Smard

Single-molecule analysis of replicated DNA (SMARD) is a unique technique that enables visualization of DNA replication at specific genomic regions at single-molecule resolution. Here, we present a protocol for visualizing DNA replication by SMARD. We describe steps for pulse labeling DNA, followed by isolating and stretching of genomic DNA. We then detail the detection of the replication at chromosomal regions through immunostaining and fluorescence in situ hybridization. Using SMARD, we can visualize replication initiation, progression, termination, and fork stalling...

The biphasic life cycle (latent and lytic) of Kaposi's sarcoma-associated Herpesvirus (KSHV) is regulated by epigenetic modification of its genome and its associated histone proteins. The temporal events driving epigenetic reprogramming of the KSHV genome on initial infection to establish latency has been well studied, but the reversal of these epigenetic changes during lytic replication, especially under physiological conditions such as hypoxia, has not been explored. In this study, we investigated epigenetic reprogramming of the KSHV genome during hypoxic reactivation...

This paper develops a novel optimization methodology for designing Shape-memory-alloy resisting devices (SMARDs) and optimally allocating them to inelastic multistory structures. The solution algorithm is a control gains optimization procedure that refers to a formal optimization problem with an objective function subject to the state-space equation and design limitations. The objective function integrates the squared state components in time, and the state-space equation consists of a newly introduced state vector form that reflects the system's inelasticity...

LAS1L encodes a nucleolar ribosomal biogenesis protein and is also a component of the Five Friends of Methylated CHTOP (5FMC) complex. Mutations in the LAS1L gene can be associated with Wilson-Turner syndrome (WTS) and, much more rarely, severe infantile hypotonia with respiratory failure. Here, we present an eighteen-month old boy with a phenotype of spinal muscular atrophy with respiratory distress (SMARD). By applying WES, we identified a novel hemizygous synonymous variant in the LAS1L gene inherited from an unaffected mother (c...

Spinal muscular atrophy with respiratory distress type 1 (SMARD 1) is a rare autosomal recessive disease characterized by distal muscular atrophy and respiratory distress. It presents between six weeks and six months of age, with an eventual requirement of respiratory support. To date, no curative treatment to attenuate or stop the clinical deterioration has been found; therefore, supportive treatment is the corner stone of management. We report a 12-week-old infant with SMARD1 initially diagnosed and managed as a case of infant botulism secondary to a history of significant exposure to honey...

BACKGROUND: The superior mesenteric artery (SMA) is exposed and dissected during pancreatic resections (PR) and mesenteric vascular surgery (MVS). The resulting damage of the surrounding extrinsic and intrinsic vegetative nerve plexus can lead to a temporary or treatment refractory diarrhea. OBJECTIVE: This study aimed to provide an overview of the current status of SMA revascularization and dissection-associated diarrhea (SMARD syndrome) in Germany. MATERIAL AND METHODS: After a selective literature search (SLS) on the frequency of newly developed postoperative diarrhea after PR and MVS, an online survey was initiated...

Single molecule analysis of replicating DNA (SMARD) is a powerful methodology that allows in vivo analysis of replicating DNA; identification of origins of replication, assessment of fork directionality, and measurement of replication fork speed. SMARD, which has been extensively used to study replication of nuclear DNA, involves incorporation of thymidine analogs to nascent DNA chains and their subsequent visualization through immune detection. Here, we adapt and fine-tune the SMARD technique to the specifics of human and mouse mitochondrial DNA...

DNA combing technology is a powerful methodology for the study of DNA replication in vivo. This tool can be used to identify origins of replication, assess of directionality of forks, and measure fork speed. Over the years, the method has been used extensively to study nuclear DNA replication. The first step involves the incorporation of thymidine analogs (CldU and IdU) into nascent DNA chains and followed by their visualization with immunofluorescence using antibodies that can distinguish the two analogs. Recently, we adapted and fine-tuned DNA combing technology to the specifics of mitochondrial DNA (Phillips et al...

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a rare autosomal recessive disease characterized by infancy-onset diaphragmatic palsy and symmetrical distal muscular weakness. SMARD1 is caused by loss-of-function mutations in IGHMBP2 gene. In this article, we report a male SMARD1 patient with two compound heterozygous mutations (NM_002180.2: c.688C > G; p.(Gln230Glu)) and (NM_002180.2: c.1737C > A; p.(Phe579Leu)), one of which (c.688C > G; ClinVar accession: SUB3344743: SCV000612189) is novel...

The current issue of Neurology® Genetics emphasizes the unparalleled role of next-generation sequencing (NGS) in defining an expanding spectrum of genetic neurologic disorders. Clinically, NGS encompasses the use of large gene panels, whole-exome sequencing (WES), or whole-genome sequencing (WGS). The impact of NGS technology is twofold. First, researchers have discovered novel genes as the cause of neurologic disorders. This research includes the efforts of Martikainen et al.(1) to define further the phenotype of a previously reported SNCA mutation that is associated with autosomal dominant Parkinson disease...

Based on its in vitro unwinding activity on G-quadruplex (G4) DNA, the Bloom syndrome-associated helicase BLM is proposed to participate in telomere replication by aiding fork progression through G-rich telomeric DNA. Single molecule analysis of replicated DNA (SMARD) was used to determine the contribution of BLM helicase to telomere replication. In BLM-deficient cells, replication forks initiating from origins within the telomere, which copy the G-rich strand by leading strand synthesis, moved slower through the telomere compared with the adjacent subtelomere...

Using single molecule analysis of replicated DNA (SMARD), Drosopoulos et al. (2015; J. Cell Biol. https://dx.doi.org/10.1083/jcb.201410061) report that DNA replication initiates at measurable frequency within the telomere of mouse chromosome arm 14q. They demonstrate that resolution of G4 structures on the G-rich template strand of the telomere requires some overlapping functions of BLM and WRN helicase for leading strand synthesis.

Kaposi's sarcoma associated herpesvirus (KSHV), like other human herpes viruses, establishes a biphasic life cycle referred to as dormant or latent, and productive or lytic phases. The latent phase is characterized by the persistence of viral episomes in a highly ordered chromatin structure and with the expression of a limited number of viral genes. Latency Associated Nuclear Antigen (LANA) is among the most abundantly expressed proteins during latency and is required for various nuclear functions including the recruitment of cellular machineries for viral DNA replication and segregation of the replicated genomes to daughter cells...

Pediatric Student/Resident Case Report PostersSESSION TYPE: Medical Student/Resident Case ReportPRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PMINTRODUCTION: Spinal muscular atrophy (SMA) with respiratory distress type 1 (SMARD-1) is a rare and fatal autosomal recessive disorder with only 60 case reports to date1. It is clinically and genetically distinct from classic SMA due to early respiratory distress from diaphragmatic paralysis, symmetrical distal muscle weakness, peripheral sensory neuropathy and autonomic nerve dysfunction...

This study aims to investigate how well the Assessment of SpondyloArthritis international Society (ASAS)/Outcome Measures in Rheumatology Clinical Trials (OMERACT) core set and response criteria for ankylosing spondylitis (AS) have been implemented in randomized controlled trials (RCTs) testing pharmacological and non-pharmacological interventions. A systematic literature search was performed up to June 2013 looking for RCTs in patients with axial spondyloarthritis (SpA) (AS and non-radiographic axial SpA)...

OBJECTIVE: We describe a novel congenital motor neuron disease with early demise due to respiratory insufficiency with clinical overlap with spinal muscular atrophy with respiratory distress (SMARD) type 1 but lacking a mutation in the IGHMBP2 gene. METHODS: Exome sequencing was used to identify a de novo mutation in the LAS1L gene in the proband. Pathogenicity of the mutation was validated using a zebrafish model by morpholino-mediated knockdown of las1l. RESULTS: We identified a de novo mutation in the X-linked LAS1L gene in the proband (p...

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a clinically heterogeneous disorder linked to mutations in the immunoglobulin mu-binding protein 2 (IGHMBP2) gene on chromosome 11q13-q21. Most infants with SMARD1 present between six weeks and six months of age with respiratory distress secondary to diaphragmatic weakness and progressive distal weakness. Sensory and autonomic dysfunctions sometimes accompany the motor weakness. This report describes a male infant with genetically confirmed SMARD1 presenting with onset of disease in the first two weeks of life with respiratory compromise and urinary retention, which has not been reported before and adds to the phenotypic variability of SMARD 1...

Telomeric and adjacent subtelomeric heterochromatin pose significant challenges to the DNA replication machinery. Little is known about how replication progresses through these regions in human cells. Using single molecule analysis of replicated DNA (SMARD), we delineate the replication programs-i.e., origin distribution, termination site location, and fork rate and direction-of specific telomeres/subtelomeres of individual human chromosomes in two embryonic stem (ES) cell lines and two primary somatic cell types...

Spinal muscular atrophy with respiratory distress (SMARD 1) is a very rare autosomal recessive motor neuron disorder that affects infants and is characterized by diaphragmatic palsy, symmetrical distal muscular weakness, muscle atrophy, peripheral sensory neuropathy and autonomic nerve dysfunction. SMARD 1 is inherited as an autosomal recessive trait and the mutations have been identified in the gene encoding immunoglobulin μ-binding protein 2 (IGHMBP2), located on chromosome 11q13. It is considered a fatal form of infantile motoneuron disease and most of the patients dies within the first 13 months of life...

Kaposi's sarcoma associated herpesvirus (KSHV), an etiologic agent of Kaposi's sarcoma, Body Cavity Based Lymphoma and Multicentric Castleman's Disease, establishes lifelong latency in infected cells. The KSHV genome tethers to the host chromosome with the help of a latency associated nuclear antigen (LANA). Additionally, LANA supports replication of the latent origins within the terminal repeats by recruiting cellular factors. Our previous studies identified and characterized another latent origin, which supported the replication of plasmids ex-vivo without LANA expression in trans...