Response to Drs. Shastry and Trese: Phenotype-genotype correlations in X-linked retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaplan, J.; Munnich, A.

1996-11-11

Shastry and Trese recently reported on a large kindred with X-linked retinitis pigmentosa (XLRP) characterized by a loss of central vision and preserved peripheral function. In their report, the disease had an early onset with severe myopia and a loss of central vision, while night blindness occurred later. Genetic analysis suggested that the disease was linked to the RP2 locus, and the authors raised the question of whether other cases linked to RP2 could display a similar loss of central vision. Three years ago, we reported on 4 large XLRP pedigrees with a very early onset with severe myopia andmore » early loss of visual acuity, while in 5 other families the disease started later with night blindness. We showed that the first clinical form was linked to RP2, while the second was linked to RP3. Thus, the major difference between the two forms concerns the initial symptom, information which can be obtained from the parents and patients after careful questioning. By contrast, in adult life, no difference in either severity of disease or aspect of the fundus was observed in our series, regardless of the clinical subtype of XLRP. Some months later, Jacobson et al. reported on a pedigree with an RP2 genotype, and their data support the notion that in XLRP of RP2 type 1, cone dysfunction takes place first, and as the disease advances both rods and cones are affected. We were very happy, therefore, to read that the study of Shastry and Trese fully confirmed our previous findings. 3 refs.« less

Misdiagnosis of X-linked retinitis pigmentosa in a choroideremia patient with heavily pigmented fundi.

PubMed

Nanda, A; Salvetti, A P; Martinez-Fernandez de la Camara, C; MacLaren, R E

2018-06-01

Inherited retinal diseases are thought to be the leading cause of sight loss in the working age population. Mutations found in the RPGR and CHM genes cause retinitis pigmentosa (RP) and choroideremia, respectively. In the first instance, an X-linked family history of visual field loss commonly raises the suspicion of one of these two genes. In choroideremia, the classic description of a white fundal reflex secondary to the widespread chorioretinal degeneration was made over a hundred years ago in Caucasians. But, it is not so obvious in heavily pigmented fundi. Hence, the clinical diagnosis of CHM in non-Caucasian patients may be challenging in the first stages of the disease. Here we report a case of a Southeast Asian gentleman who has a family history of X-linked retinal degeneration and was found to have a confirmed in-frame deletion of 12 DNA nucleotides in exon 15 of the RPGR gene. Later in life, however, his fundal appearance showed unusual areas of circular pigment hypertrophy and clumping. He was therefore tested for carrying a disease-causing mutation in the CHM gene and a null mutation was found. Since gene therapy trials are ongoing for both of these conditions, it has now become critically important to establish the correct genetic diagnosis in order to recruit suitable candidates. Moreover, this case demonstrates the necessity to remain vigilant in the interpretation of genetic results which are inconsistent with clinical features.

CAPILLARY NETWORK ALTERATIONS IN X-LINKED RETINOSCHISIS IMAGED ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PubMed

Romano, Francesco; Arrigo, Alessandro; Chʼng, Soon Wai; Battaglia Parodi, Maurizio; Manitto, Maria Pia; Martina, Elisabetta; Bandello, Francesco; Stanga, Paulo E

2018-06-05

To assess foveal and parafoveal vasculature at the superficial capillary plexus, deep capillary plexus, and choriocapillaris of patients with X-linked retinoschisis by means of optical coherence tomography angiography. Six patients with X-linked retinoschisis (12 eyes) and seven healthy controls (14 eyes) were recruited and underwent complete ophthalmologic examination, including best-corrected visual acuity, dilated fundoscopy, and 3 × 3-mm optical coherence tomography angiography macular scans (DRI OCT Triton; Topcon Corp). After segmentation and quality review, optical coherence tomography angiography slabs were imported into ImageJ 1.50 (NIH; Bethesda) and digitally binarized. Quantification of vessel density was performed after foveal avascular zone area measurement and exclusion. Patients were additionally divided into "responders" and "nonresponders" to dorzolamide therapy. Foveal avascular zone area resulted markedly enlarged at the deep capillary plexus (P < 0.001), particularly in nonresponders. Moreover, patients disclosed a significant deep capillary plexus rarefaction, when compared with controls (P: 0.04); however, a subanalysis revealed that this damage was limited to the fovea (P: 0.006). Finally, the enlargement of foveal avascular zone area positively correlated with a decline in best-corrected visual acuity (P: 0.01). Prominent foveal vascular impairment is detectable in the deep capillary plexus of patients with X-linked retinoschisis. Our results correlate with functional outcomes, suggesting a possible vascular role in X-linked retinoschisis clinical manifestations.

Correlation between spectral-domain OCT findings and visual acuity in X-linked retinoschisis.

PubMed

Yang, Hyun Seung; Lee, Jung Bok; Yoon, Young Hee; Lee, Joo Yong

2014-05-08

To investigate the tomographic characteristics of the outer retina and choroid and their relationship with visual acuity in X-linked juvenile retinoschisis (XLRS) patients using spectral-domain optical coherence tomography (SD-OCT). In this retrospective, observational, case-control study, we analyzed 20 eyes of 10 patients with XLRS using SD-OCT. The clinical and tomographic features of the outer retina, including the external limiting membrane (ELM), inner segment/outer segment (IS/OS) junction, cone cell outer segment tips (COST) line, photoreceptor outer segment (PROS) length, and choroid, were evaluated. As controls, 40 age-, sex-, and refraction-matched healthy eyes (1:2 matched) were randomly selected and imaged in parallel. The most prevalent area of abnormality in the outer retina layer of our patients was the outer plexiform layer (OPL; 60% of all affected eyes) and COST line (75% of all affected eyes). On average, the subfoveal choroid and PROS lengths were 35 μm thicker and 19 μm thinner, respectively, in XLRS patients (P = 0.084 and P < 0.001, respectively). A dominant IS/OS junction, COST line defects, and PROS length were related to patient best-corrected visual acuity (BCVA; P = 0.029, P = 0.001, and P < 0.001, respectively) by univariate analysis. Cone cell outer segment tips line defect and PROS length were the only factors related to BCVA in multivariate analysis (P = 0.028 and 0.003, respectively). Outer plexiform layer and photoreceptor microstructure defects are frequent in XLRS patients. Cone cell outer segment tips line defects and shortened PROS lengths as well as other photoreceptor microstructure defects may be closely related to poor vision in XLRS.

X-33 Flight Visualization

NASA Technical Reports Server (NTRS)

Laue, Jay H.

1998-01-01

The X-33 flight visualization effort has resulted in the integration of high-resolution terrain data with vehicle position and attitude data for planned flights of the X-33 vehicle from its launch site at Edwards AFB, California, to landings at Michael Army Air Field, Utah, and Maelstrom AFB, Montana. Video and Web Site representations of these flight visualizations were produced. In addition, a totally new module was developed to control viewpoints in real-time using a joystick input. Efforts have been initiated, and are presently being continued, for real-time flight coverage visualizations using the data streams from the X-33 vehicle flights. The flight visualizations that have resulted thus far give convincing support to the expectation that the flights of the X-33 will be exciting and significant space flight milestones... flights of this nation's one-half scale predecessor to its first single-stage-to-orbit, fully-reusable launch vehicle system.

Visual loss in Takayasu Arteritis - Look Beyond the Eye.

PubMed

Peter, Jayanthi; Joseph, George; Mathew, Vivek; Peter, John Victor

2014-08-01

Patients with Takayasu arteritis often present with reduced vision related either to the disease per se or due to complications of therapy. We report a patient with Takayasu arteritis who developed acute onset bilateral visual loss 6wks following percutaneous revascularization of occluded aortic arch branches. No ocular cause for the visual loss was evident. The reason for visual loss in this patient was an extraocular cause. Ocular and extraocular causes of visual loss in Takayasu arteritis are discussed.

Lamellar macular hole in X linked retinoschisis

PubMed Central

Kumar, Vinod; Goel, Neha

2016-01-01

X linked retinoschisis (XLRS) is the most common juvenile onset retinal degeneration. The disorder leads to poor vision in old age. Complications, however, can lead to earlier loss of vision in this condition. This report describes two patients of XLRS, who had presented with poor vision because of having had a lamellar macular hole at a young age. Lamellar macular holes are rare and have never been reported to cause early onset poor vision in XLRS. PMID:27170611

Genetics Home Reference: X-linked thrombocytopenia

MedlinePlus

... Facebook Twitter Home Health Conditions X-linked thrombocytopenia X-linked thrombocytopenia Printable PDF Open All Close All ... Javascript to view the expand/collapse boxes. Description X-linked thrombocytopenia is a bleeding disorder that primarily ...

Use of topical dorzolamide for patients with X-linked juvenile retinoschisis: case report.

PubMed

Bastos, André Luís Carvalho de Moura; Freitas, Bruno de Paula; Villas Boas, Oscar; Ramiro, Alexandre Campelo

2008-01-01

X-linked juvenile retinoschisis (XLRS) is a recessively inherited vitreoretinal degeneration characterized by macular pathology and splitting of the neuroretinal layers that is associated with alterations in the XLRS1 gene. There have been no therapeutic interventions known to be effective for patients with X-linked juvenile retinoschisis, but some studies are trying to determine the importance of dorzolamide for the treatment of foveal lesions in this disease. The authors, using optical coherence tomography, describe findings in a patient with X-linked juvenile retinoschisis, before and after a topical use of dorzolamide. Besides the improvement in his visual acuity, further studies are required to elucidate the real prevalence of nonresponse to dorzolamide and the frequency with which there may be a recurrence of foveal cystic changes during continued treatment.

Lamellar macular hole in X linked retinoschisis.

PubMed

Kumar, Vinod; Goel, Neha

2016-05-11

X linked retinoschisis (XLRS) is the most common juvenile onset retinal degeneration. The disorder leads to poor vision in old age. Complications, however, can lead to earlier loss of vision in this condition. This report describes two patients of XLRS, who had presented with poor vision because of having had a lamellar macular hole at a young age. Lamellar macular holes are rare and have never been reported to cause early onset poor vision in XLRS. 2016 BMJ Publishing Group Ltd.

[Importance of family examination in juvenile X-linked retinoschisis].

PubMed

Kłosowska-Zawadka, A; Bernardczyk-Meller, J; Gotz-Wieckowska, A; Krawczyński, M

2005-12-01

Congenital (juvenile) retinoschisis belongs to the group of hereditary vitreoretinopathies. This disorder is inherited in an X-linked recessive pattern and its onset usually occurs in 5- to 10-year-old boys. Presenting clinical signs include decreased visual acuity due to maculopathy. The authors present a case of a 17-year-old boy with decreased visual acuity, hypermetropia, and bilateral retinoschisis with maculopathy upon fundus examination. In view of a 50% risk of the disorder occurring in the brothers of the affected male, they underwent full ophthalmological and electrophysiological examinations (until then asymptomatic). In one of them decreased visual acuity, mixed astigmatism, and maculopathy were present, without any changes of the peripheral retina. In the youngest brother decreased visual acuity, hypermetropia, and maculopathy were diagnosed. Genetic counseling and ophthalmological examination of family members at risk facilitated early recognition of the pathological changes in the siblings. Genetic counseling with pedigree analysis and genetic analysis, if possible, should be offered to all affected patients and family members.

X-linked dominant cone-rod degeneration: Linkage mapping of a new locus for retinitis pigmentosa (RP15) to Xp22.13-p22.11

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuire, R.E.; Sullivan, L.S.; Daiger, S.P.

1995-07-01

Retinitis pigmentosa is the name given to a heterogeneous group of hereditary retinal degenerations characterized by progressive visual field loss, pigmentary changes of the retina, abnormal electroretinograms, and, frequently, night blindness. In this study, we investigated a family with dominant cone-rod degeneration, a variant form of retinitis pigmentosa. We used microsatellite markers to test for linkage to the disease locus and exluded all mapped autosomal loci. However, a marker from the short arm of the X chromosome, DXS989, showed 0% recombination to the disease locus, with a maximum lod (log-odds) score of 3.3. On the basis of this marker, themore » odds favoring X-linked dominant versus autosomal dominant inheritance are > 10{sup 5}:1. Haplotype analysis using an additional nine microsatellite markers places the disease locus in the Xp22.13-p22.11 region and excludes other X-linked disease loci causing retinal degeneration. The clinical expression of the retinal degeneration is consistent with X-linked dominant inheritance with milder, variable effects of Lyonization affecting expression in females. On the basis of these data we propose that this family has a novel form of dominant, X-linked cone-rod degeneration with the gene symbol {open_quotes}RP15{close_quotes}. 17 refs., 2 figs., 4 tabs.« less

MULTIMODAL IMAGING OF MOSAIC RETINOPATHY IN CARRIERS OF HEREDITARY X-LINKED RECESSIVE DISEASES.

PubMed

Wu, An-Lun; Wang, Jung-Pan; Tseng, Yun-Ju; Liu, Laura; Kang, Yu-Chuan; Chen, Kuan-Jen; Chao, An-Ning; Yeh, Lung-Kun; Chen, Tun-Lu; Hwang, Yih-Shiou; Wu, Wei-Chi; Lai, Chi-Chun; Wang, Nan-Kai

2018-05-01

To investigate the clinical features in carriers of X-linked retinitis pigmentosa, X-linked ocular albinism, and choroideremia (CHM) using multimodal imaging and to assess their diagnostic value in these three mosaic retinopathies. We prospectively examined 14 carriers of 3 X-linked recessive disorders (X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM). Details of abnormalities of retinal morphology were evaluated using fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain optical coherence tomography. In six X-linked retinitis pigmentosa carriers, fundus appearance varied from unremarkable to the presence of tapetal-like reflex and pigmentary changes. On FAF imaging, all carriers exhibited a bright radial reflex against a dark background. By spectral domain optical coherence tomography, loss of the ellipsoid zone in the macula was observed in 3 carriers (50%). Regarding the retinal laminar architecture, 4 carriers (66.7%) showed thinning of the outer nuclear layer and a dentate appearance of the outer plexiform layer. All five X-linked ocular albinism carriers showed a characteristic mud-splatter patterned fundus, dark radial streaks against a bright background on FAF imaging, and a normal-appearing retinal structure by spectral domain optical coherence tomography imaging. Two of the 3 CHM carriers (66.7%) showed a diffuse moth-eaten appearance of the fundus, and all 3 showed irregular hyper-FAF and hypo-FAF spots throughout the affected area. In the CHM carriers, the structural changes observed by spectral domain optical coherence tomography imaging were variable. Our findings in an Asian cohort suggest that FAF imaging is a practical diagnostic test for differentiating X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM carriers. Wide-field FAF is an easy and helpful adjunct to testing for the correct diagnosis and identification of lyonization in carriers of these three mosaic retinopathies.

Genetics Home Reference: X-linked dilated cardiomyopathy

MedlinePlus

... Twitter Home Health Conditions X-linked dilated cardiomyopathy X-linked dilated cardiomyopathy Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description X-linked dilated cardiomyopathy is a form of heart ...

Genetics Home Reference: X-linked myotubular myopathy

MedlinePlus

... Twitter Home Health Conditions X-linked myotubular myopathy X-linked myotubular myopathy Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description X-linked myotubular myopathy is a condition that primarily ...

Genetics Home Reference: X-linked sideroblastic anemia

MedlinePlus

... Twitter Home Health Conditions X-linked sideroblastic anemia X-linked sideroblastic anemia Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description X-linked sideroblastic anemia is an inherited disorder that ...

Effects of Peripheral Visual Field Loss on Eye Movements During Visual Search

PubMed Central

Wiecek, Emily; Pasquale, Louis R.; Fiser, Jozsef; Dakin, Steven; Bex, Peter J.

2012-01-01

Natural vision involves sequential eye movements that bring the fovea to locations selected by peripheral vision. How peripheral visual field loss (PVFL) affects this process is not well understood. We examine how the location and extent of PVFL affects eye movement behavior in a naturalistic visual search task. Ten patients with PVFL and 13 normally sighted subjects with full visual fields (FVF) completed 30 visual searches monocularly. Subjects located a 4° × 4° target, pseudo-randomly selected within a 26° × 11° natural image. Eye positions were recorded at 50 Hz. Search duration, fixation duration, saccade size, and number of saccades per trial were not significantly different between PVFL and FVF groups (p > 0.1). A χ2 test showed that the distributions of saccade directions for PVFL and FVL subjects were significantly different in 8 out of 10 cases (p < 0.01). Humphrey Visual Field pattern deviations for each subject were compared with the spatial distribution of eye movement directions. There were no significant correlations between saccade directional bias and visual field sensitivity across the 10 patients. Visual search performance was not significantly affected by PVFL. An analysis of eye movement directions revealed patients with PVFL show a biased directional distribution that was not directly related to the locus of vision loss, challenging feed-forward models of eye movement control. Consequently, many patients do not optimally compensate for visual field loss during visual search. PMID:23162511

Mapping the x-linked lymphoproliferative syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skare, J.C.; Milunsky, A.; Byron, K.S.

1987-04-01

The X-linked lymphoproliferative syndrome is triggered by Epstein-Barr virus infection and results in fatal mononucleosis, immunodeficiency, and lymphoproliferative disorders. This study shows that the mutation responsible for X-linked lymphoproliferative syndrome is genetically linked to a restriction fragment length polymorphism detected with the DXS42 probe (from Xq24-q27). The most likely recombination frequency between the loci is 4%, and the associated logarithm of the odds is 5.26. Haplotype analysis using flanking restriction fragment length polymorphism markers indicates that the locus for X-linked lymphoproliferative syndrome is distal to probe DXS42 but proximal to probe DXS99 (from Xq26-q27). It is now possible to predictmore » which members of a family with X-linked lymphoproliferative syndrome are carrier females and to diagnose the syndrome prenatally.« less

Linked exploratory visualizations for uncertain MR spectroscopy data

NASA Astrophysics Data System (ADS)

Feng, David; Kwock, Lester; Lee, Yueh; Taylor, Russell M., II

2010-01-01

We present a system for visualizing magnetic resonance spectroscopy (MRS) data sets. Using MRS, radiologists generate multiple 3D scalar fields of metabolite concentrations within the brain and compare them to anatomical magnetic resonance imaging. By understanding the relationship between metabolic makeup and anatomical structure, radiologists hope to better diagnose and treat tumors and lesions. Our system consists of three linked visualizations: a spatial glyph-based technique we call Scaled Data-Driven Spheres, a parallel coordinates visualization augmented to incorporate uncertainty in the data, and a slice plane for accurate data value extraction. The parallel coordinates visualization uses specialized brush interactions designed to help users identify nontrivial linear relationships between scalar fields. We describe two novel contributions to parallel coordinates visualizations: linear function brushing and new axis construction. Users have discovered significant relationships among metabolites and anatomy by linking interactions between the three visualizations.

Linked Exploratory Visualizations for Uncertain MR Spectroscopy Data

PubMed Central

Feng, David; Kwock, Lester; Lee, Yueh; Taylor, Russell M.

2010-01-01

We present a system for visualizing magnetic resonance spectroscopy (MRS) data sets. Using MRS, radiologists generate multiple 3D scalar fields of metabolite concentrations within the brain and compare them to anatomical magnetic resonance imaging. By understanding the relationship between metabolic makeup and anatomical structure, radiologists hope to better diagnose and treat tumors and lesions. Our system consists of three linked visualizations: a spatial glyph-based technique we call Scaled Data-Driven Spheres, a parallel coordinates visualization augmented to incorporate uncertainty in the data, and a slice plane for accurate data value extraction. The parallel coordinates visualization uses specialized brush interactions designed to help users identify nontrivial linear relationships between scalar fields. We describe two novel contributions to parallel coordinates visualizations: linear function brushing and new axis construction. Users have discovered significant relationships among metabolites and anatomy by linking interactions between the three visualizations. PMID:21152337

Paternal inheritance of classic X-linked bilateral periventricular nodular heterotopia.

PubMed

Kasper, Burkhard S; Kurzbuch, Katrin; Chang, Bernard S; Pauli, Elisabeth; Hamer, Hajo M; Winkler, Jürgen; Hehr, Ute

2013-06-01

Periventricular nodular heterotopia (PNH) is a developmental disorder of the central nervous system, characterized by heterotopic nodules of gray matter resulting from disturbed neuronal migration. The most common form of bilateral PNH is X-linked dominant inherited, caused by mutations in the Filamin A gene (FLNA) and associated with a wide variety of other clinical findings including congenital heart disease. The typical patient with FLNA-associated PNH is female and presents with difficult to treat seizures. In contrast, hemizygous FLNA loss of function mutations in males are reported to be perinatally lethal. In X-linked dominant traits like FLNA-associated PNH the causal mutation is commonly inherited from the mother. Here, we present an exceptional family with paternal transmission of classic bilateral FLNA-associated PNH from a mildly affected father with somatic and germline mosaicism for a c.5686G>A FLNA splice mutation to both daughters with strikingly variable clinical manifestation and PNH extent in cerebral MR imaging. Our observations emphasize the importance to consider in genetic counseling and risk assessment the rare genetic constellation of paternal transmission for families with X-linked dominant inherited FLNA-associated PNH. Copyright © 2013 Wiley Periodicals, Inc.

Loss-of-function mutations in IGSF1 cause an X-linked syndrome of central hypothyroidism and testicular enlargement

PubMed Central

Sun, Yu; Bak, Beata; Schoenmakers, Nadia; van Trotsenburg, A.S. Paul; Oostdijk, Wilma; Voshol, Peter; Cambridge, Emma; White, Jacqueline K.; le Tissier, Paul; Gharavy, S. Neda Mousavy; Martinez-Barbera, Juan P.; Stokvis-Brantsma, Wilhelmina H.; Vulsma, Thomas; Kempers, Marlies J.; Persani, Luca; Campi, Irene; Bonomi, Marco; Beck-Peccoz, Paolo; Zhu, Hongdong; Davis, Timothy M.E.; Hokken-Koelega, Anita C.S.; Del Blanco, Daria Gorbenko; Rangasami, Jayanti J.; Ruivenkamp, Claudia A.L.; Laros, Jeroen F.J.; Kriek, Marjolein; Kant, Sarina G.; Bosch, Cathy A.J.; Biermasz, Nienke R.; Appelman-Dijkstra, Natasha M.; Corssmit, Eleonora P.; Hovens, Guido C.J.; Pereira, Alberto M.; den Dunnen, Johan T.; Wade, Michael G.; Breuning, Martijn H.; Hennekam, Raoul C.; Chatterjee, Krishna; Dattani, Mehul T.; Wit, Jan M.; Bernard, Daniel J.

2012-01-01

Congenital central hypothyroidism occurs either in isolation or in conjunction with other pituitary hormone deficits. Using exome and candidate gene sequencing, we identified eight distinct mutations and two deletions in IGSF1 in males from eleven unrelated families with central hypothyroidism, testicular enlargement, and variably low prolactin concentrations. IGSF1 is a membrane glycoprotein highly expressed in the anterior pituitary gland and the identified mutations impair its trafficking to the cell surface in heterologous cells. Igsf1-deficient male mice show diminished pituitary and serum thyroid-stimulating hormone (TSH) concentrations, reduced pituitary thyrotropin-releasing hormone (TRH) receptor expression, decreased triiodothyronine concentrations, and increased body mass. Collectively, our observations delineate a novel X-linked disorder in which loss-of-function mutations in IGSF1 cause central hypothyroidism, likely secondary to an associated impairment in pituitary TRH signaling. PMID:23143598

Visual loss after spine surgery: a population-based study.

PubMed

Patil, Chirag G; Lad, Eleonora M; Lad, Shivanand P; Ho, Chris; Boakye, Maxwell

2008-06-01

Retrospective cohort study using National inpatient sample administrative data. To determine national estimates of visual impairment and ischemic optic neuropathy after spine surgery. Loss of vision after spine surgery is rare but has devastating complications that has gained increasing recognition in the recent literature. National population-based studies of visual complications after spine surgery are lacking. All patients from 1993 to 2002 who underwent spine surgery (Clinical Classifications software procedure code: 3, 158) and who had ischemic optic neuropathy (ION) (ICD9-CM code 377.41), central retinal artery occlusion (CRAO) (ICD9-CM code 362.31) or non-ION, non-CRAO perioperative visual impairment (ICD9-CM codes: 369, 368.4, 368.8-9368.11-13) were included. Univariate and multivariate analysis were performed to identify potential risk factors. The overall incidence of visual disturbance after spine surgery was 0.094%. Spine surgery for scoliosis correction and posterior lumbar fusion had the highest rates of postoperative visual loss of 0.28% and 0.14% respectively. Pediatric patients (<18 years) were 5.8 times and elderly patients (>84 years) were 3.2 times more likely than, patients 18 to 44 years of age to develop non-ION, non-CRAO visual loss after spine surgery. Patients with peripheral vascular disease (OR = 2.0), hypertension (OR = 1.3), and those who received blood transfusion (OR = 2.2) were more likely to develop non-ION, non-CRAO vision loss after spine surgery. Ischemic optic neuropathy was present in 0.006% of patients. Hypotension (OR = 10.1), peripheral vascular disease (OR = 6.3) and anemia (OR = 5.9) were the strongest risk factors identified for the development of ION. We used multivariate analysis to identify significant risk factors for visual loss after spine surgery. National population-based estimate of visual impairment after spine surgery confirms that ophthalmic complications after spine surgery are rare. Since visual loss may be

X-linked juvenile retinoschisis: Clinical diagnosis, genetic analysis, and molecular mechanisms

PubMed Central

Molday, Robert S.; Kellner, Ulrich; Weber, Bernhard H.F.

2012-01-01

X-linked juvenile retinoschisis (XLRS, MIM 312700) is a common early onset macular degeneration in males characterized by mild to severe loss in visual acuity, splitting of retinal layers, and a reduction in the b-wave of the electroretinogram (ERG). The RS1 gene (MIM 300839) associated with the disease encodes retinoschisin, a 224 amino acid protein containing a discoidin domain as the major structural unit, an N-terminal cleavable signal sequence, and regions responsible for subunit oligomerization. Retinoschisin is secreted from retinal cells as a disulphide-linked homo-octameric complex which binds to the surface of photoreceptors and bipolar cells to help maintain the integrity of the retina. Over 190 disease-causing mutations in the RS1 gene are known with most mutations occurring as non-synonymous changes in the discoidin domain. Cell expression studies have shown that disease-associated missense mutations in the discoidin domain cause severe protein misfolding and retention in the endoplasmic reticulum, mutations in the signal sequence result in aberrant protein synthesis, and mutations in regions flanking the discoidin domain cause defective disulphide-linked subunit assembly, all of which produce a non-functional protein. Knockout mice deficient in retinoschisin have been generated and shown to display most of the characteristic features found in XLRS patients. Recombinant adeno-associated virus (rAAV) mediated delivery of the normal RS1 gene to the retina of young knockout mice result in long term retinoschisin expression and rescue of retinal structure and function providing a ‘proof of concept’ that gene therapy may be an effective treatment for XLRS. PMID:22245536

Retinal detachment 7 years after prophylactic schisis cavity excision in juvenile X-linked retinoschisis.

PubMed

Sobrin, Lucia; Berrocal, Audina M; Murray, Timothy G

2003-01-01

A 7-year-old boy with X-linked juvenile retinoschisis developed a retinal detachment at the site of previous prophylactic excision of a schisis cavity. The patient underwent a scleral buckle procedure, pars plana vitrectomy, membrane peel, and silicone oil injection with successful reattachment. At last follow-up, the visual acuity was 20/400 and the retina was attached. Prophylactic excision of a schisis cavity may be complicated by retinal detachment several years after the surgery. Given the favorable natural history of schisis cavities in X-linked juvenile retinoschisis, the decision to perform prophylactic excision should be undertaken cautiously after full consideration of the potential complications.

Ganglion Cell Loss and Age-Related Visual Loss: A Cortical Pooling Analysis

PubMed Central

SCHMIDT, LAURA A.; LY-SCHROEDER, EMILY; SWANSON, WILLIAM H.

2006-01-01

Purpose To evaluate the ability of the cortical pooling model to predict the effects of random, mild ganglion cell loss, we compared the predictions of the model with the age-related loss and variability in achromatic and chromatic contrast sensitivity. Methods The relative sensitivity to small (0.5°) and large (3.0°) stimuli was compared in older (mean = 67 years, n = 27) and younger (mean = 23 years, n = 32) adults. Contrast sensitivity for modulations along the luminance, equiluminant L-cone, and equiluminant S-cone axes was assessed at the fovea and at four peripheral locations (12°). Results When the stimuli were large, threshold measurements obtained from all participants were reliable and well within the range of modulations along the chromatic axes that could be produced by the phosphors of the CRT. For the large stimuli, neither long- nor short-term variability increased as a function of age. Increasing the size of the stimulus did not decrease the magnitude of the age-related losses when the stimulus was chromatic, and visual losses observed with large chromatic stimuli were not different from those obtained with small achromatic stimuli. Moreover, chromatic contrast sensitivity assessments identified significant visual losses in four individuals who were not identified by achromatic contrast sensitivity assessments and only missed identifying one individual with significant losses in achromatic contrast sensitivity. Conclusions The declines in achromatic and chromatic sensitivity as a function of age (0.4 – 0.7 dB per decade) were similar to those obtained in previous studies of achromatic and chromatic perimetry and are consistent with the loss of retinal ganglion cells reported in histologic studies. The results of this study are consistent with the predictions the cortical pooling model makes for both variability and contrast sensitivity. These findings emphasize that selective visual impairments do not necessarily reflect preferential damage to

Genetics Home Reference: X-linked severe combined immunodeficiency

MedlinePlus

... Facebook Twitter Home Health Conditions X-linked SCID X-linked severe combined immunodeficiency Printable PDF Open All ... Javascript to view the expand/collapse boxes. Description X-linked severe combined immunodeficiency (SCID) is an inherited ...

Genetics Home Reference: X-linked adrenal hypoplasia congenita

MedlinePlus

... Home Health Conditions X-linked adrenal hypoplasia congenita X-linked adrenal hypoplasia congenita Printable PDF Open All ... Javascript to view the expand/collapse boxes. Description X-linked adrenal hypoplasia congenita is a disorder that ...

Genetics Home Reference: X-linked chondrodysplasia punctata 1

MedlinePlus

... Home Health Conditions X-linked chondrodysplasia punctata 1 X-linked chondrodysplasia punctata 1 Printable PDF Open All ... Javascript to view the expand/collapse boxes. Description X-linked chondrodysplasia punctata 1 is a disorder of ...

LinkWinds: An Approach to Visual Data Analysis

NASA Technical Reports Server (NTRS)

Jacobson, Allan S.

1992-01-01

The Linked Windows Interactive Data System (LinkWinds) is a prototype visual data exploration and analysis system resulting from a NASA/JPL program of research into graphical methods for rapidly accessing, displaying and analyzing large multivariate multidisciplinary datasets. It is an integrated multi-application execution environment allowing the dynamic interconnection of multiple windows containing visual displays and/or controls through a data-linking paradigm. This paradigm, which results in a system much like a graphical spreadsheet, is not only a powerful method for organizing large amounts of data for analysis, but provides a highly intuitive, easy to learn user interface on top of the traditional graphical user interface.

Visual prompt poster for promoting patient-physician conversations on weight loss.

PubMed

Stephens, Gillian S; Blanken, Stephanie E; Greiner, K Allen; Chumley, Heidi S

2008-01-01

This study investigated the effect of a simple visual prompt in the form of a poster on the occurrence of patient-physician weight loss conversations during routine office encounters in a primary care outpatient clinic. We conducted a 2-phase study in a family medicine residency program outpatient clinic in August and September 2006. During the first phase, lasting 5 days, we surveyed all nonpregnant adult patients (preintervention group) about weight loss. We then implemented a visual prompt in the form of a colorful poster (11 x 17 inches) in both English and Spanish. The poster read "Do you want to lose weight? Ask your doctor today!" and included a picture of a bathroom scale. During the second phase, also lasting 5 days, we again surveyed all nonpregnant adult patients (postintervention group). Analyses were based on 283 patients in the preintervention group and 386 patients in the postintervention group. The mean body mass index, obtained from medical records, did not differ significantly between groups (31 vs 32 kg/m2, respectively). Fully 60% of patients in the postintervention group recalled seeing the poster during their visit; however, the percentage of patients who reported discussing weight loss with their physician did not differ between the preintervention and postintervention groups overall (29% vs 27%), among the two-thirds of patients who wanted to lose weight (26% vs 23%), or when only postintervention patients who saw the poster were included in the comparison (29% vs 29%). The large majority of patients in both groups who had such discussions--82% and 77%--indicated that they found them useful; the difference between groups was not significant. A simple visual prompt in the form of a poster directed at patients did not increase the occurrence of conversations between patients and their physicians about weight loss.

A prospective profile of visual field loss following stroke: prevalence, type, rehabilitation, and outcome.

PubMed

Rowe, Fiona J; Wright, David; Brand, Darren; Jackson, Carole; Harrison, Shirley; Maan, Tallat; Scott, Claire; Vogwell, Linda; Peel, Sarah; Akerman, Nicola; Dodridge, Caroline; Howard, Claire; Shipman, Tracey; Sperring, Una; Macdiarmid, Sonia; Freeman, Cicely

2013-01-01

To profile site of stroke/cerebrovascular accident, type and extent of field loss, treatment options, and outcome. Prospective multicentre cohort trial. Standardised referral and investigation protocol of visual parameters. 915 patients were recruited with a mean age of 69 years (SD 14). 479 patients (52%) had visual field loss. 51 patients (10%) had no visual symptoms. Almost half of symptomatic patients (n = 226) complained only of visual field loss: almost half (n = 226) also had reading difficulty, blurred vision, diplopia, and perceptual difficulties. 31% (n = 151) had visual field loss as their only visual impairment: 69% (n = 328) had low vision, eye movement deficits, or visual perceptual difficulties. Occipital and parietal lobe strokes most commonly caused visual field loss. Treatment options included visual search training, visual awareness, typoscopes, substitutive prisms, low vision aids, refraction, and occlusive patches. At followup 15 patients (7.5%) had full recovery, 78 (39%) had improvement, and 104 (52%) had no recovery. Two patients (1%) had further decline of visual field. Patients with visual field loss had lower quality of life scores than stroke patients without visual impairment. Stroke survivors with visual field loss require assessment to accurately define type and extent of loss, diagnose coexistent visual impairments, and offer targeted treatment.

X-linked juvenile retinoschisis: clinical diagnosis, genetic analysis, and molecular mechanisms.

PubMed

Molday, Robert S; Kellner, Ulrich; Weber, Bernhard H F

2012-05-01

X-linked juvenile retinoschisis (XLRS, MIM 312700) is a common early onset macular degeneration in males characterized by mild to severe loss in visual acuity, splitting of retinal layers, and a reduction in the b-wave of the electroretinogram (ERG). The RS1 gene (MIM 300839) associated with the disease encodes retinoschisin, a 224 amino acid protein containing a discoidin domain as the major structural unit, an N-terminal cleavable signal sequence, and regions responsible for subunit oligomerization. Retinoschisin is secreted from retinal cells as a disulphide-linked homo-octameric complex which binds to the surface of photoreceptors and bipolar cells to help maintain the integrity of the retina. Over 190 disease-causing mutations in the RS1 gene are known with most mutations occurring as non-synonymous changes in the discoidin domain. Cell expression studies have shown that disease-associated missense mutations in the discoidin domain cause severe protein misfolding and retention in the endoplasmic reticulum, mutations in the signal sequence result in aberrant protein synthesis, and mutations in regions flanking the discoidin domain cause defective disulphide-linked subunit assembly, all of which produce a non-functional protein. Knockout mice deficient in retinoschisin have been generated and shown to display most of the characteristic features found in XLRS patients. Recombinant adeno-associated virus (rAAV) mediated delivery of the normal RS1 gene to the retina of young knockout mice result in long-term retinoschisin expression and rescue of retinal structure and function providing a 'proof of concept' that gene therapy may be an effective treatment for XLRS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Recapitulating X-Linked Juvenile Retinoschisis in Mouse Model by Knock-In Patient-Specific Novel Mutation.

PubMed

Chen, Ding; Xu, Tao; Tu, Mengjun; Xu, Jinlin; Zhou, Chenchen; Cheng, Lulu; Yang, Ruqing; Yang, Tanchu; Zheng, Weiwei; He, Xiubin; Deng, Ruzhi; Ge, Xianglian; Li, Jin; Song, Zongming; Zhao, Junzhao; Gu, Feng

2017-01-01

X-linked juvenile retinoschisis (XLRS) is a retinal disease caused by mutations in the gene encoding retinoschisin (RS1), which leads to a significant proportion of visual impairment and blindness. To develop personalized genome editing based gene therapy, knock-in animal disease models that have the exact mutation identified in the patients is extremely crucial, and that the way which genome editing in knock-in animals could be easily transferred to the patients. Here we recruited a family diagnosed with XLRS and identified the causative mutation ( RS1 , p.Y65X), then a knock-in mouse model harboring this disease-causative mutation was generated via TALEN (transcription activator-like effector nucleases). We found that the b-wave amplitude of the ERG of the RS1 -KI mice was significantly decreased. Moreover, we observed that the structure of retina in RS1 -KI mice has become disordered, including the disarray of inner nuclear layer and outer nuclear layer, chaos of outer plexiform layer, decreased inner segments of photoreceptor and the loss of outer segments. The novel knock-in mice ( RS1 -KI) harboring patient-specific mutation will be valuable for development of treatment via genome editing mediated gene correction.

Non-visualized pregnancy losses are prognostically important for unexplained recurrent miscarriage.

PubMed

Kolte, A M; van Oppenraaij, R H; Quenby, S; Farquharson, R G; Stephenson, M; Goddijn, M; Christiansen, O B

2014-05-01

Are non-visualized pregnancy losses (biochemical pregnancy loss and failed pregnancy of unknown location combined) in the reproductive history of women with unexplained recurrent miscarriage (RM) negatively associated with the chance of live birth in a subsequent pregnancy? Non-visualized pregnancy losses contribute negatively to the chance for live birth: each non-visualized pregnancy loss confers a relative risk (RR) for live birth of 0.90 (95% CI 0.83; 0.97), equivalent to the RR conferred by each additional clinical miscarriage. The number of clinical miscarriages prior to referral is an important determinant for live birth in women with RM, whereas the significance of non-visualized pregnancy losses is unknown. A retrospective cohort study comprising 587 women with RM seen in a tertiary RM unit 2000-2010. Data on the outcome of the first pregnancy after referral were analysed for 499 women. The study was conducted in the RM Unit at Rigshospitalet, Copenhagen, Denmark. We included all women with unexplained RM, defined as ≥3 consecutive clinical miscarriages or non-visualized pregnancy losses following spontaneous conception or homologous insemination. The category 'non-visualized pregnancy losses' combines biochemical pregnancy loss (positive hCG, no ultrasound performed) and failed PUL (pregnancy of unknown location, positive hCG, but on ultrasound, no pregnancy location established). Demographics were collected, including BMI, age at first pregnancy after referral and outcome of pregnancies prior to referral. Using our own records and records from other Danish hospitals, we verified the outcome of the first pregnancy after referral. For each non-visualized pregnancy loss and miscarriage in the women's reproductive history, the RR for live birth in the first pregnancy after referral was determined by robust Poisson regression analysis, adjusting for risk factors for negative pregnancy outcome. Non-visualized pregnancy losses constituted 37% of reported

Eccentric correction for off-axis vision in central visual field loss.

PubMed

Gustafsson, Jörgen; Unsbo, Peter

2003-07-01

Subjects with absolute central visual field loss use eccentric fixation and magnifying devices to utilize their residual vision. This preliminary study investigated the importance of an accurate eccentric correction of off-axis refractive errors to optimize the residual visual function for these subjects. Photorefraction using the PowerRefractor instrument was used to evaluate the ametropia in eccentric fixation angles. Methods were adapted for measuring visual acuity outside the macula using filtered optotypes from high-pass resolution perimetry. Optical corrections were implemented, and the visual function of subjects with central visual field loss was measured with and without eccentric correction. Of the seven cases reported, five experienced an improvement in visual function in their preferred retinal locus with eccentric refraction. The main result was that optical correction for better image quality on the peripheral retina is important for the vision of subjects with central visual field loss, objectively as well as subjectively.

The correlation between visual acuity and color vision as an indicator of the cause of visual loss.

PubMed

Almog, Yehoshua; Nemet, Arie

2010-06-01

To explore the correlation between visual acuity (VA) and color vision and to establish a guide for the diagnosis of the cause of visual loss based on this correlation. Retrospective comparative evaluation of a diagnostic test. A total of 259 patients with visual impairment caused by 1 of 4 possible disease categories were included. Patients were divided into 4 groups according to the etiology of visual loss: 1) optic neuropathies, 2) macular diseases, 3) media opacities, and 4) amblyopia. The best-corrected VA was established and a standard Ishihara 15 color plates was tested and correlated to the VA in every group separately. Correlation between the VA and the color vision along the different etiologies was evaluated. Frequency of each combination of color vision and VA in every disease category was established. VA is correlated with color vision in all 4 disease categories. For the same degree of VA loss, patients with optic neuropathy are most likely and patients with amblyopia are the least expected to have a significant color vision loss. Patients with optic neuropathy had considerably worse average color vision (6.7/15) compared to patients in the other 3 disease categories: 11.1/15 (macular diseases), 13.2/15 (media opacities), and 13.4/15 (amblyopia). Diseases of the optic nerve affect color vision earlier and more profoundly than other diseases. When the cause of visual loss is uncertain, the correlation between the severity of color vision and VA loss can imply the possible etiology of the visual loss. Copyright 2010 Elsevier Inc. All rights reserved.

Genetics Home Reference: X-linked congenital stationary night blindness

MedlinePlus

... Health Conditions X-linked congenital stationary night blindness X-linked congenital stationary night blindness Printable PDF Open ... Javascript to view the expand/collapse boxes. Description X-linked congenital stationary night blindness is a disorder ...

Genetics Home Reference: X-linked lissencephaly with abnormal genitalia

MedlinePlus

... Health Conditions X-linked lissencephaly with abnormal genitalia X-linked lissencephaly with abnormal genitalia Printable PDF Open ... Javascript to view the expand/collapse boxes. Description X-linked lissencephaly with abnormal genitalia (XLAG) is a ...

Genetics Home Reference: X-linked sideroblastic anemia and ataxia

MedlinePlus

... Health Conditions X-linked sideroblastic anemia and ataxia X-linked sideroblastic anemia and ataxia Printable PDF Open ... Javascript to view the expand/collapse boxes. Description X-linked sideroblastic anemia and ataxia is a rare ...

Genetics Home Reference: X-linked intellectual disability, Siderius type

MedlinePlus

... Health Conditions X-linked intellectual disability, Siderius type X-linked intellectual disability, Siderius type Printable PDF Open ... Javascript to view the expand/collapse boxes. Description X-linked intellectual disability, Siderius type is a condition ...

Test-Retest Intervisit Variability of Functional and Structural Parameters in X-Linked Retinoschisis.

PubMed

Jeffrey, Brett G; Cukras, Catherine A; Vitale, Susan; Turriff, Amy; Bowles, Kristin; Sieving, Paul A

2014-09-01

To examine the variability of four outcome measures that could be used to address safety and efficacy in therapeutic trials with X-linked juvenile retinoschisis. Seven men with confirmed mutations in the RS1 gene were evaluated over four visits spanning 6 months. Assessments included visual acuity, full-field electroretinograms (ERG), microperimetric macular sensitivity, and retinal thickness measured by optical coherence tomography (OCT). Eyes were separated into Better or Worse Eye groups based on acuity at baseline. Repeatability coefficients were calculated for each parameter and jackknife resampling used to derive 95% confidence intervals (CIs). The threshold for statistically significant change in visual acuity ranged from three to eight letters. For ERG a-wave, an amplitude reduction greater than 56% would be considered significant. For other parameters, variabilities were lower in the Worse Eye group, likely a result of floor effects due to collapse of the schisis pockets and/or retinal atrophy. The criteria for significant change (Better/Worse Eye) for three important parameters were: ERG b/a-wave ratio (0.44/0.23), point wise sensitivity (10.4/7.0 dB), and central retinal thickness (31%/18%). The 95% CI range for visual acuity, ERG, retinal sensitivity, and central retinal thickness relative to baseline are described for this cohort of participants with X-linked juvenile retinoschisis (XLRS). A quantitative understanding of the variability of outcome measures is vital to establishing the safety and efficacy limits for therapeutic trials of XLRS patients.

Genetics Home Reference: X-linked hyper IgM syndrome

MedlinePlus

... Home Health Conditions X-linked hyper IgM syndrome X-linked hyper IgM syndrome Printable PDF Open All ... Javascript to view the expand/collapse boxes. Description X-linked hyper IgM syndrome is a condition that ...

Attitudes towards and perceptions of visual loss and its causes among Hong Kong Chinese adults.

PubMed

Lau, Joseph Tak Fai; Lee, Vincent; Fan, Dorothy; Lau, Mason; Michon, John

2004-06-01

As part of a study of visual function among Hong Kong Chinese adults, their attitudes and perceptions related to visual loss were examined. These included fear of visual loss, negative functional impacts of visual loss, the relationship between ageing and visual loss and help-seeking behaviours related to visual loss. Demographic factors associated with these variables were also studied. The study population were people aged 40 and above randomly selected from the Shatin district of Hong Kong. The participants underwent eye examinations that included visual acuity, intraocular pressure measurement, visual field, slit-lamp biomicroscopy and ophthalmoscopy. The primary cause of visual disability was recorded. The participants were also asked about their attitudes and perceptions regarding visual loss using a structured questionnaire. The prevalence of bilateral visual disability was 2.2% among adults aged 40 or above and 6.4% among adults aged 60 or above. Nearly 36% of the participants selected blindness as the most feared disabling medical condition, which was substantially higher than conditions such as dementia, loss of limbs, deafness or aphasia. Inability to take care of oneself (21.0%), inconvenience related to mobility (20.2%) and inability to work (14.8%) were the three most commonly mentioned 'worst impact' effects of visual loss. Fully 68% of the participants believed that loss of vision is related to ageing. A majority of participants would seek help and advice from family members in case of visual loss. Visual function is perceived to be very important by Hong Kong Chinese adults. The fear of visual loss is widespread and particularly affects self-care and functional abilities. Visual loss is commonly seen as related to ageing. Attitudes and perceptions in this population may be modified by educational and outreach efforts in order to take advantage of preventive measures.

Four-Year Placebo-Controlled Trial of Docosahexaenoic Acid in X-Linked Retinitis Pigmentosa (DHAX Trial)

PubMed Central

Hoffman, Dennis R.; Hughbanks-Wheaton, Dianna K.; Pearson, N. Shirlene; Fish, Gary E.; Spencer, Rand; Takacs, Alison; Klein, Martin; Locke, Kirsten G.; Birch, David G.

2016-01-01

IMPORTANCE X-linked retinitis pigmentosa is a severe inherited retinal degenerative disease with a frequency of 1 in 100 000 persons. Because no cure is available for this orphan disease and treatment options are limited, slowing of disease progression would be a meaningful outcome. OBJECTIVE To determine whether high-dose docosahexaenoic acid (DHA), an ω-3 polyunsaturated fatty acid, slows progression of X-linked retinitis pigmentosa measured by cone electroretinography (ERG). DESIGN, SETTING, AND PARTICIPANTS A 4-year, single-site, randomized, placebo-controlled, double-masked phase 2 clinical trial at a research center specializing in medical retina. Seventy-eight male patients diagnosed as having X-linked retinitis pigmentosa were randomized to DHA or placebo. Data were omitted for 2 patients with non–X-linked retinitis pigmentosa and 16 patients who were unable to follow protocol during the first year. The remaining participants were tested annually and composed a modified intent-to-treat cohort (DHA group, n = 33; placebo group, n = 27). INTERVENTIONS All participants received a multivitamin and were randomly assigned to oral DHA (30 mg/kg/d) or placebo. MAIN OUTCOMES AND MEASURES The primary outcome was the rate of loss of cone ERG function. Secondary outcomes were rod and maximal ERG amplitudes and cone ERG implicit times. Capsule counts and red blood cell DHA levels were assessed to monitor adherence. RESULTS Average (6-month to 4-year) red blood cell DHA levels were 4-fold higher in the DHA group than in the placebo group (P < .001). There was no difference between the DHA and placebo groups in the rate of cone ERG functional loss (0.028 vs 0.022 log µV/y, respectively; P = .30). No group differences were evident for change in rod ERG (P = .27), maximal ERG (P = .65), or cone implicit time (no change over 4 years). The rate of cone loss (ie, event rate) was markedly reduced compared with rates in previous studies. No severe treatment-emergent adverse

Natural course of visual field loss in patients with Type 2 Usher syndrome.

PubMed

Fishman, Gerald A; Bozbeyoglu, Simge; Massof, Robert W; Kimberling, William

2007-06-01

To evaluate the natural course of visual field loss in patients with Type 2 Usher syndrome and different patterns of visual field loss. Fifty-eight patients with Type 2 Usher syndrome who had at least three visual field measurements during a period of at least 3 years were studied. Kinetic visual fields measured on a standard calibrated Goldmann perimeter with II4e and V4e targets were analyzed. The visual field areas in both eyes were determined by planimetry with the use of a digitalizing tablet and computer software and expressed in square inches. The data for each visual field area measurement were transformed to a natural log unit. Using a mixed model regression analysis, values for the half-life of field loss (time during which half of the remaining field area is lost) were estimated. Three different patterns of visual field loss were identified, and the half-life time for each pattern of loss was calculated. Of the 58 patients, 11 were classified as having pattern type I, 12 with pattern type II, and 14 with pattern type III. Of 21 patients whose visual field loss was so advanced that they could not be classified, 15 showed only a small residual central field (Group A) and 6 showed a residual central field with a peripheral island (Group B). The average half-life times varied between 3.85 and 7.37 for the II4e test target and 4.59 to 6.42 for the V4e target. There was no statistically significant difference in the half-life times between the various patterns of field loss or for the test targets. The average half-life times for visual field loss in patients with Usher syndrome Type 2 were statistically similar among those patients with different patterns of visual field loss. These findings will be useful for counseling patients with Type 2 Usher syndrome as to their prognosis for anticipated visual field loss.

Thirty-two years follow-up of X-linked juvenile retinoschisis in a Chinese patient with RS1 mutation.

PubMed

Xu, Fei; Sui, Ruifang; Dong, Fangtian

2012-06-01

A Chinese family with X-linked juvenile retinoschisis (XLRS) was identified. The purpose of this study was to identify genetic defects in this family and to investigate the visual function during the progression of the disease in the proband from childhood to adulthood. The family history was collected and the proband underwent regular ophthalmologic examinations. Venous blood was collected from family members and genomic DNA was extracted. All exons and exon-intron boundaries of the RS1gene were sequenced for gene mutation in this family. The pedigree of interest was a three-generation family with 43 family members, including three affected individuals. The proband clinically diagnosed with XLRS was investigated at 7 years of age with a follow-up of 32 years. Best corrected visual acuity was stable and complications such as vitreous hemorrhage, retinal detachment, and subcapsular cataract arose during this follow-up period. The R213Q mutation in exon6 of RS1 was identified in all affected individuals. Clinical follow-up of an XLRS patient with a typical juvenile retinoschisis phenotype revealed no significant decline in visual acuity during this time period. Various complications such as vitreous hemorrhage and cataract may occur during the progression of the disease which may lead to severe vision loss.

Genetics Home Reference: X-linked dystonia-parkinsonism

MedlinePlus

... X-linked dystonia-parkinsonism syndrome (XDP): clinical and molecular genetic analysis. Brain Pathol. 1992 Oct;2(4):287-95. Review. Citation on PubMed Kaji R, Goto S, Tamiya G, Ando S, Makino S, Lee LV. Molecular dissection and anatomical basis of dystonia: X-linked ...

Web accessibility support for visually impaired users using link content analysis.

PubMed

Iwata, Hajime; Kobayashi, Naofumi; Tachibana, Kenji; Shirogane, Junko; Fukazawa, Yoshiaki

2013-12-01

Web pages are used for a variety of purposes. End users must understand dynamically changing content and sequentially follow page links to find desired material, requiring significant time and effort. However, for visually impaired users using screen readers, it can be difficult to find links to web pages when link text and alternative text descriptions are inappropriate. Our method supports the discovery of content by analyzing 8 categories of link types, and allows visually impaired users to be aware of the content represented by links in advance. This facilitates end users access to necessary information on web pages. Our method of classifying web page links is therefore effective as a means of evaluating accessibility.

X-linked juvenile retinoschisis in females and response to carbonic anhydrase inhibitors: case report and review of the literature.

PubMed

Ali, Syed; Seth, Rajeev

2013-01-01

A 63 year old woman was referred to the retina clinic after her vision failed to improve in her left eye after cataract surgery. X-linked retinoschisis was diagnosed in the patient after her retina exam revealed an area of retinoschisis and a foveal cyst. The OCT confirmed the macular cyst and the ERG showed loss of B waves. The florescein angiogram showed no significant perifoveal leakage. Her foveal cyst resolved after treatment with carbonic anhydrase inhibitors. The patient's son was examined and his ophthalmologic exam, ERG and imaging findings were consistent with X-linked retinoschisis. However, his bilateral foveal cysts did not respond to treatment with carbonic anhydrase inhibitors. X-linked retinoschisis is a very rare disease in women due to its X-linked recessive inheritance and the foveal cysts associated with it can respond to carbonic anhydrase inhibitors.

[Acute visual loss in pregnancy caused by craniopharyngioma].

PubMed

Grillo-Mallo, E; Jiménez-Benito, J; Diéz-Feijóo, E; Alonso Alonso, I; Ferrero Collado, A; Muñoz Quiñones, S

2014-04-01

A 38-year-old female, at 20-weeks gestation, experienced a sudden visual loss and visual-field abnormalities. The neuroimaging tests showed a craniopharyngioma. Surgical removal was performed with a successful outcome as regards the pregnancy and visual function. It is known that pituitary adenomas may grow during pregnancy; however this is unusual in craniopharyngiomas. They usually present with visual problems due to their suprasellar topography. Surgery is the treatment of choice, the outcome essentially depending on its complete resection. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Driving with visual field loss : an exploratory simulation study

DOT National Transportation Integrated Search

2009-01-01

The goal of this study was to identify the influence of peripheral visual field loss (VFL) on driving performance in a motion-based driving simulator. Sixteen drivers (6 with VFL and 10 with normal visual fields) completed a 14 km simulated drive. Th...

Dyslexia Linked to Visual Strengths Useful in Astronomy

NASA Astrophysics Data System (ADS)

Schneps, Matthew H.; Brockmole, J. R.; Rose, L. T.; Pomplun, M.; Sonnert, G.; Greenhill, L. J.

2011-05-01

Dyslexia is a hereditary neurological condition characterized by difficulties in reading, writing, and spelling. The fact that those with dyslexia include many accomplished scientists, including some recognized with a Nobel Prize, has prompted researchers to suggest that the neurology of dyslexia may predispose these individuals to advantages in visually-intensive domains such as science. Here, we report evidence of a link between dyslexia and abilities for visual processing useful in astronomy. First, we show that when images of natural scenes are Gaussian-blurred, so as to remove high-frequency detail (and resemble many astronomical images), college students with dyslexia significantly outperform those who are typical readers in learning the spatial contexts presented. Second, we show that when the threshold ability to detect radio signatures characteristic of black holes is measured in a laboratory simulation, astrophysicists with dyslexia significantly outperform those who are typical readers in this task when the visual periphery is important. In a third experiment, using eye-tracking technologies, we demonstrate that visual strategies significantly correlate with success in the black hole task, but that college students with dyslexia tend not to employ the strategies most likely to lead to success. Collectively, these studies suggest that dyslexia is linked to neurological advantages useful in astronomical careers, but that left to their own devices students with dyslexia may not benefit from these advantages without practice or training. These studies imply that many students who are struggling to read may find successful careers in astronomy or other fields that build on visual advantages linked to their reading disability, but that education and training may be vital in helping these students realize their strengths. This material is based upon work supported by the George E. Burch Fellowship (Smithsonian Institution) and the National Science Foundation

Genetics Home Reference: alpha thalassemia X-linked intellectual disability syndrome

MedlinePlus

... thalassemia X-linked intellectual disability syndrome Alpha thalassemia X-linked intellectual disability syndrome Printable PDF Open All ... view the expand/collapse boxes. Description Alpha thalassemia X-linked intellectual disability syndrome is an inherited disorder ...

Medical review licensing outcomes in drivers with visual field loss in Victoria, Australia

PubMed Central

Muir, Carlyn; Charlton, Judith L; Odell, Morris; Keeffe, Jill; Wood, Joanne; Bohensky, Megan; Fildes, Brian; Oxley, Jennifer; Bentley, Sharon; Rizzo, Matthew

2017-01-01

Background Good vision is essential for safe driving and studies have associated visual impairment with an increased crash risk. Currently, there is little information about the medical review of drivers with visual field loss. This study examines the prevalence of visual field loss among drivers referred for medical review in one Australian jurisdiction and investigates factors associated with licence outcome in this group. Methods A random sample of 10,000 (31.25 per cent) medical review cases was extracted for analysis from the Victorian licensing authority. Files were screened for the presence of six visual field-related medical conditions. Data were captured on a range of variables, including referral source, age, gender, health status, crash history and licence outcome. Prevalence analyses were univariate and descriptive. Logistic regression was used to assess factors associated with licence outcomes in the visual field loss group. Results Approximately 1.9 per cent of the 10,000 medical review cases screened had a visual field loss condition identified (n=194). Among the visual field loss group, 57.2 per cent were permitted to continue driving (conditional/unconditional licence). Primary referral sources were the police, self-referrals and general medical practitioners. Key factors associated with licence test outcomes were visual field condition, age group, crash involvement and referral to the Driver Licensing Authority’s Medical Advisors. Those who were younger had a crash involvement triggering referral and those who were referred to the Medical Advisors were more likely to have a positive licensing outcome. Conclusion The evidence base for making licensing decisions is complicated by the variable causes, patterns, progressions and measuring technologies for visual field loss. This study highlighted that the involvement of an expert medical advisory service in Victoria resulted in an increased likelihood that drivers with visual field loss will be

The cost of misremembering: Inferring the loss function in visual working memory.

PubMed

Sims, Chris R

2015-03-04

Visual working memory (VWM) is a highly limited storage system. A basic consequence of this fact is that visual memories cannot perfectly encode or represent the veridical structure of the world. However, in natural tasks, some memory errors might be more costly than others. This raises the intriguing possibility that the nature of memory error reflects the costs of committing different kinds of errors. Many existing theories assume that visual memories are noise-corrupted versions of afferent perceptual signals. However, this additive noise assumption oversimplifies the problem. Implicit in the behavioral phenomena of visual working memory is the concept of a loss function: a mathematical entity that describes the relative cost to the organism of making different types of memory errors. An optimally efficient memory system is one that minimizes the expected loss according to a particular loss function, while subject to a constraint on memory capacity. This paper describes a novel theoretical framework for characterizing visual working memory in terms of its implicit loss function. Using inverse decision theory, the empirical loss function is estimated from the results of a standard delayed recall visual memory experiment. These results are compared to the predicted behavior of a visual working memory system that is optimally efficient for a previously identified natural task, gaze correction following saccadic error. Finally, the approach is compared to alternative models of visual working memory, and shown to offer a superior account of the empirical data across a range of experimental datasets. © 2015 ARVO.

Visualizing Transmedia Networks: Links, Paths and Peripheries

ERIC Educational Resources Information Center

Ruppel, Marc Nathaniel

2012-01-01

'Visualizing Transmedia Networks: Links, Paths and Peripheries' examines the increasingly complex rhetorical intersections between narrative and media ("old" and "new") in the creation of transmedia fictions, loosely defined as multisensory and multimodal stories told extensively across a diverse media set. In order…

X-linked congenital panhypopituitarism.

PubMed

Schimke, R N; Spaulding, J J; Hollowell, J G

1971-05-01

Two half brothers with panhypopituitary dwarfism are reported who have the same mother and different, unrelated fathers. The subject of hereditary panhypopituitarism is reviewed briefly. It is concluded that there are at least two forms of hereditary panhypopituitary dwarfism, one of which may be X-linked.

The cost of making an eye movement: A direct link between visual working memory and saccade execution.

PubMed

Schut, Martijn J; Van der Stoep, Nathan; Postma, Albert; Van der Stigchel, Stefan

2017-06-01

To facilitate visual continuity across eye movements, the visual system must presaccadically acquire information about the future foveal image. Previous studies have indicated that visual working memory (VWM) affects saccade execution. However, the reverse relation, the effect of saccade execution on VWM load is less clear. To investigate the causal link between saccade execution and VWM, we combined a VWM task and a saccade task. Participants were instructed to remember one, two, or three shapes and performed either a No Saccade-, a Single Saccade- or a Dual (corrective) Saccade-task. The results indicate that items stored in VWM are reported less accurately if a single saccade-or a dual saccade-task is performed next to retaining items in VWM. Importantly, the loss of response accuracy for items retained in VWM by performing a saccade was similar to committing an extra item to VWM. In a second experiment, we observed no cost of executing a saccade for auditory working memory performance, indicating that executing a saccade exclusively taxes the VWM system. Our results suggest that the visual system presaccadically stores the upcoming retinal image, which has a similar VWM load as committing one extra item to memory and interferes with stored VWM content. After the saccade, the visual system can retrieve this item from VWM to evaluate saccade accuracy. Our results support the idea that VWM is a system which is directly linked to saccade execution and promotes visual continuity across saccades.

Transcription precedes loss of Xist coating and depletion of H3K27me3 during X-chromosome reprogramming in the mouse inner cell mass

PubMed Central

Williams, Lucy H.; Kalantry, Sundeep; Starmer, Joshua; Magnuson, Terry

2011-01-01

Repression of Xist RNA expression is considered a prerequisite to reversal of X-chromosome inactivation (XCI) in the mouse inner cell mass (ICM), and reactivation of X-linked genes is thought to follow loss of Xist RNA coating and heterochromatic markers of inactivation, such as methylation of histone H3. We analyzed X-chromosome activity in developing ICMs and show that reactivation of gene expression from the inactive-X initiates in the presence of Xist coating and H3K27me3. Furthermore, depletion of Xist RNA coating through forced upregulation of NANOG does not result in altered reactivation kinetics. Taken together, our observations suggest that in the ICM, X-linked gene transcription and Xist coating are uncoupled. These data fundamentally alter our perception of the reactivation process and support the existence of a mechanism to reactivate Xp-linked genes in the ICM that operates independently of loss of Xist RNA and H3K27me3 from the imprinted inactive-X. PMID:21471155

Phenotype-genotype correlations in X linked retinitis pigmentosa.

PubMed Central

Kaplan, J; Pelet, A; Martin, C; Delrieu, O; Aymé, S; Bonneau, D; Briard, M L; Hanauer, A; Larget-Piet, L; Lefrançois, P

1992-01-01

Retinitis pigmentosa (RP) represents a group of clinically heterogeneous retinal degenerations in which all modes of inheritance have been described. We have previously found two different clinical profiles in X linked RP as a function of age and mode of onset. The first clinical form has very early onset with severe myopia. The second form starts later with night blindness with mild myopia or none. At least two genes have been identified in X linked forms, namely RP2 (linked to DXS7, DXS255, and DXS14) and RP3 (linked to DXS84 and OTC) on the short arm of the X chromosome. In order to contribute to phenotype-genotype correlations in X linked RP, we tested the hypothesis that the two clinical profiles could be accounted for by the two different gene loci. The present study provides evidence for linkage of the clinical form with early myopia as the onset symptom with the RP2 gene (pairwise linkage to DXS255: Z = 3.13 at theta = 0), while the clinical form with later night blindness as the onset symptom is linked to the RP3 gene (pairwise linkage to OTC: Z = 4.16 at theta = 0). Images PMID:1357178

Sex-specific silencing of X-linked genes by Xist RNA

PubMed Central

Gayen, Srimonta; Maclary, Emily; Hinten, Michael; Kalantry, Sundeep

2016-01-01

X-inactive specific transcript (Xist) long noncoding RNA (lncRNA) is thought to catalyze silencing of X-linked genes in cis during X-chromosome inactivation, which equalizes X-linked gene dosage between male and female mammals. To test the impact of Xist RNA on X-linked gene silencing, we ectopically induced endogenous Xist by ablating the antisense repressor Tsix in mice. We find that ectopic Xist RNA induction and subsequent X-linked gene silencing is sex specific in embryos and in differentiating embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs). A higher frequency of XΔTsixY male cells displayed ectopic Xist RNA coating compared with XΔTsixX female cells. This increase reflected the inability of XΔTsixY cells to efficiently silence X-linked genes compared with XΔTsixX cells, despite equivalent Xist RNA induction and coating. Silencing of genes on both Xs resulted in significantly reduced proliferation and increased cell death in XΔTsixX female cells relative to XΔTsixY male cells. Thus, whereas Xist RNA can inactivate the X chromosome in females it may not do so in males. We further found comparable silencing in differentiating XΔTsixY and 39,XΔTsix (XΔTsixO) ESCs, excluding the Y chromosome and instead implicating the X-chromosome dose as the source of the sex-specific differences. Because XΔTsixX female embryonic epiblast cells and EpiSCs harbor an inactivated X chromosome prior to ectopic inactivation of the active XΔTsix X chromosome, we propose that the increased expression of one or more X-inactivation escapees activates Xist and, separately, helps trigger X-linked gene silencing. PMID:26739568

Color-Space-Based Visual-MIMO for V2X Communication.

PubMed

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-04-23

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

Learning to Link Visual Contours

PubMed Central

Li, Wu; Piëch, Valentin; Gilbert, Charles D.

2008-01-01

SUMMARY In complex visual scenes, linking related contour elements is important for object recognition. This process, thought to be stimulus driven and hard wired, has substrates in primary visual cortex (V1). Here, however, we find contour integration in V1 to depend strongly on perceptual learning and top-down influences that are specific to contour detection. In naive monkeys the information about contours embedded in complex backgrounds is absent in V1 neuronal responses, and is independent of the locus of spatial attention. Training animals to find embedded contours induces strong contour-related responses specific to the trained retinotopic region. These responses are most robust when animals perform the contour detection task, but disappear under anesthesia. Our findings suggest that top-down influences dynamically adapt neural circuits according to specific perceptual tasks. This may serve as a general neuronal mechanism of perceptual learning, and reflect top-down mediated changes in cortical states. PMID:18255036

A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes

PubMed Central

Krasovec, Marc; Filatov, Dmitry A.

2018-01-01

Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (πx = 0.016; πaut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex. PMID:29751495

A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes.

PubMed

Krasovec, Marc; Nevado, Bruno; Filatov, Dmitry A

2018-05-03

Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (π x = 0.016; π aut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex.

Heat shock protein expression in cerebral X-linked adrenoleukodystrophy reveals astrocyte stress prior to myelin loss.

PubMed

Görtz, A L; Peferoen, L A N; Gerritsen, W H; van Noort, J M; Bugiani, M; Amor, S

2018-06-01

X-linked adrenoleukodystrophy (X-ALD) is a genetic white matter disorder in which demyelination occurs due to accumulation of very long-chain fatty acids. Inflammation in the brain white matter is a hallmark of the pathology of cerebral X-ALD, but the underlying pathogenic mechanisms are still largely unknown. In other inflammatory demyelinating disorders, such as multiple sclerosis, the expression of heat shock proteins (HSPs) in combination with interferon-γ (IFN-γ) has been suggested to play a prominent role in the initiation of demyelination and inflammation. We therefore investigated these pathways in X-ALD lesions. By immunohistochemistry, we examined the expression of small HSPs (HSPB1, HSPB5, HSPB6, HSPB8) and higher molecular weight HSPs (HSPA, HSPD1), and the expression of elements of the IFN-γ pathway on autopsy material of five patients with X-ALD. The expression of the larger HSPs, HSPA and HSPD1, as well as small HSPs is increased in X-ALD lesions compared with normal-appearing white matter. Such upregulation can already be detected before demyelination and inflammation occur, and it is predominant in astrocytes. The IFN-γ pathway does not seem to play a leading role in the observed inflammation. The finding that astrocytes show signs of cellular stress before demyelination suggests that they play a major role early in the pathogenesis of cerebral X-ALD, and may therefore be involved in the initiation of inflammation and demyelination. © 2017 British Neuropathological Society.

Spontaneous closure of macular hole in a patient with x-linked juvenile retinoschisis.

PubMed

Gao, Hua; Province, William D; Peracha, Mohammed O

2010-01-01

To observe macular hole in a patient with juvenile retinoschisis. A 4-year-old boy with X-linked juvenile retinoschisis was examined and followed-up for 2 years. Optical coherence tomography was used to study his maculae. A full-thickness macular hole was detected by clinical examination and optical coherence tomography. Spontaneous closure of the macular hole was noticed and confirmed by optical coherence tomography 2 years later with visual improvement. Macular hole in patients with juvenile retinoschisis should be observed for at least a short period of time before a surgical repair is considered.

Audio-visual speech processing in age-related hearing loss: Stronger integration and increased frontal lobe recruitment.

PubMed

Rosemann, Stephanie; Thiel, Christiane M

2018-07-15

Hearing loss is associated with difficulties in understanding speech, especially under adverse listening conditions. In these situations, seeing the speaker improves speech intelligibility in hearing-impaired participants. On the neuronal level, previous research has shown cross-modal plastic reorganization in the auditory cortex following hearing loss leading to altered processing of auditory, visual and audio-visual information. However, how reduced auditory input effects audio-visual speech perception in hearing-impaired subjects is largely unknown. We here investigated the impact of mild to moderate age-related hearing loss on processing audio-visual speech using functional magnetic resonance imaging. Normal-hearing and hearing-impaired participants performed two audio-visual speech integration tasks: a sentence detection task inside the scanner and the McGurk illusion outside the scanner. Both tasks consisted of congruent and incongruent audio-visual conditions, as well as auditory-only and visual-only conditions. We found a significantly stronger McGurk illusion in the hearing-impaired participants, which indicates stronger audio-visual integration. Neurally, hearing loss was associated with an increased recruitment of frontal brain areas when processing incongruent audio-visual, auditory and also visual speech stimuli, which may reflect the increased effort to perform the task. Hearing loss modulated both the audio-visual integration strength measured with the McGurk illusion and brain activation in frontal areas in the sentence task, showing stronger integration and higher brain activation with increasing hearing loss. Incongruent compared to congruent audio-visual speech revealed an opposite brain activation pattern in left ventral postcentral gyrus in both groups, with higher activation in hearing-impaired participants in the incongruent condition. Our results indicate that already mild to moderate hearing loss impacts audio-visual speech processing

Child behavior check list and Korean personality inventory for children with functional visual loss.

PubMed

Kyung, Sung Eun; Lee, Sang Mi; Lim, Myung Ho

2014-08-01

To investigate the clinical psychiatric characteristics of children with the main complaint of functional visual loss, their behavior and personality were evaluated by the means of the Korean child behavior check list (K-CBCL), and the Korean personality inventory for children (KPI-C). The evaluation was carried out by the K-CBCL and the KPI-C, the domestically standardized tools, with 20 child subjects suspected of functional visual loss, among the patients who visited our hospital, between August, 2005 and December, 2012. The control group included 160 children in general schools of the same region. The 20 patients whose main complaint was functional visual loss were diagnosed as having a functional visual disorder. The child patient group showed a higher score for the K-CBCL and KPI-C sub-scales of somatic complaints, social problems, aggressive behavior, internalizing problems, externalizing problems, total behavioral problems, somatization and hyperactivity, than that of the control group. The results of the K-CBCL and KPI-C tests among children with functional visual loss, were significantly different from those of the normal control group. This result suggested that psychological factors may influence children with a main complaint of functional visual loss.

Loss of Neurofilament Labeling in the Primary Visual Cortex of Monocularly Deprived Monkeys

PubMed Central

Duffy, Kevin R.; Livingstone, Margaret S.

2009-01-01

Visual experience during early life is important for the development of neural organizations that support visual function. Closing one eye (monocular deprivation) during this sensitive period can cause a reorganization of neural connections within the visual system that leaves the deprived eye functionally disconnected. We have assessed the pattern of neurofilament labeling in monocularly deprived macaque monkeys to examine the possibility that a cytoskeleton change contributes to deprivation-induced reorganization of neural connections within the primary visual cortex (V-1). Monocular deprivation for three months starting around the time of birth caused a significant loss of neurofilament labeling within deprived-eye ocular dominance columns. Three months of monocular deprivation initiated in adulthood did not produce a loss of neurofilament labeling. The evidence that neurofilament loss was found only when deprivation occurred during the sensitive period supports the notion that the loss permits restructuring of deprived-eye neural connections within the visual system. These results provide evidence that, in addition to reorganization of LGN inputs, the intrinsic circuitry of V-1 neurons is altered when monocular deprivation occurs early in development. PMID:15563721

Macular hole in juvenile X-linked retinoschisis.

PubMed

Al-Swaina, Nayef; Nowilaty, Sawsan R

2013-10-01

An 18 year-old male with no antecedent of trauma, systemic syndrome or myopia was referred for surgical treatment of a full thickness macular hole in the left eye. A more careful inspection revealed discrete foveal cystic changes in the fellow eye and subtle peripheral depigmented retinal pigment epithelial changes in both eyes. A spectral-domain optical coherence tomography (SD-OCT) scan confirmed, in addition to the full thickness macular hole in the left eye, microcystic spaces in the nuclear layers of both retinae. The diagnosis of X-linked retinoschisis was confirmed with a full field electroretinogram displaying the typical negative ERG. Macular holes are uncommon in the young and those complicating X-linked retinoschisis are rare. This report highlights the importance of investigating the presence of a macular hole in a young patient and illustrates the clinical and SD-OCT clues beyond the foveal center which led to the correct diagnosis of X-linked juvenile retinoschisis.

X-linked dominant retinitis pigmentosa in an American family

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuire, R.E.; Daiger, S.P.; Blanton, S.H.

1994-09-01

Retinitis pigmentosa is a genetically heterogeneous disease with autosomal dominant (adRP), autosomal recessive and X-linked forms. At least 3 forms of X-linked retinitis pigmentosa have been reported: RP2 which maps to Xp11.4-p 11.23, RP3 which maps to Xp21.1 and RP6, which maps to Xp21.3-p21.1. The X-linked forms of retinitis pigmentosa are generally considered to be recessive as female carriers are not affected or are much less affected than males. Here we report a five generation American family with X-linked retinitis pigmentosa in which both males and females are significantly affected. The disease locus in this family appears to be distinctmore » from RP2 and RP3. The American family (UTAD054) presents with early-onset retinitis pigmentosa. The family appeared to fit an autosomal dominant pattern; however, linkage testing excluded all known adRP loci. Absence of male-to-male transmission in the pedigree suggested the possibility of X-linked dominant inheritance. Thus we tested six microsatellite markers that map to Xp (DXS987, DXS989, DXS993, DXS999, DXS1003 and DXS1110). Of these, DXS989 showed tight linkage with one allele (199) showing a 100% concordance with disease status. The odds favoring an X-linked dominant mode of inheritance in this family, versus autosomal dominant, are 10{sup 5}:1. In addition, recombinations for DXS999, and dXS1110, the two markers flanking DXS989, were observed in affected individuals. These data map the disease locus in this family to a 9 mb region on the X chromosome between Xp22.11 and Xp21.41. In addition, the recombinant individuals exclude close linkage to RP2 and RP3. The observance of high penetrance in females indicates that this family has X-linked dominant retinitis pigmentosa. We suggest that this mode of inheritance should be considered in other families with dominant retinitis pigmentosa but an absence of male-to-male transmission.« less

Can colour vision re-evolve? Variation in the X-linked opsin locus of cathemeral Azara's owl monkeys (Aotus azarae azarae).

PubMed

Mundy, N I; Morningstar, N C; Baden, A L; Fernandez-Duque, E; Dávalos, V M; Bradley, B J

2016-01-01

Do evolutionary specializations lead to evolutionary constraint? This appears plausible, particularly when specialization leads to loss of complex adaptations. In the owl monkey lineage, nocturnality clearly arose from a diurnal ancestor. This behavioural shift was accompanied by morphological changes in the eye and orbit and complete loss of colour vision via missense mutations in the gene encoding the short-wave sensitive visual pigment (SWS opsin). Interestingly, at least one subspecies of owl monkey, Azara's owl monkey (Aotus azarae azarae), has regained activity in daylight. Given that all primate species that are active in daylight, including primarily diurnal species and species that are active during both day and night, have at least dichromatic colour vision, it seems reasonable to propose that dichromacy would be adaptive in A. a. azarae. With a disabled SWS opsin, the main avenue available for Azara's owl monkeys to re-evolve colour vision is via a polymorphism in the intact X-linked opsin locus, which commonly occurs in other New World monkeys. To examine this possibility we assayed variation in the X-linked opsin of A. a. azarae, focusing on the three exons (3, 4 and 5) that control spectral sensitivity. We found low opsin genetic variation on a population level, and no differences at the three main sites that lead to variation in spectral sensitivity in the opsins of other New World monkeys. Two rare alleles with single amino acid variants are segregating in the population, but previous functional studies indicate that these are unlikely to affect spectral sensitivity. Genetic constraint on the re-evolution of colour vision is likely operating in Azara's owl monkey, which may affect the niche that this subspecies is able to occupy.

A Novel Mutation in a Kazakh Family with X-Linked Alport Syndrome

PubMed Central

Rakhimova, Saule E.; Nigmatullina, Nazym B.; Momynaliev, Kuvat T.; Ramanculov, Yerlan M.

2015-01-01

Alport syndrome is a genetic condition that results in hematuria, progressive renal impairment, hearing loss, and occasionally lenticonus and retinopathy. Approximately 80% of Alport syndrome cases are caused by X-linked mutations in the COL4A5 gene encoding type IV collagen. The objective of this study was to define the SNP profiles for COL4A5 in patients with hereditary nephritis and hematuria. For this, we examined four subjects from one Kazakh family clinically affected with X-linked Alport syndrome due to COL4A5 gene mutations. All 51 exons of the COL4A5 gene were screened by linkage analysis and direct DNA sequencing, resulting in the identification of a novel mutation (G641E) in exon 25. The mutation was found only in two affected family individuals but was not present in healthy family members or 200 unrelated healthy controls. This result demonstrates that this novel mutation is pathogenic and has meaningful implications for the diagnosis of patients with Alport syndrome. PMID:26168235

A Novel Mutation in a Kazakh Family with X-Linked Alport Syndrome.

PubMed

Baikara, Barshagul T; Zholdybayeva, Elena V; Rakhimova, Saule E; Nigmatullina, Nazym B; Momynaliev, Kuvat T; Ramanculov, Yerlan M

2015-01-01

Alport syndrome is a genetic condition that results in hematuria, progressive renal impairment, hearing loss, and occasionally lenticonus and retinopathy. Approximately 80% of Alport syndrome cases are caused by X-linked mutations in the COL4A5 gene encoding type IV collagen. The objective of this study was to define the SNP profiles for COL4A5 in patients with hereditary nephritis and hematuria. For this, we examined four subjects from one Kazakh family clinically affected with X-linked Alport syndrome due to COL4A5 gene mutations. All 51 exons of the COL4A5 gene were screened by linkage analysis and direct DNA sequencing, resulting in the identification of a novel mutation (G641E) in exon 25. The mutation was found only in two affected family individuals but was not present in healthy family members or 200 unrelated healthy controls. This result demonstrates that this novel mutation is pathogenic and has meaningful implications for the diagnosis of patients with Alport syndrome.

Simulated visual field loss does not alter turning coordination in healthy young adults.

PubMed

Murray, Nicholas G; Ponce de Leon, Marlina; Ambati, V N Pradeep; Saucedo, Fabricio; Kennedy, Evan; Reed-Jones, Rebecca J

2014-01-01

Turning, while walking, is an important component of adaptive locomotion. Current hypotheses regarding the motor control of body segment coordination during turning suggest heavy influence of visual information. The authors aimed to examine whether visual field impairment (central loss or peripheral loss) affects body segment coordination during walking turns in healthy young adults. No significant differences in the onset time of segments or intersegment coordination were observed because of visual field occlusion. These results suggest that healthy young adults can use visual information obtained from central and peripheral visual fields interchangeably, pointing to flexibility of visuomotor control in healthy young adults. Further study in populations with chronic visual impairment and those with turning difficulties are warranted.

Role of prostaglandins in the pathogenesis of X-linked hypophosphatemia.

PubMed

Baum, Michel; Syal, Ashu; Quigley, Raymond; Seikaly, Mouin

2006-08-01

X-linked hypophosphatemia is an X-linked dominant disorder resulting from a mutation in the PHEX gene. PHEX stands for phosphate-regulating gene with endopeptidase activity, which is located on the X chromosome. Patients with X-linked hypophosphatemia have hypophosphatemia due to renal phosphate wasting and low or inappropriately normal levels of 1,25-dihydroxyvitamin D. The renal phosphate wasting is not intrinsic to the kidney but likely due to an increase in serum levels of fibroblast growth factor-23 (FGF-23), and perhaps other phosphate-wasting peptides previously known as phosphatonins. Patients with X-linked hypophosphatemia have short stature, rickets, bone pain and dental abscesses. Current therapy is oral phosphate and vitamin D which effectively treats the rickets and bone pain but does not adequately improve short stature. In this review, we describe recent observations using Hyp mice; mice with the same mutation as patients with X-linked hypophosphatemia. We have recently found that Hyp mice have abnormal renal prostaglandin production, which may be an important factor in the pathogenesis of this disorder. Administration of FGF-23 in vivo results in phosphaturia and an increase in prostaglandin excretion, and FGF-23 increases proximal tubule prostaglandin production in vitro. In Hyp mice, indomethacin improves the phosphate transport defect in vitro and in vivo. Whether indomethacin has the same effect in patients with X-linked hypophosphatemia is unknown.

[Case of pediatric chronic myeloid leukemia with bilateral visual loss onset].

PubMed

Hara, Yusuke; Kamura, Yumi; Oikawa, Aki; Shichino, Hiroyuki; Mugishima, Hideo; Goto, Hiroshi

2010-05-01

Chronic myeloid leukemia (CML) during childhood is rare, and only been a few cases showed visual disturbances as an initial symptom. We report a pediatric CML case diagnosed by bilateral visual loss. An 11-year-old boy complained of visual loss in both eyes. His best corrected visual acuity was 0.5 in the right eye and 0.2 in the left. Fundus examination showed disc swelling, dilated and tortuous retinal veins and multiple elevated retinal lesions with hemorrhages of various size from one-forth to four disc diameters in both eyes. He was diagnosed as having CML by leucocytosis and systematic work-up including Philadelphia chromosome-positive, BCR-ABL kinase domain in peripheral blood and bone marrow. The ocular findings improved after treatment with hydroxyurea, leukocytaphresis and imatinib. His best corrected visual acuity improved to 0.7 in both eyes. Recent leukemia therapy including imatinib is effective not only for ocular lesions but also to induce hematological remission in childhood CML.

The effects of link format and screen location on visual search of web pages.

PubMed

Ling, Jonathan; Van Schaik, Paul

2004-06-22

Navigation of web pages is of critical importance to the usability of web-based systems such as the World Wide Web and intranets. The primary means of navigation is through the use of hyperlinks. However, few studies have examined the impact of the presentation format of these links on visual search. The present study used a two-factor mixed measures design to investigate whether there was an effect of link format (plain text, underlined, bold, or bold and underlined) upon speed and accuracy of visual search and subjective measures in both the navigation and content areas of web pages. An effect of link format on speed of visual search for both hits and correct rejections was found. This effect was observed in the navigation and the content areas. Link format did not influence accuracy in either screen location. Participants showed highest preference for links that were in bold and underlined, regardless of screen area. These results are discussed in the context of visual search processes and design recommendations are given.

The loss of short-term visual representations over time: decay or temporal distinctiveness?

PubMed

Mercer, Tom

2014-12-01

There has been much recent interest in the loss of visual short-term memories over the passage of time. According to decay theory, visual representations are gradually forgotten as time passes, reflecting a slow and steady distortion of the memory trace. However, this is controversial and decay effects can be explained in other ways. The present experiment aimed to reexamine the maintenance and loss of visual information over the short term. Decay and temporal distinctiveness models were tested using a delayed discrimination task, in which participants compared complex and novel objects over unfilled retention intervals of variable length. Experiment 1 found no significant change in the accuracy of visual memory from 2 to 6 s, but the gap separating trials reliably influenced task performance. Experiment 2 found evidence for information loss at a 10-s retention interval, but temporally separating trials restored the fidelity of visual memory, possibly because temporally isolated representations are distinct from older memory traces. In conclusion, visual representations lose accuracy at some point after 6 s, but only within temporally crowded contexts. These findings highlight the importance of temporal distinctiveness within visual short-term memory. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Contemporary Medical and Surgical Management of X-linked Hypophosphatemic Rickets.

PubMed

Sharkey, Melinda S; Grunseich, Karl; Carpenter, Thomas O

2015-07-01

X-linked hypophosphatemia is an inheritable disorder of renal phosphate wasting that clinically manifests with rachitic bone pathology. X-linked hypophosphatemia is frequently misdiagnosed and mismanaged. Optimized medical therapy is the cornerstone of treatment. Even with ideal medical management, progressive bony deformity may develop in some children and adults. Medical treatment is paramount to the success of orthopaedic surgical procedures in both children and adults with X-linked hypophosphatemia. Successful correction of complex, multiapical bone deformities found in patients with X-linked hypophosphatemia is possible with careful surgical planning and exacting surgical technique. Multiple methods of deformity correction are used, including acute and gradual correction. Treatment of some pediatric bony deformity with guided growth techniques may be possible. Copyright 2015 by the American Academy of Orthopaedic Surgeons.

Deletion of the X-linked opsin gene array locus control region (LCR) results in disruption of the cone mosaic.

PubMed

Carroll, Joseph; Rossi, Ethan A; Porter, Jason; Neitz, Jay; Roorda, Austin; Williams, David R; Neitz, Maureen

2010-09-15

Blue cone monochromacy (BCM) is an X-linked condition in which long- (L) and middle- (M) wavelength-sensitive cone function is absent. Due to the X-linked nature of the condition, female carriers are spared from a full manifestation of the associated defects but can show visual symptoms, including abnormal cone electroretinograms. Here we imaged the cone mosaic in four females carrying an L/M array with deletion of the locus control region, resulting in an absence of L/M opsin gene expression (effectively acting as a cone opsin knockout). On average, they had cone mosaics with reduced density and disrupted organization compared to normal trichromats. This suggests that the absence of opsin in a subset of cones results in their early degeneration, with X-inactivation the likely mechanism underlying phenotypic variability in BCM carriers. Copyright 2010 Elsevier Ltd. All rights reserved.

Combination of a Haploidentical Stem Cell Transplant With Umbilical Cord Blood for Cerebral X-Linked Adrenoleukodystrophy.

PubMed

Jiang, Hua; Jiang, Min-Yan; Liu, Sha; Cai, Yan-Na; Liang, Cui-Li; Liu, Li

2015-08-01

Childhood cerebral X-linked adrenoleukodystrophy is a rapidly progressive neurodegenerative disorder that affects central nervous system myelin and the adrenal cortex. Hematopoietic stem cell transplantation is the best available curative therapy if performed during the early stages of disease. Only 30% of patients who might benefit from a hematopoietic stem cell transplant will have a full human leukocyte antigen-matched donor, which is considered to be the best choice. We present a 5-year-old boy with cerebral X-linked adrenoleukodystrophy whose brain magnetic resonance imaging severity score was 7 and who needed an immediate transplantation without an available full human leukocyte antigen-matched donor. We combined haploidentical and umbilical cord blood sources for transplantation and saw encouraging results. After transplantation, the patient showed neurological stability for 6 months and the level of very long chain fatty acids had decreased. By 1 year, the patient appeared to gradually develop cognition, motor, and visual disturbances resulting from possible mix chimerism. Transplantation of haploidentical stem cells combined with the infusion of umbilical cord blood is a novel approach for treating cerebral X-linked adrenoleukodystrophy. It is critical to monitor posttransplant chimerism and carry out antirejection therapy timely for a beneficial clinical outcome. Copyright © 2015 Elsevier Inc. All rights reserved.

Genetics Home Reference: immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome

MedlinePlus

... Health Conditions IPEX syndrome Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome Printable PDF Open All Close All ... expand/collapse boxes. Description Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome primarily affects males and is ...

Sudden visual loss after cardiac resynchronization therapy device implantation.

PubMed

De Vitis, Luigi A; Marchese, Alessandro; Giuffrè, Chiara; Carnevali, Adriano; Querques, Lea; Tomasso, Livia; Baldin, Giovanni; Maestranzi, Gisella; Lattanzio, Rosangela; Querques, Giuseppe; Bandello, Francesco

2017-03-10

To report a case of sudden decrease in visual acuity possibly due to a cardiogenic embolism in a patient who underwent cardiac resynchronization therapy (CRT) device implantation. A 62-year-old man with severe left ventricular systolic dysfunction and a left bundle branch block was referred to our department because of a sudden decrease in visual acuity. Nine days earlier, he had undergone cardiac transapical implantation of a CRT device, which was followed, 2 days later, by an inflammatory reaction. The patient underwent several general and ophthalmologic examinations, including multimodal imaging. At presentation, right eye (RE) best-corrected visual acuity (BCVA) was counting fingers and RE pupil was hyporeactive. Fundus examination revealed white-centered hemorrhagic dots suggestive of Roth spots. Fluorescein angiography showed delay in vascular perfusion during early stage, late hyperfluorescence of the macula and optic disk, and peripheral perivascular leakage. The first visual field test showed complete loss of vision RE and a normal left eye. Due to suspected giant cell arteritis, temporal artery biopsy was performed. Thirty minutes after the procedure, an ischemic stroke with right hemisyndrome and aphasia occurred. The RE BCVA worsened to hands motion. Four months later, RE BCVA did not improve, despite improvement in fluorescein angiography inflammatory sign. We report a possible cardiogenic embolism secondary to undiagnosed infective endocarditis causing monocular visual loss after CRT device implantation. It remains unclear how the embolus caused severe functional damage without altering the retinal anatomical structure.

Detection of Visual Field Loss in Pituitary Disease: Peripheral Kinetic Versus Central Static

PubMed Central

Rowe, Fiona J.; Cheyne, Christopher P.; García-Fiñana, Marta; Noonan, Carmel P.; Howard, Claire; Smith, Jayne; Adeoye, Joanne

2015-01-01

Abstract Visual field assessment is an important clinical evaluation for eye disease and neurological injury. We evaluated Octopus semi-automated kinetic peripheral perimetry (SKP) and Humphrey static automated central perimetry for detection of neurological visual field loss in patients with pituitary disease. We carried out a prospective cross-sectional diagnostic accuracy study comparing Humphrey central 30-2 SITA threshold programme with a screening protocol for SKP on Octopus perimetry. Humphrey 24-2 data were extracted from 30-2 results. Results were independently graded for presence/absence of field defect plus severity of defect. Fifty patients (100 eyes) were recruited (25 males and 25 females), with mean age of 52.4 years (SD = 15.7). Order of perimeter assessment (Humphrey/Octopus first) and order of eye tested (right/left first) were randomised. The 30-2 programme detected visual field loss in 85%, the 24-2 programme in 80%, and the Octopus combined kinetic/static strategy in 100% of eyes. Peripheral visual field loss was missed by central threshold assessment. Qualitative comparison of type of visual field defect demonstrated a match between Humphrey and Octopus results in 58%, with a match for severity of defect in 50%. Tests duration was 9.34 minutes (SD = 2.02) for Humphrey 30-2 versus 10.79 minutes (SD = 4.06) for Octopus perimetry. Octopus semi-automated kinetic perimetry was found to be superior to central static testing for detection of pituitary disease-related visual field loss. Where reliant on Humphrey central static perimetry, the 30-2 programme is recommended over the 24-2 programme. Where kinetic perimetry is available, this is preferable to central static programmes for increased detection of peripheral visual field loss. PMID:27928344

Visual and proprioceptive interaction in patients with bilateral vestibular loss.

PubMed

Cutfield, Nicholas J; Scott, Gregory; Waldman, Adam D; Sharp, David J; Bronstein, Adolfo M

2014-01-01

Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular

X-linked hypophosphatemia attributable to pseudoexons of the PHEX gene.

PubMed

Christie, P T; Harding, B; Nesbit, M A; Whyte, M P; Thakker, R V

2001-08-01

X-linked hypophosphatemia is commonly caused by mutations of the coding region of PHEX (phosphate-regulating gene with homologies to endopeptidases on the X chromosome). However, such PHEX mutations are not detected in approximately one third of X-linked hypophosphatemia patients who may harbor defects in the noncoding or intronic regions. We have therefore investigated 11 unrelated X-linked hypophosphatemia patients in whom coding region mutations had been excluded, for intronic mutations that may lead to mRNA splicing abnormalities, by the use of lymphoblastoid RNA and RT-PCRs. One X-linked hypophosphatemia patient was found to have 3 abnormally large transcripts, resulting from 51-bp, 100-bp, and 170-bp insertions, all of which would lead to missense peptides and premature termination codons. The origin of these transcripts was a mutation (g to t) at position +1268 of intron 7, which resulted in the occurrence of a high quality novel donor splice site (ggaagg to gtaagg). Splicing between this novel donor splice site and 3 preexisting, but normally silent, acceptor splice sites within intron 7 resulted in the occurrences of the 3 pseudoexons. This represents the first report of PHEX pseudoexons and reveals further the diversity of genetic abnormalities causing X-linked hypophosphatemia.

Autosomal-recessive and X-linked forms of hereditary motor and sensory neuropathy in childhood.

PubMed

Ouvrier, Robert; Geevasingha, Nimeshan; Ryan, Monique M

2007-08-01

The hereditary motor and sensory neuropathies (HMSNs, Charcot-Marie-Tooth neuropathies) are the most common degenerative disorders of the peripheral nervous system. In recent years a dramatic expansion has occurred in our understanding of the molecular basis and cell biology of the recessively inherited demyelinating and axonal neuropathies, with delineation of a number of new neuropathies. Mutations in some genes cause a wide variety of clinical, neurophysiologic, and pathologic phenotypes, rendering diagnosis difficult. The X-linked forms of HMSN represent at least 10%-15% of all HMSNs and have an expanded disease spectrum including demyelinating, intermediate, and axonal neuropathies, transient central nervous system (CNS) dysfunction, mental retardation, and hearing loss. This review presents an overview of the recessive and X-linked forms of HMSN observed in childhood, with particular reference to disease phenotype and neurophysiologic and pathologic abnormalities suggestive of specific diagnoses. These findings can be used by the clinician to formulate a differential diagnosis and guide targeted genetic testing.

Prevalence and Causes of Visual Loss Among the Indigenous Peoples of the World: A Systematic Review.

PubMed

Foreman, Joshua; Keel, Stuart; van Wijngaarden, Peter; Bourne, Rupert A; Wormald, Richard; Crowston, Jonathan; Taylor, Hugh R; Dirani, Mohamed

2018-05-01

Studies have documented a higher disease burden in indigenous compared with nonindigenous populations, but no global data on the epidemiology of visual loss in indigenous peoples are available. A systematic review of literature on visual loss in the world's indigenous populations could identify major gaps and inform interventions to reduce their burden of visual loss. To conduct a systematic review on the prevalence and causes of visual loss among the world's indigenous populations. A search of databases and alternative sources identified literature on the prevalence and causes of visual loss (visual impairment and blindness) and eye diseases in indigenous populations. Studies from January 1, 1990, through August 1, 2017, that included clinical eye examinations of indigenous participants and, where possible, compared findings with those of nonindigenous populations were included. Methodologic quality of studies was evaluated to reveal gaps in the literature. Limited data were available worldwide. A total of 85 articles described 64 unique studies from 24 countries that examined 79 598 unique indigenous participants. Nineteen studies reported comparator data on 42 085 nonindigenous individuals. The prevalence of visual loss was reported in 13 countries, with visual impairment ranging from 0.6% in indigenous Australian children to 48.5% in native Tibetans 50 years or older. Uncorrected refractive error was the main cause of visual impairment (21.0%-65.1%) in 5 of 6 studies that measured presenting visual acuity. Cataract was the main cause of visual impairment in all 6 studies measuring best-corrected acuity (25.4%-72.2%). Cataract was the leading cause of blindness in 13 studies (32.0%-79.2%), followed by uncorrected refractive error in 2 studies (33.0% and 35.8%). Most countries with indigenous peoples do not have data on the burden of visual loss in these populations. Although existing studies vary in methodologic quality and reliability, they suggest that most

Color-Space-Based Visual-MIMO for V2X Communication †

PubMed Central

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-01-01

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance. PMID:27120603

Visual loss in a school for the blind in Nigeria.

PubMed

Okoye, O I; Aghaji, A E; Ikojo, I N

2009-01-01

There are an estimated 1.4 million blind children worldwide, it has been observed that almost 90% of the so-called blind population (children inclusive) do not have total loss of visual function, but retain a degree of usable residual vision. The study aims to determined the sites and causes of visual loss in the students of a school for the blind in Nigeria, and also the proportion of those students who could benefit from low vision devices. Forty-five students of the school were examined using the standard World Health Organization/Prevention of blindness examination record for childhood blindness. Refraction and assessment for low vision devices were conducted, where necessary. Glaucoma/buphthalmos (22.2%) and corneal lesions (20%) were the major causes of vision loss. Six students (13.3%) benefited from spectacles and/or low vision devices. Glaucoma/buphthalmos is assuming great significance in this study population, though most of the causes of vision loss are avoidable (77.7%). There is need for low vision service in the schools for the blind in South East Nigeria.

Are Deaf Students Visual Learners?

ERIC Educational Resources Information Center

Marschark, Marc; Morrison, Carolyn; Lukomski, Jennifer; Borgna, Georgianna; Convertino, Carol

2013-01-01

It is frequently assumed that by virtue of their hearing losses, deaf students are visual learners. Deaf individuals have some visual-spatial advantages relative to hearing individuals, but most have been linked to use of sign language rather than auditory deprivation. How such cognitive differences might affect academic performance has been…

Impaired plasticity of macrophages in X-linked adrenoleukodystrophy.

PubMed

Weinhofer, Isabelle; Zierfuss, Bettina; Hametner, Simon; Wagner, Magdalena; Popitsch, Niko; Machacek, Christian; Bartolini, Barbara; Zlabinger, Gerhard; Ohradanova-Repic, Anna; Stockinger, Hannes; Köhler, Wolfgang; Höftberger, Romana; Regelsberger, Günther; Forss-Petter, Sonja; Lassmann, Hans; Berger, Johannes

2018-05-30

X-linked adrenoleukodystrophy is caused by ATP-binding cassette transporter D1 (ABCD1) mutations and manifests by default as slowly progressive spinal cord axonopathy with associated demyelination (adrenomyloneuropathy). In 60% of male cases, however, X-linked adrenoleukodystrophy converts to devastating cerebral inflammation and demyelination (cerebral adrenoleukodystrophy) with infiltrating blood-derived monocytes and macrophages and cytotoxic T cells that can only be stopped by allogeneic haematopoietic stem cell transplantation or gene therapy at an early stage of the disease. Recently, we identified monocytes/macrophages but not T cells to be severely affected metabolically by ABCD1 deficiency. Here we found by whole transcriptome analysis that, although monocytes of patients with X-linked adrenoleukodystrophy have normal capacity for macrophage differentiation and phagocytosis, they are pro-inflammatory skewed also in patients with adrenomyloneuropathy in the absence of cerebral inflammation. Following lipopolysaccharide activation, the ingestion of myelin debris, normally triggering anti-inflammatory polarization, did not fully reverse the pro-inflammatory status of X-linked adrenoleukodystrophy macrophages. Immunohistochemistry on post-mortem cerebral adrenoleukodystrophy lesions reflected the activation pattern by prominent presence of enlarged lipid-laden macrophages strongly positive for the pro-inflammatory marker co-stimulatory molecule CD86. Comparative analyses of lesions with matching macrophage density in cases of cerebral adrenoleukodystrophy and acute multiple sclerosis showed a similar extent of pro-inflammatory activation but a striking reduction of anti-inflammatory mannose receptor (CD206) and haemoglobin-haptoglobin receptor (CD163) expression on cerebral adrenoleukodystrophy macrophages. Accordingly, ABCD1-deficiency leads to an impaired plasticity of macrophages that is reflected in incomplete establishment of anti-inflammatory responses

Genetics Home Reference: X-linked spondyloepiphyseal dysplasia tarda

MedlinePlus

... Educational Resources (6 links) Cincinnati Children's Hospital: Coxa Vera Disease InfoSearch: Spondyloepiphyseal dysplasia tarda X-linked Johns ... Free article on PubMed Central Savarirayan R, Thompson E, Gécz J. Spondyloepiphyseal dysplasia tarda (SEDL, MIM #313400). ...

Fragile X Mental Retardation Protein Is Required to Maintain Visual Conditioning-Induced Behavioral Plasticity by Limiting Local Protein Synthesis

PubMed Central

Liu, Han-Hsuan

2016-01-01

Fragile X mental retardation protein (FMRP) is thought to regulate neuronal plasticity by limiting dendritic protein synthesis, but direct demonstration of a requirement for FMRP control of local protein synthesis during behavioral plasticity is lacking. Here we tested whether FMRP knockdown in Xenopus optic tectum affects local protein synthesis in vivo and whether FMRP knockdown affects protein synthesis-dependent visual avoidance behavioral plasticity. We tagged newly synthesized proteins by incorporation of the noncanonical amino acid azidohomoalanine and visualized them with fluorescent noncanonical amino acid tagging (FUNCAT). Visual conditioning and FMRP knockdown produce similar increases in FUNCAT in tectal neuropil. Induction of visual conditioning-dependent behavioral plasticity occurs normally in FMRP knockdown animals, but plasticity degrades over 24 h. These results indicate that FMRP affects visual conditioning-induced local protein synthesis and is required to maintain the visual conditioning-induced behavioral plasticity. SIGNIFICANCE STATEMENT Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. Exaggerated dendritic protein synthesis resulting from loss of fragile X mental retardation protein (FMRP) is thought to underlie cognitive deficits in FXS, but no direct evidence has demonstrated that FMRP-regulated dendritic protein synthesis affects behavioral plasticity in intact animals. Xenopus tadpoles exhibit a visual avoidance behavior that improves with visual conditioning in a protein synthesis-dependent manner. We showed that FMRP knockdown and visual conditioning dramatically increase protein synthesis in neuronal processes. Furthermore, induction of visual conditioning-dependent behavioral plasticity occurs normally after FMRP knockdown, but performance rapidly deteriorated in the absence of FMRP. These studies show that FMRP negatively regulates local protein synthesis and is required to maintain visual

Experience and information loss in auditory and visual memory.

PubMed

Gloede, Michele E; Paulauskas, Emily E; Gregg, Melissa K

2017-07-01

Recent studies show that recognition memory for sounds is inferior to memory for pictures. Four experiments were conducted to examine the nature of auditory and visual memory. Experiments 1-3 were conducted to evaluate the role of experience in auditory and visual memory. Participants received a study phase with pictures/sounds, followed by a recognition memory test. Participants then completed auditory training with each of the sounds, followed by a second memory test. Despite auditory training in Experiments 1 and 2, visual memory was superior to auditory memory. In Experiment 3, we found that it is possible to improve auditory memory, but only after 3 days of specific auditory training and 3 days of visual memory decay. We examined the time course of information loss in auditory and visual memory in Experiment 4 and found a trade-off between visual and auditory recognition memory: Visual memory appears to have a larger capacity, while auditory memory is more enduring. Our results indicate that visual and auditory memory are inherently different memory systems and that differences in visual and auditory recognition memory performance may be due to the different amounts of experience with visual and auditory information, as well as structurally different neural circuitry specialized for information retention.

Exploring the Link between Visual Perception, Visual-Motor Integration, and Reading in Normal Developing and Impaired Children using DTVP-2.

PubMed

Bellocchi, Stéphanie; Muneaux, Mathilde; Huau, Andréa; Lévêque, Yohana; Jover, Marianne; Ducrot, Stéphanie

2017-08-01

Reading is known to be primarily a linguistic task. However, to successfully decode written words, children also need to develop good visual-perception skills. Furthermore, motor skills are implicated in letter recognition and reading acquisition. Three studies have been designed to determine the link between reading, visual perception, and visual-motor integration using the Developmental Test of Visual Perception version 2 (DTVP-2). Study 1 tests how visual perception and visual-motor integration in kindergarten predict reading outcomes in Grade 1, in typical developing children. Study 2 is aimed at finding out if these skills can be seen as clinical markers in dyslexic children (DD). Study 3 determines if visual-motor integration and motor-reduced visual perception can distinguish DD children according to whether they exhibit or not developmental coordination disorder (DCD). Results showed that phonological awareness and visual-motor integration predicted reading outcomes one year later. DTVP-2 demonstrated similarities and differences in visual-motor integration and motor-reduced visual perception between children with DD, DCD, and both of these deficits. DTVP-2 is a suitable tool to investigate links between visual perception, visual-motor integration and reading, and to differentiate cognitive profiles of children with developmental disabilities (i.e. DD, DCD, and comorbid children). Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

siRNAs from an X-linked satellite repeat promote X-chromosome recognition in Drosophila melanogaster.

PubMed

Menon, Debashish U; Coarfa, Cristian; Xiao, Weimin; Gunaratne, Preethi H; Meller, Victoria H

2014-11-18

Highly differentiated sex chromosomes create a lethal imbalance in gene expression in one sex. To accommodate hemizygosity of the X chromosome in male fruit flies, expression of X-linked genes increases twofold. This is achieved by the male- specific lethal (MSL) complex, which modifies chromatin to increase expression. Mutations that disrupt the X localization of this complex decrease the expression of X-linked genes and reduce male survival. The mechanism that restricts the MSL complex to X chromatin is not understood. We recently reported that the siRNA pathway contributes to localization of the MSL complex, raising questions about the source of the siRNAs involved. The X-linked 1.688 g/cm(3) satellite related repeats (1.688(X) repeats) are restricted to the X chromosome and produce small RNA, making them an attractive candidate. We tested RNA from these repeats for a role in dosage compensation and found that ectopic expression of single-stranded RNAs from 1.688(X) repeats enhanced the male lethality of mutants with defective X recognition. In contrast, expression of double-stranded hairpin RNA from a 1.688(X) repeat generated abundant siRNA and dramatically increased male survival. Consistent with improved survival, X localization of the MSL complex was largely restored in these males. The striking distribution of 1.688(X) repeats, which are nearly exclusive to the X chromosome, suggests that these are cis-acting elements contributing to identification of X chromatin.

Diving-related visual loss in the setting of angioid streaks: report of two cases.

PubMed

Angulo Bocco, Maria I; Spielberg, Leigh; Coppens, Greet; Catherine, Janet; Verougstraete, Claire; Leys, Anita M

2012-01-01

The purpose of this study was to report diving-related visual loss in the setting of angioid streaks. Observational case reports of two patients with angioid streaks suffering sudden visual loss immediately after diving. Two young adult male patients presented with visual loss after diving headfirst. Funduscopy revealed angioid streaks, peau d'orange, subretinal hemorrhages, and ruptures of Bruch membrane. Choroidal neovascularization developed during follow-up. Both patients had an otherwise uneventful personal and familial medical history. In patients with angioid streaks, diving headfirst can lead to subretinal hemorrhages and traumatic ruptures in Bruch membrane and increase the risk of maculopathy. Ophthalmologists should caution patients with angioid streaks against diving headfirst.

Genetics Home Reference: X-linked agammaglobulinemia

MedlinePlus

... Sep;104(3):221-30. Citation on PubMed Smith CIE, Berglöf A. X-Linked Agammaglobulinemia. 2001 Apr ... Bean LJH, Bird TD, Ledbetter N, Mefford HC, Smith RJH, Stephens K, editors. GeneReviews® [Internet]. Seattle (WA): ...

Severe manifestations in carrier females in X linked retinitis pigmentosa.

PubMed Central

Souied, E; Segues, B; Ghazi, I; Rozet, J M; Chatelin, S; Gerber, S; Perrault, I; Michel-Awad, A; Briard, M L; Plessis, G; Dufier, J L; Munnich, A; Kaplan, J

1997-01-01

Retinitis pigmentosa (RP) is a group of progressive hereditary disorders of the retina in which various modes of inheritance have been described. Here, we report on X linked RP in nine families with constant and severe expression in carrier females. In our series, however, the phenotype was milder and delayed in carrier females compared to hemizygous males. This form of X linked RP could be regarded therefore as partially dominant. The disease gene maps to chromosome Xp2.1 in the genetic interval encompassing the RP3 locus (Zmax=13.71 at the DXS1100 locus). Single strand conformation polymorphism and direct sequence analysis of the retinitis pigmentosa GTPase regulator (RPGR) gene, which accounts for RP3, failed to detect any mutation in our families. Future advances in the identification of X linked RP genes will hopefully help to elucidate the molecular basis of this X linked dominant RP. Images PMID:9350809

Analysis of Anatomic and Functional Measures in X-Linked Retinoschisis

PubMed Central

Cukras, Catherine A.; Huryn, Laryssa A.; Jeffrey, Brett P.; Turriff, Amy; Sieving, Paul A.

2018-01-01

Purpose To examine the symmetry of structural and functional parameters between eyes in patients with X-linked retinoschisis (XLRS), as well as changes in visual acuity and electrophysiology over time. Methods This is a single-center observational study of 120 males with XLRS who were evaluated at the National Eye Institute. Examinations included best-corrected visual acuity for all participants, as well as ERG recording and optical coherence tomography (OCT) on a subset of participants. Statistical analyses were performed using nonparametric Spearman correlations and linear regression. Results Our analyses demonstrated a statistically significant correlation of structural and functional measures between the two eyes of XLRS patients for all parameters. OCT central macular thickness (n = 78; Spearman r = 0.83, P < 0.0001) and ERG b/a ratio (n = 78; Spearman r = 0.82, P < 0.0001) were the most strongly correlated between a participant's eyes, whereas visual acuity was less strongly correlated (n = 120; Spearman r = 0.47, P < 0.0001). Stability of visual acuity was observed with an average change of less than one letter (n = 74; OD −0.66 and OS −0.70 letters) in a mean follow-up time of 6.8 years. There was no statistically significant change in the ERG b/a ratio within eyes over time. Conclusions Although a broad spectrum of clinical phenotypes is observed across individuals with XLRS, our study demonstrates a significant correlation of structural and functional findings between the two eyes and stability of measures of acuity and ERG parameters over time. These results highlight the utility of the fellow eye as a useful reference for monocular interventional trials.

Autoimmune retinopathy with RPE hypersensitivity and 'negative ERG' in X-linked hyper-IgM syndrome.

PubMed

Schuster, Andreas; Apfelstedt-Sylla, Eckart; Pusch, Carsten M; Zrenner, Eberhart; Thirkill, Charles E

2005-01-01

To report the clinical, electrophysiological, and immunological features of a patient with X-linked hyper-IgM immunodeficiency syndrome type 1 (HIGM1) accompanied by a novel type of autoimmune retinopathy, including retinal pigment epithelium (RPE) hypersensitivity. Comprehensive ophthalmological examinations, electrophysiological function testing, and inquiries into the immunological status of a 13-year-old presenting with subacute loss of vision in association with a molecularly confirmed diagnosis of HIGM1 were performed. The patient was genotyped by a PCR-based sequence tag content mapping strategy to define the genetic defect within the causative X-HIM gene TNFSF5. Since conventional allogenic bone marrow transplantation has been reported to cure HIGM1, a peripheral blood stem-cell transplantation was performed. (1) The patient's reduced visual acuity included prolonged dark adaptation and visual field constriction. Electrophysiology revealed a 'negative ERG' indicating post-receptoral dysfunction. (2) Initial immunological examination of the patient's serum identified abnormal antibody activity with components of the photoreceptors and the inner nuclear layer. The patient later developed indications of RPE hypersensitivity. A massively reduced light-peak to dark-trough ratio of the EOG slow oscillations (L/D ratio) corresponded to impaired RPE-photoreceptor complex function. (3) Molecular genetic analyses revealed the patient to be nullizygous for the tumor necrosis factor ligand member 5 gene (TNFSF5; CD40LG). A large chromosomal deletion of approximately 27.6-32.3 kb in size was identified in Xq26. (4) The transplant with its associated immunomodulation appeared to worsen rather than improve the patient's condition. The fundus appearance and electrophysiological function testing revealed indications of atypical retinal degeneration. However, the clinical course and the serological findings were consistent with those of ocular autoimmunity involving both

How does glaucoma look?: patient perception of visual field loss.

PubMed

Crabb, David P; Smith, Nicholas D; Glen, Fiona C; Burton, Robyn; Garway-Heath, David F

2013-06-01

To explore patient perception of vision loss in glaucoma and, specifically, to test the hypothesis that patients do not recognize their impairment as a black tunnel effect or as black patches in their field of view. Clinic-based cross-sectional study. Fifty patients (age range, 52-82 years) with visual acuity better than 20/30 and with a range of glaucomatous visual field (VF) defects in both eyes, excluding those with very advanced disease (perimetrically blind). Participants underwent monocular VF testing in both eyes using a Humphrey Field Analyzer (HFA; Carl Zeiss Meditec, Dublin, CA; 24-2 Swedish interactive threshold algorithm standard tests) and other tests of visual function. Participants took part in a recorded interview during which they were asked if they were aware of their VF loss; if so, there were encouraged to describe it in their own words. Participants were shown 6 images modified in a variety of ways on a computer monitor and were asked to select the image that most closely represented their perception of their VF loss. Forced choice of an image best representing glaucomatous vision impairment. Participants had a range of VF defect severity: average HFA mean deviation was -8.7 dB (standard deviation [SD], 5.8 dB) and -10.5 dB (SD, 7.1 dB) in the right and left eyes, respectively. Thirteen patients (26%; 95% confidence interval [CI], 15%-40%) reported being completely unaware of their vision loss. None of the patients chose the images with a distinct black tunnel effect or black patches. Only 2 patients (4%; 95% CI, 0%-14%) chose the image with a tunnel effect with blurred edges. An image depicting blurred patches and another with missing patches was chosen by 54% (95% CI, 39%-68%) and 16% (95% CI, 7%-29%) of the patients, respectively. Content analysis of the transcripts from the recorded interviews indicated a frequent use of descriptors of visual symptoms associated with reported blur and missing features. Patients with glaucoma do not perceive

X-linked hypophosphataemia: a homologous disorder in humans and mice.

PubMed

Tenenhouse, H S

1999-02-01

X-linked hypophosphatemia is an inherited disorder of phosphate (Pi) homeostasis characterized by growth retardation, rickets and osteomalacia, hypophosphataemia, and aberrant renal Pi reabsorption and vitamin D metabolism. Studies in murine Hyp and Gy homologues have identified a specific defect in Na+-Pi cotransport at the brush border membrane, abnormal regulation of 1,25-dihydroxyvitamin D3 (1,25(OH)2D) synthesis and degradation, and an intrinsic defect in bone mineralization. The mutant gene has been identified in XLH patients, by positional cloning, and in Hyp and Gy mice, and was designated PHEX/Phex to signify a PHosphate-regulating gene with homology to Endopeptidases on the X chromosome. PHEX/Phex is expressed in bones and teeth but not in kidney and efforts are under way to elucidate how loss of PHEX/Phex function elicits the mutant phenotype. Based on its homology to endopeptidases, it is postulated that PHEX/Phex is involved in the activation or inactivation of a peptide hormone(s) which plays a key role in the regulation of bone mineralization, renal Pi handling and vitamin D metabolism.

Fragile X Mental Retardation Protein Is Required to Maintain Visual Conditioning-Induced Behavioral Plasticity by Limiting Local Protein Synthesis.

PubMed

Liu, Han-Hsuan; Cline, Hollis T

2016-07-06

Fragile X mental retardation protein (FMRP) is thought to regulate neuronal plasticity by limiting dendritic protein synthesis, but direct demonstration of a requirement for FMRP control of local protein synthesis during behavioral plasticity is lacking. Here we tested whether FMRP knockdown in Xenopus optic tectum affects local protein synthesis in vivo and whether FMRP knockdown affects protein synthesis-dependent visual avoidance behavioral plasticity. We tagged newly synthesized proteins by incorporation of the noncanonical amino acid azidohomoalanine and visualized them with fluorescent noncanonical amino acid tagging (FUNCAT). Visual conditioning and FMRP knockdown produce similar increases in FUNCAT in tectal neuropil. Induction of visual conditioning-dependent behavioral plasticity occurs normally in FMRP knockdown animals, but plasticity degrades over 24 h. These results indicate that FMRP affects visual conditioning-induced local protein synthesis and is required to maintain the visual conditioning-induced behavioral plasticity. Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. Exaggerated dendritic protein synthesis resulting from loss of fragile X mental retardation protein (FMRP) is thought to underlie cognitive deficits in FXS, but no direct evidence has demonstrated that FMRP-regulated dendritic protein synthesis affects behavioral plasticity in intact animals. Xenopus tadpoles exhibit a visual avoidance behavior that improves with visual conditioning in a protein synthesis-dependent manner. We showed that FMRP knockdown and visual conditioning dramatically increase protein synthesis in neuronal processes. Furthermore, induction of visual conditioning-dependent behavioral plasticity occurs normally after FMRP knockdown, but performance rapidly deteriorated in the absence of FMRP. These studies show that FMRP negatively regulates local protein synthesis and is required to maintain visual conditioning

Localization to Xq22 and clinical update of a family with X-linked recessive mental retardation with progression sensorineural deafness, progressive tapeto-retinal degeneration and dystonia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tranebjaerg, L.; Schwartz, C.; Huggins, K.

1994-07-15

In a reinvestigation of a six-generation Norwegian family, originally reported with non-syndromic X-linked recessive deafness by Mohr and Mageroy, we have demonstrated several syndromic manifestations. The 10 clinically characterized affected males range in age from 14-61 years, and show progressive mental deterioration and visual disability. Ophthalmological and electrophysiological studies showed myopia, decreased visual acuity, combined cone-rod dystrophy as well as central areolar dystrophy by means of ERG. Brain CT-scans showed cortical and central atrophy without predilection to specific areas. Linkage analysis, using X-chromosomal RFLPs and CA-repeats, yielded a maximum LOD score of 4.37 with linkage to DXS17. DXS17 is localizedmore » to Xq22. One recombinant with COL4A5 (deficient in Alport syndrome) was observed. Results from the studies of this family will be important in reclassification of non-syndromic X-linked deafness since the family now represents syndromic deafness and XLMR with a specific phenotype.« less

X linked mental retardation: a clinical guide.

PubMed

Raymond, F L

2006-03-01

Mental retardation is more common in males than females in the population, assumed to be due to mutations on the X chromosome. The prevalence of the 24 genes identified to date is low and less common than expansions in FMR1, which cause Fragile X syndrome. Systematic screening of all other X linked genes in X linked families with mental retardation is currently not feasible in a clinical setting. The phenotypes of genes causing syndromic and non-syndromic mental retardation (NLGN3, NLGN4, RPS6KA3(RSK2), OPHN1, ATRX, SLC6A8, ARX, SYN1, AGTR2, MECP2, PQBP1, SMCX, and SLC16A2) are first discussed, as these may be the focus of more targeted mutation analysis. Secondly, the relative prevalence of genes causing only non-syndromic mental retardation (IL1RAPL1, TM4SF2, ZNF41, FTSJ1, DLG3, FACL4, PAK3, ARHGEF6, FMR2, and GDI) is summarised. Thirdly, the problem of recurrence risk where a molecular genetics diagnosis has not been made and what proportion of the male excess of mental retardation is due to monogenic disorders of the X chromosome are discussed.

Molecular characterization of a novel X-linked syndrome involving developmental delay and deafness.

PubMed

Hildebrand, Michael S; de Silva, Michelle G; Tan, Tiong Yang; Rose, Elizabeth; Nishimura, Carla; Tolmachova, Tanya; Hulett, Joanne M; White, Susan M; Silver, Jeremy; Bahlo, Melanie; Smith, Richard J H; Dahl, Hans-Henrik M

2007-11-01

X-linked syndromes associated with developmental delay and sensorineural hearing loss (SNHL) have been characterized at the molecular level, including Mohr-Tranebjaerg syndrome and Norrie disease. In this study we report on a novel X-linked recessive, congenital syndrome in a family with developmental delay and SNHL that maps to a locus associated with mental retardation (MR) for which no causative gene has been identified. The X-linked recessive inheritance and congenital nature of the syndrome was confirmed by detailed clinical investigation and the family history. Linkage mapping of the X-chromosome was conducted to ascertain the disease locus and candidate genes were screened by direct sequencing and STRP analysis. The recessive syndrome was mapped to Xp11.3-q21.32 and a deletion was identified in a regulatory region upstream of the POU3F4 gene in affected family members. Since mutations in POU3F4 cause deafness at the DFN3 locus, the deletion is the likely cause of the SNHL in this family. The choroideremia (CHM) gene was also screened and a novel missense change was identified. The alteration changes the serine residue at position 89 in the Rab escort 1 protein (REP-1) to a cysteine (S89C). Prenylation of Rab proteins was investigated in patients and the location of REP-1 expression in the brain determined. However, subsequent analysis revealed that this change in CHM was polymorphic having no effect on REP-1 function. Although the causative gene at the MR locus in this family has not been identified, there are a number of genes involved in syndromic and nonsyndromic forms of MR that are potential candidates. Copyright 2007 Wiley-Liss, Inc.

A Simulation of X-Linked Inheritance.

ERIC Educational Resources Information Center

Harrell, Pamela Esprivalo

1997-01-01

Describes how to lead students through a classroom-based simulation to teach a variety of concepts such as X-linked traits, sex determination, and sex anomalies. The simulation utilizes inexpensive materials such as plastic eggs that twist apart to represent human eggs and sperm. (AIM)

Escape of X-linked miRNA genes from meiotic sex chromosome inactivation

PubMed Central

Sosa, Enrique; Flores, Luis; Yan, Wei; McCarrey, John R.

2015-01-01

Past studies have indicated that transcription of all X-linked genes is repressed by meiotic sex chromosome inactivation (MSCI) during the meiotic phase of spermatogenesis in mammals. However, more recent studies have shown an increase in steady-state levels of certain X-linked miRNAs in pachytene spermatocytes, suggesting that either synthesis of these miRNAs increases or that degradation of these miRNAs decreases dramatically in these cells. To distinguish between these possibilities, we performed RNA-FISH to detect nascent transcripts from multiple miRNA genes in various spermatogenic cell types. Our results show definitively that Type I X-linked miRNA genes are subject to MSCI, as are all or most X-linked mRNA genes, whereas Type II and III X-linked miRNA genes escape MSCI by continuing ongoing, active transcription in primary spermatocytes. We corroborated these results by co-localization of RNA-FISH signals with both a corresponding DNA-FISH signal and an immunofluorescence signal for RNA polymerase II. We also found that X-linked miRNA genes that escape MSCI locate non-randomly to the periphery of the XY body, whereas genes that are subject to MSCI remain located within the XY body in pachytene spermatocytes, suggesting that the mechanism of escape of X-linked miRNA genes from MSCI involves their relocation to a position outside of the repressive chromatin domain associated with the XY body. The fact that Type II and III X-linked miRNA genes escape MSCI suggests an immediacy of function of the encoded miRNAs specifically required during the meiotic stages of spermatogenesis. PMID:26395485

Screening for X-linked adrenoleukodystrophy among adult men with Addison's disease.

PubMed

Horn, Morten A; Erichsen, Martina M; Wolff, Anette S B; Månsson, Jan-Eric; Husebye, Eystein S; Tallaksen, Chantal M E; Skjeldal, Ola H

2013-09-01

X-linked adrenoleukodystrophy is an important cause of Addison's disease in boys, but less is known about its contribution to Addison's disease in adult men. After surveying all known cases of X-linked adrenoleukodystrophy in Norway in a separate study, we aimed to look for any missed cases among the population of adult men with nonautoimmune Addison's disease. Among 153 adult men identified in a National Registry for Addison's Disease (75% of identified male cases of Addison's disease in Norway), those with negative indices for 21-hydroxylase autoantibodies were selected. Additionally, cases with low autoantibody indices (48-200) were selected. Sera from subjects included were analysed for levels of very long-chain fatty acids, which are diagnostic for X-linked adrenoleukodystrophy in men. Eighteen subjects had negative indices and 17 had low indices for 21-hydroxylase autoantibodies. None of those with low indices and only one of those with negative indices were found to have X-linked adrenoleukodystrophy; this subject had already been diagnosed because of the neurological symptoms. Cases of Addison's disease proved to be caused by X-linked adrenoleukodystrophy constitute 1·5% of all adult male cases in Norway; the proportion among nonautoimmune cases was 15%. We found X-linked adrenoleukodystrophy to be an uncommon cause of Addison's disease in adult men. However, this aetiological diagnosis has far-reaching consequences both for the patient and for his extended family. We therefore recommend that all adult men with nonautoimmune Addison's disease be analysed for levels of very long-chain fatty acids. © 2013 John Wiley & Sons Ltd.

A pleiotropic interaction between vision loss and hypermelanism in Astyanax mexicanus cave x surface hybrids.

PubMed

Gross, Joshua B; Powers, Amanda K; Davis, Erin M; Kaplan, Shane A

2016-06-30

Cave-dwelling animals evolve various traits as a consequence of life in darkness. Constructive traits (e.g., enhanced non-visual sensory systems) presumably arise under strong selective pressures. The mechanism(s) driving regression of features, however, are not well understood. Quantitative trait locus (QTL) analyses in Astyanax mexicanus Pachón cave x surface hybrids revealed phenotypic effects associated with vision and pigmentation loss. Vision QTL were uniformly associated with reductions in the homozygous cave condition, however pigmentation QTL demonstrated mixed phenotypic effects. This implied pigmentation might be lost through both selective and neutral forces. Alternatively, in this report, we examined if a pleiotropic interaction may exist between vision and pigmentation since vision loss has been shown to result in darker skin in other fish and amphibian model systems. We discovered that certain members of Pachón x surface pedigrees are significantly darker than surface-dwelling fish. All of these "hypermelanic" individuals demonstrated severe visual system malformations suggesting they may be blind. A vision-mediated behavioral assay revealed that these fish, in stark contrast to surface fish, behaved the same as blind cavefish. Further, hypermelanic melanophores were larger and more dendritic in morphology compared to surface fish melanophores. However, hypermelanic melanophores responded normally to melanin-concentrating hormone suggesting darkening stemmed from vision loss, rather than a defect in pigment cell function. Finally, a number of genomic regions were coordinately associated with both reduced vision and increased pigmentation. This work suggests hypermelanism in hybrid Astyanax results from blindness. This finding provides an alternative explanation for phenotypic effect studies of pigmentation QTL as stemming (at least in part) from environmental, rather than exclusively genetic, interactions between two regressive phenotypes. Further

Impact of Visual Field Loss on Health-Related Quality of Life in Glaucoma

PubMed Central

McKean-Cowdin, Roberta; Wang, Ying; Wu, Joanne; Azen, Stanley P.; Varma, Rohit

2016-01-01

Purpose To examine the association between health-related quality of life (HRQOL) and visual field (VF) loss in participants with open-angle glaucoma (OAG) in the Los Angeles Latino Eye Study (LALES). Design Population-based cross-sectional study. Participants Two hundred thirteen participants with OAG and 2821 participants without glaucoma or VF loss. Methods Participants in the LALES—a population-based prevalence study of eye disease in Latinos 40 years and older, residing in Los Angeles, California—underwent a detailed eye examination including an assessment of their VF using the Humphrey Automated Field Analyzer (Swedish interactive thresholding algorithm Standard 24-2). Open-angle glaucoma was determined by clinical examination. Mean deviation scores were used to assess severity of VF loss. Health-related QOL was assessed by the Medical Outcomes Study 12-item Short-Form Health Survey (SF-12) and 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). Linear regression and analysis of covariance were used to assess the relationship between HRQOL scores and VF loss after adjusting for sociodemographic variables and visual acuity. Main Outcome Measures The 25-item NEI-VFQ and SF-12 scores. Results A trend of worse NEI-VFQ-25 scores for most subscales was observed with worse VF loss (using both monocular and calculated binocular data). Open-angle glaucoma participants with VF loss had lower scores than participants with no VF loss. This association was also present in participants who were previously undiagnosed and untreated for OAG (N = 160). Participants with any central VF loss had lower NEI-VFQ-25 scores than those with unilateral or bilateral peripheral VF loss. There was no significant impact of severity or location of VF loss on SF-12 scores. Conclusion Greater severity of VF loss in persons with OAG impacts vision-related QOL. This impact was present in persons who were previously unaware that they had glaucoma. Prevention of VF

Genetics Home Reference: X-linked lymphoproliferative disease

MedlinePlus

... infects most humans. In some people it causes infectious mononucleosis (commonly known as "mono"). Normally, after initial infection, ... severe susceptibility to EBV infection severe susceptibility to infectious mononucleosis X-linked lymphoproliferative syndrome XLP Related Information How ...

Auditory, visual, and bimodal data link displays and how they support pilot performance.

PubMed

Steelman, Kelly S; Talleur, Donald; Carbonari, Ronald; Yamani, Yusuke; Nunes, Ashley; McCarley, Jason S

2013-06-01

The design of data link messaging systems to ensure optimal pilot performance requires empirical guidance. The current study examined the effects of display format (auditory, visual, or bimodal) and visual display position (adjacent to instrument panel or mounted on console) on pilot performance. Subjects performed five 20-min simulated single-pilot flights. During each flight, subjects received messages from a simulated air traffic controller. Messages were delivered visually, auditorily, or bimodally. Subjects were asked to read back each message aloud and then perform the instructed maneuver. Visual and bimodal displays engendered lower subjective workload and better altitude tracking than auditory displays. Readback times were shorter with the two unimodal visual formats than with any of the other three formats. Advantages for the unimodal visual format ranged in size from 2.8 s to 3.8 s relative to the bimodal upper left and auditory formats, respectively. Auditory displays allowed slightly more head-up time (3 to 3.5 seconds per minute) than either visual or bimodal displays. Position of the visual display had only modest effects on any measure. Combined with the results from previous studies by Helleberg and Wickens and Lancaster and Casali the current data favor visual and bimodal displays over auditory displays; unimodal auditory displays were favored by only one measure, head-up time, and only very modestly. Data evinced no statistically significant effects of visual display position on performance, suggesting that, contrary to expectations, the placement of a visual data link display may be of relatively little consequence to performance.

[Postoperative visual loss due to conversion disorder after spine surgery: a case report].

PubMed

Bezerra, Dailson Mamede; Bezerra, Eglantine Mamede; Silva Junior, Antonio Jorge; Amorim, Marco Aurélio Soares; Miranda, Denismar Borges de

Patients undergoing spinal surgeries may develop postoperative visual loss. We present a case of total bilateral visual loss in a patient who, despite having clinical and surgical risk factors for organic lesion, evolved with visual disturbance due to conversion disorder. A male patient, 39 years old, 71kg, 1.72 m, ASA I, admitted to undergo fusion and discectomy at L4-L5 and L5-S1. Venoclysis, cardioscopy, oximetry, NIBP; induction with remifentanil, propofol and rocuronium; intubation with ETT (8.0mm) followed by capnography and urinary catheterization for diuresis. Maintenance with full target-controlled intravenous anesthesia. During fixation and laminectomy, the patient developed severe bleeding and hypovolemic shock. After 30minutes, hemostasis and hemodynamic stability was achieved with infusion of norepinephrine, volume expansion, and blood products. In the ICU, the patient developed mental confusion, weakness in the limbs, and bilateral visual loss. It was not possible to identify clinical, laboratory or image findings of organic lesion. He evolved with episodes of anxiety, emotional lability, and language impairment; the hypothesis of conversion syndrome with visual component was raised after psychiatric evaluation. The patient had complete resolution of symptoms after visual education and introduction of low doses of antipsychotic, antidepressant, and benzodiazepine. Other symptoms also regressed, and the patient was discharged 12 days after surgery. After 60 days, the patient had no more symptoms. Conversion disorders may have different signs and symptoms of non-organic origin, including visual component. It is noteworthy that the occurrence of this type of visual dysfunction in the postoperative period of spinal surgery is a rare event and should be remembered as a differential diagnosis. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Visualizing weighted networks: a performance comparison of adjacency matrices versus node-link diagrams

NASA Astrophysics Data System (ADS)

McIntire, John P.; Osesina, O. Isaac; Bartley, Cecilia; Tudoreanu, M. Eduard; Havig, Paul R.; Geiselman, Eric E.

2012-06-01

Ensuring the proper and effective ways to visualize network data is important for many areas of academia, applied sciences, the military, and the public. Fields such as social network analysis, genetics, biochemistry, intelligence, cybersecurity, neural network modeling, transit systems, communications, etc. often deal with large, complex network datasets that can be difficult to interact with, study, and use. There have been surprisingly few human factors performance studies on the relative effectiveness of different graph drawings or network diagram techniques to convey information to a viewer. This is particularly true for weighted networks which include the strength of connections between nodes, not just information about which nodes are linked to other nodes. We describe a human factors study in which participants performed four separate network analysis tasks (finding a direct link between given nodes, finding an interconnected node between given nodes, estimating link strengths, and estimating the most densely interconnected nodes) on two different network visualizations: an adjacency matrix with a heat-map versus a node-link diagram. The results should help shed light on effective methods of visualizing network data for some representative analysis tasks, with the ultimate goal of improving usability and performance for viewers of network data displays.

Effects of sensorineural hearing loss on visually guided attention in a multitalker environment.

PubMed

Best, Virginia; Marrone, Nicole; Mason, Christine R; Kidd, Gerald; Shinn-Cunningham, Barbara G

2009-03-01

This study asked whether or not listeners with sensorineural hearing loss have an impaired ability to use top-down attention to enhance speech intelligibility in the presence of interfering talkers. Listeners were presented with a target string of spoken digits embedded in a mixture of five spatially separated speech streams. The benefit of providing simple visual cues indicating when and/or where the target would occur was measured in listeners with hearing loss, listeners with normal hearing, and a control group of listeners with normal hearing who were tested at a lower target-to-masker ratio to equate their baseline (no cue) performance with the hearing-loss group. All groups received robust benefits from the visual cues. The magnitude of the spatial-cue benefit, however, was significantly smaller in listeners with hearing loss. Results suggest that reduced utility of selective attention for resolving competition between simultaneous sounds contributes to the communication difficulties experienced by listeners with hearing loss in everyday listening situations.

Central and peripheral vision loss differentially affects contextual cueing in visual search.

PubMed

Geringswald, Franziska; Pollmann, Stefan

2015-09-01

Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental learning of contextual cues or the expression of learning, that is, the guidance of search by learned target-distractor configurations. Visual search with a central scotoma reduced contextual cueing both with respect to search times and gaze parameters. However, when the scotoma was subsequently removed, contextual cueing was observed in a comparable magnitude as for controls who had searched without scotoma simulation throughout the experiment. This indicated that search with a central scotoma did not prevent incidental context learning, but interfered with search guidance by learned contexts. We discuss the role of visuospatial working memory load as source of this interference. In contrast to central vision loss, peripheral vision loss was expected to prevent spatial configuration learning itself, because the restricted search window did not allow the integration of invariant local configurations with the global display layout. This expectation was confirmed in that visual search with a simulated peripheral scotoma eliminated contextual cueing not only in the initial learning phase with scotoma, but also in the subsequent test phase without scotoma. (c) 2015 APA, all rights reserved).

Undertreatment of Vascular Risk Factors in Patients with Monocular Ischaemic Visual Loss.

PubMed

Zarkali, Angeliki; Cheng, Suk Fun; Dados, Agnes; Simister, Robert; Chandratheva, Arvind

2018-05-17

Ischaemic visual loss is often considered a lower risk factor than other transient ischaemic attacks (TIA). We aimed to determine the recurrence risk, prevalence and management of vascular risk factors in these patients. The study took place in the University College Hospital London daily TIA clinic, main referral centre for North-Central London and Moorfields Eye Hospital. Consecutive records for patients with transient (< 24 h) or permanent (> 24 h) ischaemic visual loss were reviewed during the period January 2014-October 2016. Patients diagnosed with temporal arteritis were excluded. Of 400 patients, 224 (56%) were male with mean age 64.5 years (SD 15.1); 263 patients (65.8%) presented with transient and 137 patients (34.2%) with permanent ischaemic visual loss; 51.3% had hypertension (HTN), 35.3% hypercholesterolaemia, 14.5% diabetes, 11.8% ischaemic ocular events, 10.0% ischaemic heart disease, 7.3% atrial fibrillation (AF), 6.3% TIA, 5.3% stroke, and 12.3% were smokers. Median vascular risk factors were 2 (range 1-6), but 122 (30.5%) had ≥3. Those with diabetes (p < 0.001), HTN (p = 0.008), previous myocardial infarction (p = 0.005), or ≥3 vascular risk factors (p = 0.012) were more likely to present with permanent visual loss, while patients with history of transient events, TIA (p = 0.002), or ocular (p = 0.002) presented with transient visual loss. Ninety-day recurrence was 10.5%; this was higher in patients with ≥3 risk factors (hazard ratio 1.42, 95% CI 0.95-2.11, p = 0.111). Patients with past TIA were more likely to be on secondary prevention than those with ocular ischaemia; 60.0 vs. 34.1% received antiplatelets and 76.0 vs. 43.9% statins. At presentation, only 55.2% (16 patients) with known AF were anticoagulated, despite all of them having CHADSVASC ≥1. Approximately one-third of patients with ocular ischaemia had ≥3 vascular risk factors with recurrences higher in these patients. Yet only half of those with previous ischaemic

Central and Peripheral Vision Loss Differentially Affects Contextual Cueing in Visual Search

ERIC Educational Resources Information Center

Geringswald, Franziska; Pollmann, Stefan

2015-01-01

Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental…

Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of "Green" Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex.

PubMed

Rauscher, Franziska G; Plant, Gordon T; James-Galton, Merle; Barbur, John L

2011-01-01

Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d'Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength ("red") and middle wavelength ("green") regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient's results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both "red/green" and "yellow/blue" directions in colour space, the subject's lower left quadrant showed a marked asymmetry in "red/green" thresholds with the greatest loss of sensitivity towards the "green" region of the spectrum locus. This spatially localized asymmetric loss of "green" but not "red" sensitivity has not been reported previously in human vision. Such loss is consistent with selective damage of neural substrates in the visual cortex that process colour information, but are spectrally non-opponent.

Binocular Glaucomatous Visual Field Loss and Its Impact on Visual Exploration - A Supermarket Study

PubMed Central

Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as “passed” or “failed” with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p<0.001). Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD) area than patients who failed (t-test, p<0.05). According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a “time-effective” compensatory mechanism during the present supermarket task. PMID:25162522

Binocular glaucomatous visual field loss and its impact on visual exploration--a supermarket study.

PubMed

Sippel, Katrin; Kasneci, Enkelejda; Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as "passed" or "failed" with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p < 0.001). Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD) area than patients who failed (t-test, p < 0.05). According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a "time-effective" compensatory mechanism during the present supermarket task.

Childhood blindness: a new form for recording causes of visual loss in children.

PubMed Central

Gilbert, C.; Foster, A.; Négrel, A. D.; Thylefors, B.

1993-01-01

The new standardized form for recording the causes of visual loss in children is accompanied by coding instructions and by a database for statistical analysis. The aim is to record the causes of childhood visual loss, with an emphasis on preventable and treatable causes, so that appropriate control measures can be planned. With this standardized methodology, it will be possible to monitor the changing patterns of childhood blindness over a period of time in response to changes in health care services, specific interventions, and socioeconomic development. PMID:8261552

Fragile X syndrome: loss of local mRNA regulation alters synaptic development and function.

PubMed

Bassell, Gary J; Warren, Stephen T

2008-10-23

Fragile X syndrome is the most common inherited form of cognitive deficiency in humans and perhaps the best-understood single cause of autism. A trinucleotide repeat expansion, inactivating the X-linked FMR1 gene, leads to the absence of the fragile X mental retardation protein. FMRP is a selective RNA-binding protein that regulates the local translation of a subset of mRNAs at synapses in response to activation of Gp1 metabotropic glutamate receptors (mGluRs) and possibly other receptors. In the absence of FMRP, excess and dysregulated mRNA translation leads to altered synaptic function and loss of protein synthesis-dependent plasticity. Recent evidence indicates the role of FMRP in regulated mRNA transport in dendrites. New studies also suggest a possible local function of FMRP in axons that may be important for guidance, synaptic development, and formation of neural circuits. The understanding of FMRP function at synapses has led to rationale therapeutic approaches.

[Clinico-statistical study on availability of Esterman disability score for assessment of mobility difficulty in patients with visual field loss].

PubMed

Yamagata, Yoshitaka; Terada, Yuko; Suzuki, Atsushi; Mimura, Osamu

2010-01-01

The visual efficiency scale currently adopted to determine the legal grade of visual disability associated with visual field loss in Japan is not appropriate for the evaluation of disability regarding daily living activities. We investigated whether Esterman disability score (EDS) is suitable for the assessment of mobility difficulty in patients with visual field loss. The correlation between the EDS calculated from Goldmann's kinetic visual field and the degree of subjective mobility difficulty determined by a questionnaire was investigated in 164 patients with visual field loss. The correlation between the EDS determined using a program built into the Humphrey field analyzer and that calculated from Goldmann's kinetic visual field was also investigated. The EDS based on the kinetic visual field was correlated well with the degree of subjective mobility difficulty, and the EDS measured using the Humphrey field analyzer could be estimated from the kinetic visual field-based EDS. Instead of the currently adopted visual efficiency scale, EDS should be employed for the assessment of mobility difficulty in patients with visual field loss, also to establish new judgment criteria concerning the visual field.

Design and analysis of low-loss linear analog phase modulator for deep space spacecraft X-band transponder (DST) application

NASA Technical Reports Server (NTRS)

Mysoor, Narayan R.; Mueller, Robert O.

1991-01-01

This paper summarizes the design concepts, analyses, and the development of an X-band transponder low-loss linear phase modulator for deep space spacecraft applications. A single section breadboard circulator-coupled reflection phase modulator has been analyzed, fabricated, and evaluated. Two- and three-cascaded sections have been modeled and simulations performed to provide an X-band DST phase modulator with +/- 2.5 radians of peak phase deviation to accommodate down-link signal modulation with composite telemetry data and ranging with a deviation linearity tolerance +/- 8 percent and insertion loss of less than 10 +/- 0.5 dB. A two-section phase modulator using constant gamma hyperabrupt varactors and an efficient modulator driver circuit was breadboarded. The measured results satisfy the DST phase modulator requirements, and excellent agreement with the predicted results.

Link between orientation and retinotopic maps in primary visual cortex

PubMed Central

Paik, Se-Bum; Ringach, Dario L.

2012-01-01

Maps representing the preference of neurons for the location and orientation of a stimulus on the visual field are a hallmark of primary visual cortex. It is not yet known how these maps develop and what function they play in visual processing. One hypothesis postulates that orientation maps are initially seeded by the spatial interference of ON- and OFF-center retinal receptive field mosaics. Here we show that such a mechanism predicts a link between the layout of orientation preferences around singularities of different signs and the cardinal axes of the retinotopic map. Moreover, we confirm the predicted relationship holds in tree shrew primary visual cortex. These findings provide additional support for the notion that spatially structured input from the retina may provide a blueprint for the early development of cortical maps and receptive fields. More broadly, it raises the possibility that spatially structured input from the periphery may shape the organization of primary sensory cortex of other modalities as well. PMID:22509015

X-chromosomal inactivation directly influences the phenotypic manifestation of X-linked protoporphyria

PubMed Central

Brancaleoni, V.; Balwani, M.; Granata, F.; Graziadei, G.; Missineo, P.; Fiorentino, V.; Fustinoni, S.; Cappellini, M.D.; Naik, H.; Desnick, R.J.; Di Pierro, E.

2015-01-01

X-linked protoporphyria (XLP), a rare erythropoietic porphyria, results from terminal exon gain-of-function mutations in the ALAS2 gene causing increased ALAS2 activity and markedly increased erythrocyte protoporphyrin levels. Patients present with severe cutaneous photosensitivity and may develop liver dysfunction. XLP was originally reported as X-linked dominant with 100% penetrance in males and females. We characterized 11 heterozygous females from six unrelated XLP families and show markedly varying phenotypic and biochemical heterogeneity, reflecting the degree of X-chromsomal inactivation of the mutant gene. ALAS2 sequencing identified the specific mutation and confirmed heterozygosity among the females. Clinical history, plasma and erythrocyte protoporphyrin levels were determined. Methylation assays of the androgen receptor and zinc-finger MYM type 3 short tandem repeat polymorphisms estimated each heterozygotes X-chromosomal inactivation pattern. Heterozygotes with equal or increased skewing, favoring expression of the wild-type allele had no clinical symptoms and only slightly increased erythrocyte protoporphyrin concentrations and/or frequency of protoporphyrin-containing peripheral blood fluorocytes. When the wild-type allele was preferentially inactivated, heterozygous females manifested the disease phenotype and had both higher erythrocyte protoporphyrin levels and circulating fluorocytes. These findings confirm that the previous dominant classification of XLP is inappropriate and genetically misleading, as the disorder is more appropriately designated XLP. PMID:25615817

Linkage localization of X-linked Charcot-Marie-Tooth disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergoffen, J.; Trofatter, J.; Haines, J.L.

1993-02-01

Charcot-Marie-Tooth disease (CMT), also known as hereditary motor and sensory neuropathy, is a heterogeneous group of slowly progressive, degenerative disorders of peripheral nerve. X-linked CMT (CMTX) (McKusick 302800), a subdivision of type I, or demyelinating, CMT is an X-linked dominant condition with variable penetrance. Previous linkage analysis using RFLPs demonstrated linkage to markers on the proximal long and short arms of the X chromosome, with the more likely localization on the proximal long arm of the X chromosome. Available variable simple-sequence repeats (VSSRs) broaden the possibilities for linkage analysis. This paper presents new linkage data and recombination analysis derived frommore » work with four VSSR markers - AR, PGKP1, DXS453, and DXYS1X - in addition to analysis using RFLP markers described elsewhere. These studies localize the CMTX gene to the proximal Xq segment between PGKP1 (Xq11.2-12) and DXS72 (Xq21.1), with a combined maximum multipoint lod score of 15.3 at DXS453 ([theta] = 0). 32 refs., 3 figs., 2 tabs.« less

X-inactivation patterns in female Leber`s hereditary optic neuropathy patients do not support a strong X-linked determinant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pegoraro, E.; Hoffman, E.P.; Carelli, V.

1996-02-02

Leber`s hereditary optic neuropathy (LHON) accounts for about 3% of the cases of blindness in young adult males. The underlying mitochondrial pathogenesis of LHON has been well studied, with specific mitochondrial DNA (mtDNA) mutations of structural genes described and well characterized. However, enigmatic aspects of the disease are not explained by mutation data, such as the higher proportion of affected males, the later onset of the disease in females, and the presence of unaffected individuals with a high proportion of mutant mtDNA. A hypothesis which has been put forward to explain the unusual disease expression is a dual model ofmore » mtDNA and X-linked nuclear gene inheritance. If a nuclear X-linked modifier gene influences the expression of the mitochondrial-linked mutant gene then the affected females should be either homozygous for the nuclear determinant, or if heterozygous, lyonization should favor the mutant X. In order to determine if an X-linked gene predisposes to LHON phenotype we studied X-inactivation patterns in 35 females with known mtDNA mutations from 10 LHON pedigrees. Our results do not support a strong X-linked determinant in LHON cause: 2 of the 10 (20%) manifesting carriers showed skewing of X-inactivation, as did 3 of the 25 (12%) nonmanifesting carriers. 39 refs., 2 figs., 1 tab.« less

Childhood blindness and visual loss: an assessment at two institutions including a "new" cause.

PubMed Central

Mets, M B

1999-01-01

PURPOSE: This study was initiated to investigate the causes of childhood blindness and visual impairment in the United States. We also sought a particular etiology--congenital lymphocytic choriomeningitis virus (LCMV)--which has been considered exceedingly rare, in a fixed target population of children, the severely mentally retarded. METHODS: We undertook a library-based study of the world literature to shed light on the causes of childhood blindness internationally and to put our data in context. We prospectively examined all consented children (159) at 2 institutions in the United States to determine their ocular status and the etiology of any visual loss present. One of the institutions is a school for the visually impaired (hereafter referred to as Location V), in which most of the students have normal mentation. The other is a home for severely mentally retarded, nonambulatory children (hereafter referred to as Location M). This institution was selected specifically to provide a sample of visual loss associated with severe retardation because the handful of cases of LCMV in the literature have been associated with severe central nervous system insults. Histories were obtained from records on site, and all children received a complete cyclopleged ophthalmic examination at their institution performed by the author. Patients at Location M with chorioretinal scars consistent with intrauterine infection (a possible sign of LCMV) had separate consents for blood drawing. Sera was obtained and sent for standard TORCHS titers, toxoplasmosis titers (Jack S. Remington, MD, Palo Alto, Calif), and ELISA testing for LCMV (Centers for Disease Control and Prevention, Atlanta, Ga). RESULTS: The diagnoses at Location V were varied and included retinopathy of prematurity (19.4%), optic atrophy (19.4%), retinitis pigmentosa (14.5%), optic nerve hypoplasia (12.9%), cataracts (8.1%), foveal hypoplasia (8.1%), persistent hyperplastic primary vitreous (4.8%), and microphthalmos (3

Genome-wide misexpression of X-linked versus autosomal genes associated with hybrid male sterility.

PubMed

Lu, Xuemei; Shapiro, Joshua A; Ting, Chau-Ti; Li, Yan; Li, Chunyan; Xu, Jin; Huang, Huanwei; Cheng, Ya-Jen; Greenberg, Anthony J; Li, Shou-Hsien; Wu, Mao-Lien; Shen, Yang; Wu, Chung-I

2010-08-01

Postmating reproductive isolation is often manifested as hybrid male sterility, for which X-linked genes are overrepresented (the so-called large X effect). In contrast, X-linked genes are significantly under-represented among testis-expressing genes. This seeming contradiction may be germane to the X:autosome imbalance hypothesis on hybrid sterility, in which the X-linked effect is mediated mainly through the misexpression of autosomal genes. In this study, we compared gene expression in fertile and sterile males in the hybrids between two Drosophila species. These hybrid males differ only in a small region of the X chromosome containing the Ods-site homeobox (OdsH) (also known as Odysseus) locus of hybrid sterility. Of genes expressed in the testis, autosomal genes were, indeed, more likely to be misexpressed than X-linked genes under the sterilizing action of OdsH. Since this mechanism of X:autosome interaction is only associated with spermatogenesis, a connection between X:autosome imbalance and the high rate of hybrid male sterility seems plausible.

Auditory preferences of young children with and without hearing loss for meaningful auditory-visual compound stimuli.

PubMed

Zupan, Barbra; Sussman, Joan E

2009-01-01

Experiment 1 examined modality preferences in children and adults with normal hearing to combined auditory-visual stimuli. Experiment 2 compared modality preferences in children using cochlear implants participating in an auditory emphasized therapy approach to the children with normal hearing from Experiment 1. A second objective in both experiments was to evaluate the role of familiarity in these preferences. Participants were exposed to randomized blocks of photographs and sounds of ten familiar and ten unfamiliar animals in auditory-only, visual-only and auditory-visual trials. Results indicated an overall auditory preference in children, regardless of hearing status, and a visual preference in adults. Familiarity only affected modality preferences in adults who showed a strong visual preference to unfamiliar stimuli only. The similar degree of auditory responses in children with hearing loss to those from children with normal hearing is an original finding and lends support to an auditory emphasis for habilitation. Readers will be able to (1) Describe the pattern of modality preferences reported in young children without hearing loss; (2) Recognize that differences in communication mode may affect modality preferences in young children with hearing loss; and (3) Understand the role of familiarity in modality preferences in children with and without hearing loss.

Science & Art in Motion: Visualizing the X-ray Universe

NASA Astrophysics Data System (ADS)

Hobart, A. J.; Arcand, K. K.; Edmonds, P. D.; Tucker, W. H.

2005-12-01

Since its launch in 1999, the Chandra X-ray Observatory has probed regions around black holes, traced the debris of exploded stars, and helped to elucidate the formation of galaxy clusters, the largest bound structures in the Universe. Conveying Chandra's exciting, though often complicated, high-energy results to the public and the media poses certain visual challenges, such as photon-starved observational data, spectra, and esoteric concepts. This poster will demonstrate some of the techniques developed to present visuals by way of motion graphics in X-ray astronomy. Some tricks of the trade will be highlighted, including establishing texture libraries, using particle or paint effects, and modeling stock objects. Topics unique to animating scientific concepts for public consumption will also be discussed, such as addressing public perception versus scientists' findings, keeping a high standard of accuracy while leaving room for visual excitement, communicating with scientists for revisions, and creative ways to interact with and educate the public. Developed with funding from NASA under Contract NAS8-39073.

Un-explained visual loss following silicone oil removal: results of the Pan American Collaborative Retina Study (PACORES) Group.

PubMed

Roca, Jose A; Wu, Lihteh; Berrocal, Maria; Rodriguez, Francisco; Alezzandrini, Arturo; Alvira, Gustavo; Velez-Montoya, Raul; Quiroz-Mercado, Hugo; Fernando Arevalo, J; Serrano, Martín; Lima, Luiz H; Figueroa, Marta; Farah, Michel; Chico, Giovanna

2017-01-01

To report the incidence and clinical features of patients that experienced un-explained visual loss following silicone oil (SO) removal. Multicenter retrospective study of patients that underwent SO removal during 2000-2012. Visual loss of ≥2 lines was considered significant. A total of 324 eyes of 324 patients underwent SO removal during the study period. Forty two (13%) eyes suffered a significant visual loss following SO removal. Twenty three (7.1%) of these eyes lost vision secondary to known causes. In the remaining 19 (5.9%) eyes, the loss of vision was not explained by any other pathology. Eleven of these 19 patients (57.9%) were male. The mean age of this group was 49.2 ± 16.4 years. Eyes that had an un-explained visual loss had a mean IOP while the eye was filled with SO of 19.6 ± 6.9 mm Hg. The length of time that the eye was filled with SO was 14.8 ± 4.4 months. In comparison, eyes that did not experience visual loss had a mean IOP of 14 ± 7.3 mm Hg ( p  < 0.0002) and a mean tamponade duration of 9.3 ± 10.9 months ( p  < 0.0001). An un-explained visual loss after SO removal was observed in 5.9% of eyes. Factors associated with this phenomenon included a higher IOP and longer SO tamponade duration.

Transmitter pointing loss calculation for free-space optical communications link analyses

NASA Technical Reports Server (NTRS)

Marshall, William K.

1987-01-01

In calculating the performance of free-space optical communications links, the transmitter pointing loss is one of the two most important factors. It is shown in this paper that the traditional formula for the instantaneous pointing loss (i.e., for the transmitter telescope far-field beam pattern) is quite inaccurate. A more accurate and practical approximation is developed in which the pointing loss is calculated using a Taylor series approximation. The four-term series is shown to be accurate to 0.1 dB for the theta angles not greater than 0.9 lambda/D (wavelength/telescope diameter).

Emotion Recognition and Visual-Scan Paths in Fragile X Syndrome

ERIC Educational Resources Information Center

Shaw, Tracey A.; Porter, Melanie A.

2013-01-01

This study investigated emotion recognition abilities and visual scanning of emotional faces in 16 Fragile X syndrome (FXS) individuals compared to 16 chronological-age and 16 mental-age matched controls. The relationships between emotion recognition, visual scan-paths and symptoms of social anxiety, schizotypy and autism were also explored.…

Genome-wide misexpression of X-linked versus autosomal genes associated with hybrid male sterility

PubMed Central

Lu, Xuemei; Shapiro, Joshua A.; Ting, Chau-Ti; Li, Yan; Li, Chunyan; Xu, Jin; Huang, Huanwei; Cheng, Ya-Jen; Greenberg, Anthony J.; Li, Shou-Hsien; Wu, Mao-Lien; Shen, Yang; Wu, Chung-I

2010-01-01

Postmating reproductive isolation is often manifested as hybrid male sterility, for which X-linked genes are overrepresented (the so-called large X effect). In contrast, X-linked genes are significantly under-represented among testis-expressing genes. This seeming contradiction may be germane to the X:autosome imbalance hypothesis on hybrid sterility, in which the X-linked effect is mediated mainly through the misexpression of autosomal genes. In this study, we compared gene expression in fertile and sterile males in the hybrids between two Drosophila species. These hybrid males differ only in a small region of the X chromosome containing the Ods-site homeobox (OdsH) (also known as Odysseus) locus of hybrid sterility. Of genes expressed in the testis, autosomal genes were, indeed, more likely to be misexpressed than X-linked genes under the sterilizing action of OdsH. Since this mechanism of X:autosome interaction is only associated with spermatogenesis, a connection between X:autosome imbalance and the high rate of hybrid male sterility seems plausible. PMID:20511493

Genetics Home Reference: X-linked cardiac valvular dysplasia

MedlinePlus

... inflammation of the inner lining of the heart (endocarditis), abnormal blood clots, or sudden death. X-linked ... Johns Hopkins Medicine: Mitral Valve Prolapse MedlinePlus Encyclopedia: Endocarditis MedlinePlus Encyclopedia: Mitral Valve Prolapse General Information from ...

Abnormal late visual responses and alpha oscillations in neurofibromatosis type 1: a link to visual and attention deficits

PubMed Central

2014-01-01

Background Neurofibromatosis type 1 (NF1) affects several areas of cognitive function including visual processing and attention. We investigated the neural mechanisms underlying the visual deficits of children and adolescents with NF1 by studying visual evoked potentials (VEPs) and brain oscillations during visual stimulation and rest periods. Methods Electroencephalogram/event-related potential (EEG/ERP) responses were measured during visual processing (NF1 n = 17; controls n = 19) and idle periods with eyes closed and eyes open (NF1 n = 12; controls n = 14). Visual stimulation was chosen to bias activation of the three detection mechanisms: achromatic, red-green and blue-yellow. Results We found significant differences between the groups for late chromatic VEPs and a specific enhancement in the amplitude of the parieto-occipital alpha amplitude both during visual stimulation and idle periods. Alpha modulation and the negative influence of alpha oscillations in visual performance were found in both groups. Conclusions Our findings suggest abnormal later stages of visual processing and enhanced amplitude of alpha oscillations supporting the existence of deficits in basic sensory processing in NF1. Given the link between alpha oscillations, visual perception and attention, these results indicate a neural mechanism that might underlie the visual sensitivity deficits and increased lapses of attention observed in individuals with NF1. PMID:24559228

Linking assumptions in amblyopia

PubMed Central

LEVI, DENNIS M.

2017-01-01

Over the last 35 years or so, there has been substantial progress in revealing and characterizing the many interesting and sometimes mysterious sensory abnormalities that accompany amblyopia. A goal of many of the studies has been to try to make the link between the sensory losses and the underlying neural losses, resulting in several hypotheses about the site, nature, and cause of amblyopia. This article reviews some of these hypotheses, and the assumptions that link the sensory losses to specific physiological alterations in the brain. Despite intensive study, it turns out to be quite difficult to make a simple linking hypothesis, at least at the level of single neurons, and the locus of the sensory loss remains elusive. It is now clear that the simplest notion—that reduced contrast sensitivity of neurons in cortical area V1 explains the reduction in contrast sensitivity—is too simplistic. Considerations of noise, noise correlations, pooling, and the weighting of information also play a critically important role in making perceptual decisions, and our current models of amblyopia do not adequately take these into account. Indeed, although the reduction of contrast sensitivity is generally considered to reflect “early” neural changes, it seems plausible that it reflects changes at many stages of visual processing. PMID:23879956

Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of “Green” Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex

PubMed Central

Rauscher, Franziska G.; Plant, Gordon T.; James-Galton, Merle; Barbur, John L.

2011-01-01

Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d’Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength (“red”) and middle wavelength (“green”) regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient’s results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both “red/green” and “yellow/blue” directions in colour space, the subject’s lower left quadrant showed a marked asymmetry in “red/green” thresholds with the greatest loss of sensitivity towards the “green” region of the spectrum locus. This spatially localized asymmetric loss of “green” but not “red” sensitivity has not been reported previously in human vision. Such loss is consistent with selective damage of neural substrates in the visual cortex that process colour information, but are spectrally non-opponent. PMID:27956924

Visual estimation versus gravimetric measurement of postpartum blood loss: a prospective cohort study.

PubMed

Al Kadri, Hanan M F; Al Anazi, Bedayah K; Tamim, Hani M

2011-06-01

One of the major problems in international literature is how to measure postpartum blood loss with accuracy. We aimed in this research to assess the accuracy of visual estimation of postpartum blood loss (by each of two main health-care providers) compared with the gravimetric calculation method. We carried out a prospective cohort study at King Abdulaziz Medical City, Riyadh, Saudi Arabia between 1 November 2009 and 31 December 2009. All women who were admitted to labor and delivery suite and delivered vaginally were included in the study. Postpartum blood loss was visually estimated by the attending physician and obstetrics nurse and then objectively calculated by a gravimetric machine. Comparison between the three methods of blood loss calculation was carried out. A total of 150 patients were included in this study. There was a significant difference between the gravimetric calculated blood loss and both health-care providers' estimation with a tendency to underestimate the loss by about 30%. The background and seniority of the assessing health-care provider did not affect the accuracy of the estimation. The corrected incidence of postpartum hemorrhage in Saudi Arabia was found to be 1.47%. Health-care providers tend to underestimate the volume of postpartum blood loss by about 30%. Training and continuous auditing of the diagnosis of postpartum hemorrhage is needed to avoid missing cases and thus preventing associated morbidity and mortality.

Dual Sensory Loss: Overview of Problems, Visual Assessment, and Rehabilitation

PubMed Central

Brabyn, John A.; Schneck, Marilyn E.; Haegerstrom-Portnoy, Gunilla; Lott, Lori A.

2007-01-01

This article provides an overview of some of the problems and possible solutions surrounding the neglected issue of combined vision and hearing deficits. The subject is treated by considering each subpopulation, ranging from those who have no residual vision or hearing to those with mild coexisting vision and hearing losses. An attempt is made to relate the different types of visual deficit to the likely problems encountered in real-life activities, such as communication and travel, among individuals who also have a hearing impairment. The assessment and appropriate referral of patients with these combined deficits is discussed, including the interpretation of visual test results and the importance of factors other than standard visual acuity. Speculation is offered on potential strategies and solutions for rehabilitation as well as the need for future research and improvements in service delivery. PMID:18003865

Patterns of non-embolic transient monocular visual field loss.

PubMed

Petzold, Axel; Islam, Niaz; Plant, G T

2013-07-01

The aim of this study was to systematically describe the semiology of non-embolic transient monocular visual field loss (neTMVL). We conducted a retrospective case note analysis of patients from Moorfields Eye Hospital (1995-2007). The variables analysed were age, age of onset, gender, past medical history or family history of migraine, eye affected, onset, duration and offset, perception (pattern, positive and negative symptoms), associated headache and autonomic symptoms, attack frequency, and treatment response to nifedipine. We identified 77 patients (28 male and 49 female). Mean age of onset was 37 years (range 14-77 years). The neTMVL was limited to the right eye in 36 % to the left in 47 % and occurred independently in either eye in 5 % of cases. A past medical history of migraine was present in 12 % and a family history in 8 %. Headache followed neTMVL in 14 % and was associated with autonomic features in 3 %. The neTMB was perceived as grey in 35 %, white in 21 %, black in 16 % and as phosphenes in 9 %. Most frequently neTMVL was patchy 20 %. Recovery of vision frequently resembled attack onset in reverse. In 3 patients without associated headache the loss of vision was permanent. Treatment with nifedipine was initiated in 13 patients with an attack frequency of more than one per week and reduced the attack frequency in all. In conclusion, this large series of patients with neTMVL permits classification into five types of reversible visual field loss (grey, white, black, phosphenes, patchy). Treatment response to nifidipine suggests some attacks to be caused by vasospasm.

SOURCES OF BINOCULAR SUPRATHRESHOLD VISUAL FIELD LOSS IN A COHORT OF OLDER WOMEN BEING FOLLOWED FOR RISK OF FALLS (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

PubMed Central

Coleman, Anne Louise

2007-01-01

Purpose To determine the sources of binocular visual field loss most strongly associated with falls in a cohort of older women. Methods In the Study of Osteoporotic Fractures, women with severe binocular visual field loss had an increased risk of two or more falls during the 12 months following the eye examination. The lens and fundus photographs of the 422 women with severe binocular visual field loss, plus a random sample of 141 white women with no, mild, or moderate binocular visual field loss—47 white women with no binocular visual field loss, 46 white women with mild binocular visual field loss, and 48 white women with moderate binocular visual field loss —were evaluated for lens opacities, glaucomatous optic nerve damage, age-related macular degeneration, and diabetic retinopathy. Results Eighty-four percent of the women with severe binocular visual field loss had ocular disease in one or both eyes. Bilateral cataracts and glaucomatous optic nerve damage were the most common sources of this severe binocular visual field loss. Approximately 15.2% of women had no evidence of lens opacities, glaucomatous optic nerve damage, age-related macular degeneration, or diabetic retinopathy. Conclusion Severe binocular visual field loss due primarily to cataracts, glaucoma, and age-related macular degeneration explains 33.3% of the falls among women who fell frequently. Because binocular visual field loss may be treatable and/or preventable, screening programs for binocular visual field loss and subsequent referral for intervention and treatment are recommended as a strategy for preventing falls among the elderly. PMID:18427619

X-linked mental retardation associated with macro-orchidism.

PubMed Central

Turner, G; Eastman, C; Casey, J; McLeay, A; Procopis, P; Turner, B

1975-01-01

Two families are described with an X-linked form of mental retardation in whom the affected males were found to have bilateral enlargement of the testes. No conclusive evidence of any endocrinological disturbance was found. Images PMID:1240971

Medically unexplained visual loss in a specialist clinic: a retrospective case-control comparison.

PubMed

O'Leary, Éanna D; McNeillis, Benjamin; Aybek, Selma; Riordan-Eva, Paul; David, Anthony S

2016-02-15

To compare the clinical and demographic characteristics of adult patients with nonorganic or medically unexplained visual loss (MUVL) to those with other common conditions presenting to a neuro-ophthalmology clinic. Case-control design: a retrospective review of medical notes on a consecutive case series of 49 patients assessed at the King's College Hospital neuro-ophthalmology clinic with unexplained visual loss and matched with the next assessed patient identified from clinic records. Patients presented post-symptom onset with a mean clinical course of 30 months (SD=67 months) and standard clinical examination used to confirm diagnoses, alongside ancillary investigations if required. Seventy-two percent (n=36) of MUVL patients were female. In comparison with patients with organic visual disorders, MUVL cases presented with significantly higher rates of bilateral (cf. unilateral) visual impairment (41%, n=20), premorbid psychiatric (27%, n=13) as well as functional (24%, n=12) diagnoses and psychotropic medication usage (22%, n=11). Medically unexplained cases were significantly more likely to report preceding psychological stress (n=9; 18%). Medically unexplained visual impairment may be regarded as part of the spectrum of medically unexplained disorders seen in the general hospital setting. Research is needed to determine long-term outcomes and effective tailored interventions. Copyright © 2016 Elsevier B.V. All rights reserved.

Editorial: X-chromosome-linked Kallmann's syndrome: Pathology at the molecular level

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prager, D.; Braunstein, G.D.

Kallmann's syndrome or olfactogenital dysplasia refers to a disorder characterized by hypogonadotropic hypogonadism and anosmia or hyposmia which can occur sporadically or in a familial setting. Originally described in 1856, the first familial cases were reported by Kallmann et al., in 1944. Based on segregation analysis of multiple families, three modes of transmission have been documented: X-linked, autosomal dominant with variable penetrance, and autosomal recessive. Kallmann's syndrome occurs in less than 1 in 10,000 male births, with a 5-fold excess of affected males to females, suggesting that the X-linked form is the most frequent. By genetic linkage analysis the X-linkedmore » form of Kallmann's syndrome was localized to Xp22.3. This was confirmed by the description of patients with contiguous gene syndromes due to deletions of various portions of the distal short arm of the X-chromosome. Such patients present with complex phenotypes characterized by a combination of Kallmann's syndrome with X-linked icthyosis due to steroid sulfatase deficiency, chondrodysplasia punctata, short stature, and mental retardation. DNA analysis has identified and mapped the genes responsible for these disorders. 10 refs., 1 fig., 1 tab.« less

Identifying Return-Current Losses in Flare Hard X-ray Spectra

NASA Technical Reports Server (NTRS)

Holman, Gordon D.

2011-01-01

I will report on theoretical studies and a data analysis program aimed at identifying and physically interpreting breaks in hard X-ray spectra resulting from return-current energy losses, as well as heating of the flare plasma resulting from these losses.

A previously unreported, dominantly inherited syndrome of shortness of stature, ear malformations, and hip dislocation: the coxoauricular syndrome--autosomal or X-linked male-lethal.

PubMed

Duca, D; Pană, I; Ciovirnache, M; Simionesu, L; Ispas, I; Maxililian, C

1981-01-01

We reported an apparently previously undescribed syndrome, designated the coxoauricular syndrome, in a mother and her 3 daughters, all of whom shared in variable manner shortness of stature, minor vertebral and pelvic changes, dislocated hip(s), and microtia with corresponding hearing loss. The oldest daughter had coincidental Ullrich-Turner syndrome with 46, Xdel(X)(q 13) chromosome constitution. Inheritance of the trait in this family is dominant, either autosomal or X-linked, with hemizygote lethality.

Retinal Structures and Visual Cortex Activity are Impaired Prior to Clinical Vision Loss in Glaucoma.

PubMed

Murphy, Matthew C; Conner, Ian P; Teng, Cindy Y; Lawrence, Jesse D; Safiullah, Zaid; Wang, Bo; Bilonick, Richard A; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S; Chan, Kevin C

2016-08-11

Glaucoma is the second leading cause of blindness worldwide and its pathogenesis remains unclear. In this study, we measured the structure, metabolism and function of the visual system by optical coherence tomography and multi-modal magnetic resonance imaging in healthy subjects and glaucoma patients with different degrees of vision loss. We found that inner retinal layer thinning, optic nerve cupping and reduced visual cortex activity occurred before patients showed visual field impairment. The primary visual cortex also exhibited more severe functional deficits than higher-order visual brain areas in glaucoma. Within the visual cortex, choline metabolism was perturbed along with increasing disease severity in the eye, optic radiation and visual field. In summary, this study showed evidence that glaucoma deterioration is already present in the eye and the brain before substantial vision loss can be detected clinically using current testing methods. In addition, cortical cholinergic abnormalities are involved during trans-neuronal degeneration and can be detected non-invasively in glaucoma. The current results can be of impact for identifying early glaucoma mechanisms, detecting and monitoring pathophysiological events and eye-brain-behavior relationships, and guiding vision preservation strategies in the visual system, which may help reduce the burden of this irreversible but preventable neurodegenerative disease.

Retinal Structures and Visual Cortex Activity are Impaired Prior to Clinical Vision Loss in Glaucoma

PubMed Central

Murphy, Matthew C.; Conner, Ian P.; Teng, Cindy Y.; Lawrence, Jesse D.; Safiullah, Zaid; Wang, Bo; Bilonick, Richard A.; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S.; Chan, Kevin C.

2016-01-01

Glaucoma is the second leading cause of blindness worldwide and its pathogenesis remains unclear. In this study, we measured the structure, metabolism and function of the visual system by optical coherence tomography and multi-modal magnetic resonance imaging in healthy subjects and glaucoma patients with different degrees of vision loss. We found that inner retinal layer thinning, optic nerve cupping and reduced visual cortex activity occurred before patients showed visual field impairment. The primary visual cortex also exhibited more severe functional deficits than higher-order visual brain areas in glaucoma. Within the visual cortex, choline metabolism was perturbed along with increasing disease severity in the eye, optic radiation and visual field. In summary, this study showed evidence that glaucoma deterioration is already present in the eye and the brain before substantial vision loss can be detected clinically using current testing methods. In addition, cortical cholinergic abnormalities are involved during trans-neuronal degeneration and can be detected non-invasively in glaucoma. The current results can be of impact for identifying early glaucoma mechanisms, detecting and monitoring pathophysiological events and eye-brain-behavior relationships, and guiding vision preservation strategies in the visual system, which may help reduce the burden of this irreversible but preventable neurodegenerative disease. PMID:27510406

Vascular and connective tissue anomalies associated with X-linked periventricular heterotopia due to mutations in Filamin A

PubMed Central

Reinstein, Eyal; Frentz, Sophia; Morgan, Tim; García-Miñaúr, Sixto; Leventer, Richard J; McGillivray, George; Pariani, Mitchel; van der Steen, Anthony; Pope, Michael; Holder-Espinasse, Muriel; Scott, Richard; Thompson, Elizabeth M; Robertson, Terry; Coppin, Brian; Siegel, Robert; Bret Zurita, Montserrat; Rodríguez, Jose I; Morales, Carmen; Rodrigues, Yuri; Arcas, Joaquín; Saggar, Anand; Horton, Margaret; Zackai, Elaine; Graham, John M; Rimoin, David L; Robertson, Stephen P

2013-01-01

Mutations conferring loss of function at the FLNA (encoding filamin A) locus lead to X-linked periventricular nodular heterotopia (XL-PH), with seizures constituting the most common clinical manifestation of this disorder in female heterozygotes. Vascular dilatation (mainly the aorta), joint hypermobility and variable skin findings are also associated anomalies, with some reports suggesting that this might represents a separate syndrome allelic to XL-PH, termed as Ehlers-Danlos syndrome-periventricular heterotopia variant (EDS-PH). Here, we report a cohort of 11 males and females with both hypomorphic and null mutations in FLNA that manifest a wide spectrum of connective tissue and vascular anomalies. The spectrum of cutaneous defects was broader than previously described and is inconsistent with a specific type of EDS. We also extend the range of vascular anomalies associated with XL-PH to included peripheral arterial dilatation and atresia. Based on these observations, we suggest that there is little molecular or clinical justification for considering EDS-PH as a separate entity from XL-PH, but instead propose that there is a spectrum of vascular and connective tissues anomalies associated with this condition for which all individuals with loss-of-function mutations in FLNA should be evaluated. In addition, since some patients with XL-PH can present primarily with a joint hypermobility syndrome, we propose that screening for cardiovascular manifestations should be offered to those patients when there are associated seizures or an X-linked pattern of inheritance. PMID:23032111

The multifocal electroretinogram in X-linked juvenile retinoschisis.

PubMed

Huang, Shizhou; Wu, Dezheng; Jiang, Futian; Luo, Guangwei; Liang, Jiongji; Wen, Feng; Yu, Minzhong; Long, Shixian; Wu, Lezheng

2003-05-01

To measure and compare the multifocal electroretinography in normal control and X-linked juvenile retinoschisis, 13 cases (13 right eyes) of normal control and nine cases (17 eyes) of X-linked juvenile retinoschisis were measured with VERIS Science 4.0. Four cases (eight eyes) out of the nine retinoschisis cases were tested with Ganzfeld ERG at the same day. The results showed statistically significant difference of average response densities and latencies in six ring retinal regions between the normal control and retinoschisis. The trace array and 3-D topography of multifocal ERG showed multi-area amplitude decrease with absence or reduction of central peak amplitude in patients with retinoschisis. The P1/N1 ratio of multifocal ERG average response densities in six ring retinal regions was different from the b/a ratio of Ganzfeld ERG. The multifocal ERG and Ganzfeld ERG each had its advantage in the diagnosis of retinoschisis.

X-Linked Retinoschisis: Phenotypic Variability in a Chinese Family

PubMed Central

Xiao, Yangyan; Liu, Xiao; Tang, Luosheng; Wang, Xia; Coursy, Terry; Guo, Xiaojian; Li, Zhuo

2016-01-01

X-linked juvenile retinoschisis (XLRS), a leading cause of juvenile macular degeneration, is characterized by a spoke-wheel pattern in the macular region of the retina and splitting of the neurosensory retina. Our study is to describe the clinical characteristics of a four generations of this family (a total of 18 members)with X-linked retinoschisis (XLRS) and detected a novel mutations of c.3G > A (p.M1?) in the initiation codon of the RS1 gene. by direct sequencing.Identification of this mutation in this family provides evidence about potential genetic or environmental factors on its phenotypic variance, as patients presented with different phenotypes regardless of having the same mutation. Importantly, OCT has proven vital for XLRS diagnosis in children. PMID:26823236

X-Linked Retinoschisis: Phenotypic Variability in a Chinese Family.

PubMed

Xiao, Yangyan; Liu, Xiao; Tang, Luosheng; Wang, Xia; Coursey, Terry G; Coursy, Terry; Guo, Xiaojian; Li, Zhuo

2016-01-29

X-linked juvenile retinoschisis (XLRS), a leading cause of juvenile macular degeneration, is characterized by a spoke-wheel pattern in the macular region of the retina and splitting of the neurosensory retina. Our study is to describe the clinical characteristics of a four generations of this family (a total of 18 members)with X-linked retinoschisis (XLRS) and detected a novel mutations of c.3G > A (p.M1?) in the initiation codon of the RS1 gene. by direct sequencing.Identification of this mutation in this family provides evidence about potential genetic or environmental factors on its phenotypic variance, as patients presented with different phenotypes regardless of having the same mutation. Importantly, OCT has proven vital for XLRS diagnosis in children.

X-linked adrenoleukodystrophy in heterozygous female patients: women are not just carriers.

PubMed

Lourenço, Charles Marques; Simão, Gustavo Novelino; Santos, Antonio Carlos; Marques, Wilson

2012-07-01

X-linked adrenoleukodystrophy (X-ALD) is a recessive X-linked disorder associated with marked phenotypic variability. Female carriers are commonly thought to be normal or only mildly affected, but their disease still needs to be better described and systematized. To review and systematize the clinical features of heterozygous women followed in a Neurogenetics Clinic. We reviewed the clinical, biochemical, and neuroradiological data of all women known to have X-ADL. The nine women identified were classified into three groups: with severe and aggressive diseases; with slowly progressive, spastic paraplegia; and with mildly decreased vibratory sensation, brisk reflexes, and no complaints. Many of these women did not have a known family history of X-ALD. Heterozygous women with X-ADL have a wide spectrum of clinical manifestations, ranging from mild to severe phenotypes.

The Glenn A. Fry Award Lecture 2012: Plasticity of the visual system following central vision loss.

PubMed

Chung, Susana T L

2013-06-01

Following the onset of central vision loss, most patients develop an eccentric retinal location outside the affected macular region, the preferred retinal locus (PRL), as their new reference for visual tasks. The first goal of this article is to present behavioral evidence showing the presence of experience-dependent plasticity in people with central vision loss. The evidence includes the presence of oculomotor re-referencing of fixational saccades to the PRL; the characteristics of the shape of the crowding zone (spatial region within which the presence of other objects affects the recognition of a target) at the PRL are more "foveal-like" instead of resembling those of the normal periphery; and the change in the shape of the crowding zone at a para-PRL location that includes a component referenced to the PRL. These findings suggest that there is a shift in the referencing locus of the oculomotor and the sensory visual system from the fovea to the PRL for people with central vision loss, implying that the visual system for these individuals is still plastic and can be modified through experiences. The second goal of the article is to demonstrate the feasibility of applying perceptual learning, which capitalizes on the presence of plasticity, as a tool to improve functional vision for people with central vision loss. Our finding that visual function could improve with perceptual learning presents an exciting possibility for the development of an alternative rehabilitative strategy for people with central vision loss.

X-Linked Glomerulopathy Due to COL4A5 Founder Variant.

PubMed

Barua, Moumita; John, Rohan; Stella, Lorenzo; Li, Weili; Roslin, Nicole M; Sharif, Bedra; Hack, Saidah; Lajoie-Starkell, Ginette; Schwaderer, Andrew L; Becknell, Brian; Wuttke, Matthias; Köttgen, Anna; Cattran, Daniel; Paterson, Andrew D; Pei, York

2018-03-01

Alport syndrome is a rare hereditary disorder caused by rare variants in 1 of 3 genes encoding for type IV collagen. Rare variants in COL4A5 on chromosome Xq22 cause X-linked Alport syndrome, which accounts for ∼80% of the cases. Alport syndrome has a variable clinical presentation, including progressive kidney failure, hearing loss, and ocular defects. Exome sequencing performed in 2 affected related males with an undefined X-linked glomerulopathy characterized by global and segmental glomerulosclerosis, mesangial hypercellularity, and vague basement membrane immune complex deposition revealed a COL4A5 sequence variant, a substitution of a thymine by a guanine at nucleotide 665 (c.T665G; rs281874761) of the coding DNA predicted to lead to a cysteine to phenylalanine substitution at amino acid 222, which was not seen in databases cataloguing natural human genetic variation, including dbSNP138, 1000 Genomes Project release version 01-11-2004, Exome Sequencing Project 21-06-2014, or ExAC 01-11-2014. Review of the literature identified 2 additional families with the same COL4A5 variant leading to similar atypical histopathologic features, suggesting a unique pathologic mechanism initiated by this specific rare variant. Homology modeling suggests that the substitution alters the structural and dynamic properties of the type IV collagen trimer. Genetic analysis comparing members of the 3 families indicated a distant relationship with a shared haplotype, implying a founder effect. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss

PubMed Central

Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

2015-01-01

The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research. PMID:25972788

Bilateral Symmetry of Visual Function Loss in Cone-Rod Dystrophies.

PubMed

Galli-Resta, Lucia; Falsini, Benedetto; Rossi, Giuseppe; Piccardi, Marco; Ziccardi, Lucia; Fadda, Antonello; Minnella, Angelo; Marangoni, Dario; Placidi, Giorgio; Campagna, Francesca; Abed, Edoardo; Bertelli, Matteo; Zuntini, Monia; Resta, Giovanni

2016-07-01

To investigate bilateral symmetry of visual impairment in cone-rod dystrophy (CRD) patients and understand the feasibility of clinical trial designs treating one eye and using the untreated eye as an internal control. This was a retrospective study of visual function loss measures in 436 CRD patients followed at the Ophthalmology Department of the Catholic University in Rome. Clinical measures considered were best-corrected visual acuity, focal macular cone electroretinogram (fERG), and Ganzfeld cone-mediated and rod-mediated electroretinograms. Interocular agreement in each of these clinical indexes was assessed by t- and Wilcoxon tests for paired samples, structural (Deming) regression analysis, and intraclass correlation. Baseline and follow-up measures were analyzed. A separate analysis was performed on the subset of 61 CRD patients carrying likely disease-causing mutations in the ABCA4 gene. Statistical tests show a very high degree of bilateral symmetry in the extent and progression of visual impairment in the fellow eyes of CRD patients. These data contribute to a better understanding of CRDs and support the feasibility of clinical trial designs involving unilateral eye treatment with the use of fellow eye as internal control.

Neovascular glaucoma in a patient with X-linked juvenile retinoschisis.

PubMed

Zuo, Chengguo; Chen, Changzheng; Xing, Yiqiao; Du, Lei

2005-09-01

To report the rubeosis iridis and neovascular glaucoma findings in one patient of X-linked juvenile retinoschisis(XLRS). Color fundus photography, fluorescein angiography (FFA), OCT and B-scan were performed in a patient with X-linked juvenile retinoschisis complicated with neovascular glaucoma. Color fundus photography, fluorescein angiography (FFA), OCT and B-scan unveiled a rare condition of XLRS complicated with neovascular glaucoma. XLRS may complicate with neovascular glaucoma. It is necessary to test OCT, FFA, ERG and carefully examine the fundus of the follow eye when it comes to uncertain neovascular glaucoma of youth and child. And only in this way, can we exclude XLRS.

Renal involvement in the immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) disorder.

PubMed

Sheikine, Yuri; Woda, Craig B; Lee, Pui Y; Chatila, Talal A; Keles, Sevgi; Charbonnier, Louis-Marie; Schmidt, Birgitta; Rosen, Seymour; Rodig, Nancy M

2015-07-01

Immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) disorder is an autoimmune disease caused by loss-of-function mutations in the gene encoding the forkhead box P3 (FOXP3) transcription factor. These mutations affect the normal function of circulating regulatory T cells. IPEX is characterized by profound immune dysregulation leading to dermatitis, enteropathy, multiple endocrinopathies and failure to thrive. Different forms of renal injury have also been noted in these patients but these have been described to a very limited extent. Three patients with IPEX with characteristic renal findings and mutations in FOXP3, including one novel mutation, are described. Case presentations are followed by a review of the renal manifestations noted in IPEX and the range of therapeutic options for this disorder. We recommend that IPEX be considered in the differential diagnosis of young children who present with signs of immune dysregulation with a concomitant renal biopsy demonstrating immune complex deposition in a membranous-like pattern and/or interstitial nephritis.

Genotypic analysis of X-linked retinoschisis in Western Australia.

PubMed

Lamey, Tina; Laurin, Sarina; Chelva, Enid; De Roach, John

2010-01-01

X-linked Retinoschisis is a leading cause of juvenile macular degeneration. Four Western Australian families affected by X-Linked Retinoschisis were analysed using DNA and clinical information from the Australian Inherited Retinal Disease (IRD) Register and DNA Bank. By direct sequencing of the RS1 gene, three genetic variants were identified; 52+1G > T, 289T > G and 416delA. 289T > G has not been previously reported and is likely to cause a substitution of a membrane binding residue (W92G) in the functional discoidin domain. All clinically diagnosed individuals showed typical electronegative ERGs. The 52+1G > T obligate carrier also recorded a bilaterally abnormal rod ERG and mildly abnormal photopic responses. mfERG trace arrays showed reduced response densities in the paramacular region extending futher temporally for each eye.

Severe visual loss and cerebral infarction after injection of hyaluronic acid gel.

PubMed

Kim, Eung Gyu; Eom, Tae Kyung; Kang, Seok Joo

2014-01-01

We report a case of a 23-year-old man with cerebral infarction and permanent visual loss after injection of a hyaluronic acid gel filler for augmentation rhinoplasty. The patient was admitted to the hospital with complaints of loss of vision in the right eye, facial paralysis on the right side, and paralysis of the left limbs with severe pain during augmentation rhinoplasty with filler injection. Brain magnetic resonance imaging and computed tomography showed ophthalmic artery obstruction and right middle cerebral artery infarction. Acute thrombolysis was performed to treat the infarction; however, the patient's condition did not improve. Intracerebral hemorrhage in the right temporal/frontal/occipital/parietal lobe, subarachnoid hemorrhage, and midline shifting were observed on brain computed tomography after 24 hours after thrombolysis. Emergency decompressive craniectomy was performed. After the surgery, the patient continued to experience drowsiness, with no improvement in visual loss and motor weakness. Three months later, he could walk with cane. This case indicates that surgeons who administer filler injections should be familiar with the possibility of accidental intravascular injection and should explain the adverse effects of fillers to patients before surgery.

Pyoderma Gangrenosum–Like Ulcer in a Patient With X-Linked Agammaglobulinemia

PubMed Central

Murray, Patrick R.; Jain, Ashish; Uzel, Gulbu; Ranken, Raymond; Ivy, Cristina; Blyn, Lawrence B.; Ecker, David J.; Sampath, Rangarajan; Lee, Chyi-Chia Richard; Turner, Maria L.

2011-01-01

Background Pyoderma gangrenosum–like ulcers and cellulitis of the lower extremities associated with recurrent fevers in patients with X-linked (Bruton) agammaglobulinemia have been reported to be caused by Helicobacter bilis (formerly classified as Flexispira rappini and then Helicobacter strain flexispira taxon 8). Consistent themes in these reports are the difficulty in recovering this organism in blood and wound cultures and in maintaining isolates in vitro. We confirmed the presence of this organism in a patient’s culture by using a novel application of gene amplification polymerase chain reaction and electrospray ionization time-of-flight mass spectrometry. Observation An adolescent boy with X-linked agammaglobulinemia presented with indurated plaques and a chronic leg ulcer whose origin was strongly suspected to be an H bilis organism. Histologic analysis demonstrated positive Warthin-Starry staining of curvilinear rods, which grew in culture but failed to grow when sub-cultured. They could not be identified by conventional techniques. A combination of gene amplification by polymerase chain reaction and electrospray ionization time-of-flight mass spectrometry confirmed the identity of this organism. Conclusions This novel technology was useful in the identification of a difficult-to-grow Helicobacter organism, the cause of pyoderma gangrenosum–like leg ulcers in patients with X-linked agammaglobulinemia. Correct identification of this organism as the cause of pyoderma gangrenosum–like ulcers in patients with X-linked agammaglobulinemia is of great importance for the early initiation of appropriate and curative antibiotic therapy. PMID:20479300

Transcription map of Xq27: candidates for several X-linked diseases.

PubMed

Zucchi, I; Jones, J; Affer, M; Montagna, C; Redolfi, E; Susani, L; Vezzoni, P; Parvari, R; Schlessinger, D; Whyte, M P; Mumm, S

1999-04-15

Human Xq27 contains candidate regions for several disorders, yet is predicted to be a gene-poor cytogenetic band. We have developed a transcription map for the entire cytogenetic band to facilitate the identification of the relatively small number of expected candidate genes. Two approaches were taken to identify genes: (1) a group of 64 unique STSs that were generated during the physical mapping of the region were used in RT-PCR with RNA from human adult and fetal brain and (2) ESTs that have been broadly mapped to this region of the chromosome were finely mapped using a high-resolution yeast artificial chromosome contig. This combined approach identified four distinct regions of transcriptional activity within the Xq27 band. Among them is a region at the centromeric boundary that contains candidate regions for several rare developmental disorders (X-linked recessive hypoparathyroidism, thoracoabdominal syndrome, albinism-deafness syndrome, and Borjeson-Forssman-Lehman syndrome). Two transcriptionally active regions were identified in the center of Xq27 and include candidate regions for X-linked mental retardation syndrome 6, X-linked progressive cone dystrophy, X-linked retinitis pigmentosa 24, and a prostate cancer susceptibility locus. The fourth region of transcriptional activity encompasses the FMR1 (FRAXA) and FMR2 (FRAXE) genes. The analysis thus suggests clustered transcription in Xq27 and provides candidates for several heritable disorders for which the causative genes have not yet been found. Copyright 1999 Academic Press.

The Glenn A. Fry Award Lecture 2012: Plasticity of the Visual System Following Central Vision Loss

PubMed Central

Chung, Susana T. L.

2013-01-01

Following the onset of central vision loss, most patients develop an eccentric retinal location outside the affected macular region, the preferred retinal locus (PRL), as their new reference for visual tasks. The first goal of this paper is to present behavioral evidence showing the presence of experience-dependent plasticity in people with central vision loss. The evidence includes (1) the presence of oculomotor re-referencing of fixational saccades to the PRL; (2) the characteristics of the shape of the crowding zone (spatial region within which the presence of other objects affects the recognition of a target) at the PRL are more “foveal-like” instead of resembling those of the normal periphery; and (3) the change in the shape of the crowding zone at a para-PRL location that includes a component referenced to the PRL. These findings suggest that there is a shift in the referencing locus of the oculomotor and the sensory visual system from the fovea to the PRL for people with central vision loss, implying that the visual system for these individuals is still plastic and can be modified through experiences. The second goal of the paper is to demonstrate the feasibility of applying perceptual learning, which capitalizes on the presence of plasticity, as a tool to improve functional vision for people with central vision loss. Our finding that visual function could improve with perceptual learning presents an exciting possibility for the development of an alternative rehabilitative strategy for people with central vision loss. PMID:23670125

En face swept-source optical coherence tomographic analysis of X-linked juvenile retinoschisis.

PubMed

Ono, Shinji; Takahashi, Atsushi; Mase, Tomoko; Nagaoka, Taiji; Yoshida, Akitoshi

2016-07-01

To clarify the area of retinoschisis by X-linked juvenile retinoschisis (XLRS) using swept-source optical coherence tomography (SS-OCT) en face images. We report two cases of XLRS in the same family. The patients presented with bilateral blurred vision. The posterior segment examination showed a spoked-wheel pattern in the macula. SS-OCT cross-sectional images revealed widespread retinal splitting at the level of the inner nuclear layer bilaterally. We diagnosed XLRS. To evaluate the area of retinoschisis, we obtained en face SS-OCT images, which clearly visualized the area of retinoschisis seen as a sunflower-like structure in the macula. We report the findings on en face SS-OCT images from patients with XLRS. The en face images using SS-OCT showed the precise area of retinoschisis compared with the SS-OCT thickness map and are useful for managing patients with XLRS.

Fibroblast growth factor 23 in oncogenic osteomalacia and X-linked hypophosphatemia.

PubMed

Jonsson, Kenneth B; Zahradnik, Richard; Larsson, Tobias; White, Kenneth E; Sugimoto, Toshitsugu; Imanishi, Yasuo; Yamamoto, Takehisa; Hampson, Geeta; Koshiyama, Hiroyuki; Ljunggren, Osten; Oba, Koichi; Yang, In Myung; Miyauchi, Akimitsu; Econs, Michael J; Lavigne, Jeffrey; Jüppner, Harald

2003-04-24

Mutations in fibroblast growth factor 23 (FGF-23) cause autosomal dominant hypophosphatemic rickets. Clinical and laboratory findings in this disorder are similar to those in oncogenic osteomalacia, in which tumors abundantly express FGF-23 messenger RNA, and to those in X-linked hypophosphatemia, which is caused by inactivating mutations in a phosphate-regulating endopeptidase called PHEX. Recombinant FGF-23 induces phosphaturia and hypophosphatemia in vivo, suggesting that it has a role in phosphate regulation. To determine whether FGF-23 circulates in healthy persons and whether it is elevated in those with oncogenic osteomalacia or X-linked hypophosphatemia, an immunometric assay was developed to measure it. Using affinity-purified, polyclonal antibodies against [Tyr223]FGF-23(206-222)amide and [Tyr224]FGF-23(225-244)amide, we developed a two-site enzyme-linked immunosorbent assay that detects equivalently recombinant human FGF-23, the mutant form in which glutamine is substituted for arginine at position 179 (R179Q), and synthetic human FGF-23(207-244)amide. Plasma or serum samples from 147 healthy adults (mean [+/-SD] age, 48.4+/-19.6 years) and 26 healthy children (mean age, 10.9+/-5.5 years) and from 17 patients with oncogenic osteomalacia (mean age, 43.0+/-13.3 years) and 21 patients with X-linked hypophosphatemia (mean age, 34.9+/-17.2 years) were studied. Mean FGF-23 concentrations in the healthy adults and children were 55+/-50 and 69+/-36 reference units (RU) per milliliter, respectively. Four patients with oncogenic osteomalacia had concentrations ranging from 426 to 7970 RU per milliliter, which normalized after tumor resection. FGF-23 concentrations were 481+/-528 RU per milliliter in those with suspected oncogenic osteomalacia and 353+/-510 RU per milliliter (range, 31 to 2335) in those with X-linked hypophosphatemia. FGF-23 is readily detectable in the plasma or serum of healthy persons and can be markedly elevated in those with oncogenic

Recognizing patterns of visual field loss using unsupervised machine learning

NASA Astrophysics Data System (ADS)

Yousefi, Siamak; Goldbaum, Michael H.; Zangwill, Linda M.; Medeiros, Felipe A.; Bowd, Christopher

2014-03-01

Glaucoma is a potentially blinding optic neuropathy that results in a decrease in visual sensitivity. Visual field abnormalities (decreased visual sensitivity on psychophysical tests) are the primary means of glaucoma diagnosis. One form of visual field testing is Frequency Doubling Technology (FDT) that tests sensitivity at 52 points within the visual field. Like other psychophysical tests used in clinical practice, FDT results yield specific patterns of defect indicative of the disease. We used Gaussian Mixture Model with Expectation Maximization (GEM), (EM is used to estimate the model parameters) to automatically separate FDT data into clusters of normal and abnormal eyes. Principal component analysis (PCA) was used to decompose each cluster into different axes (patterns). FDT measurements were obtained from 1,190 eyes with normal FDT results and 786 eyes with abnormal (i.e., glaucomatous) FDT results, recruited from a university-based, longitudinal, multi-center, clinical study on glaucoma. The GEM input was the 52-point FDT threshold sensitivities for all eyes. The optimal GEM model separated the FDT fields into 3 clusters. Cluster 1 contained 94% normal fields (94% specificity) and clusters 2 and 3 combined, contained 77% abnormal fields (77% sensitivity). For clusters 1, 2 and 3 the optimal number of PCA-identified axes were 2, 2 and 5, respectively. GEM with PCA successfully separated FDT fields from healthy and glaucoma eyes and identified familiar glaucomatous patterns of loss.

Expression pattern of X-linked genes in sex chromosome aneuploid bovine cells.

PubMed

Basrur, Parvathi K; Farazmand, Ali; Stranzinger, Gerald; Graphodatskaya, Daria; Reyes, Ed R; King, W Allan

2004-01-01

Expression of the X-inactive specific transcript (XIST) gene is a prerequisite step for dosage compensation in mammals, accomplished by silencing one of the two X chromosomes in normal female diploid cells or all X chromosomes in excess of one in sex chromosome aneuploids. Our previous studies showing that XIST expression does not eventuate the inactivation of X-linked genes in fetal bovine testis had suggested that XIST expression may not be an indicator of X inactivation in this species. In this study, we used a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) approach on cultures of bovine cells with varying sex chromosome constitution (XY, XX, XXY and XXX) to test whether the levels of XIST expressed conform to the number of late replicating (inactive) X chromosomes displayed by proliferating cells in these cultures. Expression patterns of four X-linked genes, including hypoxanthine phosphorybosyl transferase (HPRT), glucose-6-phosphate dehydrogenase (G6PD), zinc finger protein locus on the X (ZFX). and 'selected mouse cDNA on the X' (SMCX), in all these cells were also tested. Results showed that XIST expression was significantly higher (p < 0.05) in XXX cells compared to XX and XXY cells and that G6PD. HPRT, and SMCX loci are subject to X inactivation. The significantly higher levels of ZFX expressed in XXX cells compared to XX and XXY cells (p < 0.05) confirmed that this bovine locus, as human ZFX, escapes X inactivation. However, the levels of XIST and ZFX expressed were not proportional to the X chromosome load in these cells suggesting that X-linked loci escaping inactivation may be regulated at transcription (or post-transcription) level by mechanisms that prevent gene-specific product accumulation beyond certain levels in sex chromosome aneuploids.

Non-line-of-sight ultraviolet link loss in noncoplanar geometry.

PubMed

Wang, Leijie; Xu, Zhengyuan; Sadler, Brian M

2010-04-15

Various path loss models have been developed for solar blind non-line-of-sight UV communication links under an assumption of coplanar source beam axis and receiver pointing direction. This work further extends an existing single-scattering coplanar analytical model to noncoplanar geometry. The model is derived as a function of geometric parameters and atmospheric characteristics. Its behavior is numerically studied in different noncoplanar geometric settings.

Loss of calretinin immunoreactive fibers in subcortical visual recipient structures of the RCS dystrophic rat.

PubMed

Vugler, Anthony A; Coffey, Peter J

2003-11-01

The retinae of dystrophic Royal College of Surgeons (RCS) rats exhibit progressive photoreceptor degeneration accompanied by pathology of ganglion cells. To date, little work has examined the consequences of retinal degeneration for central visual structures in dystrophic rats. Here, we use immunohistochemistry for calretinin (CR) to label retinal afferents in the superior colliculus (SC), lateral geniculate nucleus, and olivary pretectal nucleus of RCS rats aged between 2 and 26 months of age. Early indications of fiber loss in the medial dystrophic SC were apparent between 9 and 13 months. Quantitative methods reveal a significant reduction in the level of CR immunoreactivity in visual layers of the medial dystrophic SC at 13 months (P < 0.02). In dystrophic animals aged 19-26 months the loss of CR fibers in SC was dramatic, with well-defined patches of fiber degeneration predominating in medial aspects of the structure. This fiber degeneration in SC was accompanied by increased detection of cells immunoreactive for CR. In several animals, regions of fiber loss were also found to contain strongly parvalbumin-immunoreactive cells. Loss of CR fibers was also observed in the lateral geniculate nucleus and olivary pretectal nucleus. Patterns of fiber loss in the dystrophic SC compliment reports of ganglion cell degeneration in these animals and the response of collicular neurons to degeneration is discussed in terms of plasticity of the dystrophic visual system and properties of calcium binding proteins.

Splice loss requirements in multi-mode fiber mode-division-multiplex transmission links.

PubMed

Warm, Stefan; Petermann, Klaus

2013-01-14

We investigate numerically the influence of fiber splices and fiber connectors to the statistics of mode dependent loss (MDL) and multiple-input multiple-output (MIMO) outage capacity in mode multiplexed multi-mode fiber links. Our results indicate required splice losses much lower than currently feasible to achieve a reasonable outage capacity in long-haul transmission systems. Splice losses as low as 0.03dB may effectively lead to an outage of MIMO channels after only a few hundred kilometers transmission length. In a first approximation, the relative capacity solely depends on the accumulated splice loss and should be less than ≈ 2dB to ensure a relative capacity of 90%. We also show that discrete mode permutation (mixing) within the transmission line may effectively increase the maximum transmission distance by a factor of 5 for conventional splice losses.

X-linked cardiomyopathy is heterogeneous

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, M.J.; Sillence, D.O.; Mulley, J.C.

Two major loci of X-linked cardiomyopathy have been mapped by linkage analysis. The gene for X-linked dilated cardiomyopathy (XLCM) is mapped to the dystrophin locus at Xp21, while Barth syndrome has been localised to distal Xq28. XLCM usually presents in juvenile males with no skeletal disease but decreased dystrophin in cardiac muscle. Barth syndrome most often presents in infants and is characterized by skeletal myopathy, short stature and neutropenia in association with cardiomyopathy of variable severity. Prior to carrier or prenatal diagnosis in a family, delineation of the cardiomyopathy locus involved is essential. We report the linkage mapping of amore » large kindred in which several male infants have died with hypertrophic cardiomyopathy. There is a family history of unexplained death of infant males less than 6 months old over 4 generations. Features of Barth syndrome such as short stature, skeletal myopathy and neutropenia have not been observed. Genotyping at 10 marker loci in Xq28 has revealed significant pairwise lod scores with the cardiomyopathy phenotype at DXS52 (Z=2.21 at {theta}=0.0), at markers p26 and p39 near DXS15 (Z=2.30 at {theta}=0.0) and at F8C (Z=2.24 at {theta}=0.0). A recombinant detected with DXS296 defines the proximal limit to the localization. No recombinants were detected at any of the loci distal to DXS296. The most distal marker in Xq28, DXS1108, is within 500 kb of the telomere. As the gene in this family is localized to Xq28, it is possible that this disorder is an allelic variant at the Barth syndrome locus.« less

X-Linked Intellectual Disability: Unique Vulnerability of the Male Genome

ERIC Educational Resources Information Center

Stevenson, Roger E.; Schwartz, Charles E.

2009-01-01

X-linked intellectual disability (XLID) accounts for approximately 16% of males with intellectual disability (ID). This is, in part, related to the fact that males have a single X chromosome. Progress in the clinical and molecular characterization of XLID has outpaced progress in the delineation of ID due to genes on the other 22 chromosomes.…

Silencing of X-Linked MicroRNAs by Meiotic Sex Chromosome Inactivation

PubMed Central

Royo, Hélène; Seitz, Hervé; ElInati, Elias; Peters, Antoine H. F. M.; Stadler, Michael B.; Turner, James M. A.

2015-01-01

During the pachytene stage of meiosis in male mammals, the X and Y chromosomes are transcriptionally silenced by Meiotic Sex Chromosome Inactivation (MSCI). MSCI is conserved in therian mammals and is essential for normal male fertility. Transcriptomics approaches have demonstrated that in mice, most or all protein-coding genes on the X chromosome are subject to MSCI. However, it is unclear whether X-linked non-coding RNAs behave in a similar manner. The X chromosome is enriched in microRNA (miRNA) genes, with many exhibiting testis-biased expression. Importantly, high expression levels of X-linked miRNAs (X-miRNAs) have been reported in pachytene spermatocytes, indicating that these genes may escape MSCI, and perhaps play a role in the XY-silencing process. Here we use RNA FISH to examine X-miRNA expression in the male germ line. We find that, like protein-coding X-genes, X-miRNAs are expressed prior to prophase I and are thereafter silenced during pachynema. X-miRNA silencing does not occur in mouse models with defective MSCI. Furthermore, X-miRNAs are expressed at pachynema when present as autosomally integrated transgenes. Thus, we conclude that silencing of X-miRNAs during pachynema in wild type males is MSCI-dependent. Importantly, misexpression of X-miRNAs during pachynema causes spermatogenic defects. We propose that MSCI represents a chromosomal mechanism by which X-miRNAs, and other potential X-encoded repressors, can be silenced, thereby regulating genes with critical late spermatogenic functions. PMID:26509798

Investigations of Polarization Dependent Loss in Polarization Modulated Analog Optical Links

DTIC Science & Technology

2015-12-29

including theory. The general system is discussed as well as the details for measuring and calculating polarization dependent loss in the system. A...modulation link setup…………………………………………………. 5 2.3 PDL Measurement Routine…………………………………………………………. 6 3 MISALIGNING THE MODULATION ARC...nonlinearities due to polarization distortion loss (PDL). A method for measuring PDL within the system is detailed. A number of experiments are performed

Mutational studies in X-linked Charcot-Marie-Tooth disease (CMTX)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherryson, A.K.; Yeung, L.; Kennerson, M.L.

1994-09-01

Charcot-Marie-Tooth disease, also known as hereditary motor and sensory neuropathy (HMSN), is a heterogeneous group of slowly progressive disorders of the peripheral nerve. X-linked CMT (CMTX) is characterized by slow motor nerve conduction velocities in affected males and the presence of mildly affected or normal carrier females with intermediate or normal nerve conduction velocities. CMTX, which has an incidence of 3.1 per 100,000 and accounts for approximately 10% of CMT cases, has been mapped to Xq13. One of the genes lying in this region, connexin 32, has been found to contain alterations in individuals affected with X-linked CMT. We havemore » identified our X-linked families from dominant type 1 CMT families using the clinical criteria given above. These families were screened for point mutations in connexin 32. We have identified three missense mutations, a G{r_arrow}A transition at amino acid 35 (valine to methionine), a C{r_arrow}G transition at amino acid 158 (proline to alanine) and a T{r_arrow}A transition at amino acid 182 (serine to threonine). Another family showed a 18 bp deletion, which removed the amino acid 111 to 116 inclusive (histidine, glycine, aspartic acid, proline, leucine, histidine).« less

CLMSVault: A Software Suite for Protein Cross-Linking Mass-Spectrometry Data Analysis and Visualization.

PubMed

Courcelles, Mathieu; Coulombe-Huntington, Jasmin; Cossette, Émilie; Gingras, Anne-Claude; Thibault, Pierre; Tyers, Mike

2017-07-07

Protein cross-linking mass spectrometry (CL-MS) enables the sensitive detection of protein interactions and the inference of protein complex topology. The detection of chemical cross-links between protein residues can identify intra- and interprotein contact sites or provide physical constraints for molecular modeling of protein structure. Recent innovations in cross-linker design, sample preparation, mass spectrometry, and software tools have significantly improved CL-MS approaches. Although a number of algorithms now exist for the identification of cross-linked peptides from mass spectral data, a dearth of user-friendly analysis tools represent a practical bottleneck to the broad adoption of the approach. To facilitate the analysis of CL-MS data, we developed CLMSVault, a software suite designed to leverage existing CL-MS algorithms and provide intuitive and flexible tools for cross-platform data interpretation. CLMSVault stores and combines complementary information obtained from different cross-linkers and search algorithms. CLMSVault provides filtering, comparison, and visualization tools to support CL-MS analyses and includes a workflow for label-free quantification of cross-linked peptides. An embedded 3D viewer enables the visualization of quantitative data and the mapping of cross-linked sites onto PDB structural models. We demonstrate the application of CLMSVault for the analysis of a noncovalent Cdc34-ubiquitin protein complex cross-linked under different conditions. CLMSVault is open-source software (available at https://gitlab.com/courcelm/clmsvault.git ), and a live demo is available at http://democlmsvault.tyerslab.com/ .

Novel mutations of the RS1 gene in a cohort of Chinese families with X-linked retinoschisis

PubMed Central

Chen, Jieqiong; Xu, Ke; Zhang, Xiaohui; Pan, Zhe; Dong, Bing

2014-01-01

Purpose X-linked retinoschisis is a retinal dystrophy caused by mutations in the RS1 gene in Xp22.1. These mutations lead to schisis (splitting) of the neural retina and subsequent reduction in visual acuity in affected men (OMIM # 312700). The aim of this study was to identify the RS1 gene mutations in a cohort of Chinese patients with X-linked retinoschisis, and to describe the associated phenotypes. Methods Patients and unaffected individuals from 16 unrelated families underwent detailed ophthalmic examinations. After informed consent was obtained, genomic DNA was extracted from the venous blood of all participants. All exons including the exon-intron boundaries of the RS1 gene, were amplified by PCR and the products were analyzed by direct sequencing. Long-range PCR followed by DNA sequencing was used to define the breakpoints of the large deletion. Results Sixteen male individuals from 16 families were diagnosed with retinoschisis by clinical examination. The median age at review was 13.2 years (range: 5–34 years); the median best-corrected visual acuity upon review was 0.26 (range 0.02–1.0). Foveal schisis was found in 82.8% of the eyes (24/29) while peripheral schisis was present in 27.5% of the eyes (8/29). Sequencing of the RS1 gene identified 16 mutations, nine of which were novel. The mutations included eight missense mutations, all located in exons 4–6 (50.0%), two nonsense mutations (12.5%), four small deletions or insertions (25.0%), one splice site mutation (6.25%), and one large genomic deletion that included exon1 (6.25%). Conclusions The mutations found in our study broaden the spectrum of RS1 mutations. The identification of the specific mutation in each pedigree will allow future determination of female carrier status for genetic counseling purposes. PMID:24505212

Severe X-linked chondrodysplasia punctata in nine new female fetuses.

PubMed

Lefebvre, Mathilde; Dufernez, Fabienne; Bruel, Ange-Line; Gonzales, Marie; Aral, Bernard; Saint-Onge, Judith; Gigot, Nadège; Desir, Julie; Daelemans, Caroline; Jossic, Frédérique; Schmitt, Sébastien; Mangione, Raphaele; Pelluard, Fanny; Vincent-Delorme, Catherine; Labaune, Jean-Marc; Bigi, Nicole; D'Olne, Dominique; Delezoide, Anne-Lise; Toutain, Annick; Blesson, Sophie; Cormier-Daire, Valérie; Thevenon, Julien; El Chehadeh, Salima; Masurel-Paulet, Alice; Joyé, Nicole; Vibert-Guigue, Claude; Rigonnot, Luc; Rousseau, Thierry; Vabres, Pierre; Hervé, Philippe; Lamazière, Antonin; Rivière, Jean-Baptiste; Faivre, Laurence; Laurent, Nicole; Thauvin-Robinet, Christel

2015-07-01

Conradi-Hünermann-Happle [X-linked dominant chondrodysplasia punctata 2 (CDPX2)] syndrome is a rare X-linked dominant skeletal dysplasia usually lethal in men while affected women show wide clinical heterogeneity. Different EBP mutations have been reported. Severe female cases have rarely been reported, with only six antenatal presentations. To better characterize the phenotype in female fetuses, we included nine antenatally diagnosed cases of women with EBP mutations. All cases were de novo except for two fetuses with an affected mother and one case of germinal mosaicism. The mean age at diagnosis was 22 weeks of gestation. The ultrasound features mainly included bone abnormalities: shortening (8/9 cases) and bowing of the long bones (5/9), punctuate epiphysis (7/9) and an irregular aspect of the spine (5/9). Postnatal X-rays and examination showed ichthyosis (8/9) and epiphyseal stippling (9/9), with frequent asymmetric short and bowed long bones. The X-inactivation pattern of the familial case revealed skewed X-inactivation in the mildly symptomatic mother and random X-inactivation in the severe fetal case. Differently affected skin samples of the same fetus revealed different patterns of X-inactivation. Prenatal detection of asymmetric shortening and bowing of the long bones and cartilage stippling should raise the possibility of CPDX2 in female fetuses, especially because the majority of such cases involve de novo mutations. © 2015 John Wiley & Sons, Ltd.

Genetics Home Reference: X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia

MedlinePlus

... Share: Email Facebook Twitter Home Health Conditions XMEN X-linked immunodeficiency with magnesium defect, Epstein-Barr virus ... Javascript to view the expand/collapse boxes. Description X-linked immunodeficiency with magnesium defect, Epstein-Barr virus ...

Causes and anatomical site of blindness and severe visual loss in Isfahan, Islamic Republic of Iran.

PubMed

Dehghan, A; Kianersi, F; Moazam, E; Ghanbari, H

2010-02-01

This study in 2005 evaluated the causes and major anatomical site of blindness and severe visual loss at a school for blind children in Isfahan province, Islamic Republic of Iran. All 211 students were examined according to the modified WHO/PBL eye examination record: 70.4% were blind, 24.3% had severe visual loss and 5.3% were visually impaired. The major causes of abnormality were hereditary factors (42.7%), prenatal/neonatal (18.5%) and unknown etiology (35.5%). The main sites of abnormality were the retina (62.6%), whole globe (17.5%), lens (7.1%) and optic nerve (7.1%). A high proportion of parents were in a consanguineous marriage (49.2%). The pattern of blindness in Isfahan encompasses characteristics of both developed and developing countries.

ProXL (Protein Cross-Linking Database): A Platform for Analysis, Visualization, and Sharing of Protein Cross-Linking Mass Spectrometry Data

PubMed Central

2016-01-01

ProXL is a Web application and accompanying database designed for sharing, visualizing, and analyzing bottom-up protein cross-linking mass spectrometry data with an emphasis on structural analysis and quality control. ProXL is designed to be independent of any particular software pipeline. The import process is simplified by the use of the ProXL XML data format, which shields developers of data importers from the relative complexity of the relational database schema. The database and Web interfaces function equally well for any software pipeline and allow data from disparate pipelines to be merged and contrasted. ProXL includes robust public and private data sharing capabilities, including a project-based interface designed to ensure security and facilitate collaboration among multiple researchers. ProXL provides multiple interactive and highly dynamic data visualizations that facilitate structural-based analysis of the observed cross-links as well as quality control. ProXL is open-source, well-documented, and freely available at https://github.com/yeastrc/proxl-web-app. PMID:27302480

ProXL (Protein Cross-Linking Database): A Platform for Analysis, Visualization, and Sharing of Protein Cross-Linking Mass Spectrometry Data.

PubMed

Riffle, Michael; Jaschob, Daniel; Zelter, Alex; Davis, Trisha N

2016-08-05

ProXL is a Web application and accompanying database designed for sharing, visualizing, and analyzing bottom-up protein cross-linking mass spectrometry data with an emphasis on structural analysis and quality control. ProXL is designed to be independent of any particular software pipeline. The import process is simplified by the use of the ProXL XML data format, which shields developers of data importers from the relative complexity of the relational database schema. The database and Web interfaces function equally well for any software pipeline and allow data from disparate pipelines to be merged and contrasted. ProXL includes robust public and private data sharing capabilities, including a project-based interface designed to ensure security and facilitate collaboration among multiple researchers. ProXL provides multiple interactive and highly dynamic data visualizations that facilitate structural-based analysis of the observed cross-links as well as quality control. ProXL is open-source, well-documented, and freely available at https://github.com/yeastrc/proxl-web-app .

Molecular genetic analysis of patients with sporadic and X-linked infantile nystagmus

PubMed Central

Zhao, Hui; Huang, Xiu-Feng; Zheng, Zhi-Li; Deng, Wen-Li; Lei, Xin-Lan; Xing, Dong-Jun; Ye, Liang; Xu, Su-Zhong; Chen, Jie; Zhang, Fang; Yu, Xin-Ping; Jin, Zi-Bing

2016-01-01

Objectives Infantile nystagmus (IN) is a genetically heterogeneous condition characterised by involuntary rhythmic oscillations of the eyes accompanied by different degrees of vision impairment. Two genes have been identified as mainly causing IN: FRMD7 and GPR143. The aim of our study was to identify the genetic basis of both sporadic IN and X-linked IN. Design Prospective analysis. Patients Twenty Chinese patients, including 15 sporadic IN cases and 5 from X-linked IN families, were recruited and underwent molecular genetic analysis. We first performed PCR-based DNA sequencing of the entire coding region and the splice junctions of the FRMD7 and GPR143 genes in participants. Mutational analysis and co-segregation confirmation were then performed. Setting All clinical examinations and genetic experiments were performed in the Eye Hospital of Wenzhou Medical University. Results Two mutations in the FRMD7 gene, including one novel nonsense mutation (c.1090C>T, p.Q364X) and one reported missense mutation (c.781C>G, p.R261G), were identified in two of the five (40%) X-linked IN families. However, none of putative mutations were identified in FRMD7 or GPR143 in any of the sporadic cases. Conclusions The results suggest that mutations in FRMD7 appeared to be the major genetic cause of X-linked IN, but not of sporadic IN. Our findings provide further insights into FRMD7 mutations, which could be helpful for future genetic diagnosis and genetic counselling of Chinese patients with nystagmus. PMID:27036142

Loss of the Endothelial Glycocalyx Links Albuminuria and Vascular Dysfunction

PubMed Central

Ferguson, Joanne K.; Burford, James L.; Gevorgyan, Haykanush; Nakano, Daisuke; Harper, Steven J.; Bates, David O.; Peti-Peterdi, Janos

2012-01-01

Patients with albuminuria and CKD frequently have vascular dysfunction but the underlying mechanisms remain unclear. Because the endothelial surface layer, a meshwork of surface-bound and loosely adherent glycosaminoglycans and proteoglycans, modulates vascular function, its loss could contribute to both renal and systemic vascular dysfunction in proteinuric CKD. Using Munich-Wistar-Fromter (MWF) rats as a model of spontaneous albuminuric CKD, multiphoton fluorescence imaging and single-vessel physiology measurements revealed that old MWF rats exhibited widespread loss of the endothelial surface layer in parallel with defects in microvascular permeability to both water and albumin, in both continuous mesenteric microvessels and fenestrated glomerular microvessels. In contrast to young MWF rats, enzymatic disruption of the endothelial surface layer in old MWF rats resulted in neither additional loss of the layer nor additional changes in permeability. Intravenous injection of wheat germ agglutinin lectin and its adsorption onto the endothelial surface layer significantly improved glomerular albumin permeability. Taken together, these results suggest that widespread loss of the endothelial surface layer links albuminuric kidney disease with systemic vascular dysfunction, providing a potential therapeutic target for proteinuric kidney disease. PMID:22797190

Energetic Particle Loss Estimates in W7-X

NASA Astrophysics Data System (ADS)

Lazerson, Samuel; Akaslompolo, Simppa; Drevlak, Micheal; Wolf, Robert; Darrow, Douglass; Gates, David; W7-X Team

2017-10-01

The collisionless loss of high energy H+ and D+ ions in the W7-X device are examined using the BEAMS3D code. Simulations of collisionless losses are performed for a large ensemble of particles distributed over various flux surfaces. A clear loss cone of particles is present in the distribution for all particles. These simulations are compared against slowing down simulations in which electron impact, ion impact, and pitch angle scattering are considered. Full device simulations allow tracing of particle trajectories to the first wall components. These simulations provide estimates for placement of a novel set of energetic particle detectors. Recent performance upgrades to the code are allowing simulations with > 1000 processors providing high fidelity simulations. Speedup and future works are discussed. DE-AC02-09CH11466.

Novel mutations in the connexin 32 gene associated with X-linked Charcot-Marie-Tooth disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, C.; Ainsworth, P.

1994-09-01

Charcot-Marie-Tooth disease is a pathologically and genetically hetergenous group of disorders that cause a progressive neuropathy, defined pathologically by degeneration of the myelin (CMT 1) of the axon (CMT 2) of the peripheral nerves. An X-linked type of the demyelinating form of this disorder (CMT X) has recently been linked to mutations in the connexin 32 (Cx32) gene, which codes for a 284 amino acid gap junction protein found in myelinated peripheral nerve. To date some 7 different mutations in this gene have been identified as being responsible for CMT X. The majority of these predict nonconservative amino acid substitutions,more » while one is a frameshift mutation which predicts a premature stop at codon 21. We report the results of molecular studies on three further local CMT X kindreds. The Cx32 gene was amplified by PCR in three overlapping fragments 300-450 bp in length using leukocyte-derived DNA as template. These were either sequenced directly using a deaza dGTP sequencing protocol, or were cloned and sequenced using a TA vector. In two of the kindreds the affected members carried a point mutation which was predicted to effect a non-conservative amino acid change within the first transmembrane domain. Both of these mutations caused a restriction site alteration (the loss of an Nla III and the creation of a Pvu II, respectively), and the former mutation was observed to segregate with the clinicial phenotype in affected family members. Affected members of the third kindred, which was a very large multigenerational family that had been extensively studied previously, were shown to carry a point mutation predicted to cause a premature truncation of the Cx32 gene product in the intracellular carboxy terminus. This mutation obliterated an Rsa I site which allowed a rapid screen of several other family members.« less

X-linked intellectual disability update 2017.

PubMed

Neri, Giovanni; Schwartz, Charles E; Lubs, Herbert A; Stevenson, Roger E

2018-04-25

The X-chromosome comprises only about 5% of the human genome but accounts for about 15% of the genes currently known to be associated with intellectual disability. The early progress in identifying the X-linked intellectual disability (XLID)-associated genes through linkage analysis and candidate gene sequencing has been accelerated with the use of high-throughput technologies. In the 10 years since the last update, the number of genes associated with XLID has increased by 96% from 72 to 141 and duplications of all 141 XLID genes have been described, primarily through the application of high-resolution microarrays and next generation sequencing. The progress in identifying genetic and genomic alterations associated with XLID has not been matched with insights that improve the clinician's ability to form differential diagnoses, that bring into view the possibility of curative therapies for patients, or that inform scientists of the impact of the genetic alterations on cell organization and function. © 2018 Wiley Periodicals, Inc.

Role of Visual Speech in Phonological Processing by Children with Hearing Loss

ERIC Educational Resources Information Center

Jerger, Susan; Tye-Murray, Nancy; Abdi, Herve

2009-01-01

Purpose: This research assessed the influence of visual speech on phonological processing by children with hearing loss (HL). Method: Children with HL and children with normal hearing (NH) named pictures while attempting to ignore auditory or audiovisual speech distractors whose onsets relative to the pictures were either congruent, conflicting in…

A family study of congenital X linked sideroblastic anaemia.

PubMed Central

Holmes, J; May, A; Geddes, D; Jacobs, A

1990-01-01

We report on the cytogenetic findings in a family study of pyridoxine responsive, X linked sideroblastic anaemia. An increase in the number of X chromosomes was observed in a small proportion of metaphases prepared from five female members, but these findings did not strictly correlate with the carrier status of the condition. No consistent cytogenetic abnormality could be identified or associated with this rare familial condition. The diagnosis and counselling of carriers of this condition is discussed. Images PMID:2308152

Novel Phenotypic and Genotypic Findings in X-Linked Retinoschisis

PubMed Central

Tsang, Stephen H.; Vaclavik, Veronika; Bird, Alan C.; Robson, Anthony G.; Holder, Graham E.

2009-01-01

Objective To describe atypical phenotypes associated with the retinoschisis (X-linked, juvenile) 1 mutation (RS1). Methods Seven patients with multiple fine white dots at the macula and reduced visual acuity were evaluated. Six patients underwent pattern and full-field electroretinography (ERG). On-off ERG, optical coherence tomography, and fundus autofluorescence imaging were performed in some patients. Mutational screening of RS1 was prompted by the ERG findings. Results Fine white dots resembling drusenlike deposits and sometimes associated with retinal pigment epithelial abnormalities were present in the maculae. An electronegative bright-flash ERG configuration was present in all patients tested, and abnormal pattern ERG findings confirmed macular dysfunction. A parafoveal ring of high-density autofluorescence was present in 3 eyes; 1 patient showed high-density foci concordant with the white dots. Optical coherence tomography did not show foveal schisis in 3 of 4 eyes. All patients carried mutations in RS1, including 1 with a novel 206T→C mutation in exon 4. Conclusions Multiple fine white dots at the macula may be the initial fundus feature in RS1 mutation. Electrophysiologic findings suggest dysfunction after phototransduction and enable focused mutational screening. Autofluorescence imaging results suggest early retinal pigment epithelium involvement; a parafoveal ring of high-density autofluorescence has not previously been described in this disorder. PMID:17296904

Phenotypic Characteristics of a French Cohort of Patients with X-Linked Retinoschisis.

PubMed

Orès, Raphaëlle; Mohand-Said, Saddek; Dhaenens, Claire-Marie; Antonio, Aline; Zeitz, Christina; Augstburger, Edouard; Andrieu, Camille; Sahel, José-Alain; Audo, Isabelle

2018-05-05

To analyze the retinal structure in patients with X-linked retinoschisis (XLRS) using spectral-domain OCT and to correlate the morphologic findings with visual acuity, electroretinographic results, and patient age. Retrospective, observational study. Data from 52 consecutive male patients with molecularly confirmed XLRS were collected retrospectively. Complete clinical evaluation included best-corrected visual acuity, full-field electroretinography, fundus photography, spectral-domain OCT, and fundus autofluorescence. Spectral-domain OCT images were analyzed to determine full thickness of the retina and tomographic structural changes. Relationships between age, OCT, and visual acuity were assessed. One hundred four eyes of 52 patients were included. The mean age at inclusion was 24±15 years (range, 3-57 years). The best-corrected visual acuity ranged from no light perception to 0.1 logarithm of the minimum angle of resolution (mean, 0.6±0.38 logarithm of the minimum angle of resolution). Macular schisis was found in 88% of eyes and macular atrophy was found in 11% of eyes, whereas peripheral schisis was present in 30% of eyes. A spoke-wheel pattern of high and low intensity was the most frequently observed fundus autofluorescence abnormality (51/94 eyes [54%]). The b-to-a amplitude ratio on bright-flash dark-adapted electroretinography was reduced significantly in 45 of 64 eyes (70%). Spectral-domain OCT was available for 97 eyes and showed foveoschisis in 76 of 97 eyes (78%), parafoveal schisis in 10 of 97 eyes (10%), and foveal atrophy in 11 of 97 eyes (11%). Mean central macular thickness (CMT) was of 373.6±140 μm. Cystoid changes were localized mainly in the inner nuclear layer (85/97 eyes [88%]). Qualitative defects in photoreceptor structures were found in most eyes (79/97 eyes [81%]), and the most frequent abnormality was an interruption of the photoreceptor cell outer segment tips (79/79 eyes [100%]). Older age correlated well with lower CMT

Optical coherence tomography in the diagnosis of juvenile X-linked retinoschisis.

PubMed

Eriksson, Urban; Larsson, Eva; Holmström, Gerd

2004-04-01

To describe the value of optical coherence tomography (OCT) as a diagnostic tool in the diagnosis of X-linked retinoschisis. We report three boys aged between 8 and 17 years, diagnosed with X-linked retinoschisis. During investigations they were examined with OCT (Zeiss Humphrey OCT 1, upgraded version). Single scans of the central posterior pole and the region around the vascular arcades were obtained. Two of the boys underwent full-field ERG according to ISCEV standards. Genetic analysis was performed in all three boys, with sequencing of the XLRS gene. The OCT results revealed a pattern with a cleavage of the retina in two distinct planes, one deep (outer retina) and one superficial. This was very obvious in one patient and a similar but not as pronounced pattern was seen in the other two cases. The two layers were superficially connected with thin-walled, vertical palisades, separated by low reflective, cystoid spaces, confluent and most prominent in the foveal region. Full-field ERG and/or DNA analysis are well known methods used for diagnosis of X-linked juvenile retinoschisis. In this paper, we suggest that OCT can also be a helpful diagnostic tool.

X-linked cataract and Nance-Horan syndrome are allelic disorders.

PubMed

Coccia, Margherita; Brooks, Simon P; Webb, Tom R; Christodoulou, Katja; Wozniak, Izabella O; Murday, Victoria; Balicki, Martha; Yee, Harris A; Wangensteen, Teresia; Riise, Ruth; Saggar, Anand K; Park, Soo-Mi; Kanuga, Naheed; Francis, Peter J; Maher, Eamonn R; Moore, Anthony T; Russell-Eggitt, Isabelle M; Hardcastle, Alison J

2009-07-15

Nance-Horan syndrome (NHS) is an X-linked developmental disorder characterized by congenital cataract, dental anomalies, facial dysmorphism and, in some cases, mental retardation. Protein truncation mutations in a novel gene (NHS) have been identified in patients with this syndrome. We previously mapped X-linked congenital cataract (CXN) in one family to an interval on chromosome Xp22.13 which encompasses the NHS locus; however, no mutations were identified in the NHS gene. In this study, we show that NHS and X-linked cataract are allelic diseases. Two CXN families, which were negative for mutations in the NHS gene, were further analysed using array comparative genomic hybridization. CXN was found to be caused by novel copy number variations: a complex duplication-triplication re-arrangement and an intragenic deletion, predicted to result in altered transcriptional regulation of the NHS gene. Furthermore, we also describe the clinical and molecular analysis of seven families diagnosed with NHS, identifying four novel protein truncation mutations and a novel large deletion encompassing the majority of the NHS gene, all leading to no functional protein. We therefore show that different mechanisms, aberrant transcription of the NHS gene or no functional NHS protein, lead to different diseases. Our data highlight the importance of copy number variation and non-recurrent re-arrangements leading to different severity of disease and describe the potential mechanisms involved.

X-linked cataract and Nance-Horan syndrome are allelic disorders

PubMed Central

Coccia, Margherita; Brooks, Simon P.; Webb, Tom R.; Christodoulou, Katja; Wozniak, Izabella O.; Murday, Victoria; Balicki, Martha; Yee, Harris A.; Wangensteen, Teresia; Riise, Ruth; Saggar, Anand K.; Park, Soo-Mi; Kanuga, Naheed; Francis, Peter J.; Maher, Eamonn R.; Moore, Anthony T.; Russell-Eggitt, Isabelle M.; Hardcastle, Alison J.

2009-01-01

Nance-Horan syndrome (NHS) is an X-linked developmental disorder characterized by congenital cataract, dental anomalies, facial dysmorphism and, in some cases, mental retardation. Protein truncation mutations in a novel gene (NHS) have been identified in patients with this syndrome. We previously mapped X-linked congenital cataract (CXN) in one family to an interval on chromosome Xp22.13 which encompasses the NHS locus; however, no mutations were identified in the NHS gene. In this study, we show that NHS and X-linked cataract are allelic diseases. Two CXN families, which were negative for mutations in the NHS gene, were further analysed using array comparative genomic hybridization. CXN was found to be caused by novel copy number variations: a complex duplication–triplication re-arrangement and an intragenic deletion, predicted to result in altered transcriptional regulation of the NHS gene. Furthermore, we also describe the clinical and molecular analysis of seven families diagnosed with NHS, identifying four novel protein truncation mutations and a novel large deletion encompassing the majority of the NHS gene, all leading to no functional protein. We therefore show that different mechanisms, aberrant transcription of the NHS gene or no functional NHS protein, lead to different diseases. Our data highlight the importance of copy number variation and non-recurrent re-arrangements leading to different severity of disease and describe the potential mechanisms involved. PMID:19414485

Genetic localization and phenotypic expression of X-linked cataract (Xcat) in Mus musculus.

PubMed

Favor, J; Pretsch, W

1990-01-01

Linkage data relative to the markers tabby and glucose-6-phosphate dehydrogenase are presented to locate X-linked cataract (Xcat) in the distal portion of the mouse X-chromosome between jimpy and hypophosphatemia. The human X-linked cataract-dental syndrome, Nance-Horan Syndrome, also maps closely to human hypophosphatemia and would suggest homology between mouse Xcat and human Nance-Horan Syndrome genes. In hemizygous males and homozygous females penetrance is complete with only slight variation in the degree of expression. Phenotypic expression in Xcat heterozygous females ranges from totally clear to totally opaque lenses. The phenotypic expression between the two lenses of a heterozygous individual could also vary between totally clear and totally opaque lenses. However, a correlation in the degree of expression between the eyes of an individual was observed. A variegated pattern of lens opacity was evident in female heterozygotes. Based on these observations, the site of gene action for the Xcat locus is suggested to be endogenous to the lens cells and the precursor cell population of the lens is concluded to be small. The identification of an X-linked cataract locus is an important contribution to the estimate of the number of mutable loci resulting in cataract, an estimate required so that dominant cataract mutagenesis results may be expressed on a per locus basis. The Xcat mutation may be a useful marker for a distal region of the mouse X-chromosome which is relatively sparsely marked and the X-linked cataract mutation may be employed in gene expression and lens development studies.

Human X-Linked genes regionally mapped utilizing X-autosome translocations and somatic cell hybrids.

PubMed Central

Shows, T B; Brown, J A

1975-01-01

Human genes coding for hypoxanthine phosphoribosyltransferase (HPRT, EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase), glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49; D-glucose-6-phosphate:NADP+ 1-oxidoreductase), and phosphoglycerate kinase (PGK, EC 2.7.2.3; ATP:3-phospho-D-glycerate 1-phosphotransferase) have been assigned to specific regions on the long arm of the X chromosome by somatic cell gentic techniques. Gene assignment and linear order were determined by employing human somatic cells possessing an X/9 translocation or an X/22 translocation in man-mouse cell hybridization studies. The X/9 translocation involved the majority of the X long arm translocated to chromosome 9 and the X/22 translocation involved the distal half of the X long arm translocated to 22. In each case these rearrangements appeared to be reciprocal. Concordant segregation of X-linked enzymes and segments of the X chromosome generated by the translocations indicated assignment of the PGK gene to a proximal long arm region (q12-q22) and the HPRT and G6PD genes to the distal half (q22-qter) of the X long arm. Further evidence suggests a gene order on the X long arm of centromere-PGK-HPRT-G6PD. Images PMID:1056018

A novel intronic mutation in the DDP1 gene in a family with X-linked dystonia-deafness syndrome.

PubMed

Ezquerra, Mario; Campdelacreu, Jaume; Muñoz, Esteban; Tolosa, Eduardo; Martí, María J

2005-02-01

X-linked dystonia-deafness syndrome (Mohr-Tranebjaerg syndrome) is a rare neurodegenerative disease characterized by hearing loss and dystonia. So far, 7 mutations in the coding region of the DDP1 gene have been described. They consist of frameshift, nonsense, missense mutations or deletions. To investigate the presence of mutations in the DDP1 gene in a family with dystonia-deafness syndrome. Seven members belonging to 2 generations of a family with 2 affected subjects underwent genetic analysis. Mutational screening in the DDP1 gene was made through DNA direct sequencing. We found an intronic mutation in the DDP1 gene. It consists of an A-to-C substitution in the position -23 in reference to the first nucleotide of exon 2 (IVS1-23A>C). The mutation was present in 2 affected men and their respective unaffected mothers, whereas it was absent in the healthy men from this family and in 90 healthy controls. Intronic mutations in the DDP1 gene can also cause X-linked dystonia-deafness syndrome. In our case, the effect of the mutation could be due to a splicing alteration.

Aggressive tumor growth and clinical evolution in a patient with X-linked acro-gigantism syndrome.

PubMed

Naves, Luciana A; Daly, Adrian F; Dias, Luiz Augusto; Yuan, Bo; Zakir, Juliano Coelho Oliveira; Barra, Gustavo Barcellos; Palmeira, Leonor; Villa, Chiara; Trivellin, Giampaolo; Júnior, Armindo Jreige; Neto, Florêncio Figueiredo Cavalcante; Liu, Pengfei; Pellegata, Natalia S; Stratakis, Constantine A; Lupski, James R; Beckers, Albert

2016-02-01

X-linked acro-gigantism (X-LAG) syndrome is a newly described disease caused by microduplications on chromosome Xq26.3 leading to copy number gain of GPR101. We describe the clinical progress of a sporadic male X-LAG syndrome patient with an Xq26.3 microduplication, highlighting the aggressive natural history of pituitary tumor growth in the absence of treatment. The patient first presented elsewhere aged 5 years 8 months with a history of excessive growth for >2 years. His height was 163 cm, his weight was 36 kg, and he had markedly elevated GH and IGF-1. MRI showed a non-invasive sellar mass measuring 32.5 × 23.9 × 29.1 mm. Treatment was declined and the family was lost to follow-up. At the age of 10 years and 7 months, he presented again with headaches, seizures, and visual disturbance. His height had increased to 197 cm. MRI showed an invasive mass measuring 56.2 × 58.1 × 45.0 mm, with compression of optic chiasma, bilateral cavernous sinus invasion, and hydrocephalus. His thyrotrope, corticotrope, and gonadotrope axes were deficient. Surgery, somatostatin analogs, and cabergoline did not control vertical growth and pegvisomant was added, although vertical growth continues (currently 207 cm at 11 years 7 months of age). X-LAG syndrome is a new genomic disorder in which early-onset pituitary tumorigenesis can lead to marked overgrowth and gigantism. This case illustrates the aggressive nature of tumor evolution and the challenging clinical management in X-LAG syndrome.

Aggressive tumor growth and clinical evolution in a patient with X-linked acro-gigantism syndrome

PubMed Central

Naves, Luciana A.; Daly, Adrian F.; Dias, Luiz Augusto; Yuan, Bo; Zakir, Juliano Coelho Oliveira; Barra, Gustavo Barcellos; Palmeira, Leonor; Villa, Chiara; Trivellin, Giampaolo; Jreige, Armindo; Neto, Florêncio Figueiredo Cavalcante; Liu, Pengfei; Pellegata, Natalia S.; Stratakis, Constantine A.; Lupski, James R.

2017-01-01

X-linked acro-gigantism (X-LAG) syndrome is a newly described disease caused by microduplications on chromosome Xq26.3 leading to copy number gain of GPR101. We describe the clinical progress of a sporadic male X-LAG syndrome patient with an Xq26.3 microduplication, highlighting the aggressive natural history of pituitary tumor growth in the absence of treatment. The patient first presented elsewhere aged 5 years 8 months with a history of excessive growth for >2 years. His height was 163 cm, his weight was 36 kg, and he had markedly elevated GH and IGF-1. MRI showed a non-invasive sellar mass measuring 32.5 × 23.9 × 29.1 mm. Treatment was declined and the family was lost to follow-up. At the age of 10 years and 7 months, he presented again with headaches, seizures, and visual disturbance. His height had increased to 197 cm. MRI showed an invasive mass measuring 56.2 × 58.1 × 45.0 mm, with compression of optic chiasma, bilateral cavernous sinus invasion, and hydrocephalus. His thyrotrope, corticotrope, and gonadotrope axes were deficient. Surgery, somatostatin analogs, and cabergoline did not control vertical growth and pegvisomant was added, although vertical growth continues (currently 207 cm at 11 years 7 months of age). X-LAG syndrome is a new genomic disorder in which early-onset pituitary tumorigenesis can lead to marked overgrowth and gigantism. This case illustrates the aggressive nature of tumor evolution and the challenging clinical management in X-LAG syndrome. PMID:26607152

Auditory, visual, and auditory-visual perceptions of emotions by young children with hearing loss versus children with normal hearing.

PubMed

Most, Tova; Michaelis, Hilit

2012-08-01

This study aimed to investigate the effect of hearing loss (HL) on emotion-perception ability among young children with and without HL. A total of 26 children 4.0-6.6 years of age with prelingual sensory-neural HL ranging from moderate to profound and 14 children with normal hearing (NH) participated. They were asked to identify happiness, anger, sadness, and fear expressed by an actress when uttering the same neutral nonsense sentence. Their auditory, visual, and auditory-visual perceptions of the emotional content were assessed. The accuracy of emotion perception among children with HL was lower than that of the NH children in all 3 conditions: auditory, visual, and auditory-visual. Perception through the combined auditory-visual mode significantly surpassed the auditory or visual modes alone in both groups, indicating that children with HL utilized the auditory information for emotion perception. No significant differences in perception emerged according to degree of HL. In addition, children with profound HL and cochlear implants did not perform differently from children with less severe HL who used hearing aids. The relatively high accuracy of emotion perception by children with HL may be explained by their intensive rehabilitation, which emphasizes suprasegmental and paralinguistic aspects of verbal communication.

A major X-linked locus affects kidney function in mice

PubMed Central

Leduc, Magalie S.; Savage, Holly S.; Stearns, Timothy M.; Cario, Clinton L.; Walsh, Kenneth A.; Paigen, Beverly; Berndt, Annerose

2012-01-01

Chronic kidney disease is a common disease with increasing prevalence in the western population. One common reason for chronic kidney failure is diabetic nephropathy. Diabetic nephropathy and hyperglycemia are characteristics of the mouse inbred strain KK/HlJ, which is predominantly used as a model for metabolic syndrome due to its inherited glucose intolerance and insulin resistance. We used KK/HlJ, an albuminuria-sensitive strain, and C57BL/6J, an albuminuria-resistant strain, to perform a quantitative trait locus (QTL) cross to identify the genetic basis for chronic kidney failure. Albumin-creatinine-ratio (ACR) was measured in 130 F2 male offspring. One significant QTL was identified on chromosome (Chr) X and four suggestive QTLs were found on Chrs 6, 7, 12, and 13. Narrowing of the QTL region was focused on the X-linked QTL and performed by incorporating genotype and expression analyses for genes located in the region. From the 485 genes identified in the X-linked QTL region, a few candidate genes were identified using a combination of bioinformatic evidence based on genomic comparison of the parental strains and known function in urine homeostasis. Finally, this study demonstrates the significance of the X chromosome in the genetic determination of albuminuria. PMID:23011808

Temporary resolution of foveal schisis following vitrectomy with silicon oil tamponade in X-linked retinoschisis with retinal detachment

PubMed Central

Goel, Neha; Ghosh, Basudeb

2015-01-01

X-linked retinoschisis (XLR) is an uncommon bilateral vitreoretinal dystrophy characterized by typical foveoschisis in all patients that may be associated with peripheral retinoschisis. A young male with XLR with retinal detachment in his right eye underwent 23 gauge pars plana vitrectomy with silicone oil tamponade. Postoperatively, best-corrected visual acuity (BCVA) improved to 20/120 with an attached retina. Spectral-domain optical coherence tomography showed macular thinning with the collapse of the schitic cavities with silicone oil in situ. Following silicone oil removal at 6 months follow-up, the retina remained attached with a BCVA of 20/80 however the foveal schitic cavities reappeared. This unusual course has not been described previously. PMID:26669343

Are Deaf Students Visual Learners?

PubMed Central

Marschark, Marc; Morrison, Carolyn; Lukomski, Jennifer; Borgna, Georgianna; Convertino, Carol

2013-01-01

It is frequently assumed that by virtue of their hearing losses, deaf students are visual learners. Deaf individuals have some visual-spatial advantages relative to hearing individuals, but most have been are linked to use of sign language rather than auditory deprivation. How such cognitive differences might affect academic performance has been investigated only rarely. This study examined relations among deaf college students’ language and visual-spatial abilities, mathematics problem solving, and hearing thresholds. Results extended some previous findings and clarified others. Contrary to what might be expected, hearing students exhibited visual-spatial skills equal to or better than deaf students. Scores on a Spatial Relations task were associated with better mathematics problem solving. Relations among the several variables, however, suggested that deaf students are no more likely to be visual learners than hearing students and that their visual-spatial skill may be related more to their hearing than to sign language skills. PMID:23750095

Evolutionary Interactions Between Visual and Chemical Signals: Chemosignals Compensate for the Loss of a Visual Signal in Male Sceloporus Lizards.

PubMed

Pruett, Jake A; Zúñiga-Vega, J Jaime; Campos, Stephanie M; Soini, Helena A; Novotny, Milos V; Vital-García, Cuauhcihuatl; Martins, Emília P; Hews, Diana K

2016-11-01

Animals rely on multimodal signals to obtain information from conspecifics through alternative sensory systems, and the evolutionary loss of a signal in one modality may lead to compensation through increased use of signals in an alternative modality. We investigated associations between chemical signaling and evolutionary loss of abdominal color patches in males of four species (two plain-bellied and two colorful-bellied) of Sceloporus lizards. We conducted field trials to compare behavioral responses of male lizards to swabs with femoral gland (FG) secretions from conspecific males and control swabs (clean paper). We also analyzed the volatile organic compound (VOC) composition of male FG secretions by stir bar extraction and gas chromatography-mass spectrometry (GC-MS) to test the hypothesis that loss of the visual signal is associated with elaboration of the chemical signal. Males of plain-bellied, but not colorful-bellied species exhibited different rates of visual displays when exposed to swabs of conspecific FG secretions relative to control swabs. The VOC composition of male Sceloporus FG secretions was similar across all four species, and no clear association between relative abundances of VOCs and evolutionary loss of abdominal color patches was observed. The emerging pattern is that behavioral responses to conspecific chemical signals are species- and context-specific in male Sceloporus, and compensatory changes in receivers, but not signalers may be involved in mediating increased responsiveness to chemical signals in males of plain-bellied species.

Refined genetic mapping of X-linked Charcot-Marie-Tooth neuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fain, P.R.; Barker, D.F.; Chance, P.F.

1994-02-01

Genetic linkage studies were conducted in four multigenerational families with X-linked Charcot-Marie-Tooth disease (CMTX), using 12 highly polymorphic short-tandem-repeat markers for the pericentromeric region of the X Chromosome. Pairwise linkage analysis with individual markers confirmed tight linkage of CMTX to the pericentromeric region in each family. Multipoint analyses strongly support the order DXS337-CMTX-DXS441-(DXS56, PGK1). 38 refs., 2 figs., 1 tab.

Resolution of spatial and temporal visual attention in infants with fragile X syndrome.

PubMed

Farzin, Faraz; Rivera, Susan M; Whitney, David

2011-11-01

Fragile X syndrome is the most common cause of inherited intellectual impairment and the most common single-gene cause of autism. Individuals with fragile X syndrome present with a neurobehavioural phenotype that includes selective deficits in spatiotemporal visual perception associated with neural processing in frontal-parietal networks of the brain. The goal of the current study was to examine whether reduced resolution of spatial and/or temporal visual attention may underlie perceptual deficits related to fragile X syndrome. Eye tracking was used to psychophysically measure the limits of spatial and temporal attention in infants with fragile X syndrome and age-matched neurotypically developing infants. Results from these experiments revealed that infants with fragile X syndrome experience drastically reduced resolution of temporal attention in a genetic dose-sensitive manner, but have a spatial resolution of attention that is not impaired. Coarse temporal attention could have significant knock-on effects for the development of perceptual, cognitive and motor abilities in individuals with the disorder.

Resolution of spatial and temporal visual attention in infants with fragile X syndrome

PubMed Central

Rivera, Susan M.; Whitney, David

2011-01-01

Fragile X syndrome is the most common cause of inherited intellectual impairment and the most common single-gene cause of autism. Individuals with fragile X syndrome present with a neurobehavioural phenotype that includes selective deficits in spatiotemporal visual perception associated with neural processing in frontal–parietal networks of the brain. The goal of the current study was to examine whether reduced resolution of spatial and/or temporal visual attention may underlie perceptual deficits related to fragile X syndrome. Eye tracking was used to psychophysically measure the limits of spatial and temporal attention in infants with fragile X syndrome and age-matched neurotypically developing infants. Results from these experiments revealed that infants with fragile X syndrome experience drastically reduced resolution of temporal attention in a genetic dose-sensitive manner, but have a spatial resolution of attention that is not impaired. Coarse temporal attention could have significant knock-on effects for the development of perceptual, cognitive and motor abilities in individuals with the disorder. PMID:22075522

Genetic Testing Confirmed the Early Diagnosis of X-Linked Hypophosphatemic Rickets in a 7-Month-Old Infant

PubMed Central

Poon, Kok Siong; Sng, Andrew Anjian; Ho, Cindy Weili; Koay, Evelyn Siew-Chuan

2015-01-01

Loss-of-function mutations in the phosphate regulating gene with homologies to endopeptidases on the X-chromosome (PHEX) have been causally associated with X-linked hypophosphatemic rickets (XLHR). The early diagnosis of XLHR in infants is challenging when it is based solely on clinical features and biochemical findings. We report a 7-month-old boy with a family history of hypophosphatemic rickets., who demonstrated early clinical evidence of rickets, although serial biochemical findings could not definitively confirm rickets. A sequencing assay targeting the PHEX gene was first performed on the mother’s DNA to screen for mutations in the 5′UTR, 22 coding exons, and the exon-intron junctions. Targeted mutation analysis and mRNA studies were subsequently performed on the boys’ DNA to investigate the pathogenicity of the identified mutation. Genetic screening of the PHEX gene revealed a novel mutation, c.1080-2A>C, at the splice acceptor site in intron 9. The detection of an aberrant mRNA transcript with skipped (loss of) exon 10 establishes its pathogenicity and confirms the diagnosis of XLHR in this infant. Genetic testing of the PHEX gene resulted in early diagnosis of XLHR, thus enabling initiation of therapy and prevention of progressive rachitic changes in the infant. PMID:26904698

X-linked Alport syndrome caused by splicing mutations in COL4A5.

PubMed

Nozu, Kandai; Vorechovsky, Igor; Kaito, Hiroshi; Fu, Xue Jun; Nakanishi, Koichi; Hashimura, Yuya; Hashimoto, Fusako; Kamei, Koichi; Ito, Shuichi; Kaku, Yoshitsugu; Imasawa, Toshiyuki; Ushijima, Katsumi; Shimizu, Junya; Makita, Yoshio; Konomoto, Takao; Yoshikawa, Norishige; Iijima, Kazumoto

2014-11-07

X-linked Alport syndrome is caused by mutations in the COL4A5 gene. Although many COL4A5 mutations have been detected, the mutation detection rate has been unsatisfactory. Some men with X-linked Alport syndrome show a relatively mild phenotype, but molecular basis investigations have rarely been conducted to clarify the underlying mechanism. In total, 152 patients with X-linked Alport syndrome who were suspected of having Alport syndrome through clinical and pathologic investigations and referred to the hospital for mutational analysis between January of 2006 and January of 2013 were genetically diagnosed. Among those patients, 22 patients had suspected splice site mutations. Transcripts are routinely examined when suspected splice site mutations for abnormal transcripts are detected; 11 of them showed expected exon skipping, but others showed aberrant splicing patterns. The mutation detection strategy had two steps: (1) genomic DNA analysis using PCR and direct sequencing and (2) mRNA analysis using RT-PCR to detect RNA processing abnormalities. Six splicing consensus site mutations resulting in aberrant splicing patterns, one exonic mutation leading to exon skipping, and four deep intronic mutations producing cryptic splice site activation were identified. Interestingly, one case produced a cryptic splice site with a single nucleotide substitution in the deep intron that led to intronic exonization containing a stop codon; however, the patient showed a clearly milder phenotype for X-linked Alport syndrome in men with a truncating mutation. mRNA extracted from the kidney showed both normal and abnormal transcripts, with the normal transcript resulting in the milder phenotype. This novel mechanism leads to mild clinical characteristics. This report highlights the importance of analyzing transcripts to enhance the mutation detection rate and provides insight into genotype-phenotype correlations. This approach can clarify the cause of atypically mild phenotypes in X-linked

[Detection of large deletions in X linked Alport syndrome using competitive multiplex fluorescence polymerase chain reaction].

PubMed

Wang, F; Zhang, Y Q; Ding, J; Yu, L X

2017-10-18

To evaluate the ability of multiplex competitive fluorescence polymerase chain reaction in detection of large deletion and duplication genotypes of X-linked Alport syndrome. Clinical diagnosis of X-linked Alport syndrome was based on either abnormal staining of type IV collagen α5 chain in the epidermal basement membrane alone or with abnormal staining of type IV collagen α5 chain in the glomerular basement membrane and Bowman's capsule/ultrastructural changes in the glomerular basement membrane typical of Alport syndrome. A total of 20 unrelated Chinese patients (13 males and 7 females) clinically diagnosed as X-linked Alport syndrome were included in the study. Their genotypes were unknown. Control subjects included a male patient with other renal disease and two patients who had large deletions in COL4A5 gene detected by multiplex ligation-dependent probe amplification. Genomic DNA was isolated from peripheral blood leukocytes in all the participants. Multiplex competitive fluorescence polymerase chain reaction was used to coamplify 53 exons of COL4A5 gene and four reference genes in a single reaction. When a deletion removed exon 1 of COL4A5 gene was identified, the same method was used to coamplify the first 4 exons of COL4A5 and COL4A6 genes, a promoter shared by COL4A5 and COL4A6 genes, and three reference genes in a single reaction. Any copy number loss suggested by this method was verified by electrophoresis of corresponding polymerase chain reaction amplified products or DNA sequencing to exclude possible DNA variations in the primer regions. Genotypes of two positive controls identified by multiplex competitive fluorescence polymerase chain reaction were consistent with those detected by multiplex ligation-dependent probe amplification. Deletions were identified in 6 of the 20 patients, including two large deletions removing the 5' part of both COL4A5 and COL4A6 genes with the breakpoint located in the second intron of COL4A6, two large deletions

Visual Pathway Deficit in Female Fragile X Premutation Carriers: A Potential Endophenotype

ERIC Educational Resources Information Center

Keri, Szabolcs; Benedek, Gyorgy

2009-01-01

Previous studies indicated impaired magnocellular (M) and relatively spared parvocellular (P) visual pathway functioning in patients with fragile X syndrome. In this study, we assessed M and P pathways in 22 female fragile X premutation carriers with normal intelligence and in 20 healthy non-carrier controls. Testing procedure included visual…

Visual attention: Linking prefrontal sources to neuronal and behavioral correlates.

PubMed

Clark, Kelsey; Squire, Ryan Fox; Merrikhi, Yaser; Noudoost, Behrad

2015-09-01

Attention is a means of flexibly selecting and enhancing a subset of sensory input based on the current behavioral goals. Numerous signatures of attention have been identified throughout the brain, and now experimenters are seeking to determine which of these signatures are causally related to the behavioral benefits of attention, and the source of these modulations within the brain. Here, we review the neural signatures of attention throughout the brain, their theoretical benefits for visual processing, and their experimental correlations with behavioral performance. We discuss the importance of measuring cue benefits as a way to distinguish between impairments on an attention task, which may instead be visual or motor impairments, and true attentional deficits. We examine evidence for various areas proposed as sources of attentional modulation within the brain, with a focus on the prefrontal cortex. Lastly, we look at studies that aim to link sources of attention to its neuronal signatures elsewhere in the brain. Copyright © 2015. Published by Elsevier Ltd.

A scalable architecture for extracting, aligning, linking, and visualizing multi-Int data

NASA Astrophysics Data System (ADS)

Knoblock, Craig A.; Szekely, Pedro

2015-05-01

An analyst today has a tremendous amount of data available, but each of the various data sources typically exists in their own silos, so an analyst has limited ability to see an integrated view of the data and has little or no access to contextual information that could help in understanding the data. We have developed the Domain-Insight Graph (DIG) system, an innovative architecture for extracting, aligning, linking, and visualizing massive amounts of domain-specific content from unstructured sources. Under the DARPA Memex program we have already successfully applied this architecture to multiple application domains, including the enormous international problem of human trafficking, where we extracted, aligned and linked data from 50 million online Web pages. DIG builds on our Karma data integration toolkit, which makes it easy to rapidly integrate structured data from a variety of sources, including databases, spreadsheets, XML, JSON, and Web services. The ability to integrate Web services allows Karma to pull in live data from the various social media sites, such as Twitter, Instagram, and OpenStreetMaps. DIG then indexes the integrated data and provides an easy to use interface for query, visualization, and analysis.

The Oxysterol, 27-Hydroxycholesterol, Links Cholesterol Metabolism to Bone Homeostasis Through Its Actions on the Estrogen and Liver X Receptors

PubMed Central

Nelson, Erik R.; DuSell, Carolyn D.; Wang, Xiaojuan; Howe, Matthew K.; Evans, Glenda; Michalek, Ryan D.; Umetani, Michihisa; Rathmell, Jeffrey C.; Khosla, Sundeep; Gesty-Palmer, Diane

2011-01-01

Osteoporosis and age-related bone loss are important public health concerns. Therefore, there is a high level of interest in the development of medical interventions and lifestyle changes that reduce the incidence of osteoporosis and age-related bone loss. Decreased bone mineral density is associated with high cholesterol, and patients on statins have increased bone mineral densities, strongly implicating cholesterol as a negative regulator of bone homeostasis. In this study, using both molecular and pharmacological approaches, we have been able to demonstrate that the primary cholesterol metabolite, 27-hydroxycholesterol, through its actions on both estrogen receptors and liver X receptors, decreases osteoblast differentiation and enhances osteoclastogenesis, resulting in increased bone resorbtion in mice. Induction of the short heterodimer partner protein by estrogens in osteoblasts can attenuate the liver X receptor-mediated actions of 27-hydroxycholesterol in bone. These data establish a mechanistic link between cholesterol and bone quality, highlight an unexpected target of estrogens in osteoblasts, and define a signaling axis, the therapeutic exploitation of which is likely to yield novel antiosteoporotic drugs. PMID:21933863

X linked exudative vitreoretinopathy: clinical features and genetic linkage analysis.

PubMed

Fullwood, P; Jones, J; Bundey, S; Dudgeon, J; Fielder, A R; Kilpatrick, M W

1993-03-01

A four generation family in which familial exudative vitreoretinopathy is inherited as an X linked condition is described. Essentially the condition is one of abnormal vascularisation and signs at birth are those of a retinopathy superficially resembling retinopathy of prematurity, retinal folds, or, in advanced cases, enophthalmos or even phthisis. Prognosis depends on the progression of the retinal changes. The family members, including seven affected males and five obligate carrier females, have been types for 20 DNA markers, and linkage analysis suggests a gene locus either at Xq21.3 or at Xp11. As the latter region includes the locus for the gene for Norrie disease, it is possible that this and X linked vitreoretinopathy are allelic. We can further speculate that the differences in severity of the clinical manifestations are dependent only upon the timing of the insult.

A family with X-linked anophthalmia: exclusion of SOX3 as a candidate gene.

PubMed

Slavotinek, Anne; Lee, Stephen S; Hamilton, Steven P

2005-10-01

We report on a four-generation family with X-linked anophthalmia in four affected males and show that this family has LOD scores consistent with linkage to Xq27, the third family reported to be linked to the ANOP1 locus. We sequenced the SOX3 gene at Xq27 as a candidate gene for the X-linked anophthalmia based on the high homology of this gene to SOX2, a gene previously mutated in bilateral anophthlamia. However, no amino acid sequence alterations were identified in SOX3. We have improved the definition of the phenotype in males with anophthalmia linked to the ANOP1 locus, as microcephaly, ocular colobomas, and severe renal malformations have not been described in families linked to ANOP1. (c) 2005 Wiley-Liss, Inc.

Risk factors and visual fatigue of baggage X-ray security screeners: a structural equation modelling analysis.

PubMed

Yu, Rui-Feng; Yang, Lin-Dong; Wu, Xin

2017-05-01

This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue using structural equation modelling approach. Two hundred and five X-ray security screeners participated in a questionnaire survey. The result showed that satisfaction with the VDT's physical features and the work environment conditions were negatively correlated with the intensity of visual fatigue, whereas job stress and job burnout had direct positive influences. The path coefficient between the image quality of VDT and visual fatigue was not significant. The total effects of job burnout, job stress, the VDT's physical features and the work environment conditions on visual fatigue were 0.471, 0.469, -0.268 and -0.251 respectively. These findings indicated that both extrinsic factors relating to VDT and workplace environment and psychological factors including job burnout and job stress should be considered in the workplace design and work organisation of security screening tasks to reduce screeners' visual fatigue. Practitioner Summary: This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue. The findings were of great importance to the workplace design and the work organisation of security screening tasks to reduce screeners' visual fatigue.

Advanced Data Visualization in Astrophysics: The X3D Pathway

NASA Astrophysics Data System (ADS)

Vogt, Frédéric P. A.; Owen, Chris I.; Verdes-Montenegro, Lourdes; Borthakur, Sanchayeeta

2016-02-01

Most modern astrophysical data sets are multi-dimensional; a characteristic that can nowadays generally be conserved and exploited scientifically during the data reduction/simulation and analysis cascades. However, the same multi-dimensional data sets are systematically cropped, sliced, and/or projected to printable two-dimensional diagrams at the publication stage. In this article, we introduce the concept of the “X3D pathway” as a mean of simplifying and easing the access to data visualization and publication via three-dimensional (3D) diagrams. The X3D pathway exploits the facts that (1) the X3D 3D file format lies at the center of a product tree that includes interactive HTML documents, 3D printing, and high-end animations, and (2) all high-impact-factor and peer-reviewed journals in astrophysics are now published (some exclusively) online. We argue that the X3D standard is an ideal vector for sharing multi-dimensional data sets because it provides direct access to a range of different data visualization techniques, is fully open source, and is a well-defined standard from the International Organization for Standardization. Unlike other earlier propositions to publish multi-dimensional data sets via 3D diagrams, the X3D pathway is not tied to specific software (prone to rapid and unexpected evolution), but instead is compatible with a range of open-source software already in use by our community. The interactive HTML branch of the X3D pathway is also actively supported by leading peer-reviewed journals in the field of astrophysics. Finally, this article provides interested readers with a detailed set of practical astrophysical examples designed to act as a stepping stone toward the implementation of the X3D pathway for any other data set.

Linking the trans-Planckian and information loss problems in black hole physics

NASA Astrophysics Data System (ADS)

Liberati, Stefano; Sindoni, Lorenzo; Sonego, Sebastiano

2010-05-01

The trans-Planckian and information loss problems are usually discussed in the literature as separate issues concerning the nature of Hawking radiation. Here we instead argue that they are intimately linked, and can be understood as “two sides of the same coin” once it is accepted that general relativity is an effective field theory.

Combination of secretin and fluvastatin ameliorates the polyuria associated with X-linked nephrogenic diabetes insipidus in mice.

PubMed

Procino, Giuseppe; Milano, Serena; Carmosino, Monica; Barbieri, Claudia; Nicoletti, Maria C; Li, Jian H; Wess, Jürgen; Svelto, Maria

2014-07-01

X-linked nephrogenic diabetes insipidus (X-NDI) is a disease caused by inactivating mutations of the vasopressin (AVP) type 2 receptor (V2R) gene. Loss of V2R function prevents plasma membrane expression of the AQP2 water channel in the kidney collecting duct cells and impairs the kidney concentration ability. In an attempt to develop strategies to bypass V2R signaling in X-NDI, we evaluated the effects of secretin and fluvastatin, either alone or in combination, on kidney function in a mouse model of X-NDI. The secretin receptor was found to be functionally expressed in the kidney collecting duct cells. Based on this, X-NDI mice were infused with secretin for 14 days but urinary parameters were not altered by the infusion. Interestingly, secretin significantly increased AQP2 levels in the collecting duct but the protein primarily accumulated in the cytosol. Since we previously reported that fluvastatin treatment increased AQP2 plasma membrane expression in wild-type mice, secretin-infused X-NDI mice received a single injection of fluvastatin. Interestingly, urine production by X-NDI mice treated with secretin plus fluvastatin was reduced by nearly 90% and the urine osmolality was doubled. Immunostaining showed that secretin increased intracellular stores of AQP2 and the addition of fluvastatin promoted AQP2 trafficking to the plasma membrane. Taken together, these findings open new perspectives for the pharmacological treatment of X-NDI.

Combination of secretin and fluvastatin ameliorates the polyuria associated with X-linked nephrogenic diabetes insipidus in mice

PubMed Central

Procino, Giuseppe; Milano, Serena; Carmosino, Monica; Barbieri, Claudia; Nicoletti, Maria C; H. Li, Jian; Wess, Jürgen; Svelto, Maria

2014-01-01

X-linked nephrogenic diabetes insipidus (X-NDI) is a disease caused by inactivating mutations of the vasopressin (AVP) type 2 receptor (V2R) gene. Loss of V2R function prevents plasma membrane expression of the AQP2 water channel in the kidney collecting duct cells and impairs the kidney concentration ability. In an attempt to develop strategies to bypass V2R signaling in X-NDI, we evaluated the effects of secretin and fluvastatin, either alone or in combination, on kidney function in a mouse model of X-NDI. The secretin receptor was found to be functionally expressed in the kidney collecting duct cells. Based on this, X-NDI mice were infused with secretin for 14 days but urinary parameters were not altered by the infusion. Interestingly, secretin significantly increased AQP2 levels in the collecting duct but the protein primarily accumulated in the cytosol. Since we previously reported that fluvastatin treatment increased AQP2 plasma membrane expression in wild-type mice, secretin-infused X-NDI mice received a single injection of fluvastatin. Interestingly, urine production by X-NDI mice treated with secretin plus fluvastatin was reduced by nearly 90% and the urine osmolality was doubled. Immunostaining showed that secretin increased intracellular stores of AQP2 and the addition of fluvastatin promoted AQP2 trafficking to the plasma membrane. Taken together, these findings open new perspectives for the pharmacological treatment of X-NDI. PMID:24522493

Psychological morbidity and problems of daily living in people with visual loss and diabetes: do they differ from people without diabetes?

PubMed

Robertson, N; Burden, M L; Burden, A C

2006-10-01

To examine psychological adjustment and changes in the activities of daily living in relation to visual loss in diabetes. This was an incident cohort, longitudinal, observational study contrasting the adjustment of individuals with visual loss associated with diabetes and those whose visual loss arose from other conditions; in the year subsequent to registration for blindness and 12 months later, 124 individuals participated in the study (51 with diabetes and 73 without). Participants provided demographic and biomedical information, and completed the Brief COPE, Hospital Anxiety and Depression Scale, SF-36, Instrumental Activities of Daily Living scale and Social Avoidance and Distress Scale via interview. People with diabetes were compared with those without. Both diabetic and non-diabetic groups showed elevated and comparable levels of psychological morbidity, sustained over time. Significant differences in functional adjustment were found at initial interview: people with diabetes having more problems coping but these were no longer present 1 year later. There was a significant and enduring elevation of anxiety and depression in those who were newly registered blind or visually handicapped. Taking these findings into account, psychological assessment should be developed for all those experiencing visual loss.

Visualizing and measuring flow in shale matrix using in situ synchrotron X-ray microtomography

NASA Astrophysics Data System (ADS)

Kohli, A. H.; Kiss, A. M.; Kovscek, A. R.; Bargar, J.

2017-12-01

Natural gas production via hydraulic fracturing of shale has proliferated on a global scale, yet recovery factors remain low because production strategies are not based on the physics of flow in shale reservoirs. In particular, the physical mechanisms and time scales of depletion from the matrix into the simulated fracture network are not well understood, limiting the potential to optimize operations and reduce environmental impacts. Studying matrix flow is challenging because shale is heterogeneous and has porosity from the μm- to nm-scale. Characterizing nm-scale flow paths requires electron microscopy but the limited field of view does not capture the connectivity and heterogeneity observed at the mm-scale. Therefore, pore-scale models must link to larger volumes to simulate flow on the reservoir-scale. Upscaled models must honor the physics of flow, but at present there is a gap between cm-scale experiments and μm-scale simulations based on ex situ image data. To address this gap, we developed a synchrotron X-ray microscope with an in situ cell to simultaneously visualize and measure flow. We perform coupled flow and microtomography experiments on mm-scale samples from the Barnett, Eagle Ford and Marcellus reservoirs. We measure permeability at various pressures via the pulse-decay method to quantify effective stress dependence and the relative contributions of advective and diffusive mechanisms. Images at each pressure step document how microfractures, interparticle pores, and organic matter change with effective stress. Linking changes in the pore network to flow measurements motivates a physical model for depletion. To directly visualize flow, we measure imbibition rates using inert, high atomic number gases and image periodically with monochromatic beam. By imaging above/below X-ray adsorption edges, we magnify the signal of gas saturation in μm-scale porosity and nm-scale, sub-voxel features. Comparing vacuumed and saturated states yields image

HDR syndrome with a novel mutation in GATA3 mimicking a congenital X-linked stapes gusher: a case report.

PubMed

Yang, Aram; Kim, Jinsup; Ki, Chang-Seok; Hong, Sung Hwa; Cho, Sung Yoon; Jin, Dong-Kyu

2017-10-26

Hypoparathyroidism, sensorineural hearing loss, and renal disease (HDR) syndrome, also known as Barakat syndrome, is a rare genetic disorder with high phenotypic heterogeneity caused by haploinsufficiency of the GATA3 gene on chromosome 10p14-p15. For these reasons, the diagnosis of HDR syndrome is challenging and requires a high index of suspicion as well as genetic analysis. A 14-month-old boy, with sensorineural hearing loss in both ears, showed typical radiological features of X-linked stapes gusher on preoperative temporal bone computed tomography (CT) for cochlear implantations. Then after his discharge from hospital, he suffered a hypocalcemic seizure and we discovered a renal cyst during investigation of hypocalcemia. He was finally diagnosed with HDR syndrome by clinical findings, which were confirmed by molecular genetic testing. Direct sequencing of the GATA3 gene showed a heterozygous 2-bp deletion (c.1201_1202delAT), which is predicted to cause a frameshift of the reading frame (p.Met401Valfs*106). To our knowledge, this is the first case of HDR syndrome with a novel de novo variant mimicking a congenital X-linked stapes gusher syndrome. Novel mutations and the diversity of clinical manifestations expand the genotypic and phenotypic spectrum of HDR syndrome. Diagnosis of HDR syndrome is still challenging, but clinicians should consider it in their differential diagnosis for children with a wide range of clinical manifestations including hypocalcemia induced seizures and deafness. We hope that this case will contribute to further understanding and studies of HDR-associated GATA3 mutations.

X-linked Acrogigantism (X-LAG) Syndrome: Clinical Profile and Therapeutic Responses

PubMed Central

Beckers, Albert; Lodish, Maya Beth; Trivellin, Giampaolo; Rostomyan, Liliya; Lee, Misu; Faucz, Fabio R; Yuan, Bo; Choong, Catherine S; Caberg, Jean-Hubert; Verrua, Elisa; Naves, Luciana Ansaneli; Cheetham, Tim D; Young, Jacques; Lysy, Philippe A; Petrossians, Patrick; Cotterill, Andrew; Shah, Nalini Samir; Metzger, Daniel; Castermans, Emilie; Ambrosio, Maria Rosaria; Villa, Chiara; Strebkova, Natalia; Mazerkina, Nadia; Gaillard, Stéphan; Barra, Gustavo Barcelos; Casulari, Luis Augusto; Neggers, Sebastian J.; Salvatori, Roberto; Jaffrain-Rea, Marie-Lise; Zacharin, Margaret; Santamaria, Beatriz Lecumberri; Zacharieva, Sabina; Lim, Ee Mun; Mantovani, Giovanna; Zatelli, Maria Chaira; Collins, Michael T; Bonneville, Jean-François; Quezado, Martha; Chittiboina, Prashant; Oldfield, Edward H.; Bours, Vincent; Liu, Pengfei; De Herder, Wouter; Pellegata, Natalia; Lupski, James R.; Daly, Adrian F.; Stratakis, Constantine A.

2015-01-01

X-linked acro-gigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and a microduplication in chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in 2 families was dominant with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2–3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight SDS score of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF-1 and prolactin, usually due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high somatostatin receptor subtype-2 expression in tumor tissue. Postoperative adjuvant pegvisomant achieved control of IGF-1 all 5 cases in which it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management. PMID:25712922

Visual Field Defects and Retinal Ganglion Cell Losses in Human Glaucoma Patients

PubMed Central

Harwerth, Ronald S.; Quigley, Harry A.

2007-01-01

Objective The depth of visual field defects are correlated with retinal ganglion cell densities in experimental glaucoma. This study was to determine whether a similar structure-function relationship holds for human glaucoma. Methods The study was based on retinal ganglion cell densities and visual thresholds of patients with documented glaucoma (Kerrigan-Baumrind, et al.) The data were analyzed by a model that predicted ganglion cell densities from standard clinical perimetry, which were then compared to histologic cell counts. Results The model, without free parameters, produced accurate and relatively precise quantification of ganglion cell densities associated with visual field defects. For 437 sets of data, the unity correlation for predicted vs. measured cell densities had a coefficient of determination of 0.39. The mean absolute deviation of the predicted vs. measured values was 2.59 dB, the mean and SD of the distribution of residual errors of prediction was -0.26 ± 3.22 dB. Conclusions Visual field defects by standard clinical perimetry are proportional to neural losses caused by glaucoma. Clinical Relevance The evidence for quantitative structure-function relationships provides a scientific basis of interpreting glaucomatous neuropathy from visual thresholds and supports the application of standard perimetry to establish the stage of the disease. PMID:16769839

Counting-loss correction for X-ray spectroscopy using unit impulse pulse shaping.

PubMed

Hong, Xu; Zhou, Jianbin; Ni, Shijun; Ma, Yingjie; Yao, Jianfeng; Zhou, Wei; Liu, Yi; Wang, Min

2018-03-01

High-precision measurement of X-ray spectra is affected by the statistical fluctuation of the X-ray beam under low-counting-rate conditions. It is also limited by counting loss resulting from the dead-time of the system and pile-up pulse effects, especially in a high-counting-rate environment. In this paper a detection system based on a FAST-SDD detector and a new kind of unit impulse pulse-shaping method is presented, for counting-loss correction in X-ray spectroscopy. The unit impulse pulse-shaping method is evolved by inverse deviation of the pulse from a reset-type preamplifier and a C-R shaper. It is applied to obtain the true incoming rate of the system based on a general fast-slow channel processing model. The pulses in the fast channel are shaped to unit impulse pulse shape which possesses small width and no undershoot. The counting rate in the fast channel is corrected by evaluating the dead-time of the fast channel before it is used to correct the counting loss in the slow channel.

Genetic Analysis of a Kindred With X-linked Mental Handicap and Retinitis Pigmentosa

PubMed Central

Aldred, M. A.; Dry, K. L.; Knight-Jones, E. B.; Hardwick, L. J.; Teague, P. W.; Lester, D. H.; Brown, J.; Spowart, G.; Carothers, A. D.; Raeburn, J. A.; Bird, A. C.; Fielder, A. R.; Wright, A. F.

1994-01-01

A kindred is described in which X-linked nonspecific mental handicap segregates together with retinitis pigmentosa. Carrier females are mentally normal but may show signs of the X-linked retinitis pigmentosa carrier state and become symptomatic in their later years. Analysis of polymorphic DNA markers at nine loci on the short arm of the X chromosome shows that no crossing-over occurs between the disease and Xp11 markers DXS255, TIMP, DXS426, MAOA, and DXS228. The 90% confidence limits show that the locus is in the Xp21-q21 region. Haplotype analysis is consistent with the causal gene being located proximal to the Xp21 loci DXS538 and 5'-dystrophin on the short arm of the X chromosome. The posterior probability of linkage to the RP2 region of the X chromosome short arm (Xp11.4-p11.23) is .727, suggesting the possibility of a contiguous-gene-deletion syndrome. No cytogenetic abnormality has been identified. PMID:7977353

Foveomacular schisis in juvenile X-linked retinoschisis: an optical coherence tomography study.

PubMed

Yu, Jia; Ni, Yingqin; Keane, Pearse A; Jiang, Chunhui; Wang, Wenji; Xu, Gezhi

2010-06-01

To explore the structural features of juvenile X-linked retinoschisis using spectral-domain optical coherence tomography (OCT). Retrospective, observational cross-sectional study. Eighteen male patients (34 eyes) who were diagnosed with juvenile X-linked retinoschisis at the Eye & ENT Hospital of Fudan University over an 18-month period were included. Their OCT images, which were obtained using spectral-domain OCT (Cirrus HD-OCT; Carl Zeiss Meditec), were analyzed. The anatomic location of the schisis cavity in juvenile X-linked retinoschisis was characterized by direct inspection of OCT images. On OCT, the schisis cavity was visible at the fovea in all 34 eyes, and it was associated with increased retinal thickness. Schisis was present at the retinal nerve fiber layer in 4 eyes, at the inner nuclear layer in 29 eyes, and at the outer nuclear layer/outer plexiform layer in 22 eyes. In most cases, widespread foveomacular schisis was detected using OCT; however, in 9 eyes (6 patients), the schisis was confined to the fovea. Schisis of the inner nuclear layer and outer nuclear layer/outer plexiform layer almost always involved the foveal center, but retinal nerve fiber layer schisis was seen only in the parafoveal area. Despite conventional wisdom, in patients with X-linked retinoschisis, the schisis cavity can occur in a number of different layers of the neurosensory retina (retinal nerve fiber layer, inner nuclear layer, and outer nuclear layer/outer plexiform layer). In addition, different forms of schisis may affect different locations in the macula (foveal vs parafoveal), and, in most eyes, the schisis involves the entire foveomacular region. Copyright 2010 Elsevier Inc. All rights reserved.

A Novel Mutation in the XLRS1 Gene in a Korean Family with X-linked Retinoschisis

PubMed Central

Jwa, Nam Soo; Kim, Sung Soo; Lee, Sung Chul; Kwon, Oh Woong

2006-01-01

Purpose To report a novel missense mutation in the XLRS1 gene in a Korean family with X-linked retinoschisis. Methods Observation case report of a family with a proband with X-linked retinoschisis underwent complete ophthalmologic examination. Genomic DNA was excluded from the family's blood and all exons of the XLRS1 gene were amplified by polymerase chain reaction and analyzed using a direct sequencing method. Results A novel Leu103Phe missense mutation was identified. Conclusions A novel Leu103Phe mutation is an additional missense mutation which is responsible for the pathogenesis of X-linked retinoschisis. PMID:16768192

Linking crowding, visual span, and reading.

PubMed

He, Yingchen; Legge, Gordon E

2017-09-01

The visual span is hypothesized to be a sensory bottleneck on reading speed with crowding thought to be the major sensory factor limiting the size of the visual span. This proposed linkage between crowding, visual span, and reading speed is challenged by the finding that training to read crowded letters reduced crowding but did not improve reading speed (Chung, 2007). Here, we examined two properties of letter-recognition training that may influence the transfer to improved reading: the spatial arrangement of training stimuli and the presence of flankers. Three groups of nine young adults were trained with different configurations of letter stimuli at 10° in the lower visual field: a flanked-local group (flanked letters localized at one position), a flanked-distributed group (flanked letters distributed across different horizontal locations), and an isolated-distributed group (isolated and distributed letters). We found that distributed training, but not the presence of flankers, appears to be necessary for the training benefit to transfer to increased reading speed. Localized training may have biased attention to one specific, small area in the visual field, thereby failing to improve reading. We conclude that the visual span represents a sensory bottleneck on reading, but there may also be an attentional bottleneck. Reducing the impact of crowding can enlarge the visual span and can potentially facilitate reading, but not when adverse attentional bias is present. Our results clarify the association between crowding, visual span, and reading.

Linking crowding, visual span, and reading

PubMed Central

He, Yingchen; Legge, Gordon E.

2017-01-01

The visual span is hypothesized to be a sensory bottleneck on reading speed with crowding thought to be the major sensory factor limiting the size of the visual span. This proposed linkage between crowding, visual span, and reading speed is challenged by the finding that training to read crowded letters reduced crowding but did not improve reading speed (Chung, 2007). Here, we examined two properties of letter-recognition training that may influence the transfer to improved reading: the spatial arrangement of training stimuli and the presence of flankers. Three groups of nine young adults were trained with different configurations of letter stimuli at 10° in the lower visual field: a flanked-local group (flanked letters localized at one position), a flanked-distributed group (flanked letters distributed across different horizontal locations), and an isolated-distributed group (isolated and distributed letters). We found that distributed training, but not the presence of flankers, appears to be necessary for the training benefit to transfer to increased reading speed. Localized training may have biased attention to one specific, small area in the visual field, thereby failing to improve reading. We conclude that the visual span represents a sensory bottleneck on reading, but there may also be an attentional bottleneck. Reducing the impact of crowding can enlarge the visual span and can potentially facilitate reading, but not when adverse attentional bias is present. Our results clarify the association between crowding, visual span, and reading. PMID:28973564

An overview of hereditary hearing loss.

PubMed

Bayazit, Yildirim A; Yilmaz, Metin

2006-01-01

Understanding the genetic basis of hearing loss is important because almost 50% of profound hearing loss are caused by genetic factors and more than 120 independent genes have been identified. In this review, after a brief explanation of some genetic terms (allele, heterozygosis, homozygosis, polymorphism, genotype and phenotype), classification of genetic hearing loss (syndromic versus nonsyndromic, and recessive dominant, X-linked and mitochondrial) was performed. Some of the most common syndromes (Usher, Pendred, Jervell and Lange-Nielsen, Waardenburg, branchio-oto-renal, Stickler, Treacher Collins and Alport syndromes, biotinidase deficiency and Norrie disease) causing genetic hearing loss were also explained briefly. The genes involved in hearing loss and genetic heterogeneity were presented. Copyright 2006 S. Karger AG, Basel.

X-linked nephrogenic diabetes insipidus mutations in North America and the Hopewell hypothesis.

PubMed Central

Bichet, D G; Arthus, M F; Lonergan, M; Hendy, G N; Paradis, A J; Fujiwara, T M; Morgan, K; Gregory, M C; Rosenthal, W; Didwania, A

1993-01-01

In X-linked nephrogenic diabetes insipidus (NDI) the urine of male patients is not concentrated after the administration of the antidiuretic hormone arginine-vasopressin. This disease is due to mutations in the V2 receptor gene that maps to chromosome region Xq28. In 1969, Bode and Crawford suggested that most NDI patients in North America shared common ancestors of Ulster Scot immigrants who arrived in Halifax in 1761 on the ship Hopewell. A link between this family and a large Utah kindred was also suggested. DNA was obtained from 17 affected male patients from the "Hopewell" kindred and from four additional families from Nova Scotia and New Brunswick who shared the same Xq28 NDI haplotype. The Utah kindred and two families (Q2, Q3) from Quebec were also studied. The "Hopewell" mutation, W71X, is a single base substitution (G-->A) that changes codon 71 from TGG (tryptophan) to TGA (stop). The W71X mutation was found in affected members of the Hopewell and of the four satellite families. The W71X mutation is the cause of X-linked NDI for the largest number of related male patients living in North America. Other families (Utah, Q2 and Q3) that are historically and ethnically unrelated bear other mutations in the V2 receptor gene. Images PMID:8104196

Burosumab Therapy in Children with X-Linked Hypophosphatemia.

PubMed

Carpenter, Thomas O; Whyte, Michael P; Imel, Erik A; Boot, Annemieke M; Högler, Wolfgang; Linglart, Agnès; Padidela, Raja; Van't Hoff, William; Mao, Meng; Chen, Chao-Yin; Skrinar, Alison; Kakkis, Emil; San Martin, Javier; Portale, Anthony A

2018-05-24

X-linked hypophosphatemia is characterized by increased secretion of fibroblast growth factor 23 (FGF-23), which leads to hypophosphatemia and consequently rickets, osteomalacia, and skeletal deformities. We investigated burosumab, a monoclonal antibody that targets FGF-23, in patients with X-linked hypophosphatemia. In an open-label, phase 2 trial, we randomly assigned 52 children with X-linked hypophosphatemia, in a 1:1 ratio, to receive subcutaneous burosumab either every 2 weeks or every 4 weeks; the dose was adjusted to achieve a serum phosphorus level at the low end of the normal range. The primary end point was the change from baseline to weeks 40 and 64 in the Thacher rickets severity total score (ranging from 0 to 10, with higher scores indicating greater disease severity). In addition, the Radiographic Global Impression of Change was used to evaluate rachitic changes from baseline to week 40 and to week 64. Additional end points were changes in pharmacodynamic markers, linear growth, physical ability, and patient-reported outcomes and the incidence of adverse events. The mean Thacher rickets severity total score decreased from 1.9 at baseline to 0.8 at week 40 with every-2-week dosing and from 1.7 at baseline to 1.1 at week 40 with every-4-week dosing (P<0.001 for both comparisons); these improvements persisted at week 64. The mean serum phosphorus level increased after the first dose in both groups, and more than half the patients in both groups had levels within the normal range (3.2 to 6.1 mg per deciliter [1.0 to 2.0 mmol per liter]) by week 6. Stable serum phosphorus levels were maintained through week 64 with every-2-week dosing. Renal tubular phosphate reabsorption increased from baseline in both groups, with an overall mean increase of 0.98 mg per deciliter (0.32 mmol per liter). The mean dose of burosumab at week 40 was 0.98 mg per kilogram of body weight with every-2-week dosing and 1.50 mg per kilogram with every-4-week dosing. Across both

The forensic value of X-linked markers in mixed-male DNA analysis.

PubMed

He, HaiJun; Zha, Lagabaiyila; Cai, JinHong; Huang, Jian

2018-05-04

Autosomal genetic markers and Y chromosome markers have been widely applied in analysis of mixed stains at crime scenes by forensic scientists. However, true genotype combinations are often difficult to distinguish using autosomal markers when similar amounts of DNA are contributed by multiple donors. In addition, specific individuals cannot be determined by Y chromosomal markers because male relatives share the same Y chromosome. X-linked markers, possessing characteristics somewhere intermediate between autosomes and the Y chromosome, are less universally applied in criminal casework. In this paper, X markers are proposed to apply to male mixtures because their true genes can be more easily and accurately recognized than the decision of the genotypes of AS markers. In this study, an actual two-man mixed stain from a forensic case file and simulated male-mixed DNA were examined simultaneously with the X markers and autosomal markers. Finally, the actual mixture was separated successfully by the X markers, although it was unresolved by AS-STRs, and the separation ratio of the simulated mixture was much higher using Chr X tools than with AS methods. We believe X-linked markers provide significant advantages in individual discrimination of male mixtures that should be further applied to forensic work.

Efficacy of sustained topical dorzolamide therapy for cystic macular lesions in patients with X-linked retinoschisis.

PubMed

Genead, Mohamed A; Fishman, Gerald A; Walia, Saloni

2010-02-01

To determine the efficacy of sustained topical therapy with dorzolamide hydrochloride, 2%, on visual acuity and cystic macular lesions in patients with juvenile X-linked retinoschisis (XLRS). Retrospective analysis. University hospital, tertiary care referral center. Twenty-nine eyes of 15 patients with XLRS receiving treatment with the topical dorzolamide formulation for 4 to 41 months were enrolled. Changes in visual acuity, cystic macular lesions, and central foveal zone thickness on optical coherence tomography during follow-up for the duration of treatment. Among the 15 patients with XLRS, 20 eyes (69%) of 11 patients showed a positive response to treatment. Five of the 20 eyes (25%) in 3 of the 11 patients showed an initial response and a subsequent rebound of macular cysts. In 4 eyes (14%) of 3 patients, there was no response to treatment, but the macular cysts did not worsen compared with the baseline level. In 5 additional eyes (17%) of 4 patients, there was no response to treatment, and the macular cysts worsened when compared with the baseline level. Sixteen eyes (55%) of 12 patients had improvement in best-corrected visual acuity by at least 7 letters in at least 1 eye at the most recent follow-up visit. Seventeen eyes (59%) of 10 patients showed a reduction in the central foveal zone thickness in at least 1 eye when compared with the pretreatment level. Patients with XLRS have the potential to experience a beneficial effect from sustained treatment with dorzolamide, 2%.

Role of Visual Speech in Phonological Processing by Children With Hearing Loss

PubMed Central

Jerger, Susan; Tye-Murray, Nancy; Abdi, Hervé

2011-01-01

Purpose This research assessed the influence of visual speech on phonological processing by children with hearing loss (HL). Method Children with HL and children with normal hearing (NH) named pictures while attempting to ignore auditory or audiovisual speech distractors whose onsets relative to the pictures were either congruent, conflicting in place of articulation, or conflicting in voicing—for example, the picture “pizza” coupled with the distractors “peach,” “teacher,” or “beast,” respectively. Speed of picture naming was measured. Results The conflicting conditions slowed naming, and phonological processing by children with HL displayed the age-related shift in sensitivity to visual speech seen in children with NH, although with developmental delay. Younger children with HL exhibited a disproportionately large influence of visual speech and a negligible influence of auditory speech, whereas older children with HL showed a robust influence of auditory speech with no benefit to performance from adding visual speech. The congruent conditions did not speed naming in children with HL, nor did the addition of visual speech influence performance. Unexpectedly, the /∧/-vowel congruent distractors slowed naming in children with HL and decreased articulatory proficiency. Conclusions Results for the conflicting conditions are consistent with the hypothesis that speech representations in children with HL (a) are initially disproportionally structured in terms of visual speech and (b) become better specified with age in terms of auditorily encoded information. PMID:19339701

Variation in the X-Linked EFHC2 Gene Is Associated with Social Cognitive Abilities in Males

PubMed Central

Startin, Carla M.; Fiorentini, Chiara; de Haan, Michelle; Skuse, David H.

2015-01-01

Females outperform males on many social cognitive tasks. X-linked genes may contribute to this sex difference. Males possess one X chromosome, while females possess two X chromosomes. Functional variations in X-linked genes are therefore likely to impact more on males than females. Previous studies of X-monosomic women with Turner syndrome suggest a genetic association with facial fear recognition abilities at Xp11.3, specifically at a single nucleotide polymorphism (SNP rs7055196) within the EFHC2 gene. Based on a strong hypothesis, we investigated an association between variation at SNP rs7055196 and facial fear recognition and theory of mind abilities in males. As predicted, males possessing the G allele had significantly poorer facial fear detection accuracy and theory of mind abilities than males possessing the A allele (with SNP variant accounting for up to 4.6% of variance). Variation in the X-linked EFHC2 gene at SNP rs7055196 is therefore associated with social cognitive abilities in males. PMID:26107779

Manifestations of X-linked congenital stationary night blindness in three daughters of an affected male: Demonstration of homozygosity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bech-Hansen, N.T.; Pearce, W.G.

1993-01-01

X-linked congenital stationary night blindness (CSNB1) is a hereditary retinal disorder in which clinical features in affected males usually include myopia, nystagmus, and impaired visual acuity. Electroretinography demonstrates a marked reduction in b-wave amplitude. In the study of a large Mennonite family with CSNB1, three of five sisters in one sibship were found to have manifestations of CSNB1. All the sons of these three sisters were affected. Each of the two nonmanifesting sisters had at least one unaffected son. Analysis of Xp markers in the region Xp21.1-Xp11.22 showed that the two sisters who were unaffected had inherited the same maternalmore » X chromosome (i.e., M2). Two of the daughters who manifested with CSNB had inherited the other maternal X chromosome (M1). The third manifesting sister inherited a recombinant X chromosome with a crossover between TIMP and DXS255, which suggests that the CSNB1 locus lies proximal to TIMP. One of the affected daughters' sons had inherited the maternal M1 X chromosome, a finding consistent with that chromosome carrying a mutant CSNB gene; the other affected sons inherited the grandfather's X chromosome (i.e., P). Molecular analysis of DNA from three sisters with manifestations of CSNB is consistent with their being homozygous at the CSNB1 locus and with their mother being a carrier of CSNB1. 23 refs., 4 figs., 3 tabs.« less

CORRELATION OF CLINICAL AND STRUCTURAL PROGRESSION WITH VISUAL ACUITY LOSS IN MACULAR TELANGIECTASIA TYPE 2: MacTel Project Report No. 6-The MacTel Research Group.

PubMed

Peto, Tunde; Heeren, Tjebo F C; Clemons, Traci E; Sallo, Ferenc B; Leung, Irene; Chew, Emily Y; Bird, Alan C

2018-01-01

To evaluate progression of macular telangiectasia Type 2 lesions and their correlation with visual acuity. An international multicenter prospective study with annual examinations including best-corrected visual acuity (BCVA), fundus photography, fluorescein angiography, and optical coherence tomography images graded centrally. Mixed models were used to estimate progression rates, and a generalized linear model to compute the relative risk of BCVA loss, loss of ellipsoid zone (EZ) reflectivity, development of pigment plaques, or neovascularization. One thousand and fourteen eyes of 507 participants were followed for 4.2 ± 1.6 years. Best-corrected visual acuity decreased 1.07 ± 0.05 letters (mean ± SE) per year. Of all eyes, 15% lost ≥15 letters after 5 years. Of the eyes without EZ loss, 76% developed a noncentral loss. Of the eyes with noncentral loss, 45% progressed to central EZ loss. The rate of BCVA loss in eyes with noncentral EZ loss at baseline was similar to eyes without EZ loss. The rate of BCVA loss was significantly higher in eyes with central EZ loss at baseline (-1.40 ± 0.14 letters, P < 0.001). Ellipsoid zone loss is frequently found in macular telangiectasia Type 2 and is an important structural component reflecting visual function. Its presence in the fovea significantly correlates with worse visual prognosis.

X-linked infantile spinal muscular atrophy: clinical definition and molecular mapping.

PubMed

Dressman, Devin; Ahearn, Mary Ellen; Yariz, Kemal O; Basterrecha, Hugo; Martínez, Francisco; Palau, Francesc; Barmada, M Michael; Clark, Robin Dawn; Meindl, Alfons; Wirth, Brunhilde; Hoffman, Eric P; Baumbach-Reardon, Lisa

2007-01-01

X-linked infantile spinal-muscular atrophy (XL-SMA) is a rare disorder, which presents with the clinical characteristics of hypotonia, areflexia, and multiple congenital contractures (arthrogryposis) associated with loss of anterior horn cells and death in infancy. We have previously reported a single family with XL-SMA that mapped to Xp11.3-q11.2. Here we report further clinical description of XL-SMA plus an additional seven unrelated (XL-SMA) families from North America and Europe that show linkage data consistent with the same region. We first investigated linkage to the candidate disease gene region using microsatellite repeat markers. We further saturated the candidate disease gene region using polymorphic microsatellite repeat markers and single nucleotide polymorphisms in an effort to narrow the critical region. Two-point and multipoint linkage analysis was performed using the Allegro software package. Linkage analysis of all XL-SMA families displayed linkage consistent with the original XL-SMA region. The addition of new families and new markers has narrowed the disease gene interval for a XL-SMA locus between SNP FLJ22843 near marker DXS 8080 and SNP ARHGEF9 which is near DXS7132 (Xp11.3-Xq11.1).

Flow visualization for investigating stator losses in a multistage axial compressor

NASA Astrophysics Data System (ADS)

Smith, Natalie R.; Key, Nicole L.

2015-05-01

The methodology and implementation of a powder-paint-based flow visualization technique along with the illuminated flow physics are presented in detail for application in a three-stage axial compressor. While flow visualization often accompanies detailed studies, the turbomachinery literature lacks a comprehensive study which both utilizes flow visualization to interrupt the flow field and explains the intricacies of execution. Lessons learned for obtaining high-quality images of surface flow patterns are discussed in this study. Fluorescent paint is used to provide clear, high-contrast pictures of the recirculation regions on shrouded vane rows. An edge-finding image processing procedure is implemented to provide a quantitative measure of vane-to-vane variability in flow separation, which is approximately 7 % of the suction surface length for Stator 1. Results include images of vane suction side corner separations from all three stages at three loading conditions. Additionally, streakline patterns obtained experimentally are compared with those calculated from computational models. Flow physics associated with vane clocking and increased rotor tip clearance and their implications to stator loss are also investigated with this flow visualization technique. With increased rotor tip clearance, the vane surface flow patterns show a shift to larger separations and more radial flow at the tip. Finally, the effects of instrumentation on the flow field are highlighted.

Relationship among visual field, blood flow, and neural structure measurements in glaucoma.

PubMed

Hwang, John C; Konduru, Ranjith; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Varma, Rohit; Sehi, Mitra; Greenfield, David S; Sadda, Srinivas R; Huang, David

2012-05-17

To determine the relationship among visual field, neural structural, and blood flow measurements in glaucoma. Case-control study. Forty-seven eyes of 42 patients with perimetric glaucoma were age-matched with 27 normal eyes of 27 patients. All patients underwent Doppler Fourier-domain optical coherence tomography to measure retinal blood flow and standard glaucoma evaluation with visual field testing and quantitative structural imaging. Linear regression analysis was performed to analyze the relationship among visual field, blood flow, and structure, after all variables were converted to logarithmic decibel scale. Retinal blood flow was reduced in glaucoma eyes compared to normal eyes (P < 0.001). Visual field loss was correlated with both reduced retinal blood flow and structural loss of rim area and retinal nerve fiber layer (RNFL). There was no correlation or paradoxical correlation between blood flow and structure. Multivariate regression analysis revealed that reduced blood flow and structural loss are independent predictors of visual field loss. Each dB decrease in blood flow was associated with at least 1.62 dB loss in mean deviation (P ≤ 0.001), whereas each dB decrease in rim area and RNFL was associated with 1.15 dB and 2.56 dB loss in mean deviation, respectively (P ≤ 0.03). There is a close link between reduced retinal blood flow and visual field loss in glaucoma that is largely independent of structural loss. Further studies are needed to elucidate the causes of the vascular dysfunction and potential avenues for therapeutic intervention. Blood flow measurement may be useful as an independent assessment of glaucoma severity.

Resolution of Spatial and Temporal Visual Attention in Infants with Fragile X Syndrome

ERIC Educational Resources Information Center

Farzin, Faraz; Rivera, Susan M.; Whitney, David

2011-01-01

Fragile X syndrome is the most common cause of inherited intellectual impairment and the most common single-gene cause of autism. Individuals with fragile X syndrome present with a neurobehavioural phenotype that includes selective deficits in spatiotemporal visual perception associated with neural processing in frontal-parietal networks of the…

Application of carrier testing to genetic counseling for X-linked agammaglobulinemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, R.C.; Nachtman, R.G.; Belmont, J.W.

Bruton X-linked agammaglobulinemia (XLA) is a phenotypically recessive genetic disorder of B lymphocyte development. Female carriers of XLA, although asymptomatic, have a characteristic B cell lineage-specific skewing of the pattern of X inactivation. Skewing apparently results from defective growth and maturation of B cell precursors bearing a mutant active X chromosome. In this study, carrier status was tested in 58 women from 22 families referred with a history of agammaglobulinemia. Primary carrier analysis to examine patterns of X inactivation in CD19[sup +] peripheral blood cells (B lymphocytes) was conducted using quantitative PCR at the androgen-receptor locus. Obligate carriers of XLAmore » demonstrated >95% skewing of X inactivation in peripheral blood CD19[sup +] cells but not in CD19[sup [minus

X-Ray and Energy-Loss Spectroscopy | Materials Science | NREL

Science.gov Websites

, we see sharp peaks corresponding to the characteristic X-rays emitted by the atoms of the different ionization edges at high-energy losses, whose onset position is characteristic of the different types of flat c-Si/a-Si interface (see next). A graph with red, green, and blue curves shows different

Detecting Glaucoma With a Portable Brain-Computer Interface for Objective Assessment of Visual Function Loss.

PubMed

Nakanishi, Masaki; Wang, Yu-Te; Jung, Tzyy-Ping; Zao, John K; Chien, Yu-Yi; Diniz-Filho, Alberto; Daga, Fabio B; Lin, Yuan-Pin; Wang, Yijun; Medeiros, Felipe A

2017-06-01

The current assessment of visual field loss in diseases such as glaucoma is affected by the subjectivity of patient responses and the lack of portability of standard perimeters. To describe the development and initial validation of a portable brain-computer interface (BCI) for objectively assessing visual function loss. This case-control study involved 62 eyes of 33 patients with glaucoma and 30 eyes of 17 healthy participants. Glaucoma was diagnosed based on a masked grading of optic disc stereophotographs. All participants underwent testing with a BCI device and standard automated perimetry (SAP) within 3 months. The BCI device integrates wearable, wireless, dry electroencephalogram and electrooculogram systems and a cellphone-based head-mounted display to enable the detection of multifocal steady state visual-evoked potentials associated with visual field stimulation. The performances of global and sectoral multifocal steady state visual-evoked potentials metrics to discriminate glaucomatous from healthy eyes were compared with global and sectoral SAP parameters. The repeatability of the BCI device measurements was assessed by collecting results of repeated testing in 20 eyes of 10 participants with glaucoma for 3 sessions of measurements separated by weekly intervals. Receiver operating characteristic curves summarizing diagnostic accuracy. Intraclass correlation coefficients and coefficients of variation for assessing repeatability. Among the 33 participants with glaucoma, 19 (58%) were white, 12 (36%) were black, and 2 (6%) were Asian, while among the 17 participants with healthy eyes, 9 (53%) were white, 8 (47%) were black, and none were Asian. The receiver operating characteristic curve area for the global BCI multifocal steady state visual-evoked potentials parameter was 0.92 (95% CI, 0.86-0.96), which was larger than for SAP mean deviation (area under the curve, 0.81; 95% CI, 0.72-0.90), SAP mean sensitivity (area under the curve, 0.80; 95% CI, 0

Meiotic drive impacts expression and evolution of x-linked genes in stalk-eyed flies.

PubMed

Reinhardt, Josephine A; Brand, Cara L; Paczolt, Kimberly A; Johns, Philip M; Baker, Richard H; Wilkinson, Gerald S

2014-01-01

Although sex chromosome meiotic drive has been observed in a variety of species for over 50 years, the genes causing drive are only known in a few cases, and none of these cases cause distorted sex-ratios in nature. In stalk-eyed flies (Teleopsis dalmanni), driving X chromosomes are commonly found at frequencies approaching 30% in the wild, but the genetic basis of drive has remained elusive due to reduced recombination between driving and non-driving X chromosomes. Here, we used RNAseq to identify transcripts that are differentially expressed between males carrying either a driving X (XSR) or a standard X chromosome (XST), and found hundreds of these, the majority of which are X-linked. Drive-associated transcripts show increased levels of sequence divergence (dN/dS) compared to a control set, and are predominantly expressed either in testes or in the gonads of both sexes. Finally, we confirmed that XSR and XST are highly divergent by estimating sequence differentiation between the RNAseq pools. We found that X-linked transcripts were often strongly differentiated (whereas most autosomal transcripts were not), supporting the presence of a relatively large region of recombination suppression on XSR presumably caused by one or more inversions. We have identified a group of genes that are good candidates for further study into the causes and consequences of sex-chromosome drive, and demonstrated that meiotic drive has had a profound effect on sequence evolution and gene expression of X-linked genes in this species.

Alport syndrome, mental retardation, midface hypoplasia, and elliptocytosis: a new X linked contiguous gene deletion syndrome?

PubMed Central

Jonsson, J J; Renieri, A; Gallagher, P G; Kashtan, C E; Cherniske, E M; Bruttini, M; Piccini, M; Vitelli, F; Ballabio, A; Pober, B R

1998-01-01

We describe a family with four members, a mother, two sons, and a daughter, who show clinical features consistent with X linked Alport syndrome. The two males presented with additional features including mental retardation, dysmorphic facies with marked midface hypoplasia, and elliptocytosis. The elliptocytosis was not associated with any detectable abnormalities in red cell membrane proteins; red cell membrane stability and rigidity was normal on ektacytometry. Molecular characterisation suggests a submicroscopic X chromosome deletion encompassing the entire COL4A5 gene. We propose that the additional abnormalities found in the affected males of this family are attributable to deletion or disruption of X linked recessive genes adjacent to the COL4A5 gene and that this constellation of findings may represent a new X linked contiguous gene deletion syndrome. Images PMID:9598718

Experience-dependent central vision deficits: Neurobiology and visual acuity.

PubMed

Williams, Kate; Balsor, Justin L; Beshara, Simon; Beston, Brett R; Jones, David G; Murphy, Kathryn M

2015-09-01

Abnormal visual experience during childhood often leads to amblyopia, with strong links to binocular dysfunction that can include poor acuity in both eyes, especially in central vision. In animal models of amblyopia, the non-deprived eye is often considered normal and what limits binocular acuity. This leaves open the question whether monocular deprivation (MD) induces binocular dysfunction similar to what is found in amblyopia. In previous studies of MD cats, we found a loss of excitatory receptors restricted to the central visual field representation in visual cortex (V1), including both eyes' columns. This led us to ask two questions about the effects of MD: how quickly are receptors lost in V1? and is there an impact on binocular acuity? We found that just a few hours of MD caused a rapid loss of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor proteins across all of V1. But after a few days of MD, there was recovery in the visual periphery, leaving a loss of AMPA receptors only in the central region of V1. We reared animals with early MD followed by a long period of binocular vision and found binocular acuity deficits that were greatest in the central visual field. Our results suggest that the greater binocular acuity deficits in the central visual field are driven in part by the long-term loss of AMPA receptors in the central region of V1. Copyright © 2014 Elsevier Ltd. All rights reserved.

Non-syndromic posterior lenticonus a cause of childhood cataract: evidence for X-linked inheritance.

PubMed

Russell-Eggitt, I M

2000-12-01

When an X-linked pedigree of posterior lenticonus with cataract was identified further evidence for X-linked inheritance of this condition was sought. Forty-three cases of posterior lenticonus were identified from a database of 354 children with cataract. Two children with the X-linked syndromes of Lowe and Nance-Horan and 3 children with Fanconi syndrome have been excluded from further analysis. None of the children was deaf. None of the non-syndromic cases had microcornea. There were 38 cases of non-syndromic posterior lenticonus (approximately 11%). There were 15 children from 13 pedigrees and 23 apparently sporadic cases. Of the 106 cases on the database with unilateral cataract 15 had posterior lenticonus (approximately 14%). Eleven of 13 pedigrees were compatible with X-linked inheritance or autosomal dominant inheritance with variable expression. However, in 2 pedigrees there was father to son transmission. Posterior lenticonus is a common cause of unilateral infantile cataract, but is thought to be a rare cause of bilateral cataracts. This study suggests that posterior lenticonus is responsible for a significant proportion of childhood cataracts (approximately 14% of unilateral and approximately 9% of bilateral cases). Posterior lenticonus is generally thought to occur as a sporadic condition. This study demonstrates that there is a family history of early-onset cataract in a significant number of bilateral cases (approximately 58%).

Genotype-phenotype variations in five Spanish families with Norrie disease or X-linked FEVR.

PubMed

Riveiro-Alvarez, Rosa; Trujillo-Tiebas, Maria José; Gimenez-Pardo, Ascension; Garcia-Hoyos, Maria; Cantalapiedra, Diego; Lorda-Sanchez, Isabel; Rodriguez de Alba, Marta; Ramos, Carmen; Ayuso, Carmen

2005-09-02

Norrie disease (OMIM 310600) is a rare X-linked disorder characterized by congenital blindness in males. Approximately 40 to 50% of the cases develop deafness and mental retardation. X-linked familial exudative vitreoretinopathy (XL-FEVR) is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization. Both X-linked disorders are due to mutations in the NDP gene, which encodes a 133 amino acid protein called Norrin, but autosomal recessive (AR) and autosomal dominant (AD) forms of FEVR have also been described. In this study, we report the molecular findings and the related phenotype in five Spanish families affected with Norrie disease or XL-FEVR due to mutations of the NDP gene. The study was conducted in 45 subjects from five Spanish families. These families were clinically diagnosed with Norrie disease or similar conditions. The three exons of the NDP gene were analyzed by automatic DNA sequencing. Haplotype analyses were also performed. Two new nonsense mutations, apart from other mutations previously described in the NDP gene, were found in those patients affected with ND or X-linked FEVR. An important genotype-phenotype variation was found in relation to the different mutations of the NDP gene. In fact, the same mutation may be responsible for different phenotypes. We speculate that there might be other molecular factors that interact in the retina with Norrin, which contribute to the resultant phenotypes.

Selective loss of orientation column maps in visual cortex during brief elevation of intraocular pressure.

PubMed

Chen, Xin; Sun, Chao; Huang, Luoxiu; Shou, Tiande

2003-01-01

To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). IOP was elevated by injecting saline into the anterior chamber of a cat's eye through a syringe needle. The IOP was elevated enough to cause a retinal perfusion pressure (arterial pressure minus IOP) of approximately 30 mm Hg during a brief elevation of IOP. The visual stimulus gratings were varied in spatial frequency, whereas other parameters were kept constant. The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system. These maps were compared before and during short-term elevation of IOP. The response amplitude of the orientation maps in area 17 decreased during a brief elevation of IOP. This decrease was dependent on the retinal perfusion pressure but not on the absolute IOP. The location of the most visible maps was spatial-frequency dependent. The blurring or loss of the pattern of the orientation maps was most severe when high-spatial-frequency gratings were used and appeared most significantly on the posterior part of the exposed cortex while IOP was elevated. However, the basic patterns of the maps remained unchanged. Changes in cortical signal were not due to changes in the optics of the eye with elevation of IOP. A stable normal IOP is essential for maintaining normal visual cortical functions. During a brief and high elevation of IOP, the cortical processing of high-spatial-frequency visual information was diminished because of a selectively functional decline of the retinogeniculocortical X pathway by a mechanism of retinal circulation origin.

Genetic analysis of a kindred with X-linked mental handicap and retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aldred, M.A.; Dry, K.L.; Hardwick, L.J.

1994-11-01

A kindred is described in which X-linked nonspecific mental handicap segregates together with retinitis pigmentosa. Carrier females are mentally normal but may show signs of the X-linked retinitis pigmentosa carrier state and become symptomatic in their later years. Analysis of polymorphic DNA markers at nine loci on the short arm of the X chromosome shows that no crossing-over occurs between the disease and Xp11 markers DXS255, TIMP, DXS426, MAOA, and DXS228. The 90% confidence limits show that the locus is in the Xp21-q21 region. Haplotype analysis is consistent with the causal gene being located proximal to the Xp21 loci DXS538more » and 5{prime}-dystrophin on the short arm of the X chromosome. The posterior probability of linkage to the RP2 region of the X chromosome short arm (Xp11.4-p11.23) is .727, suggesting the possibility of a contiguous-gene-deletion syndrome. No cytogenetic abnormality has been identified. 33 refs., 2 figs., 2 tabs.« less

Isolated cortical visual loss with subtle brain MRI abnormalities in a case of hypoxic-ischemic encephalopathy.

PubMed

Margolin, Edward; Gujar, Sachin K; Trobe, Jonathan D

2007-12-01

A 16-year-old boy who was briefly asystolic and hypotensive after a motor vehicle accident complained of abnormal vision after recovering consciousness. Visual acuity was normal, but visual fields were severely constricted without clear hemianopic features. The ophthalmic examination was otherwise normal. Brain MRI performed 11 days after the accident showed no pertinent abnormalities. At 6 months after the event, brain MRI demonstrated brain volume loss in the primary visual cortex and no other abnormalities. One year later, visual fields remained severely constricted; neurologic examination, including formal neuropsychometric testing, was normal. This case emphasizes the fact that hypoxic-ischemic encephalopathy (HIE) may cause enduring damage limited to primary visual cortex and that the MRI abnormalities may be subtle. These phenomena should be recognized in the management of patients with HIE.

[Prenatal diagnosis of X-linked anhidrotic ectodermal dysplasia with X-chromosome inversion].

PubMed

Shi, Hui-juan; Fang, Qun; Wang, Lian-tang

2005-07-13

To investigate the possibility of prenatal diagnosis of the fetal suspected to be affected by anhidrotic ectodermal dysplasia (EDA) in a family with X-linked EDA so as to provide a basis for prenatal diagnosis and genetic counseling of this disorder. Pedigree analysis and genetic counseling were performed in a family after a proband was diagnosed with EDA. The peripheral blood samples were collected from the proband, a 12-year-old boy, his mother, and his 2 aunts, one being pregnant, to undergo chromosome karyotype analysis. The fetus Puncture of umbilical vein was performed to collect the blood of fetus for chromosome examination. Induced abortion was conducted due to the diagnosis of the fetus with EDA. Autopsy, immunohistochemistry of the skin tissues of face, breast, epigastrium, and thigh, and X-ray photography of the lower jawbone were made. Pericentric inversion occurring at one of the X-chromosome [inv (x) (p22q13)] was found in the proband and his nephew (the fetus), both patients, and his mother and his second aunt (the pregnant woman), both carriers. Autopsy of the fetus showed epidermis dysplasia and deficiency of hair follicle and sebaceous gland. Immunohistochemistry showed that epithelial membrane antigen and cytokeratin were negatively expressed in the fetal skin tissues. Pedigree analysis and genetic counseling for the family members of EDA patients and prenatal and postpartum examination for the fetus help diagnose EDA.

Design and Development of a Linked Open Data-Based Health Information Representation and Visualization System: Potentials and Preliminary Evaluation

PubMed Central

Kauppinen, Tomi; Keßler, Carsten; Fritz, Fleur

2014-01-01

Background Healthcare organizations around the world are challenged by pressures to reduce cost, improve coordination and outcome, and provide more with less. This requires effective planning and evidence-based practice by generating important information from available data. Thus, flexible and user-friendly ways to represent, query, and visualize health data becomes increasingly important. International organizations such as the World Health Organization (WHO) regularly publish vital data on priority health topics that can be utilized for public health policy and health service development. However, the data in most portals is displayed in either Excel or PDF formats, which makes information discovery and reuse difficult. Linked Open Data (LOD)—a new Semantic Web set of best practice of standards to publish and link heterogeneous data—can be applied to the representation and management of public level health data to alleviate such challenges. However, the technologies behind building LOD systems and their effectiveness for health data are yet to be assessed. Objective The objective of this study is to evaluate whether Linked Data technologies are potential options for health information representation, visualization, and retrieval systems development and to identify the available tools and methodologies to build Linked Data-based health information systems. Methods We used the Resource Description Framework (RDF) for data representation, Fuseki triple store for data storage, and Sgvizler for information visualization. Additionally, we integrated SPARQL query interface for interacting with the data. We primarily use the WHO health observatory dataset to test the system. All the data were represented using RDF and interlinked with other related datasets on the Web of Data using Silk—a link discovery framework for Web of Data. A preliminary usability assessment was conducted following the System Usability Scale (SUS) method. Results We developed an LOD

Design and development of a linked open data-based health information representation and visualization system: potentials and preliminary evaluation.

PubMed

Tilahun, Binyam; Kauppinen, Tomi; Keßler, Carsten; Fritz, Fleur

2014-10-25

Healthcare organizations around the world are challenged by pressures to reduce cost, improve coordination and outcome, and provide more with less. This requires effective planning and evidence-based practice by generating important information from available data. Thus, flexible and user-friendly ways to represent, query, and visualize health data becomes increasingly important. International organizations such as the World Health Organization (WHO) regularly publish vital data on priority health topics that can be utilized for public health policy and health service development. However, the data in most portals is displayed in either Excel or PDF formats, which makes information discovery and reuse difficult. Linked Open Data (LOD)-a new Semantic Web set of best practice of standards to publish and link heterogeneous data-can be applied to the representation and management of public level health data to alleviate such challenges. However, the technologies behind building LOD systems and their effectiveness for health data are yet to be assessed. The objective of this study is to evaluate whether Linked Data technologies are potential options for health information representation, visualization, and retrieval systems development and to identify the available tools and methodologies to build Linked Data-based health information systems. We used the Resource Description Framework (RDF) for data representation, Fuseki triple store for data storage, and Sgvizler for information visualization. Additionally, we integrated SPARQL query interface for interacting with the data. We primarily use the WHO health observatory dataset to test the system. All the data were represented using RDF and interlinked with other related datasets on the Web of Data using Silk-a link discovery framework for Web of Data. A preliminary usability assessment was conducted following the System Usability Scale (SUS) method. We developed an LOD-based health information representation, querying

A Complex Genetic Basis to X-Linked Hybrid Male Sterility Between Two Species of House Mice

PubMed Central

Good, Jeffrey M.; Dean, Matthew D.; Nachman, Michael W.

2008-01-01

The X chromosome plays a central role in the evolution of reproductive isolation, but few studies have examined the genetic basis of X-linked incompatibilities during the early stages of speciation. We report the results of a large experiment focused on the reciprocal introgression of the X chromosome between two species of house mice, Mus musculus and M. domesticus. Introgression of the M. musculus X chromosome into a wild-derived M. domesticus genetic background produced male-limited sterility, qualitatively consistent with previous experiments using classic inbred strains to represent M. domesticus. The genetic basis of sterility involved a minimum of four X-linked factors. The phenotypic effects of major sterility QTL were largely additive and resulted in complete sterility when combined. No sterility factors were uncovered on the M. domesticus X chromosome. Overall, these results revealed a complex and asymmetric genetic basis to X-linked hybrid male sterility during the early stages of speciation in mice. Combined with data from previous studies, we identify one relatively narrow interval on the M. musculus X chromosome involved in hybrid male sterility. Only a handful of spermatogenic genes are within this region, including one of the most rapidly evolving genes on the mouse X chromosome. PMID:18689897

A complex genetic basis to X-linked hybrid male sterility between two species of house mice.

PubMed

Good, Jeffrey M; Dean, Matthew D; Nachman, Michael W

2008-08-01

The X chromosome plays a central role in the evolution of reproductive isolation, but few studies have examined the genetic basis of X-linked incompatibilities during the early stages of speciation. We report the results of a large experiment focused on the reciprocal introgression of the X chromosome between two species of house mice, Mus musculus and M. domesticus. Introgression of the M. musculus X chromosome into a wild-derived M. domesticus genetic background produced male-limited sterility, qualitatively consistent with previous experiments using classic inbred strains to represent M. domesticus. The genetic basis of sterility involved a minimum of four X-linked factors. The phenotypic effects of major sterility QTL were largely additive and resulted in complete sterility when combined. No sterility factors were uncovered on the M. domesticus X chromosome. Overall, these results revealed a complex and asymmetric genetic basis to X-linked hybrid male sterility during the early stages of speciation in mice. Combined with data from previous studies, we identify one relatively narrow interval on the M. musculus X chromosome involved in hybrid male sterility. Only a handful of spermatogenic genes are within this region, including one of the most rapidly evolving genes on the mouse X chromosome.

Localisation of the gene for X-linked reticulate pigmentary disorder with systemic manifestations (PDR), previously known as X-linked cutaneous amyloidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gedeon, A.K.; Mulley, J.C.; Kozman, H.

1994-08-01

X-linked reticulate pigmentary disorder (PDR), previously reported as X-linked cutaneous amyloidosis (MIM No. 301220), is characterized by brown pigmentation of the skin which follows the lines of Blaschko in females but appears as reticulate sheets in males. Males may suffer severe gastrointestinal disorders in infancy with failure to thrive and early death. Nowadays symptomatic treatment allows survival and other manifestations may appear such as corneal dystrophy with severe photophobia or chronic respiratory disease. Amyloid deposition in the skin may be no more than an age-dependent secondary manifestation. The PDR gene was localized by linkage analysis to Xp21-p22. The background geneticmore » map is Xpter-DXS996-22.5-DXS207-3.3-DXS999-3.3-DXS365-14.2-DXS989-4.1-3`DMD-3.5-DXS997-1.0-STR44-9.3-DYSI-2.3-DXS1068-11.0-DXS228 with distances between markers given in cM. Recombinants detected with DXS999 distally and DXS228 proximally, define the limits to the localization. Linkage was found with several markers within this interval. Peak lod scores of 3.21 at {theta} = 0.0 were obtained between PDR and DXS989 and between PDR and 5`DYSI within the dystrophin locus. 29 refs., 2 figs., 2 tabs.« less

MicroRNAs and intellectual disability (ID) in Down syndrome, X-linked ID, and Fragile X syndrome

PubMed Central

Siew, Wei-Hong; Tan, Kai-Leng; Babaei, Maryam Abbaspour; Cheah, Pike-See; Ling, King-Hwa

2013-01-01

Intellectual disability (ID) is one of the many features manifested in various genetic syndromes leading to deficits in cognitive function among affected individuals. ID is a feature affected by polygenes and multiple environmental factors. It leads to a broad spectrum of affected clinical and behavioral characteristics among patients. Until now, the causative mechanism of ID is unknown and the progression of the condition is poorly understood. Advancement in technology and research had identified various genetic abnormalities and defects as the potential cause of ID. However, the link between these abnormalities with ID is remained inconclusive and the roles of many newly discovered genetic components such as non-coding RNAs have not been thoroughly investigated. In this review, we aim to consolidate and assimilate the latest development and findings on a class of small non-coding RNAs known as microRNAs (miRNAs) involvement in ID development and progression with special focus on Down syndrome (DS) and X-linked ID (XLID) [including Fragile X syndrome (FXS)]. PMID:23596395

Phenotypic characterization of X-linked retinoschisis: Clinical, electroretinography, and optical coherence tomography variables

PubMed Central

Neriyanuri, Srividya; Dhandayuthapani, Sudha; Arunachalam, Jayamuruga Pandian; Raman, Rajiv

2016-01-01

Aims: To study the phenotypic characteristics of X-linked retinoschisis (XLRS) and report the clinical, electroretinogram (ERG), and optical coherence tomography (OCT) variables in Indian eyes. Design: A retrospective study. Materials and Methods: Medical records of 21 patients with retinoschisis who were genetically confirmed to have RS1 mutation were reviewed. The phenotype characterization included the age of onset, best-corrected visual acuity, refractive error, fundus findings, OCT, and ERG. Statistical Analysis Used: Data from both the eyes were used for analysis. A P < 0.05 was set as statistical significance. Data were not normally distributed (P < 0.05, Shapiro wilk); hence, nonparametric tests were used for statistical analysis. Results: All were males whose mean age of presentation was 9 years. Visual acuity was moderately impaired (median 0.6 logMAR, interquartile range: 0.47, 1) in these eyes with a hyperopic refractive error of median +1.75 Ds (interquartile range: +0.50 Ds, +4.25 Ds). About 54.7% of the eyes had both foveal and peripheral schisis, isolated foveal schisis was seen in 28.5% of the eyes, and schisis with retinal detachment was seen in 16.6% of the eyes. The inner nuclear layer was found to be commonly involved in the schisis, followed by outer nuclear and plexiform layers as evident on OCT. On ERG, a- and b-wave amplitudes were significantly reduced in eyes with foveal and peripheral schisis when compared to the eyes with only foveal schisis (P < 0.05). Conclusions: XLRS has phenotypic heterogeneity as evident on OCT, ERG, and clinical findings. PMID:27609164

Visual field loss and accelerometer-measured physical activity in the United States.

PubMed

van Landingham, Suzanne W; Willis, Jeffrey R; Vitale, Susan; Ramulu, Pradeep Y

2012-12-01

To determine whether visual field (VF) loss is associated with lower levels of accelerometer-defined walking or physical activity in a nationally representative sample of American adults. Cross-sectional study. A total of 2934 adults aged 40 years or older who participated in the examination component of the 2005-2006 National Health and Nutritional Examination Survey. Frequency-doubling technology (FDT) testing was performed in both eyes and used to categorize subjects as having no VF loss, unilateral VF loss, or bilateral VF loss. Accelerometer data were collected over 7 days of normal activity. Steps per day and daily minutes of moderate or vigorous physical activity (MVPA). A total of 1468 participants (50.0%) had complete FDT and accelerometer data. Individuals without VF loss averaged 9751 steps/day and 20.8 minutes/day of MVPA, compared with 8023 steps/day and 14.5 minutes/day for subjects with unilateral VF loss (age-adjusted P = 0.11 and P = 0.51) and 6840 steps/day and 10.1 minutes/day for subjects with bilateral VF loss (age-adjusted P = 0.02 and 0.09, respectively). In multivariable models adjusted for age, sex, race/ethnicity, education, and several comorbid illnesses, individuals with bilateral VF loss took 17% fewer steps per day (P < 0.01) and engaged in 30% less MVPA (P = 0.02) than individuals without VF loss. No significant difference in steps per day or MVPA was observed between individuals with unilateral VF loss and no VF loss (P > 0.05). In addition to VF loss, older age, female sex, arthritis, diabetes, congestive heart failure (CHF), and stroke were significantly associated with fewer daily steps and minutes of MVPA (P < 0.05). Bilateral VF loss is associated with less walking and physical activity in American adults. Patients with bilateral VF loss should be encouraged to engage safely in more physical activity. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2012 American

Effect of acetazolamide on visual function in patients with idiopathic intracranial hypertension and mild visual loss: the idiopathic intracranial hypertension treatment trial.

PubMed

Wall, Michael; McDermott, Michael P; Kieburtz, Karl D; Corbett, James J; Feldon, Steven E; Friedman, Deborah I; Katz, David M; Keltner, John L; Schron, Eleanor B; Kupersmith, Mark J

Acetazolamide is commonly used to treat idiopathic intracranial hypertension (IIH), but there is insufficient information to establish an evidence base for its use. To determine whether acetazolamide is beneficial in improving vision when added to a low-sodium weight reduction diet in patients with IIH and mild visual loss. Multicenter, randomized, double-masked, placebo-controlled study of acetazolamide in 165 participants with IIH and mild visual loss who received a low-sodium weight-reduction diet. Participants were enrolled at 38 academic and private practice sites in North America from March 2010 to November 2012 and followed up for 6 months (last visit in June 2013). All participants met the modified Dandy criteria for IIH and had a perimetric mean deviation (PMD) between -2 dB and -7 dB. The mean age was 29 years and all but 4 participants were women. Low-sodium weight-reduction diet plus the maximally tolerated dosage of acetazolamide (up to 4 g/d) or matching placebo for 6 months. The planned primary outcome variable was the change in PMD from baseline to month 6 in the most affected eye, as measured by Humphrey Field Analyzer. Perimetric mean deviation is a measure of global visual field loss (mean deviation from age-corrected normal values), with a range of 2 to -32 dB; larger negative values indicate greater vision loss. Secondary outcome variables included changes in papilledema grade, quality of life (Visual Function Questionnaire 25 [VFQ-25] and 36-Item Short Form Health Survey), headache disability, and weight at month 6. The mean improvement in PMD was greater with acetazolamide (1.43 dB, from -3.53 dB at baseline to -2.10 dB at month 6; n = 86) than with placebo (0.71 dB, from -3.53 dB to -2.82 dB; n = 79); the difference was 0.71 dB (95% CI, 0 to 1.43 dB; P = .050). Mean improvements in papilledema grade (acetazolamide: -1.31, from 2.76 to 1.45; placebo: -0.61, from 2.76 to 2.15; treatment effect, -0.70; 95% CI, -0.99 to -0.41; P�

Structure/Psychophysical Relationships in X-Linked Retinoschisis.

PubMed

Bennett, Lea D; Wang, Yi-Zhong; Klein, Martin; Pennesi, Mark E; Jayasundera, Thiran; Birch, David G

2016-02-01

To compare structural properties from spectral-domain optical coherence tomography (SDOCT) and psychophysical measures from a subset of patients enrolled in a larger multicenter natural history study of X-linked retinoschisis (XLRS). A subset of males (n = 24) participating in a larger natural history study of XLRS underwent high-resolution SDOCT. Total retina (TR) thickness and outer segment (OS) thickness were measured manually. Shape discrimination hyperacuity (SDH) and contour integration perimetry (CIP) were performed on an iPad with the myVisionTrack application. Sensitivity was measured with fundus-guided perimetry (4-2 threshold testing strategy; 10-2 grid, spot size 3, 68 points). Correlation was determined with Pearson's r correlation. Values are presented as the mean ± SD. Mean macular OS thickness was less in XLRS patients (17.2 ± 8.1 μm) than in controls (37.1 ± 5.7 μm; P < 0.0001) but mean TR thickness was comparable (P = 0.5884). For patients, total sensitivity was lower (13.2 ± 6.6 dB) than for controls (24.2 ± 2.4 dB; P = 0.0008) and had a strong correlation with photoreceptor OS (R(2) = 0.55, P = 0.0001) and a weak correlation with TR thickness (R(2) = 0.22, P = 0.0158). The XLRS subjects had a logMAR best corrected visual acuity (BCVA) of 0.5 ± 0.3 that was associated with OS (R(2) = 0.79, P < 0.0001) but not TR thickness (R(2) = 0.01, P = 0.6166). Shape DH and CIP inner ring correlated with OS (R(2) = 0.33, P = 0.0085 and R(2) = 0.47, P = 0.0001, respectively) but not TR thickness (R(2) = 0.0004, P = 0.93; R(2) = 0.0043, P = 0.75, respectively). When considered from a single visit, OS thickness within the macula is more closely associated with macular function than TR thickness within the macula in patients with XLRS.

Structure/Psychophysical Relationships in X-Linked Retinoschisis

PubMed Central

Bennett, Lea D.; Wang, Yi-Zhong; Klein, Martin; Pennesi, Mark E.; Jayasundera, Thiran; Birch, David G.

2016-01-01

Purpose To compare structural properties from spectral-domain optical coherence tomography (SDOCT) and psychophysical measures from a subset of patients enrolled in a larger multicenter natural history study of X-linked retinoschisis (XLRS). Methods A subset of males (n = 24) participating in a larger natural history study of XLRS underwent high-resolution SDOCT. Total retina (TR) thickness and outer segment (OS) thickness were measured manually. Shape discrimination hyperacuity (SDH) and contour integration perimetry (CIP) were performed on an iPad with the myVisionTrack application. Sensitivity was measured with fundus-guided perimetry (4-2 threshold testing strategy; 10-2 grid, spot size 3, 68 points). Correlation was determined with Pearson's r correlation. Values are presented as the mean ± SD. Results Mean macular OS thickness was less in XLRS patients (17.2 ± 8.1 μm) than in controls (37.1 ± 5.7 μm; P < 0.0001) but mean TR thickness was comparable (P = 0.5884). For patients, total sensitivity was lower (13.2 ± 6.6 dB) than for controls (24.2 ± 2.4 dB; P = 0.0008) and had a strong correlation with photoreceptor OS (R2 = 0.55, P = 0.0001) and a weak correlation with TR thickness (R2 = 0.22, P = 0.0158). The XLRS subjects had a logMAR best corrected visual acuity (BCVA) of 0.5 ± 0.3 that was associated with OS (R2 = 0.79, P < 0.0001) but not TR thickness (R2 = 0.01, P = 0.6166). Shape DH and CIP inner ring correlated with OS (R2 = 0.33, P = 0.0085 and R2 = 0.47, P = 0.0001, respectively) but not TR thickness (R2 = 0.0004, P = 0.93; R2 = 0.0043, P = 0.75, respectively). Conclusions When considered from a single visit, OS thickness within the macula is more closely associated with macular function than TR thickness within the macula in patients with XLRS. PMID:26830370

A Rare Complication After Septoplasty: Visual Loss Due to Right Retinal Artery Spasm.

PubMed

Günay, Celal; Altin, Gökhan; Kersin, Burak; Odabaşi, Mahmut

2018-03-01

Septoplasty is a commonly used procedure for correcting septal cartilage deformities. Hemorrhage, abscesses, scaling, adhesions, and scar tissue are often seen after the operation of the septoplasty, but temporary or permanent visual loss due to local anesthetic use has been reported very rarely in the literature. The authors also aimed to present a female patient with retinal artery spasm in the right eye after septoplasty in this article. A 27-year-old female patient was admitted to the authors' clinic with long-standing nasal obstruction and postnasal drip. There was no feature in her history and also no sign other than nasal septal deviation on physical examination. The patient was informed about the operation and the operation was planned. Emergency eye consultation was requested after the patient said that the right eye of the patient had never seen in the postoperative wake-up hall. Examination by an ophthalmologist; mild exotropia and total loss of vision in the right eye (including loss of light reflex) was detected. The light reaction in the affected eye was negative and indirect reaction was positive. After enlargement of the pupil, fundus examination revealed that the right posterior pole region (inside of the macula and vessel arches) was pale and no central retinal artery pulsation was observed. The patient was diagnosed with central retinal artery occlusion and emergency intervention was performed. The right eye massage, paracentesis, and hyperbaric oxygen therapy returned to the patient's visual function.

Treatment of cystic cavities in X-linked juvenile retinoschisis: The first sequential cross-over treatment regimen with dorzolamide.

PubMed

Coussa, Razek Georges; Kapusta, Michael Alton

2017-12-01

To report the first sequential cross-over treatment with the longest ophthalmic follow-up in a case of X-linked juvenile retinoschisis (XLRS) successfully treated with topical dorzolamide. A healthy 34 year-old man presented with one month history of decreased visual acuity in his left eye. Funduscopy was significant for a blunted and cystoid-like foveal reflex in both eyes. The macular OCT showed cystic foveal changes OU. The patient was diagnosed with XLRS and was observed. On two subsequent follow-ups, a significant decrease in the patient's visual acuity warranted the use of topical dorzolamide for treating the cystic foveal changes, which completely resolved two months post-treatment initiation. Previous reports showed the benefit of dorzolamide in treating foveal cystic cavities in XLRS. To our knowledge, this is the first case of XLRS demonstrating the benefits of topical dorzolamide based on a sequential cross-over treatment regimen. It may also represent a case with the longest ophthalmic follow-up providing, in consequence, long-term understanding of the natural history and complications of this rare disease After ruling out major causes of cystoid macular edema, XLRS patients presenting with worsening of their visual acuities due to larger cystic macular changes may benefit from an alternating ON/OFF regimen of topical dorzolamide, which offers a significant treatment advantage outweighing its well-known side effects. Our study consolidates the importance of "medication vacation" by showing its efficacy in providing anatomical and visual functional improvements in patients with chronic cystic macular changes.

Scanning laser polarimetry, but not optical coherence tomography predicts permanent visual field loss in acute nonarteritic anterior ischemic optic neuropathy.

PubMed

Kupersmith, Mark J; Anderson, Susan; Durbin, Mary; Kardon, Randy

2013-08-15

Scanning laser polarimetry (SLP) reveals abnormal retardance of birefringence in locations of the edematous peripapillary retinal nerve fiber layer (RNFL), which appear thickened by optical coherence tomography (OCT), in nonarteritic anterior ischemic optic neuropathy (NAION). We hypothesize initial sector SLP RNFL abnormalities will correlate with long-term regional visual field loss due to ischemic injury. We prospectively performed automated perimetry, SLP, and high definition OCT (HD-OCT) of the RNFL in 25 eyes with acute NAION. We grouped visual field threshold and RNFL values into Garway-Heath inferior/superior disc sectors and corresponding superior/inferior field regions. We compared sector SLP RNFL thickness with corresponding visual field values at presentation and at >3 months. At presentation, 12 eyes had superior sector SLP reduction, 11 of which had inferior field loss. Six eyes, all with superior field loss, had inferior sector SLP reduction. No eyes had reduced OCT-derived RNFL acutely. Eyes with abnormal field regions had corresponding SLP sectors thinner (P = 0.003) than for sectors with normal field regions. During the acute phase, the SLP-derived sector correlated with presentation (r = 0.59, P = 0.02) and with >3-month after presentation (r = 0.44, P = 0.02) corresponding superior and inferior field thresholds. Abnormal RNFL birefringence occurs in sectors corresponding to regional visual field loss during acute NAION when OCT-derived RNFL shows thickening. Since the visual field deficits show no significant recovery, SLP can be an early marker for axonal injury, which may be used to assess recovery potential at RNFL locations with respect to new treatments for acute NAION.

Understanding the Impact of Return-Current Losses on the X-Ray Emission from Solar Flares

NASA Technical Reports Server (NTRS)

Holman, Gordon D.

2012-01-01

I obtain and examine the implications of one-dimensional analytic solutions for return-current losses on an initially power-law distribution of energetic electrons with a sharp low-energy cutoff in flare plasma with classical (collisional) resistivity. These solutions show, for example, that return-current losses are not sensitive to plasma density, but are sensitive to plasma temperature and the low energy cutoff of the injected nonthermal electron distribution. A characteristic distance from the electron injection site, x(sub rc), is derived. At distances less than x(sub rc) the electron flux density is not reduced by return-current losses, but plasma heating can be substantial in this region, in the upper, coronal part of the flare loop. Before the electrons reach the collisional thick-target region of the flare loop, an injected power-law electron distribution with a low-energy cutoff maintains that structure, but with a flat energy distribution below the cutoff energy, which is now determined by the total potential drop experienced by the electrons. Modifications due to the presence of collisional losses are discussed. I compare these results with earlier analytical results and with more recent numerical simulations. Emslie's 1980 conjecture that there is a maximum integrated X-ray source brightness on the order of 10(exp -15) photons per square centimeter per second per square centimeter is examined. I find that this is not actually a maximum brightness and its value is parameter dependent, but it is nevertheless a valuable benchmark for identifying return-current losses in hard X-ray spectra. I discuss an observational approach to identifying return-current losses in flare data, including identification of a return-current "bump" in X-ray light curves at low photon energies.

Effective weight loss management with endoscopic gastric plication using StomaphyX device: is it achievable?

PubMed

Ong'uti, Sharon K; Ortega, Gezzer; Onwugbufor, Michael T; Ivey, Gabriel D; Fullum, Terrence M; Tran, Daniel D

2013-01-01

Despite the effectiveness of Roux-en-Y gastric bypass (RYGB) in promoting excess weight loss, 40% of the patients regain weight. Endoscopic gastric plication (EGP) using the StomaphyX device can serve as a less-invasive procedure for promoting the loss of regained weight. Our objective was to evaluate the effectiveness of the StomaphyX device in sustaining ongoing weight loss in patients who have regained weight after RYGB at the Division of Minimally Invasive and Bariatric Surgery, Howard University Hospital. We performed a retrospective chart review of patients undergoing EGP using the StomaphyX device from April 2008 to May 2010. The patient demographics and clinical information were assessed. Effective weight loss and the proportion of weight lost after EGP relative to the weight regained after achieving the lowest weight following RYGB was calculated. A total of 27 patients underwent EGP using the StomaphyX device; of these, most were women (n = 25, 93%) and black (n = 14, 52%), followed by white (n = 11, 42%), and Hispanic (n = 1, 4%). The median interval between RYGB and EGP was 6 years, with an interquartile range of 5-8 years. After the EGP procedure, the median effective weight loss was 37% (interquartile range 24-61%). Of the 27 patients, 18 had ≥6 months of follow-up after EGP. Eleven patients had achieved their lowest weight at 1-3 months, 7 at 6 months, and 3 at 12 months. Of the 18 patients, 13 (72%) experienced an increase in weight after achieving their lowest weight after EGP. The use of the StomaphyX device achieved the maximum effective weight loss during the 1-6-month period after EGP. Copyright © 2013 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

[Clinical and molecular study in a child with X-linked hypohidrotic ectodermal dysplasia].

PubMed

Callea, Michele; Yavuz, Izzet; Clarich, Gabriella; Cammarata-Scalisi, Francisco

2015-12-01

Ectodermal dysplasia encompasses more than 200 clinically distinct entities, which affect at least two structures derived from the ectoderm, including the skin, hair, nails, teeth, sweat glands, and sebaceous glands. X-linked hypohidrotic ectodermal dysplasia is the most common type and is caused by mutation of the EDA gene that encodes Ectodysplasin-A. It occurs in less than 1 in 100 000 individuals and is clinically characterized by hypodontia, hypohidrosis, hypotrichosis, and eye dis orders. We present a child evaluated in a multidisciplinary manner with clinical and molecular diagnosis of X-linked hypohidrotic ectodermal dysplasia with type missense mutation c.1133C> T; p.T378M in EDA gene.

X-Linked Retinoschisis in Juveniles: Follow-Up by Optical Coherence Tomography.

PubMed

Hu, Qin-Rui; Huang, Lv-Zhen; Chen, Xiao-Li; Xia, Hui-Ka; Li, Tian-Qi; Li, Xiao-Xin

2017-01-01

Purpose. To explore the structural progression of X-linked retinoschisis (XLRS) in patients by using spectral-domain optical coherence tomography (SD-OCT). Design. Retrospective, observational study. Methods. Patients who were diagnosed with XLRS by genetic testing underwent comprehensive ophthalmological examinations from December 2014 to October 2016. Each eye was measured by SD-OCT using the same clinical protocol. A correlation between best-corrected visual acuity (VA) and SD-OCT measurements was observed. Results. Six patients demonstrated retinoschisis (12 eyes) and typical foveal cyst-like cavities (10 eyes) on SD-OCT images with a mean logMAR VA of 0.48. The median age was 7.5 years at the initial visit. Their foveal retinal thickness (516.9  μ m) and choroid thickness (351.4  μ m) decreased at a rate of 38.1 and 7.5  μ m, respectively, at the 10.5-month follow-up visit; however, there were no significant differences ( P = 0.622 and P = 0.406, resp.). There was no significant correlation between VA, the foveal retinal thickness, and subfoveal choroid thickness. Conclusions. SD-OCT images for XLRS patients during the juvenile period revealed no significant changes in the fundus structure, including the foveal retinal thickness and choroid thickness within one-year follow-up. There was a lack of correlation between VA, foveal retinal thickness, and subfoveal choroid thickness.

X-Linked Retinoschisis in Juveniles: Follow-Up by Optical Coherence Tomography

PubMed Central

Hu, Qin-rui; Huang, Lv-zhen; Xia, Hui-ka; Li, Tian-qi

2017-01-01

Purpose. To explore the structural progression of X-linked retinoschisis (XLRS) in patients by using spectral-domain optical coherence tomography (SD-OCT). Design. Retrospective, observational study. Methods. Patients who were diagnosed with XLRS by genetic testing underwent comprehensive ophthalmological examinations from December 2014 to October 2016. Each eye was measured by SD-OCT using the same clinical protocol. A correlation between best-corrected visual acuity (VA) and SD-OCT measurements was observed. Results. Six patients demonstrated retinoschisis (12 eyes) and typical foveal cyst-like cavities (10 eyes) on SD-OCT images with a mean logMAR VA of 0.48. The median age was 7.5 years at the initial visit. Their foveal retinal thickness (516.9 μm) and choroid thickness (351.4 μm) decreased at a rate of 38.1 and 7.5 μm, respectively, at the 10.5-month follow-up visit; however, there were no significant differences (P = 0.622 and P = 0.406, resp.). There was no significant correlation between VA, the foveal retinal thickness, and subfoveal choroid thickness. Conclusions. SD-OCT images for XLRS patients during the juvenile period revealed no significant changes in the fundus structure, including the foveal retinal thickness and choroid thickness within one-year follow-up. There was a lack of correlation between VA, foveal retinal thickness, and subfoveal choroid thickness. PMID:28286756

A framework for breast cancer visualization using augmented reality x-ray vision technique in mobile technology

NASA Astrophysics Data System (ADS)

Rahman, Hameedur; Arshad, Haslina; Mahmud, Rozi; Mahayuddin, Zainal Rasyid

2017-10-01

Breast Cancer patients who require breast biopsy has increased over the past years. Augmented Reality guided core biopsy of breast has become the method of choice for researchers. However, this cancer visualization has limitations to the extent of superimposing the 3D imaging data only. In this paper, we are introducing an Augmented Reality visualization framework that enables breast cancer biopsy image guidance by using X-Ray vision technique on a mobile display. This framework consists of 4 phases where it initially acquires the image from CT/MRI and process the medical images into 3D slices, secondly it will purify these 3D grayscale slices into 3D breast tumor model using 3D modeling reconstruction technique. Further, in visualization processing this virtual 3D breast tumor model has been enhanced using X-ray vision technique to see through the skin of the phantom and the final composition of it is displayed on handheld device to optimize the accuracy of the visualization in six degree of freedom. The framework is perceived as an improved visualization experience because the Augmented Reality x-ray vision allowed direct understanding of the breast tumor beyond the visible surface and direct guidance towards accurate biopsy targets.

Mapping of the X-linked cataract (Xcat) mutation, the gene implicated in the Nance Horan syndrome, on the mouse X chromosome.

PubMed

Stambolian, D; Favor, J; Silvers, W; Avner, P; Chapman, V; Zhou, E

1994-07-15

The Xcat mutation in the mouse, an X-linked inherited disorder, is characterized by the congenital onset of cataracts. The cataracts have morphologies similar to those of cataracts found in the human Nance Horan (X-linked cataract dental) syndrome, suggesting that Xcat is an animal model for Nance Horan. The Xcat mutation provides an opportunity to investigate, at the molecular level, the pathogenesis of cataract. As a first step to cloning the Xcat gene, we report the localization of the Xcat mutation with respect to known molecular markers on the mouse X chromosome. Back-cross progeny carrying the Xcat mutation were obtained from an interspecific cross. Genomic DNA from each mouse was subjected to Southern and PCR analysis to identify restriction fragment length polymorphisms and simple sequence length polymorphisms, respectively. Our results refine the location of Xcat to a 2-cM region, eliminate several genes from consideration as the Xcat mutation, identify molecular probes tightly linked with Xcat, and suggest candidate genes responsible for the Xcat phenotype.

Assessing interethnic admixture using an X-linked insertion-deletion multiplex.

PubMed

Ribeiro-Rodrigues, Elzemar Martins; dos Santos, Ney Pereira Carneiro; dos Santos, Andrea Kely Campos Ribeiro; Pereira, Rui; Amorim, António; Gusmão, Leonor; Zago, Marco Antonio; dos Santos, Sidney Emanuel Batista

2009-01-01

In this study, a PCR multiplex was optimized, allowing the simultaneous analysis of 13 X-chromosome Insertion/deletion polymorphisms (INDELs). Genetic variation observed in Africans, Europeans, and Native Americans reveals high inter-population variability. The estimated proportions of X-chromosomes in an admixed population from the Brazilian Amazon region show a predominant Amerindian contribution (approximately 41%), followed by European (approximately 32%) and African (approximately 27%) contributions. The proportion of Amerindian contribution based on X-linked data is similar to the expected value based on mtDNA and Y-chromosome information. The accuracy for assessing interethnic admixture, and the high differentiation between African, European, and Native American populations, demonstrates the suitability of this INDEL set to measure ancestry proportions in three-hybrid populations, as it is the case of Latin American populations.

Screening in Primary Care for Diabetic Retinopathy, Maculopathy and Visual Loss in South Africa.

PubMed

Webb, Elizabeth M; Rheeder, Paul; Roux, Polla

2016-01-01

The aim of the study was to determine the prevalence of diabetic retinopathy, maculopathy and visual loss in primary care patients and to identify associated risk factors. We conducted a cluster randomised trial at primary care clinics in the Tshwane district in South Africa. Grades of retinopathy and maculopathy (with fundus camera) and visual acuity (Snellen chart) were assessed and, using mobile screening and teleophthalmology, clinical and biochemical testing was conducted to obtain information about glycaemic control and microvascular complications. The prevalence rates for any retinopathy, preproliferative retinopathy and proliferative retinopathy were 24.9, 19.5 and 5.5%, respectively. The prevalence rates of diabetic maculopathy, observable maculopathy and referable maculopathy were 20.8, 11.8 and 9.0%, respectively. The presence of retinopathy was associated with high body mass index, systolic blood pressure, being on insulin treatment, high HbA1c and the presence of neuropathy. High systolic blood pressure, being on insulin treatment, high HbA1c level and high low-density lipoprotein cholesterol level as well as the presence of albuminuria were significant in predicting any diabetic maculopathy. Laser photocoagulation was given to 8.3% of patients from the mobile unit and 12% of patients were referred to the nearest hospital with an outpatient eye clinic for follow-up treatment of various other eye conditions. Using the WHO categories, the study found that 78.1% of diabetes patients had normal vision, 19.3% were visually impaired and 2.2% were severely impaired or blind. High prevalence rates for diabetic retinopathy, maculopathy and visual loss were found and associations were identified. © 2016 S. Karger AG, Basel.

Visual Attention and Autistic Behavior in Infants with Fragile X Syndrome

ERIC Educational Resources Information Center

Roberts, Jane E.; Hatton, Deborah D.; Long, Anna C. J.; Anello, Vittoria; Colombo, John

2012-01-01

Aberrant attention is a core feature of fragile X syndrome (FXS), however, little is known regarding the developmental trajectory and underlying physiological processes of attention deficits in FXS. Atypical visual attention is an early emerging and robust indicator of autism in idiopathic (non-FXS) autism. Using a biobehavioral approach with gaze…

Impact of high power and angle of incidence on prism corrections for visual field loss.

PubMed

Jung, Jae-Hyun; Peli, Eli

2014-01-17

Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice.

Impact of high power and angle of incidence on prism corrections for visual field loss

PubMed Central

Jung, Jae-Hyun; Peli, Eli

2014-01-01

Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice. PMID:24497649

Gains following perceptual learning are closely linked to the initial visual acuity.

PubMed

Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M; Polat, Uri

2016-04-28

The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, -0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA.

The rapid evolution of X-linked male-biased gene expression and the large-X effect in Drosophila yakuba, D. santomea, and their hybrids.

PubMed

Llopart, Ana

2012-12-01

The X chromosome has a large effect on hybrid dysfunction, particularly on hybrid male sterility. Although the evidence for this so-called large-X effect is clear, its molecular causes are not yet fully understood. One possibility is that, under certain conditions, evolution proceeds faster in X-linked than in autosomal loci (i.e., faster-X effect) due to both natural selection and their hemizygosity in males, an effect that is expected to be greatest in genes with male-biased expression. Here, I study genome-wide variation in transcript abundance between Drosophila yakuba and D. santomea, within these species and in their hybrid males to evaluate both the faster-X and large-X effects at the level of expression. I find that in X-linked male-biased genes (MBGs) expression evolves faster than in their autosomal counterparts, an effect that is accompanied by a unique reduction in expression polymorphism. This suggests that Darwinian selection is driving expression differences between species, likely enhanced by the hemizygosity of the X chromosome in males. Despite the recent split of the two sister species under study, abundant changes in both cis- and trans-regulatory elements underlie expression divergence in the majority of the genes analyzed, with significant differences in allelic ratios of transcript abundance between the two reciprocal F(1) hybrid males. Cis-trans coevolution at molecular level, evolved shortly after populations become isolated, may therefore contribute to explain the breakdown of the regulation of gene expression in hybrid males. Additionally, the X chromosome plays a large role in this hybrid male misexpression, which affects not only MBG but also, to a lesser degree, nonsex-biased genes. Interestingly, hybrid male misexpression is concentrated mostly in autosomal genes, likely facilitated by the rapid evolution of sex-linked trans-acting factors. I suggest that the faster evolution of X-linked MBGs, at both protein and expression levels

Spatial contrast sensitivity vision loss in children with cortical visual impairment.

PubMed

Good, William V; Hou, Chuan; Norcia, Anthony M

2012-11-19

Although cortical visual impairment (CVI) is the leading cause of bilateral vision impairment in children in Western countries, little is known about the effects of CVI on visual function. The aim of this study was to compare visual evoked potential measures of contrast sensitivity and grating acuity in children with CVI with those of age-matched typically developing controls. The swept parameter visual evoked potential (sVEP) was used to measure contrast sensitivity and grating acuity in 34 children with CVI at 5 months to 5 years of age and in 16 age-matched control children. Contrast thresholds and spatial frequency thresholds (grating acuities) were derived by extrapolating the tuning functions to zero amplitude. These thresholds and maximal suprathreshold response amplitudes were compared between groups. Among 34 children with CVI, 30 had measurable but reduced contrast sensitivity with a median threshold of 10.8% (range 5.0%-30.0% Michelson), and 32 had measurable but reduced grating acuity with median threshold 0.49 logMAR (9.8 c/deg, range 5-14 c/deg). These thresholds were significantly reduced, compared with age-matched control children. In addition, response amplitudes over the entire sweep range for both measures were significantly diminished in children with CVI compared with those of control children. Our results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI. The substantial degree of loss in contrast sensitivity suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.

X-linked primary immunodeficiency associated with hemizygous mutations in the moesin (MSN) gene.

PubMed

Lagresle-Peyrou, Chantal; Luce, Sonia; Ouchani, Farid; Soheili, Tayebeh Shabi; Sadek, Hanem; Chouteau, Myriam; Durand, Amandine; Pic, Isabelle; Majewski, Jacek; Brouzes, Chantal; Lambert, Nathalie; Bohineust, Armelle; Verhoeyen, Els; Cosset, François-Loïc; Magerus-Chatinet, Aude; Rieux-Laucat, Frédéric; Gandemer, Virginie; Monnier, Delphine; Heijmans, Catherine; van Gijn, Marielle; Dalm, Virgil A; Mahlaoui, Nizar; Stephan, Jean-Louis; Picard, Capucine; Durandy, Anne; Kracker, Sven; Hivroz, Claire; Jabado, Nada; de Saint Basile, Geneviève; Fischer, Alain; Cavazzana, Marina; André-Schmutz, Isabelle

2016-12-01

We investigated 7 male patients (from 5 different families) presenting with profound lymphopenia, hypogammaglobulinemia, fluctuating monocytopenia and neutropenia, a poor immune response to vaccine antigens, and increased susceptibility to bacterial and varicella zoster virus infections. We sought to characterize the genetic defect involved in a new form of X-linked immunodeficiency. We performed genetic analyses and an exhaustive phenotypic and functional characterization of the lymphocyte compartment. We observed hemizygous mutations in the moesin (MSN) gene (located on the X chromosome and coding for MSN) in all 7 patients. Six of the latter had the same missense mutation, which led to an amino acid substitution (R171W) in the MSN four-point-one, ezrin, radixin, moesin domain. The seventh patient had a nonsense mutation leading to a premature stop codon mutation (R533X). The naive T-cell counts were particularly low for age, and most CD8 + T cells expressed the senescence marker CD57. This phenotype was associated with impaired T-cell proliferation, which was rescued by expression of wild-type MSN. MSN-deficient T cells also displayed poor chemokine receptor expression, increased adhesion molecule expression, and altered migration and adhesion capacities. Our observations establish a causal link between an ezrin-radixin-moesin protein mutation and a primary immunodeficiency that could be referred to as X-linked moesin-associated immunodeficiency. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Novel XLRS1 gene mutations cause X-linked juvenile retinoschisis in Chinese families.

PubMed

Ma, Xiang; Li, Xiaoxin; Wang, Lihua

2008-01-01

To investigate various XLRS1 (RS1) gene mutations in Chinese families with X-linked juvenile retinoschisis (XLRS or RS). Genomic DNA was isolated from leukocytes of 29 male patients with X-linked juvenile retinoschisis, 38 female carriers, and 100 normal controls. All 6 exons of the RS1 gene were amplified by polymerase chain reaction, and the RS1 gene mutations were determined by direct sequencing. Eleven different RS1 mutations in 12 families were identified in the 29 male patients. The mutations comprised eight missense, two frameshift, and one splice donor site mutation. Four of these mutations, one frameshift mutation (26 del T) in exon 1, one frameshift mutation (488 del G) in exon 5, Asp145His and Arg156Gly in exon 5, have not been previously described. One novel non-disease-related polymorphism, 576C to T (Pro192Pro) in exon 6, was also found. Six recurrent mutations, Ser73Pro and Arg102Gln mutations in exon 4 and Arg200Cys, Arg209His, Arg213Gln, and Cys223Arg mutations in exon 6, were also identified in this study. RS1 gene mutations caused X-linked juvenile retinoschisis in these Chinese families.

Loss of Xist RNA from the inactive X during B cell development is restored in a dynamic YY1-dependent two-step process in activated B cells

PubMed Central

Syrett, Camille M.; Sindhava, Vishal; Hodawadekar, Suchita; Myles, Arpita; Liang, Guanxiang; Zhang, Yue; Nandi, Satabdi; Cancro, Michael; Atchison, Michael

2017-01-01

X-chromosome inactivation (XCI) in female lymphocytes is uniquely regulated, as the inactive X (Xi) chromosome lacks localized Xist RNA and heterochromatin modifications. Epigenetic profiling reveals that Xist RNA is lost from the Xi at the pro-B cell stage and that additional heterochromatic modifications are gradually lost during B cell development. Activation of mature B cells restores Xist RNA and heterochromatin to the Xi in a dynamic two-step process that differs in timing and pattern, depending on the method of B cell stimulation. Finally, we find that DNA binding domain of YY1 is necessary for XCI in activated B cells, as ex-vivo YY1 deletion results in loss of Xi heterochromatin marks and up-regulation of X-linked genes. Ectopic expression of the YY1 zinc finger domain is sufficient to restore Xist RNA localization during B cell activation. Together, our results indicate that Xist RNA localization is critical for maintaining XCI in female lymphocytes, and that chromatin changes on the Xi during B cell development and the dynamic nature of YY1-dependent XCI maintenance in mature B cells predisposes X-linked immunity genes to reactivation. PMID:28991910

Minimalist coupled evolution model for stellar X-ray activity, rotation, mass loss, and magnetic field

NASA Astrophysics Data System (ADS)

Blackman, Eric G.; Owen, James E.

2016-05-01

Late-type main-sequence stars exhibit an X-ray to bolometric flux ratio that depends on {tilde{R}o}, the ratio of rotation period to convective turnover time, as {tilde{R}o}^{-ζ } with 2 ≤ ζ ≤ 3 for {tilde{R}o} > 0.13, but saturates with |ζ| < 0.2 for {tilde{R}o} < 0.13. Saturated stars are younger than unsaturated stars and show a broader spread of rotation rates and X-ray activity. The unsaturated stars have magnetic fields and rotation speeds that scale roughly with the square root of their age, though possibly flattening for stars older than the Sun. The connection between faster rotators, stronger fields, and higher activity has been established observationally, but a theory for the unified time-evolution of X-ray luminosity, rotation, magnetic field and mass loss that captures the above trends has been lacking. Here we derive a minimalist holistic framework for the time evolution of these quantities built from combining a Parker wind with new ingredients: (1) explicit sourcing of both the thermal energy launching the wind and the X-ray luminosity via dynamo produced magnetic fields; (2) explicit coupling of X-ray activity and mass-loss saturation to dynamo saturation (via magnetic helicity build-up and convection eddy shredding); (3) use of coronal equilibrium to determine how magnetic energy is divided into wind and X-ray contributions. For solar-type stars younger than the Sun, we infer conduction to be a subdominant power loss compared to X-rays and wind. For older stars, conduction is more important, possibly quenching the wind and reducing angular momentum loss. We focus on the time evolution for stars younger than the Sun, highlighting what is possible for further generalizations. Overall, the approach shows promise towards a unified explanation of all of the aforementioned observational trends.

Adjustment to acquired vision loss in adults presenting for visual disability certification.

PubMed

Nakade, Aditya; Rohatgi, Jolly; Bhatia, Manjeet S; Dhaliwal, Upreet

2017-03-01

Rehabilitation of the visually disabled depends on how they adjust to loss; understanding contributing factors may help in effective rehabilitation. The aim of this study is to assess adjustment to acquired vision loss in adults. This observational study, conducted in the Department of Ophthalmology at a tertiary-level teaching hospital, included thirty persons (25-65 years) with <6/60 in the better eye, and vision loss since ≥6-months. Age, gender, rural/urban residence, education, current occupation, binocular distance vision, adjustment (Acceptance and Self-Worth Adjustment Scale), depression (Center for Epidemiologic Studies-Depression Scale), social support (Duke Social Support and Stress Scale), and personality (10-item Personality Inventory scale) was recorded. To determine their effect on adjustment, Student's t-test was used for categorical variables, Pearson's correlation for age, and Spearman's correlation for depression, personality trait and social support and stress. Of 30 persons recruited, 24 were men (80%); 24 lived in urban areas (80%); 9 were employed (30%); and 14 (46.6%) had studied < Class 3. Adjustment was low (range: 33%-60%; mean: 43.6 ± 5.73). Reported support was low (median: 27.2; interquartile range [IQR]: 18.1-36.3); reported stress was low (median: 0.09; IQR: 0-18.1). Predominant personality traits (max score 14) were "Agreeableness" (average 12.0 ± 1.68) and "Conscientiousness" (average 11.3 ± 2.12). Emotional stability (average 9.2 ± 2.53) was less prominent. Depression score ranged from 17 to 50 (average 31.6 ± 6.01). The factors studied did not influence adjustment. Although adjustment did not vary with factors studied, all patients were depressed. Since perceived support and emotional stability was low, attention could be directed to support networks. Training patients in handling emotions, and training family members to respond to emotional needs of persons with visual disability, might contribute to reducing stress and

Optimizing rehabilitation for adults with visual impairment: attention to life goals and their links to well-being.

PubMed

Boerner, Kathrin; Cimarolli, Verena R

2005-10-01

To examine the importance of different life goals among working-age adults with vision impairment, the extent to which vision impairment interfered with goals, and how rehabilitation addressed these life goals. Cross-sectional descriptive study. Vision rehabilitation agency. Working-age adults with visual impairment. Telephone interviews using structured and open-ended assessments of life goal importance, goal interference due to vision loss, the role of goals in rehabilitation, and indicators of well-being. Eighty-six people participated. The life domains most frequently rated as extremely important were finances (60), residential and domestic arrangements (55), family (51), partner (48), and personal care (48). The extent to which vision loss interferes with these life goals was extreme for finances (46), residential and domestic arrangements (36), partner (27), family (25), and personal care (14). A life goal was addressed in rehabilitation: residential/domestic arrangements (41), work (39), finances (31), leisure/hobbies (28), personal care (24), family (17), partner (16), friends (10), and religion/life philosophy (8). Reports of a life goal being addressed in ineffective ways emerged for functional life goals, but not for relationship and religion/life philosophy goals. Goal interference was significantly correlated with well-being indicators across life domains. In contrast only partner and family relationship importance were significantly linked with well-being indicators. Relationship-related goals were a top priority for this study population, but functional compared to relationship goals were more commonly addressed in vision rehabilitation services.

Micro X-Ray Computed Tomography Mass Loss Assessment of Different UHMWPE: A Hip Joint Simulator Study on Standard vs. Cross-Linked Polyethylene

PubMed Central

Zanini, Filippo; Carmignato, Simone

2017-01-01

More than 60.000 hip arthroplasty are performed every year in Italy. Although Ultra-High-Molecular-Weight-Polyethylene remains the most used material as acetabular cup, wear of this material induces over time in vivo a foreign-body response and consequently osteolysis, pain, and the need of implant revision. Furthermore, oxidative wear of the polyethylene provoke several and severe failures. To solve these problems, highly cross-linked polyethylene and Vitamin-E-stabilized polyethylene were introduced in the last years. In in vitro experiments, various efforts have been made to compare the wear behavior of standard PE and vitamin-E infused liners. In this study we compared the in vitro wear behavior of two different configurations of cross-linked polyethylene (with and without the add of Vitamin E) vs. the standard polyethylene acetabular cups. The aim of the present study was to validate a micro X-ray computed tomography technique to assess the wear of different commercially available, polyethylene’s acetabular cups after wear simulation; in particular, the gravimetric method was used to provide reference wear values. The agreement between the two methods is documented in this paper. PMID:28107468

The Mars Observer Ka-band link experiment

NASA Technical Reports Server (NTRS)

Rebold, T. A.; Kwok, A.; Wood, G. E.; Butman, S.

1994-01-01

The Ka-Band Link Experiment was the first demonstration of a deep-space communications link in the 32- to 35-GHz band (Ka-band). It was carried out using the Mars Observer spacecraft while the spacecraft was in the cruise phase of its mission and using a 34-meter beam-waveguide research and development antenna at the Goldstone complex of the DSN. The DSN has been investigating the performance benefits of a shift from X-band (8.4 GHz) to Ka-band (32 GHz) for deep-space communications. The fourfold increase in frequency is expected to offer a factor of 3 to 10 improvement (5 to 10 dB) in signal strength for a given spacecraft transmitter power and antenna size. Until recently, the expected benefits were based on performance studies, with an eye to implementing such a link, but theory was transformed to reality when a 33.7-GHz Ka-band signal was received from the spacecraft by DSS 13. This article describes the design and implementation of the Ka-Band Link Experiment from the spacecraft to the DSS-13 system, as well as results from the Ka-band telemetry demonstration, ranging demonstration, and long-term tracking experiment. Finally, a preliminary analysis of comparative X- and Ka-band tracking results is included. These results show a 4- to 7-dB advantage for Ka-band using the system at DSS 13, assuming such obstacles as antenna pointing loss and power conversion loss are overcome.

R213W mutation in the retinoschisis 1 gene causes X-linked juvenile retinoschisis in a large Chinese family.

PubMed

Xu, Jun; Gu, Hong; Ma, Kai; Liu, Xipu; Snellingen, Torkel; Sun, Erdan; Wang, Ningli; Liu, Ningpu

2010-08-12

We identified a large Chinese family with X-linked juvenile retinoschisis. The purpose of this study was to report the clinical findings of the family and to identify the genetic mutation by screening the retinoschisis 1 (RS1) gene. Family history was collected and all family members underwent routine ophthalmic examination. Venous blood was collected from family members and genomic DNA was extracted. The exons of RS1 were screened by PCR followed by direct sequencing and/or restriction enzyme digestion. The pedigree of interest was a four-generation family with 52 family members, including seven affected individuals. The proband was a 5-year-old boy showing highly elevated bullous retinoschisis with moderate vitreous hemorrhage in both eyes. Vitrectomy was performed in the left eye of the proband. Five affected males showed large peripheral retinoschisis in both eyes, either involving the macula or combined with foveal stellate cystic change. One of the affected family members showed only a foveal stellate cystic change in both eyes without periphery retinoschisis. Visual acuity of affected individuals ranged from hand motion to 0.4. The R213W mutation in exon 6 of RS1 was identified in all affected individuals, predicting an amino acid substitution of arginine to tryptophan at codon 213. Our data show that the R213W mutation in RS1 causes various severities of retinoschisis in a large Chinese family, providing further evidence for X-linked juvenile retinoschisis phenotypic variability.

R213W mutation in the retinoschisis 1 gene causes X-linked juvenile retinoschisis in a large Chinese family

PubMed Central

Xu, Jun; Gu, Hong; Ma, Kai; Liu, Xipu; Snellingen, Torkel; Sun, Erdan; Wang, Ningli

2010-01-01

Purpose We identified a large Chinese family with X-linked juvenile retinoschisis. The purpose of this study was to report the clinical findings of the family and to identify the genetic mutation by screening the retinoschisis 1 (RS1) gene. Methods Family history was collected and all family members underwent routine ophthalmic examination. Venous blood was collected from family members and genomic DNA was extracted. The exons of RS1 were screened by PCR followed by direct sequencing and/or restriction enzyme digestion. Results The pedigree of interest was a four-generation family with 52 family members, including seven affected individuals. The proband was a 5-year-old boy showing highly elevated bullous retinoschisis with moderate vitreous hemorrhage in both eyes. Vitrectomy was performed in the left eye of the proband. Five affected males showed large peripheral retinoschisis in both eyes, either involving the macula or combined with foveal stellate cystic change. One of the affected family members showed only a foveal stellate cystic change in both eyes without periphery retinoschisis. Visual acuity of affected individuals ranged from hand motion to 0.4. The R213W mutation in exon 6 of RS1 was identified in all affected individuals, predicting an amino acid substitution of arginine to tryptophan at codon 213. Conclusions Our data show that the R213W mutation in RS1 causes various severities of retinoschisis in a large Chinese family, providing further evidence for X-linked juvenile retinoschisis phenotypic variability. PMID:20806044

Assessment of Human Visual Performance with a Swept Evoked Potential Technique

DTIC Science & Technology

1984-07-01

obtained in naive patients. Retinitis pigmentosa patients with < 20/50 vision have shown contrast sensitivity losses at the higher spatial frequencies...X and Y visual subsystems The new visual duplicity. Th« observation that cat retinal ganglion cells can be divided into those which sum luminous...bias in retinal ganglion cells (cat: Levick & Thibos, 1980; monkey: DeMonasterio, 1978). The bias is weak. In cat, when the stimulus orientation was

Driving with Binocular Visual Field Loss? A Study on a Supervised On-Road Parcours with Simultaneous Eye and Head Tracking

PubMed Central

Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the

LOSS OF L-FABP, SCP-2/SCP-X, OR BOTH INDUCES HEPATIC LIPID ACCUMULATION IN FEMALE MICE

PubMed Central

Martin, Gregory G.; Atshaves, Barbara P.; Landrock, Kerstin K.; Landrock, Danilo; Schroeder, Friedhelm; Kier, Ann B.

2015-01-01

Although roles for both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed in hepatic lipid accumulation, individually ablating these genes has been complicated by concomitant alterations in the other gene product(s). For example, ablating SCP2/SCP-x induces upregulation of L-FABP in female mice. Therefore, the impact of ablating SCP-2/SCP-x (DKO) or L-FABP (LKO) individually or both together (TKO) was examined in female mice. Loss of SCP-2/SCP-x (DKO, TKO) more so than loss of L-FABP alone (LKO) increased hepatic total lipid and total cholesterol content, especially cholesteryl ester. Hepatic accumulation of nonesterified long chain fatty acids (LCFA) and phospholipids occurred only in DKO and TKO mice. Loss of SCP-2/SCP-x (DKO, TKO) increased serum total lipid primarily by increasing triglycerides. Altered hepatic level of proteins involved in cholesterol uptake, efflux, and/or secretion was observed, but did not compensate for the loss of L-FABP, SCP-2/SCP-x or both. However, synergistic responses were not seen with the combinatorial knock out animals—suggesting that inhibiting SCP-2/SCP-x is more correlative with hepatic dysfunction than L-FABP. The DKO- and TKO-induced hepatic accumulation of cholesterol and long chain fatty acids shared significant phenotypic similarities with non-alcoholic fatty liver disease (NAFLD). PMID:26116377

Seeing meaning in action: a bidirectional link between visual perspective and action identification level.

PubMed

Libby, Lisa K; Shaeffer, Eric M; Eibach, Richard P

2009-11-01

Actions do not have inherent meaning but rather can be interpreted in many ways. The interpretation a person adopts has important effects on a range of higher order cognitive processes. One dimension on which interpretations can vary is the extent to which actions are identified abstractly--in relation to broader goals, personal characteristics, or consequences--versus concretely, in terms of component processes. The present research investigated how visual perspective (own 1st-person vs. observer's 3rd-person) in action imagery is related to action identification level. A series of experiments measured and manipulated visual perspective in mental and photographic images to test the connection with action identification level. Results revealed a bidirectional causal relationship linking 3rd-person images and abstract action identifications. These findings highlight the functional role of visual imagery and have implications for understanding how perspective is involved in action perception at the social, cognitive, and neural levels. Copyright 2009 APA

Interference between extrinsic and intrinsic losses in x-ray absorption fine structure

NASA Astrophysics Data System (ADS)

Campbell, L.; Hedin, L.; Rehr, J. J.; Bardyszewski, W.

2002-02-01

The interference between extrinsic and intrinsic losses in x-ray absorption fine structure (XAFS) is treated within a Green's-function formalism, without explicit reference to final states. The approach makes use of a quasiboson representation of excitations and perturbation theory in the interaction potential between electrons and quasibosons. These losses lead to an asymmetric broadening of the main quasiparticle peak plus an energy-dependent satellite in the spectral function. The x-ray absorption spectra (XAS) is then given by a convolution of an effective spectral function over a one-electron cross section. It is shown that extrinsic and intrinsic losses tend to cancel near excitation thresholds, and correspondingly, the strength in the main peak increases. At high energies, the theory crosses over to the sudden approximation. These results thus explain the observed weakness of multielectron excitations in XAS. The approach is applied to estimate the many-body corrections to XAFS, beyond the usual mean-free path, using a phasor summation over the spectral function. The asymmetry of the spectral function gives rise to an additional many-body phase shift in the XAFS formula.

Defining the cause of skewed X-chromosome inactivation in X-linked mental retardation by use of a mouse model.

PubMed

Muers, Mary R; Sharpe, Jacqueline A; Garrick, David; Sloane-Stanley, Jacqueline; Nolan, Patrick M; Hacker, Terry; Wood, William G; Higgs, Douglas R; Gibbons, Richard J

2007-06-01

Extreme skewing of X-chromosome inactivation (XCI) is rare in the normal female population but is observed frequently in carriers of some X-linked mutations. Recently, it has been shown that various forms of X-linked mental retardation (XLMR) have a strong association with skewed XCI in female carriers, but the mechanisms underlying this skewing are unknown. ATR-X syndrome, caused by mutations in a ubiquitously expressed, chromatin-associated protein, provides a clear example of XLMR in which phenotypically normal female carriers virtually all have highly skewed XCI biased against the X chromosome that harbors the mutant allele. Here, we have used a mouse model to understand the processes causing skewed XCI. In female mice heterozygous for a null Atrx allele, we found that XCI is balanced early in embryogenesis but becomes skewed over the course of development, because of selection favoring cells expressing the wild-type Atrx allele. Unexpectedly, selection does not appear to be the result of general cellular-viability defects in Atrx-deficient cells, since it is restricted to specific stages of development and is not ongoing throughout the life of the animal. Instead, there is evidence that selection results from independent tissue-specific effects. This illustrates an important mechanism by which skewed XCI may occur in carriers of XLMR and provides insight into the normal role of ATRX in regulating cell fate.

Visual detection of particulates in x-ray images of processed meat products

NASA Astrophysics Data System (ADS)

Schatzki, Thomas F.; Young, Richard; Haff, Ron P.; Eye, J.; Wright, G.

1996-08-01

A study was conducted to test the efficacy of detecting particulate contaminants in processed meat samples by visual observation of line-scanned x-ray images. Six hundred field- collected processed-product samples were scanned at 230 cm2/s using 0.5 X 0.5-mm resolution and 50 kV, 13 mA excitation. The x-ray images were image corrected, digitally stored, and inspected off-line, using interactive image enhancement. Forty percent of the samples were spiked with added contaminants to establish the visual recognition of contaminants as a function of sample thickness (1 to 10 cm), texture of the x-ray image (smooth/textured), spike composition (wood/bone/glass), size (0.1 to 0.4 cm), and shape (splinter/round). The results were analyzed using a maximum likelihood logistic regression method. In packages less than 6 cm thick, 0.2-cm-thick bone chips were easily recognized, 0.1-cm glass splinters were recognized with some difficulty, while 0.4-cm-thick wood was generally missed. Operational feasibility in a time-constrained setting was confirmed. One half percent of the samples arriving from the field contained bone slivers > 1 cm long, 1/2% contained metallic material, while 4% contained particulates exceeding 0.3 cm in size. All of the latter appeared to be bone fragments.

Long-term 12 year follow-up of X-linked congenital retinoschisis

PubMed Central

Kjellström, Sten; Vijayasarathy, Camasamudram; Ponjavic, Vesna; Sieving, Paul A.; Andréasson, Sten

2010-01-01

Purpose To investigate the retinal structure and function during the progression of X-linked retinoschisis (XLRS) from childhood to adulthood. Methods Ten patients clinically diagnosed with XLRS were investigated at 6–15 years of age (mean age 9 years) with a follow-up 8 to 14 years later (mean 12 years). The patients underwent regular ophthalmic examination as well as testing of best corrected visual acuity (BCVA), visual field (VF) and assessment of full-field electroretinography (ERG) during their first visit. During the follow-up, the same clinical protocols were repeated. In addition, macular structure and function was examined with multifocal electroretinography (mfERG) and optical coherence tomography (OCT). The patients were 18–25 years of age (mean age 21 years) at the follow-up examination. All exons and exon-intron boundaries of RS1-gene were sequenced for gene mutations in 9 out of the 10 patients. Results Best corrected VA and VF were stable during this follow-up period. No significant progression in cone or rod function could be measured by full-field ERG. Multifocal electroretinography and OCT demonstrated a wide heterogeneity of macular changes in retinal structure and function at the time of follow-up visit. Three different mutations were detected in these nine patients, including a known nonsense mutation in exon 3, a novel insertion in exon 5 and an intronic mutation at 5' splice site of intron 3. Conclusions Clinical follow-up (mean 12 years) of ten young XLRS patients (mean age of 9 years) with a typical congenital retinoschisis phenotype revealed no significant decline in retinal function during this time period. MfERG and OCT demonstrated a wide variety of macular changes including structure and dysfunction. The XLRS disease was relatively stable during this period of observation and would afford opportunity for therapy studies to judge benefit against baseline and against the fellow eye. PMID:20569020

Adult-onset cerebello-brainstem dominant form of X-linked adrenoleukodystrophy presenting as multiple system atrophy: Case report and literature review

PubMed Central

Ogaki, Kotaro; Koga, Shunsuke; Aoki, Naoya; Lin, Wenlang; Suzuki, Kinuko; Ross, Owen A.; Dickson, Dennis W.

2015-01-01

X-linked adrenoleukodystrophy (X-ALD) is the most common peroxisomal disorder and is caused by ABCD1 mutations. A cerebello-brainstem dominant form that mainly involves the cerebellum and brainstem is summarized in a review of the literature, with autopsy confirmed cases exceedingly rare. We report a 69-year-old white man who was diagnosed with this rare disorder and describe neuropathologic, ultrastructural and genetic analyses. He did not have adrenal insufficiency or a family history of X-ALD or Addison’s disease. His initial symptom was temporary loss of eyesight at age 34 years. His major symptoms were chronic and progressive gait disorder, weakness in his lower extremities, and spasticity, as well as autonomic failure and cerebellar ataxia suggesting possible multiple system atrophy (MSA). He also had seizures, hearing loss, and sensory disturbances. His brain MRI showed no obvious atrophy or significant white matter pathology in cerebrum, brainstem or cerebellum. He died at age 69 years with a diagnosis of multiple system atrophy. Microscopic analysis showed mild, patchy myelin rarefaction with perivascular clusters of PAS-positive, CD68-positive macrophages in the white matter most prominent in the cerebellum and occipital lobe, but also affecting optic tract and internal capsule. Electron microscopy of cerebellar white matter showed cleft-like trilamellar cytoplasmic inclusions in macrophages typical of X-ALD, which prompted genetic analysis that revealed a novel ABCD1 mutation, p.R163G. Given the relatively mild pathological findings and long disease duration, it is likely that the observed pathology was the result of a slow and indolent disease process. We described a patient who had sporadic cerebello-brainstem dominant form of X-ALD with long clinical course, mild pathological findings, and an ABCD1 p.R163G substitution. We also review a total of 34 cases of adult-onset cerebello-brainstem dominant form of X-ALD. Although rare, X-ALD should be

X-linked recessive primary retinal dysplasia is linked to the Norrie disease locus.

PubMed

Ravia, Y; Braier-Goldstein, O; Bat-Miriam, K M; Erlich, S; Barkai, G; Goldman, B

1993-08-01

X-linked primary retinal dysplasia (PRD) refers to an abnormal proliferation of retinal tissue causing either its neural elements or its glial tissue to form folds, giving rise to gliosis. A Jewish family of oriental origin was previously reported by Godel and Goodman, in which a total of five males suffer from different degrees of blindness. The authors postulated that the described findings are distinguished from Norrie disease, since in this case no clinical findings, other than those associated with the eyes, were noticed in the affected males. In addition, two of the carrier females exhibit minimal eye changes. We have performed linkage analysis of the family using the L1.28, p58-1 and m27 beta probes, and DXS426 and MAOB associated microsatellites. Our results map the gene responsible for the disorder between the MAOB and DXS426, m27 beta and p58-1 loci, on the short arm of the X chromosome at Xp11.3, which suggest the possibility that the same gene is responsible for both primary retinal dysplasia and Norrie disease.

Node, Node-Link, and Node-Link-Group Diagrams: An Evaluation.

PubMed

Saket, Bahador; Simonetto, Paolo; Kobourov, Stephen; Börner, Katy

2014-12-01

Effectively showing the relationships between objects in a dataset is one of the main tasks in information visualization. Typically there is a well-defined notion of distance between pairs of objects, and traditional approaches such as principal component analysis or multi-dimensional scaling are used to place the objects as points in 2D space, so that similar objects are close to each other. In another typical setting, the dataset is visualized as a network graph, where related nodes are connected by links. More recently, datasets are also visualized as maps, where in addition to nodes and links, there is an explicit representation of groups and clusters. We consider these three Techniques, characterized by a progressive increase of the amount of encoded information: node diagrams, node-link diagrams and node-link-group diagrams. We assess these three types of diagrams with a controlled experiment that covers nine different tasks falling broadly in three categories: node-based tasks, network-based tasks and group-based tasks. Our findings indicate that adding links, or links and group representations, does not negatively impact performance (time and accuracy) of node-based tasks. Similarly, adding group representations does not negatively impact the performance of network-based tasks. Node-link-group diagrams outperform the others on group-based tasks. These conclusions contradict results in other studies, in similar but subtly different settings. Taken together, however, such results can have significant implications for the design of standard and domain snecific visualizations tools.

Congenital cataracts and other abnormalities in a female with 46.X, del(X)(q26q28)mat: A new locus for X-linked congenital cataract?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babul, R.; Chitayat, D.; Teshima, I.

1994-09-01

Three forms of X-linked congenital cataracts have been delineated: congenital cataract with posterior Y-sutural opacities in heterozygotes, congenital cataract and microcornea or microphthalmia and congenital cataract-dental syndrome (Nance-Horan syndrome). Of these, only the Nance-Horan syndrome has been mapped to Xp22.3-p21.1. However, Warburg has suggested that these different forms of X-linked congenital cataracts are due to deletions of varying sizes, placing them in the vicinity of the Nance-Horan syndrome region. We report on a female patient born to a 29-year-old primigravida woman who at birth was found to have hypotonia, dysmorphic facial features, hydrocephalus and dense white congenital bilateral cataracts. Othermore » ophthalmological findings included bilateral nystagmus and shallow orbits. Chromosome analysis revealed 46,X,del(X)(q26q28)mat. The mother, however, is phenotypically normal. Brain CT scan on the female infant revealed communicating hydrocephalus and a muscle biopsy showed congenital muscle fiber disproportion. An EMG and NCV were normal. At 4 years of age, her height and weight were below -3SD and her OFC was +2SD. Molecular studies using DNA markers located in Xq26-qter have revealed that the proximal breakpoint in the patient and her mother is defined by the HPRT locus while the distal breakpoint is defined by the locus DXS1108. This indicates that the deletion is not terminal but rather interstitial, retaining sequences proximal to the telomeric region. Other molecular studies are in progress to determine the X-inactivation status of the deleted chromosome in our patient and her mother as a possible explanation for the variation in the phenotype. These clinical and molecular findings suggest that another locus for X-linked congenital cataract exists at Xq26-28.« less

Glaucoma Severity and Participation in Diverse Social Roles: Does Visual Field Loss Matter?

PubMed

Yang, Yelin; Trope, Graham E; Buys, Yvonne M; Badley, Elizabeth M; Gignac, Monique A M; Shen, Carl; Jin, Ya-Ping

2016-07-01

To assess the association between glaucoma severity and participation in diverse social roles. Cross-sectional survey. Individuals with glaucoma, 50+, with visual acuity in the better eye >20/50 were enrolled. They were classified into 3 groups based on visual field loss in the better eye: mild [mean deviation (MD)>-6 dB], moderate (MD, -6 to -12 dB), and severe (MD<-12 dB). The validated Social Role Participation Questionnaire assessed respondents' perceptions of the importance, difficulty, and satisfaction with participation in 11 social role domains (eg, community events, travel). Differences between groups were examined using multivariate linear regression analyses. A total of 118 participants (52% female) were included: 60 mild, 29 moderate, and 29 severe. All social role domains were rated as important by all participants except for education and employment. Women (P<0.01), those with a partner (P<0.01), and those who were less depressed (P=0.03) reported higher scores of perceived importance of participating in social activities. Compared with those with mild glaucoma, individuals with severe glaucoma reported significantly more difficulty participating in community/religious/cultural events (P<0.01), travelling (P<0.01), and relationships with family members (P=0.01). They also reported less satisfaction with travelling (P=0.01) and social events (P=0.04). Participation in diverse social roles is valued by individuals with glaucoma. Severe visual field loss impedes involvement in and satisfaction with activities in community/religious/cultural events, travelling, and relationships with family members. Appropriate community and targeted interventions are needed to allow people with severe glaucoma to maintain active social participation-a key component to successful aging.

[X-linked adrenoleukodystrophy: a report of three cases. The importance of early diagnosis].

PubMed

López Úbeda, Marta; de Arriba Muñoz, Antonio; Ferrer Lozano, Marta; Labarta Aizpún, José I; García Jiménez, María C

2017-10-01

X-linked adrenoleukodystrophy is the most common peroxisomal disorder. This disease is caused by a defect in the ABCD1 gen. Saturated very long chain fatty acids are accumulated in serum, adrenal cortex and central nervous system white matter. The clinical spectrum is characterized by progressive neurological dysfunction and adrenal insufficiency with a devastating prognosis. We report a first case of X-linked adrenoleukodystrophy with fatal evolution which identified two asymptomatic family members and established a preventive treatment. Although there is no definitive cure, we stress the importance of family study and evaluation of the individual in situation of risk to establish an early preventive treatment and to give in each particular situation suitable professional advice. Sociedad Argentina de Pediatría.

Patulous Subarachnoid Space of the Optic Nerve Associated with X-Linked Hypophosphatemic Rickets.

PubMed

Galvez-Ruiz, Alberto; Chaudhry, Imtiaz

2013-01-01

Although the deficiency forms are the most common manifestations of rickets, there are other forms of rickets that are resistant to vitamin D. Of these, the most common is X-linked hypophosphatemic rickets. Rickets represents a group of multiple cranial bone disorders-craniosynostosis and the presence of Chari I malformation being the most notable-that explain the increase in intracranial pressure. We present a 4-year-old patient with an unusual association of X-linked hypophosphataemic rickets, bilateral proptosis, and prominent bilateral widening of the optic nerve sheaths. Although the association between intracranial hypertension and rickets is known, to the best of our knowledge, such a prominent distention of the subarachnoid space of the optic nerve without papilloedema has not been previously described.

Visualization of subcutaneous insulin injections by x-ray computed tomography

NASA Astrophysics Data System (ADS)

Thomsen, M.; Poulsen, M.; Bech, M.; Velroyen, A.; Herzen, J.; Beckmann, F.; Feidenhans'l, R.; Pfeiffer, F.

2012-11-01

We report how the three-dimensional structure of subcutaneous injections of soluble insulin can be visualized by x-ray computed tomography using an iodine based contrast agent. The injections investigated are performed ex vivo in porcine adipose tissue. Full tomography scans carried out at a laboratory x-ray source with a total acquisition time of about 1 min yield CT-images with an effective pixel size of 109 × 109 μm2. The depots are segmented using a modified Chan-Vese algorithm and we are able to observe differences in the shape of the injection depot and the position of the depot in the skin among equally performed injections. To overcome the beam hardening artefacts, which affect the quantitative prediction of the volume injected, we additionally present results concerning the visualization of two injections using synchrotron radiation. The spatial concentration distribution of iodine is calculated to show the dilution of the insulin drug inside the depot. Characterisation of the shape of the depot and the spatial concentration profile of the injected fluid is important knowledge when improving the clinical formulation of an insulin drug, the performance of injection devices and when predicting the effect of the drug through biomedical simulations.

Pathogenic variants in E3 ubiquitin ligase RLIM/RNF12 lead to a syndromic X-linked intellectual disability and behavior disorder.

PubMed

Frints, Suzanna G M; Ozanturk, Aysegul; Rodríguez Criado, Germán; Grasshoff, Ute; de Hoon, Bas; Field, Michael; Manouvrier-Hanu, Sylvie; E Hickey, Scott; Kammoun, Molka; Gripp, Karen W; Bauer, Claudia; Schroeder, Christopher; Toutain, Annick; Mihalic Mosher, Theresa; Kelly, Benjamin J; White, Peter; Dufke, Andreas; Rentmeester, Eveline; Moon, Sungjin; Koboldt, Daniel C; van Roozendaal, Kees E P; Hu, Hao; Haas, Stefan A; Ropers, Hans-Hilger; Murray, Lucinda; Haan, Eric; Shaw, Marie; Carroll, Renee; Friend, Kathryn; Liebelt, Jan; Hobson, Lynne; De Rademaeker, Marjan; Geraedts, Joep; Fryns, Jean-Pierre; Vermeesch, Joris; Raynaud, Martine; Riess, Olaf; Gribnau, Joost; Katsanis, Nicholas; Devriendt, Koen; Bauer, Peter; Gecz, Jozef; Golzio, Christelle; Gontan, Cristina; Kalscheuer, Vera M

2018-05-04

RLIM, also known as RNF12, is an X-linked E3 ubiquitin ligase acting as a negative regulator of LIM-domain containing transcription factors and participates in X-chromosome inactivation (XCI) in mice. We report the genetic and clinical findings of 84 individuals from nine unrelated families, eight of whom who have pathogenic variants in RLIM (RING finger LIM domain-interacting protein). A total of 40 affected males have X-linked intellectual disability (XLID) and variable behavioral anomalies with or without congenital malformations. In contrast, 44 heterozygous female carriers have normal cognition and behavior, but eight showed mild physical features. All RLIM variants identified are missense changes co-segregating with the phenotype and predicted to affect protein function. Eight of the nine altered amino acids are conserved and lie either within a domain essential for binding interacting proteins or in the C-terminal RING finger catalytic domain. In vitro experiments revealed that these amino acid changes in the RLIM RING finger impaired RLIM ubiquitin ligase activity. In vivo experiments in rlim mutant zebrafish showed that wild type RLIM rescued the zebrafish rlim phenotype, whereas the patient-specific missense RLIM variants failed to rescue the phenotype and thus represent likely severe loss-of-function mutations. In summary, we identified a spectrum of RLIM missense variants causing syndromic XLID and affecting the ubiquitin ligase activity of RLIM, suggesting that enzymatic activity of RLIM is required for normal development, cognition and behavior.

Autosomal Genes of Autosomal/X-Linked Duplicated Gene Pairs and Germ-Line Proliferation in Caenorhabditis elegans

PubMed Central

Maciejowski, John; Ahn, James Hyungsoo; Cipriani, Patricia Giselle; Killian, Darrell J.; Chaudhary, Aisha L.; Lee, Ji Inn; Voutev, Roumen; Johnsen, Robert C.; Baillie, David L.; Gunsalus, Kristin C.; Fitch, David H. A.; Hubbard, E. Jane Albert

2005-01-01

We report molecular genetic studies of three genes involved in early germ-line proliferation in Caenorhabditis elegans that lend unexpected insight into a germ-line/soma functional separation of autosomal/X-linked duplicated gene pairs. In a genetic screen for germ-line proliferation-defective mutants, we identified mutations in rpl-11.1 (L11 protein of the large ribosomal subunit), pab-1 [a poly(A)-binding protein], and glp-3/eft-3 (an elongation factor 1-α homolog). All three are members of autosome/X gene pairs. Consistent with a germ-line-restricted function of rpl-11.1 and pab-1, mutations in these genes extend life span and cause gigantism. We further examined the RNAi phenotypes of the three sets of rpl genes (rpl-11, rpl-24, and rpl-25) and found that for the two rpl genes with autosomal/X-linked pairs (rpl-11 and rpl-25), zygotic germ-line function is carried by the autosomal copy. Available RNAi results for highly conserved autosomal/X-linked gene pairs suggest that other duplicated genes may follow a similar trend. The three rpl and the pab-1/2 duplications predate the divergence between C. elegans and C. briggsae, while the eft-3/4 duplication appears to have occurred in the lineage to C. elegans after it diverged from C. briggsae. The duplicated C. briggsae orthologs of the three C. elegans autosomal/X-linked gene pairs also display functional differences between paralogs. We present hypotheses for evolutionary mechanisms that may underlie germ-line/soma subfunctionalization of duplicated genes, taking into account the role of X chromosome silencing in the germ line and analogous mammalian phenomena. PMID:15687263

A novel deletion mutation in RS1 gene caused X-linked juvenile retinoschisis in a Chinese family.

PubMed

Huang, Y; Mei, L; Gui, B; Su, W; Liang, D; Wu, L; Pan, Q

2014-11-01

X-linked juvenile retinoschisis (XLRS), a leading cause of juvenile macular degeneration, is characterized by a spoke-wheel pattern in the macular region of the retina and splitting of the neurosensory retina. This study aimed to identify the underlying genetic defect in a Chinese family with XLRS. The proband underwent complete ophthalmic examinations, including fundus examination, fundus autofluorescence, and optical coherence tomography. DNA extracted from proband and his younger brother was screened for mutations in RS1 gene. The detected RS1 mutation was tested in all available family members and 200 healthy controls. Reduced visual acuity, spoke-wheel pattern at the fovea, and split retina were observed in the proband. A novel frameshift mutation c.206-207delTG in the RS1 gene, leading to a truncated protein (p.L69fs16X), was identified in the proband and his younger brother. This mutation was not found in any unaffected member or in the healthy controls. The mother of the proband was hemizygous for this mutant allele. We identified a novel causative mutation of RS1 in a Chinese family with XLRS. This finding expands the mutation spectrum of RS1 and provides evidence for a phenotype-genotype study in XLRS.

A novel deletion mutation in RS1 gene caused X-linked juvenile retinoschisis in a Chinese family

PubMed Central

Huang, Y; Mei, L; Gui, B; Su, W; Liang, D; Wu, L; Pan, Q

2014-01-01

Purpose X-linked juvenile retinoschisis (XLRS), a leading cause of juvenile macular degeneration, is characterized by a spoke-wheel pattern in the macular region of the retina and splitting of the neurosensory retina. This study aimed to identify the underlying genetic defect in a Chinese family with XLRS. Methods The proband underwent complete ophthalmic examinations, including fundus examination, fundus autofluorescence, and optical coherence tomography. DNA extracted from proband and his younger brother was screened for mutations in RS1 gene. The detected RS1 mutation was tested in all available family members and 200 healthy controls. Results Reduced visual acuity, spoke-wheel pattern at the fovea, and split retina were observed in the proband. A novel frameshift mutation c.206-207delTG in the RS1 gene, leading to a truncated protein (p.L69fs16X), was identified in the proband and his younger brother. This mutation was not found in any unaffected member or in the healthy controls. The mother of the proband was hemizygous for this mutant allele. Conclusions We identified a novel causative mutation of RS1 in a Chinese family with XLRS. This finding expands the mutation spectrum of RS1 and provides evidence for a phenotype–genotype study in XLRS. PMID:25168411

A novel mutation in FRMD7 causing X-linked idiopathic congenital nystagmus in a large family

PubMed Central

He, Xiang; Gu, Feng; Wang, Yujing; Yan, Jinting; Zhang, Meng; Huang, Shangzhi

2008-01-01

Purpose To identify the gene responsible for causing an X-linked idiopathic congenital nystagmus (XLICN) in a six-generation Chinese family. Methods Forty-nine members of an XLICN family were recruited and examined after obtaining informed consent. Affected male individuals were genotyped with microsatellite markers around the FRMD7 locus. Mutations were comprehensively screened by direct sequencing using gene specific primers. An X-inactivation pattern was investigated by X chromosome methylation analysis. Results The patients showed phenotypes consistent with XLICN. Genotype analysis showed that male affected individuals in the family shared a common haplotype with the selected markers. Sequencing FRMD7 revealed a G>T transversion (c.812G>T) in exon 9, which caused a conservative substitution of Cys to Phe at codon 271 (p.C271F). This mutation co-segregated with all affected individuals and was present in the obligate, non-penetrant female carriers. However, the mutation was not observed in unaffected familial males or 400 control males. Females with the mutant gene could be affected or carrier and they shared the same inactivated X chromosome harboring the mutation in blood cells, which showed there is no clear causal link between X-inactivation pattern and phenotype. Conclusions We identified a novel mutation in FRMD7 and confirmed the role of this mutation in the pathogenesis of X-linked congenital nystagmus. PMID:18246032

Microsatellites within the feline androgen receptor are suitable for X chromosome-linked clonality testing in archival material.

PubMed

Farwick, Nadine M; Klopfleisch, Robert; Gruber, Achim D; Weiss, Alexander Th A

2017-04-01

Objectives A hallmark of neoplasms is their origin from a single cell; that is, clonality. Many techniques have been developed in human medicine to utilise this feature of tumours for diagnostic purposes. One approach is X chromosome-linked clonality testing using polymorphisms of genes encoded by genes on the X chromosome. The aim of this study was to determine if the feline androgen receptor gene was suitable for X chromosome-linked clonality testing. Methods The feline androgen receptor gene was characterised and used to test clonality of feline lymphomas by PCR and polyacrylamide gel electrophoresis, using archival formalin-fixed, paraffin-embedded material. Results Clonality of the feline lymphomas under study was confirmed and the gene locus was shown to represent a suitable target in clonality testing. Conclusions and relevance Because there are some pitfalls of using X chromosome-linked clonality testing, further studies are necessary to establish this technique in the cat.

Mutations in apoptosis-inducing factor cause X-linked recessive auditory neuropathy spectrum disorder

PubMed Central

Zong, Liang; Guan, Jing; Ealy, Megan; Zhang, Qiujing; Wang, Dayong; Wang, Hongyang; Zhao, Yali; Shen, Zhirong; Campbell, Colleen A; Wang, Fengchao; Yang, Ju; Sun, Wei; Lan, Lan; Ding, Dalian; Xie, Linyi; Qi, Yue; Lou, Xin; Huang, Xusheng; Shi, Qiang; Chang, Suhua; Xiong, Wenping; Yin, Zifang; Yu, Ning; Zhao, Hui; Wang, Jun; Wang, Jing; Salvi, Richard J; Petit, Christine; Smith, Richard J H; Wang, Qiuju

2015-01-01

Background Auditory neuropathy spectrum disorder (ANSD) is a form of hearing loss in which auditory signal transmission from the inner ear to the auditory nerve and brain stem is distorted, giving rise to speech perception difficulties beyond that expected for the observed degree of hearing loss. For many cases of ANSD, the underlying molecular pathology and the site of lesion remain unclear. The X-linked form of the condition, AUNX1, has been mapped to Xq23-q27.3, although the causative gene has yet to be identified. Methods We performed whole-exome sequencing on DNA samples from the AUNX1 family and another small phenotypically similar but unrelated ANSD family. Results We identified two missense mutations in AIFM1 in these families: c.1352G>A (p.R451Q) in the AUNX1 family and c.1030C>T (p.L344F) in the second ANSD family. Mutation screening in a large cohort of 3 additional unrelated families and 93 sporadic cases with ANSD identified 9 more missense mutations in AIFM1. Bioinformatics analysis and expression studies support this gene as being causative of ANSD. Conclusions Variants in AIFM1 gene are a common cause of familial and sporadic ANSD and provide insight into the expanded spectrum of AIFM1-associated diseases. The finding of cochlear nerve hypoplasia in some patients was AIFM1-related ANSD implies that MRI may be of value in localising the site of lesion and suggests that cochlea implantation in these patients may have limited success. PMID:25986071

X-linked agammaglobulinemia in northern Thailand.

PubMed

Trakultivakorn, Muthita; Ochs, Hans D

2006-03-01

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by a failure to generate immunoglobulins of all isotypes due to the absence of mature B cells and plasma cells, secondary to mutations in the Bruton's tyrosine kinase (Btk) gene. We report six patients with XLA, confirmed by mutation analysis, from northern Thailand. The mean age of onset was 2.5 years and the mean age at diagnosis was 7.3 years. All patients had a history of otitis media, pneumonia and arthritis at the time of diagnosis, five patients had developed bronchiectasis and 3 patients septicemia. Other infections reported included sinusitis (5/6), pericarditis (1/6), meningitis (1/6) and pyoderma (1/6). Haemophilus influenzae, Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus were isolated on multiple occasions. One patient died of sepsis at the age of 16 years. These observations demonstrate that early diagnosis and treatment can improve prognosis and quality of life.

Comparison of peripapillary retinal nerve fiber layer loss and visual outcome in fellow eyes following sequential bilateral non-arteritic anterior ischemic optic neuropathy.

PubMed

Dotan, Gad; Kesler, Anat; Naftaliev, Elvira; Skarf, Barry

2015-05-01

To report on the correlation of structural damage to the axons of the optic nerve and visual outcome following bilateral non-arteritic anterior ischemic optic neuropathy. A retrospective review of the medical records of 25 patients with bilateral sequential non-arteritic anterior ischemic optic neuropathy was performed. Outcome measures were peripapillary retinal nerve fiber layer thickness measured with the Stratus optical coherence tomography scanner, visual acuity and visual field loss. Median peripapillary retinal nerve fiber layer (RNFL) thickness, mean deviation (MD) of visual field, and visual acuity of initially involved NAION eyes (54.00 µm, -17.77 decibels (dB), 0.4, respectively) were comparable to the same parameters measured following development of second NAION event in the other eye (53.70 µm, p = 0.740; -16.83 dB, p = 0.692; 0.4, p = 0.942, respectively). In patients with bilateral NAION, there was a significant correlation of peripapillary RNFL thickness (r = 0.583, p = 0.002) and MD of the visual field (r = 0.457, p = 0.042) for the pairs of affected eyes, whereas a poor correlation was found in visual acuity of these eyes (r = 0.279, p = 0.176). Peripapillary RNFL thickness following NAION was positively correlated with MD of visual field (r = 0.312, p = 0.043) and negatively correlated with logMAR visual acuity (r = -0.365, p = 0.009). In patients who experience bilateral NAION, the magnitude of RNFL loss is similar in each eye. There is a greater similarity in visual field loss than in visual acuity between the two affected eyes with NAION of the same individual.

Does Central Vision Loss Impair Visual Search Performance of Adults More than Children?

PubMed

Satgunam, PremNandhini; Luo, Gang

2018-05-01

In general, young adults with normal vision show the best visual search performance when compared with children and older adults. Through our study, we show that this trend is not observed in individuals with vision impairment. An interaction effect of vision impairment with visual development and aging is observed. Performance in many visual tasks typically shows improvement with age until young adulthood and then declines with aging. Using a visual search task, this study investigated whether a similar age effect on performance is present in people with central vision loss. A total of 98 participants, 37 with normal sight (NS) and 61 with visual impairment (VI) searched for targets in 150 real-world digital images. Search performance was quantified by an integrated measure combining speed and accuracy. Participant ages ranged from 5 to 74 years, visual acuity from -0.14 (20/14.5) to 1.16 logMAR (20/290), and log contrast sensitivity (CS) from 0.48 to 2.0. Data analysis was performed with participants divided into three age groups: children (aged <14 years, n = 25), young adults (aged 14 to 45 years, n = 47), and older adults (aged >45 years, n = 26). Regression (r = 0.7) revealed CS (P < .001) and age (P = .003) were significant predictors of search performance. Performance of VI participants was normalized to the age-matched average performance of the NS group. In the VI group, it was found that children's normalized performance (52%) was better than both young (39%, P = .05) and older (40%, P = .048) adults. Unlike NS participants, young adults in the VI group may not have search ability superior to children with VI, despite having the same level of visual functions (quantified by visual acuity and CS). This could be because of vision impairment limiting the developmental acquisition of the age dividend for peak performance. Older adults in the VI group had the worst performance, indicating an interaction of aging.

Human Erythropoietin Effect in Postoperative Visual Loss Following Spine Surgery: A Case Report

PubMed Central

Hassani, Valiollah; Homaei, Mohammad Mohsen; Shahbazi, Ali; Zamani, Mohammad Mahdi; Safari, Saeid; Nadi, Shermila; Rahimizadeh, Abolfazl; Lashkari, Mohammad Hossein; Alizadeh zendehrood, Siamak

2014-01-01

Introduction: Postoperative visual loss (POVL) has become the focus of attention for anesthesiologists as a hallmark of perioperative management in spine surgery. A number of Intraoperative and postoperative factors has been documented but the exact etiology is still unclear. Nowadays, perioperative management and also complete curing of POLV is a big question of ophthalmologists and anesthesiologists. The purpose of this case report is to present a unique experience of complete curing the POLV. Case Presentation: Our patient was a 61-year-old man, with 75 kg weight and 180 cm height. The patient had no history of visual impairment except mild cataract in his right eye. The patient had a history of diffuse idiopathic skeletal hyperostosis (DISH). The patient had undergone lumbar surgery in prone position. The operation time was about 6 hours. About 30 minutes after transferring to postanesthesia care unit (PACU), patient was awake and complained of losing his eyesight. There was no vision and light perception in his right eye on primary examination. Urgent ophthalmologist consultation was requested. In ophthalmology examinations, the pupil reflex to light was absent in the right eye. After obtaining patients and his family informed consent, four hours after the operation, 40000 I.U. of recombinant human erythropoietin (rhEPO) was administered for patient in PACU (IV infusion, in 30 min). An ophthalmologist visited him every 6 hours after administration of rhEPO. The patient was transferred to intensive care unit (ICU) one hour later with total visual loss in the right eye. Ophthalmologic examination after the second dose of rhEPO, 30 hours after the operation, reported pupil reflex enhancement and light perception in his right eye. Finally the third dose of rhEPO (40000 I.U., IV infusion) was administered on the third day. Ophthalmologic examination after the third dose of rhEPO, 60 hours after the operation, reported normal pupillary light reflex of the right eye

Ube3a loss increases excitability and blunts orientation tuning in the visual cortex of Angelman syndrome model mice.

PubMed

Wallace, Michael L; van Woerden, Geeske M; Elgersma, Ype; Smith, Spencer L; Philpot, Benjamin D

2017-07-01

Angelman syndrome (AS) is a neurodevelopmental disorder caused by loss of the maternally inherited allele of UBE3A Ube3a STOP/p+ mice recapitulate major features of AS in humans and allow conditional reinstatement of maternal Ube3a with the expression of Cre recombinase. We have recently shown that AS model mice exhibit reduced inhibitory drive onto layer (L)2/3 pyramidal neurons of visual cortex, which contributes to a synaptic excitatory/inhibitory imbalance. However, it remains unclear how this loss of inhibitory drive affects neural circuits in vivo. Here we examined visual cortical response properties in individual neurons to explore the consequences of Ube3a loss on intact cortical circuits and processing. Using in vivo patch-clamp electrophysiology, we measured the visually evoked responses to square-wave drifting gratings in L2/3 regular-spiking (RS) neurons in control mice, Ube3a -deficient mice, and mice in which Ube3a was conditionally reinstated in GABAergic neurons. We found that Ube3a -deficient mice exhibited enhanced pyramidal neuron excitability in vivo as well as weaker orientation tuning. These observations are the first to show alterations in cortical computation in an AS model, and they suggest a basis for cortical dysfunction in AS. NEW & NOTEWORTHY Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by the loss of the gene UBE3A Using electrophysiological recording in vivo, we describe visual cortical dysfunctions in a mouse model of AS. Aberrant cellular properties in AS model mice could be improved by reinstating Ube3a in inhibitory neurons. These findings suggest that inhibitory neurons play a substantial role in the pathogenesis of AS. Copyright © 2017 the American Physiological Society.

Developmental dyslexia: exploring how much phonological and visual attention span disorders are linked to simultaneous auditory processing deficits.

PubMed

Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

2013-07-01

The simultaneous auditory processing skills of 17 dyslexic children and 17 skilled readers were measured using a dichotic listening task. Results showed that the dyslexic children exhibited difficulties reporting syllabic material when presented simultaneously. As a measure of simultaneous visual processing, visual attention span skills were assessed in the dyslexic children. We presented the dyslexic children with a phonological short-term memory task and a phonemic awareness task to quantify their phonological skills. Visual attention spans correlated positively with individual scores obtained on the dichotic listening task while phonological skills did not correlate with either dichotic scores or visual attention span measures. Moreover, all the dyslexic children with a dichotic listening deficit showed a simultaneous visual processing deficit, and a substantial number of dyslexic children exhibited phonological processing deficits whether or not they exhibited low dichotic listening scores. These findings suggest that processing simultaneous auditory stimuli may be impaired in dyslexic children regardless of phonological processing difficulties and be linked to similar problems in the visual modality.

Carbonic Anhydrase Inhibitors for the Treatment of Cystic Macular Lesions in Children With X-Linked Juvenile Retinoschisis.

PubMed

Verbakel, Sanne K; van de Ven, Johannes P H; Le Blanc, Linda M P; Groenewoud, Joannes M M; de Jong, Eiko K; Klevering, B Jeroen; Hoyng, Carel B

2016-10-01

Little is known regarding the therapeutic effect of carbonic anhydrase inhibitors (CAIs) in the management of cystic macular lesions in children with X-linked juvenile retinoschisis (XLRS) despite the fact that this disease often manifests during childhood. Therefore, our goal was to determine the efficacy of CAIs in the treatment of cystic macular lesions in children with XLRS. We used CAIs to treat cystic macular lesions in 18 eyes of nine children with XLRS. We evaluated the therapeutic effect of CAI treatment with the best-corrected visual acuity and foveal zone thickness (FZT) with spectral-domain optical coherence tomography. A reduction of at least 22.4% in FZT was defined as objective evidence of response. Five of nine (55.6%) XLRS patients showed a significant reduction of FZT in both eyes over a median treatment interval of 6.8 months (range, 1-23). In four of five (80.0%) patients, this reduction was already apparent after 1 month of treatment. An improvement of visual acuity was observed in five eyes (27.8%) of three patients (33.3%). Six patients (66.6%) reported minor side effects. Treatment with CAIs decreased FZT in more than half of the children with XLRS. This effect was observed within 1 month in the majority of patients. Carbonic anhydrase inhibitor treatment restores retinal anatomy and may contribute to creating optimal circumstances for gene therapy.

A CLINICIAN'S GUIDE TO X-LINKED HYPOPHOSPHATEMIA

PubMed Central

Carpenter, Thomas O.; Imel, Erik A.; Holm, Ingrid A.; Jan de Beur, Suzanne M.; Insogna, Karl L.

2011-01-01

X-linked hypophosphatemia (XLH) is the prototypic disorder of renal phosphate wasting, and the most common form of heritable rickets. Physicians, patients, and XLH support groups have all expressed concerns about the dearth of information about this disease and the lack of treatment guidelines which frequently lead to missed diagnoses or mismanagement. This perspective addresses the recommendation by conferees for the dissemination of concise and accessible treatment guidelines for clinicians arising from the “Advances in Rare Bone Diseases Scientific Conference,” held at the National Institutes of Health in October 2008. We briefly review the clinical and pathophysiologic features of the disorder, and offer this guide in response to the conference recommendation, base on our collective accumulated experience in the management of this complex disorder. PMID:21538511

Fatal hepatic hemorrhage by peliosis hepatis in X-linked myotubular myopathy: a case report.

PubMed

Motoki, T; Fukuda, M; Nakano, T; Matsukage, S; Fukui, A; Akiyoshi, S; Hayashi, Y K; Ishii, E; Nishino, I

2013-11-01

We report a 5-year-old boy with X-linked myotubular myopathy complicated by peliosis hepatis. At birth, he was affected with marked generalized muscle hypotonia and weakness, which required permanent ventilatory support, and was bedridden for life. He died of acute fatal hepatic hemorrhage after using a mechanical in-exsufflator. Peliosis hepatis, defined as multiple, variable-sized, cystic blood-filled spaces through the liver parenchyma, was confirmed by autopsy. To avoid fatal hepatic hemorrhage by peliosis hepatis, routine hepatic function tests and abdominal imaging tests should be performed for patients with X-linked myotubular myopathy, especially at the time of using artificial respiration. Copyright © 2013 Elsevier B.V. All rights reserved.

Pollen structure visualization using high-resolution laboratory-based hard X-ray tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qiong; Gluch, Jürgen; Krüger, Peter

A laboratory-based X-ray microscope is used to investigate the 3D structure of unstained whole pollen grains. For the first time, high-resolution laboratory-based hard X-ray microscopy is applied to study pollen grains. Based on the efficient acquisition of statistically relevant information-rich images using Zernike phase contrast, both surface- and internal structures of pine pollen - including exine, intine and cellular structures - are clearly visualized. The specific volumes of these structures are calculated from the tomographic data. The systematic three-dimensional study of pollen grains provides morphological and structural information about taxonomic characters that are essential in palynology. Such studies have amore » direct impact on disciplines such as forestry, agriculture, horticulture, plant breeding and biodiversity. - Highlights: • The unstained whole pine pollen was visualized by high-resolution laboratory-based HXRM for the first time. • The comparison study of pollen grains by LM, SEM and high-resolution laboratory-based HXRM. • Phase contrast imaging provides significantly higher contrast of the raw images compared to absorption contrast imaging. • Surface and internal structure of the pine pollen including exine, intine and cellular structures are clearly visualized. • 3D volume data of unstained whole pollen grains are acquired and the specific volumes of the different layer are calculated.« less

Genetic Analysis of X-Chromosome Dosage Compensation in Caenorhabditis elegans

PubMed Central

Meneely, Philip M.; Wood, William B.

1987-01-01

We have shown that the phenotypes resulting from hypomorphic mutations (causing reduction but not complete loss of function) in two X-linked genes can be used as a genetic assay for X-chromosome dosage compensation in Caenorhabditis elegans between males ( XO) and hermaphrodites (XX). In addition we show that recessive mutations in two autosomal genes, dpy-21 V and dpy-26 IV, suppress the phenotypes resulting from the X-linked hypomorphic mutations, but not the phenotypes resulting from comparable autosomal hypomorphic mutations. This result strongly suggests that the dpy-21 and dpy-26 mutations cause increased X expression, implying that the normal function of these genes may be to lower the expression of X-linked genes. Recessive mutations in two other dpy genes, dpy-22 X and dpy-23 X, increase the severity of phenotypes resulting from some X-linked hypomorphic mutations, although dpy-23 may affect the phenotypes resulting from the autosomal hypomorphs as well. The mutations in all four of the dpy genes show their effects in both XO and XX animals, although to different degrees. Mutations in 18 other dpy genes do not show these effects. PMID:3666440

X-linked ocular albinism in Blacks. Ocular albinism cum pigmento.

PubMed

O'Donnell, F E; Green, W R; Fleischman, J A; Hambrick, G W

1978-07-01

X-linked ocular albinism can be an unsuspected cause of congenital nystagmus in blacks. In this study, eight of ten black ocular albinos from two kindreds had nonalbinotic, moderately pigmented fundi and no transillumination of the iris. We refer to this paradoxical condition as "ocular albinism cum pigmento." The only constant ophthalmoscopic feature was a foveal hypoplasia. Biopsy of clinically normal skin to demonstrate giant pigment granules is the most accurate means of diagnosis.

Steam tables for pure water as an ActiveX component in Visual Basic 6.0

NASA Astrophysics Data System (ADS)

Verma, Mahendra P.

2003-11-01

The IAPWS-95 formulation for the thermodynamic properties of pure water was implemented as an ActiveX component ( SteamTables) in Visual Basic 6.0. For input parameters as temperature ( T=190-2000 K) and pressure ( P=3.23×10 -8-10,000 MPa) the program SteamTables calculates the following properties: volume ( V), density ( D), compressibility factor ( Z0), internal energy ( U), enthalpy ( H), Gibbs free energy ( G), Helmholtz free energy ( A), entropy ( S), heat capacity at constant pressure ( Cp), heat capacity at constant volume ( Cv), coefficient of thermal expansion ( CTE), isothermal compressibility ( Ziso), velocity of sound ( VelS), partial derivative of P with T at constant V (d Pd T), partial derivative of T with V at constant P (d Td V), partial derivative of V with P at constant T (d Vd P), Joule-Thomson coefficient ( JTC), isothermal throttling coefficient ( IJTC), viscosity ( Vis), thermal conductivity ( ThrmCond), surface tension ( SurfTen), Prandtl number ( PrdNum) and dielectric constant ( DielCons) for the liquid and vapor phases of pure water. It also calculates T as a function of P (or P as a function of T) along the sublimation, saturation and critical isochor curves, depending on the values of P (or T). The SteamTables can be incorporated in a program in any computer language, which supports object link embedding (OLE) in the Windows environment. An application of SteamTables is illustrated in a program in Visual Basic 6.0 to tabulate the values of the thermodynamic properties of water and vapor. Similarly, four functions, Temperature(Press), Pressure(Temp), State(Temp, Press) and WtrStmTbls(Temp, Press, Nphs, Nprop), where Temp, Press, Nphs and Nprop are temperature, pressure, phase number and property number, respectively, are written in Visual Basic for Applications (VBA) to use the SteamTables in a workbook in MS-Excel.

Visual loss after corrective surgery for pediatric scoliosis: incidence and risk factors from a nationwide database.

PubMed

De la Garza-Ramos, Rafael; Samdani, Amer F; Sponseller, Paul D; Ain, Michael C; Miller, Neil R; Shaffrey, Christopher I; Sciubba, Daniel M

2016-04-01

Perioperative visual loss (POVL) after spinal deformity surgery is an uncommon but severe complication. Data on the incidence and risk factors of this complication after corrective surgery in the pediatric population are limited. The present study aimed to investigate nationwide estimates of POVL after corrective surgery for pediatric scoliosis. This is a retrospective study that uses a nationwide database. The sample includes 42,339 patients under the age of 18 who underwent surgery for idiopathic scoliosis. The outcome measures were incidence of POVL and risk factors. Patients under the age of 18 who underwent elective surgery for idiopathic scoliosis between 2002 and 2011 were identified using the Nationwide Inpatient Sample database. The incidence of POVL (ischemic optic neuropathy, central retinal artery occlusion, or cortical blindness) was estimated after application of discharge weights. Demographics, comorbidities, and operative parameters were compared between patients with and without visual loss. A multivariate logistic regression was performed to identify significant risk factors for POVL development. No funds were received in support of this work. The incidence of POVL was 1.6 per 1,000 procedures (0.16%). Patients with visual loss were significantly more likely to be younger and male, have Medicaid as insurance, and undergo fusion of eight or more spinal levels compared with patients without visual loss. Following multivariate analysis, older patients (odds ratio [OR]: 0.84; 95% confidence interval [CI]: 0.77-0.91) and female patients (OR: 0.08; 95% CI: 0.04-0.14) were significantly less likely to develop POVL compared with younger and male patients. On the other hand, having Medicaid as insurance (OR: 2.13;95% CI: 1.32-3.45), history of deficiency anemia (OR: 8.64; 95% CI: 5.46-14.31), and fusion of eight or more spinal levels (OR: 2.40; 95% CI: 1.34-4.30) were all independently associated with POVL. In this nationwide study, the incidence of POVL

How To Produce Linked Audio and Still Visual Materials. Teaching and Learning in Higher Education, 16.

ERIC Educational Resources Information Center

Ellington, Henry

A sequel to the booklet "A Review of the Different Types of Instructional Materials Available to Teachers and Lecturers," this booklet begins by looking at the various ways in which linked audio and still visual materials can be used in different instructional situations, i.e., mass instruction, individualized learning, and group learning. Some of…

X-linked juvenile retinoschisis in a consanguineous family: phenotypic variability and report of a homozygous female patient.

PubMed

Gliem, Martin; Holz, Frank G; Stöhr, Heidi; Weber, Bernhard H F; Charbel Issa, Peter

2014-12-01

To describe the phenotypic variability in a consanguineous family with genetically confirmed X-linked retinoschisis. Five patients, including one homozygous female, were characterized by clinical examination, optical coherence tomography, fundus autofluorescence, mapping of macular pigment optical density, electroretinography, and DNA testing. The 36-year-old male index patient showed a ring of enhanced autofluorescence and outer retinal atrophy on optical coherence tomography. Electroretinography testing revealed a reduced a/b ratio. His mother presented with a central atrophic retina with markedly reduced autofluorescence signal and a surrounding ring of enhanced autofluorescence. The 40-year-old brother of the index patient and his 2 sons showed characteristic signs for X-linked retinoschisis, including retinal schisis and a reduced a/b ratio. Genetic testing revealed a c.293C>A mutation in the RS1 gene in all affected family members while the mother of the index patient was homozygous for this mutation. X-linked retinoschisis can present with a wide phenotypic variability. Here, detailed family history and genetic testing established the diagnosis of X-linked retinoschisis despite striking differences in phenotypic presentation in affected subjects, homozygosity of one affected female, and seemingly dominant inheritance in three subsequent generations because of multiple consanguinity.

Loss of Visual Working Memory within Seconds: The Combined Use of Refreshable and Non-Refreshable Features

ERIC Educational Resources Information Center

Ricker, Timothy J.; Cowan, Nelson

2010-01-01

We reexamine the role of time in the loss of information from working memory, the limited information accessible for cognitive tasks. The controversial issue of whether working memory deteriorates over time was investigated using arrays of unconventional visual characters. Each array was followed by a postperceptual mask, a variable retention…

Hydrothermal Diamond Anvil Cell (HDAC): From Visual Observation to X-ray Absorption Spectroscopy

NASA Astrophysics Data System (ADS)

Bassett, W. A.; Mibe, K.

2006-05-01

A fluid sample contained in a Re gasket between two diamond anvils can be subjected to pressures up to 2.5 GPa and temperatures up to 1200°C in a resistively heated hydrothermal diamond anvil cell (HDAC). Thermocouples are used to measure temperature. The constant-volume sample chamber permits isochoric measurements that can be used to determine pressure from the equation of state of H2O and to map phases and properties in P-T space. A movie of reactions between K-feldspar and water up to 2.5 GPa and 880°C illustrates the use of visual observations for mapping coexisting solution, melt, and solid phases. X-ray absorption spectroscopy of ZnBr2 in solution up to 500°C and 500 MPa shows hydrogen bond breaking in the hydration shells of the ZnBr42- and Br- ions with increasing temperature. In other studies the stability field of ikaite (CaCO3·6H2O) has been mapped by visual observation and Raman spectroscopy; the phases of montmorillonite have been mapped by X-ray diffraction; and the leaching of Pb from zircon has been measured by X-ray microprobe.

Mutually exclusive expression of human red and green visual pigment-reporter transgenes occurs at high frequency in murine cone photoreceptors.

PubMed

Wang, Y; Smallwood, P M; Cowan, M; Blesh, D; Lawler, A; Nathans, J

1999-04-27

This study examines the mechanism of mutually exclusive expression of the human X-linked red and green visual pigment genes in their respective cone photoreceptors by asking whether this expression pattern can be produced in a mammal that normally carries only a single X-linked visual pigment gene. To address this question, we generated transgenic mice that carry a single copy of a minimal human X chromosome visual pigment gene array in which the red and green pigment gene transcription units were replaced, respectively, by alkaline phosphatase and beta-galactosidase reporters. As determined by histochemical staining, the reporters are expressed exclusively in cone photoreceptor cells. In 20 transgenic mice carrying any one of three independent transgene insertion events, an average of 63% of expressing cones have alkaline phosphatase activity, 10% have beta-galactosidase activity, and 27% have activity for both reporters. Thus, mutually exclusive expression of red and green pigment transgenes can be achieved in a large fraction of cones in a dichromat mammal, suggesting a facile evolutionary path for the development of trichromacy after visual pigment gene duplication. These observations are consistent with a model of visual pigment expression in which stochastic pairing occurs between a locus control region and either the red or the green pigment gene promotor.

Reduction of severe visual loss and complications following intra-arterial chemotherapy (IAC) for refractory retinoblastoma.

PubMed

Reddy, M Ashwin; Naeem, Zishan; Duncan, Catriona; Robertson, Fergus; Herod, Jane; Rennie, Adam; Liasis, Alki; Thompson, Dorothy Ann; Sagoo, Mandeep

2017-12-01

Intra-arterial chemotherapy (IAC) for retinoblastoma has been documented as causing visual loss and ocular motility problems. A lack of safety data has precluded its acceptance in all centres. Retrospective cohort study of patients with retinoblastoma from 2013 to 2015 who had a healthy foveola and relapsed following systemic chemotherapy. All required IAC. The correlation of complications with doses of melphalan +/- topotecan used and putative catheterisation complications was assessed. Ocular complications were determined using vision, macular (including pattern visual evoked potentials (PVEPs)), retinal electroretinograms (ERGs) and ocular motility functions. Efficacy (tumour control) was also assessed. All eyes had age appropriate doses of melphalan with five having additional doses of topotecan. Severe physiological reactions requiring adrenaline were seen in six patients during the catheterisation procedure. Difficulty was documented in accessing the ophthalmic artery in 7/27 catheterisations. The median/mean number of courses of chemotherapy was three. No child had severe visual loss as assessed by age appropriate tests (median follow-up 20.9 months, range 3.7-35.2 months). One child had nasal choroidal ischaemia and a sixth nerve palsy. Post-IAC PVEPs were performed in eight and reported as normal. All post-IAC ERGs were normal apart from one (total dose 20 mg melphalan 0.8 mg topotecan). Tumour control was achieved in six of nine cases. The proportion of visual and ocular motility complications may be reduced by providing age-adjusted doses of melphalan. Dose rather than complications from catheterisation is the most important risk factor for ocular injury. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Consumption‐Based Conservation Targeting: Linking Biodiversity Loss to Upstream Demand through a Global Wildlife Footprint

PubMed Central

Berlow, Eric; Conlisk, Erin; Erb, Karlheinz; Iha, Katsunori; Martinez, Neo; Newman, Erica A.; Plutzar, Christoph; Smith, Adam B.; Harte, John

2016-01-01

Abstract Although most conservation efforts address the direct, local causes of biodiversity loss, effective long‐term conservation will require complementary efforts to reduce the upstream economic pressures, such as demands for food and forest products, which ultimately drive these downstream losses. Here, we present a wildlife footprint analysis that links global losses of wild birds to consumer purchases across 57 economic sectors in 129 regions. The United States, India, China, and Brazil have the largest regional wildlife footprints, while per‐person footprints are highest in Mongolia, Australia, Botswana, and the United Arab Emirates. A US$100 purchase of bovine meat or rice products occupies approximately 0.1 km2 of wild bird ranges, displacing 1–2 individual birds, for 1 year. Globally significant importer regions, including Japan, the United Kingdom, Germany, Italy, and France, have large footprints that drive wildlife losses elsewhere in the world and represent important targets for consumption‐focused conservation attention. PMID:29104616

X-linked acrogigantism syndrome: clinical profile and therapeutic responses.

PubMed

Beckers, Albert; Lodish, Maya Beth; Trivellin, Giampaolo; Rostomyan, Liliya; Lee, Misu; Faucz, Fabio R; Yuan, Bo; Choong, Catherine S; Caberg, Jean-Hubert; Verrua, Elisa; Naves, Luciana Ansaneli; Cheetham, Tim D; Young, Jacques; Lysy, Philippe A; Petrossians, Patrick; Cotterill, Andrew; Shah, Nalini Samir; Metzger, Daniel; Castermans, Emilie; Ambrosio, Maria Rosaria; Villa, Chiara; Strebkova, Natalia; Mazerkina, Nadia; Gaillard, Stéphan; Barra, Gustavo Barcelos; Casulari, Luis Augusto; Neggers, Sebastian J; Salvatori, Roberto; Jaffrain-Rea, Marie-Lise; Zacharin, Margaret; Santamaria, Beatriz Lecumberri; Zacharieva, Sabina; Lim, Ee Mun; Mantovani, Giovanna; Zatelli, Maria Chaira; Collins, Michael T; Bonneville, Jean-François; Quezado, Martha; Chittiboina, Prashant; Oldfield, Edward H; Bours, Vincent; Liu, Pengfei; W de Herder, Wouter; Pellegata, Natalia; Lupski, James R; Daly, Adrian F; Stratakis, Constantine A

2015-06-01

X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2-3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management. © 2015 Society for Endocrinology.

Linkage and candidate gene analysis of X-linked familial exudative vitreoretinopathy.

PubMed

Shastry, B S; Hejtmancik, J F; Plager, D A; Hartzer, M K; Trese, M T

1995-05-20

Familial exudative vitreoretinopathy (FEVR) is a hereditary eye disorder characterized by avascularity of the peripheral retina, retinal exudates, tractional detachment, and retinal folds. The disorder is most commonly transmitted as an autosomal dominant trait, but X-linked transmission also occurs. To initiate the process of identifying the gene responsible for the X-linked disorder, linkage analysis has been performed with three previously unreported three- or four-generation families. Two-point analysis showed linkage to MAOA (Zmax = 2.1, theta max = 0) and DXS228 (Zmax = 0.5, theta max = 0.11), and this was further confirmed by multipoint analysis with these same markers (Zmax = 2.81 at MAOA), which both lie near the gene causing Norrie disease. Molecular genetic analysis further reveals a missense mutation (R121W) in the third exon of the Norrie's disease gene that perfectly cosegregates with the disease through three generations in one family. This mutation was not detected in the unaffected family members and six normal unrelated controls, suggesting that it is likely to be the pathogenic mutation. Additionally, a polymorphic missense mutation (H127R) was detected in a severely affected patient.

A STUDY OF FACTORS ASSOCIATED WITH LOSS OF DISTANT VISUAL ACUITY AMONG CHILDREN FIVE TO ELEVEN YEARS OF AGE IN HIROSHIMA AND NAGASAKI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, R.W.

1962-08-01

An evaluation of the effects of inheritance and environment on the loss of distant visual acuity in 7117 Japanese grammar school children is presented. Unique features of the survey included: entry of the child in the study during gestation; measurement of pediatric, neurologic, and dental health, of physical and intellectual growth, and of circumstances of the in utero and home environments, and the opportunity to appraise the effects of inbreeding, since approximately half of those examined were born of parents who were second cousins or more closely related. the results showed that congenital organic lesions of the eye were verymore » signiiicantly higher among children of first cousins than among the outbred children. So great was the increase, it suggested that the eye is more subject to disability mediated by recessive genes than are other organsystems. Loss of distani visual acuity in which no organic lesion was revealed by ophthalmoscopy was attributed to refractive errors; about 80% of the children with 20/70 visual acuity or worse in one or both eyes appeared to have myopia. The role of inheritance was iraplicated by the increasing frequency of the defects as the degree of inbreeding increased, and by the tendency for cases to aggregate in families. Effects of the environment during intra-uterine life, or soon thereafter, were suggested by thc relationship of season of birth to the risk of visual aeuity loss later in childhood and, independently, by the association of birth weight less than 2500 grams with an increased risk of such loss. No association was found between visual acuity loss and socio-economic status physical, neurological, or dental development, or the history or presence of illness. The age-specific prevalence rates were consistently higher in Nagasaki than in Hiroshima. The accumulated evidence suggests that myopia is attributable to a developmental flow in the sclera.« less

Vitreoretinal surgery without schisis cavity excision for the management of juvenile X linked retinoschisis.

PubMed

García-Arumí, J; Corcóstegui, I A; Navarro, R; Zapata, M A; Berrocal, M H

2008-11-01

Juvenile X linked retinoschisis (XLRS) is a congenital X linked recessive retinal disorder characterised by cystic maculopathy and peripheral schisis. This study presents the case of an 8-month-old boy with a documented positive family history of XLRS, with a large retinoschisis cavity affecting the macula, first in the left eye and 1 year later in the right eye. The patient underwent pars plana vitrectomy in both eyes using 23-G instruments, posterior hyaloid dissection, a small retinotomy, fluid drainage with a 42-G cannula, infrared diode laser and silicone oil as internal tamponade. The anatomical and functional outcomes at 3 years following the first surgery are described. To the authors' knowledge, there is no previously reported experience with this technique in patients with XLRS.

Visualization of nigrosome 1 and its loss in PD

PubMed Central

Schwarz, Stefan T.; Pitiot, Alain; Stephenson, Mary C.; Lowe, James; Bajaj, Nin; Bowtell, Richard W.; Auer, Dorothee P.; Gowland, Penny A.

2013-01-01

Objective: This study assessed whether high-resolution 7 T MRI allowed direct in vivo visualization of nigrosomes, substructures of the substantia nigra pars compacta (SNpc) undergoing the greatest and earliest dopaminergic cell loss in Parkinson disease (PD), and whether any disease-specific changes could be detected in patients with PD. Methods: Postmortem (PM) midbrains, 2 from healthy controls (HCs) and 1 from a patient with PD, were scanned with high-resolution T2*-weighted MRI scans, sectioned, and stained for iron and neuromelanin (Perl), TH, and calbindin. To confirm the identification of nigrosomes in vivo on 7 T T2*-weighted scans, we assessed colocalization with neuromelanin-sensitive T1-weighted scans. We then assessed the ability to depict PD pathology on in vivo T2*-weighted scans by comparing data from 10 patients with PD and 8 age- and sex-matched HCs. Results: A hyperintense, ovoid area within the dorsolateral border of the otherwise hypointense SNpc was identified in the HC brains on in vivo and PM T2*-weighted MRI. Location, size, shape, and staining characteristics conform to nigrosome 1. Blinded assessment by 2 neuroradiologists showed consistent bilateral absence of this nigrosome feature in all 10 patients with PD, and bilateral presence in 7/8 HC. Conclusions: In vivo and PM MRI with histologic correlation demonstrates that high-resolution 7 T MRI can directly visualize nigrosome 1. The absence of nigrosome 1 in the SNpc on MRI scans might prove useful in developing a neuroimaging diagnostic test for PD. PMID:23843466

Visual and x-ray inspection characteristics of eutectic and lead free assemblies

NASA Technical Reports Server (NTRS)

Ghaffarian, R.

2003-01-01

For high reliability applications, visual inspection has been the key technique for most conventional electronic package assemblies. Now, the use of x-ray technique has become an additional inspection requirement for quality control and detection of unique defects due to manufacturing of advanced electronic array packages such as ball grid array (BGAs) and chip scale packages (CSPs).

Unique Variants in OPN1LW Cause Both Syndromic and Nonsyndromic X-Linked High Myopia Mapped to MYP1.

PubMed

Li, Jiali; Gao, Bei; Guan, Liping; Xiao, Xueshan; Zhang, Jianguo; Li, Shiqiang; Jiang, Hui; Jia, Xiaoyun; Yang, Jianhua; Guo, Xiangming; Yin, Ye; Wang, Jun; Zhang, Qingjiong

2015-06-01

MYP1 is a locus for X-linked syndromic and nonsyndromic high myopia. Recently, unique haplotypes in OPN1LW were found to be responsible for X-linked syndromic high myopia mapped to MYP1. The current study is to test if such variants in OPN1LW are also responsible for X-linked nonsyndromic high myopia mapped to MYP1. The proband of the family previously mapped to MYP1 was initially analyzed using whole-exome sequencing and whole-genome sequencing. Additional probands with early-onset high myopia were analyzed using whole-exome sequencing. Variants in OPN1LW were selected and confirmed by Sanger sequencing. Long-range and second PCR were used to determine the haplotype and the first gene of the red-green gene array. Candidate variants were further validated in family members and controls. The unique LVAVA haplotype in OPN1LW was detected in the family with X-linked nonsyndromic high myopia mapped to MYP1. In addition, this haplotype and a novel frameshift mutation (c.617_620dup, p.Phe208Argfs*51) in OPN1LW were detected in two other families with X-linked high myopia. The unique haplotype cosegregated with high myopia in the two families, with a maximum LOD score of 3.34 and 2.31 at θ = 0. OPN1LW with the variants in these families was the first gene in the red-green gene array and was not present in 247 male controls. Reevaluation of the clinical data in both families with the unique haplotype suggested nonsyndromic high myopia. Our study confirms the findings that unique variants in OPN1LW are responsible for both syndromic and nonsyndromic X-linked high myopia mapped to MYP1.

X-linked juvenile retinoschisis (XLRS): a review of genotype-phenotype relationships.

PubMed

Kim, David Y; Mukai, Shizuo

2013-01-01

X-linked juvenile retinoschisis (XLRS) is one of the most common genetic causes of juvenile progressive retinal-vitreal degeneration in males. To date, more than 196 different mutations of the RS1 gene have been associated with XLRS. The mutation spectrum is large and the phenotype variable. This review will focus on the clinical features of XLRS and examine the relationship between phenotype and genotype.

Concurrent audio-visual feedback for supporting drivers at intersections: A study using two linked driving simulators.

PubMed

Houtenbos, M; de Winter, J C F; Hale, A R; Wieringa, P A; Hagenzieker, M P

2017-04-01

A large portion of road traffic crashes occur at intersections for the reason that drivers lack necessary visual information. This research examined the effects of an audio-visual display that provides real-time sonification and visualization of the speed and direction of another car approaching the crossroads on an intersecting road. The location of red blinking lights (left vs. right on the speedometer) and the lateral input direction of beeps (left vs. right ear in headphones) corresponded to the direction from where the other car approached, and the blink and beep rates were a function of the approaching car's speed. Two driving simulators were linked so that the participant and the experimenter drove in the same virtual world. Participants (N = 25) completed four sessions (two with the audio-visual display on, two with the audio-visual display off), each session consisting of 22 intersections at which the experimenter approached from the left or right and either maintained speed or slowed down. Compared to driving with the display off, the audio-visual display resulted in enhanced traffic efficiency (i.e., greater mean speed, less coasting) while not compromising safety (i.e., the time gap between the two vehicles was equivalent). A post-experiment questionnaire showed that the beeps were regarded as more useful than the lights. It is argued that the audio-visual display is a promising means of supporting drivers until fully automated driving is technically feasible. Copyright © 2016. Published by Elsevier Ltd.

Molecular patterns of X chromosome-linked color vision genes among 134 menof European ancestry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drummond-Borg, M.; Deeb, S.S.; Motulsky, A.G.

1989-02-01

The authors used Southern blot hybridization to study X chromosome-linked color vision genes encoding the apoproteins of red and green visual pigments in 134 unselected Caucasian men. One hundred and thirteen individuals (84.3%) had a normal arrangement of their color vision pigment genes. All had one red pigment gene; the number of green pigment genes ranged from one to five with a mode of two. The frequency of molecular genotypes indicative of normal color vision (84.3%) was significantly lower than had been observed in previous studies of color vision phenotypes. Color vision defects can be due to deletions of redmore » or green pigment genes or due to formation of hybrid genes comprising portions of both red and green pigment genes. Characteristic anomalous patterns were seen in 15 (11.2%) individuals: 7 (5.2%) had patterns characteristic of deuteranomaly, 2 (1.5%) had patterns characteristic of deuteranopia, and 6 (4.5%) had protan patterns. Previously undescribed hybrid gene patterns consisting of both green and red pigment gene fragments in addition to normal red and green genes were observed in another 6 individuals (4.5%). Thus, DNA testing detected anomalous color vision pigment genes at a higher frequency than expected from phenotypic color vision tests.« less

Visual speech alters the discrimination and identification of non-intact auditory speech in children with hearing loss.

PubMed

Jerger, Susan; Damian, Markus F; McAlpine, Rachel P; Abdi, Hervé

2017-03-01

Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development. Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/-B/aa or/-B/az). The items started with an easy-to-speechread/B/or difficult-to-speechread/G/onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/-B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same-as opposed to different-responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g.,/-B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz-as opposed to az- responses in the audiovisual than auditory mode. Performance in the audiovisual mode showed more same

Visual Speech Alters the Discrimination and Identification of Non-Intact Auditory Speech in Children with Hearing Loss

PubMed Central

Jerger, Susan; Damian, Markus F.; McAlpine, Rachel P.; Abdi, Hervé

2017-01-01

Objectives Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development. Methods Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/–B/aa or /–B/az). The items started with an easy-to-speechread /B/ or difficult-to-speechread /G/ onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/–B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same—as opposed to different—responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g., /–B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz—as opposed to az— responses in the audiovisual than auditory mode. Results

Braille Reading Accuracy of Students Who Are Visually Impaired: The Effects of Gender, Age at Vision Loss, and Level of Education

ERIC Educational Resources Information Center

Argyropoulos, Vassilis; Papadimitriou, Vassilios

2015-01-01

Introduction: The present study assesses the performance of students who are visually impaired (that is, those who are blind or have low vision) in braille reading accuracy and examines potential correlations among the error categories on the basis of gender, age at loss of vision, and level of education. Methods: Twenty-one visually impaired…

The RetroX auditory implant for high-frequency hearing loss.

PubMed

Garin, P; Genard, F; Galle, C; Jamart, J

2004-07-01

The objective of this study was to analyze the subjective satisfaction and measure the hearing gain provided by the RetroX (Auric GmbH, Rheine, Germany), an auditory implant of the external ear. We conducted a retrospective case review. We conducted this study at a tertiary referral center at a university hospital. We studied 10 adults with high-frequency sensori-neural hearing loss (ski-slope audiogram). The RetroX consists of an electronic unit sited in the postaural sulcus connected to a titanium tube implanted under the auricle between the sulcus and the entrance of the external auditory canal. Implanting requires only minor surgery under local anesthesia. Main outcome measures were a satisfaction questionnaire, pure-tone audiometry in quiet, speech audiometry in quiet, speech audiometry in noise, and azimuth audiometry (hearing threshold in function of sound source location within the horizontal plane at ear level). : Subjectively, all 10 patients are satisfied or even extremely satisfied with the hearing improvement provided by the RetroX. They wear the implant daily, from morning to evening. We observe a statistically significant improvement of pure-tone thresholds at 1, 2, and 4 kHz. In quiet, the speech reception threshold improves by 9 dB. Speech audiometry in noise shows that intelligibility improves by 26% for a signal-to-noise ratio of -5 dB, by 18% for a signal-to-noise ratio of 0 dB, and by 13% for a signal-to-noise ratio of +5 dB. Localization audiometry indicates that the skull masks sound contralateral to the implanted ear. Of the 10 patients, one had acoustic feedback and one presented with a granulomatous reaction to the foreign body that necessitated removing the implant. The RetroX auditory implant is a semi-implantable hearing aid without occlusion of the external auditory canal. It provides a new therapeutic alternative for managing high-frequency hearing loss.

Target-responsive DNAzyme cross-linked hydrogel for visual quantitative detection of lead.

PubMed

Huang, Yishun; Ma, Yanli; Chen, Yahong; Wu, Xuemeng; Fang, Luting; Zhu, Zhi; Yang, Chaoyong James

2014-11-18

Because of the severe health risks associated with lead pollution, rapid, sensitive, and portable detection of low levels of Pb(2+) in biological and environmental samples is of great importance. In this work, a Pb(2+)-responsive hydrogel was prepared using a DNAzyme and its substrate as cross-linker for rapid, sensitive, portable, and quantitative detection of Pb(2+). Gold nanoparticles (AuNPs) were first encapsulated in the hydrogel as an indicator for colorimetric analysis. In the absence of lead, the DNAzyme is inactive, and the substrate cross-linker maintains the hydrogel in the gel form. In contrast, the presence of lead activates the DNAzyme to cleave the substrate, decreasing the cross-linking density of the hydrogel and resulting in dissolution of the hydrogel and release of AuNPs for visual detection. As low as 10 nM Pb(2+) can be detected by the naked eye. Furthermore, to realize quantitative visual detection, a volumetric bar-chart chip (V-chip) was used for quantitative readout of the hydrogel system by replacing AuNPs with gold-platinum core-shell nanoparticles (Au@PtNPs). The Au@PtNPs released from the hydrogel upon target activation can efficiently catalyze the decomposition of H2O2 to generate a large volume of O2. The gas pressure moves an ink bar in the V-chip for portable visual quantitative detection of lead with a detection limit less than 5 nM. The device was able to detect lead in digested blood with excellent accuracy. The method developed can be used for portable lead quantitation in many applications. Furthermore, the method can be further extended to portable visual quantitative detection of a variety of targets by replacing the lead-responsive DNAzyme with other DNAzymes.

Visual Links: Discovery in Art and Science.

ERIC Educational Resources Information Center

Dake, Dennis M.

Some specific aspects of the process of discovery are explored as they are experienced in the visual arts and the physical sciences. Both fields use the same visual/brain processing system, and both disciplines share an imaginative and productive interest in the disciplined use of imagistic thinking. Many productive interactions between visual…

Social capital, social relationships and adults with acquired visual impairment: a nigerian perspective.

PubMed

Bassey, Emmanuel; Ellison, Caroline; Walker, Ruth

2018-01-31

This study investigates the social capital implications of vision loss among working-age adults in Nigeria. The study explores the challenges of acquiring and maintaining social relationships post-vision loss, and investigates the extent to which visual rehabilitation services support social goals. A qualitative study using a phenomenological approach was undertaken. Eight adults (18-59 years) were recruited from disability service organizations in Nigeria. Telephone interviews were recorded and transcribed, and thematic content analysis was used to analyze the data gathered in this study. Three broad themes were developed from participants' accounts of their experiences: (1) changes to relationships with friends and others; (2) finding strength in family relationships; and (3) rehabilitation and the confidence to interact. The findings indicate that the relationship between participants and their family members improved post vision impairment, enhancing bonding social capital. However, participants experienced reduced bridging and linking social capital due to diminished or broken relationships with managers, coworkers, friends, and others in the community. As social connectedness and relationships are highly valued in Nigeria's diverse society, we suggest that adults with visual impairment would significantly benefit from visual rehabilitation services placing greater emphasis on addressing the social goals of participants. Implications for Rehabilitation Visual impairment in working-age adults can strengthen family relationships (homogenous groups), creating bonding capital that is associated with access to important resources including emotional and moral support, and some financial and material resources. Visual impairment can negatively impact relationships with managers, coworkers, and others in the community (heterogeneous groups), resulting in diminished bridging and linking capital. Visual impairment can reduce access to resources such as an income

Prenatal diagnosis for a novel splice mutation of PHEX gene in a large Han Chinese family affected with X-linked hypophosphatemic rickets.

PubMed

Qiu, Guangrong; Liu, Caixia; Zhou, Jingyi; Liu, Peiyan; Wang, Jun; Jiang, Hongkun; Hou, Zhiyan; Zhao, Yanyan; Sun, Kailai; Li-Ling, Jesse

2010-06-01

X-linked hypophosphatemia (XLH) is the most common form of heritable rickets characterized by X-linked dominant inheritance, renal phosphate wasting, hypophosphatemia, and defective bone mineralization. Inactivating mutations of the PHEX gene located at Xp22.1 have been linked with this disease. Ethnic distribution of such mutations seems widespread but only a few mutations in the Chinese population have been reported to date. We report on a large Han Chinese family affected with XLH rickets, which included 13 patients from four generations. Polymerase chain reaction and direct sequencing were performed for all exons and intron-exon boundaries of the PHEX gene. The effect of nucleotide changes was analyzed using bioinformatic software. Prenatal diagnosis was performed on umbilical cord blood at the 20th gestational week. A novel G-->A splice mutation in intron 7 (c.849+1G>A) was identified in all patients from the family. As confirmed by reverse-transcription (RT)-polymerase chain reaction (PCR), the mutation has rendered loss of a normal splice donor site (c.849+1G) while activating a cryptic one at c.849+519G, which resulted in addition of 518 nucleotides to the mature RNA. Prenatal diagnosis had excluded the fetus for carrying the same mutation. A healthy boy was born later. A novel splice mutation c.849+1G>A in the PHEX gene is responsible for XLH in the studied family. Further studies may enhance our understanding of the role of this mutation in the pathogenesis of XLH.

Prenatal Correction of X-Linked Hypohidrotic Ectodermal Dysplasia.

PubMed

Schneider, Holm; Faschingbauer, Florian; Schuepbach-Mallepell, Sonia; Körber, Iris; Wohlfart, Sigrun; Dick, Angela; Wahlbuhl, Mandy; Kowalczyk-Quintas, Christine; Vigolo, Michele; Kirby, Neil; Tannert, Corinna; Rompel, Oliver; Rascher, Wolfgang; Beckmann, Matthias W; Schneider, Pascal

2018-04-26

Genetic deficiency of ectodysplasin A (EDA) causes X-linked hypohidrotic ectodermal dysplasia (XLHED), in which the development of sweat glands is irreversibly impaired, an condition that can lead to life-threatening hyperthermia. We observed normal development of mouse fetuses with Eda mutations after they had been exposed in utero to a recombinant protein that includes the receptor-binding domain of EDA. We administered this protein intraamniotically to two affected human twins at gestational weeks 26 and 31 and to a single affected human fetus at gestational week 26; the infants, born in week 33 (twins) and week 39 (singleton), were able to sweat normally, and XLHED-related illness had not developed by 14 to 22 months of age. (Funded by Edimer Pharmaceuticals and others.).

Development of technique for three-dimensional visualization of grain boundaries by white X-ray microbeam

NASA Astrophysics Data System (ADS)

Kajiwara, K.; Shobu, T.; Toyokawa, H.; Sato, M.

2014-04-01

A technique for three-dimensional visualization of grain boundaries was developed at BL28B2 at SPring-8. The technique uses white X-ray microbeam diffraction and a rotating slit. Three-dimensional images of small silicon single crystals filled in a plastic tube were successfully obtained using this technique for demonstration purposes. The images were consistent with those obtained by X-ray computed tomography.

A candidate gene for X-linked Ocular Albinism (OA1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bassi, M.T.; Schiaffino, V.; Rugarli, E.

1994-09-01

Ocular Albinism of the Nettleship-Fall type 1 (OA1) is the most common form of ocular albinism. It is transmitted as an X-linked recessive trait with affected males showing severe reduction of visual acuity, nystagmus, strabismus, photophobia. Ophthalmologic examination reveals foveal hypoplasia, hypopigmentation of the retina and iris translucency. Microscopic examination of melanocytes suggests that the underlying defect in OA1 is an abnormality in melanosome formation. Recently we assembled a 350 kb cosmid contig spanning the entire critical region on Xp22.3, which measures approximately 110 kb. A minimum set of cosmids was used to identify transcribed sequences using both cDNA selectionmore » and exon amplification. Two putative exons recovered by exon amplification strategy were found to be highly conserved throughout evolution and, therefore, they were used as probes for the screening of fetal and adult retina cDNA libraries. This led to the isolation of clones spanning a full-length cDNA which measures 7.6 kb. Sequence analysis revealed that the predicted protein product shows homology with syntrophines and a Xenopus laevis apical protein. The gene covers approximately 170 kb of DNA and spans the entire critical region for OA1, being deleted in two patients with contiguous gene deletion including OA1 and in one patient with isolated OA1. Therefore, this new gene represents a very strong candidate for involvement in OA1 (an alternative, but unlikely possibility to be considered is that the true OA1 gene lies within an intron of the former). Northern analysis revealed very high level of expression in retina and melanoma. Unlike most Xp22.3 genes, this gene is conserved in the mouse. We are currently performing SSCP analysis and direct sequencing of exons on DNAs from approximately 60 unrelated patients with OA1 for mutation detection.« less

The loss of residual visual memories over the passage of time.

PubMed

Mercer, Tom; Duffy, Paul

2015-01-01

There has been extensive discussion of the causes of short-term forgetting. Some accounts suggest that time plays an important role in the loss of representations, whereas other models reject this notion and explain all forgetting through interference processes. The present experiment used the recent-probes task to investigate whether residual visual information is lost over the passage of time. On each trial, three unusual target objects were displayed and followed by a probe stimulus. The task was to determine whether the probe matched any of the targets, and the next trial commenced after an intertrial interval lasting 300 ms, 3.3 s, or 8.3 s. Of critical interest were recent negative (RN) trials, on which the probe matched a target from the previous trial. These were contrasted against nonrecent negative (NRN) trials, in which the probe had not been seen in the recent past. RN trials damaged performance and slowed reaction times in comparison to NRN trials, highlighting interference. However, this interfering effect diminished as the intertrial interval was lengthened, suggesting that residual visual information is lost as time passes. This finding is difficult to reconcile with interference-based models and suggests that time plays some role in forgetting.

Sizes of X-ray radiation coherent domains in thin SmS films and their visualization

NASA Astrophysics Data System (ADS)

Sharenkova, N. V.; Kaminskii, V. V.; Petrov, S. N.

2011-09-01

The size of X-ray radiation coherent domains (250 ± 20 Å) is determined in a thin polycrystalline SmS film using X-ray diffraction patterns (θ-2θ scanning, DRON-2 diffractometer, Cu K α radiation) and the Selyakov-Scherrer formula with allowance for the effect of microstrains. An image of this film is taken with a transmission electron microscope, and regions with a characteristic size of 240 Å are clearly visible in it. It is concluded that X-ray radiation coherent domains are visualized.

Optical Coherence Tomography Evolution in a Case of X-Linked Juvenile Retinoschisis: 15 Years of Follow-Up.

PubMed

Chatziralli, Irini; Theodossiadis, George; Brouzas, Dimitrios; Emfietzoglou, Ioannis; Theodossiadis, Panagiotis

2017-01-01

We present the evolution of X-linked juvenile retinoschisis (XLRS) in a male patient using optical coherence tomography (OCT) with a long-term follow-up time of 15 years. A 10-year-old male patient presented at the Medical Retina Department of our hospital complaining for blurred vision in both eyes. At the initial presentation in 2001, his best corrected visual acuity (BCVA) was 6/12 in both eyes on the Snellen chart. Based on clinical and OCT findings, the diagnosis of XLRS was made, and it was confirmed by genetic testing. No treatment was performed, but the patient was regularly examined. His BCVA and OCT findings remained relatively stable from 2001 to 2012, when BCVA decreased to 6/18 and 6/24 in the right and left eye, respectively. In 2016, his BCVA was 6/24 and 6/36 in right and left eye, respectively, while OCT depicted significant macular thinning, accompanied by irregularities of the foveal contour in both eyes. Patients with XLRS should be monitored regularly to evaluate the progression of the disease and manage the potential complications.

Characterization of the Genetic Program Linked to the Development of Atrial Fibrillation in CREM-IbΔC-X Mice.

PubMed

Seidl, Matthias D; Stein, Juliane; Hamer, Sabine; Pluteanu, Florentina; Scholz, Beatrix; Wardelmann, Eva; Huge, Andreas; Witten, Anika; Stoll, Monika; Hammer, Elke; Völker, Uwe; Müller, Frank U

2017-08-01

Reduced expression of genes regulated by the transcription factors CREB/CREM (cAMP response element-binding protein/modulator) is linked to atrial fibrillation (AF) susceptibility in patients. Cardiomyocyte-directed expression of the inhibitory CREM isoform CREM-IbΔC-X in transgenic mice (TG) leads to spontaneous-onset AF preceded by atrial dilatation and conduction abnormalities. Here, we characterized the altered gene program linked to atrial remodeling and development of AF in CREM-TG mice. Atria of young (TGy, before AF onset) and old (TGo, after AF onset) TG mice were investigated by mRNA microarray profiling in comparison with age-matched wild-type controls (WTy/WTo). Proteomic alterations were profiled in young mice (8 TGy versus 8 WTy). Annotation of differentially expressed genes revealed distinct differences in biological functions and pathways before and after onset of AF. Alterations in metabolic pathways, some linked to altered peroxisome proliferator-activated receptor signaling, muscle contraction, and ion transport were already present in TGy. Electron microscopy revealed significant loss of sarcomeres and mitochondria and increased collagen and glycogen deposition in TG mice. Alterations in electrophysiological pathways became prominent in TGo, concomitant with altered gene expression of K + -channel subunits and ion channel modulators, relevant in human AF. The most prominent alterations of the gene program linked to CREM-induced atrial remodeling were identified in the expression of genes related to structure, metabolism, contractility, and electric activity regulation, suggesting that CREM transgenic mice are a valuable experimental model for human AF pathophysiology. © 2017 American Heart Association, Inc.

Genome instability in Novel Lolium multiflorum x L. arundinaceum hybrids

USDA-ARS?s Scientific Manuscript database

We have identified a method whereby Lolium multiflorum (Lm) or L. arundinaceum (Fa) genomes are preferentially eliminated through a mitotic loss behavior in interspecific Lm x Fa F1 hybrids,generating either dihaploid Lm lines or Fa lines. The genome instability has been visualized phenotypically an...

SPECT in patients with cortical visual loss.

PubMed

Silverman, I E; Galetta, S L; Gray, L G; Moster, M; Atlas, S W; Maurer, A H; Alavi, A

1993-09-01

Single-photon emission computed tomography (SPECT) with 99mTc-hexamethylpropyleneamine oxime (HMPAO) was used to investigate changes in cerebral blood flow in seven patients with cortical visual impairment. Traumatic brain injury (TBI) was the cause of cortical damage in two patients, cerebral ischemia in two patients and carbon monoxide (CO) poisoning, status epilepticus and Alzheimer's Disease (AD) each in three separate patients. The SPECT scans of the seven patients were compared to T2-weighted magnetic resonance image (MRI) scans of the brain to determine the correlation between functional and anatomical findings. In six of the seven patients, the qualitative interpretation of the SPECT studies supported the clinical findings (i.e., the visual field defect) by revealing altered regional cerebral blood flow (rCBF) in the appropriate regions of the visual pathway. MR scans in all of the patients, on the other hand, were either normal or disclosed smaller lesions than those detected by SPECT. We conclude that SPECT may reveal altered rCBF in patients with cortical visual impairment of various etiologies, even when MRI studies are normal or nondiagnostic.

Rebound macular edema following oral acetazolamide therapy for juvenile X-linked retinoschisis in an Italian family.

PubMed

Galantuomo, Maria Silvana; Fossarello, Maurizio; Cuccu, Alberto; Farci, Roberta; Preising, Markus N; Lorenz, Birgit; Napoli, Pietro Emanuele

2016-01-01

Juvenile X-linked retinoschisis (RS1, OMIM: 312700) is a hereditary vitreoretinal dystrophy characterized by bilateral foveal schisis and, in half of the patients, splitting through the nerve fiber layer in the peripheral retina. In the first decade of life, patients usually develop a decrease in visual acuity. Long-term visual outcomes can be poor due to the limited number of known successful treatments. The purposes of this study were to present, for the first time, a p.Arg197Cys missense mutation in the RS1 gene (OMIM: 300839) in a four-generation Italian family with RS1 and to examine the clinical response to the treatment with acetazolamide tablets alone or in combination with dorzolamide eye drops as assessed by spectral-domain optical coherence tomography (SD-OCT). Eleven individuals, including two brothers with RS1 (patients 1 and 2), underwent a full medical history examination and a comprehensive ocular assessment that involved SD-OCT, fluorescein angiography, electroretinography and DNA analysis. Each RS1 patient received oral acetazolamide (375 mg daily) during the first three months. Thereafter, patient 1 continued only with dorzolamide eyedrops three times a day for a period of three months, while patient 2 spontaneously stopped both medications. Sequence analysis of the RS1 gene identified a hemizygous c.589C>T (p.Arg197Cys) missense mutation in exon 6, which has not been previously reported in an Italian family. A different response to the medical therapy was observed in the four eyes of the two affected brothers hemizygous for this abnormality. Of note, after acetazolamide interruption, a rebound effect on cystoid macular edema reduced the beneficial effects of the initial therapy for RS1 from p.Arg197Cys mutation. Indeed, a minimal rebound effect on cystoid macular edema, and an improvement in visual acuity, was observed in patient 1 during the six months of treatment. Conversely, in patient 2, an initial improvement in cystoid macular edema was

Evidence for increased SOX3 dosage as a risk factor for X-linked hypopituitarism and neural tube defects.

PubMed

Bauters, Marijke; Frints, Suzanna G; Van Esch, Hilde; Spruijt, Liesbeth; Baldewijns, Marcella M; de Die-Smulders, Christine E M; Fryns, Jean-Pierre; Marynen, Peter; Froyen, Guy

2014-08-01

Genomic duplications of varying lengths at Xq26-q27 involving SOX3 have been described in families with X-linked hypopituitarism. Using array-CGH we detected a 1.1 Mb microduplication at Xq27 in a large family with three males suffering from X-linked hypopituitarism. The duplication was mapped from 138.7 to 139.8 Mb, harboring only two annotated genes, SOX3 and ATP11C, and was shown to be a direct tandem copy number gain. Unexpectedly, the microduplication did not fully segregate with the disease in this family suggesting that SOX3 duplications have variable penetrance for X-linked hypopituitarism. In the same family, a female fetus presenting with a neural tube defect was also shown to carry the SOX3 copy number gain. Since we also demonstrated increased SOX3 mRNA levels in amnion cells derived from an unrelated t(X;22)(q27;q11) female fetus with spina bifida, we propose that increased levels of SOX3 could be a risk factor for neural tube defects. © 2014 Wiley Periodicals, Inc.

Exponential decline of deep-sea ecosystem functioning linked to benthic biodiversity loss.

PubMed

Danovaro, Roberto; Gambi, Cristina; Dell'Anno, Antonio; Corinaldesi, Cinzia; Fraschetti, Simonetta; Vanreusel, Ann; Vincx, Magda; Gooday, Andrew J

2008-01-08

Recent investigations suggest that biodiversity loss might impair the functioning and sustainability of ecosystems. Although deep-sea ecosystems are the most extensive on Earth, represent the largest reservoir of biomass, and host a large proportion of undiscovered biodiversity, the data needed to evaluate the consequences of biodiversity loss on the ocean floor are completely lacking. Here, we present a global-scale study based on 116 deep-sea sites that relates benthic biodiversity to several independent indicators of ecosystem functioning and efficiency. We show that deep-sea ecosystem functioning is exponentially related to deep-sea biodiversity and that ecosystem efficiency is also exponentially linked to functional biodiversity. These results suggest that a higher biodiversity supports higher rates of ecosystem processes and an increased efficiency with which these processes are performed. The exponential relationships presented here, being consistent across a wide range of deep-sea ecosystems, suggest that mutually positive functional interactions (ecological facilitation) can be common in the largest biome of our biosphere. Our results suggest that a biodiversity loss in deep-sea ecosystems might be associated with exponential reductions of their functions. Because the deep sea plays a key role in ecological and biogeochemical processes at a global scale, this study provides scientific evidence that the conservation of deep-sea biodiversity is a priority for a sustainable functioning of the worlds' oceans.

The risk of pedestrian collisions with peripheral visual field loss.

PubMed

Peli, Eli; Apfelbaum, Henry; Berson, Eliot L; Goldstein, Robert B

2016-12-01

Patients with peripheral field loss complain of colliding with other pedestrians in open-space environments such as shopping malls. Field expansion devices (e.g., prisms) can create artificial peripheral islands of vision. We investigated the visual angle at which these islands can be most effective for avoiding pedestrian collisions, by modeling the collision risk density as a function of bearing angle of pedestrians relative to the patient. Pedestrians at all possible locations were assumed to be moving in all directions with equal probability within a reasonable range of walking speeds. The risk density was found to be highly anisotropic. It peaked at ≈45° eccentricity. Increasing pedestrian speed range shifted the risk to higher eccentricities. The risk density is independent of time to collision. The model results were compared to the binocular residual peripheral island locations of 42 patients with forms of retinitis pigmentosa. The natural residual island prevalence also peaked nasally at about 45° but temporally at about 75°. This asymmetry resulted in a complementary coverage of the binocular field of view. Natural residual binocular island eccentricities seem well matched to the collision-risk density function, optimizing detection of other walking pedestrians (nasally) and of faster hazards (temporally). Field expansion prism devices will be most effective if they can create artificial peripheral islands at about 45° eccentricities. The collision risk and residual island findings raise interesting questions about normal visual development.

Loss of P2X7 receptor function dampens whole body energy expenditure and fatty acid oxidation.

PubMed

Giacovazzo, Giacomo; Apolloni, Savina; Coccurello, Roberto

2018-05-12

The established role of ATP-responsive P2X7 receptor in inflammatory, neurodegenerative, and immune diseases is now expanding to include several aspects of metabolic dysregulation. Indeed, P2X7 receptors are involved in β cell function, insulin secretion, and liability to diabetes, and loss of P2X7 function may increase the risk of hepatic steatosis and disrupt adipogenesis. Recently, body weight gain, abnormal lipid accumulation, adipocyte hyperplasia, increased fat mass, and ectopic fat distribution have been found in P2X7 KO mice. Here, we hypothesized that such clinical picture of dysregulated lipid metabolism might be the result of altered in vivo energy metabolism. By indirect calorimetry, we assessed 24 h of energy expenditure (EE) and respiratory exchange ratio (RER) as quotient of carbohydrate to fat oxidation in P2X7 KO mice. Moreover, we assessed the same parameters in aged-matched WT counterparts that underwent a 7-day treatment with the P2X7 antagonist A804598. We found that loss of P2X7 function elicits a severe decrease of EE that was less pronounced in A804598-treated mice. In parallel, P2X7KO mice show a drastic increase of RER, thus indicating the occurrence of a greater ratio of carbohydrate to fat oxidation. Decreased EE and fat oxidation is predictive of body weight gain, which was here confirmed. Taken together, our data provide evidence that P2X7 loss of function produces defective energy homeostasis that, together with disrupted adipogenesis, might help to explain accumulation of adipose tissue and contribute to disclose the potential role of P2X7 in metabolic diseases.

How does visual language affect crossmodal plasticity and cochlear implant success?

PubMed Central

Lyness, C.R.; Woll, B.; Campbell, R.; Cardin, V.

2013-01-01

Cochlear implants (CI) are the most successful intervention for ameliorating hearing loss in severely or profoundly deaf children. Despite this, educational performance in children with CI continues to lag behind their hearing peers. From animal models and human neuroimaging studies it has been proposed the integrative functions of auditory cortex are compromised by crossmodal plasticity. This has been argued to result partly from the use of a visual language. Here we argue that ‘cochlear implant sensitive periods’ comprise both auditory and language sensitive periods, and thus cannot be fully described with animal models. Despite prevailing assumptions, there is no evidence to link the use of a visual language to poorer CI outcome. Crossmodal reorganisation of auditory cortex occurs regardless of compensatory strategies, such as sign language, used by the deaf person. In contrast, language deprivation during early sensitive periods has been repeatedly linked to poor language outcomes. Language sensitive periods have largely been ignored when considering variation in CI outcome, leading to ill-founded recommendations concerning visual language in CI habilitation. PMID:23999083

Novel PHEX nonsense mutation in a patient with X-linked hypophosphatemic rickets and review of current therapeutic regimens.

PubMed

Kienitz, T; Ventz, M; Kaminsky, E; Quinkler, M

2011-07-01

The most common form of familial hypophosphatemic rickets is X-linked. PHEX has been identified as the gene defective in this phosphate wasting disorder leading to decreased renal phosphate reabsorption, hypophosphatemia and inappropriate concentrations of 1,25-dihydroxyvitamin D in regard to hypophosphatemia. Clinical manifestation are skeletal deformities, short stature, osteomalacia, dental abscesses, bone pain, and loss of hearing. We report 3 cases of hypophosphatemic rickets with genetic mutational analysis of the PHEX gene. In 1 male patient an unknown nonsense mutation was found in exon 7, codon 245 (c.735T>G, Tyr245Term, Y245X). In both female patients known mutations were found: c.682delTC (exon 6, codon 228) and c.1952G>C (exon 19, codon 651, R651P). Age at diagnosis ranged from early childhood to the age of 35 years. Clinical complications were hip replacement in 1 patient, mild nephrocalcinosis in 2 patients and loss of hearing in 1 patient. All 3 patients have been treated with phosphate supplements and receive 1,25-dihydroxyvitamin D. Under this regimen all patients show stable biochemical markers with slight hyperparathyreoidism. In all patients at least one family member is affected by rickets, as well. We report a novel nonsense mutation of PHEX that has not been identified so far. The recent discovery of FGF23 and MEPE has changed our understanding of the kidney-bone metabolism, but also raises concerns about the efficacy of current therapeutic regimens that are reviewed in this context. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

Gastrointestinal Manifestations in X-linked Agammaglobulinemia

PubMed Central

Barmettler, Sara; Otani, Iris M.; Minhas, Jasmit; Abraham, Roshini S.; Chang, Yenhui; Dorsey, Morna J.; Ballas, Zuhair K.; Bonilla, Francisco A.; Ochs, Hans D.; Walter, Jolan E.

2017-01-01

Purpose X-linked agammaglobulinemia is a primary humoral immunodeficiency characterized by hypogammaglobulinemia and increased susceptibility to infection. Although there is increased awareness of autoimmune and inflammatory complications in XLA, the spectrum of gastrointestinal manifestations has not previously been fully explored. Methods We present a case report of a family with two affected patients with XLA. Given the gastrointestinal involvement of the grandfather in this family, we performed a retrospective descriptive analysis of XLA patients with reported diagnoses of GI manifestations and inflammatory bowel disease (IBD) or enteritis registered at the USIDNet, a national registry of primary immunodeficiencies. Results In this cohort of patients with XLA, we found that up to 35% had concurrent gastrointestinal manifestations, and 10% had reported diagnoses of IBD or enteritis. The most commonly reported mutations were missense, which have been associated with a less severe XLA phenotype in the literature. The severity of symptoms were wide-ranging, and management strategies were diverse and mainly experimental. Conclusions Patients with XLA may require close monitoring with particular attention for GI manifestations including IBD and infectious enteritis. Further studies are needed to improve diagnosis and management of GI conditions in XLA patients. PMID:28236219

Visualization of x-ray computer tomography using computer-generated holography

NASA Astrophysics Data System (ADS)

Daibo, Masahiro; Tayama, Norio

1998-09-01

The theory converted from x-ray projection data to the hologram directly by combining the computer tomography (CT) with the computer generated hologram (CGH), is proposed. The purpose of this study is to offer the theory for realizing the all- electronic and high-speed seeing through 3D visualization system, which is for the application to medical diagnosis and non- destructive testing. First, the CT is expressed using the pseudo- inverse matrix which is obtained by the singular value decomposition. CGH is expressed in the matrix style. Next, `projection to hologram conversion' (PTHC) matrix is calculated by the multiplication of phase matrix of CGH with pseudo-inverse matrix of the CT. Finally, the projection vector is converted to the hologram vector directly, by multiplication of the PTHC matrix with the projection vector. Incorporating holographic analog computation into CT reconstruction, it becomes possible that the calculation amount is drastically reduced. We demonstrate the CT cross section which is reconstituted by He-Ne laser in the 3D space from the real x-ray projection data acquired by x-ray television equipment, using our direct conversion technique.

Histone H2AFX Links Meiotic Chromosome Asynapsis to Prophase I Oocyte Loss in Mammals

PubMed Central

Cloutier, Jeffrey M.; Mahadevaiah, Shantha K.; ElInati, Elias; Nussenzweig, André; Tóth, Attila; Turner, James M. A.

2015-01-01

Chromosome abnormalities are common in the human population, causing germ cell loss at meiotic prophase I and infertility. The mechanisms driving this loss are unknown, but persistent meiotic DNA damage and asynapsis may be triggers. Here we investigate the contribution of these lesions to oocyte elimination in mice with chromosome abnormalities, e.g. Turner syndrome (XO) and translocations. We show that asynapsed chromosomes trigger oocyte elimination at diplonema, which is linked to the presence of phosphorylated H2AFX (γH2AFX). We find that DNA double-strand break (DSB) foci disappear on asynapsed chromosomes during pachynema, excluding persistent DNA damage as a likely cause, and demonstrating the existence in mammalian oocytes of a repair pathway for asynapsis-associated DNA DSBs. Importantly, deletion or point mutation of H2afx restores oocyte numbers in XO females to wild type (XX) levels. Unexpectedly, we find that asynapsed supernumerary chromosomes do not elicit prophase I loss, despite being enriched for γH2AFX and other checkpoint proteins. These results suggest that oocyte loss cannot be explained simply by asynapsis checkpoint models, but is related to the gene content of asynapsed chromosomes. A similar mechanistic basis for oocyte loss may operate in humans with chromosome abnormalities. PMID:26509888

Identification of Four Novel Synonymous Substitutions in the X-Linked Genes Neuroligin 3 and Neuroligin 4X in Japanese Patients with Autistic Spectrum Disorder.

PubMed

Yanagi, Kumiko; Kaname, Tadashi; Wakui, Keiko; Hashimoto, Ohiko; Fukushima, Yoshimitsu; Naritomi, Kenji

2012-01-01

Mutations in the X-linked genes neuroligin 3 (NLGN3) and neuroligin 4X (NLGN4X) were first implicated in the pathogenesis of X-linked autism in Swedish families. However, reports of mutations in these genes in autism spectrum disorder (ASD) patients from various ethnic backgrounds present conflicting results regarding the etiology of ASD, possibly because of genetic heterogeneity and/or differences in their ethnic background. Additional mutation screening study on another ethnic background could help to clarify the relevance of the genes to ASD. We scanned the entire coding regions of NLGN3 and NLGN4X in 62 Japanese patients with ASD by polymerase chain reaction-high-resolution melting curve and direct sequencing analyses. Four synonymous substitutions, one in NLGN3 and three in NLGN4X, were identified in four of the 62 patients. These substitutions were not present in 278 control X-chromosomes from unrelated Japanese individuals and were not registered in the database of Single Nucleotide Polymorphisms build 132 or in the Japanese Single Nucleotide Polymorphisms database, indicating that they were novel and specific to ASD. Though further analysis is necessary to determine the physiological and clinical importance of such substitutions, the possibility of the relevance of both synonymous and nonsynonymous substitutions with the etiology of ASD should be considered.

Identification of Four Novel Synonymous Substitutions in the X-Linked Genes Neuroligin 3 and Neuroligin 4X in Japanese Patients with Autistic Spectrum Disorder

PubMed Central

Yanagi, Kumiko; Kaname, Tadashi; Wakui, Keiko; Hashimoto, Ohiko; Fukushima, Yoshimitsu; Naritomi, Kenji

2012-01-01

Mutations in the X-linked genes neuroligin 3 (NLGN3) and neuroligin 4X (NLGN4X) were first implicated in the pathogenesis of X-linked autism in Swedish families. However, reports of mutations in these genes in autism spectrum disorder (ASD) patients from various ethnic backgrounds present conflicting results regarding the etiology of ASD, possibly because of genetic heterogeneity and/or differences in their ethnic background. Additional mutation screening study on another ethnic background could help to clarify the relevance of the genes to ASD. We scanned the entire coding regions of NLGN3 and NLGN4X in 62 Japanese patients with ASD by polymerase chain reaction-high-resolution melting curve and direct sequencing analyses. Four synonymous substitutions, one in NLGN3 and three in NLGN4X, were identified in four of the 62 patients. These substitutions were not present in 278 control X-chromosomes from unrelated Japanese individuals and were not registered in the database of Single Nucleotide Polymorphisms build 132 or in the Japanese Single Nucleotide Polymorphisms database, indicating that they were novel and specific to ASD. Though further analysis is necessary to determine the physiological and clinical importance of such substitutions, the possibility of the relevance of both synonymous and nonsynonymous substitutions with the etiology of ASD should be considered. PMID:22934180

Linking Advanced Visualization and MATLAB for the Analysis of 3D Gene Expression Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruebel, Oliver; Keranen, Soile V.E.; Biggin, Mark

Three-dimensional gene expression PointCloud data generated by the Berkeley Drosophila Transcription Network Project (BDTNP) provides quantitative information about the spatial and temporal expression of genes in early Drosophila embryos at cellular resolution. The BDTNP team visualizes and analyzes Point-Cloud data using the software application PointCloudXplore (PCX). To maximize the impact of novel, complex data sets, such as PointClouds, the data needs to be accessible to biologists and comprehensible to developers of analysis functions. We address this challenge by linking PCX and Matlab via a dedicated interface, thereby providing biologists seamless access to advanced data analysis functions and giving bioinformatics researchersmore » the opportunity to integrate their analysis directly into the visualization application. To demonstrate the usefulness of this approach, we computationally model parts of the expression pattern of the gene even skipped using a genetic algorithm implemented in Matlab and integrated into PCX via our Matlab interface.« less

Relation of Response to Treatment with Dorzolamide in X-linked Retinoschisis to the Mechanism of Functional Loss in Retinoschisin

PubMed Central

Walia, Saloni; Fishman, Gerald A.; Molday, Robert S.; Dyka, Frank M.; Kumar, Nalin M.; Ehlinger, Mary A.; Stone, Edwin M.

2009-01-01

PURPOSE To determine if a positive response of macular cysts to treatment with dorzolamide eye drops in patients with juvenile X-linked retinoschisis (XLRS) can occur with mutations which result in different types of retinoschisin protein dysfunction. DESIGN Retrospective case series METHODS Thirteen eyes of 7 patients seen at the University of Illinois at Chicago with a known diagnosis of XLRS were included. Each patient had prior or was on current treatment with topical dorzolamide. One patient from each family was screened for a genetic mutation. Using the method of cell transfection and protein preparation, the mutation in each patient was further analyzed and categorized into three groups: 1. total absence of retinoschisin protein secretion, 2. decreased expression of the secreted protein or 3. secretion of a non-functional protein. The response to dorzolamide was observed using optical coherence tomography. RESULTS Significant improvement in the foveal zone thickness was observed with the use of dorzolamide in 3 of 4 patients with absence of protein secretion, in 2 patients with a lack of protein expression and in 1 patient with a non-functional protein secretion. CONCLUSION This study shows that the response of macular cysts to dorzolamide in patients with XLRS may be observed independent of the mechanism responsible for retinoschisin protein dysfunction. Hence, treatment with dorzolamide may be effective in patients with different mechanisms of dysfunction in retinoschisin. PMID:18834580

Visual stimuli and written production of deaf signers.

PubMed

Jacinto, Laís Alves; Ribeiro, Karen Barros; Soares, Aparecido José Couto; Cárnio, Maria Silvia

2012-01-01

To verify the interference of visual stimuli in written production of deaf signers with no complaints regarding reading and writing. The research group consisted of 12 students with education between the 4th and 5th grade of elementary school, with severe or profound sensorineural hearing loss, users of LIBRAS and with alphabetical writing level. The evaluation was performed with pictures in a logical sequence and an action picture. The analysis used the communicative competence criteria. There were no differences in the writing production of the subjects for both stimuli. In all texts there was no title and punctuation, verbs were in the infinitive mode, there was lack of cohesive links and inclusion of created words. The different visual stimuli did not affect the production of texts.

Visual analytics for semantic queries of TerraSAR-X image content

NASA Astrophysics Data System (ADS)

Espinoza-Molina, Daniela; Alonso, Kevin; Datcu, Mihai

2015-10-01

With the continuous image product acquisition of satellite missions, the size of the image archives is considerably increasing every day as well as the variety and complexity of their content, surpassing the end-user capacity to analyse and exploit them. Advances in the image retrieval field have contributed to the development of tools for interactive exploration and extraction of the images from huge archives using different parameters like metadata, key-words, and basic image descriptors. Even though we count on more powerful tools for automated image retrieval and data analysis, we still face the problem of understanding and analyzing the results. Thus, a systematic computational analysis of these results is required in order to provide to the end-user a summary of the archive content in comprehensible terms. In this context, visual analytics combines automated analysis with interactive visualizations analysis techniques for an effective understanding, reasoning and decision making on the basis of very large and complex datasets. Moreover, currently several researches are focused on associating the content of the images with semantic definitions for describing the data in a format to be easily understood by the end-user. In this paper, we present our approach for computing visual analytics and semantically querying the TerraSAR-X archive. Our approach is mainly composed of four steps: 1) the generation of a data model that explains the information contained in a TerraSAR-X product. The model is formed by primitive descriptors and metadata entries, 2) the storage of this model in a database system, 3) the semantic definition of the image content based on machine learning algorithms and relevance feedback, and 4) querying the image archive using semantic descriptors as query parameters and computing the statistical analysis of the query results. The experimental results shows that with the help of visual analytics and semantic definitions we are able to explain

Browsing and Visualization of Linked Environmental Data

NASA Astrophysics Data System (ADS)

Nikolaou, Charalampos; Kyzirakos, Kostis; Bereta, Konstantina; Dogani, Kallirroi; Koubarakis, Manolis

2014-05-01

RDF store Strabon (http://www.strabon.di.uoa.gr/) which, apart from querying geospatial information, can also be used to query both the valid time of a triple and user-defined time. With the aim of filling the aforementioned gaps and going beyond data exploration to map creation and sharing, we have designed and developed SexTant (http://sextant.di.uoa.gr/). SexTant can be used to produce thematic maps by layering spatiotemporal information which exists in a number of data sources ranging from standard SPARQL endpoints, to SPARQL endpoints following the standard GeoSPARQL defined by the Open Geospatial Consortium (OGC) for the modelling and querying of geospatial information, and other well-adopted geospatial file formats, such as KML and GeoJSON. In this work, we pick some real use cases from the environment domain to showcase the usefulness of SexTant to the environmental studies of a domain expert by presenting its browsing and visualization capabilities using a number of environmental datasets that we have published as linked data and also other geospatial data sources publicly available on the Web, such as KML files.

Sporadic Visual Acuity Loss in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT)

PubMed Central

Kim, Benjamin J.; Ying, Gui-Shuang; Huang, Jiayan; Levy, Nicole E.; Maguire, Maureen G.

2014-01-01

Purpose To evaluate transient, large visual acuity (VA) decreases, termed sporadic vision loss, during anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD). Design Cohort within a randomized clinical trial. Methods Setting Comparison of AMD Treatments Trials (CATT). Study Population 1185 CATT patients. Main Outcome Measures incidence of sporadic vision loss and odds ratio (OR) for association with patient and ocular factors. Sporadic vision loss was a decline of ≥ 15 letters from the previous visit, followed by a return at the next visit to no more than 5 letters worse than the visit before the VA loss. Results There were 143 sporadic vision loss events in 122/1185 (10.3%) patients. Mean VA at two years for those with and without sporadic vision loss was 58.5 (~20/63) and 68.4 (~20/40) letters, respectively (P < 0.001). Among patients treated pro re nata, no injection was given for 27.6% (27/98) of sporadic vision loss events. Multivariate analysis demonstrated that baseline predictors for sporadic vision loss included worse baseline VA (OR 2.92, 95%CI:1.65–5.17 for ≤ 20/200 compared with ≥ 20/40), scar (OR 2.21, 95%CI:1.22–4.01), intraretinal foveal fluid on optical coherence tomography (OR 1.80, 95%CI:1.11–2.91), and medical history of anxiety (OR 1.90, 95%CI:1.12–3.24) and syncope (OR 2.75, 95%CI:1.45–5.22). Refraction decreased the likelihood of sporadic vision loss (OR 0.62, 95%CI:0.42–0.91). Conclusions Approximately 10% of CATT patients had sporadic vision loss. Baseline predictors included AMD-related factors and factors independent of AMD. These data are relevant for clinicians in practice and those involved in clinical trials. PMID:24727261

Sporadic visual acuity loss in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

PubMed

Kim, Benjamin J; Ying, Gui-Shuang; Huang, Jiayan; Levy, Nicole E; Maguire, Maureen G

2014-07-01

To evaluate transient, large visual acuity (VA) decreases, termed sporadic vision loss, during anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD). Cohort within a randomized clinical trial. setting: Comparison of Age-Related Macular Degeneration Treatments Trials (CATT). study population: Total of 1185 CATT patients. main outcome measures: Incidence of sporadic vision loss and odds ratio (OR) for association with patient and ocular factors. Sporadic vision loss was a decline of ≥15 letters from the previous visit, followed by a return at the next visit to no more than 5 letters worse than the visit before the VA loss. There were 143 sporadic vision loss events in 122 of 1185 patients (10.3%). Mean VA at 2 years for those with and without sporadic vision loss was 58.5 (∼20/63) and 68.4 (∼20/40) letters, respectively (P < .001). Among patients treated pro re nata, no injection was given for 27.6% (27/98) of sporadic vision loss events. Multivariate analysis demonstrated that baseline predictors for sporadic vision loss included worse baseline VA (OR 2.92, 95% confidence interval [CI]:1.65-5.17 for ≤20/200 compared with ≥20/40), scar (OR 2.21, 95% CI:1.22-4.01), intraretinal foveal fluid on optical coherence tomography (OR 1.80, 95% CI:1.11-2.91), and medical history of anxiety (OR 1.90, 95% CI:1.12-3.24) and syncope (OR 2.75, 95% CI:1.45-5.22). Refraction decreased the likelihood of sporadic vision loss (OR 0.62, 95%CI: 0.42-0.91). Approximately 10% of CATT patients had sporadic vision loss. Baseline predictors included AMD-related factors and factors independent of AMD. These data are relevant for clinicians in practice and those involved in clinical trials. Copyright © 2014 Elsevier Inc. All rights reserved.

Optimizing the Galileo space communication link

NASA Technical Reports Server (NTRS)

Statman, J. I.

1994-01-01

The Galileo mission was originally designed to investigate Jupiter and its moons utilizing a high-rate, X-band (8415 MHz) communication downlink with a maximum rate of 134.4 kb/sec. However, following the failure of the high-gain antenna (HGA) to fully deploy, a completely new communication link design was established that is based on Galileo's S-band (2295 MHz), low-gain antenna (LGA). The new link relies on data compression, local and intercontinental arraying of antennas, a (14,1/4) convolutional code, a (255,M) variable-redundancy Reed-Solomon code, decoding feedback, and techniques to reprocess recorded data to greatly reduce data losses during signal acquisition. The combination of these techniques will enable return of significant science data from the mission.

MHC class 2 deficiency and X-linked agammaglobulinaemia in a consanguineous extended family.

PubMed

Broides, A; Shubinsky, G; Parvari, R; Grimbacher, B; Somech, R; Garty, B Z; Levy, J

2009-08-01

Manifestations of immunodeficiency within the same family are presumed to be the same disease. We report a consanguineous extended family where four patients have immunodeficiency, three have X-linked agammaglobulinaemia and one has major histocompatibility complex class 2 deficiency. Within one family, two rare genetic diseases with similar clinical manifestations can occur.

Dysregulation of X-linked gene expression in Klinefelter's syndrome and association with verbal cognition.

PubMed

Vawter, Marquis P; Harvey, Philip D; DeLisi, Lynn E

2007-09-05

Klinefelter's Syndrome (KS) is a chromosomal karyotype with one or more extra X chromosomes. KS individuals often show language impairment and the phenotype might be due to overexpression of genes on the extra X chromosome(s). We profiled mRNA derived from lymphoblastoid cell lines from males with documented KS and control males using the Affymetrix U133P microarray platform. There were 129 differentially expressed genes (DEGs) in KS group compared with controls after Benjamini-Hochberg false discovery adjustment. The DEGs included 14 X chromosome genes which were significantly over-represented. The Y chromosome had zero DEGs. In exploratory analysis of gene expression-cognition relationships, 12 DEGs showed significant correlation of expression with measures of verbal cognition in KS. Overexpression of one pseudoautosomal gene, GTPBP6 (GTP binding protein 6, putative) was inversely correlated with verbal IQ (r = -0.86, P < 0.001) and four other measures of verbal ability. Overexpression of XIST was found in KS compared to XY controls suggesting that silencing of many genes on the X chromosome might occur in KS similar to XX females. The microarray findings for eight DEGs were validated by quantitative PCR. The 14 X chromosome DEGs were not differentially expressed in prior studies comparing female and male brains suggesting a dysregulation profile unique to KS. Examination of X-linked DEGs, such as GTPBP6, TAF9L, and CXORF21, that show verbal cognition-gene expression correlations may establish a causal link between these genes, neurodevelopment, and language function. A screen of candidate genes may serve as biomarkers of KS for early diagnosis. Copyright 2007 Wiley-Liss, Inc.

Driving with homonymous visual field loss: a review of the literature.

PubMed

Bowers, Alex R

2016-09-01

Driving is an important rehabilitation goal for patients with homonymous field defects (HFDs); however, whether or not people with HFDs should be permitted to drive is not clear. Over the last 15 years, there has been a marked increase in the number of studies evaluating the effects of HFDs on driving performance. This review of the literature provides a much-needed summary for practitioners and researchers, addressing the following topics: regulations pertaining to driving with HFDs, self-reported driving difficulties, pass rates in on-road tests, the effects of HFDs on lane position and steering stability, the effects of HFDs on scanning and detection of potential hazards, screening for potential fitness to drive, evaluating practical fitness to drive and the efficacy of interventions to improve driving of persons with HFDs. Although there is clear evidence from on-road studies that some people with HFDs may be rated as safe to drive, others are reported to have significant deficits in skills important for safe driving, including taking a lane position too close to one side of the travel lane, unstable steering and inadequate viewing (scanning) behaviour. Driving simulator studies have provided strong evidence of a wide range in compensatory scanning abilities and detection performance, despite similar amounts of visual field loss. Conventional measurements of visual field extent (in which eye movements are not permitted) do not measure such compensatory abilities and are not predictive of on-road driving performance. Thus, there is a need to develop better tests to screen people with HFDs for visual fitness to drive. We are not yet at a point where we can predict which HFD patient is likely to be a safe driver. Therefore, it seems only fair to provide an opportunity for individualised assessments of practical fitness to drive either on the road and/or in a driving simulator. © 2016 Optometry Australia.

Driving with homonymous visual field loss: a review of the literature

PubMed Central

Bowers, Alex R.

2016-01-01

Driving is an important rehabilitation goal for patients with homonymous field defects (HFDs); however, whether or not people with HFDs should be permitted to drive is not clear. Over the last 15 years there has been a marked increase in the number of studies evaluating the effects of HFDs on driving performance. This review of the literature provides a much-needed summary for practitioners and researchers, addressing the following topics: regulations pertaining to driving with HFDs, self-reported driving difficulties, pass rates in on-road tests, the effects of HFDs on lane position and steering stability, the effects of HFDs on scanning and detection of potential hazards, screening for potential fitness to drive, evaluating practical fitness to drive, and the efficacy of interventions to improve driving of persons with HFDs. Although there is clear evidence from on-road studies that some people with HFDs may be rated as safe to drive, others are reported to have significant deficits in skills important for safe driving including taking a lane position too close to one side of the travel lane, unstable steering and inadequate viewing (scanning) behaviors. Driving simulator studies have provided strong evidence of a wide range in compensatory scanning abilities and detection performance, despite similar amounts of visual field loss. Conventional measurements of visual field extent (in which eye movements are not permitted) do not measure such compensatory abilities and are not predictive of on-road driving performance; thus, there is a need to develop better tests to screen for visual fitness to drive of people with HFDs. We are not yet at a point where we can predict which HFD patient is likely to be a safe driver. Therefore, it seems only fair to provide an opportunity for individualized assessments of practical fitness to drive either on the road and/or in a driving simulator. PMID:27535208

Severity of Visual Field Loss and Health Related Quality of Life

PubMed Central

McKean-Cowdin, Roberta; Varma, Rohit; Wu, Joanne; Hays, Ron D.; Azen, Stanley P.

2009-01-01

Purpose To examine the association between severity of visual field loss (VFL) and self-reported health-related quality of life (HRQOL) in a population-based sample. Design Population-based cross-sectional study. Methods Participants in the Los Angeles Latino Eye Study underwent a comprehensive ophthalmic examination including visual field testing using the Humphrey Automated Field Analyzer II (SITA Standard 24-2). Mean Deviation (MD) scores were used to determine severity of VFL both as a continuous variable and stratified by severity: no VFL (MD≥ − 2 decibels [dB]), mild VFL (6dBVisual Function Questionnaire (NEI-VFQ-25). Linear regression analyses and analysis of covariance were used to assess the relationship between HRQOL scores and VFL. Results Of the 5,213 participants included in this study, 18% had unilateral mild, 1.5% unilateral moderate/severe, 19% bilateral mild, and 6.5% bilateral moderate/severe VFL. Worse NEI-VFQ-25 and SF-12 HRQOL scores were associated with VFL in a linear manner. 4–5 dB differences in VFL were associated with a 5-point difference in the NEI-VFQ composite and most subscale scores. Persons with VFL had the greatest difficulty with driving activities, dependency, mental health, distance vision and peripheral vision. Conclusion HRQOL is diminished even in persons with relatively mild VFL based on MD scores. Prevention and management of persons with VFL may be important in preventing or reducing poor HRQOL related to difficulties in driving, distance and peripheral vision activities and a sense of dependency. PMID:17399676

The Association of Glaucomatous Visual Field Loss and Balance

PubMed Central

de Luna, Regina A.; Mihailovic, Aleksandra; Nguyen, Angeline M.; Friedman, David S.; Gitlin, Laura N.; Ramulu, Pradeep Y.

2017-01-01

Purpose To relate balance measures to visual field (VF) damage from glaucoma. Methods The OPAL kinematic system measured balance, as root mean square (RMS) sway, on 236 patients with suspect/diagnosed glaucoma. Balance was measured with feet shoulder width apart while standing on a firm/foam surface with eyes opened/closed (Instrumental Clinical Test of Sensory Integration and Balance [ICTSIB] conditions), and eyes open on a firm surface under feet together, semi-tandem, or tandem positions (standing balance conditions). Integrated VF (IVF) sensitivities were calculated by merging right and left eye 24-2 VF data. Results Mean age was 71 years (range, 57–93) and mean IVF sensitivity was 27.1 dB (normal = 31 dB). Lower IVF sensitivity was associated with greater RMS sway during eyes-open foam-surface testing (β = 0.23 z-score units/5 dB IVF sensitivity decrement, P = 0.001), but not during other ICTSIB conditions. Lower IVF sensitivity also was associated with greater RMS sway during feet together standing balance testing (0.10 z-score units/5 dB IVF sensitivity decrement, P = 0.049), but not during other standing balance conditions. Visual dependence of balance was lower in patients with worse IVF sensitivity (β = −21%/5 dB IVF sensitivity decrement, P < 0.001). Neither superior nor inferior IVF sensitivity consistently predicted balance measures better than measures of overall VF sensitivity. Conclusions Balance was worse in glaucoma patients with greater VF damage under foam surface testing (designed to inhibit proprioceptive contributions to balance) as well as feet-together firm-surface conditions when somatosensory inputs were available. Translational Relevance Good balance is essential to avoid unnecessary falls and patients with VF loss from glaucoma may be at higher risk of falls because of poor balance. PMID:28553562

An Ethyl-Nitrosourea-Induced Point Mutation in Phex Causes Exon Skipping, X-Linked Hypophosphatemia, and Rickets

PubMed Central

Carpinelli, Marina R.; Wicks, Ian P.; Sims, Natalie A.; O’Donnell, Kristy; Hanzinikolas, Katherine; Burt, Rachel; Foote, Simon J.; Bahlo, Melanie; Alexander, Warren S.; Hilton, Douglas J.

2002-01-01

We describe the clinical, genetic, biochemical, and molecular characterization of a mouse that arose in the first generation (G1) of a random mutagenesis screen with the chemical mutagen ethyl-nitrosourea. The mouse was observed to have skeletal abnormalities inherited with an X-linked dominant pattern of inheritance. The causative mutation, named Skeletal abnormality 1 (Ska1), was shown to be a single base pair mutation in a splice donor site immediately following exon 8 of the Phex (phosphate-regulating gene with homologies to endopeptidases located on the X-chromosome) gene. This point mutation caused skipping of exon 8 from Phex mRNA, hypophosphatemia, and features of rickets. This experimentally induced phenotype mirrors the human condition X-linked hypophosphatemia; directly confirms the role of Phex in phosphate homeostasis, normal skeletal development, and rickets; and illustrates the power of mutagenesis in exploring animal models of human disease. PMID:12414538

An ethyl-nitrosourea-induced point mutation in phex causes exon skipping, x-linked hypophosphatemia, and rickets.

PubMed

Carpinelli, Marina R; Wicks, Ian P; Sims, Natalie A; O'Donnell, Kristy; Hanzinikolas, Katherine; Burt, Rachel; Foote, Simon J; Bahlo, Melanie; Alexander, Warren S; Hilton, Douglas J

2002-11-01

We describe the clinical, genetic, biochemical, and molecular characterization of a mouse that arose in the first generation (G(1)) of a random mutagenesis screen with the chemical mutagen ethyl-nitrosourea. The mouse was observed to have skeletal abnormalities inherited with an X-linked dominant pattern of inheritance. The causative mutation, named Skeletal abnormality 1 (Ska1), was shown to be a single base pair mutation in a splice donor site immediately following exon 8 of the Phex (phosphate-regulating gene with homologies to endopeptidases located on the X-chromosome) gene. This point mutation caused skipping of exon 8 from Phex mRNA, hypophosphatemia, and features of rickets. This experimentally induced phenotype mirrors the human condition X-linked hypophosphatemia; directly confirms the role of Phex in phosphate homeostasis, normal skeletal development, and rickets; and illustrates the power of mutagenesis in exploring animal models of human disease.

Mutations in the XLRS1 gene in Thai families with X-linked juvenile retinoschisis.

PubMed

Atchaneeyasakul, La-ongsri; Trinavarat, Adisak; Pituksung, Auengporn; Jinda, Worapoj; Thongnoppakhun, Wanna; Limwongse, Chanin

2010-01-01

To identify genetic mutations of the XLRS1 gene and to describe the ocular phenotypes in two unrelated Thai patients with X-linked juvenile retinoschisis. Ophthalmic examination, including best-corrected visual acuity and fundus examination and photography, was performed in all participants. Electroretinography (ERG) and optical coherence tomography were performed when possible. All six exons of the XLRS1 gene were amplified, and mutation screening was determined by denaturing high-performance liquid chromatography and DNA sequencing. Two point mutations were identified, a novel missense mutation c.378A > G (p.D126G) in exon 5 and a reported mutation c.637C > T (p.R213W) in exon 6. The first proband with the p.D126G mutation developed vitreous hemorrhage in both eyes at age 7 months. Foveal and peripheral schisis with several inner layer holes were detected in both eyes. The second proband with the p.R213W mutation developed slightly blurred vision at age 10 years. Fundus examination showed numerous fine white dots at the macula without foveal or peripheral schisis. Electronegative ERG results were documented in both probands. A novel p.D126G mutation appeared to be associated with a severe phenotype with vitreous hemorrhage developing in infancy. Both intra- and interfamilial clinical variabilities were recognized in our patients.

Craniofacial morphometric analysis of individuals with X-linked hypohidrotic ectodermal dysplasia.

PubMed

Goodwin, Alice F; Larson, Jacinda R; Jones, Kyle B; Liberton, Denise K; Landan, Maya; Wang, Zhifeng; Boekelheide, Anne; Langham, Margaret; Mushegyan, Vagan; Oberoi, Snehlata; Brao, Rosalie; Wen, Timothy; Johnson, Ramsey; Huttner, Kenneth; Grange, Dorothy K; Spritz, Richard A; Hallgrímsson, Benedikt; Jheon, Andrew H; Klein, Ophir D

2014-09-01

Hypohidrotic ectodermal dysplasia (HED) is the most prevalent type of ectodermal dysplasia (ED). ED is an umbrella term for a group of syndromes characterized by missing or malformed ectodermal structures, including skin, hair, sweat glands, and teeth. The X-linked recessive (XL), autosomal recessive (AR), and autosomal dominant (AD) types of HED are caused by mutations in the genes encoding ectodysplasin (EDA1), EDA receptor (EDAR), or EDAR-associated death domain (EDARADD). Patients with HED have a distinctive facial appearance, yet a quantitative analysis of the HED craniofacial phenotype using advanced three-dimensional (3D) technologies has not been reported. In this study, we characterized craniofacial morphology in subjects with X-linked hypohidrotic ectodermal dysplasia (XLHED) by use of 3D imaging and geometric morphometrics (GM), a technique that uses defined landmarks to quantify size and shape in complex craniofacial morphologies. We found that the XLHED craniofacial phenotype differed significantly from controls. Patients had a smaller and shorter face with a proportionally longer chin and midface, prominent midfacial hypoplasia, a more protrusive chin and mandible, a narrower and more pointed nose, shorter philtrum, a narrower mouth, and a fuller and more rounded lower lip. Our findings refine the phenotype of XLHED and may be useful both for clinical diagnosis of XLHED and to extend understanding of the role of EDA in craniofacial development.

X-linked recessive nephrogenic diabetes insipidus: a clinico-genetic study.

PubMed

Hong, Che Ry; Kang, Hee Gyung; Choi, Hyun Jin; Cho, Min Hyun; Lee, Jung Won; Kang, Ju Hyung; Park, Hye Won; Koo, Ja Wook; Ha, Tae-Sun; Kim, Su-Yung; Il Cheong, Hae

2014-01-01

A retrospective genotype and phenotype analysis of X-linked congenital nephrogenic diabetes insipidus (NDI) was conducted on a nationwide cohort of 25 (24 male, 1 female) Korean children with AVPR2 gene mutations, comparing non-truncating and truncating mutations. In an analysis of male patients, the median age at diagnosis was 0.9 years old. At a median follow-up of 5.4 years, urinary tract dilatations were evident in 62% of patients and their median glomerular filtration rate was 72 mL/min/1.73 m2. Weights and heights were under the 3rd percentile in 22% and 33% of patients, respectively. One patient had low intelligence quotient and another developed end-stage renal disease. No statistically significant genotype-phenotype correlation was found between non-truncating and truncating mutations. One patient was female; she was analyzed separately because inactivation and mosaicism of the X chromosome may influence clinical manifestations in female patients. Current unsatisfactory long-term outcome of congenital NDI necessitates a novel therapeutic strategy.