The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Bruce H Grahn - One of the best experts on this subject based on the ideXlab platform.
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mitochondrial transcription factor a tfam gene sequencing and mitochondrial evaluation in inherited Retinal Dysplasia in miniature schnauzer dogs
Canadian Journal of Veterinary Research-revue Canadienne De Recherche Veterinaire, 2011Co-Authors: Bianca S Bauer, George W Forsyth, Lynne S Sandmeyer, Bruce H GrahnAbstract:Mitochondrial transcription factor A (Tfam) has been implicated in the pathogenesis of Retinal Dysplasia in miniature schnauzer dogs and it has been proposed that affected dogs have altered mitochondrial numbers, size, and morphology. To test these hypotheses the Tfam gene of affected and normal miniature schnauzer dogs with Retinal Dysplasia was sequenced and lymphocyte mitochondria were quantified, measured, and the morphology was compared in normal and affected dogs using transmission electron microscopy. For Tfam sequencing, retina, Retinal pigment epithelium (RPE), and whole blood samples were collected. Total RNA was isolated from the retina and RPE and reverse transcribed to make cDNA. Genomic DNA was extracted from white blood cell pellets obtained from the whole blood samples. The Tfam coding sequence, 5′ promoter region, intron1 and the 3′ non-coding sequence of normal and affected dogs were amplified using polymerase chain reaction (PCR), cloned and sequenced. For electron microscopy, lymphocytes from affected and normal dogs were photographed and the mitochondria within each cross-section were identified, quantified, and the mitochondrial area (μm2) per lymphocyte cross-section was calculated. Lastly, using a masked technique, mitochondrial morphology was compared between the 2 groups. Sequencing of the miniature schnauzer Tfam gene revealed no functional sequence variation between affected and normal dogs. Lymphocyte and mitochondrial area, mitochondrial quantification, and morphology assessment also revealed no significant difference between the 2 groups. Further investigation into other candidate genes or factors causing Retinal Dysplasia in the miniature schnauzer is warranted.
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relative quantification of white blood cell mitochondrial dna and assessment of mitochondria by use of transmission electron microscopy in english springer spaniels with and without Retinal Dysplasia
American Journal of Veterinary Research, 2010Co-Authors: Bianca S Bauer, George W Forsyth, Lynne S Sandmeyer, Bruce H GrahnAbstract:Objective—To compare relative amounts of WBC mitochondrial DNA (mtDNA; assessed via real-time PCR assay) and morphology of lymphocyte mitochondria (assessed via transmission electron microscopy [TEM]) in blood samples collected from English Springer Spaniels with and without Retinal Dysplasia. Animals—7 and 5 client-owned English Springer Spaniels (1 to 11 years old) with and without Retinal Dysplasia, respectively. Procedures—Blood samples were obtained from affected and unaffected dogs via venipuncture. Genomic DNA was extracted from WBCs of the 7 affected and 5 unaffected dogs, and relative quantification of the cytochrome c oxidase subunit 1 gene (COX1) was determined via analysis of real-time PCR results. White blood cells from 3 affected and 4 unaffected dogs were embedded in epoxide resin for TEM; cross sections were examined for lymphocytes, which were measured. The mitochondria within lymphocytes were quantified, and the mitochondrial surface area per lymphocyte cross section was calculated. A ma...
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differential mitochondrial dna and gene expression in inherited Retinal Dysplasia in miniature schnauzer dogs
Investigative Ophthalmology & Visual Science, 2006Co-Authors: Greg D Appleyard, George W Forsyth, Laura M Kiehlbauch, Kristen N Sigfrid, Heather L J Hanik, Anita Quon, Matthew E Loewen, Bruce H GrahnAbstract:PURPOSE: To investigate the molecular basis of inherited Retinal Dysplasia in miniature Schnauzers. METHODS: Retina and Retinal pigment epithelial tissues were collected from canine subjects at the age of 3 weeks. Total RNA isolated from these tissues was reverse transcribed to make representative cDNA pools that were compared for differences in gene expression by using a subtractive hybridization technique referred to as representational difference analysis (RDA). Expression differences identified by RDA were confirmed and quantified by real-time reverse-transcription PCR. Mitochondrial morphology from leukocytes and skeletal muscle of normal and affected miniature Schnauzers was examined by transmission electron microscopy. RESULTS: RDA screening of Retinal pigment epithelial cDNA identified differences in mRNA transcript coding for two mitochondrial (mt) proteins--cytochrome oxidase subunit 1 and NADH dehydrogenase subunit 6--in affected dogs. Contrary to expectations, these identified sequences did not contain mutations. Based on the implication of mt-DNA-encoded proteins by the RDA experiments we used real-time PCR to compare the relative amounts of mt-DNA template in white blood cells from normal and affected dogs. White blood cells of affected dogs contained less than 30% of the normal amount of two specific mtDNA sequences, compared with the content of the nuclear-encoded glyceraldehyde-3-phosphate dehydrogenase (GA-3-PDH) reference gene. Retina and RPE tissue from affected dogs had reduced mRNA transcript levels for the two mitochondrial genes detected in the RDA experiment. Transcript levels for another mtDNA-encoded gene as well as the nuclear-encoded mitochondrial Tfam transcription factor were reduced in these tissues in affected dogs. Mitochondria from affected dogs were reduced in number and size and were unusually electron dense. CONCLUSIONS: Reduced levels of nuclear and mitochondrial transcripts in the retina and RPE of miniature Schnauzers affected with Retinal Dysplasia suggest that the pathogenesis of the disorder may arise from a lowered energy supply to the retina and RPE.
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inherited Retinal Dysplasia and persistent hyperplastic primary vitreous in miniature schnauzer dogs
Veterinary Ophthalmology, 2004Co-Authors: Bruce H Grahn, Eric S Storey, Catherine McmillanAbstract:The objectives of this study were to define the clinical syndrome of Retinal Dysplasia and persistent primary vitreous in Miniature Schnauzer dogs and determine the etiology. We examined 106 Miniature Schnauzers using a biomicroscope and indirect ophthalmoscope. The anterior and posterior segments of affected dogs were photographed. Four enucleated eyes were examined using routine light microscopy and scanning electron microscopy. A pedigree was constructed and related dogs were test-bred to define the mode of inheritance of this syndrome. Congenital Retinal Dysplasia was confirmed in 24 of 106 related Miniature Schnauzer dogs. Physical and postmortem examinations revealed that congenital abnormalities were limited to the eyes. Biomicroscopic, indirect ophthalmoscopic, and neuro-ophthalmic examinations confirmed that some of these dogs were blind secondary to bilateral Retinal Dysplasia and detachment (nonattachment) ( n = 13), and the remainder had generalized Retinal Dysplasia ( n = 11). Fifteen of these dogs were also diagnosed with unilateral ( n = 9) or bilateral ( n = 6) persistent hyperplastic primary vitreous. Nutritional, infectious, or toxic etiologies were not evident on physical, postmortem, light microscopic, or transmitting and scanning electron microscopic examination of four affected Miniature Schnauzers. We examined the pedigree and determined that an autosomal recessive mode of inheritance was most likely. Three test-bred litters including those from affected parents, carrier and affected parents, and carrier parents confirmed this mode of inheritance. This study confirms that Retinal Dysplasia and persistent hyperplastic primary vitreous is a congenital abnormality that is inherited as an autosomal recessive condition in Miniature Schnauzers.
Beata Anna Nowakowska - One of the best experts on this subject based on the ideXlab platform.
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the smallest de novo deletion of 20q11 21 q11 23 in a girl with feeding problems Retinal Dysplasia and skeletal abnormalities
American Journal of Medical Genetics Part A, 2014Co-Authors: Renata Posmyk, Ryszard Leśniewicz, Magdalena Gogiel, Danuta Sielicka, Joris Vermeesch, Monika Chorązy, Alina Bakunowiczłazarczyk, Beata Anna NowakowskaAbstract:We report on a de novo interstitial deletion of 20q11.21–q11.23 in a 2-year-old girl with a set of dysmorphic features, cleft palate, heart defect, severe feeding problems, failure to thrive, developmental delay, preaxial polydactyly (right thumb), and Retinal Dysplasia. Interstitial microdeletions of the long arm of chromosome 20 are rare. Exclusively rare are proximal microdeletions involving 20q11–q12 region. Our patient is the fourth described so far and has the smallest deleted region 20q11.21–q11.23 of 5.7 Mb. The defined clinical phenotype of our patient is very similar to previously published cases and confirms the existence of Retinal Dysplasia and skeletal abnormalities as a part of phenotypic spectrum for deletion 20q11–q12. Description of four similar patients, including two almost identical, suggests a new distinct, phenotypicaly recognizable microdeletion syndrome associated with the loss of 20q11–q12 region. © 2014 Wiley Periodicals, Inc.
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The smallest de novo deletion of 20q11.21-q11.23 in a girl with feeding problems, Retinal Dysplasia, and skeletal abnormalities.
American journal of medical genetics. Part A, 2014Co-Authors: Renata Posmyk, Ryszard Leśniewicz, Magdalena Gogiel, Monika Chorąży, Alina Bakunowicz-Łazarczyk, Danuta Sielicka, Joris Vermeesch, Beata Anna NowakowskaAbstract:We report on a de novo interstitial deletion of 20q11.21-q11.23 in a 2-year-old girl with a set of dysmorphic features, cleft palate, heart defect, severe feeding problems, failure to thrive, developmental delay, preaxial polydactyly (right thumb), and Retinal Dysplasia. Interstitial microdeletions of the long arm of chromosome 20 are rare. Exclusively rare are proximal microdeletions involving 20q11-q12 region. Our patient is the fourth described so far and has the smallest deleted region 20q11.21-q11.23 of 5.7 Mb. The defined clinical phenotype of our patient is very similar to previously published cases and confirms the existence of Retinal Dysplasia and skeletal abnormalities as a part of phenotypic spectrum for deletion 20q11-q12. Description of four similar patients, including two almost identical, suggests a new distinct, phenotypicaly recognizable microdeletion syndrome associated with the loss of 20q11-q12 region.
R M Goodman - One of the best experts on this subject based on the ideXlab platform.
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x linked recessive primary Retinal Dysplasia clinical findings in affected males and carrier females
Clinical Genetics, 2008Co-Authors: Victor Godel, R M GoodmanAbstract:: Three unrelated families (two Jewish and one Druze) are reported, in which a total of eight males exhibited the ophthalmological findings of primary Retinal Dysplasia. Since our affects male members only have eye findings, this disorder is readily differentiated from Norrie's disease in which other parts of the nervous system are involved. The family pedigrees along with the clinical features support an X-linked recessive mode of transmission for this condition. Female carriers for this gene may show varying types of Retinal fold changes. In addition, most of these same presumed female carriers also demonstrated changes in the stroma of their irides, resulting in a gray to grayish-blue color. At present, it is not possible to state definitely whether or not this latter observation is a feature of the carrier state.
B Goldman - One of the best experts on this subject based on the ideXlab platform.
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x linked recessive primary Retinal Dysplasia is linked to the norrie disease locus
Human Molecular Genetics, 1993Co-Authors: Yehoshua Ravia, Orly Braiergoldstein, Katznelson Mariassa Batmiriam, Shai Erlich, Gad Barkai, B GoldmanAbstract:: 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.
Federico Gonzalezfernandez - One of the best experts on this subject based on the ideXlab platform.
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histogenesis of Retinal Dysplasia in trisomy 13
Diagnostic Pathology, 2007Co-Authors: Ada Chan, Reid R Heffner, Satyan Lakshminrusimha, Federico GonzalezfernandezAbstract:Background Although often associated with holoprosencephaly, little detail of the histopathology of cyclopia is available. Here, we describe the ocular findings in a case of trisomy 13 to better understand the histogenesis of the rosettes, or tubules, characteristic of the Retinal Dysplasia associated with this condition.