scholarly journals Current molecular understanding of Axenfeld–Rieger syndrome

2005 ◽  
Vol 7 (25) ◽  
pp. 1-17 ◽  
Author(s):  
Tord A. Hjalt ◽  
Elena V. Semina
Keyword(s):  
Open Angle Glaucoma ◽  
Biological Properties ◽  
Full Spectrum ◽  
Rieger Syndrome ◽  
Complete Penetrance ◽  
Main Challenge ◽  
Eye Disorders ◽  
Homeobox Transcription Factor ◽  
Polarity Determination ◽  
Correct Function

Axenfeld–Rieger syndrome (ARS) is a rare autosomal dominant inherited disorder affecting the development of the eyes, teeth and abdomen. The syndrome is characterised by complete penetrance but variable expressivity. The ocular component of the ARS phenotype has acquired most clinical attention and has been dissected into a spectrum of developmental eye disorders, of which open-angle glaucoma represents the main challenge in terms of treatment. Mutations in several chromosomal loci have been implicated in ARS, including PITX2, FOXC1 and PAX6. Full-spectrum ARS is caused primarily by mutations in the PITX2 gene. The homeobox transcription factor PITX2 is produced as at least four different transcriptional and splicing isoforms, with different biological properties. Intriguingly, PITX2 is also involved in left–right polarity determination, although asymmetry defects are not a feature of ARS. In experimental animal models and in cell culture experiments using PITX2, abundant evidence indicates that a narrow window of expression level of this gene is vital for its correct function.

scholarly journals Staggered Herringbone Microfluid Device for the Manufacturing of Chitosan/TPP Nanoparticles: Systematic Optimization and Preliminary Biological Evaluation

2019 ◽  
Vol 20 (24) ◽  
pp. 6212 ◽  
Author(s):  
Enrica Chiesa ◽  
Antonietta Greco ◽  
Federica Riva ◽  
Elena Maria Tosca ◽  
Rossella Dorati ◽  
...  
Keyword(s):  
Sodium Tripolyphosphate ◽  
Biomedical Application ◽  
Diffusion Mechanism ◽  
Chitosan Nanoparticles ◽  
Human Mesenchymal Stem Cells ◽  
Biological Properties ◽  
Biological Evaluation ◽  
Main Process ◽  
Preliminary Evaluation ◽  
Main Challenge

Chitosan nanoparticles (CS NPs) showed promising results in drug, vaccine and gene delivery for the treatment of various diseases. The considerable attention towards CS was owning to its outstanding biological properties, however, the main challenge in the application of CS NPs was faced during their size-controlled synthesis. Herein, ionic gelation reaction between CS and sodium tripolyphosphate (TPP), a widely used and safe CS cross-linker for biomedical application, was exploited by a microfluidic approach based on a staggered herringbone micromixer (SHM) for the synthesis of TPP cross-linked CS NPs (CS/TPP NPs). Screening design of experiments was applied to systematically evaluate the main process and formulative factors affecting CS/TPP NPs physical properties (mean size and size distribution). Effectiveness of the SHM-assisted manufacturing process was confirmed by the preliminary evaluation of the biological performance of the optimized CS/TPP NPs that were internalized in the cytosol of human mesenchymal stem cells through clathrin-mediated mechanism. Curcumin, selected as a challenging model drug, was successfully loaded into CS/TPP NPs (EE% > 70%) and slowly released up to 48 h via the diffusion mechanism. Finally, the comparison with the conventional bulk mixing method corroborated the efficacy of the microfluidics-assisted method due to the precise control of mixing at microscales.

Pediatric Ophthalmology for Primary Care, 3rd Ed

2007 ◽  
Author(s):  
Kenneth W. Wright
Keyword(s):  
Treatment Approach ◽  
Pediatric Ophthalmology ◽  
Genetic Syndromes ◽  
Full Spectrum ◽  
Resource Manual ◽  
Clinic Foundation ◽  
New Information ◽  
Eye Disorders ◽  
Effective Diagnosis ◽  
Clinical Resource

Formatted for practical problem solving, the new 3rd edition of this clinical resource manual covers the full spectrum of eye disorders, eye examinations, vision screening, strabismus, dyslexia, ocular trauma, genetic syndromes, and all the diverse pediatric-specific eye disorders you are likely to encounter. "This book is a useful and well presented source of pediatric ophthalmology. The excellent photos are clear and crisp." Stephen Mikell, MD, Ochsner Clinic Foundation, Doody's Review, 2008. Clear, concise explanations and recommendations are complemented by numerous figures and photographs demonstrating eye pathology. Includes more than 200 color images; ready access to expert guidance through all the steps in effective diagnosis and intervention, including laboratory workup, etiology, differential diagnosis, preferred treatment approach, clinical course, prognosis, and indications for referral; expanded chapter on amblyopia and strabismus; new information on the importance of maintaining physiologic hypoxia; and down syndrome.

scholarly journals Antimicrobial Activity of Calcium Silicate-Based Dental Materials: A Literature Review

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 865
Author(s):  
Ana Cristina Padilha Janini ◽  
Gabriela Fernanda Bombarda ◽  
Lauter Eston Pelepenko ◽  
Marina Angélica Marcano
Keyword(s):  
Antimicrobial Activity ◽  
Calcium Silicate ◽  
Dental Treatment ◽  
Dental Materials ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Biological Tissues ◽  
Biological Properties ◽  
Treatment Techniques ◽  
Main Challenge

Endodontic biomaterials have significantly improved dental treatment techniques in several aspects now that they can be used for vital pulp treatments, as temporary intracanal medication, in definitive fillings, in apical surgeries, and for regenerative procedures. Calcium silicate-based cement is a class of dental material that is used in endodontics in direct contact with the dental structures, connective tissue, and bone. Because the material interacts with biological tissues and stimulates biomineralization processes, its properties are of major importance. The main challenge in endodontic treatments is the elimination of biofilms that are present in the root canal system anatomical complexities, as it remains even after chemical-mechanical preparation and disinfection procedures. Thus, an additional challenge for these biomaterials is to exert antimicrobial activity while maintaining their biological properties in parallel. This article reviews the literature for studies considering the antimicrobial properties of calcium silicate-based dental biomaterials used in endodontic practice. Considering the reviewed studies, it can be affirmed that the reduced antimicrobial effect exhibited by calcium silicate-based endodontic materials clearly emphasizes that all clinical procedures prior to their use must be carefully performed. Future studies for the evaluation of these materials, and especially newly proposed materials, under poly-microbial biofilms associated with endodontic diseases will be necessary.

scholarly journals A SIX6 Nonsense Variant in Golden Retrievers with Congenital Eye Malformations

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 454 ◽  
Author(s):  
Petra Hug ◽  
Linda Anderegg ◽  
Nicole Dürig ◽  
Vincent Lepori ◽  
Vidhya Jagannathan ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Dominant Mode ◽  
Incomplete Penetrance ◽  
Loss Of Function ◽  
Reading Frame ◽  
Eye Disorders ◽  
Residual Amount ◽  
Homeobox Transcription Factor ◽  
The Common ◽  
Close Relatives

Causative genetic variants for more than 30 heritable eye disorders in dogs have been reported. For other clinically described eye disorders, the genetic cause is still unclear. We investigated four Golden Retriever litters segregating for highly variable congenital eye malformations. Several affected puppies had unilateral or bilateral retina dysplasia and/or optic nerve hypoplasia. The four litters shared the same father or grandfather suggesting a heritable condition with an autosomal dominant mode of inheritance. The genome of one affected dog was sequenced and compared to 601 control genomes. A heterozygous private nonsense variant, c.487C>T, was found in the SIX6 gene. This variant is predicted to truncate about a third of the open reading frame, p.(Gln163*). We genotyped all available family members and 464 unrelated Golden Retrievers. All three available cases were heterozygous. Five additional close relatives including the common sire were also heterozygous, but did not show any obvious eye phenotypes. The variant was absent from the 464 unrelated Golden Retrievers and 17 non-affected siblings of the cases. The SIX6 protein is a homeobox transcription factor with a known role in eye development. In humans and other species, SIX6 loss of function variants were reported to cause congenital eye malformations. This strongly suggests that the c.487C>T variant detected contributed to the observed eye malformations. We hypothesize that the residual amount of functional SIX6 protein likely to be expressed in heterozygous dogs is sufficient to explain the observed incomplete penetrance and the varying severity of the eye defects in the affected dogs.

scholarly journals Pitx2 Regulates Procollagen Lysyl Hydroxylase (Plod) Gene Expression

2001 ◽  
Vol 152 (3) ◽  
pp. 545-552 ◽  
Author(s):  
Tord A. Hjalt ◽  
Brad A. Amendt ◽  
Jeffrey C. Murray
Keyword(s):  
Homeobox Gene ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Ehlers Danlos Syndrome ◽  
Lysyl Hydroxylase ◽  
Rieger Syndrome ◽  
Organ Systems ◽  
Polarity Determination ◽  
Dominant Disease

The Rieger syndrome is an autosomal dominant disease characterized by ocular, craniofacial, and umbilical defects. Patients have mutations in PITX2, a paired-bicoid homeobox gene, also involved in left/right polarity determination. In this study we have identified a family of genes for enzymes responsible for hydroxylizing lysines in collagens as one group of likely cognate targets of PITX2 transcriptional regulation. The mouse procollagen lysyl hydroxylase (Plod)-2 gene was enriched for by chromatin precipitation using a PITX2/Pitx2-specific antibody. Plod-2, as well as the human PLOD-1 promoters, contains multiple bicoid (PITX2) binding elements. We show these elements to bind PITX2 specifically in vitro. The PLOD-1 promoter induces the expression of a luciferase reporter gene in the presence of PITX2 in cotransfection experiments. The Rieger syndrome causing PITX2 mutant T68P fails to induce PLOD-1–luciferase. Mutations and rearrangements in PLOD-1 are known to be prevalent in patients with Ehlers-Danlos syndrome, kyphoscoliosis type (type VI [EDVI]). Several of the same organ systems are involved in Rieger syndrome and EDVI.

Cloning and characterization of a novel bicoid-related homeobox transcription factor gene, RIEG, involved in Rieger syndrome

1996 ◽  
Vol 14 (4) ◽  
pp. 392-399 ◽  
Author(s):  
Elena V. Semina ◽  
Rebecca Reiter ◽  
Nancy J. Leysens ◽  
W. Lee M. Alward ◽  
Kent W. Small ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factor Gene ◽  
Factor Gene ◽  
Rieger Syndrome ◽  
Homeobox Transcription Factor

Observed and Theoretical Spectra in the 10–100Å Interval

1988 ◽  
Vol 102 ◽  
pp. 259-261
Author(s):  
W.A. Brown ◽  
M.E. Bruner ◽  
L.W. Acton
Keyword(s):  
Sounding Rocket ◽  
Full Spectrum ◽  
X Ray

AbstractThe soft x-ray spectra recorded in two sounding rocket flights in 1982 and 1985 are compared with with predicted spectra. The poster presents the processed densitometer trace of the full spectrum together with the new spectrum from the 1985 experiment. This note compares the intensities of the lines with predictions.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

Polarity Determination in Sphalerite and Wurtzite Structures

1990 ◽  
Vol 48 (2) ◽  
pp. 500-501
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Opposite Polarity ◽  
Single Domain ◽  
Polar Material ◽  
Electron Microscopic ◽  
Dynamical Interaction ◽  
X Ray ◽  
Polarity Determination ◽  
The Absolute ◽  
Microscopic Techniques

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.

Membrane–cytoskeleton interactions in cholesterol-dependent domain formation

2015 ◽  
Vol 57 ◽  
pp. 177-187 ◽  
Author(s):  
Jennifer N. Byrum ◽  
William Rodgers
Keyword(s):  
Biological Properties ◽  
Membrane Rafts ◽  
Membrane Domains ◽  
Biological Functions ◽  
Membrane Cytoskeleton ◽  
Heterogeneous Structures ◽  
Integral Role ◽  
Model Cell ◽  
Actomyosin Cytoskeleton ◽  
Dependent Domain

Since the inception of the fluid mosaic model, cell membranes have come to be recognized as heterogeneous structures composed of discrete protein and lipid domains of various dimensions and biological functions. The structural and biological properties of membrane domains are represented by CDM (cholesterol-dependent membrane) domains, frequently referred to as membrane ‘rafts’. Biological functions attributed to CDMs include signal transduction. In T-cells, CDMs function in the regulation of the Src family kinase Lck (p56lck) by sequestering Lck from its activator CD45. Despite evidence of discrete CDM domains with specific functions, the mechanism by which they form and are maintained within a fluid and dynamic lipid bilayer is not completely understood. In the present chapter, we discuss recent advances showing that the actomyosin cytoskeleton has an integral role in the formation of CDM domains. Using Lck as a model, we also discuss recent findings regarding cytoskeleton-dependent CDM domain functions in protein regulation.

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