Diffusion Tensor Imaging (DTI) in the Early Detection of Multiple Sclerosis

Diffusion Tensor Imaging (DTI) in the Early Detection of Multiple Sclerosis Brooke Boxrud American Class of 2022 Hand-stitched on linen Multiple Sclerosis (MS) is a chronic disease that occurs when the immune system attacks nerve fibers and myelin sheathing in the brain and spinal cord. MS is the most common inflammatory demyelinating disorder of the central nervous system, and it is characterized by either a relapsing-remitting or progressive course. Early detection of the disease is critical, as its progression is often rapid. Conventional magnetic resonance imaging (MRI) to detect white matter lesions is not specific to the underlying pathology of MS and lacks sensitivity to microstructural damage in the normal-appearing white matter (NAWM). Diffusion Tensor Imaging (DTI), on the other hand, measures the magnitude and direction of water diffusion within the brain tissues, and it is sensitive to diffuse abnormalities that would otherwise appear unaffected in conventional MRI. Additionally, DTI can detect significant differences on the lesions as well as surrounding regions. Future application of DTI to identify changes in MS lesions may allow for the early detection, treatment, and prognosis of MS. Information obtained from the diffusion tensor can be visualized by a vibrant color map of the tracts’ position, direction (red for right-left, blue for dorsal-ventral, green for anterior-posterior), and anisotropy (as indicated by the tract\u27s brightness). The position, direction, and anisotropy of the tracts are represented by the blending of brightly colored threads throughout the piece. The intricate stitching and branching pattern of white thread highlights DTI’s ability to detect microstructural abnormalities in white matter. Although MS is classified as a white matter disease, recent studies have shown MS to also affect regions of gray matter, as indicated by the layering of white stitches over a sheet of gray linen. The edges of the fabric were left raw and torn to resemble the deteriorating nature of the disease. This piece is dedicated to my Aunt Dell who was diagnosed with MS in 2017. She is an incredible artist, and I am always inspired by her creativity

Allele distribution and genetic diversity of VNTR loci in Salmonella enterica serotype Enteritidis isolates from different sources

<p>Abstract</p> <p>Background</p> <p><it>Salmonella enterica </it>serotype Enteritidis (<it>S</it>. Enteritidis) is a zoonotic pathogen, which can be found in many sources including animals and the environment. However, little is known about the molecular relatedness among <it>S</it>. Enteritidis isolates from different sources. We have applied multiple-locus variable number tandem repeat analysis (MLVA) to study the genetic diversity of <it>S</it>. Enteritidis isolates from human and non-human sources.</p> <p>Results</p> <p>We identified 38 unique MLVA types using nine VNTR loci markers for discrimination between 145 <it>S</it>. Enteritidis isolates from different sources including humans (n = 41), chickens (n = 45), and eggs (n = 40). There were 20 distinct MLVA types identified from human isolates, 17 distinct MLVA types from chicken isolates, and 5 from egg isolates. We compared allele distribution and frequency for each VNTR marker and measured allelic polymorphism within each VNTR locus of <it>S</it>. Enteritidis isolates from the sources using Nei's diversity index (<it>D</it>). Differences in allele distribution and frequency were detected in most loci of study isolates. Different genetic diversity for certain loci was identified in isolates from different sources. The average of genetic diversity (<it>D</it>) was lower in egg isolates (0.16) compared to human (0.41) and chicken (0.30). However, for loci SE3, SE7, and SE9, human isolates showed significantly higher diversity than both chicken and egg isolates. Whereas for loci SE5 and SE10, chicken isolates had significantly higher diversity than both human and egg isolates. Minimum-spanning tree (MST) comprised one major cluster, a minor cluster, and four clonal expansions. MLVA application enabled a cluster analysis by the MST of the <it>S</it>. Enteritidis isolates by sources, which allows a great insight into the genetic relatedness and the possible flow of these organisms between different reservoirs and humans.</p> <p>Conclusion</p> <p>Differences in allele distribution and genetic diversity of VNTR loci in <it>S</it>. Enteritidis isolates from different sources were found. Polymorphism in most of the VNTR loci was more frequent among human <it>S</it>. Enteritidis isolates than isolates from chickens or eggs. Therefore, VNTR profiles of <it>S</it>. Enteritidis isolates from a specific source should be further evaluated as potential markers in epidemiologic investigations to trace <it>S</it>. Enteritidis to their probable source.</p

Multiple-locus variable-number tandem repeat analysis of Salmonella Enteritidis isolates from human and non-human sources using a single multiplex PCR

Simplified multiple-locus variable-number tandem repeat analysis (MLVA) was developed using one-shot multiplex PCR for seven variable-number tandem repeats (VNTR) markers with high diversity capacity. MLVA, phage typing, and PFGE methods were applied on 34 diverse Salmonella Enteritidis isolates from human and non-human sources. MLVA detected allelic variations that helped to classify the S. Enteritidis isolates into more evenly distributed subtypes than other methods. MLVA-based S. Enteritidis clonal groups were largely associated with sources of the isolates. Nei's diversity indices for polymorphism ranged from 0.25 to 0.70 for seven VNTR loci markers. Based on Simpson's and Shannon's diversity indices, MLVA had a higher discriminatory power than pulsed field gel electrophoresis (PFGE), phage typing, or multilocus enzyme electrophoresis. Therefore, MLVA may be used along with PFGE to enhance the effectiveness of the molecular epidemiologic investigation of S. Enteritidis infections

Genotypic characterization of a monophasic variant of Salmonella enterica serotype typhimurium in swine in USA Midwest

Non-typhoidal Salmonella enterica are a major human foodborne pathogens worldwide (Kirk et al., 2015). Salmonella enterica is divided into six subspecies and approximately 2,500 serotypes according to the Kauffmann-White scheme (Brenner et al., 2000). Serotype 4,5,12:i:-, a monophasic variant of S. Typhimurium lacking the 2nd phase flagellar antigen. Salmonella 4,5,12:i:- has emerged globally in both humans and animals (Echeita et al., 2001; Switt et al., 2009; Centers for Disease Control and Prevention (CDC), 2013) and pork products and pigs are implicated as important sources of human infections (Mossong et al., 2007; Hauser et al., 2010)

Methicillin-Resistant Staphylococcus aureus at Canoe Camp

We investigated a cluster of community-associated methicillin-resistant Staphylococcus aureus infections among persons at a wilderness canoe camp. Isolates from the investigation had identical profiles for susceptibility, pulsed-field gel electrophoresis, and toxins. Participants in activities that involve skin injury, person-to-person contact, and inadequate hygiene are at increased risk for methicillin-resistant S. aureus infections

Conservation and global distribution of non-canonical antigens in enterotoxigenic Escherichia coli

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) cause significant diarrheal morbidity and mortality in children of resource-limited regions, warranting development of effective vaccine strategies. Genetic diversity of the ETEC pathovar has impeded development of broadly protective vaccines centered on the classical canonical antigens, the colonization factors and heat-labile toxin. Two non-canonical ETEC antigens, the EtpA adhesin, and the EatA mucinase are immunogenic in humans and protective in animal models. To foster rational vaccine design that complements existing strategies, we examined the distribution and molecular conservation of these antigens in a diverse population of ETEC isolates. METHODS: Geographically diverse ETEC isolates (n = 1159) were interrogated by PCR, immunoblotting, and/or whole genome sequencing (n = 46) to examine antigen conservation. The most divergent proteins were purified and their core functions assessed in vitro. RESULTS: EatA and EtpA or their coding sequences were present in 57.0% and 51.5% of the ETEC isolates overall, respectively; and were globally dispersed without significant regional differences in antigen distribution. These antigens also exhibited \u3e93% amino acid sequence identity with even the most divergent proteins retaining the core adhesin and mucinase activity assigned to the prototype molecules. CONCLUSIONS: EtpA and EatA are well-conserved molecules in the ETEC pathovar, suggesting that they serve important roles in virulence and that they could be exploited for rational vaccine design

Salmonella enterica Pulsed-Field Gel Electrophoresis Clusters, Minnesota, USA, 2001–2007

This procedure can help identify outbreaks of salmonellosis

Rifampin-resistant Meningococcal Disease

Rifampin-resistant meningococcal disease occurred in a child who had completed rifampin chemoprophylaxis for exposure to a sibling with meningococcemia. Susceptibility testing of 331 case isolates found only 1 other case of rifampin-resistant disease in Minnesota, USA, during 11 years of statewide surveillance. Point mutations in the RNA polymerase β subunit (rpoB) gene were found in isolates from each rifampin-resistant case-patient

Invasive Group A Streptococcal Disease in Nursing Homes, Minnesota, 1995–2006

Nursing home residents are at high risk for invasive GAS disease; clusters are common