was not affected by knowledge of an alternative suspect. The current first study replicated these findings in a mixed sample of police officers, district attorneys, and judges. In Study 2, this blindness to alternative scenarios did not emerge in a sample of university students. However, the estimation of the incriminating power of the evidence and the willingness to convict the primary suspect were predicted with the participants' confirmation proneness. Copyright © 2010 John Wiley & Sons, Ltd. [source] Effects of Colour BlindnessOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2004R. V. Abadi Professor No abstract is available for this article. [source] Life is sweet in Fiji: the availability of diabetes healthcare and health education, and diabetes awareness amongst diabetic patients in FijiPRACTICAL DIABETES INTERNATIONAL (INCORPORATING CARDIABETES), Issue 6 2002Jay Kuruvatti BSc, MB ChB Pre-registration House Officer Abstract During an elective visit to Fiji we assessed the knowledge of diabetes possessed by patients who attended the hospital Diabetic Clinic in Lautoka. All the patients interviewed had type 2 diabetes and 15.4% were treated with insulin, 80.8% with oral therapy and 3.8% with diet alone. Blindness was the commonest complication known to patients but almost a quarter could not describe any diabetic complication. All patients had seen a hospital doctor regarding their diabetes; 17.9% also saw a private general practitioner, 80.8% had seen the diabetes nurse, 60.8% a dietician, and 57.7% a chiropodist. When asked about causative factors 12.8% thought diabetes was caused by overeating, 12.8% thought it was due to too much sugar in the diet, and the remaining 60.3% did not know. The methods by which the ever-increasing financial burden of diabetes in Fiji can be reduced are discussed. We feel that the prevention of diabetes and the early detection of complications would be the most cost-effective methods to improve overall diabetes care in Fiji. However, the whole diabetes care service in Fiji is constrained by the poor economic state of the country and the low profile of diabetes in the healthcare plans of the country. Copyright © 2002 John Wiley & Sons, Ltd. [source] Lies in a Time of Threat: Betrayal Blindness and the 2004 U.S. Presidential ElectionANALYSES OF SOCIAL ISSUES & PUBLIC POLICY, Issue 1 2005Eileen L. Zurbriggen Exit polls from the 2004 U.S. presidential election indicated overwhelming support for President Bush among voters who said they valued honesty, even though the Bush administration had been sharply criticized for deceiving the public, especially concerning the reasons for invading Iraq. A psychological theory recently developed to help explain memory loss in trauma survivors sheds light on this paradox. Betrayal Trauma Theory (Freyd, 1996) states that memory impairment is greatest when a victim is dependent on the perpetrator. The theory also predicts who will be "blind" to signs of deception,those who are emotionally or financially dependent on the person who is lying. Although every American is dependent on the U.S. President to some extent, religious conservatives may be more psychologically dependent than others. Because they believe their core values are under attack, they depend on powerful leaders such as President Bush to defend these values. This psychological dependence may make it difficult for them to notice the administration's deceptions. [source] Blindness due to angioid streaks in congenital dyserythropoietic anaemia type IBRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2006Emily Roberts No abstract is available for this article. [source] Mathematical analysis of the cone ERG photopic hill: Clinical applicationsACTA OPHTHALMOLOGICA, Issue 2007P LACHAPELLE Purpose: With brighter stimuli, the photopic ERG b-wave increases to a maximal value and then decreases to a plateau, a feature known as the Photopic Hill (PH). Recently, a mathematical model combining a Gaussian (GF) and a Logistic Growth (LGF) functions was developed to fit the PH (Hamilton et al., Vision Research, in press). We examined if this equation could help us sort out selected retinopathies. Methods: We compared PHs (background: 30 cd.m-2; intensities: -0.8 to 2.84 log cd.sec.m-2) obtained from normals (N=40) and patients (N=20) affected with Congenital Stationary Night Blindness (CSNB), Congenital Postreceptoral Cone Pathway Anomaly (CPCPA) and Retinitis Pigmentosa (RP) with the GL ratio [GL= Gb / (Gb+Vbmax)] were Gb and Vbmax represent the amplitude of the Gaussian and logistic (Vbmax) functions respectively. Results: The normal GL ratio is 0.60 ± 0.08 (mean ± 1SD) compared to ,1.0 in CSNB (almost pure GF) and 0.32±0.08 in CPCP [reduced GF (p<.05) and normal LF (p>.05)] patients. Six of the 8 RP patients had a GL ratio above 0.5 (mean GL= 0.70 ± 0.19) and 2 below (0.28 and 0.41). Of interest, while in some retinopathies, a decline in Gb and Vbmax occurred with disease progression (longitudinal and transversal comparisons), it did not always modify the GL ratio. Conclusions: Human PH can be dissected into two distinct and concomitant phenomena each represented by its own equation. Altghough the retinal origin of the GF and LGF awaits to be confirmed, use of this mathematical approach appears to add valuable information that will further refine the diagnosis of retinal disorders affecting the photopic (cone) pathway. Supported by CIHR and Réseau Vision. [source] Blindness and ophthalmoplegia complicating facial cellulitisCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 3 2010A. Caudron No abstract is available for this article. [source] Causes of blindness among hospital outpatients in EcuadorCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 2 2006Helene Cass MB BS MPH Abstract Background:, There is a lack of published information on the causes of blindness in Ecuador and the Latin American region in general. This study is designed to enumerate the proportions of ocular conditions contributing to blindness in an outpatient population of an ophthalmology hospital in the coastal region of Ecuador. Methods:, All cases presenting to an ophthalmology outpatient clinic over a 3-week period during September 2004 were reviewed (n = 802). Visual acuity was measured using a Snellen acuity chart and those who met the criteria for blindness were included in the study (n = 118). Blindness was defined under the World Health Organization protocol as visual acuity of <3/60. Both unilateral and bilateral blindness were included in the study. The diagnosis of ocular pathology contributing to blindness was recorded. Results:, Among those considered to have unilateral blindness (n = 88), cataract was the most common cause (43%). This was followed by corneal pathologies (17%) and glaucoma (15%). Among those considered to have bilateral blindness (n = 30), refraction was the most common cause (37%), followed by cataract (23%) and glaucoma (17%). Conclusion:, The major causes of blindness found in this study reflected those in estimated data for the region. More studies are needed to improve the quality and quantity of epidemiological data on blindness in Ecuador and Latin America. Many obstacles to successful implementation of prevention of blindness programmes in South America still need to be overcome. [source] Blindness and poverty: a tragic combinationCLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 6 2007Brien A Holden OAM DSc PhD BAppSc LOSc FAAO FVCO DCLP DSc No abstract is available for this article. [source] Dexamethasone alters F-actin architecture and promotes cross-linked actin network formation in human trabecular meshwork tissueCYTOSKELETON, Issue 2 2005Abbot F. Clark Abstract Elevated intraocular pressure is an important risk factor for the development of glaucoma, a leading cause of irreversible blindness. This ocular hypertension is due to increased hydrodynamic resistance to the drainage of aqueous humor through specialized outflow tissues, including the trabecular meshwork (TM) and the endothelial lining of Schlemm's canal. We know that glucocorticoid therapy can cause increased outflow resistance and glaucoma in susceptible individuals, that the cytoskeleton helps regulate aqueous outflow resistance, and that glucocorticoid treatment alters the actin cytoskeleton of cultured TM cells. Our purpose was to characterize the actin cytoskeleton of cells in outflow pathway tissues in situ, to characterize changes in the cytoskeleton due to dexamethasone treatment in situ, and to compare these with changes observed in cell culture. Human ocular anterior segments were perfused with or without 10,7 M dexamethasone, and F-actin architecture was investigated by confocal laser scanning microscopy. We found that outflow pathway cells contained stress fibers, peripheral actin staining, and occasional actin "tangles." Dexamethasone treatment caused elevated IOP in several eyes and increased overall actin staining, with more actin tangles and the formation of cross-linked actin networks (CLANs). The actin architecture in TM tissues was remarkably similar to that seen in cultured TM cells. Although CLANs have been reported previously in cultured cells, this is the first report of CLANs in tissue. These cytoskeletal changes may be associated with increased aqueous humor outflow resistance after ocular glucocorticoid treatment. Cell Motil. Cytoskeleton 60:83,95, 2005. © 2004 Wiley-Liss, Inc. [source] Cerebral palsy in siblings caused by compound heterozygous mutations in the gene encoding protein CDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 5 2010CHOONG YI FONG We report two sisters with extensive bilateral periventricular haemorrhagic infarction (PVHI) causing cerebral palsy (CP). The older sister presented at 20 months with cortical visual blindness, spastic diplegia, and purpura fulminans. The younger sister presented aged 3 days old with apnoeas and multifocal seizures. She subsequently had global developmental delay, cortical visual blindness, spastic quadriplegia, epilepsy, and purpura fulminans at age 2 years. Neuroimaging of both siblings showed bilateral PVHI consistent with bilateral cerebral intramedullary venous thrombosis occurring at under 28 weeks' gestation for the older sister and around time of birth for the younger sister. At latest follow-up, the older sister (13y) has spastic diplegia at Gross Motor Function Classification System (GMFCS) level II, and the younger sister (10y) has spastic quadriplegia at GMFCS level IV. Both sisters showed partial quantitative reduction in plasma protein C antigen and severe qualitative reduction in plasma protein C anticoagulant activity. They were heterozygous for two independent mutations in the protein C gene (PROC). There was no other risk factor for CP. To our knowledge, this is the first family reported with compound heterozygous PROC mutations as the likely genetic cause of familial CP. This report adds to the list of known monogenic causes of CP. [source] The development of change blindness: children's attentional priorities whilst viewing naturalistic scenesDEVELOPMENTAL SCIENCE, Issue 3 2009S. Fletcher-Watson Change blindness describes the surprising difficulty of detecting large changes in visual scenes when changes occur during a visual disruption. In order to study the developmental course of this phenomenon, a modified version of the flicker paradigm, based on Rensink, O'Regan & Clark (1997), was given to three groups of children aged 6,12 years and to a group of adults. This paradigm tested the ability to detect single colour, presence/absence and location changes of both high and low semantic importance in a complex scene. Semantically important changes were detected more quickly and accurately than less semantically important changes, by all age groups, indicating that children had the same attentional priorities as adults. Older children achieved more efficient and accurate detection of changes than younger children and reached almost adult level at 10,12 years old. These improvements parallel age-related developments in attention and visual perception. [source] Vascular endothelial growth factor and diabetic retinopathy: pathophysiological mechanisms and treatment perspectivesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2003Ruth B. Caldwell Abstract Retinal neovascularization and macular edema are central features of diabetic retinopathy, the major cause of blindness in the developed world. Current treatments are limited in their efficacy and are associated with significant adverse effects. Characterization of the molecular and cellular processes involved in vascular growth and permeability has led to the recognition that the angiogenic growth factor and vascular permeability factor vascular endothelial growth factor (VEGF) plays a pivotal role in the retinal microvascular complications of diabetes. Therefore, VEGF represents an exciting target for therapeutic intervention in diabetic retinopathy. This review highlights the current understanding of the mechanisms that regulate VEGF gene expression and mediate its biological effects and how these processes may become altered during diabetes. The cellular and molecular alterations that characterize experimental models of diabetes are considered in relation to the influence of high glucose-mediated oxidative stress on VEGF expression and on the mechanisms of VEGF's actions under hyperglycemic induction. Finally, potential therapeutic strategies for preventing VEGF overexpression or blocking its pathological effects in the diabetic retina are considered. Copyright © 2003 John Wiley & Sons, Ltd. [source] How much of a priority is treating erectile dysfunction?DIABETIC MEDICINE, Issue 3 2003A study of patients' perceptions Abstract Background Erectile dysfunction (ED) is one complication of diabetes for which the treatment is rationed. Despite considerable public debate there has been no formal assessment of the views of patients and sufferers of the priority of treating ED. Aims To determine the perceptions of diabetic patients of the relative priority of treating ED in comparison with treatments for other diabetic complications and common medical conditions. Methods Psychological measures were used to assess subjects' perceptions of the relative importance of ED in comparison with eight other common problems (blindness, foot ulcers, high blood pressure, impotence, kidney disease, high cholesterol, migraine, mild indigestion and sleeping difficulties). The concept of willingness to pay was used to assess the amount per month participants would be prepared to pay for treatment for ED and other conditions. Four groups (controls, healthy diabetic men, impotent diabetic men and impotent diabetic men not in a sexual relationship) were studied. Results Significant differences were found between the four groups with regard to the ranking of the importance of ED compared with other health problems. Impotent diabetic male patients were prepared to pay more for treatment for their condition than all other conditions except blindness and renal failure. Conclusions Men with diabetes, in particular ED sufferers, believe ED has a major impact on quality of life and is as important to treat as many other conditions associated with diabetes. Diabet. Med. 20, 205,209 (2003) [source] Blindness following a diabetic foot infection: a variant to the ,eye,foot syndrome'?DIABETIC MEDICINE, Issue 7 2000K. C. J. Yuen SUMMARY Aims The ,eye,foot syndrome' was initially described by Walsh et,al. to highlight the important association of foot lesions in patients with diabetic retinopathy. We present a case of a 58-year-old patient with Type 2 diabetes mellitus who developed blindness following endogenous staphylococcal endophthalmitis from an infected foot ulcer. Results Our case describes the link between the eye and the foot but is somewhat different to the association as described by Walsh et,al. Endogenous endophthalmitis is rare with diabetic patients being especially at risk, and we report the first case of endogenous staphylococcal endophthalmitis related to a diabetic foot lesion. Conclusions Our case illustrates several important issues in the management of diabetic patients admitted to hospital with infection; the need to thoroughly examine the feet to ascertain any foot lesions and any underlying peripheral vascular disease or peripheral neuropathy, to treat aggressively any infected foot lesions to prevent serious complications of septicaemia and to consider rare conditions like endogenous endophthalmitis in any diabetic patient presenting with acute visual impairment and septicaemia. [source] Conjunctival impression cytology in trachomaDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2009Anshu M.D., D.N.B. Abstract Trachoma is one of the leading causes of blindness and clinical examination remains the mainstay of diagnosis. However there is need to evaluate simple, inexpensive techniques which can be used for screening of trachoma in endemic regions. We report two cases where conjunctival impression cytology played a part in confirming the diagnosis of trachoma. We used a modified technique of obtaining conjunctival impressions, which not only met with better patient compliance and minimal ocular distress, but also provided better cellularity and morphology of cells for evaluation. The impression smears showed squamous metaplasia and loss of goblet cells. The cytoplasm of these cells had a hazy, moth eaten appearance and showed presence of intracytoplasmic inclusions. These basophilic inclusions were present singly and in clusters and were around 5 ,m in diameter. A large number of these inclusions were present extracellularly as well. Conjunctival impression cytology is a simple procedure which needs to be evaluated for its potential to be used for screening trachoma in endemic areas. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source] Review of bupropion for smoking cessationDRUG AND ALCOHOL REVIEW, Issue 2 2003ROBYN RICHMOND Abstract The advent of bupropion hydrochloride sustained release (Zyban) has heralded a major change in the options available for smoking cessation pharmacotherapy. Bupropion is a selective re-uptake inhibitor of dopamine and noradrenalin which prevents or reduces cravings and other features of nicotine withdrawal. Bupropion is a useful oral and non-nicotine form of pharmacotherapy for smoking cessation. For this review a total of 221 papers were reviewed plus poster presentations. This review examines in detail original clinical trials on efficacy, categorised according to whether they were acute treatment trials in healthy smokers; studies in specific populations such as people with depression, chronic obstructive pulmonary disease (COPD) or cardiovascular disease; or relapse prevention studies. Overall, these studies in varying populations comprising over four thousand subjects, showed bupropion consistently produces a positive effect on smoking cessation outcomes. The evidence highlights the major public health role that bupropion has in smoking cessation. The methodological issues of published clinical trials reporting one year outcomes were examined in detail including: completeness of follow-up; loss to follow-up; intention to treat analysis; blindness of assessment; and validation of smoking status. The review discusses contraindications, adverse effects, dose and overdose, addictive potential, and the role of bupropion in reducing cessation-related weight gain. Bupropion combined with or compared to other pharmacotherapies (nicotine patch; nortriptyline) is considered. Impressive evidence exists for the use of bupropion in smoking cessation among difficult patients who are hard-core smokers such as those with cardiovascular disease, chronic obstructive pulmonary disease (COPD) and depression. Bupropion reduces withdrawal symptoms as well as weight gain and is effective for smoking cessation for people with and without a history of depression or alcoholism. Serious side effects of bupropion use are rare. The major safety issue with bupropion is risk of seizures (estimated at approximately 0.1%) and it should not be prescribed to patients with a current seizure disorder or any history of seizures. In clinical trials of bupropion for smoking cessation no seizures were reported. Allergic reactions occur at a rate of approximately 3% and minor adverse effects are common including dry mouth and insomnia. [source] Lesions of the Mitral Valve as a Cause of Central Retinal Artery Occlusion: Presentation and Discussion of Two CasesECHOCARDIOGRAPHY, Issue 1 2010Maryam Ayati M.D. We present two cases of mitral valve lesions that manifested with unilateral blindness caused by central retinal artery occlusion (CRAO): Case 1. A 68-year-old woman was admitted to our clinic for sudden blindness. Retinal artery angiogram showed CRAO. Transthoracic and transesophageal echocardiography (TEE) documented a mass attached to the ventricular side of the posterior mitral leaflet, which at pathology was identified as a blood cyst. Case 2. A 67-year-old man was admitted for a sudden unilateral painless loss of vision. Retinal angiogram documented CRAO, and TEE showed a highly mobile, spherical, lesion on the atrial side of anterior mitral leaflet. In this case, the pathological finding was a degenerated calcified thrombosis. We report on two cases of very rare abnormalities of the mitral valve presenting with a very rare embolic complication, i.e., CRAO. Like for cryptogenic stroke, transesophageal echocardiography plays a central role in the diagnosis of cardiogenic embolic sources. (Echocardiography 2010;27:E1-E3) [source] Equine recurrent uveitis: A clinical manifestation of leptospirosisEQUINE VETERINARY EDUCATION, Issue 10 2009L. Frellstedt Summary Leptospirosis is a zoonosis of worldwide distribution affecting domestic animals, wildlife and man. The bacterial disease is caused by pathogenic Leptospira spp., which are transmitted from reservoir hosts to accidental hosts. Horses are accidental hosts and can become susceptible to leptospiral infections. Widespread exposure to leptospires exists and is significantly more common than clinical disease. Leptospirosis can have different clinical manifestations including abortion, still birth, systemic disease with hepatic or renal dysfunction, and equine recurrent uveitis (ERU). ERU is the most frequently encountered clinical manifestation and this article will focus on the review of leptospira-associated ERU. Equine recurrent uveitis is the most common cause of vision impairment and blindness in horses. The pathogenesis of leptospira-associated ERU involves direct bacterial effects and immune-mediated responses. Clinical signs vary between the acute and chronic phases of the disease and progress over time. The diagnosis of leptospira-associated ERU can be difficult and usually requires a combination of diagnostic tests. Medical and surgical treatments have been described with varying outcomes. The prognosis for sight is usually poor, although core vitrectomy may improve the outcome. Avoidance of leptospiral exposure of horses is the only reliable prevention of leptospira-associated disease. [source] Inactivation of the gene for the nuclear receptor tailless in the brain preserving its function in the eyeEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2007Thorsten Belz Abstract During embryogenesis, tailless, an orphan member of the nuclear receptor family, is expressed in the germinal zones of the brain and the developing retina, and is involved in regulating the cell cycle of progenitor cells. Consequently, a deletion of the tailless gene leads to decreased cell number with associated anatomical defects in the limbic system, the cortex and the eye. These structural abnormalities are associated with blindness, increased aggressiveness, poor performance in learning paradigms and reduced anxiousness. In order to assess the contribution of blindness to the behavioural changes, we established tailless mutant mice with intact visual abilities. We generated a mouse line in which the second exon of the tailless gene is flanked by loxP sites and crossed these animals with a transgenic line expressing the Cre recombinase in the neurogenic area of the developing brain, but not in the eye. The resulting animals have anatomically indistinguishable brains compared with tailless germline mutants, but are not blind. They are less anxious and much more aggressive than controls, like tailless germline mutants. In contrast to germline mutants, the conditional mutants are not impaired in fear conditioning. Furthermore, they show good performance in the Morris water-maze despite severely reduced hippocampal structures. Thus, the pathological aggressiveness and reduced anxiety found in tailless germline mutants are due to malformations caused by inactivation of the tailless gene in the brain, but the poor performance of tailless null mice in learning and memory paradigms is dependent on the associated blindness. [source] Dissociation between top-down attentional control and the time course of visual attention as measured by attentional dwell time in patients with mild cognitive impairmentEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2003Richard J. Perry Abstract Studies of the time course of visual attention have identified a temporary functional blindness to the second of sequentially presented stimuli in that the attentional cost of attending to one visual stimulus may lead to impairments in identifying a second stimulus presented within 500 ms of the first. This phenomenon is known as the attentional blink or attentional dwell time. The neural correlates of the attentional blink and its relationship to mechanisms that control attention are unknown. To examine this relationship we tested healthy controls and subjects in the preclinical stage of Alzheimer's disease, known as mild cognitive impairment (MCI), on a paradigm which affords quantification of both the attentional blink and the top-down control of attention. When subjects were asked to identify both a number and a letter that were rapidly and sequentially presented on a visual display, the detrimental effect that identifying the first stimulus had on the ability to identify the second served as a measure of the attentional blink. When asked to identify only one of the two stimuli, the ability to ignore the first stimulus was a function of their top-down attentional control. The MCI subjects demonstrated a normal attentional dwell time but in contrast they showed impaired top-down attentional control within the same paradigm. This dissociation suggests that these two aspects of visual attention are subserved by different neural systems. The possible neural correlates of these two attentional functions are discussed. [source] Auditory activation of ,visual' cortical areas in the blind mole rat (Spalax ehrenbergi)EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2002Gilles Bronchti Abstract The mole rat (Spalax ehrenbergi) is a subterranean rodent whose adaptations to its fossorial life include an extremely reduced peripheral visual system and an auditory system suited for the perception of vibratory stimuli. We have previously shown that in this blind rodent the dorsal lateral geniculate nucleus, the primary visual thalamic nucleus of sighted mammals, is activated by auditory stimuli. In this report we focus on the manifestation of this cross-modal compensation at the cortical level. Cyto- and myeloarchitectural analyses of the occipital area showed that despite the almost total blindness of the mole rat this area has retained the organization of a typical mammalian primary visual cortex. Application of the metabolic marker 2-deoxyglucose and electrophysiological recording of evoked field potentials and single-unit activity disclosed that a considerable part of this area is activated by auditory stimuli. Previous neuronal tracing studies had revealed the origin of the bulk of this auditory input to be the dorsal lateral geniculate nucleus which itself receives auditory input from the inferior colliculus. [source] The synthetic cannabinoid WIN55212-2 decreases the intraocular pressure in human glaucoma resistant to conventional therapiesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2001Anna Porcella Abstract The search for new ocular hypotensive agents represents a frontier of current eye research because blindness due to optic neuropathy occurs insidiously in 10% of all patients affected by glaucoma. Cannabinoids have been proposed to lower intraocular pressure by either central or peripheral effects but a specific mechanism for this action has never been elucidated. We recently demonstrated the presence of the central cannabinoid receptor (CB1) mRNA and protein in the human ciliary body. In the present study we show that the synthetic CB1 receptor agonist, WIN 55212,2, applied topically at doses of 25 or 50 µg (n = 8), decreases the intraocular pressure of human glaucoma resistant to conventional therapies within the first 30 min (15 ± 0.5% and 23 ± 0.9%, respectively). A maximal reduction of 20 ± 0.7% and 31 ± 0.6%, respectively, is reached in the first 60 min. These data confirm that CB1 receptors have direct involvement in the regulation of human intraocular pressure, and suggest that, among various classes of promising antiglaucoma agents, synthetic CB1 receptor agonists should deserve further research and clinical development. [source] Seed-based systematic discovery of specific transcription factor target genesFEBS JOURNAL, Issue 12 2008Ralf Mrowka Reliable prediction of specific transcription factor target genes is a major challenge in systems biology and functional genomics. Current sequence-based methods yield many false predictions, due to the short and degenerated DNA-binding motifs. Here, we describe a new systematic genome-wide approach, the seed-distribution-distance method, that searches large-scale genome-wide expression data for genes that are similarly expressed as known targets. This method is used to identify genes that are likely targets, allowing sequence-based methods to focus on a subset of genes, giving rise to fewer false-positive predictions. We show by cross-validation that this method is robust in recovering specific target genes. Furthermore, this method identifies genes with typical functions and binding motifs of the seed. The method is illustrated by predicting novel targets of the transcription factor nuclear factor kappaB (NF-,B). Among the new targets is optineurin, which plays a key role in the pathogenesis of acquired blindness caused by adult-onset primary open-angle glaucoma. We show experimentally that the optineurin gene and other predicted genes are targets of NF-,B. Thus, our data provide a missing link in the signalling of NF-,B and the damping function of optineurin in signalling feedback of NF-,B. We present a robust and reliable method to enhance the genome-wide prediction of specific transcription factor target genes that exploits the vast amount of expression information available in public databases today. [source] New Cells for the Human RetinaGERMAN RESEARCH, Issue 2-3 2002Gabriele Thumann PD Dr. Age-dependent damage to the retina can lead to blindness. It may be possible to restore vision by transplanting cells from the iris onto the retina [source] Glaucomatous optic nerve injury involves early astrocyte reactivity and late oligodendrocyte lossGLIA, Issue 7 2010Janice L. Son Abstract Glaucoma, a neurodegenerative disease affecting retinal ganglion cells (RGC), is a leading cause of blindness. Since gliosis is common in neurodegenerative disorders, it is important to describe the changes occurring in various glial populations in glaucoma animal models in relation to axon loss, as only changes that occur early are likely to be useful therapeutic targets. Here, we describe changes occurring in glia within the myelinated portion of the optic nerve (ON) in both DBA/2J mice and in a rat ocular hypertension model. In both glaucoma animal models, we found only a modest loss of oligodendrocytes that occurred after axons had already degenerated. In DBA/2J mice there was proliferation of oligodendrocyte precursor cells (OPCs) and new oligodendrocyte generation. Activation of microglia was detected only in highly degenerated DBA/2J ONs. In contrast, a large increase in astrocyte reactivity occurred early in both animal models. These results are consistent with astrocytes playing a prominent role in regulating axon loss in glaucoma. © 2010 Wiley-Liss, Inc. [source] Acquired factor VIII inhibitor presenting as macular haemorrhageHAEMOPHILIA, Issue 2 2005C. Hon Summary., We report a rare case of idiopathic acquired factor VIII inhibitor in an 80-year old Chinese man presented as sudden onset of monocular blindness because of macular haemorrhage. This was complicated by painful glaucoma that did not respond to medical treatment. The patient died of cerebral haemorrhage shortly afterwards. Most cases of reported intraocular bleeding in acquired haemophiliacs are iatrogenic because of intraocular operations in undiagnosed cases, and spontaneous intraocular haemorrhage has never been reported. The literature reports of intraocular bleeding in hereditary and acquired haemophilia cases are summarized. [source] | ||||||||||||||||||||||||||||||||||