Publications by authors named "Nahm M"

Painful diabetic neuropathy commonly affects the peripheral nervous system in individuals with diabetes. However, the pathological processes and mechanisms underlying diabetic neuropathic pain remain unclear. We aimed to identify the overall profiles and screen for genes potentially involved in pain mechanisms using transcriptome analysis of the dorsal root ganglion of diabetic mice treated with streptozotocin (STZ).

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Article Synopsis
  • The polysaccharide capsule of pneumococcus protects the bacteria from the host immune system and is the main target for existing vaccines; however, the effectiveness of these vaccines can be compromised by variations in the capsule structure.
  • Recent research has identified a new capsule type, 20C, which differs from the previously known B subtype due to gene inactivation affecting the capsule structure.
  • There is a need for advanced genetic screening and bioinformatics to monitor mutations in capsule-related genes, which could influence vaccine effectiveness and the emergence of new capsule variants.
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Background: S. pneumoniae (SP) serotypes 15B and 15C are frequent causative agents of invasive pneumococcal disease (IPD), otitis media, and nasopharyngeal colonization in the post PCV13 era. The principal difference between serotypes 15B and 15C is the presence of an O-acetyl group on the pentasaccharide repeating unit of 15B polysaccharide.

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Pneumococcal vaccines are a cornerstone for the prevention of pneumococcal diseases, reducing morbidity and mortality in children and adults worldwide. Pneumococcal vaccine composition is based on the polysaccharide capsule of , which is one of the most important identified contributors to the pathogen's virulence. Similarities in the structural composition of polysaccharides included in licensed pneumococcal vaccines may result in cross-reactivity of immune response against closely related serotypes, including serotypes not included in the vaccine.

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A multiplexed opsonophagocytosis assay (MOPA) was developed as a cost-effective, high-throughput biological assay to evaluate the efficacy of pneumococcal vaccines by measurement of opsonophagocytic activity of anti-capsular antibodies. Here, we report draft genomes of the 36 strains of developed for use in the reference pneumococcal MOPA.

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  • Immune responses during pneumococcal carriage help protect against Streptococcus pneumoniae colonization and infection, with a study measuring specific IgG levels and opsonic titers in adults with and without type 2 diabetes.
  • The study included 176 samples, with findings showing similar IgG concentrations against various serotypes for both groups but higher opsonic titers in non-diabetic individuals, particularly for serotypes 19F and 9V.
  • The results suggest that while antibody production is comparable for both capsular polysaccharide and protein antigens in diabetic and non-diabetic individuals, the functional protective capacity of these antibodies differs significantly between the two groups.
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Unlabelled: Capsular polysaccharides (CPS) in are pivotal for bacterial virulence and present extensive diversity. While oral streptococci show pronounced antigenicity toward pneumococcal capsule-specific sera, insights into evolution of capsule diversity remain limited. This study reports a pneumococcal CPS-like genetic locus in , a predominant oral .

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Brain aging is a recognized risk factor for neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease), but the intricate interplay between brain aging and the pathogenesis of these conditions remains inadequately understood. Cellular senescence is considered to contribute to cellular dysfunction and inflammaging. According to the threshold theory of senescent cell accumulation, the vulnerability to neurodegenerative diseases is associated with the rates of senescent cell generation and clearance within the brain.

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Background: Progranulin (PGRN) haploinsufficiency due to progranulin gene (GRN) variants can cause frontotemporal dementia (FTD) with aberrant TAR DNA-binding protein 43 (TDP-43) accumulation. Despite microglial burden with TDP-43-related pathophysiology, direct microglial TDP-43 pathology has not been clarified yet, only emphasized in neuronal pathology. Thus, the objective of this study was to investigate TDP-43 pathology in microglia of patients with PGRN haploinsufficiency.

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Pneumococcal infections cause serious illness and death among older adults. The capsular polysaccharide vaccine PPSV23 and conjugated alternative PCV13 can prevent these infections; yet, underlying immunological responses and baseline predictors remain unknown. We vaccinated 39 older adults (>60 years) with PPSV23 or PCV13 and observed comparable antibody responses (day 28) and plasmablast transcriptional responses (day 10); however, the baseline predictors were distinct.

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The sporadic occurrence of unusually enhanced mental clarity before death has been documented over time and cultures, and reported in patients with and without neurodegenerative diseases, psychiatric disorders, and other neurocognitive deficits, as well as those with nonterminal and terminal conditions. Using a purposive sampling method via existing professional networks, clinical presentations of terminal lucidity in pediatric populations, as witnessed by pediatric oncologists and medical personnel, were solicited. We document clinical presentations suggestive of terminal lucidity in children, which were compiled by their attending physician at two large tertiary pediatric hospitals.

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The polysaccharide (PS) capsule is essential for immune evasion and virulence of Streptococcus pneumoniae. Existing pneumococcal vaccines are designed to elicit anticapsule antibodies; however, the effectiveness of these vaccines is being challenged by the emergence of new capsule types or variants. Herein, we characterize a newly discovered capsule type, 33E, that appears to have repeatedly emerged from vaccine type 33F via an inactivation mutation in the capsule glycosyltransferase gene, wciE.

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Microglia plays a key role in determining the progression of amyotrophic lateral sclerosis (ALS), yet their precise role in ALS has not been identified in humans. This study aimed to identify a key factor related to the functional characteristics of microglia in rapidly progressing sporadic ALS patients using the induced microglia model, although it is not identical to brain resident microglia. After confirming that microglia-like cells (iMGs) induced by human monocytes could recapitulate the main signatures of brain microglia, step-by-step comparative studies were conducted to delineate functional differences using iMGs from patients with slowly progressive ALS [ALS(S), n = 14] versus rapidly progressive ALS [ALS(R), n = 15].

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The duplication of the peripheral myelin protein 22 (PMP22) gene causes a demyelinating type of neuropathy, commonly known as Charcot-Marie-Tooth disease type 1A (CMT1A). Development of effective drugs for CMT1A still remains as an unmet medical need. In the present study, we assessed the role of the transforming growth factor beta 4 (TGFβ4)/Nodal axis in the pathogenesis of CMT1A.

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Pneumococcal infections cause serious illness and death among older adults. A capsular polysaccharide vaccine PPSV23 (Pneumovax) and a conjugated polysaccharide vaccine PCV13 (Prevnar) are used to prevent these infections, yet underlying responses, and baseline predictors remain unknown. We recruited and vaccinated 39 older adults (>60 years) with PPSV23 or PCV13.

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While hypogammaglobulinemia is associated with COPD exacerbations, it is unknown whether frequent exacerbators have specific defects in antibody production/function. We hypothesized that reduced quantity/function of serum pneumococcal antibodies correlate with exacerbation risk in the SPIROMICS cohort. We measured total pneumococcal IgG in n = 764 previously vaccinated participants with COPD.

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Article Synopsis
  • Microbial glycan microarrays (MGMs) are tools used to study how host immune factors interact with microbial glycans, but they may not accurately represent the natural glycan structure on microbes.
  • Researchers tested galectin-8 (Gal-8) using both MGMs and intact microbe microarrays (MMAs) with Streptococcus pneumoniae glycans, finding that MMA provided better predictions of Gal-8 interactions.
  • The study concluded that galectin-8 shows antimicrobial activity against specific S. pneumoniae strains, highlighting the benefits of using microarrays that incorporate intact microbes for better understanding host-microbe interactions.
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Streptococcus pneumoniae can produce a wide breadth of antigenically diverse capsule types, a fact that poses a looming threat to the success of vaccines that target pneumococcal polysaccharide (PS) capsule. Yet, many pneumococcal capsule types remain undiscovered and/or uncharacterized. Prior sequence analysis of pneumococcal capsule synthesis () loci suggested the existence of capsule subtypes among isolates identified as "serotype 36" according to conventional capsule typing methods.

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The cellular homeostasis of proteins (proteostasis) and RNA metabolism (ribostasis) are essential for maintaining both the structure and function of the brain. However, aging, cellular stress conditions, and genetic contributions cause disturbances in proteostasis and ribostasis that lead to protein misfolding, insoluble aggregate deposition, and abnormal ribonucleoprotein granule dynamics. In addition to neurons being primarily postmitotic, nondividing cells, they are more susceptible to the persistent accumulation of abnormal aggregates.

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VSA-1 is a semisynthetic saponin adjuvant prepared from naturally occurring saponin and capable of stimulating antigen-specific humoral and cellular immune responses. Its immunostimulating activity in enhancing the immune responses induced by the clinical glycoconjugate pneumococcal vaccine PCV13 is compared with QS-21 in female BALB/c mice. Both VSA-1 and QS-21 boosted IgG and opsonic antibodies titers against seven selected serotypes, including serotypes 3, 14, and 19A that are involved in most PCV13 breakthroughs.

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Increasing genetic evidence supports the hypothesis that variants in the annexin A11 gene () contribute to amyotrophic lateral sclerosis pathogenesis. Therefore, we studied the clinical aspects of sporadic amyotrophic lateral sclerosis patients carrying variants. We also implemented functional experiments to verify the pathogenicity of the hotspot variants associated with amyotrophic lateral sclerosis-frontotemporal dementia.

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Introduction: Since the introduction of pneumococcal conjugate vaccine, there have been warnings of an increase in infections caused by non-vaccine type of Streptococcus pneumoniae strains. Among them, nonencapsulated Streptococcus pneumoniae (NESp) has been reported to cause invasive infections, especially in children and the elderly. Due to low virulence, however, basic experimental reports on invasive infections are limited.

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Reports conflict regarding which lectin-microbial ligand interactions elicit a protective response from the lectin pathway (LP) of complement. Using fluorescent microscopy, we demonstrate the human lectin ficolin-2 binds to serotype 11A capsule polysaccharide dependent on the O-acetyltransferase gene . This triggers complement deposition and promotes opsonophagocytosis of encapsulated pneumococci.

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